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Coronary atherosclerosis is caused by plaque build-up, with lipids playing a pivotal role in its progression. However, lipid composition and distribution within coronary atherosclerosis remain unknown. This study aims to characterize lipids and investigate differences in lipid composition across disease stages to aid in the understanding of disease progression. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to visualize lipid distributions in coronary artery sections (n = 17) from hypercholesterolemic swine. We performed histology on consecutive sections to classify the artery segments and to investigate colocalization between lipids and histological regions of interest in advanced plaque, including necrotic core and inflammatory cells. Segments were classified as healthy (n = 6), mild (n = 6), and advanced disease (n = 5) artery segments. Multivariate data analysis was employed to find differences in lipid composition between the segment types, and the lipids' spatial distribution was investigated using non-negative matrix factorization (NMF). Through this process, MALDI-MSI detected 473 lipid-related features. NMF clustering described three components in positive ionization mode: triacylglycerides (TAG), phosphatidylcholines (PC), and cholesterol species. In negative ionization mode, two components were identified: one driven by phosphatidylinositol(PI)(38:4), and one driven by ceramide-phosphoethanolamine(36:1). Multivariate data analysis showed the association between advanced disease and specific lipid signatures like PC(O-40:5) and cholesterylester(CE)(18:2). Ether-linked phospholipids and LysoPC species were found to colocalize with necrotic core, and mostly CE, ceramide, and PI species colocalized with inflammatory cells. This study, therefore, uncovers distinct lipid signatures correlated with plaque development and their colocalization with necrotic core and inflammatory cells, enhancing our understanding of coronary atherosclerosis progression.
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Enfermedad de la Arteria Coronaria , Hiperlipoproteinemia Tipo II , Placa Aterosclerótica , Animales , Porcinos , Lipidómica , Ceramidas , Necrosis , Fosfatidilcolinas , Éteres Fosfolípidos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
PURPOSE: The composition of thrombi retrieved during endovascular thrombectomy (EVT) in acute ischemic stroke (AIS) due to large vessel occlusion (LVO) may differ depending on their origin. In this study, we investigated the association between thrombus composition and stroke etiology in a large population of patients from the Dutch MR CLEAN Registry treated with EVT in daily clinical practice. METHODS: The thrombi of 332 patients with AIS were histologically analyzed for red blood cells (RBC), fibrin/platelets (F/P), and white blood cells (leukocytes) using a machine learning algorithm. Stroke etiology was assessed using the Trial of Org 10,172 in acute stroke treatment (TOAST) classification. RESULTS: The thrombi of cardioembolic origin contained less RBC and more F/P than those of non-cardioembolic origin (25.8% vs 41.2% RBC [p = 0.003] and 67.1% vs 54.5% F/P [p = 0.004]). The likelihood of a non-cardioembolic source of stroke increased with increasing thrombus RBC content (OR 1.02; [95% CI 1.00-1.06] for each percent increase) and decreased with a higher F/P content (OR 1.02; [95% CI 1.00-1.06]). Thrombus composition in patients with a cardioembolic origin and undetermined origin was similar. CONCLUSION: Thrombus composition is significantly associated with stroke etiology, with an increase in RBC and a decrease in F/P raising the odds for a non-cardioembolic cause. No difference between composition of cardioembolic thrombi and of undetermined origin was seen. This emphasizes the need for more extensive monitoring for arrhythmias and/or extended cardiac analysis in case of an undetermined origin.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Trombosis , Humanos , Isquemia Encefálica/etiología , Bancos de Muestras Biológicas , Accidente Cerebrovascular/etiología , Trombosis/complicaciones , Trombosis/patología , Trombectomía/efectos adversos , Sistema de RegistrosRESUMEN
Translation of acute ischemic stroke research to the clinical setting remains limited over the last few decades with only one drug, recombinant tissue-type plasminogen activator, successfully completing the path from experimental study to clinical practice. To improve the selection of experimental treatments before testing in clinical studies, the use of large gyrencephalic animal models of acute ischemic stroke has been recommended. Currently, these models include, among others, dogs, swine, sheep, and nonhuman primates that closely emulate aspects of the human setting of brain ischemia and reperfusion. Species-specific characteristics, such as the cerebrovascular architecture or pathophysiology of thrombotic/ischemic processes, significantly influence the suitability of a model to address specific research questions. In this article, we review key characteristics of the main large animal models used in translational studies of acute ischemic stroke, regarding (1) anatomy and physiology of the cerebral vasculature, including brain morphology, coagulation characteristics, and immune function; (2) ischemic stroke modeling, including vessel occlusion approaches, reproducibility of infarct size, procedural complications, and functional outcome assessment; and (3) implementation aspects, including ethics, logistics, and costs. This review specifically aims to facilitate the selection of the appropriate large animal model for studies on acute ischemic stroke, based on specific research questions and large animal model characteristics.