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The effect of motion and signalling on drivers' ability to predict intentions of other road users

Lee YM, Sheppard E

Accid Anal Prev, 2016 Oct;95(Pt A):202-8.
PMID: 27450792 DOI: 10.1016/j.aap.2016.07.011

Failure in making the correct judgment about the intention of an approaching vehicle at a junction could lead to a collision. This paper investigated the impact of dynamic information on drivers' judgments about the intentions of approaching cars and motorcycles, and whether a valid or invalid signal was provided was also manipulated. Participants were presented with videoclips of vehicles approaching a junction which terminated immediately before the vehicle made any manoeuvre, or images of the final frame of each video. They were asked to judge whether or not the vehicle would turn. Drivers were better in judging the manoeuvre of approaching vehicles in dynamic than static stimuli, for both vehicle types. Drivers were better in judging the manoeuvre of cars than motorcycles for videos, but not for photographs. Drivers were also better in judging the manoeuvre of approaching vehicles when a valid signal was provided than an invalid signal, demonstrating the importance of providing a valid signal while driving. However, drivers were still somewhat successful in their judgments in most of the conditions with an invalid signal, suggesting that drivers were able to focus on other cues to intention. Finally, given that dynamic stimuli more closely reflect the demands of real-life driving there may be a need for drivers to adopt a more cautious approach while inferring a motorcyclist's intentions.
Fulltext The effect of lighting conditions and use of headlights on drivers' perception and appraisal of approaching vehicles at junctions

Lee YM, Sheppard E

Ergonomics, 2018 Mar;61(3):444-455.
PMID: 28782425 DOI: 10.1080/00140139.2017.1364790

Use of Daytime Running Lights (DRL) is mandatory in many countries for motorcycles, and in some for cars. However, in developing countries, DRLs may be optional or compliance low. The effect of car or motorcycle headlights and lighting conditions on Malaysian drivers' ability to perceive and judge the safety of pulling out was investigated. Stimuli were photographs depicting either daytime or nighttime taken at a T-junction with approaching vehicles with headlights on or off. Headlights improved drivers' ability to perceive cars and motorcycles in the nighttime photographs but not the daytime photographs, although this could be due to the bright weather in the photographs. Drivers judged it less safe to pull out when approaching motorcycles had headlights on than off, regardless of the lighting conditions, supporting the utility of DRL for motorcycles. Headlights did not affect judgements for cars, questioning the utility of DRL for cars. Practitioner Summary: The effect of headlights and lighting conditions on drivers' ability to perceive and make judgements about the safety of pulling out was investigated. Daytime Running Lights influenced drivers' decision-making about the safety of pulling out in front of motorcycles, illustrating the importance of having automatic headlights equipped.
Fulltext Suxamethonium and cardiac arrest

Lee YM, Fountain SW

Singapore Med J, 1997 Jul;38(7):300-1.
PMID: 9339098

We report a case of cardiac arrest due to hyperkalaemia following administration of suxamethonium during a procedure to facilitate a change of endotracheal tube in a septic patient. The cause of this rare but fatal complication is briefly described and discussed. In view of this, suxamethonium should be used with great caution in patients with burns and other forms of physical injury, in a number of nervous system disorders, and in critically ill patients requiring prolonged ITU care.
Fulltext Hyperplasia of thymic gland

Lee YM, Koh MT, Omar A, Majid A

Singapore Med J, 1996 Jun;37(3):288-90.
PMID: 8942232

Hyperplasia of the thymus is the most common anterior mediastinal mass in infants. It is however exceedingly difficult to evaluate by the weight of the gland as it continues to grow after birth until puberty and thereafter undergoes progressive atrophy. It normally maintains most of the radiographic characteristics of the normal thymus. Massive thymic hyperplasia, a rare variant of true thymic hyperplasia is extremely rare during the first two decades of life and clinically can cause mediastinal compression or acute and recurrent pulmonary infection. Two such cases are reported and the clinico-pathology is briefly described and discussed.
Fulltext Video-assisted thoracoscopic surgery for pneumothorax

Lee YM, Lim YC, Liam CK, Aljafri M

Med J Malaysia, 1995 Dec;50(4):334-8.
PMID: 8668053

Five cases of spontaneous pneumothorax were treated with video-assisted thoracoscopic surgery (VATS). These included four cases of recurrent pneumothorax and one case of persistent pneumothorax. The mean age was 33 years. The identified bullae were eliminated with either endoloop ligation (in one patient) or stapled excision (in four patients). There were no recurrences reported in a mean follow-up of 9.4 months. In conclusion, VATS offers an equally effective and less morbid alternative to open thoracotomy in the management of primary spontaneous pneumothorax.
Fulltext Early experience of video-assisted thoracoscopic surgery

