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Illustrated larval key to lepidopteran pests of rice in Malaysia

Nur AM, Nur AA, Lau WH

Zootaxa, 2015;3986(2):243-8.
PMID: 26250185 DOI: 10.11646/zootaxa.3986.2.8

Here we provide an illustrated key to lepidopteran larvae that occur as pests on rice (Oryza) in Malaysia. We are unaware of a published key for this region for this vital commercial crop, and hence provide one based on easily observable features that could be useful for identification, early detection, and pest management by specialists and non-specialists alike (see discussion in Mukerji & Singh 1951, Sri et al. 2010, Timm et al. 2007, Tillmon et al. 2000, Wagener et al. 2004).
A review on polyamide thin film nanocomposite (TFN) membranes: History, applications, challenges and approaches

Lau WJ, Gray S, Matsuura T, Emadzadeh D, Chen JP, Ismail AF

Water Res, 2015 Sep 1;80:306-24.
PMID: 26011136 DOI: 10.1016/j.watres.2015.04.037

This review focuses on the development of polyamide (PA) thin film nanocomposite (TFN) membranes for various aqueous media-based separation processes such as nanofiltration, reverse osmosis and forward osmosis since the concept of TFN was introduced in year 2007. Although the total number of published TFN articles falls far short of the articles of the well-known thin film composite (TFC) membranes, its growth rate is significant, particularly since 2012. Generally, by incorporating an appropriate amount of nanofiller into a thin selective PA layer of a composite membrane, one could produce TFN membranes with enhanced separation characteristics as compared to the conventional TFC membrane. For certain cases, the resulting TFN membranes demonstrate not only excellent antifouling resistance and/or greater antibacterial effect, but also possibly overcome the trade-off effect between water permeability and solute selectivity. Furthermore, this review attempts to give the readers insights into the difficulties of incorporating inorganic nanomaterials into the organic PA layer whose thickness usually falls in a range of several-hundred nanometers. It is also intended to show new possible approaches to overcome these challenges in TFN membrane fabrication.
Fulltext Awake respiratory function in patients with the obstructive sleep apnoea syndrome

Liam CK, Lim KH, Wong CMM, Lau WM, Tan CT

Med J Malaysia, 2001 Mar;56(1):10-7.
PMID: 11503285

Introduction: The flow-volume curves of patients with obstructive sleep apnoea (OSA) obtained during the awake state are frequently abnormal.
Objective: To determine 1) the relationship between the awake respiratory function and the severity of sleep-disordered breathing in a group of Malaysian patients with the OSA syndrome and 2) the frequency of flow-volume curve abnormality in these patients.
Materials and methods: A retrospective analysis of the data from respiratory function tests during wakefulness and nocturnal polysomnography was performed on 48 patients with OSA. The severity of OSA was defined by the apnoea-hypopnoea index (AHI) and the lowest oxygen saturation during sleep (SPO2nadir).
Results: AHI had a significant relationship with alveolar-arterial oxygen gradient (r=0.34, p=0.046) and SPO2nadir (r=0.049, p<0.001) but not with any anthropometric parameter or the other awake respiratory function variables measured SPO2nadir, has a significant relationship with body mass index (r=0.54, P<0.001), neck circumference (r=-0.39, p=0.013), awake room air PaO2 (r=0.61, p<0.001), alveolar-arterial oxygen gradient (r=-0.41, p=0.015) and baseline supine SpO2 (r=0.53, p<0.001). there was no correlation between SPO2nadir and any spirometric or static lung volume parameters. The maximum inspiratory and maximum expiratory flow volume curves of 26 patients (54%) showed a ratio of forced expiratory flow to forced inspiratory flow at mid-vital capacity (FEF50/FIF50) greater than one. In addition, flow oscillations (the ‘sawtooth’ sign) were noted in the inspiratory and/or expiratory flow-volume curves of 21 patients (44%), 9 of who did not have an FEF50/FIF50>1. Altogether, the maximum flow-volume curves during wakefulness of 35 (&3%) of the 48 patients showed variable upper airway obstruction and/or flow oscillations. However, the presence of these two upper airway abnormalities, either occurring alone or together did not have an effect on the severity of OSA as measured by the AHI or SPO2nadir.
Conclusions: Abnormalities of the flow-volume loop consistent with inspiratory flow limitation and/or upper airway instability during wakefulness are common in patients with the OSA syndrome. The degree of oxygen desaturation during sleep in these patients as related to their awake oxygenation status.
Fulltext Acute renal failure following jering ingestion

