Browsing by Author "Vijay P. Singh"

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A cluster of cases of severe cardiotoxicity among kala-azar patients treated with a high-osmolarity lot of sodium antimony gluconate
(American Society of Tropical Medicine and Hygiene, 1998) Shyam Sundar; Prabhat R. Sinha; Nutan K. Agrawal; Rakesh Srivastava; Petrie M. Rainey; Jonathan D. Berman; Henry W. Murray; Vijay P. Singh
In India, sodium antimony gluconate is the drug of choice for kala- azar. Due to increasing unresponsiveness to this drug in the current epidemic that began in the early 1970s, daily doses of 20 mg/kg/day for 30 days or more is recommended as opposed to the 10 mg/kg/day dose for 6-10 days used in the past. Of the 130-150 patients treated annually at our center with locally made sodium antimony gluconate, serious cardiotoxicity has occurred in less than 10%. During April 1995 at the University Hospital in Varanasi, we encountered life- threatening caxdiotoxicity after 3-28 days of therapy in each of the eight patients being treated with a new lot of this drug made by a different manufacturer. Of the eight patients, six each developed congestive heart failure and/or prolongation of the corrected QT interval (QTc), and three died as a direct consequence of drug-induced toxicities. In three instances, the life-threatening complications occurred with a cumulative dose of less than 300 mg/kg. In patients with prolonged QTc, ventricular premature beats and ventricular tachycardia were recorded; in one patient, the ventricular tachycardia progressed to torsade de pointes, culminating in ventricular fibrillation and death. Since switching to different lots of this drug, we have not seen further clustering of dangerous cardiotoxicity. The antimony content of the implicated drug was comparable with that in lots from other manufacturers that did not show overt toxicity, but the osmolarity was approximately 300 mOsm/L higher. The simple technique of measuring of osmolarity may help identify inappropriately manufactured drug.
A generalised hydrological model for streamflow prediction using wavelet Ensembling
(Elsevier B.V., 2025) Chinmaya Panda; Kanhu Charan Panda; Ramesh Mandir Singh; Ram Baran Singh; Vijay P. Singh
Machine learning (ML) models have recently been employed for precise streamflow prediction. These ML models, however, suffer from overfitting, non-scalability, non-transferability, and low predictive accuracy when used for unseen data that have high spatiotemporal variability and heterogeneity. To overcome these problems, a generalised streamflow model was, therefore, developed using novel Wavelet Ensembling (WE). The WE models were tested for several predictor combinations encompassing various terrain and flow conditions and were compared with the standalone and ensemble ML models. The generalisability of the models employed in the study was tested using transfer learning-based leave-one-out cross-validation (LOOCV). It was found that the WE models demonstrated a significant improvement over the standalone and ensemble ML models. The genetic algorithm (GA) optimised RF-based WE model (WE-RF-GA) was found to be the most efficient and generalised model, having the highest efficiency (NSE = 0.94, R2 = 0.95) and the lowest error (RMSE = 0.038, MAE = 0.028). The standalone and ensemble models showed higher predictive accuracy for tributaries, plain topography, and low-flow conditions compared to the mainstream flow, hilly terrain, and high-flow values. The WE models significantly reduced the performance gap of these models for the aforementioned conditions. This study would further enhance streamflow models and help predict streamflow effectively for data-scarce and ungauged basins. © 2025 Elsevier B.V.
