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

Pre-eclampsia is a common obstetric syndrome affecting about 7-10% of pregnant women. Symptoms of this syndrome: hypertension and impaired renal function appear during the second or third trimester of pregnancy. Despite intensive efforts to find mechanisms and markers induced pre-eclampsia, no specific etiological factor has been identified until now. It is known that pre-eclampsia is a placental disorder developing in two stages. The first lies in the poor placentation with acute atheroma. It seems that abnormal cell adhesion molecule (integrin) expression can contribute to inappropriate invasion of trophoblasts. Furthermore, T helper 1 type cytokines which are present in decidua of patients with pre-eclampsia can alter the trophoblast invasion. Lower expression level of HLA-G molecule in pre-eclamptic placenta can influence on the profile of cytokines which are produced in pre-eclampsia. The second stage of the disease development comprises the consequences of placental ischemia. It has been suggested that TNF-alpha is produced by ischemic placenta and causes endothelial activation. It seems that some types of pre-eclampsia can be autoimmune origin, with the autoantibodies directed against phospholipids, laminin and endothelium. The events leading to pre-eclampsia are not known, but it seems that abnormal activation of the immune system may play a role in the etiology of this disorder.
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PMID:[Immunological aspects of preeclampsia]. 1100 46

This study was designed to evaluate the possible role of cytokines (IL-1 and TNF-alpha) in the pathogenesis of pancreatic injuries induced by pancreatic ischemia-reperfusion and to evaluate the protective effect of the cytokine suppressive agent, FR167653, against pancreatic injuries. Pancreatic ischemia-reperfusion was induced in rats by ligating the celiac and caudate mesenteric arteries by small metallic clips for 45 min, after this ischemia, the metal clips were removed. Four hours after removing the metal clips, the animals were used for the experiments. In this model, mild hyperamylsemia and significant increases in pancreatic water and trypsin content were observed. Significant increases in serum IL-1 and TNF-alpha were also observed, as compared with the control rats. Pancreatic subcellular redistribution of lysosomal enzyme cathepsin B from the lysosomal fraction to the zymogen fraction was also observed. However, treatment with FR167653 at a dose of 0.5 mg/kg.hr significantly prevented all these pancreatic injuries. These results indicate that cytokines such as IL-1 and TNF-alpha might be involved in the pathogenesis of pancreatic injuries induced by ischemia-reperfusion, and that a cytokine suppressive agent might be of therapeutic value for the treatment of pancreatic ischemia.
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PMID:Cytokine Suppressive Agent Prevents Pancreatic Injuries Induced by Ischemia-Reperfusion in Rats. 1106 14

The biochemical characteristics of hemorrhagic metalloproteinases isolated from snake venoms are reviewed, together with their role in the pathogenesis of the local tissue damage characteristic of crotaline and viperine snake envenomations. Venom metalloproteinases differ in their domain structure. Some enzymes comprise only the metalloproteinase domain, others have disintegrin-like and high cysteine domains and others present, besides these domains, an additional lectin-like subunit. All of them are zinc-dependent enzymes with highly similar zinc binding environments. Some metalloproteinases induce hemorrhage by directly affecting mostly capillary blood vessels. It is suggested that hemorrhagic enzymes cleave, in a highly selective fashion, key peptide bonds of basement membrane components, thereby affecting the interaction between basement membrane and endothelial cells. As a consequence, these cells undergo a series of morphological and functional alterations in vivo, probably associated with biophysical hemodynamic factors such as tangential fluid shear stress. Eventually, gaps are formed in endothelial cells through which extravasation occurs. In addition to hemorrhage, venom metalloproteinases induce skeletal muscle damage, myonecrosis, which seems to be secondary to the ischemia that ensues in muscle tissue as a consequence of bleeding and reduced perfusion. Microvessel disruption by metalloproteinases also impairs skeletal muscle regeneration, being therefore responsible of fibrosis and permanent tissue loss after snakebites. Moreover, venom metalloproteinases participate in the degradation of extracellular matrix components and play a relevant role in the prominent local inflammatory response that characterizes snakebite envenomations, since they induce edema, activate endogenous matrix metalloproteinases (MMPs) and are capable of releasing TNF-alpha from its membrane-bound precursor. Owing to their protagonic role in the pathogenesis of local tissue damage, snake venom metalloproteinases constitute relevant targets for natural and synthetic inhibitors which may complement antivenoms in the neutralization of these effects.
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PMID:Snake venom metalloproteinases: their role in the pathogenesis of local tissue damage. 1108 14

