Mating-type loci segregate aberrantly in Phytophthora infestans but normally in Phytophthora parasitica: implications for models of mating-type determination

In the oomycete, Phytophthora infestans, mating type is determined by a locus that segregates in a non-Mendelian manner consistent with its linkage to a system of balanced lethals. The significance of this unusual phenomenon was addressed by studying the segregation patterns of DNA markers linked to mating type in the related species, P. parasitica. This was done using loci identified by either RAPD analysis of P. parasitica crosses or by cross-hybridization with RFLP markers linked to mating type in P. infestans. The resulting data revealed that, unlike P. infestans, mating type in P. parasitica was regulated by a locus displaying Mendelian segregation. An improved model for mating-type determination in Phytophthora is presented. Received: 21 October 1996 / 7 April 1997     

肝硬化患者的脑电活动地形图

对２０例无临床肝性脑病的失代偿期肝硬化患者进行脑电活动地形图（ＢＥＡＭ）检查，并与３３例正常人作对照，以探讨亚临床肝性脑病（ＳＨＥ）的诊断价值。结果表明，２０例肝硬化患者中，ＢＥＡＭ正常５例，轻度异常５例，轻￣中度异常５例，中度异常５例，总异常率为７５％（１５／２０）。ＢＥＡＭ异常的分布特点以弥漫性分布为主要表现，主要为慢频域（δ．θ．δ＋θ／α＋β）活动增强，Ｚ值增高，只有３例波及α频域。提示：     

中国西部城市和农村开展面粉营养素强化的可行性分析

目的通过对甘肃农产区居民的饮食习惯、营养知识和态度的调查,从需方的角度对开展面粉营养素强化的可行性进行探讨。方法采用定性和定量调查相结合的方法,对4个地区的城市和农村的男性和女性分别进行现状和原因的调查分析。结果被调查地区多数城市(92.7%)和农村(60.7%)家庭日常饮食以面食为主,94.7%的城市家庭购买面粉,而在农村地区,多数家庭自己种植或购买小麦。城市居民较农村对营养和维生素有更多的了解和关注。农村男性对面粉营养素强化持怀疑态度,女性更加关注孩子的营养,认为目前的饮食单一,孩子可能营养不足。结论与农村地区相比,城市地区的社会经济条件和知识基础较利于开展面粉强化工作。     

Reversible reorganisation of the motor cortical representation of the hand in cervical dystonia.

Previous work has suggested that there may be a widespread disturbance of motor control mechanisms in patients with cervical dystonia. In the present study, we used transcranial magnetic stimulation to investigate the topography of the corticomotor projection to the abductor pollicis brevis (APB) muscle in 10 subjects with idiopathic torticollis. Threshold-adjusted stimuli were delivered at multiple scalp sites during a low-level voluntary contraction of the APB, and maps were generated of motor evoked potential amplitude versus scalp site. The cortical maps for the APB on the side opposite to the direction of head rotation were displaced laterally or posteriorly in all subjects and reverted to a more normal position after botulinum toxin injection of the cervical muscles in 5 subjects. The findings point to a reversible reorganisation of the corticomotor representation of the hand on the same side as the sternocleidomastoid (SCM) muscle that is involved in producing the dystonia. These results provide further evidence for the involvement of cortical centres and for a more widespread abnormality of motor control mechanisms in focal dystonia. The findings also support the notion that head turning is chiefly mediated by the hemisphere ipsilateral to the direction of the head rotation by means of a corticomotor projection to the contralateral SCM.     

Topographical analysis of the EEG effects of a subconvulsive dose of lidocaine in healthy volunteers

Background: The purpose of the present study was to assess the effects of intravenous lidocaine on spatial changes of electroen-cephalographic power and on psychomotoric status in conscious volunteers.
Methods: In 11 healthy volunteers lidocaine (2-min bolus, 100 mg; 15-min infusion, 40 μg kg^-1 min^-1) or placebo were given intravenously in a randomized, single-blinded, two-way crossover study. Haemodynamics and lidocaine plasma concentrations were measured at baseline and within a period of 30 min following bolus injection. Vigilance and emotional status were tested using visual analogue scales (VAS). Toxic CNS effects were evaluated by a questionnaire. The raw EEG (17 leads, reference C_z) and computed power spectra were continuously recorded.
Results: The chosen lidocaine dosage led to nearly constant plasma concentrations (unbound lidocaine 2.5 min and 15 min after bolus 0.36±0.14 μg/ml and 0.30±0.06 μg/ml, respectively [mean±SD]). The placebo caused no symptoms, changes in VAS-scores or EEG-parameters. Lidocaine induced pronounced subjective symptoms and significant increases in delta activity for 15 min, most dominant at the frontotemporal and occipital leads (max. +219% O₁). Frontal and occipital beta1 and beta2 power (max. +131% and +124% at O₁, respectively) was immediately increased after the bolus injection. No EEG changes occurred at central region C_z, and no interhemispheric EEG differences were noted. Theta, alphal, and alpha2 power remained unchanged.
Conclusion: The current data demonstrate simultaneous changes in psychomotoric status as well as delta and beta spectral power during lidocaine infusion. These data could be an indication that the pronounced frontotemporal and occipital EEG changes are the electroencephalographic expression of subjective sensations.     

