MyMedR

Displaying publications 41 - 60 of 138 in total

Abstract:

Sort:

Fulltext Validation of a multiplex RT-PCR assay for screening significant oncogene fusion transcripts in children with acute lymphoblastic leukaemia

Ariffin H, Chen SP, Wong HL, Yeoh A

Singapore Med J, 2003 Oct;44(10):517-20.
PMID: 15024455

In childhood acute lymphoblastic leukaemia (ALL), cytogenetics play an important role in diagnosis, allocation of treatment and prognosis. Conventional cytogenetic analysis, involving mainly karyotyping in our experience, has not been successful in a large proportion of cases due to inadequate metaphase spreads and poor chromosome morphology. Our aim is to develop a highly sensitive and specific method to screen simultaneously for the four most frequent fusion transcripts resulting from specific chromosomal translocations, namely, both the CML- and ALLtype BCR-ABL transcripts of t(9;22), E2A-PBX1 transcript of t(1;19), the MLL-AF4 transcript of t(4;11) and TEL-AML1 (also termed ETV6-CBFA2) of the cryptic t(12;21). A multiplex reverse transcription polymerase chain reaction protocol (RT-PCR) was developed and tested out on archival bone marrow samples and leukaemia cell lines. In all samples with a known translocation detected by cytogenetic techniques, the same translocation was identified by the multiplex-PCR assay. Multiplex RT-PCR assay is an effective, sensitive, accurate and cost-effective diagnostic tool which can improve our ability to accurately and rapidly risk-stratify patients with childhood ALL.
Fulltext Intraabdominal desmoplastic small round cell tumour in an 11-year-old boy

Ariffin H, Ariffin WA, Wong KT, Ramanujam TM, Lin HP

Singapore Med J, 1997 Apr;38(4):169-71.
PMID: 9269398

A case of desmoplastic small round cell tumour (DSRCT) is presented. This aggressive and rare neoplasm predominantly affects males and is almost exclusively intraabdominal in location. It is unique in that neural, mesenchymal and epithelial markers are co-expressed. Despite multi-modal therapy, the prognosis is extremely poor. The present report details the clinical features and typical pathological findings of DSRCT in an 11-year-old boy, who succumbed to the disease 16 months after diagnosis despite multiple chemotherapeutic regimes.
Fulltext Successful treatment of Candida albicans endocarditis in a child with leukemia--a case report and review of the literature

Ariffin H, Ariffin W, Tharam S, Omar A, de Bruyne J, Lin HP

Singapore Med J, 1999 Aug;40(8):533-6.
PMID: 10572495

Candida species is now being increasingly recognised as an important cause of endocarditis especially in immunocompromised patients. A case of Candida albicans endocarditis in a child with acute lymphoblastic leukemia (ALL) is reported. The child did not have a central venous catheter at any time. Treatment consisted of intravenous amphotericin B and fluconazole for 3 weeks followed by oral fluconazole for 2 weeks. No surgical resection was necessary. We highlight here the importance of echocardiography in the management of prolonged febrile neutropenia and discuss the dilemma of continuing chemotherapy in such patients.
Fulltext Evaluation of two short tandem repeat multiplex systems for post-haematopoietic stem cell transplantation chimerism analysis

Ariffin H, Daud SS, Mohamed Z, Ibrahim K, Lee TF, Chong LA

Singapore Med J, 2007 Apr;48(4):333-7.
PMID: 17384881

The follow-up of chimerism status after allogeneic haematopoietic stem cell transplantation (HSCT) is essential to predict successful engraftment to assess the development of graft-versus-host disease, graft rejection and disease relapse. Analysis of short tandem repeats (STR) via polymerase chain reaction is frequently used for chimerism determination. However, most commercially-available kits have been designed for forensic purposes and may not be optimal for chimerism analysis. The present study aims to identify suitable STR markers for patient-donor pairs of predominantly Malay and Chinese ethnicity using two commercially-available forensic kits.
Fulltext GATA1 mutations in a cohort of Malaysian children with Down syndrome-associated myeloid disorder

Lum SH, Choong SS, Krishnan S, Mohamed Z, Ariffin H

Singapore Med J, 2016 Jun;57(6):320-4.
PMID: 27353457 DOI: 10.11622/smedj.2016106

