8-氧鸟嘌呤脱氧核苷在快速老化小鼠SAMP8海马中表达的增龄性变化研究

目的观察8-氧鸟嘌呤脱氧核苷（8-oxo-7,8-dihydroguanine,8-oxo-dG）在快速老化小鼠SAMP8海马不同区域的表达,探讨其变化与SAMP8增龄的关系。方法选用1、4、8、12月龄快速老化小鼠SAMP8（每组各6只）,对照组为同龄抗快速老化小鼠SAMR1（每组各6只）,用免疫组化法检测海马不同区域内8-oxo—dG的表达水平。结果8-oxo-dG在海马不同区域均有表达,且主要在海马神经细胞胞核内表达。对照组SAMR1小鼠海马各区域8-oxo-dG的吸光度定量结果显示各月龄组间无统计学差异（P〉0．05）;1、4月龄组SAMP8小鼠海马各区域8-oxo-dG的吸光度定量结果与同龄匹配的SAMR1小鼠间无统计学差异（P〉0．05）;8、12月龄组SAMP8小鼠海马各区域8-oxo-dG的吸光度定量结果分别显著高于1月龄和4月龄组（P〈0．05）,也分别显著高于同龄SAMP1对照组（P〈0．05）。结论8-oxo-dG在SAMP8快速老化小鼠海马中的水平随增龄而显著增高。     

丹参酮对β-淀粉样肽致拟痴呆小鼠的保护作用及机制

目的探讨丹参酮对β-淀粉样肽（A13）致拟痴呆小鼠（AD小鼠）的保护作用及机制。方法利用单侧脑室一次性注射可溶性大片段Aβ1-42复制拟痴呆动物模型，将小鼠随机分为对照组，模型组、脑复康（200mg／kg）组及丹参酮（20、40、80mg／kg）组。通过避暗实验和Morris水迷宫实验观察丹参酮对AD小鼠学习记忆能力的影响及血清、脑、肝脏内SOD、MDA含量和皮层和海马中AChE、NO含量的变化。结果脑室内注射Aβ1-42后小鼠出现学习记忆障碍；血清、脑、肝中SOD活性降低、MDA含量增加；大脑皮层、海马组织中AChE、NO含量上升；应用丹参酮后AD小鼠学习记忆能力提高，丹参酮组中、高剂量组抑制了血清、脑、肝中SOD活性的降低和MDA含量的增加（P〈0．01，0．001），亦减少大脑皮层、海马组织中AChE、NO的生成（P〈0．05，0．01，0．001）。结论丹参酮对β-淀粉样肽致拟痴呆小鼠具有一定的保护作用，其机制可能与抗氧化、抑制AChE生成有关。     

大黄素对海人酸致痫小鼠海马神经细胞的保护作用

目的探讨大黄素对海人酸诱导的小鼠癫痫持续状态后海马神经细胞的保护作用。方法 90只ICR雄性小鼠随机分为对照组、癫痫持续状态组、大黄素治疗组(分为100、200和400 mg/kg组),每组18只。采用海人酸建立小鼠癫痫持续状态模型。通过HE染色和TUNEL染色观察大黄素对癫痫鼠海马神经细胞的形态学变化和凋亡情况;比色法测定谷苷胱肽(GSH)和丙二醛(MDA)的含量以及超氧化物歧化酶(SOD)的活力; RT-PCR和Western blot检测海马组织中IL-1β、TNF-α、caspase-3 mRNA和蛋白的表达。结果大黄素(200和400 mg/kg组)可显著减轻癫痫所致的海马神经细胞的损伤和凋亡,提高GSH和SOD的活性,降低MDA的活性(P 0. 05);同时抑制海马中IL-1β、TNF-α及caspase-3mRNA和蛋白的表达量(P 0. 05)。结论大黄素对小鼠癫痫持续状态后海马神经细胞具有抗氧化、抗炎和抗凋亡等神经保护作用,其作用机制可能与提高GSH和SOD的活性,降低MDA的含量,并抑制IL-1β、TNF-α及caspase-3的表达有关。     

