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)

Following liver transplantation, the decision to retransplant in cases in which graft function is marginal must be taken early. Plasma coagulation factor monitoring was evaluated as an early predictor of graft failure requiring retransplantation in the first posttransplant week. Plasma levels of fibrinogen, factors V, VII, VIII, IX, antithrombin III, protein C, and plasminogen were measured in all patients at 0, 12, 24, 48, 72, 96, and 120 hours posttransplant in 46 patients who received 56 grafts and results were compared between livers that failed early (group 1) and those that functioned adequately (group 2). Six grafts were included in group 1: one patient died before retransplantation, four were retransplanted once, and one patient was retransplanted twice. Three grafts had primary nonfunction (PNF), 2 had obstructed portal veins, and 1 had a long period of warm ischemia during the initial transplant. In group 1, plasma levels of factor V were significantly lower than in group 2 at 24, 48, and 72 hours posttransplant (21.2% +/- 14.2%, 12.4% +/- 4.5%, and 13.0% +/- 5.0% v 39.1% +/- 23.9%, 48.8% +/- 31.9%, and 60.9% +/- 25.9%; P less than .05, P less than .01, and P less than .005, respectively). Similarly, plasma levels of factor VII were significantly lower in group 1 over the same period of time (7.3% +/- 2.7%, 4.2% +/- 1.8%, and 4.7% +/- 2.5% v 27.4% +/- 17.1%, 34.1% +/- 21.6%, and 34.8% +/- 18.6%, respectively; P less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Coagulation plasma factor levels are early indicators of graft nonfunction following liver transplantation in children. 150 Oct 1

In 1983, a previously healthy 21-year old mother came to University Hospital in Dijon, France feeling weak and had a severe frontal headache with vomiting. Clinical and biochemical tests were normal. She smoked 20 cigarettes/day and used a high dosed combined oral contraceptive (OC) (ethinyl estradiol and cyproterone acetate). 15 days later, the headache returned and she could not understand spoken words and the bilateral section of the brain had slowed. Yet her mental status was normal as were cerebrospinal fluid and cerebral computerized tomography tests. The antiherpes virus drug, vidabarine, did not alleviate symptoms. At least 1 month later, a severe left pulmonary embolism caused acute right heart failure. She also had a prethrombotic left iliac vein, so physicians began heparin therapy, adding nifedipine and buflomedil to control the spasms in the right internal iliac artery and both external iliac arteries. Acute ischemia of the lower limbs eased within a week but sensory disorders remained for 2 months. Satisfactory collaterality transpired due to a blocked left external iliac artery and left iliac vein. The following signs and symptoms indicated her condition to be homocystinuria: blond hair with deep blue eyes, macrocytic anemia, factor VII deficit (51%), strong positive Brandt's reaction, cystine homocystine in the plasma, and presence of homocystine, cystathionine, and methionine in the urine. Physicians took her off the OC and discharged her on vitamin B6/day, folic acid/day, betaine citrate/day, and the anticoagulant Coumadin. A subsequent check of her 19-year old sister found she had it too. They assessed the patient's condition yearly. In 1988, her left leg developed edema and she limped when not using elastic stockings. Effects of iliac vein phlebitis were evident. She no longer suffered from headaches. Since plasma methionine was within the normal range and homocystine no longer was present in plasma and urine, the physicians halted the anticoagulant therapy. In conclusion, the OC precipitated this partial form of homocystinuria.
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PMID:Vascular manifestations in homocystinuria. 161 Jun 63