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Animales , Isquemia Encefálica/terapia , Modelos Animales de Enfermedad , Perros , Humanos , Reproducibilidad de los Resultados , Ovinos , Porcinos , Activador de Tejido PlasminógenoRESUMEN
OBJECTIVES: Thrombus computed tomography (CT) characteristics might be used to assess histopathologic thrombus composition in patients treated with endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). We aimed to assess the variability in thrombus composition that could be predicted with combined thrombus CT characteristics. METHODS: Thrombi of patients enrolled in the MR CLEAN Registry between March 2014 and June 2016 were histologically analyzed with hematoxylin-eosin staining and quantified for percentages of red blood cells (RBCs) and fibrin/platelets. We estimated the association between general qualitative characteristics (hyperdense artery sign [HAS], occlusion location, clot burden score [CBS]) and thrombus composition with linear regression, and quantified RBC variability that could be explained with individual and combined characteristics with R2. For patients with available thin-slice (≤ 2.5 mm) imaging, we performed similar analyses for general and quantitative characteristics (HAS, occlusion location, CBS, [relative] thrombus density, thrombus length, perviousness, distance from ICA-terminus). RESULTS: In 332 included patients, the presence of HAS (aß 7.8 [95% CI 3.9-11.7]) and shift towards a more proximal occlusion location (aß 3.9 [95% CI 0.6-7.1]) were independently associated with increased RBC and decreased fibrin/platelet content. With general characteristics, 12% of RBC variability could be explained; HAS was the strongest predictor. In 94 patients with available thin-slice imaging, 30% of RBC variability could be explained; thrombus density and thrombus length were the strongest predictors. CONCLUSIONS: Quantitative thrombus CT characteristics on thin-slice admission CT improve prediction of thrombus composition and might be used to further guide clinical decision-making in patients treated with EVT for AIS in the future. KEY POINTS: ⢠With hyperdense artery sign and occlusion location, 12% of variability in thrombus RBC content can be explained. ⢠With hyperdense artery sign, occlusion location, and quantitative thrombus characteristics on thin-slice (≤ 2.5 mm) non-contrast CT and CTA, 30% of variability in thrombus RBC content can be explained. ⢠Absolute thrombus density and thrombus length were the strongest predictors for thrombus composition.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Trombosis , Humanos , Accidente Cerebrovascular/patología , Trombectomía/métodos , Trombosis/diagnóstico por imagen , Trombosis/patología , Tomografía Computarizada por Rayos X , Sistema de Registros , FibrinaRESUMEN
Carotid atherosclerosis is a risk factor for ischemic stroke, one of the main causes of mortality and disability worldwide. The disease is characterized by plaques, heterogeneous deposits of lipids, and necrotic debris in the vascular wall, which grow gradually and may remain asymptomatic for decades. However, at some point a plaque can evolve to a high-risk plaque phenotype, which may trigger a cerebrovascular event. Lipids play a key role in the development and progression of atherosclerosis, but the nature of their involvement is not fully understood. Using matrix-assisted laser desorption/ionization mass spectrometry imaging, we visualized the distribution of approximately 200 different lipid signals, originating of >90 uniquely assigned species, in 106 tissue sections of 12 human carotid atherosclerotic plaques. We performed unsupervised classification of the mass spectrometry dataset, as well as a histology-directed multivariate analysis. These data allowed us to extract the spatial lipid patterns associated with morphological plaque features in advanced plaques from a symptomatic population, revealing spatial lipid patterns in atherosclerosis and their relation to histological tissue type. The abundances of sphingomyelin and oxidized cholesteryl ester species were elevated specifically in necrotic intima areas, whereas diacylglycerols and triacylglycerols were spatially correlated to areas containing the coagulation protein fibrin. These results demonstrate a clear colocalization between plaque features and specific lipid classes, as well as individual lipid species in high-risk atherosclerotic plaques.
