bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of lymphocyte function during vitamin A deficiency
Authors: Butera Salvatore T. , Krakowka Steven
Published: February 2025

Two variables of immune status were measured in vitamin A-deficient (A −), vitamin A-sufficient pair-fed (A + PF), and healthy control (A +) rats to examine the mechanisms of immune regulation by vitamin A. Parallel samples were run in bovine fetal serum (bfs)-containing medium and serum-free medium to control bfs-origin vitamin A in the cultures. Splenocytes derived from A − rats showed significantly depressed blastogenic response to all lectins tested in both mediums when compared with responses of A + PF and A + rats. The splenocyte blastogenic response of A + PF rats was significantly lower than that of A + (control) rats only when cultured in bfs medium and stimulated by lentil lectin, lipopolysaccharide, or concanavalin A mitogens. Thymic lymphocyte blastogenic transformation assays were equivocal. Splenic immunosuppression could not be linked to significant reductions in surface glycoprotein receptor availability, since splenocytes of A − rats, as well as thymocytes, were capable of binding fluorescein isothiocyanate-conjugated lectins in the same capacity as splenocytes of A + and A + PF rats. The combination of depressed cellular function and adequate lectin binding to viable cells implies that the regulation of immunohomeostasis by vitamin A was achieved through intracellular mechanisms, possibly selective genomic expression.
Enhanced resistance to listeriosis induced in mice by preinoculation treatment with T-2 mycotoxin
Authors: Corrier Donald E. , Ziprin Richard L.
Published: February 2025

The effect of T-2 toxin on cell-mediated resistance to bacterial infection was evaluated in mice challenge exposed with Listeria monocytogenes. Mice were treated orally on days −5, −4, −3, −2, −1, +1, and +3 with 2.0, 1.0, 0.5, or 0 mg of T-2 toxin/kg of body weight and were exposed to 106 (ld100) or 105 (ld50) L monocytogenes by intraperitoneal injection on day 0. Necrosis and depletion of lymphocytes in the thymus and spleen, decrease in thymus weight, reductions in the number of circulating total leukocytes and lymphocytes, and necrotizing gastroenteritis occurred in the toxin-treated mice. Although the cytotoxic effect of T-2 toxin on lymphoid tissue was marked, enhanced resistance to Listeria infection was revealed by significant (P < 0.01) decreases in mortality caused by listeriosis in the toxin-treated mice. Mortality decreased from 100% to 64% in the mice exposed to 106 Listeria and from 50% to 20% in the mice exposed to 105 Listeria. Percentage of mortality after Listeria challenge exposure was dependent on the T-2 toxin dose and was progressively decreased in the mice given 0.5, 1.0, or 2.0 mg of toxin/kg.
Anti-strongyle activity of a propylene glycol-glycerol formal formulation of ivermectin in horses (mares)
Authors: DiPietro J. A. , Todd K. S. , Reuter V.
Published: February 2025

Four groups of 10 horses (mares) each were treated with a 1% solution of ivermectin (200 μg/kg of body weight) in a propylene glycol-glycerol formal base orally, a 1% solution of ivermectin (200 μg/kg) in a propylene glycol-glycerol formal base via nasogastric tube, a 1.87% paste of ivermectin (200 μg/kg) orally, or a 22.7% paste of oxibendazole (10 mg/kg) orally. Fecal examinations were done before treatment and on posttreatment days (ptd) 14, 28, 42, 56, and 70. Strongyle egg per gram counts and sugar flotation fecal examinations were performed. Results of fecal examinations before treatment were similar in all horses. All horses treated with ivermectin had similar percentages of reductions in mean strongyle egg per gram counts after treatment; 100% on ptd 14, 28, and 56 and 93.4% to 98.7% on ptd 70. All ivermectin treatment groups had 0 horses detected as passing strongyle eggs on ptd 14 and 28, 0 to 2 on ptd 42, 3 to 5 on ptd 56, and 8 to 9 on ptd 70. Horses treated with oxibendazole had 99.9%, 99.7%, 92.9%, 78.6%, and 54.5% reductions in mean strongyle egg per gram counts and 5, 7, 8, 9, and 9 horses detected as passing strongyle eggs on ptd 14, 28, 42, 56, and 70, respectively. Adverse reactions to treatment were not observed.
Blood, urine, and ruminal fluid changes associated with metabolic alkalosis induced by duodenal obstruction
Authors: Avery T. B. , Nagaraja T. G. , Frey R. A.
Published: February 2025

Two Holstein heifers and a steer fitted with ruminal and duodenal cannulas were used to determine acid-base and electrolyte changes associated with metabolic alkalosis induced by duodenal obstruction. Obstruction was induced distally to the pylorus, but proximally to the common bile duct entrance. Ruminal fluid, blood, and urine samples were obtained before and after obstruction was induced. Duodenal obstruction resulted in increased blood pH, bicarbonate concentration, and base-excess values. Severe hypochloremia and hypokalemia were evident in 48 hours. Serum sodium concentration decreased only slightly. Packed cell volume and serum concentrations of urea nitrogen, creatinine, glucose, and inorganic phosphate increased, whereas calcium concentration showed no change. Renal chloride excretion reached near zero in 24 hours, whereas sodium and potassium excretions decreased in the steer, but were unchanged in the heifers. Urine creatinine concentration increased markedly in the heifers and steers. Acid urine was not evident up to 96 hours. Ruminal fluid pH decreased and chloride concentration increased in the steer, but remained unaffected in the heifers. Duodenal obstruction had no effect on rumen sodium, calcium, and magnesium concentrations, but the potassium concentration increased in the heifers. The degrees of alkalosis and electrolyte changes were greater in the steer than in the heifers.
Histopathologic and antibody responses of rabbits exposed to aerosols containing spores of Aspergillus fumigatus: Comparison of single and multiple exposures
Authors: Thurston J. R. , Peden W. M. , Driftmier Κ. M. , Richard J. L.
Published: February 2025

