bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of intravenous administration of hydroxyethyl-starch-deferoxamine on oxygen-derived free radical generation in cancellous bone specimens obtained from dogs
Authors: Lewis Daniel D. , Church Daniel F. , Hosgood Giselle 
Published: January 2024

Summary
The ability of iv administered hydroxyethyl-starch-deferoxamine to attenuate radical production in freshly procured cancellous bone specimens was investigated, using spin-trapping and electron spin resonance (esr) techniques. A core cancellous bone specimen 10 mm long and 5.6 mm in diameter was obtained, using aseptic technique, from the proximal portion of the humerus of 30 adult mixed-breed dogs. After procurement of the initial bone specimen, 10 dogs received a 10 % solution of hydroxyethyl-starch-deferoxamine in 0.9% NaCl (50 mg/kg of body weight, iv), 10 dogs received an equivalent volume (5 ml/kg, iv) of a 10% solution of hydroxyethyl-starch in 0.9 % NaCl, and 10 dogs received 0.9 % saline solution (5 ml/kg, iv). A second core cancellous bone specimen was obtained from the contralateral humerus of each dog 45 minutes after treatment. All specimens were individually incubated in the spin trap α-phenyl-N-tert-butylnitrone in Eagle's minimum essential medium, at 26 C for 45 minutes, then were frozen at -20 C until they were prepared for analysis by esr spectroscopy. Each specimen was thawed, homogenized, and extracted in a low-dielectric organic solvent prior to obtaining an esr spectrum, which was analyzed for hyperfine splitting constants for radical identification. Each first-derivative spectrum was digitally double-integrated to obtain an area; these areas were used to compare intensities of the spin adducts. Difference in the area obtained before and after treatment for each dog was expressed as a ratio of that dog's pretreatment area ([pretreatment-posttreatment ]/pretreatment). The calculated ratios for saline-, hydroxyethyl-starch-, and hydroxyethyl-starch-deferoxamine-treated dogs were compared, using a Kruskal-Wallis (KW) nonparametric test for multiple comparisons of ranked data. Significance was determined at P ≤ 0.05. Ad hoc comparisons were performed, using the KW procedure for individual comparisons, with a set at 0.05.
The mean ± sd and median ratio for each of the treatment groups were: saline-treated dogs, 0.005 ± 0.40 and 0.045; hydroxyethyl-starch-treated dogs, -0.063 0.27 and -0.025; hydroxyethyl-starch-deferoxamine-treated dogs, 0.261 ± 0.278 and 0.335, respectively. There was a significant (P < 0.01, KW) difference in the ratios between treatment groups. Ratios for hydroxyethyl-starch-deferoxamine-treated dogs were significantly (P < 0.05, KW) higher than that for hydroxyethyl-starch-treated dogs but not for saline-treated dogs. The ratios for saline- and hydroxyethyl-starch-treated dogs were not significantly different. We could not associate significant attenuation of radical generation in freshly harvested core cancellous bone specimens with iv administration of hydroxyethyl-starch-deferoxamine. The potential for unconjugated hydroxyethyl-starch to function as an oxidant must considered.
Pathologic findings of experimentally induced Streptococcus uberis infection in the mammary gland of cows
Authors: Thomas Lewis H. , Haider Wolfram , Hill Alan W. , Cook Roy S. 
Published: January 2024

Summary
Twenty-five quarters of 12 daily cows, 3 to 8 years old, with a bacteriologic history of freedom from infection with Streptococcus uberis were inoculated via the teat canal with S uberis (23 quarters) or sterile medium (2 quarters). The cows were sent to slaughter 1, 3, or 6 days later. Acute inflammatory response involving accumulation of large numbers of polymorphonuclear, neutrophilic leukocytes (neutrophils) in the secretory acini was recognized after 24 hours in infected cows. After 6 days, the neutrophil response was still evident, but infiltration of septa by lymphocytes, septal edema, extensive vacuolation of secretory cells, focal necrosis of alveoli, small outgrowths of the secretory and ductular epithelium, and widespread hypertrophy of the ductular epithelium also were recognized. Early stages of involution and fibrosis also were evident at that stage. Streptococci were identified by immunoperoxidase labeling, free or phagocytosed, in macrophages; in the alveolar lumina, adherent to damaged secretory or ductular epithelium; in the subepithelium and septal tissue; and in lymphatic vessels and lymph nodes. The importance of the macrophage as the primary phagocytic cell is highlighted, and doubt is cast on the value of the exuberant neutrophil response by the host in defense of the gland.
Changes in renal function associated with treatment of hyperthyroidism in cats
Authors: Graves Thomas K. , Olivier N. Bari , Nachreiner Ray F. , Kruger John M. , Walshaw Richard , Stickle Russ L. 
Published: January 2024