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Enfermedades de las Arterias CarótidasRESUMEN
Background and Purpose: Mechanical properties of thromboemboli play an important role in the efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke. However, very limited data on mechanical properties of human stroke thrombi are available. We aimed to mechanically characterize thrombi retrieved with EVT, and to assess the relationship between thrombus composition and thrombus stiffness. Methods: Forty-one thrombi from 19 patients with acute stroke who underwent EVT between July and October 2019 were mechanically analyzed, directly after EVT. We performed unconfined compression experiments and determined tangent modulus at 75% strain (Et75) as a measure for thrombus stiffness. Thrombi were histologically analyzed for fibrin/platelets, erythrocytes, leukocytes, and platelets, and we assessed the relationship between histological components and Et75 with univariable and multivariable linear mixed regression. Results: Median Et75 was 560 (interquartile range, 3931161) kPa. In the multivariable analysis, fibrin/platelets were associated with increased Et75 (aß, 9 [95% CI, 5 to 13]) kPa, erythrocytes were associated with decreased Et75% (aß, −9 [95% CI, −5 to −13]) kPa. We found no association between leukocytes and Et75. High platelet values were strongly associated with increased Et75 (aß, 56 [95% CI, 3873]). Conclusions: Fibrin/platelet content of thrombi retrieved with EVT for acute ischemic stroke is strongly associated with increased thrombus stiffness. For thrombi with high platelet values, there was a very strong relationship with thrombus stiffness. Our data provide a basis for future research on the development of next-generation EVT devices tailored to thrombus composition.
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Fenómenos Biomecánicos/fisiología , Isquemia Encefálica/cirugía , Procedimientos Endovasculares/métodos , Accidente Cerebrovascular Isquémico/cirugía , Trombectomía/métodos , Trombosis/cirugía , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Procedimientos Endovasculares/instrumentación , Femenino , Humanos , Accidente Cerebrovascular Isquémico/patología , Accidente Cerebrovascular Isquémico/fisiopatología , Masculino , Persona de Mediana Edad , Trombectomía/instrumentación , Trombosis/patología , Trombosis/fisiopatologíaRESUMEN
We previously identified genomic instability as a causative factor for vascular aging. In the present study, we determined which vascular aging outcomes are due to local endothelial DNA damage, which was accomplished by genetic removal of ERCC1 (excision repair cross-complementation group 1) DNA repair in mice (EC-knockout (EC-KO) mice). EC-KO showed a progressive decrease in microvascular dilation of the skin, increased microvascular leakage in the kidney, decreased lung perfusion, and increased aortic stiffness compared with wild-type (WT). EC-KO showed expression of DNA damage and potential senescence marker p21 exclusively in the endothelium, as demonstrated in aorta. Also the kidney showed p21-positive cells. Vasodilator responses measured in organ baths were decreased in aorta, iliac and coronary artery EC-KO compared with WT, of which coronary artery was the earliest to be affected. Nitric oxide-mediated endothelium-dependent vasodilation was abolished in aorta and coronary artery, whereas endothelium-derived hyperpolarization and responses to exogenous nitric oxide (NO) were intact. EC-KO showed increased superoxide production compared with WT, as measured in lung tissue, rich in endothelial cells (ECs). Arterial systolic blood pressure (BP) was increased at 3 months, but normal at 5 months, at which age cardiac output (CO) was decreased. Since no further signs of cardiac dysfunction were detected, this decrease might be an adaptation to prevent an increase in BP. In summary, a selective DNA repair defect in the endothelium produces features of age-related endothelial dysfunction, largely attributed to loss of endothelium-derived NO. Increased superoxide generation might contribute to the observed changes affecting end organ perfusion, as demonstrated in kidney and lung.
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Envejecimiento/genética , Senescencia Celular/genética , Daño del ADN , Reparación del ADN , Proteínas de Unión al ADN/deficiencia , Endonucleasas/deficiencia , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Factores de Edad , Envejecimiento/metabolismo , Envejecimiento/patología , Animales , Permeabilidad Capilar , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Proteínas de Unión al ADN/genética , Endonucleasas/genética , Células Endoteliales/patología , Endotelio Vascular/patología , Endotelio Vascular/fisiopatología , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Superóxidos/metabolismo , Rigidez Vascular , VasodilataciónRESUMEN
We demonstrate a tethered motorized capsule for unobstructed optical coherence tomography (OCT) imaging of the esophagus. By using a distal reflector design, we avoided the common shadow artifact induced by the motor wires. A synchronous driving technique features three types of beam-scanning modes of the capsule, i.e., circumferential beam scanning, localized beam scanning, and accurate beam positioning. We characterized these three modes and carried out ex vivo imaging experiments using the capsule. The results show that the capsule can potentially be a useful tool for diagnostic OCT imaging and OCT-guided biopsy and therapy of the esophagus.
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PURPOSE: The increasing prevalence of obesity or metabolic syndrome (O/MS) and type 2 diabetes mellitus (DM) remains a global health concern. Clinically relevant and practical translational models mimicking human characteristics of these conditions are lacking. This study aimed to demonstrate proof of concept of the induction of stable O/MS and type 2 DM in a Göttingen minipig model and validate both of these disease-adjusted Göttingen minipig models as impaired healing models for the testing of dental implants. MATERIALS AND METHODS: Nine minipigs were split into 3 groups-control (normal diet), obese (cafeteria diet), and diabetic (cafeteria diet plus low-dosage streptozotocin)-followed by placement of dental implants. Inflammatory markers including tumor necrosis factor α, C-reactive protein, and cortisol were recorded for each study group. Removal torque was measured, and histomorphometric analysis (bone-to-implant contact and bone area fraction occupancy) was performed. RESULTS: O/MS pigs showed, on average, a 2-fold increase in plasma C-reactive protein (P < .05) and cortisol (P < .09) concentrations compared with controls; DM pigs showed, on average approximately, a 40-fold increase in plasma tumor necrosis factor α levels (P < .05) and a 2-fold increase in cortisol concentrations (P < .05) compared with controls. The impact of O/MS and DM on implants was determined. The torque to interface failure was highest in the control group (200 N-cm) and significantly lower in the O/MS (90 N-cm) and DM (60 N-cm) groups (P < .01). Bone formation around implants was significantly greater in the control group than in the O/MS and DM groups (P < .02). CONCLUSIONS: Both O/MS and DM minipigs express a human-like disease phenotype, and both presented bone-healing impairment around dental implants. Our finding of no significant difference between type 2 DM and O/MS in bone formation around implants provides evidence that further investigation of the impact of O/MS is warranted.
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Implantes Dentales , Diabetes Mellitus Tipo 2/fisiopatología , Síndrome Metabólico/fisiopatología , Oseointegración/fisiología , Animales , Biomarcadores/sangre , Modelos Animales de Enfermedad , Fenotipo , Proyectos Piloto , Prueba de Estudio Conceptual , Porcinos , Porcinos Enanos , Cicatrización de Heridas/fisiologíaRESUMEN
In Western countries heart disease is the leading cause of maternal death during pregnancy. The effect of pregnancy on the heart is difficult to study in patients with preexisting heart disease. Since experimental studies are scarce, we investigated the effect of pressure overload, produced by transverse aortic constriction (TAC) in mice, on the ability to conceive, pregnancy outcome, and maternal cardiac structure and function. Four weeks of TAC produced left ventricular (LV) hypertrophy and dysfunction with marked interstitial fibrosis, decreased capillary density, and induced pathological cardiac gene expression. Pregnancy increased relative LV and right ventricular weight without affecting the deterioration of LV function following TAC. Surprisingly, the TAC-induced increase in relative heart and lung weight was mitigated by pregnancy, which was accompanied by a trend towards normalization of capillary density and natriuretic peptide type A expression. Additionally, the combination of pregnancy and TAC increased the cardiac phosphorylation of c-Jun, and STAT1, but reduced phosphoinositide 3-kinase phosphorylation. Finally, TAC did not significantly affect conception rate, pregnancy duration, uterus size, litter size, and pup weight. In conclusion, we found that, rather than exacerbating the changes associated with cardiac pressure overload, pregnancy actually attenuated pathological LV remodeling and mitigated pulmonary congestion, and pathological gene expression produced by TAC, suggesting a positive effect of pregnancy on the pressure-overloaded heart.
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Estenosis de la Válvula Aórtica/fisiopatología , Hipertrofia Ventricular Izquierda/fisiopatología , Complicaciones Cardiovasculares del Embarazo/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Animales , Animales Recién Nacidos , Estenosis de la Válvula Aórtica/complicaciones , Factor Natriurético Atrial/genética , Peso al Nacer , Capilares/patología , Modelos Animales de Enfermedad , Ecocardiografía , Femenino , Fibrosis , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/genética , Hipertrofia Ventricular Izquierda/patología , Tamaño de la Camada , Ratones , Ratones Endogámicos C57BL , Miocardio/patología , Cadenas Pesadas de Miosina/genética , Péptido Natriurético Encefálico/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Embarazo , Complicaciones Cardiovasculares del Embarazo/etiología , Complicaciones Cardiovasculares del Embarazo/genética , Complicaciones Cardiovasculares del Embarazo/patología , Índice de Embarazo , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Transcripción STAT1/metabolismo , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/genética , Factores de Tiempo , Transcriptoma , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/genética , Disfunción Ventricular Izquierda/patologíaRESUMEN
Angiogenesis induced by growth factor-releasing microspheres can be an off-the-shelf and immediate alternative to stem cell therapy for acute myocardial infarction (AMI), independent of stem cell yield and comorbidity-induced dysfunction. Reliable and prolonged local delivery of intact proteins such as VEGF is, however, notoriously difficult. Our objective was to create a platform for local angiogenesis in human-sized hearts, using polyethylene-glycol/polybutylene-terephthalate (PEG-PBT) microsphere-based VEGF165A delivery. PEG-PBT microspheres were biocompatible, distribution was size dependent, and a regimen of 10 × 10(6) 15-µm microspheres at 0.5 × 10(6)/min did not induce cardiac necrosis. Efficacy, studied in a porcine model of AMI with reperfusion rather than chronic ischemia used for most reported VEGF studies, shows that microspheres were retained for at least 35 days. Acute VEGF165A release attenuated early cytokine release upon reperfusion and produced a dose-dependent increase in microvascular density at 5 wk following AMI. However, it did not improve major variables for global cardiac function, left ventricular dimensions, infarct size, or scar composition (collagen and myocyte content). Taken together, controlled VEGF165A delivery is safe, attenuates early cytokine release, and leads to a dose-dependent increase in microvascular density in the infarct zone but does not translate into changes in global or regional cardiac function and scar composition.
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Citocinas/sangre , Microesferas , Infarto del Miocardio/tratamiento farmacológico , Neovascularización Fisiológica , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , Función Ventricular , Animales , Células Cultivadas , Femenino , Humanos , Masculino , Microvasos/fisiología , Poliésteres/química , Polietilenglicoles/química , Porcinos , Factor A de Crecimiento Endotelial Vascular/administración & dosificación , Factor A de Crecimiento Endotelial Vascular/efectos adversos , Factor A de Crecimiento Endotelial Vascular/farmacocinéticaRESUMEN
Vagal nerve stimulation (VNS) started prior to, or during, ischemia has been shown to reduce infarct size. Here, we investigated the effect of VNS when started just prior to, and continued during early, reperfusion on infarct size and no-reflow and studied the underlying mechanisms. For this purpose, swine (13 VNS, 10 sham) underwent 45 min mid-LAD occlusion followed by 120 min of reperfusion. VNS was started 5 min prior to reperfusion and continued until 15 min of reperfusion. Area at risk, area of no-reflow (% of infarct area) and infarct size (% of area at risk), circulating cytokines, and regional myocardial leukocyte influx were assessed after 120 min of reperfusion. VNS significantly reduced infarct size from 67 ± 2 % in sham to 54 ± 5 % and area of no-reflow from 54 ± 6 % in sham to 32 ± 6 %. These effects were accompanied by reductions in neutrophil (~40 %) and macrophage (~60 %) infiltration in the infarct area (all p < 0.05), whereas systemic circulating plasma levels of TNFα and IL6 were not affected. The degree of cardioprotection could not be explained by the VNS-induced bradycardia or the VNS-induced decrease in the double product of heart rate and left ventricular systolic pressure. In the presence of NO-synthase inhibitor LNNA, VNS no longer attenuated infarct size and area of no-reflow, which was paralleled by similarly unaffected regional leukocyte infiltration. In conclusion, VNS is a promising novel adjunctive therapy that limits reperfusion injury in a large animal model of acute myocardial infarction.
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Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/prevención & control , Daño por Reperfusión Miocárdica/fisiopatología , Estimulación del Nervio Vago/métodos , Animales , Modelos Animales de Enfermedad , Femenino , Masculino , Sus scrofaRESUMEN
BACKGROUND AND STUDY AIMS: Hemospray (Cook Medical Inc., Winston-Salem, North Carolina, USA) is a novel, hemostatic, powder spray that has been developed for gastrointestinal use. The powder is thought to achieve hemostasis by concentrating clotting factors and forming a mechanical plug on the injured blood vessel. However, no detailed studies on the hemostatic mode of action have been performed. The aim of this study was to examine the effects of Hemospray on coagulation and clot formation both in vitro and in vivo. MATERIALS AND METHODS: Recalcification time, thromboelastometry using EXTEM and INTEM assays, and plasma coagulation tests (activated partial thromboplastin time and prothrombin time) were carried out on blood samples mixed with Hemospray, and compared with talcum powder (negative control) and kaolin (positive control) at 1âmg/mL and 10âmg/mL. Scanning electron microscopy (SEM) and light microscopy were performed on in vitro thrombi and on gastric thrombi from an animal model of gastrointestinal hemorrhage treated with Hemospray. RESULTS: The median recalcification time of whole blood was 187.5 seconds. The addition of 1âmg/mL and 10âmg/mL Hemospray significantly shortened this time (median 60 and 45 seconds, respectively; Pâ<â0.05). The median clotting time of whole blood, measured using the INTEM assay, was 160 seconds (interquartile range [IQR] 159â-â176.5) and this was also significantly reduced by the addition of Hemospray (91 seconds [IQR 84â-â102]; Pâ=â0.005). The plasma prothrombin time of 11.6 seconds was significantly reduced by Hemospray (9.5 seconds; Pâ=â0.011). SEM of in vivo clots demonstrated that Hemospray rapidly interacted with whole blood, forming one confluent mass over the bleeding site. In sufficient amounts, Hemospray was able to deform and pack erythrocytes. CONCLUSIONS: Hemospray covered the bleeding site and enhanced clot formation in vivo, and shortened coagulation time in vitro. Elaboration of these unique properties in clinical practice will help to optimize future endoscopic hemostasis with Hemospray.
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Coagulación Sanguínea/efectos de los fármacos , Hemorragia Gastrointestinal/tratamiento farmacológico , Hemostáticos/farmacología , Minerales/farmacología , Adulto , Animales , Pruebas de Coagulación Sanguínea , Femenino , Hemostáticos/uso terapéutico , Humanos , Masculino , Microscopía Electrónica de Rastreo , Minerales/uso terapéutico , Sus scrofa , TromboelastografíaRESUMEN
Futile recanalization hampers prognoses of ischemic stroke after successful mechanical thrombectomy, hypothetically through post-recanalization perfusion deficits, onset-to-groin delays and sex effects. Clinically, acute multiparametric imaging studies remain challenging. We assessed possible relationships between these factors and disease outcome after experimental cerebral ischemia-reperfusion, using translational MRI, behavioral testing and multi-model inference analyses. Male and female rats (N = 60) were subjected to 45-/90-min filament-induced transient middle cerebral artery occlusion. Diffusion, T2- and perfusion-weighted MRI at occlusion, 0.5 h and four days after recanalization, enabled tracking of tissue fate, and relative regional cerebral blood flow (rrCBF) and -volume (rrCBV). Lesion areas were parcellated into core, salvageable tissue and delayed injury, verified by histology. Recanalization resulted in acute-to-subacute lesion volume reductions, most apparently in females (n = 19). Hyperacute normo-to-hyperperfusion in the post-ischemic lesion augmented towards day four, particularly in males (n = 23). Tissue suffering delayed injury contained higher ratios of hypoperfused voxels early after recanalization. Regressed against acute-to-subacute lesion volume change, increased rrCBF associated with lesion growth, but increased rrCBV with lesion reduction. Similar relationships were detected for behavioral outcome. Post-ischemic hyperperfusion may develop differentially in males and females, and can be beneficial or detrimental to disease outcome, depending on which perfusion parameter is used as explanatory variable.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Masculino , Femenino , Ratas , Animales , Isquemia Encefálica/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Angiografía por Resonancia Magnética , Accidente Cerebrovascular/diagnóstico por imagen , Resultado del TratamientoRESUMEN
Thrombus computed tomography (CT) imaging characteristics may correspond with thrombus mechanical properties and thus predict thrombectomy success. The impact of red blood cell (RBC) content on these properties (imaging and mechanics) has been widely studied. However, the additional effect of platelets has not been considered. The objective of the current study was to examine the individual and combined effects of blood clot RBC and platelet content on resultant CT imaging and mechanical characteristics. Human blood clot analogues were prepared from a combination of preselected RBC volumes and platelet concentrations to decouple their contributions. The resulting clot RBC content (%) and platelet content (%) were determined using Martius Scarlet Blue and CD42b staining, respectively. Non-contrast and contrast-enhanced CT (NCCT and CECT) scans were performed to measure the clot densities. CECT density increase was taken as a proxy for clinical perviousness. Unconfined compressive mechanics were analysed by performing 10 cycles of 80% strain. RBC content is the major determinant of clot NCCT density. However, additional consideration of the platelet content improves the association. CECT density increase is influenced by clot platelet and not RBC content. Platelet content is the dominant component driving clot stiffness, especially at high strains. Both RBC and platelet content contribute to the clot's viscoelastic and plastic compressive properties. The current in vitro results suggest that CT density is reflective of RBC content and subsequent clot viscoelasticity and plasticity, and that perviousness reflects the clot's platelet content and subsequent stiffness. However, these indications should be confirmed in a clinical stroke cohort.
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Plaquetas , Eritrocitos , Trombosis , Tomografía Computarizada por Rayos X , Humanos , Plaquetas/fisiología , Trombosis/diagnóstico por imagenRESUMEN
AIM: Aortic aneurysms (AA) frequently involve dysregulation of transforming growth factor ß (TGF-ß)-signaling in the aorta. Here, FURIN was tested as aneurysm predisposition gene given its role as proprotein convertase in pro-TGF-ß maturation. METHODS AND RESULTS: Rare FURIN variants were detected by whole-exome sequencing of 781 unrelated aortic aneurysm patients and affected relatives. Thirteen rare heterozygous FURIN variants occurred in 3.7% (29) unrelated index AA patients, of which 72% had multiple aneurysms or a dissection.FURIN maturation and activity of these variants were decreased in vitro. Patient-derived fibroblasts showed decreased pro-TGF-ß processing, phosphorylation of downstream effector SMAD2 and kinases ERK1/2, and steady-state mRNA levels of the TGF-ß-responsive ACTA2 gene. In aortic tissue, collagen and fibrillin fibers were affected. One variant (R745Q), observed in 10 unrelated cases, affected TGF-ß signaling variably, indicating effect modification by individual genetic backgrounds. CONCLUSION: FURIN is a novel, frequent genetic predisposition for abdominal-, thoracic-, and multiple aortic or middle sized artery aneurysms in older patients, by affecting intracellular TGF-ß signaling, depending on individual genetic backgrounds.
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The objective of this study was to compare heart-specific fatty acid binding protein (hFABP) and high-sensitivity troponin I (hsTnI) via serial measurements to identify early time points to accurately quantify infarct size and no-reflow in a preclinical swine model of ST-elevated myocardial infarction (STEMI). Myocardial necrosis, usually confirmed by hsTnI or TnT, takes several hours of ischemia before plasma levels rise in the absence of reperfusion. We evaluated the fast marker hFABP compared with hsTnI to estimate infarct size and no-reflow upon reperfused (2 h occlusion) and nonreperfused (8 h occlusion) STEMI in swine. In STEMI (n = 4) and STEMI + reperfusion (n = 8) induced in swine, serial blood samples were taken for hFABP and hsTnI and compared with triphenyl tetrazolium chloride and thioflavin-S staining for infarct size and no-reflow at the time of euthanasia. hFABP increased faster than hsTnI upon occlusion (82 ± 29 vs. 180 ± 73 min, P < 0.05) and increased immediately upon reperfusion while hsTnI release was delayed 16 ± 3 min (P < 0.05). Peak hFABP and hsTnI reperfusion values were reached at 30 ± 5 and 139 ± 21 min, respectively (P < 0.05). Infarct size (containing 84 ± 0.6% no-reflow) correlated well with area under the curve for hFABP (r(2) = 0.92) but less for hsTnI (r(2) = 0.53). At 50 and 60 min reperfusion, hFABP correlated best with infarct size (r(2) = 0.94 and 0.93) and no-reflow (r(2) = 0.96 and 0.94) and showed high sensitivity for myocardial necrosis (2.3 ± 0.6 and 0.4 ± 0.6 g). hFABP rises faster and correlates better with infarct size and no-reflow than hsTnI in STEMI + reperfusion when measured early after reperfusion. The highest sensitivity detecting myocardial necrosis, 0.4 ± 0.6 g at 60 min postreperfusion, provides an accurate and early measurement of infarct size and no-reflow.
Asunto(s)
Circulación Coronaria , Proteínas de Unión a Ácidos Grasos/sangre , Infarto del Miocardio/terapia , Reperfusión Miocárdica/efectos adversos , Miocardio/metabolismo , Fenómeno de no Reflujo/etiología , Troponina I/sangre , Animales , Benzotiazoles , Biomarcadores/sangre , Modelos Animales de Enfermedad , Femenino , Hemodinámica , Masculino , Infarto del Miocardio/sangre , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocardio/patología , Necrosis , Fenómeno de no Reflujo/sangre , Fenómeno de no Reflujo/patología , Fenómeno de no Reflujo/fisiopatología , Valor Predictivo de las Pruebas , Factores de Riesgo , Coloración y Etiquetado/métodos , Porcinos , Sales de Tetrazolio , Tiazoles , Factores de Tiempo , Regulación hacia ArribaRESUMEN
A neonate with pulmonary hypertension was supported with extracorporeal membrane oxygenation (ECMO). During ECMO support, the patient developed Enterococcus faecalis bacteremia, treated with targeted antibiotics. Despite the maximum dose of antibiotics, routine blood cultures remained positive throughout the ECMO treatment. A circuit change was performed due to buildup of thrombotic material and disseminated intravascular coagulation (DIC) inside the circuit. Thrombus formation was more extensive in the first than the second circuit. Gram-positive diplococci were present in all initial circuit clots and gram-positive masses surrounded by fibrin were found inside thrombi of the second circuit. Scanning electron microscopy (SEM) revealed a dense fibrin network with embedded red blood cells and bacteria in the first circuit. In the second circuit, SEM analysis revealed scattered micro thrombi. Polymerase chain reaction for identification of bacteria in the thrombus of the first circuit showed the same bacteria as found in blood cultures and did not achieve a sufficient signal in the second circuit. This case report shows that bacteria can nestle in thrombi of an ECMO circuit and that there is a rationale for a circuit change in a patient with persistent positive blood cultures and DIC.
Asunto(s)
Bacteriemia , Oxigenación por Membrana Extracorpórea , Trombosis , Recién Nacido , Humanos , Oxigenación por Membrana Extracorpórea/efectos adversos , Trombosis/etiología , Fibrina , Bacterias , Bacteriemia/complicaciones , Antibacterianos/uso terapéuticoRESUMEN
Endovascular thrombectomy procedures are significantly influenced by the mechanical response of thrombi to the multi-axial loading imposed during retrieval. Compression tests are commonly used to determine compressive ex vivo thrombus and clot analogue stiffness. However, there is a shortage of data in tension. This study compares the tensile and compressive response of clot analogues made from the blood of healthy human donors in a range of compositions. Citrated whole blood was collected from six healthy human donors. Contracted and non-contracted fibrin clots, whole blood clots and clots reconstructed with a range of red blood cell (RBC) volumetric concentrations (5-80%) were prepared under static conditions. Both uniaxial tension and unconfined compression tests were performed using custom-built setups. Approximately linear nominal stress-strain profiles were found under tension, while strong strain-stiffening profiles were observed under compression. Low- and high-strain stiffness values were acquired by applying a linear fit to the initial and final 10% of the nominal stress-strain curves. Tensile stiffness values were approximately 15 times higher than low-strain compressive stiffness and 40 times lower than high-strain compressive stiffness values. Tensile stiffness decreased with an increasing RBC volume in the blood mixture. In contrast, high-strain compressive stiffness values increased from 0 to 10%, followed by a decrease from 20 to 80% RBC volumes. Furthermore, inter-donor differences were observed with up to 50% variation in the stiffness of whole blood clot analogues prepared in the same manner between healthy human donors.