bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pneumonie pasteurellosis: Examination of typable and untypable Pasteurella haemolytica strains for leukotoxin production, plasmid content, and antimicrobial susceptibility
Authors: Chang Yung-Fu , Renshaw Harland W. , Young Ry 
Published: February 2025

SUMMARY
Plasmid DNA screening experiments were conducted to determine whether a relationship existed between the presence of plasmids and antibiotic resistance in Pasteurella haemolytica or the capability to produce hemolysin or leukotoxin (cytotoxin). Regardless of plasmid content, all P haemolytica isolates produced characteristic hemolysis on blood agar plates. Similarly, standardized suspensions of living bacteria and sterile concentrated (approx 200:1) culture supernatant from strains representing each of the 15 recognized P haemolytica serotypes and 7 field strains of P haemolytica (biotype A, serotype 1) produced leukotoxin, which was detected by their capability to cause inhibition of the luminol-dependent chemiluminescence response of bovine neutrophils. However, neither living bacterial suspensions nor concentrated culture supernatant from 4 untypable P haemolytica strains or a P multocida strain caused an inhibition of the luminol-dependent chemiluminescence response. The production of neither hemolysin nor leukotoxin by P haemolytica seemed to be plasmid mediated. Leukotoxin production is apparently a stable phenotypic characteristic of pathogenic P haemolytica strains, and the gene(s) coding for this activity is probably located on the bacterial host chromosome. Antibiotic susceptibility profiles were determined for the different bacterial strains. Studies of ampicillin and penicillin resistance in 8 P haemolytica (biotype A, serotype 1) strains provided evidence that the plasmid, with size of approximately 5,200 base pairs, may code for their resistance to these compounds.
Shiga-like toxin production and attaching effacing activity of Escherichia coli associated with calf diarrhea
Authors: Mainil Jacques G. , Duchesnes Christiane J. , Whipp Shannon C. , Marques Lilian R. M. , O'Brien Alison D. , Casey Thomas A. , Moon Harley W. 
Published: February 2025

SUMMARY
Four hundred twenty-nine isolates of Escherichia coli from calves were tested for the production of HeLa cell cytotoxin(s). Isolates that produced enough cytotoxin to be detected in culture supernatants of iron-depleted broth were considered to produce increased amounts of cytotoxins. Isolates also were tested for homology with a DNA probe for a gene that encodes localized adherence of human enteropathogenic E coli. Four isolates produced increased amounts of cytotoxin that was neutralized by Shiga antitoxin (toxin designated as Shiga-like toxin-I [slt-I]). A 5th isolate produced increased amounts of cytotoxin (slt+) that was not neutralized by the Shiga antitoxin, but was neutralized by antitoxin against a variant of slt (toxin designated as slt-II). None of the isolates hybridized with the probe for the localized adherence gene. Three of the slt+ isolates belonged to human enteropathogenic E coli serogroups O26 and O111. All 5 of the slt+ isolates were from calves with diarrhea, but none of the 5 slt+ isolates contained genes for classic heat-labile or heat-stable enterotoxins, for K99 fimbriae, or for invasiveness; neither did any of them adhere to HeLa cells in culture. Three of the 5 slt+ isolates had attaching and effacing activities when inoculated into ligated intestinal loops of rabbits. One of the isolates with attaching and effacing activity in rabbits was originally isolated from a calf with lesions characteristic of those produced by attaching effacing E coli (aeec). Calves inoculated with this slt+ aeec isolate developed focal colonic lesions characteristic of those produced by aeec, but did not develop diarrhea. Seemingly, increased slt production and aeec activity occur together in some E coli isolates from calves in the United States. However, the prevalence of such isolates in the collection studied was low.
Serum agglutinin titers against somatic and flagellar antigens of Campylobacter jejuni and isolation of Campylobacter spp in chickens
Authors: Yoshida Shin-ichiroh , Kaneko Ken-ichi , Ogawa Masuo , Takizawa Takayasu 
Published: February 2025

SUMMARY
From June 1983 to June 1984, two hundred twenty-five 3- to 30-month-old chickens (hens) on 10 different farms were examined for Campylobacter spp. Watering trays and fly vectors also were examined for Campylobacter spp on 6 of the 10 farms. Campylobacter jejuni was isolated from fecal specimens from 64 hens (28.4%), C coli was isolated from 6 hens (2.7%), and C laridis was isolated from 9 hens (4%). The isolation rate of C jejuni was 6.7% to 46.7% for 9 of the 10 farms. On 2 farms, agglutinin titers ≥ 1:40 against somatic and flagellar antigen of C jejuni were detected in hens from which the bacteria were isolated. Hens having titers ≥ 1:40 against C jejuni or hens from which C jejuni had been isolated often occupied adjacent pens. Campylobacter jejuni was isolated from a watering tray on 1 farm and from fly vectors on 2 farms.
Efficacy, safety, and residue evaluation of levamisole gel formulation in sows
Authors: Berger H. , Garces T. R. , Fisher R. K. , DeLay R. L. , Gale G. O. , Boyd J. E. , Simkins K. L. 
Published: February 2025

