bluuebunny/crossref_metadata_2025_split huggingface dataset:
Importance of the medullary macrophage in the replication of lymphoid leukosis virus in the bursa of Fabricius of chickens
Authors: Gilka F. , Spencer J. L. 
Published: February 2025

SUMMARY
Electron microscopy and immunocytochemistry were used to study the development of lymphoid leukosis virus infection in the bursa of Fabricius of experimentally infected chicken embryos and chickens. In embryos infected at 7 days of incubation and killed 10 days later, virus particles and group-specific viral antigen were confined mainly to the connective tissue of the lamina propria of the bursal mucosal folds; a few developing follicles had discrete virions and group-specific antigen between cells. In chickens infected at 1 day of age, infection (as determined by use of electron microscopy and immunocytochemistry) was maximal in 1- to 4-month-old birds, and the greatest concentration of virus and group-specific viral antigen was in the medulla of the follicles. Although lymphoid leukosis virus was released from lymphocytes, epithelial cells, and macrophages, virus replication in the medullary macrophages was more active than that in the other cells. Normal medullary macrophages had cell membrane vesicles (50 to 80 nm in diameter) that covered part or all of the cell membrane surface. In infected chickens, virus particles frequently developed within these vesicles. Comparable vesicles were not found on cortical macrophages. Results of the present study indicated that the medullary macrophage was the principal host cell for replication of lymphoid leukosis virus in the bursa of Fabricius of the chicken.
Histopathologic changes in bovine fetuses after repeated reintroduction of a spirochete-like agent into pregnant heifers: Association with epizootic bovine abortion
Authors: Osebold John W. , Osburn Bennie I. , Spezialetti Rosanne , Bushnell Robert B. , Stott Jeffrey L. 
Published: February 2025

SUMMARY
A spirochete-like organism was found in the plasma of bovine fetuses affected with epizootic bovine abortion (eba). The spirochete-like organism was frequently found in abattoir-collected fetuses as an inapparent infection, and eba was found in cattle on foothill rangeland where the vector tick Ornithodorus coriaceus could repeatedly reintroduce the infectious agent into pregnant cattle (superinfection). Epizootic bovine abortion resembled a naturally acquired superinfection in circumstances where the agent was frequently present in the environment under conditions favoring transmission. Therefore, to determine whether fetal lesions could be experimentally induced in utero, spirochete-like organisms collected from clinically normal fetuses at an abattoir were inoculated iv and subcutaneously into 2 pregnant heifers 5 times over a 4-month period to mimic repeated tick transmission in the field. Macroscopic and microscopic examinations of tissues from 2 cesarean-collected fetuses and from 3 calves born at term with the naturally acquired spirochete infection indicated that the calves had evidence of an infection that caused morphologic changes compatible with immunologic stimulation and mild reticuloendothelial hyperplasia. Compared with findings in the calves, lesions in the superinfected fetuses were more severe, and the lesion distribution in various organs was more extensive. The spirochete-like organism appeared to be a mild pathogen because of its persistence in the host. Clinical disease from the infection may only develop with repeated superinfections. Therefore, a relationship between this microorganism and eba is probable.
Assessment of antibody response of swine infected with Mycoplasma hyopneumoniae by immunoblotting
Authors: Young Theresa F. , Ross Richard F. 
Published: February 2025

SUMMARY
An immunoblot procedure was used to evaluate porcine antibody response to inoculation with Mycoplasma hyopneumoniae. Mycoplasmas solubilized with sodium dodecyl sulfate were used as antigens. Antibodies to 5 antigens, estimated to be of molecular weight (mol wt) 110,000, 64,000, 50,000, 41,000, and 36,000, were detected in sera collected during the course of induced mycoplasmal pneumonia. Mycoplasma hyopneumoniae antigens, mol wt 110,000, 50,000, 41,000, and 36,000, cross-reacted with M flocculare when antigen prepared from M flocculare or hyperimmune serum against it were used in the immunoblot procedure. The 36,000-dalton (D) antigen reacted with M hyopneumoniae and M hyorhinis convalescent sera. The 64,000-D M hyopneumoniae antigen was the only antigen that did not cross-react with M flocculare or M hyorhinis. Exposure of immunoblot strips with antigens to trypsin before reacting them with the convalescent sera abolished binding ability of the 110,000-D and 36,000-D antigens, but had no effect on binding by 64,000-D, 50,000-D, or 41,000-D antigens. None of the 5 antigens bound to 11 lectins.
Clinical observations in Collies given ivermectin orally
Authors: Paul A. J. , Tranquilli W. J. , Seward R. L. , Todd K. S. , DiPietro J. A. 
Published: February 2025

