Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Liver carcinogenesis was induced in rats by aflatoxin B1 (AFB1) enhanced by a choline-deficient diet. In Experiment 1, the ornithine decarboxylase inhibitor, alpha-difluoromethylornithine (DFMO), was administered by gavage to one group only during AFB1 administration; another group received DFMO during AFB1 administration and for 2 months after carcinogen administration. These two groups were compared to two control groups, one given AFB1 and fed the choline-deficient diet and another fed the deficient diet only. In a second experiment, DFMO was administered at a concentration of 2% in the water for 3 weeks and then at 1% for the remainder of the study. Rats from each group in Experiment 1 were killed at 2, 8, and 10 months after AFB1 administration and the development of tumors was followed by histology; autoradiography of [3H]thymidine incorporation into DNA; enzyme histochemistry; and alpha-fetoprotein determination. The group given DFMO during AFB1 administration was not significantly different from the AFB1-treated control group at 2 and 8 months after AFB1 administration. However, at 10 months following AFB1 and DFMO administration, the [3H]thymidine-labeling index and glucose-6-phosphatase staining were significantly increased. This group had three animals bearing hepatocellular carcinomas as compared to none in the controls. The group given DFMO for 2 months after AFB1 administration had a significantly depressed growth rate 2 months later, but this difference was not apparent after 8 months. After 10 months, there was a significantly increased [3H] thymidine-labeling index and increased volume fraction of gamma-glutamyltranspeptidase in the AFB1-DFMO-treated group as compared to the controls. DFMO appeared to inhibit growth under some conditions, but if administration was discontinued after AFB1 exposure, it appeared to enhance tumorigenesis. In Experiment 2, where a larger dose of AFB1 was used and DFMO was administered in the water from start to finish of the experiment, DFMO inhibited tumor induction and depressed the appearance of markers examined during carcinogenesis. These data indicate that the regimen used for DFMO administration can markedly affect tumor induction.
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PMID:Effects of the irreversible ornithine decarboxylase inhibitor, alpha-difluoromethylornithine, aflatoxin B1, and choline deficiency on hepatocarcinogenesis. 241 77

The presence of specific gamma-glutamyl transpeptidase isoenzyme (gamma-GTPI) and variant alkaline phosphatase (VAALP) were concurrently determined, and levels of basic fetoprotein (BFP) and carcinoembryonic antigen (CEA) in addition to alpha-fetoprotein (AFP) were measured in 144 hepatocellular carcinoma (HCC) patients in order to evaluate the diagnostic value of these tumor markers with respect to AFP-low or -negative patients and the tumor stage. Serum AFP levels below 400 ng/ml, commonly seen in sera of hepatobiliary diseases other than HCC, were noted in 42% of the patients. The diagnostic usefulness was increased by combination assay of these markers except for CEA. A definitive diagnosis of HCC could be made in 78% of the patients by a combination of gamma-GTPI, VAALP and AFP. Moreover, a diagnosis of malignancy could be made in 87% of cases by the inclusion of BFP. The prevalence of BFP and CEA increased in proportion to the tumor stage, whereas that of AFP and gamma-GTPI were independent of stage and were high even in patients in comparatively early stages. Furthermore, secreting type markers such as AFP and gamma-GTPI were relatively useful for diagnosis of HCC when the lesions were still small.
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PMID:Serum tumor markers in patients with hepatocellular carcinoma: diagnosis of alpha-fetoprotein -low or -negative patients. 241 27

From 1979 to 1984, we followed the cases of 3 men (aged 13, 31, and 75 yr) and 2 women (aged 38 and 45 yr who had never used oral contraceptives) suffering from liver adenomatosis, an uncommon lesion consisting of numerous benign adenomas in an otherwise normal hepatic parenchyma. During the same period, we observed 20 cases of liver adenoma (one tumor in 18 patients and two tumors in 2 patients). From these cases and the review of previously reported cases of liver adenomatosis and series of liver adenoma, the following distinctive characteristics of these two benign conditions of the liver can be outlined: liver adenomatosis affects men and women, whereas liver adenoma predominantly affects women; liver adenomatosis is unrelated, whereas liver adenoma is closely related, to oral contraceptive use; increases in serum alkaline phosphatase and gamma-glutamyl transpeptidase are common in liver adenomatosis, but are uncommon in liver adenoma.
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PMID:Liver adenomatosis. An entity distinct from liver adenoma? 241 30

