Browsing by Author "Rajnish Kumar Chaturvedi"

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Bisphenol-A Impairs Myelination Potential During Development in the Hippocampus of the Rat Brain
(Humana Press Inc., 2015) Shashi Kant Tiwari; Swati Agarwal; Lalit Kumar Singh Chauhan; Vijay Nath Mishra; Rajnish Kumar Chaturvedi
Myelin is the functional implication of oligodendrocytes (OLs), which is involved in insulation of axons and promoting rapid propagation of action potential in the brain. OLs are derived from oligodendrocyte progenitor cells (OPCs), which proliferate, differentiate, and migrate throughout the central nervous system. Defects in myelination process lead to the onset of several neurological and neurodegenerative disorders. Exposure to synthetic xenoestrogen bisphenol-A (BPA) causes cognitive dysfunction, impairs hippocampal neurogenesis, and causes onset of neurodevelopmental disorders. However, the effects of BPA on OPC proliferation, differentiation and myelination, and associated cellular and molecular mechanism(s) in the hippocampus of the rat brain are still largely unknown. We found that BPA significantly decreased bromodeoxyuridine (BrdU)-positive cell proliferation and number and size of oligospheres. We observed reduced co-localization of BrdU with myelination markers CNPase and platelet-derived growth factor receptor-α (PDGFR-α), suggesting impaired proliferation and differentiation of OPCs by BPA in culture. We studied the effects of BPA exposure during prenatal and postnatal periods on cellular and molecular alteration(s) in the myelination process in the hippocampus region of the rat brain at postnatal day 21 and 90. BPA exposure both in vitro and in vivo altered proliferation and differentiation potential of OPCs and decreased the expression of genes and levels of proteins that are involved in myelination. Ultrastructural electron microscopy analysis revealed that BPA exposure caused decompaction of myelinated axons and altered g-ratio at both the developmental periods as compared to control. These results suggest that BPA exposure both during prenatal and postnatal periods alters myelination in the hippocampus of the rat brain leading to cognitive deficits. © 2014, Springer Science+Business Media New York.
Correction to: Bisphenol-A Impairs Myelination Potential During Development in the Hippocampus of the Rat Brain (Molecular Neurobiology, (2015), 51, 3, (1395-1416), 10.1007/s12035-014-8817-3)
(Humana Press Inc., 2019) Shashi Kant Tiwari; Swati Agarwal; Lalit Kumar Singh Chauhan; Vijay Nath Mishra; Rajnish Kumar Chaturvedi
The original version of this article unfortunately contained a mistake. The authors regret that inadvertent errors were observed in Figure 2E and Figure 10 B&D. The corrected representative images are now incorporated. These corrections does not change the conclusions and text of the article. The authors would like to apologize for any inconvenience caused. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Correction to: Inhibitory Effects of Bisphenol-A on Neural Stem Cells Proliferation and Differentiation in the Rat Brain Are Dependent on Wnt/β-Catenin Pathway (Molecular Neurobiology, (2015), 52, 3, (1735-1757), 10.1007/s12035-014-8940-1)
(Humana Press Inc., 2019) Shashi Kant Tiwari; Swati Agarwal; Brashket Seth; Anuradha Yadav; Ratan Singh Ray; Vijay Nath Mishra; Rajnish Kumar Chaturvedi
The original version of this article unfortunately contained a mistake. The authors observed inadvertent error in Figure 3A and 6C wish to correct it. The corrected representative images are incorporated below. This correction in no way changes the text of the article, conclusion and figure legend. The authors regret for this error and would like to apologize for any inconvenience caused to the readers. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Corrigendum: Possible Role for Bacteriophages in the Treatment of SARS-CoV-2 Infection (International Journal of Microbiology (2020) 2020 (5) DOI: 10.1155/2020/8844963)
(Hindawi Limited, 2022) Vijaya Nath Mishra; Kumari Nidhi; Abhishek Pathak; Rajnish Kumar Chaturvedi; Arun Kumar Gupta; Rameshwar Nath Chaurasia
In the article titled "Possible Role for Bacteriophages in the Treatment of SARS-CoV-2 Infection"[1], the authors wish to clarify that reference 13 in the article is a study on River Ganga and its self-cleansing properties and not directly related to sewage treatment as suggested. #e citation was used in this context because sewage water is entering River Ganga, and the river water was therefore considered to be contaminated with sewage water. Hence, testing the microbes of the water from River Ganga itself would ultimately be helpful in determining if the whole population has been infected with the virus or not. An additional reference should have been cited, included in the text below, as reference 41 [2]. Accordingly, the following paragraph in the Introduction section should be corrected from "Phage therapy (PT) was primarily developed to kill bacteria, to help prevent the overuse of antibiotics and the development of antibiotic resistance. Phages mediate immunoregulatory and immunotherapeutic activities that are relevant in balancing the immunological homeostasis of human subjects [4, 5]. Many bacteriophages possess hydrolytic enzymes called lysin, including endolysins and ectolysins, which help to rupture the bacterial peptidoglycan cell wall to allow entry of phage DNA [6]. Moreover, studies have even suggested the efficacy of PT in autoimmune diseases and allergies [7]"to "Phage therapy (PT) was primarily developed to kill bacteria, to help prevent the overuse of antibiotics and the development of antibiotic resistance. Phages mediate immunoregulatory and immunotherapeutic activities that are relevant in balancing the immunological homeostasis of human subjects [4, 5]. Many bacteriophages possess hydrolytic enzymes called lysin, including endolysins and ectolysins, which help to rupture the bacterial peptidoglycan cell wall to allow entry of phage DNA [6]. Moreover, studies have even suggested the efficacy of PT in autoimmune diseases and allergies [7]. One of the studies also concludes that during the viral infection, some of the bacterial colony also tends to spread vigorously in an infected human body. Like the infection of Acinetobacter baumanii and Klebsiella pneumoniae bacteria have been found in the COVID-19 patients. #is kind of infection can also cause sepsis, and in that situation, phages have been found helpful to treat the bacterial infection also in the COVID-19 patients [41]." © Copyright 2022 Vijaya Nath Mishra et al.
