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)

Prognosis of asymptomatic myocardial ischemia is largely unknown and the opportunity is still controversial of seeking for patients with silent ischemia. Aim of the present study is to evaluate the prognosis of painless myocardial ischemia documented by exercise test and myocardial scintigraphy. From June 1981 through November 1986, 206 patients without angina, history or ECG signs of old myocardial infarction, presenting a positive (decreases ST greater than or equal to 1.5 mm) exercise treadmill test, underwent exercise Thallium 201 myocardial imaging. Myocardial scintigraphy showed a normal scan in 85 cases and a reversible or fixed perfusion defect in 121. Patients with abnormal scan presenting ischemia at a low to moderate ergometric work-load were treated with betablockers or calcium-antagonist drugs. Out of patients with positive myocardial scintigraphy a sample of the first 100 consecutive subjects was considered. They were 87 men and 13 women aged 28-72 years (mean 54.8) observed during a mean follow up period of 33.1 +/- 1.6 months. Seven patients underwent coronary angiography which showed 3-vessel critical stenosis in 3 cases, 3-vessel lesions plus critical stenosis of the left main coronary-artery in 1 and 2-vessel lesions in 3. Two patients underwent coronary artery bypass surgery. A non fatal myocardial infarction occurred in 1 and 1 became symptomatic for angina, 11 and 20 months respectively after the diagnosis of ischemia. Three patients with ischemia at a low work-load and extensive scintigraphic perfusion defects died of sudden death and one of cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Prognosis of silent myocardial ischemia: follow-up of 100 patients with positive treadmill test and exertion myocardial scintigraphy]. 344 64

Necrotizing dermatitis in patients being treated with cancer chemotherapeutic agents can be of several types. Microbial causes can include a variety of bacteria and fungi, the most common being Pseudomonas aeruginosa. Gangrene from occlusive causes is not uncommon among cancer patients with coexisting atheromatous, thromboembolic, or obliterative vascular disease. Toxic gangrene is most commonly caused by extravasation of intravenously administered cytotoxic antineoplastic drugs but has also been associated with the use of coumarin congeners and the bite of the brown recluse spider. Pyoderma gangrenosum is an idiopathic condition that has been reported in association with myeloproliferative disorders. Finally, necrosis can be caused by the neoplasm itself, when its growth is so great that blood vessels are compressed and ischemia of the surrounding tissue results.
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PMID:Necrotizing dermatitis in patients receiving cancer chemotherapy. 346 38

Cerebral cortical sclerosis is an acquired condition that has rarely been described in cancer patients. We reviewed necropsy findings in all children with cancer who died at the Children's Hospital of Philadelphia during the 20 year period 1963-1982 and found cerebellar sclerosis in 14 children with cancer (12 with acute lymphoblastic leukemia, 1 each with neuroblastoma and osteogenic sarcoma). The lesions were focal (3), multifocal (9) or diffuse (2). They occurred more frequently in children with acute lymphoblastic leukemia who had received intravenous methotrexate therapy. Ten of these 12 children had also received whole brain irradiation. The pathogenesis of the cerebellar sclerosis is unknown, but it is possible that extrinsic cerebellar compression by tumor or chronically increased intracranial pressure may have played a role in 6, ischemia/hypoxia in 3, and methotrexate toxicity in 2. No clear associations could be ascertained in 3. Methotrexate may be a previously unrecognized cause of cerebellar cortical injury. In addition, oncologic treatment regimens that include other central nervous system-penetrating drugs and irradiation may sensitize cerebellar cortex and make it more susceptible to other cerebellar sclerosis-causative factors.
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PMID:Cerebellar sclerosis in pediatric cancer patients. 347 68

A high-pressure liquid chromatographic method was developed which achieved a separation and quantitation of 20 biologically important nucleosides and bases. The concentrations of pyrimidine nucleosides and bases, namely deoxycytidine, cytosine, cytidine, uracil, and uridine (22.6, 10.1, 5.2, 2.9, and 2.4 nmol/ml, respectively) were high in plasma, whereas purine nucleosides and bases were present in concentrations less than 2.5 nmol/ml. In erythrocytes, the pools of xanthine, hypoxanthine, and xanthosine were 32-, 27-, and 22-fold larger, respectively, whereas cytidine, uridine, and deoxycytidine were only 21, 12, and 5% of plasma concentrations. The results suggest a compartmental system for transport of some of the purine and pyrimidine nucleosides and bases in the whole blood. Studies on the effect of ischemia on nucleoside and base pools in rat liver indicated marked increases within 30 s in the concentrations of adenine, adenosine, inosine, hypoxanthine, uridine, and xanthine, whereas in hepatoma the effects were less pronounced. By 2 and 5 min ischemia these perturbations were most marked in both liver and hepatoma. These results indicate a need for rapid freeze-clamp preparation of tissue samples to obtain precise and repeatable results in the determination of tissue nucleoside and nucleobase concentrations.
Cancer Res 1987 Jun 15
PMID:Effect of ischemia on nucleosides and bases in rat liver and hepatoma 3924A. 358 Oct 61

