Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries (see HYPOXIA, BRAIN). An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive HYDROCEPHALUS). (From Childs Nerv Syst 1992 Sep; 8(6):301-6)
The passage of cells across the layer of ENDOTHELIAL CELLS, i.e., the ENDOTHELIUM; or across the layer of EPITHELIAL CELLS, i.e. the EPITHELIUM.
A MARVEL domain protein that plays an important role in the formation and regulation of the TIGHT JUNCTION paracellular permeability barrier.
Acute and chronic (see also BRAIN INJURIES, CHRONIC) injuries to the brain, including the cerebral hemispheres, CEREBELLUM, and BRAIN STEM. Clinical manifestations depend on the nature of injury. Diffuse trauma to the brain is frequently associated with DIFFUSE AXONAL INJURY or COMA, POST-TRAUMATIC. Localized injuries may be associated with NEUROBEHAVIORAL MANIFESTATIONS; HEMIPARESIS, or other focal neurologic deficits.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.
The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.
An azo dye used in blood volume and cardiac output measurement by the dye dilution method. It is very soluble, strongly bound to plasma albumin, and disappears very slowly.
Cell-cell junctions that seal adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. (Alberts et al., Molecular Biology of the Cell, 2nd ed, p22)
The finer blood vessels of the vasculature that are generally less than 100 microns in internal diameter.
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
A specific blocker of dopamine receptors. It speeds gastrointestinal peristalsis, causes prolactin release, and is used as antiemetic and tool in the study of dopaminergic mechanisms.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Inflammation of the BRAIN due to infection, autoimmune processes, toxins, and other conditions. Viral infections (see ENCEPHALITIS, VIRAL) are a relatively frequent cause of this condition.
A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.
The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Drugs intended to prevent damage to the brain or spinal cord from ischemia, stroke, convulsions, or trauma. Some must be administered before the event, but others may be effective for some time after. They act by a variety of mechanisms, but often directly or indirectly minimize the damage produced by endogenous excitatory amino acids.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.
Forceful administration into the peritoneal cavity of liquid medication, nutrient, or other fluid through a hollow needle piercing the abdominal wall.
The third type of glial cell, along with astrocytes and oligodendrocytes (which together form the macroglia). Microglia vary in appearance depending on developmental stage, functional state, and anatomical location; subtype terms include ramified, perivascular, ameboid, resting, and activated. Microglia clearly are capable of phagocytosis and play an important role in a wide spectrum of neuropathologies. They have also been suggested to act in several other roles including in secretion (e.g., of cytokines and neural growth factors), in immunological processing (e.g., antigen presentation), and in central nervous system development and remodeling.
A villous structure of tangled masses of BLOOD VESSELS contained within the third, lateral, and fourth ventricles of the BRAIN. It regulates part of the production and composition of CEREBROSPINAL FLUID.
Elements of limited time intervals, contributing to particular results or situations.
The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.
A 170-kDa transmembrane glycoprotein from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS. It serves as an ATP-dependent efflux pump for a variety of chemicals, including many ANTINEOPLASTIC AGENTS. Overexpression of this glycoprotein is associated with multidrug resistance (see DRUG RESISTANCE, MULTIPLE).
A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
Peptides generated from AMYLOID BETA-PEPTIDES PRECURSOR. An amyloid fibrillar form of these peptides is the major component of amyloid plaques found in individuals with Alzheimer's disease and in aged individuals with trisomy 21 (DOWN SYNDROME). The peptide is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Isomeric forms and derivatives of octanol (C8H17OH).
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)
The relationship between the dose of an administered drug and the response of the organism to the drug.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
A watery fluid that is continuously produced in the CHOROID PLEXUS and circulates around the surface of the BRAIN; SPINAL CORD; and in the CEREBRAL VENTRICLES.
NECROSIS occurring in the MIDDLE CEREBRAL ARTERY distribution system which brings blood to the entire lateral aspects of each CEREBRAL HEMISPHERE. Clinical signs include impaired cognition; APHASIA; AGRAPHIA; weak and numbness in the face and arms, contralaterally or bilaterally depending on the infarction.
The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
The circulation of blood through the BLOOD VESSELS of the BRAIN.
An endopeptidase that is structurally similar to MATRIX METALLOPROTEINASE 2. It degrades GELATIN types I and V; COLLAGEN TYPE IV; and COLLAGEN TYPE V.
A specialized transport barrier, in the EYE, formed by the retinal pigment EPITHELIUM, and the ENDOTHELIUM of the BLOOD VESSELS of the RETINA. TIGHT JUNCTIONS joining adjacent cells keep the barrier between cells continuous.
A circumscribed collection of purulent exudate in the brain, due to bacterial and other infections. The majority are caused by spread of infected material from a focus of suppuration elsewhere in the body, notably the PARANASAL SINUSES, middle ear (see EAR, MIDDLE); HEART (see also ENDOCARDITIS, BACTERIAL), and LUNG. Penetrating CRANIOCEREBRAL TRAUMA and NEUROSURGICAL PROCEDURES may also be associated with this condition. Clinical manifestations include HEADACHE; SEIZURES; focal neurologic deficits; and alterations of consciousness. (Adams et al., Principles of Neurology, 6th ed, pp712-6)
The barrier between capillary blood and alveolar air comprising the alveolar EPITHELIUM and capillary ENDOTHELIUM with their adherent BASEMENT MEMBRANE and EPITHELIAL CELL cytoplasm. PULMONARY GAS EXCHANGE occurs across this membrane.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Substances used to allow enhanced visualization of tissues.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
A specialized barrier, in the TESTIS, between the interstitial BLOOD compartment and the adluminal compartment of the SEMINIFEROUS TUBULES. The barrier is formed by layers of cells from the VASCULAR ENDOTHELIUM of the capillary BLOOD VESSELS, to the SEMINIFEROUS EPITHELIUM of the seminiferous tubules. TIGHT JUNCTIONS form between adjacent SERTOLI CELLS, as well as between the ENDOTHELIAL CELLS.
Those factors, such as language or sociocultural relationships, which interfere in the meaningful interpretation and transmission of ideas between individuals or groups.

Involvement of tumor necrosis factor alpha and interleukin-1beta in enhancement of pentylenetetrazole-induced seizures caused by Shigella dysenteriae. (1/3796)

Neurologic manifestations, mainly convulsions, are the most frequent extraintestinal complications of shigellosis. We used an animal model to study the roles of tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in Shigella-related seizures. Administration of Shigella dysenteriae 60R sonicate enhanced the sensitivity of mice to the proconvulsant pentylenetetrazole (PTZ) within 7 h. This was indicated by a significantly higher mean convulsion score and an increased number of mice responding with clonic-tonic seizures in the Shigella-pretreated group. Preinjection of mice with anti-murine TNF-alpha (anti-mTNF-alpha) or anti-murine IL-1beta (anti-mIL-1beta) 30 min prior to administration of Shigella sonicate abolished their enhanced response to PTZ at 7 h. Mean convulsion scores were reduced by anti-mTNF-alpha from 1.2 to 0.8 (P = 0.017) and by anti-mIL-1beta from 1.3 to 0.7 (P = 0.008). Preinjection of anti-mTNF-alpha also reduced the percentage of mice responding with clonic-tonic seizures, from 48 to 29% (P = 0.002), and preinjection of anti-mIL-1beta reduced it from 53 to 21% (P = 0. 012). Neutralization of TNF-alpha or IL-1beta did not protect the mice from death due to S. dysenteriae 60R. These findings indicate that TNF-alpha and IL-1beta play a role in the very early sensitization of the central nervous system to convulsive activity after S. dysenteriae administration. Similar mechanisms may trigger neurologic disturbances in other infectious diseases.  (+info)

Drug-protein binding and blood-brain barrier permeability. (2/3796)

The permeability surface area (PS) product, an index of permeability of the blood-brain barrier (BBB), was measured by using the in situ perfusion method. In the cerebral circulation, the fraction of drug that permeates into the brain through the BBB is not only the unbound fraction but also the fraction dissociated from the protein in the perfusate. The sum of these two fractions, the apparent exchangeable fraction, was estimated by fitting the parameters of the BBB permeability under the condition of varying BSA concentrations in the perfusate. The unbound fraction of drugs in a buffer containing 0.5 mM BSA was measured by using the ultrafiltration method in vitro, and the apparent exchangeable fraction was measured in vivo by using the intracarotid artery injection method. The apparent exchange fraction was 100% for S-8510, 96.5% for diazepam, 90.9% for caffeine, 38.3% for S-312-d, 33.1% for propranolol, and 6.68% for (+)-S-145 Na, and each of these was higher than the corresponding unbound fraction in vitro in all drugs. The apparent exchangeable fractions, for example, were 8 times higher for diazepam and 38 times for S-312-d than the unbound fractions in vitro. The apparent exchangeable fraction of drugs was also estimated from the parameters obtained with the perfusion method. Because drugs can be infused for an arbitrary length of time in the perfusion method, substances with low permeability can be measured. The apparent exchangeable fractions obtained with this method were almost the same as those obtained with the intracarotid artery injection method.  (+info)

Novel, highly lipophilic antioxidants readily diffuse across the blood-brain barrier and access intracellular sites. (3/3796)

In an accompanying article, an in vitro assay for permeability predicts that membrane-protective, antioxidant 2,4-diamino-pyrrolo[2, 3-d]pyrimidines should have improved blood-brain barrier (BBB) permeation over previously described lipophilic antioxidants. Using a first-pass extraction method and brain/plasma quantification, we show here that two of the pyrrolopyrimidines, one of which is markedly less permeable, readily partition into rat brain. The efficiency of extraction was dependent on serum protein binding, and in situ efflux confirms the in vitro data showing that PNU-87663 is retained in brain longer than PNU-89843. By exploiting inherent fluorescence properties of PNU-87663, its distribution within brain and within cells in culture was demonstrated using confocal scanning laser microscopy. PNU-87663 rapidly partitioned into the cell membrane and equilibrates with cytoplasmic compartments via passive diffusion. Although partitioning of PNU-87663 favors intracytoplasmic lipid storage droplets, the compound was readily exchangeable as shown by efflux of compound from cells to buffer when protein was present. The results demonstrated that pyrrolopyrimidines were well suited for quickly accessing target cells within the central nervous system as well as in other target tissues.  (+info)

Inhibition by lead of production and secretion of transthyretin in the choroid plexus: its relation to thyroxine transport at blood-CSF barrier. (4/3796)

Long-term, low-dose Pb exposure in rats is associated with a significant decrease in transthyretin (TTR) concentrations in the CSF. Since CSF TTR, a primary carrier of thyroxine in brain, is produced and secreted by the choroid plexus, in vitro studies were conducted to test whether Pb exposure interferes with TTR production and/or secretion by the choroid plexus, leading to an impaired thyroxine transport at the blood-CSF barrier. Newly synthesized TTR molecules in the cultured choroidal epithelial cells were pulse-labeled with [35S]methionine. [35S]TTR in the cell lysates and culture media was immunoprecipitated and separated by SDS-PAGE, and quantitated by autoradiography and liquid scintillation counting. Pb treatment did not significantly alter the protein concentrations in the culture, but inhibited the synthesis of total [35S]TTR (cells + media), particularly during the later chase phase. Two-way ANOVA of the chase phase revealed that Pb exposure (30 microM) significantly suppressed the rate of secretion of [35S]TTR compared to the controls (p < 0.05). Accordingly, Pb treatment caused a retention of [35S]TTR by the cells. In a two-chamber transport system with a monolayer of epithelial barrier, Pb exposure (30 microM) reduced the initial release rate constant (kr) of [125I]T4 from the cell monolayer to the culture media and impeded the transepithelial transport of [125I]T4 from the basal to apical side of epithelial cells by 27%. Taken together, these in vitro data suggest that sequestration of Pb in the choroid plexus hinders the production and secretion of TTR by this tissue. Consequently, this may alter the transport of thyroxine across this blood-CSF barrier.  (+info)

Receptor-mediated transcytosis of lactoferrin through the blood-brain barrier. (5/3796)

Lactoferrin (Lf) is an iron-binding protein involved in host defense against infection and severe inflammation; it accumulates in the brain during neurodegenerative disorders. Before determining Lf function in brain tissue, we investigated its origin and demonstrate here that it crosses the blood-brain barrier. An in vitro model of the blood-brain barrier was used to examine the mechanism of Lf transport to the brain. We report that differentiated bovine brain capillary endothelial cells exhibited specific high (Kd = 37.5 nM; n = 90,000/cell) and low (Kd = 2 microM; n = 900,000 sites/cell) affinity binding sites. Only the latter were present on nondifferentiated cells. The surface-bound Lf was internalized only by the differentiated cell population leading to the conclusion that Lf receptors were acquired during cell differentiation. A specific unidirectional transport then occurred via a receptor-mediated process with no apparent intraendothelial degradation. We further report that iron may cross the bovine brain capillary endothelial cells as a complex with Lf. Finally, we show that the low density lipoprotein receptor-related protein might be involved in this process because its specific antagonist, the receptor-associated protein, inhibits 70% of Lf transport.  (+info)

Nonsaturable entry of neuropeptide Y into brain. (6/3796)

Neuropeptide Y (NPY) is found and is active both in the periphery and brain, but its crossing of the blood-brain barrier (BBB) in either direction has not been measured. We used multiple time-regression analysis to determine that radioactively labeled NPY injected intravenously entered the brain much faster than albumin, with an influx constant of 2.0 x 10(-4) ml. g. -1. min-1. However, this rate of entry was not significantly changed by injection of 10 microgram/mouse of excess NPY, by leptin, or by food deprivation. HPLC showed that most of the NPY entering the brain was intact, and capillary depletion with and without washout showed that the NPY did not remain bound to endothelial cells or associated with vascular elements. Perfusion in a blood-free solution eliminated binding to serum proteins as an explanation for the lack of saturation. Efflux of labeled NPY from the brain occurred at the same rate as albumin, reflecting the normal rate of reabsorption of cerebrospinal fluid. Thus NPY can readily enter the brain from blood by diffusion across the BBB.  (+info)

