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A Gschwendtner

Publications and source records attributed to A Gschwendtner.

At least 37 records · Page 2Linked to original sources
PubMed1999

Mean weighted nuclear volumes in colonic adenocarcinomas. Evaluation of prognostic significance.

OBJECTIVE: To investigate the correlation of stereologically estimated mean weighted nuclear volumes of tumor cell nuclei (MWNV) with other prognostic factors and survival in colonic adenocarcinomas. STUDY DESIGN: The study group consisted of 42 patients with colonic adenocarcinomas who were treated by a standardized protocol and had a mean follow-up of 89 months. The point sample intercepts method was used to estimate MWNV. In addition, immunohistochemical expression of p53 and Ki-67 was evaluated semiquantitatively. RESULTS: The calculated nuclear volumes correlated significantly with histologic grading and with the extent of tumor progression (organ confined/nonorgan confined). There was no correlation with p53 expression or proliferative activity determined by MIB-1 positivity. No correlation could be demonstrated with sex, age or clinical outcome of the patients. CONCLUSION: Assessment of MWNV in colonic adenocarcinomas does not provide additional information concerning the clinical course.

Adenocarcinoma↗
PubMed1998

Ploidy determination in prostatic adenocarcinoma using thin histological sections: a more sensitive way of detecting aneuploid tumor clones.

BACKGROUND: The aim of this study was to compare the results of DNA image cytometry using single-cell preparations to measurements on thin histological slides of the same tumor block, in order to find the most sensitive way for detecting aneuploidy. METHODS: Twenty-three cases of prostatic adenocarcinoma were investigated by image cytometry to assess the DNA content of tumor cell nuclei. The histograms obtained by section measurements were corrected using the algorithms of Haroske et al. [Zentralbl Pathol 139: 407-417, 1994] and McCready and Papadimitriou [Anal Quant Cytol 5:117-123, 1983]. The basis for recalculation was an exact determination of the thickness of the sections used. RESULTS: Out of the 23 cases investigated, 10 tumors were diploid in the single-cell preparations, whereas 13 were classified as nondiploid. After tissue section measurements and mathematical correction of the histograms, five originally diploid histograms showed an additional aneuploid stem line. This was also the case in 8 of the 13 originally aneuploid cases. CONCLUSIONS: Tissue section measurements turned out to be more sensitive in detecting aneuploid tumor cell populations compared to measurements of cytospins of disintegrated tissue. As aneuploidy provides important prognostic information, this more sensitive means of ploidy determination could be of use in prostatic adenocarcinoma, and should especially be used in cases showing diploid histograms in single-cell cytometry.

Adenocarcinoma↗
PubMed1998

Pathologists' attitudes to implementing telepathology.

If pathologists will benefit so much from using telepathology, why is it taking so long to be introduced? This question has been discussed between experts, but the potential users are rarely asked for their opinions. A questionnaire was sent to the 256 members of the Austrian Society of Pathology; this addressed general aspects of telemedicine, telepathology in frozen-section services and expert consultation, videoconferencing technologies, teleteaching and teletraining. The response rate was 46%. In general, the pathologists thought that telemedicine could become valuable in their daily routine. However, pathologists were most afraid of sampling errors in remote diagnosis and would not readily accept an alternative to the conventional method of looking at a sample. This is only possible using realtime, remotely controlled microscopes. Telepathology systems providing only still images would not be acceptable to most respondents. There was interest in the use of videoconferencing for clinicopathological conferences. Teleteaching and teletraining were seen as welcome additional techniques, but were nevertheless judged unable to replace classical methods of teaching and training.

Attitude of Health Personnel↗
PubMed1998

Primary intestinal non-Hodgkin's lymphoma and Epstein-Barr virus: high frequency of EBV-infection in T-cell lymphomas of Mexican origin.

Epstein-Barr virus is universally associated with endemic Burkitt's lymphoma (BL) and undifferentiated nasopharyngeal carcinoma and can be detected in a significant proportion of cases of Hodgkin's disease (HD) and peripheral T-cell lymphoma, but only rarely in sporadic B-NHL. The frequency of EBV-positivity in certain neoplasms shows important geographic variations. Both HD and sporadic BL from Latin America have shown higher rates of EBV-association than cases from Western countries. In T-NHL, the frequency of EBV-positivity is influenced by the site of the primary tumor and the phenotype of the neoplastic cells. Nasal and nasal-type T-NHL, which show a T/NK-cell phenotype with expression of CD56 are virtually always EBV-associated, whereas only a proportion of nodal, gastrointestinal and pulmonary T-NHL are EBV-infected. A recent investigation of primary intestinal lymphomas of Mexican origin demonstrated EBV-positivity in all examined cases of T-NHL and BL and a proportion of other B-NHLs. The presence of EBV was independent of the presence or absence of enteropathy. Two of 6 cases studied showed CD56 expression. The high rate of EBV-positivity independent of histologic subtype is in contrast to the low to intermediate rates of EBV-positivity found in cases of intestinal T-NHL from Western countries and indicates that geographic differences in the frequency of EBV-association of lymphoid neoplasms might also extend to a fraction of peripheral T-cell lymphomas.

