Kindling limits the interictal neuronal temporal response properties in cat primary auditory cortex

PURPOSE: The present study examined the effect of electrical kindling on the interictal temporal response properties of single units recorded from primary auditory cortex (AI) of the adult cat. METHODS: Cats were permanently implanted with electrodes in AI, kindled twice daily for 40 sessions, and the contralateral AI was subsequently mapped. Kindling stimulation consisted of 1-s trains of biphasic square-wave pulses applied at a frequency of 60 Hz, 100 microA above the afterdischarge (AD) threshold. The EEG activity was recorded during each kindling session, and the behavioral manifestation was scored. Subsequent to kindling, multiple single-unit responses were recorded under ketamine anesthesia in response to 1-s-long periodic click trains, with click rates between 2 and 64 Hz. Neuronal responses were characterized according to their ability to respond in time-locked fashion to the clicks. RESULTS: Kindling stimulation resulted in progression of the AD characteristics and seizure behavior, with six of 10 kindled cats reaching a fully generalized state. In the fully kindled cats, the best modulation frequencies and limiting following rates for the single-unit responses were significantly lower compared with those of naive and sham controls. CONCLUSIONS: Repeated epileptiform activity interferes with temporal processing in cat auditory cortex in the interictal state. This may have implications for people with epileptic foci in auditory-related areas.     

Induction of long-term depression is associated with decreased dendritic length and spine density in layers III and V of sensorimotor neocortex

Long-term potentiation (LTP) and long-term depression (LTD) are currently the most widely investigated models of the synaptic mechanisms underlying learning and memory. Previous research has shown that induction of LTP increases measures of pyramidal cell dendritic morphology in the hippocampus and layers III and V of the neocortex. However, to date there are no reports on the direct effects of LTD induction on dendritic morphology. Here, we investigated the effects of LTD induction on sensorimotor pyramidal cell dendritic morphology. Rats carried a stimulating electrode in the corpus callosum (midline) and a recording electrode in the right sensorimotor cortex. Each rat received low-frequency stimulation composed of 900 pulses at 1 Hz or handling daily for a total 15 days. Evoked potentials (EPs) of the transcallosal pathway were recorded in the right hemisphere before and after the 15 days of stimulation or handling. The rats were then perfused with saline and the brains were immediately processed for Golgi-Cox staining. Our results show that LTD induction is related to decreases in dendritic length and spine density both in layers III and V as well as a decrease in dendritic branch complexity in layer V of the sensorimotor cortex. Thus, neuronal alterations following modifications in neocortical synaptic efficacy may provide a general mechanism for the physical instantiation of learning and memory.     

Differential neuroplastic changes in neocortical movement representations and dendritic morphology in epilepsy-prone and epilepsy-resistant rat strains following high-frequency stimulation

The epileptogenic-prone (FAST) and epileptogenic-resistant (SLOW) rat strains have become a valuable tool for investigating the neurochemical and neurophysiological basis of epilepsy. This study examined the two strains with respect to their neocortical movement representations and cortical layer III pyramidal cell dendritic morphology in both control and potentiated conditions. FAST and SLOW rats received high-frequency stimulation of the corpus callosum in order to induce long-term polysynaptic potentiation of the transcallosal pathway to the sensorimotor neocortex. Baseline-evoked potentials of this pathway were recorded in the left hemisphere before stimulation, and following 5, 10, 15 and 20 days of high-frequency stimulation. All rats then underwent high-resolution intracortical microstimulation (ICMS) in order to assess functional movement representations of the left caudal forelimb area of the sensorimotor cortex. Immediately following ICMS, the brains were stained with the Golgi-Cox method, and the length, branching and spine density of frontal and occipital neocortical layer III pyramidal neurons were measured. We observed that high-frequency stimulation induced similar increases in polysynaptic potentiation in both rat strains; however, only the FAST strain showed an increase (doubling) in the size of their motor maps. We also observed decreases in dendritic length and branching in the FAST rats, and the opposite profile in the SLOW rats. The potentiated FAST rats also showed an increase in spine density. Our results suggest that differences in susceptibility to epileptogenesis may result in a differential response to stimulation-induced plasticity.     

3,4-二氯苯丙烯酰另丁胺对大鼠脑缺血-再灌注损伤的影响

目的：研究新的桂皮酰胺类衍生物,３－４二氯苯丙烯酰另丁胺（ＡＥＤ８８０１）对大鼠脑缺血／再灌注损伤的影响。方法：采用Ｐｕｌｓｉｎｅｌｌｉ四血管阻断大鼠脑缺血／再灌注模型,观察了ＡＥＤ８８０１对脑组织中水含量、氨基到含量、６－ｋｅｔｏ－ＰＧＦ１α和ＴＸＢ２含量,以及二者之比值的影响。结果：一ＡＥＤ８８０１能够降低脑缺血／再灌注大鼠所引起的脑水含量增加。二采用氨基酸自动分析仪进行检测,发现脑缺血／再灌     

Myometrial invasion by endometrial carcinoma: sonographic assessment

The depth of myometrial invasion by endometrial carcinoma was evaluated using real-time sonography (US) in 20 patients with histologically proved adenocarcinoma of the endometrium. In 14 of 20 (70%) cases, US-based estimation of the depth of myometrial invasion was within 10% of the actual measurement in the gross specimen. The US-based estimation of tumor invasion was low in seven patients, high in four patients, and agreed with pathologic findings (+/- 5%) in nine patients. In four patients with polypoid intraluminal extension of tumor, a deeply invasive tumor was suspected on US but was not found on pathologic examination. In 12 superficially invasive tumors, the continuity of the demarcating subendometrial halo was intact in nine and incomplete in three. In six patients with deeply invasive tumors, this zone was partially disrupted in four, totally disrupted in one, and intact in one. Errors of estimation of the depth of myometrial invasion on US most frequently occurred when a tumor had a significant intraluminal polypoid extension. Demonstration of a subendometrial halo usually indicated superficial invasion, whereas the absence of a halo was frequently associated with deep invasion.     

