Displaying publications 1 - 20 of 162 in total

Abstract:
Sort:
  1. Zhong M, Lin B, Pathak JL, Gao H, Young AJ, Wang X, et al.
    Front Med (Lausanne), 2020;7:580796.
    PMID: 33363183 DOI: 10.3389/fmed.2020.580796
    Background: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that mainly transfers from human to human via respiratory and gastrointestinal routes. The S-glycoprotein in the virus is the key factor for the entry of SARS-CoV-2 into the cell, which contains two functional domains: S1 is an angiotensin-converting enzyme 2 (ACE2) receptor binding domain, and S2 is necessary for fusion of the coronavirus and cell membranes. Moreover, it has been reported that ACE2 is likely to be the receptor for SARS-CoV-2. In addition, mRNA level expression of Furin enzyme and ACE2 receptor had been reported in airway epithelia, cardiac tissue, and enteric canals. However, the expression patterns of ACE2 and Furin in different cell types of oral tissues are still unclear. Methods: In order to investigate the potential infective channel of the new coronavirus via the oropharyngeal cavity, we analyze the expression of ACE2 and Furin in human oral mucosa using the public single-cell sequence datasets. Furthermore, immunohistochemistry was performed in mucosal tissue from different oral anatomical sites to confirm the expression of ACE2 and Furin at the protein level. Results: The bioinformatics results indicated the differential expression of ACE2 and Furin on epithelial cells from different oral anatomical sites. Immunohistochemistry results revealed that both the ACE2-positive and Furin-positive cells in the target tissues were mainly positioned in the epithelial layers, partly expressed in fibroblasts, further confirming the bioinformatics results. Conclusions: Based on these findings, we speculated that SARS-CoV-2 could invade oral mucosal cells through two possible routes: binding to the ACE2 receptor and fusion with cell membrane activated by Furin protease. Our results indicated that oral mucosa tissues are susceptible to SARS-CoV-2 that could facilitate COVID-19 infection via respiratory and fecal-oral routes.
  2. Letchumanan P, Ng HJ, Lee LH, Thumboo J
    Rheumatology (Oxford), 2009 Apr;48(4):399-403.
    PMID: 19202160 DOI: 10.1093/rheumatology/ken510
    To compare the clinical presentation, response to therapy and outcome of thrombotic thrombocytopenic purpura (TTP) in an inception cohort of patients with and without SLE.
  3. Lawrencia D, Wong SK, Low DYS, Goh BH, Goh JK, Ruktanonchai UR, et al.
    Plants (Basel), 2021 Jan 26;10(2).
    PMID: 33530608 DOI: 10.3390/plants10020238
    Rising world population is expected to increase the demand for nitrogen fertilizers to improve crop yield and ensure food security. With existing challenges on low nutrient use efficiency (NUE) of urea and its environmental concerns, controlled release fertilizers (CRFs) have become a potential solution by formulating them to synchronize nutrient release according to the requirement of plants. However, the most significant challenge that persists is the "tailing" effect, which reduces the economic benefits in terms of maximum fertilizer utilization. High materials cost is also a significant obstacle restraining the widespread application of CRF in agriculture. The first part of this review covers issues related to the application of conventional fertilizer and CRFs in general. In the subsequent sections, different raw materials utilized to form CRFs, focusing on inorganic and organic materials and synthetic and natural polymers alongside their physical and chemical preparation methods, are compared. Important factors affecting rate of release, mechanism of release and mathematical modelling approaches to predict nutrient release are also discussed. This review aims to provide a better overview of the developments regarding CRFs in the past ten years, and trends are identified and analyzed to provide an insight for future works in the field of agriculture.
  4. Supramaniam J, Low DYS, Wong SK, Tan LTH, Leo BF, Goh BH, et al.
    Int J Mol Sci, 2021 May 28;22(11).
    PMID: 34071337 DOI: 10.3390/ijms22115781
    Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8-10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.
  5. Wang S, Liu F, Tan KS, Ser HL, Tan LT, Lee LH, et al.
    J Cell Mol Med, 2020 01;24(1):722-736.
