Displaying publications 1 - 20 of 43 in total

Abstract:
Sort:
  1. Abd Razak NA, Abu Osman NA, Kamyab M, Wan Abas WA, Gholizadeh H
    Am J Phys Med Rehabil, 2014 May;93(5):437-44.
    PMID: 24429510 DOI: 10.1097/PHM.0b013e3182a51fc2
    This report compares wrist supination and pronation and flexion and extension movements with the common body-powered prosthesis and a new biomechatronics prosthesis with regard to patient satisfaction and problems experienced with the prosthesis. Fifteen subjects with traumatic transradial amputation who used both prosthetic systems participated in this study. Each subject completed two questionnaires to evaluate their satisfaction and problems experienced with the two prosthetic systems. Satisfaction and problems with the prosthetic's wrist movements were analyzed in terms of the following: supination and pronation; flexion and extension; appearance; sweating; wounds; pain; irritation; pistoning; smell; sound; durability; and the abilities to open a door, hold a cup, and pick up or place objects. This study revealed that the respondents were more satisfied with the biomechatronics wrist prosthesis with regard to supination and pronation, flexion and extension, pain, and the ability to open a door. However, satisfaction with the prosthesis showed no significant differences in terms of sweating, wounds, irritation, pistoning, smell, sound, and durability. The abilities to hold a cup and pick up or place an object were significantly better with the body-powered prosthesis. The results of the survey suggest that satisfaction and problems with wrist movements in persons with transradial amputation can be improved with a biomechatronics wrist prosthesis compared with the common body-powered prosthesis.
  2. Gholizadeh H, Abu Osman NA, Kamyab M, Eshraghi A, Lúvíksdóttir AG, Wan Abas WA
    Am J Phys Med Rehabil, 2012 Oct;91(10):894-8.
    PMID: 22173083
    The effects of Seal-In X5 and Dermo liner (Össur) on suspension and patient's comfort in lower limb amputees are unclear. In this report, we consider the case of a 51-yr-old woman with bilateral transtibial amputation whose lower limbs were amputated because of peripheral vascular disease. The subject had bony and painful residual limbs, especially at the distal ends. Two prostheses that used Seal-In X5 liners and a pair of prostheses with Dermo liners were fabricated, and the subject wore each for a period of 2 wks. Once the 2 wks had passed, the pistoning within the socket was assessed and the patient was questioned as to her satisfaction with both liners. This study revealed that Seal-In X5 liner decreased the residual limb pain experienced by the patient and that 1-2 mm less pistoning occurred within the socket compared with the Dermo liner. However, the patient needed to put in extra effort for donning and doffing the prosthesis. Despite this, it is clear that the Seal-In X5 liner offers a viable alternative for individuals with transtibial amputations who do not have enough soft tissue around the bone, especially at the end of the residual limb.
  3. Eshraghi A, Abu Osman NA, Karimi MT, Gholizadeh H, Ali S, Wan Abas WA
    Am J Phys Med Rehabil, 2012 Dec;91(12):1028-38.
    PMID: 23168378 DOI: 10.1097/PHM.0b013e318269d82a
    The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees.
  4. Wan Abas WA
    Biomed Mater Eng, 1995;5(2):59-63.
    PMID: 7655319
    The response of human skin to "stress relaxation" tests at low loads in vitro was investigated. A number of behaviours, other than those already well established and documented, were observed. The significant behaviours are pure recovery and relaxation-recovery. Other behaviours observed are temporary stress recovery during the relaxation process, and momentary sudden non-linear drop in stress value followed by a second relaxation. The pure recovery and relaxation-recovery responses are repeatable. The latter represents the transitional response between the well-known behaviour of stress relaxation and the behaviour of stress recovery.
  5. Wan Abas WA
    Biomed Mater Eng, 1994;4(7):473-86.
