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Viability of dengue virus in culture stocks is efficiently preserved by storage in diluted forms

Suppiah J, Nadaraju S, Hamzah S, Chee HY

Trop Biomed, 2020 Jun 01;37(2):282-287.
PMID: 33612798

Storage of dengue virus (DENV) culture stocks in -80°C is a common laboratory practice to maintain the viability of the virus for long-term usage. However, the efficiency of this method could still be hindered by multiple factors. In our laboratory, we observed a constant and substantial deterioration in the titer of DENV in Vero culture supernatant stored in -80°C. Such incident had badly hampered the laboratory work and prompted an investigation to determine the cause. DENV isolates representing all four serotypes were propagated and the culture supernatants were harvested and stored in aliquots of original stock and 10 fold dilutions (10-1 -10-4). DENV titer in these stocks was determined prior to storage and reassessed on the third and sixth month of storage by focus forming unit assay (FFUA). The result demonstrated a constant preservation of titer ranging from 104 ffu/ml to 105 ffu/ml in the diluted DENV virus culture stocks of 10-1, and 10-2 of DENV1-4, a minor reduction of titer from 103 ffu/ml to 102 ffu/ml at dilution 10-3 for DENV4 only and complete deterioration in undiluted culture stock and lower dilution (10-4) within 6 months of storage in -80°C for all serotypes. It is recommended that propagated DENV in Vero cells are stored in 10 fold dilutions as compared to the original form to preserve the titer for long-term usage.
Uncontrolled haemorrhage in a premature baby

BOON WH, CHEE HW

Med J Malaya, 1956 Mar;10(3):267-9.
PMID: 13347459
Ultrastructural changes of cell morphology and viral morphogenesis of two ecotypes of dengue virus infection in human monocytic U-937 cell

Fish-Low CY, Abu Bakar S, Othman F, Chee HY

Trop Biomed, 2018 Dec 01;35(4):1154-1159.
PMID: 33601863

Dengue virus (DENV) is maintained and circulated in both sylvatic/enzootic and endemic/human cycles and spill over infection of sylvatic DENV into human populations has been reported. Extensive deforestation and increase human activities in forest may increase the risk of human exposure to sylvatic dengue infection and this may become a threat to human. Present study investigated the changes in cell morphology and viral morphogenesis upon infection with sylvatic and endemic ecotypes in human monocytic U-937 cells using transmission electron microscopy. Autophagy, a process that is either pro-viral or anti-viral, was observed in U-937 cells of both infections, however only the replication of endemic DENV was evidenced. An insight into the infection responses of sylvatic progenitors of DENV in susceptible host cells may provide better understanding on dengue emergence in human populations.
Ultrastructural aspects of sylvatic dengue virus infection in Vero cell

Fish-Low CY, Abubakar S, Othman F, Chee HY

Malays J Pathol, 2019 Apr;41(1):41-46.
PMID: 31025636

INTRODUCTION: Dengue virus (DENV), the causative agent of dengue disease exists in sylvatic and endemic ecotypes. The cell morphological changes and viral morphogenesis of two dengue ecotypes were examined at the ultrastructural level to identify potential similarities and differences in the surrogate model of enzootic host.
MATERIALS AND METHODS: Vero cells were inoculated with virus at a multiplicity of infection (MOI) of 0.1. Cell cultures were harvested over a time course and processed for transmission electron microscopic imaging.
RESULTS: The filopodia protrusions on cell periphery preceded virus entry. Additionally, sylvatic DENV infection was found spreading slower than the endemic DENV. Morphogenesis of both dengue ecotypes was alike but at different level of efficiency in the permissive cells.
CONCLUSIONS: This is the first ultrastructural study on sylvatic DENV and this comparative study revealed the similarities and differences of cellular responses and morphogenesis of two dengue ecotypes in vitro. The study revealed the weaker infectivity of sylvatic DENV in the surrogate model of enzootic host, which supposed to support better replication of enzootic DENV than endemic DENV.
Fulltext The prevalence of musculoskeletal problems and risk factors among women assembly workers in the semiconductor industry

