Late atrioventricular block after heart transplantation.

Bradyarrhythmia requiring permanent pacing after heart transplantation remains a common problem. Sinus node dysfunction is the most common indication, and late onset of atrioventricular (AV) block has rarely been reported. We report the case of a patient who developed advanced AV block at 41 months after transplantation. Right bundle branch block with progressive increase of QRS complex duration was noted in serial electrocardiograms. At the time of late AV block development, the patient did not have acute rejection and coronary angiogram was normal. The mechanism of late onset of AV block is unclear, but it may be caused by progressive conduction.     

现代医学200词——138．黏附分子

所谓黏附分子是指存在于细胞表面，参与细胞间或细胞与细胞外基质的粘附的分子群的总称。广义来说，纤维连结蛋白、层粘连蛋白、透明质酸等细胞外基质的构成成分也是由细胞分泌并存在于细胞表面，也可归入黏附分子的范畴。但狭义所指的黏附分子是指贯通细胞膜的糖蛋白或构成细胞膜的糖脂质。膜贯通型糖蛋白黏附分子按其构造特征可分为若干家族。在免疫系统中的黏附分子主要分为整合素家族、免疫球蛋白超家族、选择素家族、钙粘素家族、连接蛋白家族以及唾液粘蛋白家族等。     

Fat and water separation in balanced steady-state free precession using the Dixon method.

In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.     

甲醛对小鼠致突变作用的研究

目的　研究甲醛对小鼠的致突变作用。方法　选择健康昆明种小鼠 5 0只 (雌雄各半 ) ,随机分为 3个剂量组 :甲醛高剂量组 (2 0 0 0mg/kg·bw)、中剂量组 (2 0 0mg/kg·bw)、低剂量组 (0 2 0mg/kg·bw) ,1个阴性对照组 (生理盐水 )和 1个阳性对照组 (环磷酰胺 5 0mg/kg) ,采用腹腔注射染毒 ,每天 1次 ,连续 5d。于第六天处死雌性小鼠进行骨髓细胞微核试验 ,于第三十五天处死雄性小鼠进行精子畸形试验 ,显微镜下观察并计数微核及畸形精子数。结果　甲醛中、高剂量组骨髓细胞微核数显著高于阴性对照组 (P <0 0 5 ;) ,同时低、中、高剂量组精子畸形率显著高于阴性对照组 (P <0 0 1)。结论　甲醛对小鼠具有致突变作用     

Design of a bifunctional fusion protein for ovarian cancer drug delivery: single-chain anti-CA125 core-streptavidin fusion protein.

We have developed a universal ovarian cancer cell targeting vehicle that can deliver biotinylated therapeutic drugs. A single-chain antibody variable domain (scFv) that recognizes the CA125 antigen of ovarian cancer cells was fused with a core-streptavidin domain (core-streptavidin-VL-VH and VL-VH-core-streptavidin orientations) using recombinant DNA technology and then expressed in Escherichia coli using the T7 expression system. The bifunctional fusion protein (bfFp) was expressed in a shaker flask culture, extracted from the periplasmic soluble protein, and affinity purified using an IMAC column. The two distinct activities (biotin binding and anti-CA125) of the bfFp were demonstrated using ELISA, Western blot and confocal laser-scanning microscopy (CLSM). The ELISA method utilized human NIH OVCAR-3 cells along with biotinylated bovine serum albumin (B-BSA) or biotinylated liposomes, whereas, the Western blot involved probing with B-BSA. The CLSM study has shown specificity in binding to the OVCAR-3 cell-line. ELISA and Western blot studies have confirmed the bifunctional activity and specificity. In the presence of bfFp, there was enhanced binding of biotinylated antigen and liposome to OVCAR-3 cells. In contrast, the control EMT6 cells, which do not express the CA125 antigen, showed minimal binding of the bfFp. Consequently, bfFp based targeting of biotinylated therapeutic drugs, proteins, liposomes, or nanoparticles could be an alternative, convenient method to deliver effective therapy to ovarian cancer patients. Peritoneal infusion of the bfFp-therapeutic complex could also be effective in locally targeting the most common site of metastatic spread.     

Development and optimization of an indirect enzyme-linked immunosorbent assay for the determination of Hexoestrol

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of hexoestrol (HES) was developed, optimized and validated for the analysis of HES in pork. Many parameters, such as the volume ratio of solution A and solution B, colour developing time, pH value, incubation time, the volume ratio of the standard solution and diluted antiserum, blocking solution, blocking condition, coating solution and coating condition were studied and optimized in the paper. The regression equation of the final inhibition curve is y = - 0.3345x + 1.4955, R²=0.9913. The linear range is 0.1-8.1 ng/ml, and the IC₅₀ is 0.671 ng/ml. The specificity of the assay was evaluated by the cross-reactivity rates of six compounds, of which two structurally related compounds had a relatively higher cross-reactivity rate of 25% and 6%. HES was added into a pork sample at 5 ng/g level and then the sample was extracted. The recovery is between 49.6% and 79.2%, and the variation coefficient is 0.164.     

给药系统

近年来，伴随着药物治疗的快速发展．以药理活性非常强的药物为代表，开发出许多用药时必须给予足够关注的药物，“用药最适化”这一概念逐渐成为人们非常关注的问题。这主要是为了实现用药时的最佳形式。尽可能地根据选择或者需要控制药物的浓度．时间模式。输送到药物的作用表达部位。实现治疗用药的安全性。但是，历来的方法却很难实现这一点，通过利用新的技术和方法调控药物在体内的动态变化，以获得最好治疗效果为中心的药物使用方法和药剂正在开发之中。这就是给药系统，使用可以表达自身概念的语言来命名。虽然都是以各种药物在体内的动态过程作为调控对象，但是还分为①controlled release（调控释放给药）；②开发新的给药途径、克服药物吸收障碍；③靶向给药（targeting）等三个途径。     

Chronic orchialgia: Consider gabapentin or nortriptyline before considering surgery

OBJECTIVE: To establish if there is a role for gabapentin or nortriptyline in the treatment of chronic orchialgia. METHODS: Twenty-six consecutive patients with chronic orchialgia were seen in the chronic pain clinic by a multidisciplinary team. A pain questionnaire was completed prior to commencing either gabapentin or nortriptyline. They were reviewed at 3 months and a repeat questionnaire completed. A 50% improvement in pain was considered successful. RESULTS: Complete data was available for 19 patients. Overall, 61.5% of patients commenced on gabapentin and 66.6% of patients commenced on nortriptyline had a greater than 50% improvement in pain. Patients with post-vasectomy testicular pain were considered as a subgroup. None of these patients had a greater than 50% improvement in pain. However, 80% of patients in the subgroup with idiopathic chronic orchialgia had a greater than 50% improvement in pain. CONCLUSION: Although this is a small study, it appears that gabapentin and nortriptyline are effective in the treatment of idiopathic chronic orchialgia but not post-vasectomy pain.