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  1. Tang KF, Lightner DV
    Dis Aquat Organ, 2011 Feb 22;93(3):191-8.
    PMID: 21516971 DOI: 10.3354/dao02293
    We describe a duplex real-time PCR assay using TaqMan probes for the simultaneous detection of monodon baculovirus (MBV) and hepatopancreatic parvovirus (HPV). Both MBV and HPV are shrimp enteric viruses that infect intestinal and hepatopancreatic epithelial cells. Both viruses can cause significant mortalities and depressed growth in infected larval, postlarval, and early juvenile stages of shrimp, and thus present a risk to commercial aquaculture. In this duplex assay, we combined 2 single real-time PCRs, amplifying MBV and HPV, in a one-tube PCR reaction. The 2 viruses were distinguished by specific fluorescent labels at the 5' end of TaqMan probes: the MBV probe was labeled with dichlorodimethoxyfluorescein (JOE), and the HPV probe was labeled with 6-carboxyfluorescein (FAM). The duplex real-time PCR assay was performed in a multi-channel real-time PCR detection system, and MBV and HPV amplification signals were separately detected by the JOE and FAM channels. This duplex assay was validated to be specific to the target viruses and found to have a detection limit of single copies for each virus. The dynamic range was found to be from 1 to 1 x 10(8) copies per reaction. This assay was further applied to quantify MBV and HPV in samples of infected Penaeus monodon collected from Malaysia, Indonesia, and Thailand. The specificity and sensitivity of this duplex real-time PCR assay offer a valuable tool for routine diagnosis and quantification of MBV and HPV from both wild and farmed shrimp stocks.
  2. Tang KF, Abdullah MP, Yusoff K, Tan WS
    J Med Chem, 2007 Nov 15;50(23):5620-6.
    PMID: 17918821
    The core protein (HBcAg) of hepatitis B virus (HBV) has been shown to interact with the large surface antigen during HBV morphogenesis, and these interactions can be blocked by small peptides selected from either linear or constrained phage display peptide libraries. The association of HBcAg with peptide inhibitors was quantitatively evaluated by isothermal titration calorimetry. The thermodynamic data show that the interaction between HBcAg and peptide MHRSLLGRMKGA is enthalpy-driven and occurs at a 3:1 stoichiometry and dissociation constant (Kd) value of 79.4 muM. However, peptide WSFFSNI displays a higher binding affinity for HBcAg with a Kd value of 18.5 muM when compared to peptide MHRSLLGRMKGA. A combinatorial approach using chemical cross-linking and surface-enhanced laser desorption/ionization-time-of-flight-mass spectrometry shows that the Lys of peptide MHRSLLGRMKGA interacted either with D64, E77, or D78 of HBcAg.
  3. Tan CSS, Wong YJ, Tang KF, Lee SWH
    Diabetes Metab Syndr, 2023 Feb;17(2):102724.
    PMID: 36791634 DOI: 10.1016/j.dsx.2023.102724
    BACKGROUND AND AIMS: Hypoglycaemia due to fasting during Ramadan may affect the ability to perform complex activities among people with type 2 diabetes mellitus (T2D), but it is unclear how this affects one's ability to drive. This study aims to explore driving experiences and coping strategies to ensure safe driving among people with T2D who fast during Ramadan.

    METHODS: We conducted an exploratory qualitative study and purposefully selected people with T2D who drove and fasted during the past Ramadan period in 2019. In-depth face-to-face interviews were conducted and transcribed verbatim. Data were analysed thematically using a constant comparative method until saturation was achieved (n = 16).

    RESULTS: Two major themes were identified, namely: (1) knowing oneself and (2) voluntary self-restriction. Participants described the importance of understanding how Ramadan fasting affected them and their level of alertness. As such, participants often adjusted their daily activities and tested their blood glucose levels to prevent experiencing hypoglycaemia. Other coping strategies reported include adjusting their medications and driving restrictions or driving in the mornings when they were more alert. Findings from this study shed light on participants' experiences and coping mechanisms while driving during Ramadan.

