bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of pharmacokinetics and pharmacodynamics of flunixin in calves by use of pharmacokinetic/phannacodynamic modeling
Authors: Landoni Maria F. , Cunningham Fiona M. , Lees P. 
Published: January 2024

SUMMARY
Pharmacokinetic and pharmacodynamic variables of flunixin were studied in calves after IV administration of the drug at a dose rate of 2.2 mg/kg of body weight. The anti-inflammatory properties of flunixin were investigated, using a model of acute inflammation; this involved surgically implanting tissue cages at subcutaneous sites and stimulating the tissue cage granulation tissue by intracavitary injection of carrageenan. The actions of flunixin on exudate concentrations of several substances related to the inflammatory process, including proteases (metalloprotease [active and total] and cysteine and serine proteases), enzymes (lactate dehydrogenase, acid phosphatase, and β-glucuronidase [β-glu]), eicosanoid (prostaglandin E2 [pge2], leukotriene B4, and serum thromboxane B2 [txb2]) concentrations, and bradykinin (BK)-induced edema, were investigated.
Flunixin had a long elimination half-life—6.87 ± 0.49 hours—and volume of distribution was 2.11 ± 0.37 L/kg, indicating extensive distribution of the drug in the body. Body clearance was 0.20 ± 0.03 L/ kg/h.
Flunixin exerted inhibitory effects on serum txb2 and exudate pge2 concentrations, β-glu activity, and BK-induced swelling. Other enzymes and inflammatory mediators were not significantly affected. Pharmacokinetic/pharmacodynamic modeling of the data revealed similar mean concentration producing 50% of the maximal effect values for inhibition of exudate pge2 and p-glu and of BK-induced swelling (0.070 ± 0.006, 0.064 ± 0.040, and 0.061 ± 0.030 μg/ml, respectively). A lower concentration producing 50% of the maximal effect value was obtained for inhibition of serum txb2 concentration (0.023 ± 0.004 μg/ml). Differences also were observed in equilibration halflife for these actions, suggesting the existence of 3 distribution compartments correlating with 3 sites of action—a central compartment and shallow and deep peripheral compartments. Pharmacokinetic/pharma- codynamic modeling proved to be a useful analytical method, providing a quantitative description of in vivo drug pharmacodynamics and indicating possible mechanisms of action.
Characterization of iron status in young dogs with portosystemic shunt
Authors: Bunch Susan E. , Jordan Holly L. , Sellon Rance K. , Cullen John M. , Smith Joseph E. 
Published: January 2024

SUMMARY
Microcytosis is a common laboratory finding in dogs with congenital portosystemic shunt (pss), although its pathogenesis is not yet understood. Because the most common cause of microcytosis in dogs is absolute or relative iron deficiency, iron status was evaluated in 12 young dogs with pss. Complete blood counting was done before surgical correction in all dogs, and in 5 dogs after surgery, by use of an automated hematology analyzer. Serum iron concentration and total iron-binding capacity (tibc) were determined coulometrically, and percentage of transferrin saturation was calculated. Erythrocyte protoporphyrin content was quantified by use of front-face fluorometry. Serum ferritin concentration was measured by use of elisa. Serum ceruloplasmin content was determined colorimetrically (with p-phenylene-diamine dihydrochloride as substrate) as an indirect indicator of subclinical inflammation, which may result in impaired iron utilization. Special stains were applied to liver (10 dogs; Gomori's) and bone marrow aspiration biopsy (7 dogs; Prussian blue) specimens for qualitative assessment of tissue iron content. Nonpaired Student's t-tests were used to compare serum iron concentration, tibc, percentage of transferrin saturation, and erythrocyte protoporphyrin, ferritin, and ceruloplasmin concentrations in dogs with pss with those in clinically normal dogs. All dogs had microcytosis before surgery; microcytosis resolved in 3 dogs after surgical correction. Serum iron concentration and tibc were significantly lower in pss-affected dogs than in clinically normal dogs. Erythrocyte protoporphyrin, ferritin, and ceruloplasmin concentrations in pss-affected dogs were not significantly different from those in healthy dogs. Excess iron was not detected consistently in liver or bone marrow samples. These results suggest that relative iron deficiency, perhaps associated with altered iron transport and not absolute iron deficiency, is related to microcytosis in dogs with pss.
Vaccination of cattle with outer membrane protein-enriched fractions of Pasteurella haemolytica and resistance against experimental challenge exposure
Authors: Morton Rebecca J. , Panciera Roger J. , Fulton Robert W. , Frank Glynn H. , Ewing Sidney A. , Homer John T. , Confer Anthony W. 
Published: January 2024

