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A S, Chauhan PS, Anandham R, Han GH, Sa T. Erratum to: Isolation, Characterization, and Use for Plant Growth Promotion Under Salt Stress, of ACC Deaminase-Producing Halotolerant Bacteria Derived from Coastal Soil. J Microbiol Biotechnol 2017; 27:1724. [PMID: 28958134 DOI: 10.4014/jmb.2017.2709.1724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
This erratum is being published to correct the error in the name of the strain in the paper by Siddikee et al. The name of the strain B. iodinum should be corrected as B. linens in title 'Isolation, Characterization, and Use for Plant Growth Promotion Under Salt Stress, of ACC Deaminase-Producing Halotolerant Bacteria Derived from Coastal Soil'.
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Kalita J, Misra UK, Bhoi SK, Chauhan PS, Sagar B. Possible role of transforming growth factor β in tuberculous meningitis. Cytokine 2016; 90:124-129. [PMID: 27865204 DOI: 10.1016/j.cyto.2016.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/07/2016] [Accepted: 11/05/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Transforming growth factor β (TGF-β) is an anti-inflammatory cytokine and its role in hydrocephalus and stoke has been suggested. Tuberculous meningitis (TBM) is associated with exudates, stroke, hydrocephalus and tuberculoma, but the role of TGF-β has not been evaluated in relation to these changes. AIM To evaluate the cerebrospinal fluid (CSF) TGF-β level in the patients with TBM, and correlate these with clinical findings, MRI changes, paradoxical response and outcome at 6months. METHODS TBM patients diagnosed on the basis of clinical, CSF and MRI criteria were prospectively included. The clinical details including duration of illness, seizures, focal motor deficit, Glasgow Coma Scale (GCS) score and stage of TBM were noted. Presence of exudate, hydrocephalus, tuberculoma and infarction in MRI was also noted. MRI was repeated at 3months and presence of paradoxical response was noted. Cerebrospinal fluid TGF-β was measured using ELISA on admission and repeated at 3months and these were compared with 20 controls. RESULTS TGF-β level was significantly higher in TBM compared to the controls (385.76±249.98Vs 177.85±29.03pg/ml, P<0.0001). TGF-β correlated with motor deficit, infarction and tuberculoma on admission but did not correlate with CSF abnormalities, drug induced hepatitis, paradoxical response and outcome. TGF-β level at 3months was significantly lower than the baseline but remained higher than the controls. CONCLUSION CSF TGF-β levels are elevated in TBM and correlate with infarction and tuberculoma.
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Chauhan PS, Singh R. Ovalbumin-induced allergic inflammation lead to structural alterations in mouse model and protective effects of intranasal curcumin: A comparative study. Allergol Immunopathol (Madr) 2016; 44:246-56. [PMID: 27046748 DOI: 10.1016/j.aller.2016.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 12/22/2015] [Accepted: 01/03/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND Antigen exposure and persistent inflammation leads to structural changes in the asthmatic airways which are collectively termed as "airway remodelling". Presently available asthma medications ameliorate inflammations but are unable to prevent or reverse the airway remodelling process as most of the treatment strategies are only focused on inflammation instead of remodelling. METHODS Curcumin, a phytochemical present in the rhizome of Curcuma longa is well known for its anti-inflammatory activity; however, the main drawback is its poor bioavailability which limits its therapeutic approval. So, the effect of nasal curcumin on acute and chronic asthma has been studied where short exposure to ovalbumin (4 days) represents acute phase whereas repeated exposures for longer (twice per week till 5 weeks) represents chronic asthma. Disodium cromoglycate (DSCG, 50mg/kg, i.p.) and dexamethasone (1mg/kg, i.p.) were used as standard drugs in acute and chronic model of asthma respectively. RESULTS OVA-induced airway inflammation initiated in acute stage led to remodelling due to persistent inflammation, epithelial and sub epithelial thickening (smooth muscle thickening), extracellular matrix (ECM) deposition, goblet cell hyperplasia and mucus plug formation. Intranasal curcumin is effective in inhibiting airway inflammation and remodelling both by maintaining the structural integrity of lungs in terms of inflammation, airway wall thickening and mucus production. CONCLUSION Our findings suggest that curcumin administered through nasal route might prove therapeutically efficient in inhibiting allergic airway inflammations and maintaining structural integrity in the mouse model of allergic asthma. This may lead to the development of curcumin aerosol in near future.
