电刺激小脑顶核对持续局灶性脑缺血时钙蛋白酶活性的影响

目的观察电刺激小脑顶核(FN)对持续局灶性脑缺血钙蛋白酶活性的影响,以阐明其神经保护作用机制。方法健康雄性Wistar大鼠,随机分为假手术组(PO)、FN刺激假手术组(PO-FN)、持续缺血组(PI)及持续缺血-FN刺激组(PI-FN),后两组又分为缺血1,3,6,12及24h组。建立大鼠电刺激FN及持续局灶性脑缺血模型,应用Western印迹半定量各组缺血核心区Mr=150000FBDP含量(表示钙蛋白酶活性),并应用尼氏体染色对缺血核心区神经元数量及形态进行分级评分。结果PO组及PO-FN组钙蛋白酶活性相似(P>0.05),处于低水平。PI组钙蛋白酶活性从缺血1h犤(3670±600)A/μg总蛋白犦开始即显著增高(t=6.338,P<0.001),以后随着缺血时间延长,钙蛋白酶活性不断增高,直至缺血24h犤(9180±360)A/μg总蛋白犦仍有持续增高趋势(缺血12,24h,t=14.673,16.632,P<0.001)。PI-FN组随着缺血时间的延长,钙蛋白酶活性从缺血1h犤(2510±460)A/μg总蛋白犦也开始增高,以后随着缺血时间延长,钙蛋白酶活性不断增高,但各时点组与其相应PI组相比,其增高程度明显减低,差别具有显著意义(缺血1,24h,t=1.875,2.134,P<0.05)。PO组及PO-FN组神经元形态及数量正常,评分均为0分。PI组从缺血1h(0.8±0.3)开始,神经元形态、数量即出现轻度改变,其评分增高(z=2.443,P<0.01),以     

小脑顶核电刺激治疗小儿中枢性协调障碍的研究

目的：探讨小脑顶核电刺激治疗在小儿中枢性协调障碍康复治疗中的优势。方法选取2012年8月至2013年7月收治的84例中枢性协调障碍患儿随机分为观察组（42例）和对照组（42例）,对照组仅采用常规康复综合治疗,观察组在此基础上加用小脑顶核电刺激疗法,对两组患儿治疗后总有效率及Gesell发育量表动作能之发育商（DQ）进行比较。结果观察组显效率（83.33%）高于对照组（57.14%）,治疗后DQ评分观察组[（84.91±7.28）分]明显高于对照组[（71.97±5.74）分],差异均有统计学意义（P〈0.05）。结论常规康复治疗联合小脑顶核电刺激治疗小儿中枢性协调障碍疗效显著。     

Endocrine correlates of the breeding asynchrony between two Corsican populations of blue tits (Parus caeruleus)

Analyses of the development of the reproductive system in seasonally breeding birds in the framework of long-term ecological studies are rare. Here, we present the first results of such a study in two Corsican populations of a European passerine bird, the blue tit (Parus caeruleus). The two study populations occupy different oak habitats and are separated by only 25 km. Despite their close proximity, they show a one-month difference in onset of egg laying, even after controlling for altitude. This micro-geographic difference in breeding date appears adaptive because both study populations raise chicks when food is most plentiful. In our study, males reached their maximum song activity during the egg-laying stage while maximal testosterone levels and testes sizes were reached 2-3 weeks before egg laying. The rate of development of the reproductive system in males was much faster in the earlier population, in spite of a similar onset of gonad development and song activity for the two study populations. No change in the volume of the song-control nuclei (HVC and RA) could be detected during the study period. Development of brain nuclei was completed 2-3 months before the beginning of intense sexual activity.     

