Assessment of daily light and ultraviolet exposure in young adults.

PURPOSE: There are some limited reports based on questionnaire data that suggest that outdoor activity decreases the risk of myopia in children and may offset the myopia risk associated with prolonged nearwork. The aim of this study was to explore the relationship between nearwork, indoor illumination, daily sunlight, and UV exposure in emmetropic and myopic university students-given that university students perform significant amounts of nearwork and, as a group, have a high prevalence of myopia. METHODS: Participants were 35 students, aged 17 to 25 years, who were classified as being emmetropic (n = 13) or having stable (n = 12) or progressing myopia (n = 10). During waking hours on three separate days, participants wore a light sensor data logger (HOBO) and a polysulfone UV dosimeter; these devices measured daily illuminance and accumulative UV exposure, respectively. Participants also completed a daily activity log. RESULTS: No significant between-group differences were observed for average daily illuminance (p = 0.732), number of hours per day spent in sunlight (p = 0.266), outdoor shade (p = 0.726), bright indoor/dim outdoor light (p = 0.574), or dim room illumination (p = 0.484). Daily UV exposure was significantly different across the groups (p = 0.003), with stable myopes experiencing the greatest UV exposure (vs emmetropes, p = 0.002; versus progressing myopes, p = 0.004). CONCLUSIONS: The current literature suggests that there is a link between myopia protection and spending time outdoors in children. Our data provide some evidence of this relationship in young adults and highlight the need for larger studies to further investigate this relationship longitudinally.

The Effects of Periostin Expression on Fibroid-Like Transition of Myometrial Cells.

Fibroids, benign tumors of the myometrium, are the most common tumors in women and are associated with spontaneous abortion, preterm birth, placenta abruption, and infertility, among others. The incidence of fibroids in reproductive aged women is 20-89%. Fibroids are characterized by high production of extracellular matrix (ECM), particularly collagens, which play a role in their growth. However, their pathogenesis is poorly understood. Recently, we and others have found periostin (POSTN), a regulatory ECM protein, to be overexpressed in the majority of fibroids analyzed. Periostin is an ECM protein that is a critical regulator and well-established biomarker for fibrosis in tissues such as the lung, skin, and kidney. Our hypothesis was that periostin plays a role in the fibrotic transition of myometrial cells to fibroid cells. To test this, we evaluated the effects of POSTN overexpression in myometrial cells. Telomerase-immortalized myometrial cells were transduced with control or POSTN-overexpression lentivirus particles, generating one control (dCas9-Mock) and two overexpression (dCas9-POSTN-01, dCas9-POSTN-02) cell lines. Overexpression of POSTN in immortalized myometrial cells resulted in a change in phenotype consistent with fibroid cells. They upregulated expression of key fibroid genes and had increased proliferation, adhesion, and migration in vitro. Here, we show a potential role for periostin in the transition of myometrial cells to fibroid cells, giving rationale for future investigation into the role of periostin in fibroid pathogenesis and its potential as a therapeutic target.