Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitrite and hydrogen ion concentrations have been measured in the fasting gastric juice of 69 patients undergoing routine gastrointestinal investigations. There was an inverse relationship between nitrite concentration and hydrogen ion concentration, with a highly significant increase in gastric-juice nitrite in hypochlorhydric subjects. Thiocyanate was also found in all specimens in concentrations likely to increase nitrosamine formation, if nitrosation of amines occurs in the fasting stomach. Neutral gastric juice contains metabolically active bacteria capable both of generating nitrite from nitrate and of catalysing nitrosation. In this way an intragastric environment suitable for the formation of carcinogenic nitrosamines exists in the hypochlorhydric and achlorhydric stomach, providing a possible mechanism for the high incidence of gastric cancer in these subjects.
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PMID:Gastric-juice nitrite. A risk factor for cancer in the hypochlorhydric stomach? 6 96

Proton beam radiation therapy using 250 MeV protons was carried out on two patients with early gastric cancer (T1, N0, M0). One patient was an 85-year-old man with early gastric cancer of type IIa + IIc. The other one was a 70 year old man with early gastric cancer of type IIc. In both cases histological examination of biopsy specimens showed differentiated adenocarcinoma; distant metastasis was not found by other examinations. Both patients were considered inoperable due to their poor cardiac and/or respiratory functions. Therefore, it was decided to treat them by definitive proton irradiation, delivering total doses of 86 Gy and 83 Gy, respectively. In both patients, skin erythema that did not require any special treatment was found in the irradiation field. Hematobiological examinations did not show any abnormality. Although endoscopic examination at two years after irradiation in the former case and at seven months in the latter case showed persistent gastric ulcer at the site of the cancerous lesions, cancer cells were not found histologically. Therefore, we concluded that proton irradiation therapy was useful for inoperable early gastric cancers.
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PMID:Definitive proton beam radiation therapy for inoperable gastric cancer: a report of two cases. 164 84

We examined the effects of misonidazole (MISO) and recombinant human tumour necrosis factor (rh-TNF) on tumour blood flow in mice given hyperthermic treatments. MISO (500 mg kg-1) or rh-TNF (6 x 10(4) unit kg-1) was administered intraperitoneally (i.p.) prior to hyperthermia to nude mice bearing a xenoplanted human gastric cancer and tumour blood flow was measured by a hydrogen diffusion method based on polarographic determinations. MISO plus hyperthermia produced a temperature-dependent decrease in blood flow and, at 43.5 degrees C, the flow decreased to 15-30% of control and remained low for up to 24 h. Blood flow following rh-TNF plus hyperthermia was less than that at the same temperatures following MISO plus hyperthermia, and, at 43.5 degrees C, the flow decreased to 10-20% of control and remained low for up to 48 h. Tumour growth delay was closely related to the duration of the decrease in blood flow. Thus, the profound decrease in tumour blood flow following hyperthermia plus MISO or rh-TNF and the consequential tumour regression may well be of potential clinical significance.
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PMID:Effects on tumour microcirculation in mice of misonidazole and tumour necrosis factor plus hyperthermia. 173 39

Hyperthermia combined with recombinant human tumour necrosis factor (rH-TNF) was evaluated for antitumour efficacy in vivo. Use was made of human gastric cancer tissues xenografted into nude mice. When 100, 300, 600, and 1200 units of rH-TNF (2.4 x 10(6) units/mg protein) were given twice intraperitoneally, tumour regression did not occur in any animal. In contrast, a remarkable suppression of tumour growth was observed when 600 and 1200 units of rH-TNF was given in combination with hyperthermia at 43.5 +/- 0.1 degrees C. No effects were evident with the regimen of 100 and 300 units of rH-TNF plus hyperthermia at the same temperature, as compared with evidence obtained with hyperthermia alone. The tumoral blood flow, determined by the hydrogen diffusion method, decreased immediately after hyperthermia alone or hyperthermia plus 1200 units of rH-TNF, whereas a slight decrease was seen after rH-TNF alone. When hyperthermia plus 1200 units of rH-TNF were given, there was a remarkable delay in reversion to pretreatment values of tumoral blood flow, as compared to findings with rH-TNF only or heat only. These results are discussed in relation to the antitumour and side-effects of rH-TNF.
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PMID:Augmented antitumour effects of combined treatment with hyperthermia and tumour necrosis factor on human gastric cancer xenotransplanted into nude mice. 191 46

