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Tiwari G, Mishra VK, Khanna A, Tyagi R, Sagar R. Synthesis of Chirally Enriched Pyrazolylpyrimidinone-Based Glycohybrids via Annulation of Glycals with 2-Hydrazineylpyrimidin-4(3 H)-ones. J Org Chem 2024; 89:5000-5009. [PMID: 38471017 DOI: 10.1021/acs.joc.4c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
A new strategy for synthesizing chirally enriched pyrazolylpyrimidinone-based glycohybrids has been achieved, employing an annulation approach in ethanol without any additives or catalysts under microwave conditions. The designed compounds were obtained within a short reaction time (5 min). This method offers several advantages, including mild reaction conditions, a green solvent, and a metal-free approach. Furthermore, the protocol demonstrated a broad substrate scope, successfully incorporating various functional groups with stereochemical diversity and furnishing chirally enriched molecules.
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Affiliation(s)
- Ghanshyam Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Vinay Kumar Mishra
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ram Sagar
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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Mishra VK, Khanna A, Tiwari G, Tyagi R, Sagar R. Recent developments on the synthesis of biologically active glycohybrids. Bioorg Chem 2024; 145:107172. [PMID: 38340475 DOI: 10.1016/j.bioorg.2024.107172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/11/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024]
Abstract
The exploration of hybridization emerges as a potent tool in advancing drug discovery research, with a significant emphasis on carbohydrate-containing hybrid scaffolds. Evidence indicates that linking carbohydrate molecules to privileged bioactive scaffolds enhances the bioactivity of drug molecules. This synergy results in a diverse range of activities, making carbohydrate scaffolds pivotal for synthesizing compound libraries with significant functional and structural diversity. Beyond their synthesis utility, these scaffolds offer applications in screening bioactive molecules, presenting alternative avenues for drug development. This comprehensive review spanning 2015 to 2023 focuses on synthesized glycohybrid molecules, revealing their bioactivity in areas such as anti-microbial, anti-cancer, anti-diabetic, anti-inflammatory activities, enzyme inhibition and pesticides. Numerous novel glycohybrids surpass positive control drugs in biological activity. This focused study not only highlights the diverse bioactivities of glycohybrids but also underscores their promising role in innovative drug development strategies.
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Affiliation(s)
- Vinay Kumar Mishra
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005
| | - Ghanshyam Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, 110067 New Delhi
| | - Ram Sagar
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005; Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, 110067 New Delhi.
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Tiwari G, Khanna A, Tyagi R, Mishra VK, Narayana C, Sagar R. Copper-catalyzed synthesis of pyrazolo[1,5-a]pyrimidine based triazole-linked glycohybrids: mechanistic insights and bio-applications. Sci Rep 2024; 14:529. [PMID: 38177184 PMCID: PMC10766964 DOI: 10.1038/s41598-023-50202-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/16/2023] [Indexed: 01/06/2024] Open
Abstract
Hybrid molecules maintain their stronghold in the drug market, with over 60% of drug candidates in pharmaceutical industries. The substantial expenses for developing and producing biologically privileged drugs are expected to create opportunities for producing hybrid molecule-based drugs. Therefore, we have developed a simple and efficient copper-catalyzed approach for synthesizing a wide range of triazole-linked glycohybrids derived from pyrazolo[1,5-a]pyrimidines. Employing a microwave-assisted copper-catalyzed approach, we developed a concise route using various 7-O-propargylated pyrazolo[1,5-a]pyrimidines and 1-azidoglycosides. This strategy afforded a series of twenty-seven glycohybrids up to 98% yield with diverse stereochemistry. All were achieved within a remarkably shortened time frame. Our investigation extends to evaluating the anticancer potential of these synthesized triazole-linked pyrazolo[1,5-a] pyrimidine-based glycohybrids. In-vitro assays against MCF-7, MDA-MB231, and MDA-MB453 cell lines reveal intriguing findings. (2R,3S,4S,5R,6R)-2-(acetoxymethyl)-6-(4-(((5-(4-chlorophenyl)pyrazolo[1,5-a]pyrimidin-7-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)tetrahydro-2H-pyran-3,4,5-triyl triacetate emerges as a standout with better anticancer activity against MDA-MB231 cells (IC50 = 29.1 µM), while (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-(4-(((5-(4-chlorophenyl)pyrazolo[1,5-a]pyrimidin-7-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)tetrahydro-2H-pyran-3,4,5-triyl triacetate demonstrates the best inhibitory effects against MCF-7 cells (IC50 = 15.3 µM) in all derived compounds. These results align with our docking analysis and structure-activity relationship (SAR) investigations, further validating the in-vitro outcomes. This work not only underscores the synthetic utility of our devised protocol but also highlights the promising potential of these glycohybrids as candidates for further anticancer therapeutic exploration.
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Affiliation(s)
- Ghanshyam Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Vinay Kumar Mishra
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Chintam Narayana
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Ram Sagar
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Tyagi R, Yadav K, Srivastava N, Sagar R. Applications of Pyrrole and Pyridine-based Heterocycles in Cancer Diagnosis and Treatment. Curr Pharm Des 2024; 30:255-277. [PMID: 38711394 DOI: 10.2174/0113816128280082231205071504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/23/2023] [Indexed: 05/08/2024]
Abstract
BACKGROUND The escalation of cancer worldwide is one of the major causes of economy burden and loss of human resources. According to the American Cancer Society, there will be 1,958,310 new cancer cases and 609,820 projected cancer deaths in 2023 in the United States. It is projected that by 2040, the burden of global cancer is expected to rise to 29.5 million per year, causing a death toll of 16.4 million. The hemostasis regulation by cellular protein synthesis and their targeted degradation is required for normal cell growth. The imbalance in hemostasis causes unbridled growth in cells and results in cancer. The DNA of cells needs to be targeted by chemotherapeutic agents for cancer treatment, but at the same time, their efficacy and toxicity also need to be considered for successful treatment. OBJECTIVE The objective of this study is to review the published work on pyrrole and pyridine, which have been prominent in the diagnosis and possess anticancer activity, to obtain some novel lead molecules of improved cancer therapeutic. METHODS A literature search was carried out using different search engines, like Sci-finder, Elsevier, ScienceDirect, RSC etc., for small molecules based on pyrrole and pyridine helpful in diagnosis and inducing apoptosis in cancer cells. The research findings on the application of these compounds from 2018-2023 were reviewed on a variety of cell lines, such as breast cancer, liver cancer, epithelial cancer, etc. Results: In this review, the published small molecules, pyrrole and pyridine and their derivatives, which have roles in the diagnosis and treatment of cancers, were discussed to provide some insight into the structural features responsible for diagnosis and treatment. The analogues with the chromeno-furo-pyridine skeleton showed the highest anticancer activity against breast cancer. The compound 5-amino-N-(1-(pyridin-4- yl)ethylidene)-1H-pyrazole-4-carbohydrazides was highly potent against HEPG2 cancer cell. Redaporfin is used for the treatment of cholangiocarcinoma, biliary tract cancer, cisplatin-resistant head and neck squamous cell carcinoma, and pigmentation melanoma, and it is in clinical trials for phase II. These structural features present a high potential for designing novel anticancer agents for diagnosis and drug development. CONCLUSION Therefore, the N- and C-substituted pyrrole and pyridine-based novel privileged small Nheterocyclic scaffolds are potential molecules used in the diagnosis and treatment of cancer. This review discusses the reports on the synthesis of such molecules during 2018-2023. The review mainly discusses various diagnostic techniques for cancer, which employ pyrrole and pyridine heterocyclic scaffolds. Furthermore, the anticancer activity of N- and C-substituted pyrrole and pyridine-based scaffolds has been described, which works against different cancer cell lines, such as MCF-7, A549, A2780, HepG2, MDA-MB-231, K562, HT- 29, Caco-2 cells, Hela, Huh-7, WSU-DLCL2, HCT-116, HBL-100, H23, HCC827, SKOV3, etc. This review will help the researchers to obtain a critical insight into the structural aspects of pyrrole and pyridine-based scaffolds useful in cancer diagnosis as well as treatment and design pathways to develop novel drugs in the future.
