Displaying publications 1 - 20 of 53 in total

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  1. Almayahi BA, Tajuddin AA, Jaafar MS
    J Environ Radioact, 2014 Mar;129:140-7.
    PMID: 24462923 DOI: 10.1016/j.jenvrad.2014.01.001
    In this study, the radiobiological analysis of natural alpha emitters in extracted human teeth and animal bones from Malaysia was estimated. The microdistributions of alpha particles in tooth and bone samples were measured using CR-39 alpha-particle track detectors. The lowest and highest alpha emission rates in teeth in the Kedah and Perak states were 0.0080 ± 0.0005 mBq cm(-2) and 0.061 ± 0.008 mBq cm(-2), whereas those of bones in the Perlis and Kedah states were 0.0140 ± 0.0001 mBq cm(-2) and 0.7700 ± 0.0282 mBq cm(-2), respectively. The average alpha emission rate in male teeth was 0.0209 ± 0.0008 mBq cm(-2), whereas that of female teeth was 0.0199 ± 0.0010 mBq cm(-2). The alpha emission rate in teeth is higher in smokers (0.0228 ± 0.0008 mBq cm(-2)) than in non-smokers (0.0179 ± 0.0008 mBq cm(-2)). Such difference was found statistically significant (p < 0.01).
  2. Almayahi BA, Tajuddin AA, Jaafar MS
    Appl Radiat Isot, 2012 Nov;70(11):2652-60.
    PMID: 22982603 DOI: 10.1016/j.apradiso.2012.07.021
    The radioactivity quantity and quality were determined in soil and water samples in Northern Malaysian Peninsula (NMP) using HPGe spectroscopy and GR-135 spectrometer. The (226)Ra, (232)Th and (40)K concentrations in soil samples are 57±2, 68±4 and 427±17 Bq kg(-1), respectively, whereas in water samples were found to be 2.86±0.79, 3.78±1.73 and 152±12 Bq l(-1), respectively. These concentrations are within those reported from literature in other countries in the world. The radiological hazard indices of the samples were also calculated. The mean values obtained from soil samples are 186 Bq kg(-1), 88 nGy h(-1), 108 μSv y(-1), 0.50 and 0.65 for Radium Equivalent Activity (Ra(eq)), Absorbed Dose Rates (D(R)), Annual Effective Dose Rates (ED), External Hazard Index (H(ex)) and Internal Hazard Index (H(in)) respectively, whereas, for water samples were found to be 20, 10, 13, 0.05 and 0.06, respectively. All the health hazard indices are well below their recommended limits, except in two soil sampling sites which were found to be (*)025 (1.1 H(ex)) and (*)026 (1.1 H(ex), 1.6 H(in)). The calculated and the measured gamma dose rates had a good correlation coefficient, R=0.88. Moreover, the average value radon is 20 (in the range of 7-64) Bq m(-3), a positive correlation (R=0.81) was observed between the (222)Rn and (226)Ra concentrations in samples measured by the SNC continuous radon monitor (model 1029, Sun Nuclear Corporation) and HPGe detector, respectively. Some soils in this study with H(in) and H(ex)<1 are suitable for use in agriculture and as building materials. Also, in this study H(in) and H(ex)<1 for water samples, therefore, water after processing and filtration is safe and suitable for use in household and industrial purposes.
  3. Al-Khaza'leh KA, Omar K, Jaafar MS
    J Biol Phys, 2011 Jan;37(1):153-61.
    PMID: 22210969 DOI: 10.1007/s10867-010-9206-4
    The effects of pH value and presence of serum in an incubation medium on photosensitizer drug cellular uptake in MCF7 cancer cells have been investigated. The results showed that the presence of serum in an incubation medium reduced the drug cellular uptake at all pH values. It has been found that decreasing on pH values of the incubation medium increased the cellular uptake of the drug, demonstrating selective uptake of the sensitizer. The HepG2 liver cancer cells exhibited more drug cellular uptake than CCD-18CO normal colon cells, which assessed the selectivity uptake of photosensitizer on cancerous cells. The concentration of photosensitizer measured in 10(6) cells showed a good correlation to the incubation time. Fluorescence and absorption spectroscopy been have used to examine the cells.
  4. Muhammad BG, Jaafar MS, Akpa TC
    Radiat Prot Dosimetry, 2010 Sep;141(2):127-33.
    PMID: 20562117 DOI: 10.1093/rpd/ncq162
