First-generation neuronal precursors in the crayfish brain are not self-renewing

Adult-born neurons in crayfish (Procambarus clarkii) are the progeny of 1st-generation precursor cells (functionally analogous to neuronal stem cells in vertebrates) that are located in a neurogenic niche on the ventral surface of the brain. The daughters of these precursor cells migrate along the processes of bipolar niche cells to proliferation zones in the cell clusters where the somata of the olfactory interneurons reside. Here they divide again, producing offspring that differentiate into olfactory local and projection neurons. The features of this neuronal assembly line, and the fact that it continues to function when the brain is isolated and perfused or maintained in organotypic culture, provide opportunities unavailable in other organisms to explore the sequence of cellular and molecular events leading to the production of new neurons in adult brains. Further, we have determined that the 1st-generation precursor cells are not a self-renewing population, and that the niche is, nevertheless, not depleted as the animals grow and age. We conclude, therefore, that the niche is not a closed system and that there must be an extrinsic source of neuronal stem cells. Based on in vitro studies demonstrating that cells extracted from the hemolymph are attracted to the niche, as well as the intimate relationship between the niche and vasculature, we hypothesize that the hematopoietic system is a likely source of these cells.     

儿童和青少年颞叶癫癎的术后长期疗效观察

目的总结儿童和青少年颞叶癫癎手术后的长期疗效和生活质量。方法回顾性分析31例儿童和青少年颞叶癫癎病人的临床资料,行标准前颞叶切除术26例,扩大前颞叶切除术2例,前颞叶切除术＋软化灶切除术2例,颞后顶下致癎灶切除术1例。评估术后癫癎发作改善情况及认知、生活质量等。结果术后随访5年以上,其中癫癎发作消失、达到EngelⅠ级26例,EngelⅡ级1例,EngelⅢ级2例,EngelⅣ级2例。术后病理示：海马组织硬化13例,皮质发育异常伴胶质增生9例,皮质发育异常伴海马组织硬化6例,神经元胶质肿瘤2例,继发性瘢痕脑回形成1例。术后并发症多数可恢复。结论儿童和青少年颞叶癫癎术后长期疗效良好,生活质量提高。     

Clinical characteristics and treatment responses in new-onset epilepsy in the elderly

PurposeEpidemiologic studies have shown that the incidence of epilepsy is the highest in the elderly population. Because the elderly constitutes the most rapidly growing population, epilepsy in this group is an important health issue worldwide. To identify the characteristics of epilepsy in the elderly, we reviewed our experience at a tertiary referral center in Japan.MethodsWe searched all electronic medical records of the past 6 years at the epilepsy clinic of the hospital affiliated to our University-affiliated hospital. We defined an elderly person as an individual aged 65 years and above. All patients underwent history and physical examinations, 3 T magnetic resonance imaging and/or computer tomography, and electroencephalogram (EEG). The diagnosis of epilepsy, age of onset, etiology, and antiepileptic medication were recorded.ResultsWe identified 70 patients who developed epilepsy after the age of 65 years. The mean age of seizure onset was 73.1 years and 52.9% patients were males. Complex partial seizures (CPS) without secondarily generalization (n = 33, 47.1%) were most frequent. The most frequent diagnosis was temporal lobe epilepsy (n = 50, 71.4%). Etiological diagnosis was possible in nearly 50% patients, including those with cerebrovascular disease. A clear cause of epilepsy was not found (i.e., non-lesional epilepsy) in 52.8% patients. Interictal EEG revealed focal epileptiform discharges in 72.9% (n = 51) patients. Of the 54 patients who were followed more than 1 year, 42 patients (77.8%) were on antiepileptic monotherapy and 52 patients (96.3%) had been seizure-free for more than 1 year.ConclusionThe most frequent diagnosis in our cohort of elderly persons with new-onset epilepsy was temporal lobe epilepsy. Non-lesional temporal lobe epilepsy was not uncommon. Epileptogenecity was relatively low in elderly patients and they responded well to antiepileptic medication.     