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Affiliation(s)
- Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110007, India
| | - Kanchan Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110007, India
| | - Nitin Srivastava
- Department of Chemistry, Amity University Lucknow Campus, Lucknow, Uttar Pradesh 226028, India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110007, India
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Yadav Y, Tyagi R, Yadav K, Tiwari G, Sagar R. Reinvestigation of SnCl 4 catalyzed efficient synthesis of 2,3-unsaturated glycopyranosides. Carbohydr Res 2023; 534:108989. [PMID: 38016255 DOI: 10.1016/j.carres.2023.108989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/20/2023] [Accepted: 11/20/2023] [Indexed: 11/30/2023]
Abstract
The Ferrier rearrangement is a powerful tool to prepare 2,3-unsaturated glycopyranosides. We have reinvestigated SnCl4 catalyzed Ferrier rearrangements through direct allylic substitution of the hydroxyl group at the C-3 position of glycals, resulting in the formation of stereoselective 2,3-unsaturated glycosides at 0 °C. The catalytic amount of SnCl4 (0.1 equiv.) was successfully used to promote this transformation on 3,4,6-tri-O-acetyl-D-glucal, 3,4,6-tri-O-acetyl-D-galactal and 3,4-di-O-acetyl-D-arabinal using various nucleophiles viz alcohols, azide and thiols to form a variety of 2,3-unsaturated glycopyranosides (pseudoglycals). This straightforward process is notable for its strong anomeric selectivity, excellent yields and shorter reaction time.
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Affiliation(s)
- Yogesh Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Kanchan Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ghanshyam Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India; Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
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Singh K, Sharma S, Tyagi R, Sagar R. Recent progress in the synthesis of natural product inspired bioactive glycohybrids. Carbohydr Res 2023; 534:108975. [PMID: 37871479 DOI: 10.1016/j.carres.2023.108975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 10/06/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023]
Abstract
Carbohydrates are a basic structural component that are indispensable to all cellular processes. In addition to being employed as chiral starting materials in the synthesis of a variety of natural products, carbohydrates are recognized as naturally occurring molecules having an enormous variety of functional, stereochemical, and structural properties. The understanding and biological roles of carbohydrate derived molecules can be greatly improved by selectively synthesizing functional carbohydrates through incorporating them with privileged scaffolds. For a deeper understanding of their roles and the development of functional materials based on sugar, it is crucial to develop new techniques for efficiently synthesizing, functionalizing, and modifying carbohydrates. Glycohybrids have a wide range of structural and functional characteristics along with protein-carbohydrate interactions that are crucial to mammalian biology and a number of disease states. This review, consisting the literature from January 2017 to July 2023 and provide an overview of recent developments in the chemical synthesis of glycohybrids based on natural product scaffolds of coumarin, quinolone, naphthalene diimide, indole, isatin, naphthoquinone, imidazole and pyrimidine. The biological activity of active glycohybrids are discussed in this review.
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Affiliation(s)
- Kavita Singh
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Sunil Sharma
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Verma N, Tyagi R, Khanna A, Malviya M, Sagar R. Electro-organic synthesis of isatins and hydrazones through C-N cross-coupling and C(sp 2)-H/C(sp 3)-H functionalization. Org Biomol Chem 2023; 21:6707-6714. [PMID: 37563999 DOI: 10.1039/d3ob01128c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
An efficient and unique approach to synthesize isatin (indole-2,3-dione) from 2-aminoacetophenone under electrochemical conditions supported by I2-DMSO through C-N cross-coupling and C(sp2)-H/C(sp3)-H functionalization is presented. This synthetic method spans a wide range of substituted 2-aminoacetophenone substrates. The use of iodine as a promoter and shorter reaction times produced good to very good yields of isatin derivatives, which is a significant improvement over the reaction in a batch process. Further, hydrazones of isatin were synthesized by using hydrazine hydrate which produces electrochemically active molecules, namely isatin-hydrazones. The hydrazones of acetophenone were also obtained using the same reaction protocol. Additionally, the effect of increasing scan rate studied using cyclic voltammetry shows that the process followed a diffusion-controlled mechanism.
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Affiliation(s)
- Neetu Verma
- Department of Chemistry, IIT (Banaras Hindu University), Varanasi-221005, India.
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India.
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Manisha Malviya
- Department of Chemistry, IIT (Banaras Hindu University), Varanasi-221005, India.
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India.
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
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Yadav R, Meena D, Singh K, Tyagi R, Yadav Y, Sagar R. Recent advances in the synthesis of new benzothiazole based anti-tubercular compounds. RSC Adv 2023; 13:21890-21925. [PMID: 37483662 PMCID: PMC10359851 DOI: 10.1039/d3ra03862a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/07/2023] [Indexed: 07/25/2023] Open
Abstract
This review highlights the recent synthetic developments of benzothiazole based anti-tubercular compounds and their in vitro and in vivo activity. The inhibitory concentrations of the newly synthesized molecules were compared with the standard reference drugs. The better inhibition potency was found in new benzothiazole derivatives against M. tuberculosis. Synthesis of benzothiazole derivatives was achieved through various synthetic pathways including diazo-coupling, Knoevenagel condensation, Biginelli reaction, molecular hybridization techniques, microwave irradiation, one-pot multicomponent reactions etc. Other than recent synthetic developments, mechanism of resistance of anti-TB drugs is also incorporated in this review. Structure activity relationships of the new benzothiazole derivatives along with the molecular docking studies of selected compounds have been discussed against the target DprE1 in search of a potent inhibitor with enhanced anti-tubercular activity.
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Affiliation(s)
- Rakhi Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Dilkhush Meena
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Kavita Singh
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Yogesh Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University New Delhi-110067 India
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Singh K, Behera SS, Tyagi R, Tiwari G, Sagar R. Metal free synthesis of 2,3-dideoxy-α, β-unsaturated carbohydrate enals (Perlin aldehydes). Carbohydr Res 2023; 531:108890. [PMID: 37406515 DOI: 10.1016/j.carres.2023.108890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/16/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
A metal free synthesis of enantiopure 2,3-dideoxy-α, β-unsaturated carbohydrate enals (Perlin aldehydes), in CH3CN-0.02 N H2SO4 in water (1:1, v/v) with 0.5 equivalent additives (4-hydroxy-6-methyl-2-pyrone or 4-amino coumarin), has been reported. This efficient protocol works well for the acetylated glycals (glucal, galactal and arabinal) and afforded Perlin aldehydes and hemiacetals in acceptable to good yields. Whereas, benzylated glycals furnished respective Perlin aldehydes, hemiacetals and the 2-deoxy derivatives, under similar reaction conditions. The products yields were significantly reduced when the additives were removed from the reaction mixture, indicating that they constitute an essential component of this approach. Further the use of 0.02 N H2SO4 in water: acetonitrile (1:1, v/v) solvent system is essential for the formation of Perlin aldehydes. The similar reactions under neutral reaction conditions (CH3CN:H2O, 1:1, v/v) with additives, afforded the hemiacetals as major product. This methodology is a metal free approach to Perlin aldehyde synthesis and therefore having additional benefit of its use in preparation of bioactive drug molecules, where metal toxicity is the major concern.
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Affiliation(s)
- Kavita Singh
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Sourav Sagar Behera
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ghanshyam Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India; Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.
