Pilot study of objective cough monitoring in infants.

Cough is common in childhood, resulting in significant morbidity and frequent medical consultation. Despite this, little is known about the frequency or development of cough, particularly in infants and young children. Recent progress in monitoring has enabled cough to be measured objectively both day and night. However, to date, objective measurement has only been used in adults and older children. The aim of this study was to see whether such methods could be extended to allow objective cough monitoring in infants. Thirty infants were recruited: 13 with coughing illnesses (group 1), and 17 normal, healthy babies (group 2) born to nonatopic, nonsmoking parents. Group 2 infants were studied when well, several times in the first year of life. Coughs were recorded using an adapted commercial cough monitor (Logan Research LR100) and simultaneous infrared video and sound recording. Thirty-eight recordings with simultaneous cough monitor and video data were analyzed: 9 from group 1, and 29 from group 2. Overall, the sensitivity of the monitor when compared to video was 81%, with a positive predictive value of 0.8. There was good agreement between the two methods for infants with infrequent cough (<5 coughs per hour). Agreement in infants with more frequent cough was not as good, because more coughs were consistently identified by the cough monitor. The portability and small size of the cough monitor made it easy to use, although there were difficulties in keeping the leads attached in older, more mobile infants. In conclusion, objective assessment of cough is practical in infants, enabling the pattern of cough in illness and in health to be studied further.

Tuberculosis in children at the Royal Hospital for Sick Children, Glasgow. January 1995-April 1998.

BACKGROUND: The management of paediatric tuberculosis can be complicated. Since 1995, children referred to the Royal Hospital for Sick Children have been managed at a specialist tuberculosis clinic, in an attempt to standardise diagnosis, treatment and follow-up. AIMS: To review the management of paediatric tuberculosis at the Royal Hospital for Sick Children, Glasgow, from January 1995 to April 1998. METHODS: Retrospective study using information from the management database of all children treated for tuberculosis since January 1995. RESULTS: Seventy two children have been treated (median age 5.9 [range 2.2-9.2] years; sex male:female 40:32; 76% Caucasians): 43 for tuberculosis disease, 21 for tuberculosis infection (chemoprophylaxis) and eight as tuberculosis contacts. Sixty three per cent were identified by contact tracing eighty one per cent of Mantoux tests were documented accurately. Of those with disease, 93% had gastric washings taken, and positive microbiological confirmation was obtained in 33%. All patients with disease were commenced on the chemotherapy regimen recommended by the British Thoracic Society. 88% completed treatment. Eighty four per cent of those with disease had been notified. Treatment of those in the infection or contact groups were treated more aggressively than the British Thoracic Society guidelines, with six months of treatment with isoniazid and rifampicin. Directly observed therapy was used in 17 children (24%). Only 53% of Indo-asian children had received BCG immunisation. CONCLUSIONS: Most children were managed according to the British Thoracic Society guidelines. A management system, with a computerised database, has facilitated both patient management and audit, and ensured the delivery of quality care.

Gross efficiency responses to exercise conditioning in adult males of various ages.

This study investigated gross efficiency changes in a group of 60 adult males (mean age 39.2 +/- 1.2 years) resulting from endurance training and age-related responses to such training in sub-groups (each n = 20) of younger (30.7 +/- 0.7 years), intermediate (38.3 +/- 0.5 years) and older (48.6 +/- 1.1 years) subjects. Gross efficiency (%) was calculated from work output, oxygen consumption and RER energy equivalents following 10 min standard cycle ergometry exercise at 100 W and 50 rev min-1. Measurements were made at pre-, mid- and post-8 months of training, which involved progressive walking/jogging activities designed to enhance endurance capacity. In the total group, VO2 decreased pre- to post-training from 2.15 +/- 0.02 to 1.93 +/- 0.01 1 min-1 (P less than 0.01). In the sub-groups, both the younger and older subjects showed a significantly reduced VO2, from 2.17 +/- 0.01 to 1.98 +/- 0.04 1 min-1 and 2.05 +/- 0.08 to 1.86 +/- 0.03 1 min-1 respectively (P less than 0.05), but no significant changes were noted at mid-training. In the intermediate age subjects, while there were trends towards a reduced VO2, none was significant. The ANOVA revealed increased mean gross efficiency in the total group from pre- (14.3 +/- 0.1%) to post- (15.5 +/- 0.2%) (P less than 0.05) but not at mid-training (14.8 +/- 0.2%). While similar trends were observed in the sub-groups, gross efficiency increases were not significant, although changes in gross efficiency were reflected in VO2. The findings suggest that during standardized exercise, oxygen cost may be reduced and gross efficiency increased in adult males following endurance training and that such changes may take place over a variety of age ranges.

