Biomedical subjects

Zhongwu Li

Publications and source records attributed to Zhongwu Li.

4 recordsLinked to original sources

PubMed2006

Local expressions of TGF-beta1, TGF-beta1RI, CTGF, and Smad-7 in Helicobacter pylori-associated gastritis.

OBJECTIVE: Transforming growth-factor (TGF)-beta1 and Smad-7 play important roles in Helicobacter pylori (H. pylori)-associated gastritis. Connective tissue growth factor (CTGF) can facilitate the TGF-beta/Smad signaling by switching off Smad-7. The purpose of this study was to examine the in situ expressions of these cytokines in the gastric antrum with or without H. pylori infection. MATERIAL AND METHODS: Antral specimens from 166 patients (96 M, 70 F, median age 52 years, range 26 to 76 years) were used in this study. H. pylori infection status was determined by histological examination and (UBT) [13C]-urea breath test. Degrees of severity and activity of chronic gastritis were scored for all specimens. Immunohistochemistry was used to demonstrate local expressions of TGF-beta1, TGF-beta1 type 1 receptor (TGF-beta1RI), Smad-7, and CTGF in the gastric antrum. RESULTS: The results demonstrated that mononuclear cells (MNCs) in lamina propria were the major source of these cytokines. The number of MNCs stained with TGF-beta1, TGF-beta1RI, CTGF, and Smad-7 was significantly higher in H. pylori-positive patients than in H. pylori-negative patients. Furthermore, there was a positive correlation between these cytokine-producing MNCs and the severity of chronic gastritis. CONCLUSIONS: H. pylori infection is associated with increased expression of TGF-beta1, TGF-beta1RI, Smad-7, and CTGF in the gastric antrum. Our results also suggest that the feed-back loop consisting of TGF-beta1, Smad-7, and CTGF may play an important role in the pathogenesis of H. pylori-associated gastritis.

Activin Receptors, Type I↗

PubMed2006

[Enrichment and toxicity effect of heavy metals in soil ecosystem].

The study on the heavy metals-polluted soil of Qingshuitang District, Zhuzhou City showed that the main enriched heavy metals in the soil were Cd, Hg, As, Zn, Pb and Cu, among which, the former three had strong biotoxicity while the others had definite toxicity, with the average integrative pollution index being 6.40. The heavy metals enrichment in soil animals increased with increasing pollution degree. Especially for some species of Megascoiecidae, they had a high enrichment of Cd, with the enrichment index being 11.96. The species and quantity of soil animals decreased with increasing Cd concentration. Cd had an obvious biotoxic effect on Megsacoiecidae' s isozyme activity. The heavy metals enrichment in vegetables also increased with increasing pollution degree, but there existed obvious interspecies difference in Cd enrichment.

Arsenic↗

PubMed2002

[Crop productivity model and its application].

Within agricultural ecosystems the interaction between crop and surroundings is quite complicated. In order to know the feedbacks of crop to surroundings in agricultural ecosystem, a research on crop productivity model is becoming important. This paper discussed the backgrounds of the emergency of crop productivity model, thinking that the crop productivity model was a means which could be used to simulate growth process by mathematical ways and computer technology, and analyzed the physiology of crop growth and the correlation between crop and surroundings. At the same time, it discussed four phases of crop productivity model developing, including infancy, youth, adolescent and maturity. Secondly, the paper summarized the crop productivity model's function of agricultural eco-environment protection from three aspects, including scientific research, management of crop, and analysis of agricultural decision, and discussed the disadvantages of crop productivity model. The disadvantages embodied in three facets: 1) though the simple crop productivity model could be used easily in practice, its regional adaptiability was too weak; 2) complicated crop productivity model had too much parameters to obtain, which made it difficult to use in practice; 3) the inconsistency of basic data format in different research areas also made the model's regional adaptability too weak. It's indicated in this paper that the establishment of universal and uniform basic data format is favorable to the extension and application of crop productivity model in other regions. Geographic information system (GIS) was emerged in 1960, which has powerful functions of obtaining, depositing, managing and analyzing spatial data, and is useful to solve the problem of weakly regional adaptability. Meanwhile, friendly interface is favorable to the extension in common users. Finally, the paper discussed the combination of crop productivity model and geographic information system, summarized some researches on friendly interface of crop productivity model, and pointed out that the establishment of universal crop productivity model interface is the focus of the future.

Agriculture↗

PubMed2002

[Effect of organophosphorus pesticide toxicity on soil animal].

The test of organophosphorus pesticide on toxicity of soil animal showed that soil animal is sensitive to organophophorus toxicity, the species and quantities of soil animal treated by four kinds of pesticide are decreased. The species of soil animals was decreased with decreasing common population and rare population, while the amount change of soil animal was associated with the amount change of dominant populations of Acarina and Collembola. Toxicology and toxicity experiment showed that the pesticide has a deadly effect to earthworm, and its toxicity constrained the respiration intensity of big soil animals obviously, which weakened with the increasing pesticide concentration and prolonging poisoning time.

Animals↗