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Yadav Y, Tyagi R, Kumar R, Sagar R. Conformationally locked sugar derivatives and analogues as potential neuraminidase inhibitors. Eur J Med Chem 2023; 255:115410. [PMID: 37120995 DOI: 10.1016/j.ejmech.2023.115410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/13/2023] [Accepted: 04/21/2023] [Indexed: 05/02/2023]
Abstract
The influenza virus remains a major health concern for mankind because it tends to mutate frequently and cause high morbidity. Influenza prevention and treatment are greatly aided by the use of antivirals. One such class of antivirals is neuraminidase inhibitors (NAIs), effective against influenza viruses. A neuraminidase on the virus's surface serves a vital function in viral propogation by assisting in the release of viruses from infected host cells. Neuraminidase inhibitors are the backbone in stoping such virus propagation thus helps in the treatment of influenza viruses infections. Two NAI medicines are licensed globally: Oseltamivir (Tamiflu™) and Zanamivir (Relanza™). There are two molecules that have acquired Japanese approval recently: Peramivir and Laninamivir, whereas Laninamivir octanoate is in Phase III clinical trials. The need for novel NAIs is due to frequent mutations in viruses and the rise in resistance against existing medication. The NA inhibitors (NAIs) are designed to have (oxa)cyclohexene scaffolds (a sugar scaffold) to mimic the oxonium transition state in the enzymatic cleavage of sialic acid. This review discusses in details and comprises all such conformationally locked (oxa)cyclohexene scaffolds and their analogues which have been recently designed and synthesized as potential neuraminidase inhibitors, thus as antiviral molecules. The structure-activity relationship of such diverese molecules has also been discussed in this review.
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Affiliation(s)
- Yogesh Yadav
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ramesh Kumar
- Department of Chemistry, Kurukshetra University Kurukshetra, Haryana, 136119, India
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Sabherwal P, Kalra N, Tyagi R, Khatri A, Srivastava S. Hypnosis and progressive muscle relaxation for anxiolysis and pain control during extraction procedure in 8-12-year-old children: a randomized control trial. Eur Arch Paediatr Dent 2021; 22:823-832. [PMID: 33782879 PMCID: PMC8006876 DOI: 10.1007/s40368-021-00619-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 03/17/2021] [Indexed: 11/30/2022]
Abstract
Introduction Hypnosis (H) and Progressive Muscle Relaxation (PMR) have proven to be effective in a variety of medical settings; there is a paucity of their practical application in paediatric dentistry. The study aimed to comparatively evaluate the role of H and PMR on anxiety, heart rate (HR), oxygen saturation (SPO2), blood pressure (BP), pain, and analgesic requirement during extraction in children. Materials and methods Sixty children aged 8–12 years undergoing primary molar extractions were randomly allocated to three groups—H, PMR, and control (C). The anxiety (proposed Visual Facial Anxiety scale), HR, and SPO2 were measured pre/post-operatively with/without interventions (H, PMR, C) at 4 intervals. The BP and pain (Wong-Baker faces pain scale) were recorded pre- and post-operatively. Need for analgesic post-operatively was assessed. Results Statistically significant reduction in anxiety was noted post-extraction in H (0.30 ± 0.80), PMR (0.50 ± 0.69) (p < 0.001*). HR showed a statistically significant drop after H, PMR application. (p < 0.001*) No significant difference in SPO2 was noted in the three groups (p > 0.05). Pain control was well achieved using H (85%), PMR (70%); BP was well-regulated in the H, PMR compared to C group (p < 0.001*). Need for analgesics was reduced in H (45%), PMR (50%) versus C (100%). Both techniques H, PMR were comparable in all measures. Conclusion Hypnosis and PMR are effective techniques for anxiolysis and pain control in paediatric dental patients.
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Affiliation(s)
- P Sabherwal
- Department of Pedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital University of Delhi, New Delhi, 110095, Delhi, India
| | - N Kalra
- Department of Pedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital University of Delhi, New Delhi, 110095, Delhi, India.
| | - R Tyagi
- Department of Pedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital University of Delhi, New Delhi, 110095, Delhi, India
| | - A Khatri
- Department of Pedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital University of Delhi, New Delhi, 110095, Delhi, India
| | - S Srivastava
- Department of Psychiatry, University College of Medical Sciences, Guru Teg Bahadur Hospital University of Delhi, New Delhi, 110095, Delhi, India
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Al-Mufti F, Kaur G, Amuluru K, Cooper JB, Dakay K, El-Ghanem M, Pisapia J, Muh C, Tyagi R, Bowers C, Cole C, Rosner S, Santarelli J, Mayer S, Gandhi C. Middle Meningeal Artery Embolization Using Combined Particle Embolization and n-BCA with the Dextrose 5% in Water Push Technique for Chronic Subdural Hematomas: A Prospective Safety and Feasibility Study. AJNR Am J Neuroradiol 2021; 42:916-920. [PMID: 33664110 DOI: 10.3174/ajnr.a7077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/25/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND PURPOSE Embolization of the middle meningeal artery for treatment of refractory or recurrent chronic subdural hematomas has gained momentum during the past few years. Little has been reported on the use of the n-BCA liquid embolic system for middle meningeal artery embolization. We present the technical feasibility of using diluted n-BCA for middle meningeal artery embolization. MATERIALS AND METHODS We sought to examine the safety and technical feasibility of the diluted n-BCA liquid embolic system for middle meningeal artery embolization. Patients with chronic refractory or recurrent subdural hematomas were prospectively enrolled from September 2019 to June 2020. The primary outcome was the safety and technical feasibility of the use of diluted n-BCA for embolization of the middle meningeal artery. The secondary end point was the efficacy in reducing hematoma volume. RESULTS A total of 16 patients were prospectively enrolled. Concomitant burr-hole craniotomies were performed in 12 of the 16 patients. Two patients required an operation following middle meningeal artery embolization for persistent symptoms. The primary end point was met in 100% of cases in which there were no intra- or postprocedural complications. Distal penetration of the middle meningeal artery branches was achieved in all the enrolled cases. A 7-day post-middle meningeal artery embolization follow-up head CT demonstrated improvement (>50% reduction in subdural hematoma volume) in 9/15 (60%) patients, with 6/15 (40%) showing an unchanged or stable subdural hematoma. At day 21, available CT scans demonstrated substantial further improvement (>75% reduction in subdural hematoma volume). CONCLUSIONS Embolization of the middle meningeal artery using diluted n-BCA and ethiodized oil (1:6) is safe and feasible from a technical standpoint. The use of a dextrose 5% bolus improves distal penetration of the glue.
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Affiliation(s)
- F Al-Mufti
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - G Kaur
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - K Amuluru
- Department of Neurointerventional Radiology (K.A.), Goodman Campbell Brain and Spine, Carmel, Indiana
| | - J B Cooper
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - K Dakay
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - M El-Ghanem
- Department of Neurology (M.E.-G.), University of Arizona-Tucson, Tucson, Arizona
| | - J Pisapia
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - C Muh
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - R Tyagi
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - C Bowers
- Department of Neurosurgery (C.B.), School of Medicine, University of New Mexico, Albuquerque, New Mexico
| | - C Cole
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - S Rosner
- Department of Neurosurgery (S.R.), New York-Presbyterian/Hudson Valley Hospital, Cortlandt Manor, New York
| | - J Santarelli
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - S Mayer
- Department of Neurocritical Care (S.M.), New York Medical College, Westchester Medical Center, Valhalla, New York
| | - C Gandhi
- From the Department of Neurosurgery (F.A.-M., G.K., J.B.C., K.D., J.P., C.M., R.T., C.C., J.S., C.G.), New York Medical College, Westchester Medical Center, Valhalla, New York
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Tyagi R, Srinivasan S. Molecular dynamics modeling of lithium ion intercalation induced change in the mechanical properties of Li xMn 2O 4. J Chem Phys 2020; 153:164712. [PMID: 33138392 DOI: 10.1063/5.0020823] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The objective of this study is to understand the fracture mechanisms in the lithium manganese oxide (LiMn2O4) electrode at the molecular level by studying mechanical properties of the material at different values of the State of Charge (SOC) using the principles of molecular dynamics (MD). A 2 × 2 × 2 cubic structure of the LiMn2O4 unit cell containing eight lithium ions, eight trivalent manganese ions, eight tetravalent manganese ions, and 32 oxygen ions is studied using a large-scale atomic/molecular massively parallel simulator. As part of the model validation, the lattice parameter and volume changes of LixMn2O4 as a function of SOC (0 < x < 1) have been studied and validated with respect to the experimental data. This validated model has been used for a parametric study involving the SOC value, strain rate (charge and discharge rate), and temperature. The MD simulations suggest that the lattice constant varies from 8.042 Å to 8.235 Å during a full discharging cycle, in agreement with the experimental data. The material at higher SOC shows more ductile behavior compared to low SOC values. Furthermore, yield and ultimate stresses are less at lower SOC values except when SOC values are within 0.125 and 0.375, verifying the phase transformation theory in this range. The strain rate does not affect the fully intercalated material significantly but seems to influence the material properties of the partially charged electrode. Finally, a study of the effect of temperature suggests that diffusion coefficient values for both high and low-temperature zones follow an Arrhenius profile, and the results are successfully explained using the vacancy diffusion mechanism.
