Expression of TGF-beta in attenuated Salmonella typhimurium: oral administration leads to the reduction of inflammation, IL-2 and IFN-gamma, but enhancement of IL-10, in carrageenin-induced oedema in mice.

Chlamydiae are a major cause of infertility and preventable blindness and there is currently no effective vaccine in humans or rodents against these organisms. We have previously shown that a peptide of 12 amino acids (termed TINKP) from a conserved region of the major outer membrane protein (MOMP) of Chlamydia trachomatis (C. trachomatis) is a primary T-cell epitope in humans. Here we showed that when dendritic cells (DC) from C3H or BALB/c mice were pulsed in vitro with the peptide they stimulated proliferation of syngeneic T cells in vitro indicating that the peptide is also a primary T-cell epitope in mice. Since the skin is a rich source of DC, we immunized mice from each strain with an intradermal injection of the peptide. Humoral and cell-mediated immunity to peptide, MOMP or whole elementary bodies (EB) of C. trachomatis (F/NI1/GU) were assessed. No antibody response to TINKP was observed. However, immunized mice showed recall responses to all three chlamydial antigens. T-cell-mediated immunity in the absence of antibody was induced by a single injection of the peptide intradermally. C. trachomatis isolated from the human genital tract causes salpingitis in mice. Preliminary studies in susceptible C3H mice indicated that intradermal injection of peptide conferred some protection against the development of salpingitis. Thus, a primary T-cell epitope identified by in vitro stimulation using DC can also initiate cell-mediated immunity in vivo and this approach may be useful in the development of vaccines.     

用标记分析法检测我国海南省登革2型病毒抗原性变化

我们试用标记分析法,用3种单克隆抗体(黄病毒科特异性、登革病毒属特异性和登革病毒2型型特异性单克隆抗体)研究了我国海南省1985～1987年3年内流行的登革2型病毒8个流行株的抗原性变化,并与标准株新几内亚B株进行了比较。发现6株与标准株类似,2株显示出明显的差异。标记分析法为病毒抗原分析提供了一个简便、快速的方法,可用来监测一个地区病毒株群的变化及新株的传入。     

Electrospun P(LLA-CL) nanofiber: a biomimetic extracellular matrix for smooth muscle cell and endothelial cell proliferation

Poly(L-lactide-co-epsilon-caprolactone) [P(LLA-CL)] with L-lactide to epsilon-caprolactone ratio of 75 to 25 has been electrospun into nanofibers. The relationship between electrospinning parameters and fiber diameter has been investigated. The fiber diameter decreased with decreasing polymer concentration and with increasing electrospinning voltage. The X-ray diffractometer and differential scanning colorimeter results suggested that the electrospun nanofibers developed highly oriented structure in CL-unit sequences during the electrospinning process. The biocompatibility of the nanofiber scaffold has been investigated by culturing cells on the nanofiber scaffold. Both smooth muscle cell and endothelial cell adhered and proliferated well on the P(LLA-CL) nanofiber scaffolds.     

Legionella pneumophila NudA Is a Nudix hydrolase and virulence factor

We studied the identity and function of the 528-bp gene immediately upstream of Legionella pneumophila F2310 ptsP (enzyme I(Ntr)). This gene, nudA, encoded for a Nudix hydrolase based on the inferred protein sequence. NudA had hydrolytic activity typical of other Nudix hydrolases, such as Escherichia coli YgdP, in that Ap(n)A's, in particular diadenosine pentaphosphate (Ap(5)A), were the preferred substrates. NudA hydrolyzed Ap(5)A to ATP plus ADP. Both ptsP and nudA were cotranscribed. Bacterial two-hybrid analysis showed no PtsP-NudA interactions. Gene nudA was present in 19 of 20 different L. pneumophila strains tested and in 5 of 10 different Legionella spp. other than L. pneumophila. An in-frame nudA mutation was made in L. pneumophila F2310 to determine the phenotype. The nudA mutant was an auxotroph that grew slowly in liquid and on solid media and had a smaller colony size than its parent. In addition, the mutant was more salt resistant than its parent and grew very poorly at 25 degrees C; all of these characteristics, as well as auxotrophy and slow-growth rate, were reversed by transcomplementation with nudA. The nudA mutant was outcompeted by about fourfold by the parent in competition studies in macrophages; transcomplementation almost completely restored this defect. Competition studies in guinea pigs with L. pneumophila pneumonia showed that the nudA mutant was outcompeted by its parent in both lung and spleen. NudA is of major importance for resisting stress in L. pneumophila and is a virulence factor.     

