Displaying all 11 publications

Abstract:
Sort:
  1. Chan JY, Ooi EH
    Cryobiology, 2016 12;73(3):304-315.
    PMID: 27789380 DOI: 10.1016/j.cryobiol.2016.10.006
    Advancement in biomedical simulation and imaging modality have catalysed the development of in silico predictive models for cryoablation. However, one of the main challenges in ensuring the accuracy of the model prediction is the use of proper thermal and biophysical properties of the patient. These properties are difficult to measure clinically and thus, represent significant uncertainty that can affect the model prediction. Motivated by this, a sensitivity analysis is carried out to identify the model parameters that have the most significant impact on the lesion size during cryoablation. The study is initially carried out using the Morris method to screen for the most dominant parameters. Once determined, analysis of variance (ANOVA) is performed to quantitatively rank the order of importance of each parameter and their interactions. Results from the sensitivity analysis revealed that blood perfusion, water transport and ice nucleation parameters are critical in predicting the lesion size, suggesting that the acquisition of these parameters should be prioritised to ensure the accuracy of the model prediction.
  2. Yeoh AE, Lu Y, Chan JY, Chan YH, Ariffin H, Kham SK, et al.
    Leuk. Res., 2010 Mar;34(3):276-83.
    PMID: 19651439 DOI: 10.1016/j.leukres.2009.07.003
    To study genetic epidemiology of childhood acute lymphoblastic leukemia (ALL) in the Chinese and Malays, we investigated 10 polymorphisms encoding carcinogen- or folate-metabolism and transport. Sex-adjusted analysis showed NQO1 609CT significantly protects against ALL, whilst MTHFR 677CT confers marginal protection. Interestingly, we observed that NQO1 609CT and MTHFR 1298 C-allele have greater genetic impact in boys than in girls. The combination of SLC19A1 80GA heterozygosity and 3'-TYMS -6bp/-6bp homozygous deletion is associated with reduced ALL risk in Malay boys. Our study has suggested the importance of gender and race in modulating ALL susceptibility via the folate metabolic pathway.
  3. Singh O, Chan JY, Lin K, Heng CC, Chowbay B
    PLoS One, 2012;7(12):e51771.
    PMID: 23272163 DOI: 10.1371/journal.pone.0051771
    This study aimed to explore the influence of SLC22A1, PXR, ABCG2, ABCB1 and CYP3A5 3 genetic polymorphisms on imatinib mesylate (IM) pharmacokinetics in Asian patients with chronic myeloid leukemia (CML).
  4. Suleman Ismail Abdalla S, Katas H, Chan JY, Ganasan P, Azmi F, Fauzi MB
    Mol Pharm, 2021 05 03;18(5):1956-1969.
    PMID: 33822631 DOI: 10.1021/acs.molpharmaceut.0c01033
    Gelatin hydrogels are attractive for wound applications owing to their well-defined structural, physical, and chemical properties as well as good cell adhesion and biocompatibility. This study aimed to develop gelatin hydrogels incorporated with bio-nanosilver functionalized with lactoferrin (Ag-LTF) as a dual-antimicrobial action dressing, to be used in treating infected wounds. The hydrogels were cross-linked using genipin prior to loading with Ag-LTF and characterized for their physical and swelling properties, rheology, polymer and actives interactions, and in vitro release of the actives. The hydrogel's anti-biofilm and antibacterial performances against S. aureus and P. aeruginosa as well as their cytotoxicity effects were assessed in vitro, including primary wound healing gene expression of human dermal fibroblasts (HDFs). The formulated hydrogels showed adequate release of AgNPs and LTF, with promising antimicrobial effects against both bacterial strains. The Ag-LTF-loaded hydrogel did not significantly interfere with the normal cellular functions as no alteration was detected for cell viability, migration rate, and expression of the target genes, suggesting the nontoxicity of Ag-LTF as well as the hydrogels. In conclusion, Ag-LTF-loaded genipin-cross-linked gelatin hydrogel was successfully synthesized as a new approach for fighting biofilms in infected wounds, which may be applied to accelerate healing of chronic wounds.
  5. Luh HT, Yang ST, Lu YH, Lu YC, Chan JY, Tu YK, et al.
    Clin Neuroradiol, 2023 Jun;33(2):319-325.
    PMID: 36056108 DOI: 10.1007/s00062-022-01211-9
    PURPOSE: Rete middle cerebral artery (MCA) anomaly is characterized by a web-like network of arteries involving the first MCA segment (M1) and a normal downstream MCA. The detailed composition of this anomaly and the hemodynamic impacts on cerebral perfusion are rarely addressed. The purpose of this study was to elucidate the anatomical and hemodynamic perspectives of the rete MCA anomaly.

