Browsing by Author "Vishal Kumar Singh"

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Chemokines Signature and T Cell Dynamics in Leishmaniasis: Molecular Insight and Therapeutic Application
(Cambridge University Press, 2024) Shreya Upadhyay; Shashi Kumar; Vishal Kumar Singh; Rahul Tiwari; Awnish Kumar; Shyam Sundar; Rajiv Kumar
Leishmaniasis, caused by obligate intracellular Leishmania parasites, poses a significant global health burden. The control of Leishmania infection relies on an effective T cell-dependent immune response; however, various factors impede the host's ability to mount a successful defence. Alterations in the chemokine profile, responsible for cell trafficking to the infection site, can disrupt optimal immune responses and influence the outcome of pathogenesis by facilitating parasite persistence. This review aims to emphasize the significance of the chemokine system in T cell responses and to summarize the current knowledge on the dysregulation of chemokines and their receptors associated with different subsets of T lymphocytes during Leishmaniasis. A comprehensive understanding of the dynamic nature of the chemokine system during Leishmaniasis is crucial for the development of successful immunotherapeutic approaches. © The Author(s), 2024. Published by Cambridge University Press.
Current and emerging therapies for the treatment of leishmaniasis
(Taylor and Francis Ltd., 2024) Shyam Sundar; Jitendra Singh; Vishal Kumar Singh; Neha Agrawal; Rajiv Kumar
Introduction: Leishmaniasis, a neglected protozoan illness caused by kinetoplastid pathogens encompasses three major clinical subtypes: visceral, cutaneous and mucocutaneous leishmaniasis. Pentavalent antimonials (SbV) have long been the preferred treatment worldwide but increased drug resistance, and significant side effects, including cardiotoxicity have limited their use, particularly in visceral leishmaniasis in India. Similarly, other approved alternatives have concerns such as teratogenicity, high cost, and drug resistance. Areas covered: This review aims to provide an overview of emerging therapy for leishmaniasis, highlighting the latest advancements in the field and discuss their potential impact on the treatment and prevention of this neglected tropical disease. It also discusses the limitation of current treatments and need for novel approaches to address them effectively. Expert opinion: For almost eight decades, treatment for all forms of leishmaniasis was solely dependent on SbV, despite several drawbacks like long treatment regimens, cardiotoxicity, and drug resistance. In the past 20 years, three drugs with antileishmanial activity were developed for human disease, but their distribution to endemic regions and accessibility for patients remain neglected. We sorely need new antileishmanial drugs, and we present here the emerging targets for developing new antileishmanial compounds that could be brought into the clinics. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Emerging role of γδ T cells in protozoan infection and their potential clinical application
(Elsevier B.V., 2022) Awnish Kumar; Bhawana Singh; Rahul Tiwari; Vishal Kumar Singh; Siddharth Sankar Singh; Shyam Sundar; Rajiv Kumar
γδ T cells are thymus derived heterogeneous and unconventional T- lymphocyte expressing TCR γ (V γ9) and TCRδ (Vδ2) chain and play an important role in connecting innate and adaptive armaments of immune response. These cells can recognize wide ranges of antigens even without involvement of major histocompatibility complex and exert their biological functions by cytotoxicity or activating various types of immune cells. In recent past, γδ T cells have emerged as an important player during protozoa infection and rapidly expand after exposure with them. They have also been widely studied in vaccine induced immune response against many bacterial and protozoan infections with improved clinical outcome. In this review, we will discuss the various roles of γδ T cells in immunity against malaria and leishmaniasis, the two important protozoan diseases causing significant mortality and morbidity throughout the world. © 2022
Export Assistance Programme and Handloom Industry: A Literature Review
(Institute of Physics, 2022) Vishal Kumar Singh; Amit Gautam
This research focuses on the handloom industry's export support programme. The present governmental export support programme is divided into four determinants based on their features, and those four determinants of export help were found by thorough literature research and analysis of the governmental aid programmes for the handloom sector. The financial support structure has a significant impact on export assistance since it provides numerous tax refunds and other concessions. This research primarily focuses on various works of literature relating to the handloom business, with the goal of extracting the common thread running across all of the studies. © The Electrochemical Society
Factors influencing adoption of metaverse platform: Gen Z perspective
