Class III antiarrhythmic activity of novel substituted 4-[(methylsulfonyl)amino]benzamides and sulfonamides.

The synthesis and Class III antiarrhythmic activity of a series of 4-[(methylsulfonyl)amino]benzamides and sulfonamides are described. Selected compounds show a potent Class III activity and are devoid of effects on conduction both in vitro (dog Purkinje fibers) and in vivo (anesthetized dogs). Compounds having a 2-aminobenzimidazole group were found to be the most potent, and one compound having this heterocycle (5, WAY-123,398) was selected for further characterization. Compound 5 was shown to have good oral bioavailability and a favorable hemodynamic profile to produce a 3-fold increase of the ventricular fibrillation threshold and to terminate ventricular fibrillation, restoring sinus rhythm in anesthetized dogs. Voltage-clamp studies in isolated myocytes show that 5 is a potent and specific blocker of the delayed rectifier potassium current (IK) at concentrations that cause significant prolongation of action potential duration.     

Clinical diagnostic criteria for TMD. New classification permits multiple diagnoses.

One of the first to permit multiple diagnoses, this new TMD classification scheme offers guidelines for clinicians and those conducting clinical field studies. The scheme was applied to a TMD population, with control subjects.     

Gender differences in cardiovascular risk factors in a carotid endarterectomy population.

AIM: Present knowledge about the epidemiology and the distribution of the cardiovascular risk factors of carotid artery atherosclerosis is limited. The aim of the study was to detect possible gender differences in cardiovascular risk factors in carotid endarterectomy patients. METHODS: Between 1998 and 2003 the cardiovascular risk factors of 804 consecutive isolated carotid endarterectomies were prospectively recorded. The data of 567 men and 237 women were compared and subgroup analysis of young and old male and female subjects was performed. RESULTS: The number of cardiovascular risk factors per patient is higher in men, hypertension is more predominant in women, tobacco use is twice as often present in men. The most frequent risk factors are, in men, tobacco use and hypertension, and, in women, hypertension and hyperlipidemia. The most frequent combination in the male group is tobacco/hypertension/hyperlipidemia and in the female group hypertension/hyperlipidemia. The gender differences were more striking in patients younger than 75 years, after this age the number of cardiovascular risk factor per patient declined in both sexes, the number of smokers decreased but remains higher in men, diabetes is more frequent in women and hypertension and hyperlipidemia become the important risk factors in men as well in women. CONCLUSIONS: There are gender differences in the distribution and in the combinations of cardiovascular risk factors in our selected patients. These findings suggest that screening for carotid artery atherosclerosis should particularly be aimed at people with the combinations of risk factors described above.     

Update on the management of obesity

This article updates a paper published in this journal more than a decade ago. We detail the ensuing decade's developments in the treatment of obesity, reviewing innovations, established techniques, and the current status of behavior modification. We evaluate newer developments, such as anorectic drugs, very low calorie diets, and intragastric balloon bezoars, and we describe other approaches to the treatment of obesity, such as residential and comprehensive outpatient programs. We conclude by recommending a multidisciplinary approach to this complex problem.     

How often do asymptomatic healthcare workers cause methicillin-resistant Staphylococcus aureus outbreaks? A systematic evaluation.

A systematic search was performed to identify outbreaks of methicillin-resistant Staphylococcus aureus infection and colonization caused by healthcare workers (HCWs). Of 191 outbreaks identified, 11 had strong epidemiological evidence that HCWs were the source. In 3 of these outbreaks, asymptomatic carriers were the cause. The frequent practice of screening asymptomatic HCWs should be reconsidered.     

A phase I clinical and pharmacokinetic study of the topoisomerase I inhibitor topotecan (SK&F 104864) given as an intravenous bolus every 21 days.

