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Tae HS, Ortells MO, Yousuf A, Xu SQ, Akk G, Adams DJ, Arias HR. Tabernanthalog and ibogainalog inhibit the α7 and α9α10 nicotinic acetylcholine receptors via different mechanisms and with higher potency than the GABA A receptor and Ca V2.2 channel. Biochem Pharmacol 2024; 223:116183. [PMID: 38580167 DOI: 10.1016/j.bcp.2024.116183] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/19/2024] [Accepted: 03/29/2024] [Indexed: 04/07/2024]
Abstract
In this study, we have investigated the pharmacological activity and structural interaction of two novel psychoplastogens, tabernanthalog (TBG) and ibogainalog (IBG) at heterologously-expressed rat (r) and human (h) nicotinic acetylcholine receptors (nAChRs), the rα1β2γ2L γ-aminobutyric acid type A receptor (GABAAR), and the human voltage-gated N-type calcium channel (CaV2.2 channel). Both compounds inhibited the nAChRs with the following receptor selectivity: α9α10 > α7 > α3β2 ≅ α3β4, indicating that β2/β4 subunits are relatively less important for their activity. The potencies of TBG and IBG were comparable at hα7 and hα9α10 subtypes, and comparable to their rat counterparts. TBG- and IBG-induced inhibition of rα7 was ACh concentration-independent and voltage-dependent, whereas rα9α10 inhibition was ACh concentration-dependent and voltage-independent, suggesting that they interact with the α7 ion channel pore and α9α10 orthosteric ligand binding site, respectively. These results were supported by molecular docking studies showing that at the α7 model TBG forms stable interactions with luminal rings at 9', 13', and 16', whereas IBG mostly interacts with the extracellular-transmembrane junction. In the α9α10 model, however, these compounds interacted with several residues from the principal (+) and complementary (-) sides in the transmitter binding site. Ibogaminalog (DM506) also interacted with a non-luminal site at α7, and one α9α10 orthosteric site. TBG and IBG inhibited the GABAAR and CaV2.2 channels with 10 to 30-fold lower potencies. In sum, we show that TBG and IBG inhibit the α7 and α9α10 nAChRs by noncompetitive and competitive mechanisms, respectively, and with higher potency than the GABAAR and CaV2.2 channel.
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Affiliation(s)
- Han-Shen Tae
- Molecular Horizons/Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Marcelo O Ortells
- Facultad de Medicina, Universidad de Morón, and CONICET, Morón, Argentina
| | - Arsalan Yousuf
- Molecular Horizons/Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Sophia Q Xu
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Gustav Akk
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - David J Adams
- Molecular Horizons/Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Hugo R Arias
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, OK, USA
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Li X, Tae HS, Chen S, Yousuf A, Huang L, Zhang J, Jiang T, Adams DJ, Yu R. Dual Antagonism of α9α10 nAChR and GABA B Receptor-Coupled Ca V2.2 Channels by an Analgesic αO-Conotoxin Analogue. J Med Chem 2024; 67:971-987. [PMID: 38217860 DOI: 10.1021/acs.jmedchem.3c00979] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
Pain severely affects the physical and mental health of patients. The need to develop nonopioid analgesic drugs to meet medical demands is urgent. In this study, we designed a truncated analogue of αO-conotoxin, named GeX-2, based on disulfide-bond deletion and sequence truncation. GeX-2 retained the potency of its parent peptide at the human α9α10 nAChR and exhibited potent inhibitory activity at CaV2.2 channels via activation of the GABAB receptor (GABABR). Importantly, GeX-2 significantly alleviated pain in the rat model of chronic constriction injury. The dual inhibition of GeX-2 at both α9α10 nAChRs and CaV2.2 channels is speculated to synergistically mediate the potent analgesic effects. Results from site-directed mutagenesis assay and computational modeling suggest that GeX-2 preferentially interacts with the α10(+)α10(-) binding site of α9α10 nAChR and favorably binds to the top region of the GABABR2 subunit. The study offers vital insights into the molecular action mechanism of GeX-2, demonstrating its potential as a novel nonopioid analgesic.
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Affiliation(s)
- Xiao Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Shen Chen
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Arsalan Yousuf
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Linhong Huang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Jinghui Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Tao Jiang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
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Arias HR, Tae HS, Micheli L, Yousuf A, Manetti D, Romanelli MN, Ghelardini C, Adams DJ, Di Cesare Mannelli L. The Antinociceptive Activity of (E)-3-(thiophen-2-yl)- N -(p-tolyl)acrylamide in Mice Is Reduced by (E)-3-(furan-2-yl)- N -methyl- N -(p-tolyl)acrylamide Through Opposing Modulatory Mechanisms at the α7 Nicotinic Acetylcholine Receptor. Anesth Analg 2023; 137:691-701. [PMID: 37058425 PMCID: PMC10408732 DOI: 10.1213/ane.0000000000006461] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2023] [Indexed: 04/15/2023]
Abstract
BACKGROUND The primary objective of this study was to characterize the pharmacological and behavioral activity of 2 novel compounds, DM497 [(E)-3-(thiophen-2-yl)- N -(p-tolyl)acrylamide] and DM490 [(E)-3-(furan-2-yl)- N -methyl- N -(p-tolyl)acrylamide], structural derivatives of PAM-2, a positive allosteric modulator of the α7 nicotinic acetylcholine receptor (nAChR). METHODS A mouse model of oxaliplatin-induced neuropathic pain (2.4 mg/kg, 10 injections) was used to test the pain-relieving properties of DM497 and DM490. To assess possible mechanisms of action, the activity of these compounds was determined at heterologously expressed α7 and α9α10 nAChRs, and voltage-gated N-type calcium channel (Ca V 2.2) using electrophysiological techniques. RESULTS Cold plate tests indicated that 10 mg/kg DM497 was able to decrease neuropathic pain in mice induced by the chemotherapeutic agent oxaliplatin. In contrast, DM490 induced neither pro- nor antinociceptive activity but inhibited DM497's effect at equivalent dose (30 mg/kg). These effects are not a product of changes in motor coordination or locomotor activity. At α7 nAChRs, DM497 potentiated whereas DM490 inhibited its activity. In addition, DM490 antagonized the α9α10 nAChR with >8-fold higher potency than that for DM497. In contrast, DM497 and DM490 had minimal inhibitory activity at the Ca V 2.2 channel. Considering that DM497 did not increase the mouse exploratory activity, an indirect anxiolytic mechanism was not responsible for the observed antineuropathic effect. CONCLUSIONS The antinociceptive activity of DM497 and the concomitant inhibitory effect of DM490 are mediated by opposing modulatory mechanisms on the α7 nAChR, whereas the involvement of other possible nociception targets such as the α9α10 nAChR and Ca V 2.2 channel can be ruled out.
