Michel De La Brassinne

Modulation of Dermal Cell Activity During Hair Growth in the Rat

Interaction between connective tissue cells and hair growth in the rat has been studied by radioautography after in vivo and in vitro pulse labelling with thymidine, uridine, histidine, leucine and proline. The connective tissue, which surrounds and integrates the hair bulbs as a unit, contains cells of various types which have a cyclic metabolic activity. This cyclic activity is coordinated with the hair growth cycle. The number of nuclei which actively synthesize DNA in the dermal cells, mainly those of endothelial and migratory cells, significantly increases during the short and transient anagen 4 substage. RNA and protein synthesizing activities are also present in all cell types and seem modulated by the hair cycle although to a lesser degree. This data provides an important basis for the interpretation of similar studies in alopecia areata.

Histological and transcriptional study of angiogenesis and lymphangiogenesis in uninvolved skin, acute pinpoint lesions and established psoriasis plaques: an approach of vascular development chronology in psoriasis.

BACKGROUND Dysregulation of angiogenesis and lymphangiogenesis could participate in psoriasis pathogenesis. Analysis of nascent psoriasis lesions should help at identifying early vascular anomalies. OBJECTIVE To analyse vascular development, angiogenesis and lymphangiogenesis markers expression in uninvolved skin in psoriatic patients (N), early psoriasis lesions or pinpoints (PP) and psoriasis plaques (PSO). METHODS Skin biopsies were taken in 17 patients in N and in PSO and/or PP. The mRNA steady-state level of angiogenesis and lymphangiogenesis markers was measured by RT-PCR. Immunohistochemistry was performed for von Willebrand factor, podoplanin, Ki-67 and VEGFR3. Blood (BV) and lymphatic (LV) vessels expansion was measured by computer-assisted morphometry. RESULTS Clinical and epidermal aspects indicated that PP are intermediate between N and PSO. While total BV area was already increased in PP similarly to PSO as compared to N, LV area in PP was intermediate between N and PSO. Mean LV size was identical in N and PP and increased in PSO, mean BV size in PP being intermediate between N and PSO. VEGF-A 189 variant was increased in PP as compared to N and PSO. As compared to N, angiogenesis markers (VEGF-A isoforms, PlGF, VEGFR2, NRP-1), VEGF-C and NRP-2 were similarly increased in PP and PSO. Keratin 16 and the lymphangiogenesis markers (VEGFR3, prox-1) were intermediate in PP. CONCLUSION These data suggest that the expansion of lymphatic vessels occurs after blood vascular development in psoriasis. Expansion of BV in PP could be followed by vessel enlargement during progression to PSO, in parallel with a decreased VEGF-A 189/VEGF-A 121 balance in plaques.

Cellular Activity in the Dermis Surrounding the Hair Bulb in Alopecia Areata

The metabolic activity of the cells in the connective tissue surrounding the hair bulb has been studied by radioautography in alopecia areata and in normal scalp, using in vitro incorporation of tritiated thymidine, uridine, histidine, leucine and proline. In alopecia areata, the hair bulbs are blocked in the anagen IV stage and DNA, RNA and protein synthesis are restrained. Cells in the papilla, as well as the cellular infiltrate, display a very low rate of metabolic activity. During regrowth in alopecia areata, the activity of endothelial cells is increased in the papillary and peribulbar layers before DNA, RNA and protein synthesis are restored in the epithelial cells of the hair bulb. The dermal and epithelial labelling patterns eventually reach levels comparable to those observed in an induced anagen IV stage of a normal scalp. It is concluded that the progression from anagen IV to a further stage represents a critical period in the growth of hair that would closely depend upon an adequate metabolic function of the connective tissue. It is impaired in alopecia areata.

Congenital psoriasis following the lines of Blaschko

Abstract: Congenital psoriasis without an underlying nevus following the lines of Blaschko is described In a 6‐year‐old girl. In addition to this special type of psoriasis, she suffered from atopic dermatitis. The lesions were aggravated by sun exposure and phototherapy treatments, as well as by upper airways infections, without any clear explanation of these trigger factors. We propose to call this form of psoriasis congenital blaschkoid psoriasis.

Cosmetic surgery for congenital nail deformities.

Only a few nail dystrophies may be improved by surgery: malalignment of the big toenail, racquet thumbs, trapezoidal nails, and vertical implantation of the nail on the fifth toe. Knowledge of the surgical management of these deformities may allow a nice cosmetic outcome if performed by skilled surgeons.

Cell Renewal in Discoid Lupus Erythematosus

Cell proliferation has been evaluated in four patients with discoid lupus erythematosus after in vivo incorporation of tritiated thymidine. Numerous epidermal cells are in S phase or in mitosis. The acceleration of cell renewal is paralleled by a shortening of the transit time of completely differentiating keratinocytes. Remodellings of the vascular belt are evidenced by the labeling of many endothelial cells. There is no sign of lymphoblastic transformation in the dermis since the mononuclear infiltrate remains unlabeled.

