Skin Research and Technology最新文献

Background: Myotonometry is a noninvasive method for assessing the mechanical properties of soft tissues, including muscles and skin. The L-shaped probe, designed specifically for skin assessment, may be useful for evaluating caesarean section (C-section) scars. However, reliability data for MyotonPRO measurements of C-section scars with this probe are limited. This study aimed to evaluate the inter-rater and intra-rater reliability of measuring the mechanical properties of C-section scar skin using the MyotonPRO with the L-shaped probe.

Materials and methods: Twenty-five women (23-42 years) with C-section scars were examined. Two raters conducted the myotonometric assessments over two consecutive days. Measurements were taken with the participant supine, using the L-shaped probe at six points around the scar (three above, three below; positioned at the scar's endpoints and centre), each tested in three directions (right, left and upward/downward). Reliability was analysed using the intraclass correlation coefficient (ICC) with 95% confidence intervals (CIs), the standard error of measurement (SEM), minimal detectable change (MDC), coefficient of variation (CV) and Bland-Altman plots.

Results: Inter-rater reliability was good to excellent (ICC = 0.75-0.90), while intra-rater reliability was moderate to good, with slightly lower ICCs for consecutive-day measurements. SEM, MDC and CV values supported these findings, showing lower measurement error and narrower variability ranges between raters than within repeated measurements by the same rater.

Conclusion: The MyotonPRO with the L-shaped probe provides reliable inter- and intra-rater measurements of C-section scar skin mechanical properties, making it a valuable tool for scar evaluation.

Background: Repeated ultraviolet A (UVA) exposure-induced cellular photoaging models had been widely applicated to study skin photoaging. However, there is no standard protocol to prepare these models and cell passaging is inevitably needed when fibroblasts are cultured in conventional media for 5-7 days.

Materials and methods: The adhesion ability of fibroblasts was tested after UVA irradiation. And both the cell culture medium and the UVA dose were optimized to help fibroblasts surviving a 7-day culture period without cell subculture and to establishing an improved cellular photoaging model. Finally, senescence-associated β-galactosidase staining, intracellular reactive oxygen species (ROS) detection with the fluorescent redox probe dichlorodihydrofluorescein diacetate (DCFH-DA), and Western blot analysis were performed to compare the improved model with the classical model.

Results: UVA exposure induced a significant decrease in the adhesion ability of fibroblasts, and thus implied that cell passaging might be a screen pressure against the photodamaged cells. And fibroblasts incubated in the medium supplemented with 1% fetal calf serum could survive the 7-day culture period without cell subculture and tolerate UVA irradiation up to a dose of 5.8 J/cm² daily for 7 days. No significant differences were found between the improved model and the classical model in intracellular ROS production; however, our model demonstrated a significantly higher percentage of senescence-associated β-galactosidase positive cells. Moreover, both p53 and p21 were up-regulated in our model, while in the classical model only p21 was up-regulated.

Conclusion: An improved cellular photoaging model was established, which seems to be more suitable than the classical model for elucidating the underlying molecular mechanisms of skin photoaging.