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1.
Eur Heart J Open ; 4(3): oeae032, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38784103

RESUMO

Over several decades, the approach to treating dyslipidaemias during pregnancy remains essentially unchanged. The lack of advancement in this field is mostly related to the fact that we lack clinical trials of pregnant patients both with available as well as new therapies. While there are numerous novel therapies developed for non-pregnant patients, there are still many limitations in dyslipidaemia treatment during pregnancy. Besides pharmacotherapy and careful clinical assessment, the initiation of behavioural modifications as well as pre-conception management is very important. Among the various lipid-lowering medications, bile acid sequestrants are the only ones officially approved for treating dyslipidaemia in pregnancy. Ezetimibe and fenofibrate can be considered if their benefits outweigh potential risks. Statins are still considered contraindicated, primarily due to animal studies and human case reports. However, recent systematic reviews and meta-analyses as well as data on familial hypercholesterolaemia (FH) in pregnant patients have indicated that their use may not be harmful and could even be beneficial in certain selected cases. This is especially relevant for pregnant patients at very high cardiovascular risk, such as those who have already experienced an acute cardiovascular event or have homozygous or severe forms of heterozygous FH. In these cases, the decision to continue therapy during pregnancy should weigh the potential risks of discontinuation. Bempedoic acid, olezarsen, evinacumab, evolocumab and alirocumab, and inclisiran are options to consider just before and after pregnancy is completed. In conclusion, decisions regarding lipid-lowering therapy for pregnant patients should be personalized. Despite the challenges in designing and conducting studies in pregnant women, there is a strong need to establish the safety and efficacy of dyslipidaemia treatment during pregnancy.

2.
Obes Pillars ; 10: 100108, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38706496

RESUMO

Background: This joint expert review by the Obesity Medicine Association (OMA) and National Lipid Association (NLA) provides clinicians an overview of the pathophysiologic and clinical considerations regarding obesity, dyslipidemia, and cardiovascular disease (CVD) risk. Methods: This joint expert review is based upon scientific evidence, clinical perspectives of the authors, and peer review by the OMA and NLA leadership. Results: Among individuals with obesity, adipose tissue may store over 50% of the total body free cholesterol. Triglycerides may represent up to 99% of lipid species in adipose tissue. The potential for adipose tissue expansion accounts for the greatest weight variance among most individuals, with percent body fat ranging from less than 5% to over 60%. While population studies suggest a modest increase in blood low-density lipoprotein cholesterol (LDL-C) levels with excess adiposity, the adiposopathic dyslipidemia pattern most often described with an increase in adiposity includes elevated triglycerides, reduced high density lipoprotein cholesterol (HDL-C), increased non-HDL-C, elevated apolipoprotein B, increased LDL particle concentration, and increased small, dense LDL particles. Conclusions: Obesity increases CVD risk, at least partially due to promotion of an adiposopathic, atherogenic lipid profile. Obesity also worsens other cardiometabolic risk factors. Among patients with obesity, interventions that reduce body weight and improve CVD outcomes are generally associated with improved lipid levels. Given the modest improvement in blood LDL-C with weight reduction in patients with overweight or obesity, early interventions to treat both excess adiposity and elevated atherogenic cholesterol (LDL-C and/or non-HDL-C) levels represent priorities in reducing the risk of CVD.

3.
Brain Spine ; 4: 102830, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38764890

RESUMO

Introduction: Post-traumatic hypopituitarism (PTHP) is a significant, but often neglected consequence of traumatic brain injury (TBI). Research question: We aimed to provide a comprehensive overview of epidemiology, pathophysiology, clinical features and diagnostic approaches of PTHP. Materials and methods: MEDLINE, EMBASE, Cochrane Library and Web of Science were searched. 45 articles of human studies evaluating acute endocrine changes following mild, moderate and severe TBI were selected. Results: Severity of TBI seems to be the most important risk factor of PTHP. Adrenal insufficiency (AI) was present in 10% of TBI patients (prevalence can be as high as 50% after severe TBI), and hypocortisolemia is a predictor of mortality and long-term hypopituitarism. Suppression of the thyroid axis in 2-33% of TBI patients may be an independent predictor of adverse neurological outcome, as well. 9-36% of patients with severe TBI exhibit decreased function of the somatotrophic axis with a divergent effect on the central nervous system. Arginine-Vasopressin (AVP) deficiency is present in 15-51% of patients, associated with increased mortality and unfavorable outcome. Due to shear and injury of the stalk hyperprolactinemia is relatively common (2-50%), but it bears little clinical significance. Sex hormone levels remain within normal values. Discussion and conclusion: PTHP occurs frequently after TBI, affecting various axis and determining patients' outcome. However, evidence is scarce regarding exact epidemiology, diagnosis, and effective clinical application of hormone substitution. Future studies are needed to identify patients at-risk, determine the optimal timing for endocrine testing, and refine diagnostic and treatment approaches to improve outcome.

