干细胞诱导分化为胰腺β细胞的研究现状

学术背景：干细胞体外诱导分化成的胰岛细胞可以发挥对血糖的生理性调节作用。大量研究证明可以从胚胎干细胞、胰腺干细胞、骨髓间充质干细胞、神经干细胞、肝脏干细胞或脐血干细胞等诱导分化出胰腺β细胞。目的：深入认识干细胞诱导分化为胰腺β细胞的研究现状。检索策略：由该论文的研究人员应用计算机检索Pubmed数据库1990—01，2006—07的相关文献，检索词“stem cell，differenliation，culture，pancreas”，并限定文章语言种类为English。同时计算机检索维普数据库2000-01，2006—07的相关文献，检索词“干细胞，胰岛，诱导分化”，并限定文章语言种类为中文。共检索到142篇文献，对资料进行初审，纳入标准：①与干细胞和干细胞向胰腺β细胞诱导分化相关的文章。②若内容相似，选取首次实验报告及近5年较权威杂志发表的文章。排除标准：重复或类似的研究。文献评价：文献的来源主要是通过对干细胞向胰腺β细胞诱导分化方面内容进行汇总分析。所选用的30篇文献中，1篇为综述，其余均为临床或基础实验研究。资料综合：胰岛移植是目前治疗Ⅰ型糖尿病和部分Ⅱ型糖尿病效果最理想的方法。由干细胞诱导分化得到的胰腺β细胞可以发挥调节血糖的作用，在许多小鼠糖尿病模型研究中起到了降低血糖的作用。目前用于诱导分化为胰腺β细胞的干细胞来源包括胚胎干细胞、胰腺干细胞、骨髓间充质干细胞、神经干细胞、肝脏干细胞或脐血干细胞等。在不同的干细胞诱导分化为胰腺β细胞的研究中，分为体内和体外两种诱导分化方法，而体外诱导法多数采用分步诱导的方式，也有部分实验利用基因技术的方法进行诱导。结论：不同来源的干细胞可以在体外通过多种方法诱导分化得到胰腺β细胞，但得到的胰腺β细胞数量及其诱导分化方法还有待进一步研究。     

急性肺损伤大鼠肺组织白细胞介素1β和肿瘤坏死因子α表达及黄芪的干预效应

目的:观察黄芪注射液对急性肺损伤时肺组织白细胞介素1β和肿瘤坏死因子α表达的影响,分析黄芪在急性肺损伤中的治疗机制。方法:实验于2005-11/2006-04在南华大学动物实验中心完成。清洁级健康SD雄性大鼠24只,以随机数字表法分3组,即对照组、模型组和黄芪组,各8只。对照组从尾静脉注入1mL生理盐水;模型组和黄芪组以内毒素5mg/kg溶解于1mL生理盐水,从尾静脉注入,制造急性肺损伤模型;45min后,黄芪组予黄芪注射液(每支10mL含20g生药,成都地奥九泓制药厂)0.5g/kg,加生理盐水稀释成1mL,并从尾静脉注入。免疫组化法检测各组肺组织白细胞介素1β和肿瘤坏死因子α的表达情况。并做肺组织大体观察和200倍光镜下观察,以胞浆出现棕黄色颗粒为阳性表达。结果:实验大鼠24只全部进入结果分析。①模型组大鼠右下肺湿质量、干质量及湿/干比值较对照组显著增加(P<0.01);黄芪组大鼠右下肺湿质量、干质量及湿/干比值较模型组明显降低(P<0.01),但仍明显高于对照组(P<0.01)。②对照组肺组织大体观察可见,表面光滑,呈淡粉红色无充血水肿及梗死灶;模型组肺组织呈现暗红色,肺包膜下明显充血水肿,广泛出血点;黄芪组大体观察同模型组。镜下观察可见,对照组肺组织结构清晰,无充血渗出,未见明显炎性细胞浸润;模型组可见肺微血管充血、出血、微血栓形成,肺间质和肺泡内有水肿液和炎症细胞浸润,部分可见灶状肺不张;黄芪组病理学改变可见肺微血管充血、出血、微血栓形成及炎症细胞浸润,但比模型组稍轻。③模型组和黄芪组白细胞介素1β和肿瘤坏死因子α的表达水平均高于对照组(P<0.01),但黄芪组白细胞介素1β和肿瘤坏死因子α的表达水平低于模型组(P<0.01)。④白细胞介素1β和肿瘤坏死因子α主要表达于肺组织的单核巨噬细胞胞浆中,呈棕黄色颗粒;模型组的表达最多,黄芪组的表达次之,对照组几乎不表达。结论:黄芪可能通过抑制白细胞介素1β、肿瘤坏死因子α等前炎性因子的表达来促进急性肺损伤的修复。     