Increasing evidence has demonstrated the importance of monocyte procoagulant activity (PCA) in the pathogenesis of coagulopathies in a variety of diseases. Because endotoxin precipitated coagulopathies are common sequelae to intestinal ischemia/endotoxemia in the equine species, we investigated the ability of equine peripheral blood monocytes to express PCA. Monocytes isolated from five healthy adult horses were incubated in vitro with Escherichia coli endotoxin (10 micrograms), and the PCA was measured by the ability of cellular lysates to accelerate the clotting times of equine plasma in a modified one-stage recalcification assay. Equine monocyte PCA was identified as thromboplastin based on lack of clot formation in factor VII-deficient plasma. The induction of PCA occurred as early as 2 hr after endotoxin exposure, peaked at 6 hr (396% increase), and then gradually declined. The amount of PCA was proportional to the dose of endotoxin (0.01 to 100 micrograms) and the number of monocytes. Neither platelets nor neutrophils produced PCA, either in the absence or presence of endotoxin (1 microgram). Lymphocytes at a concentration of 4 x 10(6)/ml RPMI did produce a significant amount of PCA, compared to the time-matched controls. Co-incubation of neutrophils or lymphocytes with monocytes did not alter the PCA, whereas coincubation of platelets and monocytes significantly enhanced the expression of PCA. This effect was further augmented by the addition of endotoxin (1 microgram).
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PMID:Endotoxin-induced procoagulant activity in equine peripheral blood monocytes. 320 23

Tissue factor is a transmembrane protein that activates the extrinsic coagulation pathway by binding factor VII. Endothelial cells, being in contact with circulating blood, do not normally express tissue factor. Here we provide evidence that oxygen free radicals induce tissue factor messenger RNA transcription and expression of tissue factor procoagulant activity in endothelial cells in culture. Isolated, perfused rabbit hearts exposed to exogenous oxygen free radicals also showed a marked increase in tissue factor activity within the coronary circulation. Furthermore, in ex vivo and in vivo hearts subjected to ischemia and reperfusion, a condition associated with a production of oxygen free radicals in large amounts, a marked increase in tissue factor activity occurred. This phenomenon could be abolished by oxygen radical scavengers. This increase in tissue factor activity during postischemic reperfusion was accompanied by a significant decrease in coronary flow, suggesting that increase in tissue factor activity with the consequent activation of the coagulation cascade might impair coronary flow during reperfusion and possibly contribute to the occurrence of reperfusion injury.
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PMID:Effects of tissue factor induced by oxygen free radicals on coronary flow during reperfusion. 856 35

We performed a case-control study to investigate the role of recent infection as stroke risk factor and to identify pathogenetic pathways linking infection and stroke. We examined 166 consecutive patients with acute cerebrovascular ischemia and 166 patients hospitalized for nonvascular and noninflammatory neurologic diseases. Control subjects were individually matched to patients for sex, age, and season of admission. We assessed special biochemical parameters in subgroups of stroke patients with and without recent infection (n = 21) who were similar with respect to demographic and clinical parameters. Infection within the preceding week was a risk factor for cerebrovascular ischemia in univariate (odds ratio [OR] 3.1; 95% confidence interval (CI), 1.57 to 6.1) and age-adjusted multiple logistic regression analysis (OR 2.9; 95% CI, 1.31 to 6.4). The OR of recent infection and age were inversely related. Both bacterial and viral infection contributed to increased risk. Infection elevated the risk for cardioembolism and tended to increase the risk for arterioarterial embolism. Stroke patients with and without preceding infection were not different with respect to factor VII and factor VIII activity, fibrin monomer, fibrin D-dimer, von Willebrand factor, C4b-binding protein, protein S, anticardiolipin antibodies, interleukin-1 receptor antagonist, soluble tumor necrosis factor-alpha receptor, interleukin-6, interleukin-8, and neopterin. In conclusion, recent infection is an independent risk factor for acute cerebrovascular ischemia. Its role appears to be more important in younger age groups. The pathogenetic linkage between infection and stroke is still insufficiently understood.
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PMID:Recent bacterial and viral infection is a risk factor for cerebrovascular ischemia: clinical and biochemical studies. 944 80