Validation of an Magnetic Resonance Imaging Acquisition and Review Protocol for Alzheimer's Disease and Related Disorders

PurposeMagnetic resonance imaging (MRI) of the brain allows for the identification of structural lesions typical of Alzheimer's disease (AD), the main cause of dementia. However, to have a clinical impact, it is imperative that acquisition and reporting of this MRI-based evidence be standardized, ensuring the highest possible reliability and reproducibility. Our objective was to validate a systematic radiological MRI acquisition and review process in the context of AD.MethodsWe included 100 individuals with a suspicion of dementia due to AD for whom MRI were acquired using our proposed protocol of clinically achievable acquisitions and used a unified reading grid to gather semi-quantitative evidence guiding diagnostic. MRIs were read by 3 raters with different experience levels. Interrater reliability was measured using Cohen's kappa statistic.ResultsInterrater reliability average for lesions occupying space, hemorrhage, or ischemia, was respectively 0.754, 0.715, and 0.501. Average reliability of white matter hyperintensity burden (Fazekas), global cortical atrophy, and temporal lobe atrophy (Scheltens) scales was 0.687, 0.473, and 0.621 (right)/0.599 (left), respectively. The kappas for regional cortical atrophy (frontal, parietal, occipital, temporal, and posterior cingulum) varied from 0.281–0.678. The average MRI reading time varied between 1.43-5.22 minutes.ConclusionsThe presence of space occupying lesions, hemorrhagic or ischemic phenomena, and radiological scales have a good interrater reproducibility in MRI. Coupled with standardized acquisitions, such a protocol should be used when evaluating possible dementias, especially those due to probable AD.     

Visual phenomena and anatomo-electro-clinical correlations in occipital lobe seizures

BackgroundOccipital lobe seizure are underrepresented in epilepsy surgery cases series. This may reflect the fear for post-surgical functional deficits but also the doubt about the ability of anatomo-electro-clinical correlations to localize precisely the epileptogenic zone in occipital lobe seizure.MethodsIn this expert opinion paper, we review first the general clinical characteristics of occipital lobe seizures, describe the repertoire of visual phenomena and oculo-motor signes in occipital seizures, describe inter-ictal and ictal EEG and finally the possible schemes of epileptogenic zone organization.ResultsVisual and oculo-motor semiology points towards occipital onset seizures but is neither pathognomonic nor constant. Eyes version and unilateral ictal discharge have a strong lateralizing value but inter-ictal spikes as well as eyes version can be falsely lateralizing.ConclusionAlthough visual and oculo-motor phenomena are characteristic of occipital lobe seizures, they may be discrete, overlooked and should therefore be carefully assessed. There are no clear electro-clinical correlations of a sublobar organization of occipital seizures but the clinical pattern of propagation might help to differentiate complex occipito-temporal from occipito-parietal initial epileptogenic network.     

肝叶切除联合胆肠内引流在肝内外胆管结石手术治疗中的应用分析

目的总结肝叶切除联合胆肠内引流治疗肝内外胆管结石的经验,评价其手术效果及其预后。方法收集安徽医科大学第一附属医院肝胆胰外科二病区2006年9月至2014年4月行肝叶切除联合胆肠内引流治疗肝内外胆管结石26例患者的临床资料,统计患者的性别、年龄、临床表现、既往胆道手术史、结石的分布、术式、术后并发症以及随访情况,以探讨近远期手术效果。结果平均住院时间19.73±7.14天,手术时间264.92±46.11分钟,术中失血量143.68±96.03 ml。术后出现胆漏4例(15.38%),胸腔积液8例(30.76%),切口感染3例(11.53%),脓毒血症1例(3.84%),即时结石清除率84.61%,23例病人获得1~9年随访,3例发现结石复发。结论肝叶切除联合胆肠内引流是治疗肝内外胆管结石的有效方法。其中,术中胆道镜判断Oddi’s括约肌功能为确定手术方式、减少术后结石复发的关键因素。     