    CONCLUSION: Given the risks and effects of hypoglycaemia among those who fast, there is a need to provide appropriate and focused patient education during Ramadan to people with T2D to ensure they can perform complex activities such as driving safely, especially in Muslim majority countries.

  4. Tang KF, Teh PL, Lee SWH
    Innov Aging, 2023;7(1):igad005.
    PMID: 36908650 DOI: 10.1093/geroni/igad005
    BACKGROUND AND OBJECTIVES: This review aimed to summarize the association between cognitive frailty (presence of frailty and cognitive impairment) and the risk of disabilities in activities of daily living (ADL), instrumental ADL (IADL), mobility, or other functional disabilities among older adults.

    RESEARCH DESIGN AND METHODS: PubMed, Embase, CINAHL Plus, and PsycINFO were searched from January 2001 to May 14, 2022, for observational studies that reported cognitive frailty among community-dwelling individuals aged 60 years and above. Results were narratively synthesized.

    RESULTS: Eleven studies encompassing 44 798 participants were included, with a prevalence of cognitive frailty ranging from 1.4% to 39.3%. Individuals with cognitive frailty were more likely to develop disabilities in ADL and IADL compared to robust (absence of frailty and cognitive impairment) individuals. Significant disability burden and elevated risk of combined ADL/IADL disability or physical limitation among participants with cognitive frailty were reported. There was limited evidence on the association between cognitive frailty and mobility disability.

    DISCUSSION AND IMPLICATIONS: Individuals with cognitive frailty were likely at higher risk of developing functional disability and incurring higher disability burden than robust individuals, but evidence remains limited for those with prefrailty with cognitive impairment. Further research on this gap and standardization of cognitive frailty assessments would facilitate comparisons across populations.

    PROSPERO REGISTRATION: CRD42021232222.

  5. Tang KF, Pantoja CR, Redman RM, Han JE, Tran LH, Lightner DV
    J Invertebr Pathol, 2015 Sep;130:37-41.
    PMID: 26146228 DOI: 10.1016/j.jip.2015.06.009
    A microsporidian parasite, Enterocytozoon hepatopenaei (abbreviated as EHP), is an emerging pathogen for penaeid shrimp. EHP has been found in several shrimp farming countries in Asia including Vietnam, Thailand, Malaysia, Indonesia and China, and is reported to be associated with growth retardation in farmed shrimp. We examined the histological features from infected shrimp collected from Vietnam and Brunei, these include the presence of basophilic inclusions in the hepatopancreas tubule epithelial cells, in which EHP is found at various developmental stages, ranging from plasmodia to mature spores. By a PCR targeting the 18S rRNA gene, a 1.1kb 18S rRNA gene fragment of EHP was amplified, and this sequence showed a 100% identity to EHP found in Thailand and China. This fragment was cloned and labeled with digoxigenin-11-dUTP, and in situ hybridized to tissue sections of infected Penaeus vannamei (from Vietnam) and P. stylirostris (Brunei). The results of in situ hybridization were specific, the probe only reacted to the EHP within the cytoplasmic inclusions, not to a Pleistophora-like microsporidium that is associated with cotton shrimp disease. Subsequently, we developed a PCR assay from this 18S rRNA gene region, this PCR is shown to be specific to EHP, did not react to 2 other parasitic pathogens, an amoeba and the cotton shrimp disease microsporidium, nor to genomic DNA of various crustaceans including polychaetes, squids, crabs and krill. EHP was detected, through PCR, in hepatopancreatic tissue, feces and water sampled from infected shrimp tanks, and in some samples of Artemia biomass.
  6. Umareddy I, Tang KF, Vasudevan SG, Devi S, Hibberd ML, Gu F
    J Gen Virol, 2008 Dec;89(Pt 12):3052-3062.
    PMID: 19008393 DOI: 10.1099/vir.0.2008/001594-0
    Outbreaks of dengue disease are constant threats to tropical and subtropical populations but range widely in severity, from mild to haemorrhagic fevers, for reasons that are still elusive. We investigated the interferon (IFN) response in infected human cell lines A549 and HepG2, using two strains (NGC and TSV01) of dengue serotype 2 (DEN2) and found that the two viruses exhibited a marked difference in inducing type I IFN response. While TSV01 infection led to activation of type I antiviral genes such as EIF2AK2 (PKR), OAS, ADAR and MX, these responses were absent in NGC-infected cells. Biochemical analysis revealed that NGC but not TSV01 suppressed STAT-1 and STAT-2 activation in response to type I IFN (alpha and beta). However, these two strains did not differ in their response to type II IFN (gamma). Although unable to suppress IFN signalling, TSV01 infection caused a weaker IFN-beta induction compared with NGC, suggesting an alternative mechanism of innate immune escape. We extended our study to clinical isolates of various serotypes and found that while MY10245 (DEN2) and MY22713 (DEN4) could suppress the IFN response in a similar fashion to NGC, three other strains of dengue [EDEN167 (DEN1), MY02569 (DEN1) and MY10340 (DEN2)] were unable to suppress the IFN response, suggesting that this difference is strain-dependent but not serotype-specific. Our report indicates the existence of a strain-specific virulence factor that may impact on disease severity.
  7. Yau PN, Foo CJE, Cheah NLJ, Tang KF, Lee SWH
    Epidemiol Health, 2022;44:e2022058.
    PMID: 35843601 DOI: 10.4178/epih.e2022058
    OBJECTIVES: Functional disability is a common consequence of the ageing process and can lead to poor health outcomes due to the inability to perform activities of daily living (ADL) and instrumental activities of daily living (IADL) independently. However, the prevalence of functional disability among older adults in the Association of Southeast Asian Nations (ASEAN) region is poorly documented. This study aimed to assess the prevalence of functional disability and its impact on older adults in the ASEAN region.

