Biomedical subjects

G A Anderson

Publications and source records attributed to G A Anderson.

At least 109 records · Page 6Linked to original sources

PubMed1989

Influence of isoprinosine on lymphocyte function in virus-infected feeder pigs.

Pseudorabies is a porcine herpesvirus of major importance in the swine industry. Isoprinosine is an immunomodulating drug that has been shown to be beneficial in treating herpesvirus infections. Twenty-four 7-week-old pigs were allotted within litters to 1 of 4 groups: control, isoprinosine (ISO), pseudorabies virus (PRV), or isoprinosine and pseudorabies virus (ISO-PRV). Isoprinosine was administered daily for 16 days to the ISO and ISO-PRV groups (75 mg/kg of body weight/day, PO). Immunity in pigs in the PRV and ISO-PRV groups was challenged with pseudorabies virus (10(5) TCID50 units) on day 4. Rectal temperatures and viral excretion were monitored daily; total and differential leukocyte counts, lymphocyte response to mitogens, and interleukin-2 production were monitored every 4 days. Pigs challenge-inoculated with pseudorabies virus became ill, with the ISO-PRV group most severely affected. Rectal temperatures were high (P less than 0.05) in virally challenged pigs on days 5 to 12 and 14 to 16; isoprinosine did not alter this effect. Pseudorabies virus-infected pigs had leukocytosis (P less than 0.05) on days 12 and 16, primarily caused by neutrophilia. Concanavalin A-stimulated lymphocyte proliferation was decreased (P less than 0.06) in both PRV and ISO-PRV groups on day 12, compared with control pigs, but only in the PRV group on day 16. Pokeweed mitogen-stimulated lymphocyte proliferation was decreased (P less than 0.02) in ISO-PRV pigs on day 8 of the experiment. Interleukin-2 concentrations, pooled over all sampling days, were decreased (P less than 0.03) in pseudorabies virus-infected pigs. Viral excretion was not altered by isoprinosine treatment. These data suggest that pseudorabies virus infection decreased lymphocyte proliferative responses and interleukin-2 production in pigs, and that isoprinosine did not mitigate these effects.

Animals↗

PubMed1988

Bovine respiratory syncytial virus-specific monoclonal antibodies.

Five hybridomas were produced which secreted monoclonal antibodies to bovine respiratory syncytial virus (BRSV). Two antibodies (8G12, 15C7) neutralized the virus and inhibited syncytia formation in vitro. These monoclonal antibodies also stained, by indirect fluorescent assay, an external envelope protein of living virus-infected cells, and recognized the 48k subunit of the viral fusion protein by Western blot analysis of bovine respiratory syncytial virus-infected cell lysates. Three other monoclonals (6A12, 14D3, 14E3) stained, by indirect fluorescent assay, acetone-fixed virus-infected cells but not living cells. Three hybridomas (6A12, 8G12, 15C7) secreted monoclonal antibody of isotype IgG1, k; two hybridomas secreted monoclonal antibody of isotype IgG2a, k. This apparently is the first report of monoclonal antibodies specific for BRSV glycoproteins.

Animals↗

PubMed1988

Ascaris suum antigens incorporated into liposomes used to stimulate protection to migrating larvae.

Four- to 8-week-old SPF pigs were immunized, using antigens of Ascaris suum incorporated into liposomes, via intestinal cannula or orally. Avridine was also incorporated in the liposomes in one experiment and interleukin-2 (IL-2) injected into pigs in another experiment. A priming dose of embryonate eggs (80-470 eggs/pig) were given in four of six experiments. Compared to control animals, the greatest protection of pigs to migrating ascarid larvae from a challenge dose of 10,000 embryonated eggs occurred where pigs received (1) a priming dose of eggs plus second-stage ascarid larval wall incorporated into liposomes, with or without avridine or IL-2, or (2) a priming dose of eggs plus ascarid intestinal aminopeptidase incorporated into liposomes with IL-2. The degree of protection was not statistically significant due, in part, to the variability in the responses of animals in the same treatment groups and the small number of animals per group. In general, only low titers of specific serum antibodies were detected and specific antibodies were not detected in the intestinal washing.