Scedosporium apiospermum septicemia following a wedge excision of an ingrown toenail.

day and progressively improved. The dose was tapered gradually. On the maintenance dose, however, the symptoms worsened. Topical tacrolimus twice daily and prednisone 1 mg/kg/day were started. After 1 year of follow-up, the patient was asymptomatic and there was no recurrence of the clinical features. Crohn’s disease is a chronic inflammatory disorder of unknown origin which may involve any segment of the gastrointestinal tract from mouth to anus, and may present extraintestinal manifestations, with cutaneous being the most frequent. These may be classified as nonspecific or specific lesions with a granulomatous noncaseating infiltrate on histologic examination. The latter can affect the skin of the involved bowel directly, or sites distant from the gastrointestinal tract, known as metastatic Crohn’s disease. Metastatic Crohn’s disease was described for the first time by Parks et al. Clinically, it presents as ulcers, papules, nodules, plaques, or crusts located most frequently on the extremities, flexures, and genitalia. It is necessary to exclude other granulomatous diseases, such as cellulitis, erysipelas, intertrigo, sexually transmitted diseases, hidradenitis suppurativa, lichenoid eruptions, erythema nodosum, primary and secondary lymphedema, hypoproteinemia, and renal, cardiac, and venous problems. Characteristic histologic findings include a noncaseating granulomatous infiltration of the dermis, similar to that of primary Crohn’s disease, often arranged in a perivascular distribution, and sometimes described as granulomatous perivasculitis. There is no specific treatment for genital involvement of Crohn’s disease. Topical and systemic steroid, azathioprine, sulfasalazine, tetracyclines, metronidazole, and dapsone have been used with success. A few cases in which circumcision was required have been reported. Although it has been reported that topical tacrolimus is effective and safe in the treatment of perianal or anal ulcerating Crohn’s disease, metastatic Crohn’s disease treated with topical tacrolimus has not been described. We present a case of Crohn’s disease involving the penis successfully treated with prednisone and topical tacrolimus.

A new generation of hydrocolloid dressings in combination with topical corticosteroids in the treatment of psoriasis vulgaris

Abstract Aim A clinical, randomized, parallel, multicenter study was undertaken to compare the efficacy and the tolerability of two known steroid creams, betamethasone 17-valerate and clobetasol propionate, alone or left under a hydrocolloid dressing (Contreet° Derma Cover), in the treatment of chronic plaques of psoriasis. Methods A total of 70 patients with symmetrical localized psoriasis were divided randomly into two groups for the study. Each patient applied the corticosteroid preparation under Contreet° Derma Cover once a week on one plaque and the same topical corticosteroid alone b.i.d on the other plaque; the treatment lasted 3 weeks for betamethasone 17-valerate, and 2 weeks for clobetasol propionate. Results The healing rate reached 79% with the Contreet° combined treatment versus 15% ( P P Conclusion The use of the new generation of hydrocolloid dressings in combination with steroid preparations can be considered as another therapeutic option for the treatment of chronic localized psoriatic lesions. Furthermore, with this method the amount of the topical corticosteroid used can be reduced.

Epidermoid carcinoma and perforating necrobiosis lipoidica: a rare association.

We report the case of a 33‐year‐old patient who had had insulin‐dependent diabetes mellitus (IDDM) since he was 11 months old, and who presented with major perforating necrobiosis lipoidica (PNL) complicated by a well‐differentiated epidermoid carcinoma. PNL is a rare clinical form of NL, always associated with diabetes. Only seven cases have been reported to date in the literature, and to the best of our knowledge, an association of epidermoid carcinoma and PNL has never been described. The development of a tumoral transformation on a classical NL plaque has only been described 12 times. The presence of an epidermoid carcinoma on a weakened background with permanent ulceration suggests that early surgical excision of the tumour and of the NL followed by a skin graft might be the treatment of choice. Radiotherapy seems to be a poor therapeutic option.

Interpretation pathogénique de l’extension des placards de psoriasis

The extension border of lesions of psoriasis vulgaris has been studied by histogeometric analysis of the epidermis and by autoradiography after in vitro incorporation of tritiated thymidine. The first modification observed is a hyperactivity of in the suprabasal layer associated DNA-synthesis with band-like acanthosis. Later, the basal labelling index is increased and the germinative compartment is exponentially enlarged by extension to more superficial layers, each of them reaching progressively the level of thymidine incorporation in the preceding one. These modifications could result from a defect of cellular differenciation perhaps through a decreased receptivity of the psoriatic epidermal cells to some inhibitory factors and a progressive selection of this population.