Summary
We measured glomerular filtration rate (gfr) estimated by plasma disappearance of 99mTc-labeled diethylenetriaminepentaacetic acid, serum concentrations of thyroxine (T4), creatinine, and urea nitrogen, and urine specific gravity in 13 cats with naturally acquired hyperthyroidism before and 30 days after treatment by bilateral thyroidectomy, and in a group of 11 control cats. Mean (±sd) serum T4 concentration decreased from a pretreatment value of 120.46 (± 39.21) nmol/L to a posttreatment value of 12.15 (± 6.26) nmol/L (P < 0.0001; reference range, 10 to 48 nmol/L). Treatment of hyperthyroidism resulted in a decrease in mean (± sd) glomerular filtration rate, from 2.51 (± 0.69) ml/kg of body weight/min to a posttreatment value of 1.40 (± 0.41) ml/kg/min (P < 0.0001). Mean serum creatinine concentration increased from 1.26 (± 0.34) mg/dl to 2.05 (± 0.60) mg/dl (P < 0.01). Mean serum urea nitrogen concentration increased from 26.62 (± 6.83) mg/dl to a mean postthyroidectomy concentration of 34.92 (± 8.95) mg/dl (P < 0.01). All changes were significant. Two cats developed overt renal azotemia after treatment of hyperthyroidism. Our results provide further evidence that treatment of hyperthyroidism can result in impaired renal function. In addition, our results suggest that, in some instances, thyrotoxicosis might mask underlying chronic renal insufficiency.
Effects of chloramphenicol on infusion pharmacokinetics of propofol in Greyhounds
Authors: Mandsager Ronald E. , Clarke Cyril R. , Shawley Richard V. , Hague Christinia M. 
Published: January 2024

SUMMARY
To investigate the effect of chloramphenicol, a cytochrome P-450 inhibitor, on the pharmacokinetics of propofol, either chloramphenicol (50 mg/kg of body weight, iv) or saline solution was administered iv to 5 Greyhounds in randomized manner, with at least 2 weeks between trials. Thirty minutes after either chloramphenicol or saline treatment, a bolus dose of propofol (10 mg/kg, iv) was administered, followed by a 2-hour infusion of propofol (0.4 mg/kg/min, iv). Samples for determination of blood propofol concentration were collected sequentially over a 6-hour period during each trial. After termination of propofol infusion, the time to spontaneous head lift, extubation, sternal recumbency, and standing was recorded. Blood propofol concentration was determined by use of high-performance liquid chromatography. Concentration-time data were fitted to a two-compartment open pharmacokinetic model and pharmacokinetic variables were determined, using a microcomputer program for modeling and simulation of concentration-time data. The effect of chloramphenicol on the pharmacokinetics of propofol and recovery time were evaluated, using paired t-tests and Wilcoxon's test for parameters that are not normally distributed (t½(β), Vd(ss), ClB). Significant (P < 0.05) effects of chloramphenicol pretreatment included increased t1/2(β) (by 209%), and decreased ClB (by 45%), and prolonged recovery indices (by 768 to 946%). These results indicate that cytochrome P-450 metabolic pathways have an important role in propofol clearance and propofol anesthetic recovery in Greyhounds.
Serum swainsonine concentration and α-mannosidase activity in cattle and sheep ingesting Oxytropis sericea and Astragalus lentiginosus (locoweeds)
Authors: Stegelmeier Bryan L. , James Lynn F. , Panter Kip E. , Molyneux Russell J. 
Published: January 2024