    PMID: 31680470 DOI: 10.1111/jcmm.14780
    Evidence demonstrates that M1 macrophage polarization promotes inflammatory disease. Here, we discovered that (R)-salbutamol, a β2 receptor agonist, inhibits and reprograms the cellular metabolism of RAW264.7 macrophages. (R)-salbutamol significantly inhibited LPS-induced M1 macrophage polarization and downregulated expressions of typical M1 macrophage cytokines, including monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α). Also, (R)-salbutamol significantly decreased the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and reactive oxygen species (ROS), while increasing the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. In contrast, (S)-salbutamol increased the production of NO and ROS. Bioenergetic profiles showed that (R)-salbutamol significantly reduced aerobic glycolysis and enhanced mitochondrial respiration. Untargeted metabolomics analysis demonstrated that (R)-salbutamol modulated metabolic pathways, of which three metabolic pathways, namely, (a) phenylalanine metabolism, (b) the pentose phosphate pathway and (c) glycerophospholipid metabolism were the most noticeably impacted pathways. The effects of (R)-salbutamol on M1 polarization were inhibited by a specific β2 receptor antagonist, ICI-118551. These findings demonstrated that (R)-salbutamol inhibits the M1 phenotype by downregulating aerobic glycolysis and glycerophospholipid metabolism, which may propose (R)-salbutamol as the major pharmacologically active component of racemic salbutamol for the treatment of inflammatory diseases and highlight the medicinal value of (R)-salbutamol.
  6. Lin B, Ser HL, Wang L, Li J, Chan KG, Lee LH, et al.
    Int J Mol Sci, 2023 Feb 28;24(5).
    PMID: 36902078 DOI: 10.3390/ijms24054648
    Matrix metalloproteinase-12 (MMP12), or macrophage metalloelastase, plays important roles in extracellular matrix (ECM) component degradation. Recent reports show MMP12 has been implicated in the pathogenesis of periodontal diseases. To date, this review represents the latest comprehensive overview of MMP12 in various oral diseases, such as periodontitis, temporomandibular joint dysfunction (TMD), orthodontic tooth movement (OTM), and oral squamous cell carcinoma (OSCC). Furthermore, the current knowledge regarding the distribution of MMP12 in different tissues is also illustrated in this review. Studies have implicated the association of MMP12 expression with the pathogenesis of several representative oral diseases, including periodontitis, TMD, OSCC, OTM, and bone remodelling. Although there may be a potential role of MMP12 in oral diseases, the exact pathophysiological role of MMP12 remains to be elucidated. Understanding the cellular and molecular biology of MMP12 is essential, as MMP12 could be a potential target for developing therapeutic strategies targeting inflammatory and immunologically related oral diseases.
  7. Ang WS, Law JW, Letchumanan V, Hong KW, Wong SH, Ab Mutalib NS, et al.
    Foods, 2023 Jun 26;12(13).
    PMID: 37444223 DOI: 10.3390/foods12132485
    A new next-generation probiotic, Christensenella minuta was first discovered in 2012 from healthy human stool and described under the phylum Firmicutes. C. minuta is a subdominant commensal bacterium with highly heritable properties that exhibits mutual interactions with other heritable microbiomes, and its relative abundance is positively correlated with the lean host phenotype associated with a low BMI index. It has been the subject of numerous studies, owing to its potential health benefits. This article reviews the evidence from various studies of C. minuta interventions using animal models for managing metabolic diseases, such as obesity, inflammatory bowel disease, and type 2 diabetes, characterized by gut microbiota dysbiosis and disruption of host metabolism. Notably, more studies have presented the complex interaction between C. minuta and host metabolism when it comes to metabolic health. Therefore, C. minuta could be a potential candidate for innovative microbiome-based biotherapy via fecal microbiota transplantation or oral administration. However, the detailed underlying mechanism of action requires further investigation.
  8. Gan CC, Tan RY, Cheong MA, Pang SC, Tng RKA, Tan CW, et al.
    J Vasc Access, 2023 Sep 19.
