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J A Beliën

Publications and source records attributed to J A Beliën.

14 recordsLinked to original sources
PubMed2000

A histopathological contribution to supratentorial glioma grading, definition of mixed gliomas and recognition of low grade glioma with Rosenthal fibers.

BACKGROUND: Previous glioma studies have described separate grading systems for oligodendrogliomas and astrocytomas. Many of these gliomas contain mixtures of neoplastic astrocytes and oligodendrocytes. Prognosis may be related to the percentages of these neoplastic components. Previous survival/grading studies have been limited to histopathological features but have not evaluated the importance of percentages of neoplastic components. This study attempted to perceive the relative importance of percentages of neoplastic astrocytes and oligodendrocytes for definition of astroglial, oligodendroglial and mixed oligoastroglial tumors. After determination of these limits we explored the possibility to develop a grading system for common supratentorial gliomas based on reproducible histopathological features. METHODS: A retrospective study was performed of 362 cases of unselected supratentorial glioma. One hundred and thirty-eight binary and nine continuous histopathological variables, amongst which percentages of neoplastic astrocytes and oligodendrocytes, were scored and related to survival. Only well reproducible histological features were accepted in Cox regression to define glioma grades. RESULTS AND CONCLUSIONS: Supratentorial gliomas appeared to be composed of variable percentages of neoplastic oligodendrocytes and astrocytes, but this spectrum did not correspond to a continuous change in prognosis. Gliomas containing 30% or more neoplastic oligodendrocytes had a slightly better outcome (p < 0.0432) but higher percentages did not further improve prognosis. Percentages of neoplastic astrocytes were not correlated to survival. We therefore propose to designate gliomas containing 30% or more neoplastic oligodendrocytes as oligodendroglial tumors, and others as astroglial tumors. From a prognostic point of view there is no need to recognize mixed oligoastrocytomas. An interesting finding was the recognition of a low grade glioma group with Rosenthal fibers, which had the longest postoperative survival. Another prognosticator of interest concerns the mitotic rate as a continuous variable. Atypical mitoses indicated the worst survival, after necrosis. It was possible to develop a grading system for all supratentorial gliomas using six reproducible histological parameters: necrosis, atypical mitoses, the mitotic rate, endothelial proliferative activity, percentage of neoplastic oligodendrocytes and Rosenthal fibers. This resulted in four grades for astroglial tumors (p < 0.002) and three grades for oligodendroglial tumors (p < 0.008) which differed significantly within each group with respect to survival.

Adolescent↗
PubMed1999

Relationships between vascularization and proliferation in invasive breast cancer.

Studies on relationships between angiogenesis and tumour cell proliferation have provided conflicting results. This study has therefore investigated the relationships between the number and location of fully automatically identified CD31-positive microvessels and interactively segmented mitoses and necrotic compartments by image processing. These features were studied in ten invasive breast cancers, in the 'hot spots' and in whole tumour sections. Microvessel and mitosis hot spots were topographically close or overlapping and were always located at the periphery of the tumour. The numbers of mitoses and microvessels per mm(2) in the hot spot were strongly correlated with the respective numbers in the whole tumour section, as well as mutually. The ratio of mitoses in the hot spot to the whole tumour section was significantly higher than the corresponding microvessel ratio. Mitoses were preferentially located at a distance of 50-150 microm from microvessels. No significant difference was found between the average distance between mitoses and microvessels in the whole tumour sections and in the hot spot (79 vs. 72 microm), although considerable inter-tumour differences were found (hot spot 43-101 microm, tumour 47-111 microm). The presence of necrotic areas correlated with the number of mitoses per mm(2) and necrosis was in general observed at a distance of more than 150 microm from the microvessels, suggesting that necrotic areas have outgrown their vascular system. These results indicate the usefulness of image processing of whole tumour sections for the identification of proliferation and vascularization hot spots, which are strong prognostic factors in breast cancer. The results also support a close relationship between tumour necrosis and microvessels.

Breast Neoplasms↗
PubMed1999

Fully automated microvessel counting and hot spot selection by image processing of whole tumour sections in invasive breast cancer.