Chandrasakaran A, Chee HL, Rampal KG, Tan GLE

Med J Malaysia, 2003 Dec;58(5):657-66.
PMID: 15190650

A cross-sectional study to determine work-related musculoskeletal problems and ergonomic risk factors was conducted among 529 women semiconductor workers. Overall, 83.4% had musculoskeletal symptoms in the last one year. Pain in the back (57.8%), lower leg (48.4%) and shoulder (44.8%) were the three most common musculoskeletal problems. Significant associations were found between prolonged standing and upper and lower leg pain, between prolonged sitting and neck and shoulder pain and between prolonged bending and shoulder arm, back and upper leg pain. The study therefore showed a clear association between work-related musculoskeletal pain and prolonged hours spent in particular postures and movements.
Fulltext The APEC Digital Hub-WONCA Collaborative Framework on Integration of Mental Health into Primary Care in the Asia Pacific

Dowrick C, Kassai R, Lam CLK, Lam RW, Manning G, Murphy J, et al.

J Multidiscip Healthc, 2020;13:1693-1704.
PMID: 33268991 DOI: 10.2147/JMDH.S271070

Mental ill health affects individual well-being and national economic prosperity and makes up a substantial portion of the burden of disease globally, especially in the Asia-Pacific region. Integrating mental health into primary care is widely considered a key strategy to improve access to mental health care. Integration, however, is a complex process that needs to be addressed at multiple levels. A collaboration between the Asia-Pacific Economic Cooperation (APEC) Digital Hub for Mental Health and the World Organization of Family Doctors (WONCA) is described in this paper, which outlines a framework and next steps to improve the mental health of communities in APEC economies. This paper notes gaps related to the integration of mental health into primary care across the region and identifies enablers and current best practices from several APEC economies. The potential of digital technology to benefit primary mental health care for populations in the APEC region, including delivery of training programs for healthcare staff and access to resources for patients, is described. Finally, key next steps are proposed to promote enhanced integration into primary care and improve mental health care throughout the APEC region.
Fulltext Relationship between selected health problems and exposures among women semiconductor workers in Malaysia

Chee HL, Rampal KG

Med J Malaysia, 2003 Aug;58(3):387-98.
PMID: 14750379

A study conducted between 1998-2001 on the semiconductor industry in Penang and Selangor found that irregular menstruation, dysmenorrhea and stress were identified as the three leading health problems by women workers from a checklist of 16 health problems. After adjusting for confounding factors, including age, working duration in current factory, and marital status, in a multiple logistic regression model, wafer polishing workers were found to experience significantly higher odds of experiencing irregular menstruation. Dysmenorrhea was found to be significantly associated with chemical usage and poor ventilation, while stress was found to be related to poor ventilation, noise and low temperatures.
Relation between sick leave and selected exposure variables among women semiconductor workers in Malaysia

Chee HL, Rampal KG

Occup Environ Med, 2003 Apr;60(4):262-70.
PMID: 12660374

To determine the relation between sick leave and selected exposure variables among women semiconductor workers.
Putative apolipoprotein A-I, natural killer cell enhancement factor and lysozyme g are involved in the early immune response of brown-marbled grouper, Epinephelus fuscoguttatus, Forskal, to Vibrio alginolyticus

Low CF, Shamsudin MN, Chee HY, Aliyu-Paiko M, Idrus ES

J Fish Dis, 2014 Aug;37(8):693-701.
PMID: 24304156 DOI: 10.1111/jfd.12153

The gram-negative bacterium, Vibrio alginolyticus, has frequently been identified as the pathogen responsible for the infectious disease called vibriosis. This disease is one of the major challenges facing brown-marbled grouper aquaculture, causing fish farmers globally to suffer substantial economic losses. The objective of this study was to investigate the proteins involved in the immune response of brown-marbled grouper fingerlings during their initial encounter with pathogenic organisms. To achieve this objective, a challenge experiment was performed, in which healthy brown-marbled grouper fingerlings were divided into two groups. Fish in the treated group were subjected to intraperitoneal injection with an infectious dose of V. alginolyticus suspended in phosphate-buffered saline (PBS), and those in the control group were injected with an equal volume of PBS. Blood samples were collected from a replicate number of fish from both groups at 4 h post-challenge and analysed for immune response-related serum proteins via two-dimensional gel electrophoresis. The results showed that 14 protein spots were altered between the treated and control groups; these protein spots were further analysed to determine the identity of each protein via MALDI-TOF/TOF. Among the altered proteins, three were clearly overexpressed in the treated group compared with the control; these were identified as putative apolipoprotein A-I, natural killer cell enhancement factor and lysozyme g. Based on these results, these three highly expressed proteins participate in immune response-related reactions during the initial exposure (4 h) of brown-marbled grouper fingerling to V. alginolyticus infection.
Pseudoephedrine at international borders: advising the unwary traveller

