Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Complement receptor type 2 (CR2) is a receptor that serves as an important interface between the complement system and adaptive immunity. Recent studies have shown that CR2 is also centrally involved in innate immunity, and one key area is the development of potentially pathogenic natural antibodies that target neo-epitopes revealed in ischemic tissue undergoing reperfusion. Mice lacking either total immunoglobulins or CR2 alone are protected from the development of ischemia-reperfusion injury, and this effect can be reversed by introducing CR2-sufficient B-1 cells or by transferring polyclonal natural IgM antibody from wild type mice as well as monoclonal antibodies that recognize phospholipids, DNA or non-muscle myosin. We will report at the XXI ICW an additional membrane-associated protein to which pathogenic IgM antibodies are directed. Whether B cells producing these natural antibodies are differentially selected in CR2-deficient mice is as yet not well understood, and the complement-related mechanism(s) whereby this differential repertoire selection process could occur have yet to be explored in any detail. In addition to this important role in innate immunity, CR2 can also act as a receptor for other components or activators of innate immunity. One such component is interferon-alpha, an anti-viral cytokine that binds CR2 and induces a component of its mRNA signature in B cells through this receptor. Other potential CR2 ligands are DNA and DNA-containing complexes such as chromatin. The biologic role of these CR2 interactions with interferon-alpha and DNA-containing complexes is not well understood, but may be important in the development of the autoimmune disease systemic lupus erythematosus that is characterized by enhanced interferon-alpha levels and loss of self tolerance to DNA-containing self antigens.
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PMID:Complement receptor 2, natural antibodies and innate immunity: Inter-relationships in B cell selection and activation. 1687 64

Systemic scleroderma is an autoimmune disease, due to a connective tissue alteration characterized by extracellular matrix increase in the skin and internal organs. It is already known that the Raynaud's phenomenon and the microcapillary obliteration lead to ischemia and peripheral tissue injury. The ischemia-reperfusion phenomenon releases free radicals, that react with red blood cells (RBCs) membrane components originating lipid peroxidation and impairment of the ATP-Ca(++) pump, two possible mechanisms responsible of disease pathogenesis. Nifedipine is a Ca(++)-channel antagonist that has been used for a long time in Raynaud's phenomenon treatment. In the present study we were able to demonstrate that erythrocyte deformability and two other related variables such as membrane fluidity and osmotic fragility improve significantly with nifedipine therapy. It is likely that nifedipine inhibiting cytoplasmic calcium accumulation could restore some red blood cell membrane properties.
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PMID:Nifedipine effect on red cell rheological properties in patients with systemic scleroderma. 1732 34

Natural Abs and autoantibodies bind antigens displayed by ischemia-conditioned tissues, followed by complement activation and enhanced tissue injury during reperfusion. Anti-ribonucleoprotein (RNP) Ab is associated with lung disease in patients with autoimmune disease but it is not known whether these abs contribute to lung injury. Mesenteric I/R in mice leads to local and remote lung injury. Accordingly, we used this model to investigate whether anti-RNP Abs would reconstitute I/R damage with prominent lung damage in injury-resistant Rag1(-/-) animals. Rag1(-/-) mice injected with anti-RNP Ab containing serum and subjected to mesenteric I/R suffered greater intestinal injury than control-treated and sham-operated animals. The magnitude of the reconstituted damage was anti-RNP Ab titer-dependent. Anti-RNP Ab-treated animals demonstrated a dose-dependent increase in lung histologic injury scores compared to control and sham animals. Anti-RNP mediated injury was shown to be complement dependent. These experiments reveal a novel mechanism whereby anti-RNP Abs contributes to the development of pulmonary pathology in patients with autoimmune diseases following exposure of remote organs to I/R injury.
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PMID:Anti-ribonucleoprotein antibodies mediate enhanced lung injury following mesenteric ischemia/reperfusion in Rag-1(-/-) mice. 1745 20

