76
|
Zaidi M, Azuhairy, Chan CK. Functional Results after Anterior Cruciate Ligament Reconstruction using the bone-patella Tendon-bone Method. Malays Orthop J 2008. [DOI: 10.5704/moj.0804.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
77
|
Hou M, Tu H, Liu R, Li Y, Lu K, Lai PY, Chan CK. Temperature oscillations in a compartmentalized bidisperse granular gas. PHYSICAL REVIEW LETTERS 2008; 100:068001. [PMID: 18352518 DOI: 10.1103/physrevlett.100.068001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Indexed: 05/26/2023]
Abstract
A granular clock is observed in a vertically vibrated compartmentalized granular gas composed of two types of grains with the same size. The dynamics of the clock is studied in terms of an unstable evaporation or condensation model for the granular gas. In this model, the temperatures of the two types of grains are considered to be different, and they are functions of the composition of the gas. Oscillations in the system are driven by the asymmetric collisions properties between the two types of grains. Both our experiments and model show that the transition of the system from a homogeneous state to an oscillatory state is via a Hopf bifurcation.
Collapse
|
78
|
Cook MA, Chan CK, Jorgensen P, Ketela T, So D, Tyers M, Ho CY. Systematic validation and atomic force microscopy of non-covalent short oligonucleotide barcode microarrays. PLoS One 2008; 3:e1546. [PMID: 18253494 PMCID: PMC2212718 DOI: 10.1371/journal.pone.0001546] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 01/02/2008] [Indexed: 01/25/2023] Open
Abstract
Background Molecular barcode arrays provide a powerful means to analyze cellular phenotypes in parallel through detection of short (20–60 base) unique sequence tags, or “barcodes”, associated with each strain or clone in a collection. However, costs of current methods for microarray construction, whether by in situ oligonucleotide synthesis or ex situ coupling of modified oligonucleotides to the slide surface are often prohibitive to large-scale analyses. Methodology/Principal Findings Here we demonstrate that unmodified 20mer oligonucleotide probes printed on conventional surfaces show comparable hybridization signals to covalently linked 5′-amino-modified probes. As a test case, we undertook systematic cell size analysis of the budding yeast Saccharomyces cerevisiae genome-wide deletion collection by size separation of the deletion pool followed by determination of strain abundance in size fractions by barcode arrays. We demonstrate that the properties of a 13K unique feature spotted 20 mer oligonucleotide barcode microarray compare favorably with an analogous covalently-linked oligonucleotide array. Further, cell size profiles obtained with the size selection/barcode array approach recapitulate previous cell size measurements of individual deletion strains. Finally, through atomic force microscopy (AFM), we characterize the mechanism of hybridization to unmodified barcode probes on the slide surface. Conclusions/Significance These studies push the lower limit of probe size in genome-scale unmodified oligonucleotide microarray construction and demonstrate a versatile, cost-effective and reliable method for molecular barcode analysis.
Collapse
|
79
|
Yee YK, Cheung TK, Chu KM, Chan CK, Fung J, Chan P, But D, Hung I, Chan AOO, Yuen MF, Hsu A, Wong BCY. Clinical trial: levofloxacin-based quadruple therapy was inferior to traditional quadruple therapy in the treatment of resistant Helicobacter pylori infection. Aliment Pharmacol Ther 2007; 26:1063-7. [PMID: 17877513 DOI: 10.1111/j.1365-2036.2007.03452.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The efficacy of levofloxacin-based quadruple therapy in resistant Helicobacter pylori infection is not known. AIM To test the efficacy of levofloxacin-based quadruple therapy and traditional quadruple therapy in resistant H. pylori infection. METHODS One hundred and two patients with resistant H. pylori infection were randomized to 1 week of either EBAL (esomeprazole 40 mg b.d., bismuth subcitrate 240 mg b.d., amoxicillin 1 g b.d. and levofloxacin 500 mg b.d.) or EBMT (esomeprazole 40 mg b.d., bismuth subcitrate 240 mg b.d., metronidazole 400 mg t.d.s. and tetracycline 500 mg q.d.s.). (13)C-urea breath test was performed at week 12 to assess post-treatment H. pylori status. RESULTS In intention-to-treat analysis H. pylori eradication was achieved in 37 of 51 (73%) subjects in EBAL and 45 of 51 (88%) subjects in EBMT groups, respectively (P = 0.046). Per-protocol eradication rates of EBAL and EMBT groups were 78% and 94%, respectively (P = 0.030). The intention-to-treat eradication rate was statistically lower for EBAL than EMBT (56% vs. 90%, P = 0.013) among those who had failed more than one course of eradication therapy. Previous levofloxacin triple therapy did not affect the efficacy of either protocol significantly. CONCLUSIONS Levofloxacin-based quadruple therapy was inferior to traditional quadruple therapy for resistant H. pylori infection.