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Chowdhury SR, Chauhan PS, Dedkova LM, Bai X, Chen S, Talukder P, Hecht SM. Synthesis and Evaluation of a Library of Fluorescent Dipeptidomimetic Analogues as Substrates for Modified Bacterial Ribosomes. Biochemistry 2016; 55:2427-40. [PMID: 27050631 DOI: 10.1021/acs.biochem.6b00102] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Described herein are the synthesis and photophysical characterization of a library of aryl-substituted oxazole- and thiazole-based dipeptidomimetic analogues, and their incorporation into position 66 of green fluorescent protein (GFP) in lieu of the natural fluorophore. These fluorescent analogues resemble the fluorophore formed naturally by GFP. As anticipated, the photophysical properties of the analogues varied as a function of the substituents at the para position of the phenyl ring. The fluorescence emission wavelength maxima of compounds in the library varied from ∼365 nm (near-UV region) to ∼490 nm (visible region). The compounds also exhibited a large range of quantum yields (0.01-0.92). The analogues were used to activate a suppressor tRNACUA and were incorporated into position 66 of GFP using an in vitro protein biosynthesizing system that employed engineered ribosomes selected for their ability to incorporate dipeptides. Four analogues with interesting photophysical properties and reasonable suppression yields were chosen, and the fluorescent proteins (FPs) containing these fluorophores were prepared on a larger scale for more detailed study. When the FPs were compared with the respective aminoacyl-tRNAs and the actual dipeptide analogues, the FPs exhibited significantly enhanced fluorescence intensities at the same concentrations. Part of this was shown to be due to the presence of the fluorophores as an intrinsic element of the protein backbone. There were also characteristic shifts in the emission maxima, indicating the environmental sensitivity of these probes. Acridon-2-ylalanine and oxazole 1a were incorporated into positions 39 and 66 of GFP, respectively, and were shown to form an efficient Förster resonance energy transfer (FRET) pair, demonstrating that the analogues can be used as FRET probes.
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Singh R, Mahajan VK, Mehta KS, Thakur L, Chauhan PS, Gupta M, Rawat R. Profile of Rheumatological Manifestations in Leprosy in a Tertiary Care Hospital from Himachal Pradesh. INDIAN JOURNAL OF LEPROSY 2016; 88:13-19. [PMID: 29741821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The rheumatological manifestations of leprosy occur singly or in varying combinations, particularly during lepra reactions. Despite being third most common, these remain under diagnosed and under reported. This study has been carried out to study the spectrum of rheumatological manifestations in leprosy patients. One hundred consecutive patients of leprosy presenting during January to December 2013 were studied for rheumatological manifestations. Complete hemogram, serum biochemistry, urinalysis, rheumatoid factor, ASO titer, C-reactive protein, ANA, and x-rays for hands, feet, chest and involved joints were performed. These 100 (M:F 66:34) patients aged between 16-80 years had indeterminate (2 patients), TT (4 patients), BT (26 patients), BB (2 patients), and LL leprosy (32 patients). 27 patients had rheumatological manifestations; arthritis involving large or small joints in 23 patients being the commonest. 7 of 24 patients in type-1 lepra reaction had enthesitis in 3 patients and oligoarthritis in 4 patients. Rheumatoid arthritis-like polyarthritis was noted in 19 patients with type-2 reaction. Tenosynovitis, dactylitis, bony changes were also noted. Except for one case, these features were present in patients having lepra reactions. Rheumatoid factor in 14, ANA in 15, C-reactive protein in 45 cases was positive. ASO was positive 34 cases. Symmetrical polyarthritis involving small joints of hands and feet, oligoarthritis, enthesitis and dactylitis are common in leprosy particularly with borderline leprosy, type-2 lepra reaction especially in the presence of positive RAfactor.
