SARS患者TGFβ1和PDGF-BB的动态监测及其临床意义

目的动态监测严重急性呼吸综合征(SARS)患者血清转化生长因子β1(TGFβ1)和血小板衍生生长因子BB(PDGF-BB)水平的变化,以探讨细胞因子在SARS疾病中的作用。方法采用酶联免疫吸附试验 ,测定SARS患者早期、恢复期和随访时TGFβ1和PDGF -BB含量 ,并与急诊等一线未患SARS组及健康对照组比较 ,作描述性分析及方差分析。结果SARS患者早期组血清TGFβ1均值高于恢复期组和随访组 (P<0.05),SARS恢复期组、随访组TGFβ1均值均显著低于急诊等一线未患SARS组和健康对照组(P<0.01),其它组间两两比较均无显著性差异(P>0.05)。五组人群PDGF -BB均值水平总体比较无显著性差异(P>0.05)。结论TGFβ1可能与SARS患者机体调节免疫应答和免疫损伤有关 ,PDGF -BB与SARS的免疫损伤无关。     

Characterization of a gene encoding survival motor neuron (SMN)-related protein, a constituent of the spliceosome complex

Mutations in the gene encoding the Survival Motor Neuron (SMN) protein are responsible for autosomal recessive proximal spinal muscular atrophy (SMA). SMN orthologues have been identified in the nematode worm Caenorhabditis elegans and the yeast Schizosaccharomyces pombe but, to date, no human paralogues have been described. Here we describe identification and characterization of an SMN-related protein (SMNrp) gene that encodes a novel protein of 239 amino acids, which has recently been identified as a constituent of the spliceosome complex and designated SPF30. Significant similarity to the SMN protein is apparent only within a central region of SMNrp that represents a tudor domain. The SMNrp/SPF30 gene has been mapped to chromosome 10q23. It is differentially expressed, with abundant levels in skeletal muscle. An exclusively nuclear localization for SMNrp in cultured cells and muscle sections was revealed using GFP fusion constructs and thereafter confirmed with a polyclonal antibody raised against SMNrp. Overexpression of SMNrp as a fusion protein in HeLa cells in culture induced dose-dependent apoptosis with positive TUNEL staining. In addition to a possible role for this protein as a pro-apoptotic factor, SMN and its related protein share significant similarities in sequence and cellular function.      

Comparison of the structure of human intervertebral discs in the cervical,thoracic and lumbar regions of the spine

Posterior and anterior heights, cross-sectional area and shape were measured for all the intervertebral discs in four spines from elderly human cadavers. Disc height was a minimum at the T4-5 level; thoracic discs were less wedge-shaped than those in the cervical and lumbar regions. Cross-sectional area increased from the cranial to caudal extremity; at the L5-S1 level the nucleus pulposus occupied a high proportion of this area. Cervical discs tended to have an elliptical cross-sectional shape, thoracic discs were more circular and lumbar discs tended to have an elliptical cross-section which was flattened or re-entrant posteriorly. This shape distribution was quantified by defining a shape index which had a maximum value of 1 for a circular cross-section. Orientations of the reinforcing fibres in the outer lamellae of the anterior annulus fibrosus were measured from 27 discs by X-ray diffraction. For these measurements, C3-4, T7-8 and L2-3 were chosen as representative of cervical, thoracic and lumbar discs. The fibre tilt, with respect to the axis of the spine, was significantly less in the cervical discs (at 65 degrees) than in the thoracic and lumbar discs (about 70 degrees). These findings are interpreted in relation to differing functional requirements and possible mechanisms of failure in the cervical, thoracic and lumbar regions of the spine in the light of current knowledge on the biomechanics of the intervertebral disc.     

