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Mondal R, Antony S, Gnanesh BN, Thanavendan G, Ravikumar G, Sreenivasa B, Doss GS, Vijayan K. A Protocol for Mitotic Metaphase Chromosome Count Using Shoot Meristematic Tissues of Mulberry Tree Species. Bio Protoc 2023; 13:e4643. [PMID: 38273895 PMCID: PMC10810318 DOI: 10.21769/bioprotoc.4643] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/24/2022] [Accepted: 02/21/2023] [Indexed: 01/27/2024] Open
Abstract
Studies on chromosomal status are a fundamental aspect of plant cytogenetics and breeding because changes in number, size, and shape of chromosomes determine plant physiology/performance. Despite its significance, the classical cytogenetic study is now frequently avoided because of its tedious job. In general, root meristems are used to study the mitotic chromosome number, even though the use of root tips was restricted because of sample availability, processing, and lack of standard protocols. Moreover, to date, a protocol using shoot tips to estimate chromosome number has not yet been achieved for tree species' germplasm with a large number of accessions, like mulberry (Morusspp.). Here, we provide a step-by-step, economically feasible protocol for the pretreatment, fixation, enzymatic treatment, staining, and squashing of meristematic shoot tips. The protocol is validated with worldwide collections of 200 core set accessions with a higher level of ploidy variation, namely diploid (2n = 2x = 28), triploid (2n = 3x = 42), tetraploid (2n = 4x = 56), hexaploid (2n = 6x = 84), and decosaploid (2n = 22x = 308) belonging to nine species of Morus spp. Furthermore, accession from each ploidy group was subjected to flow cytometry (FCM) analysis for confirmation. The present protocol will help to optimize metaphase plate preparation and estimation of chromosome number using meristematic shoot tips of tree species regardless of their sex, location, and/or resources.
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Affiliation(s)
- Raju Mondal
- Mulberry Tissue Culture Lab, Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, India
| | - Sreya Antony
- Mulberry Tissue Culture Lab, Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, India
| | | | - G. Thanavendan
- Mulberry Tissue Culture Lab, Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, India
| | - G. Ravikumar
- Mulberry Tissue Culture Lab, Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, India
| | - B.T. Sreenivasa
- Mulberry Tissue Culture Lab, Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, India
| | - Gandhi S. Doss
- Central Tasar Research & Training Institute, Ranchi, India
| | - K. Vijayan
- International Sericultural Commission, Central Silk Board, Bengaluru, Karnataka, India
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Senthilkumar K, Ravikumar G, Parthiban ABR. Status of Urinary shedders of Leptospires among cattle in Tamilnadu: Implications on zoonosis. Vet Ital 2022; 58. [PMID: 36586111 DOI: 10.12834/vetit.2478.16135.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 09/02/2021] [Indexed: 01/01/2023]
Abstract
Bovine leptospirosis causes jaundice, mastitis, infertility, abortion, and death of the animal. This research aimed to study the status of urinary shedders of pathogenic Leptospira among the cattle population and identify the infecting serogroup circulating in this region. A total of 305 blood and 305 urine samples were collected from organized farms (n = 44), individually housed animals (n = 81) and animals from the slaughterhouse (n = 180). Microscopic agglutination test was carried out to detect anti‑leptospiral antibodies. Dark‑field microscopic examination and culture of urine were done to detect and isolate the Leptospira. The isolated Leptospira were identified by cross‑agglutination test and gene sequencing. PCR and real‑time PCR were carried out to detect leptospiral genomic DNA in urine samples to detect the shedders. The anti‑leptospiral antibodies were detected in 6.2% of animals. The Leptospira genomic DNA was detected in 9.2% (28 of 305) of urine samples. Of the 28 Leptospira positive urine samples, 39.2% were from animals with clinical signs suggestive of leptospirosis and 60.8% Leptospira positive samples were from slaughterhouse animals. The Leptospira isolated were identified as Leptospira interrogans serogroup Sejroe and Hebdomadis. The present study demonstrates the need to include leptospirosis in cattle health surveillance programmes to prevent leptospirosis by vaccination, preventing renal carriage.
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Affiliation(s)
- K Senthilkumar
- Zoonoses Research Laboratory, Centre for Animal Health Studies, TANUVAS, Chennai 60051.
| | - G Ravikumar
- Translational Research Platform for Veterinary Biologicals, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu, India.
| | - Aravindh Babu R Parthiban
- Translational Research Platform for Veterinary Biologicals, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu, India.
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Chand NRK, Sudhakar BK, Ravikumar G, Gayathri V, Devika P, Vennela T, Rao GS, Rao CS. Influence of multi valent states of vanadium ions in ZnO doped novel calcium fluoro phosphate bio glasses. J Mech Behav Biomed Mater 2022; 131:105230. [PMID: 35561600 DOI: 10.1016/j.jmbbm.2022.105230] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/05/2022] [Accepted: 04/09/2022] [Indexed: 11/16/2022]
Abstract
ZnO-CaF2-P2O5 glasses doped with different concentrations of V2O5 (ranging from 0 to 1.0 mol %) were prepared. The prepared bio glasses are soaked in SBF for duration of 2, 3, 7 and 10 days in separate plastic containers and then kept in incubator maintained at body temperature 36.5 °C. The influence of valence states of vanadium ions (V4+/V5+) with respect to the structural aspects by means of FTIR and Raman Spectra, elastic properties by means of relevant parameters, the thermal stability by means of DTA studies and other spectroscopic properties by using OA and ESR studies are studied. The raise in wavenumber and comparative areas of the two absorption bands corresponding to electronic transitions 2B2g → E2g, 2B2g → 2B1g respectively in optical absorption spectra of these CZPV glasses clearly indicate that vanadium ions have octahedral co-ordination with tetragonal compression due to modifier action of V2O5in the glass network. The optical absorption and ESR studies have revealed that vanadium ions exist in V4+ states. The characteristic temperatures of these prepared glasses obtained from DTA curves explain modifications taking place in the structure of glass network. The structural changes are explained with the aid of FTIR and Raman studies. The bio active nature of the titled glasses is evident from dissociation and pH studies by SEM &EDS of these glasses before and after immersion into SBF.
