双语脑语言转换和语言代表区的术中直接电刺激研究（附2例分析）

目的通过对双语病人进行术中直接电刺激研究,探讨参与双语过程的脑结构。方法对2例左额叶低级别胶质瘤汉-英双语病人在术中唤醒麻醉下进行中文、英文以及双语转换任务的脑定位,依据功能边界切除肿瘤。评价术前、术后语言功能。结果2例病人均定位出Broca区,无语种特异性,但两种语言的命名阳性点是分离的：在前额叶背外侧区发现负责双语转换的阳性点,并在皮质下找到相应的特异性纤维;电刺激尾状核头表现为双语转换障碍。术后MRI显示肿瘤全切除。术后语速减慢1例,另1例自发言语减少．3个月后均恢复,未遗留语言转换障碍。结论大脑存在负责语言转换的脑结构。在实施语言功能区定位手术时,应对每种语言及其转换进行监测。     

Atypical performance patterns on Delis–Kaplan Executive Functioning System Color–Word Interference Test: Cognitive switching and learning ability in older adults

Introduction: Cognitive set shifting requires flexible application of lower level processes. The Delis–Kaplan Executive Functioning System (DKEFS) Color–Word Interference Test (CWIT) is commonly used to clinically assess cognitive set shifting. An atypical pattern of performance has been observed on the CWIT; a subset of individuals perform faster, with equal or fewer errors, on the more difficult inhibition/switching than the inhibition trial. This study seeks to explore the cognitive underpinnings of this atypical pattern. It is hypothesized that atypical patterns on CWIT will be associated with better performance on underlying cognitive measures of attention, working memory, and learning when compared to typical CWIT patterns. Method: Records from 239 clinical referrals (age: M = 68.09 years, SD = 10.62; education: M = 14.87 years, SD = 2.73) seen for a neuropsychological evaluation as part of diagnostic work up in an outpatient dementia and movement disorders clinic were sampled. The standard battery of tests included measures of attention, learning, fluency, executive functioning, and working memory. Analyses of variance (ANOVAs) were conducted to compare the cognitive performance of those with typical versus atypical CWIT patterns. Results: An atypical pattern of performance was confirmed in 23% of our sample. Analyses revealed a significant group difference in acquisition of information on both nonverbal (Brief Visuospatial Memory Test–Revised, BVMT–R total recall), F(1, 213) = 16.61, p < .001, and verbal (Hopkins Verbal Learning Test–Revised, HVLT–R total recall) learning tasks, F(1, 181) = 6.43, p < .01, and semantic fluency (Animal Naming), F(1, 232) = 7.57, p = .006, with the atypical group performing better on each task. Effect sizes were larger for nonverbal (Cohen’s d = 0.66) than verbal learning (Cohen’s d = 0.47) and semantic fluency (Cohen’s d = 0.43). Conclusions: Individuals demonstrating an atypical pattern of performance on the CWIT inhibition/switching trial also demonstrated relative strengths in semantic fluency and learning.     

医学动态影像平台建设与应用

首先提出手术示教系统现存的问题,然后介绍医学动态影像的范围及统一管理的必要性,提出医学动态影像管理的平台解决方案,以中日友好医院继教需求为例,简单介绍该方案的实际应用情况及未来的发展。     

基于先进制造平台的假肢接受腔计算机辅助制造系统**☆

目的：为了克服手工制作假肢接受腔的缺点,将计算机辅助制造技术用于加工假肢接受腔,提高接受腔的质量和加工效率,减少对操作者知识和经验的要求。方法：基于先进制造平台建立假肢接受腔计算机辅助制造系统,进行系统的硬件设计和软件实现。先进制造平台的主要部件包括工控机,运动控制卡,松下全数字交流伺服控制系统,丝杠导轨,铣刀主轴电机,变频器,开关电源,限位开关及接近开关。软件主要包括参数设置、测试机器及开始加工3个功能模块。通过设置不同的指令脉冲输入和驱动器参数,调试出不同的电机转速。结果：实验结果显示,电机不仅有着自我保护的最高转速限制,而且即使在极低速运转的情况下,电机的运转现象仍然非常平稳,不会出现振动现象,更符合假肢接受腔的加工特点,可以加工出满足残疾人需要的高质量假肢接受腔。结论：基于先进制造平台的假肢接受腔计算机辅助制造系统可以克服手工制作的缺点,确保产品质量,降低成本。可以把优秀假肢制作师长期积累的经验编入计算机设计程序,减少对操作者知识和经验的要求,提高假肢接受腔一次制作成功率,降低接受腔的质量不确定性,从根本上改变了过去依靠手工设计、测量、取型、修型等落后的生产模式。关键词：先进制造平台;假肢接受腔;计算机辅助制造系统     

Switching between abstract rules reflects disease severity but not dopaminergic status in Parkinson's disease

