Peritoneal Fibrosis
Peritoneum
Fibrosis
Chlorhexidine
Peritoneal Dialysis
Cystic Fibrosis
Dialysis Solutions
Smad Proteins, Receptor-Regulated
Sclerosis
Peritonitis
Epithelial Cells
HSP47 Heat-Shock Proteins
Transforming Growth Factor beta1
Peritoneal Cavity
Smad7 Protein
Peritoneal Dialysis, Continuous Ambulatory
Omentum
Pentoxifylline
Fibrillar Collagens
Epithelial-Mesenchymal Transition
Disease Models, Animal
Transforming Growth Factor beta
Rats, Wistar
Ultrasonics
Cells, Cultured
Cystic Fibrosis Transmembrane Conductance Regulator
Gene Transfer Techniques
Endomyocardial Fibrosis
Idiopathic Pulmonary Fibrosis
Collagen
Fibroblasts
Epithelium
Rats, Sprague-Dawley
Mesoderm
Glucose
RNA, Messenger
Liver Cirrhosis
Immunohistochemistry
Retroperitoneal Fibrosis
Gene transfer using nonviral delivery systems. (1/71)
In peritoneal dialysis, loss of peritoneal function is a major factor in treatment failure. The alterations in peritoneal function are related to structural changes in the peritoneal membrane, including peritoneal sclerosis with increased extracellular matrix. Although peritoneal sclerosis is considered reversible to some extent through peritoneal rest, which improves peritoneal function and facilitates morphological changes, there has been no therapeutic intervention and no drug against the development and progression of peritoneal sclerosis. Using recent biotechnological advances in genetic engineering, a strategy based on genetic modification of the peritoneal membrane could be a potential therapeutic maneuver against peritoneal sclerosis and peritoneal membrane failure. Before this gene therapy may be applied clinically, a safe and effective gene delivery system as well as the selection of a gene therapy method must be established. There are presently two kinds of gene transfer vectors: viral and nonviral. Viral vectors are used mainly as a gene delivery system in the field of continuous ambulatory peritoneal dialysis research; however, they have several problems such as immunogenicity and toxicity. On the other hand, nonviral vectors have several advantages over viral vectors. We review here gene transfer using nonviral vector systems in the peritoneum: electroporation, liposomes, and cationized gelatin microspheres. In the field of peritoneal dialysis, gene therapy research using nonviral vectors is presently limited. Improvement in delivery methods together with an intelligent design of targeted genes has brought about large degrees of enhancement in the efficiency, specificity, and temporal control of nonviral vectors. (+info)Is encapsulating peritoneal sclerosis a threatening issue in continuous ambulatory peritoneal dialysis? The Japanese experience. (2/71)
Encapsulating peritoneal sclerosis (EPS) is undoubtedly the most serious complication of continuous ambulatory peritoneal dialysis treatment in Japan, with a mortality rate ranging from about 39% to 49% in reported series. Cases of EPS have been linked to long-term peritoneal dialysis, and limitations on renal transplantation in Japan mean that most Japanese patients have to accept long-term dialysis therapy, which is a critical problem. Treatment alternatives for EPS include total parenteral nutrition, prednisolone administration, and surgical approaches, all of which have varying success rates. Additional therapeutic and new preventive measures have to be established for EPS. (+info)Preventing peritoneal fibrosis--insights from the laboratory. (3/71)
OBJECTIVE: Peritoneal fibrosis is one of the most serious complications of peritoneal dialysis (PD). Peritoneal fibrosis is characterized by activation of the peritoneal resident cells, accumulation and deposition of excess matrix proteins within the interstitium, and neoangiogenesis and vasculopathy of the peritoneal microvasculature. Compelling evidence now exists to show that elevated glucose concentrations present as the osmotic agent in PD solutions are, per se, responsible for those detrimental changes. Until alternative osmotic agents can fully replace glucose in PD solutions, novel therapeutic strategies are essential to preserve the structural and functional properties of the peritoneum. This review highlights recent experimental data that may offer potential strategies for preservation of the peritoneal structure and improvement of clinical outcome. METHOD: Literature review. RESULTS: Compelling evidence now exists to show that the bioincompatible nature of PD solutions--in particular, elevated glucose concentrations and glucose byproducts--play a pivotal role in the initiation of peritoneal fibrosis. Animal and in vitro studies provide some insight into methods that can potentially be employed to alleviate or retard peritoneal fibrosis. Those methods include use of alterative osmotic agents (polyglucose or amino acids), administration of TGFbeta1 antagonists, gene therapy, and pharmacologic interventions. CONCLUSIONS: Knowledge of the pathogenesis of peritoneal fibrosis has allowed independent researchers to design therapeutic strategies that abrogate excess matrix synthesis and deposition in cultured peritoneal cells and in animal models of experimental peritoneal fibrosis alike. Encouraging results have been obtained in those studies, but it remains to be determined whether the studied strategies can alleviate clinical disease. Future studies will enable us to establish specific molecules that can be targeted clinically to restrict the progressive deterioration of the peritoneal membrane as a biologic dialyzing organ. (+info)The Pan-Thames EPS study: treatment and outcomes of encapsulating peritoneal sclerosis. (4/71)
