bluuebunny/crossref_metadata_2025 huggingface dataset:
Power spectral analysis and digital filtration of brain stem auditory evoked potentials in dogs
Authors: Kawasaki Yasuaki , Inada Shichiro
Published: January 2024

Power spectral analysis and digital filtering of brain stem auditory evoked potentials (baep) were performed in dogs. The baep were recorded in 7 dogs, using alternating clicks at frequency of 20 Hz. The clicks were delivered monaurally at intensity of 90-dB normal hearing level. Power spectral analysis indicated that the frequency compositions of the averaged responses were divisible into 4 frequency bands: A (30 to 390 Hz), B (390 to 680 Hz), C (680 to 910 Hz) and D (910 to 1960 Hz).

The frequency limits of digital high-pass (hp) and low-pass (lp) filters, at which neither peak-to-peak nor absolute amplitudes were reduced, were 1,170 and 1,270 Hz for P1, 290 and 1,170 Hz for P2, 290 and 980 Hz for P3, 290 and 980 Hz for P4, and 200 and 880 Hz for P5, respectively. The dual structure of baep was confirmed in dogs. Below 200 Hz for the hp filter, peak-to-peak and absolute amplitudes of all waves were not significantly reduced. Therefore, this frequency may be a boundary frequency between low- and high-frequency components of baep in dogs. The main source for the high-frequency components that constituted each positive peak and the following trough was derived from frequency bands C and D.

The frequency limits of 200 Hz for a digital hp filter and of 1,270 Hz for a digital lp filter, at which amplitudes of all waves were not reduced, support the analog filter settings recommended for dogs (ie, ≤ 53 and 3,000 Hz for analog hp and lp filters, respectively).
Accumulation of allantoin and uric acid in plasma of exercising trotters
Authors: Räsänen Leena A. , Myllymäki Tuija , Hyyppä Seppo , Maisi Päivi , Pösö A. Reeta
Published: January 2024

Plasma concentrations of hypoxanthine, uric acid, and allantoin, which are breakdown products of adenine nucleotides, were measured in Standardbred and Finnhorse trotters during and after an exercise test on a high-speed treadmill, after an incremental exercise test performed on a racetrack, and after a racing competition. Fiber-type composition of the middle gluteal muscle and the muscle concentrations of adenine nucleotides and inosine monophosphate were measured after the racetrack test. Changes in the concentration of hypoxanthine were not observed in any of the tests. Peak concentration of uric acid was measured between 5 and 30 minutes after exercise, and it was three- to tenfold higher than the value at rest. The variability can be explained by intensity of the exercise test and variation among horses. The concentration of allantoin after exercise was 2 to 3 times as high as that at rest, depending on the intensity of the exercise, although the absolute increase was about 10 times as high as the increase in the concentration of uric acid. Peak values of allantoin for the treadmill and the racetrack tests were obtained 4 to 6 minutes after exercise and < 30 minutes after the races. Peak concentration of allantoin correlated positively with the percentage of type-II (IIA + IIB) fibers in the middle gluteal muscle. Significant correlations were not observed between plasma concentration of uric acid or allantoin and muscle concentrations of adenosine triphosphate (atp) or inosine monophosphate. It can be concluded that in horses, breakdown of atp during and after exercise continues until allantoin is produced. The peak concentration of allantoin increases with the intensity of exercise, is reached rapidly after exercise, and the variation in the time to the peak value is small among horses. It is suggested that the main source of allantoin is the fast-twitch, type-II fibers and that the mixed muscle concentrations of adenine nucleotides are of limited value when estimating the effects of exercise on atp content of the muscle tissue.
Glycoconjugates as components of receptors for Bordetella avium on the tracheal mucosa or turkeys
Authors: Arp L. H. , Huffman E. L. , Hellwig D. H.
Published: January 2024

Bordetella avium is an important respiratory tract pathogen of turkeys. In common with other pathogenic bordetellae, B avium manifests a tissue tropism for cilia of the respiratory tract epithelium. To determine the molecular characteristics of the host cell receptors for B avium, we used hemagglutination and in vivo adherence assays. Carbohydrates, mucus, sialic acid-specific lectin, and other glycoconjugates were evaluated for their ability to competitively inhibit binding of B avium to host cells. The gangliosides, GD1a and GT1b, completely inhibited hemagglutination, whereas N-acetylneuraminic acid (sialic acid) partially inhibited hemagglutination. Adherence to turkey tracheal mucosa in vivo was significantly (P < 0.01) inhibited by GD1a and GT1b gangliosides, N-acetylneuraminic acid, bovine submaxillary mucin, and horseshoe crab (Limulus polyphemus) lectin. Treatment of the tracheal mucosa with neuraminidase also inhibited adherence of B avium. We conclude that N-acetylneuraminic acid and the gangliosides, GD1a and GT1b, may be important components or the tracheal mucosa receptor for B avium in turkeys.
Organ distribution of avian polyomavirus DNA and virus-neutralizing antibody titers in healthy adult budgerigars
Authors: Phalen David N. , Wilson Van G. , Graham David L.
Published: January 2024

Tissue specimens and serum samples obtained from adult budgerigars in various stages of reproduction housed in an aviary with enzootic avian polyomavirus (apv) disease were examined by means of polymerase chain reaction techniques for apv dna. Although the birds were apparently healthy, apv dna could be detected in all 40 birds examined (inapparent infection rate, 100%). Viral dna was found in most organ systems examined. Analysis of data suggested that organ virus concentrations were lower in breeding than in nonbreeding birds.

