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Biomedical subjects

A Schauer

Publications and source records attributed to A Schauer.

At least 109 records · Page 6Linked to original sources
PubMed1984

Distinction of nephroblastomas from other childhood tumors using antibodies to intermediate filaments.

Ten nephroblastomas were investigated by antibodies to intermediate filaments. In seven cases, which in light microscopy were characterized by the presence of blastema and tubules, immunofluorescence microscopy with IF-specific antibodies reveals expression of cytokeratin and vimentin in blastema cells, while tubules were only labelled by the cytokeratin antibodies. This result was independent of whether the conventional cytokeratin antibody or monoclonal antibodies specific for cytokeratin 18 were used. Stroma cells were vimentin-positive. In two cases nephroblastomas were undifferentiated and also lacked tubuli formation. In both these tumors blastema cells were vimentin-positive and cytokeratin-negative. Finally one case of clear cell sarcoma of the kidney could only be labelled by the vimentin antibody. Thus antibodies to intermediate filaments seem to be useful tools to distinguish nephroblastomas from neuroblastomas or rhabdomyosarcomas, especially in cases of metastasis.

Child↗
PubMed1984

Antibodies to different intermediate filaments as histogenetic tumormarkers.

Fifty primary carcinomas, nineteen nonmuscular sarcomas, ten rhabdomyosarcomas, one malignant ependymoblastoma and seventeen sympathetic derived tumors have been studied to determine what type of intermediate filaments they express, using affinity purified antibodies to prekeratin, vimentin, desmin, glial fibrillary acidic protein (GFA) and to the different neurofilament proteins. The tissue was ethanol fixed and paraffin embedded before use. In all carcinoma cases the tumor cells are stained by antibodies to prekeratin, whereas tumor cells in nonmuscular sarcomas could only be labeled by antibodies to vimentin. In the cases of rhabdomyosarcomas tumor cells are clearly decorated by antibodies to desmin. The one case of malignant ependymoblastoma was positive when tested with antibodies directed against glial fibrillary acidic protein (GFA). While most of the sympathetic derived tumors react positively with sera directed against the different neurofilament proteins, three neuroblastomas did not react with sera against any of the known intermediate filament types. Wider use of such sera would seem particularly useful in cases such as neuroblastomas, undifferentiated carcinomas, lymphomas and rhabdomyosarcomas.

Antibodies, Neoplasm↗
PubMed1984

[Malignant soft tissue tumors].

This article is a survey of actual aspects. With regard to frequency, the malignant fibrous histocytoma comes first, followed by lipo- and fibrosarcoma, synovial sarcoma, malignant schwannoma, malignant tumours proceeding from arteries and veins and the unstriated musculature. Staging and grading of these tumours are difficult. Until now their overall TNM-classification was not possible due to insufficient hard criteria.

Adult↗
PubMed1983

Histology and histogenesis of two different types of inverted urothelial papillomas.

Inverted papillomas are rare tumors of the lower urinary tract. Among 1829 reclassified tumors of the urinary bladder, renal pelves, ureters, and urethra, there were 40 (2.2%) inverted papillomas. The great majority of these were localized in the bladder. Because of distinctive histologic features and patterns of growth it is possible to differentiate between two basic types of inverted papillomas which were termed "trabecular" and "glandular." The trabecular type consists of widely branched, anastomosing cords of urothelial cells originating directly from the overlying transitional epithelium. The trabeculae are arranged horizontally or perpendicularly to the surface epithelium and occasionally exhibit peripheral palisading of the cells. The glandular type is characterized by multiple round to oval islands of proliferated urothelial cells together with pseudoglandular and true glandular structures which are often still connected with the surface urothelium. The gland-like structures are lined by stratified urothelium, the true glands by mucus secreting columnar epithelium. Sometimes glandular metaplasia of an intestinal type with goblet cell formation could be observed. Inverted papillomas of the trabecular type arise histogenetically from a proliferation of the basal cells of the urothelium. The glandular type develops apparently from a proliferative cystitis cystica and glandularis which, therefore, should be considered a potentially preneoplastic lesion. The predominant view of the biological behavior of inverted papillomas is that of a benign neoplastic lesion. Morphologic findings supplied some arguments in favor of a low grade malignant potential of these tumors. However, their malignant transformation seemed to be much lower than that of exophytic papillomas.