SUMMARY
Administration of an N-lauroylsarcosine-derived outer membrane protein fraction of Pasteurella haemolytica A1 (sci-1) induced a protective response in calves against intrathoracic challenge exposure with the homologous serovar. Outer membrane proteins from heterologous serovars, A6 and A9, induced partial protection that was associated with their respective similarities to serovar A1 in outer membrane protein profiles derived by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Calves vaccinated with sci preparations did not have detectable neutralizing antibody to P haemolytica A1 leukotoxin. Antibodies to whole-cell antigens, carbohydrate-protein subunit antigen, and sci-1 were associated with resistance, which indicates that protein antigens shared among cell surface, carbohydrate-protein subunit, and sci preparations are immunogenic and enhance resistance to experimental challenge exposure.
In vitro of modulation of bovine blood neutrophils and mononuclear cells by oxytetracycline
Authors: Myers Michael J. , Farrell Dorothy E. , Henderson Mark 
Published: January 2024

SUMMARY
The effect of oxytetracycline (otc) on bovine blood mononuclear cells and neutrophil functions was examined in vitro. Neutrophil functions tested include respiratory burst, peroxidase, and antibacterial activities. Neutrophils were treated with otc (10 to 1,500 μg/ml) before exposure to either opsonized zymosan or bacteria. A dose-response inhibition antibacterial activity to high concentrations of otc (500 to 1,000 μg/ml) was observed. Beginning at a concentration 15 μg/ml, otc treatment of neutrophil lysates resulted in decreased peroxidase activity. A dose response was not observed. In contrast, respiratory burst, measured by nitroblue tetrazolium dye reduction, increased after otc exposure, but only at high concentrations (500 and 1,000 μg/ml) of otc. Mitogen-induced proliferation of blood mononuclear cells cocultured with otc and concanavalin A, phytohemagglutinin-P, or pokeweed mitogen was inhibited at an otc concentration of 100 μg/ml at 48 and 72 hours of culture. These results indicate that blood mononuclear cells are more sensitive to the inhibitory effects of otc than are neutrophils. Furthermore, the otc-mediated inhibition of neutrophil antimicrobial activity is inversely related to the increase in nitroblue tetrazolium reduction. This suggests that otc is uncoupling the hexose monophosphate shunt from production of secreted oxygen radicals. These results also suggest that the peroxidase enzyme system has a large biological reserve capacity.
Tumor necrosis factor-α Production in swine after oral or respiratory challenge exposure with live Salmonella typhimurium or Salmonella choleraesuis
Authors: Stabel Thomas J. , Fedorka-Cray Paula J. , Gray Jeffrey T. 
Published: January 2024

