bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification of surface-exposed integral outer membrane proteins of Actinobacillus pleuropneumoniae and their role in opsonophagocytosis
Authors: Thwaits Richard N. , Kadis Soloman
Published: January 2024

Previously identified 39-, 50-, and 76-kd integral outer membrane proteins (iomp) of Actinobacillus pleuropneumoniae, a respiratory tract pathogen, were separated by electroelution of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-obtained fragments and their role in opsonophagocytosis by porcine leukocytes was investigated by flow cytometry of fluorescein-labeled A pleuropneumoniae. Using specific antisera, immunoblot analysis indicated that the 3 proteins were antigenically distinct. Antibodies against each iomp have an important role as opsonins for phagocytosis by porcine leukocytes. The effect of using a combination of all 3 of the specific antisera was minimal. Antiserum absorbed against intact A pleuropneumoniae and Escherichia coli organisms indicated that the antibodies to the 39-, 50-, and 76-kd iomp were specific for A pleuropneumoniae antigens. Nonheat-treated antiserum did not increase phagocytosis, compared with heat-inactivated antiserum, indicating that complement may not have a major role in opsonization of A pleuropneumoniae.
Association of host cell mitochondria with developing Toxoplasma gondii tissue cysts
Authors: Lindsay D. S. , Mitschler R. R. , Toivio-Kinnucan M. A. , Upton S. J. , Dubey J. P. , Blagburn B. L.
Published: January 2024

Ultrastructure of the interactions of host cell mitochondria with developing Toxoplasma gondii tissue cysts was examined in cultured cells, using transmission electron microscopy of infected cells and rhodamine 123 (a mitochondria-specific vital fluorescent dye) staining of isolated tissue cysts. Structurally mature T gondii tissue cysts were observed as early as 2 days after inoculation of cultured cells. During development of T gondii, host cell mitochondria were observed surrounding the parasitophorous vacuole membrane. Mitochondria became flat and elongated in the vicinity of the parasitophorous vacuole membrane. These mitochondria were also closely associated with T gondii tissue cysts. Incubation of tissue cysts from cultured cells and tissue cysts from mouse brains with rhodamine 123 revealed fluorescence of the tissue cyst wall in living specimens. Incubation of tissue cysts with 10 µM rotenone caused diminished fluorescence of the tissue cyst walls, and 100 µM rotenone caused complete inhibition. Mouse RBC, and tissue cysts fixed in 100% methanol did not fluoresce after exposure to rhodamine. Tissue cysts in 9 isolates of T gondii from mouse brains were examined, using rhodamine 123, and the tissue cyst walls of all isolates fluoresced, indicating no isolate effects. Our results indicate that host cell mitochondria may be closely associated with the tissue cysts of T gondii in cell cultures and in mice.
Modulation of bronchial responsiveness in horses by phenylbutazone and furosemide
Authors: Aguilera-Tejéro E. , Pascoe J. R. , Woliner M. J.
Published: January 2024

Effects of phenylbutazone (pbz) and furosemide (fur) on the respiratory tract of horses were evaluated, focusing on bronchial responsiveness. Four healthy Thoroughbreds were used and data were analyzed by use of a Latin square design. Histamine provocation tests (0.5, 1, 2, and 4 µg/kg/min, iv) were done: (1) without prior treatment with pbz or fur, (2) 30 minutes after administration of pbz (8 mg/kg, iv), (3) 1 hour after administration of fur (1 mg/kg, iv), and (4) after administration of pbz plus fur. Pulmonary function tests (dynamic compliance, resistance, respiratory frequency, and tidal volume) and heart rate were monitored throughout the experiments. Phenylbutazone did not influence basal pulmonary function test results, whereas fur caused a significant (P < 0.05) increase in dynamic compliance and decrease in resistance. Histamine infusion resulted in a dose-dependent decrease in dynamic compliance and a dose-dependent increase in resistance, respiratory frequency, and heart rate. Phenylbutazone administration significantly (P < 0.05) attenuated most of the changes induced by histamine, whereas fur had less protective action. Administration of pbz plus fur before administration of histamine was less effective than administration of pbz alone.
Prevention of scrapie transmission in sheep, using embryo transfer
Authors: Foote Warren C. , Clark Wilber , Maciulis Alma , Call Jay W. , Hourrigan James , Evans R. Cole , Marshall Michael R. , de Camp Margarete
Published: January 2024

Reciprocal embryo transfers were made between scrapie-inoculated and scrapie-free sheep (Cheviot and Suffolk breeds) to measure scrapie transmission via the embryo (using offspring from embryos of scrapie-inoculated donors and scrapie-free recipients) and via the uterus (using offspring from embryos of scrapie-free donors and scrapie-inoculated recipients taken by cesarean section). Two control groups of offspring, 1 from scrapie-free parents (negative) and 1 from scrapie-inoculated parents (positive), also were included. All sheep were observed for clinical signs of scrapie until death or for a minimum of 60 months. Final diagnosis was made on the basis of histopathologic findings or results of mouse inoculation and/or proteinase-K-resistant protein analysis. Thirty to 61% of the scrapie-inoculated donor/recipient sheep within groups developed scrapie within 8 to 44 months after inoculation. None of the scrapie-free donor/recipients, including those gestating embryos from scrapie-inoculated donors, developed scrapie. Also, none of the offspring observed to ≥ 24 months of age from reciprocal cross, via embryo (0/67), or via the uterus (0/25), or from the negative-control group (0/33) developed scrapie. Fifty-six of the offspring via embryo, 19 of these via the uterus, and 31 negative controls survived to ≥ 60 months of age. Of the 21 sheep in the positive-control group, 2 (9.5%) developed scrapie, 1 at 31 months of age and 1 at 42 months of age. In the Cheviot offspring, the percentage of sheep carrying the short incubation allele ranged from 24 to 44% and the percentage in the Suffolk offspring ranged from 61 to 83%. These proportions indicate high degree of susceptibility to the disease. Results indicate that under the conditions of these experiments, scrapie was not transmitted to the offspring via the embryo or the uterus.
Sonographic brightness of the flexor tendons and ligaments in the metacarpal region of horses
Authors: Wood A. K. W. , Sehgal C. M. , Polansky M.
Published: January 2024

