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Biomedical subjects

N V Anderson

Publications and source records attributed to N V Anderson.

At least 19 recordsLinked to original sources
PubMed2000

Prevalence of Salmonella in beef feeder steers as determined by bacterial culture and ELISA serology.

Results are presented for monitoring Salmonella infection by bacteriological culture and immune response (enzyme linked immunosorbent assay (ELISA) and haptoglobin) testing of samples collected from beef cattle at a single feedyard sampled over time. A total of 120 beef steers were examined on entry to the feedyard and at days 30, 60, and at time of slaughter (120-150 days). Isolations of Salmonella decreased over time from 40% of the steers sampled at day 0 to 0% at slaughter, whereas serological results varied by serogroup. Seropositivity increased for Salmonella group B up to day 60, and subsequently decreased to about half of the 60-day positivity rate at the time of slaughter. No significant changes in seropositivity were detected during the course of the study for the four other Salmonella serogroups (C1, C3, D1, and E1). Haptoglobin measurements were not a good indicator of Salmonella infection status. Sequential Salmonella testing either by culture, ELISA, or both could be used to monitor pathogen control practices.

Animal Husbandry↗
PubMed2000

Interalveolar septal changes with Pasteurella haemolytica-induced pneumonia in exertion-stressed calves.

This study compared the effects of exertion stress and exertion stress combined with P. haemolytica infection on cells in the pulmonary capillaries and interalveolar septa adjacent to pneumonic lung. Two calves stood on an Anamill treadmill to serve as nonexercised controls and four calves were run to exhaustion (exertion-stressed) on the treadmill. Two of these four calves were inoculated endobronchially with 5 x 10(9) CFU of virulent Pasteurella haemolytica immediately following treadmill exercise. All calves were euthanized 24 h later and lung tissue was collected from the right mid-caudal lung lobe, next to the area of the gross lesion in inoculated calves. Ultrastructural evidence of increased metabolic activity of pulmonary intravascular macrophages (PIMs) and slight alveolar edema were present after exertion stress, but no changes in numbers of PIMs and platelets were observed between exertion-stressed and control calves. Lungs of calves that were subjected to stress and experimental infection had increases in size, number, and metabolic activity of PIMs, and numerous platelets that were interspersed among the PIMs. These findings suggest that exercise has minimal effect on the cellular changes in interalveolar septa after 24 h. However, exercise with P. haemolytica infection can stimulate PIM activity at short distances (<2.5 mm) from the gross pneumonic lesion. It is possible that the alterations in PIMs are stimulated by cytotoxic products arising from a nearby lesion in which bacteria and infiltrated cells are present.

Animals↗
PubMed1999

Purification of two equine pepsinogens by use of high-performance liquid chromatography.

OBJECTIVES: To purify and characterize pepsinogens in equine gastric mucosa. SAMPLE POPULATION: Stomachs collected from 2 healthy horses at necropsy. PROCEDURE: After collection, stomachs were placed immediately in ice before storage at -48 C. After slow thawing, the mucosa was scraped off while the tissue was immersed in 0.1M potassium phosphate (pH 7.4) at 4 C, then was homogenized. The filtered extract was subjected to anion-exchange chromatography. Fractions that were found to contain pepsin or pepsinogen were further chromatographed. Individual fractions were tested for pepsinogen or pepsin content by monitoring proteolytic activity at pH 2 and 3, respectively. Fractions from all columns were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to confirm molecular weight of pepsinogens and pepsin. RESULTS: Two pepsinogens and at least 1 pepsin were purified from equine gastric mucosa. CONCLUSIONS: On the basis of molecular mass, equine gastric mucosa contains 2 pepsinogens. CLINICAL RELEVANCE: Results of this study will enable future development of an ELISA or radioimmunoassay for use in the diagnosis of equine gastric ulceration.

Animals↗
PubMed1998

Overview of diseases and drug needs for sheep and goats. Veterinarians' and producers' perspectives.

