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Fulltext Positive direct antiglobulin test with Unasyn--a case report

Leong CF, Cheong SK, Fadilah SA

Med J Malaysia, 1999 Dec;54(4):517-9.
PMID: 11072473

A 56-year-old Chinese lady with valvular heart disease and atrial fibrillation was referred to us from a private hospital for further management of autoimmune haemolytic anaemia. Physical examination and laboratory investigations did not support the diagnosis of haemolytic anaemia. However, direct antiglobulin test (DAT) was strongly positive with anti-IgG and negative with anti-C3d. There was also mild anaemia and reticulocytosis, which was attributable to persistent haematuria. The DAT became positive after commencing Unasyn and cessation was associated with decreasing reactivity of the positive DAT. We believe that the positive DAT in this patient was most likely due to the Unasyn therapy.
Immunostaining of formalin-fixed, paraffin-embedded tissues for malignant lymphomas

Lim YC, Phang KS, Cheong SK

Malays J Pathol, 1992 Dec;14(2):85-9.
PMID: 1304629

With the advent of new monoclonal antibodies that are applicable to formalin-fixed, paraffin embedded sections, immunophenotyping is becoming increasingly important in the diagnosis and classification of lymphomas. However, multiple factors such as fixation, trypsinization and even type of antibodies used have certain effects on the final outcome of the staining procedure. In this paper we report our experience and the problems encountered in our laboratory when we first tried to establish a workable immunostaining protocol for formalin-fixed, paraffin embedded tissue sections using the immunoalkaline phosphatase technique.
Surfactant protein A and stable microbubble formation in tracheal aspirates

Cheong KB, Cheong SK, Boo NY

Malays J Pathol, 1996 Dec;18(2):101-5.
PMID: 10879230

This study aimed to determine the role of surfactant protein A (SP-A) in the formation of stable microbubble in tracheal aspirates. Our results showed that as the concentration of anti SP-A antibodies added to tracheal aspirate specimens increased, the number of stable microbubble formed in the specimen decreased. The correlation between stable microbubble counts and the SP-A levels in the tracheal aspirates was good, r = 0.85, p < 0.05. This study suggests that SP-A plays an important role in stable microbubble formation. Measurement of small stable microbubbles is thus a useful bedside test for predicting the SP-A activity in the tracheal aspirates and in indirect measurement of lung maturity.
In vivo evidence of all-trans retinoic acid inducing maturation in acute promyelocytic leukaemia

Hamidah HN, Cheong SK, Ainoon O

Acta Haematol., 1993;89(1):50-1.
PMID: 8480488

All-trans retinoic acid therapy induces maturation in acute promyelocytic leukaemia. We document in vivo evidence of differentiation by all-trans retinoic acid in a case of acute promyelocytic leukaemia which was characterized by cytoplasmic vacuolations.
The cellular immune status of HBsAg-positive carriers in Malaysia

Choong ML, Ton SH, Cheong SK

Asian Pac J Allergy Immunol, 1996 Jun;14(1):19-24.
PMID: 8980796

The percentage of lymphocyte subsets from the peripheral blood of healthy adults and hepatitis B surface antigen (HBsAg) carriers were analyzed by flow cytometry. The five lymphocyte subsets studied were:- T (CD3) cells, B (CD19) cells, CD4 cells, CD8 cells, Natural Killer (CD3- CD16+/CD56+) cells (NK cells) and the CD4/CD8 ratio. The percentage (mean +/- SD) for the five lymphocyte subsets from the healthy adults were (67.5 +/- 8.5)%, (12.4 +/- 4.5)%, (35.5 +/- 7.8)%, (36.8 +/- 8.5)%, (17.9 +/- 8.1)% and 1.1 +/- 0.6, respectively. HBsAg carriers positive for HBV-DNA had a lower CD4/CD8 ratio than the healthy population (P = 0.030). The percentage of CD8 cells in HBsAg carriers increased significantly (r = 0.28; P = 0.019) with an increase in ALT levels but the values remained within normal range. The percentage of NK cells and CD4/CD8 ratio in HBsAg carriers positive for anti-HBe were higher than HBsAg carriers negative for anti-HBe (92% of which are HBeAg positive) (P = 0.045 and P = 0.035, respectively). The CD4/CD8 ratio in HBsAg carriers negative for anti-HBe (92% positive for HBeAg) was also lower than in the healthy population (P = 0.042). HBsAg carriers positive for HBV-DNA, HBeAg and raised ALT levels had a lower CD4/ CD8 ratio than did the healthy population. The lower ratio was due to an increase in the percentage of CD8 cells. This suggests an activated immune response triggered by the infection in an attempt to clear the virus. HBsAg carriers with normal ALT levels and who are negative for HBV-DNA may be in a state of tolerance.
Influence of race, age and sex on the lymphocyte subsets in peripheral blood of healthy Malaysian adults

