Failure of nitric oxide donors to alter arrhythmias induced by acute myocardial ischaemia or reperfusion in anaesthetized rats.

1. The aim of the present studies was to examine the effects of nitric oxide donors on arrhythmias induced by coronary artery occlusion and reperfusion, and on cardiac cyclic nucleotides. Experiments were performed in pentobarbitone-anaesthetized rats prepared for occlusion of the left coronary artery. 2. Sodium nitroprusside (0.1, 0.3 and 1 microgram kg-1 min-1) had no significant effects on the incidence of ventricular tachycardia, total ventricular fibrillation or the mortality resulting from 25 min of acute myocardial ischaemia when compared with values in controls. In addition, there was no alteration in the number of ventricular premature beats that occurred in survivors. 3. 3-Morpholinosydnonimine-N-ethylcarbamide (SIN-1, 10, 20 and 40 micrograms kg-1 min-1) caused marked hypotension but did not alter the incidence or severity of ischaemia-induced arrhythmias. In rats subject to abrupt reperfusion after 5 min of myocardial ischaemia, lower doses of SIN-1 (1, 3 and 10 micrograms kg-1 min-1) still caused significant reductions in systolic and diastolic blood pressure but were devoid of antiarrhythmic activity. 4. In separate experiments in sham-operated rats, sodium nitroprusside (1 microgram kg-1 min-1), isosorbide dinitrate (30 and 60 micrograms kg-1 min-1) and SIN-1 (20 and 40 micrograms kg-1 min-1) had no significant effects on cardiac cyclic GMP content. 5. These results indicate that nitric oxide donors do not alter arrhythmias induced by acute coronary artery occlusion or reperfusion in anaesthetized rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interaction of active and passive slow eye movement systems

Summary Independent target and background motions have been used to generate conflicting activity within the pursuit and optokinetic systems. Subjects were required to pursue a small target against a structured background which moved independently. Selective enhancement of the response to the target generated high-gain active pursuit which dominated the eye movements. Passive eye movements induced during relative target and background motion are not normally directly quantifiable due to their low gain. By reducing the gain of the active pursuit optokinetically induced eye movements were enhanced and quantified. Three techniques are described for degrading active pursuit: tachistoscopic, eccentric and pseudorandom methods of target presentation. Our results demonstrate the synchronous input of active and passive eye movement drives to the oculomotor system and illustrate their interaction.     

Evaluation of a hand-held spirometer, the Respiradyne, for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR)

A hand-held spirometer, the Respiradyne (R), was evaluated for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) by comparing it with a Vitalograph spirometer (V) and a Wright's peak flow meter (W) in 70 subjects (normals and patients). The results showed close agreement for FEV1; r = 0.99, R = 0.961V + 0.03 X 10(-5) and FVC; r = 0.99, R = 1.003V-0.044. Results for PEFR using the Respiradyne were generally higher than with the peak flow meter; r = 0.98, R = 1.151W-17.576. The Respiradyne is portable and simple to operate and may be suited to use in a variety of non-laboratory situations.     

Stability of bendrofluazide in a low-dose extemporaneously prepared capsule

The stability of bendrofluazide 1.25 mg in capsules was studied. The formulation is intended to provide a unit dose powder for administration by dispersing the contents in liquid. The capsules were prepared from ground bendrofluazide tablets 5 mg from two different manufacturers, diluted with lactose and packed manually by weight into hard gelatin capsule shells. The capsules were stored at ambient temperature exposed to light or 75% relative humidity, and at 45 or 60C. The ambient temperature and 60C conditions were studied for up to 1 year. Bendrofluazide was determined by a stability-indicating HPLC method. The capsule contents remained easy to disperse in liquid by the end of the study. The weight of contents which could be extracted from the capsules also remained satisfactory. A 7-month storage life at ambient temperature would be feasible, based on the lower 95% confidence limits of the time to 5% degradation.     

Incontinence and troublesome behaviors predict institutionalization in dementia.

Factors predicting the early institutionalization of demented patients were studied in 143 outpatients using univariate and multivariate life-table methods. Four types of factors were evaluated for prognostic value: severity of functional impairment, behavioral disorders, individual patient characteristics, and type of caregiver. After follow-up of 19 +/- 12 months, 51 patients had been institutionalized. Increased global severity of dementia, the presence of troublesome and disruptive behaviors, and incontinence increased the likelihood of institutionalization. The best predictors of institutionalization were paranoia, aggressive behavior, and incontinence. Neither individual patient characteristics (age, education, and gender) nor caregiver relationship to the patient (male spouse, female spouse, and male or female child) influenced institutionalization. Since troublesome behavioral disorders are potentially treatable aspects of dementia leading to institutionalization, their management should be a major focus of therapy in dementia.     

Ein Beitrag zur aktuellen Antidementivadiskussion in Deutschland

In Germany, the role of acetylcholinesterase inhibitors in the treatment of Alzheimer’s disease (AD) has become a topic of recent discussion. The present article addresses issues which, in the opinion of the authors, have not received sufficient attention. These include the distinction between statistical and clinical significance, outcome parameters, the duration of clinical trials, variability in treatment response and the definition of treatment responders. The authors argue that these issues need to be considered in an in-depth evaluation of acetylcholinesterase inhibitors in the treatment of AD.