Topotecan (SK&F 104864) is a novel antitumor agent whose mechanism of action is inhibition of the DNA unwinding protein topoisomerase I. An analog of camptothecin, topotecan was designed to be more water soluble in an effort to decrease the severe and sporadic toxicities experienced during phase I/II trials of the parent compound. In this phase I clinical and pharmacological trial, topotecan was given as a bolus intravenous (i.v.) infusion over 30 min every 21 days. A total of 42 patients entered the study, receiving doses ranging from 2.5 to 22.5 mg/m2. The maximum tolerated dose (MTD) of topotecan given in this schedule was 22.5 mg/m2. Myelosuppression, primarily neutropenia, was dose-limiting. The extent of prior therapy did not predict for more severe neutropenia. Non-hematologic toxicities were mild and included low-grade to moderate fever, nausea, vomiting, alopecia, diarrhea and skin rashes. There were no objective partial or complete responses, although there was a suggestion of antitumor activity in three patients. Topotecan undergoes pH-dependent hydrolysis of the lactone ring; only the closed, lactone form is active. The lactone form predominated during infusion, with hydrolysis occurring rapidly following the end of infusion. There were linear relationships between dose administered and peak plasma lactone concentrations as well as AUC lactone to AUC total. The lactone was rapidly cleared from plasma with a total body clearance of 25.7 (+/- 6.7) l/h/m2. The plasma lactone concentration declined rapidly with a harmonic mean terminal half-life of 3.4 (+/- 1.1)h. Lactone hydrolysis and renal excretion were the major routes of elimination.(ABSTRACT TRUNCATED AT 250 WORDS)     

Flow cytometry of transitional cell carcinoma of the urinary bladder: influence of prior local therapy

A review of acridine-orange DNA and RNA flow cytometry (FCM) histograms of 249 bladder irrigation specimens from 129 patients with a previous history of transitional cell carcinoma (TCC) reveals that aneuploidy and tetraploidy (greater than 10% of total cell population) are reliable markers to detect the presence of bladder tumor in patients treated by surgical resection of tumor only. Tetraploidy is unreliable when the patient received intravesical chemotherapy or radiation therapy but aneuploidy remains accurate. A comparison of the reliability of FCM compared with cytology indicates an overall lower sensitivity and specificity for FCM (respectively, 52% and 73%) as opposed to cytology (respectively, 62% and 92%). Sensitivity is improved and raised to 77% if FCM and cytology are used in conjunction and reaches 82% in patients treated by surgery only and 88% in those who received radiation therapy. The lowest sensitivity and specificity obtained with FCM are in patients treated by intravesical chemotherapy (respectively, 44% and 58%) and the highest are in those treated by surgery without additional therapy (56% and 83%). This study demonstrates that FCM criteria for diagnosis of TCC of urinary bladder on bladder irrigation specimens depends on patient's treatment history. It also indicates that sensitivity and specificity of cytology to detect bladder tumor are superior to those obtained with FCM but both methods may be considerably improved if they are used in conjunction.     

The modulation by 3,5,3'-triiodothyronine (T3) of pituitary T3 nuclear receptors in hypothyroid rats is inhibited by cycloheximide

The density of T3 nuclear receptors is known to vary with tissues and physiopathological conditions, but the factors involved in their regulation are still unknown. We have previously shown in the anterior pituitary gland that T3 modulates its own receptors; the density of T3 receptors in hypothyroid rats is half that in normal rats, and one injection of T3 is able to restore normal density of T3 receptors within 1-3 h. To determine whether T3 has a direct action on the synthesis of its nuclear receptor, the effect of cycloheximide (Cy) on T3-induced nuclear receptor was studied. In addition, the relationship between the density of pituitary T3 receptors and the secretion of TSH in different thyroid states was examined. In normal rats one injection of Cy (0.5-8 mg/100 mg BW) induced within 3 h a dose-dependent reduction in the density of pituitary T3 receptors as well as an important decrease in plasma TSH, with no changes in T4, T3, or pituitary TSH content. In hypothyroid rats the 50% decrease in the density of pituitary T3 receptors was not further reduced by 1 mg Cy. However, when the same dose of Cy was given 30 min before T3 it completely inhibited the induction by T3 of its receptors. When Cy was given 30 min or 1 h after T3 the inhibition was only partial. An inverse correlation was found between the density of T3 receptors in the pituitary gland and plasma TSH (r = -0.8128) in all experimental groups except those treated with Cy; this drug had an inhibitory effect on both TSH secretion and the density of receptors. The present data, therefore, support the view that T3 in the pituitary gland may induce the synthesis of its own nuclear receptors and that the density of T3 receptors is also involved in the control of TSH secretion.