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Biomedical subjects

H Kerl

Publications and source records attributed to H Kerl.

At least 271 records · Page 15Linked to original sources
PubMed1989

Surface microscopy. A new approach to the diagnosis of cutaneous pigmented tumors.

Clinical guidelines for the diagnosis of pigmented lesions of the skin are not always reliable. Surface microscopy (SM) represents an interesting approach to this problem. For this in vivo investigation, a stereomicroscope, a glass slide, and immersion oil are used. In the present study, the various criteria of SM that cannot be discerned by the naked eye are correlated with the histopathological structures in step-sectioned specimens. Characteristic SM features such as the pigment network, "black dots," or "irregular extensions" were found to correspond to particular histological findings. SM opens a new dimension of clinical morphology for the diagnosis and differential diagnosis of malignant melanomas, dysplastic nevi, or nonmelanocytic pigmented neoplasms, and facilitates a more reliable preoperative assessment of these lesions.

Dermatitis, Seborrheic↗
PubMed1989

[Analysis of point mutations of Ha-ras gene in basaliomas and spinaliomas usiang the polymerase chain reaction (PCR) technic].

Polymerase chain reaction is a recently developed procedure to detect point mutations in human genomic DNA. The sensitivity and specificity of this technique which requires a very little amount of DNA, have allowed the large scale screening of tumors. The Authors report the detection of point mutations of Ha-ras gene at codon 12 in 12 basal cell carcinomas and 10 cutaneous squamous cell carcinomas by the use of polymerase chain reaction in paraffin-embedded tissue sections. The gene alteration was identified in 2 basaliomas whereas no squamous cell carcinoma showed point mutations. These results suggest that point mutations of Ha-ras gene do not represent a general activating mechanism in cutaneous epitheliomas.

Basal Cell Carcinoma↗
PubMed1988

Nuclear parameters in the superficial and deep portion of melanocytic lesions--a morphometrical investigation.

Morphometric techniques in diagnostic pathology of pigmented skin lesions are not yet well established. The so-called maturation of melanocytes (nevus cells) with progressive descent into the dermis is one important criterion to differentiate benign from malignant melanocytic lesions in conventional histology. We therefore examined morphometrically the nuclear parameters of melanocytes (nevus cells) in the superficial and deep portion of 120 pigmented skin tumors (40 cases each of malignant melanoma. Spitz's nevus and benign dermal nevus) with special emphasis on the "maturation to the depth". A "maturation parameter" (MP) was assessed in each individual case, calculating the ratio of the nuclear area in the deep portion and in the superficial portion. The mean values of MP were 0.720 +/- 0.11 for dermal nevi, 0.725 +/- 0.10 for Spitz's nevi and 1.125 +/- 0.11 for malignant melanoma. The difference between malignant melanoma and both groups of benign nevi was statistically significant (p less than or equal to 0.01). The efficiency of the maturation parameter was 0.95 for the distinction of dermal nevi and malignant melanomas, and 0.97 for the distinction of Spitz's nevi and malignant melanoma. Measurements of the superficial portion only revealed comparatively low efficiency values (0.70 and 0.56, respectively). Our results indicate that morphometric evaluations of the nuclear area of melanocytes (nevus cells) in the deep portion of the infiltrate are more discriminative than those in the superficial portions. The establishment of the MP allows a better differentiation between benign and malignant melanocytic lesions and therefore morphometric methods may obviously be a helpful tool in the diagnosis of melanocytic skin tumors.

Cell Nucleus↗
PubMed1988

HLA-DR-positive keratinocytes are associated with suppressor lymphocyte epidermotropism. A biomathematical study.

The expression of HLA-DR antigen on keratinocytes has recently been described as a frequent finding in various dermatologic disorders without restriction to a particular entity or a peculiar histologic reaction pattern, except for the association with a mononuclear dermal infiltrate. To determine the relationship of HLA-DR+ keratinocytes and T lymphocyte epidermotropism in human disease in vivo, 82 skin specimens were investigated by immunohistologic and stereologic methods and by two- and three-dimensional linear regression analysis. In randomly selected cases of various dermatoses, HLA-DR+ keratinocytes were associated with T lymphocyte epidermotropism. Furthermore, HLA-DR+ keratinocytes correlated particularly with the proportion of epidermotropic suppressor/cytotoxic cells. Our findings demonstrate that HLA-DR+ keratinocytes are associated with a particular pattern of epidermotropism, which may suggest an interaction of keratinocytes and T suppressor/cytotoxic cells in vivo.