Serum samples from 144 birds were examined for virus-neutralizing (vn) antibody. All serum samples had detectable vn antibody titers. Determining vn titer had a sensitivity of 100% for detection of apv infection in birds and was more sensitive than analysis of droppings by use of polymerase chain reaction techniques to detect apv infection in 6-month-old birds. Analysis of the data suggested that lower vn antibody titers were associated with longer duration of continuous breeding.
Effects of single intravenously administered doses of omeprazole and ranitidine on intragastric pH and plasma gastrin concentration in nonfed ponies
Authors: Baker Simon J. , Gerring E. Lawrence
Published: January 2024

We investigated the effects of a range of iv administered doses of omeprazole (0.125 to 2.0 mg/kg of body weight) on gastric pH (monitored by indwelling electrode) and plasma gastrin concentration, compared with those of iv administered ranitidine (1.0 mg/kg) in 4 Welsh mountain-type ponies. Pharmacokinetic variables of iv administered omeprazole also were examined. Episodes of high gastric pH in the basal state obscured the effect of acid suppression on intragastric pH; however, omeprazole induced dose-dependent increase in mean gastric pH (P < 0.01) during the 11 hours after its administration. In the presence of acid-suppressant treatment, plasma gastrin concentration correlated significantly with gastrie pH (Spearman's rank correlation coefficient, ρ = 0.445, P < 0.01), whereas basal pH and plasma gastrin concentration were not correlated. The effect was not great, and a dose-dependency was not found. Intravenously administered omeprazole was subject to two-compartment pharmacokinetics, and there was evidence for saturable steps in the redistribution and elimination phases. Dosage of 0.25 mg/kg induced approximately half-maximal inhibition of basal gastric pH in these ponies and was associated with area under the concentration vs time curve of 0.7 μmol·h/L, which corresponds reasonably with results of other species. Omeprazole may represent a useful alternative acid-suppressant agent in horses, but further work is required to relate the dose-dependent effects found in this study to well-defined targets of acid suppression in clinical cases.
Cardiopulmonary effects of positioning pregnant cows in dorsal recumbency during the third trimester
Authors: Dunlop Colin I. , Hodgson David S. , Smith John A. , Chapman Phillip L. , Tyler Liz M.
Published: January 2024

The uterine hemodynamic response to maternal positioning in dorsal recumbency was evaluated in 7 conscious pregnant cows during the third trimester. Anesthetic or sedative drugs were not administered. Uterine artery flow was measured, using a previously implanted ultrasonic flow probe. Catheters implanted in the uterine artery and vein were used for measurement of blood pressure and for blood sample collections. Heart rate, systemic arterial pressure, uterine arterial blood flow, arterial and venous oxygen and carbon dioxide tensions, and pH were measured in cows in standing position. Cows were cast with ropes and positioned in dorsal recumbency, then measurements were repeated at 15 and 30 minutes. Compared with standing measurements, dorsal recumbency caused 50% increase in heart rate and 44% increase in arterial blood pressure. Uterine artery flow did not change significantly. Despite increased ventilation, arterial oxygenation was reduced during dorsal recumbency. There were minimal differences between measurements at 15 and 30 minutes of dorsal recumbency.
Morphometric analysis of the foramen magnum in Pekingese dogs
Authors: Simoens Paul , Poels Patricia , Lauwers Henri
Published: January 2024

The size and shape of the foramen magnum were studied in skulls from 75 adult and 5 juvenile Pekingese dogs. After maceration of the skulls, the height, width, and area of each foramen magnum were measured, and various skull indices were determined. The shape of the foramen varied from ovoid to rectangular and had a dorsal notch in all but 2 skulls. Prolapse of cerebellum or brain stem through the enlarged opening was prevented by a fibrous membrane covering the dorsal notch. Mean ± sd area of the foramen was 138.1 ± 26.1 mm2; its mean total height was 15.0 ± 2.9 mm, and its mean maximal width was 13 3 ± 1.1 mm. Statistically, variability in the area of the foramen was mainly correlated with total height of the foramen, including the dorsal notch. Total height of the foramen was not correlated with age or gender.

The degree of dysplasia, notch index, and occipital index of each foramen magnum were determined. To allow a more accurate evaluation of the morphology of the foramen, the foramen magnum index, defined as the ratio between the maximal width and the total height of the foramen, was also computed. Mean ± sd foramen magnum index was 91.8 ± 17.1 in the adult Pekingese dogs. Foramen magnum index was not significantly correlated with age, but was significantly larger in male than in female dogs. The large variability in the shape and size of the foramen magnum and the absence of any neurologic problems in dogs of this study indicate that the dorsal notch of the foramen magnum in brachycephalic dogs is a normal morphologic variation, rather than a pathologic condition.
Neutrophil function and pathologic findings in Holstein calves with leukocyte adhesion deficiency
Authors: Nagahata Hajime , Kehrli Marcus E. , Murata Hideo , Okada Hiroyuki , Noda Hiroshi , Kociba Gary J.
Published: January 2024

