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Fulltext Metabolic Syndrome Based on IDF Criteria in a Sample of Normal Weight and Obese School Children

Quah YV, Poh BK, Ismail MN

Malays J Nutr, 2010 Aug;16(2):207-17.
PMID: 22691926 MyJurnal

Metabolic syndrome was once reported only in adults but is now occurring more frequently in children. This study compared the incidence of metabolic syndrome and its components among normal and obese children using the 2007 International Diabetes Federation (IDF) pediatric definition for metabolic syndrome. Subjects comprised 78 school children aged 8-10 years, with 34 obese and 44 normal weight children. Body weight, height, and waist circumference (WC) were measured and body mass index was calculated. Clinical profiles measured included fasting blood glucose, triglyceride, HDL cholesterol, LDL cholesterol, total cholesterol, and blood pressure. Metabolic syndrome (MS) was defined using the 2007 IDF pediatric criteria. Obese subjects had a significantly (p< 0.001) higher mean BMI (26.0 ± 3.6 kg/m2) compared to normal weight subjects (15.1 ± 0.8 kg/m2). Only one obese subject (1.3% of subjects) had metabolic syndrome based on the IDF definition, but all obese subjects had at least one component of metabolic syndrome. In comparison, no normal weight subjects had metabolic syndrome and only 9.1% of normal weight subjects had at least one component of metabolic syndrome. The most common component was central obesity, observed in 43.6% of subjects having WC equal to or greater than the 90th percentile. In concurrence with central obesity as the core feature of the IDF criteria, WC showed the strongest correlation with indicators of obesity such as BMI (r=0.938, p< 0.001), fat mass (r=0.912, p< 0.001) and fat-free mass (r=0.863, p< 0.001). We conclude that the problem of metabolic syndrome is more prominent among obese children, although the incidence of MS as defined by the 2007 pediatric IDF criteria, is low in this population (1.3%).
Fulltext New estimates of CMV seroprevalence in Malaysia. Where do we go from here?

Camalxaman SN, Zeenathul NA, Quah YW, Zuridah H, Loh HS

Med J Malaysia, 2012 Apr;67(2):231.
PMID: 22822655
Fulltext Cross-reactivity of Malaysian rat cytomegalovirus strains with its human counterpart

Camalxaman SN, Zeenathul NA, Quah YW, Loh HS, Zuridah H, Sheikh-Omar AR, et al.

Trop Biomed, 2011 Dec;28(3):661-7.
PMID: 22433897 MyJurnal

This study probes into the prospect of cross-reactivity of HCMV with RCMV which has not been acknowledged to date. We describe the uncovering of a protein with an estimated size of between 61-68 kDa from local RCMV strains which reacted with HCMV positive sera. Our findings are a first disclosure of a plausible immunological cross-reactivity between RCMV with its human counterpart which grounds substantial interest implying existence of conserved determinants between rat and human CMV polypeptides. The cross-reactive protein most likely represents an enveloped glycoprotein, though the precise identification and its degree of similarity needs to be evidently defined and further elucidated in forthcoming experiments.
Fulltext Antibacterial, anti-glucosidase, and antioxidant activities of selected highland ferns of Malaysia

Chai TT, Elamparuthi S, Yong AL, Quah Y, Ong HC, Wong FC

Bot Stud, 2013 Dec;54(1):55.
PMID: 28510890 DOI: 10.1186/1999-3110-54-55

BACKGROUND: Ferns contain natural products with potential therapeutic applications. Current knowledge of the pharmacological properties of ferns, specifically those growing at high altitudes, is limited. This study aimed to evaluate the phytochemical contents as well as antibacterial, anti-glucosidase, and antioxidant activities of four highland ferns in Malaysia.
RESULTS: Aqueous extracts of the leaves and rhizomes of Cyathea latebrosa, Dicranopteris curranii, Gleichenia truncata, and Phymatopteris triloba were analysed. P. triloba leaf extract had the highest contents of total flavonoids (118.6 mg/g dry matter), hydroxycinnamic acids (69.7 mg/g dry matter), and proanthocyanidins (29.4 mg/g dry matter). P. triloba leaf and rhizome extracts as well as G. truncata leaf extract inhibited the growth of both Gram-positive and Gram-negative bacteria. P. triloba leaf extract produced a minimum inhibitory concentration (MIC) value of 0.78 mg dry matter/mL when tested against Pseudomonas aeruginosa, which is 2.5-fold higher than that of ampicillin. Among all extracts, P. triloba leaf extract had the highest anti-glucosidase activity (EC50 = 56 μg dry matter/mL) and also the highest antioxidant potential based on DPPH radical scavenging and Ferric Reducing Antioxidant Power assays. Antioxidant activities of both the leaf and rhizome extracts correlated positively with total flavonoid and hydroxycinnamic acid contents (R(2) = 0.80-0.95). On the other hand, anti-glucosidase activity correlated with total proanthocyanidin contents in both the leaf and rhizome extracts (R(2) = 0.62-0.84).
CONCLUSIONS: In conclusion, highland ferns are potential sources of antibacterial agents, glucosidase inhibitors, and antioxidants.
Fulltext Purification and identification of novel cytotoxic oligopeptides from soft coral Sarcophyton glaucum

Quah Y, Mohd Ismail NI, Ooi JLS, Affendi YA, Abd Manan F, Teh LK, et al.

J Zhejiang Univ Sci B, 2019 1 8;20(1):59-70.
PMID: 30614230 DOI: 10.1631/jzus.B1700586

Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay on the human cervical cancer (HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ (428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration (EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.
Rapid quantitative high-throughput mouse embryoid body model for embryotoxicity assessment

Quah Y, Jung S, Ham O, Jeong JS, Kim S, Kim W, et al.

