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Han Y, Goel P, Chen J, Perry S, Tran N, Nishimura S, Sanjani M, Chien C, Dickman D. Excess glutamate release triggers subunit-specific homeostatic receptor scaling. Cell Rep 2023; 42:112775. [PMID: 37436892 PMCID: PMC10529671 DOI: 10.1016/j.celrep.2023.112775] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/06/2023] [Accepted: 06/25/2023] [Indexed: 07/14/2023] Open
Abstract
Ionotropic glutamate receptors (GluRs) are targets for modulation in Hebbian and homeostatic synaptic plasticity and are remodeled by development, experience, and disease. We have probed the impact of synaptic glutamate levels on the two postsynaptic GluR subtypes at the Drosophila neuromuscular junction, GluRA and GluRB. We first demonstrate that GluRA and GluRB compete to establish postsynaptic receptive fields, and that proper GluR abundance and composition can be orchestrated in the absence of any synaptic glutamate release. However, excess glutamate adaptively tunes postsynaptic GluR abundance, echoing GluR scaling observed in mammalian systems. Furthermore, when GluRA vs. GluRB competition is eliminated, GluRB becomes insensitive to glutamate modulation. In contrast, GluRA is now homeostatically regulated by excess glutamate to maintain stable miniature activity, where Ca2+ permeability through GluRA receptors is required. Thus, excess glutamate, GluR competition, and Ca2+ signaling collaborate to selectively target GluR subtypes for homeostatic regulation at postsynaptic compartments.
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Affiliation(s)
- Yifu Han
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiawen Chen
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Nancy Tran
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Samantha Nishimura
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Manisha Sanjani
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Chun Chien
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA.
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2
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Perry S, Han Y, Qiu C, Chien C, Goel P, Nishimura S, Sajnani M, Schmid A, Sigrist SJ, Dickman D. A glutamate receptor C-tail recruits CaMKII to suppress retrograde homeostatic signaling. Nat Commun 2022; 13:7656. [PMID: 36496500 PMCID: PMC9741633 DOI: 10.1038/s41467-022-35417-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Presynaptic homeostatic plasticity (PHP) adaptively enhances neurotransmitter release following diminished postsynaptic glutamate receptor (GluR) functionality to maintain synaptic strength. While much is known about PHP expression mechanisms, postsynaptic induction remains enigmatic. For over 20 years, diminished postsynaptic Ca2+ influx was hypothesized to reduce CaMKII activity and enable retrograde PHP signaling at the Drosophila neuromuscular junction. Here, we have interrogated inductive signaling and find that active CaMKII colocalizes with and requires the GluRIIA receptor subunit. Next, we generated Ca2+-impermeable GluRs to reveal that both CaMKII activity and PHP induction are Ca2+-insensitive. Rather, a GluRIIA C-tail domain is necessary and sufficient to recruit active CaMKII. Finally, chimeric receptors demonstrate that the GluRIIA tail constitutively occludes retrograde homeostatic signaling by stabilizing active CaMKII. Thus, the physical loss of the GluRIIA tail is sensed, rather than reduced Ca2+, to enable retrograde PHP signaling, highlighting a unique, Ca2+-independent control mechanism for CaMKII in gating homeostatic plasticity.
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Affiliation(s)
- Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Yifu Han
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Chengjie Qiu
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Chun Chien
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Samantha Nishimura
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Manisha Sajnani
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Andreas Schmid
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195, Berlin, Germany
- Faculty of Life Sciences, Albstadt-Sigmaringen University, Sigmaringen, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA.
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3
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Han Y, Chien C, Goel P, He K, Pinales C, Buser C, Dickman D. Botulinum neurotoxin accurately separates tonic vs. phasic transmission and reveals heterosynaptic plasticity rules in Drosophila. eLife 2022; 11:e77924. [PMID: 35993544 PMCID: PMC9439677 DOI: 10.7554/elife.77924] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/20/2022] [Indexed: 11/13/2022] Open
Abstract
In developing and mature nervous systems, diverse neuronal subtypes innervate common targets to establish, maintain, and modify neural circuit function. A major challenge towards understanding the structural and functional architecture of neural circuits is to separate these inputs and determine their intrinsic and heterosynaptic relationships. The Drosophila larval neuromuscular junction is a powerful model system to study these questions, where two glutamatergic motor neurons, the strong phasic-like Is and weak tonic-like Ib, co-innervate individual muscle targets to coordinate locomotor behavior. However, complete neurotransmission from each input has never been electrophysiologically separated. We have employed a botulinum neurotoxin, BoNT-C, that eliminates both spontaneous and evoked neurotransmission without perturbing synaptic growth or structure, enabling the first approach that accurately isolates input-specific neurotransmission. Selective expression of BoNT-C in Is or Ib motor neurons disambiguates the functional properties of each input. Importantly, the blended values of Is+Ib neurotransmission can be fully recapitulated by isolated physiology from each input. Finally, selective silencing by BoNT-C does not induce heterosynaptic structural or functional plasticity at the convergent input. Thus, BoNT-C establishes the first approach to accurately separate neurotransmission between tonic vs. phasic neurons and defines heterosynaptic plasticity rules in a powerful model glutamatergic circuit.
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Affiliation(s)
- Yifu Han
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Chun Chien
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Pragya Goel
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Kaikai He
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | | | | | - Dion Dickman
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
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Chan EF, Cockman MD, Goel P, Newman PS, Hipp JA. Characterization of the mid-coronal plane method for measurement of radiographic change in knee joint space width across different levels of image parallax. Osteoarthritis Cartilage 2021; 29:1306-1313. [PMID: 34171474 DOI: 10.1016/j.joca.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/13/2021] [Accepted: 06/13/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Radiographic measurement of the change in knee joint space width (ΔJSW) is often affected by image parallax, which causes an apparent exaggeration of JSW due to projectional differences. This issue with parallax (quantified by intermargin distance) can in part be addressed with a novel mid-coronal plane (MCP) measurement method. The objectives of the study were to determine 1) accuracy and 2) reproducibility of the MCP method, and 3) compare the MCP method to that used in the Osteoarthritis Initiative (OAI) for different categories of parallax. METHODS Posteroanterior radiographs (n = 70) with known JSW were digitally reconstructed from CT images of cadaver knees and used to determine the accuracy of ΔJSW using the MCP method for parallax categories of None, Mild/Moderate, and Severe. Reproducibility was determined from pairs of clinical radiographs selected from the OAI (n = 170). The MCP method was also compared to the OAI methodology. Both reproducibility and agreement were characterized by Bland-Altman analysis and intraclass correlation coefficients (ICC). RESULTS The MCP method was accurate to 0.11 mm in cases with no parallax, and 0.18 mm across all categories of parallax for medial and lateral compartments. Reproducibility of the MCP method was graded "excellent" (ICC 0.98, 95% CI [0.98, 0.99]). The MCP results agreed very well with the OAI (ICC 0.92, 95% CI [0.89, 0.94]), with mean absolute differences between methods increasing with increasing parallax. CONCLUSION The MCP method is an accurate, reproducible alternative to the OAI method for multi-center clinical trials where subject and X-ray beam positioning may be variable.
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Affiliation(s)
- E F Chan
- Medical Metrics, Inc., 2121 Sage Road, Suite 300, Houston, TX, 77056, USA.
| | - M D Cockman
- Medical Metrics, Inc., 2121 Sage Road, Suite 300, Houston, TX, 77056, USA.
| | - P Goel
- Medical Metrics, Inc., 2121 Sage Road, Suite 300, Houston, TX, 77056, USA.
| | - P S Newman
- Medical Metrics, Inc., 2121 Sage Road, Suite 300, Houston, TX, 77056, USA.
| | - J A Hipp
- Medical Metrics, Inc., 2121 Sage Road, Suite 300, Houston, TX, 77056, USA.
