Biomedical subjects
M T Kearney
Publications and source records attributed to M T Kearney.
Comparison of oxidant production by bovine neutrophils and monocyte-derived macrophages stimulated with Brucella abortus strain 2308.
Oxidant production by bovine monocyte-derived macrophages and neutrophils was compared after stimulation with phorbol myristate acetate (PMA), opsonized zymosan (OZ), and B. abortus opsonized with naive-autologous, reactor, or fetal bovine sera. Neutrophils responded more rapidly to all stimuli and produced up to 100-fold greater oxidant than did equal numbers of bovine monocyte-derived macrophages. Macrophages and neutrophils stimulated with PMA, OZ, and reactor-opsonized B. abortus had higher mean oxidant production than phagocytes exposed to B. abortus opsonized with autologous sera, fetal bovine serum, or nonopsonized bacteria. Stimulation of macrophages by opsonized zymosan, buffer, and B. abortus opsonized with autologous sera, reactor serum, or fetal bovine serum resulted in low levels of oxidant production that were not significantly different. Only PMA caused a significantly higher level of oxidant production by macrophages.
Evaluation of ivermectin against experimental infections of Haemonchus contortus and Trichostrongylus colubriformis in goats.
Fourteen nematode parasite-naïve kids were given a mixed larval inoculum (approximately 17,250 infective larvae) via stomach tube. Twenty-two days after infection, the kids were randomly assigned to control and treatment groups of seven animals each. Mean eggs per gram for control and treatment groups were 4304 and 5315, respectively. Kids in the treatment group were given ivermectin (0.2 mg kg-1) administered by subcutaneous injection. At necropsy, the mean numbers of Haemonchus contortus and Trichostrongylus colubriformis for control and treatment groups were 2259 and 0, and 3033 and 773, respectively. This reduction was significant (P less than 0.05) for both species, resulting in an efficacy of 100.0% and 74.5%, respectively. The lower efficacy against T. colubriformis may be a sign of resistance, a reduced effectiveness due to route of administration, or a higher dose may be required with subcutaneous administration, as has been observed previously.
Effect of fenbendazole molasses supplement block treatment on nematode infection and subsequent weight gain of weanling beef calves.
Two trials were conducted to evaluate the effect of fenbendazole molasses supplement block treatment on weight gain of weanling beef calves. An initial (November) oral fenbendazole (5 mg kg-1) treatment was administered to all animals in both trials. In Trials 1 and 2, respectively, two fenbendazole molasses supplement block treatments were administered 6 (6.4 mg kg-1) and 16 (7.0 mg kg-1) weeks later and 7 (3.4 mg kg-1) and 14 (3.8 mg kg-1) weeks later. During the treatment periods, calves were maintained on dormant bermuda grass pasture, supplemented with hay and protein/mineral blocks. The first block treatment was administered approximately midway through the supplement period to suppress the infection level when nutrition was marginal. The second treatment was administered just prior to ryegrass grazing. Trial 1 and 2 treatments resulted in reducing the infection level, as indicated by reduced mean fecal egg counts. Treatment group mean fecal egg counts remained lower than control group mean counts throughout each trial. In Trial 1, the treatment group gained 29.5 kg more than the control group. In Trial 2, the control group gained 15.5 kg more than the treatment group. Fecal egg count data indicated that the infection level during Trial 1 was higher than during Trial 2. This difference could influence weight gain.
Effects of intra-articular administration of methylprednisolone acetate on normal articular cartilage and on healing of experimentally induced osteochondral defects in horses.