双氢麦角碱对血管性痴呆小鼠海马乙酰胆碱酯酶活性变化的影响

目的探讨双氢麦角碱对血管性痴呆（VD）小鼠海马组织乙酰胆碱酯酶（AchE）活性变化的影响。方法将75只小鼠随机分为假手术纽、模型组和药物纽。药物组和模型组采用双侧颈总动脉反复缺血再灌注法制备VD模型，术后第29天和第30天测试学习记忆成绩，术后第30天检测海马AchE含量，并研究双氢麦角碱对二者的影响。结果（1）模型组小鼠学习记忆成绩较假手术组明显下降（P〈0．01），治疗组小鼠学习记忆成绩明显优于模型组小鼠（P〈0．01）；（2）模型组小鼠海马AchE活性较假手术组明显降低（P〈0．01），治疗组小鼠海马AchE活性显著高于模型组小鼠（P〈0．05）。结论双氢麦角碱能改善VD小鼠的学习记忆功能，提高海马组织内的AchE活性。     

精神分裂症患者机体抗氧化功能指标的实验研究

目的 探讨机体抗氧化能力在精神疾病发病机理中的作用及其临床意义。方法 采用化学比色法检测176例精神分裂症患者血清中SOD、MDA、GSH－Px、VC、VE和NO含量。结果 精神分裂症患者血清中SOD、MDA、NO含量均高于对照组（P＜0．05或0．01）;GSH－Px、VC含均低于对照组（P＜0．01）;VE两者无显著差异（P＞0．05）;精神分裂症家族史阳性者血清中NO高于精神分裂症阴性家族史者（P＜0．05）;精神分裂症患者抗氧化能力含量可因病程、性别、年龄的不同而不同;精神分裂症患者治疗后SOD、MDA低于治疗前（P＜0．01）。结论 精神分裂症患者体内自由基代谢异常可能是精神分裂症发病的生物学因素之一。     

Aβ1～42对不同年龄组大鼠ChAT和AchE活性变化的实验研究

目的 观察大鼠海马注射Aβ1～42后行为学习记忆和ChAT、AchE活性的变化情况。方法 采用Y迷宫测试行为学习记忆情况和比色法测定ChAT、AchE活性变化。结果 成年、老年模型组出现了行为学习记忆障碍,同时基底前脑ChAT活性降低（P〈0．05）,而海马AchE活性变化不明显（P〉0．05）。幼年模型组基底前脑ChAT活性变化不明显（P〉0．05）,但海马区AchE活性降低（P〈0．05）。结论 ChAT活性的变化在Aβ机制中起重要作用,提高ChAT活性是治疗AD的靶点之一。     

糖尿病大鼠蛛网膜下腔出血后海马组织中caspase-3、Bax和Bcl-2的表达及醒脑静干预的研究

目的探讨醒脑静对糖尿病大鼠蛛网膜下腔出血（sAH）后海马组织凋亡相关因子天冬氨酸特异性半胱氨酸蛋白酶（casDase-3）、Bax和Bcl-2表达的影响。方法成年雄性Wistar大鼠28只,按随机数字表法随机分为空白对照组（n=7）、糖尿病对照组（n=7）、糖尿病SAH组（n=7）和醒脑静治疗组（n=7）;采用链脲佐菌素（STZ）腹腔注射方法建立糖尿病大鼠模型,然后采用枕大池两次注血法建立糖尿病大鼠SAH模型。SAH后48h取海马组织,用实时聚合酶链式反应检测caspase-3、Bax及Bcl-2的mRNA的表达,并用免疫印迹法测定它们蛋白表达,进行验证。结果空白对照组和糖尿病对照组大鼠海马组织中的caspase-3、Bax和Bcl-2的mRNA表达量均无显著差异（P〉0．05）;与空白对照组和糖尿病对照组相比,糖尿病SAH组和醒脑静治疗组其mRNA表达量均显著升高（P〈0．05）;醒脑静治疗组caspase-3和BaxmRNA表达水平均显著低于糖尿病SAH组大鼠（P〈0．05）,而Bcl-2mRNA表达水平却明显高于糖尿病SAH组（P〈0．05）。它们蛋白表达变化与mRNA表达基本相符。结论醒脑静抑制糖尿病SAH大鼠海马组织促凋亡相关因子表达,而促进抗凋亡相关因子表达,从而发挥保护作用。     