Selective delivery of herpes virus vectors to experimental brain tumors using RMP-7. (7/3796)

RMP-7, a bradykinin analog, has been shown to selectively open the blood-tumor barrier for the delivery of chemotherapeutic drugs to brain tumors. In contrast to bradykinin, RMP-7 has no hypotensive effects and has been approved for human use. This study was initiated to determine whether RMP-7 would open the blood-tumor barrier to virus vectors encoding tumor-killing genes in an experimental model. The herpes virus vector used, hrR3, which encodes virus thymidine kinase gene and the lacZ reporter gene, is defective in a gene encoding ribonucleotide reductase, replicates selectively in dividing tumor cells and not in postmitotic neural cells. It was determined that an optimum dose of RMP-7 (1.5-3.0 microg/kg over 10-15 minutes) enhanced viral delivery to brain tumors in rats bearing intracranial 9 L gliosarcomas when infused through the carotid artery immediately prior to virus vector application. Maximum expression of the lacZ reporter gene occurred at 3 days after intracarotid infusion. By 8 days, transgene expression was largely confined to tumor foci away from the main tumor mass. Viral delivery was essentially specific to tumor cells, with little transgene expression elsewhere in the brain. Minimal uptake and pathology was noted in the kidney, spleen, and liver. These findings indicate that intracarotid delivery of RMP-7 can augment the selective delivery of virus vectors to brain tumors in an experimental rat model, with the potential for application to human brain tumors.  (+info)

Orexin A but not orexin B rapidly enters brain from blood by simple diffusion. (8/3796)

We determined the ability of orexin A and orexin B, recently discovered endogenous appetite enhancers, to cross the blood-brain barrier (BBB) of mice. Multiple time-regression analysis showed that an i.v. bolus of 125I-orexin A rapidly entered the brain from the blood, with an influx rate (Ki = 2.5 +/- 0.3 x 10(-4) ml/g.min) many times faster than that of the 99mTc-albumin control. This relatively rapid rate of entry was not reduced by administration of excess orexin A (or leptin) or by fasting for 22 h, even when penetration into only the hypothalamus was measured. Lack of saturability also was shown by perfusion in blood-free buffer. HPLC revealed that most of the injected 125I-orexin A reached the brain as intact peptide. Capillary depletion studies showed that the administered peptide did not remain bound to the endothelial cells comprising the BBB but reached the brain parenchyma. Efflux of 125I-orexin A from the brain occurred at the same rate as 99mTc-albumin. The octanol/buffer partition coefficient of 0.232 showed that orexin A was highly lipophilic, whereas the value for orexin B was only 0.030. Orexin B, moreover, was rapidly degraded in blood, so no 125I-orexin B could be detected in intact form in brain when injected peripherally. Thus, although orexin B is rapidly metabolized in blood and has low lipophilicity, orexin A rapidly crosses the BBB from blood to reach brain tissue by the process of simple diffusion.  (+info)

The Blood-Brain Barrier (BBB) is a highly specialized, selective interface between the central nervous system (CNS) and the circulating blood. It is formed by unique endothelial cells that line the brain's capillaries, along with tight junctions, astrocytic foot processes, and pericytes, which together restrict the passage of substances from the bloodstream into the CNS. This barrier serves to protect the brain from harmful agents and maintain a stable environment for proper neural function. However, it also poses a challenge in delivering therapeutics to the CNS, as most large and hydrophilic molecules cannot cross the BBB.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Brain edema is a medical condition characterized by the abnormal accumulation of fluid in the brain, leading to an increase in intracranial pressure. This can result from various causes, such as traumatic brain injury, stroke, infection, brain tumors, or inflammation. The swelling of the brain can compress vital structures, impair blood flow, and cause neurological symptoms, which may range from mild headaches to severe cognitive impairment, seizures, coma, or even death if not treated promptly and effectively.

Transendothelial migration (TEM) and transepithelial migration (TRM) are terms used to describe the movement of cells, typically leukocytes (white blood cells), across endothelial or epithelial cell layers. These processes play a crucial role in immune surveillance and inflammation.

Transendothelial migration refers specifically to the movement of cells across the endothelium, which is the layer of cells that lines the interior surface of blood vessels. This process allows leukocytes to leave the bloodstream and enter surrounding tissues during an immune response. TEM can be further divided into two main steps:

1. Adhesion: The initial attachment of leukocytes to the endothelium, mediated by adhesion molecules expressed on both the leukocyte and endothelial cell surfaces.
2. Diapedesis: The transmigration step where leukocytes squeeze between adjacent endothelial cells and move through the basement membrane to reach the underlying tissue.

Transepithelial migration, on the other hand, refers to the movement of cells across an epithelium, which is a layer of cells that forms a barrier between a body cavity or lumen (such as the gut or airways) and the underlying tissue. TRM can be observed in various physiological processes like wound healing and immune cell trafficking, but it also plays a role in pathological conditions such as cancer metastasis. Similar to TEM, TRM can be divided into several steps:

1. Adhesion: The initial attachment of cells to the epithelium, facilitated by adhesion molecules and receptors.
2. Polarization: Cells become polarized, forming protrusions that help them navigate through the tight junctions between epithelial cells.
3. Diapedesis: The transmigration step where cells move across the epithelium, often involving the disassembly and reassembly of tight junctions between epithelial cells.
4. Re-epithelialization: After cell migration is complete, the epithelial layer needs to be restored by re-establishing tight junctions and maintaining barrier integrity.

Occludin is a protein that is a component of tight junctions, which are structures that form a barrier between adjacent cells in epithelial and endothelial tissues. Tight junctions help to regulate the movement of molecules between cells and play a crucial role in maintaining the integrity of these tissues.

Occludin is composed of four transmembrane domains, two extracellular loops, and intracellular N- and C-termini. The extracellular loops interact with other tight junction proteins to form the intercellular seal, while the intracellular domains interact with various signaling molecules and cytoskeletal components to regulate the assembly and disassembly of tight junctions.

Mutations in the gene that encodes occludin have been associated with various human diseases, including inflammatory bowel disease, liver cirrhosis, and skin disorders. Additionally, changes in occludin expression and localization have been implicated in the development of cancer and neurological disorders.

A brain injury is defined as damage to the brain that occurs following an external force or trauma, such as a blow to the head, a fall, or a motor vehicle accident. Brain injuries can also result from internal conditions, such as lack of oxygen or a stroke. There are two main types of brain injuries: traumatic and acquired.

Traumatic brain injury (TBI) is caused by an external force that results in the brain moving within the skull or the skull being fractured. Mild TBIs may result in temporary symptoms such as headaches, confusion, and memory loss, while severe TBIs can cause long-term complications, including physical, cognitive, and emotional impairments.

Acquired brain injury (ABI) is any injury to the brain that occurs after birth and is not hereditary, congenital, or degenerative. ABIs are often caused by medical conditions such as strokes, tumors, anoxia (lack of oxygen), or infections.

Both TBIs and ABIs can range from mild to severe and may result in a variety of physical, cognitive, and emotional symptoms that can impact a person's ability to perform daily activities and function independently. Treatment for brain injuries typically involves a multidisciplinary approach, including medical management, rehabilitation, and supportive care.

In the context of medicine and physiology, permeability refers to the ability of a tissue or membrane to allow the passage of fluids, solutes, or gases. It is often used to describe the property of the capillary walls, which control the exchange of substances between the blood and the surrounding tissues.

The permeability of a membrane can be influenced by various factors, including its molecular structure, charge, and the size of the molecules attempting to pass through it. A more permeable membrane allows for easier passage of substances, while a less permeable membrane restricts the movement of substances.

In some cases, changes in permeability can have significant consequences for health. For example, increased permeability of the blood-brain barrier (a specialized type of capillary that regulates the passage of substances into the brain) has been implicated in a number of neurological conditions, including multiple sclerosis, Alzheimer's disease, and traumatic brain injury.

Endothelial cells are the type of cells that line the inner surface of blood vessels, lymphatic vessels, and heart chambers. They play a crucial role in maintaining vascular homeostasis by controlling vasomotor tone, coagulation, platelet activation, and inflammation. Endothelial cells also regulate the transport of molecules between the blood and surrounding tissues, and contribute to the maintenance of the structural integrity of the vasculature. They are flat, elongated cells with a unique morphology that allows them to form a continuous, nonthrombogenic lining inside the vessels. Endothelial cells can be isolated from various tissues and cultured in vitro for research purposes.

Capillary permeability refers to the ability of substances to pass through the walls of capillaries, which are the smallest blood vessels in the body. These tiny vessels connect the arterioles and venules, allowing for the exchange of nutrients, waste products, and gases between the blood and the surrounding tissues.

The capillary wall is composed of a single layer of endothelial cells that are held together by tight junctions. The permeability of these walls varies depending on the size and charge of the molecules attempting to pass through. Small, uncharged molecules such as water, oxygen, and carbon dioxide can easily diffuse through the capillary wall, while larger or charged molecules such as proteins and large ions have more difficulty passing through.

Increased capillary permeability can occur in response to inflammation, infection, or injury, allowing larger molecules and immune cells to enter the surrounding tissues. This can lead to swelling (edema) and tissue damage if not controlled. Decreased capillary permeability, on the other hand, can lead to impaired nutrient exchange and tissue hypoxia.

Overall, the permeability of capillaries is a critical factor in maintaining the health and function of tissues throughout the body.

Evans Blue is not a medical condition or diagnosis, but rather a dye that is used in medical research and tests. It is a dark blue dye that binds to albumin (a type of protein) in the bloodstream. This complex is too large to pass through the walls of capillaries, so it remains in the blood vessels and does not enter the surrounding tissues. As a result, Evans Blue can be used as a marker to visualize or measure the volume of the circulatory system.

In research settings, Evans Blue is sometimes used in studies involving the brain and nervous system. For example, it may be injected into the cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) to help researchers see the distribution of this fluid in the brain. It can also be used to study blood-brain barrier function, as changes in the permeability of the blood-brain barrier can allow Evans Blue to leak into the brain tissue.

It is important to note that Evans Blue should only be used under the supervision of a trained medical professional, as it can be harmful if ingested or inhaled.

Tight junctions, also known as zonula occludens, are specialized types of intercellular junctions that occur in epithelial and endothelial cells. They are located near the apical side of the lateral membranes of adjacent cells, where they form a continuous belt-like structure that seals off the space between the cells.

Tight junctions are composed of several proteins, including occludin, claudins, and junctional adhesion molecules (JAMs), which interact to form a network of strands that create a tight barrier. This barrier regulates the paracellular permeability of ions, solutes, and water, preventing their uncontrolled movement across the epithelial or endothelial layer.

Tight junctions also play an important role in maintaining cell polarity by preventing the mixing of apical and basolateral membrane components. Additionally, they are involved in various signaling pathways that regulate cell proliferation, differentiation, and survival.

Microvessels are the smallest blood vessels in the body, including capillaries, venules, and arterioles. They form a crucial part of the circulatory system, responsible for delivering oxygen and nutrients to tissues and organs while removing waste products. Capillaries, the tiniest microvessels, facilitate the exchange of substances between blood and tissue cells through their thin walls. Overall, microvessels play a vital role in maintaining proper organ function and overall health.

Brain neoplasms, also known as brain tumors, are abnormal growths of cells within the brain. These growths can be benign (non-cancerous) or malignant (cancerous). Benign brain tumors typically grow slowly and do not spread to other parts of the body. However, they can still cause serious problems if they press on sensitive areas of the brain. Malignant brain tumors, on the other hand, are cancerous and can grow quickly, invading surrounding brain tissue and spreading to other parts of the brain or spinal cord.

Brain neoplasms can arise from various types of cells within the brain, including glial cells (which provide support and insulation for nerve cells), neurons (nerve cells that transmit signals in the brain), and meninges (the membranes that cover the brain and spinal cord). They can also result from the spread of cancer cells from other parts of the body, known as metastatic brain tumors.

Symptoms of brain neoplasms may vary depending on their size, location, and growth rate. Common symptoms include headaches, seizures, weakness or paralysis in the limbs, difficulty with balance and coordination, changes in speech or vision, confusion, memory loss, and changes in behavior or personality.

Treatment for brain neoplasms depends on several factors, including the type, size, location, and grade of the tumor, as well as the patient's age and overall health. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence and manage any long-term effects of treatment.

Domperidone is a medication that belongs to the class of dopamine antagonists. It works by blocking the action of dopamine, a chemical in the brain that can cause nausea and vomiting. Domperidone is primarily used to treat symptoms of gastroesophageal reflux disease (GERD) and gastric motility disorders, including bloating, fullness, and regurgitation. It works by increasing the contractions of the stomach muscles, which helps to move food and digestive juices through the stomach more quickly.

Domperidone is available in various forms, such as tablets, suspension, and injection. The medication is generally well-tolerated, but it can cause side effects such as dry mouth, diarrhea, headache, and dizziness. In rare cases, domperidone may cause more serious side effects, including irregular heart rhythms, tremors, or muscle stiffness.

It is important to note that domperidone has a risk of causing cardiac arrhythmias, particularly at higher doses and in patients with pre-existing heart conditions. Therefore, it should be used with caution and only under the supervision of a healthcare professional.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Encephalitis is defined as inflammation of the brain parenchyma, which is often caused by viral infections but can also be due to bacterial, fungal, or parasitic infections, autoimmune disorders, or exposure to toxins. The infection or inflammation can cause various symptoms such as headache, fever, confusion, seizures, and altered consciousness, ranging from mild symptoms to severe cases that can lead to brain damage, long-term disabilities, or even death.

The diagnosis of encephalitis typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and laboratory tests (such as cerebrospinal fluid analysis). Treatment may include antiviral medications, corticosteroids, immunoglobulins, and supportive care to manage symptoms and prevent complications.