H'ng PK, Nayar SK, Lau WM, Segasothy M

Singapore Med J, 1991 Apr;32(2):148-9.
PMID: 2042077

We report two cases of acute renal failure that followed the ingestion of jering. Features of jering poisoning included clinical presentation of bilateral loin pain, fever, nausea, vomiting, oligo-anuria, haematuria and passage of sandy particles in the urine. Blood urea (40.8 mmol/l; 21.9 mmol/l) and serum creatinine (1249 mumols/l; 693 mumols/l) were markedly elevated. With conservative therapy which included rehydration with normal saline and alkalinisation of the urine with sodium bicarbonate, the acute renal failure resolved.
Preparation and characterization of a novel highly hydrophilic and antifouling polysulfone/nanoporous TiO2 nanocomposite membrane

Bidsorkhi HC, Riazi H, Emadzadeh D, Ghanbari M, Matsuura T, Lau WJ, et al.

Nanotechnology, 2016 Oct 14;27(41):415706.
PMID: 27607307 DOI: 10.1088/0957-4484/27/41/415706

In this research, novel ultrafiltration nanocomposite membranes were prepared by incorporating self-synthesized nanoporous titanium dioxide (NTiO2) nanoparticles into polysulfone. The surface of the nanoparticle was treated with a silane-based modifier to improve its distribution in the host polymer. Atomic-force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, transmission electron microscopy, energy-dispersive x-ray spectroscopy, porosity and contact angle tests were conducted to characterize the properties of the particles as well as the fabricated nanocomposite membranes. The effects of the nanoparticle incorporation were evaluated by conducting ultrafiltration experiments. It was reported that the membrane pure water flux was increased with increasing NTiO2 loading owing to the high porosity of the nanoparticles embedded and/or formation of enlarged pores upon addition of them. The antifouling capacity of the membranes was also tested by ultrafiltration of bovine serum albumin fouling solution. It was found that both water flux and antifouling capacity tended to reach desired level if the NTiO2 added was at optimized loading.
Surface modification of thin film composite membrane by nanoporous titanate nanoparticles for improving combined organic and inorganic antifouling properties

Emadzadeh D, Ghanbari M, Lau WJ, Rahbari-Sisakht M, Rana D, Matsuura T, et al.

Mater Sci Eng C Mater Biol Appl, 2017 Jun 01;75:463-470.
PMID: 28415486 DOI: 10.1016/j.msec.2017.02.079

In this study, nanoporous titanate (NT) nanoparticle synthesized by the solvothermal method was used to modify polyamide layer of thin film composite membranes with the aim of improving membrane resistances against organic and inorganic fouling. Thin film nanocomposite membranes (NMs) were synthesized by adding mNTs (modified nanoparticles) into polyamide selective layer followed by characterization using different analytical instruments. The results of XPS and XRD confirmed the presence of mNTs in the polyamide layer of NMs, while FESEM, AFM, zeta potential and contact angle measurement further supported the changes in physical and chemical properties of the membrane surface upon mNTs incorporation. Results of fouling showed that NM1 (the membrane incorporated with 0.01w/v% mNTs) always demonstrated lower degree of flux decline compared to the control membrane when membranes were tested with organic, inorganic and multicomponent synthesized water, brackish water or seawater. Besides showing greater antifouling resistance, the NM also displayed significantly higher water flux compared to the control M membrane. The findings of this work confirmed the positive impact of mNTs in improving the properties of NM with respect to fouling mitigation and flux improvement.
A Case of Severe Falciparum Malaria in a Returned Traveler

Low QJ, Lau WK, Lim TH, Lee RA, Cheo SW

Malays Fam Physician, 2020;15(3):86-89.
PMID: 33329868

Primary care providers should be alert to travel-related infections. Around 10-40% of returning travelers from all destinations and 15-70% of travelers from tropical settings experience ill health, either overseas or upon returning home.1 A systematic approach concentrating on possible infections should be undertaken based on the patient's travel location, immunization history, presence of malaria chemoprophylaxis at the destination, other potential exposures, incubation period, and clinical presentation.2-3 The World Health Organization (WHO) website is constantly being updated on specific travel-related infections and recent geographical outbreaks. In this paper, we report a case of severe falciparum malaria in a returned traveler.
Fulltext Vibration-assisted forward osmosis process for Mao (Antidesma bunius L. Spreng) juice concentration: water flux enhancement and preservation of phytochemicals

Sirinupong, T., Tirawat, D., Lau, W. J., Youravong, W.

