Showing papers by "Yang Li published in 2003"

Primary investigation on the changing mode of plasma specific IgG antibody in SARS patients and their physicians and nurses

Abstract: Objectives To primarily investigate the changing mode of anti-SARS coronavirus IgG antibody in clinically diagnosed SARS patients and the possibility of subclinical infection in physicians and nurses through close association with SARS patients. Methods The plasma levels of anti-SARS coronavirus IgG antibody of 57 normal subjects, 127 physicians and nurses worked in SARS wards for one month and 73 SARS patients with different course of SARS were measured by enzyme linked immunosorbent assay. Results Plasma anti-SARS coronavirus IgG antibody was not detected in normal subjects and the clinical personnel. After 0-7 days, 8-10 days, 11-14 days, 15-20 days of onset of disease, the positive rates were 0.33%, 52%, 86% respectively, and the general positive rate was 61%. Conclusion The specificity and sensitivity of ELISA to detect plasma anti-SARS IgG antibody were satisfactory. Cases with positive reaction could be diagnosed as patients already infected by the virus. The specific IgG antibody didn't emerge in some patients in the early stage of the disease, and the negative results didn't indicate that they were not infected. And follow-up investigation should be made in those patients. Unlike common epidemic infectious diseases, SARS probably hadn't the potentiality of subclinical infection.

Alcohol-induced regulation of adipogenic and osteogenic genes expression of marrow stromal cells

Abstract: Objective The mechanism of osteonecrosis induced by alcohol was not clear, lipoidosis in bone cell could be one of reasons to cause osteonecrosis. The study was to observe the effect of alcohol on the adipocyte-specific gene, 422 (aP2), and osteoblastic gene, type-I collagen of marrow stromal cells in vitro experimentally. Methods The primary marrow stromal cells of the femur of 6 to 8 weeks mouse were procured and cultured in DMEM culture fluids, and the samples were isolated after adherent growth culture in vitro. The cells were divided into two groups, one of which was experimental group treated with 0.09 mol/L alcohol added with the culture fluids once for two days; another one was control group. The mixed culture discontinued 10 days later, the cells were collected after the combined handling of 0.22% EDTA and 0.25% trypsinase, and the concentration of the cell suspension was adjusted to 1×109/L. A volume of 10 μL of the cells suspension was dropped on the nitric cellulose membrane. The expression level of 422(aP2) and type-I collagen mRNA in the cells were investigated by means of intact cell RNA dot blot hybridization. Results The expression scanning value of the dot blot hybridization of 422(aP2)mRNA was 7 207.8±331.3 in the experimental group, that were as 11 times as that in the control group( 652.2±62.6), the difference was statistical significant between the two groups (P0.001). However, the expression value of type-I collagen mRNA contents in the experimental group was 3 567.3±300.9, and the value of type-I collagen mRNA contents in the control group was 7 487.0±488.4 and significantly higher than that of the experimental group, the difference was significant (P0.001). Conclusion The gene analysis of the research suggest that alcohol could induce marrow stromal cells to differentiate into adipocytes and inhibit osteogenic differentiation of the cells by regulating gene expression, which may be a important reason to cause lipoidosis in bone marrow and deficiency of bone repair in alcohol-induced osteinecrosis.

Homocysteine increases the synthesis of adrenomedullin in vascular fibroblasts of rats

Abstract: The effect of homocysteine (Hcy) on the synthesis of adrenomedullin (ADM) was examined in vascular fibroblasts of rats to explore the possible activity of ADM in cardiovascular diseases. ADM from cultured vascular fibroblasts was measured by Radioimmunoassay (RIA) and was characterized by reverse phase high performance liquid chromatography. ADM mRNA in the fibroblasts was quantitated by competitive RT-PCR. The synthesis of ADM from vascular fibroblasts was increased by Hcy in a concentration dependent manner. ADM content in cultured medium increased by 68%–150% (P < 0.01, as compared to the control) when the fibroblasts were incubated in 50 –200 μmol · L−1 Hey for 12 h, and the content increased by 55%–98% (P < 0.01) if the incubation lasted for 24 h. Hydrogen peroxide treatment also increased the synthesis of ADM and it promoted ADM synthesis synergetically with Hcy. The changes of ADM content were partially or completely inhibited by the antioxidant N-acetylcysteine (NAC) treatment. Hcy induced the increase of ADM mRNA and the amount of ADM mRNA was increased by 78% as compared with control (P < 0.05). NAC almost completely inhibited the increase of ADM mRNA induced by Hcy. In conclusion, Hcy treatment up-regulated the expression of ADM gene and increased the synthesis of ADM in vascular fibroblasts. Oxidative stress may be involved in the processes of the ADM changes induce by Hcy.