Collapse
|
80
|
Chan CK. Ocular manifestation of West Nile virus: a vanishing disease in North America? CANADIAN JOURNAL OF OPHTHALMOLOGY 2007; 42:195-8. [PMID: 17392841 DOI: 10.3129/can j ophthalmol.i07-010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
|
81
|
Chien FT, Lin SG, Lai PY, Chan CK. Observation of two forms of conformations in the reentrant condensation of DNA. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:041922. [PMID: 17500936 DOI: 10.1103/physreve.75.041922] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 01/11/2007] [Indexed: 05/15/2023]
Abstract
Reentrant condensation of DNA in the presence of spermidine (SPD) is studied by gel electrophoresis (GEP). It is found that the reentrant condensation of DNA induced by SPD can produce a reentrant jamming of DNA molecules at the liquid-gel interface during GEP. However, not all the DNA are jammed at the interface indicating that there are different forms of condensed DNA. A model of condensed DNA consisting of two conformations can be used to explain the experimental observations. A phase diagram of the reentrant condensation based on the jamming states of DNA in terms of the length of DNA (L) and concentration of SPD is constructed. Furthermore, no charge inversion is observed during the reentrant transition.
Collapse
|
82
|
Yu CM, Chan YS, Zhang Q, Yip GWK, Chan CK, Kum LCC, Wu L, Lee APW, Lam YY, Fung JWH. Benefits of Cardiac Resynchronization Therapy for Heart Failure Patients With Narrow QRS Complexes and Coexisting Systolic Asynchrony by Echocardiography. J Am Coll Cardiol 2006; 48:2251-7. [PMID: 17161255 DOI: 10.1016/j.jacc.2006.07.054] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Revised: 07/14/2006] [Accepted: 07/17/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVES This study was designed to evaluate the role of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with narrow QRS complexes (<120 ms) and echocardiographic evidence of mechanical asynchrony. BACKGROUND Cardiac resynchronization therapy is currently recommended to advanced HF patients with prolonged QRS duration. Echocardiographic assessment of systolic mechanical asynchrony has been proven useful to predict a favorable response after CRT. METHODS A total of 102 HF patients with New York Heart Association (NYHA) functional class III or IV were enrolled. Among them, 51 had wide QRS (>120 ms) and 51 had narrow QRS (<120 ms). Tissue Doppler imaging (TDI) was employed to select patients with systolic asynchrony (increased asynchrony index) in the narrow-QRS group. Clinical and echocardiographic assessments were performed at baseline and 3 months after CRT. RESULTS There was a significant reduction of left ventricular (LV) end-systolic volume in both narrow (122 +/- 42 cc vs. 103 +/- 47 cc, p < 0.001) and wide (148 +/- 74 cc vs. 112 +/- 64 cc, p < 0.001) QRS groups. Improvement of NYHA functional class (both p < 0.001), maximal exercise capacity (both p < 0.05), 6-min hall-walk distance (both p < 0.01), ejection fraction (both p < 0.001), and mitral regurgitation (both p < 0.005) was also observed. In both groups, the degree of baseline mechanical asynchrony determined LV reverse remodeling to a similar extent, as shown by the superimposed regression lines. Withholding CRT for 4 weeks resulted in loss of echocardiographic benefits. CONCLUSIONS Cardiac resynchronization therapy for HF patients with narrow QRS complexes and coexisting mechanical asynchrony by TDI results in LV reverse remodeling and improvement of clinical status. The amplitude of benefit is similar to the wide-QRS group provided that similar extent of systolic asynchrony is selected.
Collapse
|
83
|
Hu WHC, Lam SK, Lam CLK, Wong WM, Lam KF, Lai KC, Wong YH, Wong BCY, Chan AOO, Chan CK, Leung GM, Hui WM. Comparison between empirical prokinetics, Helicobacter test-and-treat and empirical endoscopy in primary-care patients presenting with dyspepsia: A one-year study. World J Gastroenterol 2006; 12:5010-6. [PMID: 16937497 PMCID: PMC4087404 DOI: 10.3748/wjg.v12.i31.5010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the optimal strategy to treat dyspeptic patients in primary care.
METHODS: Dyspeptic patients presenting to primary care outpatient clinics were randomly assigned to: (1) empirical endoscopy, (2) H pylori test-and-treat, and (3) empirical prokinetic treatment with cisapride. Early endoscopy was arranged if patients remained symptomatic after 2 wk. Symptom severity, quality-of-life (SF-36) as well as patient preference and satisfaction were assessed. All patients underwent endoscopy by wk 6. Patients were followed up for one year.
