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Biomedical subjects

J Kanitakis

Publications and source records attributed to J Kanitakis.

At least 73 records · Page 4Linked to original sources
PubMed1998

Merkel cells in hyperplastic and neoplastic lesions of the skin. An immunohistochemical study using an antibody to keratin 20.

BACKGROUND: Merkel cells are neuro-endocrine cells present in the basal layer of the human epidermis and the outer root sheath of hair follicles. OBJECTIVE AND METHOD: In order to gain further insight into the as yet ill-defined involvement of Merkel cells in skin diseases, we studied the distribution of these cells in formalin-fixed, paraffin-embedded sections of 165 inflammatory, hyperplastic or tumoral skin lesions of various anatomic locations, with a monoclonal antibody to keratin 20. RESULTS: Lesions with frequently increased Merkel Cell numbers included actinic keratosis, fibrous papules of the face and some conditions with (immature) hair follicle differentiation. CONCLUSION: These results suggest that Merkel cell hyperplasia is unrelated to epidermal proliferation but that it is rather specific to a limited number of skin diseases.

Antigen-Antibody Reactions↗
PubMed1998

The atrophic variant of dermatofibrosarcoma protuberans in childhood: a report of six cases.

Dermatofibrosarcoma protuberans (DFSP) is typically diagnosed during early adult life at a tumoral stage. It occurs only rarely in children. We report six childhood cases of DFSP which presented initially with the misleading clinical appearance of atrophic plaques, and we review over 140 cases of DFSP in childhood. As compared with adult forms, DFSP in children does not show distinctive features except for a tendency for acral localization. The diagnosis is difficult because of the slow course of the lesions, which present initially as apparently benign atrophic morphoeaor keloid-like plaques. We believe that DFSP in childhood is probably under-estimated, as a significant proportion of patients diagnosed as young adults had an onset several years earlier. Better knowledge of the initial appearance is important for making an early diagnosis and for an easier surgical treatment.

Adolescent↗
PubMed1998

[Epidermolysis bullosa acquisita and hepatitis C].

INTRODUCTION: Epidermolysis bullosa acquisita is a bullous dermatosis. Its etiology remains unknown and the efficacy of its treatment is low. OBSERVATION: We report the first association between epidermolysis bullosa acquisita, chronic hepatitis C and cryoglobulinemia, healing with interferon alpha and ribavirine. DISCUSSION: We suggest a role for hepatitis C virus in the pathogenesis of epidermolysis bullosa acquisita. We suppose a synthesis of autoimmune antibodies in a dysimmune environment. Interferon alpha and ribavirine might be a new therapeutic avenue but further studies are necessary to confirm it.

Adult↗
PubMed1998

[Ofuji's papulo-erythroderma: treatment with cyclosporin A].

BACKGROUND: Papuloerythroderma of Ofuji is an uncommon condition characterized by diffuse pruriginous eruptions of infiltrating papulae. The large folds are not involved. The eruptions are associated with lymphopenia and eosinophilia. Very few cases have been reported in the literature and because of their heterogeneous nature, there is some debate as to whether this is a single clinical entity or a particular presentation of erythrodermia; Immunomodulation is recommended. CASE REPORT: A 73 year-old man of asian origin living in France presented chronic pruriginous erythrodermia with flat purplish-brown confluent papulae which did not involve the large folds. Eosophilia and lymphopenia were present. The biopsy specimen evidenced dermal infiltration with CD4+CD45+RO+ T cells, eosinophils and DC1a+ dendritic cells. Further explorations did not reveal any sign favoring lymphoma, carcinoma or underlying infection. Dermocorticoids, PUVA-therapy and interferon-alpha were ineffective. Considerable clinical improvement was obtained with cyclosporine A. DISCUSSION: We used ciclosporine A in our patient after repeated failure of other therapies reported to be effective in this dermatosis. Despite the favorable outcome, this therapeutic approach should be used with prudence.

Aged↗
PubMed1997

Linear IgA bullous dermatosis with IgA antibodies exclusively directed against the 180- or 230-kDa epidermal antigens.

This study describes the presence in sera from patients with linear IgA bullous dermatosis (LABD) of IgA antibodies specific for 230- or 180-kDa epidermal antigens. Of 11 patients' sera with IgA antibodies reactive with the epidermal antigens obtained from cultured keratinocytes, 6 sera recognized the 230-kDa antigen and co-migrated with the polypeptide recognized by a human monoclonal antibody against the 230-kDa bullous pemphigoid antigen (BPAgl). Five sera recognized the 180-kDa antigen and co-migrated with the polypeptide stained by a polyclonal antibody to the 180-kDa bullous pemphigoid antigen (BPAg2). None of these LABD sera contained IgG antibodies reactive with the basement membrane zone antigens and none labeled a 97-kDa epidermal antigen or a 290-kDa dermal antigen. Immunoaffinity-purified IgA antibodies from the 230 kDa band further reacted with the epidermal side of the skin basement membrane zone. Epitope mapping with rBP55, a fusion protein containing the C-terminal end of BPAg1, suggested that the major antigenic epitopes for LABD and BP antibodies on the 230-kDa antigen are different. Only one serum with IgA antibodies was found to label rBP55, contrasting with nine of ten BP sera reacting with this protein. Our study demonstrates the presence of an exclusive IgA response against the 230- or 180-kDa antigens in a subset of patients with LABD.

