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Biomedical subjects

C Fabre

Publications and source records attributed to C Fabre.

At least 55 records · Page 3Linked to original sources
PubMed1993

No effect of an antiaggregant treatment with aspirin in small cell lung cancer treated with CCAVP16 chemotherapy. Results from a randomized clinical trial of 303 patients. The "Petites Cellules" Group.

BACKGROUND: Experimental, and more recently, clinical data have suggested the influence of hemostasis in the spread of malignant disease. METHODS: To complete research in this type of coagulation and cancer, a multicentric randomized clinical trial was performed, including 303 patients with small cell lung cancer (SCLC), treated by the addition of aspirin at 1 g/day (a dosage at which aspirin is considered to be a platelet aggregation inhibitor) to combined chemotherapy. RESULTS: Survival was not increased in the aspirin-treated group (P = 0.90). The analysis according to the extent of disease (limited or extensive disease) did not modify that conclusion. CONCLUSIONS: This result does not confirm the hypothesis that, in SCLC, aspirin (a platelet aggregation inhibitor) reduces metastasis formation and local tumor thrombogenesis.

Adult↗
PubMed1993

Structural and functional analysis of the human vasoactive intestinal peptide receptor glycosylation. Alteration of receptor function by wheat germ agglutinin.

The vasoactive intestinal peptide (VIP) receptor from the human melanoma cell line IGR39 has been shown to be a 60-kDa glycoprotein. Using serial lectin affinity chromatography, as well as specific glycosidases, we demonstrate that VIP receptor-linked carbohydrates are predominantly tri- or tetraantennary sialylated N-linked oligosaccharides, 27% of which are fucosylated, and some may have terminal galactose residues. Treatment of 125I-VIP receptor complexes with peptide-N4-(N-acetyl-beta-D-glucosaminyl)asparagine amidase revealed the presence of at least three N-linked carbohydrate chains/receptor polypeptide. To investigate the functional role of the carbohydrate moiety, 125I-VIP binding to IGR39 cell membranes was tested in the presence of soluble lectins. Among the lectins tested, only wheat germ agglutinin (WGA) was found to markedly inhibit VIP binding in a dose-dependent manner. Binding data indicated that the presence of the lectin led to a 3-fold increase in Kd value, from 0.15 to 0.44 nM, without any change in the number of available binding sites. The potent inhibitor of WGA binding, N,N',N"-triacetylchitotriose, completely reversed the effect of the lectin. On the other hand, VIP binding inhibition persisted even after neuraminidase treatment, suggesting that sialic acids were not directly involved. Furthermore, WGA inhibition was not abolished although most, if not all, VIP receptor oligosaccharides were converted to high mannose type structures by treating IGR39 cells with deoxymannojirimycin. Finally, whereas the pharmacological profile of VIP receptor was virtually identical, the presence of WGA greatly reduced the VIP-stimulated cAMP in IGR39 cells, indicating that the lectin alters the ability of the receptor to interact with the adenylate cyclase system.

Binding, Competitive↗
PubMed1992

Involvement of central dopamine and D1 receptors in stress-induced colonic motor alterations in rats.

The role of central versus peripheral influence of dopamine (DA) in the genesis of emotional stress (ES) induced by fear to receive electric footshocks on colonic motility was evaluated in rats equipped with implanted electrodes on the proximal colon. In control rats, the frequency of colonic spike bursts increased from 7.5 +/- 1.9 to 16.0 +/- 2.1 per 10 min when the rats were placed in a test box where they had previously received electric footshocks. This increase induced by ES was significantly p less than 0.05, reduced by previous ICV or IP administration of (+)SCH 23390 (a D1 receptor antagonist) at doses of 10 and 100 micrograms/Kg, respectively. Although sulpiride (a D2 antagonist) injected ICV or IP at similar doses had no effect on the ES-induced increase in the frequency of colonic spike bursts. DA (100 micrograms/kg), and the selective D1 (SKF 38383) or D2 (quinpirole) receptor agonist injected ICV at a dose of 5 micrograms/kg also increased significantly by 48.7, 54.8, and 68.7%, respectively, the colonic spike burst frequency whereas they are inactive when injected IP at similar and higher doses. These results suggest that, in rats, (a) emotional stress stimulates colonic motility through the stimulation of dopaminergic neurons involving D1 receptors and (b) exogenous activation of central D1 and D2 receptors similarly stimulate colonic motility by increasing the occurrence of colonic spike bursts.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1992

Modulation of the expression of the VIP receptor by serum factors on the human melanoma cell line IGR39.

