1
|
Qiao S, Bernasek S, Gallagher KD, O'Connell J, Yamada S, Bagheri N, Amaral LAN, Carthew RW. Energy metabolism modulates the regulatory impact of activators on gene expression. Development 2024; 151:dev201986. [PMID: 38063847 PMCID: PMC10820824 DOI: 10.1242/dev.201986] [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: 05/15/2023] [Accepted: 11/29/2023] [Indexed: 12/19/2023]
Abstract
Gene expression is a regulated process fueled by ATP consumption. Therefore, regulation must be coupled to constraints imposed by the level of energy metabolism. Here, we explore this relationship both theoretically and experimentally. A stylized mathematical model predicts that activators of gene expression have variable impact depending on metabolic rate. Activators become less essential when metabolic rate is reduced and more essential when metabolic rate is enhanced. We find that, in the Drosophila eye, expression dynamics of the yan gene are less affected by loss of EGFR-mediated activation when metabolism is reduced, and the opposite effect is seen when metabolism is enhanced. The effects are also seen at the level of pattern regularity in the adult eye, where loss of EGFR-mediated activation is mitigated by lower metabolism. We propose that gene activation is tuned by energy metabolism to allow for faithful expression dynamics in the face of variable metabolic conditions.
Collapse
Affiliation(s)
- Sha Qiao
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Sebastian Bernasek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Kevin D. Gallagher
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
| | - Jessica O'Connell
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Shigehiro Yamada
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Neda Bagheri
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL 60208, USA
| | - Luis A. N. Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL 60208, USA
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA
| | - Richard W. Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
2
|
Qiao S, Bernasek S, Gallagher KD, Yamada S, Bagheri N, Amaral LA, Carthew RW. Energy metabolism modulates the regulatory impact of activators on gene expression. bioRxiv 2023:2023.10.24.563842. [PMID: 37961620 PMCID: PMC10634812 DOI: 10.1101/2023.10.24.563842] [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] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Gene expression is a regulated process fueled by ATP consumption. Therefore, regulation must be coupled to constraints imposed by the level of energy metabolism. Here, we explore this relationship both theoretically and experimentally. A stylized mathematical model predicts that activators of gene expression have variable impact depending on metabolic rate. Activators become less essential when metabolic rate is reduced and more essential when metabolic rate is enhanced. We find that in the Drosophila eye, expression dynamics of the yan gene are less affected by loss of EGFR-mediated activation when metabolism is reduced, and the opposite effect is seen when metabolism is enhanced. The effects are also seen at the level of pattern regularity in the adult eye, where loss of EGFR-mediated activation is mitigated by lower metabolism. We propose that gene activation is tuned by energy metabolism to allow for faithful expression dynamics in the face of variable metabolic conditions.
Collapse
Affiliation(s)
- Sha Qiao
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
| | - Sebastian Bernasek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL
| | - Kevin D. Gallagher
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL
| | - Shigehiro Yamada
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
| | - Neda Bagheri
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL
| | - Luis A.N. Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL
- Department of Physics and Astronomy, Northwestern University, Evanston, IL
| | - Richard W. Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL
- Lead Contact
| |
Collapse
|
3
|
Gallagher KD, Mani M, Carthew RW. Emergence of a geometric pattern of cell fates from tissue-scale mechanics in the Drosophila eye. eLife 2022; 11:72806. [PMID: 35037852 PMCID: PMC8863370 DOI: 10.7554/elife.72806] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 01/15/2022] [Indexed: 12/02/2022] Open
Abstract
Pattern formation of biological structures involves the arrangement of different types of cells in an ordered spatial configuration. In this study, we investigate the mechanism of patterning the Drosophila eye epithelium into a precise triangular grid of photoreceptor clusters called ommatidia. Previous studies had led to a long-standing biochemical model whereby a reaction-diffusion process is templated by recently formed ommatidia to propagate a molecular prepattern across the eye. Here, we find that the templating mechanism is instead, mechanochemical in origin; newly born columns of differentiating ommatidia serve as a template to spatially pattern flows that move epithelial cells into position to form each new column of ommatidia. Cell flow is generated by a source and sink, corresponding to narrow zones of cell dilation and contraction respectively, that straddle the growing wavefront of ommatidia. The newly formed lattice grid of ommatidia cells are immobile, deflecting, and focusing the flow of other cells. Thus, the self-organization of a regular pattern of cell fates in an epithelium is mechanically driven.
