ABSTRACT
Periodontal tissue has a unique structure in that the human periodontal ligament (hPDL) lies between the hard tissues of cementum and alveolar bone. Although the role of cytokines in hPDL function is not clearly understood, we investigated the effect of mechanical stress as hydrostatic pressure (HP) on cytokine expression in hPDL cells.The hPDL cells were obtained from a healthy maxillary third molar. After the 3rd to 4th passage, the cells were exposed to HP ranging from 1 MPa to 6 MPa as previously described. The expression of cytokine mRNA was determined by RT-PCR and cytokines in the culture supernatants were assessed by enzyme-linked immunosorbent assay (ELISA).The exposure to 6 MPa of HP caused no morphological changes of hPDL cells, and did not affect cellular viability. No expression of IL-1β, IL-6, IL-8, TNF-α, RANK, RANKL or OPG mRNA was observed in the control cells under atmospheric pressure, whereas in hPDL cells treated with HP, enhancement of IL-6, IL-8, RANKL and OPG mRNA expression was observed between 10 and 60 minutes after the exposure to HP. After the exposure to HP, the production of IL-6 and TNF-α were induced significantly in hPDL cells, but IL-1β and IL-8 were not produced.These results suggest that hPDL cells may play a role in the production of cytokines in response to mechanical stress <i>in vivo</i>.
ABSTRACT
A survey of physical mesurements, blood pressure, blood mesurements and frequency of food consumption was conducted on 152 males and 229 females, aged 40 to 65 years, from three rural districts in Saga prefecture. The districts were Ariake (flatland area), Kohhoku (intermediate area) and Yamanouchi (mountainous area). While, on the aged -above 70 years, a questionnaire on daily living and health condioion was investigated.<BR>The results were summarized as follows:<BR>1) The values of skinfold thickness differed little among the districts. The rate of obesity by skinfold thickness both in male and female was lower than the result of National Dietary Survey in 1981. However, the average skinfold thickness in females were higher a little compared with the values of our suruey in same region in 1971.<BR>2) The prevalence rate of anemia in females was remarkably high (below 12g/dl of hemoglobin, 34%). It presumed that agricultural work load might heavy, and nutrients intake correspond to the work load was insufficient.<BR>3) From the results of frequency of food consumption, inhabitants in Ariake compared with Kohhoku more frequently intaked modern food e. g. meat, milk. On the other hand, Kohhoku was higher in blood pressure, HDL-cholesterol/total cholesterol ratio, and lower in triglyceride, total choresterol than Ariake. We guessed that the food consumption pattern mainly affect on the results of blood pressure and serum lipids.<BR>4) In relation to the correlation matrix which calculated on all districts, the higher the obesity, the higher the blood pressure, triglyceride, total cholesterol and cholinesterase activity, whereas the obesity decreased HDL-cholesterol and HDL-cholesterol/total cholesterol ratio.<BR>5) Among 90 persons aged above 70 years, the rate of ones who can not work from physically disability, and who have any desease was 18%, 51% respectively.