bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlled tests on activity of contemporary parasiticides on natural infections of helminths in lambs, with emphasis on strains of Haemonchus contortus isolated in 1955
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C. , Stamper S.
Published: January 2024

Ten controlled tests were done between 1972 and 1989, in lambs on pasture, evaluating activity of fenbendazole (fbz; 5 mg/kg of body weight), oxfendazole (ofz; 3.5 and 10 mg/kg), oxibendazole (obz; 10 mg/kg), pyrantel pamoate (prt; 25 mg of base/kg), and thiabendazole (tbz; 44 and 50 mg/kg) against natural infections of helminths, with emphasis on 2 strains (A and B) of Haemonchus contortus. Strain A was phenothiazine-susceptible and strain B was phenothiazine-resistant when isolated in 1955. For approximately 10 years prior to these tests, sheep infected with both strains had been treated periodically each year with several compounds, including thiabendazole, which was used many more times than the other drugs.

For this study, 4 (fbz, ofz, obz, and prt) of the 5 compounds were evaluated in either 1 or 2 controlled tests. The fifth compound, tbz, was used for 5 tests. Strain A H contortus was resistant to tbz for all years tested, but more susceptible to fbz, ofz, obz, and prt. Overall, strain B was susceptible to tbz (with a few exceptions), and also to fbz, ofz, obz (activity less on immature forms), and prt.

Other abomasal parasites (2 species of Ostertagia and 3 of Trichostrongylus) were found in low numbers, but removal overall was good for the compounds tested. Trichostrongylus axei, found in higher numbers than species of Ostertagia and other species of Trichostrongylus, were effectively removed by all compounds in most cases.

Activities of tbz and prt were also evaluated against several species of intestinal helminths, most of which were found in low numbers. Cooperia curticei were inconsistently removed by tbz, but activity of prt was effective. Both compounds were active on mature Nematodirus sparger, but tbz had variable activity on immature forms. Strongyloides papillosus were effectively removed by tbz. Other parasites found in lower numbers than the aforementioned 3 species were Capillaria spp, Trichuris spp, and Oesophagostomum columbianum; removal was variable for both drugs.
Immune response of cattle to Haemophilus somnus lipid A-protein conjugate vaccine and efficacy in a mouse abortion model
Authors: Inzana Thomas J. , Todd Jean
Published: January 2024

Immunogenicity of the lipid A component of Haemophilus somnus lipooligosaccharide in cattle and mice was examined after purification, detoxification, and covalent conjugation to a protein carrier. After 2 inoculations, a substantial antibody response was induced in most cattle to lipid A and the protein carrier. To determine whether antibodies to lipid A would be protective, 5 x 107 colonyforming units of H somnus strain 649 were administered IV to endotoxin-responsive (C3H/HeN) mice. In one study, 8 of 13 C3H/HeN mice aborted when inoculated. In contrast, abortion did not result when mice were inoculated with the same dose of an isolate of H somnus normally found in the prepuce or with the rough mutant Escherichia coli J5. In addition, endotoxin-nonresponsive (C3H/ HeJ) mice were significantly (P =0.03) more resistant to abortion by strain 649 than were C3H/HeN mice, but inoculated C3H/HeN mice were only slightly more resistant to H somnus abortion, compared with control mice. Although a large antibody response to lipid A was detected, there was no significant difference in the immunized group between mice that aborted and mice that delivered normally. Thus, lipooligosaccharide and other properties of virulent H somnus strains may contribute to abortion in mice.
Intradermal testing of horses with chronic obstructive pulmonary disease and recurrent urticaria
Authors: Evans Anne G. , Paradis Mary Rose , O’Callaghan Michael
Published: January 2024

Six horses with chronic obstructive pulmonary disease (copd) and 8 horses with recurrent urticaria were skin tested with 67 extracts from 58 allergens, including pollens, epidermals, cultivated farm plants, dusts, molds, and insects. Reactions were evaluated 3 times over a 24-hour period immediately after the injections. Results were compared with those obtained from 11 clinically normal horses. All horses had positive skin test reactions. Significant difference was evident between horses with copd and clinically normal horses for only 3.0% of the possible extract reactions, and between horses with urticaria and clinically normal horses for only 4.5% of the possible extract reactions. Horses with copd or urticaria had greater total percentage of allergen extract reactions than did clinically normal horses. Positive reactions were observed at all 3 evaluation periods, and late-onset reactions were not always preceded by positive reaction at earlier periods. All horses with copd or urticaria had at least 1 skin test reaction that exceeded the mean ± 2 SD, as calculated for each of the 67 extracts for the group of clinically normal horses.
Myocardial taurine concentrations in cats with cardiac disease and in healthy cats fed taurine-modified diets
Authors: Fox Philip R. , Sturman John A.
Published: January 2024

Myocardial taurine concentrations were measured in cats with cardiac disease and in healthy cats fed diets with various concentrations of taurine. Group 1 was composed of 26 cats with 3 categories of naturally developing cardiac disease: dilatative cardiomyopathy (group 1A), 10 cats; hypertrophic cardiomyopathy (group 1B), 9 cats; and volume overload (group 1C), 7 cats. These cats had been fed various commercial diets. Group 2 was composed of 40 healthy cats that had been fed diets varying in taurine concentration (0 to 1% taurine) for at least 2 years.

