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Biomedical subjects

H Stein

Publications and source records attributed to H Stein.

At least 451 records · Page 25Linked to original sources
PubMed1989

Immunohistological determination of oestrogen receptor, progesterone receptor, and intermediate filaments in Leydig cell tumours, Leydig cell hyperplasia, and normal Leydig cells of the human testis.

Testicular Leydig cell tumours are able to produce oestrogens and can be induced by exogeneous oestrogen administration. Oestrogen and progesterone receptors, cytokeratin, vimentin, and proliferative activity were determined immunohistologically in human testes in six Leydig cell tumours, 14 cases of Leydig cell hyperplasia, and 13 cases with normal Leydig cells. While both steroid receptors were detected in about 70 per cent of the tumour cells in cryostat sections, no reaction was observed in normal Leydig cells. This supports the hypothesis of an enhanced receptor state in a Leydig cell subpopulation as a basic pathophysiological factor in the development of Leydig cell tumours. On cryostat sections, all tumours co-express cytokeratin and vimentin. Neither the receptors nor the intermediate filaments could be detected reliably in paraffin sections. The low proliferative activity of Leydig cell tumours corresponds to their benign clinical course.

Adult↗
PubMed1989

Vimentin expression of newly formed rat bile duct epithelial cells in secondary biliary fibrosis.

The intermediate filament profile and the growth fraction of hepatocytes and bile duct epithelial cells were studied in a rat model of biliary fibrosis secondary to common bile duct ligation and scission. Strong vimentin expression was observed in epithelial cells of newly formed bile ductules, while normal liver contained only few weakly positive bile duct epithelial cells. All epithelial cells reacted with a pan-cytokeratin antibody. A monoclonal antibody specific for human cytokeratin 7 selectively reacted with both normal and newly formed bile duct epithelial cells. The intermediate filament profile of hepatocytes was constant, showing no changes during proliferation or in periportal areas adjacent to excessive bile duct formations. The proliferation-associated antigen detected by the antibody Ki-67 was present in many hepatocytes, homogeneously distributed in the lobules, but was seen only in a small proportion of the epithelial cells of the newly formed bile ducts. We conclude that vimentin may serve as an indicator for cellular reorganization in the bile duct system, and that the epithelial cells of newly formed bile ductules in this particular model of secondary biliary fibrosis were most likely to be derived from an outgrowth of the biliary duct system and recruitment of preductular epithelial cells. No morphological or immunohistological evidence suggesting a derivation from hepatocytes by ductular metaplasia or from oval cells was obtained.

Animals↗
PubMed1989

Noninvasive diagnosis of congenital left coronary artery to right ventricle fistula by nuclear magnetic resonance imaging.

In two children with left coronary artery to right ventricle fistula, nuclear magnetic resonance imaging provided high-quality images of the course of the dilated coronary artery and its termination in the right ventricular apex. The advantages of this noninvasive multiplanar imaging technique for visualization of coronary fistulae and dilated coronary arteries are described. This report represents the first description of coronary artery fistula by nuclear magnetic resonance imaging.

Adolescent↗
PubMed1989

Identification of Epstein-Barr virus-infected cells in tonsils of acute infectious mononucleosis by in situ hybridization.

In situ hybridization with 35S-labeled Epstein-Barr virus (EBV) probes was applied to paraffin sections of tonsils from seven patients with clinical, serologic, and morphologic evidence of acute infectious mononucleosis. EBV genomes were demonstrated in activated lymphoid B blasts in the interfollicular and perifollicular zones in all these cases. However, in no case could EBV be identified in epithelial cells. These results are at variance with the current concept which attributes a central role to the tonsillar epithelium in primary EBV infection.

Acute Disease↗
PubMed1989

Immunoglobulin and T-cell receptor gene rearrangements in Hodgkin's disease and Ki-1-positive anaplastic large cell lymphoma: dissociation between phenotype and genotype.

