Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review

ObjectiveSystematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations).MethodsPubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards.ResultsERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients.ConclusionsWhile there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms.SignificanceThe review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.     

Sex effects in defensive behavior: Baseline differences and drug interactions

Female rats consistently show a pattern of differences in defensive behaviors compared to males which parallel the effects of exposure to a nonpainful threat stimulus (cat or cat odor) in the same tests and measures. These indications of greater defensiveness for females are particularly common in situations involving potential, as opposed to actual and present, threat, a factor which probably also reflects ceiling or floor effects in situations involving very intense defensiveness. In addition, pharmacological studies indicate sex differences in the effects of selective serotonin (5-HT) receptor agonists and antagonists on defensive responding. These findings indicate that sex effects must be considered in studies of the pharmacological control of defensive behaviors, and suggest that responsivity to sex effects may be an additional criterion for the suitability of animal models of anxiety.     

术中即时扩张皮肤面积增加与压力和时间的量效关系

目的探讨术中即时扩张皮肤面积增加与压力、时间的量效关系。方法用6头小型猪，压力参数分别为15、20、25kPa，时间参数为60、90min，配对组成6个实验组，1个对照组，36个实验部位。在每只猪背部皮下均匀埋置100ml圆形扩张器6个，术中即时扩张皮肤，观察扩张皮肤各径线移位特点，计算面积变化。结果扩张区周边皮肤向中心蠕动和扩张器表面皮肤伸展同时存在。扩张皮肤面积扩大在一定范围内与压力、时间增加成正比，20kPa、60min组合增幅最大，此后增幅明显减少，并逐渐引发皮肤病理性改变。结论皮肤可在一定范围内通过术中即时扩张获得面积有效增加。     

Ethanol regulated preference in rats

A series of experiments evaluated the determinants of preference for mixtures of ethanol plus sucrose relative to sucrose in rats. One dipper served 10% ethanol mixed with 10% sucrose, and the second dipper served 10% sucrose. Lever presses operated each dipper according to a variable-interval 5-s schedule. In three experiments the subjects were given pre-session meals of sucrose (2.5–20 ml) or sucrose (20 ml) plus chow (5 or 10 g). Pre-session meals decreased responding maintained by sucrose but not responding maintained by ethanol mixture. In two experiments body weight was varied from 85% to 125% of the initial free-feeding values. Increases in body weight, like pre-session meals, decreased responding reinforced by sucrose, but typically did not decrease responding reinforced by ethanol mixture. Throughout most of the study, ethanol consumption remained at about 1.25 ml per half hour session (3–4 g/kg per 30 min). For example, pre-session access to ethanol mixture decreased within-session ethanol consumption, but total consumption, counting both sources, remained about 1.25 ml/session. The within-session patterns of responding also differed. Responding reinforced by ethanol mix decreased as a function of ethanol consumption, whereas responding reinforced by sucrose was relatively constant throughout the session. The simplest explanation of the results is that ethanol's pharmacological consequences regulated preference.     

缩窄门静脉主干1／2加丝线慢性栓塞术制备犬门静脉高压症模型

目的:探索操作简便且效果满意的门静脉高压症动物模型制备方法.方法:缩窄门静脉主干1/2加丝线慢性栓塞术,通过22条犬进行实验.结果:除1条死亡外.其余21条术后3～4周时门静脉压力升高至2.83±0.66kPa(术前1.33±0.28kPa,P<0.001):胃镜、门静脉造影及病理学检查证实,17条犬有食管胃底曲张静脉形成,形成率80.95%(其中方法完善后制备的14条、形成率100%),12条发生门脉高压性胃病,发生率57.14%.1条观察至术后4月.门静脉高压症表现仍然存在.结论:该法简便易行、建立模型周期短、成功率高且质量可靠并较持久.     

