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Griffiths M, Ooi MH, Wong SC, Mohan A, Podin Y, Perera D, Chieng CH, Tio PH, Cardosa MJ, Solomon T. 1648 Raised levels of interleukin 1β, interleukin 1 receptor antagonist and G-CSF predict fatality among encephalitis patients infected with enterovirus 71. Journal of Neurology, Neurosurgery and Psychiatry 2012. [DOI: 10.1136/jnnp-2011-301993.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Zhang P, Jian XX, Wong SC, Choi K. Potential field cellular automata model for pedestrian flow. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:021119. [PMID: 22463165 DOI: 10.1103/physreve.85.021119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Indexed: 05/31/2023]
Abstract
This paper proposes a cellular automata model of pedestrian flow that defines a cost potential field, which takes into account the costs of travel time and discomfort, for a pedestrian to move to an empty neighboring cell. The formulation is based on a reconstruction of the density distribution and the underlying physics, including the rule for resolving conflicts, which is comparable to that in the floor field cellular automaton model. However, we assume that each pedestrian is familiar with the surroundings, thereby minimizing his or her instantaneous cost. This, in turn, helps reduce the randomness in selecting a target cell, which improves the existing cellular automata modelings, together with the computational efficiency. In the presence of two pedestrian groups, which are distinguished by their destinations, the cost distribution for each group is magnified due to the strong interaction between the two groups. As a typical phenomenon, the formation of lanes in the counter flow is reproduced.
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Abstract
Stem Cells: A Personal Perspective
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Ling ML, Oh H, Lee SL, Wong SC, Lang L. Growing and equipping the infection control community in Singapore. BMC Proc 2011. [PMCID: PMC3239772 DOI: 10.1186/1753-6561-5-s6-p4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Mason A, Wong SC, McGrogan P, Ahmed SF. Effect of testosterone therapy for delayed growth and puberty in boys with inflammatory bowel disease. Horm Res Paediatr 2011; 75:8-13. [PMID: 20664179 DOI: 10.1159/000315902] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 05/20/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND pubertal delay and growth retardation are common in children with inflammatory bowel disease (IBD). AIMS To assess pubertal status and growth in a group of boys with IBD undergoing testosterone therapy for pubertal induction. METHODS retrospective study of height, weight and pubertal status in 8 boys with IBD before and after testosterone therapy. Height velocity (HV) over the 6 months before each assessment was converted to standard deviation score. Markers of disease activity and concomitant medication were recorded. Response was based on an advance in pubertal status and a greater than 50% increase in HV. RESULTS eight boys with IBD, median age 14.8 years, had pubertal induction using either monthly injections of 50 mg Sustanon or daily 2.5/5 mg Andropatch. Seven boys showed an advance of pubertal status. Six boys had a greater than 50% increase in HV; median HV at T0 was 1.6 cm/year (0, 5) compared with 6.9 cm/year (1, 11.7) at T6 (p = 0.005). C-reactive protein during testosterone therapy had a significant association with HV at T6 (r = -0.786; p = 0.021). CONCLUSION in most cases, testosterone therapy in boys with IBD and delayed growth and puberty is associated with an advance in pubertal status and an improvement in growth.
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Pei X, Wong SC, Sze NN. A joint-probability approach to crash prediction models. ACCIDENT; ANALYSIS AND PREVENTION 2011; 43:1160-1166. [PMID: 21376914 DOI: 10.1016/j.aap.2010.12.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 12/18/2010] [Accepted: 12/22/2010] [Indexed: 05/30/2023]
Abstract
Many road safety researchers have used crash prediction models, such as Poisson and negative binomial regression models, to investigate the associations between crash occurrence and explanatory factors. Typically, they have attempted to separately model the crash frequencies of different severity levels. However, this method may suffer from serious correlations between the model estimates among different levels of crash severity. Despite efforts to improve the statistical fit of crash prediction models by modifying the data structure and model estimation method, little work has addressed the appropriate interpretation of the effects of explanatory factors on crash occurrence among different levels of crash severity. In this paper, a joint probability model is developed to integrate the predictions of both crash occurrence and crash severity into a single framework. For instance, the Markov chain Monte Carlo (MCMC) approach full Bayesian method is applied to estimate the effects of explanatory factors. As an illustration of the appropriateness of the proposed joint probability model, a case study is conducted on crash risk at signalized intersections in Hong Kong. The results of the case study indicate that the proposed model demonstrates a good statistical fit and provides an appropriate analysis of the influences of explanatory factors.