We have determined the tumor cell immunophenotype and the rearrangement configuration of immunoglobulin and T-cell receptor genes in 39 cases of Hodgkin's disease (HD), six HD-derived cell lines and 22 cases of Ki-1-positive anaplastic large cell lymphomas (Ki-1-ALC). Rearrangements were observed in 11/39 HD cases, 15/22 Ki-1-ALC, and all cell lines. Epstein-Barr virus DNA was found in five HD cases, one cell line, and one Ki-1-ALC. Both HD and Ki-1-ALC frequently displayed a dissociated genotypic and phenotypic maturation status, i.e. an immature genotype in association with late activation markers. We postulate that the tumor cells in many cases of HD and some cases of Ki-1-ALC may be derived from immature lymphoid cells by a transformation process that superimposes characteristics of mature activated lymphocytes on these cells.

Antigens, Differentiation↗
PubMed1989

Towards a better definition of human leucocyte surface molecules.

At the 4th International Workshop on Human Leucocyte Differentiation Antigens workers from 525 laboratories jointly evaluated and/or submitted about 1100 different monoclonal antibodies to human leucocyte surface molecules. At the final conference of the workshop agreement was reached on 35 new cluster determinants (CDs) and subclusters. In addition, seven previously established clusters were redefined. This report provides basic information concerning the molecules defined by these antibodies and some highlights of the conference.

Antibodies, Monoclonal↗
PubMed1989

Computed tomography versus magnetic resonance imaging of the brain. A collaborative interinstitutional study.

A retrospective study (1983-1984) of magnetic resonance imaging (MRI) and computed tomography (CT) examinations in 471 patients with known pathology in the brain and craniocervical junction was conducted in order to determine the relative efficacy of MRI versus CT. All MRI examinations involved slice thickness greater than 10 mm, and only single-slice single-echo or multislice single-echo imaging techniques were available. These studies were evaluated independently by two neuroradiologists from a panel of six for anatomic abnormalities, lesion contrast, and radiologist's impression. Results, which excluded microadenomas of the pituitary and approximately 9% of studies in which consensus was not achieved by the readers, were as follows: (1) 14% of the studies were positive on MRI but normal on CT; (2) in 55% of the studies, MRI was better than CT; (3) MRI was equal or better than CT in 95% of the studies; and (4) CT was better than MRI in 5% (21/421) of the examinations. There were no patients in this series where CT was positive but MRI missed the abnormality.

Adult↗
PubMed1989

Fatal outcome of pelvic radiotherapy for carcinoma of the cervix in a patient with systemic lupus erythematosis.

Although there is an impression that patients with connective tissue disorders tolerate radiotherapy less well than other patients, this is not well documented in the literature. We present the case of a patient with a 7-year history of systemic lupus erythematosis who developed fatal pelvic necrosis as an unexpectedly severe complication after radiotherapy for carcinoma of the cervix.

Adult↗
PubMed1989

Nodular paragranuloma can transform into high-grade malignant lymphoma of B type.

A follow-up study of 537 cases of Hodgkin's disease, lymphocyte predominance type, nodular--designated as nodular paragranuloma (NP)--found simultaneous presence of (n = 11) or subsequent transition into (n = 3) a large cell lymphoma (LCL) in 14 cases. Morphologically, the LCLs were classified in ten cases as centroblastic lymphoma (malignant lymphoma, diffuse, large cell, non-cleaved cell), in three cases as immunoblastic lymphoma (malignant lymphoma, large cell, immunoblastic), and in one case as large cell anaplastic lymphoma. Eleven of the 14 LCLs were studied immunohistologically. Five cases showed a monotypic immunoglobulin (Ig) pattern, seven were positive to the monoclonal B-cell marker Ki-B3, and three showed both monotypic Ig and Ki-B3 positivity. With anti-Ig and Ki-B3, nine of the 11 LCLs could be classified as B-cell non-Hodgkin's lymphoma. Only one case of LCL exhibited the typical phenotype of Hodgkin cells, ie, positivity to anti-CD15 (3C4) and anti-CD30 (Ber-H2). A retrospective follow-up study of these secondary LCLs of B type revealed a longer survival time than that of primary B-type LCLs and other secondary LCLs. These findings indicate that B-type LCL is the most common outcome when NP progresses into a lesion of higher malignancy and provide further evidence of a close relationship of NP to the B-cell system. They also suggest that it would be clinically relevant to distinguish between cases of B-type LCLs secondary to NP and cases of LCLs without association with NP. This implies that signs of a preexisting NP should be looked for when a B-type LCL is diagnosed.

Adolescent↗
PubMed1989

In situ hybridization using biotinylated probes. An evaluation of different detection systems.