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Affiliation(s)
- Hugo R. Arias
- From the Department of Pharmacology and Physiology, College of Osteopathic Medicine, Oklahoma State University Center for Health Sciences, Tahlequah, Oklahoma
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales, Australiaand Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)
| | | | - Arsalan Yousuf
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales, Australiaand Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)
| | - Dina Manetti
- Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy
| | - Maria Novella Romanelli
- Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy
| | | | - David J. Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales, Australiaand Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)
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Wang S, Bartels P, Zhao C, Yousuf A, Liu Z, Yu S, Bony AR, Ma X, Dai Q, Sun T, Liu N, Yang M, Yu R, Du W, Adams DJ, Dai Q. A 4/8 Subtype α-Conotoxin Vt1.27 Inhibits N-Type Calcium Channels With Potent Anti-Allodynic Effect. Front Pharmacol 2022; 13:881732. [PMID: 35754473 PMCID: PMC9230573 DOI: 10.3389/fphar.2022.881732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/08/2022] [Indexed: 11/22/2022] Open
Abstract
A novel 4/8 subtype α-conotoxin, Vt1.27 (NCCMFHTCPIDYSRFNC-NH2), was identified from Conus vitulinus in the South China Sea by RACE methods. The peptide was synthesized and structurally characterized. Similar to other α-conotoxins that target neuronal nicotinic acetylcholine receptor (nAChR) subtypes, Vt1.27 inhibited the rat α3β2 nAChR subtype (IC50 = 1160 nM) and was inactive at voltage-gated sodium and potassium channels in rat sensory neurons. However, Vt1.27 inhibited high voltage-activated N-type (CaV2.2) calcium channels expressed in HEK293T cells with an IC50 of 398 nM. An alanine scan of the peptide showed that residues Phe5, Pro9, Ile10, and Ser13 contribute significantly to the inhibitory activity of Vt1.27. The molecular dockings indicate that Vt1.27 inhibits the transmembrane region of CaV2.2, which is different from that of ω-conotoxins. Furthermore, Vt1.27 exhibited potent anti-allodynic effect in rat partial sciatic nerve injury (PNL) and chronic constriction injury (CCI) pain models at 10 nmol/kg level with the intramuscular injection. The pain threshold elevation of Vt1.27 groups was higher than that of α-conotoxin Vc1.1 in CCI rat models. These findings expand our knowledge of targets of α-conotoxins and potentially provide a potent, anti-allodynic peptide for the treatment of neuropathic pain.
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Affiliation(s)
- Shuo Wang
- Beijing Institute of Biotechnology, Beijing, China
- Department of Pharmacy, PLA Rocket Force Characteristic Medical Center, Beijing, China
| | - Peter Bartels
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Cong Zhao
- Department of Chemistry, Renmin University of China, Beijing, China
| | - Arsalan Yousuf
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Zhuguo Liu
- Beijing Institute of Biotechnology, Beijing, China
| | - Shuo Yu
- Beijing Institute of Biotechnology, Beijing, China
| | - Anuja R. Bony
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Xiaoli Ma
- Beijing Institute of Biotechnology, Beijing, China
| | - Qin Dai
- Beijing Institute of Biotechnology, Beijing, China
| | - Ting Sun
- Beijing Institute of Biotechnology, Beijing, China
| | - Na Liu
- Beijing Institute of Biotechnology, Beijing, China
| | - Mengke Yang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Rilei Yu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Weihong Du
- Department of Chemistry, Renmin University of China, Beijing, China
- *Correspondence: Qiuyun Dai, ; David J. Adams, ; Weihong Du,
| | - David J. Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
- *Correspondence: Qiuyun Dai, ; David J. Adams, ; Weihong Du,
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing, China
- *Correspondence: Qiuyun Dai, ; David J. Adams, ; Weihong Du,
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Sachse M, Naito S, Oelschner C, Yousuf A, Bernhardt A, Reichenspurner H, Sill B. Mechanical Circulatory Support in Lung Transplant Recipients: Early and Long-Term Survival. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.1501] [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: 10/18/2022] Open
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Yousuf A, Wu X, Bony AR, Sadeghi M, Huang YH, Craik DJ, Adams DJ. ɑO-Conotoxin GeXIVA isomers modulate N-type calcium (Ca V 2.2) channels and inwardly-rectifying potassium (GIRK) channels via GABA B receptor activation. J Neurochem 2021; 160:154-171. [PMID: 34738241 DOI: 10.1111/jnc.15535] [Citation(s) in RCA: 6] [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: 07/23/2021] [Revised: 10/28/2021] [Accepted: 10/28/2021] [Indexed: 12/28/2022]
Abstract
αO-Conotoxin GeXIVA is a 28 amino acid peptide derived from the venom of the marine snail Conus generalis. The presence of four cysteine residues in the structure of GeXIVA allows it to have three different disulfide isomers, that is, the globular, ribbon or bead isomer. All three isomers are active at α9α10 nicotinic acetylcholine receptors, with the bead isomer, GeXIVA[1,2], being the most potent and exhibiting analgesic activity in animal models of neuropathic pain. The original report of GeXIVA activity failed to observe any effect of the isomers on high voltage-activated (HVA) calcium channel currents in rat dorsal root ganglion (DRG) neurons. In this study, we report, for the first time, the activity of globular GeXIVA[1,3] at G protein-coupled GABAB receptors (GABAB R) inhibiting HVA N-type calcium (Cav2.2) channels and reducing membrane excitability in mouse DRG neurons. The inhibition of HVA Ba2+ currents and neuroexcitability by GeXIVA[1,3] was partially reversed by the selective GABAB R antagonist CGP 55845. In transfected HEK293T cells co-expressing human GABAB R1 and R2 subunits and Cav2.2 channels, both GeXIVA[1,3] and GeXIVA[1,4] inhibited depolarization-activated Ba2+ currents mediated by Cav2.2 channels, whereas GeXIVA[1,2] had no effect. The effects of three cyclized GeXIVA[1,4] ribbon isomers were also tested, with cGeXIVA GAG being the most potent at human GABAB R-coupled Cav2.2 channels. Interestingly, globular GeXIVA[1,3] also reversibly potentiated inwardly-rectifying K+ currents mediated by human GIRK1/2 channels co-expressed with GABAB R in HEK293T cells. This study highlights GABAB R as a potentially important receptor target for the activity of αO-conotoxin GeXIVA to mediate analgesia.