Mean myocardial taurine concentrations did not differ significantly between group-1 cats with dilatative cardiomyopathy and those with hypertrophic cardiomyopathy or volume overload. Cats in group 1A had a mean myocardial taurine concentration 3 times higher than healthy cats fed a taurine-free diet (P< 0.002). Mean myocardial taurine concentrations did not differ significantly between group-1A cats and healthy cats fed a diet containing 0.02% taurine; group-1A cats had significantly lower mean myocardial taurine concentrations than did healthy cats fed a synthetic diet containing 0.05 or 1.0% taurine (P < 0.001). Acute oral administration of taurine in 5 group-1A cats appeared to increase mean myocardial taurine concentrations, compared with similar cats not given taurine during treatment for cardiac failure. In group-2 cats, mean myocardial taurine concentrations increased directly with percentage of dietary taurine.
Response of colostrum-deprived cynomolgus monkeys to intragastric challenge exposure with simian rotavirus strain SA11
Authors: Petschow Bryon W. , Litov Richard E. , Young Lawrence J. T. , McGraw Thomas P.
Published: January 2024

The infectivity and pathogenic potential of a cell culture-adapted simian rotavirus was evaluated in colostrum-deprived newborn and infant cynomolgus macaques (Macaca fascicularis). Intragastric challenge exposure with the simian rotavirus strain SA11 on postpartum day 2 induced diarrhea in 5 of 5 colostrum-deprived newborn monkeys. Compared with sham-inoculated controls, 3 of the 5 inoculated monkeys also manifested reduced body weight gain during the initial 5 days after challenge exposure. Rotavirus was detected in feces of 3 challenge-exposed monkeys for up to 2 days after inoculation. Evaluation of antibody response after rotavirus inoculation was obscured by high but variable prechallenge-exposure serum titers of rotavirus-specific antibody. Preexisting serum titer of neutralizing antibody in newborn monkeys was not predictive of clinical response to inoculation with rotavirus SA11. Two 90-day-old infant monkeys with low serum neutralizing antibody titer did not have diarrhea, reduced weight gain, or antibody response after oral inoculation with rotavirus SA11. Results of these challenge-exposure studies in newborn cynomolgus monkeys were consistent with a heterologous host-rotavirus model and indicate that neonatal serum antibody of maternal origin may not be associated with resistance to rotavirus-induced disease.
Pharmacologic evaluation of factor XIIIa*-like enzyme activity in equine plasma as a potential therapeutic avenue for the inhibition of fibrinous tissue
Authors: Coyne C. P. , Smith Joseph E. , DeBowes Rick M.
Published: January 2024

Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, Xllla*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate.

Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency), solubility of transparent fibrin gels in concentrated urea solution, in conjunction with simultaneous depletion of native fibrinogen fractions, and production of fibrin monomer. Compounds acting primarily as anticoagulants were recognized by lack of plasma gel formation, but retaining high spectrophotometric transmittance and no detectable depletion of native fibrinogen fractions. Compounds failing to inhibit either thrombin-mediated fibrinogen-fibrin transformation (ie, coagulation) or coagulation factor-XIIIa*-like enzyme activity were recognized by opaque plasma gels caused by fibrin polymerization, low spectrophotometric transmittance values, and coinciding with depletion of native fibrinogen fractions.

Pharmaceuticals capable of exerting selective inhibition of coagulation factor-XIIIa*-like enzyme activity were further classified as competitive inhibitors of phase 1 (carbamide) or phase 2 (terminal amine) of the transglutamination process.
Concentrations of luteinizing hormone and follicle-stimulating hormone in the serum of sexually intact and neutered dogs
Authors: Olson Patricia N. , Mulnix John A. , Nett Terry M.
Published: January 2024

Concentrations of luteinizing hormone (lh) and follicle-stimulating hormone (fsh) were measured in serum samples obtained from 100 dogs. Groups (n = 25/group) consisted of sexually intact and ovariohysterectomized bitches and sexually intact and castrated male dogs. Mean (± sd) concentrations of lh in the serum of sexually intact and ovariohysterectomized bitches were 1.2 (± 0.9) and 28.7 (± 25.8) ng/ml, respectively. Mean concentrations of fsh in the serum of sexually intact and ovariohysterectomized bitches were 98 (± 49) and 1,219 (± 763) ng/ml, respectively. Mean concentrations of lh in the serum of sexually intact and castrated male dogs were 6.0 (± 5.2) and 17.1 (± 9.9) ng/ml, respectively. Mean concentrations of fsh in the serum of sexually intact and castrated male dogs were 89 (± 28) and 858 (± 674) ng/ml, respectively. In addition to history, physical examination results, and other laboratory values, the measurement of serum gonadotropin concentrations may aid in determining whether dogs have been neutered.
Selective measurement of lipoprotein lipase and hepatic triglyceride lipase in heparinized plasma from horses
Authors: Watson T. D. G. , Burns L. , Packard C. J. , Shepherd J.
Published: January 2024

