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Biomedical subjects

J R Viallat

Publications and source records attributed to J R Viallat.

At least 55 records · Page 3Linked to original sources
PubMed1986

Bilateral pleural plaques in Corsica: a non-occupational asbestos exposure marker.

The North-East quarter of Corsica being rich in asbestos deposits, we checked the chest radiographs of 1721 patients born in North Corsica, without occupational exposure to asbestos, in order to show an excess of asbestos pleural plaques in those born in the N.E. quarter. Of the 56/1710 patients with bilateral plaques, 53 were born in N.E., and three in N.W. The incidence of plaques was thus respectively 3.7% and 1.2% (p less than 0.05). The site of birth of these 56 patients was compared to that of 213 matched control patients without plaques, born in North Corsica. The percentage of patients with plaques born in villages with asbestos deposits was 94.6 per cent, versus 58.2 per cent for the control patients; the relative risk index is 12.7. This work is the first report of environmental asbestos plaques in Western Europe.

Aged↗
PubMed1985

[Yield of the thoracoscopic biopsy in experimental pulmonary infections in the immunosuppressed rabbit].

Using thoracoscopy lung biopsy we investigated the bacteriological diagnostic yield in immunodepressed and/or infected NZ rabbits. 84 rabbits were used: 18 controls, 30 immunodepressed rabbits and 36 rabbits immunodepressed and then infected with Aspergillus fumigatus. Candida albicans or B.C.G. The thoracoscopy technique was the one we designed for humans, the instruments were adapted to the size of animals. Thoracoscopy biopsy results were compared to those of surgical biopsies made in the same animals. The results of both techniques were similar: indeed, the sensitivity of thoracoscopy biopsy was 88.9% in immunodepressed rabbits (versus 100% with surgical biopsies), 86% in the group of rabbits infected with B.C.G. (versus 86%), 90.1% in rabbits infected with Aspergillus fumigatus (versus 100%) and 88.9% in rabbits infected with Candida albicans (versus 100%). The indications for thoracoscopic lung biopsy in immunodepressed patients with infectious lung diseases are drawn from these experimental data, from our experience and the known mortality and morbidity of surgical lung biopsy.

Animals↗
PubMed1984

[Diagnosis of localized pulmonary opacities by transbronchial biopsy].

In order to assess the value of transbronchial biopsy (BTB) in the diagnosis of local pulmonary opacities, we have carried out a prospective study from October 1981 to August 1982 on 180 patients with a localised pulmonary opacity radiographically. 73 presented with a tumour visible fibreoptically in whom the diagnosis was made by bronchial biopsy. In 56 patients the clinical and biological picture were not suggestive of a malignancy and the lesion disappeared in 15 days on antibiotic treatment. Finally in 51 subjects the cancerous nature of the opacity was strongly suspected and the indication for a BTB were met. We obtained the following results: among 51 patients 11 were suffering from the sequelae of non-progressive disease and 40 of progressive disease; namely a sensibility of 80% and a specificity of 100%. The results vary as a function of the size of the tumour and its localisation. The best results were obtained for tumours with a diameter of greater than 3 cm, in the middle third of the lung (diagnosed by BTB 9 times out of 10). Thus transbronchial biopsy seems to be the first invasive examination to contemplate in the diagnosis of localised pulmonary opacities.

Adenocarcinoma↗
PubMed1982

Thoracoscopic lung biopsy. Experimental and clinical preliminary study.

We have investigated thoracoscopic lung biopsy (TLB) as an alternative to surgical biopsy. TLB was performed under mild general anesthesia, with two openings: one for the telescope, and one for a 5 mm in diameter biopsy forceps connected to diathermocoagulating device. TLB was first tested on 14 dogs (22 TLB) and then on 75 subjects (77 TLB): 35 patients with pleural diseases and 40 patients with undiagnosed lung diseases despite previous investigations including transbronchial biopsy. TLB yielded a high rate of adequate samples (up to 5 x 5 x 5 mm) in both experimental (95 percent) and clinical series (96 percent). Overall sensitivity equalled 923 percent, ranging from 70 percent in peripheral localized lesions to 100 percent in diffuse lung diseases. The mean period of systematic drainage was 3.4 +/- 0.3 days, and the main complications we encountered were one transient blood-streaked sputum specimen and eight localized pneumothoraces during drainage. TLB is indicated when other medical procedures have failed, and has thus proved, in this series, to be as sensitive as surgical biopsy with less morbidity and no mortality.