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Affiliation(s)
- Arsalan Yousuf
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Xiaosa Wu
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Anuja R Bony
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Mahsa Sadeghi
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
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Yousuf A, Sadeghi M, Adams DJ. Venom-Derived Peptides Inhibiting Voltage-Gated Sodium and Calcium Channels in Mammalian Sensory Neurons. Ion Channels in Biophysics and Physiology 2021; 1349:3-19. [DOI: 10.1007/978-981-16-4254-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Arias HR, Ghelardini C, Lucarini E, Tae HS, Yousuf A, Marcovich I, Manetti D, Romanelli MN, Elgoyhen AB, Adams DJ, Di Cesare Mannelli L. ( E)-3-Furan-2-yl- N- p-tolyl-acrylamide and its Derivative DM489 Decrease Neuropathic Pain in Mice Predominantly by α7 Nicotinic Acetylcholine Receptor Potentiation. ACS Chem Neurosci 2020; 11:3603-3614. [PMID: 33073974 DOI: 10.1021/acschemneuro.0c00476] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The main objective of this study was to determine whether (E)-3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2) and its structural derivative DM489 produce anti-neuropathic pain activity using the streptozotocin (STZ)- and oxaliplatin-induced neuropathic pain animal models. To assess possible mechanisms of action, the pharmacological activity of these compounds was determined at α7 and α9α10 nicotinic acetylcholine receptors (nAChRs) and CaV2.2 channels expressed alone or coexpressed with G protein-coupled GABAB receptors. The animal results indicated that a single dose of 3 mg/kg PAM-2 or DM489 decreases STZ-induced neuropathic pain in mice, and chemotherapy-induced neuropathic pain is decreased by PAM-2 (3 mg/kg) and DM489 (10 mg/kg). The observed anti-neuropathic pain activity was inhibited by the α7-selective antagonist methyllycaconitine. The coadministration of oxaliplatin with an inactive dose (1 mg/kg) of PAM-2 decreased the development of neuropathic pain after 14, but not 7, days of cotreatment. The electrophysiological results indicated that PAM-2 potentiates human (h) and rat (r) α7 nAChRs with 2-7 times higher potency than that for hCaV2.2 channel inhibition and an even greater difference compared to that for rα9α10 nAChR inhibition. These results support the notion that α7 nAChR potentiation is likely the predominant molecular mechanism underlying the observed anti-nociceptive pain activity of these compounds.
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Affiliation(s)
- Hugo R. Arias
- Department of Pharmacology and Physiology, College of Osteopathic Medicine, Oklahoma State University Center for Health Sciences, Tahlequah, Oklahoma 74464, United States
| | | | | | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia
| | - Arsalan Yousuf
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia
| | | | | | | | | | - David J. Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia
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Arias HR, Tae HS, Micheli L, Yousuf A, Ghelardini C, Adams DJ, Di Cesare Mannelli L. Coronaridine congeners decrease neuropathic pain in mice and inhibit α9α10 nicotinic acetylcholine receptors and Ca V2.2 channels. Neuropharmacology 2020; 175:108194. [PMID: 32540451 DOI: 10.1016/j.neuropharm.2020.108194] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 12/24/2022]
Abstract
The primary aim of this study was to determine the anti-neuropathic activity of (±)-18-methoxycoronaridine [(±)-18-MC] and (+)-catharanthine in mice by using the oxaliplatin-induced neuropathic pain paradigm and cold plate test. The results showed that both coronaridine congeners induce anti-neuropathic pain activity at a dose of 72 mg/kg (per os), whereas a lower dose (36 mg/kg) of (+)-catharanthine decreased the progress of oxaliplatin-induced neuropathic pain. To determine the underlying molecular mechanism, electrophysiological recordings were performed on α9α10, α3β4, and α4β2 nAChRs as well as voltage-gated calcium (CaV2.2) channels modulated by G protein-coupled γ-aminobutyric acid type B receptors (GABABRs). The results showed that (±)-18-MC and (+)-catharanthine competitively inhibit α9α10 nAChRs with potencies higher than that at α3β4 and α4β2 nAChRs and directly block CaV2.2 channels without activating GABABRs. Considering the potency of the coronaridine congeners at Cav2.2 channels and α9α10 nAChRs, and the calculated brain concentration of (+)-catharanthine, it is plausible that the observed anti-neuropathic pain effects are mediated by peripheral and central mechanisms involving the inhibition of α9α10 nAChRs and/or CaV2.2 channels.
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Affiliation(s)
- Hugo R Arias
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, OK, USA.
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, 2522, Australia.
| | - Laura Micheli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, 50139, Florence, Italy
| | - Arsalan Yousuf
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Carla Ghelardini
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, 50139, Florence, Italy
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Lorenzo Di Cesare Mannelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, 50139, Florence, Italy
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Dekan Z, Sianati S, Yousuf A, Sutcliffe KJ, Gillis A, Mallet C, Singh P, Jin AH, Wang AM, Mohammadi SA, Stewart M, Ratnayake R, Fontaine F, Lacey E, Piggott AM, Du YP, Canals M, Sessions RB, Kelly E, Capon RJ, Alewood PF, Christie MJ. A tetrapeptide class of biased analgesics from an Australian fungus targets the µ-opioid receptor. Proc Natl Acad Sci U S A 2019; 116:22353-22358. [PMID: 31611414 PMCID: PMC6825270 DOI: 10.1073/pnas.1908662116] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
An Australian estuarine isolate of Penicillium sp. MST-MF667 yielded 3 tetrapeptides named the bilaids with an unusual alternating LDLD chirality. Given their resemblance to known short peptide opioid agonists, we elucidated that they were weak (Ki low micromolar) μ-opioid agonists, which led to the design of bilorphin, a potent and selective μ-opioid receptor (MOPr) agonist (Ki 1.1 nM). In sharp contrast to all-natural product opioid peptides that efficaciously recruit β-arrestin, bilorphin is G protein biased, weakly phosphorylating the MOPr and marginally recruiting β-arrestin, with no receptor internalization. Importantly, bilorphin exhibits a similar G protein bias to oliceridine, a small nonpeptide with improved overdose safety. Molecular dynamics simulations of bilorphin and the strongly arrestin-biased endomorphin-2 with the MOPr indicate distinct receptor interactions and receptor conformations that could underlie their large differences in bias. Whereas bilorphin is systemically inactive, a glycosylated analog, bilactorphin, is orally active with similar in vivo potency to morphine. Bilorphin is both a unique molecular tool that enhances understanding of MOPr biased signaling and a promising lead in the development of next generation analgesics.