International Food Research Journal, 2020;27(6):1156-1166.
MyJurnal

The experimental water flux of the forward osmosis (FO) process is much lower than the
theoretical flux due to the existence of the internal concentration polarisation (ICP), external
concentration polarisation (ECP), and membrane fouling. In the present work, vibration was
integrated with the FO process to enhance water flux in water and Mao (Antidesma bunius L.
Spreng) juice concentration. In addition, the capability of the FO process in preserving
phytochemicals was studied. The use of the vibration assisted technique could enhance the
water flux up to 23% during the FO process of distilled water due to the reduction of ICP, and
a much higher water flux enhancement (up to 70%) was attained during the FO of Mao juice
due to the reduction of ICP, ECP, and fouling. Phytochemicals including total phenolic
compounds, anthocyanin, and ascorbic acid were preserved up to 82.7, 72.6, and 95.9%,
respectively. These results suggest that membrane vibration is a promising technique for the
enhancement of the FO process performance.
Clinically important detection of infection as an 'incidental' finding during cancer staging using FDG-PET/CT

Wong PS, Lau WF, Worth LJ, Thursky KA, Drummond E, Slavin MA, et al.

Intern Med J, 2012 Feb;42(2):176-83.
PMID: 21309995 DOI: 10.1111/j.1445-5994.2011.02450.x

BACKGROUND:
FDG-PET/CT is widely used in the management of a variety of malignancies with excellent overall accuracy, despite the potential for false positive results related to infection and inflammation.

AIM:
As cancer patients can develop clinically inapparent infections, we evaluated the prevalence and nature of incidental findings reported to be suggestive of infections that had been identified during clinical cancer staging with FDG-PET/CT.

METHODS:
The study involved a retrospective analysis of 60 patients managed primarily at our facility from a total of 121 cases identified as having possible infection on clinical reporting of more than 4500 cancer staging investigations performed during the calendar year of 2008.

RESULTS:
Occult infections were uncommon overall (≤1%), but most often because of pneumonia (31.6%), upper respiratory tract infections (21.1%) or wound infections (15.8%). Abnormal scans contributed to patients' management in 52.7% of cases. Two out of 13 patients whose scan abnormalities were not investigated further had worsening changes on repeated scan and one of these patients had clinical deterioration.

CONCLUSIONS:
In patients with FDG-PET/CT scans suggestive of infection and in whom a final diagnosis could be reached, the positive predictive value for FDG-PET/CT scans was 89% suggesting that abnormal scans indicative of infection should be investigated further in this population.
18[F]FDG-PET/CT is a useful molecular marker in evaluating tumour aggressiveness: a revised understanding of an in-vivo FDG-PET imaging that alludes the alteration of cancer biology

Fathinul F, Nordin AJ, Lau WF

Cell Biochem Biophys, 2013 May;66(1):37-43.
PMID: 22790883 DOI: 10.1007/s12013-012-9395-5

Molecular imaging employing (18)[F]FDG-PET/CT enables in-vivo visualization, characterisation and measurement of biological process in tumour at the molecular and cellular level. In oncology, this approach can be directly applied as translational biomarkers of disease progression. In this article, the improved roles of FDG as an in-vivo glycolytic marker which reflect biological changes across in-vitro cellular environment are discussed. New understanding in how altered metabolism via glycolytic downstream drivers of malignant transformation as reviewed below offers unique promise as to monitor tumour aggressiveness and hence optimize the therapeutic management.
Fulltext An intense F-FDG pulmonary microfocus on PET without detectable abnormality on CT: A manifestation of an iatrogenic FDG pulmonary embolus

Fathinul Fikri A, Lau W

Biomed Imaging Interv J, 2010 10 01;6(4):e37.
PMID: 21611073 DOI: 10.2349/biij.6.4.e37