(Emerald Publishing, 2025) Pravin Chandra Singh; Abhishek Kumar Pandey; Premendra Sahu; Vishal Kumar Singh; Sujay Vikram Singh; Kumari Neelam; Pankaj Kumar
This chapter examines Generation Z metaverse platform acceptance. This study examined participants' use intentions using the extended unified theory of acceptance and use of technology (UTAUT2) paradigm. The study exclusively covers Delhi NCR and considers games platform in metaverse; hence, conclusions can only be applied to games platform. Several factors influence consumers' intention to use metaverse platforms. This category includes performance expectations, effort expectations, social influence, facilitating conditions, hedonic motivation, price value, and habit. This research also shows a strong correlation between behavioral intention and use behavior with respect to metaverse in gaming platform use. © 2025 by Pravin Chandra Singh, Abhishek Kumar Pandey, Premendra Sahu, Vishal Kumar Singh, Sujay Vikram Singh, Kumari Neelam and Pankaj Kumar. All rights reserved.
Green export strategies and SMEs export performance: mediating roles of innovation, readiness, and activities
(Springer Science and Business Media Deutschland GmbH, 2024) Vishal Kumar Singh; Aditya Keshari; Divya Singh; Pravin Chandra Singh; Amit Gautam
Purpose: This study aims to investigate the relationship between institutional support, green export strategies, and export performance among small and medium-sized enterprises (SMEs) operating in various sustainability-focused sectors. Design/methodology/approach: Utilising a quantitative approach, structural equation modelling (SEM) is employed to analyse data collected from 227 SMEs in sectors including sustainable agriculture, eco-friendly consumer goods, special woven fabrics, organic food and beverages, green fashion and textiles, and health and wellness. Findings: The study reveals a significant association between institutional support and key aspects of green export readiness, green export activities, and green innovation. Moreover, mediating roles of green innovation, green export readiness, and green export activities are identified, elucidating their influence on the relationship between institutional support and green export strategy. Importantly, effective green export strategies positively impact export performance, enhancing SMEs’ competitive positioning in global markets. Originality: This research contributes novel insights into SMEs’ engagement in green export, shedding light on the critical role of institutional support and the mediating mechanisms that facilitate the adoption of successful green export strategies. Research limitations: One limitation of this study is the cross-sectional nature of the data, which restricts the ability to establish causal relationships. Future research could explore longitudinal data to further investigate the dynamics between institutional support, green export strategies, and export performance. Practical implications: The findings provide valuable insights for SMEs seeking to enhance their sustainability-driven international business practices. Managers can leverage institutional support and focus on developing green export strategies to improve their export performance and competitiveness in global markets. Social implications: By embracing green export strategies, SMEs can contribute to sustainable development goals and promote environmentally responsible practices in the global marketplace, thereby fostering positive social and environmental impacts. © The Author(s) 2024.
Integrated Spillover Effect of Cross-Listed Stock Markets on the Indian Equity Market
(School of Management Sciences, 2022) Aditya Keshari; Amit Gautam; Vishal Kumar Singh
The increased integration due to cross-listing leads to the volatility spillover effect on the domestic market posing from the cross-listed global indices viz., Nifty 50 from India, Luxx 100 from Luxembourg, NASDAQ from the US, and FTSE_Aim 100 from the UK. Johansen Co-integration test is applied to check the level of integration, which is further checked by multivariate granger causality showing the causality pattern among the indices. GARCH (1,1) model is applied to examine the volatility spillover effect on the Indian Stock Market. The findings suggest that the series are co-integrated with one vector ‘v,’ which is confirmed by the Trace and Max-Eigen Test. The Multivariate Granger Causality test confirms the bivariate causal pattern between India and US markets, implying the dual effect. In contrast, the Luxembourg market is relatively exogenous, which gives investors an opportunity for portfolio diversification. ARCH term is significant in the GARCH (1,1) model showing that the past innovation in the time series leads to the present fluctuation in the Indian stock market. Also, the results show a significant spillover effect from the US and UK markets. Thus, this will assist the investors that by concentrating on the movement of these markets, they can take specific actions regarding portfolio management. ©The Author(s).2021 Open Access.
