Library

Notes: Korea is located between Japan and Mainland China. The people of these three countries have similar appearances and it is difficult to differentiate between them. Although the population of Asia is more than half of the total population of the Earth, the inherent characteristics of Asian skin have not been well investigated. Commercial markets for cosmetics and drugs for photoaged skin are rapidly expanding in many Asian countries. Therefore, many investigators in the field of dermatology and cosmetology have become interested in brown Asian skin.〈section xml:id="abs1-2"〉〈title type="main"〉Clinical characteristics of skin aging and photoaging in AsiansSkin aging can be divided into two basic processes: intrinsic aging and photoaging [1]. Intrinsic aging is characterized by smooth, dry, pale, and finely wrinkled skin, whereas photoaging, which indicates premature skin aging in chronically photodamaged skin, is characterized by severe wrinkling and irregular pigmentation. The pattern of wrinkling in Asians seems to differ from that in Caucasians. Asians have coarser, thicker and deep wrinkles, particularly in the forehead, perioral and Crow's foot areas. In contrast, Caucasians usually have relatively fine cheek and Crow's foot wrinkles. The reasons for these differences are not known and need further investigation.There are racial, ethnic and genetic differences, and differences of skin structure and function, between the brown skin of Asians and the white skin of Caucasians. As Asian skin is more pigmented, acute and chronic cutaneous responses to UV irradiation differ from those in white skin. Many people believe, based on clinical impressions, that the main process of photoaging in Asians involves pigmentary changes, rather than wrinkling. However, no study has been performed to confirm this belief.〈section xml:id="abs1-3"〉〈title type="main"〉Risk factors for skin wrinkles and their relative risks in Korean skin [2]Various factors such as age, sun-exposure, and smoking are known to be important risk factors for wrinkles. However, the relative risks of each factor on wrinkles in the brown skin of Asians have not been investigated, and they could differ from those in Caucasians.An evaluation system for skin wrinkling is necessary for Asian skin [3]. Thus, we developed an eight-point photographic scale for assessing wrinkles in both Korean genders [2]. This scale can probably be applied to the populations of other Asian countries, at least to the Japanese and Chinese. The pattern of wrinkles in both genders appears to be similar.〈section xml:id="abs1-4"〉〈title type="main"〉AgeAge is an important risk factor for wrinkling in Asians, as in Caucasians. Korean subjects in their 60s showed a 12-fold increased risk of wrinkling, while subjects in their 70s have a 56-fold increased risk compared with young age group.〈section xml:id="abs1-5"〉〈title type="main"〉UV lightIt is well known that the UV component in sunlight can cause and accelerate photoaging. The pigmented skin of Asian may better protect skin from acute and chronic UV damage. However, we found a strong association between sun-exposure and the development of wrinkling in Koreans. It was found that sun exposure of more than 5 h per day was associated with a 4.8-fold increased risk in wrinkling versus less than 2 h of sun-exposure in Koreans.〈section xml:id="abs1-6"〉〈title type="main"〉Estrogen deficiencyKorean females have more wrinkles than men, after controlling for age, sun exposure, and smoking, it was found that they have a 3.6-fold increased risk of developing wrinkles than their male counterparts [2]. It has also been reported, that the relative risk for wrinkling in women is higher than in men as for in white Caucasians [4]. The reason why women show more wrinkles remains to be determined. It is possible that a reduction in skin collagen because of estrogen deficiency in postmenopausal woman may aggravate wrinkling severity. Korean women with more than 10 years since menopause showed a 3.9-fold higher risk of wrinkling than the women 5 years of beyond menopause [5]. We demonstrated that women with a history of HRT have a significantly lower risk, more specifically, one fifth of the risk of facial wrinkling relative to those who had no history of HRT. Interestingly, we found that wrinkle severity significantly increased with an increasing number of full term pregnancies. The relative risk for severe wrinkling is increased by approximately 1.8-fold per full term pregnancy.〈section xml:id="abs1-7"〉〈title type="main"〉SmokingIt is known that smoking causes skin wrinkling in Caucasians, and that it plays no role in Blacks [6, 7]. Koreans with have a smoking history of more than 30 pack years showed a more than 2.8-fold increased risk of wrinkles [2]. The relative risks of wrinkles associated with a 30–50 pack-years history of smoking were 2.8- and 5.5-fold, respectively.〈section xml:id="abs1-8"〉〈title type="main"〉Dyspigmentation in Asian skinTo follow pigmentary changes, six photographic standards for both genders were developed for Korean skin, to produce a 6-point scale [2, 8]. Hyperpigmented spots, mostly lentigines, were prominent among women, while seborrheic keratosis tended to be more prominent in men.〈section xml:id="abs1-9"〉〈title type="main"〉Seborrheic keratosis in Korean menSeborrheic keratoses (SKs) are benign cutaneous tumors. They have diverse clinical and histopathological appearances and are very common in the elderly (over 50 years old). The etiology of SKs is not well understood, although patients with a great number of lesionsshow a familial trait with an autosomal dominant pattern, and human papilloma virus has been suggested as possible cause because of verrucous appearance of the lesions. Exposure to sunlight has been suggested to be a risk factor for SKs. However, there is still some debate in terms of the role of sunlight. Recently, we have investigated the clinical characteristics of SKs and relationship between SKs and sunlight exposure in Korean males [9].The prevalence of SKs in Koreans increases with age; it rose from 78.9% at 40 years, to 93.9% at 50 years and 98.7% in those over 60 years. Exposed areas, i.e. the face, neck and dorsum of the hands, demonstrate a significant increase in the prevalence of SKs by decade, whereas partly exposed areas, although SKs tended to increase in prevalence with age, this trend was not significant. When the estimated body surface area (BSA) is taken into account, the number of SKs on both the face and dorsum of the hands (0.51 ± 0.08 per 1% BSA) was over-represented compared with the trunk. SKs were also concentrated on the neck (0.38 ± 0.07 per 1% BSA) and in the V-area (0.47 ± 0.09 per 1% BSA). Outer forearms also showed 3-fold more SKs per unit area than neighboring arms and inner forearms, which are classified as partly exposed area (0.09 ± 0.02, 0.03 ± 0.01, respectively). The total area covered by SKs on exposed area also became significantly larger with aging than on intermittently exposed areas. These results indicate that exposure to sunlight might be related to SK growth.Our results indicated that excessive sun exposure is an independent risk factor of SKs. After controlling for age, smoking, and skin type, subjects with a sun exposure history of more than 6 hours per day showed a 2.28-fold increased risk of having severe SKs (n ≥ 6) compared with those exposed for less that 3 h per day. These findings indicated that sun-exposure may play an important role in SK development.In summary, SKs are very common in Korean males and represent one of the major pigmentary problems. SKs concentrate on exposed skin, especially on the face and dorsum of the hands. Both age and lifetime cumulative sunlight exposure are important contributing factors and may work in a synergistic manner.〈section xml:id="abs1-10"〉〈title type="main"〉ConclusionMany people tend to believe that wrinkles are not a prominent feature of Asian photoaged skin, and

