Refine search
Results 41-50 of 439
Safety, efficacy, and effects on copper metabolism of intrareticularly placed selenium boluses in beef heifer calves
1994
Maas, J. | Peauroi, J.R. | Weber, D.W. | Adams, F.W.
Intrareticularly placed sustained-release selenium boluses were administered to 1 group of selenium-deficient heifer calves (n = 16), and a second group (n = 16) was left as nontreated controls. Age range for all calves was 83 to 156 days. These boluses release 3 mg of selenium each day, as sodium selenite. Measurements of blood selenium concentration, plasma copper concentration, hepatic copper concentration, and body weight were made over a 188-day day study. The treated group of calves had significantly higher mean blood selenium concentration at posttreatment days 68 (P < .0001), 112 (P < 0.0001), and 188 (P < 0.005) than did the control group. Mean blood selenium concentration in the treated calves was > 0.10 micrograms/ml for 188 days. These boluses were observed to be clinically safe; signs of selenium toxicosis were not detected and untoward effects were not seen in the selenium-treated calves. There were no differences between control and treatment groups with respect to mean hepatic copper concentration or mean plasma copper concentration. There were no observed differences between the control and treatment groups with respect to weight gain during the study.
Show more [+] Less [-]Enhancement of Pasteurella haemolytica leukotoxic activity by bovine serum albumin
1994
Waurzyniak, B.J. | Clinkenbeard, K.D. | Confer, A.W. | Srikumaran, S.
Growth of Pasteurella haemolytica A1 in RPMI 1640 medium containing 0.5% bovine serum albumin (BSA) for 2.5 hours enhanced culture supernatant leukotoxic activity [30,700 +/- 12,900 toxic units/ml, compared with leukotoxic activity of culture supernatants produced in RPMI 1640 medium alone (120 +/- 40 toxic units/ml)]. Gel filtration chromatography of the leukotoxic activity from RPMI 1640 medium supernatants in buffer containing 50 mM NaCl indicated a single leukotoxic activity peak (peak I) eluting near the gel resin molecular mass exclusion limit (estimated molecular mass of approx 8,000 kd). In contrast, culture supernatants produced in RPMI 1640 plus bovine serum albumin medium (RPMI + BSA) had peak I and 2 additional leukotoxic activity peaks (peaks II and III) with estimated molecular mass of approximately 80 and < 30 kd, respectively. All leukotoxic activity peaks were composed of approximately 100-kd molecular mass leukotoxin protomer, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with a monoclonal antibody against leukotoxin. Subjecting culture supernatant leukotoxic activity produced in RPMI + BSA to gel filtration chromatography in buffer containing 500 mM NaCl or 6M urea resulted in detection of only a single leukotoxic activity peak with estimated approximate molecular mass of 250 and 800 kd, respectively. These findings suggest that P haemolytica exists as a high molecular mass aggregate with low leukotoxic activity which, in the presence of BSA, partially disaggregates to multiple toxin forms with enhanced leukotoxic activity. Some of these leukotoxin forms interact with dextran-based gel resins at low ionic strength.
Show more [+] Less [-]Low blood lead concentration associated with various biomarkers in household pets
1994
Berny, P.J. | Cote, L.M. | Buck, W.B.
A former secondary lead smelter was in operation in Granite City, Ill, until the early 1980s. As a result, the surrounding area is heavily contaminated with lead. Soil concentrations as high as 5,000 ppm have been measured in prior studies. Because of growing concerns about health defects associated with low levels of lead exposure in human beings, a major study has been conducted on people living in the area. The study reported here was a corollary to the human exposure study. Lead concentration was determined in 84 dogs and 26 cats in the town and ranged between < 5 and 28 microgram/dl. None of the dogs had clinical signs of lead poisoning. The CBC and serum biochemical values did not indicate many significant differences between dogs with a high (larger than or equal to 10 microgram/dl) or low blood lead concentration (BLC). Hemoglobin concentrations were lower, and WBC counts were higher in dogs and cats with higher BLC, but they were still within reference ranges. Free erythrocyte protoporphyrin concentration was determined. Normal values appeared to be similar for dogs and cats. Only animals with BLC larger than or equal to 20 microgram/dl were found to have somewhat increased concentration of free erythrocyte protoporphyrin. Delta-aminolevulinic acid dehydratase activity was measured and found to be negatively correlated with BLC. The relation was strong, even at low BLC (5 to 10 microgram/dl) in both species. Age or sex difference was not observed. Therefore, biological changes associated with low BLC were limited to BLC in the 10- to 30-microgram/dl range.
Show more [+] Less [-]Decrease in the alpha 1-proteinase inhibitor Spi3 in equine bronchoalveolar lavage fluid
1994
Milne, E.M. | Pemberton, A.D. | Dixon, P.M. | McGorum, B.C. | Scudamore, C.L. | Miller, H.R.P.
