335 research outputs found

    Hyperintense vessel sign on fluid-attenuated inversion recovery MR imaging is reduced by gadolinium

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    The HVS on FLAIR imaging is a useful marker of acute ischemic stroke. We investigated whether prior administration of gadolinium-based contrast hindered detection of this sign on images from subjects with acute nonlacunar ischemic stroke <4.5 hours after onset. Both blinded and comparative unblinded analyses showed significantly reduced HVS detection on postcontrast images. We suggest that assessment for this sign should be performed on images acquired prior to contrast administration

    Diabetic Cardiovascular Disease Induced by Oxidative Stress.

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    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with diabetes mellitus (DM). DM can lead to multiple cardiovascular complications, including coronary artery disease (CAD), cardiac hypertrophy, and heart failure (HF). HF represents one of the most common causes of death in patients with DM and results from DM-induced CAD and diabetic cardiomyopathy. Oxidative stress is closely associated with the pathogenesis of DM and results from overproduction of reactive oxygen species (ROS). ROS overproduction is associated with hyperglycemia and metabolic disorders, such as impaired antioxidant function in conjunction with impaired antioxidant activity. Long-term exposure to oxidative stress in DM induces chronic inflammation and fibrosis in a range of tissues, leading to formation and progression of disease states in these tissues. Indeed, markers for oxidative stress are overexpressed in patients with DM, suggesting that increased ROS may be primarily responsible for the development of diabetic complications. Therefore, an understanding of the pathophysiological mechanisms mediated by oxidative stress is crucial to the prevention and treatment of diabetes-induced CVD. The current review focuses on the relationship between diabetes-induced CVD and oxidative stress, while highlighting the latest insights into this relationship from findings on diabetic heart and vascular disease

    Unresolved Issues in RNA Therapeutics in Vascular Diseases With a Focus on Aneurysm Disease

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    New technologies have greatly shaped the scientific and medical landscape within the last years. The unprecedented expansion of data and information on RNA biology has led to the discovery of new RNA classes with unique functions and unexpected modifications. Today, the biggest challenge is to transfer the large number of findings in basic RNA biology into corresponding clinical RNA-based therapeutics. Lately, this research begins to yield positive outcomes. RNA drugs advance to the final phases of clinical trials or even receive FDA approval. Furthermore, the introduction of the RNA-guided gene-editing technology CRISPR and advances in the delivery ofmessenger RNAs have triggered a major progression in the field of RNA-therapeutics. Especially short interfering RNAs and antisense oligonucleotides are promising examples for novel categories of therapeutics. However, several issues need to be addressed including intracellular delivery, toxicity, and immune responses before utilizing RNAs in a clinical setting. In this review, we provide an overview on opportunities and challenges for clinical translation of RNA-based therapeutics, with an emphasis on advances in novel delivery technologies and abdominal aortic aneurysm disease where non-coding RNAs have been shown to play a crucial regulatory role

    Changes in EMG and Finger Force with Repeated Hangs from the Hands in Rock Climbers

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    The nature and degree of fatigue in muscles that control finger position during repeated sustained efforts in rock climbing have not been described. The purpose of this study was to identify changes in maximum hang time and forearm electromyogram (EMG) during repeated maximum duration hangs from a simulated rock feature. A second objective was to determine the effect of different recovery times between hangs upon changes in finger force. Five experienced rock climbers performed 2 test sessions on different days in a randomized order. Each session involved 8 repetitions of a maximum duration hang with either 1 min (R1) or 3 min (R3) resting recovery between hangs. Finger force (FF) was measured for the right hand via a piezoelectric force sensor fitted with a plate to accept the distal digits of four fingers. Peak EMG (EMGPK) and EMG Area (EMGAREA) were recorded from the anterior forearm for each hang and standardized as percent of maximum FF EMG prior to statistical analysis. Hang duration progressively decreased over repetitions but tended to plateau around repetition 5 for both R1 and R3 conditions. A significant difference was found for both recovery conditions and repetitions (p\u3c.05) as well as a significant interaction of the two factors (p\u3c.05) for hang duration. There were no significant differences for EMGPK among repetitions or between recovery conditions (p\u3e.05). EMGAREA decreased initially with repeated hangs during both R1 and R3 but this trend tended to plateau at repetition 3 for the R3 condition. A significant difference was found in EMGAREA for both recovery conditions and trials (p\u3c.05) as well as a significant interaction of the two factors (p\u3c.05). Mean FF decreased between pre- and post-hangs for both R1 and R3 however the difference was not significant. It was concluded that the overall decline in hang time is less with 3 min recovery vs 1 min recovery between hangs. Peak EMG does not appear to change despite this evidence of fatigue. A 3 min recovery interval between hang repetitions decreases the magnitude of fatigue experienced and enables a greater EMGAREA per hang

    Safety and feasibility of NeuroFlo use in eight- to 24-hour ischemic stroke patients.

