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Biomedical subjects

H Feichtinger

Publications and source records attributed to H Feichtinger.

At least 55 records · Page 3Linked to original sources
PubMed1995

Thymic immunopathology and progression of SIVsm infection in cynomolgus monkeys.

Thymuses from 22 cynomolgus monkeys infected with simian immunodeficiency virus (SIVsm) developed characteristic cortical and medullary changes including formation of B-cell follicles (8/21) and accumulation of virus immune complexes. Advanced thymic histopathology was correlated with more pronounced immunodeficiency. SIVsm provirus was detected by polymerase chain reaction (PCR) in most (16/18) thymuses and spliced viral env mRNA in 3 (3/7) thymuses with advanced histopathologic changes indicative of thymic SIVsm replication. By combined in situ hybridization (ISH) and immunohistochemistry, viral RNA was localized mainly to the follicular dendritic network, macrophages, multinucleated giant cells, and lymphocytes of the medullary regions. Latent infection by an Epstein-Barr-related herpesvirus (HVMF1) was also found by PCR and by ISH in medullary regions of three (3 of 8) thymuses with B-cell follicles, suggestive of an inductive role for B-cell proliferation in these thymuses. In a control group of HIV-2-infected nonimmunosuppressed monkeys, no comparable thymic changes were observed. Our results indicate that SIV, and probably by analogy HIV, can have direct and diverse pathogenic effects on the thymus that are important in the development of simian (human) AIDS.

Animals↗
PubMed1995

IL-6 secretion by human peritoneal mesothelial and ovarian cancer cells.

Malignant ascites of epithelial ovarian cancer patients contains high levels of interleukin 6 (IL-6). The present study was conducted to compare the secretion of IL-6 by seven different human ovarian cancer cell lines (OVCA) and cultured human peritoneal mesothelial cells (HPMC) and to examine the regulation of its production by other cytokines. IL-6 was detected in supernatant medium of all mesothelial cell cultures (8/8) and 6/7 ovarian cancer cell lines. Levels of IL-6 secreted by HPMC (median 27,100 pg/1 x 10(5) cells; range 3870-168,200) were 590-fold higher (P < 0.01) than those secreted by OVCA (median 46 pg/1 x 10(5) cells; range 0-16,450). Treatment with TNF-alpha or IL-1 beta (both 10 ng/ml) for both types of cells and both cytokines resulted in a significant (P < 0.05) elevation of IL-6 production. In OVCA IL-6 secretion was increased 7- and 39-fold and in HPMC 6- and 8-fold, respectively. Under TNF-alpha treatment IL-6-levels secreted by HPMC were 149-fold higher (P < 0.01) than those generated by OVCA. Similarly, IL-1 beta-induced IL-6 levels were 102-fold higher in HPMC (median 288,800 pg/1 x 10(5) cells; range 93,125-552,800) than in OVCA. IFN-gamma (10 ng/ml) increased IL-6 generation in OVCA (6-fold) but not HPMC. The proliferation of both cell types however, was significantly (P < 0.05) inhibited by IFN-gamma. Our results suggest that peritoneal mesothelial cells may be a prominent source of IL-6 in ovarian cancer-related ascites.

Ascites↗
PubMed1995

Copper-induced acute rhabdomyolysis in Wilson's disease.

Wilson's disease is a lethal defect in copper metabolism causing a continual increase in tissue copper concentrations that become toxic to the liver, brain, kidney, eye, skeletal system, and several other tissues and organs. The liver is unique among these in being both the site of the etiologic biochemical abnormality and the organ that is always affected by copper toxicosis. Although myocardial muscle involvement has been reported in association with Wilson's disease, copper deposits in peripheral muscle tissue have not yet been described. A case of a young patient with Wilson's disease who developed recurrent episodes of acute rhabdomyolysis is presented, and the accumulation of copper in muscle tissue as a possible complication is discussed.

Acetates↗
PubMed1995

Gastric malt lymphoma with crystalline immunoglobulin inclusions and secondary immunoblastic lymphoma in a cervical lymph node.