Collapse
Affiliation(s)
- Kevin D Gallagher
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States
| | - Madhav Mani
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States,Department of Engineering Sciences and Applied Mathematics, Northwestern UniversityEvanstonUnited States
| | - Richard W Carthew
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States
| |
Collapse
|
4
|
Woitowich NC, Halavaty AS, Waltz P, Kupitz C, Valera J, Tracy G, Gallagher KD, Claesson E, Nakane T, Pandey S, Nelson G, Tanaka R, Nango E, Mizohata E, Owada S, Tono K, Joti Y, Nugent AC, Patel H, Mapara A, Hopkins J, Duong P, Bizhga D, Kovaleva SE, St. Peter R, Hernandez CN, Ozarowski WB, Roy-Chowdhuri S, Yang JH, Edlund P, Takala H, Ihalainen J, Brayshaw J, Norwood T, Poudyal I, Fromme P, Spence JCH, Moffat K, Westenhoff S, Schmidt M, Stojković EA. Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome. IUCrJ 2018; 5:619-634. [PMID: 30224965 PMCID: PMC6126659 DOI: 10.1107/s2052252518010631] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 07/23/2018] [Indexed: 05/11/2023]
Abstract
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxo-bacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruiting-body formation of this photomorphogenic bacterium. SaBphP1 lacks a conserved histidine (His) in the chromophore-binding domain that stabilizes the Pr state in the classical BphPs. Instead it contains a threonine (Thr), a feature that is restricted to several myxobacterial phytochromes and is not evolutionarily understood. SaBphP1 structures of the chromophore binding domain (CBD) and the complete photosensory core module (PCM) in wild-type and Thr-to-His mutant forms reveal details of the molecular mechanism of the Pr/Pfr transition associated with the physiological response of this myxobacterium to red light. Specifically, key structural differences in the CBD and PCM between the wild-type and the Thr-to-His mutant involve essential chromophore contacts with proximal amino acids, and point to how the photosignal is transduced through the rest of the protein, impacting the essential enzymatic activity in the photomorphogenic response of this myxobacterium.
Collapse
Affiliation(s)
| | - Andrei S. Halavaty
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Patricia Waltz
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | | | - Joseph Valera
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Gregory Tracy
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Kevin D. Gallagher
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Elin Claesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Takanori Nakane
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Suraj Pandey
- Department of Physics, University of Wisconsin, Milwaukee, WI, USA
| | - Garrett Nelson
- Center for Applied Structural Discovery, Arizona State University, 85287 Tempe, AZ, USA
| | - Rie Tanaka
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Eriko Nango
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
| | - Eiichi Mizohata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
| | - Kensure Tono
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Yasumasa Joti
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Angela C. Nugent
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Hardik Patel
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Ayesha Mapara
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - James Hopkins
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Phu Duong
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | - Dorina Bizhga
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | | | - Rachael St. Peter
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| | | | | | | | - Jay-How Yang
- Center for Applied Structural Discovery, Arizona State University, 85287 Tempe, AZ, USA
| | - Petra Edlund
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Heikki Takala
- Faculty of Medicine, Anatomy, University of Helsinki, 00014 Helsinki, Finland
- Nanoscience Center, Department of Biological and Environmental Sciences, University of Jyvaskyla, 40014 Jyvaskyla, Finland
| | - Janne Ihalainen
- Nanoscience Center, Department of Biological and Environmental Sciences, University of Jyvaskyla, 40014 Jyvaskyla, Finland
| | | | - Tyler Norwood
- Department of Physics, University of Wisconsin, Milwaukee, WI, USA
| | - Ishwor Poudyal
- Department of Physics, University of Wisconsin, Milwaukee, WI, USA
| | - Petra Fromme
- Center for Applied Structural Discovery, Arizona State University, 85287 Tempe, AZ, USA
| | - John C. H. Spence
- Center for Applied Structural Discovery, Arizona State University, 85287 Tempe, AZ, USA
| | - Keith Moffat
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Marius Schmidt
- Department of Physics, University of Wisconsin, Milwaukee, WI, USA
| | - Emina A. Stojković
- Department of Biology, Northeastern Illinois University, Chicago, IL, USA
| |
Collapse
|
5
|
Björling A, Berntsson O, Takala H, Gallagher KD, Patel H, Gustavsson E, St Peter R, Duong P, Nugent A, Zhang F, Berntsen P, Appio R, Rajkovic I, Lehtivuori H, Panman MR, Hoernke M, Niebling S, Harimoorthy R, Lamparter T, Stojković EA, Ihalainen JA, Westenhoff S. Ubiquitous Structural Signaling in Bacterial Phytochromes. J Phys Chem Lett 2015; 6:3379-83. [PMID: 26275765 DOI: 10.1021/acs.jpclett.5b01629] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The phytochrome family of light-switchable proteins has long been studied by biochemical, spectroscopic and crystallographic means, while a direct probe for global conformational signal propagation has been lacking. Using solution X-ray scattering, we find that the photosensory cores of several bacterial phytochromes undergo similar large-scale structural changes upon red-light excitation. The data establish that phytochromes with ordinary and inverted photocycles share a structural signaling mechanism and that a particular conserved histidine, previously proposed to be involved in signal propagation, in fact tunes photoresponse.