SUMMARY
Anthelmintic efficacy, safety, and residue studies were conducted in sows and gilts with a levamisole gel containing 11.5% levamisole HCl. In 12 sows and 12 gilts, 8 mg of levamisole HCl equivalent/kg of body weight orally was 100% (resinate) and 91.1% (gel) effective against 55-day-old Ascaris suum and 100% (gel) and 96.1% (resinate) effective against Oesophagostomum dentatum.
In 20 sows given levamisole gel (8 mg of levamisole HCl/kg) orally just before breeding, 4 to 6 weeks after breeding, 4 to 6 weeks before farrowing, and just before farrowing, there were no adverse effects. Transient salivation was noticed in five sows after treatment.
In 4 groups of 4 sows each given levamisole gel orally to provide 8, 24, 40, or 80 mg of levamisole HCl/kg, adverse clinical signs were not observed in sows treated with 8 mg/kg. Transient salivation was noticed in one sow given 24 mg/kg, two sows given 40 mg/kg, and four sows given 80 mg/kg. Multiple emesis and chomping occurred in one sow given 80 mg/kg.
Levamisole residues in edible tissues from sows given 8 mg of levamisole gel/kg orally were < 0.1 mg/kg of muscle and fat in sows killed on posttreatment day (ptd) 3 and < 0.1 mg/kg of kidney in sows killed on ptd 5. Liver residues averaged 0.78 mg/kg in sows killed on ptd 3 and were reduced to 0.31 mg/kg in sows killed on ptd 5. The 99% upper tolerance limit with 95% confidence on the withdrawal time to assure levamisole residues of < 0.10 mg/kg in liver tissue was 11 days.
Acute changes in pancreatic insulin secretion and hepatic glucose kinetics in endotoxemic miniature pigs
Authors: Fettman Martin J. , Hand Michael S. , Van Order Paula , Phillips Robert W. 
Published: February 2025

SUMMARY
We have proposed a misinformed B-cell hypothesis to describe the effects of increased glucose flux across the pancreatic B cell early in endotoxemia, whereby those cells might misinterpret the true glycemic state and thus induce increased insulin release. This hypothesis was supported by the observations that [6-3H]glucose-derived rates of glucose disappearance increased before systemic hyperinsulinemia appeared in endotoxemic Yucatan miniature pigs. Reevaluation of this hypothesis later showed that pancreatic insulin secretion increased before any changes in systemic glucose disappearance or insulin concentrations and, because of significant increases in hepatic insulin extraction, may have led to some local effects of insulin on hepatic carbohydrate metabolism. The present study was conducted with more frequent sampling periods early during endotoxemia to further characterize the effects of this initial acute increase in pancreatic insulin secretion on hepatic glucose uptake, concomitant to net hepatic glucose production, as well as to further clarify the temporal relationships between pancreatic insulin release and the onset of hypoglycemia.
We found that an increase in pancreatic insulin secretion is, indeed, the first event to occur, 30 minutes after initiation of endotoxin infusion, coincidental to the onset of significant decreases in portal and hepatic venous blood flow. [33H]Glucose-derived rate of glucose disappearance first increased significantly at 60 minutes, and net hepatic glucose output increased significantly after 80 minutes of endotoxin infusion. Net [3-3H]glucose uptake by the liver occurred through 50 minutes of endotoxin infusion. After this, there was a significant reversal in transhepatic isotope kinetics, resulting in net release of [3-3H]glucose from the liver for the duration of endotoxin infusion (140 minutes). Rerelease of [3-3H]glucose from the liver occurred coincidental to significant increases in pancreatic insulin secretion, hepatic insulin extraction, and concurrent net hepatic glucose production. This rerelease of [3-3H]glucose from the liver may contribute, in part, to underestimation of [3H]glucose-derived rates of glucose appearance during endotoxemia and account for discrepancies between actual rates of glucose infusion and derived rates of glucose appearance during euglycemic clamps of endotoxemic pigs. The extreme degree of glucoregulatory counterstimulation due to enhanced hepatic insulin extraction, probable increases in glucocounterregulatory hormone secretion, and alterations in hepatocellular energy charge and decreased nucleotide levels may have contributed to increased rates of futile cycling of glucose through hepatic metabolic pathways during acute endotoxemia.
In vitro platelet release by rat megakaryocytes: Effect of heterologous antiplatelet serum
Authors: Handagama P. J. , Jain N. C. , Feldman B. F. , Farver T. B. , Kono C. S. 
Published: February 2025