A survey among small ruminant veterinary practitioners and producers of the United States was conducted to determine the most important health problems of sheep and goats and the need for drugs to treat these diseases. Gastrointestinal nematodes and pneumonia were the most important health concerns. Ceftiofur, long acting tetracyclines, penicillins, tilmicosin and enrofloxacin were the antibiotics most needed. The approval of ivermectin and albendazole for goats, and fenbendazole for sheep were among the most common requests for anthelmintics. Veterinarians also stressed the need for drugs to manipulate the estrous cycle, anti-inflammatory drugs, analgesics and anesthetics. Among the viral diseases, lentivirus infections (ovine progressive pneumonia and caprine arthritis encephalitis) and soremouth were the greatest concerns among veterinarians and producers. Both groups indicated that the availability of a generic antiviral drug would be important. The lack of a rabies vaccine was of great concern particularly among goat producers. Extra-label use of drugs in food animals may result in drug residues in tissues that may be hazardous for consumers. Therefore; in order for producers to provide high quality, safe products while remaining competitive in a global market economy, research to determine safety levels and tissue depletion times of new drugs is an urgent need for the sheep and goat industry.

Animal Husbandry↗
PubMed1995

Septicemic salmonellosis in two llamas.

At necropsy, Salmonella choleraesuis var kunzendorf was recovered from the lungs of a 6-year-old female llama that died within a few days of onset of illness. The llama had had fence-line contact with 40 sows at a farm. Salmonella typhimurium was isolated from a blood sample of a 6-day-old male cria that also died after a short illness.

Animals↗
PubMed1994

Leukocyte functions of young dairy calves fed milk replacers supplemented with vitamins A and E.

Holstein calves (n = 44) were fed milk replacers from d 3 to 45 with low or high concentrations of vitamin A (7000 or 87,000 IU/kg) and vitamin E (11.2 or 57 IU/kg) to examine the influence of vitamin concentrations on vitamin bioavailability and leukocyte functions. Concentrations of alpha-tocopherol in plasma reflected increased vitamin E but were unaffected by increased vitamin A. Plasma retinol concentrations were greatest with high supplementation of vitamins A and E at wk 3; however, at wk 6, plasma of calves fed high vitamin A and low vitamin E contained the most retinol. Increased supplementation of vitamin A improved fecal consistency compared with that for calves fed the low vitamin A diet at wk 3 and 4. At wk 3, calves that received increased supplementation of vitamins E and A had enhanced neutrophil bactericidal activity compared with that of calves with increased individual vitamins. Lymphocyte DNA synthesis and chemotactic index were unaffected by dietary treatments. Results indicate that increased vitamin A in milk replacer did not affect plasma vitamin E concentrations, benefited fecal scores regardless of vitamin E concentrations, but was only beneficial to bactericidal activity of neutrophils in conjunction with increased vitamin E.

Animal Feed↗
PubMed1994

Actinobacillus pleuropneumoniae in gnotobiotic piglets: ultrastructural changes in the pulmonary alveoli with dose and time.

The ultrastructural changes in pulmonary alveoli produced by transtracheal inoculation of 10(6) and 10(8) CFU of Actinobacillus pleuropneumoniae serotype 5 in gnotobiotic piglets were studied after 1 and 4 h. At 1 h postinoculation (p.i.) with 10(6) or 10(8) CFU, no gross change in lung and no evidence of infiltration of cells into alveoli was observed. At 4 h p.i., at a dose of 10(6) CFU, a generalized red mottling occurred in the dorsal half of the caudal lobe, which revealed ultrastructural evidence of neutrophil infiltration into alveoli along with fibrin and a few erythrocytes. At 4 h p.i., at a dose of 10(8) CFU, there was a bilateral lung lesion characterized by a generalized mottling and congestion, within which we observed ultrastructural evidence of bacteria and cellular debris in the alveoli and fibrin clots and cellular necrosis in the alveolar septum. By using gnotobiotic piglets and visualizing the effects of bacterial inoculum on cellular ultrastructure of the lung, we have demonstrated that both dose and time play roles in the early pathogenesis of experimental porcine pleuropneumonia. The developing lesion in lungs of gnotobiotic piglets infected with pure cultures of A. pleuropneumoniae can be controlled experimentally. This experimental procedure can provide a base of reproducible, sequential, ultrastructural changes with which to compare the role of inflammatory mediators in the lung and the effects of drugs on immunologic events in the lung.