RESULTS: Two hundred and thirty four patients were recruited (163 female, mean age 49). 46% were H pylori positive. 26% of H pylori tested and 25% of empirical prokinetic patients showed no improvement at wk 2 follow-up and needed early endoscopy. 15% of patients receiving empirical cisapride responded well to treatment but peptic ulcer was the final diagnosis. Symptom resolution and quality-of-life were similar among the groups. Costs for the three strategies were HK$4343, $1771 and $1750 per patient. 66% of the patients preferred to have early endoscopy.
CONCLUSION: The three strategies are equally effective. Empirical prokinetic treatment was the least expensive but peptic ulcers may be missed with this treatment. The H pylori test-and-treat was the most cost-effective option.
Collapse
|
84
|
Lai PY, Jia LC, Chan CK. Growth of cortical neuronal network in vitro: modeling and analysis. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:051906. [PMID: 16802966 DOI: 10.1103/physreve.73.051906] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 03/06/2006] [Indexed: 05/10/2023]
Abstract
We present a detailed analysis and theoretical growth models to account for recent experimental data on the growth of cortical neuronal networks in vitro [Phys. Rev. Lett. 93, 088101 (2004)]. The experimentally observed synchronized firing frequency of a well-connected neuronal network is shown to be proportional to the mean network connectivity. The growth of the network is consistent with the model of an early enhanced growth of connection, but followed by a retarded growth once the synchronized cluster is formed. Microscopic models with dominant excluded volume interactions are consistent with the observed exponential decay of the mean connection probability as a function of the mean network connectivity. The biological implications of the growth model are also discussed.
Collapse
|
85
|
Chan AOO, Peng JZ, Lam SK, Lai KC, Yuen MF, Cheung HKL, Kwong YL, Rashid A, Chan CK, Wong BCY. Eradication of Helicobacter pylori infection reverses E-cadherin promoter hypermethylation. Gut 2006; 55:463-8. [PMID: 16428266 PMCID: PMC1856151 DOI: 10.1136/gut.2005.077776] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND E-cadherin methylation is important in gastric carcinogenesis. Reversing hypermethylation may halt the carcinogenic process. We have previously reported that Helicobacter pylori infection is associated with E-cadherin methylation in chronic gastritis patients. AIM To examine if eradication of H pylori could reverse E-cadherin methylation. METHODS Patients with dyspepsia and positive for H pylori infection, with a mucosal biopsy showing chronic active gastritis, were randomised to receive H pylori eradication therapy (group 1, n = 41) or no treatment (group 2, n = 40), and were followed up prospectively. Gastric mucosae were taken for methylation assay at week 0 (before treatment) and week 6 (after treatment). Archived specimens of intestinal metaplasia with H pylori infection (n = 22) and without (n = 19) were retrieved for methylation analysis. Methylation was assessed using methylation specific polymerase chain reaction and sequencing. RESULTS Methylation at E-cadherin was detected in 46% (19/41) and 17% (7/41) of patients at weeks 0 and 6, respectively, in group 1 (p = 0.004); 78.9% (15/19) of specimens were unmethylated after eradication of H pylori. Mucosal biopsy showed chronic inactive gastritis in 35 patients, intestinal metaplasia in one, and normal mucosa in five at week 6. Methylation was detected in 47.5% (19/40) and 52.5% (21/40) of patients at weeks 0 and 6, respectively, in group 2 (P = 0.5). Gastric mucosal biopsy showed persistent chronic active gastritis in all cases. Methylation frequency did not differ in H pylori positive or negative intestinal metaplastic specimens (72.7% v 63%; p = 0.5). CONCLUSION H pylori eradication therapy could reverse methylation in patients with chronic gastritis. This demonstrates an environmental effect on methylation.