Burkitt Lymphoma↗
PubMed1998

DNA ploidy determination of early molar pregnancies by image analysis: comparison to histologic classification.

BACKGROUND: To improve histologic diagnosis of molar pregnancies, updated guidelines have been proposed recently. These guidelines take into account that less developed molar gestations differ from their fully developed counterparts. OBJECTIVE: To test the validity of these criteria by correlating histologic diagnosis with ploidy determination accomplished by means of image analysis. DESIGN: Fifty archival cases of early molar pregnancy were reclassified according to the new criteria. The diagnosis had to be changed from partial to complete hydatidiform mole (PM to CM, respectively) in 9 cases and from CM to PM in 4 cases. DNA image cytometry could be performed in 40 cases (CM, n = 21; PM, n = 19). RESULTS: There was 100% agreement between histologic diagnosis and a diploid or polyploid histogram in CM and 79% agreement between triploidy and PM, when the updated diagnostic criteria were used. This represents an improvement compared with diagnoses made with former criteria. Nevertheless, problems of correct classification remain: In 3 cases classified as PMs, fetal remnants were accompanied by the histologic appearance of a CM. These 3 cases could represent either a true embryonic development in CM or a twin gestation with one normal pregnancy and one mole, or they could belong to a (very rare) third type of mole. All of them show the same risk of persistent trophoblastic disease observed in classic CM. CONCLUSIONS: As the groups at risk for developing persistent trophoblastic disease can be identified by their DNA histograms, ploidy analysis would be desirable in addition to histologic examination.

Adult↗
PubMed1997

Primary non-Hodgkin's lymphoma of the intestine: high prevalence of Epstein-Barr virus in Mexican lymphomas as compared with European cases.

Recent studies in Western European populations have shown that peripheral T-cell non-Hodgkin's lymphomas (T-NHLs) are associated with Epstein-Barr virus (EBV) in a higher percentage than sporadic B-cell NHL (B-NHLs), and that the frequency of EBV-positivity might be influenced by the primary site of the tumor. Because of the geographic differences in EBV expression in Burkitt's lymphoma (BL) and Hodgkin's disease (HD), and the lack of studies of sporadic NHL from developing countries, we decided to survey the presence of EBV in a series of primary intestinal lymphomas from patients in Mexico and in Western Europe, and to analyze whether EBV status is influenced by tumor phenotype, and geographic or ethnic determinants. Paraffin-embedded tissue from 43 primary intestinal NHLs (19 cases from Mexico and 24 from Western Europe) were examined, including 17 high grade B-NHLs, 9 low grade B-NHLs, and 17 T-NHLs; 6 of which were enteropathy associated T-cell lymphomas. The distribution of histologic subtypes was similar in both groups. The presence of EBV was investigated with a combined approach using a nested polymerase chain reaction technique as well as immunohistochemistry for latent membrane protein-1 and in situ hybridization for EBV early RNA transcripts (EBER 1/2) RNAs. The median age of the Mexican patients was significantly lower than the median age of the European patients (32 v 62 years). This difference was most pronounced in patients with T-cell lymphoma (24 v 63 years). EBER-positive tumor cells were detected in 13 of the 43 (30%) cases of primary intestinal lymphoma, including 5 of 26 sporadic B-NHL (3 high grade and 2 low grade), and 8 of 17 T-NHL, all of which were classified as pleomorphic, medium and large cell. The rates of EBV-positivity were markedly different for European and Mexican cases. Whereas 7 of 7 (100%) T-NHL and 5 of 12 (42%) sporadic B-NHL of Mexican origin were EBER-positive, only 1 of 10 T-NHL and 0 of 14 sporadic B-NHL from Europe showed EBER expression in tumor cells. Latent membrane protein was positive in only 2 of 43 cases, 1 of which was an EBER-negative high grade B-NHL from Mexico that showed intact total mRNA in control hybridization. CD30 expression was found in 4 of 8 EBV-positive T-NHL and in none of the EBV-positive B-NHL. In contrast to European cases, intestinal NHLs from Mexico show a very high frequency of EBV-positivity, which is not limited to T-NHL, but includes a significant proportion of B-NHL. This study strongly suggests that similar to HD and probably BL, there are important epidemiologic differences in EBV association in intestinal T-cell NHL between European and Mexican populations. These differences might be the result of environmental factors, for example, earlier contact with childhood viruses on intestinal lymphomagenesis.