It is well known that heat-shock proteins (HSPs) have a cytoprotective function as "molecular chaperones" when cells are exposed to several stress conditions. Geranylgeranylacetone (GGA) is an antiulcer drug that was developed in Japan and it has recently been reported to induce HSP72 in rat gastric mucosa. In this experiment, we investigated the induction of HSP72 in rat liver in response to oral administration of GGA and assessed its ability to induce tolerance to warm ischemic injury by this approach. We prepared donor rats by orally administering GGA to them and compared HSP72 expression in graft liver, survival rates, and serum TNF-alpha concentrations after liver transplantation with the findings in controls. The survival rates were significantly increased when the livers were obtained from donor rats given GGA. Western blotting revealed expression of HSP72 in graft livers given GGA, and the serum TNF-alpha levels were significantly suppressed in the rats given GGA. Oral administration of GGA induced HSP72 in graft livers, and they were better able to tolerate warm ischemic injury. Oral administration of GGA appears to provide a promising new strategy for preventing ischemia-reperfusion injury.
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PMID:Efficacy of HSP72 induction in rat liver by orally administered geranylgeranylacetone. 1111 12

Permissive hypercapnia, involving tolerance to elevated Pa(CO(2)), is associated with reduced acute lung injury (ALI), thought to result from reduced mechanical stretch, and improved outcome in ARDS. However, deliberately elevating inspired CO(2) concentration alone (therapeutic hypercapnia, TH) protects against ALI in ex vivo models. We investigated whether TH would protect against ALI in an in vivo model of lung ischemia-reperfusion (IR). Anesthetized open chest rabbits were ventilated (standard eucapnic settings), and were randomized to TH (FI(CO(2)) 0.12) versus control (FI(CO(2)) 0.00). Pa(CO(2)) and arterial pH values achieved in the TH versus CON groups were 101 +/- 3 versus 44.4 +/- 4 mm Hg and 7.10 +/- 0.03 versus 7.37 +/- 0.03, respectively. Following left lung ischemia and reperfusion, TH versus control was associated with preservation of lung mechanics, attenuation of protein leakage, reduction in pulmonary edema, and improved oxygenation. Indices of systemic protection included improved acid-base and lactate profile, in the absence of systemic hypoxemia. In the TH group, mean BALF TNF-alpha levels were 3.5% of CON levels (p < 0.01), and mean 8-isoprostane levels were 30% of CON levels (p = 0.02). Western blot analysis demonstrated reduced lung tissue nitrotyrosine in TH, indicating attenuation of tissue nitration. Finally, preliminary data suggest that TH may attenuate apoptosis following lung IR. We conclude that in the current model TH is protective versus IR lung injury and mechanisms of protection include preservation of lung mechanics, attenuation of pulmonary inflammation, and reduction of free radical mediated injury. If these findings are confirmed in additional models, TH may become a candidate for clinical testing in critical care.
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PMID:Therapeutic hypercapnia reduces pulmonary and systemic injury following in vivo lung reperfusion. 1111 2

This study investigated whether idoxifene, a selective estrogen receptor modulator (SERM), exerted protective effects against ischemia-reperfusion-induced shock. Ovariectomized rats were treated with vehicle, idoxifene, or 17beta-estradiol for 4 days. Rats were subjected to splanchnic artery occlusion (SAO) followed by reperfusion (SOA/R). In vehicle-treated rats, SAO/R resulted in hypotension, hemoconcentration, increased plasma tumor necrosis factor (TNF)-alpha levels, intestinal neutrophil accumulation, and endothelial dysfunction. 17beta-Estradiol treatment increased plasma estradiol concentration and reduced SAO/R-induced tissue injury. Idoxifene treatment had no effect on plasma estradiol concentration but reduced SAO/R-induced hemoconcentration (+8.8 +/- 1.3 vs. +14 +/- 1.3% in the vehicle group, P < 0.01), TNF-alpha production (98 +/- 3.2 vs. 214 +/- 13 pg/ml, P < 0.01), and neutrophil accumulation (0.025 +/- 0.005 vs. 0.047 +/- 0.005 U/g protein, P < 0.01). It also improved endothelial function, prolonged survival time (172 +/- 3.5 vs. 147 +/- 8 min, P < 0.01), and increased survival rate (69 vs. 23%, P < 0.01). Moreover, treatment with 17beta-estradiol or idoxifene in vivo reduced TNF-alpha-induced endothelial dysfunction in vitro. Taken together, these results demonstrated that idoxifene exerted estrogen-like, endothelial-protective, and antishock effects in ovariectomized rats, suggesting that SERMs have therapeutic potential in tissue injury resulting from ischemia-reperfusion.
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PMID:Endothelial protective and antishock effects of a selective estrogen receptor modulator in rats. 1115 89