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Affiliation(s)
- R Tyagi
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - S Srinivasan
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario L8S 4L8, Canada
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Mazumder D, Tyagi R, Chhabra J, Potluri R. PCV16 Increasing Burden of Cardiovascular Disease (CVD), the Associated Risk Factors and Drug Utilization Among Smokers in the US: A Study Based on Nhanes from 2005 to 2016. Value Health Reg Issues 2020. [DOI: 10.1016/j.vhri.2020.07.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Powles T, Oudard S, Grünwald V, Calvo E, Michaelson M, Burotto M, Melichar B, Tyagi R, Hilmi F, Gaur A, Hirschberg Y, Heng D. 718P A phase II study of patients with advanced or metastatic renal cell carcinoma (mRCC) receiving pazopanib after previous checkpoint inhibitor treatment. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.08.790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Tyczynski J, Potluri R, Tyagi R, Papademetriou E, Mazumder D. PD01.09 Incidence and Predictors Associated with the Development of Pneumonitis in Non-Small Cell Lung Cancer Patients. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.09.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Tyczynski J, Potluri R, Mazumder D, Tyagi R, Papademetriou E. PD01.08 Incidence and Predictors Associated with the Development of Peripheral Neuropathy in Non-Small Cell Lung Cancer Patients. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.09.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lohani J, Bag R, Padmavati M, Sapra S, Tyagi R. Coalesced nanomorphology, in situ , and ex situ applications of self assembled Gallium droplets grown by metal organic chemical vapor deposition. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Rao DS, Sankarasubramanian R, Kumar D, Singh V, Bhat KM, Mishra P, Vinayak S, Srinivasan T, Tyagi R, Muraleedharan K, Muralidharan R, Banerjee D. Microstructural and Compositional Characterisation of Electronic Materials. DEFENCE SCI J 2016. [DOI: 10.14429/dsj.66.10207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
<p class="p1"> </p><p class="p2"><span class="s1"> </span>Microstructural and compositional characterisation of electronic materials in support of the development of GaAs, GaN, and GaSb based multilayer device structures is described. Electron microscopy techniques employing nanometer and sub-nanometer scale imaging capability of structure and chemistry have been widely used to characterise various aspects of electronic and optoelectronic device structures such as InGaAs quantum dots, InGaAs pseudomorphic (pHEMT), and metamorphic (mHEMT) layers and the ohmic metallisation of GaAs and GaN high electron mobility transistors, nichrome thin film resistors, GaN heteroepitaxy on sapphire and silicon substrates, as well as InAs and GaN nanowires. They also established convergent beam electron diffraction techniques for determination of lattice distortions in III-V compound semiconductors, EBSD for crystalline misorientation studies of GaN epilayers and high-angle annular dark field techniques coupled with digital image analysis for the mapping of composition and strain in the nanometric layered structures. Also, <em>in-situ </em>SEM experiments were performed on ohmic metallisation of pHEMT device structures. The established electron microscopy expertise for electronic materials with demonstrated examples is presented.</p>
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Barthwal MS, Marwah V, Chopra M, Garg Y, Tyagi R, Kishore K, Vijay A, Dutta V, Katoch CDS, Singh S, Bhattacharya D. A Five-Year Study of Intrapleural Fibrinolytic Therapy in Loculated Pleural Collections. Indian J Chest Dis Allied Sci 2016; 58:17-20. [PMID: 28368566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
BACKGROUND Pleural fluid loculations due to complicated parapneumonic effusion (CPE), empyema, tubercular effusion and traumatic hemothorax can be managed either by video-assisted thoracoscopic surgery (VATS) or intrapleural ibrinolytic therapy (IPFT). The former is more invasive, not easily available and is also more expensive. On the other hand, IPFT is less invasive, cheaper, easily accessible and if used early, in loculated pleural collections, break loculations and early pleural peel, thereby facilitating pleural space drainage. OBJECTIVE To study the efficacy of IPFT in facilitating pleural space drainage in loculated pleural collections of diverse aetiologies. METHODS A five-year retrospective, observational study of 200 patients, with loculated pleural collections and failed tube drainage and managed with IPFT was carried out. Responders were defined as those with significant volume of fluid drained and significant radiological resolution. RESULTS There were 106 (53%) cases of CPE, 59 (29.5%) cases of tubercular effusion, 23 (11.5%) cases of empyema and 12 (6%) cases of hemothorax. Responders were 148 (74%) in number. The distribution of responders as per type of loculated pleural collection was as follows: CPE 88 (83%), tubercular 37 (62.7%), empyema 14 (60.8%) and traumatic hemothorax 11 (91.6%). The adverse effects were mild and included chest pain in six patients and low-grade transient fewer in three cases. CONCLUSIONS Intrapleural fibrinolytic therapy is a safe and cost-effective option in the management of selected patients with loculated pleural effusions.
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Bag RK, Singh S, Tyagi R, Pandya DK, Singh R. Study of Self-Induced Growth of AlGaAs Nanoneedles on Silicon Substrates Using Metal Organic Chemical Vapor Deposition Technique. J Nanosci Nanotechnol 2016; 16:973-980. [PMID: 27398556 DOI: 10.1166/jnn.2016.11767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A simple catalyst free growth method was used for the growth of single crystalline AlGaAs nanoneedles on Si substrate by metal organic chemical vapor deposition (MOCVD) technique. The growth mechanism of catalyst free growth of nanoneedles was investigated. The effect of growth rate, growth temperature and V/III ratio was studied in detail. The growth of nanoneedles required a careful optimization of the growth conditions. The formation of well-faceted nanoneedles with hexagonal cross-section was found to be influenced by the growth parameters. Based on these studies, the growth mechanism has been explained using nucleation theory. The growth of nanoneedles was believed to proceed via Vapor-Solid (VS) growth mechanism after the initial AlGaAs cluster formation depending on the growth conditions.
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Choudhuri A, Tyagi R, Tyagi R, Agarwal D, Uppal R. Early use of ulinastatin reduces Multiorgan Dysfunction (MODS) in septic shock following anastomotic failure. Clin Ther 2015. [DOI: 10.1016/j.clinthera.2015.05.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jain KK, Sahoo P, Tyagi R, Mehta A, Patir R, Vaishya S, Prakash N, Vasudev N, Gupta RK. Prospective glioma grading using single-dose dynamic contrast-enhanced perfusion MRI. Clin Radiol 2015; 70:1128-35. [PMID: 26152879 DOI: 10.1016/j.crad.2015.06.076] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 03/31/2015] [Accepted: 06/01/2015] [Indexed: 11/17/2022]
Abstract
AIM To evaluate the sensitivity and specificity of single-dose dynamic contrast-enhanced (DCE) perfusion magnetic resonance imaging (MRI) in prospective evaluation of glioma grading and to correlate the relative cerebral blood volume (rCBV) values with mitotic and ki-67 indexes obtained at histopathology. MATERIALS AND METHODS A total of 53 histologically proven patients with glioma were included in this study. DCE-MRI perfusion with a single dose of contrast medium was included in brain tumour protocol and prospective grading of glioma into low and high grade was done based on a previously reported rCBV cut-off value of 3. Tumours with rCBV ≥ 3 were considered to be high grade and rCBV < 3 were considered to be low grade. The sensitivity and specificity of the cut-off value were estimated. Ki-67 and mitotic indexes were also obtained on histopathological analysis along with histological grading. RESULTS Based on pre-defined rCBV cut-off values, prospective grading of low- and high-grade glioma was achieved with a sensitivity and specificity of 97.22% and 100%, respectively. Significant correlation was found between the mitotic/ki-67 indexes and rCBV values when data for high- and low-grade tumours was combined. CONCLUSION DCE-MRI performed with a single dose of contrast medium is as effective as a protocol with a double-dose of contrast medium for glioma grading using 3 T MRI and could be added to the routine evaluation protocol of brain tumours.
