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Biomedical subjects

W C You

Publications and source records attributed to W C You.

35 records · Page 2Linked to original sources
PubMed1994

Serum micronutrients in relation to pre-cancerous gastric lesions.

Serum levels of retinol, beta-carotene, ascorbic acid, alpha-tocopherol, selenium, ferritin, copper, and zinc were assayed for approximately 600 adults aged 35 to 64 with pre-cancerous gastric lesions in an area of China with one of the world's highest rates of stomach cancer. Previous studies have shown that the cancers generally are preceded by chronic atropic gastritis (CAG), intestinal metaplasia (IM) and dysplasia. Concentrations of beta-carotene and ascorbic acid were significantly lower among individuals with IM than among those whose most severe lesion was superficial gastritis or CAG. The associations with IM for these nutrients were strong and independent. In combination, the odds of CAG progressing to IM were only 1/6 as high among those with upper tertile levels of beta-carotene and ascorbic acid as among those with lower tertile levels of both nutrients. The serum levels of beta-carotene and ascorbic acid were similar for individuals having IM with or without accompanying dysplasia. Risk of IM was also somewhat increased among those with low serum ferritin, but no significant effects were observed in multivariate analyses for the other nutrients assayed. The findings point to a major influence of specific nutrient deficits in the mechanisms of gastric carcinogenesis in this high-risk area.

Adult↗
PubMed1994

Familial predisposition to precancerous gastric lesions in a high-risk area of China.

Aggregation of intestinal metaplasia and dysplasia was investigated among families participating in a population-based gastroscopic screening survey in an area of China with one of the world's highest rates of stomach cancer. The prevalence of gastric dysplasia was significantly increased among those with dysplasia among siblings or spouses, but not parents. The odds of dysplasia were nearly doubled if an eldest brother or a spouse was affected. Sibling and spousal associations for intestinal metaplasia were much less pronounced and not statistically significant. The specificity of the findings suggests that familial risk of advanced precancerous lesions (dysplasia) is influenced not only by genetic factors, but also by environmental factors operating in childhood and early adult life.

Adult↗
PubMed1993

Precancerous gastric lesions in a population at high risk of stomach cancer.

A population-based screening for detection of early cancers evaluated the prevalence of precancerous gastric lesions in an area in Shandong province, China, with one of the world's highest rates of stomach cancer. A total of 3433 residents aged 35 to 64 yr received gastroscopical examinations with biopsies taken from standard locations. Chronic atrophic gastritis was nearly universal; less than 2% of the population had biopsies showing entirely normal mucosa or only superficial gastritis. Intestinal metaplasia was the most advanced lesion for 33% and gastric dysplasia for 20%, although the prevalence of each increased significantly with age. Intestinal metaplasia and gastric dysplasia were detected throughout the stomach, but the lesions were more pronounced along the lesser curvature, especially in the angulus and antrum. There was no sex difference in rates of chronic atrophic gastritis, but males had a slightly higher prevalence of intestinal metaplasia, a 1.6-fold increase in dysplasia, and a 3-fold excess of gastric cancer. The data quantify the extensiveness of gastric lesions likely to be involved in the natural history of stomach cancer in this high-risk population.

Adult↗
PubMed1992

Cigarette smoking and other risk factors for progression of precancerous stomach lesions.

BACKGROUND: Stomach cancer is generally thought to evolve through a series of gastric mucosal changes, but the determinants of the precancerous lesions are not well understood. PURPOSE: Our purpose was to assess risk factors for intestinal metaplasia and gastric dysplasia arising from chronic atrophic gastritis in a general population at high risk for stomach cancer. METHODS: A population-based gastroscopic screening of more than 3000 residents was conducted in a county in China with one of the world's highest rates of stomach cancer. Information on the lifestyle and other characteristics of the participants was obtained by interview, and responses were compared between those in whom the most advanced gastric lesion was dysplasia or intestinal metaplasia versus those with chronic atrophic gastritis. RESULTS: Cigarette smoking was found to nearly double the risk of transition to dysplasia and to be a mild risk factor for intestinal metaplasia. Smoking accounted almost entirely for the 55% higher prevalence of dysplasia among men than among women. Risk of transition to dysplasia had a weak association with several dietary factors and was increased among those participants with a family history of stomach cancer and with blood type A. CONCLUSIONS: The findings provide strong evidence for a role of tobacco consumption and offer clues to other environmental and genetic factors involved in the process of gastric carcinogenesis.

Adult↗
PubMed1992

Comparison of the anatomic distribution of stomach cancer and precancerous gastric lesions.

