Displaying publications 1 - 20 of 34 in total

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  1. Resistance of Pseudomonas pseudomallei to normal human serum bactericidal action
    Ismail G, Razak N, Mohamed R, Embi N, Omar O
    Microbiol. Immunol., 1988;32(7):645-52.
    PMID: 3193910
    The effect of human normal serum (HNS) on Pseudomonas pseudomallei was determined. It is apparent from our data that the organism is resistant to the normal serum bactericidal mechanism. Ancillary experiments to confirm this serum-resistant property of P. pseudomallei were done by examining the effects of growth phase conditions of the bacteria (i.e., logarithmic and stationary phases) and different buffered systems used as diluent in our bactericidal assay. Results obtained showed similar degree of resistance to serum bactericidal killing by 5 strains of the organisms tested. The possible survival advantage of serum-resistance property to P. pseudomallei as bacterial pathogens known to invade the blood stream is discussed.
  2. Inhibition of macromolecular synthesis in cultured macrophages by Pseudomonas pseudomallei exotoxin
    Mohamed R, Nathan S, Embi N, Razak N, Ismail G
    Microbiol. Immunol., 1989;33(10):811-20.
    PMID: 2615673
    Pseudomonas pseudomallei exotoxin was found to be a potent inhibitor of protein and DNA synthesis in cultured macrophages. Inhibition of DNA synthesis occurred at toxin concentrations as low as 1-2 micrograms/ml and inhibition of 3H-thymidine uptake was almost complete at concentrations of 8 micrograms/ml or more. A close correlation between cell damage and inhibition by DNA synthesis was observed. For protein synthesis, inhibition was obtained at much lower doses (0.06-2.0 micrograms/ml) of the toxin. At similar toxin concentrations, DNA synthesis was marginally affected. Further, it was shown that protein synthesis inhibition occurred almost immediately after incubation, reaching its maximal inhibitory effect of 70% after 6 hr. DNA synthesis, however, was minimally affected by a similar toxin concentration even after 10 hr of incubation. The inhibition of macromolecular synthesis in macrophages by P. pseudomallei exotoxin may be relevant to its modulatory effect on the host defense mechanism.
  3. Thermokinetic comparison of trypan blue decolorization by free laccase and fungal biomass
    Razak NN, Annuar MS
    Appl Biochem Biotechnol, 2014 Mar;172(6):2932-44.
    PMID: 24464534 DOI: 10.1007/s12010-014-0731-7
    Free laccase and fungal biomass from white-rot fungi were compared in the thermokinetics study of the laccase-catalyzed decolorization of an azo dye, i.e., Trypan Blue. The decolorization in both systems followed a first-order kinetics. The apparent first-order rate constant, k1', value increases with temperature. Apparent activation energy of decolorization was similar for both systems at ∼ 22 kJ mol(-1), while energy for laccase inactivation was 18 kJ mol(-1). Although both systems were endothermic, fungal biomass showed higher enthalpy, entropy, and Gibbs free energy changes for the decolorization compared to free laccase. On the other hand, free laccase showed reaction spontaneity over a wider range of temperature (ΔT = 40 K) as opposed to fungal biomass (ΔT = 15 K). Comparison of entropy change (ΔS) values indicated metabolism of the dye by the biomass.
  4. Predictors of parenting stress in mothers of children with spina bifida
    Kanaheswari Y, Razak NN, Chandran V, Ong LC
    Spinal Cord, 2011 Mar;49(3):376-80.
    PMID: 20838404 DOI: 10.1038/sc.2010.125
    Prospective cross-sectional multidimensional study using clinical assessment and standard measures.
  5. Fulltext 1-[(Bromo-meth-yl)(phen-yl)meth-ylene]-2-(2,4-dinitro-phen-yl)hydrazine
    Salhin A, Abdul Razak N, Rahman IA
    Acta Crystallogr Sect E Struct Rep Online, 2009;65(Pt 6):o1221-2.
    PMID: 21583090 DOI: 10.1107/S1600536809016225
    The title compound, C(14)H(11)BrN(4)O(4), comprises two crystallographically independent mol-ecules (A and B) in the asymmetric unit. In mol-ecule B, intra-molecular bifurcated N-H⋯O and N-H⋯Br hydrogen bonds and in mol-ecule A, an intra-molecular N-H⋯O hydrogen bond generate S(6) ring motifs. The dihedral angle between the phenyl and benzene rings is 5.44 (6) in mol-ecule A and 7.63 (6)° in mol-ecule B. The ortho- and meta-nitro substituents make dihedral angles of 6.67 (15) and 2.26 (15)° to the attached benzene ring in mol-ecule A and 6.37 (17) and 5.81 (16)° in mol-ecule B. The Br atom in mol-ecule B is disordered over two positions with a refined site-occupancy ratio of 0.61 (3):0.39 (3). Inter-esting features of the crystal structure are the short Br⋯N [3.257 (3)-3.294 (4) Å], Br⋯O [3.279 (3)-3.307 (4) Å] and O⋯O [2.9319 (16)-2.9995 (16) Å] contacts, which are shorter than the sum of the van der Waals radii of these atoms. The crystal structure is further stabilized by inter-molecular C-H⋯O and π-π inter-actions [centroid-centroid distances = 3.6643 (8)-3.8514 (8) Å].
  6. Photoluminescence and thermoluminescence properties of Li2 O-Na2 O-B2 O3 glass
    Razak NA, Hashim S, Mhareb MH, Tamchek N
    Luminescence, 2016 May;31(3):754-9.
    PMID: 26333749 DOI: 10.1002/bio.3020
    Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2 O: 20 Li2 O: (70-x) B2 O3 : xNd2 O3 , where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4) G7/2 → (4) I9/2 , [(4) G7/2 → (4) I11/2 , (4) G5/2 → (4) I9/2 ] and [(4) G7/2 → (4) I13/2 , (4) G5/2 → (4) I11/2 ], respectively. The TL glow curve exhibits a prominent peak (Tm ) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2 O3 . We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Zeff , is 7.55 which is nearly tissue equivalent (Zeff = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. Copyright © 2015 John Wiley & Sons, Ltd.
  7. Quality of Kelantan drinking water and knowledge, attitude and practice among the population of Pasir Mas, Malaysia
    Ab Razak NH, Praveena SM, Aris AZ, Hashim Z
    Public Health, 2016 Feb;131:103-11.
    PMID: 26715317 DOI: 10.1016/j.puhe.2015.11.006
    Information about the quality of drinking water, together with analysis of knowledge, attitude and practice (KAP) analysis and health risk assessment (HRA) remain limited. The aims of this study were: (1) to ascertain the level of KAP regarding heavy metal contamination of drinking water in Pasir Mas; (2) to determine the concentration of heavy metals (Al, Cr, Cu, Fe, Ni, Pb, Zn and Cd) in drinking water in Pasir Mas; and (3) to estimate the health risks (non-carcinogenic and carcinogenic) caused by heavy metal exposure through drinking water using hazard quotient and lifetime cancer risk.
  8. Transtibial prosthesis suspension systems: systematic review of literature
    Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Razak NA
    Clin Biomech (Bristol, Avon), 2014 Jan;29(1):87-97.
    PMID: 24315710 DOI: 10.1016/j.clinbiomech.2013.10.013
    Today a number of prosthetic suspension systems are available for transtibial amputees. Consideration of an appropriate suspension system can ensure that amputee's functional needs are satisfied. The higher the insight to suspension systems, the easier would be the selection for prosthetists. This review attempted to find scientific evidence pertaining to various transtibial suspension systems to provide selection criteria for clinicians.
  9. Kinematic comparison of the wrist movements that are possible with a biomechatronics wrist prosthesis and a body-powered prosthesis: a preliminary study
    Abd Razak NA, Abu Osman NA, Wan Abas WA
    Disabil Rehabil Assist Technol, 2013 May;8(3):255-60.
    PMID: 22830946 DOI: 10.3109/17483107.2012.704654
    This study examined the kinematic differences between a body-powered prosthesis and a biomechatronics prosthesis as a transradial amputee performed activities that involve flexion/extension and supination/pronation of the wrist.
  10. Fulltext Bach adsorption study for the extraction of silver ions by hydrazone compounds from aqueous solution
    Mohamad Ali AS, Abdul Razak N, Ab Rahman I
    ScientificWorldJournal, 2012;2012:351967.
    PMID: 22629138 DOI: 10.1100/2012/351967
    Sorbent materials based on a hydrazone Schiff base compound, C(14)H(11)BrN(4)O(4), were prepared either by immobilizing the ligand into sol-gel (SG1) or bonding to silica (SG2). The sorbent materials were characterized by FT-IR, EDX, SEM, TEM, and TGA. The sorption characteristics of a matrix of eight transition metal ions (Ag(+), Cu(2+), Co(2+), Ni(2+), Fe(3+), Pb(2+), Zn(2+), and Mn(2+)) using batch method were studied. Several key parameters that affected the extraction efficiency such as pH, contact time, metal ions concentration, and gel size (for SGl) were investigated and optimized. Under the optimized conditions, the physically immobilized hydrazone sorbent (SG1) exhibits highest selectivity towards Ag(+) ions, while the chemically bonded hydrazone sorbent (SG2) exhibits high extraction for all metal ions tested. However, for practical applications such as the removal and preconcentration of Ag(+), the physically immobilized sorbent (SG1) is preferred.
  11. An in vivo study of a locally-manufactured hydroxyapatite-based material as bone replacement material
    Abdul Razak NH, Al-Salihi KA, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:119-20.
    PMID: 15468847
    Defects were created in the mandible of a rabbit model whereby the right side was implanted with hydroxyapatite (HA) while the left side was left empty to act as control. Both the implant and control sites were evaluated clinically and histologically at 4,12,20,22 weeks. Decalcified sections were studied under confocal laser scanning microscope. No reactive cells were evident microscopically in all sections. There was bone ingrowth as early as 4 weeks when viewed by the topographic method. Enhancement of osteoconduction was evident by the presence of abundant capillaries, perivascular tissue and osteoprogenitor cells of the host. At 22 weeks, the implanted defect showed mature bone formation filling almost the whole field. This study demonstrated that the dense HA exhibits excellent biocompatibility as noted by the complete absence of reactive cells. It also promotes osteoconduction.
  12. Fulltext Video Game-Based Rehabilitation Approach for Individuals Who Have Undergone Upper Limb Amputation: Case-Control Study
    Hashim NA, Abd Razak NA, Gholizadeh H, Abu Osman NA
    JMIR Serious Games, 2021 Feb 04;9(1):e17017.
    PMID: 33538698 DOI: 10.2196/17017
    BACKGROUND: Brain plasticity is an important factor in prosthesis usage. This plasticity helps with brain adaptation to learn new movement and coordination patterns needed to control a prosthetic hand. It can be achieved through repetitive muscle training that is usually very exhausting and often results in considerable reduction in patient motivation. Previous studies have shown that a playful concept in rehabilitation can increase patient engagement and perseverance.

