Introduction: During the last three decades hematopoietic stem cell transplantation (HSCT) has become a well-established treatment for many hematologic malignancies. The most important limitation for HSC transplantation is the low number of hematopoietic stem cells (HSC) that can lead to delayed engraftment or graft failures. Numerous attempts have been made to improve in vitro HSC expansion via optimization of various methods such as isolation techniques, supplementing with growth factors, utilizing stromal cells as feeder layer and other culture conditions. Objective: This project is aimed to decipher the efficiency of an isolation technique and retrieval of culture expanded HSC from feeder layer using two different harvesting methods. Materials and Methods: Hematopoietic stem cells from human umbilical cord blood were isolated via MACS mediated CD34+ double sorting. Then, the cells were cultured onto MSC feeder layer for 3 and 5 days. Culture expanded cells were harvested using two different harvesting method namely cell aspiration and trypsinization methods. Hematopoietic stem cell expansion index were calculated based on harvesting methods for each time point. Results: The numbers of HSC isolated from human umbilical cord blood were 1.64 x 106 and 1.20 x106 cells at single and double sortings respectively. Although the number of sorted cells diminished at the second sorting yet the yield of CD34+ purity has increased from 43.73% at single sorting to 81.40% at double sorting. Employing the trypsinization method, the HSC harvested from feeder layer showed a significant increase in expansion index (EI) as compared to the cell aspiration harvesting method (p≤ 0.05). However, the purity of CD34+ HSC was found higher when the cells were harvested using aspiration method (82.43%) as compared to the trypsinization method (74.13%). Conclusion: A pure population of CD34+ HSC can be retrieved when the cells were double sorted using MACS and expanded in culture after being harvested using cell aspiration method.
Hematopoietic Stem Cells

Background: MicroRNAs (miRNAs) have a crucial role in gene expression regulation and protein synthesis, especially in the central nervous system. In developing mouse embryos a novel miRNA, miR-3099, is highly expressed, particularly in the central nervous system. This study aims to determine the expression of miR-3099 during cellular differentiation of 46C mouse embryonic stem cells after neural induction with N2/B27 medium. Methods: 46C mouse embryonic stem cells were subjected to neural induction with N2/B27 medium. At 0, 3, 7, 11, 17, and 22 days after neural induction, the cells were screened for various pluripotent, progenitor, and differentiating/differentiated cells markers by immunocytochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR). Stem-loop pulse RT-PCR was performed to determine the expression of miR-3099 at all selected time points after neural induction. Results: Our findings showed that after induction, mouse embryonic stem cells differentiated into heterogeneous pools of cells containing neurons, astrocytes, and oligodendrocytes. Mouse embryonic stem cells and neural progenitor/precursor cells were also present in culture up to day 22 as indicated by RT-PCR analysis. Elucidation of miR-3099 expression during in vitro neural induction revealed that this miRNA was expressed throughout the differentiation process of 46C mouse embryonic stem cells. miR-3099 was expressed at higher levels on day 11, 17, and 22 as compared to day 0, 3 and 7 after neural induction. Conclusion: The level of miR-3099 expression was higher in differentiated mouse embryonic stem cells after neural induction. This finding suggested that miR-3099 might play a role in regulating neural stem cell differentiation. However, further characterisation of miR-3099 in a better characterised or optimised differentiated neural stem cell culture would provide increased understanding of the cellular function and molecular targets of miR-3099, especially in neuron development.

Introduction: Down syndrome (DS) is caused by trisomy of human chromosome 21 (HSA21). Motor dysfunction due to hypotonia has limited labour productivity and have significant effects on socio-economic status in DS individuals. Ts1Cje, a mouse model of DS that exhibits muscle weakness was employed, to investigate the expression profile of selected trisomic and disomic genes involved in skeletal muscle structure and function. Methods: Quadriceps and triceps were harvested from the Ts1Cje (C57BL/6) postnatal day 60-70 mice and corresponding wild-type littermates. Total RNA extracted from these tissues was subjected for quantitative expression profiling of three trisomic genes (Itsn1, Synj1 and Rcan1) involved in neurotransmission and six disomic genes (Lamc1, Leprel1, Myl6b, Msn, Pgm5 and Tmod1) essential for maintenance of muscle structure and function. Real-time quantitative PCR method was used for the profiling. Results: Differential gene expression in DS is reflected by 1.5-fold or more increase in the level of expression as predicted by the gene dosage imbalance hypothesis. The analysis showed no significant changes in the expression level of trisomic genes (Itsn1, Synj1 and Rcan1). On contrary, disomic genes, Leprel1 and Pgm5, were upregulated for more than 1.5-fold in DS quadriceps whereas Lamc1, Myl6b and Pgm5 were upregulated for more than 1.5 fold in DS triceps as compared to the wild-type group. Conclusions: Our findings suggest that the dysregulation of Lamc1, Leprel1, Myl6b and Pgm5 genes is associated to muscle weakness seen in Ts1Cje and may play a role in molecular pathogenesis of muscle weakness in DS.