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Affiliation(s)
- Zoltan Dekan
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Setareh Sianati
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Arsalan Yousuf
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Katy J Sutcliffe
- Schools of Physiology, Pharmacology and Neuroscience, and Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, United Kingdom
| | - Alexander Gillis
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Christophe Mallet
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Paramjit Singh
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Aihua H Jin
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Anna M Wang
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Sarasa A Mohammadi
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Michael Stewart
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Ranjala Ratnayake
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Frank Fontaine
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Ernest Lacey
- Microbial Screening Technologies Pty. Ltd., Smithfield, NSW, 2164, Australia
| | - Andrew M Piggott
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Yan P Du
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia
| | - Meritxell Canals
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, 3052 Parkville, Australia
| | - Richard B Sessions
- Schools of Physiology, Pharmacology and Neuroscience, and Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, United Kingdom
| | - Eamonn Kelly
- Schools of Physiology, Pharmacology and Neuroscience, and Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, United Kingdom
| | - Robert J Capon
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia;
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia;
| | - MacDonald J Christie
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, NSW 2006, Australia;
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Mostyn SN, Rawling T, Mohammadi S, Shimmon S, Frangos ZJ, Sarker S, Yousuf A, Vetter I, Ryan RM, Christie MJ, Vandenberg RJ. Development of an N-Acyl Amino Acid That Selectively Inhibits the Glycine Transporter 2 To Produce Analgesia in a Rat Model of Chronic Pain. J Med Chem 2019; 62:2466-2484. [PMID: 30714733 DOI: 10.1021/acs.jmedchem.8b01775] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inhibitors that target the glycine transporter 2, GlyT2, show promise as analgesics, but may be limited by their toxicity through complete or irreversible binding. Acyl-glycine inhibitors, however, are selective for GlyT2 and have been shown to provide analgesia in animal models of pain with minimal side effects, but are comparatively weak GlyT2 inhibitors. Here, we modify the simple acyl-glycine by synthesizing lipid analogues with a range of amino acid head groups in both l- and d-configurations, to produce nanomolar affinity, selective GlyT2 inhibitors. The potent inhibitor oleoyl-d-lysine (33) is also resistant to degradation in both human and rat plasma and liver microsomes, and is rapidly absorbed following an intraperitoneal injection to rats and readily crosses the blood-brain barrier. We demonstrate that 33 provides greater analgesia at lower doses, and does not possess the severe side effects of the very slowly reversible GlyT2 inhibitor, ORG25543 (2).
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Affiliation(s)
- Shannon N Mostyn
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Tristan Rawling
- School of Mathematical and Physical Sciences, Faculty of Science , The University of Technology Sydney , Sydney , NSW 2007 , Australia
| | - Sarasa Mohammadi
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Susan Shimmon
- School of Mathematical and Physical Sciences, Faculty of Science , The University of Technology Sydney , Sydney , NSW 2007 , Australia
| | - Zachary J Frangos
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Subhodeep Sarker
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Arsalan Yousuf
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Irina Vetter
- Institute for Molecular Bioscience & School of Pharmacy , The University of Queensland , Brisbane , Qld 4072 , Australia
| | - Renae M Ryan
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Macdonald J Christie
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
| | - Robert J Vandenberg
- Discipline of Pharmacology, School of Medical Sciences , University of Sydney , Sydney , NSW 2006 , Australia
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Miess E, Gondin AB, Yousuf A, Steinborn R, Mösslein N, Yang Y, Göldner M, Ruland JG, Bünemann M, Krasel C, Christie MJ, Halls ML, Schulz S, Canals M. Multisite phosphorylation is required for sustained interaction with GRKs and arrestins during rapid μ-opioid receptor desensitization. Sci Signal 2018; 11:11/539/eaas9609. [PMID: 30018083 DOI: 10.1126/scisignal.aas9609] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
G protein receptor kinases (GRKs) and β-arrestins are key regulators of μ-opioid receptor (MOR) signaling and trafficking. We have previously shown that high-efficacy opioids such as DAMGO stimulate a GRK2/3-mediated multisite phosphorylation of conserved C-terminal tail serine and threonine residues, which facilitates internalization of the receptor. In contrast, morphine-induced phosphorylation of MOR is limited to Ser375 and is not sufficient to drive substantial receptor internalization. We report how specific multisite phosphorylation controlled the dynamics of GRK and β-arrestin interactions with MOR and show how such phosphorylation mediated receptor desensitization. We showed that GRK2/3 was recruited more quickly than was β-arrestin to a DAMGO-activated MOR. β-Arrestin recruitment required GRK2 activity and MOR phosphorylation, but GRK recruitment also depended on the phosphorylation sites in the C-terminal tail, specifically four serine and threonine residues within the 370TREHPSTANT379 motif. Our results also suggested that other residues outside this motif participated in the initial and transient recruitment of GRK and β-arrestins. We identified two components of high-efficacy agonist desensitization of MOR: a sustained component, which required GRK2-mediated phosphorylation and a potential soluble factor, and a rapid component, which was likely mediated by GRK2 but independent of receptor phosphorylation. Elucidating these complex receptor-effector interactions represents an important step toward a mechanistic understanding of MOR desensitization that leads to the development of tolerance and dependence.
