Comparison of Marker Intervals and Number of Sib Pairs Used for Linkage Analysis on Simulated Nuclear Family Data

Using a two‐stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman‐Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5‐, 10‐, and 15‐cM intervals, were examined in the first‐stage scan. We found that the 10‐cM interval appears to be the most cost‐effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second‐stage scan at 1‐cM intervals for those putative positive regions identified in the first‐stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome‐wide scan at a 10‐cM interval and found that power decreases nonlinearly as the number of sib pairs decreases. © 2001 Wiley‐Liss, Inc.     

Development of specificity in corticospinal connections by axon collaterals branching selectively into appropriate spinal targets

Corticospinal projections in adult rodents arise exlusively from layer V neurons in the sensorimotor cortex. These neurons are topographically organized in their connections to spinal cord targets. Previous studies in rodents have shown that the mature distribution pattern of corticospinal neurons develops during the first 2 weeks postnatal from an initial widespread pattern that includes the visual cortex to a distribution restricted to the sensorimotor cortex. To determine whether specificity in corticospinal connections also emerges from an intially diffuse set of projections, we have studied the outgrowth of corticospinal axons and the formation of terminal arbors in developing hamsters. The sensitive fluorescent tracer 1, 1′, dioctadecyl-3, 3, 3′, 3′-tetramethylindocarbocyanine perchlorat (DiI) was used to label corticospinal axons from the visual cortex or from small regions of the forelimb or hindlimb sensorimotor cortex in living animals at 4–17 days postnatal. Initially axon outgrowth was imprecise. Some visual cortical axons extended transiently beyond their permanent targets in the pontine nuclei, by growing through the pyramidal decussation and in some cases extending as far caudally as the lumbar enlargement. Forelimb sensorimotor axons also extended past their targets in the cervical enlargement, in many cases growing in the corticospinal tract to lumbar levels of the cord. By about 17 days postnatal these misdirected axons or axon segments were withdrawn from the tract. Despite these errors in axon trajectories within the corticospinal tract, terminal arbors branching into targets in the spinal gray matter were topographically appropriate from the earliest stages of innervation. Thus visula cortical axons never formed connections in the spinal cord, forelimb sensorimotor axons arborized only in the cervical enlargement, and hindlimb cortical axons terminated only in the lumbar cord at all stages of development examined. Corticospinal arbors formed from collaterals that extended at right angles from the shafts of primary axons, most likely by the process of interstitial branching after the primary growth cone had extended past the target. Once collaterals extended into the spinal gray matter, highly branched terminal arbors formed within 2–4 days, beginning at about 4 and 8 days postnatal for the cervical and lumbar enlargements, respectively. These results show that specificity in connectivity is achieved by selectivty growth of axon collaterals in to appropriate spinal targets from the beginning and not by the later remodeling of intially diffuse connections. In contrast, errors occur in the initial outgrowth of axons in the corticospinal tract, which are subsequently corrected. Copyright © 1994 Wiley-Liss, Inc.     

肌电引导治疗仪的设计

介绍一种操作简单、成本较低、便于医生确定靶肌肉的肌电引导治疗仪.该仪器经过临床初步试验,效果良好.     

疾病预防控制机构推行全面质量管理初探

随着国家对疾病预防控制体系建设投入力度的不断加大 ,各级预防控制机构 (centerfordiseasecontrolandprevention ,简称CDC)的硬件设施有了很大改观。如何加强CDC质量管理 ,成为公共卫生工作的首要问题。只有建立全面质量管理体系 ,推行全面质量管理 ,才能适应这一形势发展的要求。1　全面质量管理的概念1 1　定义　　全面质量管理 (totalqualitymanagement,简称TQM)的定义为一个组织以质量为中心 ,以全员参与为基础 ,目的在于通过让客户满意和本组织所有成员及社会受益而达到长期成功的管理途径[1] 。全国卫生防疫站管理规范质量管理章…     