The alpha 1-proteinase inhibitors of trypsin, Spi1, Spi3A, and Spi3B, in bronchoalveolar lavage fluid (BALF) and serum of horses were separated by electrophoresis, and their proportions were quantified in 12 control horses and 12 with chronic obstructive pulmonary disease (COPD). A significantly lower proportion of Spi3B (P < 0.05) and higher proportion of Spi1 (P < 0.02 to P < 0.01) were detected in BALF, compared with serum, in control and COPD-affected horses and appeared to be attributable to reduced Spi3 activity in BALF. There was no significant difference between the control and COPD groups in this respect, indicating that the decrease in Spi3 may be a physiologic phenomenon. The differences observed may be associated with proteolytic damage to or preferential complex formation by Spi3.
Show more [+] Less [-]Effects on lung compliance, lung volume, and single-breath transfer factor for carbon monoxide in sheep with lentivirus-induced lymphoid interstitial pneumonia
1993
Collie, D.D.S. | Watt, N.J. | Warren, P.M. | Begara, I. | Lujan, L.
Static lung compliance, static lung volumes, and transfer factor for carbon monoxide were measured in 12 anesthetized adult Texel ewes seropositive for maedi-visna virus (MVV) and in 11 breed-, sex-, and age-matched seronegative controls. Median static lung compliance in MVV-infected sheep (1.24 L.kPa-1; range, 0.27 to 2,20 L.kPa-1) was not significantly different from that in controls (1.58 L.kPa-1; range, 0.82 to 2.08 L.kPa-1). Median body weight of MVV-infected sheep (56 kg; range, 40 to 75 kg) was significantly (P < 0.05) less than that of controls (65 kg; range, 53 to 87 kg). Median effective alveolar lung volume in MVV-infected sheep (3.36 L; range, 1.44 to 4.52 L) was significantly (P < 0.01) less than that in controls (4.12 L; range, 3.75 to 4.90 L). Median effective end expiratory lung volume in MVV-infected sheep (1.20 L; range, 0.56 to 1.99 L) was significantly (P < 0.001) less than that of controls (1.98 L; range: 1.76 to 2.78 L). Median lung volumes expressed per unit of body weight did not differ significantly between the groups. Median single-breath transfer factor for carbon monoxide in MVV-infected sheep (7.89 mmol-min-1.kPa-1; range, 3.45 to 12.74 mmol.min-1.kPa-1) was significantly (P < 0.001) less than that in controls (14.10 mmol.min-1-kPa-1; range, 10.02 to 18.30 mmol.min-1-kPa-1). Median transfer factor expressed per liter of alveolar volume in MVV-infected sheep (2.44 mmol.min-1-kPa-1.L-1; range, 1.28 to 3.72 mmol.min-1-kPa-1.L-1) gm significantly (P < 0.05) less than that in controls (3.22 mmol.min-1-kPa-1.L-1; range, 2.47 to 3.74 mmol.min-1-kPa-1.L-1). These findings indicate that static lung volumes and transfer factor for carbon monoxide are significantly decreased in adult sheep naturally infected with MVV.
Show more [+] Less [-]Effects of oral administration of anti-inflammatory doses of prednisone on thyroid hormone response to thyrotropin-releasing hormone and thyrotropin in clinically normal dogs
1993
Moore, G.E. | Ferguson, D.C. | Hoenig, M.
Prednisone was given orally to 12 dogs daily for 35 days at an anti-inflammatory dosage (1.1 mg/kg of body weight in divided dose, q 12 h) to study its effect on thyroxine (T4) and triiodothyronine (T3) metabolism. Six of these dogs were surgically thyroidectomized (THX-Pred) and maintained in euthyroid status by daily SC injections of T4 to study peripheral metabolism while receiving prednisone; 6 dogs with intact thyroid gland (Pred) were given prednisone; and 6 additional dogs were given gelatin capsule vehicle as a control group (Ctrl). Baseline T4 concentration after 4 weeks of treatment was not significantly different in dogs of the THX-Pred or Pred group (mean +/- SEM, 2.58 +/- 0.28 or 3.38 +/- 0.58 microgram/dl, respectively) vs dogs of the Ctrl group (2.12 +/- 0.30 microgram/dl). A supranormal response of T4 to thyrotropin was observed in dogs of the Pred group, but the T4 response to thyrotropin-releasing hormone was normal. Baseline T3 concentration in dogs of both steroid-treated groups was significantly (P < 0.05) lower after 2 and 4 weeks of prednisone administration vs pretreatment values, but normalized 2 weeks after prednisone was stopped. Free T3 (FT3) and T4 (FT4) fractions and absolute FT3 and FT, concentrations were not altered by prednisone administration. Reverse T3 (rT3) concentration in vehicle-treated Ctrl dogs (26.6 +/- 3.5 ng/dl) was not different from rT3 concentration in dogs of the THX-Pred (25.7 +/- 4.3 ng/dl) and Pred (28.9 +/- 3.8 ng/dl) groups after 4 weeks of medication. These data indicate that daily oral administration of such anti-inflammatory dose of prednisone for 1 month reduces baseline serum T3 concentration, does not alter serum T4 concentration, and enhances thyroidal sensitivity to thyrotropin.
