To study the role of Pro residues in the conformation and conformational stability of a protein, nine mutant alpha subunits of tryptophan synthase from Escherichia coli, in which Ala or Gly was substituted for each of six Pro residues (positions 28, 57, 62, 96, 132, and 207) that are conserved in 10 microorganisms, were constructed by means of site-directed mutagenesis. The far-ultraviolet (UV) CD spectra of five mutant alpha subunits with Ala in place of Pro were identical to the spectrum of the wild-type protein, the exception being the mutant at position 207 (P207A). CD values in the far-UV region were less negative for P207A, indicating that the Pro residue at position 207 plays a role in maintaining the intact structure of the alpha subunit. The negative CD values of the Gly mutants examined (P28G, P96G, and P132G) were also decreased. Calorimetric measurements showed that the two mutants at position 28 (P28G and P28A) gave two peaks in the excess heat capacity curve, whereas the wild type and other Pro mutants had only a single peak. The stability of each mutant protein relative to that of the wild type was about the same for P57A, less for P62A and P132A, and markedly decreased for P96A and P207A, which are substituted at less mobile positions. The changes of denaturation entropy (delta delta dS) at the denaturation temperature of the wild-type protein (54.1 degrees C at pH 9.0) were positive for P57A, P62A, and P132A, but negative for P96A, P207A, and P132G.(ABSTRACT TRUNCATED AT 250 WORDS)

No abstract

Although conventional colonoscopy is considered the gold standard for detecting colorectal tumors, accurate staging is often difficult because advanced histology may be present in small colorectal lesions. We collected DNA present in mucosal wash fluid from patients undergoing colonoscopy and then assessed the methylation levels of four genes frequently methylated in colorectal cancers to detect invasive tumors. We found that methylation levels in wash fluid were significantly higher in patients with invasive than those with noninvasive tumors. Cytologic and K-ras mutation analyses suggested that mucosal wash fluid from invasive tumors contained greater numbers of tumor cells than wash fluid from noninvasive tumors. Among the four genes, levels of mir-34b/c methylation had the greatest correlation with the invasion and showed the largest area under the receiver operating characteristic curve (AUC ¼ 0.796). Using cutoff points of mir-34b/c methylation determined by efficiency considerations, the sensitivity/specificity were 0.861/0.657 for the 13.0% (high sensitivity) and 0.765/0.833 for the 17.8% (well-balanced) cutoffs. In the validation test set, the AUC was also very high (0.915), the sensitivity/specificity were 0.870/0.875 for 13.0% and 0.565/0.958 for 17.8%. Using the diagnostic tree constructed by an objective algorithm, the diagnostic accuracy of the invasiveness of colorectal cancer was 91.3% for the training set and 85.1% for the test set. Our results suggest that analysis of the methylation of DNA in mucosal wash fluid may be a good molecular marker for predicting the invasiveness of colorectal tumors. Cancer Prev Res; 4(5); 674-83. Ó2011 AACR.

AIM:To assess the efficacy of endocytoscopic narrowband imaging (EC-NBI) for evaluating the severity of inflammation in ulcerative colitis (UC). METHODS:This retrospective study was conducted at a single tertiary care referral center. We included UC patients who underwent colonoscopy with endocytoscopy from July 2010 to December 2013. EC-NBI was performed, and the images were evaluated by assessing visibility, increased vascularization, and the increased calibers of capillaries and were classified as Obscure, Visible or Dilated. Obscure was indicative of inactive disease, while Visible and Dilated were indicative of acute inflammation. This study received Institutional Review Board approval. The primary outcome measures included the diagnostic ability of EC-NBI to distinguish between active and inactive UC on the basis of histological activity. The conventional endoscopic images were classified according to the Mayo endoscopic score. A score of 0 or 1 indicated inactive disease, whereas a score of 2 indicated active disease. RESULTS:Fifty-two patients were enrolled. There was a strong correlation between the EC-NBI findings and the histological assessment (r = 0.871, P < 0.01).The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EC-NBI for diagnosing acute inflammation were 84.0%, 100%, 87.1%, 100%, and 92.3%, respectively, while those for the Mayo endoscopic score were 100%, 40.7%, and accuracy (P < 0.001, P = 0.001 and P = 0.047, respectively). CONCLUSION:The EC-NBI finding of capillaries in the rectal mucosa was strongly correlated with histological inflammation and aided in the differential diagnosis between active and inactive UC.