SUMMARY
An oral liquid form of ivermectin was administered to 14 purebred Collies (12 rough coated, 2 smooth coated). All Collies were given ivermectin at dosages of 100 and then 200 μg/kg of body weight. Three of the dogs developed mild clinical signs of toxicosis (salivation, vomiting, confusion, ataxia, and tremors) with the 100 μg/kg dosage. After the 200 μg/kg dosage, 7 dogs (including 1 smooth-coated Collie) developed severe toxicosis (seizurelike activity, recumbency, nonresponsiveness, and coma). Because dogs that developed severe toxicosis were not retreated, only the 7 remaining dogs were given ivermectin at 600 μg/kg. Severe toxic signs were not observed in the dogs given the 600 μg/kg dosage, and only 1 of these 7 dogs developed severe toxicosis when given ivermectin at 2,500 μg/kg. Dogs that developed severe toxicosis were given supportive care while in the comatose state. All dogs recovered completely. The results indicated that Collies (including the smooth-coated Collies) have a wide range of sensitivity to ivermectin-induced toxicosis.
Experimental infection of lactating bovine mammary glands with Streptococcus uberis in quarters colonized by Corynebacterium bovis
Authors: Doane R. M. , Oliver S. P. , Walker R. D. , Shull E. P. 
Published: February 2025

SUMMARY
Twenty-seven quarters of 18 lactating dairy cows were inoculated intramammarily with 3.6 − 104 colony-forming units (cfu) of a strain of Streptococcus uberis isolated from a cow with clinical mastitis. Before quarters were inoculated, 22 were considered as naturally colonized with Corynebacterium bovis, and 5 were considered bacteriologically negative. Streptococcus uberis was isolated from all quarters within 2 days after inoculation, and all quarters developed clinical mastitis by 3 days after inoculation. Mastitis was acute, and most cows had increased rectal temperatures. The number of somatic cells increased significantly (P < 0.05), and milk production decreased significantly. In many cows, rectal temperatures remained increased, and Str uberis was isolated from infected glands after intramammary and systemic antimicrobial treatments were given.
A decreased number (110 cfu) of the same strain of Str uberis caused equally severe mastitis in 3 quarters colonized with C bovis and in 1 bacteriologically negative quarter in 2 cows. Streptococcus uberis was isolated from all inoculated quarters, and all quarters developed clinical mastitis by 2 days after inoculation.
Two quarters colonized with C bovis and 2 bacteriologically negative quarters were inoculated once with 25 cfu and once with 240 cfu of a different strain of Str uberis (ATCC 27958). Streptococcus uberis was never isolated from inoculated quarters, and changes in milk yield or number of somatic cells were not observed.
Second-generation pseudorabies virus vaccine with deletions in thymidine kinase and glycoprotein genes
Authors: Kit Saul , Sheppard Michael , Ichimura Hiroshi , Kit Malon 
Published: February 2025

SUMMARY
A modified-live Pseudorabies virus (prv) vaccine, designated prv(dlg92/dltk), with deletions in the thymidine kinase (tk) and glycoprotein-gIII (g92) genes, was derived from the prv (Bucharest [BUK]-dl3) vaccine strain. The vaccine virus also contained a deletion in glycoprotein gI. Despite 3 deletions, prv(dlg92/dltk) replicated to high titers in cell culture from 30 C to 39.1 C. Enzyme assays and autoradiography revealed that prv(dlg92/dltk) did not induce a functional tk activity in infected tk−RAB(BU) cells (rabbit skin).
Rabbit skin cells were infected with prv(dlg92/dltk), with vaccine strains derived from BUK or Bartha K strains of prv or with the virulent Illinois (ILL), Indiana-Funkhauser (IND-F), and Aujeszky (Auj) strains of prv and were labeled with [3H]mannose from 4 or 5 to 24 hours after infection to investigate whether these viruses induced the synthesis of glycoprotein gIII. Nonionic detergent extracts were prepared and immunoprecipitated with antisera from pigs vaccinated with tk−-prv(BUK-dl3) or tk+-Bartha K, pigs vaccinated with tk+-prv(BUK) strains and then challenge exposed to tk+-prv(IND-F), naturally infected domestic or feral pigs, and pigs vaccinated with tk−-prv(dlg92/dltk). Mouse monoclonal antibodies against prv glycoproteins gIII, gp50, and gII were also studied. After immunoprecipitation, labeled prv-specific proteins were analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis and autoradiography. The prv glyco-protein-gII complex, but not glycoprotein gIII, was synthesized in prv(dlg92/dltk)-infected cells. Glycoprotein gII and gIII were made in cells infected with prv vaccine strains BUK, Bartha K, and BUK-dl3 and with virulent prv strains ILL, IND-F, and Auj. Cells infected with prv(dlg92/dltk) and with prv strains ILL, IND-F, Auj, Bartha K, BUK, and BUK-dl3, excreted into the cell culture medium a highly sulfated glycoprotein gX of about 90 kilodaltons. Antibodies to glycoprotein gIII were not detected in the sera of pigs inoculated with prv(dlg92/dltk), but were found in all other swine sera.
Effect of prostaglandin E1 on the periosteal regional acceleratory phenomenon in fractured ribs: Histomorphometric study in Beagles
Authors: Shih Mei-Shu , Norrdin Robert W. 
Published: February 2025

