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Espiritu MJ, Taylor JK, Sugai CK, Thapa P, Loening NM, Gusman E, Baoanan ZG, Baumann MH, Bingham JP. Characterization of the Native Disulfide Isomers of the Novel χ-Conotoxin PnID: Implications for Further Increasing Conotoxin Diversity. Mar Drugs 2023; 21:61. [PMID: 36827103 PMCID: PMC9964023 DOI: 10.3390/md21020061] [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] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
χ-Conotoxins are known for their ability to selectively inhibit norepinephrine transporters, an ability that makes them potential leads for treating various neurological disorders, including neuropathic pain. PnID, a peptide isolated from the venom of Conus pennaceus, shares high sequence homology with previously characterized χ-conotoxins. Whereas previously reported χ-conotoxins seem to only have a single native disulfide bonding pattern, PnID has three native isomers due to the formation of different disulfide bond patterns during its maturation in the venom duct. In this study, the disulfide connectivity and three-dimensional structure of these disulfide isomers were explored using regioselective synthesis, chromatographic coelution, and solution-state nuclear magnetic resonance spectroscopy. Of the native isomers, only the isomer with a ribbon disulfide configuration showed pharmacological activity similar to other χ-conotoxins. This isomer inhibited the rat norepinephrine transporter (IC50 = 10 ± 2 µM) and has the most structural similarity to previously characterized χ-conotoxins. In contrast, the globular isoform of PnID showed more than ten times less activity against this transporter and the beaded isoform did not display any measurable biological activity. This study is the first report of the pharmacological and structural characterization of an χ-conotoxin from a species other than Conus marmoreus and is the first report of the existence of natively-formed conotoxin isomers.
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Affiliation(s)
- Michael J. Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Jonathan K. Taylor
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Christopher K. Sugai
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Nikolaus M. Loening
- Department of Chemistry, Lewis & Clark College, 615 S Palatine Hill Road, Portland, OR 97219, USA
| | - Emma Gusman
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Zenaida G. Baoanan
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- Department of Biology, College of Science, University of the Philippines Baguio, Baguio City 2600, Philippines
| | - Michael H. Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 333 Cassell Drive Suite 4400, Baltimore, MD 21224, USA
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
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Wiere S, Sugai C, Espiritu MJ, Aurelio VP, Reyes CD, Yuzon N, Whittal RM, Tytgat J, Peigneur S, Bingham JP. Research into the Bioengineering of a Novel α-Conotoxin from the Milked Venom of Conus obscurus. Int J Mol Sci 2022; 23:12096. [PMID: 36292948 PMCID: PMC9602734 DOI: 10.3390/ijms232012096] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/04/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022] Open
Abstract
The marine cone snail produces one of the fastest prey strikes in the animal kingdom. It injects highly efficacious venom, often causing prey paralysis and death within seconds. Each snail has hundreds of conotoxins, which serve as a source for discovering and utilizing novel analgesic peptide therapeutics. In this study, we discovered, isolated, and synthesized a novel α3/5-conotoxins derived from the milked venom of Conus obscurus (α-conotoxin OI) and identified the presence of α-conotoxin SI-like sequence previously found in the venom of Conus striatus. Five synthetic analogs of the native α-conotoxin OI were generated. These analogs incorporated single residue or double residue mutations. Three synthetic post-translational modifications (PTMs) were synthetically incorporated into these analogs: N-terminal truncation, proline hydroxylation, and tryptophan bromination. The native α-conotoxin OI demonstrated nanomolar potency in Poecilia reticulata and Homosapiens muscle-type nicotinic acetylcholine receptor (nAChR) isoforms. Moreover, the synthetic α-[P9K] conotoxin OI displayed enhanced potency in both bioassays, ranging from a 2.85 (LD50) to 18.4 (IC50) fold increase in comparative bioactivity. The successful incorporation of PTMs, with retention of both potency and nAChR isoform selectivity, ultimately pushes new boundaries of peptide bioengineering and the generation of novel α-conotoxin-like sequences.