INTRODUCTION: Children with Down syndrome (DS) are at increased risk of developing distinctive clonal myeloid disorders, including transient abnormal myelopoiesis (TAM) and myeloid leukaemia of DS (ML-DS). TAM connotes a spontaneously resolving congenital myeloproliferative state observed in 10%-20% of DS newborns. Following varying intervals of apparent remission, a proportion of children with TAM progress to develop ML-DS in early childhood. Therefore, TAM and ML-DS represent a biological continuum. Both disorders are characterised by recurring truncating somatic mutations of the GATA1 gene, which are considered key pathogenetic events.
METHODS: We herein report, to our knowledge, the first observation on the frequency and nature of GATA1 gene mutations in a cohort of Malaysian children with DS-associated TAM (n = 9) and ML-DS (n = 24) encountered successively over a period of five years at a national referral centre.
RESULTS: Of the 29 patients who underwent GATA1 analysis, GATA1 mutations were observed in 15 (51.7%) patients, including 6 (75.0%) out of 8 patients with TAM, and 9 (42.9%) of 21 patients with ML-DS. All identified mutations were located in exon 2 and the majority were sequence-terminating insertions or deletions (66.7%), including several hitherto unreported mutations (12 out of 15).
CONCLUSION: The low frequency of GATA1 mutations in ML-DS patients is unusual and potentially indicates distinctive genomic events in our patient cohort.
Fulltext T-cell-replete haploidentical bone marrow transplantation for X-linked severe combined immunodeficiency

Ariffin H, Chew KS, Jawin V, Thavagnanam S

Singapore Med J, 2020 May;61(5):284-285.
PMID: 30128577 DOI: 10.11622/smedj.2018101
Fulltext Manipulating the Gut Microbiome as a Therapeutic Strategy to Mitigate Late Effects in Childhood Cancer Survivors

Oh L, Ab Rahman S, Dubinsky K, Azanan MS, Ariffin H

Technol Cancer Res Treat, 2023;22:15330338221149799.
PMID: 36624625 DOI: 10.1177/15330338221149799

Recent studies have identified causal links between altered gut microbiome, chronic inflammation, and inflammation-driven conditions such as diabetes and cardiovascular disease. Childhood cancer survivors (CCS) show late effects of therapy in the form of inflammaging-related disorders as well as microbial dysbiosis, supporting a hypothesis that the conditions are interconnected. Given the susceptibility of the gut microbiome to alteration, a number of therapeutic interventions have been investigated for the treatment of inflammatory conditions, though not within the context of cancer survivorship in children and adolescents. Here, we evaluate the potential for these interventions, which include probiotic supplementation, prebiotics/fiber-rich diet, exercise, and fecal microbiota transplantation for prevention and treatment of cancer treatment-related microbial dysbiosis in survivors. We also make recommendations to improve adherence and encourage long-term lifestyle changes for maintenance of healthy gut microbiome in CCS as a potential strategy to mitigate treatment-related late effects.
Fulltext Emerging trends in the appliance of ultrasonic technology for valorization of agricultural residue into versatile products

Sabaruddin FA, Megashah LN, Shazleen SS, Ariffin H

Ultrason Sonochem, 2023 Oct;99:106572.
PMID: 37696213 DOI: 10.1016/j.ultsonch.2023.106572

The utilization of agricultural residues to obtain biocompounds of high-added value has significantly increased in the past decades. The conversion of agro-based residues into valuable products appears to be an economically efficient, environment-friendly, and protracted waste management practice. The implementation of ultrasonic technologies in the conversion of value-added goods from agricultural waste materials through pre-treatment and valorization processes has imparted many advantageous effects including rapid processing, effective process performance, minimization of processing steps, minimal dependency on harmful chemicals, and an increased yield and properties of bio-products. To further enliven the literature and inspire new research investigations, this review covers the comprehensive work including theoretical principles, processes, and potential benefits of ultrasonic treatment technologies to assist the production of bio-products which emphasize the extraction yield and the characteristic of the end-product extracted from agriculture residues. A detailed evaluation of these methods and key aspects impacting their performance as well as the features and shortcomings of each ultrasound-assisted approach is also discussed. This review also addressed some of the challenges associated with using ultrasonic irradiation and proposed several potential techniques to maximize productivity. Understanding the concept of ultrasonication technique allow the academician and industrial practitioners to explore the possibility of applying a greener and sustainable approach of biomass extraction to be translated into higher scale production of commercial products.
Physical Inactivity as an Early Sign of Frailty in Young Adult Survivors of Childhood Acute Lymphoblastic Leukemia

