Pilot evaluation of a vacuum-assisted biopsy instrument for percutaneous renal biopsy in dogs.

Kidney biopsies in dogs are commonly obtained using automated spring-loaded biopsy instruments. Interpretation of biopsies from dogs with glomerular disease requires examination of at least 5-10 glomeruli, with at least two biopsies usually required for full evaluation. The purpose of this study was to compare quality and interpretability of renal biopsies obtained from healthy dogs with a large-gauge, vacuum-assisted biopsy instrument versus two biopsies obtained with a spring-loaded biopsy needle. Twenty dogs were randomized into two groups, and percutaneous, ultrasound-guided renal biopsies were evaluated using standard criteria. There were no significant differences in the number of biopsies that contained renal tissue, cortex, or medulla. Biopsies obtained with either instrument contained an adequate number of glomeruli and an equivalent number of arterioles and severity of tissue compression. Differences included easier penetration of the renal capsule and collection of sufficient tissue for interpretation with only one instrument pass when using the vacuum-assisted device (vs two passes required with the spring-loaded instrument). Before use in client-owned dogs, future studies should evaluate whether these differences are clinically relevant advantages in the diagnostic evaluation of dogs with kidney disease, and determine the prevalence and severity of complications when using this larger gauge device.

Bioaccumulation and biomagnification of polybrominated diphenyl ethers in a food web of Lake Michigan.

Polybrominated diphenyl ethers are hydrophobic chemicals and can biomagnify in food chains. Little is known about the biomagnification of PBDEs in the Lake Michigan food web. Plankton, Diporeia, lake whitefish, lake trout, and Chinook salmon were collected from Lake Michigan in 2006 between April and August. Fish liver and muscle and whole invertebrates were analyzed for six PBDEs (BDE-47, 99, 100, 153, 154, and 209). Carbon and nitrogen stable isotope ratios (delta(13)C and delta(15)N) were also quantified in order to establish the trophic structure of the food web. Geometric means of Sigma PBDE concentrations in fish ranged from 0.562 to 1.61 microg/g-lipid. BDE-209 concentrations ranged from 0.184 to 1.23 microg/g-lipid in all three fish species. Sigma BDE-47, 99, and 209 comprised 80-94% of Sigma PBDE molar concentration. Within each fish species, there were no significant differences in PBDE concentrations between liver and muscle. The highest concentration of BDE-209 (144 microg/g-lipid) was detected in Diporeia. Based on analysis of delta(15)N and PBDE concentrations, BDE-47 and 100 were found to biomagnify, whereas BDE-209 did not. A significant negative correlation between BDE-209 and trophic level was found in this food web. Biomagnification factors were also calculated and again BDE-47 and 100 biomagnified between food web members whereas BDE-209 did not. Diporeia could be one of the main dietary sources of BDE-209 for fish in Lake Michigan; BDE-47 and 100 biomagnified within this food chain; the concentration of BDE-209 decreased at higher trophic levels, suggesting partial uptake and/or biotransformation of BDE-209 in the Lake Michigan food web.

Bioaccumulation and biotransformation of decabromodiphenyl ether and effects on daily growth in juvenile lake whitefish (Coregonus clupeaformis).

Decabromodiphenyl ether (BDE 209) is the main congener in the commonly used commercial flame retardant mixture, "deca-BDE". There is evidence showing that fish can debrominate BDE 209 into potentially more toxic congeners. The objective of this study was to evaluate BDE 209 uptake and its potential effects on juvenile lake whitefish (Coregonus clupeaformis). Lake whitefish were fed BDE 209 at four nominal concentrations (control, 0.1, 1, and 2 microg/g-diet) for 30 days. Livers and carcasses were analyzed for 11 polybrominated diphenyl ether (PBDE) congeners (BDE 47, 99, 100, 153, 154, 196, 197, 206, 207, 208, and 209) and daily otolith increment width was measured as an estimate of growth before and after exposure. Four congeners (BDE 206, 207, 208, and 209) were detected in livers and carcasses. Hepatic BDE 209 concentrations in the 1 and 2 microg/g treatments were significantly higher than in the control group (1.25 and 5.80 nmol/g-lipid compared to 0.183 nmol/g-lipid). The concentration of BDE 209 detected in the tissues of the control group resulted from BDE 209 in the base diets. Concentrations of all congeners from the 1 and 2 microg/g groups were higher in livers than carcasses, indicating the liver was the primary organ of BDE 209 accumulation. Compared to the fraction in diets, the molar fraction of BDE 209 was lower in livers and carcasses, whereas the fractions of BDE 206, 207, and 208 were higher. These different distributions of PBDE congeners resulted from differential adsorption and metabolism. One congener, BDE 206, could be a major metabolite from BDE 209 debromination. Otolith increment widths were narrower in fish from the highest diet concentration administered, suggesting BDE 209 may have affected growth rates. In conclusion, this in vivo study with lake whitefish showed that BDE 209 was debrominated into lower PBDE congeners and that exposure to 2 microg/g may have affected fish growth.

