MyMedR

Fulltext The role of human Metapneumovirus genetic diversity and nasopharyngeal viral load on symptom severity in adults

Oong XY, Chook JB, Ng KT, Chow WZ, Chan KG, Hanafi NS, et al.

Virol J, 2018 05 23;15(1):91.

PMID: 29792212 DOI: 10.1186/s12985-018-1005-8

BACKGROUND: Human metapneumovirus (HMPV) is established as one of the causative agents of respiratory tract infections. To date, there are limited reports that describe the effect of HMPV genotypes and/or viral load on disease pathogenesis in adults. This study aims to determine the role of HMPV genetic diversity and nasopharyngeal viral load on symptom severity in outpatient adults with acute respiratory tract infections.
METHODS: Severity of common cold symptoms of patients from a teaching hospital was assessed by a four-category scale and summed to obtain the total symptom severity score (TSSS). Association between the fusion and glycoprotein genes diversity, viral load (quantified using an improved RT-qPCR assay), and symptom severity were analyzed using bivariate and linear regression analyses.
RESULTS: Among 81/3706 HMPV-positive patients, there were no significant differences in terms of demographics, number of days elapsed between symptom onset and clinic visit, respiratory symptoms manifestation and severity between different HMPV genotypes/sub-lineages. Surprisingly, elderly patients (≥65 years old) had lower severity of symptoms (indicated by TSSS) than young and middle age adults (p = 0.008). Nasopharyngeal viral load did not correlate with nor predict symptom severity of HMPV infection. Interestingly, at 3-5 days after symptom onset, genotype A-infected patients had higher viral load compared to genotype B (4.4 vs. 3.3 log10 RNA copies/μl) (p = 0.003).
CONCLUSIONS: Overall, HMPV genetic diversity and viral load did not impact symptom severity in adults with acute respiratory tract infections. Differences in viral load dynamics over time between genotypes may have important implications on viral transmission.
Study site: Primary Care Clinic, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

Fulltext Epidemiological and Evolutionary Dynamics of Influenza B Viruses in Malaysia, 2012-2014

Oong XY, Ng KT, Lam TT, Pang YK, Chan KG, Hanafi NS, et al.

PLoS One, 2015;10(8):e0136254.

PMID: 26313754 DOI: 10.1371/journal.pone.0136254

Epidemiological and evolutionary dynamics of influenza B Victoria and Yamagata lineages remained poorly understood in the tropical Southeast Asia region, despite causing seasonal outbreaks worldwide. From 2012-2014, nasopharyngeal swab samples collected from outpatients experiencing acute upper respiratory tract infection symptoms in Kuala Lumpur, Malaysia, were screened for influenza viruses using a multiplex RT-PCR assay. Among 2,010/3,935 (51.1%) patients infected with at least one respiratory virus, 287 (14.3%) and 183 (9.1%) samples were tested positive for influenza A and B viruses, respectively. Influenza-positive cases correlate significantly with meteorological factors-total amount of rainfall, relative humidity, number of rain days, ground temperature and particulate matter (PM10). Phylogenetic reconstruction of haemagglutinin (HA) gene from 168 influenza B viruses grouped them into Yamagata Clade 3 (65, 38.7%), Yamagata Clade 2 (48, 28.6%) and Victoria Clade 1 (55, 32.7%). With neuraminidase (NA) phylogeny, 30 intra-clade (29 within Yamagata Clade 3, 1 within Victoria Clade 1) and 1 inter-clade (Yamagata Clade 2-HA/Yamagata Clade 3-NA) reassortants were identified. Study of virus temporal dynamics revealed a lineage shift from Victoria to Yamagata (2012-2013), and a clade shift from Yamagata Clade 2 to Clade 3 (2013-2014). Yamagata Clade 3 predominating in 2014 consisted of intra-clade reassortants that were closely related to a recent WHO vaccine candidate strain (B/Phuket/3073/2013), with the reassortment event occurred approximately 2 years ago based on Bayesian molecular clock estimation. Malaysian Victoria Clade 1 viruses carried H274Y substitution in the active site of neuraminidase, which confers resistance to oseltamivir. Statistical analyses on clinical and demographic data showed Yamagata-infected patients were older and more likely to experience headache while Victoria-infected patients were more likely to experience nasal congestion and sore throat. This study describes the evolution of influenza B viruses in Malaysia and highlights the importance of continuous surveillance for better vaccination policy in this region.

