Biomedical subjects

Fanny W S Ko

Publications and source records attributed to Fanny W S Ko.

13 recordsLinked to original sources

PubMed2007

A 1-year prospective study of the infectious etiology in patients hospitalized with acute exacerbations of COPD.

INTRODUCTION: Infection is a major cause of acute exacerbations of COPD (AECOPDs). We aimed to study the infectious etiology related to AECOPD. METHODS: Patients admitted to an acute care hospital in Hong Kong with an AECOPD were recruited prospectively from May 1, 2004, to April 30, 2005. Sputum samples, nasopharyngeal aspirate (NPA) samples, and paired serology specimens were collected. Spirometry was performed with patients in the stable phase 2 to 3 months after hospital discharge. RESULTS: There were 643 episodes of AECOPD among 373 patients. Their mean age was 75.3 years (SD, 7.9 years) with 307 male patients. The mean FEV(1) was 40.4% predicted (SD, 18.7% predicted), and the mean FEV(1)/FVC ratio was 58.4% (SD, 16.0%). Among sputum samples from the 530 episodes of AECOPD hospital admissions that were saved, 13.0%, 6.0%, and 5.5%, respectively, had positive growth of Haemophilus influenzae, Pseudomonas aeruginosa, and Streptococcus pneumoniae. Among the 505 hospital admissions with patients who had NPA samples saved, 5.7%, 2.3%, 0.8%, and 0.8%, respectively, had influenza A, respiratory syncytial virus (RSV), influenza B, and parainfluenza 3 isolated from viral cultures. Paired serology test results revealed a fourfold rise in viral titers in 5.2%, 2.2%, and 1.4% of patients, respectively, for influenza A, RSV, and influenza B. Very severe airflow obstruction (stable-state spirometry) was associated with a higher chance of a positive sputum culture (FEV(1) >/= 30% predicted, 28.2%; FEV(1) < 30% predicted, 40.4%; p = 0.006). CONCLUSION: H influenzae and influenza A were the most common etiologic agents in patients who were hospitalized with AECOPDs. More severe airflow obstruction was associated with a higher chance of a positive sputum culture finding.

Aged↗

PubMed2006

Aberrant expression of CC and CXC chemokines and their receptors in patients with asthma.

This study further elucidates the roles of selected chemokines (IP-10, MIG, and RANTES) and their receptors (CCR3, CCR5, and CXCR3) in asthma. We compared their profiles in six groups of participants-atopic cohort and nonatopic cohort (each including controls and asthmatic patients with or without steroid therapy). Plasma concentration of IP-10 was significantly lower while that of RANTES and the expression of CCR3 were higher in asthmatic patients (all p < 0.05). Plasma RANTES correlated positively with the GINA severity score in all asthmatic patients (r=0.27, p < 0.05), and with IL-13 in nonatopic asthmatic patients (r=0.46, p < 0.05). In asthmatic patients, the ex vivo release of IP-10 and MIG was attenuated in PBMC activated with allergen, mitogens and IL-18 (p < 0.05). In conclusion, plasma RANTES may be a surrogate marker for asthma and the diminished Th1 related CXC chemokine production may contribute to Th2 predominance in asthma.

Adult↗

PubMed2006

12-year change in prevalence of respiratory symptoms in elderly Chinese living in Hong Kong.

Respiratory diseases may cause considerable disability in the elderly because of their limited respiratory reserve related to aging. This study aimed to assess the time trend of respiratory symptoms and common chronic respiratory diseases in the elderly Chinese living in Hong Kong. Two questionnaire surveys were conducted in 1991-1992 and 2003-2004. Subjects aged > or = 70 years were invited to complete a respiratory questionnaire. A total of 2032 (999 male) and 1524 (698 male) subjects completed the questionnaire surveys in 1991 and 2003, respectively. The response rates were 60% in 1991 and 78% in 2003. The prevalence of most respiratory symptoms increased over time after adjusting the data for age, sex, social status and smoking habits. Comparing the symptoms between 1991 and 2003, wheeze over the past 12 months increased from 7.5 to 12.1% (adjusted OR 2.00, 95% CI 1.54-2.61) and morning chest tightness from 4.2 to 8.8% (adjusted OR 2.48, 95% CI 1.79-3.43). The prevalence of self-reported physician-diagnosed emphysema increased over time (2.4-3.1%, adjusted OR 1.78, 95% CI 1.12-2.86), but there was no change for asthma (5.1% in 1991 and 5.8% in 2003) or chronic bronchitis (6.7% in 1991 and 7.7% in 2003). The prevalence of respiratory symptoms has increased over the past 12 years and this may be related to environmental factors especially increasing air pollution in Hong Kong.