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Affiliation(s)
| | - B K Sudhakar
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India
| | - G Ravikumar
- Department of Physics, Sreenidhi Institute of Science and Technology, JNT University, Hyderabad, 501301, India
| | - V Gayathri
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India
| | - P Devika
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India
| | - T Vennela
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India
| | - G Srinivasa Rao
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India.
| | - Ch Srinivasa Rao
- Department of Physics, Andhra Loyola College, Vijayawada, AP, India.
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Senthilkumar K, Ravikumar G. Lateral flow assay for rapid serodiagnosis of bovine leptospirosis. Iran J Vet Res 2022; 23:7-11. [PMID: 35782352 PMCID: PMC9238931 DOI: 10.22099/ijvr.2021.41151.5974] [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] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 12/13/2021] [Indexed: 11/11/2022]
Abstract
Background Leptospirosis is considered to be an economically important disease in bovine. The disease burden is not appropriately monitored due to cumbersome serological tests that could be performed only in established laboratories. This warrants the development of a field level rapid diagnostic test. Aims The study aimed to develop a lateral flow assay (LFA)-based pen-side diagnostic test to detect antibodies to Leptospira. Methods LFA strip was prepared with the heat extracted antigen from L. interrogans serovar Pomona. To assess the performance of the developed LFA, a total of 300 bovine serum samples with their clinical histories were used and the initial screening for Leptospira antibodies was performed by the standard microscopic agglutination test (MAT). The sensitivity, specificity, and agreement (kappa value) were calculated between developed LFA and MAT. The stability of LFA was evaluated on days 30, 60, 90, and 120. Results Out of 300 samples tested, 225 were positive, and 75 were negative on MAT and 208 were positive, and 92 were negative on LFA. The developed LFA had a sensitivity of 90.7% and a specificity of 94.7%. The results of the assay were substantially in agreement with MAT, with a kappa value of 0.79. The LFA strips were stable for 120 days at 4°C. Conclusion A Lateral flow assay-based rapid pen-side test was developed and its utility to diagnose bovine leptospirosis was evaluated.
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Affiliation(s)
- K. Senthilkumar
- Correspondence: K. Senthilkumar, Zoonoses Research Laboratory, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600051, Tamil Nadu, India. E-mail:
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Kochhar P, Dwarkanath P, Ravikumar G, Thomas A, Crasta J, Thomas T, Kurpad AV, Mukhopadhyay A. Placental expression of miR-21-5p, miR-210-3p and miR-141-3p: relation to human fetoplacental growth. Eur J Clin Nutr 2021; 76:730-738. [PMID: 34611295 DOI: 10.1038/s41430-021-01017-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 09/06/2021] [Accepted: 09/21/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND/OBJECTIVES Dysregulation of microRNAs (miRNAs) and their target genes in placental tissue is associated with foetal growth restriction. We aimed to evaluate associations of placental miR-21-5p, miR-141-3p and miR-210-3p expression with maternal, placental and newborn parameters and with placental expression of their potential target genes PTEN, VEGF, FLT and ENG in a set of well-characterized small- (SGA) and appropriate- (AGA) for gestational age full-term singleton pregnancies. SUBJECTS/METHODS Placental samples (n = 80) from 26 SGA and 54 AGA were collected from full-term singleton pregnancies. Placental transcript abundances of miR-21-5p, miR-141-3p and miR-210-3p were assessed after normalization to a reference miRNA, mir-16-5p by real-time quantitative PCR. Placental transcript abundances of PTEN, VEGF, FLT and ENG were assessed after normalizing to a panel of reference genes. RESULTS Placental miR-21-5p transcript abundance was negatively associated with placental weight (n = 80, r = -0.222, P = 0.047) and this association was specific to the AGA births (n = 54, r = -0.292, P = 0.032). Placental transcript abundances of miR-210-3p and miR-141-3p were not associated with placental weight or birth weight in all 80 births. However, placental miR-210-3p transcript abundance was positively associated with birth weight specifically in the SGA births (n = 26, r = 0.449, P = 0.021). Placental transcript abundance of miR-21-5p was negatively associated with PTEN transcript abundance (Spearman's ρ = -0.245, P = 0.028) while that of miR-141-3p was positively associated with FLT (Spearman's ρ = 0.261, P = 0.019) and ENG (Spearman's ρ = 0.259, P = 0.020) transcript abundances in all 80 births. CONCLUSION We conclude that placental miR-21-5p and miR-210-3p may be involved in fetoplacental growth. However, this regulation is unlikely to be mediated through placental expression of PTEN, VEGF, FLT or ENG.
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Affiliation(s)
- P Kochhar
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, India
| | - P Dwarkanath
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, India
| | - G Ravikumar
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - A Thomas
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - J Crasta
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - T Thomas
- Department of Biostatistics, St. John's Medical College Hospital, Bangalore, India
| | - A V Kurpad
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, India
| | - A Mukhopadhyay
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, India.
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Kochhar P, Dwarkanath P, Ravikumar G, Thomas A, Crasta J, Thomas T, Kurpad AV, Mukhopadhyay A. Placental expression of RNU44, RNU48 and miR-16-5p: stability and relations with fetoplacental growth. Eur J Clin Nutr 2021; 76:722-729. [PMID: 34508256 DOI: 10.1038/s41430-021-01003-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 08/04/2021] [Accepted: 08/24/2021] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES The current study aimed to identify suitable reference miRNA for placental miRNA expression analysis in a set of well-characterized and fetal-sex balanced small- (SGA) and appropriate- (AGA) for gestational age full-term singleton pregnancies. SUBJECTS/METHODS In this retrospective study, placental samples (n = 106) from 35 SGA (19 male and 16 female) and 71 AGA (30 male and 41 female) full-term singleton pregnancies were utilized. Placental transcript abundance of three widely used reference miRNAs [miR-16-5p and Small nucleolar RNAs (snoRNAs) RNU44 and RNU48] were assessed by real-time quantitative PCR. Raw cycle threshold (Ct) analysis and RefFinder tool analysis were conducted for evaluating stability of expression of these miRNAs. RESULTS Raw Ct values of miR-16-5p were similar between SGA and AGA births (P = 0.140) and between male and female births within SGA (P = 0.159) and AGA (P = 0.060) births while that of RNU44 and RNU48 were higher in SGA births (P = 0.008 and 0.006 respectively) and in male births within the SGA group (P = 0.005) for RNU44 and in female births within the AGA group (P = 0.048) for RNU48. Across all 106 samples tested using the RefFinder tool, miR-16-5p and RNU44 were equally stable reference miRNAs. CONCLUSION We recommend miR-16-5p and RNU44 as suitable reference miRNAs for placental samples from settings similar to our study.