SUMMARY
Serum α-mannosidase activity and swainsonine concentration were determined in 4 cattle and 15 sheep (3 groups of 5 each) that were administered ground locoweed (Oxytropis sericea or Astragalus lentiginosus) containing swainsonine at dosages of approximately 0.8 mg/kg of body weight/d (cows, 30 days each) and 0, 1.0, and 1.5 mg/kg/d (sheep, 11 days each). The cattle developed mild clinical signs of locoism, including signs of depression, lethargy, and slight intention tremors. Clinical signs of toxicosis were not observed in the sheep. Within 24 hours of initial treatment, serum α-mannosidase activity in cows and sheep, measured by the release of 4-methylumbelliferone from an artificial substrate, was markedly decreased to 28 and 40 μmol of 4-methylumbelliferone/L, respectively. Mean serum α-mannosidase activity of control cows and sheep was 400 ± 94 and 422 ± 42 (mean ± sd), respectively. In the treated animals, decreased serum α-mannosidase activities returned to normal or higher activities within 6 days after treatment was discontinued. Using a jack bean α-mannosidase assay, increased swainsonine activity (153, 209, and 381 ng/ml, respectively) was detected in the serum of cattle and of sheep in the high- and low-dose groups within 24 hours after treatment with locoweed. Swainsonine concentration remained high, with mean concentrations of 204, 432, and 395 ng/ml (cows and 2 sheep groups, respectively) during the treatment period. After treatment, swainsonine was rapidly cleared, with estimated serum half-life of 16.4, 17.6, and 20.3 hours (cows, and high- and low-dose sheep groups, respectively). Significant differences in either α-mannosidase activity or swainsonine concentration were not detected between the 2 groups of treated sheep. These results suggest that serum α-mannosidase and swainsonine values are sensitive indicators of locoweed intoxication in cattle and sheep. Furthermore, it suggests that swainsonine is rapidly absorbed, resulting in rapid inhibition of serum α-mannosidase activity, leading to high serum swainsonine concentration. After exposure is eliminated, swainsonine is rapidly cleared from the serum, with serum α-mannosidase activity returning to normal values shortly thereafter.
Fluid, electrolyte, and packed cell volume shifts in racing Greyhounds
Authors: Toll P. W. , Gaehtgens P. , Neuhaus D. , Pieschl R. L. , Fedde M. R. 
Published: January 2024

SUMMARY
Arterial blood samples were obtained at rest, just before, and 5 minutes after a 704-m race, to quantify changes in hematologic variables, plasma electrolyte and protein concentrations, osmolality, and acid/base variables. Changes in plasma volume were estimated from the change in plasma protein concentration. Immediately prior to the race, plasma volume decreased by 10% from rest and total circulating rbc volume increased by 60%, attributable to increased rbc number rather than size. Increases in blood volume (VB) by 24% and pcv by 29% also were detected before the race. Five minutes after the race, plasma volume was 21% below the resting value and total circulating rbc volume had increased 73% above the resting value, resulting in a 40% increase in pcv. Contraction of the spleen appeared responsible for increased pcv and VB before the race and maintenance of VB after the race.
Plasma chloride concentration was the same before and after the race; the chloride content of the plasma decreased by the same fraction (22%) as did the plasma volume, indicating Cl- loss from the plasma. Plasma Na+ content decreased by a smaller fraction (13%), causing Na+ concentration to increase from 151 mEq/L at rest to 167 mEq/L after the race. Assuming that Na+ concentration was the same throughout the extracellular fluid, H2O likely moved into the intracellular compartment. As a consequence of these changes, the inorganic strong ion difference in plasma increased by about 16 mEq/L, tending to minimize the acid/base disturbance induced by the 33 mEq/L increase in lactate concentration.
Results indicated that the physiologic changes taking effect during strenuous sprint exercise in Greyhounds enhance blood volume and aid in acid/base homeostasis, both of which are adaptive for this type of exercise.
Prophylactic effect of dietary zinc in a laboratory mouse model of swine dysentery
Authors: Zhang Peng , Duhamel Gerald E. , Mysore Jagannatha V. , Carlson Michael P. , Schneider Norman R. 
Published: January 2024

