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Voelker TL, Del Villar SG, Westhoff M, Costa AD, Coleman AM, Hell JW, Horne MC, Dickson EJ, Dixon RE. Acute phosphatidylinositol 4,5 bisphosphate depletion destabilizes sarcolemmal expression of cardiac L-type Ca 2+ channel Ca V1.2. Proc Natl Acad Sci U S A 2023; 120:e2221242120. [PMID: 36976770 PMCID: PMC10083594 DOI: 10.1073/pnas.2221242120] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
CaV1.2 channels are critical players in cardiac excitation-contraction coupling, yet we do not understand how they are affected by an important therapeutic target of heart failure drugs and regulator of blood pressure, angiotensin II. Signaling through Gq-coupled AT1 receptors, angiotensin II triggers a decrease in PIP2, a phosphoinositide component of the plasma membrane (PM) and known regulator of many ion channels. PIP2 depletion suppresses CaV1.2 currents in heterologous expression systems but the mechanism of this regulation and whether a similar phenomenon occurs in cardiomyocytes is unknown. Previous studies have shown that CaV1.2 currents are also suppressed by angiotensin II. We hypothesized that these two observations are linked and that PIP2 stabilizes CaV1.2 expression at the PM and angiotensin II depresses cardiac excitability by stimulating PIP2 depletion and destabilization of CaV1.2 expression. We tested this hypothesis and report that CaV1.2 channels in tsA201 cells are destabilized after AT1 receptor-triggered PIP2 depletion, leading to their dynamin-dependent endocytosis. Likewise, in cardiomyocytes, angiotensin II decreased t-tubular CaV1.2 expression and cluster size by inducing their dynamic removal from the sarcolemma. These effects were abrogated by PIP2 supplementation. Functional data revealed acute angiotensin II reduced CaV1.2 currents and Ca2+ transient amplitudes thus diminishing excitation-contraction coupling. Finally, mass spectrometry results indicated whole-heart levels of PIP2 are decreased by acute angiotensin II treatment. Based on these observations, we propose a model wherein PIP2 stabilizes CaV1.2 membrane lifetimes, and angiotensin II-induced PIP2 depletion destabilizes sarcolemmal CaV1.2, triggering their removal, and the acute reduction of CaV1.2 currents and contractility.
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Affiliation(s)
- Taylor L Voelker
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Silvia G Del Villar
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Maartje Westhoff
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Alexandre D Costa
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Andrea M Coleman
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Johannes W Hell
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Mary C Horne
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
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2
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Bartels P, Salveson I, Coleman AM, Anderson DE, Jeng G, Estrada-Tobar ZM, Man KNM, Yu Q, Kuzmenkina E, Nieves-Cintron M, Navedo MF, Horne MC, Hell JW, Ames JB. Half-calcified calmodulin promotes basal activity and inactivation of the L-type calcium channel Ca V1.2. J Biol Chem 2022; 298:102701. [PMID: 36395884 PMCID: PMC9764201 DOI: 10.1016/j.jbc.2022.102701] [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: 07/11/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022] Open
Abstract
The L-type Ca2+ channel CaV1.2 controls gene expression, cardiac contraction, and neuronal activity. Calmodulin (CaM) governs CaV1.2 open probability (Po) and Ca2+-dependent inactivation (CDI) but the mechanisms remain unclear. Here, we present electrophysiological data that identify a half Ca2+-saturated CaM species (Ca2/CaM) with Ca2+ bound solely at the third and fourth EF-hands (EF3 and EF4) under resting Ca2+ concentrations (50-100 nM) that constitutively preassociates with CaV1.2 to promote Po and CDI. We also present an NMR structure of a complex between the CaV1.2 IQ motif (residues 1644-1665) and Ca2/CaM12', a calmodulin mutant in which Ca2+ binding to EF1 and EF2 is completely disabled. We found that the CaM12' N-lobe does not interact with the IQ motif. The CaM12' C-lobe bound two Ca2+ ions and formed close contacts with IQ residues I1654 and Y1657. I1654A and Y1657D mutations impaired CaM binding, CDI, and Po, as did disabling Ca2+ binding to EF3 and EF4 in the CaM34 mutant when compared to WT CaM. Accordingly, a previously unappreciated Ca2/CaM species promotes CaV1.2 Po and CDI, identifying Ca2/CaM as an important mediator of Ca signaling.
