UMLS:C0024623 - FACTA Search

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Query: UMLS:C0024623 (gastric cancer)
36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ingested nitrate and nitrite have been shown to contribute to endogenous, N-nitroso compound formation in man and experimental animals. N-nitroso compounds have long been suspected of contributing to higher levels of gastric cancer in various populations. Reconstructive gastric surgery to treat ulcers is accompanied by a change in bile reflux, gastritis and an increased incidence of gastric cancer in humans. To evaluate possible connections between gastric nitrite processing, reconstructive surgery and gastric cancer, the surgically altered domestic ferret, Mustela putorius furo, was used as an experimental model. The aim of the study was to determine if surgery would alter the stomach in a way which would increase gastric nitrite concentration, and thereby enhance the likelihood of gastric N-nitroso compound formation. Three groups of ferrets, one control group (n = 6) and two groups of surgically altered ferrets, one to simulate maximal bile reflux (MABR, n = 6), and the other to model minimal bile reflux (MIBR, n = 7), were studied. Each group's response to an exogenously administered dose of sodium nitrite did not differ significantly with respect to rate of gastric nitrite absorption, with half-lives in the 13-min range. Permeability of gastric mucosa to nitrite did not differ between controls and MIBR ferrets. Mean doubling time of gastric nitrate appeared slowed in surgically altered ferrets. Mean rate of gastric emptying was the same in the three groups, but appeared delayed initially in MIBR ferrets. Thiocyanate concentrations, pH and HCl secretion, all parameters which have been shown to affect gastric nitrite processing, did not differ significantly between groups. Gastric mucosal endoscopic biopsies obtained at 6-month intervals showed no clear difference in degree of mucosal inflammation and/or dysplasia in the three groups. These findings indicate that gastric mucosal neoplasia has not occurred in this model and that changes in parameters favoring gastric N-nitrosation, even if relevant to the disease process, are not apparent at this time.
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PMID:Gastric nitrite processing in the surgically altered maximal and minimal bile reflux ferret model. 231 Nov 83

Bromodeoxyuridine (BUDR) is a non-radioactive thymidine analogue which is incorporated into the DNA of proliferating cells. This allows evaluation of the size of the S-phase as the BUDR labelling index (BUDR-LI) not only in vitro but also in vivo, since BUDR is not toxic at the doses needed to label cells. To ascertain whether in vivo BUDR incorporation can be detected on routine histological material we tested several different procedures prior to immunoperoxidase staining, on formalin-fixed, paraffin-embedded sections from five patients with gastric cancer, who received BUDR (250 mg m-2, intravenous) 4 h before surgery. To determine the optimal conditions for detecting BUDR in formalin-fixed tissues, immunohistochemical testing for BUDR was performed simultaneously on duplicate sections fixed with 70% ethanol. It was found that hydrolysis with 3N HCl at 37 degrees C for 30 min and digestion with 0.5% in at 37 degrees C for 30 min were sufficient to detect BUDR immunoreactivity in formalin-fixed sections. The method presented extends the range of applications of the in vivo BUDR technique for cell kinetics studies in human neoplasms because it can be used on routinely fixed archival material, with the advantage of correlating the kinetic data with histopathological characters.
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PMID:In vivo bromodeoxyuridine incorporation in human gastric cancer: a study on formalin-fixed and paraffin-embedded sections. 284 78