Resistance to pulmonary aspergillosis was studied in groups of rabbits exposed to aerosolized spores of Aspergillus fumigatus for 15 minutes on successive days for a total of 10, 7, or 4 exposures or a single exposure. The results of the study demonstrated that exposure of rabbits to spores for 15 minutes on 10 successive days did not result in an accumulation of viable spores in excess of those present in the lungs of rabbits exposed a single time. The tissue response in the lungs of the rabbits exposed at multiple times was more intense than that in the rabbits exposed once, but resolution of the lesions occurred similarly in terms of time and completeness of resolution. The duration of the antibody response as determined by a passive hemagglutination test and by enzyme-linked immunosorbent assay correlated with the number of exposures to spores, in that rabbits exposed 10 or 7 times to aerosolized spores remained positive longer than did those exposed fewer times. The results of the precipitin tests in agar gel were negative in all the rabbits but one.
Comparative changes in a rat liver abscess model induced with three Fusobacterium necrophorum strains
Authors: Scanlan C. M. , Berg J. N.
Published: February 2025

Viable cultures of 3 bovine Fusobacterium necrophorum strains were inoculated into the hepatic portal veins of rats. The experimentally produced hepatic necrobacillosis lesions were examined beginning at 15 minutes after inoculation was done and continuing for 4 weeks. Fusobacterium necrophorum 2101 (FN 2101), a biotype A, was the most virulent; F necrophorum 2030 (FN 2030), a biotype AB, was of intermediate virulence; and F necrophorum 2035 (FN 2035), a biotype B, was the least virulent. Gross lesions were first observed at 2, 8, and 18 hours after inoculation in the FN 2101-, FN 2030-, and FN 2035-inoculated rats, respectively. Gross and histopathologic descriptions of the FN 2101 and FN 2030 hepatic necrobacillosis lesions were similar, but were markedly different from those of the FN 2035 lesions. Abscesses produced by FN 2101 and FN 2030 attained maximal diameter (1 cm) in the hepatic parenchyma. Subcapsular abscesses were produced by FN 2035 and attained a diameter of 2 to 3 mm (maximal).
Cloacal papillomas in psittacines
Authors: Sundberg John P. , Junge Randall E. , O'Banion M. Kerry , Basgall Edward J. , Harrison Greg , Herron Alan J. , Shivaprasad H. L.
Published: February 2025

Papilloma-like masses affecting the cloaca of 19 Amazons, 16 macaws, 3 parrots, 1 conure, and 1 parakeet were examined. Papillomatous lesions were characterized by proliferation of the lining epithelium on thin fibrovascular stalks. Carcinoma in situ was diagnosed in the cloaca of a macaw in addition to the other 16 macaws with papillomas. Papillomavirus group-specific antigens were not detected in any of the 41 lesions, using the peroxidase-antiperoxidase technique. The DNA extracts from 6 different frozen papillomas did not contain papillomavirus genomes detectable by Southern blot hybridization, using an African gray parrot cutaneous papillomavirus as a probe. Evidence of an infective agent was not found by electron microscopic examination of 8 of the papillomas. Inoculations of partially purified homogenates of a cloacal papilloma from a yellow-crowned Amazon did not induce lesion formation on cloacal mucosa of an adult yellow-crowned Amazon, green and yellow macaw, sulphur-crested cockatoo, or mollucan cockatoo.
Bovine longissimus muscle glycogen concentration in response to isometric contraction and exogenous epinephrine
Authors: Crouse J. D. , Smith S. B.
Published: February 2025

Isometric contraction was elicited in cattle by electrical stimulation (electrical immobilization) and was used as a means of investigating the interaction between muscle contraction and epinephrine-induced muscle glycogen degradation. At 0.5 and 24 hours after a 15-minute period of continuous muscle contraction, glycogen content of longissimus muscle specimens collected via needle biopsy was not different from precontraction concentrations. Epinephrine (13.2 mg/kg of body weight) given subcutaneously resulted in a 30% to 35% reduction of muscle glycogen. Reduction of muscle glycogen was slightly greater when epinephrine was used in conjunction with isometric contraction, compared with epinephrine treatment alone. Muscle glycogen increased, and free glucose, lactate, and glucose-6-phosphate decreased, with increases in body weight. In younger, lighter cattle (370 kg), epinephrine decreased muscle glycogen and lactate concentrations and generally decreased muscle glucose concentrations. Muscle-free glucose and lactate concentrations were increased in older, heavier cattle (446 kg) by contraction and epinephrine injection when the animals were immobilized for 30 minutes, with intermittent periods of muscle relaxation. In these cattle, muscle glycogen concentration slightly decreased with isometric contraction. Data indicate that reports of increased glycogenolysis observed in cattle subjected to stress by mixing strange animals or exercise is due to dynamic muscle contraction and not due to isometric muscle contraction.
Equine endothelial cells in vitro
Authors: Lamar C. H. , Turek J. J. , Bottoms G. D. , Fessler J. F.
Published: February 2025

Certain in vitro culture conditions were determined for equine endothelial cells obtained from the aorta and pulmonary arteries. Cells were enzymatically isolated from the vessel lumen, using clostridial collagenase (2.5 mg/ml of Hanks's balanced salt solution) incubated at 37 C for 30 minutes. Cells were cultured in α minimum essential medium supplemented with plasma-derived and nonplasma-derived bovine fetal sera, endothelial cell-growth supplement, heparin, and antibiotics. Smooth muscle cell growth was not inhibited with nonplasma-derived animal sera, plasma-derived equine serum, or heparin. Heparin and a serum replacement were toxic to the cells used in the present study. Statistically significant differences were not found between the various media supplements.
Plasmid profiles of Moraxella bovis isolates
Authors: McDonald Timothy J. , Pugh George W.
Published: February 2025

