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Biomedical subjects

J Kanitakis

Publications and source records attributed to J Kanitakis.

At least 127 records · Page 7Linked to original sources
PubMed1993

Acquired perforating dermatosis of diabetes mellitus and renal failure: further ultrastructural clues to its pathogenesis.

An ultrastructural study of a typical case of acquired perforating dermatosis in a patient with renal failure and diabetes mellitus is reported. Crystal-like microdeposits of an electron-lucid material were detected in the upper dermis, close to the transepidermal channel. Compact macrophage conglomerations surrounded the deposits, and a strong histiocytic response was present. Mononuclear inflammatory cells of "activated" type penetrated the acanthotic epidermis provoking basement membrane dissolution and widening of interkeratinocyte spaces. Collagen fibers were seen in the keratotic plug, indicating the process of transepidermal elimination. Our observation supports the hypothesis suggesting that some kind of storage phenomenon may be at the origin of perforating skin lesions in renal failure patients.

Collagen↗
PubMed1993

S100 protein and neuron-specific enolase on monocytic leukemic CD1+ cells, probable precursors of Langerhans cells.

Langerhans cells are characterized by specific markers, such as Birbeck granules and CD1a antigen. S100 protein and neuron-specific enolase are less specific but are expressed only on Langerhans cells among the cells of the phagocytic mononuclear system. In this study, the expression of these two antigens on many monocytic leukemic cells is shown. These cells could be precursors of Langerhans cells which have been transformed into malignant cells.

Antigens, CD↗
PubMed1993

Cutaneous mesenchymal tumour with haemangiopericytoma-like features.

A case of cutaneous mesenchymal haemangiopericytoma-like tumour affecting a 17-year-old male is presented. Clinical features were non-specific. The tumour was studied by light, electron microscopy and immunohistochemistry. The results of these studies suggested the diagnosis of a mesenchymal, poorly-differentiated tumour showing features of haemangiopericytoma. The clinical course after surgery was uneventful after a 9-month follow-up period.

Adolescent↗
PubMed1993

Keratinocyte proliferation in epidermal keratinocyte disorders evaluated through PCNA/cyclin immunolabelling and AgNOR counting.

The assessment of cell proliferation is important to our understanding of hyperproliferative disorders. In this work we evaluated the proliferation characteristics of epidermal keratinocytes in diseases with abnormal keratinization by two different methods (immunostaining for the proliferating cell nuclear antigen--PCNA and histochemical staining for nucleolar organizer region--associated argyrophilic proteins--AgNORs). Twenty-seven specimens from diseases with an abnormal keratinization were studied and compared with specimens of normal human skin. As compared with the latter, the numbers of PCNA-positive epidermal keratinocytes were increased in psoriasis, congenital non-bullous ichthyosiform erythroderma, epidermolytic hyperkeratosis and chronic dermatitis and decreased in ichthyosis vulgaris, X-linked ichthyosis and pityriasis rubra pilaris. In most cases a parallel modification of AgNORs was found. We conclude that although PCNA immunolabelling and AgNOR staining do not provide strictly correlated values, both appear as useful markers for the assessment of keratinocyte proliferation in epidermal disorders.

Autoantigens↗
PubMed1993

[The dermal dendrocyte].

Dermal dendrocytes represent a population of resident cells of the dermis identified recently by virtue of the immunohistochemical expression of the coagulation factor XIIIa (fXIIIa). These dendritic cells of bone-marrow origin bear particular histoenzymatic and immunohistochemical features, some of which are shared with antigen-presenting cells; however, they are clearly distinct from epidermal Langerhans cells. Dermal dendrocytes could act as macrophages, antigen-presenting cells or participate in the homeostasis of macromolecules of the dermis. These cells give rise to some cutaneous tumours and seem involved in inflammatory dermatoses where they act by means of cytokine production; they could even represent targets of HIV infection. Future functional studies will hopefully lead to a better understanding of their precise role in normal and diseased skin, which remains presently partly speculative.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[Extra-abdominal desmoid tumor. Microscopic aspects and histogenesis].

