An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.     

Factors Contributing to Troponin Exchange in Myofibrils and in Solution

The troponin complex in a muscle fiber can be replaced with exogenous troponin by using a gentle exchange procedure in which the actin–tropomyosin complex is never devoid of a full complement of troponin (Brenner et al. (1999) Biophys J 77: 2677–2691). The mechanism of this exchange process and the factors that influence this exchange are poorly understood. In this study, the exchange process has now been examined in myofibrils and in solution. In myofibrils under rigor conditions, troponin exchange occurred preferentially in the region of overlap between actin and myosin when the free Ca²⁺ concentration was low. At higher concentrations of Ca²⁺, the exchange occurred uniformly along the actin. Ca²⁺ also accelerated troponin exchange in solution but the effect of S1 could not be confirmed in solution experiments. The rate of exchange in solution was insensitive to moderate changes in pH or ionic strength. Increasing the temperature resulted in a two-fold increase in rate with each 10°C increase in temperature. A sequential two step model of troponin binding to actin–tropomyosin could simulate the observed association and dissociation transients. In the absence of Ca²⁺ or rigor S1, the following rate constants could describe the binding process: k ₁ = 7.12 M^–1s^–1, k _–1 = 0.65 s^–1, k ₂ = 0.07 s^–1, k _–2 = 0.0014 s^–1. The slow rate of detachment of troponin from actin (k _–2) limits the rate of exchange in solution and most likely contributes to the slow rate of exchange in fibers.     

Protection by a taurine supplemented diet from lead-induced deficits of long-term potentiation/depotentiation in dentate gyrus of rats in vivo

Previous studies have demonstrated that synaptic plasticity, which includes long-term potentiation (LTP) and depotentiation (DP) in hippocampus, is important for learning and memory. The purpose of this study is to evaluate the effect of taurine via drinking water on the lead-induced impairments of LTP and DP in rat dentate gyrus (DG) in vivo. The experiments were carried out in four groups of rats (control, lead-exposed, control and lead-exposed with a taurine-supplement diet, respectively). The input-output (I/O) function, excitatory postsynaptic potential (EPSP) and population spike (PS) amplitude were measured in the DG area of adult rats (60-90 days) in response to stimulation applied to the lateral perforant path. The results show that: 1. chronic lead exposure impaired LTP/DP measured on both EPSP slope and PS amplitude in DG area of the hippocampus; 2. in control rats, taurine had no effect on LTP/DP; 3. the amplitudes of LTP/DP of lead-exposed group were significantly increased by applying taurine. These results suggest that dietary taurine supplement could protect rats from the lead-induced impairments of synaptic plasticity and might be a preventive medicine to cure the cognitive deficits induced by lead.     

体外免疫制备抗大肠癌循环抗原的单克隆抗体

用带结肠癌HRT-18细胞株的BALB/c(nu/nu)小鼠的血清,体处免疫BALB/c小鼠的脾细胞.再与Sp2/0细胞融合,经免疫荧光法在人结肠癌石蜡切片上筛选出一组抗结肠癌的单克隆抗体;A15-6,C13-11,H16-8。间接免疫酶法显示这组单抗对结肠癌的阳性率为69％-72％。免疫组化的特点为:癌巢分泌物及其接触的细胞膜顶端多为阳性反应,其他部位呈阴性反应。3抗体对其他类型的组织无反应。可见,这是一组针对血液循环中肿瘤相关抗原的单克隆抗体,有较好的器官特异性,可能有益于大肠癌的临床血清学检测。     

Genes of the LMP/TAP cluster are associated with the human autoimmune disease vitiligo

Genes within the class II region of the major histocompatibility complex (MHC), including genes involved in antigen processing and presentation, have been reported to be associated with several autoimmune diseases. We report here that the LMP/TAP gene region is significantly associated with vitiligo, a disorder in which biochemical defects and/or autoimmune destruction cause melanocyte loss and resulting skin depigmentation. Case/control analyses revealed genetic association of vitiligo in Caucasian patients with an early age of onset with the transporter associated with antigen processing-1 (TAP1) gene. A family-based association method revealed biased transmission of specific alleles from heterozygous parents to affected offspring for the TAP1 gene, as well as for the closely linked LMP2 and LMP7 genes encoding subunits of the immunoproteasome. No association with vitiligo was found for the MECL1 gene, which encodes a third immunoproteasome subunit and is unlinked to the MHC class II region. These results suggest a possible role for the MHC class I antigen processing and/or presentation pathway in the antimelanocyte autoimmune response involved in vitiligo pathogenesis.     

