Dosis eritematosa mínima: correlación con el fototipo y método de medición en una muestra de población colombiana

Background and objectiveThe minimal erythema dose (MED), an essential measurement in studies of skin photosensitivity, requires establishing MED values for specific populations, given genetic variation. Different ways to assess erythema are also relevant. We aimed to determine MED values in a sample of Colombian patients and correlations between MED and Fitzpatrick skin type. We also studied concordance correlation between MEDs and two alternative ways to assess erythema.Patients and methodsCross-sectional study of 113 individuals in Bogotá, Colombia. We used a solar simulator to measure UV-A radiation and combined UV-A and UV-B (UVA + UVB) radiation, o se podría suprimir este término porque UVA y UVB son términos conocidos for MED calculation. Narrowband UV-B (NBUVB) radiation was measured in a phototherapy cabin. Erythema was assessed visually and with a Mexameter MX 18 device.ResultsThe median MEDs of UVA + UVB radiation were 22 mJ/cm² for Fitzpatrick skin types I and II, and 33 and 43 mJ/cm², respectively, for types III and IV. The MEDs of UV-A radiation were 22, 42, 86, and 100 J/cm² for types I, II, III, and IV, respectively. The MEDs of NBUVB light were 390, 550, 770, and 885 mJ/cm² for the 4 skin types. The correlation between MEDs and skin types ranged from 0.5 to 0.69. Lin's concordance correlation coefficients between visual and Mexameter assessments of erythema were greater than 0.8 in all cases.ConclusionThis study allowed us to understand MED values for UV-A, UVA + UVB, and NBUVB according to different skin types in the Colombian population. Concordance correlation coefficients between the different methods of erythema assessment were very good. Correlations between MEDs and skin types were moderate to good.     

Novel nanostructured supramolecular hydrogels for the topical delivery of anionic drugs

A bis-imidazolium-based amphiphilic molecule was used to form novel supramolecular gels in ethanol–water mixtures. The proportion of solvents, the concentration of gellant and the temperature are factors that strongly influence the gelling process. The physical gels that are formed comprise entangled fibers of around 100 nm in diameter, able to incorporate anionic drugs, whose morphology varies depending on the drug they incorporate. These hydrogels are soft and therefore optimum for skin application. They show good stability when compared to previously reported gels. Suitable drug release and skin permeation profiles were obtained, and, moreover, they seem to promote the retention of the drug inside the skin. Finally, effective in vivo anti-inflammatory activity was observed, especially with the indomethacin-incorporated gel, which indicates that these supramolecular hydrogels are a good option for the delivery of poor water soluble drugs for the treatment of acute inflammation or other skin diseases.     

自制气管套管固定装置对气管切开患者颈部皮肤保护作用观察

目的 观察自制气管套管固定装置对气管切开患者颈部皮肤的保护作用，探讨用于固定气管套管的可行性。方法60例气管切开患者采用随机数字法分为两组，每组30例。研究组使用自制气管套管固定装置固定气管套管；对照组使用传统棉布带固定。分别于固定后1、2、3周评价两组患者颈部皮损、切口皮损情况，并于第3周评价患者舒适度和家属满意度。结果研究组患者颈部皮损程度明显低于对照组，且皮损出现时间晚于对照组，差异均有统计学意义（Z=-5.183、-8.214，均P＜0.01）；切口皮损程度研究组比对照组明显减轻，差异有统计学意义（P＜0.01）；研究组患者舒适度及家属满意度分别为（7.57±1.01）、（7.77±0.86）分，对照组分别为（5.90±1.16）、（6.03±1.10）分，两组比较差异均有统计学意义（均P＜0.01）。结论使用自制的气管套管固定装置，可有效减轻患者颈部及切口皮肤损害，同时提高患者舒适度及家属满意度。