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Biomedical subjects

J G Ross

Publications and source records attributed to J G Ross.

At least 37 records · Page 2Linked to original sources
PubMed1994

Dietary electrolyte balance effects on performance and metabolic characteristics in growing steers.

The effects of dietary electrolyte balance (DEB; mEq of Na + K - Cl/100 g of DM) on performance and acid-base status of growing cattle consuming a corn silage-based diet were established using 120 Angus (n = 60) and Angus crossbred (n = 60) steers (247 +/- 2.4 kg). Treatments consisting of 0, 15, 30, or 45 mEq of DEB/100 g of DM were obtained by varying NH4Cl and NaHCO3. Average daily gain showed a linear increase (P < .05) with increased DEB for the first 28 d and a quadratic response (P < .05) for the remainder of the 84-d study. Average daily feed intake was not affected by DEB the first 28 d. However, feed intake over the entire feeding period showed a linear increase with increasing DEB (P < .01). On d 28, plasma Na, K, and Mg were not affected by DEB, whereas Ca followed a quadratic pattern (P < .10). On d 84, plasma Na and Mg decreased linearly with increasing DEB. Plasma Cl concentrations decreased linearly (P < .01) with increased DEB on d 28 and 84. On d 28 arterial blood pH and HCO3 increased linearly (P < .05) with increased DEB, whereas ionized Ca, pCO2, and pO2 were unchanged. On d 84, arterial blood pH (P < .10), HCO3 (P < .05), and ionized Ca (P < .10) increased quadratically, whereas pO2 and pCO2 were not affected by treatment. Ruminal pH increased linearly (P < .05) with increased DEB on d 28 but showed no differences on d 84. These data indicate that DEB affects performance and systemic values in growing feedlot cattle. A DEB in the range of 15 to 30 mEq seemed to provide normal homeostasis of growing steers fed a corn silage-based diet.

Acid-Base Equilibrium↗
PubMed1993

Acute and late reactions to radiation therapy in patients with collagen vascular diseases.

BACKGROUND: A commonly held belief is that patients with collagen vascular diseases (CVD) have a greater risk of radiation therapy complications than patients without CVD. This impression is based on anecdotal reports, however. METHODS: A group of 61 patients with CVD were compared with a matched control group of 61 patients without CVD. The CVD group included 39 patients with rheumatoid arthritis (RA), 13 with systemic lupus erythematosus (SLE), 4 with systemic sclerosis (scleroderma) (SSc), 4 with dermatomyositis, and 1 with polymyositis. The control group was matched with respect to age, sex, tumor site and histologic characteristics, treatment aim, general treatment method, radiation therapy technique, site irradiated, radiation dose, date of treatment, and follow-up. RESULTS: Overall, there was no significant difference between the CVD and control groups in terms of acute (11% versus 7%, respectively) or late complications (10% versus 7%, respectively). This was also true when only patients who were treated definitively were considered. Furthermore, none of the patients treated palliatively had complications. Three patients in the CVD group had fatal complications, compared with none in the control group. RA was associated with a slight increase in late complications in the definitively treated patients, whereas SLE was associated with a slight increase in acute reactions. No significant acute or late reactions were observed in the patients with SSc, dermatomyositis, or polymyositis. CONCLUSIONS: In general, these differences are less than expected and not statistically significant. Consequently, from these data, the authors could not show a significant increase in radiation therapy complications for patients with CVD.

Adult↗
PubMed1993

Validity of field tests of upper body muscular strength.

The purpose of this study was to determine the validity of five field tests (FTs) of upper body muscular strength and endurance (UBMSE) in 9-10-year-old children. Ninety-four children (38 boys, 56 girls) performed five FTs of UBMSE: pull-ups, flexed arm hang, push-ups, Vermont modified pull-ups (VMPU), and New York modified pull-ups. They also performed three criterion tests (CTs) of strength and three CTs of muscular endurance using a supported weight, set-resistance device. Zero-order correlations between the sum of the standard scores on the three CTs of strength (SUM1RM) and the FTs were nonsignificant. However, when SUM1RM was expressed relative to body weight (SUM1RM.kg-1), significant (p < .01) correlation coefficients were obtained for each FT. Highest correlations with SUM1RM.kg-1 were observed for the VMPU, and this same test yielded the smallest percentage of zero scores. Principal components analysis of the CTs, normalized for body weight, and FTs yielded a factor on which both the FTs and CTs of strength loaded significantly. These data indicate that the five FTs, though invalid as measures of absolute strength and muscular endurance, manifest concurrent and construct validity as measures of weight-relative muscular strength.