A case of gastric B cell lymphoma of the mucosa-associated lymphoid tissue (MALT) with crystalline immunoglobulin inclusions in monotypic plasma cells is reported, which initially presented as a secondary immunoblastic lymphoma in a cervical lymph node. The low-grade MALT lymphoma was diagnosed 14 months after detection of the nodal high-grade lymphoma, but rare crystal-containing plasma cells of identical immunoglobulin isotype found in the immunoblastic lymphoma retrospectively confirmed a common clonal origin. The diagnostic significance of crystalline immunoglobulin inclusions and the unusual initial presentation of MALT lymphoma as a secondary high-grade lymphoma at a distant nodal site are discussed.

Aged↗
PubMed1995

Stereotactic radiosurgery of skull base meningiomas.

Between April 1992 and March 1994, 48 patients with skull base meningiomas were treated at our department. The age of these patients ranged from 10 to 76 years. The male:female ratio was 1:3. Thirty-seven of these patients had primary open surgery for partial removal and subsequent radiosurgical treatment. In 1 patient a recurrent meningioma after so-called total microsurgical removal was treated radiosurgically. Radiosurgery was performed as a primary treatment in 11 patients. The mean tumor volume was 13.7 cm3 (range: 0.8-82 cm3). These tumor volumes could be covered by mean isodose volumes of 44% (range: 30-70%) and were treated by a mean dose of 15 Gy (range: 8-25 Gy) at the tumor border. One patient underwent radiosurgery with a staged treatment protocol with a 4.6-month interval. In 37 patients, a total of 102 follow-up scans were available. The remaining 11 patients have not been included in the postradiosurgical evaluation, since the observation time was either too short or the patients were lost to follow-up. The mean interval between Gamma Knife treatment and the last follow-up scan was 12 months, with a range from 2.3 to 22.7 months. Follow-up imaging (CT, MRI or both) revealed a decreased volume of the tumor in 9 cases (24%). In 25 cases (68%), tumor progression was stopped, and in 3 cases (8%) increased tumor volumes could be observed (2 patients with malignant meningiomas). In 3 cases marked central tumor necrosis was seen. Neurological follow-up examinations (n = 38 patients) showed a stable neurological status in 74%, ameliorated status in 13% and worsening in 13% of the patients.

Adolescent↗
PubMed1995

Prognosis and life expectancy on alpha-1-antitrypsin deficiency and chronic liver disease.

BACKGROUND: Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with early development of emphysema, liver cirrhosis, and hepatocellular carcinoma. The aim of the present study was to define prognosis and life expectancy in patients with alpha 1-antitrypsin deficiency with and without chronic liver disease. METHODS: After a follow-up of 15 years the estimated life table analysis of mortality of 160 patients with alpha 1-antitrypsin deficiency was retrospectively calculated. The survival time was estimated using the Kaplan-Meier survival curves and was compared with the life expectancy of the age- and sex-matched population of west Austria. RESULTS: Fifty-four patients with alpha 1-antitrypsin patients had evidence of chronic liver disease; of these, 78% showed positive viral markers. Of the 106 patients with alpha 1-antitrypsin deficiency without chronic liver disease none had evidence of additional viral infection. Life expectancy in patients with alpha-1 antitrypsin deficiency and chronic liver disease was significantly lower than in patients with alpha 1-antitrypsin deficiency without chronic liver disease (p = 0.001). No difference in life expectancy in alpha 1-antitrypsin deficiency without chronic liver disease was found in comparison with that of the normal population. CONCLUSIONS: We suggest that in alpha 1-antitrypsin deficiency-associated chronic liver disease it is the high coinfection rather than the inborn error of metabolism itself that is responsible for a deterioration of life expectancy or for the poor prognosis of the disease.

Chronic Disease↗
PubMed1995

Rationale and technique of nerve sparing radical cystectomy before an orthotopic neobladder procedure in women.

PURPOSE: We developed refinements in the technique of cystectomy and subsequent intestine to urethra anastomosis to improve postoperative results in women undergoing anterior exenteration and creation of an orthotopic neobladder to the urethra. MATERIALS AND METHODS: Anatomical dissection and microdissection studies were performed on formalin-carbol fixed adult cadavers and correlated with previous anatomical and clinical findings. The resulting surgical variations were performed in 5 carefully selected women undergoing lower urinary tract reconstruction. RESULTS: Optimal postoperative results in regard to continence and voiding without compromising oncological outcome may be obtained by preserving the entire lateral vaginal walls, performing nerve sparing dissection of the bladder neck and proximal urethra, removing 1 cm. proximal urethra en bloc with the cystectomy specimen and using additional attachments of the anastomosed intestinal pouch to surrounding pelvic structures. Patients achieved day and night continence after 6 months, mean pouch volume was 580 cc (range 450 to 750) and residual volumes ranged from 0 to 150 cc. No tumor recurred after 6 to 17 months. CONCLUSIONS: Refinements in the technique of radical cystectomy and orthotopic neobladder to the urethra in women may improve continence and spontaneous voiding without compromising surgical oncological outcome, and they further justify orthotopic diversion in select women with bladder cancer.

