The effect of mental arithmetic in normotensive and hypertensive subjects, and its modification by beta-adrenergic receptor blockade.

1 The effects of a 5-min period of sustained mental arithmetic upon blood pressure and heart rate were determined in several groups of healthy subjects and hypertensive patients. 2 The arithmetic produced significant increases in heart rate and blood pressure (both systolic and diastolic) in both normotensive and hypertensive subjects. 3 The blood pressure changes were neither attenuated nor enhanced by the prior administration of basis. 4 In subjects habituated to the test the heart rate increase was unaffected by the drugs, but in those less familiar with the test it was usually attenuated. 5 Although the beta1-adrenoceptor selective blocker, metoprolol, caused decreases in baseline values for blood pressure and heart rate similar to those observed with the use of the two non-selective blockrs, it was shown in a double-blind crossover comparison with propranolol that the haemodynamic changes provoked by the mental arithmetic were not less in the presence of beta1-receptor blockade than when both beta1- and beta2-receptors were blocked. 6 These findings suggest that, during beta2-adrenoceptor blockade, the haemodynamic effects of minor mental stress are not exaggerated because of uncompensated alpha-receptor mediated vasoconstriction, such as occurs following adrenaline infusion.     

The immune response of mice to bacterial antigens given by mouth.

The secretory and systemic antibody responses to oral dead Escherichia coli were examined in A strain mice. The best responses were obtained in mice dosed with 1 x 10(10) bacteria. Orally immunized animals showed an enhanced response to subsequent parenteral immunization with somatic antigens. This effect could be passively transferred with serum. In contrast, the response to the capsular antigen K88 was reduced in the same animals.     

Drug reactions reported in a survey of South Carolina

A survey of the membership of the South Carolina Ophthalmological Society revealed an average of 3 1/2 patient drug reactions per year per physician using topical diagnostic drugs in the office. The reactions to the drugs included topical allergic responses, acute glaucoma, cardiovascular collapse, and one death. All of the reactions had previous been attributed to these drugs in the literature. Suggestions are presented to prevent these reactions from occurring or to better prepare the ophthalmologist and his staff to manage these problems when they do arise.