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  1. Mohd-Zain Z, Mohd-Nawi SFA, Adnan A, Kumar S
    Malays J Pathol, 2017 Aug;39(2):115-122.
    PMID: 28866692 MyJurnal
    BACKGROUND: HIV-infected patients pose a high risk of contracting skin and soft tissue infections caused by Staphylococcus aureus. Those who are colonized with methicillin-resistant S. aureus (MRSA) that carry Panton-Valentine leukocidin (PVL) are predisposed to severe infections that could lead to necrotic skin infections. However the association of S. aureus specifically methicillin sensitive S. aureus carrying PVL gene in HIV patients has not been widely reported. Here, we study the prevalence and the molecular epidemiology of PVL-producing S. aureus in HIV-infected patients.

    METHODS: Swabs from four body sites of 129 HIV-infected patients were cultured for S. aureus and identified by standard microbiological procedures. The isolates were subjected to antimicrobial susceptibility testing by disk diffusion against penicillin, erythromycin, clindamycin, and cotrimoxazole. PCR was used to detect the PVL gene and genetic relationship between the isolates was determined by using pulse field gel electrophoresis.

    RESULTS: A total of 51 isolates of S. aureus were obtained from 40 (31%) of the patients. The majority (43.1%) of the isolates were obtained from the anterior nares. Thirteen (25.5%) of all the isolates were resistant to more than one category of antibiotics, with one isolate identified as MRSA. Thirty-eight (74.5%) isolates (including the MRSA isolate) carried PVL gene where the majority (44.7%) of these isolates were from the anterior nares. A dendogram revealed that the isolates were genetically diverse with 37 distinct pulsotypes clustered in 11 groups.

    CONCLUSION: S. aureus obtained from multiple sites of the HIV patients were genetically diverse without any clonality observed.

  2. Situ SF, Ding CH, Nawi S, Johar A, Ramli R
    Malays J Pathol, 2017 Apr;39(1):25-31.
    PMID: 28413202 MyJurnal
    BACKGROUND: Chlamydia trachomatis and Neisseria gonorrhoeae are important bacterial pathogens of sexually transmitted infections (STIs) worldwide. This study sought to compare the analytical sensitivity and specificity of conventional methods against a rapid molecular method in detecting STIs caused by these bacteria.

    METHODS: Ninety five first-time male attendees of the Genito-urinary Medicine Clinic in Hospital Kuala Lumpur were included in this cross-sectional study. The detection of C. trachomatis was achieved through direct fluorescence antibody (DFA) staining of urethral swabs and real-time polymerase chain reaction testing (Xpert® CT/NG assay) on urine specimens. N. gonorrhoeae was detected through Gram staining and culture of urethral swabs and Xpert® CT/ NG assay on urine specimens.

    RESULTS: From the Xpert® CT/NG results, 11 (11.6%) attendees had chlamydia, 23 (24.2%) had gonorrhoea and 8 (8.4%) had both STIs. The sensitivity and specificity of DFA in detecting chlamydia compared to Xpert® CT/NG were 5.3% (95% CI: 0-28) and 94.7% (95% CI: 86-98), respectively. For gonorrhoea, the sensitivity and specificity of Gram staining were 90.3% (95% CI: 73-98) and 95.3% (86-99), respectively, whereas the sensitivity and specificity of culture compared to Xpert® CT/NG were 32.2% (95% CI: 17-51) and 100% (95% CI: 93-100), respectively.

    CONCLUSION: Although Gram-stained urethral swab smears are sensitive enough to be retained as a screening tool for gonorrhoea, culture as well as DFA lack sensitivity and are poorly suited to screen for gonorrhoea and chlamydia, respectively. However, owing to their high specificity, conventional detection methods are still suitable as confirmatory tests for gonorrhoea and chlamydia.

  3. Rahimi R, Omar E, Tuan Soh TS, Mohd Nawi SFA, Md Noor S
    Malays J Pathol, 2018 Aug;40(2):169-173.
    PMID: 30173235 MyJurnal
    INTRODUCTION: Leptospirosis is a zoonotic disease caused by spirochaete of the genus Leptospira. Human infection occurs after exposure to water or soil contaminated by urine from an infected animal. Most patients manifest as self-limited systemic illness. However 10% of patients manifest as severe disease associated with high fatality. The disease affects mostly men, cases involving pregnant women are uncommon. We presented a case of leptospirosis in a pregnant woman leading to mortality of both mother and foetus.