Acquisition and homeostasis of Iron in higher plants and their probable role in abiotic stress tolerance
(Frontiers Media S.A., 2018) Durgesh K. Tripathi; Shweta Singh; Shweta Gaur; Swati Singh; Vaishali Yadav; Shiliang Liu; Vijay P. Singh; Shivesh Sharma; Prateek Srivastava; Sheo M. Prasad; Nawal K. Dubey; Devendra K. Chauhan; Shivendra Sahi
Iron (Fe) is a micronutrient that plays an important role in agriculture worldwide because plants require a small amount of iron for its growth and development. All major functions in a plant's life from chlorophyll biosynthesis to energy transfer are performed by Fe (Brumbarova et al., 2008; Gill and Tuteja, 2011). Iron also acts as a major constituent of many plant proteins and enzymes. The acquisition of Fe in plants occurs through two strategies, i.e., strategy I and strategy II (Marschner and Römheld, 1994). Under various stress conditions, Nramp and the YSL gene families help in translocation of Fe, which further acts as a mineral regulatory element and defends plants against stresses. Iron plays an irreplaceable role in alleviating stress imposed by salinity, drought, and heavy metal stress. This is because it activates plant enzymatic antioxidants like catalase (CAT), peroxidase, and an isoform of superoxide dismutase (SOD) that act as a scavenger of reactive oxygen species (ROS) (Hellin et al., 1995). In addition to this, their deficiency as well as their excess amount can disturb the homeostasis of a plant's cell and result in declining of photosynthetic rate, respiration, and increased accumulation of Na+ and Ca- ions which culminate in an excessive formation of ROS. The short-range order hydrated Fe oxides and organic functional groups show affinities for metal ions. Iron plaque biofilm matrices could sequester a large amount of metals at the soil-root interface. Hence, it has attracted the attention of plant physiologists and agricultural scientists who are discovering more exciting and hidden applications of Fe and its potential in the development of bio-factories. This review looks into the recent progress made in putting forward the role of Fe in plant growth, development, and acclimation under major abiotic stresses, i.e., salinity, drought, and heavy metals. © 2018 Tripathi, Singh, Gaur, Singh, Yadav, Liu, Singh, Sharma, Srivastava, Prasad, Dubey, Chauhan and Sahi.
Analytical solution of advection-dispersion equation with spatially dependent dispersivity
(American Society of Civil Engineers (ASCE), 2017) Vinod Kumar Bharati; Vijay P. Singh; Abhishek Sanskrityayn; Naveen Kumar
In the dispersion theory of solute transport in groundwater flow, the dispersion coefficient is regarded as proportional to the nth power of groundwater velocity, where n varies from 1 to 2. The present study derives an analytical solution of a one-dimensional (1D) advection-dispersion equation (ADE) for solute transport for any permissible value of n. For a nonhomogeneous medium, groundwater velocity is considered as a linear function of space and analytical solutions are obtained for n = 1, 1.5, and 2.0. For n = 1, the dispersivity (ratio of dispersion coefficient and velocity) remains uniform, representing a homogeneous medium, while it varies with position in the finite domain (aquifer) for any other permissible value of n representing the heterogeneity of the medium. From a hydrological point of view, the derived solutions are of significant interest and are of value in the validation of numerical codes. A generalized integral transform technique (GITT) with a new regular Sturm-Liouville problem (SLP) is used to derive analytical solutions in a finite domain. The analytical solutions elucidate the important features of solute transport with Dirichlet-type nonhomogeneous and homogeneous conditions assumed at the origin and at the far end of the finite domain, respectively. The first condition expresses a uniform continuous source of the dispersing mass. The analytical solutions are also compared with numerical solutions and are found to be in perfect agreement. The effect of a Peclet number on the solute concentration pattern is also investigated. © 2017 American Society of Civil Engineers.
Analytical solution of two-dimensional advection–dispersion equation with spatio-temporal coefficients for point sources in an infinite medium using Green’s function method
(Springer Netherlands, 2018) Abhishek Sanskrityayn; Vijay P. Singh; Vinod Kumar Bharati; Naveen Kumar
In the present study analytical solutions of a two-dimensional advection–dispersion equation (ADE) with spatially and temporally dependent longitudinal and lateral components of the dispersion coefficient and velocity are obtained using Green’s Function Method (GFM). These solutions describe solute transport in infinite horizontal groundwater flow, assimilating the spatio-temporal dependence of transport properties, dependence of dispersion coefficient on velocity, and the particulate heterogeneity of the aquifer. The solution is obtained in the general form of temporal dependence and the source term, from which solutions for instantaneous and continuous point sources are derived. The spatial dependence of groundwater velocity is considered non-homogeneous linear, whereas the dispersion coefficient is considered proportional to the square of spatial dependence of velocity. An asymptotically increasing temporal function is considered to illustrate the proposed solutions. The solutions are validated with the existing solutions derived from the proposed solutions in three special cases. The effect of spatially/temporally dependent heterogeneity on the solute transport is also demonstrated. To use the GFM, the ADE with spatio-temporally dependent coefficients is reduced to a dispersion equation with constant coefficients in terms of new position variables introduced through properly developed coordinate transformation equations. Also, a new time variable is introduced through a known transformation. © 2018, Springer Science+Business Media B.V., part of Springer Nature.
