Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxygen consumption rates for mouse mastocytoma cells examined from 3 to 4 hours after x-irradiation with 250-2000 rads were consistently higher than controls. Cyclic fluctuations in oxygen consumption per cell were dose-dependent; peaks in consumption were generally greater in magnitude and occurred later in time with increasing dose. The cyclic response in consumption is probably due to cell synchronization effects, while the overall higher respiration rates of irradiated cells may reflect increased metabolic activity in response to radiation damage. Oxygen consumption rates for the total cell population were cyclic after 250 and 500 rads, but declined steadily after 1000 or 2000 rads; oxygen consumption rates tended to be lower than controls, especially 12-24 hours postirradiation. Differences between cellular and population oxygen consumption rates reflect changes in cell number after irradiation. It is suggested that postirradiation reoxygenation kinetics in solid tumors may result from changes in tumor oxygen demand.
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PMID:Tumor cell respiration following irradiation. 41 6

The cell cycle distribution of in vitro cultured Ehrlich ascites tumor (EAT) cells was analysed by pulse-cytophotometry to characterize the growth cessation observed under anaerobic conditions. DNA histograms provided evidence that in the absence of oxygen EAT cells accumulate in the G1 and early S phase of the cell cycle while in the presence of oxygen an increase in G2 was observed during 24h culture period. Cellular recovery from anaerobiosis was observed soon after transfer of the cells into fresh aerobic culture medium but occurred slowly if the cells were only resupplied with air. Cell cycle analyses as well as (14C)-thymidine incorporation suggest considerable synchronization results from the introduction of anaerobiosis.
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PMID:Anaerobiosis and oxygen recovery: changes in cell cycle distribution of Ehrlich ascites tumor cells grown in vitro. 41 94

The plasma membrane of the Ehrlich ascites tumor cell contains an NADH dehydrogenase. This activity was shown not to be due to contamination by other subcellular membranes. A variety of electron acceptors have been compared as to rate with the following result: ferricyanide greater than cytochrome c greater than cytochrome b5 greater than glyoxylate greater than dichlorophenolindophenol. Oxygen acceptance could not be detected. The optimum assay temperature and pH ranges were 30--40 degrees C and pH 6--8, respectively. With respect to either NADH or ferricyanide, the kinetics yielded linear double-reciprocal plots. Inhibition of the enzyme by sulfhydryl reagents could be blocked by excess NADH. Detergents such as Triton X-100 or cholate resulted in solubilization of the enzymatic activity, but phospholipase A2 did not. The activity differed from that of the mitochondria in that it was not inhibited by rotenone or antimycin A. The possible involvement of NADH oxidation in the energetics of plasma membrane transport is discussed.
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PMID:Electron-transferring enzymes in the plasma membrane of the Ehrlich ascites tumor cell. 42 30

Eighty-nine breast cancer patients were studied for the end result of therapy. During surgery, the anaesthesia administered was either halothane (61 cases) or ether (28 cases) mixture with nitrogen and oxygen. The holstead method for mastectomy was used for all cases. The results showed that the type of anaesthesia influenced the end results of therapy of breast cancer patients. The survival rates of patients receiving halothane were much higher than those of ether anaesthetized cases. The differences were most pronounced among cases who received both preoperative radiotherapy and postoperative chemotherapy, and in cases with metastasis into regional lymph node. A comparison of groups of patients on the basis of such parameters as the anaesthetic used, age and degree of tumor progression (according to TNM classification and post-operative histological assays) showed them to well matched. These results may be explained by the effects of the anaesthesia on the role of immunity in controlling tumor cell implantation and growth of metastasis.
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PMID:Survival rates of breast carcinoma patients after surgery and anaesthetic. 45 20

Perfluorinated hydrocarbon compounds (PFHC) possess unique physical properties suggesting possible usefulness in man. Their low surface tension allows free flow into tiny folds and crevices, facilitating dispersion along peritoneal surfaces affected by a tumor. These substances are also oxygen solvents. BDF1 female mice injected intraperitoneally (IP) with 10(6) P388 mouse leukemia cells were studied following treatment with preoxygenated compound 1913 and increasing doses of radiation. Preliminary results suggest increased life span compared to radiation treatment alone. Radioenhancement at high sublethal doses of whole-body radiation cannot be excluded.
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PMID:Treatment of P388 leukemia in vivo with perfluoroctylbromide and radiation: a preliminary study. 47 98