An incidental finding of an intense focus of (18)F-Fluorodeoxyglucose (FDG) pulmonary uptake on positron emission tomography (PET) without detectable lesions on computed tomography (CT) is highly suggestive of FDG microembolus. Its microscopic nature means it is undetectable on CT. It is an artefact attributable to (18)F-FDG-tracer contamination at the injection site. This paper reports a case of a 61 year-old lady with a past history of breast carcinoma, in whom follow-up PET/CT images demonstrated an incidental intense FDG pulmonary abnormality. A follow-up PET/CT seven months later demonstrated complete resolution of the abnormality.
Fulltext Significance of subcentimetre F-FDG PET/CT pulmonary abnormality in patients with known extrapulmonary malignancy

Fathinul Fikri A, Lau W

Biomed Imaging Interv J, 2010 10 01;6(4):e34.
PMID: 21611070 DOI: 10.2349/biij.6.4.e34

The significance of a subcentimetre (18)F-FDG PET/CT pulmonary abnormality in a patient with known extrapulmonary primary malignancy can have a major impact on the clinical management of the patient. The clinician's reliance on the semi-quantitative and qualitative PET/CT analysis of the abnormality has, at times, led to untoward diagnostic problems, given the limited spatial resolution of PET for a small volume lesion performed as part of the standard PET/CT study. This paper highlights a case each of an FDG-positive and an FDG-negative focal pulmonary abnormality in a combined PET/CT study of patients with known extrapulmonary malignancy. © 2010 Biomedical Imaging and Intervention Journal. All rights reserved.
Sun exposure and the risk of prostate cancer in the Singapore Prostate Cancer Study: a case-control study

Chia SE, Wong KY, Cheng C, Lau W, Tan PH

Asian Pac J Cancer Prev, 2012;13(7):3179-85.
PMID: 22994730

BACKGROUND: Most of the epidemiology studies on the effects of sun exposure and prostate cancer were conducted among the temperate countries of North America and Europe. Little is known about the influence on Asian populations. The purpose of current study was to evaluate any association of sun exposure with risk of prostate cancer in Chinese, Malays and Indians who reside in the tropics.
METHODS: The Singapore Prostate Cancer Study is a hospital-based case-control study of 240 prostate cancer incident cases and 268 controls conducted in Singapore between April 2007 and May 2009. Detailed information on outdoor activities in the sun, skin colour, sun sensitivity and other possible risk factors were collected in personal interviews. Cases were further classified by Gleason scores and TNM staging. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis, adjusted for age, ethnicity, education, family history of any cancers, BMI and skin colour.
RESULTS: We found that prostate cancer risk was increased in subjects with black/dark-brown eyes (OR 5.88, 95%CI 3.17-10.9), darker skin colour e.g. tan/dark brown/black (OR 7.62, 95%CI 3.41-17.0), frequent sunburn in lifetime (OR 4.30, 95%CI 1.7-11.2) and increased general sun exposure in adulthood per week (OR 2.03, 95%CI 1.09-3.81). The increased risk was consistent for high grade tumours and advanced stage prostate cancers.
CONCLUSION: The findings from this study suggest that excessive sun exposure is a risk factor for prostate cancer in Asians.
Characterization of Coconut cadang-cadang viroid variants from oil palm affected by orange spotting disease in Malaysia

Wu YH, Cheong LC, Meon S, Lau WH, Kong LL, Joseph H, et al.

Arch Virol, 2013 Jun;158(6):1407-10.
PMID: 23397332 DOI: 10.1007/s00705-013-1624-8

A 246-nt variant of Coconut cadang-cadang viroid (CCCVd) has been identified and described from oil palms with orange spotting symptoms in Malaysia. Compared with the 246-nt form of CCCVd from coconut, the oil palm variant substituted C(31)→U in the pathogenicity domain and G(70)→C in the central conserved domain. This is the first sequence reported for a 246-nt variant of CCCVd in oil palms expressing orange spotting symptoms.
Localization and prediction of malignant potential in recurrent pheochromocytoma/paraganglioma (PCC/PGL) using 18F-FDG PET/CT

Fikri AS, Kroiss A, Ahmad AZ, Zanariah H, Lau WF, Uprimny C, et al.

Acta Radiol, 2014 Jun;55(5):631-40.
PMID: 24037430 DOI: 10.1177/0284185113504330

To our knowledge, data are lacking on the role of 18F-FDG PET/CT in the localization and prediction of neuroendocrine tumors, in particular the pheochromocytoma/paraganglioma (PCC/PGL) group.

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