Animals↗

PubMed1988

The incidence, cost and factors associated with foot lameness in dairy cattle in south-western Victoria.

A survey of 73 dairy farms in south-western Victoria was conducted to assess the cost and mean herd incidence of foot lameness for the period from calving to the end of November, 1985, and to identify the herd, management and environmental factors associated with foot lameness. The mean herd size was 125 cows (range 82 to 220). Lameness occurred in 64 (88%) herds, and the mean herd incidence was 7.0% (range 0.0 to 30.9%). The main clinical signs associated with lameness were the presence of overworn and/or bruised soles, or stones lodged in the interdigital cleft. Factors associated with lameness were: property and herd size, age of cow, bail feeding, voluntary entry into the bails, and features of the farm track including its length, the presence of steep slopes, the type of surface material, presence and treatment of broken sections and maintenance including rolling history. The association of these factors with specific clinical signs was examined. The mean cost was estimated to be $42.90 per lame cow due to loss of production, treatment, the culling or death of lame cows, and extra man hours spent managing lame cows. It was concluded that the site, construction, maintenance and use of the farm track were of major importance to the incidence of lameness in herds in this area and recommendations for reducing lameness are made.

Age Factors↗

PubMed1988

Bacterial tolerance of 100% dimethyl sulfoxide.

Viable bacteria were found in six bottles of dimethyl sulfoxide (DMSO) at a concentration of approximately one bacterium per 4.4 mL. The 18 bacterial isolates appeared to be tolerating the DMSO rather than metabolizing it. No fungi were detected. DMSO must be assumed to be nonsterile unless it has been previously sterilized.

Bacteria↗

PubMed1987

Identification of histamine-receptor leukocytes in the bovine.

Subpopulations of leukocytes have been characterized by using cell surface membrane markers, and attempts have been made to correlate membrane receptors with cellular function. Histamine receptors on cell membranes have been identified in the mouse, man and rhesus monkey by numerous methods. In this study, an immunofluorescent technique was used to identify and enumerate histamine-receptor leukocytes in the peripheral blood of cattle. This report appears to be the first documenting these cells in the bovine.

Animals↗

PubMed1987

Influence of isoprinosine on bovine herpesvirus type-1 infection in cattle.

A study was conducted to determine the in vivo efficacy of isoprinosine (ISO) in calves infected with bovine herpesvirus type-1 (BHV-1). Calves were infected with BHV-1 on day 0 and received ISO daily for 14 days. Clinical signs of disease, shedding of BHV-1, lymphocyte proliferative responses to mitogens, interleukin-2 production, and alveolar macrophage bactericidal activity were monitored during the study. Rectal temperatures were increased (P less than 0.05) in BHV-1 and ISO-BHV-1 calves at days 3 to 7 postinfection (PI). Isoprinosine did not influence BHV-1 shedding in calves. Lymphocyte proliferative responses to phytohemagglutinin (PHA) were lower (P less than 0.01) in BHV-1 calves when compared to control or ISO calves at day 4 PI, but ISO did not ameliorate this effect. Interleukin-2 activity was greater (P less than 0.05) in ISO-BHV-1 calves on days 4 and 8 PI in PHA-stimulated lymphocytes and on day 8 PI in concanavalin A-stimulated lymphocytes when compared to control, ISO or BHV-1 calves. Isoprinosine treatment of BHV-1-infected calves tended to decrease alveolar macrophage bactericidal activity. These data suggest that ISO does not reverse BHV-1 suppression of lymphocyte proliferation, but may enhance IL-2 production in BHV-1 infected calves.

Animals↗

PubMed1987

Identification of bluetongue virus-specific immunoglobulin E in cattle.

