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1.
J Magn Reson Imaging ; 51(1): 98-107, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31218803

RESUMO

BACKGROUND: Clinical assessments of peripheral artery disease (PAD) severity are insensitive to pathophysiological changes in muscle tissue oxygenation and energy metabolism distal to the affected artery. PURPOSE: To quantify the blood oxygenation level-dependent (BOLD) response and phosphocreatine (PCr) recovery kinetics on a clinical MR system during a single exercise-recovery session in PAD patients. STUDY TYPE: Case-control study. SUBJECTS: Fifteen Fontaine stage II patients, and 18 healthy control subjects FIELD STRENGTH/SEQUENCE: Interleaved dynamic multiecho gradient-echo 1 H T2 * mapping and adiabatic pulse-acquire 31 P-MR spectroscopy at 3T. ASSESSMENT: Blood pressure in the arms and ankles were measured to determine the ankle-brachial index (ABI). Subjects performed a plantar flexion exercise-recovery protocol. The gastrocnemius and soleus muscle BOLD responses were characterized using the T2 * maps. High-energy phosphate metabolite concentrations were quantified by fitting the series of 31 P-MR spectra. The PCr recovery time constant (τPCr ) was derived as a measure of in vivo mitochondrial oxidative capacity. STATISTICAL TESTS: Comparisons between groups were performed using two-sided Mann-Whitney U-tests. Relations between variables were assessed by Pearson's r correlation coefficients. RESULTS: The amplitude of the functional hyperemic BOLD response in the gastrocnemius muscle was higher in PAD patients compared with healthy subjects (-3.8 ± 1.4% vs. -1.4 ± 0.3%; P < 0.001), and correlated with the ABI (r = 0.79; P < 0.001). PCr recovery was slower in PAD patients (τPCr = 52.0 ± 13.5 vs. 30.3 ± 9.7 sec; P < 0.0001), and correlated with the ABI (r = -0.64; P < 0.001). Moreover, τPCr correlated with the hyperemic BOLD response in the gastrocnemius muscle (r = -0.66; P < 0.01). DATA CONCLUSION: MR readouts of calf muscle tissue oxygenation and high-energy phosphate metabolism were acquired essentially simultaneously during a single exercise-recovery session. A pronounced hypoxia-triggered vasodilation in PAD is associated with a reduced mitochondrial oxidative capacity. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:98-107.

2.
Cardiol Clin ; 38(1): 1-12, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31753168

RESUMO

Calcific aortic valve stenosis is the commonest form of heart valve disease in high-income countries and set to become a major health care burden. Currently, there are no medical therapies that have proved to slow down or halt disease progression. The only available treatment is aortic valve replacement, of which the optimal timing is unknown and to which not all patients are suited. This review discusses the pathophysiology of aortic stenosis, how noninvasive imaging techniques have improved our understanding of the underlying biology, and how these emerging insights might translate into potential novel treatments targeting oxidized lipids, fibrosis, and calcification.

3.
Mar Drugs ; 17(12)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842319

RESUMO

The adhesion molecule P-selectin is present on the cell surface of both activated endothelium and activated platelets. The present study describes the pharmaceutical development, safety evaluation, and preclinical efficacy of a micro-dosed radiotracer. The macromolecular nanoscale assembly consisted of a natural compound made of a sulfated fucose-rich polysaccharides (fucoidan) and a radionuclide (technetium-99m) for the detection of P-selectin expression in cardiovascular diseases. After extraction and fractionation from brown seaweeds, the good manufacturing practice (GMP) production of a low molecular weight (LMW) fucoidan of 7 kDa was achieved and full physicochemical characterization was performed. The regulatory toxicology study in rats of the GMP batch of LMW fucoidan revealed no adverse effects up to 400 µg/kg (×500 higher than the expected human dose) and pseudoallergy was not seen as well. In a myocardial ischemia-reperfusion model in rats, the GMP-grade LMW fucoidan labeled with technetium-99m detected P-selectin upregulation in vivo. The present study supports the potential of using 99mTc-fucoidan as an imaging agent to detect activated endothelium in humans.