Fulltext Draft Genome Sequence of Mycobacterium massiliense Strain M159, Showing Phenotypic Resistance to β-Lactam and Tetracycline Antibiotics

Ngeow YF, Leong ML, Wong YL, Wong GJ, Tan JL, Wee WY, et al.

Genome Announc, 2013;1(4).

PMID: 23990576 DOI: 10.1128/genomeA.00669-13

Mycobacterium massiliense is a nontuberculous mycobacterium associated with human infections. We report here the draft genome sequence of M. massiliense strain M159, isolated from the bronchial aspirate of a patient who had a pulmonary infection. This strain showed genotypic and in vitro resistance to a number of tetracyclines and beta-lactam antibiotics.

Fulltext Outbreaks of enterovirus D68 in Malaysia: genetic relatedness to the recent US outbreak strains

Ng KT, Oong XY, Pang YK, Hanafi NS, Kamarulzaman A, Tee KK

Emerg Microbes Infect, 2015 Aug;4(8):e47.

PMID: 26421270 DOI: 10.1038/emi.2015.47

Fulltext Performance of a Taqman Assay for Improved Detection and Quantification of Human Rhinovirus Viral Load

Ng KT, Chook JB, Oong XY, Chan YF, Chan KG, Hanafi NS, et al.

Sci Rep, 2016 10 10;6:34855.

PMID: 27721388 DOI: 10.1038/srep34855

Human rhinovirus (HRV) is the major aetiology of respiratory tract infections. HRV viral load assays are available but limitations that affect accurate quantification exist. We developed a one-step Taqman assay using oligonucleotides designed based on a comprehensive list of global HRV sequences. The new oligonucleotides targeting the 5'-UTR region showed high PCR efficiency (E = 99.6%, R2 = 0.996), with quantifiable viral load as low as 2 viral copies/μl. Assay evaluation using an External Quality Assessment (EQA) panel yielded a detection rate of 90%. When tested on 315 human enterovirus-positive specimens comprising at least 84 genetically distinct HRV types/serotypes (determined by the VP4/VP2 gene phylogenetic analysis), the assay detected all HRV species and types, as well as other non-polio enteroviruses. A commercial quantification kit, which failed to detect any of the EQA specimens, produced a detection rate of 13.3% (42/315) among the clinical specimens. Using the improved assay, we showed that HRV sheds in the upper respiratory tract for more than a week following acute infection. We also showed that HRV-C had a significantly higher viral load at 2-7 days after the onset of symptoms (p = 0.001). The availability of such assay is important to facilitate disease management, antiviral development, and infection control.

Viral Load and Sequence Analysis Reveal the Symptom Severity, Diversity, and Transmission Clusters of Rhinovirus Infections

Ng KT, Oong XY, Lim SH, Chook JB, Takebe Y, Chan YF, et al.

Clin Infect Dis, 2018 07 02;67(2):261-268.

PMID: 29385423 DOI: 10.1093/cid/ciy063

Background: Rhinovirus (RV) is one of the main viral etiologic agents of acute respiratory illnesses. Despite the heightened disease burden caused by RV, the viral factors that increase the severity of RV infection, the transmission pattern, and seasonality of RV infections remain unclear.

Methods: An observational study was conducted among 3935 patients presenting with acute upper respiratory illnesses in the ambulatory settings between 2012 and 2014.