    PMID: 7881331
    The response of human skin to biaxial stretch tests in vivo was investigated and compared to the response to uniaxial tension. The results obtained illustrate the nonlinear, anisotropic, and viscoelastic (time-dependent) properties of skin under biaxial stretch. Preconditioning in the load-extension response was found not to be prominent. The results also suggest that the response of skin to a biaxial stretch in vivo is qualitatively similar to that in vitro. Values of the terminal stiffness and limit strain of skin under a biaxial stretch are found.
  6. Wan Abas WA, Asseli MR
    Biomed Mater Eng, 1994;4(7):463-71.
    PMID: 7881330
    Local strains acting across an area of skin loaded uniaxially in vivo are converted to stresses using the standard elastic formulae. The stress values are compared to those obtained using the classical Bossinesq and Michell stress functions. The results indicate that these functions are capable of describing the response of the skin, both in the low load and the high load regions.
  7. Low WS, Wan Abas WA
    Biomed Res Int, 2015;2015:239362.
    PMID: 25977918 DOI: 10.1155/2015/239362
    Circulating tumor cells (CTCs) are tumor cells that have detached from primary tumor site and are transported via the circulation system. The importance of CTCs as prognostic biomarker is leveraged when multiple studies found that patient with cutoff of 5 CTCs per 7.5 mL blood has poor survival rate. Despite its clinical relevance, the isolation and characterization of CTCs can be quite challenging due to their large morphological variability and the rare presence of CTCs within the blood. Numerous methods have been employed and discussed in the literature for CTCs separation. In this paper, we will focus on label free CTCs isolation methods, in which the biophysical and biomechanical properties of cells (e.g., size, deformability, and electricity) are exploited for CTCs detection. To assess the present state of various isolation methods, key performance metrics such as capture efficiency, cell viability, and throughput will be reported. Finally, we discuss the challenges and future perspectives of CTC isolation technologies.
  8. Choi JR, Pingguan-Murphy B, Wan Abas WA, Noor Azmi MA, Omar SZ, Chua KH, et al.
    Biochem Biophys Res Commun, 2014 May 30;448(2):218-24.
    PMID: 24785372 DOI: 10.1016/j.bbrc.2014.04.096
    Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O2 tension on their functional properties has not been well determined. In this study, we investigated the effects of O2 tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O2) and hypoxia (2% O2). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O2 tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.
  9. Arifin N, Abu Osman NA, Ali S, Wan Abas WA
    Biomed Eng Online, 2014;13(1):23.
    PMID: 24597518 DOI: 10.1186/1475-925X-13-23
    Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet.
  10. Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Arifin N, Wan Abas WA
    Biomed Eng Online, 2014;13:1.
    PMID: 24410918 DOI: 10.1186/1475-925X-13-1
    Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems).
  11. Yong KW, Wan Safwani WK, Xu F, Wan Abas WA, Choi JR, Pingguan-Murphy B
    Biopreserv Biobank, 2015 Aug;13(4):231-9.
    PMID: 26280501 DOI: 10.1089/bio.2014.0104
    Mesenchymal stem cells (MSCs) hold many advantages over embryonic stem cells (ESCs) and other somatic cells in clinical applications. MSCs are multipotent cells with strong immunosuppressive properties. They can be harvested from various locations in the human body (e.g., bone marrow and adipose tissues). Cryopreservation represents an efficient method for the preservation and pooling of MSCs, to obtain the cell counts required for clinical applications, such as cell-based therapies and regenerative medicine. Upon cryopreservation, it is important to preserve MSCs functional properties including immunomodulatory properties and multilineage differentiation ability. Further, a biosafety evaluation of cryopreserved MSCs is essential prior to their clinical applications. However, the existing cryopreservation methods for MSCs are associated with notable limitations, leading to a need for new or improved methods to be established for a more efficient application of cryopreserved MSCs in stem cell-based therapies. We review the important parameters for cryopreservation of MSCs and the existing cryopreservation methods for MSCs. Further, we also discuss the challenges to be addressed in order to preserve MSCs effectively for clinical applications.