Ecological and Health Risk Assessment of Heavy Metals Bioaccumulation in Ganges Fish Near Varanasi, India
(Springer, 2024) Bhargawi Mishra; Geeta J. Gautam; Rajnish Kumar Chaturvedi; Nasreen Ghazi Ansari; Vijaya Nath Mishra
Heavy metal contamination in river Ganga is one of the factors for deterioration in its water quality and also adds to human health risks. We designed our study to achieve a holistic approach by not only estimating the concentration of heavy metals (lead, manganese, chromium, and cadmium) in the river water at different sites based on human anthropogenic activities but also in the fishes residing in the same sites that are collected for human consumption on daily basis. We found that Ganga River in Varanasi is highly loaded with metals (PLI = 6.698). Mean concentration in water was 1.29 mg/L for Pb, 1.325 mg/L for Mn, 0.169 mg/L for Cr, and 0.161 mg/L for Cd, which were above the permissible limits stated by Environment Protection Agency (EPA) in drinking water. Fish, including exotic and invasive species, were collected from the wild and were processed for the presence of these metals in their tissues. Degree of heavy metal concentration followed liver > gills > muscles. The highest accumulation of Pb was observed in Carpio (Cyprinus carpio) liver (8.86 µg/g) and lowest in Baikari (Clupisoma garua) muscles (0.07 µg/g). Total target hazard quotient (THQ) value, i.e., hazard index (HI) showed values in following sequence: Cyprinus carpio > Oreochromis niloticus > Channa gachua > Johnius coitor > Mastacembelus armatus > Mystus tengara > Clupisoma garua. Maximum HI value was recorded in C. carpio, which is highly consumed fish by humans, hence, may be harmful to them. Graphical Abstract: (Figure presented.) © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023.
Inhibitory Effects of Bisphenol-A on Neural Stem Cells Proliferation and Differentiation in the Rat Brain Are Dependent on Wnt/β-Catenin Pathway
(Humana Press Inc., 2015) Shashi Kant Tiwari; Swati Agarwal; Brashket Seth; Anuradha Yadav; Ratan Singh Ray; Vijay Nath Mishra; Rajnish Kumar Chaturvedi
Neurogenesis, a process of generation of new neurons, occurs throughout the life in the hippocampus and sub-ventricular zone (SVZ). Bisphenol-A (BPA), an endocrine disrupter used as surface coating for packaged food cans, injures the developing and adult brain. However, the effects of BPA on neurogenesis and underlying cellular and molecular mechanism(s) are still unknown. Herein, we studied the effect(s) of prenatal and early postnatal exposure of low dose BPA on Wnt/β-catenin signaling pathway that controls different steps of neurogenesis such as neural stem cell (NSC) proliferation and neuronal differentiation. Pregnant rats were treated with 4, 40, and 400 μg BPA/kg body weight orally daily from gestational day 6 to postnatal day 21. Both in vivo and in vitro studies showed that BPA alters NSC proliferation and differentiation. BPA impaired NSC proliferation (5′-bromo-2′-deoxyuridine (BrdU+) and nestin+ cells) and neuronal differentiation (BrdU/doublecortin+ and BrdU/neuronal nuclei (NeuN+) cells) in the hippocampus and SVZ as compared to control. It significantly altered expression/protein levels of neurogenic genes and the Wnt pathway genes in the hippocampus. BPA reduced cellular β-catenin and p-GSK-3β levels and decreased β-catenin nuclear translocation, and cyclin-D1 and TCF/LEF promoter luciferase activity. Specific activation and blockage of the Wnt pathway suggested involvement of this pathway in BPA-mediated inhibition of neurogenesis. Further, blockage of GSK-3β activity by SB415286 and GSK-3β small interfering RNA (siRNA) attenuated BPA-induced downregulation of neurogenesis. Overall, these results suggest significant inhibitory effects of BPA on NSC proliferation and differentiation in the rat via the Wnt/β-catenin signaling pathway. © 2014, Springer Science+Business Media New York.
Possible Role for Bacteriophages in the Treatment of SARS-CoV-2 Infection
(Hindawi Limited, 2020) Vijaya Nath Mishra; Nidhi Kumari; Abhishek Pathak; Rajnish Kumar Chaturvedi; Arun Kumar Gupta; Rameshwar Nath Chaurasia
An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan City, China, in December 2019. Since then, the outbreak has grown into a global pandemic, and neither a vaccine nor a treatment for the disease, termed coronavirus disease 2019 (COVID-19), is currently available. The slow translational progress in the field of research suggests that a large number of studies are urgently required. In this context, this review explores the impact of bacteriophages on SARS-CoV-2, especially concerning phage therapy (PT). Bacteriophages are viruses that infect and kill bacterial cells. Several studies have confirmed that in addition to their antibacterial abilities, bacteriophages also show antiviral and antifungal properties. It has also been shown that PT is effective for building immunity against viral pathogens by reducing the activation of NF kappa B; additionally, phages produce the antiviral protein phagicin. The Ganges river in India, which originates from the Himalayan range, is known to harbor a large number of bacteriophages, which are released into the river gradually by the melting permafrost. Water from this river has traditionally been considered a therapeutic agent for several diseases. In this review, we hypothesize that the Ganges river may play a therapeutic role in the treatment of COVID-19. © 2020 Vijaya Nath Mishra et al.