Collapse
|
86
|
Tse TS, Lam KKH, Tsui KL, Chan CK, Leung GTC, Choi MC, Ko WC, Chan KK, Li SK. Feasibility of transradial coronary angiography and angioplasty in Chinese patients. Hong Kong Med J 2006; 12:108-14. [PMID: 16603777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
OBJECTIVE To assess the clinical applicability, efficacy, and safety of coronary angiography and angioplasty via a transradial approach in local Chinese patients. DESIGN Prospective case series. SETTING Regional hospital, Hong Kong. PATIENTS All patients undergoing coronary angiography and coronary angioplasty between 1 January and 30 June 2004. INTERVENTIONS Transradial coronary angiography and coronary angioplasty. MAIN OUTCOME MEASURES Feasibility, success rate, and complications. RESULTS A total of 268 coronary angiographies (62% of all coronary angiographies) and 118 coronary angioplasties (48% of all coronary angioplasties) were performed via a transradial approach. The procedural success rate for coronary angiography was 93.7% with a mean duration of 21.8 (standard deviation, 13.5) minutes compared with 17.9 (10.0) minutes for angiography via a femoral approach. Most (99%) patients were free from any complications. Of those patients who underwent elective transradial coronary angiography in the morning, 64% were discharged on the same day. Comparison of data in the first half of the study period with those in the second half revealed a significant increase in the percentage of coronary angiographies performed via a transradial approach (from 52% to 73%, P<0.0001), and an improved procedural success rate (from 91.5% to 95.3%, P=0.1). For transradial coronary angioplasty, the procedural success rate was 98%. A total of 246 lesions (2.08 lesions per patient) were treated with no procedure-related complications. CONCLUSIONS Transradial coronary angiography and angioplasty are feasible in a significant proportion of local Chinese patients and achieve a high success rate and low complication rate. It tends to prolong procedural duration, but improves patients' comfort and permits earlier ambulation and discharge. The procedural success rate improves with accumulating experience.
Collapse
|
87
|
Lee YY, Muchhal K, Chan CK, Cheung ASP. Levobupivacaine and fentanyl for spinal anaesthesia: a randomized trial. Eur J Anaesthesiol 2006; 22:899-903. [PMID: 16318658 DOI: 10.1017/s0265021505001523] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2005] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND OBJECTIVE Levobupivacaine 0.5% and racemic bupivacaine 0.5% are equally effective in spinal anaesthesia. Fentanyl has been used as an adjunct to racemic bupivacaine in spinal anaesthesia. At the time this study was designed, there was no published study on the intrathecal use of 0.5% levobupivacaine with fentanyl. METHODS This prospective, randomized, double-blind study compared the clinical efficacy, motor block and haemodynamic effects of using 2.6 mL of 0.5% levobupivacaine alone (25 patients) and 2.3 mL of 0.5% levobupivacaine with fentanyl 15 microg in 0.3 mL (25 patients) for spinal anaesthesia in urological surgery. The study solution was injected into the subarachnoid space at the L3-L4 interspace. RESULTS There were no significant differences between the two groups in the haemodynamic changes, and quality of sensory and motor block. Anaesthesia was adequate and patient satisfaction was good in all cases. Side-effects were minor and infrequent with both regimes. CONCLUSIONS We conclude that 2.3 mL of 0.5% levobupivacaine with fentanyl 15 microg is as effective as 2.6 mL of 0.5% levobupivacaine alone in spinal anaesthesia for urological surgery. Further studies may be directed to find the optimal combination of levobupivacaine and opioid with maximal haemodynamic stability and least motor block.
Collapse
|
88
|
Saw A, Chan CK, Penafort R, Sengupta S. A simple practical protocol for care of metal-skin interface of external fixation. THE MEDICAL JOURNAL OF MALAYSIA 2006; 61 Suppl A:62-5. [PMID: 17042233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Patients treated with external fixation for limb reconsturciton or fracture stabilization equire regular and prolongedperiod of pin-tract care involving frequent visits to clinic and dressing traditionally carried out by trained nurses or medical assistants. A simple method of do-it-yourself dressing was introduced in our institution and this study was undertaken to evaluate the effectiveness of the protocol. Sixty patients (40 trauma-related problems and 20 congenital or developmental disorders) were enrolled into the study. Following application of external fixation, the patients and/or their caretakers were taught on how to do pin-site dressing using normal saline or drinking water as cleansing solution on daily basis. Patients were discharged on the second or third post-operative day and were followed-up every two weeks for an average 182 days (range 66 to 379 days) with special attention on identifying pin-tract infection. A simple grading system for pin-tract infections was proposed. Of 40 patients with trauma-related problems. 65% were post-traumatic infections. There were 788 metal-skin interfaces (239 half-pin fixations and 549 tensioned wire fixations. A total 143 metal-skin interface infections (18.1%) involving half-pin sites (41.3%) and tensioned wire sites (58.7%) was noted. Majority were grade I infections (79.7%), 18.8% grade II and only 1.4% grade III. Most infections (81%)were caused by Staphylococcus aureus. Grade I infections were successfully treated with frequent dressing, grade II by adjunctive oral antibiotic but grade III infections required removal of fixator. All eventually healed. Do yourself non-sterile dressing of metal-skin interfaces is a cost-effective method of pin-site care with a low infection rate. The infections were sucessfully treated using guidelines according to the proposed classification of pin-tract infections.