氯氮平对谷氨酸功能低下精神分裂症小鼠模型的作用

目的 观察氯氮平对地卓西平马来酸盐（MK-801）所致谷氨酸功能低下精神分裂症小鼠模型的高活动性及刻板行为的作用。方法 昆明种小鼠130只。（1）取34只小鼠分为4组：溶媒空白对照组（腹腔注射溶媒，以下简称对照组）；3种氯氮平剂量（1．0，1．5，2．0mg／kg体质量，腹腔注射）组；每组8～10只，观察氯氮平对小鼠探究行为和自主活动的影响。（2）取46只小鼠分为5组，分别为对照组、MK-801模型组（溶媒＋MK-801，0．25mg／kg体质量，腹腔注射）及3种剂量（同上）氯氮平组分别加MK-801（0．25mg／kg体质量，腹腔注射），每组8～10只，观察氯氮平对MK-致801小鼠自主活动增加的影响。（3）取50只小鼠，每组10只，给药方案同“（2）”，观察氯氮平对MK-801引起的刻板行为的影响。结果 （1）与对照组比较，氯氮平剂量为1．5mg／kg体质量和2．0mg／kg体质量时，小鼠的探究行为及自主活动总路程减少（P均〈0．001）；但剂量为1．0mg／kg时，对小鼠的探究行为及自主活动均无影响（P均〉0．05）。（2）氯氮平剂量为1．0～2．0mg／kg体质量时，呈剂量依赖性抑制由MK-801引起的自主活动增加（均P〈0．05）。（3）氯氮平剂量为1．5～2．0mg／kg体质量时，呈剂量依赖性抑制MK-801引起的刻板行为（均P〈0．05）。但低剂量（1．0mg／kg体质量）氯氮平对MK-801引起的刻板行为无明显影响（P〉0．05）。结论 氯氮平对MK-801所致谷氨酸功能低下精神分裂症小鼠模型不同脑区的作用有选择性，低剂量时抑制由中脑边缘、中脑皮质系统介导的高活动性，较高剂量时抑制由中脑边缘、中脑皮质系统及黑质纹状体系统控制的高活动性及刻板行为。     

前列腺素E1对糖尿病周围神经病变患者谷胱甘肽过氧化物酶活性的影响

目的观察前列腺素E1（PGE1）对糖尿病周围神经病变患者血清谷胱甘肽过氧化物酶（GSH-Px）活性的影响，探讨其在糖尿病周围神经病变中的治疗作用。方法将60例糖尿病周围神经病变患者随机分为PGE1治疗组（PGE1组）和灯盏花素对照组（DZ组），各30例。采用周围神经病变诊断评分标准（DNS）评价两组治疗前后效果．并对两组给药前后血清GSH-Px活性进行测定比较。结果（1）PGE1组与DZ组治疗前DNS评分差异无显著性意义（P〉0．05）。PGE1组治疗后DNS评分较治疗前显著下降（P〈0．05）。DZ组DNS评分治疗前后改变无显著性意义（P〉0．05）。两组治疗后DNS评分差异有显著性意义（P〈0．05）。（2）PGE1组与DZ组用药前GSH—Px活性分别为（116．07±9．20）ug／mL、（113．00±8．87）ug/mL，治疗后分别为（138．82±9．68）ug／mL、（114．43±9．11）ug/mL。PGE1组用药前后GSH-Px活性变化差异有显著性意义（P〈0．01），DZ组用药前后差异无显著性意义（P〉0．05）。两组治疗后GSH-Px活性差异有显著性意义（P〈0．05）。结论PGE1可以通过提高GSH-Px活性间接影响氧化平衡从而改善糖尿病周围神经细胞功能。     