(+info)Celecoxib treatment reduces peritoneal fibrosis and angiogenesis and prevents ultrafiltration failure in experimental peritoneal dialysis. (5/71)
(+info)Tamoxifen therapy in kidney-transplant patients presenting with severe encapsulating peritoneal sclerosis after treatment for acute humoral rejection. (6/71)
OBJECTIVES: Encapsulating peritoneal sclerosis is a rare but serious complication in patients undergoing peritoneal dialysis. Its mortality rate is approximately 30%, despite treatment with total parenteral nutrition, surgery, tamoxifen, or immunosuppressants. MATERIALS AND METHODS: Of 991 kidney transplants performed at our institution over 9 years, 50 patients were treated for chronic peritoneal dialysis at the time of transplant. RESULTS: Two cases of encapsulating, peritoneal sclerosis occurred in patients receiving pretransplant peritoneal dialysis. Both had received intensive posttransplant treatment for acute humoral rejection. Encapsulating peritoneal sclerosis occurred at 3 months and 4 months after the transplant. Both presented with intestinal pain and gut obstruction. They were given total parenteral nutrition plus tamoxifen (20 mg/d) for 3 months. Outcomes were favorable for 1, though there was no improvement for the second patient, who was then also given sirolimus. He died later from multiorgan failure secondary to digestive-related sepsis, and encapsulating, peritoneal, sclerosis-related symptoms. CONCLUSIONS: When encapsulating, peritoneal sclerosis occurs after kidney transplant, tamoxifen therapy could be implemented. (+info)Prolonged peritoneal gene expression using a helper-dependent adenovirus. (7/71)
BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis. The causes of EPS are not well defined and are likely multifactorial. A suitable animal model would facilitate research into the pathophysiology and treatment of EPS. METHODS: We developed a helper-dependent adenovirus that expresses both green fluorescent protein (GFP) and active transforming growth factor-beta (TGF-beta1; HDAdTGF-beta1). Mice were administered HDAdTGF-beta1 via intraperitoneal injection and the response was compared with mice administered either first-generation adenovirus expressing TGF-beta1 (AdTGF-beta1) or control adenovirus (AdGFP). RESULTS: HDAdTGF-beta1-treated mice continued to express the GFP reporter transgene to day 74, the end of the observation period. Transgene expression lasted less than 28 days in the animals treated with first-generation adenoviruses. Animals treated with first-generation AdTGF-beta1 demonstrated submesothelial thickening and angiogenesis at day 7, with almost complete resolution by day 28. The HDAdTGF-beta1-treated mice demonstrated progressive peritoneal fibrosis with adhesion formation and encapsulation of bowels. Weight gain was significantly reduced in animals treated with HDAdTGF-beta1 compared to both the control-treated animals and the AdTGF-beta1-treated animals. Inflammation was not a major component of the fibroproliferative response. CONCLUSIONS: Peritoneal administration of a first-generation AdTGF-beta1 leads to transient gene expression, resulting in a resolving fibrotic response and histology similar to that seen in simple peritoneal sclerosis. Prolonged TGF-beta1 expression induced by the helper-dependent HDAdTGF-beta1 led to changes in peritoneal morphology resembling EPS. This suggests that TGF-beta1 may be a contributing factor in both simple peritoneal sclerosis and EPS. This model will be useful for elucidation of the mechanism of EPS and evaluation of potential treatment. (+info)Computed tomographic findings characteristic for encapsulating peritoneal sclerosis: a case-control study. (8/71)
BACKGROUND: Computed tomography (CT) is often used to confirm the diagnosis of encapsulating peritoneal sclerosis (EPS) but there is no consensus on specific CT abnormalities. To establish CT findings characteristic for EPS, we compared CT findings between EPS patients and long-term peritoneal dialysis (PD) patients without EPS. METHODS: We included as cases all EPS patients in our center from 1996 to 2008 that underwent a CT scan at the time of diagnosis. Controls were all other long-term PD patients (PD duration > or = 4 years) without EPS that had a CT scan for different reasons. The CT scans were blindly and independently reviewed by 3 radiologists: 2 abdominal radiologists with PD knowledge (Observers 1 and 2) and 1 radiologist without PD experience (Observer 3). RESULTS: We included 15 EPS patients and 16 controls. Observer 1 found 6 CT findings that were significantly more often present in EPS than in controls (p < or = 0.05): peritoneal enhancement, thickening, and calcifications; adhesions of bowel loops; signs of obstruction; and fluid loculation/septation. Observer 2 scored almost identically but Observer 3 scored differently. The sensitivity and specificity of a combination of specific CT findings were, respectively, 100% and 94% for Observers 1 and 2, and 79% and 88% for Observer 3. CONCLUSION: CT scans showed characteristic abnormalities that were significantly more often present in EPS patients compared to long-term PD control patients. CT can be used to confirm the diagnosis of EPS when experienced radiologists apply a combination of specific CT findings. (+info)Peritoneal fibrosis is a chronic condition characterized by the formation of excessive scar tissue (fibrosis) in the peritoneum, which is the thin, transparent membrane that lines the inner wall of the abdomen and covers the abdominal organs. This fibrotic process can lead to thickening and shrinkage of the peritoneum, resulting in impaired function of the affected organs and various complications.
