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Biomedical subjects

J Loke

Publications and source records attributed to J Loke.

53 records · Page 3Linked to original sources
PubMed1981

Lung function after marathon running at warm and cold ambient temperatures.

using maximal expiratory flow-volume curves we studied the effects of endurance exercise on lung function in 46 and 41 runners before and after completion of a marathon race (42.2 km) at different ambient temperatures. There was a significant decrease (-3.9%; -5.9%) in the post-race forced vital capacity in runners at each marathon. The mean values for forced expiratory volume in one second did not change. Post-race peak flow at 50% of forced vital capacity were significantly decreased in runners participating in subfreezing conditions (-2 degrees C to -4 degrees C), but were unchanged when the ambient temperature was above freezing. These data demonstrated that healthy persons may develop bronchoconstriction during endurance exercise in subfreezing temperatures. The decrement in forced vital capacity noted in marathon runners competing at above freezing temperatures may be related to fuel metabolism and running performance.

Adolescent↗
PubMed1981

Bronchofiberscopy with curette biopsy and bronchography in the evaluation of peripheral lung lesions.

Flexible bronchofiberscopy using a double-hinged curette biopsy and under fluoroscopic guidance was performed on 46 patients with peripheral lung carcinomas smaller than 2 cm. Prior mapping of the location of the lung lesion was achieved with selective peripheral bronchography. With these diagnostic tools, a positive cytologic diagnosis for lung carcinomas was made in 45 of 46 patients, a yield of 97.8 percent. Complications associated with the curette biopsy included minor bleeding in three cases and pneumothorax requiring a chest tube in one case.

Adult↗
PubMed1981

Effect of physical training on exercise performance of children following surgical repair of congenital heart disease.

The effect of physical training on the exercise performance of 26 patients following surgical repair of tetralogy of Fallot (16 patients) and ventricular septal defect (ten patients) was evaluated. Base line exercise testing was performed on a bicycle ergometer using the technique of Godfrey. Patients were placed on a six-week alternate day submaximal interval home exercise program of varying duration and intensity. Work loads at 50%, 60%, and 70% maximum oxygen consumption were selected to maintain heart rates between 130 and 160 beats per minute. Subjects completed an average of 18 of the possible 21 training sessions (range 11 to 21). A 25% improvement (p less than .001) was noted in maximum work capacity (747 to 935 km). Sixty-five percent of the patients performed at less than expected maximum work capacity prior to training, but only 31% performed at less than expected maximum work capacity after training. Repeat testing at work loads of one-third, one-half, and two-thirds the original maximum work capacity revealed improved aerobic efficiency as manifested by significantly decreased oxygen consumption and heart rate at each level of work. No significant difference was noted in maximum oxygen consumption. It is concluded that physical training can improve the exercise performance of patients after surgical repair, permitting the individuals to function at levels of activity at, or closely approaching, normal.

Adolescent↗
PubMed1981

Exercise performance in marathon runners with airway obstruction.

While evaluating lung function prior to four long-distance races (20-100 km), we found that nine of 127 marathon runners (7.1%) had airway obstruction (mean FEV1/FVC, 63.3%). Since obstruction to air flow may limit exercise performance, we compared selected cardiorespiratory parameters during exercise on a cycle ergometer in runners with airway obstruction (RAO), nine non-athletic control subjects (CON), and nine marathon runners with normal lung function (RNL). As the chemical drive to breath affects exercise hyperpnea, the ventilatory responses to hypercapnia and hypoxia were measured. All RAO were males with a mean age of 35.6 yr (range of 20-44 yr). Eight of nine RAO had a significant increase in flow rates after inhalation of isoproterenol. In the RAO and CON groups exercise ventilation was similar when oxygen consumption (VO2) was less than 2.0 l/min; as VO2 exceeded this level, significantly greater ventilation was required by the RAO. Carbon dioxide production was highest in RAO, intermediate in CON, and lowest in RNL. There was no significant difference in the mean ventilatory responses among CON, RAO, and RNL. Despite pulmonary dysfunction, the RAO achieved moderate-to-high levels of exercise performance.

Adult↗
PubMed1980

Acute and chronic effects of fire fighting on pulmonary function.

The acute and chronic effects of fire fighting on pulmonary function were studied in 54 fire fighters from Connecticut, 32 smokers and 22 nonsmokers. Baseline studies of maximum expiratory flow-volume curves while breathing air and a mixture of 80 percent helium and 20 percent oxygen revealed obstruction of the small airways in 35 percent (nine) of 26 smokers and 13 percent (two) of 15 nonsmokers. Cigarette smoking appears to be a major contributor to obstruction of the airways in fire fighters. In the nonsmoking group, disease of the small airways was present only in fire fighters with at least 25 years of fire fighting, and none of them had respiratory complaints. In seven fire fighters retested immediately following mild exposure to a fire in a building, no significant changes in pulmonary function were noted. One fire fighter trapped in a fire in a basement had a high level of carboxyhemoglobin (42 percent) and developed a severe obstructive ventilatory defect which persists 2 1/2 years after the fire. The significance of disease of the small airways in fire fighters with chronic exposure remains to be elucidated with long-term studies; however, acute significant exposure may be associated with irreversible pulmonary injury in fire fighters.

Adult↗
PubMed1980

Right and left ventricular exercise performance in chronic obstructive pulmonary disease: radionuclide assessment.

