MyMedR

Fulltext A 2-year study of neonatal mortality in a large Malaysian hospital

Boo NY, Nasri NM, Cheong SK, Sivamohan N

Singapore Med J, 1991 Apr;32(2):142-7.

PMID: 2042076

A 2-year study was carried out in the Maternity Hospital, Kuala Lumpur to determine the neonatal mortality rates. This Hospital functions both as the local service centre as well as the national referral centre in Malaysia. Its neonatal services, however, were equipped and manned at those below Level III perinatal centre. During the study period 52, 877 livebirths took place in the Hospital. In 1987 and 1988 respectively, the low birthweight (less than 2500 gm) rates were: 112.8 and 101.9 per 1000 livebirths, very low birthweight (less than 1500 gm) rates: 11.1 and 8.8 per 1000 livebirths, neonatal mortality rates: 12.5 and 10.7 per 1000 livebirths and neonatal mortality risk ratio: 1.15 and 1.27. There was significant difference in mortality rates among the Malay, Chinese and Indian babies born in this hospital: the Indians had the highest and the Chinese the lowest rates. Babies delivered by breech or lower segment Caesarean section (LSCS) also had significantly higher mortality than those delivered by other modes of delivery. Low birthweight neonates constituted less than 45% of the total special care nursery admission but contributed to more than 70% of the total neonatal deaths. The common causes of neonatal deaths were problems of prematurity, infection, asphyxia and congenital malformations. Preterm and low birthweight neonates died primarily from problems of prematurity or infection. Term and larger neonates died mainly from asphyxia. More than 75% of the neonatal deaths occurred before 7 days of life. Improvement of antenatal care in the community and upgrading of perinatal services in this Hospital could help to lower the morbidity and mortality due to preventable causes.

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.

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.

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 Abnormalities of chromosome 11Q in three cases of acute myeloid leukemia

Ten SK, Khor MK, Khalid H, Lin HP, Ng SC, Cheong SK, et al.

Singapore Med J, 1992 Apr;33(2):164-6.

PMID: 1621121

The haematological findings and case history of 3 patients with the association of acute myeloid leukemia and translocation involving the long arm of chromosome no. 11 are presented. The recipient chromosome for the translocated material from chromosome 11 differs in all the three cases being namely chromosomes 1, 10 and 17.

Acute leukaemia masquerading as acute abdomen

S Abdul Wahid F, Cheong SK, Azman Ali R

Hosp Med, 2002 Jun;63(6):372-3.

PMID: 12096671 DOI: 10.12968/hosp.2002.63.6.2011

Acute leukemia and lymphoma in pregnancy, a retrospective study from a tertiary center in Malaysia

Fann RJ, D'Silv EC, Tanusha K, Wong TK, Lee BS, Sathar J, et al.

Med J Malaysia, 2023 Jul;78(4):429-436.

PMID: 37518908

INTRODUCTION: Most evidence about the management of cancer and hematological malignancy in pregnancy are derived from retrospective observational studies with a small sample size. Availability of sufficiently large data has enabled evidence-based decision-making in this clinical dilemma.

MATERIALS AND METHODS: Retrospective study looking into patients diagnosed with acute leukemia or lymphoma in pregnancy from 1st January 2014 to 1st January 2020 in Ampang General Hospital including newly or previously diagnosed and relapsed disease RESULTS: 37 cases of acute leukemia or lymphoma in pregnancy occurred in 34 patients. Majority of acute leukemia or lymphoma in pregnancy diagnosed in 1st trimester or in the setting of previously established or relapsed disease was therapeutically terminated. Thirteen pregnancies treated with antenatal chemotherapy resulted in livebirths except one stillbirth. More adverse obstetric outcomes are observed in pregnancies that did not receive antenatal chemotherapy, but association did not reach statistical significance. There was no significant difference in fetal outcome between cohort with and without antenatal chemotherapy. No treatment related mortality was observed in pregnancies with antenatal chemotherapy. Overall survival for newly diagnosed acute leukemia in pregnancy is significantly better with antenatal chemotherapy versus no antenatal chemotherapy.