Systemic sclerosis (SSc, scleroderma) is an autoimmune disease characterized by excessive extracellular matrix deposition and vascular injury in the skin and internal organs. Although the pathogenesis remains unclear, Raynaud's phenomenon, a kind of ischemia-reperfusion, usually precedes the development of skin sclerosis. Therefore, it is possible that endothelial cell injury caused by recurring ischemia-reperfusion induces inflammatory cell infiltration and subsequent cytokine production, leading to the development of tissue fibrosis. During this process, chemokines likely have important roles via mediating chemotaxis and activation of leukocytes, result in the interaction between leukocytes and fibroblasts. While chemokine abnormalities of SSc have been reported in amounts of literatures, monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor, CCR2, likely have the most critical role for the development of SSc. Here recent data will be reviewed on the potential role of chemokines and their receptors in SSc.
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PMID:The roles of chemokines in the development of systemic sclerosis. 1831 Oct 40

Systemic lupus erythematosus (SLE) is a multisystem disorder with numerous potential adverse effects on the cardiovascular system. These complications likely develop in most patients with SLE at some time during the course of their disease, in part due to the decreased mortality associated with SLE as a result of modem medical management. Conduction disturbances have been reported in the literature to occur primarily from the progression of SLE and secondarily from pharmacotherapy used to treat SLE and may first be evident on the electrocardiogram in the emergency department (ED) setting. Electrocardiogram abnormalities such as borderline first-degree heart block may be clues to more significant cardiac disease brought upon by years of chronic inflammation, myocarditis, vasculitis, and fibrosis that are often the result of longstanding autoimmune disease. It is essential that patients with autoimmune disease be screened carefully in the ED setting for underlying myocardial disease, particularly given the increased potential for atherosclerosis, ischemia, arrhythmias, and myocardial conduction defects in these patients.
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PMID:Rapid progression of atrioventricular nodal blockade in a patient with systemic lupus erythematosus. 1892 71

Recent research has led to a better but as yet incomplete understanding of the complex roles osteopontin plays in mammalian physiology. A soluble protein found in all body fluids, it stimulates signal transduction pathways (via integrins and CD44 variants) similar to those stimulated by components of the extracellular matrix. This appears to promote the survival of cells exposed to potentially lethal insults such as ischemia/reperfusion or physical/chemical trauma. OPN is chemotactic for many cell types including macrophages, dendritic cells, and T cells; it enhances B lymphocyte immunoglobulin production and proliferation. In inflammatory situations it stimulates both pro- and anti-inflammatory processes, which on balance can be either beneficial or harmful depending on what other inputs the cell is receiving. OPN influences cell-mediated immunity and has been shown to have Th1-cytokine functions. OPN deficiency is linked to a reduced Th1 immune response in infectious diseases, autoimmunity and delayed type hypersensitivity. OPN's role in the central nervous system and in stress responses has also emerged as an important aspect related to its cytoprotective and immune functions. Evidence suggests that either OPN or anti-OPN monoclonal antibodies (depending on the circumstances) might be clinically useful in modulating OPN function. Manipulation of plasma OPN levels may be useful in the treatment of autoimmune disease, cancer metastasis, osteoporosis and some forms of stress.
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PMID:Osteopontin: role in immune regulation and stress responses. 1895 87

Nodular regenerative hyperplasia (NRH) of the liver is a rare disease that is characterized by multiple regenerative nodules in the hepatic parenchyma that may lead to noncirrhotic portal hypertension. The exact pathogenesis of NRH has not been established, but it has been suggested that a primary vascular abnormality causing local ischemia may initiate the nodular transformation. It is also known that this condition is associated with autoimmune disease, hematological disease, and some chemotherapy agents in which vasculopathy is a prominent feature. The patients with NRH are usually asymptomatic unless they develop complications related to portal hypertension. We report a case of a middle-aged female patient with florid carcinoid syndrome, speculating that vasoactive hormones including serotonin secreted by the tumor caused intrahepatic microcirculatory disturbances that eventually induced NRH. This association has not been reported earlier.
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PMID:Hepatic nodular regenerative hyperplasia in a patient with advanced carcinoid tumor. 1931 67

