Bactericidal/permeability-increasing protein originates in both the testis and the epididymis and localizes in mouse spermatozoa

Bactericidal/permeability-increasing protein （BPI） is an endogenous antibiotic protein with activity against gram-negative bacteria. In the present study, we examined the expression of BPI in postnatal mouse testes and epididymides as well as the subcellular localization within epididymal spermatozoa. Our results showed that, BPI mRNA was expressed in testis and epididymis independently. Throughout the epididymis, the BPI protein level gradually decreased in the epididymal epithelium in a spatial manner, specialized within the cytoplasm of clear cells in the cauda part. We detected BPI proteins in intact acrosome, implying its testicular origin; on the other hand, after the acrosome reaction, BPI proteins were observed dispersed across the entire sperm head, especially enriched at the equatorial segment. Our findings suggested a dual origin of the BPI that generated both in the testis and epididymis, and associated with mouse spermatozoa. BPI protein might be involved in the dynamics modification of the sperm plasma membrane and also the fertilization process.

Protective effects of bactericidal/permeability-increasing protein onrats after endotoxic shock

objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. coli 026:B6 LPS was injected at a dosage of 12. 5 mg/kg through the artery to reproduce endo toxic shock. BPIP at a dosage of 5 mg/kg (BPIP-treated group) or equal volume of normal saline (control group) were injected immediately after the injection of LPS. Results: ①Survival time of the shocked animals was prolonged and the 24 h survival rate was also significantly increased in BPIP-treated group as compared with the control group. ②The mean arterial pressure, left intraventricular systolic pressure, isovolemic ven tricular pressure and ±dp/dtmax. were significantly higher in BPIP-treated group than in control group. ③ Plasma levels of glutamic-pyruvic transaminase and urea nitrogen were markedly higher but those of endotox in and TNFα were lower in BPIP-treated group than in control group. Conclusion: BPIP can exert significant protective effects on cardiac, hepatic and renal functions in rats after endotoxic shock, indicating that BPIP might be a good choice in treatment of sepsis/septic shock.

Stress-unloading and gas migration improvement mechanism in the soft and hard interbedded coal seam using directional hydraulic flushing technology

To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its gas migration performance.In this research,a directional hydraulic flushing(DHF)technology was carried out.The stress-unloading and gas migration improvement mechanism was analyzed through numerical simulation,and systematic engineering tests were conducted to verify the gas drainage effect.The results show that the improvement of gas migration performance in the SHI coal seam is caused by a combined effect of seepage-improving and diffusion-improving.After DHF,stress-unloading and plastic failure could be achieved both in the soft coal(SC)sublayer and in the hard coal(HC)sublayer.However,the gas diffusion capacity improves significantly in the SC sublayer,while the gas seepage capacity improves notably in the HC sublayer.Meanwhile,the stress-unloading and gas migration improvement effect improves with the flushing radius and the thickness of the SC sublayer.Besides,after adopting the DHF technology,the gas drainage effect improved markedly.The borehole number dropped by 49%,the gas drainage ratio increased from 26.0%to 48.2%,and the average coal roadway excavation speed increased from 2.4 to 5.6 m/d.