Effect of endurance training on gross energy expenditure during exercise.

We compared the effect of endurance exercise training on gross energy expenditure (GEE) during steady-state exercise in 20 younger men (31.2 +/- 0.6 years) and 20 middle-aged men (49.2 +/- 1.1 years). The subjects trained for eight months. The training program consisted of three 45-min walking and jogging exercise sessions per week at an intensity of approximately 60-85% of the heart rate at peak VO2. We administered bicycle ergometer tests at 0, 4, and 8 months into training. Participants exercised at a power output of 100 W for 10 min using a pedaling frequency of 50 rpm. We determined GEE (kcal/min) by measuring the oxygen consumption and respiratory exchange ratio. We found a significant reduction (p less than 0.05) in GEE (0.7-1.3 kcal/min) following 4 months of endurance training in both age groups, with a further reduction (p less than 0.05) noted in only the middle-aged group at month 8. We found no difference (p greater than 0.05) in GEE between the younger and middle-aged men. We conclude that chronic exercise may modify GEE during a submaximal exercise bout and that this adaptation is similar in magnitude in younger and middle-aged men.

A longitudinal study of energy expenditure in males during steady-state exercise.

Our purpose was to investigate longitudinal changes in gross energy expenditure (GEE) of 20 middle-aged and older men during submaximal exercise in 1969 and in 1985. GEE (kcal/min) was estimated using the caloric equivalent for each liter of oxygen consumed at the measured respiratory exchange ratio during submaximal exercise. The men performed a 10-min submaximal cycle ergometer exercise test at a power output (PO) of 100 W. Pedalling frequency was 50 rpm. Results showed a significant 5.9% decrease in GEE (p less than .01) from 8.5 +/- 0.8 (M +/- SD) kcal/min in 1969 to 8.0 +/- 0.4 (M +/- SD) Kcal/min in 1985. In addition, the effects of chronological age and leisure time physical activity on GEE were assessed and found to be nonsignificant, although a significant decrease in GEE over time (p less than .02) was observed in both groups. The present results support a decrease in GEE in middle-aged and older men over the 16-year time period. Furthermore, this decrease in GEE persisted regardless of chronological age or leisure time physical activity status.

Correlates of blood pressure in elementary schoolchildren.

This cross-sectional study determined which anthropometric, dietary, and physical fitness variables were best predictors of blood pressure (BP) in 323 white elementary schoolchildren. Height, weight, triceps, and subscapular skinfold thickness were measured, followed by two resting BP measurements. Cardiorespiratory fitness was assessed by time in a one mile run. A food frequency questionnaire measured habitual dietary intake. Correlational analysis revealed height, weight, body mass index (wt/ht2), and skinfold thicknesses were anthropometric variables associated significantly with both systolic and diastolic blood pressure. Physical fitness was not correlated with BP and, among dietary variables, only estimated daily caloric intake, dietary cholesterol, and nondiscretionary sodium were related to blood pressure. A multiple regression analysis selected weight, body mass index (BMI), and total caloric intake as factors explaining the greatest amount of BP variability. For some individuals, hypertension may originate in childhood, thus, these results could have implications for primary prevention of high blood pressure.

Influence of short-term cycling on salivary cortisol levels.

The purpose of this study was to examine the response of salivary cortisol to acute exercise, and to directly compare serum and salivary cortisol responses to sub-maximal exercise. Eight males volunteered to participate in the study. On three separate days following the assessment of maximum oxygen uptake (VO2max), the subjects exercised on a bicycle ergometer at 75% of their VO2max for 30 min. On a fourth day, the subjects rested quietly, and this served as a control condition. On each of these days, five serial samples of either blood, saliva, or both blood and saliva were obtained at 15-min intervals before, during, and after exercise. Submaximal exercise elicited a significant (P less than 0.05) increase in both serum and salivary cortisol above resting control levels immediately and 15 min following exercise under all exercise conditions. In addition, significant correlations (all P less than 0.01) were observed between serum and salivary cortisol at each of the five sampling periods. The correlations were as follows: r = 0.89 at -15 min; r = 0.60 at 0 min; r = 0.72 at 15 min; r = 0.90 at 30 min; and r = 0.93 after 15 min of recovery. Saliva was also obtained immediately before and 5 min following the assessment of VO2max, and there was a significant (P less than 0.05) increase in post-VO2max test (1.07 +/- 0.12 micrograms X dl-1) compared to pre-test (0.71 +/- 0.06 micrograms X dl-1) salivary cortisol levels. The results of this experiment indicate that salivary cortisol is a potentially valid measure of serum cortisol response to short-term cycling.

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.