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Abstract
Dopamine is a prototypical neuromodulator that controls circuit function through G protein-coupled receptor signalling. Neuromodulators are volume transmitters, with release followed by diffusion for widespread receptor activation on many target cells. Yet, we are only beginning to understand the specific organization of dopamine transmission in space and time. Although some roles of dopamine are mediated by slow and diffuse signalling, recent studies suggest that certain dopamine functions necessitate spatiotemporal precision. Here, we review the literature describing dopamine signalling in the striatum, including its release mechanisms and receptor organization. We then propose the domain-overlap model, in which release and receptors are arranged relative to one another in micrometre-scale structures. This architecture is different from both point-to-point synaptic transmission and the widespread organization that is often proposed for neuromodulation. It enables the activation of receptor subsets that are within micrometre-scale domains of release sites during baseline activity and broader receptor activation with domain overlap when firing is synchronized across dopamine neuron populations. This signalling structure, together with the properties of dopamine release, may explain how switches in firing modes support broad and dynamic roles for dopamine and may lead to distinct pathway modulation.
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Affiliation(s)
- Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pragya Goel
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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6
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Goel P, Dickman D. Synaptic homeostats: latent plasticity revealed at the Drosophila neuromuscular junction. Cell Mol Life Sci 2021; 78:3159-3179. [PMID: 33449150 PMCID: PMC8044042 DOI: 10.1007/s00018-020-03732-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/19/2020] [Accepted: 12/04/2020] [Indexed: 12/11/2022]
Abstract
Homeostatic signaling systems are fundamental forms of biological regulation that maintain stable functionality in a changing environment. In the nervous system, synapses are crucial substrates for homeostatic modulation, serving to establish, maintain, and modify the balance of excitation and inhibition. Synapses must be sufficiently flexible to enable the plasticity required for learning and memory but also endowed with the stability to last a lifetime. In response to the processes of development, growth, remodeling, aging, and disease that challenge synapses, latent forms of adaptive plasticity become activated to maintain synaptic stability. In recent years, new insights into the homeostatic control of synaptic function have been achieved using the powerful Drosophila neuromuscular junction (NMJ). This review will focus on work over the past 10 years that has illuminated the cellular and molecular mechanisms of five homeostats that operate at the fly NMJ. These homeostats adapt to loss of postsynaptic neurotransmitter receptor functionality, glutamate imbalance, axonal injury, as well as aberrant synaptic growth and target innervation. These diverse homeostats work independently yet can be simultaneously expressed to balance neurotransmission. Growing evidence from this model glutamatergic synapse suggests these ancient homeostatic signaling systems emerged early in evolution and are fundamental forms of plasticity that also function to stabilize mammalian cholinergic NMJs and glutamatergic central synapses.
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Affiliation(s)
- Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA.
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Ramesh N, Escher MJF, Mampell MM, Böhme MA, Götz TWB, Goel P, Matkovic T, Petzoldt AG, Dickman D, Sigrist SJ. Antagonistic interactions between two Neuroligins coordinate pre- and postsynaptic assembly. Curr Biol 2021; 31:1711-1725.e5. [PMID: 33651992 DOI: 10.1016/j.cub.2021.01.093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 11/18/2020] [Accepted: 01/26/2021] [Indexed: 12/17/2022]
Abstract
As a result of developmental synapse formation, the presynaptic neurotransmitter release machinery becomes accurately matched with postsynaptic neurotransmitter receptors. Trans-synaptic signaling is executed through cell adhesion proteins such as Neurexin::Neuroligin pairs but also through diffusible and cytoplasmic signals. How exactly pre-post coordination is ensured in vivo remains largely enigmatic. Here, we identified a "molecular choreography" coordinating pre- with postsynaptic assembly during the developmental formation of Drosophila neuromuscular synapses. Two presynaptic Neurexin-binding scaffold proteins, Syd-1 and Spinophilin (Spn), spatio-temporally coordinated pre-post assembly in conjunction with two postsynaptically operating, antagonistic Neuroligin species: Nlg1 and Nlg2. The Spn/Nlg2 module promoted active zone (AZ) maturation by driving the accumulation of AZ scaffold proteins critical for synaptic vesicle release. Simultaneously, these regulators restricted postsynaptic glutamate receptor incorporation. Both functions of the Spn/Nlg2 module were directly antagonized by Syd-1/Nlg1. Nlg1 and Nlg2 also had divergent effects on Nrx-1 in vivo motility. Concerning diffusible signals, Spn and Syd-1 antagonistically controlled the levels of Munc13-family protein Unc13B at nascent AZs, whose release function facilitated glutamate receptor incorporation at assembling postsynaptic specializations. As a result, we here provide direct in vivo evidence illustrating how a highly regulative and interleaved communication between cell adhesion protein signaling complexes and diffusible signals allows for a precise coordination of pre- with postsynaptic assembly. It will be interesting to analyze whether this logic also transfers to plasticity processes.
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Affiliation(s)
- Niraja Ramesh
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Marc J F Escher
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Malou M Mampell
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Mathias A Böhme
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany; Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Torsten W B Götz
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Tanja Matkovic
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Astrid G Petzoldt
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Stephan J Sigrist
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany.
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Goel P, Singh M, Borle A, Garg S. Health preparedness plan to prevent dengue epidemic in an urban area of Delhi. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Khandelwal S, Goel P, Chaudhary D, Sancheti S, Goel A, Dora T, Sharma R. 30P Male breast cancer: A rural based peripheral cancer center experience. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.10.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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10
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Shyam S, Goel P, Kumar D, Malpotra S, Singh MK, Lathwal SS, Chand S, Palta P. Effect of Dickkopf-1 and colony stimulating factor-2 on the developmental competence, quality, gene expression and live birth rate of buffalo (Bubalus bubalis) embryos produced by hand-made cloning. Theriogenology 2020; 157:254-262. [PMID: 32823021 DOI: 10.1016/j.theriogenology.2020.07.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/07/2020] [Accepted: 07/25/2020] [Indexed: 01/23/2023]
Abstract
A functional canonical WNT signaling pathway exists in preimplantation embryos and inhibits embryonic development. Recent studies suggest that this pathway is over-expressed in nuclear transferred (NT), compared to IVF embryos. The present study investigated the effects of Dickkopf-1 (DKK1), an inhibitor of canonical WNT signaling pathway and colony stimulating factor-2 (CSF2), an embryokine, on the developmental competence, quality, gene expression and live birth rate of NT buffalo embryos produced by Hand-made cloning (HMC). Following supplementation of the in vitro culture medium on day 5 with DKK1 (100 ng/mL), CSF2 (10 ng/mL), DKK1+CSF2 or no supplementation (control), the blastocyst rate was higher (P < 0.05) with DKK1 and DKK1+CSF2 (42.6 ± 1.4% and 46.6 ± 0.9%, respectively) than with CSF2 or controls (40.6 ± 1.3% and 39.0 ± 1.3%, respectively). The apoptotic index of the blastocysts was lower (P < 0.05) for DKK1, CSF2 and DKK1+CSF2 groups (3.44 ± 0.14, 3.39 ± 0.11 and 3.11 ± 0.22, respectively) compared to controls (6.64 ± 0.25), and was similar to that of the IVF blastocysts (3.67 ± 0.18). Although the total cell number was similar for the DKK1, CSF2, DKK1+CSF2 and control groups (200.4 ± 3.05, 196.4 ± 3.73, 204.7 ± 3.71 and 205 ± 4.03, respectively), the inner cell mass:trophectoderm cell number ratio of DKK1, CSF2 and DKK1+CSF2 groups (0.21 ± 0.01, 0.17 ± 0.01 and 0.22 ± 0.02, respectively) was higher (P < 0.05) than controls (0.13 ± 0.01) and was similar to that of IVF blastocysts (0.19 ± 0.01). Treatment with DKK1 or CSF2 or both increased (P < 0.05) the expression level of OCT4, NANOG,SOX2, GATA6, BCL2, PTEN, P53, FGF4, GLUT1 and IFN-τ, and decreased that of C-MYC, CDX2, CASPASE, DNMT3a, TCF7 and LEF1 in blastocysts, compared to controls. Transfer of DKK1-treated embryos to 13 recipients resulted in 4 pregnancies (30.8%; 2 live births, one abortion and one currently at 9 months of pregnancy) whereas, transfer of DKK1+CSF2-treated embryos to 16 recipients, resulted in 4 pregnancies (25.0%), all of which resulted in live births. No pregnancy was obtained after transfer of control and CSF-treated embryos to 12 and 16 recipients, respectively. These results suggest that DKK1 treatment of NT embryos increases the blastocyst, conception and live birth rate, and improves their quality whereas, CSF2 treatment, does not affect the blastocyst, conception and live birth rate despite improvement in embryo quality.
