Effect of the stable thromboxane derivative, carbocyclic thromboxane A2, on membrane potential of rat myenteric neurones in culture

The effects of carbocyclic thromboxane A(2) (cTXA(2); 10(-6) mol L(-1)) on membrane potential and cytosolic Ca(2+) concentration were measured with the whole-cell patch-clamp or the fura-2 method, respectively, at rat myenteric ganglia. cTXA(2) caused a hyperpolarization of myenteric neurones from -19.3 +/- 2.5 to -29.3 +/- 2.3 mV. In addition, the eicosanoid potentiated the carbachol-induced depolarization from 4.2 +/- 1.0 mV under control conditions to 11.1 +/- 1.1 mV in the presence of the cTXA(2) (n = 9). The hyperpolarization was abolished by internal application of CsCl (140 mmol L(-1)), a non-selective blocker of K(+) channels, or EGTA (11 mmol L(-1)in the pipette solution), a chelator of intracellular Ca(2+). A similar inhibition was observed in the presence of charybdotoxin (10(-7) mol L(-1)). Fura-2 imaging experiments revealed a cTXA(2)-evoked increase in the intracellular Ca(2+) concentration as indicated by a rise in the fura-2 ratio signal. This response was mediated by a release of Ca(2+) from intracellular stores as sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase blockade with cyclopiazonic acid (5 x 10(-5) mol L(-1)) completely abolished the response to cTXA(2). A similar inhibition was observed after blockade of phospholipase C with U-73122 (10(-5) mol L(-1)). These results suggest an activation of Ca(2+)-activated K(+) channels by cTXA(2) after stimulation of phospholipase C.     

选择性5-HT1A受体拮抗剂WAY-100635抑制帕金森病模型大鼠腹内侧前额叶皮质的神经活动

目的腹内侧前额叶皮质在随意运动的起始和控制、情感以及认知中具有重要作用。然而,黑质-纹状体通路变性后腹内侧前额叶皮质的神经活动和5-HT_(1A)受体的作用仍不清楚。本研究观察了6-羟基多巴胺(6- hydroxydopamine,6-OHDA)损毁黑质致密部(substantia nigra pars compacta,SNc)后大鼠腹内侧前额叶皮质神经活动的变化和体循环给予选择性5-HT_(1A)受体拮抗剂WAY-100635后神经元活动的改变。方法采用在体玻璃微电极细胞外记录方法,记录正常大鼠和SNc单侧损毁大鼠的腹内侧前额叶皮质神经元的活动。结果6-OHDA损毁SNc大鼠的腹内侧前额叶皮质神经元放电频率显著增加,放电形式没有明显改变。体循环给予WAY-100635 (0.1 mg/kg,i.v.)不改变正常大鼠腹内侧前额叶皮质神经元的平均放电频率和放电形式,而显著降低了SNc损毁大鼠前额叶皮质神经元的平均放电频率。结论黑质-纹状体通路的变性可导致腹内侧前额叶皮质神经活动增强,5-HT_(1A)受体拮抗剂WAY-100635可以抑制这种活动增强,提示可能存在腹内侧前额叶皮质5-HT_(1A)受体功能失调。     

Infection dynamics and virus-induced apoptosis in cell culture-based influenza vaccine production—Flow cytometry and mathematical modeling

Cell culture-based influenza vaccine manufacturing is of growing importance. Depending on virus strains, differences in infection dynamics, virus-induced apoptosis, cell lysis and virus yields are observed. Comparatively little is known concerning details of virus–host cell interaction on a cellular level and virus spreading in a population of cells in bioreactors. In this study, the infection of MDCK cells with different influenza A virus strains in lab-scale microcarrier culture was investigated by flow cytometry. Together with the infection status of cells, virus-induced apoptosis was monitored. A mathematical model has been formulated to describe changes in the concentration of uninfected and infected adherent cells, dynamics of virus particle release (infectious virions, hemagglutinin content), and the time course of the percentage composition of the cell population.     