电针对拟老年性痴呆大鼠学习记忆和海马神经元突触形态可塑性的影响研究

目的探讨电针对拟老年性痴呆大鼠学习记忆功能和海马CA1区突触可塑性的影响。方法采用腹腔注射D-半乳糖、东莨菪碱,胃饲三氯化铝（AlCl3）制备多因素损伤拟老年性痴呆动物模型,在造模同时给予电针干预,穴位选择为百会、大椎、肾俞、足三里。应用跳台实验检测大鼠学习和记忆能力,透射电镜测定突触面数密度、面积密度和体积密度变化。结果跳台实验（潜伏期、错误次数）提示,与空白对照组比较,模型组大鼠出现明显的学习记忆功能障碍,潜伏期缩短,错误次数增加（P〈0．01）。与模型组比较,电针治疗能够改善大鼠的学习和记忆功能,延长潜伏期和减少错误次数（P〈0．05,P〈0．01）。与空白组比较,模型组大鼠海马CA1区突触面数密度、面积密度和体积密度均减小（P〈0．05）;模型电针组大鼠海马CA1区突触面数密度、面积密度和体积密度均有所增大（P〈0．05）。结论电针可以改善拟AD鼠的学习记忆功能,机制可能为电针促进突触可塑性发挥的作用。     

Local nonuniformities in the syncytium of the horizontal cells of the retina in the turtle

Electrical coupling between horizontal cells of the turtle retina was investigated by means of two microelectrodes (current and recording ones) penetrating neighbouring cells at a fixed distance from each other. The morphological coupling was revealed by means of fluorescent dye Lucifer Yellow. The electrical coupling was confirmed between elements of similar type (L1--axonal terminals, or L2--cell bodies, or R/G type cells) and no coupling was found between elements of different types, though L1 and L2 are directly connected through thin axons. In the L1 syncytium the electrical coupling at small (less than or equal to 50 microns) but fixed distances between microelectrodes could differ several times depending on the minimal displacement of microelectrodes. This local nonuniformity of coupling can be explained on the basis of structural nonuniformities in the L1 (axon terminal) network. It is unlikely however that the structural nonuniformities can influence the functional properties of horizontal cell network when the retina is stimulated adequately (by light).     

Asymmetry in the structural organization of the ganglion layer of the retina in the frog

Silver-impregnated retinal preparations were used to study the distribution density and topographic features of small and large ganglionic cells (GC) of Rana ridibunda and Rana temporaria. For both species the increased density of GC (a streak) stretched higher than the naso-temporal axis passing through the optic disk. Beyond the streak the density of small GC was maximal in the central zone of the retina and decreased towards its periphery. For the upper quadrants of the retina the density of small GC was higher than that for the lower ones by 26% on the average. On the contrary, the density of large GC was higher in the lower part of the retina as compared to the upper one, the difference being more pronounced for R. temporaria. The density of large GC was also asymmetric with respect to the dorso-ventral axis being higher in nasal quadrants than in temporal ones by 40-55%. The highest density of large GC was found in the middle zone of the retina. The found structural asymmetry in the retinal output raster may bear an adaptively ecological meaning and may condition the particularities of the formation of the visually guided prey-catching and avoidance reactions.     

Inhomogeneities in the propagation of the slow wave in the stomach

The propagation of the slow wave in the stomach and its role in inducing sweeping peristaltic contractions toward the pylorus, essential for a proper digestion and emptying, have been studied for many years. Irregularities in the timing or in the pattern of propagation of the slow wave have been known to induce various gastric malfunctions and, recently, several types of gastric dysrhythmias have been described which could lead to gastric contraction abnormalities. In this study, Du et al. have analyzed the disturbances caused by a simple transmural incision in a human stomach, performed to obtain a biopsy of the muscle, on the propagation pattern of the slow wave. In addition, they show that such an incision may by itself also induce new types of gastric dysrhythmias. These results are important in demonstrating that the function of the stomach can easily be disturbed by such procedures. This mini‐review describes several ways in which inhomogeneities in propagation may affect the conduction pattern of the slow wave, including the genesis of several dysrhythmias, and what is currently known about their impact on gastric contraction and digestion.     

