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)

Thrombotic thrombocytopenic purpura (TTP) is a severe, occlusive, thrombotic microangiopathy characterized by a systemic platelet aggregation, organ ischemia, profound thrombocytopenia and erythrocyte fragmentation. Recent observations have documented that a deficiency of a von Willebrand factor (VWF)-cleaving protease, termed ADAMTS13, that normally cleaves hyper-reactive unusually large VWF multimers into smaller and less adhesive VWF forms, may be responsible for many cases of TTP. Multiple mutations of the ADAMTS13 gene can result in ADAMTS13 deficiency and cause congenital TTP, while autoantibodies neutralizing ADAMTS13 protease activity have been associated with acquired TTP. However, in spite of the recent progresses in the pathophysiology of TTP, many aspects of this disease remain still controversial. In this study, basing on the laboratory results of a group of eight patients with an acquired form of TTP, an alternative pathogenic mechanism for TTP involving Helicobacter pylori infection is proposed. In fact, Helicobacter pylori, which has been recently implied in the pathogenesis of idiopathic thrombocytopenic purpura (ITP), could function as a triggering factor in TTP by inducing platelet aggregation through an interaction with VWF.
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PMID:Thrombotic thrombocytopenic purpura: proposal of a new pathogenic mechanism involving Helicobacter pylori infection. 1608 70

Polyethylene glycol (PEG) has been shown to repair cell membranes and, thus, inhibit free radical production in in vitro and in vivo models. We hypothesized that PEG and newly developed organic nitrate forms of PEG (PEG-NO) could repair endothelial dysfunction in ischemia-reperfusion (I/R) injury in the hamster cheek pouch visualized by intravital fluorescent microscopy. After treatments, we evaluated diameter and RBC velocity and flow in arterioles, as well as lipid peroxides in the systemic blood, perfused capillary length, vascular permeability, leukocyte adhesion, and amount of von Willebrand factor (vWF) in the blood after I/R injury. A control group was treated with 5,000- or 10,000-Da PEG, and three groups were treated with PG1 (1 NO molecule covalently bound to PEG, 5,170 Da), PG8 (8 NO molecules covalently bound to PEG, 11,860 Da), and PG16 (16 NO molecules covalently bound to PEG, 14,060 Da). All animals received 0.5 mg/0.5 ml. Lipid peroxides increased at 5 and 15 min of reperfusion, whereas diameter, RBC velocity, and blood flow decreased in arterioles after I/R injury. Vascular permeability, leukocyte adhesion, and vWF increased significantly. PEG and PG1 attenuated lipid peroxides and vasoconstriction during reperfusion and decreased leukocyte adhesion and vascular permeability. PG8 maintained lipid peroxides at normal levels, increased arteriolar diameter, flow, and perfused capillary length, and decreased vWF level and leukocyte adhesion (P < 0.05). PG16 was less effective than PG1 and PG8. In conclusion, PEG-NO shows promise as a compound that protects microvascular perfusion by normalizing the balance between NO level and excessive production of free radicals in endothelial cells during I/R injury.
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PMID:Polyethylene glycol and a novel developed polyethylene glycol-nitric oxide normalize arteriolar response and oxidative stress in ischemia-reperfusion. 1648 7

A disintegrin-like and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) is a metalloproteinase that specifically cleaves the multimeric von Willebrand factor (VWF). Deficiency of ADAMTS13 increases the unusually large VWF multimers (UL-VWFM), which leads to platelet clumping and/or thrombus formation, resulting in microcirculatory disturbance. We serially determined the activity of plasma ADAMTS13, together with VWF antigen (VWF:Ag) and UL-VWFM, in association with the development of early graft dysfunction in 3 liver transplant recipients and 4 patients with major hepatectomy as controls. In case 1, ADAMTS13 activity decreased markedly from 108% to less than 3% with concomitant thrombocytopenia on posttransplantation day 7, when acute rejection occurred. Simultaneously, UL-VWFM were detected. During the second episode of rejection, VWF:Ag increased to 368% with the appearance of UL-VWFM, while ADAMTS13 activity was as low as 18%, indicating an imbalance between a large amount of UL-VWFM and low activity of ADAMTS13. Administration of fresh frozen plasma (FFP) together with treatment for acute rejection resulted in an improvement of ADAMTS13 activity and disappearance of the UL-VWFM. In case 2, ADAMTS13 activity promptly decreased to 9% with thrombocytopenia on day 1, when ischemia-reperfusion injury occurred. Subsequently, the ADAMTS13 activity increased steadily without appearance of UL-VWFM, and the patient recovered uneventfully. ADAMTS13 activity decreased to 15% immediately after transplantation in case 3 as well. In contrast, ADAMTS13 activity never decreased below 20% in 4 patients with major hepatectomy as controls. In conclusion, these results indicate that the kinetics of ADAMTS13 and UL-VWFM could be good indicators of adverse events after liver transplantation. Our findings not only suggest a novel mechanism for thrombocytopenia, but also provide a useful tool for diagnosis of graft dysfunction in the early stage after transplantation.
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PMID:Plasma ADAMTS13 activity may predict early adverse events in living donor liver transplantation: observations in 3 cases. 1652 12

