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)

The inhibition of Na(+)-H+ exchange (NHE) with amiloride analogues in vitro has been shown to prevent reperfusion arrhythmias and additional cell necrosis. Inhibition of intracellular Ca2+ overload via NHE inhibition has been suggested as a mechanism of these protective effects. The aim of this study was to examine whether treatment with amiloride analogues reduces the incidence of reperfusion arrhythmias and limits infarct size in vivo. Open-chest swine were exposed to a 30-minute left anterior descending artery (LAD) occlusion and 180 minutes of reperfusion during atrial pacing at 150 ppm. Intravenous 5-(N,N-dimethyl)-amiloride (AML, 5 micrograms/kg per min) was administered in the treatment group (n = 7) and intravenous saline in the control group (n = 7), starting 10 minutes before coronary occlusion. The infusion was continued during ischemia and reperfusion. The area at risk was defined by monastral blue dye and infarct size by triphenyltetrazolium chloride staining. Limb leads ECG and monophasic action potentials (MAPs) from the epicardium in the ischemic area were recorded. There was no significant difference in the size of the area at risk and hemodynamic parameters between the groups. However, the infarcted area was 0.4% +/- 1.0% of the area at risk in the treatment group, whereas it was 62% +/- 29% in the control group (P < 0.05). Pathological examination (Hematoxylin-eosin and Mallory's phosphotungstic acid-hematoxylin staining) revealed that all of the infarcted area consisted of contraction band necrosis. MAP duration in both groups was significantly shortened during ischemia. After reperfusion, MAP duration in the treatment group recovered earlier than that of control group. However, there was no significant difference in the incidence of ventricular tachyarrhythmia between the groups. Inhibition of NHE with AML prevented reperfusion related cell necrosis in the in vivo swine model, but did not reduce the incidence of ventricular tachyarrhythmia.
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PMID:Role of Na(+)-H+ exchange on reperfusion related myocardial injury and arrhythmias in an open-chest swine model. 894 91

Pentostatin (2prime prime or minute-deoxycoformycin, dCF) is a product of the fermentation of Streptomyces antibioticus. It is a tight-binding inhibitor of adenosine deaminase (ADA), an enzyme essential in cellular metabolism of purines. Children with congenital absence of ADA suffer from atrophy of lymphoid tissues and severe combined immune deficiency (SCID) syndrome. It was speculated that pentostatin would be lymphocytotoxic, and this proved to be the case, promoting its investigation in lymphoid neoplasms. It was anticipated that pentostatin would be most active in neoplasms with high intracellular concentrations of ADA---e.g., acute lymphocytic leukemia (ALL), particularly its T cell variety. Although pentostatin proved to be active in ALL, large doses were required and toxic effects outweighted therapeutic benefits. By contrast, pentostatin proved to be exceptionally active in hairy cell leukemia (HCL), a B cell neoplasm with low intracellular concentrations of ADA. Pentostatin has since been shown to possess activity in chronic lymphocytic leukemia, prolymphocytic leukemia, cutaneous T cell lymphomas, adult T cell lymphoma-leukemia, and low-grade non-Hodgkin's lymphomas. It potentiates the activity of vidarabine against viruses and against the cells of acute myeloid leukemia. Pentostatin is inactive in melanoma and renal carcinoma, but has not been adequately evaluated in other solid tumors. The toxic effects of pentostatin include renal failure, central nervous system (CNS) depression, immunosuppression, keratoconjunctivitis, and opportunistic infections. In the absence of pre-existing bone marrow compromise, pentostatin produces only mild myelosuppression. Aside from its use as an antineoplastic agent, pentostatin has potential applications as an immunosuppresive drug, as an antiviral agent, as an antimalarial compound, and in the protection of cells of the CNS from damage induced by ischemia and anoxia.
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PMID:Pentostatin (2prime prime or minute-Deoxycoformycin): Clinical Pharmacology, Role In Cancer Chemotherapy, and Future Prospects. 1184 52

Treatment of healthy donors with recombinant human granulocyte colony-stimulating factor (rhG-CSF) allows the mobilization and peripheralization into circulating blood of an adequate number of CD34+ cells that can then be collected by leukapheresis (PBSC). This procedure avoids the invasiveness of bone marrow harvest and the risks related to general anesthesia. The main adverse effects of rhG-CSF are: bone pain, 84%, headache, 54%, fatigue, 31%, and nausea, 13%, which are usually scored by the donors as moderate to severe, resolving within 2-3 days after discontinuation of the cytokine. Analgesics, mainly acetaminophen, are sufficient to control the pain. Less than 5% of the donors experience non-cardiac chest pain, a local reaction at the injection site, insomnia, dizziness or a low-grade fever. Discontinuation of the PBSC procedure because of adverse effects of rhG-CSF or leukapheresis is rarely necessary (0.5%) but this good tolerability can be hampered by the need, in 5-20% of cases, for an adequate venous access that requires insertion of a central or venous catheter. There are no absolute contraindications to the stimulation of healthy donors with rhG-CSF but the description of cases of non-traumatic splenic rupture, iritis, cardiac ischemia, and gouty arthritis suggests that further precautionary restrictions are advisable when deciding eligibility for PBSC collection. The main advantages for patients receiving an allogeneic PBSC transplant are the faster hematologic and immunologic recovery and the potential for a greater efficacy in advanced disease by lowering the transplant-related mortality. One of the major concerns regarding the use of rhG-CSF in unrelated healthy donors is the uncertainty about its possible role in triggering malignancy, in particular myelodysplastic syndrome and acute myeloid leukemia. There are no studies with an adequate sample size and follow-up that can answer this question but two recent retrospective studies reported that in the medium term rhG-CSF is not associated with an excess of lymphoproliferative disorders. Currently, caution on the long-term safety of the use of rhG-CSF in healthy donor is still warranted but the data so far accumulated on allogeneic PBSC transplants are encouraging both as far as concerns the good short-medium tolerability profile of G-CSF-stimulation of the donor and the potential major efficacy in leukemia patients.
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PMID:The use of cytokine-stimulated healthy donors in allogeneic stem cell transplantation. 1241 88