Results: The VP4/VP2 gene was genotyped from all 976 RV-positive specimens, where the predominance of RV-A (49%) was observed, followed by RV-C (38%) and RV-B (13%). A significant regression in median nasopharyngeal viral load (VL) (P < .001) was observed, from 883 viral copies/µL at 1-2 days after symptom onset to 312 viral copies/µL at 3-4 days and 158 viral copies/µL at 5-7 days, before declining to 35 viral copies/µL at ≥8 days. In comparison with RV-A (median VL, 217 copies/µL) and RV-B (median VL, 275 copies/µL), RV-C-infected subjects produced higher VL (505 copies/µL; P < .001). Importantly, higher RV VL (median, 348 copies/µL) was associated with more severe respiratory symptoms (Total Symptom Severity Score ≥17, P = .017). A total of 83 phylogenetic-based transmission clusters were identified in the population. It was observed that the relative humidity was the strongest environmental predictor of RV seasonality in the tropical climate.

Conclusions: Our findings underline the role of VL in increasing disease severity attributed to RV-C infection, and unravel the factors that fuel the population transmission dynamics of RV.

Fulltext EGFR mutations in Asian patients with advanced lung adenocarcinoma

Liam CK, Pang YK, Poh ME

J Thorac Oncol, 2014 Sep;9(9):e70-1.

PMID: 25122441 DOI: 10.1097/JTO.0000000000000251

Fulltext Satisfaction level and asthma control among Malaysian asthma patients on Symbicort Maintenance and Reliever Therapy (SMART) in the primary care setting (SMARTEST study)

Liam CK, Pang YK, Chua KT

Asian Pac J Allergy Immunol, 2014 Jun;32(2):145-52.

PMID: 25003728 DOI: 10.12932/AP0359.32.2.2013

OBJECTIVE: To evaluate Malaysian patients' satisfaction levels and asthma control with Symbicort SMART® in the primary care setting.
METHOD: This is a cross-sectional, multicentre study involving adult patients with persistent asthma who were prescribed only Symbicort SMART in the preceding one month prior to recruitment. Patients' satisfaction with Symbicort SMART and asthma control were evaluated using the self-administered Satisfaction with Asthma Treatment Questionnaire (SATQ) and the Asthma Control Test (ACT).
RESULTS: Asthma was controlled (ACT score >20) in 189 (83%) of 228 patients. The mean overall SATQ score for patients with controlled asthma was 5.65 indicating a high satisfaction level, which was positively correlated with high ACT scores. There were differences in asthma control based on ethnicity, number of unscheduled visits and treatment compliance.
CONCLUSIONS: Symbicort SMART resulted in a high satisfaction level and asthma control among Malaysian patients treated in the primary care setting and it is an effective and appealing treatment for asthmatic patients.
Study site: General practice clinics, Malaysia

Fulltext EGFR mutation testing for squamous cell lung carcinoma

Liam CK, Leow HR, Pang YK

J Thorac Oncol, 2013 Dec;8(12):e114.

PMID: 24389448 DOI: 10.1097/JTO.0b013e3182a4e111

Epidermal growth factor receptor mutations in non- small cell lung cancers in a multiethnic malaysian patient population

Liam CK, Leow HR, How SH, Pang YK, Chua KT, Lim BK, et al.

Asian Pac J Cancer Prev, 2014;15(1):321-6.

PMID: 24528049

BACKGROUND: Mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) in non- small cell lung cancer (NSCLC) are predictive of response to EGFR-targeted therapy in advanced stages of disease. This study aimed to determine the frequency of EGFR mutations in NSCLCs and to correlate their presence with clinical characteristics in multiethnic Malaysian patients.

MATERIALS AND METHODS: In this prospective study, EGFR mutations in exons 18, 19, 20 and 21 in formalin-fixed paraffin-embedded biopsy specimens of consecutive NSCLC patients were asessed by real-time polymerase chain reaction.

RESULTS: EGFR mutations were detected in NSCLCs from 55 (36.4%) of a total of 151 patients, being significantly more common in females (62.5%) than in males (17.2%) [odds ratio (OR), 8.00; 95% confidence interval (CI), 3.77-16.98; p<0.001] and in never smokers (62.5%) than in ever smokers (12.7%) (OR, 11.50; 95%CI, 5.08-26.03; p<0.001). Mutations were more common in adenocarcinoma (39.4%) compared to non-adenocarcinoma NSCLCs (15.8%) (p=0.072). The mutation rates in patients of different ethnicities were not significantly different (p=0.08). Never smoking status was the only clinical feature that independently predicted the presence of EGFR mutations (adjusted OR, 5.94; 95%CI, 1.94- 18.17; p=0.002).

