bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of neutrophil adhesion molecules and shedding of Staphylococcus aureus in milk of cortisol- and dexamethasone-treated cows
Authors: Burton Jeanne L. , Kehrli Marcus E. 
Published: January 2024

SUMMARY
The effects of 3 days of glucocorticoid administration on bovine blood neutrophil expression of l-selectin and CD18, and on the health status of mammary glands subclinically infected with Staphylococcus aureus were measured in 9 lactating Holsteins. The experiment was a 3 x 3 Latin square cross-over design, with 3 glucocorticoid treatments switched among groups of 3 cows/treatment during 3 periods. Treatments consisted of a vehicle (control, 10 ml of excipient/cow/d), cortisol (7.5,15, and 7.5 mg/cow on days 1, 2, and 3, respectively), and dexamethasone (0.04 mg/kg of body weight/cow/d for total daily dosages that ranged from 21.6 to 33.2 mg). Blood samples for immunostaining and flow cytometric analysis of l-selectin and CD18 and leukograms, as well as foremilk samples for determination of S aureus shedding, somatic cell counts, protein and fat percentages, and daily milk yields were collected repeatedly before, during, and after treatment days. Dexamethasone caused a profound, acute, short-lived down-regulation of l-selectin on neutrophils, which correlated in time to leukocytosis, mature and immature neutrophilias, increased shedding of S aureus in infected glands, and onset of high percentages of fat and protein and decreased milk yields. Dexamethasone also caused profound but delayed down-regulation of neutrophil CD18, which reached nadir simultaneously with reappearance of l-selectin-bearing neutrophils, normalized blood neutrophil counts, markedly high foremilk somatic cell counts and protein percentage, decreased S aureus shedding in milk, and finally, expression of clinical mastitis in some infected quarters. Each of these variables had returned to control (vehicle) values by the ninth (and last) sample collection day. Although cortisol treatment also decreased expression of l-selectin and CD18 on neutrophils, dosages used in this study were not sufficient to alter the number of circulating cells or to convert subclinical mammary gland infections to clinical mastitis. These results suggest that mammary gland health status can be altered by sudden exposure of blood neutrophils to glucocorticoids, because these steroid hormones caused profound down-regulation of the adhesion molecules that direct neutrophil margination and migration through the vascular endothelium. The results also reinforce the potential disease risk of treating infected animals with potent synthetic glucocorticoids, such as dexamethasone.
Study of transneuronal passage of pseudorabies virus in rat central nervous system by use of immunohistochemistry and in situ hybridization
Authors: Sur J. H. , Kim S. B. , Osorio F. A. , Moon O. K. 
Published: January 2024

SUMMARY
We studied the uptake and sequential transneuronal passage of pseudorabies virus (prv) in rat cns by use of a combination of immunohistochemistry and in situ hybridization. Protocols for rapid detection of prv by immunohistochemistry and in situ hybridization in rats with prv infection of the cns after intranasal instillation of a wild-type strain of prv were optimized in vitro, using porcine kidney-15 cells.
Pseudorabies virus-specific hybridization signals appeared in the cytoplasm and nucleus of prv-infected porcine kidney-15 cells by postinoculation (pi) hour 6. In tissue sections of prv-infected rats, prv nucleic acids were detected in areas of the rat brain in close proximity to the areas in which prv antigens were evident. The prv was initially found in the nucleus of trigeminal ganglion neurons at pi hour 24. At pi hour 72, prv antigens were observed in the mid-brain, and 24 hours later, in the telencephalon. We also found evidence of specific progressive transsynaptic transmission of the virus, and, on the basis of that, we have constructed a map of the synaptic contacts and pathways in the brain.
Therefore, combined use of immunohistochemistry and in situ hybridization was useful for characterizing the pathogenesis of prv in the cns of rats after intranasal inoculation, following a pattern that mimics prv infection of the natural host.
Effect of phenylbutazone and flunixin meglumine on acute toxic mastitis in dairy cows
Authors: Dascanio J. J. , Mechor G. D. , Gröhn Y. T. , Kenney D. G. , Booker C. A. , Thompson P. , Chiffelle C. L. , Musser J. M. M. , Warnick L. D. 
Published: January 2024