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Affiliation(s)
- S Shyam
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - P Goel
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - D Kumar
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - S Malpotra
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - M K Singh
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - S S Lathwal
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - S Chand
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - P Palta
- ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India.
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11
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Goel P, Nishimura S, Chetlapalli K, Li X, Chen C, Dickman D. Distinct Target-Specific Mechanisms Homeostatically Stabilize Transmission at Pre- and Post-synaptic Compartments. Front Cell Neurosci 2020; 14:196. [PMID: 32676010 PMCID: PMC7333441 DOI: 10.3389/fncel.2020.00196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/05/2020] [Indexed: 12/28/2022] Open
Abstract
Neurons must establish and stabilize connections made with diverse targets, each with distinct demands and functional characteristics. At Drosophila neuromuscular junctions (NMJs), synaptic strength remains stable in a manipulation that simultaneously induces hypo-innervation on one target and hyper-innervation on the other. However, the expression mechanisms that achieve this exquisite target-specific homeostatic control remain enigmatic. Here, we identify the distinct target-specific homeostatic expression mechanisms. On the hypo-innervated target, an increase in postsynaptic glutamate receptor (GluR) abundance is sufficient to compensate for reduced innervation, without any apparent presynaptic adaptations. In contrast, a target-specific reduction in presynaptic neurotransmitter release probability is reflected by a decrease in active zone components restricted to terminals of hyper-innervated targets. Finally, loss of postsynaptic GluRs on one target induces a compartmentalized, homeostatic enhancement of presynaptic neurotransmitter release called presynaptic homeostatic potentiation (PHP) that can be precisely balanced with the adaptations required for both hypo- and hyper-innervation to maintain stable synaptic strength. Thus, distinct anterograde and retrograde signaling systems operate at pre- and post-synaptic compartments to enable target-specific, homeostatic control of neurotransmission.
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12
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Perry S, Goel P, Tran NL, Pinales C, Buser C, Miller DL, Ganetzky B, Dickman D. Developmental arrest of Drosophila larvae elicits presynaptic depression and enables prolonged studies of neurodegeneration. Development 2020; 147:dev.186312. [PMID: 32345746 DOI: 10.1242/dev.186312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/18/2020] [Indexed: 12/18/2022]
Abstract
Synapses exhibit an astonishing degree of adaptive plasticity in healthy and disease states. We have investigated whether synapses also adjust to life stages imposed by novel developmental programs for which they were never molded by evolution. Under conditions in which Drosophila larvae are terminally arrested, we have characterized synaptic growth, structure and function at the neuromuscular junction (NMJ). Although wild-type larvae transition to pupae after 5 days, arrested third instar (ATI) larvae persist for 35 days, during which time NMJs exhibit extensive overgrowth in muscle size, presynaptic release sites and postsynaptic glutamate receptors. Remarkably, despite this exuberant growth, stable neurotransmission is maintained throughout the ATI lifespan through a potent homeostatic reduction in presynaptic neurotransmitter release. Arrest of the larval stage in stathmin mutants also reveals a degree of progressive instability and neurodegeneration that was not apparent during the typical larval period. Hence, an adaptive form of presynaptic depression stabilizes neurotransmission during an extended developmental period of unconstrained synaptic growth. More generally, the ATI manipulation provides a powerful system for studying neurodegeneration and plasticity across prolonged developmental timescales.
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Affiliation(s)
- Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Nancy L Tran
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | | | | | - Daniel L Miller
- Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA.,National Institute of Neurological Disease and Stroke, NIH, Bethesda, MD 20824, USA
| | - Barry Ganetzky
- Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
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13
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Li X, Goel P, Wondolowski J, Paluch J, Dickman D. A Glutamate Homeostat Controls the Presynaptic Inhibition of Neurotransmitter Release. Cell Rep 2019; 23:1716-1727. [PMID: 29742428 PMCID: PMC5973541 DOI: 10.1016/j.celrep.2018.03.130] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/24/2018] [Accepted: 03/28/2018] [Indexed: 02/07/2023] Open
Abstract
We have interrogated the synaptic dialog that enables the bi-directional, homeostatic control of pre-synaptic efficacy at the glutamatergic Drosophila neuromuscular junction (NMJ). We find that homeo-static depression and potentiation use disparate genetic, induction, and expression mechanisms. Specifically, homeostatic potentiation is achieved through reduced CaMKII activity postsynaptically and increased abundance of active zone material presynaptically at one of the two neuronal subtypes innervating the NMJ, while homeostatic depression occurs without alterations in CaMKII activity and is expressed at both neuronal subtypes. Furthermore, homeostatic depression is only induced through excess presynaptic glutamate release and operates with disregard to the postsynaptic response. We propose that two independent homeostats modulate presynaptic efficacy at the Drosophila NMJ: one is an intercellular signaling system that potentiates synaptic strength following diminished postsynaptic excitability, while the other adaptively modulates presynaptic glutamate release through an autocrine mechanism without feedback from the postsynaptic compartment.
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Affiliation(s)
- Xiling Li
- Department of Neurobiology, University of Southern California, Los Angeles, CA; USC Neuroscience Graduate Program, University of Southern California, Los Angeles, CA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA; USC Graduate Program in Molecular and Computational Biology, University of Southern California, Los Angeles, CA
| | - Joyce Wondolowski
- Department of Neurobiology, University of Southern California, Los Angeles, CA
| | - Jeremy Paluch
- Department of Neurobiology, University of Southern California, Los Angeles, CA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA.
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14
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Kaushik A, Kapoor A, Dabadghao P, Khanna R, Kumar S, Garg N, Tewari S, Goel P. P1496Use of strain, strain rate, tissue velocity imaging and endothelial function for early detection of cardiovascular involvement in young diabetics. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Subtle structural and functional changes may precede the onset of overt global left ventricular dysfunction and obvious reduction of ejection fraction (EF), especially in young diabetics. Data pertaining to tissue velocity indices (TVI) and strain imaging to assess regional myocardial function and flow mediated vasodilatation is limited in young patients with diabetes.
Purpose
To evaluate conventional echocardiography parameters, tissue doppler indices, global and regional strain, carotid intimal medial thickness (CIMT), endothelial dependent (FMD) and independent function (NMD) of brachial artery in young patients (age <18 years) with type 1 diabetes and compare them with matched controls.
Methods
Conventional echocardiography parameters, tissue velocity indices (TVI) parameters along with strain (S), and strain rate (SR) in basal and mid left ventricular (LV) lateral wall, right ventricular (RV) lateral wall and septum were measured in 50 young diabetics (age 15.16±2.95 years, mean HBA1c 8.15±1.37 gm %) and 25 controls (age 15.60±2.51 years). Flow-mediated dilatation (FMD), nitrate mediated dilatation and carotid intimal media thickness (CIMT) were also estimated.
Results
Conventional echocardiography parameters were similar in patients and controls however deceleration time of the mitral inflow velocity (EDT) was significantly shorter in patients when compared with controls (149.06±31.66 vs. 184.56±19.27 ms, p<0.05). Lateral early diastolic myocardial velocity (LV-Em) was significantly lower (10.30±0.99 vs. 11.67±3.21, p<0.05) whereas lateral late diastolic myocardial velocity (LV-Am) was significantly higher than controls (11.73±1.44 vs. 8.82±1.69, p<0.05), thus a significantly lower ratio of early/late diastolic velocity at the basal segment of lateral LV (LV-Em/Am). Lower strain values at the basal lateral LV (21.39±4.12 vs. 23.78±2.02; p<0.05), mid lateral LV (21.43±4.27 vs. 23.17±1.92; p<0.05), basal septum (20.59±5.28 vs. 22.91±2.00; p<0.05), and mid septum (22.06±4.75 vs. 24.10±1.99; p<0.05) as compared to controls. SR at the basal and mid segments of the lateral LV wall and at the basal septum were also significantly lower in diabetic subjects. Strain rate (SR) in mid septal, basal and mid RV were lower than controls although not statistically significant. Patients also had significantly lower flow mediated dilatation (FMD) (8.36±4.27 vs. 10.57±4.12, p<0.05) implying endothelial dysfunction.