IGR39 cells, isolated from a human superficial melanoma, display at their surface high and low affinity receptors for the vasoactive intestinal peptide (VIP). When grown in DME medium supplemented with 10% fetal calf serum, cells display 1.6 x 10(5) high affinity (Kd 0.74 nM) and 5.6 x 10(5) low affinity (Kd 55 nM) VIP binding sites per cell. When cultured in a chemically defined medium containing EGF, transferrin, and selenium, IGR39 cells display many neurite-like extensions. Following these morphological changes, the specific [125I]VIP binding is increased four- to fivefold after 6 days in culture. This phenomenon is reversible and is the result of an increased number of VIP binding sites available at the cell surface, without modification of their affinities. The molecular mass of the binding sites is also unchanged whatever cell culture conditions. Increase in [125I]VIP binding is inversely correlated to the serum concentration in the culture medium. When added to the chemically defined medium, sera from various origins as well as some serum substitutes reduce [125I]VIP binding to the same extent as that of the serum. The total cAMP production by VIP-stimulated IGR39 cells is enhanced by a factor of six to seven when cells are cultured in serum-free medium, in good correlation with the increase of VIP binding capacity. These data suggest that factor(s) present in fetal calf serum inhibit(s) the expression of VIP receptor, thus demonstrating the importance of a strict control of cell culture conditions for in vitro studies.

Binding Sites↗
PubMed1991

[Monitoring of small cell bronchopulmonary cancer by bronchial biopsies].

This retrospective study of 149 patients with small cell lung cancer highlights the value of bronchial endoscopies combined with biopsies for the follow-up of these cases. A control endoscopy performed during the third month showed that macroscopic lesions had completely disappeared in 42 percent of the patients. Each subsequent endoscopy offered a probability rising from 20 to 50 percent of diagnosing a recurrence in the patients explored. Our study particularly demonstrates the usefulness of bronchial biopsy at the initial site of the lesion, even when the bronchial mucosa seems to have returned to normal, since this biopsy is positive in 4.5 percent of the cases.

Adult↗
PubMed1990

[Environmental interstitial pneumonia caused by asbestos. Study of a Turkish family exposed to tremolite].

Environmental exposure to asbestos, as observed in Anatolia (Turkey), usually results in pleural pathology (plaques and mesothelioma). We report the case of a 50-year old woman who, until the age of 50, had lived in Eregli, central Anatolia, a region where inhalation of environmental asbestos is responsible for a high prevalence of pleural diseases. Radiology showed diffuse interstitial pneumonia without pleural involvement. Bronchoalveolar lavage brought back asbestos bodies (AB) in concentrations of 4,250 per millilitre. All were made of tremolite, a non-commercial variety of asbestos. The patient's family was investigated by chest radiography and search for AB in sputum. The husband, who came from the same town as his wife and had been exposed until the age of 45, had the classical response with bilateral pleural thickening but no parenchymal abnormalities; 2 AB were found in his sputum. The 3 sons, exposed for 10, 13 and 20 years respectively, had normal radiograms and no AB in their sputum, except for the older (3 AB) who had been exposed for 20 years. These cases illustrate the importance of environmental exposure to asbestos which may produce lesions similar to those observed in industrial exposure. Only mineralogical examinations can determine whether the asbestos is environmental or industrial.

Asbestos↗
PubMed1988

[Peripheral bronchopulmonary cancers. Diagnostic efficiency of fibroscopic samples. Prospective study on 561 patients].

The purpose of this french multicentric study was to evaluate the diagnostic accuracy of samples collected by fibroscopy in peripheral lung cancer with normal endoscopy. Five hundred and sixty-one patients entered the study; a tumour had been diagnosed in 350 of them (62 p. 100). Among these 350 patients, 147 were examined with the help of a light-amplifier screen, and a positive diagnosis was made in 97 (66 p. 100). Guided sample collection in the pathological area (biopsy, brushing, transcatheter aspiration) proved much more rewarding than unguided sample collection (biopsy of the bronchus, simple aspiration or cytology of 3-day sputum): 45 p. 100 positive results versus 18 p. 100 (P less than 0.001). However, sputum cytology still had good diagnostic value since it provided by itself the diagnosis in 14 p. 100 of the cases. Results were significantly inferior in tumours less than 3 cm in diameter.

Adult↗
PubMed1988

Influence of cadmium on the chain dynamics of collagen in rat tail tendon.

The molecular mobility of the chain dynamics of collagen was investigated by the thermally stimulated creep method on rat tail tendon after oral administration of cadmium (8 mg.kg-1.day-1) for six weeks. The high resolving power of the technique shows two manifestations of the pseudolathyrogen effect of cadmium: the polar side-chains of collagen, mobile in the immature specimen, which are cross-linked and so immobile in the mature specimen, remain mobile in the cadmium-treated mature specimen. There is also a subsequent decrease in the number of water molecules linked by two hydrogen atoms bound to the tropocollagen molecules. Probably these molecular modifications inhibit mineralization of the organic matrix and so osteogenesis.

Animals↗