Acute and long-term effects of massive balloon dilation on the aortic wall and vasa vasorum

To investigate the acute and long-term effects on the vasa vasorum after massive overdilation, canine aortic segments were dilated with Gruentzig balloon catheters to more than 100% over normal size. In the acute study, the significant lumen increase was the result of intimal and medial rupture with stretching and thinning of the adventitia. In these areas, the vasa vasorum were stretched and severed, causing adventitial hemorrhage. In the chronic study, areas of previous subtotal wall rupture with adventitial thinning were repaired by scar tissue. This repair included formation of a neomedia, hyperplasia of the adventitia, and proliferation of the vasa vasorum. No progression of luminal dilatation was seen. This study showed that in subtotal aortic wall rupture, even a severely damaged adventitia is capable of preserving the lumen from further dilatation and rupture until healing. Blood flow to the damaged vessel wall was reestablished by revascularization via capillary budding in the aortic wall.     

Dental material artifacts on MR images

Magnetic resonance (MR) imaging of the head and neck is becoming an important aid in evaluating pathologic conditions of the brain, midface, and pharynx. Certain dental materials cause artifacts during MR imaging of the lower midface. These artifacts can obscure the normal anatomy. This study describes the degree of artifact production caused by various materials commonly used in dental restorations. Of the materials tested, those causing artifacts were made of stainless steel, such as orthodontic bands used for braces, and pins or posts that are commonly drilled into teeth to provide structure or stability before filling. Materials used as temporary or permanent fillings or crowns--such as amalgam, gold alloy, aluminum, microfilled resin, and polyvinyl acrylics--did not cause artifacts in the images.     

Spinal cord compression by amyloid tissue

Spinal cord compression by a mass of amyloid tissue arising from the thoracic vertebrae is described in a 72-year-old female. Investigations failed to provide a primary cause for this amyloid tissue.     

Graphical method for comparative statistical study of vaccine potency tests

Producers and consumers are interested in some of the intrinsic characteristics of vaccine potency assays for the comparative evaluation of suitable experimental design. A graphical method is developed which represents the precision of test results, the sensitivity of such results to changes in dosage, and the relevance of the results in the way they reflect the protection afforded in the host species. The graphs can be constructed from Producer's scores and Consumer's scores on each of the scales of test score, antigen dose and probability of protection against disease. A method for calculating these scores is suggested and illustrated for single and multiple component vaccines, for tests which do or do not employ a standard reference preparation, and for tests which employ quantitative or quantal systems of scoring.     

脐血间充质干细胞分离培养的理论研究与应用

目的:间充质干细胞具有多向分化潜能,在一定的实验条件控制下可分化为骨、软骨、肌肉、神经、肝和内皮等多种细胞,本文在于进一步综合分析脐血间充质干细胞的优化分离培养条件。资料来源:应用计算机检索Medline、PubMed数据库1980-01/2006-12期间有关脐血间充质干细胞分离培养的文献,检索词“mesenchymal stem cells,human umbilical cord blood(HUCB),isolation,culture”,并限定文章语言种类为English。同时计算机检索CNKI,万方数据库1990-01/2006-12期间相关文献,限定文章语言种类为中文,检索词“间充质干细胞,脐血,分离,培养”。并手工查阅相关书籍。资料选择:检索有关脐血间充质干细胞分离培养的综述和实验论据,参考综合各文献中脐血间充质干细胞培养的方法条件,选择比较典型和比较新颖的文献进行综合。资料提炼:共检索到79篇有关脐血间充质干细胞分离纯化、培养扩增的文献,纳入30篇。资料综合:国内外有大量的实验证实,间充质干细胞具有肯定的支持造血功能,而且在一定实验条件控制下可分化为骨、软骨、脂肪、肌腱、肌肉、神经、基质、肝、内皮等多种细胞。脐血来源间充质干细胞具有低免疫原性等很多优点已成为干细胞研究领域的热点,目前分离培养间充质干细胞的方法多样,日趋成熟,但仍存在许多不足,需进一步探索间充质干细胞的分离纯化技术。结论:目前已经建立了多种脐血间充质干细胞分离纯化培养扩增的方法,为其在细胞工程和组织工程的应用提供了基础。     

A point score system for predicting the likelihood of blood transfusion after hip or knee arthroplasty

BACKGROUND: Given the high cost of autologous blood donation for elective surgery, it would be desirable to predict which patients are most likely to benefit from the procedure. The purpose of this study was to develop a point score system for predicting the likelihood of blood transfusion in hip and knee arthroplasty. STUDY DESIGN AND METHODS: A database of 599 patients undergoing elective surgery at a teaching hospital was used for the analysis. Variables were analyzed to determine their univariate association with postoperative blood transfusion. Significant factors were entered into a multiple logistic regression model, and a point score system was developed on the basis of the regression coefficients. Four strata of transfusion risk were constructed. RESULTS: Factors independently associated with blood transfusion included preoperative hemoglobin, type of arthroplasty, primary versus revision surgery, autologous donor status, and patient weight. Four factors were used to create a point score system with four strata. The likelihood of blood transfusion for patients in the four risk strata was 1.7, 11.0, 40.0, and 78.3 percent. The calculated area under the receiver operating characteristic curve was 0.86. CONCLUSION: The likelihood of a postoperative blood transfusion can be predicted by using this simple point score system. Autologous blood donation can subsequently be targeted to the high-risk patients.