Adult↗
PubMed1983

Early stages of chemically induced liver carcinogenesis by oral administration of the antihistaminic methapyrilene hydrochloride.

The antihistaminic drug methapyrilene hydrochloride, which induces liver tumors in rats, was administrated orally to female Wistar rats. The animals were killed after 21, 38, 77, 119, 181, and 196 days. The activities of adenosine-5-triphosphatase (ATPase) and gamma-glutamyltranspeptidase (gamma-GT) in the liver were investigated histochemically. At 21 days, a homogeneous decrease of ATPase activity as well as a slight increase of gamma-GT activity was found in the periportal zone. Additionally, after 38 days hepatocellular foci with reappearance of gamma-GT occurred mainly in the periportal zone. After 119 days, foci with increased gamma-GT activity as well as a significant reduction of ATPase activity could be observed predominantly in the periportal region. The size and number of these putative preneoplastic foci were increased according to the time of administration of methapyrilene hydrochloride. After 181 days of methapyrilene hydrochloride treatment three of five animals developed hyperplastic nodules with corresponding alterations of enzyme activities. Methapyrilene hydrochloride-a carcinogen with an unknown mechanism of reaction-produces preneoplastic changes that are analogous to the well known preneoplastic lesions in the liver observed after administration of other carcinogenic agents.

Adenosine Triphosphatases↗
PubMed1983

Immunohistochemical and biochemical detection of uridine-diphosphate-glucuronyltransferase (UDP-GT) activity in putative preneoplastic liver foci.

Preneoplastic liver foci were produced in female Wistar rats by the administration of 2-acetylaminofluorene (0.03% w/w) in the diet for 174 days. Increased UDP-glucuronyltransferase (UDP-GT) could be visualized immunohistochemically in the same focal areas which were ATPase-negative and gamma-glutamyltranspeptidase-positive. Immunohistochemical detection was possible using rabbit anti-UDP-GT and peroxidase-labeled swine anti-rabbit immunoglobulins. The results of immunohistochemistry were substantiated by enzyme determination in microdissected material. UDP-GT activity was 5-fold higher in focal areas in comparison with the surrounding liver tissue. Increased UDP-GT activity in conjunction with the altered pattern of other drug-metabolizing enzymes is consistent with increased resistance of preneoplastic cells to the cytotoxicity of carcinogens. Immunohistochemical detection of UDP-GT may provide a new marker for preneoplastic lesions which, in conjunction with other markers, may prove useful in analyzing the various stages of liver carcinogenesis and the remodeling of preneoplastic lesions after cessation of carcinogenic stimuli.

2-Acetylaminofluorene↗
PubMed1983

Biochemical quantification of ATPase activities during liver carcinogenesis.

In the course of chemically induced liver carcinogenesis as one of the earliest changes, the histochemically demonstrable focal loss of nucleoside 5'-triphosphatase activities (ATPase) is detectable. The exact quantitation and differentiation of these alterations can be achieved by biochemical analysis in microdissected preneoplastic foci. The preparation of focal tissue was facilitated using a microscopic-microdissecting apparatus [1]. By microanalytic determination of hydrolytic cleavage of 32P from gamma 32P-ATP a decrease of total ATPase activity to about 70% was found. Furthermore, the alteration of ATPase activities in course of chemically induced liver carcinogenesis in rats will be described.

Adenosine Triphosphatases↗
PubMed1982

An unusual case of adamantinoma of long bones.

