Haemodynamic effects of atenolol in patients with coronary artery disease

The haemodynamic effects of atenolol, a new cardioselective beta-blocking agent, have been studied at rest in 8 patients with coronary artery disease. The drug was administered intravenously in cumulative doses of 0.03, 0.06, and 0.12 mg/kg body weight. A significant decrease in heart rate was associated with a fall in cardiac output. However, this cardiac output fall was not entiely rate dependent, since stroke volume fell significantly both during spontaneous sinus rhythm and when heart rate was maintained constant by atrial pacing. A dose related and significant reduction occurred in left ventricular dP/dt max without significant change in left ventricular filling pressure or mean aortic pressure. Total peripheral resistance at rest rose after atenolol. The haemodynamic findings more closely resemble those which follow intravenous propranolol than those after intravenous practolol in a similar group of patients. These actions of atenolol suggest that it may be a useful agent in the treatment of patients with angina pectoris.

Clinical electrophysiological effects of atenolol--a new cardioselective beta-blocking agent

Atenolol, a cardioselective beta-blocking agent, at dose levels of 0.03, 0.06, and 0.12 mg/kg intravenously, produced prolongation of atrioventricular nodal conduction in 22 patients with suspected coronary artery disease. In a dose of 0.12 mg/kg body weight atenolol produced significant prolongation of sinus cycle length, sinus node recovery time, atrioventricular node conduction, and the effective and functional refractory periods of the atrium and the atrioventricular node. No significant effects were observed on the His Purkinje system or the effective refractory periods of the ventricle. In these actions atenolol closely resembles propranolol. However, because in contrast to propranolol it increases atrial refractoriness, it may have advantages in the treatment of atrial arrhythmias.

Changes in amino-acid composition of developing rat incisor enamel

The amino-acid composition and total "protein" content of enamel particles dissected serially from the developing enamel of rat incisors have been determined. Changes in protein content and amino-acid composition occurred throughout all stages of development. The most obvious alterations occurred in the vicinity of a white opaque band. Here, protein was lost most rapidly and considerable changes in amino-acid composition occurred.

Recent changes in the emotional reactions of therapeutic aboriton applicants

The emotional status of one hundred women applying for therapeutic abortions during 1967/68 was compared with that of 100 more recent applicants in 1975. The Minnesota Multiphasic Personality Inventory of the two groups reveals a significant reduction in psychopathology amongst the more recent applicants. This difference remains when group differences in age are controlled, and applies when married and single subgroups are considered separately. These results are interpreted as suggesting that the generally more liberal social atmosphere surrounding present-day abortions is reducing psychological stress among women undergoing this procedure.

Degradation of porstaglandin F2alpha in the human pulmonary circulation

Degradation of prostaglandins (PGs) during passage through the human pulmonary circulation was investigated by measuring the transpulmonary plasma PGF2 alpha difference during continuous intravenous infusion of PGF2 alpha (5-10 mug/min). Seven patients with cardiological disorders and two patients with extensive pulmonary abnormalities were investigated during diagnostic cardiac catheterization. PGF2 alpha levels were measured by radioimmunoassay. The seven cardiac patients were found to have transpulmonary PGF2 alpha differences of 47-88%, indicating metabolism of the PG in the lungs. A patient with extensive bronchiectasis had an apparently normal transpulmonary PGF2alpha difference despite gross abnormalities in routine lung function tests. A patient with primary pulmonary arterial hypertension showed no metabolism of PGF2alpha in the pulmonary circulation. The results show that PG degradation is an aspect of normal lung function and suggest that it becomes imparied when extensive pulmonary vascular damage exists.

Arrest and control of carious lesions: a study based on preliminary experiments with resorcinol-formaldehyde resin

An experimental investigation has been made into the possibilities of retarding the progress of carious attack by infiltrating cariostatic material into enamel lesions. The problems associated with this kind of procedure are discussed against the background of experimental observations made using a formulation based on a resorcinol-formaldehyde resin.

Variations in the composition of developing rat incisor enamel

The developing enamel of rat incisors was dissected into a series of samples extending from the newly-formed partially-mineralised matrix to the mature.enamel. Chemical analysis showed that, on a dry weight basis, the tissue achieved the composition of mature enamel well before the completion of mineral uptake. The enamel at this stage was porous and relatively soft. As more mineral was acquired, its hardness increased. Throughout the developing region, the Ca:P ratio remained fairly constant, but the CO2:P and Mg:P ratios both decreased due, apparently, to dilution by an influx of relatively C02- and Mg-free mineral.