Serine hydroxymethyltransferase isoforms are differentially inhibited by leucovorin: characterization and comparison of recombinant zebrafish serine hydroxymethyltransferases.

Serine hydroxymethyltransferase (SHMT) provides activated one-carbon units required for the biosynthesis of nucleotides, protein, and methyl group by converting serine and tetrahydrofolate to glycine and N(5),N(10)-methylenetetrahydrofolate. It is postulated that SHMT activity is associated with the development of methotrexate resistance and the in vivo activity of SHMT is regulated by the binding of N(5)-CHO-THF, the rescue agent in high-dose methotrexate chemotherapy. The aim of this study is to advance our understanding of the folate-mediated one-carbon metabolism in zebrafish by characterizing zebrafish mitochondrial SHMT. The cDNA encoding zebrafish mitochondrial SHMT was cloned, overexpressed in Escherichia coli, and purified with a three-step purification protocol. Similarities in structural, physical, and kinetic properties were revealed between the recombinant zebrafish mitochondrial SHMT and its mammalian orthologs. Surprisingly, leucovorin significantly inhibits the aldol cleavage of serine catalyzed by zebrafish cytosolic SHMT but inhibits to a lesser extent the reaction catalyzed by the mitochondrial isozyme. This is, to our knowledge, the first report on zebrafish mitochondrial folate enzyme as well as the differential inhibition of leucovorin on these two SHMT isoforms. Western blot analysis revealed tissue-specific distribution with the highest enrichment present in liver for both cytosolic and mitochondrial SHMTs. Intracellular localization was confirmed by confocal microscopy for both mitochondrial and cytosolic SHMTs. Unexpectedly, the cytosolic isoform was observed in both nucleus and cytosol. Together with the previous report on zebrafish cytosolic SHMT, we suggest that zSHMTs can be used in in vitro assays for folate-related investigation and antifolate drug discovery.     

穴位按压治疗呃逆20例

笔者采用穴位按压法治疗呃逆20例，经观察均取效迅速，且安全可靠，无副作用，现介绍如下。     

浅谈中等医药学校实习科的管理工作

对中等医药学校实习科的管理工作进行新的尝试,并提出新的管理措施,旨在通过完善的实习管理,开展各项实习工作,帮助学生巩固和掌握本专业课程应具备的基本知识和技能。     

腰椎节段形态对峡部、小关节应力及小关节接触力影响的有限元分析

目的:探讨腰椎形态结构变化对峡部裂性滑脱及小关节退变的作用和意义。方法:采用改良的“非种子区域分割方法”及非平行“最佳切割平面”等一系列新型计算机辅助设计(CAD)方法精确建立包括椎间盘高度、腰椎小关节角、椎间盘前凸角改变的L4~L5活动节段有限元模型;在2700N轴向压缩载荷条件下,分别对各有限元模型的峡部、小关节应力、小关节接触力以及椎间盘负载进行测试。结果:压缩载荷下,腰椎活动节段峡部、小关节等效应力及小关节接触力随椎间盘高度的减小而减小,随小关节角的增大而增加,随椎间盘前凸角的增加而减小。结论:椎间盘高度、腰椎小关节角、椎间盘前凸角等形态结构变化对腰椎节段有限元模型的峡部、小关节应力及小关节接触力有明显的影响。提示腰椎峡部应力性骨折及小关节退变的发生与椎间盘高度、腰椎小关节角、椎间盘前凸角等解剖形态因素有关。     

Laparoscopic Local Resection Based on Sentinel Node Evaluation for Early Gastric Cancer: A Preliminary Report