A modified passive cutaneous anaphylaxis test and an ELISA were used to identify IgE in calves vaccinated (sensitized) with chlorine dioxide-inactivated bluetongue virus (BTV) and in calves inoculated with infectious BTV. The levels of IgE were greatest in the vaccinated calves after challenge with infectious virus, which correlated with development of clinically apparent dermatitis and stomatitis. These findings suggest that some aspects of clinical bluetongue disease in cattle may have an immunopathological mechanism mediated by IgE (type I hypersensitivity).

Animals↗

PubMed1987

A clinical trial using a regimen which includes a norgestomet implant and norgestomet plus oestradiol valerate injection as a treatment for anoestrus in dairy cows.

In seasonally calving dairy herds in the Macalister Irrigation Area of Gippsland, Victoria, cows that had not been observed in oestrus by the start of the mating season and which had inactive ovaries based on rectal palpation and progesterone assay were treated with a hormonal treatment (n = 49). Mature cows had calved at least 40 days previously and 2-year-olds had been calved at least 60 days. The treatment consisted of a norgestomet implant and a norgestomet and oestradiol injection on day 1; prostaglandin analogue Prosolvin) on day 8; withdrawal of implant on day 10 and an injection of PMSG; and fixed time artificial insemination 54 to 56 h after implant withdrawal. This treatment was called the Syncro-mate regimen. Control cows (n = 46) were injected with water on days 1, 8 and 10 and artificially inseminated or served by a bull when seen on heat. Forty seven percent of the treated cows became pregnant within 14 days from the start of treatment compared with 20% of control cows (P less than 0.01). There was an effect of age group on the response to treatment. A greater proportion of 2-year-old cows than mature cows became pregnant within 14 days of treatment (79% of 19 v. 27% of 20; Chi square interaction, treatment by age, 6.4, P less than 0.05). In the younger cows there was also a gain of 22 days in the treatment to conception interval over the control cows (P less than 0.001). It was concluded that the Syncro-mate regimen can be an effective treatment for post partum anoestrus in dairy cows under certain conditions.

Anestrus↗

PubMed1987

Helminth remains from prehistoric Indian coprolites on the Colorado Plateau.

Examination of coprolites excavated from archaeological sites in the Americas demonstrates excellent preservation of helminth eggs and, in some cases, larvae. To gain an understanding of helminth parasitism in prehistory on the Colorado Plateau of Arizona, New Mexico, and Utah, 319 coprolites from 5 archaeological sites were analyzed. Helminth eggs and larvae were recovered after the coprolites were rehydrated, screened, and sedimented. At a sixth site, soils excavated from 5 rooms used as latrine areas were processed with palynological techniques. The results indicate that all but 1 of the prehistoric populations examined were infected with intestinal worms. The helminths implicated are Enterobius vermicularis, Trichuris trichiura, cf. Ascaris lumbricoides, cf. Trichostrongylus sp., cf. Strongyloides sp., taeniid cestodes, and hymenolepidid cestodes. The study suggests that prehistoric hunter-gatherer peoples carried fewer helminth parasites than agriculturalists. At 1 site, it appears that increased helminth parasitism preceded abandonment of the village.

Animals↗

PubMed1986

Assessment of prognosis for racing after carpal surgery in 210 Thoroughbreds.

The efficacy of treating carpal lesions by arthrotomy was evaluated in 210 Thoroughbred racehorses, using survival analysis to compare their racing performances and earnings with those of 840 control horses. The treated horses were significantly inferior with respect to races contested, and wins plus places (P less than 0.001) and races won (P less than 0.01). There was no difference with respect to earnings (P less than 0.1); after adjusting for other factors, arthritis, site of fracture and presence of a displaced chip had no effect on racing performance in horses with a single-site lesion involving a chip.

Animals↗

PubMed1985

Pregnancy rate of cows given synthetic gonadotrophin-releasing hormone at the time of service.

