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G Brugal

Publications and source records attributed to G Brugal.

At least 19 recordsLinked to original sources
PubMed1992

HOME: highly optimized microscope environment.

The Highly Optimized Microscope Environment (HOME) is a computerized microscope designed to assist pathologists and cytotechnicians in clinical routine tasks. The prototype system consists of a IBM-PC compatible computer and a light microscope in which a built-in high-resolution computer display image is superimposed on the optical image of the specimen. Also, a manually operated encoding stage and objective turret encoder are used to provide continuous monitoring of the stage coordinates and microscope magnification to the computer. This allows any position on a slide to be uniquely defined and makes it possible to measure interactively lengths and areas larger than the size of the microscope field. Software, written in the C language and operating under the MS-DOS/MS-Windows environment, is controlled by means of a mouse-driven cursor moving over menu light-buttons displayed on the microscope image. The HOME microscope workstation is potentially useful in a wide range of applications such as i) tagging information on particular cells and tissue structures that can thus be accurately located and relocated, ii) performing morphometric measurement, differential counting, and stereological assessment of biological specimens, and iii) training and educating laboratory personnel. Finally, HOME will offer in the near future a user-friendly interface for automatic image processing of cells and tissue entities in interactively selected specimen areas.

Animals↗
PubMed1992

Fluorescence image cytometry of nuclear DNA content versus chromatin pattern: a comparative study of ten fluorochromes.

This study is intended to be the first step of an in situ exploration of the intranuclear DNA distribution by image cytometry (SAMBA) with several fluorochromes. The nuclear DNA content and the chromatin pattern, revealed by ten fluorochromes (HO, DAPI, MA, CMA3, OM, QM, AO, EB, PI, and 7-AMD), were analyzed on mouse hepatocytes fixed by the Boehm-Sprenger procedure optimal for preserving the chromatin pattern. The question was whether fluorochromes specific to DNA make it possible to accurately quantitate the total nuclear DNA content when the chromatin pattern is preserved. Only HO and MA were found to provide satisfactory quantitation of nuclear DNA content, as assumed by both a small CV and a 4c to 2c ratio equal to 2. PI, EB, 7-AMD, and OM provided higher CV values, although the 4c to 2 c ratio was still equal to 2. QM, AO, CMA3, and DAPI provided non-reproducible and non-stoichiometric nuclear DNA content measurements under the fixation conditions used. The intranuclear and the internuclear SD of the fluorescence intensities describing the fluorescence pattern of the 2c hepatocytes proved to vary according to both the basepair specificity and the binding mode of the fluorochromes. The results reported here argue in favor of an external binding of 7-AMD to DNA and an increased quantum yield of QM when bound to AT-rich DNA. For PI, EB, 7-AMD, and OM, the measured DNA content increased with the fluorescence distribution heterogeneity. This correlation was not observed with other fluorochromes and is suggested to result from decreased fluorochrome accessibility to DNA when the chromatin is condensed. This study demonstrates that under conditions that preserve chromatin organization, only HO for AT-rich DNA and MA for GC-rich DNA can be used, alone or in combination, to measure nuclear DNA content. With other fluorochromes, either the measured DNA content or the chromatin pattern is assessed in suboptimal conditions when fluorescent image cytometry is used.

Animals↗
PubMed1992

The HOME microscope workstation. A new tool for cervical cancer screening.

The Highly Optimized Microscope Environment (HOME) is a computerized microscope design for assisting pathologists and cytotechnologists in routine clinical tasks. The prototype system consists of an IBM PC-compatible computer and a light microscope in which a built-in high-resolution computer display image is super-imposed on the optical image of the specimen. Also, an encoding stage and objective turret encoder are used to provide continuous monitoring of the stage coordinates and microscope magnification to the computer. This allows any position on the stage to be uniquely defined. Software, written in C language and running under the MS-DOS/MS-Windows environment, is controlled by means of a mouse-driven cursor. A specific application has been developed for cervical cancer screening, taking into account the needs and constraints of microscopists performing this task. Informatics tools offered by the HOME system provide them with precise flagging and relocation of objects on the slide, control of the scanning pathway, and ability to write and print the report directly through the microscope. The computer files generated by microscopic examination are stored and contain information available for quality control assessment and laboratory management.

Cytodiagnosis↗
PubMed1991

Ki-67 labeling in postmitotic cells defines different Ki-67 pathways within the 2c compartment.

