Norepinephrine release in the human forearm: effects of epinephrine

It has been postulated that delayed facilitation of norepinephrine release by epinephrine is causally related to the development of hypertension. It has been proposed that a brief increase in epinephrine concentrations results in the uptake of epinephrine into the sympathetic nerve terminal. Subsequent rerelease of epinephrine stimulates presynaptic beta-adrenergic receptors, resulting in a prolonged increase in plasma norepinephrine (NE) concentrations, with amplified sympathetic responses and vasoconstriction. To determine whether such epinephrine-induced, delayed facilitation of NE release occurs in a vascular bed draining resistance vessels and, if it occurs, whether that facilitation differs in hypertension, we used a radioisotope dilution method to measure unstimulated and isoproterenol-stimulated forearm NE spillover before, during, and after a 50 ng/min infusion of epinephrine for 30 minutes directly into the brachial artery. No delayed facilitatory effects of epinephrine on forearm NE spillover were observed in either 6 normotensive (NT) or 8 borderline hypertensive (BHT) subjects (NT unstimulated forearm NE spillover preepinephrine 1.79+/-0.41 ng/min versus postepinephrine 2.36+/-0.65 ng/min, P=.38; BHT preepinephrine 2.24+/-0.70 ng/min versus postepinephrine 1.93+/-0.46 ng/min, P=.51; NT isoproterenol-stimulated forearm NE spillover preepinephrine 4.61+/-1.01 ng/min versus postepinephrine 4.4+/-0.98 ng/min, P=.9; BHT preepinephrine 4.04+/-1.36 ng/min versus postepinephrine 4.69+/-1.49 ng/min P=.5). We conclude that the short-term local infusion of epinephrine does not have a delayed facilitatory effect on forearm NE spillover in NT or BHT subjects. Therefore, the prolonged increase in NE concentrations after epinephrine infusion previously shown systemically, and not seen locally in the forearm, suggests that the delayed facilitatory response to epinephrine may occur in other organs.     

Computerized medication instruction for psychiatric inpatients admitted for acute care

We studied the efficacy and feasibility of using computer-based instruction to provide medication information to hospitalized patients with acute psychotic conditions. Patients were randomly assigned to receive computer-based (n = 21) or personal instruction (n = 21); for the final analyses the computer group was expanded to include 13 patients from a pilot study. Outcome measures were knowledge retention (indicated by changes in test scores) and compliance with medication regimens after discharge (indicated by telephone follow-up at one week, one month, and three months). The subjects reacted positively to the computer program. Knowledge retention and compliance were similar in the computer and control groups. We conclude that psychiatric inpatients admitted for acute care can participate in, and learn from, computerized medication instruction.     

Electrospray ionization and collision-induced dissociation of antibiotic polyether ionophores

The hypothesis of the present study was that previous experience of caries may serve as an indicator for individualised bitewing examinations in 15-19-old adolescents. One hundred adolescents, all 19 years old, were randomly selected from the files of public dental clinics in the County of Orebro. For 93 adolescents the total number of radiographs were summed for every patient from the age of 3 to 19 by assessing the files of public dental clinics and by assessing the files of the dental radiology department. All sets of bitewing radiographs from 14 up to and including the age of 19 were assessed with respect to approximal caries. The average number of intraoral radiographs exposed in a patient from the age of 3 through 19 was 24.4. It was shown that 70 to 80% of 14-19-year-old-adolescents had had a bitewing examination every year. The decision to perform a bite-wing examination in a 15-year-old was significantly correlated to the number of surfaces with initial caries at the age of 14. In the other age groups, none of the investigated variables was found to be significantly correlated to the performance of radiographic examinations.