Leukocyte adhesion deficiency was diagnosed in 4 Holstein calves from 1 to 4 months old. Calves had severe ulcers on oral mucous membranes, gingivitis, severe periodontitis, chronic pneumonia, and stunted growth associated with severe neutrophilia. Neutrophils from affected calves had function defect, characterized by severely decreased adherence, chemotactic movements, phagocytosis, luminol-dependent chemiluminescent response, and O-2-producing activities. Deficient CD18 expression (0.1 to 1.7%) on neutrophils was clearly detected by use of flow cytometric analysis. These affected calves were linked to a common ancestral sire that has been documented to be a carrier. Clinical features, leukocyte functional abnormalities, deficient expression of CD18, and mode of inheritance indicated that affected calves had leukocyte adhesion deficiency. In vitro leukocyte functional abnormalities were associated with deficiency in the expression of CD11/CD18. Pathologic findings indicated possible increased susceptibility to infection associated with this disease.
Reactivity of polyclonal human CD3 antiserum in lymphoid tissues of cattle, sheep, goats, rats and mice
Authors: Ramos-Vara J. A. , Miller M. A. , López E. , Prats N. , Brevik L.
Published: January 2024

Polyclonal rabbit antiserum to human T-cell CD3 was used to study its reactivity in lymphoid tissues (lymph nodes, spleen, aggregated lymphoid follicles [Peyer's patches], thymus) of several animal species (cattle, sheep, goats, rats, and mice). Using a peroxidase-antiperoxidase technique on formalin-fixed and paraffin-embedded tissues, immunoreactive cells were detected in T cell-dependent areas of the lymphoid tissues. Reactivity was high in all species tested, but mouse tissues had reduced reactivity, compared with the other species. To obtain a reaction, it was necessary to digest tissues with pronase before application of the immunocytochemical technique. Our results indicate that CD3 antiserum may specifically recognize T-lymphoid cells as it does in human lymphoid tissues and can be used as a marker to study physiologic and pathologic conditions of the lymphoid system of these species.
Exacerbated onset of dysentery in swine vaccinated with inactivated adjuvanted Serpulina hyodysenteriae
Authors: Olson LeRoy D. , Dayalu K. I. , Schlink Gerald T.
Published: January 2024

After oral challenge exposure with Serpulina hyodysenteriae-infected diced colon, fewer swine vaccinated with an experimental vaccine adjuvanted with mineral oil died (8 of 25 [32%]) than did nonvaccinated controls (6 of 15 [40%]), although the difference was not significant. However, onset and exacerbation of dysentery were accelerated in vaccinated swine because: 5 of the 8 dead vaccinated swine died before any of the nonvaccinates, which was significant (P<0.01); vaccinated swine that died were observed to have more hemorrhage in the feces, colonic mucosa, and colonic lumen than did nonvaccinated swine; and the earlier diarrhea onset in vaccinates, the more days of hemorrhagic diarrhea (P<0.05). Antibody titer in vaccinated swine immediately before challenge exposure that subsequently died was significantly (P<0.05) higher than that in vaccinated swine that recovered. Of of the 30 swine vaccinated with the experimental vaccine, 20 had dispersed droplets of mineral oil at the site of vaccination in the neck muscles and 3 swine had purulent abscesses at the injection site. It was concluded that vaccination with the experimental vaccine for controlling swine dysentery was ineffective.
Antipyrine and caffeine dispositions in clinically normal dogs and dogs with progressive liver disease
Authors: Boothe Dawn Merton , Cullen John Michael , Calvin James Arthur , Jenkins William Louis , Brown Scott Anthony , Green Robert Allan , Carrier Donald Earl
Published: January 2024

Dispositions of caffeine and antipyrine were compared as indicators of decreasing hepatic function in dogs with experimentally induced progressive liver disease. Dimethylnitrosamine, a hepatospecific toxin, was administered orally to 16 dogs; 6 dogs served as controls (group 1). Three classes of liver disease were defined by histologic features: mild (group 2; n = 5), moderate (group 3; n = 6), and severe (group 4; n = 5). Disposition of antipyrine, and 24 hours later, caffeine was studied 3 weeks after the last dose of toxin in each dog. For both drugs, rapid IV administration of 20 mg/kg of body weight was administered and serum samples were obtained at intervals for determination of at least 5 terminal-phase drug half-lives. For both drugs, clearance and mean residence time differed among groups (P ≤ 0.01). Clearance of antipyrine and caffeine was decreased in groups 3 and 4, compared with groups 1 and 2. Antipyrine and caffeine mean residence times were longer in group-3 dogs, compared with dogs of groups 1 and 2. Correction of caffeine and antipyrine clearances for hepatic weight increased discrimination between groups 3 and 4. The clearance and mean residence time ratios of antipyrine to caffeine were calculated for each group and, when compared with values for group-1 dogs, were used to test for differences between the 2 drugs in response to disease. Ratios did not differ among groups. These results indicate that the disposition of antipyrine and caffeine may change similarly with progression of dimethylnitrosamine-induced liver disease.
Effect of furosemide on plasma atrial natriuretic peptide and aldosterone concentrations and renin activity in running horses
Authors: Cooley J. L. , Hinchcliff K. W. , McKeever K. H. , Lamb D. R. , Muir W. W.
Published: January 2024

Effects of furosemide administration on exertion-induced changes in plasma renin activity and plasma concentrations of atrial natriuretic peptide and aldosterone in horses during sustained submaximal exertion were examined. Furosemide (1 mg/kg of body weight) or heparinized saline solution was administered iv to each of 6 mares not conditioned to exercise, either 4 hours or 2 minutes before 60 minutes of sustained submaximal running on a treadmill. Horses ran at a speed that induced heart rate approximately 65% of maximal after saline treatment. After 15 minutes of running, furosemide suppressed the exertion-induced increase in plasma concentrations of atrial natriuretic peptide (mean [95% confidence interval] values of 63.9 [9.9 to 421] pg/ml vs 100 [15.4 to 652] pg/ml after furosemide or saline treatment, respectively), and enhanced the response of plasma renin activity to exertion (18.6 [5.7 to 60.4] ng/ml/h vs 6.0 [1.8 to 19.4] ng/ml/h, respectively). An effect of furosemide on the exertion-induced increase in plasma aldosterone concentration was not detected.
Pharmacokinetics and tissue residues of spiramycin in cattle after intramuscular administration of multiple doses
Authors: Sanders Pascal , Guillot Philippe , Dagorn Michèle , Moulin Gérard , Delépine Bernard , Mourot Dominique
Published: January 2024

Pharmacokinetic variables of spiramycin and its distribution in muscle, liver, kidney, and injection sites were studied in 18 mixed-sex 1-year-old calves to assess drug withdrawal time after 2 IM administrations of 100,000 IU of spiramycin/kg of body weight at 48-hour intervals.

