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S Y Ho

Publications and source records attributed to S Y Ho.

At least 37 records · Page 2Linked to original sources
PubMed2002

Smoking and mortality in 81,344 drivers in Guangzhou, China.

OBJECTIVES: Previous studies on drivers focused on the effect of their exposure to vehicle exhaust and there is little evidence of the effect of smoking. This cohort analytical study aimed to examine the mortality of drivers relative to smoking and professional driving in Guangzhou, China. METHODS: Information on demographic characteristics, type of driver (professional and non-professional), smoking, and drinking were retrieved from medical records of drivers who applied for driving licences from March to December 1992. Vital status and causes of death of 81,344 men aged 30 or above were ascertained to the end of September 1999 (follow up, mean=7.14 years, median=7.17 years). RESULTS: At baseline, the mean (SD) age was 40.8 (5.6) years. One third were professional drivers; 49.0% were daily smokers. 858 Deaths were identified. The relative risk of overall mortality for ever smoking was 1.24 (95% confidence interval (95% CI) 1.07 to 1.44) after adjusting for age, alcohol drinking, education, and type of drivers. Compared with non-professional drivers, professional drivers had similar risks of death, and their relative risk of overall mortality for ever smoking was 1.35 (1.06 to 1.71). CONCLUSIONS: Smoking is a more important cause of death than professional driving itself. The results show serious public health problems in the early stage of the tobacco epidemic and support urgent measures to help drivers stop smoking.

Adult↗
PubMed2002

Public opinion on smoke-free policies in restaurants and predicted effect on patronage in Hong Kong.

BACKGROUND: The Hong Kong government has proposed legislation for smoke-free policies in all restaurants and bars. This is opposed by certain sections of the catering industry. OBJECTIVE: To assess public opinion on smoke-free restaurants and to estimate changes in patronage. DESIGN: A population based, cross sectional random digit dialling telephone survey conducted from November 1999 to January 2000. SETTING AND PARTICIPANTS: 1077 randomly selected subjects age 15 years or over (response fraction of 81.6%). RESULTS: 68.9% (95% confidence interval (CI) 66.2% to 71.7%) supported a totally smoke-free policy in restaurants. Experiences of discomfort or symptoms from second hand smoke in restaurants were common. The majority (77.2%, 95% CI 74.7% to 79.7%) anticipated no change in their frequency of use of restaurants after a smoke-free policy. Increased use was predicted by 19.7% (95% CI 17.3% to 22.1%) of respondents, whereas 3.2% (95% CI 2.2% to 4.4%) stated that they would dine out less often. In multivariate analyses, non-smokers (adjusted odds ratio (OR) 4.9), people who ate three times or less per week in restaurants as compared to those who ate >10 times per week (OR 2.1), those who had previous experience of discomfort from exposure to passive smoking in restaurants (OR 2.8), or who had avoided restaurants in the past because of smoking (OR 1.9), were more likely to support a totally smoke-free policy in restaurants. Smoke-free policies do not appear to have an adverse effect on restaurants, and may increase business by a considerable margin. CONCLUSION: This comprehensive survey-the first in Asia-shows strong community support for smoke-free dining and predicts an overall increase in the patronage of restaurants after the introduction of legislation for totally smoke-free restaurants.

Adolescent↗
PubMed2002

Subcutaneous steroid injection as treatment for chalazion: prospective case series.

OBJECTIVE: To study the efficacy of subcutaneous steroid injection in the treatment of chalazion. DESIGN: Prospective consecutive case series. SETTING: University teaching hospital, Hong Kong. PATIENTS: Patients with chalazion presenting to the out-patient clinic of the Department of Ophthalmology at the Prince of Wales Hospital from January to June 1998. MAIN OUTCOME MEASURES: Size of the chalazion after steroid injection treatment. RESULTS: Forty-eight consecutive patients with chalazion were treated with injection of triamcinolone into the subcutaneous tissue around the lesion. In 43 (89.6%) patients, the lesion subsided completely. Twenty-six (54.2%) patients had lesions that subsided with one injection. The size and duration of the chalazion at presentation did not significantly affect the outcome of the treatment. Two patients developed depigmentation of the skin at the site of injection. No other major complications were encountered. CONCLUSION: Subcutaneous injection of the steroid triamcinolone acetonide appears to be a simple and effective treatment for chalazion. Further comparative clinical trials are indicated.

