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)

Lymphocytes from patients with neoplastic disease were tested for sensitization to encephalitogenic factor (EF) by the macrophage migration inhibition test. Sensitization to EF was demonstrated in 71% of patients with various forms of neoplastic disease. Sensitization to EF was also demonstrated for 31% of subjects with no evidence of neoplastic disease; these included patients with warts, chronic bronchitis and hernias. In contrast, healthy subjects showed no sensitization to myelin basic protein. These observations suggest that sensitization to EF may not be confined to patients with neoplastic disease. Lymphocytes from hamsters bearing a transplanted virus induced tumour were sensitized to EF prepared from both human and hamster brain. Sensitization was also seen in hamsters infected with influenza virus but not in animals with acute tubular necrosis produced by glycerol treatment. The development of an animal model system provides a method for the investigation of possible mechanisms of sensitization.
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PMID:Cellular immunity to myelin basic protein in man and in animal model systems as measured by the macrophage migration inhibition test. 5 Aug 55

Investigations on methods for the utilization of fluorescein-isothiocyanate-labelled Concanavalin A, Lens culinaris lectin and Ricinus communis lectin for immunohistological demonstration as simple sugar moieties are reported. The stainings were carried out on rabbit erythrocytes. Ehrlich ascitee tumor cells and various mammalian tissues. Optimum results were obtained in living cells and native cryostate tissue sections. The influence of different fixing agents and conditions of fixation on the degree of tissue flurorescence were studied. Generally the fluorescense decreased by aldehyde fixation. Similar effect was observed following fixation by heat. Furthermore, changes in the pattern of fluorescence depending on the type of tissue and utilized lectin were observed after aldehyde fixation. The degree of tissue fluorescence was fairly independent of the pH value. The specificity of the particular reactions for saccharide demonstration was shown; glycerol is capable of a differently strong "hapten-like" action.
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PMID:The use of flurorescein investigations with concanavalin A, Lens culinaris lectin and Ricinus communis lectin. 6 Nov 31

The RNA-directed DNA polymerase of murine mammary tumor virus, a type B RNA tumor virus, was purified sequentially through DEAE-cellulose, phosphocellulose (step gradient), and phosphocellulose (linear salt gradient) chromatography followed by glycerol sedimentation centrifugation. During all stages of purification, coincident peaks of RNA-directed DNA polymerase activity, templated by polyribocytidylate-oligodeoxyguanidylate, and RNase H digestion of [3H]polyriboadenylate-polydeoxythymidylate were observed, and both enzymatic activities displayed a cation preference for magnesium. Under conditions that removed adventitiously associated nucleases, RNase H activity was found to co-purify with polymerase. The specificity of this nuclease was assayed with various prepared substrates, which indicated that the polymerase-associated RNase H activity was directed only against the RNA strand of an RNA-DNA hybrid. It is highly probable that RNase H (RNA-DNA hybrid: ribonucleotide-hydrolase, EC 3.1.4..34) and RNA-directed DNA polymerase of type B viruses are associated enzymatic activities analogous to those observed for avian and mammalian type C RNA tumor viruses.
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PMID:RNase H and RNA-directed DNA polymerase: associated enzymatic activities of murine mammary tumor virus. 6 21

The kinetics of the stimulation of phospholipid and DNA biosynthesis in mouse epidermis after treatment with various tumor promoting agents has been investigated. 3H-choline and 3H-glycerol were used as precursors for phosphatidylcholine. An early stimulation of 3H-choline incorporation into phosphatidylcholine is observed which always precedes the stimulation of 3H-thymidine incorporation into epidermal DNA. This is interpreted as being a manifestation of the proliferation of cellular membranes in preparation for cell division. Appreciable differences are observed in the incorporation of 3H-choline and 3H-glycerol into phosphatidylcholine, the possible reasons for which are discussed. It is concluded that 3H-choline incorporation is a more reliable parameter for the measurement of phosphatidylcholine biosynthesis than 3H-glycerol incorporation. The relationship between those effects on phospholipid synthesis and the tumor promoting activity of the substances tested is discussed.
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PMID:On the biochemical mechanism of tumorigenesis in mouse skin. VII. The effects of tumor promoters on 3H-choline and 3H-glycerol incorporation into mouse epidermal phosphatidylcholine in relation to their effects on 3H-thymidine incorporation into DNA. 13