Aged↗

PubMed2006

Sleep-disordered breathing and continuous positive airway pressure compliance in a group of commercial bus drivers in Hong Kong.

OBJECTIVE AND BACKGROUND: Sleep-disordered breathing may predispose drivers to road traffic accidents. However, CPAP acceptance and compliance among commercial bus drivers is unknown. METHODS: We conducted a sleep questionnaire survey at a bus depot followed by random selection of bus drivers for home sleep study with the mesam iv device. Bus drivers with a respiratory disturbance index (RDI)>or=5/h were invited to have hospital-based polysomnography for confirmation followed by nasal CPAP treatment. RESULTS: Out of 1477 bus drivers, 1016 (971 men) were interviewed with mean (SD) age of 45.3 (7.5) years, BMI 24.9 (3.6) kg/m2, neck circumference 38.9 (3.1) cm and Epworth sleepiness score 4.8 (4.0). Sleepiness at work was reported by 60.9%, snoring>or=3 nights per week 23.9%, witnessed apnoea 3.7% and having fallen asleep during driving by 24%. Among 211 who underwent home sleep study, 85 (40.3%), 55 (26.1%) and 37 (17.5%) had RDI>or=5, >or=10 and >or=15/h respectively. BMI, snoring intensity and neck circumference were the positive independent factors associated with the RDI. Of the 25 drivers who attended polysomnography, nine accepted CPAP prescription with improvement of Epworth sleepiness score, trail B and digit span after 3 months with CPAP usage of 4.5 (1.3) h/night. CONCLUSION: The estimated minimum prevalence rates of sleep-disordered breathing and obstructive sleep apnoea syndrome were 8.4% and 5.4% respectively among the bus drivers. Home CPAP acceptance was low among bus drivers with sleep apnoea but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.

Accidents, Traffic↗

PubMed2005

Exhaled breath condensate levels of 8-isoprostane, growth related oncogene alpha and monocyte chemoattractant protein-1 in patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) patients have increased neutrophils and macrophages in their lungs, and inflammation of the airway is related to oxidative stress. This study assessed the levels of 8-isoprostane (an oxidative stress marker) and chemokines related to neutrophil and monocyte inflammation (growth-related oncogene alpha [GROalpha] and monocyte chemoattractant protein-1 [MCP-1]) in the airway of ex-smoking COPD patients by exhaled breath condensate (EBC) collection. Thirty-two (28 males) stable COPD patients (14 with FEV(1) 50% [Group 1], 18 with FEV(1) <50% predicted [Group 2]) and 18 non-smoking age and sex-matched controls were studied in this cross-sectional study. EBC was collected using the EcoScreen (Jaeger, Germany) during 10 min of tidal breathing with the nose clipped. Concentrations of 8-isoprostane, GROalpha and MCP-1 were measured by enzyme immunoassays. COPD patients had a higher concentration of 8-isoprostane than controls (COPD versus control, P<0.001; Group 1 versus Group 2, P=0.045). 8-isoprostane increased across the groups from normal, Group 1 to Group 2 (r=0.64, P<0.001). The median intraquartile range (IQR) levels in pg/ml for GROalpha were 45.3(44.5-46.5), 45.4(44.5-46.0), 46.0(45.6-47.3), whereas MCP-1 levels were 5.3(5.2-5.9), 6.2(5.4-6.9) and 5.7(5.5-6.4) in Group 1, Group 2 COPD and control subjects, respectively. GROalpha level was lower in COPD patients when compared to controls (P=0.01). MCP-1 level did not differ between COPD and the control group. 8-isoprostane level, but not GROalpha and MCP-1, in EBC was increased in COPD patients with poorer lung function. This suggests an increased oxidative stress in the airway in patients with more severe COPD.

Aged↗

PubMed2005

Analysis of growth factors and inflammatory cytokines in exhaled breath condensate from asthmatic children.