    Stratified sampling procedure was employed to collect a total of 40 samples; 2 from each stratum, measuring an approximate dimension of 3.25 km(2) of the actual sample site. Appropriate volumes were then evaporated and transferred into clean stainless steel planchets (ISO 9696 and ISO 9697). An eight channel gas-flow proportional counting system connected to a microprocessor loaded with a spreadsheet programme (Quarttro-Pro) and graphic programme (Multiplan) initially calibrated for efficiency was employed to count the background and the prepared samples. A mean efficiency of 33.44 and 41.24 % for the respective alpha and beta sources was obtained. A low background activity was also observed with a mean of 0.165 Bq for alpha and 1.119 Bq for beta. The gross alpha and beta activity concentrations in the water were found to range from 80 +/- 0.05 to 2300 +/- 0.41 Bq m(-3) and 120 +/- 0.08 to 4970 +/- 0.78 Bq m(-3), respectively. This clearly indicate areas of elevated alpha and beta activity concentrations of 37.5 and 47.5 %, respectively when compared with the International Commission for Radiological Protection (1991) maximum acceptable values of 500 Bq m(-3) for alpha and 1000 Bq m(-3) for beta.
  5. Hashim OH, Gendeh GS, Jaafar MI
    Biochem. Int., 1992 Jun;27(1):139-43.
    PMID: 1627170
    The effect of extracts of champedak (Artocarpus integer) seed lectin on the proliferation of normal human lymphocyte was investigated. The IgA1 binding lectin was demonstrated to stimulate the proliferation of human peripheral blood mononuclear cells. Action of the lectin on enriched T and B cell populations demonstrated T lymphocyte specificity. The lectin was not mitogenic to B lymphocytes. Optimal stimulation of proliferative response was achieved when cells were subjected to 5 days exposure to the crude lectin at 20 micrograms/ml.
  6. Hashim OH, Gendeh GS, Jaafar MI
    Biochem. Mol. Biol. Int., 1993 Jan;29(1):69-76.
    PMID: 8490570
    Purified lectins from seeds of six distinct clones of Artocarpus integer (lectin C) were shown to be structurally and functionally similar. All lectins comprised of two types of non-covalently-linked subunits with apparent M(r) of 13,300 and 16,000. The lectins appeared to interact with several human serum proteins, with the predominance of the IgA1 and C1 inhibitor molecules. Interaction was not detected with IgA2, IgD, IgG and IgM. The lectin Cs were also shown to precipitate monkey, sheep, rabbit, cat, hamster, rat and guinea-pig serum. Due to their uniform properties, lectin C may provide better alternative to the Artocarpus heterophyllus lectin, jacalin, for use in future investigations.
  7. Tan NH, Saifuddin MN, Jaafar MI
    Toxicon, 1990;28(11):1355-9.
    PMID: 2128424
    Hannahtoxin, the major hemorrhagin purified from king cobra (Ophiophagus hannah) venom, elicits hemorrhages in rabbits but not in mice. Two antisera against hannahtoxin were prepared: one raised against purified hannahtoxin, while the other was raised against glutaraldehyde cross-linked and detoxified hannahtoxin. The antisera were refined by pepsin digestion and ammonium sulfate precipitation. They are of approximately equal potency in their ability to neutralize the hemorrhagic activity of king cobra venom in rabbits. The antisera did not form a precipitin line with venom of snakes of the Viperidae family nor neutralize hemorrhages elicited in mice by any of these venoms. However, when the hemorrhagic activity was assayed in rabbits, both antisera were able to abolish the hemorrhages elicited by all of the venoms tested. These results suggest that hannahtoxin displays few epitopes in common with hemorrhagins of viperid venoms, except those involved in the neutralization of hemorrhagic activity in rabbits. The epitopes of viperid venom hemorrhagins involved in the neutralization reaction in rabbits are different from those in mice.
  8. Tan NH, Yeo KH, Jaafar MI
    Toxicon, 1992 Dec;30(12):1609-20.
    PMID: 1488770