Adolescent↗
PubMed2001

Mortality and smoking in Hong Kong: case-control study of all adult deaths in 1998.

OBJECTIVE: To assess the mortality currently associated with smoking in Hong Kong, and, since cigarette consumption reached its peak 20 years earlier in Hong Kong than in mainland China, to predict mortality in China 20 years hence. DESIGN: Case-control study. Past smoking habits of all Chinese adults in Hong Kong who died in 1998 (cases) were sought from those registering the death. SETTING: All the death registries in Hong Kong. PARTICIPANTS: 27 507 dead cases (81% of all registered deaths) and 13 054 live controls aged >/=35 years. MAIN OUTCOME MEASURES: Mortality from all causes and from specific causes. RESULTS: In men aged 35-69 the adjusted risk ratios (and 95% confidence intervals) comparing smokers with non-smokers were 1.92 (1.70 to 2.16) for all deaths, 2.22 (1.94 to 2.55) for neoplastic deaths, 2.60 (2.10 to 3.21) for respiratory deaths (including tuberculosis, risk ratio 2.54), and 1.68 (1.43 to 1.97) for vascular deaths (each P<0.0001). In women aged 35-69 the corresponding risk ratios were 1.62 (1.40 to 1.88) for all deaths, 1.60 (1.33 to 1.93) for neoplastic deaths, 3.13 (2.21 to 4.44) for respiratory deaths, and 1.55 (1.20 to 1.99) for vascular deaths (each P<0.001). If these associations with smoking are largely or wholly causal then, among all registered deaths at ages 35-69 in 1998, tobacco caused about 33% (2534/7588) of all male deaths and 5% (169/3341) of all female deaths (hence 25% of all deaths at these ages). At older ages tobacco seemed to be the cause of 15% (3017/20 420) of all deaths. CONCLUSIONS: Among middle aged men the proportion of deaths caused by smoking is more than twice as big in Hong Kong now (33%) as in mainland China 10 years earlier. This supports predictions of a large increase in tobacco attributable mortality in China as a whole.

Adult↗
PubMed2001

Anatomic-electrophysiological correlations concerning the pathways for atrioventricular conduction.

The remarkable success of radiofrequency ablation in recent decades in curing atrioventricular nodal reentrant tachycardias has intensified efforts to provide a solid theoretical basis for understanding the mechanisms of atrioventricular transmission. These efforts, which were made by both anatomists and electrophysiologists, frequently resulted in seemingly controversial observations. Quantitatively and qualitatively, our understanding of the mysteries of propagation through the inhomogeneous and extremely complex atrioventricular conduction axis is much deeper than it was at the beginning of the past century. We must go back to the initial sources, nonetheless, in an attempt to provide a common ground for evaluating the morphological and electrophysiological principles of junctional arrhythmias. In this review, we provide an account of the initial descriptions, which still provide an appropriate foundation for interpreting recent electrophysiological findings.

Atrioventricular Node↗
PubMed2001

Genetic analysis of digestive physiology using fluorescent phospholipid reporters.

Zebrafish are a valuable model for mammalian lipid metabolism; larvae process lipids similarly through the intestine and hepatobiliary system and respond to drugs that block cholesterol synthesis in humans. After ingestion of fluorescently quenched phospholipids, endogenous lipase activity and rapid transport of cleavage products results in intense gall bladder fluorescence. Genetic screening identifies zebrafish mutants, such as fat free, that show normal digestive organ morphology but severely reduced phospholipid and cholesterol processing. Thus, fluorescent lipids provide a sensitive readout of lipid metabolism and are a powerful tool for identifying genes that mediate vertebrate digestive physiology.

