Clinical implications of biofilm formation by Enterococcus faecalis in the urinary tract.

The potential relationships between biofilm formation and pathogenicity of Enterococcus faecalis in urinary tract infections (UTI) were investigated. Over a 12-year period from 1991 through 2002, a total of 352 E.faecalis isolates were collected from patients with complicated UTI (one isolate per patient) at the urology ward of Okayama University Hospital. We analyzed the prevalence and transferability of genes encoding virulence factors(asa1, esp, cylA, gelE /sprE )and antimicrobial resistance(aac(6') /aph(2'')). The production of biofilm, hemolysin and gelatinase by these isolates was also examined and the associated medical records of patients were retrospectively reviewed. Of 352 E. faecalis isolates, 315 possessed and/or genes. Of the 63 hemolysin- and 167 gelatinase-producing isolates, 59 and 94 isolates, respectively, possessed both asa1 and esp genes. E. faecalis isolates with both asa1 and esp genes formed biofilms at significantly higher rates than those with neither gene (P=0.038). The genes encoding asa1, cylA , and aac(6') /(aph(2'') were transferable and appeared to have accumulated in these isolates. The E. faecalis isolates possessing asa1 and/or esp genes were found from both catheter-related or -unrelated UTI. Our study indicates that E. faecalis isolates that have accumulated virulence genes are apt to form persistent biofilms in the urinary tracts.</p

Anti-integrin αvβ6 autoantibodies in patients with primary sclerosing cholangitis

[Background] Patients with primary sclerosing cholangitis (PSC) possess autoantibodies against biliary epithelial cells. However, the target molecules remain unknown. [Methods] The sera of patients with PSC and controls were subjected to enzyme-linked immunosorbent assays to detect autoantibodies using recombinant integrin proteins. Integrin αvβ6 expression in the bile duct tissues was examined using immunofluorescence. The blocking activity of the autoantibodies was examined using solid-phase binding assays. [Results] Anti-integrin αvβ6 antibodies were detected in 49/55 (89.1%) patients with PSC and 5/150 (3.3%) controls (P < 0.001), with a sensitivity and specificity of 89.1% and 96.7%, respectively, for PSC diagnosis. When focusing on the presence or absence of IBD, the proportion of the positive antibodies in PSC with IBD was 97.2% (35/36) and that in PSC alone was 73.7% (14/19) (P = 0.008). Integrin αvβ6 was expressed in bile duct epithelial cells. Immunoglobulin (Ig)G from 15/33 patients with PSC blocked integrin αvβ6-fibronectin binding through an RGD (Arg–Gly–Asp) tripeptide motif. [Conclusions] Autoantibodies against integrin αvβ6 were detected in most patients with PSC; anti-integrin αvβ6 antibody may serve as a potential diagnostic biomarker for PSC

Identification of an Anti–Integrin αvβ6 Autoantibody in Patients With Ulcerative Colitis

指定難病「潰瘍性大腸炎」の自己抗体発見 --新たな診断や治療開発へ--. 京都大学プレスリリース. 2021-03-09.Background and Aims: Ulcerative colitis is the most frequent type of inflammatory bowel disease and is characterized by colonic epithelial cell damage. Although involvement of autoimmunity has been suggested in ulcerative colitis, specific autoantigens/antibodies have yet to be elucidated. Methods: Using 23 recombinant integrin proteins, we performed enzyme-linked immunosorbent assays on sera from patients with ulcerative colitis and controls. Integrin expression and IgG binding in the colon tissues of patients with ulcerative colitis and controls were examined using immunofluorescence and coimmunoprecipitation, respectively. The blocking activity of autoantibodies was examined using solid-phase binding and cell adhesion assays. Results: Screening revealed that patients with ulcerative colitis had IgG antibodies against integrin αvβ6. In the training and validation groups, 103 of 112 (92.0%) patients with ulcerative colitis and only 8 of 155 (5.2%) controls had anti–integrin αvβ6 antibodies (P < .001), resulting in a sensitivity of 92.0% and a specificity of 94.8% for diagnosing ulcerative colitis. Anti–integrin αvβ6 antibody titers coincided with ulcerative colitis disease activity, and IgG1 was the major subclass. Patient IgG bound to the integrin αvβ6 expressed on colonic epithelial cells. Moreover, IgG of patients with ulcerative colitis blocked integrin αvβ6–fibronectin binding through an RGD (Arg-Gly-Asp) tripeptide motif and inhibited cell adhesion. Conclusions: A significant majority of patients with ulcerative colitis had autoantibodies against integrin αvβ6, which may serve as a potential diagnostic biomarker with high sensitivity and specificity