The anatomic distribution of precancerous gastric lesions among 3,400 residents in Linqu, Shandong Province of China, was compared with the anatomic distribution of stomach cancer (SC) among 959 patients in Tokyo, Japan. The incidence of SC is high in both areas, and locations within the stomach of the precancerous and malignant lesions were classified using similar criteria. Chronic atrophic gastritis (CAG) affected 98% of the population in Linqu, with intestinal metaplasia (IM) the most severe diagnosis in 33% and dysplasia (DYS) in 20%. Neither the SC nor precancerous lesions were uniformly distributed in the stomach. Among the DYS 3% were along the greater curvature of the body, 15% along the lesser curvature of the body, 25% in the angulus, 22% along the lesser curvature of the antrum, and 34% elsewhere in the antrum. Among the SC the corresponding percentages were 2, 16, 28, 25 and 29. The similarity to the SC distribution increased gradually from CAG to IM to DYS, providing further evidence for the multistage progression of precancerous gastric lesions.

Adult↗
PubMed1991

Etiological research on gastric cancer and its precursor lesions in Shandong, China.

Research over the past several years in an area of Shandong, China, with one of the world's highest rates of gastric cancer, has yielded clues to the environmental determinants of this tumour. Interviews with 564 gastric cancer patients and 1131 population-based controls revealed increased risks associated with consumption of sour pancakes, a fermented staple unique to the area, in samples of which volatile N-nitrosamines have been detected. Lower risks were found among people who had a higher intake of fresh vegetables, including garlic and other Allium vegetables which contain constituents that can inhibit carcinogenesis by N-nitrosamines and other substances in experimental animals. A pilot study involving assays of urine and gastric juice from 60 individuals in a screening programme showed higher levels of N-nitrosoproline and of cis- and trans-N-nitroso-2-methylthiazolidine 4-carboxylic acid among persons with gastric dysplasia than in either normal controls or those with chronic atrophic gastritis. We are trying to characterize the transition and progression of precursor lesions to gastric cancer and to evaluate the role of dietary variables, nutrients, N-nitroso compounds and other factors in particular stages of the carcinogenic process.

China↗
PubMed1991

[Gastric mucosal lesions and their transition rates in high risk population of gastric cancer].

Endoscopic and pathologic examinations were conducted in a randomly chosen population in a high risk area of gastric cancer, Linqu County, Shandong Province. A high prevalence of chronic atrophic gastritis, intestinal metaplasia and dysplasia was found. Gastric mucosal lesions changed from mild to severe with a decline in transition rate. The prevalence rate of severe dysplasia was close to that of gastric cancer. The study indicates that gastric precancerous lesions are related to malignant changes implying that gastric cancer develops on the damaged gastric mucosa. It is also shown that the progression from chronic atrophic gastritis to dysplasia may take an average of 20 years.

Adult↗
PubMed1989

Allium vegetables and reduced risk of stomach cancer.

Interviews with 564 patients with stomach cancer and 1,131 controls in an area of China where gastric cancer rates are high revealed a significant reduction in gastric cancer risk with increasing consumption of allium vegetables. Persons in the highest quartile of intake experienced only 40% of the risk of those in the lowest. Protective effects were seen for garlic, onions, and other allium foods. Although additional research is needed before etiologic inferences can be made, the findings are consistent with recent reports of tumor inhibition following administration of allium compounds in experimental animals.

Adult↗
PubMed1988

Diet and high risk of stomach cancer in Shandong, China.

A case-control investigation involving interviews with 564 stomach cancer patients and 1131 population-based controls was conducted to evaluate reasons for the exceptionally high rates of stomach cancer in Linqu, a rural county in Shandong Province in northeast China. Daily consumption of sour pancakes, a fermented indigenous staple, was associated with a 30% increase in risk. Risks of stomach cancer were also increased by 2- to 3-fold among persons with prior chronic gastritis or gastric ulcer, by 80% among those with stomach cancer in a family member, by 50% among men who smoked one or more packs of cigarettes/day, by 40% among those who preferred salty foods, and by 50% among families with moldy grain supplies. In contrast, risks tended to decrease in proportion to increasing consumption of fresh vegetables and fruits. This protective effect was more pronounced for vegetables, with those in the highest quartile of intake at less than one-half the risk of those in the lowest. Stomach cancer risks also declined with increasing dietary intake of carotene, vitamin C, and calcium, but not retinol. These findings provide leads to dietary factors that contribute to the high rates in Linqu, where stomach cancer is the leading cause of cancer and has not yet begun to decline as in other parts of the world.