Affinity chromatography on heparin sepharose was used to identify 2 lipolytic enzymes in heparinized plasma from horses. One enzyme was typical of hepatic triglyceride lipase (htgl), because it was resistant to inactivation by high concentrations of NaCl, and it did not require the addition of serum for activity. The other enzyme was identified as lipoprotein lipase (lpl), because of its inactivation at NaCl concentrations in excess of 0.2M, and its dependency on addition of serum as a source of apolipoprotein C-II activator. The enzymes were purified by 347- (htgl) and 442- (lpl) fold, with yields of 54 and 58%, respectively. The partially purified enzymes were used to design incubation conditions that gave optimal activities for each enzyme in vitro. A selective assay was then developed for direct measurement of lpl and htgl activities in heparinized plasma from horses. Analysis of htgl took advantage of the almost complete inactivition of lpl when serum cofactor was excluded from the assay at the NaCl concentration that gave optimal htgl activity. Prior incubation of heparinized plasma with sodium dodecyl sulfate to inhibit htgl was necessary for measurement of lpl, because htgl retained 67% of its activity at the NaCl concentration required for optimal lpl activity. Activity of each enzyme was measured in heparinized plasma from 12 Shetland ponies. The mean activity ± sd for lpl was 3.22 ± 1.04 μmol of fatty acids/ml of heparinized plasma/h (μmol of fa/ml/h). The mean activity for htgl was 4.9 ± 1.56 μmol of fa/ml/h. The performance of the assay was assessed by replicate analysis of pools of each enzyme with high and low activities. The intra-assay coefficient of variation ranged between 3.4 and 8.7% (n = 10), and the interassay coefficient of variation ranged between 5.2 and 10.7% (n = 7) for the same pools analyzed over 7 weeks.
Neutrophil activation associated with increased neutrophil acyloxyacyl hydrolase activity during inflammation in cattle
Authors: McDermott Colleen , Fenwick Brad
Published: January 2024

Acyloxyacyl hydrolase (aoah) is a lysosomal enzyme found in neutrophils and macrophages that acts to partially deacylate the lipid-A component of the endotoxin of gram-negative bacteria rendering it less toxic, yet maintaining much of its immunostimulatory potential. We have found that the activity of neutrophil aoah per cell increased during localized inflammation. The purpose of this study was to determine the mechanism(s) responsible for these increases in neutrophil aoah activity. Because changes in neutrophil maturity commonly are associated with inflammation, intravascular infusion of purified gram-negative bacterial lipopolysaccharide and sc injection of bovine recombinant granulocyte colony-stimulating factor was used to induce large numbers of circulating immature neutrophils. Immature neutrophils were found to have aoah activity equal to that of mature cells; however, when neutrophils were stimulated in vitro with known activators, aoah activity of activated cells was more than that of unstimulated cells. The increase in aoah activity was inversely related to prestimulation activity. Increases in aoah activity after neutrophil activation were not a result of de novo synthesis of the enzyme, because cycloheximide did not prevent activation-induced increases in activity.
Effects of a thromboxane synthetase inhibitor on established immune complex glomerulonephritis in dogs
Authors: Grauer Gregory F. , Frisbie David D. , Longhofer Susan L. , Cooley A. James
Published: January 2024

Twelve Beagles were inoculated with concanavalin A, and after a mean ninefold increase in antibody titer, 1 mg of concanavalin A was infused into each renal artery of each dog to induce in situ immune complex glomerulonephritis. Starting 4 weeks after renal arterial infusion, 6 dogs were treated orally 3 times daily with 30 mg of 3-methyl-2 (3 pyridyl)-1-indoleoctanoic acid (CGS 12970)/ kg of body weight, a thromboxane synthetase inhibitor, and 6 dogs (control group) received a gelatin capsule 3 times daily. Endogenous creatinine clearance and 24-hour urinary excretion of protein and thromboxane B2 were determined for each dog prior to renal arterial infusion, at the initiation of treatment and at 2, 4, 6, and 8 weeks after initiation of treatment. In addition, methyoxy-3H inulin clearance was determined at initiation of treatment and 4 and 8 weeks later. Renal specimens were examined histologically at the initiation of treatment and 4 and 8 weeks later. Glomerular mononuclear profiles/μm3 were determined from at least 10 equatorially sectioned glomeruli from each dog. Paired t tests were used to compare mean values at the various time points to the respective mean baseline value and 2-sample t tests were used to evaluate differences between treatment groups.

At the start of treatment (4 weeks after renal arterial infusion of concanavalin A), histologic evaluation of renal specimens revealed glomerular epithelial crescent formation, mononuclear cell proliferation, and infiltration of neutrophils. Mononuclear cell profiles and urinary excretion of protein and thromboxane B2 were significantly increased, but endogenous creatinine clearance values were unchanged. Treatment with CGS 12970 did not affect endogenous creatinine clearance, methyoxy-3H inulin clearance, or glomeruli, however, CGS 12970 treatment significantly decreased urinary excretion of protein and thromboxane B2 when compared with values in the control group. These findings suggested that thromboxane has a role in the pathogenesis of established glomerulonephritis and that thromboxane synthetase inhibition treatment may be beneficial in dogs with established glomerulonephritis.
Increased numbers of duodenal mucosal mast cells in turkeys inoculated with hemorrhagic enteritis virus
Authors: Opengart Kenneth , Eyre Peter , Domermuth Charles H.
Published: January 2024