Animals↗
PubMed2001

Effect of intracameral acetylcholine on latanoprost in preventing ocular hypertension after phacoemulsification and intraocular lens implantation.

PURPOSE: To evaluate the effect of intracameral acetylcholine on latanoprost in preventing ocular hypertension in the early period after phacoemulsification with posterior chamber intraocular lens (PC IOL) implantation. SETTING: Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Shatin, Hong Kong, China. METHODS: Patients with uncomplicated cataract having phacoemulsification with PC IOL implantation were included in this prospective randomized double-masked clinical trial. The eyes were randomly assigned to 1 of 4 groups based on postoperative application of latanoprost 0.005% alone (Group 1), latanoprost 0.005% with intracameral acetylcholine (Group 2), intracameral acetylcholine alone (Group 3), and no medication (controls (Group 4). Intraocular pressure (IOP) was measured 3 and 24 hours postoperatively. The anterior chamber was examined for the level of cells and flare using slitlamp biomicroscopy. RESULTS: Three and 24 hours after surgery, the decrease in mean IOP in eyes receiving latanoprost alone was not statistically significantly different from that in control eyes (P >.05). Eyes receiving intracameral acetylcholine alone had a significant decrease in the mean IOP at 3 hours (P <.05) but not at 24 hours compared to control eyes (P >.05). There were no significant differences in the mean postoperative IOP decrease between eyes receiving latanoprost with intracameral acetylcholine and those receiving intracameral acetylcholine alone (P >.05). CONCLUSIONS: A single application of latanoprost did not significantly lower IOP in the first 24 hours after phacoemulsification with PC IOL implantation. Eyes receiving intracameral acetylcholine alone had a significantly greater decrease in IOP than control eyes at 3 hours but not at 24 hours. The addition of intracameral acetylcholine to latanoprost did not enhance or reduce latanoprost's IOP-lowering effect.

Acetylcholine↗
PubMed2001

Preoperative latanoprost to prevent ocular hypertension after phacoemulsification and intraocular lens implantation.

PURPOSE: To evaluate the efficacy of latanoprost given 2 hours preoperatively to prevent ocular hypertension in the early period after phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation. SETTING: Departments of Ophthalmology, United Christian Hospital and Prince of Wales Hospital, Hong Kong, China. METHODS: Sixty-four eyes of 64 patients with uncomplicated cataract having phacoemulsification with PC IOL implantation were included in this prospective randomized double-masked clinical trial. The eyes were randomly assigned to 1 of 2 groups: application of latanoprost 0.005% 2 hours before surgery or no latanoprost (control). Intraocular pressure (IOP) was measured 3 and 24 hours postoperatively. The anterior chamber was examined for the level of cells and flare using a slitlamp biomicroscope. The level of significance was 5%. RESULTS: The decrease in the mean IOP was not statistically significantly different between eyes receiving latanoprost 2 hours preoperatively and control eyes 3 hours (P =.843) and 24 hours (P =.721) postoperatively. CONCLUSION: A single application of latanoprost given 2 hours before phacoemulsification and PC IOL implantation did not produce a statistically significant IOP-lowering effect when compared with a control group in the first 24 hours after surgery.

Aged↗
PubMed2001

Congenital supravalvar aortic stenosis: a simple lesion?

The underlying cause of congenital supravalvular aortic stenosis (SVAS) has recently been identified as a loss-of function mutation of the elastin gene on chromosome 7q11.23, resulting in an obstructive arteriopathy of varying severity, which is most prominent at the aortic sinutubular junction. The generalized nature of the disease explains the frequent association with stenoses of systemic and pulmonary arteries. Furthermore, localization of the supravalvular stenosis at the level of the commissures of the aortic valve has important implications for both aortic valve function and coronary circulation. This review summarizes the recent advances with regard to the pathogenesis of SVAS and describes the multitude of clinically relevant pathologic features other that the mere 'supra-aortic' narrowing that have important implications for surgical therapy.

