12 results on '"Amitava Khan"'
Search Results
2. Death to Memory Cells: Case of Hypogammaglobulinemia
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Amitava Khan and D. Das
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Hypogammaglobulinemia ,business.industry ,Immunology ,Medicine ,business ,medicine.disease - Published
- 2021
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3. An association study of severity of intellectual disability with peripheral biomarkers of disabled children in a rehabilitation home, Kolkata, India
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Swapan Mukherjee, Samrat Saha, Anup K. Sadhu, Amitava Khan, Tapashi Mitra, Saurabh Ghosh, Sushobhan Biswas, Suhrita Paul, Siddhartha Datta, Sanjit Dey, Krishnendu Manna, Tuhin Bhattacharya, Aaveri Sengupta, Rakhi Dey Sharma, and Ujjal Das
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Male ,medicine.medical_specialty ,Erythrocytes ,Adolescent ,Homocysteine ,Psychometrics ,medicine.medical_treatment ,lcsh:Medicine ,Neurophysiology ,India ,macromolecular substances ,medicine.disease_cause ,Severity of Illness Index ,Peripheral blood mononuclear cell ,Article ,chemistry.chemical_compound ,Neurotrophic factors ,Intellectual Disability ,Internal medicine ,Intellectual disability ,Severity of illness ,Humans ,Medicine ,lcsh:Science ,Child ,Disability ,Multidisciplinary ,Rehabilitation ,business.industry ,lcsh:R ,medicine.disease ,Disabled Children ,chemistry ,Child, Preschool ,lcsh:Q ,Lipid Peroxidation ,business ,Biomarkers ,Oxidative stress - Abstract
The current investigation has identified the biomarkers associated with severity of disability and correlation among plethora of systemic, cellular and molecular parameters of intellectual disability (ID) in a rehabilitation home. The background of study lies with the recent clinical evidences which identified complications in ID. Various indicators from blood and peripheral system serve as potential surrogates for disability related changes in brain functions. ID subjects (Male, age 10 ± 5 yrs, N = 45) were classified as mild, moderate and severe according to the severity of disability using standard psychometric analysis. Clinical parameters including stress biomarkers, neurotransmitters, RBC morphology, expressions of inflammatory proteins and neurotrophic factor were estimated from PBMC, RBC and serum. The lipid peroxidation of PBMC and RBC membranes, levels of serum glutamate, serotonin, homocysteine, ROS, lactate and LDH-A expression increased significantly with severity of ID whereas changes in RBC membrane β-actin, serum BDNF, TNF-α and IL-6 was found non-significant. Structural abnormalities of RBC were more in severely disabled children compared to mildly affected ones. The oxidative stress remained a crucial factor with severity of disability. This is confirmed not only by RBC alterations but also with other cellular dysregulations. The present article extends unique insights of how severity of disability is correlated with various clinical, cellular and molecular markers of blood. This unique study primarily focuses on the strong predictors of severity of disability and their associations via brain-blood axis.
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- 2019
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4. Transpalpebral extrusion of solid silicone buckle
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Abadan Amitava Khan
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Explants ,reattachment surgery ,transpalpebral extrusion ,Ophthalmology ,RE1-994 - Abstract
Explants used in retinal reattachment surgery occasionally extrude. Cheese-wiring of the suture through the sclera consequent to raised intraocular pressure allows the buckle to loosen and/or unfold. Subsequent infection, often with Staphylococcus albus, accelerates the process of extrusion. Commonly, such explants are of silicone sponge. The reported case is unusual in that the extrusion occurred through the upper lid, and involved a solid silicone explant.
