243 results on '"Sarmah S"'
Search Results
102. Long-term follow up with gait analysis after anterior cruciate reconstruction (ACL) in patients aged over 50 years.
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Sarmah, S., Fayad, T., Patel, R., and Haddad, F. S.
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ACCELEROMETERS , *ANTERIOR cruciate ligament surgery , *DIAGNOSIS , *ENERGY metabolism , *GAIT in humans , *RADIOGRAPHY , *T-test (Statistics) , *CONTROL groups , *DATA analysis software , *FUNCTIONAL assessment , *DESCRIPTIVE statistics - Abstract
Introduction: the aim of this study was to assess stability, functional outcome and gait parameters i.e. cadence, speed, stride length, single and double leg support (SLS/DLS) and energy expenditure (EE) to assess functional outcome in middle-aged group of patients with ACL reconstruction. Materials and methods: we analyzed gait parameters in 40 patients aged over 50 years and older with the IDEEA accelerometer as part of our long term follow up assessment. Speed, cadence, stride length and SLS/DLS were compared with the non-operative leg of the same patient and EE was compared with 25 healthy volunteers (control group) who performed the same routine. Knee laxity was evaluated by KT 1000 arthrometer and compared between the operated and non-operated leg. Weight-bearing antero-posterior, lateral, Skyline view and Rosenberg radiographs were taken to compare with pre-operative views and elicit progressive degenerative changes. IKDC, Tegner-Lysholm and SF 12 scores were collected simultaneously for functional assessment. Results: the mean age of the patients and the control groups were 54.7 years and 29.4 years respectively and the mean follow up period 3.8 years (2.4-6 years). We found no statistically significant difference between cadence, stride length, speed and SLS/DLS between the operated and non-operated leg; p. 0.36, p. 0.62, p. 0.81 and p. 0.06 respectively on unpaired t test. Similarly, no difference was found comparing the overall EE during the gait cycle between the patients and the control group (p. 0.55). The mean IKDC, Tegner-Lysholm and SF 12 functional score were 86.1 and 87.5 and 55.7/49.5 (PCS/MCS) respectively. 11 patients (27.5%) had grade I changes on post-operative radiographs in accordance with IKDC guidelines. KT 1000 test showed no statistically significant difference between the mean values comparing the operated knee to the non-operated one (p.0.85) on unpaired t test. Conclusion: we found good functional outcome post ACL reconstruction in middle-aged patients. Our results also show that ACL reconstruction surgery is beneficial in patients with high activity level irrespective of their age. [ABSTRACT FROM AUTHOR]
- Published
- 2012
103. Coordination and price competition in duopoly distribution channels.
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Sinha, Santanu and Sarmah, S. P.
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ECONOMIC competition ,PRICES ,RETAIL industry ,MARKETING channels ,PRODUCT differentiation - Abstract
This paper investigates the issues of price competition and channel coordination when two different sellers compete to sell differentiated products through their exclusive retailers. The demand of a product depends not only on its own price, but also on the price of the other. Mathematical models have been developed to analyse the coordination scenarios under different channel structures, such as when (1) both the channels are decentralised, (2) one of the channels is decentralised while the other one is centralised, (3) both the channels are centralised and (4) global coordination exists. It is observed that in some cases, competition serves the firms better than perfect coordination. Furthermore, it is shown that efficiency of competition and coordination exclusively depends on the product type, degree of product differentiation, channel structure and the number of distribution channels in the market. [ABSTRACT FROM AUTHOR]
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- 2009
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104. A note on herbicidal control of weeds in summer soybean
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Pathak, A. K., Borgohain, M., and Sarmah, S. C.
- Published
- 1986
105. Another Swim in the Extensive Pool of Zebrafish Research.
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Marrs JA and Sarmah S
- Abstract
The zebrafish has gained utility in modeling biomedical phenomena for discovery research [...].
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- 2024
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106. PCy 3 -assisted Ag(I)-catalyzed click reaction for regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles at room temperature.
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Hazarika R, Dutta S, Sarmah S, Hazarika PK, Singh K, Kumar A, Sarma B, and Sarma D
- Abstract
An approach towards Cu-free click chemistry has been developed in this work. Silver-catalyzed PCy
3 -ligand-assisted synthesis of 1,4-disubstituted 1,2,3-triazoles at room temperature has been developed. Regioselectivity of the reaction was confirmed from the results of single-crystal X-ray diffraction (SC-XRD) of one of the products. SC-XRD of ex situ -generated Ag-PCy3 complex helped us propose a plausible mechanism for the reaction. This reaction was indicated to exhibit a catalytic activity level similar to that for the in situ -generated complex. The methodology was found to work well with benzyl azides, phenyl azides, terminal alkynes and internal alkynes in aqueous medium. The one-pot three-component reaction leading to 1,2,3-triazole synthesis also proceeded well.- Published
- 2024
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107. Unleashing the binding interaction of chrysin-Cu(II) complex with the biomacromolecular targets: further studies of cell cytotoxicity and radical scavenging properties.
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Sarmah S, Konthoujam I, Prakash V, Aguan K, and Singha Roy A
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Flavonoids are significant dietary components and have ability to coordinate with metal ions to produce novel drug discovery leads that are superior to those of the parent flavonoids. Here, in this report, we have synthesized chrysin-Cu(II) complex (as per reported article) and characterized it further with different analytical techniques. The synthesized complex was evaluated for radical scavenging and cell cytotoxicity studies where it exhibited enhanced activity as compared to bare chrysin. The interaction studies of the complex with ct-DNA ( K
b ⁓ 105 M-1 ), human serum albumin (HSA) and ovalbumin ( Kb ⁓ 104 M-1 ) were evaluated using multi-spectroscopic and molecular docking studies. Groove binding mode with ct-DNA was observed as confirmed from competitive displacement studies, viscosity measurement, melting temperature estimation and docking analyses. The complex exhibited comparatively higher affinity towards ct-DNA which indicated it efficient transportation by the carrier proteins and controlled release in the target DNA.Communicated by Ramaswamy H. Sarma.- Published
- 2024
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108. Efficacy of nonsurgical periodontal therapy affecting salivary biomarkers in non-diabetic and type 2 diabetic periodontitis patients. An observational study.
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Hungund SA, Desai VB, Shah M, Shekar MK, Deka A, and Sarmah S
- Abstract
Objectives: To assess the effects of non-surgical periodontal therapy on salivary biomarkers in non-diabetic and type 2 diabetic periodontitis patients and to investigate if saliva may be used to monitor glucose levels in type 2 diabetes., Material and Methods: 250 participants with chronic generalized periodontitis aged 35-70 years were divided into two groups: test group with type 2 diabetes (125 subjects with 64 males & 61 females) and control group with non-diabetic (125 subjects with 83 males & 42 females). Participants received non-surgical periodontal treatment. Pre-NSPT and 6-week post-NSPT saliva glucose, amylase, total protein, and C-reactive protein (CRP) levels were measured. Intergroup correlations were assessed using Karl Pearson's correlation coefficient and paired t -test., Results: Non-surgical periodontal therapy significantly decreased CRP (p < 0.05) in diabetics and non-diabetics. CRP mean values changes from baseline 1.79 to post op 1.5 and baseline 1.5 to post-op 1.24 in males and females of test group, respectively. In control group males and females, mean values change from baseline 1.48 to post-op 1.42 and 1.499 to 1.40. Other parameters Glucose, amylase & total protein showed improvement in the level, but statistically non-significant (p > 0.05). Salivary glucose levels corresponded favorably with HbA1C levels., Conclusion: In individuals with type 2 diabetes and non-diabetic generalized chronic periodontitis, non-surgical periodontal therapy may play a role in lowering the level of significant salivary biomarkers. Saliva can be utilized as a non-invasive approach for monitoring glucose levels in people with type 2 diabetes and chronic periodontitis., Competing Interests: The authors warrant that they do not have any competing interests to declare., (© 2023 Published by Elsevier B.V. on behalf of Craniofacial Research Foundation.)
- Published
- 2023
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109. Deciphering the interactions of phytochemicals with ovalbumin, the major food allergen from egg white: spectroscopic and computational studies.
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Sarmah S, Hazarika U, Das SM, Quraishi S, Bhatta A, Belwal VK, Jha AN, and Singha Roy A
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- Humans, Ovalbumin chemistry, Ovalbumin metabolism, Immunoglobulin E chemistry, Immunoglobulin E metabolism, Allergens chemistry, Protein Binding, Molecular Docking Simulation, Egg White, Egg Hypersensitivity
- Abstract
Ovalbumin (OVA), the major component of egg white, has been used as a model carrier protein to study the interaction of four bioactive phytochemicals 6-hydroxyflavone, chrysin, naringin, and naringenin. A static quenching mechanism was primarily associated with the complexation of the flavonoids with OVA. Hydrophobic forces play a major part in the stability of the complexes. The structural changes within the protein in response to flavonoid binding revealed a decrease in OVA's α-helical content. The hypothesized binding site for flavonoids in OVA overlaps with one or more immunoglobulin E-binding epitopes that may have some effect in the immunoglobulin E response pathway. The flavonoids remain in the same binding site throughout the simulation time and impart protein stability by forming different noncovalent interactions. This study presents comprehensive information about the interaction of the flavonoids with OVA and the associated structural variations after the binding, which might help researchers better comprehend similar medication pharmacodynamics and provide critical information for future therapeutic development., (© 2022 John Wiley & Sons Ltd.)
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- 2022
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110. Elf3 deficiency during zebrafish development alters extracellular matrix organization and disrupts tissue morphogenesis.
