Biomedical subjects

P Herlin

Publications and source records attributed to P Herlin.

At least 19 recordsLinked to original sources

PubMed2001

Mathematical morphologic segmentation dedicated to quantitative immunohistochemistry.

OBJECTIVE: To develop automatic segmentation sequences for fully automated quantitative immunohistochemistry of cancer cell nuclei by image analysis. STUDY DESIGN: The study focused on the automated delineation of cancer cell lobules and nuclei, taking breast carcinoma as an example. A hierarchic segmentation was developed, employing mainly the chaining of mathematical morphology operators. The proposed sequence was tested on 22 images of various situations, collected from 18 different cases of breast carcinoma. A quality control procedure was applied, comparing the automated method with manual outlining of cancer cell foci and with manual pricking of cancer cell nuclei. RESULTS: Good concordance was found between automated and manual segmentation procedures (90% for cancer cell clumps, 97% for cancer cell nuclei on average), but the rate of false positive nuclei (small regions labeled as nuclei by the segmentation procedure) could be relatively high (11% on average, with a maximum of 35%) and can result in underestimation of the immunostaining ratio. CONCLUSION: This study examined a preliminary approach to automated immunoquantification, limited to automated segmentation without any color characterization. The automated hierarchic segmentation presented here leads to good discrimination of cancer cell nuclei at the chosen magnification.

Breast Neoplasms↗

PubMed2000

Prognostic value of DNA cytometry in 281 premenopausal patients with lymph node negative breast carcinoma randomized in a control trial: multivariate analysis with Ki-67 index, mitotic count, and microvessel density.

BACKGROUND: The clinical relevance of DNA image cytometry (ICM) and flow cytometry (FCM) remains under investigation in breast carcinoma. The objective of the current work was to study the prognostic value of DNA ICM and FCM in a series of patients randomized in a control trial. A multivariate analysis has been performed including other factors still under investigation such as Ki-67 index, mitotic count, microvessel density, and P53 and Bcl-2 expression. METHODS: Two hundred and eighty-one patients were randomized in the European Organization for Research and Treatment of Cancer 10854 trial comparing surgery followed by one course of perioperative chemotherapy versus surgery alone. Tumor parameters studied were pT, multicentricity, tumor grading according to modified Scarff-Bloom-Richardson, estrogen receptors, mitotic count per 1.7 mm(2), MIB-1, and BCL-2 scores, microvessel density, and p53 expression. ICM DNA parameters studied from paraffin embedded specimens, were DNA ploidy, proliferative index, 2c deviation index, malignancy grade, and Auer-Baldetorp typing. FCM DNA parameters analyzed on the same samples were ploidy and S-phase fraction statistics. The influence of tumor parameters, and DNA parameters on overall survival (OS), disease free survival (DFS), and metastasis-free survival (MFS) was evaluated using the Cox model. Median follow-up was 82 months. RESULTS: For OS, the prognostic parameters retained were pathologic tumor size (pT) and mitotic index (MI). Overall survival was 94% and 68% for tumors pT1/MI less than 10 and pT2-3 MI greater than or equal to 10, respectively. For DFS, age, multicentricity, and grading according to modified Scarff and Bloom were predicting factors with the same relative risk. Disease free survival was 96%, 78% and 68% respectively, when 1, 2, or 3 of those factors were present. For MFS, the only retained predicting factor was MI. MFS was 97% and 73% when MI was less than 10 and MI was greater than or equal to 10, respectively. CONCLUSIONS: Evaluation of proliferative compartment was the most important predicting factor for OS and MFS in the current series of premenopausal lymph node negative patients with breast invasive carcinoma. When working on paraffin embedded tissue, the best way of assessing it was MI count. ICM DNA analysis results were not selected in multivariate analysis. DNA analysis by FCM should be considered as an unsuitable technique when working on paraffin embedded tissue.

Aneuploidy↗

PubMed2000

Variation of flow cytometric DNA measurement in 1,485 primary breast carcinomas according to guidelines for DNA histogram interpretation.

From 1990-1996, 1,485 previously untreated invasive breast carcinomas were sampled by a pathologist for flow cytometric DNA analysis. The aim of the present work was to study the variations of flow cytometric DNA ploidy and S-phase evaluation according to the conditions of DNA histogram interpretation. Results obtained with the American Consensus guidelines of 1993 and the François Baclesse Department of Pathology's own guidelines are presented. According to the percentage of events taken into account to identify a DNA aneuploid peak, the proportion of DNA diploid cases can change from 35-39%. For S-phase evaluation, although the two guidelines were quite different, the results of S-phase cutoff were identical. Whichever guidelines were used, there was a strong relationship between DNA ploidy and/or S-phase and classical clinicopathological factors (T, N, histological type, grade, receptor status, or lymphatic invasion), with the exception of age, whose correlation was discrepant with S phase according to the set of guidelines. Whichever guidelines were used, ploidy and S phase correlated strongly with survival (overall, metastasis-free, or recurrence-free). Hence we recommend the use of the American consensus guidelines, despite minor imperfections, because they are now well-known, allow a high yield in the ratio of assessable S phases, and permit standardization in the technical processing and reporting of S phases, thanks to the use of terciles.