CONCLUSION: Treatment with chemotherapy in 2nd trimester of pregnancy onwards appears to have tolerable risks with favorable obstetric and fetal outcome. Deferment of treatment for acute leukemia in pregnancy to after delivery may cause increased risk of maternal and fetal adverse outcome.

Fulltext Acute lymphoblastic leukemia in relapse presenting as a breast lump: a case report

Cheong SK, Chong SM

Med J Malaysia, 1985 Mar;40(1):46-8.

PMID: 3868737

A 26-year-old assistant nurse suffered from acute lymphoblastic leukemia and was successfully treated with combination chemotherapy. 15 months later, she relapsed with a lump in her right breast. The significance of this finding is discussed.

Acute myeloid leukaemia with tell-tale computed tomography scans

Fadilah SA, Cheong SK, Maimunah A, Toh ST, Shamin AS

Postgrad Med J, 2001 Nov;77(913):733-4, 737-9.

PMID: 11677287

Fulltext All trans-retinoic acid in the treatment of promyelocytic leukaemia--a case report

Hoe TS, Hussin NH, Chum KW, Cheong SK

Med J Malaysia, 1992 Sep;47(3):225-7.

PMID: 1491649

A six year old Chinese boy with relapsed Acute Promyelocytic Leukaemia (APML) failed to respond to reinduction with Daunorubicin and Cytarabine infusion. He was successfully treated with all trans-Retinoic Acid (45 mg/m2/day) orally. After four weeks of treatment, he was in complete remission. The side effects of all trans-Retinoic Acid were negligible.

Fulltext Allogeneic haemopoietic stem cell transplantation using non-myeloablative conditioning--a local experience

Leong CF, Cheong SK, Fadilah SAW, Ainoon O, Hamidah NH

Med J Malaysia, 2003 Jun;58(2):229-35.

PMID: 14569743

Allogeneic haemopoietic stem cell transplantation was initially considered as a means of delivering supralethal doses of chemotherapy with or without total body irradiation for the treatment of malignancy. However, it has become clear that this mode of therapy does not eradicate the malignancy in many patients and its benefit is largely due to the immune mediated graft versus malignancy effect. This has led to development of alternative strategy to utilize a less intensive preparative regimen pre-transplantation that provides sufficient immunosuppression to achieve engraftment of an allogeneic stem cell graft, thus allowing the evolution of a graft versus malignancy effect post-transplantation. Since September 1999, we had carried out 10 cases of allogeneic peripheral blood stem cell transplantation: one case of aplastic anaemia, four cases of acute myeloid leukemia (AML) in first remission, and five cases of chronic myeloid leukemia (CML) in chronic phase. The preparative regimen was non-myeloablative comprising Fludarabine with Cyclophosphamide or Busulphan. Recovery from transplantation was rapid with no or brief period of neutropenia or thrombocytopenia. Engraftment was established by determining donor's short tandem repeats in the recipient's bone marrow at day 30, 60 and 100 post-transplantation. Seven cases (70%) show partial or complete donor's chimerism by day 30 indicating successful engraftment. No treatment mortality was noted at day 100. Graft versus host disease was generally limited. Up to the date of reporting, two patients with CML had graft failure, one was successfully re-transplanted later. Two patients with AML had since relapsed and passed away. The others remain alive and well. The cost of transplantation on average was estimated to be about a quarter of that using a myeloablative regimen. It appears that this treatment strategy is a promising approach for the management of blood disorders.

An in-house ELISA method for measuring surfactant protein A

Cheong KB, Cheong SK, Boo NY, Jemilah M, Ton SH

Malays J Pathol, 1995 Dec;17(2):91-6.

