MyMedR

Displaying publications 821 - 840 of 8478 in total

Abstract:

Sort:

Trans fatty acid content in Malaysian supermarket foods: a field-to-laboratory approach in assessing food risk

Karupaiah T, Tan HK, Ong WW, Tan CH, Sundram K

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2014;31(8):1375-84.
PMID: 24872121 DOI: 10.1080/19440049.2014.929183

The extent of industrial trans fatty acids (TFA) in the food supply is unknown in Malaysia, whilst TFA disclosure on food labels is not mandatory by Malaysian food standards. Supermarket foods such as dairy products, fats and oils, meat products, snack foods, soups, and confectionery are commonly cited to be major contributors of TFA in the diet. A consumer survey (n = 622) was used to develop a food listing of these 'high risk' foods. TFA content of high-risk foods were analysed by gas chromatography. Food samples (n = 158) were analysed and their total TFA content were compared with Malaysian Food Standards. A wide variation in TFA content within food categories was indicated. Of the foods containing TFA, many food labels did not cite TFA content or the use of partially hydrogenated vegetable oils (PHVO) as an ingredient. Hypothesised estimates of TFA intake from these supermarket foods in a sample day's menu providing 2000 kcal projected a minimum intake of 0.5 g and a maximum intake of 5.2 g TFA. This study found there was no voluntary disclosure of TFA content on food labels or identifying PHVO as an ingredient. It appears that health education targeting consumers to minimise TFA consumption is required supported by mandatory PHVO disclosure on the food label.
Immunogenic properties of recombinant ectodomain of Newcastle disease virus hemagglutinin-neuraminidase protein expressed in Escherichia coli

Wong SK, Tan WS, Omar AR, Tan CS, Yusoff K

Acta Virol., 2009;53(1):35-41.
PMID: 19301949

Hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) plays a vital role in the viral infectivity, host immunity, and disease diagnosis. A portion of the HN gene encoding the ectodomain (nt 142-1739) was cloned and expressed in Escherichia coli yielding an insoluble HN protein and a soluble NusA-HN protein containing N-utilization substance A (NusA) fusion component. Both recombinant proteins were purified and used for immunization of chickens. The recombinant HN protein induced higher antibody titers as compared to the recombinant NusA-HN protein. These antibodies were able to react in immunoblot analysis with the corresponding recombinant proteins as well as with the HN protein of NDV.
Fulltext Wandering humeral head mimicking a breast mass

Tan GJS, Tan AGS, Peh WCG

Med J Malaysia, 2008 Jun;63(2):164-5.
PMID: 18942311

A 74-year-old woman was incidentally found to have a left breast mass. The mass could not be adequately compressed to be visualized on mammography. Ultrasonography showed a heavily-calcified rounded mass in the left axillary tail of the left breast. Chest radiograph confirmed that the mass was a migrated humeral head. Remotely-displaced fracture-dislocations of the humeral head are very rare and to our knowledge, displacement into the breast, clinically mimicking a breast mass, has not been previously described.
Virus-like particles of Macrobrachium rosenbergii nodavirus produced in bacteria

Goh ZH, Tan SG, Bhassu S, Tan WS

J Virol Methods, 2011 Jul;175(1):74-9.
PMID: 21536072 DOI: 10.1016/j.jviromet.2011.04.021

Macrobrachium rosenbergii nodavirus (MrNv) infects giant freshwater prawns and causes white tail disease (WTD). The coding region of the capsid protein of MrNv was amplified with RT-PCR and cloned into the pTrcHis2-TOPO vector. The recombinant plasmid was introduced into Escherichia coli and protein expression was induced with IPTG. SDS-PAGE showed that the recombinant protein containing the His-tag and myc epitope has a molecular mass of about 46 kDa and it was detected by the anti-His antibody in Western blotting. The protein was purified using immobilized metal affinity chromatography (IMAC) and transmission electron microscopic analysis revealed that the recombinant protein assembled into virus-like particles (VLPs) with a diameter of about 30±3 nm. The size of the particles was confirmed by dynamic light scattering. Nucleic acids were extracted from the VLPs and treatment with nucleases showed that they were mainly RNA molecules. This is the first report describing the production of MrNv capsid protein in bacteria and its assembly into VLPs.
Arterial thrombosis and critical limb ischaemia in a case of nephrotic syndrome