高血压病肠系膜动脉平滑肌细胞端粒酶活性表达的研究

目的 :探讨高血压病动脉平滑肌组织端粒酶活性与高血压的发病关系。方法 :采用PCR -ELISA法检测 30例高血压病患者和 2 0例血压正常者肠系膜动脉平滑肌细胞 (SMC)端粒酶活性。结果 :高血压患者端粒酶阳性表达 2 8例 (93.3% )。血压正常者端粒酶阳性表达 3例 (15 % )。差异非常显著 (P <0 .0 5 )。结论 :高血压病动脉平滑肌细胞端粒酶活性的表达升高 ,可能与高血压发病有关。     

Synaptic and extrasynaptic NMDA receptors: Problems and prospects

This review is devoted to the problem of induction of differently directed NMDA-dependent longterm plasticity in the central nervous system and their transformation into pathological changes. Their hypothetical mechanisms and the corresponding experimental data are discussed. Special attention is paid to the functional characteristics of synaptic and extrasynaptic NR1/NR2A and NR1/NR2B receptors, their different involvement in the spatiotemporal organization of Ca²⁺ signaling, and peculiarities of biochemical reactions of the cell. The possible structural reorganization of NMDA receptors as one of the kinds of plasticity is also analyzed.     

不同剂量orexin2A对麻醉大鼠催醒效果观察

目的研究侧脑室注射不同剂量orexin2A对麻醉大鼠脑电图（electroencephalogram,EEG）、翻正反射消失（loss of righting reflex,LRR）持续时间、共济失调等的影响。方法腹腔注射氯胺酮75mg/kg及咪达唑仑5mg/kg麻醉大鼠后,侧脑室注射不同剂量orexin2A,通过大鼠脑电δ波比例、LRR持续时间及共济失调监测,了解不同剂量orexin2A对麻醉大鼠催醒效果。结果与对照组相比,侧脑室注射orexin2A1nmol后,大鼠脑电δ波、LRR持续时间及共济失调时间,差异无统计学意义（P〉0.05）;侧脑室注射orexin2A4、7、10nmol后,大鼠脑电δ波、LRR持续时间及共济失调时间,差异有统计学意义（t=22.81～36.45,P〈0.01）;高剂量组与超高剂量组比较,差异无统计学意义（P〉0.05）。结论侧脑室注射orexin2A可使麻醉深度变浅,麻醉时间缩短,并可促进麻醉后运动功能恢复,存在一定的量效关系。     

肾移植术后普通环孢素A与环孢素A微乳剂对移植肾功能影响的系统评价

目的评价肾移植术后普通环孢素A与环孢素A微乳剂对受者移植肾功能影响的差异。方法遵循Cochrane肾脏协作组随机对照试验检索策略，检索MEDLINE（1994—2006．3）、EMBASE（1994～2006．3）、中国生物医学文献数据库CBM（1994—2006．3）、Cochrane图书馆（2005年第4期）与肾移植相关的8种中文杂志。采用Revman4．2．7进行Meta分析。结果共有5个随机对照试验纳入研究，包括1671例同种异体尸体肾移植患者。结论肾移植术后使用普通环孢素A与环孢素A微乳剂相比受者移植肾功能无明显差异，但环孢素A微乳剂肾毒性发生率较高。     

Effect of a minor vitamin A deficiency on the course of infection with <Emphasis Type="Italic">Ascaridia galli</Emphasis> (Schrank, 1788) and the resistance of chickens

Summary The effect of vitamin A deficiency was studied in chickens infected with 500 Ascaridia galli eggs and controls. Diet 1 (deficient, 500 IU vitamin A or 172 μg retinol acetate per kg diet), Diet 2 (deficient, 1000 IU vitamin A or 344 μg retinol acetate per kg diet) and Diet 3 (sufficient, 1500 IU vitamin A or 516 μg retinol acetate per kg diet) were assigned to 46 chickens each. Clinical signs, weight gains, livers’ weights, vitamin A levels, worm burdens and parasite eggs’ excretions were recorded. Infected chickens had lower weight gains than the controls fed alike. Chickens given Diet 1 stored lesser vitamin A in liver than those fed Diet 3. Although worm counts in the 3 groups did not differ significantly, chickens fed Diet 1 excreted more A. galli eggs than those fed the 2 other diets. Female worms harboured by chickens fed Diet 1 had higher fecundity at week 5 pi than those of chickens fed Diet 2. Results indicated that Vitamin A is important for poultry in the moderation of the infection with A. galli.