The growing numbers of potential transplant recipients on waiting lists is increasingly disproportionate to the supply of cadaveric donor organs. The hope for the next 20 years is that supply will satisfy demand. This requires both a reduction in indications for the procedure and an increase in the transplants performed. A multi-pronged approach is needed to increase cadaveric organ donation, generating enthusiasm for donation among both the general public and hospital staff. Accurate assessment of marginal grafts with stringent criteria known to predict graft function will diminish wastage of organs. Methods of rehabilitating marginal grafts during extracorporeal perfusion will increase organ availability. Supply of non-heart beating donors can be greatly expanded and protocols developed with ethical consent to optimize their initial function despite warm ischemia. Splitting livers that fulfill selection criteria, thus providing for two recipients, should be universally applied with acceptable incentives to those units who do not directly benefit. A proportion of recipients, though not those transplanted for autoimmune disease, will be spared the side-effects of immunosuppression thanks to immune tolerance. Protocols for close monitoring of those patients for rejection during treatment withdrawal must be carefully observed. In addition to gene therapy, it is highly likely that hepatocyte transplantation will replace orthotopic grafting in patients without cirrhosis, especially for inherited metabolic diseases. It is much more difficult to envisage that heterologous stem cell transplantation or xenotransplantation will have clinical impact in the next 20 years, although research in those areas has obvious long-term potential.
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PMID:Liver transplantation: Issues for the next 20 years. 1979 90

The complement system consists of about 35-40 proteins and glycoproteins present in blood plasma or on cell surfaces. Its main biological function is to recognise "foreign" particles and macromolecules, and to promote their elimination either by opsonisation or lysis. Although historically complement has been studied as a system for immune defence against bacteria, it has an important homeostatic role in which it recognises damaged or altered "self" components. Thus complement has major roles in both immune defence against microorganisms, and in clearance of damaged or "used" host components. Since complement proteins opsonise or lyse cells, complement can damage healthy host cells and tissues. The system is regulated by many endogenous regulatory proteins. Regulation is sometimes imperfect and both too much and too little complement activation is associated with many diseases. Excessive or inappropriate activation can cause tissue damage in diseases such as rheumatoid arthritis, age-related macular degeneration (AMD), multiple sclerosis, ischemia-reperfusion injury (e.g. ischemic stroke). Insufficient complement activity is associated with susceptibility to infection (mainly bacterial) and development of autoimmune disease, like SLE (systemic lupus erythematosus).
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PMID:Complement in health and disease. 2170 94

Ovarian failure is commonly caused by aging, autoimmune disease, menopause and cancer therapy. We used an ischemic model in the ovary to test the hypothesis that stem cells are helpful for ovarian regeneration after injury. Three treatment regimes were employed: sham-operated control, ligation plus PBS, and ligation plus immortalized human bone marrow stromal cells (stem cells) groups. After ligation-induced ischemia, stem cells or PBS were injected into rat ovaries. Then, pregnant mare serum gonadotropin was given intra-peritoneally to initiate folliculogenesis. The animals were then sacrificed. The ovary gland was weighed, and ovarian folliculogenesis, stem cell differentiation and vascular neogenesis were evaluated. In order to study improvement of folliculogenesis after ovarian ischemia, steroidogenic acute regulatory protein (StAR), p44/p42 MAPK (T-ERK1/2), and phospho-p44/ p42 MAPK (P-ERK1/2) expression were specifically evaluated. Results indicated that ovarian size was smaller and that the rate of folliculogenesis was lower in ovarian ischemic-reperfusion animals, but both recovered after stem cell treatment. The stem cells migrated into the ovary and differentiated into theca cells, granulosa cells, corona radiata cells and vascular endothelial cells. In addition, von Willebrand factor (vWF) expression was increased; 17beta-estradiol (E2), progesterone (P4), P-ERK1/2 and StAR protein expression was recovered by stem cells treatment in the ischemic ovaries. The serum LH was significantly increased in ovaries of ischemia-reperfusion animals, but the stem cell treatment restored the effects. These results suggest that stem cells might be helpful for ovarian regeneration after injuries by promoting vascular neogenesis and steroidogenesis through the MAPK pathway.
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PMID:Involvement of ERK phosphorylation in the prevention of ischemia-induced ovarian follicular depletion by stem cells. 2179 25


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