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A curious case of neuromyelitis optica spectrum disorder co-existing with idiopathic intracranial hypertension

Viswanathan S, Wong LC

J Clin Neurosci, 2017 07;41:104-106.
PMID: 28343917 DOI: 10.1016/j.jocn.2017.03.026
Fulltext Meta-analysis of incidence of early lung toxicity in 3-dimensional conformal irradiation of breast carcinomas

Gokula K, Earnest A, Wong LC

Radiat Oncol, 2013;8:268.
PMID: 24229418 DOI: 10.1186/1748-717X-8-268

This meta-analysis aims to ascertain the significance of early lung toxicity with 3-Dimensional (3D) conformal irradiation for breast carcinomas and identify the sub-groups of patients with increased risk.
Fulltext Dermatologic reactions to disinfectant use during the COVID-19 pandemic

Goh CF, Ming LC, Wong LC

Clin Dermatol, 2020 10 02;39(2):314-322.
PMID: 34272029 DOI: 10.1016/j.clindermatol.2020.09.005

Infection preventive practice of using disinfectants against SARS-CoV-2 has become the new normal due to the COVID-19 pandemic. Although disinfectants may not be applied directly to the human body, it remains at high risk of exposure including close skin contact on disinfected surfaces or during handling. This dermal contact, on a regular basis, can induce hazardous skin reactions like irritation, inflammation, and burning in severe conditions. Disinfectants are germicide chemicals that can penetrate the skin and create skin reactions that are usually regarded as irritant and allergic contact dermatitis. More importantly, disinfectants can react with skin components (proteins and lipids) to facilitate their skin penetration and disrupt the skin barrier function. Whereas the antimicrobial actions of disinfectants are well understood, much less is known regarding their dermatologic reactions, including but not limited to irritation and hypersensitivity. We reviewed the skin reactions created by those disinfectants against SARS-CoV-2 approved by the European Chemical Agency and the US Environmental Protection Agency.
Designing cellulose hydrogels from non-woody biomass

Wong LC, Leh CP, Goh CF

Carbohydr Polym, 2021 Jul 15;264:118036.
PMID: 33910744 DOI: 10.1016/j.carbpol.2021.118036

Hydrogels are an attractive system for a myriad of applications. While most hydrogels are usually formed from synthetic materials, lignocellulosic biomass appears as a sustainable alternative for hydrogel development. The valorization of biomass, especially the non-woody biomass to meet the growing demand of the substitution of synthetics and to leverage its benefits for cellulose hydrogel fabrication is attractive. This review aims to present an overview of advances in hydrogel development from non-woody biomass, especially using native cellulose. The review will cover the overall process from cellulose depolymerization, dissolution to crosslinking reaction and the related mechanisms where known. Hydrogel design is heavily affected by the cellulose solubility, crosslinking method and the related processing conditions apart from biomass type and cellulose purity. Hence, the important parameters for rational designs of hydrogels with desired properties, particularly porosity, transparency and swelling characteristics will be discussed. Current challenges and future perspectives will also be highlighted.
The effect of pre-phototest sun exposure on minimal erythema dose and minimal melanogenic dose among skin phototypes III, IV and V

Wong LC, Jamil A, Md Nor N

Photodermatol Photoimmunol Photomed, 2018 Nov;34(6):400-404.
PMID: 29953669 DOI: 10.1111/phpp.12410