The relation between average duodenal mast cell count, duodenal mucosal mast cell numbers, duodenal connective tissue mast cell numbers, circulating basophil numbers, heterophil-to-lymphocyte ratio, and lesion score were studied to gain an understanding of the events that may lead to intestinal lesion formation associated with hemorrhagic enteritis virus (hev) infection. Changes in vascular permeability in the duodenum in birds inoculated with hev were examined, using colloidal carbon and ferritin as vascular markers. Turkeys inoculated with hev had significantly (P < 0.05) higher duodenal mast cell counts than did noninfected controls. Birds inoculated with hev had significantly (P < 0.05) more mucosal mast cells than did phosphate-buffered saline solution-inoculated birds. Connective tissue mast cell and basophil numbers were unaffected by viral inoculation. Thermal stress did not have significant effect on lesion severity, but did increase number of birds that developed the characteristic intestinal lesions. The heterophil-to-lymphocyte ratio was significantly (P < 0.05) higher in hev-inoculated birds, compared with phosphate-buffered saline solution-inoculated controls. Increase in vascular permeability was only detected in hev-inoculated birds with intestinal lesions. Results indicate that mast cells, and the vasoactive mediators contained within mast cells, may be important in the early manifestation of hev infection. They also provide a possible mechanism through which biochemical and physiologic changes characteristic of hev infection can occur.
Immunologic responses in healthy random-source cats fed N,N-dimethylglycine-supplemented diets
Authors: Weiss Richard C.
Published: January 2024

The immunomodulatory capacities of N,N-dimethylglycine (dmg) were examined in random-source cats. Blood mononuclear leukocytes of healthy adult cats that had negative results to tests for FeLV and feline immunodeficiency virus were exposed in vitro to various concentrations of dmg (10 to 1,000 μg/ml) and were evaluated for proliferative responses to T- or B-cell phytomitogens. Although increased, mean lymphocyte blastogenic responses to phytolectins in dmg-treated cultures did not differ significantly from responses of untreated cultures. For in vivo studies, cats were given a solution containing either 100 mg of dmg or a control solution without dmg orally at 8 am and 6 pm for 40 consecutive days. On posttreatment day 24 and 25, mean blastogenic responses to phytolectins in dmg-treated and control cats inoculated 10 days earlier with an inactivated feline virus vaccine were similar. Cats given dmg and inoculated twice in a 3-week interval with a commercial vaccine containing inactivated feline herpesvirus-1 and feline calicivirus had significantly (P = 0.045) lower virus neutralizing serum antibody titers against feline herpesvirus-1, compared with titers of control cats, whereas feline calicivirus titers were similar in both groups. On day 25, mean serum interferon activity, induced after iv inoculation of Newcastle disease virus, was significantly (P = 0.021) lower in the dmg-treated cats.

Results of this study of dmg in healthy cats failed to demonstrate enhancement of either specific or nonspecific immunity.
Pharmacokinetic study of danofloxacin in cattle and swine
Authors: Mann D. D. , Frame G. M.
Published: January 2024

Pharmacokinetic values of a new quinolone antimicrobial, danofloxacin, were studied in cattle and swine. Plasma concentration was detected within 15 minutes after im administration, peaked by 1 hour, and subsequently decreased, with half-life of 2.9 and 6.8 hours for cattle and swine, respectively. In swine, danofloxacin was absorbed, whether orally administered by gavage, in feed, or in drinking water. Danofloxacin concentrated in lung tissue at 4 to 7 times the plasma concentration. Lung tissue concentration exceeded the minimal inhibitory concentrations for im90portant respiratory tract pathogens for extended periods after administration of the drug by any of the routes studied. The major routes of excretion were in urine and bile.
Evaluation of sulbactam plus ampicillin for treatment of experimentally induced Klebsiella pneumoniae lung infection in foals
Authors: Hoffman Andrew M. , Viel Laurent , Muckle Catherine A. , Yager Julie S. , Staempfli Henry R.
Published: January 2024

Efficacy of sulbactam, a β-lactamase inhibitor, in combination with ampicillin, was evaluated for treatment of experimentally induced pneumonia caused by β-lactam-resistant Klebsiella pneumoniae. Infection was experimentally induced in 18 healthy weanling foals that were randomly allocated to 3 treatment groups: sulbactam plus ampicillin (s/a, 3.3 and 6.6 mg/kg of body weight, respectively), ampicillin (6.6 mg/kg), or vehicle only. Foals were treated daily for 7 days; the observer was unaware of treatment status. Compared with ampicillin and vehicle, treatment with s/a resulted in a statistically significant (P < 0.05) decrease in severity of pneumonia, with regard to bronchoalveolar lavage cytologic findings (decreased total cell and neutrophil numbers, and increased lymphocyte numbers) and extent of macroscopic lesions in lung tissue of the noninoculated regions. Marked trends toward improvement of s/a-treated foals were observed for quantitative results of bacteriologic culture of bronchoalveolar lavage fluid samples (P < 0.07), macroscopic pathologic features of the whole lung (P < 0.1), and histopathologic variables (P < 0.07), compared with ampicillin- and vehicle-treated foals. Treatment effects were not observed for radiographic, hematologic, and blood gas abnormalities that resulted from infection. In conclusion, the combination of sulbactam plus ampicillin was found to have synergistic effects in vivo, to reduce the extent and severity of experimentally induced gram-negative lung infection in foals.
Diagnostic implications of detection of proteinase K-resistant protein in spleen, lymph nodes, and brain of sheep
Authors: Race Richard , Ernst Darwin , Jenny Allen , Taylor William , Sutton Diane , Caughey Byron
Published: January 2024