Animals↗
PubMed1982

Induction of antibody-producing cell lines by Epstein-Barr virus.

This work makes a critical evaluation of EBV transformation as a tool for establishing human antibody producing lines. Since Steinitz et al. described the technique in 1977, at least 9 lymphoid cell lines with predetermined specificities have been reported with activity against NNP, TNP, A-CHO, phosphorylcholine, human Ig, Rh-D antigen and tetanus toxoid. Most successful attempts were based on the choice of immune donors and on the adequate selection of peripheral antigen-specific B cells with antigen-coated erythrocytes. When lines were established, a further selection of antigen-specific lymphoblastoid cells using several steps of rosetting or cloning proved to be necessary, in order to get mono- or oligoclonal lines, and thus to maintain an antibody production for a prolonged period (up to 18 months). Secretion ranged from 0.1 to 16 micrograms antibody per ml, depending on the lines. Two of the antibodies produced are used as biological reagents. When compared to hybridomas, EBV transformed lines have the disadvantage of a lower colony forming efficiency, and usually a lower level of antibody secretion. On the other hand, if fusion of EBV induced lymphoblastoid cell lines proves to be possible with human myeloma lines and results in the creation of hybridomas, EBV transformation might reveal a useful technique to raise minute amounts of antigen specific cells to the amount of cells required for the fusion techniques.

Animals↗
PubMed1981

Thoracoscopy in malignant pleural effusions.

In a consecutive series of 1,000 patients admitted since 1970 for pleural effusions, 215 with undiagnosed chronic effusions (with previous negative cytologic and needle biopsy results) underwent thoracoscopy. The investigation was usually performed under general anesthesia, originally with a 9-mm diameter cold light laparoscope, but, since 1978, with a 7-mm diameter thoracoscope of our design with biopsy forceps connected to a diathermocoagulating device. Thoracoscopy diagnosed 131 of 150 malignant effusions in the series. We observed no false positive results. A repeat pleural cytology and needle biopsy performed the day before thoracoscopy yielded only 41% positive results. The higher yield by our new thoracoscope (97% positive results, versus 78% with the laparoscope) can be accounted for by a better visualization of the pleural space, easier handling of biopsy material, and the systematic use of diathermocoagulation. Complications were rare, minor, and not life-threatening.

Biopsy, Needle↗
PubMed1981

[Current indications for thoracoscopy].

Thoracoscopy is performed at best with a rigid apparatus and a cold light source using a single or double site of entry into the chest. Biopsy under direct vision requires a double-spoon biopsy forceps that can be connected to diathermy to insure haemostasis and prevent any air leak age. Some authors prefer a local anaesthesia but a light general anaesthesia with or without intubation allows a safe and painless examination. Numerous biopsies can be obtained for subsequent examinations, like light or electron microscopy, immunofluorescence, bacteriology and mineral studies as well as search for hormonal receptors sites on tumours. Complications are rare and fatalities exceptional (4 cases in a review of the literature covering 3.384 cases. 2 of which occurred in a small series of 150 cases). In chronic pleurisies secondary to cancer, a diagnosis was made in 92% of cases. In suspected pleural mesothelioma, thoracoscopy allows both diagnosis and staging. In pleural tuberculosis, a diagnosis is obtained in 93% of cases. Talc pleurodesis in the treatment of chronic recurrent malignant pleural effusions is successful in 80%. In the treatment of spontaneous pneumothorax with a mean follow up of 10 years, only 6.6% recurred after talc poudrage, and functional sequelae were minimal; no talcomas induced mesotheliomas were seen in a review of 151 cases. Thoracoscopic lung biopsy has an 87 to 94% success rate depending on series, and is thus comparable to surgical biopsy with a markedly smaller morbidity and mortality. It should thus be used more widely by pneumologists.

