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Ramanathan G, Gupta S, Thielmann I, Pleines I, Varga-Szabo D, May F, Mannhalter C, Dietrich A, Nieswandt B, Braun A. Defective diacylglycerol-induced Ca2+ entry but normal agonist-induced activation responses in TRPC6-deficient mouse platelets. J Thromb Haemost 2012; 10:419-29. [PMID: 22176814 DOI: 10.1111/j.1538-7836.2011.04596.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Platelet adhesion, activation and aggregation at sites of vascular injury are essential processes for primary hemostasis. Elevation of the intracellular Ca(2+) concentration is a central event in platelet activation but the underlying mechanisms are not fully understood. Store-operated calcium entry (SOCE) through Orai1 was shown to be the main Ca(2+) influx pathway in murine platelets, but there are additional non-store-operated Ca(2+) (non-SOC) and receptor operated Ca(2+) (ROC) channels expressed in the platelet plasma membrane. OBJECTIVE Canonical transient receptor potential (TRPC) channel 6 is found both in human and murine platelets and has been proposed to mediate diacylglycerol (DAG) activated ROCE but also a role in the regulation of SOCE has been suggested. METHODS To investigate the function of TRPC6 in platelet Ca(2+) signaling and activation, we analyzed platelets from mice deficient in TRPC6 using a wide range of in vitro and in vivo assays. RESULTS In the mutant platelets, DAG activated Ca(2+) influx was found to be abolished. However, this did not significantly affect SOCE or agonist induced Ca(2+) responses. Platelet function in vitro and in vivo was also unaltered in the absence of TRPC6. CONCLUSION Our results indicate that DAG activated ROCE is mediated exclusively by TRPC6 in murine platelets, but this Ca(2+) influx has no major functional relevance for hemostasis and thrombosis. Further, in contrast to previous suggestions, based on studies with human platelets, TRPC6 appears to play an insignificant role in the regulation of SOCE in murine platelets.
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Ramanathan G, Yu C, Osei E, Nicolaides KH. Ultrasound examination at 37 weeks' gestation in the prediction of pregnancy outcome: the value of cervical assessment. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2003; 22:598-603. [PMID: 14689532 DOI: 10.1002/uog.913] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE To examine the potential value of routine measurement of cervical length in singleton low-risk pregnancies at 37 weeks of gestation in the prediction of onset and outcome of labor. METHODS Cervical length was measured by transvaginal sonography at 37 weeks in 1571 singleton low-risk pregnancies. Outcome measures were gestation at spontaneous onset of labor, post-term delivery, duration of labor and mode of delivery. RESULTS The median cervical length at 37 weeks was 30 mm and there was a significant association between cervical length and gestation at delivery, which increased from a mean of 38 weeks for cervical length of 10 mm to 41 weeks for cervical length of 35 mm. The incidence of delivery after 40 weeks and 10 days was 296 (18.8%) and the incidence increased with cervical length at 37 weeks from 0% to 6%, 35% and 68% for respective cervical lengths of < 20, 21-30, 31-40 and 41-50 mm. In the pregnancies with spontaneous onset of labor the incidence of Cesarean section for failure to progress increased from 3.6% to 6.0%, 6.4% and 11.8% for cervical lengths of < 20, 21-30, 31-40 and 41-50 mm, respectively. In the pregnancies requiring induction for post-term the incidence of Cesarean section for failed induction or failure to progress increased from 7.5% to 20.1% to 25.0% for cervical lengths of 21-30, 31-40 and 41-50 mm, respectively. CONCLUSION Measurement of cervical length at 37 weeks can define the likelihood of spontaneous delivery before 40 weeks and 10 days and the risk of Cesarean section in those requiring induction for prolonged pregnancy.
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Ramanathan G, Elumalai R, Periyasamy S, Lakkakula BVKS. Renin gene rs1464816 polymorphism contributes to chronic kidney disease progression in ADPKD. J Biomed Sci 2016; 23:1. [PMID: 26753721 PMCID: PMC4710007 DOI: 10.1186/s12929-015-0217-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 12/28/2015] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder and is a common genetic cause of chronic renal failure in children and adults. The enzyme renin plays a key role in the RAAS cascade and an important role in the development of hypertension and progression of renal disease in ADPKD. The present study is aimed to investigate the potential modifier effect of REN gene polymorphisms on the progression of chronic kidney disease (CKD) in ADPKD. METHODS We analyzed 102 ADPKD patients and 106 healthy controls from the same geographic area. FRET-based KASPar single-nucleotide polymorphism (SNP) genotyping assays for REN gene tag-SNPs (rs2887284, rs2368564, rs1464816, rs7521667, rs10900555, rs6693954, rs6676670 and rs11571078) were performed. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Haplotype frequencies and LD measures were estimated by using the software Haploview. Mantel-Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms. RESULTS Of the eight tag-SNPs genotyped, the rs10900555 polymorphism deviated from the Hardy-Weinberg equilibrium in controls. The presence of ADPKD in general was not significantly associated with the REN tag-SNPs included in this study. Linkage disequilibrium analysis yielded three haplotype blocks and the haplotypes of the respective blocks are not statistically different between ADPKD and controls. In multivariate analysis, the rs1464816 TG genotype showed a significant association with the advancement of CKD in ADPKD (OR = 4.80; 95 % CI = 1.30-17.82; p = 0.019). CONCLUSIONS The present study provides evidence that the rs1464816 polymorphism in REN is associated with CKD progression in ADPKD.
