Leptospirosis and panuveitis in a dog

A case of panuveitis as a result of leptospiral infection in an 8-year-old Jack Russell Terrier is reported. Mild hyphema, aqueous flare, and partial serous retinal detachments were noted in both eyes on initial ophthalmic examination. The serum microscopic agglutination testing for Leptospira serovarieties revealed titers of 1 : 12 800 for Leptospira canicola and 1 : 200 for Leptospira icterohemorrhagiae. With medical therapy, the panuveitis resolved and functional vision was regained. Four weeks after the initial presentation, convalescent titers were 1 : 200 for L. canicola and 1 : 100 for L. icterohemorrhagiae. The incidence of leptospirosis, along with difficulties diagnosing, and current medical therapies for this disease are also discussed.     

An examination of the prevalence of and risk factors for shedding of Cryptosporidium spp. and Giardia spp. in cows and calves from western Canadian cow-calf herds

The primary objectives of this study were to describe the prevalence and risk factors for Cryptosporidium spp. and Giardia spp. infection in cows and calves during the calving season in western Canadian cow-calf herds. Through the calving season of 2002, fresh fecal samples were collected from 560 beef cows and 605 calves in western Canada. Feces were examined for the presence of Cryptosporidium spp. and Giardia spp. using a quantitative sucrose gradient immunoflourescent antibody test. Samples were collected from mature cows on 59 farms and from calves on 100 farms. Only 1.1% (5/560) of the cows were positive for Cryptosporidium spp. whereas 3.1% (19/605) of the calves were positive. Prevalence for Giardia spp. was much higher; Giardia spp. was detected in 17.0% (95/560) of the cow and 22.6% (137/605) of calf fecal samples. Data describing herd management practices, treatment and disease history, age, gender, breed and fecal consistency were gathered to assess potential risk factors associated with shedding. The association between the risk of shedding and average precipitation from December to June and ecological region were also evaluated. Risk factors for infection with Cryptosporidium spp. in either cows or calves could not be evaluated because the multilevel model would not converge due to the relatively low prevalence of the organism in this sample. The prevalence for Giardia spp. was sufficient to explore potential risk factors in both cows and calves. No risk factors were identified for Giardia spp. in beef cows following calving. After the construction of a multivariable model, the only significant predictors for Giardia spp. presence in beef calves was dam age and calf age. Calves born to 2-year-old heifers were 2.3 (95% CI, 1.09-5.06; P = 0.031) times more likely to be shedding Giardia spp. then calves born to cows that were 4-10 years of age. Calves that were 9-18 days of age and calves that were > 18 days of age were 22.4 (95% CI, 5.88-88.18; P < 0.001) and 150 (95% CI, 39.72-603.19; P < 0.001) times more likely, respectively, to be shedding Giardia spp. than calves < or = 4 days of age.     

Dietary exposure of Canadians to perfluorinated carboxylates and perfluorooctane sulfonate via consumption of meat, fish, fast foods, and food items prepared in their packaging

Human exposure to perfluorinated compounds is a worldwide phenomenon; however, routes of human exposure to these compounds have not been well-characterized. Fifty-four solid food composite samples collected as part of the Canadian Total Diet Study (TDS) were analyzed for perfluorocarboxylates and perfluorooctanesulfonate (PFOS) using a methanol extraction liquid chromatography tandem mass spectrometry method. Foods analyzed included fish and seafood, meat, poultry, frozen entrées, fast food, and microwave popcorn collected from 1992 to 2004 and prepared as for consumption. Nine composites contained detectable levels of perfluorinated compounds-four meat-containing, three fish and shellfish, one fast food, and one microwave popcorn. PFOS and perfluorooctanoate (PFOA) were detected the most frequently; concentrations ranged from 0.5 to 4.5 ng/g. The average dietary intake of total perfluorocarboxylates and PFOS for Canadians was estimated to be 250 ng/day, using results from the 2004 TDS composites. A comparison with intakes of perfluorocarboxylates and PFOS via other routes (air, water, dust, treated carpeting, and apparel) suggested that diet is an important source of these compounds. There was a substantial margin of exposure between the toxicological points of reference and the magnitude of dietary intake of perfluorinated compounds for Canadians >/= 12 years old.     