Lee YM, Lim YC, Liam CK, Majid A

Med J Malaysia, 1996 Mar;51(1):109-13.
PMID: 10967989

Consecutive 25 patients (M/F:18/7) underwent video-assisted thoracoscopic surgery (VATS) for various chest illnesses. These included nine cases of pneumothorax, three cases of pericardial effusion, three cases of pleural effusion, four cases of lung lesion requiring either incisional or excisional biopsy, two cases of empyema, one case of traumatic haemothorax, and three cases of mediastinal lesion. The mean age was 36.2 years (range 19-78 years). A total of forty-three procedures were performed. The mean durations of intrapleural chest-tube requirement and hospitalisation following VATS alone were 4.5 days (range: 0-13 days) and 8.3 days (range: 2-25 days) respectively. No intraoperative complication and VATS procedure-related mortality reported. Apart from simple analgesics such as paracetamol or tramadolol, no opiate analgesia was given to patients undergoing only VATS. The results support that VATS is a safe and effective procedure in the management of pulmonary, mediastinal, pericardial and pleural diseases and the treatment of persistent and recurrent spontaneous pneumothorax.
Genome sequences of a novel HIV-1 CRF53_01B identified in Malaysia

Chow WZ, Al-Darraji H, Lee YM, Takebe Y, Kamarulzaman A, Tee KK

J Virol, 2012 Oct;86(20):11398-9.
PMID: 22997419

A novel HIV-1 genotype designated CRF53_01B was recently characterized from three epidemiologically unrelated persons in Malaysia. Here we announced three recently isolated full-length genomes of CRF53_01B, which is likely to be phylogenetically linked to CRF33_01B, circulating widely in Southeast Asia. The genome sequences may contribute to HIV-1 molecular surveillance and future vaccine development in the region.
Fulltext Virological investigation of four outbreaks of influenza B reassortants in the northern region of Taiwan from October 2006 to February 2007

Lee YM, Wang SF, Lee CM, Chen KH, Chan YJ, Liu WT, et al.

BMC Res Notes, 2009;2:86.
PMID: 19426542 DOI: 10.1186/1756-0500-2-86

From October 2006 to February 2007, clinical specimens from 452 patients with symptoms related to respiratory tract infection in the northern region of Taiwan were collected. Real-time PCR and direct immunofluorescent antibody tests showed that 145 (32%) patients had influenza B virus infections. Subsequently, nucleotide sequence analyses of both hemagglutinin (HA) and neuraminidase (NA) genes of 39 isolates were performed. Isolated viruses were antigenically characterized using hemagglutinin inhibition (HI) test.
Racial differences in the prevalence of ulcerative colitis and Crohn's disease in Singapore

Lee YM, Fock K, See SJ, Ng TM, Khor C, Teo EK

J Gastroenterol Hepatol, 2000 Jun;15(6):622-5.
PMID: 10921415

BACKGROUND: The aim of this study was to determine the prevalence rates of inflammatory bowel disease in the different races in Singapore.
METHODS: The patients studied consisted of 58 people with an established diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) as determined by a combination of clinical, radiological, endoscopic and histological criteria. The patients were residents of a well-defined geographical area in the northern part of Singapore and had been referred to the single regional hospital. Epidemiological data including sex, age, ethnicity, family history and disease type and extent were collected from case records and patient interviews.
RESULTS: There were 37 UC and 21 CD patients. Of the patients with UC, 67.5% were Chinese, 13.5% were Malay and 19% were Indian. The CD group consisted of 81% Chinese, 9.5% Malay and 9.5% Indian patients. The study population from which the patients were drawn was approximately 0.5 million in size.
CONCLUSIONS: The overall prevalence of UC was 6 per 100,000 and of CD was 3.6 per 100,000 in Singapore. There were disproportionately more Indians suffering from UC, with a prevalence of 16.2 per 100,000 in comparison with six per 100,000 for Chinese and seven per 100 000 for Malays. The relative risk of UC in Indians is 2.9-fold greater than for the Chinese (CI= 1.25-6.7) which was statistically significant. This trend was not seen for CD.
Molecular diversity of HIV-1 and surveillance of transmitted drug resistance variants among treatment Naïve patients, 5 years after active introduction of HAART in Kuala Lumpur, Malaysia

Ong LY, Razak SN, Lee YM, Sri La Sri Ponnampalavanar S, Syed Omar SF, Azwa RI, et al.