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- 2009
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5. Naringin ameliorates radiation-induced hepatic damage through modulation of Nrf2 and NF-κB pathways
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Sanjit Dey, Amitava Khan, Anindita Chakraborty, Dipanwita Mukherjee, Sushobhan Biswas, Aaveri Sengupta, Krishnendu Manna, and Ujjal Das
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0301 basic medicine ,Programmed cell death ,Chemistry ,Kinase ,General Chemical Engineering ,NF-κB ,General Chemistry ,Molecular biology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Biochemistry ,Apoptosis ,TBARS ,Protein kinase A ,Protein kinase B ,PI3K/AKT/mTOR pathway - Abstract
Understanding the mechanism of ionizing radiation (IR)-induced systemic stress and its modulation by phytocomponents has great significance for the development of novel phyto-radioprotectors. The present study was intended to evaluate the radioprotective effect of naringin (NG), a citrus flavonoid on the modulation of IR-induced activation of the redox-regulated signaling system in murine liver. On the basis of survival analysis, mice were treated with 75 mg kg−1 body weight of NG for three consecutive days before irradiation (6 Gy). Pretreatment with NG significantly prevented the IR-induced generation of intracellular reactive oxygen species (ROS), along with the formation of hepatic thiobarbituric acid reactive substances (TBARS) and cellular nitrite. NG also showed significant reduction in IR-induced nuclear DNA damage through the inhibition of DNA-dependent protein kinase (DNA-PK). Further, the IR-induced cell death was arrested in the presence of NG through the inhibition of p53 mediated stress-activated protein kinase/Jun amino-terminal kinase (SAPK/JNK) pathways and modulation of other molecules of apoptosis pathways. Moreover, NG supported the intracellular defense mechanisms, by maintaining the endogenous antioxidants probably through phosphoinositide 3-kinase/protein kinase-B (PI3K/Akt) guided transcriptional activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In addition, NG inhibited IR-induced inflammation through suppression of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) followed by the alteration of pro inflammatory factors. Taken together, these results suggested that NG reversed the IR-induced redox-imbalance in murine liver, probably by the inhibition of ROS/p38-MAPK/NF-κB, along with the activation of the PI3K/Akt/Nrf2 pathway and the reduction of apoptosis by interfering with the p53/SAPK/JNK/Bax pathway.
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- 2016
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6. Gossypetin ameliorates ionizing radiation-induced oxidative stress in mice liver—a molecular approach
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Krishnendu Manna, Asoke Banerji, Kunal Sikder, Aaveri Sengupta, Ujjal Das, Swaraj Bandhu Kesh, Amitava Khan, Anindita Chakrabarty, Mahua Ghosh, Sushobhan Biswas, Mahuya Sinha, Dipesh Kr. Das, Sanjit Dey, and Sanjukta Datta
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Male ,NF-E2-Related Factor 2 ,Radioprotective Agent ,Drug Evaluation, Preclinical ,Biological Availability ,Radiation-Protective Agents ,Biology ,Pharmacology ,medicine.disease_cause ,Biochemistry ,Antioxidants ,Lipid peroxidation ,Mice ,Phosphatidylinositol 3-Kinases ,chemistry.chemical_compound ,medicine ,Animals ,DNA Breaks, Double-Stranded ,Aspartate Aminotransferases ,Protein kinase A ,Flavonoids ,chemistry.chemical_classification ,Reactive oxygen species ,Gossypetin ,Molecular Structure ,Interleukin-6 ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,Alanine Transaminase ,Free Radical Scavengers ,General Medicine ,Alkaline Phosphatase ,Catalase ,Glutathione ,Comet assay ,Oxidative Stress ,Liver ,chemistry ,Gamma Rays ,Apoptosis ,Hepatocytes ,Lipid Peroxidation ,Oxidation-Reduction ,Proto-Oncogene Proteins c-akt ,Oxidative stress ,Signal Transduction - Abstract
Radioprotective action of gossypetin (GTIN) against gamma (γ)-radiation-induced oxidative stress in liver was explored in the present article. Our main aim was to evaluate the protective efficacy of GTIN against radiation-induced alteration of liver in murine system. To evaluate the effect of GTIN, it was orally administered to mice at a dose of 30 mg/kg body weight for three consecutive days prior to γ-radiation at a dose of 5 Gy. Radioprotective efficacy of GTIN were evaluated at physiological, cellular, and molecular level using biochemical analysis, comet assay, flow cytometry, histopathology, immunofluorescence, and immunoblotting techniques. Ionizing radiation was responsible for augmentation of hepatic oxidative stress in terms of lipid peroxidation and depletion of endogenous antioxidant enzymes. Immunoblotting and immunofluorescence studies showed that irradiation enhanced the nuclear translocation of nuclear factor kappa B (NF-κB) level, which leads to hepatic inflammation. To investigate further, we found that radiation induced the activation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK)-mediated apoptotic pathway and deactivation of the NF-E2-related factor 2 (Nrf2)-mediated redox signaling pathway, whereas GTIN pretreatment ameliorated these radiation-mediated effects. This is the novel report where GTIN rationally validated the molecular mechanism in terms of the modulation of cellular signaling system’ instead of ‘ This is the novel report where GTIN is rationally validated in molecular terms to establish it as promising radioprotective agents. This might be fruitful especially for nuclear workers and defense personnel assuming the possibility of radiation exposure.