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Sarmah S, Hawkins MR, Manikandan P, Farrell M, and Marrs JA
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- Animals, Humans, DNA-Binding Proteins genetics, Gene Expression Regulation, Developmental, Proto-Oncogene Proteins c-ets genetics, Proto-Oncogene Proteins c-ets metabolism, Transcription Factors metabolism, Extracellular Matrix metabolism, Morphogenesis genetics, Zebrafish metabolism, Zebrafish Proteins genetics, Zebrafish Proteins metabolism
- Abstract
E26 transformation specific (ETS) family transcription factors are expressed during embryogenesis and are involved in various cellular processes such as proliferation, migration, differentiation, angiogenesis, apoptosis, and survival of cellular lineages to ensure appropriate development. Dysregulated expression of many of the ETS family members is detected in different cancers. The human ELF3, a member of the ETS family of transcription factors, plays a role in the induction and progression of human cancers is well studied. However, little is known about the role of ELF3 in early development. Here, the zebrafish elf3 was cloned, and its expression was analyzed during zebrafish development. Zebrafish elf3 is maternally deposited. At different developmental stages, elf3 expression was detected in different tissue, mainly neural tissues, endoderm-derived tissues, cartilage, heart, pronephric duct, blood vessels, and notochord. The expression levels were high at the tissue boundaries. Elf3 loss-of-function consequences were examined by using translation blocking antisense morpholino oligonucleotides, and effects were validated using CRISPR/Cas9 knockdown. Elf3-knockdown produced short and bent larvae with notochord, craniofacial cartilage, and fin defects. The extracellular matrix (ECM) in the fin and notochord was disorganized. Neural defects were also observed. Optic nerve fasciculation (bundling) and arborization in the optic tectum were defective in Elf3-morphants, and fragmentation of spinal motor neurons were evident. Dysregulation of genes encoding ECM proteins and matrix metalloprotease (MMP) and disorganization of ECM may play a role in the observed defects in Elf3 morphants. We conclude that zebrafish Elf3 is required for epidermal, mesenchymal, and neural tissue development., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Sarmah et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2022
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111. Ethanol Effects on Early Developmental Stages Studied Using the Zebrafish.
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Manikandan P, Sarmah S, and Marrs JA
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Fetal alcohol spectrum disorder (FASD) results from prenatal ethanol exposure. The zebrafish ( Danio rerio ) is an outstanding in vivo FASD model. Early development produced the three germ layers and embryonic axes patterning. A critical pluripotency transcriptional gene circuit of sox2 , pou5f1 ( oct4 ; recently renamed pou5f3 ), and nanog maintain potency and self-renewal. Ethanol affects sox2 expression, which functions with pou5f1 to control target gene transcription. Various genes, like elf3 , may interact and regulate sox2 , and elf3 knockdown affects early development. Downstream of the pluripotency transcriptional circuit, developmental signaling activities regulate morphogenetic cell movements and lineage specification. These activities are also affected by ethanol exposure. Hedgehog signaling is a critical developmental signaling pathway that controls numerous developmental events, including neural axis specification. Sonic hedgehog activities are affected by embryonic ethanol exposure. Activation of sonic hedgehog expression is controlled by TGF-ß family members, Nodal and Bmp, during dorsoventral (DV) embryonic axis establishment. Ethanol may perturb TGF-ß family receptors and signaling activities, including the sonic hedgehog pathway. Significantly, experiments show that activation of sonic hedgehog signaling rescues some embryonic ethanol exposure effects. More research is needed to understand how ethanol affects early developmental signaling and morphogenesis.
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- 2022
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112. Towards a sustainable organic waste supply chain: A comparison of centralized and decentralized systems.
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Rathore P, Chakraborty S, Gupta M, and Sarmah SP
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- Cities, Solid Waste analysis, Composting, Refuse Disposal methods, Waste Management methods
- Abstract
Proper disposal of Municipal Solid (MSW) waste is an important issue as it causes land, air, and water pollution. Organic MSW provides a habitat environment to insects and often it spreads dangerous diseases. Major reasons identified behind this as the non-separation of MSW at the source and lack of facilities (bins) in the appropriate place for collection of wastes. The present study has proposed an integrated three-stage model to provide a solution to the problem of (i) allocation of the bin for waste collection, (ii) allocation and comparison of centralized and decentralized composting plants, and finally, (iii) vehicle routing for waste collection. The proposed generic model is applied to an Indian city, Bilaspur located in the state of Chhattisgarh. From the results, it is observed that the first stage model provides an optimal number of bins required and allocation of it at minimum cost. Taking it as input for the second stage model, it identifies the best locations for centralized and decentralized composting plants. The result also reveals that decentralized composting plants are more economical than centralized plants. Finally, the third stage of the model identifies the vehicle routing for the waste collection considering both centralized and decentralized plants to minimize the cost. Further, sensitivity analysis is carried out on collection rate and participation percentage parameters to draw additional insights for better management of MSW., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2022
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113. Multispectroscopic studies on the molecular interactions between bovine γ-globulin and borohydride-capped silver nanoparticles.
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Sharma A, Sarmah S, Roy AS, and Ghosh KS
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- Animals, Borohydrides, Cattle, Circular Dichroism, Citrates, Spectrometry, Fluorescence methods, gamma-Globulins, Metal Nanoparticles chemistry, Silver chemistry
- Abstract
Interactions between bovine γ-globulin (BGG) and borohydride-capped silver nanoparticles (BAgNPs) were studied using dynamic light scattering (DLS) and spectroscopic techniques such as UV-vis spectroscopy, fluorescence, and circular dichroism. The results were compared with earlier reported interactions between γ-globulin and citrate-coated AgNPs (CAgNPs). BAgNPs were synthesized and characterized. Irrespective of the coating on AgNPs, nanoparticles had formed ground-state complexes with the protein. CAgNPs, as well as BAgNPs had caused static quenching of tryptophan (Trp) fluorescence of the protein. The change in the capping agent from citrate to borohydride weakened the binding of nanoparticles with the protein. But the same change in capping agent had increased the fluorescence quenching efficiency of AgNPs. Hydrogen bonding and van der Waals interactions were involved in BGG-BAgNPs complex similar to the CAgNPs complex with γ-globulin. Polarity of the Trp microenvironment in BGG was not altered using BAgNPs as opposed to CAgNPs, as supported using synchronous and three-dimensional fluorescence. Resonance light scattering experiments also suggested nano-bio conjugation. Far-UV and near-UV circular dichroism (CD) spectra respectively pointed towards changes in the secondary and tertiary structure of BGG by BAgNPs, which was not observed for CAgNPs., (© 2022 John Wiley & Sons Ltd.)
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- 2022
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114. Mitigation of ribose and glyoxal induced glycation, AGEs formation and aggregation of human serum albumin by citrus fruit phytochemicals naringin and naringenin: An insight into their mechanism of action.
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Sarmah S, Goswami A, Kumar Belwal V, and Singha Roy A
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- Flavanones, Flavonoids metabolism, Glycation End Products, Advanced metabolism, Humans, Phytochemicals, Ribose, Serum Albumin, Human chemistry, Citrus metabolism, Glyoxal chemistry
- Abstract
Human serum albumin (HSA) being the most prevalent protein in the plasma is extremely vulnerable to glycation. Two flavonoids naringin and naringenin were tested for their effects on the glyoxal and ribose-induced glycation, advanced glycation end products (AGEs) and fibril formation of HSA. The inhibition of the formation of AGEs in the presence of both flavonoids demonstrated their antiglycating properties. The presence of fibrillar aggregates in the glyoxal and ribose modified HSA were also decreased by naringin and naringenin. The explanation for naringenin's stronger antiglycating potential than naringin was further investigated by examining their interactions with HSA. H-bonding and other non-covalent interactions with flavonoids stabilize HSA. Interactions of lysine and arginine residues with flavonoids may prevent the residues from getting modified during glycation process. Naringenin bind to both subdomains IIA and IIIA of HSA, protecting more residues than naringin, which only binds to subdomain IIA, may describe the higher inhibitory activity of naringenin., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2022
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115. A review on prevention of glycation of proteins: Potential therapeutic substances to mitigate the severity of diabetes complications.
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Sarmah S and Roy AS
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- Animals, Biological Products chemistry, Biological Products pharmacology, Biological Products therapeutic use, Diabetes Complications, Diabetes Mellitus metabolism, Disease Management, Disease Susceptibility, Glycation End Products, Advanced chemistry, Glycation End Products, Advanced metabolism, Humans, Plant Extracts chemistry, Plant Extracts pharmacology, Plant Extracts therapeutic use, Protein Aggregates drug effects, Protein Aggregation, Pathological drug therapy, Protein Binding drug effects, Protein Processing, Post-Translational drug effects, Protein Stability drug effects, Proteins chemistry, Structure-Activity Relationship, Glycosylation drug effects, Proteins metabolism
- Abstract
Non-enzymatic reaction involving carbonyl of reducing sugars and amino groups in proteins produces advanced glycation end products (AGEs). AGE accumulation in vivo is a crucial factor in the progression of metabolic and pathophysiological mechanisms like obesity, diabetes, coronary artery disease, neurological disorders, and chronic renal failure. The body's own defense mechanism, synthetic inhibitors, and natural inhibitors can all help to prevent the glycation of proteins. Synthetic inhibitors have the potential to suppress the glycation of proteins through a variety of pathways. They could avoid Amadori product development by tampering with the addition of sugars to the proteins. Besides which, the free radical scavenging and blocking crosslink formation could be another mechanism behind their anti-glycation properties. In comparison with synthetic substances, naturally occurring plant products have been found to be comparatively non-toxic, cheap, and usable in an ingestible form. This review gives a brief introduction of the Maillard reaction; formation, characterization and pathology related to AGEs, potential therapeutic approaches against glycation, natural and synthetic inhibitors of glycation and their probable mechanism of action. The scientific community could get benefit from the combined knowledge about important molecules, which will further guide to the design and development of new pharmaceutical compounds., (Copyright © 2021 Elsevier B.V. All rights reserved.)
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- 2022
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116. Modeling and identification of suitable motivational mechanism in the collection system of municipal solid waste supply chain.