Brain, spleen, and selected lymph nodes from sheep with clinical signs of scrapie were analyzed for presence of proteinase K-resistant protein (PrP-res). Diagnosis of scrapie on the basis of detection of PrP-res was compared with diagnosis on the basis of histologic evaluation of the brain from clinically affected or exposed sheep. Proteinase K-resistant protein was found in every brain that was histologically positive for scrapie, and in addition, was found in the brain of several clinically positive sheep that were not diagnosed as scrapie-positive by histologic evaluation. Proteinase K-resistant protein was also found in 87% of the spleens and lymph nodes from sheep that had PrP-res detected in brain homogenates. Therefore, analysis of sheep brain, spleen, or lymph nodes for PrP-res provided a diagnostic approach that was superior to histologic examination alone for detection of naturally scrapie agent-infected sheep.
Plasma concentrations of luteinizing hormone and adrenocorticotropic hormone in blood collected during the luteal and follicular phases of the estrous cycle in cows
Authors: Hegstad Rebecca L. , Johnston Shirley D. , Pasternak Donna M. , Seguin Bradley E. , Wheaton Jon E.
Published: January 2024

Luteinizing hormone (lh) and acth concentrations were measured in plasma from 7 cows to determine whether acth secretion changes with the phase of the estrous cycle, and to determine whether any acth peaks are associated with lh peaks. Blood was collected every 5 minutes for 190 minutes during the luteal and follicular phases of the estrous cycle. Radioimmunoassays were used to measure acth and lh in plasma. Mean concentration of acth in all cows did not differ significantly between luteal (35.1 ± 8.0 pg/ml) and follicular (37.5 ± 9.4 pg/ml) phases of the estrous cycle. Mean concentration of luteal-phase lh of all cows (2.0 ± 1.1 ng/ml) was significantly (P < 0.01) lower than mean concentration of follicular-phase lh (5.4 ± 1.6 ng/ml). Frequency of peaks in acth concentration was low during the sampling period. Mean number of luteal-phase acth peaks (0.29 ± 0.49) was not significantly different from that of follicular-phase samples (0.43 ± 0.53). Unlike acth, mean frequency of lh peaks was significantly (P < 0.05) higher in plasma from cows in the follicular phase of the estrous cycle (2.9 ± 0.7), compared with that from cows in the luteal phase (0.29 ± 0.49).
Microvascular circulation of the small intestine in horses
Authors: Dart Andrew J. , Snyder Jack R. , Julian Dolores , Hinds Dave M.
Published: January 2024

The microvascular anatomic features of the small intestine was described by correlating results of microangiography, light microscopy, gross studies, and scanning electron microscopy of vascular replicas in 14 horses. After heparinization, the horses were euthanatized, a length of jejunum was transected, and blood was flushed free of the circulation, using isotonic NaCl solution. In six horses, the circulatory system was perfused with a modified radiopaque medium and evaluated radiographically. These sections were then evaluated by standard histologic methods. Sections from 8 horses were perfused with 1 of 2 types of plastics and studied grossly or by scanning electron microscopy.

The margined arterial arcade gives rise to vessels that enter the jejunum at the mesenteric angle. These vessels penetrated either directly, by branching and entering on both sides of the mesenteric angle, or supplying only 1 side of the mesenteric angle. All these vessels continued in the submucosa branching extensively, forming a submucosal plexus. This submucosal plexus supplied the tunica muscularis, tunica serosa, and the mucosa. Vessels within the 2 muscle layers ran parallel to the muscle fibers and, consequently, perpendicular to each other. The arterial supply to the mucosa penetrated the muscularis mucosae and branched to supply 2 mucosal capillary networks. An eccentrically placed arteriole penetrated the base of the villus and spiralled to the tip where it "fountained" into a mesh-like capillary network, which descended peripherally in the villus to drain via 1 to 3, but most commonly 2 venules. Venules from adjacent villi united and drained via the submucosal veins. The second capillary network supplied the glands of the intestinal crypts. The capillary network around adjacent glands anastomosed just below the luminal surface. There were connections between this network and the base of the villus capillary network. Drainage of the glandular capillary network was through these connections and through the villus venules. There was no evidence of arterovenous anastomoses.
Efficacy of a chewable formulation of ivermectin against a mixed infection of Ancylostoma braziliense and Ancylostoma tubaeforme in cats
Authors: Nolan Thomas J. , Niamatali Susan , Bhopale Veena , Longhofer Susan L. , Schad Gerhard A.
Published: January 2024

The efficacy of a beef-based, chewable formulation of ivermectin against a mixed infection of Ancylostoma braziliense and A tubaeforme was determined in cats. Ivermectin administered orally at approximately 24 μg/kg of body weight was 92.8% effective against adult A braziliense and 90.7% effective against adult A tubaeforme. The number of eggs per gram of feces had decreased 98.1% by 7 days after treatment. Clinical signs of hookworm disease also decreased after treatment. Location of adult parasites within the small intestine, percentage of infecting larvae that developed to the adult stage, and egg size in cats with infections of A braziliense and A tubaeforme were similar to those reported for cats with separate infections of either species.
Effect of xylazine on cerebrospinal fluid pressure in conscious horses
Authors: Moore Rustin M. , Trims Cynthia M.
Published: January 2024