Simultaneous quantification of DNA and Ki-67 proliferation-associated antigen was performed using fluorescence image cytometry. In the MCF-7 cell line, the Ki-67 antigen content increases during the cell cycle, and its intranuclear distribution pattern varies. Quantitative evolution of Ki-67 content as a function of nuclear area makes it possible to define several pathways followed by cells going through the 2c compartment. 1) In some cells, the amount of Ki-67 antigen remains constant during G1 (Ki-67 stable pathway), and a characteristic speckled pattern can be observed. 2) In the larger fraction of cells analyzed, there is a postmitotic decrease in the Ki-67 (Ki-67 decrease pathway) content. In this pathway, labeling is located in the nucleoplasm in small nuclei, is located in nucleoli in intermediate-sized nuclei, and is absent from larger nuclei (G0). A progressive increase in Ki-67 content (Ki-67 increase pathway) was observed from intermediate-sized nuclei to S phase nuclei. From these results, we hypothesize that the Ki-67 stable pathway is the G1 phase of newly formed cells going directly to S phase in local optimal conditions of growth and that Ki-67 decrease pathway and Ki-67 increase pathway correspond to cells whose progression to S phase is regulated by extracellular factors.

Animals↗
PubMed1991

Inhibitory effect of 17 beta-estradiol on thymocyte proliferation and metabolic activity in young rats.

Proliferation of 21-day-old rat thymus lymphocytes has been assessed after 7 daily injections of 17 beta-estradiol (E2). Two methods were used: 1) image cytometry of cell nuclei using the SAMBA 200 image processor, and 2) cell culture making it possible to design cell proliferation assay, mitochondrial activity evaluation and measurement of IL2 activity. Using image cytometry, we found a significant decrease in the proliferation index at the dose of 100 micrograms of E2 per day. When 200 micrograms and 400 micrograms per day were given, this decrease reached 70% of inhibition. 3H-thymidine incorporation was significantly reduced in cell culture even after 5 micrograms of E2 per day. On the other hand, with either 5 micrograms or 50 micrograms of E2, a significant increase of IL2 was found in the supernatant.

Animals↗
PubMed1990

Detection of S cells and evaluation of DNA denaturation protocols by image cytometry of fluorescent BrdUrd labelling.

This paper addresses the problem of detecting weak incorporation of BrdUrd and the related efficiency of the denaturation protocols used to unmask this thymidine analog. Evidence is presented that measuring the distribution of BrdUrd-tagged fluorescence intensities by image cytometry generates a standard deviation threshold that discriminates between positive and negative MRC5 cells in vitro. A comparison of the thresholding by standard deviation (SDT) with the usual thresholding by the nuclear total fluorescence intensity (FIT) demonstrated that SDT has a significantly higher sensitivity (99.4-100%, depending on the denaturation protocols) than FIT (94.7 and 74.3%, respectively), although both tests have a high specificity (93% and 100%, respectively) for detecting S cells. Since detecting the S cells is not only dependent on the test used, but also on the denaturation protocols, a quality index (QI) was derived from the standard deviation and the mean value of the non-specific fluorescence of negative cell population versus BrdUrd fluorescence of positive cell population. The following DNA denaturation protocols have been assessed according to QI: acidic denaturation, thermal denaturation in formamide, and thermal denaturation in distilled water. Each denaturation procedure was preceded or not by incubation in either proteinase K or Triton X-100. The results showed that thermal denaturation in formamide, especially when preceded by proteinase K incubation, revealed the largest difference between negative and positive cells. This work also demonstrated that image cytometry of BrdUrd-labelled cells can be suitable for clinical application because of the high sensitivity provided and the small samples needed.

Bromodeoxyuridine↗
PubMed1990

Quantitative analysis of cytoskeletal proteins throughout the cell cycle of the MRC-5 fibroblastic cell line.

Fluorescent dyes were used to stain actin, vimentin, tubulin and DNA in the same MRC-5 fibroblastic cells. Cytofluorometry and image analysis were then used to quantitatively evaluate the F actin, vimentin and tubulin content throughout the cell cycle. The results showed that different cells can have the same DNA content while their cytoskeletal protein content is variable. The data also showed that cytoskeletal protein content variations exist throughout the cell cycle of the fibroblastic cell line. The F actin content increased during the cell cycle from G1 to G2 phases and decreased in M phase. The amount of tubulin in the G2 was about twice as much as that in the G1 phase, before decreasing in the M phase; there was a threshold of tubulin content for G2 cells entering S phase.

