A novel polymorphism in the factor XIII B-subunit (His95Arg): relationship to subunit dissociation and venous thrombosis

BACKGROUND: Factor (F)XIII B-subunit, which plays a carrier role for zymogen FXIIIA, is highly polymorphic, but the molecular basis for these polymorphisms and their relationship to disease remains unknown. OBJECTIVES: To screen the FXIIIB gene coding region for common variation and analyze possible functional effects. METHODS AND RESULTS: We examined the FXIIIB gene by PCR-SSCP and identified three common single nucleotide polymorphisms: A8259G, C29470T and A30899G. A8259G results in substitution of His95Arg in the second Sushi domain. An FXIII tetramer ELISA was developed to analyze B-subunit dissociation from A-subunit (leading to access to the catalytic site of FXIII). Increased subunit dissociation, 0.51 vs. 0.45 (fraction of total tetramer), was found in plasma from subjects possessing the Arg-allele. However, when the variants were purified to homogeneity and binding was analyzed by steady-state kinetics, no difference was observed. The relationship between His95Arg and venous thrombosis was investigated in 214 patients and 291 controls from Leeds. His/Arg + Arg/Arg genotypes were more frequent in patients than controls (22.4% vs. 15.1%). His95Arg was also investigated in the Leiden Thrombophilia Study, in which a similar difference was observed for 471 patients vs. 472 controls (18.5% vs. 14.0%), for a pooled odds ratio (OR) of 1.5 (CI95 1.1-2.0). CONCLUSIONS: We have identified three FXIIIB polymorphisms, one of which codes for substitution of His95Arg. The Arg95 variant associates with a moderately increased risk for venous thrombosis, and with increased dissociation of the FXIII subunits in plasma, although in vitro steady-state binding between purified subunits was not affected.     

Biological and immunological characterization of ATG and ALG

Antithymocyte globulin (ATG) and antilymphocyte globulin (ALG) are effective therapies in aplastic anemia; their mechanism of action is undefined. We assayed multiple properties of ATG and ALG to address the biological and immunological bases for differences between ATG and ALG and lot variation. In addition, we studied a lot reported to be inactive in an American clinical trial; however in retrospect, this lot appeared to be active in patients treated in Europe. Immunoprecipitation of thymocyte and lymphocyte membrane proteins with ATG and ALG showed between 14 and 18 major bands on SDS-PAGE, but the patterns for ATG and ALG were not identical. The ability of ATG and ALG to block binding of labeled monoclonal antibodies was assessed using flow cytometry and a radioimmunoassay. In general, there was more lot variation among ALGs than ATGs; however, all ALG lots were more potent blockers of binding of anti-HLA-DR and anti-Leu 1 antibodies than was ATG. Both ALG and ATG effectively blocked binding of anti-Leu 2a, anti- Leu 3a, anti-Leu 4, anti-Leu 5b, and anti-IL 2 receptor abs; neither blocked binding of anti-Leu 7. All preparations were capable of inducing T-cell blastogenesis, although there was considerable lot variation. All lots lysed 60% to 75% T cells in a rabbit complement- mediated cytotoxicity assay, with most having a plateau of activity at 5 to 10 ug/mL. Two lots of ALG, including the lot reported to be clinically inactive, showed less toxicity at suboptimal concentrations and did not plateau even at 80 ug/mL. In total, these results indicate important differences between ATG and ALG in general, more lot variation among ALGs than ATGs and only differences in cytotoxicity between an "inactive" lot of ALG and most, but not all, other active ATG and ALG preparations.     

地理信息系统应用于血吸虫病的监测 Ⅰ.应用预测模型的可能性

目的：建立血吸虫病地理信息系统，利用气象参数建立模型来探讨预测血吸虫病的流行区的可能性。方法：以世界粮农组织出版的FAOCLIM数据库中的数据为基础，以血吸虫发育扩散关系密切的温度和潜在蒸发指数（地面水平衡系统）为基础的改良Malone公式计算血吸虫传播指数，结合AVHRR卫星图片资料，获得校正植被指数（NDVI）和第4频道地面温度指数、高程分布图，在ArcView3．0a和ERDAS软件支持下，进行GIS数据空间分析和地图重叠分析，以某一类别值显示出流行区的地理分布图。结果：血吸虫传播指数（指数值大于900）的分布基本上与中国南部地区的血吸虫病流行区相吻合。多层重叠分布图显示了红色区域的高危地区与长江流域的血吸虫病高发地区基本一致。结论：血吸虫病的流行范围与温度、高程、雨量等因素密切相关。利用气象资料模型和卫星遥感资料对预测血吸虫病的潜在流行区具有可能。准确、快速地利用AVHRR遥感资料来预测、预报血吸虫病流行范围和强度具有应用前景，值得作进一步探讨。     

