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Biomedical subjects

T Mairinger

Publications and source records attributed to T Mairinger.

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↗
PubMed2000

Radical prostatectomy: the value of preoperative, individually labeled apical biopsies.

PURPOSE: Involvement of the prostatic apex with adenocarcinoma is a relatively common finding, as is a positive surgical margin at this location. We evaluated whether a positive apical core biopsy provides preoperative information that may be used as a basis for the subsequent surgical approach in individuals. MATERIALS AND METHODS: We evaluated apical prostate cancer in 240 individually labeled, preoperative apical core biopsies and the corresponding prostatectomy specimen in 120 patients who underwent radical prostatectomy for clinically localized prostate cancer. Sensitivity, specificity, and positive and negative predictive values were calculated for the ability of an individual apical core to predict the side of tumor in the surgical specimen using 2 x 2 contingency tables. Moreover, univariate subset analysis was done for positive biopsies to assess the ability of histopathological characteristics, including Gleason score, cancer length, percent of cancer in the core and distance of cancer from the inked rectal core end, to predict a positive surgical margin at the apex. RESULTS: The positive predictive value of a single positive apical core for identifying tumor location correctly in the prostatectomy specimen was 71.1%, while absent cancer in the apical biopsy had a negative predictive value of 75.5%. Sensitivity was 44.5% for a positive biopsy core. In this context the predictive value of an individual positive apical core biopsy was only 28.8% for predicting surgical margin positivity at the apex. CONCLUSIONS: Cancer and its histopathological characteristics in an individual core biopsy failed to predict apical tumor involvement as well as a positive apical margin at subsequent radical prostatectomy.

Adenocarcinoma↗
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

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

Reproducibility and efficiency testing of two sampling methods for image analysis in cytology.

OBJECTIVE: Quantitative nuclear DNA analyses and nuclear morphometry have become a widely used tool in pathology. Nevertheless, studies done by different observers utilizing the same methods very often have shown different results. One of the reasons could be that different sampling methods were used. In this study two selection methods for image analyses (the consecutive selection method and the random selection method) were tested for reproducibility and efficiency. STUDY DESIGN: Using an interactive imaging analysis system, 10 cases (5 breast adenocarcinomas, 3 prostatic cancers, 1 sarcoma, 2 prostatic hyperplasias) were measured twice by using each sampling method. Median nuclear area and entropy (i.e., a statistical descriptor of DNA histograms) were the parameters calculated. RESULTS: The results showed that using the consecutive selection method, the number of individual nuclei in a cytologic sample that should be measured to obtain reproducible results was 150 for nuclear area and 110 for entropy. The corresponding figures using random systematic selection method were 80 for assessment of nuclear area and 100 for assessment of entropy. CONCLUSION: Both methods showed high reproducibility and a good correlation with each other. The mathematical idea of "plateau values," which was used to estimate the number of measurements needed, was considered a good contribution to increasing the efficiency of both methods.

Breast Neoplasms↗
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

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↗