Flaherty GT, Liew CH, Leggat PA

J Travel Med, 2019 Jan 01;26(1).
PMID: 30521043 DOI: 10.1093/jtm/tay144
Fulltext Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia

Thung TY, Radu S, Mahyudin NA, Rukayadi Y, Zakaria Z, Mazlan N, et al.

Front Microbiol, 2017;8:2697.
PMID: 29379488 DOI: 10.3389/fmicb.2017.02697

The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S. Enteritidis and S. Typhimurium in the meat samples. The prevalence of Salmonella spp., S. Enteritidis and S. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of <3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S. Agona was the predominant serovar (26.09%). Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S. Typhimurium isolates (8.70%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100%) were positive for the invA gene. Meanwhile, pefA was only identified in S. Enteritidis and S. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars.
Fulltext Prevalence of malnutrition among children in an urban squatter settlement in Petaling Jaya

Chee HL

Med J Malaysia, 1992 Sep;47(3):170-81.
PMID: 1491642

In a study of mild to significant malnutrition in an urban squatter settlement, the weights for age of 297 children between birth and ten years, and the heights for age and weights for height of 197 children between two to ten years were analysed. Using NCHS standards, the overall prevalence of underweight was found to be 18.9%, stunting 15.2%, and wasting 11.2%. Age and ethnicity were significantly associated with the prevalence of underweight and stunting. The growth achievement of children below the age of two years were significantly better off than the older children, and Chinese children significantly better off than Malay and Indian children.
Fulltext Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia

Tan CW, Malcolm TTH, Kuan CH, Thung TY, Chang WS, Loo YY, et al.

Front Microbiol, 2017;8:1087.
PMID: 28659901 DOI: 10.3389/fmicb.2017.01087

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from <3 to >10(5) MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >10(5) MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus.
Prescription of antipsychotic and concomitant medications for adult Asian schizophrenia patients: Findings of the 2016 Research on Asian Psychotropic Prescription Patterns (REAP) survey

Dong M, Zeng LN, Zhang Q, Yang SY, Chen LY, Najoan E, et al.

Asian J Psychiatr, 2019 Oct;45:74-80.
PMID: 31520884 DOI: 10.1016/j.ajp.2019.08.010

OBJECTIVE: Regular surveys are important to monitor the use of psychotropic medications in clinical practice. This study examined the psychotropic prescription patterns in adult Asian schizophrenia patients based on the data of the Research on Asian Psychotropic Prescription (REAP) 2016 survey.
METHODS: This cross-sectional survey across 15 Asian countries/territories collected socio-demographic and clinical data with standardized procedures between March and May 2016. The socio-demographic and clinical characteristics of the patients were recorded with a standardized questionnaire.
RESULTS: Altogether 3,537 adult patients with schizophrenia were consecutively screened and enrolled in the survey. The mean age was 38.66 ± 11.55 years and 59.7% of the sample were male. The mean dose of antipsychotics in chlorpromazine equivalents (CPZeq) was 424 ± 376 mg/day; 31.3% and 80.8% received first- and second- generation antipsychotics, respectively and 42.6% had antipsychotic polypharmacy, 11.7% had antidepressants, 13.7% had mood stabilizers, 27.8% had benzodiazepines, and 45.6% had anticholinergics.
CONCLUSIONS: Psychotropic prescription patterns in Asian adult patients with schizophrenia varied across countries. Regular surveys on psychotropic medications for schizophrenia are important to monitor pharmacotherapy practice in Asia.
Physical comorbidities in older adults receiving antidepressants in Asia

Zhong XM, Dong M, Wang F, Zhang Q, Ungvari GS, Ng CH, et al.