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Affiliation(s)
- K K Jain
- Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India
| | - P Sahoo
- Philips Healthcare, Philips India Ltd, Gurgaon, India
| | - R Tyagi
- Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India
| | - A Mehta
- Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India
| | - R Patir
- Neurosurgery, Fortis Memorial Research Institute, Gurgaon, India
| | - S Vaishya
- Neurosurgery, Fortis Memorial Research Institute, Gurgaon, India
| | - N Prakash
- Pathology, Fortis Memorial Research Institute, Gurgaon, India
| | - N Vasudev
- Pathology, Fortis Memorial Research Institute, Gurgaon, India
| | - R K Gupta
- Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India.
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Abstract
BACKGROUND COPD will become the third leading cause of death by 2020. There are many situations in which spirometry, the primary tool for diagnosis of COPD, cannot be performed, and thus, the staging and status of these patients cannot be determined. To date, there is no known biochemical marker used for diagnosing COPD. This study aimed to explore the utility of biomarkers for diagnosis of COPD. METHODS This was an observational study composed of 96 stable subjects with COPD and 96 subjects with normal lung function. Each group contained an equal number of smokers and nonsmokers. Serum levels of superoxide dismutase 3, glutathione peroxidase, catalase, ceruloplasmin ferroxidase activity, C-reactive protein, and surfactant protein D (SPD) were estimated. Ferroxidase activity was estimated by a kinetic method, whereas the other analytes were measured by enzyme-linked immunosorbent assay. The cutoff value, sensitivity and specificity at the cutoff value, and area under the curve for each analyte were determined from receiver operating characteristic curve. RESULTS Significantly decreased superoxide dismutase 3 and increased ferroxidase activity, SPD, glutathione peroxidase, and C-reactive protein levels were found in subjects with COPD. For all subjects and nonsmoking subjects with COPD, the area under the curve was highest for ferroxidase activity, followed by glutathione peroxidase, SPD, and C-reactive protein, with a sensitivity and specificity of > 73%. For smoking subjects with COPD, the area under the curve was highest for SPD, followed by glutathione peroxidase, ferroxidase activity, and C-reactive protein, with a sensitivity and specificity > 67%. Some combinations of markers were found to give either a sensitivity or specificity of > 95%, which can be utilized to rule in and rule out COPD. CONCLUSIONS Biomarkers can be reliably utilized in the diagnosis of COPD. Of all the markers, SPD appears to be the most promising in smokers, whereas ferroxidase activity shows promise in nonsmokers. To rule out COPD, ferroxidase activity or glutathione peroxidase can be potentially useful, whereas to rule in COPD, ferroxidase activity and glutathione peroxidase appear to be the most promising combination in both nonsmoking and smoking subjects.
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Affiliation(s)
| | - Alka N Sontakke
- Department of Biochemistry, Maharashtra Institute of Medical Education and Research Medical College, Talegaon, Pune, India
| | - M S Barthwal
- Department of Respiratory Medicine, Cardio-Thoracic Centre, Pune, India
| | - R Tyagi
- Department of Respiratory Medicine, Cardio-Thoracic Centre, Pune, India
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Affiliation(s)
- S Pandey
- Infertility Clinic/Laboratory; Javitri Hospital & Test-tube Baby Centre; Lucknow U.P. India
- Department of Biochemistry & Molecular Biology; University of Texas Medical Branch at Galveston; Galveston TX USA
| | - R Tyagi
- Infertility Clinic/Laboratory; Javitri Hospital & Test-tube Baby Centre; Lucknow U.P. India
- Infertility & Reproductive Medicine; Cleveland Clinic; Cleveland OH USA
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Tyagi P, Tyagi R. Synthesis of Bisphosphodiester Surfactants Derived from Tetradecanol and Different Methylene Chains as a Spacer Derived from α-ω-Alkyl Dibromides. TENSIDE SURFACT DET 2013. [DOI: 10.3139/113.110133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Bisphosphodiester surfactant is a name assigned to a family of synthetic amphiphiles possessing a hydrocarbon chain attached to another hydrocarbon chain via different methylene chains as a spacer derived from α-ω-alkyl dibromide (1,4-DBB, 1,6-DBH and 1,8-DBO). In the present study, a series of bisphosphodiester surfactants having C14 hydrophobic tail and different methylene chains as a spacer derived from α-ω-alkyl dibromide have been synthesized at 35°C. The effect of reaction variables like temperature, duration and molar ratios of mono tetradecyl phosphate, tetramethyl ammonium hydroxide and spacer on the yield of bisphosphodiester surfactants has also been reported. Modern instrumental techniques viz. FT-IR, 1HNMR, and 13CNMR were utilized to characterize the functional groups presence in synthesized bisphosphodiester surfactants. Elemental analysis of synthesized bisphosphodiester surfactants was also carried out. Surface active properties viz. surface tension, interfacial tension, critical micelle concentration and aqueous properties viz. foaming stability, wetting ability, emulsifying ability and dispersing power of synthesized gemini surfactants were also determined. Among all synthesized bisphosphodiester surfactants IIIb had maximum anionic content of 78.9%; and showed highest foaming ability (70 ml), superior dispersing ability (45.7%), whereas IIIc showed low CMC values (0.00026 mmol/l); minimum surface tension and interfacial tension (37.3 mN/m and 31.6 mN/m) respectively.
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Abstract
Abstract
Gemini surfactants are most exciting new types of surfactants. They have two hydrophilic head groups and two hydrophobic groups in a molecule separated by a spacer group. Nowadays different types of geminis have been synthesized. Geminis show some characteristic features like low cmc, high surface activity, high solubility in water, good foaming and wetting properties, as well as low Krafft temperature. Geminis imply low eye and skin irritation. These surfactants are widely used as antifoaming and antimicrobial agents. This review paper deals with synthesis, properties and applications of various gemini surfactants.
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Abstract
Abstract
Amphipatic compounds with connecting group between two lipophilic groups were prepared by phosphorylating a long chain alcohol (hexadecanol) with pyrophosphoric acid to prepare hexadecyl phosphate. Then the resulting hexadecyl phosphate was used to prepare bisphosphate surfactants with terminal dibromo alkanes viz. 1,4-dibromo butane or 1,6-dibromo hexane or 1,8-dibromo octane using acetonitrile as solvent. The structure of synthesized products were verified by modern analytical techniques viz. FT-IR, and 1H-NMR. The disodium salts of bisphosphate surfactants were obtained by neutralization of free acid with sodium hydroxide. The performance properties viz. foaming, wetting, emulsifying ability and anionic content of synthesized surfactants were also evaluated. The synthesized bisphosphate surfactant with 1,6-dibromo hexane possessed maximum anionic content and showed good water solubility, foaming, wetting, and emulsifying ability compared to conventional analogs.
