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J Viac

Publications and source records attributed to J Viac.

At least 91 records · Page 5Linked to original sources
PubMed1986

Involucrin expression in adnexal skin tumours. An immunohistological study.

The expression of involucrin was studied in a group of skin neoplasms, mostly of adnexal origin. As happens with other types of epithelial tumours, involucrin was detected in the most differentiated areas (presenting a squamoid or ductal differentiation). No reactivity was observed in non-epithelial skin tumours. These results suggest that involucrin is a specific marker for epithelial and adnexal differentiation of skin tumours and may thus be a useful aid in histopathologic diagnosis and classification of neoplasms.

Carcinoma↗
PubMed1986

Laryngeal papillomas: local cellular immune response, keratinization and viral antigen.

Various parameters of the local cellular response have been studied in 16 laryngeal papillomas from ten patients with recurrent papillomas as well as normal control laryngeal and tracheal tissue by indirect immunofluorescence on frozen sections using monoclonal antibodies specific for T-cell subsets, Langerhans cells (LC) and HLA-DR antigens. Keratinization was investigated with a monoclonal antibody KL1 recognizing an acidic 56.5 Kd keratin, which is a marker of suprabasal cells in stratified squamous epithelium and is absent from the basal layer. The presence of viral antigen was detected with a rabbit antiserum raised against SDS-dissociated purified virus. A mild inflammatory response was observed in most biopsies. Cytotoxic/suppressor T-cells were the predominant cells found in the lesions. Compared with normal epithelium, the number of LC was dramatically reduced in the papillomatous epithelium. High densities of HLA-DR-positive cells were found mainly in the corium. The keratinization process was disturbed in most specimens in that both basal and suprabasal compartments reacted positively with the KL1 monoclonal antibody. Viral antigen was present in the nucleus of very occasional epithelial cells in some samples.

Adolescent↗
PubMed1986

Epstein-Barr virus-transformed lymphocytes from patients with bullous diseases produce autoantibodies to cytokeratins.

Human cell lines obtained after Epstein-Barr virus transformation of lymphocytes from seven patients with bullous diseases (Bullous pemphigoid, Pemphigus) and five controls were screened for the production of autoantibodies against skin antigens. In five out of seven patients, the culture supernatants tested by indirect immunofluorescence on frozen sections of normal human skin and rabbit lip showed the production of autoantibodies with different specificities: basal epidermal cells, whole epidermis, Merkel cells, fibroblasts endothelial cells, etc. All autoantibodies were of IgM class and reacted with intracellular structures. Some of them were further tested by immunoblotting against epidermal keratins and were found to react with the main human epidermal keratins (56 to 67 kDa). In contrast, even when patients had circulating autoantibodies, no supernatant showed any reactivity against the antigens usually involved in these diseases, i.e., the dermoepidermal junction or the intercellular spaces of epidermis. Supernatants from controls did not show any reactivity by immunofluorescence. The results demonstrated that human lymphoid cell lines obtained from patients with bullous diseases elicited the production of anti-intermediate filament autoantibodies known to occur spontaneously in normal patients. It is suggested that this phenomenon may be linked to the blistering conditions that provoke tissue destruction.

Animals↗
PubMed1986

Flow cytometry for separation of keratinocyte subpopulations from the viable epidermis.

Human epidermal cell suspensions were analyzed and sorted with flow cytometry. The desmosome and differentiation-related KM48 monoclonal antibody was used for indirect immunofluorescence and permitted staining of keratinocytes at various stages of the cell maturation. Intensity of the staining correlated with the degree of differentiation. Three sorting gates were chosen to obtain subpopulations which varied distinctly in KM48 expression. The flow cytometry-sorted cells were characterized by their ultrastructural appearance and by the bullous pemphigoid antigen expression. According to the ultrastructure criteria, about 50% of the cells obtained from the "IF negative" gate were basal layer keratinocytes (45.5% expressed bullous pemphigoid antigen); 90% of the "intermediate" gate cells were spinal layer keratinocytes, and over 80% of the cells sorted through the "strongly IF positive" gate were of the granular layer type. The method of keratinocyte separation proposed allows samples to be obtained for further biochemical and functional studies on keratinocyte subpopulations in normal and pathologic skin.

Antibodies, Monoclonal↗
PubMed1986

Comparative studies on naturally occurring antikeratin antibodies in human sera.