Koh KH, Tan C, Tan S, Ngu L

Nephrology (Carlton), 2009 Sep;14(6):622.
PMID: 19712262 DOI: 10.1111/j.1440-1797.2008.01001.x
Insulin-like growth factor-1 receptor expression in the placentae of diabetic and normal pregnancies

Hayati AR, Cheah FC, Tan AE, Tan GC

Early Hum Dev, 2007 Jan;83(1):41-6.
PMID: 16750336 DOI: 10.1016/j.earlhumdev.2006.04.002

BACKGROUND: Septal hypertrophic cardiomyopathy (sHCM) is a characteristic anomaly of the infant of diabetic mother (IDM). Insulin-like growth factor-1 (IGF-1) has been identified as a mediator of tissue overgrowth and we have previously shown that maternal IGF-1 levels were significantly elevated among neonates with asymmetrical sHCM. IGF-1 does not cross the placenta; it exerts physiologic action through binding to the IGF-1 receptor (IGF-1R). Localisation and expression of IGF-1R in term diabetic pregnancies are largely unclear. We have studied IGF-1R in the placentae of diabetic and normal pregnancies and this receptor expression in association with neonates with sHCM.
METHODS: IGF-1R localization and expression in the placentae of six diabetic pregnancies associated with neonatal sHCM were compared with six each of randomly selected diabetic and normal pregnancies without neonatal sHCM by immunohistochemistry. The staining for IGF-1R in the deciduas, cytotrophoblasts, syncytiotrophoblasts and villous endothelium for these 18 samples were assessed and scored by two pathologists who were blinded to the respective diagnoses.
RESULTS: Placental IGF-1R staining was negative in the villous endothelium for all three groups. IGF-1R staining was present in deciduas, cytotrophoblasts and syncytiotrophoblasts but the staining was weaker in the entire group of infants with sHCM compared to those without sHCM.
CONCLUSIONS: IGF-1R is localized in all cell types of the placenta except in villous endothelium. Weaker placental IGF-1R staining in the placentae of diabetic pregnancies associated with sHCM suggests reduced expression of IGF-1R. This may be a down-regulatory response to elevated maternal IGF with neonatal sHCM outcome.
Inducing curricular change: Initial evaluation of outcomes

Azila NM, Tan NH, Tan CP

Med Educ, 2006 Nov;40(11):1125.
PMID: 17054624
A phage-displayed single chain variable fragment that interacts with hepatitis B core antigen: library construction, selection and diagnosis

Tan GH, Yusoff K, Seow HF, Tan WS

J Clin Virol, 2007 Jan;38(1):49-56.
PMID: 17074533

Phage display is an alternative method for constructing and selecting antibodies with desired specificity towards an antigen.
Antigenicity and immunogenicity of the immunodominant region of hepatitis B surface antigen displayed on bacteriophage T7

Tan GH, Yusoff K, Seow HF, Tan WS

J Med Virol, 2005 Dec;77(4):475-80.
PMID: 16254965

The immunodominant region of hepatitis B virus (HBV) located in the viral small surface antigen (S-HBsAg) elicits virus-neutralizing and protective antibodies. In order to develop an easy and inexpensive method to produce this region without the need for extensive purification, amino acid residues 111-156 of S-HBsAg were fused to the C-terminal end of the 10B capsid protein of T7 phage. Western blotting and ELISA confirmed the expression of the recombinant protein on the surface of the phage particles. The recombinant phage exhibited the antigenic and immunogenic characteristics of HBsAg, illustrating its potential as an immunological reagent and vaccine.
Fulltext Characterisation of beta-globin gene mutations in Malaysian children: a strategy for the control of beta-thalassaemia in a developing country