    PMID: 37726986 DOI: 10.1177/11297298231194102
    BACKGROUND: This study aims to evaluate the safety and efficacy of a short-term, low dose, weight-based subcutaneous enoxaparin protocol (SEP) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis.

    METHODS: Prospective follow-up of 25 patients who presented to a tertiary institution with recurrent AV access thrombosis and treated with anticoagulation according to SEP following successful thrombectomy. Patency and safety outcomes of SEP were studied.

    RESULTS: The participants were 66.4 ± 10.2 years old and predominantly male (60%) and of Chinese ethnicity (72%). The AV accesses had a median age of 1.4 (0.6, 5.6) years with 60% being non-autogenous arteriovenous access while 40% were autogenous arteriovenous access. Thrombolytic agents (urokinase (72%) or alteplase (28%)) were used in all procedures while adjunct thrombectomy device was used in only four procedures. The mean dose of enoxaparin was 36.0 ± 8.2 mg or 0.64 ± 0.1 mg/kg/day for a mean duration 30.0 days (Interquartile range: 27.5, 31.0). One patient developed minor bleeding episode. Kaplan-Meier analysis demonstrated that the mean thrombosis-free survival pre- versus post-SEP adoption was 27.3 (95% CI 17.9-36.7) versus 183.5 (95% CI 100.1-266.9) days (p 

  9. Nasri C, Halabi Y, Hajib A, Choukri H, Harhar H, Lee LH, et al.
    Sci Rep, 2023 Dec 20;13(1):22767.
    PMID: 38123687 DOI: 10.1038/s41598-023-50119-y
    Eight Moroccan avocado varieties were analyzed for their nutritional composition and physicochemical properties. The nutritional contents of the sample were determined through the evaluation of the moisture, oil, ash, protein, and carbohydrate contents, and energy value calculation. Additionally, macroelements (Ca, Mg, and Na) and microelements (Fe, Zn, Cu, and Mn) were determined in the mineral profile. Oils were examined also for their fatty acid, phytosterol, and tocopherol profiles. As a result of the study, the avocado presents significant differences between the eight studied varieties (p 
  10. Khan TM, Wu DB, Goh BH, Lee LH, Alhafez AA, Syed Sulaiman SA
    Sci Rep, 2016 11 08;6:36555.
    PMID: 27824127 DOI: 10.1038/srep36555
    A prospective, observational, longitudinal study was conducted to assess the effectiveness of 75 mg pregabalin (PG) post-hemodialysis (pHD) for treatment-resistant uremic pruritus (UP). A total of forty-five patients completed the entire six week follow-up. At the baseline assessment, the majority of the patients were distressed by the UP frequency and intensity. Sleep (mean = 3.30 ± 1.1), leisure/social activities (mean = 2.90 ± 0.80) and distribution (mean = 2.92 ± 0.34) were the three domains that were primarily effected by the UP. Overall, further reduction in the 5D-itching scale (IS) was noted at day 42, which confirmed a sustained (B = -12.729, CI -13.257 to -12.201, p 
  11. Duangjai A, Nuengchamnong N, Lee LH, Goh BH, Saokaew S, Suphrom N
    Nat Prod Res, 2019 May;33(10):1491-1494.
    PMID: 29258345 DOI: 10.1080/14786419.2017.1416386
    Azadirachta indica has long been used in traditional medicine. This study focused on isolation and characterisation of active ingredients in the extract, its fractions (NF-EA, NF-AQ, NF-G) and its effect on the cholesterol absorption activity. The NF-EA fraction was identified by marker compounds by LC-ESI-QTOF/MS. Cholesterol absorption activity was performed by measuring the solubility and size of cholesterol micelles. The intestinal motility was also examined by isolated rat's ileum to test the contraction. The extract and its fractions consist of flavonoids and phenolic compounds, like quercetin, kaempferol and myricetin. We found that A. indica extract and NF-EA increase cholesterol micelles size, while the extract, NF-AQ, myricetin and quercetin, reduced the solubility of cholesterol in micelles. The extract and quercetin inhibited the contraction induced by KCl up to 29 and 18%, respectively, and also decreased CaCl2-induced contraction. This finding is in support to traditional uses of A. indica as cholesterol-lowering agents and regulator of gastrointestinal motility.