Astrocytes are a type of star-shaped glial cell found in the central nervous system (CNS), including the brain and spinal cord. They play crucial roles in supporting and maintaining the health and function of neurons, which are the primary cells responsible for transmitting information in the CNS.

Some of the essential functions of astrocytes include:

1. Supporting neuronal structure and function: Astrocytes provide structural support to neurons by ensheathing them and maintaining the integrity of the blood-brain barrier, which helps regulate the entry and exit of substances into the CNS.
2. Regulating neurotransmitter levels: Astrocytes help control the levels of neurotransmitters in the synaptic cleft (the space between two neurons) by taking up excess neurotransmitters and breaking them down, thus preventing excessive or prolonged activation of neuronal receptors.
3. Providing nutrients to neurons: Astrocytes help supply energy metabolites, such as lactate, to neurons, which are essential for their survival and function.
4. Modulating synaptic activity: Through the release of various signaling molecules, astrocytes can modulate synaptic strength and plasticity, contributing to learning and memory processes.
5. Participating in immune responses: Astrocytes can respond to CNS injuries or infections by releasing pro-inflammatory cytokines and chemokines, which help recruit immune cells to the site of injury or infection.
6. Promoting neuronal survival and repair: In response to injury or disease, astrocytes can become reactive and undergo morphological changes that aid in forming a glial scar, which helps contain damage and promote tissue repair. Additionally, they release growth factors and other molecules that support the survival and regeneration of injured neurons.

Dysfunction or damage to astrocytes has been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS).

The Central Nervous System (CNS) is the part of the nervous system that consists of the brain and spinal cord. It is called the "central" system because it receives information from, and sends information to, the rest of the body through peripheral nerves, which make up the Peripheral Nervous System (PNS).

The CNS is responsible for processing sensory information, controlling motor functions, and regulating various autonomic processes like heart rate, respiration, and digestion. The brain, as the command center of the CNS, interprets sensory stimuli, formulates thoughts, and initiates actions. The spinal cord serves as a conduit for nerve impulses traveling to and from the brain and the rest of the body.

The CNS is protected by several structures, including the skull (which houses the brain) and the vertebral column (which surrounds and protects the spinal cord). Despite these protective measures, the CNS remains vulnerable to injury and disease, which can have severe consequences due to its crucial role in controlling essential bodily functions.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Brain ischemia is the medical term used to describe a reduction or interruption of blood flow to the brain, leading to a lack of oxygen and glucose delivery to brain tissue. This can result in brain damage or death of brain cells, known as infarction. Brain ischemia can be caused by various conditions such as thrombosis (blood clot formation), embolism (obstruction of a blood vessel by a foreign material), or hypoperfusion (reduced blood flow). The severity and duration of the ischemia determine the extent of brain damage. Symptoms can range from mild, such as transient ischemic attacks (TIAs or "mini-strokes"), to severe, including paralysis, speech difficulties, loss of consciousness, and even death. Immediate medical attention is required for proper diagnosis and treatment to prevent further damage and potential long-term complications.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Neuroprotective agents are substances that protect neurons or nerve cells from damage, degeneration, or death caused by various factors such as trauma, inflammation, oxidative stress, or excitotoxicity. These agents work through different mechanisms, including reducing the production of free radicals, inhibiting the release of glutamate (a neurotransmitter that can cause cell damage in high concentrations), promoting the growth and survival of neurons, and preventing apoptosis (programmed cell death). Neuroprotective agents have been studied for their potential to treat various neurological disorders, including stroke, traumatic brain injury, Parkinson's disease, Alzheimer's disease, and multiple sclerosis. However, more research is needed to fully understand their mechanisms of action and to develop effective therapies.

Nanoparticles are defined in the field of medicine as tiny particles that have at least one dimension between 1 to 100 nanometers (nm). They are increasingly being used in various medical applications such as drug delivery, diagnostics, and therapeutics. Due to their small size, nanoparticles can penetrate cells, tissues, and organs more efficiently than larger particles, making them ideal for targeted drug delivery and imaging.

Nanoparticles can be made from a variety of materials including metals, polymers, lipids, and dendrimers. The physical and chemical properties of nanoparticles, such as size, shape, charge, and surface chemistry, can greatly affect their behavior in biological systems and their potential medical applications.

It is important to note that the use of nanoparticles in medicine is still a relatively new field, and there are ongoing studies to better understand their safety and efficacy.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Drug delivery systems (DDS) refer to techniques or technologies that are designed to improve the administration of a pharmaceutical compound in terms of its efficiency, safety, and efficacy. A DDS can modify the drug release profile, target the drug to specific cells or tissues, protect the drug from degradation, and reduce side effects.

The goal of a DDS is to optimize the bioavailability of a drug, which is the amount of the drug that reaches the systemic circulation and is available at the site of action. This can be achieved through various approaches, such as encapsulating the drug in a nanoparticle or attaching it to a biomolecule that targets specific cells or tissues.

Some examples of DDS include:

1. Controlled release systems: These systems are designed to release the drug at a controlled rate over an extended period, reducing the frequency of dosing and improving patient compliance.
2. Targeted delivery systems: These systems use biomolecules such as antibodies or ligands to target the drug to specific cells or tissues, increasing its efficacy and reducing side effects.
3. Nanoparticle-based delivery systems: These systems use nanoparticles made of polymers, lipids, or inorganic materials to encapsulate the drug and protect it from degradation, improve its solubility, and target it to specific cells or tissues.
4. Biodegradable implants: These are small devices that can be implanted under the skin or into body cavities to deliver drugs over an extended period. They can be made of biodegradable materials that gradually break down and release the drug.
5. Inhalation delivery systems: These systems use inhalers or nebulizers to deliver drugs directly to the lungs, bypassing the digestive system and improving bioavailability.

Overall, DDS play a critical role in modern pharmaceutical research and development, enabling the creation of new drugs with improved efficacy, safety, and patient compliance.

"Intraperitoneal injection" is a medical term that refers to the administration of a substance or medication directly into the peritoneal cavity, which is the space between the lining of the abdominal wall and the organs contained within it. This type of injection is typically used in clinical settings for various purposes, such as delivering chemotherapy drugs, anesthetics, or other medications directly to the abdominal organs.

The procedure involves inserting a needle through the abdominal wall and into the peritoneal cavity, taking care to avoid any vital structures such as blood vessels or nerves. Once the needle is properly positioned, the medication can be injected slowly and carefully to ensure even distribution throughout the cavity.

It's important to note that intraperitoneal injections are typically reserved for situations where other routes of administration are not feasible or effective, as they carry a higher risk of complications such as infection, bleeding, or injury to surrounding organs. As with any medical procedure, it should only be performed by trained healthcare professionals under appropriate clinical circumstances.

Microglia are a type of specialized immune cell found in the brain and spinal cord. They are part of the glial family, which provide support and protection to the neurons in the central nervous system (CNS). Microglia account for about 10-15% of all cells found in the CNS.

The primary role of microglia is to constantly survey their environment and eliminate any potentially harmful agents, such as pathogens, dead cells, or protein aggregates. They do this through a process called phagocytosis, where they engulf and digest foreign particles or cellular debris. In addition to their phagocytic function, microglia also release various cytokines, chemokines, and growth factors that help regulate the immune response in the CNS, promote neuronal survival, and contribute to synaptic plasticity.

Microglia can exist in different activation states depending on the nature of the stimuli they encounter. In a resting state, microglia have a small cell body with numerous branches that are constantly monitoring their surroundings. When activated by an injury, infection, or neurodegenerative process, microglia change their morphology and phenotype, retracting their processes and adopting an amoeboid shape to migrate towards the site of damage or inflammation. Based on the type of activation, microglia can release both pro-inflammatory and anti-inflammatory factors that contribute to either neuroprotection or neurotoxicity.

Dysregulation of microglial function has been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Amyotrophic Lateral Sclerosis (ALS). Therefore, understanding the role of microglia in health and disease is crucial for developing novel therapeutic strategies to treat these conditions.

The choroid plexus is a network of blood vessels and tissue located within each ventricle (fluid-filled space) of the brain. It plays a crucial role in the production of cerebrospinal fluid (CSF), which provides protection and nourishment to the brain and spinal cord.

The choroid plexus consists of modified ependymal cells, called plexus epithelial cells, that line the ventricular walls. These cells have finger-like projections called villi, which increase their surface area for efficient CSF production. The blood vessels within the choroid plexus transport nutrients, ions, and water to these epithelial cells, where they are actively secreted into the ventricles to form CSF.

In addition to its role in CSF production, the choroid plexus also acts as a barrier between the blood and the central nervous system (CNS), regulating the exchange of substances between them. This barrier function is primarily attributed to tight junctions present between the epithelial cells, which limit the paracellular movement of molecules.

Abnormalities in the choroid plexus can lead to various neurological conditions, such as hydrocephalus (excessive accumulation of CSF) or certain types of brain tumors.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Neuroglia, also known as glial cells or simply glia, are non-neuronal cells that provide support and protection for neurons in the nervous system. They maintain homeostasis, form myelin sheaths around nerve fibers, and provide structural support. They also play a role in the immune response of the central nervous system. Some types of neuroglia include astrocytes, oligodendrocytes, microglia, and ependymal cells.

P-glycoprotein (P-gp) is a type of membrane transport protein that plays a crucial role in the efflux (extrusion) of various substrates, including drugs and toxins, out of cells. It is also known as multidrug resistance protein 1 (MDR1).

P-gp is encoded by the ABCB1 gene and is primarily located on the apical membrane of epithelial cells in several tissues, such as the intestine, liver, kidney, and blood-brain barrier. Its main function is to protect these organs from harmful substances by actively pumping them out of the cells and back into the lumen or bloodstream.

In the context of pharmacology, P-gp can contribute to multidrug resistance (MDR) in cancer cells. When overexpressed, P-gp can reduce the intracellular concentration of various anticancer drugs, making them less effective. This has led to extensive research on inhibitors of P-gp as potential adjuvants for cancer therapy.

In summary, P-glycoprotein is a vital efflux transporter that helps maintain homeostasis by removing potentially harmful substances from cells and can impact drug disposition and response in various tissues, including the intestine, liver, kidney, and blood-brain barrier.

Inflammation is a complex biological response of tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. It is characterized by the following signs: rubor (redness), tumor (swelling), calor (heat), dolor (pain), and functio laesa (loss of function). The process involves the activation of the immune system, recruitment of white blood cells, and release of inflammatory mediators, which contribute to the elimination of the injurious stimuli and initiation of the healing process. However, uncontrolled or chronic inflammation can also lead to tissue damage and diseases.

Brain chemistry refers to the chemical processes that occur within the brain, particularly those involving neurotransmitters, neuromodulators, and neuropeptides. These chemicals are responsible for transmitting signals between neurons (nerve cells) in the brain, allowing for various cognitive, emotional, and physical functions.

Neurotransmitters are chemical messengers that transmit signals across the synapse (the tiny gap between two neurons). Examples of neurotransmitters include dopamine, serotonin, norepinephrine, GABA (gamma-aminobutyric acid), and glutamate. Each neurotransmitter has a specific role in brain function, such as regulating mood, motivation, attention, memory, and movement.

Neuromodulators are chemicals that modify the effects of neurotransmitters on neurons. They can enhance or inhibit the transmission of signals between neurons, thereby modulating brain activity. Examples of neuromodulators include acetylcholine, histamine, and substance P.

Neuropeptides are small protein-like molecules that act as neurotransmitters or neuromodulators. They play a role in various physiological functions, such as pain perception, stress response, and reward processing. Examples of neuropeptides include endorphins, enkephalins, and oxytocin.

Abnormalities in brain chemistry can lead to various neurological and psychiatric conditions, such as depression, anxiety disorders, schizophrenia, Parkinson's disease, and Alzheimer's disease. Understanding brain chemistry is crucial for developing effective treatments for these conditions.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

A stroke, also known as cerebrovascular accident (CVA), is a serious medical condition that occurs when the blood supply to part of the brain is interrupted or reduced, leading to deprivation of oxygen and nutrients to brain cells. This can result in the death of brain tissue and cause permanent damage or temporary impairment to cognitive functions, speech, memory, movement, and other body functions controlled by the affected area of the brain.

Strokes can be caused by either a blockage in an artery that supplies blood to the brain (ischemic stroke) or the rupture of a blood vessel in the brain (hemorrhagic stroke). A transient ischemic attack (TIA), also known as a "mini-stroke," is a temporary disruption of blood flow to the brain that lasts only a few minutes and does not cause permanent damage.

Symptoms of a stroke may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; severe headache with no known cause; and confusion or disorientation. Immediate medical attention is crucial for stroke patients to receive appropriate treatment and prevent long-term complications.

Leukocytes, also known as white blood cells (WBCs), are a crucial component of the human immune system. They are responsible for protecting the body against infections and foreign substances. Leukocytes are produced in the bone marrow and circulate throughout the body in the bloodstream and lymphatic system.

There are several types of leukocytes, including:

1. Neutrophils - These are the most abundant type of leukocyte and are primarily responsible for fighting bacterial infections. They contain enzymes that can destroy bacteria.
2. Lymphocytes - These are responsible for producing antibodies and destroying virus-infected cells, as well as cancer cells. There are two main types of lymphocytes: B-lymphocytes and T-lymphocytes.
3. Monocytes - These are the largest type of leukocyte and help to break down and remove dead or damaged tissues, as well as microorganisms.
4. Eosinophils - These play a role in fighting parasitic infections and are also involved in allergic reactions and inflammation.
5. Basophils - These release histamine and other chemicals that cause inflammation in response to allergens or irritants.

An abnormal increase or decrease in the number of leukocytes can indicate an underlying medical condition, such as an infection, inflammation, or a blood disorder.

Amyloid beta-peptides (Aβ) are small protein fragments that are crucially involved in the pathogenesis of Alzheimer's disease. They are derived from a larger transmembrane protein called the amyloid precursor protein (APP) through a series of proteolytic cleavage events.

