Ming Zhao

BACKGROUND: Predictable periodontal regeneration following periodontal disease is a major goal of therapy. The objective of this proof of concept investigation was to evaluate the ability of cementoblasts and dental follicle cells to promote periodontal regeneration in a rodent periodontal fenestration model. METHODS: The buccal aspect of the distal root of the first mandibular molar was denuded of its periodontal ligament (PDL), cementum, and superficial dentin through a bony window created bilaterally in 12 athymic rats. Treated defects were divided into three groups: 1) carrier alone (PLGA polymer sponges), 2) carrier + follicle cells, and 3) carrier + cementoblasts. Cultured murine primary follicle cells and immortalized cementoblasts were delivered to the defects via biodegradable PLGA polymer sponges, and mandibulae were retrieved 3 weeks and 6 weeks post-surgery for histological evaluation. In situ hybridization, for gene expression of bone sialoprotein (BSP) and osteocalcin (OCN), and histomorphometric analysis were further done on 3-week specimens. RESULTS: Three weeks after surgery, histology of defects treated with carrier alone indicated PLGA particles, fibrous tissue, and newly formed bone scattered within the defect area. Defects treated with carrier + follicle cells had a similar appearance, but with less formation of bone. In contrast, in defects treated with carrier + cementoblasts, mineralized tissues were noted at the healing site with extension toward the root surface, PDL region, and laterally beyond the buccal plate envelope of bone. No PDL-bone fibrous attachment was observed in any of the groups at this point. In situ hybridization showed that the mineralized tissue formed by cementoblasts gave strong signals for both BSP and OCN genes, confirming its nature as cementum or bone. The changes noted at 3 weeks were also observed at 6 weeks. Cementoblast-treated and carrier alone-treated defects exhibited complete bone bridging and PDL formation, whereas follicle cell-treated defects showed minimal evidence of osteogenesis. No new cementum was formed along the root surface in the above two groups. Cementoblast-treated defects were filled with trabeculated mineralized tissue similar to, but more mature, than that seen at 3 weeks. Furthermore, the PDL region was maintained with well-organized collagen fibers connecting the adjacent bone to a thin layer of cementum-like tissue observed on the root surface. Neoplastic changes were observed at the superficial portions of the implants in two of the 6-week cementoblast-treated specimens, possibly due in part to the SV40-transformed nature of the implanted cell line. CONCLUSIONS: This pilot study demonstrates that cementoblasts have a marked ability to induce mineralization in periodontal wounds when delivered via polymer sponges, while implanted dental follicle cells seem to inhibit periodontal healing. These results confirm the selective behaviors of different cell types in vivo and support the role of cementoblasts as a tool to better understand periodontal regeneration and cementogen-

Some recent studies have suggested that the use of dipeptidyl peptidase-4 inhibitors (DPP4i) is associated with cancer development. However, some other studies suggest no such association. The aim of the present study was to evaluate the effect of DPP4i on the risk of developing cancers. The electronic databases PubMed, Medline, EMBASE, Web of Science and Cochrane Library and the clinical trial registry were searched for published and unpublished randomized clinical trials on humans. Eligible studies were RCTs conducted in patients with type 2 diabetes mellitus, comparing DPP4i with a placebo or other active drugs. A total of 72 trials with 35,768 and 33,319 patients enrolled for DPP4i and the comparison drugs, respectively. Overall, no significant associations were detected between the use of DPP4i and cancer development, in comparison with the use of other active drugs or placebo. The results were consistent across pre-defined subgroups stratified by type of DPP4i, type of cancer, drug for comparison, trial duration, or baseline characteristics. The results of this meta-analysis suggest that patients with type 2 diabetes treated with DPP4i do not have a higher risk of developing cancers than patients treated with a placebo or other drugs.

Care for diabetic wounds remains a significant clinical problem. The present study was aimed at investigating the effect of skin gelatin from Chum Salmon on defective wound repair in the skin of diabetic rats. Full-thickness excisional skin wounds were made in 48 rats, of which 32 were diabetes. The diabetic rats were orally treated daily for 14 days with skin gelatin from Chum Salmon (2 g/kg) or its vehicle. Sixteen non-diabetic control rats received the same amount of water as vehicle-treated non-diabetic rats. Rats were killed to assess the rate of wound closure, microvessel density (MVD), vascular endothelial growth factor (VEGF), hydroxyproline (HP) contents in wound tissues and nitrate in plasma and wound tissue at 7 and 14 days after wounding. Skin gelatin-treated diabetic rats showed a better wound closure, increased MVD, VEGF, hydroxyproline and NO contents and a reduced extent of inflammatory response. All parameters were significant (P < 0.05) in comparison to vehicle-treated diabetic group. In light of our finding that skin gelatin of Chum Salmon promotes skin wound repair in diabetic rats, we propose that oral administration of Chum Salmon skin gelatin might be a beneficial method for treating wound disorders associated with diabetes.

OBJECTIVE: The aims of the study were to investigate the prevalence of pre-diabetes and explore its associated risk factors in rural areas of Ningbo, China. METHODS: A cross-sectional survey was conducted with 4583 adult residents in rural areas of Ningbo, China between March and May 2013. The survey used a multi-stage, stratified, cluster sampling method. Data collected included demographics and medical history, anthropometric measurements, blood pressure, blood lipid, and plasma glucose. After at least 10 h of overnight fasting, participants underwent an oral glucose tolerance test (OGTT) to identify pre-diabetes. Univariate and multivariate logistic regression analyses were used to evaluate the associated risk factors for pre-diabetes, and to estimate the effect of interaction between the factors. RESULTS: There were 1307 survey participants having pre-diabetes (28.52%) and the age-standardized prevalence was 30.53%. Multivariate logistic regression results showed that overweight/obesity, hypertension, and higher triglycerides were the risk factors for developing pre-diabetes. There were positive interactions between overweight/obesity and triglycerides, and also between hypertension and triglycerides on the multiplicative scale, suggesting that they synergistically influenced the development of pre-diabetes. CONCLUSIONS: The rural areas in Ningbo had a high prevalence of pre-diabetes. Overweight and obesity, hypertension, and elevated triglycerides were the major risk factors. There is a need of early intervention for preventing pre-diabetes.