Thong MK, Tan JA, Tan KL, Yap SF

J Trop Pediatr, 2005 Dec;51(6):328-33.
PMID: 15967770 DOI: 10.1093/tropej/fmi052

beta-thalassaemia major, an autosomal recessive hemoglobinopathy, is one of the most common single gene disorders in multi-racial Malaysia. The control of beta-thalassaemia major requires a multi-disciplinary approach that includes population screening, genetic counselling, prenatal diagnosis and the option of termination of affected pregnancies. To achieve this objective, the molecular characterisation of the spectrum of beta-globin gene mutations in each of the affected ethnic groups is required. We studied 88 consecutive unrelated individuals and their respective families with beta-thalassaemia (74 beta-thalassaemia major, 12 HbE-beta-thalassaemia, 2 with HbE homozygotes) and four individuals with beta-thalassaemia trait that contributed a total 180 alleles for study. Using a 2-step molecular diagnostic strategy consisting of amplification refractory mutation system (ARMS) to identify the 8 most common mutations followed by other DNA-based diagnostic techniques, a total of 177 (98.3 per cent) of the 180 beta-thalassaemia alleles were characterised. One out of 91 (1 per cent) of the Chinese alleles, one out of 46 (2.2 per cent) Malay alleles and one out of two Indian alleles remained unknown. A 100 per cent success rate was achieved in studying the Kadazandusun community in this study. A strategy to identify beta-globin gene mutations in Malaysians with beta-thalassaemia is proposed based on this outcome.
A phage-displayed cyclic peptide that interacts tightly with the immunodominant region of hepatitis B surface antigen

Tan WS, Tan GH, Yusoff K, Seow HF

J Clin Virol, 2005 Sep;34(1):35-41.
PMID: 16087122

The surface antigen (HBsAg) of hepatitis B virus (HBV) is highly conformational and generally evokes protective humoral immune response in human. A disulfide constrained random heptapeptide library displayed on the coat protein III of filamentous bacteriophage M13 was employed to select specific ligands that interact with HBsAg subtype ad. Fusion phages carrying the amino acid sequence ETGAKPH and other related sequences were isolated. The binding site of peptide ETGAKPH was located on the immunodominant region of HBsAg. An equilibrium binding assay in solution showed that the phage binds tightly to HBsAg with a relative dissociation constant (KDrel) of 2.9+/-0.9 nM. The phage bearing this peptide has the potential to be used as a diagnostic reagent and two assays for detecting HBsAg in blood samples are described.
Fulltext Endoscopic nasopharyngectomy: the Sarawak experience

Rohaizam J, Subramaniam SK, Vikneswaran T, Tan VE, Tan TY

Med J Malaysia, 2009 Sep;64(3):213-5.
PMID: 20527270 MyJurnal

Shifting the paradigm of treatment of a locally recurrent nasopharyngeal carcinoma (NPC) from the non-surgical management to a surgical modality has always been a challenge. However, many studies on endoscopic nasopharyngectomy have proven it to be a reliable form of treatment with an excellent outcome. Since 2007, in Sarawak General Hospital, six cases of endoscopic nasopharyngectomy for locally recurrent NPC have been performed with encouraging results.
Globus pharyngeus due to a lymphangiomatous polyp arising from the tonsil

Tan CX, Yeo SW, Wong YP, Tan GC

Malays J Pathol, 2023 Aug;45(2):271-273.
PMID: 37658536

INTRODUCTION: Lymphangiomatous polyp of the tonsil is generally accepted as a hamartomatous lesion. Its differential diagnosis includes fibroepithelial polyp, squamous papilloma, angiofibroma, haemangioma, arteriovenous malformation, hamartoma and lymphangioma.
CASE REPORT: A 33-year-old man presented with 2 months history of feeling of foreign body sensation in the throat. Examination revealed a nodular red coloured polyp on the left tonsil. Histologically, the polyp was covered by squamous epithelium and is composed of numerous vascular channels containing lymphocytes and eosinophilic material, in a fibrous stroma. Immunohistochemically, the endothelial cells were positive toward CD31 and D2-40.
DISCUSSION: The characteristic histological features of a lymphangiomatous polyp are benign vascular proliferation with variable fibrous, adipose and lymphoid stromal components. Nested intraepithelial epidermotropism of lymphocytes can be observed. The vascular channels are typically thin-walled and contain eosinophilic proteinaceous material and lymphocytes. There is no reported incidence of recurrent or malignant transformation.
Fulltext Online grocery shopping intention: Elderly's perspective in Malaysia

Yap YY, Tan SH, Tan SK, Choon SW

Heliyon, 2023 Oct;9(10):e20827.
PMID: 37916123 DOI: 10.1016/j.heliyon.2023.e20827