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Affiliation(s)
- P Kochhar
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, Karnataka, India
| | - P Dwarkanath
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, Karnataka, India
| | - G Ravikumar
- Department of Pathology, St John's Medical College Hospital, Bangalore, Karnataka, India
| | - A Thomas
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, Karnataka, India
| | - J Crasta
- Department of Pathology, St John's Medical College Hospital, Bangalore, Karnataka, India
| | - T Thomas
- Department of Biostatistics, St. John's Medical College Hospital, Bangalore, Karnataka, India
| | - A V Kurpad
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, Karnataka, India
| | - A Mukhopadhyay
- Division of Nutrition, St. John's Research Institute, A recognized research centre of University of Mysore, Bangalore, Karnataka, India.
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Kochhar P, Manikandan C, Ravikumar G, Dwarkanath P, Sheela CN, George S, Thomas A, Crasta J, Thomas T, Kurpad AV, Mukhopadhyay A. Placental expression of leptin: fetal sex-independent relation with human placental growth. Eur J Clin Nutr 2020; 74:1603-1612. [PMID: 32382074 DOI: 10.1038/s41430-020-0649-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Leptin (LEP) is a vital placental hormone that is known to affect different aspects of placental function and fetal development. The present study aimed to determine the association of placental LEP transcript abundance with maternal, placental, and newborn parameters. SUBJECTS/METHODS In this retrospective case-control study, placental samples (n = 105) were collected from small (SGA) and appropriate (AGA) for gestational age full-term singleton pregnancies (n = 44 SGA and n = 61 AGA). Placental transcript abundance of LEP was assessed by real-time quantitative PCR after normalization to a reference gene panel. LEP methylation was measured using a quantitative MethyLight assay in a subset of samples (n = 54). RESULTS Placental LEP transcript abundance was negatively and significantly associated with placental weight (β = -3.883, P = 0.015). This association continued to be significant in the SGA group (β = -10.332, P = 0.001), both in female (β = -15.423, P = 0.021) and male births (β = -10.029, P = 0.007). LEP transcript abundance was not associated with LEP methylation levels (Spearman's ρ = 0.148, P = 0.287). CONCLUSION We conclude that placental upregulation of LEP is an integral and fetal sex-independent component of placental growth restriction, which can be potentially targeted through maternal dietary modifications to improve fetoplacental growth.
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Affiliation(s)
- P Kochhar
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - C Manikandan
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.,School of Biosciences and Technology; Centre for Biomaterials, Cellular and Molecular Theranostics, Vellore Institute of Technology, Vellore, India
| | - G Ravikumar
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - P Dwarkanath
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - C N Sheela
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - S George
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - A Thomas
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - J Crasta
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - T Thomas
- Department of Biostatistics, St. John's Medical College Hospital, Bangalore, India
| | - A V Kurpad
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - A Mukhopadhyay
- Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.
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Mani C, Kochhar P, Ravikumar G, Dwarkanath P, Sheela CN, George S, Thomas A, Crasta J, Thomas T, Kurpad AV, Mukhopadhyay A. Placental expression of ENG, VEGF, and FLT: Gender-specific associations with maternal vitamin B 12 status. Eur J Clin Nutr 2019; 74:176-182. [PMID: 31209272 DOI: 10.1038/s41430-019-0449-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 03/03/2019] [Accepted: 06/03/2019] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Adequate vitamin B12 is a requisite during pregnancy and its deficiency is linked with increased risk for adverse outcomes, likely mediated by impaired placental angiogenesis. Thus, we aimed to test associations of maternal vitamin B12 status with the placental expression of angiogenesis-associated genes ENG, VEGF, and FLT. SUBJECTS/METHODS In this retrospective case-control study, placental and maternal trimester 1 blood samples (n = 104) were collected from small for gestational age (SGA) and appropriate for gestational age (AGA) full-term singleton pregnancies. Maternal trimester 1 vitamin B12 status was measured. Placentae and neonates were weighed at birth. Realtime quantitative PCR was performed to assess placental transcript abundance of ENG, VEGF, and FLT normalized to a panel of reference genes. Associations of placental transcript abundance of the genes with maternal trimester 1 vitamin B12 status were evaluated. RESULTS Placental ENG transcript abundance associated negatively with maternal trimester 1 vitamin B12 status (β = -0.461, P = 0.017, n = 104). This association was specific to the female births (β = -0.590, P = 0.014, n = 60). Placental VEGF transcript levels were negatively associated with maternal trimester 1 vitamin B12 status only in the female births (β = -1.995, P = 0.029). Placental FLT transcript levels were not associated with maternal trimester 1 vitamin B12 status. CONCLUSION Maternal trimester 1 vitamin B12 status was associated negatively with placental ENG and VEGF expression predominantly in the female births. Therefore, we hypothesize that the placenta adapts to low maternal vitamin B12 status by up-regulating angiogenic pathways in a gender-specific manner.
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Affiliation(s)
- C Mani
- Division of Nutrition, St. John's Research Institute, St. John's Academy of Health Sciences, Bangalore, India
| | - P Kochhar
- Division of Nutrition, St. John's Research Institute, St. John's Academy of Health Sciences, Bangalore, India
| | - G Ravikumar
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - P Dwarkanath
- Division of Nutrition, St. John's Research Institute, St. John's Academy of Health Sciences, Bangalore, India
| | - C N Sheela
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - S George
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - A Thomas
- Department of Obstetrics and Gynaecology, St John's Medical College Hospital, Bangalore, India
| | - J Crasta
- Department of Pathology, St John's Medical College Hospital, Bangalore, India
| | - T Thomas
- Department of Biostatistics, St. John's Medical College, St. John's Academy of Health Sciences, Bangalore, India
| | - A V Kurpad
- Division of Nutrition, St. John's Research Institute, St. John's Academy of Health Sciences, Bangalore, India
| | - A Mukhopadhyay
- Division of Nutrition, St. John's Research Institute, St. John's Academy of Health Sciences, Bangalore, India.