Alpha-, beta-, and gamma-hexachlorocyclohexane (alpha-, beta-, gamma-HCH) isomers are widespread environmental pollutants; alpha-HCH can cause liver tumors in rats and mice. In the present study we have checked first the tumor-initiating activity of HCH using the appearance of phenotypically altered foci in female rat liver as an end point. Foci were identified by means of the gamma-glutamyltransferase (GGT) reaction and by morphological alterations. No evidence of initiating activity was found. Secondly, we have attempted to determine quantitatively the ability of HCH isomers to promote tumor development. For this purpose growth and phenotypic changes of foci were used as an end point. Rats received a single dose of N-nitrosomorpholine. Then five different doses of each HCH isomer or phenobarbital (PB) (as a positive control) were administered continuously via the diet for 4, 15, and 20 weeks. Both number and size of altered foci were enhanced by doses of 2 to 3 mg/kg or more of the three isomers; in addition, foci phenotypes showed a pronounced shift towards strong expression of GGT and sharp demarcation from the surrounding liver. Based on daily doses the three HCH isomers were approximately equipotent; based on concentrations in liver or adipose tissue, gamma-HCH was severalfold more effective than alpha- and beta-HCH. Thirdly, size and DNA and monooxygenase activities of the liver were determined. All three parameters were enhanced by HCH isomers and PB. However, no strict correlations were found. Rather, at the highest doses tested PB was the most effective inducer of monooxygenases, alpha-HCH was the most potent inducer of liver growth, and all three HCHs were more potent than PB as inducers of focal expansion. Thus, induction of liver growth appears to be associated with foci expansion (tumor promotion); however, neither liver growth nor monooxygenase induction can be used for quantitative predictions of foci expansion by chemical compounds. Finally, no-observed-effect levels were estimated for the parameters studied and are discussed in relation to human exposure.
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PMID:Dose-response studies on the effects of alpha-, beta-, and gamma-hexachlorocyclohexane on putative preneoplastic foci, monooxygenases, and growth in rat liver. 243 69

Early passage normal human fetal kidney epithelial cells were inoculated on top of a confluent monolayer of X-ray lethally irradiated human fibroblasts to determine the colony-forming ability of these epithelial cells. The results indicate that the great majority of the epithelial cells did not have the clonogenic ability on the fibroblast cell mat, although they were capable of colony formation on plastic surface without the cell mat. A small subpopulation of these epithelial cells, however, was able to proliferate on the cell mat. These contact-insensitive fetal epithelial cells were found to be deficient in gap junction-mediated intercellular communication, to contain keratin and gamma-glutamyl transpeptidase but not fibronectin. These contact-insensitive cells appear to have greater proliferative potential than the parental cell population and to exist transiently in early passage but not in late passage culture. The ability of proliferation on cell mat was found to be shared by 22 different human carcinoma cell lines that were tested. This unique clonogenic ability of normal contact-insensitive and human carcinoma cells on the cell mat could provide a selection method for presumptive normal stem and tumor cells and for an assay for screening potential antitumor drugs and assessing the efficacy of chemotherapeutic drugs against a given tumor.
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PMID:Contact insensitivity of a subpopulation of normal human fetal kidney epithelial cells and of human carcinoma cell lines. 243 22

Possibilities for the early diagnosis of hepatoma, gallbladder-biliary tract cancer and pancreas cancer became getting higher by using method of monoclonal antibody. AFP, gamma-GTP, hepatoma specific gamma-GTP, P-III-P, PIVKA-II and 5'-NPD-V are sensitive and useful markers for diagnosis of hepatoma, CA 19-9 and CEA for gallbladder-biliary tract cancer and pancreas cancer, and DUPAN-2 and POA for pancreas cancer. Screening of sera of the patients with these tumor markers combined with image diagnosis are necessary for early and accurate diagnosis of the cancers. Everlasting effort to get the more sensitive and specific tumor markers are necessary. And missile therapy binding anti-cancer drugs to monoclonal antibodies are expected.
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PMID:[Tumor markers in hepatoma, gallbladder-biliary tract and pancreas cancer]. 244 92

The role of carcinoembryonic antigen (CEA), gamma glutamyl transpeptidase (gamma GT), phosphohexose isomerase (PHI), pseudouridine (PSD) and acute phase reactant proteins (C-reactive protein (C-RP], alpha 1-acid glycoprotein (alpha 1-AGP) and alpha 1-antichymotrypsin (alpha 1-ACT) in distinguishing benign from malignant conditions of the digestive tract and their value in assessing the prognosis of gastrointestinal neoplasms was evaluated. For each marker it has been possible to produce a simple scoring index derived from the values found in the control population. This work suggests that pre-operative levels of certain cancer markers may be useful in tumor detection and may also give prognostic information additional to pathological staging.
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PMID:[Combination of cancer markers in the detection and prognosis of digestive system tumors]. 244 53

