Reporting of paediatric osteoporotic vertebral fractures in Duchenne muscular dystrophy and potential impact on clinical management: the need for standardised and structured reporting

BACKGROUND

In boys with Duchenne muscular dystrophy (DMD), initiation of bisphosphonate is recommended upon identification of moderate or severe vertebral fractures, even if asymptomatic. Clear radiological reporting is important for consistency of clinical interpretation and management.

OBJECTIVES

To audit radiology reports of spine imaging for vertebral fracture assessment in DMD, and assess potential impact on diagnosis and management.

MATERIALS AND METHODS

Lateral thoracolumbar spine imaging (71 lateral spine radiographs and 13 lateral dual energy absorptiometry spine image) in 84 boys with DMD performed across two centres. Anonymised radiology reports by paediatric radiologists were circulated to two neuromuscular clinicians and two endocrinologists. Clinicians determined if there was vertebral fracture, no vertebral fracture, or unclear interpretation. Endocrinologists also determined if bisphosphonate was indicated. A single observer (a clinician with expertise in vertebral fracture assessment) performed vertebral fracture assessment in 37 images and re-reported using a structured format. Structured reports were re-circulated to the four clinicians to re-evaluate the degree of concordance in clinical diagnosis of vertebral fracture and treatment decisions with bisphosphonate.

RESULTS

The term "fracture" was used in 25/84 (30%) radiology reports and only in 8/43 (19%) with description of vertebral body abnormalities. Fracture grading was included in 7/43 (16%) radiology reports. Diagnostic concordance by the clinicians was noted in 36/84 (43%). Unclear interpretation was noted in 22% to 51% based on radiology reports. No unclear interpretation was noted with structured reports. Complete diagnostic (37/37, 100%) and treatment (37/37, 100%) concordance was noted with the structured reports, whereas complete diagnostic and treatment concordance was noted in only 16/37 (43%) and 17/37 (46%) of the radiology reports, respectively.

CONCLUSION

Only a third of radiology reports of spine imaging in DMD explicitly used the terminology "fracture". Grading was only noted in a small percentage. Variability in diagnostic interpretation by clinicians may lead to differing management plans. As identification of vertebral fracture is a trigger for treatment, developing reporting guidelines for paediatric vertebral fracture assessment will improve care. A structured template should be introduced for radiological reporting of paediatric vertebral fracture assessment.

Analysis of the injury severity of motor vehicle-pedestrian crashes at urban intersections using spatiotemporal logistic regression models

This paper conducted a comprehensive study on the injury severity of motor vehicle-pedestrian crashes at 489 urban intersections across a dense road network based on high-resolution accident data recorded by the police from 2010 to 2019 in Hong Kong. Given that accounting for the spatial and temporal correlations simultaneously among crash data can contribute to unbiased parameter estimations for exogenous variables and improved model performance, we developed spatiotemporal logistic regression models with various spatial formulations and temporal configurations. The results indicated that the model with the Leroux conditional autoregressive prior and random walk structure outperformed other alternatives in terms of goodness-of-fit and classification accuracy. According to the parameter estimates, pedestrian age, head injury, pedestrian location, pedestrian actions, driver maneuvers, vehicle type, first point of collision, and traffic congestion status significantly affected the severity of pedestrian injuries. On the basis of our analysis, a range of targeted countermeasures integrating safety education, traffic enforcement, road design, and intelligent traffic technologies were proposed to improve the safe mobility of pedestrians at urban intersections. The present study provides a rich and sound toolkit for safety analysts to deal with spatiotemporal correlations when modeling crashes aggregated at contiguous spatial units within multiple years.

Comparison of adhesive single-lead cardiac ECG patch device with Holter monitoring for detecting atrial fibrillation after an acute cerebral ischemic event: An interim analysis

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health Malaysia

Background

Stroke secondary to atrial fibrillation (AF) is common and often associated with higher risk of stroke recurrence. Detection of AF is challenging due to brief unpredictable episodes of AF runs, especially in patients whose admission electrocardiogram (ECG) demonstrates a sinus rhythm. Probability of AF detection may be higher with early initiation of prolonged ECG monitoring.

Purpose

To compare diagnostic yield of 7-day cardiac ECG patch versus 24-hour Holter monitoring for detecting AF≥30 seconds; to identify predictors of AF in stroke patients; to determine if 7-day cardiac ECG patch results in a change in clinical practice.

Methods

In this investigator-initiated prospective study with pairwise comparison of 24-hour Holter and 7-day cardiac ECG patch monitoring, 150 patients who were admitted to a tertiary referral centre with acute ischemic stroke (AIS) or transient ischemic attack (TIA) within 1 week, without known AF, and had sinus rhythm in the admission 12-lead ECG were enrolled. Each patient underwent simultaneous 24-hour Holter and 7-day cardiac ECG patch monitoring. Routine transthoracic echocardiography was performed on each patient to assess cardiac function and exclude intracardiac thrombus.

Results

There were 102 (68.0%) male patients. 12 (8.0%) patients had underlying history of coronary artery disease; 26 (17.3%) had recurrent stroke or TIA. On admission, median NIH Stroke scale was 4; 18 (12.0%) patients had thrombolysis with alteplase. On transthoracic echocardiography, none had intracardiac thrombus.

Both Holter and cardiac ECG patch monitoring were initiated simultaneously at median 2 days after index stroke event. Of 150 patients, 17 (11.3%) detected AF ≥30 seconds. Of these 17 patients, 7 (4.7%) had AF detected within the first 24 hours on both Holter and cardiac ECG patch; 10 (6.7%) were detected after 24 hours on cardiac ECG patch only. Number needed to screen to detect one AF was 6. Compliance to 7-day cardiac ECG patch monitoring was 81.3%.

There was no significant difference in age among patients with and without AF. Although left atrium (LA) was not found to be dilated in patients with AF, LA volume index was significantly higher (28.3±15.9 vs 21.8±8.5, p=0.018) and LA emptying fraction (LAEF) was significantly lower (38.0%±30.2 vs 52.6%±16.7, p=0.007). The prolonged 7-day cardiac ECG monitoring patch resulted in 1.5-fold increase in prescription of anticoagulation therapy.

Conclusions

A 7-day cardiac ECG patch monitoring detected more patients with AF ≥30 seconds than 24-hour Holter monitoring and resulted in increase in prescription of anticoagulation therapy. Higher LA volume index and lower LA emptying fraction were predictors of AF in patients with a recent stroke.

An assessment of the effect of green signal countdown timers on drivers' behavior and on road safety at intersections, based on driving simulator experiments and naturalistic observation studies

INTRODUCTION

Motor-vehicle crashes at signalized intersections are a significant traffic safety problem. To address this problem, many Asian cities have installed signal countdown displays at signalized intersections, aiming to assist drivers to make correct decisions in response to traffic signals.

METHOD

In this study, we assessed the short-term and long-term effects of green signal countdown timers (GSCTs) on road safety, using a combination of driving simulator experiments and naturalistic observations.

RESULTS

In our driving simulator experiments, 80 participants drove at 50 km/h in scenarios in which a car either approached a signalized intersection alone or following another car. In naturalistic observations, short-term (1-week) and long-term (1-year) intersection safety in the presence and absence of GSCTs were compared. These observations revealed that GSCTs reduced the number of red-light-running violations over the short term, but not over the long term. In fact, GSCTs appeared to lead to an overall increase in rear-end crash risk at intersections, as their presence resulted in drivers exhibiting more sudden acceleration and braking, and altered intersection-crossing speeds and patterns.