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Affiliation(s)
- Sean Wiere
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Christopher Sugai
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Michael J. Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- School of Pharmacy, Pacific University Oregon, Hillsboro, OR 97123, USA
| | - Vincent P. Aurelio
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Chloe D. Reyes
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Nicole Yuzon
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Randy M. Whittal
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, 3000 Leuven, Belgium
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, 3000 Leuven, Belgium
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
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Espiritu MJ, Chen J, Yadav J, Larkin M, Pelletier RD, Chan JM, Gc JB, Natesan S, Harrelson JP. Mechanisms of Herb-Drug Interactions Involving Cinnamon and CYP2A6: Focus on Time-Dependent Inhibition by Cinnamaldehyde and 2-Methoxycinnamaldehyde. Drug Metab Dispos 2020; 48:1028-1043. [PMID: 32788161 DOI: 10.1124/dmd.120.000087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/15/2020] [Indexed: 12/21/2022] Open
Abstract
Information is scarce regarding pharmacokinetic-based herb-drug interactions (HDI) with trans-cinnamaldehyde (CA) and 2-methoxycinnamaldehyde (MCA), components of cinnamon. Given the presence of cinnamon in food and herbal treatments for various diseases, HDIs involving the CYP2A6 substrates nicotine and letrozole with MCA (KS = 1.58 µM; Hill slope = 1.16) and CA were investigated. The time-dependent inhibition (TDI) by MCA and CA of CYP2A6-mediated nicotine metabolism is a complex process involving multiple mechanisms. Molecular dynamic simulations showed that CYP2A6's active site accommodates two dynamic ligands. The preferred binding orientations for MCA and CA were consistent with the observed metabolism: epoxidation, O-demethylation, and aromatic hydroxylation of MCA and cinnamic acid formation from CA. The percent remaining activity plots for TDI by MCA and CA were curved, and they were analyzed with a numerical method using models of varying complexity. The best-fit models support multiple inactivator binding, inhibitor depletion, and partial inactivation. Deconvoluted mass spectra indicated that MCA and CA modified CYP2A6 apoprotein with mass additions of 156.79 (142.54-171.04) and 132.67 (123.37-141.98), respectively, and it was unaffected by glutathione. Heme degradation was observed in the presence of MCA (48.5% ± 13.4% loss; detected by liquid chromatography-tandem mass spectrometry). In the absence of clinical data, HDI predictions were made for nicotine and letrozole using inhibition parameters from the best-fit TDI models and parameters scaled from rats. Predicted area under the concentration-time curve fold changes were 4.29 (CA-nicotine), 4.92 (CA-letrozole), 4.35 (MCA-nicotine), and 5.00 (MCA-letrozole). These findings suggest that extensive exposure to cinnamon (corresponding to ≈ 275 mg CA) would lead to noteworthy interactions. SIGNIFICANCE STATEMENT: Human exposure to cinnamon is common because of its presence in food and cinnamon-based herbal treatments. Little is known about the risk for cinnamaldehyde and methoxycinnamaldehyde, two components of cinnamon, to interact with drugs that are eliminated by CYP2A6-mediated metabolism. The interactions with CYP2A6 are complex, involving multiple-ligand binding, time-dependent inhibition of nicotine metabolism, heme degradation, and apoprotein modification. An herb-drug interaction prediction suggests that extensive exposure to cinnamon would lead to noteworthy interactions with nicotine.
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Affiliation(s)
- Michael J Espiritu
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Justin Chen
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Jaydeep Yadav
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Michael Larkin
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Robert D Pelletier
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Jeannine M Chan
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Jeevan B Gc
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - Senthil Natesan
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
| | - John P Harrelson
- School of Pharmacy, Pacific University Oregon, Hillsboro, Oregon (M.J.E., M.L., J.P.H.); College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington (J.C., J.B.G., S.N.); Amgen, Cambridge, Massachusetts (J.Y.); Department of Medicinal Chemistry, University of Washington, Seattle, Washington (R.D.P.); and Chemistry Department, Pacific University Oregon, Forest Grove, Oregon (J.M.C.)
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Zhang RY, Thapa P, Espiritu MJ, Menon V, Bingham JP. From nature to creation: Going around in circles, the art of peptide cyclization. Bioorg Med Chem 2018; 26:1135-1150. [DOI: 10.1016/j.bmc.2017.11.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 02/02/2023]
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Thapa P, Cabalteja CC, Philips EE, Espiritu MJ, Peigneur S, Mille BG, Tytgat J, Cummins TR, Bingham JP. t-boc synthesis of huwentoxin-i through native chemical ligation incorporating a trifluoromethanesulfonic acid cleavage strategy. Biopolymers 2017; 106:737-45. [PMID: 27271997 DOI: 10.1002/bip.22887] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/24/2016] [Accepted: 05/31/2016] [Indexed: 11/10/2022]
Abstract
Tert-butyloxycarbonyl (t-Boc)-based native chemical ligation (NCL) techniques commonly employ hydrogen fluoride (HF) to create the thioester fragment required for the ligation process. Our research aimed to assess the replacement of HF with Trifluoromethanesulfonic acid (TFMSA). Here we examined a 33 amino acid test peptide, Huwentoxin-I (HwTx-I) as a novel candidate for our TFMSA cleavage protocol. Structurally HwTx-I has an X-Cys(16) -Cys(17) -X sequence mid-region, which makes it an ideal candidate for NCL. Experiments determined that the best yields (16.8%) obtained for 50 mg of a thioester support resin were achieved with a TFMSA volume of 100 μL with a 0.5-h incubation on ice, followed by 2.0 h at room temperature. RP-HPLC/UV and mass spectra indicated the appropriate parent mass and retention of the cleaved HwTx-I N-terminal thioester fragment (Ala(1) -Cys(16) ), which was used in preparation for NCL. The resulting chemically ligated HwTx-I was oxidized/folded, purified, and then assessed for pharmacological target selectivity. Native-like HwTx-I produced by this method yielded an EC50 value of 340.5 ± 26.8 nM for Nav 1.2 and an EC50 value of 504.1 ± 81.3 nM for Nav 1.3, this being similar to previous literature results using native material. This article represents the first NCL based synthesis of this potent sodium channel blocker. Our illustrated approach removes potential restrictions in the advancement of NCL as a common peptide laboratory technique with minimal investment, and removes the hazards associated with HF usage. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 737-745, 2016.