4.
J Am Coll Cardiol ; 83(20): 1939-1952, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38593947

RESUMO

BACKGROUND: Most patients with atherosclerotic cardiovascular disease fail to achieve guideline-directed low-density lipoprotein cholesterol (LDL-C) goals. Twice-yearly inclisiran lowers LDL-C by ∼50% when added to statins. OBJECTIVES: This study evaluated the effectiveness of an "inclisiran first" implementation strategy (adding inclisiran immediately upon failure to reach LDL-C <70 mg/dL despite receiving maximally tolerated statins) vs representative usual care in U.S. patients with atherosclerotic cardiovascular disease. METHODS: VICTORION-INITIATE, a prospective, pragmatically designed trial, randomized patients 1:1 to inclisiran (284 mg at days 0, 90, and 270) plus usual care (lipid management at treating physician's discretion) vs usual care alone. Primary endpoints were percentage change in LDL-C from baseline and statin discontinuation rates. RESULTS: We randomized 450 patients (30.9% women, 12.4% Black, 15.3% Hispanic); mean baseline LDL-C was 97.4 mg/dL. The "inclisiran first" strategy led to significantly greater reductions in LDL-C from baseline to day 330 vs usual care (60.0% vs 7.0%; P < 0.001). Statin discontinuation rates with "inclisiran first" (6.0%) were noninferior vs usual care (16.7%). More "inclisiran first" patients achieved LDL-C goals vs usual care (<70 mg/dL: 81.8% vs 22.2%; <55 mg/dL: 71.6% vs 8.9%; P < 0.001). Treatment-emergent adverse event (TEAE) and serious TEAE rates compared similarly between treatment strategies (62.8% vs 53.7% and 11.5% vs 13.4%, respectively). Injection-site TEAEs and TEAEs causing treatment withdrawal occurred more commonly with "inclisiran first" than usual care (10.3% vs 0.0% and 2.6% vs 0.0%, respectively). CONCLUSIONS: An "inclisiran first" implementation strategy led to greater LDL-C lowering compared with usual care without discouraging statin use or raising new safety concerns. (A Randomized, Multicenter, Open-label Trial Comparing the Effectiveness of an "Inclisiran First" Implementation Strategy to Usual Care on LDL Cholesterol [LDL-C] in Patients With Atherosclerotic Cardiovascular Disease and Elevated LDL-C [≥70 mg/dL] Despite Receiving Maximally Tolerated Statin Therapy [VICTORION-INITIATE]; NCT04929249).


Assuntos
Aterosclerose , LDL-Colesterol , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , LDL-Colesterol/sangue , Idoso , Aterosclerose/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Oligonucleotídeos/uso terapêutico , Resultado do Tratamento
5.
Geroscience ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639833

RESUMO

Cerebral microhemorrhages (CMHs, also known as cerebral microbleeds) are a critical but frequently underestimated aspect of cerebral small vessel disease (CSVD), bearing substantial clinical consequences. Detectable through sensitive neuroimaging techniques, CMHs reveal an extensive pathological landscape. They are prevalent in the aging population, with multiple CMHs often being observed in a given individual. CMHs are closely associated with accelerated cognitive decline and are increasingly recognized as key contributors to the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). This review paper delves into the hypothesis that atherosclerosis, a prevalent age-related large vessel disease, extends its pathological influence into the cerebral microcirculation, thereby contributing to the development and progression of CSVD, with a specific focus on CMHs. We explore the concept of vascular aging as a continuum, bridging macrovascular pathologies like atherosclerosis with microvascular abnormalities characteristic of CSVD. We posit that the same risk factors precipitating accelerated aging in large vessels (i.e., atherogenesis), primarily through oxidative stress and inflammatory pathways, similarly instigate accelerated microvascular aging. Accelerated microvascular aging leads to increased microvascular fragility, which in turn predisposes to the formation of CMHs. The presence of hypertension and amyloid pathology further intensifies this process. We comprehensively overview the current body of evidence supporting this interconnected vascular hypothesis. Our review includes an examination of epidemiological data, which provides insights into the prevalence and impact of CMHs in the context of atherosclerosis and CSVD. Furthermore, we explore the shared mechanisms between large vessel aging, atherogenesis, microvascular aging, and CSVD, particularly focusing on how these intertwined processes contribute to the genesis of CMHs. By highlighting the role of vascular aging in the pathophysiology of CMHs, this review seeks to enhance the understanding of CSVD and its links to systemic vascular disorders. Our aim is to provide insights that could inform future therapeutic approaches and research directions in the realm of neurovascular health.