Geographic, seasonal, and precipitation chemistry influence on the abundance and activity of biological ice nucleators in rain and snow

Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than −10 °C). We examined the concentration (per volume of liquid) and nature of IN in precipitation collected from Montana and Louisiana, the Alps and Pyrenees (France), Ross Island (Antarctica), and Yukon (Canada). The temperature of detectable ice-nucleating activity for more than half of the samples was ≥ −5 °C based on immersion freezing testing. Digestion of the samples with lysozyme (i.e., to hydrolyze bacterial cell walls) led to reductions in the frequency of freezing (0–100%); heat treatment greatly reduced (95% average) or completely eliminated ice nucleation at the measured conditions in every sample. These behaviors were consistent with the activity being bacterial and/or proteinaceous in origin. Statistical analysis revealed seasonal similarities between warm-temperature ice-nucleating activities in snow samples collected over 7 months in Montana. Multiple regression was used to construct models with biogeochemical data [major ions, total organic carbon (TOC), particle, and cell concentration] that were accurate in predicting the concentration of microbial cells and biological IN in precipitation based on the concentration of TOC, Ca²⁺, and NH₄⁺, or TOC, cells, Ca²⁺, NH₄⁺, K⁺, PO₄³⁻, SO₄²⁻, Cl⁻, and HCO₃⁻. Our results indicate that biological IN are ubiquitous in precipitation and that for some geographic locations the activity and concentration of these particles is related to the season and precipitation chemistry. Thus, our research suggests that biological IN are widespread in the atmosphere and may affect meteorological processes that lead to precipitation.     

Clinical and Pathological Features of Korean Patients with DNM2-Related Centronuclear Myopathy

Background and Purpose

Centronuclear myopathy (CNM) is characterized by the presence of central nuclei within a large number of muscle fibers. Mutations of the dynamin 2 gene (DNM2) are common causes of autosomal dominant or sporadic CNM. The aim of this study was to characterize the clinical and pathological features of CNM relative to the presence of DNM2 mutations.

Methods

Six patients with clinical and pathological features of CNM were recruited. Detailed clinical and pathological findings were analyzed according to the presence of DNM2 mutations.

Results

We detected DNM2 mutations in four of the six sporadic CNM patients, and identified the following distinct clinical and pathological features in those patients with DNM2 mutations: preferential involvement of the distal lower limbs, typical nuclear centralization, and radially distributed sarcoplasmic strands in muscle pathology. In contrast, those without DNM2 mutations exhibited rather diffuse muscular involvement, and nuclear internalization and myofibrillar disorganization were more pronounced features of their muscle pathology.

Conclusions

These findings suggest the presence of specific features in Korean CNM patients. A detailed clinical and pathological examination of CNM patients would be helpful for molecular genetic analyses of this condition.     

Control over a stressor involves the posterior dorsal striatum and the act/outcome circuit

Controllable/escapable tailshocks (ESs) do not produce the behavioral and neurochemical outcomes produced by equal yoked uncontrollable/inescapable tailshocks (ISs). The prelimbic cortex is known to play a key role in mediating the protective effects of control. The concepts of act/outcome learning and control seem similar, and act/outcome learning is mediated by a circuit involving the prelimbic cortex and posterior dorsomedial striatum (DMS). Thus, we tested the involvement of the DMS in the protective effect of ES, in rats. First, we examined Fos immunoreactivity in both the DMS and dorsolateral striatum (DLS) after ES and yoked IS. We then investigated the effect of blocking DMS or DLS N‐methyl‐d ‐aspartate receptors with the specific antagonist D‐(‐)‐2‐amino‐5‐phosphopentanoic acid (D‐AP5) on the release of dorsal raphe nucleus serotonin (5‐HT) during ES, as well as on the level of anxiety produced by the ES experience 24 h later. ES, but not yoked IS, produced a large increase of Fos activity in the DMS. Consistent with the Fos data, D‐AP5 in the DMS, but not in the DLS, prevented the inhibition of dorsal raphe nucleus 5‐HT release normally produced by ES. Furthermore, D‐AP5 administered into the DMS before ES, but not into the DLS, increased anxiety 24 h later, leading to levels similar to those produced by IS. These results suggest that, as with appetitive act/outcome contingency learning, the protective effects of behavioral control over a stressor require the DMS.     