Aged↗
PubMed1995

Testicular seminomas are aneuploid tumors.

BACKGROUND: Distinct ploidy patterns of germ cell tumors and aneuploidy of classic seminoma are of central importance in a current concept designating seminoma as a stage in tumor evolution preceding all nonseminomatous germ cell tumors. Whereas cytogenetic studies almost constantly revealed numerical chromosomal aberrations in seminomas in line with this pathogenetic model, ploidy determination by DNA cytometry yielded highly controversial results on the frequency of diploid seminomas. EXPERIMENTAL DESIGN: Twenty-two classic seminomas were investigated in a comparative manner by DNA flow and DNA image cytometry on nuclei isolated from fresh as well as formalin-fixed tumors. The cellular composition of the tumors, i.e., the number of neoplastic, interstitial, and lymphoid cells was quantified in each case. RESULTS: Irrespective of the tissue preparation and fixation method, all of the tumors that were analyzed were aneuploid by image cytometry. Diploid cases were only found by flow cytometry. Thus, 1/22 cases from paraffin-embedded and 4/11 cases of native tumors showed a single diploid stemline by flow cytometry, however, they exhibited aneuploidy by image cytometry. The quantity of tumor infiltrating lymphocytes was clearly correlated with false diploidy detected by flow cytometry. CONCLUSIONS: Classic testicular seminomas are aneuploid tumors. Previous reports on diploid cases detected by flow cytometry have most likely been caused by extensive lymphocytic infiltration.

Aneuploidy↗
PubMed1994

Carcinoma in situ of the testis detected by DNA flow cytometry of testicular fine-needle aspirates.

Testicular carcinoma in situ (CIS) is usually diagnosed histologically on surgical biopsies. The present study was performed to test an alternative approach--DNA flow cytometry (FCM) of testicular fine-needle aspirates (FNA)--for the detection of this lesion. FNAs from 18 cases of testicular germ cell tumors (TGCT) and tumor adjacent parenchyma were analysed by DNA FCM. DNA histograms of all cell nuclei and histograms representing selectively the hyperdiploid compartment were analysed. The presence and extention of CIS were determined by histology and immunohistochemistry. In 16 of 18 cases, CIS was histologically present, whereas aneuploid peaks were detected in only 11 cases in DNA histograms of all cell nuclei. In the analysis of the histograms of the hyperdiploid region, 4 additional cases of CIS could be identified increasing the sensitivity to 15/16 cases (93.8%). In all but one case, the DNA indices of CIS and invasive tumors were identical. The study demonstrates that DNA FCM of testicular FNAs using the described data acquisition and analysis could also be applicable for detection of CIS in a clinical situation.

Aneuploidy↗
PubMed1994

In vitro investigations of interphase and metaphase argyrophilic nucleolar organizer regions and cellular proliferation in the human urothelial cancer cell line HOK-1.

Detailed investigation of cell growth and nucleolar organizer region associated argyrophilic proteins (Ag-NORs) is necessary to assess a possible impact of Ag-NOR quantification on the diagnosis and prognosis of tumours. In this study, cellular proliferation of the transitional-cell carcinoma cell line HOK-1 was modulated over a period of 11 days by starvation and subsequent medium addition. Proliferation was determined daily by DNA flow cytometric estimation of S-phase fraction (SPF) and mitotic index (MI) calculation. The number and area of interphase Ag-NORs were quantified by automated image analysis daily and the number of Ag-NOR bearing chromosomes in metaphase was counted. In interphase nuclei, Ag-NOR area showed a highly significant correlation with SPF (p < 0.0001) whereas interphase Ag-NOR number showed significant correlation with MI (p < 0.05). A positive relationship between the number of Ag-NOR bearing chromosomes in metaphases and cellular proliferation was also observed. There is variability in Ag-NOR quantity during interphase and metaphase depending on growth conditions in vitro. Correlations of the number of interphase Ag-NORs with the MI on one hand and Ag-NOR area with SPF on the other provide further evidence that distribution and quantity of Ag-NORs are strongly influenced by the cell cycle phase within the structural-functional unit of the nucleolus.

