Displaying publications 101 - 120 of 533 in total

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  1. Jean YQ, Mazlan R, Ahmad M, Maamor N
    Am J Audiol, 2018 Sep 12;27(3):260-271.
    PMID: 30007031 DOI: 10.1044/2018_AJA-17-0093
    Purpose: The aim of this study was to develop a substantive theory that explains parenting stress among mothers of deaf or hard-of-hearing (D/HH) children.

    Method: Fifteen hearing mothers of children with severe-to-profound sensorineural hearing loss were interviewed. Interviews were transcribed verbatim, and a grounded theory approach was used to inductively analyze parental stress in mothers of D/HH children. Theory generation was achieved through triangulation of data sources and systematic organization of data into codes. The coding process identified salient themes that were constantly cross-checked and compared across data to further develop categories, properties, and tentative hypotheses.

    Results: In general, two main themes emerged from the interviews: the contextual stressors and stress-reducing resources. The contextual stressors were labeled as distress over audiology-related needs, pressure to acquire new knowledge and skills, apprehension about the child's future, and demoralizing negative social attitudes. The stress-reducing resources that moderated parenting stress were identified to be the child's progress, mother's characteristics, professional support, and social support. The interaction between the identified stressors and adjustment process uncovered a central theme termed maternal coherence.

    Conclusion: The substantive theory suggests that mothers of D/HH children can effectively manage parenting stress and increase well-being by capitalizing on relevant stress-reducing resources to achieve maternal coherence.

  2. Ahmad MI, Khan IA, Ahmad M, Husain A, Jamaludin R
    Syst Pract Action Res, 2021 Nov 20.
    PMID: 34840496 DOI: 10.1007/s11213-021-09585-6
    Every individual is unique and may serve a unique purpose in this life. Education is widely accepted to be the means of transformation of individuals so that they may achieve their unique success or create their own lives. However, not every individual seems to be realizing their true potential. This paper explores the concept of entropy in education system as a force that is usually imagined to oppose realization of potential of an individual during life in this phenomenal world. Alternatively, the same may provide an impetus that is necessary to bring in organization in oneself to realize the hidden potential. A one group Pretest-Posttest quasi-experimental design was used to draw the conclusions on data obtained from participants of workshops in three different modes, viz. face-to-face Pre COVID-19, face-to-face in COVID-19 with SOPs, and online in COVID-19. Realization of an individual's potential was represented as a dependent variable, i.e. transformation in cognition, skills, and attitude while the independent variables taken into account were the meaningful interactions of an individual with peers and advanced learners in a designed environment. It was inferred from the results that transformation in learners' cognition (6-30 %), skills (0-20 %), and attitude (5-32 %) occurred through human discourse, in a community of inquiry.
  3. Arshad AH, Azrai Abu M, Ahmad MF, Abdul Karim AK
    Med J Malaysia, 2022 Jan;77(1):1-5.
    PMID: 35086987
    INTRODUCTION: Endometriosis is a challenging disease to treat, and patients may eventually need in vitro fertilisation with Intracytoplasmic sperm injection (IVF/ICSI) to conceive after other modalities failed. There are inconsistent outcomes of IVF performance in patients with endometriosis especially with highly purified human menotropin gonadotrophin (hMG). This study was commenced to determine whether the use of hMG affects the IVF outcome in different stage of endometriosis.

    MATERIALS AND METHODS: This is an observational study. Eighty-seven women who had endometriosis confirmed surgically and underwent IVF/ICSI treatment, stimulated with hMG alone were included. Based on the revised American Society for Reproductive Medicine (rASRM), the participants were classified as early endometriosis (I/II) (n=39) or advanced endometriosis (III/IV) (n=35). The main outcome measures used were clinical pregnancy rate.

    RESULTS: Women with advanced endometriosis had a lower oocyte yield, less good quality day-3 embryos and lower clinical pregnancy rate compared with the mild endometriosis. However, higher fertilisation rate were recorded in advanced stage endometriosis compared to milder disease.

    CONCLUSIONS: The rASRM classification of endometriosis is valuable in predicting IVF outcome as advanced endometriosis performs poorly compared to a milder disease. Highly purified hMG could be an alternative as an ovarian stimulation in endometriosis.