前哨淋巴结活检术应用于外阴癌的初步研究

目的 探讨前哨淋巴结活检术(SLNB)应用于外阴癌的可行性.方法 选择2004年10月-2008年4月间于中国医学科学院肿瘤医院接受手术治疗、术中采用SLNB的外阴癌患者21例,其中处于研究前期(即2005年5月前)的11例患者采用染料法识别前哨淋巴结(SLN)、处于研究后期的10例患者采用核素-染料联合法识别SLN,术后行常规病理检查.以病理检查结果为金标准,观察SLNB的检测效果;并观察与SLNB相关的并发症的发生情况.结果 21例患者中,20例(95%)检出SLN,其中8例为单侧腹股沟、12例为双侧腹股沟.20例SLN阳性患者共检出83枚SLN,每例患者平均检出4.2枚(1～9枚),每侧腹股沟平均2.6枚(1～6枚).其中,染料法每例患者平均检出4.4枚、每侧腹股沟平均2.5枚,核素-染料联合法每例患者平均检出3.9枚、每侧腹股沟平均2.7枚,分别比较,差异均无统计学意义(t=0.459,P=0.652;t=-0.421,P=0.717).20例SLN阳性患者腹股沟浅组淋巴结中均检出SLN,其中1例双侧腹股沟深组淋巴结中也检出SLN.20例SLN阳性的患者中,8例(10侧腹股沟)术后病理检查显示腹股沟淋巴结转移,其中7例患者(9侧腹股沟)的转移淋巴结中均包括有SLN、1例(1侧腹股沟)出现假阴性.以SLN识别预测同侧腹股沟淋巴结转移的假阴性率为10%(1/10),阴性预测值为96%(22/23).未发现与SLNB相关的损伤及不良反应.结论 SLNB应用于外阴癌安全、可行,以SLN预测同侧腹股沟淋巴结转移具有较高准确性.     

小儿手烧伤瘢痕畸形的整形外科治疗

Background: Cicatricial deformation in child burn of hand often leads to severe squaelae. According to different causes of disease , different plastic surgery were adopted .The key of operation lies in skin repairing , articulation dealing, and thumb correcting, which aim is to resume normal longitudinal and transverse arcs ,holding and clenching ability.     

人文关怀在胸心外科的实施

人文关怀是护理的核心概念和中心任务.人文关怀贯穿了住院的全过程,实施人文关怀后,病人的人格和权利得到了更多的尊重,解除了病人对疾病的恐惧、紧张,并能给病人以精神鼓励和信念支持,强化了治疗效果,病人认可了护士的专业价值.同时病人满意度提高,减少护理纠纷的发生.     

视盘血管炎——关于混合型的研讨

对６０例（６３眼）视盘血管炎的临床分型进行了探讨，结果表明，除分为Ⅰ、Ⅱ两型外，尚存在混合型，当视盘睫状血管炎性病变波及中央静脉，或两个血管系统同时受炎症侵犯时，即可再现混合型的临床表现，视盘明显水肿，视网膜静脉迂张，散在渗出，出血，动脉狭细。眼底荧光血管造影可见视盘荧光早期充盈明显迟缓，后期渗漏面积〉２．０ＰＤ，视网膜循环时间延长，混合型兼有Ⅰ，Ⅱ两型的临床特征，应作为一个独立类型存在，同时观察     

UVB radiation induces phosphorylation of the epidermal growth factor receptor, decreases EGF binding and blocks EGF induction of ornithine decarboxylase gene expression in SV40-transformed human keratinocytes

Abstract We previously demonstrated that epidermal growth factor (EGF) induces a several-fold increase in ornithine decarboxylase (ODC) activity and the steady-state level of ODC mRNA in cultured SV40-transformed human keratinocytes (1). Pretreatment of cell cultures with ultraviolet B (UVB) radiation resulted in a reduction of EGF-induced ODC activity. To determine whether UVB inhibits the accumulation of ODC mRNA by EGF, cells were pretreated with 20 mJ/cm² UVB or sham-irradiated and then incubated with 100 ng/ml EGF. Northern blot analysis revealed that UVB irradiation entirely blocked the EGF induction of ODC mRNA. Since the binding of EGF to its plasma membrane receptor is the first step in initiating a biological response, the effect of UVB on EGF binding was evaluated. UVB treatment of cultured keratinocytes resulted in an immediate and dose-dependent reduction of EGF binding. Scatchard analysis revealed thai the reduction of EGF binding was due to a 52% decrease in the number of available receptors, from 6.2 × 10⁴/cell to 3.0 × 10⁴/cell. However, UVB decreased the EGF-binding affinity very little (Kd = 0.60 nM in control and Kd=0.75 nM in UVB-treated Z114 cells). In addition, UVB did not alter the rate of EGF internalization. These data suggest that UVB blocks the signal transduction pathway of EGF that is involved in regulation of ODC gene expression. Immunoblot analysis of extracts from irradiated cells showed that UVB induced tyro-sine phosphorylation of EGFR and that the quantity of EGFR protein was unaffected by UVB treatment. Phosphorylation of EGFR may be responsible for decreased binding of EGF to its receptor.