Investigating the Relationship Between Export Antecedents and Export Performance of Handloom Industry
(Sage Publications India Pvt. Ltd, 2022) Vishal Kumar Singh; Amit Gautam
This study identified the export antecedents that could influence the occurrence of export performance of the industry. The export antecedents are the phenomenon that acts as a backend support system for effective export performance. This study aims to build a simple linear model representing the structural relationship between the export antecedents and export performance. The model building is based on the identified antecedents and attempts to reflect the combined gist of pre-established theories, that is, contingency theory, resource-based view and dynamic capabilities. In data interpretation, second-order confirmatory factor analysis (CFA) helps to analyse the combined impact of all studied antecedents on export performance. The identified antecedents are export knowledge, export perception, export commitment, export strategy and organizational capability as independent variables tested against the dependent variable export performance. © 2022 Fortune Institute of International Business.
Investigational new drugs for the treatment of leishmaniasis
(Taylor and Francis Ltd., 2024) Shyam Sundar; Vishal Kumar Singh; Neha Agrawal; Om Prakash Singh; Rajiv Kumar
Introduction: Over the past 20 years, significant progress has been made in anti-leishmanial therapy. Three new drugs/formulations are available for the treatment of various forms of leishmaniasis, namely oral miltefosine, paromomycin and liposomal amphotericin B. However, these advances in drug development have added considerable complexity for clinicians including toxicity, emergence of resistance and decreased sensitivity of available drugs. The development of newer drugs with less toxicity and more efficacy is urgently needed. Areas covered: This review comprehensively examines the latest developments and current status of antileishmanial drugs for the treatment of leishmaniasis across the world. Several new investigational drugs that showed anti-leishmanial activity under in vitro or in vivo conditions and either underwent the phase-I/II clinical trials or are on the verge of entering the trials were reviewed. We also delve into the challenges of drug resistance and discuss the emergence of new and effective antileishmanial compounds. Expert opinion: The available treatments for leishmaniasis are limited in number, toxic, expensive, and demand extensive healthcare resources. Every available antileishmanial drug is associated with several disadvantages, such as drug resistance and toxicity or high cost. Miltefosine is potentially teratogenic. New antileishmanial drugs/treatment modalities are sorely needed for expanding future treatment options. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Mediating effect of export commitment on the relationship of export knowledge and performance: a study of indian handloom industry
(School of Management Sciences, 2021) Vishal Kumar Singh; Amit Gautam
In this study, the determinants export knowledge and commitment were identified from the earlier literature, and their impact on the dependent variable export performance is being evaluated. The primary objective has been to create a linear model that depicts the structural link between the identified factors and the export performance. To achieve this objective, first-order confirmatory factor analysis with regression aids in data interpretation has been conducted by analysing the influence of variables on export performance. The independent variable export knowledge is used to examine the relationship with the dependent variable export performance in the presence of mediating variable, export commitment. The study found that knowledge influences the export performance significantly, but export commitment, as a mediator, intensifies the indirect relationship between knowledge and performance. As a result, it can be stated that while export knowledge assists management in acquiring export-related information, export commitment drives management to put knowledge into practice and make the most use of available resources to positively influence the export performance. © The Author(s).