Sonographic observations were made of the image mean gray scale (mgs) of the flexor tendons and ligaments in the left and right metacarpal regions of each of 10 clinically normal horses. In images made in the dorsal and sagittal planes, the mgs was measured at multiple sites in the superficial digital flexor tendon (sdft), deep digital flexor tendon (ddft), accessory ligament (al), and suspensory ligament (sl), and at single sites in the medial and lateral limbs of the sl, and the palmar ligament. Relative sonographic brightness of each tendon and ligament was calculated by dividing the value of its mgs by the mean value for the mgs of images of 3 soft tissue equivalent phantoms. When a multivariate repeated-measures of anova of the relative brightness values was statistically significant (P ≤ 0.05), Tukey's method of multiple comparisons was used to determine which values were significantly different from each other. In the dorsal plane, the sl was significantly brighter than the ddft, sdft, and al; relative brightnesses of the ddft and sdft were similar, as were those of the sdft and al. In the sagittal plane, the sl again was the significantly brightest structure, followed by the al, and similar brightnesses of the ddft and sdft. In dorsal images made 25 cm distal to the accessory carpal bone, relative brightnesses of the sdft, ddft, and the medial and lateral limbs of the sl were similar. In images made 30 cm distal to the accessory carpal bone, relative brightness of the palmar ligament was significantly (P < 0.05) less than that of the sdft and ddft in the dorsal plane, but not in the sagittal plane, where it was significantly greater. Relative brightness values represented a unique sonographic characteristic of each structure and, in the future, may provide further insights into tendon and ligament structure and function.
Comparative effects of xylazine and propofol on the urethral pressure profile of healthy dogs
Authors: Combrisson Hélène , Robain Gilberte , Cotard Jean Pierre
Published: January 2024

The effects of 2 drugs, xylazine and propofol, on the urethral pressure profile were compared. Seven female dogs were sedated by administration of one drug, then the other, and urethral variables were measured. In the dogs sedated with propofol, the mean ± sd, maximal urethral closure pressure (51 ± 7.4 cm of H2O) was significantly (P < 0.05) higher than the value when dogs were sedated with xylazine (23.3 ± 7.6 cm of H2O). Results were compared with those obtained by various authors, in particular for nonsedated dogs. It is concluded that propofol is a good drug for investigation of the urethral pressure profile, whatever its effect on maximal urethral closure pressure.
Joint laxity and its association with hip dysplasia in Labrador Retrievers
Authors: Lust George , Williams Alma J. , Burton-Wurster Nancy , Pijanowski Gerald J. , Beck Kathy A. , Rubin Gail , Smith Gail K.
Published: January 2024

A study was done to determine whether radiographic-distraction measurement of coxofemoral joint (hip) laxity at 4 and 8 months of age can serve as a predictor of hip dysplasia in older Labrador Retrievers. The method of Smith, Biery, and Gregor was used for radiologic examination of hips and for evaluation of radiographs. Mean (± sem) distraction laxity (ie, distraction index) for 10 adult disease-free dogs was 0.29 ± 0.05, whereas a group of 8 dogs with dysplastic hips had mean distraction index of 0.60 ± 0.10 (P < 0.05). Mean distraction index at 4 months of age for 11 pups of 4 litters from matings between dogs with normal hips was 0.39 ± 0.07, and was 0.54 ± 0.04 for 31 pups of 7 litters from matings between dogs with hip dysplasia. The distraction index and, thus, joint laxity at that age was significantly (P = 0.0351) different for the 2 groups. The distraction index at 4 months correlated positively with the distraction index at a later age at necropsy (r = 0.43; P = 0.0289). Distraction index < 0.4 at 4 months of age predicted normal hips in 88% of cases and distraction index ≥ 0.4 predicted hip dysplasia in 57% of the dogs. Logistic regression modeling indicated that the odds of a hip being normal decreased with increasing distraction index, and thus, with increasing joint laxity. The logistic regression models provided a reasonable mathematical description of the data. Based on the logistic model of the data, distraction indexes between 0.4 and 0.7 at either 4 or 8 months of age were not associated strongly enough with evidence of disease to be clinically reliable in predicting, on an individual basis, the outcome for dysplastic hip conformation when dogs were older. Index > 0.7 was associated with high probability for developing dysplastic joints and distraction index < 0.4 predicted normal hips with high probability.
Effect of serum from dogs infected with Dirofilaria immitis on endothelium-dependent relaxation of rat aorta in vitro
Authors: Lamb Victoria L. , Williams Jeffrey F. , Kaiser Lana
Published: January 2024