CONCLUSIONS

The results suggest that GSCTs worsen safety at signalized intersections, and thus their removal should be considered.

Uncertainty matters: Bayesian modeling of bicycle crashes with incomplete exposure data

BACKGROUND

One major challenge faced by neighborhood-level bicycle safety analysis is the lack of complete and reliable exposure data for the entire area under investigation. Although the conventional travel-diary surveys, together with the emerging smartphone fitness applications and bike-sharing systems, provide straightforward and valuable opportunities to estimate territory-wide bicycle activities, the obtained ridership suffers inherently from underreporting.

METHODS

We introduced the Bayesian simultaneous-equation model as a sound methodological alternative here to address the uncertainty arising from incomplete exposure data when modeling bicycle crashes. The proposed method was successfully fitted to a crowdsourced dataset of 792 bicycle-motor vehicle (BMV) crashes aggregated from 209 neighborhoods over a 3-year period in Hong Kong.

RESULTS

Our analysis empirically demonstrated the bias due to omission of activity-based exposure measures or to the direct use of cycling distance extracted from the travel-diary survey without correcting for incompleteness. By modeling bicycle activities and the frequency of BMV crashes simultaneously, we also provided new evidence that an expansion of bicycle infrastructure was likely associated with a significant increase in cycling levels and a substantial reduction in the risk of BMV crashes, despite a slight increase in the absolute number of BMV crashes.

CONCLUSIONS

Our approach is promising in adjusting for the uncertainty in raw exposure data, extrapolating the missing exposure values, and untangling the linkage among built environment, bicycle activities, and the frequency of BMV crashes within a unified framework. To promote safer cycling, designated facilities should be provided to consecutively separate cyclists from motor vehicles.

Two-year plaque level outcomes involving the left anterior descending artery: insights from the Lipid-Rich Plaque study

Background

Coronary artery disease (CAD) is more frequently seen in the left anterior descending artery (LAD). LAD disease resulting in an acute anterior wall myocardial infarction (MI) is associated with a low left ventricular ejection fraction and invariably a worsened prognosis. The Lipid Rich Plaque (LRP) Study reported the strong association between NIRS-IVUS derived max4mmLCBI and future plaque events in non-culprit vessels.

Objective

To report the events involving the LAD versus the other major coronary vessels in the Lipid-Rich Plaque study.

Methods

The LRP Study was an international, multicenter, prospective cohort study conducted in patients with suspected CAD who underwent cardiac catheterization with possible ad hoc percutaneous coronary intervention (PCI) for an index event. Plaque level events within the subsequent 2 years were adjudicated. Plaque level events were defined as the composite of cardiac death, cardiac arrest, non-fatal MI, acute coronary syndrome (ACS), revascularization by coronary artery bypass grafting (CABG) or PCI, and rehospitalization for angina with >20% stenosis progression related and unrelated to the treatment at index procedure. All together these events were reported as Non-Culprit Lesion-related Major Adverse Cardiac Events (NC-MACE). Prespecified subgroups of segments were defined according to LAD (vs. non-LAD) with maxLCBI4mm ≤400 or >400.

Results

A total of 57 plaque events occurred through 2 years of follow-up. More than half occurred in the LAD, followed by the LCX and the RCA. There were more, albeit non-statistically significant, lipid-rich plaques in the LAD, compared to the LCX and RCA: 12.5% vs 10.4% and 11.3%, respectively, p=0.097. A minimum lumen area (MLA) ≤4mm2 within the maxLCBI4mm was observed more in the LAD and the LCX, compared to the RCA: 34.1% vs 25.9% vs 13.7%, respectively, p<0.001. Lipid rich plaque (maxLCBI4mm>400) was present in 20/57 (35.1%) of the plaque level events, a large PB (≥70%) was present in 6/57 (10.5%), and a small MLA (≤4mm2) was present in 26/57 (45.6%). Out of the 57 plaque level events, 4 (7%) had all three high risk plaque characteristics.

Presence of an elevated maxLCBI4mm (>400) was predictive of NC-MACE in all subgroups (for LAD >400 HR 4.32; 95% CI (1.93, 9.69; p 0.0004) and for the non-LAD >400 HR 2.56; 95% CI (1.06, 6.17; p 0.0354).

Conclusion

Non-culprit segments in the LAD with maxLCBI4mm values >400 were more frequently associated with plaque level events than in the lipid -rich segments in the other epicardial vessels. This sub-study results point to the unequivocal value of maxLCBI4mm>400 in predicting future plaque level events especially in the LAD.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Infraredx Plaque Events-Ware Segment Locations

On random-parameter count models for out-of-sample crash prediction: Accounting for the variances of random-parameter distributions

One challenge faced by the random-parameter count models for crash prediction is the unavailability of unique coefficients for out-of-sample observations. The means of the random-parameter distributions are typically used without explicit consideration of the variances. In this study, by virtue of the Taylor series expansion, we proposed a straightforward yet analytic solution to include both the means and variances of random parameters for unbiased prediction. We then theoretically quantified the systematic bias arising from the omission of the variances of random parameters. Our numerical experiment further demonstrated that simply using the means of random parameters to predict the number of crashes for out-of-sample observations is fundamentally incorrect, which necessarily results in the underprediction of crash counts. Given the widespread use and ongoing prevalence of the random-parameter approach in crash analysis, special caution should be taken to avoid this silent pitfall when applying it for predictive purposes.

Findings from the first public COVID-19 temporary test centre in Hong Kong

INTRODUCTION

The Hospital Authority of Hong Kong Special Administrative Region established a coronavirus disease 2019 (COVID-19) temporary test centre at the AsiaWorld-Expo from March 2020 to April 2020, which allowed high-risk individuals to undergo early assessment of potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study reviewed the characteristics and outcomes of individuals who attended the centre for COVID-19 testing.

METHODS

This retrospective cross-sectional study collected epidemiological and clinical data. The primary outcome was a positive or negative SARS-CoV-2 test result, according to reverse transcription polymerase chain reaction analyses of pooled nasopharyngeal and throat swabs collected at the centre. The relationships of clinical characteristics with SARS-CoV-2 positive test results were assessed by multivariable binary logistic regression.

RESULTS

Of 1258 attendees included in the analysis, 86 individuals tested positive for SARS-CoV-2 infection (positivity rate=6.84%; 95% confidence interval [CI]=5.57%-8.37%). Of these 86 individuals, 40 (46.5%) were aged 15 to 24 years and 81 (94.2%) had a history of recent travel. Symptoms were reported by 86.0% and 96.3% of individuals with positive and negative test results, respectively. The clinical characteristics most strongly associated with a positive test result were anosmia (adjusted odds ratio [OR_adj]=8.30; 95% CI=1.12-127.09) and fever OR_adj=1.32; 95% CI=1.02-3.28).

CONCLUSION

The temporary test centre successfully helped identify individuals with COVID-19 who exhibited mild disease symptoms. Healthcare providers should carefully consider the epidemiological and clinical characteristics of COVID-19 to arrange early testing to reduce community spread.

