Displaying publications 1 - 20 of 45 in total

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  1. Zihad SMNK, Bhowmick N, Uddin SJ, Sifat N, Rahman MS, Rouf R, et al.
    Front Pharmacol, 2018;9:1164.
    PMID: 30374304 DOI: 10.3389/fphar.2018.01164
    Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.
  2. Warrier S, Marimuthu R, Sekhar S, Bhuvanalakshmi G, Arfuso F, Das AK, et al.
    Int J Biochem Cell Biol, 2016 06;75:104-11.
    PMID: 27063405 DOI: 10.1016/j.biocel.2016.04.002
    The extracellular ligand, Wnt, and its receptors are involved in sign al transduction and play an important role in axis formation and neural development. In neurodegenerative disorders such as Alzheimer's disease (AD), a decrease of the intracellular Wnt effector, β-catenin, has been linked to amyloid-β-peptide-induced neurotoxicity. Despite this knowledge, targeting Wnt inhibitors as potential biomarkers has not been explored, and harnessing Wnt activators as therapeutic candidates remains largely not investigated. A wide acting family of Wnt mediators, secreted frizzled-related proteins (sFRPs), has not been probed so far as molecular indicators of disease occurrence and progression of Alzheimer's. Unlike the effect of the Dickkopf (DKK) family of Wnt antagonists on AD, the sFRP molecules have a more pleiotropic impact on the Wnt signaling cascade and probably have a far-reaching involvement in neurodegeneration. The role of sFRPs has been poorly described in AD, and in this review, we analyze the present status of the role of sFRPs on neurodegeneration, their likely involvement, and potential implications in treatment modalities of AD. This information would provide valuable clues for the development of potential therapeutic targets for aberrant neurodegenerative disorders.
  3. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Sep 22;131(12):121901.
    PMID: 37802954 DOI: 10.1103/PhysRevLett.131.121901
    The dependence of the ratio between the B_{s}^{0} and B^{+} hadron production fractions, f_{s}/f_{u}, on the transverse momentum (p_{T}) and rapidity of the B mesons is studied using the decay channels B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+}. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb^{-1}. The f_{s}/f_{u} ratio is observed to depend on the B p_{T} and to be consistent with becoming asymptotically constant at large p_{T}. No rapidity dependence is observed. The ratio of the B^{0} to B^{+} meson production fractions, f_{d}/f_{u}, is also measured, for the first time in proton-proton collisions, using the B^{0}→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of p_{T} and rapidity, as expected from isospin invariance.
  4. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Oct 13;131(15):151803.
    PMID: 37897747 DOI: 10.1103/PhysRevLett.131.151803
    We present an observation of photon-photon production of τ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404  μb^{-1} collected by the CMS experiment at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. The γγ→τ^{+}τ^{-} process is observed for τ^{+}τ^{-} events with a muon and three charged hadrons in the final state. The measured fiducial cross section is σ(γγ→τ^{+}τ^{-})=4.8±0.6(stat)±0.5(syst)  μb, where the second (third) term corresponds to the statistical (systematic) uncertainty in σ(γγ→τ^{+}τ^{-}) in agreement with leading-order QED predictions. Using σ(γγ→τ^{+}τ^{-}), we estimate a model-dependent value of the anomalous magnetic moment of the τ lepton of a_{τ}=0.001_{-0.089}^{+0.055}.
  5. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Jul 07;131(1):011803.
    PMID: 37478454 DOI: 10.1103/PhysRevLett.131.011803
    The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision dataset recorded at sqrt[s]=13  TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138  fb^{-1}. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV-25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective μμ Majorana neutrino mass of 10.8 GeV.
  6. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Aug 11;131(6):061801.
    PMID: 37625071 DOI: 10.1103/PhysRevLett.131.061801
    A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H→cc[over ¯], produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at sqrt[s]=13  TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138  fb^{-1}. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z→cc[over ¯] in VZ events, leading to its first observation at a hadron collider with a significance of 5.7 standard deviations. The observed (expected) upper limit on σ(VH)B(H→cc[over ¯]) is 0.94 (0.50_{-0.15}^{+0.22})pb at 95% confidence level (C.L.), corresponding to 14 (7.6_{-2.3}^{+3.4}) times the standard model prediction. For the Higgs-charm Yukawa coupling modifier, κ_{c}, the observed (expected) 95% C.L. interval is 1.1
  7. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Jul 28;131(4):041803.
    PMID: 37566864 DOI: 10.1103/PhysRevLett.131.041803
    A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb^{-1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, κ_{2V}, excluding κ_{2V}=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.
  8. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Jul 28;131(4):041801.