Extra-abdominal desmoid is an unusual and underreported tumour in dermatological literature. We report a new case of such a lesion which was subjected to light, electron-microscopic and immunohistochemical studies. The results showed that proliferating cells exhibit features of myofibroblasts, both at the ultrastructural study (presence of cytoplasmic myofilaments) and the immunohistochemical study (cytoplasmic expression of vimentin and muscle-specific actin). Since these findings strongly suggest that desmoid tumour originates from myofibroblasts the term (extra-abdominal) "myofibroblastoma" could be proposed.

Female↗
PubMed1993

Proliferation characteristics of cutaneous squamous cell carcinomas developing in organ graft recipients. Comparison with squamous cell carcinomas of nonimmunocompromised hosts by counting argyrophilic proteins associated with nucleolar organizer regions.

BACKGROUND AND DESIGN: Cutaneous squamous cell carcinomas (SCCs) are a frequent complication in organ graft recipients (OGRs). The clinical evolution of these lesions has been a matter of controversy. We studied, by the technique of counting argyrophilic proteins associated with nucleolar organizing regions, the proliferative profile of 11 SCCs developing in six OGRs and compared it with the profile in a group of 18 nonimmunocompromised patients with SCCs. The density of the inflammatory cellular peritumoral infiltrate was also assessed semiquantitatively. RESULTS: The SCCs in OGRs and controls contained similar numbers of argyrophilic proteins associated with nucleolar organizing regions; however, the density of the inflammatory cellular peritumoral infiltrate was much lower in OGRs than in controls (2.00 +/- 0.77 vs 3.17 +/- 0.79). CONCLUSIONS: The proliferative potential of SCCs developing in the setting of iatrogenic immunosuppression does not seem to be different from that of SCC in nonimmunocompromised hosts; however, since metastatic SCCs are known to have a reduced density of the inflammatory cellular peritumoral infiltrate as compared with nonmetastatic cases, SCCs in OGRs could have a higher metastatic potential than similar lesions developing in a control population.

Adult↗
PubMed1992

Nucleolar organizer region enumeration in keratoacanthomas and squamous cell carcinomas of the skin.

Keratoacanthomas (KA) and squamous cell carcinomas (SSC) are epithelial skin tumors exhibiting distinctive clinical and histologic features. However, the differential diagnosis between them in individual cases may be difficult or even impossible. In this article the authors examine the possibility that enumeration of associated proteins of nucleolar organizer regions (AgNOR) could be of help in differentiating KA from SCC. AgNOR counting, performed on unequivocal cases of SCC (n = 20) and KA (n = 16) showed statistically significant higher AgNOR counts in SCC (6.29 +/- 0.91) compared with KA (3.80 +/- 1.62). This result speaks in favor of the different biologic nature of SCC and KA; however, due to significant overlap between the two groups, AgNOR enumeration alone is not sufficiently discriminating so as to be used diagnostically in cases with borderline histologic features.

Carcinoma, Squamous Cell↗
PubMed1992

Effect of cyclosporins A, G, and H on normal and ichthyotic keratinocyte growth in culture.

Cyclosporin A (CsA) was first used in organ transplantation and for the treatment of autoimmune disorders because of its strong immunosuppressant properties. Several laboratory studies have demonstrated that CsA exerts an inhibitory action on the growth of various cell types in culture, including human skin cells. Such an influence on epidermal keratinocytes, if not associated with the serious adverse effects of CsA medication, would be of interest for the treatment of hyperproliferative genodermatoses such as non-bullous congenital ichthyotic erythroderma (NBCIE). In our study, we used cyclosporin G (CsG) and H (CsH), analogues CsA, to examine the impact of these three cyclosporins on normal and ichthyotic keratinocyte growth in vitro. Epidermal cells were grown in a low-calcium, serum-free medium in the presence or absence of cyclosporins A, G or H (1-10 micrograms/ml). The effects of a 72-h exposure to the drugs were evaluated by cell counting, 3H-thymidine incorporation and cytofluorimetric analysis of the BrdU-labelled cell suspensions. Our findings indicate a dose-dependent keratinocyte growth inhibition by the three cyclosporins. The data obtained with the three quantitation methods were in agreement and the cyclosporin-mediated effects were observed in both normal and ichthyotic keratinocyte cultures. CsG and CsH proved less effective than CsA, which induced a highly significant reduction even at 1 microgram/ml. Our results suggest, however, that ichthyotic keratinocytes are more sensitive to CsG and H when compared with normal cells (50% inhibition of 3H-thymidine uptake at significantly lower doses). A possible therapeutic action of non-toxic doses of CsG and CsH on NBCIE and other hyperproliferative epidermal diseases needs to be confirmed clinically.