Right-looking habit and maladaptation of pedestrians in areas with unfamiliar driving rules

Both left-driving (LD) and right-driving (RD) rules are used around the world. When traveling to places with different driving rules, pedestrians are likely to make mistakes. To investigate the frequency of such mistakes, a case study was conducted with pedestrians in Hong Kong, which follows LD rules, i.e., traffic drives on the left. The study aimed to probe the effects of hometown driving rules and length of stay on pedestrians' right-looking habit and maladaptation to the Hong Kong LD system and determine the mediating effect of the right-looking habit. A face-to-face survey was conducted with 581 respondents at seven locations in Hong Kong. A structural equation model was applied to determine the relationship among hometown driving rules, length of stay, right-looking habit, and maladaptation. The model exhibited good fitness (χ²/degrees of freedom=2.154; comparative fit index=0.989; Tucker-Lewis Index=0.980; and root mean square error of approximation=0.045). The results revealed that hometown driving rules and length of stay had positive effects on the right-looking habit, and hometown driving rules had a direct negative effect on maladaptation. The right-looking habit partially mediated the effect of hometown driving rules and fully mediated the effect of length of stay on maladaptation to the Hong Kong LD system. It was found that when foreign pedestrians were in areas with unfamiliar driving rules, they tended to practice their hometown looking habits, especially foreign pedestrians who had stayed only for a short time; this behavior differed significantly from that of local pedestrians, and it led to more severe maladaptation. The findings of this study provide empirical evidence of pedestrians' looking habits and maladaptation in areas with unfamiliar driving systems and have significant implications for improving the safety of foreign pedestrians.

Towards activity-based exposure measures in spatial analysis of pedestrian-motor vehicle crashes

BACKGROUND

Although numerous efforts have been devoted to exploring the effects of area-wide factors on the frequency of pedestrian crashes in neighborhoods over the past two decades, existing studies have largely failed to provide a full picture of the factors that contribute to the incidence of zonal pedestrian crashes, due to the unavailability of reliable exposure data and use of less sound analytical methods.

METHODS

Based on a crowdsourced dataset in Hong Kong, we first proposed a procedure to extract pedestrian trajectories from travel-diary survey data. We then aggregated these data to 209 neighborhoods and developed a Bayesian spatially varying coefficients model to investigate the spatially non-stationary relationships between the number of pedestrian-motor vehicle (PMV) crashes and related risk factors. To dissect the role of pedestrian exposure, the estimated coefficients of models with population, walking trips, walking time, and walking distance as the measure of pedestrian exposure were presented and compared.

RESULTS

Our results indicated substantial inconsistencies in the effects of several risk factors between the models of population and activity-based exposure measures. The model using walking trips as the measure of pedestrian exposure had the best goodness-of-fit. We also provided new insights that in addition to the unstructured variability, heterogeneity in the effects of explanatory variables on the frequency of PMV crashes could also arise from the spatially correlated effects. After adjusting for vehicle volume and pedestrian activity, road density, intersection density, bus stop density, and the number of parking lots were found to be positively associated with PMV crash frequency, whereas the percentage of motorways and median monthly income had negative associations with the risk of PMV crashes.

CONCLUSIONS

The use of population or population density as a surrogate for pedestrian exposure when modeling the frequency of zonal pedestrian crashes is expected to produce biased estimations and invalid inferences. Spatial heterogeneity should also not be negligible when modeling pedestrian crashes involving contiguous spatial units.

Severity of passenger injuries on public buses: A comparative analysis of collision injuries and non-collision injuries

INTRODUCTION

Although public buses have been demonstrated as a relatively safe mode of transport, the number of injuries to public bus passengers is far from negligible. Existing studies of public bus safety have focused primarily on injuries caused by collisions. Surprisingly, limited effort has been devoted to identifying factors that increase the severity of passenger injuries in non-collision incidents.

METHOD

Our study therefore investigated the injury risk of public bus passengers involved in collision incidents and non-collision incidents comparatively, based on a police-reported dataset of 17,383 passengers injured on franchised public buses over a 10-year period in Hong Kong. A random parameters logistic model was established to estimate the likelihood of fatal and severe injuries to passengers as a function of various factors.

RESULTS

Our results indicated substantial inconsistences in the effects of risk factors between models of non-collision injuries and collision injuries. The severity of passenger injuries tended to increase significantly when non-collision incidents occurred due to excessive speed of bus drivers, on double-decker buses, in less urbanized areas, in winter, in heavy rains, during daytime, and at night without street lighting. Elderly female passengers were also found more likely to be fatally or severely injured in non-collision incidents if they lost their balance while boarding, alighting from, or standing on a bus. In comparison, the following factors were associated with a greater likelihood of fatal or severe injuries in collision incidents: elderly female passengers, standing passengers who lost balance, buses out of driver control, double-decker buses, collisions with vehicles or objects, and less urbanized areas. Practical Applications: Based on our comparative analysis, more targeted countermeasures, namely "4E" (engineering, enforcement, emergency, and education) and "3A" (awareness, appreciation, and assistance), were recommended to mitigate collision injuries and non-collision injuries to public bus passengers, respectively.

Risks to pedestrians in traffic systems with unfamiliar driving rules: a virtual reality approach

In this study, a virtual-reality (VR) pedestrian simulation method was used to evaluate the risks to pedestrians crossing streets in a traffic system with driving rules that were unfamiliar to them. Pedestrians from mainland China (which has a right-side driving (RD) system) and Hong Kong (which has a left-side driving (LD) system) were studied. Significant differences were observed between pedestrians from the different locations in terms of the direction in which the pedestrians habitually first looked before crossing. When exposed to an unfamiliar driving rule (i.e., traffic coming from an inconsistent direction in terms of participants' habitual driving system), the odds of participants from mainland China making an error in their looking behavior were 2.93 times those when exposed to a familiar driving rule. Road markings and traffic sound did not improve these participants' looking behavior. The results also show a negative correlation between inattentive looking behavior and time to collision (significant at the 1% level), as these errors lead to a shorter time to collision and increased the risk to pedestrians. The results of this study confirmed the risks for pedestrians traveling to places with unfamiliar driving rules and confirmed the existence of habitual looking behavior, and therefore provide evidence of the need for future studies to improve this problem. These may help decision makers take the risks of pedestrians from different driving rules into consideration in future traffic policymaking or traffic-facility improvements. The use of a VR simulation-based approach in this study provided a safe and controllable way to trial interventions and potential improvements without risking injury to participants, and thus may also be used for similar future studies.

Feasibility of Dual Energy X-Ray Absorptiometry Based Images for Measurement of Height, Sitting Height, and Leg Length in Children

BACKGROUND

Interpretation of pediatric bone mineral density by dual energy absorptiometry (DXA) requires adjustment for height (Ht). This is often not easily obtainable in nonambulant subjects.

AIMS

To investigate the feasibility of using DXA images to evaluate measurements of Ht, sitting height (SH), and leg length (LL).

METHODOLOGY

A total of 2 observers performed measurements of Ht, SH, and LL on 3 separate occasion using DXA digital images in 125 children. Intraclass correlation and relative technical error of measurement (rTEM) were performed to assess reliability of repeated measurements. In 25 children, Ht and SH were measured in clinic on the same day and Bland-Altman analysis was performed to compare DXA measured Ht, SH, LL with clinic measurements for these 25 children.

RESULTS

Intraclass correlation for DXA based Ht, SH, and LL measurements ranged from 0.996 to 0.998 (p < 0.0001). rTEM of Ht, SH, and LL for observer 1 was 0.0016%, 0.002%, and 0.0034%, respectively. rTEM of Ht, SH, and LL between observer 1 and 2 was 0.0047%, 0.0049%, and 0.0087%, respectively. Mean difference between clinic and DXA measurements from Bland-Altman plots were +0.57 cm (95% confidence interval [CI] -0.54 to +1.68) for Ht, +1.33cm (-1.60 to +4.24) for SH, and -0.76cm (-3.88 to +2.37) for LL.