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Mukherjee AG, Wanjari UR, Namachivayam A, Murali R, Prabakaran DS, Ganesan R, Renu K, Dey A, Vellingiri B, Ramanathan G, Doss C. GP, Gopalakrishnan AV. Role of Immune Cells and Receptors in Cancer Treatment: An Immunotherapeutic Approach. Vaccines (Basel) 2022; 10:1493. [PMID: 36146572 PMCID: PMC9502517 DOI: 10.3390/vaccines10091493] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 12/07/2022] Open
Abstract
Cancer immunotherapy moderates the immune system's ability to fight cancer. Due to its extreme complexity, scientists are working to put together all the puzzle pieces to get a clearer picture of the immune system. Shreds of available evidence show the connection between cancer and the immune system. Immune responses to tumors and lymphoid malignancies are influenced by B cells, γδT cells, NK cells, and dendritic cells (DCs). Cancer immunotherapy, which encompasses adoptive cancer therapy, monoclonal antibodies (mAbs), immune checkpoint therapy, and CART cells, has revolutionized contemporary cancer treatment. This article reviews recent developments in immune cell regulation and cancer immunotherapy. Various options are available to treat many diseases, particularly cancer, due to the progress in various immunotherapies, such as monoclonal antibodies, recombinant proteins, vaccinations (both preventative and curative), cellular immunotherapies, and cytokines.
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Review |
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Samba Reddy D, Ramanathan G. Finasteride inhibits the disease-modifying activity of progesterone in the hippocampus kindling model of epileptogenesis. Epilepsy Behav 2012; 25:92-7. [PMID: 22835430 PMCID: PMC3444667 DOI: 10.1016/j.yebeh.2012.05.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/24/2012] [Accepted: 05/26/2012] [Indexed: 11/19/2022]
Abstract
Progesterone (P) plays an important role in seizure susceptibility in women with epilepsy. Preclinical and experimental studies suggest that P appears to interrupt epileptogenesis, which is a process whereby a normal brain becomes progressively susceptible to recurrent, unprovoked seizures due to precipitating risk factors. Progesterone has not been investigated widely for its potential disease-modifying activity in epileptogenic models. Recently, P has been shown to exert disease-modifying effects in the kindling model of epileptogenesis. However, the mechanisms underlying the protective effects of P against epileptogenesis remain unclear. In this study, we investigated the role of P-derived neurosteroids in the disease-modifying activity of P. It is hypothesized that 5α-reductase converts P to allopregnanolone and related neurosteroids that retard epileptogenesis in the brain. To test this hypothesis, we utilized the mouse hippocampus kindling model of epileptogenesis and investigated the effect of finasteride, a 5α-reductase and neurosteroid synthesis inhibitor. Progesterone markedly retarded the development of epileptogenesis and inhibited the rate of kindling acquisition to elicit stage 5 seizures. Pretreatment with finasteride led to complete inhibition of the P-induced retardation of the limbic epileptogenesis in mice. Finasteride did not significantly influence the acute seizure expression in fully kindled mice expressing stage 5 seizures. Thus, neurosteroids that potentiate phasic and tonic inhibition in the hippocampus, such as allopregnanolone, may mediate the disease-modifying effect of P, indicating a new role of neurosteroids in acquired limbic epileptogenesis and temporal lobe epilepsy.
