[Show abstract][Hide abstract] ABSTRACT: Genetic factors account for the majority of differences in skin color and hair morphology across human populations. Although many studies have been conducted to examine differences in skin color across populations, few studies have examined differences in hair morphology.
To investigate changing of integral hair lipids after ultraviolet (UV) irradiation in three human ethnic groups.
We studied the UV irradiation induced hair damage in hairs of three human populations. UV irradiation had been performed with self-manufactured phototherapy system. Damaged hair samples were prepared at 12 and 48 hours after UVA (20 J/sec) and UVB (8 J/sec) irradiation. We evaluated the changes of hair lipid using scanning electron microscopy (SEM), transmission electron microscopy (TEM), lipid TEM and HP-TLC. After UV irradiation, hair surface damage was shown.
African hair showed more severe damage on hair surface than others. The lipid compositions across human populations were similar, but Asian hair had more integral hair lipids than other groups as a whole. Especially, free fatty acid contents were higher than other lipids. After UV irradiation, lipid contents were decreased. These patterns were shown in all human populations. Asian hair has more integral hair lipid than European or African hair. After UV irradiation, European and African hair samples exhibited more damage because they have less integral hair lipids. However, Asian hair samples have less damage.
We conclude that integral hair lipid may protect the hair against the UV light.
Preview · Article · Feb 2013 · Annals of Dermatology
[Show abstract][Hide abstract] ABSTRACT: Pattern hair loss (PHL) is the most common form of baldness in both sexes. The Norwood-Hamilton classification is the most commonly used classification worldwide, but it has many limitations. The basic and specific (BASP) classification was introduced as an improvement over the Norwood-Hamilton classification. Previous research was done to estimate the reliability of the Norwood-Hamilton classification and the result was unsatisfactory. However, the reliability of the BASP and Norwood-Hamilton classifications has not yet been compared. Eight dermatological specialists, 17 dermatological residents and 15 general physicians classified PHL in 100 sets of photographs using both the BASP and Norwood-Hamilton classifications. Intergroup reproducibility was evaluated by examining the match rate of the individual data in each group and the match rate between hair specialist and the other examiners. Intragroup repeatability was determined by calculating the match rate between the first and second studies. In terms of intergroup reproducibility of the match rate for individual data in each group, the basic type had the best agreement, the specific type had the second best, and the Norwood-Hamilton classification had the lowest match rate. In comparison, hair specialist and intragroup repeatability showed the same patterns. The BASP classification not only distinguishes all kinds of hair loss patterns, but also has better reproducibility and repeatability than the Norwood-Hamilton classification.
No preview · Article · Oct 2012 · The Journal of Dermatology
[Show abstract][Hide abstract] ABSTRACT: The mechanisms and inheritance of androgenetic alopecia (AGA) have yet to be elucidated. Several clinical studies suggest that a predisposition to AGA is affected by a variety of paternal and/or maternal hereditary factors. No previous study has addressed the association of AGA with family history based on the pattern of hair loss.
The purpose of this study was to investigate paternal and/or maternal genetic influences in each type of hair loss pattern using the basic and specific (BASP) classification and to explore whether the morphology of AGA tends to be inherited in family members.
Between October 2007 and September 2008, 1220 Korean participants, 998 male and 222 female, were classified according to the BASP classification at 13 university dermatologic centers. Information was collected using a standard questionnaire and BASP classification sheet.
Parental influences on anterior hairline shape in men were predominantly from the paternal side, whereas these effects were less notable in women. In the absence of a family history, statistical analysis showed a higher frequency for early-onset AGA than late-onset AGA (Pearson χ(2)P < .05). Basic types of hair loss had a higher degree of inheritance from the paternal side of the family, regardless of specific type.
The evaluation of hair loss pattern and family history was done by the patients.
Familial factors affecting the morphology of AGA differ between male and female individuals, and for each type of BASP classification.
No preview · Article · Mar 2011 · Journal of the American Academy of Dermatology
[Show abstract][Hide abstract] ABSTRACT: Dutasteride (Avodart) is a dual inhibitor of both type I and type II 5 alpha reductases, and thus inhibits conversion of testosterone to dihydrotestosterone, a key mediator of male pattern hair loss.
