Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption
Genital tract bacterial infections could induce abortion and are some of the most common complications of pregnancy; however, the mechanisms remain unclear. We investigated the role of prostaglandins (PGs) in the mechanism of bacterial lipopolysaccharide (LPS)-induced pregnancy loss in a mouse model...
Gespeichert in:
| Veröffentlicht in: | Proceedings of the National Academy of Sciences - PNAS 2007-05, Vol.104 (18), p.7534-7539 |
|---|---|
| Hauptverfasser: | , , , , , , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | 7539 |
|---|---|
| container_issue | 18 |
| container_start_page | 7534 |
| container_title | Proceedings of the National Academy of Sciences - PNAS |
| container_volume | 104 |
| creator | Aisemberg, J Vercelli, C Billi, S Ribeiro, M.L Ogando, D Meiss, R McCann, S.M Rettori, V Franchi, A.M |
| description | Genital tract bacterial infections could induce abortion and are some of the most common complications of pregnancy; however, the mechanisms remain unclear. We investigated the role of prostaglandins (PGs) in the mechanism of bacterial lipopolysaccharide (LPS)-induced pregnancy loss in a mouse model, and we hypothesized that PGs might play a central role in this action. LPS increased PG production in the uterus and decidua from early pregnant mice and stimulated cyclooxygenase (COX)-II mRNA and protein expression in the decidua but not in the uterus. We also observed that COX inhibitors prevented embryonic resorption (ER). To study the possible interaction between nitric oxide (NO) and PGs, we administered aminoguanidine, an inducible NO synthase inhibitor. NO inhibited basal PGE and PGF₂α production in the decidua but activated their uterine synthesis and COX-II mRNA expression under septic conditions. A NO donor (S-nitroso-N-acetylpenicillamine) produced 100% ER and increased PG levels in the uterus and decidua. LPS-stimulated protein nitration was higher in the uterus than in the decidua. Quercetin, a peroxynitrite scavenger, did not reverse LPS-induced ER. Our results suggest that in a model of septic abortion characterized by increased PG levels, NO might nitrate and thus inhibit COX catalytic activity. ER prevention by COX inhibitors adds a possible clinical application to early pregnancy complications due to infections. |
| doi_str_mv | 10.1073/pnas.0702279104 |
| format | Article |
| fullrecord | <record><control><sourceid>jstor_pnas_</sourceid><recordid>TN_cdi_pnas_primary_104_18_7534</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><jstor_id>25427522</jstor_id><sourcerecordid>25427522</sourcerecordid><originalsourceid>FETCH-LOGICAL-c552t-2c1a7daf665907c2eb5ff6afffcc079f3aab40927e4edf28de267127c572ee273</originalsourceid><addsrcrecordid>eNp9kU1v1DAURS0EokNhzQqwWACbtM-OHScbJFTxJVWwgK4tj_OcepSJU9tB7b_Hoxl1gAUrL3zese-7hDxncMZA1efzZNIZKOBcdQzEA7Ji0LGqER08JCsArqpWcHFCnqS0AYBOtvCYnDAlGoBarsj8zefoLQ23vke6xd6bjInOMaRshtFMvZ_SW9rjiBmjD0ui6BzaTMNERz-HOYx3yVh7bWIxVEU2DBixp9sl-gmpw2xGGjGFOGcfpqfkkTNjwmeH85Rcffr48-JLdfn989eLD5eVlZLniltmVG9c08gOlOW4ls41xjlnLajO1casBXRcocDe8bZH3ijGlZWKI3JVn5L3e--8rEssi1OOZtRz9FsT73QwXv99M_lrPYRfmrVNLYQogjcHQQw3C6astz5ZHMtOsKxBs65pea14AV__A27CEqcSTnNggkkl6wKd7yFbNpsiuvufMNC7KvWuSn2ssky8_DPAkT90V4BXB2A3edSJEkGXN3eKd_8ntFvGMeNtLuiLPbpJOcR7lkvBleT8-JgzQZsh-qSvfpR4NYBSTLWy_g3Qz8mU</addsrcrecordid><sourcetype>Open Access Repository</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>201415753</pqid></control><display><type>article</type><title>Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption</title><source>MEDLINE</source><source>JSTOR Archive Collection A-Z Listing</source><source>PubMed Central</source><source>Alma/SFX Local Collection</source><source>Free Full-Text Journals in Chemistry</source><creator>Aisemberg, J ; Vercelli, C ; Billi, S ; Ribeiro, M.L ; Ogando, D ; Meiss, R ; McCann, S.M ; Rettori, V ; Franchi, A.M</creator><creatorcontrib>Aisemberg, J ; Vercelli, C ; Billi, S ; Ribeiro, M.L ; Ogando, D ; Meiss, R ; McCann, S.M ; Rettori, V ; Franchi, A.M</creatorcontrib><description>Genital tract bacterial infections could induce abortion and are some of the most common complications of pregnancy; however, the mechanisms remain unclear. We investigated the role of prostaglandins (PGs) in the mechanism of bacterial lipopolysaccharide (LPS)-induced pregnancy loss in a mouse model, and we hypothesized that PGs might play a central role in this action. LPS increased PG production in the uterus and decidua from early pregnant mice and stimulated cyclooxygenase (COX)-II mRNA and protein expression in the decidua but not in the uterus. We also observed that COX inhibitors prevented embryonic resorption (ER). To study the possible interaction between nitric oxide (NO) and PGs, we administered aminoguanidine, an inducible NO synthase inhibitor. NO inhibited basal PGE and PGF₂α production in the decidua but activated their uterine synthesis and COX-II mRNA expression under septic conditions. A NO donor (S-nitroso-N-acetylpenicillamine) produced 100% ER and increased PG levels in the uterus and decidua. LPS-stimulated protein nitration was higher in the uterus than in the decidua. Quercetin, a peroxynitrite scavenger, did not reverse LPS-induced ER. Our results suggest that in a model of septic abortion characterized by increased PG levels, NO might nitrate and thus inhibit COX catalytic activity. ER prevention by COX inhibitors adds a possible clinical application to early pregnancy complications due to infections.</description><identifier>ISSN: 0027-8424</identifier><identifier>EISSN: 1091-6490</identifier><identifier>DOI: 10.1073/pnas.0702279104</identifier><identifier>PMID: 17460035</identifier><language>eng</language><publisher>United States: National Academy of Sciences</publisher><subject>Animal reproduction ; Animals ; Antibodies ; Bacteria ; Biological Sciences ; Control groups ; Cyclooxygenase Inhibitors - pharmacology ; Dosage ; Endometrium ; Female ; Fetal Resorption - chemically induced ; Fetal Resorption - metabolism ; Hormones ; Infections ; Isoenzymes - genetics ; Isoenzymes - metabolism ; Lipopolysaccharides - pharmacology ; Male ; Messenger RNA ; Mice ; Mice, Inbred BALB C ; Nitration ; Nitric oxide ; Nitric Oxide - metabolism ; Nitric Oxide Synthase - metabolism ; Oxides ; Pregnancy ; Prostaglandin-Endoperoxide Synthases - genetics ; Prostaglandin-Endoperoxide Synthases - metabolism ; Prostaglandins ; Prostaglandins - metabolism ; Reactive Oxygen Species - metabolism ; RNA, Messenger - genetics ; Rodents ; Signal Transduction ; Tyrosine - metabolism ; Uterus</subject><ispartof>Proceedings of the National Academy of Sciences - PNAS, 2007-05, Vol.104 (18), p.7534-7539</ispartof><rights>Copyright 2007 The National Academy of Sciences of the United States of America</rights><rights>Copyright National Academy of Sciences May 1, 2007</rights><rights>2007 by The National Academy of Sciences of the USA 2007</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c552t-2c1a7daf665907c2eb5ff6afffcc079f3aab40927e4edf28de267127c572ee273</citedby><cites>FETCH-LOGICAL-c552t-2c1a7daf665907c2eb5ff6afffcc079f3aab40927e4edf28de267127c572ee273</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Uhttp://www.pnas.org/content/104/18.cover.gif</thumbnail><linktopdf>$$Uhttps://www.jstor.org/stable/pdf/25427522$$EPDF$$P50$$Gjstor$$H</linktopdf><linktohtml>$$Uhttps://www.jstor.org/stable/25427522$$EHTML$$P50$$Gjstor$$H</linktohtml><link.rule.ids>230,314,727,780,784,803,885,27924,27925,53791,53793,58017,58250</link.rule.ids><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/17460035$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Aisemberg, J</creatorcontrib><creatorcontrib>Vercelli, C</creatorcontrib><creatorcontrib>Billi, S</creatorcontrib><creatorcontrib>Ribeiro, M.L</creatorcontrib><creatorcontrib>Ogando, D</creatorcontrib><creatorcontrib>Meiss, R</creatorcontrib><creatorcontrib>McCann, S.M</creatorcontrib><creatorcontrib>Rettori, V</creatorcontrib><creatorcontrib>Franchi, A.M</creatorcontrib><title>Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption</title><title>Proceedings