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)

Pepsin is a potent proteolytic enzyme stored and secreted by chief cells in an inactive precursor form, pepsinogen. Its secretion is modulated by both cAMP and calcium-dependent mechanisms. Abnormalities in levels of pepsinogen and its various isozymogens have been linked clinically, epidemiologically, and experimentally to peptic ulcer disease and gastric carcinoma. The ulcerogenesis of pepsin stems from its ability to breach gastroduodenal mucosal barriers. Furthermore, certain isozymogens seems abundant and hyperactive in patients with peptic ulcer disease. The etiology and significance of low pepsinogen levels with disproportionate elevations of pepsinogen II and pepsin 5 in gastric cancer and its precursors is less clear. Further exploration of the patho-physiologic role of pepsin is likely to be of considerable importance in initiating further advances in the understanding and treatment of upper gastrointestinal disease.
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PMID:Pepsinogen. Prolate ellipsoid or unrecognized pathogen? 330 25

In this paper the role of pepsinogen has been reviewed in its physiological and clinical aspects. Although acid secretion has traditionally received far more attention clinically and has therefore been studied in great detail, the development of cellular systems has recently seen a revival in interest of pepsinogen secretion. These systems have made it possible to study pepsinogen secretion in more detail. Although many questions remain unanswered, a picture of a stimulus-secretion coupling mechanism of the chief cell has emerged that resembles in many aspects the pancreatic acinar cell, but also possesses some unique features of its own. The chief cell monolayer culture has also made it possible to study pepsinogen synthesis, and these studies seem to have solved the old controversy of whether or not modulation of pepsinogen synthesis occurs as a result of increased secretion. It now seems that pepsinogen synthesis does indeed increase in response to stimulated secretion. In addition to physiological studies, this review has discussed clinical aspects of the human pepsinogens in various gastric disorders. The clinical implications of genetic heterogeneity of the human pepsinogens are especially intriguing. Relationships between certain PGA phenotypes and certain gastric disorders have been described and some studies have tried to evaluate the relevance of these findings for diagnostic purposes. So far, it seems that PGA phenotyping alone has only limited diagnostic value, but, in combination with serum PGA determinations, could be of additional help in the diagnosis of gastric malignancy. In addition, various studies suggest that the ratio of serum PGA and PGC levels may be helpful in determining the histological status of the gastric mucosa. A very promising possibility in solving the many problems involved in exact genotype determinations through phenotyping is the recent availability of cDNA probes. With this technique, the question of whether the association between PGA phenotypes and gastric malignancy is primary or secondary may be solved in the near future. In view of the very poor prognosis for gastric cancer, further studies concerning the relationships between gastric cancer, serum pepsinogen levels, and PGA phenotypes or genotypes will hopefully lead to the possibility of an earlier diagnosis for gastric malignancy.
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PMID:Pepsinogens: an update of biochemical, physiological, and clinical aspects. 332 41

We have determined the prevalence of pepsinogen II (PG II) immunoreactive cells in a large series of early and advanced gastric cancers and relationships among PG II-positivity, tumor histologic type, extent of gastric wall invasion, and presence of lymph node metastases. Of the 316 cancers evaluated, 150 (47%) expressed PG II. The prevalence by histologic type was 55% in 146 glandular tumors, 43% in 83 diffuse tumors, 16% in 25 mucoid tumors, and 51% in 59 mixed-type cancers. Two parietal cell cancers and one undifferentiated cancer were PG II-negative. In glandular and diffuse cancers, but not mucoid and mixed tumors, both the extent of gastric wall invasion and incidence of lymph node metastases were associated positively with PG II expression by the primary tumor. In particular, PG II-reactive cells were found significantly more often in advanced than in early diffuse cancers (P less than 0.05) and significantly more often in submucosal early cancers than in intramucosal early cancers (P less than 0.01). The prevalence of PG II expression also was higher significantly in metastatic cancers than in nonmetastatic cancers. This was true for advanced gastric cancers as a whole (P less than 0.01), advanced glandular-type cancer alone (P less than 0.01), advanced glandular- and diffuse- type cancers together (P less than 0.001), and early diffuse-type cancer (P less than 0.05). Only four (3%) of 145 cancers evaluated for pepsinogen I (PG I) were positive, and each also was positive for PG II. The results suggest that the expression of PG II by glandular and diffuse types of gastric cancer may be a marker of increased malignancy.
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PMID:Expression of pepsinogen II in gastric cancer. Its relationship to local invasion and lymph node metastases. 333 59

