Effect of a neuronal sodium channel blocker on magnetic resonance derived indices of brain water content during global cerebral ischemia

Diffusion-weighted magnetic resonance imaging (DWI) with calculation of the apparent diffusion coefficient (ADC) of water is a widely used noninvasive method to measure movement of water from the extracellular to the intracellular compartment during cerebral ischemia. Lamotrigine, a neuronal Na(+) channel blocker, has been shown to attenuate the increase in extracellular concentrations of excitatory amino acids (EAA) during ischemia and to improve neurological and histological outcome. Because of its proven ability to reduce EAA levels during ischemia, lamotrigine should also minimize excitotoxic-induced increases in intracellular water content and therefore attenuate changes in the ADC. In this study, we sought to determine the effect of lamotrigine on intra- and extracellular water shifts during transient global cerebral ischemia. Fifteen New Zealand white rabbits were anesthetized and randomized to one of three groups: a control group, a lamotrigine-treated group, or a sham group. After being positioned in the bore of the magnet, a 12-min 50-s period of global cerebral ischemia was induced by inflating a neck tourniquet. During ischemia and early reperfusion there was a similar and significant decrease of the ADC in both the lamotrigine and control group. The ADC in the sham ischemia group remained at baseline throughout the experiment. Lamotrigine-mediated blockade of voltage-gated sodium channels did not prevent the intracellular movement of water during 12 min 50 s of global ischemia, as measured by the ADC, suggesting that the ADC decline may not be mediated by voltage-gated sodium influx and glutamate release.     

A possible role for nerve growth factor in the augmentation of sodium channels in models of chronic pain

Inflammation induces an upregulation of sodium channels in sensory neurons. This most likely occurs as a result of the retrograde transport of cytochemical mediators released during the inflammatory response. The purpose of this study was to determine the effect of the subcutaneous administration of one such mediator, nerve growth factor (NGF), on the production of sodium channels in neurons of the rat dorsal root ganglion. For this, hindpaw withdrawal from either a thermal or mechanical stimulus was measured in rats at selected intervals for up to 2 weeks following injections of NGF. Sodium channel augmentation was then examined in dorsal root ganglia using site-specific, anti-sodium channel antibodies. Both thermal and mechanical allodynia was observed between 3 and 12 h post-injection. The hyperalgesic response returned to baseline by approximately 24 h post-injection. Sodium channel labeling was found to increase dramatically in the small neurons of the associated dorsal root ganglia beginning at 23 h, reached maximum intensity by 1 week, and persisted for up to 3 months post-injection. Pre-blocking NGF with anti-NGF prevented the NGF-induced decrease in paw withdrawal latencies and significantly reduced the intensity of sodium channel labeling. The results indicate that NGF is an important mediator both in the development of acute hyperalgesia and in the stimulation of sodium channel production in dorsal root ganglia during inflammation.     

Directed sampling for electrolyte analysis and water content of micro-punch samples shows large differences between normal and ischemic rat brain cortex