4.
J Am Heart Assoc ; 8(16): e013020, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31407609

RESUMO

Background Apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio and lipoprotein(a) (Lp[a]) are associated with aortic valve stenosis (AVS) disease progression. Clinical characteristics such as age, sex, and presence of concomitant coronary artery disease may strongly modify these associations; however, these effects have not been well defined in longitudinal studies. We set out to assess these associations between apoB/apoA-I ratio, Lp(a), and AVS incidence in a large population study. Methods and Results We analyzed data from 17 745 participants (mean age, 59.2±9.1 years; men, 44.9%) in the EPIC-Norfolk (European Prospective Investigation Into Cancer in Norfolk Prospective Population Study) population study in whom apoB/apoA-I and Lp(a) levels were measured. Participants were identified as having incident AVS if they were hospitalized or died with AVS as an underlying cause. After a median follow-up of 19.8 years (17.9-21.0 years) there were 403 (2.2%) incident cases of AVS. The hazard ratio for AVS risk was 1.30 (95% CI, 1.19-1.41; P<0.001) per SD increase in apoB/apoA-I. Adjusting for age, sex, and coronary artery disease, there was no significant association between apoB/apoA-I and AVS incidence (hazard ratio, 1.06; 95% CI, 0.97-1.17 [P=0.215]). Elevated Lp(a) (>50 mg/dL) remained an independent risk factor for AVS after adjustment for age, sex, low-density lipoprotein cholesterol, and concomitant coronary artery disease (hazard ratio, 1.70; 95% CI, 1.33-2.19 [P<0.001]). Conclusions In this population study, apoB/apoA-I ratio was associated with risk of AVS incidence, especially in younger and female participants and those without concomitant coronary artery disease. Lp(a) was an independent risk factor for AVS incidence. Interventional trials are needed to investigate whether modulating apoB/apoA-I or lowering Lp(a) can prevent or slow down AVS.

6.
J Am Coll Cardiol ; 73(17): 2150-2162, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31047003

RESUMO

BACKGROUND: Lipoprotein(a) [Lp(a)], a major carrier of oxidized phospholipids (OxPL), is associated with an increased incidence of aortic stenosis (AS). However, it remains unclear whether elevated Lp(a) and OxPL drive disease progression and are therefore targets for therapeutic intervention. OBJECTIVES: This study investigated whether Lp(a) and OxPL on apolipoprotein B-100 (OxPL-apoB) levels are associated with disease activity, disease progression, and clinical events in AS patients, along with the mechanisms underlying any associations. METHODS: This study combined 2 prospective cohorts and measured Lp(a) and OxPL-apoB levels in patients with AS (Vmax >2.0 m/s), who underwent baseline 18F-sodium fluoride (18F-NaF) positron emission tomography (PET), repeat computed tomography calcium scoring, and repeat echocardiography. In vitro studies investigated the effects of Lp(a) and OxPL on valvular interstitial cells. RESULTS: Overall, 145 patients were studied (68% men; age 70.3 ± 9.9 years). On baseline positron emission tomography, patients in the top Lp(a) tertile had increased valve calcification activity compared with those in lower tertiles (n = 79; 18F-NaF tissue-to-background ratio of the most diseased segment: 2.16 vs. 1.97; p = 0.043). During follow-up, patients in the top Lp(a) tertile had increased progression of valvular computed tomography calcium score (n = 51; 309 AU/year [interquartile range: 142 to 483 AU/year] vs. 93 AU/year [interquartile range: 56 to 296 AU/year; p = 0.015), faster hemodynamic progression on echocardiography (n = 129; 0.23 ± 0.20 m/s/year vs. 0.14 ± 0.20 m/s/year] p = 0.019), and increased risk for aortic valve replacement and death (n = 145; hazard ratio: 1.87; 95% CI: 1.13 to 3.08; p = 0.014), compared with lower tertiles. Similar results were noted with OxPL-apoB. In vitro, Lp(a) induced osteogenic differentiation of valvular interstitial cells, mediated by OxPL and inhibited with the E06 monoclonal antibody against OxPL. CONCLUSIONS: In patients with AS, Lp(a) and OxPL drive valve calcification and disease progression. These findings suggest lowering Lp(a) or inactivating OxPL may slow AS progression and provide a rationale for clinical trials to test this hypothesis.