Endothelium-dependent relaxation of canine femoral artery in vivo is depressed in dogs infected with Dirofilaria immitis (heartworms). In vitro, endothelium-dependent relaxation of aorta from rat is depressed in the presence of adult heartworms or heartworm-conditioned media. The depression of relaxation is attributable, in part, to a low molecular weight, biologically active product that is released by the adult parasites. Because heartworms reside in the right heart and pulmonary arteries, biologically active factors produced by the parasites could circulate and alter endothelial cell function. The hypothesis that filarial factors in serum from heartworm-infected dogs depress endothelium-dependent relaxation was tested. Rings of thoracic aorta from rats were constricted by use of norepinephrine, and cumulative dose-response relationships to methacholine and nitroglycerin were evaluated in the presence of serum from heartworm-infected dogs or serum from noninfected (control) dogs. Nitroglycerin relaxation was not different; however, methacholine relaxation was significantly depressed in rings exposed to serum from heartworm-infected dogs when compared with that of controls. These results supported the hypothesis and suggested that circulating filarial factors have the potential to influence the behavior of any endothelial cell surface.
Effect of dose and method of administration of endotoxin on cell mediator release in neonatal calves
Authors: Gerros Terry C. , Semrad Susan D. , Proctor Richard A. , LaBorde Alice
Published: January 2024

The cellular response induced in the host animal by endotoxin contributes greatly to the morbidity and mortality of gram-negative infections in bovine neonates. We characterized the temporal sequence, magnitude, and duration of mediator release during endotoxemia and evaluated the effect of endotoxin dose and method of administration. Thromboxane B2 (TxB2), and 6-keto prostaglandin F1α (PGFlα) concentrations and tumor necrosis factor (tnf), and interleukin-1β (il-1β) activities were measured in 34 newborn calves given Escherichia coli endotoxin at dosage of 0 (saline solution), 0.2, 2.0, or 20 μg/kg of body weight, either by iv administered bolus or infusion over 50 minutes. In all groups and at each lipopolysaccharide dosage, mediators peaked in this sequence: TxB2 and tnf, followed by PGF1α, then il-1β. Neither dose nor method of administration affected the sequence of mediator release. The magnitude of eicosanoid reponse to endotoxin was dose-dependent. During induced endotoxemia, duration and/or magnitude of mediator response reflected the dose of endotoxin administered, indicating that the outcome of endotoxemia, in neonatal calves, may be related to the amount of circulating endotoxin.
Effects of dietary protein conditioning on gentamicin-induced nephrotoxicosis in healthy male dogs
Authors: Grauer Gregory F. , Greco Deborah S. , Behrend Ellen N. , Fettman Martin J. , Jaenke Roger S. , Allen Timothy A.
Published: January 2024

Eighteen 6-month-old male Beagles with normal renal function were allotted at random to 3 groups of 6 dogs each. For 21 days, each group was fed a diet that was similar except for protein content (high protein, 27.3%; medium protein, 13.7%; and low protein, 9.4%). After the conditioning period, gentamicin was administered at a dosage of 10 mg/kg of body weight, IM, every 8 hours for 8 days, and the respective diet was continued. Clearance of endogenous creatinine, 24-hour urinary excretion of protein and enzymes (γ-glutamyltransferase, and N-acetyl- β-d-glucosaminidase, and fractional clearance of sodium and potassium (%) were determined before and after dietary protein conditioning and on days 2, 4, 6, and 8 of gentamicin administration. Additionally, trough serum gentamicin concentration was determined on days 2, 4, 6, and 8 of gentamicin administration. At the end of the study, all dogs were euthanatized; renal histologic features were graded, using a continuous ranking scale, and renal cortical gentamicin concentrations were measured. Data were ranked and analyzed, using a nonparametric equivalent of a two-way anova; P < 0.05 was considered significant.

After the dietary conditioning period (prior to gentamicin), dogs fed the high-protein diet had higher endogenous creatinine clearance and urinary excretion of protein, compared with dogs fed the low-protein diet. Differences existed among groups after 8 days of gentamicin administration. Dogs fed the high-protein diet had higher creatinine clearance, lower serum creatinine concentration, lower fractional clearance of sodium, lower urinary excretion of N-acetyl-β-d-glucosaminidase and lower trough serum gentamicin concentration, compared with dogs fed the medium- and low-protein diets. Dogs fed the high-protein diet also had lower urinary excretion of protein and lower fractional clearance of potassium, compared with dogs fed the low-protein diet. There was no difference in urinary excretion of γ-gluta-myltransferase among groups on day 8 of the study. Proximal tubular necrosis was more severe in dogs fed the medium-protein diet, compared with dogs fed the high-protein diet; however, there were no differences in renal cortical gentamicin concentrations among groups. In conclusion, feeding the high-protein diet prior to and during gentamicin administration reduced nephrotoxicosis in these dogs.
Effect of building ventilation design on environment and performance of turkeys
Authors: DeBey M. C. , Trampel D. W. , Richard J. L. , Bundy D. S. , Hoffman L. J. , Meyer V. M. , Cox D. F.
Published: January 2024

Environmental variables in 10 commercial turkey confinement buildings, representing 2 natural ventilation designs, were measured during summer and the following winter. Sliding doors spaced at intervals along the walls of 5 of the buildings provided about 35% opening, and continuous wall curtains provided 60 to 80% opening in the other 5 buildings. Environmental variables assessed included airspeed; temperature; relative humidity; gases; particle number, size, and mass per cubic meter of air; and colonies of bacteria, yeasts, and other fungi per cubic meter of air. Colonies of yeasts and other fungi were quantitated in feed and litter. For most of the variables evaluated, significant differences were not attributable to building ventilation design; however, in winter, the total mass of particulate matter per cubic meter of air was higher in the curtain-type houses, compared with sliding door-type houses. Ammonia concentration in the air of sliding door-type houses progressively increased during summer and winter sampling periods. A significant effect of building ventilation design on turkey performance was not detected when using mortality, average daily gain, feed conversion, condemnations at slaughter, or average individual bird weight as measures of production.
Inadequate superoxide production by canine neutrophils in response to the combination of N-formyl-methionyl-leucyl-phenylalanine and cytochalasin B
Authors: Ing T. S. , Yu A. W. , Patel M. , Gupta V. , Khan M. A. , Agrawal A , Patel P.
Published: January 2024