PURPOSE: This study investigates the factors associated with the elderly's intention to use OGS. Building on the Technology Acceptance Model, we propose several elderly-specific and functional-ageing constructs related to the perceived ease of use and usefulness of OGS.
METHODS: The questionnaire was distributed physically and digitally to non-OGS users aged above 60, living in the Klang Valley, Malaysia, using a non-probability sampling approach. A total of 302 data were analysed using PLS structural equation modelling.
RESULTS: The findings indicate that perceived ease of use, functional ability, life-course events, and digital literacy are associated with the elderly's perception of OGS's usefulness, while life-course events, digital literacy, technology anxiety, and facilitating conditions are associated with the perceived ease of use.
CONCLUSION: This study contributes to the OGS literature by addressing ageing complexities with OGS adoption among the elderly population, thereby offering insights for marketers and the government to tailor services and provide relevant support.
Virus Propagation and Cell-Based Colorimetric Quantification

Tan JY, Wong JE, Zainal N, AbuBakar S, Tan KK

J Vis Exp, 2023 Apr 07.
PMID: 37092849 DOI: 10.3791/64578

Zika virus (ZIKV) is a mosquito-borne virus belonging to the genus Flavivirus. ZIKV infection has been associated with congenital brain abnormalities and potentially Guillain-Barré syndrome in adults. Research on ZIKV to understand the disease mechanisms is important to facilitate vaccine and treatment development. The method of quantifying viruses is crucial and fundamental in the field of virology. The focus forming assay (FFA) is a virus quantification assay that detects the viral antigen with antibodies and identifies the infection foci of cells using the peroxidase immunostaining technique. The current study describes the virus propagation and quantification protocol using both 24-well and 96-well (high throughput) formats. Compared with other similar studies, this protocol has further described foci size optimization, which can serve as a guide to expand the use of this assay for other viruses. Firstly, ZIKV propagation is performed in Vero cells for 3 days. The culture supernatant containing ZIKV is harvested and quantitated using the FFA. Briefly, the virus culture is inoculated onto Vero cells and incubated for 2-3 days. Foci formation is then determined after optimized staining processes, including cell fixation, permeabilization, blocking, antibody binding, and incubation with peroxidase substrate. The stained virus foci are visualized using a stereo microscope (manual counting in 24-well format) or software analyzer (automated counting in 96-well format). The FFA provides reproducible, relatively fast results (3-4 days) and is suitable to be used for different viruses, including non-plaque-forming viruses. Subsequently, this protocol is useful for the study of ZIKV infection and could be used to detect other clinically important viruses.
Next-generation viral nanoparticles for targeted delivery of therapeutics: Fundamentals, methods, biomedical applications, and challenges

Tan JS, Jaffar Ali MNB, Gan BK, Tan WS

Expert Opin Drug Deliv, 2023;20(7):955-978.
PMID: 37339432 DOI: 10.1080/17425247.2023.2228202

INTRODUCTION: Viral nanoparticles (VNPs) are virus-based nanocarriers that have been studied extensively and intensively for biomedical applications. However, their clinical translation is relatively low compared to the predominating lipid-based nanoparticles. Therefore, this article describes the fundamentals, challenges, and solutions of the VNP-based platform, which will leverage the development of next-generation VNPs.
AREAS COVERED: Different types of VNPs and their biomedical applications are reviewed comprehensively. Strategies and approaches for cargo loading and targeted delivery of VNPs are examined thoroughly. The latest developments in controlled release of cargoes from VNPs and their mechanisms are highlighted too. The challenges faced by VNPs in biomedical applications are identified, and solutions are provided to overcome them.
EXPERT OPINION: In the development of next-generation VNPs for gene therapy, bioimaging and therapeutic deliveries, focus must be given to reduce their immunogenicity, and increase their stability in the circulatory system. Modular virus-like particles (VLPs) which are produced separately from their cargoes or ligands before all the components are coupled can speed up clinical trials and commercialization. In addition, removal of contaminants from VNPs, cargo delivery across the blood brain barrier (BBB), and targeting of VNPs to organelles intracellularly are challenges that will preoccupy researchers in this decade.
Fulltext Complete Genome Sequence of Cedecea neteri Strain SSMD04, a Bacterium Isolated from Pickled Mackerel Sashimi

