Gaurav Nagar | Wright State University (original) (raw)

Papers by Gaurav Nagar

Ticks and Tick-borne Diseases, 2021

Journal of Helminthology, Jul 21, 2009

An adult stage Opisthorchis viverrini cDNA library was constructed and screened for abundant tran... more An adult stage Opisthorchis viverrini cDNA library was constructed and screened for abundant transcripts. One of the isolated cDNAs was found by sequence comparison to encode a glutathione S-transferase (GST) and was further analyzed for RNA expression, encoded protein function, tissue distribution and cross-reactivity of the encoded protein with other trematode protein counterparts. The cDNA has a size of 893 bp and encodes a GST of 213 amino acids length (OV28GST). The most closely-related GST of OV28GST among those published for trematodes is a 28 kDa GST of Clonorchis sinensis as shown by multiple sequence alignment and phylogenetic analysis. Northern analysis of total RNA with a gene-specific probe revealed a 900 nucleotide OV28GST transcriptional product in the adult parasite. Through RNA in situ hybridization OV28GST RNA was detected in the parenchymal cells of adult parasites. This result was confirmed by immunolocalization of OV28GST with an antiserum generated in a mouse against bacterially-produced recombinant OV28GST. Both, purified recombinant and purified native OV28GST were resolved as 28 kDa proteins by SDS-PAGE. Using the anti-recOV28GST antiserum, no or only weak cross-reactivity was observed in an immunoblot of crude worm extracts against the GSTs of Schistosoma mansoni, S. japonicum, S. mekongi, Eurytrema spp. and Fasciola gigantica. The enzyme activity of the purified recombinant OV28GST was verified by a standard 1-chloro-2, 4-dinitrobenzene (CDNB) based activity assay. The present results of our molecular analysis of OV28GST should be helpful in the ongoing development of diagnostic applications for opisthorchiasis viverrini.

Paediatrics and Child Health, Jun 1, 2014

BACK TO TABLE OF CONTENTS only; Gp2 with umbilical artery (UA) lines only; and Gp3 with both UA a... more BACK TO TABLE OF CONTENTS only; Gp2 with umbilical artery (UA) lines only; and Gp3 with both UA and UV lines. Data fields included demographics, peripartum factors, major inpatient morbidities (nosocomial infection (NI), necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD), brain injury (BI) and retinopathy of prematurity (ROP)), and mortality. Univariable and multivariable regression analyses were performed to compare the four groups. rESultS: Of 4623 babies 820 (17.7%) were in Gp0, 1032 (22.3%) in Gp1, 120 (2.6%) in Gp2, and 2651 (57.3%) in Gp3. With increasing number of lines babies were smaller, had lower Apgar scores, were more likely to have high SNAPII scores, and were more likely to be born by Cesarean Section. Univariate analysis showed that babies with no umbilical lines (Gp0) had the lowest mortality and lowest rates of NI, NEC, BPD, BI, and ROP. Increasing from one to two lines also increased rates. After adjustment for risk factors (see table and footnote) babies with no lines had significantly lower rates of a composite outcome of death or major inpatient morbidity-there was no difference in mortality between groups. Similar results were obtained when the model was adjusted for SNAPII instead of Apgar score. CoNCluSIoNS: Most very preterm babies in Canada get UA and/or UV lines (usually both). Umbilical lines are more likely to be inserted into smaller, sicker babies. However, after adjustment for risk factors and acuity, babies with no umbilical lines are more likely to survive without major morbidity. Adding a second umbilical line appears to increase risk further. Clinical strategies should take into account the inherent risks of UA and/ or UV lines. Alternative practices, such as early placement of peripherally inserted central catheters, require further evaluation.

Parasitology Research, Jul 13, 2011

Fasciola gigantica, causative agent of tropical fasciolosis, inflicts substantial economic losses... more Fasciola gigantica, causative agent of tropical fasciolosis, inflicts substantial economic losses on the livestock industry, affecting severely buffalo productivity in the tropical countries. Very few vaccination trials with different target antigens against F. gigantica infection have been conducted in this host. Present study describes a vaccination trial in buffaloes with F. gigantica recombinant glutathione S-transferase and fatty acid binding protein. The two recombinant proteins were expressed in Escherichia coli and evaluated for their immunoprophylactic potential in buffalo calves, using montanide 70 M-VG, a mineral oil-based adjuvant, for delivering the antigens. Buffalo calves were distributed in three groups, with group I, II and III calves immunized with recombinant glutathione S-transferase, fatty acid binding protein and a cocktail of these two antigens, respectively. Immunization of the calves evoked a mixed IgG1 and IgG2 antibody response. Present vaccination trial in these animals achieved a maximum protection level of 35%, when the two antigens were used in combination. Eosinophils were measured in both immunized and non-immunized challenge control animals, which showed a steady increase in their count in response to immunization with both the antigens and infection with F. gigantica, respectively.