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- 2015
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7. Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India
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Surajit Bose, Anirban Pradhan, Amitava Khan, Sushobhan Biswas, Ujjal Das, Krishnendu Manna, Aaveri Sengupta, Saurabh Ghosh, and Sanjit Dey
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0301 basic medicine ,Adult ,Cyclin-Dependent Kinase Inhibitor p21 ,Male ,Pathology ,medicine.medical_specialty ,Erythrocytes ,Tobacco, Smokeless ,genetic structures ,India ,Nitric Oxide Synthase Type II ,Apoptosis ,Peripheral blood mononuclear cell ,Article ,03 medical and health sciences ,0302 clinical medicine ,Bcl-2-associated X protein ,Stress, Physiological ,TBARS ,Medicine ,Humans ,Interleukin 6 ,bcl-2-Associated X Protein ,Multidisciplinary ,biology ,business.industry ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,Lipids ,030104 developmental biology ,Smokeless tobacco ,Proto-Oncogene Proteins c-bcl-2 ,Cyclooxygenase 2 ,030220 oncology & carcinogenesis ,Immunology ,Absolute neutrophil count ,biology.protein ,Leukocytes, Mononuclear ,Tumor necrosis factor alpha ,Female ,Tumor Suppressor Protein p53 ,business - Abstract
Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC). The expressions of p53, p21, Bax, Bcl-2, IL-6, TNF- α, Cox-2, iNOS were analyzed from thirteen representative SLT-users and twelve non-users. Difference in CRP, random glucose, serum cholesterol, TG, HLDL-C, LDL-C, VLDL-C, neutrophil count, monocyte count, ESR, SOD (PBMC) and TBARS (RBC membrane) were found to be statistically significant (p
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- 2015
8. Dinuclear zinc(II) complexes with compartmental ligands: syntheses, structures, and bioactivities as artificial nuclease
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Sudhanshu Das, Sanjit Dey, Ennio Zangrando, Pali Maiti, Dipayan Bose, Tanmay Chattopadhyay, Debasis Das, Amitava Khan, Krishnendu Manna, Pali, Maiti, Amitava, Khan, Tanmay, Chattopadhyay, Sudhanshu, Da, Krishnendu, Manna, Dipayan, Bose, Sanjit, Dey, Zangrando, Ennio, and Debasis, Das
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Nuclease ,Coordination sphere ,[compartmental ligands] ,biology ,zinc(II) complex ,Stereochemistry ,Ligand ,Metal ions in aqueous solution ,chemistry.chemical_element ,Zinc ,Metal ,Trigonal bipyramidal molecular geometry ,chemistry ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,biology.protein ,compartmental ligands ,Chelation ,Physical and Theoretical Chemistry - Abstract
Four water-soluble dinuclear Zn(II) complexes (1–4) of compartmental ligand L = 2,6-bis(R-iminomethyl)-4-R′-phenolate (where R = N-ethylpiperidine or R = N-ethylpyrrolidine, R′ = methyl or tert-butyl) have been synthesized, characterized, and their DNA cleavage activity and cytotoxicity toward HepG2 cancerous cells are evaluated. The dinuclear complexes are formed by a pentadentate-substituted phenolate ligand chelating the metal ions separated by ca 3.27 A. Each metal is a distorted trigonal bipyramid, completing the coordination sphere through acetate. The X-ray structural determination of 2 shows that the complex is counterbalanced by half (formulation [Zn2L2(CH3CO2)2][(Zn(SCN)4]0.5), while in 1 and 3 two crystallographically-independent complexes are present in the unit cell with a . Among the four complexes only the 4-tert-butyl-phenolato derivatives (3 and 4) show DNA cleavage activity in in-vivo conditions and appear to be promising toward metal complexes to be used as anticancer agents. The cytoto...