  4. Yam MF, Tan CS, Ahmad M, Ruan S
    Am J Chin Med, 2016;44(7):1413-1439.
    PMID: 27785939
    Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O. stamineus. The vasorelaxant activity and the underlying mechanisms of the chloroform fraction of the 50% methanolic extract of O. stamineus (CF) was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. CF caused relaxation of the aortic ring pre-contracted with phenylephrine in the presence and absence of endothelium, and pre-contracted with potassium chloride in endothelium-intact aortic ring. In the presence of endothelium, both indomethacin (a nonselective cyclooxygenase inhibitor) and [Formula: see text]-[1,2,4]Oxadiazolo[4,3-[Formula: see text]]quinoxalin-1-one (ODQ, selective soluble guanylate cyclase inhibitor) had a small effect on the vasorelaxation response. On the other hand, in the presence of Nω-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor), methylene blue (cyclic guanosine monophosphate lowering agent), tetraethylammonium ([Formula: see text], nonselective calcium activator [Formula: see text] channel blocker), 4-aminopyridine (4-AP, voltage-dependent [Formula: see text] channel blocker), barium chloride ([Formula: see text], inwardly rectifying [Formula: see text] channel blocker), glibenclamide (nonspecific ATP-sensitive [Formula: see text] channel blocker), atropine (muscarinic receptor blocker) and propranolol (β-adrenergic receptor blocker), the vasorelaxant effect significantly reduced the relaxation stimulated by CF. CF was also found to be active in reducing [Formula: see text] release from the sarcoplasmic reticulum and blocking calcium channels.
  5. Borromeo GL, Ahmad MS, Buckley S, Bozanic M, Cao A, Al-Dabbagh M, et al.
    Eur J Dent Educ, 2018 Aug;22(3):e321-e326.
    PMID: 29024268 DOI: 10.1111/eje.12296
    INTRODUCTION: The role of dental auxiliaries in collaborative care of patients with special needs is compelling. This study was undertaken to investigate the perceptions of Special Needs Dentistry (SND) education and practice amongst students enrolled in Australian programmes in dental auxiliary, namely dental hygiene, dental therapy and oral health therapy (DH/DT/OHT).

    MATERIALS AND METHODS: All Australian institutions offering DH/DT/OHT programmes (n = 14) were invited to participate in a self-administered questionnaire survey, conducted online, involving students across all academic years. Twelve institutions agreed to participate, but only five institutions were included in the final analysis, with a student response rate of 31.1%. Answers to open-ended questions were coded and grouped for measurement of frequencies. Quantitative data were analysed via chi-squared and Fisher's exact tests (significance taken as P 

  6. Abdullah J, Ahmad M, Heng LY, Karuppiah N, Sidek H
    Sensors (Basel), 2007 Oct 11;7(10):2238-2250.
    PMID: 28903224 DOI: 10.3390/s7102238
    The fabrication of an optical biosensor by using stacked films where 3-methyl-2-benzothiazolinone hydrazone (MBTH) was immobilized in a hybrid nafion/sol-gelsilicate film and laccase in a chitosan film for the detection of phenolic compounds wasdescribed. Quinone and/or phenoxy radical product from the enzymatic oxidation ofphenolic compounds was allowed to couple with MBTH to form a colored azo-dye productfor spectrophometric detection. The biosensor demonstrated a linear response to catecholconcentration range of 0.5-8.0 mM with detection limit of 0.33 mM and response time of10 min. The reproducibility of the fabricated biosensor was good with RSD value of 5.3 %(n = 8) and stable for at least 2 months. The use of the hybrid materials of nafion/sol-gelsilicate to immobilize laccase has altered the selectivity of the enzyme to various phenoliccompounds such as catechol, guaicol, o-cresol and m-cresol when compared to the non-immobilized enzyme. When immobilized in this hybrid film, the biosensor response onlyto catechol and not other phenolic compounds investigated. Immobilization in this hybridmaterial has enable the biosensor to be more selective to catechol compared with the non-immobilized enzyme. This shows that by a careful selection of different immobilizationmatrices, the selectivity of an enzyme can be modified to yield a biosensor with goodselectivity towards certain targeted analytes.
  7. Hasan MK, Ahamed MA, Ahmad M, Rashid MA
    Appl Bionics Biomech, 2017;2017:6848014.
    PMID: 28894351 DOI: 10.1155/2017/6848014
    Electroencephalographic signal is a representative signal that contains information about brain activity, which is used for the detection of epilepsy since epileptic seizures are caused by a disturbance in the electrophysiological activity of the brain. The prediction of epileptic seizure usually requires a detailed and experienced analysis of EEG. In this paper, we have introduced a statistical analysis of EEG signal that is capable of recognizing epileptic seizure with a high degree of accuracy and helps to provide automatic detection of epileptic seizure for different ages of epilepsy. To accomplish the target research, we extract various epileptic features namely approximate entropy (ApEn), standard deviation (SD), standard error (SE), modified mean absolute value (MMAV), roll-off (R), and zero crossing (ZC) from the epileptic signal. The k-nearest neighbours (k-NN) algorithm is used for the classification of epilepsy then regression analysis is used for the prediction of the epilepsy level at different ages of the patients. Using the statistical parameters and regression analysis, a prototype mathematical model is proposed which helps to find the epileptic randomness with respect to the age of different subjects. The accuracy of this prototype equation depends on proper analysis of the dynamic information from the epileptic EEG.
  8. Bahari R, Mohamad Alwi MN, Ahmad MR, Mohd Saiboon I
    Malays Fam Physician, 2017;12(3):2-7.
    PMID: 29527273 MyJurnal
    Introduction: Motor vehicle accidents (MVAs) are daily occurrences in Malaysia but the extent to which victims are psychologically affected is not well known. The objective of this study is to determine the incidence and demographic characteristics of patients with post-traumatic stress disorder (PTSD) due to MVAs at a university hospital in Malaysia.

