METHODS: Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.
RESULTS: The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).
CONCLUSION: Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.
OBJECTIVE: This study aims to identify and compare photoaging rat models exposed to UVA and UVB.
METHODS: This research method compared macroscopic (scoring degree of wrinkling) and microscopic (histology) signs and symptoms on skin samples of rat exposed to UVA and UVB for 4 weeks at a radiation dose of 840mJ/cm2.
RESULTS: The results of this study indicated that the degree of wrinkling was highest in rat skin exposed to UVB rays by 51% (p<0.05). UVB histological results showed that the epidermis layer (40 µm, p<0.05) was thickened and the dermis layer (283 µm, p<0.05) was thinned in the skin of mice exposed to UVB light. The UVB group, showed the density of collagen in the dermis with a mean value of 55% (p<0.05).
CONCLUSION: Our results suggest that short-term exposure to UVB radiation (in the acute, subacute or subchronic phase) induces more rapid and pronounced damage to rat skin when compared to UVA radiation exposure.
OBJECTIVES: To describe the status and predictors of vitamin D status in healthy Nepalese mothers and infants.
METHODS: 500 randomly selected Nepalese mother and infant pairs were included in a cross-sectional study. Plasma 25(OH)D concentrations were measured by LC-MS/MS and multiple linear regression analyses were used to identify predictors of vitamin D status.
RESULTS: Among the infants, the prevalence of vitamin D insufficiency (25(OH)D <50 nmol/L) and deficiency (<30 nmol/L) were 3.6% and 0.6%, respectively, in contrast to 59.8% and 14.0% among their mothers. Infant 25(OH)D concentrations were negatively associated with infant age and positively associated with maternal vitamin D status and body mass index (BMI), explaining 22% of the variability in 25(OH)D concentration. Global solar radiation, maternal age and BMI predicted maternal 25(OH)D concentration, explaining 9.7% of its variability.
CONCLUSION: Age and maternal vitamin D status are the main predictors of vitamin D status in infants in Bhaktapur, Nepal, who have adequate vitamin D status despite poor vitamin D status in their mothers.