SUMMARY
A double-blinded randomized prospective clinical trial was designed to evaluate the effectiveness of flunixin meglumine and phenylbutazone for treatment of acute toxic mastitis in dairy cows. All cows were treated 4 times at 12-hour intervals by intramammary infusion of gentamicin (150 mg). A total of 45 dairy cows with toxic mastitis were randomly assigned to 1 of 3 treatment groups: group 1 (control), saline solution, iv; group 2,1 g of flunixin meglumine, iv; or group 3, 4 g of phenylbutazone, iv. Physical examination and udder variables were assessed at initial examination and 24 hours later. Milk production was recorded at regular intervals from 1 week before until 10 weeks after development of mastitis.
Rear quarters (34/45) were more commonly affected than front quarters. Thirty-five cows returned to the herd, 9 cows were culled, and 1 cow died. There were no significant differences among treatment groups in the need for further treatment or outcome. Klebsiella spp (18/45) and Escherichia coli (16/45) were the most common pathogens isolated by culture of milk from affected quarters. The overall bacteriologic cure rate on days 7 and 14 was 64 and 75%, respectively.
At the time of initial examination, cows of the control group had higher rectal temperature than did cows of the flunixin group. At the examination 24 hours later, the rectal temperature of cows in all treatment groups was lower than the temperature at initial examination; at that time (24 hours), however, there were no significant differences in temperature among the treatment groups.
Adjusted for stage of lactation, calving season, and parity, mastitic cows, compared with nonmastitic cows from the same herd, had lower milk production in the 10 weeks after development of mastitis, particularly during the week of onset. In repeated measures models, the loss of milk associated with mastitis was not significantly different among the 3 treatment groups.
Sustained release of liposome-encapsulated enrofloxacin after intramuscular administration in rabbits
Authors: Cabanes Ana , Reig Francesca , Antón José M. Garcia , Arboix Margarida 
Published: January 2024

SUMMARY
Enrofloxacin was encapsulated in multilamellar liposomes composed of phosphatidylcholine and cholesterol (molar ratio, 1:1), and its potential use as sustained release formulation was evaluated. The encapsulated drug was administered im to rabbits (n = 6). Results indicated that absorption rate was slow, compared with previous studies; additionally, peak concentration was lower (0.5 ± 0.1 µg/ml), and the time to peak concentration was considerably longer for liposome-encapsulated enrofloxacin (1.5 ± 1.08 hours) than for unencapsulated drug. Apparent elimination half-life of drug in the body was significantly (P < 0.05) increased (4.05 ± 1.08 hours) when it was administered encapsulated in liposomes. Large-size liposomes containing enrofloxacin administered im to rabbits gave sustained drug release from the injection site, providing therapeutic and prolonged plasma concentrations of drug in the body.
Responses of blood and plasma lactate and plasma purine concentrations to maximal exercise and their relation to performance in Standardbred trotters
Authors: Räsänen Leena A. , Lampinen Kimmo J. , Pösö A. Reeta 
Published: January 2024

Abstract

Objective
To study whether end products of 2 pathways of anaerobic energy metabolism, lactate and purines, that accumulate in the blood after intense exercise indicate any relation to exercise performance.

Design
Venous blood samples were taken within 1 and 15 minutes after a trotting race of 2,100 m.

Animale
16 Clinically healthy Standardbred trotters.

Procedure
Blood and plasma lactate concentrations were measured by enzymatic analyzer, and purines, uric acid and allantoin, were determined by high-performance liquid chromatography. The concentrations of metabolites were then correlated to racing time and individual performance indexes that are annually calculated from the percentage of winnings, placings, and starts rejected, average earnings per start, and the racing record.

Results
Blood lactate concentration immediately and calculated cell lactate concentration immediately and 15 minutes after the race correlated positively (P < 0.05 to P < 0.01) with the individual performance indexes. Plasma lactate concentration was not correlated to the individual performance indexes. Uric acid concentration, immediately and 15 minutes after the race, was negatively correlated (P < 0.05) to the individual performance indexes, and a positive relation (P < 0.05) was found between the highest concentration of uric acid and the racing time. Concentration of allantoin immediately or 15 minutes after the race did not have any significant correlation to the individual performance indexes.

Conclusions
Accumulation of lactate in the blood, which was greater in the superior performing horses, may prove to be an useful predictor of anaerobic capacity. The results also indicate that the loss of purine nucleotides was less in the superior performing horses, although further studies are needed to confirm this.
Effects of aging on the endodontic system, reserve crown, and roots of equine mandibular cheek teeth
Authors: Kirkland Khristina D. , Baker Gordon J. , Marretta Sandra Manfra , Eurell Jo Ann C. , Losonsky John M. 
Published: January 2024

Abstract

Objective
To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth.

