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Objective To study whether physiological and psychological stresses during parachuting jumps may result in biochemical changes of plasma in parachutists. Method Differences in the levels of hormones (cortisol, growth hormone, insulin, pancreatic glucagon, endothelin, angiotonin I and II, aldosterone), activities of enzymes (superoxide dismutase, glutathione peroxidase, glutathione S transferase), levels of the free radical damage indicator malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and the main heat stress protein, HSP70,in the plasma and serum were investigated in control (non-parachuting) and parachuting paratroops. Result Significantly higher levels of serum hormones such as growth hormone, insulin, angiotonin I, renin activities, as well as MDA and plasma TNF-α and HSP70 were observed in the parachuting group. Conclusion Whether these changes can potentially serve as useful biomarkers to assess possible abnormal stress in parachutists and to evaluate the health condition and to select parachutists remains to be further studied.
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AIM: To observe the effects of high-dose hepatitis B surface antigen (HBsAg) vaccine on cellular immune response in BALB/C mice. METHODS: The mice were immunilized separately with low-dose and high-dose HBsAg vaccine by intramuscular injection two times. The specific proliferative activities of T lymphocytes were measured by [ 3H]-TdR incorporation assay. IL-2 as well as IFN-? levels in the culture supernatant of T cells and anti-HBs IgG2a lever in sera were detected by enzyme-linked immunoabsorbent assay. RESULTS: After first vaccination with high-dose HBsAg, the proliferative activities of T cells in the experimental group were significantly stronger, both levels of IL-2 and IFN-? were markedly higher than that in the control group and the percentage of mice to produce serum anti-HBs IgG2a was significantly higher compared to that of mice immunilized by low-dose HBsAg. All data in experimental groups were further increased after second dose of vaccine. CONCLUSION: Vaccination of mice with high-dose HBsAg can induce cellular immune responses tended to Th1(T helper 1 subset) response.
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Objective To study the cellular immune response to a large-dose of HBsAg vaccine in transgenic (Tg) mice. Method After the Tg mice was immunized with HBsAg vaccine, the number of dentritic cells (DC), the level of proliferation of T-lymphocytes, and the production of IL-2 and IFN-?were determined. Results The percentage of cells positive for common stimulating factors CD80, CD86, and I-E k were significantly higher than that of the control group (P