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Affiliation(s)
- Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, HI, 96822
| | - Chino C Cabalteja
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, HI, 96822
| | - Edwin E Philips
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, HI, 96822
| | - Michael J Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, HI, 96822
| | - Steve Peigneur
- Department of Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, Leuven, 3000, Belgium
| | - Bea G Mille
- Department of Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, Leuven, 3000, Belgium
| | - Jan Tytgat
- Department of Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, Leuven, 3000, Belgium
| | - Theodore R Cummins
- Department of Pharmacology and Toxicology, Indiana University, Indianapolis, IN.,Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, 320 West 25th Street, NB-414F, Indianapolis, IN, 46202-2266
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, HI, 96822.
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Khanifar AA, Espiritu MJ, Myung JS, Aaker GD, Schuetz AN, D'Amico DJ, Chan RVP. Three-dimensional spectral domain optical coherence tomography and light microscopy of an intravitreal parasite. J Ophthalmic Inflamm Infect 2015; 5:33. [PMID: 26585462 PMCID: PMC4653122 DOI: 10.1186/s12348-015-0064-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/05/2015] [Indexed: 11/29/2022] Open
Abstract
Background Various imaging modalities play a role in diagnosing parasitic infections of the eye. We describe the spectral domain optical coherence tomography (SD-OCT) findings of an intravitreal parasite with subsequent evaluation by light microscopy. Findings This is a case report of a 37-year-old Ecuadorian man who presented with uveitic glaucoma and a new floater in his left eye for 1 week’s duration. Full ophthalmic examination revealed an intravitreal parasite. Color fundus photography, fluorescein angiography (FA), ocular ultrasonography (US), and SD-OCT were performed. The parasite was removed via 23-gauge pars plana vitrectomy and sent to pathology for evaluation. Color fundus photography and ocular ultrasonography demonstrated an elongated foreign body within the vitreous above the retina. FA demonstrated minimal vascular changes in the vicinity of the parasite. SD-OCT was utilized to visualize the parasite and to create a three-dimensional (3D) image. The parasite was determined to be most consistent with Gnathostoma spp. by morphologic analysis. Conclusions This is the first reported case of SD-OCT of an intravitreal parasite with corresponding evaluation by pathology. SD-OCT allows non-invasive, high-resolution visualization and 3D reconstruction of parasitic anatomy which may help establish tomographic criteria for species identification. Electronic supplementary material The online version of this article (doi:10.1186/s12348-015-0064-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aziz A Khanifar
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
| | - Michael J Espiritu
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
| | - Jane S Myung
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
| | - Grant D Aaker
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
| | - Audrey N Schuetz
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA.
| | - Donald J D'Amico
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
| | - R V Paul Chan
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA. .,Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL, USA.
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Thapa P, Espiritu MJ, Cabalteja C, Bingham JP. The Emergence of Cyclic Peptides: The Potential of Bioengineered Peptide Drugs. Int J Pept Res Ther 2014. [DOI: 10.1007/s10989-014-9421-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Espiritu MJ, Collier AC, Bingham JP. A 21st-century approach to age-old problems: the ascension of biologics in clinical therapeutics. Drug Discov Today 2014; 19:1109-13. [DOI: 10.1016/j.drudis.2014.01.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/31/2013] [Accepted: 01/20/2014] [Indexed: 01/07/2023]
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Thapa P, Espiritu MJ, Cabalteja CC, Bingham JP. Conotoxins and their regulatory considerations. Regul Toxicol Pharmacol 2014; 70:197-202. [PMID: 25013992 DOI: 10.1016/j.yrtph.2014.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [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: 06/20/2014] [Revised: 06/29/2014] [Accepted: 06/30/2014] [Indexed: 01/21/2023]
Abstract
Venom derived peptides from marine cone snails, conotoxins, have demonstrated unique pharmacological targeting properties that have been pivotal in advancing medical research. The awareness of their true toxic origins and potent pharmacological nature is emphasized by their 'select agent' classification by the US Centers for Disease Control and Prevention. We briefly introduce the biochemical and pharmacological aspects of conotoxins, highlighting current advancements into their biological engineering, and provide details to the present regulations that govern their use in research.