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Bag RK, Mohan P, Singh S, Kumar A, Tyagi R, Pandya DK, Singh R. Growth of aluminum catalyzed AlGaAs nanowires on silicon substrate. J Nanosci Nanotechnol 2013; 13:1899-1902. [PMID: 23755616 DOI: 10.1166/jnn.2013.7106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Aluminum catalyzed AlGaAs nanowires were fabricated on Si (111) substrates using metal-organic chemical vapor deposition (MOCVD) technique at a low growth temperature of 450 degrees C. Grown structures were characterized by field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) techniques. Nanowire clusters were observed all over the substrate. Multiprong root-grown AlGaAs nanowire clusters as well as catalyst particle terminated growth was observed. The growth is explained by Vapor-Solid-Solid (VSS) and Vapor-Solid (VS) growth mechanisms using Al-Si binary phase diagram. EDS and PL measurement confirm the formation of AlGaAs nanowires.
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Affiliation(s)
- R K Bag
- Solid State Physics Laboratory, Lucknow Road, Timarpur, Delhi 110054, India
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Schiewe M, Tyagi R, Rothman C, Sims C. Assessing quality control standards in sperm counting and motility estimates to reduce variation. Fertil Steril 2011. [DOI: 10.1016/j.fertnstert.2011.07.1025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Tyagi R. The prevalence of nursing caries in Davangere preschool children and its relationship with feeding practices and socioeconomic status of the family. J Indian Soc Pedod Prev Dent 2008; 26:153-7. [PMID: 19008623 DOI: 10.4103/0970-4388.44030] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
UNLABELLED The aim of the present study was to find the prevalence of nursing caries in Davangere preschool children and its relationship with feeding practices and socioeconomic status of the family. MATERIALS AND METHODS A total of 813 children aged 2-6 years were screened for the present study from randomly selected three kindergarten schools each from Government, Government aided, and private managements. Clinical examination was done inside the respective schools. At the time of examination, a proforma was filled for each child comprising of DFS index. The questionnaire by Winter et al. was modified and used in this study. The completed proformas were statistically analyzed to find if any correlation existed between the nursing caries to the feeding practices and socioeconomic status of the family. RESULTS Duration of breastfeeding increases the number of children with nursing caries and the mean DFS. There is a strong and significant relationship between the severity of nursing caries and the degree of feeding abuse. Children from low socioeconomic status have increased early childhood caries. CONCLUSION The prevalence of nursing caries was 19.2% in Davangere preschool population. Nursing caries were more in children who were taking a feeding bottle to bed at night and were increasingly seen in large families and lower socioeconomic groups.
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Affiliation(s)
- R Tyagi
- I.T.S. CDSR Dental College and Hospital, Delhi-Meerut Road, Muradnagar, Ghaziabad, UP, India.
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Abstract
Cancer drug discovery is one of the most rapidly changing areas of pharmaceutical research. Uncontrolled proliferation is a hallmark of cancer cells. Over the past two decades, it has become increasingly clear that in many human cancers, hyperactivity of Cyclin Dependent Kinases (CDKs) is one of the mechanisms underlying the physiological hyper-proliferation. CDKs are serine/threonine protein kinases, which play an important role in cell-cycle regulation. Their sequential activation ensures, the correct timing and ordering of events required for cell cycle progression. Therefore, inhibition of CDKs, through the insertion of small molecules into its ATP binding pocket has emerged as a potential therapy method for cancers. Consequently, a number of small molecules with CDK inhibitory properties have been developed. Many of these have been evaluated as potent inhibitors and some are currently in clinical-trials for various types of cancer. This review reports various CDK inhibitors, natural as well as small molecules, along with their reported activities for various CDKs. It will highlight the potential for the development of novel anti-cancer molecules.
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Affiliation(s)
- P Sapra Sharma
- Department of Chemistry, C.S.S.S. (P. G.) College, Machhra, Meerut, Uttar Pradesh, India.
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Tyagi R, Donaldson K, Loftus CM, Jallo J. Hypertonic saline: a clinical review. Neurosurg Rev 2007; 30:277-89; discussion 289-90. [PMID: 17574484 DOI: 10.1007/s10143-007-0091-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 02/06/2007] [Accepted: 02/21/2007] [Indexed: 10/23/2022]
Abstract
Literature suggest that hypertonic saline (HTS) solution with sodium chloride concentration greater than the physiologic 0.9% can be useful in controlling elevated intracranial pressure (ICP) and as a resuscitative agent in multiple settings including traumatic brain injury (TBI). In this review, we discuss HTS mechanisms of action, adverse effects, and current clinical studies. Studies show that HTS administered during the resuscitation of patients with a TBI improves neurological outcome. HTS also has positive effects on elevated ICP from multiple etiologies, and for shock resuscitation. However, a prospective randomized Australian study using an aggressive resuscitation protocol in trauma patients showed no difference in amount of fluids administered during prehospital resuscitation, and no differences in ICP control or neurological outcome. The role of HTS in prehospital resuscitation is yet to be determined. The most important factor in improving outcomes may be prevention of hypotension and preservation of cerebral blood flow. In regards to control of elevated ICP during the inpatient course, HTS appears safe and effective. Although clinicians currently use HTS with some success, significant questions remain as to the dose and manner of HTS infusion. Direct protocol comparisons should be performed to improve and standardize patient care.
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Affiliation(s)
- R Tyagi
- Department of Neurological Surgery, Temple University, 3401 N. Broad St., Suite C540, Philadelphia, PA 19140, USA
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Prakash S, Tyagi R, Gogia AR, Singh R, Prakash S. Efficacy of three doses of tramadol with bupivacaine for caudal analgesia in paediatric inguinal herniotomy. Br J Anaesth 2006; 97:385-8. [PMID: 16798773 DOI: 10.1093/bja/ael155] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND This study was designed to evaluate the analgesic efficacy of three doses of tramadol, administered caudally with bupivacaine, in providing postoperative pain relief in children. METHODS Eighty children, aged between 2 and 8 yr, undergoing inguinal herniotomy were randomly allocated to receive bupivacaine 0.25% 0.75 ml kg(-1) (Group B; n=20), bupivacaine 0.25% 0.75 ml kg(-1) with tramadol 1 mg kg(-1) (Group BT1; n=20), bupivacaine 0.25% 0.75 ml kg(-1) with tramadol 1.5 mg kg(-1) (Group BT1.5; n=20), or bupivacaine 0.25% 0.75 ml kg(-1) with tramadol 2 mg kg(-1) (Group BT2; n=20) by the caudal route immediately after induction of general anaesthesia. Heart rate, arterial pressure and oxygen saturation were monitored. Postoperative pain was assessed at regular intervals for 24 h using All India Institute of Medical Sciences pain score. Analgesia was supplemented whenever pain score was >or=4. Duration of analgesia and requirement for additional analgesics was noted. RESULTS Duration of analgesia was longer in Group BT2 [(mean (SD) 12 (0.9) h] compared with Group B [4 (1) h], Group BT1 [8 (0.9) h], or Group BT1.5 [11 (1) h]; all P<0.001. Total consumption of rescue analgesic was significantly lower in group BT2 compared with other groups (P<0.001). There were no significant changes in heart rate, arterial pressure and oxygen saturation between groups. Adverse effects were not observed. CONCLUSIONS Caudal tramadol 2 mg kg(-1), combined with bupivacaine 0.25% 0.75 ml kg(-1), provided longer duration of postoperative analgesia and reduced requirement for rescue analgesic compared with tramadol 1 mg kg(-1) or 1.5 mg kg(-1) in children undergoing inguinal herniotomy.
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Affiliation(s)
- S Prakash
- Department of Anaesthesia and Intensive Care, Vardhman Mahavir Medical College and Safdarjang Hospital New Delhi, India.
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Gupta M, Neelakantan V, Mishra S, Tyagi R, Dinda A, Maulik S, Mukhopadhyay C, Goswami S. A6. An assessment of the role of reactive oxygen species in norepinephrine-induced apoptosis and hypertrophy of H9c2 cardiac myoblasts. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.03.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Sinha R, Verma R, Tyagi R. Extraluminal gallstone causing bowel obstruction. J Postgrad Med 2005; 51:131-2. [PMID: 16006709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Affiliation(s)
- R Sinha
- Department of Radiology, Leicester Royal Infirmary, Leicester LE1 5WW, United Kingdom.