Choong ML, Ton SH, Cheong SK

Ann. Clin. Biochem., 1995 Nov;32 ( Pt 6):532-9.
PMID: 8579284

The lymphocyte subsets in the peripheral blood of healthy Malaysian adults (212 subjects, age 18-71 years) were analysed using a flow cytometer FACScan in an effort to establish a reference range for the lymphocyte subsets. The lymphocyte subsets studied were T cells (CD3), B cells (CD19), natural killer (NK) cells (CD3- CD16+/CD56+), helper/inducer cells (CD4), cytotoxic/suppressor cells (CD8) and the helper/suppressor ratio (CD4/CD8). The distributions of T cells, CD4 cells and CD8 cells were symmetric about their means while B cells, NK cells and CD4/CD8 ratio followed a skewed distribution. Differences in race were observed for T cells, NK cells, CD4 cells and CD4/CD8 ratio where the Indians were significantly different from the Malays and the Chinese (higher T cells, CD4 cells and CD4/CD8 ratio and lower NK cells). The B cells were significantly lower in the Chinese than the Malays and the Indians. Age differences were seen only in the Chinese where increased CD4 cells and CD4/CD8 ratio, and decreased CD8 cells were observed. A sex difference was observed only in the Chinese where the CD4/CD8 ratio was significantly higher in females than males.
Fulltext A case of kala-azar diagnosed by bone marrow aspiration

Hamidah NH, Cheong SK, Abu Hassan J

Malays J Pathol, 1995 Jun;17(1):39-41.
PMID: 8907004

A 35-year-old man from Bangladesh, who had been in Malaysia for approximately a year, was extensively investigated for more than two months in a state hospital for pyrexia with hepatosplenomegaly. However, no obvious cause of his illness was found. He was treated with multiple antibiotics with no resolution of pyrexia and hepatosplenomegaly. He was later referred to the Haematology Unit, Universiti Kebangsaan Malaysia for further assessment as a case of lymphoma. On carefully reviewing his bone marrow aspirate smears, the diagnosis of leishmaniasis (kala-azar) was finally made. The patient responded to treatment with pentamidine.
Fulltext First trimester prenatal diagnosis of beta-thalassaemia following chorionic villus sampling

Chandran R, Ainoon O, Anson I, Anne J, Cheong SK

Med J Malaysia, 1993 Sep;48(3):341-4.
PMID: 8183149

DNA analysis for the diagnosis of beta-thalassaemia is a relatively new technique in Malaysia. This, combined with chorionic villus sampling, has enabled us to offer prenatal diagnosis in the first trimester for this common condition. To the best of our knowledge, this has not hitherto been reported in Malaysia.
Single incubation double esterase cytochemical reaction using a single coupling reagent

Ainoon O, Jabamoney AJ, Cheong SK

Malays J Pathol, 1991 Jun;13(1):47-9.
PMID: 1724544

Most methods used in double esterase cytochemistry for the diagnosis and classification of acute myeloid leukaemias require double incubation and staining, using separate coupling reagents. We evaluated a method by Swirsky on our normal and abnormal blood and bone marrow smears where only a single incubation and the use of a single coupling reagent is required. Its short incubation period and its strong positive reaction for butyrate esterase in demonstrating cells of monocytic lineage gives it an advantage over the conventional double incubation technique.
Fulltext A freeze-dried method for preparation of G6PD reagent tubes

