No abstract available.
Asthma* ; Humans ; Physicians, Primary Care* ; Primary Health Care*

BACKGROUND: There are many suggested methods for the indirect determination of anaerobic threshold(AT) using the changes of ventilatory parameters in respones to ventilatory load accompanying the increase of blood lactic acid level during exercise and the threshold derived from them is called ventilatory threshold( VT). They include ventilatory equivalent method(VEM), End-tidal PO2 method(PETO2), V-slope method(VSM), and respiratory quotient method(RQ). But in the patients with chronic airway ohstruction(CAO), the AT determined by ventilatory methods may not reflect true AT because the patients with GAO show inadequate ventilatory response to the increase of blood lactic acid level during excercise. METHODS: For the investigation of detection rate and reliability of above four VT determination methods in the patients with GAO, we performed the symptom-limited and maximal incremental exercise test in 17 patients with GAO and 12 normal controls. The incremental workload was 10 W/min in GAO group and 25 W/min in control group. The reliability of VT in each group was investigated by the calculation of Spearman correlation coefficient. RESULTS: The detection rates of VT were 100% by RQ, 91.7% by both VEM and POETO2, and 83.3% by VSM in normal control group, while 94.1% by RQ, 64.7% by VEM and PETO2, and 83.3% by VSM in GAO group. Good correlations were noted among VEM, PETO2, and VSM except RQ in normal control group. But there was no significant correlation except between VEM and PETO2 in GAO group. CONCLUSIONS: RQ is very sensitive but crude and VEM is near similar to PETO2. The clinical usefulness of VT determined by ventilatory method might be limited in patients with severe GAO.
Airway Obstruction* ; Exercise Test ; Humans ; Lactic Acid

BACKGROUND: Normal humans meet the increased ventilatory need during exercise initially by the increase of tidal volume (TV) and later by the increase of respiratory frequency (Rf). And the inspiratory duty cycle (Ti/Ttot) is also increased more than 50% for the compensation of the decrease of respiratory cycle provoked by the increase of respiratory frequency. The patients with chronic airflow obstruction show rapid and shallow breathing pattern during exorcise because of the degreased ventilatory capacity and the increased dead space ventilation. However, the studies about the change of inspiratory duty cycle are only a few and there is no literature about the relationship between the change of inspiratory duty cycle and the degree of airflow obstruction. METHODS: The subjects were the twelve patients with chronic airflow obstruction (CAO) and ten normal people. The incremental exercise test was done. The increase of work load was 10 Win CAO group and 25 Win normal control group. The analysis of the results was done by the comparison of the parameters such as minute ventilation (VE), TV, Rf, physiologic dead space (Vd/vt), and inspiratory duty cycle between the two groups. Each parameters were compared after transformation into % control duration base that means dividing the total exercise time into five fractons and % control duration data were obtained at rest, 20%, 40%, 60%, 80%, and max. Statistical analysis was done by repeated measure ANOVA using SAS program. RESULTS: The changes of VE and TV were significantly different between two groups while the change of Rf was not significant. The decrease of Vd/vt was significantly low in CAO group. Ti/Ttot was markedly increased from 38.4+3.0% at rest to 48.6+4.5% at max in normal control group while Ti/Ttot showed little change from 40.5+2.2% at rest to 42.6+3.5% at max. And the change of inspiratory duty cycle showed highly good correlation with the degree of airflow obstruction (FEVl%). (r=0.8151, p<0.05) CONCLUSIONS: The increase of Ti/Ttot during exercise observed in normal humans is absent in the patients with CAO and the change of Ti/TtDt is well correlated with the degree of airflow obstruction.
Compensation and Redress ; Exercise Test* ; Humans ; Pulmonary Disease, Chronic Obstructive* ; Respiration* ; Tidal Volume ; Ventilation