    PMID: 37566854 DOI: 10.1103/PhysRevLett.131.041801
    A search for the standard model (SM) Higgs boson (H) produced with transverse momentum (p_{T}) greater than 450 GeV and decaying to a charm quark-antiquark (cc[over ¯]) pair is presented. The search is performed using proton-proton collision data collected at sqrt[s]=13  TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138  fb^{-1}. Boosted H→cc[over ¯] decay products are reconstructed as a single large-radius jet and identified using a deep neural network charm tagging technique. The method is validated by measuring the Z→cc[over ¯] decay process, which is observed in association with jets at high p_{T} for the first time with a signal strength of 1.00_{-0.14}^{+0.17}(syst)±0.08(theo)±0.06(stat), defined as the ratio of the observed process rate to the SM expectation. The observed (expected) upper limit on σ(H)B(H→cc[over ¯]) is set at 47 (39) times the SM prediction at 95% confidence level.
  9. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Sep 08;131(10):101801.
    PMID: 37739361 DOI: 10.1103/PhysRevLett.131.101801
    We present the first direct search for exotic Higgs boson decays H→AA, A→γγ in events with two photonlike objects. The hypothetical particle A is a low-mass spin-0 particle decaying promptly to a merged diphoton reconstructed as a single photonlike object. We analyze the data collected by the CMS experiment at sqrt[s]=13  TeV corresponding to an integrated luminosity of 136  fb^{-1}. No excess above the estimated background is found. We set upper limits on the branching fraction B(H→AA→4γ) of (0.9-3.3)×10^{-3} at 95% confidence level for masses of A in the range 0.1-1.2 GeV.
  10. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Sep 01;131(9):091803.
    PMID: 37721845 DOI: 10.1103/PhysRevLett.131.091803
    The first observation of the production of W^{±}W^{±} bosons from double parton scattering processes using same-sign electron-muon and dimuon events in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of 138  fb^{-1} recorded at a center-of-mass energy of 13 TeV using the CMS detector at the CERN LHC. Multivariate discriminants are used to distinguish the signal process from the main backgrounds. A binned maximum likelihood fit is performed to extract the signal cross section. The measured cross section for production of same-sign W bosons decaying leptonically is 80.7±11.2(stat) _{-8.6}^{+9.5}(syst)±12.1(model)  fb, whereas the measured fiducial cross section is 6.28±0.81(stat)±0.69(syst)±0.37(model)  fb. The observed significance of the signal is 6.2 standard deviations above the background-only hypothesis.
  11. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Eur Phys J C Part Fields, 2023;83(10):933.
    PMID: 37855556 DOI: 10.1140/epjc/s10052-023-11952-7
    A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at s=13TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138fb-1. The 95% confidence level upper limit set on the branching fraction of the 125GeV Higgs boson to invisible particles, B(H→inv), is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous B(H→inv) searches carried out at s=7, 8, and 13TeV in complementary production modes. The combined upper limit at 95% confidence level on B(H→inv) is 0.15 (0.08 expected).
  12. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Phys Rev Lett, 2023 Dec 29;131(26):262301.
    PMID: 38215362 DOI: 10.1103/PhysRevLett.131.262301
    Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J/ψ photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (W_{γN}^{Pb}) over a wide range of 40
  13. Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, et al.
    Eur Phys J C Part Fields, 2023;83(10):963.
    PMID: 37906635 DOI: 10.1140/epjc/s10052-023-12050-4
    The mass of the top quark is measured in 36.3fb-1 of LHC proton-proton collision data collected with the CMS detector at s=13TeV. The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77±0.37GeV. This approach significantly improves the precision over previous measurements.
  14. Rengasamy M, Singh G, Fakharuzi NA, Siddikuzzaman, Balasubramanian S, Swamynathan P, et al.
    Stem Cell Res Ther, 2017 06 13;8(1):143.
    PMID: 28610623 DOI: 10.1186/s13287-017-0595-1
    BACKGROUND: Mesenchymal stromal cells (MSCs) from various tissues have shown moderate therapeutic efficacy in reversing liver fibrosis in preclinical models. Here, we compared the relative therapeutic potential of pooled, adult human bone marrow (BM)- and neonatal Wharton's jelly (WJ)-derived MSCs to treat CCl4-induced liver fibrosis in rats.

    METHODS: Sprague-Dawley rats were injected with CCl4 for 8 weeks to induce irreversible liver fibrosis. Ex-vivo expanded, pooled human MSCs obtained from BM and WJ were intravenously administered into rats with liver fibrosis at a dose of 10 × 106 cells/animal. Sham control and vehicle-treated animals served as negative and disease controls, respectively. The animals were sacrificed at 30 and 70 days after cell transplantation and hepatic-hydroxyproline content, histopathological, and immunohistochemical analyses were performed.