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Affiliation(s)
- Elke Miess
- Department of Pharmacology and Toxicology, Jena University Hospital-Friedrich Schiller University Jena, D-07747 Jena, Germany
| | - Arisbel B Gondin
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria 3052, Australia
| | - Arsalan Yousuf
- Discipline of Pharmacology, University of Sydney, New South Wales 2006, Australia
| | - Ralph Steinborn
- Department of Pharmacology and Toxicology, Jena University Hospital-Friedrich Schiller University Jena, D-07747 Jena, Germany
| | - Nadja Mösslein
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Yunshi Yang
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Martin Göldner
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Julia G Ruland
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Moritz Bünemann
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Cornelius Krasel
- Department of Pharmacology and Toxicology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - MacDonald J Christie
- Discipline of Pharmacology, University of Sydney, New South Wales 2006, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria 3052, Australia
| | - Stefan Schulz
- Department of Pharmacology and Toxicology, Jena University Hospital-Friedrich Schiller University Jena, D-07747 Jena, Germany.
| | - Meritxell Canals
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria 3052, Australia.
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Hallifax RJ, Yousuf A, Jones HE, Corcoran JP, Psallidas I, Rahman NM. Effectiveness of chemical pleurodesis in spontaneous pneumothorax recurrence prevention: a systematic review. Thorax 2016; 72:1121-1131. [PMID: 27803156 PMCID: PMC5738542 DOI: 10.1136/thoraxjnl-2015-207967] [Citation(s) in RCA: 54] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 08/02/2016] [Accepted: 08/15/2016] [Indexed: 11/23/2022]
Abstract
Objectives Spontaneous pneumothorax is a common pathology. International guidelines suggest pleurodesis for non-resolving air leak or recurrence prevention at second occurrence. This study comprehensively reviews the existing literature regarding chemical pleurodesis efficacy. Design We systematically reviewed the literature to identify relevant randomised controlled trials (RCTs), case–control studies and case series. We described the findings of these studies and tabulated relative recurrence rates or ORs (in studies with control groups). Meta-analysis was not performed due to substantial clinical heterogeneity. Results Of 560 abstracts identified by our search strategy, 50 were included in our systematic review following screening. Recurrence rates in patients with chest tube drainage only were between 26.1% and 50.1%. Thoracoscopic talc poudrage (four studies (n=249)) provided recurrence rates of between 2.5% and 10.2% with the only RCT suggesting an OR of 0.10 compared with drainage alone. In comparison, talc administration during video-assisted thoracic surgery (VATS) from eight studies (n=2324) recurrence was between 0.0% and 3.2%, but the RCT did not demonstrate a significant difference compared with bleb/bullectomy alone. Minocycline appears similarly effective post-VATS (recurrence rates 0.0–2.9%). Prolonged air leak and recurrence prevention using tetracycline via chest drain (n=726) is likely to provide recurrence rates between 13.0% and 33.3% and autologous blood patch pleurodesis (n=270) between 15.6% and 18.2%. Conclusions Chemical pleurodesis postsurgical treatment or via thoracoscopy appears to be most effective. Evidence for definitive success rates of each agent is limited by the small number of randomised trials or other comparative studies.
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Affiliation(s)
- R J Hallifax
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - A Yousuf
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - H E Jones
- Faculty of Health Sciences, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - J P Corcoran
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - I Psallidas
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - N M Rahman
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
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Salzer I, Gantumur E, Yousuf A, Boehm S. Control of sensory neuron excitability by serotonin involves 5HT2C receptors and Ca(2+)-activated chloride channels. Neuropharmacology 2016; 110:277-286. [PMID: 27511837 PMCID: PMC6192515 DOI: 10.1016/j.neuropharm.2016.08.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/02/2016] [Accepted: 08/06/2016] [Indexed: 01/11/2023]
Abstract
Serotonin (5HT) is a constituent of the so-called “inflammatory soup” that sensitizes nociceptors during inflammation. Nevertheless, receptors and signaling mechanisms that mediate an excitation of dorsal root ganglion (DRG) neurons by 5HT remained controversial. Therefore, capsaicin-sensitive nociceptive neurons dissociated from rat DRGs were used to investigate effects of 5HT on membrane excitability and currents through ligand- as well as voltage-gated ion channels. In 58% of the neurons tested, 5HT increased action potential firing, an effect that was abolished by the 5HT2 receptor antagonist ritanserin, but not by the 5HT3 antagonist tropisetron. Unlike other algogenic mediators, such as PGE2 and bradykinin, 5HT did not affect currents through TTX-resistant Na+ channels or Kv7 K+ channels. In all neurons investigated, 5HT potentiated capsaicin-evoked currents through TRPV1 channels, an effect that was attenuated by antagonists at 5HT2A (4 F 4 PP), 5HT2B (SB 204741), as well as 5HT2C (RS 102221) receptors. 5HT triggered slowly arising inward Cl− currents in 53% of the neurons. This effect was antagonized by the 5HT2C receptor blocker only, and the current was prevented by an inhibitor of Ca2+-activated chloride channels (CaCC). The 5HT-induced increase in action potential firing was also abolished by this CaCC blocker and by the TRPV1 inhibitor capsazepine. Amongst the subtype selective 5HT2 antagonists, only RS 102221 (5HT2C-selectively) counteracted the rise in action potential firing elicited by 5HT. These results show that 5HT excites DRG neurons mainly via 5HT2C receptors which concomitantly mediate a sensitization of TRPV1 channels and an opening of CaCCs.
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Affiliation(s)
- Isabella Salzer
- Centre for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, A-1090 Vienna, Austria
| | - Enkhbileg Gantumur
- Centre for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, A-1090 Vienna, Austria
| | - Arsalan Yousuf
- Centre for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, A-1090 Vienna, Austria
| | - Stefan Boehm
- Centre for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, A-1090 Vienna, Austria.
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Yousuf A, Satkunaratnam A, Frecker H, Shore E. O-GYN-MD-032 The Development of a Retroperitoneal Dissection Model. Journal of Obstetrics and Gynaecology Canada 2016. [DOI: 10.1016/j.jogc.2016.04.078] [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]
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17
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Hallifax RJ, Yousuf A, Corcoran JP, Psallidas I, Rahman NM. P179 The Effectiveness of Chemical Pleurodesis Agents in Spontaneous Pneumothorax: A Systematic Review: Abstract P179 Table 1. Thorax 2015. [DOI: 10.1136/thoraxjnl-2015-207770.316] [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: 11/04/2022]
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Nagaraj A, Vishnani P, Yousuf A, Ganta S, Singh K, Acharya S. Perception of Dentists about Caries-risk Assessment tools in Jaipur, India: A Cross-sectional Study. J Int Oral Health 2015; 7:77-81. [PMID: 26464544 PMCID: PMC4588795] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Caries risk assessment (CRA) is an essential element of contemporary clinical care for infants, children, and adolescents. CRA tools aid in the detection as well as documentation of caries risk predictors and let the health care professionals to be more active in identifying and referring high-risk patients for proper treatment and required prevention. The aim of the study was to assess the information-seeking behavior of dental practitioners of Jaipur regarding CRA tools. MATERIALS AND METHODS A cross-sectional questionnaire-based survey was conducted among the dental practitioners of Jaipur city. A 17-itemed questionnaire was personally administered to 373 dental practitioners of Jaipur and their knowledge was assessed based on the questions about CRA tools and Cariogram. The data were analyzed using Chi-square test. RESULTS Around 80.5% of the practitioners were aware of CRA tools among which only one-fourth were practicing CRA. Significant correlation of qualification, specialty, and years of practice was found with knowledge of CRA tools, practice of CRA and preventive treatment and attitude toward risk assessment. CONCLUSIONS A substantial percentage of dentists did not practice CRA, but were interested in receiving more education about CRA and its tools.