Antibodies, Monoclonal↗
PubMed1988

Immunological studies on the occurrence and properties of chromogranin A and B and secretogranin II in endocrine tumors.

We investigated a variety of endocrine tumors for the presence of chromogranins A and B and secretogranin II. These antigens were identified by one- and two-dimensional immunoblotting and in some cases by immunohistochemistry. An antigen corresponding in electrophoretic behavior to adrenal chromogranin A was present in all types of tumors, including insulinomas, oat cell carcinomas, and Merkel cell tumors of the skin. Chromogranin B had a much more limited distribution. This antigen could not be detected in parathyroid adenomas, oat cell carcinomas, or Merkel cell tumors, either by immunoblotting and immunohistochemistry. The occurrence of secretogranin II was similar to that of chromogranin B, with the exception of a positive reaction in Merkel cell tumors. In benign pheochromocytomas, all three antigens were found consistently; whereas in two of three malignant pheochromocytomas, chromogranin B was absent. Our study establishes that in most cases chromogranins and secretogranin in tumors are identical to the adrenal antigens, but that these antigens are not always stored together. Chromogranin A is the most widely distributed marker for endocrine tumors.

Adrenal Gland Neoplasms↗
PubMed1988

[Direct light microscopy of pigment tumors of the skin].

Clinical guidelines for the diagnosis of pigmented skin lesions are not always reliable. Incident light microscopy provides an interesting approach to solving this problem. For this investigation a stereomicroscope, a glass slide and immersion oil are used. The various in vivo criteria of this method, which go beyond the changes discernible by the naked eye, are correlated with the histopathological structures. Incident light microscopy opens up a new dimension of clinical morphology for the diagnosis and differential diagnosis of malignant melanoma, dysplastic nevi or non-melanocytic pigmented neoplasms and facilitates a more precise preoperative assessment of these lesions.

Diagnosis, Differential↗
PubMed1987

NK cell density in malignant skin tumours--a stereological study.

We determined the density of natural killer (NK) cells in frozen sections of malignant melanoma (nine cases), squamous cell carcinoma (six cases) and non-neoplastic tonsil (five cases) by immunohistological and stereological methods. The mean density of NK cells in malignant melanoma (5.0 +/- 1.5 X 10(3)/mm3) and in squamous cell carcinoma (5.1 +/- 2.7 X 10(3)/mm3) was significantly lower than in germinal centres of normal human tonsils (5.0 +/- 0.8 X 10(4)/mm3). The NK cell/tumour cell ratio (0.03 +/- 0.015 in malignant melanoma and 0.02 +/- 0.015 in squamous cell carcinoma) is 10(2)-10(4) times lower than that commonly used for in vitro assays. The possible role of NK cells in malignant skin tumours should be viewed with caution.

Biopsy↗
PubMed1987

Transferrin receptor expression in normal skin and in various cutaneous tumors.

In the majority of human cells the transferrin receptor (TFR) plays an important role by mediating the cellular iron uptake. The TFR is especially expressed by proliferating cells and has been found in high amounts in malignant tumors. The distribution of the TFR in frozen sections of 89 skin biopsies of normal skin and of various cutaneous tumors was investigated using an anti-TFR monoclonal antibody (OKT9) and a 3-step immunoperoxidase method. Our results indicate that in normal human skin the TFR shows a characteristic microanatomical distribution in the basal cell layer correlated to the architectural pattern of the dermal-epidermal interface. In cutaneous lymphomas of high grade malignancy the TFR was expressed in virtually all cells compared to only 25-75% in low grade lymphomas. Malignant melanomas were strongly positive in the whole tumor tissue, whereas benign melanocytic nevi were largely negative. Obviously the immunohistochemical demonstration of the TFR may serve as prognostic indicator or diagnostic aid, respectively.

Antibodies, Monoclonal↗
PubMed1987

[Immunohistochemical classification of cutaneous lymphomas and pseudolymphomas].

