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Biomedical subjects

C Robinson

Publications and source records attributed to C Robinson.

At least 451 records · Page 25Linked to original sources

Matrix and mineral changes in developing enamel.

An investigation of the changes taking place in the enamel and the enamel organ during enamel development has been carried out by analyzing small samples of tissue dissected from developing incisors of rat and bovine incisors. Observations showed that the synthesis of the enamel matrix and its subsequent loss were associated chiefly with a change in the major matrix components. This consisted of a selective loss of amelogenin components prior to secondary mineralization. Before this loss, some increase in the proportion of smaller molecular weight components suggested the possibility of limited breakdown. Even at the earliest stages examined, significant concentration of mineral ions was present. This increased steeply after most of the organic matrix had been removed. The Ca/P ratio of this mineral was constant throughout development. The concentration of minor inorganic ions (F, Mg and CO3) decreased as the tissue developed and a tendency was observed for certain ions (F, 32PO4) to penetrate and concentrate in the enamel, apparently as a consequence of the lost matrix being replaced by water, just prior to the steep increase in mineral content of the tissue.

Amelogenesis↗

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.

Atenolol↗

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.

Adult↗

Comparison of atenolol with propranolol in the treatment of angina pectoris with special reference to once daily administration of atenolol.

Fourteen patients with angina pectoris completed a double blind trial of atenolol 25 mg, 50 mg, and 100 mg twice daily and propranolol 80 mg thrice daily. In comparison with placebo, all active treatments significantly reduced anginal attacks, consumption of glyceryl trinitrate, resting and exercise heart rate, resting and exercise systolic blood pressure, and significantly prolonged exercise time. There was no significant difference between the effects of propranolol and atenolol. Nine patients completed a further trial comparing atenolol given once or twice daily. Both regimens were effective and there was no significant difference between the reductions in anginal attacks, glyceryl trinitrate consumption, systolic blood pressure, or heart rate. Twenty-four-hour ambulatory electrocardiograms showed that atenolol consistently reduced heart rate throughout the 24-hour period whether given once or twice daily. Atenolol is a potent antianginal agent which, in most patients, is likely to be effective once daily.

Adult↗

Mental health training and consultation: a model for liaison with clergy.

A chaplain, a psychiatrist, and a social worker developed a program to train clergy in more effective mental health case management, counseling, and referral skills, and to sensitize mental health center professionals to the work of the clergy in mental health. The program consists of 12 two-hour meetings conducted by a clinician and a chaplain once a week. In the first four meetings, clergy are trained to use a self-report personal-data kit with individuals presenting with emotional problems. In the next eight meetings, clergy make case presentations that are used as a basis for consultation and group discussion. The project has established a firm basis for collaboration between clergy and mental health center staff in providing care.

Community Mental Health Services↗

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.

Amino Acids↗