BACKGROUND: Vascular endothelial growth factor (VEGF), AA isoform of platelet-derived growth factor (PDGF-AA), and epidermal growth factor (EGF) are involved in the pathogenesis of airway inflammation in asthma. These molecules are closely associated with cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-4. This study investigates the relation between childhood asthma and levels of these mediators in exhaled breath condensate (EBC). METHODS: EBC was collected from asthmatic children and controls using a disposable collection kit, and the concentrations of VEGF, PDGF-AA, EGF, TNF-alpha and IL-4 in EBC were measured using sandwich enzyme immunoassays. Exhaled nitric oxide concentration was measured by a chemiluminescence analyzer. RESULTS: Thirty-five asthmatic patients aged between 7 and 18 years and 11 controls were recruited. Sixteen patients had intermittent asthma (IA) whereas 19 of them suffered from persistent asthma (PA). A significant correlation was found between IL-4 and TNF-alpha in EBC (rho = 0.374, p = 0.010). PDGF-AA levels in EBC were higher in subjects with diminished FEV1 (p = 0.023) whereas IL-4 concentrations were increased in asthmatics (p = 0.007) as well as subjects with increased plasma total IgE (p = 0.033). Patients with PA receiving high-dose inhaled corticosteroid (ICS) had higher EBC IL-4 concentration than those on low-dose ICS (p = 0.007). Linear regression revealed that PDGF-AA levels in EBC were negatively associated with FEV1 percentage (beta = -0.459, p = 0.006) among the asthmatic patients. CONCLUSIONS: IL-4 in EBC is increased in childhood asthma, and growth factors are detectable in a significant proportion of these children. Increased PDGF-AA is found in asthmatics with more severe airflow limitation.

Adolescent↗

PubMed2005

Sputum bacteriology in patients with acute exacerbations of COPD in Hong Kong.

STUDY OBJECTIVE: To study the demographics and sputum microbiology of patients admitted to a teaching hospital with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). DESIGN: A retrospective study. SETTING: A tertiary university hospital in Hong Kong. PATIENTS: All episodes of AECOPD, patient demographics, length of stay, sputum culture and radiological results admitted in the first half of the year 2000 were retrieved from hospital records. RESULTS: There were 329 patients with 418 episodes of AECOPD without concomitant pneumonia. The age of the patients was 74.4+/-8.3 years. The acute hospital length of stay for an episode of AECOPD was 7.3+/-6.5 days. Haemophilus influenzae was the commonest organism found in sputum (23.1%), followed by Pseudomonas aeruginosa (6.3%) and Streptococcus pneumoniae (4.0%). Mycobacterium tuberculosis was found in 1.1% of the admissions. Presence of organisms in sputum had no association with the hospital length of stay and intensive care unit admissions. In patients whose FEV1 was >50% of predicted values, there was a higher chance of positive sputum growth of H. influenzae than those with FEV1 <50% (16/44 vs. 31/162 episodes, respectively, P=0.02). CONCLUSIONS: H. influenzae was the commonest bacterium isolated in sputum in patients with AECOPD. In areas endemic of tuberculosis, it is advisable to use fluoroquinolones for AECOPD with caution.

Acute Disease↗

PubMed2005

A comparison of airway and serum matrix metalloproteinase-9 activity among normal subjects, asthmatic patients, and patients with asthmatic mucus hypersecretion.

BACKGROUND: The rate of decline in lung function is increased in asthmatic patients, particularly in those with coexisting asthmatic mucus hypersecretion (AMH), in whom inflammation and the activity of matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in serum and BAL fluid (BALF) may be increased. METHODS: Seven nonasthmatic subjects and 22 asthmatic subjects completed a questionnaire, and underwent lung function testing and bronchoscopy, during which AMH was diagnosed by the presence of mucus plugging. Subjects were classified as follows: mild/moderate asthma; severe asthma; and AMH. In BALF, we measured the differential WBC counts and MMP-9 activity by zymography. We measured total MMP-9 and TIMP-1 activity by enzyme-linked immunosorbent assay in BALF and serum. RESULTS: The mean (+/- confidence interval) FEV1 was lower in AMH patients (73 +/- 13% predicted) compared with nonasthmatic subjects (95 +/- 7%) and patients with mild/moderate asthma (73 +/- 9%; p < 0.05), and was similar to that of patients with severe asthma (80 +/- 20%). MMP-9 activity was greater in AMH patients and in patients with severe asthma compared with nonasthmatic subjects (p = 0.05 and p = 0.01, respectively), as were TIMP-1 activities (p = 0.001 and p = 0.04, respectively), but MMP-9/TIMP-1 ratios were not. MMP-9 activity increased across the four groups from nonasthmatic subjects to AMH patients (r = 0.58; p = 0.0009), but the differential and total WBC counts were similar. There were no relationships between FEV1 percent predicted and either MMP-9 activity or MMP-9/TIMP-1 ratio. There were no differences in serum MMP-9 activity, which did not correlate with MMP-9 activity in BALF. CONCLUSIONS: AMH and severe asthma were associated with greater proteolytic enzyme activities despite similar airway inflammation, which might play a role in remodeling and accelerated the decline in lung function in these patients.