No abstract available.
Cough* ; Primary Health Care*

No abstract available.
Cough* ; Humans ; Hydrogen-Ion Concentration*

BACKGROUND AND OBJECTIVE: The knowledge about the effects of the nebulized B2-agonist on serum potassium is limited. We aimed to assess the possible hypokalemia following nebulization of salbutamol. METHOD: Seven patients(mean age 60 +- 7.1years) with acute exacerbated asthma were treated with salbutamol nebulization(5mg nebulization at 1 hour interval, 3 times) without concomitant use of steroid or other bronchodilator such as theophylline. RESULTS: There was a significant increase in FEV1, from 46.41+-25.91% at baseline to 62.86+-22.38% at 3 hours after treatment. Serum potassium concentration was significantly decreased, from 3.93+-0.58mEq/L at baseline to 3.41+-0.62mEq/L and 3.46+-0.53mEq/L at 1 hour and 3 hours after third nebulization, repectively. There was a significant prolongation of the QTc interval in EKG from 454.36+-27.07msec at baseline to 479.41+-35.64msec and 505.09+-58. 69msec at 1 hour and 3 hours after third nebulization, respectively. Serum salbutamol concentration was 4.18+-3.39ng/ml at baseline, and increased to 7.69+-6.94ng/ml and 9.84+10.34ng/ ml at 1 hour and 3 hours after treatment, respectively. Magnitude of the hypokalemia and the degree of prolongation of the electrocardiographic QTc interval were significantly correlated with the level of serum salbutamol concenturation. CONCLUSION: The results suggest that cardiac complication could develop due to hypokalemia during repeated salbutamol nebulization. Caution should be done in monitoring of serum potassium concentration when using nebulized salbutamol repeatedly for the treatment of acute exacerbated bronchial asthma.
Albuterol* ; Asthma ; Electrocardiography ; Hypokalemia ; Potassium* ; Theophylline

BACKGROUND: IL-8 is a potent chemotactic cytokine that plays an important role in the host defense mechanism against M. tuberculosis by recruiting inflammatory cells to the site of the infection. Lung epithelial cells, as well as alveolar macrophages are known to preduce IL-8 in response to M. tuberculosis. IL-8 gene expression is mainly regulated on the level of transcription by NF-κB. This study investigated whether or not A549 cells produce IL-8 in NF-κB dependent mechanism in response to macrophages phagocytosing M. tubersulosis. METHODS: Peripheral blood monocytes that were obtained from healthy donors were cultured for 24 h with M. tuberculosis and a conditioned medium(CoMTB) was obtained. As a negative control, the conditioned medium without M. tuberculosis (CoMCont) was used. A549 cells were stimulated with M. tuberculosis, CoMCont and CoMTB and the IL-8 concentration in the culture media was measured by ELISA. The CoMTB induced IL-8 mRNA expression in the A549 cells was evaluated using RT-PCR, and CoMTB induced IκBα degradation was measured using western blot analysis. CoMTB induced nuclear translocation and DNA binding of NF-κB was also examined using an electrophoretic mobility shift assay(EMSA), and the CoMTB induced NF-κB dependent IL-8 transcriptional activity was measured using a luciferase reporter gene assay. RESULTS: CoMTB induced IL-8 production by A549 cells(46.8±4.8 ng/ml) was higher than with direct stimulation with M. tuberculosis (6.8±2.9 ng/ml). CoMTB induced IL-8 mRNA expression increased after 2 h of stimulation and was sustained for 24 h. IκBα was degraded after 10 min of CoMTB stimulation and reappeared by 60 min. CoMTB stimulated the nuclear translocation and DNA binding of NF-κB. The CoMTB induced NF-κB dependent IL-8 transcriptional activity(13.6±4.3 times control) was higher than either CoMCont(2.0±0.6 times control) or M. tuberculosis (1.4±0.6 times control). CONCLUSION: A conditioned medium of peripheral blood monocytes phagocytosing M. tuberculosis stimulates NF-κB dependent IL-8 production by the lung epithelial cells.
Blotting, Western ; Culture Media ; Culture Media, Conditioned ; DNA ; Enzyme-Linked Immunosorbent Assay ; Epithelial Cells* ; Gene Expression ; Genes, Reporter ; Humans ; Interleukin-8* ; Luciferases ; Lung* ; Macrophages ; Macrophages, Alveolar ; Monocytes* ; Mycobacterium tuberculosis* ; Mycobacterium* ; RNA, Messenger ; Tissue Donors ; Tuberculosis

No abstract available.
Asthma

No abstract available.
Aged* ; Humans