Presence of a compound, other than spiramycin I (ie, neospiramycin), was observed in tissues used for withdrawal time determination. High concentrations observed at the injection sites decreased slowly to maximal residue limit with half-life of 109.5 hours for neospiramycin and 77.5 hours for spiramycin. At 14 days, neospiramycin concentrations were higher in kidney than in liver and half-life was different between these 2 tissues.

Two methods of withdrawal time determination were used and the part of the samples without residue detected, in the calculation, was discussed. Withdrawal time of 35 days can be proposed on the basis of average daily intake determined for spiramycin, with concentration at injection sites representing 10% of the whole muscle concentration.
Effects of acetylpromazine, xylazine, and vertical load on digital arterial blood flow in horses
Authors: Hunt Robert J. , Brandon Christopher I. , McCann Margaret E.
Published: January 2024

Palmar digital arterial blood flow was measured in 6 conscious, standing horses, using surgically placed perivascular ultrasonic flow probes. The effects of 2 dosages of xylazine (0.55 and 1.1 mg/kg of body weight) and of 3 dosages of acetylpromazine (0.01, 0.02, and 0.04 mg/kg), as well as the effect of vertical load, on digital blood flow were evaluated. Intravenous administration of xylazine induced a significant (P < 0.05), transient decrease in digital blood flow. Intravenous administration of acetylpromazine induced a significant (P < 0.05), prolonged increase in digital blood flow. Correlation between vertical load and digital blood flow was found. The results of this study indicate that use of actylpromazine may be beneficial in clinical treatment of horses with reduced digital blood flow. Xylazine, on the other hand, may exacerbate ischemic conditions of the digit and should be used with caution.
Pharmacokinetic variables and bioavailabiljty from muscle of creatine kinase in cattle
Authors: Lefebvre Hervé P. , Toutain Pierre-Louis , Serthelon Jean-Paul , Lassourd Véronique , Gardey Laure , Braun Jean-Pierre
Published: January 2024

Pharmacokinetic variables of skeletal muscle creatine kinase (ck) activity after iv administration of a muscle extract; ck bioavailability after im administration of the muscle extract; and effect of im administration of saline solution, to appreciate the possible release of ck consecutive to muscle puncture, were determined in 6 cows. A general equation for the quantitative estimation of skeletal muscle damage also was derived.

Administration of saline solution im had no effect on plasma ck activity (anova, P > 0.05) in any of the cows. After iv administration of the muscle extract (150 U/kg of body weight), mean volume of the central compartment, plasma half-life, and plasma clearance of ck were 0.027 ± 0.007 L/kg, 520 ± 109 minutes, and 6.43 ± 2.29 ml/kg/h, respectively. After im administration (150 U/kg), mean bioavailability of ck was 51 ± 17% and maximal plasma ck activity (500 ± 97 U/L) was observed at 454 ± 131 minutes. The rate of ck activity entry into plasma was determined by use of deconvolution analysis. Two peaks were observed; the first appeared before the 30th minute after im administration, and the second appeared at 3.3 ± 1.1 hours. Amplitudes were 6.31 ± 4.45 and 6.57 ± 3.08 U/kg/h, for the first and the second peaks, respectively. The quantity of ck liberated from control muscle was 0.69 ± 0.12 U/kg/h, corresponding to a normal daily catabolism of 5.8 ± 1.0 mg of muscle/kg. From these results, the following equation can be proposed to determine the corresponding mean equivalent of destroyed muscle (Qmuscle, test article) after im administration of a test article:

Qmuscle, test article (g/kg) = 4.41 · 10-6. auc (U/h/L), with auc being the ck plasma activity area under the curve.
Effects of tumor necrosis factor on in vitro digital arterial responses in horses
Authors: Baxter Gary
Published: January 2024