Peritoneal fibrosis often occurs as a result of long-term exposure to dialysis solutions used during peritoneal dialysis, a type of renal replacement therapy for patients with end-stage kidney disease. The inflammatory response triggered by the dialysate can cause progressive fibrosis and thickening of the peritoneum, ultimately leading to reduced efficiency of the dialysis process and potential complications such as fluid leakage, hernias, or bowel obstruction.
In addition to peritoneal dialysis-induced fibrosis, other causes of peritoneal fibrosis include previous abdominal surgeries, intra-abdominal infections, autoimmune diseases, and certain medications. The diagnosis of peritoneal fibrosis typically involves a combination of clinical evaluation, imaging studies (such as ultrasound or CT scan), and direct examination of the peritoneum during diagnostic laparoscopy. Treatment options may include modifying the underlying cause, optimizing dialysis techniques, using anti-fibrotic medications, or considering alternative renal replacement therapies such as hemodialysis or transplantation.
The peritoneum is the serous membrane that lines the abdominal cavity and covers the abdominal organs. It is composed of a mesothelial cell monolayer supported by a thin, loose connective tissue. The peritoneum has two layers: the parietal peritoneum, which lines the abdominal wall, and the visceral peritoneum, which covers the organs.
The potential space between these two layers is called the peritoneal cavity, which contains a small amount of serous fluid that allows for the smooth movement of the organs within the cavity. The peritoneum plays an important role in the absorption and secretion of fluids and electrolytes, as well as providing a surface for the circulation of immune cells.
In addition, it also provides a route for the spread of infection or malignant cells throughout the abdominal cavity, known as peritonitis. The peritoneum is highly vascularized and innervated, making it sensitive to pain and distention.
Fibrosis is a pathological process characterized by the excessive accumulation and/or altered deposition of extracellular matrix components, particularly collagen, in various tissues and organs. This results in the formation of fibrous scar tissue that can impair organ function and structure. Fibrosis can occur as a result of chronic inflammation, tissue injury, or abnormal repair mechanisms, and it is a common feature of many diseases, including liver cirrhosis, lung fibrosis, heart failure, and kidney disease.
In medical terms, fibrosis is defined as:
"The process of producing scar tissue (consisting of collagen) in response to injury or chronic inflammation in normal connective tissue. This can lead to the thickening and stiffening of affected tissues and organs, impairing their function."
Peritoneal diseases refer to a group of conditions that affect the peritoneum, which is the thin, transparent membrane that lines the inner wall of the abdomen and covers the organs within it. The peritoneum has several functions, including providing protection and support to the abdominal organs, producing and absorbing fluids, and serving as a site for the immune system's response to infections and other foreign substances.
Peritoneal diseases can be broadly classified into two categories: infectious and non-infectious. Infectious peritoneal diseases are caused by bacterial, viral, fungal, or parasitic infections that spread to the peritoneum from other parts of the body or through contaminated food, water, or medical devices. Non-infectious peritoneal diseases, on the other hand, are not caused by infections but rather by other factors such as autoimmune disorders, cancer, or chemical irritants.
Some examples of peritoneal diseases include:
1. Peritonitis: Inflammation of the peritoneum due to bacterial or fungal infections, often caused by a ruptured appendix, perforated ulcer, or other abdominal injuries or conditions.
2. Tuberculous peritonitis: A form of peritonitis caused by Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB).
3. Peritoneal dialysis-associated peritonitis: Infection of the peritoneum in patients undergoing peritoneal dialysis, a type of kidney replacement therapy for patients with end-stage renal disease.
4. Malignant peritoneal mesothelioma: A rare and aggressive form of cancer that affects the mesothelial cells lining the peritoneum, often caused by exposure to asbestos.
5. Systemic lupus erythematosus (SLE): An autoimmune disorder that can cause inflammation and scarring of the peritoneum.
6. Peritoneal carcinomatosis: The spread of cancer cells from other parts of the body to the peritoneum, often seen in patients with advanced ovarian or colorectal cancer.
7. Cirrhotic ascites: Fluid accumulation in the peritoneal cavity due to liver cirrhosis and portal hypertension.
8. Meigs' syndrome: A rare condition characterized by the presence of a benign ovarian tumor, ascites, and pleural effusion.
Chlorhexidine is an antimicrobial agent used for its broad-spectrum germicidal properties. It is effective against bacteria, viruses, and fungi. It is commonly used as a surgical scrub, hand sanitizer, and healthcare disinfectant. Chlorhexidine is available in various forms, including solutions, gels, and sprays. It works by disrupting the microbial cell membrane, leading to the death of the organism. It is also used in mouthwashes and skin cleansers for its antimicrobial effects.
Peritoneal dialysis is a type of renal replacement therapy used to treat patients with severe kidney dysfunction or end-stage renal disease. It is a process that utilizes the peritoneum, a membranous sac lining the abdominal cavity, as a natural semipermeable membrane for filtering waste products, excess fluids, and electrolytes from the bloodstream.
