Biomedical subjects
Publications and source records attributed to Y Mérot.
A 22-month-old boy had xanthomatous skin lesions, neurofibromatosis, and chronic granulocytic leukemia. Histologic examination of the xanthomatous skin lesions disclosed juvenile xanthogranulomas. Twenty-three previously published cases of this association are reviewed.
Close relationships between Merkel cells (MC) and nerve endings (NE) exist in the adult mouse. Because MC may serve as targets for the ingrowth of NE during embryogenesis, the purpose of the present study was to analyze the relationship between MC and NE during embryogenesis. Frozen tissue from whisker pads and backs of NMRI mouse embryos (12-17 d gestational age) were studied by double-labeling indirect immunofluorescence (IIF) with a cytokeratin monoclonal antibody that recognizes MC and with a neurofilament anti-serum. Such an approach allowed the analysis of a large number of MC (up to 5000), thus yielding quantitative data. At day 12 of gestational age, no MC were observed by IIF. From day 13 to 17, the number of MC, as well as their association with NE, progressively increased. On day 13, only 57% of whisker pad MC were NE associated, whereas by day 17, 95% were NE associated. These results were confirmed by electron microscopic (EM) observations. On the back, the same chronologic relationship between MC and NE was observed, but was later in the course of embryogenesis. There was also a time- and zone-dependent increase in MC association with NE in the epidermal zones studied (isthmic, parafollicular, interfollicular). These observations 1) establish the time course of MC and NE contacts during embryogenesis in the mouse epidermis, 2) show that MC are present in the epidermis and appendages before NE reach the epithelium, and 3) support the hypothesis that MC could act as targets for the growing NE.
Two patients are reported with cutaneous malignant melanoma who had been on treatment with cyclosporin A. The first case was a 44-year-old man with systemic sclerosis and the second a 52-year-old woman who had a renal transplant. In both cases cyclosporin A was administered with a low dose of prednisone.
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The clinical and histological description of 2 cases of tufted angioma is presented.
The Spitz nevus (large spindle and/or epithelioid cell nevus) is a benign acquired melanocytic tumour found predominantly in children and adolescents. Depending on the architecture (junctional, compound, dermal) and cytology (predominance of spindle or epithelioid cells, or presence of both cell types) several variants have been distinguished. A histological feature occasionally leading to diagnostic difficulties is the involvement of the suprabasal epidermis. The present study details the occurrence of intraepidermal involvement (pagetoid spread, nesting of cells, trans-epidermal elimination) according to the age of the patients. 89 cases of Spitz nevus were reviewed. There were 19 compound Spitz nevi with evidence of epidermal involvement, 56 cases of compound Spitz nevi without evidence of epidermal involvement and 14 cases of dermal Spitz nevi. The epidermal involvement mainly consisted of nesting of nevus cells above the basal cell layer, 9 cases clearly showing evidence of transepidermal elimination of cell nests. Upward spread of single melanocytes (pagetoid spread) was minimal and always associated with nesting or trans-epidermal elimination. The mean age of patients was significantly lower in the group of compound nevi with intraepidermal involvement (7.16 +/- 4.52 years), than in the group of compound nevi without epidermal involvement (13.18 +/- 8.88 years). The age of the latter group was significantly lower than the group of pure intradermal nevi (30.14 +/- 11.25 years). Thus, involvement of the suprabasal epidermis is not a feature of Spitz nevi in adults; in such a case the diagnosis of malignant melanoma should be considered.
A panel of polyclonal antisera and monoclonal antibodies (MoAb) raised against recombinant human interleukin 1 alpha (rh IL-1 alpha) and beta (rh IL-1 beta) was used to localize IL-1 pools within epidermal compartments and to characterize the immunoreactive species. Interleukin 1 alpha and beta immunoreactive species were detected by Western blot analysis only when epidermal extracts were obtained in extraction buffers containing dithiothreitol (DTT), sodium dodecyl sulfate (SDS), or 2 mercaptoethanol. Together with the 31-kD (intracellular precursor molecule) and the 17-kD (mature, secreted form) species, most of the antisera and MoAb reacted with a protein of 52-kD that was not found in several internal organs, and from which a 31-kD form could be released upon reelectrophoresis. Interleukin 1 beta immunoreactivity was consistently found by immunohistology at the level of the stratum granulosum, where IL-1 alpha immunoreactivity, although less consistently, also localized. Several monoclonal antibodies to IL-1 beta reacted intensively and specifically with epidermal basal cells. At the electron microscopical level, IL-1 beta immunoreactivity was detected in the upper layers of the stratum granulosum; it appeared to be membrane associated and suggested an exocytosis process similar to that involving lamellar bodies. These observations 1) confirm the presence of IL-1 species in the normal unstimulated human epidermis, 2) show that both IL-1 alpha and beta are detectable herein, 3) identify 52-kD IL-1 alpha and beta immunoreactive bands that appear special to the epidermis, and 4) suggest a link between epidermal IL-1 and the differentiation process of the keratinocyte.
We report an additional case of melanocanthoma, a rare benign mixed tumor of both keratinocytes and melanocytes occurring in a 66-year-old man on the penis shaft, a localization not previously described. Clinical and histological features are briefly discussed.
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A randomized double-blind study was designed with 65 patients in order to clarify two points: (1) does addition of a retinoid to psoralen-ultra violet A photochemotherapy (PUVA) of severe psoriasis decrease the UVA energy required to achieve remission, and (2) is there a difference between two retinoids, i.e. etretinate and acitretin. Acitretin-PUVA treatment was significantly superior to placebo-PUVA with respect to several items (decrease in lesional scores after 6 weeks of therapy, number of PUVA exposures, and total dose of UVA until remission). There were also differences between the etretinate-PUVA and placebo-PUVA groups, but only the decrease in lesional scores reached statistical significance.
Ro 13-7410 was given to 29 patients (a total of 38 treatment courses) for 7.5 weeks (range 4-23). This compound is one of the most potent retinoids ever synthetized and has the highest affinity to human skin cellular retinoic-acid-binding protein. At therapeutically active doses, it did not induce the commonly seen mucocutaneous signs of retinoid toxicity such as scaling and cheilitis; over 0.5 microgram/kg body weight/day, it very frequently induced an eczematous retinoid dermatitis. This pilot study provides some indications on what appears to be in several aspects a drug quite distinct from retinoids previously used in humans.
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A 60-year-old man was followed for 5 years for plaque stage mycosis fungoides (MF), follicular mucinosis (FM), and multiple recurrent acquired epidermal cysts on the face, scalp, right axilla, and inguinoscrotal areas. Topical nitrogen mustard and steroids, as well as systemic retinoids controlled the infiltrated lesions of MF, but had no effects on the cysts, which had to be removed surgically. Such cases have to be distinguished from MF in a tumor stage and may suggest that the recurrent cysts represent a paraneoplastic syndrome.
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