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Mani VE, Chauhan PS, Kalita J, Bhoi SK, Misra UK. Is VEGF a marker of severity of scrub typhus infection? Eur J Clin Microbiol Infect Dis 2016; 35:305-10. [PMID: 26718940 DOI: 10.1007/s10096-015-2546-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/07/2015] [Indexed: 01/19/2023]
Abstract
Vascular endothelial growth factor (VEGF) and its receptors have been reported as severity markers of septicemia. Scrub typhus (ST) results in multi-organ dysfunction but the role of VEGF has not been evaluated. We report VEGF and its receptors in ST and its correlation with severity, outcome and laboratory findings. Thirty patients with ST diagnosed by solid phase immune chromatographic assay and Weil-Felix tests were included. Their clinical details, Glasgow Coma Scale (GCS), SOFA and modified Rankin Scale (mRS) scores and laboratory findings were noted. VEGF, VEGFR1 and VEGFR2 were done by ELISA at admission and repeated at 1 month. Outcome was defined at 1 month. Serum VEGF and VEGF-R1 levels were significantly higher and VEGFR2 was significantly lower in the ST patients compared to the controls. These levels significantly improved at 1 month. VEGF level correlated with SOFA score (p = 0.05) and SGPT (p = 0.04). VEGFR1 correlated with hemoglobin (p = 0.04), platelet count (p = 0.03), serum CK (p = 0.001), weakness (p = 0.04) and mRS score (p = 0.04). VEGFR2 did not correlate with any clinical or laboratory parameters. All the patients recovered with doxycycline. Serum VEGF and VEGFR1 levels increased in ST and suggest disease severity but do not predict outcome.
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Chauhan PS, Sacher JR, Weinreb SM. Synthesis of the tetracyclic skeleton of the Lycopodium alkaloid lycopladine H via a pivotal double hydroformylation/intramolecular reductive amination sequence. Org Lett 2015; 17:806-8. [PMID: 25658603 DOI: 10.1021/ol503571a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A synthesis of the complete tetracyclic framework of the structurally unique Lycopodium alkaloid lycopladine H has been accomplished using a strategy involving a double alkene hydroformylation/intramolecular reductive amination to form the azocane and spiro-piperidine moieties of the natural product.
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Chauhan PS, Weinreb SM. Convergent Approach to the Tetracyclic Core of the Apparicine Class of Indole Alkaloids via a Key Intermolecular Nitrosoalkene Conjugate Addition. J Org Chem 2014; 79:6389-93. [DOI: 10.1021/jo501067u] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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M. Weinreb S, S. Chauhan P, M. Majireck M. Regioselective α-Monochlorination of N-Protected-3-piperidones. HETEROCYCLES 2012. [DOI: 10.3987/com-11-s(p)23] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Bhagwat D, Kharya MD, Bani S, Pandey A, Chauhan PS, Kour K, Suri KA, Satti NK, Dutt P. Cyperus scariosus Chloroform Fraction Inhibits T cell Responses in Balb/C Mice. TROP J PHARM RES 2009. [DOI: 10.4314/tjpr.v8i5.48083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Das B, Chauhan PS, Seshadri M. Minimal sharing of Y-chromosome STR haplotypes among five endogamous population groups from western and southwestern India. Hum Biol 2005; 76:743-63. [PMID: 15757245 DOI: 10.1353/hub.2005.0003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We attempt to address the issue of genetic variation and the pattern of male gene flow among and between five Indian population groups of two different geographic and linguistic affiliations using Y-chromosome markers. We studied 221 males at three Y-chromosome biallelic loci and 184 males for the five Y-chromosome STRs. We observed 111 Y-chromosome STR haplotypes. An analysis of molecular variance (AMOVA) based on Y-chromosome STRs showed that the variation observed between the population groups belonging to two major regions (western and southwestern India) was 0.17%, which was significantly lower than the level of genetic variance among the five populations (0.59%) considered as a single group. Combined haplotype analysis of the five STRs and the biallelic locus 92R7 revealed minimal sharing of haplotypes among these five ethnic groups, irrespective of the similar origin of the linguistic and geographic affiliations; this minimal sharing indicates restricted male gene flow. As a consequence, most of the haplotypes were population specific. Network analysis showed that the haplotypes, which were shared between the populations, seem to have originated from different mutational pathways at different loci. Biallelic markers showed that all five ethnic groups have a similar ancestral origin despite their geographic and linguistic diversity.