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Allsop RE, Sze NN, Wong SC. An update on the association between setting quantified road safety targets and road fatality reduction. ACCIDENT; ANALYSIS AND PREVENTION 2011; 43:1279-1283. [PMID: 21376927 DOI: 10.1016/j.aap.2011.01.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 01/16/2011] [Indexed: 05/30/2023]
Abstract
This note is intended to rectify estimates provided in a previous paper (Wong et al., 2006) of the short-term effectiveness in terms of road fatality reduction of the setting of quantified road safety targets using data from 14 OECD countries during the period 1980-1999. This work is important in measuring the association between target setting and road safety improvement, because such targets are intended to serve as a useful tool to motivate timely road safety measures by the road authorities and others. The estimates to be rectified were based on before-and-after analysis using a comparison group of countries for each country that had set a target. This note first provides a correction to the qualification test for the inclusion of a country in any particular comparison group. It then presents the numerical effects of this correction on the estimates of the effectiveness of setting quantified road safety targets, both in individual countries and across the whole group of countries that set targets in the relevant period. Finally, impacts on the findings of the previous paper are discussed, with the conclusion that the changes in those of the numerical estimates that are affected do not alter the main message of the paper.
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Wong SC, Kumar P, Galloway PJ, Blair JC, Didi M, Dalzell AM, Hassan K, McGrogan P, Ahmed SF. A preliminary trial of the effect of recombinant human growth hormone on short-term linear growth and glucose homeostasis in children with Crohn's disease. Clin Endocrinol (Oxf) 2011; 74:599-607. [PMID: 21470283 DOI: 10.1111/j.1365-2265.2011.03977.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND It is unclear whether recombinant human growth hormone (rhGH) improves linear growth in children with Crohn's disease (CD). AIMS To investigate the effects of rhGH on height velocity (HV) and glucose homeostasis over a 6-month period. DESIGN AND SETTING Randomized controlled trial in two tertiary children's hospitals in 22 children with inflammatory bowel disease amongst whom 21 had CD. Duration of disease from diagnosis and number of acute relapses requiring either exclusive enteral nutrition or therapeutic dose of oral prednisolone were similar in the treatment and control groups. INTERVENTION Either rhGH (0·067 mg/kg per day) as daily subcutaneous injections (rhGH group; n, 11) or no rhGH, (Ctrl; n, 11) for 6 months. MAIN OUTCOME MEASURE Percentage change in HV after 6 months in the two groups. Auxology, puberty, skeletal age, disease factors, treatment and glucose homeostasis were also assessed. RESULTS Median HV increased from 4·5 (range, 0·6, 8·9) at baseline to 10·8 (6·1, 15·0) cm/year at 6 month (P = 0·003) in the rhGH group, whereas in the Ctrl group, it was 3·8 (1·4, 6·7) and 3·5 cm/year (2·0, 9·6), respectively (P = 0·58). Median percentage increase in HV after 6 months in the rhGH group was 140% (16·7, 916·7) compared with 17·4% (-42·1%, 97·7%) in the Ctrl group (P < 0·001). There were no significant differences in disease activity and proinflammatory cytokines at baseline and 6 months in both groups and change in bone age for chronological age was also similar in the two groups. In the rhGH group, fasting insulin increased from 4·0 (2·0, 11·0) to 7·0 mU/l (2·0, 16·0) (P = 0·02), whereas in the Ctrl group, it was 3·0 (1·2, 12·7) and 3·8 mU/l (2·1, 7·0) (P = 0·72), respectively. CONCLUSIONS Although this pilot trial shows that rhGH can improve short-term linear growth in children with CD, the clinical efficacy of this therapy needs to be further studied in longer-term studies of growth, glucose homeostasis and disease status.