绵羊肥大细胞中类胰蛋白酶的证实

用甲苯胺蓝和阿尔辛蓝常规组织化学方法及特异性酶底物鉴定人肥大细胞类胰蛋白酶的酶组织化学技术，采用小鼠抗人肥大细胞类胰蛋白酶单克隆抗体，（ＡＡ１、ＡＡ３和ＡＡ５）通过间接免疫过的经物酶技术对绵羊肥大细胞的组织化学特性进行研究，酶组织化学技术及免疫组织化学技术均首次证实了绵羊肥大细胞颗粒中含有类胰蛋白酶，且该酶可作为绵羊肥大细胞的特异性标志，对于绵羊肥大细胞的常规组织化学染色，Ｃａｒｎｏｙ液及中性缓门     

Pertussis toxin-catalyzed ADP-ribosylation of Gi-2 and Gi-3 in CHO cells is modulated by inhibitors of intracellular trafficking.

In previous studies, an in vitro ADP-ribosylation assay was developed to quantitatively evaluate the in vivo ADP-ribosylation of eukaryotic target proteins in intact Chinese hamster ovary (CHO) cells by pertussis toxin (PT). Immunoblot analysis identified the two PT-sensitive target proteins in CHO cells as Gi-2 and Gi-3. In this in vitro ADP-ribosylation assay, the ability of PT and ADP-ribosylate Gi-2 and Gi-3 intact CHO cells was not inhibited by cytochalasin D but was inhibited by chloroquine, monensin, and nocodazole. These data implicated the involvement of a cytochalasin D-independent endocytic mechanism, a pH-sensitive step, and microtubules in the ADP-ribosylation of Gi-2 and Gi-3 by PT in intact CHO cells. Preincubation of CHO cells with cycloheximide, at concentrations that reduced protein synthesis by > 95%, did not inhibit the ability of PT to ADP-ribosylate Gi-2 and Gi-3. Control experiments showed that these agents did not affect either the ability of PT to directly ADP-ribosylate the heterotrimeric G protein, Gt, or the binding of PT to CHO cells, except that monensin slightly inhibited the binding of PT to CHO cells. These results are consistent with a model in which PT is internalized by receptor-mediated endocytosis, probably via a cytochalasin D-independent pathway, which involves intracellular trafficking through late endosomes and the Golgi apparatus. An alternative model predicts the presence of a eukaryotic factor that traffics within cells via this pathway and is required by PT to ADP-ribosylate Gi proteins.     

External quality assurance as a revalidation method for pathologists in pediatric histopathology: Comparison of four international programs

Aim  

External quality assurance (EQA) is an extremely valuable resource for clinical pathologists to maintain high standards, improve diagnostic skills, and possibly revalidate medical license. The aim of this study was to participate in and compare four international slide survey programs (UK, IAP-Germany, USA-Canada, Australasia) in pediatric histopathology for clinical pathologists with the aim to use it as a revalidation method.     

Recruiting and retaining GPs and patients in intervention studies: the DEPS-GP project as a case study

Background  

Recruiting and retaining GPs for research can prove difficult, and may result in sub-optimal patient participation where GPs are required to recruit patients. Low participation rates may affect the validity of research.     

No association between schizophrenia and homozygosity at the D3 dopamine receptor gene

The D₃ dopamine receptor gene is an important candidate gene for schizophrenia, since (because of its almost exclusive expression in the limbic system) it combines the dopamine receptor hypothesis with the limbic system hypothesis of schizophrenia. A BalI restriction fragment length polymorphism of the D₃ dopamine receptor gene has been typed in 107 schizophrenic patients and 98 normal controls from Sichuan (China). With regard to alleles or genotypes, no significant differences were obtained between controls from Europe and China, between patients and controls, and between patient subgroups and controls. These results indicate a lack of association between schizophrenia and the D₃ dopamine receptor gene in our sample. Our findings are at variance with reports of a significant excess of homozygosity at the D₃ dopamine receptor gene in schizophrenic patients from Wales (United Kingdom) and Alsace (France). In conclusion, further studies will be needed with larger samples of patients from Wales and Alsace as well as with samples of different racial groups to prove or disprove the initial positive association between schizophrenia and genotypes of the D₃ dopamine receptor gene. © 1993 Wiley-Liss, Inc.     

关于中医推拿手法摆动类法施力的频域分析

依据中医推拿手法测力分析仪ＦＺ－Ⅰ型上所测得的施力数据，对各向作用力进行频域分析，并对各频段成分在综合推拿效用中所起的作用以及与其它因素的相互关系作了比较与分析。