In vitro thermosensitivity of various human tumors including 90 esophageal, 10 gastric and 40 colo-rectal cancers were evaluated using the succinate dehydrogenase inhibition (SDI) test. Tumor fragments minced with scissors were incubated at 43 degrees C as heat treated cells and at 37 degrees C as controls for 20 hrs, and assayed for the succinate dehydrogenase (SD) activity using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. The thermosensitivity was estimated by the percentage of SD activity of heat treated cells compared to that of each control. A variation in the thermosensitivity was noted between patients. The SD activity was 60.1 +/- 20.3% (mean +/- standard deviation) for esophageal cancers, 34.9 +/- 21.7% for gastric cancers, 50.3 +/- 20.6% for colo-rectal cancers. Significant differences were noted between esophageal cancers and gastric cancers, colo-rectal cancers (p less than 0.01 and p less than 0.05, respectively). When the thermosensitivity was arbitrarily defined as reduction in the SD activity to 50% of control or less, the positive rates were 31.1% for esophageal cancer, 70% for gastric cancer and 62.5% for colo-rectal cancer. Our results show that the SDI test is a useful method for determination of the thermosensitivity of clinical samples.
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PMID:[In vitro thermosensitivity of various human tumors evaluated using the SDI (succinate dehydrogenase inhibition) test]. 223 61

The aim of this study was to examine the effect of pH on the measurement of carcino-embryonic antigen (CEA), and to assess the efficacy of a combination of serum and gastric juice levels of CEA and Carbohydrate Antigen 19.9 (CA 19.9) in the diagnosis of gastric carcinoma. An initial experiment was performed to determine the effect of pH on the CEA assay. There was a direct linear relationship between pH and the concentration of CEA measured by the assay, such that as hydrogen ion concentration increased, the apparent concentration fell. The correct value was measured at pH 7. Seventy-six normal patients with non-malignant upper gastro-intestinal disorders, and 49 patients with gastric carcinoma were studied, two of which were 'early' gastric carcinomas. All patients underwent upper GI endoscopy, and at this examination blood and gastric juice were taken for analysis. A 'normal range' was constructed as a 95% confidence interval for each of the antigens in serum and gastric juice. The highest sensitivity was achieved using a combination of the two antigens, CEA and CA 19.9 in gastric juice and serum, with a sensitivity of 95.7% and a specificity of 50%. This combination of assays could have value in a screening programme for gastric cancer.
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PMID:CEA and CA 19.9 in gastric juice and serum: an aid in the diagnosis of gastric carcinoma? 273 12

In vitro chemosensitivity was evaluated by SDI test in various human tumors including 1 lymph node metastasis of esophageal cancer, 10 gastric cancers, 4 colo-rectal cancers, 1 hepatoma, 2 lung cancers, 2 breast cancers and 1 gallbladder cancer. Tumor fragments cut with scissors were exposed to twelve kinds of antitumor drugs at five to ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline and assayed for succinate dehydrogenase (SD) activity using 3-(4,5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. When the SD activity of the drug-treated cells was reduced to below 50% that of control cells, the chemosensitivity to the antitumor drug was considered positive. The chemosensitivity of each tumor varied individually. Mitomycin C or 5-fluorouracil are regularly used to treat gastric cancer patients, but, some specimens of gastric cancer in this study showed a resistance to these drugs and an unexpected sensitivity to other drugs. Our results show that the SDI test is a convenient method for clinical use and gives significant information about drug sensitivity.
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PMID:[In vitro chemosensitivity of various human tumors evaluated by the SDI (succinate dehydrogenase inhibition) test]. 405 18