Two-hundred isolates of Moraxella bovis were selected at random and examined for the presence of plasmid DNA by a rapid alkaline-detergent lysis method. All isolates contained from 1 to 6 plasmids, with varying agarose-gel electrophoretic migration patterns. Most (80%) isolates carried 2 to 4 plasmids, which ranged in molecular weight from 2.6 to 80 megadaltons. Seemingly, plasmid profiles can be used as a simple, reliable epizootiologic tool to establish a strain identification scheme for M bovis.
Upper airway obstruction in canine laryngeal paralysis
Authors: Amis Terence C. , Smith M. M. , Gaber C. E. , Kurpershoek C.
Published: February 2025

The type and the severity of airway obstruction in 30 dogs with bilateral laryngeal paralysis was assessed, using tidal breathing flow-volume loop (tbfvl) analysis. The dogs had clinical evidence of mild-to-severe upper airway obstruction (ie, respiratory distress, exercise intolerance, stridor). Seventeen dogs had tbfvl consistent with a non-fixed (inspiratory) obstruction, 10 had tbfvl indicative of a fixed (inspiratory/expiratory) obstruction, and 3 had normal tbfvl. Analysis of tbfvl confirmed that dogs with laryngeal paralysis have upper airway obstruction that differs in type and severity. Use of tbfvl provided a quantitative evaluation of airway obstruction and demonstrated the effects of bilateral laryngeal paralysis on the breathing patterns of dogs.
Techniques for isolation and performance of the perfused guinea pig working heart
Authors: Liu C. T.
Published: February 2025

This study demonstrated new approaches which enabled evaluating the work performance in both ventricles of an isolated guinea pig heart. By changing the right atrial filling pressure (rafp, preload) from 6 to 20 mm of Hg at a constant aortic pressure (Pa, 20 mm of Hg), cardiac output, stroke volume, aortic flow, coronary flow, cardiac work, O2 consumption, CO2 output, as well as end-diastolic ventricular, and pulmonary arterial pressures increased. Cardiac contractility and both ventricular systolic pressures reached peak values between 12 and 14 mm of Hg of rafp and then gradually decreased. With graded increases of Pa (afterload) from 10 to 45 mm of Hg at a fixed rafp (8 mm of Hg), coronary flow, cardiac contractility, cardiac work, cardiac O2 consumption, glucose utilization rate, and pulmonary arterial and both ventricular systolic pressures increased. Although aortic flow decreased with an increase in Pa, cardiac output, stroke volume, and coronary resistance did not show significant changes. Furthermore, cardiac mechanical efficiency decreased with an increase of pre- or afterload of the perfused isolated heart. These findings indicate that the total working heart model is suitable for studying cardiac functions.
Prevalence of Toxoplasma gondii antibodies in southern Louisiana swine in 1980 and 1981
Authors: Hugh-Jones M. E. , Broussard J. J. , Stewart T. B. , Raby C. , Morrison J. E.
Published: February 2025

Sera from 1,219 pigs slaughtered in southern Louisiana in 1980 and 1981 were tested, using the indirect hemagglutination test and microtitration system, for Toxoplasma gondii antibodies; 19.19% had titers of ≥ 1:64. Pigs slaughtered in the colder months, November to March, had significantly higher seroprevalences than did pigs slaughtered in the warmer months. Examination of blood samples from 236 sows and gilts on 52 farms revealed a seroprevalence of 24.6%.
Trypanosoma cruzi from wild raccoons in Oklahoma
Authors: John D. T. , Hoppe K. L.
Published: February 2025

Trypomastigotes of Trypanosoma cruzi were detected in the blood of 5 of 8 wild adult raccoons which were live-trapped in Tulsa, Okla. Organisms were isolated in diphasic blood agar medium and maintained in Vero cell cultures. Inoculated mice exhibited transient parasitemias without tissue involvement. Amastigote forms occurred within Vero cells. This is the first report of naturally occurring T cruzi infection of wild mammals in Oklahoma.
Test of the sheep ked Melophagus ovinus (L) as a vector of Anaplasma ovis Lestoquard
Authors: Zaugg J. L. , Coan M. E.
Published: February 2025

The sheep ked Melophagus ovinus was evaluated as a possible vector of Anaplasma ovis. In 4 tests, 45 to 293 keds were transferred from sheep with acute anaplasmosis, low level parasitemia, or carrier state of anaplasmosis to individual splenectomized ewes. Keds were confined in stockinette cages attached to the dorsal midline of the recipient hosts for 10 days. Throughout the 90-day observation periods after the keds were transferred, no clinical, serologic, or hematologic evidence of anaplasmosis was detected in any of the ked-recipient ewes. Results indicate that sheep keds probably are not mechanical or biological vectors of the ovine anaplasmosis organism.
Plasma cortisol and norepinephrine concentrations in castrated male pigs maintained in pairs in outdoor pens and in a confinement finishing house: Assessment of stress
Authors: Benson G. J. , Langner P. H. , Thurmon J. C. , Nelson D. R. , Neff-Davis C. , Davis L. E. , Tranquilli W. J. , Gustafsson B. K.
Published: February 2025

