排序方式: 共有157条查询结果,搜索用时 15 毫秒
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Differential north to south gastric cancer-duodenal ulcer gradient in China. China Ulcer Study Group
BC Wong CK Ching SK Lam ZL Li BW Chen YN Li HJ Liu JB Liu BE Wang SZ Yuan CP Xu XH Hou AT Zhang ZT Zheng 《Canadian Metallurgical Quarterly》1998,13(10):1050-1057
There are suggestions that duodenal ulcer protects individuals from gastric cancer and that rice is ulcerogenic while wheat is gastro-protective. We aimed to examine the relationship of gastric cancer, duodenal and gastric ulcers in different geographical regions in China and identified dietary risk factors for duodenal ulcer and gastric cancer. The prevalence of peptic ulcer and gastric cancer among symptomatic patients in eight major cities, four each from the north and the south representing all the six defined regions of China were studied. Endoscopy and case records over a 10 year period were reviewed and cases of confirmed duodenal and gastric ulcer and gastric cancer, together with the total number of endoscopies performed per year, were recorded. Rates were expressed as cases/1000 endoscopies. Results were compared to another epidemiological study on diet and mortality in the same regions in China conducted at the same time. Duodenal ulcer rates were 2.4-fold higher in southern China than northern China, whereas gastric cancer rates were 1.6-fold higher in the north than in the south. Correlation studies showed for the first time an inverse linear relationship between the gastric cancer rates and the duodenal ulcer rates (r=-0.8076, P=0.015), as well as the duodenal ulcer: gastric ulcer ratios (r=-0.9133, P=0.002). Gastric ulcer rates were higher in southern China but did not correlate with the gastric cancer rates (r=0.1455, P=0.731). Duodenal ulcer rates were found to be related to daily rice intake (r=0.8554, P=0.029) and inversely related to daily wheat flour intake (r=-0.8472, P=0.033). Gastric cancer rates were not related to any dietary risk factors tested. We concluded there was an inverse relationship between gastric cancer rates and duodenal ulcer rates. Although duodenal ulceration and gastric cancer are both linked to Helicobacter pylori infection, the findings of this study indicate independent additional aetiological factors for the pathogenesis of these conditions. Dietary factors such as rice or wheat intake may play a role. 相似文献
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SZ Goldhaber 《Canadian Metallurgical Quarterly》1997,30(5):1172-1173
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SZ Fan TS Lee LK Chen LH Lee YL Chu J Tu CC Liu 《Canadian Metallurgical Quarterly》1995,33(4):233-236
SAPHO syndrome is characterized by osteoarticular involvement of ventral chest wall in the form of sternocostoclavicular osteoarthritis and hyperostosis and skin changes such as palmoplantar pustulosis and acne. Occasionally, psoriatic lesions and sacroiliitis are observed. However, despite the higher frequency of psoriasis in this syndrome, its inclusion in psoriatic arthropathy spectrum is not clearly established. The authors report three cases of SAPHO syndrome in psoriatic patients commenting on the difficulty in differentiating this entity from psoriatic arthritis as well as its relationship with seronegative spondyloarthropathies. This disease has been described mainly in Japan and only a few cases of this disease have been reported in the European or American literature. 相似文献
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Helicobacter pylori (HP) infection has been shown to increase gastric mucosal interleukin 8 (IL-8) expression, and whether HP or its toxin induces endothelial cell IL-8 expression is unknown. We aimed to compare the IL-8 expression in endothelial cells after stimulation with HP toxin, tumor necrosis factor alpha (TNF-alpha), and lipopolysaccharide (LPS) and to study their signal pathways. HP or its toxin induced significant IL-8 expression in endothelial cells. HP toxin, TNF-alpha, and LPS also showed a time- and dose-dependent increase in IL-8 expression over the control. Both protein kinase C (PKC) and protein kinase A (PKA) inhibitors had no effect on IL-8 response to these stimuli. Protein tyrosine kinase (PTK) inhibitor genistein at concentrations of 150, 300, and 450 microM dose-dependently reduced LPS- and TNF-alpha-induced IL-8 expression by 29.43, 43.8, and 47.3% and 20.5, 49.9, and 61.8% respectively, whereas HP toxin-induced IL-8 secretion could only be reduced at 450 microM by 35.7%. Geldanamycin, a more potent PTK inhibitor, at doses of 0.5, 1, and 2 microM dose-dependently reduced HP toxin induced endothelial cell IL-8 expression by 24.8, 26, and 44.3% respectively. It is concluded that HP and its toxin can increase IL-8 expression in endothelial cells, and the expression of IL-8 elicited by HP toxin, TNF-alpha, and LPS is partially dependent on PTK but not PKA or PKC activation. 相似文献
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Threshold exposures for producing intestinal hemorrhage in mice were determined using focused sources operating at 0.7, 1.1, 2.4 and 3.6 MHz. The choice of pulse length (10 microseconds) and pulse repetition frequency (100 Hz) made the exposures diagnostically relevant, while at the same time, minimized possible thermal contributions to the mechanism of action of the ultrasound. Each animal was irradiated at four to five abdominal sites for 5 min per site. Suprathreshold lesions ranged from small petechiae to hemorrhagic regions extending 4 mm or more along the intestine, depending upon the exposure levels. Higher frequencies were less effective in producing intestinal hemorrhage than lower frequencies. Thermocouple measurements of temperature rise in the intestine during ultrasound exposure revealed temperature increments between 1 degrees and 2 degrees C at the highest exposure levels. The frequency dependence of the production of intestinal hemorrhage together with the observed limited heating is consistent with a cavitation-related mechanism of action of pulsed ultrasound. 相似文献
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Two strategies for crossbreeding of indigenous and exotic cattle for milk production in the tropics, viz. rotational crossing and formation of a composite breed, have been compared. Genetic considerations suggest that rotational crossing would lead to somewhat better dairy performance, mainly because of more heterozygosity. Predictions based on the performance of adjacent genetic groups as obtained from a comprehensive literature review point in the same direction. Rotational crossbreeding depends on a continuous introduction of bulls of both parental breeds. The herd will consist of 2 (or more) genetic groups, which might be inconvenient for breeding arrangements, but provides more flexibility. The system requires good organisation and is most suitable in large farms. In small scale dairying the composite breed strategy is the most practical approach to dairy cattle breeding in the tropics. 相似文献
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EW Carney AM Hoberman DR Farmer RW Kapp AI Nikiforov M Bernstein ME Hurtt WJ Breslin SZ Cagen GP Daston 《Canadian Metallurgical Quarterly》1997,11(6):879-892
Recent concerns about the potential of certain chemicals to modulate estrogen-regulated processes have led to questions as to how chemicals should be tested for such effects. Therefore, AIHC has developed a comprehensive, resource-efficient, and flexible tiered strategy for estrogen modulation (EM) testing. Levels of evaluation include Tier 0, in which exposure, along with alerts based on structure-activity, persistence, bioaccumulation, and other data, are assessed to prioritize chemicals for preliminary testing. In Tier I, short term in vitro, ex vivo, and/or in vivo assays are used to obtain a preliminary indication of EM potential. Among these, an in vivo response assay is considered the most reliable at this time. However, none of these tests are intended for risk assessment, but rather to aid in choosing chemicals for further testing and in guiding the extent of that testing. Tier II is aimed at risk assessment and involves whole animal tests that contain EM-sensitive end points (e.g., two-generation reproduction study). Tier III consists of hypothesis-driven research reserved for situations where targeted research can reduce levels of uncertainty. This tiered approach provides a framework for the strategic and effective application of EM test methods to address specific information needs on a case by case basis. 相似文献