The two primary forms of Aβ peptides are Aβ40 and Aβ42, which differ in length by two amino acids. While both forms can be harmful, Aβ42 is more prone to aggregation and is considered to be the more pathogenic form. These peptides have the tendency to misfold and accumulate into oligomers, fibrils, and eventually insoluble plaques that deposit in various areas of the brain, most notably the cerebral cortex and hippocampus.

The accumulation of Aβ peptides is believed to initiate a cascade of events leading to neuroinflammation, oxidative stress, synaptic dysfunction, and neuronal death, which are all hallmarks of Alzheimer's disease. Although the exact role of Aβ in the onset and progression of Alzheimer's is still under investigation, it is widely accepted that they play a central part in the development of this debilitating neurodegenerative disorder.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Octanols are a type of chemical compound known as alcohols, specifically they are fatty alcohols with a chain of 8 carbon atoms. The most common octanol is called 1-octanol, which has the chemical formula CH3(CH2)7OH. It is a colorless oily liquid that is used in the synthesis of other chemicals and as a solvent. Octanols are often used as standards for measuring the partition coefficient between octanol and water, which is a measure of a compound's hydrophobicity or lipophilicity. This property is important in understanding how a compound may be absorbed, distributed, metabolized, and excreted in the body.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

Alzheimer's disease is a progressive disorder that causes brain cells to waste away (degenerate) and die. It's the most common cause of dementia — a continuous decline in thinking, behavioral and social skills that disrupts a person's ability to function independently.

The early signs of the disease include forgetting recent events or conversations. As the disease progresses, a person with Alzheimer's disease will develop severe memory impairment and lose the ability to carry out everyday tasks.

Currently, there's no cure for Alzheimer's disease. However, treatments can temporarily slow the worsening of dementia symptoms and improve quality of life.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Brain mapping is a broad term that refers to the techniques used to understand the structure and function of the brain. It involves creating maps of the various cognitive, emotional, and behavioral processes in the brain by correlating these processes with physical locations or activities within the nervous system. Brain mapping can be accomplished through a variety of methods, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scans, electroencephalography (EEG), and others. These techniques allow researchers to observe which areas of the brain are active during different tasks or thoughts, helping to shed light on how the brain processes information and contributes to our experiences and behaviors. Brain mapping is an important area of research in neuroscience, with potential applications in the diagnosis and treatment of neurological and psychiatric disorders.

Cerebrospinal fluid (CSF) is a clear, colorless fluid that surrounds and protects the brain and spinal cord. It acts as a shock absorber for the central nervous system and provides nutrients to the brain while removing waste products. CSF is produced by specialized cells called ependymal cells in the choroid plexus of the ventricles (fluid-filled spaces) inside the brain. From there, it circulates through the ventricular system and around the outside of the brain and spinal cord before being absorbed back into the bloodstream. CSF analysis is an important diagnostic tool for various neurological conditions, including infections, inflammation, and cancer.

Middle Cerebral Artery (MCA) infarction is a type of ischemic stroke that occurs when there is an obstruction in the blood supply to the middle cerebral artery, which is one of the major blood vessels that supplies oxygenated blood to the brain. The MCA supplies blood to a large portion of the brain, including the motor and sensory cortex, parts of the temporal and parietal lobes, and the basal ganglia.

An infarction is the death of tissue due to the lack of blood supply, which can lead to damage or loss of function in the affected areas of the brain. Symptoms of MCA infarction may include weakness or numbness on one side of the body, difficulty speaking or understanding speech, vision problems, and altered levels of consciousness.

MCA infarctions can be caused by various factors, including embolism (a blood clot that travels to the brain from another part of the body), thrombosis (a blood clot that forms in the MCA itself), or stenosis (narrowing of the artery due to atherosclerosis or other conditions). Treatment for MCA infarction may include medications to dissolve blood clots, surgery to remove the obstruction, or rehabilitation to help regain lost function.

The brainstem is the lower part of the brain that connects to the spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls many vital functions such as heart rate, breathing, and blood pressure. It also serves as a relay center for sensory and motor information between the cerebral cortex and the rest of the body. Additionally, several cranial nerves originate from the brainstem, including those that control eye movements, facial movements, and hearing.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

Cerebrovascular circulation refers to the network of blood vessels that supply oxygenated blood and nutrients to the brain tissue, and remove waste products. It includes the internal carotid arteries, vertebral arteries, circle of Willis, and the intracranial arteries that branch off from them.

The internal carotid arteries and vertebral arteries merge to form the circle of Willis, a polygonal network of vessels located at the base of the brain. The anterior cerebral artery, middle cerebral artery, posterior cerebral artery, and communicating arteries are the major vessels that branch off from the circle of Willis and supply blood to different regions of the brain.

Interruptions or abnormalities in the cerebrovascular circulation can lead to various neurological conditions such as stroke, transient ischemic attack (TIA), and vascular dementia.

Medical Definition:

Matrix metalloproteinase 9 (MMP-9), also known as gelatinase B or 92 kDa type IV collagenase, is a member of the matrix metalloproteinase family. These enzymes are involved in degrading and remodeling the extracellular matrix (ECM) components, playing crucial roles in various physiological and pathological processes such as wound healing, tissue repair, and tumor metastasis.

MMP-9 is secreted as an inactive zymogen and activated upon removal of its propeptide domain. It can degrade several ECM proteins, including type IV collagen, elastin, fibronectin, and gelatin. MMP-9 has been implicated in numerous diseases, such as cancer, rheumatoid arthritis, neurological disorders, and cardiovascular diseases. Its expression is regulated at the transcriptional, translational, and post-translational levels, and its activity can be controlled by endogenous inhibitors called tissue inhibitors of metalloproteinases (TIMPs).

The blood-retinal barrier (BRB) is a specialized physiological barrier in the eye that helps regulate the movement of molecules between the retina and the bloodstream. It is made up of tight junctions between the endothelial cells of retinal blood vessels and between the pigment epithelium cells of the retina, which restrict the paracellular diffusion of solutes.

The BRB plays a crucial role in maintaining the health and function of the retina by preventing harmful substances from entering the retina while allowing essential nutrients and oxygen to reach the retinal tissues. Disruption of the BRB has been implicated in various retinal diseases, including diabetic retinopathy, age-related macular degeneration, and retinal vein occlusion.

A brain abscess is a localized collection of pus in the brain that is caused by an infection. It can develop as a result of a bacterial, fungal, or parasitic infection that spreads to the brain from another part of the body or from an infection that starts in the brain itself (such as from a head injury or surgery).

The symptoms of a brain abscess may include headache, fever, confusion, seizures, weakness or numbness on one side of the body, and changes in vision, speech, or behavior. Treatment typically involves antibiotics to treat the infection, as well as surgical drainage of the abscess to relieve pressure on the brain.

It is a serious medical condition that requires prompt diagnosis and treatment to prevent potentially life-threatening complications such as brain herniation or permanent neurological damage.

I am not aware of a widely recognized or established medical term called "Blood-Air Barrier." It is possible that you may be referring to a concept or phenomenon that goes by a different name, or it could be a term that is specific to certain context or field within medicine.

In general, the terms "blood" and "air" refer to two distinct and separate compartments in the body, and there are various physiological barriers that prevent them from mixing with each other under normal circumstances. For example, the alveolar-capillary membrane in the lungs serves as a barrier that allows for the exchange of oxygen and carbon dioxide between the air in the alveoli and the blood in the capillaries, while preventing the two from mixing together.

If you could provide more context or clarify what you mean by "Blood-Air Barrier," I may be able to provide a more specific answer.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Contrast media are substances that are administered to a patient in order to improve the visibility of internal body structures or processes in medical imaging techniques such as X-rays, CT scans, MRI scans, and ultrasounds. These media can be introduced into the body through various routes, including oral, rectal, or intravenous administration.

Contrast media work by altering the appearance of bodily structures in imaging studies. For example, when a patient undergoes an X-ray examination, contrast media can be used to highlight specific organs, tissues, or blood vessels, making them more visible on the resulting images. In CT and MRI scans, contrast media can help to enhance the differences between normal and abnormal tissues, allowing for more accurate diagnosis and treatment planning.

There are several types of contrast media available, each with its own specific properties and uses. Some common examples include barium sulfate, which is used as a contrast medium in X-ray studies of the gastrointestinal tract, and iodinated contrast media, which are commonly used in CT scans to highlight blood vessels and other structures.

While contrast media are generally considered safe, they can sometimes cause adverse reactions, ranging from mild symptoms such as nausea or hives to more serious complications such as anaphylaxis or kidney damage. As a result, it is important for healthcare providers to carefully evaluate each patient's medical history and individual risk factors before administering contrast media.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

The endothelium is a thin layer of simple squamous epithelial cells that lines the interior surface of blood vessels, lymphatic vessels, and heart chambers. The vascular endothelium, specifically, refers to the endothelial cells that line the blood vessels. These cells play a crucial role in maintaining vascular homeostasis by regulating vasomotor tone, coagulation, platelet activation, inflammation, and permeability of the vessel wall. They also contribute to the growth and repair of the vascular system and are involved in various pathological processes such as atherosclerosis, hypertension, and diabetes.

The Blood-Testis Barrier (BTB) is a unique structural and functional feature of the seminiferous epithelium in the testes, which forms a tight junction between adjacent Sertoli cells in the semi-niferous tubules. This barrier selectively restricts the passage of molecules, including potentially harmful substances and immune cells, from the systemic circulation into the adluminal compartment of the seminiferous epithelium where spermatogenesis occurs. This helps to maintain a immunologically privileged microenvironment that is essential for the survival and maturation of developing sperm cells, preventing an immune response against them. The BTB also regulates the movement of molecules required for spermatogenesis, such as nutrients, hormones, and signaling molecules, from the basal compartment to the adluminal compartment.

Communication barriers in a medical context refer to any factors that prevent or hinder the effective exchange of information between healthcare providers and patients, or among healthcare professionals themselves. These barriers can lead to misunderstandings, errors, and poor patient outcomes. Common communication barriers include:

1. Language differences: When patients and healthcare providers do not speak the same language, it can lead to miscommunication and errors in diagnosis and treatment.
2. Cultural differences: Cultural beliefs and values can affect how patients perceive and communicate their symptoms and concerns, as well as how healthcare providers deliver care.
3. Literacy levels: Low health literacy can make it difficult for patients to understand medical information, follow treatment plans, and make informed decisions about their care.
4. Disability: Patients with hearing or vision impairments, speech disorders, or cognitive impairments may face unique communication challenges that require accommodations and specialized communication strategies.
5. Emotional factors: Patients who are anxious, stressed, or in pain may have difficulty communicating effectively, and healthcare providers may be less likely to listen actively or ask open-ended questions.
6. Power dynamics: Hierarchical relationships between healthcare providers and patients can create power imbalances that discourage patients from speaking up or asking questions.
7. Noise and distractions: Environmental factors such as noise, interruptions, and distractions can make it difficult for patients and healthcare providers to hear, focus, and communicate effectively.

Effective communication is critical in healthcare settings, and addressing communication barriers requires a multifaceted approach that includes training for healthcare providers, language services for limited English proficient patients, and accommodations for patients with disabilities.