Cell Division↗
PubMed1992

Factor-XIIIa-expressing dermal dendrocytes in Kaposi's sarcoma. A comparison between classical and immunosuppression-associated types.

The histogenetic origin of Kaposi's sarcoma is a matter of controversy, with recent reports claiming it to derive from the factor-XIIIa-positive dermal dendrocyte rather than endothelial cells. We investigated the potential role of factor-XIIIa-positive dermal dendrocytes in the genesis of both classical (endemic) and immunosuppression-associated Kaposi's sarcoma. Thirteen cases of classical and 16 cases of immunosuppression (mostly AIDS)-associated Kaposi's sarcoma were immunostained with antibodies to factor XIIIa and to the blood-group antigen H, recognizing endothelial cells. Factor-XIIIa-positive cells were consistently antigen-H-negative and represented only a small percentage (usually less than 10%) of the proliferative cells. Their relative density tended to be decreased in immunosuppression-associated Kaposi's sarcoma when compared with that of the classical form. These results do not support the view that dermal dendrocytes may be the cells of origin of Kaposi's sarcoma; conversely, their decreased density in cases of immunosuppression-associated Kaposi's sarcoma could be related to immunosuppression and may account for more rapid tumour growth.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Epidermolysis bullosa acquisita in a 3 1/2-year-old girl.

A 3 1/2-year-old girl had a subepidermal bullous eruption with immunopathologic features that were consistent with epidermolysis bullosa acquisita or bullous systemic lupus erythematosus. This report highlights the difficulty encountered in distinguishing between epidermolysis bullosa acquisita and other bullous disorders that involve the dermoepidermal junction and the need for modern immunologic investigations in the diagnosis of bullous diseases in children.

Child, Preschool↗
PubMed1992

Expression of neuron-specific enolase immunoreactivity by cutaneous and extracutaneous Langerhans-cell histiocytoses ("X").

The immunohistochemical expression of Neuron-Specific Enolase (NSE) and of S100 protein was studied in 10 cases of cutaneous and 19 cases of extracutaneous Langerhans cell histiocytoses (LCH), including acute/proliferative forms (cutaneous Letterer-Siwe disease) and chronic/granulomatous forms (eosinophilic granuloma, Hand-Schüller-Christian disease). Of the LCH cases, 18 (62%) exhibited detectable NSE-immunoreactivity as compared to 82.8% for S100. NSE expression was found more frequently and intensely within acute (as compared to chronic) forms of LCH. This result lends further support to the cellular unicity of LCH, but also suggests some degree of heterogeneity among LCH cells. It can be speculated that NSE-expression is correlated with the proliferation/activation state of (abnormal) Langerhans cells.

Bone Diseases↗
PubMed1992

Alpha-6 (CD 49f) integrin expression in genetic and acquired bullous skin diseases. A comparison of its distribution with bullous pemphigoid antigen.

Bullous pemphigoid (BP) antigen and alpha 6 integrin are hemidesmosome-associated glycoproteins of basal keratinocytes. In this work, the immunoreactivity of antibodies to BP and to alpha 6 in salt- or dispase-split human skin, and in 46 biopsy specimens of various genetic and autoimmune bullous dermatoses taken from various body sites, was studied by double-labeling immunofluorescence. In all specimens, both antigens localized at the same side of the blisters observed, i.e. the roof of the bulla in cases with a junctional or dermolytic cleavage, or the floor of the blister in those with intraepidermal cleavage. Immunostaining for alpha 6 was strong and present in all specimens studied, whereas the one obtained with the BP serum was absent from some specimens. These results show that the BP antigen and the alpha 6 integrin colocalize at the level of cleavage in bullous diseases; however, the more consistent and reproducible reactivity obtained with the anti-alpha 6 antibody suggests that this should be preferentially used in the immunohistochemical investigation of bullous dermatoses.

Antigens, Surface↗