Aneuploidy↗

PubMed2000

[Atypical prostatic leiomyoma: a new case with cytodensitometric analysis].

Atypical prostatic leiomyoma is a very rare benign tumor. We report here a new case with a cytodensitometric analysis. The result of cytodensitometry is a polyploid tumor that is well correlated with the morphology of nuclear multilobulated cells of this tumor. The differential diagnosis is essentially the leiomyosarcoma which is characterized by the absence of mitotic activity.

Aged↗

PubMed1999

Image analysis software for automatic DNA ploidy assessment of archival solid tumours.

BACKGROUND: Image cytometry has proved to provide a good alternative to flow cytometry for DNA ploidy measurement of archival tumors. However, when interactively done this technique is unable to give statistically valuable results within an acceptable time for clinical oncology. METHODS: An image cytometer was developed for fully automatic DNA ploidy quantitation, focusing efforts on speed and accuracy. Software functionalities include systematic acquisition of fields on a microscopic slide, detection, localization and sorting of nuclei, computation of the DNA content together with post-processing tools, for a deeper analysis of the DNA ploidy diagram. RESULTS: DNA ploidy analysis of archival breast carcinoma samples illustrates the accuracy of DNA ploidy measurements and the sensitivity in the detection of DNA ploidy abnormalities as a result of cell sorting. CONCLUSIONS: Fully automatic image cytometry is able to combine qualities of flow cytometry (automatic analysis of a statistically significant collection of cell nuclei) with additional advantages: sorting of unwanted events (debris, stromal and inflammatory cell nuclei) and facilities for an a posteriori control of the quality of cell selection. This method is well suited to DNA ploidy analysis of archival cancer samples.

Aneuploidy↗

PubMed1999

Automatic morphological sieving: comparison between different methods, application to DNA ploidy measurements.

The aim of the present study is to propose alternative automatic methods to time consuming interactive sorting of elements for DNA ploidy measurements. One archival brain tumour and two archival breast carcinoma were studied, corresponding to 7120 elements (3764 nuclei, 3356 debris and aggregates). Three automatic classification methods were tested to eliminate debris and aggregates from DNA ploidy measurements (mathematical morphology (MM), multiparametric analysis (MA) and neural network (NN)). Performances were evaluated by reference to interactive sorting. The results obtained for the three methods concerning the percentage of debris and aggregates automatically removed reach 63, 75 and 85% for MM, MA and NN methods, respectively, with false positive rates of 6, 21 and 25%. Information about DNA ploidy abnormalities were globally preserved after automatic elimination of debris and aggregates by MM and MA methods as opposed to NN method, showing that automatic classification methods can offer alternatives to tedious interactive elimination of debris and aggregates, for DNA ploidy measurements of archival tumours.

Aneuploidy↗

PubMed1999

Influence of sample size on image cytometry of DNA ploidy measurements.

OBJECTIVE: To assess the number of nuclei required for significant image cytometry DNA ploidy measurements on one archival case of breast cancer. STUDY DESIGN: From one case of aneuploid DNA breast cancer, 18 subsets made up of 152-1,524 for the whole population of undamaged nuclei and made up of 74-735 epithelial nuclei had DNA measured. DNA ploidy type and five DNA ploidy indices, allowing DNA ploidy histogram interpretation were evaluated on each population. RESULTS: Three hundred nuclei were always sufficient for DNA typing, whereas reliable results for DNA ploidy indices required at least 750 nuclei. CONCLUSION: To DNA measure the above number of nuclei, fully automated image cytometry DNA ploidy measurements are required.

Aneuploidy↗

PubMed1997

Generalized region growing operator with optimal scanning: application to segmentation of breast cancer images.

Segmentation of medical images is a complex problem owing to the large variety of their characteristics. In the automated analysis of breast cancers, two image classes may be distinguished according to whether one considers the quantification of DNA (grey level images of isolated nuclei) or the detection of immunohistochemical staining (colour images of histological sections). The study of these image classes generally involves the use of largely different image processing techniques. We therefore propose a new algorithm derived from the watershed transformation enabling us to solve these two segmentation problems with the same general approach. We then present visual and quantitative results to validate our method.

Algorithms↗

PubMed1997

Influence of debris and aggregates on image cytometry DNA measurement of archival tumors.