    METHODS: A systematic literature search was performed on 4 databases from inception until March 2021 to identify studies examining individuals aged 60 years and above reporting functional disabilities in the ASEAN region. Information on the prevalence and impact of functional disability was extracted, assessed for bias, summarised, and analysed using a random-effects meta-analysis.

    RESULTS: Thirty-four studies with 59,944 participants were included. The pooled prevalence of ADL disability was 21.5% (95% confidence interval [CI], 16.2 to 27.3) and that of IADL disability was 46.8% (95% CI, 35.5 to 58.3). Subgroup analyses showed higher prevalence among those of advanced age and women. Adverse impacts included increased years of life with disability and poor health-related quality of life.

    CONCLUSIONS: Nearly a quarter of the older adult population in the ASEAN region experience functional disability. These findings highlight the need for further research on the burden and impact of functional disability within this region to allow decision-makers to gauge the severity of the issue, develop policies to reduce the risk of developing functional disabilities, and foster healthy ageing.

  8. Boey KPY, Zhu P, Tan H, Abdullah MAB, Tang KF, Li MM, et al.
    Transfus Med, 2022 Feb;32(1):82-87.
    PMID: 34862686 DOI: 10.1111/tme.12834
    OBJECTIVE: To evaluate the effects of cryopreservation in post-thaw umbilical cord blood units for the survivability of Gram-positive bacteria strains.

    BACKGROUND: Microbial screening is required for all cord blood units (CBUs). Four gram-positive contaminants were documented to survive cryopreservation poorly and isolation of other contaminants were reported.

    METHODS: Forty-eight contaminated CBUs detected with either Staphylococcus epidermidis, Corynebacterium species, Peptostreptococcus or Streptococcus species before cryopreservation were used in this study. CBUs were processed, DMSO-infused and microbial screened before cryopreservation. Post-thaw microbial screening was achieved using 1 and 10 ml inoculants in BACTEC culture bottles. Positive bottles were subjected for microbial identification and results were compared with those from pre-freeze.

    RESULTS: A higher rate of microbial contamination was found using the 10 ml inoculant. Screening of 11 CBUs did not detect any contaminants while 30 CBUs screened detected more than one unknown contaminants and majority of contaminants were identified to be gram-negative species.

    CONCLUSION: A higher inoculation volume used at post-thaw for microbial screening improves contamination detection but leads to the loss of precious cord blood. Some contaminants did not survive cryopreservation or were not identified due to their low microbial levels. Contrasting contaminants found at post-thaw suggest the improvements made in detection and identification of contaminants over the years.