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Hussain H, Ramachandran V, Ravi S, Sajan T, Ehambaram K, Gurramkonda VB, Ramanathan G, Bhaskar LV. TCF7L2 rs7903146 polymorphism and diabetic nephropathy association is not independent of type 2 diabetes--a study in a south Indian population and meta-analysis. ENDOKRYNOLOGIA POLSKA 2014; 65:298-305. [PMID: 25185853 DOI: 10.5603/ep.2014.0041] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 08/29/2014] [Indexed: 11/25/2022]
Abstract
Diabetic nephropathy (DN) is a chronic microangiopathic complication of both type 1 (T1DM) and type 2 diabetes mellitus (T2DM). The TCF7L2 gene has been reported to be associated with type 2 diabetes risk. We aimed to investigate the impact of TCF7L2 gene on the susceptibility of T2DM and DN in a south Indian population. Plus to evaluate the association of rs7903146 in the TCF7L2 gene with T2DM in the Indian population. The subjects recruited for this included 55 diabetic cases with diabetic nephropathy, 68 diabetic cases without nephropathy, and 82 non-diabetic healthy controls. Genomic DNA was isolated from blood and genotyping of TCF7L2 rs7903146 was performed by PCR-RFLP analysis. A literature survey was carried out into the effect of rs7903146 on genetic susceptibility to T2DM in Indian populations and we then performed a meta-analysis in order to evaluate its association with T2DM. Analysis of TCF7L2 rs7903146 in normal controls and diabetics with or without nephropathy demonstrated that the 'T' allele is associated with both diabetes (p = 0.049) and DN (p = 0.024), but this association is not independent of T2DM. Meta-analysis showed that the mutant allele and genotypes are associated with T2DM in Indian populations. In summary, a significant association exists between the 'T' allele and DN, but this association is not independent of T2DM. Pooled meta-analysis of studies on rs7903146 and T2DM confirmed that rs7903146 is significantly associated with susceptibility to T2DM in Indian populations.
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Lye JE, Harty PD, Butler DJ, Crosbie JC, Livingstone J, Poole CM, Ramanathan G, Wright T, Stevenson AW. Absolute dosimetry on a dynamically scanned sample for synchrotron radiotherapy using graphite calorimetry and ionization chambers. Phys Med Biol 2016; 61:4201-22. [DOI: 10.1088/0031-9155/61/11/4201] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mukherjee AG, Wanjari UR, Kannampuzha S, Das S, Murali R, Namachivayam A, Renu K, Ramanathan G, Doss C GP, Vellingiri B, Dey A, Valsala Gopalakrishnan A. The pathophysiological and immunological background of the monkeypox virus infection: An update. J Med Virol 2023; 95:e28206. [PMID: 36217803 DOI: 10.1002/jmv.28206] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 01/18/2023]
Abstract
In addition to the COVID-19 waves, the globe is facing global monkeypox (MPX) outbreak. MPX is an uncommon zoonotic infection characterized by symptoms similar to smallpox. It is caused by the monkeypox virus (MPXV), a double-stranded DNA virus that belongs to the genus Orthopoxvirus (OPXV). MPXV, which causes human disease, has been confined to Africa for many years, with only a few isolated cases in other areas. Outside of Africa, the continuing MPXV outbreak in multiple countries in 2022 is the greatest in recorded history. The current outbreak, with over 10 000 confirmed cases in over 50 countries between May and July 2022, demonstrates that MPXV may travel rapidly among humans and pose a danger to human health worldwide. The rapid spread of such outbreaks in recent times has elevated MPX to the status of a rising zoonotic disease with significant epidemic potential. While the MPXV is not as deadly or contagious as the variola virus that causes smallpox, it poses a threat because it could evolve into a more potent human pathogen. This review assesses the potential threat to the human population and provides a brief overview of what is currently known about this reemerging virus. By analyzing the biological effects of MPXV on human health, its shifting epidemiological footprint, and currently available therapeutic options, this review has presented the most recent insights into the biology of the virus. This study also clarifies the key potential causes that could be to blame for the present MPX outbreak and draw attention to major research questions and promising new avenues for combating the current MPX epidemic.
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Review |
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Lye JE, Butler DJ, Ramanathan G, Franich RD. Spectral differences in 6 MV beams with matched PDDs and the effect on chamber response. Phys Med Biol 2012; 57:7599-614. [DOI: 10.1088/0031-9155/57/22/7599] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ramanathan G, Harichandana B, Kannan S, Elumalai R, Sfd P. Association between end-stage diabetic nephropathy and MTHFR (C677T and A1298C) gene polymorphisms. Nephrology (Carlton) 2019; 24:155-159. [PMID: 29227003 DOI: 10.1111/nep.13208] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2017] [Indexed: 11/29/2022]
Abstract
AIM Methylenetetrahydrofolate reductase (MTHFR) is a regulatory enzyme of homocysteine metabolism. The C677T and A1298C polymorphism of the MTHFR gene has been reported to be associated with elevated plasma homocysteine in patients with Diabetic nephropathy. This study aimed to investigate the influence of the C677T and A1298C polymorphisms on the progression chronic kidney disease in diabetic nephropathy of south Indian population. METHODS We genotyped 145 DN cases and 100 controls for the C677T and A1298C polymorphisms using PCR-RFLP based protocols, and all diabetic nephropathy cases divided into two groups based on CKD stages: 60 DN cases were early stage (CKD1 to CKD3) and 85 DN cases were advanced stage (CKD4 and CKD5). Association χ2 and univariate analysis were performed. RESULTS The C677T (OR = 4.2; 95% CI = 2.31-7.64 and P = 0.001) and A1298C (OR = 2.8; 95% CI = 1.05-7.57 and P = 0.033) polymorphism was shown that the significant association between the cases and control. Furthermore, the MTHFR gene polymorphism C677T (OR = 2.48; 95% CI = 1.25-4.9 and P = 0.008) was observed that the significant contribution of the progression of CKD in DN. CONCLUSION These findings suggest that the C677T and A1298C polymorphism of MTHFR gene was associated with diabetic nephropathy in a south Indian population. Furthermore, the present study provides evidence that the C677T polymorphism was associated with CKD progression in DN.