The formylated peptide, N-formyl-methionylleucyl-phenylalanine, at concentration of 0.22 μM, failed to stimulate canine neutrophils to produce adequate amounts of superoxide. Furthermore, addition of cytochalasin B did not augment superoxide generation appreciably.
Ultrasonography of the reticulum in cows
Authors: Braun Ueli , Götz Manfred
Published: January 2024

The reticulum and adjacent organs were examined ultrasonographically in 51 cows by use of a 3.5- MHz linear transducer applied to the ventral aspect of the thorax over the sixth and seventh intercostal spaces. Examination included assessment of the contour of the reticulum, of reticular contractions, and of the organs adjacent to the reticulum.

The normal reticulum appeared as a half-moon shaped structure with a smooth contour; it contracted at regular intervals and was situated immediately adjacent to the diaphragm and ventral portion of the abdominal wall when relaxed. Contents of the reticulum could not normally be imaged because of its partly gaseous composition. The ruminoreticular groove, craniodorsal blind sac of the rumen, and the ventral sac of the rumen were observed caudally. The distal aspect of the spleen and parts of the omasum, abomasum, and liver could be imaged.

Reticular motility was characterized by a biphasic contraction pattern. Four biphasic reticular contractions usually were observed during a 4-minute period. During the first (incomplete) contraction, the reticulum contracted by a mean of 7.2 ± 2.30 cm. There was then low-grade, incomplete relaxation of the reticulum, followed immediately by the second reticular contraction, during which the reticulum usually disappeared from the 17.5-cm-deep screen. The reticulum then reappeared in its normal position. The first reticular contraction lasted a mean of 2.6 ± 0.33 seconds and the second contraction lasted 3.9 ± 0.55 seconds. The mean interval between 2 biphasic contractions was 44.9 ± 10.53 seconds. The speed of the first reticular contraction was 5.4 ± 1.32 cm/s. Ultrasonography was useful for assessing the contour and motility of the reticulum.
Quantitative comparison of the stress response of striped bass (Morone saxatilis) and hybrid striped bass (Morone saxatilis × Morone chrysops and Morone saxatilis × Morone americana)
Authors: Noga E. J. , Kerby J. H. , King W. , Aucoin D. P. , Giesbrecht F.
Published: January 2024

Striped bass (Morone saxatilis) exposed to a standardized confinement stress had markedly different clinical and endocrinologic responses, compared with hybrid striped bass exposed to the same stress. Plasma cortisol concentration increased at a faster rate and appeared to reach a higher value in striped bass than in hybrid bass. Mean plasma cortisol concentration was 742 ± 43 ng/ml in striped bass, compared with 490 ± 37 and 531 ± 40 ng/ml in striped bass × white perch (M americana) and striped bass × white bass (M chrysops) hybrids, respectively, after a 45-minute net confinement. Plasma cortisol concentration also remained significantly (P = 0.003) higher in striped bass for at least 48 hours after the net confinement. These hormonal differences were associated with a markedly lower survival and resistance to infection in striped bass, compared with the hybrids.
Effects of altered arterial carbon dioxide tension on quantitative electroencephalography in halothane-anesthetized dogs
Authors: Smith Lesley J , Greene Stephen A. , Moore Michael P. , Keegan Robert D.
Published: January 2024

Quantitative electroencephalography was assessed in 6 dogs anesthetized with 1.8% end-tidal halothane, under conditions of eucapnia, hypocapnia, and hypercapnia. Ventilation was controlled in each condition. Heart rate, arterial blood pressure, core body temperature, arterial pH, blood gas tensions, end-tidal CO2 tension, and end-tidal halothane concentration were monitored throughout the study. A 21-lead linked-ear montage was used for recording the eeg. Quantitative electroencephalographic data were stored on an optical disk for analysis at a later date. Values for absolute power of the eeg were determined for δ, θ, α, and β frequencies. Hypocapnia was achieved by hyperventilation. Hypercapnia was achieved by titration of 5% CO2 to the inspired gas mixture. Hypercapnia was associated with an increase in the absolute power of the δ band. Hypocapnia caused an increase in the absolute power of δ, θ, and α. frequencies. Quantitative electroencephalographic data appear to be altered by abnormalities in arterial carbon dioxide tension. Respiratory acidosis or alkalosis in halothane-anesthetized dogs may obscure or mimic electroencephalographic abnormalities caused by intracranial disease.
Age-related changes in skin color and histologic features of hairless descendants of Mexican Hairless dogs
Authors: Kimura T. , Doi K.
Published: January 2024

Age-related changes in skin color and histologic features of hairless descendants of Mexican Hairless dogs were investigated and compared with those of haired descendants of Mexican Hairless dogs and Beagles. According to age, dogs studied were allotted to 4 groups: 0 to 2 weeks, 4 to 5 months, 1 to 1.5 years, and 3 to 4 years old. Skin color, histologic features, and numbers of dihydroxyphenylalanine (dopa)-positive melanocytes were examined. The luminance values measured, using a spectrophotometer, decreased with advancing age up to 1.5 years, but they increased again at 3 to 4 years in hairless dogs. The number of dopa-positive melanocytes in hairless dogs decreased with advancing age, whereas there were no dopa-positive melanocytes in haired dogs and Beagles. Histologically, the epidermis of newborn hairless pups was thick. The border between the epidermis and dermis was wavy, and epidermal ingrowths were found projecting into the dermis. As hairless dogs grew older, the epidermis became thinner and flatter. Although numbers of hair follicles and sebaceous and apocrine sweat glands were apparently fewer in hairless dogs than in haired dogs and Beagles, these structures were detected at least up to 4 years of age. On the other hand, haired dogs and Beagles had a thin epidermis at birth and aging had little effect on their epidermal structures. The dermis of hairless dogs contained fewer mast cells than did that of haired dogs and Beagles.
Influence of estrogen on antibacterial and immunoglobulin secretory activities of uterine fluids from ovariectomized mares
Authors: Johnson Jacqueline U. , Oxender Wayne D. , Berkhoff Herman A.
Published: January 2024

