Displaying all 12 publications

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  1. Man CN, Noor NM, Lajis R
    J Chromatogr A, 2011 Sep 28;1218(39):7055-60.
    PMID: 21872876 DOI: 10.1016/j.chroma.2011.08.037
    Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products.
  2. Albaroodi KA, Syed Sulaiman SA, Shafie AA, Awaisu A, Lajis R
    Value Health, 2014 Nov;17(7):A590.
    PMID: 27202012 DOI: 10.1016/j.jval.2014.08.2023
    Widespread evidence has demonstrated the negative effects of tobacco smoking in patients with diabetes. Although many studies have explored the prevalence of tobacco smoking in the general population, data are lacking regarding its prevalence in a specific population with a chronic disease such as diabetes.
    Objectives: This study aims to determine the prevalence of tobacco smoking among patients with diabetes in Hospital Pulau Pinang, Malaysia.
    Methods: A cross-sectional survey was conducted to study diabetic patients who attended the endocrine clinic at Hospital Pulau Pinang in Malaysia from March to August 2012. All the diabetic patients who attended the endocrine clinic during that period were asked about their smoking status, and their medical records were reviewed. A total of 1,118 patients with diabetes were reviewed to determine the prevalence of tobacco smoking in diabetic patients at the endocrine clinic of Hospital Pulau Pinang.
    Results: The majority of the study population was male, with Malay and Chinese patients in almost equal proportions and a smaller proportion of Indian patients. Most of these patients had started smoking before they were diagnosed with diabetes. Among the 1,118 diabetic patients, only 108 patients smoked; therefore, the prevalence of tobacco smoking in our patients with diabetes was 9.66%.
    Conclusions: A low prevalence of tobacco smoking was estimated in this study. This prevalence is close to the corresponding value in the general population in Malaysia.
    Study site: Endocrine clinic, Hospital Pulau Pinang, Malaysia
  3. Man CN, Nor NM, Lajis R, Harn GL
    J Chromatogr A, 2009 Nov 20;1216(47):8426-30.
    PMID: 19853256 DOI: 10.1016/j.chroma.2009.10.016
    Sildenafil and its analogues (tadalafil and vardenafil) are phosphodiesterase type 5 inhibitors used in the treatment of male erectile dysfunction. Some dietary supplements, herbal preparations and food products which claim to enhance male sexual function have been found to be adulterated with these drugs. In this study, a gas chromatograph-mass spectrometer (GC-MS) assay was developed for identification of the drugs. In addition to good and short chromatographic separation that can be achieved within 6 min by using a short 10 m capillary column, no prior sample clean-up before GC-MS analysis was required, thus making this assay a cost saving and rapid method. Furthermore, the assay is specific as the identification of sildenafil, tadalafil and vardenafil were done by detection of molecular ions; m/z 474, 389 and 488, [corrected] respectively, and several other characteristic ions resulted from the mass fragmentation of individual molecules. Using our currently developed assay, sildenafil and its analogues were successfully identified in food and herbal matrices.
  4. Man CN, Gam LH, Ismail S, Lajis R, Awang R
    PMID: 16908224
    Nicotine is a major addictive compound in cigarette. Its smoke is rapidly and extensively metabolized to several metabolites in human. Cotinine as a major metabolite of nicotine is commonly used as a biomarker to determine active and passive smokers. Cotinine has a longer half-life ( approximately 20 h) compared to nicotine ( approximately 2h). A simple, sensitive, rapid and high throughput GC-MS method was developed for simultaneous quantification of urinary nicotine and cotinine in passive and active smokers. In the sample preparation method, the analytes and internal standard were first basified and followed by liquid-liquid extraction. Upon completion, anhydrous sodium sulphate was added to the solvent mixture to trap moistures. The clear extract obtained was directly injected into GC-MS, operating under selective ion monitoring (SIM) mode. Calibration curves in the range of 0.5-5000 ng/mL of the analytes in urine matrix were established with linear correlation coefficients (r(2)) greater than 0.997. The limit of detection for both nicotine and cotinine were 0.20 ng/mL. The mean recoveries for nicotine and cotinine were 93.0 and 100.4%, respectively. The within- and between-assay accuracies were between 2.1 and 7.9% for nicotine and between 0.7 and 11.1% for cotinine. Within- and between-assay precisions of 3.3-9.5% for nicotine and 3.4-9.8% for cotinine were also achieved. The method can be used in routine assessment and monitoring of active smoking and exposure to environmental tobacco smoke. The applicability of the assay was demonstrated in a small-scale comparison study between smokers and non-smokers.