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Sze NN, Wong SC, Pei X, Choi PW, Lo YK. Is a combined enforcement and penalty strategy effective in combating red light violations? An aggregate model of violation behavior in Hong Kong. ACCIDENT; ANALYSIS AND PREVENTION 2011; 43:265-271. [PMID: 21094323 DOI: 10.1016/j.aap.2010.08.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 08/09/2010] [Accepted: 08/18/2010] [Indexed: 05/30/2023]
Abstract
Red light violations are a major cause of traffic crashes at signalized intersections. In Hong Kong, prosecutions for red light violations have increased in the past decade. An automated enforcement camera system has been established to combat this prohibited driver behavior. In addition, both demerit points and financial penalties were revised upwards in 2006 to strengthen the deterrent effect of the system. An observational study of driver tendency to run a red light was conducted to evaluate the effectiveness of the combined penalty and camera strategy. Both the short- and long-term effects of the strategy on red light violations were estimated. The influences of factors including temporal variation, the presence of a red light camera, geometric design, and traffic control type were also determined with an aggregate count data model. The results show that the frequency of red light violations significantly decreased after the implementation of the new penalty system, and that the reduction remained significant one year after implementation. Interestingly, no evidence was found for an association between the frequency of red light violations and the presence of a red light camera.
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Wong SC, Smyth A, McNeill E, Galloway PJ, Hassan K, McGrogan P, Ahmed SF. The growth hormone insulin-like growth factor 1 axis in children and adolescents with inflammatory bowel disease and growth retardation. Clin Endocrinol (Oxf) 2010; 73:220-8. [PMID: 20184596 DOI: 10.1111/j.1365-2265.2010.03799.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CONTEXT There is scarce knowledge about the growth hormone (GH) insulin-like growth factor-1 (IGF1) axis in children & adolescents with inflammatory bowel disease (IBD) and growth retardation. OBJECTIVE To describe the pattern of GH and IGF1 secretion in children & adolescents with IBD. DESIGN A retrospective review of 28 patients (23 M) of IBD (25 Crohn's Disease and three Ulcerative Colitis) and growth retardation who had investigation of the GH/IGF-1 axis. Height velocity (HV) and serum IGF1 were converted to standard deviation score (SDS); to account for delayed puberty in girls over 11 years and boys over 12 years, HV and serum IGF1 SDS were adjusted for bone age. RESULTS Median (range) age and Ht SDS at the time of endocrine evaluation was 14.3 years (7.7,17.0) and -2.0(-3.6,-0.9), respectively. Median HVSDS over the prior 12 months was -2.2(-7.7,2.8). Median peak serum GH on insulin tolerance test (ITT) was 5.8 mcg/l (1.3, 24.0), and median serum IGF1 SDS was -0.9(-3.1, 0.1). Five of 28 (18%) had a peak serum GH of >12 mcg/l. Overall, four had biochemical evidence of functional GH deficiency (peak GH < 3 mcg/l and IGF1 SDS < 0) and 11 children had biochemical evidence suggesting GH resistance (peak GH > 6 mcg/l and IGF1 SDS < 0). However, only one child had a peak serum GH > 6 mcg/l and a very low IGF1 SDS of <-2.0. There was a negative association between peak serum GH and Ht SDS (r = -0.49, P = 0.008), but there was no association with HV and there was no association between IGF1 SDS and Ht or HV SDS. IGF1 SDS showed a negative association with erythrocyte sedimentation rate (r = -0.41, P = 0.04). CONCLUSION Growth retardation in children and adolescents with IBD is commonly associated with a range of biochemical abnormalities ranging from functional GH deficiency to GH resistance. In these children, poor relationship between systemic markers of growth and height velocity point to an important role of growth factors at the target organ level in modulating growth in children with IBD. The value of assessing the GH/IGF-1 axis and whether it predicts subsequent response to growth-promoting therapy requires further exploration.