In peritoneal dialysis, a sterile dialysate solution is infused into the peritoneal cavity via a permanently implanted catheter. The dialysate contains various substances such as glucose or other osmotic agents, electrolytes, and buffer solutions that facilitate the diffusion of waste products and fluids from the blood vessels surrounding the peritoneum into the dialysate.
There are two primary types of peritoneal dialysis: continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). CAPD is performed manually, several times a day, while APD is carried out using a cycler machine overnight.
Peritoneal dialysis offers certain advantages over hemodialysis, such as better preservation of residual renal function, fewer dietary restrictions, and greater flexibility in scheduling treatments. However, it also has potential complications, including peritonitis (inflammation of the peritoneum), catheter-related infections, fluid imbalances, and membrane failure over time.
Cystic fibrosis (CF) is a genetic disorder that primarily affects the lungs and digestive system. It is caused by mutations in the CFTR gene, which regulates the movement of salt and water in and out of cells. When this gene is not functioning properly, thick, sticky mucus builds up in various organs, leading to a range of symptoms.
In the lungs, this mucus can clog the airways, making it difficult to breathe and increasing the risk of lung infections. Over time, lung damage can occur, which may lead to respiratory failure. In the digestive system, the thick mucus can prevent the release of digestive enzymes from the pancreas, impairing nutrient absorption and leading to malnutrition. CF can also affect the reproductive system, liver, and other organs.
Symptoms of cystic fibrosis may include persistent coughing, wheezing, lung infections, difficulty gaining weight, greasy stools, and frequent greasy diarrhea. The severity of the disease can vary significantly among individuals, depending on the specific genetic mutations they have inherited.
Currently, there is no cure for cystic fibrosis, but treatments are available to help manage symptoms and slow the progression of the disease. These may include airway clearance techniques, medications to thin mucus, antibiotics to treat infections, enzyme replacement therapy, and a high-calorie, high-fat diet. Lung transplantation is an option for some individuals with advanced lung disease.
Dialysis solutions are fluids that are used during the process of dialysis, which is a treatment for patients with kidney failure. The main function of these solutions is to help remove waste products and excess fluid from the bloodstream, as the kidneys are no longer able to do so effectively.
The dialysis solution typically contains a mixture of water, electrolytes (such as sodium, potassium, chloride, and bicarbonate), and a small amount of glucose. The composition of the solution may vary depending on the individual patient's needs, but it is carefully controlled to match the patient's blood as closely as possible.
During dialysis, the patient's blood is circulated through a special filter called a dialyzer, which separates waste products and excess fluids from the blood. The used dialysis solution, which contains these waste products and excess fluids, is then discarded. Fresh dialysis solution is continuously introduced into the dialyzer to replace the used solution, creating a continuous flow of fluid that helps remove waste products and maintain the proper balance of electrolytes in the patient's blood.
Overall, dialysis solutions play a critical role in helping patients with kidney failure maintain their health and quality of life.
Receptor-regulated Smad proteins (R-Smads) are a subgroup of the Smad family of intracellular signaling proteins that play a critical role in mediating signals from the transforming growth factor-β (TGF-β) superfamily of cytokines and hormones. In humans, there are three types of R-Smads: Smad1, Smad2, Smad3, Smad5, and Smad8/9.
R-Smads are directly phosphorylated by the type I TGF-β receptor kinases upon ligand binding, which leads to their activation and subsequent translocation into the nucleus. Once in the nucleus, R-Smads form complexes with other transcription factors and co-regulators to regulate the expression of target genes involved in various cellular processes such as proliferation, differentiation, apoptosis, migration, and extracellular matrix production.
R-Smad signaling is tightly regulated by several mechanisms, including inhibitory Smads (I-Smads), ubiquitination, and phosphatases, to ensure proper signal transduction and prevent aberrant activation of the pathway. Dysregulation of R-Smad signaling has been implicated in various human diseases, including fibrosis, cancer, and developmental disorders.
Sclerosis is a medical term that refers to the abnormal hardening or scarring of body tissues, particularly in the context of various degenerative diseases affecting the nervous system. The term "sclerosis" comes from the Greek word "skleros," which means hard. In these conditions, the normally flexible and adaptable nerve cells or their protective coverings (myelin sheath) become rigid and inflexible due to the buildup of scar tissue or abnormal protein deposits.
There are several types of sclerosis, but one of the most well-known is multiple sclerosis (MS). In MS, the immune system mistakenly attacks the myelin sheath surrounding nerve fibers in the brain and spinal cord, leading to scarring and damage that disrupts communication between the brain and the rest of the body. This results in a wide range of symptoms, such as muscle weakness, numbness, vision problems, balance issues, and cognitive impairment.
Other conditions that involve sclerosis include:
1. Amyotrophic lateral sclerosis (ALS): Also known as Lou Gehrig's disease, ALS is a progressive neurodegenerative disorder affecting motor neurons in the brain and spinal cord, leading to muscle weakness, stiffness, and atrophy.
2. Systemic sclerosis: A rare autoimmune connective tissue disorder characterized by thickening and hardening of the skin and internal organs due to excessive collagen deposition.
