Context: A decrease in pancreatic ␤-cell mass is involved in the development of type 2 diabetes.Objective: The purpose of this study was to evaluate the ␤-cell mass and the incidence of ␤-cell neogenesis, replication, and apoptosis at both the prediabetic and diabetic stages. Methods:We conducted a cross-sectional study of pancreatic tissues obtained from 42 patients undergoing a pancreatectomy who were classified into 4 groups: normal glucose tolerance (n ϭ 11), impaired glucose tolerance (n ϭ 11), newly diagnosed diabetes (n ϭ 10), and long-standing type 2 diabetes (n ϭ 10). Results:The relative ␤-cell area decreased and the ␤-cell apoptosis increased during the development of diabetes. The number of single and clustered ␤-cells, some of which coexpressed nestin, increased in the patients with impaired glucose tolerance and newly diagnosed diabetes. The prevalence of cells positive for both insulin and glucagon or somatostatin also increased in these patients compared with those with normal glucose tolerance. These double-positive cells were mainly localized in single and clustered ␤-cells, rather than large islets, and were also positive for Pdx1 or Ngn3. The percentage of insulin-positive cells embedded within ducts increased in the impaired glucose tolerance group. There were no significant differences in the incidence of cells positive for both insulin and Ki67 among the groups. Conclusions:These results suggest that ␤-cell neogenesis, rather than replication, predominates during impaired glucose tolerance and newly diagnosed diabetes in humans and may serve as a compensatory mechanism for the decreased ␤-cell mass.

Chronic periodontitis is a silent infectious disease prevalent worldwide and affects lifestyle-related diseases. Therefore, efficient screening of patients is essential for general health. This study was performed to evaluate prospectively the diagnostic utility of a blood IgG antibody titer test against periodontal pathogens. Oral examination was performed, and IgG titers against periodontal pathogens were measured by ELISA in 1,387 individuals. The cut-off value of the IgG titer was determined in receiver operating characteristic curve analysis, and changes in periodontal clinical parameters and IgG titers by periodontal treatment were evaluated. The relationships between IgG titers and severity of periodontitis were analyzed. The best cut-off value of IgG titer against Porphyromonas gingivalis for screening periodontitis was 1.682. Both clinical parameters and IgG titers decreased significantly under periodontal treatment. IgG titers of periodontitis patients were significantly higher than those of healthy controls, especially in those with sites of probing pocket depth over 4 mm. Multiplied cut-off values were useful to select patients with severe periodontitis. A blood IgG antibody titer test for Porphyromonas gingivalis is useful to screen hitherto chronic periodontitis patients.

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Intermittent treatment with PTH stimulated osteoblastic differentiation in fetal rat calvaria cell cultures, and topical and intermittent administration of PTH recovered alveolar bone loss in rat experimental periodontitis.