Comparative studies on the specificity of the so-called antiepidermal antibodies (Abs) found in human sera were performed by immunoblotting, enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy (IEM). After a screening test by indirect immunofluorescence (IF), sera obtained from patients with various diseases and controls could be classified in 5 different groups according to the IF patterns on the epidermis: sera reactive with: (1) the stratum corneum (SC); (2) the upper layer (U-Cyt); (3) the whole epidermis (G-Cyt); (4) basal cells (B-Cyt); and (5) negative ones. By immunoblotting, all the 23 IF-positive sera were found to bind to one or more keratin bands, and did not show any reactivity with epidermal Nonidet P-40 soluble proteins. SC-Abs were mainly directed against a 67 kD Keratin band, whereas U-Cyt- and G-Cyt-Abs bound to both 58-56 kD and 67-63 kD keratins. B-Cyt-Abs reacted strongly with 63 kD Keratins and slightly with a 50 kD band. Antikeratin Abs were detected by immunoblotting even in the IF-negative sera. The ELISA study showed that sera with high IF titers contained high levels of antikeratin Abs. In the IEM study using sera containing U-Cyt- or B-Cyt-Abs, 2 distinct reaction patterns were demonstrated: U-Cyt-Abs stained tonofilaments of suprabasal keratinocytes, while B-Cyt-Abs characteristically reacted with those of basal cells. Moreover, SC-, U-Cyt-, and G-Cyt-Abs were absorbed out by insoluble epidermal proteins, and B-Cyt-Abs were decreased in titer after the absorption test. The present study provides strong evidence that most, though not all, human antiepidermal Abs are directed against different keratin polypeptides, and that antikeratin Abs commonly occur in almost all human sera.

Antibody Specificity↗
PubMed1986

Langerhans cells in human warts.

Seventy-six warts (15 plantar, 38 hand, 16 miscellaneous and seven anogenital lesions) taken from 55 patients, were studied by indirect immunofluorescence with monoclonal antibodies specific for T-cell subsets, Langerhans cells (LC) and HLA-DR antigen. The results were related to the presence of viral antigen. Approximately 80% of the lesions showed an infiltrate. Only 19 lesions contained helper/inducer or suppressor/cytotoxic T cells. The distribution of LC was abnormal in 65% of biopsies which contained LC in the dermis, and 29% were devoid of LC in the epidermis. Many lesions had reduced numbers of LC in the epidermis. The disappearance of LC from the epidermis was related to the presence of viral antigen, but not to the presence of particular T-cell subsets. Infiltrating cells were sometimes HLA-DR-positive, whereas basal cells did not express HLA-DR antigen, irrespective of the density of the infiltrate.

Adolescent↗
PubMed1986

Granular-cell tumours of the skin do not express carcino-embryonic antigen.

Granular-cell tumour (GCT) of the skin is an uncommon tumour of disputed histogenesis, that has been subjected to several immunohistochemical studies. The controversy existing in the literature concerning the expression of carcinoembryonic antigen (CEA) by GCT prompted us to study a series of 17 cases of cutaneous GCT by using an avidin-biotin-immunoperoxidase technique on routinely-processed tissue sections. No CEA activity was detected in any of the tumours screened. The reasons for this controversy are discussed.

Carcinoembryonic Antigen↗
PubMed1986

Expression of epidermal differentiation antigens in cultures of interspecific somatic hybrids (human keratinocytes X mouse fibroblasts 3T3-4E).

Interspecific somatic hybrids have been prepared by fusion of human epidermal cells with mouse fibroblasts 3T3-4E using PEG 4000. Expression of epidermal differentiation antigens (bullous pemphigoid antigens, BP, keratin subsets 55-57 k and 67 k), markers of basal and suprabasal cells, were studied by immunocytochemistry for 10 passages. These markers were detected in the hybrids early after fusion, indicating that cells from both compartments were able to fuse with 3T3-4E cells. However, the hybrids expressing high molecular weight keratins were no longer detected after 7 days in primary cultures and serial passages, whereas those expressing BP antigens and vimentin persisted. Low molecular weight keratins 52 K and 50 K were detected by SDS-PAGE at the second passage in precipitates formed between labeled hybrid lysates and total keratin rabbit antiserum. Karyotype analysis showed mainly murine chromosomes and a submetacentric human chromosome between the 6th and the 10th passage.

Animals↗
PubMed1986

Immunogold labeling of keratin filaments in normal human epidermal cells with two anti-keratin monoclonal antibodies.

