Prevention of emesis after strabismus repair in children: a prospective, double-blinded, randomized comparison of droperidol versus ondansetron.

STUDY OBJECTIVE: To compare the effectiveness of ondansetron with droperidol in preventing postoperative emesis in children after strabismus repair. DESIGN: Randomized, double-blind study. PATIENTS AND SETTING: 57 ASA physical status I and II children aged 3 to 14 years, undergoing outpatient strabismus repair in two separate study centers. INTERVENTIONS: Patients were randomized to receive either 0.15 mg/kg intravenous (i.v.) ondansetron or 0.075 mg/kg i.v. droperidol shortly after induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Number of episodes of emesis and times to discharge from the recovery room and ambulatory center were assessed. Twenty-nine (94%) of 31 children who received ondansetron and 21 (81%) of 26 children who received droperidol were emesis-free (p = NS). There were no significant differences in the number of episodes of emesis on the day after surgery or times to discharge. CONCLUSIONS: Ondansetron is at least as effective as droperidol in reducing the frequency of emesis in children after strabismus repair, and it did not shorten times to discharge home. The low number of patients in our study may have masked a difference in effect between the two groups. The clinician should decide whether the increased cost of ondansetron justifies its use over other antiemetics.

Measurement of thermally produced volatile alkanes: an assay for plant hydroperoxy fatty acid evaluation.

A new method designed to monitor lipid peroxidation in plants has been set up with soybean hypocotyl/radicles. The hydroperoxy fatty acids present in situ are converted by rapid thermal treatment (80 s and 210 J g-1) of the biological sample into ethane and n-pentane, which are analyzed by gas chromatography. The method has been directly calibrated by quantification of the hydroperoxy fatty acids by silica-phase HPLC analysis of their reduced hydroxy derivatives. Hypocotyl/radicles from the two soybean cultivars Argenta and Soriano were submitted to various chemical oxidative treatments and were analyzed for both thermally produced volatile alkanes and hydroperoxy fatty acid levels. Our results showed that ethane and n-pentane production are in both cases closely correlated with linolenic as well as linoleic acid hydroperoxide levels (P < 0.001). Within a given plant material, thermal conversion of both hydroperoxides into alkanes occurred with yields which were not dependent on the oxidative treatment. These yields are however functions of the biological material since in Soriano and Argenta cultivars they were around 6 and 25%, respectively. Taking into account the last point, the alkane test cannot be used to directly quantify the absolute lipid hydroperoxide levels of plant tissues but it is convenient to monitor the peroxidative phenomenon as it occurs. The assay is easy and rapid to perform (analysis of 50 samples per day) since no sample preparation is needed, and the low detection limit (20 pmol of alkane g-1) permits the analysis of small samples.

Modification of Phospholipid Catabolism in Microsomal Membranes of [gamma]-Irradiated Cauliflower (Brassica oleracea L.).

Acceleration of membrane deterioration has been observed recently during storage of [gamma]-irradiated cauliflower (Brassica oleracea L., Botrytis group). In the present study, the activity of microsome-associated lipolytic enzymes was investigated in cauliflower florets exposed to 0 or 4 kilograys of [gamma] radiation and stored for 8 d at 13[deg]C. Radiolabeled breakdown products obtained from the metabolism of (16:0/18:2*)-phosphatidylcholine and (16:0/16:0)-phosphatidyl-[N-methyl-3H]choline by microsomal membranes indicated that phospholipase D (EC 3.1.4.4), phosphatidic acid phosphatase (EC 3.1.3.4), and lipolytic acyl hydrolase were associated with the membranes. The rate of phosphatidylcholine catabolism by the membranes increased slowly in control cauliflower during storage. [gamma] irradiation caused an immediate rise in phosphatidylcholine catabolism that remained higher than that of the controls during subsequent storage. Collectively, the data suggest that enhancement of membrane lipolytic activity results from free-radical-induced stress. Rapid increase of the membrane-associated phospholipase D activity may be a key event leading to accelerated membrane deterioration following [gamma] irradiation.

Induction of Senescence-Like Deterioration of Microsomal Membranes from Cauliflower by Free Radicals Generated during Gamma Irradiation.

Membrane deterioration differs in aging and senescent tissues. Involvement of free radicals in the process is generally recognized. Little is known about the physiological effects of gamma irradiation on plant tissues. Degradation of microsomal membranes by the action of free radicals, generated in vivo by gamma rays, was investigated. Cauliflower florets (Brassica oleracea L., Botrytis group) were exposed to 2 or 4 kiloGray of gamma radiation. Membrane deterioration was assessed during 8-day storage at 13 degrees C. Some senescence was indicated in nonirradiated controls by a parallel depletion of lipid phosphate and protein. Irradiation caused an immediate increase in tissue electrolyte leakage and a small increase in the free fatty acid content of membranes. In irradiated samples, leakage of electrolytes and the ratios of sterol to phospholipid and of free fatty acid to phospholipid increased with storage. During this period, membrane protein was progressively lost and the lipid phosphate-to-protein ratio increased markedly. Polyunsaturated fatty acids were selectively depleted from the free fatty acid fraction for all treatments, suggesting lipoxygenase activity. No change in lipid saturation was observed in the polar lipid fraction. The results suggest an enzyme-catalyzed senescence-like membrane deterioration, probably induced by chemical deesterification of phospholipids by free radicals generated during irradiation.