6.
Am J Prev Cardiol ; 18: 100648, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38584606

RESUMO

Triglycerides play a crucial role in the efficient storage of energy in the body. Mild and moderate hypertriglyceridemia (HTG) is a heterogeneous disorder with significant association with atherosclerotic cardiovascular disease (ASCVD), including myocardial infarction, ischemic stroke, and peripheral artery disease and represents an important component of the residual ASCVD risk in statin treated patients despite optimal low-density lipoprotein cholesterol reduction. Individuals with severe HTG (>1,000 mg/dL) rarely develop atherosclerosis but have an incremental incidence of acute pancreatitis with significant morbidity and mortality. HTG can occur from a combination of genetic (both mono and polygenic) and environmental factors including poor diet, low physical activity, obesity, medications, and diseases like insulin resistance and other endocrine pathologies. HTG represents a potential target for ASCVD risk and pancreatitis risk reduction, however data on ASCVD reduction by treating HTG is still lacking and HTG-associated acute pancreatitis occurs too rarely to effectively demonstrate treatment benefit. In this review, we address the key aspects of HTG pathophysiology and examine the mechanisms and background of current and emerging therapies in the management of HTG.

7.
bioRxiv ; 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38585943

RESUMO

Tissue barriers must be rapidly restored after injury to promote regeneration. However, the mechanism behind this process is unclear, particularly in cases where the underlying extracellular matrix is still compromised. Here, we report the discovery of matrimeres as constitutive nanoscale mediators of tissue integrity and function. We define matrimeres as non-vesicular nanoparticles secreted by cells, distinguished by a primary composition comprising at least one matrix protein and DNA molecules serving as scaffolds. Mesenchymal stromal cells assemble matrimeres from fibronectin and DNA within acidic intracellular compartments. Drawing inspiration from this biological process, we have achieved the successful reconstitution of matrimeres without cells. This was accomplished by using purified matrix proteins, including fibronectin and vitronectin, and DNA molecules under optimal acidic pH conditions, guided by the heparin-binding domain and phosphate backbone, respectively. Plasma fibronectin matrimeres circulate in the blood at homeostasis but exhibit a 10-fold decrease during systemic inflammatory injury in vivo . Exogenous matrimeres rapidly restore vascular integrity by actively reannealing endothelial cells post-injury and remain persistent in the host tissue matrix. The scalable production of matrimeres holds promise as a biologically inspired platform for regenerative nanomedicine.

8.
Eur J Haematol ; 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644361

RESUMO

The prognosis of elderly AML patients had not even been improved by using hypomethylating agents; however, synergistic effect of combining azacitidin with venetoclax had resulted in a remarkable therapeutic advance. Our goal was to study the latter treatment with a new dosing regimen in a retrospective/observational study. In our department, we analyzed the data of AML patients who were unfit for curative high-dose treatment and accepted the medication with a fixed-dose of azacitidin and venetoclax combination (AZA-VEN, 100 mg sc for 7 days-100 mg per os continuously). The primary end point was the overall survival. In total, 55 AML patients received the treatment between OCT/2019-DEC/2022. Mean age was 69.4-year (48-84), median overall survival was 17.2-month (95% CI, 14.3-20.10) Composite CR: (CR + CRi) 62%. Side effect CTCAE 3 or higher: neutropenia with fever: 36.4%, anemia: 29.1%, thrombocytopenia: 16.4% and nausea 20%. AZA-VEN combination treatment of our unfit AML patients was found to be a good therapeutic option. The results achieved with significantly lower doses of the fixed dose of AZA-VEN are comparable to the conclusions of the VIALE-A study, and the less severe side effects we have observed are explained by the milder neutropenia of the newly introduced regimen.

