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1.  Effect of prolonged exercise of serum testosterone levels in adult men. 
The purpose of the study was to: 1) identify the differences in serum testosterone levels among four groups of adult men differentiated on the basis of physical fitness and age, and 2) determine the effect of a four-month physical fitness programme consisting of running, calisthenics and recreational activities on the serum testosterone levels of the four groups. The groups were designated: high-fit, young aged about 32 (n = 7); high-fit, old aged about 52 (n = 7); low-fit, young (n = 7), and low-fit, old (n = 7). The subjects were selected and grouped according to physical fitness scores obtained using the regression equation of Ismail et al. Serum testosterone was determined by a radioimmunoassay method. The pre-test ANOVA revealed that the high-fit groups had a significantly (p less than .01) higher testosterone level (754.29 ng/100 ml) than the low-fit groups (548.07 ng/100 ml) and the high-fit, young group (925.01 ng/100 ml) was significantly (p less than .01) higher than the other three groups. Post-test values were adjusted using pre-test testosterone values as covariates. No significant differences among the groups were found indicating that the serum testosterone levels were the same regardless of different ages and fitness levels. The findings were discussed in light of physiological, biochemical and psychological factors.
PMCID: PMC1859523  PMID: 1009301
2.  Energy expenditure and physiological performance of Sudanese cane cutters. 
The thermal and exercise tolerances of 165 Sudanese cane cutters were measured in the laboratory and related to work performance and productivity in the cane fields. The results showed that the amount of cane cut per minute in the field was significantly correlated with changes in body weight (r = +0-53) during the third hour of work, aerobic energy expenditure (r = + 0-43), and cardiac frequency during work. These variables in turn were associated with predicted maximal power output (VO2 max) measured in the laboratory. The average energy expenditure during cane cutting was 1-66 +/- 0-33 1/min-1 (34-9 kJ/min-1) which represents approximately 60% of the workers predicted VO2 max. This rate of energy expenditure was sustained in the cane fields for at least three hours without significant pauses for rest. The sweat losses measured in 32 cane cutters during the two and three hours of work averaged 637 +/- 221 and 770 +/- 282 g/h-1 respectively, while the mean urine temperature immediately on cessation of effort was 37-74 +/- 0-46 degrees C. Despite the additional environmental heat load of the tropics, it would seem that cane cutters performing a self-paced task demanding heavy physical effort, are able to sustain work levels well in excess of those recommended for most European factory workers without obvious signs of fatigue or heat stress.
PMCID: PMC1008132  PMID: 963003
3.  The distribution of serotypes of Escherichia coli in cow-pats and other animal material compared with serotypes of E. coli isolated from human sources. 
The Journal of Hygiene  1976;76(3):403-406.
The serotypes of 13,139 strains of Escherichia coli isolated from humans were compared with the serotypes of 1076 strains isolated from animals. 689 of these strains were isolated from fresh cow-pats on 22 sites in England and Wales. 708 different O/H combinations were found. Of these, 520 were found in human strains only, 130 from animal strains only and 58 O/H serotypes from humans and animals. Approximately half of the animal strains could not be typed with the full set of sera used.
PMCID: PMC2129671  PMID: 778259

Results 1-3 (3)