  12. Khoo CH, Cheah YK, Lee LH, Sim JH, Salleh NA, Sidik SM, et al.
    Antonie Van Leeuwenhoek, 2009 Nov;96(4):441-57.
    PMID: 19565351 DOI: 10.1007/s10482-009-9358-z
    The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70% of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration of DNA 0.8 pg microl(-1). This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies.
  13. Rayanakorn A, Goh BH, Lee LH, Khan TM, Saokaew S
    Sci Rep, 2018 09 06;8(1):13358.
    PMID: 30190575 DOI: 10.1038/s41598-018-31598-w
    Streptococcus suis (S. suis) is a gram-positive bacterial pathogen in pigs which can cause serious infections in human including meningitis, and septicaemia resulting in serious complications. There were discrepancies between different data and little is known concerning associated risk factors of S. suis. A systematic review and meta-analysis was conducted to investigate on S. suis infection risk factors in human. We searched eight relevant databases using the MeSH terms "Streptococcus suis" OR "Streptococcus suis AND infection" limited in human with no time nor language restriction. Out of 4,999 articles identified, 32 and 3 studies were included for systematic review and meta-analysis respectively with a total of 1,454 Streptococcus suis cases reported. S. suis patients were generally adult males and the elderly. The mean age ranged between 37 to 63 years. Meningitis was the most common clinical manifestation, and deafness was the most common sequelae found among survivors followed by vestibular dysfunction. Infective endocarditis was also noted as among the most common clinical presentations associated with high mortality rate in a few studies. Meta-analyses categorized by type of control groups (community control, and non-S. suis sepsis) were done among 850 participants in 3 studies. The combined odd ratios for studies using community control groups and non-S. Suis sepsis as controls respectively were 4.63 (95% CI 2.94-7.29) and 78.00 (95% CI 10.38-585.87) for raw pork consumption, 4.01 (95% CI 2.61-6.15) and 3.03 (95% CI 1.61-5.68) for exposure to pigs or pork, 11.47, (95% CI 5.68-23.14) and 3.07 (95% CI 1.81-5.18) for pig-related occupation and 3.56 (95% CI 2.18-5.80) and 5.84 (95% CI 2.76-12.36) for male sex. The results were found to be significantly associated with S. suis infection and there was non-significant heterogeneity. History of skin injury and underlying diseases were noted only a small percentage in most studies. Setting up an effective screening protocol and public health interventions would be effective to enhance understanding about the disease.
  14. Duangjai A, Goh BH, Lee LH, Saokaew S
    J Tradit Complement Med, 2018 Oct;8(4):515-520.
    PMID: 30302332 DOI: 10.1016/j.jtcme.2018.01.003
    Azadirachta indica A. Juss var. siamensis Valeton or commonly known as Siamese neem is one of the most well-known plant in traditional Ayurvedic medicine. The aim of the present study was to investigate the relaxant effects of A. indica on isolated rat ileum contractions and its potential underlying mechanisms involved. The isometric contractions of ileum segments were investigated in organ baths for spontaneous activity and response to aqueous extract of Siamese neem flower (SNF). The spasmolytic action of the extract was also assessed on contraction induced by acetylcholine and high potassium. Our findings indicate that cumulative concentrations of SNF aqueous extract induced relaxant effect on spontaneous rat ileum contractions. The extract has also suppressed the cumulative concentration response curve for acetylcholine and pottasium ions-induced contraction. The presence and absence of propranol (antagonist of β-adrenergic receptor) and l-Name (antagonist of nitric oxide synthase) in SNF aqeous extract co-treatment demonstrated no significant different in term of contraction activity when compared to SNF extract treatment alone. The treatment of SNF extract caused a significant inhibition in tissue contraction stimulated by accumulation of calcium ions. Our results showed the relaxant effect of SNF aqueous extract on the isolated rat ileum. In short, the SNF aqueous extract exhibited an inhibitory effect on the spontaneous ileum contactions particularly on the contraction stimulated by acetylcholine and high potassium. The observed effect might acted through the modulation of calcium channels. This findings provide a pharmacological basis for the traditional use of SNF for the treatment of gastrointestinal spasms.