J Med Virol, 2014 Jan;86(1):38-44.
PMID: 24127302 DOI: 10.1002/jmv.23772

Expansion of antiretroviral treatment programs have led to the growing concern for the development of antiretroviral drug resistance. The aims were to assess the prevalence of drug resistant HIV-1 variants and to identify circulating subtypes among HAART-naïve patients. Plasma specimens from N = 100 HIV+ HAART-naïve adult were collected between March 2008 and August 2010 and viral RNA were extracted for nested PCR and sequenced. PR-RT sequences were protein aligned and checked for transmitted drug resistance mutations. Phylogenetic reconstruction and recombination analysis were performed to determine the genotypes. Based on the WHO consensus guidelines, none of the recruited patients had any transmitted drug resistance mutations. When analyzed against the Stanford guidelines, 35% of patients had at least one reported mutation that may reduce drug susceptibility to PI (24%), NRTI (5%), and NNRTI (14%). The commonly detected mutation that may affect current first line therapy was V179D (3%), which may lead to reduced susceptibility to NNRTI. The predominant circulating HIV-1 genotypes were CRF01_AE (51%) and CRF33_01B (17%). The prevalence of unique recombinant forms (URF) was 7%; five distinct recombinant structures involving CRF01_AE and subtype B' were observed, among them a cluster of three isolates that could form a novel circulating recombinant form (CRF) candidate. Transmitted drug resistance prevalence among HAART-naïve patients was low in this cohort of patients in Kuala Lumpur despite introduction of HAART 5 years ago. Owing to the high genetic diversity, continued molecular surveillance can identify the persistent emergence of HIV-1 URF and novel CRF with significant epidemiological impact.
Complete Genome Sequences of Three Historically Important, Spatiotemporally Distinct, and Genetically Divergent Strains of Zika Virus: MR-766, P6-740, and PRVABC-59

Yun SI, Song BH, Frank JC, Julander JG, Polejaeva IA, Davies CJ, et al.

Genome Announc, 2016;4(4).
PMID: 27540058 DOI: 10.1128/genomeA.00800-16

Here, we report the 10,807-nucleotide-long consensus RNA genome sequences of three spatiotemporally distinct and genetically divergent Zika virus strains, with the functionality of their genomic sequences substantiated by reverse genetics: MR-766 (African lineage, Uganda, 1947), P6-740 (Asian lineage, Malaysia, 1966), and PRVABC-59 (Asian lineage-derived American strain, Puerto Rico, 2015).
Fulltext Functional Genomics and Immunologic Tools: The Impact of Viral and Host Genetic Variations on the Outcome of Zika Virus Infection

Yun SI, Song BH, Frank JC, Julander JG, Olsen AL, Polejaeva IA, et al.

Viruses, 2018 08 11;10(8).
PMID: 30103523 DOI: 10.3390/v10080422

Zika virus (ZIKV) causes no-to-mild symptoms or severe neurological disorders. To investigate the importance of viral and host genetic variations in determining ZIKV infection outcomes, we created three full-length infectious cDNA clones as bacterial artificial chromosomes for each of three spatiotemporally distinct and genetically divergent ZIKVs: MR-766 (Uganda, 1947), P6-740 (Malaysia, 1966), and PRVABC-59 (Puerto Rico, 2015). Using the three molecularly cloned ZIKVs, together with 13 ZIKV region-specific polyclonal antibodies covering nearly the entire viral protein-coding region, we made three conceptual advances: (i) We created a comprehensive genome-wide portrait of ZIKV gene products and their related species, with several previously undescribed gene products identified in the case of all three molecularly cloned ZIKVs. (ii) We found that ZIKV has a broad cell tropism in vitro, being capable of establishing productive infection in 16 of 17 animal cell lines from 12 different species, although its growth kinetics varied depending on both the specific virus strain and host cell line. More importantly, we identified one ZIKV-non-susceptible bovine cell line that has a block in viral entry but fully supports the subsequent post-entry steps. (iii) We showed that in mice, the three molecularly cloned ZIKVs differ in their neuropathogenicity, depending on the particular combination of viral and host genetic backgrounds, as well as in the presence or absence of type I/II interferon signaling. Overall, our findings demonstrate the impact of viral and host genetic variations on the replication kinetics and neuropathogenicity of ZIKV and provide multiple avenues for developing and testing medical countermeasures against ZIKV.
Fulltext Genome sequence of the hepatitis C virus subtype 6n isolated from malaysia

Ng KT, Lee YM, Al-Darraji HA, Xia X, Takebe Y, Chan KG, et al.

Genome Announc, 2013 Jan;1(1).
PMID: 23409272 DOI: 10.1128/genomeA.00168-12

We report the full genome sequence of hepatitis C virus (HCV) subtype 6n from Kuala Lumpur, Malaysia. Phylogenetic analysis of the isolate 10MYKJ032 suggests that Southeast Asia might be the origin for the HCV subtype 6n and highlights the possible spread of this lineage from Southeast Asia to other regions.
Fulltext Molecular diversity of HIV-1 among people who inject drugs in Kuala Lumpur, Malaysia: massive expansion of circulating recombinant form (CRF) 33_01B and emergence of multiple unique recombinant clusters

Chow WZ, Ong LY, Razak SH, Lee YM, Ng KT, Yong YK, et al.