Collapse
Affiliation(s)
- Alexander Björling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Heikki Takala
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Kevin D Gallagher
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Hardik Patel
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Rachael St Peter
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Phu Duong
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Angela Nugent
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Fan Zhang
- Botanical Institute, Karlsruhe Institute of Technology KIT , Kaiserstr. 2, 76131 Karlsruhe, Germany
| | - Peter Berntsen
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
- Centre for Advanced Molecular Imaging, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
| | - Roberto Appio
- MAX IV Laboratory, Lund University , P.O. Box 118, Lund SE-221 00, Sweden
| | - Ivan Rajkovic
- Paul Scherrer Institut , 5232 Villigen PSI, Switzerland
| | - Heli Lehtivuori
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Matthijs R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Maria Hoernke
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Rajiv Harimoorthy
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Tilman Lamparter
- Botanical Institute, Karlsruhe Institute of Technology KIT , Kaiserstr. 2, 76131 Karlsruhe, Germany
| | - Emina A Stojković
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Janne A Ihalainen
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| |
Collapse
|
6
|
Mathes T, Ravensbergen J, Kloz M, Gleichmann T, Gallagher KD, Woitowich NC, St Peter R, Kovaleva SE, Stojković EA, Kennis JTM. Femto- to Microsecond Photodynamics of an Unusual Bacteriophytochrome. J Phys Chem Lett 2015; 6:239-43. [PMID: 26263456 DOI: 10.1021/jz502408n] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A bacteriophytochrome from Stigmatella aurantiaca is an unusual member of the bacteriophytochrome family that is devoid of hydrogen bonding to the carbonyl group of ring D of the biliverdin (BV) chromophore. The photodynamics of BV in SaBphP1 wild type and the single mutant T289H reintroducing hydrogen bonding to ring D show that the strength of this particular weak interaction determines excited-state lifetime, Lumi-R quantum yield, and spectral heterogeneity. In particular, excited-state decay is faster in the absence of hydrogen-bonding to ring D, with excited-state half-lives of 30 and 80 ps for wild type and the T289H mutant, respectively. Concomitantly, the Lumi-R quantum yield is two times higher in wild type as compared with the T289H mutant. Furthermore, the spectral heterogeneity in the wild type is significantly higher than that in the T289H mutant. By extending the observable time domain to 25 μs, we observe a new deactivation pathway from the Lumi-R intermediate in the 100 ns time domain that corresponds to a backflip of ring D to the original Pr 15Za isomeric state.
Collapse
Affiliation(s)
- Tilo Mathes
- †Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Janneke Ravensbergen
- †Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Miroslav Kloz
- †Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Tobias Gleichmann
- †Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Kevin D Gallagher
- ‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Nicole C Woitowich
- ‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Rachael St Peter
- ‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Svetlana E Kovaleva
- ‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Emina A Stojković
- ‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - John T M Kennis
- †Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| |
Collapse
|
7
|
Syed JH, Alamdar A, Mohammad A, Ahad K, Shabir Z, Ahmed H, Ali SM, Sani SGAS, Bokhari H, Gallagher KD, Ahmad I, Eqani SAMAS. Pesticide residues in fruits and vegetables from Pakistan: a review of the occurrence and associated human health risks. Environ Sci Pollut Res Int 2014; 21:13367-13393. [PMID: 24958529 DOI: 10.1007/s11356-014-3117-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
The main objective of the review is to document, assess and analyze the results of the previously reported data on levels of different pesticides in selected fruits and vegetables from Pakistan. The findings of the previous studies clearly indicated that more than 50 % of the samples were contaminated with organophosphate, pyrethroids and organochlorine pesticides. Many studies reported that among fresh fruits and vegetables tomato, apple, melon, mango, grapes, and plum crossed the FAO/WHO permissible limits for these contaminants residual levels. The comparison of other regions showed that observed levels were found above maximum residue limits (MRLs) in 50 % of the samples but were in agreement with the studies from neighboring countries like China and Bangladesh. Higher hazard risk index (HRI) values were calculated for dieldrin, methamidophos, o,p'-DDT, diazinon and p,p'-DDT in apple, mango, banana, melon, potato and onion. The review also highlights that data on pesticide residues in foodstuff is scarce which should be overcome by further extending studies from different areas of Pakistan. In order to ascertain the provision of food suitable for human consumption, it is imperative to monitor pesticides in food commodities by the country's authorities and enforce guidelines based on permissible limits.
Collapse
Affiliation(s)
- Jabir Hussain Syed
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Chang A, Hearey CD, Gallagher KD, English P, Chang PC. Promoting child passenger safety in children served by a health maintenance organization. Patient Educ Couns 1989; 13:297-307. [PMID: 10293483 DOI: 10.1016/0738-3991(89)90023-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A patient education program, based on the health belief model, promoting child passenger safety was developed and implemented at a health maintenance organization. The program included individual counseling by pediatricians, use of audiovisual materials and pamphlets, and (for newborn infants) a home visit by a child safety specialist. Based on parking lot observations, child safety device use increased to greater than 60% in both intervention and comparison-group children 1-4 years of age. During the child health supervision visit, pediatricians can play a leadership role in promoting child passenger safety.
Collapse
|