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Biomedical subjects

A Gschwendtner

Publications and source records attributed to A Gschwendtner.

At least 19 recordsLinked to original sources
PubMed2000

Optimized preembedding method improves the histologic yield of prostatic core needle biopsies.

BACKGROUND: The aim of this study was to optimize the core shape of prostatic core needle biopsies using a novel preembedding method, and to investigate the influence of the number of cores per tissue block on the histologic yield per section level. METHODS: Twenty-four core needle biopsies were taken from a fresh prostatectomy specimen, using an 18-gauge needle. Twelve core needle biopsies were conventionally fixed floating free in formalin-filled containers, whereas 12 biopsies were stretched between two nylon meshes, and placed in tissue cassettes before fixation. The total number of tissue sections per paraffin block necessary for complete workup of the tissue was determined. Using image analysis, the relation of the area of every fifth section level was calculated in relation to the total projected area of the biopsies. Both methods of tissue processing were compared for both parameters. RESULTS: In contrast to the curved biopsies after conventional processing, the optimized preembedding method generally led to stretched cores after fixation and embedding. This method led to a 100% decrease in total number of tissue sections necessary for complete workup and to higher percentages of the tissue amount per section level compared to the total projected core area. These parameters were also influenced by the number of cores per paraffin block, but to a minor degree. CONCLUSIONS: This study shows that optimized preembedding of prostatic needle biopsies improves the histologic yield per section level. The continuous occurrence of representative sections could improve diagnostic accuracy in the histological examination of prostatic core needle biopsies.

Biopsy, Needle↗
PubMed1999

Underestimated health hazard: proposal for an ergonomic microscope workstation.

Working daily for a long time with a standard microscope causes back pain, fibromyalgia, or tension headache in up to 80% of microscopists. These complaints may be prevented by an ergonomic design of the microscope workstation, leading to a beneficial and significant reduction of electromyographical activity in the most strained muscle groups as shown by surface electromyographic recordings.

Adult↗
PubMed1999

Nuclear chromatin texture analysis of nonmalignant tissue can detect adjacent prostatic adenocarcinoma.

BACKGROUND: The aim of this study was to investigate the possibility of identifying prostatic adenocarcinoma by nuclear chromatin texture feature analysis of adjacent histologically benign-looking tissue. METHODS: Two hundred and forty prostatectomy specimens were selected from the archives of the Department of Pathology, University of Innsbruck. These consisted of 67 cases of benign prostatic hyperplasia (BPH) and 173 cases of prostatic adenocarcinoma (PAC). The specimen collection was divided randomly into a training set and test set. Cytospin preparations of disaggregated cells prepared from paraffin-embedded material were stained specifically for DNA by the Feulgen method. For the cancer cases, only tissue that histologically appeared nonmalignant, from the vicinity of the lesion, was used in the sample preparation. Only normal-appearing diploid cell nuclei were analyzed from both the BPH and PAC groups. A discriminator comprised of three nuclear texture features to separate BPH from PAC cases was derived from the training set of cases, and then applied to the independent test set cases. RESULTS: PAC cases were separated from BPH cases with a sensitivity of 90% and a specificity of 97% on the independent test set of cases. CONCLUSIONS: This retrospective investigation demonstrates that by high-resolution image cytometry it is possible to detect the presence of prostatic adenocarcinoma with very high reliability when examining prostate samples that only contain histologically normal-looking cells. This method could become clinically relevant in identification of cancers missed by histologically negative core needle biopsies.

Adenocarcinoma↗
PubMed1999

Quantitative assessment of bladder carcinoma by acid labile DNA assay.

BACKGROUND: Effective noninvasive methods for monitoring patients with bladder carcinoma and screening for bladder carcinoma that show better performance than the methods currently in use would be desirable for detecting urothelial carcinoma at an early, easily treatable stage. A rapidly hydrolyzed component of nuclear DNA has been described, the increase of which has been linked to malignancy. Quantitative determination of acid labile DNA has been applied successfully to detect other neoplasms. This study investigates the potential of this method to detect transitional cell carcinomas. METHODS: Touch imprints of transurethral resection material from 62 cases of nonmalignant urothelium (control group including reactive changes) and 94 cases of bladder carcinoma were analyzed. The full Feulgen hydrolysis profiles of the nonmalignant and malignant urothelial cells were compared by measuring the staining density of the nuclei using digital image analysis after various hydrolysis times. Twenty cells were sampled randomly from among the cells measured for calculation of the mean optical density (MOD). The MOD of each time was used to build the hydrolysis profile of a case. RESULTS: A hydrolysis time of 10 minutes was found to be the most discriminative between control and carcinoma cases. Applying a single threshold MOD value of 101 resulted in a test sensitivity of 95.7%, a specificity of 94.4%, a positive predictive value of 98.3%, a negative predictive value of 95.9%, and an area under the receiver operating characteristic curve of 0.97. CONCLUSIONS: The results of this pilot study suggest that measurement of the rapidly hydrolyzed component of DNA present in the nuclei of bladder urothelium offers a highly sensitive and reliable supplement to the qualitative and subjective cytologic procedures currently in use.