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Affiliation(s)
- A Nagaraj
- Professor and Head, Department of Public Health Dentistry, Jaipur Dental College, Jaipur, Rajasthan, India
| | - P Vishnani
- Post Graduate, Department of Public Health Dentistry, Jaipur Dental College, Jaipur, Rajasthan, India
| | - A Yousuf
- Registrar, Department of Public Health Dentistry, Government Dental College, Shireen Bagh, Srinagar, Jammu and Kashmir, India,Correspondence: Dr. Yousuf A. Department of Public Health Dentistry, Government Dental College, Shireen Bagh, Srinagar - 190 010, Jammu and Kashmir India.
| | - S Ganta
- Assistant Professor, Department of Public Health Dentistry, Jaipur Dental College, Jaipur, Rajasthan, India
| | - K Singh
- Senior Lecturer, Department of Public Health Dentistry, The Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, India
| | - S Acharya
- Post Graduate, Department of Public Health Dentistry, Jaipur Dental College, Jaipur, Rajasthan, India
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Yousuf A, Miess E, Sianati S, Du YP, Schulz S, Christie MJ. Role of Phosphorylation Sites in Desensitization of µ-Opioid Receptor. Mol Pharmacol 2015; 88:825-35. [PMID: 25969388 DOI: 10.1124/mol.115.098244] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 05/12/2015] [Indexed: 11/22/2022] Open
Abstract
Phosphorylation of residues in the C-terminal tail of the µ-opioid receptor (MOPr) is thought to be a key step in desensitization and internalization. Phosphorylation of C-terminal S/T residues is required for internalization (Just et al., 2013), but its role in desensitization is unknown. This study examined the influence of C-terminal phosphorylation sites on rapid desensitization of MOPr. Wild-type MOPr, a 3S/T-A mutant (S363A, T370A, S375A) that maintains internalization, 6S/T-A (S363A, T370A, S375A, T376A, T379A, T383A) and 11S/T-A (all C-terminal S/T residues mutated) mutants not internalized by MOPr agonists were stably expressed in AtT20 cells. Perforated patch-clamp recordings of MOPr-mediated activation of G-protein-activated inwardly rectifying potassium channel (Kir3.X) (GIRK) conductance by submaximal concentrations of Met(5)-enkephalin (ME) and somatostatin (SST; coupling to native SST receptor [SSTR]) were used to examine desensitization induced by exposure to ME and morphine for 5 minutes at 37°C. The rates of ME- and morphine-induced desensitization did not correlate with phosphorylation using phosphorylation site-specific antibodies. ME-induced MOPr desensitization and resensitization did not differ from wild-type for 3S/T-A and 6S/T-A but was abolished in 11S/T-A. Morphine-induced desensitization was unaffected in all three mutants, as was heterologous desensitization of SSTR. Morphine-induced desensitization (but not ME) was reduced by protein kinase C inhibition in wild-type MOPr and abolished in the 11S/T-A mutant, as was heterologous desensitization. These findings establish that MOPr desensitization can occur independently of S/T phosphorylation and internalization; however, C-terminal phosphorylation is necessary for some forms of desensitization because mutation of all C-terminal sites (11S/T-A) abolishes desensitization induced by ME.
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Affiliation(s)
- Arsalan Yousuf
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
| | - Elke Miess
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
| | - Setareh Sianati
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
| | - Yan-Ping Du
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
| | - Stefan Schulz
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
| | - MacDonald J Christie
- Discipline of Pharmacology, University of Sydney, New South Wales, Sydney, Australia (A.Y., S.Si., Y.-P.D., M.J.C.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (E.M., S.Sc.)
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Yousuf A, Hussain A. SU-E-T-100: Designing a QA Tool for Enhance Dynamic Wedges Based On Dynalog Files. Med Phys 2014. [DOI: 10.1118/1.4888430] [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: 11/07/2022] Open
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Rabiul IGM, Gias UM, Mahfuzur RM, Yousuf A. Caffeine and total polyphenol contents of market tea cultivated and processed in Bangladesh. Malays J Nutr 2013; 19:143-147. [PMID: 24800393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE The aim of this study was to determine the contents of caffeine and total polyphenol in six brands of market tea cultivated and processed in Bangladesh. METHODS Caffeine and polyphenol contents were determined by solvent extraction (AACC) and the International Organisation for Standardisation Method (ISO) 14502-1 respectively. RESULTS Caffeine contents of the different tea samples ranged between 0.99 +/- 0.17% to 2.08 +/- 0.16% (g/100g materials), while that of total polyphenol was from 36.90 +/- 1.39% to 17.29 +/- 2.30% of gallic acid equivalents (GAE). The order of caffeine concentration in tea samples was found as follows: Organic Black Tea > Taaza Tea > Organic Green Tea > Magnolia Tea > Organic Zinger Tea > Organic Tulsi Tea. The polyphenol concentration in the tea samples was highest in Organic Green Tea followed by Taaza Tea and the rest as follows: Magnolia Tea > Organic Black Tea > Organic Zinger Tea > Organic Tulsi Tea. An indicative difference in amounts of caffeine and polyphenols for different tea brand samples is seen in this study. CONCLUSION This systematic screening provides information to producers as well as consumers on the quantities of caffeine and polyphenols in commercial tea available in the markets of Bangladesh.