Psychogeriatrics, 2018 Sep;18(5):351-356.
PMID: 29989257 DOI: 10.1111/psyg.12327

BACKGROUND: The present study explored the patterns of physical comorbidities and their associated demographic and clinical factors in older psychiatric patients prescribed with antidepressants in Asia.
METHODS: Demographic and clinical information of 955 older adults were extracted from the database of the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) project. Standardized data collection procedure was used to record demographic and clinical data.
RESULTS: Proportion of physical comorbidities in this cohort was 44%. Multiple logistic regression analyses showed that older age (OR = 1.7, P
Outbreak of fatal childhood viral infection in Sarawak, Malaysia in 1997: inocula of patients' clinical specimens induce apoptosis in vitro

Abubakar S, Shafee N, Chee HY

Malays J Pathol, 1998 Dec;20(2):71-81.
PMID: 10879266

Identification of the aetiologic agent(s) associated with an outbreak of fatal childhood viral infection in Sarawak, Malaysia, in mid 1997 remains elusive. It is reported here that African green monkey kidney (Vero) and human monocytic (U937) cells treated with inocula derived from clinical specimens of some of these fatal cases showed the presence of cellular genomic DNA degradation when the extracted DNA was separated by pulsed field gel electrophoresis (PFGE), oligonucleosomal DNA ladders characteristic of apoptotic cells when the infected cells' DNA was separated by agarose gel electrophoresis, and apoptotic cellular DNA fragmentation when cells were stained using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). These results suggest that inocula derived from the patients' clinical specimens contain factors which stimulate apoptotic cellular responses in vitro.
Obesogenic television food advertising to children in Malaysia: sociocultural variations

Ng SH, Kelly B, Se CH, Chinna K, Sameeha MJ, Krishnasamy S, et al.

Glob Health Action, 2014 Dec;7(1):25169.
PMID: 28672562 DOI: 10.3402/gha.v7.25169

Background Food advertising on television (TV) is well known to influence children's purchasing requests and models negative food habits in Western countries. Advertising of unhealthy foods is a contributor to the obesogenic environment that is a key driver of rising rates of childhood obesity. Children in developing countries are more at risk of being targeted by such advertising, as there is a huge potential for market growth of unhealthy foods concomitant with poor regulatory infrastructure. Further, in developing countries with multi-ethnic societies, information is scarce on the nature of TV advertising targeting children. Objectives To measure exposure and power of TV food marketing to children on popular multi-ethnic TV stations in Malaysia. Design Ethnic-specific popular TV channels were identified using industry data. TV transmissions were recorded for each channel from November 2012 to August 2013 (16 hr/day) for randomly selected weekdays and weekend days during normal days and repeated during school holidays (n=88 days). Coded food/beverage advertisements were grouped into core (healthy), non-core (non-healthy), or miscellaneous (unclassified) food categories. Peak viewing time (PVT) and persuasive marketing techniques were identified. Results Non-core foods were predominant in TV food advertising, and rates were greater during school holidays compared to normal days (3.51 vs 1.93 food ads/hr/channel, p<0.001). During normal days' PVT, the ratio of non-core to core food advertising was higher (3.25 food ads/hr/channel), and this more than trebled during school holidays to 10.25 food ads/hr/channel. Popular channels for Indian children had the lowest rate of food advertising relative to other ethnic groups. However, sugary drinks remained a popular non-core product advertised across all broadcast periods and channels. Notably, promotional characters doubled for non-core foods during school holidays compared to normal days (1.91 vs 0.93 food ads/hr/channel, p<0.001). Conclusions This study highlights non-core food advertising, and predominantly sugary drinks are commonly screened on Malaysian TV channels. The majority of these sugary drinks were advertised by multinational companies, and this observation warrants regulatory attention.
Fulltext Nutritional status and reproductive health of Orang Asli women in two villages in Kuantan, Pahang

