PURPOSE: . This study evaluated the fracture resistance of premolar screwretained implant-supported hybrid abutment crowns (HACs) fabricated from different monolithic restorative materials following artificial aging. MATERIALS AND METHODS: . Forty-four titanium implant analogs were restored with HACs fabricated from four materials: 5 mol% yttria-partially stabilized monolithic zirconia (ST), strength-gradient multilayered zirconia (YM), lithium disilicate ceramic (LD), and resin composite containing dispersed nanoparticles (CM) (n = 11 per group). All specimens were subjected to thermocycling (10,000 cycles) and mechanical loading (1.2 million cycles) to simulate 5 years of clinical service.Fracture resistance was evaluated under compressive loading, and failure modes were analyzed using optical microscopy and scanning electron microscopy.Statistical analysis was performed using the Kruskal-Wallis and Steel-Dwass tests (α = 0.05). RESULTS: . Significant differences were found among all groups (P = 0.00033-0.0022). The YM group exhibited the highest median fracture resistance (2.06 kN, IQR: 2.00 – 2.60 kN), followed by ST (1.74 kN, IQR: 1.69 – 1.80 kN), LD (1.29 kN, IQR: 1.14 – 1.41 kN), and CM (0.87 kN, IQR: 0.79 – 0.92 kN). All specimens survived the artificial aging protocols. Distinct fracture patterns were observed depending on the restorative material, with zirconia-based groups showing more favorable resistance than resin composite. CONCLUSION . All tested HACs exhibited fracture resistance values exceeding maximum bite forces, supporting their clinical applicability. Strength-gradient multilayered zirconia demonstrated superior reliability after simulated 5-year aging, emphasizing its structural advantage and broader safety margin compared with other restorative materials.

Background/Aims: Crosstalk between the gut microbiota and bile acid plays an important role in the pathogenesis of gastrointestinal disorders. We investigated the relationship between microbial structure and bile acid metabolism in the ileal mucosa of Crohn’s disease (CD). Methods: Twelve non-CD controls and 38 CD patients in clinical remission were enrolled. Samples were collected from the distal ileum under balloon-assisted enteroscopy. Bile acid composition was analyzed by liquid chromatography-mass spectrometry. The gut microbiota was analyzed by 16S rRNA gene sequencing. Results: The Shannon evenness index was significantly lower in endoscopically active lesions than in non-CD controls. β-Diversity, evaluated by the UniFrac metric, revealed a significant difference between the active lesions and non-CD controls (P=0.039). The relative abundance of Escherichia was significantly higher and that of Faecalibacterium and Roseburia was significantly lower in CD samples than in non-CD controls. The increased abundance of Escherichia was more prominent in active lesions than in inactive lesions. The proportion of conjugated bile acids was significantly higher in CD patients than in non-CD controls, but there was no difference in the proportion of primary or secondary bile acids. The genera Escherichia and Lactobacillus were positively correlated with the proportion of conjugated bile acids. On the other hand, Roseburia, Intestinibacter, and Faecalibacterium were negatively correlated with the proportion of conjugated bile acids. Conclusions Mucosa-associated dysbiosis and the alteration of bile acid composition were identified in the ileum of CD patients. These may play a role in the pathophysiology of ileal lesions in CD patients.

Since 1999 all sixth-year students at Osaka City University Medical School have done clinical clerkships at teaching hospitals outside the university. Students can choose overseas or domestic hospitals. By the end of the 2002 academic year 32 students had done clerkships in 7 foreign countries. Arrangements for participating in overseas clerkships differ in many ways from those for domestic clerkships, as students must get information about hospitals and complete application forms in English. Because most medical students feel that making such arrangements is difficult and complex, in 2000 students established a volunteer organization that helps students to study abroad. To make the best use of this organization, Osaka City University Medical School has established several guidelines, including setting standards for students and criteria for choosing overseas hospitals. We report on some problems encountered by our school and on measures for dealing with them and report on the student-managed support organization for overseas clinical clerkships.

We performed mitral valvuloplasty for 25 months old infant with endocardial fibroelastosis (EFE) and 21 months old infant with endomyocardial fibrosis (EMF). These two patients showing good post operative cause, have been followed up during 10 and 1 years respectively. The EFE and EMF are severe and progressive restrictive cardiomyopathy of unknown etiology. Most of cases with EFE and EMF have an enlarged left ventricle with incompetent atrioventricular valve. The prognosis of these patient is usually poor. We believe that the surgical treatment in early phase may be able to improve heart failure and also to protect the progression of these disease. This case with EMF is the first report of successfull surgical treatment for the patients with severe congestive heart failure whithin one year after birth in Japan.