TRPC expression in human periodontal ligament cells and the periodontal tissue of periodontitis mice: a preliminary study / 한국실험동물학회지

Background@#Transient receptor potential canonical (TRPC) channels are non-selective cationic channels with perme‑ ability to ­Ca2+ and ­Na+ . Despite their importance, there are currently few studies on TRPC in the periodontal ligament (PDL) and bone cells in the dental field. To provide biological information regarding TRPC in PDL cells and periodontal tissue, we evaluated TRPC channels expression in the osteoblast differentiation of PDL cells and periodontitis-induced tissue. Human PDL cells were cultured in osteogenic differentiation media for 28 days, and the expression of Runx2, osteocalcin (OCN), and TRPC1, 3, 4, and 6 was evaluated by real-time PCR. In ligature-induced periodontitis mice, the alveolar bone and osteoid areas, the osteoclast number, and the expression of Runx2, OCN, TRPC3, and TRPC6 was evaluated by H&E staining, TRAP staining, and immunohistochemistry, respectively. @*Results@#In the PDL cell differentiation group, TRPC6 expression peaked on day 7 and TRPC3 expression generally increased during differentiation. During the 28 days of periodontitis progression, alveolar bone loss and osteoclast numbers increased compared to the control group during the experimental period and the osteoid area increased from day 14. TRPC6 expression in the periodontitis group increased in the PDL area and in the osteoblasts compared to the control group, whereas TRPC3 expression increased only in the PDL area on days 7 and 28. @*Conclusions@#These results indicate changes of TRPC3 and TRPC6 expression in PDL cells that were differentiating into osteoblasts and in periodontitis-induced tissue, suggesting the need for research on the role of TRPC in osteo‑ blast differentiation or periodontitis progression.

Role of γ-glutamyltranspeptidase in osteoclastogenesis induced by Fusobacterium nucleatum

We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.

Role of γ-glutamyltranspeptidase in osteoclastogenesis induced by Fusobacterium nucleatum

We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.

The Development of Korean Rehabilitation Patient Group Version 1.0 / 보건행정학회지

BACKGROUND: Rehabilitations in subacute phase are different from acute treatments regarding the characteristics and required resource consumption of the treatments. Lack of accuracy and validity of the Korean Diagnosis Related Group and Korean Out-Patient Group for the acute patients as the case-mix and payment tool for rehabilitation inpatients have been problematic issues. The objective of the study was to develop the Korean Rehabilitation Patient Group (KRPG) reflecting the characteristics of rehabilitation inpatients. METHODS: As a retrospective medical record survey regarding rehabilitation inpatients, 4,207 episodes were collected through 42 hospitals. Considering the opinions of clinical experts and the decision-tree analysis, the variables for the KRPG system demonstrating the characteristics of rehabilitation inpatients were derived, and the splitting standards of the relevant variables were also set. Using the derived variables, we have drawn the rehabilitation inpatient classification model reflecting the clinical situation of Korea. The performance evaluation was conducted on the KRPG system. RESULTS: The KRPG was targeted at the inpatients with brain or spinal cord injury. The etiologic disease, functional status (cognitive function, activity of daily living, muscle strength, spasticity, level and grade of spinal cord injury), and the patient's age were the variables in the rehabilitation patients. The algorithm of KRPG system after applying the derived variables and total 204 rehabilitation patient groups were developed. The KRPG explained 11.8% of variance in charge for rehabilitation inpatients. It also explained 13.8% of variance in length of stay for them. CONCLUSION: The KRPG version 1.0 reflecting the clinical characteristics of rehabilitation inpatients was classified as 204 groups.

The Association of Social Support with Health Status and Health Behavior among Rural Aged Population / 農村醫學 地域保健

OBJECTIVE: The objective of this study was to evaluate the association of social support with health status and health behavior. METHODS: This study was conducted with 79 elderly people in Gunja-ri, Dongsan-myun, Chuncheon. We performed face to face interview which was composed of socio-demographic characteristics, social support, health status and health behavior. The association between social support and result variables was analysed by Chi-square test and logistic regression. We used SAS ver9.1 for statistic analysis. RESULTS: Mean age of the study population was 72.0+/-7.0, social support score was 14.3+/-4.7 with full marks of 20 and 36.25% of the total population were shown to have depression. When the social support score was changed, depression (p=0.0007) and physical exercise (p=0.0312) showed significant difference. The self-rated health status was significantly related to the relationship with family members (OR=0.25, 95% CI=0.07-0.95) and the quality of sleep was also significantly associated to the relationship with family members (OR=0.21, 95% CI=0.06-0.73). The physical exercise was done significantly less in the group 'without' close friends than in the group with 'many' close friends (OR=0.21, 95% CI=0.05-0.94) and the depression was significantly more in the group without community participation than in the group with community participation (OR=4.79, 95% CI=1.62-14.15). CONCLUSIONS: Through this study, we could conclude that the social support factors are associated with health status and health behavior. Therefore, to improve the health status of rural elderly, we need to approach to develop social support.