Sequence analysis of L RNA of Lassa virus

The L RNA of three Lassa virus strains originating from Nigeria, Ghana/Ivory Coast, and Sierra Leone was sequenced and the data subjected to structure predictions and phylogenetic analyses. The L gene products had 2218-2221 residues, diverged by 18% at the amino acid level, and contained several conserved regions. Only one region of 504 residues (positions 1043-1546) could be assigned a function, namely that of an RNA polymerase. Secondary structure predictions suggest that this domain is very similar to RNA-dependent RNA polymerases of known structure encoded by plus-strand RNA viruses, permitting a model to be built. Outside the polymerase region, there is little structural data, except for regions of strong alpha-helical content and probably a coiled-coil domain at the N terminus. No evidence for reassortment or recombination during Lassa virus evolution was found. The secondary structure-assisted alignment of the RNA polymerase region permitted a reliable reconstruction of the phylogeny of all negative-strand RNA viruses, indicating that Arenaviridae are most closely related to Nairoviruses. In conclusion, the data provide a basis for structural and functional characterization of the Lassa virus L protein and reveal new insights into the phylogeny of negative-strand RNA viruses.     

基于Client／Server结构的医院图像处理系统

作者介绍了一种医院图像处理系统，可将医院的各种设备所产生的医疗图象资料，动用先进的可读写光盘为存储介质有效地进行存储，再通过通信网络及时地传送到医院的各个部门，辅助医生进行临床诊断及科研，提高有关科室及整个医院的工作效率及经济效益。     

Localization of hepatitis B surface antigen epitopes present on variants and specifically recognised by anti-hepatitis B surface antigen monoclonal antibodies

Small hepatitis B surface antigen (HBsAg) is considered to be the best marker for the diagnosis of Hepatitis B virus infection. However, HBsAg variants with mutations within the "a" determinant may be poorly or not detected by diagnostic assays. Three anti-HBsAg monoclonal antibodies (6H6B6, 27E7F10, and 2G2G10), directed against conformational epitopes, were tested for their ability to detect the wild-type HBsAg as well as variant forms and their respective epitopes were localised on the HBsAg sequence by using the phage-displayed peptide library technology. Whereas 6H6B6 did not detect mutations T123N, S143L, D144A and G145R, 27E7F10 binding was affected by mutations P120T and G145R. In contrast, 2G2G10 reacted strongly with all tested variants including variant with the G145R mutation. Part of the 6H6B6 epitope was located in the major hydrophilic region (MHR) at residues 101-105, the 27E7F10 epitope (residues 214-219) was located near the C-terminal end of the antigen and the 2G2G10 epitope at residues 199-208, within the theoretical fourth transmembrane helix. The 2G2G10 epitope localisation brings information about the HBsAg structure and the validity of established topological models. Finally, 2G2G10 is a valuable tool for HBsAg variant detection that is used as capture phase in a new bioMérieux diagnostic assay, which is currently in development.     

Small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features of the thoracic wall: A case report with histological,immunohistochemical and ultrastructural examinations

A case of small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features is presented. The tumor was encountered in a 32 year old Japanese woman with an initial presentation of palpable tumor in the left lateral region of the thorax. The resected tumor was a partially well encapsulated whitish medullary one and consisted of small round and spindle tumor cells, together with so-called rhabdoid cells in the small round cell area. Although pseudorosettes were often observed, true rosette formation could not be detected anywhere. Ultrastructurally, despite a histologic variety of tumor cells, most tumor cells possessed numerous mitochondria, some of which occasionally contained abnormal filamentous or crystalloid structures. Various amounts of microfilaments were present in most tumor cells and microtubules were present in a few. A minority of small round cells possessed a small number of neurosecretory granules, especially in short cytoplasmic processes. A positive immunoreaction for neuron specific enolase was found by immunohistochemical examination in several small round tumor cells and for neurofilaments in lesser numbers. Despite the lack of S-100 protein, MB2 was detected in both small round and spindle cells. On the basis of these findings, the tumor of the present case corresponds to malignant peripheral nerve sheath tumor with neuronal differentiation and oncocytic features.     

Fine Structure of A: Autonomic Nerve Fibers and Terminals in Human Myocardium; and B: Myocardial Changes in Congenital Heart Disease