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Rathore P and Sarmah SP
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- Models, Theoretical, Motivation, Solid Waste analysis, Refuse Disposal, Waste Management
- Abstract
Many studies have identified that incentive, subsidy, and reward-penalty mechanisms improve the collection rate of recyclables and end of life products. But there is a lack of studies mathematical models and analysis of these mechanisms in the context of municipal solid waste supply chain. Therefore, in this study, models have been formulated for municipal solid waste supply chain (profit) considering government and collectors' profit under incentive, subsidy, and reward-penalty mechanisms. The study has analysed the models against the non-separation and separation scenario of waste. A numerical analysis is performed and observed that: (i) separation of waste at source along with incentive, subsidy, and reward-penalty mechanisms scenario improve the collection rate by 17%, 23%, 30%, and 45% compared to non-separated MSW. (ii) Incentive, subsidy, and reward-penalty mechanisms increases the total supply chain profit by around 9%, -36% and 18%. (iii) reward-penalty mechanism performs better than incentive and subsidy mechanism by providing the high supply chain profit (18% and 85%) and collection rate (22% and 15%) comparatively. Further, sensitivity analysis carried out to understand the behaviour of the models against the key parameters. The study also develops interesting propositions and proved for a better understanding of the models. From results, some key managerial insights have been drawn and a few future scopes of the study are presented., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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117. An investigation into the identification of potential inhibitors of SARS-CoV-2 main protease using molecular docking study.
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Das S, Sarmah S, Lyndem S, and Singha Roy A
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- Antiviral Agents pharmacology, Humans, Molecular Docking Simulation, Peptide Hydrolases, Protease Inhibitors pharmacology, COVID-19, SARS-CoV-2
- Abstract
A new strain of a novel infectious disease affecting millions of people, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently been declared as a pandemic by the World Health Organization (WHO). Currently, several clinical trials are underway to identify specific drugs for the treatment of this novel virus. The inhibition of the SARS-CoV-2 main protease is necessary for the blockage of the viral replication. Here, in this study, we have utilized a blind molecular docking approach to identify the possible inhibitors of the SARS-CoV-2 main protease, by screening a total of 33 molecules which includes natural products, anti-virals, anti-fungals, anti-nematodes and anti-protozoals. All the studied molecules could bind to the active site of the SARS-CoV-2 protease (PDB: 6Y84), out of which rutin (a natural compound) has the highest inhibitor efficiency among the 33 molecules studied, followed by ritonavir (control drug), emetine (anti-protozoal), hesperidin (a natural compound), lopinavir (control drug) and indinavir (anti-viral drug). All the molecules, studied out here could bind near the crucial catalytic residues, HIS41 and CYS145 of the main protease, and the molecules were surrounded by other active site residues like MET49, GLY143, HIS163, HIS164, GLU166, PRO168, and GLN189. As this study is based on molecular docking, hence being particular about the results obtained, requires extensive wet-lab experimentation and clinical trials under in vitro as well as in vivo conditions.Communicated by Ramaswamy H. Sarma.
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- 2021
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118. The Genius of the Zebrafish Model: Insights on Development and Disease.
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Marrs JA and Sarmah S
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The zebrafish is an outstanding and inexpensive vertebrate model system for biomedical research [...].
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- 2021
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119. Zebrafish (Danio rerio) larvae show behavioral and embryonic development defects when exposed to opioids at embryo stage.
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Sales Cadena MR, Cadena PG, Watson MR, Sarmah S, Boehm Ii SL, and Marrs JA
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- Animals, Codeine toxicity, Larva drug effects, Larva growth & development, Morphine toxicity, Swimming, Zebrafish embryology, Analgesics, Opioid toxicity, Motor Activity drug effects
- Abstract
Opioid abuse continues to plague society, and in recent years, there has been an epidemic, leading to increased addiction and death. It is poorly understood how prenatal opioid use affects the lives of children. The aim of this work was to evaluate the effect of early embryonic codeine or morphine exposure in zebrafish (Danio rerio), examining gastrulation progression (epiboly), teratogenic effects, mortality and locomotor behavior response to light/dark cycles. Zebrafish embryos were exposed to codeine or morphine (designated C or M) at 1, 5 or 10 mg/L (designated 01, 05 or 10, respectively) from 3 to 24 h postfertilization (hpf) or from 3 to 48 hpf (designated -24 or - 48 for 1 or 2 days of exposure, respectively). The C10-24, C01-48, C05-48 and C10-48 groups showed significantly smaller eyes than control larvae at 7 days postfertilization (dpf). Locomotor behavior of control larvae in light/dark cycles showed greater swimming time and distance in dark cycles. Two-day codeine exposure produced strong effects, showing no significant response due to light/dark cycles in distance moved. Morphine exposed groups showed similar effects as observed in 2-day codeine exposed groups, showing less large movement activity and also no significant difference between inactive duration in response to light/dark cycles. In conclusion, we observed low teratogenic effects and mortality effects. Animals exposed to high levels and higher exposure times of opioids were hypoactive, relative to controls, in the dark period. Future studies will be needed to understand the neural defects producing behavior changes., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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120. Elucidation of molecular interactions between human γD-crystallin and quercetin, an inhibitor against tryptophan oxidation.
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Rana S, Sarmah S, Singha Roy A, and Ghosh KS
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- Energy Transfer, Humans, Oxidation-Reduction, Spectrometry, Fluorescence, Quercetin, Tryptophan metabolism
- Abstract
Different post-translational changes in eye lens crystallin proteins contribute towards the development of cataract. We have studied in vitro oxidative modification of tryptophan (Trp) residues of human γD-crystallin (HGD) towards formation of N-formylkynurenine (NFK) associated with cataractogenesis. This oxidation was found to be inhibited by quercetin at relatively low concentration. Interactions between quercetin and HGD were further studied using fluorescence techniques. Binding and quenching constants were determined as ∼10
4 M-1 . Static quenching of fluorescence due to HGD-quercetin complex formation at ground state was confirmed by finding excited state life time of Trp residues. Energy transfer occurred between the protein and quercetin. Hydrogen bonding and/or van der Waals interactions were involved between HGD and quercetin. Synchronous and three-dimensional fluorescence along with far-UV CD studies suggested no major conformational alterations occurred in HGD due to quercetin binding. Experimental observations were supported by the docking results.Communicated by Ramaswamy H. Sarma.- Published
- 2021
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121. Non-enzymatic glycation of human serum albumin modulates its binding efficacy towards bioactive flavonoid chrysin: A detailed study using multi-spectroscopic and computational methods.
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Sarmah S, Pahari S, Das S, Belwal VK, Jana M, and Singha Roy A
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- Binding Sites, Circular Dichroism, Humans, Molecular Docking Simulation, Protein Binding, Spectrometry, Fluorescence, Thermodynamics, Flavonoids, Serum Albumin, Human metabolism
- Abstract
The non-enzymatic glycation of plasma proteins by reducing sugars have important consequences on the conformational and functional properties of protein. The formation of advanced glycation end products (AGEs) is responsible for cell death and other pathological conditions. We have synthesized the glycated human serum albumin (gHSA) and characterized the same by using differential spectroscopic measurements. The aim of the present study is to determine the effect of glycation on the binding of human serum albumin (HSA) with bioactive flavonoid chrysin, which possesses anti-cancer, anti-inflammatory and anti-oxidant activities. The interaction of chrysin with HSA and gHSA was studied using multi-spectroscopic, molecular docking and molecular dynamics (MD) simulation techniques. Chrysin quenched the intrinsic fluorescence of both HSA and gHSA by static quenching mechanism. The value of the binding constant ( K
b ) for the interaction of HSA-chrysin complex (4.779 ± 0.623 × 105 M-1 at 300 K) was found to be higher than that of gHSA-chrysin complex (2.206 ± 0.234 × 105 M-1 at 300 K). Hence, non-enzymatic glycation of HSA significantly reduced its binding affinity towards chrysin. The % α-helicity of HSA was found to get enhanced upon binding with chrysin, and minimal changes were observed for the gHSA-chrysin complex. Site marker probe studies indicated that chrysin binds to subdomain IIA and IIIA of both HSA and gHSA. The results from molecular docking and MD simulation studies correlated well with the experimental findings. Electrostatic interactions followed by hydrogen bonding and hydrophobic interactions played major roles in the binding process. These observations may have some useful insights into the field of pharmaceutics.- Published
- 2021
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122. A Working Prototype Using DS18B20 Temperature Sensor and Arduino for Health Monitoring.
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Ramesh Saha, Biswas S, Sarmah S, Karmakar S, and Das P
- Abstract
Due to the successful emergence of internet of things, sensor-based real-time health monitoring is getting popularized. A usable health-monitoring system is required for prolonged monitoring of the patient with reduced cost. This paper describes a working prototype system for real-time health-monitoring system using DS18B20 temperature sensor, Arduino Nano with micro-controller ATmega328 where Zigbee module is used for wireless communication. In this prototype sensor data gets acquired and analyzed to give proper feedback to the patient with or without mobility support at indoor. The sensor vitals are collected and sent to the computing device using shielded cable and ZigBee, i.e., through wired and wireless communication, respectively. Analysis of patient vitals based on medical definitions gives patient's real-time health condition so that if condition is not normal, then timely preventive measures can be taken to avoid further complication. Per user data can be saved in the system database for further reference., Competing Interests: Conflict of interestNone., (© The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. part of Springer Nature 2021.)
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- 2021
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123. Protective actions of bioactive flavonoids chrysin and luteolin on the glyoxal induced formation of advanced glycation end products and aggregation of human serum albumin: In vitro and molecular docking analysis.
