Cyclic AMP and cyclic GMP concentrations in, and efflux from, preimplantation cattle embryos.

Basal embryonic cAMP and cGMP concentrations and cAMP and cGMP accumulation in embryos and in the incubation medium were measured in cattle blastocysts recovered at days 14 (n = 23), 15 (n = 29) and 16 (n = 23) of pregnancy. Cyclic AMP and cGMP concentrations were measured by radioimmunoassay and the results expressed per microgram of protein, which was determined by the Pierce Micro BCA protein assay. Cyclic AMP and cGMP were present on each day. Basal embryonic cAMP was similar on days 14, 15, and 16, at 2.3., 2.5 and 2.6 fmol per microgram protein, respectively, while the concentration of cGMP was higher at day 14 (0.14 fmol per microgram protein than at either day 15 or 16 (0.06 and 0.05 fmol per microgram protein, respectively; P < 0.05), which were similar (P > 0.10). Basal embryonic cAMP concentrations were 15 to 60-fold higher than cGMP concentrations. Following a 2 h culture period in the presence or absence of the phosphodiesterase (PDE) inhibitor, isobutylmethylxanthine (IBMX), the accumulated concentrations of cAMP and cGMP were measured in the embryos and in the incubation medium. IBMX did not affect the concentrations of either cAMP or cGMP in the embryos but increased the concentrations of cAMP (P < 0.005) and cGMP (P < 0.01) in the incubation medium. There was no effect of day on either embryonic or medium cAMP, but both embryonic and medium cGMP were higher at day 14 than at day 15 (P < 0.05) or 16 (P < 0.005). Differences between embryonic and medium cAMP and cGMP accumulation were examined. There was no effect of day or treatment. cGMP accumulation in the medium was higher than in the embryos (P < 0.005) whereas cAMP accumulation in the medium was lower than in the embryos (P < 0.05). Whether the efflux of cAMP and cGMP is active or passive is not clear but it may indicate a possible role in embryo-maternal signalling.

Effects of work task cues and play task cues on information processing, judgment, and motivation.

How task cues affect cognition, attitudes, and behavior was explored in this laboratory study with 82 master of business administration students. Linguistic analysis of responses to the same puzzle task, cued as either work or play, revealed that task cues influenced how information was perceived and was used to form judgments and to shape behavioral responses. Ss performing work tasks attended more to information about the quantity of their performance and made more streamlined, goal-directed responses. Ss performing play tasks attended more to information about the quality of their performance; made more elaborated, image-laden responses; and were more intrinsically motivated. Links among task cues, cognitive processes, and performance were explicated through path analysis. Task cues affected performance outcomes indirectly by instantiating associated cognitive orientations: a means orientation in play and an ends orientation in work.

Aggressive behavior as a function of Taekwondo ranking.

This study examined the effect taekwondo training has on the level of aggression of children between the ages of 6 and 11 yr. 68 students (boys and girls) were tested using a behavior checklist designed to measure children's aggression. Analysis indicated a significant inverse relationship between the children's taekwondo rank and their aggression.

Construct validity of the Children's Embedded Figures Test.

The Children's Embedded Figures Test and the Matching Familiar Figures Test were given to 28 children ranging in age from 5 to 12 yr. (M age = 9.3 yr.) to estimate the construct validity of the Children's Embedded Figures Test. A significant correlation of .65 between age and number of correct embedded figures and a nonsignificant correlation of .32 between number of correct embedded figures and latencies to match familiar figures were found. Implications are examined in the light of earlier findings demonstrating the convergent validity of the Children's Embedded Figures Test.

Efficacy and safety of timolol for prevention of supraventricular tachyarrhythmias after coronary artery bypass surgery.

Forty-one patients undergoing coronary artery bypass grafting were randomly assigned to receive prophylactic timolol or placebo, given in a double-blind fashion. beta-Adrenoceptor-blocking therapy was stopped at least one half-life before surgery. Three to 7 hr after surgery (304 +/- 56 min), 0.5 mg of timolol or placebo was given intravenously twice daily in a double-blind manner. When oral medications were resumed postoperatively, 10 mg of timolol twice daily or placebo was continued orally. Continuous electrocardiograms were recorded for 24 hr before and for 7 days after surgery with a standard cassette recorder. No patient received digoxin. Both groups were comparable for frequency of preoperative supraventricular arrhythmias, left ventricular ejection fraction, duration of cardiopulmonary bypass, aortic cross-clamp time, number of bypass grafts, and total duration of monitoring. Analysis of arrhythmias was done by hand counts, and supraventricular arrhythmias were divided into supraventricular tachycardia and atrial fibrillation and/or flutter. Timolol decreased the frequency of supraventricular tachycardia (581 episodes placebo vs 84 timolol; p less than .05) and of atrial fibrillation and/or flutter (291 episodes placebo vs five timolol; p less than .05). Timolol decreased the number of patients with severe (heart rate greater than 200 beats/min, duration greater than 50 beats) episodes of supraventricular tachycardia (four placebo vs 0 timolol; p less than .05) and also decreased the number of episodes of severe (heart rate greater than 200 beats/min, duration greater than 5 min) atrial fibrillation and/or flutter (16 placebo vs one timolol; p less than .005). There were differences in the durations of supraventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of intravenous piretanide and furosemide in patients with congestive heart failure.

In order to compare the efficacy of piretanide, a loop diuretic, with furosemide in the setting of congestive heart failure, 20 patients with moderate-to-severe congestive heart failure were studied in a double-blind fashion. Ten patients received piretanide and 10 furosemide intravenously every 12 h for 3 days. Prior to treatment, the groups were indistinguishable in all relevant clinical characteristics. No major adverse reactions were encountered in either patient group. There was no ototoxicity, worsening of cardiac arrhythmias, worsening of diabetes, or systematic perturbation of the serum digoxin concentration. Patients in both groups had similar mild elevation in BUN and serum uric acid levels at the end of the study. There was an equal weight loss for patients in the two groups and an equal excretion of Na, K, and total volume of urine for the two groups. The urinary Na/K ratio was also indistinguishable between the two groups. In both groups, plasma aldosterone concentration tended to increase; there was no alteration in plasma renin activity. We conclude that piretanide and furosemide are equieffective for treatment of congestive heart failure in the doses used. Although in some settings piretanide is potassium sparing, we were not able to demonstrate this property in the population studied.

Low sensitivity of plasma DNA in screening for pulmonary embolism.

Detection of plasma deoxyribonucleic acid (DNA) by counterimmunoelectrophoresis (CIE) has been proposed as a rapid, inexpensive screening test for the diagnosis of pulmonary embolism (PE). To test the sensitivity of plasma DNA detection for the diagnosis of PE, we obtained blood samples from 89 patients when they underwent lung scanning for suspected PE. Plasma was analyzed qualitatively for DNA by CIE, using antiserum that could detect as little as 0.2 micrograms DNA/ml. Among 16 patients with PE diagnosed by high probability lung scan, pulmonary angiography, or at autopsy, plasma DNA was detected in 3 patients--a sensitivity of 19%. Of 6 patients with indeterminate lung scans and a possible diagnosis of PE, 1 had detectable plasma DNA. None of the 67 patients without a diagnosis of PE had detectable plasma DNA, so the specificity was 100%. Thus, although detection of plasma DNA by CIE has many desirable features of a screening test, further studies are needed before this test can be recommended in routine screening for PE.