3. Plaque psoriasis: A chronic inflammatory skin condition marked by red, scaly patches (plaques) resulting from rapid turnover and accumulation of skin cells.
4. Adhesive capsulitis: Also known as frozen shoulder, this condition involves stiffening and thickening of the shoulder joint's capsule due to scarring or inflammation, leading to limited mobility and pain.
Peritonitis is a medical condition characterized by inflammation of the peritoneum, which is the serous membrane that lines the inner wall of the abdominal cavity and covers the abdominal organs. The peritoneum has an important role in protecting the abdominal organs and providing a smooth surface for them to move against each other.
Peritonitis can occur as a result of bacterial or fungal infection, chemical irritation, or trauma to the abdomen. The most common cause of peritonitis is a rupture or perforation of an organ in the abdominal cavity, such as the appendix, stomach, or intestines, which allows bacteria from the gut to enter the peritoneal cavity.
Symptoms of peritonitis may include abdominal pain and tenderness, fever, nausea and vomiting, loss of appetite, and decreased bowel movements. In severe cases, peritonitis can lead to sepsis, a life-threatening condition characterized by widespread inflammation throughout the body.
Treatment for peritonitis typically involves antibiotics to treat the infection, as well as surgical intervention to repair any damage to the abdominal organs and remove any infected fluid or tissue from the peritoneal cavity. In some cases, a temporary or permanent drain may be placed in the abdomen to help remove excess fluid and promote healing.
Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.
HSP47 (Heat Shock Protein 47) is a type of molecular chaperone that assists in the proper folding and assembly of collagen molecules within the endoplasmic reticulum (ER) of eukaryotic cells. It is also known as SERPINH1, which stands for serine protease inhibitor, clade H (heat shock protein 47).
HSP47 binds to procollagen molecules in a highly specific manner and helps facilitate their correct folding and assembly into higher-order structures. Once the collagen molecules are properly assembled, HSP47 dissociates from them and allows for their transport out of the ER and further processing in the Golgi apparatus.
HSP47 is upregulated under conditions of cellular stress, such as heat shock or oxidative stress, which can lead to an accumulation of misfolded proteins within the ER. This upregulation helps to enhance the protein folding capacity of the ER and prevent the aggregation of misfolded proteins, thereby maintaining cellular homeostasis.
Defects in HSP47 function have been implicated in various connective tissue disorders, such as osteogenesis imperfecta and Ehlers-Danlos syndrome, which are characterized by abnormal collagen structure and function.
Transforming Growth Factor-beta 1 (TGF-β1) is a cytokine that belongs to the TGF-β superfamily. It is a multifunctional protein involved in various cellular processes, including cell growth, differentiation, apoptosis, and extracellular matrix production. TGF-β1 plays crucial roles in embryonic development, tissue homeostasis, and repair, as well as in pathological conditions such as fibrosis and cancer. It signals through a heteromeric complex of type I and type II serine/threonine kinase receptors, leading to the activation of intracellular signaling pathways, primarily the Smad-dependent pathway. TGF-β1 has context-dependent functions, acting as a tumor suppressor in normal and early-stage cancer cells but promoting tumor progression and metastasis in advanced cancers.
The peritoneal cavity is the potential space within the abdominal and pelvic regions, bounded by the parietal peritoneum lining the inner aspect of the abdominal and pelvic walls, and the visceral peritoneum covering the abdominal and pelvic organs. It contains a small amount of serous fluid that allows for the gliding of organs against each other during normal physiological activities such as digestion and movement. This cavity can become pathologically involved in various conditions, including inflammation, infection, hemorrhage, or neoplasia, leading to symptoms like abdominal pain, distention, or tenderness.
Smad7 protein is a intracellular signaling molecule that plays a role in negative regulation of the transforming growth factor-beta (TGF-β) superfamily of cytokines. It is a member of the Smad family, which are proteins that transduce signals from the cell membrane to the nucleus in response to TGF-β ligands binding to their receptors.
Smad7 functions as an inhibitory Smad by blocking the formation of active Smad complexes and targeting the activated type I TGF-β receptor for degradation, thus preventing the activation of TGF-β signaling pathways. It also interacts with other signaling molecules, such as tumor necrosis factor-associated factor 6 (TRAF6) and transforming growth factor-beta-activated kinase 1 (TAK1), to inhibit their activity and downregulate TGF-β signaling.
Abnormal regulation of Smad7 protein has been implicated in various human diseases, including fibrosis, cancer, and autoimmune disorders.
Peritoneal dialysis, continuous ambulatory (CAPD), is a type of renal replacement therapy used to treat patients with end-stage kidney disease. It is a form of peritoneal dialysis that is performed continuously, without the need for machines or hospitalization. CAPD uses the patient's own peritoneum, a thin membrane that lines the abdominal cavity, as a natural filter to remove waste products and excess fluids from the bloodstream.
In CAPD, a sterile dialysis solution is introduced into the peritoneal cavity through a permanent catheter implanted in the patient's abdomen. The solution remains in the peritoneal cavity for a dwell time of several hours, during which diffusion occurs across the peritoneal membrane, allowing waste products and excess fluids to move from the bloodstream into the dialysis solution.