The association of malignancy with thrombotic disorders of the arterial and venous systems is well described. To date, however, there are only 23 published case reports of digital gangrene associated with malignancy. During a prospective evaluation of over 700 patients with finger ischemia, there were five patients with finger gangrene associated with malignancy. Detailed clinical and laboratory evaluation, including detailed immunologic survey and hand angiography, allowed establishment of the precise mechanisms responsible for vascular occlusions in each patient. Three mechanisms were identified: arteritis, hyperviscosity, and hypercoagulability. Digital gangrene associated with malignancy is a rare condition, the mechanism for which can be deduced by careful diagnostic evaluation.
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PMID:Digital ischemia as a manifestation of malignancy. 360 32

This paper discussed the significance of the activities of purine and pyrimidine salvage enzymes in cancer cells and the targeting against them of chemotherapy. 1. The activities of salvage enzymes in the rat liver were orders of magnitude higher than those of the rate-limiting enzymes of de novo biosynthesis. A similar relationship was observed in rat hepatomas of different growth rates and in primary colon carcinoma in human. 2. The concentrations of nucleosides and nucleobases were measured in plasma, liver and hepatoma 3924A in the rat. The freeze-clamp method was required to determine the concentrations of these precursors in rat liver and hepatoma in a reliable and precise fashion because ischemia markedly altered the concentrations of nucleosides, nucleobases and, as shown earlier, nucleotides in these tissues. The results indicated that the liver markedly concentrated the purine precursors, hypoxanthine, guanine and adenine, but not thymidine, which was one-third that of the plasma. Uridine and deoxycytidine occurred in the same concentration as in plasma, but cytidine was 3-fold higher in liver. In the hepatoma in comparison to the liver the concentrations of the nucleosides and bases were altered and for some of the changes the enzymic differences between liver and hepatoma appeared to be accountable. 3. Kinetic parameters for purine and pyrimidine synthetic enzymes and for the substrates and co-factors were determined in liver and hepatoma 3924A. When enzymic activities were calculated at the tissue steady-state concentrations of the various ligands, the activities of the salvage enzymes were markedly higher than those of the rate-limiting enzymes. 4. Hepatoma cells were highly sensitive to the action of the transport inhibitor, dipyridamole, in lag and log phases. However, plateau phase cells lost their sensitivity to dipyridamole. 5. Amphotericin B rendered plateau phase cells sensitive to the inhibitory action of dipyridamole for the incorporation of thymidine. 6. Amphotericin B enhanced cytotoxicity of dipyridamole in hepatoma and human colon cancer HT-29 cells. 7. In these studies we discovered the decreased responsiveness to dipyridamole of plateau phase cells and the ability of amphotericin B to restore the sensitivity. Moreover, dipyridamole and amphotericin B were synergistic in their cytotoxic action in rat hepatoma cells and human colon cancer cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Salvage pathways as targets of chemotherapy. 367 9

Bowel ischemia and infarction are diseases primarily of, but not confined to, the elderly. Insidiously developing bowel ischemia may mimic more common gastrointestinal disturbances, such as peptic ulcer disease or malignancy, and go undiagnosed for long periods. Bowel infarction is a catastrophic event: Mortality rates approach 90%. Chronic intestinal ischemia may precede infarction, or infarction may occur with no warning. Laboratory and radiologic studies have minimal value in diagnosis of these disorders. A high index of suspicion must be maintained in patients complaining of abdominal pain if these diagnoses are to be made promptly.
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PMID:Bowel ischemia and infarction. Chronic and acute causes of abdominal pain. 368 21