of the National Academy of Sciences - PNAS</title><addtitle>Proc Natl Acad Sci U S A</addtitle><description>Genital tract bacterial infections could induce abortion and are some of the most common complications of pregnancy; however, the mechanisms remain unclear. We investigated the role of prostaglandins (PGs) in the mechanism of bacterial lipopolysaccharide (LPS)-induced pregnancy loss in a mouse model, and we hypothesized that PGs might play a central role in this action. LPS increased PG production in the uterus and decidua from early pregnant mice and stimulated cyclooxygenase (COX)-II mRNA and protein expression in the decidua but not in the uterus. We also observed that COX inhibitors prevented embryonic resorption (ER). To study the possible interaction between nitric oxide (NO) and PGs, we administered aminoguanidine, an inducible NO synthase inhibitor. NO inhibited basal PGE and PGF₂α production in the decidua but activated their uterine synthesis and COX-II mRNA expression under septic conditions. A NO donor (S-nitroso-N-acetylpenicillamine) produced 100% ER and increased PG levels in the uterus and decidua. LPS-stimulated protein nitration was higher in the uterus than in the decidua. Quercetin, a peroxynitrite scavenger, did not reverse LPS-induced ER. Our results suggest that in a model of septic abortion characterized by increased PG levels, NO might nitrate and thus inhibit COX catalytic activity. ER prevention by COX inhibitors adds a possible clinical application to early pregnancy complications due to infections.</description><subject>Animal reproduction</subject><subject>Animals</subject><subject>Antibodies</subject><subject>Bacteria</subject><subject>Biological Sciences</subject><subject>Control groups</subject><subject>Cyclooxygenase Inhibitors - pharmacology</subject><subject>Dosage</subject><subject>Endometrium</subject><subject>Female</subject><subject>Fetal Resorption - chemically induced</subject><subject>Fetal Resorption - metabolism</subject><subject>Hormones</subject><subject>Infections</subject><subject>Isoenzymes - genetics</subject><subject>Isoenzymes - metabolism</subject><subject>Lipopolysaccharides - pharmacology</subject><subject>Male</subject><subject>Messenger RNA</subject><subject>Mice</subject><subject>Mice, Inbred BALB C</subject><subject>Nitration</subject><subject>Nitric oxide</subject><subject>Nitric Oxide - metabolism</subject><subject>Nitric Oxide Synthase - metabolism</subject><subject>Oxides</subject><subject>Pregnancy</subject><subject>Prostaglandin-Endoperoxide Synthases - genetics</subject><subject>Prostaglandin-Endoperoxide Synthases - metabolism</subject><subject>Prostaglandins</subject><subject>Prostaglandins - metabolism</subject><subject>Reactive Oxygen Species - metabolism</subject><subject>RNA, Messenger - genetics</subject><subject>Rodents</subject><subject>Signal Transduction</subject><subject>Tyrosine - metabolism</subject><subject>Uterus</subject><issn>0027-8424</issn><issn>1091-6490</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2007</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><recordid>eNp9kU1v1DAURS0EokNhzQqwWACbtM-OHScbJFTxJVWwgK4tj_OcepSJU9tB7b_Hoxl1gAUrL3zese-7hDxncMZA1efzZNIZKOBcdQzEA7Ji0LGqER08JCsArqpWcHFCnqS0AYBOtvCYnDAlGoBarsj8zefoLQ23vke6xd6bjInOMaRshtFMvZ_SW9rjiBmjD0ui6BzaTMNERz-HOYx3yVh7bWIxVEU2DBixp9sl-gmpw2xGGjGFOGcfpqfkkTNjwmeH85Rcffr48-JLdfn989eLD5eVlZLniltmVG9c08gOlOW4ls41xjlnLajO1casBXRcocDe8bZH3ijGlZWKI3JVn5L3e--8rEssi1OOZtRz9FsT73QwXv99M_lrPYRfmrVNLYQogjcHQQw3C6astz5ZHMtOsKxBs65pea14AV__A27CEqcSTnNggkkl6wKd7yFbNpsiuvufMNC7KvWuSn2ssky8_DPAkT90V4BXB2A3edSJEkGXN3eKd_8ntFvGMeNtLuiLPbpJOcR7lkvBleT8-JgzQZsh-qSvfpR4NYBSTLWy_g3Qz8mU</recordid><startdate>20070501</startdate><enddate>20070501</enddate><creator>Aisemberg, J</creator><creator>Vercelli, C</creator><creator>Billi, S</creator><creator>Ribeiro, M.L</creator><creator>Ogando, D</creator><creator>Meiss, R</creator><creator>McCann, S.M</creator><creator>Rettori, V</creator><creator>Franchi, A.M</creator><general>National