A catheter-backpack system was developed for repeated blood collection in pigs. Castrated male pigs (n = 12) were maintained in pairs in outdoor pens and later in a slotted-floor confinement finishing house. Blood collection required no restraint and appeared to be stress free. Serum cortisol concentration was unchanged by mode of maintenance. However, diurnal variation of cortisol was more pronounced when pigs were housed. A significant decrease (P < 0.05) in serum norepinephrine concentration occurred during the housing period.
Electroretinogram and visual-evoked potential measurements in Holstein cows
Authors: Strain George M. , Olcott Bruce M. , Hokett Laura D.
Published: February 2025

The electroretinogram (erg) and flash visual-evoked potential (fvep) were recorded from 25 Holstein cows in a clinical setting without dark adaptation. Latencies to the a and b waves, and the peak-to-peak amplitude between the a and b waves of the erg were measured bilaterally. The erg recordings were between the lower eyelid of the stimulated eye and the vertex, with ground on the nuchal crest. Stimuli for erg and fvep were 1.5 flashes of white light/s. Recorded erg were highly consistent and repeatable. The average latencies for the a and b waves were 14 and 30 ms; the mean ab amplitude was 43 μV. The fvep were recorded bilaterally between the middle of the interocular line and the midpoint of the nuchal crest, with ground on the vertex. The fvep measurements included latencies to 5 alternating positive and negative peaks (P1, N1, P2, N2, and P3) and 4 peak-to-peak amplitudes (P1 to N1, N1 to P2, P2 to N2, and N2 to P3). The P2 peak was consistently the most prominent. Average latencies for the 5 peaks were 46, 64, 86, 106, and 137 ms for P1, N1, P2, N2, and P3, respectively. The fvep peak-to-peak amplitudes had a high variability.
Detecting Mycoplasma bovis in milk by enzyme-linked immunosorbent assay, using monoclonal antibodies
Authors: Boothby J. T. , Mueller R. , Jasper D. E. , Thomas C. B.
Published: February 2025

Enzyme-linked immunosorbent assay, using monoclonal antibodies, was used to detect Mycoplasma bovis in milk samples from a dairy experiencing an epizootic of mastitis. This method was specific (100%) for M bovis. Broth enrichment increased the sensitivity from 65% to 86%, compared with standard culture methods.
Ultrastructural histochemical evaluation of growth plate cartilage matrix from healthy and osteochondritic swine
Authors: Farnum Cornelia E. , Wilsman Norman J.
Published: February 2025

A contributing factor to the lack of understanding the cause of osteochondritic syndromes has been incomplete knowledge of the morphology of lesions in subclinical stages of the disease. In osteochondritic growth plate cartilage from growing swine, the morphology of the pericellular matrix surrounding hypertrophic zone chondrocytes is abnormal and is characteristic of a matrix in which the ordered interactions of matrix macromolecules with each other and with the plasma membrane have been altered. In the present study, ultrastructural histochemical techniques were used to analyze the nature of macromolecular interactions in the pericellular matrix in normal growth plate cartilage, and selective enzyme digestions of normal growth plate cartilage were used to simulate the morphology found in osteochondritic lesions. Results showed that a pericellular macromolecular material which was both ferrocyanide positive and trypsin sensitive was essential for stabilizing the cell membrane/pericellular interface in normal growth plates. The highly variable morphology of this same material in osteochondritic lesions was simulated by hyaluronidase digestion. Since similar pericellular matrix abnormalities have not been described in other diseases of growth plate cartilage, they may represent a matrix abnormality unique to the vascularization failure of osteochondritic syndromes. Our ability to simulate the ultrastructural morphology of subclinical osteochondritic lesions enhances the potential for understanding the macromolecular changes found in the pericellular matrix of osteochondritic cartilage. Based on these results, a new hypothesis is presented for the early sequence of events in the pathogenesis of osteochondrosis.
Relationship of serum and plasma copper and ceruloplasmin concentrations of cattle and the effects of whole blood sample storage
Authors: Kincaid Ronald L. , Gay Clive C. , Krieger Robert I.
Published: February 2025

The present study was conducted to determine whether plasma and serum copper and ceruloplasmin concentrations in cattle are different and whether transport of samples with storage on ice before centrifugation affects the measurements. Mean copper and ceruloplasmin values were higher in plasma than in serum. Linear regressions were plasma copper (μg/ml) = 1.200 serum copper −0.032 (r2 = 0.99), serum ceruloplasmin (mg/dl) = 14.0 serum copper + 2.34 (r2 = 0.48), and plasma ceruloplasmin (mg/dl) = 18.2 plasma copper + 2.1 (r2 = 0.43). The percentage of copper associated with ceruloplasmin was less in serum (55%) than in plasma (66%).

Storage of blood samples on ice for 3 days decreased serum copper value by 3.5%. Linear regressions to correct for storage effects were corrected serum copper = 1.11 stored serum copper −0.04 (r2 = 0.94) and corrected plasma copper = 1.22 stored plasma copper − 0.17 (r2 = 0.86).

A cuproprotein may be involved in the blood clotting process, and some ceruloplasmin and its copper are apparently trapped in the fibrin clot, causing less copper in serum, compared with that in plasma. The difference between plasma and serum copper concentrations of calves was slightly increased by dietary copper supplementation.
Dural sinuses in the pig and their extracranial venous connections
Authors: Ghoshal Nani G. , Zguigal Hadhoum
Published: February 2025

The dural sinuses of the pig and their connections with veins of the head and neck have been described. The rostral epidural rete mirabile and the cavernous venous sinus complex have been described in detail, and speculation about their possible role in brain temperature regulation was made.
Clinical and pathologic changes in experimentally induced acute pancreatitis in cats
Authors: Kitchell Barbara E. , Strombeck Donald R. , Cullen John , Harrold Doris
Published: February 2025