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Prajapat CL, Singh S, Bhattacharya D, Ravikumar G, Basu S, Mattauch S, Zheng JG, Aoki T, Paul A. Proximity effects across oxide-interfaces of superconductor-insulator-ferromagnet hybrid heterostructure. Sci Rep 2018; 8:3732. [PMID: 29487317 PMCID: PMC5829237 DOI: 10.1038/s41598-018-22036-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/15/2018] [Indexed: 11/24/2022] Open
Abstract
A case study of electron tunneling or charge-transfer-driven orbital ordering in superconductor (SC)-ferromagnet (FM) interfaces has been conducted in heteroepitaxial YBa2Cu3O7(YBCO)/La0.67Sr0.33MnO3(LSMO) multilayers interleaved with and without an insulating SrTiO3(STO) layer between YBCO and LSMO. X-ray magnetic circular dichroism experiments revealed anti-parallel alignment of Mn magnetic moments and induced Cu magnetic moments in a YBCO/LSMO multilayer. As compared to an isolated LSMO layer, the YBCO/LSMO multilayer displayed a (50%) weaker Mn magnetic signal, which is related to the usual proximity effect. It was a surprise that a similar proximity effect was also observed in a YBCO/STO/LSMO multilayer, however, the Mn signal was reduced by 20%. This reduced magnetic moment of Mn was further verified by depth sensitive polarized neutron reflectivity. Electron energy loss spectroscopy experiment showed the evidence of Ti magnetic polarization at the interfaces of the YBCO/STO/LSMO multilayer. This crossover magnetization is due to a transfer of interface electrons that migrate from Ti(4+)−δ to Mn at the STO/LSMO interface and to Cu2+ at the STO/YBCO interface, with hybridization via O 2p orbitals. So charge-transfer driven orbital ordering is the mechanism responsible for the observed proximity effect and Mn-Cu anti-parallel coupling in YBCO/STO/LSMO. This work provides an effective pathway in understanding the aspect of long range proximity effect and consequent orbital degeneracy parameter in magnetic coupling.
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Affiliation(s)
- C L Prajapat
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Surendra Singh
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400085, India
| | - D Bhattacharya
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - G Ravikumar
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - S Basu
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400085, India
| | - S Mattauch
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, D-85747, Garching b. München, Germany
| | - Jian-Guo Zheng
- Irvine Materials Research Institute, University of California, Irvine, CA, 92697-2800, USA
| | - T Aoki
- Irvine Materials Research Institute, University of California, Irvine, CA, 92697-2800, USA
| | - Amitesh Paul
- Technische Universität München, Physik Department E21, Lehrstuhl für Neutronenstreuung, James-Franck-Straße 1, D-85748, Garching, Germany.
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Gupta S, Ajith Kumar KG, Sharma AK, Nagar G, Kumar S, Saravanan BC, Ravikumar G, Ghosh S. Esterase mediated resistance in deltamethrin resistant reference tick colony of Rhipicephalus (Boophilus) microplus. Exp Appl Acarol 2016; 69:239-248. [PMID: 26979585 DOI: 10.1007/s10493-016-0032-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 02/28/2016] [Indexed: 06/05/2023]
Abstract
Monitoring of acaricide resistance is considered as one of the important facets of integrated tick management. In an attempt of development of resistance monitoring indicators, in the present study two reference tick lines of Rhipicephalus (Boophilus) microplus maintained in the Entomology laboratory, Indian Veterinary Research Institute (IVRI), Izatnagar, India, were studied to determine the possible contributing factors involved in development of resistance to deltamethrin. Electrophoretic profiling of esterase enzymes detected high activities of EST-1 in reference resistant tick colony designated as IVRI-IV whereas it was not detectable in reference susceptible IVRI-I line of R. (B.) microplus. Esterases were further characterized as carboxylesterase or acetylcholinesterase based on inhibitor study using PMSF, eserine sulphate, malathion, TPP and copper sulphate. It was concluded that an acetylcholinesterase, EST-1, possibly plays an important role for development of deltamethrin resistance in IVRI-IV colony of R. (B.) microplus.
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Affiliation(s)
- Snehil Gupta
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - K G Ajith Kumar
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - Anil Kumar Sharma
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - Gaurav Nagar
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - Sachin Kumar
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - B C Saravanan
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - Gandham Ravikumar
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India
| | - Srikant Ghosh
- Entomology Laboratory, Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P., 243122, India.
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Prajapat CL, Singh S, Paul A, Bhattacharya D, Singh MR, Mattauch S, Ravikumar G, Basu S. Superconductivity-induced magnetization depletion in a ferromagnet through an insulator in a ferromagnet-insulator-superconductor hybrid oxide heterostructure. Nanoscale 2016; 8:10188-10197. [PMID: 27124772 DOI: 10.1039/c6nr01869f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Coupling between superconducting and ferromagnetic states in hybrid oxide heterostructures is presently a topic of intense research. Such a coupling is due to the leakage of the Cooper pairs into the ferromagnet. However, tunneling of the Cooper pairs though an insulator was never considered plausible. Using depth sensitive polarized neutron reflectivity we demonstrate the coupling between superconductor and magnetic layers in epitaxial La2/3Ca1/3MnO3 (LCMO)/SrTiO3/YBa2Cu3O7-δ (YBCO) hybrid heterostructures, with SrTiO3 as an intervening oxide insulator layer between the ferromagnet and the superconductor. Measurements above and below the superconducting transition temperature (TSC) of YBCO demonstrate a large modulation of magnetization in the ferromagnetic layer below the TSC of YBCO in these heterostructures. This work highlights a unique tunneling phenomenon between the epitaxial layers of an oxide superconductor (YBCO) and a magnetic layer (LCMO) through an insulating layer. Our work would inspire further investigations on the fundamental aspect of a long range order of the triplet spin-pairing in hybrid structures.
