المؤلفون: Discigil, Berent, King, R. Michael, Pearson, Paul J., Capellini, Verena K., Rodrigues, Alfredo José, Schaff, Hartzell V., Evora, Paulo Roberto Barbosa

المصدر: Brazilian Journal of Cardiovascular Surgery. June 2008 23(2)

مصطلحات موضوعية: Ultra-som, Óxido nítrico, Endarterectomia, Doença das coronárias

الوصف: OBJETIVO: Aplicação de energia por ultra-som pode facilitar a remoção da placa ateromatosa, mas o efeito desse procedimento em vasos próximos ainda é matéria de estudos experimentais. MÉTODOS: Para determinar se a energia ultra-sônica compromete a produção de óxido nítrico, segmentos de artérias coronárias caninas foram expostos a baixos (0-10 W) e altos (25 W) níveis de energia por 15 segundos, utilizando-se protótipo de aparelho para a realização de endarterectomia. Após exposição, segmentos das artérias coronarianas foram estudados em organ chambers. Para os ensaios farmacológicos foram utilizadas as seguintes drogas:difosfato de adenosina (ADP), acetilcolina (Ach) e fluoreto de sódio (NaF) para a avaliação do relaxamento dependente do endotélio. O nitroprussiato de sódio (NPS) e o isoproterenol foram utilizados para a avaliação do relaxamento independente do endotélio. RESULTADOS: A aplicação de alta energia ultra-sônica comprometeu o relaxamento dependente do endotélio induzido por ADP (10-9 - 10-4 M), Ach (10-9 - 10-4 M) e NaF (0,5 -9,5 mM) em artérias coronarianas epicárdicas. Entretanto, baixos valores de energia ultra-sônica não alteraram o relaxamento dependente do endotélio (nem o relaxamento máximo e nem a EC50) induzido pelos mesmos agonistas. O relaxamento da musculatura lisa vascular induzido por isoproterenol (10-9 - 10-5 M) ou NPS (10-9 - 10-6 M) não foi comprometido, tanto por baixos, quanto por altos níveis de energia ultra-sônica. CONCLUSÃO: Os experimentos demonstram que altas energias ultra-sônicas alteram a função endotelial. Entretanto, o ultra-som não altera a habilidade de relaxamento da musculatura lisa vascular de artérias caninas epicárdicas.

وصف الملف: text/html

الوصول الحر: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-76382008000200007Test

المؤلفون: Evora, Paulo R. B., Pearson, Paul J., Rodrigues, Alfredo José, Viaro, Fernanda, Schaff, Hartzell V.

المصدر: Arquivos Brasileiros de Cardiologia. June 2003 80(6)

مصطلحات موضوعية: poly-L-arginine, polycations, nitric oxide, EDHF, endothelium

الوصف: OBJECTIVE: To study the mechanism by which poly-L-arginine mediates endothelium-dependent relaxation. METHODS: Vascular segments with and without endothelium were suspended in organ chambers filled with control solution maintained at 37ºC and bubbled with 95% O2 / 5% CO2. Used drugs: indomethacin, acetycholine, EGTA, glybenclamide, ouabain, poly-L-arginine, methylene blue, N G-nitro-L-arginine, and verapamil and N G-monomethyl-L-arginine. Prostaglandin F2á and potassium chloride were used to contract the vascular rings. RESULTS: Poly-L-arginine (10-11 to 10-7 M) induced concentration-dependent relaxation in coronary artery segments with endothelium. The relaxation to poly-L-arginine was attenuated by ouabain, but was unaffected by glybenclamide. L-NOARG and oxyhemoglobin caused attenuation, but did not abolish this relaxation. Also, the relaxations was unaffected by methylene blue, verapamil, or the presence of a calcium-free bathing medium. The endothelium-dependent to poly-L-arginine relaxation was abolished only in vessels contracted with potassium chloride (40 mM) in the presence of L-NOARG and indomethacin. CONCLUSION: These experiments indicate that poly-L-arginine induces relaxation independent of nitric oxide.

وصف الملف: text/html

الوصول الحر: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2003000600005Test

المؤلفون: Evora, Paulo Roberto B., Pearson, Paul J., Rodrigues, Alfredo J., Viaro, Fernanda, Schaff, Hartzell V.

المصدر: Arquivos Brasileiros de Cardiologia. May 2003 80(5)

مصطلحات موضوعية: coronary artery, vasopressin, endothelium, nitric oxide

الوصف: OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.