- Author
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Sarmah S, Das S, and Roy AS
- Subjects
- Anilino Naphthalenesulfonates chemistry, Benzothiazoles chemistry, Binding Sites, Flavonoids chemistry, Fluorescamine chemistry, Humans, Hydrophobic and Hydrophilic Interactions, Luteolin chemistry, Protein Binding, Spectrometry, Fluorescence, Spectrophotometry, Ultraviolet, Tryptophan chemistry, Flavonoids pharmacology, Glycation End Products, Advanced metabolism, Glyoxal toxicity, Luteolin pharmacology, Molecular Docking Simulation, Protective Agents pharmacology, Protein Aggregates drug effects, Serum Albumin, Human chemistry
- Abstract
The post-translational modification of proteins by nonenzymatic glycation (NEG) and the accumulation of AGEs are the two underlying factors associated with the long-term pathogenesis in diabetes. Glyoxal (GO) is a reactive intermediate which has the ability to modify proteins and generate AGEs at a faster rate. Human serum albumin (HSA) being the most abundant serum protein has a higher chance to be modified by NEG. The key objective of the present study is to investigate the potency of chrysin and luteolin as antiglycating and antifibrillating agents in the GO-mediated glycation and fibril formation of HSA. AGEs formation were confirmed from the absorption and fluorescence spectral measurements. Both the flavonoids were able to quench the AGEs fluorescence intensity in vitro indicating the antiglycating nature of the molecules. The formation of fibrils in the GO-modified HSA was confirmed by the Thioflavin T (ThT) fluorescence assay and the flavonoids were found to exihibit the antifibrillation properties in vitro. Docking results suggested that both the flavonoids interact with various amino acid residues of subdomain IIA including glycation prone lysines and arginines via non-covalent forces and further stabilized the structure of HSA, which further explains their mechanisms of action as antiglycating and antifibrillating agents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
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- 2020
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124. Protective effects of quercetin, polydatin, and folic acid and their mixtures in a zebrafish (Danio rerio) fetal alcohol spectrum disorder model.
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Cadena PG, Sales Cadena MR, Sarmah S, and Marrs JA
- Subjects
- Animals, Disease Models, Animal, Ethanol antagonists & inhibitors, Ethanol toxicity, Larva, Motor Activity drug effects, Zebrafish embryology, Fetal Alcohol Spectrum Disorders prevention & control, Folic Acid therapeutic use, Glucosides therapeutic use, Quercetin therapeutic use, Stilbenes therapeutic use
- Abstract
Protective effects of quercetin (QUE), polydatin (POL), and folic acid (FA) and their mixtures were tested using zebrafish to model fetal alcohol spectrum disorder in this study. Zebrafish embryos were exposed to 150 mM ethanol for 6 or 22 h and co-treated with QUE, POL, FA, and their mixtures (37.5-100.0 μM). Epiboly progression, teratogenic effects, and behavior were evaluated. Ethanol exposure reduced epiboly, and FA and QUE protected against these ethanol-induced defects. POL did not reduce epiboly defects. The mixture QUE + FA showed a possible antagonistic effect. The observed teratogenic effects were similar in all ethanol exposed groups. QUE, FA and QUE + POL reduced the percentage of affected animals, but treatments did not eliminate teratogenic effects. Behavioral measurements were divided into small (between 4 and 8 mm/s) and high swimming activity (>8 mm/s). All experimental groups displayed a reduction in small swimming activity as compared to control and ethanol groups when exposed to bright light. Additionally, larvae exposed to ethanol were more inhibited than control, not showing a habituation period (after 60 min of experiment) in high swimming activity. Chemical treatments like QUE and POL reduced behavioral defects induced by ethanol exposure. In conclusion, this study presents new evidence that QUE, POL, FA and their mixtures partially protected epiboly, teratogenic, and behavioral defects induced by ethanol exposure. QUE, FA and QUE + POL were more effective in reducing these defects than the other studied compounds and mixtures., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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125. Folic acid reduces the ethanol-induced morphological and behavioral defects in embryonic and larval zebrafish (Danio rerio) as a model for fetal alcohol spectrum disorder (FASD).
- Author
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Cadena PG, Cadena MRS, Sarmah S, and Marrs JA
- Subjects
- Abnormalities, Drug-Induced embryology, Air Sacs abnormalities, Animals, Behavior, Animal drug effects, Embryo, Nonmammalian, Eye Abnormalities chemically induced, Female, Larva, Locomotion drug effects, Male, Sleep drug effects, Tail abnormalities, Yolk Sac abnormalities, Zebrafish, Abnormalities, Drug-Induced drug therapy, Disease Models, Animal, Ethanol toxicity, Fetal Alcohol Spectrum Disorders, Folic Acid pharmacology, Teratogens toxicity
- Abstract
The objective of this work was to determine whether folic acid (FA) reduces the embryonic ethanol (EtOH) exposure induced behavioral and morphological defects in our zebrafish fetal alcohol spectrum disorder (FASD) model. Teratogenic effects, mortality, the excitatory light-dark locomotion (ELD), sleep (SL), thigmotaxis (TH), touch sensitivity (TS), and optomotor response (OMR) tests were evaluated in larvae (6-7 days post-fertilization) using four treatment conditions: Untreated, FA, EtOH and EtOH + FA. FA reduced morphological defects on heart, eyes and swim bladder inflation seen in EtOH exposed fish. The larvae were more active in the dark than in light conditions, and EtOH reduced the swimming activity in the ELD test. EtOH affected the sleep pattern, inducing several arousal periods and increasing inactivity in zebrafish. FA reduces these toxic effects and produced more consistent inactivity during the night, reducing the arousal periods. FA also prevented the EtOH-induced defects in thigmotaxis and optomotor response of the larvae. We conclude that in this FASD model, EtOH exposure produced several teratogenic and behavioral defects, FA reduced, but did not totally prevent, these defects. Understanding of EtOH-induced behavioral defects could help to identify new therapeutic or prevention strategies for FASD., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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126. Marijuana and Opioid Use during Pregnancy: Using Zebrafish to Gain Understanding of Congenital Anomalies Caused by Drug Exposure during Development.
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Sarmah S, Sales Cadena MR, Cadena PG, and Marrs JA
- Abstract
Marijuana and opioid addictions have increased alarmingly in recent decades, especially in the United States, posing threats to society. When the drug user is a pregnant mother, there is a serious risk to the developing baby. Congenital anomalies are associated with prenatal exposure to marijuana and opioids. Here, we summarize the current data on the prevalence of marijuana and opioid use among the people of the United States, particularly pregnant mothers. We also summarize the current zebrafish studies used to model and understand the effects of these drug exposures during development and to understand the behavioral changes after exposure. Zebrafish experiments recapitulate the drug effects seen in human addicts and the birth defects seen in human babies prenatally exposed to marijuana and opioids. Zebrafish show great potential as an easy and inexpensive model for screening compounds for their ability to mitigate the drug effects, which could lead to new therapeutics.
- Published
- 2020
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127. Role of calcium and phosphorous concentration as an intrinsic factor in the development of skull fracture following road traffic accidents.
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Tamuli RP, Saikia B, Sarmah S, and Patowary AJ
- Abstract
Introduction: Traumatic brain injury (TBI) or head injury is one of the leading causes of morbidity and mortality globally. TBI includes a fractured skull as an indicator of insult which can affect the treatment outcome as well. The development of any fracture depends on a combination of factors defining the intrinsic properties of the bone and the extrinsic factors related to the impact. A decrease in bone mass secondary to deficiency of calcium (Ca) and phosphorus (P) can be a significant factor intrinsic to the skull bone, which can modulate the outcome of the impact by increasing the susceptibility of bones towards fractures. We undertook this research to find out whether or not the Ca and P concentration in skull bone has a role to play as an intrinsic factor, in the development of skull fracture following Road Traffic Accidents (RTAs)., Methodology: In this case-control study conducted for two years, we collected 94 bone samples, i.e. 47 each, from skull bones with head injuries following RTA, with (case) and without (control) fracture of the skull. The elemental analyses for the bony concentration of Ca and P in both the groups were then compared using energy dispersive X-ray (EDX). Unpaired t -test and Fisher's exact test was used for statistical analysis., Results: The elemental analysis of bones provided evidence that suggests that whilst; Ca is the only mineral that appears to have a significant correlation with the development of fracture skull, the overall Ca: P ratio of less than 1.99 increases the chances of skull fracture by 3.9 times., Conclusions: Both individual bony Ca concentration and Ca: P ratio can be regarded as important intrinsic factors for the development of skull fracture., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Journal of Family Medicine and Primary Care.)
- Published
- 2020
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128. Exploring the interaction of bioactive kaempferol with serum albumin, lysozyme and hemoglobin: A biophysical investigation using multi-spectroscopic, docking and molecular dynamics simulation studies.
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Das S, Hazarika Z, Sarmah S, Baruah K, Rohman MA, Paul D, Jha AN, and Singha Roy A
- Subjects
- Circular Dichroism, Molecular Docking Simulation, Molecular Dynamics Simulation, Protein Binding, Spectrometry, Fluorescence, Thermodynamics, Hemoglobins chemistry, Kaempferols chemistry, Muramidase chemistry, Serum Albumin, Human chemistry
- Abstract
In recent years research based on kaempferol (KMP) has shown its potential therapeutic applications in medicinal chemistry and clinical biology. Therefore, to understand its molecular recognition mechanism, we studied its interactions with the carrier proteins, namely, human serum albumin (HSA), bovine hemoglobin (BHb) and hen egg white lysozyme (HEWL). The ligand, KMP was able to quench the intrinsic fluorescence of these three proteins efficiently through static quenching mode. The binding constant (K
b ) for the interactions of KMP with these three proteins were found in the following order: HSA-KMP > BHb-KMP > HEWL-KMP. Different non-covalent forces such as hydrogen bonding and hydrophobic forces played a major role in the binding of KMP with HSA and HEWL, whereas hydrogen bonding and van der Waals forces contribute to the complexation of BHb with KMP. KMP was able to alter the micro-environment near the Trp fluorophore of the proteins. KMP altered the secondary structural component of all three proteins. The putative binding sites and the residues surrounding the KMP molecule within the respective protein matrix were determined through molecular docking and molecular dynamics (MD) simulation studies. The conformational flexibility of the ligand KMP and the three individual proteins were also evident from the MD simulation studies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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129. Embryonic ethanol exposure alters expression of sox2 and other early transcripts in zebrafish, producing gastrulation defects.