Cheong SK, Lim YC, Mok KL

Malays J Pathol, 1991 Jun;13(1):51-2.
PMID: 1795563

Mixed reagents for the Glucose-6-phosphate dehydrogenase (G6PD) deficiency fluorescent screening test were freeze-dried in plastic tubes. The reagents were then reconstituted with distilled water and the test was performed in the usual way. Initial testing with the freeze-dried mixed reagents gave consistent positive reaction to 12 normal blood samples and negative reaction to 9 G6PD deficient blood samples. This will enable a laboratory with freeze-drying facilities to prepare reagent tubes in bulk. As these tubes can be kept at 4 degrees C and do not require to be stored at -20 degrees C, a major laboratory can prepare these tubes and supply small laboratories for screening purposes.
Fulltext Hairy cell leukemia. A case report

Ainoon O, Megat R, Cheong SK, Halimah Y

Med J Malaysia, 1988 Mar;43(1):62-4.
PMID: 3244323
A comparative study of two methods for the isolation of human leucocytes for DNA extraction

Lim LH, Ton SH, Cheong SK

Malays J Pathol, 1990 Jun;12(1):39-41.
PMID: 2090888

The 'Dextran' and the 'Buffy-coat' methods for isolation of human leucocytes for DNA extraction were compared on the basis of DNA yield from the same amounts (10 ml) of blood. Human leucocytes from a total of 11 samples were isolated using both methods for each sample after which DNA was extracted. Extracted DNA samples were treated with ribonucleases and proteinase K after which the yields were quantitated by measuring absorbance at 260 nm. The 'Buffy-coat' method yielded a mean concentration of DNA of 476.7 micrograms/ml (range: 212 to 700 micrograms/ml) while the 'Dextran' method yielded 188.4 micrograms/ml (range: 64 to 340 micrograms/ml). The difference was confirmed by subjecting the extracted DNA samples to agarose gel electrophoresis.
Reprogramming human dermal fibroblast into induced pluripotent stem cells using nonintegrative Sendai virus for transduction

Tai L, Teoh HK, Cheong SK

Malays J Pathol, 2018 Dec;40(3):325-329.
PMID: 30580364

INTRODUCTION: Induced pluripotent stem cells (iPSC) that exhibit embryonic stem cell-like properties with unlimited self-renewal and multilineage differentiation properties, are a potential cell source in regenerative medicine and cell-based therapy. Although retroviral and lentiviral transduction methods to generate iPSC are well established, the risk of mutagenesis limits the use of these products for therapeutic applications.
MATERIALS AND METHODS: In this study, reprogramming of human dermal fibroblasts (NHDF) into iPSC was carried out using non-integrative Sendai virus for transduction. The iPSC clones were characterised based on the morphological changes, gene expression of pluripotency markers, and spontaneous and directed differentiation abilities into cells of different germ layers.
RESULTS: On day 18-25 post-transduction, colonies with embryonic stem cell-like morphology were obtained. The iPSC generated were free of Sendai genome and transgene after passage 10, as confirmed by RT-PCR. NHDF-derived iPSC expressed multiple pluripotency markers in qRT-PCR and immunofluorescence staining. When cultured in suspension for 8 days, iPSC successfully formed embryoid body-like spheres. NHDF-derived iPSC also demonstrated the ability to undergo directed differentiation into ectoderm and endoderm.
CONCLUSION: NHDF were successfully reprogrammed into iPSC using non-integrating Sendai virus for transduction.
Circulating tissue factor, tissue factor pathway inhibitor and D-dimer in umbilical cord blood of normal term neonates and adult plasma

Tay SP, Cheong SK, Boo NY

Blood Coagul Fibrinolysis, 2003 Feb;14(2):125-9.
PMID: 12632021

The investigation of many hemostatic defects in newborns is restricted by the lack of normal reference values. The coagulation system of the neonate differs in many ways from that of the adult. The present study was designed to compare the concentrations of tissue factor (TF), tissue factor pathway inhibitor (TFPI) and D-dimer (DD) in the umbilical cord blood of healthy newborns and in adult plasma. TF antigen was quantified using an in-house enzyme-linked immunosorbent assay, whereas TFPI and DD levels were measured with commercial kits. The mean TF level in cord blood (mean standard deviation, 183.94 103.63 pg/ml) was significantly higher ( = 0.008) than that in adults (136.64 65.09 pg/ml). Cord blood exhibited enhanced fibrinolysis, as was reflected by a significantly higher level of DD (924.57 733.87 ng/ml, 0.001) than that in adults (45.57 17.21 ng/ml). Conversely, cord blood (30.88 10.16 ng/ml) demonstrated significantly lower ( 0.001) TFPI levels than that in adults (55.77 21.16 ng/ml). However, no significant differences of these three hemostatic markers were noted between both gender groups in newborns and adults. Our findings indicate that an active and dynamic state of hemostasis exists in cord blood, as the fluidity of cord blood remains preserved in the presence of birth injury.
In vitro differentiation of mesenchymal stem cells into mesangial cells when co-cultured with injured mesangial cells