Endotoxin given in vivo has been shown to inhibit endothelial dependent relaxation, and augment adrenergic (norepinephrine) contractions in isolated palmar digital arteries of horses. A study, using tumor necrosis factor (tnf) in vitro, was performed to determine the possible cause of these vascular alterations. Palmar digital arteries were surgically removed from 6 horses under general anesthesia, cut into 4-mm vascular rings (4 segments/horse), suspended in tissue baths, and attached to force displacement transducers for measurement of vascular tension. Four in vitro treatment groups were evaluated: group 1, control; group 2, tnf (5,100 pg of tnf/ml); group 3, 10 × tnf (10 times previous tnf concentration); group 4, tnf plus L-arginine (5,100 pg of tnf/ml and 10-6 M L-arginine). The appropriate drug(s) was/were added to each tissue bath 10 minutes before doseresponse tests were performed for acetylcholine, bradykinin, norepinephrine, and 5-hydroxytryptamine (serotonin). Concentrations needed to induce 50% maximal relaxation or contraction (ec50) and maximal percentage relaxation or contraction were determined. Arteries exposed to tnf (group 2) had significantly (P = 0.04) decreased maximal relaxation to acetylcholine and increased maximal contraction to norepinephrine, compared with Control arteries, but values did not differ from those for arteries of groups 3 and 4. Maximal relaxation to bradykinin or contraction to serotonin were not different between treatment groups. Mean ec50 values for bradykinin, norepinephrine, and serotonin did not differ among the 4 treatment groups. Mean ec50 values for arterial segments’ response to acetylcholine in group 4 were significantly (P = 0.04) increased, compared with control segments, but did not differ from those for segments of groups 2 and 3. The decreased endothelial dependent relaxation to acetylcholine and enhanced maximal contraction to norepinephrine were similar to vascular alterations caused by endotoxin, indicating that tnf may be responsible for endotoxin-induced vascular changes in vitro and in vivo in horses.
Efficacy of domperidone and sulpiride as treatments for fescue toxicosis in horses
Authors: Redmond Lisa M. , Cross Dee L. , Strickland James R. , Kennedy Sidney W.
Published: January 2024

We evaluated the effectiveness of 2 dopamine antagonists as treatments for fescue toxicosis in horses. Sixteen gravid mares were assigned by breed and expected foaling date to 1 of 3 treatment groups; endophyte-infested control; 1.1 mg of domperidone/kg of body weight/d; and 3.3 mg of sulpiride/kg/d. Mares were pastured on endophyte-infected fescue and received 0.454 kg of a corn and dried molasses carrier containing the drug treatment. Treatment started 30 days prior to expected foaling date and continued until parturition. Blood samples were collected, and mammary gland scores were recorded every 5 days. Body weight and body condition scores were obtained every 28 days. Serum was analyzed for prolactin, progesterone, and estradiol-17β concentrations. Domperidone-treated mares had shorter (P = 0.09) gestation duration and foaled closer (P = 0.07) to their expected parturition date than did control mares. Mammary gland scores were higher (P < 0.05) for domperidone-treated mares than for control mares. By 4 and 9 days after the start of treatment, serum prolactin concentration was higher (P < 0.05) in domperidone-treated mares and sulpiride-treated mares, respectively, than in control mares. Domperidone- and sulpiride-treated mares had higher (P < 0.05) serum progesterone and lower (P < 0.01) estradiol-l7β concentrations than did control mares. These results indicate that domperidone may offer considerable potential as a treatment for fescue toxicosis in horses.
Temporal changes in concentrations of amino acids in plasma and whole blood of healthy neonatal foals from birth to two days of age
Authors: Zicker Steven C. , Rogers Quinton R.
Published: January 2024

Temporal changes, as well as differences in distribution, in concentrations of 24 amino acids in plasma and whole blood of neonatal foals were determined from birth to 2 days of age. In addition, differences in concentrations of amino acids in plasma between mare and foal pairs were determined at birth. Significant (P < 0.05) hypoaminoacidemia existed for 15 amino acids in plasma of foals at birth, compared with mares (paired t-test). Concentrations of 7 amino acids (aspartate, glutamate, glutamine, glycine, hydroxyproline, phenylalanine, proline) in plasma of foals were higher (P < 0.05) at birth than in mares, and concentrations of 2 (taurine, tryptophan) were not different (P > 0.05). Significant (P < 0.05) temporal changes for concentrations of 19 of 24 amino acids in plasma were observed during the 48-hour period. Concentrations of 13 of the 19 amino acids in plasma that had significant changes were higher (P < 0.05) at 48 hours. Significant (P > 0.05) effect of time on concentration of 5 amino acids (alanine, methionine, phenylalanine, taurine, threonine) in plasma was not found after birth. Temporal changes in concentrations of 7 amino acids (alanine, asparagine, glutamine, histidine, hydroxyproline, methionine, and threonine) in whole blood were not significantly (P > 0.05) different from those in plasma. Temporal changes for concentrations of the remaining 17 amino acids in whole blood were significantly (P < 0.05) different, compared with plasma. Distribution of the concentrations of 18 amino acids between whole blood and plasma was significantly (P < 0.05) different. Concentrations of 5 amino acids (citrulline, cystine, glutamine, methionine, tryptophan) were significantly (P < 0.05) lower in whole blood than in plasma, whereas concentrations of 13 amino acids were significantly (P < 0.05) higher in whole blood vs plasma. Concentrations of 6 amino acids (asparagine, isoleucine, leucine, proline, serine, valine) in whole blood were not significantly different from concentrations in plasma. Significant differences in temporal patterns of concentrations of amino adds in plasma and whole blood may be attributable to nutritional or physiologic changes associated with parturition. Significant differences between concentrations of amino acids in whole blood and plasma may be attributable to ontogeny or specificity of transport systems across cell membranes.
Effects of polymyxin B and Salmonella typhimurium antiserum on horses given endotoxin intravenously
Authors: Durando Mary M. , MacKay Robert J. , Linda Stephen , Skelley Leslie A.
Published: January 2024

