Objective Analysis of Poly-L-Lactic Acid Injection Efficacy in Different Settings.

BACKGROUND: Poly-L-lactic acid (PLLA) filler is known to have continuous volume effect. OBJECTIVE: The objective of this study is to analyze objective volume effect of PLLA in different settings of injection schedule on the cheek. METHODS: A split-face, evaluator-blind randomized study in 24 volunteers was conducted. One side was injected 3 times with 4 cc dose and the other side was injected 2 times with 6 cc dose per visit. Facial volume loss scale (FVLS) and Vectra were evaluated. RESULTS: Measured average FVLS showed statistically significant improvement both in 3 and 2 times injection sides and maintained efficacy until 12 months. Vectra showed volume difference (cc) between before and after injection. In 3 times injection side, it was increased 2.12 (after 1 month) to 3.17 (after 12 months). In 2 times injection side, it was increased 2.26 (after 1 month) to 3.19 (after 12 months). Gradual volume improvement over 12 months was statistically significant in both sides. There was no statistically significant difference between 3 and 2 times injection in FVLS and Vectra. There was no severe adverse event. CONCLUSION: Poly-L-lactic acid has continuous volume effect and there was no significant difference by injection times at the same total injection volume.

A randomized, double-blind, placebo-controlled trial of vitamin C iontophoresis in melasma.

BACKGROUND: Vitamin C is known to both inhibit melanin formation and reduce oxidized melanin. However, vitamin C does not easily penetrate the skin. In this study, vitamin C iontophoresis was employed in order to enhance vitamin C penetration. OBJECTIVE: The purpose of this study was to evaluate the efficacy of vitamin C iontophoresis for melasma patients. METHODS: Twenty-nine females with melasma were enrolled. For iontophoresis, a vitamin C solution was applied to one side of the face, while distilled water was applied to the other side as a control. The L (luminance) value was measured by a colorimeter to obtain an objective pigmentation parameter. RESULTS: Twelve weeks after iontophoresis, the colorimeter of the treated site showed a significant decrease in the L value (from 4.60 to 2.78, p = 0.002), compared to that of the control site (from 4.45 to 3.87, p = 0.142). CONCLUSION: Vitamin C iontophoresis may be an effective treatment modality for melasma.

Characterization of cryopreserved human Langerhans cells.

Epidermal Langerhans cells are potent antigen-presenting cells in the epidermis. The establishment of a cryopreservation method for human Langerhans cells would greatly contribute to our ability to successfully conduct various experiments dealing with Langerhans cells. Since Langerhans cells are known to be sensitive to cold injury, there have been no reports concerning the cryopreservation of Langerhans cells. We have investigated the effect of cryopreservation on the function and phenotype of human Langerhans cells. Langerhans cells from human foreskins were isolated with the immunomagnetic microbead method using monoclonal antibodies for CD1a. Langerhans cells were cryopreserved in the presence of dimethylsulfoxide (DMSO) 10% and fetal calf serum 90%. Cryopreserved Langerhans cells were phenotypically assessed by flowcytometry using monoclonal antibodies to HLA-DR and CD1a. The ultrastructures of the Langerhans cells were compared using electron microscopy. An autologous T cell stimulation test was performed to compare the functions of cryopreserved Langerhans cells and fresh Langerhans cells. The viability of the cryopreserved Langerhans cells was able to be maintained at more than 90%. Cryopreserved Langerhans cells expressed high levels of HLA-DR and CD1a antigens and stimulated autologous T cells to an extent almost identical to that obtained from fresh Langerhans cells. These findings indicate that the cryopreservation of human Langerhans cells could lead to a breakthrough in various experiments dealing with human Langerhans cells.

Biophysical changes after mechanical injury of the stratum corneum in normal skin.

Scrubbing off the stratum corneum with a rough towel after soaking in warm water is a bathing custom unique to Korea. However, Korean dermatologists have advised against this practice due to the potential harm that it may cause, though there is little data to support this advice. This study aimed to evaluate the changes in biophysical characteristics after such mechanical injury of stratum corneum, as reflected by water-holding capacity, stratum corneum barrier function, and stratum corneum turnover time (SCTT). 10 Korean female volunteers (aged 19-34 years) were enrolled in this study to investigate the acute effects and 32 volunteers (aged 19-49 years) the chronic effects. After soaking in warm water (36 degrees C) for 5 min, the flexor surfaces of the forearms were scrubbed with a rough towel. The volunteers' forearms were divided into 4 compartments, and each compartment was scrubbed 0, 5, 10, and 15x, respectively. After a single injury of the stratum corneum, there was an initial decrease in water-holding capacity until 6 h. Thereafter, it increased until day (D) 3, when it began to descend to the normal range. The transepidermal water loss (TEWL) values also peaked at D2 and declined thereafter. However, there were no changes in either water-holding capacity or skin barrier function, and only the SCTT was significantly shortened, after chronic injury of the stratum corneum.