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H Feichtinger

Publications and source records attributed to H Feichtinger.

At least 73 records · Page 4Linked to original sources
PubMed1992

Deoxyribonucleic acid flow cytometry and semiquantitative histology of spermatogenesis: a comparative study.

OBJECTIVE: To compare deoxyribonucleic acid (DNA) flow cytometry with a semiquantitative histologic method for the assessment of spermatogenesis and to investigate the influence of various preparative techniques on the results of DNA measurements. DESIGN: Testicular tissue from 52 autopsies was examined for spermatogenesis by DNA flow cytometry and by conventional semiquantitative histology. Flow cytometry was performed on single nuclei suspensions from fine needle aspiration biopsies, resuspended imprints, as well as on specimens obtained by mechanical disaggregation of surgical biopsies of the same testis. RESULTS: In all cases, flow cytometry revealed a characteristic distribution pattern of haploid (n), diploid (2n), and tetraploid (4n) cells independent of the preparation technique used. The percentage of haploid cells of the testes showed statistically highly significant correlations (P = 0.0002) with the results of semiquantitative histology. Fine needle aspiration biopsy always contained more haploid cells compared with resuspended imprints and mechanically disaggregated samples. CONCLUSION: Our results confirm the suitability of DNA flow cytometry as a fast and reliable quantitative method for the assessment of spermatogenesis and demonstrate its optimal feasibility in combination with fine needle aspiration biopsy.

Adult↗
PubMed1992

Malignant lymphoma associated with human AIDS and with SIV-induced immunodeficiency in macaques.

Malignant lymphomas associated with human (HIV) and simian (SIV) immunodeficiency virus infections are reviewed and compared. Recent observation of a high frequency of lymphomas in a series of cynomolgus macaques, highly immunodeficient after infection with SIVsm(smm3) are described. In addition to the increased frequency in human and monkey AIDS, SIV and HIV lymphomas share several important features. Clinically and by histology they present as aggressive high-grade malignant tumors with a predilection for extranodal growth in viscera, skin, central nervous system, testis, and retroorbitally. Most malignant lymphomas are of B-cell origin. AIDS lymphomas in humans are heterogeneous with regard to Epstein-Barr virus (EBV) association. Similarly, most lymphomas in monkeys experimentally infected with SIV tested to date were shown to be associated with an EBV-like simian herpes virus. These observations point to the possibility of using SIV-immunodeficient macaques for study of EBV and other oncogenic and immunosuppressive factors in AIDS-associated lymphomagenesis.

AIDS-Related Complex↗
PubMed1992

[Opportunistic malignant lymphomas in SIV infected primates--a model for Epstein-Barr virus associated lymphomas in AIDS].

In a series of 33 cynomolgus monkeys (Macaca fascicularis) experimentally infected with Simian Immunodeficiency virus (SIV), strain smm3, 13 animals developed malignant Non-Hodgkin lymphomas. These lymphomas presented with unusual primary manifestations like in the orbita, testes, and brain. The morphological features and immunophenotyping identified the tumors as high malignant B-cell lymphomas. In all tumors as well as in tumor-derived cell lines a cynomolgus B-lymphotropic herpes virus (CBLV) with structural homogeneity to the Epstein-Barr virus (EBV) could be demonstrated by Southern blotting with EBV-specific probes. The lymphoma cells also expressed CBLV-associated nuclear antigens involved in B-cell transformation crossreacting with EBNA-specific human sera and monoclonal antibodies. Ig-gene rearrangement studies revealed clonal populations, however, no translocations of the c-myc oncogene could be detected. The lymphomas developing with high frequency in SIV-induced immunodeficiency resemble a major subtype of human EBV-associated AIDS lymphomas. This animal model can therefore be used to further elucidate interactions of HIV and EBV in AIDS-related lymphomagenesis.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Molecular genetic analysis of DNA obtained from fixed, air dried or paraffin embedded sources.

In the present study methods are described for the analysis of the genomic structure of DNA isolated from tissues that have been stored up to several years as air-dried or stained bone marrow smears, bone marrow biopsies in "Histicon", chromosomal preparations in fixative or as formalin fixed tissues embedded in paraffin. By application of the new techniques clonal B- and T-cell disorders, Philadelphia chromosome translocations and ras oncogene mutations in pancreatic carcinomas could be detected. Thus, these DNA extraction procedures may open new avenues to pathological archives and enable the analysis of samples when fresh material is not available.

Bone Marrow↗
PubMed1991

Gene rearrangement studies in the diagnosis of primary systemic and nodular primary localized cutaneous amyloidosis.

