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Biomedical subjects

G Lasfargues

Publications and source records attributed to G Lasfargues.

At least 19 recordsLinked to original sources
PubMed1992

Comparative study of the acute lung toxicity of pure cobalt powder and cobalt-tungsten carbide mixture in rat.

Alveolitis progressing to lung fibrosis has been reported in workers exposed to cobalt containing dust (e.g., tungsten carbide-cobalt mixture as produced by the hard metal industry) but rarely following exposure to pure cobalt dust (e.g., in cobalt-producing factories). We have previously demonstrated that tungsten carbide-cobalt mixture is more toxic toward rat alveolar macrophages in vitro than pure cobalt metal powder. The present study was undertaken to compare in female rats the acute pulmonary response (lung weight, lung histology, cellular and biochemical analyses of bronchoalveolar lavage fluid, and mortality) following the intratracheal instillation of pure cobalt (Co) particles (median particle size, d50:4 microns), pure tungsten carbide (WC) particles (d50:2 microns), tungsten carbide-cobalt (WC-Co) powder (d50:2 microns; cobalt 6.3%, tungsten 84%, carbon 5.4%) and crystalline silica (d50 less than 5 micron) used as pneumotoxic reference material. WC alone (15.67 mg/100 g body wt) behaves as an inert dust producing only a mild accumulation of macrophages in the alveolar duct walls. Co alone (1.0 mg/100 g) only causes a moderate inflammatory response. An identical amount of Co given as WC-Co mixture (16.67 mg/100 g; corresponding to 1.0 mg Co/100 g) produces a severe alveolitis and fatal pulmonary edema. Cellular and biochemical characteristics of bronchoalveolar lavage fluid collected 24 hr after the intratracheal instillation of WC (1.0 mg/100 g) or Co (0.06 mg/100 g) are not significantly different from those of control animals instilled with sterile saline. On the contrary, bronchoalveolar lavage fluid changes following administration of the WC-Co mixture (1.0 mg/100 g; corresponding to 0.06 mg Co/100 g) are very similar to those induced by crystalline silica (1.0 mg/100 g). The amount of cobalt excreted in urine is significantly higher when the animals are exposed to WC-Co powder as compared to an equivalent amount of pure cobalt particles, suggesting an increased bioavailability of cobalt metal when combined with tungsten carbide. This study demonstrates that the acute lung toxicity of tungsten carbide-cobalt mixture is much higher than that of each individual component and may explain why lung fibrosis is rarely if ever induced by exposure to pure cobalt dust.

Animals↗
PubMed1992

Scintigraphy with J001X, a Klebsiella membrane glycolipid, for the early diagnosis of chronic berylliosis: results from an experimental model.

A glycolipid (J001X) isolated from the membrane proteoglycans of a non-pathogenic strain of Klebsiella pneumoniae was developed to bind selectively to macrophages. A scintigraphic technique could thus be developed and applied to an experimental model of lung berylliosis. Six baboons were injected intratracheally with a beryllium metal suspension. Three to 24 months later, they were submitted to both an anatomical and a functional respiratory evaluation. Two baboons were explored at the early stage of alveolitis and four baboons at a more advanced stage characterised by a granulomatous disorder. Scintigraphy was performed using J001X labelled with 99mtechnetium administered as an aerosol. In the six baboons, conventional imaging techniques (chest x ray film, computed tomography scan, gallium scintigraphy), failed to show either any lung abnormality or mediastinal lymph nodes consistent with beryllium disease. In the two recently contaminated baboons, J001X scintigraphy showed a well defined parenchymal fixation facing the contaminated lobe. In the four baboons who were at a more advanced stage of berylliosis, J001X fixation was always focused paratracheally without any significant involvement of the lung parenchyma. The subcarinal and laterotracheal lymph nodes seen at necropsy corresponded to J001X scintigraphic fixations. In conclusion, when compared with conventional techniques such as chest x ray film, computed tomography scan, magnetic resonance imaging, and gallium scintigraphy, J001X scintigraphy has proved its ability to detect occult lesions in experimental berylliosis in baboons. By comparison with gallium scintigraphy, scintigraphy with J001X appears to have superior sensitivity and can be performed in four hours.

Animals↗
PubMed1991

[Diagnosis and treatment of Raynaud's phenomenon].

