Search PubMed⌕ Search

Biomedical subjects

O Naesh

Publications and source records attributed to O Naesh.

25 records · Page 2Linked to original sources

Post-exercise platelet activation--aggregation and release in relation to dynamic exercise.

Relatively scarce information is found on the period immediately following physical stress, with special reference to human platelet activity. This, in connection with earlier observations of an increase in platelet release products and hyperaggregability following surgical stress, has initiated the present study. We studied platelet function in eight healthy non-mediated volunteers during and 1 h after cycle exercise of submaximal intensity. ADP-induced platelet aggregability was enhanced in the last minute of exercise followed by a decreased aggregability 1 h after. Adrenaline-induced platelet aggregation showed the same attenuation after exercise but no change during work. The release products beta-thromboglobulin and serotonin in plasma showed significant increases after exercise. This is taken as evidence of an enhanced platelet activity following exercise. A normal stress-response, measured as increase in cyclic AMP in plasma, was observed. In conclusion, platelets are activated following moderate exercise and it seems valid to include the post-exercise period in future studies.

Adenosine Diphosphate↗

Metoclopramide (Primperan) in the treatment of ureterolithiasis. A prospective double-blind study of metoclopramide compared with morphatropin on ureteral colic.

A prospective double-blind study was performed to compare metoclopramide (Primperan) with morphatropin in the treatment of ureteral colic. Twenty-one patients (10 in the morphatropin group and 11 in the metoclopramide group) entered the study and diagnosis was confirmed radiologically. Using the Mann-Whitney rank sum test, no significant difference was found in the pain-relieving effect 10, 20, or 30 min after treatment with either 1 ml morphatropin s.c. or 20 mg metoclopramide i.v. Two patients in the morphatropin group developed nausea and giddiness, respectively, and 1 patient from this group was omitted due to the development of urticaria. No side effects occurred in the metoclopramide group. Thus metoclopramide seems to be an alternative to the traditional treatment of ureteral colic with morphia.

Acute Disease↗

Platelet alpha-adrenoceptor function and aging.

The effect of aging on platelet alpha-adrenoceptor binding of 3H-dihydro-alpha-ergocryptine (3H-DHE) and alpha-adrenoceptor response expressed as cAMP decrease, after the addition of noradrenaline 10 microM to intact platelets in vitro were examined and correlated with adrenaline induced platelet aggregation in a group of twelve young volunteers (mean age 21 years), and twelve old volunteers (mean age 88 years). The binding by platelets of 3H-DHE was considerably higher in the young than in the old group (mean 292.70 +/- 40.79 and 167.90 +/- 18.30 fmol/mg protein respectively, p less than 0.02). The affinity (Kd) was also influenced with values of 1.49 +/- 0.21 in the young and 3.32 +/- 0.45 nM in the old, p less than 0.01). Stimulation of platelets with noradrenaline caused a greater decrement of cAMP in the old than in the young group (mean 4.44 +/- 0.87 as compared with 0.32 +/- 0.75 pmol/10(9) platelets. Platelet sensitivity to adrenaline, when expressed as aggregation increased in the old group. These data suggest that the enhanced sensitivity to adrenaline as observed in old people is not the result of increased alpha-adrenoreceptor number of affinity, but related to changes in the platelet membrane possibly not related to the alpha-adrenoceptors.

Adolescent↗

Aging and platelet beta-adrenoceptor function.

Ten young volunteers (mean age 20 years) and ten elderly volunteers (mean age 89 years), including equal numbers of healthy men and women, were tested regarding adrenaline-induced platelet aggregation in vitro, platelet cyclic AMP content before and after beta-adrenoceptor stimulation with isoprenaline, as well as binding by platelet membranes of 125I-hydroxybenzylpindolol. In the aged patients there was a highly significant decrease in the concentration of adrenaline needed to produce irreversible platelet aggregation, as compared with the young. Platelet basal cyclic AMP content did not differ but the response to isoprenaline stimulation, expressed as the percentage rise of cyclic AMP content above the unstimulated level, was significantly decreased in the old subjects. The beta-adrenoceptor number was unchanged but the affinity decreased significantly in the old group. The data suggest that the increased aggregation response to adrenaline in old people could be due in part to a diminished functional capacity of the platelet beta-adrenoceptor.

Adult↗

Platelet function in surgical stress.

Ten patients for elective cholecystectomy were studied pre-, per-and postoperatively. All had neurolept anesthesia. Plasma concentrations of beta-TG, TXB2 and 5-HT and intraplatelet 5-HT were measured. Aggregation to ADP was recorded. Serum cortisol concentration was used as index of the stress response, showing peroperative increase and postoperative decrease. Closely related to this we observed a significant increase in P--beta-TG and P-TXB2 with postoperative normalization in 6 patients without complications. P--5-HT had a peak peroperatively and remained elevated postoperatively. A negative correlation between P--5-HT and decreasing intraplatelet 5-HT postoperatively was observed. High postoperative levels of P--5-HT seem to be related to low arterial PO2 and pulmonary dysfunction. In 3 patients with complications a second increase in P--beta-TG, P-TXB2 and partly in P--5-HT was found. Platelets were temporarily refractory to ADP immediately following surgery and showed increased aggregability postoperatively. We conclude that platelets are activated in surgical stress.

Adenosine Diphosphate↗

Subarachnoid bupivacaine increases human cerebrospinal fluid concentration of serotonin.

BACKGROUND AND OBJECTIVES: Serotonin (5-hydroxytryptamine [5-HT]) has antinociceptive properties at the spinal level. Activation of descending serotonergic neurons or topically applied 5-HT at the spinal cord inhibits rostral spread of sensory information. Epidural anesthesia has been shown to increase 5-HT in plasma, and local anesthetics may interfere with 5-HT reuptake and metabolism. For these reasons, the action of subarachnoid local anesthetics on cerebrospinal fluid (CSF) 5-HT concentrations has been studied. METHODS: Six volunteers received lumbar spinal anesthesia with 0.5% bupivacaine through subarachnoid catheters, and CSF and plasma 5-HT concentrations were determined radioenzymatically before and after anesthesia. RESULTS: Plasma 5-HT was unchanged, but CSF 5-HT increased by 300% after bupivacaine administration (P < .02). CONCLUSION: Subarachnoid bupivacaine increases local 5-HT concentration. This may have implications for nociceptive gating as well as for local vasoregulation.

Adult↗