PMID: 8935133

An in-house enzyme-linked immunoabsorbant assay (ELISA) for SP-A was successfully developed using in-house polyclonal anti SP-A and a commercial polyclonal anti-rabbit immunoglobulin horseradish peroxidase conjugate system. The standard curve, generated by using 50 ng of SP-A to coat the plate and 1:500 dilution of polyclonal anti SP-A as a primary antibody, was linear for concentrations of SP-A ranging from 4 micrograms/l to 4000 micrograms/l and reproducible. Results of recovery study of SP-A from a known sample of tracheal aspirate ranged from 94%-114%. Intra- and inter-assay coefficients of variations were 2.7% and 5.6% respectively for a known sample of tracheal aspirate. Interference study showed that tracheal aspirate did not interfere with the assay. The assay developed was intended to be used for SP-A measurement in tracheal aspirates obtained from neonates with and without respiratory distress syndrome.

Fulltext An in-house ELISA method for quantification of circulating tissue factor

Tay SP, Cheong SK

Malays J Pathol, 2002 Jun;24(1):45-51.

PMID: 16329555

Tissue Factor (TF) is a low molecular weight transmembrane glycoprotein that initiates the clotting protease cascade. It is considered to be the principal regulator of the extrinsic coagulation pathway, hemostasis and thrombosis, as well as inflammation and cellular immune response. An in-house two-step direct sandwich ELISA (enzyme-linked immunosorbent assay) for immunological quantification of plasma TF was successfully developed. The assay employed a monoclonal antibody against human TF (1:400 dilution; 1250 ng/ml) and peroxidase-conjugated anti-TF IgG (1:1000 dilution; 2000 ng/ml) as capture and detecting antibodies respectively, whilst tetramethylbenzidine/H2O2 were utilized as substrates. Titration curves of recombinant TF were linear within 10 to 4000 pg/ml, with a detection limit of 36.31 pg/ml. It demonstrated low intra- (2.50 - 9.23 CV%) and inter-assays (5.65 - 13.57 CV%) variability, as well as satisfactory analytical recovery (91.55 - 103.95%) and good parallelism. The assay developed was intended to be applied for measurement of plasma TF levels in patients with thrombotic disorders.

An in-house assay for serum deoxythymidine kinase

Seah LH, Ton SH, Cheong SK, Hamidah NH

Malays J Pathol, 1991 Dec;13(2):109-13.

PMID: 1823092

An in-house method which utilizes 14C-thymidine as a substrate was used to assay deoxythymidine kinase in serum. The method is sensitive enough to detect normal levels of serum deoxythymidine kinase and the assay procedure also enables rapid handling of multiple samples. With a total reaction volume of 60 ul, the enzyme reaction was found to be linear with concentrations for up to 650 U/L of TK activity. On studying serum deoxythymidine kinase (s-TK) activity with incubation time, there was a proportional increase in activity with the length of incubation time. "Within-batch" precision showed a coefficient of variation (CV) of 4.7% for serum with extremely high s-TK levels and a CV of 8.8% for serum with normal s-TK levels. S-TK showed a CV of less than 16.0% in its activity when stored at -8 degrees C and at -20 degrees C. The normal reference range obtained for s-TK activity was 8.6 +/- 7.5 U/L.

An unusual cause of tremor in an elderly man

Fadilah SA, Raymond AA, Cheong SK

Postgrad Med J, 2001 Apr;77(906):268-269; discussion 277-8.

PMID: 11264499

Assessing donor chimerism using flow cytometry in paroxysmal nocturnal haemoglobinuria after stem cell transplantation--a case report

Azma RZ, Hamidah NH, Leong CF, Ainoon O, Cheong SK

Malays J Pathol, 2006 Dec;28(2):107-12.

PMID: 18376800

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemopoietic stem cell disorder arising from somatic mutation of the X-linked PIG-A gene which leads to deficiency of the glycosylphosphatidylinositol (GP1) membrane anchor proteins such as CD 59 (MIRL: membrane inhibitor of reactive lysis) and CD 55 (DAF: decay accelerating factor). Allogeneic peripheral blood stem cell transplant (PBSCT) is a curative mode of treatment in symptomatic PNH patients. Assessment of donor chimerism for PBSCT can be performed by various methods including short tandem repeat loci (STR) and variable number of tandem repeats (VNTR). Flow cytometry, which is much cheaper and faster, also can be used to assess engraftment in patients with PNH. Engrafted patients will show the presence of CD 55 and CD 59 on their red cells and white cells. We describe here the usefulness of flow cytometry in the assessment of donor chimerism following allogeneic PBSCT, in a case of PNH.