Actins↗
PubMed1989

[Contribution of quantitative cytology and ploidy in the diagnosis and monitoring of tumors of the bladder. Study of 52 cases using the Samba analyser].

Image processors and present specific software applications have now placed scanning microcytometry in the ranks of other conventional technics for routine laboratory examinations, particularly for urinary cytology and DNA measurements (ploidy). Conventional urinary sediment smears of 52 patients with bladder tumor were digitized, processed and statistically analyzed by the image analyzer, Samba. They were automatically classified and ploidy measurements were made and compared with 6 conventional cytological diagnostics for each smear. The Samba program assigns the cell images to two classes, negative and positive. 100% of the cells were correctly classed with respect to the cytologist's diagnostics. Within the positive class the degree of malignancy established by the program was the same as the cytologist's classifications. For smears of class III, the comparison of the diagnostics of the cytologists for each patient permitted the validation of the differential classification, negative-positive, made using quantitative cytology. The interpretation of the two DNA histogram parameters, the degree of ploidy and the proliferation index, provided an excellent prognosis of which patients would show tumoral recrudescence, as verified by follow ups.

Cytophotometry↗
PubMed1988

Image cytometry of estrogen receptors in breast carcinomas.

A significant level of estrogen receptors (ER) in breast cancer cells is an indication of tumor differentiation and suggests that a homeostatic control of cell growth may persist in these cancers. In medical practice, the Dextran-coated charcoal assays (DCCA) are still the most frequently used test to characterize patients having ER-positive malignant breast tumors and for whom hormonal therapy is justified. Nevertheless, this routine biochemical technique is not satisfactory because it is a broad method unsuitable for revealing receptor tissue heterogeneity. However, immunocytochemical labeling, such as the ER-ICA method, which involves a monoclonal antibody linked to peroxidase, is a specific reaction for this purpose but which until now was not quantitative. The present study uses an original cell preparation technique combining the PAP reaction with toluidine blue counterstain for image analysis on the SAMBA system. Special software has been developed for the quantitative analysis of immunocytochemistry in cancers. Results obtained showed a high correlation between the DCCA values and the score derived from the mean ER concentration per positive tumor cell and the labeling index. In addition, intracell and intratumor heterogeneity can be displayed according to several parameters and were shown to vary according to tumor and to antiestrogen (Tamoxifen) presurgical therapy.

Breast Neoplasms↗
PubMed1987

Cytometry of breast carcinoma: significance of ploïdy balance and proliferation index.

Image cytometry of DNA distribution in fine needle biopsies of breast carcinomas at first diagnosis was performed to see if there were significant differences in DNA histograms between patients having very different outcome but same tumor histological typing and similar therapy. Two groups of patients were considered retrospectively: the first (20 patients) with survival time shorter than 5 years and the second (20 patients) with survival time longer than 10 years. Seven benign tumors were used as controls. Ten ploïdy classes were defined. The frequencies of cells in those classes were used as independent features in a supervised multivariate analysis. The advantages of this approach was pointed out with respect to the four-type classification of Auer. The scattering of DNA histograms within the feature space showed that a subgroup of patients with poor prognosis was clearly separated from a subgroup of patients with good prognosis but both long survival patients and short survival patients were scattered in between. In order to replace the multivariate classification of histograms by a simpler approach, two parameters were computed which explained most of the scattering in the feature space: the ploïdy balance (difference between the percentages of euploid and aneuploïd cells) and the proliferation index (percentage of cells between peaks). The scattergram of patients according to these parameters showed again that some DNA distributions were specific for either good or bad prognosis. But the separation was uncertain for seven short-survival patients and six long-survival patients. For six patients, the DNA distributions were very similar between long and short survival times. Those patients thus could not be separated even by means of discriminant analysis. The main conclusion of this study was that, for a significant number of patients, the objective multivariate classification of tumors DNA profiles is of little assistance to the pathologist who has to give a prognosis for the one patient under consideration.

Aneuploidy↗
PubMed1987

A quantitative analysis of the human bone marrow erythroblastic cell lineage using the SAMBA 200 cell image processor. I. The normal maturation sequence.