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Affiliation(s)
- C L Prajapat
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India
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Mukhopadhyay A, Ravikumar G, Dwarkanath P, Meraaj H, Thomas A, Crasta J, Thomas T, Kurpad A, Sridhar T. Placental expression of the insulin receptor binding protein GRB10: Relation to human fetoplacental growth and fetal gender. Placenta 2015; 36:1225-30. [DOI: 10.1016/j.placenta.2015.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/13/2015] [Accepted: 09/08/2015] [Indexed: 11/27/2022]
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13
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Ravikumar G, Ashok Murthy V. A Study of Brainstem Auditory Evoked Responses in Normal Hearing Patients with Tinnitus. Indian J Otolaryngol Head Neck Surg 2015; 68:429-433. [PMID: 27833867 DOI: 10.1007/s12070-015-0917-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 09/21/2015] [Indexed: 11/24/2022] Open
Abstract
Tinnitus is thought to be an auditory phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway either in the peripheral or central auditory system. The neural abnormalities underlying tinnitus are largely unknown. This study analysis the auditory brainstem responses in normal hearing patients with tinnitus. This study consisted of 100 patients divided into two groups. Group I (Control): 50 Normal hearing patients without tinnitus. Group II (Study): 50 Normal hearing patients complaining of tinnitus. Both groups were submitted to full audiological history taking, otological examination, basic audiologic evaluation and Auditory brainstem responses (ABR) followed by calculation of the absolute latencies of wave I, III and V and interpeak latencies between waves I-III, III-V and I-V. In the study group 20 patients showed abnormal results in at least 1 of the 6 parameters evaluated. The results of absolute latencies of wave I, III and V showed significant prolongation, but the interpeak latencies of waves I-III, III-V and I-V were not significantly prolonged when compared with control group. Our study data showed that there are changes in the central pathways in the study group. The significance of these changes must be investigated with further audiological and neurological tests. We also understand that ABR has to be included in the work up of tinnitus patients whose hearing is within normal parameters.
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Affiliation(s)
- G Ravikumar
- Department of ENT, Rajiv Gandhi Institute of Medical Sciences, Kadapa, 516 001 India
| | - V Ashok Murthy
- Department of ENT, Rajiv Gandhi Institute of Medical Sciences, Kadapa, 516 001 India
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14
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Ravikumar G, Manimaran P, Voleti SR, Subrahmanyam D, Sundaram RM, Bansal KC, Viraktamath BC, Balachandran SM. Stress-inducible expression of AtDREB1A transcription factor greatly improves drought stress tolerance in transgenic indica rice. Transgenic Res 2014; 23:421-39. [PMID: 24398893 PMCID: PMC4010723 DOI: 10.1007/s11248-013-9776-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 12/06/2013] [Indexed: 12/11/2022]
Abstract
The cultivation of rice (Oryza sativa L.), a major food crop, requires ample water (30 % of the fresh water available worldwide), and its productivity is greatly affected by drought, the most significant environmental factor. Much research has focussed on identifying quantitative trait loci, stress-regulated genes and transcription factors that will contribute towards the development of climate-resilient/tolerant crop plants in general and rice in particular. The transcription factor DREB1A, identified from the model plant Arabidopsis thaliana, has been reported to enhance stress tolerance against drought stress. We developed transgenic rice plants with AtDREB1A in the background of indica rice cultivar Samba Mahsuri through Agrobacterium-mediated transformation. The AtDREB1A gene was stably inherited and expressed in T1 and T2 plants and in subsequent generations, as indicated by the results of PCR, Southern blot and RT-PCR analyses. Expression of AtDREB1A was induced by drought stress in transgenic rice lines, which were highly tolerant to severe water deficit stress in both the vegetative and reproductive stages without affecting their morphological or agronomic traits. The physiological studies revealed that the expression of AtDREB1A was associated with an increased accumulation of the osmotic substance proline, maintenance of chlorophyll, increased relative water content and decreased ion leakage under drought stress. Most of the homozygous lines were highly tolerant to drought stress and showed significantly a higher grain yield and spikelet fertility relative to the nontransgenic control plants under both stressed and unstressed conditions. The improvement in drought stress tolerance in combination with agronomic traits is very essential in high premium indica rice cultivars, such as Samba Mahsuri, so that farmers can benefit in times of seasonal droughts and water scarcity.
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Affiliation(s)
- G. Ravikumar
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
| | - P. Manimaran
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
| | - S. R. Voleti
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
| | - D. Subrahmanyam
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
| | - R. M. Sundaram
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
| | - K. C. Bansal
- National Bureau of Plant Genetic Resources, Pusa Campus, New Delhi, 110 012 India
| | - B. C. Viraktamath
- Directorate of Rice Research, Rajendranagar, Hyderabad, 500 030 India
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Sharma P, Ravikumar G, Kalaiselvi M, Gomathi D, Uma C. In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia. J Pharm Anal 2013; 3:298-302. [PMID: 29403831 PMCID: PMC5760975 DOI: 10.1016/j.jpha.2013.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [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: 05/23/2012] [Accepted: 01/24/2013] [Indexed: 11/28/2022] Open
Abstract
Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine.
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Affiliation(s)
- Pardeep Sharma
- Department of Biochemistry, Karpagam University, Coimbatore 641021, India
| | - G Ravikumar
- Department of Biochemistry, Karpagam University, Coimbatore 641021, India
| | - M Kalaiselvi
- Department of Biochemistry, Karpagam University, Coimbatore 641021, India
| | - D Gomathi
- Department of Biochemistry, Karpagam University, Coimbatore 641021, India
| | - C Uma
- Department of Biochemistry, Karpagam University, Coimbatore 641021, India
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Gomathi D, Kalaiselvi M, Ravikumar G, Devaki K, Uma C. Evaluation of antioxidants in the kidney of streptozotocin induced diabetic rats. Indian J Clin Biochem 2013; 29:221-6. [PMID: 24757306 DOI: 10.1007/s12291-013-0344-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 05/15/2013] [Indexed: 12/31/2022]
Abstract
Diabetes mellitus is one of the most common endocrine metabolic disorders. Dual endocrine deficits of impaired insulin action (insulin resistance) and inadequate insulin secretion create an environment of chronic hyperglycemia and general metabolic disarray. Oxidative stress plays an important role in diabetic pathogenesis. Oxidative stress induced by streptozotocin (STZ) has been shown to damage pancreatic beta cell and produce hyperglycemia in rats. The present study was made to evaluate the antioxidant activity of ethanolic extract of the Evolvulus alsinoides in STZ induced rats. The antioxidant activities were done by using standard protocols. For histopathological analysis, the pancreatic tissues of all experimental groups were fixed with 10 % formalin for 24 h then the samples were stained with hematoxylin-eosin for the microscopic observation. Our results showed the significant decrease in lipid peroxidation and increases in the antioxidant (both enzymatic and nonenzymatic) levels after treatment with standard as well as the E. alsinoides. There is no significant difference between control and plant alone group rats. The histopathology reports also revealed non-toxic effect and protective effect of E. alsinoides in the kidney of STZ induced diabetic rats. Our result indicated that the E. alsinoides extract effectively increased the antioxidant level thereby it prevents oxidative stress during diabetes mellitus and also it showed the protective effect on kidney of STZ induced rats. Hence it can be used to maintain the antioxidant level during diabetes mellitus.