    OBJECTIVE: This study investigated whether the inclusion of video games in the upper limb amputee rehabilitation protocol could have a beneficial impact for muscle preparation, coordination, and patient motivation among individuals who have undergone transradial upper limb amputation.

    METHODS: Ten participants, including five amputee participants and five able-bodied participants, were enrolled in 10 1-hour sessions within a 4-week rehabilitation program. In order to investigate the effects of the rehabilitation protocol used in this study, virtual reality box and block tests and electromyography (EMG) assessments were performed. Maximum voluntary contraction was measured before, immediately after, and 2 days after interacting with four different EMG-controlled video games. Participant motivation was assessed with the Intrinsic Motivation Inventory (IMI) questionnaire and user evaluation survey.

    RESULTS: Survey analysis showed that muscle strength and coordination increased at the end of training for all the participants. The results of Pearson correlation analysis indicated that there was a significant positive association between the training period and the box and block test score (r8=0.95, P

  13. A single centre experience of metabolic syndrome and endometrial carcinoma: 5 years review
    Shafiee MN, Razak N, Ahmad MF, Abd Aziz N, Adeeb N
    J Obstet Gynaecol, 2021 Feb;41(2):285-289.
    PMID: 33258710 DOI: 10.1080/01443615.2020.1819210
    Endometrial cancer (EC) has been found to have a strong association with overweight and obesity. The aim of this study was to evaluate the link between metabolic syndrome and EC among patients. A total of 119 patients with histologically confirmed EC were recruited. About 102 cases of endometrioid carcinoma (Type I) and serous (n = 7), clear cell (n = 3) and carcinosarcoma (n = 7) were the Type II. Metabolic syndrome was significantly associated with increased risk of Type I EC (OR = 3.43, 95% CI = 1.12-10.46, p  .05). Metabolic syndrome was positively associated with an increased risk of Type I EC with obesity being the most influential risk factor.Impact statementWhat already known on this subject? Endometrial cancer (EC) is one of the most prevalent cancers worldwide and have a strong association with overweight and obesity of at least 40%, but there is conflicting evidence of an association of EC with metabolic syndrome (MS).What result of this study add? This study evaluated the link between EC and MS, such as high blood pressure, BMI, fasting blood sugar, triglyceride, Hyper Density Lipoprotein (HDL).What implications are of these findings for clinical practice & further research? Type I EC had and association with MS with obesity is the most potent risk factor. As the prevalence of metabolic syndrome is alarmingly high among adult Malaysians, the incidence of EC is projected to increase in the coming years. Proactive preventative measures and intervention essential for reducing the incidence of endometrial cancers. Future research to clarify the association between metabolic syndrome and endometrial cancer survival and to investigate other lifestyle factors that may affect the prognosis is needed.
  14. Fulltext Discrepancy in blood pressure between the left and right arms - importance of clinical diagnosis and role of radiological imaging
    Kuan PX, Tan PW, Jobli AT, Abd Razak N
    Med J Malaysia, 2016 Aug;71(4):206-208.
    PMID: 27770122 MyJurnal
    Differences in systolic blood pressure reading between arms are common but could signal trouble if the discrepancy is significant. Early detection of aortic dissection could invariably determine patient's survivability. Hence, a high index of suspicion with prompt diagnostic imaging is vital for accurate diagnosis.
  15. A retrospective analysis of the relationship between facial injury and mild traumatic brain injury
    Abdul Razak N, Nordin R, Abd Rahman N, Ramli R
    Dent Traumatol, 2017 Oct;33(5):400-405.
    PMID: 28649703 DOI: 10.1111/edt.12355
    BACKGROUND/AIMS: The association between facial injury characteristics and mild traumatic brain injury (mTBI) is unclear. The aim of this study was to determine the association between facial injury characteristics and mTBI.

