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Biomedical subjects

J G Ross

Publications and source records attributed to J G Ross.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of sodium thiosulfate as an extracellular water marker in cattle.

Two studies were conducted to determine whether sodium thiosulfate (THS) can estimate extracellular water (ECW) in beef cattle in conjunction with empty body water (EBW) estimation by urea space. Experiment 1 used 24 steers (366 kg) to determine the clearance parameters for THS and urea. Blood samples were taken over 1 h. A two-component curve, Y = A1ek1(t) + A2ek2(t), (t = hours after infusion) fit the clearance of both markers; intercepts (A1, A2) and clearance coefficients (k1, k2) were 44.8, 44.4, -25.8, and -2.24 mg/dL, respectively, for THS (r2 = .98, Sy.x = 2.72, animal effects removed and 24.4, 10.5, -21.7, and -.71 mg/dL, respectively, for urea (r2 = .98, Sy.x = 1.49). Sodium thiosulfate equilibrated with ECW 5 to 10 min after infusion. Experiment 2 consisted of 22 steers (483 kg) infused with a combination solution of 20% urea, 10% THS, and 4% sodium thiocyanate (SCN; equilibration time = 28 min); half the steers were implanted with estradiol. Empty body water increased with implantation (P less than .01). Extracellular water tended to increase in implanted steers as measured by THS (12 min, P = .14) and SCN (P = .10). The estimation of ECW at 12 min was not different (P greater than .2) from the SCN estimate at 28 min (SCN = 3.7 + .873 THS; r2 = .70; P less than .001). Sodium thiosulfate gave reasonable estimates of ECW (22 to 26% of BW) and required only 0- and 12-min blood samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Associations between physical activity and physical fitness in American children.

Associations between two measures of physical fitness, 1.6-km run/walk performance and sum of three skinfold thicknesses, and selected physical activity factors were studied in a nationally representative sample of third- and fourth-grade students (1150 boys, 1202 girls). Twenty physical activity variables measured via parent and teacher questionnaires were factor analyzed, and for each of the resultant eight factors, individual factor scores were generated. These were used in two multiple regression analyses in which 1.6-km run/walk time and sum of skinfold measurements were the dependent variables. Multiple R2 for these two analyses were .21 and .18. Significant factors in both analyses were global ratings of the child's activity level, age, vigorous community activities, and gender. The results indicate that physical activity and physical fitness are significantly, although moderately, associated in young children and suggest that interventions directed toward enhancement of physical activity in children are worthy of investigation.

Child↗
PubMed1987

Physical education and its role in school health promotion.

In this article, the authors promote the concept of health-oriented physical education, discuss professional standards, examine the current status of physical education programs, and discuss trends affecting physical education. Recommendations to make physical education more effective are provided.

Child↗
PubMed1979

Investigations of 'transfer factor' activity in the transfer of immunity to Trichostrongylus axei infections in sheep.

Three investigations are described in which non-dialysed and dialysed leucocyte lysates, 'transfer factor' prepared from the blood of sheep infected with Trichostrongylus axei successfully transferred immunity to challenge infection with that parasite in susceptible lambs. Similar leucocyte lysates from parasite-free lambs failed to transfer a similar resistance to challenge infection. 'Transfer factor' treatment produced a 30--72 per cent reduction in a total worm burden compared to susceptible control lambs. In the first two investigations the donor and recipient lambs were genetically dissimilar and in the third investigation were of different breeds. The resistance transfer was considered to operate independently of immune incompetence.

Animals↗
PubMed1979

Investigation of Haemonchus contortus infections in sheep. Comparison of irradiated larvae and transfer factor treatment.

A comparison is made between the resistance conferred to Haemonchus contortus challenge by irradiated larval treatment and transfer factor (TF) treatment in four-month-old lambs and seven-month-old lambs. As in previous investigations the irradiated larval treatment failed to confer resistance to the four-month-old lambs challenged with 10,000 third stage larvae while similar irradiated larval treatment in seven-month-old lambs reduced the worm burdens by 40 per cent compared to controls. The TF treatment produced a 34 per cent reduction in the challenge infection in the four-month-old lambs and a 45 per cent reduction in the seven-month-old lambs compared to the control lambs. It is concluded that TF activity operates independently of immune competence.

Animals↗
PubMed1978

Haematological and blood chemistry "comparison values" for clinical pathology in poultry.

Twelve blood chemistry values, six haematological values and bodyweight were estimated for six-week-old specific-pathogen-free brown leghorns. Observations were based on 208 birds sampled from 11 groups. Subsequently the same values were estimated for specific pathogen free brown leghorns and broiler hybrids of differing ages. These estimates have been designated "comparison values" and were intended for reference use in clinical pathology. Results were compared with 14 "comparison value" estimated obtained previously for six-week-old commercial broiler hybrids. Haematological values varied with age and type of bird. Differences were observed between bird types in serum protein, serum cholesterol, uric acid, calcium and potassium levels and in weight. The significance of these differences is discussed.

Age Factors↗
PubMed1977

Effect of transportation on blood metabolites in broilers.

1. Groups of 30 broilers from seven flocks were bled and weighed at the farm and a further sample of 10 broilers from each flock was transported from 8 to 16 km to the laboratory prior to bleeding and weighing. 2. One haematological and 11 biochemical analyses were made on each blood sample. 3. Although transportation did lead to significant differences in certain variables, the trends were consistent and sampling following transit is considered acceptable for clinical pathology studies.

Animals↗
PubMed1976

Experimental infections of sheep with Salmonella typhimurium.

Twenty-two-six-to nine-month-old lambs were infected orally with Salmonella typhimurium at levels varying from 2 x 10(13) to 1 x 10(9) and serially slaughtered to determine the pathogenesis of infection and to evaluate the efficacy of diagnostic procedures. Infection resulted in a severe fatal or potentially fatal clinical disease in lambs receiving 2 x 10(13) organisms. Observations were made on the clinical pathology, bacteriology and serology during the course of infection and extensive bacteriological examinations were undertaken at autopsy.

Animals↗
PubMed1976

Experimental infection of poultry with Salmonella infantis.

Six-month-old cockerels and point-of-lay pullets were infected orally with S infantis (1 X 10(10). The cockerels were slaughtered at intervals up to 42 days, and the pullets slaughtered 20 weeks, after infection. Infection produced no clinical disease and minimal changes were observed at autopsy. Serological responses were transient, frequently absent three to six weeks after infection, no response at all being recorded in some birds. Faecal excretion was observed most frequently during the early stages of infection. There was no evidence of egg transmission.

Animals↗
PubMed1975

Experimental infection of cockerels with Salmonella typhimurium.

Six-month-old SPF Brown Leghorn cockerels were experimentally infected per os with S typhimurium (1 times 1010) and slaughtered at intervals up to 42 days following infection. Observations were made on the clinical pathology, bacteriology and serology during the course of infection and extensive bacteriological examinations were undertaken after post mortem examination.

Administration, Oral↗