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Affiliation(s)
- Peter Bartels
- Department of Pharmacology, University of California, Davis, California, USA
| | - Ian Salveson
- Department of Chemistry, University of California, Davis, California, USA
| | - Andrea M Coleman
- Department of Pharmacology, University of California, Davis, California, USA; Department of Chemistry, University of California, Davis, California, USA
| | - David E Anderson
- Department of Chemistry, University of California, Davis, California, USA
| | - Grace Jeng
- Department of Pharmacology, University of California, Davis, California, USA
| | | | - Kwun Nok Mimi Man
- Department of Pharmacology, University of California, Davis, California, USA
| | - Qinhong Yu
- Department of Chemistry, University of California, Davis, California, USA
| | - Elza Kuzmenkina
- Center for Pharmacology, University of Cologne, Cologne, Germany
| | | | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, California, USA
| | - Mary C Horne
- Department of Pharmacology, University of California, Davis, California, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, California, USA.
| | - James B Ames
- Department of Chemistry, University of California, Davis, California, USA.
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Voelker TL, del Villar SG, Westhoff MF, Coleman AM, Horne MC, Hell J, Dickson EJ, Dixon RE. Acute PI(4,5)P2 regulation of Cav1.2 l-type Ca2+channels in the heart. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Turner M, Anderson DE, Bartels P, Nieves-Cintron M, Coleman AM, Henderson PB, Man KNM, Tseng PY, Yarov-Yarovoy V, Bers DM, Navedo MF, Horne MC, Ames JB, Hell JW. α-Actinin-1 promotes activity of the L-type Ca 2+ channel Ca v1.2. EMBO J 2020; 39:e106171. [PMID: 33433005 DOI: 10.15252/embj.2020106171] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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5
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Turner M, Anderson DE, Bartels P, Nieves-Cintron M, Coleman AM, Henderson PB, Man KNM, Tseng PY, Yarov-Yarovoy V, Bers DM, Navedo MF, Horne MC, Ames JB, Hell JW. α-Actinin-1 promotes activity of the L-type Ca 2+ channel Ca v 1.2. EMBO J 2020; 39:e102622. [PMID: 31985069 DOI: 10.15252/embj.2019102622] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 12/04/2019] [Accepted: 12/06/2019] [Indexed: 01/05/2023] Open
Abstract
The L-type Ca2+ channel CaV 1.2 governs gene expression, cardiac contraction, and neuronal activity. Binding of α-actinin to the IQ motif of CaV 1.2 supports its surface localization and postsynaptic targeting in neurons. We report a bi-functional mechanism that restricts CaV 1.2 activity to its target sites. We solved separate NMR structures of the IQ motif (residues 1,646-1,664) bound to α-actinin-1 and to apo-calmodulin (apoCaM). The CaV 1.2 K1647A and Y1649A mutations, which impair α-actinin-1 but not apoCaM binding, but not the F1658A and K1662E mutations, which impair apoCaM but not α-actinin-1 binding, decreased single-channel open probability, gating charge movement, and its coupling to channel opening. Thus, α-actinin recruits CaV 1.2 to defined surface regions and simultaneously boosts its open probability so that CaV 1.2 is mostly active when appropriately localized.
