Comparison of Aortobifemoral Bypass and Endovascular Treatment for Chronic Infrarenal Abdominal Aortic Occlusion From the CHAOS (CHronic Abdominal Aortic Occlusion, ASian Multicenter) Registry.

PURPOSE: To directly compare the clinical outcomes of aortobifemoral bypass surgery (ABF) and endovascular treatment (EVT) for chronic total occlusion (CTO) of the infrarenal abdominal aorta (IAA). MATERIALS AND METHODS: In this retrospective, multicenter study, we used an international database of 436 patients who underwent revascularization for CTO of the IAA between 2007 and 2017 at 30 Asian cardiovascular centers. After excluding 52 patients who underwent axillobifemoral bypass surgery, 384 patients (139 ABFs and 245 EVTs) were included in the analysis. Propensity score-matched analysis was performed to compare clinical results in the periprocedural period and the long-term. RESULTS: Propensity score matching extracted 88 pairs. Procedure time (ABF; 288 [240-345] minutes vs EVT; 159 [100-205] minutes, p<0.001) and length of hospital stay (17 [12-23] days vs 5 [4-13] days, p<0.001) were significantly shorter in the EVT group than in the ABF group, while the proportions of procedural success (98.9% versus 96.6%, p=0.620), complications (9.1% versus 12.3%, p=0.550), and mortality (2.3% versus 3.8%, p=1.000) were not different between the groups. At 1 months, ABI significantly increased more in the ABF group for both in a limb with the lower (0.56 versus 0.50, p=0.018) and the higher (0.49 versus 0.34, p=0.001) baseline ABI, while the change of the Rutherford category was not significantly different between the groups (p=0.590). At 5 years, compared with the EVT group, the ABF group had significantly better primary patency (89.4±4.3% versus 74.8±4.3%, p=0.035) and survival rates (86.9±4.5% versus 66.2±7.5%, p=0.007). However, there was no significant difference between the groups for secondary patency (100.0%±0.0% versus 93.5%±3.9%, p=0.160) and freedom from target lesion revascularization (TLR) (89.3±4.3% vs 77.3±7.3%, p=0.096). CONCLUSION: Even with recent advancements in EVT, primary patency was still significantly better for ABF in CTO of the IAA. However, there was no difference between the groups in terms of secondary patency and freedom from TLR at 5 years. Furthermore, there was no difference in procedural success, complications, mortality, and improvement in the Rutherford classification during the periprocedural period, with significantly shorter procedure time and hospital stay in the EVT group.

Fabrication of infrared linear arrays of InAs planar avalanche photodiodes.

We report a, to the best of our knowledge, new device fabrication process for 128-pixel linear arrays of InAs planar avalanche photodiodes, utilizing selective area implantation of Beryllium ions into epitaxially-grown InAs wafers. The pixels exhibited uniform avalanche gain and responsivity. Room temperature responsivity values at 1550 and 2004 nm wavelengths are 0.49 ± 0.017 and 0.89 ± 0.024 A/W, respectively. Reverse dark current-voltage and avalanche gain measurements were carried out at different temperatures (from room temperature to 150 K). At 200 K at -15 V reverse bias, the pixels exhibited an avalanche gain of 22.5 ± 1.18 and dark current density of 0.68 ± 0.48 A/cm2.

Simulation of Al0.85Ga0.15As0.56Sb0.44 avalanche photodiodes.

Al0.85Ga0.15As0.56Sb0.44 is a promising avalanche material for near infrared avalanche photodiodes (APDs) because they exhibit very low excess noise factors. However electric field dependence of ionization coefficients in this material have not been reported. We report a Simple Monte Carlo model for Al0.85Ga0.15As0.56Sb0.44, which was validated using reported experimental results of capacitance-voltage, avalanche multiplication and excess noise factors from five APDs. The model was used to produce effective ionization coefficients and threshold energies between 400-1200 kV.cm-1 at room temperature, which are suitable for use with less complex APD simulation models.

Electron-Scale Reconnection in Three-Dimensional Shock Turbulence.