Wong CY, Tan EL, Cheong SK

Cell Biol Int, 2014 Apr;38(4):497-501.
PMID: 24375917 DOI: 10.1002/cbin.10231

Mesangial cells are one of the three major cell types of the kidney glomerulus that provide physical support for the glomerular capillary lumen of the kidney. Loss of mesangial cells due to pathologic conditions, such as glomerulonephritis and diabetic nephropathy, can impair renal function. Mesenchymal stem cells (MSC) are attractive candidates for kidney repair therapy since they can enhance recovery and protect against kidney failure. MSC can differentiate into mesangial cells in vivo. We have investigated the ability of MSC to differentiate into mesangial cells in vitro; they were co-cultured with oxidant-injured mesangial cells before being analysed by flow cytometry and for contractility. MSC co-cultured with injured mesangial cells had a mesangial cell-like morphology and contracted in response to angiotensin II. They expressed CD54(-) CD62E(+) in direct contrast to the CD54(+) CD62E(-) of pure MSC. In conclusion, MSC can differentiate into mesangial cells in vitro when co-cultured with injured mesangial cells.
Fulltext Student learning disability experiences, training and services needs of secondary school teachers

Teoh HJ, Cheong SK, Woo PJ

Malaysian Journal of Psychiatry, 2008;17(2):1-14.
MyJurnal

107 secondary school teachers were surveyed to find out about their observations of children with learning disorders at schools. The respondents reported that the most commonly observed disorders involved difficulty paying attention, difficulty learning a second language, being fidgety and having difficulty sitting still, and having poor comprehension. They also indicated that whilst some children made fun of their classmates with learning disorder, others tried to assist their classmates. The most common reaction of parents was to send the child for lots of tuition, and to be very frustrated with the child. In addition, some parents neglected their children’s learning disorder, and many did not seem to realise how serious the problem was. When it came to the needs of teachers, the most common need that the teachers reported was to have the parents cooperate with them and to have support from the education authorities. The paper discusses the implications of these findings and proposes suggestions for dealing with the training needs of teachers working in the area of learning disorders.
Study of EEG alpha wave response on the effects of video-guided deep breathing on pain rehabilitation

Ramalingam V, Cheong SK, Lee PF

Technol Health Care, 2023;31(1):37-46.
PMID: 35723127 DOI: 10.3233/THC-213531

BACKGROUND: Athletes with chronic ankle pain (CAP) are more inclined to suffer from physical and psychological pain depending on the severity of the injuries, which might trigger the powerless feeling on future sports participation. Therefore, an efficient and simple method is useful to integrate into conventional physiotherapy (CP) for maintaining mental wellness.
OBJECTIVE: This research aimed to verify the effects and progress of video-guided deep breathing (DB) integrated into CP through study on the changes of alpha waves and pain scale.
METHODS: Alpha waves were recorded using an electroencephalogram (EEG) and a visual analogue scale (VAS) to assess pain intensity before and after the intervention (6 weeks). Thirty CAP participants were recruited and randomly assigned to two groups: group A for video-guided DB integration into their CP and group B for CP. The effects of pre and post intervention were analyzed using a paired t-test with statistical significance set at p< 0.05.
RESULTS: Profound results from the research have shown that the participants who received both the DB+CP revealed a significant increase in alpha wave (p< 0.05) at occipital region.
CONCLUSION: The significant result reveals an increase in alpha waves in the occipital region after 6 weeks and indicates that the video-guided DB with a smartphone application is able to produce a change in CAP participants. This supports the DB integration to the CP for altering the pain perception.
Effect of six-week short-duration deep breathing on young adults with chronic ankle instability-a pilot randomized control trial