    CASE REPORT: A 28-year-old woman at 18 weeks of gestation, had shortness of breath and collapsed. She was brought unconscious to the emergency department and died shortly after arrival. A week prior to this, she had presented to the same hospital with pain on both thighs. Examination of the patient and ultrasound of the foetus revealed normal findings. Post mortem examination revealed hepatosplenomegaly and congested lungs; no jaundice, meningeal inflammation or cardiac abnormalities was evident. Histopathology examination of the lungs revealed pulmonary haemorrhages and oedema. Multiple infarcts were seen in the spleen and the kidneys showed foci of acute tubular necrosis. Laboratory investigations revealed Leptospira IgM antibody and PCR for leptospira were positive. This case illustrates the subtleness of clinical presentation of leptospirosis. The diagnosis was obscure even at post-mortem and was only suspected following histopathological examination, leading to further investigations.

    CONCLUSION: Leptospirosis may have a subtle presentation and a high index of suspicion for this infection is required for early identification of the disease.

  4. Rahimi R, Omar E, Tuan Soh TS, Mohd Nawi SFA, Md Noor S
    Malays J Pathol, 2017 Aug;39(2):167-170.
    PMID: 28866699 MyJurnal
    BACKGROUND: Hand, foot and mouth disease (HFMD) is caused by enteroviruses such as Coxsackie virus A16 (CVA16) and Enterovirus 71 (EV71). The diagnostic hallmarks are oral ulcers and maculo-papular or vesicular rash on the hands and feet. Severe form of this disease can lead to death due to neurological and cardiopulmonary complications. This case report aims to describe a fatal case of HFMD with minimal oral and skin manifestations.
    CASE REPORT: A four-year-old girl was brought to a hospital after suddenly becoming unresponsive at home. She had a history of fever and lethargy for three days prior to her demise. The patient, and f ive other children in her neighbourhood had been diagnosed to have HFMD at a local health clinic; the other children had recovered without complications.
    RESULTS: Autopsy revealed a few punctate, sub-epidermal vesicles measuring 1 to 2 mm on the palm of her right hand and sole of the right foot, visible only with a magnifying glass. Internal examination revealed prominent nodularity at the oro- and hypopharynxes. The lungs were markedly congested and oedematous. Histopathology of the lung showed marked oedema and haemorrhage with mild pneumonic changes. Oedema with increase in macroglia and astrocytic proliferation were seen in the cerebral tissue, but no lymphocytic infiltration was evident. Enterovirus EV71 was detected by polymerase chain reaction in samples from the lung, cerebrospinal fluid and serum. The cause of death was given as HFMD complicated by pneumonia.
    CONCLUSION: Fatal HFMD may have minimal signs. A complete history, careful physical examination and relevant investigations lead to a diagnosis at post mortem examination. Awareness of the subtle signs and rapid deterioration associated with a fatal case of HFMD is a challenge to clinicians who encounter these cases.
  5. Suppiah J, Mohd Zain R, Bahari N, Haji Nawi S, Saat Z
    Hepat Mon, 2014 Dec;14(12):e22565.
    PMID: 25737728 DOI: 10.5812/hepatmon.22565
    The S gene region of the hepatitis B virus (HBV) codes for surface antigen (HBs Ag) and is responsible for classification of HBV strains.
  6. Suppiah J, Mohd Zain R, Haji Nawi S, Bahari N, Saat Z
    Hepat Mon, 2014 Jan;14(1):e13173.
    PMID: 24497877 DOI: 10.5812/hepatmon.13173
    Mutations in the polymerase (P) gene of hepatitis B virus are often associated with drug resistance. The pattern of mutations varies geographically, thus giving rise to genotypes diversity.
  7. Suppiah J, Mohd Zain R, Bahari N, Haji Nawi S, Saat Z
    Hepat Mon, 2015 Oct;15(10):e31490.
    PMID: 26587040 DOI: 10.5812/hepatmon.31490
    Precore stop codon (G1896A) mutation is one of the commonest mutations found in patients with chronic hepatitis B. However, over the years, this mutation was not reported much in Malaysia.
  8. Yasmin S, Khandaker MU, Nawi SNM, Sani SFA, Bradley DA, Islam MA
    Appl Radiat Isot, 2021 Sep;175:109782.
    PMID: 34082304 DOI: 10.1016/j.apradiso.2021.109782
    Among the various types of decorative materials used in Bangladeshi dwellings, the marble/marble stone is one of the most common ones that used largely for enhancing the beauty and/or aristocracy of the dwelling environment. In this study, the most commonly used, six types of marble stones, have been analyzed for retrospective accident dosimetry. With the interest of characterizing several key thermoluminescence properties to examine their potentiality for dosimetry, annealing - irradiation - readout steps have been done chronologically which comprises the analysis of glow curves, relative sensitivity, dose dependence, repeatability and fading. Considering the various TL parameters, marble 'Carrara' imported from Italy present relatively better capability for reconstruction of radiation dose in the dose range of 10-50 Gy. From fading result, it is clear that for reconstruction of absorbed dose up to four weeks of post exposure, the marble 'Carrara' is found to be the most reliable media among the studied marble types. The Zeff values for the various marble samples are found to be in the range of 13.65-19.12, comparing favorably in replace of TLD-200 (Zeff = 16.3) which can be used for low-level environmental radiation dosimetry. Present work constitutes the first study to investigate the potentials of marble stone for reconstruction of absorbed dose in the range of 10-50 Gy dose.