Increased oxidative stress and vascular inflammation have been shown in patients with cardiac syndrome X (CSX; angina, exercise-induced ischemia, and normal coronary angiogram). This study was conducted to assess the impact of basal superoxide generation by circulating mononuclear cells (MNCs), a contributor to intravascular oxidative stress, and serum inflammatory biomarkers, including high-sensitivity C-reactive protein, homocysteine, soluble intercellular adhesion molecule-1, soluble vascular adhesion molecule-1, and von Willebrand factor, on the long-term prognosis of CSX. During a mean follow-up of 31.5 +/- 14.2 months (maximum 5 years), a total of 12 events were recorded in 92 consecutive CSX patients. There were no deaths or myocardial infarctions, but 8 hospitalizations for acute coronary syndrome, 3 for stroke, and 1 for congestive heart failure due to left ventricular systolic dysfunction. Under univariate analysis, only basal superoxide generation by MNCs was associated with the risk for cardiovascular event. Based on multivariate analysis, basal superoxide generation by MNCs could still independently predict future events (relative risk for the highest compared to the lowest tertile, 3.87; 95% confidence interval, 1.42-10.54, p = 0.008). These findings demonstrate that long-term prognosis is fair in patients with CSX. Basal superoxide production of MNCs independently predicts future cardiovascular events, suggesting its potential role in measuring disease progression and risk stratification in these patients.
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PMID:Circulating mononuclear superoxide production and inflammatory markers for long-term prognosis in patients with cardiac syndrome X. 1654 Mar 94

Morbidity and mortality of peripheral arterial occlusive disease significantly increases with age, often exhibiting more severe disease pathology and decreased treatment effectiveness. Therapeutic angiogenesis with angiogenic growth factors may represent a valuable treatment option for the severely ill, older adult patient population. Aging is considered an independent cardiovascular risk factor, but pathomechanistically it is not well understood. Diminished endothelial nitric oxide (EDNO) production has been considered as a major contributor to the aging process. To investigate the effect of age on postischemic revascularization independent of changes in EDNO, we used endothelial nitric oxide synthase-deficient (ecNOS-KO) mice. We found an age-dependent acceleration in ischemic injury following unilateral femoral artery ligation in these animals compared to C57BL/J6 mice. Postischemic revascularization, quantified by measuring von Willebrand factor expression, was significantly impaired, suggesting that factors other than progressive EDNO deterioration are also involved in the age-dependent severe disease phenotype. Ischemia led to an increase in the expression of vascular endothelial growth factor receptor-2, KDR, in younger ecNOS-KO; however, this increase in KDR expression was absent in the older animals. Lack of increased KDR expression may provide a mechanistic explanation for the severe ischemic injury and perhaps can be used as a clinical marker to identify severe, vascular endothelial growth factor refractory patient population.
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PMID:Age-dependent acceleration of ischemic injury in endothelial nitric oxide synthase-deficient mice: potential role of impaired VEGF receptor 2 expression. 1668 73

The hierarchy of endothelial progenitor cells (EPCs) in human umbilical cord blood has been disclosed. In this study we compare, for the first time, the angiogenic potential difference between two types of EPCs. We cultured mononuclear cells (MNCs) isolated from human umbilical cord blood using endothelial cell-conditioned medium and obtained two types of EPCs, referred to as circulating angiogenic cells (CACs) and high proliferative potential endothelial progenitor cells (HPP-EPCs). Both types of cells possess characteristics of EPCs, including expressing CD31, VE-cadherin, KDR and von Willebrand factor, uptake of Ac-LDL and binding to lectin. However, unlike CACs, which express CD14 but not CD133, HPP-EPCs express CD133 but not CD14. Also, unlike CACs, HPP-EPCs display stronger proliferation and clonogenic potential in vitro and show stronger ability to promote vascular growth in the hind-limb model of ischemia in mice (BALB/C-nu) in vivo.
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PMID:Angiogenic potential difference between two types of endothelial progenitor cells from human umbilical cord blood. 1702 Aug 9

Several studies have stressed the involvement of inflammation in the pathophysiology of acute brain ischemia, but the role of immunoinflammatory activation in diabetic stroke patients has not yet been fully evaluated. The aim of our study was to evaluate immunoinflammatory activation of acute phase of stroke in relation to time of symptoms onset, diabetic state and diagnostic subtype. We enrolled 60 patients (32 diabetics; 28 non- diabetics) with acute ischemic stroke and 123 subjects without acute ischemic stroke, and measured levels of IL-1beta, TNF-alpha IL-6, IL-10, E-selectin, P-selectin, sICAM-1, sVCAM-1, VWF, 24-72 h and 7-10 days after stroke onset; TPA, PAI-1 plasma levels at 24-72h. Our stroke patients exhibited significantly higher plasma levels of cytokines, selectins, adhesion molecules and PAI-1, and diabetic stroke patients exhibited higher plasma levels of PAI-1 in comparison with non-diabetic ones. Lacunar strokes in comparison with those non-lacunar exhibited significantly lower levels of TNF-alpha and IL1-beta P-selectin and ICAM-1. Moreover, diabetic patients with lacunar strokes exhibited a minor grade of immunoinflammatory activation of the acute phase at 24-72h and 7-10 days after stroke onset. The minor grade of immunoinflammatory activation of patients with lacunar strokes, particularly diabetic ones, could be related to the minor extension of the infarct size, owing to the typical microvascular disease of diabetic subjects which could also explain the reported better outcome of this subtype of ischemic stroke.
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PMID:Immunoinflammatory activation during the acute phase of lacunar and non-lacunar ischemic stroke: association with time of onset and diabetic state. 1702 49