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- 2011
9. Seabuckthron (Hippophae rhamnoides L.) leaf extract ameliorates the gamma radiation mediated DNA damage and hepatic alterations
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Amitava, Khan, Krishnendu, Manna, Chinchubose, Dipesh Kr, Das, Mahuya, Sinha, Swaraj Bandhu, Kesh, Ujjal, Das, Rakhi Sharma, Dey, Asoke, Banerji, and Sanjit, Dey
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Male ,Plant Leaves ,Mice ,Liver ,DNA, Superhelical ,Gamma Rays ,Plant Extracts ,Hippophae ,Animals ,Free Radical Scavengers ,DNA Damage - Abstract
In vitro assessment showed that H. rhamnoides (HrLE) extract possessed free radical scavenging activities and can protect gamma (gamma) radiation induced supercoiled DNA damage. For in vivo study, Swiss albino mice were administered with HrLE (30 mg/kg body weight) for 15 consecutive days before exposing them to a single dose of 5 Gy of beta radiation. HrLE significantly prevented the radiation induced genomic DNA damage indicated as a significant reduction in the comet parameters. The lipid peroxidation, liver function enzymes, expression of phosphorylated NFkappaB (p65) and IkappaBalpha increased whereas the endogenous antioxidants diminished upon radiation exposure compared to control. Pretreatment of HrLE extract ameliorated these changes. Based on the present results it can be concluded that H. rhamnoides possess a potential preventive element in planned and accidental nuclear exposures.
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- 2014
10. Role of ligand backbone of tridentate Schiff-base on complex nuclearity and bio-relevant catalytic activities of zinc(II) complexes: Experimental and theoretical investigations
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Debasis Das, Amitava Khan, Prateeti Chakraborty, Ennio Zangrando, Sanjit Dey, Krishnendu Manna, Antonio Bauzá, Ria Sanyal, Jaydeep Adhikary, Antonio Frontera, Chakraborty, Prateeti, Adhikary, Jaydeep, Sanyal, Ria, Khan, Amitava, Manna, Krishnendu, Dey, Sanjit, Zangrando, Ennio, Bauzá, Antonio, Frontera, Antonio, and Das, Debasis
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Materials Chemistry2506 Metals and Alloys ,Schiff base ,Ligand ,Stereochemistry ,Mononuclear zinc ,chemistry.chemical_element ,Trinuclear zinc ,Zinc ,Cleavage (embryo) ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Morpholine ,DFT study ,DNA cleavage activity ,Phosphatase activity ,Physical and Theoretical Chemistry ,Phosphodiester bond ,Materials Chemistry ,Hydroxyl radical - Abstract
Reaction of ZnII-acetate with two N, N, O-donor Schiff-base ligands, HL1 {4-Chloro-2-[(2-morpholin-4-yl-ethylimino)-methyl]-phenol} and HL2 {4-Chloro-2-[(3-morpholin-4-yl-propylimino)-methyl]-phenol}, which are formed in situ via condensation of 5-chlorosalicylaldehyde and N-(2-aminoethyl/propyl)morpholine, produce one tri- and one mononuclear species, Zn3L1(OAc)4 (1) and ZnL2(OAc) (2). The hypothetical ZnL1(OAc) and Zn3L2(OAc)4 are energetically unfavorable by 9.2 and 5.1 kcal/mol, in compare with their respective real counterparts 1 and 2 evidenced from DFT calculations. Both 1 and 2 catalyze the hydrolytic cleavage of phosphoester bond of (4-nitrophenyl) phosphate where 1 shows higher activity than that of 2. The proposed mechanistic pathways of phosphatase activity of 1 and 2 and the higher efficiency of the latter have been rationalized by DFT study. DNA cleavage activities have been investigated using supercoiled pET28a plasmid DNA where both the complexes show dose dependent DNA cleavage activity with varying degree. Complex 1 shows excellent breakage activity even at a concentration of 20 μM. However, in both cases hydroxyl radical pathway is most probably operative in DNA cleavage activity.