وصف الملف: text/html

الوصول الحر: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2003000500002Test

المؤلفون: EVORA, Paulo Roberto B., PEARSON, Paul J., OELTJEN, Marilyn, DISCIGIL, Berent, SCHAFF, Hartzell V.

المصدر: Brazilian Journal of Cardiovascular Surgery. October 1999 14(4)

مصطلحات موضوعية: Artérias mamárias/efeitos de drogas, Endotélio vascular/efeitos de drogas, Neurotransmissores/farmacologia, Autacóides/farmacologia, Anóxia/metabolismo, Óxido nítrico/metabolismo, Epoprostenol/metabolismo, Bioensaios

الوصف: Para estudos comparativos da reatividade vascular entre artéria mamária interna (AMI) canina direita e esquerda, realizaram-se experimentos "in vitro" utilizando-se banhos orgânicos ("organ chambers") e ensaios biológicos: 1) os produtos plaquetários ADP e 5-HT induziram, respectivamente, vasodilatação dependente e independente do endotélio; 2) os autacóides, bradicinina e histamina, também induziram vasodilatação, respectivamente, dependente e independente do endotélio; 3) o A23187, vasodilatador independente de receptor, induziu relaxamentos dependentes do endotélio; 4) dopamina, dobutamina, papaverina e a poli-L-arginina induziram vasodilatações independentes do endotélio; 5) a NOR induziu intensa vasoconstrição comparável à causada pelo KCI e pela endotelina; 6) em 83% de 24 ensaios, a liberação basal de NO foi maior na AMI esquerda, em comparação com a AMI direita; 7) ensaios biológicos de AMIs demonstraram a importância da PGI2 nas condições de hipóxia, uma vez que a indometacina aboliu vasodilatação adicional em resposta à hipóxia em condições de vasodilatação induzida pela liberação basal de NO; 8) não ocorreram diferenças significantes de resposta, comparando-se estudos realizados em AMIs direita e esquerda.

وصف الملف: text/html

الوصول الحر: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-76381999000400006Test

المؤلفون: SenthilKumar, Gopika, Katunaric, Boran, Zirgibel, Zachary, Lindemer, Brian, Jaramillo-Torres, Maria J., Bordas-Murphy, Henry, Schulz, Mary E., Pearson, Paul J., Freed, Julie K.

المصدر: Circulation Research ; volume 134, issue 1, page 81-96 ; ISSN 0009-7330 1524-4571

الوصف: Background: Elevated plasma ceramides and microvascular dysfunction both independently predict adverse cardiac events. Despite the known detrimental effects of ceramide on the microvasculature, evidence suggests that activation of the shear-sensitive, ceramide-forming enzyme NSmase (neutral sphingomyelinase) elicits formation of vasoprotective nitric oxide (NO). Here, we explore a novel hypothesis that acute ceramide formation through NSmase is necessary for maintaining NO signaling within the human microvascular endothelium. We further define the mechanism through which ceramide exerts beneficial effects and discern key mechanistic differences between arterioles from otherwise healthy adults (non–coronary artery disease [CAD]) and patients diagnosed with CAD. Methods: Human arterioles were dissected from discarded surgical adipose tissue (n=166), and vascular reactivity to flow and C2-ceramide was assessed. Shear-induced NO and mitochondrial hydrogen peroxide (H 2 O 2 ) production were measured in arterioles using fluorescence microscopy. H 2 O 2 fluorescence was assessed in isolated human umbilical vein endothelial cells. Results: Inhibition of NSmase in arterioles from otherwise healthy adults induced a switch from NO to NOX-2 (NADPH-oxidase 2)–dependent H 2 O 2 -mediated flow-induced dilation. Endothelial dysfunction was prevented by treatment with sphingosine-1-phosphate (S1P) and partially prevented by C2-ceramide and an agonist of S1P-receptor 1 (S1PR1); the inhibition of the S1P/S1PR1 signaling axis induced endothelial dysfunction via NOX-2. Ceramide increased NO production in arterioles from non-CAD adults, an effect that was diminished with inhibition of S1P/S1PR1/S1P-receptor 3 signaling. In arterioles from patients with CAD, inhibition of NSmase impaired the overall ability to induce mitochondrial H 2 O 2 production and subsequently dilate to flow, an effect not restored with exogenous S1P. Acute ceramide administration to arterioles from patients with CAD promoted H 2 O 2 as opposed to NO ...