Blood-ocular barrier - Physical barrier between the local blood vessels and most parts of the eye itself Blood-retinal barrier ... The blood-brain barrier is formed by the brain capillary endothelium and excludes from the brain 100% of large-molecule ... The border zones between brain tissue "behind" the blood-brain barrier and zones "open" to blood signals in certain CVOs ... thus protecting the brain from harmful or unwanted substances in the blood. The blood-brain barrier is formed by endothelial ...
To treat brain tumours and other brain related diseases, blood-brain barrier disruption is needed for the anti-cancer drugs to ... The blood-brain barrier (BBB) is protected by a network of blood vessels and tissue that shields it from harmful substances. ... Blood-brain barrier disruption is the surgical process whereby drugs are used to create openings between cells in the blood- ... Studies have shown that blood-brain barrier disruption can cause diseases in the central nervous system. "Definition of blood- ...
Hladky, S. B., & Barrand, M. A. (2016). Fluid and ion transfer across the blood-brain and blood-cerebrospinal fluid barriers; a ... Pardridge W. M. (2012). Drug transport across the blood-brain barrier. Journal of cerebral blood flow and metabolism : official ... Brain Res 1989;482:57-66. Cohen DM, Patel CB, Ahobila-Vajjula P, et al. Blood-spinal cord barrier permeability in experimental ... The anatomy of the BSCB is very similar to the anatomy of the blood-brain barrier (BBB); however many key differences exist ...
the blood-brain barrier. Though there are many morphological features conserved among caveolae, the functions of each CAV ... The importance of them for the clearance of LDL from blood was discovered by Richard G. Anderson, Michael S. Brown and Joseph L ... which removes LDL from circulating blood), the transferrin receptor (which brings ferric ions bound by transferrin into the ...
Francesca, B.; Rezzani, R. (2010). "Aquaporin and Blood Brain Barrier". Current Neuropharmacology. 8 (2): 92-96. doi:10.2174/ ... 1988). "The Colton blood group locus. A linkage analysis". Transfusion. 28 (5): 435-8. doi:10.1046/j.1537-2995.1988.28588337331 ... Additionally, it is found in red blood cells, vascular endothelium, the gastrointestinal tract, sweat glands, lungs, and the ... "Entrez Gene: AQP1 aquaporin 1 (Colton blood group)". Knepper MA (July 1994). "The aquaporin family of molecular water channels ...
Smith, Quentin R. (April 2000). "Transport of glutamate and other amino acids at the blood-brain barrier". The Journal of ... Hawkins, Richard A. (September 2009). "The blood-brain barrier and glutamate". The American Journal of Clinical Nutrition. 90 ( ... Glutamate does not easily pass the blood brain barrier, but, instead, is transported by a high-affinity transport system. It ... Malignant brain tumors known as glioma or glioblastoma exploit this phenomenon by using glutamate as an energy source, ...
Failure of the blood-brain barrier may also be a causal mechanism as it would allow substances in the blood to enter the brain ... Oby E, Janigro D (November 2006). "The blood-brain barrier and epilepsy". Epilepsia. 47 (11): 1761-74. doi:10.1111/j.1528- ... This may be partly done by imaging the brain and performing blood tests. Epilepsy can often be confirmed with an EEG, but a ... Mild brain injury increases the risk about two-fold while severe brain injury increases the risk seven-fold. In those who have ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
Fiori A, Cardelli P, Negri L, Savi MR, Strom R, Erspamer V (August 1997). "Deltorphin transport across the blood-brain barrier ... May 1997). "Structure-activity relationships of a series of [D-Ala2]deltorphin I and II analogues; in vitro blood-brain barrier ... and on account of its unusually high blood-brain-barrier penetration rate, produces centrally-mediated analgesic effects in ...
When the blood-brain barrier has been compromised, albumin-bound Evans blue enters the CNS. Evans blue is pharmacologically ... Evans blue is also used to assess the permeability of the blood-brain barrier to macromolecules. Because serum albumin cannot ... Hawkins BT, Egleton RD (2006). "Fluorescence imaging of blood-brain barrier disruption". Journal of Neuroscience Methods. 151 ( ... Because of this, it can be useful in physiology in estimating the proportion of body water contained in blood plasma. It ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
"Biousian glycopeptides penetrate the blood-brain barrier". Tetrahedron: Asymmetry. Carbohydrate Science. Part 1. 16 (1): 65-75 ... October 2000). "Improved bioavailability to the brain of glycosylated Met-enkephalin analogs". Brain Research. 881 (1): 37-46. ...
2009 Oct 23;105(9):860-8. What is the blood-brain barrier (not)? Bechmann I, Galea I, Perry VH. Trends Immunol. 2007 Jan;28(1): ... Vascular recruitment in the brain is thought to lead to new capillaries and increase the cerebral blood flow. The existence of ... That insulin can act in this way has been proposed based on increases in limb blood flow and skeletal muscle blood volume which ... Evidence that heterogeneity of cerebral blood flow does not involve vascular recruitment. Williams JL, Shea M, Jones SC. Am J ...
Minagar A, Alexander JS (December 2003). "Blood-brain barrier disruption in multiple sclerosis". Mult Scler. 9 (6): 540-9. doi: ... "Spots" can occur as a result of changes in brain water content.: 113 Evoked potential is an electrical potential recorded from ... and other diseases affecting the brain. It has also been used to study the metabolism of other organs such as muscles.: 309 ... Brain Sci. 3 (4): 1282-324. doi:10.3390/brainsci3031282. PMC 4061877. PMID 24961530. Hochmeister S, Romauch M, Bauer J, Seifert ...
It is expressed primarily in the blood-brain barrier and liver and is thought to be involved in protecting cells from toxins. ... "Challenges for blood-brain barrier (BBB) screening". Xenobiotica. 37 (10-11): 1135-51. doi:10.1080/00498250701570285. PMID ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ... and tissue-barrier function. It forms anion-selective paracellular channels and is localized mainly in kidney proximal tubules ... Tissue Barriers. 9 (1): 1848212. doi:10.1080/21688370.2020.1848212. PMC 7849786. PMID 33300427. Krug SM, Günzel D, Conrad MP, ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Sticky cells, blood vessels and cancer - the paradox of Claudin-14 - Marianne Baker, Cancer Research UK Science Update blog, 14 ... Tight junctions form continuous seals around cells and serve as a physical barrier to prevent solutes and water from passing ... There are also suggestions that CLDN14 plays a role in tumour angiogenesis (blood vessel formation), as deletion of a single ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... "Paracellular tightness and claudin-5 expression is increased in the BCEC/astrocyte blood-brain barrier model by increasing ... Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular ... Tsukita S, Furuse M (2002). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
... s have an unusually high blood-brain barrier penetration rate. The nonselective opiate antagonist naloxone inhibits ... "Deltorphin transport across the blood-brain barrier". Proceedings of the National Academy of Sciences of the United States of ... deltorphin uptake by brain microvessels, but neither the selective δ-opioid antagonist naltrindole nor a number of opioid ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
Poor penetration through the blood-brain barrier. Because of numerous adverse effect and limitations in use, new drugs with ... Some were found to have effect on lower blood sugar levels and others act as hemostatics. The most interesting thing was that ... A high number of white cells in the blood indicates leukemia, so a new anti-cancer drug had been discovered. These two ... It is known that some compounds can inhibit the formation of new blood vessels (inhibit the process of angiogenesis) or shut ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ... "A claudin-9-based ion permeability barrier is essential for hearing". PLOS Genetics. 5 (8): e1000610. doi:10.1371/journal.pgen. ...
Over the last decade, S100B has emerged as a candidate peripheral biomarker of blood-brain barrier (BBB) permeability and CNS ... Marchi N, Cavaglia M, Fazio V, Bhudia S, Hallene K, Janigro D (April 2004). "Peripheral markers of blood-brain barrier damage ... Czeisler BM, Janigro D (June 2006). "Reading and writing the blood-brain barrier: relevance to therapeutics". Recent Patents on ... "Seizure-promoting effect of blood-brain barrier disruption". Epilepsia. 48 (4): 732-42. doi:10.1111/j.1528-1167.2007.00988.x. ...
Geldenhuys WJ, Mohammad AS, Adkins CE, Lockman PR (2015). "Molecular determinants of blood-brain barrier permeation". ... "Selective expression of the large neutral amino acid transporter at the blood-brain barrier". Proceedings of the National ...
It is thought that HIV uses a "Trojan horse" mechanism to enter the brain. Normally, the blood-brain barrier (BBB) serves as a ... Berger JR, Avison M (September 2004). "The blood brain barrier in HIV infection". Frontiers in Bioscience. 9 (1-3): 2680-5. doi ... further compromising the blood-brain barrier. The toxicity spreads through a gap junction-dependent mechanism. HIV is ... "Human immunodeficiency virus infection of human astrocytes disrupts blood-brain barrier integrity by a gap junction-dependent ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2002). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ... forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
... some nanoparticles are able to bypass the Blood Brain Barrier to deliver therapeutic drugs to the brain. Nanoparticles have ... Zhou, Yiqun; Peng, Zhili; Seven, Elif S.; Leblanc, Roger M. (2018-01-28). "Crossing the blood-brain barrier with nanoparticles ... They could play an important role in blood vessel cleanup. Theoretically, nanotubes with SHP1i molecules attached to them would ... signal macrophages to clean up plaque in blood vessels without destroying any healthy tissue. Researchers have tested this type ...
Kniesel U, Wolburg H (2000). "Tight junctions of the blood-brain barrier". Cell. Mol. Neurobiol. 20 (1): 57-76. doi:10.1023/A: ... Tsukita S, Furuse M (2003). "Claudin-based barrier in simple and stratified cellular sheets". Curr. Opin. Cell Biol. 14 (5): ...
Blood-ocular barrier - Physical barrier between the local blood vessels and most parts of the eye itself Blood-retinal barrier ... The blood-brain barrier is formed by the brain capillary endothelium and excludes from the brain 100% of large-molecule ... The border zones between brain tissue "behind" the blood-brain barrier and zones "open" to blood signals in certain CVOs ... thus protecting the brain from harmful or unwanted substances in the blood. The blood-brain barrier is formed by endothelial ...
Fatty Acid-Binding Protein 5 at the Blood-Brain Barrier Regulates Endogenous Brain Docosahexaenoic Acid Levels and Cognitive ... Disruption of Bmal1 Impairs Blood-Brain Barrier Integrity via Pericyte Dysfunction Ryota Nakazato, Kenji Kawabe, Daisuke Yamada ... Nonionotropic Action of Endothelial NMDA Receptors on Blood-Brain Barrier Permeability via Rho/ROCK-Mediated Phosphorylation of ... Endothelial Adora2a Activation Promotes Blood-Brain Barrier Breakdown and Cognitive Impairment in Mice with Diet-Induced ...
While the blood-brain barrier (BBB) protects the brain from harmful chemicals occurring naturally in the blood, it also ... Categories Blog Entry, Brain & Behavior, Health, Life & Non-humans Key to blood-brain barrier opens way for treating ... Brain glia cells up their DNA to preserve blood-brain barrier. ScienceBlog.com ... Preventing this damage has been impossible, until now, as many drugs dont cross the so-called blood-brain bar… ...
... suggesting that they can be transported from the lungs to the brain. ... Researchers have discovered fine particles of air pollution in the brains of people diagnosed with neurological disorders, ... Traveling to the brain, the particles "may cross from the bloodstream through the [brain-blood barrier] without visibly ... The brain-blood barrier typically blocks the entry of such intruders but was unable to keep the tiny particles out. ...
... and the blood-spinal cord barrier (BSCB) are responsible for controlling the microenvironment within neural tissues in humans. ... These barriers are fundamental to all neurological processes as they provide the extreme nutritional demands of neural tissue, ... In amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases, these barriers become hyperpermeable, allowing a ... The blood-brain barrier (BBB) and the blood-spinal cord barrier (BSCB) are responsible for controlling the microenvironment ...
... by dietary intervention improves the transport of insulin through the BBB and the sensitivity of insulin in the brain. Although ... Obesity is associated with insulin resistance and reduced transport of insulin through the blood-brain barrier (BBB). Reversal ... Estrogen and insulin transport through the blood-brain barrier Physiol Behav. 2016 Sep 1:163:312-321. doi: 10.1016/j.physbeh. ... Obesity is associated with insulin resistance and reduced transport of insulin through the blood-brain barrier (BBB). Reversal ...
... to transiently open the blood-brain barrier (BBB). However, limited understanding is available regarding the effect of ... The blood-brain barrier (BBB) plays an important role in regulating the exchange of nutrients and wastes between brain tissues ... Pardridge, W. M. The blood-brain barrier: bottleneck in brain drug development. NeuroRx 2, 3-14 (2005). ... Detection of intracerebral hemorrhage and transient blood-supply shortage in focused-ultrasound-induced blood-brain barrier ...
... is the wall that protects our brain from foreign invaders but, at the same time, the gate that allows a myriad of metabolites ... The blood-brain barrier (BBB) is the wall that protects our brain from foreign invaders but, at the same time, the gate that ... The BARCELONA BIOMED CONFERENCE on Brain Blood Barrier will be hosted by the Institut dEstudis Catalans (IEC) in the heart of ... This Barcelona BioMed conference on the "Blood-Brain Barrier" will gather scientists working at the interface between chemistry ...
In Aging Brain, Blood-Brain Barrier Starts Leaking in Hippocampus. Quick Links. *Article ... demonstrating a blood brain barrier (BBB) breakdown and leakage of serum proteins in aged (but not young) human brain (Pappolla ... Blood-brain barrier breakdown in the aging human hippocampus. Neuron. 2015 Jan 21;85(2):296-302. PubMed. ... The reason for a leaky blood-brain barrier (BBB) with aging may well rest with how dysregulated the HPG axis becomes after ...
The 3rd Annual Blood-Brain Barrier Summit Returns in August ... The Blood-Brain Barrier Summit will take place online from June ... CarThera raises €9m to tackle the blood-brain barrier French company CarThera has raised €9 million in its Series B funding ... round to help it develop ultrasound-based medical devices to treat brain disorders and overcome the challenges of the b ...
... triggers leaks in the brains plumbing system, allowing toxic substances ... The findings suggest that the smallest blood vessels in the brain, which form the blood-brain barrier, might be a potential ... which line the walls of blood vessels in the brain and maintain blood-brain barrier integrity, are damaged. These injured ... APOE4 seems to speed up the breakdown of the blood-brain barrier by activating an inflammatory pathway in blood vessels, which ...
Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world ...
The gland is part of the brain but sits outside of the blood brain barrier. The logo seems to indicate that the brain is ... The Warp Speed Logo and the Assault on the Blood Brain Barrier beholdthemark Apr 15, 2021 [snip] The Warp Speed logo is full of ... The Warp Speed Logo and the Assault on the Blood Brain Barrier Posted By: NaturalWisdom. Date: Sunday, 4-Jul-2021 23:26:46 www. ... In the Hindi system the antahkarana essentially symoblizes the mind and by extension, the brain. In the manufactured occult ...
