原代培养海马神经元周期素依赖性蛋白激酶5及其活性在低氧环境中的变化

目的:观察低氧对原代培养海马神经元存活力、周期素依赖性蛋白激酶5蛋白表达及其活性变化的影响。方法:实验于2005-01/12在解放军第二军医大学实验动物中心完成。取孕14～18dSD胎鼠的海马细胞进行原代培养,培养8～10d的细胞用于实验。取培养稳定阶段已分化成熟的大鼠海马神经元至低氧环境,继续培养12,24,36h,微孔酶标仪590nm处暗室内测定神经元存活力,免疫印迹测定周期素依赖性蛋白激酶5蛋白表达及其活性改变,每个时间点重复3次。结果:与常氧组比较,低氧组从继续培养12h起神经元存活力明显下降[(1.01±0.14),(0.77±0.15);(0.98±0.12),(0.68±0.11);(0.95±0.11),(0.61±0.08);P<0.01],周期素依赖性蛋白激酶5蛋白表达水平下降[(1.67±0.19),(0.82±0.08);(1.54±0.13),(0.75±0.06);(1.49±0.13),(0.70±0.11);P<0.01],活性明显增加[(1.76,3.56);(1.84,4.29);(1.95,6.04);P<0.01]。结论:低氧环境可导致神经元损伤,与周期素依赖性蛋白激酶5过度激活有关。     

YC-1, a novel activator of platelet guanylate cyclase

YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole] inhibited the aggregation of and ATP release from washed rabbit platelets induced by arachidonic acid (AA), collagen, U46619, platelet-activating factor (PAF), and thrombin in a concentration-dependent manner. YC-1 also disaggregated the clumped platelets caused by these inducers. The thromboxane B2 formation caused by collagen, PAF, and thrombin was inhibited by concentrations of YC-1 that did not affect formation of thromboxane B2 and prostaglandin D2 caused by AA. YC-1 suppressed the increase of intracellular Ca2+ concentration and generation of inositol 1,4,5-trisphosphate caused by these five aggregation inducers. Both the cAMP and cGMP contents of platelets were increased by YC-1 in a concentration- and time-dependent manner. Like sodium nitroprusside, YC- 1 potentiated formation of cAMP caused by prostaglandin E1 but not that by 3-isobutyl-1-methylxanthine. Adenylate cyclase and cAMP phosphodiesterase activities were not altered by YC-1. Activity of cGMP phosphodiesterase was unaffected by YC-1. Activities of guanylate cyclase in platelet homogenate and cytosolic fraction were activated by YC-1, whereas particulate guanylate cyclase activity was unaffected. The antiplatelet effect of sodium nitroprusside but not that of YC-1 was blocked by hemoglobin and potentiated by superoxide dismutase. After intraperitoneal administration for 30 minutes, YC-1 prolonged the tail bleeding time of conscious mice. These data indicate that YC-1 is a direct soluble guanylate cyclase activator in rabbit platelets. It may also possess antithrombotic potential in vivo.     

Attention,awareness, and the right temporoparietal junction

The attention schema theory posits a specific relationship between subjective awareness and attention, in which awareness is the control model that the brain uses to aid in the endogenous control of attention. In previous experiments, we developed a behavioral paradigm in human subjects to manipulate awareness and attention. The paradigm involved a visual cue that could be used to guide attention to a target stimulus. In task 1, subjects were aware of the cue, but not aware that it provided information about the target. The cue measurably drew exogenous attention to itself. In addition, implicitly, the subjects’ endogenous attention mechanism used the cue to help shift attention to the target. In task 2, subjects were no longer aware of the cue. The cue still measurably drew exogenous attention to itself, yet without awareness of the cue, the subjects’ endogenous control mechanism was no longer able to use the cue to control attention. Thus, the control of attention depended on awareness. Here, we tested the two tasks while scanning brain activity in human volunteers. We predicted that the right temporoparietal junction (TPJ) would be active in relation to the process in which awareness helps control attention. This prediction was confirmed. The right TPJ was active in relation to the effect of the cue on attention in task 1; it was not measurably active in task 2. The difference was significant. In our interpretation, the right TPJ is involved in an interaction in which awareness permits the control of attention.     