Actinobacillus Infections↗
PubMed1993

Abdominal pain associated with an umbilical abscess in a llama.

A 3-month-old llama with a presenting complaint of lethargy, anorexia, and a painful, distended abdomen was evaluated. The llama had intermittently strained to defecate during the 3 days prior to admission. Physical examination results, hematologic data and lateral abdominal radiographs were used to diagnose a large umbilical abscess, which was causing a partial obstruction of the gastrointestinal tract. Under general anesthesia, 3 liters of purulent exudate were drained from the abscess. The abscess cavity was then lavaged with saline solution and its capsule was marsupialized to the skin. Cultures of the abscess content yielded Proteus sp, Streptococcus equisimilis, and Clostridium septicum. Two days after surgery, the llama was drinking, eating, and passing feces. The abscess was lavaged daily for a total of 11 days. Six months after surgery, the llama was the same size as other llamas of the same age, and the owners were pleased with the cosmetic appearance of the ventral abdomen. Umbilical abscesses can vary in size and clinical presentation; they should be recognized as a possible cause of abdominal pain with a potential for causing intestinal obstruction in llamas.

Abdominal Pain↗
PubMed1992

Response of young dairy calves with lasalocid delivery varied in feed sources.

Growth, age at weaning, fecal scores, and blood metabolites of young dairy calves were measured to determine the most effective method of lasalocid administration. Forty Holstein bull calves were blocked by date of birth and assigned randomly to one of four treatment groups: no lasalocid; lasalocid in starter; lasalocid in prestarter and starter; or lasalocid in milk, prestarter, and starter for a 12-wk period. Calves were fed milk twice daily until they consumed 227 g/d of prestarter, at which time the p.m. milk feeding was discontinued, and starter was offered for ad libitum intake as a mixture with the 227 g/d of prestarter. When total dry feed consumption reached 1.3% of birth weight, the calf was weaned. When the calf was 5 wk of age, the prestarter was discontinued. Daily gain tended to be greatest during the first 6 wk for the calves receiving lasalocid in milk, prestarter, and starter. These calves also were weaned with less variation in days to weaning. By wk 8 through 12, there were no differences in gain among the treatment groups.

Animal Feed↗
PubMed1992

Neutrophil and lymphocyte response to supplementation with vitamins C and E in young calves.

Calves, beginning at 3 d of age, were bottle-fed milk replacer unsupplemented, or supplemented with 10 g of vitamin C, or supplemented with 10 g of vitamin C plus 57 IU of vitamin E/kg of dry milk replacer (10 calves per treatment). Neutrophils from wk 2 and 4 blood samples were assayed for Staphylococcus aureus phagocytosis and neutrophil-mediated, antibody-dependent cellular cytotoxicity, and lymphocytes from those samples were assayed for concanavalin A-induced, phytohemagglutinin-induced, or pokeweed mitogen-induced proliferation. Ocular and nasal discharges of calves supplemented with vitamins C or C and E were less than those of controls for wk 1 to 8. Calves receiving supplementation with vitamin C and E tended to have higher mitogen-induced lymphocyte proliferative responses at wk 2. Neutrophil-mediated phagocytosis and antibody-dependent cellular cytotoxicity were lower at wk 2 and 4 for calves supplemented with vitamin C than for controls. Neutrophil function of calves supplemented with vitamins C and E together was near, or slightly higher than, that of unsupplemented calves for wk 2 and 4, suggesting that the addition of vitamin E negated the adverse effects that vitamin C alone had on neutrophil functions.