CONCLUSIONS

Our study demonstrated for the first time that Ht, SH, and LL in children can be measured very precisely using DXA images. Ht can be measured accurately. We believe this may be a convenient method to obtain Ht measurements to allow size adjustment of DXA bone mineral density in immobile children with chronic conditions.

Not sick enough to worry? "Influenza-like" symptoms and work-related behavior among healthcare workers and other professionals: Results of a global survey

BACKGROUND

Healthcare workers (HCWs) and non-HCWs may contribute to the transmission of influenza-like illness (ILI) to colleagues and susceptible patients by working while sick (presenteeism). The present study aimed to explore the views and behavior of HCWs and non-HCWs towards the phenomenon of working while experiencing ILI.

METHODS

The study was a cross-sectional online survey conducted between October 2018 and January 2019 to explore sickness presenteeism and the behaviour of HCWs and non-HCWs when experiencing ILI. The survey questionnaire was distributed to the members and international networks of the International Society of Antimicrobial Chemotherapy (ISAC) Infection Prevention and Control (IPC) Working Group, as well as via social media platforms, including LinkedIn, Twitter and IPC Blog.

RESULTS

In total, 533 respondents from 49 countries participated (Europe 69.2%, Asia-Pacific 19.1%, the Americas 10.9%, and Africa 0.8%) representing 249 HCWs (46.7%) and 284 non-HCWs (53.2%). Overall, 312 (58.5%; 95% confidence interval [CI], 56.2-64.6) would continue to work when sick with ILI, with no variation between the two categories. Sixty-seven (26.9%) HCWs and forty-six (16.2%) non-HCWs would work with fever alone (p<0 .01) Most HCWs (89.2-99.2%) and non-HCWs (80%-96.5%) would work with "minor" ILI symptoms, such as sore throat, sinus cold, fatigue, sneezing, runny nose, mild cough and reduced appetite.

CONCLUSION

A future strategy to successfully prevent the transmission of ILI in healthcare settings should address sick-leave policy management, in addition to encouraging the uptake of influenza vaccine.

Systematic review of the effects of bisphosphonates on bone density and fracture incidence in childhood acute lymphoblastic leukaemia

Skeletal fragility is a common complication of childhood acute lymphoblastic leukaemia (ALL) but the impact of bisphosphonate therapy on bone mass and fracture is unclear. We aim to conduct a systematic review to evaluate the effects of bisphosphonates on bone mineral density (BMD) and fracture incidence in children with ALL.

METHODS

EMBASE, Medline and the Cochrane Library were thoroughly searched by two researchers. Inclusion criteria was any child under the age of 18 years with a diagnosis of ALL, who had received any bisphosphonate treatment and had serial measurements of bone density performed thereafter. All primary research studies of any study design, excluding case reports, were included.

RESULTS

Ten full text papers were identified with two exclusively meeting the inclusion criteria. Both studies administered bisphosphonates to children receiving maintenance chemotherapy for varying durations. Bone density was assessed at regular intervals by dual x-ray absorptiometry (DXA). The majority of participants had an improvement in bone density at the end of each study. However, no size adjustment of DXA data was performed. Limited information on fracture occurrence was provided by one study but did not include routine screening for vertebral fractures.

CONCLUSIONS

This systematic review identified that there is insufficient evidence to support routine use of prophylactic bisphosphonate therapy in childhood ALL for prevention of fracture and improvement of bone mass. Future well-designed clinical trials in those at highest risk of fractures in ALL are now needed.

Pubertal abnormalities in adolescents with chronic disease

Pubertal disorders in the context of chronic disease especially in those with chronic inflammatory disorders or those requiring prolonged periods of treatment with glucocorticoid are common reasons for referral to the paediatric endocrine clinic. Disorders of puberty are also common in adolescents with disability requiring management by paediatric endocrinologists. In these adolescents, impaired skeletal development is also observed and this can be associated with fragility fractures. Chronic inflammation, glucocorticoid and sub-optimal nutrition all impact on the hypothalamic-pituitary gonadal axis, and can also impact on skeletal development locally by their effects on the growth plate and bone. Addressing pubertal disorders is important to ensure adolescents with chronic disease are matched with their peers, promote adequate bone mass accrual and linear growth. Careful discussion with primary clinicians, the young person and the family is needed when instituting endocrine therapies to address puberty and manage bone health.

Temporal patterns of driving fatigue and driving performance among male taxi drivers in Hong Kong: A driving simulator approach

This study uses a questionnaire survey and a driving simulator test to investigate the temporal patterns of variations in driving fatigue and driving performance in 50 male taxi drivers in Hong Kong. Each driver visited the laboratory three times: before, during, and after a working shift. The survey contained a demographic questionnaire and the Brief Fatigue Inventory. A following-braking simulator test session was conducted at two speeds (50 and 80 km/h) by each driver at each of his three visits, and the driver's performance in brake reaction, lane control, speed control, and steering control were recorded. A random-effects modeling approach was incorporated to address the unobserved heterogeneity caused by the repeated measures. In the results, a recovery effect and a lagging effect were defined for the driving fatigue and performance measures because their temporal patterns were concavely quadratic and had a 1-hour delay compared to the temporal patterns of occupied taxi trips and taxi crash risk in Hong Kong. Demographic variables, such as net income and driver age, also had significant effects on the measured driving fatigue and performance. Policies regarding taxi management and operation based on the modeling results are proposed to alleviate the taxi safety situation in Hong Kong and worldwide.

Associations of dietary protein intake with bone mineral density: An observational study in 70,215 UK Biobank participants

PURPOSE

Adequate dietary protein intake is important for the maintenance of bone health; however, data in this area is ambiguous with some suggestion that high protein intake can have deleterious effects on bone health. The aim of the current study was to explore the associations of protein intake with bone mineral density (BMD).

METHODS

We used baseline data from the UK Biobank (participants aged 40-69 years) to examine the association of protein intake with BMD (measured by ultrasound). These associations were examined, in women (n = 39,066) and men (n = 31,149), after adjustment for socio-demographic and lifestyle confounders and co-morbidities.

RESULTS

Protein intake was positively and linearly associated with BMD in women (β-coefficient 0.010 [95% CI 0.005; 0.015, p < 0.0001]) and men (β-coefficient 0.008 [95% CI 0.000; 0.015, p = 0.044]); per 1.0 g/kg/day increment in protein intake, independently of socio-demographics, dietary factors and physical activity.

CONCLUSIONS

The current data have demonstrated that higher protein intakes are positively associated with BMD in both men and women. This indicates that higher protein intakes may be beneficial for both men and women.

Bayesian approach to model pedestrian crashes at signalized intersections with measurement errors in exposure

This study intended to identify the potential factors contributing to the occurrence of pedestrian crashes at signalized intersections in a densely populated city, based on a comprehensive dataset of 898 pedestrian crashes at 262 signalized intersections during 2010-2012 in Hong Kong. The detailed geometric design, traffic characteristics, signal control, built environment, along with the vehicle and pedestrian volumes were elaborately collected. A Bayesian measurement errors model was introduced as an alternative method to explicitly account for the uncertainties in volume data. To highlight the role played by exposure, models with and without pedestrian volume were estimated and compared. The results indicated that the omission of pedestrian volume in pedestrian crash frequency models would lead to reduced goodness-of-fit, biased parameter estimates, and incorrect inferences. Our empirical analysis demonstrated the existence of moderate uncertainties in pedestrian and vehicle volumes. Six variables were found to have a significant association with the number of pedestrian crashes at signalized intersections. The number of crossing pedestrians, the number of passing vehicles, the presence of curb parking, and the presence of ground-floor shops were positively related with pedestrian crash frequency, whereas the presence of playgrounds near intersections had a negative effect on pedestrian crash occurrences. Specifically, the presence of exclusive pedestrian signals for all crosswalks was found to significantly reduce the risk of pedestrian crashes by 43%. The present study is expected to shed more light on a deeper understanding of the environmental determinants of pedestrian crashes.

