ASIF IQBAL | American International University-Bangladesh (original) (raw)
Papers by ASIF IQBAL
The Journal of biological chemistry, Jan 4, 2016
Parasitic nematodes manufacture various carbohydrate linked phosphorylcholine (PCh)-containing mo... more Parasitic nematodes manufacture various carbohydrate linked phosphorylcholine (PCh)-containing molecules including ES-62, a protein with an N-linked glycan terminally substituted with PCh. The PCh component is biologically important, as it is required for immunomodulatory effects. We showed that most ES-62 was bound to a single protein, C-reactive protein in normal human serum, displaying calcium-dependent high avidity interaction and ability to form large complexes. Unexpectedly, CRP binding to ES-62 failed to efficiently activate complement as far as the C3 convertase stage in comparison with PCh-BSA and PCh-containing Streptocococcus pneumoniae cell wall polysaccharide. C1q capture assays demonstrated ES-62-CRP-C1q interaction in serum. The three ligands all activated C1 and generated C4b to similar extents. However C2a active site was not generated following ES-62 binding to CRP demonstrating that C2 cleavage was far less efficient for ES-62 containing complexes. We proposed tha...
Clinical Epidemiology and Global Health, 2015
Archives of biochemistry and biophysics, 2014
Protein disulfide isomerase (PDI) is a dithiol-disulfide oxidoreductase that has essential roles ... more Protein disulfide isomerase (PDI) is a dithiol-disulfide oxidoreductase that has essential roles in redox protein folding. PDI has been associated with protective roles against protein aggregation, a hallmark of neurodegenerative diseases. Intriguingly, PDI has been detected in the protein inclusions found in the central nervous system of patients of neurodegenerative diseases. Oxidized proteins are also consistently detected in such patients, but the agents that promote these oxidations remain undefined. A potential trigger of protein oxidation is the bicarbonate-dependent peroxidase activity of the human enzyme superoxide dismutase 1 (hSOD1). Therefore, we examined the effects of this activity on PDI structure and activity. The results showed that PDI was oxidized to radicals that lead to PDI inactivation and aggregation. The aggregates are huge and apparently produced by covalent cross-links. Spin trapping experiments coupled with MS analysis indicated that at least 3 residues of...
IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society, 2013
ABSTRACT Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable ener... more ABSTRACT Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable energy based applications such as electric vehicles (EVs), for the implementation of vehicle-to-grid (V2G) systems. Recently, more efforts have been made by researchers to improve both efficiency and reliability of renewable energy systems to further enhance their economical sustainability. This paper presents a comparative reliability study between a typical BDIPT system and an individually controlled segmented BDIPT system. Steady state thermal simulation results are provided for different output power levels for a 1.5 kW BDIPT system in a MATLAB/Simulink environment. Reliability parameters such as failure rate and mean time between failures (MTBF) are compared between the two systems. A nonlinear programming (NP) model is developed for optimizing charging schedule for a stationery EV. A case study of EV optimum charging is provided for a 24 hours period indicating minimum cost and higher reliability.
The Journal of biological chemistry, Jan 31, 2014
The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in... more The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in the amyotrophic lateral sclerosis (ALS) pathology is an attractive hypothesis to explore based on several lines of evidence. Among them, the remarkable stability of hSOD1(WT) and several of its ALS-associated mutants suggests that hSOD1 oxidation may precede its conversion to the unfolded and aggregated forms found in ALS patients. The bicarbonate-dependent peroxidase activity of hSOD1 causes oxidation of its own solvent-exposed Trp(32) residue. The resulting products are apparently different from those produced in the absence of bicarbonate and are most likely specific for simian SOD1s, which contain the Trp(32) residue. The aims of this work were to examine whether the bicarbonate-dependent peroxidase activity of hSOD1 (hSOD1(WT) and hSOD1(G93A) mutant) triggers aggregation of the enzyme and to comprehend the role of the Trp(32) residue in the process. The results showed that Trp(32) ...
Proceedings of the National Academy of Sciences, 2008
Background: Mental health and mental illness are often overlooked in the management of patients i... more Background: Mental health and mental illness are often overlooked in the management of patients in our health services. Depression is a common mental disorder worldwide. Recognising and managing mental illnesses such as depression by primary health care providers (PHCPs) is crucial. This study describes the knowledge, attitudes and practices (KAP) of PHCPs regarding depression in Fako Division. Methods: A cross-sectional study was conducted among PHCPs (general practitioners, nurses, pharmacy attendants and social workers) in public-owned health facilities in the four health districts in Fako Division. Participants were selected by a consecutive convenience sampling. A structured questionnaire including the Depression Attitude Questionnaire (DAQ) was used to collect information about their socio-demographic characteristics, professional qualifications and KAP about depression. Results: The survey had a response rate of 56.7%. Most of the 226 participants (92.9%) were aware that depression needs medical intervention. Only 1.8% knew a standard tool used to diagnose depression. Two-thirds agreed that majority of the cases of depression encountered originate from recent misfortune. About 66% felt uncomfortable working with depressed patients. Also, 45.1% of PHCPs did not know if psychotropic drugs were available at pharmacies within their health area. Very few (15.2%) reported to have prescribed psychotropic drugs. Less than half (49.1%) of the participants had prior formal training in mental health. Conclusion: PHCPs in Fako Division tend to have limited knowledge and poor attitudes regarding depression. Practices towards diagnosis and management of depression tend to be inadequate. There is an urgent need to train PHCPs in mental health in general and depression diagnosis and management in particular.