Magnetic reconnection has been observed in the transition region of quasi-parallel shocks. In this work, the particle-in-cell method is used to simulate three-dimensional reconnection in a quasi-parallel shock. The shock transition region is turbulent, leading to the formation of reconnecting current sheets with various orientations. Two reconnection sites with weak and strong guide fields are studied, and it is shown that reconnection is fast and transient. Reconnection sites are characterized using diagnostics including electron flows and magnetic flux transport. In contrast to two-dimensional simulations, weak guide field reconnection is realized. Furthermore, the current sheets in these events form in a direction almost perpendicular to those found in two-dimensional simulations, where the reconnection geometry is constrained.

Clinician perspectives on a culturally adapted patient decision aid concerning maintenance therapy for asthma.

BACKGROUND AND OBJECTIVE: Patients with persistent asthma often show poor adherence to inhaled corticosteroids (ICS). Shared decision-making can improve adherence rates in this population. Patient decision aids (PDAs) are tools to facilitate shared decision-making. To date, only one PDA, developed in a Canadian French-speaking population, exists for patients considering ICS maintenance therapy. This PDA has been culturally adapted in this study to contextualize to the needs of multi-ethnic Asian patients in Singapore. This study explored the views of local clinicians on the content, design and implementation of this newly-adapted PDA. METHODS: 24 clinicians, who were purposively sampled from polyclinics and a tertiary institution, were interviewed on the content, design and implementation of the PDA. The interviews were audio-recorded, transcribed and analyzed via thematic analysis. RESULTS: Clinicians generally accepted the design of the PDA. They suggested for the target users to be patients on Step 2 of GINA guidelines and the number of options to be reduced from four to two (do nothing or start inhaled corticosteroids). Moreover, they supported including a list of values for patients to select from given that Asian patients often do not articulate their values readily. The addition of more visual aids, the production of multilingual Asian editions and the involvement of nurses to administer the PDA was also suggested. CONCLUSION: The PDA was culturally-adapted with local clinicians' perspectives to target multi-ethnic Asian patients with persistent asthma (Step 2 GINA guidelines). The main changes include a list of values and addition of visual aids.

Single-cell RNA sequencing identifies molecular targets associated with poor in vitro maturation performance of oocytes collected from ovarian stimulation.

STUDY QUESTION: What is the transcriptome signature associated with poor performance of rescue IVM (rIVM) oocytes and how can we rejuvenate them? SUMMARY ANSWER: The GATA-1/CREB1/WNT signalling axis was repressed in rIVM oocytes, particularly those of poor quality; restoration of this axis may produce more usable rIVM oocytes. WHAT IS KNOWN ALREADY: rIVM aims to produce mature oocytes (MII) for IVF through IVM of immature oocytes collected from stimulated ovaries. It is not popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress and the absence of cumulus cell support in oocytes could account for the failure of rIVM. STUDY DESIGN, SIZE, DURATION: We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo oocytes (IVO) (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors. The effects of maternal age and ovarian responses on rIVM oocyte transcriptomes were also studied. In parallel, we studied the effect of gallic acid on the maturation rate of mouse oocytes cultured in IVM medium with (n = 84) and without (n = 85) gallic acid. PARTICIPANTS/MATERIALS, SETTING, METHODS: Human oocytes were collected from donors aged 28-41 years with a body mass index of <30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analysed. Selected genes in the rIVM versus IVO comparison were validated by quantitative real-time PCR. For the gallic acid study, we collected immature oocytes from 5-month-old mice and studied the effect of 10-µM gallic acid on their maturation rate. MAIN RESULTS AND THE ROLE OF CHANCE: The transcriptome profiles of rIVM/IVO oocytes showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least 2-fold change and adjusted P < 0.05) were found to be enriched in metabolic processes, biosynthesis and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/ß-catenin signalling in rIVM when compared with IVO oocytes. We found that oestradiol levels exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio) for each donor. rIVM oocytes from women with a high MII ratio were found to have over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor clinical outcomes of rIVM, we compared oocytes collected from young donors with a high MII ratio with oocytes from donors of advanced maternal age and lower MII ratio, and revealed that CREB1 is an important regulator. Thus, our study identified that GATA-1/CREB1/WNT signalling was repressed in both rIVM oocytes versus IVO oocytes and in rIVM oocytes of lower versus higher quality. Consequently we investigated gallic acid, as a potential antioxidant substrate in human rIVM medium, and found that it increased the mouse oocyte maturation rate by 31.1%. LARGE SCALE DATA: Raw data from this study can be accessed through GSE158539. LIMITATIONS, REASONS FOR CAUTION: In the rIVM oocytes of the high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle, so polar body extrusion was the only indicator. WIDER IMPLICATIONS OF THE FINDINGS: This study showed that GATA-1/CREB1/WNT signalling was repressed in rIVM oocytes compared with IVO oocytes and was further downregulated in low-quality rIVM oocytes, providing us the foundation of subsequent follow-up research on human oocytes and raising safety concerns about the clinical use of rescued oocytes. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Collaborative Research Fund, Research Grants Council, C4054-16G, and Research Committee Funding (Research Sustainability of Major RGC Funding Schemes), The Chinese University of Hong Kong. The authors have no conflicts of interest to declare.