BACKGROUND: Ethnicity, skin phototype and colour influenced minimal erythema dose (MED). Sun exposure has been postulated to increase MED. We determined immediate pigment darkening dose to UVA (IPDDA), MED and minimal melanogenic dose (MMD) for UVB and UVA, and investigated factors affecting these doses.
METHODS: Skin phototype was determined using Fitzpatrick phototype quiz, DSMII ColorMeter measured skin colours, sun exposure quantified using an index (SEI) and phototest performed with MEDlight-Multitester.
RESULTS: A total of 167 healthy volunteers participated. There were 110 (66%) females and 56 (34%) males; 124 (74.7%) were Malay, 27 (16.3%) Chinese and 14 (8.4%) Indians. One hundred and nine (65.7%) skin phototype IV, 30 (18.1%) phototype III and 27 (16.3%) phototype V. IPDDA ranges from 6 ± 1.5-5.7 ± 1.4 J/cm2 . MED-UVB were 96.9 ± 17.6, 124 ± 29.3 and 118.6 ± 27.4 mJ/cm2 for phototype III, IV and V, respectively. All MED-UVA were outside the tested dose range of 3.6-11 J/cm2 . MMD-UVB were 106 ± 18.2, 134 ± 25.6 and 136 ± 31.1 mJ/cm2 while MMD-UVA were 4.1 ± 4.1, 4.9 ± 3.8 and 5.7 ± 3.7 J/cm2 respectively for phototypes III, IV and V. MED-UVB, MMD-UVB and MMD-UVA did not depend on skin phototype. Facultative skin whiteness (L*), erythema (E) and melanin content (M) correlated significantly with MED-UVB while constitutive skin colours were significant for L*, yellowness (b*), E and M. Sun exposure did not significantly correlate with MED-UVB and MMDs, however, an inverse relationship with MED-UVB was demonstrated.
CONCLUSION: Minimal erythema doses in our cohort were slightly different from other regional countries. Constitutive and facultative skin whiteness, erythema and melanin content correlated with MED. There was no association between skin phototype and sun exposure with MED or MMD.
Lutein improves cell viability and reduces Alu RNA accumulation in hydrogen peroxide challenged retinal pigment epithelial cells

Chong YS, Mai CW, Leong CO, Wong LC

Cutan Ocul Toxicol, 2018 Mar;37(1):52-60.
PMID: 28554225 DOI: 10.1080/15569527.2017.1335748

PURPOSE: Dysfunction of the microRNA (miRNA)-processing enzyme DICER1 and Alu RNA accumulation are linked to the pathogenesis of age-related macular degeneration (AMD). This study determined the optimal dose of lutein (LUT) and zeaxanthin (ZEA) to protect human retinal pigment epithelium (RPE) cells against hydrogen peroxide (H2O2). The effect of the optimal dose of LUT and ZEA as DICER1 and Alu RNA modulators in cultured human RPE cells challenged with H2O2 was investigated.
MATERIALS AND METHODS: ARPE-19 cells were pre-treated with LUT, ZEA, or both for 24 h before 200 μM H2O2 challenge. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. DICER1 and Alu RNA were quantified by western blotting and real-time polymerase chain reaction, respectively.
RESULTS: H2O2 increased cell Alu RNA expression and decreased cell viability of ARPE-19, but had no significant impact on the DICER1 protein level. LUT, alone and in combination with ZEA pre-treatment, prior to H2O2 challenge significantly improved cell viability of ARPE-19 and reduced the level of Alu RNA compared to the negative control.
CONCLUSIONS: These results support the use of LUT alone, and in combination with ZEA, in AMD prevention and treatment. This study is also the first to report LUT modulating effects on Alu RNA.
Fulltext Comparison of vegetable oils on the uptake of lutein and zeaxanthin by ARPE-19 cells

Baek J, Mai CW, Lim WM, Wong LC

Int J Ophthalmol, 2023;16(1):40-46.
PMID: 36659939 DOI: 10.18240/ijo.2023.01.06

AIM: To compare the effect of vegetable oils on the uptake of lutein and zeaxanthin by adult retinal pigment epithelial (ARPE)-19 cells in vitro.
METHODS: ARPE-19 cells were cultured in Dulbecco's Modified Eagle Medium-F-12 supplemented with 10% foetal bovine serum and 1% penicillin-streptomycin in a humidified 5% CO2 incubator maintained at 37°C. Cells were treated with 247 µmol/L lutein, 49 µmol/L zeaxanthin and 1% (v/v) of either coconut oil, corn oil, peanut oil, olive oil, sunflower oil, soybean oil, castor oil, or linseed oil for 48h. Lutein and zeaxanthin concentration in the cells were quantified by high performance liquid chromatography.
RESULTS: Among the oils tested, the highest lutein and zeaxanthin uptake was observed with coconut oil while the lowest was observed with linseed oil.
CONCLUSION: ARPE-19 uptake of lutein and zeaxanthin are found to be dependent on the type of oils.
The synthesis of trifluoromethylated N-nitroaryl-2-amino-1,3-dichloropropane derivatives and their evaluation as potential anti-cancer agents