7.
Circ Cardiovasc Imaging ; 12(2): e008513, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30712363

RESUMO

BACKGROUND: Mitral annular calcification (MAC) is associated with cardiovascular events and mitral valve dysfunction. However, the underlying pathophysiology remains incompletely understood. In this prospective longitudinal study, we used a multimodality approach including positron emission tomography, computed tomography, and echocardiography to investigate the pathophysiology of MAC and assess factors associated with disease activity and progression. METHODS: A total of 104 patients (age 72±8 years, 30% women) with calcific aortic valve disease, therefore predisposed to MAC, underwent 18F-sodium fluoride (calcification activity) and 18F-Fluorodeoxyglucose (inflammation activity) positron emission tomography, computed tomography calcium scoring, and echocardiography. Sixty patients underwent repeat computed tomography and echocardiography after 2 years. RESULTS: MAC (mitral annular calcium score >0) was present in 35 (33.7%) patients who had increased 18F-fluoride (tissue-to-background ratio, 2.32 [95% CI, 1.81-3.27] versus 1.30 [1.22-1.49]; P<0.001) and 18F-Fluorodeoxyglucose activity (tissue-to-background ratio, 1.44 [1.37-1.58] versus 1.17 [1.12-1.24]; P<0.001) compared with patients without MAC. MAC activity (18F-fluoride uptake) was closely associated with the local calcium score and 18F-Fluorodeoxyglucose uptake, as well as female sex and renal function. Similarly, MAC progression was closely associated with local factors, in particular, baseline MAC. Traditional cardiovascular risk factors and calcification activity in bone or remote atherosclerotic areas were not associated with disease activity nor progression. CONCLUSIONS: MAC is characterized by increased local calcification activity and inflammation. Baseline MAC burden was associated with disease activity and the rate of subsequent progression. This suggests a self-perpetuating cycle of calcification and inflammation that may be the target of future therapeutic interventions.


Assuntos
Calcinose/diagnóstico por imagem , Doenças das Valvas Cardíacas/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Imagem Multimodal/métodos , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/patologia , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/fisiopatologia , Calcinose/epidemiologia , Calcinose/fisiopatologia , Angiografia por Tomografia Computadorizada , Angiografia Coronária/métodos , Progressão da Doença , Ecocardiografia , Feminino , Doenças das Valvas Cardíacas/epidemiologia , Doenças das Valvas Cardíacas/fisiopatologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Valor Preditivo dos Testes , Prevalência , Prognóstico , Fatores de Tempo
8.
Immunity ; 49(1): 93-106.e7, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29958804

RESUMO

There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the ß2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.


Assuntos
Diabetes Mellitus/fisiopatologia , Células Progenitoras de Granulócitos e Macrófagos/citologia , Células Progenitoras de Granulócitos e Macrófagos/metabolismo , Mielopoese , Neuroimunomodulação , Sistema Nervoso Simpático/metabolismo , Antagonistas de Receptores Adrenérgicos beta 2/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus/sangue , Modelos Animais de Doenças , Feminino , Humanos , Leucócitos/enzimologia , Leucócitos/metabolismo , Masculino , Camundongos , Células Mieloides/citologia , Mielopoese/efeitos dos fármacos , Neuroimunomodulação/efeitos dos fármacos , Norepinefrina/sangue , Transdução de Sinais/efeitos dos fármacos , Baço/citologia , Baço/inervação , Baço/metabolismo , Sistema Nervoso Simpático/efeitos dos fármacos
9.
Eur J Nucl Med Mol Imaging ; 45(11): 1956-1963, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29728748

RESUMO

PURPOSE: An acute coronary syndrome (ACS) is characterized by a multi-level inflammatory response, comprising activation of bone marrow and spleen accompanied by augmented release of leukocytes into the circulation. The duration of this response after an ACS remains unclear. Here, we assessed the effect of an ACS on the multi-level inflammatory response in patients both acutely and after 3 months. METHODS: We performed 18F-DPA-714 PET/CT acutely and 3 months post-ACS in eight patients and eight matched healthy controls. DPA-714, a PET tracer binding the TSPO receptor and highly expressed in myeloid cells, was used to assess hematopoietic activity. We also characterized circulating monocytes and hematopoietic stem and progenitor cells (HSPCs) by flow cytometry in 20 patients acutely and 3 months post-ACS and in 19 healthy controls. RESULTS: In the acute phase, patients displayed a 1.4-fold and 1.3-fold higher 18F-DPA-714 uptake in, respectively, bone marrow (p = 0.012) and spleen (p = 0.039) compared with healthy controls. This coincided with a 2.4-fold higher number of circulating HSPCs (p = 0.001). Three months post-ACS, 18F-DPA-714 uptake in bone marrow decreased significantly (p = 0.002), but no decrease was observed for 18F-DPA-714 uptake in the spleen (p = 0.67) nor for the number of circulating HSPCs (p = 0.75). CONCLUSIONS: 18F-DPA-714 PET/CT reveals an ACS- triggered hematopoietic organ activation as initiator of a prolonged cellular inflammatory response beyond 3 months, characterized by a higher number of circulating leukocytes and their precursors. This multi-level inflammatory response may provide an attractive target for novel treatment options aimed at reducing the high recurrence rate post-ACS.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico por imagem , Células-Tronco Hematopoéticas/citologia , Monócitos/citologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Pirazóis , Pirimidinas , Síndrome Coronariana Aguda/metabolismo , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Receptores CCR2/metabolismo , Baço/imunologia
10.
PLoS One ; 11(11): e0164690, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27820817