The aim of this randomized double-blind phase III study was to compare the efficacy, safety, and tolerability of dutasteride (0.5 mg) and placebo for 6 months of treatment in male patients with male pattern hair loss.
A total of 153 men, 18 to 49 years old, were randomized to receive 0.5 mg of dutasteride or placebo daily for 6 months. Efficacy was evaluated by the change of hair counts, subject assessment, and photographic assessment by investigators and panels.
Mean change of hair counts from baseline to 6 months after treatment start was an increase of 12.2/cm(2) in dutasteride group and 4.7/cm(2) in placebo group and this difference was statistically significant (P = .0319). Dutasteride showed significantly higher efficacy than placebo group by subject self-assessment and by investigator and panel photographic assessment. There was no major difference in adverse events between two groups.
The study was limited to 6 months.
This study clearly showed that 0.5 mg of dutasteride improved hair growth and was relatively well tolerated for the treatment of male pattern hair loss.
Full-text · Article · Aug 2010 · Journal of the American Academy of Dermatology
[Show abstract][Hide abstract] ABSTRACT: Recurrent skin infection is one of the major complications of atopic dermatitis and can be partly explained by decreased expression of antimicrobial peptides such as human beta-defensin-2 and cathelicidin (LL-37). In the human epidermis, human beta-defensin-2 is packed in the lamellar body and LL-37 is co-localized with intercellular lipid lamellae of the stratum corneum; together, these antimicrobial peptides constitute the primary defense system. IL-1alpha, a potent inducer of LL-37 and human beta-defensin-2, is also secreted from the disrupted epidermis for barrier homeostasis. In this study, we investigated whether expression of human beta-defensin-2 and LL-37 is constitutively decreased in the skin of atopic individuals. Nonlesional foreskins from atopic (n=7) and nonatopic (n=7) individuals were analyzed. The expression of LL-37, human beta-defensin-2 and IL-1alpha was analyzed using immunohistochemical staining, Western blot, and real-time polymerase chain reaction. Lamellar body density and secretion were evaluated by electron microscope. Quantitative analysis showed that the expression of each parameter was not significantly different between groups. Thus, basal expression of LL-37 and human beta-defensin-2 was not changed in atopic individuals. These results indicate that the expression of antimicrobial peptides at baseline was not different between nonlesional skin of atopic individuals and normal skin of nonatopic individuals.
No preview · Article · Jul 2010 · Pediatric Dermatology
[Show abstract][Hide abstract] ABSTRACT: Human hairs experience damage and restoration processes consistently because of various external and internal factors. To analyze degrees of hair damage, morphological studies based on electron microscopy (EM), and biochemical studies based on protein and lipid analysis have been proposed and are widely used. Among them, morphological analysis through EM is a fundamental method in understanding the degree of damage and restoration. EM has been very useful in assessing extrinsic and intrinsic damage of hair and various pathological alopecias and also in estimating the efficacy of various kinds of products related to hair care. However, morphological studies have some limitations because they have been described using varying terms and subjective descriptions by different researchers. To establish an objective classification of damaged hair using uniform terms and standardizations. We analyzed over 2000 scanning electron microscopic and transmission electron microscopic findings of normal and of various kinds of damaged hairs to develop a standard grading system for the damaged hairs. After reviewing the results of the electron microscopic pictures, we proposed a standard grading system based on scanning electron microscope and transmission electron microscope. We developed and proposed an easy, objective, and useful standard grading system of damaged hairs.
No preview · Article · Apr 2010 · The American Journal of dermatopathology
[Show abstract][Hide abstract] ABSTRACT: Membranous lipodystrophy is characterized by the presence of microcysts lined by amorphous, eosinophilic material with an arabesque appearance. We experienced a case of a 72-year-old man who had dark brownish, pruritic papules on the arms, legs, and back. Histopathologic examination of a biopsied lesion showed homogeneous, eosinophilic material in the papillary dermis, as well as membranous lipodystrophy. We report a case of membranous lipodystrophy observed in lichen amyloidosis. (Ann Dermatol 21(2) 174∼ 177, 2009).
Preview · Article · May 2009 · Annals of Dermatology