Immunoglobulin G1 enzyme-linked immunosorbent assay for diagnosis of Johne's Disease in red deer (Cervus elaphus)

This study was designed to develop a customized enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Johne's disease (JD) in farmed deer. Two antigens were selected on the basis of their superior diagnostic readouts: denatured purified protein derivative (PPDj) and undenatured protoplasmic antigen (PpAg). ELISA development was based on the antigen reactivity of the immunoglobulin G1 (IgG1) isotype, which is a highly specific marker for mycobacterial disease seroreactivity in deer. Sensitivity estimates and test parameters were established using 102 Mycobacterium paratuberculosis-infected animals from more than 10 deer herds, and specificity estimates were determined using 508 uninfected animals from 5 known disease-free herds. A receiver-operated characteristic analysis determined that at a cut point of 50 ELISA units, there was a specificity of 99.5% and sensitivities of 84.0% with PPDj antigen, 88.0% with PpAg, and 91.0% when the antigens were used serially in a composite test. Estimated sensitivity was further improved using recombinant protein antigens unique for M. paratuberculosis, which identified infected animals that were unreactive to PPDj or PpAg. While 80% of animals that were seropositive in the IgG1 ELISA had detectable histopathology, the assay could also detect animals with subclinical disease. The test was significantly less sensitive (75%) for animals that were culture positive for M. paratuberculosis but with no detectable pathology than for those with pathological evidence of JD (>90%). When the IgG1 ELISA was used annually over a 4-year period in a deer herd with high levels of clinical JD, it eliminated clinical disease, increased production levels, and reduced JD-related mortality.     

内洋地黄素拮抗剂上调缺血再灌注损伤大鼠心肌细胞膜钠泵亚基的表达

目的： 观察内洋地黄素特异性拮抗剂地高辛抗血清对心肌缺血再灌注（MIR）损伤大鼠心肌组织内洋地黄素水平、钠泵活性、线粒体总钙浓度以及钠泵各亚基基因表达的影响，探讨内洋地黄素在心肌缺血再灌注损伤中的作用及其机制。方法: 将56只雄性SD大鼠随机分成7组，每组8只。假手术对照组（sham）：丝线穿过左冠状动脉前降支，但不结扎；缺血再灌注组（MIR）：结扎左冠状动脉前降支30 min，再灌注45 min；生理盐水组（NS）、维拉帕米组（Ver）、小剂量、中剂量、大剂量地高辛抗血清组（ADA）：于再灌注前5 min经股静脉分别注射生理盐水、维拉帕米5 mg·kg^-1、地高辛抗血清8.6 mg·kg^-1、 17.3 mg·kg^-1、34.5 mg·kg^-1，容积均为5 mL·kg^-1，5 min内注射完毕，其余同MIR模型组。再灌注结束后，立即取缺血区左室心肌检测心肌匀浆内洋地黄素水平、心肌细胞膜Na+ K+_ATP酶和Ca2+_Mg2+_ATP酶活性、线粒体总钙浓度；分别采用RT-PCR及Western blotting方法和免疫组化方法检测心肌钠泵α₁、α₂、α₃和β₁亚基mRNA及蛋白水平基因表达的改变。结果: 心肌缺血再灌注损伤时，心肌组织内洋地黄素水平明显升高，心肌细胞膜钠泵和Ca2+_Mg2+_ATP酶活性显著下降，线粒体总钙浓度升高，钠泵α₁、α₂、α₃和β₁亚基在mRNA及蛋白水平基因表达均明显下降；维拉帕米除具有降低线粒体总钙浓度外，对其它各项指标无明显影响。地高辛抗血清呈剂量依赖性地显著降低心肌组织内洋地黄素水平，恢复细胞膜钠泵和Ca2+_Mg2+_ATP酶活性，降低线粒体总钙浓度，上调钠泵α₁、α₂、α₃和β₁亚基mRNA及蛋白水平的基因表达。结论: 心肌缺血再灌注促进机体内洋地黄素分泌增加，后者通过下调心肌细胞膜上的钠泵α₁、α₂、α₃和β₁亚基基因表达抑制钠泵活性，进而抑制Ca2+_Mg2+_ATP酶活性，导致线粒体内钙超载，介导心肌缺血再灌注损伤。内洋地黄素特异性拮抗剂地高辛抗血清通过阻断内洋地黄素的生物学作用，上调钠泵各亚基的基因表达，发挥其抗心肌缺血再灌注损伤的作用。     