Effect of estrogen (E2) and progesterone (P4) on uterine antibacterial activity and immunoglobulin concentrations in mares was studied. In 2 in vitro experiments, 6 mixed-breed mares were ovariectomized, and uterine fluid and blood serum were analyzed. Antibacterial assay methods were used to determine inhibitory effects on Streptococcus zooepidemicus of uterine fluid samples collected on days 3, 5, and 8, and serum obtained on day 8 of treatment. Single radial immunodiffusion methods were used to quantify amounts of IgA and IgG in uterine fluid and serum on days 3, 5, 8, and 14 of treatment. Neither E2 nor P4 increased activity of serum and uterine fluid against S zooepidemicus. Numbers of colony-forming units per milliliter of bacteria were significantly (P < 0.01) lower in control Hanks’ balanced salt solution with 1.0% gelatin (hbssg) than in uterine fluids. Bacterial numbers were significantly (50%) greater in uterine fluids and serum than in hbssg controls for both treatments. Both fluids, especially serum, supported significantly (P < 0.01) more growth of S zooepidemicus than did hbssg when incubated for 0, 2, and 4 hours. These findings are in contrast to previous reports of antibacterial activity in the uterus of sexually intact mares undergoing an estrous cycle: great reduction of bacterial count in uterine fluid from mares in diestrus, and significant increases in bacterial numbers in uterine fluid or serum from mares in estrus. Treatment comparisons between serum and uterine fluid IgA and IgG concentrations were not significantly different, although overall IgA concentration in the uterus was higher than concentration in serum. The IgG concentration in uterine fluid was higher in P4- than E2-treated mares. However, IgG concentration was significantly (P < 0.01) higher in uterine fluid on day 8 in P4-treated mares than on day 3 or 5. Results of this study indicate that neither immunoglobulin concentration nor hormone treatment has a direct effect on streptocidal activity.
Effects of dietary supplementation of fructo-oligosaccharides on small intestinal bacterial overgrowth in dogs
Authors: Willard M. D. , Simpson R. B. , Delles E. K. , Cohen N. D. , Fossum T. W. , Kolp D. , Reinhart G.
Published: January 2024

Sixteen IgA-deficient German Shepherd Dogs with small intestinal bacterial overgrowth were randomized into 2 groups. One group was fed a chicken-based kibble diet; the other was fed the same diet, but with 1% fructo-oligosaccharides supplemented at the expense of cornstarch. After being exposed to the diets for 46 to 51 days, the group that ate the supplemented diet had significantly (P = 0.04) fewer aerobic/facultative anaerobic bacterial colony-forming units in fluid from the duodenum/proximal part of the jejunum, as well as in the duodenal mucosa. We could not detect significant differences in the species of bacteria found in the intestine of these 2 groups of dogs. We conclude that at least some dietary carbohydrates can affect small intestinal bacterial populations in dogs with small intestinal bacterial overgrowth.
Albumin quotient, IgG concentration, and IgG index determinations in cerebrospinal fluid of neonatal foals
Authors: Andrews Frank M. , Geiser Dennis R. , Sommardahl Carla S. , Green Eleanor M. , Provenza Melanie
Published: January 2024

Total protein (tp), albumin, and IgG concentrations were measured in csf from the atlanto-occipital (ao) and lumbosacral (ls) sites and in serum of 15 clinically normal neonatal foals ≤ 10 days old (mean, 7.0 days). The albumin quotient (aq; csf albumin/serum albumin × 100) and IgG index ([csf IgG/serum IgG] × [serum albumin/csf albumin]), indicators of blood-brain barrier permeability and intrathecal IgG production, respectively, were then calculated.

Mean ± sd values obtained from the foals of this study were: serum albumin, 2,900 ± 240 mg/dl; serum IgG, 1,325 ± 686 mg/dl; ao csf total protein (tp), 82.8 ± 19.2 mg/dl; ls csf tp, 83.6 ± 16.1 mg/dl; ao csf albumin, 52.0 ± 8.6 mg/dl; ls csf albumin, 53.8 ± 15.7 mg/dl; ao csf IgG, 10.2 ± 5.5 mg/dl; ls csf IgG, 9.9 ± 5.7 mg/dl; ao aq, 1.86 ± 0.29; ls aq, 1.85 ± 0.51, ao IgG index, 0.52 ± 0.28; and ls IgG index, 0.48 ± 0.27. Significant difference between values for the ao and ls sites was not found. A csf albumin concentration > 85.2 mg/dl or aq > 2.4, as determined by mean ± 2 sd, may indicate increased blood-brain barrier permeability. An IgG index value >1.0 may indicate intrathecal IgG production.