Effects of age on the electroencephalographic response to castration in lambs anaesthetized with halothane in oxygen from birth to 6 weeks old

ObjectivesTo characterize changes in the cerebro‐cortical response of lambs to rubber‐ring castration during the first 6 weeks of postnatal life.AnimalsCoopworth‐Texel cross ram lambs between 3 hours and 44 days of age.MethodsThe electroencephalogram (EEG) and heart rate responses to rubber ring castration were compared. Anaesthesia was induced via a face mask and maintained with halothane in oxygen (e′_Hal = 1.2%). Once a stable plane of anaesthesia had been achieved, data collection of EEG and electrocardiogram (ECG) commenced, and the lambs were castrated 15 minutes later, using rubber rings. Heart rate was derived from the ECG and the median frequency (F₅₀), spectral edge frequency (F₉₅) and total power (p_tot) were derived from the EEG.ResultsCastration‐induced changes in F₅₀ increased from 2 ± 1.8% in the youngest lambs to a maximum of 33 ± 8.9% in the 36 ± 0.5 day‐old lambs. Changes in F₉₅ increased from ?7 ± 3% in the youngest lambs to a maximum of 16 ± 11% in the 36 ± 0.5 day‐old lambs. Linear regression analysis in lambs up to 10 days of age demonstrated a change in the response with age that was significantly different from zero for F₅₀ (r² = 0.28, p = 0.007) and F₉₅ (r² = 0.38, p = 0.001), but not for p_tot or heart rate.ConclusionThis study identified significant changes in the responsiveness of the lambs’ cerebral cortex to the noxious stimulation of castration over the first 7–10 days of postnatal life. The results suggest that mechanisms that suppress responses of the fetus to noxious stimulation may still be active in the first few days after birth.Clinical relevanceThis study documents changes in central nociceptive processing which may reflect the ability of neonatal animals to perceive pain.     

Stability of the flavan-3-ols epicatechin and catechin and related dimeric procyanidins derived from cocoa

Cocoa flavanols and procyanidins possess wide-ranging biological activities. The present study investigated the stability of the cocoa monomers, (-)-epicatechin and (+)-catechin, and the dimers, epicatechin-(4beta-8)-epicatechin (Dimer B2) and epicatechin-(4beta- 6)-epicatechin (Dimer B5), in simulated gastric and intestinal juice and at different pH values. The dimers were less stable than the monomers at both acidic and alkaline pH. Incubation of Dimer B2 and Dimer B5 in simulated gastric juice (pH 1.8) or acidic pH resulted in degradation to epicatechin and isomerization to Dimer B5 and Dimer B2, respectively. When incubated in simulated intestinal juice or at alkaline pH, all four compounds degraded almost completely within several hours. These results suggest that the amount, and type, of flavanols and procyanidins in the gastrointestinal tract following the consumption of cocoa can be influenced by the stability of these compounds in both acidic and alkaline environments.     

Effects of selection for reduced oviposition interval on plasma concentrations of luteinising hormone during the ovulatory cycle in hens on a 24 h lighting cycle

The effects of selection under continuous light for reduced oviposition interval within a sequence of eggs on plasma luteinising hormone (LH) concentrations during the ovulatory cycle were investigated in lines of Australorps and White Leghorns maintained on a 24-h light:dark cycle. Selection did not significantly alter LH concentrations during mid-sequence cycles in either breed. In the control lines, concentrations were higher in the Australorps than in the White Leghorns before and at peak in mid-sequence cycles. The increase in egg production resulting from selection was associated with an advance in the mean time of lay of mid-sequence eggs in both breeds and, in the Australorps, with more pre-ovulatory LH peaks being initiated at the beginning of the open period of the ovulatory cycle. Selection reduced the time an egg spends in the oviduct and, in the Australorps, significantly reduced the interval between a pre-ovulatory LH peak and the oviposition of the egg currently in the shell gland. We suggest that selection under continuous light for reduced oviposition interval increased the rate of ovarian follicular maturation by a mechanism which did not involve an increase in pre-ovulatory concentration of plasma LH in a 24-h light-dark cycle.     

Candida's arranged marriage

Biologists who study the fungus Candida albicans have always assumed that this organism reproduces asexually because they have not found evidence of mating, meiosis, or a haploid stage of the life cycle. However, as Gow et al. explain in a Perspective, sequencing of the C. albicans genome has revealed the existence of a possible mating type locus. This finding has now been extended to demonstrate actual mating in the fungus (Hull et al., Magee and Magee).     

Physical properties of sea ice discharged from fram strait

It is estimated that 84 percent of the ice exiting the Arctic Basin through Fram Strait during June and July 1984 was multiyear ice and that a large percentage of this ice is ridged or otherwise deformed. While freeboard and thickness data, together with salinity measurements on cores, usually sufficed to distinguish between first and multiyear floes, preliminary identification could usually be made on the basis of snow cover measurements with snow cover being much thicker on multiyear ice. Cores from the top half meter of multiyear floes were generally very much harder and more transparent than cores from first-year floes. Age estimates of multiyear floes, based on petrographic and salinity characteristics of cores, did not exceed 4 to 5 years for any of the floes that were observed exiting Fram Strait.