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Das B, Chauhan PS, Seshadri M. Genetic variation observed at two tetrameric short tandem repeat loci on chromosome 12 (D12S66 and D12S67) among five distinct ethnic groups of India: detection of two new alleles. Ann Hum Biol 2002; 29:513-25. [PMID: 12396371 DOI: 10.1080/03014460110119766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The present investigation reports the genetic variation observed at two tetrameric short tandem repeat (STR) loci on chromosome 12 (D12S66 and D12S67) among five anthropologically distinct population groups of India. SUBJECTS AND METHODS A total of 277 random, normal and healthy volunteers were investigated for the D12S66 locus, and 236 for the locus D12S67, from five ethnic groups of India. Two of these belong to the state of Maharashtra in western India (Konkanastha Brahmins and Marathas) and three from the state of Kerala in South India (Nairs, Ezhavas and Muslims). DNA was extracted from peripheral blood samples, amplified by duplex polymerase chain reaction (PCR) and electrophoresed on 6% denaturing urea (7 M) gel electrophoresis. The analysis was performed on ALF Express DNA sequencer (Amersham Pharmacia Biotech) using Fragment Manager software. Statistical analysis was done by using Arlequin ver. 1.1. RESULTS At D12S66 locus, a total of nine alleles (8-17 repeats) and 27 genotypes were detected with an observed heterozygosity ranging from 0.55 to 0.91. At the D12S67 locus, nine alleles (36-44 repeats) and 33 genotypes were observed with a heterozygosity ranging from 0.74 to 0.89. Both the loci displayed high Power of Discrimination (PD) which ranged from 0.81 to 0.91 and Polymorphic Information Content (PIC) ranging from 0.68 to 0.84. At D12S66, two alleles were detected for the first time in these population groups which were not reported earlier. The level of gene differentiation (G(ST) value, 0.02) was moderate at these two loci, indicating a close relationship among the population groups. CONCLUSIONS From this investigation, it is concluded that both the tetrameric loci are highly polymorphic and informative, and can be used for the characterization of the Indian population groups in addition to other well-studied STR loci.
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Das B, Ghosh A, Chauhan PS, Seshadri M. Genetic polymorphism study at four minisatellite loci (D1S80, D17S5, D19S20, and APOB) among five Indian population groups. Hum Biol 2002; 74:345-61. [PMID: 12180760 DOI: 10.1353/hub.2002.0028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The present study reports the genetic variation observed among five anthropologically distinct population groups of India, using four highly polymorphic minisatellite loci (D1S80, D17S5, D19S20, and APOB 3' VNTR) in order to examine the effect of geographical and linguistic affiliations on the genetic affinities among these groups. Random individuals from five ethnic groups were studied; the sample size ranged from 235 to 364. The population groups belong to two geographically separated regions of India, the state of Maharashtra (western India) and the state of Kerala (southern India). The two Maharashtrian groups (Konkanastha Brahmins and Marathas) speak "Marathi," an Indo-European language, whereas the three Kerala population groups (Nairs, Ezhavas, and Muslims) speak "Malayalam," an Indo-Dravidian language. Genomic DNA was extracted from peripheral blood samples and analyzed using amplified fragment length polymorphism (Amp-FLP) technique. All four loci displayed high heterozygosity with average heterozygosity in the range of 0.82 to 0.84. The Polymorphic Information Content and Power of Discrimination were > or = 0.75 and > or = 0.80, respectively. The coefficient of gene differentiation was found to be low (average G(ST) = 1.2%; range between 0.6% at D1S80 locus to 1.6% at APOB 3' VNTR locus) across the loci, indicating close affinity among the population groups. The neighbor-joining tree revealed two clear clusters, one for the two Maharashtrian population groups and the other for the three Kerala population groups. The results obtained are in conformity with the geographical and linguistic backgrounds of the studied populations.