To elucidate the role and timing of expression of different premalignant and malignant markers in tumor promotion, we correlated alterations in keratin patterns and gamma-glutamyltransferase (GGT) expression with the chromosomal status of individual mouse skin papillomas. Papillomas were induced by 7,12-dimethylbenz[a]anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate promotion. Individual tumors were randomly sampled at 20 and 35 weeks of promotion. Each tumor was cytogenetically analyzed and serial paraffin sections were used for GGT detection, immunoblotting, and immunohistochemistry studies. Monospecific antibodies elicited against keratins K1 (Mr 67,000) and K14 (Mr 55,000) were used to analyze keratin modifications. Most tumors at 20 weeks of promotion, although exhibiting aneuploidy, still presented high levels of the K1 differentiation-associated keratin. Later during promotion those tumors bearing the highest aneuploidy indexes were those that showed a marked decrease in or absence of the K1 protein. Furthermore, those same tumors with the highest levels of genomic alterations also exhibited foci of GGT activity. These results support the idea that the majority of papillomas under continuous promotion are progressing toward malignancy. Aneuploidy seems to precede detectable keratin modifications, and GGT activity appears to be the latest marker to be expressed.
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PMID:Sequential development of aneuploidy, keratin modifications, and gamma-glutamyltransferase expression in mouse skin papillomas. 245 89

Some days after the administration of a third bolus of ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) a patient affected by immunoblastic lymphoma underwent a neurotoxic crisis. The episode lasted 1 week and was followed by a dramatic fall in plasma sodium (104 mEq I-1), associated with a proportionally lesser decrease in plasma chloride and phosphate. Despite the lowest plasma osmolality, detectable levels of circulating ADH were present. After 36 h the hyponatremic episode improved after the infusion of hypertonic sodium chloride. Nevertheless the patient lapsed into a hypotonic coma. The urinary concentrations of the main tubular enzymes (gamma-glutamyltranspeptidase, N-acetyl-glucosaminidase, alpha-glucosidase) proved very high and successively decreased slowly. The most likely cause of such hyponatremic episode is vinblastine. The drug acted through: (a) an already known inappropriate release of ADH, and (b) a hitherto unreported tubular lesion, which impaired the reabsorption of sodium and other coupled solutes.
Med Oncol Tumor Pharmacother 1988
PMID:Life-threatening hyponatremia caused by vinblastine. 245 36

Many structurally unrelated nonmutagenic peroxisome proliferators induce altered areas, neoplastic nodules, and hepatocellular carcinomas in rats. Unlike the lesions induced by genotoxic hepatocarcinogens, these lesions do not stain positively for the phenotypic markers gamma-glutamyl transpeptidase (GGT) and glutathione-S-transferase P (GST-P). To ascertain whether the absence of immunocytochemically detectable GST-P and GGT proteins in peroxisome proliferator-induced neoplastic lesions is due to the absence of specific mRNAs, we analyzed the total RNA isolated from hepatocellular carcinomas induced by three different peroxisome proliferators (ciprofibrate, Wy-14643, and BR-931) and the genotoxic carcinogens, 2-acetylaminofluorene and aflatoxin B1 (AFB), for the presence of GST-P, GGT, and alpha-fetoprotein (AFP) mRNAs. Northern and dot blot analysis of total RNA isolated from liver tumors induced by three different peroxisome proliferators revealed no detectable GST-P, GGT, and AFP mRNAs. GST-P mRNA was also not detected in a transplantable hepatocellular carcinoma established from a liver tumor induced by ciprofibrate. In contrast, GST-P mRNA levels were high in primary liver tumors induced by both 2-acetylaminofluorene and AFB and the two transplantable hepatocellular carcinomas established from such tumors. By immunoblot method, GST-P protein was found to be abundant in both primary and transplantable liver tumors induced by genotoxic carcinogens but not in those derived from peroxisome proliferator treatment. The GGT and AFP mRNAs were also not found in all 18 liver tumors induced by peroxisome proliferators that were analyzed and also in the ciprofibrate-derived transplantable liver tumor. The expression of GGT and AFP genes in liver tumors induced by 2-acetylaminofluorene and AFB was variable. These studies with peroxisome proliferators show that the GST-P and GGT gene derepression is not essential for the hepatocarcinogenesis or successful tumor transplantation. Further characterization of the molecular basis for the differential expression, particularly of the GST-P gene in liver tumors, may help identification of the critical event(s) in hepatocarcinogenesis by genotoxic carcinogens and nongenotoxic peroxisome proliferators.
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PMID:Lack of expression of glutathione-S-transferase P, gamma-glutamyl transpeptidase, and alpha-fetoprotein messenger RNAs in liver tumors induced by peroxisome proliferators. 245 33


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