SUMMARY
Transverse fractures were made surgically in the midshaft of the left 9th and 10th ribs in adult Beagles. A buffer vehicle (n = 4) or 0.2 mg of prostaglandin (pg) e1/day (n = 6) was injected into the fracture sites twice a day for 10 days, and dogs were euthanatized on day 30. Double-pulsed fluorescent labels were given with each of 2 fluorochrome markers—calcein before surgical treatment and Oxytetracycline HCl before euthanasia. Histomorphometric analysis was carried out on specimens collected in adjacent regions of the healing defects.
The surface extent and width of the osteoid on fractured (P < 0.01, P < 0.05, respectively) and nonfractured (P < 0.05) sites in the treated group were greater than those in the nontreated group. The net loss of mineralizing surfaces was noticed on both ribs of both groups. Of 11 samples on the fractured side in the treated group, 4 contained periosteal new bone proliferation. There was increased osteoid formation and decreased mineralizing surfaces in the pge1-treated group. Seemingly, administration of pge1 induced bone matrix formation on periosteal envelope adjacent to a fracture site and its contralateral matching site.
Logarithmic normal distribution of incubation times for canine diseases (Sartwell's model)
Authors: Glickman Lawrence T. , Lee Lisa A. , Cohen Noah D. 
Published: February 2025

SUMMARY
The distribution of incubation periods for most infectious diseases follows a logarithmic normal distribution (Sartwell's model). The same is true for human neoplastic diseases of known cause and for genetic diseases, when the age at onset of the disease was used as a surrogate measure of the incubation period. In this study, a similar distribution was observed when Sartwell's model was applied to canine diseases of known genetic cause, but not to diseases of an environmental cause. The model was also applied to canine diseases of suspected multifactorial causes for the purpose of distinguishing between the relative importance of genetic and environmental factors that act before or after birth. Limitations of this method were discussed.
C-reactive protein in dogs
Authors: Caspi D. , Snel F. W. J. J. , Batt R. M. , Bennett D. , Rutteman G. R. , Hartman E. G. , Baltz Marilyn L. , Gruys E. , Pepys M. B. 
Published: February 2025

SUMMARY
Serum concentrations of C-reactive protein (crp) in dogs with various diseases or undergoing various procedures were measured by specific immunoassay. In 20 healthy dogs from various sources, values were all < 5 mg/L, but in 22 healthy dogs from a single source, values ranged from < 5 mg/L in 14 dogs and from 8 to 67 mg/L in 8 dogs. Increased concentrations of serum crp were attained 24 hours after injection of casein (n = 9; median 188 mg/L), ovariohysterectomy (n = 11; median, 144 mg/ L), or elective, nonacute orthopedic surgery (n = 10; median, 83 mg/L). After inoculation of Leptospira interrogans serovar canicola (n = 5), the behavior of serum crp as an acute-phase reactant provided a sensitive and precise objective reflection of in vivo response. The crp concentration in random single-serum samples from 73 dogs with other inflammatory and noninflammatory disorders ranged from normal (< 5 mg/L) to 246 mg/L and generally correlated with the extent and activity of disease.
Time-related responses of spontaneously breathing, laterally recumbent horses to prolonged anesthesia with halothane
Authors: Steffey E. P. , Kelly A. B. , Woliner M. J. 
Published: February 2025