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Journal Article |
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Yamini V, Shanmugam V, Rameshpathy M, Venkatraman G, Ramanathan G, Al Garalleh H, Hashmi A, Brindhadevi K, Devi Rajeswari V. Environmental effects and interaction of nanoparticles on beneficial soil and aquatic microorganisms. ENVIRONMENTAL RESEARCH 2023; 236:116776. [PMID: 37517486 DOI: 10.1016/j.envres.2023.116776] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
A steadily increasing production volume of nanoparticles reflects their numerous industrial and domestic applications. These economic successes come with the potential adverse effects on natural systems that are associated with their presence in the environment. Biological activities and effects of nanoparticles are affected by their entry method together with their specificities like their size, shape, charge, area, and chemical composition. Particles can be classified as safe or dangerous depending on their specific properties. As both aquatic and terrestrial systems suffer from organic and inorganic contamination, nanoparticles remain a sink for these contaminants. Researching the sources, synthesis, fate, and toxicity of nanoparticles has advanced significantly during the last ten years. We summarise nanoparticle pathways throughout the ecosystem and their interactions with beneficial microorganisms in this research. The prevalence of nanoparticles in the ecosystem causes beneficial microorganisms to become hazardous to their cells, which prevents the synthesis of bioactive molecules from undergoing molecular modifications and diminishes the microbe population. Recently, observed concentrations in the field could support predictions of ambient concentrations based on modeling methodologies. The aim is to illustrate the beneficial and negative effects that nanoparticles have on aqueous and terrestrial ecosystems, as well as the methods utilized to reduce their toxicity.
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Review |
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Harty PD, Lye JE, Ramanathan G, Butler DJ, Hall CJ, Stevenson AW, Johnston PN. Absolute x-ray dosimetry on a synchrotron medical beam line with a graphite calorimeter. Med Phys 2014; 41:052101. [DOI: 10.1118/1.4870387] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Das S, Doss C GP, Fletcher J, Kannangai R, Abraham P, Ramanathan G. The Impact of Human Papilloma Virus on Human Reproductive Health and the Effect on Male Infertility: An updated Review. J Med Virol 2023; 95:e28697. [PMID: 36951428 DOI: 10.1002/jmv.28697] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/25/2023] [Accepted: 03/20/2023] [Indexed: 03/24/2023]
Abstract
It is believed that human papilloma virus infection (HPV), which is caused by the DNA virus, is the most prominent factor contributing to sexually transmitted disease (STD) in the world, with males having a prevalence rate of 3.5-45% while that women are 2-44%. Infertility is a rising problem on a global basis, affecting anywhere from 10-30 % of couples who have reached reproductive age. This study aims to investigate the existing research on HPV, its connection to male infertility, and how it could be a helpful tool for medical professionals managing HPV in the context of reproductive health care. Infection with HPV has been identified as a risk factor for several spontaneous abortions; however, there is a lack of evidence on how HPV influences individuals undergoing assisted reproductive technology (ART) in terms of live births. The significance of the immune response to HPV-infected male reproductive system cells and its effect on embryos, as well as the oxidative stress generated by high-risk HPV DNA damage and genomic instability, is discussed in this review. Further, the association between male individuals infected with HPV and asthenozoospermia should provide a compelling case for vaccinating young people against HPV. This article is protected by copyright. All rights reserved.