Assessment of P-gp and MRP1 activities using MultiDrugQuant Assay Kit: a preliminary study of correlation between protein expressions and its functional activities in newly diagnosed acute leukaemia patients

Fazlina N, Maha A, Zarina AL, Hamidah A, Zulkifli SZ, Cheong SK, et al.

Malays J Pathol, 2008 Dec;30(2):87-93.

PMID: 19291917

Multidrug resistance (MDR) is believed to be responsible for poor response of patients towards chemotherapy particularly patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). The best-characterized resistance mechanism is the one mediated by permeability-glycoprotein (P-gp) encoded by MDR1 gene, which is responsible for drug efflux. We studied P-gp and multidrug resistance-associated protein 1 (MRP1) expression and functional activities in 43 newly diagnosed acute leukemia cases (19 paediatric ALL cases and 24 adult AML cases). The expression and functional activities were examined using flow cytometry and MultiDrugQuant assay kit (involving calcein AM uptake and efflux). P-gp and MRP1 expression and its functional activities were observed in 68.4% of paediatric ALL. In adult AML cases, all cases expressed MRP1 and its functional activities but only 58.3% were positive for P-gp and its functional activities. We were able to show a significant correlation between the expression of the multidrug resistant protein (P-gp and MRP1) and their functional activity in adult AML and paediatric ALL samples.

Autoimmune thrombocytopenia and neutropenia after autologous peripheral blood stem cell transplantation

Wahid FS, Cheong SK, Sivagengei K

Acta Haematol., 2002;107(4):237-8.

PMID: 12053154

Fulltext BCR-ABL positive essential thrombocythaemia: a variant of chronic myelogerous leukaemia or a distinct clinical entity: a special case report

Fadilah SA, Cheong SK

Singapore Med J, 2000 Dec;41(12):595-8.

PMID: 11296785

A 37-year-old Malay man presented initially with the clinical picture of essential thrombocythaemia (ET) without the extreme leukocytosis, marked splenomegaly and low neutrophil alkaline phosphatase characteristic of chronic myelogenous leukaemia (CML). Bone marrow examination showed massive megakaryocytic hyperplasia; cytogenetic studies showed the presence of Philadelphia chromosome. The patient was treated with hydroxyurea that resulted in reduction in the platelet count. Seventeen months later, he presented with fever associated with tender massive splenomegaly. Bone marrow finding was consistent with chronic phase CML. The presence of a rearrangement involving the major breakpoint cluster region (M-bcr) on chromosome 22 was confirmed by reverse transcriptase-polymerase chain reaction. The clinical importance of finding the Philadelphia chromosome in patients who seem to have ET is in assessing prognosis. ET generally follows a chronic, indolent course. However, this patient who had Philadelphia chromosome underwent clinical transition to chronic phase CML17 months and blast crisis 29 months after presentation.

Bone marrow and stem cell transplantation: Malaysian experience

Gan G, Teh A, Chan L, Cheong S, Chang K, Ibrahim H

Bone Marrow Transplant, 2008 Aug;42 Suppl 1:S103-S105.

PMID: 18724278 DOI: 10.1038/bmt.2008.129

Malaysia conducted the first BMT in the country in 1987. Since then, there have been 1155 transplantations performed in a total of eight transplant centres. A majority of the transplantations were allogeneic, including myeloablative and nonmyeloablative. A vast majority of donors are HLA identical siblings. The mean age of transplanted patients was 26 years. The major reason for transplantation was hematological malignancies. The overall survival was 60% for allogeneic transplantation and 52% for autologous transplantation. The most common cause of death in transplanted patients was the underlying disease followed by infection-related complications. Currently, the government is expanding the existing public cord blood bank as well as the local donor registry.

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