  9. Fun WH, Sararaks S, Tan EH, Tang KF, Chong DWQ, Low LL, et al.
    BMC Health Serv Res, 2019 Apr 24;19(1):248.
    PMID: 31018843 DOI: 10.1186/s12913-019-4072-7
    BACKGROUND: Health Research Priority Setting (HRPS) in the Ministry of Health (MOH) Malaysia was initiated more than a decade ago to drive effort toward research for informed decision and policy-making. This study assessed the impact of funded prioritised research and identified research gaps to inform future priority setting initiatives for universal access and quality healthcare in Malaysia.

    METHODS: Research impact of universal access and quality healthcare projects funded by the National Institutes of Health Malaysia were assessed based on the modified Payback Framework, addressing categories of informing policy, knowledge production, and benefits to health and health sector. For the HRPS process, the Child Health and Nutrition Research Initiative methodology was adapted and adopted, with the incorporation of stakeholder values using weights and monetary allocation survey. Workshop discussions and interviews with stakeholders and research groups were conducted to identify research gaps, with the use of conceptual frameworks to guide the search.

    RESULTS: Seventeen ongoing and 50 completed projects were identified for research funding impact analysis. Overall, research fund allocation differed from stakeholders' expectation. For research impact, 48 out of 50 completed projects (96.0%) contributed to some form of policy-making efforts. Almost all completed projects resulted in outputs that contributed to knowledge production and were expected to lead to health and health sector benefits. The HRPS process led to the identification of research priority areas that stemmed from ongoing and new issues identified for universal access and quality healthcare.

    CONCLUSION: The concerted efforts of evaluation of research funding impact, prioritisation, dissemination and policy-maker involvement were valuable for optimal health research resource utilisation in a resource constrained developing country. Embedding impact evaluation into a priority setting process and funding research based on national needs could facilitate health research investment to reach its potential.

  10. Jailani AS, Balqis-Ali NZ, Tang KF, Fun WH, Samad SA, Jahaya R, et al.
    BMC Public Health, 2023 Nov 14;23(1):2243.
    PMID: 37964260 DOI: 10.1186/s12889-023-17132-2
    INTRODUCTION: High-risk human papillomavirus (HPV) screening is vital for early cervical cancer detection and treatment. With the introduction of the national cervical cancer screening programme and screening registry in Malaysia, there is a need to monitor population-based HPV screening uptake and high-risk HPV prevalence as part of cervical cancer surveillance.

    OBJECTIVE: To determine the prevalence and sociodemographic factors predicting high-risk HPV infection in Malaysia based on a public, community-based cervical cancer screening registry targeting women at risk of getting HPV infection.

    METHODS: The study used data from the Malaysian cervical cancer screening registry established by the Family Health Development Division from 2019 to 2021. The registry recorded sociodemographic data, HPV test details and results of eligible women who underwent HPV screening at public primary healthcare facilities. A vaginal sample (via self-sampling or assisted by a healthcare provider) was used for DNA extraction for HPV detection and genotyping. Registry data were extracted and analysed to determine prevalence estimates of high-risk HPV infection. Multifactorial logistic regression analysis was conducted to determine predictors of high-risk HPV infection. All analyses were performed using Stata version 14.

    RESULTS: The programme screened a total of 36,738 women during the study period. Women who attended the screening programme were mainly from urban areas, aged 30-39 years, and of Malay ethnicity. The prevalence of high-risk HPV infection was 4.53% among women screened, with the yearly prevalence ranging from 4.27 to 4.80%. A higher prevalence was observed among urban settling women, those aged 30-49 years, those of Indian ethnicity, and those without children. The results from logistic regression showed that women from urban areas, lower age groups, of Indian or Chinese ethnicity, and who are self-employed were more likely to be infected with high-risk HPV.

    CONCLUSION: Targeted and robust strategies to reach identified high-risk groups are needed in Malaysia. In addition, the registry has the potential to be expanded for an improved cervical cancer elimination plan.

    TRIAL REGISTRATION: Trial registration number: NMRR ID-22-00187-DJU.

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