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Sarmah S, Srivastava R, McClintick JN, Janga SC, Edenberg HJ, and Marrs JA
- Subjects
- Animals, Blastula cytology, Blastula drug effects, Blastula metabolism, Embryo, Nonmammalian cytology, Embryo, Nonmammalian drug effects, Embryo, Nonmammalian metabolism, Female, Gastrulation drug effects, Gene Expression Regulation, Developmental drug effects, Gene Expression Regulation, Developmental genetics, Gene Ontology, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction drug effects, Signal Transduction genetics, Ethanol pharmacology, Gastrulation genetics, Zebrafish embryology
- Abstract
Ethanol exposure during prenatal development causes fetal alcohol spectrum disorder (FASD), the most frequent preventable birth defect and neurodevelopmental disability syndrome. The molecular targets of ethanol toxicity during development are poorly understood. Developmental stages surrounding gastrulation are very sensitive to ethanol exposure. To understand the effects of ethanol on early transcripts during embryogenesis, we treated zebrafish embryos with ethanol during pre-gastrulation period and examined the transcripts by Affymetrix GeneChip microarray before gastrulation. We identified 521 significantly dysregulated genes, including 61 transcription factors in ethanol-exposed embryos. Sox2, the key regulator of pluripotency and early development was significantly reduced. Functional annotation analysis showed enrichment in transcription regulation, embryonic axes patterning, and signaling pathways, including Wnt, Notch and retinoic acid. We identified all potential genomic targets of 25 dysregulated transcription factors and compared their interactions with the ethanol-dysregulated genes. This analysis predicted that Sox2 targeted a large number of ethanol-dysregulated genes. A gene regulatory network analysis showed that many of the dysregulated genes are targeted by multiple transcription factors. Injection of sox2 mRNA partially rescued ethanol-induced gene expression, epiboly and gastrulation defects. Additional studies of this ethanol dysregulated network may identify therapeutic targets that coordinately regulate early development.
- Published
- 2020
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130. Characterization of Pseudomonas sp. TMB2 produced rhamnolipids for ex-situ microbial enhanced oil recovery.
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Haloi S, Sarmah S, Gogoi SB, and Medhi T
- Abstract
The present study describes the ex-situ production of a biosurfactant by Pseudomonas sp. TMB2 for its potential application in enhancing oil recovery. The physicochemical parameters such as temperature and pH were optimized as 30 °C and 7.2, respectively, for their maximum laboratory scale production in mineral salt medium containing glucose and sodium nitrate as best carbon and nitrogen sources. The surface activity of the resulting culture broth was declined from 71.9 to 33.4 mN/m having the highest emulsification activity against kerosene oil. The extracted biosurfactant was characterized chemically as glycolipid by Fourier-transform infrared spectroscopy and
1 H and13 C nuclear magnetic resonance spectroscopy analyses. The presence of mono-rhamnolipids (Rha-C8:2 , Rha-C10 , Rha-C10 -C10 , and Rha-C10 -C12:1 ) and di-rhamnolipids (Rha-Rha-C12 -C10, Rha-Rha-C10 -C10 , and Rha-Rha-C10 -C12:1 ) congeners were determined by liquid chromatography-mass spectroscopy analysis. The thermostability and degradation pattern of the candidate biosurfactant were tested by thermogravimetry assay and differential scanning calorimetry studies for its suitability in ex-situ oil recovery technology. The rhamnolipid based slug, prepared in 4000 ppm brine solution reduced the interfacial tension between liquid paraffin oil and aqueous solution to 0.8 mN/m from 39.1 mN/m at critical micelle concentration of 120 mg/L. The flooding test was performed using conventional core plugs belonging to oil producing horizons of Upper Assam Basin and recovered 16.7% of original oil in place after secondary brine flooding with microscopic displacement efficiency of 27.11%., Competing Interests: Conflict of interestThe authors declare that they do not have any conflict of interest., (© King Abdulaziz City for Science and Technology 2020.)- Published
- 2020
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131. Targeting the heme protein hemoglobin by (-)-epigallocatechin gallate and the study of polyphenol-protein association using multi-spectroscopic and computational methods.
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Das S, Sarmah S, Hazarika Z, Rohman MA, Sarkhel P, Jha AN, and Singha Roy A
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- Animals, Catechin chemistry, Cattle, Hydrophobic and Hydrophilic Interactions, Molecular Docking Simulation, Polyphenols chemistry, Protein Binding, Spectrum Analysis, Catechin analogs & derivatives, Hemoglobins chemistry, Hemoglobins metabolism, Polyphenols metabolism
- Abstract
In this work, the interaction of a bioactive tea polyphenol (-)-epigallocatechin gallate (EGCG) with bovine hemoglobin (BHb) along with its anti-oxidative behavior and the anti-glycation property have been explored using multi-spectroscopic and computational techniques. The binding affinity for EGCG towards BHb was observed to be moderate in nature with an order of 104 M-1, and the fluorescence quenching mechanism was characterized by an unusual static quenching mechanism. The binding constant (Kb) showed a continuous enhancement with temperature from 3.468 ± 0.380 × 104 M-1 at 288 K to 6.017 ± 0.601 × 104 M-1 at 310 K. The fluorescence emission measurements along with molecular docking studies indicated that EGCG binds near the most dominant fluorophore of BHb (β2-Trp37, at the interface of α1 and β2 chains) within the pocket formed by the α1, α2 and β2 chains. The sign and magnitude of the thermodynamic parameters, changes in enthalpy (ΔH = +17.004 ± 1.007 kJ mol-1) and in entropy (ΔS = +146.213 ± 2.390 J K-1 mol-1), indicate that hydrophobic forces play a major role in stabilizing the BHb-EGCG complex. The micro-environment around the EGCG binding site showed an increase in hydrophobicity upon ligand binding. The binding of EGCG with BHb leads to a decrease in the α-helical content, whereas that of the β-sheet increased. FTIR studies also indicated that the secondary structure of BHb changed upon binding with EGCG, along with providing further support for the presence of hydrophobic forces in the complexation process. Molecular docking studies indicated that EGCG binds within the cavity of α1, α2, and β2 chains surrounded by residues such as α1- Lys99, α1-Thr134, α1-Thr137, α1-Tyr140, α2-Lys127 and β2-Trp37. Molecular dynamics simulation studies indicated that EGCG conferred additional stability to BHb. Furthermore, moving away from the binding studies, EGCG was found to prevent the glyoxal (GO)-mediated glycation process of BHb, and it was also found to act as a potent antioxidant against the photo-oxidative damage of BHb.
- Published
- 2020
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132. Lysozyme-luteolin binding: molecular insights into the complexation process and the inhibitory effects of luteolin towards protein modification.
- Author
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Das S, Pahari S, Sarmah S, Rohman MA, Paul D, Jana M, and Singha Roy A
- Subjects
- Animals, Binding Sites drug effects, Chickens, Fluorescence, Hydrophobic and Hydrophilic Interactions, Kinetics, Models, Molecular, Molecular Structure, Thermodynamics, Luteolin chemistry, Luteolin pharmacology, Muramidase chemistry, Muramidase metabolism
- Abstract
In the proposed work, the complexation of bioactive flavonoid luteolin with hen egg white lysozyme (HEWL) along with its inhibitory influence on HEWL modification has been explored with the help of multi-spectroscopic and computational methods. The binding affinity has been observed to be moderate in nature (in the order of 10
4 M-1 ) and the static quenching mechanism was found to be involved in the fluorescence quenching process. The binding constant (Kb ) shows a progressive increase with the increase in temperature from (4.075 ± 0.046 × 104 M-1 ) at 293 K to (6.962 ± 0.024 × 104 M-1 ) at 313 K under experimental conditions. Spectroscopic measurements along with molecular docking calculations suggest that Trp62 is involved in the binding site of luteolin within the geometry of HEWL. The positive changes in enthalpy (ΔH = +19.99 ± 0.65 kJ mol-1 ) as well as entropy (ΔS = +156.28 ± 2.00 J K-1 mol-1 ) are indicative of the presence of hydrophobic forces that stabilize the HEWL-luteolin complex. The micro-environment around the Trp residues showed an increase in hydrophobicity as indicated by synchronous fluorescence (SFS), three dimensional fluorescence (3D) and red edge excitation (REES) studies. The % α-helix of HEWL showed a marked reduction upon binding with luteolin as indicated by circular dichroism (CD) and Fourier-transform infrared spectroscopy (FTIR) studies. Moreover, luteolin is situated at a distance of 4.275 ± 0.004 nm from the binding site as indicated by FRET theory, and the rate of energy transfer kET (0.063 ± 0.004 ns-1 ) has been observed to be faster than the donor decay rate (1/τD = 0.606 ns-1 ), which is indicative of the non-radiative energy transfer during complexation. Leaving aside the binding study, luteolin showed promising inhibitory effects towards the d-ribose mediated glycation of HEWL as well as towards HEWL fibrillation as studied by fluorescence emission and imaging studies. Excellent correlation with the experimental observations as well as precise location and dynamics of luteolin within the binding site has been obtained from molecular docking and molecular dynamics simulation studies.- Published
- 2019
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133. The Glycogen Synthase Kinase-3β Inhibitor LSN 2105786 Promotes Zebrafish Fin Regeneration.
