Displaying publications 1 - 20 of 78 in total

  1. Tan J
    Nephrology (Carlton), 2014 May;19(5):288-95.
    PMID: 24641721 DOI: 10.1111/nep.12228
    Brunei Darussalam is a small South East Asian country with a high prevalence and incidence of end stage kidney disease (ESRD). This study aims to compare key performance indicators recorded in the Brunei Dialysis and Transplant Registry and department records against international practice. Registries from the USA (USRDS), UK (UK Renal Registry), Australasia (ANZDATA), Europe (ERA-EDTA Registry) and Malaysia (MDTR) were used for comparisons.
  2. Chung, B. H., Tan, J. R.
    The own price, income and price of a substitute are the determinants of demand in the classical theory of consumer behavior. We used the theory to analyze the demand for local rice in Malaysia by using time series variables. We examined whether there is a long run relationship among the variables by using the unit root and cointegration tests. We then conducted the Granger causality, variance decomposition and impulse response function tests to examine their directions of causality as well as short term dynamics. The results show that there is a long run relationship among the variables and a unidirectional causality from price and income to demand. There are also lagged and short term dynamics among the variables.
  3. Tan J
    Zootaxa, 2018 Aug 07;4457(1):129-142.
    PMID: 30314183 DOI: 10.11646/zootaxa.4457.1.6
    A new species of Argiope Audouin 1826, A. hoiseni new species is described from Perak and Selangor, Peninsular Malaysia based on morphology and DNA information of the mitochondrial (16S rRNA, COI and COII) and nuclear-encoded (H3A, 18S rRNA) molecular markers. Epigynal structure suggested Argiope hoiseni to be similar to A. jinghongensis Yin, Peng Wang 1994, A. luzona (Walckenaer 1841), A. pulchella Thorell 1881 and A. taprobanica Thorell 1887. Molecular sequence data including the new species inferred that it is monophyletic with an intraspecific variation of 0.87-3.59 % based on the 16S+COI+COII+H3A dataset. Phylogenetic analyses also revealed insights into the evolutionary lineages of Argiope species in Southeast Asia as well as corroborated recent taxonomic changes and species synonymies associated with Argiope. Two new distribution records were also reported for A. chloreis Thorell,1877 and A. doleschalli Thorell, 1873 in Peninsular Malaysia.
  4. Shaminie J, Peh SC, Tan J
    Pathology, 2005 Feb;37(1):39-44.
    PMID: 15875732
    AIM: Tumour suppressor gene p53 is a common target in carcinogenesis, reported to be altered and functionally inactive in 70% of human cancers. Although p53 mutations are less commonly present in haematological malignancies when compared with other solid tumours, they have been reported in histological transformation of follicular lymphoma. We aimed to investigate the frequency of p53 gene alterations in paraffin-embedded tissue using commercially available PCR-SSCP, and to correlate the results with P53 protein expression by immunohistochemistry.

    METHODS: Surgical samples from seven patients with a total of 17 sequential biopsies were retrieved for the study of p53 gene expression using immunohistochemical stain, and gene status by PCR-SSCP for exons 5-8. The tumours were graded according to the WHO classification criteria. P53 was distinctly over-expressed in five transformed higher grade biopsies, and all except one showed electrophoretic mobility shift in PCR-SSCP analysis. Sequencing analysis revealed single nucleotide substitutions in three of four of these high-grade transformed cases with band shift (75%), whereas some other studies reported a lower frequency of 25-30%, and mobility shift result was found to correlate with P53 expression. Lower grade tumours without P53 over-expression did not demonstrate band shift, and sequencing analysis did not reveal mutations.

    CONCLUSIONS: We demonstrated the feasibility of adopting PCR-SSCP for screening of p53 mutations in archival tissue samples in this study, and there is a strong correlation of p53 gene over-expression and mutation events in high-grade transformed tumours.