Changes in sodium, potassium, and water content in brain tissue are important in the progression of pathology that follows ischemic stroke. Determining these parameters regionally in rodent models of experimental ischemia has been limited because typical tissue weights of more than 35 mg are too large. Identifying ischemic tissue to direct tissue sampling towards ischemic cortex is also represents a difficult generally unresolved area. We suggest that larger differences between normal and ischemic cortex of sodium, potassium, and water content than previously observed can be obtained from directed sampling of 2-mg brain tissue in a model of focal cerebral ischemia. In five rats, the middle cerebral artery and both common carotid arteries were occluded for 4.9+/-0.13 h (mean+/-SEM). Punch-sampling of 1-mm diameter tissue cores for water content (H(2)O%) by the wet-dry method, and [Na(+)] and [K(+)] by flame photometry, was guided by the observation of a subtle change in the surface reflectivity of ischemic cortex of quickly dried, 20-microm frozen brain sections, that was confirmed by MAP2 immunohistochemistry. The ratio of the lesion areas as determined by the reflective change and MAP2 immunoreactivity was 0.96+/-0.03 (n=5). In ischemic cortex H(2)O% was 79.9%+/-0.8%, [Na(+)] was 550+/-25 mEq/kg dry-weight, and [K(+)] 94.2+/-19.2 mEq/kg dry-weight (n=5), all significantly different from the values in border zone cortex, and in cortex contralateral to ischemic cortex and border zone (for all samples n=60, mean wet weight 2.037+/-0.046 mg). Differences between ischemic and normal cortex were 5.4+/-1.1%, 317+/-21 mEq/kg dry-weight, -304+/-27 mEq/kg dry-weight (n=5) for H(2)O%, [Na(+)], and [K(+)]. These differences between ischemic and normal cortex are 1.4-2.5, 1-3.11, and 1.4-3.5 times greater, respectively, than previous results obtained using samples weighing 35 mg or more. These results extend the association of sodium and potassium with ischemic brain edema in the rodent model, and show that these classical measurements can keep pace with the regionality of histochemical and morphological methods.     

小剂量补佳乐在诱导排卵中对子宫内膜发育的影响

目的探讨小剂量补佳乐是否能改善克罗米芬诱导排卵中的子宫内膜发育。方法45例不明原因或男方因素的不育妇女分为三组，自然周期组、克罗米芬组(CC组)、克罗米芬 补佳乐组(CC PGV组)各15例，观察三组hCG日及hCG 9d激素环境、子宫内膜厚度、子宫动脉搏动指数(PI)，hCG日子宫内膜类型。结果CC组无论hCG日还是hCG 9d内膜厚度均明显小于自然周期组，而CC PGV组内膜厚度均明显大于CC组。CC组和CC PGV组子宫动脉PI无显著差别，但均显著大于自然周期组。结论小剂量补佳乐能改善克罗米芬诱导排卵中子宫内膜的发育。     

家蝇拟除虫菊酯抗药性的分子生物学监测

目的　建立一种可以早期检测昆虫拟除虫菊酯抗药性的方法 ,以利于抗药性的控制。方法　采用聚合酶链反应 (PCR)方法 ,用自行设计的特异引物 ,对昆虫的钠离子通道基因进行扩增。结果　共检测敏感家蝇和溴氰菊酯抗性家蝇各 2 0只 ,在所有抗性家蝇的钠离子通道基因中均扩增出特定大小基因片段 ( 183bp) ,表明基因发生了抗性突变。而在所有敏感家蝇的钠通道基因中均未扩增出该基因片段 ,表明未发生基因突变。结论　PCR能够在短时间内完成对昆虫拟除虫菊酯抗性的检测 ,为早期监测昆虫对拟除虫菊酯的抗药性提供了快速可行的方法。     

两种抗凝血灭鼠剂实验室及现场灭鼠效果比较

目的比较溴鼠灵毒饵和杀特宁B型饵剂实验室及现场灭鼠效果,为今后灭鼠工作提供科学依据。方法用有选择给饵法测定毒饵的适口性及实验室毒杀效果;用粉迹法测定现场鼠密度,计算校正灭鼠率。结果溴鼠灵毒饵的摄食系数为1.10,杀特宁B型饵剂为1.35;2种毒饵实验室灭鼠率均为100%;现场校正灭鼠率,溴鼠灵毒饵为86.67%,杀特宁B型饵剂为42.99%。结论2种抗凝血灭鼠剂均具有很好的适口性及室内毒杀效果,但现场条件下溴鼠灵毒饵灭鼠更好,可以用于社区的大面积灭鼠。     