The determination of serum pepsinogen A (= pepsinogen I) levels is of clinical importance in the study of duodenal ulcer, atrophic gastritis and gastric cancer. In the present study two different quantitative immunological techniques for serum pepsinogen A were compared: a radioimmunoassay (RIA) (Helsinki) and an enzyme-linked immunosorbent assay (ELISA) (Amsterdam). Serum samples of 177 subjects with various gastric diseases were tested in a double blind study. The correlation was excellent (r = 0.954 in the range 0-760 micrograms/l and r = 0.971 in the range 0-100 micrograms/l). The functional relationship between ELISA (x) and RIA (y), determined by weighted model II regression, was y = 1.12x-0.54. Initially the use of goat anti-PGA in the ELISA resulted in falsely high values in about 10% of the individuals. This was caused by circulating antibodies cross-reacting with goat IgG. This artefact was eliminated by pre-incubation of all samples with non-immune goat serum.
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PMID:Enzyme-linked immunosorbent assay and radioimmunoassay of serum pepsinogen A. 355 88

Prospective epidemiologic studies among Hawaiian Japanese men have shown that a serum pepsinogen I (PG I) level below 20 ng/ml is highly specific for extensive intestinal metaplasia of the stomach and for the intestinal type of stomach cancer. The test, however, shows a low level of sensitivity as a predictor of the intestinal type stomach cancer. Since antralization of the corpus, as encountered in Type A atrophic gastritis and late stage Type B gastritis, results in an increase of PG II relative to PG I, we examined the sensitivity and specificity of the PG I/PG II ratio as a predictor of gastric cancer. Using a cut-off point of 2.0 in the ratio to separate subjects at high and low risk for stomach cancer, we found a modest improvement in the level of sensitivity with a small decrease in specificity. Abnormally low PG I levels and PG I/PG II ratios were associated mainly with advanced stages of the intestinal type of cancer and therefore, are not useful screening tests to identify early cases of gastric cancer. The use of the PG I/PG II ratio resulted in a modest improvement in the level of sensitivity with a small decrease in specificity.
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PMID:Serum pepsinogens I and II and stomach cancer. 356 23

The serum level of pepsinogen I (PG I) and pepsinogen II (PG II), and the PG I/PG II ratio were compared with the surface area of the fundic mucosa, as determined endoscopically by the Congo red staining method. Reduction in the area of the fundic mucosa due to gastritis was associated with stepwise reduction in the PG I levels and the PG I/PG II ratios. Reduction in the area of the fundic mucosa was also associated with decreases in the basal acid output, maximal acid output (MAO), the basal pepsin output and the stimulated pepsin output. The best sensitivity and specificity levels for the diagnosis of normal mucosa and severe gastritis were obtained with the PG I/PG II ratio and the MAO. A retrospective study of 58 patients with gastric cancer and 162 cancer-free patients showed that a PG I/PG II ratio identified 86.2% of all carcinomas and 87.5% of early carcinomas. Although this test gave a positive rate of 36% among the cancer-susceptible age group controls, its use would lower the cost of mass screening by targeting a smaller test population.
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PMID:Serum pepsinogens as a screening test of extensive chronic gastritis. 359 51