A newly established cancer marker, the PFK inhibition test, has been further examined for its capacity to detect malignant neoplasms irrespective of the organs in which cancer cells start proliferating. We tested 1,160 sera from cancer patients and compared them with 756 normal sera, using histograms and normal paper for analysis of accumulated frequency. PFK activity through the influence of normal sera showed normal distribution, and cancerous sera shifted to the inhibitory site with an irregular shape. From these analyses, the patients were classified into the following types: normal range: PFK greater than SD (standard deviation of PFK activity in normal sera); suspicious range: SD greater than PFK greater than 2SD, must be given the PFK test again; and dangerous range: PFK less than 2SD, further examination must be carried out to detect cancer. Fifty percent of the sera from all the cancer patients inhibited PFK beyond 2 SD of normal sera. We also analyzed organ-associated PFK distribution, eg, gastric, colorectal, and mammary cancer. In gastric cancer, PFK inhibition was stronger in accordance with how far a particular stage of cancer had progressed. However, 50% of sera from stage I gastric cancer patients was positive beyond the cut-off line of 2 SD. We examined 104 sera from patients diagnosed as benign prostatic hypertrophy and found malignant cells in 10 patients whose sera tended to be positive in PFK inhibition. The PFK inhibitory factor in the body fluids of cancer patients was fractionated by Sephadex G-75 gel filtration and DEAE ion exchange chromatography. The approximate molecular weight of this factor was 13,000 daltons. The factor was resistant to heat and acid (0.1 N HCl and H2SO4) and was sensitive to 0.1 N NaOH and phosphate buffer. Diluted sulfuric acid and ammonium sulfate made an inactive NaOH-treated sample active when lyophilized following dialysis against distilled water. PFK inhibition by cancerous sera was eliminated by fructose-2,6-bisphosphate (the strongest activator of PFK) in a dose-dependent manner. PFK attached to agarose beads was found to be reversible even after being inhibited by cancerous body fluids and ATP water solution. Although PFK is apt to decay in a low pH range, the established procedure did not destroy PFK, but induced a direct inhibition of PFK by ATP through the ATP inhibition site on the PFK molecule. The PFK inhibitor may possibly function as a proton carrier and release protons to activate the ATP inhibition site.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:PFK inhibition test for cancer detection: clinical applications and mechanisms of PFK inhibition. 295 72

A correlation between cimetidine and gastric cancer has been suggested. Nitrosation of cimetidine in the presence of nitrite and HCl and mutagenic activity as well as DNA damage in mammalian cells displayed by nitrosocimetidine, as these phenomena occur in vitro, were the supporting hypothesis. Previous studies have shown that liver DNA damage was a well correlated index of potential carcinogenic activity of N-nitroso compounds and that such a damage was found after long-term simultaneous oral administration of aminopyrine and nitrite in rats. In this work, liver DNA fragmentation was investigated by three different techniques: DNA alkaline elution, DNA alkaline denaturation followed by hydroxylapatite chromatography and a new viscometric method markedly more sensitive than the above mentioned ones in detecting DNA damage. Evidence of DNA damage was not gained in any of the groups of rats treated with high single or successive oral daily doses of cimetidine (250 mg/kg) along with nitrite (80 mg/kg) in approximately equimolar amounts. Cimetidine and nitrite given alone were also ineffective. The lowering of gastric pH, obtained with fasting and histamine administration before giving cimetidine and nitrite combination in a single dose, did not favor the induction of liver DNA fragmentation neither in the above condition nor even when the amount of cimetidine was lowered to 125 mg/kg in order to obtain an approximately 2-fold molar amount of nitrite.
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PMID:Absence of DNA damage in liver of rats given high doses of cimetidine and sodium nitrite. 706 84

5-fluorouracil (5-FU)/methotrexate (MTX) sequential chemotherapy is one of the standard regimen for the treatment of gastric cancer. Though this combination therapy is highly effective, the mechanism is still unclear. In this study, we investigated the relationship between antitumor activity and the inhibition of thymidylate synthase and between antitumor activity and incorporation of 5-FU into RNA (F-RNA) in mice bearing Sarcoma-180 treated by tegafur alone (100 mg/kg) or by the combination of MTX (42 mg/kg) and tegafur (100 mg/kg). A new method for the determination of F-RNA of tumor tissue samples was used. Briefly, RNA fractions containing incorporated 5-FU were extracted by KOH hydrolysis. FUra in RNA fractions was released by HCl hydrolysis and its levels were determined by GC-MS. The results showed that the F-RNA levels were significantly elevated by the pretreatment of MTX. According to this result, it is suggested that the measurement of F-RNA levels together with the determination of FUra concentration and the inhibition rate of thymidylate synthase were considered as a good means for the evaluation of antitumor efficacy of FUra. We concluded that the impairment of RNA metabolism played a major role in the antitumor activity of MTX/5-FU combination.
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PMID:[The mechanism of biochemical modulation in methotrexate/5-fluorouracil sequential chemotherapy]. 797 18