MHC tetramer technology: Exploring T cell biology in health and disease
(Academic Press Inc., 2024) Rahul Tiwari; Vishal Kumar Singh; Rajneesh; Awnish Kumar; Vibhav Gautam; Rajiv Kumar
Major histocompatibility complex (MHC) tetramers stand as formidable tools within T cell biology, facilitating the exploration and comprehension of immune responses. These artificial molecules, comprising four bound MHC molecules, typically with a specified peptide and a fluorescent label, play a pivotal role in characterizing T cell subsets, monitoring clonal expansion, and unraveling T cell dynamics during responses to infections or immunotherapies. Beyond their applications in T cell biology, MHC tetramers prove valuable in investigating a spectrum of diseases such as infectious diseases, autoimmune disorders, and cancers. Their instrumental role extends to vaccine research and development. Notably, when appropriately configured, tetramers transcend T cell biology research and find utility in exploring natural killer T cells and contributing to specific T cell clonal deletions. © 2024
MicroRNAs-mediated regulation of immune responses in parasitic infection
(Elsevier, 2024) Ritirupa Roy; Prasoon Madhukar; Vishal Kumar Singh; Rahul Tiwari; Awnish Kumar; Rajneesh; Madhukar Rai; Vibhav Gautam; Shyam Sundar; Rajiv Kumar
Leishmaniasis is a group of diseases that predominantly affect impoverished individuals in developing regions. Recent research has highlighted the significant role of microRNAs (miRNAs), small noncoding RNA molecules, in regulating gene expression and contributing to disease pathogenesis in leishmaniasis. Understanding the intricate miRNA-mediated interactions provides valuable insights into the underlying mechanisms of leishmaniasis and facilitates the development of targeted interventions. Moreover, miRNAs demonstrate altered expression levels, and their presence in the bloodstream enables noninvasive detection, making them promising biomarker candidates for diagnosis and prognosis. This chapter focuses on the role of miRNAs in regulating the immune response during leishmania infection, emphasizing their potential as both biomarkers and therapeutic targets. © 2024 Elsevier Inc. All rights reserved.
Nanomedicine in Cardiovascular Diseases: Diagnostic and Therapeutic Innovations for Better Health
(Springer Science and Business Media B.V., 2024) Prasoon Madhukar; Vishal Kumar Singh; Shashi Bhushan Chauhan; Rahul Tiwari; Awnish Kumar; Rajneesh; Rajiv Kumar
Cardiovascular diseases (CVDs) are a major cause of global mortality, responsible for approximately 17.9 million deaths in 2019 and 20.5 million deaths in 2021. Limited access to specialised testing, especially for marginalised population, complicate the diagnosis of cardiovascular conditions. Disparities in treatment, sub-optimal pharmaceuticals, toxicity from conventional drugs, diagnostic errors, and the underutilization of non-invasive diagnostic methods contribute to adverse outcomes. Additionally, cost and insurance barriers hinder access to necessary tests, delaying diagnosis and treatment. Therefore, there is an urgent need for improved therapies for CVDs. Additionally, cost and insurance barriers hinder access to necessary tests, delaying diagnosis and treatment. Therefore, there is an urgent need for improved therapies for CVDs. Nanotechnology, which involves the precise control and manipulation of materials at the atomic and molecular levels, shows promise in addressing cardiovascular diseases. Nanoparticles, with their unique properties such as ultra-small size, tunable physicochemical characteristics, and biocompatibility, offer potential for targeted drug delivery. Nanoparticle-based drug delivery systems can enhance therapeutic effectiveness, prolong drug action, improve drug absorption, target specific areas passively or actively, reduce drug resistance, and minimize adverse drug reactions. This chapter comprehensively examines the use of nanoparticle-based diagnostic methods, targeting strategies, and therapeutic interventions for cardiovascular diseases, providing a thorough explanation of the fundamental principles and key considerations in this field. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