Chua LL, Azanan MS, Oh L, Ariffin H

J Pediatr Hematol Oncol, 2023 Jul 01;45(5):e560-e566.
PMID: 36730635 DOI: 10.1097/MPH.0000000000002586

Young adult survivors of childhood leukemia have been reported with increased likelihood of age-related comorbidities compared with the general population. We compared the prevalence of frailty in young adult survivors of childhood acute lymphoblastic leukemia (n=58, median age=23 y, median survival time=18 y) with age-matched and sex-matched controls without history of cancer. Frailty phenotypes were determined using Fried frailty model. Association between frailty status and cardiometabolic conditions, systemic inflammation, and T-cell immunophenotype changes were also examined. Frailty and prefrailty were more common among survivors compared with controls (58.6% vs. 34.5%, P =0.019). Physical inactivity (39.7%) was the most frequently observed frailty criterion among the survivors. Prevalence of cardiometabolic conditions was comparable between the robust and frail/prefrail survivors. Robust survivors had a higher level of T-cell activation than the prefrail/frail survivors ( P <0.05), but no significant difference was observed for systemic inflammatory markers (IL-6 and C-reactive protein) and percentage of terminally differentiated T cells. Signs of frailty, especially physical inactivity, was detected in childhood acute lymphoblastic leukemia survivors early in their third decade of life. Survivors who were prefrail/frail also had altered T-cell activation; however, the role of such changes in T-cell phenotype in the etiology of frailty warrant further investigation.
Fulltext Impact strength and flexural properties enhancement of methacrylate silane treated oil palm mesocarp fiber reinforced biodegradable hybrid composites

Eng CC, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM

ScientificWorldJournal, 2014;2014:213180.
PMID: 25254230 DOI: 10.1155/2014/213180

Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.
Fulltext The influence of green surface modification of oil palm mesocarp fiber by superheated steam on the mechanical properties and dimensional stability of oil palm mesocarp fiber/poly(butylene succinate) biocomposite

Then YY, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM, Chieng BW

Int J Mol Sci, 2014;15(9):15344-57.
PMID: 25177865 DOI: 10.3390/ijms150915344

In this paper, superheated steam (SHS) was used as cost effective and green processing technique to modify oil palm mesocarp fiber (OPMF) for biocomposite applications. The purpose of this modification was to promote the adhesion between fiber and thermoplastic. The modification was carried out in a SHS oven at various temperature (200-230 °C) and time (30-120 min) under normal atmospheric pressure. The biocomposites from SHS-treated OPMFs and poly(butylene succinate) (PBS) at a weight ratio of 70:30 were prepared by melt blending technique. The mechanical properties and dimensional stability of the biocomposites were evaluated. This study showed that the SHS treatment increased the roughness of the fiber surface due to the removal of surface impurities and hemicellulose. The tensile, flexural and impact properties, as well as dimensional stability of the biocomposites were markedly enhanced by the presence of SHS-treated OPMF. Scanning electron microscopy analysis showed improvement of interfacial adhesion between PBS and SHS-treated OPMF. This work demonstrated that SHS could be used as an eco-friendly and sustainable processing method for modification of OPMF in biocomposite fabrication.
Fulltext Oil palm frond juice as future fermentation substrate: a feasibility study

Maail CM, Ariffin H, Hassan MA, Shah UK, Shirai Y

Biomed Res Int, 2014;2014:465270.
PMID: 25057489 DOI: 10.1155/2014/465270

Oil palm frond (OPF) juice is a potential industrial fermentation substrate as it has high sugars content and the OPF are readily available daily. However, maximum sugars yield and storage stability of the OPF juice are yet to be determined. This study was conducted to determine the effect of physical pretreatment and storage duration of OPF petiole on sugars yield. Storage stability of OPF juice at different storing conditions was also investigated. It was found that OPF petiole squeezed by hydraulic pressing machine gave the highest sugars recovery at almost 40 g/kg, accounting for a recovery yield of 88%. Storage of OPF petiole up to 72 hrs prior to squeezing reduced the free sugars by 11 g/kg. Concentrated OPF juice with 95% water removal had the best storage stability at both 4 and 30°C, when it was stored for 10 days. Moreover, concentrated OPF syrup prepared by thermal processing did not give any Maillard effect on microbial growth. Based on our results, OPF juice meets all the criteria as a good fermentation substrate as it is renewable, consistently available, and easy to be obtained, it does not inhibit microbial growth and product formation, and it contains no impurities.
Refractory acute monoblastic leukaemia with low hypodiploidy