Composition of TCR-CD3 complex in human intestinal intraepithelial lymphocytes: lack of Fc{varepsilon}Rl{gamma} chain

Human intestinal intraepithelial lymphocytes (DEL) are a uniquepopulation of predominantly CD8ß⁺ TCRß⁺lymphocytes and, to a lesser extent, TCR⁺ lymphocytes that proliferatepoorly to anti-CD3 mitogenic signals but display significantcytolytic activity. Studies in mouse model systems have shownthat the chain of the high-CD3 affinity receptor for IgE (FcRl)may substitute for the chain in the TCR-CD3 complex of iIEL.This has suggested that the functional properties of these cellsmay be associated with an altered composition of the TCR-CD3complex. We therefore analyzed the TCR-CD3 complex of normalhuman iIEL. One-and two-dimensional non-reducing/reducing SDS-PAGEanalysis of CD3, CD3, CD3, and FcRr chain immunopreclpitatesof cell surface radiolabeled proteins with subunit-specificantibodies revealed a TCR-CD3 complex without associated FcRrchains. Thus, normal human NEL contain a TCR-CD3 complex thatconsists predominantly of , homodimers in association with theß TCR and CD3, and , similar to the majority of peripherallymphocytes. This indicates that the distinct properties ofhuman DEL are not associated with substitutions of the FcRlchain in the TCR-CD3 complex.     

环甲膜前部的测量及其临床意义

本文观测了40例成人尸体环甲膜前部的高度、上下宽度和血管分布：（1）环甲膜前部的高度和上、下宽度，男性分别为11．4±1.8mm、11．2±1．2mm和4．8±1．6mm；女性分别为9．6±1．7mm、9.9±1.9mm和3．7±1．1mm。男性各值均大于女性（P＜0．05）。（2）环甲动脉起自甲状腺上动脉前支，行至环甲膜前部上1／3者占94％。建议：（1）环甲膜切开术选用气管套管外径男性不应大于10mm，女性不应大于9mm；（2）横行切开环甲膜应在此膜的下份靠近环状软骨进行，以免损伤环甲动脉。     

豚鼠耳蜗微循环的检测

应用生物微球技术,结合耳蜗连续切片,直接定量检测6只正常豚鼠耳蜗血流。结果耳蜗总血流为1.662±0.262μl/min·cochlea,蜗轴、外侧壁、耳蜗隔三处血流,分别为0.955±0.272μl/min、0.654±0.272μl/min和0.053±0.060μl/min。对本实验方法和结果进行了讨论,认为用该方法检测动物的耳蜗总血流和耳蜗局部血流是准确易行的。     

穴位体表电刺激对术后PCEA的强化效应

目的　观察穴位体表电刺激对术后患者硬膜外自控镇痛（PCEA）效果、镇痛药用量、血清皮质醇浓度和不良反应的影响。方法　 选择经腹全宫切除术患者40例（ASAⅠ～Ⅱ级）,随机分成二组,每组20例。A组：于术后第4,8小时 Han's各刺激30 min,术后行PCEA。B组：单纯行术后PCEA（对照组）。术后随访镇痛效果、镇静评分、布氏舒适评分（BCS）,分段记录24 h镇痛药用量及总按压次数/实进次数（D1/D2）比值,血清皮质醇含量,肛门恢复排气时间和不良反应情况。结果　两组镇痛效果满意,A组BCS评分高于B组（P＜0.05）。A组镇痛药用量为（31.7±1.9）ml,与对照组（34.2±2.1）ml相比差异有显著性（P＜0.01）。血清皮质醇浓度两组均较术前下降,但A组术后8 h的下降幅度大于对照组。A组恢复肛门排气时间快于B组,而且恶心、呕吐与对照组相比有所减少。结论　术后患者硬膜外腔自控镇痛（PCEA）复合应用穴位体表电刺激,可增强镇痛效果,减少用药量,降低不良反应,是安全有效的复合镇痛方法。     

Observation on therapeutic effect of cold moxibustion on rheumatoid interphalangeal arthritis

目的:观察冷灸对类风湿性指间关节炎的临床疗效.方法:将576例类风湿性指间关节炎随机分为冷灸组290例和对照组286例,治疗时间为2个月.结果:两者总有效率差异不明显,但在第2个疗程末前者完全缓解率达77.2%,后者仅23.4%,两者差异有显著意义(P＜0.005).结论:冷灸治疗类风湿性指间关节炎效果优于西药抗炎剂.