MR imaging of blood vessels using three-dimensional reconstruction: methodology

Multisection, dual-echo magnetic resonance (MR) transaxial images of blood vessels contain both anatomic and qualitative information about flow. Even so, the images are produced as a series of two-dimensional tomographic sections from which full visualization of connected structures is difficult. A computer algorithm was developed that automatically detects flowing blood based on pixel intensity and calculated T2 and provides reconstructed views of vessels while analyzing and displaying flow characteristics. Images of abdominal vessels, aortic aneurysms, and the heart were encoded by flow and color to demonstrate depth. In addition, these data were reconstructed to derive a more accurate assessment of patency. With this technique, transaxial images can be used to analyze flow patterns, determine patent areas, and visualize all levels of vessels in a single image.     

论我国医疗美容产业的可持续发展

目的探讨我国医疗美容事业的产业化属性、经济学地位,以及如何达到全面、协调和可持续发展的大目标。方法逻辑论证。结果认识到医疗美容产业是“医疗美容经济”系统的核心要素;揭示了医疗美容产业具有“人本经济”的特征,民营医疗美容产业是发展医疗美容事业的重要力量,医疗美容产业的发展是当代中国医学美学与美容医学整体学科建设和发展的社会基础和经济基础。结论医疗美容产业的形成是医疗美容事业在社会主义市场经济条件下发展的必然趋势,同时提出了医疗美容产业健康发展的三大措施：增强产业意识;加强行业规范;实行人本管理。最终的结论是：医疗美容事业利用产业化机制,走产业化发展的道路,促进了整个社会医疗美容事业的全面、协调和可持续发展。     

Mediastinal tumors: biopsy under US guidance

Percutaneous biopsies of mediastinal tumors were successfully performed under sonographic guidance in 14 of 21 patients. In 10 of 11 malignant lesions, malignancy was determined by means of cytologic and histologic examination of the specimens obtained. A histologic diagnosis was reached in seven patients with malignant mediastinal tumors, including all four cases of Hodgkin lymphoma. Mediastinal biopsy under sonographic guidance is a technically simple, rapid, and accurate procedure, but its application is limited to tumors of the anterior mediastinum.     

Intravenous digital subtraction renal angiography: use in screening for renovascular hypertension

Intravenous digital subtraction renal angiography (DSRA) has been compared with conventional angiography only in small, selected series of hypertensive patients. The authors prospectively examined with intravenous DSRA 94 patients at increased risk for renovascular hypertension and compared these studies with conventional angiography. A stenosis of at least one main renal artery was identified with intravenous DSRA in 22 patients and confirmed in 20 patients. No significant stenoses were seen with conventional angiography in any of the 64 patients in whom lesions were not seen with intravenous DSRA. Since inadequate DSRA studies were considered positive for renal artery stenosis, the sensitivity of intravenous DSRA was 100% (25 of 25); specificity, 93% (64 of 69); positive predictive value, 83% (25 of 30); and negative predictive value, 100% (64 of 64). The authors conclude that intravenous DSRA is a sensitive test for identifying stenosis of the main renal arteries and is appropriate to use as a screening test among patients at increased risk for renovascular hypertension.     

Low prevalence of Helicobacter pylori infection in young children in the Netherlands

AIM OF THE STUDY: To investigate the seroprevalence of Helicobacter pylori infection in young children from the general population in The Netherlands. METHODS: Determination of IgG antibodies against H. pylori, using an enzyme-linked immunosorbent assay technique [cutoff 0.32 Absorption Index (AI)], in serum from 1258 children who were 2-4 years of age. The serum was obtained from a serum bank of 6127 children who attended the community child healthcare centers in the Dutch province of Zuid-Holland. RESULTS: In general, we found a seroprevalence of 1.2% of H. pylori infection, with a significant difference between the children with parents who were both Dutch (0.5%), and the children with at least one non-Dutch parent (2.6%) (P<0.001). CONCLUSIONS: The prevalence of H. pylori infection in young infants in the general population in The Netherlands is low. Children with at least one non-Dutch parent form a risk group, however, for H. pylori infection in The Netherlands.     

体外诱导骨髓间充质干细胞向神经元样细胞分化的机制研究

目的体外诱导成人骨髓间充质干细胞(MSCs)向神经元样细胞分化,并探讨分化过程中多效蛋白(PTN)mRNA的表达,以了解MSCs向神经元样细胞分化的特性和机制。方法密度梯度离心加贴壁培养法分离成人MSCs,原代和传代培养。取第6代MSCs设对照和试验组进行诱导,诱导后30 min至3 d,观察细胞形态并计数。免疫细胞化学法和反转录-聚合酶链反应(RT-PCR)法测定分化后细胞神经细胞特异性表面标志神经元烯醇化酶(NSE)、微管相关蛋白(MAP)-2,胶原酸性蛋白(GFAP)和诱导前、诱导后12 h PTN mRNA的表达。结果接种24 h后MSCs开始贴壁,呈圆形或椭圆形。3 d后可见梭状细胞呈集落状生长,10～14 d融合。第5～6代时呈现较均一的成纤维细胞样形态。诱导后胞体向胞核收缩;出现双极及多极细胞。12 h变形细胞增多,细长突起相互连接。24 h后变形细胞增多不明显。诱导后12 h大部分细胞表达NSE(64.79±0.07)%、MAP-2(60.05±0.09)%,未检测到GFAP的表达,RT-PCR半定量检测有NSE mRNA的表达(0.66±0.15)。实验组诱导后12 h细胞有PTN mRNA的表达(0.689±0.017)。结论建立了稳定的成人MSCs培养增殖体系,MSCs可体外诱导分化为神经元样细胞,在分化过程中有外观形态变化和特异性标志物NSE和MAP-2的表达,同时有PTN mRNA的表达,提示PTN可能参与调控了MSCs向神经元样细胞的分化。