Evaluation of urinary selenium as a biomarker of human occupational exposure to elemental and inorganic selenium.

PURPOSE: Selenium (Se) is an essential trace element, which however, exhibits a narrow safe range of intake. Selenium also occurs at several workplaces, which results in an inhalative selenium exposure of the employees. Thus, an efficient exposure assessment strategy is demanded. The most established parameter, selenium in plasma, mostly consists of protein-bound selenium. This study aimed to investigate urinary total selenium (Se-U) as an additional biomarker of recent human occupational exposure to elemental and inorganic selenium. METHODS: Pre- and post-shift urine samples from employees with exposure to selenium-containing dust were analyzed to total selenium and compared with Se levels in urine samples from controls without occupational exposure to selenium as well as correlated with the recent ambient Se exposure by personal air monitoring. RESULTS: Se-U in post-shift samples was considerably increased compared to the levels in pre-shift samples as well as to the controls. However, Se-U in pre-shift urine was elevated compared to the Se-U in controls too. Se-U in post-shift urine and even better the shift increment in Se-U correlated with the air exposure of the present shift. A rough estimation by Se-U shift increment and external exposure accounted for an inhalative resorption rate of about 1%. CONCLUSION: Our data indicate that Se-U can display the exposure. Pre-shift Se-U levels may be based on previous exposure and indicate a slow urinary elimination kinetics. The results hint for a rather low resorption rate of selenium and inorganic selenium compounds via the lung.

Phototherapy in atopic dermatitis: a systematic review of the literature.

BACKGROUND: Phototherapy is a treatment option for atopic dermatitis recommended by several guidelines. OBJECTIVE: To perform a systematic review of the efficacy of different modalities of phototherapy and photochemotherapy in moderate to severe atopic dermatitis. MATERIAL AND METHODS: We considered all randomized clinical trials (RCTs) performed in patients with atopic dermatitis, and accepted all outcome measures. Articles were identified via an online search of the MEDLINE (via Ovid) and Embase databases and the Cochrane Central Register of Controlled Trials. We also searched for clinical trials registered in Current Controlled Trials and in the World Health Organization's International Clinical Trials Registry Platform. RESULTS: Twenty-one RCTs (961 patients) were included in the qualitative analysis. Two of the trials included children and adolescents (32 patients). The efficacy of narrow-band UV-B and UV-A1 phototherapy was similar for the different outcome measures contemplated. Two RCTs assessed the efficacy of psoralen plus UV-A therapy (PUVA). No serious adverse events were described. In general, the publications reviewed were characterized by a high risk of bias and poor reporting of methodology and results. CONCLUSIONS: There is evidence for the use of narrow-band UV-B and UV-A1 phototherapy in moderate to severe atopic dermatitis. Evidence supporting the use of PUVA in atopic dermatitis is scarce and there is little information on the use of phototherapy in childhood. For the purpose of future studies, it would be advisable to use comparable criteria and scales for the evaluation of disease severity and patients, to standardize radiation methods, and to establish a minimum follow-up time.