早期帕金森病相关脑结构的定量磁化率成像

目的 应用3T磁共振T1加权成像和定量磁化率成像分析早期帕金森病（PD）患者深部灰质核团体积的变化,探究深部灰质核团磁化率值在帕金森病患者和健康对照者之间的差异,探讨磁化率值在早期PD诊断中的意义,以及定量磁化率成像对于黑质小体-1的显示情况。方法 30例早期PD患者和27例年龄、性别、教育程度匹配的健康对照者,分割双侧尾状核、壳核、苍白球、黑质和红核,测量核团的体积和平均磁化率值,使用SPSS 20.0软件对数据进行统计学分析,并对磁化率值进行逻辑回归。结果 早期PD患者组和健康对照组上述核团标准化体积之间差异无显著性;早期PD患者组右侧苍白球、左侧黑质和右侧黑质的磁化率值显著高于健康对照组（P<0.05）;上述核团磁化率值经逻辑回归变换后得到的受试者工作特征曲线下面积为0.93;在21例健康对照者和1例早期PD患者的定量磁化率图像上看到了黑质小体-1。结论 定量磁化率图像在诊断早期PD中具有很高的应用价值;大部分健康对照者的黑质小体-1在定量磁化率图像上可以显示,但更精确的研究需要<1mm分辨率的定量磁化率图像。     

Spinal interneuron circuits reduce approximately 10-Hz movement discontinuities by phase cancellation

Tremor imposes an important limit to the accuracy of fine movements in healthy individuals and can be a disabling feature of neurological disease. Voluntary slow finger movements are not smooth but are characterized by large discontinuities (i.e., steps) in the tremor frequency range (approximately 10 Hz). Previous studies have shown that these discontinuities are coherent with activity in the primary motor cortex (M1), but that other brain areas are probably also involved. We investigated the contribution of three important subcortical areas in two macaque monkeys trained to perform slow finger movements. Local field potential and single-unit activity were recorded from the deep cerebellar nuclei (DCN), medial pontomedullary reticular formation, and the intermediate zone of the spinal cord (SC). Coherence between LFP and acceleration was significant at 6 to 13 Hz for all areas, confirming the highly distributed nature of the central network responsible for this activity. The coherence phase at 6 to 13 Hz for DCN and pontomedullary reticular formation was similar to our previous results in M1. By contrast, for SC the phase differed from M1 by approximately π rad. Examination of single-unit discharge confirmed that this was a genuine difference in neural spiking and could not be explained by different properties of the local field potential. Convergence of antiphase oscillations from the SC with cortical and subcortical descending inputs will lead to cancellation of approximately 10 Hz oscillations at the motoneuronal level. This could appreciably limit drive to muscle at this frequency, thereby reducing tremor and improving movement precision.     

Surgical treatment of unstable pelvic fracture in children: Long term results

Paediatric pelvic fractures are rare lesions. In the literature still controversy exists regarding the management of these injuries. The sequelae of these types of lesions has been described. We report the management and long term outcome of 8 patients with paediatric pelvic fractures treated in our institution. Associated injuries to the Risser's growth nuclei are described that has not been previously reported. Anatomical reduction of the displaced fracture should be considered to minimise the risk of long term functional impairment.     

Lesions of reuniens and rhomboid thalamic nuclei impair radial maze win‐shift performance

The reuniens (Re) and rhomboid (Rh) nuclei are major sources of thalamic input to hippocampus and medial prefrontal cortex. We compared effects of lesions in ReRh and other parts of the midline‐intralaminar complex on tasks affected by lesions in terminal fields innervated by these nuclei, including: visuospatial reaction time (VSRT), a measure of sensory guided responding; serial VSRT, a measure of action sequence learning; and win/shift radial arm maze (RAM) measures of spatial memory. ReRh lesions affected RAM, but not VSRT or serial VSRT performance. The effects of caudal intralaminar lesions were doubly dissociated from ReRh lesions, affecting VSRT, but not RAM or serial VSRT performance. Rostral intralaminar lesions did not produce significant impairments, other than a subgroup with larger lesions that were impaired performing a delayed RAM task. Combined lesions damaging all three sites produced RAM deficits comparable to ReRh lesions and VSRT deficits comparable to caudal intralaminar lesions. Thus there was no indication that deficits produced by lesions in one site were exacerbated significantly by the cumulative effect of damage in other parts of the midline‐intralaminar complex. The effects of ReRh lesions provide evidence that these nuclei affect memory functions of hippocampus and medial prefrontal cortex. The double dissociation observed between the effects of ReRh and caudal intralaminar nuclei provides evidence that different nuclei within the midline‐intralaminar complex affect distinct aspects of cognition consistent with the effects of lesions in the terminal fields they innervate. © 2010 Wiley‐Liss, Inc.