Collapse
|
89
|
Wong WM, Gu Q, Chu KM, Yee YK, Fung FMY, Tong TSM, Chan AOO, Lai KC, Chan CK, Wong BCY. Lansoprazole, levofloxacin and amoxicillin triple therapy vs. quadruple therapy as second-line treatment of resistant Helicobacter pylori infection. Aliment Pharmacol Ther 2006; 23:421-7. [PMID: 16423001 DOI: 10.1111/j.1365-2036.2006.02764.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AIM To test the efficacy of levofloxacin-based second-line therapy for resistant Helicobacter pylori infection. METHODS One hundred and six patients who failed H. pylori eradication were randomized to receive (i) lansoprazole 30 mg, amoxicillin 1 g, levofloxacin 500 mg, all given twice daily for 7 days (LAL); or (ii) lansoprazole 30 mg twice daily, metronidazole 400 mg thrice daily, bismuth subcitrate 120 mg and tetracycline 500 mg four times daily for 7 days (quadruple). Post-treatment H. pylori status was determined by (13)C-urea breath test. RESULTS Intention-to-treat and per-protocol H. pylori eradication rates were 57/60% for the LAL group and 71/76% for the quadruple group respectively. Metronidazole, clarithromycin, amoxicillin and levofloxacin resistance were found in 76%, 71%, 0% and 18% of patients, respectively. Levofloxacin resistance led to treatment failure in the LAL group. For patients with dual resistance to metronidazole and clarithromycin, the eradication rates were 79% in the LAL group (levofloxacin-sensitive) and 65% in the quadruple group (P=0.34). CONCLUSION Lansoprazole, amoxicillin plus levofloxacin second-line therapy is comparable with quadruple therapy in efficacy. Subjects, especially those with dual resistance to metronidazole and clarithromycin, may consider levofloxacin-based therapy for levofloxacin-sensitive strains.
Collapse
|
90
|
Cheung RWW, Irwin MG, Law BCW, Chan CK. A Clinical Comparison of the Flexiblade™ and Macintosh Laryngoscopes for Laryngeal Exposure in Anesthetized Adults. Anesth Analg 2006; 102:626-30. [PMID: 16428574 DOI: 10.1213/01.ane.0000185035.89265.3c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The Flexiblade is a laryngoscope with a flexible blade. To evaluate the efficacy of the Flexiblade compared with the classic Macintosh laryngoscope, we performed a clinical study in 200 paralyzed patients undergoing elective surgery requiring general anesthesia and endotracheal intubation. Direct laryngoscopy was performed with a size 3 Macintosh laryngoscope and the Flexiblade, with and without activation of the lever. The laryngeal views were recorded, without manipulation, according to the Cormack and Lehane classification. No laryngoscopic view obtained by the Macintosh blade was worse than that obtained by the Flexiblade without the lever activated. The Macintosh blade improved 58.5% of non-Grade I views obtained by the Flexiblade with its lever not activated. However, when the Flexiblade lever was activated, 39.6% of non-Grade I views obtained by the Macintosh blade were improved, whereas 84.5% of non-Grade I views obtained by the inactivated Flexiblade were improved. Activating the Flexiblade lever never caused a deterioration of view. In only one case was the view better with the Macintosh blade than that with the activated Flexiblade. We conclude that the Flexiblade, after lever activation, is significantly better than the Macintosh laryngoscope for laryngeal visualization in paralyzed adults (P < 0.0001).
Collapse
|
91
|
Chan CK, Chan YC. Antidotes for tetramine poisoning. Hong Kong Med J 2006; 12:87. [PMID: 16495600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
|
92
|
Gu Q, Xia HHX, Wang JD, Wong WM, Chan AOO, Lai KC, Chan CK, Yuen MF, Fung FMY, Wong KW, Lam SK, Wong BCY. Update on clarithromycin resistance in Helicobacter pylori in Hong Kong and its effect on clarithromycin-based triple therapy. Digestion 2006; 73:101-6. [PMID: 16788304 DOI: 10.1159/000094040] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 03/18/2006] [Indexed: 02/05/2023]
Abstract
AIM To determine the antibiotic susceptibility of Helicobacter pylori and evaluate the efficacy of a clarithromycin-based triple therapy in relation to antibiotic resistance. METHODS Consecutive patients referred for upper endoscopy due to dyspeptic symptoms were recruited. Gastric biopsies were obtained for the CLO test, histology and culture. Antibiotic susceptibility was assessed by the E-test. Patients with H. pylori infection received rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days. RESULTS Of 234 patients recruited, 124 were H. pylori-positive and culture was successful in 102 patients. The updated prevalences of resistance to clarithromycin, amoxicillin and metronidazole were 7.8, 0 and 39.2%, respectively. A total of 86 patients received 1-week triple therapy with rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily, and 81 patients attended the follow-up test. Eradication rates by per-protocol and intention-to-treat analysis were 92.6 and 87.2%, respectively. The eradication rate by per protocol was significantly higher in patients with clarithromycin-susceptible strains than in those with clarithromycin-resistant strains (98.6 vs. 28.6%, p < 0.001). CONCLUSION Clarithromycin resistance reduces the clinical efficacy of clarithromycin-based triple therapy. However, due to the low prevalence of clarithromycin resistance, clarithromycin-based therapy is still the first choice for clinical use.