Aorta↗
PubMed2001

Topographic anatomy of the inferior pyramidal space: relevance to radiofrequency catheter ablation.

INTRODUCTION: Radiofrequency catheter ablation carried out in the vicinity of the triangle of Koch risks damaging not only the AV conduction tissues but also their arterial supply. The aim of this study was to examine the relationship of the AV nodal artery to the inferior pyramidal space, the triangle of Koch, and the right atrial endocardial surface. METHODS AND RESULTS: We studied 41 heart specimens, 24 by gross dissections and 17 by histologic sections. The proximity of the AV nodal artery to the surface landmarks of the triangle of Koch was variable, but it was notable that in 75% of specimens the artery passed close to the endocardial surface of the right atrium and within 0.5 to 5 mm of the mouth of the coronary sinus. In all specimens, the mean distance of the artery to the endocardial surface was 3.5 +/- 1.5 mm at the base of Koch's triangle. The location of the compact AV node and its inferior extensions varied within the landmarks of the triangle. At the mid-level of Koch's triangle, the compact node was medially situated in 82% of specimens, but it was closer to the hinge of the tricuspid valve in the remaining 18% of specimens. In 12% of specimens, the inferior parts of the node extended to the level of the mouth of the coronary sinus. CONCLUSION: The nodal artery runs close to the orifice of the coronary sinus, the endocardial surface of the right atrium, the middle cardiac vein, and the specialized conduction tissues in most hearts. The nodal artery and/or the AV conduction tissues can be at risk of damage when ablative procedures are carried out at the base of the triangle of Koch.

Adolescent↗
PubMed2001

The anatomy of the septal perforating arteries in normal and congenitally malformed hearts.

BACKGROUND: Many cardiac operations involve incisions and sutures on or near the ventricular septum. These jeopardize the septal perforating arteries. Our aim was to provide guidelines for the surgeon to predict the site of these vessels. METHODS AND RESULTS: We dissected 50 hearts. In 16 of these we also conducted histologic examination of the area of the septum containing the atrioventricular node, the penetrating bundle (of His), and the branching atrioventricular bundle to elucidate the source of the vascular supply to these structures. The major perforating septal arteries arise from the superior interventricular artery or, in hearts with a rudimentary right ventricle, from the superior delimiting artery. The first is usually the largest. The location of this artery can be predicted relative to the position of the medial papillary muscle. In abnormal hearts, holes within the ventricular septum in the presence of a well-developed muscular outlet septum were found to deviate the path of the septal perforating arteries in a predictable manner. The triangular area bordered by the margin of the ventricular septal defect, the muscular outlet septum, and the medial papillary muscle is free of major perforating arteries. The histologic studies showed that the conduction tissues at the base of the ventricles tend to receive their blood supply from arteries arising from the inferior interventricular artery, except in double-inlet left ventricle, in which the arterial supply is from the right-sided delimiting artery. CONCLUSION: The location of the first superior septal perforating artery is predictable in many cases. Its course leaves a triangular area on the muscular ventricular septum that is free of major arteries.

Cadaver↗
PubMed2001

Properties of multiple intersection-union tests for multiple endpoints in combination therapy trials.

We consider intersection-union tests involving multiple endpoints in a combination drug trial, for which we control the familywise error rate in the strong sense using closed testing methods. Bonferroni-Holm, Simes-Hommel, and Resampling-Based methods all are considered in this context. Familywise error rate control heuristics are developed and evaluated using a simulation study that is specifically tailored to the intersection-union setting. Both Resampling-Based and Simes-Hommel uniformly outperform the Bonferroni-Holm. Using simulations of power, the choice of Simes-Hommel versus Resampling-Based is seen to depend on the particular alternative of interest. Because it is simpler and has generally good power, we recommend the Simes-Hommel intersection-union tests. The techniques are illustrated using real data from a clinical trial to evaluate a combination asthma therapy.