    METHODS: From August 2020 to December 2021, 4 rete MCA anomalies were identified at Shuang Ho hospital. Clinical information, perfusion magnetic resonance (MR) imaging, and angiographic images were collected. Detailed angioarchitecture, including types of arterial feeders and extent of rete involvement, were analyzed based on three-dimensional volume-rendering reconstruction images obtained from the catheter-based angiographies.

    RESULTS: Despite their variable clinical presentations (two hemorrhage, one ischemia, and one asymptomatic), all cases shared common angiographic findings as follows: (1) the internal carotid artery did not connect directly to the rete, (2) the anterior choroidal artery (AChA) was the artery constantly supplying the rete and (3) there was a watershed zone shift toward MCA territory. The perfusion MR cerebral blood flow map was symmetric in all studied cases.

    CONCLUSION: The AChA is an artery constantly supplying the rete, which suggests that the angioarchitectural features associated with this anomaly may be the result of both congenital and acquired compensatory processes. Cerebral perfusion remains preserved at the lesion side, despite angiographic evidence of watershed zone shift. These findings will be important for making better clinical judgments about this condition.

  6. Lee YY, Saba E, Irfan M, Kim M, Chan JY, Jeon BS, et al.
    Phytomedicine, 2019 Feb 15;54:169-181.
    PMID: 30668366 DOI: 10.1016/j.phymed.2018.09.186
    BACKGROUND: Different processing conditions alter the ginseng bioactive compounds, promoting or reducing its anti-inflammatory effects. We compared black ginseng (BG) - that have been steamed 5 times - with red ginseng (RG).

    HYPOTHESIS/ PURPOSE: To compare the anti-inflammatory activities and the anti-nociceptive properties of RG and BG.

    METHODS: Nitric Oxide (NO) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay, quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR), western blot, xylene-induced ear edema, carrageenan-induced paw edema RESULTS: The ginsenoside contents were confirmed using high-performance liquid chromatography (HPLC) and has been altered through increased processing. The highest concentration of these extracts inhibited NO production to near-basal levels in lipopolysaccharide (LPS)-stimulated RAW 264.7 without exhibiting cytotoxicity. Pro-inflammatory cytokine expression at the mRNA level was investigated using qRT-PCR. Comparatively, BG exhibited better inhibition of pro-inflammatory mediators, iNOS and COX-2 and pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α. Protein expression was determined using western blot analysis and BG exhibited stronger inhibition. Xylene-induced ear edema model in mice and carrageenan-induced paw edema in rats were carried out and tested with the effects of ginseng as well as dexamethasone and indomethacin - commonly used drugs. BG is a more potent anti-inflammatory agent, possesses anti-nociceptive properties, and has a strong potency comparable to the NSAIDs.

    CONCLUSION: BG has more potent anti-inflammatory and anti-nociceptive effects due to the change in ginsenoside component with increased processing.

