Comparison of search strategies and quality of medical information of the Internet: a study relating to ankle sprain

OBJECTIVES: to evaluate the quality of web sites on ankle sprain diagnosis and treatment and to assess the impact of Internet search expertise on quality of retrieved information. METHOD: two internet search strategies were conducted - one developed by an experienced information officer (expert's search) and the other based on the search terms used by orthopaedic medical staff (doctors' search). RESULTS: the expert's search revealed 32 web sites, of which nine were relevant, whereas the doctors' search revealed 61 web sites of which 27 were relevant. Of the relevant web sites in the expert's search, one complied with all quality criteria, whereas none of the web sites in the doctors' search complied with all criteria (11 vs. 0%, P=0.25). The web sites identified by expert's search had higher credibility (median scores 70 vs. 44, P=0.01) and accuracy of content (median scores 50 vs. 35, P=0.24). CONCLUSION: the quality of medical information on the internet is generally poor and information experts can capture higher quality web sites compared with doctors.     

胰岛干细胞来源及诱导分化与分子标记物

目的:胰岛干细胞移植是治疗糖尿病的一条新途径,可避免胰腺供体匮乏及长期使用免疫抑制剂的问题。本文对有关胰岛干细胞的来源、诱导分化及其分子标记物等研究进展做一综述。资料来源:应用计算机检索PUBMED 1997-06/2006-06期间的相关文章,检索词为“pancreatic,stem cell,differentiate,marker”,并限定文章语言种类为English。同时计算机检索万方数据库1997-06/2006-06期间的相关文章,检索词为"胰岛干细胞,诱导分化,分子标记物",并限定文章语言种类为中文。资料选择:对资料进行初审,并查看每篇文献后的引文。纳入标准:文章所述内容应与胰岛干细胞的来源、诱导分化及其分子标记物研究相关。排除标准:重复研究或Meta分析类文章。资料提炼:共收集到82篇相关文献,31篇文献符合纳入标准,排除的51篇文献为内容陈旧或重复。符合纳入标准的31篇文献中,6篇涉及主要概念,15篇涉及胰岛素分泌细胞的来源及其诱导分化,9篇涉及胰岛干细胞的分子标志,2篇涉及目前存在的问题。资料综合:干细胞是具有自我更新能力的多潜能细胞,分为胚胎干细胞和成体干细胞两大类。胰腺干细胞属于成体干细胞,能在体内分化成导管细胞、胰岛素分泌细胞、外分泌腺胞等特定胰腺组织细胞型,并具有无限分裂和永久自我更新能力。胰岛干细胞的来源、诱导分化及其分子标记物等研究对糖尿病治疗有非常重要的意义。近年研究表明:胰岛素分泌细胞主要来源于胚胎干细胞和成体干细胞,如胰腺导管上皮细胞、巢蛋白阳性胰岛前体细胞、骨髓间充质干细胞、肝脏干细胞等的诱导分化,也可利用基因工程获得。胰岛干细胞的分子标志对基础和临床研究均有重要意义,目前所使用的主要分子标志主要有PDX-1、巢蛋白、角蛋白19、角蛋白20、神经原素3、9.5蛋白基因产物等,可用于胰岛干细胞鉴定、分离及纯化。结论:胰岛细胞及干细胞移植的研究发展迅速,胰岛干细胞的来源及鉴定取得了突破性进展,但还有很多问题急需解决。随着干细胞研究的深入发展和技术的不断完善,必将能够在体外培育出数量充足的胰岛细胞供移植之用。     

Increased maternal pregnancy complications in polycystic ovary syndrome appear to be independent of obesity—A systematic review,meta‐analysis,and meta‐regression

Polycystic ovary syndrome (PCOS) is associated with an increased risk of maternal pregnancy and delivery complications. However, the impact of clinical features of PCOS and other potential risk factors in PCOS is still unknown. We aimed to investigate the association of PCOS with maternal pregnancy and delivery complications with consideration of risk factors and potential confounders. The meta‐analysis included 63 studies. PCOS was associated with higher miscarriage, gestational diabetes mellitus, gestational hypertension, pre‐eclampsia, induction of labour, and caesarean section. The association of PCOS with these outcomes varied by geographic continent, PCOS phenotypes, and study quality. Pre‐eclampsia and induction of labour were not associated with PCOS on body mass index‐matched studies. No outcome was associated with PCOS on assisted pregnancies. Age was significantly associated with higher miscarriage on meta‐regression. There were no studies assessing perinatal depression. We confirm that PCOS is associated with an increased risk of maternal pregnancy and delivery complications. The association of PCOS with the outcomes is worsened in hyperandrogenic PCOS phenotypes, in specific geographic continents, and in the highest quality studies but disappears in assisted pregnancies. Future studies in PCOS are warranted to investigate proper timing for screening and prevention of maternal pregnancy and delivery complications with consideration of clinical features of PCOS.     

FLT3 receptor expression on the surface of normal and malignant human hematopoietic cells

FLT3 ligand is a hematopoietic growth factor that plays a key role in growth of primitive hematopoietic cells. FLT3 receptor mRNA is found in early hematopoietic progenitors and in human myeloid leukemia blasts. Much less is known about the surface expression of FLT3 receptor on human hematopoietic cells. Using human 125I-FLT3 ligand, we have identified and characterized surface FLT3 receptors on normal and malignant human hematopoietic cells and cell lines. Our results showed that surface display of FLT3 receptor was greatest in fresh myeloid leukemia blast cells and myeloid leukemia cell lines. Erythroleukemic and megakaryocytic leukemia cell lines (n = 5) bound little to no 125I- FLT3 ligand. Scatchard analysis of 125I-FLT3 ligand binding data shows that three myeloid leukemia cell lines, ML-1, AML-193, and HL-60, as well as normal human marrow mononuclear cells, exhibit high affinity FLT3 receptors. Crosslinking of 125I-FLT3 ligand to FLT3 receptors on the surface of ML-1 myeloid leukemia cells indicates that the FLT3 ligand. The rates of FLT3 ligand internalization and degradation were determined by binding 125I-FLT3 ligand to ML-1 cells and acid stripping to distinguish surface bound from internalized ligand. Internalized 125I-FLT3 ligand was detected within 5 minutes after binding to ML-1 cells. In addition, we evaluated the effect of FLT3 ligand on megakaryocytic colony growth and nuclear endoreduplication, alone or in the presence of thrombopoietin. FLT3 ligand did not promote colony forming unit megakaryocyte (CFU-Meg) colony growth or megakaryocyte nuclear maturation, nor did FLT3 ligand augment the effects of thrombopoietin on these measures of megakaryopoiesis. These data indicate that the FLT3 receptor shares several characteristics with the c-kit receptor including dimerization and rapid internalization. However, the more restricted cellular distribution of the FLT3 receptor may target the effects of FLT3 ligand to primitive hematopoietic cells and to myeloid and lymphoid progenitor cells, in contrast to the pleiotropic effects of the c-kit receptor ligand, stem cell factor.