RESUMO

Studies on the role of B lymphocytes in atherosclerosis development, have yielded contradictory results. Whereas B lymphocyte-deficiency aggravates atherosclerosis in mice; depletion of mature B lymphocytes reduces atherosclerosis. These observations led to the notion that distinct B lymphocyte subsets have different roles. B1a lymphocytes exert an atheroprotective effect, which has been attributed to secretion of IgM, which can be deposited in atherosclerotic lesions thereby reducing necrotic core formation. Tumor necrosis factor (TNF)-family member 'A Proliferation-Inducing Ligand' (APRIL, also known as TNFSF13) was previously shown to increase serum IgM levels in a murine model. In this study, we investigated the effect of APRIL overexpression on advanced lesion formation and composition, IgM production and B cell phenotype. We crossed APRIL transgenic (APRIL-Tg) mice with ApoE knockout (ApoE-/-) mice. After a 12-week Western Type Diet, ApoE-/-APRIL-Tg mice and ApoE-/- littermates showed similar increases in body weight and lipid levels. Histologic evaluation showed no differences in lesion size, stage or necrotic area. However, smooth muscle cell (α-actin stain) content was increased in ApoE-/-APRIL-Tg mice, implying more stable lesions. In addition, increases in both plaque IgM deposition and plasma IgM levels were found in ApoE-/-APRIL-Tg mice compared with ApoE-/- mice. Flow cytometry revealed a concomitant increase in peritoneal B1a lymphocytes in ApoE-/-APRIL-Tg mice. This study shows that ApoE-/-APRIL-Tg mice have increased oxLDL-specific serum IgM levels, potentially mediated via an increase in B1a lymphocytes. Although no differences in lesion size were found, transgenic ApoE-/-APRIL-Tg mice do show potential plaque stabilizing features in advanced atherosclerotic lesions.


Assuntos
Placa Aterosclerótica/imunologia , Placa Aterosclerótica/metabolismo , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo , Animais , Contagem de Células , Expressão Ectópica do Gene , Humanos , Imunoglobulina M/sangue , Camundongos , Miócitos de Músculo Liso/patologia , Peritônio/imunologia , Placa Aterosclerótica/sangue , Placa Aterosclerótica/patologia , Linfócitos T/citologia , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética
11.
Curr Opin Lipidol ; 27(6): 592-596, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27653220

RESUMO

PURPOSE OF REVIEW: Because human genetic studies and large clinical trials have demonstrated that HDL-cholesterol levels are not causally related to cardiovascular disease risk, attention has shifted toward the functional properties of HDL. Infusion of HDL mimetics containing apolipoprotein A-I remains a potential strategy to exploit the atheroprotective effects of HDL. RECENT FINDINGS: Three HDL mimetic drugs are under development and currently being evaluated in clinical trials. Upon infusion, these drugs increase cholesterol efflux capacity. Although proof-of-concept studies are promising, large outcome studies are awaited. Alternatively, HDL particles may be used for targeted drug delivery in a nanomedicine approach. Finally, links between cholesterol efflux and myelopoeisis may prove to be a target for HDL infusion in the future. SUMMARY: Clinical studies are currently ongoing to evaluate the potential of several HDL mimetic drugs. Novel nanomedicinal approaches and emerging pathophysiological insights may further expand the relevance of HDL infusion.


Assuntos
Aterosclerose/tratamento farmacológico , Materiais Biomiméticos/farmacologia , Lipoproteínas HDL/metabolismo , Animais , Aterosclerose/metabolismo , Aterosclerose/terapia , Materiais Biomiméticos/uso terapêutico , Humanos
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