Modulation of Skin Collagen Metabolism in Aged and Photoaged Human Skin In Vivo

To the best of our knowledge, no study has been conducted to date to directly compare the collagen metabolism of photoaged and naturally aged human skin. In this study, we compared collagen synthesis, matrix metalloproteinase-1 levels, and gelatinase activity of sun-exposed and sun-protected skin of both young and old subjects. Using northern blot analysis, immunohistochemical stain, and Western blot analysis, we demonstrated that the levels of procollagen type I mRNA and protein in photoaged and naturally aged human skin in vivo are significantly lower than those of young skin. Furthermore, we demonstrated, by northern blot analysis, that the procollagen α1(I) mRNA expression of photoaged skin is much greater than that of sun-protected skin in the same individual. In situ hybridization and immunohistochemical stain were used to show that the expression of type I procollagen mRNA and protein in the fibroblasts of photoaged skin is greater than for naturally aged skin. In addition, it was found, by Western blot analysis using protein extracted from the dermal tissues, that the level of procollagen type I protein in photoaged skin is lower than that of naturally aged skin. The level of matrix metalloproteinase-1 protein and the activity of matrix metalloproteinase-2 were higher in the dermis of photoaged skin than in naturally aged skin. Our results suggest that the natural aging process decreases collagen synthesis and increases the expression of matrix metalloproteinases, whereas photoaging results in an increase of collagen synthesis and greater matrix metalloproteinase expression in human skin in vivo. Thus, the balance between collagen synthesis and degradation leading to collagen deficiency is different in photoaged and naturally aged skin

Exaggeration of wrinkles after botulinum toxin injection for forehead horizontal lines

There have been no long-term complications or life-threatening adverse effects related to botulinum toxin treatment for any cosmetic indications. Nevertheless, there are well-known, mild side effects of botulinum toxin treatment on the upper face, though most of them are self limited with time. However, excluding brow ptosis, reports about site specific side effects are few and anecdotal. We experienced cases of exaggeration of wrinkles after botulinum toxin injection for forehead horizontal lines, and report them here. In our cases, new appearance of a noticeable glabellar protrusion following botulinum toxin injection on the forehead was observed in 2 patients. Also, a new deep wrinkle on one side of the forehead just above the eyebrow appeared in another 2 patients. The exaggerated wrinkles nearly disappeared without treatment by week 4 in all subjects. These exaggerations of wrinkles may be caused by hyperactivity and overcompensation of untreated muscles. With the increasing availability of diverse botulinum toxin for cosmetic purposes, physicians and patients should be aware of this temporary change after therapeutic injections. We recommend explaining this possible effect prior to injection, for better understanding of treatment for cosmetic indications.OAIID:oai:osos.snu.ac.kr:snu2011-01/102/2008000790/3SEQ:3PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:NEMP_ID:A079501DEPT_CD:801CITE_RATE:.531FILENAME:botox and wrinkles.pdfDEPT_NM:의학과SCOPUS_YN:NCONFIRM:

The effects of heating and cooling on ultraviolet radiation-induced erythema and pigmentation in human skin

BACKGROUND/PURPOSE: As most biochemical systems are affected by temperature, thermal changes before or after ultraviolet (UV) irradiation could influence skin vascular blood flow changes and inflammatory responses. In this study, our aim was to investigate the influence of thermal changes on UV-induced acute skin reactions, namely, erythema and pigmentation. METHODS: Our volunteers consisted of 10 males, with ages ranging from 22 to 24 years and with Fitzpatrick's skin type III or IV. Skin temperatures were changed with a 45 degrees C heating pad or by ice pack application before or after UV irradiation (control, 1 minimal erythema dose (MED), 2 MED) and then changes in erythema and pigmentation were measured by a Minolta Spectrophotometer CM-2002. RESULTS: The present study demonstrates that both heating and cooling increase skin erythema and reduce pigmentation, and that the timing of heating and cooling influences the UV-induced skin reaction. Pre-heating and post-cooling groups showed more UV-induced erythema than the post-heating and pre-cooling groups, respectively. CONCLUSION: Our results indicate that alteration of skin surface temperature could modulate UV-induced erythema and pigmentation responses

Novel Anti-Melanogenesis Properties of Polydeoxyribonucleotide, a Popular Wound Healing Booster

Polydeoxyribonucleotide (PDRN), a deoxyribonucleotide polymer, is popularly used for faster healing of cutaneous wounds and boosting of neocollagenesis of photoaged skin among current dermatologic practitioners. Some patients receiving PDRN injection treatment also reported improvement of photoaging-associated mottled pigmentation (PMP). To investigate the effect of PDRN on cutaneous melanogenesis, we examined the effect of PDRN and an available product (Placentex®) containing PDRN on melanogenesis using human melanocytes-keratinocytes cocultures and mouse melanocytes. Melanin content, tyrosinase activity, and levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein (TRP-1) were determined. Intracellular signaling pathways were assessed by Western blotting. PDRN and Placentex® led to decreases in melanin content, tyrosinase activity, and MITF and TRP-1 expression with concomitant increases in phosphorylated forms of extracellular signal-regulated protein kinase (ERK) and AKT in mouse melanocytes. More importantly, both PDRN and Placentex® significantly suppressed the melanin content in human melanocyte–keratinocyte cocultures. Clinical evaluation of six female patients with facial hyperpigmentation after three sessions of intradermal PDRN injections using a 5-point scale revealed that PDRN led to more than noticeable improvements in hyperpigmented lesions. This is the first study to demonstrate that PDRN, which is known for its wound-healing properties, may have novel anti-melanogenesis and potential skin whitening properties

RimabotulinumtoxinB versus OnabotulinumtoxinA in the Treatment of Masseter Hypertrophy: A 24-Week Double-Blind Randomized Split-Face Study

Background: Masseter hypertrophy can be ameliorated by botulinum toxin. Objective: To compare the efficacy and safety of RimabotulinumtoxinB (BTX-B) and OnabotulinumtoxinA (BTX-A) in the treatment of masseter hypertrophy. Methods: Sixteen women with bilateral masseter hypertrophy received single injections of BTX-A or BTX-B at a dose ratio of 1:50 or 1:70 in a 24-week double-blind randomized split-face study. Results: Both BTX-A and BTX-B produced significant improvements in masseter hypertrophy. The maximum volume reduction, as determined by computed tomography scanning, at week 12 was comparable between BTX-A and BTX-B at a dose ratio of 1:70 (15.6 and 14.2%, respectively). At week 24, only masseters treated with BTX-A maintained a significant volume reduction. Investigator ratings and patient satisfaction scores paralleled objective computed tomography measurements. Conclusion: Both BTX-A and BTX-B are effective in the treatment of masseter hypertrophy. BTX-B, at a dose ratio of 1:70, has a comparable efficacy but a shorter duration of action than BTX-A. Copyright (C) 2013 S. Karger AG, BaselOAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008000790/17SEQ:17PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:YEMP_ID:A079501DEPT_CD:801CITE_RATE:2.024FILENAME:botox masseter hypertrophy.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM: