PubMed Health⌕ Search

Biomedical subjects

C Lan

Publications and source records attributed to C Lan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Metabolic and functional effects of low-potassium cardioplegic solutions for long-term heart preservation.

Cardioplegic solutions used to arrest the heart during open heart surgery and cardiac transplantation are based on potassium as a cardioplegic agent in a concentration range of 15-35 mM. However, high to moderate K+ concentrations increase Ca2+ influx and impair endothelial function. We have therefore evaluated the possible advantage of a lower potassium concentration in a new cardioplegic solution (named CRMBM solution) designed for long-term heart preservation. Nine isolated perfused rat hearts were submitted to 8 h of hypothermic ischemia after cardioplegic arrest, followed by 60 min of reflow at 37 degrees C. Two cardioplegic solutions were compared: (1) the CRMBM solution with 10 mM potassium (K-10 group), and (2) the CRMBM solution with 4 mM potassium (K-4 group). The quality of heart preservation was assessed by a metabolic study using P-31 magnetic resonance spectroscopy (energy metabolism and intracellular pH) combined to a functional evaluation and a measure of cellular integrity (biochemical assays in effluents and tissues). Decreasing the potassium concentration to 4 mM improved heart preservation, as shown by a higher functional post-ischemic recovery represented by the rate pressure product and a better preservation of cellular integrity. The evolutions of intracellular pH and high energy phosphate levels during ischemia and reflow were similar in both groups.

Animals↗
PubMed1999

Optimized cardiac graft preservation: a comparative experimental study using P-31 magnetic resonance spectroscopy and biochemical analyses.

BACKGROUND: The University of Wisconsin (UW), St. Thomas (ST) and Broussais (B) solutions were compared to the CRMBM solution, that we developed for long term heart preservation. METHODS: Isolated isovolumic rat hearts were arrested with each cardioplegic solution (n = 5) to 8 hearts in each group), submitted to 12 hours of cold storage (4 degrees C) in the same solution and then reperfused for 60 minutes at 37 degrees C. Function was measured during control and reflow. High energy phosphates and intracellular pH were monitored by P-31 magnetic resonance spectroscopy. Analyses were performed by biochemical assays and HPLC in coronary effluents (CK, Pi, lactate, purines) and in freeze-clamped hearts (amino acids, nucleotides, CK, LDH) at the end of reperfusion. RESULTS: Functional recovery was significantly improved with the new cardioplegic solution (50+/-12% recovery for the rate pressure product at the end of reflow vs 8+/-3% with UW, 0% with B and with ST). This result was correlated with the best metabolic and cellular protection as assessed in particular by higher PCr levels during reflow (30+/-3% vs 10+/-3% with UW, 8+/-4% with B, and 7+/-1% with ST) as well as reduced creatine kinase leakage during reflow (110+/-15 IU/60 minute vs 270 +/- 57 IU/60 minute with UW, 323+/-36 IU/60 minute with Broussais solution and 237+/-18 IU/60 minute with ST). CONCLUSION: This new solution is more effective in prolonged myocardial protection than the three most widely used solutions.

Acid-Base Equilibrium↗
PubMed1999

The effect of Tai Chi on cardiorespiratory function in patients with coronary artery bypass surgery.

PURPOSE: This study prospectively evaluated the training effect of a 1-yr Tai Chi Chuan (TCC) program for low-risk patients with coronary artery bypass surgery (CABS) after a postoperative outpatient (phase II) cardiac rehabilitation program. METHODS: Twenty patients with mean age of 56.5+/-7.4 yr completed this study. The TCC group included nine men who practiced classical Yang TCC with an exercise intensity of 48-57% heart rate range (HRR). The control group included 11 men whom were recommended to do a home-based self-adjusted exercise program with similar intensity of phase II cardiac rehabilitation. Graded exercise tests were performed before and after 1 yr of training for all subjects. RESULTS: Mean attendance of the TCC group was 3.8+/-1.5 times weekly in contrast to 1.7+/-1.1 times for the control group. During the follow-up examination, the TCC group increased 10.3% in VO2peak (from 26.2+/-4.4 to 28.9+/-5.0 mL x kg(-1) min(-1), P<0.01) and increased 11.9% in peak work rate (from 135+/-26 W to 151+/-28 W, P<0.01). However, the control group showed slight decrease in VO2peak from 26.0+/-3.9 to 25.6+/-4.6 mL x kg(-1) x min(-1) and in peak work rate from 131+/-23 W to 128+/-32 W. At the ventilatory threshold, the TCC group also showed significant increase in VO2 and work rate (P<0.05). The control group did not significantly change in these variables. CONCLUSIONS: The study demonstrated that a 1-yr TCC program for low-risk patients with CABS could favorably enhance cardiorespiratory function.

Analysis of Variance↗
PubMed1999

Dietary fish oil promotes positive inotropy of ouabain in the rat heart.

We tested the hypothesis that a fish oil (FO) diet promotes positive inotropy of ouabain without increased toxicity. For 2 mo, two groups of adult male rats were fed 1) a regular food diet supplemented with dietary long-chain polyunsaturated fatty acid from FO or 2) a regular food diet (control). The responsiveness to ouabain was evaluated for the two groups in Langendorff-perfused hearts, by (31)P nuclear magnetic resonance spectroscopy, and on purified membrane-bound Na-K-ATPase. The maximum positive inotropy achieved with ouabain was nearly two times higher in the FO than in the control group and was not associated with significant changes in energetics. Alteration of function and energetic metabolism and inhibition of Na-K-ATPase in response to 3 x 10(-4) M ouabain were delayed in the FO group. This study demonstrates that dietary FO, by a cardiac membrane incorporation of n-3 polyunsaturated fatty acid, promotes positive inotropy of ouabain without toxicity and changes in cardiac metabolism.

Animals↗
PubMed1999

Cardiorespiratory response of heart transplantation recipients to exercise in the early postoperative period.

In this study, we evaluated the cardiorespiratory function of orthotopic heart transplantation (OHT) recipients during exercise. Seventeen male OHT recipients, ranging in age from 22 to 60 years, participated in this study 47 +/- 21 days after surgery. The control group consisted of 17 sedentary healthy men. Breath-by-breath measurement of cardiorespiratory function was obtained during the incremental exercise of leg cycling. At peak exercise, the oxygen (O2) uptake (16.5 +/- 3.3 vs 33.9 +/- 8.2 mL.kg-1.min-1), work rate (82 +/- 19 vs 169 +/- 42 watts), heart rate (HR), O2 pulse, and blood lactate level of the OHT recipients were significantly lower than the respective values of the control group. At the ventilatory threshold, the OHT group also showed a significantly lower O2 uptake (10.7 +/- 1.6 vs 18.3 +/- 5.1 mL.kg-1.min-1), work rate (39 +/- 12 vs 89 +/- 33 watts), HR, O2 pulse, ventilatory equivalent for O2, and ventilatory equivalent for carbon dioxide. The OHT recipients showed a high resting HR (97 +/- 7 beats/min) and a low peak HR (123 +/- 14 beats/min) during exercise, and their HR continued to increase for 1 to 3 minutes after cessation of exercise. Our data revealed a low level of cardiorespiratory endurance in OHT recipients during the early postoperative stage. A multidisciplinary cardiac rehabilitation program should be considered to enhance physical functional capacity and quality of life, and promote return to work.

Adult↗
PubMed1999

[A pilot study on malaria control by using a new strategy of combining strengthening infection source treatment and health education in mountainous areas of Hainan province].

AIM: To explore a new malaria control strategy that fits current epiodemiological condition and coincides with modern medicine model and the principle of cost-benefit. METHODS: The new strategy highlights the risk villages and risk population as the focal point and integrates health education with behavioral intervention. The main anti-malaria measures consists of carrying out health education in risk villages, giving mass drug administrations in risk population staying overnight in the mountain, following up malaria cases for implementing radical cure, but without using traditional residual spraying or impregnating bednets with insecticides. RESULTS: After having adopted the new strategy and taken the control measures, the people's knowledge about malaria increased to a higher level and the indices of malaria reduced to a lower level. The rate of bednet-using in the population was increased from 26.8% to 72.6%. The annual parasite incidence (API) of malaria was declined from 3.5% in 1994 to 1.1% in 1996 and 0.8% in 1997, and the API of falciparum malaria was declined from 1.0% to 0.3% and 0.3% respectively in the townships at the same time. The parasite rate(PR) of malaria was declined from 7.2% in May, 1995 to 2.1% in November, 1996 and 1.2% in October, 1997 and the PR of falciparum malaria was declined from 1.2% in May, 1995 to 0.1% in October, 1997. The proportion of villages without malaria cases was increased from 18.6% in 1994 to 54.2% in 1997, and the number of risk villages with a malaria incidence above 5% was reduced from 14 to 2 at the same time. The ratio of cost/benefit was 1:2.4 in 1995-1996 and 1:4.4 in 1997, showing a better economic benefit. CONCLUSION: The expectant result has been obtained, thereby providing new experience for the malaria control in the mountainous areas of Hainan Province.

China↗
PubMed1998

12-month Tai Chi training in the elderly: its effect on health fitness.

PURPOSE: The objective of this study was to evaluate the effect of Tai Chi Chuan (TCC) on health fitness in older individuals. METHODS: Thirty-eight community-dwelling persons aged 58 to 70 yr completed this study. The TCC group included 9 men and 11 women; the control group included 9 men and 9 women. The TCC group practiced TCC for 11.2+/-1.4 months, with the attendance of 4.6+/-1.3 times x wk(-1). Each session included 20 min of warm-up, 24 min of TCC practice, and 10 min of cooldown. The exercise intensity was 52-63% of the heart rate range. Cardiorespiratory function, strength, flexibility, and percent of body fat were evaluated before and at the end of this study. RESULTS: The male TCC group showed 16.1% increase in VO2max (P < 0.01), 11 degrees increase in thoracic/lumbar flexibility (P < 0.05), 18.1% increase in muscle strength of knee extensor (P < 0.01), and 15.4% increase of knee flexor (P < 0.05). The female TCC group showed 21.3% increase in VO2max (P < 0.01), 8.8 degrees increase in flexibility (P < 0.05), 20.3% increase in muscle strength of knee extensor (P < 0.05), and 15.9% increase of knee flexor (P < 0.05). The control group showed no significant change in these variables. CONCLUSIONS: The results indicate that a 12-month Tai Chi Chuan program is effective for improving health fitness of the elderly.

Aged↗
PubMed1998

Normal standards for cardiopulmonary responses to exercise using a cycle ergometer test.

The purpose of the study was to establish standards for cardiopulmonary responses to exercise in healthy Chinese subjects in Taiwan. One hundred and five sedentary healthy subjects, 55 men and 50 women aged between 20 and 75 years, were tested. They pedalled a cycle ergometer with the work rate increased by 10 W every minute until they were exhausted. Expiratory gas volume, oxygen concentration, carbon dioxide concentration, and heart rate were measured during the exercise test. Work rate (WRmax), oxygen consumption (VO2max), oxygen consumption divided by body weight (VO2max/BW), heart rate (HRmax), and ventilation (VEmax) at maximal exercise, and oxygen consumption at anaerobic threshold (VO2AT) were determined. These parameters were regressed by age (A, in year), height (H, in cm), body weight (G, in kg), and gender (S, 0 = women, and 1 = men), and the following predictive equations were obtained: 1) WRmax (W) = -1.2 A + 1.1 H + 0.7 G + 28 S - 56, R = 0.90; 2) VO2max (ml/min) = -20 A + 9.5 H + 16 G + 461 S - 237, R = 0.90; (3) VO2max/BW (ml/kg/min) = -0.31 A + 0.14 H - 0.14 G - 7.2 S + 22, R = 0.87; 4) HRmax (beat/min) = -0.81 A + 209, R = 0.61; 5) VEmax (L/min) = -0.74 A - 0.04 H + 0.93 G + 22.2 S + 42, R = 0.83; 6) VO2AT (ml/min) = -9.5 A + 3.5 H + 9.4 G + 140 S - 122, R = 0.79. Our results provide normal standards for cardiopulmonary responses to exercise during cycle ergometer testing in Taiwan.

Adult↗
PubMed1996

Cardiorespiratory function, flexibility, and body composition among geriatric Tai Chi Chuan practitioners.

OBJECTIVE: To evaluate the health-related fitness of geriatric Tai Chi Chuan (TCC) practitioners. DESIGN: Case-control study of a TCC group and a group of sedentary controls. SETTING: Research project at a hospital-based exercise physiology laboratory. PARTICIPANTS: Seventy-six community-dwelling senior persons (mean age 69.3 +/- 3.9 yr), a TCC group that included 22 men and 19 women and a control group of sedentary subjects that included 18 men and 17 women with matched age and body size. INTERVENTION: The TCC group had practiced TCC regularly for 11.8 +/- 5.6 years, with an exercise frequency of 4.3 +/- 1.3 times per week. Each session included 20 minutes of warm-up, 24 minutes of TCC training, and 10 minutes of cool-down. Exercise intensity was estimated to exceed 70% of maximal heart rate (HRmax). MAIN OUTCOME MEASURE: Breath-by-breath measurement of cardiorespiratory function was obtained during the incremental exercise of leg cycling. Flexibility of thoracic/lumbar spine was measured by an electronic inclinometer. Percentages of body fat was calculated from biceps and subcapsular skinfolds. RESULTS: In the peak exercise, men in the TCC group showed 19% higher peak oxygen uptake (VO2peak) in comparison with their sedentary counterparts (26.9 +/- 4.7 mL/kg/min vs 21.8 +/- 3.1 mL/kg/min). Women in the TCC group also showed 18% higher VO2peak than in the sedentary group (20.1 +/- 2.9 mL/kg/ min vs 16.5 +/- 2.0 mL/kg/min). The TCC group also showed higher oxygen uptake at the ventilatory threshold. In addition, the TCC practitioners were characterized by greater flexibility and lower percentage of body fat in comparison with their sedentary counterparts. CONCLUSION: It is concluded that TCC training has benefits for health-related fitness, and it may be prescribed as a suitable conditioning exercise for the elderly.

Aged↗
PubMed1996

[Quadrant pattern visual evoked potential in normal eyes].

OBJECTIVE: The study was designed to approach the difference in pattern visual evoked potential (PVEP) among quadrants of the normal eye. METHODS: Quadrant transient PVEP method was used to record quadrant PVEP for 70 eyes of 35 normal subjects. RESULTS: The latency of P100 in lower temporal and lower nasal fields was significantly shorter than that in upper temporal and upper nasal fields; the amplitude of P100 in lower temporal and lower nasal fields was significantly higher than that in upper temporal and upper nasal fields. Generally, in lower field, the P100's latency is shorter and its amplitude higher. CONCLUSION: The difference in P100 between upper and lower field of normal person is possibly related to the fact that the lower field is used more frequently than the upper in ordinary human or animal life, and to the differences in distribution of retinal ganglion cells and in retina-cortex pathway between the upper and lower retina.

Adult↗
PubMed1995

Social aspects of malaria in Heping, Hainan.

This paper presents findings from a study conducted in Heping Town, Qiongzhong County, Hainan Province, China. The study, conducted in 1992, used qualitative as well as quantitative methods to gather social, cultural and behavioural data associated with the acquisition, transmission and prevention of malaria, and the diagnosis and treatment of disease. These methods included focus groups, key informant and other in-depth interviews, and observations, a household survey and tests of school children of knowledge of malaria. The study is among the first to our knowledge that has utilized this broad mix of methods for tropical disease research in China.

Adolescent↗
PubMed1995

Two-year trends in cardiorespiratory function among older Tai Chi Chuan practitioners and sedentary subjects.

OBJECTIVE: To evaluate the training effects of Chinese shadow boxing, Tai Chi Chuan (TCC), on the maintenance of cardiorespiratory function in older individuals. DESIGN: Prospective study of a cohort of TCC practitioners and a group of sedentary controls examined 2 years after initial examination. SETTING: Research project at a hospital-based exercise physiology laboratory. PARTICIPANTS: Eighty-four community-dwelling older adults (mean age: 64 +/- 9 years) with no significant cardiovascular, pulmonary, and musculoskeletal disease completed this study. The TCC group, 23 male and 22 female subjects, had been practicing TCC regularly for 6.7 +/- 3.3 years. The control group included 21 male and 18 female sedentary subjects with age and body size matched to the TCC group. INTERVENTION: During the period of the study, the TCC practitioners practiced TCC 5.0 +/- 1.1 times per week. Each session included 20 minutes of warm up, 24 minutes of TCC training, and 10 minutes of cool down. The baseline cardiorespiratory function was recorded in the initial exercise test. The same measurements were repeated 2 years later to determine the rate of decline of cardiorespiratory function. Furthermore, heart rates (HR) were monitored in 18 men and 16 women during the performance of TCC to determine the exercise intensity of TCC. MAIN OUTCOME MEASURE: The study measured 2-year trends of cardiorespiratory function in both groups. RESULTS: In the TCC group, the males showed a 2.8% decrease in maximal oxygen uptake (VO2max) from 31.6 +/- 7.6 mL x kg-1 x min-1 to 30.7 +/- 7.1 mL x kg-1 x min-1; the females showed a 2.9% decrease in VO2 max from 20.7 +/- 2.3 mL x kg-1 x min-1 to 20.1 +/- 2.5 mL x kg-1 x min-1. In contrast, the male control group showed a 6.6% decrease in VO2max from 24.4 +/- 4.4 mL x kg-1 x min-1 to 22.8 +/- 4.4 mL x kg-1 x min-1; the females showed a 7.4% decrease in VO2max from 16.2 +/- 2.3 mL x kg-1 x min-1 to 15.0 +/- 2.7 mL x kg-1 x min-1. At the ventilatory threshold (VeT), the sedentary group also showed a significant decrease in VO2. During the steady-state performance of TCC, subjects' mean HR was approximately the HR at the VeT (53-57% of HRmax reserve). CONCLUSION: The data substantiate that practicing Tai Chi Chuan regularly may delay the decline of cardiorespiratory function in older individuals. In addition, TCC may be prescribed as a suitable aerobic exercise for older adults.

Aged↗
PubMed1995

Breathing-coordinated exercise improves the quality of life in hemodialysis patients.

Breathing-coordinated exercise is a traditional Chinese exercise. These exercise maneuvers consist of slow diaphragmatic breathing, end-inspiratory pause, and Kegel's exercise. A total of 30 patients were enrolled in this study, with 12 patients as controls, to evaluate its effect on hemodialysis patients. Exercise was performed for 25 to 30 min twice a day for at least 3 months. Results from the exercise group showed a subjective improvement in appetite and physical strength, and an increase in the frequency of bowel movements, in addition to enhanced sexual activity and a significant increase in Karnofsky scores. Six patients in the exercise group underwent bicycle ergometry and demonstrated a stable maximal oxygen consumption, whereas the control group revealed a decline in maximal oxygen consumption. Photoelectric plethysmography and laser-Doppler flowmetry demonstrated a pulsatile enhancement of the peripheral microcirculation. Abdominal sonography revealed an oscillatory change in the diameter of the inferior vena cava. It was concluded that these gentle exercise maneuvers may improve the quality of life in hemodialysis patients, especially weak dialysis patients. The mechanism may be partly related to an improvement in microcirculation.

Adult↗
PubMed1995

[A study on human behavior and socioeconomic factors affecting malaria transmission and control in Qiongzhong, Hainan].

This study was conducted in Heping District of Quiongzhong County, a hyperedemic mountainous area, in August-September 1992. The comparative surveys between the village and state-run farm, Li and Miao nationalities and Han nationality were carried out by using the sociological method together with the epidemiological methods. Gray relational analysis was conducted between the aforementioned 7 socioeconomic human behavioral factors and IFA rates. The result showed that their degrees of relation (r) were in the following order: (1) percentage of persons who had stayed in the mountain overnight (r = 0.8690); (2) percentage of bed net users (r = 0.7990); (3) percentage of households seeking medical service (r = 0.7990); (4) number of mosquito nets per person (r = 0.7867); (5) percentage of householders knowing malaria transmission route (r = 0.7798); (6) percentage of households with tile-roofed houses (r = 0.6767) and (7) income per capita (r = 0.6636). It indicates that staying in the mountain, using bed net and seeking medical service were three discriminating factors affecting local malaria transmission and control. Therefore, it is suggested that carrying out health education, changing the stay-in-mountain behavior, increasing the utilization of mosquito nets and reinforcing the primary health care should be taken as the fundamental measures for malaria control programme.

China↗
PubMed1993

Traumatic spinal cord injuries in the rural region of Taiwan: an epidemiological study in Hualien county, 1986-1990.

In order to survey the epidemiological characteristics of traumatic spinal cord injuries (SCI) in Hualien county, a retrospective study was conducted from January 1986 to December 1990 in four local general hospitals. During this period, 135 traumatic SCI patients were identified and 99 of them were residents of Hualien county. The estimated annual incidence of traumatic SCI in Hualien county was 56.1 per million population. As a result of injury 36 patients were tetraparetic, 33 tetraplegic, 12 paraparetic and 18 paraplegic. The male/female ratio was 4:1. The mean age of onset for male patients was 44 years, and that for female patients was 46 years. The major causes of SCI were traffic accident (61.6%) followed by accidental falls (23.3%). The average duration of hospitalisation ranged from 62 days in paraparetics to 132 days in tetraplegics. Ten patients died of respiratory failure or sepsis, and the mortality rate was 10.1%. Our data revealed that traumatic SCI was prevalent in Hualien county in comparison with epidemiological studies elsewhere. The special population composition of Hualien county and the preponderance of the motorcycle as a transportation vehicle in this area might result in its unique epidemiological characteristics.

Accidental Falls↗
PubMed1993

Cardiorespiratory responses of Tai Chi Chuan practitioners and sedentary subjects during cycle ergometry.

Tai Chi Chuan (TCC; shadow boxing) is a traditional Chinese conditioning exercise. To evaluate its beneficial effect on cardiorespiratory function, 21 male and 20 female TCC practitioners, ranging in age from 50 to 64 years, voluntarily participated in this study. The control group comprised 23 male and 26 female sedentary subjects. Breath-by-breath measurement of the cardiorespiratory function was obtained during the incremental exercise of leg cycling. At the maximal exercise level, the oxygen uptake (VO2), O2 pulse and work rate of the TCC group were significantly higher than the respective values of the control group (p < 0.01). At the ventilatory threshold, the TCC group also showed a higher VO2, O2 pulse and work rate (p < 0.05). The results imply that TCC training may be beneficial to the cardiorespiratory function of older individuals. To estimate the exercise intensity of TCC, heart rate (HR) was monitored in 15 men and 15 women while they performed the classical Yang TCC. During the steady-state performance of TCC, the mean HR was 130 +/- 14 bpm for men and 127 +/- 13 bpm for women. The mean HR during TCC exceeded 70% of their HRmax. Our data substantiate that TCC is aerobic exercise of moderate intensity, and it may be prescribed as a suitable conditioning exercise for the elderly.

Exercise↗
PubMed1990

[Progressive supranuclear palsy: clinical report on 7 cases and review of literature].

Progressive supranuclear palsy is sufficiently rare and difficult to diagnose that it escaped clinical recognition until 1964, when Steele, Richardson, and Olszewski clarified it as a pathologic entity. From January 1981 to June 1989, 7 patients who fulfilled the Golbe's criteria of progressive supranuclear palsy were admitted to the neurological department of National Taiwan University Hospital. The mean age at onset was 60 years (range: 53-69 years), and the mean age at diagnosis was 63 years), and the mean age at diagnosis was 63 years (range: 55-71 years). The study failed to identify any specific risk factors associated with progressive supranuclear palsy. Unsteady gait, vertical gaze palsy, pseudobulbar palsy, parkinsonian features and dementia were noted in all cases. The brain computed tomography revealed mild cortical atrophy and ventricular dilatation in 5 patients. Additionally, electroencephalography revealed diffuse theta waves in 4 patients and temporal theta waves in 2 patients, but these findings were nonspecific. Nystagmograms were performed in 3 patients, and hypometric saccades were noted in all of these patients, and uninhibited neurogenic bladder was proven by cystometry in 2 of these patients. All patients were treated with levodopa, but none of the patients showed any beneficial effects. Two patients died of aspiration pneumonia; the average duration from onset to death was about 4 years.

Aged↗