腹腔镜治疗肝右叶癌的疗效分析

目的：探讨腹腔镜治疗肝右叶癌的疗效。方法2011年6月—2014年9月我院对78例肝右叶癌行手术治疗,其中18例行全腹腔镜肝癌切除术,60例行开腹肝癌切除术。比较两组患者的手术时间、术中出血量、术后住院时间、术后并发症发生率、术后一年生存率。结果腹腔镜组手术时间为（348．8±98．8）min,长于开放手术组,差异具有统计学意义（P ＜0．05）;腹腔镜组术中出血量、术后住院时间、术后并发症发生率均少于开放手术组,相比差异具有统计学意义（P ＜0．05）;两组患者术后1年复发率及生存率比较未见统计学意义（P ＞0．05）。结论腹腔镜治疗肝右叶癌手术难度大,但相比开腹手术,腹腔镜肝右叶癌切除术具有术中出血量少、术后住院时间短、术后并发症发生率低的优点。     

fMRI evaluation of hemispheric language dominance using various methods of laterality index calculation

Several functional MR imaging studies evaluating the lateralisation of linguistic functions in patients who underwent Wada testing have been reported. There is extensive variance in the Laterality index (LI) calculation across the studies, and the optimal calculation method remains unclear. We attempted to calculate the LI in different ways in the same subjects, in order to find the LI calculation method with the highest correlation to the Wada test. Fifteen patients (10 females, 5 males) suffering from medically intractable temporal lobe epilepsy (TLE) (12 left, 3 right) were admitted for the study. The patients underwent a standardized bilateral intracarotid short-acting barbiturate test. Language testing included spontaneous speech, oral comprehension, reading, object and picture naming, and repetition. All the tasks were scored separately in order to increase the possibility of correlation between Wada and LI. A silent phonemic verbal fluency task (VFT) was used as a language paradigm for functional measurement. Regions of interest (ROIs), with a known association with language function (Broca’s area, the lateral prefrontal cortex, etc.), were defined. First, the LIs were calculated from the ROIs using a previously reported method (simple suprathreshold count). Next, we used several new methods of LI calculation (t–weighting of voxels, methods independent of the choice of the statistical threshold, etc.) The most significant correlation with Wada was proven in the LIs that were evaluated from Broca’s area (up to R = 0.94, P = 1 × 10⁻⁷). However, the new LI calculation methods used in the present study did not produce a statistically significant benefit in comparison to previously reported methods.     

Cue and reward signals carried by monkey entorhinal cortex neurons during reward schedules

Ablation of entorhinal/perirhinal cortices prevents learning associations between visual stimuli used as cues in reward schedules and the schedule state. Single neurons in perirhinal cortex are sensitive to associations between the cues and the reward schedules. To investigate whether neurons in the entorhinal cortex have similar sensitivities, we recorded single neuronal activity from two rhesus monkeys while the monkeys performed a visually cued reward schedule task. When the cue was related to the reward schedules, the monkeys made progressively fewer errors as the schedule state became closer to the reward state, showing that the monkeys were sensitive to the cue and the schedule state. Of 75 neurons recorded in the entorhinal cortex during task performance, about 30% responded. About half of these responded after cue presentation. When the relation of the cue to the reward schedules was random, the cue-related responses disappeared or lost their selectivity for schedule states. The responses of the entorhinal cortex neurons are similar to responses of perirhinal cortex neurons in that they are selective for the associative relationships between cues and reward schedules. However, they are particularly selective for the first trial of a new schedule, in contrast to perirhinal cortex where responsivity to all schedule states is seen. A different subpopulation of entorhinal neurons responded to the reward, unlike perirhinal neurons which respond solely to the cue. These results indicate that the entorhinal signals carry associative relationships between the visual cues and reward schedules, and between rewards and reward schedules that are not simply derived from perirhinal cortex by feed-forward serial processing.