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  1. Ng, Yen, Green Mark, A.
    MyJurnal
    Carbon-11 labeled radiotracers, such as 11C-acetate and
    11C-palmitate are widely used in positron
    emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied
    physiological conditions.These tracers are attractive probes of tissue physiology, because they are
    simply radiolabled versions of the native biochemical substrates. One of the major metabolites
    generated by these tracers upon the administration is 11CO2 produced via the citric acid cycle. In
    quantitative modeling of
    11C-acetate and
    11C-palmitate PET data, the fraction of blood
    11C
    radioactivity present as
    11CO2 needs to be measured to obtain a correct radiotracer arterial
    input function. Accordingly, the literature describes a method whereby the total blood
    11C-activity
    is counted in blood samples treated with base solution, while the fraction of
    1 1CO2 is measured
    after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed
    description of the experimental validation of this method was not provided. The goal of this study
    was to test the reliability of a 10 minute gas purging method used to assay
    11CO2 radioactivity in
    blood
  2. Muhammad Fakhrurazi Ahmad Fadzil, Ng Yen, Siti Najila Mohd Janib, Noor Hasnah M. Khairullah, Mohd Khairul Najah
    MyJurnal
    PET/CT Scan with obGa-labelled analogs is of increasing interest in Nuclear Medicine and currently
    is being performed all over the world. However, such labeling procedure requires high purity and
    concentrated solutions of°sGa. Here we report the purification and concentration of the eluate of
    SnOi-Based obGe/obGa generators via the anion exchange method. Three different anion columns were
    selected to purify and concentrate the6SGa eluat.es which are Chromafix, Oasis WAX and AG 1-X8
    columns. The different anion columns were compared and evaluated in terms of their capability in
    adsorption and desorption of ""Ga from, the generator. While the optimum molarity of Hydrocholric
    Acid (HCl) for highest 6dGa retention was also determined starting from the ranges of fM to 7M of
    HCl. The results showed that the percentage of 68Ga retention or adsorption .started to be plateau at
    molarity of 5.5M for all three anion cartridges. One-way ANOVA analysis proved that there is no
    significant difference between 5.5M with 6.0M, 6.5M and 7.0M which means that the retention of
    gallium-68 is equal at those molarities. At 5.5M, Chromafix and Oasis WAX cartridges showed the
    highest retention of gallium-68 which is 98.30%. The lowest 6"Ga retention was gained by AG 1-X8
    column which is 97.07%'. While for desorption of 6bGa, the highest percentage was obtained by using
    Oasis WAX cart/ridges which, is 70.f9% followed by Chromafix which, is 70.36%. The lowest desorption
    of gallium-68 was obtained by using AG 1-X8 column which is only 58.56%. Therefore, from this
    study, the most suitable cartridge and HCl molarity that should be applied in purification and
    concentration of Gallium-68 eluate fromÿ a SnOs Based °*Ge/*Ga generator is Oasis® WAX column
    with a HCl molarity of 5.5M respectively.
  3. Abbasi YF, See OG, Ping NY, Balasubramanian GP, Hoon YC, Paruchuri S
    Diabetes Metab Syndr, 2018 Nov;12(6):1057-1063.
    PMID: 30017505 DOI: 10.1016/j.dsx.2018.06.025
    Diabetes is among leading public health concerns in Malaysia due to premature and preventable mortality involving macro and microvascular complications. Diabetes knowledge, attitude, and practice (KAP) are vital in diabetes management. The present study assessed the level of diabetes KAP among type 2 diabetes patients with associated and correlated factors through a self-administered questionnaire-based study on a convenience sample of 386 type 2 diabetes mellitus patients in Kuala Muda District, Kedah, Malaysia. Majority of the respondents possessed levels above the cut-off points for poor levels in knowledge (63.21%), attitude (62.69%), and practices (58.03%). Age, academic qualification, occupation, monthly income, current therapy type, comorbid diseases, and therapy preference were associated with KAP whereas the associations of disease duration, the best source of information about diabetes, and health status satisfaction were witnessed for attitude and practice. Academic qualification had strongest correlation for knowledge (r = 0.785), attitude (r = 0.725), and practice (r = 0.709). Knowledge level was significantly correlated with attitude level (r = 0.735), practice level (r = 0.786), income (r = 0.556), occupation (r = 0.358), age (r = 0.173), current therapy type (r = 0.133), and diabetes education exposure (r = 0.113). Attitude level had significant correlations with practice level (r = 0.679), income (r = 0.357), occupation (r = 0.348), health status satisfaction (r = 0.147), age (r = 0.145), and gender (r = 0.109). Practice level correlated significantly with income (r = 0.448), occupation (r = 0.317), age (r = 0.173), health status satisfaction (r = 0.167), and current therapy type (r = 0.118). All associations and correlations were significant at P 
  4. Zhang L, Feng XK, Ng YK, Li SC
    BMC Genomics, 2016 Aug 18;17 Suppl 4:430.
    PMID: 27556418 DOI: 10.1186/s12864-016-2791-2
    BACKGROUND: Accurately identifying gene regulatory network is an important task in understanding in vivo biological activities. The inference of such networks is often accomplished through the use of gene expression data. Many methods have been developed to evaluate gene expression dependencies between transcription factor and its target genes, and some methods also eliminate transitive interactions. The regulatory (or edge) direction is undetermined if the target gene is also a transcription factor. Some methods predict the regulatory directions in the gene regulatory networks by locating the eQTL single nucleotide polymorphism, or by observing the gene expression changes when knocking out/down the candidate transcript factors; regrettably, these additional data are usually unavailable, especially for the samples deriving from human tissues.