In the 80's, three retrospective studies showed an inverse relation between fish consumption and ischemic heart disease (IHD) mortality. In parallel, fish fats containing the polyunsaturated fatty acid eicosapentaenoic (EPA) were shown to impair platelet aggregation and thromboxane formation. The results of the large prospective Diet and Reinfarction (DART) Study in the secondary prevention of myocardial infarction have further supported the possibility of potential interrelationships between diet and thrombogenic factors with respect to IHD. More recently these concepts have been confirmed and extended in the prospective Lyon Heart Study. However, in the latter in addition to changes in the content of EPA, changes in other well known variables (i.e. leukocytes and vitamin E) often abnormal in subjects prone to arterial thrombosis have been found. From studies on polygenic disorders, we have learned that by lowering the threshold and becoming a susceptibility gene, a polymorphism can lead to an effect assuming that it is present in the appropriate milieu. Nutrients have been shown to affect major determinants of myocardial ischemia such as fibrinogen or factor VII. However, the extent to what these and other hemostatic variables have been affected in studies devoted to dietary prevention of ischemia remains presently elusive.
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PMID:Nutrition and thrombogenic factors. 1071 34

Abnormal uterine bleeding is the major reason for discontinuing long-term progesterone-only contraceptives (LTPOCs). Prior studies demonstrated that endometria exposed to the LTPOC, Norplant, display aberrant angiogenesis, leukocyte infiltration, and hypoxia-associated impaired blood flow. Paradoxically, human endometrial stromal cells (HESCs) of these specimens exhibit elevated expression of tissue factor (TF), the primary initiator of hemostasis via thrombin generation. The current study demonstrates that TF levels are also elevated in HESCs that are decidualized after insertion of Mirena, an intrauterine system that releases levonorgestrel directly into the endometrial canal and produces elevated perivascular levels of the proinflammatory and angiognenic cytokine IL-8. Because bleeding, inflammation, and ischemia-associated increased vascular permeability enhance access of plasma factor VII to HESC-expressed TF to generate thrombin, we evaluated the effects of steroids, thrombin, and hypoxia on HESC expression of IL-8. Confluent HESCs were incubated in a serum-containing medium for 7 d with vehicle control or estradiol (E(2)) plus medroxyprogesterone acetate (MPA). The medium was then exchanged for corresponding defined medium with and without thrombin, and the cultures were incubated in parallel for up to 48 h in a standard incubator (normoxia) or a sealed chamber at 0-1% O(2) (hypoxia). Under normoxia, immunoreactive IL-8 levels in the conditioned medium were reduced to one-third of control levels during decidualization with E(2)+MPA (P < 0.05; n = 5). In E(2)+MPA-treated cultures, thrombin (0.1 U/ml to 2.5 U/m) elicited a dose-dependent reversal of this inhibition, elevating IL-8 up to 60-fold (P < 0.05; n = 5) for more than 24 h and steady-state IL-8 mRNA levels by 3-fold for 3 h. The specific inactivator, hirudin, blocked most of the effects of thrombin, whereas TRAP-14, an agonist of the protease-activated receptor for thrombin, enhanced IL-8 output. In the absence of thrombin, hypoxia elevated IL-8 output 5-fold in E(2)+MPA-treated HESCs (P < 0.02, n = 4), with thrombin exerting additive effects. In contrast to its effects in progestin-treated HESCs, hypoxia did not elevate IL-8 output in control cultures. This study suggests that inhibition of IL-8 expression in decidualized HESCs contributes to the antiinflammatory milieu of the luteal phase. However, LTPOC-induced hypoxia and excess thrombin generation enhance IL-8 expression in decidualized HESCs, thereby eliciting aberrant angiogenesis and inflammation that promote the onset of abnormal uterine bleeding.
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PMID:Effects of thrombin, hypoxia, and steroids on interleukin-8 expression in decidualized human endometrial stromal cells: implications for long-term progestin-only contraceptive-induced bleeding. 1500 49