  5. Man CN, Ismail S, Harn GL, Lajis R, Awang R
    PMID: 19109080 DOI: 10.1016/j.jchromb.2008.12.014
    Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography-mass spectrometry (GC-MS) assay currently developed has shown to be of high throughput with average approximately 100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4 mL) of organic solvent that does not require further evaporation and salting steps prior to GC-MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5 mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r(2)>0.995), limit of quantitation (0.04 ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range.
  6. Man CN, Noor NM, Harn GL, Lajis R, Mohamad S
    J Chromatogr A, 2010 Nov 19;1217(47):7455-9.
    PMID: 20950812 DOI: 10.1016/j.chroma.2010.09.064
    Tetrodotoxin (TTX), a toxic compound found in some puffers can cause death to humans through consumption. We have developed a simplified method for the screening of TTX in puffers using GC-MS. A puffer tissue of 0.5g was treated with 5mL of 0.1% acetic acid, followed by alkaline hydrolysis, LLE or liquid-liquid extraction and N-methyl-N-TMS-trifluoroacetamide derivatization. The developed method used only a small sample and solvent, simplified LLE and derivatization procedures and short chromatographic analysis (8.2min). All of these contribute to cost-saving, enhanced sample throughput and high sensitivity of the screening assay. The developed method was validated and proved to be within the acceptable range.
  7. Albaroodi KA, Syed Sulaiman SA, Awaisu A, Shafie AA, Lajis R, Abo-Maali MF
    Value Health, 2015 Nov;18(7):A714.
    PMID: 26533997 DOI: 10.1016/j.jval.2015.09.2692
    Objectives
    Endocrinologists and other clinicians who provide care to diabetic patients have ideal teaching opportunities to connect and deliver tobacco cessation interventions in diabetes care. This study aimed to develop, validate and measure the reliability of a new tool that would be used to evaluate physicians’ attitudes and practices regarding tobacco cessation counselling in patients with diabetes, as well as barriers to deliver tobacco cessation counselling in their clinics.

    Methods
    This study was conducted from March till December 2012 in the endocrine clinic at Hospital Pulau Pinang, Malaysia. A standardised, 22-item, self-administered questionnaire was developed to determine (i) physicians’ attitudes and practices regarding tobacco cessation counselling in patients with diabetes, and (ii) barriers in delivering tobacco cessation counselling in their clinics. Face and content validity were assessed. Six pharmacists, whom were faculty members with experience and expertise in research and in the development of surveys, reviewed the questionnaire to assess its content validity.Reliability test was run along to check whether the new tool questions are correlated with one another adequatly or no.

    Results
    Reliability test for the tool was pretested on a sample of 25 physicians physicians who ran the endocrine clinic at Hospital Pulau Pinang, Malaysia. Reliability analyses for the attitude domain and practice domain were 0.710 and 0.720, respectively.

    Conclusions
    The questionnaire was valid and reliable to be use for the evaluation of physician’s barriers, attitude and practice regarding tobacco cessation counselling in the diabetics clinics.
  8. Gan EK, Abdul Razak D, Mohamad M, Lajis R, Tan KC, Sam TW
    Med J Malaysia, 1984 Mar;39(1):42-7.
    PMID: 6513839
    Aqueous root extract of Selayak Hitam a plant commonly found in Malaysian jungles and reported to have abortifacient property was screened for oxytocic effect. Results obtained from in vitro experiments on isolated uterus preparation from both pregnant and non pregnant rats and in vivo experiments on uterus contraction in rats in situ, showed that the extract lacks oxytocic effect. It is concluded that the alleged abortifacient property if any, is not mediated through oxytocin or oxytocic-like effect.
  9. Abdul Razak D, Gan EK, Mohamad M, Lajis R, Sam TW
    Med J Malaysia, 1984 Mar;39(1):48-51.