    The specificity and sensitivity of an indirect and two (an 'ordinary' and a 'rapid') double sandwich enzyme-linked immunosorbent assay (ELISA) procedures for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom were examined. The three assays were equally sensitive and the accuracy of the assays was not substantially affected by individual variation in the venom composition. The specificity of the assays was examined against 26 venoms from snakes of the families Viperidae and Elapidae. While the double sandwich ELISA procedures were sufficiently specific to be used in the clinical immunodiagnosis of C. rhodostoma bite in Malaysia, the indirect ELISA procedure exhibited extensive cross-reactivity with other Malaysian pit viper venoms. Attempts were made to improve the specificity of the indirect ELISA procedure for the quantitation of C. rhodostoma venom. A 'low ELISA cross-reactivity' venom fraction (termed VF52) was isolated from C. rhodostoma venom by repeated Sephadex G-100 gel filtration chromatography. The indirect ELISA procedure using antibodies to VF52 as immunoreagent showed an improvement in specificity. The use of the indirect ELISA procedure for the detection of C. rhodostoma antibodies was also examined and the results show that the assay was sufficiently specific to be used for retrospective diagnosis of C. rhodostoma bite in Malaysia, in particular when VF52 was used as the coating antigen.
  9. Tan NH, Lim KK, Jaafar MI
    Toxicon, 1993 Jul;31(7):865-72.
    PMID: 8212031
    The antigenic cross-reactivity of four Ophiophagus hannah (king cobra) venom components, the neurotoxin (OH-NTX), phospholipase A2 (OH-PLA2), hemorrhagin (OH-HMG) and L-amino acid oxidase (OH-LAAO) were examined by indirect and double sandwich ELISAs. The indirect ELISAs for OH-NTX, OH-PLA2 and OH-HMG were very specific when assayed against the various heterologous snake venoms and O. hannah venom components, at 25 ng/ml antigen level. At higher antigen concentrations (100-400 ng/ml), there were moderate to strong indirect ELISA cross-reactions between anti-O. hannah neurotoxin and venoms from various species of cobra as well as two short neurotoxins. However, anti-O. hannah hemorrhagin did not cross-react with any of the venoms tested, even at these high antigen concentrations, indicating that O. hannah hemorrhagin is antigenically very different from other venom hemorrhagins. Examination of the indirect ELISA cross-reactions between anti-O. hannah PLA2 and several elapid PLA2 enzymes suggests that the elapid PLA2 antigenic class has more than two subgroups. The antibodies to O. hannah L-amino acid oxidase, however, yielded indirect ELISA cross-reactions with many venoms as well as with OH-NTX, OH-PLA2 and OH-HMG, indicating that OH-LAAO shares common epitopes even with unrelated proteins. The double sandwich ELISAs for the four anti-O. hannah venom components, on the other hand, generally exhibited a higher degree of selectivity than the indirect ELISA procedure.
  10. Salman A, Jaafar M, Mohamad D, Malik S
    Environ Sci Pollut Res Int, 2021 Aug;28(31):42945-42958.
    PMID: 33834332 DOI: 10.1007/s11356-021-13609-y
    Located in one of the famous natural and cultural tourist destinations of northern Malaysia, Penang Hill serves as an ideal destination for both local and international tourists. The objective of this study was to understand and explore key stakeholders perspectives to enhance management for the aim of conservation, economic development, and recreation in Penang Hill. Data was collected from three key stakeholders of Penang Hill using semi-structured in-depth interviews. Stakeholders showed robust interests in environmental protection, cultural conservation, economic activities, awareness, and empowerment. This paper concludes by stating that Penang Hill is under strong management, and stakeholders are continuously engaged in the destination. The management authority collaborates with the key stakeholders of Penang Hill and incorporates their interests and viewpoint to ensure the ecotourism process goes smoothly and Penang Hill becomes one of the top ecotourism destinations.
  11. Jaafar MH, Mahadeva S, Subramanian P, Tan MP
    J Nutr Health Aging, 2017;21(4):473-479.
    PMID: 28346575 DOI: 10.1007/s12603-016-0774-2
    OBJECTIVE: To explore the perceptions of healthcare professionals' (HCPs) in a South East Asian nation towards percutaneous endoscopic gastrostomy (PEG) feeding.

