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Biomedical subjects

S E Moon

Publications and source records attributed to S E Moon.

13 recordsLinked to original sources

Keratinocyte stimulation of matrix metalloproteinase-1 production and proliferation in fibroblasts: regulation through mitogen-activated protein kinase signalling events.

Incubation of human dermal fibroblasts in keratinocyte-conditioned culture medium led to a 5.7-fold increase in the level of matrix metalloproteinase-1. Virtually all of the matrix metalloproteinase-1 - inducing activity could be related to agonists acting through members of the epidermal growth factor receptor family or to agonists acting through the interleukin-1 receptor. The same keratinocyte-conditioned medium also induced a modest increase in fibroblast proliferation (approximately 1.8-fold). Growth-stimulating activity could be attributed to epidermal growth factor receptor (but not interleukin-1 receptor) function. In fibroblasts exposed to keratinocyte-conditioned medium, mitogen-activated protein kinase signalling through both the extracellular signal-related kinase pathway and p38 pathway occurred. When recombinant epidermal growth factor or recombinant interleukin-1beta were used as a control, they induced mitogen-activated protein kinase signalling consistent with the combined effects of epidermal growth factor receptor - specific and interleukin-1 receptor - specific agonists in keratinocyte-conditioned medium. Recombinant epidermal growth factor stimulated both matrix metalloproteinase-1 induction and proliferation while recombinant interleukin-1beta stimulated matrix metalloproteinase-1 elaboration but not fibroblast growth. An inhibitor of extracellular signal-related kinase pathway signalling (U0126) blocked induction of matrix metalloproteinase-1 production induced by keratinocyte-conditioned medium (as well as by epidermal growth factor or interleukin-1beta), and also inhibited proliferation. A p38 signalling inhibitor (SB203580) blocked matrix metalloproteinase-1 elaboration induced by keratinocyte-conditioned medium or interleukin-1beta, but did not inhibit matrix metalloproteinase-1 elaboration or cell growth induced by epidermal growth factor. These data indicate that keratinocyte-fibroblast interactions are mediated by multiple stimulating agents acting on specific receptors to induce signalling through different mitogen-activated protein kinase pathways leading to altered expression of key biological functions.

Carrier Proteins↗

Induction of matrix metalloproteinase-1 (MMP-1) during epidermal invasion of the stroma in human skin organ culture: keratinocyte stimulation of fibroblast MMP-1 production.

Organ cultures of human skin were incubated for 8 days under growth factor-free conditions or exposed to 10 ng ml(-1) of human recombinant epidermal growth factor (EGF) during the incubation period. Normal histological features were preserved in the absence of growth factor, while epithelial cells underwent a proliferative response and invaded the underlying stroma in the presence of exogenous EGF. The same concentrations of EGF that induced stromal invasion also resulted in up-regulation of matrix metalloproteinase-9 (MMP-9; 92-kD gelatinase B) in organ culture and keratinocyte monolayer culture, and expression of MMP-1 (interstitial collagenase) in organ culture and fibroblast monolayer culture. When skin organ cultures were exposed to a potent, irreversible EGF-receptor tyrosine kinase (EGF-RTK) antagonist along with EGF, abnormal histological features were reversed, and MMP-9 production was suppressed. In contrast, EGF-RKT antagonism had only a modest inhibitory effect on MMP-1 production. Culture fluid from keratinocytes grown in monolayer culture stimulated fibroblast proliferation and MMP-1 elaboration. Treatment of fibroblasts with the same EGF-RTK antagonist inhibited keratinocyte-induced fibroblast proliferation but had only a modest inhibitory effect (approximately 20% inhibition) on MMP-1 production. In contrast, treatment of dermal fibroblasts with Interleukin-1 Receptor Antagonist had no effect on keratinocyte-induced fibroblast growth but strongly inhibited MMP-1 production (greater than 70% inhibition). These data indicate that stromal invasion by epithelial cells in EGF-treated skin is associated with events occurring in both the epidermis and dermis. The direct effect of the exogenous growth factor appears to be primarily on the epidermis. Dermal events reflect, at least in part, a response to factors elaborated in the epidermis.

Cell Differentiation↗

Oral health attitudes/behavior and gingival self-care level of Korean dental hygiene students.

The purpose of this study was to examine oral health attitudes/behavior and gingival self-care levels of Korean dental hygiene students (n = 271). A questionnaire known as HU-DBI (Korean version) was administered to each class. Higher scores of the HU-DBI indicate better oral health attitudes/behavior. The student's gingival self-care level was scored as excellent (+2), good (+1), questionable (0), poor (-1), or very poor (-2) according to the criteria of the Oral Rating Index (ORI) for youth. The mean score of the HU-DBI was 6.40, and that of the ORI was +0.12. Most samples scored 0 or +1. The mean HU-DBI scores of year-2 and year-3 students (7.06, and 7.61 respectively) were significantly greater than that of year-1 students (5.23) (P<0.001). Twenty-three percent of the students reported a belief that they may eventually require false teeth. Half stated that they put off going to the dentist until they had toothache. Year-1 students were more likely to have this attitude compared to year-3 students. HU-DBI scores were significantly associated with ORI scores (r = 0.315; P<0.001). The differences in the HU-DBI and ORI scores across the level of education were highly significant.

Attitude to Health↗

The effect of ultraviolet-B exposure scheduling on the photodamage of hairless mouse skin.