In situ hybridization with biotin-labelled DNA probes is a powerful tool for the detection of viral sequences in infected tissues. However, sensitivity is low when compared to radiolabelled probes. In order to evaluate the impact on staining results of the detection system applied, we have tested various reagents. In our hands the sequential application of streptavidin and biotinylated alkaline phosphatase or development with a monoclonal anti-biotin antibody and the APAAP method gave consistently the best results. Furthermore, nitro blue tetrazolium/bromochloroindolyphosphate seems to be most suitable as a substrate for the alkaline phosphatase in this case. Use of other reagents, especially of a streptavidin-biotinylated alkaline phosphatase complex, resulted in a significantly lower staining intensity.

Alkaline Phosphatase↗
PubMed1989

Azido glycols: potent, low molecular weight renin inhibitors containing an unusual post scissile site residue.

Azidomethyl-substituted 1,2- and 1,3-diols were prepared from Boc-cyclohexylalanal and evaluated as transition state analogue renin inhibitors, leading to the development of a small (MW less than 600), nanomolar inhibitor. Remarkable aqueous solubility enhancement followed the incorporation of an N-terminal urea functionality. Evaluation of selected compounds both in vivo and in vitro demonstrated that while transport across the intestine occurred upon id administration, extensive liver extraction resulted in low systemic levels.

Animals↗
PubMed1989

The expression of the CD3 antigen in Hodgkin's disease.

Tissue from 86 cases of Hodgkin's disease, fixed in formalin and embedded in paraffin, was immunostained for the T-cell marker CD3. Of these cases, 20 were selected on the basis of previous reactivity of Reed-Sternberg cells for T-cell associated antigens in frozen sections whilst the remaining 66 were retrieved from the routine pathology files. Five of the 20 selected cases and 22 of the retrieved cases showed predominantly cytoplasmic positivity in a subpopulation of Hodgkin and Reed-Sternberg cells. CD3 positive cells were present in all subtypes of Hodgkin's disease including three of nine lymphocyte predominance cases. It therefore appears that some Hodgkin and Reed-Sternberg cells can express the major T-cell antigen CD3. Although these findings are open to other interpretations, they are consistent with the hypothesis that at least some cases of Hodgkin's disease arise from activated T-cells.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Leiomyosarcoma of the kidney. Immunohistological and ultrastructural findings with special emphasis on the growth fraction.

This report deals with a case of renal smooth muscle tumour. Considering the low mitotic rate, this neoplasm would have been classified as leiomyoma. However, it displayed a relatively large growth fraction by immunostaining with the monoclonal antibody Ki-67. This led us to the diagnosis "leiomyosarcoma", which is in line with the unfavourable clinical course. We suggest that assessment of the growth fraction with Ki-67 seems to be more objective than the conventional criteria for determining the malignant potential of smooth muscle tumours.

Aged↗
PubMed1989

Characterisation of adenoid cystic carcinoma of the breast by immunohistology.

An adenoid cystic carcinoma of the breast in a 78 year old woman was analysed immunohistologically for the production of type IV collagen, the expression of vimentin, epithelial membrane antigen (EMA) and steroid receptors, and the proliferative activity of the tumour cells. The data were compared with those obtained in eight adenoid cystic carcinomas of salivary glands and in ductal carcinomas of the breast with a cribriform growth pattern. The patients' ages were as follows: 45-80 years (mean 63.2) for the salivary gland carcinomas; 37-69 years (mean 50.6) for the ductal breast carcinomas. In contrast to the cribriform spaces of ductal carcinomas, the pseudocysts in adenoid cystic carcinomas were lined by type IV collagen. The opposite pattern was observed for EMA. Like the myoepithelium of normal breast, the myoepithelium-like cells of adenoid cystic carcinoma stained positive for vimentin while the ductular epithelium-like ones did not. All adenoid cystic carcinomas, including that of the breast, were negative for the oestrogen and progesterone receptors, unlike the ductal carcinomas. Proliferative activity of the adenoid cystic carcinoma of the breast was relatively low. These data broaden the range of antibodies suitable for differential diagnosis of both tumour types. They may explain the differences in prognosis, and they explain why hormonal treatment or radiotherapy of adenoid cystic carcinoma of the breast are often ineffectual.

Antigens, Neoplasm↗