Strain rate in diabetic patient
Conclusion
Left ventricular strain indices are impaired in asymptomatic children and adolescents with type 1 DM despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population. In addition, evidence of endothelial dysfunction in the form of impaired flow mediated vasodilatation was observed in the diabetic children.
Acknowledgement/Funding
None
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Affiliation(s)
- A Kaushik
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - A Kapoor
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - P Dabadghao
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - R Khanna
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - S Kumar
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - N Garg
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - S Tewari
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
| | - P Goel
- Sanjay gandhi post graduate institute of Medical sciences, Lucknow, India
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15
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Kikuma K, Li X, Perry S, Li Q, Goel P, Chen C, Kim D, Stavropoulos N, Dickman D. Cul3 and insomniac are required for rapid ubiquitination of postsynaptic targets and retrograde homeostatic signaling. Nat Commun 2019; 10:2998. [PMID: 31278365 PMCID: PMC6611771 DOI: 10.1038/s41467-019-10992-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 06/14/2019] [Indexed: 01/05/2023] Open
Abstract
At the Drosophila neuromuscular junction, inhibition of postsynaptic glutamate receptors activates retrograde signaling that precisely increases presynaptic neurotransmitter release to restore baseline synaptic strength. However, the nature of the underlying postsynaptic induction process remains enigmatic. Here, we design a forward genetic screen to discover factors in the postsynaptic compartment necessary to generate retrograde homeostatic signaling. This approach identified insomniac (inc), a putative adaptor for the Cullin-3 (Cul3) ubiquitin ligase complex, which together with Cul3 is essential for normal sleep regulation. Interestingly, we find that Inc and Cul3 rapidly accumulate at postsynaptic compartments following acute receptor inhibition and are required for a local increase in mono-ubiquitination. Finally, we show that Peflin, a Ca2+-regulated Cul3 co-adaptor, is necessary for homeostatic communication, suggesting a relationship between Ca2+ signaling and control of Cul3/Inc activity in the postsynaptic compartment. Our study suggests that Cul3/Inc-dependent mono-ubiquitination, compartmentalized at postsynaptic densities, gates retrograde signaling and provides an intriguing molecular link between the control of sleep and homeostatic plasticity at synapses. The authors use a forward genetic screen to discover postsynaptic factors required for homeostatic synaptic plasticity at the Drosophila neuromuscular junction. They identify insomniac and the ubiquitin ligase Cul3, genes involved in sleep regulation, to be necessary for retrograde homeostatic signalling at this synapse.
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Affiliation(s)
- Koto Kikuma
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Xiling Li
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Qiuling Li
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, 10016, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Catherine Chen
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Daniel Kim
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Nicholas Stavropoulos
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, 10016, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA.
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16
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Goel P, Dufour Bergeron D, Böhme MA, Nunnelly L, Lehmann M, Buser C, Walter AM, Sigrist SJ, Dickman D. Homeostatic scaling of active zone scaffolds maintains global synaptic strength. J Cell Biol 2019; 218:1706-1724. [PMID: 30914419 PMCID: PMC6504899 DOI: 10.1083/jcb.201807165] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 12/14/2018] [Accepted: 03/06/2019] [Indexed: 12/23/2022] Open
Abstract
Synaptic terminals grow and retract throughout life, yet synaptic strength is maintained within stable physiological ranges. To study this process, we investigated Drosophila endophilin (endo) mutants. Although active zone (AZ) number is doubled in endo mutants, a compensatory reduction in their size homeostatically adjusts global neurotransmitter output to maintain synaptic strength. We find an inverse adaptation in rab3 mutants. Additional analyses using confocal, STED, and electron microscopy reveal a stoichiometric tuning of AZ scaffolds and nanoarchitecture. Axonal transport of synaptic cargo via the lysosomal kinesin adapter Arl8 regulates AZ abundance to modulate global synaptic output and sustain the homeostatic potentiation of neurotransmission. Finally, we find that this AZ scaling can interface with two independent homeostats, depression and potentiation, to remodel AZ structure and function, demonstrating a robust balancing of separate homeostatic adaptations. Thus, AZs are pliable substrates with elastic and modular nanostructures that can be dynamically sculpted to stabilize and tune both local and global synaptic strength.
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Affiliation(s)
- Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA
| | | | - Mathias A Böhme
- Neurocure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | - Luke Nunnelly
- Department of Neurobiology, University of Southern California, Los Angeles, CA
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | | | - Alexander M Walter
- Neurocure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | | | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA
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17
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Böhme MA, McCarthy AW, Grasskamp AT, Beuschel CB, Goel P, Jusyte M, Laber D, Huang S, Rey U, Petzoldt AG, Lehmann M, Göttfert F, Haghighi P, Hell SW, Owald D, Dickman D, Sigrist SJ, Walter AM. Rapid active zone remodeling consolidates presynaptic potentiation. Nat Commun 2019; 10:1085. [PMID: 30842428 PMCID: PMC6403334 DOI: 10.1038/s41467-019-08977-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 02/07/2019] [Indexed: 01/22/2023] Open
Abstract
Neuronal communication across synapses relies on neurotransmitter release from presynaptic active zones (AZs) followed by postsynaptic transmitter detection. Synaptic plasticity homeostatically maintains functionality during perturbations and enables memory formation. Postsynaptic plasticity targets neurotransmitter receptors, but presynaptic mechanisms regulating the neurotransmitter release apparatus remain largely enigmatic. By studying Drosophila neuromuscular junctions (NMJs) we show that AZs consist of nano-modular release sites and identify a molecular sequence that adds modules within minutes of inducing homeostatic plasticity. This requires cognate transport machinery and specific AZ-scaffolding proteins. Structural remodeling is not required for immediate potentiation of neurotransmitter release, but necessary to sustain potentiation over longer timescales. Finally, mutations in Unc13 disrupting homeostatic plasticity at the NMJ also impair short-term memory when central neurons are targeted, suggesting that both plasticity mechanisms utilize Unc13. Together, while immediate synaptic potentiation capitalizes on available material, it triggers the coincident incorporation of modular release sites to consolidate synaptic potentiation.
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Affiliation(s)
- Mathias A Böhme
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany.,Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Anthony W McCarthy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Andreas T Grasskamp
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - Christine B Beuschel
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany.,Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Meida Jusyte
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Desiree Laber
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - Sheng Huang
- Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Ulises Rey
- Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany.,Department of Theory and Bio-systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424, Potsdam, Germany
| | - Astrid G Petzoldt
- Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Fabian Göttfert
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | | | - Stefan W Hell
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - David Owald
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Stephan J Sigrist
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany. .,Institute for Biology/Genetics, Freie Universität Berlin, 14195, Berlin, Germany.
| | - Alexander M Walter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.
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18
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Russo A, Goel P, Brace EJ, Buser C, Dickman D, DiAntonio A. The E3 ligase Highwire promotes synaptic transmission by targeting the NAD-synthesizing enzyme dNmnat. EMBO Rep 2019; 20:e46975. [PMID: 30692130 PMCID: PMC6399608 DOI: 10.15252/embr.201846975] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/31/2018] [Accepted: 01/07/2019] [Indexed: 01/03/2023] Open
Abstract
The ubiquitin ligase Highwire restrains synaptic growth and promotes evoked neurotransmission at NMJ synapses in Drosophila Highwire regulates synaptic morphology by downregulating the MAP3K Wallenda, but excess Wallenda signaling does not account for the decreased presynaptic release observed in highwire mutants. Hence, Highwire likely has a second substrate that inhibits neurotransmission. Highwire targets the NAD+ biosynthetic and axoprotective enzyme dNmnat to regulate axonal injury responses. dNmnat localizes to synapses and interacts with the active zone protein Bruchpilot, leading us to hypothesize that Highwire promotes evoked release by downregulating dNmnat. Here, we show that excess dNmnat is necessary in highwire mutants and sufficient in wild-type larvae to reduce quantal content, likely via disruption of active zone ultrastructure. Catalytically active dNmnat is required to drive defects in evoked release, and depletion of a second NAD+ synthesizing enzyme is sufficient to suppress these defects in highwire mutants, suggesting that excess NAD+ biosynthesis is the mechanism inhibiting neurotransmission. Thus, Highwire downregulates dNmnat to promote evoked synaptic release, suggesting that Highwire balances the axoprotective and synapse-inhibitory functions of dNmnat.
