AIDS Dementia Complex
Peptide T
Dementia
Acquired Immunodeficiency Syndrome
HIV-1
Zidovudine
Cycas
Brain
HIV Envelope Protein gp120
Amino Acids, Diamino
Dementia, Vascular
HIV Core Protein p24
Cerebral vasculopathy in HIV infection revealed by transcranial Doppler: A pilot study. (1/587)
BACKGROUND AND PURPOSE: There is growing evidence for affection of cerebral vessels during human immunodeficiency virus (HIV) infection. We prospectively evaluated cerebrovascular reserve capacity (CRC) in HIV-seropositive patients by transcranial Doppler sonography (TCD) after systemic administration of acetazolamide. We hypothesized that a disturbed vasoreactivity would reflect the cerebral arteries' involvement in HIV infection. METHODS: We assessed the mean blood flow velocity (BFV) of the middle cerebral artery and its increase after intravenous administration of 1 g acetazolamide (CRC) in 31 HIV-infected individuals without symptoms of cerebrovascular disease (mean+/-SD age, 39+/-11 years). Stenotic or occlusive lesions of the large brain-supplying arteries were excluded by color-coded duplex and transcranial imaging. BFV and CRC were also measured in an age-matched group of 10 healthy control subjects. Patients were classified according to clinical, laboratory, and neurophysiological parameters. We also performed cerebral MRI (n=25) and rheumatological blood tests (n=26). RESULTS: Baseline BFV and CRC both were significantly reduced in HIV-infected patients as compared with control subjects (P<0.05, Student's t test). These findings did not correlate with duration of seropositivity, helper cell count, or other clinical, rheumatological, and neuroradiological findings. CONCLUSIONS: Our findings support the hypothesis of a cerebral vasculopathy etiologically associated with HIV infection. (+info)Proton magnetic resonance spectroscopy pattern of progressive multifocal leukoencephalopathy in AIDS. (2/587)
The objective was to determine whether the use of intermediate echo times (135 ms) in proton magnetic resonance spectroscopy (1H-MRS) detects a homogenous pattern in progressive multifocal leukoencephalopathy (PML) in HIV-1 infected people, and to confirm the results of previous studies. Six patients infected with HIV-1, with PML established by biopsy, and six healthy age and sex matched volunteers were evaluated to define their spectroscopic pattern. 1H-MRS spectra performed at 1.5 T were obtained with the STEAM sequence: TE/TM/TR, 20 ms/13.7 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (STEAM-20) and with the PRESS sequence; TE/TR, 135 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (PRESS-135). A single voxel was placed on the lesions and on the parieto-occipital white matter of controls. The peaks of N-acetylaspartate (NAA), choline (Cho), myoinositol (mI), lactate, and lipids were considered, and the results were expressed using creatine as reference. Spectra of PML lesions were characterised by significantly reduced NAA, lactate presence, and by significantly increased Cho and lipids compared with control group values. These results indicate that 1H-MRS detects a homogenous pattern in PML lesions. Recent studies, together with this, suggest that 1H-MRS may help in the diagnostic approach to patients with suspected PML lesions associated with AIDS. (+info)Increased peroxynitrite activity in AIDS dementia complex: implications for the neuropathogenesis of HIV-1 infection. (3/587)
Oxidative stress is suggested to be involved in several neurodegenerative diseases. One mechanism of oxidative damage is mediated by peroxynitrite, a neurotoxic reaction product of superoxide anion and nitric oxide. Expression of two cytokines and two key enzymes that are indicative of the presence of reactive oxygen intermediates and peroxynitrite was investigated in brain tissue of AIDS patients with and without AIDS dementia complex and HIV-seronegative controls. RNA expression of IL-1beta, IL-10, inducible nitric oxide synthase, and superoxide dismutase (SOD) was found to be significantly higher in demented compared with nondemented patients. Immunohistochemical analysis showed that SOD was expressed in CD68-positive microglial cells while inducible nitric oxide synthase was detected in glial fibrillary acidic protein (GFAP)-positive astrocytes and in equal amounts in microglial cells. Approximately 70% of the HIV p24-Ag-positive macrophages did express SOD, suggesting a direct HIV-induced intracellular event. HIV-1 infection of macrophages resulted in both increased superoxide anion production and elevated SOD mRNA levels, compared with uninfected macrophages. Finally, we show that nitrotyrosine, the footprint of peroxynitrite, was found more intense and frequent in brain sections of demented patients compared with nondemented patients. These results indicate that, as a result of simultaneous production of superoxide anion and nitric oxide, peroxynitrite may contribute to the neuropathogenesis of HIV-1 infection. (+info)Rate and severity of HIV-associated dementia (HAD): correlations with Gp41 and iNOS. (4/587)