Oxidant stress is thought to play a role in the pathogenesis of many gastric disorders. We have recently reported that histidine decarboxylase (HDC) promoter activity is stimulated by gastrin through a protein kinase C- and extracellular signal-regulating kinase (ERK)-dependent pathway in gastric cancer (AGS-B) cells, and this transcriptional response is mediated by a downstream cis-acting element, the gastrin response element (GAS-RE). To study the mechanism through which oxidant stress affects gastric cells, we examined the effects of hydrogen peroxide (H2O2) on HDC promoter activity and intracellular signaling in AGS-B cells. H2O2 (10 mM) specifically activated the HDC promoter 10-12-fold, and this activation was blocked by both mannitol and N-acetylcysteine. Hydrogen peroxide treatment of AGS-B cells increased the phosphorylation and kinase activity of ERK-1 and ERK-2, but did not affect Jun kinase tyrosine phosphorylation or kinase activity. In addition, treatment of AGS-B cells with H2O2 resulted in increased c-fos/c-jun mRNA expression and AP-1 activity, and also led to increased phosphorylation of epidermal growth factor receptor (EGFR) and Shc. H2O2-dependent stimulation of HDC promoter activity was completely inhibited by kinase-deficient ERKs, dominant-negative (N17 and N15) Ras, and dominant-negative Raf, and partially blocked by a dominant-negative EGFR mutant. In contrast, protein kinase C blockade did not inhibit H2O2-dependent induction of the HDC promoter. Finally, deletion analysis demonstrated that the H2O2 response element could be mapped to the GAS-RE (nucleotides 2 to 24) of the basal HDC promoter. Overall, these studies suggest that oxidant stress activates the HDC promoter through the GAS-RE, and through an Ras-, Raf-, and ERK-dependent pathway at least partially involving the EGFR.
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PMID:Oxidative stress activates the human histidine decarboxylase promoter in AGS gastric cancer cells. 972 30

Stomach and small bowel both influence gastrointestinal motility. We studied which portion of the stomach was essential for the regulation of gastrointestinal movement and determined the role of vasoactive intestinal polypeptide in this regulation. The study subjects consisted of 45 controls, 46 patients after subtotal gastrectomy, and 13 patients after total gastrectomy for stomach cancer. Orocecal transit time was measured, using the hydrogen breath test, to represent gastrointestinal movement, while plasma vasoactive intestinal polypeptide level was simultaneously assessed. The orocecal transit times in the study groups were (means +/- SD) 91.1 +/- 45.0, 57.1 +/- 34.3, and 60.8 +/- 34.8 min, respectively (P < 0.01). In the subtotal gastrectomy patients, age showed a negative correlation with orocecal transit time (r = -0.388; P < 0.01). In the total gastrectomy patients, no particular demographic factor influenced orocecal transit. Plasma vasoactive intestinal polypeptide levels in the three groups were 20.7 +/- 10.8, 22.7 +/- 10.9, and 20.6 +/- 9.1 pg/ml, respectively (NS). We conclude that both types of gastrectomies enhanced gastrointestinal movement, showing a similar effect, and that the distal stomach plus pylorus are most likely to exert an important inhibitory mechanism in the regulation of this movement. Vasoactive intestinal polypeptide is not a major peptide mediating this regulation.
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PMID:Distal stomach appears essential in the regulation of gastrointestinal transit. 1086 48

The authors have hypothesized that dietary iodine (deficiency or excess) is associated with the development of some gastric and mammary cancers, as it is well-known for thyroid cancer. They report a short review of their own work and of the general literature on this correlation and on the antioxidant function of iodide in stomach, breast and thyroid. Thyroid cells phylogenetically derived from primitive iodide-concentrating gastroenteric cells which, during evolution, migrated and specialized in uptake and storage of iodine, also in order to adapt the organisms from iodine-rich sea to iodine-deficient land. Mammary cells also derived from primitive iodide-concentrating ectoderm. Stomach, breast and thyroid share an important iodide-concentrating ability and an efficient peroxidase activity, which transfers electrons from iodides to the oxygen of hydrogen peroxide and so protects the cells from damage caused by lipid peroxidation. The authors suggest that iodide might have an ancestral antioxidant function in all iodide-concentrating cells from primitive Algae to more recent Vertebrates. In Italy, gastric cancer is more frequent in farmers and in iodine-deficient populations, living in mountainous and hilly areas, than in fishermen. In the last two decades, Italian decrease of gastric cancer seems to be correlated more to the higher dietary consumption of iodine-rich fish rather than to consumption of fruit and vegetables, which indeed has decreased in Italy.
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PMID:Role of iodine in evolution and carcinogenesis of thyroid, breast and stomach. 1093 94


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