射频皱缩刀在不同工作模式下对腋神经表面温度的影响

目的：观察肩关节镜下射频皱缩刀对腋神经表面温度的影响. 方法：实验于2005-03/06在南京医科大学附属南京第一医院骨科实验室进行.取10个新鲜肩关节标本（南京中医药大学提供）,分为肩关节持续冲洗和间断冲洗两组,模拟肩关节不稳定进行射频皱缩刀关节囊皱缩术.射频皱缩刀应用持续工作和间断工作两种不同的工作模式和1和2档能量设置,采用电动测温仪分别记录射频皱缩刀工作10,25,40,55,70 s及停止工作30 s时腋神经表面的温度. 结果：①肩关节间断冲洗组：射频皱缩刀持续工作模式下,各个时间段腋神经表面温度升高较快,2 min以后均超过70℃,最高达到85℃（3 min时）,停止工作30 s,仍为82.3℃;射频皱缩刀间断工作模式下腋神经表面温度较持续工作模式升高慢（P＜0.01）,各个时间点均不超过60℃,最高才达到58℃（70 s时）.②肩关节持续冲洗组：射频皱缩刀持续工作模式下,皱缩能量为1档和2档时,在30 s时腋神经表面的温度不差异（P＞0.05）,而连续工作1 min以上,能量为1档时,各个时间点所测温度均比能量为2档时低（P＜0.05）;射频皱缩刀间断工作模式下,皱缩能量为1档和2档时,在10,25 s时,腋神经表面温度差异不显著（P＞0.05）,40 s后,能量为1档时,腋神经表面温度比能量为2档时低（P＜0.05）.在肩关节持续冲洗和能量为1档时,射频皱缩刀在两种工作模式下,腋神经表面温度均不超过50℃. 结论：在肩关节镜下行射频皱缩术时,腋神经表面温度会明显升高,持续冲洗、间断工作模式可降低腋神经表面温度;而间断冲洗、持续工作模式可能会损伤腋神经.     

Safety and efficacy of hepatitis C virus antibody screening of blood donors with two sequential screening assays

BACKGROUND: Reactive samples in hepatitis C virus (HCV) antibody screening of blood donors are currently referred for a confirmatory assay. This scheme is not optimally efficient and is expensive because of the lack of specificity and cost of confirmatory tests, as well as the need to discard false-positive donations. As in some human immunodeficiency virus antibody-confirmatory schemes, the safety and efficacy of confirming anti-HCV with two sequential screening assays were evaluated. STUDY DESIGN AND METHODS: Three combinations of two anti-HCV screening assays were used to test 75,874 blood donors. Results were compared with the routine testing scheme and HCV RNA detection in any enzyme immunoassay-repeatably reactive samples. RESULTS: The use of an alternative screening assay for repeat testing decreased the proportion of enzyme immunoassay-positive donors from 0.28 to 0.05 percent. All samples that were "confirmed" as positive by the standard combination of immunoassays and all HCV RNA-positive samples were detected by the sequential screening assays. No samples that had discordant results on primary and secondary screening assays were confirmed by recombinant immunoblot assay or were found to contain detectable HCV RNA. CONCLUSION: The combination of screening assays for anti-HCV confirmation was as safe as, cheaper than, and nearly as efficient as the standard testing scheme.     

炎性肠病活动性的分子标志物

炎性肠病(inflammatory bowel disease,IBD)包括两个重要的肠病:溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn's disease,CD).IBD活动性的评估结果可指导临床制定治疗方案。现在临床上多采用复合指标进行评估,如:CD活动性指标、IBD研究国际分类法等。胃肠病学者希望能找到一个IBD活动性的分子标志物,有足够的特异性和灵敏度并易于监测。 1 抗体的检测 1.1 抗中性粒细胞胞质IgG抗体抗中性粒细胞胞质IgG抗体(antineutropil cytoplasmic IgG antibody,ANCA)是粒细胞特有的,最早见于血管炎,尤Wegener肉芽肿病多见,免疫荧光染色呈弥漫性胞质染色,后发现UC患者核旁ANCA染色带     

The evolving management of the third stage of labour

The immediate postpartum period is a risky period because life-threatening events can occur unexpectedly, and lead to death if they are not managed promptly. Appropriate management of the third stage of labour can reduce severe postpartum haemorrhage and death. This commentary summarizes how various management techniques of third stage of labour evolved to date and the evidence base for current international recommendations.     

Cell salvage at caesarean section: the need for an evidence-based approach

Haemorrhage, a leading cause of maternal morbidity and mortality, is frequently associated with caesarean section. Allogeneic blood is an increasingly rare and scare resource. Intraoperative Cell Salvage (IOCS) offers the possibility of improving outcome and reducing allogeneic blood transfusion in cases of haemorrhage at caesarean section. The available literature on the use of IOCS in obstetrics demonstrates that there is limited evidence to support or refute the use of IOCS at caesarean section. However, this procedure has been introduced into obstetric practice. Before opinions about its use become solidified, there is a window of opportunity to launch a large multicentre randomised controlled trial to address the current equipoise.     

Ethanol sclerotherapy: a treatment option for ovarian endometriomas before ovarian stimulation

Several surgical treatment modalities have been described in cases of isolated or multiple ovarian endometriotic cysts. The aim of this preliminary study was to investigate and test the efficacy of ethanol sclerotherapy (EST) for recurrent endometriotic cysts, before ovarian stimulation in infertile patients with an adequate ovarian status. In the setting of a prospective comparative study, EST was proposed to 31 infertile patients with recurrence of ovarian endometriomas before inclusion in assisted reproduction cycles. Reproductive outcome was compared with that of patients who had previous laparoscopic cystectomy for recurrent endometriomas. The mean size of endometriomas treated with sclerotherapy was 38.6 ± 11.2 mm in diameter. Ovarian cysts recurred in 12.9% of cases; at a mean time of 10 months after EST. Ovarian reserve and ovarian response to stimulation were better in the EST group than in the control group. Consequently, clinical and cumulative pregnancy rates of the study group were higher than those of the control group (48.3% versus 19.2%, P = 0.04; and 55.2% versus 26.9%, P = 0.03, respectively). Ethanol sclerotherapy may be a good alternative to surgical management of recurrent endometriotic cysts before assisted reproductive treatment. It could be advised for selected infertile patients.