Analytical solutions for solute transport from varying pulse source along porous media flow with spatial dispersivity in fractal & Euclidean framework
(Elsevier Ltd, 2018) Vinod Kumar Bharati; Vijay P. Singh; Abhishek Sanskrityayn; Naveen Kumar
In the present study analytical solutions of the advection dispersion equation (ADE) are obtained to describe the solute transport originating from a varying pulse source along a porous medium with spatial dispersivity in fractal and Euclidean frameworks. Darcy velocity is considered to be a linear non-homogeneous spatial function. The dispersion coefficient is assumed to be proportional to nth power of velocity, where n may take on a value from 1 to 2. Analytical solutions are obtained for three values of the index, n=1.0, 1.5 and 2.0. The heterogeneity of the porous medium is enunciated in the fractal for n=1.5 (a real value), for other two integer values it is described in the Euclidean framework. Extended Fourier series method (EFSM) is employed to obtain the analytical solutions in the form of extended Fourier series (EFS) in terms of first five non-trivial solutions of a Sturm–Liouville Problem (SLP). The time dependent coefficients of the series are obtained analytically using Laplace integral transform technique. The ordinary differential equation of the auxiliary system is considered to be different from that used in all the previous studies in which a similar method has been employed. It paved the way for the proposed analytical solutions. The solution in the fractal framework and that in the Euclidean framework for n=1.0 are novel. A varying pulse source at the origin is considered which is useful in estimating the rehabilitation pattern of a polluted domain. The proposed solutions exhibit all the important features of solute transport and are found in agreement the respective numerical solution in very close approximation.. © 2018
Echocardiographic evaluation of cardiac status in Indian visceral leishmaniasis patients
(2007) Rakesh Shrivastava; Prabhat R. Sinha; Vijay P. Singh; Shyam Sundar
Visceral leishmaniasis (VL) is endemic in many countries worldwide, including India. Globally, sodium stibogluconate (Sb) remains the cornerstone of therapy, except in some parts of India owing to increasing drug resistance. Although electrocardiographic changes associated with Sb therapy have been described, global cardiac function using tools such as colour Doppler echocardiography is less well studied. We evaluated the cardiac function of 14 newly diagnosed VL patients using two-dimensional M-mode and Doppler echocardiography. The evaluations were performed before, during and at the end of Sb therapy. Left ventricular function and dimensions remained within normal limits in all patients. Pericardial effusion was noted in four patients with heavy parasitaemia. Effusions were small, haemodynamically insignificant and resolved spontaneously. We conclude that pericardial effusion may occur in VL patients with heavy parasitaemia. © 2006 Royal Society of Tropical Medicine and Hygiene.
Failure of pentavalent antimony in visceral leishmaniasis in India: Report from the center of the Indian epidemic
(2000) Shyam Sundar; Deepak K. More; Manoj K. Singh; Vijay P. Singh; Sashi Sharma; Anand Makharia; Prasanna C. K. Kumar; Henry W. Murray
In India, 320 patients with visceral leishmaniasis (209 in the state of Bihar and 11 in the neighboring state of Uttar Pradesh) received identical pentavalent antimony (Sb) treatment. Sb induced long-term cure in 35% (95% confidence interval [CI], 28%-42%) of those in Bihar versus 86% (95% CI, 79%-93%) of those in Uttar Pradesh. In Bihar, the center of the Indian epidemic, traditional Sb treatment should be abandoned.