Post kala-azar dermal leishmaniasis in the Indian sub-continent: challenges and strategies for elimination
(Frontiers Media SA, 2023) Awnish Kumar; Vishal Kumar Singh; Rahul Tiwari; Prasoon Madhukar; Rajneesh; Shashi Kumar; Vibhav Gautam; Christian Engwerda; Shyam Sundar; Rajiv Kumar
Visceral leishmaniasis (VL) is a severe and often fatal form of leishmaniasis caused by Leishmania donovani in the Indian sub-continent. Post Kala-azar Dermal Leishmaniasis (PKDL) is a late cutaneous manifestation of VL, typically occurring after apparent cure of VL, but sometimes even without a prior history of VL in India. PKDL serves as a significant yet neglected reservoir of infection and plays a crucial role in the transmission of the disease, posing a serious threat to the VL elimination program in the Indian sub-continent. Therefore, the eradication of PKDL should be a priority within the current VL elimination program aimed at achieving a goal of less than 1 case per 10,000 in the population at the district or sub-district levels of VL endemic areas. To accomplish this, a comprehensive understanding of the pathogenesis of PKDL is essential, as well as developing strategies for disease management. This review provides an overview of the current status of diagnosis and treatment options for PKDL, highlighting our current knowledge of the immune responses underlying disease development and progression. Additionally, the review discusses the impact of PKDL on elimination programs and propose strategies to overcome this challenge and achieve the goal of elimination. By addressing the diagnostic and therapeutic gaps, optimizing surveillance and control measures, and implementing effective intervention strategies, it is possible to mitigate the burden of PKDL and facilitate the successful elimination of VL in the Indian sub-continent. Copyright © 2023 Kumar, Singh, Tiwari, Madhukar, Rajneesh, Kumar, Gautam, Engwerda, Sundar and Kumar.
The development and maintenance of immunity against visceral leishmaniasis
(Frontiers Media SA, 2024) Rahul Tiwari; Awnish Kumar; Vishal Kumar Singh; Rajneesh; Shashi Bhushan Chauhan; Shyam Sundar; Susanne Nylén; Christian Engwerda; Rajiv Kumar
Understanding the development and maintenance of immunological memory is important for efforts to eliminate parasitic diseases like leishmaniasis. Leishmaniasis encompasses a range of pathologies, resulting from infection with protozoan parasites belonging to the subgenera Leishmania and Viannia of the genus Leishmania. A striking feature of these infections is that natural or drug-mediated cure of infection generally confers life-long protection against disease. The generation of protective T cell responses are necessary to control Leishmania infections. CD4+ T helper (Th) cells orchestrate immune responses in leishmaniasis and IFNγ+ Tbet+ CD4+ T (Th1) cells are required for the activation of phagocytes to kill captured or resident parasites, while other Th cell subset, including FoxP3+ natural regulatory T cells and Th2 cells can promote disease progression by suppressing the activities of Th1 cells. Upon resolution of a primary Leishmania infection, different subsets of CD4+ T cells, including tissue-resident memory T cells, effector memory T cells, central memory T cells, and short-lived effector T cells, help to confer resistance against reinfection. To maintain long-term protective Leishmania-specific CD4+ T cells responses, it is believed that persistent parasites or re-exposure to parasites at regular intervals is required (concomitant immunity). Despite the advances in our understanding about the immune responses during leishmaniasis, the generation of long-lasting protective immunity via vaccination has yet to be achieved. In this review, we summarize our current understanding about the formation and maintenance of immunological memory and control of leishmaniasis at the individual and population level. We will focus on Indian visceral leishmaniasis and discuss T cell responses that contribute to susceptibility to leishmaniasis, parasite persistence in populations and the environment, as well as describing advances in the development of leishmaniasis vaccines aimed at inducing protective CD4+ T cell responses. Copyright © 2024 Tiwari, Kumar, Singh, Rajneesh, Chauhan, Sundar, Nylén, Engwerda and Kumar.