Lumbosacral csf pressure was measured in 6 horses via a catheter inserted through the lumbosacral space. Heart rate, facial artery pressure, central venous pressure, and csf pressure were measured before iv injection of a saline solution control, for 15 minutes after saline solution injection, and for 60 minutes after the iv injection of 1.1 mg of xylazine/kg of body weight. Arterial pH and blood gases were analyzed before saline solution injection, 15 minutes after saline solution injection, and at 15, 30, and 60 minutes after xylazine injection. Constant craniocervical posture was maintained during sedation. Lumbosacral csf pressure was significantly decreased for 15 minutes after xylazine injection. Diastolic arterial pressure was significantly increased 4 minutes after xylazine administration and diastolic and mean arterial pressure were increased at 6 and 8 minutes after xylazine administration. Small increases in systolic arterial blood pressure and central venous pressure, and a small decrease in heart rate were observed. There were no significant differences in the arterial blood gas values. It was concluded that iv injection of xylazine causes a decrease in intracranial pressure in healthy conscious horses. The effects may be different in horses with neurologic disease or cerebral trauma.
Evaluation of the proximal portion of the femur as an autogenous cancellous bone donor site in dogs
Authors: Trevor P. B. , Smith M. M. , Stevenson S. , Carrig C. B.
Published: January 2024

The proximal portion of the femur was evaluated as a source of autogenous cancellous bone in dogs. Bilateral oval cortical defects were created in the lateral subtrochanteric area of the femur in 16 dogs. Cancellous bone was removed and the weight recorded. Cancellous bone was similarly harvested from the proximal portion of the humerus in 7 of these dogs. Subtrochanteric femoral defects in 11 dogs were randomly assigned to receive cancellous bone graft obtained from the femur (n = 4) or the humerus (n = 7). Subtrochanteric defects in 5 dogs were not grafted. Radiographic assessment of subtrochanteric defects was performed at 4-week intervals, and histologic assessment at 4, 8, 16, and 24 weeks after surgery. Non-grafted donor sites healed by ingrowth of trabecular bone during the first 12 weeks after surgery. By week 24, the lateral cortical wall had reformed, but remodeling was incomplete. Donor sites grafted with cancellous bone healed similarly, but with more rapid healing and more complete remodeling evident by week 24. Although the mean weight of cancellous bone harvested from the proximal portion of the femur (0.82 ± 0.22 g) was significantly (P < 0.05) less than that harvested from the proximal portion of the humerus (1.38 ± 0.29 g), there was no qualitative histologic or radiographic difference in bony healing of grafted defects. We determined that the proximal portion of the femur can be safely used to provide moderate amounts of cancellous bone, and that a second bone graft can be collected from the same subtrochanteric donor site after 12 weeks.
Measurement of total volume and protein concentration of intrauterine secretion after intrauterine inoculation of bacteria in mares that were either resistant or susceptible to chronic uterine infection
Authors: Troedsson Mats H. T. , Liu Irwin K. M.
Published: January 2024

Undiluted uterine secretion was used to determine the concentration of total protein and the accumulated volume of uterine secretion after a bacterial inoculation in mares susceptible and resistant to chronic uterine infection (cui). The uterus of 6 susceptible and 5 resistant mares was inoculated with 5 × 106 Streptococcus zooepidemicus on the third day of estrus. Using a tampon inserted in the uterus, secretions were sampled at 5, 12, 24, and 36 hours after inoculation, followed by intrauterine lavage with phosphate buffered saline solution. The concentration of protein was determined in the undiluted secretion as well as in the uterine washing and the total amount of accumulated uterine secretion was calculated. Protein concentrations in plasma were compared before and after absorption by the tampon.

Protein concentration of plasma before and after absorption by the tampon did not differ. Mares susceptible to cui accumulated significantly (P < 0.001) more fluid in the uterus than mares resistant to cui, and uterine washings from the resistant mares were significantly (P < 0.05) more dilute than those from the susceptible mares. Significant differences in protein concentrations between susceptible and resistant mares were not found. It was concluded from this study that the described method to sample undiluted uterine secretion was practical and reliable for the analysis of protein concentration. Various concentrations of uterine secretions in washings from susceptible and resistant mares emphasizes the importance in using undiluted uterine secretions or dilution markers in washings when intrauterine products are analyzed.
Immunolocalization of epidermal growth factor (egf) and egf receptors in the porcine upper gastrointestinal tract
Authors: Jaeger Laurie A. , Lamar Carlton H.
Published: January 2024

The factors controlling growth and maturation in the porcine gastrointestinal tract are not well understood. Epidermal growth factor (egf) is a polypeptide that has been implicated in the control of gastrointestinal tract growth, maturation, and protection in other species. Immunoreactive egf (ir-egf) and egf receptors (egf-r) were histochemically identified in formalin-fixed tissues of the upper digestive tract of 1-, 3-, 7-, 14-, 21-, and 28-day-old pigs. The ductal epithelium consistently contained ir-egf in the parotid salivary gland of pigs of all ages and in the mandibular salivary gland in pigs ≥ 7 days old. Immunoreactive egf was detected in the mucosal epithelium of the esophagus and nonglandular portion of the stomach, and in the pancreas and liver in all pigs. Gastric gland ir-egf was inconsistently detected in pigs < 14 days old and was consistently observed in all older pigs. Enterocyte egf immunoreactivity was usually weak and was variably detected in the duodenum of pigs ≤ 7 days old and in the jejunum of pigs ≤ 14 days old, but was consistently observed in older pigs. Ileal immunoreactivity was erratic. Immunoreactive egf-r were identified in the esophageal epithelium of all pigs, and in the non-glandular gastric and glandular gastric mucosa of all pigs, except for two 7-day-old pigs and one 7-day-old pig, respectively. Immunoreactive egf-r were detected in the duodenal, jejunal, and ileal enterocytes of pigs of all ages examined.
Ultrasonography of the urinary tract of female sheep
Authors: Braun Ueli , Schefer Ursula , Gerber David
Published: January 2024