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Affiliation(s)
- D Gomathi
- Department of Biochemistry, Karpagam University, Coimbatore, 641 021 India
| | - M Kalaiselvi
- Department of Biochemistry, Karpagam University, Coimbatore, 641 021 India
| | - G Ravikumar
- Department of Biochemistry, Karpagam University, Coimbatore, 641 021 India
| | - K Devaki
- Department of Biochemistry, Karpagam University, Coimbatore, 641 021 India
| | - C Uma
- Biochemistry College of Medicine and Health Science, Hawassa University, Hawassa, Ethiopia
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Sreekumar C, Selvaraj J, Gomathinayagam S, Thangapandiyan M, Ravikumar G, Roy P, Balachandran C. Blastocystis sp. from food animals in India. J Parasit Dis 2013; 38:440-3. [PMID: 25320500 DOI: 10.1007/s12639-013-0236-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 01/01/2013] [Indexed: 11/25/2022] Open
Abstract
Blastocystis, a zoonotic protozoan found in the intestinal tracts of a wide range of animals, has not been reported from non-human hosts from India so far. Organisms indistinguishable from Blastocystis sp. were identified in the Giemsa stained intestinal scrapings collected from carcasses of piglet and poultry that were brought for necropsy to the Central University Laboratory, Chennai. The 'central vacuole forms' of the parasite, with number of nuclei ranging from 1 to 12 were identified. The intensity of infection was low, with less than one organism per oil immersion field, indicating that their presence was unconnected to the cause of death. Caecal scraping was found to be more ideal than duodenal scraping for the diagnosis of Blastocystis, and can be a potential specimen for definitive diagnosis. Identical organisms were also detected in the dung samples of a buffalo calf which showed clinical signs of diarrhoea The presence of Blastocystis in food animals acquires public health significance, as many subtypes of the parasite from poultry and pigs are transmissible to humans.
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Affiliation(s)
- C Sreekumar
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600051 Tamil Nadu India ; Post Graduate Research Institute in Animal Sciences, Kattupakkam, Kancheepuram, Tamil Nadu 603203 India
| | - J Selvaraj
- Department of Veterinary Pathology, Veterinary College and Research Institute, Orathanadu, Tanjore, 614625 Tamil Nadu India
| | - S Gomathinayagam
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600051 Tamil Nadu India
| | - M Thangapandiyan
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600051 Tamil Nadu India
| | - G Ravikumar
- Leptospirosis Research Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk colony, Chennai, 600051 India
| | - Parimal Roy
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600051 Tamil Nadu India
| | - C Balachandran
- Post Graduate Research Institute in Animal Sciences, Kattupakkam, Kancheepuram, Tamil Nadu 603203 India
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Kalaiselvi M, Gomathi D, Ravikumar G, Devaki K, Uma C. Ameliorative effect of Ananus comosus peel on 7, 12 dimethylbenz(α)anthracene induced mammary carcinogenesis with reference to oxidative stress. Journal of Acute Disease 2013. [DOI: 10.1016/s2221-6189(13)60089-x] [Citation(s) in RCA: 9] [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: 11/26/2022] Open
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Sathish R, Suhas S, Gayathri G, Ravikumar G, Chandrashekar L, Omprakash TL. Embedded toothbrush foreign body in cheek — report of an unusual case. Eur Arch Paediatr Dent 2012; 12:272-4. [DOI: 10.1007/bf03262821] [Citation(s) in RCA: 9] [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: 10/27/2022]
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Morphew RM, Eccleston N, Wilkinson TJ, McGarry J, Perally S, Prescott M, Ward D, Williams D, Paterson S, Raman M, Ravikumar G, Khalid Saifullah M, Abbas Abidi SM, McVeigh P, Maule AG, Brophy PM, LaCourse EJ. Proteomics and in Silico Approaches To Extend Understanding of the Glutathione Transferase Superfamily of the Tropical Liver Fluke Fasciola gigantica. J Proteome Res 2012; 11:5876-89. [DOI: 10.1021/pr300654w] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Russell M. Morphew
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY23 2DA, U.K
| | - Neil Eccleston
- Faculty of Veterinary Science, University of Liverpool, L69 7ZJ, U.K
| | - Toby J. Wilkinson
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY23 2DA, U.K
| | - John McGarry
- Faculty of Veterinary Science, University of Liverpool, L69 7ZJ, U.K
| | - Samirah Perally
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY23 2DA, U.K
| | - Mark Prescott
- School of Biological Sciences, University of Liverpool, L69 7ZB, U.K
| | - Deborah Ward
- School of Biological Sciences, University of Liverpool, L69 7ZB, U.K
| | - Diana Williams
- Faculty of Veterinary Science, University of Liverpool, L69 7ZJ, U.K
| | - Steve Paterson
- School of Biological Sciences, University of Liverpool, L69 7ZB, U.K
| | - M. Raman
- Tamil Nadu Veterinary and Animal Sciences University, Chennai 600-051, India
| | - G. Ravikumar
- Tamil Nadu Veterinary and Animal Sciences University, Chennai 600-051, India
| | | | | | - Paul McVeigh
- School of Biological
Sciences, Queen’s University Belfast, Belfast, Northern Ireland, U.K
| | - Aaron G. Maule
- School of Biological
Sciences, Queen’s University Belfast, Belfast, Northern Ireland, U.K
| | - Peter M. Brophy
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY23 2DA, U.K
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Gomathi D, Muthulakshmi C, Guru Kumar D, Ravikumar G, Kalaiselvi M, Uma C. Production of bio-ethanol from pretreated agricultural byproduct using enzymatic hydrolysis and simultaneous saccharification. Microbiology (Reading) 2012. [DOI: 10.1134/s0026261712010079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Gomathi D, Muthulakshmi C, Kumar DG, Ravikumar G, Kalaiselvi M, Uma C. Production of bio-ethanol from pretreated agricultural byproduct using enzymatic hydrolysis and simultaneous saccharification. Mikrobiologiia 2012; 81:220-226. [PMID: 22693831] [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: 06/01/2023]
Abstract
Global warming alerts and threats are on the rise due to the utilization of fossil fuels. Alternative fuel sources like bio-ethanol and biodiesel are being produced to combat against these threats. Bio-ethanol can be produced from a range of substrate. The present study is aimed at the Production of bioethanol from pretreated agricultural substrate using enzymatic hydrolysis and simultaneous saccharification with the addition of purified fungal enzyme. Most cellulosic biomass is not fermentable without appropriate pretreatment methods and so dilute sulfuric acid pretreatment was applied to make the cellulose contained in the waste susceptible to endoglucanase enzyme. A range of acid pretreatment of wheat bran was made in which the sample that was pretreated with 1% dilute sulfuric acid gave maximum yield of ethanol in both methods such as 5.83 g L(-1) and 5.27 g L(-1), respectively. Ethanol produced from renewable and cheap agricultural products (wheat bran) provides reduction in green house gas emission, carbon monoxide, sulfur, and helps to eliminate smog from the environment.