- Author
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Sarmah S, Curtis C, Mahin J, Farrell M, Engler TA, Sanchez-Felix MV, Sato M, Ma YL, Chu S, and Marrs JA
- Abstract
The Wnt pathway has been shown to regulate bone homeostasis and to influence some bone disease states. We utilized a zebrafish model system to study the effects of a synthetic, orally bioavailable glycogen synthase kinase-3β (GSK3β) inhibitor LSN 2105786, which activates Wnt signaling during bone healing and embryogenesis. GSK3β inhibitor treatment was used to phenocopy GSK3β morpholino oligonucleotide (MO) knockdown in zebrafish embryos. Human and zebrafish synthetic mRNA injection were similarly effective at rescue of GSK3β MO knockdown. During caudal fin regeneration, bony rays are the first structure to differentiate in zebrafish fins, providing a useful model to study bone healing. Caudal fin regeneration experiments were conducted using various concentrations of a GSK3β inhibitor, examining duration and concentration dependence on regenerative outgrowth. Experiments revealed continuous low concentration (4-5 nM) treatment to be more effective at increasing regeneration than intermittent dosing. Higher concentrations inhibited fin growth, perhaps by excessive stimulation of differentiation programs. Increased Wnt responsive gene expression and differentiation were observed in response to GSK3b inhibitor treatment. Activating Wnt signaling also increased cell proliferation and osteoblast differentiation in fin regenerates. Together, these data indicate that bone healing in zebrafish fin regeneration was improved by activating Wnt signaling using GSK3b inhibitor treatment. In addition, caudal fin regeneration is useful to evaluate dose-dependent pharmacological efficacy in bone healing, various dosing regimens and possible toxicological effects of compounds.
- Published
- 2019
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134. Organ donation - "attitude and awareness among undergraduates and postgraduates of North-East India".
- Author
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Tamuli RP, Sarmah S, and Saikia B
- Abstract
Background: Organ donation is defined as "When a person allows an organ of theirs to be removed, legally, either by consent while the donor is alive or after death with the assent of the next of the kin." Common transplantations after organ donations include kidney, heart, liver, pancreas, intestines, lungs, bones, bone marrow, skin, and cornea. Although some organs such as kidney and tissues like part of the liver, pancreas, lungs, and intestines can be donated while the donor is alive, most of the donations occur only after the donor's death. In India, the legislative foundation for brain death and organ donation was officially established, under Transplantation of Human Organs Act, 1994 amended in 2011. It provided a much-needed legal and transparent system for organ donation. India's organ donation rate (ODR) stands at an abysmal 0.34 per million populations (PMP) when compared with donation rate of 36 PMP in countries like Spain. While in the rest of the country, states like Tamil Nadu, Maharashtra, Andhra Pradesh, and Gujarat have made efforts to ramp up their ODR, by facilitating public and private health sector activities, such vision is still a far cry for the states in the North-Eastern part of India., Materials and Methods: This study on awareness of organ donation was conducted in one of the premiere educational institutes at Guwahati. A predesigned performa (questionnaire) was used to collect data from 360 individual, of which 180 participants were undergraduate students and 180 participants were faculties having postgraduate degree., Results: The results show that 79.17% (285) of participants were aware about organ donation, and out of all participants, families of only three have donated organ in the past 5 years. A total number of 12 (3.33%) participants have signed up for organ donation. A significant portion of the study population (12.5%) opined that there might be some religious beliefs which are preventing certain strata of local population from donating or accepting organs. More than half (186) (51.67%) of the study group opined that there is lack of awareness among people which may be one of the reasons for low rates of organ donation., Conclusion: Organ donation programs are at a very primordial stage in India and are almost negligible in its North-Eastern region. It is high time for the policy makers and other stake holders of a global giant like India to understand the magnitude of the benefits from these programs. Making tangible policies that are reflected nationally, emphasizing attention to both the organ donors and recipients, is the need of the hour., Competing Interests: There are no conflicts of interest.
- Published
- 2019
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135. Harmful weed to prospective adsorbent: low-temperature-carbonized Ipomoea carnea stem carbon coated with aluminum oxyhydroxide nanoparticles for defluoridation.
- Author
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Saikia J, Sarmah S, Saikia P, and Goswamee RL
- Subjects
- Adsorption, Aluminum chemistry, Carbon, Cold Temperature, Hydrogen-Ion Concentration, Kinetics, Minerals, Prospective Studies, Temperature, Water Pollutants, Chemical, Water Purification, Fluorides chemistry, Ipomoea chemistry, Models, Chemical, Nanoparticles chemistry
- Abstract
Gainful utilization of stems of the pernicious weed, Ipomoea carnea, to prepare good quality carbon and its modification with aluminum oxyhydroxide (AlOOH) nanoparticles for efficient defluoridation from contaminated drinking water is discussed in this paper. Surface functional groups are enhanced by functionalization of the carbons under acid treatment which acted as anchor to the AlOOH nanoparticles. Formation of AlOOH particles over the carbon surface is confirmed from X-ray diffractometry analysis. The AlOOH-carbon nanocomposite showed higher fluoride removal capacity than the neat AlOOH nanoparticles with a maximum removal capacity in the range of 46.55-53.71 mg g
-1 . Reaction kinetics and isotherm studies showed that fluoride adsorption is quite feasible on the adsorbent surface. The column study showed the possibility of the adsorbent for large-scale applications. The adsorbent can be regenerated by a mild treatment with 0.1 N NaOH solutions. The adsorbent is highly capable for defluoridation from synthetic as well as fluoride-contaminated natural water and, thus, can be used as an alternative for commercial defluoridation adsorbents. The use of Ipomoea carnea for defluoridation can be a way of producing low-cost adsorbent material, and the use for such purposes may also be helpful to control the weed up to a good extent.- Published
- 2019
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136. Retinal Wnt signaling defect in a zebrafish fetal alcohol spectrum disorder model.
- Author
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Muralidharan P, Sarmah S, and Marrs JA
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors genetics, Cell Differentiation, Cell Proliferation drug effects, Disease Models, Animal, Embryo, Nonmammalian drug effects, Female, Fetal Alcohol Spectrum Disorders pathology, Folic Acid pharmacology, Nerve Tissue Proteins genetics, Photoreceptor Cells, Vertebrate cytology, Photoreceptor Cells, Vertebrate drug effects, Photoreceptor Cells, Vertebrate metabolism, Pregnancy, Receptors, Notch metabolism, Retina drug effects, Retina metabolism, Retinal Diseases chemically induced, Retinal Diseases pathology, Tretinoin pharmacology, Wnt Signaling Pathway, Zebrafish embryology, Zebrafish genetics, Ethanol adverse effects, Fetal Alcohol Spectrum Disorders metabolism, Retina pathology, Retinal Diseases metabolism
- Abstract
Fetal alcohol spectrum disorder caused by prenatal alcohol exposure includes ocular abnormalities (microphthalmia, photoreceptor dysfunction, cataracts). Zebrafish embryos exposed to ethanol from gastrulation through somitogenesis show severe ocular defects, including microphthalmia and photoreceptor differentiation defects. Ethanol-treated zebrafish had an enlarged ciliary marginal zone (CMZ) relative to the retina size and reduced Müller glial cells (MGCs). Ethanol exposure produced immature photoreceptors with increased proliferation, indicating cell cycle exit failure. Signaling mechanisms in the CMZ were affected by embryonic ethanol exposure, including Wnt signaling in the CMZ, Notch signaling and neurod gene expression. Retinoic acid or folic acid co-supplementation with ethanol rescued Wnt signaling and retinal differentiation. Activating Wnt signaling using GSK3 inhibitor (LSN 2105786; Eli Lilly and Co.) restored retinal cell differentiation pathways. Ethanol exposed embryos were treated with Wnt agonist, which rescued Wnt-active cells in the CMZ, Notch-active cells in the retina, proliferation, and photoreceptor terminal differentiation. Our results illustrate the critical role of Wnt signaling in ethanol-induced retinal defects., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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137. 3 rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study.
- Author
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Lau YJ, Sarmah S, and Witt JD
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Female, Follow-Up Studies, Hip Joint diagnostic imaging, Hip Joint physiopathology, Humans, Incidence, Male, Middle Aged, Postoperative Complications prevention & control, Prosthesis Design, Prosthesis Failure, Radiography, Range of Motion, Articular, Treatment Outcome, United Kingdom epidemiology, Young Adult, Arthroplasty, Replacement, Hip methods, Ceramics, Forecasting, Hip Joint surgery, Hip Prosthesis, Postoperative Complications epidemiology
- Abstract
Introduction: 3
rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings. The purpose of our study was to investigate the long-term clinical and radiographic results of 3rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture., Methods: The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured., Results: The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear., Conclusions: The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.- Published
- 2018
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138. Embryonic Ethanol Exposure Affects Early- and Late-Added Cardiac Precursors and Produces Long-Lasting Heart Chamber Defects in Zebrafish.
- Author
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Sarmah S and Marrs JA
- Abstract
Drinking mothers expose their fetuses to ethanol, which produces birth defects: craniofacial defects, cognitive impairment, sensorimotor disabilities and organ deformities, collectively termed as fetal alcohol spectrum disorder (FASD). Various congenital heart defects (CHDs) are present in FASD patients, but the mechanisms of alcohol-induced cardiogenesis defects are not completely understood. This study utilized zebrafish embryos and older larvae to understand FASD-associated CHDs. Ethanol-induced cardiac chamber defects initiated during embryonic cardiogenesis persisted in later zebrafish life. In addition, myocardial damage was recognizable in the ventricle of the larvae that were exposed to ethanol during embryogenesis. Our studies of the pathogenesis revealed that ethanol exposure delayed differentiation of first and second heart fields and reduced the number of early- and late-added cardiomyocytes in the heart. Ethanol exposure also reduced the number of endocardial cells. Together, this study showed that ethanol-induced heart defects were present in late-stage zebrafish larvae. Reduced numbers of cardiomyocytes partly accounts for the ethanol-induced zebrafish heart defects., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2017
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139. Turmeric Extract Rescues Ethanol-Induced Developmental Defect in the Zebrafish Model for Fetal Alcohol Spectrum Disorder (FASD).
