Modes of hantavirus transmission in a population of <Emphasis Type="Italic">Clethrionomys rufocanus bedfordiae</Emphasis> inferred from mitochondrial and microsatellite DNA analyses

Summary. To elucidate the mode of transmission of Puumala-related hantavirus in a population of gray red-backed voles, Clethrionomys rufocanus bedfordiae, in Hokkaido, Japan, we analyzed the kin structure and dispersal patterns of individual voles using microsatellite and mitochondrial DNA markers. Siblings or dam/offsprings was identified within the population based on the relatedness calculation with the microsatellite data. The pairwise relatedness values obtained could reveal kinship among all vole individuals within the population. Based on the assessment of kinship, we did not find a positive relationship between hantavirus transmission and close kinship. Males infected with the hantavirus carried a relatively uncommon mitochondrial haplotype. However, these infected males shared low relatedness values and were not considered closely related, i.e., they were not siblings or parent/offspring. These observations imply that hantavirus transmission in the vole population may not be related to close kinship but by random horizontal infection.     

84例周围血管病的足甲襞微循环观察

对84例周围血管病(脉管炎68例,静脉炎16例)和25例正常健康人进行了足甲襞微循环的对比观察。结果:患病组足甲襞微循环的血管形态、流态、管周状态均较正常健康组有明显差异(P<0.01)。提示:更接近病变部位的局部微循环观察更能代表病变的程度,对临床医生判断病情、选择用药和疗效观察都有很大帮助和参考价值。     

Cytotoxicity of Hemolytic, Cytotoxic Necrotizing Factor 1-Positive and -Negative Escherichia coli to Human T24 Bladder Cells

Approximately one-half of Escherichia coli isolates from patients with cystitis or pyelonephritis produce the pore-forming cytotoxin hemolysin, a molecule with the capacity to lyse erythrocytes and a range of nucleated cell types. A second toxin, cytotoxic necrotizing factor 1 (CNF1), is found in approximately 70% of hemolytic, but rarely in nonhemolytic, isolates. To evaluate the potential interplay of these two toxins, we used epidemiological and molecular biologic techniques to compare the cytotoxicity of hemolytic, CNF1⁺, and CNF1⁻ cystitis strains toward human T24 bladder epithelial cells in vitro. A total of 29 isolates from two collections of cystitis-associated E. coli were evaluated by using methylene blue staining of bladder monolayers at 1-h intervals after inoculation with each strain. Most (20 of 29) isolates damaged or destroyed the T24 monolayer (less than 50% remaining) within 4 h after inoculation. As a group, CNF1⁺ isolates from one collection (11 strains) were less cytotoxic at 4 h than the CNF1⁻ strains in that collection (P = 0.009), but this pattern was not observed among isolates from the second collection (18 strains). To directly evaluate the role of CNF1 in cytotoxicity of hemolytic E. coli without the variables present in multiple clinical isolates, we constructed mutants defective in production of CNF1. Compared to the CNF1⁺ parental isolates, no change in cytotoxicity was detected in these cnf1 mutants. Our results indicate that CNF1 does not have a detectable effect on the ability of hemolytic E. coli to damage human bladder cell monolayers in vitro.     

针刺对实验性脑缺血作用机理的研究进展

缺血性脑血管疾病是一个非常复杂的病理生理过程 ,是多种机制共同作用的结果。本文从针刺对实验性脑缺血在脑组织形态学改变、血液流变学、脑微循环等方面的研究进展作一综述。     

咀嚼肌的应用解剖学研究——I.咬肌的动脉与神经

在30具(男23.女7)共60例成人尸体上观察与测量了咬肌的动脉与神经来源、咬肌神经的分支以及肌内构筑、咬肌由上颌动脉咬肌支和邻近动脉肌支供血,面动脉与面横动脉的咬肌支为其主要营养动脉.咬肌神经在肌内可分成单干和双干两型,前者居多,两型中其肌内分支间均有吻合.就结果对有关颌面外科应用问题进行了探讨.     

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF): identification of a binding site for a neutralizing antibody.

One approach to the localization of functionally active regions of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is to map the epitopes recognized by neutralizing anti-hGM-CSF monoclonal antibodies. We have defined the epitope recognized by one neutralizing antibody (LMM102) using proteolytic fragments obtained by enzymic digestion of bacterially synthesized hGM-CSF. RP-HPLC fractionation of a tryptic digest resulted in the identification of an immunoreactive "tryptic core" peptide containing 66 amino acids (52% of the protein). Further digestion of this "tryptic core" with S. aureus V8 protease produced a unique immunoreactive hGM-CSF product comprising two peptides, residues 86-93 and 112-127, linked by a disulfide bond between residues 88 and 121. The individual peptides, generated by reduction with dithiothreitol, were not recognized by the antibody. An analog of this peptide has been synthesized chemically and shown to have similar immunoreactivity to the epitope obtained by enzymic digestion. A series of modified peptides has also been synthesized to identify further the region required for antibody recognition.     

Novel micro-crosslinked poly(organophosphazenes) with improved mechanical properties and controllable degradation rate as potential biodegradable matrix

As biodegradable materials, linear polyphosphazenes undergo rapid hydrolysis degradation but exhibit poor mechanical properties. Blending with biodegradable polyesters or inorganic particles strengthen their mechanical properties but give rise to slower degradation rate. To balance the mechanical properties and the degradation rate, micro-crosslinked polyphosphazenes were synthesized in this study. Their glass transition temperatures, mechanical properties, and in vitro degradation behavior were investigated. 2-hydroxyethyl methacrylate (HEMA) was firstly attached to the side chain along with glycine ethyl ester to prepare co-substituted poly(organophosphazene) with pendant ethenyl substituents. The co-substituted poly(organophosphazene) was blended with HEMA or acrylic acid (AA) followed by a free radical polymerization to prepare micro-crosslinked poly(organophosphazenes). The resulting crosslinked polymers showed two separate glass transition temperatures depending on the HEMA or AA feed. Incorporation of crosslinking affected the mechanical properties positively. Crosslinked poly(organophosphazenes) showed an approximately 11-17 fold increase in terms of modulus of elasticity when compared to the linear counterpart. In vitro degradation tests indicated that HEMA-crosslinked polymers hydrolyzed at a retarded rate while AA-crosslinked polymers hydrolyzed at a moderate rate compared to linear polymers.     

Structural characterization of the C4a anaphylatoxin from rat

The C4a anaphylatoxin was purified from rat sera activated by heat-aggregated IgG. The anaphylatoxin was isolated by a three-step purification procedure and was judged to be homogeneous based on visualization of a single stained band after electrophoresis on both cellulose acetate membrane strips and on 9% SDS-polyacrylamide gels. Results from Ouchterlony and radioimmunoassay analysis indicated that neither rat C5A nor C3a contaminated the C4a preparation. Rat C4a is a glycoprotein estimated to be 11,000-12,000 mol. wt and contains 76 amino acid residues representing a mol. wt of 8577 and one oligosaccharide unit of 2000-3000 mol. wt. Rat C4a is weakly active in contracting guinea pig ileum at 0.1-1 microM, which is comparable with the activity of human C4a. Both human and bovine C4a are polypeptides free of carbohydrate while rat and presumably mouse C4a are glycoproteins. The complete primary structure of rat C4a anaphylatoxin has been elucidated as follows: (formula; see text)