Arch Toxicol, 2024 Sep 05.
PMID: 39235594 DOI: 10.1007/s00204-024-03845-9

Individuals are exposed to a wide arrays of hazardous chemicals on a daily basis through various routes, many of which have not undergone comprehensive toxicity assessments. While traditional developmental toxicity tests involving pregnant animals are known for their reliability, they are also associated with high costs and time requirements. Consequently, there is an urgent demand for alternative, cost-efficient, and rapid in vitro testing methods. This study aims to address the challenges related to automating and streamlining the screening of early developmental toxicity of chemicals by introducing a mouse embryoid body test (EBT) model in a 384-ultra low attachment well format. Embryoid bodies (EBs) generated in this format were characterized by a spontaneous differentiation trajectory into cardiac mesoderm by as analyzed by RNA-seq. Assessing prediction accuracy using reference compounds suggested in the ICH S5(R3) guideline and prior studies resulted in the establishment of the acceptance criteria and applicability domain of the EBT model. The results indicated an 84.38% accuracy in predicting the developmental toxicity of 23 positive and 9 negative reference compounds, with an optimized cutoff threshold of 750 µM. Overall, the developed EBT model presents a promising approach for more rapid, high-throughput chemical screening, thereby facilitating well-informed decision-making in environmental management and safety assessments.
Predictive biomarkers for embryotoxicity: a machine learning approach to mitigating multicollinearity in RNA-Seq

Quah Y, Jung S, Chan JY, Ham O, Jeong JS, Kim S, et al.

Arch Toxicol, 2024 Sep 06.
PMID: 39242367 DOI: 10.1007/s00204-024-03852-w

Multicollinearity, characterized by significant co-expression patterns among genes, often occurs in high-throughput expression data, potentially impacting the predictive model's reliability. This study examined multicollinearity among closely related genes, particularly in RNA-Seq data obtained from embryoid bodies (EB) exposed to 5-fluorouracil perturbation to identify genes associated with embryotoxicity. Six genes-Dppa5a, Gdf3, Zfp42, Meis1, Hoxa2, and Hoxb1-emerged as candidates based on domain knowledge and were validated using qPCR in EBs perturbed by 39 test substances. We conducted correlation studies and utilized the variance inflation factor (VIF) to examine the existence of multicollinearity among the genes. Recursive feature elimination with cross-validation (RFECV) ranked Zfp42 and Hoxb1 as the top two among the seven features considered, identifying them as potential early embryotoxicity assessment biomarkers. As a result, a t test assessing the statistical significance of this two-feature prediction model yielded a p value of 0.0044, confirming the successful reduction of redundancies and multicollinearity through RFECV. Our study presents a systematic methodology for using machine learning techniques in transcriptomics data analysis, enhancing the discovery of potential reporter gene candidates for embryotoxicity screening research, and improving the predictive model's predictive accuracy and feasibility while reducing financial and time constraints.
Fulltext Trifolium pratense ethanolic extract alters the gut microbiota composition and regulates serum lipid profile in the ovariectomized rats

Quah Y, Park NH, Lee EB, Lee KJ, Yi-Le JC, Ali MS, et al.

BMC Complement Med Ther, 2022 Jan 04;22(1):5.
PMID: 34983484 DOI: 10.1186/s12906-021-03486-w

BACKGROUND: Trifolium pratense (red clover) ethanolic extract (TPEE) has been used as a popular over-the-counter remedy for the management of menopausal symptoms. Prolonged consumption of herbal extract has been shown to regulate the composition of gut microbiota. This study was designed to elucidate the influence of TPEE on the gut microbiota composition in the ovariectomized (OVX) rats.
METHODS: OVX rats were treated with TPEE at 125, 250, 500 mg/kg/day, or controls (pomegranate extract, 500 mg/kg/day; estradiol, 25 μg/kg/day) for 12 weeks. Gut microbiota analysis was conducted by extracting the microbial DNA from fecal samples and microbiome taxonomic profiling was carried out by using next-generation sequencing. The levels of serum biomarkers were analyzed using enzyme-linked immunosorbent assay (ELISA) kit. The prediction of functional biomarker of microbiota was performed using PICRUSt to investigate the potential pathways associated with gut health and serum lipid profile regulation. To study the correlation between gut microbiota composition and serum lipid levels, Spearman's correlation coefficients were defined and analyzed. Additionally, gas chromatography-mass spectrometry analysis was conducted to uncover additional physiologically active ingredients.
RESULTS: TPEE-treated OVX rats showed significant reduction in serum triglycerides (TG), total cholesterols (TCHOL), and LDL/VLDL levels but increase in HDL level. The alteration in the pathways involve in metabolism was the most common among the other KEGG categories. Particularly, TPEE also significantly reduced the relative abundance of sequences read associated with inflammatory bowel disease (IBD) and the peroxisome proliferator-activated receptor (PPAR) signalling pathway. TPEE intervention was seen to reduce the Firmicutes to Bacteroidetes (F/B) ratio in the OVX rats, denoting a reduction in microbial dysbiosis in the OVX rats. Correlation analysis at the phylum level revealed that Bacteriodetes and Proteobacteria were strongly correlated with serum TG, TCHOL and HDL levels. At the species level, Bifidobacterium pseudolongum group was seen to positively correlate with serum HDL level and negatively correlated with serum AST, ALT, LDL/VLDL, TCHOL, and TG levels.
CONCLUSIONS: TPEE treatment showed therapeutic benefits by improving the intestinal microbiota composition which strongly correlated with the serum lipid and cholesterol levels in the OVX rats.