Adolescent↗
PubMed1997

Hydranencephaly with renal dysgenesis: a coincidental finding? Case report with review of the literature.

We present the case of a female fetus aborted in the 20th week of gestation due to severely dysplastic kidneys, anhydramnios and hydranencephalus. The combination of these malformations is extremely rare, resulting in only 4 cases described so far. Our case is the first ever presented in a female showing polycystic-dysplastic kidneys. Multiple multinucleated neurons were a remarkable finding in the remnants of the brain. The possibility of an underlying genetic disorder is discussed, together with a brief review of the literature to date.

Abortion, Induced↗
PubMed1997

The legal situation of telemedicine in Austria.

Searches were conducted of two legal databases dealing with civil law in Austria. The searches produced 12 references relevant to telemedicine, which were obtained from a university legal library. From the literature, it can be concluded that Austrian civil regulations are sufficient to clarify the questions of liability arising in connection with the practice of telemedicine. Although no specific legislation has been enacted as yet, we would not expect such legislation to produce different results in the legal assessment of the case patterns discussed in this paper.

Austria↗
PubMed1997

What do students think about telemedicine?

A questionnaire was distributed to 300 medical students attending a conference in 1996. The return rate was 32%. The majority of students believed that telemedicine will become very important in future. About a quarter of students had had practical experience of telemedicine in a hospital. More than 75% of the respondents said that they would attend telemedicine lectures if they were offered by their university. There were no major concerns among medical students about telematics and its applications in medicine. There was a clear need for more information, which suggests that universities should offer special lectures and practical courses in telemedicine. The interest of students in tele-learning was very high. This interest would justify more attempts to introduce tele-learning by the universities.

Attitude of Health Personnel↗
PubMed1997

DNA measurement on histologic slides. Does it work on human tissue?

OBJECTIVE: To determine the performance of different mathematical methods of correcting histograms obtained by densitometric DNA measurement on thin tissue sections for cutting artifacts in different types of human tissue. STUDY DESIGN: The study group consisted of four different euploid-polyploidizing, nonmalignant human tissues (liver, breast cyst with apocrine metaplasia, adenoma of the thyroid, condyloma). The section thickness was accurately measured. The algorithms of Bins, McCready, Bacus and Haroske were applied to the histograms obtained from DNA measurements. The results were compared to those of the corresponding single-cell preparations. RESULTS: Correct ploidy equivalents were calculated using the algorithm of Bins in very thin sections (+/- 3 microns). This was also the case applying the formulas of McCready and Haroske to medium-thick sections (5.3-5.9 microns). The algorithm of Bacus did not lead to reliable results. Measurements on sections thicker than approximately 7 microns led to good results without mathematical correction. CONCLUSION: Reliable results can be obtained only when knowing the exact section thickness. In very thin sections the method of Bins leads to reliable results; in medium-thick sections the methods of McCready and Haraske result in correct ploidy values. Sections thicker than 7 microns do not need histogram correction.

Adenoma↗
PubMed1997

Ploidy determination on histologic sections of breast cancer specimens by image analysis using mathematical correction algorithms.

Several mathematical correction algorithms were developed to solve the problem of the unavoidable measurement of fragmented nuclei when determining DNA ploidy on thin histologic slides. These algorithms were designed for model tissue and until now had not been tested thoroughly on malignant human tissue. We evaluated the use of mathematical correction algorithms applied to measurements on thin histologic sections of breast cancer specimens, with strict control of the section thickness. Fifteen cases of breast carcinoma with known ploidy (5 diploid, 5 tetraploid, and 5 aneuploid breast cancer samples) were included. From each tissue block, we made a single-cell preparation and cut a thin histologic section. We evaluated the thickness of each of these sections according to a recently developed protocol and included only sections with a thickness between 5 and 6 microns. We performed DNA measurements with a custom-made image analyzing system equipped with a 100x oil immersion objective. Histograms of tissue section measurements were corrected according to the algorithms of McCready and Papadimitriou and of Haroske et al. We compared these results with the uncorrected histograms and with the histograms of the single-cell preparations. We also measured the single-cell preparations with a commercially available high-resolution image cytometer. The correlation between both image cytometers used was high (r = 0.99). Histogram correction improved results of tissue section measurements in all of the nondiploid tumors when compared with the uncorrected histograms. There were no significant differences between the correction algorithms used (correlation to the single-cell measurements determined by a linear regression; r = 0.98 for both algorithms). No overcorrection of the histograms occurred. We conclude that reliable DNA tissue section measurements are possible on breast cancer specimens and that such measurements will contribute to our understanding of tumor cell kinetics in small tumor cell populations not detected in single-cell measurements.