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Review |
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Ravikumar S, Ramanathan G, Gnanadesigan M, Ramu A, Vijayakumar V. In vitro antiplasmodial activity of methanolic extracts from seaweeds of South West Coast of India. ASIAN PAC J TROP MED 2011; 4:862-5. [PMID: 22078947 DOI: 10.1016/s1995-7645(11)60209-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/25/2011] [Accepted: 09/15/2011] [Indexed: 10/15/2022] Open
Abstract
OBJECTIVE To identify the in vitro antiplasmodial activity of seaweed plants against Plasmodium falciparumstrains. METHODS A total of eight seaweeds were collected from Kanyakumari district, Tamilnadu, India. The in vitro antiplasmodial activity was performed in 96 well plates against Plasmodium falciparum, and preliminary phytochemcial analysis were performed for the extracts. RESULTS Of the selected plants Enteromorpha intestinalis (2.61%) showed maximum percentage of extraction. The minimum concentration of inhibitory (IC50) value was observed with Chaetomorpha antennina [(26.37±4.14) μg/mL] further, the positive controls such as chloroquine and artemether showed antiplasmodial activities (IC50) with (19.10±5.93) and (6.03±0.21) μg/mL concentrations, respectively. The preliminary phytochemical analysis of the seaweed extracts showed a variety of phytochemical constituents such as carboxylic acids, phenols, protein, resins, steroids and sugars. CONCLUSIONS The antiplasmodial activity of the seaweed extract might due to the presence of sugars and phenolic compounds. From the present findings, it is concluded that, the seaweed extract of Chaetomorpha antennina can be further used as a putative antiplasmodial drugs in near future.
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Das S, Devi Rajeswari V, Venkatraman G, Elumalai R, Dhanasekaran S, Ramanathan G. Current updates on metabolites and its interlinked pathways as biomarkers for diabetic kidney disease: A systematic review. Transl Res 2024; 265:71-87. [PMID: 37952771 DOI: 10.1016/j.trsl.2023.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023]
Abstract
Diabetic kidney disease (DKD) is a major microvascular complication of diabetes mellitus (DM) that poses a serious risk as it can lead to end-stage renal disease (ESRD). DKD is linked to changes in the diversity, composition, and functionality of the microbiota present in the gastrointestinal tract. The interplay between the gut microbiota and the host organism is primarily facilitated by metabolites generated by microbial metabolic processes from both dietary substrates and endogenous host compounds. The production of numerous metabolites by the gut microbiota is a crucial factor in the pathogenesis of DKD. However, a comprehensive understanding of the precise mechanisms by which gut microbiota and its metabolites contribute to the onset and progression of DKD remains incomplete. This review will provide a summary of the current scenario of metabolites in DKD and the impact of these metabolites on DKD progression. We will discuss in detail the primary and gut-derived metabolites in DKD, and the mechanisms of the metabolites involved in DKD progression. Further, we will address the importance of metabolomics in helping identify potential DKD markers. Furthermore, the possible therapeutic interventions and research gaps will be highlighted.
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Systematic Review |
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Lye JE, Butler DJ, Franich RD, Harty PD, Oliver CP, Ramanathan G, Webb DV, Wright T. Direct MC conversion of absorbed dose to graphite to absorbed dose to water for 60Co radiation. RADIATION PROTECTION DOSIMETRY 2013; 155:100-109. [PMID: 23152147 DOI: 10.1093/rpd/ncs276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The ARPANSA calibration service for (60)Co gamma rays is based on a primary standard graphite calorimeter that measures absorbed dose to graphite. Measurements with the calorimeter are converted to the absorbed dose to water using the calculation of the ratio of the absorbed dose in the calorimeter to the absorbed dose in a water phantom. ARPANSA has recently changed the basis of this calculation from a photon fluence scaling method to a direct Monte Carlo (MC) calculation. The MC conversion uses an EGSnrc model of the cobalt source that has been validated against water tank and graphite phantom measurements, a step that is required to quantify uncertainties in the underlying interaction coefficients in the MC code. A comparison with the Bureau International des Poids et Mesures (BIPM) as part of the key comparison BIPM.RI(I)-K4 showed an agreement of 0.9973 (53).
