Displaying publications 81 - 100 of 325 in total

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  1. Al-Dabbagh MM, Salim N, Himmat M, Ahmed A, Saeed F
    J Comput Aided Mol Des, 2017 Apr;31(4):365-378.
    PMID: 28220440 DOI: 10.1007/s10822-016-0003-4
    Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.
  2. Rasiah R, Ahmed A, Al-Amin AQ, Chenayah S
    Environ Sci Pollut Res Int, 2017 Jan;24(3):2632-2642.
    PMID: 27830414 DOI: 10.1007/s11356-016-7985-2
    This paper analyses empirically the optimal climate change mitigation policy of Malaysia with the business as usual scenario of ASEAN to compare their environmental and economic consequences over the period 2010-2110. A downscaling empirical dynamic model is constructed using a dual multidisciplinary framework combining economic, earth science, and ecological variables to analyse the long-run consequences. The model takes account of climatic variables, including carbon cycle, carbon emission, climatic damage, carbon control, carbon concentration, and temperature. The results indicate that without optimal climate policy and action, the cumulative cost of climate damage for Malaysia and ASEAN as a whole over the period 2010-2110 would be MYR40.1 trillion and MYR151.0 trillion, respectively. Under the optimal policy, the cumulative cost of climatic damage for Malaysia would fall to MYR5.3 trillion over the 100 years. Also, the additional economic output of Malaysia will rise from MYR2.1 billion in 2010 to MYR3.6 billion in 2050 and MYR5.5 billion in 2110 under the optimal climate change mitigation scenario. The additional economic output for ASEAN would fall from MYR8.1 billion in 2010 to MYR3.2 billion in 2050 before rising again slightly to MYR4.7 billion in 2110 in the business as usual ASEAN scenario.
  3. Muna KA, Mokhtar A, Saad MA, Ahmed AA, Akbar JB
    MyJurnal
    Introduction: Leptin is an adipokine that has strong correlation with the body mass index (BMI). Gestational diabetes mellitus (GDM) is a common medical complication associated with pregnancy. Leptin may lose its correlation with the body mass index (BMI) during diabetes due to hormonal rearrangement. Diet control is the first line management in GDM. Leptin reported to increase in pregnancy and further increases in diabetic patients during GDM screening. There is paucity in the reports concerning Leptin levels in GDM patients on diet control. The present study was aimed to evaluate the changes in maternal leptin in pregnancy complicated by GDM on diet control compared to the normal pregnancy in the 3rd trimesters by comparing the means and to find the correlation of Leptin with the body mass index in both groups.
    Methods: The study included 2 groups: normal pregnancy (n = 40) and pregnancy with GDM under diet control (n = 60) both groups are at 38-40 weeks of gestation. Leptin concentration in serum was measured in both groups and statistically tested using student t test. The BMI were measured and correlated with the Leptin level in test groups.
    Results: the results indicated that Leptin will nearly triple in the third trimester (38±30 ng/ml) of pregnancy compared to the standard normal non-pregnant. Leptin level was significantly lower in diabetic women on diet control (28±16 ng/ ml) when compared with the non-diabetics (38±30 ng/ml). The hormone has no correlation with the age of the patients but have a positive correlation with the body mass index before and during pregnancy in both groups.
    Conclusion: Leptin is increasing in pregnancy as part of the physiological changes. Dieting can decrease Leptin level in diabetics’ pregnant women. Diet can restore the hormonal dysregulation of Leptin. Assessment of Leptin level might be used as an indicator for good diet control during pregnancy.
    Study site: Hospital Tengku Ampuan Afzan (HTAA), Kuantan, Pahang, Malaysia
  4. Ullah I, Hassan W, Tahir MJ, Ahmed A
    J Med Virol, 2021 Oct;93(10):5689-5690.
    PMID: 34143897 DOI: 10.1002/jmv.27134
  5. Abdo A, Saeed F, Hamza H, Ahmed A, Salim N
    J Comput Aided Mol Des, 2012 Mar;26(3):279-87.
    PMID: 22249773 DOI: 10.1007/s10822-012-9543-4
    Query expansion is the process of reformulating an original query to improve retrieval performance in information retrieval systems. Relevance feedback is one of the most useful query modification techniques in information retrieval systems. In this paper, we introduce query expansion into ligand-based virtual screening (LBVS) using the relevance feedback technique. In this approach, a few high-ranking molecules of unknown activity are filtered from the outputs of a Bayesian inference network based on a single ligand molecule to form a set of ligand molecules. This set of ligand molecules is used to form a new ligand molecule. Simulated virtual screening experiments with the MDL Drug Data Report and maximum unbiased validation data sets show that the use of ligand expansion provides a very simple way of improving the LBVS, especially when the active molecules being sought have a high degree of structural heterogeneity. However, the effectiveness of the ligand expansion is slightly less when structurally-homogeneous sets of actives are being sought.