CONCLUSIONS: In Malaysian patients with NSCLC, the EGFR mutation rate was similar to that in other Asian populations. EGFR mutations were significantly more common in female patients and in never smokers. Never smoking status was the only independent predictor for the presence of EGFR mutations.

Fulltext Lung adenocarcinoma with ipsilateral pleural and breast metastases

Liam CK, Pang YK, Kow KS

J Thorac Oncol, 2014 Jan;9(1):e8-9.

PMID: 24346108 DOI: 10.1097/01.JTO.0000438376.45132.9c

Fulltext Advanced right lung adenocarcinoma with ipsilateral breast metastasis

Liam CK, Pang YK, Poh ME, Kow KS, Wong CK, Varughese R

Respirol Case Rep, 2013 Sep;1(1):20-2.

PMID: 25473531 DOI: 10.1002/rcr2.14

Breast metastases from non-small cell lung carcinoma are rarely reported. We report a case of a female patient with primary adenocarcinoma of the lower lobe of her right lung presenting with a massive right-sided malignant pleural effusion. The tumor harbored an epidermal growth factor receptor insertion mutation in exon 20 but was anaplastic lymphoma kinase translocation negative. She did not respond to treatment with erlotinib. First- and second-line cytotoxic chemotherapy resulted in stable disease as the best responses. She developed right breast metastasis 20 months after her initial presentation. The rarity of the condition and the likely mechanism of the breast metastasis are discussed.

Outcomes of Malaysian patients with advanced lung adenocarcinoma and unknown epidermal growth factor receptor mutation status treated with gefitinib

Liam CK, Ruthranesan M, Lee CH, Pang YK, Chua KT, Lim BK

Asia Pac J Clin Oncol, 2012 Sep;8(3):267-74.

PMID: 22897510 DOI: 10.1111/j.1743-7563.2011.01509.x

To evaluate the response and progression-free survival (PFS) of Malaysian patients with advanced lung adenocarcinoma and unknown epidermal growth factor receptor (EGFR) mutation status treated with gefitinib.

Fulltext Obstructed breathing during sleep and obstructive sleep apnoea syndrome--assessment and treatment

Liam CK, Pang YK, Shyamala P, Chua KT

Med J Malaysia, 2007 Aug;62(3):268-73; quiz 274.

PMID: 18246927

During normal sleep the tone of the pharyngeal airway dilator muscles is decreased resulting in upper airway narrowing and increased resistance to airflow. Nasal obstruction may result from a variety of anatomical abnormalities such as septal deviation, nasal polyps, adenoid hypertrophy and rhinitis such as allergic rhinitis, acute viral rhinitis, vasomotor rhinitis and non-allergic rhinitis with nasal eosinophilia syndrome. Disordered breathing during sleep can both result from and be worsened by nasal obstruction. In children, nasal obstruction due to enlarged tonsils and adenoids results in a switch to oral breathing which may lead to the adenoid faces because of changes in the craniofacial structures during growth that predispose to disordered breathing during sleep.

Changes in the distribution of lung cancer cell types and patient demography in a developing multiracial Asian country: experience of a university teaching hospital

Liam CK, Pang YK, Leow CH, Poosparajah S, Menon A

Lung Cancer, 2006 Jul;53(1):23-30.