Autosomal recessive hypotrichosis with loose anagen hairs associated with TKFC mutations.

BACKGROUND: Loose anagen hair is a rare form of impaired hair anchorage in which anagen hairs that lack inner and outer root sheaths can be gently and painlessly plucked from the scalp. This condition usually occurs in children and is often self-limiting. A genetic basis for the disorder has been suggested but not proven. A better understanding the aetiology of loose anagen hair may improve prevention and treatment strategies. OBJECTIVES: To identify a possible genetic basis of loose anagen hair using next-generation DNA sequencing and functional analysis of variants identified. METHODS: In this case study, whole-exome sequencing analysis of a pedigree with one affected individual with features of loose anagen hair was performed. RESULTS: The patient was found to be compound heterozygous for two single-nucleotide substitutions in TKFC resulting in the following missense mutations: c.574G> C (p.Gly192Arg) and c.682C> T (p.Arg228Trp). Structural analysis of human TKFC showed that both mutations are located near the active site cavity. Kinetic assays of recombinant proteins bearing either of these amino acid substitutions showed almost no dihydroxyacetone kinase or D-glyceraldehyde kinase activity, and FMN cyclase activity reduced to just 10% of wildtype catalytic activity. CONCLUSIONS: TKFC missense mutations may predispose to the development of loose anagen hairs. Identification of this new biochemical pathobiology expands the metabolic and genetic basis of hypotrichosis.

Recombinant turnip yellow mosaic virus coat protein as a potential nanocarrier.

AIMS: To display a short peptide (GSRSHHHHHH) at the C-terminal end of turnip yellow mosaic virus coat protein (TYMVc) and to study its assembly into virus-like particles (TYMVcHis6 VLPs). METHODS AND RESULTS: In this study, recombinant TYMVcHis6 expressed in Escherichia coli self-assembled into VLPs of approximately 30-32 nm. SDS-PAGE and Western blot analysis of protein fractions from the immobilized metal affinity chromatography (IMAC) showed that TYMVcHis6 VLPs interacted strongly with nickel ligands in IMAC column, suggesting that the fusion peptide is protruding out from the surface of VLPs. These VLPs are highly stable over a wide pH range from 3·0 to 11·0 at different temperatures. At pH 11·0, specifically, the VLPs remained intact up to 75°C. Additionally, the disassembly and reassembly of TYMVcHis6 VLPs were studied in vitro. Dynamic light scattering and transmission electron microscopy analysis revealed that TYMVcHis6 VLPs were dissociated by 7 mol l-1 urea and 2 mol l-1 guanidine hydrochloride (GdnHCl) without impairing their reassembly property. CONCLUSIONS: A 10-residue peptide was successfully displayed on the surface of TYMVcHis6 VLPs. This chimera demonstrated high stability under extreme thermal conditions with varying pH and was able to dissociate and reassociate into VLPs by chemical denaturants. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first C-terminally modified TYMVc produced in E. coli. The C-terminal tail which is exposed on the surface can be exploited as a useful site to display multiple copies of functional ligands. The ability of the chimeric VLPs to self-assemble after undergo chemical denaturation indicates its potential role to serve as a nanocarrier for use in targeted drug delivery.