Animals↗
PubMed1991

The effects of stressful exercise on leukocytes in cattle with experimental pneumonic pasteurellosis.

Seven yearling bulls were treated with stressful exercise and intrabronchial Pasteurella haemolytica A1. Group 1 bulls (nos. 1-4) underwent treadmill exercise and, 24 days later, intrabronchial instillation of P. haemolytica A1. Group 2 bulls (nos. 5-7) underwent treadmill exercise, followed 30 min later by intrabronchial P. haemolytica A1. Blood lactic acid values were raised (p less than 0.05) by treadmill exercise only, but plasma cortisol was raised (p less than 0.05) by treadmill exercise and by P. haemolytica A1 infection. Neutrophils in bronchoalveolar lavage (BAL) differed from control values 24 h after treadmill exercise, and 1 h and 4 h after P. haemolytica A1 infection. Respiratory disease was more severe and the gross lung lesions were larger in group 2 bulls than in group 1 bulls. P. haemolytica A1 was recovered from the livers, spleens and mesenteric lymph nodes of group 2 but not group 1 bulls, suggesting that group 2 bulls had experienced bacteraemia. Decreased neutrophils in BAL fluid from group 2 bulls at 1 h and 4 h after infection suggests that exercise transiently inhibited neutrophil egress from the blood to the alveoli; BAL neutrophils peaked at 1 h and 4 h after infection in group 1 bulls but declined at 24 h. We conclude that group 2 bulls were made more susceptible to experimental pneumonic pasteurellosis by stressful exercise.

Animals↗
PubMed1991

Phagocytosis and erythrocyte antibody-rosette formation by three populations of mononuclear phagocytes obtained from dogs treated with glucocorticoids.

The effect of systemic administration of glucocorticoids was evaluated on 3 populations of macrophages obtained from healthy dogs. Phagocytic and Fc-receptor activities were determined for mononuclear phagocytes from blood and pulmonary and peritoneal lavage fluids. Samples were collected from 12 dogs before treatment and again on the same dogs after glucocorticoid administration. Thirty or more days were allowed between treatment periods. Twelve hours after combined prednisolone sodium succinate and dexamethasone sodium phosphate administration, the percentage of phagocytosing cells decreased for blood monocytes and increased for pulmonary macrophages. The percentage of pulmonary macrophages positive for erythrocyte antibody-rosette formation (Fc-receptor activity) increased. After 7 days of oral administration of prednisone, the percentage of phagocytosing peritoneal macrophages increased, whereas the percentage of blood monocytes with Fc-receptor activity increased. Results indicate that significant (P less than 0.05) changes in macrophage function occur after systemic administration of the glucocorticoid doses used in this study. Also, the effect of systemic administration of glucocorticoids on mononuclear phagocytes varies, depending on the specific cell location.

Animals↗
PubMed1989

Antibodies to Escherichia coli J5 core glycolipids in gnotobiotic and conventionally reared piglets.

Antibody titers to Escherichia coli J5 endotoxin core glycolipids were determined in 5-week-old, unvaccinated, conventionally reared and gnotobiotic pigs in a micro-ELISA. Both groups of pigs had naturally occurring antibody of all major isotypes. The conventionally reared pigs had significantly (P less than 0.05) more serum antibody to J5 endotoxin glycolipids (geometric mean titer, GMT = 2.07) than gnotobiotes (GMT = 0.85). This relationship was not necessarily true in fluids from various anatomical structures. In gnotobiotes, mucosal-associated, anti-J5 glycolipid immunoglobulin was primarily IgM. In conventionally reared piglets, the mucosal-associated, anti-J5 glycolipid antibody contained more IgA. Such naturally occurring antibody could confer partial to complete immunity from challenge with Gram-negative bacteria.

Animals↗
PubMed1988

Performance and ruminal changes of early-weaned calves fed lasalocid.