Show more [+] Less [-]Antigenic and genetic analysis of a recently isolated H1N1 swine influenza virus
1993
Olsen, C.W. | McGregor, M.W. | Cooley, A.J. | Schantz, B. | Hotze, B. | Hinshaw, V.S.
Hemagglutinins HA) of H1N1 swine influenza viruses isolated in the United States have remained antigenically and genetically conserved for many years. In contrast to such conservation, the RA of A/Swine/Nebraska/1/92 (Sw/Neb) could readily be distinguished from those of contemporary porcine viruses. Twenty-eight amino acid mutations differentiated the HA of Sw/Neb and A/Swine/Indiana/1726/88, the most recent H1N1 swine influenza virus for which HA sequence data were available. Among these differences were mutations at potential asparagine-linked glycosylation sites and charge changes at many residues. The Sw/Neb virus also could be differentiated from other swine influenza viruses in hemagglutination-inhibition assays with monoclonal antibodies to recent H1 swine HA. Nonetheless, overall sequence analysis of the HA and the nucleoprotein genes of Sw/Neb indicated that this virus was more closely related genetically to classic H1N1 swine influenza viruses than to H1N1 avian or human viruses. Infection of swine with Sw/Neb under experimental conditions induced clinical signs and lesions typical of swine influenza. However, affected swine in the field had high, persistent fevers, but relatively mild signs of respiratory tract disease. This study indicated that an antigenically and genetically novel variant of swine influenza virus was detected in the United States.
Show more [+] Less [-]Neuropeptidergic innervation of equine synovial joints
1993
Bowker, R.M. | Abhold, R.H. | Caron, J.P. | Sonea, I.M. | Vex, K.B. | Kotyk, R.
Immunocytochemical analysis of equine synovial membranes revealed presence of several neuropeptides, including substance P (SP), neurokinin A, and neuropeptide Y, in nerves of the radiocarpal, middle carpal, and metacarpophalangeal (fetlock) joints. Within the subsynovium, these neuropeptides were located perivascularly, whereas in the fronds, only neuropeptide Y was restricted to the vessels of the synovial membrane. Only SP and neurokinin A were found in the intimal layer. The intimal layer of the metacarpophalangeal joint contained more SP-immunoreactive fibers than were observed in the intimal layer of the radiocarpal joint. Substance P also was detected in the synovial fluid from all 3 joints, but mean +/- SD concentrations were significantly different only between the middle carpal joint (37.56 +/- 5.48 fmol/ml; n = 6) and the metacarpophalangeal joint (55.80 +/- 8.33 fmol/ml; n = 5) and between the middle carpal joint and the radiocarpal joint (52.43 +/- 14.60 fmol/ml; n = 7).
Show more [+] Less [-]Lactulose and mannitol as probe markers for in vivo assessment of passive intestinal permeability in healthy cats
1993
Papasouliotis, K. | Gruffydd-Jones, T.J. | Sparkes, A.H. | Cripps, P.J. | Millard, W.G.
Intestinal permeability was assessed in 12 healthy cats by use of a differential sugar absorption test. A 50-ml isotonic aqueous solution containing a combination of 1.8 g of the disaccharide lactulose and 1.7 g of the monosaccharide mannitol was administered to cats via nasogastric tube. Urine was collected after 6 hours, and all urine samples were analyzed the same day, using a gas-liquid chromatographic technique (GLC) and an enzymatic assay (ENZ). Median urinary recovery of lactulose was 0.27 and 0.54% determined by GLC and ENZ, respectively. Differences between these groups were statistically significant (P = 0.023), and correlation between assays was high (r = 0.94, P < 0.01). Median urinary recovery of mannitol was 1.93 and 2.09% for GLC and ENZ, respectively. There were no statistically significant differences between these groups and the correlation between assays was high (r = 0.85, P < 0.01). The median lactulose-to-mannitol ratio was 0.29, using GLC, and was 0.52, using ENZ. Correlation of these ratios was again high (r = 0.93, P < 0.01).
Show more [+] Less [-]Abomasal interstitial fluid-to-blood concentration gradient of pepsinogen in calves with type-1 and type-2 ostertagiosis
1993
Pepsinogen and protein concentrations were determined in blood samples, collected from the left gastroepiploic artery and vein, and in abomasal lymph from 15 steers naturally infected with Ostertagia ostertagi and 4 uninfected steers. In steers with type-1 ostertagiosis, the concentration gradient between the mucosal interstitium and the blood alone could account for higher than normal serum pepsinogen concentrations. High interstitial pepsinogen concentrations may have resulted from increased epithelial permeability or increased pepsinogen production and secretion. However, in steers with type-2 ostertagiosis, the concentration gradient could not entirely account for the high serum pepsinogen concentrations, suggesting that capillary permeability or surface area may have been altered. Lymphatic uptake contributed pepsinogen to the blood in all infected steers.
Show more [+] Less [-]