Notes: Background  There are many reports of patients with a severe hydroa vacciniforme (HV)-like eruption in which cutaneous lesions occur in both sun-exposed and non-exposed areas, unlike in true HV. Several patients have died from a malignant haematological neoplasm. In most cases, a latent Epstein–Barr virus (EBV) infection has been detected in the skin lesions.Objectives  To describe the clinical and laboratory features of six additional patients with an EBV-associated HV-like eruption.Methods  The clinical, histological and immunohistochemical features were reviewed. T-cell receptor γ gene rearrangements were studied using polymerase chain reaction (PCR) and heteroduplex analysis. In-situ hybridization was performed to detect mRNA for EBV in skin biopsy specimens. PCR was performed to screen for EBV infection in the skin lesions of three patients and blood of two patients. Photoprovocation with repeated ultraviolet (UV) A exposure was performed in three patients.Results  The severity of the skin lesions and the clinical course varied among the patients. Skin lesions were induced by repeated UVA exposure in three patients and a latent EBV infection was demonstrated in the photoprovoked lesions.Conclusions  Three different clinical courses were found in six patients with an HV-like eruption associated with chronic EBV infection: (i) spontaneous remission; (ii) clearing after photoprotection; and (iii) continuous recurrence irrespective of sun exposure. It is possible that there are two patterns of HV-like eruption associated with chronic EBV infection. One is characterized by recurrent necrotic papulovesicles of the face and the other by nodules and facial swelling. It was demonstrated that the skin lesions could be triggered by repeated UVA exposure in the patients showing recurrent necrotic papulovesicles of the face.