Twenty-two neonatal calves were assigned to a control or lasalocid-fed group and weaned at 3 wk of age. They were fed a prestarter diet from 3 d of age until they consumed 227 g/d and then a mixture of 227 g prestarter daily and starter diet in ad libitum amounts. The lasalocid-fed group received lasalocid in milk at 1 mg/kg body weight daily from 4 to 7 d and at .5 mg/kg body weight daily in milk and medicated prestarter diet (88 mg lasalocid/kg) during the 2nd wk. After 2 wk, lasalocid-fed calves were given medicated prestarter and starter (44 mg lasalocid/kg) diets. Four calves in each group were ruminally cannulated at 3 to 5 d of age, and ruminal contents were obtained at weekly intervals to monitor microbial activity. Rectal fecal samples were collected from all calves and examined for coccidial oocysts. Lasalocid-fed calves had a greater weekly feed intake and weight gain than control calves after 6 wk of age. Total ruminal volatile fatty acid concentrations were higher, but the acetate:propionate ratio was lower in lasalocid-fed calves than in control calves. Total viable anaerobic and amylolytic bacterial counts were higher in lasalocid-fed calves than in control calves. No significant treatment effect was found for ruminal NH3-N concentration or ruminal lasalocid-resistant, lactobacilli, lactate-utilizing, cellulolytic or methanogenic bacterial numbers. No evidence of coccidiosis was detected in either group. In general, lasalocid-fed calves had greater feed intake, weight gain and ruminal microbial activity than the calves fed no lasalocid in the diet.

Animals↗
PubMed1985

Mononuclear phagocytes of transport-stressed horses with viral respiratory tract infection.

Twelve horses comprised 3 treatment groups; all horses in 2 of the groups had recently been transported and had clinical and laboratory evidence of respiratory tract infection, with equine influenza type 2 virus being the principal pathogen. Mononuclear phagocytes and other leukocytes from blood, lung, and peritoneal cavity were studied in phagocytosis and erythrocyte-antibody (EA) rosette assays. Total numbers of pulmonary alveolar macrophages were increased over control values in bronchoalveolar lavage (BAL) fluid of group 3 horses after recovery from influenza (P less than 0.02), whereas the increase in neutrophils in the fluid of those horses approached significance. Lymphocytes in BAL fluid of group 3 horses (after recovery from influenza) were in larger proportion than those in fluid of group 1 horses during acute influenza (P less than 0.05). Pulmonary alveolar macrophages of group 1 horses formed a lower percentage of EA rosettes than did those of controls (P less than 0.01) or group 3 horses (P less than 0.02). The differential counts of peritoneal macrophages and neutrophils in horses of groups 1 and 3 were virtually identical at the first collection, but differed from controls at the second collection 4 weeks later; peritoneal macrophages were reduced (P less than 0.01), whereas peritoneal neutrophils were increased (P less than 0.01). Peritoneal macrophages and peritoneal neutrophils of horses with acute influenza were phagocytic in larger proportion than were those in controls at both collection times (P less than 0.01 and P less than 0.01 for peritoneal macrophages, and P less than 0.01 and P less than 0.05 for peritoneal neutrophils, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Isolation and functional analysis of normal canine blood monocytes and resident alveolar macrophages.

The percentage of mononuclear phagocytes bearing the Fc receptor for immunoglobulin G, the percentage of cells phagocytic for Candida albicans and latex particles, and the phagocytic index for blood monocytes and alveolar macrophages from healthy dogs are reported. Blood monocytes were concentrated by density-gradient centrifugation, whereas alveolar macrophages were obtained in high yield by bronchoalveolar lavage. Adherent populations of those cells were used for functional assays after repeated washing to remove nonadherent cells. A greater percentage of adherent alveolar macrophages than adherent blood monocytes showed evidence of the Fc receptor for immunoglobulin G. Similarly, adherent alveolar macrophages showed significantly greater phagocytic ability, as measured by percent phagocytic cells and phagocytic index, using C albicans and latex particles, than did adherent canine blood monocytes.

Animals↗