In-hospital infective endocarditis following transcatheter aortic valve replacement: a cross-sectional study of the National Inpatient Sample database in the USA

BACKGROUND

While the utilization of transcatheter aortic valve replacement (TAVR) for patients with severe aortic stenosis has been increasing, in-hospital infective endocarditis (IE) following TAVR has not been well described.

AIM

To identify in-hospital IE following TAVR.

METHODS

All patients who underwent TAVR between 2012 and 2014 were identified using the National Inpatient Sample database. Multi-variate logistic regression was performed to identify the predictors of in-hospital IE after TAVR.

FINDINGS

Of the 41,025 patients who received TAVR, 120 patients (0.3%) developed in-hospital IE. Viridans group streptococci (20.8%) was the most frequent causative organism for in-hospital IE, followed by Staphylococcus aureus (16.7%) and enterococci (8.3%). Patients who developed in-hospital IE after TAVR had significantly higher rates of death (20.8% vs 4.1%, P<0.001), septic shock (16.7% vs 0.8%, P<0.001), cardiogenic shock (12.5% vs 3.4%, P=0.02), acute kidney injury requiring haemodialysis (16.7% vs 1.6%, P<0.001), bleeding requiring transfusion (29.2% vs 11.3%, P=0.01), myocardial infarction (12.5% vs 2.1%, P<0.001) and permanent pacemaker removal (4.2% vs 0.05%, P<0.001) compared with patients without IE. Independent predictors of in-hospital IE after TAVR include younger age [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.89-0.95], drug abuse (OR 48.9, 95% CI 6.9-347.3) and human immunodeficiency virus (HIV) infection (OR 7.8, 95% CI 1.4-44.4).

CONCLUSION

IE occurred in 0.3% of patients after TAVR during the same hospitalization, resulting in higher rates of adverse outcomes including mortality. Patients with younger age, a history of drug abuse or HIV infection are at greater risk of in-hospital IE following TAVR, and would benefit from vigilant preventive measures perioperatively.

Ablation of Bax and Bak protects skeletal muscle against pressure-induced injury

Pressure-induced injury (PI), such as a pressure ulcer, in patients with limited mobility is a healthcare issue worldwide. PI is an injury to skin and its underlying tissue such as skeletal muscle. Muscle compression, composed of mechanical deformation of muscle and external load, leads to localized ischemia and subsequent unloading reperfusion and, hence, a pressure ulcer in bed-bound patients. Although the gross factors involved in PI have been identified, little is known about the exact disease mechanism or its links to apoptosis, autophagy and inflammation. Here, we report that PI is mediated by intrinsic apoptosis and exacerbated by autophagy. Conditional ablation of Bax and Bak activates the Akt-mTOR pathway and Bnip3-mediated mitophagy and preserves mitochondrial contents in compressed muscle. Moreover, we find that the presence/absence of Bax and Bak alters the roles and functions of autophagy in PI. Our results suggest that manipulating apoptosis and autophagy are potential therapeutic targets for treatment and prevention of PI.

Effects of Drink Driving on Crash Risk Based on Random Breath Test Data

Introduction

Driving under the influence of alcohol (DUIA) is an important contributor to road crashes, injuries, and fatalities. Legal limits on drivers' breath alcohol concentration (BrAC) were first introduced in Hong Kong during the 1990s. Since then, the number of alcohol-related crashes has decreased. In 2009, police were empowered to conduct random breath tests (RBT) at roadblocks at any time. The availability of comprehensive RBT data allows us to determine the relationship between crash risk and BrAC, while controlling for confounding factors such as temporal distribution, road environment, and traffic conditions.

Method

In this study, we established two negative binomial regression models to analyse the risk of crashes in which people are killed or seriously injured (KSI crashes) and those involving only slight injuries on 182 urban road segments.

Results

Our results indicated that a higher mean BrAC markedly increases the risk of KSI crashes. However, there was no relationship between the risk of crashes involving slight injury and mean BrAC, although the absence of a hard shoulder, the presence of roadside parking bays, the dawn period, and the location noticeably increase the risk of these crashes.

Conclusion

It is worth exploring the benefits of remedial measures if comprehensive information on demographics and the driving habits of individual drivers become available in the future.

Association between Drink Driving and Severity of Crash Injuries to Road Users

Objective

To determine the association between alcohol impairment in drivers and risk of severe injury in other road users in Hong Kong.

Method

The Road Casualty Injury Information System (RoCIS) was set up by linking a regional hospital injury registry to the police traffic injury database. Based on the year 2004 linked dataset, a specific model namely the External Casualty Model (ECM) was designed to measure the association between severe injury outcome of other (non-driver) road user casualties (as stratified by ISS groups [ISS <9 or ISS ≥9]) and the level of alcohol impairment (as measured by breath alcohol concentration [BAC <22 µg/100 ml or BAC ≥22 µg/100 ml]) in drivers involving in the crash, controlling for the driver's demographics (age and sex) and behaviour (as measured by driving-offence points [DOP]) and another attribute (day of week of crash). Binary logistic regression was used in the analysis.

Results

Out of 1818 matched RoCIS cases in the year 2004, 439 ECM records were available for analysis. Alcohol impaired drivers led to a significantly higher risk of severe injury to other road users (OR=4.2, 95%CI=1.21, 14.36, p=0.02). Crashes on weekdays seemingly led to a lower severe injury risk (OR=0.57, p=0.08) than crashes on weekends. DOP of drivers did not predict a higher severe injury risk to other road users.

Conclusions

Alcohol impairment on driver increases the risk of severe injury to other road users by four times. Road safety education campaign should stress on this adverse impact of drink driving on innocent people.

Bicycle-Related Crashes in Hong Kong: Is it Possible to Reduce Mortality and Severe Injury in the Metropolitan Area?

Background

Cycling is not the primary mode of commuter transport in Hong Kong, yet cyclists are exposed to a high risk of injury and fatality in road crashes. It is essential to identify the significant factors contributing to severe injury among cyclists in Hong Kong.

Aim

To evaluate the effects of significant factors, including demographics, temporal distribution, cyclist behavior, road conditions, and weather, on the risk of severe and life-threatening injury among cyclists in road crashes in Hong Kong.

Method

The study was nested on a database known as Road Casualty Information System (RoCIS) which is a linked database between police traffic accident investigations reports and hospital injury records. A total of 682 victims were identified during the study period from 1 January 2004 to 31 December 2006. In particular, injured body part, demographics, helmet use, alcohol intoxication, weather conditions, road type and geometry, and collision characteristics of 682 trauma patients were the attributing variables of concern. The primary outcome measure was the injury severity of trauma patients which was classified into three levels: slight injury [Injury severity Scale (ISS) </=8], severe injury (ISS >/=9), and life-threatening injury (ISS >/=25). A multinomial logit regression model was established to evaluate the significance of factors contributing to severe and life-threatening injuries among cyclists in road crashes.

Results

The results indicated that middle-aged and elderly (35-54, RRR=2.48; and 55 or above, RRR=4.39) casualties and favourable weather conditions (2.56) significantly increased the risk of severe injury among cyclists. The presence of severe head injury (RRR=509.24), severe trunk injury (RRR=79.24), and the involvement of motor vehicles (RRR=27.18) substantially increased the risk of life-threatening injury to cyclists.