Early stages in the formation of the cerebellum in the frog

The formation of the cerebellum was studied during the first 6 months of the tadpole stage of the bullfrog by using standard histological methods and reconstructions from serial horizontal sections. Three major developmental phases were noted in the formation of the cerebellum. (1) During the first 5 weeks of development, the neuroepithelium proliferated and the dorsal mesencephalic plates increased in size. (2) Starting in the sixth week, a patch of neuroepithelium began to differentiate and gave rise to a small population of Purkinje cells. In subsequent weeks, the area of differentiation continued to spread and a Purkinje cell layer became established along the dorsal margin of the cerebellar plate. (3) In the 12th week, the ventrolateral part of the cerebellar plate began to increase in size and generate two populations of small cells. The lateralmost part of the neuroepithelium in this area generated a group of cells that formed an external granular layer that was one cell deep. Cells of this external granular layer migrated inward into the primitive molecular layer, and by the 26th week only a remnant of an external granular layer remained in the cerebellum. The more medially situated part of the neuroepithelium gave rise to another population of small cells that formed a column, which appeared to be continuous with the Purkinje cells, but differed from them in size. It should be noted that full maturation of the cerebellum occurs during metamorphosis, which in this species remains some 2 years away.     

Challenges in the Management of the HIV Patient in the Third Decade of AIDS

The epidemic of AIDS has been increasingly recognized as a major health and socioeconomic problem, not only in the United States or Africa, but also the rest of the world. The face of the epidemic has changed. The role that mental health providers play has also significantly grown as the epidemic continues on. Prior to the introduction of Highly Active Anti-Retroviral Therapy (HAART) and other advances in HIV care, the patients faced issues that related to death and dying. These advances brought with them renewed hope and resurrected lives. The patients fought with issues related to living new lives with HIV no longer an imminent death threat. In the third decade of AIDS, the struggles of the post-HAART era continue but bring with it more challenges. Mental health providers need to familiarize themselves with these issues so that they can better help HIV patients cope with this devastating disease.     

Analysis of the habituation-like changes in transmission in the temporodentate pathway of the rat

Habituation-like decrements in extracellular measures of synaptic activation (population EPSP) and cell discharge (population spike) were analyzed in the dentate gyrus of the rat following repetitive low-frequency stimulation of the medial and lateral entorhinal cortex. Stimulation of either subdivision of the entorhinal projection system resulted in comparable habituation-like response decrements with similar stimulation regimens. However, habituating stimulation of one subdivision did not result in decreased responsiveness to stimulation of the other. Repetitive low-frequency stimulation or even a single pulse delivered to either subdivision did, however, result in a potentiation of granule cell discharge in response to stimulation of the other subdivision (a form of heterosynaptic potentiation). This heterosynaptic potentiation of granule cell discharge was not accompanied by any increase in the extracellular EPSP. Comparisons of the relationship between the population EPSP and population spike before and during habituating stimulation revealed changes in cell discharge in response to the habituating stimulus which could not be accounted for by changes in synaptic activation alone. The results suggest that repetitive activation of the temporodentate pathway alters granule cell output as a result of two processes, a habituation-like decrement in synaptic activation, and a potentiation of granule cell discharge as a consequence of prior activation.     

Gradients of histogenesis in the ependymal lining of the third ventricle in the rabbit

Tritiated thymidine autoradiography was used to analyze the site, time of origin, and developmental gradients of the specialized lining of the ependymal surface of the third ventricle. Cells destined to form the ependyma are generated between days 15 and 22 of embryogenesis (gestation: 30 +/- 2 days), the majority of the cells undergoing final division on the 18th day of gestation. Ependymal cells originate in an orderly fashion according to 3 gradients. Two gradients of opposite direction (ventrodorsal and dorsoventral) are found in the parasaggital plane. Both gradients start at the level of the hypothalamic sulcus, progressively departing from this anatomical landmark as histogenesis progresses. A third gradient occurs in the caudorostral axis, such that cells located in caudal regions originate earlier than those located in rostral sectors. Thus, an orderly relationship exists between the time of origin of ependymal cells and their final location within the lining of the ventricular wall. These findings indicate, once again, the topographic nature of the gradients of histogenesis. The histogenic gradients displayed by the ependymal lining of the third ventricle appear strongly related to those exhibited by other diencephalic derivatives. The latter suggests that common factors govern the developmental sequence of all diencephalic derivatives as a function of their relative topographic location, independently of their functional role in the adult.