石刻雕塑作业劳动卫生学调查及实验研究

测定了石雕作业粉尘浓度，几何平均浓度为８２．３５～３．６７ｍｇ／ｍ３。工人职业性健康检查结果，接尘工人的咽部充血、咳嗽、咯痰检出率高于对照组；肺功能低下的检出率也高于对照组。该厂自１９７２年以来发生尘肺患者１７例，其病情发展和晋期缓慢，发病工龄长。动物实验研究表明，石雕粉尘有轻微的致纤维化作用。     

门脉高压性胃病患者的胃壁血气变化

作者观测了４３例门脉高压症患者股动脉血ＰＯ２、胃网膜有动静脉胃壁支血ＰＯ２、胃壁支静脉及肘静脉血ｐＨ、ＨＣＯ３－和胃网膜右静脉压力，其中２３例并有非出血期门脉高压性胃病。结果表明：①门脉高压症患者的股动脉血ＰＯ２低于对照组；②门脉高压症患者胃网膜右动静脉胃壁支血氧分压差低于对照组，胃网膜右静脉压力高于对照组，胃壁支静脉血ｐＨ和ＨＣＯ３－低于对照组和同组肘静脉血。并有门脉高压性胃病者这些变化更为显著。提示门脉高压性胃病的发病机制在于门脉系压力增高、胃粘膜下动静脉短路开放、胃粘膜缺血缺氧和胃壁局部酸中毒。     

米诺环素对压力作用下体外培养视网膜神经细胞凋亡的抑制

目的 观察米诺环素对压力系统作用下大鼠视网膜神经细胞(RNs)的活性及凋亡的影响，探讨其对受损RNs保护的可能机制。 方法 制备大鼠RNs体外加压培养模型，通过细胞形态学观察、四唑盐（MTT）比色法测定细胞活力、吖啶橙/溴化乙锭（AO/EB）染色法检测细胞凋亡率等方法观察不同浓度的米诺环素对上述损伤细胞的保护作用，并用免疫细胞化学法观察iNOS和caspase 3表达的改变。 结果 加压培养后RNs与对照组相比形态改变较明显，细胞活力降低，5393%的细胞发生凋亡。20000 μmol/L的米诺环素治疗组则细胞形态改善，活力显著增高，1729%的细胞发生凋亡；免疫细胞化学法显示细胞内iNOS和caspase-3表达较加压损伤组减少。 结论 一定剂量的米诺环素在体外可有效抑制压力引起的大鼠RNs损伤及凋亡；抑制iNOS和caspase-3的表达可能是其潜在作用机制。     

新胆碱酯酶抑制剂对实验性重症肌无力的治疗作用

本文应用实验性重症肌无力模型研究了7种新的胆碱酯酶抑制剂对实验性重症肌无力的治疗作用,其中包括6种二甲氨基甲酸烷氧(烷硫)基苯酯及1种中草药提取物,大多数化合物对乙酰胆碱酯酶有较强的抑制作用,并见到有不同程度的治疗效果。二甲氨基甲酸-3-叔丁基-4〔2-(1-哌啶基)乙氧基〕苯酯不仅明显改善肌无力症状,而且毒性小、副作用较新斯的明轻,值得进一步研究。     

兔坐骨神经挤压伤的MRI与SEP对比研究

目的:探讨磁共振成像和体感诱发电位以及两者结合在坐骨神经急性挤压伤中的诊断价值。方法:24只兔按钳夹力的不同随机分为A、B两组,左后肢为损伤侧,右后肢为对照侧,建立坐骨神经急性挤压伤模型,于伤后1、2、4、8周行MR扫描,同时行双侧体感诱发电位检查。结果:损伤侧24条神经,有23条MR显示异常,诊断正确率95.8%,假阴性率4.17%(1/24);24条损伤侧坐骨神经,有22条SEP显示异常,诊断正确率91.6%,假阴性率8.3%(2/24)。MRI与SEP对神经损伤的正确诊断率无统计学差异(P>0.05)。MRI与SEP结合起来,24条损伤神经均显示异常,诊断正确率100%。结论:MR与SEP检查可无创、准确地判断神经损伤,两者结合可明显提高神经损伤的正确诊断率,重复性好,可作为神经损伤的较好诊断手段。