Adult↗
PubMed1997

Expression of the nm23 metastasis-suppressor gene product in skin tumors.

Nm23 is a gene with a putative metastasis-suppressor function, whose expression is inversely correlated with the metastatic potential of some solid malignancies. Because very few data exist concerning the role of nm23 in skin tumors, we studied the immunohistochemical expression of nm23 gene product in frozen sections of normal skin and of 104 cutaneous benign or malignant, epithelial and mesenchymal tumors. Nm23 was found expressed within basal cells of the epidermis and its appendages. All basal cell carcinomas showed diffuse immunoreactivity predominating within cells located at the periphery of tumor masses; in contrast, most squamous cell carcinomas, premalignant lesions and the benign epithelial lesions studied showed very weak, if any, immunoreactivity. Benign nevi and most malignant melanomas expressed nm23 immunoreactivity and the pattern observed was similar between primary and metastatic lesions. These results show that nm23 is differentially expressed in cutaneous tumors. It seems likely that the strong immunoreactivity of basal cell carcinomas, contrasting with the almost non-expression in squamous cell carcinomas, reflects the different metastatic potential of these two types of tumors. In melanomas, no direct correlation between the metastatic phenotype and nm23 expression could be detected. Our results suggest that the nm23 gene is involved in cutaneous carcinogenesis; its precise role deserves further study.

Antigens, Neoplasm↗
PubMed1997

Comparative nuclear morphometric analysis of aggressive and non-aggressive squamous cell carcinomas of the skin.

Squamous cell carcinomas (SCC) are the most frequent tumours complicating organ transplantation. Whereas most SCC can be successfully treated with conventional surgery, other lesions show an aggressive course with recurrence and metastases. We assessed the value of nuclear morphometry in detecting tumours with an ab initio potential for aggressive course. Nuclear perimeter, area, feret X and feret Y were calculated semi-automatically on an image analyzer on histological sections of 15 non-aggressive, 15 aggressive and 6 recurrent SCC developed in seven organ graft recipients. We found statistically significant differences for all the parameters studied between recurrent and initially aggressive SCC, and, to a lesser extent, between non-aggressive and aggressive SCC. These results suggest that some SCC have ab initio a potential for more aggressive evolution; morphometry can be a useful adjunct in order to better study these lesions.

Adult↗
PubMed1997

External anogenital lesions in organ transplant recipients. A clinicopathologic and virologic assessment.

BACKGROUND AND DESIGN: In a series of patients treated at a university department of dermatology, we assessed the clinicopathologic features of external anogenital lesions in organ transplant recipients. For 6 years, 1002 recipients with various dermatologic problems underwent assessment for the presence of proliferative external anogenital lesions; these lesions were examined histologically and virologically for the presence of human papillomaviruses (HPV). RESULTS: Twenty-three patients (2.3%) presented with anogenital lesions, women being more often involved. Clinicopathologic examination revealed 18 anogenital warts, 3 cases of bowenoid papulosis, 1 giant condyloma, and 1 in situ carcinoma. Other viral coinfections were frequent. The lesions were extensive and refractory to treatment in 13 patients, but lesions in 7 were cured alter the immunosuppressive treatment was tapered of discontinued. Dysplastic changes were frequent on histologic examination. Twenty-one lesions contained HPV; 6 of 13 patients with HPV DNA in their lesions harbored oncogenic types that predominated in dysplastic lesions. In some patients, the same HPV types were detected within cutaneous and anogenital lesions, suggesting self-contamination. CONCLUSIONS: External anogenital lesions are more rare than cutaneous lesions in organ transplant recipients. These lesions may represent a marker of immunosuppression, especially when they are extensive. Their clinical aspect is often misleading; furthermore, because of the presence of dysplastic histologic aspects and oncogenic HPV types, they could be susceptible to malignant transformation, necessitating regular surveillance.

Adult↗
PubMed1997

Expression of corneodesmosin in the granular layer and stratum corneum of normal and diseased epidermis.

The stratum corneum (SC) has long been considered as a sort of inert membrane destined to be shed at the surface of the epidermis. During the last two decades, however, several lines of evidence have been reported, suggesting that active physical and chemical changes take place in the horny layer despite the absence of intracytoplasmic organelles. In particular, processing of filaggrin, replacement of the plasma membrane by a ceramide envelope and constant, progressive modification of extracellular lipid multilayers have been put forward. Recently, attention has focused on the intercellular junctions, which may be involved in the regulation of SC desquamation. Corneodesmosin, a newly discovered protein of s.c. desmosomes (corneodesmosomes), is synthesized at the latest stages of keratinocyte differentiation and persists between the horny cells until desquamation occurs. In the present study, we performed immunohistochemical and immuno-ultrastructural investigations on corneodesmosin expression in various skin lesions characterized by abnormal production and/or retention of the horny layer. Our results suggest that corneodesmosin expression is independent from profilaggrin synthesis. We found corneodesmosin in almost all morphologically recognizable corneodesmosomal structures and specifically those which persisted up to the SC surface. Hyperkeratotic lesions which are characterized by an increased number of junctions showed intense immunoreactivity with anticorneodesmosin antibody. A complete absence of corneodesmosin was not observed in any disease. This finding, together with our previous biochemical studies, suggests that corneodesmosin may exert a protective function against proteolytic degradation of corneodesmosomes both in normal skin and in the pathological horny layer.

Antibodies, Monoclonal↗