After the dwell time, the used dialysis solution is drained from the peritoneal cavity and discarded, and a fresh batch of dialysis solution is introduced. This process is typically repeated four to five times a day, with each exchange taking about 30 minutes to complete. Patients can perform CAPD exchanges while going about their daily activities, making it a convenient and flexible treatment option for many patients with end-stage kidney disease.
Overall, CAPD is a highly effective form of dialysis that offers several advantages over other types of renal replacement therapy, including improved quality of life, better preservation of residual kidney function, and lower costs. However, it does require careful attention to sterile technique and regular monitoring to ensure proper functioning of the peritoneal membrane and adequate clearance of waste products and fluids.
The omentum, in anatomical terms, refers to a large apron-like fold of abdominal fatty tissue that hangs down from the stomach and loops over the intestines. It is divided into two portions: the greater omentum, which is larger and hangs down further, and the lesser omentum, which is smaller and connects the stomach to the liver.
The omentum has several functions in the body, including providing protection and cushioning for the abdominal organs, assisting with the immune response by containing a large number of immune cells, and helping to repair damaged tissues. It can also serve as a source of nutrients and energy for the body during times of starvation or other stressors.
In medical contexts, the omentum may be surgically mobilized and used to wrap around injured or inflamed tissues in order to promote healing and reduce the risk of infection. This technique is known as an "omentopexy" or "omentoplasty."
Pentoxifylline is a medication that belongs to a class of drugs known as xanthines. Medically, it is defined as a methylxanthine derivative that acts as a vasodilator and improves blood flow by reducing the viscosity of blood. It is used in the treatment of intermittent claudication (pain in the legs due to poor circulation) and may also be used for other conditions that benefit from improved blood flow, such as preventing kidney damage in people with diabetes.
Pentoxifylline works by increasing the flexibility of red blood cells, allowing them to move more easily through narrowed blood vessels, improving oxygen supply to tissues and organs. It also has anti-inflammatory effects that may contribute to its therapeutic benefits.
Common side effects of pentoxifylline include gastrointestinal symptoms like nausea, vomiting, and diarrhea. Less commonly, it can cause dizziness, headache, or skin rashes. Rare but serious side effects include decreased blood pressure, irregular heartbeat, and liver damage. It is essential to follow the prescribing physician's instructions carefully when taking pentoxifylline and report any unusual symptoms promptly.
Fibrillar collagens are a type of collagen that form rope-like fibrils in the extracellular matrix of connective tissues. They are composed of three polypeptide chains, called alpha chains, which are coiled together in a triple helix structure. The most common types of fibrillar collagens are Type I, II, III, V, and XI. These collagens provide strength and support to tissues such as tendons, ligaments, skin, and bones. They also play important roles in the regulation of cell behavior and tissue development. Mutations in genes encoding fibrillar collagens can lead to a variety of connective tissue disorders, including osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome.
Epithelial-mesenchymal transition (EMT) is a biological process that involves the transformation of epithelial cells into mesenchymal cells. This process is characterized by distinct changes in cell shape, behavior, and molecular markers.
Epithelial cells are typically tightly packed together and have a polarized structure with distinct apical and basal surfaces. In contrast, mesenchymal cells are elongated, spindle-shaped cells that can migrate and invade surrounding tissues.
During EMT, epithelial cells lose their polarity and cell-to-cell adhesion molecules, such as E-cadherin, and acquire mesenchymal markers, such as vimentin and N-cadherin. This transition enables the cells to become more motile and invasive, which is critical for embryonic development, wound healing, and cancer metastasis.
EMT is a complex process that involves various signaling pathways, including TGF-β, Wnt, Notch, and Hedgehog, among others. Dysregulation of EMT has been implicated in several diseases, particularly cancer, where it contributes to tumor progression, metastasis, and drug resistance.
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.
Transforming Growth Factor-beta (TGF-β) is a type of cytokine, which is a cell signaling protein involved in the regulation of various cellular processes, including cell growth, differentiation, and apoptosis (programmed cell death). TGF-β plays a critical role in embryonic development, tissue homeostasis, and wound healing. It also has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.
TGF-β exists in multiple isoforms (TGF-β1, TGF-β2, and TGF-β3) that are produced by many different cell types, including immune cells, epithelial cells, and fibroblasts. The protein is synthesized as a precursor molecule, which is cleaved to release the active TGF-β peptide. Once activated, TGF-β binds to its receptors on the cell surface, leading to the activation of intracellular signaling pathways that regulate gene expression and cell behavior.
In summary, Transforming Growth Factor-beta (TGF-β) is a multifunctional cytokine involved in various cellular processes, including cell growth, differentiation, apoptosis, embryonic development, tissue homeostasis, and wound healing. It has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.
"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.
Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.
Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.
Ultrasonics is a branch of physics and acoustics that deals with the study and application of sound waves with frequencies higher than the upper limit of human hearing, typically 20 kilohertz or above. In the field of medicine, ultrasonics is commonly used in diagnostic and therapeutic applications through the use of medical ultrasound.
