Role of the YadA protein in prevention of opsonization of Yersinia enterocolitica by C3b molecules.

When mixed with normal human serum, wild-type pathogenic Yersinia enterocolitica, previously incubated at 37 degrees C, fixed less C3b than its variant cured of the virulence plasmid pYV. Mutants unable to secrete the Yop proteins were still protected against C3b deposition. By contrast, mutants deficient in the production of outer membrane protein YadA fixed more C3b than their YadA+ parent. Gene yadA, cloned as a minimal polymerase chain reaction fragment and introduced in trans, complemented the mutations. Production of YadA by recombinant Escherichia coli LK111 also resulted in a reduction of the amount of C3b deposited on the bacterial surface. The reduction of C3b at the surface of Y. enterocolitica YadA+ compared with YadA- cells correlated with an increase of the amount of factor H fixed at the bacterial surface. The YadA monomer separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to a nitrocellulose membrane was able to bind factor H. We conclude that factor H bound to YadA reduces the C3b deposition on the bacterial surface, probably by a rapid inactivation of C3b.     

Antigenic mapping of the envelope proteins of equine infectious anemia virus: identification of a neutralization domain and a conserved region on glycoprotein 90

Summary Monoclonal antibodies (MCAbs) were used to dissect the antigenic sites of the surface glycoproteins of the prototype cell-adapted Wyoming strain of equine infectious anemia virus (EIAV) Serologic reactivities of these MCAbs were determined by ELISA, additive ELISA, competitive ELISA, and Western blot assays. The results indicated that antigenic reactivity of gp90 was localized on at least four distinct epitopes, two of which were important in neutralization. Our studies also revealed that these epitopes were localized on overlapping antigenic sites on gp90. On the other hand, only two distinct non-overlapping epitopes were identified on gp45. Competitive binding studies of neutralizing MCAbs and reference EIA-positive horse serum delineated the presence of a neutralization domain on gp90 that appears to be immunodominant both in naturally infected horses and in mice immunized with EIAV. Limited proteolytic fragmentation of the gp90 component of several serologically distinct EIAV isolates produced common 12K immunoreactive fragments that contained a conserved epitope. These results indicate the occurrence of conserved antigenic regions on EIAV glycoproteins as well as a neutralization domain on gp90, which can be used as potential targets for vaccine development.     

反义CD40RNA对EB病毒转化的B细胞CD40分子表达和增殖能力的影响

目的 :探讨瞬时表达的反义CD4 0RNA ,对EB病毒转化的健康人B细胞膜表面CD4 0分子表达和增殖能力的影响。方法 :应用T A克隆技术和亚克隆技术 ,构建人反义CD4 0RNA的真核表达载体pcDNA3/CD4 0 ,并以其转染本室建立的EB病毒转化的健康人B细胞。应用流式细胞仪 (FACS) ,检测B细胞膜上CD4 0分子表达的变化。应用MTT比色法检测反义CD4 0RNA对B细胞增殖能力的影响。结果 :与转染空载体pcDNA3组相比 ,转染pcDNA3/CD4 0细胞上CD4 0分子的表达降低 (P<0 .0 1) ,其增殖能力明显降低 (P <0 .0 1)。结论 :反义CD4 0RNA技术 ,可作为有效的免疫调控手段。CD4 0基因本身在细胞的生长代谢中也起着重要作用     

Historical comment on DSM-III schizoid and avoidant personality disorders

The authors examine the DSM-III distinction between schizoid and avoidant personality disorders. This distinction is based on Millon's biosocial learning theory and his interpretation of Kretschmer's personality types. The authors argue that this separation of a continuous distribution is historically misconceived and serves to obscure the significant features of schizoid personality. They examine Kretschmer's conceptualization of schizoid personality for the implications it carries for the development of a classification of personality disorder, suggesting that Kretschmer's approach implies a "polythetic" model of personality disorder that conceptualizes disorders as categories of dimensions.     

Effects of spelling-to-sound regularity on word identification following brief presentation in the right or left visual field

In this experiment subjects were briefly presented with a vertically written word to either the left or right visual field. On half the critical trials the target word was irregular in its spelling-to-sound correspondence (e.g. PINT) and in the other half it was regular (e.g. LIME). With right visual field presentation substantially more regular than irregular words were reported correctly but with left visual field presentation no such effect was found. The data also showed the presence of far more "regularization" errors following right visual field presentation. The data are seen as consistent with the view that the right hemisphere is not capable of generating phonology.     