H5N1亚型禽流感病毒NSl蛋白表达影响因素分析

目的 优化高表达禽流感病毒NS1蛋白的实验方法。方法将基因工程菌接种LB培养基,设定IPTG终浓度为0.3mmol／L,诱导温度为37℃,诱导表达6．0h,SDS-PAGE分析融合蛋白表达情况,确定最佳诱导时间。以o．1mm01／L为梯度,设置不同IPTG诱导浓度,37℃诱导4.0h,分析融合蛋白表达,确定最佳IPTG诱导浓度。设定IPTG至终浓度为0。6mmo1／L,分别于24℃、28℃、32℃、37℃和42℃下诱导表达4．0h,分析融合蛋白表达,确定最适诱导温度。采用最优表达条件,超声裂菌后SDS-PAGE分析融合蛋白,Westernblotting对融合蛋白进行鉴定。结果当培养温度为37℃,IPTG浓度为0。3mmol／L时,融合蛋白GST-NSl在IPTG诱导5．0h时的表达量最高,达28．5％;当IPTG诱导浓度为0。6ram01／L,在37℃诱导表达4。0h时,融合蛋白的表达量可达27．9％。选用优化的表达条件,IPTG0．6mmo1／L,37℃诱导表达4．0h,融合蛋白的表达量最高可达33．2％。进一步分析显示,融合蛋白大部分以可溶形式表达,其表达量可占菌体总蛋白的25．1％。经SDS-PAGE电泳、电转移后,用小鼠抗GST单克隆抗体进行免疫印迹分析,出现一条阳性反应带。结论通过实验优化了工程菌诱导表达的最佳IPTG浓度、最适时间和培养温度,实现了融合蛋白的可溶性高表达。     

Interventional radiologic procedures in the renal transplant

Percutaneous interventional procedures can be valuable in the evaluation and treatment of urologic complications of renal transplantation. Thirty-three patients underwent percutaneous procedures, including relief of obstruction by catheter nephrostomy, diagnostic antegrade pyelography with Whitaker testing, aspiration of various fluid collections (lymphocele, hematoma, urinoma, and abscess), and renal artery angioplasty, during a three year period at three institutions, to provide temporizing treatment and anatomic data. Surgical intervention was sometimes avoided, but more often it could be deferred to allow the patient to stabilize prior to surgery. Complications that required surgery occurred in two patients.     

Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms^-1 to 0.71 ms^-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.     

Acetylcarbocholine and acetylsilicocholine: Directly or indirectly acting cholinergic spasmogens?

The cholinergic and anticholinergic actions of nitrogen-free isosteres of acetylcholine and benzilylcholine are described. Esters of two kinds of choline analogues, carbocholine and silicocholine, were used. The spasmogenic activity of acetylcarbocholine and acetylsilicocholine on the guinea-pig ileum was identified as an indirect cholinergic action, in contrast to the direct cholinergic action of furtrethonium and the mainly non-cholinergic action of barium ions. In addition to this indirect cholinergic action, both esters show a weak anticholinergic and a weak noncompetitive “papaverine-like” spasmolytic activity. The corresponding benzilyl esters, although without an onium group, are relatively potent anticholinergic compounds.     

The surface anesthesia in outpatient pediatric department

The combination of even parts lidocaine and prilocaine in crème substance was used for surface anesthesia in 73 children, aged 1,5-16 years. Such surgical interventions as molluscum contagiosum eradication, laser wart resection and prepuce synechia dissection were performed. The described anesthetic was highly effective in all areas, but the nasolabial triangle. Resection of warts larger then 0,5 sm required either additional infiltrative anesthesia or step-wise resection. Local allergic reaction was registered in one case, no systemic reactions were noticed. Generally, the used method of surface anesthesia proved to be highly appropriate in pediatric practice.