The relationship between muscle kinetic parameters and kinematic variables in a complex movement

Summary Kinematic variables of the vertical jump (jumping height, jump phase durations and joint angles) were measured on 39 male physical education students. In addition, kinetic parameters of the hip and knee extensors, and of the plantar flexors (maxima voluntary force and its rate of development) were recorded on the same subjects, in isometric conditions. The results demonstrated significant positive correlations between kinetic parameters of the active muscle groups and jumping height (r=0.217−0.464). The dominant effect on these correlations was due to the knee extensors. Correlations between these parameters and the duration of the jump phases were much weaker. Correlation coefficients between kinetic parameters and limb angles in the lowest body position showed that fast force production in one muscle group was related to a significant decrease in the joint angles of distant body segments. Multiple correlation coefficients between leg extensor parameters and kinematic variables (ranging between 0.256 for the duration of the counter-movement phase and 0.616 for jump height) suggested that kinetic parameters could explain more than a quarter of the variability of this complex human movement. Therefore, the conclusion was drawn that an extended set of measurements of the relevant musculo-skeletal system parameters could predict a considerable amount of the variability of human movement. However, high correlation coefficients between the same kinetic parameters of different muscle groups suggest that not all active muscle groups have to be included in the measurements.     

孕妇巨细胞病毒感染对胎儿影响的前瞻性研究

用酶联免疫吸附试验（ＥＬＩＳＡ）及聚合酶链反应（ＰＣＲ）方法对沈阳市４５０名孕妇进行巨细胞病毒（ＣＭＶ）筛查，并前瞻性追查到其婴儿１００名ＣＭＶ感染状况。结果孕妇９７．１１％为既往感染，０．８９％为原发感染，１１．１１％为复发感染，仅２％为易感者。４５０例中感染组孕妇有畸形儿３例，流产３例，其胎儿感染率与致畸率明显高于对照组。１００例母婴检查结果：感染组孕妇所生先天性感染儿比对照组多１．４３倍（ＲＲ＝１．４３），感染组有２名低智儿，对照组无。本组早孕原发感染对胎儿危害最大，其宫内传播率为３３．３％。感染组孕妇９例感染儿中２例巨细胞包涵体病，７例无症状。为了早期诊断达到优生目的，对孕妇进行ＣＭＶ筛查是必要的，但筛查过程中发现有活动感染时处理要慎重，最好追查到羊水阳性时考虑终止妊娠。     

Oligodontia, short stature and small head circumference with normal intelligence

Complete absence of third molars and mandibular permanent second molars is reported in a 19-year-old female, with occipito-frontal head circumference and height at the 3rd centile. The patient's intelligence, appearance and physical examination were normal. Direct count of the patient's sweat pores in different areas of the palms and digits was normal. Microcephaly, short stature and normal intelligence have been reported in two families as a distinct autosomal dominant syndrome. To the best of our knowledge, oligodontia, in addition to these findings, has not been previously reported.     

Investigation on the Maternal-Infantile Infection with Human Parvovirus B19

With the investigations on pregnant women and newbornsinfected withToxoplasma, rubella virus, cytomegalovirus,herpes simplex virus (TORCH), it was found that humanparvovirus B19 (B19 virus), which belongs to the familyParvoviridae and the genus Erythrovir…     

STAg联合ESA鼻内免疫小鼠对弓形虫垂直传播的阻断作用

观察弓形虫可溶性速殖子抗原（Soluble tachyzoite antigen,STAg）与排泄-分泌抗原（Excreted/secreted antigens,ESA）单独或联合鼻内免疫小鼠对弓形虫垂直传播的阻断作用。分别用PBS 20μL和STAg 20μg、ESA 20μg及联合抗原（STAg 10μg＋ESA 10μg）鼻内免疫BALB/c处女鼠2次,间隔2周。末次免疫后第13天处女鼠与雄鼠以2∶1同居。妊娠第8天用弓形虫速殖子（8000个/只）灌胃攻击所有孕鼠。妊娠第18天处死,计算活胎率,并测定孕鼠肝、胎盘和胎鼠脑组织弓形虫抗原和孕鼠脾组织内虫荷,同时测定孕鼠小肠冲洗液SIgA、血清IgG水平。结果表明,ESA组和联合抗原组活胎率显著高于PBS组,STAg组、ESA组和联合抗原组胎盘及胚胎感染率均低于PBS组,联合抗原组最低。孕鼠在弓形虫速殖子攻击后,PBS组明显出现竖毛、倦怠、腹部塌陷等异常表现,感染率为100%,死亡率为22.22%,而STAg组、ESA组和联合抗原组有轻微症状,感染率分别为85.71%、57.14%、57.14%,死亡率分别为16.67%、0%、0%。STAg组、ESA组和联合抗原组脾组织内虫荷均显著低于PBS组,减虫率分别为72.19%、72.29%、78.45%,ESA组和联合抗原组小肠冲洗液特异性SIgA均显著高于PBS组,联合抗原组最高,血清特异性IgG抗体水平差异不显著。由此可见,ESA单独或与STAg联合免疫可诱导孕鼠小肠液高水平SIgA,显著降低脾组织虫荷,显著提高胚胎存活率,表现出明显的垂直传播阻断的作用。     