SUMMARY
Cardiovascular and respiratory functions were serially evaluated in ten healthy, fasting, spontaneously breathing, laterally recumbent adult horses during five hours of constant 1.06% alveolar halothane (equivalent to 1.2 times the minimum alveolar concentration for horses). Mean carotid arterial pressure was about 25% higher after one hour of constant-dose halothane than after 30 minutes of constant-dose (P < 0.05), and remained increased throughout the study. Mean carotid arterial pressure peaked after 90 minutes, and was about 30% higher than at 30 minutes. Total peripheral vascular resistance initially increased (20% at one hour), then gradually returned to the 0.5-hour value over the next four hours. Cardiac output progressively increased with time (P < 0.05; 20% by two hours; nearly 40% by five hours) because of an increase in stroke volume. An increase (P < 0.05) in mixed venous PO2 accompanied the increase in cardiac output. Heart rate did not change significantly (P > 0.05). Some measures of ventilation changed significantly with time (P < 0.05). After four and five hours of constant alveolar halothane, the Paco2, inspired gas flow, and ratio of inspired vs expired gas flow were significantly higher than the 0.5-hour values. Inspiratory time significantly decreased, beginning at three hours. All horses recovered from anesthesia and recumbency without complications.
Mixed venous oxygen tension as an estimate of cardiac output in anesthetized horses
Authors: Wetmore L. A. , Derksen F. J. , Blaze C. A. , Eyster G. E. 
Published: February 2025

SUMMARY
The relationship between mixed venous O2 tension and cardiac output was studied in six anesthetized horses breathing 100% O2. Cardiac output, O2 consumption, mean arterial pressure, heart rate, and arterial and venous blood gases were measured after administration of xylazine or dobutamine to horses in lateral, sternal, and dorsal recumbencies. After approximately 3 hours, Escherichia coli endotoxin was administered while horses were in dorsal recumbency, and all measurements were repeated. Relationships between cardiac index (ci) and Pvo2, heart rate, mean arterial pressure, jugular Pvo2, and Pvo2 of blood from a superficial limb vein were evaluated by linear regression analysis. Mean arterial pressure was significantly (P < 0.05) correlated with ci in horses in all positions and after endotoxin administration. However, data points were poorly grouped. Heart rate and ci were significantly correlated in horses in all positions, but not after endotoxin administration. Correlations between jugular Pvo2 and Pvo2 of blood from a superficial limb vein were not significant in horses in sternal recumbency, and Pvo2 of blood from a superficial limb vein was not significantly correlated with ci in horses in lateral recumbency. There was a significant and tight correlation between Pvo2 and ci in horses in all positions and after endotoxin administration.
Dental dolorimetry for the evaluation of an analgesic agent in the horse
Authors: Brunson D. B. , Collier M. A. , Scott E. A. , Majors L. J. 
Published: February 2025

SUMMARY
A monopolar electrode was implanted surgically in the canine tooth dentine layer to evaluate pain threshold responses of horses. A constant-current stimulator was used to deliver a known electrical current to the tooth pulp nerve. A single stimulus of 2-ms duration, repeated at ≥ 20-s intervals, was used to elicit a head lift response. The lowest current level that produced 3 positive head lift responses was recorded as the pain threshold of the horse.
The testing technique, dental dolorimetry, was easily performed. Tooth pulp pain thresholds (tppt) were established on 8 nonmedicated adult male horses. Electrodes were nonreactive and remained functional for up to 98 days. Base-line tppt values were consistent with repeated measurements on the same day and measurements on subsequent test days. The quantity of electrical current necessary to elicit the tppt was increased after administration of xylazine HCl as a test analgesic.
Evaluation of an antigenic fraction of Taenia hydatigena metacestode cyst fluid for immunodiagnosis of bovine cysticercosis
Authors: Kamanga-Sollo Ernest I. P. , Rhoads Marcia L. , Murrell K. Darwin 
Published: February 2025