The effects of intra-articular administration of methylprednisolone acetate (MPA) on the healing of full-thickness osteochondral defects and on normal cartilage were evaluated in 8 horses. In group-1 horses (n = 4), a 1-cm-diameter, full-thickness defect was created bilaterally in the articular cartilage on the dorsal distal surface of the radial carpal bone. Cartilage defects were not created in group-2 horses (n = 4). One middle carpal joint was randomly selected in each horse (groups 1 and 2), and treated with an intra-articular injection of 100 mg of MPA, once a week for 4 treatments. Injections began 1 week after surgery in group-1 horses. The contralateral middle carpal joint received intra-articular injections of an equivalent volume of 0.9% sodium chloride solution (SCS), and served as a control. Horses were evaluated for 16 weeks, then were euthanatized, and the middle carpal joints were examined and photographed. Synovial and articular cartilage specimens were obtained for histologic and histochemical evaluation. Gross morphometric evaluation of the healing defects in group-1 horses revealed that 48.6% of the defect in control joints and 0% of the defect in MPA-treated joints was resurfaced with a smooth, white tissue, histologically confirmed as fibrocartilage. This replacement tissue was a firmly attached fibrocartilage in control joints and a thin fibrous tissue in MPA-treated joints. The articular cartilage in joints treated with MPA had morphologic changes, including chondrocyte cluster formation, loss of palisading architecture, and cellular necrosis in both groups of horses.(ABSTRACT TRUNCATED AT 250 WORDS)
Avian paramyxoviruses from migrating and resident ducks in coastal Louisiana.
Cloacal and tracheal swabs were collected from 1,409 hunter-killed ducks in Cameron Parish, Louisiana, during the 1986 and 1987 waterfowl seasons. Thirty avian paramyxoviruses (PMV's) were isolated from 605 blue-winged teal (Anas discors), 75 mottled ducks (A. fulvigula), 375 gadwalls (A. strepera), 334 green-winged teal (A. crecca), and 20 mallards (A. platyrhynchos). Prevalence of PMV decreased (P = 0.042) from September (4%) through November (2%) to December and January (1%). Juveniles had a higher prevalence of PMV (P less than 0.0001) than adults. An isolate from resident mottled ducks documents transmission of PMV's on the coastal wintering areas of Louisiana. The four serotypes isolated, PMV-1, PMV-4, PMV-6, and PMV-8, were typical of PMV's commonly associated with free-living waterfowl.
Antibodies to vesicular stomatitis New Jersey type virus in white-tailed deer on Ossabaw Island, Georgia, 1985 to 1989.
From 1985 to 1989, 491 serum samples were collected from white-tailed deer (Odocoileus virginianus) on Ossabaw Island, Georgia (USA) and were tested for neutralizing antibodies to New Jersey and Indiana type vesicular stomatitis viruses. Prevalence of antibodies to vesicular stomatitis New Jersey (VSNJ) virus in deer for the 5-yr period was 43%. Prevalence of antibodies differed by year (P less than 0.0001), and was dependent on age class (P less than 0.0001) and location on the island (P less than 0.0001). Of 173 deer sampled from other locations in the southeastern United States, only two had VSNJ antibody titers normally considered positive (greater than or equal to 1: 32). The positive deer were from Union County, Arkansas (USA) and Wakulla County, Florida (USA). No evidence of exposure to vesicular stomatitis Indiana Virus was observed.
Quantitative urinalysis in kittens from four to thirty weeks after birth.
To evaluate renal function and obtain reference values for measurements of urinary excretion of various substances, quantitative urinalysis was performed in healthy, growing kittens from 4 to 30 weeks after birth. Endogenous creatinine clearance, 24-hour urine protein excretion, and urine protein-to-creatinine ratio were determined. Additionally, fractional excretion to creatinine clearance was calculated for calcium, inorganic phosphorus, sodium, potassium, and chloride. Mean +/- SD endogenous creatinine clearance values (range, 3.80 +/- 0.48 to 4.74 +/- 0.61 ml/min/kg) were significantly (P less than 0.0001) higher in kittens 9 to 19 weeks old, compared with younger (range, 1.39 +/- 0.85 to 3.59 +/- 0.86 ml/min/kg) and older kittens (range, 2.69 +/- 0.40 to 3.46 +/- 0.37 ml/min/kg). Mean values for all kittens for 24-hour urine protein excretion (range, 2.54 +/- 1.81 mg/kg at 4 weeks to 11.39 +/- 7.61 mg/kg at 14 weeks) and for urine protein-to-creatinine ratio (range, 0.14 +/- 0.03 to 0.34 +/- 0.18) varied from week to week of age. The urine protein-to-creatinine ratio in kittens greater than or equal to 9 weeks old correlated well (R2 = 0.861) with 24-hour urine protein excretion. Urinary fractional excretion of calcium, inorganic phosphorus, sodium, potassium, and chloride in kittens varied among age groups, being significantly (P less than 0.01) different for potassium and calcium in young kittens (4 to 6 weeks) and older kittens (greater than or equal to 7 weeks).