Nitric oxide ameliorates zinc oxide nanoparticles phytotoxicity in wheat seedlings: Implication of the ascorbate–glutathione cycle
(Frontiers Media S.A., 2017) Durgesh K. Tripathi; Rohit K. Mishra; Swati Singh; Samiksha Singh; Kanchan Vishwakarma; Shivesh Sharma; Vijay P. Singh; Prashant K. Singh; Sheo M. Prasad; Nawal K. Dubey; Avinash C. Pandey; Shivendra Sahi; Devendra K. Chauhan
The present study investigates ameliorative effects of nitric oxide (NO) against zinc oxide nanoparticles (ZnONPs) phytotoxicity in wheat seedlings. ZnONPs exposure hampered growth of wheat seedlings, which coincided with reduced photosynthetic efficiency (Fv/Fm and qP), due to increased accumulation of zinc (Zn) in xylem and phloem saps. However, SNP supplementation partially mitigated the ZnONPs-mediated toxicity through the modulation of photosynthetic activity and Zn accumulation in xylem and phloem saps. Further, the results reveal that ZnONPs treatments enhanced levels of hydrogen peroxide and lipid peroxidation (as malondialdehyde; MDA) due to severely inhibited activities of the following ascorbate–glutatione cycle (AsA–GSH) enzymes: ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase, and its associated metabolites ascorbate and glutathione. In contrast to this, the addition of SNP together with ZnONPs maintained the cellular functioning of the AsA–GSH cycle properly, hence lesser damage was noticed in comparison to ZnONPs treatments alone. The protective effect of SNP against ZnONPs toxicity on fresh weight (growth) can be reversed by 2-(4carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, and thus suggesting that NO released from SNP ameliorates ZnONPs toxicity. Overall, the results of the present study have shown the role of NO in the reducing of ZnONPs toxicity through the regulation of accumulation of Zn as well as the functioning of the AsA–GSH cycle. © 2017 Tripathi, Mishra, Singh, Singh, Vishwakarma, Sharma, Singh, Singh, Prasad, Dubey, Pandey, Sahi and Chauhan.
Ocular manifestations and human immunodeficiency virus retinopathy in patients with acquired immunodeficiency syndrome in North India
(2006) V. Satya Suresh Attili; Vijay P. Singh; A.V. Bhaskar Reddy; Datla V. Varma; Madhukar Rai; Kumar A. Gulati; Shyam Sundar
Aim: To evaluate the spectrum of eye diseases in patients with human immunodeficiency virus, with special reference to human immunodeficiency virus retinopathy and its risk factors. Methods: All patient with human immunodeficiency virus attending the Infectious Disease Clinic at Sir Sunderlal Hospital, Institute of Medical Sciences, Banaras Hindu University, India, between January 2001 and December 2003 were enrolled. All patients underwent a thorough eye examination. Patients with acquired immunodeficiency syndrome retinopathy were analysed separately for predisposing factors. The risk factors analysed were positive C-reactive protein, low CD4 levels, associated central nervous system infections, and other eye diseases. Statistical analysis was done using Medcalc version 7.5. Results: Of 460 analysable patients, 88 patients (19%) had some eye manifestations, and 54 patients had human immunodeficiency virus retinopathy. Univariate analysis disclosed that immunosuppression (CD4 levels, <20/μL), positive C-reactive protein, associated eye lesions, and any central nervous system pathology were significant risk factors for the development of human immunodeficiency virus/acquired immunodeficiency syndrome retinopathy. Conclusions: Human immunodeficiency virus could be a risk factor for retinopathy as a significant number of patients did not have any other findings or risk factors for the development of retinopathy. However, it would be premature to draw definitive conclusions about the risk factors, as the number of patients analysed was small. © 2006 Scientific Communications International Limited.
Rapid accurate field diagnosis of Indian visceral leishmaniasis
(Elsevier B.V., 1998) Shyam Sundar; Steven G. Reed; Vijay P. Singh; Prasanna C. K. Kumar; Henry W. Murray
Background. A firm diagnosis of visceral leishmaniasis (kala-azar) requires demonstration of the parasite in organ aspirates or tissue biopsy samples. The aim of this prospective study was to assess the diagnostic usefulness of non-invasive testing for antibody to the leishmanial antigen K39 by means of antigen-impregnated nitrocellulose paper strips adapted for use under field conditions. Methods. One drop of peripheral blood is applied to the nitrocellulose strip. Three drops of test buffer (phosphate-buffered saline plus bovine serum albumin) are added to the dried blood. The development of two visible bands indicates presence of IgG anti-K39. 323 consecutive patients with suspected kala-azar referred to two specialist units in India, and 25 healthy controls, provided fingerstick blood samples for the test. Spleen aspirates were taken from 250 patients. Findings. Kala-azar was confirmed by microscopy of spleen-aspirate smears in 127 patients. The K39 strip test was positive in all 127; the estimated sensitivity was therefore 100% (95% CI 98-100). Four patients had positive strip tests but negative aspirate smears; all four responded to treatment for leishmaniasis. 217 individuals, including the 25 healthy controls, 73 patients with malaria or tuberculosis, and 119 spleen-aspirate-negative patients who had presumed malaria or cirrhosis (79) or no final diagnosis (40), had negative strip-test results. None of the 119 aspirate-negative patients developed evidence of kala-azar during 3-6 months of follow-up. The estimated specificity of the strip test was 98% (95-100; 217/221). Interpretation. Detection of anti-K39 by immunochromatographic strip testing is a rapid and non-invasive method of diagnosing kala-azar, which has good sensitivity and specificity and is well suited for use in field conditions.