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Affiliation(s)
- Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA
| | - Michael J Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA
| | - Chino C Cabalteja
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA.
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Wong RK, Ventura CV, Espiritu MJ, Yonekawa Y, Henchoz L, Chiang MF, Lee TC, Chan RVP. Training fellows for retinopathy of prematurity care: a Web-based survey. J AAPOS 2012; 16:177-81. [PMID: 22525176 PMCID: PMC3338950 DOI: 10.1016/j.jaapos.2011.12.154] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [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] [Received: 09/26/2011] [Revised: 12/14/2011] [Accepted: 12/14/2011] [Indexed: 11/30/2022]
Abstract
PURPOSE To characterize the training received by pediatric ophthalmology and retina fellows in retinopathy of prematurity (ROP) management. METHODS Pediatric ophthalmology and retina fellowship programs were emailed a Web-based survey to assess fellowship training in ROP management. RESULTS Of 140 programs contacted, 42 (30%) participated, resulting in 87 surveys for analysis. Of the 87 respondents, 25 (29%) reported that two-thirds or less of ROP examinations performed by fellows were also seen by an attending. When stratified by specialty, this trend was statistically different between pediatric ophthalmology and retina fellows (P = 0.03). Additionally, pediatric ophthalmology fellows performed fewer laser photocoagulation procedures than retina fellows (P < 0.001). Regarding fellows' perceived competency in ROP management, 3 of 51 (6%) felt competent at the start of their fellowship and 43 of 51 (84%) felt competent at the time of the survey. Only 7% of respondents reported the use of formal evaluations at their programs to assess fellow competence in ROP examination. CONCLUSIONS Training programs for fellows in pediatric ophthalmology and retina vary greatly with respect to ROP training and the quality of clinical care. Many clinical ROP examinations are being performed by pediatric ophthalmology and retina fellows without involvement and/or direct supervision by attending ophthalmologists. Our findings have important implications for the development of a future workforce for ROP management.
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Affiliation(s)
- Ryan K Wong
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, USA
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Myung JS, Paul Chan RV, Espiritu MJ, Williams SL, Granet DB, Lee TC, Weissgold DJ, Chiang MF. Accuracy of retinopathy of prematurity image-based diagnosis by pediatric ophthalmology fellows: implications for training. J AAPOS 2011; 15:573-8. [PMID: 22153403 PMCID: PMC3240850 DOI: 10.1016/j.jaapos.2011.06.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [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] [Received: 02/23/2011] [Revised: 06/06/2011] [Accepted: 06/17/2011] [Indexed: 11/30/2022]
Abstract
PURPOSE To measure the accuracy of image-based retinopathy of prematurity (ROP) diagnosis by pediatric ophthalmology fellows. METHODS This was a comparative case series of expert versus nonexpert clinicians in image-based ROP diagnosis. An atlas of 804 retinal images was captured from 248 eyes of 67 premature infants with a wide-angle camera (RetCam-II, Clarity Medical Systems, Pleasanton, CA). Images were uploaded to a study website from which an expert pediatric retinal specialist and five pediatric ophthalmology fellows independently provided a diagnosis (no ROP, mild ROP, type 2 ROP, or treatment-requiring ROP) for each eye. Two different retinal specialists experienced in ROP examination served as additional controls. Primary outcome measures were sensitivity and specificity of image-based ROP diagnosis by fellows compared to a reference standard of image-based interpretation by the expert pediatric retinal specialist. Secondary outcome measure was intraphysician reliability. RESULTS For detection of mild or worse ROP, the mean (range) sensitivity among the five fellows was 0.850 (0.670-0.962) and specificity was 0.919 (0.832-0.964). For detection of type 2 or worse ROP by fellows, mean (range) sensitivity was 0.527 (0.356-0.709) and specificity was 0.938 (0.777-1.000). For detection of treatment-requiring ROP, mean (range) sensitivity was 0.515 (0.267-0.765) and specificity was 0.949 (0.805-1.00). CONCLUSIONS Pediatric ophthalmology fellows in this study demonstrated high diagnostic specificity in image-based ROP diagnosis; however, sensitivity was lower, particularly for clinically significant disease.
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Affiliation(s)
- Jane S Myung
- Department of Ophthalmology, Weill-Cornell Medical Center, New York, New York, USA
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