Analysis of Variance↗

PubMed2004

Factors associated with difference in prevalence of asthma in children from three cities in China: multicentre epidemiological survey.

OBJECTIVE: To determine the factors associated with difference in prevalence of asthma in children in different regions of China. DESIGN: Multicentre epidemiological survey. SETTING: Three cities in China. PARTICIPANTS: 10,902 schoolchildren aged 10 years. MAIN OUTCOME MEASURES: Asthma and atopic symptoms, atopic sensitisation, and early and current exposure to environmental factors. RESULTS: Children from Hong Kong had a significantly higher prevalence of wheeze in the past year than those from Guangzhou and Beijing (odds ratio 1.64, 95% confidence interval 1.35 to 1.99). Factors during the first year of life and currently that were significantly associated with wheeze were cooking with gas (odds ratio 2.04, 1.34 to 3.13), foam pillows (2.58, 1.66 to 3.99), and damp housing (1.89, 1.26 to 2.83). Factors protecting against wheeze were cotton quilts and the consumption of fruit and raw vegetables. CONCLUSION: Environmental factors and diet may explain the differences in prevalence of asthma between children living in different regions of China.

Asthma↗

PubMed2004

Early results of endoscopic lung volume reduction for emphysema.

BACKGROUND: We determined the feasibility, safety, and short-term efficacy of bronchoscopic placement of a one-way endobronchial valve in selected bronchopulmonary segments as an alternative to surgical lung volume reduction. METHODS: A total of 21 patients with incapacitating emphysema who underwent this procedure were studied. All patients had placement of the endobronchial valves into the most emphysematous lung segments. We recorded any major complications or deaths attributed to the procedure and analyzed (1) improvements in the spirometric and functional parameters and quality of life and (2) the radiologic changes compared with the baseline data at 30 and 90 days. RESULTS: A total of 20 patients had complete follow-up data. There was no mortality in the group studied. The forced expiratory volume at 1 second, forced expiratory volume at 1 second (percentage of predicted), forced vital capacity, and forced vital capacity (percentage of predicted) all improved significantly at 90 days (0.73 +/- 0.26 L vs 0.92 +/- 0.34 L [P =.009]; 33.3% +/- 11.9% vs 42.2% +/- 15.0% [P =.006]; 1.94 +/- 0.62 L vs 2.25 +/- 0.61 L [P =.015]; and 63.3% +/- 17.6% vs 73.9% +/- 17.1% [P =.012], respectively). The 6-minute walking distance improved at 30 and 90 days (251.6 +/- 100.2 m vs 306.3 +/- 112.3 m and 322.3 +/- 129.7 m; P =.012 and P =.003). The results of the 36-Item Short-Form Health Survey and the St George Respiratory Questionnaire showed significant improvements at 90 days. The Medical Research Council dyspnea grade also improved significantly at 30 and at 90 days (P =.006 and P =.003, respectively). CONCLUSIONS: Endobronchial valve placement is a safe procedure, with significant short-term improvements in functional status, quality of life, and relief of dyspnea in selected patients with emphysema. A larger study with long-term follow-up is therefore warranted.

Adult↗

PubMed2002

Severe obstructive sleep apnea is associated with left ventricular diastolic dysfunction.

INTRODUCTION: Hypertension is common in patients with obstructive sleep apnea (OSA). However, the effect of OSA on ventricular function, especially diastolic function, is not clear. Therefore, we have assessed the prevalence of diastolic dysfunction in patients with OSA and the relationship between diastolic parameters and severity of OSA. METHODS: Sixty-eight consecutive patients with OSA confirmed by polysomnography underwent echocardiography. Diastolic function of the left ventricle was determined by transmitral valve pulse-wave Doppler echocardiography. Various baseline characteristics, severity of OSA, and echocardiographic parameters were compared between patients with and without diastolic dysfunction. RESULTS: There were 61 male and 7 female patients with a mean age of 48.1 +/- 11.1 years, body mass index of 28.5 +/- 4.3 kg/m(2), and apnea/hypopnea index (AHI) of 44.3 +/- 23.2/h (mean +/- SD). An abnormal relaxation pattern (ARP) in diastole was noted in 25 patients (36.8%). Older age (52.7 +/- 8.9 years vs 45.1 +/- 11.3 years, p = 0.005), hypertension (56% vs 20%, p = 0.002), and a lower minimum pulse oximetric saturation (SpO(2)) during sleep (70.5 +/- 17.9% vs 78.8 +/- 12.9%, respectively; p = 0.049) were more common in patients with ARP. By multivariate analysis, minimum SpO(2) < 70% was an independent predictor of ARP (odds ratio, 4.34; 95% confidence interval, 1.23 to 15.25; p = 0.02) irrespective of age and hypertension. Patients with AHI > or = 40/h had significantly longer isovolumic relaxation times than those with AHI < 40/h (106 +/- 19 ms vs 93 +/- 17 ms, respectively; p = 0.005). CONCLUSION: Diastolic dysfunction with ARP was common in patients with OSA. More severe sleep apnea was associated with a higher degree of left ventricular diastolic dysfunction in this study.