SUMMARY
A series of experiments was conducted to document tumor necrosis factor-α (tnf) activity in serum of swine after inoculation with Salmonella spp endotoxin and after oral or respiratory tract challenge exposure with live Salmonella spp. For experiment 1, a potentially lethal dose of S typhimurium endotoxin (25 μg/kg of body weight) was administered iv, and serum tnf activity was measured. High tnf (approx 700 IU/ml) activity at 1 to 2 hours after administration of the inoculum was associated with death, whereas lower tnf (approx 30 IU/ml) activity was associated with a general prolonged state of shock. For experiment 2, pigs were administered a nonlethal dose (5 μg/kg, iv) of either S typhimurium or S choleraesuis endotoxin. Difference in the ability to induce porcine serum tnf activity was not observed between strains. During experiment 3, pigs were inoculated with 104 colony-forming units of S typhimurium χ4232 either orally by gelatin capsule (gc) or by intranasal (in) instillation. A late serum tnf response (17 IU/ml) was measured at 6 weeks after in inoculation. A serum tnf response was not detected in gc-inoculated pigs. All tissues and feces were test-negative for S typhimurium prior to the 6-week tnf response. Serum tnf activity may be related to clearance of S typhimurium after respiratory tract exposure, but it is not important to or indicative of clearance of orally presented S typhimurium in swine. During experiment 4, pigs were inoculated with 106 colony-forming units of S typhimuriumχ4232 similarly as for experiment 3. Challenge exposure with this medium-size dose of inoculum induced a prolonged peak serum tnf response (37 IU/ml) between 2 and 4 weeks after in inoculation. Again, serum tnf activity was not detected in gc-inoculated pigs. Data suggest that clearance of a medium-size dose (106) of inoculum may be influenced by the prolonged higher serum tnf activity. For experiments 5 and 6, pigs were inoculated in with 103, 106, 108, or 109 S choleraesuis χ3246. A measurable, yet statistically nonsignificant, serum tnf response was observed for all doses. Pigs inoculated by gc with 108 S choleraesuis χ3246 had similar results. High doses (> 106) of live S choleraesuis were associated with clinical signs of endotoxic shock. Clearance of S choleraesuis, or lack thereof, did not correlate with serum tnf activity.
Efficacy of a variety of disinfectants against Actinobacillus pleuropneumoniae serotype 1
Authors: Gutiérrez César B. , Barbosa José I. Rodríguez , Suárez Juan , González Óscar R. , Tascón Rubén I. , Ferri Elías F. Rodríguez 
Published: January 2024

SUMMARY
The efficacy of 23 disinfectants (including the most commonly used chemical groups) and 6 quaternary ammonium compound based commercial formulations against Actinobacillus pleuropneumoniae serotype 1 (ATCC 4074) was studied. The organisms were tested in suspension and carrier tests with serum as the organic matter. Chloramine-T, hydrogen peroxide, glutaraldehyde, and mercurochrome alone, and a quaternary ammonium compound formulation containing 10% benzalkonium chloride, 2.5% glutaraldehyde, 6.8% glyoxal, and 6% formaldehyde were effective in all tests, regardless of the presence or absence of organic load. All but 2 of the nonformulated disinfectants (sodium hypochlorite and an iodophor) caused at least a 3-log10 reduction in colony-forming units in the suspension test. However, most of the disinfectants were not as effective in the carrier test as in the suspension test; this difference ranged from a 1- to 5-log10 reduction in colony-forming units. In addition, the presence of serum considerably reduced the disinfectant capacities of most of the compounds tested, particularly in the carrier test. These results indicate the importance of selecting suitable disinfectants for routine use on surfaces contaminated with this organism, especially in the presence of organic matter. Chloramine-T and the aforementioned commercial formulation were also tested directly under field conditions in pig nurseries, confirming their high effectiveness.
Enzymatic analysis of liver samples from rainbow trout for diagnosis of blue-green algae-induced toxicosis
Authors: Sahin Ali , Tencalla Francesca G. , Dietrich Daniel R. , Mez Konstanze , Naegeli Hanspeter 
Published: January 2024

SUMMARY
Microcystin and related toxic peptides produced by cyanobacteria (blue-green algae) are potent and selective inhibitors of protein phosphatases 1 and 2A. We adapted existing enzymatic techniques to analyze the liver of rainbow trout after oral administration of hepatotoxic cyanobacteria. Liver tissue was removed 3 and 12 hours after treatment, and phosphatase activity was determined in liver extracts, using a specific phosphoprotein substrate. In all samples from fish exposed to toxic cyanobacteria, phosphatase activity was suppressed, whereas the control enzyme, lactate dehydrogenase, present in the same liver extract, was not affected by cyanobacteria. Thus, experimental poisoning by hepatotoxic cyanobacteria resulted in an abnormally low ratio of phosphatase to lactate dehydrogenase activity in the liver extracts. These results indicate that specific inhibition of phosphatases 1 and 2A may provide a useful diagnostic tool to determine the early effects of cyanobacteria toxic peptides directly in liver samples from poisoned animals. Although this test was developed with rainbow trout, it should be possible to extend the analysis of liver phosphatase activity to other species, including sheep and cattle, which are frequently affected by hepatotoxic cyanobacteria.
Heritability of the depth of the opening of the ciliary cleft in Samoyeds
Authors: Ekesten Björn , Torrång Ingrid 
Published: January 2024