  5. Tan, J. A. M. A., George, E., Lim, E. J., Zakaria, Z., Hassan, R., Wee, Y. C., et al.
    Objectives: This study aimed to evaluate the UBI MAGIWELTM ζ-GLOBIN ELISA Kit for the presumptive diagnosis of αo-thalassaemia. The ELISA results obtained were confirmed by molecular characterisation of αo-thalassaemia using a Duplex-PCR. Methods: Routine peripheral blood counts and red cell indices were determined in 94 blood samples sent for Hb analysis. Hb subtypes were quantified by high performance liquid chromatography (HPLC) and Hb electrophoresis conducted on agarose gel at pH 8.5. Zeta-globin chain levels were determined using the UBI MAGIWELTM ζ-GLOBIN ELISA Kit. Molecular analysis was performed using a duplex-PCR which simultaneously amplifies
    a normal 136 bp sequence between the ψα−α2-globin genes and a 730 bp Southeast Asian deletion-specific sequence (–SEA) between the ψα2−θ1-globin genes. Results: Using the ELISA assay kit, 20 blood samples were presumptively identified as α-thalassaemia carriers from elevated ζ-globin chains (OD>0.3) while the remaining 74 blood samples showed OD
  6. Kuppusamy UR, Tan JA
    West Indian Med J, 2011 Jan;60(1):3-8.
    PMID: 21809703
    Beta-thalassaemia major causes severe anaemia and patients with it may be transfusion-dependent for life. Regular blood transfusions cause iron-overload that leads to oxidative damage which can hasten mortality. The objective of this research was to study the oxidant-antioxidant indices in beta-thalassaemia major patients at the University of Malaya Medical Centre (UMMC) who were on desferrioxamine-chelation or without chelation therapy. Blood was collected from 39 Chinese patients and 20 controls. Plasma and peripheral blood mononuclear cell lysates (PBMC) were extracted and biochemical tests to evaluate oxidative stress were performed. Oxidative stress was evident in these patients as advanced oxidized protein products (AOPP) and lipid hydroperoxides were elevated, whereas glutathione peroxidase activity and the ferric reducing antioxidant power (FRAP) were reduced. The catalase activity in the patients' PBMC was elevated, possibly as a compensatory mechanism for the reduced glutathione peroxidase activity in both red blood cells and PBMC. The lower FRAP and higher AOPP levels in the non-chelated patients compared with the chelated patients were indicative of a lower oxidative stress level in the chelated patients. The ferritin levels in the chelated and non-chelated patients were high and the mean levels of liver enzyme activities in the majority of patients were elevated regardless of chelation therapy. In conclusion, this study indicates that desferrioxamine chelation therapy does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in Malaysian Chinese beta-thalassaemia major patients.
  7. Tan JK, Tan EL, Gan SY
    Exp. Oncol., 2014 Sep;36(3):170-3.
    PMID: 25265349
    Deregulation of microRNA has been associated with cancer progression and the modification of cancer phenotypes could be achieved by targeting microRNA expression. This study aimed to determine the effects of miR-372 on cell progression and gene expression in nasopharyngeal carcinoma cell line, TW01.
  8. Tan JS, Ong Kc KC, Rhodes A
    Malays J Pathol, 2016 Aug;38(2):75-82.
    PMID: 27568663 MyJurnal
    Heat shock proteins (HSPs) are a family of evolutionary conserved proteins that work as molecular chaperones for cellular proteins essential for cell viability and growth as well as having numerous cyto-protective roles. They are sub-categorised based on their molecular weights; amongst which some of the most extensively studied are the HSP90 and HSP70 families. Important members of these two families; Heat shock proteins 70 and heat shock proteins 90 (Hsp70/90), are the glucose regulated proteins (GRP). These stress-inducible chaperones possess distinct roles from that of the other HSPs, residing mostly in the endoplasmic reticulum and mitochondria, but they can also be translocated to other cellular locations. Their ability in adapting to stress conditions in the tumour microenvironment suggests novel functions in cancer. GRPs have been implicated in many crucial steps of carcinogenesis to include stabilization of oncogenic proteins, induction of tumour angiogenesis, inhibition of apoptosis and replicative senescence, and promotion of invasion and metastasis.
  9. Chen WS, Tan JH, Mohamad Y, Imran R
    Injury, 2019 May;50(5):1118-1124.
    PMID: 30591225 DOI: 10.1016/j.injury.2018.12.031
    BACKGROUND: The establishment of an accurate prognostic model in major trauma patients is important mainly because this group of patients will benefit the most. Clinical prediction models must be validated internally and externally on a regular basis to ensure the prediction is accurate and current. This study aims to externally validate two prediction models, the Trauma and Injury Severity Score model developed using the Major Trauma Outcome Study in North America (MTOS-TRISS model), and the NTrD-TRISS model, which is a refined MTOS-TRISS model with coefficients derived from the Malaysian National Trauma Database (NTrD), by regarding mortality as the outcome measurement.