A trial involving 25 herds was conducted in the Maffra area of Victoria to study pregnancy rates after injection of synthetic Gn-RH at service. Of 3502 cows having a first service, 674 cows were injected by the farmer at first service with a single intramuscular injection of 250 micrograms of synthetic Gn-RH, while the remaining 2828 cows acted as untreated controls. First service pregnancy rates were 58.8% in the group treated with Gn-RH and 54.1% in the untreated group, a 4.7% increase or an odds ratio of 1.21 (P less than 0.05). However, adjustment for the potentially confounding variables calving to first service interval and herd reduced the odds ratio to 1.07 (P less than 0.4). Treatment with Gn-RH at second or third service did not alter pregnancy rate to that service compared to untreated services. There was no interaction of treatment with Gn-RH at first service with calving to service interval. It is concluded that injection of 250 micrograms of synthetic Gn-RH at the time of service does not increase pregnancy rate to that service.

Animal Husbandry↗

PubMed1985

Subclinical and clinical bluetongue disease in cattle: clinical, pathological and pathogenic considerations.

Calves immunized (sensitized) with alcide-inactivated bluetongue virus (BTV) developed immunoglobulin (Ig) E-specific antibody to BTV. Development of clinically apparent disease occurred after challenge with virulent BTV, and lesions correlated with peak levels of virus-specific IgE, an eosinophilic dermatitis, and high concentrations of histamine in the skin. IgE may be important in the pathogenesis of clinical bluetongue (BT) disease in cattle.

Animals↗

PubMed1984

A comparison of six methods used for detecting pregnancy in sheep.

The speed and accuracy of 4 ultrasonic devices (Scanopreg, Pregmatic 3, Medata external probe and Medata rectal probe) were compared with udder scoring and harnessed vasectomised rams as methods of pregnancy diagnosis in 177 ewes, 59 of which were non-pregnant. When using the Scanopreg in ewes of greater than 50 days gestation, accuracy in pregnant ewes averaged 98% and in non-pregnant ewes 87%. The Pregmatic 3 was 97% accurate in pregnant ewes after 50 days gestation and was 96% accurate in non-pregnant ewes. Ewes were examined at between 85 and 185 per hour using these devices. The Medata external probe was 99% accurate in pregnant ewes of greater than 110 days gestation but less accurate in early gestation. This instrument averaged 89% accuracy in non-pregnant ewes and an examination rate of 29 to 35 ewes per hour was achieved. The Medata rectal probe averaged 85% accuracy in pregnant ewes after 70 days gestation. Accuracy averaged 94% in non-pregnant ewes. Ewes were examined at between 35 and 59 per hour using this device. After 130 days gestation 84% of ewes had firm, obviously enlarge udders and another 14% had slight to moderate udder development. After 130 days gestation thick, clear udder secretions were expressed from 18% of ewes and thick, milky udder secretions were expressed from 8%. Harnessed vasectomised rams raddled one of 118 pregnant ewes (an accuracy in pregnant sheep of 99%) and raddled 53% of non pregnant ewes. It was concluded that the ultrasonic pregnancy testing devices have a commercial role, especially as aids to decision making.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1984

Survey of resting blood pressure values in clinically normal horses.

Resting coccygeal blood pressure values were measured, indirectly, on 296 horses (97 Thoroughbreds, 97 Standardbreds and 102 hacks). Blood pressure was found to vary with the class of horse examined; on average Thoroughbreds had significantly higher values than Standardbreds and hacks, whereas blood pressures of the last two groups were not significantly different. There was no demonstrable effect of sex, height or heart rate on blood pressure, but temperature and age did influence the value recorded. Mean (+/- sd) (n = 296) coccygeal uncorrected values (systolic pressure/diastolic pressure) were 112.1 +/- 16.5/77.3 +/- 14.3 mmHg. Allowing for bladder width to tail girth ratios used in each measurement, actual coccygeal pressures of 122.8 +/- 18.6/71.0 +/- 13.4 mmHg were determined. The latter corresponded to values of 149.4 +/- 19.0/97.6 +/- 14.0 mmHg, when corrected to heart (shoulder) level. Normal limits (defined as within 2.5th and 97.5th percentiles) for all horses, regardless of class, were 80 to 144 mmHg/49 to 105 mmHg for coccygeal uncorrected values and 86 to 159 mmHg/45 to 97 mmHg adjusted for bladder width to tail girth ratio.