    DESIGN: Semi-structured, qualitative interviews.

    SETTINGS: A teaching hospital in Kuala Lumpur, Malaysia.

    PARTICIPANTS: A total of 17 healthcare professionals aged 23-43 years, 82% women.

    RESULTS: Thematic analysis revealed five themes that represent HCPs' perceptions in relation to the usage of PEG feeding: 1) knowledge of HCPs, 2) communication, 3) understanding among patients, and 4) financial and affordability.

    CONCLUSION: The rationale for reluctance towards PEG feeding observed in this regions was explained by lack of education, knowledge, communication, team work, and financial support. Future studies should assess the effects of educational programmes among HCPs and changes in policies to promote affordability on the utilization of PEG feeding in this region.

  12. Jaafar MH, Mahadeva S, Morgan K, Tan MP
    J Nutr Health Aging, 2015 Feb;19(2):190-7.
    PMID: 25651445 DOI: 10.1007/s12603-014-0527-z
    OBJECTIVE: The objective of this systematic review was to evaluate existing studies on the effectiveness of percutaneous endoscopic gastrostomy (PEG) feeding compared to nasogastric (NG) feeding for patients with non-stroke related dysphagia.

    METHODS: We searched Ovid MEDLINE, EMBASE, the Cochrane Library, Web of Science and PubMed databases through to December 2013 using the terms "percutaneous endoscopic gastrostomy", "gastrostomy", "PEG", "nasogastric", "nasogastric tube", "nasogastric feeding" and "intubation". We included randomized controlled trials (RCTs) and non-RCTs which compared PEG with NG feeding in individuals with non-stroke dysphagia.

    RESULTS: 9 studies involving 847 participants were included in the final analysis, including two randomized trials. Pooled analysis indicated no significant difference in the risk of pneumonia [relative risk (RR) = 1.18, 95% confidence interval (CI) = 0.87-1.60] and overall complications [relative risk (RR) = 0.80, 95% confidence interval (CI) = 0.63-1.02] between PEG and NG feeding. A meta-analysis was not possible for mortality and nutritional outcomes, but three studies suggested improved mortality outcomes with PEG feeding while two out of three studies reported PEG feeding to be better from a nutritional perspective.

    CONCLUSIONS: Firm conclusions could not be derived on whether PEG feeding is beneficial over NG feeding in older persons with non-stroke dysphagia, as previously published literature were unclear or had a high risk of bias. A well-designed and adequately powered RCT, which includes carer strain and quality of life as outcome measures is therefore urgently needed.