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    BACKGROUND: Acute treatment of ischemic stroke patients presenting more than eight-hours after symptom onset remains limited and largely unproven. Partial aortic occlusion using the NeuroFlo catheter can augment cerebral perfusion in animals. We investigated the safety and feasibility of employing this novel catheter to treat ischemic stroke patients eight-hours to 24 h following symptom onset. METHODS: A multicenter, single-arm trial enrolled ischemic stroke patients at nine international academic medical centers. Eligibility included age 18-85 years old, National Institutes of Health stroke scale (NIHSS) score between four and 20, within eight-hours to 24 h after symptom onset, and perfusion-diffusion mismatch confirmed by magnetic resonance imaging. The primary outcome was all adverse events occurring from baseline to 30 days posttreatment. Secondary outcomes included stroke severity on neurological indices through 90 days. This study is registered with ClinicalTrials.gov, number NCT00436592. RESULTS: A total of 26 patients were enrolled. Of these, 25 received treatment (one excluded due to aortic morphology); five (20%) died. Favorable neurological outcome at 90 days (modified Rankin score 0-2 vs. 3-6) was associated with lower baseline NIHSS (P < 0·001) and with longer duration from symptom discovery to treatment. There were no symptomatic intracranial hemorrhages or parenchymal hematomas. Asymptomatic intracranial hemorrhage was visible on computed tomography in 32% and only on microbleed in another 20%. CONCLUSIONS: Partial aortic occlusion using the NeuroFlo catheter, a novel collateral therapeutic strategy, appears safe and feasible in stroke patients eight-hours to 24 h after symptom onset

    miR-132-3p and KLF7 as novel regulators of aortic stiffening-associated EndMT in type 2 diabetes mellitus

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    Background: The prevalence of diabetes mellitus has risen considerably and currently affects more than 422 million people worldwide. Cardiovascular diseases including myocardial infarction and heart failure represent the major cause of death in type 2 diabetes (T2D). Diabetes patients exhibit accelerated aortic stiffening which is an independent predictor of cardiovascular disease and mortality. We recently showed that aortic stiffness precedes hypertension in a mouse model of diabetes (db/db mice), making aortic stiffness an early contributor to cardiovascular disease development. Elucidating how aortic stiffening develops is a pressing need in order to halt the pathophysiological process at an early time point. Methods: To assess EndMT occurrence, we performed co-immunofluorescence staining of an endothelial marker (CD31) with mesenchymal markers (α-SMA/S100A4) in aortic sections from db/db mice. Moreover, we performed qRT-PCR to analyze mRNA expression of EndMT transcription factors in aortic sections of db/db mice and diabetic patients. To identify the underlying mechanism by which EndMT contributes to aortic stiffening, we used aortas from db/db mice and diabetic patients in combination with high glucose-treated human umbilical vein endothelial cells (HUVECs) as an in vitro model of diabetes-associated EndMT. Results: We demonstrate robust CD31/α-SMA and CD31/S100A4 co-localization in aortic sections of db/db mice which was almost absent in control mice. Moreover, we demonstrate a significant upregulation of EndMT transcription factors in aortic sections of db/db mice and diabetic patients. As underlying regulator, we identified miR-132-3p as the most significantly downregulated miR in the micronome of db/db mice and high glucose-treated HUVECs. Indeed, miR-132-3p was also significantly downregulated in aortic tissue from diabetic patients. We identified Kruppel-like factor 7 (KLF7) as a target of miR-132-3p and show a significant upregulation of KLF7 in aortic sections of db/db mice and diabetic patients as well as in high glucose-treated HUVECs. We further demonstrate that miR-132-3p overexpression and KLF7 downregulation ameliorates EndMT in high glucose-treated HUVECs. Conclusions: We demonstrate for the first time that EndMT contributes to aortic stiffening in T2D. We identified miR-132-3p and KLF7 as novel EndMT regulators in this context. Altogether, this gives us new insights in the development of aortic stiffening in T2D.</p

    Angioplasty in acute middle cerebral artery stroke due to atrial fibrillation selected by CT perfusion: a case report

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    We report the experience of a case of acute stroke in a patient affected by Rendu Osler syndrome and atrial fibrillation. The combination of dynamic computerized tomography perfusion scans and the use of a high-compliance balloon allowed increasing the treatment window for intra-arterial recanalization over 6 h after stroke onset in a patient with middle cerebral artery occlusion

    Reduced Mortality and Severe Disability Rates in the SENTIS Trial

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    The Safety and Efficacy of NeuroFlo Technology in Ischemic Stroke trial showed a trend for reduced all-cause mortality and positive secondary safety end point outcomes. We present further analyses of the mortality and severe disability data from the Safety and Efficacy of NeuroFlo Technology in Ischemic Stroke trial

    Barrier dysfunction or drainage reduction: differentiating causes of CSF protein increase

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    BACKGROUND Cerebrospinal fluid (CSF) protein analysis is an important element in the diagnostic chain for various central nervous system (CNS) pathologies. Among multiple existing approaches to interpreting measured protein levels, the Reiber diagram is particularly robust with respect to physiologic inter-individual variability, as it uses multiple subject-specific anchoring values. Beyond reliable identification of abnormal protein levels, the Reiber diagram has the potential to elucidate their pathophysiologic origin. In particular, both reduction of CSF drainage from the cranio-spinal space as well as blood-CNS barrier dysfunction have been suggested ρas possible causes of increased concentration of blood-derived proteins. However, there is disagreement on which of the two is the true cause. METHODS We designed two computational models to investigate the mechanisms governing protein distribution in the spinal CSF. With a one-dimensional model, we evaluated the distribution of albumin and immunoglobulin G (IgG), accounting for protein transport rates across blood-CNS barriers, CSF dynamics (including both dispersion induced by CSF pulsations and advection by mean CSF flow) and CSF drainage. Dispersion coefficients were determined a priori by computing the axisymmetric three-dimensional CSF dynamics and solute transport in a representative segment of the spinal canal. RESULTS Our models reproduce the empirically determined hyperbolic relation between albumin and IgG quotients. They indicate that variation in CSF drainage would yield a linear rather than the expected hyperbolic profile. In contrast, modelled barrier dysfunction reproduces the experimentally observed relation. CONCLUSIONS High levels of albumin identified in the Reiber diagram are more likely to originate from a barrier dysfunction than from a reduction in CSF drainage. Our in silico experiments further support the hypothesis of decreasing spinal CSF drainage in rostro-caudal direction and emphasize the physiological importance of pulsation-driven dispersion for the transport of large molecules in the CSF
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