    RESULTS: BM-MSCs treatment showed a marked reduction in liver fibrosis as determined by Masson's trichrome and Sirius red staining as compared to those treated with the vehicle. Furthermore, hepatic-hydroxyproline content and percentage collagen proportionate area were found to be significantly lower in the BM-MSCs-treated group. In contrast, WJ-MSCs treatment showed less reduction of fibrosis at both time points. Immunohistochemical analysis of BM-MSCs-treated liver samples showed a reduction in α-SMA+ myofibroblasts and increased number of EpCAM+ hepatic progenitor cells, along with Ki-67+ and human matrix metalloprotease-1+ (MMP-1+) cells as compared to WJ-MSCs-treated rat livers.

    CONCLUSIONS: Our findings suggest that BM-MSCs are more effective than WJ-MSCs in treating liver fibrosis in a CCl4-induced model in rats. The superior therapeutic activity of BM-MSCs may be attributed to their expression of certain MMPs and angiogenic factors.

  15. Mamidi MK, Dutta S, Bhonde R, Das AK, Pal R
    Med Hypotheses, 2014 Dec;83(6):787-91.
    PMID: 25456787 DOI: 10.1016/j.mehy.2014.10.010
    Stem cell transplantation is a generic term covering different techniques. However there is argument over the pros and cons of autologous and allogeneic transplants of mesenchymal stem cells (MSCs) for regenerative therapy. Given that the MSCs have already been proven to be safe in patients, we hypothesize that allogeneic transplantation could be more effective and cost-effective as compared to autologous transplantation specifically in older subjects who are the likely victims of degenerative diseases. This analysis is based on the scientific logic that allogeneic stem cells extracted in large numbers from young and healthy donors could be physiologically, metabolically and genetically more stable. Therefore stem cells from young donors may be expected to exhibit higher vigor in secreting trophic factors leading to activation of host tissue-specific stem cells and also be more efficient in remodeling the micro-environmental niche of damaged tissue.
  16. Mamidi MK, Pal R, Dey S, Bin Abdullah BJ, Zakaria Z, Rao MS, et al.
    Cytotherapy, 2012 Sep;14(8):902-16.
    PMID: 22731756 DOI: 10.3109/14653249.2012.693156
    Critical limb ischemia (CLI) is a syndrome manifested by ischemic rest pain, non-healing ulcers and tissue loss. CLI patients are at very high risk of amputation and experience poor physical function, leading to severe morbidity and mortality. The fundamental goal for CLI treatment is to relieve ischemic rest pain, heal ulcers, prevent limb loss and improve the quality of life, thereby extending the survival of the patient. Surgical or endovascular revascularization aimed at increasing blood flow is currently available for limb salvage in CLI. However, up to 30% of CLI patients are not suitable for such interventions because of high operative risk or unfavorable vascular anatomy. Therefore exploring new and more effective strategies for revascularization of ischemic limbs is imperative for the establishment of a viable therapeutic alternative. With the emergence of new approaches, this review describes up-to-date progress and developments in cell-based therapy as a novel and promising alternative for CLI treatment. Preliminary clinical data have established the safety, feasibility and efficacy of stem cells, and numerous studies are underway to consolidate this evidence further. However, significant hurdles remain to be addressed before this research can be responsibly translated to the bedside. In particular, we need better understanding of the behavior of cells post-transplantation and to learn how to control their survival and migration proliferation/differentiation in the hostile pathologic environment. Future research should focus on methods of isolation, optimal dosage, appropriate cell type, route of administration, role of tissue-derived factors and supportive endogenous stimulation.
  17. Mamidi MK, Singh G, Husin JM, Nathan KG, Sasidharan G, Zakaria Z, et al.
    J Transl Med, 2012;10:229.
    PMID: 23171323 DOI: 10.1186/1479-5876-10-229
    Numerous preclinical and clinical studies have investigated the regenerative potential and the trophic support of mesenchymal stem cells (MSCs) following their injection into a target organ. Clinicians favor the use of smallest bore needles possible for delivering MSCs into vascular organs like heart, liver and spleen. There has been a concern that small needle bore sizes may be detrimental to the health of these cells and reduce the survival and plasticity of MSCs.
  18. Mamidi MK, Das AK, Zakaria Z, Bhonde R
    Osteoarthritis Cartilage, 2016 Aug;24(8):1307-16.