BACKGROUND: Manual counting of microvessels is subjective and may lead to unacceptable interobserver variability, which may explain conflicting results. AIMS: To develop and test an automated method for microvessel counting and objective selection of the hot spot, based on image processing of whole sections, and to compare this with manual selection of a hot spot and counting of microvessels. METHODS: Microvessels were stained by CD31 immunohistochemistry in 10 cases of invasive breast cancer. The number of microvessels was counted manually in a subjectively selected hot spot, and also in the same complete tumour sections by interactive and automated image processing methods. An algorithm identified the hot spots from microvessel maps of the whole tumour section. RESULTS: No significant difference in manual microvessel counts was found between two observers within the same hot spot, and counts were significantly correlated. However, when the hot spot was reselected, significantly different results were found between repeated counts by the same observer. Counting all microvessels manually within the entire tumour section resulted in significantly different hot spots than manual counts in selected hot spots by the same observer. Within the entire tumour section no significant differences were found between the hot spots of the manual and automated methods using an automated microscope. The hot spot was found using an eight connective path search algorithm, was located at or near the border of the tumour, and (depending on the size of the hot spot) did not always contain the field with the largest number of microvessels. CONCLUSIONS: The automated counting of microvessels is preferable to the manual method because of the reduction in measurement time when the complete tumour is scanned, the greater accuracy and objectivity of hot spot selection, and the possibility of visual inspection and relocation of each measurement field afterwards.

Breast Neoplasms↗
PubMed1998

Progression from colorectal adenoma to carcinoma is associated with non-random chromosomal gains as detected by comparative genomic hybridisation.

AIMS: Chromosomal gains and losses were surveyed by comparative genomic hybridisation (CGH) in a series of colorectal adenomas and carcinomas, in search of high risk genomic changes involved in colorectal carcinogenesis. METHODS: Nine colorectal adenomas and 14 carcinomas were analysed by CGH, and DNA ploidy was assessed with both flow and image cytometry. RESULTS: In the nine adenomas analysed, an average of 6.6 (range 1 to 11) chromosomal aberrations were identified. In the 14 carcinomas an average of 11.9 (range 5 to 17) events were found per tumour. In the adenomas the number of gains and losses was in balance (3.6 v 3.0) while in carcinomas gains occurred more often than losses (8.2 v 3.7). Frequent gains involved 13q, 7p, 8q, and 20q, whereas losses most often occurred at 18q, 4q, and 8p. Gains of 13q, 8q, and 20q, and loss of 18q occurred more often in carcinomas than in adenomas (p = 0.005, p = 0.05, p = 0.05, and p = 0.02, respectively). Aneuploid tumours showed more gains than losses (mean 9.3 v 4.9, p = 0.02), in contrast to diploid tumours where gains and losses were nearly balanced (mean 3.1 v 4.1, p = 0.5). CONCLUSIONS: The most striking difference between chromosomal aberrations in colorectal adenomas and carcinomas, as detected by CGH, is an increased number of chromosomal gains that show a nonrandom distribution. Gains of 13q and also of 20q and 8q seem especially to be involved in the progression of adenomas to carcinomas, possibly owing to low level overexpression of oncogenes at these loci.

Adenoma↗
PubMed1997

Counting mitoses by image processing in Feulgen stained breast cancer sections: the influence of resolution.

Counting of mitotic cells has been shown to be of prognostic value in breast cancer in different retrospective studies. Up to now the number of mitoses is assessed mainly manually according to a standardized but strict protocol. Although such a manual procedure is reasonably reproducible, automatic counting of mitotic cells offers the potential for greater objectivity and reproducibility. This paper describes the influence of resolution on automatic recognition by image processing of mitotic cells in Feulgen stained breast cancer sections. Using the image recording, correction and segmentation procedure described in a previous study, five specimens were analyzed: one was used to serve as a training set and four were put aside for later use as independent test set. For each slide, objects from a pre-selected area were recorded at increasing resolution. For each object, contour features and optical density measurements were computed and stored in a data file for statistical analysis. The results showed that increased resolution using a 40x objective lowered the number of misclassified mitoses compared with a 20x objective (overall mean percentage of misclassified mitoses over training and all test specimens: 20x, 24.57; 40x, 7.96). The number of misclassifications of non-mitoses was almost stable per specimen but varied between specimens (19-42%) due to differences among tissues. Given the improvement in classifying mitoses and the possibility to evaluate interactively the measurement result, the described semi-automated mitoses pre-screener of histological sections may be suitable for further testing in a clinical setting.