Collapse
|
93
|
Tal O, Rosenwaks Y, Preezant Y, Tessler N, Chan CK, Kahn A. Direct determination of the hole density of states in undoped and doped amorphous organic films with high lateral resolution. PHYSICAL REVIEW LETTERS 2005; 95:256405. [PMID: 16384485 DOI: 10.1103/physrevlett.95.256405] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2005] [Indexed: 05/05/2023]
Abstract
We investigate the density of states (DOS) for hole transport in undoped and doped amorphous organic films using high lateral resolution Kelvin probe force microscopy. Measurements are done on field effect transistors made of N,N1-diphenyl-N, N1-bis(1-naphthyl)-1,10-biphenyl-4,4II-diamine undoped or p doped with tetrafluoro-tetracyanoquinodimethane. We determine the DOS structure of the undoped material, including an anomalous peak related to interfaces between regions of different surface potential, the DOS doping-induced broadening, and doping-induced sharp peaks on the main DOS distribution.
Collapse
|
94
|
Hou M, Peng Z, Liu R, Lu K, Chan CK. Dynamics of a projectile penetrating in granular systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:062301. [PMID: 16485988 DOI: 10.1103/physreve.72.062301] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Indexed: 05/06/2023]
Abstract
The impact of a sphere with velocity u0 on a fine, loose granular system under the acceleration due to gravity has been studied by fast video photography. The behavior of the granular bed is found to be similar to a fluid during initial impact, followed by a cavity drag during projectile penetration. From the trajectory of the projectile it is found that the drag on the projectile can be well described by adding a bulk frictional force f to the hydrostatic force kappa(z) where kappa is a constant and z denotes the penetration depth. Both kappa and f are u0 dependent. This form of the drag force suggests that fluidlike viscous dissipations in the bed can be neglected in these three-dimensional (3D) experiments. However, due to the imposed boundary this hydrodynamic term of the drag force is found to be not negligible in quasi-2D granular beds.
Collapse
|
95
|
Arevalo JF, Rodriguez FJ, Rosales-Meneses JL, Dessouki A, Chan CK, Mittra RA, Ruiz-Moreno JM. Vitreoretinal surgery for macular hole after laser assisted in situ keratomileusis for the correction of myopia. Br J Ophthalmol 2005; 89:1423-6. [PMID: 16234445 PMCID: PMC1772920 DOI: 10.1136/bjo.2005.074542] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
UNLABELLED AMS: To describe the characteristics and surgical outcomes of full thickness macular hole surgery after laser assisted in situ keratomileusis (LASIK) for the correction of myopia. METHODS 13 patients (14 eyes) who developed a macular hole after bilateral LASIK for the correction of myopia participated in the study. RESULTS Macular hole formed 1-83 months after LASIK (mean 13 months). 11 out of 13 (84.6%) patients were female. Mean age was 45.5 years old (25-65). All eyes were myopic (range -0.50 to -19.75 dioptres (D); mean -8.4 D). Posterior vitreous detachment (PVD) was not present before and was documented after LASIK on 42.8% of eyes. Most macular hole were unilateral, stage 4 macular hole, had no yellow deposits on the retinal pigment epithelium, had no associated epiretinal membrane, were centric, and had subretinal fluid. The mean diameter of the hole was 385.3 microm (range 200--750 microm). A vitrectomy closed the macular hole on all eyes with an improvement on final best corrected visual acuity (VA) on 13 out of 14 (92.8%) patients. CONCLUSIONS This study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with a macular hole after LASIK.