无痛内镜与普通内镜检查临床对比研究

目的:评价在麻醉下实施内镜检查的效果及安全性。方法:选择行胃镜和结肠镜检查的患者各60例,分为3组,分别应用丙泊酚、丙泊酚联合芬太尼静脉麻醉(观察组)及常规操作(对照组)检查,对检查过程中患者血压、心率、血氧饱和度及检查成功率、检查反应进行观察分析。结果:与对照组比较,各观察组中患者收缩压、心率在检查中均下降,差异有统计学意义(P<0.05),血氧饱和度无明显变化。对照组患者在检查中收缩压、心率均较检查前增加,差异有统计学意义(P<0.05)。观察组在检查后愿意再次接受检查者明显增多。结论:应用麻醉方法行内镜检查是安全、舒适、有效和无痛苦的。     

Laparoscopic ovarian drilling for women with anovulatory polycystic ovarian syndrome: a district general hospital experience

This is a retrospective study involving 100 anovulatory women with polycystic ovarian syndrome (PCOS) who had laparoscopic ovarian drilling (LOD) between January 1995 and May 2002 at the Royal Berkshire Hospital, Reading, a large district general hospital (DGH). The aim was to evaluate the efficacy of LOD in the treatment of women with anovulatory PCOS in a DGH setting. We also looked at the factors predicting the clinical outcome to be able to counsel the patients pre-operatively. The study showed that the spontaneous pregnancy rate after LOD was 32.46%. A further 28.5% conceived after induction of ovulation with clomiphene citrate (CC) or purified follicular stimulating hormone (Metrodin HP), with a cumulative pregnancy rate of 74%. We did not find a significant difference in the luteinising hormone to follicular stimulating hormone (LH:FSH) ratio of greater than 2.5, LH level of greater than 10 IU/l, body mass index (BMI), age or duration of infertility between the group of women who conceived and those who failed to conceive, in response to LOD.     

Simultaneous treatment with citrate prevents nephropathy induced by FYX-051, a xanthine oxidoreductase inhibitor, in rats.

The possible mechanism of the underlying nephropathy found in the rat toxicity study of FYX-051, a xanthine oxidoreductase inhibitor, was investigated. Rats received oral treatment of either 1 or 3 mg/kg of FYX-051, with and without citrate for four weeks to elucidate whether nephropathy could be caused by materials deposited in the kidney. Furthermore, analysis of the renal deposits in rats was also performed. Consequently, interstitial nephritis comprising interstitial inflammatory cell infiltration, dilatation, basophilia and epithelial necrosis of renal tubules and collecting ducts, deposits in renal tubules and collecting ducts, and so forth was seen in six of the eight rats and in all eight rats in the 1 and 3 mg/kg FYX-051 alone groups, respectively, with the intensity in the 3 mg/kg group being moderate to severe. In the simultaneous treatment with citrate group, however, no alterations were observed in the kidney, except for minimal interstitial nephritis in one instance in the 3 mg/kg FYX-051 + citrate group along with an increased urinary pH, leading to an increase in xanthine solubility. Analysis of intrarenal deposits showed that the entity would be composed of xanthine crystals. The present study, therefore, showed that nephropathy in rats occurring after the administration of FYX-051 was a secondary change caused by xanthine crystals being deposited in the kidney, and no other causes could be implicated in this kidney lesion.     

枸椽酸氢钾钠治疗输尿管小结石的临床研究

目的:探讨枸椽酸氢钾钠治疗输尿管小结石的临床价值.方法:将63例伴肾绞痛的输尿管小结石(＜0.6 cm)患者分为用药组31例和对照组32例,均采用解痉、输液、利尿治疗,用药组加口服枸椽酸氢钾钠颗粒,并记录排石情况,排出结石的大小.结果:在观察期内用药组28例排出结石,有效率90.3%,对照组22例排出结石,有效率68.8%,两者存在统计学差异(P＜0.05),排出结石的时间用药组(3.3±2.1)d,对照组(4.1±2.3)d,存在统计学差异(P＜0.05),排出结石大小比B超测得均小,用药组有统计学差异(P＜0.05),对照组无统计学意义(P＞0.05),用药组未出现药物不良反应.结论:枸椽酸氢钾钠能有效缩小输尿管结石,加快结石的排出,是内科保守治疗输尿管小结石安全有效的辅助治疗药物.