During this investigation, a model of tourniquet-induced forearm ischaemia-reperfusion injury is employed to investigate the role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury. Leucocyte entrapment is investigated by measuring the concentration of leucocytes in venous blood leaving the arm. Neutrophil and monocyte leucocyte subpopulations are isolated by density gradient centrifugation techniques. Cell surface expression of CD11b and the intracellular production of hydrogen peroxide are measured via flow cytometry. Plasma concentrations of elastase and von Willebrand factor (vWF) are measured using enzyme-linked immunosorbemt assay (ELISA) techniques. During ischaemia-reperfusion, there was an increase in CD11b cell surface expression on neutrophils (P=0.040) and monocytes (P=0.049), and a decrease in peripheral blood leucocytes (P=0.019). There was an increase in the intracellular production of hydrogen peroxide by leucocyte subpopulations (P=0.027 [neutrophils], P=0.091 [monocytes]) and in the plasma elastase concentration (P=0.05). There was also a trend to increasing plasma concentration of vWF (P=0.0562), which was measured as a marker of endothelial damage. Ischaemia-reperfusion results in increased adhesiveness, entrapment and activation of leucocytes. Even following a mild ischaemic insult, this leucocyte response was followed immediately by evidence of endothelial damage. These results may have important implications for understanding the development of chronic diseases that involve mild ischaemic episodes.
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PMID:Role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury. 1720 Dec 5

Granulocyte colony-stimulating factor (G-CSF) is known to mobilize bone marrow stem cells into the peripheral circulation. This study was designed to investigate whether G-CSF by itself or in combination with hepatocyte growth factor (HGF) can promote vasculogenesis and angiogenesis in murine hind limb ischemia. Hind limb ischemia was induced in BALB/c nude or C57/BL6 mice that received bone marrow transplantation from green fluorescent protein (GFP)-transgenic mice. In the HGF group, hHGF expression plasmid was injected into the ischemic muscles. In the G-CSF group, G-CSF was administered subcutaneously for 10 days. The G-CSF+HGF group was concomitantly treated with G-CSF and HGF, and the control group received no treatment. All effects were confirmed at 4 weeks. The G-CSF+HGF group had a higher laser Doppler blood perfusion index, higher microvessel density, and a lower incidence of hind limb necrosis than the other groups. Confocal laser microscopy revealed that a number of GFP-positive cells infiltrated to the vasculature of the ischemic area. Some of the GFP positive cells were clearly co-immunostained with alpha-smooth muscle actin as well as von Willebrand factor. G-CSF-mobilized stem cells co-expressed CD49d and CD34, which would have promoted their adhesion to cells in the ischemic muscle that expressed HGF-induced vascular cell adhesion molecule-1. The combination of G-CSF and HGF had a significant synergistic effect, suggesting that the combination of mobilization of stem cells from bone marrow to peripheral circulation and their recruitment to the ischemic area might potentiate angiogenesis and vasculogenesis.
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PMID:G-CSF and HGF: combination of vasculogenesis and angiogenesis synergistically improves recovery in murine hind limb ischemia. 1722 29

Our previous study showed that CD151 promotes neovascularization and improves blood perfusion in a rat hindlimb ischemia model. In this study, we investigated whether CD151 promotes neovascularization and improves ventricular function after myocardial infarction in rats and the mechanisms involved. Rats were subjected to sham surgery or coronary artery ligation. We used rAAV for direct delivery of the human CD151 gene into the rat myocardium. At 4 weeks after coronary artery ligation, human CD151 mRNA was detected using RT-PCR. Measurement of capillary density was evaluated using immunostaining for von Willebrand factor, and hemodynamic variables and physiological parameters were monitored. Western blot analysis for CD151, PI3K, phosphor-Akt, total Akt, phosphor-eNOS, and total eNOS was performed. In addition, we also observed the effect of CD151 on the expression of VEGF using Western blot analysis. CD151 gene delivery could increase the expression of CD151 at gene and protein levels. Overexpression of CD151 could increase the number of microvessels in the ischemic myocardium and significantly improved the hemodynamic variables after myocardial infarction. In addition, CD151 could activate the PI3K pathway, including activation of Akt and eNOS, but did not affect the expression of VEGF. This study suggested that CD151 could promote neovascularization and improve ventricular function after myocardial infarction in rats. The mechanism may be that CD151 can activate the PI3K pathway and promote neovascularization via the PI3K pathway, without affecting ischemia-induced VEGF expression.
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PMID:CD151 gene delivery activates PI3K/Akt pathway and promotes neovascularization after myocardial infarction in rats. 1722 69


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