Yasushi Sadamoto

Co‐culture of Human Hair Follicles and Dermal Papillae in a Collagen Matrix

Human hair follicles, either alone or in combination with dermal papillae, were cultured in a collagen matrix. When plucked hair follicles were cultured alone, spike‐like structures composed of outer root sheath cells started growing around the follicle and then radiated into the gel. When isolated dermal papillae were embedded close to the follicles, spikes started growing earlier and grew more rapidly than without the papillae. In cultures of excised follicles from which the dermal papilla had been removed, epithelial cells (possibly hair bulb cells) started growing out from the bulbous portion and then also formed spikes. In the presence of a papilla, the spikes elongated toward the papilla, finally reaching and surrounding it. These findings suggest that dermal papilla cells produce a factor(s) that enhances growth of follicular epithelial cells and also attracts those cells.

Culture of human outer root sheath cells from plucked hair follicles in serum-free conditions

We succeeded in culturing human outer root sheath cells (ORSC) in serum-free conditions without a biological feeder layer. The combination of collagen type IV substrate and modified MCDB 153 medium supplemented with bovine pituitary gland extract (K-GM medium) could support the growth of ORSC. These cells can be serially cultivated for at least 4 passages and stored in liquid nitrogen with good recovery. Thus, a large series of experiments using ORSC may be run simultaneously.

Eosinophilic Polymyositis Induced by Tranilast

A 38‐year‐old man with asthma developed eosinophilic polymyositis following the administration of Tranilast, an antiasthmatic agent. Low grade fever, erythematous rashes on the entire body, dysphagia, blood eosinophilia, elevations of serum creatine phosphokinase and myoglobin levels, and inverted T waves in the electrocardiogram were noted. A muscle biopsy showed focal degeneration of muscle fibers with an infiltrate of eosinophils and lymphocytes. A rechallenge with Tranilast resulted in erythema formation, blood eosinophilia, and elevations of some serum muscle enzymes and myoglobin levels. Tranilast was considered to be the causative agent. This is the first reported case of Tranilast‐induced eosinophilic polymyositis.

The effect of 1,25-dihydroxyvitamin D3 on the growth and differentiation of cultured human outer root sheath cells from normal subjects and patients with vitamin D-dependent rickets type II with alopecia.

We examined the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the growth and differentiation of cultured human hair outer root sheath cells (ORSC) from normal subjects and patients with vitamin D-dependent rickets type II (DDR-II) with alopecia. 1,25(OH)2D3 dose-dependently suppressed the plating efficiency, clonal growth, and DNA synthesis of normal ORSC. It enhanced the cornified envelope formation and caused morphological changes in the cells. All results indicated the existence of specific receptors for 1,25(OH)2D3 in the ORSC, and suggest that 1,25(OH)2D3 is a potent inhibitor of proliferation of ORSC as well as a stimulator of terminal differentiation. However, the cells from DDR-II patients with alopecia did not respond to 1,25(OH)2D3, suggesting a lack of the specific receptors in the cells. The differences in the cellular response to the hormone between the normal ORSC and those from the patients were apparent and easily distinguishable, therefore this experiment may be a rapid and simple diagnostic test for DDR-II patients with alopecia. Large number of hairs were difficult to obtain from patients with alopecia, and we developed a new culture method to accomplish these studies from a few plucked hair follicles. Our system may be useful in the culture of ORSC from limited number of follicles, and could be utilized to analyse the cellular characteristics of ORSC in patients with hair diseases.

A New Method for Culturing Human Hair Follicle Cells on Floating Mixed Collagen Membranes

A new method for culturing human hair follicle cells without a biological feeder layer has been developed.

Generalized malignant acanthosis nigricans with "deck-chair sign".

‘‘deck-chair sign’’ The so-called ‘‘deck-chair sign’’ defines a peculiar clinical pattern observed in patients with papuloerythroderma of Ofuji (PEO), characterized by a selective sparing of major skin folds and flexures. Although the deck-chair sign was originally considered a specific feature of PEO, several case reports have suggested that the deck-chair sign is not pathognomonic for PEO but rather a clinical pattern of expression in many inflammatory dermatoses. Here we describe a case of malignant acanthosis nigricans (MAN) associated with progressive gastric adenocarcinoma. Skin eruption was generalized but spared the major skin folds in the abdomen and preaxillar regions, producing the so-called ‘‘deck-chair sign’’. To our knowledge, this is the first case report describing MAN presenting with deck-chair sign. A 68-year-old Japanese woman was referred to the Dermatology Department for evaluation of a 3-month history of generalized eruption. Physical examination demonstrated a diffuse, brownish hyperpigmentation and velvety thickening of the skin occurring all over the body, but sparing the skin folds on the abdomen and preaxillar regions (Fig. 1a). Dorsal surfaces of the hands and feet also exhibited velvety thickening of the skin and hyperkeratosis (Fig. 1b). Histological examination of a keratotic lesion on the forearm showed hyperkeratosis and papillomatosis with slight acanthosis and hyperpigmentation in the basal layer, consistent with the histological features of acanthosis nigricans (AN; Fig. 2). Laboratory investigation revealed that her carbohydrate antigen 19–9 (CA19–9) was 158 U/ml (normal < 37 U/ml), and subsequent examination of the gastrointestinal tract revealed progressive gastric adenocarcinoma (Borrmann type III, Stage IIIb). We made a diagnosis of MAN based on these findings. Two months after the initial visit to our hospital, she underwent total gastrectomy and splenectomy with regional lymph node dissection. Although her eruptions had been refractory to skin treatment, they cleared soon after surgery. Four months after surgery, her gastric cancer recurred, and she died of multiple organ failure one year after surgery. Acanthosis nigricans is a dermatosis characterized by a hyperpigmented, velvety cutaneous thickening, typically distributed in intertriginous areas. AN is known to be associated with internal malignancies, especially gastric adenocarcinoma and, in that case, it is called MAN. 377 (a)