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Wong OF, Tsui KL, Lam TSK, Sze NN, Wong SC, Lau FL, Liu SH. Prevalence of drugged drivers among non-fatal driver casualties presenting to a trauma centre in Hong Kong. Hong Kong Med J 2010; 16:246-251. [PMID: 20683065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
Abstract
OBJECTIVE To investigate the prevalence and characteristics of abusive drug exposure among non-fatal motor vehicle driver casualties presenting to a designated trauma centre in Hong Kong. DESIGN Cross-sectional study. SETTING Designated trauma centre/regional accident and emergency department in Hong Kong. SUBJECTS Non-fatal motor vehicle driver casualties who presented to the trauma centre from 1 January 2007 to 31 December 2007. MAIN OUTCOME MEASURES Screening of abusive drug exposure using commercial bedside urine immunoassay kits. RESULTS Drug screening was performed in 395 injured drivers, 10% of whom tested positive for the drugs of interest. Ketamine was the most commonly detected abusive substance (found in 45% of the subjects). A significantly higher proportion of young drivers (aged <25 years) screened positive (odds ratio=2.3; 95% confidence interval, 1.0-5.2; P=0.04), with the rate being 21%. The presence of these drugs in urine was related to the time of occurrence of the crash; those occurring between midnight and dawn revealed a trend towards a higher proportion of casualties testing drug-positive (odds ratio=2.2; 95% confidence interval, 0.9-5.3; P=0.07). There were no significant differences in the frequency of persons testing positive for the screened drugs with respect to gender, class of motor vehicle driven, or the day of the week on which the crash occurred. CONCLUSIONS The prevalence of drugged driving among non-fatal casualties in our series of Hong Kong drivers was 10%. The frequency of such drivers testing positive for drugs was significantly higher in persons aged less than 25 years. These findings indicate a need to amend existing laws and implement on-site drug screening for suspected drugged drivers.
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Angunawela RI, Liyanage SE, Wong SC, Little BC. Intraocular pressure and visual outcomes following intracameral triamcinolone assisted anterior vitrectomy in complicated cataract surgery. Br J Ophthalmol 2009; 93:1691-2. [PMID: 19939800 DOI: 10.1136/bjo.2009.158493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Wong SC, Ramkissoon YD, Lopez M, Page K, Parkin IP, Sullivan PM. Use of hydroxypropylmethylcellulose 2% for removing adherent silicone oil from silicone intraocular lenses. Br J Ophthalmol 2009; 93:1085-8. [DOI: 10.1136/bjo.2008.153007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Xia Y, Wong SC, Shu CW. Dynamic continuum pedestrian flow model with memory effect. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:066113. [PMID: 19658570 DOI: 10.1103/physreve.79.066113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Indexed: 05/28/2023]
Abstract
In this paper, we develop a macroscopic model for pedestrian flow using the dynamic continuum modeling approach. We consider a two-dimensional walking facility that is represented as a continuum within which pedestrians can move freely in any direction. A pedestrian chooses a route based on his or her memory of the shortest path to the desired destination when the facility is empty and, at the same time, tries to avoid high densities. In this model, pedestrian flow is governed by a two-dimensional conservation law, and a general speed-flow-density relationship is considered. The model equation is solved numerically using the discontinuous Galerkin method, and a numerical example is employed to demonstrate both the model and the effectiveness of the numerical method.
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Tsui KL, So FL, Sze NN, Wong SC, Leung TF. Misclassification of injury severity among road casualties in police reports. ACCIDENT; ANALYSIS AND PREVENTION 2009; 41:84-89. [PMID: 19114141 DOI: 10.1016/j.aap.2008.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 08/25/2008] [Accepted: 09/12/2008] [Indexed: 05/27/2023]
Abstract
This study aims to evaluate the discordance between police reports of injury severity among road casualties and the length of hospital stay and the Injury Severity Scale (ISS) by linking information from the crash records of the Hong Kong Police with the trauma records of a regional hospital. Sensitivity and specificity analyses suggest that police injury grading diverges noticeably from the definition of a 12-h hospital stay. Police reports overestimate injury severity remarkably. The results of logistic regression indicate that age, the ISS, and the position of the victim significantly determine the likelihood of police injury misclassification. Furthermore, an optimal demarcation point of the length of hospital stay for serious injury is estimated.