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Affiliation(s)
- Alexandra Russo
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - E J Brace
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Chris Buser
- Oak Crest Institute of Science, Monrovia, CA, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
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19
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Kasbekar P, Goel P, Aravind S, Shukla H, Pandya S. The margin ratio hypothesis in cancer of buccal mucosa. Eur J Surg Oncol 2019. [DOI: 10.1016/j.ejso.2018.10.429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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20
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Abstract
Presynaptic boutons at nerve terminals are densely packed with synaptic vesicles, specialized organelles for rapid and regulated neurotransmitter secretion. Upon depolarization of the nerve terminal, synaptic vesicles fuse at specializations called active zones that are localized at discrete compartments in the plasma membrane to initiate synaptic transmission. A small proportion of synaptic vesicles are docked and primed for immediate fusion upon synaptic stimulation, which together comprise the readily releasable pool. The size of the readily releasable pool is an important property of synapses, which influences release probability and can dynamically change during various forms of plasticity. Here we describe a detailed protocol for estimating the readily releasable pool at a model glutamatergic synapse, the Drosophila neuromuscular junction. This synapse is experimentally robust and amenable to sophisticated genetic, imaging, electrophysiological, and pharmacological approaches. We detail the experimental design, electrophysiological recording procedure, and quantitative analysis necessary to determine the readily releasable pool size. This technique requires the use of a two-electrode voltage-clamp recording configuration in elevated external Ca2+ with high frequency stimulation. We have used this assay to measure the readily releasable pool size and reveal that a form of homeostatic plasticity modulates this pool with synapse-specific and compartmentalized precision. This powerful approach can be utilized to illuminate the dynamics of synaptic vesicle trafficking and plasticity and determine how synaptic function adapts and deteriorates during states of altered development, stress and neuromuscular disease.
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Affiliation(s)
- Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, USA
| | - Xiling Li
- Department of Neurobiology, University of Southern California, Los Angeles, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, USA
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21
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Fahradyan A, Tsuha M, Wolfswinkel E, Mitchel K, Howell L, Hammoudeh J, Urata M, Magee W, Goel P. The Optimal Timing of Secondary Alveolar Bone Grafting: A Literature Review. J Oral Maxillofac Surg 2018. [DOI: 10.1016/j.joms.2018.06.099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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22
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Kaushik A, Kapoor A, Agarwal SK, Pandey S, Kumar S, Khanna R, Garg N, Tewari S, Goel P. P3607Can high-dose statin therapy given before off-pump CABG “recapture” cardioprotection in patients already on chronic statin therapy: Assessment by serial cardiac biomarker assay. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p3607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- A Kaushik
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - A Kapoor
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - S K Agarwal
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - S Pandey
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - S Kumar
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - R Khanna
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - N Garg
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - S Tewari
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
| | - P Goel
- Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, India
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23
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Goel P, Li X, Dickman D. Disparate Postsynaptic Induction Mechanisms Ultimately Converge to Drive the Retrograde Enhancement of Presynaptic Efficacy. Cell Rep 2018; 21:2339-2347. [PMID: 29186673 DOI: 10.1016/j.celrep.2017.10.116] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/13/2017] [Accepted: 10/29/2017] [Indexed: 12/13/2022] Open
Abstract
Retrograde signaling systems are fundamental modes of communication synapses utilize to dynamically and adaptively modulate activity. However, the inductive mechanisms that gate retrograde communication in the postsynaptic compartment remain enigmatic. We have investigated retrograde signaling at the Drosophila neuromuscular junction, where three seemingly disparate perturbations to the postsynaptic cell trigger a similar enhancement in presynaptic neurotransmitter release. We show that the same presynaptic genetic machinery and enhancements in active zone structure are utilized by each inductive pathway. However, all three induction mechanisms differ in temporal, translational, and CamKII activity requirements to initiate retrograde signaling in the postsynaptic cell. Intriguingly, pharmacological blockade of postsynaptic glutamate receptors, and not calcium influx through these receptors, is necessary and sufficient to induce rapid retrograde homeostatic signaling through CamKII. Thus, three distinct induction mechanisms converge on the same retrograde signaling system to drive the homeostatic strengthening of presynaptic neurotransmitter release.
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Affiliation(s)
- Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA; Graduate Program in Molecular Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiling Li
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA.
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24
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Li X, Goel P, Chen C, Angajala V, Chen X, Dickman DK. Synapse-specific and compartmentalized expression of presynaptic homeostatic potentiation. eLife 2018; 7:34338. [PMID: 29620520 PMCID: PMC5927770 DOI: 10.7554/elife.34338] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/04/2018] [Indexed: 01/23/2023] Open
Abstract
Postsynaptic compartments can be specifically modulated during various forms of synaptic plasticity, but it is unclear whether this precision is shared at presynaptic terminals. Presynaptic homeostatic plasticity (PHP) stabilizes neurotransmission at the Drosophila neuromuscular junction, where a retrograde enhancement of presynaptic neurotransmitter release compensates for diminished postsynaptic receptor functionality. To test the specificity of PHP induction and expression, we have developed a genetic manipulation to reduce postsynaptic receptor expression at one of the two muscles innervated by a single motor neuron. We find that PHP can be induced and expressed at a subset of synapses, over both acute and chronic time scales, without influencing transmission at adjacent release sites. Further, homeostatic modulations to CaMKII, vesicle pools, and functional release sites are compartmentalized and do not spread to neighboring pre- or post-synaptic structures. Thus, both PHP induction and expression mechanisms are locally transmitted and restricted to specific synaptic compartments. Everything we think and do is the result of communication between neurons. This communication takes place at junctions called synapses. When two nerve cells or neurons communicate at a synapse, the output terminal of the first cell releases a chemical called a neurotransmitter. This binds to receiver proteins, or receptors, on the second cell. When this communication is interrupted, synapses can adapt to maintain a stable dialogue between them. This can occur in two ways. Either the first neuron starts to release more neurotransmitter from its output terminal, or the second neuron produces extra receptors with which to detect the neurotransmitter. But how specific are these changes? The brain contains far more synapses than neurons because each neuron can form synapses with many other cells. Can a neuron adjust how much of the neurotransmitter it releases at some of its synapses while leaving the others unchanged? Li et al. have now addressed this question by studying a special type of synapse that forms between neurons and muscles, known as a neuromuscular junction. At one particular neuromuscular junction in fruit flies, a single neuron splits into two output terminals, each of which forms a synapse with a different muscle. Li et al. show that when the number of neurotransmitter receptors in one of the muscles is artificially reduced, the associated output terminal compensates by increasing its neurotransmitter release. By contrast, the other output terminal remains unaffected. This suggests that a neuron can induce remarkably specific changes in a subset of its synapses. This discovery paves the way towards identifying the smallest possible unit of change that can occur in the neurons’ ability to communicate. This unit may in turn be the smallest change that can support learning. Such knowledge will help us understand how the nervous system processes and stabilizes information transfer, both in health and after injury or disease.