  9. Ahmad N, Nawi S, Rajasekaran G, Maning N, Aziz MN, Husin A, et al.
    J Med Microbiol, 2010 Dec;59(Pt 12):1530-1532.
    PMID: 20724515 DOI: 10.1099/jmm.0.022079-0
  10. Hishamshah M, Ahmad N, Mohd Ibrahim H, Nur Halim NA, Nawi S, Amran F
    J Med Microbiol, 2018 Jun;67(6):806-813.
    PMID: 29724267 DOI: 10.1099/jmm.0.000750
    Purpose. In this study, we aim to describe and compare the demographical, clinical and laboratory features of leptospirosis and dengue co-infections (LDCI) against single leptospirosis infections in Malaysia.Methodology. Data of patients admitted to various hospitals in Malaysia from 2011 to 2015 diagnosed with leptospirosis in our laboratory were obtained from their admission records. Co-infection with dengue was determined by collecting dengue serology results. Multivariate analysis and multiple logistic regression were used to differentiate features between single leptospirosis infection and confirmed LDCI.Results/Key findings. Only 602 (29.11 %) out of 2068 leptospira-positive patients were concurrently tested for dengue during their admission in which 44 (7.31 %) patients had positive non-structural protein 1 (confirmed LDCI) while 140 (23.26 %) were positive for dengue IgM (probable LDCI) with the highest number of cases recorded in high-density suburban districts. Myalgia and arthralgia were the only significant distinguishing clinical feature of LDCI while significant laboratory features were thrombocytopenia and high levels of alanine and aspartate transaminases. Only thrombocytopenia displayed a predictive value for LDCI from analysis of multiple logistic regression. Death occurred in 19 (3.16 %) patients in this dataset studied but only three (0.50 %) were attributed to LDCI.Conclusion. There is a considerable prevalence of LDCI in this country of which overlapping demographic, clinical and laboratory presentations pose diagnostic and therapeutic challenges. Efforts to raise awareness regarding LDCI, better access to diagnostic services and further prospective studies are warranted.
  11. Lam SE, Bradley DA, Mat Nawi SN, Khandaker MU, Abdul Sani SF
    Appl Radiat Isot, 2023 Sep;199:110920.
    PMID: 37419002 DOI: 10.1016/j.apradiso.2023.110920
    The present study continues research into the utilisation of carbonaceous media for medical radiation dosimetry, focusing on the effects of surface area-to-volume ratio and carbon content on structural interaction alterations and dosimetric properties in sheet- and bead-type graphitic materials (with the respective carbon content of ∼98 wt% and ∼90 wt%). Using 60Co gamma-rays and doses from 0.5 Gy to 20 Gy, the study has been made of the response of commercially available graphite in the form of 0.1 mm, 0.2 mm, 0.3 mm and 0.5 mm thick sheets, also of activated carbon beads. Confocal Raman and photoluminescence spectroscopy have been employed, examining radiation-induced structural interaction alterations. Dose-dependent variation in the Raman intensity ratio ID/IG relates to the varying dominance of defect generation and dose-driven defect annealing. Of the various thickness graphite sheets, the 0.1 mm thick medium possesses the greatest surface area-to-volume ratio. Perhaps unsurprisingly, it also exhibits the greatest thermoluminescence (TL) yield compared to that of the other carbonaceous sheet foils used herein. Moreover, the second greatest mass-normalised TL yield has been observed to be that of the porous beads, reflected in the greater defect density (ID/IG > 2) when compared to the other media, due in part to their inherent feature of large internal surface area. Considering the challenge posed in matching skin thickness with skin dose, the near tissue equivalent graphite sheets show particular promise as a skin dosimeter, sensitive as a function of depth.
  12. Khandaker MU, Asaduzzaman Kh, Nawi SM, Usman AR, Amin YM, Daar E, et al.
    PLoS One, 2015;10(6):e0128790.
    PMID: 26075909 DOI: 10.1371/journal.pone.0128790
    The environment of the Straits of Malacca receives pollution as a result of various industrial and anthropogenic sources, making systematic studies crucial in determining the prevailing water quality. Present study concerns concentrations of natural radionuclides and heavy metals in marine fish (Rastrelliger kanagurta) collected from the Straits of Malacca, since aquatic stock form an important source of the daily diet of the surrounding populace. Assessment was made of the concentrations of key indicator radionuclides (226Ra, 232Th, 40K) and heavy metals (As, Mn, Fe, Cr, Ni, Zn, Cu, Co, Sr, Al, Hg and Pb) together with various radiation indices linked to the consumption of seafish. The annual effective dose for all detected radionuclides for all study locations has been found to be within UNSCEAR acceptable limits as has the associated life-time cancer risk. The overall contamination of the sampled fish from heavy metals was also found to be within limits of tolerance.