Difficulties may arise in the diagnosis of patients with clinical features suggestive of plasma cell dyscrasia-related amyloidosis (amyloidosis L), but without evidence of a paraprotein. We have employed gene rearrangement methodology to demonstrate the clonality of bone marrow cells not only in a patient with myeloma-associated systemic amyloidosis, but also in a patient with "primary" systemic amyloidosis without overt myeloma or a detectable paraprotein. Furthermore, we have shown the clonality of the amyloid-producing plasma cells within a skin nodule of a patient with primary localized cutaneous amyloidosis; by contrast, clonal rearrangement was not detected in bone marrow cells from this patient. This finding provides definitive proof that organ-limited nodular primary localized cutaneous amyloid deposits arise in relation to cutaneous plasmacytomas. Gene rearrangement studies may enable early diagnosis and initiation of treatment in patients with systemic amyloidosis L, as well as their differentiation from patients with organ-limited nodular cutaneous amyloidosis, who do not require aggressive therapy.

Aged↗
PubMed1990

Two G protein oncogenes in human endocrine tumors.

Somatic mutations in a subset of growth hormone (GH)-secreting pituitary tumors convert the gene for the alpha polypeptide chain (alpha s) of Gs into a putative oncogene, termed gsp. These mutations, which activate alpha s by inhibiting its guanosine triphosphatase (GTPase) activity, are found in codons for either of two amino acids, each of which is completely conserved in all known G protein alpha chains. The likelihood that similar mutations would activate other G proteins prompted a survey of human tumors for mutations that replace either of these two amino acids in other G protein alpha chain genes. The first gene so far tested, which encodes the alpha chain of Gi2, showed mutations that replaced arginine-179 with either cysteine or histidine in 3 of 11 tumors of the adrenal cortex and 3 of 10 endocrine tumors of the ovary. The mutant alpha i2 gene is a putative oncogene, referred to as gip2. In addition, gsp mutations were found in 18 of 42 GH-secreting pituitary tumors and in an autonomously functioning thyroid adenoma. These findings suggest that human tumors may harbor oncogenic mutations in various G protein alpha chain genes.

Amino Acid Sequence↗
PubMed1990

Malignant hemangioendothelioma of the thyroid. Its immunohistochemical discrimination from undifferentiated thyroid carcinoma.

Eighteen cases of malignant hemangioendothelioma (MHE) of the thyroid and 16 cases of undifferentiated thyroid carcinoma were investigated immunohistochemically with antibodies against endothelial cell specific markers (factor VIII-related antigen, BMA 120, blood group isoantigens, Ulex europaeus agglutinin I), thyroglobulin, and the intermediate filament proteins vimentin and cytokeratin. All MHE were positive for factor VIII-related antigen and vimentin, in 14 of 18 cases for BMA 120, and in 9 of 18 cases for U. europaeus. All other markers were negative in MHE. Endothelial cell specific markers were commonly negative in undifferentiated carcinomas with one exception (one case was moderately positive for U. europaeus). Twelve of 16 undifferentiated carcinomas showed vimentin positivity, and 8 of 16 showed cytokeratin positivity. Four cases showed a vimentin/cytokeratin coexpression. It is concluded that the endothelial origin of MHE can be shown by certain endothelial cell markers in almost all cases.

Adult↗
PubMed1990

Malignant lymphomas in cynomolgus monkeys infected with simian immunodeficiency virus.

Malignant lymphomas were observed in 38% (9 of 24) of simian immunodeficiency virus (SIV)-infected cynomolgus monkeys (Macaca fascicularis) 5 to 15 months after inoculation with SIV strain SMM3. Lymphomagenesis in the SIV-infected monkeys was not related directly to the SIV-infectious dose given. All SIV-infected animals developed severe immunodeficiency. No significant difference in immunodeficiency was observed between tumor-bearing and non-tumor-bearing animals. In contrast, no lymphomas were observed in a comparable group of HIV-2-infected monkeys, which did not develop immunodeficiency; nor did the noninfected control monkeys. All 9 SIV-related tumors were high-grade B-cell lymphoblastic or pleomorphic lymphomas with extranodal, disseminated growth. Most tumors showed marked infiltration by monocytes and CD8+ T lymphocytes. Occasional tumor infiltrating cells showed immunohistochemical reaction for SIV. The cells of two tumors were established in vitro and shown to be of B-cell phenotype. The tumor cell cultures showed no reverse transcriptase activity and no evidence of virus infection by electron microscopy. Our observations indicate that SIV-induced immunodeficiency in cynomolgus monkeys also mimics HIV infection and AIDS in humans with regard to increased lymphomagenesis and type of lymphomas.

Animals↗
PubMed1989

High frequency of Ki-ras codon 12 mutations in pancreatic adenocarcinomas.

The frequency of Ki-ras gene mutations was studied in 100 paraffin-embedded sections obtained from 63 pancreatic adenocarcinomas by in vitro amplification of target sequences via polymerase chain reaction (PCR) and selective oligonucleotide hybridization. Forty-seven (75%) of the tumors contained a Ki-ras mutation at codon 12. No predominant amino acid substitution or nucleotide transition at this codon was observed. Two carcinomas exhibited 2 distinct Ki-ras mutations. No particular correlation could be established between the incidence of Ki-ras mutation and clinical parameters (sex, age, survival), tumor grade or tumor stage.

