ABSTRACT
Night-workers experience disruption of the sleep-wake cycle and light at night which may increase breast cancer risk by suppressing the nocturnal melatonin surge, resulting in higher levels of circulating estrogens. Night-work may also deregulate peripheral clock genes which have been found to be altered in breast cancer. This study investigated urinary 6-sulfatoxymelatonin (aMT6s), serum 17-beta-estradiol levels in premenopausal shift nurses at the end of the night-shift compared to a control group of daytime nurses. Peripheral clock gene expression in lymphocytes were also investigated. All participants were sampled in the follicular phase of the menstrual cycle. The effect of nurses ability to take a short nap during the night-shift was also explored. The shift-work group had significantly lower aMT6s levels than daytime nurses independently of a nap. Night-shift napping significantly influences 17-beta-estradiol levels resulting in higher outcomes in nurses who do not take a nap compared to napping group and daytime workers. Peripheral clock genes expression investigated was not significantly different among the groups. Our findings suggest that shift nurses experience changes in aMT6s levels after a night-shift. Napping habits influence 17-beta-estradiol levels at the end of a night-shift. These findings might be related to the increased cancer risk reported in night-shift workers and suggest that a short nap during night-shifts may exert a positive effect.
Subject(s)
Circadian Clocks/genetics , Estradiol/urine , Melatonin/urine , Nurses , Premenopause/urine , Sleep , Work Schedule Tolerance , Adult , Demography , Female , Gene Expression Regulation , Humans , Melatonin/analogs & derivatives , Middle Aged , Premenopause/geneticsABSTRACT
The Authors made a transversal epidemiological study on 256 children attending the elementary schools in a commune of Siena. The subjects aged between 6 and 11 years have been examined having in view a registration of prevalence of dysgnathia problems in children.
Subject(s)
Malocclusion/epidemiology , Child , Habits , Humans , Italy/epidemiologyABSTRACT
The authors after preliminary remarks on new magnetic alloys, stress some biomechanic aspects related to distalization of upper molars. Radiologic examination of teeth during distalization shows a good rate of crown/tooth ratio movement. Where magnets were worn in combination with extraoral traction, they seemed to be more effective on the "test" sides rather than on the "control" sides where only extraoral forces acted.
Subject(s)
Magnetics , Orthodontic Appliances , Adolescent , Biomechanical Phenomena , Equipment Design , Extraoral Traction Appliances , Female , Humans , Male , Malocclusion/therapyABSTRACT
A review of the physical properties of the magnetic fields is reported. Particular attention has been paid to the biological and clinical aspects of the electromagnetic fields applied to living structures of cells and bone tissue both susceptible to this exposition.