SUMMARY
Ocular examination, including gonioscopy and ultrasonographic biometry (biological measurement), was performed in healthy, purebred Samoyeds. When the dogs were subclassified according to the degree of kinship with cases of primary angle-closure glaucoma, it was found that the opening of the ciliary cleft was wider in dogs less related to dogs with primary angle-closure glaucoma than in more closely related dogs. Furthermore, multivariate analysis of the material indicated that parentage of a dog has a substantial effect on the intraocular distances studied in this investigation (relative depth of the opening of the ciliary cleft, relative corneal thickness, relative anterior chamber depth, relative lens thickness, and relative length of the vitreous body). Finally, heritability of the relative depth of the opening of the ciliary cleft was estimated at 56% and that of the common environmental factor at 19%. The results are indicative of a hereditary component in primary angle-closure glaucoma in the Samoyed breed.
Pharmacokinetics of enrofloxacin in clinically normal dogs and mice and drug pharmacodynamics in neutropenic mice with Escherichia coli and staphylococcal infections
Authors: Meinen Jeffrey B. , McClure J. T. , Rosin Eberhard 
Published: January 2024

SUMMARY
Pharmacodynamic variables of enrofloxacin were investigated in a neutropenic mouse Escherichia coli and staphylococcal thigh infection model. Enrofloxacin pharmacokinetics in clinically normal mice and dogs were compared to confirm that doses evaluated in the mouse model would include enrofloxacin doses appropriate for use in dogs. Mice were made neutropenic by treatment with cyclophosphamide and injected in the thigh muscle with approximately 106 colony-forming units of E coli (n = 2) or a staphylococcal (n = 2) clinical isolate. Enrofloxacin dosages tested ranged from 0.78 to 50 mg/kg of body weight and 6.25 to 200 mg/kg in the E coli and staphylococcal infection trials, respectively. In each 24-hour dosage trial, enrofloxacin was administered SC as a single dose or in divided doses given every 3, 6, or 12 hours. Comparison of log10 colonyforming units per thigh muscle in untreated control mice and mice treated with enrofloxacin was used as a measure of efficacy. Two-way anova was used to determine that the enrofloxacin total dose, but not the dose frequency, was significant in determining drug efficacy. Pharmacokinetic values analyzed by use of multivariant stepwise linear regression analysis indicated that the area under the concentration-time curve, but not time above minimum inhibitory concentration, was significant in predicting efficacy of enrofloxacin treatment. We conclude that enrofloxacin killing of E coli and staphylococci is concentration dependent and not time dependent.
Comparison of the effects of low-molecular-weight and unfractioned heparin in horses
Authors: Monreal Luis , Villatoro Antonio J. , Monreal Manuel , Espada Yvonne , Anglés Anna M. , Ruiz-Gopegui Rafael 
Published: January 2024

