Pilot study: genetic distribution of AR, FGF5, SULT1A1 and CYP3A5 polymorphisms in male Mexican population with androgenetic alopecia.

Genetics is responsible for 80% of androgenetic alopecia (AGA) predisposition. Several single nucleotide polymorphisms (SNPs) have been linked to AGA risk and the metabolism of its first-line therapies. Genotypic and allelic frequencies have not been described in Mexican individuals; therefore, the aim of this study was to describe the genetic distribution of SNPs associated with AGA predisposition and drug metabolism. Using Real Time-PCR, we genotyped SNPs rs4827528 (AR), rs7680591 (FGF5), rs1042028, rs1042157, rs788068 and rs6839 (SULT1A1) and rs776746 (CYP3A5) in 125 (controls = 60, cases = 65) male volunteers from Northern and Western Mexico. The SULT1A1 SNPs rs1042028 (C/T) and rs788068 (T/A/C) resulted in a 100% distribution of the ancestral allele C and mutated allele A, respectively; rs1042028 diverges from the previously reported frequency, while the rs788068 ancestral allele was found to be more predominant than the reported frequency. Rs1042028, rs788068 and rs4827528, were not in Hardy-Weinberg (HW) equilibrium; conversely, rs1042157 and rs6839, rs776746, and rs7680591 followed HW principles. A statistically significant difference (P<0.05) was obtained for the rs1042157 allelic frequency between cases and controls in Western Mexico. We reported the genotypic and allelic frequencies of seven polymorphisms in Mexican individuals from Northern and Western Mexico.

Enhanced skin blood flow and sensitivity to noxious heat stimuli in papulopustular rosacea.

BACKGROUND: Although patients with rosacea often complain of increased skin sensitivity, there has been no quantitative sensory testing of this phenomenon. Furthermore, cutaneous blood flow in these patients has not been assessed using state-of-the-art laser Doppler imaging (LDI). OBJECTIVES: To assess heat pain thresholds and skin blood flow using quantitative thermal sensory testing and LDI in patients with untreated rosacea. METHODS: Of the total 24 subjects enrolled, 8 had papulopustular rosacea (PPR), 8 had erythematotelangiectatic rosacea (ETR) and 8 were control subjects. Subjective burning perception, heat pain threshold, skin blood flow, and skin temperature was assessed in all subjects. In the ETR and PPR groups, two areas were compared: affected and nonaffected. RESULTS: Heat pain thresholds of areas affected by rosacea were lower than those of nonaffected areas. In addition, subjective burning perception was increased in rosacea patients when compared with control subjects. Although PPR-affected skin had elevated skin blood flow when compared with nonaffected skin, this was not significant for ETR-affected skin. LIMITATIONS: The small number of subjects enrolled was the main limitation. CONCLUSION: This study showed enhanced sensitivity to noxious heat stimuli in rosacea-affected skin, which was more prominent in the PPR group.

Skin barrier structure and function and their relationship to pruritus in end-stage renal disease.

BACKGROUND: The relationship between dry skin and uraemic pruritus remains controversial. In addition, there is a lack of published data describing the structure and function of the stratum corneum (SC) in end-stage renal disease (ESRD). The purpose of the present study was to assess the function and structure of the skin barrier in patients with ESRD and to correlate any abnormalities with uraemic pruritus. METHODS: Thirty-eight subjects participated in the study; 20 with ESRD and 18 healthy controls. Subjects underwent evaluation of SC integrity and permeability barrier recovery, SC surface pH, pruritus and dry skin. The content of glycerol, an important endogenous humectant, was assessed in D-squame tape strips from seven patients with ESRD. Skin biopsies from six of these patients were examined by electron microscopy using ruthenium tetroxide (Ru04)-post-fixation. RESULTS: Although SC integrity was impaired in ESRD patients (P = 0.001), there were no significant differences in permeability barrier recovery rates between ESRD subjects and controls. However, there was a high significant negative correlation between SC glycerol content and dry skin in the arms of ESRD subjects (r = -0.866, P = 0.01). Yet, there was no consistent correlation between pruritus and either dry skin, SC integrity, glycerol content or surface pH. Electron microscopy revealed no significant ultra-structural abnormalities, with particular reference to the lipid bi-layer. CONCLUSIONS: SC integrity, but not permeability barrier recovery, is impaired in dialysis patients. Although dry skin in ESRD is associated with reduced SC glycerol levels, the ultra-structure appears to be unaffected.