A survey was conducted of 513 men aged 65 74 years living in two British towns with high and low stomach cancer death-rates. The prevalence of severe atrophic gastritis (defined as a serum pepsinogen I less than 20 micrograms l-1) was significantly higher in the high-risk than in the low-risk town (14.5% and 7.7% respectively); it also tended to be higher in the manual workers, who are known to have a greater risk of stomach cancer than non-manual workers. The manual workers in the high-risk town were particularly likely to have had a partial gastrectomy. Plasma ascorbate concentration and fruit intake were lower in the high-risk area and lower social classes, suggesting a poorer vitamin C status. There was, however, no direct relationship between ascorbate concentration and the presence of severe atrophic gastritis. These findings are consistent with the hypothesis that risk of stomach cancer is determined in two stages--a long-term effect, producing atrophic gastritis; and a short-term effect in which vitamin C is protective.
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PMID:Atrophic gastritis and vitamin C status in two towns with different stomach cancer death-rates. 366 68

One hundred and forty-four patients with apparently benign gastric ulcer were endoscopically followed up in order to evaluate the outcome of the lesion. Particular attention was given to: (a) detect possible delay in diagnosing gastric cancer; (b) ascertain the frequency of association with epithelial dysplasia; (c) establish the role of markers, such as serum pepsinogen group I (PGI), and gastric juice CEA in predicting gastric ulcer evolution. Endoscopic and bioptic check-ups were carried out during the first year at 3, 6 and 12 months after endoscopic healing of the ulcer, and then at every symptomatic recurrence. Ten patients (6.9%) were found to present histological evidence of malignancy (within 3 months in six cases, between 6 and 12 months in three cases, and after 41 months in the rest). Four cases were early gastric cancers, and six had shown dysplastic changes of the mucosa at the edge or scar of the ulcer. Serum PGI levels were not significantly different in gastric cancer patients, while gastric juice CEA levels were sharply increased compared to those of gastric ulcer patients: nine out of ten patients had values above normal range. These data suggest that: (a) there may be some delay in diagnosing gastric carcinoma, and gastric ulcer patients should be controlled routinely more than once; (b) the presence of dysplasia indicates the need for prolonged follow-up, because of the high risk of association with or evolution into gastric cancer, and because of the higher number of early gastric cancer detections that this protocol allows; (c) further support in monitoring patients "at risk" may be afforded by gastric juice CEA determination.
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PMID:Early and advanced gastric cancer during follow-up of apparently benign gastric ulcer: significance of the presence of epithelial dysplasia. 369 32

A hybridoma monoclonal antibody against human pepsinogen I was used to develop an enzyme-linked immunosorbent assay for pepsinogen I in serum. In the two-step competitive procedure using antimouse immunoglobulin F(ab')2 fragment coupled to alkaline phosphatase, the measurable assay range was 8-256 micrograms/l. No cross-reactivity with rat pepsinogen 1, human pepsinogen II, gastrin I, bombesin, somatostatin and peptide YY was shown. However, there was slight cross-reactivity (0.09%) with porcine pepsinogen. The coefficients of variation within and between series were 7.6% and 13.0%. This enzyme-linked immunosorbent assay for serum pepsinogen I correlated positively with radioimmunoassay (r = 0.87, n = 92). The concentration range of serum pepsinogen I in 354 healthy controls was 15-100 micrograms/l with a lognormal distribution. Serum pepsinogen I levels were significantly higher in the subjects who developed active duodenal ulcer or active gastric ulcer, but significantly lower in those who had gastric cancer, than in control subjects.
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PMID:Enzyme-linked immunosorbent assay of serum pepsinogen I. 380 50

Previous studies in rats have shown that stomach carcinogens cause a decrease of total pepsinogen content and a decrease of the fastest pepsinogen isozymogen in gastric mucosa before the appearance of carcinoma. In man the presence of Pg 5, and in particular a strong Pg 5, appears to be associated with gastric cancer. Low serum PG I levels were found in patients with gastric cancer, atrophic gastritis, intestinal metaplasia and gastric polyp. In this chapter we review the literature and report our results of PG I isozymogen and serum PG I determinations in 500 patients with various gastric disorders. It is concluded that premalignant changes of the stomach are associated with the presence of a strong Pg 5 isozymogen and with a low serum PG I level.
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PMID:Qualitative and quantitative determinations of pepsinogen I in gastric cancer and premalignant changes of the stomach. 388 51


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