  13. Ahmad N, Ruzan IN, Abd Ghani MK, Hussin A, Nawi S, Aziz MN, et al.
    J Med Microbiol, 2009 Sep;58(Pt 9):1213-1218.
    PMID: 19528158 DOI: 10.1099/jmm.0.011353-0
    Community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) occurring among hospital isolates in Malaysia has not been reported previously. As CA-MRSA reported worldwide has been shown to carry SCCmec types IV and V, the aim of this study was to determine the SCCmec types of MRSA strains collected in Malaysia from November 2006 to June 2008. From a total of 628 MRSA isolates, 20 were SCCmec type IV, whilst the rest were type III. Further characterization of SCCmec type IV strains revealed 11 sequence types (STs), including ST22, with the majority being ST30/Panton-Valentine leukocidin positive. Eight out of nine CA-MRSA were ST30, one was ST80, and all were sensitive to co-trimoxazole and gentamicin. Five new STs designated ST1284, ST1285, ST1286, ST1287 and ST1288 were discovered, suggesting the emergence of novel clones of MRSA circulating in Malaysian hospitals. The discovery of the ST22 strain is a cause for concern because of its ability to replace existing predominant clones in certain geographical regions.
  14. Khandaker MU, Nawi SNM, Lam SE, Sani SFA, Islam MA, Islam MA, et al.
    Appl Radiat Isot, 2023 Jun;196:110771.
    PMID: 36933313 DOI: 10.1016/j.apradiso.2023.110771
    Thermoluminescence (TL) materials have a broad variety of uses in various fields, such as clinical research, individual dosimetry, and environmental dosimetry, amongst others. However, the use of individual neutron dosimetry has been developing more aggressively lately. In this regard, present study establishes a relationship between the neutron dosage and the optical property changes of graphite-rich materials caused by high doses of neutron radiation. This has been done with the intention of developing a novel, graphite-based radiation dosimeter. Herein, the TL yield of commercially graphite-rich materials (i.e. graphite sheet, 2B and HB grade pencils) irradiated by neutron radiation with doses ranging from 250 Gy to 1500 Gy has been investigated. The samples were bombarded with thermal neutrons as well as a negligible amount of gamma rays, from the nuclear reactor TRIGA-II installed at the Bangladesh Atomic Energy Commission. The shape of the glow curves was observed to be independent of the given dosage, with the predominant TL dosimetric peak maintained within the region of 163 °C-168 °C for each sample. By studying the glow curves of the irradiated samples, some of the most well theoretical models and techniques were used to compute the kinetic parameters such as the order of kinetics (b), activation energy (E) or trap depth, frequency factor (s) or escape probability, and trap lifetime (τ). All of the samples were found to have a good linear response over the whole dosage range, with 2B grade of polymer pencil lead graphite (PPLGs) demonstrating a higher level of sensitivity than both HB grade and graphite sheet (GS) samples. Additionally, the level of sensitivity shown by each of them is highest at the lowest dosage that was given, and it decreases as the dose increases. Importantly, the phenomenon of dose-dependent structural modifications and internal annealing of defects has been observed by assessing the area of deconvoluted micro-Raman spectra of graphite-rich materials in high-frequency areas. This trend is consistent with the cyclical pattern reported in the intensity ratio of defect and graphite modes in previously investigated carbon-rich media. Such recurrent occurrences suggest the idea of employing Raman microspectroscopy as a radiation damage study tool for carbonaceous materials. The excellent responses of the key TL properties of the 2B grade pencil demonstrate its usefulness as a passive radiation dosimeter. As a consequence, the findings suggest that graphite-rich materials have the potential to be useful as a low-cost passive radiation dosimeter, with applications in radiotherapy and manufacturing.
  15. Muslima U, Khandaker MU, Lam SE, Mat Nawi SN, Abdul Sani SF, Ung NM, et al.
    Appl Radiat Isot, 2024 Oct;212:111457.
    PMID: 39068692 DOI: 10.1016/j.apradiso.2024.111457
    In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2-10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (μg) is found to be within the range of 0.43-0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (E) and frequency factor (s) are found in the range of 0.31-0.54 eV and 4.55 × 103 to 2.12 × 106 s-1 respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.
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