ABSTRACT
AIM To investigate the role of serine/threonine protein phosphatases 1 and 2A (PP1/2A) in regulation of cell signal transduction involved in the tolerance of human umbilical vein endothelial cells (HUVEC) to hypoxia. METHODS HUVEC tolerance was established by hypoxic preconditioning. The tolerance of HUVEC was evaluated by the cell survival rate, lactic dehydrogenase (LDH) releasing and total antagonistic-oxidative capability (T-AOC). Subcellular localization of nuclear factor E2-related factor 2 (Nrf2) was determined by immunocytochemistry combined with Western blot. The expression of stress protein of heme oxygenase-1 (HO-1) was measured by Western blot. RESULTS Hypoxia 90 min decreased the survival rate and T-AOC of HUVEC significantly, increased the release of LDH in cultured HUVEC. Compared with the hypoxic group, hypoxic preconditioning (4, 8 and 24 h after hypoxia 10 min) up-regulated the tolerance against hypoxia in HUVEC, the survival rate of HUVEC and T-AOC increased and the release of LDH down-regulated when insulted with hypoxia (90 min) in HUVEC. Hypoxic preconditioning established the translocation of Nrf2 from cytoplasm to nucleus and up-regulated the expression of downstream protein HO-1. Pretreatment with okadaic acid (40 nmol·L-1), a powerful inhibitor of PP1/2A, for 10 min in hypoxic preconditioning HUVEC partly inhibited the translocation of Nrf2 from cytoplasm to nucleus and the expression of HO-1, abolished the tolerance of HUVEC established by hypoxic preconditioning. CONCLUSION PP1/2A at least partly take part in Regulation of translocation of Nrf2 and expression of HO-1, with is associated with the tolerance of HUVEC established by hypoxic preconditioning.
ABSTRACT
Objective To research and develop a kind of puncture needle depth -controlled device. Methods Based on mechanical design principle, and with stainless steel and plexiglass as materials, the puncture needle depth -controlled device is composed of syringe, needle guard, pin pusher, scale gauge, depth-controlled nut, and locking screw and pedestal hood. Results The puncture needle depth-controlled device is suitable for different kinds of puncture needles and syringe needles, and has many advantages including operation labor -saving, controlling depth, diminishing contamination and infection, avoiding needle guard slippage and needle bending. The operation can be implemented in one minute. Conclusion The kind of puncture needle depth-controlled device is developed successfully and as new first-aid equipment is provided for war wounds or accidents scene rescue.
ABSTRACT
AIM: To study the effects of hypertonic NaCl-NaAc on microcirculation in hemorrhage-shocked rats.METHODS: SD rats were randomized into three groups of 7 5% NaCl(hypertonic saline, HS),5% NaCl-3 5% NaAc(hypertonic sodium acetate, HSA) and 0 9% NaCl(normal saline, NS) 4 mL/kg HS,HSA or NS was given intravenously following hemorrhagic shock The microcirculation of spinotrapezius muscle was observed RESULTS: HS increased mean aortic pressure more significant than HSA Variables including arteriolar and venular diameter,velocity and volumetric flow rate and open capillaries were increased and erythrocyte aggregation was decreased in 5 min after resuscitation with both HS and HSA solutions 5 min later,variables were deteriorated in HS group After local treatment, arteriolar and venular diameters were dilated significantly in HSA group CONCLUSION:HSA had superior effects to HS in improving microcirculation of hemorrhage-shocked rats