We report on application of the highly sensitive and specific immunogold labeling method for ultrastructural investigation of keratin intermediate filament antigens in human epidermal cell suspensions. Triton X-100 pretreated cells proved accessible to the colloidal gold conjugate, thus enabling keratin filament bundles to be labeled. Anti-keratin KL1 and KL2 monoclonal antibodies were raised in mice after immunization with either human stratum corneum-isolated keratins or keratins extracted from human epidermal cells suspensions, respectively. Immunoelectron microscopy confirmed immunofluorescence and immunoperoxidase results of epidermal keratinocyte staining, and revealed two different antibody reactivity patterns: KL2 reacted with keratin filaments in keratinocytes of all epidermal layers, whereas antigen to KL1 was detected only on keratin of the suprabasal layers, not on the basal keratinocyte tonofilaments. The monoclonal antibody-recognized epitopes were specific for the keratin filaments. Vimentin-rich cells (melanocytes) were not stained in the same epidermal cell suspensions. Additionally, two distinct ultrastructural patterns of keratin filament epitope labeling were observed. KL1 and KL2 monoclonal antibodies react with two different antigenic determinants, depending on the stage of keratinocyte differentiation, and may therefore be used for immunohistochemical studies of various keratin-containing cells in normal and pathologic conditions.

Antibodies, Monoclonal↗
PubMed1985

Alterations in the expression of two epidermal differentiation antigens in human epidermal disorders.

The expression of an epidermal keratin subunit and a specific antigen of the keratinocyte membrane, two differentiation antigens in normal human epidermis, was studied in benign and malignant epidermal lesions by use of monoclonal antibodies KL1 (anti 55-57 Kd keratins) and KL3 (anti keratinocyte membrane antigen). In normal human epidermis, KL1 labelled all keratinocytes from the suprabasal layers, KL3 stained the intercellular spaces in all epidermal layers with a fluorescence intensity increasing from the basal to the more upper layers and recognized a keratinocyte membrane antigen as demonstrated in electron microscopy. Frozen or deparaffinized sections of basal cell carcinomas (BCC), squamous cell carcinomas (SCC) malignant melanomas, warts, and skin biopsies from benign lesions (psoriasis, lichen planus, bullous pemphigoid, lupus erythematodes, pemphigus, vasculitis) were tested with either KL1 or KL3 by indirect immunofluorescence and/or immunoperoxidase. Benign and malignant lesions in which modifications of the keratinization process and cell differentiation are known to occur (BCC, SCC, warts, psoriasis) showed the most severe alterations as compared to normal epidermis. With KL1 we observed an irregular staining of basal cells; a reorganization of keratin filaments and variable staining intensities within tumoral cells which did not express high MW keratins. With KL3 drastic alterations in the epidermal intercellular patterns and loss of reactivity of tumoral cells were noted. Conversely, the positivity of epidermal basal cells with KL1, in some cases, was the only modification noted in other skin lesions.

Antibodies, Monoclonal↗
PubMed1985

Antikeratin antibodies in serum and synovial fluid show specificity for rheumatoid arthritis in a study of connective tissue diseases.

Tests for antikeratin antibodies (AKA) were performed on 2152 disease-associated and control sera by indirect immunofluorescence (IF) on rat oesophagus substrate. The incidence of AKA was significantly raised in rheumatoid arthritis (37%) in comparison with systemic sclerosis (8%), psoriasis (7%), ankylosing spondylitis (6%), systemic lupus erythematosus (3%), and normal controls (2%). AKA were detected in synovial fluid obtained from patients with rheumatoid arthritis (RA) (48%) but not from patients with other conditions. Further experiments on AKA-positive sera showed reactivity with stratum corneum of rabbit prepuce and lips. A specific rabbit antihuman keratin antiserum was shown, by IF and inhibition studies, to have a different specificity from that of spontaneous human AKA. AKA were associated with the presence of subcutaneous nodules in RA (p = 0.05), but not with Raynaud's phenomenon, Sjögren's syndrome, or HLA-DR4 positivity. Rheumatoid factor (RF) was not associated with AKA either in RA or in RF-positive disease controls.

Antibody Specificity↗
PubMed1985

Heterogeneity of thymic epithelial cell (TEC) keratins--immunohistochemical and biochemical evidence for a subset of highly differentiated TEC in the mouse.

The mouse thymic epithelial network was studied using three different anti-keratin antibodies. One of these antibodies, KL1, exclusively recognized a small subset of medullary epithelial cells characterized by its content of a high molecular weight keratin (63 kD). Since epithelial differentiation is known to be associated with the acquisition of high molecular weight keratins, KL1-positive cells, which express the Ia antigen and secrete thymulin, may represent a subset of highly differentiated cells among mouse thymic epithelial cells (TEC). These data reflect the heterogeneity of the thymic epithelium and support the concept that distinct TEC subsets might provide the thymus with different microenvironments.