Polymyxin B and an antiserum against an Re mutant Salmonella typhimurium were evaluated for protective effect in an equine model of endotoxemia. Six 3- to 5-month-old foals were given endotoxin (0.25 μg/kg of body weight) iv after no pretreatment, or pretreatment with polymyxin B (6,000 U/kg, iv) or S typhimurium antiserum (1.5 ml/kg, iv). When given without pretreatment, endotoxin caused transient recumbency and increases in rectal temperature, and heart and respiratory rates. In addition, leukopenia and increases in circulating tumor necrosis factor (tnf) and interleukin 6 (il-6) activities were detected. Compared with results obtained when endotoxin was given alone, pretreatment with polymyxin B resulted in significantly (P < 0.05) lower maximal plasma tnf and il-6 activities, and significantly lower rectal temperature and respiratory rate. In contrast, compared with effects of endotoxin given without pretreatment, use of antiserum was associated with significantly (P < 0.05) higher respiratory rate, maximal plasma il-6 activity, and total tnf response (as determined by areas under curves of plasma tnf vs time). These results indicate that polymyxin B may have potential as a treatment for equine endotoxemia. Salmonella typhimurium antiserum had no positive effect in this model, and, under certain conditions, may exacerbate the actions of endotoxin.
Hemolytic complement activity and concentrations of its third component during maturation of the immune response in colostrum-deprived foals
Authors: Bernoco Marietta M. , Liu Irwin K. M. , Willits Neil H.
Published: January 2024

Six foals were deprived of colostrum for the first 36 hours after birth and, instead, received reconstituted powdered milk. Five control foals suckled their dams naturally. Blood samples were obtained from all the foals after birth and at approximately weekly intervals until at least 5.5 months of age. Sera were analyzed for hemolytic complement activity, complement component C3, and correlating IgG concentration. Hemolytic complement (P = 0.0145) and C3 (P = 0.0002) values were significantly higher in colostrum-deprived foals (cdf) than in naturally nursed foals at 2 to 5 days of age. In addition, significantly (P = 0.0149) higher IgG concentration was found in cdf than in naturally nursed foals between 3 and 5.5 months of age. It was concluded that the observed high complement activity in cdf within 2 to 5 days of age may provide an alternative in immune defense for IgG-deprived foals after failure of colostral transfer.
Use of polymerase chain reaction to detect swine influenza virus in nasal swab specimens
Authors: Schorr Erica , Wentworth David , Hinshaw Virginia S.
Published: January 2024

Rapid and accurate detection of a virus in a population is a critical factor in the eventual treatment and/or control of the virus. In this study, we examined use of the polymerase chain reaction (pcr) to detect swine influenza virus in nasal swab specimens from infected pigs. This approach was first standardized, using viral rna purified by guanidinium/phenol-chloroform extraction and placed in the same transport medium as the swabs. By using highly conserved primers for the swine H1 hemagglutinin, we amplified a 591-base pair fragment that was analyzed by use of agarose gel electrophoresis, Southern blot, and dna sequencing.

To evaluate pcr as a potential diagnostic tool for detection of swine influenza virus infection, we obtained nasal swab specimens from experimentally infected pigs. Amplification by pcr and reamplification of extracted samples with internal primers yielded detectable bands for an amount of virus less than that required to infect embryonating chicken eggs. We also tested swab specimens from pigs involved in 3 separate, natural episodes of swine influenza. These swab specimens were extracted, amplified and reamplified, producing visible bands on the gel and in Southern blots. We performed Southern blot analyses on all pcr products, to confirm that they were from viral H1 rna. We also cloned and sequenced a 591-base pair product from 1 specimen and found that it was 100% identical to the hemagglutinin gene sequence of A/Sw/Ind/1726/88. Results indicate that pcr can be used to detect swine influenza virus, even in nasal swab specimens, the specimen typically collected for diagnosis of virus infection.
Effects of Tamm-Horsfall glycoprotein and albumin on struvite crystal growth in urine of cats
Authors: Buffington C. A. , Blaisdell Jean L. , Sako Toshinori
Published: January 2024

Tamm-Horsfall protein (thp) was isolated and purified, using pooled urine collections from clinically normal cats. The effects of feline thp and purified feline serum albumin on urine chemical and struvite crystal variables were compared, using an in vitro crystal growth system and 24-hour samples of pooled urine obtained from 4 cats. Urine samples were placed in wells of cell culture plates, increasing concentrations of ammonium hydroxide were added to adjacent wells to stimulate struvite crystal growth, and the plates were incubated at 37 C. The effect of albumin and thp on crystal growth in sample wells was compared with that in control wells, without protein addition, in the same plate. Crystal growth was assessed by determination of number of crystals and supersaturation index, a scale of crystal habit at different degrees of supersaturation, by use of direct visualization with an inverted microscope. Albumin addition did not have significant effect on either crystal number or supersaturation, compared with controls. Addition of thp significantly (P < 0.05) increased crystal number and supersaturation index. It was concluded that thp significantly (P < 0.05) promoted growth of struvite crystals in feline urine, and thus, may have a role in feline struvite uroliths and struvite urethral plug formation.
Pathogenicity of a bovine attaching effacing Escherichia coli isolate lacking Shiga-like toxins
Authors: Fischer John , Maddox Carol , Moxley Rodney , Kinden Darrel , Miller Margaret
Published: January 2024

Escherichia coli isolate 7996-90, obtained from a calf with diarrhea, had negative results of tests for K-88, K-99, 987P, F41, CS31A, F1845, F165 or E coli adherence factor adhesins and had negative results of tests for the toxins heat-labile, heat-stable A, heatstable B, Shiga-like toxin (slt)-I or slt-II. Strain 7996-90 had localized adherence to HEp-2 cells, caused actin rearrangement in host cells to which it adhered, hybridized with the eaeA probe, and produced the 94-kd outer membrane protein associated with attaching effacing lesions. This isolate caused attaching effacing lesions in Caco-2 cell polar monolayers, rabbit intestinal loops, and the intestines of gnotobiotic pigs. The isolate belongs to serotype O26:NM and is considered a class-II attaching effacing enteropathogenic E coli. Until recent addition of more sensitive assays at veterinary diagnostic laboratories, isolates such as 7996-90 were not readily recognized as pathogens because they failed to fit into the enterohemorrhagic E coli group, members of which, be definition, produce slt. The assays described can facilitate diagnosis of attaching effacing E coli infection when histologic evaluation is hampered by autolysis.
Hepatic total 3α-hydroxy bile acids concentration and enzyme activities in prednisone-treated dogs
Authors: Salter Philip F. , Hoffmann Walter E. , Chambers Mark D. , Schaeffer David J. , Kuhlenschmidt Mark S.
Published: January 2024

