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The Billroth I gastric resection, with and without vagotomy, was used in 20 selected cases of peptic ulcer. Vagotomy and pyloroplasty is considered the operation of first choice for duodenal ulcer. The cases for Billroth I resections were selected from cases not suitable for pyloroplasty. Operations for peptic ulcer which preserve the gastrointestinal continuity are considered to be physiologically superior. Vagotomy and pyloroplasty, and Billroth I gastric resection both qualify in this regard. The postoperative digestive symptoms after Billroth I gastric resection in the present series were minimal, which tends to confirm this theoretical superiority.  相似文献   

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Histidine triad (HIT) proteins represent a small family of nucleotide-binding and -hydrolyzing proteins, which attracted the attention of cancer biologists because their expression is lost in multiple human malignancies. To some of the family members including Fhit, Hint1 and Hint2, a tumor suppressive activity was assigned. Although highly similar in structure, their mode of action appears to be different as they are not able to compensate each other’s function. Surprisingly, in any reported assay system the enzymatic activity of the histidine triad proteins was not required for their tumor suppressor function. Until recently, little was known about the molecular mechanisms mediating the tumor suppressor activities of histidine triad proteins. The identification of new interaction partners started to shed light on the signaling pathways modulated by the HIT proteins. Here, we summarize these findings with special emphasis on the histidine triad proteins Hint1 and Fhit and their repressive activity on the β-catenin signaling function.  相似文献   

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A key aim of evolutionary biology – inferring the action of natural selection on wild species – can be achieved by comparing neutral genetic differentiation between populations (FST) with quantitative genetic variation (QST). Each of the three possible outcomes of comparisons of QST and FST (QST FST, QST FST, QST FST) is associated with an inference (diversifying selection, genetic drift, uniform selection, respectively). However, published empirical and theoretical studies have focused on the QST FST outcome. We believe that this reflects the absence of a straightforward biological interpretation of the QST < FST pattern. We here report recent evidence of this neglected evolutionary pattern, provide guidelines to its interpretation as either a canalization phenomenon or a consequence of uniform selection and discuss the significant importance this issue will have for the area of evolutionary biology.  相似文献   

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DNA is recognized as a nanomaterial, not as a biological material, in the research field of nanotechnology. This article reviews recent research on nanowires, nanoarchitectures, computing, aptamers, biocatalysts, devices, and machines using DNA. In these works, the characteristics of DNA including facile synthesis by the solid-phase method, self-assembly, electro-conductivity, information elements, amplification, switching, molecular recognition, and catalytic functions, were appropriately applied. Multiple functions of DNA could be used simultaneously, and activated independently, by molecular switching. Therefore, the combinations of functional sequences of DNA can produce unique materials. It is obvious that the DNA molecule is one of the most promising functional nanomaterials. However, the application of DNA molecules is still under study because of the big gap that exists between theory and practice. We eagerly anticipate a ‘coming out’ of DNA due to breakthroughs in nanobiotechnology.  相似文献   

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