PMID: 16690159

A comparison of patients with lung cancer diagnosed at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia from October 1991 to September 1999 with another group of lung cancer patients diagnosed at the same hospital during an earlier period of 1967-1976 was undertaken to determine whether there had been a change in the distribution of lung cancer cell types and patient demography. The number of histologically and/or cytologically proven lung cancer cases was 583 from October 1991 to September 1999 and 278 from 1967 to 1976. The mean (S.D.) age of the patients during the period 1991-1999, 60.1 (12.0) years was similar to that of patients during the period 1967-1976, 60.3 (12.2) years. There was no shift of the peak age distribution of lung cancer (i.e., the 7th decade) between the two periods. In the recent period, the percentage of patients with adenocarcinoma had increased significantly to 43.2% from 25.2% while that of large cell carcinoma had decreased to 3.3% from 11.9%. The percentages of patients with squamous cell carcinoma (SCC) and small cell lung cancer remained stable. In the period 1967-1976, SCC was the commonest cell type in men and in smokers while adenocarcinoma was the commonest cell type in women and in never smokers. In the period 1991-1999, adenocarcinoma was the commonest cell type in both men and women as well as in smokers and never smokers.

Epidermal growth factor receptor targeted therapy with gefitinib in locally advanced and metastatic primary lung adenocarcinoma

Liam CK, Pang YK, Leow CH

Respirology, 2006 May;11(3):287-91.

PMID: 16635086

To describe the efficacy of monotherapy with the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib in patients with locally advanced and metastatic primary lung adenocarcinoma.

Pulmonary tuberculosis presenting as community-acquired pneumonia

Liam CK, Pang YK, Poosparajah S

Respirology, 2006 Nov;11(6):786-92.

PMID: 17052309

The aims of this study were to investigate the frequency of Mycobacterium tuberculosis as a cause of community-acquired pneumonia (CAP) requiring hospitalization in Malaysia, and to define the clinical features of pulmonary tuberculosis (PTB) that distinguish it from non-TB CAP.

Fulltext Diagnostic yield of flexible bronchoscopic procedures in lung cancer patients according to tumour location

Liam CK, Pang YK, Poosparajah S

Singapore Med J, 2007 Jul;48(7):625-31.

PMID: 17609823

This study aims to determine whether the diagnostic yield of flexible bronchoscopy sampling procedures in patients with lung cancer was dependent on tumour location.

Fulltext Common driver mutations and programmed death-ligand 1 expression in advanced non-small cell lung cancer in smokers and never smokers

Liam CK, Yew CY, Pang YK, Wong CK, Poh ME, Tan JL, et al.

BMC Cancer, 2023 Jul 14;23(1):659.

PMID: 37452277 DOI: 10.1186/s12885-023-11156-y

BACKGROUND: In non-small cell lung cancer (NSCLC), there may be a relationship between programmed death-ligand 1 (PD-L1) expression, driver mutations and cigarette smoking.

METHODS: In this single-center retrospective study, the relationship between common driver mutations (EGFR mutation and ALK rearrangement) and PD-L1 expression in advanced NSCLC according to the patients' smoking history was examined. Light, moderate and heavy smokers had smoked

Fulltext Barriers to implementing asthma self-management in Malaysian primary care: qualitative study exploring the perspectives of healthcare professionals

Lee PY, Cheong AT, Ghazali SS, Salim H, Wong J, Hussein N, et al.

NPJ Prim Care Respir Med, 2021 07 07;31(1):38.

PMID: 34234145 DOI: 10.1038/s41533-021-00250-y

Asthma self-management is a crucial component of asthma management. We sought to explore healthcare professionals' (HCPs') perceptions on barriers to asthma self-management implementation in primary care. We recruited 26 HCPs from six public primary care clinics in a semi-urban district of Malaysia in 2019. The analysis was done inductively. HCPs described barriers that resonated with the "COM-B" behaviour change framework. Capability-related issues stemmed from a need for specific self-management skills training. Opportunity-related barriers included the need to balance competing tasks and limited, poorly tailored resources. Motivation-related barriers included lack of awareness about self-management benefits, which was not prioritised in consultations with perceived lack of receptiveness from patients. These were compounded by contextual barriers of the healthcare organisation and multilingual society. The approach to implementation of asthma self-management needs to be comprehensive, addressing systemic, professional, and patient barriers and tailored to the local language, health literacy, and societal context.

Displaying publications 21 - 40 of 63 in total