Academy of Sciences</general><general>National Acad Sciences</general><scope>FBQ</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7QG</scope><scope>7QL</scope><scope>7QP</scope><scope>7QR</scope><scope>7SN</scope><scope>7SS</scope><scope>7T5</scope><scope>7TK</scope><scope>7TM</scope><scope>7TO</scope><scope>7U9</scope><scope>8FD</scope><scope>C1K</scope><scope>FR3</scope><scope>H94</scope><scope>M7N</scope><scope>P64</scope><scope>RC3</scope><scope>5PM</scope></search><sort><creationdate>20070501</creationdate><title>Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption</title><author>Aisemberg, J ; Vercelli, C ; Billi, S ; Ribeiro, M.L ; Ogando, D ; Meiss, R ; McCann, S.M ; Rettori, V ; Franchi, A.M</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c552t-2c1a7daf665907c2eb5ff6afffcc079f3aab40927e4edf28de267127c572ee273</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2007</creationdate><topic>Animal reproduction</topic><topic>Animals</topic><topic>Antibodies</topic><topic>Bacteria</topic><topic>Biological Sciences</topic><topic>Control groups</topic><topic>Cyclooxygenase Inhibitors - pharmacology</topic><topic>Dosage</topic><topic>Endometrium</topic><topic>Female</topic><topic>Fetal Resorption - chemically induced</topic><topic>Fetal Resorption - metabolism</topic><topic>Hormones</topic><topic>Infections</topic><topic>Isoenzymes - genetics</topic><topic>Isoenzymes - metabolism</topic><topic>Lipopolysaccharides - pharmacology</topic><topic>Male</topic><topic>Messenger RNA</topic><topic>Mice</topic><topic>Mice, Inbred BALB C</topic><topic>Nitration</topic><topic>Nitric oxide</topic><topic>Nitric Oxide - metabolism</topic><topic>Nitric Oxide Synthase - metabolism</topic><topic>Oxides</topic><topic>Pregnancy</topic><topic>Prostaglandin-Endoperoxide Synthases - genetics</topic><topic>Prostaglandin-Endoperoxide Synthases - metabolism</topic><topic>Prostaglandins</topic><topic>Prostaglandins - metabolism</topic><topic>Reactive Oxygen Species - metabolism</topic><topic>RNA, Messenger - genetics</topic><topic>Rodents</topic><topic>Signal Transduction</topic><topic>Tyrosine - metabolism</topic><topic>Uterus</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Aisemberg, J</creatorcontrib><creatorcontrib>Vercelli, C</creatorcontrib><creatorcontrib>Billi, S</creatorcontrib><creatorcontrib>Ribeiro, M.L</creatorcontrib><creatorcontrib>Ogando, D</creatorcontrib><creatorcontrib>Meiss, R</creatorcontrib><creatorcontrib>McCann, S.M</creatorcontrib><creatorcontrib>Rettori, V</creatorcontrib><creatorcontrib>Franchi, A.M</creatorcontrib><collection>AGRIS</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>Animal Behavior Abstracts</collection><collection>Bacteriology Abstracts (Microbiology B)</collection><collection>Calcium & Calcified Tissue Abstracts</collection><collection>Chemoreception Abstracts</collection><collection>Ecology Abstracts</collection><collection>Entomology Abstracts (Full archive)</collection><collection>Immunology Abstracts</collection><collection>Neurosciences Abstracts</collection><collection>Nucleic Acids Abstracts</collection><collection>Oncogenes and Growth Factors Abstracts</collection><collection>Virology and AIDS Abstracts</collection><collection>Technology Research Database</collection><collection>Environmental Sciences and Pollution Management</collection><collection>Engineering Research Database</collection><collection>AIDS and Cancer Research Abstracts</collection><collection>Algology Mycology and Protozoology Abstracts (Microbiology C)</collection><collection>Biotechnology and BioEngineering Abstracts</collection><collection>Genetics Abstracts</collection><collection>PubMed Central (Full Participant titles)</collection><jtitle>Proceedings of the National Academy of Sciences - PNAS</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Aisemberg, J</au><au>Vercelli, C</au><au>Billi, S</au><au>Ribeiro, M.L</au><au>Ogando, D</au><au>Meiss, R</au><au>McCann, S.M</au><au>Rettori, V</au><au>Franchi, A.M</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption</atitle><jtitle>Proceedings of the National Academy of Sciences - PNAS</jtitle><addtitle>Proc Natl Acad Sci U S A</addtitle><date>2007-05-01</date><risdate>2007</risdate><volume>104</volume><issue>18</issue><spage>7534</spage><epage>7539</epage><pages>7534-7539</pages><issn>0027-8424</issn><eissn>1091-6490</eissn><abstract>Genital tract bacterial infections could induce abortion and are some of the most common complications of pregnancy; however, the mechanisms remain unclear. We investigated the role of prostaglandins (PGs) in the mechanism of bacterial lipopolysaccharide (LPS)-induced pregnancy loss in a mouse model, and we hypothesized that PGs might play a central role in this action. LPS increased PG production in the uterus and decidua from early pregnant mice and stimulated cyclooxygenase (COX)-II mRNA and protein expression in the decidua but not in the uterus. We also observed that COX inhibitors prevented embryonic resorption (ER). To study the possible interaction between nitric oxide (NO) and PGs, we administered aminoguanidine, an inducible NO synthase inhibitor. NO inhibited basal PGE and PGF₂α production in the decidua but activated their uterine synthesis and COX-II mRNA expression under septic conditions. A NO donor (S-nitroso-N-acetylpenicillamine) produced 100% ER and increased PG levels in the uterus and decidua. LPS-stimulated protein nitration was higher in the uterus than in the decidua. Quercetin, a peroxynitrite scavenger, did not reverse LPS-induced ER. Our results suggest that in a model of septic abortion characterized by increased PG levels, NO might nitrate and thus inhibit COX catalytic activity. ER prevention by COX inhibitors adds a possible clinical application to early pregnancy complications due to infections.</abstract><cop>United States</cop><pub>National Academy of Sciences</pub><pmid>17460035</pmid><doi>10.1073/pnas.0702279104</doi><tpages>6</tpages><oa>free_for_read</oa></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0027-8424 |
| ispartof | Proceedings of the National Academy of Sciences - PNAS, 2007-05, Vol.104 (18), p.7534-7539 |
| issn | 0027-8424 1091-6490 |
| language | eng |
| recordid | cdi_pnas_primary_104_18_7534 |
| source | MEDLINE; JSTOR Archive Collection A-Z Listing; PubMed Central; Alma/SFX Local Collection; Free Full-Text Journals in Chemistry |
| subjects | Animal reproduction Animals Antibodies Bacteria Biological Sciences Control groups Cyclooxygenase Inhibitors - pharmacology Dosage Endometrium Female Fetal Resorption - chemically induced Fetal Resorption - metabolism Hormones Infections Isoenzymes - genetics Isoenzymes - metabolism Lipopolysaccharides - pharmacology Male Messenger RNA Mice Mice, Inbred BALB C Nitration Nitric oxide Nitric Oxide - metabolism Nitric Oxide Synthase - metabolism Oxides Pregnancy Prostaglandin-Endoperoxide Synthases - genetics Prostaglandin-Endoperoxide Synthases - metabolism Prostaglandins Prostaglandins - metabolism Reactive Oxygen Species - metabolism RNA, Messenger - genetics Rodents Signal Transduction Tyrosine - metabolism Uterus |
| title | Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-21T18%3A12%3A00IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-jstor_pnas_&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Nitric%20oxide%20mediates%20prostaglandins'%20deleterious%20effect%20on%20lipopolysaccharide-triggered%20murine%20fetal%20resorption&rft.jtitle=Proceedings%20of%20the%20National%20Academy%20of%20Sciences%20-%20PNAS&rft.au=Aisemberg,%20J&rft.date=2007-05-01&rft.volume=104&rft.issue=18&rft.spage=7534&rft.epage=7539&rft.pages=7534-7539&rft.issn=0027-8424&rft.eissn=1091-6490&rft_id=info:doi/10.1073/pnas.0702279104&rft_dat=%3Cjstor_pnas_%3E25427522%3C/jstor_pnas_%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=201415753&rft_id=info:pmid/17460035&rft_jstor_id=25427522&rfr_iscdi=true |