早、中、晚孕期胎盘因子体外抗HIV-1的研究

目的 探讨早、中、晚孕期胎盘因子(PF)体外抗人免疫缺陷病毒-1(HIV-1)及在HIV-1垂直传播中的作用.方法 荧光染料Calcien-AM标记的H9/HIV-1ⅢB分别与早、中、晚孕期不同稀释浓度的PF作用后,与MT2细胞培养,荧光显微镜下观察合胞休的形成;用HIV-1ⅢB感染MT2细胞,并分别与早、中、晚孕期不同稀释浓度的PF作用后,用MTT法检测HIV-1感染细胞的存活率,用ELISA方法检测细胞培养上清中p24抗原水平.结果 各孕期PF并不能抑制MT2和H9/HIV-1ⅢB细胞的融合,但可以增加HIV-1感染细胞的存活率及减少HIV-1 p24抗原的表达,且效应以早孕期PF最大,中孕期PF其次晚孕期PF最小,并与剂量呈正相关.结论 PF在体外具有抗HIV-I的作用,并呈现孕期和剂量相关性,可能在阻断HIV-1垂直传播中具有一定作用.     

The effect of transcranial magnetic stimulation on the latencies of vertical saccades

In this study, we investigated the effect of transcranial magnetic stimulation (TMS) over the right posterior parietal cortex (PPC) on the latency of two different types of visually-guided vertical saccades: reflexive saccades triggered by the sudden onset of a target, and saccades towards target locations known in advance. For this reason, we used two oculomotor tasks: a gap and a delay task, respectively. Nine normal subjects performed vertical saccades at ±7.5 and ±15°. TMS was applied at 80 and 100 ms after target onset in the gap task, and after fixation offset in the delay task. Without TMS, we confirmed a latency asymmetry in the gap task favouring upward saccades at the lower eccentricity (7.5°), and a latency symmetry in the delay task. TMS increased the latencies of all saccades in the delay task, when delivered at 100 ms. This effect was mostly pronounced for downward saccades at 7.5°. As a result, saccade latencies showed an asymmetry in this condition, similar to the one observed in the gap task without TMS. The gap task with TMS resulted in a variable latency distribution and no significant overall effect on saccade latency. Our results indicate that the right PPC is involved in the initiation of vertical saccades in the delay task, and that this involvement appears to be enhanced for downward saccades. A conclusion for the involvement of this area in the gap task could not be drawn from this study.     

Mirror-image dental fusion and discordance in monozygotic twins

A pair of monozygotic twins had similar but not identical dental anomalies. One twin had fusion of deciduous mandibular lateral incisor and canine on the left, with normal dentition on the right; the co-twin had right mandibular incisor/canine fusion, with aplasia of the lateral incisor on the left. These findings are discussed in the context of the related phenomena of situs inversus, mirror-imaging in twins, and gradients of severity of anomalies in the four copies of the mandibular developmental dental field. © 1994 Wiley-Liss, Inc.     

Osteogenesis imperfecta lethal in infancy: Case report and scanning electron microscopic studies of the deciduous teeth

Radiologic evaluation of the skeleton and scanning electron microscopic studies of the teeth were performed on an infant boy with a lethal osteogenesis imperfecta (OI) syndrome who died at 10 mo of pneumonia. The skeletal findings included ribs that were focally expanded by fracture calluses, flat vertebral bodies, and wide limb bones. On fractured tooth surfaces, the enamel and dentin were normal as was the dentin calcification front. Although microscopic abnormalities have been noted in teeth from previously reported infants with lethal OI, a few studies also report infants with normal teeth. These differences in dental findings may indicate heterogeneity in OI lethal in infancy. Results of our study indicate that, until the primary biochemical defects in the OI syndromes are elucidated, examination of teeth from other infants with lethal OI and detailed evaluation of other clinical and skeletal features will aid in delineating heterogeneity and variation in expression in lethal OI.     

A Novel Locus for Ectodermal Dysplasia of Hairs, Nails and Teeth Type Maps to Chromosome 18q22.1–22.3

Ectodermal dysplasias (EDs) are developmental disorders affecting tissues of ectodermal origin including hair, nails, teeth and sweat glands. Ectodermal dysplasia of hair, nails and teeth is a rare type of congenital disorder characterized by sparse and thin hair, dystrophic finger-and toenails and missing and abnormal teeth. In an effort to understand the molecular basis of this form of ED a family of Pakistani origin with an autosomal recessive pattern of inheritance was ascertained from a remote region in Pakistan. The clinical features of the affected individuals included thin and fine hair on the scalp, dystrophic and flat nails, absent or sparse eyebrows and eyelashes, missing and abnormal teeth, and thin body hair. A human genome scan carried out using microsatellite markers mapped the disease locus in this family to chromosome 18q22.1–18q22.3. A maximum two-point LOD score of 2.73 (θ= 0.0) was obtained at marker D18S541. Multipoint linkage analysis resulted in a maximum LOD score of 3.42 obtained with several markers, including D18S1125, ATA82B02, D18S848, D18S488, D18S1091, and D18S485, which supported the linkage. The linkage interval is flanked by markers D18S857 and D18S815, which corresponds to a region of 17.32 cM according to Rutgers combined linkage and physical map (build 36). This region covers 8.63 Mb according to the sequence-based physical map. Three candidate genes, CDH7, CDH19 and ZNF407 , from the linkage interval were sequenced and found to be negative for functional sequence variants. This study is the first step towards the identification of a gene involved in hair, nails and teeth type ED.