Jun-ichi Kitajima

Cell cycle analysis of human dermal fibroblasts cultured on or in hydrated type I collagen lattices

SummaryThe proliferation and cell cycle phase composition of human dermal fibroblasts cultured on or in type I collagen lattices (reconstituted dermis model) were examined. On collagen lattices, as compared with conventional cultures on plastic dishes, the proliferation of human dermal fibroblasts was suppressed, being arrested at about one-half the saturation density after 10 days of culture. In collagen lattices, proliferation was further suppressed, being nearly arrested within 4–7 days of culture. Cells were analyzed for cell cycle phases by two-color flow cytometry using DNA staining and S phase cell staining with FITC-conjugated antibromodeoxyuridine antibody. After 5 days of culture, the number of S phase cells on collagen lattices was 49.3% of that on plastic dishes, with an increase in G0G1 phase cells of 79.8%. In collagen lattices, the number of S phase cells was very small (4.3% of all cells), and most of the cells accumulated in G0G1 phase. These findings suggest that the cell cycle of fibroblasts is arrested at G0G1 phase by their interaction with collagen. On the basis of these results, the reconstituted dermis model using collagen lattice is considered to be analogous to the dermis in vivo with respect to cell growth and cell cycle phase composition.

Parallel Arrangement, Growth Inhibition and Cell Cycle Phase Analysis of Human Dermal Fibroblasts Cultured in Collagen Lattice

Human dermal fibroblasts were cultured in a hydrated type I collagen lattice. When collagen fibers were arranged in one direction, fibroblasts were arranged in the same direction. Cell proliferation was markedly suppressed in the collagen lattice as compared with that on plastic, with growth being arrested after day 5. No differences in proliferation were observed between aligned cells and randomly oriented cells.

Squamous Cell Carcinoma Developing in Epidermolysis Bullosa Dystrophica

Abstract: Two patients with epidermolysis bullosa dystrophica recessiva who had squamous cell carcinoma are presented. Case 1 is a 40–year‐old woman who had ulcers on her left lower leg. Case 2 is a 42–year‐old man who had a tumor on his left first toe. Wide surgical excision with skin coverage by autograft was performed in case 1. Amputation of the toe in case 2 was performed. A review of the cases of epidermolysis bullosa dystrophica associated with cancer reported in Japan is also presented.

Acquired Dermal Melanocytosis of the Hand: A New Clinical Type of Dermal Melanocytosis

We report a 22‐year‐old man with acquired dermal melanocytosis on the hand which developed without any history of previous inflammation. He had no history of contact with or oral administration of any drugs or metals which might have caused pigmentation. Histopathologically, spindle‐shaped dermal melanocytes were observed running parallel to the collagen bundles and scattered in all portions of the dermis. The dopa reaction of these cells was positive. Ultrastructurally, dermal melanocytes containing numerous melanosomes (stages II to IV) which were surrounded by the extracellular sheath were observed. Differential diagnosis of other dermal melanocytosis was discussed.

Primary anaplastic large-cell lymphoma of the skin: A case report suggesting that regressing atypical histiocytosis and lymphomatoid papulosis are subsets

A patient with primary anaplastic large-cell lymphoma of the skin with characteristic clinical findings is described. The diagnosis was made on the basis of histologic and immunohistochemical findings. The phenotype of the tumor cells was not determined, but rearrangement of the T-cell receptor beta gene indicated that the tumor was of T-cell lineage. Despite high-grade malignancy of the tumor cells, the patient unexpectedly had a benign clinical course. The findings in this case suggest that regressing atypical histiocytosis and lymphomatoid papulosis type A are subsets of anaplastic large-cell lymphoma.

Drug eruption caused by nitrazepam in a patient with severe pustular psoriasis successfully treated with methotrexate and etretinate.

An allergic drug eruption due to nitrazepam was reported in a patient who had been administered methotrexate and etretinate as concurrent therapies for severe pustular psoriasis. The clinical manifestation included a moon face‐like appearance with edema, a diffuse erythematous rash over almost the entire body the day after taking nitrazepam and, two days later, eroded lesions developing on the cheeks, axillae and genitocrural regions. It was proved by provocation that this drug eruption had an allergic nature.

Microsporum ferrugineum Infection with Unusual Clinical Features

Unusual skin manifestations of a dermatophyte infection in a 30‐year‐old female were reported. These included a remarkable peripheral hyperkeratosis with central yellowish pus. The pinkish papillomatous lesions were covered with thick crusts. They gave off a foul smell. Abundant fungus elements were present in the crusts and keratotic layer. The trichophytin skin test was positive. Immunologic test results revealed that the patient had hypergammaglobulinemia with hypoalbuminemia. However, she had no edema or immunologic abnormalities. The skin lesions were successfully treated with topical miconazole cream, oral griseofulvin, and topical sulconazole cream. The etiologic agent was identified as Microsporum ferrugineum Ota 1922. It seemed to us that the unusual skin manifestation were induced by her immunological response to fungal and bacterial infection due to a long history of Candida granuloma.