Values obtained for foals of this study should serve as baseline for comparison in the evaluation of blood-brain barrier permeability and intrathecal IgG production in neonatal foals with neurologic disease.
Cerebrospinal fluid variables in clinically normal foals from birth to 42 days of age
Authors: Furr Martin O. , Bender Holly
Published: January 2024

To determine the effects of age on each analyte, csf variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential wbc counts, rbc count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of age in 4 foals. Each foal was tested only once, to avoid any effects of csf sample collection on subsequent analysis. Regression analysis confirmed age-related effects on csf glucose, protein, and magnesium concentrations, but did not indicate an effect of age on csf sodium and potassium concentrations or cell counts. Results indicate that csf glucose concentration decreases with age; foals < 2 days old had the highest csf glucose values, 98.8 ± 12.0 mg/dl (mean ± 1 sd). In foals 10 to 14 days old, csf glucose concentration was 67.3 ± 12.0 mg/dl, was 65.3 ± 4.5 mg/dl in foals 21 to 22 days old, was 70.0 ± 5.4 mg/dl in foals 31 to 42 days old, and was 51.1 ± 2.5 mg/dl in adults. Protein values in csf also decreased with age: 109.0 ± 9.7 mg/dl in foals <2 days old, 81.0 ± 22.8 mg/dl in foals 10 to 14 days old, 60.5 ± 22.4 mg/dl in foals 21 to 22 days old, and 58.5 ± 17.0 mg/dl in foals 31 to 42 days old. The csf protein concentration was 60.3 ± 10.8 mg/dl in adult horses. Magnesium concentration in csf increased slightly with age, then decreased after 22 days of life. In foals < 2 days old, the value was 2.43 ± 0.16 mg/dl. Values in older foals and horses were: 2.51 ± 0.08 mg/dl in foals 10 to 14 days old, 2.65 ± 0.05 mg/dl in 21- to 22-day-old foals, 2.55 ± 0.05 mg/dl in 31- to 42-day-old foals, and 2.35 ± 0.09 mg/dl in adult horses.

Mean csf sodium and potassium concentrations were 151.7 ± 3.7 mmol/L and 3.14 ± 0.54 mmol/L, respectively, for all ages. There was no effect of age on these analytes. Values for csf enzymes were considered invalid for the assay technique used and were not further analyzed.
Effect of mimicking prepartum concentration of estradiol-17β on the inflammatory response to endotoxin in gilts
Authors: Magnusson Ulf , Holst Henrik , Kindahl Hans , Karlsson Åsa
Published: January 2024

The effect of mimicking prepartum concentration of estradiol-17β on the inflammatory response to endotoxin in gilts was studied. The study was performed in a split-litter design and comprised 5 pairs of littermates. A catheter was inserted into the jugular vein 2 days prior to the start of the study. In each pair, 1 littermate was treated im with 2.5 mg of estradiol-17β/75 kg of body weight, and the other littermate was given peanut oil im as a control. The day after treatment, all gilts were challenge-exposed with a Salmonella typhimurium-derived endotoxin (1 µg/kg, iv) and the inflammatory response to challenge exposure was monitored. There was no effect of estradiol treatment on the transient clinical signs of endotoxemia or on the increase in rectal temperature. The increase in blood concentrations of prostaglandin F2α metabolite and cortisol after endotoxin challenge exposure was not affected by estradiol. Decrease in number of circulating blood mononuclear cells and polymorphonuclear leukocytes was not changed by estradiol treatment. Taken together, mimicking prepartum concentration of estradiol did not affect either the magnitude or the kinetics of the inflammatory response to endotoxin in gilts. Relevance of these findings to development of endotoxinmediated diseases, such as the postpartum agalactia syndrome, needs further study.
Cardiorespiratory effects of glycopyrrolate-butorphanol-xylazine combination, with and without nasal administration of oxygen in dogs
Authors: Jacobson John D. , McGrath Charles J. , Ko Jeff C. H. , Smith Eric P.
Published: January 2024

Cardiopulmonary consequences of iv administered glycopyrrolate (0.01 mg/kg of body weight), followed in 11 ± 2 minutes by butorphanol (0.2 mg/ kg) and xylazine (0.5 mg/kg), were evaluated in 6 dogs, with and without nasal administration of oxygen (100 ml/kg/min). Glycopyrrolate caused significant (P < 0.05) increases in heart rate and cardiac index and significant (P < 0.05) decreases in stroke index.

Subsequent administration of butorphanol and xylazine was associated with significant (P < 0.05) increases in systemic vascular resistance, mean arterial blood pressure, mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, PaCO2, venous admixture, oxygen extraction ratio, and hemoglobin concentration. It caused significant (P < 0.05) decreases in cardiac index, stroke index, breathing rate, minute volume index, oxygen delivery, and oxygen consumption. Mean arterial blood pressure, pulmonary vascular resistance, tidal volume index, and minute volume index were significantly (P < 0.05) higher when dogs were breathing room air. The arterial and venous PO2 and PCO2, and venous oxygen content were significantly (P < 0.05) higher, and the arterial and venous pH, and oxygen consumption were significantly (P < 0.05) lower when oxygen was administered. Pulsus alternans and S-T segment depression were observed in dogs of both groups. Ventricular premature contractions were observed in 1 dog breathing room air.