SUMMARY
An antigenic fraction (ThFAS) isolated from Taenia hydatigena metacestode cyst fluid was used in an elisa to detect antibodies to T saginata in experimentally and naturally infected cattle. In 10 calves given 1,000 to 100,000 T saginata eggs (20% to 60% viability), IgG and IgM antibodies were detected in all the calves by post-inoculation week 3. Immunoglobulin G antibody values remained increased until calves were slaughtered at post-inoculation weeks 13 to 26. Six naturally infected calves (determined by postmortem examination) were considered positive, using the elisa. Shared antigens were demonstrated between ThFAS and T saginata and T crassiceps; there were no shared antigens between ThFAS and Haemonchus contortus or Fasciola hepatica. Specific lectin binding to ThFAS indicated the presence of glycoconjugates. Immunoblot analysis indicated that a low molecular weight polypeptide (10,000 Mr) bears the immunodiagnostic antigen.
Immunoperoxidase evaluation of pneumonic lesions induced by Pasteurella haemolytica in calves
Authors: Haritani M. , Nakazawa M. , Oohashi S. , Yamada Y. , Haziroglu R. , Narita M. 
Published: February 2025

SUMMARY
Calves inoculated with Pasteurella haemolytica serovar 1 developed lesions of coagulation necrosis in the lungs that were sharply demarcated by leukocytes. The P haemolytica antigen was detected in the area of coagulation necrosis in histologic sections, using an immunoperoxidase technique. In the central area of the necrotic tissue, the bacterial antigen was diffusely presented in the necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte. The bacterial antigen also was found in some groups of degenerating leukocytes around the necrotic tissue. The bacterial colonies among these leukocytes had strong specific reactions against P haemolytica. The bacterial antigen was observed in the cytoplasm of macrophages in alveoli around the necrotic lesion. These findings confirmed that coagulation necrosis is an important lesion in calves with pneumonia caused by P haemolytica.
Evaluation of flow-volume curves generated by forced-expiratory spirometry in anesthetized dogs
Authors: Knowlen Grant G. , Hamlin Robert L. , Rice David A. 
Published: February 2025

SUMMARY
Positive-pressure plethysmography was used to generate partial and maximal flow-volume data in 10 anesthetized dogs. Acetylcholine (ACh) administered iv induced significant (P < 0.05) changes in tidal breathing, as evidenced by decreased tidal volume, increased respiratory rate and dynamic resistance, and decreased dynamic compliance.
Partial forced-expiratory spirometry, determined from end inspiratory capacity and functional residual capacity, revealed changes in flow and volume as a result of ACh treatment. These changes were not seen in maximal curves (determined from total lung capacity). Peak expiratory flows were limited by the presence of an endotracheal tube. Use of instantaneous time-constant variables to evaluate the concavity or convexity of the downslope of a flow-volume curve did not reveal differences after iv ACh administration.
Seemingly, partial forced-expiratory spirometry was useful in detecting bronchoconstriction in anesthetized dogs. Accepted techniques of flow-volume curve analysis for the evaluation of small airway function were not sensitive enough to detect bronchoconstriction in the dog.
Relationship between Mycoplasma hyosynoviae infection and front limb weakness in Duroc swine
Authors: Lawrisuk L. S. , Rothschild M. F. , Ross R. F. , Christian L. L. 
Published: February 2025

SUMMARY
A relationship between degree of Mycoplasma hyosynoviae infection and front limb soundness was examined in 254 Duroc swine. These pigs represented 3 lines of pigs (structurally sound, control, and unsound) from a population divergently selected for 4 generations for front limb soundness. Analysis of sera collected every 4 weeks between 6 and 26 weeks of age yielded complement-fixing antibody titers that were believed to be indicative of the degree of natural infection with M hyosynoviae. Analysis of several variables defined by using titer values failed to reveal significant differences among the 3 selected lines, but trends indicated higher mean and peak titer values for pigs from the unsound line. Correlations between titer variables and front limb soundness variables within genetic groups were low and not significantly different from zero. Correlations between all titer variables were calculated; the correlation between mean titer and peak titer was 0.81 (P < 0.01), and between mean titer and age at detection of first titer, was −0.56 (P < 0.01). Pooled heritability estimates were 0.51 ± 0.28 for mean titer and 0.28 ± 0.25 for peak titer.
Papillomavirus genomes in experimentally induced fibromas in white-tailed deer
Authors: O'Banion M. Kerry , Sundberg John P. 
Published: February 2025

SUMMARY
Cutaneous fibromas of white-tailed deer were transmitted successfully to 5 young deer. Serial biopsy specimens of the induced lesions were analyzed for white-tailed deer papillomavirus, using Southern blot hybridization. Viral genomes were found in all specimens taken 1 to 7 weeks after inoculation and, in some cases, from specimens of the inoculation site obtained later. Viral dna was found before histologic evidence of fibroblast proliferation and persisted in low copy number, compared with viral dna of naturally developing fibromas.