Design
Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations.

Sample Population
48 right hemi-mandibles from horses 2 to 9 years old.

Procedure
Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types.

Results
Permanent mandibular cheek teeth of the horse, at the time of eruption, consisted of an exposed crown and a reserve crown with a widely dilated apex. The endodontic system consisted of 5 or 6 pulp horns that connected to an expansive pulp in the reserve crown, which was confluent with the primordial pulp bulb surrounding the tooth’s apex.
At the time of eruption, mandibular cheek teeth did not have a distinct pulp chamber, roots, or evidence of root formation. However, within 2 years after eruption, mesial and distal roots and a pulp chamber were present. A distinct pulp chamber, communicating with the pulp horns and both root pulp canals, was identifiable for 4 to 5 years from the time of root formation. The endodontic system of cheek teeth, 6 to 8 years after eruption, consisted of 2 unattached compartments, made up of a root canal, pulp chamber, and 2 or 3 pulp horns.

Clinical Relevance
The age-related morphologic changes in equine mandibular cheek teeth have important implications for application of endodontic therapy in horses. (Am J Vet Res 1996;57:31-38)
Reliability of a single fecal egg per gram determination as a measure of individual and herd values for trichostrongyle nematodes of cattle
Authors: Gasbarre Louis C. , Leighton Eldin A. , Bryant Dean 
Published: January 2024

Abstract

Objectives
To determine precision of a single fecal egg count, to evaluate the necessity of repeated testing to ascertain the number of parasite eggs found per gram of fecal material (EPG) of a given animal, and to infer the number of cattle that must be sampled to estimate the mean EPG value of a given herd.

Design
Calves born in 4 successive years were tested for 3 consecutive days in May, July, and September to determine their fecal EPG value. Results were analyzed to determine important sources of variance in the EPG values.

Animals
427 Black Angus calves.

Procedures
Nematode EPG values were determined by zinc sulfate flotation of fecal samples taken from the rectum. Variance components were estimated by restricted maximal likelihood procedures.

Results
The largest source of variation in fecal egg counts arose from differences among calves. Variation associated with sampling within calf was larger than that associated with year of sampling or day when samples were taken. Repeatability of EPG determinations was between 0.4 and 0.7.

Conclusions
Collection of 3 replicate samples reduced variance associated with a single calf mean by 25 to 30%. Additional replication would further reduce the variance, but at a diminishing rate. To accurately estimate mean EPG for a herd, a randomly drawn sample should be similar in composition to the herd and include at least 1 animal from the high EPG group, which often constitutes 15 to 20% of the calves. To ensure that, on average, 95% of the samples drawn contain 1 or more animals with high EPG, the sample must include 15 to 20 animals within the grazing group under study.
Study of hereditary cerebellar degeneration in cats
Authors: Inada Shichiro , Mochizuki Masami , Izumo Shuji , Kuriyama Masaru , Sakamoto Hiroshi , Kawasaki Yasuaki , Osame Mitsuhiro 
Published: January 2024

Abstract

Objective
To elucidate the nature of ataxia observed in 3 cats spanning 2 generations.

Design
Experimental breeding was attempted to confirm heritability of the disease and establish the mode of inheritance; the original 3 cats and their offspring were studied.

Animals
Seven diseased cats spanning 3 generations and 11 neurologically normal cats.

Procedure
Cats were examined by use of the following methods: clinical observation, hematologic and serum biochemical examinations, neurologic examination, electrodiagnostics, magnetic resonance imaging, lysosomal enzyme activity assay, horizontal transmission test, and virologic and pathologic examinations.

Results
All kittens (1 male and 3 females) obtained by backcrosses developed pure cerebellar dysfunction from the age of 7 to 8 weeks onward. It became progressively worse, but not fatal, between 1 and 2.5 months. Prenatal or perinatal infection with feline panleukopenia virus, inherited lysosomal storage diseases, including gangliosidosis and mannosidosis, and feline hereditary neuroaxonal dystrophy were excluded. Magnetic resonance imaging indicated that size of the cerebellum of diseased cats was markedly reduced. Cerebellar cortical degeneration, especially with extensive destruction of Purkinje cells, was observed microscopically.

Conclusion
The disease was concluded to be cerebellar degeneration of a new clinical form in cats having an autosomal recessive mode of inheritance.

