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Biomedical subjects

A Gavoille

Publications and source records attributed to A Gavoille.

6 recordsLinked to original sources
PubMed1995

Heterogeneity in migration of smooth muscle cells from normal and injured rat thoracic aorta in primary culture.

OBJECTIVE: Aside from proliferation, migration of smooth muscle cells is an essential component of the arterial sclerotic reaction. The aim of this study was to define a model to study migration. METHODS: Primary cultures of smooth muscle cells were derived from normal or injured rat thoracic aorta. An image analysis system was used to track cells migrating out of the explants and measure the displacement of their centre of gravity. RESULTS: Migration speeds for smooth muscle cells randomly sampled from the normal whole media were very heterogeneous. The media were therefore separated into three vertical segments. Cells from the middle third migrated faster than those from the upper and lower thirds, regardless of whether they originated from the anterior and posterior parts of the segment (P = 0.001). Heparin (10 micrograms.ml-1) only inhibited smooth muscle cell migration from the middle segment (P < 0.001). Migration of smooth muscle cells from explants of aorta 3 and 14 d after injury was also studied using a balloon catheter. Three days after injury, cell velocity varied widely among the segments of the same media. In contrast, 14 d after injury cells from neointimal explants migrated homogeneously and at a slower rate than those obtained from normal media. CONCLUSIONS: These experiments show migratory variations among smooth muscle cells depending upon their position in the normal aorta and their state of activation after arterial injury. This variability must be taken into account when planning experiments to study smooth muscle cell migration.

Animals↗
PubMed1994

Measurement of inhibition zone diameter in disk susceptibility tests by computerized image analysis.

This paper presents an application of computerized image analysis in microbiology. This application permits the automatic detection and diameter measurement of inhibition zones in disk susceptibility tests. Each inhibition zone boundary was extracted according to an edge detection method based on the Student's t-test and a priori knowledge (geometry, densitometry). Evaluation of the method was performed by comparing the results from an image analyser and a trained observer. For this purpose, we used kappa statistics and obtained a close agreement (a kappa coefficient equal to 0.84) on a set of about 600 inhibition zones. The results encourage us to develop the method further to include the detection of antagonism and synergism.

Algorithms↗
PubMed1989

A user-oriented software for cytological image analysis. Application to automatic DNA content measurement of thyroid cells.

More and more physicians and researchers in biology and image processing and analysis are using and developing methods which involve image analysing systems: image analysis permits replacement of qualitative subjective evaluation of cytological and histological specimens by quantitative methods. The purpose of our work was to provide a software which would fulfil constraints set by different users. This software is based on the following features: an automated cytology oriented architecture, a standard user interface and a selectable user mode. The system has been used to build a protocol for DNA content measurement on thyroid cells.

DNA, Neoplasm↗
PubMed1988

In vitro chemical eradication of small cell lung cancer: application in autologous bone marrow transplantation.

Autologous bone marrow transplantation raises the question of the possible reinjection of tumour cells together with marrow. This paper investigates the ability of chemical compounds other than cyclophosphamide derivatives to eradicate small cell lung cancer (SCLC) in bone marrow. The responsiveness of SCLC lines to cis-platinum, doxorubicin, VP16, Celiptium (an ellipticine derivative), Ditercalinium, a new drug belonging to the pyridocarbazole series, and Asta Z were measured in an agar-agar clonogenic assay. Cis-platinum and Ditercalinium exhibited a high tumouricidal effect. The low cloning efficiencies of SCLC lines in an agar-agar clonogenic assay did not allow tumour cells to be detected among bone marrow cells with sufficient sensitivity. Therefore cis-platinum and Ditercalinium were tested on bone marrow-tumour cell mixtures cultured in a liquid medium allowing the detection of one tumour cell per 10(4) bone marrow cells. As cis-platinum exhibited a low myelotoxicity, it is proposed for purging bone marrows of patients with SCLC.

Antineoplastic Agents↗
PubMedDate not supplied

Quantification of intracellular calcitonin gene transcripts in human medullary thyroid carcinoma (MTC) by in situ hybridization.

The human calcitonin gene generates 2 distinct mature mRNAs by alternative RNA processing, encoding calcitonin (CT) in thyroid C-cells or a neuropeptide (CGRP) in the brain. We evaluated quantitatively by in situ hybridization the expression of the CT gene in tissue section of 5 MTCs (2 sporadic and 3 familial forms). The primary tumor of one MTC was compared to a brain metastasis. In situ hybridization was carried out with tritiated cDNA probes coding for CT and CGRP mRNA. After autoradiography the number of silver grains was counted in 400 cells by computerized analysis of digitized images and expressed as the labelling level (L.L. = grain area/cell area per day of autoradiographic exposure). This was used to calculate the relative abundance per cell of the specific messengers studied, which depends on the autoradiographic efficiency and the specific activity of the probe used. The CT mRNA content was 3.25-6.55 10(-10) micrograms equivalents in the 3 familial forms of MTC and 4.95-9.25 10(-10) micrograms equivalents for the 2 sporadic forms. The levels of CT mRNA in the brain metastasis and in the primary tumor were identical (4.10 10(-10) micrograms equivalents). CGRP mRNA expression was weaker in the sporadic and in the familial thyroid tumors (0.60-1.65 10(-10) micrograms equivalents). The content of mRNA CGRP in the brain metastasis (0.60 10(-10) micrograms equivalents) was lower than that in the primary tumor (1.05 10(-10) micrograms equivalents).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