Animals↗
PubMed1985

[Kaposi's sarcoma: comparative immunohistochemical study and histogenic significance of endothelial markers].

The origin of spindle-shaped cells in Kaposi's sarcoma (KS) remains controversial. Non-specific histochemical reactions, electron microscopic examinations and immunostainings using antibody against factor VIII-related antigen (F VIII-RAG) and Ulex europaeus agglutinin I (UEAI) lectin as endothelial markers have given contradictory results. Immunohistochemical techniques were applied to 7 frozen skin biopsy specimen of KS from 5 elderly Mediterranean people and 1 renal allograft recipient, and a group of 27 other frozen cutaneous tumours including haemangio and lymphangiosarcomas, benign vascular lesions and various epithelial, melanocytic, fibrohistiocytic, fibrosarcomatous and muscular tumours. Using UEAI and antibodies against F VIII-RAG, HLA-DR and vimentin, a large proportion of positive KS spindle cells was found in all cases whereas cells were negative for keratin. Among the various immunoreactivity patterns observed in this study, a unique immunohistochemical profile was demonstrated for KS, angiosarcoma and endothelial cell, which strongly supports the endothelial origin of spindle cells in KS. Whereas F VIII-RAG, HLA-DR, vimentin and UEAI were sensitive endothelial markers, only F VIII-RAG appeared specific for endothelial cells since UEAI stained 2 squamous cell carcinomas and HLA-DR and vimentin were present in various mesenchymal and melanocytic tumours.

Adult↗
PubMed1985

A monoclonal antibody labelling the keratinocyte membrane: a marker of epidermal differentiation.

A murine hybridoma secreting an IgM monoclonal antibody (KL3) was produced by cell fusion of mouse myeloma cells with spleen cells from mice immunized with human epidermal keratins. On normal human epidermis KL3 stained the intercellular spaces from the stratum germinatum to the stratum granulosum with a fluorescence intensity increasing from the basal layer to the upper layers. Basal cells were not stained on the side facing the basement membrane. About 90% of free keratinocytes isolated after trypsinization were labelled by KL3 in a punctate staining. Immunoelectron microscopy allowed us to show that the antigen recognized by KL3 was exclusively localized on the keratinocyte membrane especially in the desmosomal plaques. KL3 reactivity was not modified by preincubation of skin sections with lectins showing a selective intercellular labelling of upper layers of epidermis or pemphigus antisera, nor by adsorption of the antibody on NP40 soluble proteins of the epidermis. Though KL3 reactivity was completely abolished after adsorption of purified keratins, no immunological reactivity of KL3 was detected with epidermal keratin polypeptides blotted on nitrocellulose paper. In psoriatic epidemis and epidermal tumors KL3 reactivity was drastically modified. These results suggest that KL3 recognized a keratinocyte membrane antigen implied in the epidermal differentiation process.

Animals↗
PubMed1985

[Granular-cell tumor (Abrikosov). Immunohistological study of 4 cases with review of the literature].

Granular-cell tumour (GCT) is a benign neoplastic proliferation first described by Abrikossoff (1), who considered it to be of muscular origin. Since then, however, the histogenesis of GCT has been a matter of serious controversy, and various cell types have been considered as being the origin of GCT. In this work we investigated the immunohistochemical profile of four cases of GCT using antibodies to several neural differentiation markers: S-100 protein, neurofilaments (NF), glial fibrillary acidic protein (GFAP). The results were compared to those obtained on three cases of schwannomas (S) and to those already reported in literature. Four cases of GCT were retrieved from the files of the Laboratory of Histopathology of the Clinic of Dermatology, Hôp. E.-Herriot. The tumours had been observed during a two-year-period (1983-1984), fixed in Bouin's fixative and embedded in paraffin. In parallel, three cases of S that were treated in the same way were also studied. This was performed on 3 mu-thick paraffin sections using the avidin-biotin-peroxidase complex method (kit Vectastain, Vector Lab., Burlingame, USA). The following antibodies were used: a) antiserum to protein S-100 (Dakopatts, Denmark) (working dilution 1: 50); b) monoclonal antibody to 200 Kd NF (Labsystem, Helsinki) (working dilution 1: 40): C) monoclonal antibody to GFAP (Biosoft, Paris) (working dilution 1: 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