Conclusions

Middle-aged casualties, the presence of head injuries, and the involvement of motor vehicles all increase the risk of more severe injury in bicycle-related crashes. Safety education and countermeasures should target at middle-aged and elderly cyclists and discourage cycling on the motorway.

Protective Effect of Unacylated Ghrelin on Compression-Induced Skeletal Muscle Injury Mediated by SIRT1-Signaling

Unacylated ghrelin, the predominant form of circulating ghrelin, protects myotubes from cell death, which is a known attribute of pressure ulcers. In this study, we investigated whether unacylated ghrelin protects skeletal muscle from pressure-induced deep tissue injury by abolishing necroptosis and apoptosis signaling and whether these effects were mediated by SIRT1 pathway. Fifteen adult Sprague Dawley rats were assigned to receive saline or unacylated ghrelin with or without EX527 (a SIRT1 inhibitor). Animals underwent two 6-h compression cycles with 100 mmHg static pressure applied over the mid-tibialis region of the right limb whereas the left uncompressed limb served as the intra-animal control. Muscle tissues underneath the compression region, and at the similar region of the opposite uncompressed limb, were collected for analysis. Unacylated ghrelin attenuated the compression-induced muscle pathohistological alterations including rounding contour of myofibers, extensive nucleus accumulation in the interstitial space, and increased interstitial space. Unacylated ghrelin abolished the increase in necroptosis proteins including RIP1 and RIP3 and attenuated the elevation of apoptotic proteins including p53, Bax, and AIF in the compressed muscle. Furthermore, unacylated ghrelin opposed the compression-induced phosphorylation and acetylation of p65 subunit of NF-kB. The anti-apoptotic effect of unacylated ghrelin was shown by a decrease in apoptotic DNA fragmentation and terminal dUTP nick-end labeling index in the compressed muscle. The protective effects of unacylated ghrelin vanished when co-treated with EX527. Our findings demonstrated that unacylated ghrelin protected skeletal muscle from compression-induced injury. The myoprotective effects of unacylated ghrelin on pressure-induced tissue injury were associated with SIRT1 signaling.

Occupant-level injury severity analyses for taxis in Hong Kong: A Bayesian space-time logistic model

This study aimed to identify the factors affecting the crash-related severity level of injuries in taxis and quantify the associations between these factors and taxi occupant injury severity. Casualties resulting from taxi crashes from 2004 to 2013 in Hong Kong were divided into four categories: taxi drivers, taxi passengers, private car drivers and private car passengers. To avoid any biased interpretation caused by unobserved spatial and temporal effects, a Bayesian hierarchical logistic modeling approach with conditional autoregressive priors was applied, and four different model forms were tested. For taxi drivers and passengers, the model with space-time interaction was proven to most properly address the unobserved heterogeneity effects. The results indicated that time of week, number of vehicles involved, weather, point of impact and driver age were closely associated with taxi drivers' injury severity level in a crash. For taxi passengers' injury severity an additional factor, taxi service area, was influential. To investigate the differences between taxis and other traffic, similar models were established for private car drivers and passengers. The results revealed that although location in the network and driver gender significantly influenced private car drivers' injury severity, they did not influence taxi drivers' injury severity. Compared with taxi passengers, the injury severity of private car passengers was more sensitive to average speed and whether seat belts were worn. Older drivers, urban taxis and fatigued driving were identified as factors that increased taxi occupant injury severity in Hong Kong.

Checkpoint blockade immunotherapy reshapes the high-dimensional phenotypic heterogeneity of murine intratumoural neoantigen-specific CD8+ T cells

The analysis of neoantigen-specific CD8⁺ T cells in tumour-bearing individuals is challenging due to the small pool of tumour antigen-specific T cells. Here we show that mass cytometry with multiplex combinatorial tetramer staining can identify and characterize neoantigen-specific CD8⁺ T cells in mice bearing T3 methylcholanthrene-induced sarcomas that are susceptible to checkpoint blockade immunotherapy. Among 81 candidate antigens tested, we identify T cells restricted to two known neoantigens simultaneously in tumours, spleens and lymph nodes in tumour-bearing mice. High-dimensional phenotypic profiling reveals that antigen-specific, tumour-infiltrating T cells are highly heterogeneous. We further show that neoantigen-specific T cells display a different phenotypic profile in mice treated with anti-CTLA-4 or anti-PD-1 immunotherapy, whereas their peripheral counterparts are not affected by the treatments. Our results provide insights into the nature of neoantigen-specific T cells and the effects of checkpoint blockade immunotherapy.

Immune checkpoint blockade (ICB) therapies can unleash anti-tumour T-cell responses. Here the authors show, by integrating MHC tetramer multiplexing, mass cytometry and high-dimensional analyses, that neoantigen-specific, tumour-infiltrating T cells are highly heterogeneous and are subjected to ICB modulations.

Skeletal Fragility in Children with Chronic Disease

Skeletal fragility associated with underlying childhood chronic disease is a systemic disorder of poor bone growth and reduction in bone turnover which can lead to abnormal bone mass, geometry and microarchitecture. Due to the growth potential unique to children, remarkable bone recovery following a transient threat to the bone can occur if there is concurrent growth. Addressing bone health in these children should focus on improvement in growth, puberty and removing the primary insult. In conditions where there is a little scope for bone recovery and limited residual growth, bone-targeted therapy may need to be considered, even though there is currently limited evidence. The importance of early detection of signs of bone fragility, by active screening for vertebral fracture using newer imaging techniques such as dual-energy X-ray absorptiometry lateral vertebral morphometry, may now be possible. There is currently, a paucity of evidence to support prophylactic use of anti-resorptive therapy. Where poor growth and low bone turnover are seen, the use of growth-promoting therapies and anabolic bone-protective agents may be more physiological and should be evaluated in well-designed trials. Collaborative studies on long-term fracture outcome and well-designed trials of bone-protective therapies are needed and to be encouraged.

The effect of road network patterns on pedestrian safety: A zone-based Bayesian spatial modeling approach

Pedestrian safety is increasingly recognized as a major public health concern. Extensive safety studies have been conducted to examine the influence of multiple variables on the occurrence of pedestrian-vehicle crashes. However, the explicit relationship between pedestrian safety and road network characteristics remains unknown. This study particularly focused on the role of different road network patterns on the occurrence of crashes involving pedestrians. A global integration index via space syntax was introduced to quantify the topological structures of road networks. The Bayesian Poisson-lognormal (PLN) models with conditional autoregressive (CAR) prior were then developed via three different proximity structures: contiguity, geometry-centroid distance, and road network connectivity. The models were also compared with the PLN counterpart without spatial correlation effects. The analysis was based on a comprehensive crash dataset from 131 selected traffic analysis zones in Hong Kong. The results indicated that higher global integration was associated with more pedestrian-vehicle crashes; the irregular pattern network was proved to be safest in terms of pedestrian crash occurrences, whereas the grid pattern was the least safe; the CAR model with a neighborhood structure based on road network connectivity was found to outperform in model goodness-of-fit, implying the importance of accurately accounting for spatial correlation when modeling spatially aggregated crash data.