SUMMARY
A visual assay to study megakaryocte platelet release via proplatelet formation in vitro was established. Samples of megakaryocte-enriched rat bone marrow were incubated (37 C) in rpmi-1640 medium with 15% autologous serum in specially prepared chambers. In the culture system, approximately 6% of megakaryocytes formed proplatelet processes within 24 hours. Inclusion of a heterologous antiplatelet antibody in the culture system inhibited proplatelet formation, compared with that in controls.
Evaluation of granulocyte transfusion in healthy neonatal pony foals
Authors: Morris Debra Deem , Bruce James , Gaulin Ginette , Whitlock Robert H. 
Published: February 2025

SUMMARY
Granulocyte transfusions (gt), 0.98 × 109 neutrophils/Kg of body weight, were performed on 7 healthy pony foals between 2 and 7 days old. The mean neutrophil count of the foals was significantly (P < 0.05) greater than base line (4,830 ± 1,260/μl) 1 hour after gt (8,870 ± 3,350/μl) and was similar to base line by 15 to 18 hours after gt (6,550 ± 2,310/μl).
Leukocyte concentrates (lc) used for gt were harvested from clinically normal adult horses by continuous-flow centrifugation leukapheresis (cl), 3 to 6 hours after hydrocortisone sodium succinate was administered to increase the blood neutrophil count. The mean neutrophil count of the lc used for gt was 68,050 ± 13,990/μl, and the mean lc volume was 377.4 ± 79.2 ml (14.82 ± 3.54 ml/kg). The mean time required to collect the lc used for gt was 232.1 ± 73.4 minutes. Neutrophils from lc had significantly reduced in vitro stimulated migration to zymosan-activated serum, when compared with peripheral blood neutrophils of the donors (P < 0.05). Neutrophil phagocytosis and bactericidal capacity were not significantly changed in lc. Mean neutrophil migration indices were not significantly different in foals after gt.
Mild depression and transient diarrhea was noticed in 1 foal 30 minutes after the start of the gt. The donor of lc for this foal and 1 other donor experienced depression, piloerection, and muscle tremors during cl, indicating that complement had been activated. Problems were eliminated by the use of new disposable plastic materials for blood processing in each cl procedure.
Temporal effects of halothane and isoflurane in laterally recumbent ventilated male horses
Authors: Dunlop C. I. , Steffey E. P. , Miller M. F. , Woliner M. J. 
Published: February 2025

SUMMARY
Cardiopulmonary function was monitored in 6 nonmedicated, healthy male horses, anesthetized with halothane or isoflurane in O2 at a constant dose (1.2 times the minimum alveolar concentration). Horses were exposed once to each anesthetic agent, and a minimum of 2 weeks separated anesthetic exposures. All horses were studied in left lateral recumbency, and ventilation was mechanically controlled to induce a PaCO2 of 35 to 45 mm of Hg and an inspiratory peak airway pressure of 18 to 22 cm of H2O. After 1 hour of horse preparation, constant conditions were begun. With duration of anesthesia, cardiac output increased (P < 0.05) with both anesthetic agents, because of an increase in stroke volume (P < 0.05). Heart rate did not change from initial values with either agent. Mean arterial blood pressure also increased (P < 0.05) with both agents. With both anesthetics, respiratory rate (P < 0.05) was increased progressively to maintain acceptable PaCO2 values. Arterial O2 tension did not change with time.
Response of calves to exposure with swine influenza virus
Authors: Lopez Jorge W. , Woods George T. 
Published: February 2025

SUMMARY
In calves inoculated with live swine influenza virus (siv) A/sw/IL/75 (H1N1) intranasally, siv was isolated for 7 days, and respiratory tract disease was observed. Antibody was detected in serum of inoculated calves from postinoculation day 9, and virus-neutralization antibody was demonstrated on postinoculation days 14 and 21. The primary response was low, but readily differentiated from the secondary response after calves were challenge exposed with homologous siv. Pneumonic lesions were observed at necropsy, and histopathologic changes in airways and lungs were consistently found. Fluorescent staining revealed viral activity in epithelial cells of airways. The virus was transferred to healthy calves housed with inoculated calves.
Comparison of methods used to collect canine intestinal tissues for histologic examination
Authors: Fenwick Brad W. , Kruckenberg S. 
Published: February 2025