Collapse
|
96
|
Lee YY, Ngan Kee WD, Muchhal K, Chan CK. Randomized double-blind comparison of ropivacaine-fentanyl and bupivacaine-fentanyl for spinal anaesthesia for urological surgery. Acta Anaesthesiol Scand 2005; 49:1477-82. [PMID: 16223393 DOI: 10.1111/j.1399-6576.2005.00864.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Early studies have suggested that ropivacaine causes less motor block than bupivacaine, which might be advantageous in spinal anaesthesia for short procedures. The aim of this study was to compare plain ropivacaine 10 mg and plain bupivacaine 10 mg, both with fentanyl 15 microg, for spinal anaesthesia in urological surgery. METHODS This was a prospective randomized double-blind study. After written informed consent had been obtained, 34 ASA I-III patients scheduled for urological surgery were randomly assigned to receive intrathecal injection of either plain ropivacaine 10 mg with fentanyl 15 microg (ropivacaine group) or plain bupivacaine 10 mg with fentanyl 15 microg (bupivacaine group) using a combined spinal-epidural technique. RESULTS All patients achieved sensory block to the T10 dermatome or higher at 15 min after intrathecal injection. One patient in the ropivacaine group was excluded because of unexpectedly prolonged surgery. The primary outcome, the duration of motor block, was shorter in the ropivacaine group (median, 126 min; interquartile range, 93-162 min) compared with the bupivacaine group (median, 189 min; interquartile range, 157-234 min; difference between medians, 71 min; 95% confidence interval, 28-109 min; P = 0.003). The duration of complete motor block was also shorter in the ropivacaine group compared with the bupivacaine group. There was no difference in the onset time of motor block. The characteristics of sensory block and the haemodynamic changes were similar between the groups. CONCLUSION Plain ropivacaine 10 mg plus fentanyl 15 microg provided similar sensory anaesthesia, but with a shorter duration of motor block, compared with plain bupivacaine 10 mg plus fentanyl 15 microg when used for spinal anaesthesia in urological surgery.
Collapse
|
97
|
Chan AOO, Lam KF, Hui WM, Hu WH, Li J, Lai KC, Chan CK, Yuen MF, Lam SK, Wong BCY. Validated questionnaire on diagnosis and symptom severity for functional constipation in the Chinese population. Aliment Pharmacol Ther 2005; 22:483-8. [PMID: 16128687 DOI: 10.1111/j.1365-2036.2005.02621.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Functional constipation is a common problem in clinical practice. No validated questionnaire is available in Chinese. AIM To develop a validated questionnaire for diagnosis and symptom assessment in functional constipation for the Chinese population. METHODS One hundred and eleven patients with constipation and 110 healthy controls were presented with a 24-item constipation questionnaire in the Chinese language. Quality of life in constipation patients was assessed by Short Form-36. Polyethylene glycol was prescribed, for 4 weeks, to 20 patients with newly diagnosed constipation. The questionnaire was administered before and 4 weeks after treatment. Concept, content, construct, discriminant validity and reliability of the questionnaire were assessed. RESULTS Six items were selected by logistic regression to account for most of the differences between controls and constipated patients with a good reproducibility and internal consistency. A cut-off score of > or =5 was determined to discriminate between controls and constipated patients with a sensitivity of 91% and a specificity of 91%. The constipation questionnaire correlated negatively with seven domains of the Short Form-36 and discriminated between constipated patients who reported symptomatic improvement during polyethylene glycol treatment. CONCLUSIONS The Chinese constipation questionnaire could be used in epidemiological studies to assess the frequency and severity of constipation in patient populations and in interventional studies of constipation.
Collapse
|
98
|
Xia B, Xia HHX, Ma CW, Wong KW, Fung FMY, Hui CK, Chan CK, Chan AOO, Lai KC, Yuen MF, Wong BCY. Trends in the prevalence of peptic ulcer disease and Helicobacter pylori infection in family physician-referred uninvestigated dyspeptic patients in Hong Kong. Aliment Pharmacol Ther 2005; 22:243-9. [PMID: 16091062 DOI: 10.1111/j.1365-2036.2005.02554.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Peptic ulcer disease is mainly caused by Helicobacter pylori infection and the use of non-steroidal anti-inflammatory drugs. AIM To investigate the trends in the prevalence of peptic ulcer disease, H. pylori infection and non-steroidal anti-inflammatory drug use in uninvestigated dyspeptic patients over recent years in Hong Kong. METHODS Data from consecutive patients with uninvestigated dyspeptic symptoms referred by family physicians for open access upper endoscopy during 1997 and 2003 were analysed in relation to peptic ulcer disease, H. pylori infection and non-steroidal anti-inflammatory drug use. RESULTS Among 2700 patients included, 405 (15%) had peptic ulcer disease and 14 (0.5%) had gastric cancer. There was a reduced trend from 1997 to 2003 in the prevalence of peptic ulcer disease (17, 20, 14, 16, 13, 14 and 14%, respectively, chi2 = 5.80, P = 0.016) (mainly because of decrease in duodenal ulcers), H. pylori infection (44, 50, 49, 44, 40, 40, 36 and 43%, respectively, chi2 = 13.55, P < 0.001) and non-steroidal anti-inflammatory drug use (13, 5, 5, 6, 3, 4, 4 and 5% respectively, chi2 = 13.61, P < 0.001). The prevalence of peptic ulcer disease, H. pylori infection and non-steroidal anti-inflammatory drug use between 2001 and 2003 were significantly lower than that between 1997 and 2000 (17% vs. 13%, OR = 0.78, 95% CI: 0.63-0.96, P = 0.020 for peptic ulcer disease; 47% vs. 39%, OR =0.72, 95% CI: 0.60-0.86, P < 0.001 for H. pylori infection; and 6% vs. 4%, OR = 0.56, 95% CI: 0.39-0.82, P = 0.002 for non-steroidal anti-inflammatory drug use). H. pylori infection was associated with both duodenal ulcer (OR = 15.87, 95% CI: 10.60-23.76, P < 0.001) and gastric ulcer (OR = 3.12, 95% CI: 2.15-4.53, P < 0.001) whereas non-steroidal anti-inflammatory drug use was only associated with gastric ulcer (OR = 2.97, 95% CI: 1.70-5.20, P < 0.001). CONCLUSIONS The prevalence of peptic ulcer disease, mainly duodenal ulcers, was reduced in association with a decreasing trend in the prevalence of H. pylori infection and non-steroidal anti-inflammatory drug use from 1997 to 2003.