Acute pancreatitis was induced in 6 cats by infusion of oleic acid into the pancreatic duct. Clinical changes included fever, tachycardia, and variable degrees of abdominal pain; vomiting occurred rarely, and diarrhea was not noted. Serum lipase activities were significantly increased through the 4th day after the surgical operation, although amylase activities were significantly decreased during most of the acute phase. Serum calcium and phosphate concentrations were decreased significantly on the 4th day after surgical operation. Hematologic alterations included normocytic, normochromic, responsive anemias, but changes in wbc values were not statistically significant. Evidence of exocrine pancreatic insufficiency after induction of acute pancreatitis was not demonstrated in any cats during the study. The results of this study indicate that increases in serum lipase activity are the most consistent and earliest indicators of acute pancreatitis in cats, but that more sensitive methods of laboratory evaluation should be sought.
Evaluation of leukapheresis and thrombocytapheresis in the horse
Authors: Gordon B. J. , Latimer K. S. , Murray C. M. , Moore J. N.
Published: February 2025

Continuous-flow centrifugation leukapheresis techniques were used to collect 300-ml volumes of leukocyterich plasma from 5 nonmedicated horses and from 5 corticosteroid-stimulated horses. White blood cell counts and differential counts were performed on the horses before (base line) and up to 48 hours after leukapheresis. Systemic administration of hydrocortisone increased numbers of total wbc and neutrophils and improved harvest of these cells. Nonmedicated horses had a mean yield of 3.38 × 1010 leukocytes in the 300-ml volume. Stimulated horses yielded a mean of 6.88 × 1010 leukocytes. After leukapheresis, wbc counts decreased a mean of 38% in nonstimulated horses and decreased a mean of 30% in stimulated horses. By 6 hours after leukapheresis, circulating wbc counts of horses in both groups had returned to preleukapheresis values. The relationship between neutrophil yield and the 4 variables (preleukapheresis wbc count, preleukapheresis neutrophil count, preleukapheresis lymphocyte count, and the pcv of the leukocyterich plasma) were examined, using simple (pairwise) correlation and multiple linear regression. A significant positive correlation was found between neutrophil yield and preleukapheresis wbc and neutrophil counts.

Because sodium citrate was used in the collection system to prevent extracorporeal blood coagulation, ionized and total serum calcium concentrations were monitored before and after leukapheresis. Although total serum calcium concentrations remained unchanged, ionized calcium concentrations decreased approximately 33% from base-line values during the 2-hour leukapheresis procedures. Occasional mild muscle fasciculations were the only adverse clinical signs of citrate toxicity exhibited by the horses. Blood ionized calcium levels returned to base-line values by 6 hours after leukapheresis.

A third group of 5 nonmedicated horses was used to evaluate the wbc and platelet yields, using a blood cell separator set at 2,000 rpm. The 300-ml volumes of platelet-rich plasma contained a mean of 8.02 × 1011 platelets and had a mean of 2.51 × 1010 wbc as contaminants.
Experimental bluetongue virus infection of sheep; effect of previous vaccination: Clinical and immunologic studies
Authors: Mahrt Charles R. , Osburn Bennie I.
Published: February 2025

Clinical and immunologic responses of sheep to vaccination and subsequent bluetongue virus (btv) challenge exposure were studied and compared with those of non-vaccinated sheep. Sheep were vaccinated with inactivated btv administered with aluminum hydroxide and cimetidine or levamisole. After sheep were vaccinated, precipitating group-specific antibodies to btv were detected, but serotype-specific neutralizing antibodies were not detected. Cellular immune responses (lymphocyte blastogenesis) to btv were not detected.

After virulent btv challenge exposure, vaccinated and nonvaccinated sheep developed acute clinical disease of similar severity. Clinical signs included hyperemia and petechiae of oral mucosa and coronary bands of the feet, excess salivation, nasal discharge with crusting, ulceration of the muzzle, and edema of lips and intermandibular space. Marked increases in serum creatine kinase activity were associated with stiff gait, reluctance to move, and vomiting. Fever and leukopenia were detected in most of the challenge-exposed sheep. Viremia and neutralizing antibodies were detected in vaccinated and nonvaccinated sheep after challenge exposure. Bluetongue virus-specific reaginic antibodies were not detected in sera from any of the sheep when the passive cutaneous anaphylaxis test was used.
Experimental bluetongue virus infection of sheep; effect of vaccination: Pathologic, immunofluorescent, and ultrastructural studies
Authors: Mahrt Charles R. , Osburn Bennie I.
Published: February 2025

Ten sheep were inoculated with bluetongue virus (btv) serotype 17. Six of the sheep had been vaccinated before challenge exposure, 4 sheep served as nonvaccinated challenge-exposed controls, and 2 additional sheep served as nonvaccinated, nonchallenge-exposed, contact controls. Biopsy specimens (oral labial mucosa and skin) were obtained periodically after challenge exposure. Sheep were killed 8 to 13 days after challenge exposure, and necropsy was done.

Vaccination did not seem to affect the nature or severity of the lesions observed. The changes in the mucosa of the cranial portion of the digestive tract included hyperemia, edema, inflammation, petechiae, erosions, ulcers, and surface encrustations. Lesions of skeletal, cardiac, and smooth muscles included hemorrhage, edema, myofiber degeneration, and necrosis. Lesions in cardiac muscles were sometimes widespread, indicating that cardiac failure may have been the major contributor to pulmonary congestion, edema, and eventual death during acute btv infection. Damage to esophageal musculature resulted in vomiting. Hemorrhage was observed within the base of the pulmonary artery of all challenge-exposed sheep.

Using immunofluorescence, bluetongue viral antigens were detected in small blood vessels of the skin, oral labial mucosa, tongue, esophagus, rumen, reticulum, urinary bladder, and pulmonary artery and in skeletal and cardiac muscles. Viral antigens were present in tissues obtained 3 to 11 days after inoculation.

