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Biomedical subjects

B Coudert

Publications and source records attributed to B Coudert.

At least 37 records · Page 2Linked to original sources
PubMed1987

Amiodarone is more efficient than verapamil in reversing resistance to anthracyclines in tumour cells.

We have previously demonstrated that amiodarone is able to reverse resistance of rat colon cancer cells to anthracyclines. We now compare the efficiency of amiodarone to verapamil one, another antiarrhythmic agent used in experimental systems and in clinical trials to enhance the effects of anthracyclines on resistant cancer cells. Amiodarone is more efficient than verapamil when both drugs are used at the same molar concentrations. Desethylamiodarone, the main metabolite of amiodarone, is as efficient as its precursor. Optimal concentrations of amiodarone are obtained without side effects in the sera of patients treated by oral administration followed by a loading infusion of amiodarone. On the other hand, maximal tolerated levels of verapamil reported in clinical trials are less efficient than amiodarone maximal levels in the reversal of resistance to anthracyclines in our experimental model in vitro. We suggest that amiodarone, which is more efficient and less toxic than verapamil, could be substituted for verapamil in future clinical trials.

Adenocarcinoma↗
PubMed1987

[Tricuspid endocarditis with right-left auricular shunt through a patent foramen ovale].

The authors report the case of a tricuspid endocarditis secondary to Streptococcus bovis with important regurgitation and severe hypoxemia secondary to a right-left atrial shunt through a patent foramen ovale, requiring a surgical treatment which included the replacement of the tricuspid valve and closure of the dehiscence in the inter-atrial septum. The presence of a patent foramen ovale in the course of a tricuspid endocarditis has been exceptionally reported. This diagnosis deserves to be evoked in case of an unexplained hypoxic condition or a systemic embolism complicating a tricuspid endocarditis. The report emphasizes the advantage of ultrasonic examinations (contrast sonocardiography, pulsated Doppler) in order to demonstrate this right-left atrial shunt in addition to the data collected about the tricuspid valve.

Adult↗
PubMed1986

[Congenital paravertebral arteriovenous fistulae in children and adolescents].

These arteriovenous fistulae (AVF) situated in the paravertebral area present as a murmur which explains their cardiological orientation. They are characterised by the presence of one or more afferent paravertebral arteries giving rise to collateral vessels irrigating the bone marrow. The aim of this study of 13 cases was to study the diagnostic and therapeutic problems, and the evolution of this particular localisation of AVF. Two groups of paravertebral AVF were individualised: - Cervical AVF in which the vertebral artery was always involved (7 cases). Four were simple (only one fistula) and three were complex, having several afferent arteries. Two presented as a rapidly growing vascular tumour. Two caused an asymptomatic angiographic vertebral steal syndrome. Two simple forms were obturated by a detachable balloon and one by surgical excision. Two complex forms were treated by embolisation and surgery. Total closure of the AVF was obtained in all cases without complications. - Dorso-lumbar AVF (6 cases). The afferent vessels are the intercostal (D6 to D8) or lumbar (L2 to L4) arteries. Anatomically, these are extra-medullary fistulae with an extra or intra-vertebral venous drainage. Enlargement in an adjacent conjugating foramen forms a tumour which may narrow the spinal canal (1 case diagnosed by CAT) or erode the vertebral body, so compromising the spinal support. Spontaneous closure of the AVF was observed in 1 case. Three cases were treated surgically with good results; two patients are waiting for embolisation. A review of the literature provides complementary information on the long-term evolution of these AVF and confirms the need for systematic therapy as demonstrated in our study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Serum concentrations of amiodarone required for an in vivo modulation of anthracycline resistance.

We demonstrated previously that amiodarone is able to circumvent in vitro the inherent resistance to anthracyclines of the DHD/K12 rat colon cancer cell line. We have now determined in the rat the amiodarone seric concentrations required to enhance the in vitro cytotoxicity of 4'-deoxydoxorubicin (deoDX) against DHD/K12 cells. A maximal deoDX potentiation was obtained in vitro when anthracycline was diluted in the serum of rats receiving at least 75 mg/kg of intravenous amiodarone resulting in seric concentrations of more than 40 micrograms/ml. In patients treated with amiodarone, the mean serum concentrations were 0.9 +/- 0.1 microgram/ml after an one month's oral administration of 200 mg/day, 2.2 +/- 1.0 micrograms/ml after a 24 hr continuous infusion of 300 to 900 mg/day and 5.4 +/- 1.1 micrograms/ml after a brief 3 hrs infusion of 450 mg amiodarone. Such amiodarone concentrations in human serum are much lower than those necessary to produce a significant anthracycline potentiation. In rats receiving amiodarone at a maximal tolerated dose (100 mg/kg) minutes before the injection of 10 mg/kg doxorubicin (DX), we observed an increased accumulation of the anthracycline in the liver and kidney compared to rats receiving DX alone. The DX content was not modified by amiodarone in the other organs studied (heart, lung, spleen and pancreas). An amiodarone pretreatment accelerated the death of rats receiving 5 or 10 mg/kg DX did not provoke lethality for a lower dose of 2.5 mg/kg DX. The very high doses required and the risk of increased toxicity seem to preclude the use of amiodarone for the modulation of anthracycline resistance in cancer patients.

Adjuvants, Pharmaceutic↗
PubMedDate not supplied

[Drug-induced respiratory complications. Study of 27 cases].

Over 8 1/2 years, we observed 27 patients with drug-induced respiratory disease (DIRD). The inducer drugs were mainly those used in cardiology (9 patients, of whom 8 had amiodarone pneumonitis), in oncology (8 patients), in rheumatology (4 patients; 3 from d-penicillamine and 1 from gold), and in neurology (4 cases from ergoline derivatives). The main pattern of DIRD was a diffuse interstitial lung disease having either a rapid, a slowly progressive or a chronic course. Only the two former patterns offered clearing following withdrawal of the drug. Severe bronchiolitis obliterans from d-penicillamine (2 cases) and pulmonary eosinophilia (2 cases) was also observed. The onset of DIRD occurred earlier, i.e. following shorter periods of drug administration (months), in the acute interstitial lung disease variant, while it occurred after years of drug exposure in subacute and chronic forms. In contrast to other reports, bronchoalveolar lavage lymphocytosis was not a prominent feature in amiodarone pneumonitis. The outcome was favourable in 16 patients; deaths was encountered during the florid phase of DIRD in 3; incapacitating sequelae were noted in 6 patients, leading to subsequent death in 2; the underlying disease accounted for 7 additional deaths. Therefore, DIRD are relatively common, develop often in patients with severe underlying conditions, and interstitial pneumonitis is their pattern of predilection. Amiodarone emerges as a common inducer, and accounted for more cases than all chemotherapeutic agents grouped together in our series.

Adult↗