    Methods: Patients presenting to the emergency department from August to October 2014 due to MVA-related injuries were recruited. After a period of at least one month, they were followed-up and screened using the validated Malay Post Traumatic Stress Disorder Checklist Civilian version. A score of 30 was chosen as the cut-off point for PTSD.

    Results: In total, 112 patients presented to the emergency department following MVAs during the study period. Of these, 60.7% agreed for the follow-up. Among the respondents, the mean age was 26 years, 91.2% were males, 66.2% were married, 85.3% were Malays and 88.3% were Muslims. The calculated incidence of PTSD was 7.4%. There was no significant difference noted between the PTSD and non-PTSD groups.

    Conclusion: A considerable number of MVA victims in Malaysia may develop PTSD after the accident. Further research is needed to explore the factors that contribute or protect to develop the condition.

  9. Widyawati T, Yusoff NA, Bello I, Asmawi MZ, Ahmad M
    Molecules, 2022 Oct 12;27(20).
    PMID: 36296407 DOI: 10.3390/molecules27206814
    (1) Background: An earlier study on the hypoglycemic activity of S. polyanthum (Wight.) leaf methanol extract identified squalene as the major chemical compound. The present study was conducted to assess the hypoglycemic effect of fractions and subfractions of the methanol extract of S. polyanthum compared to the squalene using a bioassay-guided in vivo study. (2) Methods: The methanol extract was fractionated using the liquid−liquid fractionation method. Streptozotocin-induced type 1 diabetic rat was used to study the hypoglycemic effect. (3) Results: The findings showed that chloroform fraction significantly (p < 0.05) lowered blood glucose levels of diabetic rats as compared to the control. Further fractionation of chloroform fraction yielded subfraction-1 and -2, whereby subfraction-1 exhibited a higher blood-glucose-lowering effect. The lipid profile test showed that the total cholesterol level of subfraction-1 and squalene-treated groups decreased significantly (p < 0.05). An immunohistochemistry study revealed that none of the treatments regenerated pancreatic β-cells. Gas chromatography−mass spectrophotometer analysis identified the presence of squalene in the active methanol extract, chloroform fraction, and subfraction-1. In silico analysis revealed a higher affinity of squalene against protein receptors that control lipid metabolism than metformin. (4) Conclusions: Data obtained from the present work suggested the crude methanol extract exerted the highest hypoglycemic effect compared to fraction, subfraction, and squalene, confirming synergistic effect may be responsible for the hypoglycemic activity of S. polyanthum.
  10. Khandanlou R, Bin Ahmad M, Shameli K, Kalantari K
    Molecules, 2013 Jun 05;18(6):6597-607.
    PMID: 23739066 DOI: 10.3390/molecules18066597
    Small sized magnetite iron oxide nanoparticles (Fe3O4-NPs) with were successfully synthesized on the surface of rice straw using the quick precipitation method in the absence of any heat treatment. Ferric chloride (FeCl3·6H2O), ferrous chloride (FeCl2·4H2O), sodium hydroxide (NaOH) and urea (CH4N2O) were used as Fe3O4-NPs precursors, reducing agent and stabilizer, respectively. The rice straw fibers were dispersed in deionized water, and then urea was added to the suspension, after that ferric and ferrous chloride were added to this mixture and stirred. After the absorption of iron ions on the surface layer of the fibers, the ions were reduced with NaOH by a quick precipitation method. The reaction was carried out under N2 gas. The mean diameter and standard deviation of metal oxide NPs synthesized in rice straw/Fe3O4 nanocomposites (NCs) were 9.93 ± 2.42 nm. The prepared rice straw/Fe3O4-NCS were characterized using powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) and Fourier transforms infrared spectroscopy (FT‒IR). The rice straw/Fe3O4-NCs prepared by this method have magnetic properties.
  11. Ahmad M, Ahmad A, Omar TFT, Mohammad R
    Crit Rev Anal Chem, 2023 Apr 13.
    PMID: 37052389 DOI: 10.1080/10408347.2023.2199432
    Increasing acidity of seawater caused by increasing anthropogenic carbon dioxide absorbed into the seawater attracted the interest of researchers due to increased concern on the deterioration of marine systems and food supply to humans. Total alkalinity (TA) is one of the important parameters in determining carbonate chemistry and is described as the capacity of the sample to neutralize acids. Over the last two decades, many analytical techniques have been developed to determine TA. This article presents a review of different analytical techniques including titration, colorimetric, spectrophotometric, and potentiometric analyses in measuring TA. Among these analytical techniques, potentiometry analysis, which utilizes electrode systems such as glass electrode and ion-selective electrode used as indicator electrodes, is the most used technique. Important features such as principle, limitations, and challenges of the involved technique are discussed in detail.
  12. Al-Ahmad M, Ali A, Khalaf M, Alterki A, Rodriguez-Bouza T
    BMC Pulm Med, 2023 Jul 18;23(1):266.
    PMID: 37464395 DOI: 10.1186/s12890-023-02556-8
    BACKGROUND: The clinical heterogeneity of chronic rhinosinusitis (CRS) and bronchial asthma is attributable to different underlying inflammatory profiles. However, the similarity between CRS with nasal polyps (CRSwNP) and type-2 asthma pathophysiology speculates that one biological therapy could affect both comorbidities. Despite dupilumab, a monoclonal antibody that targets IL-4α and IL-13 receptors, being used in patients with nasal polyps and severe asthma, real-life data about its efficacy in improving the quality of life and patient symptoms is still lacking. This study's primary objective was to evaluate dupilumab treatment's effect on the frequency of olfactory symptoms and health-related quality of life tests as measured by the Sino-nasal outcome test (SNOT-22) in patients with NP. The secondary objective was the effect of dupilumab on asthma symptom control as measured by the asthma control test (ACT).