Adenocarcinoma↗
PubMed1989

Expression of 7F7-antigen, a human adhesion molecule identical to intercellular adhesion molecule-1 (ICAM-1) in human carcinomas and their stromal fibroblasts.

The 7F7-antigen is a widespread 85-kDa membrane adherence molecule involved in heterotypic adhesion between PHA-blasts and fibroblasts. Immunofluorescence analysis of COS cells transfected with clone pICAM-I indicated that 7F7-antigen is identical with ICAM-I, the ligand for the contact molecule LFA-I. We have investigated the expression of ICAM-I on several human carcinomas. Tumor cells in most carcinomas, with the exception of squamous-cell carcinomas, expressed very little ICAM-I or none at all. In contrast, marked expression of this molecule was observed on fibrous tissue in the vicinity of carcinoma cells, its intensity correlating with lymphatic infiltration in these tumors. We also examined the expression of ICAM-I on carcinoma cell lines and its induction by treatment with interferon-gamma (IFN-gamma). The inducibility of ICAM-I expression on cultured fibroblasts by several lymphokines suggests that the expression of ICAM-I in the vicinity of carcinoma cells is effected by lymphokines produced by activated lymphocytes/macrophages within the tumor.

Antigens, Surface↗
PubMed1989

Frequency of medullary thyroid carcinoma in an endemic goiter area.

A series of 41 poorly differentiated follicular carcinomas of the thyroid gland without histopathological features of medullary or papillary carcinoma and 9 cases of undifferentiated thyroid carcinoma of the small cell type (diagnosed between 1967 and 1983) were investigated immunohistochemically. Two poorly differentiated follicular carcinomas showed a considerable number of calcitonin-positive cells in addition to the weakly thyroglobulin-positive tumor cells. One of these cases revealed several areas with calcitonin-positive tumor cells with additional squamous metaplasia with keratinization. No medullary carcinomas could be demonstrated among the 9 cases previously diagnosed as undifferentiated thyroid carcinomas of the small cell type. From the epidemiological point of view the application of immunohistochemistry does not significantly increase the proportion of medullary carcinomas detected in our endemic goiter area. The incidence of medullary carcinoma remains surprisingly low when compared with nonendemic areas.

Adenocarcinoma↗
PubMed1988

Synchronous adenocarcinoma of the transverse colon, the gallbladder and the vermiform appendix.

According to the literature synchronous adenocarcinomas of both, the colon and the gallbladder or the colon and the appendix are extremely unusual. To our knowledge the simultaneous occurrence of all three tumors has never been published before. Preoperative diagnosis of early stage tumors of the gallbladder and the vermiform appendix is also made very seldom. The following case report records an instance of synchronous adenocarcinomas of the gallbladder, the transverse colon, in a colonic polyp and the appendix. Owing to the patient's advanced age simultane cancer occurrence may be mere coincidence. Nevertheless, this extremely rare entity could also be ascribed to a genetic defect or an unknown carcinogenic agent.

Adenocarcinoma↗
PubMed1988

Importance of an 85 kDa membrane glycoprotein for a variety of cell-cell interactions.

The membrane molecule termed "7F7-antigen" has been found to be involved in several examples of cell-cell interactions. This 85 kDa glycoprotein with a protein core of about 55 kDa contains N-linked and O-linked carbohydrates. It has an isoelectric point of 8.0-8.5 and is expressed on 20% of peripheral blood mononuclear cells, 35% of peripheral blood B-cells, follicular dendritic cells and vascular endothelium. It is also expressed on activated T-cells and its expression on B-cells, fibroblasts and monocytes increases after treatment with PWM, interferon-gamma and after three days culture, respectively. The MAb 7F7 used to define this antigen inhibits the initiation of T-cell proliferation induced by anti-CD3, PHA, ConA and (weakly) allogenic stimulator cells, but does not affect the growth of IL-2 dependent T-cells and does not interfere with the killing of PHA-blasts by allogenic IL-2 dependent T-cells. 7F7 also inhibits the binding of C3-coated sheep erythrocytes to B-cells, the PMA-induced aggregation of U937 and the binding of activated T-cells to fibroblasts. The 7F7-antigen is expressed on some non-Hodgkin lymphomas of B-cell differentiation, particularly those with follicular structure, but not on Burkitt's lymphoma, ALL or carcinomas of various tissues. It is, however, found on fibrous tissue surrounding infiltrating carcinoma cells. The expression of a melanoma antigen, P3.58, which was shown to be identical to 7F7-antigen correlates with stage and spread of invasive melanoma. It was concluded that the 7F7-antigen, which is probably related to a previously described adherence molecule (ICAM-1), is of biological importance for the initiation of T-cell responses. With the possible exception of melanoma its expression on neoplastic cells in vivo is unlikely to be of importance for the spread of malignant disease.

Antigens, Neoplasm↗
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↗