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Affiliation(s)
- Xiling Li
- Department of Neurobiology, University of Southern California, Los Angeles, United States.,Neuroscience Graduate Program, University of Southern California, California, United States
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, United States.,Graduate Program in Molecular and Computational Biology, University of Southern California, California, United States
| | - Catherine Chen
- Department of Neurobiology, University of Southern California, Los Angeles, United States
| | | | - Xun Chen
- Neuroscience Graduate Program, University of Southern California, California, United States
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25
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Costa R, Seth A, Chandra P, Bhal V, Nanjappa M, Rath P, Kalaricka M, Wander G, Mahajan A, Kumaran A, Koshy A, Goel P, Kumar V, Kaul U, Trehan V. 1968Quantitative angiographic analysis in patients with de novo native coronary artery lesions treated with novel poly-l-lactide based sirolimus-eluting bioresorbable vascular scaffold: MeRes-1 Trial. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.1968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Bhagat N, Whitelock J, Goel P, Barcia P, Hashemi E, Anderson P, Ambarus T. An Atypical Presentation of the Most Common Uterine Anomaly: The Septate Uterus. J Minim Invasive Gynecol 2016. [DOI: 10.1016/j.jmig.2016.08.786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Gupta K, Mitra S, Kazal S, Saroa R, Ahuja V, Goel P. I.V. paracetamol as an adjunct to patient-controlled epidural analgesia with levobupivacaine and fentanyl in labour: a randomized controlled study. Br J Anaesth 2016; 117:617-622. [DOI: 10.1093/bja/aew311] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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28
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Gupta V, Garg R, Huria A, Goel P, Chander J, Cruz SD. Effect of genitourinary flora on occurrence of recurrent urinary tract infection in females. Indian J Med Microbiol 2016; 34:112-3. [PMID: 26776136 DOI: 10.4103/0255-0857.167673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- V Gupta
- Department of Microbiology, Government Medical College Hospital, Chandigarh, India
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29
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Tewari S, Agarwal P, Goel P. PS055 To Evaluate the Role of Non Hdl-C, Lp(a), Apo-B as a Clinical Surrogate Marker for Coronary Artery Disease. Glob Heart 2016. [DOI: 10.1016/j.gheart.2016.03.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Tewari S, Sahoo D, Goel P. PS217 To Correlate Carotid Artery Intima-Media Thickness and Plaque Score With the Syntax Score for Assessing the Complexity of Coronary Artery Disease. Glob Heart 2016. [DOI: 10.1016/j.gheart.2016.03.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Kumar S, Singhal A, Kapoor A, Khanna R, Garg N, Tewari S, Goel P. PM281 Continued Improvement of RV Function After 3 Months of Balloon Mitral Valvotomy: A Comprehensive Echocardiography Study. Glob Heart 2016. [DOI: 10.1016/j.gheart.2016.03.408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Dantas Machado AC, Zhou T, Rao S, Goel P, Rastogi C, Lazarovici A, Bussemaker HJ, Rohs R. Evolving insights on how cytosine methylation affects protein-DNA binding. Brief Funct Genomics 2015; 14:61-73. [PMID: 25319759 PMCID: PMC4303714 DOI: 10.1093/bfgp/elu040] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Many anecdotal observations exist of a regulatory effect of DNA methylation on gene expression. However, in general, the underlying mechanisms of this effect are poorly understood. In this review, we summarize what is currently known about how this important, but mysterious, epigenetic mark impacts cellular functions. Cytosine methylation can abrogate or enhance interactions with DNA-binding proteins, or it may have no effect, depending on the context. Despite being only a small chemical change, the addition of a methyl group to cytosine can affect base readout via hydrophobic contacts in the major groove and shape readout via electrostatic contacts in the minor groove. We discuss the recent discovery that CpG methylation increases DNase I cleavage at adjacent positions by an order of magnitude through altering the local 3D DNA shape and the possible implications of this structural insight for understanding the methylation sensitivity of transcription factors (TFs). Additionally, 5-methylcytosines change the stability of nucleosomes and, thus, affect the local chromatin structure and access of TFs to genomic DNA. Given these complexities, it seems unlikely that the influence of DNA methylation on protein-DNA binding can be captured in a small set of general rules. Hence, data-driven approaches may be essential to gain a better understanding of these mechanisms.
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Krestjyaninov M, Gimaev R, Razin V, Halaph H, Shameeva O, Galli E, Oger E, Levery M, Mabo P, Donal E, Rodriguez Munoz D, Carbonell Sanroman A, Moya Mur J, Lazaro Rivera C, Fernandez Santos S, Rincon Diaz L, Casas Rojo E, Jimenez Nacher J, Fernandez-Golfin C, Zamorano Gomez J, Shamsheva D, Zaletova T, Parkhomenko O, Bogdanov A, Simova I, Katova T, Galderisi M, Pauncheva B, Ozawa K, Funabashi N, Takaoka H, Kobayashi Y, Moatemri F, Messaoudi Y, Mahdhaoui A, Bouraoui H, Hajri S, Jeridi G, Souza C, Nascimento C, Cordovil I, Belem L, Horcades R, Sahate A, Pereira S, Benchimol-Barbosa P, Barros C, Weitzel L, Altin C, Sade L, Gezmis E, Ozen N, Muderrisoglu H, Voilliot D, Magne J, Dulgheru R, Kou S, Henri C, Caballero L, De Sousa C, Sprynger M, Pierard L, Lancellotti P, Miglioranza M, Mihaila S, Muraru D, Cucchini U, Cecchetto A, Cavalli G, Romeo G, Iliceto S, Badano L, Brecht A, Wageloehner T, Oertelt-Prigione S, Seeland U, Ruecke M, Baumann G, Regitz-Zagrosek V, Stangl V, Knebel F, Khanna R, Raghuwanshi A, Kapoor A, Tewari S, Garg N, Kumar S, Goel P, Altin C, Sade L, Gezmis E, Ozen N, Duzceker O, Muderrisoglu H, Petre I, Tautu O, Onciul S, Iancovici S, Zamfir D, Onut R, Dorobantu M, Jashari F, Ibrahimi P, Johansson E, Gronlund C, Bajraktari G, Wester P, Henein M, Torbas O, Sirenko Y, Radchenko G, Page M, Gerber B, Pasquet A, Pouleur A, Vancreynest D, Vanoverschelde J, Wieczorek J, Wieczorek P, Mizia M, Gieszczyk-Strozik K, Sikora-Puz A, Lasota B, Mizia-Stec K, Coisne A, Levy F, Malaquin D, Richardson M, Quere J, Montaigne D, Tribouilloy C, Miskowiec D, Wierzbowska-Drabik K, Wejner-Mik P, Michalski B, Wdowiak-Okrojek K, Szymczyk E, Kasprzak J, Lipiec P, Grossi F, Oddo A, Pieri F, Cordisco A, Zucchini M, Mori F, Gensini G. Club 35 Poster session 1: Wednesday 3 December 2014, 09:00-16:00 * Location: Poster area. Eur Heart J Cardiovasc Imaging 2014. [DOI: 10.1093/ehjci/jeu238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
Background: An outfall of urbanization in developing countries has been the mushrooming of slums where dwellers live in pitiable environmental conditions representing the lowest rung of social strata. This group is more vulnerable to practicing deleterious social habits, including tobacco and alcohol abuse. Aim: The present study was undertaken to understand the strength of association between risk factors suspected of causing oral precancer among slum dwellers in Delhi. Subjects and Methods: A house-to-house survey was conducted in an urban slum cluster situated in the heart of Delhi city by a single trained investigator who recorded oral mucosal lesions according to WHO criteria. Demographic details and history of suspected risk factors was recorded by personal interview of each subject. The obtained data was coded, cleaned, and analyzed manually. Chi-square test was applied and Odds’ ratios were calculated to analyze the association of risk factors with oral precancer. A statistically significant difference was set at 95% confidence interval. Results: A total of 479 subjects of both sexes were examined and 31 cases clinically diagnosed as having oral precancer, of which majority were leukoplakia. All cases except one reported practicing habits that are known risk factors for oral precancer, i.e., smoking/smokeless tobacco, chewing betel leaf/nut, and combination of these habits with alcohol. Association of oral precancer with smokeless tobacco was higher than that with smoking or chewing betel leaf/nut alone. Conclusion: Practicing combination of habits with alcohol was found to be the most strongly associated risk factor for oral precancer.
