The polyunsaturated wax esters which occur in an oil droplet in Calanus helgolandicus apparently serve as a short term reserve metabolic fuel. The lipids of the copepods were labeled by feeding them (14)C-labeled diatoms, Skeletonema costatum, after which starvation and turnover experiments were carried out. During starvation both wax esters and triglycerides are largely depleted within 72 hr, whereas cholesterol and phospholipid decreased at much slower rates.

Animals↗

PubMed1967

Cofactor requirements of thymine 7-hydroxylase.

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Coenzymes↗

PubMedDate not supplied

Effect of topical fluoroquinolones on corneal re-epithelialization after excimer laser keratectomy.

PURPOSE: To measure the effects of commercially prepared topical fluoroquinolones on the healing rate of epithelial defects in the rabbit cornea after excimer laser keratectomy. SETTING: The Doheny Eye Institute and the Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles, California, USA. METHODS: Twenty-four New Zealand white rabbits had unilateral excimer laser superficial keratectomy to create a circular, central corneal epithelial defect. Following keratectomy, each rabbit was randomly assigned to one of three treatment groups, each consisting of eight rabbits. Each rabbit was treated with one drop of the assigned medication, each hour until epithelialization was complete; Group 1 received ciprofloxacin, Group 2, ofloxacin, and Group 3, preservative-free artificial tears as a control. The epithelial defect was stained with fluorescein and photographed every 12 hours with a cobalt blue filtered light. Planimetric measurements of the wound area were made with an image analysis system. RESULTS: The control group eyes were re-epithelialized within 84 hours. The fluoroquinolone-treated eyes required 144 hours for complete healing. Both ciprofLoxacin and ofloxacin significantly delayed corneal epithelial healing (P = .0055) compared with the control. Two animals treated with topical ciprofloxacin developed a white precipitate in the area of the epithelial defect; however, the precipitate did not prevent closure of the epithelial defect. No such precipitate was seen with ofloxacin. CONCLUSION: These data suggest that both ofloxacin and ciprofloxacin influence corneal wound healing in rabbits after laser keratectomy and that their healing rates did not differ. A white precipitate that appeared in the epithelial defect area in some rabbits treated with ciprofloxacin did not prevent closure of the defect.

Administration, Topical↗

PubMedDate not supplied

Induction of monooxygenase activity in the intestine of spot (Leiostomus xanthurus), a marine teleost, by dietary polycyclic aromatic hydrocarbons.

The response of intestinal monooxygenases to dietary polycyclic aromatic hydrocarbon (PAH) exposure was evaluated in spot (Leiostomus xanthurus), a marine teleost fish. Ethoxyresorufin O-deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH) activities were highest in the pyloric caeca and in the proximal half of the intestine. Intestinal microsomes from fish given control diets had very low levels of EROD and AHH activities relative to those in liver. After exposure to a diet containing 10 mg of 3-methylcholanthrene/kg of food, the levels of intestinal EROD and AHH activities increased 36-fold and 17-fold, respectively, such that intestinal monooxygenase activity exceeded that of the liver, which was not induced by this treatment. A significant increase in intestinal monooxygenase activity occurred in fish receiving dietary benzo[a]pyrene (BP) at concentrations as low as 10 micrograms of BP/kg food. A 5-fold increase in intestinal AHH and EROD activities was observed within 3 hr after administration of dietary BP. A plateau in gut monooxygenase activity occurred after approximately 3 days of PAH exposure; these activities decreased to control levels within 3 days after replacing the PAH diet with the control diet. Starvation resulted in disappearance of detectable monooxygenase activity. Monoclonal antibody (MAB 1-12-3) against the major PAH-inducible cytochrome P-450 (P-450E) in the liver of the marine teleost (Stenotomus chrysops) [Park et al. Arch. Biochem. Biophys. 249, 399 (1986)] recognized a single protein band in intestinal microsomes, with Mr near 54,000, which we conclude is the spot counterpart to cytochrome P-450E.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