Ophthalmic corticosteroid therapy: systemic effects in the dog.
Degenerative myopathy suggestive of glucocorticoid-induced myopathy was diagnosed in a 10-year-old female Poodle X Pekingese dog with a history of progressive lameness. Electromyography revealed bizarre high-frequency discharges. Evidence of adrenal suppression was obtained in response to exogenous ACTH. The predominant source of corticosteroid was an ophthalmic preparation used in the management of keratoconjunctivitis sicca. Considering the apparent adverse effects of the corticosteroid in this case, a study was undertaken to determine the systemic effects, if any, induced by long-term ophthalmic administration of 0.1% dexamethasone suspension in healthy adult dogs. Dogs in one group (n = 5) were treated 4 times daily for 8 weeks, and dogs in another group (n = 5) were treated 4 times daily for 16 weeks. All dogs remained healthy throughout the study, but dexamethasone-treated dogs developed marked adrenal suppression, beginning the second week of treatment and intensifying throughout the treatment period. Histopathologic changes in the liver of dexamethasone-treated dogs included scattered foci of vacuolated hepatocytes, increased hepatocytic glycogen content, and ballooning degeneration of hepatocytes. Muscle specimens were histologically, histochemically, and electromyographically normal.
Hypovolemia, hyperosmolality, and acidosis associated with intraperitoneal infusion of nitrofurazone solution in healthy horses.
Nitrofurazone solution containing 0.2% nitrofurazone and 99.8% polyethylene glycol was given to 4 healthy horses (2 L in 2 L of lactated Ringer solution, intraperitoneally). Horses developed hypovolemia, hyperosmolality, and mixed respiratory and metabolic acidosis. These changes were largely attributable to polyethylene glycol, but a contribution of nitrofurazone cannot be excluded. Intraperitoneal infusion of nitrofurazone solution in horses is contraindicated.
Efficacy of oxfendazole against inhibited larvae of Ostertagia ostertagi acquired by calves in the spring.
During the spring of 1985, 40 calves grazed pastures known to have high numbers of spring inhibition-prone, infective Ostertagia ostertagi larvae. Calves were removed from pasture and placed in outdoor pens with concrete floors from 10 days prior to treatment until necropsy 14 days after treatment. Ten calves were allocated to each of 4 treatment groups, and oxfendazole was administered to each group by intraruminal injection at dosages of 0, 2.25, 4.5, and 6.75 mg/kg of body weight. Efficacies greater than or equal to 94.6% were achieved at dosages of 4.5 and 6.75 mg/kg against adult Ostertagia spp, Trichostrongylus spp, Haemonchus placei, Cooperia punctata, Bunostomum phlebotomum, Oesophagostomum radiatum, and Dictyocaulus viviparus. Efficacy against inhibited larvae of O ostertagi was variable, with the highest efficacy (90.2%) attained at a dosage of 6.75 mg/kg.
Evaluation of gamma-glutamyl transpeptidase-to-creatinine ratio from spot samples of urine supernatant, as an indicator of urinary enzyme excretion in dogs.
gamma-Glutamyl transpeptidase activity was measured accurately in canine urine supernatant without gel filtration and was relatively stable at 4 C for at least 4 days after collection. The urinary gamma-glutamyl transpeptidase-to-creatinine ratio in spot samples was simple and quick to measure and was correlated with the 24-hour enzyme excretion. However, the usefulness of this ratio may be limited by within-day variation, and a questionable theoretical basis for its validity.
Efficacy of levamisole and netobimin against Haemonchus contortus in lambs in Louisiana.
Efficacy of levamisole was evaluated in a suspected levamisole-resistant population of Haemonchus contortus in the Louisiana State University sheep flock. The efficacy of netobimin also was evaluated against this population of Haemonchus. In trial 1, 5 lambs naturally infected with H contortus were given 8 mg of levamisole/kg of body weight as a drench, and 5 lambs were not treated (controls). Nematode recovery after slaughter indicated 0% efficacy against H contortus. In trial 2, 30 nematode-free lambs were each given 8,300 F1 generation infective larvae of H contortus, which were derived from parent H contortus that survived 2 levamisole treatments in lambs being maintained in a nematode-free environment. Ten lambs were treated with 8 mg of levamisole/kg as a drench, 10 were treated with 20 mg of netobimin/kg as a drench, and 10 were not treated (control). Nematode recovery after slaughter revealed 62.3% and 99.8% efficacy for levamisole and netobimin, respectively, against H contortus.