Research has even determined that exposure can disrupt the blood-brain barrier, cause it to leak, and kill brain cells. ... Steel Wool - It Also Disrupts Blood-Brain Barrier. by Contributing Author , Jan 7, 2020 , Headline News , 5 comments ...
... infection of the brain, as well as in facilitating viral entry into the central nervous system. Accordingly, ... Abnormalities in the blood-brain barrier (BBB) may be important in mediating some of the tissue damage that accompanies human ... Abnormalities in the blood-brain barrier (BBB) may be important in mediating some of the tissue damage that accompanies human ... Blood-brain barrier abnormalities in the acquired immunodeficiency syndrome: immunohistochemical localization of serum proteins ...
... about BLOOD-BRAIN BARRIER. Search and download thousands of Swedish university dissertations. Full text. Free. ... blood-brain barrier. Showing result 1 - 5 of 189 swedish dissertations containing the words blood-brain barrier. ... Abstract : The blood-brain barrier (BBB) represents a complex interface between the brain parenchyma and systemic blood ... Abstract : The blood-brain barrier (BBB) controls the movement of substances into and out of the brain. The tight junctions ...
... blood-brain barrier disruption and to see if iopamidol could be safely given intravenously in conjunction with blood-brain ... Osmotic blood-brain barrier disruption: CT and radionuclide imaging.. S Roman-Goldstein, D A Clunie, J Stevens, R Hogan, J ... Osmotic blood-brain barrier disruption: CT and radionuclide imaging.. S Roman-Goldstein, D A Clunie, J Stevens, R Hogan, J ... Osmotic blood-brain barrier disruption: CT and radionuclide imaging.. S Roman-Goldstein, D A Clunie, J Stevens, R Hogan, J ...
Infectious Disease in the Central Nervous System and Therapeutic Strategies to Cross the Blood-Brain Barrier. The page you are ...
Breaching this barrier opens up a new frontier in treating brain disorders ... "The blood-brain barrier (BBB) has been a persistent obstacle to delivering valuable therapies to treat disease such as tumours ... "The blood-brain barrier (BBB) has been a persistent obstacle to delivering valuable therapies to treat disease such as tumours ... World First: Blood Brain Barrier Opened Non-Invasively to Deliver Chemotherapy. Toronto, ON (November 8, 2015) - Sunnybrook ...
Kep is an important indicator of altered blood-brain barrier permeability in patients with decreased blood flow, as Kep is flow ... Non-invasive delivery of stealth, brain-penetrating nanoparticles across the blood-brain barrier using MRI-guided focused ... Application of Blood-Brain Barrier Permeability Imaging in Global Cerebral Edema. J. Ivanidze, O.N. Kallas, A. Gupta, E. ... Application of Blood-Brain Barrier Permeability Imaging in Global Cerebral Edema. J. Ivanidze, O.N. Kallas, A. Gupta, E. ...
The zebrafish has been established as a genetic and molecular model for the blood-brain barrier. ... 2010) A novel transgenic zebrafish model for blood-brain and blood-retinal barrier development BMC Developmental Biology 10:76. ... 2008) Functional and developmental analysis of the blood-brain barrier in zebrafish Brain Research Bulletin 75:619-628. ... 2018) Bridging barriers: a comparative look at the blood-brain barrier across organisms Genes & Development 32:466-478. ...
February 24, 2023 - A grape-like structure in the brain called the choroid plexus becomes enlarged and shows increased ... Researchers detail changes in the blood-brain barrier related to Alzheimers disease The brain tissue grows and accumulates ... changes appear to be a more extreme or perturbed version of changes seen in the choroid plexus-part of the blood-brain barrier- ... The choroid plexus is a network of blood vessels and cells that produces cerebrospinal fluid (CSF) and creates a barrier ...
The blood-brain barrier is the brains gatekeeper. A nearly impenetrable shield of cells, it keeps toxins and other agents that ... into the cells that make the human blood-brain barrier (bottom), the anatomical feature that protects our brain from toxins and ... UW scientists create a recipe to make human blood-brain barrier. November 8, 2017 By Terry Devitt For news media ... chemical factors for cells to push stem cells to become the brain endothelial cells that compose the blood-brain barrier. "It ...
Foundation Hosts Roundtable on Blood-Brain Barrier Opening Published: 29 July 2021. ... The meeting covered methods for confirming and quantifying drug/therapeutic delivery following blood-brain barrier opening ( ... discussion centered on methods for confirming and quantifying drug/therapeutic delivery following blood-brain barrier opening ( ...
Behavior of α-, β-, and γ-Cyclodextrins and Their Derivatives on an in Vitro Model of Blood-Brain Barrier. V. Monnaert, S. ... Behavior of α-, β-, and γ-Cyclodextrins and Their Derivatives on an in Vitro Model of Blood-Brain Barrier. V. Monnaert, S. ... Behavior of α-, β-, and γ-Cyclodextrins and Their Derivatives on an in Vitro Model of Blood-Brain Barrier. V. Monnaert, S. ... Behavior of α-, β-, and γ-Cyclodextrins and Their Derivatives on an in Vitro Model of Blood-Brain Barrier ...
Blood-brain barrier: Ageing and microvascular disease-systematic review and meta-analysis. Author(s). ... It may arise from or contribute to insidious damage to the blood-brain barrier (BBB). We systematically reviewed the literature ...
The role of the blood-brain barrier (BBB) is to control trafficking of biomolecules and protect the brain. This function can be ... The impact of α-synuclein aggregates on blood-brain barrier integrity in the presence of neurovascular unit cells. Hamdam ... The impact of α-synuclein aggregates on blood-brain barrier integrity in the presence of neurovascular unit cells ... The impact of α-synuclein aggregates on blood-brain barrier integrity in the presence of neurovascular unit cells ...
Blood Brain Barrier Compromise with Endothelial Inflammation may Lead to Autoimmune Loss of Myelin during Multiple Sclerosis. ...
  • Not all vessels in the human brain exhibit BBB properties. (wikipedia.org)
  • Osmotic blood-brain barrier disruption: CT and radionuclide imaging. (ajnr.org)
  • PURPOSE To compare CT and radionuclide imaging of osmotic blood-brain barrier disruption. (ajnr.org)
  • To develop a quantitative method for imaging osmotic blood-brain barrier disruption and to see if iopamidol could be safely given intravenously in conjunction with blood-brain barrier disruption. (ajnr.org)
  • METHODS Forty-five blood-brain barrier disruption procedures were imaged with CT and radionuclide scans. (ajnr.org)
  • Patients were observed for adverse effects after blood-brain barrier disruption. (ajnr.org)
  • CONCLUSIONS Nonionic iodine-based contrast medium has a lower incidence of seizures when injected intravenously in conjunction with osmotic blood-brain barrier disruption than ionic contrast material. (ajnr.org)
  • Disruption or impaired function of the brain barriers will thus translate into clinical disease. (unibe.ch)
  • Pericytes: a link between Parkinson-related protein and blood-brain barrier disruption? (lu.se)
  • Disruption of the blood-brain barrier and other microvascular alterations are increasingly recognized as a common denominator of several neurodegenerative disorders. (lu.se)
  • At 4 h after MWCNT exposure, broad disruption of the blood-brain barrier (BBB) was observed across the capillary bed with the small molecule fluorescein, concomitant with reactive astrocytosis. (cdc.gov)
  • Cells in the brain called pericytes that have not been high on the list of targets for treating diseases like Alzheimer's may play a more crucial role in the development of neurodegenerative diseases than has been realized. (scienceblog.com)
  • Leaky Blood-Brain Barrier a Harbinger of Alzheimer's? (alzforum.org)
  • New USC research reveals how APOE4 - a genetic culprit for Alzheimer's disease - triggers leaks in the brain's plumbing system, allowing toxic substances to seep into the brain areas responsible for memory encoding and other cognitive functions. (scienceblog.com)
  • Zlokovic's previous research shows that people who develop early memory problems also experience the most leakage in their brain's blood vessels - independent of amyloid plaque or tau, two common contributors to Alzheimer's. (scienceblog.com)
  • The success of this research opens up the potential for delivering drug therapies to parts of the brain protected by the blood brain barrier, including researching treatments for patients with various kinds of brain tumours, Alzheimer's disease, and some psychiatric conditions. (sunnybrook.ca)
  • PHOENIX, Ariz. - February 24, 2023 - A grape-like structure in the brain called the choroid plexus becomes enlarged and shows increased accumulation of abnormal inflammatory molecular signaling in people with Alzheimer's disease, according to a new study published in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association . (tgen.org)
  • INTRODUCTION: Dysfunction of the cerebral vasculature is considered one of the key components of Alzheimer's disease (AD), but the mechanisms affecting individual brain vessels are poorly understood. (lu.se)
  • Our research is devoted to understanding the function of the different brain barriers in regulating CNS immune surveillance and how their impaired function contributes to neuroinflammatory diseases such as Multiple Sclerosis (MS) or Alzheimer's disease (AD). (unibe.ch)
  • Nevertheless, in the treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, diffuse intrinsic pontine glioma , and other brain cancers , drugs must reach CNS. (bvsalud.org)
  • Antibodies are too large to cross the blood-brain barrier, and only certain antibiotics are able to pass. (wikipedia.org)
  • Antibodies normally do not cross the blood-brain barrier (BBB) and cannot bind an intracellular cerebral antigen. (open.ac.uk)
  • Are We About to Cross the Blood-Brain Barrier, and Transform Medicine? (gizmodo.com)
  • Working with colleagues at USC, and other institutions in the LA area, Zlokovic used dynamic contrast-enhanced MRI to measure the permeability of the blood-brain barrier. (alzforum.org)
  • in this situation, factors influencing permeability of the blood-brain barrier (eg, acidosis, infection) and the amount of unbound (versus albumin-bound) bilirubin may play a role. (medscape.com)
  • As an optically transparent model organism with an endothelial blood-brain barrier (BBB), zebrafish offer a powerful tool to study the vertebrate BBB. (elifesciences.org)
  • We propose that CNS immune privilege is established by the endothelial blood-brain barrier (BBB), the epithelial blood-cerebrospinal fluid barrier (BCSFB), the blood-arachnoid barrier (BAB) and the glia limitans which divide the CNS into compartments that differ with respect to their accessibility to soluble and cellular components of the immune system. (unibe.ch)
  • The reason for a leaky blood-brain barrier (BBB) with aging may well rest with how dysregulated the HPG axis becomes after menopause and during andropause. (alzforum.org)
  • The strategies for repairing a leaky blood brain barrier are similar to the strategies for repairing a leaky gut because the causes are similar. (thefnc.com)
  • The blood-brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules (O2, CO2, hormones) and small non-polar molecules. (wikipedia.org)
  • The BBB is distinct from the quite similar blood-cerebrospinal fluid barrier, which is a function of the choroidal cells of the choroid plexus, and from the blood-retinal barrier, which can be considered a part of the whole realm of such barriers. (wikipedia.org)
  • In some cases, a drug has to be administered directly into the cerebrospinal fluid where it can enter the brain by crossing the blood-cerebrospinal fluid barrier. (wikipedia.org)
  • A new study has found fine particles of pollution in the cerebrospinal fluid of people diagnosed with brain disorders. (medicalnewstoday.com)
  • The BBB separates the blood from the extracellular cerebrospinal fluid and protects the brain from bloodborne pathogens and toxins while allowing the diffusion of oxygen, carbon dioxide, and small lipophilic molecules/ethanol [ 4 ]. (hindawi.com)
  • It correlated with damage to pericytes, specialized cells that seal blood vessels in the brain and protect neurons from toxins in the plasma, and occurred in the absence of changes to cerebrospinal fluid levels of Aβ or tau. (alzforum.org)
  • The choroid plexus is a network of blood vessels and cells that produces cerebrospinal fluid (CSF) and creates a barrier between CSF and blood circulating throughout the body. (tgen.org)
  • The cerebellar tonsils, forced through the foramen magnum, compress the brain stem and obstruct cerebrospinal fluid (CSF) flow. (msdmanuals.com)
  • Blood vessels in the vertebrate brain are composed of a single layer of endothelial cells that possess distinct functional properties that allow the passage of necessary nutrients yet prevent unwanted entry of specific toxins and pathogens into the brain. (elifesciences.org)
  • A nearly impenetrable shield of cells, it keeps toxins and other agents that may be in circulating blood from gaining access to and harming the brain. (wisc.edu)
  • A team of UW-Madison researchers has developed a tightly defined, step-by-step process to turn multipurpose stem cells (top) into the cells that make the human blood-brain barrier (bottom), the anatomical feature that protects our brain from toxins and other threats that may be in circulating blood. (wisc.edu)
  • It's the defense our bodies have created to keep toxins from passing from our blood into our brains - but it also stops medicines from making the crossing too. (gizmodo.com)
  • The blood-brain barrier has an important biological function as it protects the brain from possible toxins in the blood, supplies nutrients to brain tissues, and filters harmful compounds from the brain back into the bloodstream. (ibecbarcelona.eu)
  • However, for a lot of people the blood-brain barrier degrades, allowing harmful toxins and compounds into the brain. (thefnc.com)
  • The blood-brain barrier (BBB) plays an important role in regulating the exchange of nutrients and wastes between brain tissues and the circulatory system while concurrently preventing pathogens from entering the brain parenchyma. (nature.com)
  • The blood-brain barrier (BBB) represents a complex interface between the brain parenchyma and systemic blood circulation, strictly controlling exchange of substances between the two sites. (dissertations.se)
  • In conclusion, the beneficial effects of gelatin may be the combined results of faster healing of the blood brain barrier curtailing leakage of blood borne molecules/cells into brain parenchyma and to a modulation of the microglial population response favoring restitution of the injured tissue. (lu.se)
  • The barrier also restricts the passage of peripheral immune factors, like signaling molecules, antibodies, and immune cells, into the CNS, thus insulating the brain from damage due to peripheral immune events. (wikipedia.org)
  • In amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases, these barriers become hyperpermeable, allowing a wider variety of molecules to pass through leading to more severe and more rapidly progressing disease. (hindawi.com)
  • The BBB structure encompasses occludins, claudins, and junctional adhesion molecules to support specialized endothelial cells, forming the tight junction to prevent molecules larger than 400 Da from entering the brain 1 . (nature.com)
  • This thesis examines the transport of exogenous molecules across the blood-brain barrier (BBB), focusing on active efflux, using positron emission tomography (PET), computer simulation and modelling. (dissertations.se)
  • Last year, for instance, he and his colleagues published a study on how the herbicide glyphosate can increase pro-inflammatory molecules in the brain that may be related to neurodegeneration. (tgen.org)
  • The main advance is we now have a fully defined process that uses small molecules to guide cells through the developmental process," says University of Wisconsin-Madison Professor of Chemical and Biological Engineering Sean Palecek of the method that substitutes chemical factors for cells to push stem cells to become the brain endothelial cells that compose the blood-brain barrier. (wisc.edu)