SUMMARY
Five commonly used methods of collecting canine intestinal tissues for histologic examination were compared by analysis of the histologic artifact frequency, types, and severity, using a double-blind study design. Tissue samples from the duodenum, jejunum, ileum, and colon from 12 dogs were collected, using the following methods: method 1, longitudinally incising the intestine along the antimesenteric border and stapling the free ends of the intestine to a wooden tongue depressor; method 2, ligating the ends of an unopened length of intestine and injecting the lumen with formalin; method 3, longitudinally incising the intestine along the antimesenteric border and laying the opened intestine on a dry paper towel with the serosal surface down; method 4, placing a segment of unopened and uninjected intestine directly into formalin; and method 5, longitudinally incising the intestine along the antimesenteric border. All tissues were fixed by immersion in neutral-buffered 10% formalin and were processed, using routine histologic techniques. Two of these dogs were perfused iv with formalin before tissues were collected. Samples of intestinal tissue were examined by scanning electron microscopy to confirm the histologic findings.
Method 2 resulted in significantly fewer and less severe artifacts (P < 0.02) than did the other methods. Method 4 resulted in significantly more artifacts of greater severity (P < 0.02) than did the other methods. The number of artifacts and the severity of artifacts induced by methods 1, 3, and 5 were not significantly different. Significantly (P < 0.05) more artifacts and artifacts of greater severity occurred in the duodenum and jejunum than occurred in the ileum and colon, regardless of the method used.
Effect of intramammary devices on the outcome of induced Escherichia coli infection of bovine mammary quarters
Authors: Bright Susan A. , Schultze W. Donald , Paape Max J. , Peters Robert R. 
Published: February 2025

SUMMARY
Eighteen Holstein cows, free of intramammary infection, were fitted with smooth (n = 9) or abraded (n = 9) intramammary devices (imd) in 2 diagonally opposed quarters within 4 weeks after calving. The 2 other quarters of each cow were used as controls. Three to 6 weeks after imd insertion, depending on when milk somatic cell counts returned to a base-line value of < 4 × 105/ml, all cows were subjected to bacterial challenge exposure in the front or rear quarters by intracisternal injection of about 30 colony-forming units of Escherichia coli/quarter. Challenge exposure was done immediately after milking. Three weeks after the initial bacterial exposure, the other quarter pairs were similarly challenge exposed. Quarter bacteriologie status, concentration of milk somatic cells, and clinical observations (rectal temperature, milk appearance, udder palpation, and general condition of the cow) were monitored.
Infection developed in 14 of 16 (88%) quarters with smooth imd vs 16 of 16 (100%) control quarters and in 7 of 17 (41%) quarters with abraded imd vs 17 of 17 (100%) control quarters. The difference in infection frequency between quarters with smooth imd and quarters with abraded imd was significant (P < 0.05). Protection against establishment of infection was associated with somatic cell counts > 8.0 × 105/ml in milk collected immediately after milking (7 of 12 quarters) or 4 hours later (11 of 12 quarters). In 10 quarters (59%) of cows fitted with abraded imd, secretory abnormalities appeared before bacterial challenge inoculation. Abnormal milk or visible blood was observed over periods varying from 2 weeks after insertion through the entire lactation.
Ultrastructure of equine endothelial cells exposed to endotoxin and flunixin meglumine and equine neutrophils
Authors: Turek John J. , Lamar Carlton H. , Fessler John F. , Bottoms Gerald D. 
Published: February 2025

SUMMARY
An in vitro system of cultured equine endothelial cells was evaluated as a model for endotoxin (et) exposure in the horse. Primary cell lines from pulmonary vessels and aortas were cultured from tissues of 6 horses. Effects of et alone with and without serum and in combination with the cyclo-oxygenase inhibitor flunixin meglumine and isolated equine neutrophils were evaluated by transmission electron microscopy. Cells plus serum were incubated with 10, 25, 50, or 100 μg of et/ml of incubation medium for 1, 3, 8, or 24 hours. Cells without serum were cultured for 1 and 3 hours. Flunixin meglumine was used at a concentration of 20 μg/ml. Cells also were incubated in the presence of 1,000, 5,000, or 20,000 neutrophils/ml plus et and in the presence of a combination of et and flunixin meglumine for 1 or 3 hours.
Endotoxin alone did not cause cell damage, and the only evidence of an effect was an increased number of secondary lysosomes at incubation hour 8. At incubation hour 24, cells appeared normal. Endotoxin plus neutrophils caused cells to become round and detach from the growth substrate. Cell pathologic changes included swollen and distorted mitochondria and cytoplasmic vacuolization. Response to the et plus neutrophil combination was variable and ranged from 5% to 50% of the cells being affected. The variability appeared to have some correlation with cell age, as well as individual preparation of neutrophils.
Autumn acquisition of nematodes by calves given a morantel sustained-release bolus the preceding spring
Authors: Yazwinski T. A. , Newby T. J. , Greenway T. E. 
Published: February 2025