Adult↗
PubMed1987

[Gastric cancer-associated antigen P42].

The corresponding antigen to monoclonal antibody PCI against gastric cancer cells was demonstrated as a protein sensitive to heating and easily degraded by proteinase. By western blotting, it was shown that the molecular weight of the antigen was 42 KD and the antigen was named P42. P42 could be shed into serum-free culture medium of the target cells and its activity be assayed in sera of the gastric cancer patients. Using inhibition test, the levels of P42-like substance in sera were measured. The results indicated that this level in the gastric cancer patients (26.53 +/- 23.11) was markedly higher than that in patients with benign gastric diseases (4.66 +/- 2.67) and controls (2.57 +/- 2.67). It is suggested that P42, a novel gastric cancer-associated antigen, be useful in the mass screening and supplementary in diagnosing gastric cancer.

Antibodies, Monoclonal↗
PubMed1985

A case-control study of stomach cancer in Shandong Province.

Stomach cancer is the leading cause of death from cancer in China. Although the causes of this cancer are unknown, special opportunities exist for the evaluation of etiologic factors in Linqu County in Shandong Province where rates are exceptionally high. We have described here a newly initiated case-control study, which focuses on certain dietary items as risk factors for stomach cancer in Linqu.

China↗
PubMed1983

Possible contribution from epidemiological studies.

The problem of chemically contaminated water supplies are in general terms followed by a description of three examples of water supply problems in China. A large-scale prospective epidemiological study, now in the early planning stages, to be carried out in China is also described.

China↗
PubMedDate not supplied

Epidemiology of precancerous gastric lesions.

Research over the past several decades has revealed that the major subtype of gastric cancer (intestinal gastric cancer) is an end result of a multistage transformation of the gastric mucosa over many years and that this process is mainly determined by environmental factors. Epidemiologic studies on precancerous gastric lesions, including a large population-based study of the natural history and aetiology of precancerous gastric lesions conducted in Shandong, China, are reviewed.

Biomarkers, Tumor↗
PubMedDate not supplied

Fusarium mycotoxins in corn and corn products in a high-risk area for gastric cancer in Shandong Province, China.

Consumption of fermented, but not unfermented, corn pancakes has been linked with elevated stomach cancer mortality rates in rural Linqu County in Shandong Province, China. Previous surveys of fungal contamination of corn in China have detected fumonisins, which are mycotoxins produced by Fusarium moniliforme. To determine whether mycotoxins might account for the increased risk of cancer among those consuming fermented pancakes, we obtained specimens of corn, cornmeal, unfermented and fermented pancake batter, and cooked fermented pancakes from each of 16 households in Linqu County for analysis by the U.S. Department of Agriculture. Fumonisins B1, B2, and B3 were detected (> or = 0.5 microgram/g) in 19, 25, and 6% of the corn specimens, respectively, as well as in various corn products. No type A trichothecenes were detected; however, the type B trichothecenes deoxynivalenol and 15-acetyldeoxynivalenol were detected (> or = 0.5 microgram/g) in 58 and 17% of the corn specimens, respectively, and zearalenone was detected (> or = 0.5 microgram/g) in 15% of the cornmeal specimens. The mycotoxins were detected only at low levels (< 10 micrograms/g), which did not increase with fermentation. These findings do not support the hypothesis that mycotoxin contamination increases the risk of gastric cancer among those who consume fermented Chinese pancakes.

Animals↗
PubMedDate not supplied

Serum pepsinogens in relation to precancerous gastric lesions in a population at high risk for gastric cancer.

Concentrations of serum pepsinogens (PG) I and II were determined for 3252 randomly selected adults who participated in a population-based gastroscopic screening in an area of China with one of the world's highest rates of gastric cancer. PG I and II concentrations in both sexes tended to be higher than reported in other countries, with levels generally higher among males than females. PG I tended to decrease and PG II to increase with age, but the most pronounced associations were between PG I:II ratios and gastric histology. Median PG I:II ratios monotonically declined from 9.1 to 7.2 to 5.7 to 5.4 to 3.8 among those with superficial gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia, and stomach cancer, respectively. The prevalence of dysplasia was nearly 3 times greater among those with PG I:II ratios less than 3 compared with those whose PG I:II ratios were greater than 10. While average levels differed significantly among the histologic groups, the PG I:II ratios were neither sensitive nor specific markers of an individual's likelihood of advanced gastric lesions in this population.

Adult↗