- Author
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Muralidharan P, Connors CT, Mohammed AS, Sarmah S, Marrs K, Marrs JA, and Chism GW
- Subjects
- Animals, Curcuma anatomy & histology, Dietary Supplements analysis, Disease Models, Animal, Embryo, Nonmammalian, Female, Fetal Alcohol Spectrum Disorders physiopathology, Humans, Male, Plant Extracts analysis, Curcuma chemistry, Ethanol toxicity, Fetal Alcohol Spectrum Disorders prevention & control, Plant Extracts administration & dosage, Zebrafish growth & development
- Abstract
Prenatal ethanol exposure causes the most frequent preventable birth disorder, fetal alcohol spectrum disorder (FASD). The effect of turmeric extracts in rescuing an ethanol-induced developmental defect using zebrafish as a model was determined. Ethanol-induced oxidative stress is one of the major mechanisms underlying FASD. We hypothesize that antioxidant inducing properties of turmeric may alleviate ethanol-induced defects. Curcuminoid content of the turmeric powder extract (5 mg/mL turmeric in ethanol) was determined by UPLC and found to contain Curcumin (124.1 ± 0.2 μg/mL), Desmethoxycurcumin (43.4 ± 0.1 μg/mL), and Bisdemethoxycurcumin (36.6 ± 0.1 μg/mL). Zebrafish embryos were treated with 100 mM (0.6% v/v) ethanol during gastrulation through organogenesis (2 to 48 h postfertilization (hpf)) and supplemented with turmeric extract to obtain total curcuminoid concentrations of 0, 1.16, 1.72, or 2.32 μM. Turmeric supplementation showed significant rescue of the body length at 72 hpf compared to ethanol-treated embryos. The mechanism underlying the rescue remains to be determined., (© 2017 Institute of Food Technologists®.)
- Published
- 2017
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140. 3rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study.
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Lau YJ, Sarmah S, and Witt JD
- Abstract
Introduction: 3rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings.The purpose of our study was to investigate the long-term clinical and radiographic results of 3rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture., Methods: The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured., Results: The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear., Conclusions: The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.
- Published
- 2017
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141. Zebrafish as a Vertebrate Model System to Evaluate Effects of Environmental Toxicants on Cardiac Development and Function.
- Author
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Sarmah S and Marrs JA
- Subjects
- Animals, Environmental Exposure, Illicit Drugs toxicity, Models, Animal, Nanoparticles toxicity, Pesticides toxicity, Embryonic Development drug effects, Environmental Pollutants toxicity, Heart embryology, Heart Defects, Congenital chemically induced, Organogenesis drug effects, Water Pollutants, Chemical toxicity, Zebrafish embryology
- Abstract
Environmental pollution is a serious problem of the modern world that possesses a major threat to public health. Exposure to environmental pollutants during embryonic development is particularly risky. Although many pollutants have been verified as potential toxicants, there are new chemicals in the environment that need assessment. Heart development is an extremely sensitive process, which can be affected by environmentally toxic molecule exposure during embryonic development. Congenital heart defects are the most common life-threatening global health problems, and the etiology is mostly unknown. The zebrafish has emerged as an invaluable model to examine substance toxicity on vertebrate development, particularly on cardiac development. The zebrafish offers numerous advantages for toxicology research not found in other model systems. Many laboratories have used the zebrafish to study the effects of widespread chemicals in the environment on heart development, including pesticides, nanoparticles, and various organic pollutants. Here, we review the uses of the zebrafish in examining effects of exposure to external molecules during embryonic development in causing cardiac defects, including chemicals ubiquitous in the environment and illicit drugs. Known or potential mechanisms of toxicity and how zebrafish research can be used to provide mechanistic understanding of cardiac defects are discussed., Competing Interests: The authors declare no conflict of interest.
- Published
- 2016
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142. Common congenital anomalies: Environmental causes and prevention with folic acid containing multivitamins.
- Author
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Sarmah S, Muralidharan P, and Marrs JA
- Subjects
- Alcoholic Beverages adverse effects, Congenital Abnormalities epidemiology, Dietary Supplements, Ethanol adverse effects, Female, Humans, Infant, Pregnancy, Prenatal Exposure Delayed Effects chemically induced, Smoking adverse effects, Vitamins therapeutic use, Congenital Abnormalities etiology, Congenital Abnormalities prevention & control, Folic Acid therapeutic use
- Abstract
Congenital anomalies, congenital defects, or birth defects are significant causes of death in infants. The most common congenital defects are congenital heart defects (CHDs) and neural tube defects (NTDs). Defects induced by genetic mutations, environmental exposure to toxins, or a combination of these effects can result in congenital malformations, leading to infant death or long-term disabilities. These defects produce significant mortality and morbidity in the affected individuals, and families are affected emotional and financially. Also, society is impacted on many levels. Congenital anomalies may be reduced by dietary supplements of folic acid and other vitamins. Here, we review the evidence for specific roles of toxins (alcohol, cigarette smoke) in causing common severe congenital anomalies like CHDs, NTDs, and ocular defects. We also review the evidence for beneficial effects for dietary supplementation, and highlight gaps in our knowledge, where research may contribute to additional benefits of intervention that can reduce birth defects. Extensive discussion of common severe congenital anomalies (CHDs, NTDs, and ocular defects) illustrates the effects of diet on the frequency and severity of these defects. Birth Defects Research (Part C) 108:274-286, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)
- Published
- 2016
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143. Embryonic Ethanol Exposure Dysregulates BMP and Notch Signaling, Leading to Persistent Atrio-Ventricular Valve Defects in Zebrafish.
- Author
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Sarmah S, Muralidharan P, and Marrs JA
- Subjects
- Animals, Biomarkers, Bone Morphogenetic Proteins genetics, Embryonic Development genetics, Endocardium drug effects, Endocardium embryology, Endocardium metabolism, Gene Expression Regulation, Developmental, Heart Defects, Congenital pathology, Heart Valves abnormalities, Heart Valves embryology, Heart Valves metabolism, Heart Ventricles abnormalities, Heart Ventricles embryology, Heart Ventricles metabolism, Organogenesis drug effects, Receptors, Notch genetics, Wnt Proteins metabolism, Zebrafish, Bone Morphogenetic Proteins metabolism, Embryo, Nonmammalian drug effects, Embryo, Nonmammalian metabolism, Embryonic Development drug effects, Ethanol adverse effects, Heart Defects, Congenital etiology, Receptors, Notch metabolism, Signal Transduction drug effects
- Abstract
Fetal alcohol spectrum disorder (FASD), birth defects associated with ethanol exposure in utero, includes a wide spectrum of congenital heart defects (CHDs), the most prevalent of which are septal and conotruncal defects. Zebrafish FASD model was used to dissect the mechanisms underlying FASD-associated CHDs. Embryonic ethanol exposure (3-24 hours post fertilization) led to defects in atrio-ventricular (AV) valvulogenesis beginning around 37 hpf, a morphogenetic event that arises long after ethanol withdrawal. Valve leaflets of the control embryos comprised two layers of cells confined at the compact atrio-ventricular canal (AVC). Ethanol treated embryos had extended AVC and valve forming cells were found either as rows of cells spanning the AVC or as unorganized clusters near the AV boundary. Ethanol exposure reduced valve precursors at the AVC, but some ventricular cells in ethanol treated embryos exhibited few characteristics of valve precursors. Late staged larvae and juvenile fish exposed to ethanol during embryonic development had faulty AV valves. Examination of AVC morphogenesis regulatory networks revealed that early ethanol exposure disrupted the Bmp signaling gradient in the heart during valve formation. Bmp signaling was prominent at the AVC in controls, but ethanol-exposed embryos displayed active Bmp signaling throughout the ventricle. Ethanol exposure also led to mislocalization of Notch signaling cells in endocardium during AV valve formation. Normally, highly active Notch signaling cells were organized at the AVC. In ethanol-exposed embryos, highly active Notch signaling cells were dispersed throughout the ventricle. At later stages, ethanol-exposed embryos exhibited reduced Wnt/β-catenin activity at the AVC. We conclude that early embryonic ethanol exposure alters Bmp, Notch and other signaling activities during AVC differentiation leading to faulty valve morphogenesis and valve defects persist in juvenile fish., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2016
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144. Using Zebrafish to Implement a Course-Based Undergraduate Research Experience to Study Teratogenesis in Two Biology Laboratory Courses.
- Author
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Sarmah S, Chism GW 3rd, Vaughan MA, Muralidharan P, Marrs JA, and Marrs KA
- Subjects
- Animals, Students, Universities, Biology education, Science education, Teratogenesis, Zebrafish abnormalities
- Abstract
A course-based undergraduate research experience (CURE) spanning three semesters was introduced into freshman and sophomore biology classes, with the hypothesis that participation in a CURE affects skills in research, communication, and collaboration, which may help students persist in science. Student research projects were centered on the hypothesis that nicotine and caffeine exposure during early development affects gastrulation and heart development in zebrafish. First, freshmen generated original data showing distinct effects of embryonic nicotine and caffeine exposure on zebrafish heart development and function. Next, Cell Biology laboratory students continued the CURE studies and identified novel teratogenic effects of nicotine and caffeine during gastrulation. Finally, new freshmen continued the CURE research, examining additional toxicant effects on development. Students designed new protocols, made measurements, presented results, and generated high-quality preliminary data that were studied in successive semesters. By implementing this project, the CURE extended faculty research and provided a scalable model to address national goals to involve more undergraduates in authentic scientific research. In addition, student survey results support the hypothesis that CUREs provide significant gains in student ability to (1) design experiments, (2) analyze data, and (3) make scientific presentations, translating into high student satisfaction and enhanced learning.
- Published
- 2016
- Full Text
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145. Zebrafish retinal defects induced by ethanol exposure are rescued by retinoic acid and folic acid supplement.