BACKGROUND: Fifteen to thirty percent of AIDS patients develop some type of neurologic disorder during the course of their illness and the vast majority of these neurologic disorders will be HIV-associated dementia (HAD). These patients can exhibit varying degrees of severity and rates of progression of HAD. Neuropathologic variables that are associated with the rate of progression of HAD are not known. MATERIALS AND METHODS: Tissue was collected at autopsy from the Johns Hopkins University HIV Neurology Program. Seventy-one AIDS patients of this prospectively characterized population were followed until death to obtain information on dementia severity and the rate of neurological progression. Immunoblot analysis of immunological nitric oxide synthase (iNOS), HAM56, gp41, p24, gp120, and beta-tubulin was performed and the levels of iNOS, HAM56, gp41, and p24 were normalized to beta-tubulin and analyzed for significance by means of the Kruskal-Wallis test for multiple groups. RESULTS: We have identified unique groups within this spectrum and designated them slow, moderate, and rapid progressors. Slow and moderate progressors' neurological progression occurs over a course of months to years, whereas the rapid progressors' disease shows rapid increases in severity over weeks to months. In the present study we demonstrate that the severity and rate of progression of HAD correlates significantly with levels of the HIV-1 coat protein, gp41, iNOS, and HAM56, a marker of microglial/macrophage activation. CONCLUSION: The severity and rate of progression of HAD correlates with indices of immune activation as well as levels of iNOS and gp41. There appears to be a threshold effect in which high levels of gp41, iNOS, and immune activation are particularly associated with severe (Memorial Sloan-Kettering score 3 to 4) and rapidly progressive HAD. (+info)The SIV-infected rhesus monkey model for HIV-associated dementia and implications for neurological diseases. (5/587)
The neuropathogenesis of human immunodeficiency virus (HIV)-associated dementia has remained elusive, despite identification of HIV as the causal agent. Although a number of contributing factors have been identified, the series of events that culminate in motor and cognitive impairments after HIV infection of the central nervous system (CNS) are still not known. Rhesus monkeys infected with simian immunodeficiency virus (SIV) manifest immunosuppression and CNS disease that is pathologically [L. R. Sharer et al. (1991) J. Med. Primatol. 20, 211-217] and behaviorally [E. A. Murray et al. (1992) Science 255, 1246-1249] similar to humans. The SIV model of HIV-associated dementia (HAD) is widely recognized as a highly relevant model in which to investigate neuropathogenesis. With better understanding of neuropathogenesis comes the opportunity to interrupt progression and to design better treatments for HAD. This becomes increasingly important as patients live longer yet still harbor HIV-infected cells in the CNS. The use of the SIV model has allowed the identification of neurochemical markers of neuropathogenesis important not only for HAD, but also for other inflammatory neurological diseases. (+info)Do alcohol and cocaine abuse alter the course of HIV-associated dementia complex? (6/587)
Although psychoactive drugs are commonly used by AIDS patients, it is unclear whether commonly abused drugs, such as cocaine and ethanol, affect the course of HIV-associated dementia (HADC). Epidemiological studies have resulted in conflicting conclusions as to what role, if any, abused drugs play in HADC. In this review we discuss the clinical and pathological evidence that cocaine and ethanol might exacerbate the detrimental effects of HIV infection on the brain. We also review studies of cocaine and ethanol effects on various components of the immune system both in the presence and absence of retroviral infection. Data from these studies indicate that cocaine and ethanol have profound effects on the immune system that, in many respects, are enhanced by retroviral infection. We conclude that abused drugs likely affect the course of HADC but that proof awaits an examination of their interactive effects in an appropriate in vivo system of retroviral encephalitis. (+info)Angiographic abnormalities in progressive multifocal leukoencephalopathy: an explanation based on neuropathologic findings. (7/587)