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Ramanathan G, Periyasamy S, Lakkakula BV. NOS3 tagSNPs does not modify the chronic kidney disease progression in autosomal dominant polycystic kidney disease. Nephrology (Carlton) 2014; 19:537-541. [PMID: 24824375 DOI: 10.1111/nep.12278] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2014] [Indexed: 11/30/2022]
Abstract
AIM Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary and progressive renal disorder. It is also recognised as the most frequent genetic cause of chronic kidney diseases (CKD). In the present study, four tagging SNPs and two more well studied polymorphisms (Intron 4 VNTR and Glu298Asp) the NOS3 gene were investigated to unravel the potential modifier effect of NOS3 gene on the progression of CKD in ADPKD. METHODS A total of 102 ADPKD patients and 106 controls were selected for the study. The tagSNPs and Glu298Asp polymorphisms were genotyped using FRET-based KASPar method and intron-4 VNTR by polymerase chain reaction electrophoresis. The genotypes and haplotypes in the controls and ADPKD subjects were analysed by χ(2) tests and haploview software. Mantel-Haenszel stratified and univariate analyses were performed to estimate the influence of different genotypes between different CKD stages and hypertension. RESULTS The tagSNPs of NOS3 genotypes and haplotypes did not exhibit any significant differences between controls and ADPKD patients. The significant linkage disequilibrium was observed between the rs3918184 and rs2853796 by forming LD block. In univariate analysis, the age and family history of Diabetes mellitus (DM) showed significant association with advancement of CKD, but not with the eNOS polymorphisms. CONCLUSIONS Our data suggests that there is no evidence for the involvement of NOS3 tag SNPs in the progression to CKD in ADPKD patients. A systematic study using well validated functional SNPs is necessary to clarify the role of the NOS3 gene in the development of CKD in ADPKD.
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Babu A, Devi Rajeswari V, Ganesh V, Das S, Dhanasekaran S, Usha Rani G, Ramanathan G. Gut Microbiome and Polycystic Ovary Syndrome: Interplay of Associated Microbial-Metabolite Pathways and Therapeutic Strategies. Reprod Sci 2024; 31:1508-1520. [PMID: 38228976 DOI: 10.1007/s43032-023-01450-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/28/2023] [Indexed: 01/18/2024]
Abstract
Polycystic ovary syndrome (PCOS) is a multifaceted disease with an intricate etiology affecting reproductive-aged women. Despite attempts to unravel the pathophysiology, the molecular mechanism of PCOS remains unknown. There are no effective or suitable therapeutic strategies available to ameliorate PCOS; however, the symptoms can be managed. In recent years, a strong association has been found between the gut microbiome and PCOS, leading to the formulation of novel ideas on the genesis and pathological processes of PCOS. Further, gut microbiome dysbiosis involving microbial metabolites may trigger PCOS symptoms via many mechanistic pathways including those associated with carbohydrates, short-chain fatty acids, lipopolysaccharides, bile acids, and gut-brain axis. We present the mechanistic pathways of PCOS-related microbial metabolites and therapeutic opportunities available to treat PCOS, such as prebiotics, probiotics, and fecal microbiota therapy. In addition, the current review highlights the emerging treatment strategies available to alleviate the symptoms of PCOS.
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Review |
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Mallina H, Elumalai R, F D Paul S, George Priya Doss C, Udhaya Kumar S, Ramanathan G. Computational validation of ABCB1 gene polymorphism and its effect on tacrolimus dose concentration/levels in renal transplant individuals of South India. Comput Biol Med 2021; 139:104971. [PMID: 34735949 DOI: 10.1016/j.compbiomed.2021.104971] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/17/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Patients with end-stage renal failure require hemodialysis and peritoneal dialysis; however, kidney transplantation is considered a better treatment option for renal failure patients, improving their quality of life and longevity. Among several potent immunosuppressive agents, tacrolimus (TAC) has shown progressive improvement in the graft survival rates after renal transplantation. Fifty kidney transplant patients undergoing TAC immunosuppressive treatment were included. The human genomic DNA was isolated using the phenol-chloroform extraction procedure. CYP3A5*6, CYP3A5*2, and ABCB1 exon 21 G2677 T/A polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. Fisher's exact test and Chi-square analysis were performed to analyze the data, where p < 0.05 was considered statistically significant. In addition, we implemented bioinformatics studies on ABCB1 protein to determine the mutation's effect sequentially and structurally. Among the genotyped single nucleotide polymorphisms (SNPs), SNPs of CYP3A5*2 and CYP3A5*6 did not vary in the studied population. The concentration/dose (C/D) ratio of TT genotype of the ABCB1 gene was higher (95% CI: 177.38-269.46) when compared to TA and AA. However, there were no substantial differences between the ABCB1 genotypes and TAC C/D ratio (p = 0.953). The TAC dose mg/kg/day (p = 0.002) and C/D ratio (p = 0.004) exhibited a statistically significant difference. However, no significant difference was found with respect to the ABCB1 gene between the non-toxicity and toxicity groups. Mutation and residue interaction analysis results showed that the S893T mutation destabilizes the ABCB1 protein, thus reducing the protein's flexibility. The present study demonstrated a substantial relationship between the TAC dose and C/D ratio, including the non-toxicity and toxicity groups. However, no possible correlation was observed between the ABCB1 gene polymorphism and renal transplant.