Right and left ventricular pump performance was assessed at rest and during upright bicycle exercise in 30 patients with chronic obstructive pulmonary disease and in 25 normal control subjects. Right ventricular and left ventricular ejection fractions were ascertained noninvasively using first-pass quantitative radionuclide angiocardiography. The normal ventricular response to exercise was at least a 5% absolute increase in the ejection fraction of either ventricle. In patients the predominant cardiac abnormality involved performance of the right ventricle. Right ventricular ejection fraction was abnormal at rest in eight patients. Twenty-three patients demonstrated an abnormal right ventricular response to submaximal exercise. Airway obstruction and arterial hypoxemia were significantly more severe in patients with abnormal right ventricular exercise reserve than in those with normal reserve. Abnormal left ventricular performance was infrequent either at rest (four patients) or during exercise (six patients). Thus, this radionuclide technique allows noninvasive assessment of biventricular exercise reserve in chronic obstructive pulmonary disease.

Adult↗
PubMed1978

Assessment of cardiac performance with quantitative radionuclide angiocardiography: right ventricular ejection fraction with reference to findings in chronic obstructive pulmonary disease.

A reproducible noninvasive technique for measuring righ ventricular ejection fraction was developed using first pass quantitative radionuclide angiocardiography. Studies were obtained in the anterior position with a computerized multicrystal scintillation camera with high count rate capabilities. Right ventricular ejection fraction was calculated on a beat to beat basis from the high frequency components of the background-corrected right ventricular time-activity curve. In 50 normal adults, right ventricular ejection fraction averaged 55 percent (range of 45 to 65 percent). This radionuclide measure of right ventricular function was reproducible, with minimal inter- and intraobserver variability, and was sensitive to changes in inotropic state induced with isoproterenol. In 36 patients with chronic obstructive pulmonary disease, right ventricular ejection fraction ranged from 19 to 71 percent. All 10 patients with corpulmonale, as well as 9 additional patients, had an abnormal right ventricular ejection fraction. Arterial oxygen tension and forced expiratory volume were depressed significantly more in patients with abnormal right ventricular ejection fraction than in subjects with normal right ventricular function. There was no relation between abnormalities in right and left ventricular ejection fraction.

Adult↗
PubMed1977

Radiographic manifestations of acute smoke inhalation.

Acute smoke inhalation may lead to serious pulmonary injury and contribute significantly to mortality of fire victims. The chest radiographic findings in 21 patients with acute smoke inhalation are analyzed, and possible pathophysiologic mechanisms responsible for the radiographic abnormalities noted are discussed. Patients with surface injury burns were intentionally eliminated from this study. Our findings indicate that the standard chest radiograph is an insensitive means of determining pulmonary injury by smoke inhalation. The importance of blood carboxyhemoglobin levels and arterial blood gas determinations in the clinical evaluation of patients with acute smoke inhalation is stressed.

Acute Disease↗
PubMedDate not supplied

The pulmonary effects of free-base cocaine: a review.

The number of people smoking free-base cocaine, or "crack," has increased dramatically in recent years. Concomitantly, the literature describing complications of such use has grown as well. Adverse pulmonary effects are being increasingly noted, such as respiratory symptoms, pulmonary hemorrhage, pulmonary edema, asthma, and pulmonary barotrauma. These and other pulmonary effects are reviewed.

Crack Cocaine↗
PubMedDate not supplied

Systemic and discoid lupus erythematosus: analysis of pulmonary function.

To determine the prevalence of pulmonary dysfunction in lupus erythematosus, 24 patients with systemic lupus erythematosus (SLE) and 5 patients with discoid lupus erythematosus (DLE) were studied. Diffusing capacity for carbon monoxide was abnormal in 17 (71 percent) SLE patients. A restrictive ventilatory defect was present in 6 (25 percent) and arterial hypoxemia in 4 of 23 (17 percent). The mean ratio of forced expiratory volume in one second to forced vital capacity (FVC) was 83 percent. To test for the presence of small airways disease, maximum expiratory flow rate at 50 percent of FVC was measured on air and on an 80 percent helium-20 percent oxygen mixture. Ten patients (5 smokers and 5 nonsmokers) with SLE were nonresponders to helium suggesting small airways disease. Pulmonary dysfunction was present in 90 percent (9/10) of SLE patients with a previous history of pleuritis and/or pneumonitis, and in 71 percent (10/14) without respiratory symptoms or history of lung disease and with a normal chest radiograph. Pulmonary function tests were normal in DLE patients except for an abnormal response to helium and/or mild arterial hypoxemia in two patients, all of whom were smokers. These data indicate that there is a high prevalence of pulmonary function abnormalities in SLE including patients without clinically evident pleuropulmonary disease.

Female↗
PubMedDate not supplied

Pulmonary dysfunction in ultramarathon runners.

To assess the effects of extreme exercise on lung function we measured maximal expiratory flow volume (MEFV) curves in fifteen runners (mean age, 35.3 years; range, 26-46) before and after an 80.6 to 100 km (50-62.2 mile) road race. Mean running time for 80.6 km was 7 hr, 42 min. Post-race testing showed significant decreases of 12.4 percent in forced vital capacity (FVC), 9.5 percent in forced expiratory volume in one second (FEV1) 13.7 percent in peak expiratory flow (PF), and 28.4 percent in flow at 50 percent of FVC (MEF50). By 2.5 hours after the race lung function had improved. The reduction in flow rates after ultramarathon running may be due to airway obstruction. In contrast, the decrease in FVC with gradual recovery of lung function after rest and nourishment suggests the development of respiratory muscle fatigue.

Adult↗