Pharmacokinetics of the anxiolytic beta-carboline derivative abecarnil in the mouse, rat, rabbit, dog, cynomolgus monkey and baboon. Studies on species differences

The pharmacokinetics of abecarnil (isopropyl 6-(benzyloxy)-4-(methoxymethyl)-9H-pyrido [3,4-b] indole-3-carboxylate, ZK 112 119) were studied in the mouse, rat, rabbit, dog, cynomolgus monkey and baboon using 14C-labeled drug and HPLC with fluorescence detection for measurement of unchanged drug. Abecarnil was rapidly and completely absorbed after oral doses of 10 mg/kg. At higher doses, absorption was prolonged and incomplete in the cynomolgus monkey. The bioavailability of abecarnil was 20-30% in all the species investigated. The terminal half-life of the unchanged drug in plasma was relatively similar in all species (0.6-1.7 h). Abecarnil was able to pass the blood-brain barrier achieving concentrations in the brain similar to those in plasma. Tissue distribution of labeled compounds was rapid with highest concentrations in the liver, adrenals, kidneys and pancreas followed by the bone marrow, lungs, heart, fat, spleen, ovaries and thyroid gland. Excretion of radiolabeled compounds proceeded predominantly in the feces of the rat, the rabbit and the cynomolgus monkey.     

Ein Fragebogen zur infertilitätsbedingten Belastung andrologischer Patienten

The infertility distress scale (IBS) has been designed to assess the stress perceived by andrological patients resulting from infertility. This review presents findings from different studies with a total of 769 patients. The scale consists of eight items. The stability of scores is very high even for a mean follow-up of 2 years. The scale correlates highly with an already validated measure of infertility distress. Correlations with measures of depressiveness are in the low to medium range. All in all, the psychometric results indicate that the IBS is a factor-stable, reliable and valid instrument for assessing chronic infertility distress in andrological patients. After the presentation of normative data, the usefulness of the IBS as a screening instrument for identifying highly distressed patients is discussed. Findings supporting the scale's sensitivity to change are also presented. The scale is a useful tool in clinical practice as well as in research.     

THE EFFECT OF HYPERTENSIVE EPISODES AND CARDIAC HYPERTROPHY ON THE CANINE CARDIAC BAROREFLEX

1. Left ventricular (LV) hypertrophy has been implicated in the reduction of baroreflex sensitivity present in hypertension. The aim of the current study was to investigate the mean arterial pressure-heart rate reflex (MAP-HR) in a model which induced left ventricular hypertrophy but no sustained blood pressure elevation. 2. Five mongrel dogs were exposed to transient blood pressure elevation of between 20 and 30 mmHg, through hindlimb compression using a pneumatic pressure suit, for 7 h per day, 6 days per week for 6 weeks. Resting blood pressure was not altered by the 6 week hindlimb compression intervention. 3. Echocardiographically determined LV mass (mean ± s.e.m.) was 116.0 ± 7.4 g prior to hindlimb compression (baseline) and elevated to 125.4 ± 8.1 g (P= 0.003) after 6 weeks of compression. A reduction in the early (E) to late (A) transmitral diastolic flow ratio (E/A) from 1.80 ± 0.06 at baseline to 1.54 ± 0.09 (P = 0.037) after the 6 week intervention suggested that cardiac compliance was reduced. 4. The maximum gain of the MAP-HR reflex, studied using the ‘steady-state’ drug technique, when blood pressure was normal, showed a trend for reduction from 3.85 ± 0.43 beats/min per mmHg at baseline to 3.10 ± 0.45 beats/min per mmHg (P= 0.067) after 6 weeks of compression. This gain reduction became significant after β-adrenoceptor blockade with propranolol (3.13 ± 0.55 vs 2.32 ± 0.25 beats/min per mmHg; P= 0.039). Covariant analysis showed a significant inverse correlation between LV mass and maximum gain (r= 0.96; P<0.001) during the 6 week compression period. 5. The MAP-HR reflex changes in this model mimic those present in hypertension and implicate cardiac hypertrophy as one possible mediator.     

Risk of acquiring influenza A in a nursing home from a culture-positive roommate.

Influenza A was cultured in 62 double rooms. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (CI95, 1.61-5.78) of acquiring influenza.     

Gd-DTPA-cascade-polymer: Potential blood pool contrast agent for MR imaging

Gadolinium-DTPA (diethylenetriaminepentaacetic acid)-cascade-polymer, a potential new blood pool contrast agent for magnetic resonance (MR) imaging, was compared with a known blood pool agent, Gd-DTPA-polylysine, in an animal model. The relative signal intensities of liver, renal cortex, pancreas, and trunk muscle were assessed in 12 pigs between 4 seconds and 120 minutes after injection of a 20 μmol/kg dose of each contrast agent, by using a FLASH (fast low-angle shot) sequence. Except for muscle, all tissues showed visible enhancement after injection of either contrast agent. After injection of Gd-DTPA-polymer, enhancement patterns in the liver, renal cortex, and pancreas were similar to those seen after injection of Gd-DTPA-polylysine. No statistically significant differences in enhancement between the two contrast agents were found at any time point. The authors conclude that the contrast kinetics of Gd-DTPA-cascade-polymer are similar to those of Gd-DTPA-polylysine and that this agent may also be used as a blood pool contrast agent for MR imaging.