High serum alkaline phosphatase (alp) activity is considered a sensitive marker of cholestasis in most mammalian species, including dogs. Induction of high serum alp activity in association with cholestasis is dependent on high hepatic bile acids concentrations. Treatment of dogs with glucocorticoids also results in high serum alp activity. The possible causal relation between serum alp activity and bile acids concentration was investigated in dogs treated with glucocorticoids. The relation of glucocorticoid treatment to changes in the activity of individual alp isoenzymes, alanine transaminase (alt) and γ-glutamyltransferase (ggt) also was investigated.

Eight conditioned dogs were given 4 mg of prednisone/kg of body weight, im, daily for 10 days. Blood samples were taken prior to treatment and on treatment days 3, 5, 7, and 10. Liver tissue was then taken from each dog. Serum total alp activity was significantly (P < 0.05) high at day 3 in prednisone-treated dogs. Isoenzyme analysis indicated that this increase was attributable to an increase in the liver alp isoenzyme (LALP). Significant increases in serum corticosteroid-induced alp (calp) and bone alp were first observed on days 7 and 10, respectively. Serum alt and ggt activities were significantly increased by day 5. Increased serum or hepatic tissue bile acids concentrations were not observed in prednisonetreated dogs, compared with values in 8 clinically normal (control) dogs, but were high in 3 dogs with complete bile duct ligation.

Hepatic activities of LALP, calp, and ggt were higher in prednisone-treated dogs than values in controls, indicating probable increased hepatic synthesis of these enzymes. Hepatic alt activity was not increased. The ratio of serum to tissue lalp activity was increased in prednisone-treated dogs, compared with values in controls, indicating that lalp may have been preferentially released into serum. There was no difference in the ratio of serum to liver ggt activity between prednisone-treated dogs and controls. The lalp and ggt ratios were increased in bile duct-obstruction dogs.

It was concluded that, although lalp is the principal alp isoenzyme in serum during the first 10 days of prednisone treatment, hepatic bile acid concentrations are not increased and, therefore, are not likely to be responsible for induction and release of alp into serum. Prednisone may, therefore, be directly responsible for induction of alp activity in dogs treated thusly.
Radiologic evaluation of the liver and gastrointestinal tract in rats infected with Taenia taeniaeformis
Authors: Perry Ruby L. , Williams Jeffrey F. , Carrig Colin B. , Kaneene John B. , Schillhorn van Veen Tjaart W.
Published: January 2024

In rats infected with the cestode Taenia taeniaeformis, hepatomegaly results from development of parasitic cysts in the liver. Diffuse nodular mucosal hyperplasia in the glandular region (corpus and antrum) of the stomach, and gross thickening of the intestinal mucosa also result. Between postinfection days (PID) 21 and 84, radiologic observations were made after oral administration of a barium sulfate suspension in T taeniaeformis-infected rats and in age/sex-matched controls. There was radiographic evidence of hepatic enlargement at PID 21. Enlargement of the gastric folds was first observed along the greater curvature of the stomach at PID 35. Fimbriation of small intestinal mucosal surfaces resulted from thickening of the intestinal villi and was observed in the duodenum at PID 21. Intestinal motility was assessed, and contractions were counted, using image intensification fluoroscopy, then were recorded on videotape. There were no significant differences between control and infected rats for gastric emptying time, intestinal transit time, and number of intestinal contractions per minute. Barium contrast radiography clearly indicated large gastric folds, thickening of the small intestinal villi, and hepatic enlargement, and was useful for assessing gastrointestinal motility.
Sheep as maintenance host for Leptospira interrogans serovar hardjo subtype hardjobovis
Authors: Gerritsen Marijke J. , Koopmans Metje J. , Peterse Dirk , Olyhoek Tom
Published: January 2024

Transmission of Leptospira interrogans serovar hardjo subtype hardjobovis from naturally infected sheep to uninfected sheep and calves was studied. A microscopic agglutination test and ELISA were used to determine specific antibody responses in serum. Polymerase chain reaction was used to detect bacterial shedding in urine. Six sheep were derived from a dairy farm where cows were infected with L hardjobovis. Three of these sheep were seropositive for L hardjobovis, and 1 also shed leptospires in the urine. The other 2 sheep shed leptospires in the urine 7 days after the first observation date. The 6 sheep were placed on an isolated pasture together with a second group of 6 noninfected sheep. During the observation period of 140 days, 1 sheep of the second group became infected with L hardjobovis. On 5 consecutive days, a urine mixture from the 4 infected sheep was sprayed on the heads of 4 noninfected calves. Within 56 days, all calves that had been sprayed with urine shed L hardjobovis in the urine and became seropositive for L hardjobovis.
Effects of aging and dietary protein intake on uninephrectomized geriatric dogs
Authors: Finco Delmar R. , Brawn Scott Alan , Crowell Wayne A. , Brown Cathy A. , Barsanti Jeanne A. , Carey Daniel P. , Hirakawa Diane A.
Published: January 2024

Thirty-one clinically normal Cocker Spaniels, Miniature Schnauzers, and Doberman Pinschers (28 female, 3 male) 7 to 8 years old were uninephrectomized (month −2) to increase the risk of renal damage associated with reduction of renal mass. Two diets, differing principally in protein concentration, were used to test the hypothesis that high dietary protein intake causes renal damage in aging dogs.