    RESULTS: In this study, we propose the Context Based Dependency Network (CBDN), a method that is able to infer gene regulatory networks with the regulatory directions from gene expression data only. To determine the regulatory direction, CBDN computes the influence of source to target by evaluating the magnitude changes of expression dependencies between the target gene and the others with conditioning on the source gene. CBDN extends the data processing inequality by involving the dependency direction to distinguish between direct and transitive relationship between genes. We also define two types of important regulators which can influence a majority of the genes in the network directly or indirectly. CBDN can detect both of these two types of important regulators by averaging the influence functions of candidate regulator to the other genes. In our experiments with simulated and real data, even with the regulatory direction taken into account, CBDN outperforms the state-of-the-art approaches for inferring gene regulatory network. CBDN identifies the important regulators in the predicted network: 1. TYROBP influences a batch of genes that are related to Alzheimer's disease; 2. ZNF329 and RB1 significantly regulate those 'mesenchymal' gene expression signature genes for brain tumors.

    CONCLUSION: By merely leveraging gene expression data, CBDN can efficiently infer the existence of gene-gene interactions as well as their regulatory directions. The constructed networks are helpful in the identification of important regulators for complex diseases.

  5. Chan Mun Wei J, Zhao Z, Li SC, Ng YK
    Comput Biol Chem, 2018 Jun;74:428-433.
    PMID: 29625871 DOI: 10.1016/j.compbiolchem.2018.03.010
    DNA fingerprinting, also known as DNA profiling, serves as a standard procedure in forensics to identify a person by the short tandem repeat (STR) loci in their DNA. By comparing the STR loci between DNA samples, practitioners can calculate a probability of match to identity the contributors of a DNA mixture. Most existing methods are based on 13 core STR loci which were identified by the Federal Bureau of Investigation (FBI). Analyses based on these loci of DNA mixture for forensic purposes are highly variable in procedures, and suffer from subjectivity as well as bias in complex mixture interpretation. With the emergence of next-generation sequencing (NGS) technologies, the sequencing of billions of DNA molecules can be parallelized, thus greatly increasing throughput and reducing the associated costs. This allows the creation of new techniques that incorporate more loci to enable complex mixture interpretation. In this paper, we propose a computation for likelihood ratio that uses NGS (next generation sequencing) data for DNA testing on mixed samples. We have applied the method to 4480 simulated DNA mixtures, which consist of various mixture proportions of 8 unrelated whole-genome sequencing data. The results confirm the feasibility of utilizing NGS data in DNA mixture interpretations. We observed an average likelihood ratio as high as 285,978 for two-person mixtures. Using our method, all 224 identity tests for two-person mixtures and three-person mixtures were correctly identified.
  6. Zhang Y, Liu W, Lin Y, Ng YK, Li S
    BMC Genomics, 2019 Apr 04;20(Suppl 2):186.
    PMID: 30967119 DOI: 10.1186/s12864-019-5470-2
    BACKGROUND: Recent advances in genome analysis have established that chromatin has preferred 3D conformations, which bring distant loci into contact. Identifying these contacts is important for us to understand possible interactions between these loci. This has motivated the creation of the Hi-C technology, which detects long-range chromosomal interactions. Distance geometry-based algorithms, such as ChromSDE and ShRec3D, have been able to utilize Hi-C data to infer 3D chromosomal structures. However, these algorithms, being matrix-based, are space- and time-consuming on very large datasets. A human genome of 100 kilobase resolution would involve ∼30,000 loci, requiring gigabytes just in storing the matrices.