9.
Am J Cardiol ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636622

RESUMO

Atherosclerosis is an inflammatory disease. Coronary artery calcium (CAC) is a marker of atherosclerotic disease events and mortality risk. Increased GlycA, an emerging marker of inflammation, is associated with a higher risk for coronary artery disease (CAD). However, there is conflicting evidence on whether GlycA predicts subclinical CAD progression. We hypothesized that GlycA can predict subclinical CAC incidence/progression in healthy participants. We included 2,690 ELSA-Brasil cohort participants without cardiovascular/chronic inflammatory disease not receiving statin therapy who had GlycA levels measured and 2 interval CAC assessments between 2010 and 2018. Multivariable logistic and linear regression models were computed to evaluate GlycA as a predictor of CAC incidence and progression. CAC incidence required a baseline CAC of 0. CAC progression required a baseline CAC >0. The mean age of participants was 48.6 ± 7.7 years, 56.7% were women, and 54.6% and 16.1% (429 of 2,690) were White and Black, respectively. The mean CAC interscan period was 5.1 ± 0.9 years, the mean GlycA level was 414.7 ± 65 µmol/L, and the incidence of CAC was 13.1% (280 of 2,129). The GlycA level odds ratio for CAC incidence was 1.002 (95% confidence interval 1.0005 to 1.005, p = 0.016), adjusted for demographics, lifestyle, a family history of early CAD (≤60 years), lipids, and co-morbidities. The GlycA (≤p25 vs ≥p75) odds ratio for CAC progression (Berry definition) was 1.77 (95% confidence interval 1.07 to 2.96, p = 0.03) in a similar multivariable-adjusted model. Higher GlycA levels were associated with CAC incidence and progression in a healthy Brazilian cohort.

10.
J Clin Lipidol ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38664184

RESUMO

BACKGROUND: This joint expert review by the Obesity Medicine Association (OMA) and National Lipid Association (NLA) provides clinicians an overview of the pathophysiologic and clinical considerations regarding obesity, dyslipidemia, and cardiovascular disease (CVD) risk. METHODS: This joint expert review is based upon scientific evidence, clinical perspectives of the authors, and peer review by the OMA and NLA leadership. RESULTS: Among individuals with obesity, adipose tissue may store over 50% of the total body free cholesterol. Triglycerides may represent up to 99% of lipid species in adipose tissue. The potential for adipose tissue expansion accounts for the greatest weight variance among most individuals, with percent body fat ranging from less than 5% to over 60%. While population studies suggest a modest increase in blood low-density lipoprotein cholesterol (LDL-C) levels with excess adiposity, the adiposopathic dyslipidemia pattern most often described with an increase in adiposity includes elevated triglycerides, reduced high density lipoprotein cholesterol (HDL-C), increased non-HDL-C, elevated apolipoprotein B, increased LDL particle concentration, and increased small, dense LDL particles. CONCLUSIONS: Obesity increases CVD risk, at least partially due to promotion of an adiposopathic, atherogenic lipid profile. Obesity also worsens other cardiometabolic risk factors. Among patients with obesity, interventions that reduce body weight and improve CVD outcomes are generally associated with improved lipid levels. Given the modest improvement in blood LDL-C with weight reduction in patients with overweight or obesity, early interventions to treat both excess adiposity and elevated atherogenic cholesterol (LDL-C and/or non-HDL-C) levels represent priorities in reducing the risk of CVD.

