Mohd Tap R.,Institute for Medical Research IMR
Mycopathologia | Year: 2012
Prototheca wickerhamii isolated from blood of 61-year-old kidney transplant patient was described. Although it is classified as an alga (genus Chlorella), the disease, protothecosis, is included under mycoses because of its clinical pathological presentations. Colony characteristics of P. wickerhamii are indistinguishable from other yeast-like organisms like Cryptococcus and Candida. Fortunately, commercial identification system for yeast can be used to identify this organism to the species level. Electron microscopy demonstrated "morula" or daisy-like appearance of its endosporulating sporangia. The organism was sensitive to amphotericin B by E test method. Even though human protothecosis is uncommon, it cannot be ignored because it is emerging as an opportunistic infection in immunosuppressed individuals. To our knowledge, this is the first reported case of disseminated algaemia due to P. wickerhamii in Malaysia.
Halim N.S.S.A.,Universiti Sains Malaysia |
Fakiruddin K.S.,Institute for Medical Research IMR |
Ali S.A.,Universiti Sains Malaysia |
Yahaya B.H.,Universiti Sains Malaysia
International Journal of Molecular Sciences | Year: 2014
Mesenchymal stem cells (MSCs) hold tremendous potential for therapeutic use in stem cell-based gene therapy. Ex vivo genetic modification of MSCs with beneficial genes of interest is a prerequisite for successful use of stem cell-based therapeutic applications. However, genetic manipulation of MSCs is challenging because they are resistant to commonly used methods to introduce exogenous DNA or RNA. Herein we compared the effectiveness of several techniques (classic calcium phosphate precipitation, cationic polymer, and standard electroporation) with that of microporation technology to introduce the plasmid encoding for angiopoietin-1 (ANGPT-1) and enhanced green fluorescent protein (eGFP) into human adipose-derived MSCs (hAD-MSCs). The microporation technique had a higher transfection efficiency, with up to 50% of the viable hAD-MSCs being transfected, compared to the other transfection techniques, for which less than 1% of cells were positive for eGFP expression following transfection. The capability of cells to proliferate and differentiate into three major lineages (chondrocytes, adipocytes, and osteocytes) was found to be independent of the technique used for transfection. These results show that the microporation technique is superior to the others in terms of its ability to transfect hAD-MSCs without affecting their proliferation and differentiation capabilities. Therefore, this study provides a foundation for the selection of techniques when using ex vivo gene manipulation for cell-based gene therapy with MSCs as the vehicle for gene delivery. © 2014 by the authors; licensee MDPI, Basel, Switzerland.
Kardia E.,Universiti Sains Malaysia |
Yusoff N.M.,Universiti Sains Malaysia |
Zakaria Z.,Institute for Medical Research IMR |
Yahaya B.,Universiti Sains Malaysia
Journal of Aerosol Medicine and Pulmonary Drug Delivery | Year: 2014
Background: Cell-based therapy has great potential to treat patients with lung diseases. The administration of cells into an injured lung is one method of repairing and replacing lost lung tissue. However, different types of delivery have been studied and compared, and none of the techniques resulted in engraftment of a high number of cells into the targeted organ. In this in vitro study, a novel method of cell delivery was introduced to investigate the possibility of delivering aerosolized skin-derived fibroblasts. Methods: Skin-derived fibroblasts were trypsinized and resuspended in growth medium. A syringe filled with cells (105 cells/mL) was attached to MicroSprayer® Aerosolizer, a device that can modify a liquid into an aerosol. The tip of the MicroSprayer Aerosolizer was channeled into a T25 flask containing growth medium. Survivability following aerosolization was observed on a daily basis. HeLa cells were used for comparison. The same aerosolization and culture methods were used to treat HeLa cells. Results: One day following aerosolization, skin-derived fibroblasts showed no sign of vacuolation due to cell stress. They attached to the surface of the flask, indicating that most of them survived aerosolization. The surviving cells were also able to proliferate rapidly, forming a confluent monolayer of cells at day 4. In contrast, HeLa cells were unable to proliferate even after 21 days of culture. Conclusions: This study provides the first evidence that cells can be aerosolized without the risk of low cell survivability and stress. The high survival rate of fibroblast cells following aerosolization illustrates the potential for delivering of such cells in future aerosol cell-based therapy to treat lung diseases. © Copyright 2014, Mary Ann Liebert, Inc.