    RESULTS: We propose a succinct representation of the distance matrices which tremendously reduces the space requirement. We give a complete solution, called SuperRec, for the inference of chromosomal structures from Hi-C data, through iterative solving the large-scale weighted multidimensional scaling problem.

    CONCLUSIONS: SuperRec runs faster than earlier systems without compromising on result accuracy. The SuperRec package can be obtained from http://www.cs.cityu.edu.hk/~shuaicli/SuperRec .

  7. Ng YP, Ahmed R, Ooi GS, Lau CY, Balasubramanian GP, Yap CH
    Diabetes Metab Syndr, 2018 Nov;12(6):1025-1030.
    PMID: 30168425 DOI: 10.1016/j.dsx.2018.06.018
    INTRODUCTION: In Malaysia, 61% of dialysis cases are secondary to diabetes. To date, we are still lacking of data on the rate of progression of type 2 diabetes mellitus (T2DM) to end stage renal disease (ESRD) in Malaysia.

    MATERIALS AND METHODS: This was a retrospective study conducted at nephrology unit of a tertiary hospital in Kedah. All diabetic ESRD patients who fulfilled the inclusion criteria were identified and recruited for analysis.

    RESULTS: The mean duration of DM to ESRD was found to be 14.37 ± 4.42 years. Mean duration for the onset of diabetic nephropathy was 8.73 ± 3.37 years. There was a relative short duration from diabetic nephropathy to ESRD noted, which was 5.63 ± 2.06 years. The mean duration of DM to ESRD for patients receiving RAAS blocker was found to be 18.23 ± 2.38 years as compared to 11.41 ± 2.94 years for those who did not (95% CI: -0.64 to -2.46). For different type of RAAS blockers, namely ACE inhibitor and angiotensin receptor blocker (ARB), there was no significant difference observed pertaining to mean duration of DM to ESRD; 17.89 ± 1.97 years for ACEi and 19.00 ± 4.16 years for ARB (95% CI: -4.74 to 2.52).

    DISCUSSION: Time frame from diabetic nephropathy to ESRF among Malaysian population was shorter as compared to findings from other countries with an average period of 15 to 25 years. RAAS blockers should be initiated early in diabetic patients.

  8. Heng WK, Choo JY, Ng YP, Loh KS, Chua YH
    Nutr Health, 2022 Dec;28(4):489-493.
    PMID: 35404174 DOI: 10.1177/02601060221089105
    Background: Obesity is a complex and multifactorial disease that is strongly associated with multiple comorbidities and mortality. Weight reduction in overweight and obese patients was highly desired to minimize future complications. Meal replacement is emerging as one of the effective tools to promote weight loss. Isoflavones and soy protein present in soybean are able to promote weight loss and alleviate obesity. Aim: Our systematic review aims to investigate the weight loss effect of soy-based meal replacement among the overweight and obese population. Methods: We will conduct a systematic review of RCTs that evaluated the effect of a soy-based meal replacement on weight loss in overweight and obese patients. The primary outcome of this review is weight loss. Besides that, we will assess BMI, body fat, waist circumference and hip circumference as the secondary outcome. We will search PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library. Two reviewers will independently screen titles and abstracts, review full texts, extract information and assess the risk of bias of individual studies. We will conduct meta-analyses using a random-effect model if sufficient data are available. If meta-analysis is not performed, we will present a systematic qualitative synthesis. Summary: This systematic review will identify the weight loss effect of soy-based meal replacement among the overweight and obese adult population. We expect the result may strengthen the evidence on the role of soy-based meal replacement in optimal body weight management.
  9. Ng YP, Balasubramanian GP, Heng YP, Kalaiselvan M, Teh YW, Cheong KM, et al.
    Diabetes Metab Syndr, 2018 May;12(3):305-308.
    PMID: 29279269 DOI: 10.1016/j.dsx.2017.12.005
    AIMS: Recent data showed an alarming rise of new dialysis cases secondary to diabetic nephropathy despite the growing usage of RAAS blockers. Primary objective of this study is to explore the prevalence of RAAS blockers usage among type II diabetic patients, secondary objectives are to compare the prescribing pattern of RAAS blocker between primary and tertiary care center and to explore if the dose of RAAS blocker prescribed was at optimal dose as suggested by trials.