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Affiliation(s)
- A Goel
- Rajasthan Dental College, Jaipur, Rajasthan, India
| | - P Goel
- Dental Wing, All India Institute of Medical Sciences (AIIMS), Bhopal, India
| | - S Mishra
- Department of Pediatric Dentistry, Ministry of Health, Kuwait
| | - R Saha
- Department of Statistics, Ma ulana Azad Medical College, New Delhi, India
| | - Na Torwane
- Department of Public Health Dentistry, People's Dental Academy, People's University, Bhopal, Madhya Pradesh, India
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Kapur-Ghai J, Kaur M, Goel P. Development of enzyme linked immunosorbent assay (ELISA) for the detection of root-knot nematode Meloidogyne incognita. J Parasit Dis 2014; 38:302-6. [PMID: 25035590 DOI: 10.1007/s12639-013-0246-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 01/11/2013] [Indexed: 10/27/2022] Open
Abstract
Root-knot nematodes (Meloidogyne incognita) are obligate, sedentary plant endoparasites that are extremely polyphagous in nature and cause severe economic losses in agriculture. Hence, it is essential to control the parasite at an early stage. For any control strategy to be effective, an early and accurate diagnosis is of paramount importance. Immunoassays have the inherent advantages of sensitivity and specificity; have the potential to identify and quantify these plant-parasitic nematodes. Hence, in the present studies, enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of M.incognita antigens. First an indirect ELISA was developed for detection and titration of anti-M.incognita antibodies. Results indicated as high as 320 K titre of the antisera. Finally competitive inhibition ELISA was developed employing these anti-M.incognita antibodies for detection of M.incognita antigens. Sensitivity of ELISA was 10 fg. Competitive inhibition ELISA developed in the present studies has the potential of being used as an easy, rapid, specific and sensitive diagnostic tool for the detection of M.incognita infection.
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Affiliation(s)
- J Kapur-Ghai
- Department of Zoology, Punjab Agricultural University, Ludhiana, 141004 India
| | - M Kaur
- Department of Zoology, Punjab Agricultural University, Ludhiana, 141004 India
| | - P Goel
- Amity Institute of Biotechnology, Amity University, Noida, India
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Ganavadiya R, Chandrashekar B, Goel P, Hongal S, Jain M. Mobile and portable dental services catering to the basic oral health needs of the underserved population in developing countries: a proposed model. Ann Med Health Sci Res 2014; 4:293-304. [PMID: 24971198 PMCID: PMC4071723 DOI: 10.4103/2141-9248.133364] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
India is the second most populous country in the world with an extensive rural population (68.8%). Children less than 18 years constitute about 40% of the population. Approximately, 23.5% of the urban population resides in urban slums. The extensive rural population, school children and the urban slum dwellers are denied of even the basic dental services though there is continuous advancement in the field of dentistry. The dentist to population ratio has dramatically improved in the last one to two decades with no significant improvement in the oral health status of the general population. The various studies have revealed an increasing trend in oral diseases in the recent times especially among this underserved population. Alternate strategies have to be thought about rather than the traditional oral health-care delivery through private dentists on fee for service basis. Mobile and portable dental services are a viable option to take the sophisticated oral health services to the doorsteps of the underserved population. The databases were searched for publications from 1900 to the present (2013) using terms such as Mobile dental services, Portable dental services and Mobile and portable dental services with key articles obtained primarily from MEDLINE. This paper reviews the published and unpublished literature from different sources on the various mobile dental service programs successfully implemented in some developed and developing countries. Though the mobile and portable systems have some practical difficulties like financial considerations, they still seem to be the only way to reach every section of the community in the absence of national oral health policy and organized school dental health programs in India. The material for the present review was obtained mainly by searching the biomedical databases for primary research material using the search engine with key words such as mobile and/or portable dental services in developed and developing countries (adding each of these terms in a sequential order). Based on the review of the programs successfully implemented in developed countries, we propose a model to cater to the basic oral health needs of an extensive underserved population in India that may be pilot tested. The increasing dental manpower can best be utilized for the promotion of oral health through mobile and portable dental services. The professional dental organizations should have a strong motive to translate this into reality.
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Affiliation(s)
- R Ganavadiya
- Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, Madhya Pradesh, India
| | - Br Chandrashekar
- Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, Madhya Pradesh, India
| | - P Goel
- Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, Madhya Pradesh, India
| | - Sg Hongal
- Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, Madhya Pradesh, India
| | - M Jain
- Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, Madhya Pradesh, India
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Goel P, Kuceyeski A, LoCastro E, Raj A. Spatial patterns of genome-wide expression profiles reflect anatomic and fiber connectivity architecture of healthy human brain. Hum Brain Mapp 2014; 35:4204-18. [PMID: 24677576 DOI: 10.1002/hbm.22471] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 11/30/2013] [Accepted: 01/06/2014] [Indexed: 11/07/2022] Open
Abstract
Unraveling the relationship between molecular signatures in the brain and their functional, architectonic, and anatomic correlates is an important neuroscientific goal. It is still not well understood whether the diversity demonstrated by histological studies in the human brain is reflected in the spatial patterning of whole brain transcriptional profiles. Using genome-wide maps of transcriptional distribution of the human brain by the Allen Brain Institute, we test the hypothesis that gene expression profiles are specific to anatomically described brain regions. In this work, we demonstrate that this is indeed the case by showing that gene similarity clusters appear to respect conventional basal-cortical and caudal-rostral gradients. To fully investigate the causes of this observed spatial clustering, we test a connectionist hypothesis that states that the spatial patterning of gene expression in the brain is simply reflective of the fiber tract connectivity between brain regions. We find that although gene expression and structural connectivity are not determined by each other, they do influence each other with a high statistical significance. This implies that spatial diversity of gene expressions is a result of mainly location-specific features but is influenced by neuronal connectivity, such that like cellular species preferentially connects with like cells.
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Affiliation(s)
- Pragya Goel
- Department of Computer Science, Cornell University, Ithaca, New York
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Sous J, Goel P, Nooijen M. Similarity transformed equation of motion coupled cluster theory revisited: a benchmark study of valence excited states. Mol Phys 2013. [DOI: 10.1080/00268976.2013.847216] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Goel P, Isher H, Saha PK, Tendon R, Devi L, Dhami GP. Lamotrigine Induced Hypersensitivity Syndrome in Pregnancy. Nepal j obstet gynaecol 2013. [DOI: 10.3126/njog.v7i1.8843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nepal Journal of Obstetrics and Gynaecology / Vol 7 / No. 1 / Issue 13 / Jan- June, 2012 / 68-70 DOI: http://dx.doi.org/10.3126/njog.v7i1.8843
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Abstract
Uterine granulomas confined to the myometrium are uncommon. Granulomas maybe infectious, non-infectious or idiopathic in origin. They may be diffuse or focal in nature. In this report, we describe two cases of granulomas of diffuse variety involving the myometrium. The first case shows non-necrotizing granuloma probably related to previous instrumentation. The second case depicts caseating granulomas along with Leiomyoma of uterus.
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Affiliation(s)
- Navneet Takkar
- Departments of Pathology, Obstetrics and Gynaecology, Government Medical College and Hospital, Chandigarh, Haryana and Punjab, India
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Dhir V, Singla M, Gupta N, Goel P, Sagar V, Sharma A, Sharma S, Singh S. THU0257 Randomized Controlled Trial Comparing Starting Dose of 7.5 mg and 15 mg Per Week of Methotrexate in Rheumatoid Arthritis. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2013-eular.785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bajpai M, Goel P, Bhutia O, Gupta A, Seth A, Gupta AK, Pawar DK. Massive ossifying fibroma of the mandible in a child. J Indian Assoc Pediatr Surg 2013; 18:20-2. [PMID: 23599578 PMCID: PMC3628239 DOI: 10.4103/0971-9261.107011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
An interesting case of large ossifying fibroma of the mandible in a child with a sickle-cell trait is reported.
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Affiliation(s)
- Minu Bajpai
- Department of Paediatric Surgery, All India Institute of Medical Sciences, New Delhi, India
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Abstract
A 22-years-old lady presented with obstructed labor with a probable preoperative diagnosis of bladder/urethral injury. When a laparotomy was performed there was a complete urethral disruption at the vesicourethral junction with a big anterior forniceal tear in the vagina with intact uterus and cervix. The fetus had pushed itself through the upper vagina and bladder neck into the extraperitoneal space leading to complete urethrovesical disruption as a result of prolonged pressure on the vesicourethral junction against pubic symphysis for which an end to end anastomosis was performed. Although trauma has been mentioned as a cause of such urethral disruption in the literature, no such case has been reported so far following obstructed labor. A brief discussion of various surgical options for such cases is discussed.