The Cutaneous Microcirculation: Ultrastructure and Microanatomical Organization

The cutaneous microcirculation is organized as two horizontal plexuses. One is situated 1–1.5 mm below the skin surface, and the other is at the dermal-subcutaneous junction. Ascending arterioles and descending venules are paired as they connect the two plexuses. From the upper layer, arterial capillaries arise to form the dermal papillary loops that represent the nutritive component of the skin circulation. There are sphincter-like smooth muscle cells at the point where the ascending arterioles divide to form the arteriolar component of the upper horizontal plexus. At the dermal subcutaneous junction, there are collecting veins with 2-cusped valves that are oriented to prevent the retrograde flow of blood. Laser Doppler flowmetry (LDF) has demonstrated vasomotion of red cell flux localized to the sites of ascending arterioles. The simultaneous recording by LDF of red cell flux and the concentration of moving red blood cells from individual sites allows one to construct by computer topographic maps of these two valves. The two maps, based on initial studies using correlative skin biopsy specimens, can define 1-mm³ volumes of skin that are predominantly arteriolar in composition, predominantly venular in composition, or essentially devoid of all microvascular elements. The electron and light microscopic features that define the microvascular segments, when coupled with the ability of LDF to define the predominant microvascular segments under the probe, will allow one to study both the mechanisms of normal physiological states and the pathogenetic mechanisms underlying pathological skin disorders in which the microvasculature plays a predominant role.     

潍坊市出境劳务人员艾滋病防治知识需求分析

目的为了解外出劳务人员对艾滋病知识的需求和接受程度。方法对外出劳务人员艾滋病防治知识知晓率进行抽样调查。结果艾滋病防治知识平均知晓率为60.75%。讨论调查对象对艾滋病知识及检测有很大的需求,对艾滋病防治知识和无偿献血基本知识相当缺乏,有待于继续加强宣传教育工作。     

Functional magnetic resonance imaging in schizophrenia: cortical response to motor stimulation

Previous functional magnetic resonance imaging (fMRI) studies suggest that motor system abnormalities are present in schizophrenia. However, these studies have often produced conflicting or ambiguous findings. The purpose of this study was to ascertain whether activation differences could be identified in stable schizophrenic patients on the basis of BOLD measures in two motor regions, the primary motor cortex, Brodmann area 4 (BA4) and the premotor and supplementary motor area, Brodmann area 6 (BA6). Twenty-one schizophrenic patients and 21 healthy control subjects were studied with BOLD fMRI methods during a sequential finger tapping task. Statistical parametric maps were generated for each subject, and anatomic regions were automatically defined using an anatomic atlas. Compared with controls, the schizophrenic patients showed a significant reduction in contralateral activation for both BA4 and BA6 (P<0.001), and in ipsilateral activation in BA4 (P=0.007) and BA6 (P=0.002). In healthy controls, the coactivation in the ipsilateral cortex is reduced in comparison with the contralateral cortex for right and left handed tasks. In BA4, this reduction is significant for right (P=0.007) and left (P=0.003) finger tapping. Similar results were obtained for BA6. Further analyses are necessary to evaluate the activation in other motor system regions.     

参加新婚教育人群对紧急避孕的知识、态度和实践

为探讨新婚前后人群对避孕方法(特别是紧急避孕方法)的知识、态度和使用以及新婚前后人群对紧急避孕的需求及对推广EC的意愿的建议。采用描述性流行病学研究方法,以郑州市新婚学校为研究现场,直接收集第一手数据。采用EPI INF6.04软件包,和SPSS7.5 FOR WINDOW95软件包,进行数据处理、统计与分析。统计分析的主要指标有:频数分布,单因素分析,logistic多元回归分析等。结果平均年龄26.41岁,女性占49.4％。在第一次同房时,仅有46.4％的人使用过避孕方法。第一次同房时最常用的避孕方法是避孕套(76.1％)。在女性应答者中,25岁以下开始同房者占76.6％,有9.3％的人有过人工流产史。88.2％的人每周有1～6次同房。有43.2％的人听说过EC方法,有35.9％的人听说过紧急避孕片,有29.9％的人知道使用EC片有时间限制,有24.7％的人听说过上环可作为紧急避孕方法,有17.4％的人知道上环紧急避孕方法有时间限制。仅有12.9％的人使用过某种事后避孕方法,其中有事后3天内使用者占82.0％。92.6％的人赞成开展EC教育。73.7％的人认为,应在未婚青少年中开展EC教育。80.7％的人认为,在本单位进行EC教育是可行的。应答者认为,最易的接受的EC教育形式依次为:阅读材料(40.4％),录相(20.6％)和讲课(15.7％)。认为EC的最可靠的信息来源     

病例教学联合思维导图在病理生理学教学中的应用

目的　评价病例教学联合思维导图在病理生理学教学中的应用效果,为提高病理生理学教学质量提供依据。方法　选取首都医科大学燕京医学院2017级本科生124名学生作为研究对象,分为试验组60人和对照组64人。其中,对照组采用传统教学,试验组采用课上病例教学联合课后思维导图的教学方式。课程结束后通过云班课平时成绩和试卷成绩对教学效果进行评价。采用SPSS 17.0进行Wilcoxon秩和检验和Welch’s correction t检验。结果　试验组学习的积极性得到了有效的调动（P<0.001）、知识的理解力也优于对照组（P=0.020）。试验组的平均理论成绩优于对照组（P=0.036）,主要表现为客观题成绩高于对照组（P<0.001）及简答和论述题成绩高于对照组（P=0.006）,名词解释成绩差异无统计学意义（P=0.302）。结论　病例教学联合思维导图可显著提高病理生理学的教学质量。