Carcinoma, Transitional Cell↗
PubMed1999

Septicaemia and endomyocarditis caused by Aerococcus urinae.

Aerococcus urinae, an uncommon urinary tract pathogen, was recently shown to cause septicaemia and endocarditis in a few patients in Denmark and the Netherlands. In Austria this is the first report of a fatal course of endomyocarditis by Aerococcus urinae, associated with multiple septic infarcts.

Adult↗
PubMed1999

DNA-ploidy analysis correlates with the histogenetic classification of thymic epithelial tumours.

The ploidy values of the epithelial component were determined in a series of thymomas and organotypic thymic carcinomas using image cytometry and the results were compared with the histological tumour subtypes according to the histogenetic classification introduced by Marino, Müller Hermelink, and Kirchner (MMHK). Forty-six cases of thymic epithelial tumours were included in the study. After reclassification according to the MMHK classification, the distribution among the subtypes was as follows: three medullary, nine mixed type, five predominantly cortical (organoid), 16 cortical thymomas, and 13 well-differentiated thymic carcinomas. Single cell preparations were made from paraffin-embedded tumour tissue and stained according to Feulgen. Ploidy analysis was performed using an automated image analysis system. In five cases, DNA cytometry could not be performed, for technical reasons. The remaining 41 cases consisted of 11 diploid and 30 non-diploid tumours. The percentage of aneuploid tumours in the different subtypes increased from medullary (0 per cent) through mixed type (44.4 per cent), predominantly cortical (75 per cent), cortical (83.3 per cent) to well-differentiated thymic carcinomas (100 per cent). DNA-ploidy determination using image cytometry correlates with the concept of the MMHK classification of thymomas.

Humans↗
PubMed1999

Are nuclear texture features a suitable tool for predicting non-organ-confined prostate cancer?

PURPOSE: We investigated the possibility of determining organ confinement of prostate cancer using multiple nuclear texture features determined by fully automated high resolution image analysis combined with preoperative serum PSA levels. MATERIALS AND METHODS: The study population consisted of 145 patients (61 organ confined and 84 non-organ-confined cases). Nuclear texture features were determined using single cell preparations of radical prostatectomy specimens. Nuclear texture features were extracted and analyzed by multivariate logistic regression analysis in order to build a classifier for distinguishing between organ confined and non-organ-confined tumors. The classifier was designed in a cell by cell model and tested on a case by case analysis. RESULTS: The predictive probability of the trained classifier in the cell by cell analysis had a sensitivity of 63%, a specificity of 53%, a positive predictive value of 75% and a negative predictive value of 38% and an area under the ROC curve of 0.58. In the case by case analysis the sensitivity was 70%, the specificity was 54%, positive predictive value 78%, negative predictive value 74%, area under the ROC curve 0.62. When preoperative PSA was included in the algorithm, sensitivity raised to 80%, specificity to 60%, the positive predictive value raised to 79%, the negative predictive value to 52% and the area under the ROC curve to 0.70. CONCLUSIONS: In contrast to former studies using tissue sections, our results suggest that nuclear texture features extracted from single cell preparations cannot be used as a reliable parameter for the determination of organ confinement in prostatic adenocarcinomas.

Adenocarcinoma↗
PubMed1999

Quantitative assessment of bladder cancer by nuclear texture analysis using automated high resolution image cytometry.

The aim of this study was to investigate the possibility of identifying urothelial neoplasia by nuclear chromatin texture feature analysis using high resolution image cytometry to improve the diagnostic accuracy of cytologic examination in the detection and monitoring of bladder cancer. Touch imprints of transurethral resection material of 56 control group (CG) cases of nonmalignant urothelium and 94 tumor group (TG) cases of bladder cancer were analyzed. The specimen collection was divided randomly into a training set and a test set. Cells were stained specifically for DNA by the Feulgen method. Only diploid cell nuclei were analyzed from both groups. A discriminator comprised of three nuclear texture features was derived from the training set of cases to separate CG from TG cases. This discriminator was then applied to the independent test set. CG cases were separated from TG cases with a sensitivity of 97% and a specificity of 95% on the independent test set of cases. When dividing TG cases into high-risk and low-risk groups, sensitivity in the low-risk group was 93%. None of the high-risk cases was misclassified (sensitivity, 100%). This retrospective investigation demonstrates that by high-resolution image cytometry it is possible to distinguish between urothelial neoplasia and normal urothelium with high reliability when examining diploid cell nuclei only. This method is superior to DNA ploidy analysis using image or flow cytometry and may become clinically relevant as a supplement to conventional cytologic examination. These promising results should be confirmed on cytologic preparations derived from bladder washings or voided urine.

Adult↗
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↗