Chan KG, Tan KH, Yin WF, Tan JY

Genome Announc, 2014;2(6).
PMID: 25523782 DOI: 10.1128/genomeA.01339-14

We report here the complete genome sequence of C. neteri SSMD04, a strain isolated from pickled mackerel sashimi, sequenced by third-generation sequencing technology. To the best of our knowledge, this is the first documentation that reports the complete genome of Cedecea neteri.
Proteomic characterization of venom of the medically important Southeast Asian Naja sumatrana (Equatorial spitting cobra)

Yap MK, Fung SY, Tan KY, Tan NH

Acta Trop, 2014 May;133:15-25.
PMID: 24508616 DOI: 10.1016/j.actatropica.2014.01.014

The proteome of Naja sumatrana (Equatorial spitting cobra) venom was investigated by shotgun analysis and a combination of ion-exchange chromatography and reverse phase HPLC. Shotgun analysis revealed the presence of 39 proteins in the venom while the chromatographic approach identified 37 venom proteins. The results indicated that, like other Asiatic cobra venoms, N. sumatrana contains large number of three finger toxins and phospholipases A2, which together constitute 92.1% by weight of venom protein. However, only eight of the toxins can be considered as major venom toxins. These include two phospholipases A2, three neurotoxins (two long neurotoxins and a short neurotoxin) and three cardiotoxins. The eight major toxins have relative abundance of 1.6-27.2% venom proteins and together account for 89.8% (by weight) of total venom protein. Other venom proteins identified include Zn-metalloproteinase-disintegrin, Thaicobrin, CRISP, natriuretic peptide, complement depleting factors, cobra venom factors, venom nerve growth factor and cobra serum albumin. The proteome of N. sumatrana venom is similar to proteome of other Asiatic cobra venoms but differs from that of African spitting cobra venom. Our results confirm that the main toxic action of N. sumatrana venom is neurotoxic but the large amount of cardiotoxins and phospholipases A2 are likely to contribute significantly to the overall pathophysiological action of the venom. The differences in toxin distribution between N. sumatrana venom and African spitting cobra venoms suggest possible differences in the pathophysiological actions of N. sumatrana venom and the African spitting cobra venoms, and explain why antivenom raised against Asiatic cobra venom is not effective against African spitting cobra venoms.
Fulltext Cytotoxic data of 14-deoxy-11, 12-didehydroandrographolide (14-DDA), double transfection and DDIT3 silencing data in T-47D breast carcinoma cells

Tan HK, Tengku Muhammad TS, Tan ML

Data Brief, 2016 Jun;7:1506-10.
PMID: 27182548 DOI: 10.1016/j.dib.2016.04.046

The data presented in this article are related to the research article entitled "14-deoxy-11,12-didehydroandrographolide induces DDIT3-dependent endoplasmic reticulum stress-mediated autophagy in T-47D breast carcinoma cells", which the mechanistic toxicology properties of 14-deoxy-11,12-didehydroandrographolide (14-DDA) were investigated (Tan et al., 2016 [1]). This article describes the derivation of cytotoxic parameters of 14-DDA, cell viability data after double transfection and DDIT3 silencing in T-47D cells.
Fulltext Novel calcium infusion regimen after parathyroidectomy for renal hyperparathyroidism

Tan JH, Tan HC, Loke SC, Arulanantham SA

Nephrology (Carlton), 2017 Apr;22(4):308-315.
PMID: 26952689 DOI: 10.1111/nep.12761

AIM: Calcium infusion is used after parathyroid surgery for renal hyperparathyroidism to treat postoperative hypocalcaemia. We compared a new infusion regimen to one commonly used in Malaysia based on 2003 K/DOQI guidelines.
METHODS: Retrospective data on serum calcium and infusion rates was collected from 2011-2015. The relationship between peak calcium efflux (PER) and time was determined using a scatterplot and linear regression. A comparison between regimens was made based on treatment efficacy (hypocalcaemia duration, total infusion amount and time) and calcium excursions (outside target range, peak and trough calcium) using bar charts and an unpaired t-test.
RESULTS: Fifty-one and 34 patients on the original and new regimens respectively were included. Mean PER was lower (2.16 vs 2.56 mmol/h; P = 0.03) and occurred earlier (17.6 vs 23.2 h; P = 0.13) for the new regimen. Both scatterplot and regression showed a large correlation between PER and time (R-square 0.64, SE 1.53, P

Filters

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

External Links