We previously reported that lymphatic mapping using isosulfan blue can be used to identify sentinel nodes (SNs). This study was undertaken to evaluate the feasibility of using the SN technique in treating early gastric cancer and to explore its usefulness for minimal invasive surgery. Twenty-three patients with early gastric cancer who underwent SN biopsy were retrospectively evaluated. Based on SN evaluation, individualized surgery was performed in five patients with T1N0M0 gastric cancer. When pathological examination of frozen sections revealed metastasis in SNs, we performed a standard D2 gastrectomy. Laparoscopic local resection was applied when the SN biopsy was negative. Our results showed that the success rate with SN biopsy in early gastric cancer was 100%, as were the accuracy, sensitivity, and specificity. All five patients with early gastric cancer had SNs negative for metastases both by frozen section and by postoperative pathology. Thus, all these patients underwent laparoscopic local resection without extended lymphadenectomy. We conclude that SN biopsy is a useful tool to individualize the operative procedure, and laparoscopic local resection can be safely performed using SN guidance in selected patients with early gastric cancer.     

自制32P敷贴器治疗瘢痕疙瘩

目的：观察自制32P敷贴器局部敷贴治疗不同类型瘢痕疙瘩的临床疗效。 方法：105例瘢痕疙瘩患者中，39例病变厚度≤ 0.3 cm的行单纯敷贴治疗，病变厚度> 0.3 cm的66例随机分为2组，单纯敷贴组36例，手术+敷贴组30例。单纯敷贴根据病变表面积大小及形状剪取敷贴片，根据剂量率和衰变校正计算每天敷贴时间，直接贴于病变表面，每天4.0~5.0 Gy/(部位•次)，连续4 d为一疗程，每疗程间隔4周，总治疗4~6个疗程。幼儿单次剂量控制在每天4 Gy/(部位•次)以下。手术+敷贴组患者手术切除瘢痕疙瘩，待手术伤口无渗出后根据伤口形状剪取敷贴片对准伤口敷贴，剂量及疗程同单纯敷贴组。 结果：单纯敷贴治疗对病变厚度≤0.3 cm的39例瘢痕疙瘩治愈32例(82%)，总有效率98%；对病变厚度> 0.3 cm的瘢痕疙瘩单纯敷贴和手术+敷贴两组治疗总有效率分别为56%和93% ，两组差异有显著性意义(P < 0.01)，其中病程< 9个月的患者治疗有效率分别为25%和75%，病程较长患者治疗有效率分别为13%和77%。治疗过程中有26例在敷帖过程中出现局部皮肤烧灼和刺痛感，均以炉甘石洗剂局部外用处理后缓解；5例出现Ⅰ度放射性皮炎，2例出现Ⅱ度放射性皮炎，以百多邦软膏局部外用后缓解，无出现Ⅲ度以上放射性皮炎病例。治愈患者局部皮肤均有不同程度的色素沉着或皮肤颜色改变。 结论：32P敷贴治疗瘢痕疙瘩治疗安全有效，对病程较短或病变厚度小于0.3 cm的患者可单纯敷贴治疗，病程较长或病变厚度大于0.3 cm患者建议先手术后再敷贴治疗。     