In a histological and fine structural study of right atrial biopsy specimens from 31 patients with rheumatic heart disease (RHD), aged 7 to 46 years, and 11 patients with congenital heart disease (CHD), aged 3 to 36 years, nerve fibers or endings were seen by electron microscopy in 11 specimens. There was concurrence of ordinary axons along with terminals bearing pale cholinergic or dark adrenergic synaptic vesicles. Smaller and denser cholinergic vesicles suggested proliferation followed by exhaustion of such nerve endings. The closest proximity of nerve terminal to muscle fiber was about 100 nm. In one RHD specimen a “specific terminal cell” was present between a nerve ending and muscle fiber; in another a possible neuromuscular contact was developing at the surface of a regenerating small muscle fiber with a few myofilaments. Unmyelinated axons amidst increased subendocardial and subepicardial collagen, with prominent fibroblasts and depleted muscle fibers, were seen more frequently in specimens of CHD. Loss of myofibrils and accumulation of mitochondria, with infrequent formation of lipofuscin bodies, characterized degenerating muscle fibers in CHD also, although to a lesser degree than in RHD (reported earlier, 1985). The myocardial blood vessels in CHD tended to have pale swollen endothelial cells and narrowed lumen. The most severely affected cases of CHD were those with (1) a very wide atrial septal defect (ASD), (2) ventricular septal defect (VSD) with vegetations near the defect, (3) 1 infundibular pulmonary stenosis, and (4) Fallot's tetralogy.     

Molecular cloning and complete nucleotide sequence of the genome of Japanese encephalitis virus Beijing-1 strain

The genomic RNA of the Japanese encephalitis virus (JEV) Beijing-1 strain was reversely transcribed and the synthesized cDNA was molecularly cloned. Six continuous cDNA clones that cover the entire virus genome were established and sequenced to determine the complete nucleotide sequence of the JEV RNA. The precise genomic size was estimated as 10,965 bases long. With flanking 95 bases at the 5 and 583 bases at the 3 non-coding regions, one long open reading frame (ORF) was revealed encoding a virus polyprotein with 3,429 amino acid residues. Because of sequence homologies observed between JEV and other flaviviruses, the genome organization of JEV appears to be identical with other flaviviruses. Genetic variation detected among flavivirus genomes is consistent with the established serological relatedness between JEV and other members of flaviviruses. The secondary structure of the JEV genome is deduced and discussed concerning its involvement in genome replication.     

香港与澳门中小学学校辅导发展的比较

目的 探讨香港与澳门两地中小学学校辅导的发展，就辅导工作的内容、开展情况、辅导人员在建设上的差别以及发展速度相异的原因等方面作分析。方法 本研究以香港及澳门中小学的学校辅导员／社工为调查对象，利用自编问卷方式进行调查．结果 （1）两地的辅导员都一致认为，通过学校辅导服务可以帮助中学生建立良好的社交行为及人际关系，（2）两地的中小学都在帮助学生更好地接纳他人及尊重他人这个项目上都做得较好；（3）两地的中小学校辅导的目标不再是以处理学生的偏差行为为主，转而注重学生的个人潜能发展；（4）就课堂辅导活动开展的情况来看，香港在班级辅导、全年级辅导及全校性辅导方面都做得比较好，而澳门的全校性辅导通有待加强。至于课堂以外的辅导活动，两地均以个别晤谈，团体辅导、心理卫生讲座以及工作坊等方式开展辅导活动为多。（5）在持介制度上，香港中小学都做得比较完善；（6）咨询服务方面，香港小学做得较多，而澳门则是中学做得较多；（7）新生适应服务方面，香港较澳门做得较多；（8）香港的学校比澳门学校更多地与其它机构共同合辩小区教育；（9）香港及澳门的中学辅导员主要是学校自聘／校内编制，两地的中学社工主要是由政府资助民间志愿机构派驻。香港的小学导员以学校自聘／校内编制和政府派驻为主，香港的小学社工以政府直接派驻为多；澳门的小学辅导员为政府派驻，小学社工则由政府资助民间志愿机构派驻为多。（10）对于两地学校辅导人员学历的比较，香港中学及小学专职辅导贝、专职社工的学历均较澳门为高．结论 两地在学校辅导目标上比较一致；两地均建立了发展辅导为主，预防辅导及治疗辅导并重的辅导模式；家庭问题及人际关系问题为两地中小学生的困扰问题；两地的学校辅导活动呈现一个多元化的局面，但香港较澳门丰富；澳门需要建立完善的转介机构。     

精神分裂症患者的脑结构及其认知功能损害

精神分裂症患者的脑结构变异与认知功能损害有密切关系。以脑病理学为依据，在临床研究基础上，分别探讨了精神分裂症患者的脑结构变异、认知功能损害及两者之间的关系。最后，对广为应用的言语流畅性测验在精神分裂症评测上的作用作了分析，旨在深入理解该病的病理机制，有利于精神分裂症的临床预防与治疗。     

Relationship Between Architecture and Adhesion in Polyurethane‐Based Copolymers, 2

Summary: This study describes the chain extension, with polycaprolactone diols, of polyurethane‐graft‐poly(butyl acrylate)s which were first prepared by the step growth polymerization of a mixture of diphenylmethane‐4,4′‐diisocyanate (MDI) and α,α′‐dihydroxyl‐poly(butyl acrylate)s. The success of the chain extension reaction was studied and confirmed by ¹H NMR, SEC and DSC analysis. The incorporation of polycaprolactone sequences in the polyurethane chains modified their specific adhesive properties, bringing cohesion to the material, as demonstrated by tack measurements.

PUR‐graft‐PBA extended with PCL.