A quantitative image analysis of the normal maturation sequence for the human bone marrow erythroblastic lineage was performed using the SAMBA 200 cell image processor. The different image analysis steps (image acquisition, preprocessing, segmentation, parametrization and data analysis) are briefly described. Thirty-three parameters related to geometry, color, texture and densitometry were computed on 638 cell images belonging to the five erythroblastic maturation stages. The automated classification of these cells, based upon a stepwise linear discriminant analysis, resulted in 80% correctly classified cells. Acceptance of confusions between successive maturation stages enhanced the rate of correctly classified cells to 100%. Among the ten most discriminating parameters, the nuclear area showed the highest correlation with the changes throughout the maturation process. The projection of the maturation sequence onto the factorial plane resulting from the canonical analysis emphasizes the existence of three phases of the maturation process, a finding that correlates well with the cytologic evolution and the biochemical and functional events during the maturation. The trajectory of cells within this factorial plane is thus regarded as a differentiation path from which a measure of the maturation could be derived.

Bone Marrow Cells↗
PubMed1986

An iterative region-growing process for cell image segmentation based on local color similarity and global shape criteria.

An image segmentation process was derived from an image model that assumed that cell images represent objects having characteristic relationships, limited shape properties and definite local color features. These assumptions allowed the design of a region-growing process in which the color features were used to iteratively aggregate image points in alternation with a test of the convexity of the aggregate obtained. The combination of both local and global criteria allowed the self-adaptation of the algorithm to segmentation difficulties and led to a self-assessment of the adequacy of the final segmentation result. The quality of the segmentation was evaluated by visual control of the match between cell images and the corresponding segmentation masks proposed by the algorithm. A comparison between this region-growing process and the conventional gray-level thresholding is illustrated. A field test involving 700 bone marrow cells, randomly selected from May-Grünwald-Giemsa-stained smears, allowed the evaluation of the efficiency, effectiveness and confidence of the algorithm: 96% of the cells were evaluated as correctly segmented by the algorithm's self-assessment of adequacy, with a 98% confidence. The principles of the other major segmentation algorithms are also reviewed.

Biometry↗
PubMed1979

A double scanning microphotometer for image analysis: hardware, software and biomedical applications.

A new image processing system designed for densitometry and pattern analysis of microscopic specimens is described with special regard to the hardware, the software and the biologic applications. The data acquisition procedure involves the combination between the scanning of the preparation by means of a motorized stage and the scanning of successive fields by a mechanical device. The signal provided by the photomultiplier is converted into digital values which are directed to an on-line computer. The data processing is based on a one-pass computation involving automata theory and therefore it avoids the storage of the image in the computer memory. In so doing, an entire and continuous image of the whole preparation can be processed at the highest magnification of the microscope whatever the size of the analyzed specimen may be. A biologic application of the system is reported and concerns the automatic identification and counting of cells in the various phases of the mitotic cycle.

Animals↗
PubMed1979

[SAMBA : a cytophotometer coupled to a computer for the purpose of the automatic study of cell kinetics and the recognition of cell types].

The system SAMBA has been designed for automatic analysis of biological images, at the cellular or subcellular level. The examination is performed at the maximum resolution power of the microscope. It enables to discriminate by means of a pool of morphological and densitometrical parameters, between cells in the different phases of the cell cycle, or between cells belonging to various types in heterogeneous populations. Other recognition programs are at present beeing in progress, in order to promote the use of SAMBA in other fields of fundamental research and clinical application. Owing to the minicomputer now in use, SAMBA is an autonomous system, capable of beeing routinely used in diagnostic centers.

Bone Marrow Cells↗
PubMed1977

[A new image-processing system designed for densitometry and pattern analysis of microscopic specimen. Application to the automated recognition and counting of cells in the various phases of the mitotic cycle (author's transl)].

A new image analysing system, designed for microphotometric measurement and pattern recognition has been applied in the discrimination of cells from the various phases of the mitotic cycle. The data acquisition procedure is controlled by a programmable electronic unit and involves the combination of the shifting of the microscope moving stages and the scanning of the successive fields by a mechanical device. The data processing is achieved by a computer. The preliminary results we obtained have shown that such a system allows the automatic recognition and counting of the M, G1, S and G2 cells as also the G0 resting cells. The most useful parameters of the cell proliferation kinetics are thus obtained from a single specimen of a cell population.

Cell Count↗
PubMed1975

[Effects of LSD-25 on the cell cycle of Pleurodeles Waltlii Michah. embryos treated at the end of gastrulation].

LSD-25 lengthens the G2 and M phases of the cell cycle in embryos treated at the late gastrula stage and labelled with tritiated thymidine. This antimitotic effect of LSD-25 is comparable to the similar effect of colchicine or vinblastine, but is weaker. Cell distribution among the phases of the cell cycle has been studied by cytophotometry; mitotic index has been calculated, and curves of labelled mitoses variation have been established.

Amphibians↗