Photochemistry and photobiology
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Photochem. Photobiol. · Sep 2011
Association of 25-hydroxyvitamin D3)levels in adult New Zealanders with ethnicity, skin color and self-reported skin sensitivity to sun exposure.
The study aim was to determine the contribution of ethnicity, objectively measured skin color and skin reaction-to-sun exposure to variations in 25-hydroxyvitamin D(3) [25(OH)D(3) ]. A multiethnic sample (European, Maori, Pacific and Asian) of 503 adult volunteers aged 18-85 years, recruited from Auckland and Dunedin in New Zealand, answered a questionnaire on sun exposure and self-defined ethnicity. Skin color was measured using a spectrophotometer and the Individual Typology Angle (ITA) calculated. ⋯ An association also was seen between 25(OH)D(3) and skin color, with an increase of 2-3 nmol L(-1) per 10° increase in ITA value, indicating higher 25(OH)D(3) with lighter skin color; but much of this association disappeared after adjusting for ethnicity. In contrast, ethnicity remained associated with 25(OH)D(3) after adjusting for ITA skin color and skin reaction-to-sun exposure. These results indicate that self-defined ethnicity was a major determinant of variations in serum 25(OH)D(3), while objective measures of skin color explained relatively little additional variation.
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Photochem. Photobiol. · Sep 2011
A UVC device for intra-luminal disinfection of catheters: in vitro tests on soft polymer tubes contaminated with Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans.
Bacterial colonization of central venous catheters (CVCs) causes severe complications in patients. As a result, developing methods to remove and prevent bacterial and fungal colonization of CVCs is imperative. Recently, we have demonstrated that disinfection by radiation of polymer tubes with UVC light is possible. ⋯ Our results show UVC killing in a dose and time dependent manner, with no viable counts after 2 min of radiation for bacteria. Killing of C. albicans was obtained at >20 min in an UVC absorbing suspension. We believe our results to be transferable directly to the clinic, and we are currently working on a setup for clinical trial.