肝动脉栓塞米托蒽醌乙基纤维素微球的研究

利用正交实验设计法,优选适用于肝动脉栓塞的米托蒽醌乙基纤维素微球制备条件和工艺;采用动态透析法研究了该微球的体外释药规律;根据混悬液的稳定性理论,优选并制备了适于临床肝动脉介导栓塞使用的米托蒽醌乙基纤维素微球混悬注射液。结果表明∶在优化工艺条件下制得的米托蒽醌乙基纤维素微球外形圆整,球径在40～200μm范围内的占总数的91.9%,平均球径为110.24±38.19μm;包封率为55.6%;载药量为12.5%;体外释药符合单指数模型,释药方程为lg(Y_∞-Y)=-0.116t-1.198×10^-3(γ=0.9992,t₅₀=2.6h);其混悬液适于临床应用。用狗进行的实验表明肝血药浓度高,平均驻留时间比注射剂长2.45倍。     

注射用避孕药对纤溶酶原活化物抑制因子活性影响的研究

观察９４名妇女使用Ｍｅｓｉｇｙｎａａｋｇ Ｃｙｃｌｏｆｅｍ ９ｍｏ后其血浆溶酶原活的抑制因子（ＰＡＩ）的活性变化，并与口服低剂量避孕药的妇女作比较。结果显示注射用药的妇女ＰＡＩ在用药期间略有升高，但变化处在正常范围内，且停药３个月后恢复至用药前水平，这些改变与口服用药的妇女相比较没有统计学意义。说明Ｍｅｓｉｇｙｎａ和Ｃｙｃｌｏｆｅｍｗ作为生育控制是安全的。     

宫腔镜诊治宫内病变166例

1 临床资料 2003-03/2004-08我院异常子宫出血及婚后不孕患者,经宫腔镜检查发现宫内病变者166例,年龄24～57岁,异常子宫出血时间0.5～10 a.     

Immunological regulation of experimental cutaneous leishmaniasis. IV. Prophylactic effect of sublethal irradiation as a result of abrogation of suppressor T cell generation in mice genetically susceptible to leishmania tropica

The overwhelming susceptibility of BALB/c mice to infection with Leishmania tropica can be substantially reversed by immediately prior sub-lethal irradiation. This is related to radiation dosage, and at 550 rad, causes 60 percent complete cures and only 19 percent (instead of 100 percent) incidence of progressive disease. Irradiation 10 d before infection is only weakly prophylactic, whereas 10 d after is without effect. Control of lesion development is only apparent after the first 30 d, coincident with the analogous onset previously found in resistant strains and adult thymectomized, x-irradiated, bone marrow-reconstituted BALB/c mice. Instead of the specific suppression of DTH characteristic of L. tropica infection in the BALB/c strain, healed irradiated mice express strong anti-leishmanial DTH reactivity and resistance to reinfection. T cells from these mice transfer DTH reactivity which is suppressed by admixture with cells from nonhealed, nonreactive donors. Irradiated BALB/c mice again develop inexorable disease progression, after its transient arrest, when they are reconstituted with normal T cells. When the T cells are derived from uncontrollably-infected donors, the susceptibility regained is indistinguishable from that of normal mice. B cells do not modify the prophylactic effect of 550 rad, whereas T cells from healed mice confer strong protective immunity throughout the initial phase. Regression or progression of disease correlates completely with DTH reactivity in all these groups. Although BALB/c mice express an extreme level of genetic susceptibility to L. tropica infection, they are nevertheless capable of mounting a curative cell mediated immune response. That this is ineffective during pathogenesis of the disease was previously associated correlatively with potent specific suppressor T cell generation, which is now shown to be preventable by prior irradiation. Most important, however, a causal role for these cells in vivo has been demonstrated directly by reconstitution.     

Diffusion flame-derived fine particulate matters doped with iron caused genotoxicity in B6C3F1 mice

Potential genotoxic effects of diffusion flame-derived particulate matters (PMs), known to cause various adverse health problems, doped with iron, one of the representative heavy metals frequently found in the atmosphere, were examined. B6C3F1 mice were exposed to PMs [chamber 1 (low), 100; chamber 2 (middle), 200; and chamber 3 (high), 400 microg/m3] for 6 h/day, 5 days/week for one, two and four weeks in 1.5 m3 whole-body inhalation chambers. Our diffusion flame system produced 94.8 and 5.2% fine PM2.5 and PM10, respectively, with 89% of PM2.5 sized between 0.1 and 0.2 microm. Two cytogenetic endpoints were investigated through chromosomal aberration and supravital micronucleus (SMN) assays. Frequencies of cells with chromosome aberration (%) were observed in time- and concentration-dependent manners except in one-week exposure group, as also observed in SMN study. Generally, noniron flame induced less chromosome aberration than iron-doped flame, an indication that iron particles could potentiate urban PM toxicity. The above results indicate our diffusion flame system generated genotoxic fine PMs, whose effects were potentiated by organometallic particles such as iron. Our system can provide reliable PM models for studying the toxicity of urban fine PMs applicable for risk assessment.