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Das B, Chauhan PS, Seshadri M. Y-chromosomal STR haplotypes in two population groups of Kerala in south India. J Forensic Sci 2002; 47:690-1. [PMID: 12051368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Das B, Chauhan PS, Seshadri M. Population database of Y-chromosomal haplotypes at five microsatellites among two distinct ethnic groups of western India. J Forensic Sci 2002; 47:692-3. [PMID: 12051369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Das B, Chauhan PS, Seshadri M. Allele frequency distribution at five Y-chromosomal short tandem repeat loci among five distinct ethnic groups of India. J Forensic Sci 2002; 47:410-2. [PMID: 11908623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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Venkat S, Apte SK, Chaubey RC, Chauhan PS. Radioadaptive response in human lymphocytes in vitro. J Environ Pathol Toxicol Oncol 2002; 20:165-75. [PMID: 11797826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Exposure to low doses of radiation and/or chemicals can prime an organism to withstand the stress of a subsequent exposure to higher doses of the same agent. In the case of radiation, this phenomenon has been called radioadaptive response. Cytogenetic studies have been undertaken in human lymphocytes to investigate adaptive response (AR) to ionizing radiation, in particular to seek the role of variables such as priming dose, cell cycle stage, and age and gender of the donor. We demonstrated that pre-exposure of lymphocytes in whole blood cultures to very low doses in the range of about 1 cGy (priming or adaptive dose [AD]) reduced the frequency of micronuclei in binucleated cells induced by 100 cGy--that is, produced an AR in these cells in vitro. However, pre-exposure of cells to 10.0 cGy did not reduce the chromosomal damage (micronuclei) induced by the challenging dose (CD) of 100 cGy under the same protocol, thus exhibiting an inverse dose-response relationship. There was marked variability in the AR among the individuals investigated in the study. The extent of AR also depended on the stage of cell cycle exposed to the CD of radiation. Maximum AR was observed when CD of 100 cGy was given 4 hours after AD, 30 hours following the mitogenic stimulation of lymphocytes. The least AR was observed when CD was given 48 hours after stimulation. Interestingly, AR was also found to be dependent on the age of the donor, a decrease in AR being observed with an increasing age. No significant difference in AR was observed between male and female donors. To understand the molecular events underlying AR, protein synthesis patterns were studied in human lymphocytes subjected to mitogen, heat, or radiation stress. Heat shock (45 degrees C, for 15 min) induced 7 proteins with molecular weights ranging from 40 to 80 kDa, while treatment with phytohemagglutinin (40 microg/mL) showed induction of 2 proteins of molecular weights 38 and 48 kDa, respectively. However, exposure of human lymphocyte cultures to gamma radiation did not significantly induce synthesis of any protein, up to 800 cGy dose. Lack of induction of proteins by gamma radiation in human lymphocytes contrasts with the previous reports showing X-ray radiation-enhanced gene expression in melanoma cells and/or human tumor fibroblasts.
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Das B, Chauhan PS, Seshadri M. Allele frequency distribution of two minisatellite loci (D19S20 and apoB 3' VNTR) among five distinct population groups of India. J Forensic Sci 2002; 47:229-31. [PMID: 12064663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Das B, Ghosh A, Chauhan PS, Seshadri M. Population data of two minisatellite loci (D1S80 and D17S5) among five distinct ethnic groups of India. J Forensic Sci 2001; 46:1518-9. [PMID: 11714173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Kumar SS, Ghosh A, Devasagayam TP, Chauhan PS. Effect of vanillin on methylene blue plus light-induced single-strand breaks in plasmid pBR322 DNA. Mutat Res 2000; 469:207-14. [PMID: 10984681 DOI: 10.1016/s1383-5718(00)00074-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The ability of vanillin (4-hydroxy-3-methoxybenzaldehyde), a naturally occurring food flavouring agent, in inhibiting photosensitization-induced single-strand breaks (ssbs) in plasmid pBR322 DNA has been examined in an in vitro system, independent of DNA repair/replication processes. Photosensitization of DNA with methylene blue, visible light and oxygen, induced ssbs resulting in the production of open circular form (OC form) in a concentration-dependent manner. The yield of OC form induced by photosensitization was increased several-fold by deuteration of the buffer and was found to be inhibited by sodium azide, a scavenger of singlet oxygen (1O(2)). Vanillin, per se, did not induce but inhibited photosensitization-induced ssbs in plasmid DNA, at millimolar concentrations. The inhibitory effect of vanillin was both concentration- and time-dependent. On a molar basis, vanillin was, however, less effective than trolox, a water-soluble analogue of alpha-tocopherol. Photosensitization by methylene blue system generates singlet oxygen, as one of the major components of ROS. Therefore, interaction of singlet oxygen with vanillin was investigated. The rate constant of vanillin with 1O(2) was estimated to be 5.93x10(7)M(-1)s(-1) and that of sodium azide as 2. 7x10(8)M(-1)s(-1). The present investigations show that vanillin can protect against photosensitization-induced ssbs in the plasmid pBR322 DNA, and this effect may partly be due to its ability to scavenge 1O(2).