  13. Salman A, Jaafar M, Mohamad D, Khoshkam M
    Environ Dev Sustain, 2022 Jun 27.
    PMID: 35789745 DOI: 10.1007/s10668-022-02488-z
    Ecotourism offers several economic, environmental, and cultural benefits; however, even after all these years, achieving ecotourism sustainability is still complex because of multiple stakeholders with diversified interests and influence. This study focused on the multiple stakeholders' complexity and management for achieving sustainable ecotourism in Penang Hill in Malaysia. Understanding the existence of multiple stakeholders with varying interests and their respective power of influence is critical for a tourism destination to be sustainable. This study aimed to create a multi-stakeholder management framework and understand stakeholder management's mediating role toward ecotourism sustainability in Penang Hill. Data were collected from Penang Hill key stakeholders and analyzed using SmartPLS and fuzzy-set Qualitative Comparative Analysis (fsQCA). The findings revealed that stakeholder management plays a significant mediating role in achieving ecotourism sustainability. Stakeholders' interests and their level of influence should be understood to develop engagement, empowerment, and monitoring strategies for managing stakeholders. Thus, the study contributes by validating the results through symmetric and asymmetric techniques, offering solutions to the emerging issues during the Covid-19 pandemic, and recommending policy changes. Lastly, the study also extends prior literature by displaying the mediating role played by stakeholder management on ecotourism sustainability, comparing indirect and total effects on stakeholder management support for achieving sustainable ecotourism in Penang Hill.
  14. Latif G, Bashar A, Awang Iskandar DNF, Mohammad N, Brahim GB, Alghazo JM
    Med Biol Eng Comput, 2023 Jan;61(1):45-59.
    PMID: 36323980 DOI: 10.1007/s11517-022-02687-w
    Early detection and diagnosis of brain tumors are essential for early intervention and eventually successful treatment plans leading to either a full recovery or an increase in the patient lifespan. However, diagnosis of brain tumors is not an easy task since it requires highly skilled professionals, making this procedure both costly and time-consuming. The diagnosis process relying on MR images gets even harder in the presence of similar objects in terms of their density, size, and shape. No matter how skilled professionals are, their task is still prone to human error. The main aim of this work is to propose a system that can automatically classify and diagnose glioma brain tumors into one of the four tumor types: (1) necrosis, (2) edema, (3) enhancing, and (4) non-enhancing. In this paper, we propose a combined texture discrete wavelet transform (DWT) and statistical features based on the first- and second-order features for the accurate classification and diagnosis of multiclass glioma tumors. Four well-known classifiers, namely, support vector machines (SVM), random forest (RF), multilayer perceptron (MLP), and naïve Bayes (NB), are used for classification. The BraTS 2018 dataset is used for the experiments, and with the combined DWT and statistical features, the RF classifier achieved the highest average accuracy whether for separated modalities or combined modalities. The highest average accuracy of 89.59% and 90.28% for HGG and LGG, respectively, was reported in this paper. It has also been observed that the proposed method outperforms similar existing methods reported in the extant literature.
  15. Muhammad BG, Jaafar MS, Azhar AR, Akpa TC
    Radiat Prot Dosimetry, 2012 Apr;149(3):340-6.
    PMID: 21642647 DOI: 10.1093/rpd/ncr230
    Measurements of (222)Rn activity concentration were carried out in 39 samples collected from the domestic and drinking water sources used in the island and mainland of Penang, northern peninsular, Malaysia. The measured activity concentrations ranged from 7.49 to 26.25 Bq l(-1), 0.49 to 9.72 Bq l(-1) and 0.58 to 2.54 Bq l(-1) in the raw, treated and bottled water samples collected, respectively. This indicated relatively high radon concentrations compared with that from other parts of the world, which still falls below the WHO recommended treatment level of 100 Bq l(-1). From this data, the age-dependent associated committed effective doses due to the ingestion of (222)Rn as a consequence of direct consumption of drinking water were calculated. The committed effective doses from (222)Rn resulting from 1 y's consumption of these water were estimated to range from 0.003 to 0.048, 0.001 to 0.018 and 0.002 to 0.023 mSv y(-1), for age groups 0-1, 2-16 and >16 y, respectively.
  16. Esa K, Azarinah I, Muhammad M, Helmi MA, Jaafar MZ
    Med J Malaysia, 2011 Aug;66(3):182-6.
    PMID: 22111436
    This was a prospective randomized study comparing the ease of insertion, haemodynamic changes, quality of airway seal, oxygenation and ventilation parameters and complications between Laryngeal Tube Suction II (LTS II) with Proseal Laryngeal Mask Airway (PLMA), both are supraglottic airway incorporated with gastric passage. Fifty-four ASA I and II patients were randomly allocated to receive either LTS II or PLMA. Both devices provided a secure airway even under conditions of elevated intra-abdominal pressure up to 17 mmHg. In this study, there were no differences concerning ease of insertion, haemodynamic changes, quality of airway seal, oxygenation and ventilation parameters and complications between LTS II and PLMA.