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Kumar SU, Rajan B, Kumar DT, Cathryn RH, Das S, Zayed H, Emmanuel Jebaraj Walter C, Ramanathan G, Priya Doss C G. Comparison of potential inhibitors and targeting fat mass and obesity-associated protein causing diabesity through docking and molecular dynamics strategies. J Cell Biochem 2021; 122:1625-1638. [PMID: 34289159 DOI: 10.1002/jcb.30109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 12/15/2022]
Abstract
Genome-wide association studies (GWAS) have identified an association between polymorphisms in the FTO gene and obesity. The FTO: rs9939609, an intronic variant, is considered a risk allele for developing diabesity in homozygous and heterozygous forms. This study aimed to investigate the molecular structure of the available inhibitors specific to the FTO mutations along with the rs9939609 variant. We identified the best-suited inhibitor molecules for each mutant type containing the rs9939609 risk allele. Missense mutations unique to obesity and containing the risk allele of rs9939609 were retrieved from dbSNP for this study. Further stability testing for the mutations were carried out using DynaMut and iStable tools. Three mutations (G187A, M223V, and I492V) were highly destabilizing the FTO structure. These three mutants and native FTO were docked with each of the nine-inhibitor molecules collected from literature studies with the help of PyRx and AutoDock. Further structural behavior of the mutants and native FTO were identified with molecular dynamics simulations and MM-PBSA analyses, along with the 19complex inhibitor compound. We found the compound 19complex exhibited better binding interactions and is the top candidate inhibitor for the M223V and I492V mutants. This study provided insights into the structural changes caused due to mutations in FTO, and the binding mechanism of the inhibitor molecules. It could aid in developing antiobesity drugs for treating patients with mutations and risk alleles predisposing to obesity.
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Yusuf JH, Kaliyaperumal D, Jayaraman M, Ramanathan G, Devaraju P. Genetic selection pressure in TLR9 gene may enforce risk for SLE in Indian Tamils. Lupus 2016; 26:307-310. [PMID: 27432810 DOI: 10.1177/0961203316659151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objectives Lupus is a classical systemic autoimmune disease with genetics as one of the well known causative factors for the disease pathogenesis. Toll-like receptors are the major pattern recognition receptors associated with innate immunity and also act as an interface with the adaptive immunity. Genetic polymorphisms in genes encoding TLRs were implicated in the development of infections, malignancies and autoimmune diseases. TLR9 is a member of TLR family, and recognizes the CpG DNA motifs of pathogens. Though the incidence rate of lupus in Asians was reported to be low (30 - 50/100,000 population), poor disease prognosis due to higher incidence of renal complications and aggressive disease worsens the scenario. The ability of TLR9 to detect and elicit an immune response against double-stranded DNA makes TLR9 a relevant factor to be tested for its association with the clinical and serological phenotypes of lupus. However, lack of relevant genetic data on normative frequencies of the TLR9 (rs187084) polymorphism may serve as a constraint to derive the sample size to conduct case control association studies. Hence this study was conducted to establish the normative frequency of TLR9 (rs187084) polymorphism in Indian Tamils. Materials and methods The TLR9 (rs187084) polymorphism was screened in South Indian Tamils ( n = 208) by PCR-RFLP. Results and discussion We observed a higher occurrence of the mutant allele (65%) in South Indian Tamils. No gender disparity with respect to the mutant allele frequency was observed. The higher incidence of mutant allele in both genders suggests that this population had undergone a genetic selection pressure as an evolutionary genetic measure to withstand the prevailing endemic infections like TB and malaria. Though the enhanced expression of TLR9 was protective against infections, it may also influence the development of autoimmune diseases. Conclusion The higher incidence of theTLR9 (rs187084) over-expression mutation in Indian Tamils is suggestive of a genetic adaptation or selection pressure to withstand the prevailing endemic infectious and parasitic diseases. However, this genetic adaptation poses a greater risk to develop autoimmune diseases like SLE etc through complex gene environment interactions. The normative frequency of the TLR9 (rs187084) polymorphism established in our population could now be used to define the sample size for future case control studies.