Carcinoma, Transitional Cell↗
PubMed1994

Quantification of spermatogenesis by dual-parameter flow cytometry.

OBJECTIVE: To investigate the usefulness of dual-parameter flow cytometry of testicular fine-needle aspirates for the quantification of spermatogenesis. Immunofluorescence staining for vimentin was introduced to discriminate vimentin-negative germ cells from vimentin-positive stromal cells. The results of flow cytometry were compared with testicular morphology and immunohistochemistry in cases of regular and disturbed germ cell maturation. DESIGN: Testicular fine-needle aspiration and surgical biopsy were performed in 50 autopsy cases. The fine-needle aspirates were double stained for the intermediate filament vimentin by indirect immunofluorescence and DNA propidium iodide and analyzed by flow cytometry. Surgical biopsies were examined by light microscopy. The distribution of vimentin-positive cells was evaluated by immunohistochemistry. RESULTS: A comparison of morphology and flow cytometric analysis yielded characteristic quantitative distribution patterns of the different germ cell and somatic cell populations in regular and disturbed spermatogenesis. All three ploidy compartments of the germ epithelium correlated with high statistical significance with the respective histologic diagnoses. Moreover, a marked quantitative increase of stromal cells could be demonstrated in spermatogenetic disorders. CONCLUSIONS: The simultaneous analysis of the cellular DNA content and the intermediate filament vimentin by flow cytometry enables a detailed investigation of spermatogenetic disorders. Quantitative changes of the relationships between germ cells and somatic cells can be selectively investigated.

Biopsy, Needle↗
PubMed1993

Expression of Epstein-Barr-virus-related nuclear antigens and B-cell markers in lymphomas of SIV-immunosuppressed monkeys.

Simian-immunodeficiency-virus(SIV)-infected cynomolgus monkeys develop B-cell lymphomas in approximately one third of the cases. We have now studied the expression of cynomolgus-Epstein-Barr-virus(cyno-EBV) nuclear antigens in 13 cyno-EBV-carrying SIVsm-associated monkey lymphomas and established cell lines from 3 of these tumors. Immunoblots of cell lysates were probed with polyspecific and monospecific reagents directed against human EB-virus EBNAI-6, and against the membrane protein LMPI. An EBNA2-cross-reacting protein was demonstrated in 8 lymphoma tissues (8/13) and in the 3 cell lines derived from the tumors. All tumors expressed a polypeptide with 50 to 55 kDa molecular weight, which cross-reacted with some antibodies to EBNAI. Absorption experiments with normal monkey tissue showed that this polypeptide was specific for the cyno-EBV-carrying lymphoma cells. Equivalents of EBNA3-6 and LMPI could not be detected. Immunophenotypical characterization showed that the monkey lymphomas were similar to human HIV-associated B-cell lymphomas. Malignant B-cell lymphomas in experimentally SIVsm-infected cynomolgus monkeys can be a model for EBV-associated lymphomagenesis in immunodeficiency states.

Animals↗
PubMed1993

Interaction of human malignant melanoma tumor spheroids with endothelium and reconstituted basement membrane: modulation by RGDS.