    PMID: 6513840
    Studies made on aqueous root extract of Selayak Hitam, a plant alleged to possess abortifacient activity in pregnant mothers established that the extract is teratogenic and did in fact cause abortion in mice. It was also observed that the aqueous root extract is relatively toxic as judged by the number of deaths occuring following administration of the extract. The mechanism by which abortion is brought about is unknown but it is possible that the abortifacient effect is due to the induced teratogenic activity, brought about by the extract.
  10. Awang R, Abd Rahman AF, Wan Abdullah WZA, Lajis R, Abdul Majid MI
    Med J Malaysia, 2003 Aug;58(3):375-9.
    PMID: 14750377
    This report describes inquiries relating to poisoning cases which were received by the National Poison Centre of Malaysia from the years 1996 to 2000. The study utilized data from the NPC report forms. Only data relating to patient contact with a poison or chemical were included in the analysis. The poison centre received an average of 186 poisoning inquiries per year. Doctors remained the highest group of caller to the poison centre throughout the five-year period. Nearly 50% of all inquiries was regarding pesticide poisoning and this trend remained constant during the five-year period. Overall, the findings showed that poisoning inquiries relating to patient care were lower than in Japan and the United States.
  11. Yong YV, Mahamad Dom SH, Ahmad Sa'ad N, Lajis R, Md Yusof FA, Abdul Rahaman JA
    MDM Policy Pract, 2021 03 30;6(1):2381468321994063.
    PMID: 33855190 DOI: 10.1177/2381468321994063
    Objectives. The current health technology assessment used to evaluate respiratory inhalers is associated with limitations that have necessitated the development of an explicit formulary decision-making framework to ensure balance between the accessibility, value, and affordability of medicines. This study aimed to develop a multiple-criteria decision analysis (MCDA) framework, apply the framework to potential and currently listed respiratory inhalers in the Ministry of Health Medicines Formulary (MOHMF), and analyze the impacts of applying the outputs, from the perspective of listing and delisting medicines in the formulary. Methods. The overall methodology of the framework development adhered to the recommendations of the ISPOR MCDA Emerging Good Practices Task Force. The MCDA framework was developed using Microsoft Excel 2010 and involved all relevant stakeholders. The framework was then applied to 27 medicines, based on data gathered from the highest levels of available published evidence, pharmaceutical companies, and professional opinions. The performance scores were analyzed using the additive model. The end values were then deliberated by an expert committee. Results. A total of eight main criteria and seven subcriteria were determined by the stakeholders. The economic criterion was weighted at 30%. Among the noneconomic criteria, "patient suitability" was weighted the highest. Based on the MCDA outputs, the expert committee recommended one potential medicine (out of three; 33%) be added to the MOHMF and one existing medicine (out of 24; 4%) be removed/delisted from the MOHMF. The other existing medicines remained unchanged. Conclusions. Although this framework was useful for deciding to add new medicines to the formulary, it appears to be less functional and impactful for the removal/delisting existing medicines from the MOHMF. The generalizability of this conclusion to other formulations remains to be confirmed.
  12. Man CN, Fathelrahman AI, Harn GL, Lajis R, Samin AS, Omar M, et al.
    Environ Toxicol Pharmacol, 2009 Jul;28(1):92-6.
    PMID: 21783987 DOI: 10.1016/j.etap.2009.03.003
    The objective of this study was to correlate, differentiate and validate the self-reported smoking status of educated young adults with urinary biomarkers (i.e. nicotine and cotinine). Freshmen students were recruited on voluntary basis. They filled-up self-administered questionnaire and their urine samples were collected for analysis. The urinary nicotine (UN) and cotinine (UC) were measured by gas chromatograph-mass spectrometry. Smokers, non-smokers and ex-smokers were found to be both significantly correlated and different in their UN and UC levels. UC level of 25ng/ml was the optimal cut-off to differentiate smokers from non-smokers. Using this cut-off value, the prevalence of smoking among the students was found to be higher (15.4%) than the self-reported data (14.3%). UC is useful in validating individual recent smoking history and the cut-off could serve as a marker for assessing the clinical impact of smoking and environmental tobacco smoke (ETS) exposure on human health.
    Study site: university health centre, Universiti SainsMalaysia (USM), Pulau Pinang, Malaysia
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