Biomedical subjects

T G Martin

Publications and source records attributed to T G Martin.

At least 55 records · Page 3Linked to original sources

PubMed1982

Failure of peak expiratory flow rate to predict hospital admission in acute asthma.

Our study evaluated the ability of early peak expiratory flow rates (PEFR) to be predictive of hospital admission while double blinding the measurements and using a standardized treatment protocol and specific admission criteria. The measurements were recorded prior to and after initial therapy. Eighty-six acute asthmatic episodes in 51 patients were analyzed. Nine (10.5%) of the episodes resulted in hospitalization; 77 (89.5%) resulted in discharge. No correlation with admission was found for the initial PEFR, a second PEFR following treatment, or the differences between these two values. Our study indicates that early PEFRs alone are not useful predictors of the need for hospital admission. Although a significant number of patients in our study population presented with severe airflow obstruction, they responded sufficiently to treatment to permit discharge.

Acute Disease↗

PubMed1982

Use of peak expiratory flow rates to eliminate unnecessary arterial blood gases in acute asthma.

Arterial blood gas (ABG) measurements are used frequently in acute asthma. Because ABGs are expensive and may have significant side effects, a method is needed to identify those patients at risk for a significantly abnormal ABG. We studied the use of peak expiratory flow rates (PEFR) to identify those patients at such risk. Data from 89 emergency visits by 51 asthmatic patients were analyzed. A small but significant correlation between ABG parameters and PEFR was observed (P less than 0.05). No patient with a PEFR greater than or equal to 25% predicted has a PaCO2 greater than 45 mm Hg or pH less than 7.35. This suggests that only those patients with a PEFR less than 25% predicted are at risk for significant hypercarbia or acidosis. We concluded that PEFR may be used as a simple screening tool to safely eliminate ABGs in at least 40% of acute asthmatic patients.

Acute Disease↗

PubMed1981

Mature weight, maturation rate, maternal performance and their interrelationships in purebred and crossbred cows of angus and milking shorthorn parentage.

Mature weight, maturation rate and lifetime maternal performance, through a maximum of seven calving seasons, were analyzed for 182 cows of Angus (A) and Milking Shorthorn (S) breeds and the two reciprocal crossbred groups. Mature weight and rate of maturation were estimated for the three-parameter growth curve described by Brody. Estimates derived for mature weight (kilograms), both unadjusted and adjusted for cow condition, were, respectively: Angus, 421, 407; Shorthorn, 409, 459; A x S, 448, 455 and S x A, 440, 441 (approximate standard error, 8 kg). Estimates for the maturation rate parameter were, respectively: Angus, 5.8, 6.3; Shorthorn, 6.6, 5.4, A x S, 6.2, 6.1 and S x A, 5.9, 6.1%/month (approximate SE, .3%/month). Heterosis for mature weight was 3 to 7% (28 +/- 8 and 15 +/- 6 kg, respectively). No heterosis was observed for the maturation rate parameter. Birth weight (.048 +/- .025 kg/kg) and weaning weight (.142 +/- .044 kg/kg) of the first calves were positively related with mature size of the dam. Weaning weights of first calves increased with increasing rate of maturation of the dams (3.6 +/- 1.5 kg/percentage/month) while birth weights remained unchanged. Under the culling criteria used in this study, the number of calves produced by a cow in her lifetime decreased (-.007 +/- .003 calves/kg) with increasing mature weight, while average weaning weight of the calves increased (.132 +/- .03 kg/kg). Total weight weaned, years in the herd and weight weaned per year tended to decrease (P greater than .05) with increasing mature weight of dam, but not significantly. Positive heterosis was expressed for all lifetime cow productivity characters, with crossbred cows weaning 22% (230 +/- 57 kg) more calf weight in their lifetime.

Animals↗

PubMed1981

Estimation of genetic and maternal effects in crossbred cattle of Angus, Charolais and Hereford parentage. III. Optimal breed composition of crossbreds.

Methods for estimating genetic and maternal effects in crossbred populations were extended and generalized to allow estimation of optimal breed combinations. Coefficients of the effects were expressed in terms of the probabilities of obtaining genes from a given parental breed through the sire (PiS), dam (PiD) and maternal grandsire (píS). The formulas are applicable to crosses involving any number of breeds. For purposes of graphic presentation, available genetic and maternal parameters for 205-day weight derived from data involving the Angus (A), Charolais (C) and Hereford (H) breeds were used to develop response surfaces for all two-breed combinations of the A, C and H breeds. PiS, PiD and PíS ranged from 0 to 1. In crosses involving varying proportions of the A and C or the H and C breeds, an increased proportion of C genes resulted in increased 205-day weight, and the shape of the performance surface was largely determined by the breed additive effects of the C breed. Individual and maternal heterosis effects influenced the shape of the performance surface of crosses involving varying proportions of A and H. Application of results to the formation of synthetic breeds is discussed.

Animals↗

PubMed1980

Effects of winter and summer energy levels on heifer growth and reproductive performance.

Three heifer development trials were conducted with 337 crossbred heifers (125, 105 and 107 heifers in trials 1, 2 and 3, respectively) over a 3-year period. Heifers were fed low quality fescue hay ad libitum plus 0, 1.22 or 2.45 kg of ground ear corn (GEC) daily during the winter feeding phase of all three trials. Winter gains and final winter and summer condition scores increased (P less than .05) in each trial as winter level of GEC increased. In each trial, summer gains followed the reverse order of winter gains (P less than .05). Conception rate, mean number of days pregnant (as determined by rectal palpation) and adjusted weaning weight of progeny increased linearly with winter level of GEC when pooled over trials. Differences between animals fed 0 and 2.45 kg of GEC were significant. Conception rate and adjusted weaning weight of progeny of the heifers retained in the breeding herd increased (P less than .05) as level of GEC increased when data were pooled over trials. Calving date and percentage live progeny were not significantly affected by winter treatment. Summer daily gains and condition scores were increased by additional summer energy (2.45 kg GEC/day) in trial 3. Conception rate and mean number of days pregnant (conception date) favored heifers given the summer supplementary feeding (2.45 kg GEC) treatment. Among heifers retained in the breeding herd, there were no significant differences between the 0- and 2.45-kg GEC summer treatment groups in conception rate, calving date, percentage live progeny or adjusted weaning weight of progeny.

Animals↗

PubMed1979