The effect of hematoporphyrin derivative photoradiation on tumor and normal tissue microcirculation was studied microscopically in vivo on rats with mammary carcinomas transplanted into subcutis in transparent observation chambers. One day after i.p. injection of hematoporphyrin derivative (15 mg/kg), chambers were exposed to red light (632 +/- 2 nm, eight light dose values, 0 to 270 J/cm2). After an initial blanching (ischemia) of the tumor accompanied by apparent vasoconstriction, reperfusion was observed with a slowing down of the tumor circulation, vasodilatation, and eventually a complete stasis, together with diffuse hemorrhages and subsequent necrosis. Besides, in large normal tissue vessels, platelet aggregates were observed, but no hemorrhage. Tumor regrowth occurred unless the tumor circulation and the adjacent normal tissue circulation were both destroyed. Tumor cell viability after treatment was assessed by transplanting the tumor from the chamber into the flank of the same animal. Even after a combined porphyrin and light dose 4 times the lethal dose for all tissues in the chamber, five of five transplanted tumors did regrow. This leads to the conclusion that, in our model system, tumor cell death after photoradiation occurs secondary to destruction of the microcirculation. In order to obtain additional information on normal tissue damage, rat ears were also irradiated. For the same light dose, the biological effect was only slightly larger than that of the normal tissue in the observation chambers, even though the measured ratio of porphyrin concentrations in ears and normal tissue in the chambers (subcutis) was about six.
Cancer Res 1986 May
PMID:Destruction of rat mammary tumor and normal tissue microcirculation by hematoporphyrin derivative photoradiation observed in vivo in sandwich observation chambers. 369 92

The liver of Syrian hamsters was studied after exposure to dimethylnitrosamine (DMN) in drinking water for, respectively, 8, 12 and 16 weeks. One additional group of animals was offered DMN for 8 weeks, but maintained for further 8 weeks after removal of the compound. The changes consisted of a narrowing portal venopathy, probably arising, initially, from toxic pylephlebitis, being followed by widespread subendothelial prolapse of hepatocytes encroaching upon the lumen of terminal hepatic veins, which generally were free of inflammatory fibrosing lesions. The venous lesions were unrelated to malignant processes in the biliary duct system, which occurred after 16 weeks. Dilatation of sinusoids and small venules was associated with the presence of prolapsed hepatocytes around their openings into involved larger veins. At the end of 12 and 16 weeks of continuous ingestion of DMN, but also where the agent was withdrawn already at 8 weeks, phlebectasis and transitional stages in the formation of teleangiactatic type of peliosis were demonstrated, probably resulting from progressively impeded blood flow due to partial occlusion by prolapsed hepatocytes in terminal veins. The mechanism enabling hepatocytes to penetrate the venous wall was not clarified. There was no indication of invasive malignancy. Hepatocyte prolapse appeared more likely to result from some unknown mechanism of benign infiltration, promoted by regenerative stimulation. This may have been initiated by mild persistent ischemia due to the demonstrated portal venopathy. No endothelial hyperplasia was seen at any stage of the experiments thus eliminating the probability of peliosis being a source of vascular neoplasia, which has previously been described following more prolonged exposure to DMN. Certain parallelisms of the experimental results with hepatic vascular lesions in man subjected to drug therapy are discussed.
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PMID:Venoocclusive disease of the liver and phlebectatic peliosis in the golden hamster exposed to dimethylnitrosamine. 373 74

Cardiac metastases are often clinically inapparent but have important prognostic significance. A total of 1046 consecutive autopsies performed between 1981 and 1983 were reviewed, and 210 patients with both premortem and autopsy diagnoses of cancer were found, in whom a recent (less than 3 months before death) ECG was available. Of these patients, 47 had cardiac metastases (group I) and 163 did not (group II). In group I, 19 patients had new ECG changes suggestive of myocardial ischemia or injury, including either diffuse T wave inversion (10%), segmental (ECG pattern suggestive of a specific coronary distribution) T wave inversion (80%), or ST elevation (10%). None of these patients had symptoms suggestive of myocardial ischemia. In group II, six patients had ECG changes suggestive of myocardial ischemia or injury: four patients with preterminal sepsis, one with myocardial infarction, and one with aspergillus nodules within the myocardium. New atrial arrhythmias (seven patients) and low voltage (10 patients) were found with greater frequency in group I patients (p less than 0.0005 and p less than 0.00001, respectively, vs group II). Patients with normal ECGs were unlikely to have cardiac metastases; however, the finding of nonspecific ST-T wave changes was not helpful in differentiating the two groups. In clinically stable patients with cancer and no cardiac symptoms suggestive of ischemia, any new ECG change should raise the suspicion of cardiac metastases. The ECG finding of myocardial ischemia or injury has high specificity (96%, p less than 0.000001) for cardiac metastases.
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PMID:Electrocardiographic markers of cardiac metastasis. 378 78


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