11.
NPJ Biofilms Microbiomes ; 10(1): 16, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429317

RESUMO

Pseudomonas aeruginosa is an important cause of lower respiratory tract infections, such as ventilator-associated bacterial pneumonia (VABP). Using inhaled antibiotics to treat VABP can achieve high drug concentrations at the infection site while minimizing systemic toxicities. Despite the theoretical advantages, clinical trials have failed to show a benefit for inhaled antibiotic therapy in treating VABP. A potential reason for this discordance is the presence of biofilm-embedded bacteria in lower respiratory tract infections. Drug selection and dosing are often based on data from bacteria grown planktonically. In the present study, an in vitro air-liquid interface pharmacokinetic/pharmacodynamic biofilm model was optimized to evaluate the activity of simulated epithelial lining fluid exposures of inhaled and intravenous doses of polymyxin B and tobramycin against two P. aeruginosa strains. Antibiotic activity was also determined against the P. aeruginosa strains grown planktonically. Our study revealed that inhaled antibiotic exposures were more active than their intravenous counterparts across biofilm and planktonic populations. Inhaled exposures of polymyxin B and tobramycin exhibited comparable activity against planktonic P. aeruginosa. Although inhaled polymyxin B exposures were initially more active against P. aeruginosa biofilms (through 6 h), tobramycin was more active by the end of the experiment (48 h). Together, these data slightly favor the use of inhaled tobramycin for VABP caused by biofilm-forming P. aeruginosa that are not resistant to either antibiotic. The optimized in vitro air-liquid interface pharmacokinetic/pharmacodynamic biofilm model may be beneficial for the development of novel anti-biofilm agents or to optimize antibiotic dosing for infections such as VABP.


Assuntos
Infecções por Pseudomonas , Infecções Respiratórias , Humanos , Antibacterianos , Pseudomonas aeruginosa , Polimixina B/farmacologia , Tobramicina/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Biofilmes
12.
EES Catal ; 2(2): 664-674, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38464594

RESUMO

Photoelectrodes with FTO/Au/Sb2Se3/TiO2/Au architecture were studied in photoelectrochemical CO2 reduction reaction (PEC CO2RR). The preparation is based on a simple spin coating technique, where nanorod-like structures were obtained for Sb2Se3, as confirmed by SEM images. A thin conformal layer of TiO2 was coated on the Sb2Se3 nanorods via ALD, which acted as both an electron transfer layer and a protective coating. Au nanoparticles were deposited as co-catalysts via photo-assisted electrodeposition at different applied potentials to control their growth and morphology. The use of such architectures has not been explored in CO2RR yet. The photoelectrochemical performance for CO2RR was investigated with different Au catalyst loadings. A photocurrent density of ∼7.5 mA cm-2 at -0.57 V vs. RHE for syngas generation was achieved, with an average Faradaic efficiency of 25 ± 6% for CO and 63 ± 12% for H2. The presented results point toward the use of Sb2Se3-based photoelectrodes in solar CO2 conversion applications.

13.
Animals (Basel) ; 14(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38396621

RESUMO

In conserving the genetic diversity of domestic animal breeds, strategies that emphasise between-breed diversity may not be optimal, as they neglect within-breed variation. The aim of the present study was to assess the extent of population subdivision in three Mangalica pig breeds and the contribution of migration to their substructure. Wright's FST coefficient was calculated based on genealogical data with breeding animals born between 1981 and 2023, with three colour variants (Blonde, Swallow-Belly and Red). These Wright's FST coefficients were analysed using multidimensional scaling to reveal the population substructure. The average FST coefficient was 0.04 for the Blonde breed and 0.047 for the Swallow-Belly and Red Mangalica breeds, while these parameters were lower in the active herds at 0.03 and 0.04, respectively. The migration of individuals between herds was 61.63% for the Blonde breed and 75.53% and 63.64% for the Swallow-Belly and Red Magalica breeds, respectively. No population substructure was observed in any of the Mangalica breeds, which can be explained by the extensive migration between herds.

15.
Diabetes Ther ; 15(1): 33-60, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37751143

RESUMO

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic became superimposed on the pre-existing obesity and diabetes mellitus (DM) pandemics. Since COVID-19 infection alters the metabolic equilibrium, it may induce pathophysiologic mechanisms that potentiate new-onset DM, and we evaluated this issue. METHOD: A systematic review of the literature published from the 1 January 2020 until the 20 July 2023 was performed (PROSPERO registration number CRD42022341638). We included only full-text articles of both human clinical and randomized controlled trials published in English and enrolling adults (age > 18 years old) with ongoing or preceding COVID-19 in whom hyperglycemia was detected. The search was based on the following criteria: "(new-onset diabetes mellitus OR new-onset DM) AND (COVID-19) AND adults". RESULTS: Articles on MEDLINE (n = 70) and the Web of Science database (n = 16) were included and analyzed by two researchers who selected 20 relevant articles. We found evidence of a bidirectional relationship between COVID-19 and DM. CONCLUSIONS: This link operates as a pathophysiological mechanism supported by epidemiological data and also by the clinical and biological findings obtained from the affected individuals. The COVID-19 pandemic raised the incidence of DM through different pathophysiological and psychosocial factors.