Collapse
|
99
|
Cheng CW, Chan PS, Chan LW, Chan CK, Ng CF, Lai MM. 17-year follow-up of a randomized prospective controlled trial of adjuvant intravesical doxorubicin in the treatment of superficial bladder cancer. Int Braz J Urol 2005; 31:204-11. [PMID: 15992422 DOI: 10.1590/s1677-55382005000300003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Accepted: 04/25/2005] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To evaluate the efficacy of adjuvant intravesical doxorubicin in superficial transitional cell carcinoma of the urinary bladder on long-term follow-up. MATERIALS AND METHODS Between July 1986 and November 1991, all patients harboring superficial bladder cancers (Ta or T1) with one or more of these criteria (stage>a, grade>1, size>1 cm, multiple or recurrent tumors) were randomized to receive either 50 mg doxorubicin or no adjuvant therapy. Patients with recurrences were allowed to receive doxorubicin or other intravesical agents. Recurrence, progression and survival were analyzed. RESULTS There were 82 patients included (64 males and 18 females). The mean age was 64 years. Forty-six patients were randomized to the doxorubicin group and 36 to the control group. Final analysis was made at median follow-up of 45, 128 and 131.5 months for recurrence, progression and survival, respectively. Recurrence free, progression free and disease specific survival did not differ significantly between groups. The 10-year Kaplan-Meier estimates for recurrence free, progression free and disease specific survival were 67%, 84% and 92%, respectively for the doxorubicin group, and were 50%, 89% and 97%, respectively for the control group. Tumor size predicted recurrence (p=0.013) and grade predicted progression (p=0.004) with multivariate analysis. CONCLUSIONS Adjuvant intravesical doxorubicin could not be shown to improve recurrence, progression and survival of superficial bladder cancer, compared with control on long-term follow-up. Tumor size and grade were shown to be prognostic factors for recurrence and progression, respectively.
Collapse
|
100
|
Leung CC, Chan CK, Tam CM, Yew WW, Kam KM, Au KF, Tai LB, Leung SM, Ng J. Chest radiograph screening for tuberculosis in a Hong Kong prison. Int J Tuberc Lung Dis 2005; 9:627-32. [PMID: 15971389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
SETTING Long-stay prisoners are not regularly screened for TB in Hong Kong. OBJECTIVE To evaluate tuberculosis (TB) screening in prison. METHOD All prisoners in a maximum security prison as of 31 October 2001 were screened by chest radiograph (CXR), except for those being followed up for TB or examined by CXR in the last 6 months. RESULTS A total of 814 male prisoners aged 34.6 +/- 9.6 (mean +/- SD) years were successfully screened. Of 53 cases (6.51%) with radiographic abnormalities, 10 active TB cases (8 culture-negative, 2 culture-positive) were diagnosed, giving an overall yield of 1.23% (95%CI 0.59-2.26). There was no statistical difference in age, ethnicity, place of birth or residency status between those with and those without TB (all P > 0.05). Incarceration > or = 2 years, being in current prison > or = 2 years and not having CXR in last 2 years were associated with TB in univariate analysis (all P < 0.05), but only the last remained an independent predictor in multiple logistic regression (OR 16.8, 95%CI 2.1-132.9, P = 0.008). In that group, the yield was 3.1% (95%CI 1.42-5.89). No further cases were detected in the subsequent 2 years. CONCLUSION CXR screening of long-stay prisoners gave a high yield in this study.
Collapse
|