Teow S.-Y.,Institute for Medical Research IMR |
Nordin A.C.,University Technology of MARA |
Nordin A.C.,Universiti Sains Malaysia |
Ali S.A.,Universiti Sains Malaysia |
Khoo A.S.-B.,Institute for Medical Research IMR
Advances in Virology | Year: 2016
Nanometre-sized vesicles, also known as exosomes, are derived from endosomes of diverse cell types and present in multiple biological fluids. Depending on their cellular origins, the membrane-bound exosomes packed a variety of functional proteins and RNA species. These microvesicles are secreted into the extracellular space to facilitate intercellular communication. Collective findings demonstrated that exosomes from HIV-infected subjects share many commonalities with Human Immunodeficiency Virus Type I (HIV-1) particles in terms of proteomics and lipid profiles. These observations postulated that HIV-resembled exosomes may contribute to HIV pathogenesis. Interestingly, recent reports illustrated that exosomes from body fluids could inhibit HIV infection, which then bring up a new paradigm for HIV/AIDS therapy. Accumulative findings suggested that the cellular origin of exosomes may define their effects towards HIV-1. This review summarizes the two distinctive roles of exosomes in regulating HIV pathogenesis. We also highlighted several additional factors that govern the exosomal functions. Deeper understanding on how exosomes promote or abate HIV infection can significantly contribute to the development of new and potent antiviral therapeutic strategy and vaccine designs. © 2016 Sin-Yeang Teow et al.
Wan-Norafikah O.,University Technology of MARA |
Wan-Norafikah O.,University of Malaya |
Nazni W.A.,Institute for Medical Research IMR |
Lee H.L.,Institute for Medical Research IMR |
And 2 more authors.
Asian Biomedicine | Year: 2013
Background: Insects control using insecticides is used extensively and intensively in vector control programs in many countries including Malaysia. Because of this, mosquito species have been found to develop various levels of resistance towards these insecticides, leading to failure in vector control activities. Objectives: We determined permethrin resistance status in laboratory susceptible, permethrin-selected, and field strains of Aedes albopictus. Methods: The susceptibility status of laboratory susceptible strain, permethrin-selected strain, and four field strains of Aedes albopictus collected from Kuala Lumpur were determined using three standard laboratory tests, WHO larval bioassay, WHO adult mosquito bioassay, and microassay of mixed function oxidases (MFOs). Results: The LC50 values of permethrin-selected strain and field strains obtained from the WHO larval bioassay were almost two times higher (0.38-0.44 mg/L) than the LC50 value of the laboratory strain (0.20 mg/L). In the WHO adult bioassay, the susceptibility of permethrin-exposed of both permethrin-selected strain, and field strains (LT50 = 19.39 to 20.65 min) were reduced for 1.31 to 1.72 times after been exposed to the synergist, piperonyl butoxide (PBO) prior to permethrin. Complete mortalities were also recorded in both permethrin-exposed and PBO + permethrin-exposed Ae. albopictus of all strains, twenty-four hours post-exposure. For the MFOs enzyme microassay, a significant difference (p <0.05) in the mean absorbance of elevated oxidase activity at 630 nm was observed between all strains of both the non-exposed and PBO-exposed Ae. albopictus. Strong and significant positive correlations were also observed between LT50 values of permethrin-exposed and PBO + permethrinexposed with oxidase level in Ae. albopictus tested (r = 0.943; p <0.05). Conclusion: These results indicate the association of oxidase activity with permethrin resistance development in Ae. albopictus.