  17. Aldahoun MA, Jaafar MS, Al-Akhras MH, Bououdina M
    Artif Cells Nanomed Biotechnol, 2017 Jun;45(4):843-853.
    PMID: 27137748 DOI: 10.1080/21691401.2016.1178137
    Curcumin is more soluble in ethanol, dimethylsulfoxide, methanol and acetone than in water. In this study, nanocurcumin combined with 8 mT AC static magnetic field was used to enhance cellular uptake, bioavailability, and ultimate efficiency of curcumin against prostate cancer cell line (PC3), four bacteria strains (two Gram positive: Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 29213 and two Gram negative: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), mammalian cell line (HEK) and human erythrocytes (RBC). The efficiency (E%) between IC50 of nanocurcumin combined with magnetic field (NANOCUR-MF) and control against PC3 was 35.93%, which is three times higher compared to curcumin combined with magnetic field (CUR-MF); i.e., 10.77%. However, their E% against HEK was not significant; 1.4% for NANOCUR-MF and 1.95% for CUR-MF. Moreover, depending in minimum bacterial concentration (MBC), the use of MF leads to a reduction of MBCs for all tested bacteria compared with control. The obtained results established the applicability of (MF) in enhancing cellular uptake for PC3 and tested bacteria strains by increasing the penetration of drug (nanocurcumin and parent curcumin) into cell with fixing mild cytotoxic profile for HEK and RBC.
  18. Hashim OH, Ng CL, Gendeh S, Nik Jaafar MI
    Mol Immunol, 1991 4 1;28(4-5):393-8.
    PMID: 2062319
    The discovery of jacalin, a group of lectins from jackfruit seeds (Artocarpus heterophyllus), has attracted considerable attention due to its numerous interesting immunological properties as well as its usefulness in the isolation of various serum proteins. We have further identified a similar lectin from the seeds of Champedak (Artocarpus integer) which we refer to as lectin-C and performed comparative studies with two types of jacalin isolated from different batches of the Malaysian jackfruit seeds (jacalin-M1 and jacalin-M2). The three purified lectins demonstrated equivalent apparent Mr of about 52,500, each of which comprised of a combination of two types of non-covalently-linked subunits with apparent Mr of approximately 13,300 and 16,000. The lectins demonstrated equal haemagglutinating activity against human erythrocytes of blood groups A, B, AB and O. Our data also demonstrated that lectin-C, jacalin-M1 and jacalin-M2 are similar by selectively precipitating human serum IgA1 and colostral sIgA but not IgA2, IgD, IgG and IgM. When immunoelectrophoresis was performed on normal human sera and reacted with the lectins, single precipitin arcs corresponding to IgA immunoprecipitates were detected with lectin-C and jacalin-MI. Jacalin-M2, however, exhibited two closely associated precipitin arcs. The binding of these lectins with IgA was pronouncedly inhibited in the presence of p-nitrophenyl-beta-D-galactopyranoside, 1-o-methyl-alpha-D-galactopyranoside, D-melibiose, N-acetyl-D-galactosamine and D-galactose. The data therefore provide evidence on the differential specificity of IgA binding lectins isolated from seeds of similar as well as distinct Artocarpus species.
  19. Sarwar A, Khan J, Muhammad L, Mubarak N, Jaafar M
    J Nurs Manag, 2021 Jan 04.
    PMID: 33394539 DOI: 10.1111/jonm.13241
    AIM(S): This paper investigated the impact of organisational dehumanization on nurses' deviant behaviours in the Pakistani health sector directly and indirectly through job stress. The study also examined the moderation role of occupational self-efficacy on the relationship between organisational dehumanization and job stress.

    BACKGROUND: While the attitudinal outcomes of organisational dehumanization have been a focus of research, its behavioural outcomes are a relatively ignored research area.

    METHOD: Data were collected from 295 nurses working in hospitals across Pakistan via self-administered questionnaires with two measurement points to test the direct and indirect effects of organisational dehumanization.

    RESULTS: The hypothesized relationships were tested with SPSS 25 and the Process Macro Model 7. The results showed that organisational dehumanization increased deviant behaviours among nurses directly and indirectly via job stress. Moreover, occupational self-efficacy plays moderation role and weakens the relationship between organisational dehumanization and job stress.

    CONCLUSION: This study contributes to the existing literature by concentrating on predictors that trigger deviant behaviour among nurses. It also assessed the mediating impact of job stress, an essential endeavour for researchers and practitioners.

    IMPLICATIONS FOR NURSING MANAGEMENT: The study outcomes can help the health sector improve their strategies to address organisational dehumanization and deviant behaviour among nurses.

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