Lum SH, Chin TF, Lau KH, Yap TY, Rajagopal R, Ariffin H

Int J Hematol, 2014 Mar;99(3):215-6.
PMID: 24470150 DOI: 10.1007/s12185-014-1515-0
Fulltext Improved properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by Comamonas sp. EB172 utilizing volatile fatty acids by regulating the nitrogen source

Zakaria MR, Ariffin H, Abd-Aziz S, Hassan MA, Shirai Y

Biomed Res Int, 2013;2013:237806.
PMID: 24106698 DOI: 10.1155/2013/237806

This study presents the effect of carbon to nitrogen ratio (C/N) (mol/mol) on the cell growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) accumulation by Comamonas sp. EB172 in 2 L fermenters using volatile fatty acids (VFA) as the carbon source. This VFA was supplemented with ammonium sulphate and yeast extract in the feeding solution to achieve C/N (mol/mol) 5, 15, 25, and 34.4, respectively. By extrapolating the C/N and the source of nitrogen, the properties of the polymers can be regulated. The number average molecular weight (M n ) of P(3HB-co-3HV) copolymer reached the highest at 838 × 10(3) Da with polydispersity index (PDI) value of 1.8, when the culture broth was supplemented with yeast extract (C/N 34.4). Tensile strength and Young's modulus of the copolymer containing 6-8 mol% 3HV were in the ranges of 13-14.4 MPa and 0.26-0.34 GPa, respectively, comparable to those of polyethylene (PE). Thus, Comamonas sp. EB172 has shown promising bacterial isolates producing polyhydroxyalkanoates from renewable carbon materials.
Renewable sugars from oil palm frond juice as an alternative novel fermentation feedstock for value-added products

Zahari MA, Zakaria MR, Ariffin H, Mokhtar MN, Salihon J, Shirai Y, et al.

Bioresour Technol, 2012 Apr;110:566-71.
PMID: 22342083 DOI: 10.1016/j.biortech.2012.01.119

In this paper, we report that pressed juice from oil palm frond (OPF) contained renewable sugars such as glucose, sucrose and fructose. By using a simple sugarcane press, 50% (wt/wt) of OPF juice was obtained from fresh OPF. The glucose content in the juice was 53.95±2.86g/l, which accounts for 70% of the total free sugars. We have examined the effect of various OPF juice concentrations on the production of poly(3-hydroxybutyrate), P(3HB) by Cupriavidus necator CCUG 52238(T). The cell dry mass in shake flask experiment reached 8.42g/l, with 32wt.% of P(3HB) at 30% (v/v) of OPF juice, comparable with using technical grade sugars. The biopolymer had a molecular mass, M(w) of 812kDa, with a low polydispersity index of 1.61. This result indicates that OPF juice can be used as an alternative renewable carbon source for P(3HB) production and has potential as a renewable carbon source.
Recovery and purification of intracellular polyhydroxyalkanoates from recombinant Cupriavidus necator using water and ethanol

Mohammadi M, Hassan MA, Phang LY, Ariffin H, Shirai Y, Ando Y

Biotechnol Lett, 2012 Feb;34(2):253-9.
PMID: 22038551 DOI: 10.1007/s10529-011-0783-5

A new halogen-free and environmental-friendly method using water and ethanol is developed as an alternative for the recovery of polyhydroxyalkanoates (PHA) from recombinant Cupriavidus necator in comparison to the established chloroform extraction method. After optimisation, our results showed that the halogen-free method produced a PHA with 81% purity and 96% recovery yield, in comparison to the chloroform extraction system which resulted in a highly pure PHA with 95% yield. Although the purity of the PHA using the new method is lower, the molecular weight of the extracted PHA is not compromised. This new method can be further developed as an alternative and more environmental-friendly method for industrial application.
Fulltext Clinical features of Malaysian children hospitalized with community-acquired seasonal influenza

Sam IC, Abdul-Murad A, Karunakaran R, Rampal S, Chan YF, Nathan AM, et al.