Tumor-cell extravasation involves sequential adhesive interactions with vascular endothelium and the subendothelial basement membrane. We have established a 3-dimensional model in vitro to simulate these events and to elucidate targets of the anti-cell-adhesive synthetic peptide RGDS. Tumor spheroids of the melanoma cell line ST-ML-12 served as models of tumor-cell emboli and were transferred onto human umbilical vein endothelial cells. To imitate the vascular anatomy, the latter were grown on reconstituted basement membranes produced by dextran-stimulated bovine corneal endothelial cells. RGDS did not affect the homotypic aggregation of the tumor cells and only minimally inhibited the attachment of the spheroids to the reconstituted vessel. A short-term (20 min) inhibition of adhesion to denuded basement membranes was observed. The attachment was closely associated with damage to the endothelial cells by oxygen-derived free radicals. RGDS retarded endothelial injury for up to 3 hr. The most prominent effect was observed after penetration of the endothelium. RGDS suppressed the emigration of tumor cells from the attached tumor-cell cluster in a dose- and time-dependent fashion. After 12 hr, the inhibitory effect progressively declined. This was not due to loss of activity of the peptide, indicating a resistance mechanism in the melanoma cells. On purified components of the basement membrane, RGDS effectively inhibited the initial spheroid attachment to fibronectin and collagen IV but had no effect on attachment to laminin. By contrast, subsequent migration was significantly suppressed on all substrata. Our model permits the study of dynamic cell-cell and cell-extracellular-matrix interactions and indicates that RGDS might predominantly act on early tumor-cell locomotion after penetration of the endothelium.

Basement Membrane↗
PubMed1993

[Proliferative activity and p53 expression in transitional cell carcinoma of the urinary bladder].

Mutations of the p53 gene are important mechanisms in malignant transformation and are associated with dysregulation of normal cell growth. In the present study the expression of mutated p53-protein and proliferating cell nuclear antigen (PCNA) was investigated in a series of 31 human transitional cell carcinomas (TCC) by immunohistochemistry (IHC). The number of PCNA-positive cells and the pattern of expression was distinct in normal urothelium being confined to the basal cell layer. In dysplastic urothelium and in Carcinoma in situ (CIS) PCNA-immunoreactive nuclei were irregularly distributed throughout all layers. In tumor cell complexes the pattern of PCNA-immunoreactivity was different in papillary and primary infiltrating TCCs. Densitometric quantification of the intensity of the PCNA-reactivity using image analysis revealed an increase from normal to dysplastic urothelium and from dysplastic urothelium to invasive tumors. 21/31 (68%) of the tumors and tumor-associated CIS showed overexpression of p53 varying in percentage, pattern and reaction intensity. The percentage of PCNA-positive cells was higher in tumors overexpressing p53. Double IHC showed colocalization of both molecules in a significant proportion of tumor cells suggesting a link of p53 overexpression and the abnormal proliferative activity. The present results show that p53 over-expression is found in a significant percentage of TCCs and indicate a close association with a defective growth regulation resulting in increased PCNA-levels and enhanced cellular proliferation.

Analysis of Variance↗
PubMed1993

Immunohistochemical distribution of leucocyte antigens in lymphoid tissues of cynomolgus monkeys (Macaca fascicularis).

Crossreactivity of antibodies to human leucocyte antigens with lymphoid tissues of cynomolgus monkeys was studied by immunohistochemistry and immunoblotting. Of a total of 54 clusters of differentiation (CD) antigens, 39 were expressed essentially with the same immunostaining patterns in the monkey as in human lymphoid tissues. By immunoblotting L26 (CD20) detected a 35 Kd molecule in the monkey lymph node. Our observations indicated that most of the CD antigens are expressed and can be studied in lymphoid tissues of cynomolgus monkeys.

Animals↗
PubMed1992

A monkey model for Epstein Barr virus-associated lymphomagenesis in human acquired immunodeficiency syndrome.

High-grade malignant nonHodgkin's lymphomas--five lymphoblastic, three pleomorphic, and two immunoblastic--developed in 10/25 cynomolgus monkeys (Macaca fascicularis) followed for up to 746 d after infection with simian immunodeficiency virus, strain SIVsm. These lymphomas were shown to be associated with an Epstein-Barr (EB)-like cynomolgus B-lymphotropic herpesvirus (CBLV) by electron microscopy, by Southern blot hybridization with probes against human EBV, and by the expression of antigens corresponding to EBV-associated nuclear antigens (EBNAs) involved in human B cells transformation. Southern blot demonstration of immunoglobulin gene rearrangements and homogeneous EBV episomes indicated that all the lymphomas were CBLV-associated monoclonal B cell proliferations. Our findings suggest that these tumors correspond to the EBV-associated malignant lymphomas in acquired immunodeficiency syndrome with respect to clinical, morphological, phenotypic, and genotypic characteristics. The particular susceptibility of SIVsm immunodeficient cynomolgus monkeys for CBLV-associated lymphomagenesis appears therefore a useful model for EBV-associated lymphomas in humans.

Animals↗