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Affiliation(s)
- S Arora
- Department of Obstetrics, Gynecology, Government Medical College and Hospital, Chandigarh, Punjab, India
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Yoshida T, Yamashita M, Hayashi M, Pletinck A, Glorieux G, Schepers E, Van Landschoot M, Van de Voorde J, Van Biesen W, Vanholder R, Yagi Y, Ito S, Goto S, Osaka M, Yoshida M, Pisoni R, Pisoni R, Fuller D, Fluck R, Fort J, Locatelli F, Spergel L, Goodkin D, Port F, Robinson B, Wilson S, Robertson J, Chen G, Goel P, Benner D, Krishnan M, Mayne T, Nissenson A. Vascular damage and access in CKD. Nephrol Dial Transplant 2012. [DOI: 10.1093/ndt/gfs251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Unnikrishnan B, Rao P, Kumar N, Ganti S, Prasad R, Amarnath A, Reshmi B, Kaur V, Kesharwani P, Seetha M, Nautiyal A, Goel P, Aggarwal P. Profile of blood donors and reasons for deferral in coastal South India. Australas Med J 2011; 4:379-85. [PMID: 23393523 DOI: 10.4066/amj.2011.641] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND A blood transfusion is a life-saving procedure in many instances. An adequate supply of safe blood is ensured by exercising donor deferral criteria and screening for Transfusion Transmitted Infections (TTI). The aim of this paper is to study the profile of blood donors and reasons for donor deferral in coastal South India. METHOD The study was conducted at a tertiary care hospital in Mangalore. All those who donated between 1 January 2008 and 31 December 2008 were included in the study. Data was collected using a pre-tested semi-structured proforma and analysed using SPSS version 11.5. RESULTS Most of the donors were under the age of 25 (42.92%). Donors were predominantly male (95.20%). In terms of occupation, most subjects were students (28.01%) followed by businessmen (18.61%). Slightly more than three-quarters of the donors (77.20%) were replacement donors. The main reasons for deferral were consumption of medication in the past 72 hours (15.15%), hypertension (13.18%), a low haemoglobin level (12.34%) and alcohol intake in the past 72 hours (12.20%). Among the TTIs identified, most samples were positive for Hepatitis B surface Antigen - HBsAg (0.87%) or tested positive for Anti-Hepatitis C (HCV antibodies (0.36%). CONCLUSION From the study it was concluded that the majority of the donor population was young and educated. The reason for donation was mainly replacement rather than voluntary. This issue needs to be addressed by exercising proactive measures to increase the number of voluntary, nonremunerated, low-risk donors.
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Goel P, Srivastava K, Das N, Bhatnagar V. The role of nitric oxide in portal hypertension caused by extrahepatic portal vein obstruction. J Indian Assoc Pediatr Surg 2011; 15:117-21. [PMID: 21170192 PMCID: PMC2995934 DOI: 10.4103/0971-9261.72433] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Aims: Nitric oxide (NO) in peripheral venous blood has been shown to be elevated in experimental portal hypertension. This study aims to determine the serum NO levels in patients with extrahepatic portal venous hypertension (EHPVO) pre- and postoperatively and to analyze whether these can serve as a reliable and early indicator of shunt blockage or malfunction. Materials and Methods: During the period 2006–2010, 48 children with EHPVO were included in this prospective study; 40 underwent porto-systemic shunt and eight underwent splenectomy with devascularization. NO was evaluated preoperatively, 14 days after surgery, at 3 months and then 6 monthly thereafter. The median follow-up duration was 21 months. Shunt patency was confirmed with Doppler and computed tomography portography. Forty-eight age-matched children with hypospadias served as controls. Results: NO was higher in EHPVO patients as compared with controls (43.16 ± 16.27 vs. 5.76 ± 2.62 μmol/l) (P = 0.0001). There was a significant decline in the NO levels (4.64 ± 3.18 μmol/l) following shunt surgery (P = 0.0001), and it continued to remain low till the shunt was patent. A shunt block was indicated by rising NO levels in all five patients. The devascularization group also demonstrated a significant decline in the NO levels (27.06 ± 3.56 μmol/l) (P = 0.002), but it was less as compared with the shunted patients. The decline in the portal pressure after shunt surgery was found to correlate with the decline in the serum NO levels. Conclusions: The blood levels of NO can be used in the diagnosis of portal hypertension, and are useful for monitoring the patency of the shunt.
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Affiliation(s)
- P Goel
- Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi - 110 029, India
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Abstract
INTRODUCTION:
Puberty menorrhagia is a significant health problem in adolescent age group and severe cases may require admission and blood transfusion. Aim of this study was to evaluate the causes, associated complications and management of puberty menorrhagia.
METHODS:
Hospital records of all patients of puberty menorrhagia requiring admission were analyzed for etiology, duration since menarche, duration of bleeding, investigation profile and management.
RESULTS:
There were 18 patients of puberty menorrhagia requiring hospital admission. Etiology was anovulatory bleeding in 11 patients, bleeding disorders in five which included idiopathic thrombocytopenia purpura in three and one each with Von-Willebrand disease and leukemia. Two patients had hypothyroidism as the cause. Fourteen patients presented with severe anaemia and required blood transfusion. All except one responded to oral hormonal therapy.
CONCLUSIONS:
Puberty menorrhagia can be associated with severe complications and requiring blood transfusion. Although most common cause is anovulation but bleeding disorder, other medical condition and other organic causes must be ruled out in any patient of Puberty menorrhagia.KEYWORDS: anovulation, bleeding disorder, puberty, menorrhagia, anaemia.
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Khosla AH, Devi L, Goel P, Saha PK. Puberty menorrhagia requiring inpatient admission. JNMA J Nepal Med Assoc 2010; 49:112-116. [PMID: 21485595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
INTRODUCTION Puberty menorrhagia is a significant health problem in adolescent age group and severe cases may require admission and blood transfusion. Aim of this study was to evaluate the causes, associated complications and management of puberty menorrhagia. METHODS Hospital records of all patients of puberty menorrhagia requiring admission were analyzed for etiology, duration since menarche, duration of bleeding, investigation profile and management. RESULTS There were 18 patients of puberty menorrhagia requiring hospital admission. Etiology was anovulatory bleeding in 11 patients, bleeding disorders in five which included idiopathic thrombocytopenia purpura in three and one each with Von-Willebrand disease and leukemia. Two patients had hypothyroidism as the cause. Fourteen patients presented with severe anaemia and required blood transfusion. All except one responded to oral hormonal therapy. CONCLUSIONS Puberty menorrhagia can be associated with severe complications and requiring blood transfusion. Although most common cause is anovulation but bleeding disorder, other medical condition and other organic causes must be ruled out in any patient of Puberty menorrhagia.
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Affiliation(s)
- A H Khosla
- Department of Obstetrics & Gynaecology, Government Medical College and Hospital, Chandigarh, India
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50
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Abstract
Despite the refinements in surgical technique, rates of homologous blood transfusion (HBT) in cardiac surgery remain high. The adverse effects of blood transfusion are well documented. Retransfusion of shed mediastinal blood reduces the requirement for HBTs during conventional coronary artery bypass grafting. However, some studies have found that autotransfusion leads to bleeding diathesis and paradoxical increase in blood transfusions. Through this prospective randomized trial, we have studied the safety and efficacy of this modality in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Fifty patients enrolled in the study and 49 fulfilled the study criteria. They were randomly divided into group C (cell saver) and group N (non-cell saver). Whereas the cell saver group received processed shed autologous blood and homologous blood if necessary, the non-saver group was transfused homologous blood only. The threshold for transfusion was haemoglobin of 9 g dL(-1) in both the groups. The cell saver group required significantly less number of HBTs (1.6 +/- 1.2 vs. 2.4 +/- 1.3 units). The incidence of re-exploration was zero in both the groups. The mean mediastinal drainage in both the groups was not significantly different (355 +/- 196 vs. 316 +/- 119.8 mL). The number of patients requiring any blood transfusion however was very high. All the patients in the non-saver group and 20 (83%) of the patients in the saver group received homologous blood. During OPCAB surgery, the use of cell saver reduced the requirement for HBT. Its use is not associated with any clinically significant bleeding diathesis.
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Affiliation(s)
- P Goel
- Escorts Heart and Superspeciality Institute, Verka Majitha Byepass, Amritsar, Punjab, India.
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