Aneuploidy↗
PubMed1996

Comparison of different mathematical algorithms to correct DNA-histograms obtained by measurements on thin liver tissue sections.

Several mathematical algorithms have been published so far to correct histograms obtained from DNA-measurements on thin sections. All these methods require knowledge of the thickness of the section currently under investigation. As the problem of determining the actual section thickness has recently been solved, the different methods for recalculation can be compared under strictly controlled conditions. For histogram recalculation, the algorithms published by Bins, McCready, Bacus, Rigaut and Haroske are applied on a series of rat liver tissue sections with increasing section thicknesses. The histograms are compared to that of measurements of a single cell preparation of the same tissue block. Our results suggest that DNA-measurements on thin paraffin sections are possible if the actual section thickness is known. Correct ploidy equivalents throughout the whole spectrum of section thicknesses investigated are calculated using the formulas of McCready and Haroske. This is also the case using the correction method of Bins in very thin sections. The algorithms of Bacus and Rigaut do not lead to reliable results. Recalculated histograms show some differences to those obtained by DNA-measurements of single cell preparations. The histograms show broader CVs of the peaks and lymphocytes as internal ploidy standard are not useful in the majority of the algorithms. Nevertheless the promising results of this study legitimize efforts to establish standards for the interpretation of recalculated histograms in the near future. The broader applicability to tumour sections remains unproven. Therefore, further investigation are necessary using more heterogeneous tissue including aneuploid tumour cell populations.

Algorithms↗
PubMed1996

Automated cell differentiation of bronchoalveolar lavage samples with two-step image analysis.

OBJECTIVE: To establish an easy method for performing an automated differential cell count on bronchoalveolar lavage (BAL) cytocentrifuge samples using morphometric parameters acquired by a digital image analyzer. STUDY DESIGN: The study population comprised 20 satisfactory cytocentrifuge preparations routinely processed in our laboratory. Images of at least 40 fields of interest were digitized and stored. The images were analyzed to assess the planimetric parameters. These were used for cell identification. Basic morphometric parameters were acquired by an automated image analysis procedure. The results obtained by this method are compared to those of the manual counting procedure. RESULTS: Following sequential analysis, computerized identification corresponded, in > 97% of the cells, to the results of manual cell typing. After data analysis, < 1% of cells remained unidentifiable. CONCLUSION: Although the number of specimens evaluated is not yet large enough to allow a definitive statement, the use of image analysis systems seems a promising approach in automated differential cell counting in BAL preparations.

Bronchoalveolar Lavage Fluid↗
PubMed1996

[The legal status of telemedicine in Austria].

The rapid development of modern communication technologies offers new opportunities for medical diagnosis and treatment. In spite of the obvious theoretical benefits of telemedicine, which have been proven by many projects in practice, telemedicine has not become generally established in Europe. Besides lack of technical standardisation and high purchase costs, one of the reasons might be the as yet unclarified legal situation. Taking the present legal situation in Austria we tried to explore questions of liability concerning telemedicine. The outstanding point seems to lie in the contract between the participating physicians on the one hand and between the physicians and the patient on the other hand. If the consulting physician is self-employed he has to take responsibility for any error on the part of the consulted physician. However, if he is working in a hospital, then he is legally considered an "Erfüllungsgehilfe" (person employed by the debtor in the performance of his obligation) an any further doctor consulted is automatically also an "Erfüllungsgehilfe" of the hospital and therefore the hospital takes responsibility for any mistakes made by the consulted physician. Although there has not been any specific jurisdiction concerning telemedicine in Austria, the present legal provisions are adequate for reaching decisions on questions of liability, so that there are no objections from the legal point of view to the general implementation of telemedicine.

Austria↗
PubMed1995

How thick is your section? The influence of section thickness on DNA-cytometry on histological sections.

The exact determination of the thickness of paraffin sections used for DNA cytometry on histological slides is an inevitable prerequisite to obtain reliable and reproducible results. Although section thickness can be measured with great precision and accuracy using highly specialized equipment (e.g. confocal laser microscope, microinterferometer), their cost restricts availability for many laboratories. This paper describes a simple method to determine the actual thickness of routinely processed paraffin sections used for DNA cytometry employing standard laboratory equipment. To achieve this goal the given section is divided into two parts. One part is used for DNA quantitation whereas the other is re-embedded and resectioned orthogonally through its original thickness. The thickness of the re-embedded section can now easily be determined with any standard length measurement device available in light microscopy. Recalculation of the genuine DNA-content out of the measured fractioned nuclei with commercial software based on the section thickness determined by this method generated histograms with a 2c equivalent peak, whereas correction based on the microtome settings resulted in significant deviations as demonstrated on rat liver tissue.

Animals↗