Effects of enhanced recovery after surgery practices on postoperative recovery and length of stay after unilateral primary total hip or knee arthroplasty in a private hospital.

INTRODUCTION: Enhanced recovery after surgery (ERAS) practices improve postoperative recovery and reduce postoperative length of stay (LOS) in patients undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). Our study investigated whether these promising results could be reproduced in a private hospital setting. METHODS: In total, 228 patients were included in the study cohort: the conventional group comprised 117 patients from 2012 to 2014, while the ERAS group comprised 111 patients from 2017 to 2018. All patients had undergone unilateral primary THA or TKA at a private hospital in Hong Kong. The outcome was postoperative LOS; factors affecting LOS were also investigated. RESULTS: No significant differences were found in any baseline parameters between the two groups of patients. The mean LOS was significantly shorter in the ERAS group than in the conventional group (3.28 ± 1.04 vs 5.16 ± 2.06 days, P<0.001). Moreover, a significantly greater proportion of patients could be discharged on or before postoperative day 3 in the ERAS group, compared with the conventional group (77.5% vs 13.7%, P<0.001). A significant difference in LOS was observed between general ward and private ward patients (3.06 ± 0.59 vs 3.66 ± 1.46 days, P=0.003). Sex, age, and nature of surgery (TKA vs THA) did not have significant effects on LOS. CONCLUSIONS: The ERAS practices yielded a significant improvement in postoperative LOS, compared to conventional practices, among patients who underwent unilateral primary THA or TKA in a private hospital.

Lower-Hybrid Drift Waves Driving Electron Nongyrotropic Heating and Vortical Flows in a Magnetic Reconnection Layer.

We report measurements of lower-hybrid drift waves driving electron heating and vortical flows in an electron-scale reconnection layer under a guide field. Electrons accelerated by the electrostatic potential of the waves exhibit perpendicular and nongyrotropic heating. The vortical flows generate magnetic field perturbations comparable to the guide field magnitude. The measurements reveal a new regime of electron-wave interaction and how this interaction modifies the electron dynamics in the reconnection layer.

The effect of collisions on the rotational angular momentum of diatomic molecules studied using polarized light.

We report results of an experimental study of the changes in the alignment of the rotational angular momentum of diatomic molecules during elastic collisions. The experiment involved collisions of diatomic lithium molecules in the A1Σu + excited electronic state with noble gas atoms (helium and argon) in a thermal gas phase sample. Polarized light for excitation was combined with the detection of polarization-specific fluorescence in order to achieve magnetic sublevel state selectivity. We also report results for rotationally inelastic collisions of Li2 in the lowest lying rotational levels of the A1Σu +v=5 vibrational state with noble gas atoms.

Postoperative analgesic efficacy of modified continuous transversus abdominis plane block in laparoscopic colorectal surgery: a triple-blind randomized controlled trial.

BACKGROUND: The optimal opioid-sparing analgesic regimen following laparoscopic colorectal surgery (LCS) remains uncertain. We sought to determine the efficacy of low-dose bupivacaine infusion via surgeon-inserted modified continuous transversus abdominis plane (mcTAP) catheters after LCS. METHODS: A parallel-group, placebo-controlled, randomized single-centre trial was conducted between April 2017 and February 2018. Block-of-four randomization and allocation concealment by sequentially-numbered, opaque sealed envelopes were used. Patients, surgeons and assessors were blinded. Fifty-two patients were randomized to receive either 0.2% bupivacaine or saline through mcTAP catheters. A 5 ml bolus followed by a 72 h infusion at 2 ml/h was started, with patient-controlled fentanyl analgesia and oral paracetamol given on demand. Primary outcomes were fentanyl consumptions in the first 24 h, second 24 h, and third 24 h following surgery. Secondary outcomes were pain numeric rating scores, recovery outcomes and complications. RESULTS: Twenty-five patients in the bupivacaine group and 26 in the control group were analysed. Patients in the bupivacaine group required significantly less fentanyl overall (106.1 vs 484.5 mcg, p < 0.001) and at all time points (first 24 h: 61.0 vs 324.3 mcg, p < 0.001; second 24 h: 36.3 vs 119.0 mcg, p = 0.033; third 24 h: 8.8 vs 41.2, p = 0.030) when compared to placebo. Significantly lower pain scores at rest at 6 h (2.32 vs 4.0, p = 0.002), and 12 h (1.80 vs 3.08, p = 0.011) and on coughing at 6 h (4.56 vs 5.84, p = 0.019), 12 h (3.76 vs 4.96, p = 0.009), and 24 h (3.44 vs 4.24, p = 0.049) as well as significantly lower opioid-related complications such as nausea or vomiting (9 (36%) vs 1 (4%), p = 0.005) were observed in the bupivacaine group. There were no major block-related complications, and recovery outcomes were similar in both groups. CONCLUSIONS: McTAP block reduces postoperative fentanyl consumption and pain scores after LCS, highlighting its role as a safe and useful opioid-sparing analgesia. REGISTRATION NUMBER: TCTR20150831001 (Thai Clinical Trials Registry). Full trial protocol can be assessed at https://www.clinicaltrials.in.th/ .