  6. Ahmed AB, Rao AS, Rao MV, Taha RM
    ScientificWorldJournal, 2012;2012:897867.
    PMID: 22629221 DOI: 10.1100/2012/897867
    Gymnema sylvestre (R.Br.) is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA). The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L) and KN (0.5 mg/L). Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w) was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w). Maximum GA production (58.28 mg/g d.w) was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors.
  7. Saeed F, Ahmed A, Shamsir MS, Salim N
    J Comput Aided Mol Des, 2014 Jun;28(6):675-84.
    PMID: 24830925 DOI: 10.1007/s10822-014-9750-2
    The cluster-based compound selection is used in the lead identification process of drug discovery and design. Many clustering methods have been used for chemical databases, but there is no clustering method that can obtain the best results under all circumstances. However, little attention has been focused on the use of combination methods for chemical structure clustering, which is known as consensus clustering. Recently, consensus clustering has been used in many areas including bioinformatics, machine learning and information theory. This process can improve the robustness, stability, consistency and novelty of clustering. For chemical databases, different consensus clustering methods have been used including the co-association matrix-based, graph-based, hypergraph-based and voting-based methods. In this paper, a weighted cumulative voting-based aggregation algorithm (W-CVAA) was developed. The MDL Drug Data Report (MDDR) benchmark chemical dataset was used in the experiments and represented by the AlogP and ECPF_4 descriptors. The results from the clustering methods were evaluated by the ability of the clustering to separate biologically active molecules in each cluster from inactive ones using different criteria, and the effectiveness of the consensus clustering was compared to that of Ward's method, which is the current standard clustering method in chemoinformatics. This study indicated that weighted voting-based consensus clustering can overcome the limitations of the existing voting-based methods and improve the effectiveness of combining multiple clusterings of chemical structures.
  8. Praveena SM, Ahmed A, Radojevic M, Abdullah MH, Aris AZ
    Bull Environ Contam Toxicol, 2008 Jul;81(1):52-6.
    PMID: 18506379 DOI: 10.1007/s00128-008-9460-3
    Spatial variations in estuarine intertidal sediment have been often related to such environmental variables as salinity, sediment types, heavy metals and base cations. However, there have been few attempts to investigate the difference condition between high and low tides relationships and to predict their likely responses in an estuarine environment. This paper investigates the linkages between environmental variables and tides of estuarine intertidal sediment in order to provide a basis for describing the effect of tides in the Mengkabong lagoon, Sabah. Multivariate statistical technique, principal components analysis (PCA) was employed to better interpret information about the sediment and its controlling factors in the intertidal zone. The calculation of Geoaccumulation Index (I(geo)) suggests the Mengkabong mangrove sediments are having background concentrations for Al, Cu, Fe, and Zn and unpolluted for Pb. Extra efforts should therefore pay attention to understand the mechanisms and quantification of different pathways of exchange within and between intertidal zones.
  9. Alkarkhi AF, Ismail N, Ahmed A, Easa Am
    Environ Monit Assess, 2009 Jun;153(1-4):179-85.
    PMID: 18504644 DOI: 10.1007/s10661-008-0347-x
    Statistical analysis of heavy metal concentrations in sediment was studied to understand the interrelationship between different parameters and also to identify probable source component in order to explain the pollution status of selected estuaries. Concentrations of heavy metals (Cu, Zn, Cd, Fe, Pb, Cr, Hg and Mn) were analyzed in sediments from Juru and Jejawi Estuaries in Malaysia with ten sampling points of each estuary. The results of multivariate statistical techniques showed that the two regions have different characteristics in terms of heavy metals selected and indicates that each region receives pollution from different sources. The results also showed that Fe, Mn, Cd, Hg, and Cu are responsible for large spatial variations explaining 51.15% of the total variance, whilst Zn and Pb explain only 18.93 of the total variance. This study illustrates the usefulness of multivariate statistical techniques for evaluation and interpretation of large complex data sets to get better information about the heavy metal concentrations and design of monitoring network.