Pentostatin (2'-deoxycoformycin, dCF) is a purine nucleoside analog and a product of the fermentation of Streptomyces antibioticus. It is a tight-binding inhibitor of adenosine deaminase (ADA), an enzyme essential in the cellular metabolism of purines. Children with congenital absence of ADA suffer from atrophy of lymphoid tissues and severe combined immune deficiency (SCID) syndrome. It was hypothesized that pentostatin would be lymphocytotoxic and this proved to be true; this finding prompted its investigation in lymphoid neoplasms. It was anticipated that pentostatin would be most active in neoplasms with high intracellular concentrations of ADA, e.g. acute lymphocytic leukemia (ALL), particularly of the T-cell variety. Although pentostatin proved to be active in ALL, large doses were required and major toxic effects outweighed therapeutic benefits. By contrast, pentostatin proved to be exceptionally active in hairy cell leukemia (HCL), a B-cell neoplasm with low intracellular concentrations of ADA. Pentostatin has since been shown to possess activity in chronic lymphocytic leukemia, prolymphocytic leukemia, cutaneous T-cell lymphomas, adult T-cell lymphoma-leukemia, and low grade non-Hodgkin's lymphomas. It potentiates the activity of vidarabine against viruses and against the cells of acute myeloid leukemia. Pentostatin is inactive in melanoma and renal carcinoma, but has not been adequately evaluated in other solid tumors. The toxic effects of pentostatin include renal failure, central nervous system (CNS) depression, immunosuppresion, keratoconjunctivitis, and opportunistic infections. In the absence of pre-existing bone marrow compromise, pentostatin produces only mild myelosuppression. Aside from its use as an antineoplastic agent, pentostatin has potential applications as an immunosuppressive drug, as an antiviral agent, as an antimalarial compound, and in the protection of cells of the CNS from damage induced by ischemia and anoxia. Clinical studies with pentostatin are ongoing, and its roles in the management of neoplastic and non-neoplastic diseases have yet to be fully defined.
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PMID:Deoxycoformycin (pentostatin): clinical pharmacology, role in the chemotherapy of cancer, and use in other diseases. 1465 Dec 24

Leukapheresis is often considered in the management of acute myelogenous leukemia (AML) with hyperleukocytosis and its sequelae, including myocardial infarction, pulmonary complications, and stroke. It is utilized on the assumption that leukapheresis improves blood rheology. We present a woman with AML and a history of meningioma encasing her left internal carotid artery. She presented with hyperleukocytosis and symptoms of ischemia. As her white blood cell continued to rise despite initiation of hydroxyurea therapy, she underwent leukapheresis emergently. Transcranial Doppler ultrasound demonstrated increased flow velocities in the left internal carotid and the right middle cerebral arteries, which normalized after leukapheresis. This is the first documentation that leukapheresis, in combination with hydroxyurea, improves cerebral hemodynamics in a patient with AML.
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PMID:Increased cerebral blood flow after leukapheresis for acute myelogenous leukemia. 1765 77

Although coagulatory system disorders are well recognized in patients with acute leukemia, these usually present with either hemorrhagic complications or thrombosis of small vessels. Large vessel thrombosis is a very rare clinical presentation. We present a patient with previously undiagnosed acute myeloid leukemia (M5), who was referred to our hospital with symptoms of acute ischemia of his right lower limb. Occlusion of the right external iliac artery due to a combination of leucostasis and coagulation disorders was noted and successfully treated with urgent leukapheresis, immediate chemotherapy and surgical thromboembolectomy.
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PMID:Acute lower limb ischemia as the initial symptom of acute myeloid leukemia. 1784 76