In vitro labelling index (L.I.) of bromodeoxyuridine (BrdU) was evaluated as a preoperative predictor of gastric cancer development. Biopsy specimens were obtained endoscopically from 187 gastric cancer patients preoperatively. Specimens were incubated in RPMI containing BrdU under carbogen gas at 3 times atmospheric pressure. They were fixed and embedded in paraffin. After slicing and dewaxing, they were denatured in 2N HCl. Then BrdU were stained by ABC method and labelling index was calculated. Patients with L.I. more than 10% had a significantly higher risk of lymph node involvement (p < 0.001) and venous invasion (p < 0.05). Those with L.I. more than 20% had a significantly higher risk of liver metastasis (p < 0.01), while patients with L.I. more than 25% had a significantly higher risk of submucosal invasion (p < 0.01). In conclusion in vitro BrdU labelling is a technique available as a preoperative predictor of node involvement, venous invasion, submucosal invasion and prognosis in gastric cancer.
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PMID:[Preoperative prediction of gastric cancer development by in vitro labelling index of bromodeoxyuridine]. 848 87

Helicobacter pylori infection is often associated with gastrointestinal diseases, such as chronic gastritis, peptic ulcer, and gastric cancer. After total gastrectomy, positive to negative seroconversion of the H. pylori IgG antibody assayed by enzyme-linked immunosorbent assay (ELISA) was found in 10/15 patients (67%) an average of 8.5 months after surgery. Therefore, the IgG antibody persists for a long time after total removal of the stomach in about 30% of patients. Immunoglobulin A (IgA) is a major component of the local immunity of the stomach mucosa and has a short half-life. Therefore, tissue H. pylori IgA antibodies in biopsy specimens from patients with various gastric diseases were assayed by ELISA and compared with the bacterial culture, serum IgG antibody (ELISA), and [13C]urea breath test results from 144, 170, and 123 endoscopic examinations, respectively. Positivity and negativity of tissue H. pylori IgA coincided with the culture results in 67% of the examinations, and positive IgA antibody but negative culture results were found in 23%. The coincidence of tissue IgA and serum IgG antibodies against H. pylori was 64% and that of negative tissue IgA but positive serum IgG antibody results was 36%. Positivity and negativity of tissue H. pylori IgA antibody coincided with the [13C]urea breath test results in 72%. One month after completion of treatment of peptic ulcer patients for H. pylori infection with lansoprazole and benexate HCl betadex plus amoxicillin, 6/9 (67%) patients showed positive to negative conversion of the tissue IgA antibody, in contrast to no IgG antibody seroconversion. In conclusion, the tissue H. pylori IgA antibody assay is useful for detection of local immunity against H. pylori in the stomach and during follow-up after treatment.
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PMID:Tissue IgA antibody against Helicobacter pylori in patients with gastroduodenal diseases: comparison with bacterial culture, serum IgG antibody, and [13C]Urea breath test. 877 8

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30 degree C for 20 min (DNA-instability test) has been used as a marker of malignancy. The test was applied to bioptic tissues of human gastric polyp assessed histopathologically as foveolar hyperplastic polyp (13 cases), mild (58 cases), moderate (86 cases), and severe (20 cases) dysplasia, and adenocarcinomas (14 cases). The serial sections of the same tissues were also subjected to immunohistochemical staining for Ki67, p53, DNA-fragmentation factor (DFF45), and basic fibroblast growth factor (bFGF). The DNA-instability test was positive in 14 (100%) adenocarcinoma cases, 20 (100%) severe dysplasia cases, 52 (60.5%) moderate dysplasia cases, and 12 (20.7%) mild dysplasia cases, indicating malignancy. All foveolar hyperplastic polyps were negative to the DNA-instability testing. Furthermore, the percentage of glands positive in the DNA-instability test steadily increased in going from mild (10%), to moderate (40%), to severe (100%) dysplasia, and adenocarcinoma (100%). All other biological markers tested in the present study showed significantly higher values in the adenoma glands, being positive to DNA-instability testing, irrespective of the dysplasia grade, as compared to those in the adenoma glands that were negative to DNA-instability testing. Furthermore, the former values were comparable to those in adenocarcinoma. These results indicate that cancer cell clones are already present at the adenoma stages showing a positive DNA-instability test, enhanced proliferative activity, p53 mutation, induction of DFF45 and bFGF. These factors allow cancer cell proliferation, producing heterogeneous subclones due to DNA-instability, enhancing their survival by escaping apoptosis, and providing abundant nutrients during the early-stage progression of gastric cancer. Based on these findings, we herein propose the concept of "procancer" (as opposed to "pre-cancer") as being a unique stage during the course of carcinogenesis and cancer progression. We designate the term to cancer clones at the very early stages of malignant progression that do not show distinguishable morphological atypia but do show positive DNA-instability testing and positive staining for various biomarkers such as Ki67, p53, DFF45, and bFGF. We also define the abnormal positive staining of these biomarkers, including the DNA-instability test as "functional atypia", compared to the ordinary morphological atypia.
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PMID:Detection of cancer clones in human gastric adenoma by increased DNA-instability and other biomarkers. 1277 6