The renoportal anastomosis could be used for portal reconstruction in living-related liver transplantation for patients with a large splenorenal collateral. It provides adequate portal perfusion without interrupting collateral circulation.

We reviewed the CT examinations of 17 patients who had hepatic schistosomiasis japonica and noted peculiar hepatic calcifications in 15 cases and a notch on the hepatic surface in six. A hepatocellular carcinoma was found in six patients. The calcifications and notch appeared to indicate the degree of hepatic fibrosis but did not correlate with cirrhotic deformation.

In both HD and non-HD endoscopy, NBI is less likely than WLI to miss a lesion. Even with non-HD endoscopy, NBI is suitable for esophageal standard examinations in general hospitals.

Abstract. Na r row-band imaging (N BI) of sur face microvessels of colorectal lesions is useful for differentiating neoplasms from non-neoplasms and for predicting histopathological diagnosis. Furthermore, NBI of surface microstructure, or 'surface pattern', is valuable for predicting histopathology in colorectal cancer. The aim of the present study was to investigate whether surface patterns could be used to predict invasion depth in colorectal cancer, and to compare the accuracy of surface pattern diagnosis in each macroscopic type. Between January 2010 and March 2011, a series of 357 consecutive patients with 378 early colorectal cancers were observed by magnifying NBI and the surface pattern was prospectively evaluated. Surface pattern was classified into 3 types: type I, microstructure was clearly recognised with uniform arrangement and form; type II, microstructure was obscured with heterogeneous arrangement and form; and type III, microstructure was invisible. We also classified the macroscopic type into 3 categories: depressed, protruded and flat elevated. Assuming that type III was an index of massively invasive lesions in the submucosal layer (SMm), the sensitivity, specificity and accuracy were 56.9, 91.7 and 85.7%, respectively. The sensitivity, specificity and accuracy of type III for the diagnosis of SMm in each macroscopic type were: depressed, 88.9, 40.0 and 63.2%, respectively; protruded: 34.8, 96.4 and 90.0%, respectively; and flat elevated, 54.2, 92.7 and 85.0%, respectively. These results suggest that the diagnostic accuracy of surface pattern was insufficient and particularly poor for depressed-type lesions. IntroductionNarrow-band imaging (NBI) of surface microvessels of colorectal lesions is useful for differentiating neoplasms from non-neoplasms and for predicting histopathological diagnosis (1-8). We have reported that analysis of vascular patterns by magnifying NBI is useful for characterization of colorectal lesions (9-11). Currently, pit pattern diagnosis by magnifying chromoendoscopy is the gold standard for differentiating neoplasms from non-neoplasms and for estimating invasive depth of colorectal cancer. Type V N (non-structure) pit pattern is an index of massively invasive lesions in the submucosal layer (12-14). More recently, it was reported that evaluation of the microstructure and microvessels of the superficial layer, which can be recognised using NBI, was useful for diagnosing invasion depth of colorectal tumours (15,16). In Japan, surface microstructure observation by magnifying NBI is called 'surface pattern ' (17-20). Some reports have highlighted differences between pit structure observed by chromoendoscopy and surface pattern observed by magnifying NBI (2,(20)(21)(22). In terms of macroscopic type, when we divided the morphology of superficial colorectal lesions into protruded, flat elevated and depressed, there were differences between typical pit patterns of depressed lesions and the others (13,23,24). We hypothesised that the surface pattern could be different betwe...