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Tyagi R, Kumar A, Tyagi MB, Jha PN, Kumar HD, Sinha RP, Häder DP. Protective role of certain chemicals against UV-B-induced damage in the nitrogen-fixing cyanobacterium, Nostoc muscorum. J Basic Microbiol 2003; 43:137-47. [PMID: 12746856 DOI: 10.1002/jobm.200390014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The protective effects of L-cysteine, ascorbic acid, reduced glutathione, L-tryptophan, and sodium pyruvate against UV-B-induced damages were studied in the nitrogen-fixing cyanobacterium, Nostoc muscorum. When added to the culture suspension during UV-B treatment, these chemicals caused a significant protective effect on survival and growth of the organism. Sodium pyruvate conferred the strongest protection whereas the weakest effect was elicited by tryptophan. A 20 min exposure of a culture suspension to UV-B completely inactivated nitrogenase activity but the inactivation was strongly prevented by exogenous addition of ascorbic acid or reduced glutathione during UV-B exposure, and weakly prevented by pyruvate, cysteine and tryptophan. In vivo nitrate reductase activity was not completely lost even after 80 min of UV-B exposure, and addition of the test chemicals did not confer any significant protection to this enzyme. Whereas (14)CO(2) uptake was drastically inhibited (78% inhibition) by 30 min exposure to UV-B in the absence of any test chemical, about 76% activity remained when the UV-B exposure was given to cultures in the presence of ascorbic acid. These results suggest that the damaging effects of UV-B are substantially minimized by certain reducing agents, the protective effect being particularly strong on the O(2) sensitive enzyme, nitrogenase. Presence of these chemicals in their natural habitat or inside the cells of living organisms may partially protect/repair the damaging effects of UV-B radiation.
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Affiliation(s)
- R Tyagi
- Division of Microbiology, IARI, New Delhi, India
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40
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Rickman DS, Tyagi R, Zhu XX, Bobek MP, Song S, Blaivas M, Misek DE, Israel MA, Kurnit DM, Ross DA, Kish PE, Hanash SM. The gene for the axonal cell adhesion molecule TAX-1 is amplified and aberrantly expressed in malignant gliomas. Cancer Res 2001; 61:2162-8. [PMID: 11280781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The human TAX-1 gene encodes a Mr 135,000 glycoprotein that is transiently expressed on the surface of a subset of neurons during development and is involved in neurite outgrowth. The TAX-1 gene has been mapped to a region on chromosome 1 that has been implicated in microcephaly and the Van der Woude syndrome. Using restriction landmark genome scanning to search for amplified genes in gliomas, we found TAX-1 to be amplified in 2 high-grade gliomas among a group of 26 gliomas investigated. Real-time reverse transcription-quantitative PCR analysis detected high levels of TAX-1 mRNA in glial tumors, even in the absence of TAX-1 gene amplification. Immunohistochemical analysis revealed abundant levels of TAX-1 in neoplastic glial cells of glioblastoma multiforme tumors. Because glial tumors are highly invasive and in view of the role of TAX-1 in neurite outgrowth, we investigated the potential role of TAX-1 in glioma cell migration. Using an in vitro assay, we found that the migration of glioma tumor cells is profoundly reduced in the presence of either an anti-TAX-1 antibody or a TAX-1 antisense oligonucleotide. Our findings suggest that TAX-1 plays a role in glial tumorigenesis and may provide a potential target for therapeutic intervention.
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Affiliation(s)
- D S Rickman
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor 48109, USA
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41
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Sharma S, Tyagi R, Gupta MN, Singh TP. Enhancement of catalytic activity of enzymes by heating in anhydrous organic solvents: 3D structure of a modified serine proteinase at high resolution. Indian J Biochem Biophys 2001; 38:34-41. [PMID: 11563328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
For the first time, it is demonstrated that exposure of an enzyme to anhydrous organic solvents at optimized high temperature enhances its catalytic power through local changes at the binding region. Six enzymes, namely, proteinase K, wheat germ acid phosphatase, alpha-amylase, beta-glucosidase, chymotrypsin and trypsin were exposed to acetonitrile at 70 degrees C for three hr. The activities of these enzymes were found to be considerably enhanced. In order to understand the basis of this change in the activity of these enzymes, proteinase K was analyzed in detail using X-ray diffraction method. The overall structure of the enzyme was found to be similar to the native structure in aqueous environment. The hydrogen bonding system of the catalytic triad remained intact after the treatment. However, the water structure in the substrate binding site underwent some rearrangement as some of the water molecules were either displaced or completely absent. The most striking observation concerning the water structure was the complete deletion of the water molecule which occupied the position at the so-called oxyanion hole in the active site of the native enzyme. Three acetonitrile molecules were found in the present structure. All the acetonitrile molecules were located in the recognition site. Interlinked through water molecules, the sites occupied by acetonitrile molecules were independent of water molecules. The acetonitrile molecules are involved in extensive interactions with the protein atoms. The methyl group of one of the acetonitrile molecules (CCN1) interacts simultaneously with the hydrophobic side chains of Leu 96, Ile 107 and Leu 133. The development of such a hydrophobic environment at the recognition site introduced a striking conformation change in Ile 107 by rotating its side chain about C alpha-C beta bond by 180 degrees to bring about the delta-methyl group within the range of attractive van der Waals interactions with the methyl group of CCN1. A similar change had earlier been observed in proteinase K when it was complexed to a substrate analogue, lactoferrin fragment.
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Affiliation(s)
- S Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110 029, India
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Gupta MN, Tyagi R, Sharma S, Karthikeyan S, Singh TP. Enhancement of catalytic efficiency of enzymes through exposure to anhydrous organic solvent at 70 degrees C. Three-dimensional structure of a treated serine proteinase at 2.2 A resolution. Proteins 2000; 39:226-34. [PMID: 10737944 DOI: 10.1002/(sici)1097-0134(20000515)39:3<226::aid-prot50>3.0.co;2-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The enzyme behavior in anhydrous media has important applications in biotechnology. So far chemical modifications and protein engineering have been used to alter the catalytic power of the enzymes. For the first time, it is demonstrated that an exposure of enzyme to anhydrous organic solvents at optimized high temperature enhances its catalytic power through local changes at the binding region. Six enzymes: proteinase K, wheat germ acid phosphatase, alpha-amylase, beta-glucosidase, chymotrypsin and trypsin have been exposed to acetonitrile at 70 degrees C for three hours. The activities of these enzymes were found to be considerably enhanced. In order to understand the basis of this change in the activity of these enzymes, the structure of one of these treated enzymes, proteinase K has been analyzed in detail using X-ray diffraction method. The overall structure of the enzyme is similar to the native structure in aqueous environment. The hydrogen bonding system of the catalytic triad is intact after the treatment. However, the water structure in the substrate binding site undergoes some rearrangement as some of the water molecules are either displaced or completely absent. The most striking observation concerning the water structure pertains to the complete deletion of the water molecule which occupied the position at the so-called oxyanion hole in the active site of the native enzyme. Three acetonitrile molecules were found in the present structure. All the acetonitrile molecules are located in the recognition site. The sites occupied by acetonitrile molecules are independent of water molecules. The acetonitrile molecules are involved in extensive interactions with the protein atoms. All of them are interlinked through water molecules. The methyl group of one of the acetonitrile molecules (CCN1) interacts simultaneously with the hydrophobic side chains of Leu-96, Ile-107, and Leu-133. The development of such a hydrophobic environment at the recognition site introduces a striking conformation change in Ile-107 by rotating its side chain about C(alpha)--C(beta) bond by 180 degrees to bring about the delta-methyl group within the range of attractive van der Waals interactions with the methyl group of CCN1. A similar change has earlier been observed in proteinase K when it is complexed to a substrate analog lactoferrin fragment.