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Wong SC, MacRae VE, Gracie JA, McInnes IB, Galea P, Gardner-Medwin J, Ahmed SF. Inflammatory cytokines in juvenile idiopathic arthritis: effects on physical growth and the insulin-like-growth factor axis. Growth Horm IGF Res 2008; 18:369-378. [PMID: 18378173 DOI: 10.1016/j.ghir.2008.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 01/06/2008] [Accepted: 01/23/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the relationship between markers of inflammation with physical growth and systemic markers of GH secretion in JIA. DESIGN This is a cross sectional prospective study of patients with JIA recruited during therapeutic arthrocentesis of 17 children with JIA (F,10): 8 oligoarticular (OJIA) and 9 polyarticular (PJIA). RESULTS Median adjusted height (AHt) SDS was -0.3 (-2.2 to 1.6). Serum ALS SDS (median -1.3, range -2.7 to -0.6) was reduced compared with serum IGFBP-3 SDS (median -0.5, range -7.7 to 2.3) and IGF-1 SDS (median -0.2, range -0.5 to 0.5). Log serum IL5 (95% CI -3.25, -0.81) and log serum IL15 (95% CI -9.58, -4.10) were independent factors associated with AHt SDS. Inflammatory cytokines individually showed no association with IGF-1, IGFBP-1, -2, -3 and ALS. CONCLUSION Children with JIA and mild degree of growth retardation show decreased ALS and IGFBP-3. Cytokines did not show an association to systemic markers of GH secretion. However, this study reports the novel, preliminary association between serum levels of IL5 and IL15 and the extent of short stature.
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Wong SC, Khanna S, Rashid R, Ahmed SF. Auditing bone densitometry and fractures in children with chronic disease. Arch Dis Child 2008; 93:705-7. [PMID: 18285391 DOI: 10.1136/adc.2007.118265] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In a retrospective analysis of bone densitometry scans performed in an audit of 576 children with chronic disease, lean-mass-adjusted bone mineral content (BMC) for the total body and the lumbar spine was marginally lower in children with fractures. However, the predictive ability of different bone mineral densities (BM) and BMC cut-offs to identify fracture risk in children with chronic disease needs to be tested for specific disease conditions in larger prospective studies.
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Ho HH, Min JK, Lin F, Wong SC, Bergman G. Images in cardiovascular medicine. Calcified amorphous tumor of the heart. Circulation 2008; 117:e171-2. [PMID: 18316492 DOI: 10.1161/circulationaha.107.730838] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wong SC, Hassan K, McGrogan P, Weaver LT, Ahmed SF. The effects of recombinant human growth hormone on linear growth in children with Crohn's disease and short stature. J Pediatr Endocrinol Metab 2007; 20:1315-24. [PMID: 18341091 DOI: 10.1515/jpem.2007.20.12.1315] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND/AIMS The efficacy of recombinant human growth hormone (rhGH) in treating the growth failure associated with Crohn's disease (CD) is unclear. METHODS Retrospective data analysis at 12 months before (T-12), 6 months before (T-6), at baseline (T+0), 6 months after (T+6) and 12 months after (T+12) rhGH treatment in seven patients with CD (five males). RESULTS Median chronological age (CA) and median difference between CA and bone age was 15.9 yr (range, 13.0 to 17.9) and 1.7 yr (-0.7 to 3.3), respectively. Median dose of rhGH at T+0 was 0.23 mg/wk (0.15 to 0.31). Pubertal status remained unchanged in 6/7 patients. Median albumin and C-reactive protein (CRP) were similar at T+0 and T+6. Median height SDS at T+0, T+6 and T+12 was -2.2 (-4.0 to -1.5), -1.9 (-4.1 to -0.8), -1.9 (-4.1 to -0.7), respectively (NS). Median height velocity (HV) SDS at T+0 and T+6 was -2.5 (-4.8 to 1.4) and -0.9 (-5.3 to 3.4), respectively (NS). There was a positive correlation between percentage change in HV SDS at T+6 and dose of rhGH at T+0 (r = 0.8, p = 0.03). CONCLUSION Introduction of rhGH therapy was associated with a cessation in the deterioration in linear growth. However, an improvement in height SDS was not observed over the period of the study. Future studies should explore the efficacy of a higher dose of rhGH in CD.