BACKGROUND AND PURPOSE: Progressive multifocal leukoencephalopathy (PML) is typically occult at angiography and fails to enhance on MR images. After observing angiographic abnormalities characterized by arteriovenous shunting and pathologic parenchymal blush in patients with AIDS-related PML, often in the absence of contrast enhancement on MR images, we hypothesized that there might be distinct changes in the cerebral microvasculature that account for the reduction in vascular transit time (arteriovenous shunting) in the absence of blood-brain barrier dysfunction. METHODS: The imaging studies and neuropathologic specimens of six patients with biopsy-proved PML were reviewed retrospectively. In all patients contrast-enhanced MR imaging and CT, followed by cerebral angiography, were performed before stereotactically directed biopsy. The angiograms were evaluated for the presence of vascular displacement, pathologic parenchymal blush, arteriovenous shunting, and neovascularity. The CT and MR studies were reviewed for the presence of enhancement of the PML lesions. Biopsy specimens were examined for the presence of necrosis, perivascular inflammation, and neovascularity. RESULTS: All patients had oligodendrocytic intranuclear inclusions diagnostic of PML, together with perivascular inflammation and neovascularity to a varying extent; no other neuropathologic processes were identified. Angiographic abnormalities, characterized by a pathologic parenchymal blush and arteriovenous shunting, were identified in four of the six patients. In only one of these cases, however, was abnormal enhancement identified on cross-sectional imaging studies (MR and CT), and this patient had florid perivascular inflammatory infiltrates histologically. CONCLUSION: The pathologic parenchymal blush and arteriovenous shunting seen angiographically in some patients with PML reflect small-vessel proliferation and perivascular inflammatory changes incited by the presence of the JC virus in infected oligodendrocytes. (+info)Bipolar disorder in old age. (8/587)
OBJECTIVE: To review the classification, clinical characteristics, and epidemiology of bipolar disorders in old age with a special focus on neurologic comorbidity, high mortality, and management. QUALITY OF EVIDENCE: Most available data is gleaned from retrospective chart reviews and cohort studies. Treatment recommendations are based on evidence from younger populations and a few anecdotal case reports and series involving elderly people. MAIN MESSAGE: While relatively rare in the community setting, mania in old age frequently leads to hospitalization. It is associated with late-onset neurologic disorders (especially cerebrovascular disease) involving the right hemisphere and orbitofrontal cortex. Prognosis is relatively poor; morbidity and mortality rates are high. Management of bipolarity includes cautious use of mood stabilizers, especially lithium and divalproex. CONCLUSIONS: Mania in old age should trigger a careful assessment of underlying neurologic disease, especially cerebrovascular disease. Close clinical follow up is essential. (+info)AIDS Dementia Complex (ADC) is a neurological disorder that occurs in people with advanced HIV infection or AIDS. It is also known as HIV-associated dementia (HAD) or HIV encephalopathy. ADC is characterized by cognitive impairment, motor dysfunction, and behavioral changes that can significantly affect the individual's daily functioning and quality of life.
The symptoms of AIDS Dementia Complex may include:
- Difficulty with concentration and memory
- Slowness in thinking, processing information, or making decisions
- Changes in mood or personality, such as depression, irritability, or apathy
- Difficulty with coordination, balance, or speech
- Progressive weakness and wasting of muscles
- Difficulty with swallowing or speaking
The exact cause of ADC is not fully understood, but it is believed to be related to the direct effects of HIV on the brain. The virus can infect and damage nerve cells, leading to inflammation and degeneration of brain tissue. Treatment for ADC typically involves antiretroviral therapy (ART) to control HIV replication, as well as medications to manage specific symptoms. In some cases, supportive care such as physical therapy or occupational therapy may also be recommended.
I'm sorry for any confusion, but "Peptide T" is not a widely recognized or established medical term. It appears that you might be referring to "T-20," which is also known as "Enfuvirtide." Enfuvirtide is a medication used in the treatment of HIV infection. It is a synthetic peptide that mimics a portion of the gp41 protein, which is a component of the viral envelope of HIV. By binding to this protein, enfuvirtide prevents the virus from infecting cells, providing an additional line of defense against the virus in combination therapy regimens.