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Affiliation(s)
- M N Gupta
- Department of Chemistry, Indian Institute of Technology, New Delhi, India
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Tyagi R, Roy I, Agarwal R, Gupta MN. Carbodi-imide coupling of enzymes to the reversibly soluble insoluble polymer Eudragit S-100. Biotechnol Appl Biochem 1998; 28 ( Pt 3):201-6. [PMID: 9799717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The coupling of proteins and enzymes to soluble-insoluble polymers by carbodi-imide can be performed by using numerous variations of the protocol. This protocol has been investigated for the coupling of five different enzymes, namely wheatgerm acid phosphatase, beta-glucosidase, beta-galactosidase, trypsin and xylanase, to an enteric methacrylate polymer Eudragit S-100. The following results were found. (1) The activity of the bioconjugate was critically dependent on the physical state of the polymer and the pH of the coupling reaction. For example, in the case of wheatgerm acid phosphatase, the activity of the bioconjugate was 49% when coupling was performed at pH 7.2 and 67% when coupling was performed at pH 4. 5. With beta-galactosidase the corresponding values were 57% and 23% and with beta-glucosidase they were 57% and 52% respectively. (2) In some cases, such as beta-glucosidase and beta-galactosidase, it might be necessary to remove excess carbodi-imide before the addition of the enzyme to the activated matrix. (3) In most of the cases investigated, a sig-nificant amount of the enzyme (more than 90%) could be bound to the matrix merely by adsorption. (4) More importantly, after the carbodi-imide coupling procedure, a sufficient fraction of the bound enzyme could be eluted off the matrix, indicating that this was merely adsorbed and not covalently coupled.
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Affiliation(s)
- R Tyagi
- Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi-110 016, India
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Almeida A, Zhu XX, Vogt N, Tyagi R, Muleris M, Dutrillaux AM, Dutrillaux B, Ross D, Malfoy B, Hanash S. GAC1, a new member of the leucine-rich repeat superfamily on chromosome band 1q32.1, is amplified and overexpressed in malignant gliomas. Oncogene 1998; 16:2997-3002. [PMID: 9662332 DOI: 10.1038/sj.onc.1201828] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have used two-dimensional electrophoresis of enzyme-digested genomic DNA to identify a novel gene GAC1, which maps at 1q32.1 and which is overexpressed in malignant gliomas in which it is amplified. GAC1 encodes a protein which belongs to the leucine-rich repeat superfamily. Amplification and overexpression of GAC1 was demonstrated in two of eight tumors where amplifications were previously evidenced by comparative genomic hybridization (one glioblastoma multiforme and one anaplastic astrocytoma), and in one of eight unselected glioblastomas multiforme. GAC1 exhibits sequence homology with other proteins which function as cell-adhesion molecules or as signal transduction receptor and is a likely candidate for the target gene in the 1q32.1 amplicon in malignant gliomas.
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Affiliation(s)
- A Almeida
- Institut Curie-CNRS UMR 147, Paris, France
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45
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Kumar A, Ram T, Tyagi R, Goel B, Bansal E, Srivastava VK. Synthesis and anti-inflammatory activity of some potential cyclic phenothiazines. Boll Chim Farm 1998; 137:152-6. [PMID: 9689901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Some new schiff's bases (IVa-IVe), thiazolidinones (Va-Ve), delta 2-triazolines (VIa-VIe) and formazans (VIIa-VIIe) of 2-chlorophenothiazine have been synthesized and screened against Carrageenin induced oedema in albino rats. Some compounds of the series have shown promising activity. The most active compound is 2-chloro-10[5-(2-fluorophenyl-2-oxo-4 thiazolidin-1-yl)-amino acetyl] phenothiazine was found to be most potent. This compound (Vb) was further evaluated in detail and compared with phenylbutazone for its relative anti inflammatory potency (ED50), ulcerogenic liabilities (UD50) and acute toxicity (ALD50). It was found to be almost comparable to phenylbutazone as regards anti-inflammatory activity was concerned but and minimum ulcerogenic liability and cardiovascular effects. Hence, it seems promising as an anti-inflammatory agent in our preliminary studies.
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Affiliation(s)
- A Kumar
- Department of Pharmacology, LLRM Medical College Meerut. U.P., India
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46
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Tyagi R, Gupta MN. Chemical modification and chemical cross-linking for protein/enzyme stabilization. Biochemistry (Mosc) 1998; 63:334-44. [PMID: 9526130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The protein function as well as its stability is governed by the amino acid sequence which in turn defines the collective noncovalent interactions leading to its specific conformation. Hence, it is not surprising that chemical modification with monofunctional and bifunctional reagents (the latter is called chemical cross-linking) causes structural changes (sometimes even subtle) which can result in significant changes in the stability. This review, while recapitulating the early lessons, analyses recent work (including work from authors' laboratory) involving these twin approaches for protein stabilization. In the case of chemical modification, both surface hydrophilization and enhancing surface hydrophobicity are reported to have enhanced protein stability in different cases. For cross-linking, the nature, span, and position of the cross-link are important factors in the stabilization achieved. It is also pointed out that in the case of aqueous-organic cosolvent mixtures, protein stability may depend upon the nature of the organic solvents. In the case of polyphenol oxidase and trypsin (at least), it is possible to choose "good" solvents on the basis of the Polarity index of the solvent.
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Affiliation(s)
- R Tyagi
- Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi, 110016 India.
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Gupta M, Batra R, Tyagi R, Sharma A. Polarity Index: The Guiding Solvent Parameter for Enzyme Stability in Aqueous-Organic Cosolvent Mixtures. Biotechnol Prog 1997. [DOI: 10.1021/bp9700263] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Xylanase from Pectinex 3XL was purified 70-fold by precipitation with an enteric polymer, Eudragit S-100. The purified xylanase was immobilized on magnetic latex beads via carbodi-imide coupling. The immobilized preparation showed 80% of the total activity bound to the beads. The pH optimum remained unchanged at 6.0 and the Km increased from 0.25 g/100 ml (free enzyme) to 0.39 g/100 ml on immobilization. Immobilization resulted in significant thermal stability at 60 degrees C. The time course of hydrolysis of xylan at 60 degrees C by free enzyme as well as immobilized enzyme was also studied.
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Affiliation(s)
- R Tyagi
- Chemistry Department, Indian Institute of Technology, Delhi
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Srivastava R, Rajput YS, Khare SK, Tyagi R, Gupta MN. Purification and characterization of an acid phosphatase from Arachis hypogaea. Biochem Mol Biol Int 1995; 35:949-56. [PMID: 7549937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
An acid phosphatase from Arachis hypogaea (peanuts) has been purified. The electrophoretically homogeneous enzyme preparation is free of any phophodiesterase activity. The enzyme has a molecular weight of 120,000. Among the various phosphomonoesters tested, p-nitrophenylphosphate was found to be its most effective substrate. The Km for p-nitrophenylphosphate was 1.21 mM at pH 5.0 and 25 degrees C. The enzyme was thermostable and did not loose activity after 1 hr at 50 degrees C.
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John R, Tyagi R, Gupta MN. An insoluble aggregate of commercially available bovine serum albumin shows antiproteolytic activity. Biochem Mol Biol Int 1994; 33:263-72. [PMID: 7524898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chemical aggregation of bovine serum albumin by extensive chemical crosslinking with glutaraldehyde yielded an insoluble protein preparation with significant antiproteolytic activity. This was presumably due to the presence of alpha 2-macroglobulin in bovine serum albumin preparations. Chemical crosslinking of bovine serum albumin under optimum conditions was found to increase its antitryptic activity by about four times. The results indicate that enhanced rigidity of alpha 2-macroglobulin structure increases its antitryptic activity.
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Affiliation(s)
- R John
- Chemistry Department, IIT Delhi, India
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