Reduction of adhesion formation in rabbits by intraperitoneal administration of lazaroid formulations

Adhesion formation is a major source of postoperative morbidity and mortality. In this study, the ability of a variety of lazaroid formulations [the antioxidant 21-aminosteroid PNU74006F (tirilazad) and the non-steroidal 2-methylaminochroman derivative PNU83,836E] to reduce i.p. adhesion formation in three rabbit models was examined. In initial studies, PNU83836E was administered via Alzet miniosmotic pump to the site of injury. In the sidewall and double uterine horn models, PNU83,836E was administered via Alzet miniosmotic pump for the entire postoperative interval. In the sidewall model, there was a dose- dependent reduction in the area of the sidewall injury that was involved in adhesions. In the double uterine horn model, PNU83,836E was administered via Alzet miniosmotic pump to the area of injury for 1, 2, 3 or 7 days. Administration for as little as 24 h after surgery significantly reduced the extent of adhesion formation and the reduction was increased if it was administered for longer. Further studies were conducted in which various lazaroid formulations were administered as a bolus at the end of surgery. In both the sidewall and double uterine horn models, administration of either PNU83,386E (in citrate buffer) or PNU74006F (in cyclodextrin or lipid emulsion vehicles) at the end of surgery reduced adhesion formation. Administration of a bolus of PNU74006F 10 min prior to initiation of surgery with or without additional treatment at the end of surgery further increased its efficacy in the reduction of adhesion formation. Administration of a minimum of 1.5 mg before and after surgery (3 mg total) was required for maximal efficacy. These studies demonstrate that pre- and postoperative administration of either a steroidal (PNU74006F) or non-steroidal (PNU83,836E) lazaroid intraperitoneally reduced the formation and reformation of postoperative adhesions in three animal models.      

Agonistic behaviour in rats: evidence for non-involvement of opioid mechanisms

It has recently been proposed that a stress-activated, endogenous analgesia mechanism would be adaptive in situations in which pain perception might otherwise disrupt effective behavioural performance. In a semi-natural test situation, the current study examined two predictions arising from this hypothesis: (1) in a manner analogous to other stressors, agonistic experience should produce analgesia and, if naloxone-sensitive opioid mechanisms are implicated, then (2) pretreatment with naloxone should block the development of this response and alter the displayed behaviour patterns. Neither prediction was substantiated by the data. Experience of an agonistic encounter failed to produce analgesia in either resident or intruder animals. Furthermore, naloxone hydrochloride (1-25 mg/kg) was also without effect on patterns of offense or defense. Data are discussed in relation to the critical nature of the stimulus factors involved in the activation of endogenous analgesic mechanisms and the postulated involvement of such mechanisms in biologically-adaptive behaviours.     

Detection of virus particles by electron microscopy with polyacrylamide hydrogel.

The use of lyphogel to concentrate the number of virus particles in specimens for electron microscopic examination was studied in parallel with ultracentrifugation. One hundred faecal and urine samples were compared. Both methods had a similar sensitivity. Lyphogel was economical, simple, and rapid in use; in contrast to ultracentrifugation, it required relatively little material. The procedure could be done within a safety cabinet, and virus particles were morphologically undamaged by the process.     

冠心病家族史青少年载脂蛋白E、B的基因多态性

目的 探讨青少年载脂蛋白E(apolipoprotein E，apoE)、apoB基因多态性对冠心病的遗传易感性。方法 应用聚合酶链反应—限制性片段长度多态性技术，对244名健康汉族大学生(冠心病家族史阳性者109人，阴性者135人)的apoE、apoB XbaI、apoB 3’可变数目串联重复序列(variable number of tandem repeat ，VNTR)基因型进行分析。结果 阳性组的e4、x^ 、VNTR—B(hypervariable element，HVE＞38)等位基因频率显著高于阴性组(P＜0．05)，且与血总胆固醇、低密度脂蛋白—胆固醇、aPoBl00水平升高有显著相关(P＜0．05)。结论 apoE的e4、apoB Xba I的x^ 、apoB3’VNTR的VNTR—B可能为冠心病的重要遗传标记。