الإتاحة: https://doi.org/10.1161/circresaha.123.323445Test

المؤلفون: Messiha, Heidi, Garster, Noelle, Lewandowski, David, Pearson, Paul J., Mohananey, Divyanshu

المصدر: CASE ; volume 7, issue 12, page 492-495 ; ISSN 2468-6441

مصطلحات موضوعية: General Medicine

الإتاحة: https://doi.org/10.1016Test/j.case.2023.09.004
https://api.elsevier.com/content/article/PII:S246864412300186X?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S246864412300186X?httpAccept=text/plainTest

المؤلفون: Seadler, Benjamin D., Joyce, David L., Zelten, James, Sweeney, Kevin, Wisgerhof, Taylor, Slettehaugh, Zoey, Yuan, Y. William, Tefft, Brandon J., Pearson, Paul J.

المصدر: Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery ; volume 19, issue 2, page 156-160 ; ISSN 1556-9845 1559-0879

الوصف: Objective: Here we report our preclinical, proof-of-concept testing to assess the ability of a novel device to correct mitral regurgitation. The Milwaukee Heart device aims to enable any cardiac surgeon to perform high-quality mitral valve repair using a standard annuloplasty ring with a crosshatch of microporous, monofilament suture. Methods: Hemodynamic, echocardiographic, and videographic data were collected at baseline, following induction of mitral regurgitation, and after repair using porcine hearts in an ex vivo biosimulator model. A commercially available cardiac prosthesis assessment platform was then used to assess the hydrodynamic characteristics of the study device. Results: Porcine biosimulator pressure and flow metrics exhibited successful correction of mitral regurgitation following device implantation with similar values to baseline. Hydrodynamic results yielded pressure gradients and an effective orifice area comparable to currently approved prostheses. Conclusions: The study device effectively reduced mitral valve regurgitation and improved hemodynamics in our preclinical model with similar biophysical metrics to currently approved devices. Future in vivo trials are needed to evaluate the efficacy, biocompatibility, and freedom from the most likely adverse events, such as device thrombosis, embolic events, and hemolysis.

الإتاحة: https://doi.org/10.1177/15569845241232685Test

المؤلفون: Pearson, Paul J.

مصطلحات موضوعية: 551.5142

الإتاحة: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436987Test

المؤلفون: Miles, Bryan, Durham, Lucian A, Kurman, Jonathan, Joyce, Lyle D, Johnstone, David W, Joyce, David, Pearson, Paul J

المصدر: The Texas Heart Institute Journal

مصطلحات موضوعية: Cytoreduction surgical procedures, extracorporeal membrane oxygenation, lung neoplasms, Aged, Bronchi, Bronchial Neoplasms, Humans, Male, Middle Aged, Retrospective Studies, Thoracic Surgical Procedures, Tomography, X-Ray Computed, Cardiology, Cardiovascular Diseases, Diseases, Medical Specialties, Medicine and Health Sciences

الوصف: Short-term extracorporeal membrane oxygenation is a useful adjunct to thoracic procedures. We report the cases of 2 middle-aged men who were supported with venovenous extracorporeal membrane oxygenation to facilitate tumor debulking and recanalization of the carina and mainstem bronchi. Neither patient had major complications or adverse events. These cases suggest that short-term extracorporeal membrane oxygenation is safe in patients undergoing complex resection or debulking of endobronchial lesions.

وصف الملف: application/pdf

العلاقة: https://digitalcommons.library.tmc.edu/texasheartinstituejournal/89Test; https://digitalcommons.library.tmc.edu/context/texasheartinstituejournal/article/1078/viewcontent/i1526_6702_48_3_e197111.pdfTest

الإتاحة: https://doi.org/10.14503/THIJ-19-7111Test
https://digitalcommons.library.tmc.edu/texasheartinstituejournal/89Test
https://digitalcommons.library.tmc.edu/context/texasheartinstituejournal/article/1078/viewcontent/i1526_6702_48_3_e197111.pdfTest

المؤلفون: Chaddha, Ashish, Mason, Peter J., Fasseas, Panayotis, Pearson, Paul J., Tyagi, Sudhi, Plambeck, Christopher, Garster, Noelle C., Dang, Geetanjali, Salinger, Michael H.

المساهمون: funding in support of this paper

المصدر: Structural Heart ; volume 5, issue 3, page 332-337 ; ISSN 2474-8706

مصطلحات موضوعية: Cardiology and Cardiovascular Medicine

الإتاحة: https://doi.org/10.1080/24748706.2021.1885771Test
https://api.elsevier.com/content/article/PII:S2474870622008260?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S2474870622008260?httpAccept=text/plainTest