    MATERIALS AND METHODS: This is a retrospective study conducted at one public tertiary referral hospital and one public health clinic in Sungai Petani, Kedah, Malaysia.

    RESULTS: RAAS blockers in T2DM patients was found to be 65%. In primary care, 14.3% of the RAAS blockers prescribed was ARB. Tertiary care had higher utilization of ARB, which was 42.9%. In primary care setting, the most commonly used ACEI were perindopril (92.4%) followed by enalapril (7.6%), meanwhile perindopril was the only ACEI being prescribed in tertiary care. The most prescribed ARB was irbesartan (63.6%) and telmisartan (54.2%) respectively in primary and tertiary care. Overall, 64.9% of RAAS blockers prescribed by both levels of care were found to be achieving the target dose as recommended in landmark trials. Crude odd ratio of prescribing RAAS blocker in primary care versus tertiary care was reported as 2.70 (95% CI: 1.49 to 4.91).

    CONCLUSION: RAAS blockers usage among T2DM patients was higher in primary care versus tertiary care settings. Majority of the patients did not receive optimal dose of RAAS blockers.
  10. Voon PT, Lee ST, Ng TKW, Ng YT, Yong XS, Lee VKM, et al.
    Adv Nutr, 2019 Jul 01;10(4):647-659.
    PMID: 31095284 DOI: 10.1093/advances/nmy122
    It is not clear whether a saturated fatty acid-rich palm olein diet has any significant adverse effect on established surrogate lipid markers of cardiovascular disease (CVD) risk. We reviewed the effect of palm olein with other oils on serum lipid in healthy adults. We searched in MEDLINE and CENTRAL: Central Register of Controlled Trials from 1975 to January 2018 for randomized controlled trials of ≥2 wk intervention that compared the effects of palm olein (the liquid fraction of palm oil) with other oils such as coconut oil, lard, canola oil, high-oleic sunflower oil, olive oil, peanut oil, and soybean oil on changes in serum lipids. Nine studies were eligible and were included, with a total of 533 and 542 subjects on palm olein and other dietary oil diets, respectively. We extracted and compared all the data for serum lipids, such as total cholesterol (TC), LDL cholesterol, HDL cholesterol, triglyceride, and TC/HDL cholesterol ratio. When comparing palm olein with other dietary oils, the overall weighted mean differences for TC, LDL cholesterol, HDL cholesterol, triglycerides, and the TC/HDL cholesterol ratio were -0.10 (95% CI: -0.30, 0.10; P = 0.34), -0.06 (95% CI: -0.29,0.16; P = 0.59), 0.02 (95% CI: -0.01, 0.04; P = 0.20), 0.01 (95% CI: -0.05, 0.06; P = 0.85), and -0.15 (95% CI: -0.43, 0.14; P = 0.32), respectively. Overall, there are no significant differences in the effects of palm olein intake on lipoprotein biomarkers (P > 0.05) compared with other dietary oils. However, dietary palm olein was found to have effects comparable to those of other unsaturated dietary oils (monounsaturated fatty acid- and polyunsaturated fatty acid-rich oils) but differed from that of saturated fatty acid-rich oils with respect to the serum lipid profile in healthy adults.
  11. Voon PT, Ng CM, Ng YT, Wong YJ, Yap SY, Leong SL, et al.
    Adv Nutr, 2024 Jul 23;15(9):100276.
    PMID: 39053603 DOI: 10.1016/j.advnut.2024.100276
    Vegetable oils, derived from diverse sources such as seeds, nuts, and some fruits, play a significant role in dietary health. However, the current evidence on the health effects of different types of vegetable oil consumption remains controversial. This umbrella review aims to synthesize evidence from systematic reviews and meta-analyses to assess the health outcomes associated with various vegetable oils. A comprehensive literature search was performed up to 31 July, 2023 on 12 databases for studies examining the association of different vegetable oils with health outcomes in adults. Data was extracted independently by 2 authors, with evidence strength assessed using the grading of recommendations, assessment, development, and evaluation criteria. A total of 48 studies, including 206 meta-analyses, were included. Moderate to very low certainty evidence showed that monounsaturated and polyunsaturated fatty acids such as canola oil, virgin olive oil, and rice bran oil are beneficial in reducing serum total cholesterol and low-density lipoprotein (LDL) concentrations. Conversely, low to very low certainty evidence suggests that oils high in saturated fats, such as coconut oil and palm oil, increase total cholesterol and LDL concentrations but also raise high-density lipoprotein concentrations. Very low certainty evidence showed the consumption of olive oil, sesame oil, and coconut oil could improve blood sugar control. Low certainty evidence showed olive oil consumption reduced risk of breast, digestive, and other cancers. Moderate to very low certainty evidence suggested that canola oil and sesame oil consumption reduced body weight. The consumption of vegetable oil appears to offer different health benefits, with summary estimates indicating beneficial effects on reducing lipid concentrations, especially with monounsaturated and polyunsaturated rich oils when consumed in recommended amounts. Future research should focus on long-term studies and comprehensive dietary assessments to better understand the health impacts of vegetable oils, providing a basis for informed dietary recommendations. This study was registered at PROSPERO as CRD42021239210.
  12. Zakarial Ansar FH, Latifah SY, Wan Kamal WHB, Khong KC, Ng Y, Foong JN, et al.
    Int J Nanomedicine, 2020;15:7703-7717.
    PMID: 33116496 DOI: 10.2147/IJN.S262395
    Background: Thymoquinone (TQ), an active compound isolated from Nigella sativa, has been proven to exhibit various biological properties such as antioxidant. Although oral delivery of TQ is valuable, it is limited by poor oral bioavailability and low solubility. Recently, TQ-loaded nanostructured lipid carrier (TQ-NLC) was formulated with the aim of overcoming the limitations. TQ-NLC was successfully synthesized by the high-pressure homogenization method with remarkable physiochemical properties whereby the particle size is less than 100 nm, improved encapsulation efficiency and is stable up to 24 months of storage. Nevertheless, the pharmacokinetics and biodistribution of TQ-NLC have not been studied. This study determined the bioavailability of oral and intravenous administration of thymoquinone-loaded nanostructured lipid carrier (TQ-NLC) in rats and its distribution to organs.