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Shahi N, No author NA, Yousuf A, Rather M, Yaseen F. First report of blood parasites in fishes from Kashmir and their effect on the haematological profile. Open Vet J 2013. [DOI: 10.5455/ovj.2013.v3.i2.p89] [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: 11/06/2022] Open
Abstract
Cyprinus carpio communis Linnaeus, Carassius carassius Linnaeus, Schizothorax curvifrons Heckel and Triplophysa marmorata species of fishes were captured from Anchar Lake and river Jhelum of Kashmir Himalaya for hematological and parasitological analysis. During the investigation haemoflagellates from the genus Babesiosoma and Trypanosoma were recorded in the blood smears. Trypanosomes were present in all the species except C. carpio, whereas Babesiosoma were only found in T. marmorata. Haematological analysis revealed a significant (p<0.01) reduction in red blood cell count in the fishes infected with Babesiosoma and Trypanosoma. A significant decrease (p<0.05) was recorded in haemoglobin value and packed cell volume in the infected fishes in comparison to the non-infected fishes.
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Klinger F, Geier P, Dorostkar MM, Chandaka GK, Yousuf A, Salzer I, Kubista H, Boehm S. Concomitant facilitation of GABAA receptors and KV7 channels by the non-opioid analgesic flupirtine. Br J Pharmacol 2012; 166:1631-42. [PMID: 22188423 DOI: 10.1111/j.1476-5381.2011.01821.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Flupirtine is a non-opioid analgesic that has been in clinical use for more than 20 years. It is characterized as a selective neuronal potassium channel opener (SNEPCO). Nevertheless, its mechanisms of action remain controversial and are the purpose of this study. EXPERIMENTAL APPROACH Effects of flupirtine on native and recombinant voltage- and ligand-gated ion channels were explored in patch-clamp experiments using the following experimental systems: recombinant K(IR)3 and K(V)7 channels and α3β4 nicotinic acetylcholine receptors expressed in tsA 201 cells; native voltage-gated Na(+), Ca(2+), inward rectifier K(+), K(V)7 K(+), and TRPV1 channels, as well as GABA(A), glycine, and ionotropic glutamate receptors expressed in rat dorsal root ganglion, dorsal horn and hippocampal neurons. KEY RESULTS Therapeutic flupirtine concentrations (≤10 µM) did not affect voltage-gated Na(+) or Ca(2+) channels, inward rectifier K(+) channels, nicotinic acetylcholine receptors, glycine or ionotropic glutamate receptors. Flupirtine shifted the gating of K(V)7 K(+) channels to more negative potentials and the gating of GABA(A) receptors to lower GABA concentrations. These latter effects were more pronounced in dorsal root ganglion and dorsal horn neurons than in hippocampal neurons. In dorsal root ganglion and dorsal horn neurons, the facilitatory effect of therapeutic flupirtine concentrations on K(V)7 channels and GABA(A) receptors was comparable, whereas in hippocampal neurons the effects on K(V)7 channels were more pronounced. CONCLUSIONS AND IMPLICATIONS These results indicate that flupirtine exerts its analgesic action by acting on both GABA(A) receptors and K(V)7 channels.
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Affiliation(s)
- Felicia Klinger
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Austria
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Yousuf A, Malik M, Shamas IU, Beigh Z, Kumari S, Pampori PRA. Bacteriological Profile Of Ear Discharge And Their Antibiotic Sensitivity In Chronic Suppurative Otitis Media In Kashmir,India. Bangladesh J Med Sci 2012. [DOI: 10.3329/bjms.v11i3.11731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The objective of the study was to study the microflora and the antibiograms of patients with chronic suppurative otitis media (CSOM) in Kashmir,in order to provide a guidelines for making a protocol for empirical antibiotic therapy. Study design:Prospective study Material and methods: This study was conducted on OPD basis in Department of Ear, Nose and Throat and HNS Government medical college Srinagar kashmir from july 2010 to june 1011 and one hundred twenty five(125) patients with unilateral or bilateral active chronic suppurative otitis media were prospectively studied.They had chronic ear discharge and had not received antibiotics for the previous five days. Swabs were taken from discharging ear's and sent to microbiological section of hospital were culture for bacteria was done Antibiotic sensitivity testing was done with standard antibiotic discs using Kirby-bauer disk diffusion method.4 Results:From the Clinical specimens off the 125 patients microbiological culture was positive in 110 specimens. The most common causal organisms isolated were Staphylococcus aureus (48%) including 8% of methcillin resistant staph aureus and Pseudomonas aeruginosa (16%) followed by coagulase negative.Antibiotic sensitivities of staph aureus (other than MRSA) showed that 72% isolates were sensitivity to gentamicin,55% to ciprofloxacin followed by 36% to cephalosporins (cetazidime,ceftriaxone) .For pseudomonas aeruginosa 72% isolates were sensitive to piperacillin/tazobactum 48% to ciprofloxacin and 32% to ceftazidime/ceftriaxone. Of the three antibiotics commonly available as topical eardrops,ciprofloxacin and gentamicin has the highest susceptibility rate. DOI: http://dx.doi.org/10.3329/bjms.v11i3.11731 Bangladesh Journal of Medical Science Vol. 11 No. 03 July12
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Yousuf A, Klinger F, Schicker K, Boehm S. Nucleotides control the excitability of sensory neurons via two P2Y receptors and a bifurcated signaling cascade. Pain 2011; 152:1899-1908. [PMID: 21600693 PMCID: PMC3144389 DOI: 10.1016/j.pain.2011.04.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/03/2011] [Accepted: 04/11/2011] [Indexed: 01/04/2023]
Abstract
Nucleotides contribute to the sensation of acute and chronic pain, but it remained enigmatic which G protein-coupled nucleotide (P2Y) receptors and associated signaling cascades are involved. To resolve this issue, nucleotides were applied to dorsal root ganglion neurons under current- and voltage-clamp. Adenosine triphosphate (ATP), adenosine diphosphate (ADP), and uridine triphosphate (UTP), but not uridine diphosphate (UDP), depolarized the neurons and enhanced action potential firing in response to current injections. The P2Y2 receptor preferring agonist 2-thio-UTP was equipotent to UTP in eliciting these effects. The selective P2Y1 receptor antagonist MRS2179 largely attenuated the excitatory effects of ADP, but left those of 2-thio-UTP unaltered. Thus, the excitatory effects of the nucleotides were mediated by 2 different P2Y receptors, P2Y1 and P2Y2. Activation of each of these 2 receptors by either ADP or 2-thio-UTP inhibited currents through KV7 channels, on one hand, and facilitated currents through TRPV1 channels, on the other hand. Both effects were abolished by inhibitors of phospholipase C or Ca2+-ATPase and by chelation of intracellular Ca2+. The facilitation of TRPV1, but not the inhibition KV7 channels, was prevented by a protein kinase C inhibitor. Simultaneous blockage of KV7 channels and of TRPV1 channels prevented nucleotide-induced membrane depolarization and action potential firing. Thus, P2Y1 and P2Y2 receptors mediate an excitation of dorsal root ganglion neurons by nucleotides through the inhibition of KV7 channels and the facilitation of TRPV1 channels via a common bifurcated signaling pathway relying on an increase in intracellular Ca2+ and an activation of protein kinase C, respectively.