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- 2014
11. Dinuclear cobalt(II) complexes of Schiff-base compartmental ligands: Syntheses, crystal structure and bio-relevant catalytic activities
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Jaydeep Adhikary, Amitava Khan, Ennio Zangrando, Krishnendu Manna, Arpita Banerjee, Debasis Das, Averi Guha, Sanjit Dey, Banerjee, Arpita, Guha, Averi, Adhikary, Jaydeep, Khan, Amitava, Manna, Krishnendu, Dey, Sanjit, Zangrando, Ennio, and Das, Debasis
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DNA cleavage ,Schiff base ,Stereochemistry ,Cobalt(II) complexes ,Cytotoxicity ,Substrate (chemistry) ,chemistry.chemical_element ,Crystal structure ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Cobalt(II) complexes, DNA cleavage, Cytotoxicity, Catechol oxidase ,Catechol oxidase ,Materials Chemistry ,MTT assay ,Physical and Theoretical Chemistry ,Single crystal ,Cobalt ,DNA - Abstract
Three dicobalt(II) complexes, namely [Co2(L1H)(H2O)2(OAc)2](OAc)2 (1), [Co2(L2)(H2O)2(OAc)2](OAc) (2) and [Co2(L3)(H2O)2(OAc)2](OAc) (3) of the p-cresol based “end-off” compartmental ligands 2,6-bis(R-iminomethyl)-4-methyl-phenolato, where R = N-ethylpiperazine for L1, 2-ethylpyridine for L2 and N-ethylpiperidine for L3, have been synthesized and characterized by common physicochemical techniques, and in the case of complex 1 also by single crystal X-ray diffraction analysis. All the complexes show excellent catecholase-like activity, monitored not only with 3,5-di-tert-butylcatechol but also with tetrachlorocatechol, a substrate reluctant to be oxidized. To the best of our knowledge, to date no cobalt complex has been found in the literature to manifest such activity. The complexes are observed to interact efficiently with CT-DNA and on incubation (employing plasmid pTZ57/R/T DNA) they exhibit concentration dependent DNA cleavage activity. The mechanisms related to the DNA cleavage and catecholase-like activities have been investigated. The cytotoxicity of the complexes has also been examined through an MTT assay.
- Published
- 2013
12. Gossypetin ameliorates ionizing radiation-induced oxidative stress in mice liver—a molecular approach
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Amitava Khan, Krishnendu Manna, Dipesh Kr Das, Swaraj Bandhu Kesh, Mahuya Sinha, Ujjal Das, Sushobhan Biswas, Aaveri Sengupta, Kunal Sikder, Sanjukta Datta, Mahua Ghosh, Anindita Chakrabarty, Asoke Banerji, Sanjit Dey, Amitava Khan, Krishnendu Manna, Dipesh Kr Das, Swaraj Bandhu Kesh, Mahuya Sinha, Ujjal Das, Sushobhan Biswas, Aaveri Sengupta, Kunal Sikder, Sanjukta Datta, Mahua Ghosh, Anindita Chakrabarty, Asoke Banerji, and Sanjit Dey
- Published
- 2015
- Full Text
- View/download PDF
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