  7. Al-Ahdal SA, Ahmad Kayani AB, Md Ali MA, Chan JY, Ali T, Adnan N, et al.
    Int J Mol Sci, 2019 Jul 23;20(14).
    PMID: 31340481 DOI: 10.3390/ijms20143595
    We employed dielectrophoresis to a yeast cell suspension containing amyloid-beta proteins (Aβ) in a microfluidic environment. The Aβ was separated from the cells and characterized using the gradual dissolution of Aβ as a function of the applied dielectrophoretic parameters. We established the gradual dissolution of Aβ under specific dielectrophoretic parameters. Further, Aβ in the fibril form at the tip of the electrode dissolved at high frequency. This was perhaps due to the conductivity of the suspending medium changing according to the frequency, which resulted in a higher temperature at the tips of the electrodes, and consequently in the breakdown of the hydrogen bonds. However, those shaped as spheroidal monomers experienced a delay in the Aβ fibril transformation process. Yeast cells exposed to relatively low temperatures at the base of the electrode did not experience a positive or negative change in viability. The DEP microfluidic platform incorporating the integrated microtip electrode array was able to selectively manipulate the yeast cells and dissolve the Aβ to a controlled extent. We demonstrate suitable dielectrophoretic parameters to induce such manipulation, which is highly relevant for Aβ-related colloidal microfluidic research and could be applied to Alzheimer's research in the future.
  8. Chan JY, Li H, Singh O, Mahajan A, Ramasamy S, Subramaniyan K, et al.
    Urol Oncol, 2013 Nov;31(8):1553-60.
    PMID: 22561070 DOI: 10.1016/j.urolonc.2012.02.009
    OBJECTIVES: Recently, several genome-wide association studies have demonstrated a cumulative association of 5 polymorphic variants in chromosomes 8q24 and 17q with prostate cancer (CaP) risk in Caucasians, particularly those harboring aggressive clinicopathologic characteristics. The purpose of this study was to evaluate the influence of these variants on CaP susceptibility in Singaporean Asian men.
    MATERIALS AND METHODS: We performed a case-control study in 289 Chinese CaP patients and 412 healthy subjects (144 Chinese, 134 Malays, and 134 Indians), and examined the association of the 5 single nucleotide polymorphisms (SNPs) with CaP.
    RESULTS: In the healthy subjects, rs16901979 A-allele frequency was highest amongst Chinese (0.32) compared with Malays (0.13; P < 0.0001) or Indians (0.09; P < 0.0001); rs6983267 G-allele was highest in Indians (0.51) compared with Chinese (0.42; P = 0.041) or Malays (0.43; P = 0.077); whereas rs1859962 G-allele frequency was highest amongst Indians (0.56) compared with Chinese (0.40; P = 0.0002) or Malays (0.38; P < 0.0001). Individuals with the rs4430796 TT genotype were at increased CaP risk in the Chinese via a recessive model (odds ratios (OR) = 1.56, 95% CI = 1.04-2.33). Significant associations were observed for rs4430796 TT with Gleason scores of ≥ 7 (OR = 1.76, 95% CI = 1.14-2.73) and prostate-specific antigen (PSA) levels of ≥ 10 ng/ml at diagnosis (OR = 1.63, 95% CI = 1.01-2.63), as well as for rs6983267 GG with stage 3-4 CaPs (OR = 1.91, 95% CI = 1.01-3.61). A cumulative gene interaction influence on disease risk, which approximately doubled for individuals with at least 2 susceptibility genotypes, was also identified (OR = 2.18, 95% CI = 1.10-4.32).
    CONCLUSIONS: This exploratory analysis suggests that the 5 genetic variants previously described may contribute to prostate cancer risk in Singaporean men.
    KEYWORDS: Cancer; Ethnicity; Gleason; Pharmacogenetics; Polymorphism; Prostate
  9. Chan JY, Ahmad Kayani AB, Md Ali MA, Kok CK, Ramdzan Buyong M, Hoe SLL, et al.
    Electrophoresis, 2019 10;40(20):2728-2735.
    PMID: 31219180 DOI: 10.1002/elps.201800442
    This paper presents the development and experimental analysis of a curved microelectrode platform for the DEP deformation of breast cancer cells (MDA-MB-231). The platform is composed of arrays of curved DEP microelectrodes which are patterned onto a glass slide and samples containing MDA-MB-231 cells are pipetted onto the platform's surface. Finite element method is utilised to characterise the electric field gradient and DEP field. The performance of the system is assessed with MDA-MB-231 cells in a low conductivity 1% DMEM suspending medium. We applied sinusoidal wave AC potential at peak to peak voltages of 2, 5, and 10 Vpp at both 10 kHz and 50 MHz. We observed cell blebbing and cell shrinkage and analyzed the percentage of shrinkage of the cells. The experiments demonstrated higher percentage of cell shrinkage when cells are exposed to higher frequency and peak to peak voltage electric field.
  10. Chan JY, Ahmad Kayani AB, Md Ali MA, Kok CK, Yeop Majlis B, Hoe SLL, et al.
    Biomicrofluidics, 2018 Jan;12(1):011503.
    PMID: 29531634 DOI: 10.1063/1.5010158
    The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small sample volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell. Each study is critically analyzed, and the features of each platform, the performance, added functionality for clinical use, and the types of samples, used are discussed. We address the novelty of the techniques, strategies, and design configuration used in improving on existing technologies or previous studies. A summary of comparing the developmental extent of each study is made, and we conclude with a treatment of future trends and a brief summary.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links