Adamantinoma of the tibia is a rare bone lesion, in which it is impossible to predict the biological behaviour. A case of extremely late local recurrence and lung metastasis is presented. Additionally, the patient developed pneumothorax on the right side months before intrapulmonary metastasis could be detected by X ray. Finally 1 week before her death the young woman suffered from paraneoplastic severe hypercalcemia leading to hypercalcemic coma and pancreatitis.

Adolescent↗
PubMed1982

Various sympathetic derived human tumors differ in neurofilament expression. Use in diagnosis of neuroblastoma, ganglioneuroblastoma and pheochromocytoma.

We have extended our analysis of human tumors using antibodies specific for each of the five types of intermediate filaments to neuroblastoma, ganglioneuroblastoma, pheochromocytoma, ependymoblastoma, and alveolar soft part sarcoma. Tumor cells in the three cases of neuroblastoma, as well as in the single case of alveolar soft part sarcoma, did not react positively with sera directed against any of the five intermediate filament types. We suppose, therefore, that neuroblastoma at least may be derived from a cell type - possibly present in peripheral neurones - which in vivo has very few or no intermediate filaments. In ganglioneuroblastoma and in pheochromocytoma the tumor cells were positive when tested with antibodies directed against neurofilaments and negative with those directed against other intermediate filament types. The ependymoblastoma was positive when tested with antibodies directed against glial fibrillary acidic protein (GFA) and negative when tested with antibodies against other intermediate filament types. Use of antibodies to the different intermediate filament types appears to be a valid way in which to classify tumors, and so far the data presented here and elsewhere support the hypothesis that tumor cells retain the intermediate filament type typical of their cell of origin. Wider use of these sera would seem particularly useful in cases such as neuroblastoma, rhabdomyosarcoma or lymphoma where diagnosis is currently difficult using conventional histological stains.

Adolescent↗
PubMed1982

Expression of intermediate filaments in different human epithelial and mesenchymal tumors.

Fifty primary gastrointestinal and breast carcinomas, four embryonal rhabdomyosarcomas, six nonmuscular mesenchymal malignant tumors and one mesothelioma have been studied to determine what type of intermediate filaments they express, using affinity purified antibodies to prekeratin, vimentin and desmin and FITC or peroxidase labeled second antibodies. The tissues were alcohol fixed and paraffin embedded before use. In all carcinoma cases the tumor cells are stained by antibodies to prekeratin, while the vimentin antibody only decorates the stroma. Prekeratin positive tumor cells are not only seen in well differentiated tumors, but also in signet ring cell carcinomas. In the case of rhabdomyosarcoma the tumor cells clearly were decorated by antibodies to desmin, while the vimentin antibody only stained very few tumor cells. In cases of nonmuscular mesenchymal tumors, the tumor cells could only be labeled by antibodies to vimentin and not by antibodies to prekeratin or desmin. In biphasic tumors like mesothelioma, different parts of the tumor were separated by antibodies to prekeratin and vimentin.

Adenocarcinoma, Mucinous↗
PubMed1982

Antibodies to intermediate filaments as diagnostic tools: human gastrointestinal carcinomas express prekeratin.

Twenty-five primary gastrointestinal carcinomas have been studied using immunofluorescence microscopy with affinity-purified antibodies to prekeratin and to vimentin. The tissues were alcohol fixed and paraffin embedded before use. In all cases (i.e., one case of esophagal carcinoma, seven stomach carcinomas, and 17 large bowel carcinomas) the tumor cells are stained by antibodies to prekeratin. In cases in which only very few tumor cells are present, such as signet ring carcinoma, immunofluorescence with prekeratin antibody provides an easy way to visualize single tumor cells. When the same specimens were tested with antibodies to vimentin, the tumor cells were unstained, and only the fibroblasts and vessels of the stroma were decorated. Four of the tumors were also negative when tested with antibodies specific for either desmin, or glial fibrillary acidic protein or neurofilaments. Three metastases to the abdominal region from tumors originating in the ovary, stomach, and large bowel were like the primary tumors in that the tumor cells were positive when stained with antibodies to prekeratin and negative when tested with the antibodies to vimentin.

Adenocarcinoma↗