Whereas nitrosation of secondary amines produces nitrosamines, amino acids with primary amino groups and glycine ethyl ester were reported to react with nitrite to give unidentified agents that alkylated 4-(p-nitrobenzyl)pyridine to produce purple dyes and be direct mutagens in the Ames test. We report here that treatment of glycine ethyl ester at 37 degrees C with excess nitrite acidified with HCl, followed by ether extraction, gave 30-40% yields of a product identified as ethyl chloro(hydroximino)acetate [ClC(=NOH)COOEt, ECHA] and a 9% yield of ethyl chloroacetate. The ECHA was identical to that synthesized by a known method from ethyl acetoacetate, strongly alkylated nitrobenzylpyridine, and may have arisen by N-nitrosation of glycine ethyl ester to give ethyl diazoacetate, which was C-nitrosated and reacted with chloride to give ECHA. Nitrosation of ethyl diazoacetate also yielded ECHA. Ethyl nitroacetate was not an intermediate as its nitrosation did not produce ECHA. ECHA reacted with aniline to give ethyl (hydroxamino)(phenylimino)acetate [PhN=C(NHOH)CO2Et]. This product was different from ethyl [(phenylamino)carbonyl]carbamate [PhNHC(=O)NHCO2Et], which was synthesized by reacting ethyl isocyanatoformate (OCN.CO2Et) with aniline. ECHA reacted with guanosine to give a derivative, which may have been a guanine-C(=NOH)CO2Et derivative. ECHA showed moderate toxicity and weak but significant mutagenicity without activation in Salmonella typhimurium TA-100 (mean, 1.31 x control value for 12-18 microg/plats) and for V79 mammalian cells (1.5-1.7 x control value for 60-100 microM). In conclusion, gastric nitrosation of glycine derivatives such as peptides with a N-terminal glycine might produce ECHA analogues that alkylate bases of gastric mucosal DNA and thereby initiate gastric cancer.
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PMID:Nitrosation of glycine ethyl ester and ethyl diazoacetate to give the alkylating agent and mutagen ethyl chloro(hydroximino)acetate. 1502 13

In this study we investigated the effects of constituents of Amomum xanthioides (AX) on gastritis in rats and on the growth of human gastric cancer cells. The ethanol extract of Amomum xanthioides significantly inhibited HCl ethanol-induced gastric lesions and the growth of Helicobacter pylori (H. pylon). The ethanol extract of AX was further fractionated with hexane, chloroform, butanol and H20. Among these fractions, oral treatment with the butanol fraction at a dose of 350 mg/kg was the most effective at preventing HCl* ethanol-induced gastric lesions. In pylorus ligated rats, the butanol fraction also decreased the volume of gastric secretion and gastric acid output. We isolated six subfractions of the butanol fraction using open column chromatography. Subfraction 4 (150 mg/kg) significantly inhibited HCl* ethanol-induced gastric lesions and gastric secretion in pylorus ligated rats. Using GC-MS we identified the constituents of subfraction 4 to be five aliphatic compounds, 1-hexadecene, 1-nonadecene, cycloeicosane, 1-octadecene and cyclotetracosane. In addition, subfraction 4 reduced cell viability in a dose-dependent manner in human gastric cancer cells (AGS, KATOIII and SNU638). It also increased intracellular Ca2+ concentration in SNU638 cells, an effect that was significantly inhibited by dantrolene, a Ca2+ release blocker. Moreover, dantrolene significantly inhibited subfraction 4-induced cytotoxicity. Taken together, these results suggest that subfraction 4 of the butanol extract of AX has an anti-gastritic effect in rats and is cytotoxic to human gastric cancer cells. The mechanism of its anti-gastritic action may be associated with the inhibition of secretion of gastric acid and anti-H. pylori action. Its cytotoxicity against human gastric cancer cells may be, at least in part, mediated by intracellular Ca2+ dyshomeostasis. From these results, we suggest that AX may be useful for the treatment of gastritis and gastric cancer.
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PMID:Effects of constituents of Amomum xanthioides on gastritis in rats and on growth of gastric cancer cells. 1748 59

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