    METHODS: A retrospective review utilizing patients' medical records at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Kuala Lumpur, Malaysia, was performed. Records of subjects with a history of facial trauma from 1 April 2012 to 31 December 2012 were selected. Various levels and surgical speciality records were reviewed to ascertain the diagnoses of facial injuries and mTBI.

    RESULTS: A total of 348 medical records with the diagnosis of facial injuries were included. The prevalence of mTBI among these patients was 41.4% (95% CI 36.2-46.6). The majority of the patients with mTBI were in the age group of 18-25 years old. Patients with or without facial lacerations that were located on the lower face had a significant association with mTBI, P=.001, compared to other types of soft tissue injury. In addition, a statistically significant association was observed between facial fractures occurring to the middle face and mTBI, P=.018. Pearson chi-square test also showed statistically significant association between the severity of facial injuries and mTBI, P=.018.

    CONCLUSIONS: Mild traumatic brain injury should be suspected in patients with facial injuries and particularly those with lower face lacerations, midface fractures, moderate to severe facial injury and presence of multiple injuries.

  16. The Invasive Plant Impatiens glandulifera Manipulates Microbial Associates of Competing Native Species
    Ab Razak N, Gange AC, Sutton BC, Mansor A
    Plants (Basel), 2023 Apr 04;12(7).
    PMID: 37050178 DOI: 10.3390/plants12071552
    Impatiens glandulifera or Himalayan balsam is one of the most invasive weeds across Europe and can seriously reduce native plant diversity. It often forms continuous monocultures along river banks, but the mechanisms of this arrested succession are largely unknown. Here, we investigated the effect of arbuscular mycorrhizal (AM) fungi on balsam competitive ability with two native plant species, Plantago lanceolata and Holcus lanatus. We also studied how competition with Impatiens affects colonisation by foliar endophytes and mycorrhizas of two other co-occurring native species, Urtica dioica and Cirsium arvense. Mycorrhizal colonisation reduced balsam growth when the plants were grown singly, but appeared to have little effect when balsam experienced intra- or interspecific competition. Competition with balsam together with the addition of mycorrhizas had no effect on P. lanceolata biomass, suggesting that the fungi were beneficial to the latter, enabling it to compete effectively with balsam. However, this was not so with H. lanatus. Meanwhile, competition with Impatiens reduced endophyte numbers and mycorrhizal colonisation in U. dioica and C. arvense, leading to enhanced susceptibility of these plants to insect attack. Himalayan balsam is known to degrade soil fungal populations and can also reduce foliar beneficial fungi in neighbouring plants. This allows the plant to compete effectively with itself and other native species, thereby leading to the continuous monocultures.
  17. Satisfaction and problems experienced with wrist movements: comparison between a common body-powered prosthesis and a new biomechatronics prosthesis
    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.
  18. Fulltext Turbulence Model Selection for Low Reynolds Number Flows
    Aftab SM, Mohd Rafie AS, Razak NA, Ahmad KA
    PLoS One, 2016;11(4):e0153755.
    PMID: 27104354 DOI: 10.1371/journal.pone.0153755
    One of the major flow phenomena associated with low Reynolds number flow is the formation of separation bubbles on an airfoil's surface. NACA4415 airfoil is commonly used in wind turbines and UAV applications. The stall characteristics are gradual compared to thin airfoils. The primary criterion set for this work is the capture of laminar separation bubble. Flow is simulated for a Reynolds number of 120,000. The numerical analysis carried out shows the advantages and disadvantages of a few turbulence models. The turbulence models tested were: one equation Spallart Allmars (S-A), two equation SST K-ω, three equation Intermittency (γ) SST, k-kl-ω and finally, the four equation transition γ-Reθ SST. However, the variation in flow physics differs between these turbulence models. Procedure to establish the accuracy of the simulation, in accord with previous experimental results, has been discussed in detail.