    METHOD: This retrospective study included patients with major trauma injuries reported to a trauma centre of Hospital Sultanah Aminah over a 6-year period from 2011 and 2017. Model validation was examined using the measures of discrimination and calibration. Discrimination was assessed using the area under the receiver operating characteristic curve (AUC) and 95% confidence interval (CI). The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to examine calibration capabilities. The predictive validity of both MTOS-TRISS and NTrD-TRISS models were further evaluated by incorporating parameters such as the New Injury Severity Scale and the Injury Severity Score.

    RESULTS: Total patients of 3788 (3434 blunt and 354 penetrating injuries) with average age of 37 years (standard deviation of 16 years) were included in this study. All MTOS-TRISS and NTrD-TRISS models examined in this study showed adequate discriminative ability with AUCs ranged from 0.86 to 0.89 for patients with blunt trauma mechanism and 0.89 to 0.99 for patients with penetrating trauma mechanism. The H-L goodness-of-fit test indicated the NTrD-TRISS model calibrated as good as the MTOS-TRISS model for patients with blunt trauma mechanism.

    CONCLUSION: For patients with blunt trauma mechanism, both the MTOS-TRISS and NTrD-TRISS models showed good discrimination and calibration performances. Discrimination performance for the NTrD-TRISS model was revealed to be as good as the MTOS-TRISS model specifically for patients with penetrating trauma mechanism. Overall, this validation study has ascertained the discrimination and calibration performances of the NTrD-TRISS model to be as good as the MTOS-TRISS model particularly for patients with blunt trauma mechanism.

  10. Tan JH, Lip H, Ong W, Omar S
    Malays Fam Physician, 2019;14(2):29-31.
    PMID: 31827733
    An Intrauterine contraceptive devices (IUCD) is commonly inserted by the primary health care physician. It can migrate into pelvic or abdominal organs. When a pregnancy occurs following an insertion of an IUCD, there should be a high suspicion of uterine perforation or possible migration. A radiograph can be done in the primary health care clinic to search for a missing IUCD. Early referral to the urology service is warranted when a patient presents with recurrent urinary tract infections. Removal of an intravesical IUCD can be managed with cystoscopy, laparoscopy or open surgery. Herein, we report a case of IUCD migration into the bladder. This case will highlight the importance of proper technique, careful insertion and the role of ultrasound.
  11. Ng ZQ, Tan JH, Tan H
    Malays Fam Physician, 2019;14(2):32-35.
    PMID: 31827734
    Caecal volvulus has been reported to be associated with various abdominal and pelvic pathologies. Its signs and symptoms are usually non-specific and maybe overlooked in favour of benign causes, such as constipation. A high degree of suspicion is required for prompt diagnosis. Herein, we report on an unusual case of caecal volvulus after a dental procedure that was managed initially as constipation.
  12. Achin NA, Kit TJ, Ngah WZW, Makpol S, Mazlan M, Hamezah HS, et al.
    Curr Aging Sci, 2018;11(3):182-194.
    PMID: 30338748 DOI: 10.2174/1874609811666181019141217
    BACKGROUND: Cognitive frailty emerges as one of the threats to healthy aging. It is in continuum with advancing of age with uncertain indicator between pathological and physiological changes. Alterations in pathways associated with the aging process have been observed including oxidative stress, lipid metabolism, and inflammation. However, the exact mechanisms leading to cognitive decline are still unclear.

    OBJECTIVE: This study was sought to assess the level of cognitive functions and linked with blood oxidative status during normal aging in rats.

    METHODS: A longitudinal study using male Sprague Dawley rats was performed starting from the age of 14 months old to 27 months old. Cognitive functions tests such as open field, Morris water maze and object recognition were determined at the age of 14, 18, 23, and 27 months old and were compared with group 3 months old. Blood was collected from the orbital venous sinus and oxidative status was determined by measuring the level of DNA damage, lipid peroxidation, protein oxidation and antioxidant enzymes activity.

    RESULTS: Aged rats showed declining exploratory behavior and increased in the level of anxiety as compared to the young rats. The level of DNA damage increased with increasing age. Interestingly, our study found that both levels of malondialdehyde and plasma carbonyl content decreased with age. In addition, the level of superoxide dismutase activity was significantly decreased with age whereas catalase activity was significantly increased from 18 months of age. However, no significant difference was found in glutathione peroxidase activity among all age groups.

    CONCLUSION: The progressions of cognitive impairment in normal aging rats are linked to the increment in the level of DNA damage.