  12. Choi JR, Hu J, Feng S, Wan Abas WA, Pingguan-Murphy B, Xu F
    Biosens Bioelectron, 2016 May 15;79:98-107.
    PMID: 26700582 DOI: 10.1016/j.bios.2015.12.005
    Lateral flow assays (LFAs) have currently attracted broad interest for point-of-care (POC) diagnostics, but their application has been restricted by poor quantification and limited sensitivity. While the former has been currently solved to some extent by the development of handheld or smartphone-based readers, the latter has not been addressed fully, particularly the potential influences of environmental conditions (e.g., temperature and relative humidity (RH)), which have not yet received serious attention. The present study reports the use of a portable temperature-humidity control device to provide an optimum environmental requirement for sensitivity improvement in LFAs, followed by quantification by using a smartphone. We found that a RH beyond 60% with temperatures of 55-60°C and 37-40°C produced optimum nucleic acid hybridization and antigen-antibody interaction in LFAs, respectively representing a 10-fold and 3-fold signal enhancement over ambient conditions (25°C, 60% RH). We envision that in the future the portable device could be coupled with a fully integrated paper-based sample-to-answer biosensor for sensitive detection of various target analytes in POC settings.
  13. Choi JR, Tang R, Wang S, Wan Abas WA, Pingguan-Murphy B, Xu F
    Biosens Bioelectron, 2015 Dec 15;74:427-39.
    PMID: 26164488 DOI: 10.1016/j.bios.2015.06.065
    Nucleic acid testing (NAT), as a molecular diagnostic technique, including nucleic acid extraction, amplification and detection, plays a fundamental role in medical diagnosis for timely medical treatment. However, current NAT technologies require relatively high-end instrumentation, skilled personnel, and are time-consuming. These drawbacks mean conventional NAT becomes impractical in many resource-limited disease-endemic settings, leading to an urgent need to develop a fast and portable NAT diagnostic tool. Paper-based devices are typically robust, cost-effective and user-friendly, holding a great potential for NAT at the point of care. In view of the escalating demand for the low cost diagnostic devices, we highlight the beneficial use of paper as a platform for NAT, the current state of its development, and the existing challenges preventing its widespread use. We suggest a strategy involving integrating all three steps of NAT into one single paper-based sample-to-answer diagnostic device for rapid medical diagnostics in the near future.
  14. Ali S, Abu Osman NA, Eshraghi A, Gholizadeh H, Abd Razak NA, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2013 Nov-Dec;28(9-10):994-9.
    PMID: 24161521 DOI: 10.1016/j.clinbiomech.2013.09.004
    Transtibial amputees encounter stairs and steps during their daily activities. The excessive pressure between residual limb/socket may reduce the walking capability of transtibial prosthetic users during ascent and descent on stairs. The purposes of the research were to evaluate the interface pressure between Dermo (shuttle lock) and Seal-In X5 (prosthetic valve) interface systems during stair ascent and descent, and to determine their satisfaction effects on users.
  15. Ali S, Osman NA, Mortaza N, Eshraghi A, Gholizadeh H, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2012 Nov;27(9):943-8.
    PMID: 22795863 DOI: 10.1016/j.clinbiomech.2012.06.004
    The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. Liners provide a comfortable interface by adding a soft cushion between the residual limb and the socket. The Dermo and the Seal-In X5 liner are two new interface systems and, due to their relative infancy, very little are known about their effect on patient satisfaction. The aim of this study was to compare the interface pressure with these two liners and their effect on patient satisfaction.
  16. Eshraghi A, Abu Osman NA, Gholizadeh H, Ali S, Sævarsson SK, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2013 Jan;28(1):55-60.