Ticks and Tick-borne Diseases

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1991

Cereal Chem. 75(4):473-479 Homogeneous barley limit dextrinase (LD) was isolated on a large scale... more Cereal Chem. 75(4):473-479 Homogeneous barley limit dextrinase (LD) was isolated on a large scale in a yield of 9 mg/kg of 10-day germinated green malt. This represents a 9,400-fold purification and 29% recovery of the activity in a flour extract in 0.2M NaOAc (pH 5.0) containing 5 mM ascorbic acid. The purification protocol consists of precipitation from the extract at 20-70% saturated ammonium sulfate (AMS), followed by diethylaminoethyl (DEAE) 650S Fractogel anion-exchange chromatography, and affinity chromatography on β-cyclodextrin-Sepharose in the presence of 2M AMS. LD was eluted by 7 mM β-cyclodextrin and contains a single polypeptide chain of 105 kDa (SDS-PAGE) and pI 4.3. Sequence analysis of tryptic fragments, prepared from 2-vinylpyridinylated LD and purified by RP-HPLC, identified short motifs recognized in β-strand 2, 3, and 5 characteristic of a catalytic (β/α) 8-barrel domain of the α-amylase family of amylolytic enzymes. Barley LD has ≈50 and 85% sequence identity to bacterial pullulanases and rice starch debranching enzyme, respectively. By using 1 H-NMR spectroscopy, LD hydrolyzes specifically α-1,6-glucosidic linkages in pullulan and a branched oligodextrin, 6 2-O-α-maltotriosyl-maltotriose, with retention of the α-anomeric configuration. β-Cyclodextrin competitively inhibits the LD activity with K i of 40 µM, while K i is 1.9 mM and 2.4 mM for αcyclodextrin and γ-cyclodextrin, respectively.

Indian Pediatrics, Apr 1, 2006

Objective: A secular trend towards increased current and lifetime asthma prevalence has been obse... more Objective: A secular trend towards increased current and lifetime asthma prevalence has been observed in the US. The current study compared ambient Air Quality Index (AQI) data and asthma prevalence data from all fifty US states. Methods: Air pollution is measured as AQI by the US Environmental Protection Agency (EPA). County level AQI data are available at the EPA website. Asthma prevalence data for each state are available on the Centers for Disease Control and Prevention (CDC) website. Data from 50 US states (2011-2013) were analyzed for AQI and asthma prevalence. The average of proportions for all counties in each state was used to obtain a mean value for good air quality days ("Good Days") in each year. An Analysis of Variance (ANOVA) was conducted to evaluate if 1) asthma prevalence and 2) AQI differences across 2011, 2012 and 2013. A regression analysis was conducted to assess the association between AQI and asthma prevalence. Results: The analysis showed a reduction in air pollution from 2011 to 2013. The ANOVA revealed that this decrease in AQI was significant, F (2, 147) = 5.7678, p = 0.0039. While an increase in asthma prevalence was observed from 2011 to 2013,the ANOVA revealed that the increased asthma prevalence was not significant, F (2, 147) = 0.2794, p = 0.7566. Regression analysis showed no significant association between AQI and asthma prevalence (p>0.05). Conclusion: US Asthma prevalence did not change significantly despite significant AQI reduction from 2011 to 2013; AQI was not related to asthma prevalence.

International Journal of Advance Research and Innovation, 2016

Food safety is a global health concern. Food is one of the major sources of microbial pathogens i... more Food safety is a global health concern. Food is one of the major sources of microbial pathogens in the developing regions. Food borne diseases or infections have increased over a year and ultimately resulted into severe health problems. Different type of food borne infections is detected by different type of microbes or pathogens contaminating the food items. Therefore, it is required to detect the pathogens in foods and recognition of problems associated with health and safety. Hence, variety of techniques has already been developed to detect food borne pathogens or microbes as it is important in analysing the food samples. The detection of food borne pathogens by conventional methods is time consuming, tedious and laborious whereas rapid methods are time efficient, sensitive and much more specific. In general, these techniques play a vital role in preventing and treating the food borne diseases. The aim of this comprehensive literature is to give an overview in the field of food borne pathogen detection.

INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH, 2021

Pelvic Inammatory disease also is an infection of upper part of female reproductive system. This... more Pelvic Inammatory disease also is an infection of upper part of female reproductive system. This article deals with an overview of Pelvic Inammatory disease, focusing upon its various aspects along with Homoeopathic management of the same.

Pathogens

The immunoprophylactic management of ticks is the most effective option to control tick infestati... more The immunoprophylactic management of ticks is the most effective option to control tick infestations and counter spread the acaricide resistance problem worldwide. Several researchers reported an inconsistent efficacy of the single antigen-based immunization of hosts against different tick species. In the present study, to develop a multi-target immunization protocol, proteins from Rhipicephalus microplus BM86 and Hyalomma anatolicum subolesin (SUB) and tropomyosin (TPM) were targeted to evaluate the cross-protective potential. The sequence identities of the BM86, SUB, and TPM coding genes amongst Indian tick isolates of targeted species were 95.6–99.8%, 98.7–99.6%, and 98.9–99.9%, respectively, while at the predicted amino acid level, the identities were 93.2 to 99.5, 97.6 to 99.4, and 98.2 to 99.3%. The targeted genes were expressed in the eukaryotic expression system, pKLAC2-Kluyveromyces lactis, and 100 µg each of purified recombinant protein (Bm86-89 kDa, SUB-21 kDa, and TPM-36...

Science Advances

Authorized vaccines against SARS-CoV-2 remain less available in low- and middle-income countries ... more Authorized vaccines against SARS-CoV-2 remain less available in low- and middle-income countries due to insufficient supply, high costs, and storage requirements. Global immunity could still benefit from new vaccines using widely available, safe adjuvants, such as alum and protein subunits, suited to low-cost production in existing manufacturing facilities. Here, a clinical-stage vaccine candidate comprising a SARS-CoV-2 receptor binding domain–hepatitis B surface antigen virus–like particle elicited protective immunity in cynomolgus macaques. Titers of neutralizing antibodies (>104) induced by this candidate were above the range of protection for other licensed vaccines in nonhuman primates. Including CpG 1018 did not significantly improve the immunological responses. Vaccinated animals challenged with SARS-CoV-2 showed reduced median viral loads in bronchoalveolar lavage (~3.4 log10) and nasal mucosa (~2.9 log10) versus sham controls. These data support the potential benefit of...

Paediatrics and Child Health, 2015

There is a continued need for sarbecovirus vaccines that can be manufactured and distributed in l... more There is a continued need for sarbecovirus vaccines that can be manufactured and distributed in low- and middle-income countries (LMICs). Subunit protein vaccines are manufactured at large scales at low costs, have less stringent temperature requirements for distribution in LMICs, and several candidates have shown protection against SARS-CoV-2. We previously reported an engineered variant of the SARS-CoV-2 Spike protein receptor binding domain antigen (RBD-L452K-F490W; RBD-J) with enhanced manufacturability and immunogenicity compared to the ancestral RBD. Here, we report a second-generation engineered RBD antigen (RBD-J6) with two additional mutations to a hydrophobic cryptic epitope in the RBD core, S383D and L518D, that further improved expression titers and biophysical stability. RBD-J6 retained binding affinity to human convalescent sera and to all tested neutralizing antibodies except antibodies that target the class IV epitope on the RBD core. K18-hACE2 transgenic mice immuni...

Indian Journal of Animal Sciences, 2016

Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum are the most common tick species infe... more Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum are the most common tick species infesting milk and meat producing animals throughout the country. The present study was conducted to evaluate the acaricide resistance status of the tick species to deltamethrin, cypermethrin, diazinon collected from 10 districts of Rajasthan. Characterization of resistance was carried out by adult immersion test (AIT) and larval packet test (LPT). In case of R. (B.) microplus resistance to deltamethrin at level I (RF = 2.5 – 4.9) in 02 isolates, at level II in 03 isolates (RF = 5.4 – 11.5) and level IV in 02 isolates (RF = 48.1 – 95.7) was detected. The resistance to cypermethrin was detected in 08 isolates of which resistance at level I in 03 isolates (RF = 2.7 - 4.58) and at level II in 05 isolates (RF = 8.05 – 16.2). Diazinon resistance was detected at level II in 06 isolates (RF = 5.8 –22.8), at level III in 01 isolates (RF = 39.0) and level IV in 02 isolates (RF = 65.9 – 66.0). While i...