Lim H, Chee H

Malays J Nutr, 1998 Dec;4(1):31-54.
PMID: 22692340 MyJurnal

The study was conducted to determine the nutritional status and reproductive health of 34 Orang Asli women, aged 16-45 years, from two Orang Asli villages in Kuantan, Pahang Darul Makmur.The results of the study indicate that on the whole, the women's nutritional status is generally not satisfactory.Their mean iron intakes for example, are very low, about one-quarter to one-third of the required level.All their other mean nutrient intake levels are below the required level. Only their mean intake of vitamin C exceeds the required level due to their frequent intake of raw vegetables. Their main source of carbohydrate is rice, while their main source of protein is fish, and their main source of minerals and vitamins are Chinese mustard and cabbage.From BMI measurements, it is found that less than half of the women (42.9%) have normal weight, 35.7% suffer from chronic energy deficiency (CED), 7.1% (one) are overweight, and 14.3% (two) are obese.The accessibility and availability of food are a problem for the women, limiting their choice of varieties of food sources.For their reproductive health needs, the pregnant women rely on the government hospital and clinics for their antenatal check-ups and birth deliveries.Of all the women, nine suffer from menstrual pain and five from vaginal discharge.Food taboos and cultural practices are practised by the pregnant women during their confinement.It is concluded that the nutritional status of the women needs to be improved since most of them have insufficient nutrient intake.
Fulltext Nutritional assessment of rural villages and estates in Peninsular Malaysia: I Socio-economic profile of households

Chee H, Khor G, Tee ES

Malays J Nutr, 1997 Mar;3(1):1-19.
PMID: 22692232 MyJurnal

A nutritional study was carried out on six (five rural and one urban) low income groups in Peninsular Malaysia from 1992-1995. In this paper, the socio-economic data for the five rural groups - padi farmers, rubber smallholders, coconut smallholders, estate workers, and fishermen - are presented. With the exception of the estate workers, the sample was predominantly Malay, with an overall mean household size of 5.30. Household incomes were generally low, and 47% of all households had incomes that were below the poverty line income (PLI) of RM405. Based on this PLI, the prevalence of poverty was above 50% among the padi, rubber, coconut, and fishing households. Nevertheless, the study population appeared to be better off in terms of the other indicators examined. Poultry rearing, for example, was widespread in the padi, rubber, and coconut villages; 65% of all households owned at least one motorised vehicle, 53% owned a refrigerator, and 83% owned a television set. Furthermore, over 80% of all households had access to piped water, 96% had electricity supply, and over 90% had a flush or pour-flush latrine. In comparison to the 1979-1983 poverty villages study (Chong et al., 1984), the households in the current study enjoyed better living conditions. Strict comparisons between the two studies, however, is difficult owing to the different criteria adopted in the selection of the study villages.
Fulltext Nutritional assessment of rural villages and estates in Peninsular Malaysia*. III. Prevalence of anaemia

Tee ES, Khor G, Tony N, Yassin Z, Chee H, Mdyusof S

Malays J Nutr, 1998 Dec;4(1):1-29.
PMID: 22692339 MyJurnal

As a part of the recent UPM-IMR collaborative study on the nutritional status of communities in rural villages and estates in Peninsular Malaysia from 1992-1995, this report presents findings on the haemoglobin levels and the prevalence of anaemia amongst these rural dwellers. A total of 69 villages and 7 estates located in 9 states in Peninsular Malaysia were studied. Results of the study on the 5 communities (total n=8024), namely fishing, padi, rubber, coconut and estate communities, are presented according to five age groups, namely less than 7 years (n=1418), 7-12.9 years (n=1778), 13-17.9 years (n=701), 18-59.9 years (n=3241) and 60 years (n=886). The extent of the anaemia problem varied considerably amongst the various age groups and community types. The prevalence of anaemia and mean Hb level (g/dl) for subjects of both sexes were respectively 24% and 12.1 for those < 7 years; 21.9% and 13.0 for the 7-12.9 years old; 17.8% and 13.7 for the 13-17.9 years; 21.0% and 13.8 for 18-59.9 years; and 22.7% and 13.6 for those 60 years of age and above. While the female adults (18-59.9 years) had a significantly higher prevalence rate for anaemia of 25% compared to 14% found in the male adults, no significant difference in the prevalence rates were found between the sexes for the other age groups. The problem was most serious among adult women, young children and the elderly. Amongst the various community types, the fishing community had the highest prevalence of anaemia at an overall rate of 50%, taking into consideration both sexes and all age groups. The rubber smallholders, in contrast, had the lowest prevalence of anaemia, at an overall rate of about 10%. Intervention and preventive health programmes should therefore be continued to be focussed on the above groups of rural subjects, particularly those in the fishing community.

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