Biopsy↗
PubMed1981

[Lung biopsy by thoracoscopy (author's transl)].

60 patients had 1 to 7 biopsies during thoracoscopy under light anaesthesia without tracheal intubation. Biopsies were performed under direct vision using a separation puncture. Double-spoon biopsy forceps (5 mm in diameter) connected to a 120 watt diathermy apparatus avoided any air leak age and ensured haemostasis as the biopsy was taken. The dry weight of the biopsies ranged between 5 and 40 mg, allowing appropriate studies with light or electron microscope, for bacteriological and mineral analysis, and for hormone receptors search in cancer cases. A size 20 to 30 Charrière drain was left for a mean of 3 days. No serious complications arose. Ten patients had a 38 degrees C fever for a few hours. In one case early in the study a drain had to be changed on the third day. An histopathological diagnosis was made in 12 out of 14 patients with localised pulmonary opacities and in all 14 cases with diffuse opacities. In 32 cases of pleural involvement the presence or absence of concomitant lung involvement could be demonstrated. Asbestos fibres counts by electron microscopy correlated fairly with previous exposure to asbestos. The sensibility of the technique was 96% (percent of true positives) and the specificity 100% (percent of true negatives). Thoracoscopic lung biopsy may thus be compared very favourably to techniques of lung biopsy and deserves a larger studies in order to confirm its low morbidity.

Adolescent↗
PubMed1981

[The metrology of mineral fibres in thoracoscopic lung and pleural biopsies. Preliminary results (author's transl)].

Metrology of mineral fibres by electron microscopy was carried out in thoracoscopy specimens ("normal" parietal pleura, pleural plaque, tumour, lung) obtained from different sites in 19 patients: 9 exposed to asbestos and 10 non-exposed controls. With regard to results concerning the parietal pleura, the differences in exposure of the patients (as revealed by history) were not reflected by metrological characteristics (nature and number of fibres, size, topographical distribution) and it was impossible to distinguish the exposed cases from the controls. The number of fibres ("non-measurable presence" being 130.10(3) fibres/g) did not differ significantly between the two "exposed" and "non-exposed" groups. By contrast, the number of fibres found in lung biopsies was in general very high in exposed patients (up to 379.10(3) fibres/g.) In 3 non-exposed patients, there was no asbestos in the lung. Broadly speaking, metrological data were similar to those previously obtained in other cases and using surgical or autopsy specimens. This reinforces the validity of the method of metrology in thoracoscopic specimens and confirms the complexity and difficulties of assessment of pleural involvement. The advantages of study of early pleural specimens obtained under thoracoscopic control in comparison with surgical or autopsy specimens remains to be determined in a larger number of cases. The safety of the method should be emphasized, no complications having been seen in this series.

Asbestos↗
PubMed1980

Radiological features in chrysotile asbestos mine and mill workers in Corsica.

Workers with a well-defined asbestos exposure were compared with a matched control group: 47% of workers had abnormal X-ray features. The dust-weighted-time exposure was significantly higher in miners with severe fibrosis or with bilateral pleural thickening than in workers with normal X-rays. Since age, tobacco consumption and length of exposure were similar in all the workers, these data indicate the importance of dust concentration in the induction of asbestos-related disorders.

Age Factors↗
PubMed1979

[Thoracoscopy in pleural mesothelioma. Diagnostic, prognostic and therapeutic interest (author's transl)].