SUMMARY
Reinfection with nematodes late in the grazing season was assessed in calves treated the preceding spring with a morantel sustained-release bolus (msrb). During an initial 155-day grazing period, msrb-treated calves (n = 15) grazed a pasture used the preceding year for identically treated calves (msrb pasture). Control calves (n = 15) were not given anthelmintic treatment in the spring and grazed heavily contaminated herbage for the initial 155-day period (control pasture). At the end of the initial grazing period, 3 calves from each group were killed for parasite recovery and counting, with control calves found to harbor 9.2 times more nematodes, compared with the msrb-treated calves. Nematode counts from tracers killed periodically during the initial grazing period were of similar proportions, reflecting the much greater nematode exposure experienced by the control calves, compared with the msrb-treated calves.
At the end of the initial grazing period, 10 calves (5/ group) were placed on a common, contaminated pasture after all were treated twice with fenbendazole (10 mg/kg of body weight, 7 days apart) while on concrete. The second grazing period was for 29 days, followed by a 3-day confinement on concrete. Then, the calves were killed and necropsied. During the 29-day grazing period, the msrb-treated calves maintained their weight advantage over the control calves, and significant differences in nematode egg counts were not found between the 2 groups of calves. At necropsy, the msrb-treated calves harbored 27.9% fewer nematodes than did the controls, indicating that prior therapeutic and prophylactic anthelmintic activities of the msrb did not predispose the animals to enhanced acquisition of nematodes after msrb protection.
Imidocarb and parvaquone in the treatment of piroplasmosis (Babesia equi) in equids
Authors: Kuttler K. L. , Zaugg J. L. , Gipson C. A. 
Published: February 2025

SUMMARY
The therapeutic efficacies of imidocarb and parvaquone were tested against Babesia equi of European origin in carrier horses and for induced acute infections in splenectomized ponies.
Imidocarb, at a dosage of 4 mg/kg of body weight, given im at 72-hour intervals 4 times, was ineffective in eliminating B equi-carrier infection in 9 mature geldings. A single im administration of 4 mg/kg was not therapeutic in acutely infected splenectomized ponies. When given at 3 different dosages and treatment schedules, parvaquone was ineffective in clearing carrier infection. Parvaquone given im once at a dosage of 20 mg/kg was effective for acute B equi infections in splenectomized ponies; parasitemia began to decrease within 24 hours after treatment. Infections were not eliminated however, and within 4 weeks, secondary parasitemia and anemia developed. Of 4 ponies, 3 died of acute piroplasmosis.
Comparison of various anesthetic regimens in the domestic fowl
Authors: Christensen Jan , Fosse Richard T. , Halvorsen Ole Johan , Morild Inge 
Published: February 2025

SUMMARY
Three anesthetic agents (equithesin, metomidate, and ketamine) combined with diazepam were tested in the domestic fowl. Laparotomy and thoractomy were possible with the equithesin/diazepam combination, but only laparotomy was possible with the metomidate/diazepam combination. The combination of ketamine/diazepam did not result in the depth of anesthesia required for surgical procedures. Repeated blood pressure and heart rate measurements were recorded by use of a modified noninvasive Doppler technique.
Equithesin/diazepam was our combination of choice for long-duration surgical anesthesia. The depth of anesthesia could be modulated by increasing the dose of diazepam. Metomidate/diazepam was useful when short-term anesthesia was required. In contrast to equithesin/diazepam, the metomidate/diazepam combination provided unstable anesthesia of varying depth and duration. Adverse reactions with metomidate indicated caution when using this drug in chickens; the drug also caused marked bradycardia. Ketamine/diazepam combination cannot be recommended as an anesthetic agent for use in chickens. The combination may be useful for minor surgical procedures or treatment, but not for experimental procedures that involve major surgery. Diazepam alone had a slight tranquilizing effect.