Renal cortical necrosis is a disappearing entity in obstetric acute kidney injury in developing countries: Our three decade of experience from India
(Taylor and Francis Ltd, 2015) Jai Prakash; Pragya Pant; Anil K. Singh; Shashidhar Sriniwas; Vijay P. Singh; Usha Singh
Rational: Obstetrical complications are the commonest causes of Renal Cortical Necrosis (RCN). However, the overall incidence of RCN in obstetric acute kidney injury in developing countries has been decreasing in recent years. Objective: The aim of this study was to evaluate the changing profile of RCN in obstetric AKI over the last three decades. Methods: This single center study included patients with biopsy proven renal cortical necrosis over a period of 32 years from 1982 to 2014. The diagnosis of RCN was suspected in patients with prolonged AKI (>4 weeks) with absolute anuria in the setting of hemorrhage, hypotension and sepsis; and was confirmed by renal biopsy. The changing pattern in the incidence, etiology and outcome of RCN in patients with obstetric AKI was compared in the three study periods, namely 1982-1991, 1992-2002 and 2003-2014. Results: Over a period of 32 years, RCN was diagnosed in 15/259(5.8%) cases of obstetric AKI. Diffuse and patchy cortical necrosis were noted in 8(53.3%) and 7(46.7%) patients, respectively. RCN occurred in 17%(11/65), 2.4%(3/125) and 1.44%(1/69) patients in 1982-1991, 1992-2002 and 2003-2014, respectively. Septic abortion was commonest cause of RCN in the first two study periods but no case was observed in last decade. The decrease in incidence of RCN over the three decades was statistically significant (p-value < 0.001). Maternal mortality decreased to zero in 2003-2014 from 72.7% in 1982-1991. Conclusions: The incidence of RCN in obstetric AKI in developing countries has declined low enough to label it as a disappearing entity. © 2015 Informa Healthcare USA, Inc.
Serum sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of patients with membranous nephropathy and focal and segmental glomerulosclerosis
(2016) Pragya Pant; R.G. Singh; Santosh K. Singh; Vijay P. Singh; Prodip K. Doley; M. Sivasankar
Diagnosis of membranous nephropathy (MN) and focal and segmental glomerulo- sclerosis (FSGS) needs a renal biopsy, which is an invasive procedure with potentially serious complications. Proteomics may be applied for the development of a biomarker for these diseases which will obviate the need of biopsy. Serum sodium dodecyl sulfate-polyacrylamide gel electro-phoresis (SDS-PAGE) analysis gives an idea of the various proteins with different molecular weights (MWs) in a given sample. This study was conducted to analyze proteins with different MWs in patients with MN and FSGS and to compare the two groups with regard to their protein profile. This was a comparative, experimental study performed from June 2013 to July 2014 in the Department of Nephrology, Sir Sunderlal Hospital, Banaras Hindu University, Varanasi. Twenty-three histologically diagnosed cases of primary MN and 25 cases of FSGS were included in the study. Patients were categorized as having mild, moderate, and severe proteinuria with 24 h urinary protein levels of <4, 4- 8 and ≥8 g/24 h, respectively. SDS-PAGE analysis was performed by the method of Laemmli and revealed a significantly higher number of patients with FSGS (80%) having a protein corresponding to 29 kDa MW, than those with MN (39.1%) (P = 0.004). Protein of 5 kDa MW was present in a significantly higher number of patients with moderate (80%) and severe (100%) proteinuria than those with mild proteinuria (25%) (P <0.001). Thus, protein of MW 29 kDa may be a marker for FSGS and needs further characterization. Similarly, 5 kDa protein, present in patients with moderate and severe proteinuria, might be either contributing to or be a marker of severe illness.