Thoracoscopy with a single opening was carried out under general anesthesia with a cold light thoracoscope of 7 mm in diameter. Biopsies were taken under visual control for optical and electron microscopic examination. In a series of 40 mesotheliomas, 30 patients with pleural effusion underwent 36 thoracoscopies. In 29 patients the macroscopic lesions were compatible with the diagnosis of mesothelioma. The most specific aspects consisted in white-yellowish nodules, almost translucent, arising from the parietal pleura (9 patients). Another typical pattern, a dense pleural thickening, was found in 10 patients. In the remaining patients, the lesions observed were less specific. The biopsy was positive in 35/36 thoracoscopies (97%). A talc poudrage was carried out in 10 patients: their mean survival was 458 days. In ten matched mesothelioma patients who underwent pleurectomy the mean survival was only 395 days. In 12 patients at an early stage, the visceral pleura was not involved by the tumor: their mean survival was 636 days. In 11 patients both parietal and visceral pleura were involved by the tumor: their mean survival was 138 days: (p less than 0,001). It is concluded that in mesothelioma pleural effusions, thoracoscopy is a safe and efficient procedure in order to reach a precise diagnosis, prognosis and efficient palliative treatment of the effusion.

Humans↗
PubMed1977

Increased stimulatory capacity of spleen cells from adult thymectomized mice in mixed lymphocyte reactions.

Conflicting results have been reported concerning the effect of adult thymectomy (A-Tx) on the mixed lymphocyte reaction (MLR) response. Our purpose was to test the reverse question, namely the effect of A-Tx on the stimulatory capacity of mouse lymphocytes carrying allelic disparities at the Mls and the H-2 loci. Spleen cells from A-Tx CBA donors were found to be significantly more stimulating than cells from normal donors. That A-Tx could eliminate suppressor T cells involved in MLR regulation or in preventing back stimulation is not likely according to our data. An increment in expression or in accessibility of Mls or H-2 antigenic determinants induced by A-Tx is no more likely, since a smilar increase in lymphocyte proliferation was observed in syngeneic cultures. The most probable explanation remains that A-Tx discloses a strongly stimulatory subpopulation, perhaps acting in part nonspecifically. The hypothesis of an enrichment in B cells versus a loss of T cells is not compatible with our findings, since B-cell-enriched fractions from various origins never attained the stimulating ability disclosed by A-Tx cells. Moreover, the cell involved is theta-positive, although slightly nylon-wool-adherent, and thus shares several properties with immature T cells involved in auto-rosette formation.

Aging↗
PubMedDate not supplied

Late progression of radiographic changes in Canari chrysotile mine and mill exworkers.

The present radiological status of 133 exworkers (mean age: 58 +/- 0.7 yr) of the chrysotile mine of Canari (Corsica) was compared to that recorded in 1965, when the mine was closed. The mean time since first exposure is 27 +/- 0.4 yr, and the mean time since termination of asbestos exposure equals 16 +/- 0.3 yr. This study showed an evolution of radiographic changes: in 1965 only 14% of the subjects had grade 1/1 or more parenchymal fibrosis, and 6% had bilateral pleural lesions; in 1979 these percentages reached 40% and 27%, respectively. Subjects who had a given parenchymal change in 1965 (e.g., 1/1 grade lesions) were older and had a more intensive dust exposure and tobacco consumption than exminers who developed the same parenchymal changes much later. A progression of parenchymal changes was observed in 39% of the subjects with normal findings in 1965, and in 63% of the subjects with grade 1/1 or more changes in 1965. Those who progressed (46% of the cohort) were older, had a longer exposure, and a more intensive dust exposure and cigarette smoking than nonprogressors.

Age Factors↗
PubMedDate not supplied

Pleural migration of chrysotile fibers after intratracheal injection in rats.

After intratracheal injection of 0.5 mg of UICC chrysotile, rats were sacrificed at various time intervals over a 1-month period, and their pleural cavity washed with saline. Samples were examined by means of transmission electron microscopy for identification, quantitation, and sizing of chrysotile fibers. No fibers were found in control rats injected with saline. The size and quantity of fibers that reached the pleural cavity of test rats was time-dependent, with two peaks on day 7 (mean number = 9.6 X 10(4); mean length = 1.3 micron) and on day 21 (mean number = 1.3 X 10(5); mean length = 0.3 micron). Such variations are compatible with a heterogeneous migration of chrysotile fibrils toward the pleura.

Animals↗