新洁尔灭对小白鼠抗早孕的病理组织学观察

本文报告用不同剂量的新洁尔灭和同体积生理盐水注入怀孕5天小白鼠的宫腔内,3天后杀死,观察其蜕膜、胚泡、宫内膜腺体和卵巢黄体病理学改变。实验表明:对照组无改变。实验组小白鼠的蜕膜细胞全部退变坏死。病变随着给药量的递增而渐趋严重;同时胚泡亦有退变和坏死。提示:新洁尔灭对早期妊娠小白鼠是有抗早孕效果的。根据实验结果,我们认为新洁尔灭对小白鼠抗早孕的机制,很可能是一个综合因素,有直接的,也有间接的。作者强调在抗早孕机制诸因素中,蜕膜退变坏死是一个重要的因素。     

主动脉性咽下困难的X线诊断——附10例病例分析

本文报道10例主动脉性咽下困难。病因为高血压和/或主动脉硬化。X线特征为:①下段食管不完全梗阻;②梗阻端正位呈两种不同形态:一为梳齿状;一为偏心性狭窄。左、右前斜位均为尖端指向前的偏心性狭窄;③受压移位食管左前斜位呈正“C”字形,右前斜位是反“C”字形,“C”字内有降主动脉断面致密影;④移位食管内之粘膜扭曲交叉。     

Prostaglandin F2 alpha stimulates phosphatidylinositol 4,5-bisphosphate hydrolysis and mobilizes intracellular Ca2+ in bovine luteal cells.

The present studies were conducted to determine whether prostaglandin F2 alpha (PGF2 alpha) stimulates the production of "second messengers" derived from inositol phospholipid hydrolysis and increases intracellular free Ca2+ ([Ca2+]i) in isolated bovine luteal cells. PGF2 alpha provoked rapid (10 sec) and sustained (up to 60 min) increases in the levels of inositol mono-, bis-, and trisphosphates (InsP, InsP2, and InsP3, respectively). InsP3 was formed more rapidly than InsP2 or InsP after PGF2 alpha treatment. In addition, PGF2 alpha increased inositol phospholipid turnover, as evidenced by increased 32PO4 incorporation into phosphatidic acid and phosphatidylinositol. LiCl (1-20 mM) enhanced inositol phosphate accumulation in response to PGF2 alpha. Maximal increases in InsP3 occurred at 1 microM PGF2 alpha, with half-maximal stimulation occurring at 36 nM. The acute effects of PGF2 alpha on InsP3 levels were independent of reductions in extracellular calcium. Prostaglandins E1 and E2 also stimulated increases in inositol phosphate levels, albeit to a lesser extent. PGF2 alpha also induced rapid and concentration-dependent increases in [Ca2+]i as measured by quin-2 fluorescence. The PGF2 alpha-induced increases in [Ca2+]i were maximal within 30 sec (approximately 2- to 3-fold), and [Ca2+]i remained elevated for 8-10 min. The PGF2 alpha-induced increases in [Ca2+]i were also independent of extracellular calcium. These findings demonstrate that the action of PGF2 alpha is coupled to the phospholipase C-InsP3 and diacylglycerol second messenger system in the corpus luteum.     

Survival and prognostic indicators in compensated and decompensated cirrhosis

Six-year survival of cirrhosis was assessed in a series of 1155 consecutive patients (751 men, 404 women). Among the men, 33% were alcoholics and 18% were HB_sAg positive; corresponding figures for the women were 15% and 6%, respectively. Features of decompensation at first presentation were observed in 63% of the patients. Six-year survival was 54% in compensated and 21% in decompensated patients. No significant differences in survival were found between alcoholics and nonalcoholics. Leading causes of death were liver failure (49%), hepatocellular carcinoma (22%), and bleeding (13%). The prognostic role of 21 variables was evaluated separately in compensated and decompensated patients by the Cox's regression model. The following variables were found to be significant predictors of death risk in compensated patients: male sex, HB_sAg positivity, age, prothrombin time prolongation, and esophageal varices. In decompensated disease the significant indicators of death risk were: hepatocellular carcinoma, encephalopathy, hemorrhage, SGOT, esophageal varices, gamma globulins, prothrombin time prolongation, continued abuse of alcohol, HB_sAg positivity, gamma glutamyl transpeptidase, and cholinesterase. A simple prognostic index based upon the relative risk coefficient of the significant variables is suggested.Members of the Liver Study Group are: Maria Caltagirone, Gabriella Filippazzo, Giovanni Gatto, Gandolfo Giannuoli, Silvio Margin, Guiseppe Malizia, Lorenzo Maniaci, Maria Pia Marcenó, Alberto Maringhini, Rocco Micciolo, Salvatore Orsini, Fabio Pace, Ugo Palazzo, Linda Pasta, Giuseppina Russo, Rosa Giovanna Simonetti, Mario Spinello, Mario Traina, Mario Valenza, Maria Vinci, Giovanni Vizzini.     

Which smokers report most relief from craving when using nicotine chewing gum?

Seventy-seven smoker clinic clients who managed at least 2 weeks of smoking abstinence while chewing 2 mg nicotine gum reported the degree to which the gum reduced their craving for cigarettes, their daily gum consumption and the extent of urges to smoke despite the gum. Greatest relief from craving by the gum was reported by smokers with higher pre-abstinence expired-air carbon monoxide (CO) concentrations and higher stimulant and dependent scores on a smoking motivation questionaire but not greater usual daily cigarette consumption. Gum consumption correlated positively with expired-air CO, usual daily cigarette consumption, and stimulant and dependent smoking scores. Despite the gum, urges to smoke and difficulty not smoking were reported and the severity of these was associated with indulgent, stimulant and dependent smoking scores but not CO or usual daily cigarette consumption. The results are discussed in terms of the possible role of pharmacological and non-pharmacological factors in craving.