All dogs were intubated briefly 15 minutes after administration of butorphanol and xylazine. Time to first spontaneous movement was 45 minutes. All dogs remained in lateral recumbency without physical restraint for 60 minutes.
Dual-energy X-ray absorptiometry of canine femurs with and without fracture fixation devices
Authors: Markel Mark D. , Bogdanske John J.
Published: January 2024

The effect of 5 fracture fixation methods on bone mineral density (bmd) measurement of femurs, using dual-energy X-ray absorptiometry (dxa) was determined in a canine model. Six regions of interest were measured, including the entire femur, the diaphysis of the femur, and small regions centered over the middiaphysis of the bone (lateral middiaphyseal cortex, medial middiaphyseal cortex, middiaphyseal medullary canal, and total middiaphysis). Eight unpaired femurs were collected and scanned by use of dxa before (5 separate scans/femur) and after (5 separate scans/femur) fixation by use of 1 of 5 fixation methods. These fixation methods included: intramedullary (im) nail; im nail and cerclage wires; im nail and external skeletal fixation; locked im nail; and a dynamic compression plate (dcp). All implants were made of stainless steel. The im nail fixation devices caused significant decreases in the dxa measurement of bmd in the small regions of interest, compared with femurs without fixation devices (mean decrease, 37.3%; P < 0.05). The locked nail caused similar, but larger, decreases in the dxa measurement of bmd, compared with the im nail fixation methods (P < 0.05). Plate fixation caused a small, but significant (P < 0.05), decrease (2.8%) in the dxa measurement of bmd in the large regions of interest, but when all regions were averaged, it did not cause significant change in this measurement, compared with femurs without fixation devices. Plate fixation caused a large change in the dxa measurement of bmd in 1 region only, in the lateral cortical bone under the plate where the dxa measurement of bmd was increased 13.3% over that in femurs without fixation devices (P < 0.05). In femurs without fixation devices, the precision error ranged from 0.5% for large regions of interest to 2.4% for small regions of interest. None of the fixation methods altered the precision error of large regions of interest (P > 0.05). In contrast, the precision errors of the small regions of interest were increased by the im fixation methods and the locked im nail. When all regions were combined, im fixation methods caused significant (P < 0.05) increase in the precision error, compared with femurs without fixation devices (mean increase, 157%; range, 121 to 193%). Plate fixation did not change the precision error of any region of interest, compared with femurs without fixation devices (P > 0.05; power = 0.8 at Δ = 64%).
Examination of the activities of 43 chemotherapeutic agents against Neospora caninum tachyzoites in cultured cells
Authors: Lindsay David S. , Rippey Natasha S. , Cole Rebecca A. , Parsons Lisa C. , Dubey J. P. , Tidwell Richard R. , Blagburn Byron L.
Published: January 2024

Neospora caninum causes serious disease in dogs, and it, or a similar parasite, is a major cause of abortion in cattle. Little is known about the susceptibility of this protozoan to antimicrobial agents. We studied several antimicrobial agents to determine which classes might have activity against this parasite. We also determined whether activity of such agents was coccidiocidal or coccidiostatic. A 2-day of treatment, monoclonal antibody-based enzyme immunoassay and a 5-day of treatment, cell culture flask (ccf), lesion-based assay were developed to examine the ability of test agents to inhibit tachyzoite multiplication. Seven sulfonamides were examined, with the following activities observed: sulfathiazole ≥ sulfamethoxazole > sulfadiazine > sulfaquinoxaline ≥ sulfamethazine > sulfadimethoxine > sulfamerazine. Dapsone, a sulfone, had little activity. Six dihydrofolate reductase/thymidylate synthase inhibitors were examined, with the following activities observed: piritrexim > pyrimethamine > ormetoprim > trimethoprim = diaveridine > methotrexate. Six ionophorous antibiotics were examined; lasalocid, maduramicin, monensin, narasin, and salinomycin had equivalent activities, but alborixin was toxic for host cells at the lowest concentration examined. Three macrolide antibiotics—azithromycin, clarithromycin, and erythromycin—were examined and had equivalent activities. Two tetracycline antibiotics, doxycycline and minocycline, were examined and had equivalent activities. Three lincosamide antibiotics were examined, with the following activities observed: clindamycin hydrochloride > clindamycin phosphate > lincomycin hydrochloride. Pentamidine and 6 of its analogs were examined, and only hexamidine and 1,4-Di[4-(2-imidazolinyl)-2-methoxy-phenoxy]butane had activity. Eight miscellaneous antiprotozoal agents were examined for activity. Amprolium, metronidazole, paromomycin, and roxarsone had little activity. Arprinocid, diclazuril, nitrofurazone, and robenidine had good activity. Eleven agents were examined in both assays, whereas 32 agents were examined in the ccf assay only. The enzyme immunoassay and ccf assay provided similar results for agents that rapidly killed tachyzoites. However, agents that inhibited development, but were not rapidly fatal for tachyzoites, had better activity in the ccf assay. Of the classes of agents examined, the dihydrofolate reductase/thymidylate synthase inhibitors, 2 of the 6 pentamidine analogs, and the ionophores were coccidiocidal and the sulfonamides, macrolides, tetracyclines, and lincosamides were coccidiostatic. Of the miscellaneous agents examined, arprinocid, nitrofurazone, and robenidine were coccidiocidal and diclazuril was coccidiostatic.
Dexamethasone-induced haptoglobin release by calf liver parenchymal cells
Authors: Higuchi Hidetoshi , Katoh Norio , Miyamoto Toru , Uchida Eiji , Yuasa Akira , Takahashi Kiyoshi
Published: January 2024