Ultrastructurally, changes in small-caliber blood vessels included congestion, hemorrhage, swollen degenerated endothelial cells, and occasional fibrin-platelet thrombi. Tubular structures and virus-like particles were observed within some of these endothelial cells.

Immunofluorescent, microscopic, and ultrastructural observations support the theory that btv-induced damage to endothelial cells could account for the lesions of hyperemia, hemorrhage, inflammation, edema, and secondary ischemic necrosis of tissues.
Mycoplasma bovoculi infection increases ocular colonization by Moraxella ovis in calves
Authors: Rosenbusch R. F. , Ostle A. G.
Published: February 2025

To determine whether infection with Mycoplasma bovoculi increases ocular colonization of cattle eyes with Moraxella bovis and other bacteria, colonization of ocular gram-negative bacteria were measured in eyes of cattle infected with Mycoplasma bovoculi. Strains of Moraxella ovis were chosen because these are among the most commonly isolated species of gram-negative bacteria from cattle eyes. Five strains of M ovis were characterized biochemically and by pilus structure, permitting the recognition of 2 biotypes. All strains were tested in a mouse corneal pathogenicity model. One strain of each biotype was selected for testing in calves. All 5 strains were apathogenic for mice, and the 2 strains tested in cattle did not induce keratitis. Infection of calves with Mycoplasma bovoculi increased the amount and persistence of colonization with the strains of M ovis.
Q fever vaccination of sheep: Challenge of immunity in ewes
Authors: Brooks D. L. , Ermel R. W. , Franti C. E. , Ruppanner R. , Behymer D. E. , Williams J. C. , Stephenson J. C.
Published: February 2025

Adult ewes (17 months of age) were vaccinated against Coxiella burnetii, using a formalin-inactivated whole cell (wc) phase I Henzerling strain vaccine or a chloroform methanol residue (cmr) vaccine. Nineteen pregnant ewes were placed in 3 categories [(i) unvaccinated, (ii) wc vaccine, and (iii) cmr vaccine] and were challenge exposed at approximately the 100th day of gestation with 210,000 plaque-forming units of C burnetii inoculated subcutaneously.

Sheading of rickettsiae was measurably reduced, but was not prevented in vaccinated groups, as shown by inoculating ewes’ placental tissues, amniotic fluid, and colostrum into mice, as well as by histopathologic lesions of placental tissues. The rickettsiae were shed in the placenta, amniotic fluid, or colostrum in 6 nonvaccinated ewes. In comparison, rickettsiae were detected in placental inoculations from 2 of 6 ewes in the wc vaccine group and 1 of 6 in the cmr group. In contrast to those in the vaccinated ewes, placentitis, high concentrations of rickettsiae in microscopic preparations, and weak lambs were typical for the nonvaccinated ewes.
Immune response in sows given transmissible gastroenteritis virus or canine coronavirus
Authors: Woods Roger D. , Wesley Ronald D.
Published: February 2025

Twelve pregnant sows were inoculated oral-nasally 8 weeks before farrowing with attenuated transmissible gastroenteritis virus (tgev), tissue culture-adapted canine coronavirus (ccv), or fluids from mock-infected culture (controls). A 2nd dose of the same inoculum, one-half oral-nasally and one-half intramammarily, was given 6 weeks later. Neutralizing antibodies for tgev and ccv were demonstrated in sera, colostrum, and milk whey from the virus-vaccinated sows. Homologous geometric mean neutralizing titers were generally 4-fold higher than were heterologous titers. After challenge exposure of the nursing pigs with virulent tgev, average morbidity and mortality for the pigs were 81% and 34% (mortality range = 11% to 63%), respectively, in the tgev-vaccinated group; 83% and 39% (mortality range = 15% to 83%), respectively, in the ccv-vaccinated group; and 97% and 84% (mortality range = 78% to 100%), respectively, in the controls. Seemingly, sera from swine exposed to ccv could test serologically positive for tgev-neutralizing antibody, and tgev and ccv share at least 1 common neutralizing determinant that may be involved in protection.
Inhibition of African swine fever infection in the presence of immune sera in vivo and in vitro
Authors: Gonzalvo F. Ruiz , Carnero M. E. , Caballero C. , Martinez J.
Published: February 2025

In assay cultures, sera from African swine fever convalescent pigs inhibited infection by homologous African swine fever virus. The infection-inhibition capacity did not correspond with the virus-neutralizing capacity. The serum did not prevent infection by heterologous virulent viruses.

Sera from pigs challenge inoculated with the homologous virulent virus and later with a heterologous virulent virus inhibited the infection by different heterologous virulent viruses. These sera did not interfere with the infection by pseudorabies virus. The specificity of the reaction indicated that the infection inhibition was caused by antibody.
Fluorescent antibody technique to detect Cowdria ruminantium in in vitro-cultured macrophages and buffy coats from cattle, sheep, and goats
Authors: Sahu Sudhir P.
Published: February 2025

Fluorescent antibody tests, Giemsa stain, and electron microscopy were used to detect colonies of Cowdria ruminantium in in vitro-cultured macrophages and buffy coats from heartwater-infected cattle, sheep, and goats. Antibodies were obtained from C ruminantium-infected cattle, sheep, and goats treated with a small dose of oxytetracycline HCl. Cowdria ruminantium elementary bodies were small-coccus forms (0.14 μm) and large-coccus forms (0.22 μm to 0.6 μm). The size of inclusion bodies varied from 1.5 μm to 2 μm. Inclusion bodies and elementary bodies were observed in the cytoplasm of macrophages and neutrophils.
Effects of exposure to ambient air on articular cartilage of rabbits
Authors: Bauer Michael S. , Woodard J. Carroll , Weigel Joseph P.
Published: February 2025

Effects of exposure to ambient air (20 to 22 C) on articular cartilage from rabbits were evaluated. Bilateral arthrotomies were performed on the stifles of 18 New Zealand White rabbits. The cranial surface of the left distal femur, including the articular cartilage of the trochlea, was exposed to air for 2 hours. The right stifle was opened and closed immediately. Six rabbits were killed at the end of the surgical operation (group 1), 6 after 2 weeks (group 2), and 6 after 4 weeks (group 3), and femurs were harvested.