Chappel L, Wong LC, Leong CO, Mai CW, Meikle IT, Stanforth SP, et al.

Bioorg Med Chem Lett, 2020 02 15;30(4):126910.
PMID: 31882300 DOI: 10.1016/j.bmcl.2019.126910

Six N-nitroaryl-2-amino-1,3-dichloropropane derivatives have been prepared and evaluated against 18 cancer cell lines and two non-cancerous cell lines. Analysis of cell viability data and IC50 values indicated that the presence of a trifluoromethyl group in the nitroaryl moiety is an important structural feature associated with the compounds' cytotoxicities.
Cellulose hydrogel development from unbleached oil palm biomass pulps for dermal drug delivery

Wong LC, Poh JH, Tan WT, Khor BK, Murugaiyah V, Leh CP, et al.

Int J Biol Macromol, 2023 Jan 01;224:483-495.
PMID: 36273545 DOI: 10.1016/j.ijbiomac.2022.10.138

Hydrogels are an attractive platform for drug delivery to the skin. Current cellulose hydrogel developments commonly focus on readily available bleached woody cellulose. Considering the detrimental environmental impacts of bleaching reagents, unbleached non-woody biomass was proposed as an alternative. Herein, this study aims to develop hydrogel from native cellulose extracted from oil palm empty fruit bunches for dermal drug delivery with an emphasis on evaluating the effect of alkali solvent compositions on hydrogel formation. Unbleached dissolving pulps were solubilized in alkali solvents containing sodium hydroxide (NaOH) (6-8%w/v) and urea (4-6%w/v) before crosslinking. Hydrogels were loaded with ibuprofen for skin permeation studies. Light brownish hydrogels formed are aesthetically acceptable and biodegradable with low cytotoxicity. NaOH content has a dominant role over urea where thinner and deformable crosslinked network walls in a porous hydrogel structure are associated with high NaOH content. Synergistic effects (cellulose solubility: 94 %; swelling ratio: ~2800 %) were observed at 7%w/v NaOH and 4%w/v urea with low toxicity. Most hydrogels showed >80 % of ibuprofen permeated into the skin and this increased with the swelling ratio of hydrogels. Unbleached cellulose pulps have excellent potential for hydrogel fabrication with outstanding physicomechanical properties for dermal drug delivery.
Fulltext The prevalence of obesity among clinical students in a Malaysian medical school

Boo NY, Chia GJ, Wong LC, Chew RM, Chong W, Loo RC

Singapore Med J, 2010 Feb;51(2):126-32.
PMID: 20358151

INTRODUCTION: This study aimed to determine the prevalence of obesity among medical students and its relationship with their dietary intake and physical activities.
METHODS:This observational study was carried out on 240 medical students during the clinical phase of their medical course in a private medical school. Their body weight and height were measured, and a standardised questionnaire was used to collect information on their physical activities and dietary intake.
RESULTS: The median body weight of the participants was 59.0 kg (interquartile range: 51.3-66.8), the mean body height was 166.1 cm (standard deviation [SD] 8.5 cm), and the mean body mass index (BMI) was 21.8 kg/m2 (SD 3.4 kg/m2). Based on the World Health Organization BMI cut-offs for the Asian population, 30.1 percent (n is equal to 72) of the students were overweight or obese, with a BMI that was equal to or greater than 23.0 kg/m2. Logistic regression analysis showed that, after controlling for various potential confounders, the only significant risk factors associated with overweight/obesity among these students were: male gender (adjusted odds ratio [OR] 2.1; 95 percent confidence intervals [CI] of 1.1 and 4.1; p is equal to 0.03), Malay ethnic group (adjusted OR 2.4; 95 percent CI 1.0 and 5.7; p is equal to 0.04), Indian ethnic group (adjusted OR 3.6; 95 percent CI 1.5 and 8.9; p is equal to 0.005), and the number of soft drinks consumed per week (adjusted OR 1.3; 95 percent CI 1.0 and 1.5; p is equal to 0.02). Skipping breakfast, the frequency of physical exercise per week, the number of hours of sleep per day, and eating noodles or roti canai (a type of Malaysian pancake) for breakfast were not significant risk factors.
CONCLUSION: Obesity remains a common problem among medical students in their clinical years.
Coffee consumption revealed sex differences in host endogenous metabolism and gut microbiota in healthy adults