PLoS One, 2013;8(5):e62560.
PMID: 23667490 DOI: 10.1371/journal.pone.0062560

Since the discovery of HIV-1 circulating recombinant form (CRF) 33_01B in Malaysia in the early 2000 s, continuous genetic diversification and active recombination involving CRF33_01B and other circulating genotypes in the region including CRF01_AE and subtype B' of Thai origin, have led to the emergence of novel CRFs and unique recombinant forms. The history and magnitude of CRF33_01B transmission among various risk groups including people who inject drugs (PWID) however have not been investigated despite the high epidemiological impact of CRF33_01B in the region. We update the most recent molecular epidemiology of HIV-1 among PWIDs recruited in Malaysia between 2010 and 2011 by population sequencing and phylogenetic analysis of 128 gag-pol sequences. HIV-1 CRF33_01B was circulating among 71% of PWIDs whilst a lower prevalence of other previously dominant HIV-1 genotypes [subtype B' (11%) and CRF01_AE (5%)] and CRF01_AE/B' unique recombinants (13%) were detected, indicating a significant shift in genotype replacement in this population. Three clusters of CRF01_AE/B' recombinants displaying divergent yet phylogenetically-related mosaic genomes to CRF33_01B were identified and characterized, suggestive of an abrupt emergence of multiple novel CRF clades. Using rigorous maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC) sampling of CRF33_01Bpol sequences to elucidate the past population dynamics, we found that the founder lineages of CRF33_01B were likely to have first emerged among PWIDs in the early 1990 s before spreading exponentially to various high and low-risk populations (including children who acquired infections from their mothers) and later on became endemic around the early 2000 s. Taken together, our findings provide notable genetic evidence indicating the widespread expansion of CRF33_01B among PWIDs and into the general population. The emergence of numerous previously unknown recombinant clades highlights the escalating genetic complexity of HIV-1 in the Southeast Asian region.
Fulltext Boceprevir early-access for advanced-fibrosis/cirrhosis in Asia-Pacific hepatitis C virus genotype 1 non-responders/relapsers

Sukeepaisarnjaroen W, Pham T, Tanwandee T, Nazareth S, Galhenage S, Mollison L, et al.

World J Gastroenterol, 2015 Jul 28;21(28):8660-9.
PMID: 26229408 DOI: 10.3748/wjg.v21.i28.8660

To examined the efficacy and safety of treatment with boceprevir, PEGylated-interferon and ribavirin (PR) in hepatitis C virus genotype 1 (HCVGT1) PR treatment-failures in Asia.
Findings from a large Asian chronic hepatitis C real-life study

Lim SG, Phyo WW, Shah SR, Win KM, Hamid S, Piratvisuth T, et al.

J Viral Hepat, 2018 12;25(12):1533-1542.
PMID: 30141214 DOI: 10.1111/jvh.12989

There is a paucity of information on chronic hepatitis C (CHC) patients treated with direct antiviral agents (DAAs) in Asia. We invited Asia-Pacific physicians to collate databases of patients enrolled for CHC treatment, recording baseline clinical, virologic and biochemical characteristics, sustained virologic response at week 12 (SVR12) and virologic failure. SVR12 outcome was based on intention to treat (ITT). Multivariate analysis was used to assess independent risk factors for SVR12 using SPSS version 20. A total of 2171 patients from India (n = 977), Myanmar (n = 552), Pakistan (n = 406), Thailand (n = 139), Singapore (n = 72) and Malaysia (n = 25) were collected. At baseline, mean age was 49 years, 50.2% were males, and 41.8% had cirrhosis. Overall, SVR12 was 89.5% and by genotype (GT) based on ITT and treatment completion, respectively, was 91% and 92% for GT1, 100% and 100% for GT2, 91% and 97% for GT3, 64% and 95% for GT4, 87% and 87% for GT6 and 79% and 91% for GT untested. Patients with cirrhosis had SVR12 of 85% vs 93% for noncirrhosis (P < 0.001) (RR 2.1, 95% CI 1.4-3.1, P = 0.0002). Patients with GT1 and GT3 treated with sofosbuvir/ribavirin (SR) had 88% and 89% SVR12, respectively, but those GT6 treated with sofosbuvir/ledipasvir (SL) had only 77.6% SVR12. Multivariate analysis showed absence of cirrhosis was associated with higher SVR12 (OR 2.0, 95% CI 1.3-3.1, P = 0.002). In conclusion, patients with GT1 and GT3 with/without cirrhosis had surprisingly high efficacy using SR, suggesting that Asians may respond better to some DAAs. However, poor GT6 response to SL suggests this regimen is suboptimal for this genotype.

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