SUMMARY
Reduced prevalence of diarrhea and mortality has been reported after dietary supplementation with zinc compounds in swine with naturally acquired colibacillosis and those challenge-exposed with Serpulina hyodysenteriae; however, the usefulness of this approach for control of enteric diseases of swine remains to be determined. To examine the effect of dietary zinc-containing compounds on the colonization and development of cecal lesions associated with S hyodysenteriae infection, a defined diet alone or with added ZnO, ZnSO4, or Zn-methionine complex to a final concentration of approximately 6,000 mg of Zn2+/kg of complete feed was fed ad libitum to 156 female mice (strain C3H/HeN) for 10 days prior to oral inoculation either with S hyodysenteriae or sterile trypticase soy broth. Rations were continued for 42 days, while at weekly intervals, 3 mice/group were necropsied for determination of body weight, cecal weight, liver zinc concentration, presence of S hyodysenteriae in the cecum, and gross and histologic assessments of cecal lesions. From postinoculation day 0 to 42, the liver zinc concentration of mice fed the zinc-supplemented diets was approximately twice that of mice fed the basal diet, irrespective of the source of zinc. From postinoculation day 7 through 42, the overall recovery rate of S hyodysenteriae in infected mice fed the basal diet was 77.8%. In contrast, recovery rates of S hyodysenteriae from S hyodysenteriae-inoculated mice fed the zinc-supplemented diets were 0% for Zn-methionine and ZnO and 16.7% for ZnSO4. Mice fed the basal diet had significantly (P < 0.05) higher weight gain than mice fed the zinc-supplemented diets. However, the severity of cecal lesions, as determined by histologic examination and quantitative determination of longitudinal crypt length of the cecum was significantly (P < 0.05) less in mice fed the zinc-supplemented diets than in mice fed the basal diet. Data from this study indicate that dietary supplementation with 6,000 mg of zinc/kg of feed significantly reduced the recovery rate of S hyodysenteriae and provided partial protection against development of cecal lesions in mice inoculated with S hyodysenteriae. However, at this concentration, zinc had a deleterious effect on growth of the mice.
Effect of methacholine on mucociliary transport in bovine trachea in vitro
Authors: Mars Maria H. , Henricks Paul A. J. , Hajer Rob , Breukink Henk J. 
Published: January 2024

Abstract
A method is described to evaluate pharmacologic influence on bovine tracheal mucus transport in vitro. In this model, cholinergic agonist methacholine stimulated transport velocity. Methacholine at concentration of 10−6M increased velocity by 13.6%, whereas 10−5M increased velocity by 26%. Stimulation was inhibited by atropine.
Electrophysiologic evaluation of the phrenic nerve-diaphragm pathway in an intact, conscious calf model
Authors: Desmecht Daniel J.-M. , Linden Annick S. , Lekeux Pierre M. 
Published: January 2024

SUMMARY
Owing to technical and ethical limitations, a substantial part of the knowledge about the pathophysiologic mechanism of the human diaphragm has been obtained from studies in which phrenic nerve activation was usually carried out by direct surgical exposure of the nerves in the neck of deeply anesthetized, mechanically ventilated animals. Novel information has been gleaned from such studies, but the restrictive conditions under which it was collected preclude reliable extrapolation. We, therefore, addressed the question of whether accurate electrophysiologic evaluation of the phrenic nerve-diaphragm pathway can be performed in intact, nonanesthetized calves.
Transjugular phrenic activation was well tolerated, safe, specific, and able to achieve constant symmetric and supramaximal phrenic stimulations during prolonged periods. Eighteen noninvasive cutaneous and esophageal reception circuits were tested for their ability to record the diaphragmatic evoked potential. In addition, they were compared for specificity and reproducibility of the recorded potentials during prolonged periods of tidal or stimulated respiration. The best diaphragmatic potential was recorded from surface electrodes attached to the skin of the ninth and tenth intercostal spaces, using a xyphoidian reference.
We describe a method that allows easy, longterm, and reliable electrophysiologic evaluation of the phrenic nerve-diaphragm pathway in intact, conscious calves. It is hoped that such a model will produce relevant novel information regarding pathophysiology of the diaphragm.
Assessment of the effectiveness of vaccination against pseudorabies in finishing pigs
Authors: Stegeman Arjan , Van Nes Arie , de Jong Mart C. M. , Bolder Freddie W. M. M. 
Published: January 2024

SUMMARY
Whereas the clinical efficacy of vaccination against pseudorabies has been studied extensively, methods to evaluate the influence of vaccination on pseudorabies virus (prv) transmission have only recently become available. In this study, prv transmission and growth performance in finishing pigs vaccinated either once or twice were compared.
The incidence of prv infections was significantly (P = 0.039) higher in the group vaccinated once (38%) than in the group vaccinated twice (10%). The reproduction ratio R, which is defined as the average number of new infections caused by 1 infectious individual, was estimated in both groups. This ratio was also significantly (P = 0.025) higher among single vaccinated pigs (R = 3.4) than among pigs that had received double vaccination (R = 1.5). In compartments where serologic evidence of prv introduction was observed, the mean daily weight gain was significantly (P = 0.029) lower in pigs vaccinated once (698 g/d) than in pigs vaccinated twice (721 g/d).
Results of this study document the possibility to objectively evaluate the effect of vaccination on prv transmission under field conditions. From the results, we concluded that double vaccination is advantageous in populations of finishing pigs at risk for prv introduction. However, even among pigs vaccinated twice, extensive spread of prv can occur.
Response to demineralized bone matrix implantation in foals and adult horses
Authors: Douglas Janet , Clarke Andrew 
Published: January 2024