Performance improvement of wastewater treatment processes by application of machine learning.

Improving wastewater treatment processes is becoming increasingly important, due to more stringent effluent quality requirements, the need to reduce energy consumption and chemical dosing. This can be achieved by applying artificial intelligence. Machine learning is implemented in two domains: (1) predictive control and (2) advanced analytics. This is currently being piloted at the integrated validation plant of PUB, Singapore's National Water Agency. (1) Primarily, predictive control is applied for optimised nutrient removal. This is obtained by application of a self-learning feedforward algorithm, which uses load prediction and machine learning, fine-tuned with feedback on ammonium effluent. Operational results with predictive control show that the load prediction has an accuracy of ≈88%. It is also shown that an up to ≈15% reduction of aeration amount is achieved compared to conventional control. It is proven that this load prediction-based control leads to stable operation and meeting effluent quality requirements as an autopilot system. (2) Additionally, advanced analytics are being developed for operational support. This is obtained by application of quantile regression neural network modelling for anomaly detection. Preliminary results illustrate the ability to autodetect process and instrument anomalies. These can be used as early warnings to deliver data-driven operational support to process operators.

Pressure Tensor Elements Breaking the Frozen-In Law During Reconnection in Earth's Magnetotail.

Aided by fully kinetic simulations, spacecraft observations of magnetic reconnection in Earth's magnetotail are analyzed. The structure of the electron diffusion region is in quantitative agreement with the numerical model. Of special interest, the spacecraft data reveal how reconnection is mediated by off-diagonal stress in the electron pressure tensor breaking the frozen-in law of the electron fluid.

Dedicated peri-operative pathway improved day case discharge rate for anterior cruciate ligament reconstructions.

The authors proposed that a well-developed peri-operative pathway for anterior cruciate ligament (ACL) reconstructions improve day case discharge rate with high patient satisfaction. A prospective observational study was undertaken at a district general hospital in UK between August 2017 and April 2018. A dedicated multidisciplinary peri-operative pathway was developed and introduced in January 2018. All primary ACL reconstructions using hamstring grafts in adult patients were included. Primary outcome measure was day case discharge and secondary outcome measures were visual analogue score for pain (VASP), nausea and vomiting scale (NVS), patient satisfaction and 30-day readmission. Patients who underwent surgery before and after introduction of the pathway were in group 1 and group 2, respectively. There were 19 and 22 patients each in group 1 and 2. Age and gender were similar in both groups. Day case discharge rate was significantly better in group 2 (68.4% vs 95.5%, p = 0.02). There were no significant differences in VASP or NVS on day 0, 1 or 3. Patient satisfaction rates were better in group 2 (85.7% vs 100%, p = 0.13). There were no readmissions in both groups. The VASP on day 1 and day 3 post-operatively was significantly better in those who were discharged on the same day (66.8 vs 41.3, p = 0.02; 60.5 vs 34.9, p = 0.03). A well-developed dedicated peri-operative pathway improved day case discharge rate for ACL reconstructions. The pathway was safe and had a higher patient satisfaction rate.

Spectrum of movement disorders and neurotransmitter abnormalities in paediatric POLG disease.