A distinct color change was seen in the exposed cartilage in group 1; however, minimal change was detected in group 2, and no change was seen in group 3. Proteoglycan content did not differ between the exposed and control cartilage in any group. The number of viable cells and empty lacunae in articular cartilage did not differ between the exposed and control femurs. Total cell counts and degenerative cell counts were similar, comparing the left and right trochlea in groups 1 and 3. A significant increase in cellularity was noticed in the radial zone of the exposed cartilage in group 2 (P < 0.01). In the same group, a significantly increased number of degenerative cells were seen in the tangential zone of the exposed cartilage (P < 0.05). Changes in cellularity were consistent with cartilage damage. Seemingly, exposing articular cartilage to air for 2 hours causes reversible cartilage damage.
Immunofluorescent evaluation of the lower respiratory tract of healthy horses and of horses with chronic bronchiolitis
Authors: Winder N. Christine , von Fellenberg Roland
Published: February 2025

Pulmonary parenchymal tissues from 6 healthy horses and from 9 horses with chronic bronchiolitis were evaluated by use of an indirect immunofluorescent technique. In horses of both groups, the diffuse interstitial immunofluorescence was most intense for immunoglobulin (Ig)G, moderate for IgA, and minimal for IgM. Intensity of fluorescence was increased markedly in diseased lungs exposed to anti-IgA and anti-IgG. Around small bronchi and large bronchioles of healthy horses, IgA-containing cells generally were more numerous than were IgG-Fc fragment (Fc)-containing cells; in small bronchioles, however, IgA-containing cells and IgG (Fc)-containing cells were identified with approximately equal frequency. Immunoglobulin-containing cell types usually were located in the lamina propria and submucosa of airways, with occasional Ig-containing cells seen interepithelially and intraluminally; IgG (T)- and IgM-containing plasma cells were observed infrequently in the same regions. The number of Ig-containing cells became fewer as the diameter of the airway decreased; therefore, at the level of the terminal bronchiole, Ig-containing cells only were observed occasionally. This pattern of Ig-containing cell distribution was similar in horses with chronic bronchiolitis; however, horses with chronic bronchiolitis had more IgA-containing cells forming perivascular and peribronchiolar cuffs than did healthy horses. The number of IgG (Fc)-containing lymphocytes and non-Ig-stainable lymphocytes also were higher in horses with chronic bronchiolitis than in healthy horses, but the number did not approach the magnitude of that observed for IgA-containing cells. One horse had deposits of complement C3 and IgG (Fc) within alveolar septa.
Bone remodeling in the lumbar vertebrae of young adult Beagles
Authors: Snow Gillian R. , Karambolova Kristi K. , Anderson Colin
Published: February 2025

Thirty-two static and dynamic histomorphometric determinants of tetracycline-labeled trabecular bone were determined for the L1 and L3 vertebrae of 5 intact and 6 oophorectomized Beagle bitches. Because significant differences in trabecular bone remodeling between the 2 vertebrae were not found, we concluded that the mean of the combined L1 and L3 data, or the mean of data generated from individual vertebrae, may be representative of trabecular bone remodeling of the lumbar vertebrae of Beagles.
Injury versus inflammatory response in the lungs of rats intratracheally inoculated with bacterial lipopolysaccharide
Authors: Lopez Alfonso , Yong Shirley
Published: February 2025

The relationship between acute pulmonary cell injury and inflammatory response was investigated in rats killed 1, 3, and 7 days after intratracheal inoculation with bacterial lipopolysaccharide (lps). Activities of lactate dehydrogenase (ldh) and alkaline phosphatase (ap) in bronchoalveolar lavage (bal) fluid and bronchoalveolar cell (bac) lysate supernatants were used as indicators of cell injury in the lung. Concentrations of protein in bal fluid and the number and types of bac were used as indicators of pulmonary inflammatory response. The magnitude of inflammation and cell injury was calculated as the percentage difference of cellular and biochemical values, compared with values of nontreated controls. Inoculation with lps induced a significant and dramatic (> 18,000%) influx of polymorphonuclear leukocytes (pmn) and a mild (approx 250%) increase in pulmonary alveolar macrophages. A moderate, significant and time-dependent increase in ldh (up to approx 260%) and ap (up to approx 220%) was detected in bal fluid and bac lysate supernatants after lps inoculations. Inoculation with saline solution alone resulted in increased pmn (approx 975%), but did not alter ldh and ap values. In all rats evaluated, protein concentrations did not change. Numbers of pmn significantly and positively correlated with activities of ldh and ap. Protein concentrations and pmn counts had a negative nonsignificant association. Evidence of further cell injury was not detected after massive influx of pmn into the bronchoalveolar space. Therefore, the cellular influx of pmn induced by lps probably was disproportionate to the magnitude of pulmonary cell injury.
Evaluation of a fluorometric method for the quantitative assay of fecal hemoglobin in the dog
Authors: Boulay James P. , Lipowitz Alan J. , Klausner Jeffrey S. , Ellefson Mark , Schwartz Samuel
Published: February 2025