A multivariate random-parameters Tobit model for analyzing highway crash rates by injury severity

In this study, a multivariate random-parameters Tobit model is proposed for the analysis of crash rates by injury severity. In the model, both correlation across injury severity and unobserved heterogeneity across road-segment observations are accommodated. The proposed model is compared with a multivariate (fixed-parameters) Tobit model in the Bayesian context, by using a crash dataset collected from the Traffic Information System of Hong Kong. The dataset contains crash, road geometric and traffic information on 224 directional road segments for a five-year period (2002-2006). The multivariate random-parameters Tobit model provides a much better fit than its fixed-parameters counterpart, according to the deviance information criteria and Bayesian R², while it reveals a higher correlation between crash rates at different severity levels. The parameter estimates show that a few risk factors (bus stop, lane changing opportunity and lane width) have heterogeneous effects on crash-injury-severity rates. For the other factors, the variances of their random parameters are insignificant at the 95% credibility level, then the random parameters are set to be fixed across observations. Nevertheless, most of these fixed coefficients are estimated with higher precisions (i.e., smaller variances) in the random-parameters model. Thus, the random-parameters Tobit model, which provides a more comprehensive understanding of the factors' effects on crash rates by injury severity, is superior to the multivariate Tobit model and should be considered a good alternative for traffic safety analysis.

Revisiting crash spatial heterogeneity: A Bayesian spatially varying coefficients approach

This study was performed to investigate the spatially varying relationships between crash frequency and related risk factors. A Bayesian spatially varying coefficients model was elaborately introduced as a methodological alternative to simultaneously account for the unstructured and spatially structured heterogeneity of the regression coefficients in predicting crash frequencies. The proposed method was appealing in that the parameters were modeled via a conditional autoregressive prior distribution, which involved a single set of random effects and a spatial correlation parameter with extreme values corresponding to pure unstructured or pure spatially correlated random effects. A case study using a three-year crash dataset from the Hillsborough County, Florida, was conducted to illustrate the proposed model. Empirical analysis confirmed the presence of both unstructured and spatially correlated variations in the effects of contributory factors on severe crash occurrences. The findings also suggested that ignoring spatially structured heterogeneity may result in biased parameter estimates and incorrect inferences, while assuming the regression coefficients to be spatially clustered only is probably subject to the issue of over-smoothness.

Rule extraction from an optimized neural network for traffic crash frequency modeling

This study develops a neural network (NN) model to explore the nonlinear relationship between crash frequency and risk factors. To eliminate the possibility of over-fitting and to deal with the black-box characteristic, a network structure optimization algorithm and a rule extraction method are proposed. A case study compares the performance of the trained and modified NN models with that of the traditional negative binomial (NB) model for analyzing crash frequency on road segments in Hong Kong. The results indicate that the optimized NNs have somewhat better fitting and predictive performance than the NB models. Moreover, the smaller training/testing errors in the optimized NNs with pruned input and hidden nodes demonstrate the ability of the structure optimization algorithm to identify the insignificant factors and to improve the model generalization capacity. Furthermore, the rule-set extracted from the optimized NN model can reveal the effect of each explanatory variable on the crash frequency under different conditions, and implies the existence of nonlinear relationship between factors and crash frequency. With the structure optimization algorithm and rule extraction method, the modified NN model has great potential for modeling crash frequency, and may be considered as a good alternative for road safety analysis.

Bootstrap resampling approach to disaggregate analysis of road crashes in Hong Kong

Road safety affects health and development worldwide; thus, it is essential to examine the factors that influence crashes and injuries. As the relationships between crashes, crash severity, and possible risk factors can vary depending on the type of collision, we attempt to develop separate prediction models for different crash types (i.e., single- versus multi-vehicle crashes and slight injury versus killed and serious injury crashes). Taking advantage of the availability of crash and traffic data disaggregated by time and space, it is possible to identify the factors that may contribute to crash risks in Hong Kong, including traffic flow, road design, and weather conditions. To remove the effects of excess zeros on prediction performance in a highly disaggregated crash prediction model, a bootstrap resampling method is applied. The results indicate that more accurate and reliable parameter estimates, with reduced standard errors, can be obtained with the use of a bootstrap resampling method. Results revealed that factors including rainfall, geometric design, traffic control, and temporal variations all determined the crash risk and crash severity. This helps to shed light on the development of remedial engineering and traffic management and control measures.

A simulation study of the effects of alcohol on driving performance in a Chinese population

Driving under the influence of alcohol (DUIA) is a significant factor contributing to road traffic crashes, injuries, and fatalities. Although the effects of alcohol on driving performance are widely acknowledged, studies of the effects of alcohol impairment on driving performance and particularly on the control system of Chinese adults are rare. This study attempts to evaluate the effects of alcohol on the driving performance of Chinese adults using a driving simulator.

METHOD

A double-blind experimental study was conducted to evaluate the effects of alcohol impairment on the driving performance of 52 Chinese participants using a driving simulator. A series of simulated driving tests covering two driving modules, including emergency braking (EB) and following braking (FB), at 50km/h and 80km/h were performed. Linear mixed models were established to evaluate driving performance in terms of braking reaction time (BRT), the standard deviation of lateral position (SD-LANE), and the standard deviation of speed (SD-SPEED).

RESULTS

Driving performance in terms of BRT and SD-LANE was highly correlated with the level of alcohol consumption, with a one-unit increase in breath alcohol concentration (BrAC) degrading BRT and SD-LANE by 0.3% and 0.2%, respectively. Frequent drinkers generally reacted faster in their BRT than less-frequent drinkers and non-drinkers by 10.2% and 30.6%, respectively. Moreover, alcohol impairment had varying effects on certain aspects of the human control system, and automatic action was less likely to be affected than voluntary action from a psychological viewpoint.

CONCLUSION

The findings should be useful for planning and developing effective measures to combat drink driving in Chinese communities.

Growth and the Growth Hormone-Insulin Like Growth Factor 1 Axis in Children With Chronic Inflammation: Current Evidence, Gaps in Knowledge, and Future Directions

Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt are often seen during adolescence. The underlying inflammatory state mediated by proinflammatory cytokines, prolonged use of glucocorticoid, and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the GH-IGF axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biological therapy may lead to improvement of growth in some of these children, but approximately one-third continue to grow slowly. There is increasing evidence that the use of relatively high-dose recombinant human GH may lead to partial catch-up growth in chronic inflammatory conditions, although long-term follow-up data are currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis, systemic abnormalities of the GH-IGF axis, and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human GH in these conditions and discussed the role of recombinant human IGF-1.

Temperature- and sex-related effects of serine protease alleles on larval development in the Glanville fritillary butterfly

The body reserves of adult Lepidoptera are accumulated during larval development. In the Glanville fritillary butterfly, larger body size increases female fecundity, but in males fast larval development and early eclosion, rather than large body size, increase mating success and hence fitness. Larval growth rate is highly heritable, but genetic variation associated with larval development is largely unknown. By comparing the Glanville fritillary population living in the Åland Islands in northern Europe with a population in Nantaizi in China, within the source of the post-glacial range expansion, we identified candidate genes with reduced variation in Åland, potentially affected by selection under cooler climatic conditions than in Nantaizi. We conducted an association study of larval growth traits by genotyping the extremes of phenotypic trait distributions for 23 SNPs in 10 genes. Three genes in clip-domain serine protease family were associated with larval growth rate, development time and pupal weight. Additive effects of two SNPs in the prophenoloxidase-activating proteinase-3 (ProPO3) gene, related to melanization, showed elevated growth rate in high temperature but reduced growth rate in moderate temperature. The allelic effects of the vitellin-degrading protease precursor gene on development time were opposite in the two sexes, one genotype being associated with long development time and heavy larvae in females but short development time in males. Sexually antagonistic selection is here evident in spite of sexual size dimorphism.