  19. Comparative study of the circumferential and volumetric analysis between conventional casting and three-dimensional scanning methods for transtibial socket: A preliminary study
    Mehmood W, Abd Razak NA, Lau MS, Chung TY, Gholizadeh H, Abu Osman NA
    Proc Inst Mech Eng H, 2019 Feb;233(2):181-192.
    PMID: 30518308 DOI: 10.1177/0954411918816124
    Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve using plaster of Paris bandages for casting. This will include modifications through hand, scanning and digital imaging of software. The aim of this study is to determine the circumferential profiles and conduct a volumetric analysis of a conventional socket that has fabrication using biosculptor technology. In doing this, a male transtibial amputee, age 28 years old with stable health condition was studied, where circumferential measurements were taken at intervals of 1 cm from the distal end of the residual limb to the medial tibial plateau level. Furthermore, the interior volume of both sockets and residuum were determined directly using water displacement method. A comparative value for the calculation of volume was also carried out using engineering mathematical equations. From these measurements, a total surface bearing transtibial sockets was fabricated to compare the changes of circumferential values of both sockets. The finding shows a percentage of the difference between the volume of the residual limb and conventional sockets to be 6.09%, whereas the biosculptor fabrication socket was 7.84% using the water displacement method. A comparison of circumferential profiles and volumetric analysis findings on the contrary showed that socket fabricated using the biosculptor technology is interchangeable with the conventional socket with more advantages, where biosculptor technology produces cheaper sockets and faster process with digital function in the procedure, unlike the conventional manual technique.
  20. Fulltext Detection of α-thalassaemia in neonates on cord blood and dried blood spot samples by capillary electrophoresis
    Alauddin H, Langa M, Mohd Yusoff M, Raja Sabudin RZA, Ithnin A, Abdul Razak NF, et al.
    Malays J Pathol, 2017 Apr;39(1):17-23.
    PMID: 28413201 MyJurnal
    INTRODUCTION: Haemoglobin Bart's (Hb Bart's) level is associated with α-thalassaemia traits in neonates, enabling early diagnosis of α-thalassaemia. The study aimed to detect and quantify the Hb Bart's using Cord Blood (CB) and CE Neonat Fast Hb (NF) progammes on fresh and dried blood spot (DBS) specimen respectively by capillary electrophoresis (CE).

    METHODS: Capillarys Hemoglobin (E) Kit (for CB) and Capillarys Neonat Hb Kit (for NF) were used to detect and quantify Hb Bart's by CE in fresh cord blood and dried blood spot (DBS) specimens respectively. High performance liquid chromatography (HPLC) using the β-Thal Short Programme was also performed concurrently with CE analysis. Confirmation was obtained by multiplex ARMS Gap PCR.

    RESULTS: This study was performed on 600 neonates. 32/600 (5.3%) samples showed presence of Hb Bart's peak using the NF programme while 33/600 (5.5%) were positive with CB programme and HPLC methods. The range of Hb Bart's using NF programme and CB programme were (0.5-4.1%) and (0.5-7.1%), respectively. Molecular analysis confirmed all positive samples possessed α-thalassaemia genetic mutations, with 23/33 cases being αα/--SEA, four -α3.7/-α3.7, two αα/-α3.7 and three αα/ααCS. Fifty Hb Bart's negative samples were randomly tested for α-genotypes, three were also found to be positive for α-globin gene mutations. Thus, resulting in sensitivity of 91.7% and 88.9% and specificity of 100% for the Capillarys Cord Blood programme and Capillarys Neonat Fast programme respectively.

    CONCLUSION: Both CE programmes using fresh or dried cord blood were useful as a screening tool for α-thalassaemia in newborns. All methods show the same specificity (100%) with variable, but acceptable sensitivities in the detection of Hb Bart.
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