In healthy adult rats, the test tissue that is used in the mesenteric-window angiogenesis assay is natively vascularized, lacks physiological angiogenesis, and is unperturbed by surgical intervention. Using the rat MWAA oral treatment with the nitric oxide (NO) synthase inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) enhanced the angiogenic response (compared with controls receiving the inactive enantiomer D-NAME) following i.p. injections of (i) TNF-alpha at an approximate physiological dose, (ii) Compound 48/80, which is a highly selective secretagogue causing mast-cell secretion in situ and a very strong angiogenic response, and (iii) saline of a grade not made for infusion, causing a weak angiogenic response. Angiogenesis was assessed quantitatively using microscopic morphometry and image analysis in terms of objective variables recording the microvascular spatial extension, microvascular density, number and length of microvessel segments (extending between two successive branching points) and the degree of microvessel tortuosity. The data strongly suggest that endogenous NO inhibits all three mammalian angiogenesis reactions, although to a markedly different extent. Notably, the present data are virtually the opposite of those that have been reported from other mammalian angiogenesis models, the test tissues of which display deranged homeostasis, such as surgical intervention and/or ischemia.
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PMID:Oral administration of a nitric oxide synthase inhibitor enhances de novo mammalian angiogenesis mediated by TNF-alpha, saline and mast-cell secretion. 1116 45

The systemic inflammatory response (SIRS) results from various types of injuries such as severe infection, trauma, ischemia-reperfusion and major surgery including cardiac surgery with cardio-pulmonary bypass. This response involves immune cell activation and a complex network of proinflammatory cytokines, which may induce multiple organ failure when uncontrolled. The monocyte plsys a central role in the response to infection with the release of TNF-alpha, IL-1 beta, and IL-12. In addition, monocytes present antigens to T lymphocytes. An optimal antigen presentation requires the expression of MHC class II HLA-DR on monocytes surface and of costimulatory molecules such as CD54 on monocytes and LFA-1 on lymphocytes. It has become increasingly apparent that the proinflammatory response is balanced by concomitant anti-inflammatory mechanisms that results in monocyte deactivation, characterized by a decrease in HLA-DR expression and the release of anti-inflammatory cytokines such as IL-10. This counterregulatory response, if prolonged or predominant, may predispose the patient to a higher risk of infection. Further studies need to be conducted to precise: i) the intensity of depression of the surface molocule expression assessing monocyte function, such as HLA DR and CD54; ii) the level of IL-10 and IL-12 release in patients with severe sepsis; iii) the immuno-modulating effects of frequently used treatments in these patients with severe sepsis and in surgical patients; iv) the time course of recovery; v) if the monitoring of HLA-DR, CD54, IL-10 and IL-12 will better predict the clinical outcome than clinical parameters.
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PMID:Assessment of immunological status in the critically ill. 1119 84

Proinflammatory cytokines affect nearly all tissues and organ systems, and the vasculature is no exception. Although a considerable amount of research has focused on the role of the two most prominent proinflammatory cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF), in the pathogenesis of sepsis and septic shock, the role of these and other cytokines in the pathogenesis of atherosclerotic lesions of the coronary artery, the acute ischemic event associated with myocardial infarction, the progression of myocardiopathies or the loss of myocardial function in congestive heart failure is a relatively recent discovery. Moreover, there has also been significant investigation of the cardioprotective effects of cytokines. Most of the attention has focused on the acute coronary syndromes and the myocardial suppression that takes place as a result of acute ischemia. The potential for anticytokine-based therapies in treating heart disease is great. Parenteral TNF-alpha neutralization and IL-1 receptor blockade are presently used to treat rheumatoid arthritis. Two orally effective agents, the IL-1beta-converting enzyme inhibitor and the mitogen-activating protein kinase p38 inhibitor, are currently being investigated in clinical trials.
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PMID:Proinflammatory cytokines in heart disease. 1124 92

Interleukin-12 and tumor necrosis factor (TNF)-alpha promote T-helper (Th) 1 responses and cellular immunity, whereas IL-10 suppresses Th1 activities and stimulates Th2 and humoral immune responses. Recent evidence indicates that glucocorticoids, norepinephrine, epinephrine, histamine, and adenosine inhibit the production of human IL-12 and TNF-alpha, whereas they do not affect or even stimulate the production of IL-10. Through this mechanism these neuroendocrine mediators may cause a selective suppression of Th1 responses and a Th2 shift rather than generalized Th suppression. The substantial Th2-driving force of endogenous stress mediators, as well as histamine and adenosine, can be amplified to a great extent during certain conditions and may play a role in increased susceptibility of the organism to various infections that are normally cleared by Th1 responses. In addition, conditions that contribute to a substantial increase or decrease of local or systemic concentrations of these mediators via modulation of IL-12, TNF alpha/IL-10 balance may also play a role in induction, expression, and progression of certain autoimmune diseases, allergic/atopic reactions, and tumor growth. These conditions include: acute or chronic stress; cessation of chronic stress or chronic hypoactivity of the stress system; severe exercise; serious surgical procedures or traumatic injuries; major burns; severe ischemia or hypoxia; pregnancy and the postpartum period. Thus, better understanding of the neuroendocrine regulation of IL-12, TNF-alpha/IL-10 balance might help the development of new therapeutic strategies for the treatment of Th1- and Th2-mediated human diseases.
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PMID:Neuroendocrine regulation of IL-12 and TNF-alpha/IL-10 balance. Clinical implications. 1126 24


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