Effects of fog, driver experience and gender on driving behavior on S-curved road segments

Driving on curved roads has been recognized as a significant safety issue for many years. However, driver behavior and the interactions among variables that affect driver performance on curves is complicated and not well understood. Previous studies have investigated various factors that influence driver performance on right- or left-turn curves, but have paid little attention to the effects of foggy weather, driver experience and gender on driver performance on complex curves. A driving simulator experiment was conducted in this study to evaluate the relationships between driving behavior on a continuous S-curve and foggy weather, driver experience and gender. The process of negotiating a curve was divided into three stages consisting of a straight segment, the transition from the straight segment to the S-curve and the S-curve. The experimental results indicated that drivers tended to drive more cautiously in heavy fog, but the driving risk was still increased, especially in the transition stage from the straight segment to the S-curve. The non-professional (NP) drivers were less sensitive to the impending change in the road geometry, and less skilled in both longitudinal and lateral vehicle control than the professional drivers. The NP female drivers in particular were found to be the most vulnerable group in S-curve driving.

The inflammatory milieu and the insulin like growth factor axis in children with inflammatory bowel disease following recombinant human growth hormone treatment

It is unclear whether recombinant human growth hormone (rhGH) in inflammatory bowel disease (IBD) alters cytokine profile. The objective of this study is to evaluate changes in cytokines and systemic markers of the insulin growth factor axis following 6 months of rhGH treatment in children with IBD. In a six-month randomised control trial in children with IBD treated with rhGH at 0.067 mg/kg/day and controls (11 in each group), we measured pro-, anti-inflammatory cytokines and systemic markers of the IGF axis (total IGF-1, free IGF-1, total IGFBP-3, ALS, IGFBP-2) at baseline (T+0), and six months (T+6). Results expressed as median (range). In the rhGH group, TNFα was 3.1pg/ml (2.9, 100.6) and 3.6pg/ml (3.1, 5.3) at T+0 and T+6, respectively (p=0.85), whereas in the controls this was 3.3pg/ ml (2.7, 4.0) and 3.1pg/m l (2.7, 4.7), respectively (p=0.79). In the rhGH group, IL1β was 18.0pg/ml (5.0,716.7) and 18.0pg/ml (1.7, 52.2) at T+0 and T+6 respectively(p=0.90), whereas in the controls this was 19.8pg/ml (4.1, 27.1) and 19.1pg/ml (2.4,77.3), respectively (p=0.65). None of the twenty-eight other cytokines analysed was different at T+6 in either group. Despite increase in total IGF1 in the rhGH group (p=0.03), free IGF1, IGFBP3, ALS and IGFBP2 did not change in either group at T+6. Percentage change in IGFBP3, was significantly associated with percentage change in IL2 (r=0.77, p=0.009) and IL4 (r=0.58, p=0.01). Percentage change in ALS was significantly associated with percentage change in IL2 (r=0.90, p less than 0.0001) and IL4 (r=0.63, p=0.04). Although changes in markers of the GH/IGF-1 axis do show an association with cytokines (IL-2, IL-4) in pediatric IBD, six months of rhGH treatment was not associated with any significant changes in levels of a range of pro and anti-inflammatory cytokine. Careful evaluation of disease process is required in future trials of rhGH in paediatric IBD.

The likelihood of achieving quantified road safety targets: a binary logistic regression model for possible factors

In past several decades, many countries have set quantified road safety targets to motivate transport authorities to develop systematic road safety strategies and measures and facilitate the achievement of continuous road safety improvement. Studies have been conducted to evaluate the association between the setting of quantified road safety targets and road fatality reduction, in both the short and long run, by comparing road fatalities before and after the implementation of a quantified road safety target. However, not much work has been done to evaluate whether the quantified road safety targets are actually achieved. In this study, we used a binary logistic regression model to examine the factors - including vehicle ownership, fatality rate, and national income, in addition to level of ambition and duration of target - that contribute to a target's success. We analyzed 55 quantified road safety targets set by 29 countries from 1981 to 2009, and the results indicate that targets that are in progress and with lower level of ambitions had a higher likelihood of eventually being achieved. Moreover, possible interaction effects on the association between level of ambition and the likelihood of success are also revealed.

Spatial-temporal analysis of drink-driving patterns in Hong Kong

Normally, bars and restaurants are the preferred locations for drinking. Therefore, there is concern that the roads in bar and restaurant areas could have a higher probability of drink-drivers and alcohol-related road crashes. Many studies have been conducted to model the association between drinking locations and the prevalence of drink-driving, so that cost-effective enforcement strategies can be developed to combat drink-driving. In this study, a cluster analysis approach was applied to model the spatial-temporal variation of drink-driving distribution in Hong Kong. Six spatial-temporal clusters of drink-driving distribution emerged from the data: (i) bar and restaurant area, weekend-overnight; (ii) bar and restaurant area, other timespan; (iii) urban area, weekend-overnight; (iv) urban area, other timespans; (v) rural area, weekend-overnight; and (vi) rural area, other timespans. Next, separate zero-inflated regression models were established to identify the factors contributing to the prevalence of drink-driving for each of the six recognized clusters. The results indicated that drivers in rural areas tend to consume more alcohol than those in urban areas, regardless of the time period. In addition, both seasonal variation and vehicle class were found to determine the breath alcohol concentration (BrAC) levels among drivers.

Emerging resistance in Salmonella enterica serotype Typhi in Hong Kong

A total of 182 Salmonella enterica serotype Typhi isolated from three hospitals in Hong Kong from 1986 to 1992 were tested for their susceptibility to 21 antimicrobial agents. Four percent or less were resistant to chloramphenicol, ampicillin, some of the cephalosporins, nalidixic acid, tetracycline and trimethoprim and 6% to 1024 mg/l sulfamethoxazole. All were susceptible to the aminoglycosides and the 4-quinolones. Nineteen isolates were resistant to at least 1, and up to 9, antibiotics. Of 8 chloramphenicolor multiply-resistant isolates studied, only 3 could transfer their resistances while resistance of one could only be mobilized. Four of 5 ampicillin-resistant strains produced a beta-lactamase of pI 5.5. Antibiotic resistances were mediated by plasmids of 106, 116 or 221 kb of incompatibility groups H, I1 and K. Three resistant isolates did not harbour any plasmid. A total of 43 (24%) S. Typhi harboured plasmids ranging in size from 4.3 to 221 kb. Plasmids of 106 kb and 8.5 kb were found in 17 and 10 isolates, respectively. Restriction enzyme digestion of these two plasmids showed that each could be differentiated into 3 types. Of 89 isolates that were phage typed, 38% were untypable, while 17% and 12% were of phage types E1 and A, respectively, and the rest belonged to 17 other types.

The roles of exposure and speed in road safety analysis

Speed is a determining factor in road safety analysis. It is generally believed that an increase in speed harms road safety. However, it can also be argued that driving at high speed reduces the length of time exposure and thus the likelihood of a crash. It is therefore critical to clarify the roles that exposure and speed play in road safety analysis. This study evaluates the relationship between speed and crash risk with respect to distance and time exposure, using disaggregated crash and speed data collected from 112 road segments in Hong Kong. A joint probability model based on a full Bayesian method is applied simultaneously to model crash occurrence and crash severity. In addition, we consider the explanatory variables, including road design, weather conditions, and temporal distribution, in the proposed crash prediction model. The results indicate that average speed plays a significant role in crash risk, despite opposing correlations with respect to distance and time exposure; the correlation between speed and crash risk is positive when distance exposure is considered, but negative when time exposure is used. However, in both cases, speed is positively associated with the injury severity.