Raynaud's phenomenon is a common, paroxysmal acrosyndrome, affecting about 4% of the general population. Most of the time it is a purely functional condition: Raynaud's disease. However, in rare cases, there is an organic cause and it is then known as Raynaud's phenomenon. In view of its prevalence, a simple, atraumatic, low cost and reliable work-up should be performed to guide diagnosis. This is based on the findings of clinical examination, capillaroscopy, antinuclear factor antibody tests and X ray of chest and hands. Only a few cases will require more specialised investigation with arteriography and autoimmune studies. The commonest causes are arterial and connective tissue diseases, especially scleroderma. However, occupational hazards, toxic and iatrogenic drug-induced aetiologies should not be overlooked. With the exception of patients who have a curable underlying disease, most cases require vasodilator therapy, the keystone of which over the last decade has been the calcium channel blockers. Only patients who are severely handicapped by their acrosyndrome should be given drug therapy.

Adrenergic beta-Antagonists↗
PubMed1991

[Pulmonary siderosis and long-term respiratory risks of arc welders].

Pulmonary siderosis and bronchial cancer are respiratory risks in the long term in arc welders. We report a case of siderosis discovered from radiological abnormalities in a patient of 56 who had been an arc welder for 30 years. An analysis of the broncho-alveolar lavage liquid and transbronchial biopsy confirmed an iron overload and revealed patchy interstitial fibrosis. The toxic risks in arc welders arise from the gaseous fumes produced and inhaled particles at the alveolar level. The pulmonary siderosis is currently considered as a simple pneumoconiosis with a good prognosis. Some recent studies suggest the possibility of a more serious outcome with fibrosis even in the absence of any associated silicosis. The risks of bronchial cancer seem to be principally linked to exposure to chrome. A better understanding of these risks could be furnished by data from epidemiological studies which are still lacking.

Bronchoalveolar Lavage Fluid↗
PubMed1991

[Lead poisoning in children. Apropos of 129 cases].

One hundred and twenty nine children with chronic lead poisoning were followed from August 1985 to July 1989. Old lead paint was recognized as the contaminant source at home. Pica of paint flakes was the main mode of intoxication. Children were classified according to the Center for Disease Control 1985 as follows: class IV (39 cases), class III (45 cases), class II (30 cases), class I (15 cases). Nineteen of those in class IV had blood lead levels above 700 micrograms/l and received BAL + EDTA followed by EDTA alone for a mean of 4.6 +/- 3.5 courses. With this treatment, blood lead level decreases were 50 +/- 17%. Nine of these class IV children had an evaluation at last 3 months after the last chelation course: 5 became class I or II, and 2 class III with a negative provocative test. The remaining 20 children in class IV were given a mean of 2.7 +/- 1.4 courses of EDTA. Blood lead levels decreased by 52 +/- 15%; 11 children were evaluable at least 3 months after the last chelation course: 4 became class I, and 7 class II. Thus overall 80% of class IV moved under treatment to class I or II. Among those 45 children in class II, 30 underwent a provocative test and 24 one to three courses of EDTA: 8 were further studied: 3 became class I and 5 class II. Combination of screening, medical treatment and sociocultural approach led to avoid acute effects of severe chronic childhood lead poisoning. The efficacy of such an approach in preventing chronic effects has still to be evaluated.

Chelating Agents↗
PubMed1990

[Validity of a short self-administered dietary questionnaire compared with a dietetic interview].

The dietary intakes of 250 men and women aged from 17 to 60 years were evaluated by means of a self-administered questionnaire. The purpose of this study was to develop and optimise a self-administered questionnaire deliberately reduced to 20 questions. The results were compared with those of a dietetic interview using the diet history method. The correlation coefficients for the main nutrients were determined by multivariate regression analysis and were found to fall in the 0.44-0.80 range (P less than 0.001). It is concluded that the self-administered questionnaire is satisfactory and valid as compared with the diet history method. The degree of validity reached is such that efficient epidemiological studies can be conducted at small cost, and the subjects at risk due to the main dietary errors listed in the contemporary French population can be detected.

Adolescent↗
PubMed1990

[Phosphorus-calcium metabolism in hyperthyroidism].