We determined the position, dimensions, and structure of the kidneys, ureters, bladder, and urethra of 62 female sheep by use of ultrasonography. A 5.0-MHz convex transducer was placed over the right flank to examine the kidneys, and a 5.0 MHz-linear transducer was used to examine the bladder and urethra transrectally. All examinations were performed on sheep in standing position. The left kidney was 7.1 to 8.9 cm long, 3.4 to 5.5 cm wide, and 3.3 to 4.7 cm deep. Diameter of the parenchyma and renal sinus of the left kidney ranged between 1.1 and 1.9 cm and 1.1 and 2.0 cm, respectively. Circumference of the medullary pyramids varied between 2.1 and 3.3 cm. Similar ultrasonographic measurements were obtained for the right kidney.

The diameter of the bladder varied between 0.3 and 6.9 cm in 96.8% of the sheep. The diameter of the bladder could not be determined in 32% of the sheep because it was > 10 cm, and, therefore, was beyond the penetration depth of the scanner.

The only part of the urethra that could be ultrasonographically visualized was the internal urethral orifice. It had diameter between 0.1 and 0.2 cm. The ureters could not be ultrasonographically visualized in any of the sheep examined.

The urinary tract of 8 sheep was examined 10 times within 2 weeks to examine whether measurements were reproducible. The interassay variation coefficient determined ranged from 3.1 to 31.8%, although for most variables, it ranged between 5 and 11%. Measurements for the length and width of the kidneys had the smallest interassay variation coefficient, whereas values obtained for diameter of the bladder and urethra, as well as thickness of the bladder, had the largest.

It was concluded that the ultrasonographic findings described in this study can be used as references for diagnosis of morphologic changes in the kidneys, bladder, and urethra of sheep.
Radiographically determined growth dynamics of primary lung tumors induced in dogs by inhalation of plutonium
Authors: Perry Ruby E. , Weller Richard E. , Buschbom Ray L. , Dagle Gerald E. , Park James F.
Published: January 2024

Beagles were exposed to aerosols of 239PuO2, 238PuO2, or 239Pu(NO3)4. Exponential growth constants for 50 primary lung tumors (23 bronchioloalveolar carcinomas, 22 papillary adenocarcinomas, 5 adenosquamous carcinomas) were calculated in 37 dogs, using sequential thoracic radiography. A wide range in doubling time (6 to 287 days) was observed. Mean ± sem doubling time was 93 ± 10 days for bronchioloalveolar carcinoma, 107 ± 13 days for papillary adenocarcinoma, and 101 ± 36 days for adenosquamous carcinoma. Lung tumor growth rate in dogs was comparable to that in human patients with similar histologic tumor types. Linear regression analysis revealed significant (P ≤ 0.0001) correlation between doubling time and survival of individual dogs. Doubling time was not significantly dependent on tumor type, sex, age at time of diagnosis, initial lung deposition, or isotope. Extrapolating time to tumor onset from tumor doubling time cannot be used to reliably predict the onset of malignancy.
Variability of serum bile acid concentrations over time in dairy cattle, and effect of feed deprivation on the variability
Authors: Pearson Erwin G. , Craig A. Morrie , Rowe Kenneth
Published: January 2024

Twelve nonlactating dairy cows, free of signs of liver disease and with normal serum activities of liver-derived enzymes and normal liver biopsy tissue, were examined over a 72-hour period for serum total bile acid concentrations. The cattle were fed hay twice daily, and blood samples were obtained every hour for 24 hours, every other hour for 24 hours, then every hour for 24 hours. After 3 weeks, the study was repeated on 6 of the cattle, thus providing data for eighteen 72-hour periods. Serum bile acid concentration varied greatly over the 72 hours, with the range being from one third to 3 times the median. There were variations by as much as 60 μmol/L from 1 hour to the next. After another 3 weeks, 8 of the cattle were deprived of hay for 48 hours and then fed hay morning and afternoon of the third (last) day of the study. There was no significant reduction in bile acid concentration after withholding the hay, but the variability was reduced (P = 0.02) during the last 20 hours of the hay-deprivation period.

In 3 ancillary studies, serum bile acid concentrations were examined over a 48-hour period in 2 cows in early lactation, 3 cows in midlactation, and two 6-month-old heifers. The cows were fed hay and grain twice daily, and the heifers were fed only hay twice daily. In comparison with values for the 12 nonlactating cows fed hay twice daily, mean serum bile acid concentration in the recently freshened cows was significantly (P < 0.002) higher (62.9 vs 22.0 μmol/L). The cows in midlactation had hourly fluctuations as great as 65 μmol/L. Values for the heifers varied less than values in older cattle.
Monophosphoryl lipid A-induced immune enhancement of Brucella abortus salt-extractable protein and lipopolysaccharide vaccines in balb/c mice
Authors: Tabatabai Louisa B. , Pugh George W. , Stevens Mark G. , Phillips Marshall , McDonald Timothy J.
Published: January 2024

A study was conducted to determine the effect of monophosphoryl lipid A (mpl) and trehalose dimycolate (tdm) as adjuvants on the protective responses in balb/c mice vaccinated with Brucella abortus salt-extractable protein (bcsp) or proteinase-K-treated B abortus lipopolysaccharide (pklps). Mice were vaccinated with different doses of bcsp or pklps given alone or in combination with mpl or tdm. Mice were challenge-exposed 4 weeks later with virulent B abortus strain 2308. Two weeks after challenge exposure, the number of B abortus colony-forming units (cfu) per spleen, spleen weights, and spleen cell interleukin 1 production were measured. Serum IgG and IgM concentrations specific for vaccinal immunogens were measured before and after challenge exposure with B abortus.