    PMID: 26973328 DOI: 10.1016/j.joca.2016.03.003
    Treatment for articular cartilage damage is quite challenging as it shows limited repair and regeneration following injury. Non-operative and classical surgical techniques are inefficient in restoring normal anatomy and function of cartilage in osteoarthritis (OA). Thus, investigating new and effective strategies for OA are necessary to establish feasible therapeutic solutions. The emergence of the new discipline of regenerative medicine, having cell-based therapy as its primary focus, may enable us to achieve repair and restore the damaged articular cartilage. This review describes progress and development of employing mesenchymal stromal cell (MSC)-based therapy as a promising alternative for OA treatment. The objective of this review is to first, discuss how in vitro MSC chondrogenic differentiation mimics in vivo embryonic cartilage development, secondly, to describe various chondrogenic differentiation strategies followed by pre-clinical and clinical studies demonstrating their feasibility and efficacy. However, several challenges need to be tackled before this research can be translated to the clinics. In particular, better understanding of the post-transplanted cell behaviour and learning to enhance their potency in the disease microenvironment is essential. Final objective is to underscore the importance of isolation, storage, cell shipment, route of administration, optimum dosage and control batch to batch variations to realise the full potential of MSCs in OA clinical trials.
  19. Mamidi MK, Pal R, Mori NA, Arumugam G, Thrichelvam ST, Noor PJ, et al.
    J Cell Biochem, 2011 May;112(5):1353-63.
    PMID: 21337383 DOI: 10.1002/jcb.23052
    Among the different parameters governing the successful derivation and expansion of human embryonic stem cells (hESC), feeder layers play the most important role. Human feeders in form of human mesenchymal stromal cells (hMSCs) and human foreskin fibroblasts (HFFs) lay the foundation for eradication of animal-derived hESC culture system. In this study we explored the potential of human foreskin derived mesenchymal like stromal cells (HF-MSCs) to support self renewal and pluripotency of hESC. The MSCs isolated from human foreskin were found to be resistant to standard concentrations and duration of mitomycin-C treatment. Growth pattern, gene profiling (Oct-4, Nanog, Sox-2, Rex-1), cytoskeletal protein expression (vimentin, nestin) and tri-lineage differentiation potential into adipocytes, chondrocytes and osteocytes confirmed their mesenchymal stromal cell status. Further, the HF-MSCs were positive for CD105, CD166, CD73, CD44, CD90, SSEA-4, and negative for CD34, CD45, HLA-DR cell-surface markers and were found to exhibit BM-MSC-like characteristics. hESC lines co-cultured with HF-MSC feeders showed expression of expected pluripotent transcription factors Oct-4, Nanog, Sox-2, GDF-3, Rex-1, STELLAR, ABCG2, Dppa5, hTERT; surface markers SSEA-4, TRA-1-81 and maintained their cytogenetic stability during long term passaging. These novel feeders also improved the formation of embryoid bodies (EBs) from hESC which produced cell types representing three germ layers. This culture system has the potential to aid the development of clinical-grade hESCs for regenerative medicine and drug screening. Further, we envisage foreskin can serve as a valuable source of alternative MSCs for specific therapeutic applications.
  20. Mamidi MK, Nathan KG, Singh G, Thrichelvam ST, Mohd Yusof NA, Fakharuzi NA, et al.
    J Cell Biochem, 2012 Oct;113(10):3153-64.
    PMID: 22615164 DOI: 10.1002/jcb.24193
    The clinical application of human bone marrow derived multipotent mesenchymal stromal cells (MSC) requires expansion, cryopreservation, and transportation from the laboratory to the site of cell implantation. The cryopreservation and thawing process of MSCs may have important effects on the viability, growth characteristics and functionality of these cells both in vitro and in vivo. More importantly, MSCs after two rounds of cryopreservation have not been as well characterized as fresh MSCs from the transplantation perspective. The objective of this study was to determine if the effect of successive cryopreservation of pooled MSCs during the exponential growth phase could impair their morphology, phenotype, gene expression, and differentiation capabilities. MSCs cryopreserved at passage 3 (cell bank) were thawed and expanded up to passage 4 and cryopreserved for the second time. These cells (passive) were then thawed and cultured up to passage 6, and, at each passage MSCs were characterized. As control, pooled passage 3 cells (active) after one round of cryopreservation were taken all the way to passage 6 without cryopreservation. We determined the growth rate of MSCs for both culture conditions in terms of population doubling number (PDN) and population doubling time (PDT). Gene expression profiles for pluripotency markers and tissue specific markers corresponding to neuroectoderm, mesoderm and endoderm lineages were also analyzed for active and passive cultures of MSC. The results show that in both culture conditions, MSCs exhibited similar growth properties, phenotypes and gene expression patterns as well as similar differentiation potential to osteo-, chondro-, and adipo-lineages in vitro. To conclude, it appears that successive or multiple rounds of cryopreservation of MSCs did not alter the fundamental characteristics of these cells and may be used for clinical therapy.
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