SUMMARY
Equine demineralized bone matrix, particle size 2 to 4 mm, was implanted sc and IM in 4 foals and 4 adult horses. The implants were removed between 5 and 8 weeks after implantation. Bone formation was induced by sc and IM implantations in all animals. The implantation site had a marked effect on the amount of bone that developed, bone being formed earlier and in greater amounts when the matrix was implanted IM. The amount of bone formed increased with increasing time after matrix implantation at both sites. Demineralized bone matrix implantation also led to formation of small amounts of chondroid tissue; this tissue was more common in IM than sc matrix implants, and increased in amount with increasing time after implantation. Formation of this chondroid tissue did not precede the formation of bone, and there was no evidence that implantation of demineralized bone matrix in horses induced endochondral ossification. Age of the host did not appear to affect the response.
Abortion in heifers inoculated with a thymidine kinase-negative recombinant of bovine herpesvirus 1
Authors: Miller Janice M. , Whetstone Cecelia A. , Bello Leonard J. , Lawrence William C. , Whitbeck J. Charles 
Published: January 2024

SUMMARY
The Cooper isolate of bovine herpesvirus 1 (bhv-1) was used to produce a thymidine kinase-negative ( tk−) recombinant by insertion of a β-galactosidase (bgal) expression cassette into the tk coding region. The recombinant virus (tk− bgal+) was tested for abortifacient activity in cattle by inoculation of 5 pregnant heifers at 25 to 29 weeks gestation. Five additional heifers were inoculated with the Cooper tk−positive ( tk+) virus to serve as controls. After inoculation, both groups of heifers developed similar febrile responses and neutralizing antibody titers. Virus was isolated from blood of all heifers during the first postinoculation (pi) week, and isolation frequencies were similar for both groups. In contrast, whereas virus was isolated from many of the nasal and vaginal swab specimens of heifers inoculated with tk+ virus, only rare virus isolations were made from the heifers given tk− bgal+ virus. All heifers inoculated with tk+ virus aborted between pidays 19 and 35. The finding of characteristic microscopic lesions and viral antigen in fetal tissues indicated that the abortions were caused by bhv-1 infection. Virus was isolated from 3 fetuses, and all isolates were tk+. Two heifers inoculated with tk− bgal+ virus aborted at PI days 25 and 39. Fetal tissues had typical bhv-1 microscopic lesions and viral antigen. Virus was isolated from blood of both fetuses, and the isolates were tk− bgal+. Results of this study indicate that inactivation of the tk gene reduces, but does not eliminate, the abortifacient activity of bhv-1.
Influence of two amounts of dietary casein on uric acid, sodium urate, and ammonium urate urinary activity product ratios of healthy Beagles
Authors: Bartges Joseph W. , Osborne Carl A. , Felice Lawrence J. , Brown Charles , Allen Timothy A. , Koehler Lori , Unger Lisa , Bird Kathy , Chen Menglan 
Published: January 2024

SUMMARY
Casein has been used as a protein source in diets designed to dissolve canine ammonium urate uroliths and to prevent their recurrence, because it contains fewer purine precursors than do many other sources of protein. However, an important question is whether reduced quantities of dietary casein have any benefit in modifying saturation of urine with urates. To answer this question, activity productd ratios of uric acid, sodium urate, and ammonium urate were determined in 24-hour urine samples produced by 6 healthy Beagles during periods of consumption of a 10.4% protein, casein-based (10.4% casein) diet and a 20.8% protein, casein-based (20.8% casein) diet. Significantly lower activity product. ratios of uric acid, sodium urate, and ammonium urate were observed when dogs consumed the 10.4% casein diet. Significantly lower 24-hour urinary excretions of ammonia and phosphorus were observed when dogs consumed the 10.4% casein diet. Twenty-four-hour urinary excretions of magnesium and 24-hour urine pH values were significantly higher when dogs were fed the 10.4% casein diet. These results suggest that use of the 10.4% casein diet in protocols designed for dissolution and prevention of uric acid, sodium urate, and ammonium urate uroliths in dogs may be beneficial.