Spleen weights and mean B abortus cfu per vaccine group were significantly lower in bcsp- and pklps-vaccinated mice, compared with those of nonvaccinated control mice. Monophosphoryl lipid A enhanced the suppression of splenic infection when given with the bcsp vaccine, but not when given with the pklps vaccine. Trehalose dimycolate had no effect on mean cfu when given with bcsp, but incorporation of tdm resulted in a significant increase in mean cfu when given with pklps. Spleen weights in bcsp- or pklps-vaccinated mice were not different when these vaccines were combined with mpl or tdm. Because of the wide variation in the results, we could not conclude that vaccination with bcsp or pklps alone, or in combination with mpl altered spleen cell interleukin-1 production in B abortus-infected mice. Increased host protection as defined by decreased cfu could not be related consistently to increased bcsp- or pklps-specific serum IgG or IgM antibodies introduced by any of the vaccines. These results do not eliminate a role for antibodies in the protection observed.
Bromodeoxyuridine labeling and DNA content of pulmonary arterial medial cells from hypoxia-exposed and nonexposed healthy calves
Authors: Orton E. Christopher , LaRue Susan M. , Ensley Beverly , Stenmark Kurt
Published: January 2024

Vascular medial thickening is a prominent finding in people and animals with refractory neonatal pulmonary hypertension. Smooth muscle cells are capable of 2 distinct growth responses in vivo: hypertrophy or hyperplasia. Hypertrophic smooth muscle cells may undergo dna synthesis without cell division, leading to a polyploid state. To better understand the nature of smooth muscle cell growth in healthy and pulmonary hypertensive neonatal calves, we measured incorporation of the thymidine analog bromodeoxyuridine (BrdUrd) and total dna content in medial cells from control (pulmonary arterial pressure = 32 ± 2 mm of Hg) and hypobaric hypoxia-exposed (pulmonary arterial pressure = 120 ± 7 mm of Hg) calves. Labeling of medial cells with BrdUrd measured by flow cytometry was increased (P < 0.02) in pulmonary arteries of hypoxia-exposed calves (n = 5), compared with control calves (n = 5). Immunohistochemical localization of BrdUrd indicated that BrdUrd labeling of large elastic pulmonary arteries from hypoxia-exposed calves was increased almost exclusively in the outer half of the medial wall. Increased BrdUrd labeling of muscular pulmonary arteries from hypoxia exposed calves was observed in the arterial media and adventitia, and tended to exit in clusters. Analysis of dna content by flow cytometry indicated a decrease (P < 0.05) in percentage of tetraploid medial cells in pulmonary arteries from hypoxia-exposed calves, compared with control calves. Bivariate analysis for BrdUrd labeling and dna content of cells from the pulmonary arteries of hypoxia-exposed calves indicated a subpopulation of diploid cells with positive BrdUrd labeling, suggestive of dna synthesis and subsequent cell division. Results are suggestive of smooth muscle cell hyperplasia in the vascular media of hypoxia-exposed calves.
Malabsorption of vitamin A in preruminating calves infected with Cryptosporidium parvum
Authors: Holland Robert E. , Boyle Stephen M. , Herdt Thomas H. , Grimes Sheila D. , Walker Robert D.
Published: January 2024

Serum retinol, retinyl palmitate, and total vitamin A concentrations, and jejunoileal morphology were examined in neonatal calves infected with Cryptosporidium parvum. Group-1 calves served as noninfected controls and, after an adjustment period, were given 50 ml of saline solution iv every 12 hours for 6 days. Group-2 calves were inoculated with 107 C parvum oocysts and, after the onset of diarrhea, were given 50 ml of saline solution iv every 12 hours for 6 days. Group-3 calves were inoculated with 107 C parvum oocysts and, after the onset of diarrhea, were treated with difluoromethylornithine (dfmo, 200 mg/kg of body weight iv, q 12 h) for 6 days. Group-4 calves were naturally infected with C parvum. Jejunoileal biopsy specimens were excised from calves of groups 1-3 at 3 and again at 15 to 16 days of age. During the course of diarrhea and 3 days after saline or dfmo administration, water-miscible retinyl palmitate was administered orally (2,750 μg/kg) to each calf in each group. Cryptosporidium parvum infection was associated with significant (P ≤ 0.05) reduction in postadministration serum retinol, retinyl palmitate, and total vitamin A concentrations in calves of groups 2, 3, and 4. Cryptosporidium parvum infection caused significant (P ≤ 0.05) reduction in villus height. Decreased villus height, villus blunting and fusion, and attenuation of the intestinal mucosa were associated with reduced absorption of vitamin A, as indicated by lower peak postadministration retinyl palmitate concentration in C parvum-infected calves. Intravenous administration of dfmo to group-3 calves did not improve retinol absorption. Vitamin A should be provided parenterally to young calves with enteric cryptosporidiosis in an attempt to avoid depletion of concurrent low liver vitamin A reserves.