    METHODS: A prospective study was conducted of 166 patients with CRSwNP, with or without asthma. The following variables were collected at baseline and after at least six months of continuous dupilumab therapy; SNOT-22, olfactory symptoms frequency, and ACT score.

    RESULTS: Asthma prevalence in patients with CRSwNP was high (59.63%), and being female with a history of frequent use of oral corticosteroid (OCS) courses and repeated unsuccessful nasal and para-nasal surgeries for polyposis increased the likelihood of having underlying asthma by 2, 1 and 4 times more, respectively. Additionally, being asthmatic required a longer duration of dupilumab treatment. However, both the health-related quality of life and olfactory symptoms improved equally in both groups.

    CONCLUSION: Even with associated comorbid asthma in patients with CRSwNP, treatment with dupilumab could improve the quality of life, olfactory symptoms, and asthma symptom control.

  13. Daker M, Lin VY, Akowuah GA, Yam MF, Ahmad M
    Exp Ther Med, 2013 Jun;5(6):1701-1709.
    PMID: 23837058
    Nasopharyngeal carcinoma (NPC) is a malignancy that occurs in the epithelium of the nasopharynx. The standard treatment of NPC patients with locoregionally advanced stages is problematic and is often associated with toxicities. Therefore, it is essential to screen for naturally occurring compounds with strong apoptosis-inducing activity and minimal toxicity. This study investigated the effects of the standardized methanol extract of Cinnamomum burmannii Blume stem bark and its main constituent, trans-cinnamaldehyde (TCA), on human NPC cell lines. The content of TCA in C. burmannii methanol extract was standardized to be 13.61% w/w by means of gas chromatography-mass spectrometry (GC-MS). NPC cell proliferation was clearly inhibited within 24 h of treatment, with TCA exhibiting greater activity than the methanol extract. TCA was more active against NPC cells compared with cisplatin. There was a pronounced downregulation of the proliferation markers, Ki67 and proliferating cell nuclear antigen (PCNA) in the TCA-treated cells; while morphological observation indicated the induction of apoptosis. Caspase activation and prominent DNA damage, which are markers of apoptosis induction were detected. TCA demonstrated the ability to scavenge nitric oxide. The simultaneous combination of TCA and cisplatin produced synergistic anti-proliferative effects. Collectively, these data indicate the potential use of TCA for the treatment of NPC.
  14. Ashraf MA, Khan AM, Ahmad M, Sarfraz M
    Front Chem, 2015;3:42.
    PMID: 26322304 DOI: 10.3389/fchem.2015.00042
    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.
  15. Ali I, Ahmad M, Ridha S, Iferobia CC, Lashari N
    RSC Adv, 2023 Nov 07;13(47):32904-32917.
    PMID: 38025871 DOI: 10.1039/d3ra06008j
    In the context of deep well drilling, the addition of functionalized additives into mud systems becomes imperative due to the adverse impact of elevated borehole temperatures and salts on conventional additives, causing them to compromise their intrinsic functionalities. Numerous biomaterials have undergone modifications and have been evaluated in drilling muds. However, the addition of dually modified tapioca starch in bentonite-free mud systems remains a notable gap within the existing literature. This study aims to examine the performance of dually modified carboxymethyl irradiated tapioca starch (CMITS) under high temperature and salt-containing conditions employing central composite design approach; the study evaluates the modified starch's impact on mud rheology, thermal stability, and salt resistance. The findings indicated that higher DS (0.66) and CMITS concentrations (8 ppb) improved plastic viscosity (PV), yield point (YP) and gel strength (GS), while increased salt and temperature decreased it, demonstrating the complex interplay of these factors on mud rheology. The developed empirical models suggested that DS 0.66 starch addition enhanced rheology, especially at elevated temperatures, demonstrating improved borehole cleaning potential, supported by quadratic model performance indicators in line with American Petroleum Institute (API) ranges. The optimized samples showed a non-Newtonian behavior, and Power-law model fitting yields promising results for improved cuttings transportation with starch additives.