Following vessel wall injury, tissue factor (TF) is exposed and forms complexes with already activated factor VII (FVIIa) present in the circulating blood, thereby initiating the hemostatic process. After the first FXa is formed, the TF pathway inhibitor (TFPI) forms a complex with FXa, and a quaternary complex is formed, TF/FVIIa/ FXa/TFPI, which inhibits the first step of the hemostatic pathway. Recombinant activated FVII (rFVIIa) has been developed for use as a hemostatic agent (NovoNordisk A/S, Denmark). Active site-inactivated rFVIIa (rFVIIai) has also been prepared and was shown to have a faster association to and a slower dissociation from TF than rFVIIa, resulting in a lower calculated Kd of rFVIIai compared with rFVIIa. In various animal models rFVIIai has been demonstrated to prevent or diminish immediate thrombus formation at the site of vessel wall injury (athroplasty or other forms of mechanical injury) as well as the development of long-term intima thickening. The inflammatory response following endotoxin-induced sepsis was shown to decrease after administration of rFVIIai. Also, survival increased in the rFVIIai-treated animals in this study. In addition, ischemia-reperfusion injury was mitigated by rFVIIai. In a limited number of patients undergoing percutaneous transluminal coronary angioplasty (PTCA), rFVIIai was observed to allow PTCA to be performed at lower doses of heparin than what has been reported previously.
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PMID:rFVIIai in Acute Coronary Syndromes. 1519 83

This discussion focuses on recent reports relevant to improved understanding and future directions in the management of intracerebral hemorrhage (ICH). Prevention is possible with adequate treatment of hypertension; microbleeds, apolipoprotein genotype, and cholesterol treatment have been examined in relation to ICH risk. Hematoma products, matrix metalloproteinases, inflammatory markers, and means to attenuate injury have also received attention. The multifaceted character of perihematomal edema has been further defined but evidence for perihematomal ischemia remains elusive. New data on acute blood pressure reinforces the need for a clinical trial. With the lack of efficacy found in the International Surgical Trial in Intracerebral Hemorrhage (ISTICH), a landmark surgical trial, emphasis is shifting to minimally invasive and catheter/thrombolytic-based technologies for clot evacuation. On the medical side, activated factor VII has been shown to control hemorrhage growth. Looking forward, stem cell therapies for ICH are under investigation and some outcome studies are shedding new rays of hope.
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PMID:New era for management of primary hypertensive intracerebral hemorrhage. 1567 5

One of the limitations to hepatocyte transplantation is the restricted availability of donor liver tissue. The aim of this study was to evaluate livers from non-heart-beating donors (NHBDs) as a source of hepatocytes for cell transplantation. A total of 20 livers/segments obtained from NHBD were perfused under good manufacturing practices using a standard collagenase digestion method. The donor liver median warm ischemia time was 15 minutes (range, 11-40 minutes), and cold ischemia time was 13 hours (range, 6-30 hours) prior to cell isolation. The cell viability of the hepatocytes obtained was 52% (1-81%), with a yield of 2.2 x 10(6)(0.2-29.7 x 10(6)) cells per gram of tissue. There was a significant negative correlation between hepatocyte viability and length of both warm ischemia (r = -0.544, P = 0.013) and cold ischemia (r = -0.510, P = 0.022). Preliminary experiments were performed on the viability testing of NHBD livers based on digestion of needle biopsies with collagenase and assessment of the hepatocytes produced. Two of the NHBD cell preparations, which had been cryopreserved, were used as part of a series of cell infusions for hepatocyte transplantation. A 3.5-yr-old girl with Crigler-Najjar syndrome type I received 9.7 x 10(8) NHBD hepatocytes (viability on thawing, 65%), and a 4-month-old boy with inherited clotting factor VII deficiency received 5.0 x 10(8) hepatocytes (viability, 57%). In conclusion, hepatocytes suitable for cell transplantation can be obtained from NHBD livers. Higher viability values may be obtained if both warm and cold ischemia times of donor liver can be reduced prior to processing.
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PMID:Isolation of hepatocytes from livers from non-heart-beating donors for cell transplantation. 1652 14


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