Age Factors↗

PubMed1984

Importance of uniform cuff application for equine blood pressure measurement.

Seventeen horses were used to determine the variances associated with blood pressure cuff application (Sp2) and with other inherent errors (So2). Systolic pressure values had Sp2 = 3.9 mmHg and So2 = 5.6 mmHg, while diastolic pressure values had Sp2 = 1.1 mmHg and So2 = 4.4 mmHg. Thus, to be considered different, two blood pressure means (in mmHg), each derived from three readings, had to differ by at least 3.9 for systolic pressure and 3.4 for diastolic pressure when all readings were made without cuff displacement; 6.8 for systolic pressure and 4.6 for diastolic pressure when the cuff was reapplied between, but not during, measurement of each mean; and 5.0 for systolic pressure and 3.8 for diastolic pressure when the cuff was reapplied between all readings. It was concluded that uniform cuff application is readily achieved.

Analysis of Variance↗

PubMed1984

Function of prostaglandins, thromboxane A2, and histamine in hypersensitivity reaction to experimental bluetongue disease in calves.

Calves given 2 subcutaneous inoculations (4 ml, 4.5 weeks apart) of an inactivated bluetongue virus serotype 17 (BTV-17), aluminum hydroxide adjuvant, and cimetidine (600 mg) or levamisole (819 mg, 6 ml) combination were challenge exposed with virulent BTV-17 (2.5 x 10(5) embryo lethal dose) 9 weeks after the 1st inoculation and were monitored for 35 days. Plasma prostaglandins (PG) and thromboxane (Tx) B2 were measured by radioimmunoassay. Histamine was assayed spectrofluorometrically. During the inoculation period (9 weeks from the 1st inoculation to challenge exposure) PGE and histamine increased from base-line concentrations of 34 +/- 3 pg/ml and 1.2 +/- 0.1 ng/ml to 83 +/- 8 pg/ml and 2.0 +/- 0.1 ng/ml, respectively, whereas PGF2 alpha decreased from base-line values of 356 +/- 41 pg/ml to 226 +/- 16 pg/ml. Significant (P less than or equal to 0.05) changes from base-line TxB2 values (110 +/- 7 pg/ml) were not observed during the inoculation period. After challenge exposure, maximum increases were observed in TxB2 (157 +/- 10 pg/ml), PGF2 alpha (713 +/- 93 pg/ml), PGE (140 +/- 30 pg/ml), and histamine (3.6 +/- 0.2 ng/ml) concentrations at 4, 7, 7, and 14 days after challenge exposure, respectively. Concentrations of PGF2 alpha and TxB2 decreased from base-line values to 211 +/- 42 pg/ml and 75 +/- 11 pg/ml, respectively, 21 days after challenge exposure and then returned to base-line values. Significant changes were not observed in plasma concentrations of 6-keto-PGF1 alpha. Results indicate that PG, TxA2, and histamine may be involved in the hypersensitivity reaction to BTV in cattle.

Animals↗

PubMed1983

Fatal acorn poisoning in a horse: pathologic findings and diagnostic considerations.

Acorn poisoning was diagnosed in an 11-year-old Quarter Horse with signs of severe colic, tachycardia, hyperpnea, abdominal borborygmus, rectal tenesmus, and hemorrhagic diarrhea. The diagnosis was based on history and predisposing factors, clinical signs, laboratory data, acorn husks in the feces, the urinary gallic acid equivalent concentration, and necropsy findings. The most striking pathologic changes were gastrointestinal and mesenteric edema, ulcerative enterocolitis, and nephrosis.

Animals↗