Circulating lipid levels and lipoprotein patterns in the Syrian hamster were determined at various times after subcutaneous inoculation with simian virus 40 (SV40) strain F, strain A-2895, or Fortner melanoma tumor cells. SV40 F tumors induced a rapid triphasic elevation of serum total lipids through inhibition of prebeta lipoprotein catabolism. Alpha lipoprotein levels declined in proportion to tumor mass. Liver wet weight and total lipid content increased significantly, but a normal rate of 3H-glycerol incorporation into polyanion precipitable (prebeta) serum lipoprotein was maintained. Determination of serum endogenous lipase, lecithin:cholesterol acyltransferase (LCAT), and cholinesterase activities indicated that these enzymes were not primarily responsible for the tumor-induced hyperlipidemia. Tumor-bearing animals also had selectively increased rates of protein and lipid excretion into the urine, with no evidence of gross hepatocellular or kidney damage. Growth of SV40 A-2895 tumors in hamsters resulted in a large increase in the rate of prebeta lipoprotein synthesis and degradation. Circulating prebeta lipoprotein levels were elevated much later in these animals, subsequent to a marked decrease in LCAT activity. Quite different results were obtained with Fortner melanoma, even large tumors having only a moderate effect on serum total lipid levels and lipoprotein patterns in the Syrian hamster.
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PMID:Effect of simian virus 40 subcutaneous tumors on circulating lipids and lipoproteins in the Syrian hamster. 16 32

Triglycerides from normal liver, host liver, and heptoma of rats maintained on chow and fat-free diets were subjected to sterospecific analysis. Normal and host liver triglycerides from animals on the same diet did not exhibit significant differences. Fat-free diet reduced polyunsaturated fatty acids in normal and in host liver triglycerides. Each position of hepatoma and liver triglyceride glycerol exhibited a characteristic fatty acid composition. Palmitate concentrations were reduced dramatically and stearate levels were increased significantly at the 1 position of hepatoma triglycerides, relative to the corresponding position of liver triglycerides which were affected little by diet ot tumor. Except for higher percentages of C-20 and higher fatty acids, common to all three positions, the composition of hepatoma triglycerides at the 2 position appeared normal. The 3 position of hepatoma triglycerides contained significantly higher percentages of stearate than liver. Data obtained previously for Ehrlich ascites cell triglycerides were in good agreement with this hepatoma. Data from these two neoplasms suggest that the metabolic system that regulates or controls the fatty acid composition at the 1 and 3 positions of normal tissue triglycerides does not function normally in neoplasms.
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PMID:Sterospecific analysis of hepatoma, host liver, and normal rat liver triglycerides from animals on chow and fat free diets. 16 60

The lymphoid cell line #1670 has been derived from the infiltrated spleen of a tumor-bearing marmoset monkey infected with Herpesvirus saimiri. The cells contain both types of H. saimiri DNA, unique light (L-) DNA (36% cytosine plus guanine) and repetitive heavy (H-) DNA (71% cytosine plus guanine), without producing infectious virus. Viral DNA was found to persist in these cells as nonintegrated circular DNA molecules. Closed circular superhelical viral DNA molecules were isolated by three subsequent centrifugation steps: (i) isopycnic centrifugation in CsCl, (ii) sedimentation through glycerol gradients, and (iii) equilibrium centrifugation in CsCl-ethidium bromide. The isolated circles had a molecular weight of 131.5 +/- 3.6 x 10(6). This is significantly higher than the molecular weight of linear DNA molecules isolated from purified H. saimiri virions (about 100 x 10(6)). Partial denaturation mapping of circular molecules from #1670 lymphoid cells showed uniform arrangement of H- and L-DNA sequences in all circles. All denatured molecules contained two L-DNA regions (molecular weights of 54.0 +/- 1.8 x 10(6) and 31.5 +/- 1.3 x 10(6)) and two H-DNA regions (molecular weight of 25.6 +/- 1.9 x 10(6) and 20.0 +/- 0.8 x 10(6)) of constant length. Maps of both L-regions suggested that the sequences of the shorter L-DNA region were a subset of those of the longer region. The sequences of both L-regions had the same orientation. Circular molecules from H. saimiri-transformed lymphoid cell line #1670 appeared to represent defective genomes, containing only 75% of the genetic information present in L-DNA of H. saimiri virions.
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PMID:Episomal viral DNA in a Herpesvirus saimiri-transformed lymphoid cell line. 19 90

