Feline ocular toxoplasmosis

Ocular infection with Toxoplasma gondii is a well-recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive for T. gondii , are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed.     

Artificially regenerating longleaf pine in canopy gaps: initial survival and growth during a year of drought

Nitrogen fertilization in the nursery, along with altering the configuration of forest gaps, may improve the reforestation success of longleaf pine seedlings. During the very droughty 1998 growing season in Florida and Georgia, survival was higher under the forest canopy than in small (0.10 ha, 36 m diameter) and large (1.6 ha, 144 m diameter) canopy gaps. In the large gaps, survival of containerized seedlings was higher along the edges, particularly the SW edge. Shade from adult trees and the nurse effect of shrubs increased survival, while grass competition reduced survival. During dry years part of the “exclusionary zone” along the edge of canopy gaps (SW sector) may serve as a “survival zone”, at least in the short term. A model using oval-shaped gaps oriented from NW to SE, with an area of 0.25 ha is proposed to maximize the survival and growth of artificially regenerated longleaf pine seedlings.     

Factors influencing stump sprouting by pondcypress (Taxodium distichum var. nutans (Ait.) Sweet)

Sprouting can be an important mechanism of regeneration in harvested cypress (Taxodium sp.) wetlands; however, limited information exists on factors influencing sprouting. We examined the influence of harvesting practices, tree size, and site conditions on stump sprouting in eight pondcypress (Taxodium distichum var. nutans (Ait.) Sweet) wetlands in Florida, USA. Stumps were cut at three heights: 20 cm below high water level, at high water, and 40 cm above high water. Half of each site was harvested using a sawhead feller and the other half using shearhead. We monitored sprouting for 2 years post-harvest. Stump height affected first year sprouting, but the effect disappeared during year 2. Felling equipment did not affect sprouting; however, the shearhead caused greater stump damage. Sprouting declined with increasing parent tree size; percentage of stumps with sprouts after 2 years was 68% for trees 10–14 cm dbh and 28% for trees 20–24 cm dbh. Stump sprouting ranged among sites from 23 to 54% after 2 years. Results indicate that sprouting may be an important, but inadequate, form of regeneration. At sites with short hydroperiods, dense understories, and/or predominance of trees greater than 20 cm dbh, reduced sprouting may occur, and planting seedlings may be beneficial.     

Azeotrope of Isopropyl Alcohol and Isopropyl Borate

An azeotrope which boils at 82.0 degrees C (corrected) is formed from i-propyl alcohol and i-propyl borate. The azeotrope contains at least 5.4 percent by weight of ester.     

THE EPIDEMIOLOGY OF EQUINE STRONGYLOSIS IN SOUTHERN QUEENSLAND 3. Seasonal Variation in Arterial Populations of Strongylus vulgaris, and the Prevalence of some Helminths

SUMMARY The anterior mesenteric arteries of 138 horses slaughtered in southern Queensland were examined for the presence of S. vulgaris larvae. Seasonal differences were noted in the size of arterial populations of this parasite, with higher mean monthly numbers of worms per horse occurring in winter. There was an equally high incidence of severe verminous arteritis during the winter months of June, July and August, compared to arteries examined during the warmer months, when there were smaller numbers of larvae. It was concluded that more infective larvae were available on pasture during the warmer months, with subsequently large arterial populations some 3 to 4 months later. The parasite was encountered in 121 arteries (88%). The prevalence of adult helminths in the caeca of the same group of horses was S. vulgaris 88%; S. equinus 70%; S. edentatus 18%; Triodontophorus spp. 23%; A. perfoliata 62%. The overall prevalence of S. vulgaris was 93%, when the results of arterial and caecal observations were combined.     

Pharmacokinetic evaluation of a slow-release cefotaxime suspension in the dog and in sheep

Three Merino ewes were given cefotaxime IM, and 3 were given cefotaxime subcutaneously (50 mg/kg of body weight each); each dose was suspended in 6 ml of oil. Five dogs were also given an oily suspension of cefotaxime subcutaneously (SC) (50 mg/kg of body weight). The plasma concentrations (Cp) and pharmacokinetic data obtained after cefotaxime in the oily suspension was injected IM and SC were compared with data from the same animals after they were given an aqueous solution of cefotaxime by the same routes. Key pharmacokinetic values obtained after cefotaxime was administered IV to sheep and to dogs are discussed. Mean peak Cp (Cpeak) in sheep when given the oily suspension IM was approximately 53 micrograms/ml at 0.18 to 0.40 hour, and that value in sheep given the aqueous preparation was 62 micrograms/ml 0.08 to 0.18 hour. Mean Cpeak values after the oily suspension and the aqueous preparation were injected SC were 11.0 micrograms/ml (between 0.8 and 1 hour) and 51 micrograms/ml (between 0.25 and 1 hour), respectively. Bioavailabilities were approximately 70% after IM injection was done and 90% after SC injection was done. The beta-plasma half-lives were 0.7 hour after IM injection was done and 2.9 hours after SC injection was done. Mean Cpeak in dogs when given the oily suspension SC was 30 micrograms/ml at 1.0 hour, and when dogs were given the aqueous preparation SC, Cpeak was 27 micrograms/ml at 0.6 hour. Absorption was virtually complete after the oily suspension and aqueous preparations were given.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacokinetics of cefotaxime in sheep

Five healthy adult Merino ewes were each given 2 g of cefotaxime by the IV, IM, and subcutaneous (SC) routes. The serial plasma samples collected after each treatment were analyzed for cefotaxime by a new high-pressure liquid chromatographic method. Plasma concentration time profiles were characterized by a linear 2-compartment model after IV administration and the following mean values (+/- SD) were found: biological half-life, 23 +/- 8 minutes; apparent volume of distribution, 5.5 +/- 1.3 L; plasma clearance, 0.37 +/- 0.09 L/min; elimination rate constant, 0.066 +/- 0.014 minute-1; rate of diffusion into tissue, 0.013 +/- 0.013 minute-1; and out of tissue, 0.035 +/- 0.017 minute-1. Plasma cefotaxime concentrations in the ewes given the drug by the IV, IM, and SC routes were 113 +/- 32, 71 +/- 20, and 38 +/- 11 micrograms/ml, respectively, at 15 minutes; 2.31 +/- 0.82, 11.3 +/- 6.6, and 16.4 +/- 3.7 micrograms/ml at 120 minutes; and 1.05 +/- 1.22, 9.3 +/- 5.2, and 14.9 +/- 1.27 micrograms/ml at 150 minutes. After cefotaxime was given SC and IM, plasma values were higher for a longer time than they were after the drug was given IV, probably due to a slower release of drug from the former injection sites.