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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Certain bioflavonoids inhibit the glycolysis of variety of tumor cells by interfering with the generation of adenosine diphosphate and inorganic phosphate which are required for glycolysis. Tetra- and pentahydroxy flavones with hydroxyl groups as 3, 3', 4', 5, and 7 (e.g., quercetin) are the most active. They inhibit the activity of isolated Na+-K+-adenosinetriphosphatase of the plasma membrane and of mitochondrial adenosinetriphosphatase, but under appropriate conditions do not interfere with the ion transport increase the the translocation efficiency of the ion pump. It was shown that in several tumor cells loosely coupled ion pumps are responsible for the high rate of aerobic glycolysis, the effect of quercetin on the growth of several cell lines was examined. Since bicarbonate and serum albumin were found to counteract the effect of quercetin, the cells were grown in tissue cultures at low concentrations of these compounds. Pronounced inhibition of growth was observed at 5 to 20 mug of quercetin per ml of growth medium.
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PMID:The effect of flavonoids on aerobic glycolysis and growth of tumor cells. 12 7

A new procedure for the fractionation of mucopolysaccharides based upon differences in their partition behavior in aqueous polymer two-phase systems has been devised. Systems containing dextran, poly(ethylene glycol), trimethylamino-poly(ethylene glycol), potassium bromide and sodium phosphate buffer were employed. Countercurrent distributions were performed with a miniature countercurrent distribution device designed especially for use with aqueous polymer two-phase systems. An advantage over the widely used procedures involving precipitation of mucopolysaccharides as their quaternary ammonium detergent complexes is that the countercurrent distribution pattern of a particular mucopolysaccharide is not affected by the simultaneous presence of other mucopolysaccharides. Preliminary distributions of labelled mucopolysaccharides isolated from the cells and culture medium of monolayer cultures of rat tumor cells demonstrate that the procedure is particularly well suited for the fractionation of very minute quantities of mucopolysaccharides.
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PMID:Fractionation of mucopolysaccharides by countercurrent distribution in aqueous polymer two-phase systems. 12 1

Treatment of ascites tumor cells with dextran sulfate resulted in a marked inhibition of the incorporation of [14C]valine into protein in the presence of a high Na+ medium. Amino acid incorporation was restored after i.p. injection of these cells into mice or by exposure of the cells to ascites fluid in vitro. In a medium high in K+ and low in Na+, [14C]valine incorporation into protein took place in dextran treated cells. Rotenone inhibited the reaction, which could be restored by addition of both inorganic phosphate and either glucose or glucose 6-phosphate. Quercetin, an inhibitor of the Na+-K+-ATPase, markedly depressed the incorporation of [14C]valine into protein in intact sdviyrd tumor cells in a high Na+ medium. There was little or no inhibition of protein synthesis in dextran sulfate treated cells when tested in a high K+-low Na+ medium. These experiments suggest a relationship between protein synthesis and the operation of the membranous Na+-K+-ATPase.
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PMID:Protein synthesis in dextran sulfate-treated ascites tumor cells. 13 42

Hypercalcemia calls first for supportive measures, eg, adequate hydration, movement or mobilization of the patient to the greatest amount tolerated, and reevaluation of drugs being taken. When immediate lowering of the serum calcium level is not clinically mandatory, oral administration of furosemide, corticosteroid, or phosphorus should be considered. In acute emergencies, saline loading and parenteral furosemide therapy should be tried first, except in a patient with renal failure and congestive heart failure, in whom peritoneal dialysis or hemodialysis should be used instead. Calcitonin can be given for the first 12 to 24 hours to lower serum calcium concentration until a definitive management plan is formulated. Corticosteroid, if not contraindicated, should be started as soon as possible. In severe primary hyperparathyroidism with hypophosphatemia, phosphorus can be given intravenously until oral phosphate therapy can be established. Surgery, of course, should be performed as soon as possible. In most cases of neoplasia, mithramycin given according to a recommended schedule is safe and frequently effective. In desperate cases, additional use of prostaglandin synthesis inhibitors probably now is justified by empirical observations. All of these therapeutic measures are used only to stabilize electrolyte balance so that the primary cause of the hypercalcemia can be treated.
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PMID:Management of hypercalcemia. 15 84