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Das S, Babu A, Medha T, Ramanathan G, Mukherjee AG, Wanjari UR, Murali R, Kannampuzha S, Gopalakrishnan AV, Renu K, Sinha D, George Priya Doss C. Molecular mechanisms augmenting resistance to current therapies in clinics among cervical cancer patients. Med Oncol 2023; 40:149. [PMID: 37060468 PMCID: PMC10105157 DOI: 10.1007/s12032-023-01997-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/10/2023] [Indexed: 04/16/2023]
Abstract
Cervical cancer (CC) is the fourth leading cause of cancer death (~ 324,000 deaths annually) among women internationally, with 85% of these deaths reported in developing regions, particularly sub-Saharan Africa and Southeast Asia. Human papillomavirus (HPV) is considered the major driver of CC, and with the availability of the prophylactic vaccine, HPV-associated CC is expected to be eliminated soon. However, female patients with advanced-stage cervical cancer demonstrated a high recurrence rate (50-70%) within two years of completing radiochemotherapy. Currently, 90% of failures in chemotherapy are during the invasion and metastasis of cancers related to drug resistance. Although molecular target therapies have shown promising results in the lab, they have had little success in patients due to the tumor heterogeneity fueling resistance to these therapies and bypass the targeted signaling pathway. The last two decades have seen the emergence of immunotherapy, especially immune checkpoint blockade (ICB) therapies, as an effective treatment against metastatic tumors. Unfortunately, only a small subgroup of patients (< 20%) have benefited from this approach, reflecting disease heterogeneity and manifestation with primary or acquired resistance over time. Thus, understanding the mechanisms driving drug resistance in CC could significantly improve the quality of medical care for cancer patients and steer them to accurate, individualized treatment. The rise of artificial intelligence and machine learning has also been a pivotal factor in cancer drug discovery. With the advancement in such technology, cervical cancer screening and diagnosis are expected to become easier. This review will systematically discuss the different tumor-intrinsic and extrinsic mechanisms CC cells to adapt to resist current treatments and scheme novel strategies to overcome cancer drug resistance.
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Review |
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Shimizu M, Morishita Y, Kato M, Tanaka T, Kurosawa T, Takata N, Saito N, Ramanathan G, Harty PD, Oliver C, Wright T, Butler DJ. Comparison of the NMIJ and the ARPANSA standards for absorbed dose to water in high-energy photon beams. RADIATION PROTECTION DOSIMETRY 2015; 164:181-186. [PMID: 25209996 DOI: 10.1093/rpd/ncu272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/30/2014] [Indexed: 06/03/2023]
Abstract
The authors report the results of an indirect comparison of the standards of absorbed dose to water in high-energy photon beams from a clinical linac and (60)Co radiation beam performed between the National Metrology Institute of Japan (NMIJ) and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Three ionisation chambers were calibrated by the NMIJ in April and June 2013 and by the ARPANSA in May 2013. The average ratios of the calibration coefficients for the three ionisation chambers obtained by the NMIJ to those obtained by the ARPANSA were 0.9994, 1.0040 and 1.0045 for 6-, 10- and 15-MV (18 MV at the ARPANSA) high-energy photon beams, respectively. The relative standard uncertainty of the value was 7.2 × 10(-3). The ratio for (60)Co radiation was 0.9986(66), which is consistent with the results published in the key comparison of BIPM.RI(I)-K4.
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Elumalai R, Periasamy S, Ramanathan G, Lakkakula BV. Role of endothelial nitric oxide synthase VNTR (intron 4 a/b) polymorphism on the progression of renal disease in autosomal dominant polycystic kidney disease. J Renal Inj Prev 2014; 3:69-73. [PMID: 25340172 PMCID: PMC4206055 DOI: 10.12861/jrip.2014.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 09/22/2013] [Accepted: 12/25/2013] [Indexed: 12/29/2022] Open
Abstract
Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder, and it is mainly associated with renal cyst formation. Several studies have also shown that these mutations regulate the physiology of epithelial tissues and determine renal cyst formation and growth in polycystic kidney disease (PKD). Nitric oxide (NO) is also considered to be an important factor involved in the deterioration of renal function.
Objectives: The aim of the current study is to determine the frequency of NOS3 27-bp VNTR in ADPKD patients and to investigate the role of NOS3 27-bp VNTR genotypes in the modification of progression of renal disease in ADPKD.Patients and Methods: The hypothesis was investigated by studying the South Indian population of 53 ADPKD patients and 94 unrelated healthy controls. The genotyping was performed by polymerase chain reaction and electrophoresis. Genotypes were compared between ADPKD and controls using the χ2-test. Univariate and multivariate logistic regression analyses were performed to assess the effect of genotypes and hypertension on the progress of chronic kidney disease (CKD). A stratified analysis was also performed to assess the evidence of the modification of hypertension-CKD relationship among VNTR genotypes.
Results: The NOS3 4a allele frequencies were 21.3% and 13.2% respectively for controls and ADPKD groups. The NOS3 VNTR genotypes and alleles were not associated with ADPKD. The univariate analysis showed that age, hypertension and NOS3 VNTR influenced the advancement of CKD.
Conclusion: The present study confirms the significant association between the 27-bp VNTR and CKD advancement among the ADPKD patients in the South Indian population.
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Ramanathan G, Rathan SV, Murali KR. Photocatalytic activity of biosynthesized CeO2 nano particles. SN APPLIED SCIENCES 2019. [DOI: 10.1007/s42452-018-0103-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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