Hepatic ischemia-reperfusion (I/R) injury occurs in a variety of clinical settings and generates the release of endogenous noninfectious ligands called damage-associated molecular pattern (DAMP) signal molecules from damaged cells. This study investigates the effect of DAMP molecules released by Kupffer cells (KC) in I/R injury on the expression of liver manganese superoxide dismutase (MnSOD), a key mitochondrial antioxidant enzyme. We show that MnSOD expression levels are increased in rats and remain high for 24 h after 30 min of ischemia. KC were damaged and depleted after I/R, in association with MnSOD upregulation. Causality was established by treatment with gadolinium chloride, known to selectively destroy KC, which also increased MnSOD levels. Recovery from the early damage (6 h) to the liver tissue was evidenced after 24 h. A physiological protective role for MnSOD was also confirmed by the increased susceptibility of MnSOD-knockdown AML-12 hepatocyte cells to I/R-induced cell death. Inhibition of DAMP molecule high-mobility group box-1 activity by injection of neutralizing antibody partially abolished the increase in liver MnSOD after I/R. Direct injection of ATP, to animals or cells, stimulated MnSOD upregulation. Another DAMP molecule, monosodium urate, also induced MnSOD expression in hepatocyte AML-12 and FaO cell cultures. In conclusion, a connection between danger signals and upregulation of the antioxidant defense system is shown here for the first time in the context of I/R liver injury.
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PMID:Antioxidant defense in hepatic ischemia-reperfusion injury is regulated by damage-associated molecular pattern signal molecules. 1867 99

Large vessel thrombosis is a very rare clinical presentation of acute leukemia which is usually revealed by hemorrhagic complications or thrombosis of small vessels. We present here the case of a patient with previously undiagnosed acute myeloid leukemia who was referred to our hospital with symptoms of acute ischemia of the left lower limb. Occlusion of the left popliteal artery due to a leucostasis was noted and successfully treated with emergency surgical thromboembolectomy and chemotherapy.
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PMID:[Acute lower limb ischemia revealing acute leukemia. Case report and review of the literature]. 1996 59

Real-time monitoring of cellular and organ conditions improves our understanding of various physiopathological phenomena. Such monitoring is expected to provide important alternatives for clinical diagnosis and therapy. We have sought to show physiopathological changes of organs as well as cells. Here, we present an example of in vivo imaging of liver states using the luciferase-based caspase-3 optical probe. We examined dynamic changes of apoptosis (caspase-3 activity) of a mouse liver as well as those of liver cells, proving that the emitted signals reflected the biochemically evaluated apoptotic cell death. In live liver cell (AML 12) experiments, the optical probe for caspase-3 activity emitted signals in response to Fas-ligand, staurosporine and hypoxia/reoxygenation, demonstrating that the probe can measure cellular apoptosis quantitatively. We therefore applied this probe for mouse liver ischemia/reperfusion (I/R) and drug-toxicity to liver. By expressing the probe in a mouse liver adenovirally, we imaged liver caspase-3 activity (i.e. apoptotic damage) non-invasively and chronologically in the hepatic I/R model of mice. The duration of liver ischemia affected the post-ischemic caspase-dependent damage. Ischemia (up to 60 min) enhanced liver damage after reperfusion, but prolonged ischemia (90 min of ischemia) induced not apoptotic cell death but necrotic cell death. Direct observations of the changes of organ conditions elucidated the dynamism of organ function and damage. These technologies clearly possess clinical relevance. They are expected to provide a new diagnostic tool for various clinical settings in the future.
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PMID:In vivo monitoring of liver damage using caspase-3 probe. 2237 59

Hepatic ischemia-reperfusion (IR) results in progressive injury; initiated by oxidative stress during ischemia and compounded by cytokine-mediated inflammation during reperfusion. Recovery requires strict regulation of these events. Recombinant human erythropoietin (rhEPO) is thought to mitigate hepatocellular IR injury by altering the nonparenchymal liver microenvironment. This study sought to identify additional mechanisms whereby rhEPO is protective after liver IR injury. Mice were treated with rhEPO (4 units/g s.c.) at the onset of partial liver ischemia and assessed for transaminase and histologic injury at intervals after reperfusion. Induction of cytokines, activation of signal transducers and activators of transcription (STATs), suppressors of cytokine signaling (Socs1, Socs3, Cis), caspase-3 activation, and heme oxygenase-1 (HO-1) expression were assessed in postischemic liver. Effects of rhEPO stimulation were further characterized in whole-liver lysates from mice undergoing rhEPO injection alone and in cultured AML-12 hepatocytes. Recombinant human erythropoietin treatment at the onset of severe (90 min) hepatic IR confirmed commensurate biochemical and histological protection without affecting tissue cytokine levels. Although Socs3 and STAT5 activation were induced in normal liver after in vivo rhEPO injection, this treatment did not augment expression beyond that seen with IR alone, and neither was induced in cultured hepatocytes treated with rhEPO. Recombinant human erythropoietin inhibited caspase-3 activation in nonparenchymal cells, whereas hepatocellular HO-1 was rapidly induced both in vivo and in vitro with rhEPO treatment. These data suggest HO-1 as a potent mechanism of rhEPO-mediated protection after liver IR, which involves both direct hepatocellular and nonparenchymal mechanisms.
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PMID:Hepatocellular heme oxygenase-1: a potential mechanism of erythropoietin-mediated protection after liver ischemia-reperfusion injury. 2500 66


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