Clinical Relevance
When cerebellar dysfunction is diagnosed in a cat, hereditary cerebellar degeneration of this type should be considered in the differential diagnosis.(Am J Vet Res 1996; 57: 296-301)
Role of milk fractions, serum, and divalent cations in protection of mammary epithelial cells of cows against damage by Staphylococcus aureus toxins
Authors: Cifrian Eduardo , Guidry Albert J. , Marquardt Warren W. 
Published: January 2024

Abstract

Objective
To determine the effect of milk and blood serum constituents on cytotoxicity of Staphylococcus aureus on mammary epithelial cells.

Design
In vitro incubation of cells with cytotoxic agents and milk and serum constituents.

Sample Population
Mammary cells, milk, and blood obtained from 3 cows.

Procedure
Staphylococcal α-toxin and culture supernatants from S aureus M60 and an α-toxin-negative mutant of M60 were incubated with bovine mammary epithelial cells in the presence of milk fractions, serum, and divalent cations. Propidium iodide fluorescence was used as a measure of cell damage.

Results
Skim milk and milk whey inhibited S aureus cytotoxic agents. Skim milk protected against α-toxin damage to a greater extent than milk whey. Serum from an adult animal was more protective than was fetal serum. Milk fat and serum albumin had no protective effect. Divalent calcium and Mg2+ were more effective inhibitors of mammary epithelial cell damage caused by α-toxin than of damage attributable to M60 culture supernatant. Divalent calcium and Mg2+ at concentrations similar to those of free Ca2+ and Mg2+ in normal bovine milk decreased cytotoxic damage attributable to α-toxin. However, concentrations similar to those of total Ca2+ and Mg2+ in normal milk were required to decrease cell damage caused by M60 culture supernatant. The α-toxin-negative mutant was less cytotoxic than the M60 parent strain.

Conclusions
Casein, as well as Ca2+ and Mg2+ in bovine milk, inhibit the cytotoxic effect of S aureus on mammary epithelial cells.(Am J Vet Res 1996;57:308-312)
Effects of hematocrit and erythrocyte deformability on pulmonary vascular pressures in perfused pony lungs
Authors: Weiss Douglas J. , Richwagen Kristin , Evanson Oral A. 
Published: January 2024

Abstract

Objective
To evaluate the contribution of hematocrit and RBC deformability to pulmonary vascular pressures of racehorses.

Design
Pony lungs were isolated and right and left lungs were perfused separately with blood. The effects of changing hematocrit and of pentoxifylline treatment were evaluated.

Animals
11 healthy mixed-breed ponies.

Procedure
Ponies were anesthesized, blood was collected, and lungs were removed and perfused with blood at constant flow rate.

Results
Increasing the hematocrit from 35% to 65% resulted in increases in pulmonary arterial pressure (53%, 45%), capillary shear stress (45%, 32%), and total vascular resistance (92%, 143%) at low (352 ± 33 ml/min) and high (1,442 ± 48 ml/min) flow rates, respectively. Pulmonary artery pressures were lower (10%, 11%) when lungs were perfused with blood from pentoxifylline-treated ponies, compared with blood from control ponies with low hematocrit (PCV, 30%) and low-flow rate and with high hematocrit (PCV, 45%) and high flow rate, respectively. Decreases in capillary shear stress and total vascular resistance were also observed for pentoxifylline-treated blood.

Conclusions
Increases in hematocrit equivalent to those occurring during competitive racing activity contribute substantially to pulmonary vascular pressures in horse lungs. Administration of pentoxifylline to ponies reduced RBC deformability and attenuated increases in pulmonary vascular pressures.

Clinical Relevance
Treatment of racehorses with pentoxifylline may reduce exercise-associated increases in pulmonary vacular pressure, thereby attenuating exercise-induced pulmonary hemorrhage.(Am J Vet Res 1996;57:346-350)
Cytokine release by porcine livers perfused with lipopolysaccharide or live Salmonella choleraesuis
Authors: Frank Dagmar E. , Ahrens Franklin A. , Kramer Ted T. 
Published: January 2024

Abstract

Objective
To develop a model to study the kinetics and relative amounts of cytokines produced by liver cells during enteric infection.

Design
Salmonella enteriditis lipopolysaccharide (LPS)-or live S choleraesuis-stimulated isolated livers from clinically normal pigs and pigs with active acute phase response.

Animals
7- to 14-day-old salmonellosis-free pigs, 4 to 12/group.