When cultured normal and SV40-transformed normal rat kidney and BALB/3T3 cells were exposed to picolinic acid, cell proliferation ceases. Most of the normal cells remained in a quiescent G1 (G0) state and viable for prolonged periods of time. In contrast, SV40-transformed cells progressed to the S and G2 phases of the cell cycle and remained viable only up to 90 to 120 hr. Then, most of the cells began to die. However, a very small fraction of the cell population (approximately 0.01 percent) developed into variants resistant to picolinic acid. Prevention of development of variants, and therefore destruction of all transformed cells, was obtained by addition of glycerol to picolinic acid-treated cells. Untransformed cells were unaffected by the same treatment. These results suggest that differential tumor toxicity should be feasible.
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PMID:Selective toxicity induced by picolinic acid in simian virus 40-transformed cells in tissue culture. 20 Mar 44

Agents that increase (certain metabolic inhibitors, chemotherapeutic agents, and x-irradiation), decrease (hormones), or have no effect (hyperthermia) on the susceptibility of line-1 and line-10 guinea pig hepatoma cells to humoral immune attack were studied for their effects on the ability of these tumor cells to synthesize macromolecules. A correlation was found between the drug-induced increase in sensitivity of these cells to antibody-C mediated killing and the loss of their ability to incorporate fatty acids into complex cellular lipids. Similarly, the hormone-induced increase in resistance of the cells to killing was accompanied by an enhancement in complex lipid synthesis by these cells was also observed after the cells were exposed to physical means of insult (x-irradiation or hyperthermia). No correlation was found between the sensitivity of the cells to antibody-C mediated killing and their ability to synthesize DNA, RNA, protein, or complex carbohydrate, or their capacity for de novo lipid synthesis as measured by incorporation of acetate and glycerol into cellular macromolecules. The assembly of free fatty acids into complex lipid moieties is therefore proposed to be of fundamental importance for the ability of the tumor cells to resist humoral immune killing.
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PMID:Correlation between the ability of tumor cells to resist humoral immune attack and their ability to synthesize lipid. 20 52

Certain metabolic inhibitors or chemotherapeutic agents that increase the susceptibility of line-1 or line-10 guinea pig hepatoma cells to humoral immune attack were studied for their effects on the ability of the cells to synthesize lipids. A direct correlation was found between the drug-induced increase in sensitivity to antibody-C mediated killing and the inhibition of the ability of the cells to incorporate acetate, glycerol, and fatty acids into complex cellular lipids. Drug-treated cells recultured in drug-free medium regained their resistance to antibody-C mediated killing; these cells recovered their ability for complex lipid synthesis at this time. Thin layer chromatography of CHCl3:CH3OH lipid extracts from these cells indicated that the drug-induced increase in susceptibility to humoral immune attack correlated with the inhibition of acetate, glycerol, and fatty acid incorporation into cardiolipin and triglyceride in line-10 cells and the inhibition of incorporation of these compounds into cardiolipin alone in line-1 cells. No direct correlation was found between the sensitivity of the cells to humoral immune attack and the ability of the cells to incorporate precursors of lipid synthesis into other lipid moieties (sphyngomyelin, phosphatidyl serine, phosphatidyl choline, phosphatidyl glycerol, or cholesterol esters). The synthesis of cardiolipin and triglycerides, therefore, appears to be associated with the mechanism whereby these tumor cells resist antibody-C mediated killing.
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PMID:Identification of lipids associated with the ability of tumor cells to resist humoral immune attack. 20 53


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