Radiation protection principles observance in Iranian dental schools

In recent decades many guidelines has been conducted by radiation protection organizations about radiation protection in dentistry. This study aimed to evaluate the observance of these guidelines in educational clinics of all dental schools in Iran. In this cross-sectional study a self-administered questionnaire, based on National Radiation Protection Board [NRPB] and European Commission guidelines, was conducted. The radiology departments of all dental school [18 schools] were surveyed in this study. The questionnaire was consisted of 3 sections including intraoral radiography, extraoral radiography and implementation of quality control programs. In the case of the existence of radiation protection facilities [such as lead apron, thyroid shield and lead impacted walls] the use of high speed films and existence of automatic processor in dental schools, there was a proper condition. The main problem was related to lack of regular quality control and quality assurance programs. Digital radiography systems were employed in none of the schools and it was occasionally used for research purposes at some of them. This study has emphasized on the need for further consideration of radiation protection principles in dental schools, especially on the field of quality control and quality assurance programs

effect of ovariectomy and estrogen replacement on body weight and visceral adipose tissue in rats

Estrogen deficiency is associated with unfavorable changes in body composition and abdominal fat deposition. The consequences of these changes lead to metabolic abnormalities and differential fat distribution Seventy female Wistar rats [weight: 170.73 +/- 15.82gr mean +/- SD] were divided into 7 groups: Intact [one group],sham [two groups], ovariectomized [two groups], ovariectomized, receiving estradiol valerate[one group] and ovariectomized, receiving sesame oil [one group]. The intact rats were anesthetized and visceral fat was then taken from the abdominal cavity and weighed immediately. Two weeks after operation, one group of ovariectomized rats and one group of sham rats were sacrified and visceral fat was measured. The estradiol receiving ovariectomized group and vehicle group were given equal volumes of 17 beta-estradiol[30 micro g/kg, sc, 5 d/wk] and sesame oil for 8 weeks, respectively. After 8 weeks, all animals were sacrificied and intra- abdominal fat depots were dissected and weighed. Data were analyzed with one-way ANOVA and post-hoc and using paired t test. The differences were considered significant at P < 0.05. After two weeks of surgery, the ovariectomized rats showed insignificant increase in body weight and visceral fat weight, whereas, after eight weeks, body weight increased significantly in ovariectomized rats [P < 0.05]. Estradiol replacement decreased body weight and visceral fat weight, however this decrease was only significant in body weight [P < 0.05]. The results indicate that estrogen deficiency following ovariectomy leads to increase in both body weight and visceral fat, showing that replacement of this hormone could decrease body weight without affecting visceral fat