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Krishnaja AP, Chauhan PS. Quinacrine dihydrochloride, the non-surgical female sterilant induces dicentrics, rings, and marker chromosomes in human peripheral blood lymphocytes treated in vitro: a preliminary report. Mutat Res 2000; 466:43-50. [PMID: 10751724 DOI: 10.1016/s1383-5718(99)00237-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the last decade, quinacrine dihydrochloride (QDH) has been promoted for clinical trials as a much needed non-surgical female sterilant, largely in the Third World. Recently, however, these human trials have come under severe criticism due to lack of adequate evidence of biological safety of QDH, particularly of its genotoxicity in mammalian systems. In the present study, the cytogenetic analysis of QDH-treated human lymphocytes, grown as whole blood cultures in vitro, surprisingly showed a wide range of chromosomal aberrations. At a concentration of 3.0 and 6.0 microg/ml in culture, QDH was cytotoxic, as shown by the very few analyzable metaphases that could be observed. G(0) lymphocytes, treated with 0. 6 microg/ml QDH, exhibited chromosome aberrations including dicentrics, ring configurations, translocations, inversions, and marker chromosomes. Near haploid, polyploid, and endoreduplicated cells were also observed. All the rings appeared to be formed as a result of telomere fusion/association. Twenty percent of the dicentrics observed also indicated telomere fusion/association in the D and G groups of chromosomes. Overall, a frequent involvement of chromosomes 1, 2, and 3 in both unstable and stable chromosome rearrangements was also observed. Exposure of 72-h cultures to 0.45 microg/ml QDH at 69 h resulted in an accumulation of C-metaphases, suggesting that probably QDH behaves as a mitotic spindle inhibitor. The G(2) lymphocytes from two donors exposed to 0.6, 1.5 or 3.0 microg/ml of QDH showed no increase in chromatid aberrations in two donors. However, QDH at 0.6 microg/ml increased the frequency of micronucleated binucleate cells. No increase in sister chromatid exchanges was observed at this concentration. Though preliminary, these observations demonstrate the chromosome damaging ability of QDH in human lymphocytes treated in vitro. Surprisingly, like ionizing radiation, QDH acted by an S-phase-independent mechanism, unlike most of the chemical mutagens. These results warrant detailed investigations on the cytogenetic effects of QDH in vitro, as well as among women exposed to this agent during clinical trials for non-surgical sterilization. The interesting cytogenetic profile of QDH deserves to be pursued and the underlying mechanisms, in particular, the DNA topoisomerase II inhibitory effect, if any, needs to be elucidated.
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Jaikrishan G, Andrews VJ, Thampi MV, Koya PK, Rajan VK, Chauhan PS. Genetic monitoring of the human population from high-level natural radiation areas of Kerala on the southwest coast of India. I. Prevalence of congenital malformations in newborns. Radiat Res 1999; 152:S149-53. [PMID: 10564958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
In the densely populated monazite-bearing sands of Kerala, on the southwest coast of India, natural radiation dose rates range from 1. 0 to over 35.0 mGy per year in certain well-defined high-level natural radiation areas. As a part of the program to assess the health effects of this naturally occurring high-level natural radiation on human populations, monitoring of newborns is being undertaken to determine the incidence of congenital malformations. From August 1995 to December 1998, a total of 36,805 newborns were screened, including 212 (0.58%) stillbirths. There were 36,263 singletons, 536 (1.45%) twins, and 6 born as triplets. The overall incidence of malformations was 1.46% and was dependent on maternal age. The stillborns exhibited a very high malformation rate of 20.75% compared to 1.35% among the live births. Likewise, twins also had a higher malformation rate (2.99%) compared to singletons (1.44%). About 3.5% of the newborns originated from consanguineous marriages. Consanguinity also led to a relatively higher rate of malformations (1.97%) as well as of stillbirths (1.18%). About 92% of the deliveries took place by the maternal age of 29 years and only 1.2% among women above 34 years old. The stratification of newborns with malformations, stillbirths or twinning showed no correlation with the natural radiation levels in the different areas. Thus no significant differences were observed in any of the reproductive parameters between the two population groups based on the monitoring of 26,151 newborns from high-level natural radiation and 10,654 from normal-level natural radiation (dose rate </=1.5 mGy/year) areas of the Kerala coast.