This study sought to disambiguate the impact of Parkinson's disease (PD) on cognitive control as indexed by task set switching, by addressing discrepancies in the literature pertaining to disease severity and paradigm heterogeneity. A task set is governed by a rule that determines how relevant stimuli (stimulus set) map onto specific responses (response set). Task set switching may entail reconfiguration in either or both of these components. Although previous studies have shown that PD patients are impaired at switching between stimuli, in the present study not all patients were impaired at switching entire task sets, that is, both stimulus and response sets: compared with controls, patients with unilateral signs (Hoehn & Yahr Stage I) demonstrated intact switching, even following withdrawal from dopaminergic medication, while bilaterally affected Stage II patients were impaired. The parametric measure of Unified Parkinson's Disease Rating Scale (UPDRS) score predicted increasing switch costs within the patient group. These findings suggest that switching entire task sets may be a function of extrastriatal, possibly non-dopaminergic pathology which increases as the disease progresses.     

Role of the basal ganglia in switching a planned response

The ability to perform an appropriate response in the presence of competing alternatives is a critical facet of human behavioral control. This is especially important if a response is prepared for execution but then has to be changed suddenly. A popular hypothesis of basal ganglia (BG) function suggests that its direct and indirect pathways could provide a neural mechanism to rapidly switch from one planned response to an alternative. However, if one response is more dominant or 'automatic' than the other, the BG might have a different role depending on switch direction. We built upon the pro- and antisaccade tasks, two models of automatic and voluntary behavior, respectively, and investigated whether the BG are important for switching any planned response in general, or if they are more important for switching from a more automatic response to a response that is more difficult to perform. Subjects prepared either a pro- or antisaccade but then had to switch it unexpectedly on a subset of trials. The results revealed increased striatal activation for switching from a pro- to an antisaccade but this did not occur for switching from an anti- to a prosaccade. This activation pattern depended on the relative difficulty in switching, and it was distinct from frontal eye fields, an area shown to be more active for antisaccade trials than for prosaccade trials. This suggests that the BG are important for compensating for differences in response difficulty, facilitating the rapid switching of one response for another.     

The effects of psychotomimetics and psychomotor stimulants on two schedules promoting response switching in the rat

Abstract Rationale. Psychosis and psychotomimetic drugs result in a disorganisation of the structure of thought and behaviour. Normalising these is one of the objects of antipsychotic therapy, and methods for predicting such a therapeutic effect would be of value. Objective. The effects of a number of psychotomimetic agents were examined on the way in which rats distributed responding over two response levers using two different procedures, to assay their effects on behavioural organisation. Previously, amphetamine has been found to increase response switching using these schedules. Methods. In the first, the random reinforcement procedure, one of the two levers was selected at random as "correct", and responses on this lever were reinforced with food under a random ratio schedule. No signal was given to distinguish the levers. Responding could also result in the food tray being illuminated, but no food pellet was delivered ("no-food" event). Responses on the second lever ("incorrect") had no programmed consequences. After each food delivery or "no-food" event the levers designated as "correct" and "incorrect" were reassigned at random, and the rat had to open the food tray to restart the schedule. In the second procedure, the rats were required to make 21 responses before a switch between the two levers resulted in food delivery [Fixed Ratio (FR) 21-switch]. The responses making up the FR could be distributed freely between the two levers. Results. Phencyclidine (PCP), scopolamine, caffeine and ethanol increased switching under the random reinforcement procedure, but (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) and atropine did not. PCP, caffeine, lysergic acid diethylamide (LSD) and atropine increased switching under the FR21-switch procedure, but ethanol did not. The increases in switching produced by PCP, LSD and the anticholinergics were accompanied by marked reductions in response rate, whereas those produced by amphetamine and caffeine were not. The effects of amphetamine, and PCP were strongly dependent on the baseline probability of switching, those of atropine and caffeine moderately so, and those of LSD and ethanol only weakly so. Conclusions. Of the agents tested, psychomotor stimulants appear to produce the most selective increases in switching. The procedures described here may be useful for assaying the disorganisation of behaviour produced by other psychotomimetics and may have value in the detection of novel antipsychotic drugs. Electronic Publication     

Val-Tyr as a natural antihypertensive dipeptide can be absorbed into the human circulatory blood system

1. Intact absorption of the bioactive dipeptide Val-Tyr (VY), with in vivo antihypertensive ability in normotensive human subjects, was investigated. 2. As a result of a single oral administration of VY, the VY absorption curve occurred maximally over the second hour postprandially; a greater than 10-fold higher increment of VY following a dose of 12 mg was observed in the plasma at 2 h compared with the baseline concentration of VY at 0 h (1934 +/- 145 vs 159 +/- 11 fmol/mL plasma, respectively). 3. Plasma VY levels increased with dose administered (3, 6 and 12 mg), suggesting that exogenous VY could be absorbed intact into the human blood depending on the dose. The elimination half time (t1/2) of VY was estimated to be 3.1 h. The area under the curve for the 12 mg VY dose was 9185 +/- 688 fmol small middle doth/mL plasma.