Int J Infect Dis, 2010 Sep;14 Suppl 3:e36-40.
PMID: 20153233 DOI: 10.1016/j.ijid.2009.10.005

OBJECTIVES: The clinical impact of seasonal influenza is understudied in tropical countries. The aim of this study was to describe the clinical features and seasonal pattern of influenza in children hospitalized in Malaysia, and to identify predictors of severe disease.
METHODS: Children hospitalized with community-acquired, laboratory-confirmed influenza at a teaching hospital in Kuala Lumpur, Malaysia during 2002-2007 were identified retrospectively. Clinical data were collected, and predictors of severe disease were identified by multivariate logistic regression. All influenza cases from 1982 to 2007 were also analyzed for seasonal patterns.
RESULTS: A total of 132 children were included in the study, 48 (36.4%) of whom had underlying medical conditions. The mean age was 2.5 years and 116 (87.9%) were <5 years old. The most common presenting features were fever or history of fever, cough, rhinitis, vomiting, and pharyngitis. Severe influenza was seen in 16 patients (12.1%; nine previously healthy), including 12 (9.1%; eight previously healthy) requiring intensive care. There were three (2.3%) deaths. Severe disease was associated with age <12 months, female sex, and absence of rhinitis on admission. Influenza was seen year-round, with peaks in November-January and May-July.
CONCLUSIONS: Seasonal influenza has a considerable impact on children hospitalized in Malaysia, in both the healthy and those with underlying medical conditions.

Study site: University Malaya Medical Centre (UMMC)
Microfluidic chip-based assay for post-hematopoietic stem cell transplantation chimerism monitoring using polymorphic tandem repeat markers

Daud SS, Ibrahim K, Choong SS, Vengidasan L, Chong LA, Ariffin H

Anal Biochem, 2010 Feb 15;397(2):181-5.
PMID: 19822126 DOI: 10.1016/j.ab.2009.10.008

Following hematopoietic stem cell transplantation (HSCT), it is important to determine whether engraftment is successful and to track the dynamic changes of the graft. Tandem repeats such as minisatellites and microsatellites are currently the most established markers for chimerism application. We have developed a reliable method to quantitatively evaluate engraftment status in post-allogeneic HSCT patients using variable number of tandem repeat (VNTR) markers and "lab-on-a-chip" microfluidic electrophoresis technology. Following identification of an informative marker by conventional polymerase chain reaction (PCR), donor chimerism percentage was calculated based on a standard curve generated from artificially mixed patient-donor DNA-specific alleles in serial dilutions. All PCR products were mixed with commercial gel dye and loaded into Agilent DNA 1000 microfluidic LabChips for DNA sizing and quantitation. In 44 patients, separation of pretransplant and donor DNA fragments was resolved clearly and accomplished rapidly within 30min. Chimerism analysis using this platform is able to detect an amount as low as 6.3% donor DNA with acceptable coefficient of variation values. We also demonstrated concordant chimerism analysis findings using both microchip tandem repeats and real-time PCR quantitation of insertion-deletion polymorphisms. This microchip platform obviates the need for fluorescently labeled primers or any post-PCR sample manipulation. Quantitative monitoring of post-HSCT chimerism status using microfluidic electrophoresis is a useful tool for both large- and small-scale post-HSCT chimerism centers.
Genetic susceptibility to childhood acute lymphoblastic leukemia shows protection in Malay boys: results from the Malaysia-Singapore ALL Study Group

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.
GATA1 mutations in patients with down syndrome and acute megakaryoblastic leukaemia do not always confer a good prognosis

Ariffin H, Garcia JC, Daud SS, Ibrahim K, Aizah N, Ong GB, et al.

Pediatr Blood Cancer, 2009 Jul;53(1):108-11.
PMID: 19260099 DOI: 10.1002/pbc.21983

Children with Down syndrome and acute megakaryoblastic leukemia (DS-AMKL) have been shown to have increased sensitivity to cytarabine based chemotherapy. The excellent prognosis in patients with DS-AMKL may be due to mutations in the GATA1 gene leading to reduced expression of the enzyme cytidine deaminase. This leads to a decreased ability to convert cytarabine into its inactive metabolite, resulting in high intracellular concentration of this cytotoxic agent. We report two cases of DS-AMKL with GATA1 mutations who had poor outcome. These patients had high expression levels of cytidine deaminase mRNA transcripts. We speculate that other factors can affect overall outcome in patients with DS-AMKL irrespective of the presence of GATA1 mutations.

Filters

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

External Links