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.     

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。     

Onychomycosis caused by Fusarium solani in a woman with diabetes

A case of untreated fusarial onychomycosis leading to serious consequences is reported. Fusarium solani is a widespread fungus and an occasional human pathogen. It usually invades rapidly in immunocompromised hosts, and often results in a poor outcome despite treatment. We report a woman with diabetes mellitus who had untreated fusarial infection of the nails, which developed into subcutaneous fusariosis, superinfected by bacteria, and then evolved into osteomyelitis that subsequently resulted in septic shock. Early management of mycotic nails in immunocompromised hosts is crucial to prevent life‐threatening disease.     

Lipid extract from completely sporoderm‐broken germinating Ganoderma sinensis spores elicits potent antitumor immune responses in human macrophages

Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd.