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1.
Nat Protoc ; 16(10): 4650-4675, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34400840

RESUMO

Ca2+ handling within cardiac myocytes underpins coordinated contractile function within the beating heart. This protocol enables high spatial and temporal Ca2+ imaging of ex vivo multicellular myocardial strips. The endocardial surface is retained, and strips of 150-300-µm thickness are dissected, loaded with Ca2+ indicators and mounted within 1.5 h. A list of the equipment and reagents used and the key methodological aspects allowing the use of this technique on strips from any chamber of the mammalian heart are described. We have successfully used this protocol on human, pig and rat biopsy samples. On use of this protocol with intact endocardial endothelium, we demonstrated that the myocytes develop asynchronous spontaneous Ca2+ events, which can be ablated by electrically evoked Ca2+ transients, and subsequently redevelop spontaneously after cessation of stimulation. This protocol thus offers a rapid and reliable method for studying the Ca2+ signaling underpinning cardiomyocyte contraction, in both healthy and diseased tissue.


Assuntos
Sinalização do Cálcio , Miocárdio , Miócitos Cardíacos , Animais , Contração Miocárdica , Ratos , Suínos
2.
Cardiovasc Res ; 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34173824

RESUMO

AIMS: Coronary microvascular smooth muscle cells (SMCs) respond to luminal pressure by developing myogenic tone (MT), a process integral to the regulation of microvascular perfusion. The cellular mechanisms underlying poor myogenic reactivity in patients with heart valve disease are unknown and form the focus of this study. METHODS AND RESULTS: Intramyocardial coronary micro-arteries (IMCAs) isolated from human and pig right atrial appendage (RA) and left ventricular (LV) biopsies were studied using pressure myography combined with confocal microscopy. All RA- and LV-IMCAs from organ donors and pigs developed circa 25% MT. In contrast, 44% of human RA-IMCAs from 88 patients with heart valve disease had poor (<10%) MT yet retained cell viability and an ability to raise cytoplasmic Ca2+ in response to vasoconstrictor agents. Comparing across human heart chambers and species we found that based on patient medical history and six tests, the strongest predictor of poor MT in IMCAs was increased expression of the synthetic marker caldesmon relative to the contractile marker SM-myosin heavy chain. In addition, high resolution imaging revealed a distinct layer of longitudinally-aligned SMCs between ECs and radial SMCs, and we show poor MT was associated with disruptions in these cellular alignments. CONCLUSIONS: These data demonstrate the first use of atrial and ventricular biopsies from patients and pigs to reveal that impaired coronary MT reflects a switch of viable SMCs towards a synthetic phenotype, rather than a loss of SMC viability. These arteries represent a model for further studies of coronary microvascular contractile dysfunction.

3.
Cells ; 10(5)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067674

RESUMO

The cAMP analogue 8-Br-cAMP-AM (8-Br) confers marked protection against global ischaemia/reperfusion of isolated perfused heart. We tested the hypothesis that 8-Br is also protective under clinically relevant conditions (regional ischaemia) when applied either before ischemia or at the beginning of reperfusion, and this effect is associated with the mitochondrial permeability transition pore (MPTP). 8-Br (10 µM) was administered to Langendorff-perfused rat hearts for 5 min either before or at the end of 30 min regional ischaemia. Ca2+-induced mitochondria swelling (a measure of MPTP opening) and binding of hexokinase II (HKII) to mitochondria were assessed following the drug treatment at preischaemia. Haemodynamic function and ventricular arrhythmias were monitored during ischaemia and 2 h reperfusion. Infarct size was evaluated at the end of reperfusion. 8-Br administered before ischaemia attenuated ventricular arrhythmias, improved haemodynamic function, and reduced infarct size during ischaemia/reperfusion. Application of 8-Br at the end of ischaemia protected the heart during reperfusion. 8-Br promoted binding of HKII to the mitochondria and reduced Ca2+-induced mitochondria swelling. Thus, 8-Br protects the heart when administered before regional ischaemia or at the beginning of reperfusion. This effect is associated with inhibition of MPTP via binding of HKII to mitochondria, which may underlie the protective mechanism.


Assuntos
8-Bromo Monofosfato de Adenosina Cíclica/administração & dosagem , Fármacos Cardiovasculares/administração & dosagem , Mitocôndrias Cardíacas/efeitos dos fármacos , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , 8-Bromo Monofosfato de Adenosina Cíclica/análogos & derivados , Animais , Cálcio/metabolismo , Modelos Animais de Doenças , Esquema de Medicação , Hemodinâmica/efeitos dos fármacos , Hexoquinase/metabolismo , Preparação de Coração Isolado , Masculino , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Dilatação Mitocondrial/efeitos dos fármacos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos Wistar , Transdução de Sinais , Função Ventricular Esquerda/efeitos dos fármacos
4.
J Tissue Eng ; 12: 2041731420987529, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33854749

RESUMO

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

5.
J Neurochem ; 158(2): 105-118, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33675563

RESUMO

To evaluate the neuroprotection exerted by ketosis against acute damage of the mammalian central nervous system (CNS). Search engines were interrogated to identify experimental studies comparing the mitigating effect of ketosis (intervention) versus non-ketosis (control) on acute CNS damage. Primary endpoint was a reduction in mortality. Secondary endpoints were a reduction in neuronal damage and dysfunction, and an 'aggregated advantage' (composite of all primary and secondary endpoints). Hedges' g was the effect measure. Subgroup analyses evaluated the modulatory effect of age, insult type, and injury site. Meta-regression evaluated timing, type, and magnitude of intervention as predictors of neuroprotection. The selected publications were 49 experimental murine studies (period 1979-2020). The intervention reduced mortality (g 2.45, SE 0.48, p < .01), neuronal damage (g 1.96, SE 0.23, p < .01) and dysfunction (g 0.99, SE 0.10, p < .01). Reduction of mortality was particularly pronounced in the adult subgroup (g 2.71, SE 0.57, p < .01). The aggregated advantage of ketosis was stronger in the pediatric (g 3.98, SE 0.71, p < .01), brain (g 1.96, SE 0.18, p < .01), and ischemic insult (g 2.20, SE 0.23, p < .01) subgroups. Only the magnitude of intervention was a predictor of neuroprotection (g 0.07, SE 0.03, p 0.01 per every mmol/L increase in ketone levels). Ketosis exerts a potent neuroprotection against acute damage to the mammalian CNS in terms of reduction of mortality, of neuronal damage and dysfunction. Hematic levels of ketones are directly proportional to the effect size of neuroprotection.


Assuntos
Doenças do Sistema Nervoso Central/patologia , Cetose/patologia , Neuroproteção , Animais , Lesões Encefálicas Traumáticas/patologia , Dieta Cetogênica , Humanos
6.
Cardiovasc Res ; 117(4): 1188-1201, 2021 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-32766828

RESUMO

AIMS: Succinate accumulates several-fold in the ischaemic heart and is then rapidly oxidized upon reperfusion, contributing to reactive oxygen species production by mitochondria. In addition, a significant amount of the accumulated succinate is released from the heart into the circulation at reperfusion, potentially activating the G-protein-coupled succinate receptor (SUCNR1). However, the factors that determine the proportion of succinate oxidation or release, and the mechanism of this release, are not known. METHODS AND RESULTS: To address these questions, we assessed the fate of accumulated succinate upon reperfusion of anoxic cardiomyocytes, and of the ischaemic heart both ex vivo and in vivo. The release of accumulated succinate was selective and was enhanced by acidification of the intracellular milieu. Furthermore, pharmacological inhibition, or haploinsufficiency of the monocarboxylate transporter 1 (MCT1) significantly decreased succinate efflux from the reperfused heart. CONCLUSION: Succinate release upon reperfusion of the ischaemic heart is mediated by MCT1 and is facilitated by the acidification of the myocardium during ischaemia. These findings will allow the signalling interaction between succinate released from reperfused ischaemic myocardium and SUCNR1 to be explored.

7.
BMC Med Res Methodol ; 20(1): 300, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33302878

RESUMO

BACKGROUND: Typically, subgroup analyses in clinical trials are conducted by comparing the intervention effect in each subgroup by means of an interaction test. However, trials are rarely, if ever, adequately powered for interaction tests, so clinically important interactions may go undetected. We discuss the application of Bayesian methods by using expert opinions alongside the trial data. We applied this methodology to the VeRDiCT trial investigating the effect of preoperative volume replacement therapy (VRT) versus no VRT (usual care) in diabetic patients undergoing cardiac surgery. Two subgroup effects were of clinical interest, a) preoperative renal failure and b) preoperative type of antidiabetic medication. METHODS: Clinical experts were identified within the VeRDiCT trial centre in the UK. A questionnaire was designed to elicit opinions on the impact of VRT on the primary outcome of time from surgery until medically fit for hospital discharge, in the different subgroups. Prior beliefs of the subgroup effect of VRT were elicited face-to-face using two unconditional and one conditional questions per subgroup analysis. The robustness of results to the 'community of priors' was assessed. The community of priors was built using the expert priors for the mean average treatment effect, the interaction effect or both in a Bayesian Cox proportional hazards model implemented in the STAN software in R. RESULTS: Expert opinions were obtained from 7 clinicians (6 cardiac surgeons and 1 cardiac anaesthetist). Participating experts believed VRT could reduce the length of recovery compared to usual care and the greatest benefit was expected in the subgroups with the more severe comorbidity. The Bayesian posterior estimates were more precise compared to the frequentist maximum likelihood estimate and were shifted toward the overall mean treatment effect. CONCLUSIONS: In the VeRDiCT trial, the Bayesian analysis did not provide evidence of a difference in treatment effect across subgroups. However, this approach increased the precision of the estimated subgroup effects and produced more stable treatment effect point estimates than the frequentist approach. Trial methodologists are encouraged to prospectively consider Bayesian subgroup analyses when low-powered interaction tests are planned. TRIAL REGISTRATION: ISRCTN, ISRCTN02159606 . Registered 29th October 2008.


Assuntos
Prova Pericial , Teorema de Bayes , Ensaios Clínicos como Assunto , Humanos , Funções Verossimilhança , Modelos de Riscos Proporcionais , Inquéritos e Questionários
8.
PLoS One ; 15(12): e0242908, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33320865

RESUMO

PURPOSE: Volume indices and left ventricular ejection fraction (LVEF) are routinely used to assess cardiac function. Ventricular strain values may provide additional diagnostic information, but their reproducibility is unclear. This study therefore compares the repeatability and reproducibility of volumes, volume fraction, and regional ventricular strains, derived from cardiovascular magnetic resonance (CMR) imaging, across three software packages and between readers. METHODS: Seven readers analysed 16 short-axis CMR stacks of a porcine heart. Endocardial contours were manually drawn using OsiriX and Simpleware ScanIP and repeated in both softwares. The images were also contoured automatically in Circle CVI42. Endocardial global, apical, mid-ventricular, and basal circumferential strains, as well as end-diastolic and end-systolic volume and LVEF were compared. RESULTS: Bland-Altman analysis found systematic biases in contour length between software packages. Compared to OsiriX, contour lengths were shorter in both ScanIP (-1.9 cm) and CVI42 (-0.6 cm), causing statistically significant differences in end-diastolic and end-systolic volumes, and apical circumferential strain (all p<0.006). No differences were found for mid-ventricular, basal or global strains, or left ventricular ejection fraction (all p<0.007). All CVI42 results lay within the ranges of the OsiriX results. Intra-software differences were found to be lower than inter-software differences. CONCLUSION: OsiriX and CVI42 gave consistent results for all strain and volume metrics, with no statistical differences found between OsiriX and ScanIP for mid-ventricular, global or basal strains, or left ventricular ejection fraction. However, volumes were influenced by the choice of contouring software, suggesting care should be taken when comparing volumes across different software.


Assuntos
Ventrículos do Coração/anatomia & histologia , Ventrículos do Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética , Estresse Mecânico , Animais , Diástole , Processamento de Imagem Assistida por Computador , Tamanho do Órgão , Suínos , Sístole
9.
Indian J Thorac Cardiovasc Surg ; 36(6): 563-565, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33093751

RESUMO

The choice of ring for mitral valve repair is still largely left to the surgeon's preferences and there are no specific guidelines regulating this decision. Despite this previous researches have described important features appertaining to each of the different types of rings currently available. Particularly, the debate is still open in regards to the flexibility that these devices should or should not have. Later in this issue of the Journal, Panicker and colleagues have reported their results with flexible and rigid rings in mitral valve repair. The results are very interesting and once again are highlighting the importance of using the right ring for the right disease.

10.
Biomater Sci ; 8(16): 4467-4480, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32608409

RESUMO

Clinically available prosthetic heart valves are life-saving, but imperfect: mechanical valves requiring anticoagulation therapy, whilst bioprosthetic valves have limited durability. Polymer valves offer the prospect of good durability without the need for anticoagulation. We report the design and development of a polymeric heart valve, its bench-testing at ISO standards, and preliminary extra-vivo and in vivo short-term feasibility. Prototypes were manufactured by injection moulding of styrenic block copolymers to achieve anisotropic mechanical properties. Design was by finite element stress-strain modelling, which has been reported previously, combined with feedback from bench and surgery-based testing using various combinations of materials, valve geometry and processing conditions. Bench testing was according to ISO 5840:2015 standards using an in vitro cardiovascular hydrodynamic testing system and an accelerated fatigue tester. Bench comparisons were made with a best-in-class bio-prosthesis. Preliminary clinical feasibility evaluations included extra-vivo and short-term (1-24 hours) in vivo testing in a sheep model. The optimised final prototype met the requirements of ISO standards with hydrodynamic performance equivalent to the best-in-class bioprosthesis. Bench durability of greater than 1.2 billion cycles (30 years equivalent) was achieved (still ongoing). Extra-vivo sequential testing (n = 8) allowed refinement of external diameter, 3D shape, a low profile, flexibility, suturability, and testing of compatibility to magnetic resonance imaging and clinical sterilisation. In vivo short-term (1-24 hours) feasibility (n = 3) confirmed good suturability, no mechanical failure, no trans-valvular regurgitation, competitive trans-valvular gradients, and good biocompatibility at histopathology. We have developed and tested at ISO standards a novel prosthetic heart valve featuring competitive bench-based hydrodynamics and durability, well beyond the ISO requirements and comparable to a best-in-class bioprosthesis. In vivo short-term feasibility testing confirmed preliminary safety, functionality and biocompatibility, supporting progression to a long-term efficacy trial.


Assuntos
Bioprótese , Próteses Valvulares Cardíacas , Animais , Estudos de Viabilidade , Teste de Materiais , Polímeros , Desenho de Prótese , Ovinos
11.
Biomater Sci ; 8(16): 4639, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32725008

RESUMO

Correction for 'Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis' by Joanna R. Stasiak et al., Biomater. Sci., 2020, DOI: .

12.
Ann Thorac Surg ; 110(5): 1527-1533, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32277884

RESUMO

BACKGROUND: This study investigated the impact of combined degenerative mitral valve (DMV) and coronary artery bypass grafting (CABG+DMV) surgery vs DMV surgery only on in-hospital health outcome and 10-year survival. METHODS: We identified 745 patients with DMV disease. Of these, 186 (24.9%) were affected also by coronary disease and underwent combined DMV+CABG. They were compared with the remaining 559 patients receiving DMV-only surgery in in-hospital and 1-, 5-, and 10-year survival. We evaluated a short-term composite outcome of hospital mortality, acute kidney injury, cerebrovascular events, and low cardiac output requiring postoperative use of intraaortic balloon pump. In addition, we assessed mitral valve repair rates over time and their correlation with long-term survival. To minimize bias, we conducted a propensity score-matching analysis. RESULTS: DMV+CABG surgery was associated with a similar incidence of the composite end point compared with DMV-only surgery in the unmatched analysis (6.5% vs 5.4%, P = .71) and matched analysis (7.5% vs 8.2%, P = .82). The 10-year survival was 70.5% vs 68.6% (P = .07) for the unmatched analysis and 64.6% vs 62.5% (P = .9) for the matched analysis, DMV+CABG vs DMV-only, respectively. Mitral valve repair had a beneficial effect on short-term outcomes and long-term mortality rates, regardless the presence of concomitant coronary surgery. CONCLUSIONS: Combined DMV+CABG surgery is a very effective surgical treatment with high mitral valve repair rate. Early in-hospital outcome and long-term survival are comparable with DMV-only surgery. In these combined procedures, mitral valve repair is associated with better long-term survival.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Ponte de Artéria Coronária , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/cirurgia , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/cirurgia , Valva Mitral/cirurgia , Idoso , Terapia Combinada , Doença da Artéria Coronariana/mortalidade , Feminino , Doenças das Valvas Cardíacas/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
13.
Interact Cardiovasc Thorac Surg ; 30(1): 54-63, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539025

RESUMO

OBJECTIVES: To investigate the effect of preoperative volume replacement therapy (VRT) on renal function, health outcome and time to fitness for discharge in diabetic patients undergoing coronary artery bypass grafting (CABG). METHODS: In 2 parallel randomized controlled trials, diabetic patients were allocated to preoperative VRT (1 ml/kg/h of Hartmann's solution for 12 h) or usual care. Primary outcome was time to fitness for discharge. Secondary outcomes included acute kidney injury, postoperative complications, patient-reported quality of life (QoL), hospital resource use and markers of renal, cardiac and inflammatory injury. RESULTS: In total, 169 patients were randomized (84 VRT, 85 usual care; mean age 64 years; 88% male). Time to fitness for discharge was similar between groups [median 6 days; interquartile range 5.0-9.0 in both groups; hazard ratio 0.95, 95% confidence interval (CI) 0.65-1.38; P = 0.78]. Postoperative acute kidney injury was not statistically different (VRT: 27.7% vs usual care: 18.8%, odds ratio 1.72, 95% CI 0.82-3.59; P = 0.15). Estimated glomerular filtration rate (mean difference -0.92, 95% CI -4.18 to 2.25; P = 0.56), microalbumin/creatinine ratio [geometric mean ratio (GMR) 1.16, 95% CI 0.94-1.42; P = 0.16], N-acetyl-beta-d-glucosaminidase (GMR 1.08, 95% CI 0.83-1.40; P = 0.57), C-reactive protein (GMR 1.00, 95% CI 0.88-1.13; P = 0.94), troponin T (Trop-T; GMR 1.18, 95% CI 0.78-1.79; P = 0.39) and other secondary health outcomes were similar between groups. QoL improved in both groups at 3 months with no difference observed. CONCLUSIONS: The use of preoperative VRT is not superior to usual care in diabetic patients undergoing CABG. CLINICAL TRIAL REGISTRATION NUMBER: ISRCTN02159606.


Assuntos
Injúria Renal Aguda/prevenção & controle , Ponte de Artéria Coronária/efeitos adversos , Doença da Artéria Coronariana/cirurgia , Complicações do Diabetes/complicações , Hidratação/métodos , Complicações Pós-Operatórias/prevenção & controle , Injúria Renal Aguda/etiologia , Idoso , Doença da Artéria Coronariana/complicações , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Alta do Paciente , Complicações Pós-Operatórias/etiologia , Modelos de Riscos Proporcionais , Qualidade de Vida
14.
Neurobiol Stress ; 11: 100189, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31388518

RESUMO

The mechanisms underlying the protective effects of remote ischemic preconditioning (RIPC) are not presently clear. Recent studies in experimental models suggest the involvement of the autonomic nervous system (ANS) in cardioprotection. The aim of this study was to investigate the changes in ANS in healthy young volunteers divided into RIPC (n = 22) or SHAM (n = 18) groups. RIPC was induced by 1 cycle of 4 min inflation/5 min deflation followed by 2 cycles of 5 min inflation/5 min deflation of a cuff placed on the upper left limb. The study included analysis of heart rate (HR), blood pressure (BP), heart rate variability (HRV), measurements of microcirculation and porphyrin fluorescence in the limb before and after the RIPC. RIPC caused reactive hyperemia in the limb and reduced blood porphyrin level. A mental load (serial sevens test) and mild motor stress (hyperventilation) were performed on all subjects before and after RIPC or corresponding rest in the SHAM group. Reduction of HR occurred during the experiments in both RIPC and SHAM groups reflecting RIPC-independent adaptation of the subjects to the experimental procedure. However, in contrast to the SHAM group, RIPC altered several of the spectral indices of HRV during the serial sevens test and hyperventilation. This was expressed predominantly as an increase in power of the very low-frequency band of the spectrum, increased values of detrended fluctuation analysis and weakening of correlation between the HRV parameters and HR. In conclusion, RIPC induces changes in the activity of ANS that are linked to stress resistance.

15.
J Card Surg ; 34(6): 385-399, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31045289

RESUMO

OBJECTIVE: Pulmonary dysfunction is a common complication in patients undergoing heart surgery. Current clinical practice does not include any specific strategy for lung protection. To compare the anti-inflammatory effects of low-frequency ventilation (LFV), as measured by nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) p65 pathway activation, for the entire cardiopulmonary bypass (CPB) vs both lungs left collapsed in patients undergoing coronary artery bypass grafting (CABG). METHODS: Two groups parallel randomized controlled trial. The primary outcome was inflammation measured by NF-κB p65 activation in pre- and post-CPB lung biopsies. Secondary outcomes were additional inflammatory markers in both biopsy tissue and blood. RESULTS: Thirty-seven patients were randomly allocated to LFV (18) and to both lungs left collapsed (19). The mean concentration of NF-κB p65 in the biopsies before chest closure (adjusted for pre-CPB concentration) was higher in the LFV group compared to both lungs left collapsed group but this was not significant (0.102, 95% confidence interval, -0.022 to 0.226, P = 0.104). There were no significant differences between groups in the other inflammatory markers measured in tissue and blood. CONCLUSIONS: In patients undergoing elective CABG, the use of LFV during CPB when compared to both lungs left collapsed does not seem to reduce inflammation in lung biopsies and blood.


Assuntos
Ponte Cardiopulmonar , Ponte de Artéria Coronária , Complicações Intraoperatórias/prevenção & controle , Atelectasia Pulmonar/prevenção & controle , Respiração Artificial/métodos , Idoso , Biomarcadores/metabolismo , Feminino , Humanos , Inflamação/diagnóstico , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/patologia , Pulmão/metabolismo , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Atelectasia Pulmonar/diagnóstico , Atelectasia Pulmonar/patologia , Fator de Transcrição RelA/metabolismo
16.
Eur Heart J ; 40(24): 1920-1929, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-30859228

RESUMO

AIMS: The co-transmitter neuropeptide-Y (NPY) is released during high sympathetic drive, including ST-elevation myocardial infarction (STEMI), and can be a potent vasoconstrictor. We hypothesized that myocardial NPY levels correlate with reperfusion and subsequent recovery following primary percutaneous coronary intervention (PPCI), and sought to determine if and how NPY constricts the coronary microvasculature. METHODS AND RESULTS: Peripheral venous NPY levels were significantly higher in patients with STEMI (n = 45) compared to acute coronary syndromes/stable angina ( n = 48) or with normal coronary arteries (NC, n = 16). Overall coronary sinus (CS) and peripheral venous NPY levels were significantly positively correlated (r = 0.79). STEMI patients with the highest CS NPY levels had significantly lower coronary flow reserve, and higher index of microvascular resistance measured with a coronary flow wire. After 2 days they also had significantly higher levels of myocardial oedema and microvascular obstruction on cardiac magnetic resonance imaging, and significantly lower ejection fractions and ventricular dilatation 6 months later. NPY (100-250 nM) caused significant vasoconstriction of rat microvascular coronary arteries via increasing vascular smooth muscle calcium waves, and also significantly increased coronary vascular resistance and infarct size in Langendorff hearts. These effects were blocked by the Y1 receptor antagonist BIBO3304 (1 µM). Immunohistochemistry of the human coronary microvasculature demonstrated the presence of vascular smooth muscle Y1 receptors. CONCLUSION: High CS NPY levels immediately after reperfusion correlate with microvascular dysfunction, greater myocardial injury, and reduced ejection fraction 6 months after STEMI. NPY constricts the coronary microcirculation via the Y1 receptor, and antagonists may be a useful PPCI adjunct therapy.


Assuntos
Vasos Coronários/fisiopatologia , Microcirculação/fisiologia , Neuropeptídeo Y/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/metabolismo , Síndrome Coronariana Aguda/metabolismo , Síndrome Coronariana Aguda/fisiopatologia , Idoso , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Estudos de Casos e Controles , Constrição , Seio Coronário/metabolismo , Estenose Coronária/metabolismo , Edema/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Ratos , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Volume Sistólico/fisiologia , Resistência Vascular/fisiologia , Disfunção Ventricular Esquerda/fisiopatologia
17.
Biochem Biophys Res Commun ; 512(4): 684-690, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-30922569

RESUMO

Inhibition of SK channel function is being pursued in animal models as a possible therapeutic approach to treat atrial fibrillation (AF). However, the pharmacology of SK channels in human atria is unclear. SK channel function is inhibited by both apamin and UCL1684, with the former discriminating between SK channel subtypes. In this proof-of-principle study, the effects of apamin and UCL1684 on right atrial myocytes freshly isolated from patients in sinus rhythm undergoing elective cardiac surgery were investigated. Outward current evoked from voltage clamped human atrial myocytes was reduced by these two inhibitors of SK channel function. In contrast, membrane current underlying the atrial action potential was affected significantly only by UCL1684 and not by apamin. This pharmacology mirrors that observed in mouse atria, suggesting that mammalian atria possess two populations of SK channels, with only one population contributing to the action potential waveform. Immuno-visualization of the subcellular localization of SK2 and SK3 subunits showed a high degree of colocalization, consistent with the formation of heteromeric SK2/SK3 channels. These data reveal that human atrial myocytes express two SK channel subtypes, one exhibiting an unusual pharmacology. These channels contribute to the atrial action potential waveform and might be a target for novel therapeutic approaches to treat supraventricular arrhythmic conditions such as atrial fibrillation.


Assuntos
Potenciais de Ação , Átrios do Coração/citologia , Miócitos Cardíacos/citologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Células Cultivadas , Átrios do Coração/metabolismo , Humanos , Miócitos Cardíacos/metabolismo , Multimerização Proteica , Canais de Potássio Ativados por Cálcio de Condutância Baixa/análise
18.
Hum Genomics ; 13(1): 6, 2019 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-30704525

RESUMO

BACKGROUND: Mitochondrial DNA copy number (mtDNA CN) exhibits interindividual and intercellular variation, but few genome-wide association studies (GWAS) of directly assayed mtDNA CN exist. We undertook a GWAS of qPCR-assayed mtDNA CN in the Avon Longitudinal Study of Parents and Children (ALSPAC) and the UK Blood Service (UKBS) cohort. After validating and harmonising data, 5461 ALSPAC mothers (16-43 years at mtDNA CN assay) and 1338 UKBS females (17-69 years) were included in a meta-analysis. Sensitivity analyses restricted to females with white cell-extracted DNA and adjusted for estimated or assayed cell proportions. Associations were also explored in ALSPAC children and UKBS males. RESULTS: A neutrophil-associated locus approached genome-wide significance (rs709591 [MED24], ß (change in SD units of mtDNA CN per allele) [SE] - 0.084 [0.016], p = 1.54e-07) in the main meta-analysis of adult females. This association was concordant in magnitude and direction in UKBS males and ALSPAC neonates. SNPs in and around ABHD8 were associated with mtDNA CN in ALSPAC neonates (rs10424198, ß [SE] 0.262 [0.034], p = 1.40e-14), but not other study groups. In a meta-analysis of unrelated individuals (N = 11,253), we replicated a published association in TFAM (ß [SE] 0.046 [0.017], p = 0.006), with an effect size much smaller than that observed in the replication analysis of a previous in silico GWAS. CONCLUSIONS: In a hypothesis-generating GWAS, we confirm an association between TFAM and mtDNA CN and present putative loci requiring replication in much larger samples. We discuss the limitations of our work, in terms of measurement error and cellular heterogeneity, and highlight the need for larger studies to better understand nuclear genomic control of mtDNA copy number.


Assuntos
Variações do Número de Cópias de DNA , DNA Mitocondrial/genética , Estudo de Associação Genômica Ampla/métodos , Adolescente , Adulto , Criança , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
19.
J Thorac Cardiovasc Surg ; 158(2): 406-407, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30661813
20.
J Am Heart Assoc ; 7(2)2018 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-29358198

RESUMO

BACKGROUND: Transplantation of adventitial pericytes (APCs) promotes cardiac repair in murine models of myocardial infarction. The aim of present study was to confirm the benefit of APC therapy in a large animal model. METHODS AND RESULTS: We performed a blind, randomized, placebo-controlled APC therapy trial in a swine model of reperfused myocardial infarction. A first study used human APCs (hAPCs) from patients undergoing coronary artery bypass graft surgery. A second study used allogeneic swine APCs (sAPCs). Primary end points were (1) ejection fraction as assessed by cardiac magnetic resonance imaging and (2) myocardial vascularization and fibrosis as determined by immunohistochemistry. Transplantation of hAPCs reduced fibrosis but failed to improve the other efficacy end points. Incompatibility of the xenogeneic model was suggested by the occurrence of a cytotoxic response following in vitro challenge of hAPCs with swine spleen lymphocytes and the failure to retrieve hAPCs in transplanted hearts. We next considered sAPCs as an alternative. Flow cytometry, immunocytochemistry, and functional/cytotoxic assays indicate that sAPCs are a surrogate of hAPCs. Transplantation of allogeneic sAPCs benefited capillary density and fibrosis but did not improve cardiac magnetic resonance imaging indices of contractility. Transplanted cells were detected in the border zone. CONCLUSIONS: Immunologic barriers limit the applicability of a xenogeneic swine model to assess hAPC efficacy. On the other hand, we newly show that transplantation of allogeneic sAPCs is feasible, safe, and immunologically acceptable. The approach induces proangiogenic and antifibrotic benefits, though these effects were not enough to result in functional improvements.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Infarto do Miocárdio/cirurgia , Traumatismo por Reperfusão Miocárdica/cirurgia , Miocárdio/patologia , Neovascularização Fisiológica , Pericitos/transplante , Função Ventricular Esquerda , Remodelação Ventricular , Idoso , Idoso de 80 Anos ou mais , Células Alógenas , Animais , Células Cultivadas , Modelos Animais de Doenças , Feminino , Fibrose , Xenoenxertos , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Recuperação de Função Fisiológica , Volume Sistólico , Sus scrofa , Transplante Homólogo
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