  • By identifying specific chemical molecules that can chaperone the cells through the various stages of development to become the brain endothelial cells, the Wisconsin team, in effect, provides a recipe to standardize making the cells in quantities useful for research and things like high-throughput drug screens. (wisc.edu)
  • RESULTS: We report a lack of abnormal increase in adsorptive-mediated transcytosis of albumin and preserved paracellular barrier for fibrinogen and small molecules despite an extensive load of Aβ. (lu.se)
  • This fine-tuned cellular architecture permits the blood-to-CNS passage of crucial nutrients and metabolic molecules while prohibiting the transport of factors deleterious to brain function and most drugs. (vatinelab.com)
  • Blood-brain barrier (BBB) serves as an essential interface between central nervous system (CNS) and its periphery, allowing selective permeation of ions , gaseous molecules, and other nutrients to maintain metabolic functions of brain . (bvsalud.org)
  • it protects the brain's delicate nerve tissue by preventing many other types of molecules from entering the brain. (medlineplus.gov)
  • Microbubbles (MBs) serve as a critical catalyst to amplify local cavitation in CNS capillary lumen to facilitate focused ultrasound (FUS) to transiently open the blood-brain barrier (BBB). (nature.com)
  • Focused ultrasound (FUS) combined with microbubbles (MBs) has recently emerged as a potential approach to open the blood-brain barrier (BBB) for delivering drugs into the brain. (visualsonics.com)
  • We took a young mouse, and all we did is open the blood brain barrier and take the one protein from the blood and infuse it into the brain. (beingpatient.com)
  • The blood-brain barrier (BBB) and the blood-spinal cord barrier (BSCB) are responsible for controlling the microenvironment within neural tissues in humans. (hindawi.com)
  • Less than 24 hours after breaching the blood brain barrier, the tumour and some surrounding tissues were surgically removed and sent to pathology to measure differences in the concentration of chemotherapy that deposited in the area treated by the focused ultrasound and the area not treated. (sunnybrook.ca)
  • However, for most BBB transporters, it is still difficult to synthesize selective probes and inhibitors to enable specific evaluation of the transport activities of the target transporters, because of the effects of other transporters, including functionally unknown transporters, as well as binding to brain tissues. (aspetjournals.org)
  • This barrier has the function of separating the blood from adjacent tissues, mimicking the human blood-brain barrier. (ibecbarcelona.eu)
  • Improved brain imaging modalities, such as MRI and ultrasonography, may be emerging as instrumental tools to help clarify the complex picture of kernicterus in contrast with asymptomatic bilirubin staining of brain tissues. (medscape.com)
  • Almost three decades ago, we postulated the same hypothesis, based on histologic analysis of aged brains, demonstrating a blood brain barrier (BBB) breakdown and leakage of serum proteins in aged (but not young) human brain ( Pappolla and Andorn, 1987 ). (alzforum.org)
  • The leakage starts when cells called pericytes , which line the walls of blood vessels in the brain and maintain blood-brain barrier integrity, are damaged. (scienceblog.com)
  • Overexpression of the Parkinson-related protein, α-synuclein, leads to blood-brain barrier leakage and pericyte activation in mice. (lu.se)
  • Interestingly, changes such as pericyte activation and blood-brain-barrier leakage are already observed at the early stages of the disorder, even before behavioral changes or dopaminergic cell loss can be detected, explains Gesine Paul-Visse. (lu.se)
  • Specialized brain structures participating in sensory and secretory integration within brain neural circuits-the circumventricular organs and choroid plexus-have in contrast highly permeable capillaries. (wikipedia.org)
  • An international team of researchers, including scientists from the Translational Genomics Research Institute (TGen), part of City of Hope , show that these changes appear to be a more extreme or perturbed version of changes seen in the choroid plexus-part of the blood-brain barrier-during normal aging. (tgen.org)
  • They analyzed inflammatory signaling in the CSF, as well as structure and volume changes in the choroid plexus in postmortem brains and in patients using MRI. (tgen.org)
  • The blood-brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. (wikipedia.org)
  • Damage to pericytes, the layer of cells that wrap around blood vessels in the brain, leads to decline in cognition, and is accelerated in people who carry the APOE4 gene. (scienceblog.com)
  • Pericytes are mural cells located on the abluminal membrane of the brain endothelium, involved in BBB formation and maintenance. (dissertations.se)
  • Pericytes are uniquely positioned at the blood-brain interface. (lu.se)
  • Hence, it is possible that the dysregulation of the blood-brain barrier induced by α-synuclein depends on pericytes also in the brain. (lu.se)
  • Microvascular changes often involve pathological pericyte activation and bloodbrain barrier dysfunction. (lu.se)
  • Neurovascular dysfunction, including blood-brain barrier (BBB) breakdown and cerebral blood flow (CBF) dysregulation and reduction, is increasingly recognized as contributing to Alzheimer disease. (medscape.com)
  • This technology has the potential to enhance delivery of various kinds of therapeutic agents into the brain and has potential to benefit treatment of CNS diseases. (nature.com)
  • Special attention will be given to novel approaches to deliver therapeutic agents to the brain, including the use of BBB-peptide shuttles and monoclonal antibodies. (irbbarcelona.org)
  • The new model will permit more robust exploration of the cells, their properties and how scientists might circumvent the barrier for therapeutic purposes. (wisc.edu)
  • The meeting covered methods for confirming and quantifying drug/therapeutic delivery following blood-brain barrier opening (BBBO). (fusfoundation.org)
  • On July 14, the Foundation hosted a roundtable discussion centered on methods for confirming and quantifying drug/therapeutic delivery following blood-brain barrier opening (BBBO). (fusfoundation.org)
  • Consequently, it plays an important role in maintaining brain homeostasis and in restricting the delivery of many therapeutic and diagnostic drugs to the brain. (aspetjournals.org)
  • This layer is crucial to protecting the brain from foreign substances, but also blocks some potentially therapeutic treatments from entering the brain via orally administered drugs. (michaeljfox.org)
  • Based on the findings in recent years, we summarize the therapeutic potential of vorinostat (VOR), the first approved histone deacetylase (HDAC) inhibitor, in disorders of brain, and strategies to improve drug efficacy and reduce side effects. (amrita.edu)
  • METHODS: Here, using in vivo two-photon microscopy in superficial cortical layers and ex vivo imaging across brain regions, we characterized blood-brain barrier (BBB) function and neurovascular coupling (NVC) at the level of individual brain vessels in adult female 5xFAD mice, an aggressive amyloid-β (Aβ) model of AD. (lu.se)
  • Each person has a protective barrier that normally restricts the passage of substances from the bloodstream into the brain protecting it from toxic chemicals. (sunnybrook.ca)
  • How did you discover how blood brain barriers contribute to neurodegeneration and aging? (beingpatient.com)
  • While air pollution has often been shown to be harmful to the lungs and heart, new research suggests that airborne particulates may also be associated with brain disorders. (medicalnewstoday.com)
  • Gaining insight into these transport mechanisms is expected open the door to new general and efficient approaches to facilitate the delivery of new drugs into the brain for the treatment of CNS disorders. (irbbarcelona.org)
  • The use of nanocarriers is an intriguing approach in the development of efficacious treatment for brain disorders. (dissertations.se)
  • Breaching this barrier opens up a new frontier in treating brain disorders," says Dr. Neal Kassell, chairman of the Focused Ultrasound Foundation. (sunnybrook.ca)
  • We are encouraged by the momentum building for the use of focused ultrasound to non-invasively deliver therapies for a number of brain disorders. (sunnybrook.ca)
  • This causes inflammation in the brain and symptoms such as depression, brain fog, memory loss, and other brain-based symptoms and disorders. (thefnc.com)
  • The second stage starts when the parasite crosses the blood-brain barrier and invades the central nervous system, causing severe neurological disorders. (who.int)
  • They also used advanced neuroimaging and employed the biomarker that indicates damage to the brain's blood vessels. (scienceblog.com)
  • The blood-brain barrier is the brain's gatekeeper. (wisc.edu)
  • A critical anatomical structure, the barrier is the brain's first and most comprehensive line of defense. (wisc.edu)
  • Resveratrol can increase your brain's growth hormone, support mitochondria, and protect and restore the blood-brain barrier. (thefnc.com)
  • In the brain, the GLUT1 protein is involved in moving glucose, which is the brain's main energy source, across the blood-brain barrier. (medlineplus.gov)
  • While the blood-brain barrier (BBB) protects the brain from harmful chemicals occurring naturally in the blood, it also obstructs the transport of drugs to the brain. (scienceblog.com)
  • The blood-brain barrier (BBB) is the wall that protects our brain from foreign invaders but, at the same time, the gate that allows a myriad of metabolites to enter our central nervous system (CNS). (irbbarcelona.org)
  • These barriers are fundamental to all neurological processes as they provide the extreme nutritional demands of neural tissue, remove wastes, and maintain immune privileged status. (hindawi.com)
  • But in addition to protecting the brain, it also is involved in disease and effectively blocks many of the small-molecule drugs that might make effective therapies for a host of neurological conditions, including such things as stroke, trauma and cancer. (wisc.edu)
  • The objective of these studies was to determine if E2 influences the ability of insulin to be transported into the brain, since the receptors for both E2 and insulin are found in BBB endothelial cells. (nih.gov)
  • the device could also be adapted to different types of studies involving the pathology of the human brain, as is the case of many neurodegenerative diseases, in which the integrity of the blood-brain barrier is often compromised. (ibecbarcelona.eu)
  • Based on experiments with a mouse model, the new research demonstrated the means by which its authors believe most particulates travel to the brain: the bloodstream. (medicalnewstoday.com)
  • The experiments showed that such fine particulates in the lungs can traverse the oxygen-blood barrier to enter the bloodstream. (medicalnewstoday.com)
  • Traveling to the brain, the particles "may cross from the bloodstream through the [brain-blood barrier] without visibly damaging it for final localization in the ventricles of the brain. (medicalnewstoday.com)
  • The data suggests that up to eight times the number of fine particles may reach the brain by traveling, via the bloodstream, from the lungs than pass directly via the nose - adding new evidence on the relationship between air pollution and detrimental effects of such particles on the brain," says Professor Lynch. (medicalnewstoday.com)
  • The research team infused a chemotherapy drug, then tiny, microscopic bubbles, into the bloodstream of a patient with a malignant brain tumour. (sunnybrook.ca)
  • The idea is that this will allow the chemotherapy drug in the bloodstream to sneak through the gaps in the barrier and into any nearby tumour cells. (gizmodo.com)
  • HONG KONG & SUZHOU, CHINA & SHANGHAI--( Business Wire / Korea Newswire ) May 10, 2023 -- Zion Pharma Limited, a Chinese biotechnology company focused on the development of brain-penetrable compounds, today announced that Roche has acquired the global rights to Zion's lead program, ZN-A-1041. (newswire.co.kr)
  • Researchers at the University of Illinois at Chicago have shown for the first time that damage to a particular area of the brain and a consequent reduction in noradrenaline are associated with multiple sclerosis. (scienceblog.com)
  • A new study from researchers at the University of Birmingham in the U.K. and Chinese research institutions found that such pollution-borne toxic particles can also reach the brain. (medicalnewstoday.com)
  • Researchers have long suspected that a breached blood-brain barrier increases the risk for neuronal damage and cognitive decline, but where that breach first occurs has been a mystery. (alzforum.org)
  • Now, in the January 21 Neuron, researchers led by Berislav Zlokovic at the University of Southern California, Los Angeles, report that in older adults the blood-brain barrier first becomes compromised in subdivisions of the hippocampus. (alzforum.org)
  • The researchers then used state-of-the-art MRI-guided focused low-intensity ultrasound (sound waves) to target blood vessels in the BBB area near the tumour. (sunnybrook.ca)
  • In a report published this week (Nov. 8, 2017) in Science Advances , researchers from the University of Wisconsin-Madison detail a defined, step-by-step process to make a more exact mimic of the human blood-brain barrier in the laboratory dish. (wisc.edu)
  • With this system, researchers can study the barrier permeability to different drugs and screen the most effective ones, avoiding animal tests. (ibecbarcelona.eu)
  • Given the key importance of the BBB for normal brain functions, we believe our findings have substantial significance and will be highly interesting to researchers in the biomaterial field. (lu.se)
  • The blood-brain barrier acts effectively to protect brain tissue from circulating pathogens and other potentially toxic substances. (wikipedia.org)
  • Abnormalities in the blood-brain barrier (BBB) may be important in mediating some of the tissue damage that accompanies human immunodeficiency virus (HIV) infection of the brain, as well as in facilitating viral entry into the central nervous system. (nih.gov)
  • By intracarotid and intravenous injections into live mice, we showed that these basic VHHs are able to cross the BBB in vivo, diffuse into the brain tissue, penetrate into astrocytes, and specifically label GFAP. (open.ac.uk)
  • His plan is to to use microbubbles in the blood - basically just really small bubbles of gas - to open up the layer between blood vessels and brain tissue. (gizmodo.com)
  • Endothelial cells build up the vessel wall and control the exchange between the blood and surrounding brain tissue. (lu.se)
  • Brain herniation occurs when increased intracranial pressure causes the abnormal protrusion of brain tissue through openings in rigid intracranial barriers (eg, tentorial notch). (msdmanuals.com)
  • Because the skull is rigid after infancy, intracranial masses or swelling may increase intracranial pressure, sometimes causing protrusion (herniation) of brain tissue through one of the rigid intracranial barriers (tentorial notch, falx cerebri, foramen magnum). (msdmanuals.com)
  • Brain herniation is classified based on the structure through which tissue is herniated. (msdmanuals.com)
  • Increased intracranial pressure sometimes causes protrusion (herniation) of brain tissue through one of the rigid intracranial barriers (tentorial notch, falx cerebri, foramen magnum). (msdmanuals.com)
  • Oncologists pioneered DCE-MRI to spot blood vessels invading soft tumors. (alzforum.org)
  • One of the greatest frustrations for doctors dealing with brain tumors is called the blood brain barrier (BBB). (gizmodo.com)
  • The goal is just to get the drug to nine sites around the brain tumors. (gizmodo.com)