  16. Chin AHB, Al-Balas Q, Ahmad MF, Alsomali N, Ghaly M
    J Bioeth Inq, 2023 Dec 04.
    PMID: 38047997 DOI: 10.1007/s11673-023-10293-0
    In recent years, the genetic testing and selection of IVF embryos, known as preimplantation genetic testing (PGT), has gained much traction in clinical assisted reproduction for preventing transmission of genetic defects. However, a more recent ethically and morally controversial development in PGT is its possible use in selecting IVF embryos for optimal intelligence quotient (IQ) and other non-disease-related socially desirable traits, such as tallness, fair complexion, athletic ability, and eye and hair colour, based on polygenic risk scores (PRS), in what is referred to as PGT-P. Artificial intelligence (AI) and machine learning-based analysis of big data sets collated from genome sequencing of specific human ethnic populations can be used to estimate an individual embryo's likelihood of developing such multifactorial traits by analysing the combination of specific genetic variants within its genome. Superficially, this technique appears compliant with Islamic principles and ethics. Because there is no modification of the human genome, there is no tampering with Allah's creation (taghyīr khalq Allah). Nevertheless, a more critical analysis based on the five maxims of Islamic jurisprudence (qawa'id fiqhiyyah) that are often utilized in discourses on Islamic bioethics, namely qaṣd (intention), yaqın̄ (certainty), ḍarar (injury), ḍarūra (necessity), and `urf (custom), would instead reveal some major ethical and moral flaws of this new medical technology in the selection of non-disease-related socially desirable traits, and its non-compliance with the spirit and essence of Islamic law (shariah). Muslim scholars, jurists, doctors, and biomedical scientists should debate this further and issue a fatwa on this new medical technology platform.
  17. Hossain MA, Ahmad M, Islam MR, David Y
    Health Technol (Berl), 2020;10(2):547-561.
    PMID: 32432021 DOI: 10.1007/s12553-019-00390-9
    At present, the patient care delivery system (PCDS) in a hospital/medical institute/clinic is absolutely medical technology-dependent and this tendency is found to increase day by day. To ensure the quality of patient care (QPC) appropriate implementation of the patient care technology management system (PCTMS) is necessary. Unfortunately, it is found to be absent in the healthcare delivery system in most of the countries in the world. The situation is very much severe, particularly, in medium- and low-income countries like Malaysia, India, Sri Lanka, Bangladesh, Pakistan, etc. The opposite scenario is found in high-income countries, specifically, in Japan where QPC has been improved significantly by adopting the clinical engineering approach (CEA) in their PCDS. Up to now, QPC is determined based on prediction as there are no mathematical ways to evaluate it properly. In this study, we for the first time, propose a mathematical model to evaluate the QPC quantitatively based on feedback control analogy taking into account of CEA in PCTMS, particularly, for clinical and surgical equipment. The model consists of three subsections: the clinical engineering department (CED), PCTMS, and health care engineering directorate (HCED). The correlation among the subsections and their performance parameters are defined and standardized. Multiple linear regression method is applied to derive the least square normal equations for each of the subsections and then the regression coefficients are solved by the standard