Because of the bone remodelling it induces, hyperthyroidism modifies the parameters of calcium-phosphorus metabolism. For a better determination of the mechanism involved, we studied 13 patients with Graves' disease compared with 13 controls. We measured the various parameters of calcium-phosphorus metabolism, notably the levels of parathormone, 25-hydroxycholecalciferol, 1-25 dihydroxycholecalciferol and ostocalcin; 8 patients were re-examined in euthyroidism. Total and corrected values of calcaemia (P less than 0.05 and P less than 0.01), phosphoreamie (P less than 0.01), alkaline phosphatase (P less than 0.01), calciuria (P less than 0.01) and hydroxyprolinuria (P less than 0.01) were significantly higher in patients with hyperthyroidism. Osteocalcin also was significantly increased (P less than 0.01) and correlated with thyroid hormone levels, thus confirming its usefulness as marker of bone remodelling in hyperthyroidism. Creatininaemia was significantly lowered (P less than 0.01). The intestinal absorption of calcium after injection of 1 g of calcium was reduced. Parathormone and 25-hydroxycholecalciferol levels were not significantly different in patients and in controls. In patients who were re-examined in euthyroidism, there was a significant increase in parathormone and in 1-25 dihydroxycholecalciferol levels (P less than 0.05). Thus, in situations of hyperthyroidism 2 elements contribute to a deficit in calcium balance: (a) a fall in parathormone level, consecutive to a rise in calcaemia, induces hypercalciuria; and (b) a fall in 1-25 dihydroxycholecalciferol level, consecutive to functional hypoparathyroidism and hyperphosphoraemia, results in a decrease of intestinal calcium absorption.

Adolescent↗
PubMed1990

[Treatment of a positive Rhesus D neonate born of a mother with idiopathic thrombopenic purpura with anti-D immunoglobulins (Rh O)].

A Rhesus D positive infant, born at 37 weeks of gestational age, admitted for neonatal passive immune thrombocytopenia was given 3 intravenous anti-Rhesus D immunoglobulin infusions at 3 weeks of age. This thrombocytopenia which had not responded to conventional therapy improved after the third of anti-Rhesus D immunoglobulin infusion, but the efficacy of this treatment could not be proven in this case report. However, the tolerance was good. No side-effects (jaundice, severe anemia) were observed.

Erythroblastosis, Fetal↗
PubMed1990

[Steroid-sensitive cavitating pulmonary opacity in Horton's disease].

We report the case of a 72 year old woman treated for seven months for Horton's disease presenting with a cavitating pneumonia of the left axillary segment associated with a deterioration of the general state, at the time of which the steroid therapy was in the course of being decreased. The radiological appearance and the clinical context of immune depression had led to a trial of a quadruple anti-tuberculous therapy in spite of the absence of any bacteriological proof. This rapid aggravation of the condition under treatment led to the suggestion of a pulmonary localisation of Horton's disease. The rapid regression of the lesions after increasing the dose of steroids and the negative cultures on Lowenstein medium pleaded in favour of this hypothesis. However the continuation of anti-tuberculous treatment seems justified in such cases in so far as the diagnosis of Horton's disease of the lung often cannot be maintained other than retrospectively in the absence of histological proof.

Aged↗
PubMed1990

[Ophthalmologic manifestations of the Pierre Robin syndrome. Report of a case of microphthalmia].

The classical description of the Pierre Robin syndrome includes micrognathia, glossoptosis, airway obstruction, and usual presence of a cleft palate. The Pierre Robin syndrome is currently defined as the combination of retrognathia, cleft palate, and respiratory distress. This last is mixed, with a peripheral component due to glossoptosis and a central component due to brain stem immaturity. The main ocular manifestations found in the Pierre Robin syndrome are congenital glaucoma and severe congenital mypopia responsible for retinal detachment. Microphthalmia is infrequent. We report the case of a neonate with severe Pierre Robin syndrome and major microphthalmia documented by CT scan.

Female↗
PubMed1990

[Pleural effusion induced by bromocriptine].

Bromocriptine, a derivative of ergot of rye, is used in high doses for the treatment of Parkinson's disease and may be responsible for pleuro-pulmonary complications. We report a case of a 72 year old patient treated for 2 years for Parkinson's disease with a daily dose of 30 mgms. of bromocriptine and in whom a pleural effusion, initially unilateral then bilateral, was discovered with a deterioration in the general physical state. The effusion was a transudate and examination did not give any clues as to aetiology, there was a rapidly favourable outcome following the cessation of treatment. Amongst the respiratory complications of bromocriptine it is the pleuro-pulmonary fibrosis which is most frequently reported. The cases of isolated pleural effusions are rare and are generally exudates. Several hypotheses have been put forward to explain the pathogenesis of these disorders: there is a theory that the molecule induces a toxic fibrogenesis, there is a vascular theory analogous with the secondary effects of methysergide and finally immunological theory. The frequency of the disorder is probably underestimated and these drug reactions justify a close follow up for any respiratory problems in patients who are subjected to treatment with bromocriptine.

Aged↗