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Affiliation(s)
- Matthew Turner
- Department of Chemistry, University of California, Davis, CA, USA
| | - David E Anderson
- Department of Chemistry, University of California, Davis, CA, USA
| | - Peter Bartels
- Department of Pharmacology, University of California, Davis, CA, USA
| | | | - Andrea M Coleman
- Department of Chemistry, University of California, Davis, CA, USA.,Department of Pharmacology, University of California, Davis, CA, USA
| | - Peter B Henderson
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Kwun Nok Mimi Man
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Pang-Yen Tseng
- Department of Pharmacology, University of California, Davis, CA, USA
| | | | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Mary C Horne
- Department of Pharmacology, University of California, Davis, CA, USA
| | - James B Ames
- Department of Chemistry, University of California, Davis, CA, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA, USA
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Tseng PY, Henderson PB, Hergarden AC, Patriarchi T, Coleman AM, Lillya MW, Montagut-Bordas C, Lee B, Hell JW, Horne MC. α-Actinin Promotes Surface Localization and Current Density of the Ca 2+ Channel Ca V1.2 by Binding to the IQ Region of the α1 Subunit. Biochemistry 2017; 56:3669-3681. [PMID: 28613835 DOI: 10.1021/acs.biochem.7b00359] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The voltage-gated L-type Ca2+ channel CaV1.2 is crucial for initiating heartbeat and control of a number of neuronal functions such as neuronal excitability and long-term potentiation. Mutations of CaV1.2 subunits result in serious health problems, including arrhythmia, autism spectrum disorders, immunodeficiency, and hypoglycemia. Thus, precise control of CaV1.2 surface expression and localization is essential. We previously reported that α-actinin associates and colocalizes with neuronal CaV1.2 channels and that shRNA-mediated depletion of α-actinin significantly reduces localization of endogenous CaV1.2 in dendritic spines in hippocampal neurons. Here we investigated the hypothesis that direct binding of α-actinin to CaV1.2 supports its surface expression. Using two-hybrid screens and pull-down assays, we identified three point mutations (K1647A, Y1649A, and I1654A) in the central, pore-forming α11.2 subunit of CaV1.2 that individually impaired α-actinin binding. Surface biotinylation and flow cytometry assays revealed that CaV1.2 channels composed of the corresponding α-actinin-binding-deficient mutants result in a 35-40% reduction in surface expression compared to that of wild-type channels. Moreover, the mutant CaV1.2 channels expressed in HEK293 cells exhibit a 60-75% decrease in current density. The larger decrease in current density as compared to surface expression imparted by these α11.2 subunit mutations hints at the possibility that α-actinin not only stabilizes surface localization of CaV1.2 but also augments its ion conducting activity.
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Affiliation(s)
- Pang-Yen Tseng
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Peter B Henderson
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Anne C Hergarden
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Tommaso Patriarchi
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Andrea M Coleman
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Mark W Lillya
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Carlota Montagut-Bordas
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Boram Lee
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Johannes W Hell
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
| | - Mary C Horne
- Department of Pharmacology, School of Medicine, University of California , Davis, California 95615-8636, United States
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Derderian SC, Coleman AM, Jeanty C, Lim FY, Shaaban AM, Farrell JA, Hirose S, MacKenzie TC, Lee H. Favorable outcomes in high-risk congenital pulmonary airway malformations treated with multiple courses of maternal betamethasone. J Pediatr Surg 2015; 50:515-8. [PMID: 25840053 DOI: 10.1016/j.jpedsurg.2014.08.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/23/2014] [Accepted: 08/26/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND/PURPOSE Congenital pulmonary airway malformations (CPAMs) are rare congenital lung lesions often diagnosed by prenatal ultrasound. High-risk cases can result in hydrops and prenatal or postnatal demise. Antenatal betamethasone has resulted in improved survival but it is unclear how to manage patients who do not respond to a single course. METHODS We present a bi-institutional retrospective review of patients treated with multiple courses of prenatal steroids for high-risk CPAMs between 2007 and 2013. RESULTS Nine patients met inclusion criteria. All but one either had an increased CPAM volume ratio (CVR) or number of fluid-containing compartments involved after a single course of antenatal betamethasone, prompting additional courses. Four patients stabilized, three improved and two progressed after the second course. The two cases with disease progression underwent an in utero resection. There were one in utero fetal demise and two deaths within the delivery room. Both fetuses that underwent a fetal resection died. All but one mother who delivered a viable fetus had complications of pregnancy. CONCLUSIONS Multiple courses of antenatal betamethasone for high-risk fetal CPAMs often result in favorable short-term outcomes without the need for open fetal resection. Pregnancy complications are common and women within this cohort should be monitored closely.
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Affiliation(s)
- S C Derderian
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA
| | - A M Coleman
- Cincinnati Fetal Center, Division of Pediatric, General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - C Jeanty
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA
| | - F Y Lim
- Cincinnati Fetal Center, Division of Pediatric, General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - A M Shaaban
- Cincinnati Fetal Center, Division of Pediatric, General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - J A Farrell
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA
| | - S Hirose
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA
| | - T C MacKenzie
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA
| | - H Lee
- Fetal Treatment Center, Department of Surgery at The University of California, San Francisco, CA, USA.