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Wong SC, Sze NN, Li YC. Contributory factors to traffic crashes at signalized intersections in Hong Kong. ACCIDENT; ANALYSIS AND PREVENTION 2007; 39:1107-1113. [PMID: 17920832 DOI: 10.1016/j.aap.2007.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Revised: 02/12/2007] [Accepted: 02/17/2007] [Indexed: 05/25/2023]
Abstract
Efficient geometric design and signal timing not only improve operational performance at signalized intersections by expanding capacity and reducing traffic delays, but also result in an appreciable reduction in traffic conflicts, and thus better road safety. Information on the incidence of crashes, traffic flow, geometric design, road environment, and traffic control at 262 signalized intersections in Hong Kong during 2002 and 2003 are incorporated into a crash prediction model. Poisson regression and negative binomial regression are used to quantify the influence of possible contributory factors on the incidence of killed and severe injury (KSI) crashes and slight injury crashes, respectively, while possible interventions by traffic flow are controlled. The results for the incidence of slight injury crashes reveal that the road environment, degree of curvature, and presence of tram stops are significant factors, and that traffic volume has a diminishing effect on the crash risk. The presence of tram stops, number of pedestrian streams, road environment, proportion of commercial vehicles, average lane width, and degree of curvature increase the risk of KSI crashes, but the effect of traffic volume is negligible.
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Sze NN, Wong SC. Diagnostic analysis of the logistic model for pedestrian injury severity in traffic crashes. ACCIDENT; ANALYSIS AND PREVENTION 2007; 39:1267-1278. [PMID: 17920851 DOI: 10.1016/j.aap.2007.03.017] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 03/03/2007] [Accepted: 03/25/2007] [Indexed: 05/25/2023]
Abstract
This study attempts to evaluate the injury risk of pedestrian casualties in traffic crashes and to explore the factors that contribute to mortality and severe injury, using the comprehensive historical crash record that is maintained by the Hong Kong Transport Department. The injury, demographic, crash, environmental, geometric, and traffic characteristics of 73,746 pedestrian casualties that were involved in traffic crashes from 1991 to 2004 are considered. Binary logistic regression is used to determine the associations between the probability of fatality and severe injury and all contributory factors. A consideration of the influence of implicit attributes on the trend of pedestrian injury risk, temporal confounding, and interaction effects is progressively incorporated into the predictive model. To verify the goodness-of-fit of the proposed model, the Hosmer-Lemeshow test and logistic regression diagnostics are conducted. It is revealed that there is a decreasing trend in pedestrian injury risk, controlling for the influences of demographic, road environment, and other risk factors. In addition, the influences of pedestrian behavior, traffic congestion, and junction type on pedestrian injury risk are subject to temporal variation.