For 2 months after uninephrectomy, all dogs were fed diet A (18% protein). After glomerular filtration rate (gfr) was measured (month 0), 16 dogs were assigned to group A and were fed diet A for an additional 48 months. The other 15 dogs were assigned to group B, and were fed diet B (34% protein) for the subsequent 48 months. At 6-month intervals, GFR and urine protein-to-creatinine ratio (UP/C) were determined. At 48 months, terminal studies were done, survivors were euthanatized, and tissues were examined.

Of 16 dogs in group A, 10 survived, compared with 13 of 15 in group B. Among survivors, a significant difference in GFR was not found between groups A and B, and decrease in GFR was not evident with time in either group. At 48 months, oral administration of casein caused minor acute effects on GFR and renal plasma flow in dogs of groups A and B.

The UP/C values increased significantly (P = 0.001) from baseline values, but the increase was not progressive. The UP/C values were not affected by diet. Some dogs in both groups developed UP/C > 1.0.

Morphologic studies performed on kidneys removed at -2 months (nephrectomy) and at 48 months (necropsy) revealed increased kidney weight in both groups at month 48, compared with month −2 (P = 0.003); at month 48, kidney weight change was significantly (P = 0.004) greater in group-B than in group-A dogs. Increased glomerular area at month 48, compared with month −2, was significantly (P = 0.000) related to time, but not to diet.

Significant (P = 0.000) increase in glomerular mesangial matrix, interstitial fibrosis (P = 0.001), cell infiltration (P = 0.000), and lesions of the renal pelvis (P = 0.04) was observed between month −2 and month 48. Time, representing combined effects of uninephrectomy and aging, was the major factor responsible for the morphologic changes. Diet effects were significance (P = 0.008) for cell infiltration, but did not reach significance for mesangial matrix accumulation, fibrosis, or pelvic lesions. Kidney mineral analysis revealed no renal mineralization in either group between −2 and 48 months.

Results indicated that GFR did not decrease with time during the geriatric peroid studied, but severity of renal lesions was increased. Effects of time and uninephrectomy, although not separable, were more important than those of dietary protein intake on progression of renal lesions.
In vitro comparison of the effect of parallel and divergent transfixation pins on breaking strength of equine third metacarpal bones
Authors: McClure Scott R. , Watkins Jeffrey P. , Ashman Richard B.
Published: January 2024

Breaking strength (torque at failure) of equine third metacarpal bones, with transfixation pins placed parallel in the frontal plane and 30° divergent from the frontal plane, was determined in vitro. Two transfixation pins were placed through the distal metaphysis, using a jig designed to drill the holes in the assigned configuration. Paired metacarpal bones II through IV from 12 horses were tested in torsion. The torsional moment of the force applied through the transfixation pins at failure was compared for each limb. Metacarpal bones with divergent pins were significantly (P = 0.030) stronger, compared with those with parallel pins. Metacarpal bones with parallel pins failed with longitudinal oblique fractures through a proximal bone-pin interface, whereas those with divergent pins failed with more comminuted fractures through multiple bone-pin interfaces.
Quantitative assessment of aerial ammonia toxicity to the nasal mucosa by use of the nasal lavage method in pigs
Authors: Urbain Bruno , Gustin Pascal , Prouvost Jean-François , Ansay Michel
Published: January 2024

Effects of atmospheric ammonia (NH3) on the nasal mucosa and somatic growth were investigated in pigs exposed to 4 NH3 concentrations (0; 25; 50; and 100 ppm) for 6 days in a specifically designed air-pollutant exposure chamber. Nasal lavage (nal) was applied to quantify the ammonia-induced inflammatory response by measuring the number of neutrophils and the albumin (porcine serum albumin) concentration in the nal liquid. In control pigs, these variables remained unchanged throughout the exposure period. In all other groups, an important ammonia concentration-related increase was recorded. The equation of the linear regression line established between the mean values of the number of neutrophils (× 103) per milliliter of nal liquid (y) recorded at the end of the exposure period and the ammonia concentrations (ppm) was: y = 69.7 + 3.3 [NH3] (r = 0.979; P < 0.020). The increase in the neutrophil count was significant (P< 0.05) at concentrations as low as 25 ppm. For albumin concentration nanograms per milliliter, the corresponding equation was: y = 574 + 14.3 [NH3] (r = 0.953; P < 0.045). However, the first significant change (P< 0.05) in this variable was only obtained for the higher concentration (100 ppm). In exposed pigs, a concentration-related depression of somatic growth was observed. The equation of the regression line plotted relating the individual values of the changes in body weight gain recorded over the exposure period expressed as percentage of the initial body weight (y) and the ammonia concentration was: y = 3.507 ? 0.203 [NH3] + 0.001 [NH3]2 (r = 0.55; P< 0.010). The decrease in the somatic growth was significant (P< 0.05) at concentrations as low as 25 ppm. We conclude that biochemical and cytologic analysis of nal fluid is a good tool for quantifying the effects of atmospheric pollutants in pigs, a 6-day exposure to ammonia induces nasal irritation and depression of somatic growth at concentrations as low as 25 ppm.