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8
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Coleman AM. Community violence in Jamaica: A public health issue for the health profession. W INDIAN MED J 2006; 55:120-2. [PMID: 16921707 DOI: 10.1590/s0043-31442006000200011] [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: 11/22/2022]
Abstract
Societal violence is a public health concern that confronts different countries. In this paper, the author examines the situation of community violence in Jamaica and discusses steps which could be taken by the health community to curb the pervasive and growing problem of community violence.
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Affiliation(s)
- A M Coleman
- West Sussex Health and Social Services NHS Care Trust, Homefield Road, Worthing, BN 112DH, United Kingdom.
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9
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Abstract
STUDY OBJECTIVES Description of the development and results of a program in lung volume reduction surgery (LVRS) at a community hospital. DESIGN Prospective data collection. SETTING A 320-bed community hospital. PATIENTS Fifty-five patients consecutively discharged from the hospital following LVRS. The mean preoperative FEV1 averaged 28% (+/-8%) of predicted values, while the preoperative PaCO2 averaged 49 mm Hg (+/-11.5 mm Hg). Forty-eight patients completed a preoperative conditioning regimen and underwent the procedure on an elective basis. Seven patients underwent the procedure during a hospital admission for a COPD exacerbation. Eight patients required mechanical ventilation preoperatively, including three who had required long-term mechanical ventilatory support. RESULTS Three patients (5%) died in the hospital following surgery. One patient developed chronic ventilator dependence. All three of the patients who required long-term mechanical ventilation preoperatively were weaned from the ventilator and returned home. Follow-up pulmonary function testing is available for 42 patients 3 months after surgery, and for 20 patients 6 months after the operation. At 3 months, the mean FEV1 improved 0.19 L (p=0.0002), the mean improvement for FVC was 0.37 L (p=0.0001), and the mean drop in residual volume was 0.97 L (p=0.0001). Similar changes are seen at 6 months. Highly significant improvements were also seen in quality of life measurements and exercise performance. The benefits of surgical treatment of emphysema seemed similar in both elective and urgent groups. CONCLUSIONS LVRS can be done safely and effectively at a community hospital, with significant improvement in pulmonary function and quality of life.
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Affiliation(s)
- P H Bagley
- Medical Center of Central Massachusetts, Worcester, USA
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10
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Coleman AM. Cutting hospital ES (environmental services) costs with standardization. Exec Housekeep Today 1996; 17:17-8. [PMID: 10154594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- A M Coleman
- Buckeye International, Inc., Maryland Hts., MO 63043, USA
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11
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Coleman AM. Promotional strategies in occupational health. Can it be extrapolated to general preventive medicine in the Caribbean Region? W INDIAN MED J 1991; 40:155-8. [PMID: 1785193] [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: 12/28/2022]
Abstract
This article highlights promotional strategies that are currently in use in occupational health which have yielded positive results in terms of cost-effectiveness and the prevention of occupational disease. Suggestions are offered on the possible extrapolation of these strategies to disease prevention programmes in medical practice in the Caribbean Region.
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Coleman AM. Ciguatoxin-induced food poisoning in a community. Implications for disease surveillance and medical practice in Jamaica. W INDIAN MED J 1990; 39:233-8. [PMID: 2082568] [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: 12/30/2022]
Abstract
This article highlights an outbreak of food poisoning, the result of ingestion of Ciguatoxin-infected fish in a community. The case presentations of the patients involved are used to illustrate the clinical aspects of Ciguatoxin poisoning. The public health aspects of this incident and their relevance to disease surveillance are then discussed. Information of significance to general medical practice in relation to this particular type of fish poisoning, the effect of which could prove fatal in some cases, is also discussed.
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Coleman AM, Smith A, Watson L. Occupational carbamate pesticide intoxication in three farm workers. Implications and significance for occupational health in Jamaica. W INDIAN MED J 1990; 39:109-13. [PMID: 2402894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The importance of occupational health practice principles in the delivery of health care to the working population is stressed by the authors' management of an incident of occupational pesticide poisoning. The clinical management of the patients involved, as well as the occupational and environmental health management of that incident, is discussed. An illustrative case report is used to describe an occurrence of carbofuran pesticide poisoning in three female farm workers in Jamaica. This report highlights the implications and significance of this incident in terms of the sensitivity of the medical profession to similar occupational health problems.
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Affiliation(s)
- A M Coleman
- Portland Health Department, Port Antonio P.O., Jamaica
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Coleman AM. An introduction to community health. Nurs Times 1967; 63:1278-9. [PMID: 6048052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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