Notes: Abstract The heat shock response is a highly conserved reaction common to all cells and organisms. It has been reported that hyperthermic treatment can induce the expression of the heat shock protein (HSP) and can protect cells from ultraviolet (UV) B radiation. In this study, we evaluated the effects of induced HSP70 on resistance to UV radiation. G361 amelanotic human melanoma cells were irradiated with increasing doses of UVB. UVB irradiation caused apoptotic cell death in these cells. Following transfection with MFG.hsp70.puro plasmid, the expression of HSP70 was determined. Compared to control vector-transfected cells, hsp70-transfected cells showed significantly elevated levels of HSP70 and were highly resistant to UVB irradiation. In order to investigate the effects of HSP70 on the apoptotic pathway, the changes in caspase-3 and PARP were analyzed. Following UVB irradiation, activation of caspase-3 and cleavage of PARP were observed in control vector-transfected cells, and the changes in these molecules were inhibited in the hsp70-transfected cells. These results suggest that UVB-induced apoptosis of melanoma cells is accompanied by caspase-3 activation and PARP cleavage, which can be prevented by an overexpression of HSP70.

Notes: Abstract Single non-lethal doses (3 mmol/kg) of chloroform (CHCl3), dichlorobromomethane (CHCl2Br), dibromochloromethane (CHClBr2), and bromoform (CHBr3) were administered by intraperitoneal injection to male Sprague-Dawley rats and proximal tubular secretion and reabsorption was assessed at varied times following treatment. Each of the trihalomethanes (THMs) at this dose inhibited proximal tubular secretion, as indicated by decreased in vitro renal cortical slice accumulation of organic anion p-aminohippuric acid (14C PAH). The time of maximal THM interference with 14C PAH uptake occurred at 8 h, with recovery being demonstrated by 48 h. Each of the THMs also demonstrated interference with tubular reabsorption, as assessed by urinary glucose excretion, with maximal interference occurring during the first day post-treatment and recovery being observed during the second day post-treatment. In each case, CHCl2Br was the most potent inhibitor of proximal tubular function. Combining these data with those of the preceding paper, the relative potency in disrupting renal function was, in general, CHCl2Br〉CHCl3〉CHClBr2〉CHBr3. Since the time course of this investigation indicates that proximal tubular dysfunction precedes other THM-induced renal function interferences, it also appears that proximal tubular damage is the primary event leading to further manifestations of renal dysfunction.

Notes: Abstract To develop a model for the study of oral epithelial differentiation, we reconstructed artificial buccal mucosa equivalents using keratinocytes and fibroblasts or de-epidermized dermis derived from noncornifying buccal mucosa. The buccal mucosa equivalents reconstructed in this way showed a morphology closely mimicking that of their in vivo counterparts. There was no formation of horny layers and granular layers. The expression of various differentiation markers such as K13, involucrin and loricrin was consistent with that of the in vivo state, and indicative of the hyperproliferative state. We also demonstrated that the differentiation of oral epithelial cells was influenced by the de-epidermized dermis and subepithelial fibroblasts. The epidermis of buccal mucosa equivalents seemed to be less sensitive to retinoic acid than that of the skin. The effects of calcipotriol on the buccal mucosa equivalent and the skin epidermis were different. These results suggest that the pharmacological effects of retinoic acid and calcipotriol on the buccal mucosa are different from those on the skin. A useful model system for studies of oral keratinocyte differentiation and pharmacological research could be based on these artificial buccal mucosa equivalents.