Introduction: MiR-3099 was reported to play a role in neuronal cell differentiation/function in the brain during late embryonic and early neonatal development. To further explore its potential regulatory effects on embryonic brain development, this study aims to construct and validate an expression vector of miR-3099 for future gain-of-function and loss-of-function studies. Methods: pCAG-eGFP vector was modified to include IRES2 and miR-3099 with 150bp upstream and downstream genomic sequences. The newly constructed vector, pCAG-miR-3099-IRES2-eGFP, consists of CAG promoter. The in vitro expression level of miR-3099 was measured using stem-loop RT-qPCR after it was transfected into 293FT cell. Later, the vector was electroporated into the embryonic brain at E15.5. Three days later, the E18.5 embryonic brain was harvested and cryopreserved. Immunohistochemistry was performed by using antibody against eGFP to validate the in utero expression of the transgene in the neocortex of the brain. Results: Our finding showed that, the expression level of miR-3099 was significantly upregulated (p<0.001) in cells transfected with miR-3099 vector as compared to both negative and empty plasmid control groups. In addition, the expression of eGFP was noted in the brain section indicating that the vectors with or without miR-3099 transgene were successfully transfected into and expressed in the neocortex upon electroporation. Conclusion: The bicistronic expression vector of miR-3099 which was driven by the CAG promoter was successfully constructed, validated and sufficiently delivered to brain cells via the in utero electroporation approach. The regulatory roles of miR-3099 in embryonic brain development can be manipulated using similar approach.

Introduction: One of the commonly used techniques for mutation screening is High Resolution Melting (HRM) analysis. HRM is a post PCR method that relies on the detection of the fluorescent signals acquired due to the release of DNA intercalated dyes upon the melting of dsDNA to ssDNA. The method is simple, inexpensive and does not require post PCR-handling, making it suitable for high throughput screening. Methods: This study aimed to develop and validate HRM technique for the screening of two disease-associated single nucleotide polymorphisms (SNPs) namely BDNF rs6265 and DAT1 rs40184 using a total of 30 gDNA samples. The obtained results were confirmed and validated by sequencing. Results: HRM analysis showed that the predicted genotypes of BDNF rs6265 and DAT1 rs40184 among all the gDNA samples were in 100% concordance with the sequencing results, making it an accurate and sensitive method for the detection of SNPs. Conclusions: The application of HRM can accurately determine the genotype of BDNF rs6265 and DAT1 rs40184 SNPs, making it a promising tool for rapid and high-throughput screening of targeted SNPs in a large population study.

BACKGROUND/OBJECTIVES: Recently, the recommended nutrient intakes (RNI) for vitamin D for Malaysian aged 1–70 yrs has been revised from 5 µg/day to 15 µg/day. This study is aimed to assess the adequacy of vitamin D intake based on revised RNI and to recommend several dietary strategies to increase total vitamin D intake. SUBJECTS/METHODS: Vitamin D intake from both food and supplement of 217 pregnant women was assessed using a validated food frequency questionnaire. Hypothetical effect of expanded supplementation and food fortifications strategies were modelled using the consumption data. RESULTS: The results revealed that more than half (67.7%) of pregnant women had inadequate vitamin D intake (RNI < 15 µg/day). The modelling results demonstrated the potential of universal provision of 10 µg/day of multivitamins supplements in increasing vitamin D intake.Moreover, mandatory fortification of both milk and malted drink at single level of 5 µg/serving would lead to increase in vitamin D intake of Malaysians, particularly pregnant women. CONCLUSIONS The outcome of this study can be used as a reference for public health professionals to re-evaluate the existing Malaysian food fortification policies and supplementation recommendation for vitamin D for pregnant women.

BACKGROUND/OBJECTIVES: Recently, the recommended nutrient intakes (RNI) for vitamin D for Malaysian aged 1–70 yrs has been revised from 5 µg/day to 15 µg/day. This study is aimed to assess the adequacy of vitamin D intake based on revised RNI and to recommend several dietary strategies to increase total vitamin D intake. SUBJECTS/METHODS: Vitamin D intake from both food and supplement of 217 pregnant women was assessed using a validated food frequency questionnaire. Hypothetical effect of expanded supplementation and food fortifications strategies were modelled using the consumption data. RESULTS: The results revealed that more than half (67.7%) of pregnant women had inadequate vitamin D intake (RNI < 15 µg/day). The modelling results demonstrated the potential of universal provision of 10 µg/day of multivitamins supplements in increasing vitamin D intake.Moreover, mandatory fortification of both milk and malted drink at single level of 5 µg/serving would lead to increase in vitamin D intake of Malaysians, particularly pregnant women. CONCLUSIONS The outcome of this study can be used as a reference for public health professionals to re-evaluate the existing Malaysian food fortification policies and supplementation recommendation for vitamin D for pregnant women.

Background: Impulse control behaviours are repetitive and excessive activities that may be subsyndromal and not fulfil the criteria for impulse control disorder. These activities have potential to negatively impact on the daily lives of sufferers. We conducted a study to investigate the prevalence of impulse control behaviours and its associated features in Parkinson’s disease in our population. Methods: We conducted a prospective cross-sectional study on consecutive patients attending neurology clinic. Inclusion criteria include idiopathic Parkinson’s disease patients with Hoehn & Yahr stage I-IV. Eighty patients were enrolled and screened for impulse control behaviours using the Questionnaire for Impulsive-Compulsive Disorder for Parkinson’s disease (QUIP). Results: Prevalence of impulse control behaviours among our cohort was 11.3%; the features significantly associated with it were higher level of education (p=0.02), advanced stage of disease (p=0.03) and higher levodopa dosage (p= 0.01). The commonest impulse control behaviour in our cohort was compulsive medication use (7.5%), followed by hobbyism (6.3%), hypersexuality (5%), compulsive buying (3.75%), punding (2.5%), walkabout (2.5%), compulsive eating (1.25%) and pathological gambling (1.3%). Conclusions: There is an association between impulse control behaviour and higher levodopa dosage in a study on patients with Parkinson’s disease in Malaysia. We also found a low prevalence of pathological gambling as compared to studies performed in the West.
Disruptive, Impulse Control, and Conduct Disorders ; Parkinson Disease