Diastole↗

PubMed2002

Prevalence of sleep-disordered breathing and continuous positive airway pressure compliance: results in chinese patients with first-ever ischemic stroke.

OBJECTIVE: To assess the prevalence of sleep-disordered breathing (SDB), continuous positive airway pressure (CPAP) acceptance, and CPAP compliance in patients who have experienced ischemic stroke. DESIGN: A case-controlled study. SETTING: A university hospital. MEASUREMENTS AND RESULTS: We recruited 23 women and 28 men, who were admitted to the hospital within 4 days of stroke onset, with a mean (+/- SD) age of 64.2 +/- 13.0 years and a body mass index (BMI) of 24.3 +/- 4.4 kg/m(2) for this study. Twenty-seven patients (53%) and 9 patients (17.6%), respectively, reported a history of snoring and severe daytime sleepiness prior to experiencing a stroke, while the mean Epworth sleepiness scale score was 6.8 +/- 3.6. Polysomnography revealed 34 patients (67%) with an apnea-hypopnea index (AHI) of > or = 10 events per hour, 31 patients (61%) with an AHI of > or = 15 events per hour, and 25 patients (49%) with an AHI of > or = 20 events per hour. Significant obstructive SDB, defined as an AHI of > or = 20/h, was more prevalent in ischemic stroke patients than in control subjects (49% vs 24%, respectively; p = 0.04) and was associated with a higher BMI (p = 0.046). Among the 34 patients with an AHI of > or = 10/h, CPAP titration was tolerated by 16 patients, but only 4 patients who had typical sleep apnea features proceeded to home CPAP treatment with objective compliance over a period of 3 months of 2.5 +/- 0.6 h per night. A subgroup of 20 patients not receiving CPAP showed partial spontaneous improvement of SDB at 1 month (baseline AHI, 32.3 +/- 17.6 events per hour; AHI at 1 month, 23.0 +/- 18.8 events per hour; p = 0.01) with a trend toward improvement for the obstructive but no significant change for the central events, whereas no improvement in AHI was noted for the four patients receiving CPAP. CONCLUSION: There is a high prevalence of obstructive SDB in patients who have experienced acute ischemic stroke, which, in many cases, is different from classic obstructive sleep apnea syndrome, and this is reflected by the lack of significant sleepiness, poor CPAP acceptance, and partial spontaneous improvement at 1 month.

Aged↗

PubMed2002

Prevalence of sleep disturbances in Chinese patients with end stage renal failure on maintenance hemodialysis.

BACKGROUND: Sleep disorders, such as daytime sleepiness, insomnia, restless legs syndrome (RLS) and obstructive sleep apnea syndrome (OSAS) have been reported as prevalent among patients with end stage renal failure(ESRF). MATERIAL/METHODS: As there is little published data from Southeast Asia, a sleep questionnaire was administered to all patients (N=43, 27 males) on chronic hemodialysis (HD) at the Prince of Wales Hospital, Hong Kong, to assess their sleep complaints. RESULTS: The mean age was 49.5 +/- 11.3 years (mean I SD) with mean body mass index (BMI) of 22.6 +/- 3.6 kg/m2. Frequent awakenings and sleep onset insomnia were the most frequent complaints (79% each), while daytime sleepiness occurred in 74% of patients. Sleep maintenance insomnia and pruritus occurred in 64% and 60% of patients respectively. Symptoms of RLS were reported by 70% of patients. The prevalence of OSAS was estimated by the frequency of observed choking (4.7% of cases), witnessed apnea (14%), snoring and witnessed apnea (9.3%), disruptive snoring (14%), disruptive snoring and witnessed apnea (2.3%), extremely loud snoring (4.7%). CONCLUSIONS: Our questionnaire survey revealed a high prevalence of sleep complaints such as frequent awakenings, daytime sleepiness, insomnia and RLS in patients with ESRF on maintenance HD, but a relatively low prevalence of OSAS, which may be related to the low BMI of our ESRF patients.

Adult↗