  • The fact that this treatment could leave the brain vulnerable up to six hours is a cause for concern - but being able to deliver medicine to brain tumors may be worth the risk. (gizmodo.com)
  • It could mean a future where we might begin treating brain tumors with drugs, rather than surgery. (gizmodo.com)
  • Investigators in Israel and Italy have developed a model of the blood-brain barrier, studies of which may lead to prevention of meningitis in newborns. (technologynetworks.com)
  • APOE4 seems to speed up the breakdown of the blood-brain barrier by activating an inflammatory pathway in blood vessels, which is associated with pericyte injury. (scienceblog.com)
  • SCOTTSDALE, Arizona - Distinctive signs of breakdown of the blood-brain barrier (BBB) are commonly evident in patients with reversible cerebral vasoconstriction syndrome (RCVS), providing potential diagnostic clues for the serious condition even in the absence of vasoconstriction. (medscape.com)
  • The study shows that in as many as 70% of patients classified as having RCVS, contrast-enhanced flare sequencing imaging showed this remarkable breakdown of the blood-brain barrier, indicating that there is activity at the capillary level and it often is present even in the absence of initial vasoconstriction," said presenter David W. Dodick, MD, professor of neurology at the Mayo Clinic in Scottsdale. (medscape.com)
  • A study led by the Institute of Bioengineering of Catalonia (IBEC) describes the development of an organ-on-a-chip that mimics the human blood-brain barrier. (ibecbarcelona.eu)
  • A recent study by the Institute of Bioengineering of Catalonia (IBEC) describes the development of an organ-on-a-chip that mimics the human blood-brain barrier. (ibecbarcelona.eu)
  • Our laboratory combines expertise in vascular biology, neuroimmunology and live cell imaging and has developed sophisticated in vitro and in vivo approaches to study immune cell interactions with the brain barriers in health and neuroinflammation. (unibe.ch)
  • Serum-borne bioactivity caused by pulmonary multiwalled carbon nanotube s induces neuroinflammation via blood-brain barrier impairment. (cdc.gov)
  • These "fluobodies" specifically labeled GFAP on murine brain sections, and a basic variant (pI=9.3) of the fusion protein VHH-GFP was able to cross the BBB and to label astrocytes in vivo. (open.ac.uk)
  • The purpose of this study was to demonstrate experimentally that alterations of in vivo transporter function at the blood-brain barrier (BBB) in disease and during pharmacotherapy can be reconstructed from in vitro data based on our established pharmacoproteomic concept of reconstructing in vivo function by integrating intrinsic transport activity per transporter molecule and absolute protein expression level at the BBB. (aspetjournals.org)
  • Quantitative targeted absolute proteomic analysis of 31 membrane proteins showed that P-glycoprotein (P-gp/mdr1a) protein expression levels were significantly increased in brain capillaries of PTZ (129%), EL (143%), and PHT mice (192%) compared with controls. (aspetjournals.org)
  • So, there's a receptor that gets activated by the blood protein, and we eliminate it from the astrocytes. (beingpatient.com)
  • The GLUT1 protein also moves glucose between cells in the brain called glia, which protect and maintain nerve cells (neurons). (medlineplus.gov)
  • Having less functional GLUT1 protein reduces the amount of glucose available to brain cells, which affects brain development and function. (medlineplus.gov)
  • PM 0.1 particles are believed to be the most hazardous to human health since they are so infinitesimal they can evade the body's defenses, internal barriers against intrusive foreign matter, and even the immune system's sentinel cells. (medicalnewstoday.com)
  • A thin layer of tightly packed cells separating the central nervous system from the body's blood stream. (michaeljfox.org)
  • Here we study how αSN-AGs affect the BBB in in vitro co-culturing models consisting of human brain endothelial hCMEC/D3 cells alone and co-cultured with astrocytes and neurons/glial cells. (biorxiv.org)
  • These drugs increase brain levels of a neurotransmitter called acetylcholine, which helps neurons communicate with each other and is involved in memory, learning and thinking. (michaeljfox.org)
  • A region deep within the brain consisting of large clusters of neurons responsible for voluntary movements such as walking and movement coordination. (michaeljfox.org)
  • The neurons are all the same, but now we're taking an aged brain and eliminating that receptor so it can't get activated. (beingpatient.com)
  • The BBB results from the selectivity of the tight junctions between the endothelial cells of brain capillaries, restricting the passage of solutes. (wikipedia.org)
  • The BBB is composed of endothelial cells restricting passage of substances from the blood more selectively than endothelial cells of capillaries elsewhere in the body. (wikipedia.org)
  • Permeable capillaries of the sensory CVOs (area postrema, subfornical organ, vascular organ of the lamina terminalis) enable rapid detection of circulating signals in systemic blood, while those of the secretory CVOs (median eminence, pineal gland, pituitary lobes) facilitate transport of brain-derived signals into the circulating blood. (wikipedia.org)
  • Consequently, the CVO permeable capillaries are the point of bidirectional blood-brain communication for neuroendocrine function. (wikipedia.org)
  • The authors of the study also tracked particles through the bodies of mice and assert that such particles in humans travel from lungs to blood, and through the brain-blood barrier. (medicalnewstoday.com)
  • Our findings indicate a conserved developmental program of barrier acquisition between zebrafish and mice. (elifesciences.org)
  • In all mice, reconstructed K p brain values agreed well with the observed values within a 1.21-fold range. (aspetjournals.org)
  • Scientists are discovering that inhaled toxic particles may be able to reach and possibly damage the brain. (medicalnewstoday.com)
  • A clumping of proteins inside cell bodies in the brain, which may be toxic. (michaeljfox.org)
  • Any nootropics supplements you use must be natural and not have any side-effects, like brain-damaging chemicals or toxic substances. (pathsofmemory.net)
  • Some of the most exciting and novel therapeutics for the treatment of malignant brain tumours are not able to reach the tumour cells because of the blood brain barrier. (sunnybrook.ca)
  • Then, the reconstructed P-gp/mdr1a functional activities were integrated with unbound fractions of verapamil in plasma and brain to reconstruct K p brain of verapamil. (aspetjournals.org)
  • A variety of imaging modalities, including structural and functional magnetic resonance imaging (MRI) and positron emission tomography (PET) studies of cerebral metabolism, have shown characteristic changes in the brain of patients with Alzheimer disease in prodromal and even presymptomatic states. (medscape.com)
  • Electron microscopy studies further reveal high levels of transcytosis in brain endothelium early in development that are suppressed later. (elifesciences.org)
  • The blood-brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system, thus protecting the brain from harmful or unwanted substances in the blood. (wikipedia.org)
  • Cells of the barrier actively transport metabolic products such as glucose across the barrier using specific transport proteins. (wikipedia.org)
  • Measurement of brain uptake of various blood-borne solutes showed that newborn endothelial cells were functionally similar to those in adults, indicating that a selective BBB is operative at birth. (wikipedia.org)
  • Circumventricular organs (CVOs) are individual structures located adjacent to the fourth ventricle or third ventricle in the brain, and are characterized by dense capillary beds with permeable endothelial cells unlike those of the blood-brain barrier. (wikipedia.org)
  • The tight junctions between endothelial cells and energy dependent transporters in the BBB influence rate and extent of drug distribution to the brain. (dissertations.se)
  • The microbubbles are smaller than red blood cells and pass harmlessly through the circulation. (sunnybrook.ca)
  • Barrier properties of brain endothelial cells are induced by extrinsic signals from other cells in the surrounding microenvironment during development ( Stewart and Wiley, 1981 ). (elifesciences.org)
  • Rudimentary models of the barrier have been created in the laboratory dish using human stem cells, but such models have depended on mixing a cocktail of cell types to elicit the complex chemical interplay that directs blank slate stem cells to become the endothelial cells that make up the blood-brain barrier. (wisc.edu)
  • The new method, he adds, will also allow industry to scale up production of the brain endothelial cells for drug discovery. (wisc.edu)
  • These released AV-ICG-NPs can be further delivered into the brain via the destructed BBB and bind with the phosphatidylserine externalized on the membrane of apoptotic cells if this occurs, leading to the prolonged detention of fluorescent signals in the brain. (visualsonics.com)
  • It includes a three-dimensional culture of different types of cells that form an endothelial barrier structure. (ibecbarcelona.eu)
  • These devices, which are modeled after microchips, contain tiny channels lined with living human organ cells and others with human blood vessel cells. (technologynetworks.com)
  • In collaboration, they investigated how a progressive accumulation of α-synuclein affects these cells and brain vasculature over time. (lu.se)
  • which is characterized by a shortage of red blood cells. (medlineplus.gov)
  • where it transports a simple sugar called glucose into cells from the blood or from other cells for use as fuel. (medlineplus.gov)
  • Our purpose was to apply blood-brain barrier permeability imaging in patients with global cerebral edema by using extended CT perfusion. (ajnr.org)
  • Extended CTP was used to evaluate blood-brain barrier permeability in patients with SAH with and without global cerebral edema. (ajnr.org)
  • K ep is an important indicator of altered blood-brain barrier permeability in patients with decreased blood flow, as K ep is flow-independent. (ajnr.org)
  • ZN-A-1041 was designed to be blood-brain-barrier-penetrant, and has the potential to treat or prevent the onset of brain metastases in patients with HER2-positive metastatic breast cancer. (newswire.co.kr)
  • Up to 50% of patients with HER2-positive metastatic breast cancer will develop brain metastasis during the course of the disease. (newswire.co.kr)
  • Our agreement with Roche is the culmination of a tremendous team effort to deliver a potentially best-in-class therapy for patients with HER2-positive breast cancer, particularly in the field of brain metastasis by virtue of the high blood-brain barrier permeability of this asset," stated Zack Cheng, M.D., Ph.D., Chairman, CEO and Co-Founder of Zion Pharma Limited. (newswire.co.kr)
  • During the treatment, the patients will be monitored with fMRI brain imaging machines to see whether the drug has crossed the BBB, aided by the vibrating microbubbles. (gizmodo.com)
  • CVOs are characterized by their highly permeable microvasculature and are involved with sensory and secretory systems within the brain [ 2 , 3 ]. (hindawi.com)
  • The brain is surrounded by a thin lining called the blood-brain barrier, which prevents harmful compounds from entering the brain while allowing helpful nutrients in and cellular debris out. (thefnc.com)
  • They will then receive an injection of microbubbles, which will spread throughout the body, including into the blood vessels that serve the brain. (gizmodo.com)
  • Scientists are reporting development of a long-sought method with the potential for getting medication through a biological barrier that surrounds the brain, where it may limit the brain damage caused by stroke. (scienceblog.com)
  • This Barcelona BioMed conference on the "Blood-Brain Barrier" will gather scientists working at the interface between chemistry, biology, biophysics, and medicine . (irbbarcelona.org)
  • Sunnybrook scientists made history this week as they used focused ultrasound to non-invasively breach the blood-brain barrier and more effectively deliver chemotherapy into the brain tumour of a patient. (sunnybrook.ca)
  • The blood-brain barrier (BBB) is a highly selective, semipermeable complex that surrounds most of the blood vessels in the brain [ 1 ], except for the circumventricular organs (CVOs) centred around the ventricles of the brain. (hindawi.com)
  • It helps your brain run more effectively- which can enhance your learning, remember and focus. (pathsofmemory.net)
  • The ingredients in this nootropic supplement will aid your brain to operate at its optimum ability to make sure that you can effectively find out new points, develop brand-new memories, and also survive your day with as little stress as possible. (cyberleaders.org)
  • Practice parameters for diagnosis and evaluation of dementia, as published by the American Academy of Neurology (AAN), consider structural brain imaging to be optimal. (medscape.com)
  • A quantitative understanding of how the molecular transport systems at the human BBB are altered in diseases is essential not only to elucidate the pathophysiological roles of the BBB in human brain, but also to aid development of effective drugs and appropriate pharmacotherapies for CNS diseases. (aspetjournals.org)
  • First author Axel Montagne and colleagues imaged 12 different regions of the brain in cognitively normal young and old adults, and in older adults with mild cognitive impairment. (alzforum.org)
  • This study sheds light on a new way of looking at this disease and possibly on treatment in people with the APOE4 gene, looking at blood vessels and improving their function to potentially slow down or arrest cognitive decline," said senior author Berislav Zlokovic , director of the Zilkha Neurogenetic Institute at the Keck School of Medicine of USC. (scienceblog.com)
  • Zlokovic, who became director of the Zilkha Neurogenetic Institute in 2012, pioneered the concept that a breakdown in the blood-brain barrier contributes to cognitive impairment and dementia. (scienceblog.com)
  • The best cognitive enhancers (smart drugs) offer a natural assistance to what you currently have, what may be the best brain-supporting supplement does not make you smarter. (pathsofmemory.net)
  • The components that remain in Alpha Brain are all-natural and also will aid you to enhance your cognitive abilities in an all-natural way. (cyberleaders.org)
  • Much of the devastation of stroke and head trauma is due to damage caused the overproduction of a substance in the brain called glutamate. (scienceblog.com)
  • Some of the more foundations include balancing your blood sugar, removing inflammatory foods and chemicals from your diet and environment, and focusing on a whole foods diet that is abundant in produce. (thefnc.com)
  • Gelatin coating of brain implants is known to provide considerable benefits in terms of reduced inflammatory sequalae and long-term neuroprotective effects. (lu.se)
  • Further separation of the central nervous system (CNS) from the cardiovascular system occurs via the blood-spinal cord barrier (BSCB). (hindawi.com)
  • Leaks in the thousands of blood vessels that infiltrate the central nervous system are no exception. (alzforum.org)
  • The blood-brain barrier (BBB) is one of the major blood-central nervous system (CNS) interfaces. (aspetjournals.org)
  • The blood brain barrier (BBB) is a highly selective barrier that shields the central nervous system (CNS) from endogenous and exogenous factors circulating in the blood that could disrupt delicate brain functioning. (vatinelab.com)
  • Any problem with the functioning of the autonomic nervous system, which controls unconscious body functions that affect the bladder, bowels, sweating, sexual function and blood pressure. (michaeljfox.org)
  • Abnormal BBB function several behavioural manifestations, such frequently occurs with brain damage. (who.int)