  10. Masood I, Tahir MJ, Naeem A, Shrateh ON, Ahmed A
    Trop Med Health, 2023 Nov 14;51(1):62.
    PMID: 37957782 DOI: 10.1186/s41182-023-00559-z
    Congo virus, or Crimean-Congo hemorrhagic fever (CCHF), is a tick-borne disease caused by a single-stranded RNA virus (genus nairovirus, Bunyaviridae family). It spreads through infected ticks' bites or contact with viremic individuals or livestock. Factors supporting its spread include hot, humid climates, limited pesticide use, poor animal control, inadequate irrigation during monsoons, and vector control deficiencies. Nosocomial transmission in under-resourced hospitals poses a threat to healthcare workers. Decades of CCHF cases persist in Pakistan due to these factors, with six deaths reported by June 2023. To combat the epidemic, Pakistan should raise awareness, improve irrigation, establish surveillance systems, and implement livestock quarantine and vaccination.
  11. Arif S, Taweekun J, Ali HM, Ahmed A, Bhutto AA
    Heliyon, 2023 Nov;9(11):e21426.
    PMID: 38027710 DOI: 10.1016/j.heliyon.2023.e21426
    The use of renewable energy resources for off-grid electricity production has gained more importance in recent decades for meeting the energy needs of remote areas, even with limited resources. This research aims to provide an optimized and cost-effective approach for generating electricity in rural areas. By using current methodology, a stand alone energy source of PV is designed for development of NZE village. Solar irradiance of the selected location is 6.16 kWh/m2/day while the estimated electric load data for whole village is 64.259 kWh. Electric load and solar irradiance of the loaction is used in the Hybrid Optimization Model for Electric Renewable (HOMER) to design and analyze the techno-economic feasibility of the stand alone PV system to meet the load requirements. The study obtained the total Net Present Cost (NPC) of $0.511 M and the Cost Of Electricity (COE) is 2.26$/unit through the HOMER analysis, which is further refined by performing sensitivity analysis using parameters such as PV panel price, battery price, solar irradiance, variations in electric load and discount rates. According to the results, system is feasibile by annual electricity production of 30,078 kWh with initial capital investment of $0.434 M. This analysis compared the system performance and showed that it is economically and technically viable to meet the complete electricity needs of the village with a payback period of 7.2 years. Research can be utilized for policy making and implementation of NZE approach in remote areas by the government.
  12. Raees F, Harun A, Ahmed A, Deris ZZ
    Malays J Med Sci, 2023 Oct;30(5):7-22.
    PMID: 37928784 DOI: 10.21315/mjms2023.30.5.2
    Bacteriophages were discovered in early 20th century. However, the interest in bacteriophage research was reduced with the discovery of antibiotics. With the increasing number of infections due to multidrug-resistant (MDR) organisms, the potential usefulness of bacteriophages as therapeutic agents has been re-evaluated. In this review, we found that more than 30 lytic bacteriophages that infect Acinetobacter species have been characterised. These are mainly members of Caudovirales, with genome sizes ranging from 31 kb to 234 kb and G+C contents ranging from 33.5% to 45.5%. The host range can be as low as < 10% of all tested Acinetobacter strains. Fourteen published murine trials indicated positive outcomes in bacteriophage-treated groups. Only two case reports were pertaining to the use of bacteriophages in the treatment of Acinetobacter infections in humans; in both cases, the infections were resolved with bacteriophage therapy. The use of bacteriophages has been associated with reduced Acinetobacter burden in the environment, as shown in two studies. The major limitation of bacteriophage therapy is its highly selective host strain. In conclusion, the potential usefulness of bacteriophage therapy for the treatment of MDR Acinetobacter species has been documented only in limited studies and more research is needed prior to its extensive use in clinical practice.
  13. Eltrafi A, Shrestha S, Ahmed A, Mistry H, Paudyal V, Khanal S
    Health Econ Rev, 2023 Sep 01;13(1):43.
    PMID: 37656228 DOI: 10.1186/s13561-023-00459-2
    BACKGROUND: Chronic migraine (CM) is a significant neurological condition affecting a substantial portion of the global population. The economic burden of CM includes both direct healthcare costs and indirect costs resulting from productivity losses and intangible impacts on patients' quality of life. However, there is limited research that comprehensively evaluates all cost components associated with CM, highlighting the need for a systematic review.