We investigated 46 cases of cutaneous lymphoma and pseudolymphoma by immunohistochemical methods using a panel of monoclonal antibodies. Of the cutaneous T cell lymphomas, 2 did not show the classic helper phenotype but revealed a predominance of suppressor cells in one case and of immature thymocytes in the other. Cutaneous B cell lymphomas of low-grade malignancy were characterized by the presence of completely developed T zones between the B cell areas. B cell lymphomas of high-grade malignancy revealed an immunohistologically homogeneous infiltrate. Cutaneous pseudolymphomas can be classified in T cell pseudolymphomas (lymphocytic infiltration, lymphomatoid papulosis) and B cell pseudolymphomas. Lymphadenosis cutis benigna with germinal center cell differentiation was clearly distinguishable from other B cell pseudolymphomas, which are considered to comprise mainly peripheral B lymphocytes. Immunohistological methods are obviously useful in the classification of lymphoproliferative diseases of the skin and can make a contribution to increasing our understanding of them.

Antibodies, Monoclonal↗
PubMed1986

Langerhans cell density in epithelial skin tumors correlates with epithelial differentiation but not with the peritumoral infiltrate.

We investigated the intraepithelial density of Langerhans cells in 17 epithelial skin tumors by immunohistologic and morphometric methods. There was a significant difference between seborrheic keratosis (Langerhans cell density 431 +/- 31/mm2; normal epidermis: 378 +/- 20/mm2), basal cell carcinoma (28 +/- 6/mm2), and squamous cell carcinoma (100 +/- 21/mm2). No correlation was found between the Langerhans cell density and the number of intraepithelial T lymphocytes or the extent of the peritumoral inflammatory infiltrate. A significant inverse correlation was demonstrated between mean nuclear area of the epithelial tissue and the Langerhans cell density (r = -0.7; p less than 0.05). These data indicate that the number of Langerhans cells does not influence the extent of the antitumoral immune response. The correlation with the level of epithelial differentiation may be due to different homing conditions.

Antibodies, Monoclonal↗
PubMed1986

[Classification and prognosis of cutaneous T-cell lymphomas].

Modern concepts on the classification and prognosis of cutaneous T-cell lymphomas are discussed in this paper. The full spectrum of cutaneous T-cell lymphomas is not yet known. A new classification of histomorphological types of mycosis fungoides and Sézary's syndrome in correlation with prognostic features is proposed.

Humans↗
PubMed1985

[Importance of immunohistochemistry of skin tumors].

Immunohistological demonstration of cell- and tissue-specific antigens in microscopic slides has remarkably influenced the classification of certain cutaneous neoplasms. The following markers are of particular interest in dermatopathology: cell surface antigens of lymphocyte subpopulations, intracytoplasmic immunoglobulins, intermediate filaments, neural markers, epithelial cell membrane antigens, and endothelial products. During the last years, these methods have contributed to our understanding of histogenesis and classification especially of cutaneous lymphomas, epithelial neoplasms, neurogenic tumors, and angiosarcomas.

Antibodies, Monoclonal↗
PubMed1985

The intermediate filament cytoskeleton of cutaneous neuroendocrine carcinoma (Merkel cell tumour). Immunohistochemical and biochemical analyses.

The presence and distribution of cytokeratins, neurofilament proteins, vimentin and glial fibrillary acidic protein were studied in 10 cutaneous neuroendocrine carcinomas (CNEC) by immunohistochemical techniques, using specific antibodies. In all cases tumour cells were specifically stained with antibodies to mouse liver cytokeratin component D in paraffin-embedded formalin-fixed and frozen sections. Moreover, one- and two-dimensional SDS-polyacrylamide gel electrophoresis of high salt/detergent resistant cytoskeletal residues from tumour material, isolated by microdissection from frozen sections, revealed the presence of cytokeratin components 8 and 18 which are characteristic constituents of cytokeratin filaments of simple epithelia. Neurofilament proteins were detected by immunocytochemistry in tumour cells from 2 patients, from whom frozen material was available, and their presence was also positively identified in cytoskeletal residues by immunoblotting using specific antibodies. Glial fibrillary acidic protein and vimentin could not be demonstrated in tumour cells. Our studies did not confirm the suggested origin of CNEC from epidermal Merkel cells.

Adenocarcinoma↗