- Author
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Muralidharan P, Sarmah S, and Marrs JA
- Subjects
- Animals, Cell Death drug effects, Embryo, Nonmammalian, Female, Pregnancy, Zebrafish, Dietary Supplements, Ethanol toxicity, Folic Acid administration & dosage, Retina abnormalities, Retina drug effects, Tretinoin administration & dosage
- Abstract
Fetal Alcohol Spectrum Disorder (FASD) is caused by prenatal alcohol exposure, producing craniofacial, sensory, motor, and cognitive defects. FASD is highly prevalent in low socioeconomic populations, which are frequently accompanied by malnutrition. FASD-associated ocular pathologies include microphthalmia, optic nerve hypoplasia, and cataracts. The present study characterizes specific retinal tissue defects, identifies ethanol-sensitive stages during retinal development, and dissects the effect of nutrient supplements, such as retinoic acid (RA) and folic acid (FA) on ethanol-induced retinal defects. Exposure to pathophysiological concentrations of ethanol (during midblastula transition through somitogenesis; 2-24 h post fertilization [hpf]) altered critical transcription factor expression involved in retinal cell differentiation, and produced severe retinal ganglion cell, photoreceptor, and Müller glial differentiation defects. Ethanol exposure did not alter retinal cell differentiation induction, but increased retinal cell death and proliferation. RA and FA nutrient co-supplementation rescued retinal photoreceptor and ganglion cell differentiation defects. Ethanol exposure during retinal morphogenesis stages (16-24 hpf) produced retinal defects like those seen with ethanol exposure between 2 and 24 hpf. Significantly, during an ethanol-sensitive time window (16-24 hpf), RA co-supplementation moderately rescued these defects, whereas FA co-supplementation showed significant rescue of optic nerve and photoreceptor differentiation defects. Interestingly, RA, but not FA, supplementation after ethanol exposure could reverse ethanol-induced optic nerve and photoreceptor differentiation defects. Our results indicate that various ethanol-sensitive events underlie FASD-associated retinal defects. Nutrient supplements like retinoids and folate were effective in alleviating ethanol-induced retinal defects., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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146. Financial analysis of revision knee surgery based on NHS tariffs and hospital costs: does it pay to provide a revision service?
- Author
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Kallala RF, Vanhegan IS, Ibrahim MS, Sarmah S, and Haddad FS
- Subjects
- Aged, Female, Humans, Length of Stay economics, Male, Middle Aged, Prosthesis Failure, Reoperation economics, United Kingdom, Arthroplasty, Replacement, Knee economics, Hospital Costs, Knee Prosthesis economics, Prosthesis-Related Infections economics, Prosthesis-Related Infections surgery, State Medicine economics
- Abstract
Revision total knee arthroplasty (TKA) is a complex procedure which carries both a greater risk for patients and greater cost for the treating hospital than does a primary TKA. As well as the increased cost of peri-operative investigations, blood transfusions, surgical instrumentation, implants and operating time, there is a well-documented increased length of stay which accounts for most of the actual costs associated with surgery. We compared revision surgery for infection with revision for other causes (pain, instability, aseptic loosening and fracture). Complete clinical, demographic and economic data were obtained for 168 consecutive revision TKAs performed at a tertiary referral centre between 2005 and 2012. Revision surgery for infection was associated with a mean length of stay more than double that of aseptic cases (21.5 vs 9.5 days, p < 0.0001). The mean cost of a revision for infection was more than three times that of an aseptic revision (£30 011 (sd 4514) vs £9655 (sd 599.7), p < 0.0001). Current NHS tariffs do not fully reimburse the increased costs of providing a revision knee surgery service. Moreover, especially as greater costs are incurred for infected cases. These losses may adversely affect the provision of revision surgery in the NHS., (©2015 The British Editorial Society of Bone & Joint Surgery.)
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- 2015
- Full Text
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147. Electronic and ligand properties of annelated normal and abnormal (mesoionic) N-heterocyclic carbenes: a theoretical study.
- Author
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Phukan AK, Guha AK, Sarmah S, and Dewhurst RD
- Abstract
The effect of annelation and carbonylation on the electronic and ligating properties of N-heterocyclic carbenes (NHCs) has been studied quantum chemically. The thermodynamic and kinetic stability of these NHCs have been assessed on the basis of their singlet-triplet and HOMO-LUMO gaps respectively. Both annelation and carbonylation have been found to decrease the stability of NHCs. Compared to nonannelated carbenes, annelated and carbonylated carbenes are found to be weaker σ donors but better π acceptors. However, the effect of carbonylation is more pronounced than annelation toward increasing the π acidity of the NHCs. The reactivity of these carbenes has been discussed in terms of nucleophilicity and electrophilicity indices. The calculated values of the relative redox potential and (31)P NMR chemical shifts of corresponding carbene-phosphinidene adducts have been found to correlate well with the π acidity of the NHCs.
- Published
- 2013
- Full Text
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148. Complex cardiac defects after ethanol exposure during discrete cardiogenic events in zebrafish: prevention with folic acid.
- Author
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Sarmah S and Marrs JA
- Subjects
- Alcohol-Induced Disorders embryology, Alcohol-Induced Disorders pathology, Animals, Central Nervous System Depressants pharmacology, Ethanol pharmacology, Gastrulation drug effects, Heart embryology, Heart Defects, Congenital chemically induced, Heart Defects, Congenital embryology, Heart Defects, Congenital pathology, Organogenesis drug effects, Alcohol-Induced Disorders prevention & control, Central Nervous System Depressants adverse effects, Ethanol adverse effects, Folic Acid pharmacology, Heart Defects, Congenital prevention & control, Vitamin B Complex pharmacology, Zebrafish embryology
- Abstract
Background: Fetal alcohol spectrum disorder (FASD) describes a range of birth defects including various congenital heart defects (CHDs). Mechanisms of FASD-associated CHDs are not understood. Whether alcohol interferes with a single critical event or with multiple events in heart formation is not known., Results: Our zebrafish embryo experiments showed that ethanol interrupts different cardiac regulatory networks and perturbs multiple steps of cardiogenesis (specification, myocardial migration, looping, chamber morphogenesis, and endocardial cushion formation). Ethanol exposure during gastrulation until cardiac specification or during myocardial midline migration did not produce severe or persistent heart development defects. However, exposure comprising gastrulation until myocardial precursor midline fusion or during heart patterning stages produced aberrant heart looping and defective endocardial cushions. Continuous exposure during entire cardiogenesis produced complex cardiac defects leading to severely defective myocardium, endocardium, and endocardial cushions. Supplementation of retinoic acid with ethanol partially rescued early heart developmental defects, but the endocardial cushions did not form correctly. In contrast, supplementation of folic acid rescued normal heart development, including the endocardial cushions., Conclusions: Our results indicate that ethanol exposure interrupted divergent cardiac morphogenetic events causing heart defects. Folic acid supplementation was effective in preventing a wide spectrum of ethanol-induced heart developmental defects., (Copyright © 2013 Wiley Periodicals, Inc.)
- Published
- 2013
- Full Text
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149. Stabilization of Si(0) and Ge(0) compounds by different silylenes and germylenes: a density functional and molecular electrostatic study.
- Author
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Sarmah S, Guha AK, Phukan AK, Kumar A, and Gadre SR
- Abstract
Recently, the chemistry of element (0) compounds has attracted the attention of both experimental and theoretical chemists. In this article, some new Si(0) and Ge(0) compounds stabilized by different silylene and germylene ligands are studied theoretically by applying quantum chemical calculations and topography mapping of molecular electrostatic potential (MESP). These compounds are found to have high donor-acceptor bond strengths and are thermodynamically stable. The nature of the molecular orbitals, negative values of MESP at its critical points, as well as proton affinity values suggest that they are very good nucleophiles. Calculated proton affinity values suggest the possible isolation of their diprotonated salts.
- Published
- 2013
- Full Text
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150. Ethanol exposure disrupts extraembryonic microtubule cytoskeleton and embryonic blastomere cell adhesion, producing epiboly and gastrulation defects.
- Author
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Sarmah S, Muralidharan P, Curtis CL, McClintick JN, Buente BB, Holdgrafer DJ, Ogbeifun O, Olorungbounmi OC, Patino L, Lucas R, Gilbert S, Groninger ES, Arciero J, Edenberg HJ, and Marrs JA
- Abstract
Fetal alcohol spectrum disorder (FASD) occurs when pregnant mothers consume alcohol, causing embryonic ethanol exposure and characteristic birth defects that include craniofacial, neural and cardiac defects. Gastrulation is a particularly sensitive developmental stage for teratogen exposure, and zebrafish is an outstanding model to study gastrulation and FASD. Epiboly (spreading blastomere cells over the yolk cell), prechordal plate migration and convergence/extension cell movements are sensitive to early ethanol exposure. Here, experiments are presented that characterize mechanisms of ethanol toxicity on epiboly and gastrulation. Epiboly mechanisms include blastomere radial intercalation cell movements and yolk cell microtubule cytoskeleton pulling the embryo to the vegetal pole. Both of these processes were disrupted by ethanol exposure. Ethanol effects on cell migration also indicated that cell adhesion was affected, which was confirmed by cell aggregation assays. E-cadherin cell adhesion molecule expression was not affected by ethanol exposure, but E-cadherin distribution, which controls epiboly and gastrulation, was changed. E-cadherin was redistributed into cytoplasmic aggregates in blastomeres and dramatically redistributed in the extraembryonic yolk cell. Gene expression microarray analysis was used to identify potential causative factors for early development defects, and expression of the cell adhesion molecule protocadherin-18a (pcdh18a), which controls epiboly, was significantly reduced in ethanol exposed embryos. Injecting pcdh18a synthetic mRNA in ethanol treated embryos partially rescued epiboly cell movements, including enveloping layer cell shape changes. Together, data show that epiboly and gastrulation defects induced by ethanol are multifactorial, and include yolk cell (extraembryonic tissue) microtubule cytoskeleton disruption and blastomere adhesion defects, in part caused by reduced pcdh18a expression.
- Published
- 2013
- Full Text
- View/download PDF
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