Metabolism of lofepramine by rat liver microsomes

1. The metabolism of lofepramine in vitro by rat liver microsomes was studied. The enzyme system involved was dependent on cytochrome P-450 and the main metabolites were desmethylimipramine (DMI), formaldehyde and p-chlorobenzoic acid. 2. Microsomes from rats pretreated with phenobarbital or 3-methylcholanthrene showed enhanced lofepramine metabolizing activity. The induction was reflected in increased Vmax values, whereas Km values were not changed. 3. Pretreatment of rats with lofepramine or DMI did not alter the rate of aniline hydroxylation, aminopyrine demethylation or lofepramine metabolism per mg microsomal protein. Nor was the amount of cytochrome P-450 changed. 4. Lofepramine, imipramine and DMI inhibited competitively the microsomal hydroxylation of aniline in vitro. Lofepramine was the most potent inhibitor, which probably reflects the higher lipophilicity of this compound.

Computed tomography, angiography and ultrasound in staging of renal carcinoma

Preoperative evaluation of the extent of the renal tumor is of value in determining the prognosis of the patient and the most suitable therapy. CT and angiography were reviewed in 27 cases of renal carcinoma to evaluate tumor involvement of lymph nodes, renal vein, vena cava, and the perinephric space. In 26 of these cases the ultrasound examination was similarly reviewed. Comparison of ultrasound, CT, and angiography demonstrated that staging of renal tumors with ultrasound is mainly limited by its inability to demonstrate extrarenal infiltration. Both CT and ultrasound proved reliable in the demonstration of tumor spread to the renal vein and inferior vena cava. CT and angiography were equally effective in the evaluation of tumor extension; since CT is easier to perform, less invasive and less time consuming than angiography it should be the primary method for staging of renal neoplasms. Angiography offers detailed information on the vascular supply of the tumor important for the choice of surgical approach and should be performed only on special indications.

Dynamic interferometry techniques for optical path length measurements

Two dynamic interferometric techniques based on electrically tunable lasers are described and experimentally demonstrated. The first technique allows for measurements of small phase modulations in interferometers independently of dc drifts and low frequency noise in the interferometer. The second scheme is a true FM technique suited for continuous real-time noncontact measurements of the optical thickness of transparent materials.

Effect of quinidine on maintaining sinus rhythm after conversion of atrial fibrillation or flutter. A multicentre study from Stockholm

In a controlled study comprising 176 patients, quinidine in the form of Kinidin Durules was found to reduced significantly the recurrence of the atrial fibrillation during a 1-year follow-up period after successful electric shock conversion. After one year, 51 per cent (52/101) of the patients in the quinidine group, and 28 per cent (21/75) in the control group remained in sinus rhythm (P smaller than 0.001). No less than 43 per cent of the patients converted to sinus rhythm during treatment with maintenance doses of quinidine sulphate before intended DC conversion. Gastrointestinal side-effects were not uncommon, and caused interruption of quinidine treatment in some cases.