OBJECTIVE: To investigate, for seven samples, the influence of unwanted elements (e.g., remains of erythrocyte cell membranes, sliced nuclei, damaged nuclei and aggregates) on image cytometry DNA ploidy measurements. STUDY DESIGN: Two normal reference tissues (brain and breast), one breast cancer and four brain tumors were studied. For each sample, the influence of the different classes of debris on DNA ploidy histograms and indices was evaluated. RESULTS: The influence differs regarding each class of debris and the index to be evaluated. CONCLUSION: Strict and precise elimination of debris and aggregates is required. Moreover, strategies and efforts that must be applied to automated elimination of these unwanted elements must be a direct function of the bias they introduce into DNA ploidy measurements.

Aged↗

PubMed1997

Improvements in slide preparation from archival material for automated DNA measurement by image analysis.

OBJECTIVE: To optimize slide preparation for DNA content measurement by automated image analysis and to obtain a rapid and easy method for routine use. STUDY DESIGN: Some improvements in previously described methods were achieved: automatic dewaxing, reduction of washing times, accurate adjustment of final concentration of nuclei, sedimentation and temperate drying of nuclei. RESULTS: The complete preparation of 12 slides required four intermittent working hours. Accurate adjustment of the final concentration and sedimentation of nuclei resulted in a constant and homogeneous distribution of nuclei. Cell loss was prevented and the most fragile structures preserved. CONCLUSION: High-quality preparations of nuclei lead to high-resolution histograms obtained from a large collection of events. This promotes automated image analysis method instead of flow cytometry when only archival material is available for DNA content measurement and proliferating fraction evaluation.

Cell Nucleus↗

PubMed1997

[Automation of the cytometric analysis of the DNA content of solid tumors].

An automatic machine, dedicated to solid tumor DNA ploidy quantitation has been built in order to provide pathologists with a tool usable in clinical practice. Main efforts were focused on an automation of each step of the analysis and on an elimination of any subjective choice, while preserving the quality of measurement. As the software is independent of the machine architecture, it offers performances which increase in parallel with the rapid evolution of the computers. An illustration of the various functionalities of the automaton is proposed through the study of deparaffined breast cancer samples.

Breast Neoplasms↗

PubMed1997

[Neighborhood graphs and image processing. Contribution to images of immunohistochemical staining].

Devising an image analyzer dedicated to the automatic quantification of immunohistochemical staining for clinical oncology implies developing a method for the delimitation of tumoral cell nests, setting aside tumoral stroma, while accounting for the topology of the staining. The representation of images by neighborhood graphs can bring an answer to both requirements. In this paper, a methodological approach is presented. It consists in a preliminary study dealing with nuclear immunostaining images of breast cancer. Segmentation of the graph structure allows to separate clusters of cancer cells and the analysis of this structure can account for the focal or diffuse aspect of the staining within the tumor.

Breast Neoplasms↗

PubMed1995

Mesocaval shunt or repeated sclerotherapy: effects on rebleeding and encephalopathy--a randomized trial.

BACKGROUND: Sclerotherapy is usually effective in controlling acutely bleeding esophageal varices. It may not be as effective as shunt surgery for prevention of rebleeding; therefore we undertook a prospective study comparing interposition mesocaval shunt (MCS) and repeated sclerotherapy. METHODS: Forty-five patients (mean age, 52.6 +/- 9.8 years) with variceal bleeding were randomized after emergency endoscopic sclerotherapy either to repeat variceal obliteration followed by regular check endoscopy (n = 21) or to elective interposition mesocaval shunting by use of 14 mm polytetrafluoroethylene graft (n = 24). There was an equal distribution of Child's classes in the two groups. RESULTS: In the sclerotherapy group 12 patients had recurrent hemorrhages causing five deaths compared with the shunt group, in which four patients had postoperative bleeding but without associated death. No difference was noted in the incidence of encephalopathy despite the development of total shunting 1 year after MCS. The median hospital stay was similar; 34.5 days (MCS) and 33 days (sclerotherapy). The number of intensive care unit days was also similar in the two groups. No difference was noted in survival in patients with Child's A and Child's B disease in the treatment groups. In patients with Child's C cirrhosis there was a statistically significant longer survival in patients undergoing MCS compared with patients undergoing sclerotherapy. CONCLUSIONS: The results of the study show that the rate of rebleeding is significantly higher after sclerotherapy than after mesocaval shunting. In patients with Child's C cirrhosis MCS may be an alternative to sclerotherapy for the prevention of rebleeding from esophageal varices in patients not suitable for transplantation.

Adult↗

PubMed1995

DNA cytometric abnormalities in human esophageal squamous intraepithelial and invasive carcinomas.