  13. George E, Teh LK, Tan J, Lai MI, Wong L
    Pathology, 2013 01;45(1):62-5.
    PMID: 23222244 DOI: 10.1097/PAT.0b013e32835af7c1
    AIMS: Classical carriers of β-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino β-deletion has high raised HbA2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser is a common instrument used to quantify HbA2 levels in thalassaemia screening. This study aimed to determine HbA2 levels in carriers of Filipino β-mutation using the BioRad Variant II Hb analyser.

    METHODS: The Filipino β-deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β-thalassaemia patients who were homozygous for the Filipino β-deletion in the indigenous population of Sabah, Malaysia. Hb subtypes were quantified on the BioRad Variant II Hb analyser. Concurrent α-thalassaemia was identified by multiplex gap-PCR for deletions and amplification refractory mutation system (ARMS)-PCR for non-deletional mutations.

    RESULTS: The mean HbA2 level for Filipino β-thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α heterozygous) and 6.7 ± 0.36 (-α homozygous). The HbA2 levels were all >4% in keeping with the findings of classical β-thalassaemia trait and significantly higher than levels seen in non-deletional forms of β-thalassaemia.

    CONCLUSION: The HbA2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β-thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α) is associated with significantly higher HbA2 level.

  14. Peh SC, Shaminie J, Tai YC, Tan J, Gan SS
    Histopathology, 2004 Nov;45(5):501-10.
    PMID: 15500654
    Follicular lymphoma is frequently associated with t(14;18)(q32;q21) translocation. This study was undertaken to determine the pattern of Bcl-2, CD10 and Bcl-6 expression in relation to t(14;18) translocation in follicular lymphoma from a cohort of a multi-ethnic Asian population.
  15. Balraj P, Khoo AS, Volpi L, Tan JA, Nair S, Abdullah H
    Singapore Med J, 2002 Apr;43(4):194-7.
    PMID: 12188064
    Thirty patients with early onset breast cancer or familial breast cancer from Malaysia were analysed for germline mutation in the early onset breast cancer I gene (BRCA1). Direct sequencing of the entire coding region of BRCA1 identified a frameshift mutation, c.5447-5448insC (insC5447) (codon 1776 of exon 21) in a patient aged 32 of the Malay ethnic origin, who had no family history of breast and/or ovarian cancer. Eight polymorphisms (2201C > T, 2430T > C, P871L, E1038G, K1183R, 4427T > C, S1613G and IVS8-57delT) were identified in the samples tested.
  16. Tan JA, Tay JS, Aziz NB, Saha N
    Hum. Hered., 1996 Jul-Aug;46(4):236-8.
    PMID: 8807327
    Restriction fragment length polymorphism (RFLP) of the gene encoding the beta chain of the human T cell receptor (TcR) was studied in three ethnic groups in Singapore by Southern blotting. Polymorphism in the beta chain gene was identified in BglII-digested DNA samples using a 770-bp TcR beta cDNA clone containing the joining and constant region segments. The TcR beta/BglII polymorphism was studied in 136 Chinese, 93 Indian and 88 Malay samples. The frequency of the less frequent allele (TcR beta*2) in all the ethnic groups was significantly lower (0.15-0.29, p < 0.01) than that in the Caucasians (0.46). Indians had a significantly lower frequency of this allele (0.15) than the Chinese (0.29) and Malays (0.26).
  17. Tan JA, Tay SH, Kham KY, Wong HB
    Jpn. J. Hum. Genet., 1993 Sep;38(3):315-8.
    PMID: 7903173 DOI: 10.1007/BF01874141
    The distribution of restriction fragment length polymorphism (RFLP) at the BamH1 site of the beta-globin gene was investigated in the Chinese, Indian, and Malay race in Singapore. The sample comprised of 183 normal individuals and 35 beta-thalassemia carriers in which 13 were couples with at least one beta-major child. The results from this study indicate that BamH1 polymorphism will be informative in 22% of pregnancies at risk for beta-thalassemia major in Chinese, 19% in Malays and 7% in Indians. In prenatal diagnosis using BamH1 polymorphism for one beta-major affected family, the fetus was diagnosed to be normal or beta-carrier. The validity of BamH1 polymorphism in the exclusion of beta-thalassemia major was subsequently confirmed at birth by globin chain biosynthesis.
Contact Us

Please provide feedback to Administrator (tengcl@gmail.com)

External Links