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Biomedical subjects

T Reilly

Publications and source records attributed to T Reilly.

At least 181 records · Page 10Linked to original sources
PubMed1981

Ergonomic aspects of sport and recreation.

Human factors engineering or ergonomics originated in military technology from the team-work of engineers and specialists in the human sciences. The central focus is on the human operator upon whom the task and environment impose specific loadings. Intransigence of task demands in sport tends to shift emphasis to training and selection. Heredity seems to play the more important role in the evolution of the champion athlete. An integrated interdisciplinary approach is advocated in assessing task demands and individual capacity to meet them. Improving equipment and facility design promotes safety and performance efficiency. Environmental stresses may be simulated in laboratory conditions to provide opportunity for prior adaptation. Stresses associated with urbanized civilization present novel risks to social health. Quality of life can be enhanced from an ergonomics input into the design of sports facilities and exercise programmes and their subsequent monitoring.

Aerobiosis↗
PubMed1980

Uncoupling of the glucagon receptor-adenylate cyclase system by glucagon in cloned differentiated rat hepatocytes.

The ability of glucagon to induce a state of desensitization to glucagon responsiveness has been examined in a cloned line of normal, differentiated, diploid rat hepatocytes (RL-PR-C). These cells, which respond to glucagon with increased production of cyclic AMP, become refractory to further stimulation of cyclic AMP synthesis following a 4 hour exposure period of the cells to the hormone. Refractoriness to glucagon was demonstrated over a wide range of hormone concentrations (10(-12) to 10(-6) M). In desensitized cells that were subsequently washed free of the hormone, recovery from refractoriness was complete by 20 hours. The mechanism underlying this desensitization does not appear to involve decreased receptor numbers, increased efflux of cyclic AMP from the cells, increased degradation of cyclic AMP by phosphodiesterase, or an alteration in the catalytic unit of the adenylate cellular cyclic AMP responsiveness to glucagon in normal RL-PR-C hepatocytes may involve glucagon a reversible uncoupling of glucagon receptors from adenylate cyclase. In addition, late passage, spontaneously transformed RL-PR-C hepatocytes were found to exist in a state in which glucagon receptors are permanently uncoupled from adenylate cyclase.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1979

Fitness test profiles and trainng intensities in skilled race-walkers.

A broad profile of national standard race-walkers was obtained. Subjects were taller and had more body fat than competitive runners of comparable distance as found in the literature. Pulmonary function, blood pressure and maximal heart rates were similar to normal sedentary values. The group's somatotype was 2.5 : 3 : 4, low mesomorphy being reflected in inferior strength measures. Haematological status corresponded to the runners of Brotherhood et al (1975). Predicted VO2 max (x = 70 ml kg min-1) was not related to performance. Time to exhaustion on a treadmill test correlated with 20 km race time (R = -.94; p less than .001). Multiple regression equations derived to predict race performance from combinations of 4 to 6 personality traits were non-significant. Mean heart rate in typical training regimes was 167 beats min-1 for interval training at 13 kmh-1 on the track and 134 beats min-1 over a 2.1 h road walk at 10.3 kmh-1. Physiological strain was greater in uphill than in level or downhill walking (P less than .001).

Adolescent↗
PubMed1979

Fitness assessment of English league soccer players through the competitive season.

A battery of 26 tests was administered to professional soccer players (n = 31) at 3 points during the competitive season. Significant changes from start to mid-season were limited to improved muscular power, increased resting heart rate (fH), decreased force expiratory flow (FEF) and ankle mobility. No further changes with the duration of the competitive season were observed. Differences between squads were predominantly cardiac function measures at mid-season, and strength, muscular power and limb girths at the end of the season. The First Team squad had consistently less fat and poorer ankle mobility. It seems that mean fitness levels remain relatively stable during the playing season, though the measures significantly discriminating between the top and reserve squads fluctuate.

Adolescent↗
PubMed1978

Insulin action on Escherichia coli. Regulation of the adenylate cyclase and phosphotransferase enzymes.

Insulin on Escherichia coli was studied using wild type E. coli B/r and K12 strains and a number of phosphoenolpyruvate phosphotransferase mutants. In vivo, the effects of insulin on the differential rate of tryptophanase synthesis, the rate of alpha-methylglucoside uptake and the rate of growth on glucose were determined in E. coli B/r. In vitro, the effect of insulin on the adenylate cyclase and the phosphotransferase activities was determined using toluenized cell preparations of E. coli B/r, E. coli K12 and phosphotransferase mutant strains. The specificity of insulin action on E. coli was determined using glucagon, vasopressin and somatropin as well as insulin antisera. Results show the specific action of insulin on E. coli, inhibiting tryptophanase induction and adenylate cyclase activity, while stimulating growth on glucose and uptake and phosphorylation of alpha-methylglucoside.

Adenylyl Cyclases↗
PubMed1978

Multi-station equipment for physical training: design and validation of a prototype.

The design of a prototype multi-station exercise machine is described. Resistance models and muscle groups used varied between stations which were constructed to accommodate a wide range of individual differences. The apparatus was validated using time-motion analysis, anthropometry, subjective user responses and physiological methods. Problems at the man-machine interface were identified, and risk and discomfort factors minimised. The equipment is recommended for use both to athletes for specific conditioning and to recreational users for endurance and strength training.

Journal Article↗
PubMedDate not supplied

Changes in plasma lipids and lipoproteins following 10-days of prolonged walking: influence of age and relationship to physical activity level.

The aim of the present study was to examine (1) the influence of 10 days of prolonged walking on plasma total-cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) concentrations, (2) the effect of age on any changes in plasma cholesterol and lipoprotein concentration, and (3) whether any changes in cholesterol and lipoprotein concentrations are correlated to the participants' physical activity level (PAL). Seventeen male participants were divided into two groups according to their age. The nine participants in group 1 constituted the younger group (age 24 +/- 3 (SD) years), whereas eight older participants were in group 2 (age 56 +/- 3 years). Both groups completed 10 consecutive days of high-intensity hill walking. Mean (range) daily distances and ascent were 21 km (10-35 km) and 1,160 m (800-2,540 m), respectively. Identical distances and ascents were covered by each group. For each participant, PAL was calculated from energy expenditure, assessed by the doubly-labeled water technique, divided by the individual's basal metabolic rate. Venous blood was sampled immediately prior to, and following, the 10 consecutive days of walking. Following these 10 days, the older group showed a greater decrease in both TC (-25 +/- 11% vs. -10 +/- 11%; P < 0.05) and LDL-C (-26 +/- 12% vs. -4 +/- 13%; P < 0.05) when compared with the young. Likewise, the older group showed a greater increase in HDL-C (38 +/- 15%; P < 0.05), after the 10 days, whereas no significant change was evident in the younger group. In the older participants, there were strong positive relationships between PAL and the decreases in TC (r = 0.79, P < 0.05) and LDL-C (r = 0.74, P < 0.05). Conversely, in the younger group there were strong negative relationships between PAL and the decreases in TC (r = -0.74, P < 0.05) and LDL-C (r = -0.86, P < 0.01). These correlations persisted when changes in lipid concentrations were corrected for changes in plasma volume. These data suggest an 'age-dependant' threshold for PAL, rather than a specific exercise intensity or duration, may be critical for inducing favourable changes in HDL-C, LDL-C and TC.

Adult↗