Reduced Exercise Capacity in Non-Cystic Fibrosis Bronchiectasis

Objective : Bronchiectasis not due to cystic fibrosis is usually a consequence of severe bacterial or tuberculous infection of the lungs, which is commonly seen in children in developing countries. Our aim was to study its functional sequelae and affect on work capacity in children. Methods : Seventeen children (7-17 years of age) with clinical and radiological evidence of bronchiectasis of one or both lungs were studied at the Cardiopulmonaly Unit of the Tuberculosis Research Centre. Pulmonary function tests including spirometry and lung volume measurements were performed. Incremental exercise stress test was done on a treadmill, and ventilatory and cardiac parameters we monitored. Control values were taken from a previous study. Results : Children with bronchiectasis had lower forced vital capacity (FVC) (1.1 + 0.4 L versus 1.5 + 0.4 L, p=0.003) and FEV1 (0.95 ± 0.2 L versus 1.4 ± 0.3 L, p<0.002) compared to age- and sex-matched healthy controls. The patient group had significantly higher residual lung volumes (0.7 ± 0.3 L versus 0.4 + 0.1 L, p<0.02). At maximal exercise, they had lower aerobic capacity (28 ± 6 ml/min/kg versus 38 5 ml/min/kg, p<0.0001) and maximal ventilation (24 ± 8 L/min versus 39 ± 10 L/min, p<0.001). At maximal exercise, while none of the controls desaturated, oxygen saturation fell below 88% in eight of 17 patients. conclusion ;The findings show that children and adolescents with non-cystic fibrosis bronchiectasis have abnormal pulmonary function and reduced exercise capacity. This is likely to interfere with their lie as well as future work capacity. Efforts should be made to minimize lung damage in childhood by ensuring early diagnosis and instituting appropriate treatment of respiratory infections

Aerobic capacity and cardio-pulmonary responses to exercise in healthy South Indian children

Objective: To examine the cardiorespiratory response to exercise in healthy South Indian school children. Design: Prospective study. Setting: Cardiopulmo nary Medicine Unit, Tuberculosi s Research Center, Ma dras. Subjects: Data was obtained on 47 girls an d 48 boys in the age group 7 to 14 years. Intervention: The children performed a graded maximal exercise stress test on a compute rized treadmill system. Results: Maximum oxygen consumption (VO2max) increased significa ntly at 11 years of a ge in both sexes b ut while boys sho wed a progressive increase beyond 11 years, girls did not. When corrected for weight , only boys at 14 years had a significant increase in VO2max/kg. Boys had higher values of VO2max/kg than girls at all ages. Minute venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen prediction equations based on height were used. However, when regression equations based on weight were used, the predicted values for North American and South Indian boys were similar, though values for the Indian girls were still low. Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different pop ulations, rather than ethnic differences alone. significa ntly at 11 years of a ge in both sexes b ut while boys sho wed a progressive increase beyond 11 years, girls did not. When corrected for weight , only boys at 14 years had a significant increase in VO2max/kg. Boys had higher values of VO2max/kg than girls at all ages. Minute venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen prediction equations based on height were used. However, when regression equations based on weight were used, the predicted values for North American and South Indian boys were similar, though values for the Indian girls were still low. Conclusions: Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different populations, rather than ethnic differences alone

Oxygen consumption at rest and after moderate aerobic exercise in sportsmen

The oxygen consumption at rest and after moderate aerobic exercise on a treadmill was estimated in 20 sportsmen of Loyola College, Madra s T.he mean oxygen consumption index at rest was 118 ml/min/m2 end there was a three-fold increase in oxygen consumption after walking at 5 k.m. per hour for five minutes on the treadmill.T he rise in pulse rate and the rise in systolic blood pressure after the exercise did not have any significant correlation with the excess oxygen consumption. However. the product of the rise in pulse rate end the rise in systolic blood pressure (double product) showed a significant correlation with the excess oxygen consum e d . The excess minute ventilation showed a positive correlation with the excess oxygen consumed, whereas the PO2 difference between the inspired and expired air showed a negative correlation. It is suggested that after moderate aerobic exercise in sportsmen, the initial responses are more on the respiratory system rather on the cardiovascular system

Transfer co-efficient for carbon monoxide in sportsmen

The transfer factor (TLCO) and the transfer coefficient (KCO) for carbon monoxide were measured by the single-breath method in eleven non-smoking college sportsmen. The mean transfer factor for whole lung in the college sportsmen was within normal limits when compared to predicted values of European descent; however, the transfer coefficient was high and is thought to be due to a rise in pulmonary capillary blood volume. It is postulated that continuous and prolonged training of sportsmen causes recruitment of pulmonary capillaries and this causes increased capillary blood volume even at rest

High intensity exercise training programme following cardiac transplant

A 26-year-old male patient who presented with symptoms of end stage cardiac failure as a result of dilated cardiomyopathy, had an orthotopic cardiac transplantation. A comprehensive cardiac rehabilitation programme was provided to him and he was introduced to a sport (tennis). The exercise training programme progressed from low intensity training to high intensity programme over a period of 15 months. A cardio-pulmonary exercise test done 22 months after surgery suggested that he was able to achieve the aerobic capacity comparable to that of a normal South Indian subject. He participated successfully in the World Transplant Games in Sydney and returned safely. This suggests that after a proper cardiac rehabilitation programme, patients undergoing heart transplantation can achieve normal physiological responses to lead a normal active lif

Punchthrough-Diode-Based Bipolar RRAM Selector by Si Epitaxy

We propose an epitaxial punchthrough diode for bipolar resistance RAM (RRAM) selector application. Epitaxial Si: C process is used to deposit n(+)/p/n(+) layers which are fabricated into 300-nm-diameter vertical punchthrough diodes. High on-current density of > 1 MA/cm(2) and high on/off current ratio of > 250 and > 4700 (at opposite polarities) are observed. A switching speed of < 10 ns is measured. On-voltage designability is demonstrated by tuning the p-region doping and length. The comparison of experimental IV with Sentaurus TCAD-simulated IV characteristics confirms the punchthrough mechanism. Comparison with other bipolar RRAM selector technologies highlights the overall advantages of punchthrough-based selector