    METHODS: We conducted a systematic literature search in databases including MEDLINE, Embase, and CINAHL to identify studies estimating the cost of illness of chronic migraines. The search was restricted to English language articles published from inception to October 2021, and only findings from Organisation for Economic Co-operation and Development (OECD) countries were included. Methodology features and key findings were extracted from the studies, and reported costs were converted to GBP for cross-country comparisons.

    RESULTS: Thirteen cost-of-illness studies on CM from various OECD countries were included in this review. The studies demonstrated substantial variations in monetary estimates, but consistently highlighted the considerable economic burden of CM. Direct costs, particularly hospitalisation and medication expenses, were identified as the highest contributors. However, indirect costs, such as productivity losses due to absenteeism and presenteeism, were often underexplored in the reviewed studies. Additionally, intangible costs related to emotional and social impacts on patients were largely overlooked.

    CONCLUSION: Chronic migraine imposes a significant economic burden on individuals, healthcare systems, and society. Policymakers and healthcare stakeholders should consider both direct and indirect cost components, as well as intangible costs, in developing targeted strategies for effective CM management and resource allocation. Further research focusing on comprehensive cost assessments and sensitivity analyses is needed to enhance the understanding of CM's economic implications and inform evidence-based healthcare policy decisions. Addressing these research gaps can alleviate the economic burden of CM and improve patient outcomes.

  14. Tanveer M, Tahir AH, Iqbal M, Aslam F, Ahmed A
    Brain Behav, 2023 Jul 29.
    PMID: 37515419 DOI: 10.1002/brb3.3127
    INTRODUCTION: The primary purpose of this study was to determine adherence and health-related quality of life (HRQoL) in PWE. Secondary aims were to assess association between adherence and HRQoL and determine predictors of HRQoL in PWE in Pakistan.

    METHODS: A descriptive cross-sectional study was conducted among PWE receiving treatment from two tertiary care hospitals of Pakistan. The HRQoL and adherence were assessed with Urdu versions of Quality of Life in Epilepsy-31 (QOLIE-31), and Medication Adherence Rating Scale (MARS). Relationship between HRQoL and adherence was assessed by Pearson's product-moment correlation coefficient. Forced entry multiple linear models were used to determine relationship of independent variables with HRQoL.

    RESULTS: 219 PWE with a mean (±standard deviation) age, 34.18 (± 13.710) years, participated in this study. The overall weighted mean HRQoL score was (51.60 ± 17.10), and mean score for adherence was 6.17 (± 2.31). There was significant association between adherence and HRQoL in PWE (Pearson's correlation = 0.820-0.930; p ≤ .0001). Multiple linear regression found adherence (B = 16.8; p ≤ .0001), male gender (B = 10.0; p = .001), employment status (employed: B = 7.50; p = .030), level of education (Tertiary: B = 0.910; p = .010), duration of epilepsy (>10 years: B = -0.700; p ≤ .0001), and age (≥46 years: B = -0.680; p ≤ .0001), and ASM therapy (polypharmacy: B = 0.430; p = .010) as independent predictors of HRQoL in PWE from Pakistan.

    CONCLUSIONS: The findings suggest PWE from our center have suboptimal adherence which affects HRQoL. Independent factors such as male gender, employment status and duration of epilepsy are predictors of HRQoL.

  15. Eltrafi A, Shrestha S, Ahmed A, Mistry H, Paudyal V, Khanal S
    Health Econ Rev, 2023 Oct 25;13(1):49.
    PMID: 37878082 DOI: 10.1186/s13561-023-00461-8
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