International Headache Society classification: interobserver reliability in the diagnosis of primary headaches

We assessed interobserver reliability of the International Headache Society (IBIS) classification for diagnosis of primary headaches. The study was performed on 103 patients consecutively seen at two Headache Centres. Each patient was given a structured interview recorded on videotape. Four experienced clinicians then reviewed the interviews separately and made a diagnosis of headache according to IHS criteria at the one- and two-digit levels. At both the one- and the two-digit level the agreement was substantial (Kappa = 0.74 and 0.65, respectively). The analysis of reliability for each of nine items necessary for diagnosis showed an agreement ranging from substantial (Kappa = 0.69) to almost perfect (Kappa = 0.89). Our results indicate that the IHS classification has a good reliability for the diagnosis of primary headaches at the one- and two-digit levels.     

多普勒超声诊断移植肾排斥反应与病理检查及肾功能指标的对比分析

目的：以病理活检结果为金标准，评估多普勒超声检查对移植肾排斥反应的诊断价值。方法：选择2003—01/2006—12在中国医科大学附属第一医院器官移植科行肾移植并在术后行超声检查的患者176例，均知情同意。①实验分组：根据术后移植肾功能分为2组，移植肾功能不良组78例，其中30例次行病理活检；移植肾功能正常组98例。②实验方法及评估：对患者移植肾行多普勒超声检查，参数选择峰收缩期流速、平均舒张期流速、阻力指数及血管显示率。血管显示率的评估标准（0～5级）：0级为肾动脉及其远侧血管未显示；5级为肾各级血管均显示良好。以病理活检结果为金标准，分别选取阻力指数=0．7，0．75，0．8，0．85为诊断界值进行诊断试验。结果：169例患者进入结果分析，脱落7例。①峰收缩期流速、平均舒张期流速不呈正态分布，无法作为肾功能评价指标。30例次病理活检中共有28例次被确诊为排斥反应，急性排斥反应15例次，慢性排斥反应13例次。②肾功能正常组患者中血管显示率5级者占63．30％，4级者占36．73％。肾功能不良组患者中血管显示率4级者占41．03％，3级者占46．15％，2级者占10．30％，1级者占2．60％。③移植肾功能不良组患者阻力指数显著高于移植肾功能正常组（P〈0．01）。移植肾功能不良组患者移植肾功能恢复后阻力指数显著低于移植肾尚未恢复时（P〈0．01），其中99％以上的患者△（阻力指数）≥0.20。④界值阻力指数=0．75的诊断试验的敏感性、特异性和准确性最高，均达到100％。结论：当移植肾血管阻力指数升高至0．75以上，特别是同一患者自身对照升高超过0.2以上和或血管显示率低于4级，结合临床表现和生化结果，提示可能出现移植肾排斥反应。     

研究生一年级学生运动等级与其健康状况的相关性

目的:调查研究生一年级学生的体育锻炼和健康状况,并分析其相关性。方法:调查于2005-09/10完成。选取西南大学和重庆大学2005级研究生一年级学生作为调查对象,共发放问卷190份,男90份,女100份。进行问卷调查,当场收回问卷。问卷内容:①自测健康评定量表:由48个条目构成,1～17为自测生理健康评定子量表(170～0分),19～34为自测心理健康子量表(150～0分),35～47为自测社会健康子量表(120～0分),分数越高代表越健康。②体育活动等级量表:主要调查调查对象上1个月参加体育锻炼的运动量,运动量=强度×时间×频率,强度与频率从1～5等级分别计1～5分,时间从1～5等级分别计0～4分,故运动量最高分为100分,最低分为0分。结果:有效回收176份问卷进入结果分析。①不同性别调查对象在运动等级上的分布情况:研究生一年级男女新生的运动量水平都偏低(男生:31.80±23.19,女生:15.57±15.39),且性别对运动量有显著的主效应(P<0.01),女生在运动量上的得分显著偏低。②调查对象健康状况各维度与运动量的相关性:运动量与总体健康、生理健康、心理健康和社会健康都存在显著相关性(r=0.150～0.238,P<0.05～0.01),生理健康对运动量有显著的预测作用(P<0.05)。③不同运动量等级调查对象的健康量表得分:运动等级对生理健康有显著的主效应(P<0.01),随着运动量的增加,研究生一年级学生的生理健康水平不断提高。结论:研究生一年级学生的体育锻炼运动量与健康水平存在着明显的正相关,随着运动量的增加,生理健康、心理健康及社会健康水平均不断增加。     

Establishment of a system to standardize acceptability criteria for alanine aminotransferase activity in donated blood

A multilaboratory study was conducted to develop a system for standardizing alanine aminotransferase (ALT) acceptability criteria ("cutoffs") for donated blood. Without standardized cutoffs, each laboratory must develop its own cutoff, and this may not make optimal use of ALT testing to reduce transmission of non-A, non-B hepatitis (NANB). Defining an ALT acceptability criterion in absolute terms is necessary because relative cutoffs based on local donor populations may be affected by the prevalence of NANB in each community. This study involved 16 laboratories using 23 different analytic systems. The ALT results of the analysis of a plasma reference sample could be used to translate mathematically a single, absolute cutoff to units applicable to each analytic system. The distribution of ALT results in 1.4 million donations from across the country was established; basing the cutoff on this sample avoids the problems inherent in using a local donor base to establish a cutoff. We propose the implementation of a system to standardize ALT acceptability criteria to an activity level defined by analysis of a nationwide donor sample.