SUMMARY
Thirty healthy male horses were allotted to 3 groups and treated blindly during 4 days. Group-1 horses received unfractioned calcium heparin (100 IU/kg of body weight, sc, q 12 h). Group-2 horses received a single dose of a low-molecular-weight heparin (50 anti-Xa IU/kg, sc) every morning, and a similar volume of saline solution every evening. Group-3 horses received the vehicle (saline solution), sc, every 12 hours. Citrated and edta-anticoagulated blood samples were collected before starting the medication (T-0) and once daily 3 hours after each morning injection (T-3, T-27, T-51, and T-75). The pcv, hemoglobin concentration, rbc and platelet counts, and clotting times (activated partial thromboplastin time and thrombin time) were determined, and a microscopic examination to detect hemagglutination was performed. Plasma concentration of heparin was measured by use of the antifactor Xa activity assay. Bleeding time was determined on the first and fourth days, using a double-template method.
The horses given unfractioned heparin had marked agglutination of erythrocytes after the first injection that became more pronounced as treatment progressed. Also, significant decrease in pcv, hemoglobin concentration, and rbc count was observed during treatment. Platelet count was significantly decreased after the first day, and clotting times were significantly prolonged. In contrast to the horses given unfractioned heparin, those given low-molecular-weight heparin did not have any agglutination of erythrocytes during the 4 days of treatment, and there were no significant changes in pcv, hemoglobin concentration, or rbc and platelet counts. Activated partial thromboplastin time increased slightly in the horses given low-molecular-weight heparin, although the values remained within reference range. Both groups of horses achieved adequate concentrations of heparin in plasma for prophylactic purposes, but those given low-molecular-weight heparin achieved those values after the first injection. Bleeding times were not significantly different between heparin-treated horses and horses given saline solution during treatment.
We conclude that low-molecular-weight heparin may be used more safely and conveniently in horses, because it does not affect equine erythrocytes, platelets, or clotting and bleeding times.
Demonstration of tank effect on growth indices of juvenile rainbow trout (Oncorhynchus mykiss) during an ad libitum feeding trial
Authors: Speare David J. , MacNair Neil , Hammell K. L. 
Published: January 2024

SUMMARY
Growth indices were examined in 24 identically managed tanks, each containing 120 diploid juvenile rainbow trout (initial mean body weight, 9.3 g), during a 12-week study to examine tank effects associated with tank location in a multi-user research facility. Growth indices included mean body weight, feed intake, feed conversion index, and specific growth rate. The null hypothesis that tank effect had no effect on growth over the 12-week period was rejected (P = 0.038), and mean weight in individual tanks differed by as much as 18.7%. During the study, it was determined that the proximity of tanks to common-use walkways in the facility could affect growth indices. This was indicated by significant differences in the mean fish weights among blocks of tanks served by different header tanks after 4 (P = 0.001) and 8 (P = 0.024) weeks. The block containing tanks of fish with the highest mean weight was nearest to the 2 common-use walkways in the facility. Fish in this block of tanks, compared with those in other blocks, had significantly greater feed intake but no significant differences in conversion efficiency. Compensatory growth, a well known growth attribute in fishes, diminished the difference in mean weight between these blocks of tanks by the end of the study. Comparison of paired tanks within header tank blocks indicated that fish in those located nearest to walkways had higher feeding rates over the 12-week period (P = 0.048), but less efficient feed conversion (P = 0.040) than did fish in matched tanks located farthest from walkways. However, there were no differences in mean weight of fish. Results of this trial document the risks involved in identifying fish in a tank as the experimental unit when treatments are administered to the tank of fish, the latter being the true experimental unit.
Ruminal microbial alterations associated with sulfide generation in steers with dietary sulfate-induced polioencephalomalacia
Authors: Cummings B. A. , Gould D. H. , Caldwell D. R. , Hamar D. W. 
Published: January 2024

SUMMARY
Holstein steers were fed carbohydrate-rich, short-fiber basal diets with and without added sodium sulfate. Steers fed the high-sulfate diet developed the cns disorder polioencephalomalacia (pem). The onset of signs of pem was associated with increased sulfide concentration in the rumen fluid. Over the course of the disease, anaerobic rumen bacteria were enumerated in roll tubes by use of the Hungate method to determine the effect of dietary sulfate on sulfate-reducing bacterial numbers. Media used included a general type for total counts and sulfate-containing media with and without cysteine to assess sulfate-reducing bacteria. Changes in total and sulfate-reducing bacterial numbers attributable to dietary sulfate content were not observed. The capacity to generate hydrogen sulfide from sulfate in fresh rumen fluid in vitro was substantially increased only after steers had been fed the high-sulfate diet for 10 to 12 days, which coincided with the onset of signs of pem. The low capacity for hydrogen sulfide production of rumen fluid taken at earlier times in the feeding period suggests that rumen microorganisms must adapt to higher dietary sulfate content before they are capable of generating potentially toxic concentrations of sulfide.