Prognostic significance of different biomarkers (DNA content,PCNA, karyotype) in colorectal adenomas

Immunohistochemical detection of proliferating cell nuclear antigen (PCNA), densitometric analysis of nuclear DNA content and fluorescence in situ hybridization with centromere-specific DNA probes to chromosomes 11 and 17 were carried out on histological sections from 55 colorectal adenomas, in order to identify those adenomas that are more likely to progress to cancer. A considerable variability of PCNA positivity (range: 23-28.2%; mean value: 12.8%), a DNA indexfrom 1 to 2.3 and numerical alterations of chromosome 11 were observed. In particular, 14 out of 55 adenomas (25%), independent of histological type, degree of dysplasia, location and size, showed a DNA-aneuploid content, trisomies and tetrasomies of chromosome 11 and high PCNA index. It was concluded that the combination of some biomarkers (additional chromosomes 11, high PCNA and DNA indices) may allow identification of more aggressive colorectal adenomas with increased ability to undergo malignant transformation.     

HIV-Ⅰ CN54株gagprotease基因嵌合脊髓灰质炎病毒cDNA质粒的构建和表达研究

目的 构建HIV-1 CN54株gagprotease基因嵌合脊髓灰质炎病毒cDNA的表达质粒，并鉴定、检测基因及其表达。方法 用PCR技术获得人免疫缺陷病毒CN54株的gagprotease基因，并使其两端带上合适的酶切住点，将其定向插入到包含脊髓灰质炎病毒cDNA的表达质粒pSVA14中，替代其部分结构基因，构建HIV基因嵌合缺陷性脊髓灰质炎病毒基因组的表达质粒。经筛选、鉴定后用脂质体转染技术将新构建的质粒转入Hela细胞内，用Western Blot方法检测目的基因在Hela细胞内的表达。结果 PCR技术扩增所得的人免疫缺陷病毒CN54株gagprotease基因经琼脂糖凝胶电泳、DNA测序证实成功获得，未引入突变碱基，筛选、鉴定证明gagprotease基因被正确定向插入到脊髓灰质炎病毒的cDNA序列之中，Western Blot检测到gagpro-tcase基因正确表达了相关蛋白。结论 成功构建了表达人免疫缺陷病毒CN54株gagprotease基因的缺陷性脊髓灰质炎病毒基因组嵌合质粒，为利用脊髓灰质炎病毒作人免疫缺陷病毒基因的表达载体奠定了基础，此研究对开发以脊髓灰质炎病毒为艾滋病的疫苗载体有重要意义。     

羟基磷灰石/聚合物复合材料的研究进展

该文对羟基磷灰石与天然生物材料、人工合成的医用可生物降解高分子材料以及医用非降解高分子材料的研究应用与进展进行了总结.并对羟基磷灰石/聚合物复合材料的发展趋势进行了探讨.     

A modified Hill's procedure in the surgical treatment of hiatal hernia

After an introduction on the problems regarding indications and surgical management of gastro-oesophageal reflux disease, the Authors describe the technique they use, which is a modification of Hill's posterior gastropexy, involving the placement of suture through the median arcuate ligament, without exposing the celiac axis. The preliminary results of a prospective randomized clinical trial, conducted at the Surgical Clinic Department of Catholic University, Rome, are described. The trial evaluated early and late results of Hill's modified technique versus a control group, in which a Dor technique has been used. Intraoperative oesophageal manometry has been performed in both groups, to set the cardioplasty more properly. Ninety-one patients out of 132 have been studied; 65 had a good response to medical therapy and 26 have been operated upon. In 9 cases (6 Dor and 3 Hill) intraoperative manometry was performed. All patients have been studied pre-operatively with upper g.i. series, endoscopy with biopsies, oesophageal manometry and 24-h pH monitoring; this protocol has been repeated after 3 to 6 months postoperatively, to evaluate the results more accurately. The preliminary data, although statistically non significant because of the small study group, seem to favour the Hill modified technique, both for complication and reflux control. Further data are needed to confirm them.     

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.