Comparison of Gene Expression Profiles between Keratinocytes, Melanocytes and Fibroblasts

BACKGROUND: The skin has many important functions such as protection, preservation, temperature regulation, and vitamin D synthesis. It is composed of a variety of cell types including keratinocytes, melanocytes and fibroblasts. OBJECTIVE: We attempted to compare the gene expression profiles between keratinocytes, melanocytes and fibroblast, using cDNA microarray. METHODS: Keratinocytes, melanocytes and fibroblasts were primary cultured from five foreskin specimens. Total RNAs were extracted and pooled to reduce the individual variations, and then used for cDNA microarray. RESULTS: Total 12,028 genes were selected as the reliable genes whose expression was detected in at least one of the three cell types. By comparing the relative expression levels with cutoff limitation as a fourfold change, we obtained 126 fibroblast-specific, 179 keratinocyte-specific and 173 melanocyte-specific genes, many of which are known to be characteristically expressed in each cell type. In addition, we identified many genes whose skin-specific functions have not yet been determined. CONCLUSION: Our data provide important information on which to base further investigation into the specification of skin cell types.

Two Cases of Linear Focal Elastosis

We report two cases of linear focal elastosis. They are a 16-year-old girl and a 14-year-old boy who had had asymptomatic, several, yellow-red, slightly elevated, palpable, striae-like lesions on their middle and lower back since their early childhood. Light microscopic examinations of skin biopsy specimens demonstrated dermal thickening and focal increases of thin wavy fibers in the upper and mid-dermis but no changes in the epidermis. Verhoeff-van Gieson stains for elastic fiber revealed aggregated, clumped, curled, or fragmented elastic fibers.

Clinical and Histopathological Study of Cellulitis / 대한피부과학회지

BACKGROUND: Cellulitis is a suppurative inflammation involving particularly the subcutaneous tissue. There has been no data about its clinicopathologic features in Korea. OBJECTIVES: The purpose of this study was to investigate the clinicopathologic characteristics of cellulitis and to assess the yield rate of special stainings (Brown-Brenn, Gram) for organisms. METHODS: We reviewed the medical records and histologic sections of 45 patients who had been diagnosed as cellulitis in the Department of Dermatology, Chungbuk National University Hospital from January 1992 to August 1998. RESULTS: The results were as follows. 1. The sex ratio of male to female was 1.5:1 and average age was 43 years old. 2. The lower extremity was the most frequently involved site of cellulitis with a frequency of 53.4%. 3. Erythema, tenderness, local heating, swelling, and pain were almost always presenting clinical manifestations. 4. Diabetes mellitus was the most frequent underlying systemic disease. 5. The route of infection was suspected in 25 cases(55.6%). Tinea pedis was strongly suspected in 7 cases(28.0%), and followed by insect bite in 5 cases(20.0%), herpes zoster in 4 cases(16.0%), and trauma in 2 cases(8.0%). 6. The main complications were orthopedic problems including bursitis, osteomyelitis, and septic arthritis. 7. Microorganisms were isolated in 20 of 43 tissue cultures(46.5%). 8. It is important to suspect Escherichia coli as a causative organism if blistering cellulitis occurs, especially in patients with underlying systemic disease. 9. The most frequent histopathologic findings were perivascular lymphohistiocytic infiltrations in both dermis and subcutaneous fat simultaneously without vasculitis. 10. Special stainings(Brown-Brenn or Gram) were worthy to try, especially in the neutrophilic dominant cellulitis. 11. First-generation cephalosporin was chosen as primary antibiotics in 31 cases, and there was no difference in clinical course between its monotherapy and combined therapy. 12. Twenty percent of cases experienced recurrences. Lower extremity was most common site of recurrence(63.6%). CONCLUSION: Diabetes mellitus and tinea pedis were so closely bound up with cellulitis that control of those diseases is important in view of the clinical course of cellulitis. Special stainings(Brown-Brenn or Gram) were worthy to try, especially in the neutrophilic dominant cellulitis.

A Case of Trichilemmal Carcinoma

Trichilemmal carcinoma is a rare tumor that is located predominantly on sun-exposed skin of the elderly. It is thought to be related to the external root sheath of the hair follicle and the malignant counterpart of a trichilemmoma. We report a case of trichilemmal carcinoma in a 88-year-old woman who had a 10 year history of a single, dark brown tumor on the right preauricular region. In her past medical history, it had been excised twice at a private clinic without a histopathological evaluation and recurred 2 years later. Histopathological findings showed atypical clear cells resembling those of the outer root sheath. Tumor cells showed PAS-positive cytoplasm. Immunohistochemistry revealed positive high molecular weight cytokeratin expression. To our knowledge, this is the second case of trichilemmal carcinoma in the Korean literature. (Ann Dermatol 100) 175178, 1998).