The Journal of biological chemistry, Jan 4, 2016
Parasitic nematodes manufacture various carbohydrate linked phosphorylcholine (PCh)-containing mo... more Parasitic nematodes manufacture various carbohydrate linked phosphorylcholine (PCh)-containing molecules including ES-62, a protein with an N-linked glycan terminally substituted with PCh. The PCh component is biologically important, as it is required for immunomodulatory effects. We showed that most ES-62 was bound to a single protein, C-reactive protein in normal human serum, displaying calcium-dependent high avidity interaction and ability to form large complexes. Unexpectedly, CRP binding to ES-62 failed to efficiently activate complement as far as the C3 convertase stage in comparison with PCh-BSA and PCh-containing Streptocococcus pneumoniae cell wall polysaccharide. C1q capture assays demonstrated ES-62-CRP-C1q interaction in serum. The three ligands all activated C1 and generated C4b to similar extents. However C2a active site was not generated following ES-62 binding to CRP demonstrating that C2 cleavage was far less efficient for ES-62 containing complexes. We proposed tha...
Clinical Epidemiology and Global Health, 2015
Archives of biochemistry and biophysics, 2014
Protein disulfide isomerase (PDI) is a dithiol-disulfide oxidoreductase that has essential roles ... more Protein disulfide isomerase (PDI) is a dithiol-disulfide oxidoreductase that has essential roles in redox protein folding. PDI has been associated with protective roles against protein aggregation, a hallmark of neurodegenerative diseases. Intriguingly, PDI has been detected in the protein inclusions found in the central nervous system of patients of neurodegenerative diseases. Oxidized proteins are also consistently detected in such patients, but the agents that promote these oxidations remain undefined. A potential trigger of protein oxidation is the bicarbonate-dependent peroxidase activity of the human enzyme superoxide dismutase 1 (hSOD1). Therefore, we examined the effects of this activity on PDI structure and activity. The results showed that PDI was oxidized to radicals that lead to PDI inactivation and aggregation. The aggregates are huge and apparently produced by covalent cross-links. Spin trapping experiments coupled with MS analysis indicated that at least 3 residues of...
IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society, 2013
ABSTRACT Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable ener... more ABSTRACT Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable energy based applications such as electric vehicles (EVs), for the implementation of vehicle-to-grid (V2G) systems. Recently, more efforts have been made by researchers to improve both efficiency and reliability of renewable energy systems to further enhance their economical sustainability. This paper presents a comparative reliability study between a typical BDIPT system and an individually controlled segmented BDIPT system. Steady state thermal simulation results are provided for different output power levels for a 1.5 kW BDIPT system in a MATLAB/Simulink environment. Reliability parameters such as failure rate and mean time between failures (MTBF) are compared between the two systems. A nonlinear programming (NP) model is developed for optimizing charging schedule for a stationery EV. A case study of EV optimum charging is provided for a 24 hours period indicating minimum cost and higher reliability.
The Journal of biological chemistry, Jan 31, 2014
The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in... more The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in the amyotrophic lateral sclerosis (ALS) pathology is an attractive hypothesis to explore based on several lines of evidence. Among them, the remarkable stability of hSOD1(WT) and several of its ALS-associated mutants suggests that hSOD1 oxidation may precede its conversion to the unfolded and aggregated forms found in ALS patients. The bicarbonate-dependent peroxidase activity of hSOD1 causes oxidation of its own solvent-exposed Trp(32) residue. The resulting products are apparently different from those produced in the absence of bicarbonate and are most likely specific for simian SOD1s, which contain the Trp(32) residue. The aims of this work were to examine whether the bicarbonate-dependent peroxidase activity of hSOD1 (hSOD1(WT) and hSOD1(G93A) mutant) triggers aggregation of the enzyme and to comprehend the role of the Trp(32) residue in the process. The results showed that Trp(32) ...
Proceedings of the National Academy of Sciences, 2008
Background: Mental health and mental illness are often overlooked in the management of patients i... more Background: Mental health and mental illness are often overlooked in the management of patients in our health services. Depression is a common mental disorder worldwide. Recognising and managing mental illnesses such as depression by primary health care providers (PHCPs) is crucial. This study describes the knowledge, attitudes and practices (KAP) of PHCPs regarding depression in Fako Division. Methods: A cross-sectional study was conducted among PHCPs (general practitioners, nurses, pharmacy attendants and social workers) in public-owned health facilities in the four health districts in Fako Division. Participants were selected by a consecutive convenience sampling. A structured questionnaire including the Depression Attitude Questionnaire (DAQ) was used to collect information about their socio-demographic characteristics, professional qualifications and KAP about depression. Results: The survey had a response rate of 56.7%. Most of the 226 participants (92.9%) were aware that depression needs medical intervention. Only 1.8% knew a standard tool used to diagnose depression. Two-thirds agreed that majority of the cases of depression encountered originate from recent misfortune. About 66% felt uncomfortable working with depressed patients. Also, 45.1% of PHCPs did not know if psychotropic drugs were available at pharmacies within their health area. Very few (15.2%) reported to have prescribed psychotropic drugs. Less than half (49.1%) of the participants had prior formal training in mental health. Conclusion: PHCPs in Fako Division tend to have limited knowledge and poor attitudes regarding depression. Practices towards diagnosis and management of depression tend to be inadequate. There is an urgent need to train PHCPs in mental health in general and depression diagnosis and management in particular.