Pulmonary damage by Vibrio vulnificus cytolysin.

Vibrio vulnificus is an estuarine bacterium that causes septicemia and serious wound infection. Cytolysin produced by V. vulnificus has been incriminated as one of the important virulence determinants of bacterial infection. Cytolysin (8 hemolytic units) given intravenously to mice via their tail veins caused severe hemoconcentration and lethality. Cytolysin treatment greatly increased pulmonary wet weight and vascular permeability as measured by (125)I-labeled albumin leakage without affecting those factors of other organs significantly. Blood neutrophils were markedly decreased in number after cytolysin injection, with a concomitant increase in the level of pulmonary myeloperoxidase activity, indicating that cytolysin-induced neutropenia might be due to pulmonary sequestration of neutrophils. By microscopic examination, severe perivascular edema and neutrophil infiltration were evident in lung tissues. These results suggest that increased vascular permeability and neutrophil sequestration in the lungs are important factors in lethal activity by cytolysin.     

摘除双侧眼球对大鼠视交叉上核节律性的影响

成年Ｗｉｓｔａｒ雌鼠５７只，随机分为实验组３０只，行双眼摘除术。对照组２７只。术后４周将各组动物体重相近的每３只列为一个配伍组，分别在０９：００～１０：００、１７：００～１８：００、２３：００～２４：００三个时间处死。将含有视交叉上核的脑组织经固定、恒冷箱切片后，用免疫组化ＡＢＣ法染色显示视交叉上核内含ＶＩＰ或ＡＶＰ的神经元，微机图像分析仪上测量光镜下这两种神经元的相对切面面积及平均免疫反应强度。结果：（１）对照组不同时间处死的动物ＶＩＰ能神经元切面面积以２３：００～２４：００最大，０９：００～１０：００次之，１７：００～１８：００最小，呈昼夜节律变化，ＡＶＰ能神经元也以２３：００～２４：００最大，但在０９：００～１０：００和１７：００～１８：００间差异无显著性；（２）摘除双眼后各时间组间ＶＩＰ能神经元和ＡＶＰ能神经元切面面积均不再显示显著性差异。提示实验组动物视交叉上核的这两种神经元功能活动的昼夜节律已发生改变；（３）实验组和对照组动物的ＶＩＰ能神经元和ＡＶＰ能神经元平均免疫反应强度在所测的三个时间中，均未见明显差异。     

The striopallidal pathway is involved in antiparkinsonian-like effects of the blockade of group I metabotropic glutamate receptors in rats

The aim of the study was to examine the influence of the blockade of group I metabotropic glutamate receptors (mGluRs) on the haloperidol-induced catalepsy and proenkephalin mRNA expression in the rat striatum. Bilateral, intrastriatal injection of AIDA ((RS)-1-aminoindan-1,5-dicarboxylic acid, 3-15 microg/0.5 microl), a selective antagonist of group I mGluRs, inhibited catalepsy induced by haloperidol (0.5 mg/kg i.p.). Repeated intrastriatal AIDA administrations (3 x 15 microg/0.5 microl, 3 h apart) counteracted the haloperidol-induced (3 x 1.5 mg/kg s.c., 3 h apart) increase in the proenkephalin mRNA expression in that structure. The present study indicates that the blockade of the striatal group I mGluRs may inhibit parkinsonian akinesia by normalizing the function of the striopallidal pathway.     

Adenoviral vectors expressing siRNAs for discovery and validation of gene function

RNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays. To be able to use this technology for genome-wide function screening, a more robust transduction protocol, resulting in a longer duration of the knock-down effect, is required. Here, we describe the validation of adenoviral vectors that express hairpin RNAs that are further processed to siRNAs. Infection of cell lines, or primary human cells, with these viruses leads to an efficient, sequence-specific, and prolonged reduction of the corresponding target mRNA, resulting in a reduction of the encoded protein level in the cell. For knock-down of one of the targets, GalphaS, we have measured inhibition of ligand-dependent, G-protein-coupled signaling. It is expected that this technology will prove to be of great value in target validation and target discovery efforts.     

Calculation of x-ray transmission through a multileaf collimator

A ray tracing based method has been developed to calculate the x-ray transmission through a multileaf collimator (MLC) for beam delivery verification and dose calculation in intensity modulated radiotherapy (IMRT). The path length of a ray line in the MLC is accurately calculated using the exact geometry of the MLC leaves. The fluence distribution of an IMRT field is calculated first using a point source. The fluence distribution for a realistic beam model is obtained, as an approximation, by convolving the point source fluence distribution with the distribution of source strength. Full ray tracing calculations are performed using analytic and Monte Carlo simulated beam models to verify the accuracy of the convolution method. The calculation is in better agreement with measurements using either film or a beam imaging system (BIS) than previous calculations for MLC transmission using a simplified model. This ray tracing calculation can be applied to the problem of verifying dynamic MLC leaf sequences as part of a patient-specific quality assurance process for IMRT.     

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.     

抗体包被对红细胞变形性影响的研究

作者对抗体包被的红为性进行研究，发现抗体包被改变了红细胞的变形性，在我们研究的抗体量范围内，抗体量越多，红细胞的变形性越小，作者从血液流变学的角度对上述结果作了讨论，并提出了通过测定其对红细胞变形性的影响来比较准确地标定抗体效价的可能性。