If you meant something else by "Peptide T," please provide more context or clarify your question so I can give you a more accurate answer.
Dementia is a broad term that describes a decline in cognitive functioning, including memory, language, problem-solving, and judgment, severe enough to interfere with daily life. It is not a specific disease but rather a group of symptoms that may be caused by various underlying diseases or conditions. Alzheimer's disease is the most common cause of dementia, accounting for 60-80% of cases. Other causes include vascular dementia, Lewy body dementia, frontotemporal dementia, and Huntington's disease.
The symptoms of dementia can vary widely depending on the cause and the specific areas of the brain that are affected. However, common early signs of dementia may include:
* Memory loss that affects daily life
* Difficulty with familiar tasks
* Problems with language or communication
* Difficulty with visual and spatial abilities
* Misplacing things and unable to retrace steps
* Decreased or poor judgment
* Withdrawal from work or social activities
* Changes in mood or behavior
Dementia is a progressive condition, meaning that symptoms will gradually worsen over time. While there is currently no cure for dementia, early diagnosis and treatment can help slow the progression of the disease and improve quality of life for those affected.
Acquired Immunodeficiency Syndrome (AIDS) is a chronic, life-threatening condition caused by the Human Immunodeficiency Virus (HIV). AIDS is the most advanced stage of HIV infection, characterized by the significant weakening of the immune system, making the person more susceptible to various opportunistic infections and cancers.
The medical definition of AIDS includes specific criteria based on CD4+ T-cell count or the presence of certain opportunistic infections and diseases. According to the Centers for Disease Control and Prevention (CDC), a person with HIV is diagnosed with AIDS when:
1. The CD4+ T-cell count falls below 200 cells per cubic millimeter of blood (mm3) - a normal range is typically between 500 and 1,600 cells/mm3.
2. They develop one or more opportunistic infections or cancers that are indicative of advanced HIV disease, regardless of their CD4+ T-cell count.
Some examples of these opportunistic infections and cancers include:
* Pneumocystis pneumonia (PCP)
* Candidiasis (thrush) affecting the esophagus, trachea, or lungs
* Cryptococcal meningitis
* Toxoplasmosis of the brain
* Cytomegalovirus disease
* Kaposi's sarcoma
* Non-Hodgkin's lymphoma
* Invasive cervical cancer
It is important to note that with appropriate antiretroviral therapy (ART), people living with HIV can maintain their CD4+ T-cell counts, suppress viral replication, and prevent the progression to AIDS. Early diagnosis and consistent treatment are crucial for managing HIV and improving life expectancy and quality of life.
HIV-1 (Human Immunodeficiency Virus type 1) is a species of the retrovirus genus that causes acquired immunodeficiency syndrome (AIDS). It is primarily transmitted through sexual contact, exposure to infected blood or blood products, and from mother to child during pregnancy, childbirth, or breastfeeding. HIV-1 infects vital cells in the human immune system, such as CD4+ T cells, macrophages, and dendritic cells, leading to a decline in their numbers and weakening of the immune response over time. This results in the individual becoming susceptible to various opportunistic infections and cancers that ultimately cause death if left untreated. HIV-1 is the most prevalent form of HIV worldwide and has been identified as the causative agent of the global AIDS pandemic.
Zidovudine is defined as an antiretroviral medication used to prevent and treat HIV/AIDS. It is a reverse transcriptase inhibitor (NRTI) that works by blocking the action of the reverse transcriptase enzyme, thereby preventing the virus from replicating in human cells.
Zidovudine is often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) to manage HIV infection and reduce the risk of transmission. It is also used to prevent mother-to-child transmission of HIV during pregnancy, labor, delivery, and breastfeeding.
The most common side effects of zidovudine include headache, nausea, vomiting, and muscle pain. Prolonged use of zidovudine can lead to serious side effects such as anemia, neutropenia, and lactic acidosis. Therefore, regular monitoring of blood counts and liver function tests is necessary during treatment with this medication.
I'm not aware of a medical definition for the term "Cycas." It is a genus name in botany, referring to a group of plants commonly known as cycads. Cycads are ancient seed plants that have been on Earth for millions of years. They are often grown as ornamental plants due to their unique appearance.