Acoustic Analyses of Speech Sounds and Rhythms in Japanese- and English-Learning Infants

The purpose of this study was to explore developmental changes, in terms of spectral fluctuations and temporal periodicity with Japanese- and English-learning infants. Three age groups (15, 20, and 24 months) were selected, because infants diversify phonetic inventories with age. Natural speech of the infants was recorded. We utilized a critical-band-filter bank, which simulated the frequency resolution in adults’ auditory periphery. First, the correlations between the power fluctuations of the critical-band outputs represented by factor analysis were observed in order to see how the critical bands should be connected to each other, if a listener is to differentiate sounds in infants’ speech. In the following analysis, we analyzed the temporal fluctuations of factor scores by calculating autocorrelations. The present analysis identified three factors as had been observed in adult speech at 24 months of age in both linguistic environments. These three factors were shifted to a higher frequency range corresponding to the smaller vocal tract size of the infants. The results suggest that the vocal tract structures of the infants had developed to become adult-like configuration by 24 months of age in both language environments. The amount of utterances with periodic nature of shorter time increased with age in both environments. This trend was clearer in the Japanese environment

Studies on Solanum tuberosum Agglutinin

Potato lectin (Solanum tuberosum agglutinin, STA) was purified by affinity chromatography on (GlcNAc)_3-Sepharose 6B. The molecular weight of STA was estimated to be about 100,000 by gel filtration on Sephadex G-150 in 0.05M phosphate buffered saline, pH 7.2. By sedimentation equilibrium analysis, it was shown that STA was an aggregating system with a monomer molecular weight of 54,000. Equilibrium dialysis showed that STA (dimer) has two binding sites for a specific sugar per molecule. STA had a high content of sugar, most of which was arabinose, and was rich in Hyp and Cys. Upon interaction with specific sugars, STA induced a UV-difference spectrum having positive peaks at 292nm and 285nm, which seemed to be characteristic of the tryptophyl residue. The association constants of STA with chitin oligosaccharides were determined from the intensities of the difference spectra at various concentrations of sugars. They increased with increasing chain-length of the sugar. Frontal affinity chromatography of STA was performed on columns of immobilized chitin oligosaccharides and that of chitin oligosaccharides on a column of immobilized STA. The association constants obtained with STA-Sepharose were in good agreement with those obtained by difference spectra, whereas those obtained with (GlcNAc)_2, 3-Sepharose were much higher, presumably owing to the effect of multivalency of ligands. The analyses of CD spectra of STA in the far UV region indicated the presence of approximately 40% of β and 60% of unordered form, and no evidence of α-helix conformation. This confirms the structure suggested by the unusual amino acid composition and by the high content of sugar

Chemokine CXCL16 mediates acinar cell necrosis in cerulein induced acute pancreatitis in mice

Severe acute pancreatitis is a lethal inflammatory disease frequently accompanied by pancreatic necrosis. We aimed to identify a key regulator in the development of pancreatic necrosis. A cytokine/chemokine array using sera from patients with acute pancreatitis (AP) revealed that serum CXCL16 levels were elevated according to the severity of pancreatitis. In a mouse model of AP, Cxcl16 expression was induced in pancreatic acini in the late phase with the development of pancreatic necrosis. Cxcl16⁻/⁻ mice revealed similar sensitivity as wild-type (WT) mice to the onset of pancreatitis, but better resisted development of acinar cell necrosis with attenuated neutrophil infiltration. A cytokine array and immunohistochemistry revealed lower expression of Ccl9, a neutrophil chemoattractant, in the pancreatic acini of Cxcl16⁻/⁻ mice than WT mice. Ccl9 mRNA expression was induced by stimulation with Cxcl16 protein in pancreatic acinar cells in vitro, suggesting a Cxcl16/Ccl9 cascade. Neutralizing antibody against Cxcl16 ameliorated pancreatic injury in the mouse AP model with decreased Ccl9 expression and less neutrophil accumulation. In conclusion, Cxcl16 expressed in pancreatic acini contributes to the development of acinar cell necrosis through the induction of Ccl9 and subsequent neutrophil infiltration. CXCL16 could be a new therapeutic target in AP