data taken from 1000 beds hospitals of different countries. The model is applied to reveal the present status of QPC for 18 different countries including high-, middle-, and low-income countries of the world. The results obtained from the model demonstrate that the present status of QPC in Japan is 84.69% and in Pakistan, it is only 0.20%. This huge discrepancy is identified to be caused by the inclusion of CEA in PCDS of Japan. The proposed model can be applied to evaluate the QPC of a hospital/in a country and hence to take necessary steps accordingly for establishing the proposed research methodology. It is to be mentioned here that the proposed model cannot be applied to evaluate the QPC in some countries like Bangladesh, Bhutan, Nepal, etc. due to the unavailability of data related to the model parameters.
  18. Akash M, Zaib S, Ahmad M, Sultan S, Al-Hussain SA
    Front Chem, 2024;12:1371377.
    PMID: 38545466 DOI: 10.3389/fchem.2024.1371377
    Urease, a nickel-dependent enzyme found in various life forms, catalyzes urea breakdown, concluding nitrogen metabolism by generating ammonia and carbamate. This process causes a rise in pH, supports the survival of pathogens, and can lead to infections such as gastric disorders like ulcers and cancer in humans. Helicobacter pylori employs urease for survival in the acidic environment of the stomach and in protein synthesis. To treat such infections and inhibit the growth of pathogens, it is mandatory to obstruct urease activity; therefore, derivatives of 1-(3-nitropyridin-2-yl)piperazine were synthesized (5a-o; 7a-k). All these newly synthesized compounds were investigated for urease inhibition by in vitro inhibition assays. The results showed that 5b and 7e are the most active inhibitors, having IC50 values of 2.0 ± 0.73 and 2.24 ± 1.63 µM, respectively. These IC50 values are lower than the IC50 value of the standard thiourea, which was 23.2 ± 11.0 µM. The hemolysis potential of 5b, 5c, 5i, 7e, and 7h was also determined; 7e and 7h exhibited good biocompatibility in human blood cells. Through in silico analysis, it was shown that both these potent inhibitors develop favorable interactions with the active site of urease, having binding energies of -8.0 (5b) and -8.1 (7e) kcal/mol. The binding energy of thiourea was -2.8 kcal/mol. Moreover, 5b and 7e have high gastrointestinal permeability as predicted via computational analysis. On the other hand, the IC50 value and binding energy of precursor compound 3 was 3.90 ± 1.91 µM and -6.1 kcal/mol, respectively. Consequently, 5b and 7e can serve as important inhibitors of urease.
  19. Daker M, Bhuvanendran S, Ahmad M, Takada K, Khoo AS
    Mol Med Rep, 2013 Mar;7(3):731-41.
    PMID: 23292678 DOI: 10.3892/mmr.2012.1253
    Nasopharyngeal carcinoma (NPC) is a unique tumour of epithelial origin with a distinct geographical distribution, closely associated with the Epstein‑Barr virus (EBV). EBV‑encoded RNAs (EBERs) are small non‑polyadenylated RNAs that are abundantly expressed in latent EBV‑infected NPC cells. To study the role of EBERs in NPC, we established stable expression of EBERs in HK1, an EBV‑negative NPC cell line. Cells expressing EBERs consistently exhibited an increased growth rate. However, EBERs did not confer resistance towards cisplatin‑induced apoptosis or promote migration or invasion ability in the cells tested. Using microarray gene expression profiling, we identified potential candidate genes that were deregulated in NPC cells expressing EBERs. Gene Ontology analysis of the data set revealed that EBERs upregulate the cellular lipid metabolic process. Upregulation of low‑density lipoprotein receptor (LDLR) and fatty acid synthase (FASN) was observed in EBER‑expressing cells. NPC cells exhibited LDL‑dependent cell proliferation. In addition, a polyphenolic flavonoid compound, quercetin, known to inhibit FASN, was found to inhibit proliferation of NPC cells.
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