MyMedR

Displaying all 4 publications

Abstract:

Sort:

Fulltext Block Compressive Sensing (BCS) Based Low Complexity, Energy Efficient Visual Sensor Platform with Joint Multi-Phase Decoder (JMD)

Ebrahim M, Chia WC, Adil SH, Raza K

Sensors (Basel), 2019 May 19;19(10).
PMID: 31109154 DOI: 10.3390/s19102309

Devices in a visual sensor network (VSN) are mostly powered by batteries, and in such a network, energy consumption and bandwidth utilization are the most critical issues that need to be taken into consideration. The most suitable solution to such issues is to compress the captured visual data before transmission takes place. Compressive sensing (CS) has emerged as an efficient sampling mechanism for VSN. CS reduces the total amount of data to be processed such that it recreates the signal by using only fewer sampling values than that of the Nyquist rate. However, there are few open issues related to the reconstruction quality and practical implementation of CS. The current studies of CS are more concentrated on hypothetical characteristics with simulated results, rather than on the understanding the potential issues in the practical implementation of CS and its computational validation. In this paper, a low power, low cost, visual sensor platform is developed using an Arduino Due microcontroller board, XBee transmitter, and uCAM-II camera. Block compressive sensing (BCS) is implemented on the developed platform to validate the characteristics of compressive sensing in a real-world scenario. The reconstruction is performed by using the joint multi-phase decoding (JMD) framework. To the best of our knowledge, no such practical implementation using off the shelf components has yet been conducted for CS.
Fulltext Treatment of spinal cord injury with mesenchymal stem cells

Liau LL, Looi QH, Chia WC, Subramaniam T, Ng MH, Law JX

Cell Biosci, 2020;10:112.
PMID: 32983406 DOI: 10.1186/s13578-020-00475-3

Background: Spinal cord injury (SCI) is the damage to the spinal cord that can lead to temporary or permanent loss of function due to injury to the nerve. The SCI patients are often associated with poor quality of life.
Results: This review discusses the current status of mesenchymal stem cell (MSC) therapy for SCI, criteria to considering for the application of MSC therapy and novel biological therapies that can be applied together with MSCs to enhance its efficacy. Bone marrow-derived MSCs (BMSCs), umbilical cord-derived MSCs (UC-MSCs) and adipose tissue-derived MSCs (ADSCs) have been trialed for the treatment of SCI. Application of MSCs may minimize secondary injury to the spinal cord and protect the neural elements that survived the initial mechanical insult by suppressing the inflammation. Additionally, MSCs have been shown to differentiate into neuron-like cells and stimulate neural stem cell proliferation to rebuild the damaged nerve tissue.
Conclusion: These characteristics are crucial for the restoration of spinal cord function upon SCI as damaged cord has limited regenerative capacity and it is also something that cannot be achieved by pharmacological and physiotherapy interventions. New biological therapies including stem cell secretome therapy, immunotherapy and scaffolds can be combined with MSC therapy to enhance its therapeutic effects.
Benchtop Isolation and Characterisation of Small Extracellular Vesicles from Human Mesenchymal Stem Cells

Tan KL, Chia WC, How CW, Tor YS, Show PL, Looi QHD, et al.

Mol Biotechnol, 2021 Sep;63(9):780-791.
PMID: 34061307 DOI: 10.1007/s12033-021-00339-2

The objective of this study is to develop a simple protocol to isolate and characterise small extracellular vesicles (sEVs) from human umbilical cord-derived MSCs (hUC-MSCs). hUC-MSCs were characterised through analysis of morphology, immunophenotyping and multidifferentiation ability. SEVs were successfully isolated by ultrafiltration from the conditioned medium of hUC-MSCs. The sEVs' size distribution, intensity within a specific surface marker population were measured with zetasizer or nanoparticle tracking analysis. The expression of surface and internal markers of sEVs was also assessed by western blotting. Morphology of hUC-MSCs displayed as spindle-shaped, fibroblast-like adherent cells. Phenotypic analysis by flow cytometry revealed that hUC-MSCs expressed MSC surface marker, including CD90, CD73, CD105, CD44 and exhibited the capacity for osteogenic, adipogenic and chondrogenic differentiation. Populations of sEVs with CD9, CD63 and CD81 positive were detected with size distribution in the diameter of 63.2 to 162.5 nm. Typical sEVs biomarkers such as CD9, CD63, CD81, HSP70 and TSG101 were also detected with western blotting. Our study showed that sEVs from hUC-MSCs conditioned medium were successfully isolated and characterised. Downstream application of hUC-MSCs-sEVs will be further explored.
Multiplex STR panel for assessment of chimerism following hematopoietic stem cell transplantation (HSCT)

Chia WC, Khoo TS, Abdul Wahid SFS, Razak NFA, Alauddin H, Raja Sabudin RZA, et al.

Ann Hematol, 2019 May;98(5):1279-1291.
PMID: 30783731 DOI: 10.1007/s00277-019-03626-w

Short tandem repeat (STR) analysis is used in chimerism monitoring after allogeneic hematopoietic stem cell transplantation (HSCT) for patients with various hematologic malignancies. Commercial forensic STR kits often contain loci with huge differences in power of discrimination (PD) across populations, causing some loci to be less informative for chimerism analysis in certain populations. This study aimed to construct a new STR multiplex panel with highly informative loci for efficient chimerism analysis. Thirteen STR markers which exhibit high PD (> 0.9) in at least 80% of 50 populations globally were selected to form a new panel and used in STR analysis of 253 Malaysian subjects. Cumulative power of discrimination (CPD) and combined power of exclusion (CPE) were determined from 253 Malaysian individuals. Loci informativity was assessed and compared to the commercial AmpFLSTR Identifiler PCR Amplification kit in 14 donor-recipient pairs. The new panel had detected 202 unique alleles including five novel alleles from the 253 individuals with high CPD and CPE (> 0.99999999999999999 and > 0.999999997 respectively). All loci from the new panel in the donor-recipient pair analysis showed higher than 50% informativity, while five loci from the commercial kit demonstrated lower than 50% informativity. Four loci from the new panel ranked the highest informativity. A sequenced allelic ladder which consists of 202 unique alleles from the 253 subjects was also developed to ensure accurate allele designation. The new 13-loci STR panel, thus, could serve as an additional powerful, accurate, and highly informative panel for chimerism analysis for HSCT patients.