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Biomedical subjects

R Leandri

Publications and source records attributed to R Leandri.

9 recordsLinked to original sources
PubMed1989

Kinetics of adriamycin injected proximal to a tumor: a comparative study between venous and arterial injections.

A kinetic study of plasma concentration of Doxorubicin (Adriamycin) was performed in 25 cases of malignant melanoma of the extremity with malignant adenopathy, treated with the same dose (20 mg per m2). Drug concentration was measured using a radioimmunoassay, with good intra-assay and inter-assay reproducibility. The kinetic analysis used the multiple compartmental method and a simulation of the plasma curves. Adriamycin injected intravenously quickly leaves the plasma into an exchangeable compartment with a slow plasma return and subsequent prolonged mean duration of the plasma half life at a low concentration. Thus, the intravenous perfusion results in a high plasma concentration only during the time of infusion. After intra arterial injection proximal to the tumor, a fraction variable (average 35%) is not released back into the circulation, or released very slowly. This local sequestration (important in terms of local concentration) explains the efficiency and the potential local toxicity of this method of administration. The rapid release of about 70% of the drug into the plasma, with kinetics similar to that observed after intravenous infusion, allows for no significant reduction of systemic toxicity.

Adult↗
PubMed1986

[Effect of somatostatin on the rabbit Oddi's sphincter in vivo. Interrelation of somatostatin and cholecystokinin].

The action of somatostatin on the myoelectrical activity of the sphincter of Oddi was studied in anesthetized rabbits equipped with bipolar electrodes. The activity of the sphincter was recorded at the basal state and during 30 min after injection of somatostatin. After a bolus injection of somatostatin (1 to 8 micrograms/kg), the myoelectrical activity of the sphincter of Oddi decreased between the 2nd and the 10th min with a parallel decrease of the biliary pressure. These modifications were significant at the doses of 4 and 8 micrograms/kg only. There was a good dose-effect relationship. Moreover, the infusion of somatostatin (60 micrograms/kg/h) led to a decrease in sphincter activity. Bolus injection of cholecystokinin (2 UD/kg) under somatostatin infusion (60 micrograms/kg/h) induced an increase in the activity of the sphincter of Oddi. However, this activity never returned to basal levels.

Ampulla of Vater↗
PubMed1981

Surgical treatment of ventricular tachycardia guided by ventricular mapping in 23 patients without coronary artery disease.

Twenty-three patients with resistant ventricular tachycardia not related to coronary artery disease underwent surgical treatment guided by ventricular mapping. The patients were grouped according to radiological and anatomical findings. Group 1 (13 patients) had arrhythmogenic right ventricular dysplasia. Group 2 (3 patients) had left ventricular aneurysm. Group 3 (2 patients) had nonobstructive myocardiopathy. Group 4 (5 patients) had normal-appearing hearts. At operation all patients underwent ventricular mapping when in sinus rhythm and during ventricular tachycardia. The rationale of operation was ventriculotomy or cryosurgery at the site of origin of ventricular tachycardia or exclusion, resection, or undermining of arrhythmogenic areas where delayed potentials were observed. Four patients died during the perioperative period, 3 of low-output failure and 1 from bleeding. Ventricular tachycardia recurred immediately after operation in 4 patients, 3 of whom died during the perioperative period. Ventricular tachycardia recurred late in 5 patients. Three had only episodic, unsustained runs of tachycardia. Two were well controlled by drugs. All patients with ventricular tachycardia situated over the free wall of the ventricles had inducible ventricular tachycardia and had good surgical results. Three out of 5 patients with ventricular tachycardia situated in the septum had poor surgical results. Septal ventricular tachycardia needs a better surgical approach to the septum and a suitable surgical concept.

Adult↗