A 22-year-old black male presented with erythrocytosis and proteinuria. The erythrocytosis was characterized by increased red cell mass, normal arterial oxygen saturation, and normal hemoglobin electrophoresis and oxygen affinity. There was no splenomegaly, and the white blood cell count, platelet count, serum uric acid concentration, serum B12 levels and leukocyte alkaline phosphatase activity were normal. Tumors of the liver, lung, kidney and cerebellum, which have been associated with erythrocytosis, were not found. The only associated disease was biopsy proven focal glomerulosclerosis. Renal vein thrombosis was excluded by renal venography and arteriography. This case illustrates the rarely reported association of the nephrotic syndrome and erythrocytosis. Other nephrogenic causes of erythrocytosis are mentioned, including renal cysts, tumors, renal artery stenosis and transplantation. The role of the kidney in erythropoietin production and possible mechanisms of nephrogenic erythrocytosis are discussed.
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PMID:Focal glomerulosclerosis and erythrocytosis. 50 18

Anaerobic culture conditions (95% argon/5% CO2) caused a slightly greater increase in total lipids of Ehrlich ascites tumor cells than a gas phase of 20% O2, 75% N2, 5% CO2. Whereas the rate of [U-14C]acetate incorporation into total lipids and lipid-subclasses rose markedly in the absence of oxygen, a drastic decrease of [U-14C]pyruvate and [1-14C]octanoate incorporation as well as a 30% reduction of 3H incorporation into lipids from tritiated water were observed under these conditions. Since profound changes in the metabolic state of cells cause alterations in the specific activity of the acetyl-CoA pool but do not alter the specific activity of intracellular water, this precursor is considered to be an adequate monitor for lipogenesis under aerobic and anaerobic culture conditions. Therefore, it is concluded that Ehrlich ascites tumor cells are not able to reoxidize NADH/NADPH in the absence of oxygen by a stimulation of biosynthesis of fatty acids as is discussed to be the case in normal cells. The slight increase in total lipids of anaerobically cultured cells seems to be the result of an imbalance between normal uptake and impaired utilization of lipids from serum-supplemented culture medium.
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PMID:Lipogenesis in Ehrlich ascites tumor cells under anaerobic culture conditions. 52 49

Comparative studies were done on the actions of hydrophobic drugs (cepharanthine, papaverine and cholesterol) regarding chemical modifications of Ehrlich ascites tumor cell membranes. Changes in membrane potential monitored by using cyanine dye (diS-C3-(5)) were induced by cepharanthine and papaverine, but not by cholesterol. Increase in membrane permeability of K+ ions induced with lysolecithin was strongly inhibited in the order of papaverine, cholesterol and cepharanthine. Oxygen uptake by the cells was also strongly inhibited by papaverine, but the inhibitory effect by cepharanthine was little and cholesterol had no effect. Membrane fluidity was decreased in the order of cholesterol, cepharanthine and papaverine. From these results, it was suggested that papaverine maintained the compartmentation of K+ ion and membrane fluidity by regulating the intracellular mitochondrial metabolism or by inhibiting the membrane bound ATPase nucleotidase activity. The membrane stabilizing effect of cepharanthine and cholesterol probably was due to decrease in the membrane fluidity because of the hydrophobic association to the lipid bilayer of the cell membranes.
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PMID:[Comparative studies on the chemical modifications of Ehrlich ascites tumor cell membranes by hydrophobic drugs (cepharanthine, papaverine and cholesterol) (author's transl)]. 53 24

Decreasing the oxygen in the respiration-air of animals to 11-12%, it was possible to increase the oncolysis-effect of the Clostridial-Strain M55 significant (macroscopical complete oncolysis in comparison with the usual application: Ehrlich-Solid-Tumour +62%, Harding-Passey-Melanom +64%). In nearly 30%, Tumours cured completely.
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PMID:[Experiments to improve the oncolysis-effect of clostridial-strain M55 (author's transl)]. 54 54

(1) Oxygen uptake and lactate production of different strains of ascites tumor cells were assayed after exposure to an extracellular photochemical system known to produce reactive oxygen derivatives. The various cells tested showed differential sensitivity to the treatment, ranging from nearly full inactivation of Ehrlich cells to nearly full resistance of Yoshida cells. (2) Glucose plus succinate added after the treatment reestablished basal oxygen uptake capacity suggesting that the cell membrane was the primary site of damage. This was confirmed by dye-permeabilization and protein leakage in sensitive cells. (3) H2O2 was shown to be the only relevant oxygen derivative in the production of cell damage: catalase was the only externally added agent that protected sensitive cells, and H2O2 (congruent to 10(-3) M) had the same effects as the photochemical treatment. (4) While the absence of catalase is a feature common to all tumors tested, sensitivity to H2O2 appears to be related to cellular levels of glutathione peroxidase and of its subsidiary enzymes glucose-6-phosphate dehydrogenase, glutathione reductase and glutathione synthetase.
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PMID:Differential sensitivity of tumor cells to externally generated hydrogen peroxide. Role of glutathione and related enzymes. 55 3


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