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MacRae VE, Wong SC, Smith W, Gracie A, McInnes I, Galea P, Gardner-Medwin J, Farquharson C, Ahmed SF. Cytokine profiling and in vitro studies of murine bone growth using biological fluids from children with juvenile idiopathic arthritis. Clin Endocrinol (Oxf) 2007; 67:442-8. [PMID: 17555514 DOI: 10.1111/j.1365-2265.2007.02908.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Growth retardation in children with chronic inflammatory disease may be partly due to direct effects of pro-inflammatory cytokines on the growth plate and requires further investigation. DESIGN This study assessed the cytokine concentrations in serum and synovial fluid (SF) in juvenile idiopathic arthritis (JIA), and determined the effect of the biological fluid on cultured murine metatarsal growth. PATIENTS Serum and SF were obtained from four children attending for arthrocentesis (child A, systemic; children B, C and D, oligoarticular). In addition, serum samples were obtained from four more children (children E and F, polyarticular; child G, oligoarticular). MEASUREMENTS Anthropometry, cytokine levels and longitudinal bone growth were assessed. RESULTS Cytokines were elevated to a variable extent in the samples. Although all serum samples were associated with reduced metatarsal growth, only SF from child A and child B reduced metatarsal growth. Metatarsals treated with child A's SF showed reduced proliferation, reduced proliferative and mineralizing zone width, and increased hypertrophic zone width. Tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 concentrations were elevated in child A's SF. However, SF exposure with neutralizing antibodies to these cytokines or IGF-1 did not improve metatarsal growth. CONCLUSION SF and serum JIA samples can impair bone growth at the growth plate. In synovial fluid, the effect is variable but resistant to treatment with IL-1beta, IL-6 and TNF-alpha specific antibodies and IGF-1, suggesting that other factors in this biological fluid may also have an effect on longitudinal growth through IGF-1-independent mechanisms.
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MacRae VE, Wong SC, Farquharson C, Ahmed SF. Cytokine actions in growth disorders associated with pediatric chronic inflammatory diseases (review). Int J Mol Med 2007; 18:1011-8. [PMID: 17089003 DOI: 10.3892/ijmm.18.6.1011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Growth disorders are commonly observed in children suffering from chronic inflammatory diseases such as Juvenile Idiopathic Arthritis (JIA) and Inflammatory Bowel Disease (IBD). These disorders range from general growth retardation to local acceleration of growth in the affected limb and are associated with the increased production of pro-inflammatory cytokines. In this article, we review how cytokines influence child growth by exerting a local effect at the level of the growth plate, and through systemic effects throughout the whole body.
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Ng SM, Wong SC, Isherwood DM, Didi M. Biochemical severity of thyroid ectopia in congenital hypothyroidism demonstrates sexual dimorphism. Eur J Endocrinol 2007; 156:49-53. [PMID: 17218725 DOI: 10.1530/eje.1.02319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND A recent study suggested that sexual dimorphism affects initial thyroid function in congenital hypothyroidism (CH) but differs according to aetiology of CH. AIMS To determine if sexual dimorphism was associated with biochemical severity of CH and its aetiology in our large British population. METHODS We examined retrospectively the initial thyroid function tests of 140 infants diagnosed with CH from screening. All infants underwent Tc-pertechnetate radionuclide scans at diagnosis to establish the aetiology of CH prior to commencement of treatment. Patients were classified into athyreosis, ectopia and presumed dyshormonogenesis on the basis of thyroid scans. A comparison of males and females were made within the three aetiological groups for gestational age, birth weight, initial dose of levothyroxine (LT4), screening TSH, confirmatory plasma thyroxine (T4), confirmatory plasma TSH and age of TSH suppression. RESULTS There was no significant difference between sexes for gestation, birth weight and initial treatment dose in all aetiological subgroups. In thyroid ectopia, screening TSH and confirmatory plasma TSH were significantly higher in females compared with males (P < 0.01), while confirmatory plasma T4 were significantly lower in females (P < 0.05). No difference was detected between males and females in athyreosis and dyshormonogenesis subgroups for screening TSH, confirmatory plasma TSH and total T4. CONCLUSION Sexual dimorphism influenced the biochemical severity of thyroid ectopia in congenital hypothyroidism in our British population. However, this effect was not apparent in patients with athyreosis or dyshormonogenesis. Further advances in the molecular genetics of CH are essential to evaluate this phenomenon further.
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Ng SM, Wong SC, Paize F, Chakkarapani E, Newland P, Isherwood DM, Didi M. Delay in screening premature infants for congenital hypothyroidism. Arch Dis Child Fetal Neonatal Ed 2006; 91:F465-6. [PMID: 17056851 PMCID: PMC2672776 DOI: 10.1136/adc.2005.091264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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