    PMID: 23157843 DOI: 10.1016/j.clinbiomech.2012.10.002
    Different suspension systems that are used within prosthetic devices may alter the distribution of pressure inside the prosthetic socket in lower limb amputees. This study aimed to compare the interface pressure of a new magnetic suspension system with the pin/lock and Seal-In suspension systems.
  17. Ibrahim F, Ooi KF, Ismail NA, Taib MN, Wan Abas WA
    Conf Proc IEEE Eng Med Biol Soc, 2007 2 7;2005:4130-3.
    PMID: 17281142
    This paper describes the water compartments in healthy subjects and dengue patients on the day of defervescence of fever using bioelectrical impedance analysis. A total of 223 healthy subjects (65 males and 158 females) and 210 dengue patients (119 males and 91 females) in Hospital Universiti Kebangsaan Malaysia (HUKM), were studied. The ages for healthy subjects vary between 14 and 60 years old with mean age of 26.05 years while the ages for the dengue patients vary between 12 and 83 years old with mean age of 30.14 years. The parameters of water compartments investigated were total body water (TBW), extracellular water (ECW) and intracellular water (ICW). There were significant difference between healthy subjects and dengue patients for both male (p<0.05) and female (p<0.001) beginning on fever day 0 till fever day 4. The mean TBW and ECW values of dengue patients obtained were found to be higher than the normal healthy subjects while the mean ICW was lower. The mean TBW and ICW for male were higher than female while the mean ECW for male was lower than female for healthy subjects and dengue patients.
  18. Choi JR, Hu J, Wang S, Yang H, Wan Abas WA, Pingguan-Murphy B, et al.
    Crit Rev Biotechnol, 2017 Feb;37(1):100-111.
    PMID: 26912259
    Dengue endemic is a serious healthcare concern in tropical and subtropical countries. Although well-established laboratory tests can provide early diagnosis of acute dengue infections, access to these tests is limited in developing countries, presenting an urgent need to develop simple, rapid, and robust diagnostic tools. Point-of-care (POC) devices, particularly paper-based POC devices, are typically rapid, cost-effective and user-friendly, and they can be used as diagnostic tools for the prompt diagnosis of dengue at POC settings. Here, we review the importance of rapid dengue diagnosis, current dengue diagnostic methods, and the development of paper-based POC devices for diagnosis of dengue infections at the POC.
  19. Wan Safwani WK, Wong CW, Yong KW, Choi JR, Mat Adenan NA, Omar SZ, et al.
    Cytotechnology, 2016 Oct;68(5):1859-72.
    PMID: 26728363 DOI: 10.1007/s10616-015-9939-9
    The need to have a better and safer culture condition for expansion of human mesenchymal stem cells (MSCs) is crucial particularly to prevent infection and immune rejection. This is normally associated with the use of animal-based serum in the culture media for cell expansion. The aim of this study is to investigate alternative culture conditions which may provide better and safer environment for cell growth. In the present study, human adipose-derived stem cells (ASCs) at passage 3 were subjected to treatment in 4 conditions: (1) 21 % O2 with fetal bovine serum (FBS), (2) 21 % O2 without FBS, (3) 2 % O2 with FBS and (4) 2 % O2 without FBS followed by subsequent analysis of their phenotype, viability and functionality. We observed that ASCs cultured in all conditions present no significant phenotypic changes. It was found that ASCs cultured in 2 % O2 without serum showed an increase in viability and growth to a certain extent when compared to those cultured in 21 % O2 without serum. However, ASCs cultured in 2 % O2 without serum displayed a relatively low adipogenic and osteogenic potential. On the other hand, interestingly, there was a positive enhancement in chondrogenic differentiation of ASCs cultured in 21 % O2 without serum. Our findings suggest that different culture conditions may be suitable for different indications. In summary, ASCs cultured in serum-free condition can still survive, proliferate and undergo subsequent adipogenic, osteogenic and chondrogenic differentiation. Therefore, FBS is feasible to be excluded for culture of ASCs, which avoids clinical complications.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links