Algorithms↗
PubMed2001

Technical innovation to calibrate the gantry angle indicators of linear accelerators.

Finding the actual zero degree of the gantry angle is important in order to perform the mechanical quality assurance (QA) of linear accelerators. To determine real zero, we must locate a "good surface" which could be defined as a plane on the surface of the gantry head that is perpendicular to the direction of radiation. The actual gantry angle could then be defined as the angle between vertical, as indicated by a plumb bob, and the direction of the beam axis that could be indicated by the position of a BB placed in the central axis and its shadow. From this we located the real zero degree and the good surface. The good surface can be applied to check the important mechanical readouts. The technique we introduce could solve the essential problems of a traditional QA technique, as well as taking up an important role in the quality assurance of a patient's treatment.

Calibration↗
PubMed2001

Architecture of the pulmonary veins: relevance to radiofrequency ablation.

BACKGROUND: Radiofrequency ablation of tissues in pulmonary veins can eliminate paroxysmal atrial fibrillation. OBJECTIVE: To explore the characteristics of normal pulmonary veins so as to provide more information relevant to radiofrequency ablation. METHODS: 20 structurally normal heart specimens were examined grossly. Histological sections were made from 65 pulmonary veins. RESULTS: The longest myocardial sleeves were found in the superior veins. The sleeves were thickest at the venoatrial junction in the left superior pulmonary veins. For the superior veins, the sleeves were thickest along the inferior walls and thinnest superiorly. The sleeves were composed mainly of circularly or spirally oriented bundles of myocytes with additional bundles that were longitudinally or obliquely oriented, sometimes forming mesh-like arrangements. Fibrotic changes estimated at between 5% and 70% across three transverse sections were seen in 17 veins that were from individuals aged 30 to 72 years. CONCLUSIONS: The myocardial architecture in normal pulmonary veins is highly variable. The complex arrangement, stretch, and increase in fibrosis may produce greater non-uniform anisotropic properties.

Adult↗
PubMed2001

Common mechanisms of monoacylglycerol and fatty acid uptake by human intestinal Caco-2 cells.

Free fatty acids (FFA) and sn-2-monoacylglycerol (sn-2-MG), the two hydrolysis products of dietary triacylglycerol, are absorbed from the lumen into polarized enterocytes that line the small intestine. Intensive studies regarding FFA transport across the brush-border membrane of the enterocyte are available; however, little is known about sn-2-MG transport. We therefore studied the kinetics of sn-2-MG transport, compared with those of long-chain FFA (LCFA), by human intestinal Caco-2 cells. To mimic postprandial luminal and plasma environments, we examined the uptake of taurocholate-mixed lipids and albumin-bound lipids at the apical (AP) and basolateral (BL) surfaces of Caco-2 cells, respectively. The results demonstrate that the uptake of sn-2-monoolein at both the AP and BL membranes appears to be a saturable function of the monomer concentration of sn-2-monoolein. Furthermore, trypsin preincubation inhibits sn-2-monoolein uptake at both AP and BL poles of cells. These results suggest that sn-2-monoolein uptake may be a protein-mediated process. Competition studies also support a protein-mediated mechanism and indicate that LCFA and LCMG may compete through the same membrane protein(s) at the AP surface of Caco-2 cells. The plasma membrane fatty acid-binding protein (FABP(pm)) is known to be expressed in Caco-2, and here we demonstrate that fatty acid transport protein (FATP) is also expressed. These putative plasma membrane LCFA transporters may be involved in the uptake of sn-2-monoolein into Caco-2 cells.

Biological Transport↗