输尿管无细胞基质移植物的制备和评价

背景：与小肠黏膜下层等材料相比，脱细胞血管具有天然管状结构，与输尿管形态结构相近，替代输尿管时仅需端端吻合即可，手术操作简单，血管外壁光滑，获取及制备方法简便等优点。 目的：拟应用同种颈动脉血管无细胞基质体外构建输尿管。 设计、时间及地点：观察性实验，于2006-09/2008-06在上海交通大学医学院附属新华医院动物实验中心完成。 材料：长风杂交白猪由上海松联实验动物公司提供。上海交通大学医学院实验动物中心提供的健康成年大鼠8只，用于血管无细胞基质的动物毒性实验。 方法：剥去猪颈动脉血管外膜，PBS冲洗若干遍，然后将血管置于pH 7.1 的PBS中4 ℃下振荡清洗，0.5%十二烷基硫酸钠振荡24 h，后使用双蒸水4 ℃下反复振荡洗涤1周，每日换双蒸水2次。对于解剖过程中肌肉残留相对稍多的血管，在双蒸水洗涤前以混合消化液37 ℃下振荡消化约2 h，再行双蒸水洗涤。制备的无细胞基质置于青、链霉素溶液中，4 ℃保存，完成脱细胞支架制备。 主要观察指标：光镜及电镜观察脱细胞后管壁无细胞基质片的主要成分。将同种异体来源内皮祖细胞培养增殖后植入血管无细胞基质，观察细胞生长情况，并进行血管无细胞基质动物毒性实验。拉力实验了解血管无细胞基质材料的收缩性能。 结果：颈动脉血管无细胞基质中已无细胞成分，无细胞基质主要由胶原成分组成。扫描电镜未见该材料表面存在细胞及细胞碎片，同时发现该无细胞基质存在孔隙样结构。体外同种异体来源的内皮祖细胞培养增殖后植入血管无细胞基质，细胞黏附于无细胞基质。血管无细胞基质按毒性分级属于无毒级。拉力实验说明该无细胞基质具有一定的韧性和牵张性。 结论：采用胰酶和十二烷基硫酸钠制备的颈动脉血管无细胞基质材料无细胞残留，具有一定的韧性和牵张性，种植于其中的种子细胞具备一定的生长能力。     

FDA’S Perspectives on Cardiovascular Devices

The Food and Drug Administration (FDA) decision process for approving or clearing medical devices is often determined by a review of robust clinical data and extensive preclinical testing of the device. The mission statement for the Center for Devices and Radiological Health (CDRH) is to review the information provided by manufacturers so that it can promote and protect the health of the public by ensuring the safety and effectiveness of medical devices deemed appropriate for human use (Food, Drug & Cosmetic Act, §903(b)(1, 2(C)), December 31, 2004; accessed December 17, 2008 ). For high-risk devices, such as ventricular assist devices (VADs), mechanical heart valves, stents, cardiac resynchronization therapy (CRT) devices, pacemakers, and defibrillators, the determination is based on FDA’s review of extensive preclinical bench and animal testing followed by use of the device in a clinical trial in humans. These clinical trials allow the manufacturer to evaluate a device in the intended use population. FDA reviews the data from the clinical trial to determine if the device performed as predicted and the clinical benefits outweigh the risks. This article reviews the regulatory framework for different marketing applications related to cardiovascular devices and describes the process of obtaining approval to study a cardiovascular device in a U.S. clinical trial.     

100例性病患者心理健康状况调查分析

目的：探讨性病患者的心理健康状况,为临床治疗和护理提供依据。方法：采用症状自评量表（SCL-90）对100例性病患者的心理健康状况进行测验。结果：100例性病患者SCL-90检测的阳性率为51%,阳性样本因子分居前的是敌对、强迫症状、抑郁、人际敏感。结论：性病患者广泛存在的心理问题,在药用治疗的同时应注意心理方面的治疗和疏导。     

使用便携式微量输液泵持续输注氟尿嘧啶的临床观察及护理

目的：探讨使用便携式微量输液泵在肿瘤化疗中持续输注氟尿嘧啶的应用效果。方法：选取我科2006年3月-2008年7月96例癌症化疗病人按入院先后顺序分为对照组和实验组,每组48例。对照组采用传统的化疗方式,采用浅静脉留置针直接从外周静脉输注氟尿嘧啶（5-Fu）连续5天,每天维持6-8小时。实验组采用浅静脉留置针连接便携式微量输液泵持续泵入氟尿嘧啶（5-Fu）120h～135h,两组均以21天为1个周期,观察两组病人化疗毒副反应发生情况。结果：实验组化疗毒副反应发生率明显低于对照组,平均住院时间明显缩短,两组比较差异有统计学意义（P〈0.01）。结论：使用便携式微量输液泵持续泵入氟尿嘧啶能减轻病人的毒副反应,缩短住院时间,提高肿瘤病人生活质量,有效减轻护士的工作负担。