In a mouse model, we investigated whether different exposure protocol of ultraviolet-B with the same total doses could induce a different degree of photodamage in mouse skin. Two different exposure frequencies, three times or six times a week, were applied under the condition of weekly same cumulative irradiation dose equally for 10 weeks. Then the photodamage parameters such as skin wrinkling, histochemical dermal change and epidermal and dermal thickness were evaluated. Wrinkle grade, histological assessment by score, and dermal thickness did not reveal any difference between the two groups. However, at irradiation week 10 epidermal thickness of the three times a week irradiation group was significantly thicker than that of the six times a week irradiation group. The same cumulative dose resulted in different epidermal thickness. Our results suggested that exposure frequency or scheduling could influence the epidermal damage by ultraviolet radiation even though the cumulative dose is equal.

Animals↗

The effect of glycolic acid on photoaged albino hairless mouse skin.

BACKGROUND: Several clinical reports have suggested that alpha hydroxy acids (AHAs), including glycolic acid, may improve photoaging. However, the mechanism of action of glycolic acid is not well understood. OBJECTIVE: In order to investigate the mechanism of action of glycolic acid in improving photoaged skin, we observed the effect of glycolic acid on collagen metabolism and wrinkle effacement in chronically ultraviolet B (UVB) irradiated mice. METHODS: Skh:HR-1 mice were exposed to UVB for 10 weeks and then treated topically with 15% glycolic acid for 10 weeks. We assessed the improvement in wrinkling, the depth of the dermal repair zone, and the extent of the increase in collagen synthesis. RESULTS: At treatment week 10, the glycolic acid-treated mice showed a significant decrease in wrinkle score, an increased thickness of the dermal repair zone, and an increase in the amount of collagen synthesized compared to vehicle (hydrophilic ointment base) treated mice. CONCLUSION: Topically applied glycolic acid may improve photoaging through modulation of collagen production.

Animals↗

Glycolic acid versus Jessner's solution: which is better for facial acne patients? A randomized prospective clinical trial of split-face model therapy.

BACKGROUND: Many clinicians perform glycolic acid peels for facial acne patients, but there has not been a well-controlled study to compare this new therapy with other conventional modalities. OBJECTIVE: To compare the effectiveness of treatment and side effects in the treatment of facial acne by two agents, 70% glycolic acid and Jessner's solution. METHODS: Twenty-six patients with facial acne were treated simultaneously with 70% glycolic acid and Jessner's solution biweekly on each side of the face. The treatment sides were randomized and the evaluation of treatment was done biweekly by a blinded evaluator who did not know the randomization code. Dr. Cunliffe's acne grading system was used for objective comparison. All patients were also asked about the improvement of facial acne and about the side effects experienced. Finally, the patients answered the preference test between the 2 peeling methods. RESULTS: Acne grading of both treatments improved after 3 treatment sessions. However, there were no significant differences in treatment effects between the 2 methods. As far as side effects were concerned, sites treated with Jessner's solution showed a significantly increased degree of exfoliation compared to glycolic acid (p < 0.01). CONCLUSION: Glycolic acid is less widely used than Jessner's solution due to its inconvenient application technique. But considering the equal treatment effect and lesser degree of exfoliation in glycolic acid, we would recommend the use of glycolic acid over Jessner's solution for acne patients.

Acne Vulgaris↗

A case of subungual osteochondroma.

Subungual osteochondroma is a rare form of benign bone tumor characterized by distinctive histopathological and radiological findings. The major clinical manifestation is a firm mass with tenderness. It must be differentiated from other similar diseases such as subungual exostosis, glomus tumor, and enchondroma to determine the proper surgical procedure. A 13-year-old boy had a history of a growing tender mass on the right third toe which recurred after simple excision. He was treated by careful dissection and total excision under local anesthesia. Histologic findings included a trabecular bone formation covered with hyaline cartilage cap and were compatible with osteochondroma.

Adolescent↗

Disseminated superficial porokeratosis in a patient with chronic liver disease.

A 55-year-old male suffering from liver cirrhosis presented with diffuse annular hyperkeratotic papules of abrupt onset on the trunk and extremities. Histopathologic examination revealed cornoid lamella and eosinophilic spongiosis. He did not receive any medications other than cephalosporin for spontaneous bacterial peritonitis. A review of the literature revealed that three cases developed porokeratosis when their liver function declined and that, in one case, the porokeratosis disappeared spontaneously with liver transplantation. Although the precise mechanism is unclear, there is evidence demonstrating immunoincompetence in cirrhosis. Even though we did not perform immunologic studies or exclude the possibility of drug-induced porokeratosis in our case, it is conceivable that porokeratosis can be triggered by immunosuppression due to liver cirrhosis per se.

Humans↗

Bilateral accessory tragi on the suprasternal region.

We report a 25-year-old man who had two protruding firm masses on his suprasternal region. These lesions were present at birth without any family history. He had no other subjective symptoms. In a histological specimen, there were numerous unevenly distributed telogen follicles that contained vellus hairs. Beneath a relatively narrow zone of fibrovascular tissue, lobules of fat with a central core of cartilage were seen. The mass was totally excised; during the follow-up period, there was no evidence of recurrence. The tragus derives from the first branchial arch. The accessory tragus can be found along the entire course of embryonic migration. It is usually located unilaterally in the preauricular region. To our knowledge, bilateral development on the suprasternal region has not been previously reported.

Adult↗

Acquired cutaneous lymphangiectasia.

We report a case of acquired cutaneous lymphangiectasia associated with underlying malignancy, and following an arthrotomy. Clinical and histological features were identical with those of acquired lymphangioma. Lymphangiography showed signs of acquired lymphatic obstruction. Both the underlying tumour and the arthrotomy were thought to be contributory factors.

Adult↗