17.
Geroscience ; 46(1): 21-37, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38044400

RESUMO

Emerging evidence from both clinical and preclinical studies underscores the role of aging in potentiating the detrimental effects of hypertension on cerebral microhemorrhages (CMHs, or cerebral microbleeds). CMHs progressively impair neuronal function and contribute to the development of vascular cognitive impairment and dementia. There is growing evidence showing accumulation of senescent cells within the cerebral microvasculature during aging, which detrimentally affects cerebromicrovascular function and overall brain health. We postulated that this build-up of senescent cells renders the aged cerebral microvasculature more vulnerable, and consequently, more susceptible to CMHs. To investigate the role of cellular senescence in CMHs' pathogenesis, we subjected aged mice, both with and without pre-treatment with the senolytic agent ABT263/Navitoclax, and young control mice to hypertension via angiotensin-II and L-NAME administration. The aged cohort exhibited a markedly earlier onset, heightened incidence, and exacerbated neurological consequences of CMHs compared to their younger counterparts. This was evidenced through neurological examinations, gait analysis, and histological assessments of CMHs in brain sections. Notably, the senolytic pre-treatment wielded considerable cerebromicrovascular protection, effectively delaying the onset, mitigating the incidence, and diminishing the severity of CMHs. These findings hint at the potential of senolytic interventions as a viable therapeutic avenue to preempt or alleviate the consequences of CMHs linked to aging, by counteracting the deleterious effects of senescence on brain microvasculature.


Assuntos
Compostos de Anilina , Hipertensão , Senoterapia , Sulfonamidas , Humanos , Camundongos , Animais , Idoso , Envelhecimento/patologia , Senescência Celular
18.
Adv Sci (Weinh) ; 11(10): e2303516, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38155460

RESUMO

Impaired cerebrovascular function contributes to the genesis of age-related cognitive decline. In this study, the hypothesis is tested that impairments in neurovascular coupling (NVC) responses and brain network function predict cognitive dysfunction in older adults. Cerebromicrovascular and working memory function of healthy young (n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed. To determine NVC responses and functional connectivity (FC) during a working memory (n-back) paradigm, oxy- and deoxyhemoglobin concentration changes from the frontal cortex using functional near-infrared spectroscopy are recorded. NVC responses are significantly impaired during the 2-back task in aged participants, while the frontal networks are characterized by higher local and global connection strength, and dynamic FC (p < 0.05). Both impaired NVC and increased FC correlate with age-related decline in accuracy during the 2-back task. These findings suggest that task-related brain states in older adults require stronger functional connections to compensate for the attenuated NVC responses associated with working memory load.


Assuntos
Disfunção Cognitiva , Acoplamento Neurovascular , Humanos , Idoso , Acoplamento Neurovascular/fisiologia , Encéfalo/fisiologia , Lobo Frontal
20.
Front Neurol ; 14: 1252796, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38073626

RESUMO

Introduction: Mild traumatic brain injury (mTBI) and hypertension synergize to induce persistent disruption of the blood-brain barrier (BBB), neuroinflammation and cognitive decline. However, the underlying mechanisms are not known. Cerebral production of Cyclophilin A (CyPA) is induced in hypertension and after TBI, and it was demonstrated to activate the nuclear factor-κB (NF-kB)- matrix-metalloproteinase-9 (MMP-9) pathway in cerebral vessels leading to BBB disruption. Methods: To test the role of CyPA in mTBI- and hypertension-induced BBB disruption we induced mTBI in normotensive and spontaneously hypertensive rats (SHR), then the animals were treated with cyclosporine A (a specific inhibitor of CyPA production) or vehicle for 7 days. We assessed BBB permeability and integrity, cerebral expression and activity of the CyPA-NF-kB-MMP-9 pathway, extravasation of fibrin and neuroinflammation. Results: We found that mild TBI induced BBB disruption and upregulation of the CyPA-NF-kB-MMP-9 pathway in hypertension, which were prevented by blocking CyPA. Cyclosporine treatment and preservation of BBB function prevented accumulation of blood-derived fibrin in the brain parenchyma of hypertensive rats after mTBI and reversed increased neuroinflammation. Discussion: We propose that mTBI and hypertension interact to promote BBB disruption via the CyPA-NF-kB-MMP-9 pathway, and inhibition of cyclophilin production after mTBI may exert neuroprotection and improve cognitive function in hypertensive patients.

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