Experimental and Applied Acarology, 2021

The resistance status against deltamethrin, cypermethrin, coumaphos and ivermectin was assessed o... more The resistance status against deltamethrin, cypermethrin, coumaphos and ivermectin was assessed of Rhipicephalus microplus from five districts of Uttarakhand, through adult immersion test and larval packet test. The field isolates were highly resistant to deltamethrin (median resistance ratio [RR50] = 9.10-29.13-fold) followed by cypermethrin (2.23-3.55). Surprisingly the isolates were susceptible to coumaphos (0.34-3.17). Emerging resistance against ivermectin (1.55-3.27) was also observed in all the isolates. Elevated levels of esterases (enzyme ratio = 2.93-5.84-fold), glutathione S-transferases (5.10-10.06) and monooxygenases (1.68-4.02) in resistant fields isolates were highly correlated (47.4-86.0%) with the resistant factor (RR50) determined by bioassay. All the isolates except Uttarkashi possess mutation at the 190th position in domain II of the sodium channel gene. As a mitigation strategy an Ageratum conyzoides-based characterized natural formulation was tested against all the isolates and was found effective at the concentration of 10.1-11.5%. The possibility of using the natural formulation for the management of multi-acaricide resistant ticks is discussed.

Paediatrics and Child Health, 2014

BACkGrouND: NEC remains a major cause of morbidity and mortality in very low birth weight infants... more BACkGrouND: NEC remains a major cause of morbidity and mortality in very low birth weight infants. Surgery is required in a third of cases, however randomised trials have shown no difference in early mortality of NEC managed with laparotomy versus peritoneal drain. oBjECtIvES: To compare short term outcomes and neurological morbidities of infants with NEC treated by laparotomy or peritoneal drain. DESIGN/MEtHoDS: Retrospective multicenter study on infants <33 weeks' gestation born between January 2010 and December 2012 with NEC Stage II or greater, using Canadian Neonatal Network data. Infants were stratified by medical and surgical treatments. Significant difference between group outcomes was assessed using the Pearson χ 2 test for categorical variables and Student's t test for continuous variables. Odds ratios with 95% CIs) were calculated using standard methods. rESultS: A total of 11,974 infants were admitted to 30 CNN NICUs during the study period and 214 of NEC cases (39%) required surgery. Seventy infants were treated with drain or drain and laparotomy; they had significantly lower birth weights and gestational ages, P<0.0001 and higher mortality P<0.001 than the laparotomy group. Both medical and surgical NEC infants had significantly greater rates of IVH and PVL (P<0.0001) compared to no NEC infants with decreased head growth at 36 weeks, (P<0.05). However, there was no difference in adjusted head growth at 36 weeks between those treated with drain or laparotomy at 36 weeks (−0.82 [95% CI −2.40 to 0.77], P=0.30). CoNCluSIoNS: In contrast to previous studies, we show mortality in the peritoneal drain group is higher. Longer-term neurodevelopmental outcomes will be important to determine best practice.

International Journal of Tropical Insect Science

Monitoring of acaricide resistance and identification of resistance mechanisms are two important ... more Monitoring of acaricide resistance and identification of resistance mechanisms are two important facets of sustainable tick control. To identify the role of specific esterases in development of acaricide resistance, a comparative analysis of the esterase (EST) patterns was made in four reference Rhipicephalus (Boophilus) microplus tick populations i.e. susceptible (IVRI-1), diazinon resistant (IVRI-III), deltamethrin resistant (IVRI-IV) and multi-acaricide resistant (IVRI-V) and in different field isolates, using non-denaturing polyacrylamide gel electrophoresis. Comparative profiling of esterases exhibited higher intensities of EST-1, EST-3 and EST-4 bands in resistant lines and in resistant field isolates in comparison to IVRI-I line. Non inhibition of EST-1 with acetylcholinesterase inhibitor, eserine sulphate and increase in EST-1 band intensity with the inhibition of EST-2 in the resistant lines and isolates suggests the possible role of EST-1 in resistance development. The fin...