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Cheriyan VD, Kurien CJ, Das B, Ramachandran EN, Karuppasamy CV, Thampi MV, George KP, Kesavan PC, Koya PK, Chauhan PS. Genetic monitoring of the human population from high-level natural radiation areas of Kerala on the southwest coast of India. II. Incidence of numerical and structural chromosomal aberrations in the lymphocytes of newborns. Radiat Res 1999; 152:S154-8. [PMID: 10564959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Cytogenetic studies using cord blood samples from newborns from high-level natural radiation areas of the Kerala coast in Southwest India have been in progress since 1986. A total of 963,940 metaphases from 10,230 newborns have been screened for various types of chromosomal aberrations. Comparison of 8,493 newborns (804,212 cells) from high-level natural radiation areas (dose rate >1.5 mGy/year) and 1,737 newborns (159,728 cells) from normal-level natural radiation areas (</=1.5 mGy/year) did not show any significant difference in the frequency of dicentrics, translocations, inversions or other types of aberrations known to be associated with radiation exposure. The cytogenetic studies were continued for constitutional anomalies using karyotype analysis, and scoring of 16,169 newborns has been completed. The overall frequency of constitutional anomalies was 4.95 +/- 0.55 per 1,000 newborns, which is comparable to the incidence reported in the literature. Within the limitations of sample size, the frequencies of total autosomal and sex aneuploids as well as structural anomalies were comparable between the high-level and normal-level natural radiation areas. A striking observation was the presence of rogue cells, the rarely occurring metaphases with a high level of chromosomal damage, which have not been reported previously among newborns.
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Kumar SS, Chaubey RC, Devasagayam TP, Priyadarsini KI, Chauhan PS. Inhibition of radiation-induced DNA damage in plasmid pBR322 by chlorophyllin and possible mechanism(s) of action. Mutat Res 1999; 425:71-9. [PMID: 10082917 DOI: 10.1016/s0027-5107(98)00250-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Naturally occurring compounds capable of protecting DNA against ionizing radiation and chemical mutagens have considerable potential for prevention of mutation-based health impairment including cancer and other degenerative diseases. Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, has been examined for its ability to protect DNA against radiation induced strand breaks using an in vitro plasmid DNA system. Gamma-radiation, up to a dose of 6 Gy (dose rate 1.25 Gy/min), induced a dose-dependent increase in single-strand breaks (ssbs) in plasmid pBR322 DNA. CHL per se did not induce, but inhibited radiation-induced ssbs in a concentration-dependent manner; 500 microM giving about 90% protection. The protection afforded by CHL was comparatively less than that of trolox, a water-soluble analogue of alpha-tocopherol. To elucidate the underlying mechanism(s), reaction of CHL with the radiation-derived hydroxyl radical (.OH) and deoxyribose peroxyl radical (ROO.) was studied by pulse radiolysis. CHL exhibited a rate constant of 6.1+/-0.4x109 M-1 s-1 with.OH and 5.0+/-1.3x107 M-1 s-1 with ROO. To our knowledge, this is the first report providing direct evidence of free radical-scavenging properties of CHL. The results showed that CHL, effectively protects plasmid DNA against ionizing radiation, in an in vitro system independent of DNA repair or other cellular defense mechanisms. The ability of CHL to scavenge. OH and ROO., may contribute to its protective effects against radiation induced DNA damage in the pBR322 system.
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Rao UN, Aravindakshan M, Satyanarayan V, Chauhan PS. Genotype- and gender-dependent hepatic alcohol dehydrogenase (ADH) activity in developing mice. Alcohol 1997; 14:527-31. [PMID: 9401665 DOI: 10.1016/s0741-8329(97)00040-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ethanol is metabolized in human and rodent liver primarily by the enzyme alcohol dehydrogenase (ADH). Hepatic ADH activity in adult males and females of seven inbred strains of mice was determined to examine genotype- and sex-dependent variability among the strains and the level of sexual dimorphism in each of the strains. ADH activity varied considerably among the strains, which could be categorized into high-activity strains C57BL/6, C57Brcd, and Swiss, and relatively low-activity strains C3H, CBA, and DBA. Adult Swiss, AKR, C57BL/6, and DBA females exhibited significantly higher levels of hepatic ADH than their male counterparts, whereas no gender differences were seen in C3H, CBA, and C57Brcd. Young mice of high and/or low ADH activity strains viz. C57BL/6 and C3H did not exhibit gender differences in ADH activity at weanling but the enzyme levels increased by sixth week in females and remained higher thereafter. The progeny of a high-activity strain with sexual dimorphism (C57BL/6) and a low-activity strain lacking gender difference (C3H) exhibited intermediate levels of ADH and age-dependent sexual dimorphism.
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