Diagnostic medical ultrasound, also known as sonography, uses high-frequency sound waves to produce images of internal organs, tissues, and bodily structures. A transducer probe emits and receives sound waves that bounce off body structures and reflect back to the probe, creating echoes that are then processed into an image. This technology is widely used in various medical specialties, such as obstetrics and gynecology, cardiology, radiology, and vascular medicine, to diagnose a range of conditions and monitor the health of organs and tissues.
Therapeutic ultrasound, on the other hand, uses lower-frequency sound waves to generate heat within body tissues, promoting healing, increasing local blood flow, and reducing pain and inflammation. This modality is often used in physical therapy and rehabilitation settings to treat soft tissue injuries, joint pain, and musculoskeletal disorders.
In summary, ultrasonics in medicine refers to the use of high-frequency sound waves for diagnostic and therapeutic purposes, providing valuable information about internal body structures and facilitating healing processes.
"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.
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a protein that functions as a chloride channel in the membranes of various cells, including those in the lungs and pancreas. Mutations in the gene encoding CFTR can lead to Cystic Fibrosis, a genetic disorder characterized by thick, sticky mucus in the lungs and other organs, leading to severe respiratory and digestive problems.
CFTR is normally activated by cyclic AMP-dependent protein kinase (PKA) and regulates the movement of chloride ions across cell membranes. In Cystic Fibrosis, mutations in CFTR can result in impaired channel function or reduced amounts of functional CFTR at the cell surface, leading to an imbalance in ion transport and fluid homeostasis. This can cause the production of thick, sticky mucus that clogs the airways and leads to chronic lung infections, as well as other symptoms associated with Cystic Fibrosis.
Gene transfer techniques, also known as gene therapy, refer to medical procedures where genetic material is introduced into an individual's cells or tissues to treat or prevent diseases. This can be achieved through various methods:
1. **Viral Vectors**: The most common method uses modified viruses, such as adenoviruses, retroviruses, or lentiviruses, to carry the therapeutic gene into the target cells. The virus infects the cell and inserts the new gene into the cell's DNA.
2. **Non-Viral Vectors**: These include methods like electroporation (using electric fields to create pores in the cell membrane), gene guns (shooting gold particles coated with DNA into cells), or liposomes (tiny fatty bubbles that can enclose DNA).
3. **Direct Injection**: In some cases, the therapeutic gene can be directly injected into a specific tissue or organ.
The goal of gene transfer techniques is to supplement or replace a faulty gene with a healthy one, thereby correcting the genetic disorder. However, these techniques are still largely experimental and have their own set of challenges, including potential immune responses, issues with accurate targeting, and risks of mutations or cancer development.
Endomyocardial fibrosis is a rare heart condition characterized by the thickening and scarring (fibrosis) of the inner layer of the heart muscle (endocardium) and the muscular walls of the lower chambers of the heart (ventricles). This process can restrict the heart's ability to fill properly with blood, leading to symptoms such as shortness of breath, fatigue, and fluid retention. The exact cause of endomyocardial fibrosis is not fully understood, but it is believed to involve an abnormal immune response or inflammation. It is more commonly found in tropical regions of Africa and Asia. Treatment typically involves medications to manage symptoms and improve heart function, as well as potentially surgical interventions to remove the scar tissue and restore normal heart function.
Idiopathic Pulmonary Fibrosis (IPF) is a specific type of chronic, progressive, and irreversible fibrotic lung disease of unknown cause, characterized by scarring (fibrosis) in the lungs that thickens and stiffens the lining of the air sacs (alveoli). This makes it increasingly difficult for the lungs to transfer oxygen into the bloodstream, leading to shortness of breath, cough, decreased exercise tolerance, and, eventually, respiratory failure.
The term "idiopathic" means that the cause of the disease is unknown. The diagnosis of IPF requires a combination of clinical, radiological, and pathological findings, excluding other known causes of pulmonary fibrosis. It primarily affects middle-aged to older adults, with a higher prevalence in men than women.
The progression of IPF varies from person to person, but the prognosis is generally poor, with a median survival time of 3-5 years after diagnosis. Currently, there are two FDA-approved medications for the treatment of IPF (nintedanib and pirfenidone), which can help slow down disease progression but do not cure the condition. Lung transplantation remains an option for select patients with advanced IPF.
Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.
Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.
Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.
In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.
Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).
Epithelium is the tissue that covers the outer surface of the body, lines the internal cavities and organs, and forms various glands. It is composed of one or more layers of tightly packed cells that have a uniform shape and size, and rest on a basement membrane. Epithelial tissues are avascular, meaning they do not contain blood vessels, and are supplied with nutrients by diffusion from the underlying connective tissue.
Epithelial cells perform a variety of functions, including protection, secretion, absorption, excretion, and sensation. They can be classified based on their shape and the number of cell layers they contain. The main types of epithelium are:
1. Squamous epithelium: composed of flat, scalelike cells that fit together like tiles on a roof. It forms the lining of blood vessels, air sacs in the lungs, and the outermost layer of the skin.
2. Cuboidal epithelium: composed of cube-shaped cells with equal height and width. It is found in glands, tubules, and ducts.