Breast Neoplasms↗
PubMed1995

Drug resistance-associated marker Lrp for prediction of response to chemotherapy and prognoses in advanced ovarian carcinoma.

BACKGROUND: Drug resistance is a major impediment to the successful treatment of ovarian carcinoma. None of the earlier-identified resistance mechanisms, such as overexpression of the MDR1 gene product, P-glycoprotein (Pgp), has been shown to be a major determinant of clinical response to chemotherapy and survival for ovarian cancer patients. The multidrug resistance-associated protein (Mrp) and the lung resistance protein (Lrp, also called the p110 major vault protein), are newly described proteins associated with multidrug resistance in vitro. PURPOSE: The aim of this retrospective study was to investigate the expression of Mrp and Lrp, in addition to Pgp, in advanced ovarian carcinoma and to determine whether such expression was predictive of response to chemotherapy and survival. METHODS: Fifty-seven banked frozen specimens, previously collected and frozen at the time of diagnosis from an equal number of patients with International Federation of Gynecology and Obstetrics (FIGO) stage III or IV ovarian carcinoma, were immunostained for Pgp (with monoclonal antibodies [MAbs] MRK-16 and JSB-1), Mrp (with MAb MRPrl), and Lrp (with MAb LRP-56). All patients had received platinum- or alkylating-based chemotherapy after debulking surgery. Clinicopathologic parameters determined at diagnosis were retrospectively assessed for their relationship with Pgp, Mrp, and Lrp expression. Response to treatment and survival were compared between Pgp, Mrp, and Lrp expression groups. Qualitative variables were analyzed using Fisher's exact test or the chi-squared test. All reported P values are two-tailed. RESULTS: Nine (16%), 39 (68%), and 44 (77%) of the 57 tumor specimens examined showed positive immunostaining for Pgp, Mrp, and Lrp, respectively. Positive immunostaining for these proteins was not associated with any other prognostic factor examined. No association was found between Pgp and Mrp expression and response to chemotherapy and survival. In contrast, patients with Lrp-positive tumors had poorer response to chemotherapy (P = .004) and shorter progression-free (P = .003) and overall (P = .007) survival than Lrp-negative patients. Multivariate analysis of Lrp expression, FIGO stage, residual tumor after initial surgery, tumor grade, and presence or absence of ascites showed that only Lrp status was independently related to both progression-free survival and overall survival. CONCLUSIONS: Positive Lrp immunostaining in advanced ovarian carcinoma appears to be an indicator of poor response to standard chemotherapy (platinum or alkylating agents) and of adverse prognoses. IMPLICATIONS: The functional characterization of Lrp and related proteins may reveal new approaches to modulate Lrp-associated drug resistance. A large prospective study is warranted to confirm the prognostic value of Lrp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Standardization of counting micronuclei: definition of a protocol to measure genotoxic damage in human exfoliated cells.

The proportion of exfoliated buccal mucosal cells with micronuclei gives the opportunity to assess sensitivity to gamma-radiation and genotoxic compounds and in addition to monitor the effectiveness of cancer intervention strategies. So far, results on counting micronuclei in various publications are difficult to compare because of differences in methods used, especially with regard to microscopical magnification used and number of cells counted. The aims of this study were (i) to define a protocol for counting micronuclei; (ii) to assess the feasibility of manually counting micronuclei; and (iii) the assessment of inter- and intra-patient variability of the number of micronuclei. We propose the definition of a strict protocol on counting micronuclei, with regard to cytological preparation, definition of micronuclei, instrumentation, sampling of cells in a cytological specimen and sample size. Such a strict protocol is a prerequisite for counting micronuclei in exfoliated cells to get a reproducible and sensitive indicator of exposure and for cancer risk. Although the inter- and intra-observer reproducibility of counting micronuclei per 1000 cells using such a protocol is well, we show that the variability among 10 assessments of micronuclei per 1000 cells taken sequentially from a sample size of 10,000 nuclei of the same specimen can be enormous (coefficients of variation varied in seven individuals studied between 42.1 and 102.9%). Based on the observed low frequencies varying from 1.2 to 5.2 micronuclei per 1000 cells and the variation found, we conclude that at least 10,000 exfoliated cells should be screened to monitor a significant reduction of 50% in the number of micronuclei (for a patient with an initial frequency in the micronuclei frequency range given). Since it takes approximately 7 h to evaluate this number of cells, it is also concluded that counting of micronuclei requires automation.