Arm↗
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↗
PubMed1984

The effect of transfer factor treatment on two challenge infections of Haemonchus contortus in immuno-competent 7-month-old lambs.

A number of immuno-competent Blackface lambs were infected with 10,000 Haemonchus contortus third stage larvae and were later challenged with a second dose of 10,000 H. contortus third stage larvae. One group of lambs was treated with dialysed transfer factor prior to the second challenge dose. Histological changes in the abomasal wall, reductions in abomasal worm burdens at slaughter and faecal egg counts monitored throughout the experiment suggested the presence in some animals of an innate resistance, a "self curing" effect, an enhancement of this "self curing" effect in the transfer factor treated group and a response in one transfer factor treated animal comparable to "classical self cure".

Abomasum↗
PubMed1983

A comparison of the effects of dialysed and non-dialysed transfer factor preparations on Haemonchus contortus infections in young lambs.

Significant reductions in worm burdens were achieved in lambs treated with dialysed transfer factor and challenged with 10,000 Haemonchus contortus larvae, when compared with challenged control animals. Non-dialysed transfer factor, from the same leucocyte pool, produced no protection, but was successful in reducing worm burdens when given after a primary infection of 1,000 H. contortus larvae with subsequent challenge of 10,000 larvae. While the results confirmed the previously reported inconsistencies of transfer factor activity, the histological abomasal changes in all the dialysed and non-dialysed transfer factor treated groups, irrespective of measurable effects on worm burdens, were consistent and corresponded to immediate type hypersensitivity responses. The similarity of these responses with self cure in haemonchosis and the possibility of genetic factors influencing the quantitative expression of protection to the effects of transfer factor treatments is discussed.

Abomasum↗
PubMed1983

The effects of transfer factor, parasitic antigen and precipitated immunoglobulin treatments in lambs infected with Haemonchus contortus.

Significant reductions in adult worm burdens in lambs less than six months old infected with 5000 third stage Haemonchus contortus larvae were achieved following the combination of a single transfer factor treatment with multiple parenteral treatments of adult parasitic antigen and precipitated immunoglobulin. Specific cellular responses in the abomasa associated with individual treatments were discernible in all the experimental groups and quantitative differences in these responses reflected the varying treatment levels and treatment combinations. The reactions associated with transfer factor were similar to immediate type hypersensitivity responses and their role as possible effector mechanisms in correcting partial immune incompetency in lambs is discussed.

Abomasum↗
PubMed1982

Investigations of transfer factor activity in resistance to Trichostrongylus colubriformis infections in guinea-pigs.

Resistance to challenge infection with Trichostrongylus colubriformis was studied in an outbred strain of guinea-pigs. Resistance was conferred by previous infections of 50 or 100 infective larvae and by intraperitoneal, intramuscular and subcutaneous administration of dialysed transfer factor prepared from guniea-pigs infected with T. colubriformis, by intraperitoneal administration of transfer factor prepared from the blood of sheep infected with T. colubriformis and on one of three occasions using transfer factor prepared from guinea-pigs which had not been infected with T. colubriformis. No significant resistance was transferred by administration of antigen prepared from adult T. colubriformis, or by non-dialysed transfer factor, or by dialysed transfer factor prepared from T. colubriformis-infected guinea-pig tissue which had been stored for several months at - 20 degrees C.

Animals↗
PubMed1981

Passive transfer of immunity to trichostrongyle species infections in sheep. Investigations of specificity and limitations of 'transfer factor' activity with Trichostrongylus axei infections.

The ability of transfer factor (TF) preparations to transfer resistance to challenge with Trichostrongylus axei in sheep and to correct partially the immune immaturity of young lambs was confirmed. Non-dialysed TF consistently transferred resistance but dialysed TF frequently failed, perhaps demonstrating a loss of activity during TF preparation procedures. Specificity of transfer was demonstrated when T. axei TF transferred resistance to T. axei challenge but Haemonchus contortus TF failed to do so.

Animals↗
PubMed1981

Successful passive transfer of resistance to Fasciola hepatica infection in rats by immune serum and transfer factor.

Resistance to Fasciola hepatica was shown by a 64 per cent reduction in fluke recovery compared with control rats was recorded in rats inoculated with serum from sheep experimentally infected with F hepatica. A comparable reduction (55.6 per cent) was obtained using transfer factor prepared from lysed leucocytes of infected rats. No significant reduction was obtained using transfer factor prepared from sheep or calves.

Animals↗