3. Columnar epithelium: composed of tall, rectangular cells that are taller than they are wide. It lines the respiratory, digestive, and reproductive tracts.
4. Pseudostratified epithelium: appears stratified or layered but is actually made up of a single layer of cells that vary in height. The nuclei of these cells appear at different levels, giving the tissue a stratified appearance. It lines the respiratory and reproductive tracts.
5. Transitional epithelium: composed of several layers of cells that can stretch and change shape to accommodate changes in volume. It is found in the urinary bladder and ureters.
Epithelial tissue provides a barrier between the internal and external environments, protecting the body from physical, chemical, and biological damage. It also plays a crucial role in maintaining homeostasis by regulating the exchange of substances between the body and its environment.
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.
In medical and embryological terms, the mesoderm is one of the three primary germ layers in the very early stages of embryonic development. It forms between the ectoderm and endoderm during gastrulation, and it gives rise to a wide variety of cell types, tissues, and organs in the developing embryo.
The mesoderm contributes to the formation of structures such as:
1. The connective tissues (including tendons, ligaments, and most of the bones)
2. Muscular system (skeletal, smooth, and cardiac muscles)
3. Circulatory system (heart, blood vessels, and blood cells)
4. Excretory system (kidneys and associated structures)
5. Reproductive system (gonads, including ovaries and testes)
6. Dermis of the skin
7. Parts of the eye and inner ear
8. Several organs in the urogenital system
Dysfunctions or abnormalities in mesoderm development can lead to various congenital disorders and birth defects, highlighting its importance during embryogenesis.
Glucose is a simple monosaccharide (or single sugar) that serves as the primary source of energy for living organisms. It's a fundamental molecule in biology, often referred to as "dextrose" or "grape sugar." Glucose has the molecular formula C6H12O6 and is vital to the functioning of cells, especially those in the brain and nervous system.
In the body, glucose is derived from the digestion of carbohydrates in food, and it's transported around the body via the bloodstream to cells where it can be used for energy. Cells convert glucose into a usable form through a process called cellular respiration, which involves a series of metabolic reactions that generate adenosine triphosphate (ATP)—the main currency of energy in cells.
Glucose is also stored in the liver and muscles as glycogen, a polysaccharide (multiple sugar) that can be broken down back into glucose when needed for energy between meals or during physical activity. Maintaining appropriate blood glucose levels is crucial for overall health, and imbalances can lead to conditions such as diabetes mellitus.
Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.
Liver cirrhosis is a chronic, progressive disease characterized by the replacement of normal liver tissue with scarred (fibrotic) tissue, leading to loss of function. The scarring is caused by long-term damage from various sources such as hepatitis, alcohol abuse, nonalcoholic fatty liver disease, and other causes. As the disease advances, it can lead to complications like portal hypertension, fluid accumulation in the abdomen (ascites), impaired brain function (hepatic encephalopathy), and increased risk of liver cancer. It is generally irreversible, but early detection and treatment of underlying causes may help slow down its progression.
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.
Retroperitoneal fibrosis (RPF) is a rare and progressive condition characterized by the abnormal growth of fibrous tissue in the retroperitoneal space, which is the area behind the peritoneum (the lining that covers the abdominal cavity). This fibrous tissue can encase and compress vital structures such as the ureters, blood vessels, and nerves, leading to various symptoms.
RPF can be idiopathic (without a known cause) or secondary to other conditions like infections, malignancies, autoimmune diseases, or medications. The exact pathogenesis of RPF is not fully understood, but it's believed that an abnormal immune response and inflammation play significant roles in its development.
Symptoms of RPF may include:
1. Flank pain or back pain
2. Renal insufficiency or kidney failure due to ureteral compression
3. Hydronephrosis (dilatation of the renal pelvis and calyces)
4. Deep vein thrombosis (DVT) or pulmonary embolism (PE) due to vascular compression
5. Neurological symptoms due to nerve compression
6. Weight loss, fatigue, and fever (in some cases)
Diagnosis of RPF typically involves imaging studies such as computed tomography (CT) scans or magnetic resonance imaging (MRI), along with laboratory tests and sometimes biopsy for confirmation. Treatment options depend on the underlying cause but generally involve immunosuppressive medications, corticosteroids, and surgical intervention in severe cases.
Disease progression is the worsening or advancement of a medical condition over time. It refers to the natural course of a disease, including its development, the severity of symptoms and complications, and the impact on the patient's overall health and quality of life. Understanding disease progression is important for developing appropriate treatment plans, monitoring response to therapy, and predicting outcomes.
The rate of disease progression can vary widely depending on the type of medical condition, individual patient factors, and the effectiveness of treatment. Some diseases may progress rapidly over a short period of time, while others may progress more slowly over many years. In some cases, disease progression may be slowed or even halted with appropriate medical interventions, while in other cases, the progression may be inevitable and irreversible.
In clinical practice, healthcare providers closely monitor disease progression through regular assessments, imaging studies, and laboratory tests. This information is used to guide treatment decisions and adjust care plans as needed to optimize patient outcomes and improve quality of life.