DNA ploidy abnormalities of 21 archival human esophageal intraepithelial neoplasia samples were assessed, using image cytometry of deparaffinized samples, with reference to invasive squamous cell carcinoma and corresponding uninvolved squamous epithelium. Cytometric parameters investigated were proportion of G0G1 aneuploid cell population, histogram typing, proportion of G0G1 diploid nuclei, coefficient of variation, mean DNA content, crude 5c exceeding proportion, 2c deviation index, malignancy index and grade, and entropy. The distributions of the above parameters were compared using the paired t test and Fisher's exact test. Among 10 parameters used, Auer typing of DNA histograms, crude 5c exceeding rate, 2c deviation index and malignancy grade according to Böcking allowed discrimination between uninvolved epithelium and invasive squamous cell carcinoma as well as intraepithelial neoplasia. In particular, the distribution of 2c deviation index in the uninvolved epithelium did not overlap that of intraepithelial and invasive carcinomas. The above four parameters, however, were unable to discriminate intraepithelial neoplasia from invasive carcinoma.

Aneuploidy↗

PubMed1992

Development of an automatic program for the stereological estimation of the volume weighted mean volume of cell nuclei.

A stereological method was recently developed for the estimation of the volume weighted mean volume of particles from 2D sections. Several authors successfully applied this manual method to paraffin sections of bladder cancers and malignant melanomas and found a good correlation between the mean nuclear volume and the histological grading and prognosis of these tumors. The implementation of this measuring method on an automatic image analyser, devoted to routine work in tumor pathology, is presented. The accuracy of the automatic measurement has been evaluated together with the first results obtained from human esophageal cancers.

Cell Nucleus↗

PubMed1991

Three-dimensional DNA image cytometry by confocal scanning laser microscopy in thick tissue blocks.

A method for the quantification of nuclear DNA in thick tissue blocks by confocal scanning laser microscopy is presented. Tissues were stained en bloc for DNA by chromomycin A3. Three-dimensional images, 60 microns deep, were obtained by stacking up confocal fluorescent images obtained with an MRC-500 (Bio-Rad, Richmond, CA). The effects due to bleaching and attenuation by depth of fluorescence emission were corrected mathematically. The DNA contents were estimated by summing up the detected emission intensities (discretized into pixel gray levels) from each segmented nucleus. Applications to an adult rat liver and to a human in situ carcinoma of theesophagus are shown to demonstrate, respectively, the precision of the method and its potential usefulness in histopathology. Comparisons are made with DNA histograms obtained on the same materials by image cytometry on smears and by flow cytometry. Ploidy peaks obtained with the confocal method, although wider than with other methods, are well separated. Confocal image cytometry offers the invaluable advantage of preserving the tissue architecture and therefore allowing, for instance, the selection of histological regions and the evaluation of the degree of heterogeneity of a tumor.

Animals↗

PubMed1991

Factors influencing the concentrations of the large neutral amino acids in the brain and in the CSF of dogs after portacaval anastomosis.

Portal-systemic shunting of blood is associated with hyperammonemia, an increased glutamine concentration in brain, an altered plasma neutral amino acid pattern, and high levels of several of the large neutral amino acids in brain. Since some of these amino acids are precursors for neurotransmitters and for other potentially neuroactive substances, high CNS levels of these amino acids may contribute to the development of encephalopathy. In order to determine the relative importance of changes in brain glutamine levels and changes in competition among the neutral amino acids for blood-brain transport, we measured the concentrations of the large neutral amino acids in plasma, cisternal cerebrospinal fluid and in brain tissue from various regions of dogs after end-to-side portacaval shunt. Although the changes in CSF amino acid levels correlated partially with altered amino acid plasma competitor ratios, better correlations were observed with the elevation of CSF glutamine. These results suggest a model of blood-brain amino acid transport in which a high level of glutamine in brain extracellular fluid competes with other neutral amino acids for efflux from brain, thus raising brain amino acid levels after portal-systemic shunting.

Amino Acids, Essential↗

PubMed1990

The effects of ammonia tolerance tests on the cerebrospinal fluid concentrations of amino acids and indoleamines in patients with liver cirrhosis.

To study the effect of ammonia administration on amino acids and indoleamines in cerebrospinal fluid (CSF) and on amino acids, insulin, and glucagon in plasma in humans with liver cirrhosis, we performed seven ammonia tolerance tests on six patients with stable liver cirrhosis. The grade of encephalopathy was determined by psychometric tests. Only one of the patients had pronounced encephalopathy. The other patients had no or only slight encephalopathy. The plasma concentrations of valine, leucine, isoleucine, phenylalanine, tyrosine, and methionine decreased after the ammonia load, whereas no changes were found in the plasma concentrations of glucagon and insulin. In CSF the concentrations of glutamine, aromatic amino acids, and indoleamines increased only in the patient who had pronounced encephalopathy, whereas no changes were found in the other patients. The effect of an ammonia load on the concentrations of neutral amino acids in CSF in patients with pronounced encephalopathy remains to be demonstrated.

5-Hydroxytryptophan↗