Induction of β-Defensin Expression by Porphyromonas gingivalis-Infected Human Gingival Graft Transplanted in nu/nu Mouse Subdermis

It is important to understand the onset of periodontal disease in terms of bacterial infection and host factors. Host-bacteria interactions can be elicited in human cultured cells and animal models, but these models provide only limited biological information about human host reactions against bacterial attacks. Development of an in vivo model using human gingival tissue is needed. We established an in vivo model using nu/nu mice and evaluated host defense following bacterial infection in human gingiva. Human gingival samples were collected from periodontitis patients and transplanted in nu/nu mouse subdermis. After 2 weeks, human characteristics were confirmed by positive immunohistochemical reactions for human-specific markers. We used this model to investigate human β-defensin-2 (hBD-2), an antimicrobial peptide that contributes to initial defense against bacterial invasion. Using real-time polymerase chain reaction, in situ hybridization, and immunohistochemistry, we investigated whether hBD-2 expression was induced in human gingiva as a response to Porphyromonas gingivalis as a periodontal pathogen. Two hours after infection with bacteria, we detected increased expression of hBD-2 mRNA, which was localized in the epithelium of human gingiva. Using our in vivo model, we concluded that increased hBD-2 may play an important role in early defense from bacterial infection in human gingival epithelium.     

A questionnaire-based survey on the etiopathogenesis of chronic constipation during a medical check-up in Japan

The study group of the Japanese Society of Gastroenterology released evidence-based clinical practice guidelines for chronic constipation (CC) in 2017, and irritable bowel syndrome (IBS) was treated as one of the causes of CC. We examined the differences in characteristics between IBS and non-IBS subjects with CC who underwent a medical check-up in Japan. A total of 10,658 subjects participated in this study, and we focused on 467 subjects who fulfilled the diagnostic criteria of CC using a questionnaire survey. The number of IBS subjects was 21, and they had sleep disorders, were more symptomatic (e.g., abdominal pain, abdominal bloating/distension, feeling stressed, annoyance, lack of motivation, fatigue upon waking, and feeling depressed), and had more episodes of sensation of incomplete evacuation and anorectal obstruction/blockage during defecation than non-IBS subjects. Furthermore, stool frequency of IBS subjects was significantly different from non-IBS subjects. Multivariate ordinal logistic regression analysis revealed that the factors associated with a higher stool frequency were IBS [odds ratio (OR), 2.46; 95% confidence interval (CI), 1.00–6.05; p = 0.049], male sex (OR, 1.97; 95% CI, 1.20–3.23; p = 0.007), and regular exercise (OR, 1.80; 95% CI, 1.05–3.07; p = 0.033). These findings suggest that IBS has unique characteristics in subjects with CC.     

3-dimensional composite scaffolds consisting of apatite-PLGA-atelocollagen for bone tissue engineering

We fabricated 3-dimensional scaffolds consisting of biodegradable poly(D, L-lactide-co-glycolic acid)(PLGA)(75/25) with hydroxyapatite particles containing atelocollagen (aAC). The aim of this study was to evaluate this new type of scaffold in regard to its basic properties and biocompatibility. Characterization of the obtained scaffolds was performed to know the porosity, shrinkage, diametral tensile strength, and biocompatibility. Composite scaffolds made of PLGA with hydroxyapatite particles containing atelocollagen (PL-aAC) showed a greater strength and stability than PLGA scaffolds. PL-aAC also exhibited superior performance in terms of cell attachment and proliferation as compared to PLGA, while histological findings showed that PL-aAC had an excellent response toward soft tissues. Our results strongly suggest that PL-aAC is more useful for cell transplantation as compared to PLGA for bone tissue engineering.     

Contrast‐enhanced harmonic endoscopic ultrasonography for differential diagnosis of localized gallbladder lesions

Background and Aim

Differential diagnosis of localized gallbladder lesions is challenging. The aim of the present study was to evaluate the utility of contrast‐enhanced harmonic endoscopic ultrasonography (CH‐EUS) for diagnosis of localized gallbladder lesions.

Methods

One hundred and twenty‐five patients with localized gallbladder lesions were evaluated by CH‐EUS between March 2007 and February 2014. This was a single‐center retrospective study. Utilities of fundamental B‐mode EUS (FB‐EUS) and CH‐EUS in the differentiation of gallbladder lesions and sludge plug were initially compared. Thereafter, these two examinations were compared with respect to their accuracy in the diagnosis of malignant lesions. Five reviewers blinded to the clinicopathological results evaluated microcirculation patterns in the vascular and perfusion images.

Results

In the differentiation between gallbladder lesions and sludge plug, FB‐EUS had a sensitivity, specificity, and accuracy of 82%, 100%, and 95%, respectively, whereas CH‐EUS had a sensitivity, specificity, and accuracy of 100%, 99%, and 99%, respectively. FB‐EUS‐based diagnosis of carcinomas based on tumor size and/or shape had a sensitivity, specificity, and accuracy of 61–87%, 71–88%, and 74–86%, respectively. Additional information regarding irregular vessel patterns in the vascular image and/or heterogeneous enhancement in the perfusion image on CH‐EUS increased the sensitivity, specificity, and accuracy for the diagnosis of carcinomas to 90%, 98%, and 96%, respectively. There was a significant difference between FB‐EUS and CH‐EUS in terms of carcinoma diagnosis.

Conclusion

CH‐EUS was useful for the evaluation of localized gallbladder lesions.     

The wound/burn guidelines – 2: Guidelines for the diagnosis and treatment for pressure ulcers

The Wound/Burn Guidelines Committee consists of members commissioned by the Board of Directors of the Japanese Dermatological Association (JDA). It held several meetings and evaluations in writing since October 2008, and drafted five guidelines for the diagnosis and treatment including commentaries on wounds in general and the Guidelines for the Diagnosis and Treatment for Pressure Ulcers by taking opinions of the Scientific Committee and Board of Directors of JDA into consideration.     

Characterization of Aeromonas sobria hemolysin by use of monoclonal antibodies against Aeromonas hydrophila hemolysins.

Aeromonas sobria produces hemolysin in a form activable with trypsin under defined cultural conditions. In immunoblotting analyses with the culture supernatant of A. sobria, the monoclonal antibody reacting specifically to Aeromonas hydrophila CA-11 hemolysin bound to the 53,000- and 49,000-dalton bands before and after trypsinization, respectively. The monoclonal antibody reacting to A. hydrophila AH-1 hemolysin did not bind either band. A. sobria hemolysin is, therefore, related antigenically to CA-11 hemolysin, while the molecular weights before and after activation differ from those of A. hydrophila hemolysins, being 54,000 and 51,000, respectively. The hemolytic and enterotoxigenic activities of A. sobria hemolysin were both neutralized by the monoclonal antibody against CA-11 hemolysin. It seems, therefore, that the same site on A. sobria hemolysin is responsible for both biological activities.