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Affiliation(s)
- D Gomathi
- Department of Biochemistry, Karpagam University, Coimbatore, 641021, India
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Ravikumar G, Kalegowda IY, Ananthamurthy A. Clinicopathologic spectrum of gastro intestinal stromal tumours - experience at a tertiary care center. Indian J Cancer 2012; 48:466-70. [PMID: 22293262 DOI: 10.4103/0019-509x.92281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
CONTEXT Accurate diagnosis of Gastrointestinal stromal tumors (GISTs) and categorization of risk groups is crucial in the wake of targeted drug therapy. AIM This study was undertaken to obtain insight into the clinicopathologic features of GISTs. MATERIALS AND METHODS Retrospective study of 20 cases of c-KIT (CD 117) positive GISTs .Various histologic parameters were studied. Immunohistochemical panel included CD-34, Smooth muscle actin, S-100, Desmin, and Vimentin. Risk categorization was done as per standard protocol. Clinical details and follow up were retrieved from cases files. RESULTS Of the total 20 cases, 15 were males. The mean age of presentation was 52 years. 50 % of the cases presented with gastro intestinal bleeding. The cases were categorized as high risk (60%), intermediate risk (20%), low risk (15%) and very low risk (5%). Stomach and small intestine were commonly involved and in 6 of the cases there were metastatic nodules in the mesentery/omentum/ peritoneum. Spindle cell morphology was the commonest histological pattern (55%). Nuclear pleomorphism, perivascular whorling, mucosal and fat invasion were seen only in the high risk group. CD-34, SMA and S-100 were positive in 90%, 30%, and 10% of the cases, respectively, with consistent Desmin negativity. CONCLUSIONS Cases of GISTs in our clinical setting presented a decade earlier and mostly belonged to the high risk group. Certain histological features such as necrosis, and perivascular whorling were more commonly associated with the high risk groups.
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Affiliation(s)
- G Ravikumar
- Department of Pathology, St. John's Medical College and Hospital, Bangalore, India
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Uma C, Gomathi D, Ravikumar G, Kalaiselvi M, Palaniswamy M. Production and properties of invertase from a Cladosporium cladosporioides in SmF using pomegranate peel waste as substrate. Asian Pac J Trop Biomed 2012. [DOI: 10.1016/s2221-1691(12)60282-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Ravikumar G, Raje Urs S, Vijaya Prakash NB, Rao CGP, Vardhana KV. Development of a multiplex polymerase chain reaction for the simultaneous detection of microsporidians, nucleopolyhedrovirus, and densovirus infecting silkworms. J Invertebr Pathol 2011; 107:193-7. [PMID: 21570404 DOI: 10.1016/j.jip.2011.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 04/15/2011] [Accepted: 04/19/2011] [Indexed: 10/18/2022]
Abstract
We have developed a novel PCR-based assay for individual and simultaneous detection of three major pathogens (microsporidians, nucleopolyhedrovirus (NPV) and densovirus (DNV)) infecting the silkworm, Bombyx mori. Multiplex PCR, using three primer pairs, two of which were designed from the conserved regions of 16S small subunit ribosomal RNA gene of microsporidians, and polyhedrin gene of NPVs respectively, and a third primer pair designed from the internal sequences of B. mori DNVs (BmDNV), showed discrete and pathogen specific PCR products. The assay showed high specificity and sensitivity for the pathogenic DNA. Under optimized PCR conditions, the assay yielded a 794bp DNA fragment from Nosema bombycis, 471bp fragment from B. mori NPV (BmNPV) and 391bp fragment from BmDNV. Further, this detection method was successfully applied to other silkworm species such as Antheraea mylitta and Samia cynthia ricini, in detecting same or similar pathogens infecting them. This method is a valuable supplement to the conventional microscopic diagnostic methods and can be used for the early detection of pathogens infecting silkworms. Furthermore it can assist research and extension centers for the safe supply of disease-free silkworms to farmers.
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Affiliation(s)
- G Ravikumar
- Seri-biotech Research Laboratory, Central Silk Board, Carmelaram Post, Kodathi, Bangalore, India.
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Ravikumar G, Vardhana KV, Basavaraja HK. Characterization of lipophorin receptor (LpR) mediating the binding of high density lipophorin (HDLp) in the silkworm, Bombyx mori. J Insect Sci 2011; 11:150. [PMID: 22236107 PMCID: PMC3391906 DOI: 10.1673/031.011.15001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In an earlier report, we described the gene encoding a lipophorin receptor (LpR) of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), and recombinant expression of the protein. The present study was performed to characterize the corresponding native BmLpR and its binding characteristics. Polyclonal anti-LpR antibody prepared against the cloned receptor fragment from the cytoplasmic domain specifically detected the receptor. Through immunoblotting, ovary and brain membrane protein samples of BmLpR have shown an apparent molecular mass of 105 kDa and 120 kDa under nonreducing and reducing conditions, respectively. Ligand binding of LpR supported the immunoblot results. It bound to high density lipophorin (HDLp) and has shown requirement of Ca(2+) in binding. Further, a dose-dependent inhibition by EDTA was observed in receptor ligand binding. The characteristics of the BmLpR protein confirm the properties of a ligand-receptor interaction similar to that of vertebrate low density lipoprotein receptor (LDLR).