Feces from 27 dogs were evaluated to establish baseline fecal hemoglobin (Hb) concentrations when the dogs were fed diets containing varying amounts of Hb. Fecal Hb concentration was measured, using a quantitative fluorometric assay that was based on the conversion of nonfluorescing Hb heme to fluorescing porphyrins. Mean fecal Hb concentration was 0.31 mg/g of feces when the dogs were fed a dry diet low in Hb. This corresponded to a daily fecal blood loss of 0.043 ml/kg of body weight. The fecal Hb concentration was directly related to the dietary Hb concentration. The average recovery of orally ingested blood was 41% in 4 dogs. This fluorometric assay quantitatively detected small amounts of gastrointestinal bleeding over a wide range of fecal Hb concentrations for which feces appeared normal. Results of this study establish dietary conditions necessary for quantitative evaluation of experimental and clinical gastrointestinal bleeding.
Evaluation of renal function in cats, using quantitative urinalysis
Authors: Russo Elizabeth A. , Lees George E. , Hightower Dan
Published: February 2025

Two consecutive 24-hour quantitative urinalyses were performed on each of 12 healthy adult cats to evaluate the technique and obtain reference values for measurements of urinary excretion of several substances. Endogenous creatinine clearance (2.31 ± 0.47 ml/min/kg) and urinary protein excretion (17.43 ± 9.05 mg/kg/day) were determined. Additionally, clearances and ratios to creatinine clearances were calculated for phosphate, sodium, potassium, and chloride. The endogenous creatinine clearance value was compared with another estimate of glomerular filtration rate that was based on 99mTc(Sn) diethylene-triaminepentaacetic acid clearance (2.52 ± 0.58 ml/min/kg). Evaluation of feline renal function, using 24-hour quantitative urinalysis techniques, has potential for clinical application, but has several important limitations as well.
Systemic pathologic responses in experimental Psoroptes ovis infestation of Hereford calves
Authors: Stromberg Paul C. , Fisher William F. , Guillot Frank S. , Pruett John H. , Price Roger E. , Green Robert A.
Published: February 2025

Nine Hereford calves were infested with Psoroptes ovis and were allowed to develop clinical mange during a 9-week period. Blood, serum, and urine samples were obtained before and after calves were infested and were compared with those from 3 noninfested control calves. All calves were euthanatized and necropsied 9 weeks after they were infested. Gross and microscopic anatomic changes occurred only in the skin. Calves developed typical exudative dermatitis, the extent of which was dependent on population density of mites. Severely infested calves (50% to 70% of skin with dermatitis) developed a mild anemia and lymphopenia with marked neutropenia and variable eosinophilia. There were also increases in fibrinogen, γ-globulin, and in vitro lymphocyte response to mitogen stimulation and decreases in anion gap cortisol, albumin, albumin/globulin ratio, and fractional Na clearance values. The severity of many of the changes could be correlated with the extent of dermatitis.
24-Hour renal clearance and excretion of endogenous substances in the mare
Authors: Kohn Catherine W. , Strasser Sheryl L.
Published: February 2025

Urine samples were obtained from, 6 healthy mares. During a 2-day acclimation period, mares were kept in stalls, fed sweet feed and mixed grass hay, and allowed free access to water and trace mineral salt. The mares were crosstied in their stalls within reach of hay, salt, and water for 24 hours during which urine was obtained by constant flow via indwelling Foley catheters.

Twenty-four-hour urine production was 7,649 to 11,904 ml/day (X = 9,212 ± 1,928) or 14.7 to 25.1 ml/kg/day. (X = 19.3 ± 4.1). Urinary excretion and clearance of electrolytes and protein were determined from aliquots of well-mixed, pooled 24-hour urine samples. These values were sodium (Na) = 0 to 1.7 mEq/kg/day (X = 0.4 ± 0.7), chloride (Cl) = 2.0 to 4.2 mEq/kg/day (X = 3.0 ± 0.8), phosphorous (P) = 0.03 to 0.12 mg/kg/day (X = 0.07 ± 0.03), potassium (K) = 3.7 to 6.5 mEq/kg/day (X = 5.3 ± 1.4), and creatinine (Cr) = 32.1 to 53.9 mg/kg/day (X = 40.3 ± 8.5). Fractional excretions of electrolytes were Na = 0% to 0.46% (X = 0.1 ± 0.2), Cl = 0.48% to 1.64% (X = 1.14 ± 0.45), Ρ = 0.04% to 0.16% (X = 0.08 ± 0.04), and Κ = 23.9% to 75.1% (X = 51.7 ± 17.3). Average clearances (ml/hr/kg) were Na = 0.12 ± 0.19, Κ = 64.1 ± 17.1, Cl = 1.21 ± 0.33, and Ρ = 0.09 ± 0.51. Average endogenous Cr clearance (ml/min/kg) was 1.92 ± 0.51. Twenty-four-hour urinary protein excretion was 1,747 to 9,944 mg/day (X = 5,619 ± 3,024) or 3.6 to 22.3 mg/kg/day (X = 12.0 ± 7.0). There was no growth on urine cultures from 4 mares, small numbers of α-streptococci in 1 mare, and Esherichia coli (> 30,000 colony-forming units/ml) in 1 mare.

The present study established base lines for urinary excretions of Cl, P, Cr, and protein in adult horses, based on 24-hour collections. Fractional excretions of Na, K, Cl, and Ρ calculated from these data validated the acceptable ranges for fractional excretions of Na, Cl, and Ρ established by previous investigators who determined fractional excretion based on 7- to 10-hour urine collections. The upper end of the range for fractional excretion of Κ exceeded the previously recorded value, probably because horses in the present study were given free access to salt and hay.