Mitochondria from a rat mammary tumor (R3230AC) have been compared with mitochondria from pregnant and lactating rat mammary glands, with particular attention paid to inner membrane enzymes and Transport proteins. In the tumor the mitochondrial adenosine triphosphatase was not activated by 2,4-dinitrophenol, in contrast to the mammary mitochondria from lactating or pregnant rats. Translocation of adenosine diphosphate across the inner membrane was found to be more rapid in the tumor by virtue of lovered Km adenosine diphosphate and raised Vmax. Transport of phosphate and dicarboxylic acids occurred at similar rates in all three types of mitochondria. The inner membrane proteins were also examined directly by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and some differences are noted. These results, although they indicate subtle differences between the inner mitochondrial membranes of tumor as compared with those of pregnant or lactating rat mammary glands, cannot form the basis of an explanation for enhanced glucose utilization and aerobic lactic acid production in this tumor.
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PMID:A comparative study of inner membrane enzymes and transport systems in mitochondria from R3230AC mammary tumor and normal rat mammary gland. 16 45

The capacity to effectively label tumor cell hostones using very short pulses of [3-H]acetate and [32-P]phosphate (1 to 10 min) has been developed. Four histone fractions F3, F2a1, F2a2, and F2b are extensively acetylated in short time periods. About 70% of the acetate accumulated on the histone during a short pulse is removed with a half-life of similar to 3 min. The rest of the metabolically active acetate is removed with a half-life of 30 to 40 min. Histones F2a1, F2a2, and F1 are acetylated at the NH2 terminus and this modification is metabolically stable. In short pulses, histones are labeled with 32-P in the order F2a2 greater than F1 greater than F3 greater than F2a1 greater than F2b. All fractions have a fairly rapid turnover time (t1/2 similar 20 to 40 min) except F1 phosphate which turns over some 5 times more slowly.
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PMID:Studies on highly metabolically active acetylation and phosphorylation of histones. 16 94

A small number of differentiated tumor cells could be found besides a great number of undifferentiated ones. Abnormal dense granules were found in the nuclei of undifferentiated tumor cells, not in differentiated ones. Non-specific filaments were seen in the cytoplasm of undifferentiated tumor cells. Differentiated tumor cells demonstrated various stages of myofibrillar structures such as A, I, and Z bands, many glycogen granules, mitochondria and a basement membrane. Polyglucose particles synthesized from glycose-1-phosphate by phosphorylase activity were located in the cytoplasmic matrix of undifferentiated and differentiated tumor cells and in the karyolymph of undifferentiated tumor cells. Polyglucose partices increased in number according to the degree of differentiation of tumor cells.
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PMID:Electron microscopic and electron histochemical studies on embryonal rhabdomyosarcoma of the orbit. 16 42

Supercoiled BK papovavirus DNA was shown to transform hamster kidney cells using the calcium phosphate co-precipitation technique. The transformed cells contained intranuclear T-antigen(s) and rescuable virus and produced progressively growing tumors when inoculated into hamsters. A novel finding was the production in tumor-bearing animals of antinuclear antibody, which reacted against normal, untransformed cells; in addition, tumor serum contained antibody against virus-specific T-antigen(s).
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PMID:Transformation of hamster kidney cells by BK papovavirus DNA. 17 87

The 3',5'-cyclic phosphate derivative (cMTIMP) of methylthioinosine (MTI) was shown to produce feedback inhibition of the de novo purine pathway in an Ehrlich ascites tumor subline resistant to MTI because of lack of adenosine kinase activity for the nucleoside analog.
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PMID:Feedback inhibition by 6-methylthioinosine 3',5'-cyclic monophosphate in tumor cells resistant to the nucleoside. 17 38

A case of watery diarrhea, hypokalemia and hypercalcemia associated with an islet cell tumor was described. A 62-year old man exhibited frequent watery diarrhea and hypokalemia for two years. He had no peptic ulcer and serum gastrin level was normal. His serum calcium was abnormally high and serum phosphate was lowered. He had secretin-like activity in his plasma. Autopsy revealed a small islet cell tumor in the pancreas and several metastatic masses in the liver. Microscopic examination revealed the tumor cell was not beta, alpha nor D cells. By electron microscopy the secretion granules of the tumor cell resembled those of S, M and T cells. It was not possible to decide which of the tree cell types was responsible for the pancreatic cholera.
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PMID:A case of watery diarrhea, hypokalemia and hypercalcemia associated with nonulcerogenic islet cell tumor of the pancreas. 17 23


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