Chong CW, Wong LC, Teh CSJ, Ismail NH, Chan PQ, Lim CS, et al.

J Food Biochem, 2020 12;44(12):e13535.
PMID: 33103260 DOI: 10.1111/jfbc.13535

Coffee is rich in antioxidant and has been shown to confer various health benefits. Here, we investigated the effect of single-dose coffee consumption in healthy human subjects. About 30 healthy volunteers were recruited and given a serving of sugar free black coffee. Urine and fecal samples were collected and analyzed. Significant changes in urinary metabolites relating to coffee, gut microbial and host energy metabolisms were observed post-coffee consumption. Clear sex differences were also observed in the urinary metabolic profiles pre- and post-coffee consumption. Sex differences in richness and composition of gut microbiota were observed, however, the effect of single-dose coffee consumption on host gut microbiota were unremarkable. These findings indicated that single-dose coffee consumption affects sex-specific host metabolic responses that relates to gut-microbe and energy metabolism. This study demonstrated the utility of systems biology tools to unravel complexity of host-diet biology and gut microbial responses. PRACTICAL APPLICATIONS: This study demonstrated that integrated systems biology approach enabled efficient extractions of host biochemical and microbial information that allows food industry to ascertain the impact of diet and longitudinal assessment of potential functional food in humans.
Variants in ZFX are associated with an X-linked neurodevelopmental disorder with recurrent facial gestalt

Shepherdson JL, Hutchison K, Don DW, McGillivray G, Choi TI, Allan CA, et al.

Am J Hum Genet, 2024 Mar 07;111(3):487-508.
PMID: 38325380 DOI: 10.1016/j.ajhg.2024.01.007

Pathogenic variants in multiple genes on the X chromosome have been implicated in syndromic and non-syndromic intellectual disability disorders. ZFX on Xp22.11 encodes a transcription factor that has been linked to diverse processes including oncogenesis and development, but germline variants have not been characterized in association with disease. Here, we present clinical and molecular characterization of 18 individuals with germline ZFX variants. Exome or genome sequencing revealed 11 variants in 18 subjects (14 males and 4 females) from 16 unrelated families. Four missense variants were identified in 11 subjects, with seven truncation variants in the remaining individuals. Clinical findings included developmental delay/intellectual disability, behavioral abnormalities, hypotonia, and congenital anomalies. Overlapping and recurrent facial features were identified in all subjects, including thickening and medial broadening of eyebrows, variations in the shape of the face, external eye abnormalities, smooth and/or long philtrum, and ear abnormalities. Hyperparathyroidism was found in four families with missense variants, and enrichment of different tumor types was observed. In molecular studies, DNA-binding domain variants elicited differential expression of a small set of target genes relative to wild-type ZFX in cultured cells, suggesting a gain or loss of transcriptional activity. Additionally, a zebrafish model of ZFX loss displayed an altered behavioral phenotype, providing additional evidence for the functional significance of ZFX. Our clinical and experimental data support that variants in ZFX are associated with an X-linked intellectual disability syndrome characterized by a recurrent facial gestalt, neurocognitive and behavioral abnormalities, and an increased risk for congenital anomalies and hyperparathyroidism.