  15. Goonewardene ST, Tang C, Tan LT, Chan KG, Lingham P, Lee LH, et al.
    Front Pediatr, 2019;7:339.
    PMID: 31456997 DOI: 10.3389/fped.2019.00339
    Nephrotic syndrome affects both children and adults. Idiopathic nephrotic syndrome is reported to be one of the most frequent renal pathologies in childhood. Nephrotic children are at high risk for severe pneumococcal infections as one of the life-threatening complications of nephrotic syndrome due to involvement of the immunosuppressive regimen and the acquired immune deficiency induced by nephrotic syndrome including decreased plasma IgG and low complement system components. Aiming to prevent pneumococcal infection is of paramount importance especially in this era of ever-increasing pneumococcal resistance to penicillins and cephalosporins. The pneumococcal vaccines currently available are inactivated vaccines-the two main forms in use are polysaccharide vaccines and conjugated vaccines. However, the data supporting the use of these vaccines and to guide the timing and dosage recommendations is still limited for nephrotic children. Thus, this review discusses the evidences of immunogenicity and safety profile of both vaccinations on nephrotic patients as well as the effect of nephrotic syndrome treatment on vaccine seroresponses.
  16. Rayanakorn A, Katip W, Lee LH, Oberdorfer P
    BMJ Case Rep, 2019 Feb 26;12(2).
    PMID: 30814105 DOI: 10.1136/bcr-2018-228501
    Streptococcus suis is a Gram-positive cocci bacterium that are found mainly in pigs and can be transmitted to human through pigs or pork exposure. The disease is mainly found among occupations involving swine contact in western countries whereas in Asia the disease is usually contracted through raw pork consumption. In this case report, we present a case of a middle-aged Thai man who acquired the infection from raw pork consumption. He presented with endogenous endophthalmitis with infective spondylodiscitis, sepsis and meningitis and later developed blindness of the right eye and permanent bilateral hearing loss disseminated from S. suis infection. Our report suggests that S. suis infection be considered as a causative factor in patient presenting with established clinical symptoms and predisposing factors. Cultural habit of eating raw pork should be taken into account especially in Asian countries.
  17. Tieng FYF, Abdullah-Zawawi MR, Md Shahri NAA, Mohamed-Hussein ZA, Lee LH, Mutalib NA
    Brief Bioinform, 2023 Nov 22;25(1).
    PMID: 38040490 DOI: 10.1093/bib/bbad421
    RNA biology has risen to prominence after a remarkable discovery of diverse functions of noncoding RNA (ncRNA). Most untranslated transcripts often exert their regulatory functions into RNA-RNA complexes via base pairing with complementary sequences in other RNAs. An interplay between RNAs is essential, as it possesses various functional roles in human cells, including genetic translation, RNA splicing, editing, ribosomal RNA maturation, RNA degradation and the regulation of metabolic pathways/riboswitches. Moreover, the pervasive transcription of the human genome allows for the discovery of novel genomic functions via RNA interactome investigation. The advancement of experimental procedures has resulted in an explosion of documented data, necessitating the development of efficient and precise computational tools and algorithms. This review provides an extensive update on RNA-RNA interaction (RRI) analysis via thermodynamic- and comparative-based RNA secondary structure prediction (RSP) and RNA-RNA interaction prediction (RIP) tools and their general functions. We also highlighted the current knowledge of RRIs and the limitations of RNA interactome mapping via experimental data. Then, the gap between RSP and RIP, the importance of RNA homologues, the relationship between pseudoknots, and RNA folding thermodynamics are discussed. It is hoped that these emerging prediction tools will deepen the understanding of RNA-associated interactions in human diseases and hasten treatment processes.
Filters
Contact Us

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

External Links