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Affiliation(s)
- Arsalan Yousuf
- Centre for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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Wasay M, Rizvi F, Azeemuddin M, Yousuf A, Fredrikson S. Incidental MRI lesions suggestive of multiple sclerosis in asymptomatic patients in Karachi, Pakistan. J Neurol Neurosurg Psychiatry 2011; 82:83-5. [PMID: 20971756 DOI: 10.1136/jnnp.2009.180000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [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: 11/04/2022]
Abstract
The objective of this study was to identify asymptomatic patients with brain MRI lesions suggestive of multiple sclerosis (MS) in a low-prevalence area of Pakistan. Brain MRIs for 864 patients were reviewed at the Aga Khan University (Karachi, Pakistan) during an 8-month period of 2006 and 2007 to identify patients with lesions suggestive of MS. The lesions were characterised based on modified Barkhof criteria. Six (two females) (0.7%) of 864 patients fulfilled brain MRI criteria suggestive of MS. The mean number of MRI lesions (total lesions on T2) were 9 (range 5-14). Although Pakistan is considered a low-prevalence area for MS, 0.7% of brain MRI scans in patients without clinical MS symptoms showed lesions fulfilling brain MRI criteria of MS.
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Affiliation(s)
- M Wasay
- Department of Neurology, Aga Khan University, Karachi, Pakistan.
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Yousuf A, Boehm S. Nucleotides excite sensory neurons via two P2Y receptors and a dual signaling cascade. BMC Pharmacol 2009. [PMCID: PMC2778886 DOI: 10.1186/1471-2210-9-s2-a17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Yousuf A, Hossain M, Nakamura Y, Yamada Y, Kinoshita J, Matsumoto K. Removal of gingival melanin pigmentation with the semiconductor diode laser: a case report. J Clin Laser Med Surg 2000; 18:263-6. [PMID: 11572242 DOI: 10.1089/clm.2000.18.263] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This investigation was performed to evaluate the possibility of the removal of canine gingival melanin pigmentation with the semiconductor diode (SCD) laser in vivo. SUMMARY BACKGROUND DATA Recently, a semiconductor laser, which can ablate soft tissue, has been developed. It is already used in dentistry as well as in medicine. METHODS The SCD laser was irradiated on the pigmented area of canine gingival surface with the irradiation output of 3W. The effect of the SCD laser irradiation was evaluated at the two intervals: immediately after irradiation and at 3 weeks following irradiation. In addition, histological examination was performed before irradiation and at the same intervals from the biopsies (4 microm) of unlased and lased areas. RESULTS The SCD laser was effective in removing melanin pigmentation. In histological examination, neither inflammatory cell nor any tissue damage was observed with hematoxylin-eosin staining. At 3 weeks, there was a continuous healing process with the proliferation of squamous epithelial cells. CONCLUSIONS SCD laser irradiation can be considered an alternative procedure for removal of melanin pigmentation.
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Affiliation(s)
- A Yousuf
- Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan
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Abstract
Two cases of jejunal strictures caused by Histoplasma capsulatum in AIDS patients are presented. Both patients were intravenous drug abusers. One patient, who was being treated for Pneumocystis carnii pneumonia, presented with jejunal perforation and the other presented with lower gastrointestinal bleeding and intestinal obstruction. On exploration, both patients were found to have jejunal strictures; one had intestinal perforation, and the other had intestinal obstruction with ulcers and strictures resulting in gastrointestinal bleeding. In areas where it is endemic, histoplasmosis is rarely disseminated. Dissemination is most commonly seen in immunosuppressed patients. Dissemination and extrapulmonary histoplasmosis is now included in the case definition of AIDS.
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Affiliation(s)
- M A Gumbs
- Department of Surgery, Bronx-Lebanon Hospital Center, Bronx, New York, USA
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Rogers J, Yousuf A, Kleinhaus S. Laparoscopic accessory splenectomy in recurrent chronic immune thrombocytopenic purpura. Surg Laparosc Endosc Percutan Tech 1997; 7:83-5. [PMID: 9109231] [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: 02/04/2023]
Abstract
Splenectomy is the definitive treatment for most cases of idiopathic thrombocytopenic purpura (ITP). We present the case of a patient who was discovered to have ITP at age 5 and was treated medically for 3 years with decreasing response to medication. At age 8, he underwent splenectomy, after which the platelet count stabilized at approximately 200,000/mm3. Two years later he again had symptoms of thrombocytopenia and was treated medically with moderate success. At age 12, during hospitalization for bleeding, his liver/spleen scan gave negative results. Symptoms persisted, and when the patient was 13 a second scan found two small areas of uptake in the area of the splenic bed suggestive of secondary accessory splenic activity. The platelet count at that time was 6,000/mm3. Laparoscopy was performed, and after careful dissection of the left-upper quadrant, two globular masses, the larger of which was 3 x 2 x 2 cm, were removed without incident. The latest platelet count, 3 months after laparoscopic secondary accessory splenectomy, was 169,000/mm3, and a follow-up scan shows no uptake in the area of the spleen.
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Affiliation(s)
- J Rogers
- Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, New York, USA
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Gardezi SA, Chaudhry AM, Sial GA, Ahmad I, Yousuf A, Rashid M, Siddique S, Gardezi SJ. Sutureless skin closure: a comparative study with conventional stitching. J PAK MED ASSOC 1985; 35:323-6. [PMID: 3935817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Gardezi SA, Chaudhry AM, Sial GA, Ahmad I, Yousuf A. Minocycline HCL in urinary tract infection - a clinical trial. J PAK MED ASSOC 1983; 33:294-8. [PMID: 6418928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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