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Affiliation(s)
- G Ravikumar
- Seri-biotech Research Laboratory, Central Silk Board, Carmelaram Post, Kodathi, Bangalore 560035, India.
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Manoharan S, Parthiban M, Prabhakar TG, Ravikumar G, Koteeswaran A, Chandran NDJ, Rajavelu G. Rapid serological profiling by an immunocomb-based dot-enzyme-linked immunosorbent test for three major poultry diseases. Vet Res Commun 2004; 28:339-46. [PMID: 15222738 DOI: 10.1023/b:verc.0000026674.39593.7e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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: 11/12/2022]
Abstract
An immunocomb-based dot-ELISA, employing specially designed apparatus, was used to measure the antibody status for the three major poultry diseases--Newcastle disease, infectious bursal disease and infectious bronchitis--in single test sera. Positive samples could be classified into strong, moderate and weak positives by comparison with the colour reaction given by known strong and weak positive serum controls. The simultaneous dot-immunobinding assay gave reproducible results and allowed considerable savings on the cost of reagents compared to liquid ELISA. The antigen-coated immunocomb can be stored under refrigeration and the test can be performed rapidly under field conditions by trained personnel.
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Affiliation(s)
- S Manoharan
- Vaccine Research Centre-Viral Vaccines, Centre for Animal Health Studies, Tanuvas Madhavaram Milk Colony, Chennai 600 051, India.
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Affiliation(s)
- P Roy
- Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Madras, India
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Ghosh K, Ramakrishnan S, Grover AK, Menon GI, Chandra G, Ravikumar G, Mishra PK, Sahni VC, Tomy CV, Balakrishnan G, Bhattacharya S. Reentrant peak effect and the melting of a flux line lattice in 2H-NbSe2. Phys Rev Lett 1996; 76:4600-4603. [PMID: 10061332 DOI: 10.1103/physrevlett.76.4600] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Ravikumar G, Senthilkumaran B, Tewary PD, Goel AK. Circadian aspect of photoperiodic time measurement in a female house sparrow, Passer domesticus. J Biol Rhythms 1995; 10:319-23. [PMID: 8639940 DOI: 10.1177/074873049501000405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/01/2023]
Abstract
Endogenous circadian rhythms are involved in various photoperiodic responses of birds. Investigations involving the mechanisms of photoperiodic time measurement in birds have been confined mainly to temperate zone species using males exclusively. Due to the paucity of experimental evidence on subtropical birds that have very wide distribution, the present study was performed using subtropical female house sparrows. Photoperiodic sparrows were subjected to various T cycles for 60 days in which a fixed 3-h photophase was combined with scotophase in cycles of 20-30 h duration. Simultaneously, two groups of birds were also exposed to short days (light:dark = 8L:16D) or long days (15L:9D) as controls. Significant ovarian growth was found only in cycles of 3L:17D, 3L:23D, 3L:25D, and 3L:27D as well as in 15L:9D, whereas no positive response was detected in 3L:19D, 3L:21D, and 8L:16D. Plasma levels of estradiol showed a close relation to ovarian growth. The results indicate that photoperiodic time measurement in house sparrows involves an endogenous circadian rhythm.
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Affiliation(s)
- G Ravikumar
- Tasar Research and Training Institute, Central Silk Board, Nagri, Ranchi, India
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Ghosh K, Ramakrishnan S, Grover AK, Chandra G, Chandrasekhar Rao TV, Mishra PK, Ravikumar G, Sahni VC. Lower critical field of YNi2B2C and the influence of granularity. Phys Rev B Condens Matter 1995; 52:68-70. [PMID: 9979571 DOI: 10.1103/physrevb.52.68] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
Groups of photosensitive female house sparrows have been kept under night-interruption and intermittent light cycles for a period of 6 weeks. The night-interruption cycle consisted of a basic photophase of 6 h and 1 h photointerruption of the dark phase in the 24 h cycle at different points. Ovarian growth was stimulated under cycles in which photointerruption of the dark phase was made 10 h after the onset of basic photophase. The intermittent light cycles consisted of 2 L:2 D, 3 L:3 D, 4 L:4 D, 8 L:8 D and 12 L:12 D besides two control groups held on 7 L:17 D and 17 L:7 D. Ovarian response was observed only in 2 L:2 D, 3 L:3 D, 4 L:4 D, 12 L:12 D and 17 L:7 D cycles. The results of both the experiments are consistent with an avian external coincidence model and indicate that circadian rhythmicity is involved during the initiation of the female avian reproductive system.
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Affiliation(s)
- G Ravikumar
- Center of Advanced Study in Zoology, Banaras Hindu University, Varanasi, India
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Ravikumar G, Tewary PD. Photorefractoriness and its termination in the subtropical house sparrow, Passer domesticus: involvement of circadian rhythm. Chronobiol Int 1990; 7:187-91. [PMID: 2268880 DOI: 10.3109/07420529009056974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 12/31/2022]
Abstract
Groups of photorefractory female subtropical house sparrows, Passer domesticus, when treated with 6 weeks of a short photocycle (8L:16D) showed significant ovarian growth on their return to a long photocycle (15L:9D). A 6-hr photophase coupled with scotophase of varying durations does not terminate the refractory period under photoperiod cycles of 12 (6L:6D), 36 (6L:30D) and 60 (6L:54D) hr but the refractory period is terminated by light-dark cycles of 24 (6L:18D), 48 (6L:42D) and 72 (6L:66D) hr. These results are consistent with the Bünning hypothesis of coincidence between endogenous photosensitive rhythmicity and environmental photoperiod timing that an endogenous circadian rhythm is involved in the maintenance and termination of photorefractoriness.
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Affiliation(s)
- G Ravikumar
- Centre of Advanced Study in Zoology, Banaras Hindu University, Varanasi, India
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