Notes: Abstract Single non-lethal doses (3 mmol/kg) of chloroform (CHCl3), dichlorobromomethane (CHCl2Br), dibromochloromethane (CHClBr2), and bromoform (CHBr3) were administered by intraperitoneal injection to male Sprague-Dawley rats and glomerular filtration and renal concentrating ability were assessed at varied times (5–8 h, 21–24 h, and 45–58 h) following treatment. At this dose, each of the four trihalomethanes (THMs) elevated blood urea nitrogen (BUN) and reduced renal concentrating ability (as measured by H2O intake/output ratios, urinary total osmolality, and electrolyte levels). Three of the four THMs also significantly reduced glomerular filtration rate (GFR), with only CHCl3 failing to demonstrate an effect at 3 mmol/kg. In general, CHCl2Br demonstrated the greatest interference with these renal function parameters. The times of maximal THM-induced effect on BUN and glomerular filtration rate were observed to be 24 h and 21–24 h post-treatment, respectively. These data suggest that a single acute THM treatment can inhibit mammalian renal concentrating ability and glomerular filtration.

Notes: Abstract Anti-double stranded(ds) DNA antibody is one of markers of systemic lupus erythematosus (SLE). Two human monoclonal anti-DNA antibody – producing cell lines were established from two SLE patients. One cell line secreted IgG isotype antibody (KSUG) and the other secreted IgM isotype antibody (KSUN). The light chains of the two immunoglobulins were lambda chains. The nucleotide sequences for the immunoglobulin variable region genes of the two antibodies were determined and compared to germline sequences. The heavy and lambda light chains of KSUG were VH3 family and V λ IIIb, respectively. The heavy and lambda light chains of KSUN were VH4 family and V λ IX, respectively. Antibody KSUG, IgG isotype, showed somatic mutations, whereas KSUN, IgM isotype, used the germline gene without mutation. These findings reconfirm the current paradigms that IgM anti-DNA antibodies are produced by utilizing germline genes whereas IgG anti-DNA antibodies are produced by somatic mutations.

Notes: Abstract  · Background: The effect of 0.1% dexamethasone on epithelial healing was evaluated in corneal alkali wounds. · Methods: Epithelial wounds were induced by a 60-s application of a round filter paper (5.5 mm) soaked in 1 N NaOH onto the central cornea of the rabbit. Animals were treated with 0.1% dexamethasone 4 times each day for 8 weeks in one subgroup and only for the 1st week in the other subgroup. The control eyes were treated with a balanced salt solution. The repair processes of epithelium and its basement membrane were evaluated morphologically and morphometrically. · Results: Treatment with 0.1% dexamethasone was found to retard the repair process of epithelial healing compared with the control eyes. Morphologically, the basement membrane in the control cornea was damaged focally at 2 days, maximally disrupted at 4 weeks, and regained the normal integrity at 8 weeks after the initial alkali damage. In 0.1% dexamethasone-treated corneas, regardless of the application period, the basement membrane structure was visible up to 4 weeks but disappeared at 8 weeks after the initial alkali wounds. The eyes treated with 0.1% dexamethasone for 8 weeks showed an intense infiltration of inflammatory cells in the superficial stroma 4 weeks after treatment. · Conclusion: A topical application of 0.1% dexamethasone retarded the corneal epithelial healing. The cornea treated with 0.1% dexamethasone only for the 1st week maintained a well-preserved basement membrane for as long as 4 weeks after initial damage without enhancement of the inflammatory cell infiltration. However, further study is needed to prevent late disintegration of the basement membrane.