    Materials and Methods: TQ-NLC was radiolabeled with technetium-99m before the administration to the rats. The biodistribution and pharmacokinetics parameters were then evaluated at various time points. The rats were imaged at time intervals and the percentage of the injected dose/gram (%ID/g) in blood and each organ was analyzed.

    Results: Oral administration of TQ-NLC exhibited greater relative bioavailability compared to intravenous administration. It is postulated that the movement of TQ-NLC through the intestinal lymphatic system bypasses the first metabolism and therefore enhances the relative bioavailability. However, oral administration has a slower absorption rate compared to intravenous administration where the AUC0-∞ was 4.539 times lower than the latter.

    Conclusion: TQ-NLC had better absorption when administered intravenously compared to oral administration. However, oral administration showed greater bioavailability compared to the intravenous route. This study provides the pharmacokinetics and biodistribution profile of TQ-NLC in vivo which is useful to assist researchers in clinical use.

  13. Foo JN, Tan LC, Liany H, Koh TH, Irwan ID, Ng YY, et al.
    Hum Mol Genet, 2014 Jul 15;23(14):3891-7.
    PMID: 24565865 DOI: 10.1093/hmg/ddu086
    To evaluate the contribution of non-synonymous-coding variants of known familial and genome-wide association studies (GWAS)-linked genes for Parkinson's disease (PD) to PD risk in the East Asian population, we sequenced all the coding exons of 39 PD-related disease genes and evaluated the accumulation of rare non-synonymous-coding variants in 375 early-onset PD cases and 399 controls. We also genotyped 782 non-synonymous-coding variants of these genes in 710 late-onset PD cases and 9046 population controls. Significant enrichment of LRRK2 variants was observed in both early- and late-onset PD (odds ratio = 1.58; 95% confidence interval = 1.29-1.93; P = 8.05 × 10(-6)). Moderate enrichment was also observed in FGF20, MCCC1, GBA and ITGA8. Half of the rare variants anticipated to cause loss of function of these genes were present in healthy controls. Overall, non-synonymous-coding variants of known familial and GWAS-linked genes appear to make a limited contribution to PD risk, suggesting that clinical sequencing of these genes will provide limited information for risk prediction and molecular diagnosis.
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