Diskospondylitis in a kennel of dogs: clinicopathologic findings.
Selected aspects pertaining to the cause and pathogenesis of diskospondylitis were investigated in a kennel of 45 Airedale Terriers. Diskospondylitis was detected via spinal radiography in 17 male and 14 female dogs. Bacteria isolated from the coat, vagina, and urine of affected Airedales were not statistically different from those isolated from clinically normal Airedales. Serologic evidence of Brucella canis infection was not detected. There was no difference in response to thyrotropin stimulation tests between affected and clinically normal dogs. Necropsy findings in affected dogs included hypercellular renal glomeruli and pulmonary arterial thrombi.
Immunosuppression of lymphocyte blastogenesis in cattle infected with Ostertagia ostertagi and/or Trichostrongylus axei.
Twenty 4-month-old calves were infected with O ostertagi and/or T axei and the responses to phytolectins were evaluated. Whole blood cultures were incubated with phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). The blastogenic response was determined by tritiated thymidine uptake with results presented as counts per minute (cpm), stimulation indices (SI) and a mononuclear cell responsive index determined by dividing the phytomitogen induced cpm by the absolute mononuclear cell number per ul. The control group results were adjusted to 100 percent and changes in the percentage difference by the parasitized calves was determined. There was a decline in lymphocyte responsiveness to PHA beginning at the time of infection. Significant depression of responses to PHA was observed in all parasitized calves 8 weeks after infection although clinical signs of parasitism did not occur. Lymphocyte responses to PW, were not different in infected calves from the control, although the O ostertagi group had significantly higher PWM mean upon than the calves infected with T. axei. A slight depression in response to Con A was also observed at 8 weeks after infection followed by a significant increase after 10 weeks. The immunosuppression appeared to be a feature of gastrointestinal parasitism and related to infections with O. ostertagi and/or T. axei.
Comparison of single-dose and conventional trimethoprim-sulfadiazine therapy in experimental Staphylococcus intermedius cystitis in the female dog.
Cystitis was produced in 4 groups of 6 female dogs each, using salicylic acid, ethanol, and Staphylococcus intermedius. Group-I dogs served as nontreated controls. Starting 2 days after infection was induced, group-II dogs were treated with trimethoprim-sulfadiazine at a dosage of 15 mg/kg given orally 2 times a day for 21 days; groups-III and -IV dogs were treated with single oral dosages of the antibiotic at 60 mg/kg and 90 mg/kg, respectively. Group-I dogs (controls) remained infected for the 26-day duration of the study. The response to therapy seen in group-II dogs was better than the therapeutic responses in groups-III and -IV dogs (P less than 0.05). Results of the present study do not support the efficacy of single-dose therapy for this model of cystitis.
Carpal hyperextension in two-month-old pups.
Abnormal carpal configuration was observed in a litter of ten 2-month-old pups raised in a research colony. Five of the pups were exercised daily, and carpal configuration returned to normal within 7 to 10 days. The other 5 pups remained confined, and their carpal configuration returned to normal after 6 weeks. It was concluded that poor muscle tone was responsible for the carpal hyperextension.
Comparative evaluation of a commercial microdilution method and a conventional disk diffusion method for determination of antibiograms of gram-positive cocci.
A commercial broth microdilution system for testing the antimicrobial susceptibility of gram-positive cocci was compared with the standardized disk agar-diffusion method by testing 254 clinical strains of staphylococci and streptococci using both methods. A total of 2,794 parallel determinations were made with 92.3% complete agreement between the 2 methods; of the discrepancies encountered, 3.0% were minor, 2.5% were major, and 2.1% were very major. The results indicate that the commercial microdilution system may provide a reliable quantitative method for antimicrobial susceptibility testing of clinical isolates from animals.