Acetylcysteine↗
PubMed1995

Volume-weighted mean nuclear volume and nuclear area in advanced ovarian carcinoma. An investigation of sampling methods, sample size and reproducibility.

The influence of sampling issues on the reproducibility of volume-weighted mean nuclear volume (mean v) and mean nuclear area (MNA) assessments in patients with International Federation of Gynecology and Obstetrics stage III and IV ovarian carcinoma was evaluated. Ten cases representing the whole range of MNA values were selected from a population of 131 cases. The MNA and mean v of the same tumor cell nuclei were determined in one session by switching between the stereologic module and the morphometric module of the video overlay program used. For both MNA and mean v in one series of measurements, tumor nuclei were sampled from the whole tumor area and in a second series from the most poorly differentiated part (the measurement area) in each section, thus giving four series of measurements per case. For all four series, 500 nuclei were point sampled from approximately 100 systematically randomly selected fields of vision, using the automated scanning stage controlled by the morphometry program. These large samples, containing 500 nuclei for each case, were regarded as representative in each case. To investigate the susceptibility of MNA and mean v to variance at lower sampling levels (fields, nuclei), a nested analysis of variance was performed. Then the influence of sample size and sampling method was evaluated by drawing subsets from these 500 nuclei in each case in three different ways (cluster, systematic or random) with four different sample sizes (50, 100, 125, 250). It was shown that for MNA assessed in the measurement area, the variance between patients contributed the most to the total variance.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma↗
PubMed1994

Highly sensitive, specific, and stable new fluorescent DNA stains for confocal laser microscopy and image processing of normal paraffin sections.

The area, volume, shape, DNA content, and chromatin pattern of nuclei can be important for the diagnosis and prognosis of cancers. Confocal laser scan microscopy can be useful to obtain such information by optical slicing and three-dimensional (3-D) reconstruction of nuclei in thick paraffin sections. To retrieve individual quantitative features from the section, highly sensitive, specific, and stable fluorescent stains are required. Two new nuclei acids stains (TOTO-1 iodide and YOYO-1 iodide) can detect picogram amounts of nucleic acids in gels. Despite their high sensitivity to detect DNA, they have not been used to stain nuclei in paraffin embedded tissue sections (as routinely applied in surgical cancer pathology). We have developed a technique to stain nuclei in 4% buffered formaldehyde fixed paraffin tissue sections using TOTO-1 iodide and YOYO-1 iodide. The technique developed gives bright specific staining of the nuclei (with nearly zero background intensity, much less than with acriflavine). Moreover, TOTO-1 iodide and YOYO-1 iodide stains both give fluorescent signals only when they interact with DNA. Thus washing off the excess stain left on the stained specimen is not necessary (washing of excessive stain is necessary with acriflavine). Care has to be taken that the deparaffinizing liquids (xylol etc.) are not polluted with eosin (a frequently used counterstain in surgical pathology specimens), as this gives undesired fluorescence of cytoplasm and connective tissue at the same wavelength as TOTO-1 iodide and YOYO-1 iodide. Contrary to acriflavine, bleaching of TOTO-1 iodide and YOYO-1 iodide fluorescence is minimal, even after 30 min continuous laser light excitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acriflavine↗
PubMed1994

Integrated decision support system/image archive for histological typing of breast cancer using a relation oriented inference system.

Histological typing of invasive breast cancer according to the World Health Organisation criteria is prognostically relevant, because some histological subtypes have a markedly better prognosis. However, reproducibility of histological typing is not high because of the absence of strict typing criteria, variations in the application of the typing criteria and the usually limited illustration of the relevant criteria. The aim of this study was to develop an expert system based on highly structured histological typing criteria, integrated with high-quality microscope images to illustrate the typing criteria. This system should be useful as a decision support system in the diagnosis of breast cancers and should increase the reproducibility of histological typing. Criteria for typing were extracted from textbooks and, based on experience, these criteria were structured and implemented in the Relation Oriented Inference System (ROIS), in which information can be structured by defining relations. Illustrative black and white images were digitized and integrated into the shell. The performance of the resulting decision support system was evaluated by a group of six pathologists using a set of slides covering the spectrum of the most frequently occurring histological types of invasive breast cancer. The pathologists first assessed histological type according to standard morphological procedures. The cases were then reassessed with the decision support system available for consultation. The use of the decision support system appeared to influence the previously assessed histological type in about half of the cases. Using the decision support system, histological typing was more uniform and more in accord with a 'gold standard' set by two experts.(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Intelligence↗
PubMed1994

Measurement by confocal laser scanning microscopy of the volume of epidermal nuclei in thick skin sections.