OBJECTIVES: To describe the spectrum of movement disorders and cerebrospinal fluid (CSF) neurotransmitter profiles in paediatric patients with POLG disease. METHODS: We identified children with genetically confirmed POLG disease, in whom CSF neurotransmitter analysis had been undertaken. Clinical data were collected retrospectively. CSF neurotransmitter levels were compared to both standardised age-related reference ranges and to non-POLG patients presenting with status epilepticus. RESULTS: Forty-one patients with POLG disease were identified. Almost 50% of the patients had documented evidence of a movement disorder, including non-epileptic myoclonus, choreoathetosis and ataxia. CSF neurotransmitter analysis was undertaken in 15 cases and abnormalities were seen in the majority (87%) of cases tested. In many patients, distinctive patterns were evident, including raised neopterin, homovanillic acid and 5-hydroxyindoleacetic acid levels. CONCLUSIONS: Children with POLG mutations can manifest with a wide spectrum of abnormal movements, which are often prominent features of the clinical syndrome. Underlying pathophysiology is probably multifactorial, and aberrant monoamine metabolism is likely to play a role.

Correction to: Spectrum of movement disorders and neurotransmitter abnormalities in paediatric POLG disease.

Due to a typesetting error the wrong Table 2 was used. The correct Table 2 is shown here.

Is there benefit to continue magnesium sulphate postpartum in women receiving magnesium sulphate before delivery? A randomised controlled study.

OBJECTIVE: To determine if the use of magnesium sulphate postdelivery reduces the risk of eclampsia in women with severe pre-eclampsia exposed to at least 8 hours of magnesium sulphate before delivery. DESIGN: Randomised multicentre controlled trial. SETTING: Latin America. POPULATION: Women with severe pre-eclampsia that had received a 4-g loading dose followed by 1 g per hour for 8 hours as maintenance dose before delivery. METHODS: In all, 1113 women were randomised; 555 women were randomised to continue the infusion of magnesium sulphate for 24 hours postpartum and 558 were randomised to stopping the magnesium sulphate infusion immediately after delivery. OUTCOME MEASURES: Primary outcome was the incidence of eclampsia in the first 24 hours postdelivery. Secondary outcomes included maternal death, maternal complications, time to start ambulation and time to start lactation. RESULTS: The maternal characteristics at randomisation between the groups were not different. There were no differences in the rate of eclampsia; 1/555 (0.18%) versus 2/558 (0.35%) [relative risk (RR 0.7, 95% CI 0.1-3.3; P = 0.50] or maternal complications between the groups (RR 1.0, 95% CI 0.8-1.2; P = 0.76). Time to start ambulation was significantly shorter in the no magnesium sulphate group (18.1 ± 10.6 versus 11.8 ± 10.8 hours; P = 0.0001) and time to start lactation was equally shorter in the no magnesium sulphate group (24.1 ± 17.1 versus 17.1 ± 16.8 hours; P = 0.0001). CONCLUSIONS: Women with severe pre-eclampsia treated with a minimum of 8 hours of magnesium sulphate before delivery do not benefit from continuing the magnesium sulphate for 24 hours postpartum. TWEETABLE ABSTRACT: No benefit of continuing magnesium sulphate postpartum in severe pre-eclampsia exposed to this drug for a minimum of 8 hours before delivery.

Two case reports of zoledronic acid-induced uveitis.

Zoledronic acid (zoledronate) is a bisphosphonate used predominantly as a second-line treatment for post-menopausal osteoporosis. Its administration is associated with an acute phase reaction. Here, we present two cases of anterior uveitis following initial administration of zoledronate. In the first case, an 80-year-old lady presented with right eye pain and decreased visual acuity 24-hours post-infusion. Uveitis was diagnosed and sub-conjunctival injection of corticosteroids was required. In the second case, a 78-year-old lady presented with right eye pain, vomiting and decreased acuity 24-hours after infusion. She was treated with topical steroids and required cataract surgery to normalise visual acuity. Patients prescribed zoledronate should be warned of the risk of ocular side effects and asked to report promptly for treatment if they develop a red, painful eye or blurred vision.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong.

INTRODUCTION: Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM. METHODS: The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling. RESULTS: In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years. CONCLUSION: The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.