Procedure
Livers were removed and perfused with oxygenated Krebs-Henseleit solution for 30 minutes and with S choleraesuis or LPS added for 7 minutes. Livers were then perfused with 500 ml of fresh solution in a closed loop procedure for 180 minutes. Perfusate samples were collected for tumor necrosis factor-α (TNFα) and interleukin 6 (IL-6) bioassays.

Results
Tumor necrosis factor-α values remained constant during perfusion of normal livers and increased in those exposed to LPS. Interleukin 6 values increased in perfusate from normal livers from 30 to 150 minutes, then decreased. In livers from pigs with an active acute phase response, TNFα values were reduced; IL-6 appeared by 2 minutes and decreased after 25 minutes.

Conclusions
Isolated livers could be kept viable for 3 hours, and IL-6 and TNFα could be measured by the bioassays used.

Clinical Relevance
Model can be used for studying and modifying the response of liver cells to infective agents. (Am J Vet Res 1996;57:472–476)
Hybridization of 2,659 Clostridium perfringens isolates with gene probes for seven toxins (α, β, ε, ι, θ, μ, and enterotoxin) and for sialidase
Authors: Daube Georges , Simon Patricia , Limbourg Bernard , Manteca Christophe , Mainil Jacques , Kaeckenbeeck Albert 
Published: January 2024

Abstract

Objective
To genetically characterize Clostridium perfringens isolates for association of pathologic type with various diseases.

Design
Prospective study.

Sample Population
2,659 C perfringens isolates from various nonhuman animals species, human beings, and foods.

Procedure
Colony hybridization with DNA probes for 7 toxin (α, β, ε, ι (subunits a and b), θ, μ, and enterotoxin) genes and 1 sialidase gene were performed to group the isolates by pathologic type.

Results
Enterotoxin-negative type-A isolates were the most common (2,575/2,659), were isolated from all sources, and were separated into 5 pathologic types. In cattle and horses with enterotoxemia, essentially only these pathologic types were identified. The enterotoxin-negative isolates of types C or D each had a single pathologic type. Type-C isolates were isolated only from swine with necrotic enteritis and type-D isolates from small ruminants with enterotoxemia, except that 1 type-D isolate was also found from a healthy fish. Type-B or -E isolates were not found. Among the 47 enterotoxin-positive isolates, 5 isolates from sheep or deer were type D and the other 42 were type A. These 42 isolates were grouped into 3 pathologic types: 1 type was isolated from samples of almost all origins, but the other 2 types were found in only 5 fish, 4 human beings, and 1 dog.

Conclusions and Clinical Relevance
Genetic characterization of these isolates allowed identification of 11 different pathologic types. This approach may be useful in molecular diagnosis and prophylaxis of clostridial disease. (Am J Vet Res 1996;57:496–501)
Mechanisms of acid injury in porcine gastroesophageal mucosa
Authors: Argenzio Robert A. , Eisemann Joan 
Published: January 2024

Abstract

Objective
To identify the cause and mechanisms of injury in gastroesophageal ulcer disease in market weight swine.

Design
Comparison of mechanisms of injury caused by HCI with those caused by short chain fatty acids (SCFA) in gastric mucosa.

Animals
Pigs weighing 30 to 40 kg.

Procedure
Gastric tissues were studied in Ussing chambers; short-circuit current (Isc) and electrical resistance (R) were recorded in response to treatment, and tissues were examined histologically.

Results
60 mM mucosal acetate abruptly (≤ 75 minutes) and irreversibly abolished Isc at pH ≤ 4.5, whereas R decreased more slowly. These data were associated with cell swelling and vesicle formation in mid-zonal layers, followed by sloughing of the outer barrier, erosion into deeper zones, and finally, ulceration. Mucosal HCI at pH > 1.5 was ineffective; however, at pH 1.5, HCI induced an abrupt decrease in R, followed by a slow decrease in Isc, an effect opposite to that caused by SCFA. Serosal addition of HCI rapidly abolished Isc suggesting a barrier to free H+ diffusion from the mucosal solution.

Conclusions
Undissociated SCFA rapidly penetrate the outer barrier and acidify underlying viable tissue. Cellular acidification inhibits Na pumping and osmoregulation, resulting in cell swelling and necrosis. In contrast, HCI induces an increase in outer barrier permeability before accessing the transporting cells, a much longer process (≥ 5 hours) requiring a lower pH. These studies suggest that microbial production of SCFA may be important in the pathogenesis of porcine gastric ulcers. (Am J Vet Res 1996;57:564-573)