The mean volume and shape of nuclei assessed in standard tissue sections by means of stereologic and morphometric methods are associated with prognosis in tumors of different sites. Thus, accurate quantification of the volume and shape of cell nuclei can be important for cancer patients and also may be useful for a better understanding of basic cellular events, such as growth and differentiation. Confocal laser scan microscopy (CLSM) makes it possible to obtain image sets consisting of very thin serial optical slices from thick tissue sections. These images can be used with digital image processing to construct a three-dimensional (3-D) model of individual nuclei. We used CLSM to study a 50-micron-thick paraffin section of a skin biopsy. Image processing was applied to the CLSM images to precisely segment epidermal nuclei from the background, and serial two-dimensional (2-D) binary images were created. Alignment of the 2-D images that form the 3-D model of the original nuclei was carefully controlled. The series of 2-D binary images was connected with an algorithm to form the 3-D model of each complete nucleus and organized for the 3-D visualization and analysis using a 3-D volume rendering method. In this way we measured the volume and surface area of 22 intact epidermal nuclei. The mean nuclear volume was 174.7 micron3, the standard deviation of the volume 26.47 micron3, the mean surface area 168.0 micron2 and the standard deviation of the surface area 22.00 micron2.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Nucleus↗
PubMed1993

Method for counting mitoses by image processing in Feulgen stained breast cancer sections.

This study describes an image processing method for the assessment of the mitotic count in Feulgen-stained breast cancer sections. The segmentation procedure was optimized to eliminate 95-98% of the nonmitoses, whereas 11% of the mitoses did not survive the segmentation procedure. Contour features and optical density measurements of the remaining objects were computed to allow for classification. Twelve specimens were analyzed, nine used to serve as a training set, and three put aside for later use as independent test set. The fully automatic image processing method correctly classified 81% of the mitoses at the specimen level while inserting 30% false positives. The automatic procedure strongly correlated with the interactive counting procedure (r = 0.98). Although the fully automatic method provided satisfactory results, it is not yet suited for clinical practice. The automated method with an interactive evaluation step gave an accurate reflection of the mitotic count showing an almost perfect correlation with the results of the interactive morphometry (r = 0.998). Therefore this semiautomated method may be useful as prescreening device.

Automation↗
PubMed1993

Quantitative microscopical and confocal laser scanning microscopy for intermediate endpoint biomarkers in breast cancer: potential and reproducibility.

Diagnostic quantitative pathological (QP) determinations are increasingly used in our hospital. The number of requests for QP for reference materials is rising rapidly. This is understandable; quantitative assessments have a strong prognostic value and can be very reproducible, depending on the care taken with a number of factors including cell and tissue processing, application of the appropriate stains, and the measurement protocol used. As to the latter, systematic random sampling gives the best intra- and interobserver agreement (with correlation coefficients between observers for certain features > or = 0.94). Flow cytometric determinations are often regarded as more reproducible than interactive morphometry due to the high speed of the assessments, the large number of objects measured per specimen, and the lack of observer interaction. Indeed, flow cytometrically assessed DNA ploidy is very reproducible, even though the % S-phase fraction is much more variable. Unlike image cytometry (ICM), visual inspection of cells is not easily accomplished with flow cytometry (FCM). With ICM, the fully automated measurement of DNA in thousands of cells is possible in 3-5 minutes, with a very low coefficient of variation (< or = 2% for the diploid and tetraploid peak of liver cell nuclei). ICM also allows measurement of texture features. However, quantitative immunohisto/cytochemical determinations may not always be as reproducible as sometimes believed. Recently, we found large variations in the measurements, made by a commercially available image processing instrument, of the estrogen and progesterone receptors, Ki-67, cathepsin D, and neu protein overexpression in breast cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