While there may not be a direct medical definition for "Cycas," it is worth noting that some parts of the cycad plant, particularly the seeds, contain toxic compounds that can cause serious health issues in both humans and animals if ingested. These toxins can affect the nervous system, liver, and kidneys, leading to symptoms such as vomiting, seizures, and even death in severe cases.
Therefore, while "Cycas" may not have a medical definition per se, it is still important to be aware of its potential health risks.
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.
HIV Envelope Protein gp120 is a glycoprotein that is a major component of the outer envelope of the Human Immunodeficiency Virus (HIV). It plays a crucial role in the viral infection process. The "gp" stands for glycoprotein.
The gp120 protein is responsible for binding to CD4 receptors on the surface of human immune cells, particularly T-helper cells or CD4+ cells. This binding initiates the fusion process that allows the virus to enter and infect the cell.
After attachment, a series of conformational changes occur in the gp120 and another envelope protein, gp41, leading to the formation of a bridge between the viral and cell membranes, which ultimately results in the virus entering the host cell.
The gp120 protein is also one of the primary targets for HIV vaccine design due to its critical role in the infection process and its surface location, making it accessible to the immune system. However, its high variability and ability to evade the immune response have posed significant challenges in developing an effective HIV vaccine.
Diamino acids are a type of modified amino acids that contain two amino groups (-NH2) in their side chain. In regular amino acids, the side chain is composed of a specific arrangement of carbon, hydrogen, oxygen, and sometimes sulfur atoms. However, in diamino acids, one or both of the hydrogen atoms attached to the central carbon atom (alpha carbon) are replaced by amino groups.
There are two types of diamino acids: symmetric and asymmetric. Symmetric diamino acids have identical side chains on both sides of the alpha carbon atom, while asymmetric diamino acids have different side chains on each side.
Diamino acids play a crucial role in various biological processes, such as protein synthesis, cell signaling, and neurotransmission. They can be found naturally in some proteins or can be synthesized artificially for use in research and medical applications.
It is important to note that diamino acids are not one of the twenty standard amino acids that make up proteins. Instead, they are considered non-proteinogenic amino acids, which means they are not typically encoded by DNA and are not directly involved in protein synthesis. However, some modified forms of diamino acids can be found in certain proteins as a result of post-translational modifications.
Vascular dementia is a type of dementia that is caused by damage to the blood vessels that supply blood to the brain. This damage can result from conditions such as stroke, chronic high blood pressure, diabetes, or other diseases that affect the circulatory system. The interruption in blood flow to the brain can lead to damaged or dead brain cells, which can impair cognitive function and cause symptoms similar to those seen in other types of dementia, such as Alzheimer's disease.
The symptoms of vascular dementia can vary depending on the severity and location of the damage to the blood vessels. However, common symptoms include difficulties with memory, attention, and decision-making; problems with language and speech; changes in mood or behavior; and difficulty walking or performing other physical tasks. Vascular dementia is typically a progressive condition, meaning that the symptoms tend to worsen over time.
It's important to note that vascular dementia can coexist with other types of dementia, such as Alzheimer's disease, and this is known as mixed dementia. Proper diagnosis and management of underlying medical conditions that contribute to vascular dementia can help slow down the progression of cognitive decline and improve quality of life for individuals living with this condition.
HIV Core Protein p24 is a structural protein that forms the cone-shaped core of the human immunodeficiency virus (HIV). It is one of the earliest and most abundant viral proteins produced during the replication cycle of HIV. The p24 antigen is often used as a marker for HIV infection in diagnostic tests, as its levels in the blood tend to correlate with the amount of virus present.
The core protein p24 plays a critical role in the assembly and infectivity of the virus. It helps to package the viral RNA and enzymes into the virion, and is also involved in the fusion of the viral and host cell membranes during infection. The p24 protein is produced by cleavage of a larger precursor protein called Gag, which is encoded by the HIV genome.
In addition to its role in the viral life cycle, p24 has also been the target of HIV vaccine development efforts, as antibodies against this protein can neutralize the virus and prevent infection. However, developing an effective HIV vaccine has proven to be a significant challenge due to the virus's ability to mutate and evade the immune system.