Ramalingam V, Cheong SK, Lee PF

BMC Sports Sci Med Rehabil, 2023 Nov 15;15(1):155.
PMID: 37968738 DOI: 10.1186/s13102-023-00758-5

BACKGROUND: Chronic ankle instability (CAI) is the most common injury in youth sports, which leads to psychological stress from doubting their performance. Cost effective and easy to access tool to reduce the stress among this target group are desired. Therefore, the purpose of this study was to investigate the effect of adding on intervention with short-duration deep breathing (SDDB) alongside with conventional physiotherapy (CP) among young adults with chronic ankle instability (CAI).
METHODS: Total of 30 CAI participants attended physiotherapy, who were randomly assigned into control and experimental groups. The participants in the experimental group received combined intervention (SDDB + CP), and the control group received CP for 6 weeks. The effectiveness of interventions was assessed at 3 intervals with a battery of questionnaires (Visual Analog Score, Cumberland Ankle Instability Tool, Mindful Attention Awareness Scale, and Oxford Happiness Questionnaire) at the end of week 3, week 6, and week 12 as follow-up. A two-way repeated measures of ANOVA was applied to report the statistical significance at p
Rapid metastasis of breast cancer cells from primary tumour to liver

Kumar SS, Radhakrishnan AK, Cheong SK

Pak J Biol Sci, 2010 Apr 01;13(7):303-15.
PMID: 20836285

The aim of this study was to establish an animal model of mammary carcinoma metastasis to discern the in vivo effects of growth and spread of breast cancer. Six-week-old female BALB/c mice were inoculated with 4T1 murine breast cancer cells. Mice weight and primary tumour mass volume were regularly recorded to study the physical effects of a vigorously growing and spreading of cancer cell line. Gross and histological studies were carried out to determine the approximate day of metastatic onset. Production of IFN-gamma was assessed by ELISA to understand its role in tumour growth and metastasis. Lymphocyte markers such as CD8+, CD25 and CD49b were analysed to elucidate its role in tumour growth and progression. Present study showed that the metastatic onset occurs approximately 11 days after the mice were inoculated with the 4T1 murine breast cancer cells. Gross studies showed hepatosplenomegaly. The breast cancer cells from primary tumour were found to spread rapidly to the liver on day 11. IFN-gamma production was higher in inoculated mice serum compared to control mice serum. Higher numbers of CD8+, CD25 and CD49b cells were observed in the peripheral blood of inoculated mice, compared to control mice. In conclusion, the 4T1 murine breast cancer cells can migrate and metastasise rapidly to the liver, eliciting various immune responses.
Fulltext Comparing the ability of freshly generated and cryopreserved dendritic cell vaccines to inhibit growth of breast cancer in a mouse model

Radhakrishnan AK, Sim GC, Cheong SK

Biores Open Access, 2012 Oct;1(5):239-46.
PMID: 23515111 DOI: 10.1089/biores.2012.0229

Repetitive vaccinations with dendritic cell (DC)-based vaccines over long periods of time can break pre-existing tolerance to tumors and achieve clinically relevant immune response. This requires a large number of DCs to be generated under good manufacturing protocol, which is time- and cost intensive. Thus, producing a large numbers of DCs at one time point and cryopreserving these cells in ready-for-use aliquots for clinical application may overcome this constraint. This could also reduce batch-to-batch variations. In this study, we generated DCs from bone marrow obtained from BALB/c mice. Some of the generated DCs were cryopreserved before conducting various tests. There were no significant differences in the morphology and phenotype between cryopreserved and freshly generated DCs. Both types of DCs pulsed with tumor lysate (TL) from 4T1 murine mammary cancer cells (DC+TL) possessed a similar capacity to stimulate the proliferation of T-cells. In addition, cryopreserved and fresh DC pulsed with TL showed similar tumor growth inhibition patterns. Both DCs induced initial retardation of tumor growth (p<0.05) and prolonged the survival (p<0.05) of tumor-bearing mice treated with DC+TL as compared with nontreated control mice. Cryopreserved DCs shared similar therapeutic efficacy to fresh DCs, and this finding lends supports the routine use of cryopreserved DCs in future clinical trials.

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