Parenchymal cells were isolated from the liver of male calves, and monolayer cultures formed were treated with glucocorticoids to examine whether haptoglobin, appearance of which is associated with hepatic lipidosis (fatty liver) in cattle, is induced by steroid hormones. Without addition of dexamethasone, only trace amounts of haptoglobin were detected in culture medium. With addition of dexamethasone (10−12 to 10−4M), considerable amounts of haptoglobin were released into the medium. Maximal release was observed at concentrations of 10−8 to 10−6M dexamethasone. Haptoglobin release was similarly induced by Cortisol, although the effect was less potent than that of dexamethasone. Actinomycin D (a known protein synthesis inhibitor) dose-dependently reduced amounts of haptoglobin released in response to 10−8M dexamethasone. Dexamethazone also induced annexin I, which is known to be synthesized in response to glucocorticoids. Dexamethasone treatment resulted in reduced protein kinase C activity in the cell cytosol, which has been shown to be an early event in dexamethasone-treated cells. Other than glucocorticoids, estradiol induced haptoglobin release, whereas progesterone was less effective. The association of haptoglobin with hepatic lipidosis can be reasonably explained by the fact that haptoglobin production by the liver is induced by glucocorticoids and estradiol, and these steroid hormones are triggers for development of hepatic lipidosis in cattle.
Long-term fate and effects of exercise on sternal cartilage autografts used for repair of large osteochondral defects in horses
Authors: Howard R. D. , Mcllwraith C. W. , Trotter G. W. , Powers B. E. , McFadden P. R. , Harwood F. L. , Amiel D.
Published: January 2024

Bilateral osteochondral defects (10 mm2 × 3 mm deep) were created on the distal articular surface of the radial carpal bone of ten, 2- to 3-year-old horses. One defect of each horse was repaired, using a sternal cartilage autograft (treated), and the other was left untreated (control). The horses were exercised on a high-speed treadmill at incrementally increased speed and duration over the course of 12 months. Horses were evaluated arthroscopically at 6 to 7 weeks, and clinical examinations were conducted weekly at exercise. Twelve months after surgery, carpuses of each horse were radiographed and clinically examined prior to euthanasia. A gross pathologic evaluation of each joint was conducted, and samples were collected for histologic, histochemical, histomorphometric, and biochemical evaluation. Radio-graphically, the grafted joints had more extensive evidence of arthropathy, and clinically, 8 of the 10 horses were more lame in the grafted limb. On the basis of histomorphometry, the repair tissue of the grafted defects contained a greater median percentage of hyaline cartilage (45%) than that of control defects (4.5%), and the control defects contained a greater percentage of fibrocartilage (82%) than did grafted defects (28.5%). A greater median percentage of repair tissue stained with safranin-O in the grafted defects (24.5%) than in the control defects (3.5%). On gross pathologic and histologic evaluation, repair tissue of the control defects had better continuity and was more firmly attached to the subchondral bone than was repair tissue of the grafted defects. Repair tissue of the grafted defects had extensive fissure and flap formation. Histologically, subchondral bone reactivity and fibroplasia was extensive in grafted joints. Repair tissue of grafted defects had a greater percentage of type II collagen (mean ± SEM, 83.5 ± 2.95%) than did controls (mean, 79.4 ± 3.87%) that was not statistically significant. Hexosamine content was significantly higher (P < 0.05) in repair tissue of the grafted defect (mean, 28.9 ± 3.00 mg/g of dry weight) vs control (mean, 20.6 ± 1.85 mg/g of dry weight). On the basis of this experimental model, sternal cartilage autografts cannot be recommended at this time for repair of osteochondral defects in athletic horses.
Influence of age, breed, and stage of pregnancy on hepatic ultrasonographic findings in cows
Authors: Braun Ueli , Gerber David
Published: January 2024

Influence of age, breed, and stage of pregnancy on hepatic ultrasonographic findings of cows was determined. In addition, the relation between body weight, height at the withers, milk production, and the measurements determined via ultrasonography was investigated.

The liver of 186 cows was examined ultrasonographically. The cows comprised Swiss Braunvieh, Simmental, and Holstein breeds, and age ranged from 2.5 to 11.5 years. The ultrasonographic findings of the liver, gallbladder, caudal vena cava, and portal vein were described, and the position, size, thickness, and distal angle of the liver were determined. In addition, the position and diameter of the caudal vena cava and portal vein were determined. There was no significant difference between any of the variables determined and breed or age. Therefore, measurements for the 3 breeds and for the various ages were summarized into 1 group. There were significant correlations between body weight, milk production, and size and thickness of the liver.

In 3 pregnant cows, the liver was examined ultrasonographically 8 times during the course of pregnancy. Positive correlation was detected between stage of pregnancy and diameter of the caudal vena cava. There was a negative correlation between stage of pregnancy and diameter of the portal vein.

In 23 cows, the ultrasonographically determined measurements of the liver were compared with those determined at slaughter. Weight of the liver correlated well to thickness of the liver determined via ultrasonography.
Protection against enteric septicemia of catfish (Ictalurus punctatus) by immunization with the R-mutant, Escherichia coli (J5)
Authors: Tyler Jeff W. , Klesius Philip H.
Published: January 2024

The protective effects of immunization with the rough (R) mutant, Escherichia coli (J5), were evaluated in an experimental model of Edwardsiella ictaluri-induced enteric septicemia of catfish (Ictalurus punctatus). Groups of 18 to 25 fish were administered killed E coli (J5) with or without an aluminum hydroxide (alum) adjuvant by intraperitoneal (ip) or IM route. Vaccinated fish were experimentally infected with virulent Ed ictaluri. Fish were monitored to determine survival after Ed ictaluri infection. Fish that received E coli (J5) in alum IP had enhanced survival (92%), compared with fish given E coli (J5) IP only (54%, P < 0.05) or fish given saline solution IP (56%, P <0.05). Fish given E coli (J5) in alum IM had intermediate survival (77%), which did not differ significantly (P> 0.05) from survival of fish in the other 3 vaccination groups. Serologic responses to Ed ictaluri and E coli (J5) before and after immunization with Ecoli (J5) were determined, using whole-cell elisa. Serologic recognition of both whole cell antigens increased significantly (P< 0.10) in all groups; however, the most pronounced increase was observed in fish that received Ecoli (J5) in alum IP. These results indicate the IP administration of Ecoli (J5) in alum protects against enteric septicemia of catfish.