Effect of furosemide and furosemide-carbazochrome combination on exercise-induced pulmonary hemorrhage in Standardbred racehorses.

The objective was to quantify the effect of furosemide and carbazochrome on exercise-induced pulmonary hemorrhage (EIPH) in Standardbred horses using red blood cell count and hemoglobin concentration in bronchoalveolar lavage (BAL) fluid. Six healthy Standardbred horses with prior evidence of EIPH performed a standardized treadmill test 4 h after administration of placebo, furosemide, or furosemide-carbazochrome combination. Red blood cell (RBC) counts and hemoglobin concentrations were determined on the BAL fluid. The RBC count in BAL ranges were (2903-26,025 cells/microL), (45-24,060 cells/microL), and (905-3045 cells/microL) for placebo, furosemide, and furosemide-carbazochrome, respectively. Hemoglobin concentration ranges were (0.03-0.59 mg/mL), (0.01-0.55 mg/mL), and (0.007-0.16 mg/mL) for placebo, furosemide, and furosemide-carbazochrome groups, respectively. No significant differences were detected among treatments. However, there was great variability among horses, suggesting that a larger sample size or better selection of horses was needed.

Toxicity of soybean rust fungicides to freshwater algae and Daphnia magna.

Soybeans are intensively grown over large swaths of land in the Midwestern US. Introduction of the pathogenic fungus responsible for Soybean Rust (Phakopsora pachyrhizi) will likely result in a significant increase in the environmental load of strobilurin and conazole fungicides. We determined the toxicity of six such fungicides to the unicellular algae Pseudokirchneriella subcapitata and the aquatic invertebrate, Daphnia magna. We found that levels of concern of some fungicides were lower than annual average runoff concentrations predicted for Indiana. Our results suggest that pyraclostrobin and propiconazole, and to a lesser extent tebuconazole, may cause impacts to algae and daphnids in areas where soybeans are intensively grown. More studies are needed to describe the ecological effects of sublethal exposures to these fungicides, as well as monitoring environmental concentrations in watersheds where these fungicides are applied to soybeans.

Seasonal energetics of northern phocid seals.

The metabolic rate of harp (Pagophilus groenlandicus), harbor (Phoca vitulina), and ringed seals (Pusa hispida) was measured at various temperatures in air and water to estimate basal metabolic rates (BMRs) in these species. The basal rate and body composition of three harp seals were also measured throughout the year to examine the extent to which they vary seasonally. Marine mammalian carnivores generally have BMRs that are over three times the rates expected from body mass in mammals generally, both as a response to a cold-water distribution and to carnivorous food habits with the basal rates of terrestrial carnivores averaging about 1.8 times the mean of mammals. Phocid seals, however, have basal rates of metabolism that are 30% lower than other marine carnivores. Captive seals undergo profound changes in body mass and food consumption throughout the year, and after accounting for changes in body mass, the lowest rate of food intake occurs in summer. Contrary to earlier observations, harp seals also have lower basal rates during summer than during winter, but the variation in BMR, relative to mass expectations, was not associated with changes in the size of fat deposits. The summer reduction in energy expenditure and food consumption correlated with a reduction in BMR. That is, changes in BMR account for a significant portion of the seasonal variation in energy expenditure in the harp seal. Changes in body mass of harp seals throughout the year were due not only to changes in the size of body fat deposits, but also to changes in lean body mass. These results suggest that bioenergetics models used to predict prey consumption by seals should include time-variant energy requirements.