Monocyte transplantation for neural and cardiovascular ischemia repair

Neovascularization is an integral process of inflammatory reactions and subsequent repair cascades in tissue injury. Monocytes/macrophages play a key role in the inflammatory process including angiogenesis as well as the defence mechanisms by exerting microbicidal and immunomodulatory activity. Current studies have demonstrated that recruited monocytes/macrophages aid in regulating angiogenesis in ischemic tissue, tumours and chronic inflammation. in terms of neovascularization followed by tissue regeneration, monocytes/macrophages should be highly attractive for cell-based therapy compared to any other stem cells due to their considerable advantages: non-oncogenic, non-teratogenic, multiple secretary functions including pro-angiogenic and growth factors, straightforward cell harvesting procedure and non-existent ethical controversy. in addition to adult origins such as bone marrow or peripheral blood, umbilical cord blood (UCB) can be a potential source for autologous or allogeneic monocytes/macrophages. Especially, UCB monocytes should be considered as the first candidate owing to their feasibility, low immune rejection and multiple characteristic advantages such as their anti-inflammatory properties by virtue of their unique immune and inflammatory immaturity, and their proangiogenic ability. in this review, we present general characteristics and potential of monocytes/macrophages for cell-based therapy, especially focusing on neovascularization and UCB-derived monocytes.Univ S Florida, Dept Neurosurg & Brain Repair, Ctr Excellence Aging & Brain Repair, Coll Med, Tampa, FL 33612 USAUniv S Florida, Off Res & Innovat, Tampa, FL 33612 USASaneron CCEL Therapeut INC, Tampa, FL USAPolo Biotecnol Rio Janeiro, BioRio, Cryopraxis & Silvestre Lab, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, Paulista Sch Med, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, Paulista Sch Med, São Paulo, BrazilWeb of Scienc

Mild Inactivation of RE-1 Silencing Transcription Factor (REST) Reduces Susceptibility to Kainic Acid-Induced Seizures

RE-1 Silencing Transcription factor (REST) controls several steps in neural development by modulating the expression of a wide range of neural genes. Alterations in REST expression have been associated with the onset of epilepsy; however, whether such alterations are deleterious or represent a protective homeostatic response remains elusive. To study the impact of REST modulation on seizure propensity, we developed a tool for its negative modulation in vivo. The tool is composed of the paired-amphipathic helix 1 (PAH1) domain, a competitive inhibitor of REST activation by mSin3, fused to the light-oxygen-voltage sensing 2 (LOV2) domain of Avena sativa phototropin 1, a molecular switch to alternatively hide or expose the PAH1 inhibitor. We employed the C450A and I539E light-independent AsLOV2 variants to mimic the closed (inactive) and open (active) states of LOV2-PAH1, respectively. Recombinant AAV1/2 viral particles (rAAVs) allowed LOV2-PAH1 expression in HEK293T cells and primary neurons, and efficiently transduced hippocampal neurons in vivo. mRNA expression analysis revealed an increased expression of several neuronal genes in the hippocampi of mice expressing the open probe. AAV-transduced mice received a single dose of kainic acid (KA), a treatment known to induce a transient increase of REST levels in the hippocampus. Remarkably, mice expressing the active variant displayed a reduced number of KA-induced seizures, which were less severe compared to mice carrying the inactive probe. These data support the validity of our tool to modulate REST activity in vivo and the potential impact of REST modulation on epileptogenesis

Review and Outlook on GaN and SiC Power Devices: Industrial State-of-the-Art, Applications, and Perspectives

We present a comprehensive review and outlook of silicon carbide (SiC) and gallium nitride (GaN) transistors available on the market for current and next-generation power electronics. Material properties and structural differences among GaN and SiC devices are first discussed. Based on the analysis of different commercially available GaN and SiC power transistors, we describe the state-of-the-art of these technologies, highlighting the preferential power conversion topologies and the key characteristics of each technological platform. Current and future fields of application for GaN and SiC devices are also reviewed. The article also reports on the main reliability aspects related to both technologies. For GaN HEMTs, threshold voltage stability, dynamic ON-resistance, and breakdown limitation are described, whereas for SiC MOSFETs the analysis also focuses on gate oxide failure and short-circuit (SC) robustness. Finally, we give an overview on the perspective of such materials in different fields of interest. An indication of possible future improvements and developments for both technologies is drawn. The requirements for hybrid converters, along with a careful optimization of performance and the use of innovative optimization tools, are underlined

Relato de Caso Anatomical and clinical aspects of the blood supply of the sinoatrial node

SUMMARY -BACKGROUND. The recent study of the variations of the origin of the sinoatrial node and on the "arterial network of the perinodal sinusal area" in normal hearts points out the importance of this network. PURPOSE. Report on a case of patient with syncope of ischemic etiology. CONCLUSION. In this patient the arterial network did not protect the node from the ischemia caused by the obstruction of the artery of the sinoatrial node

Annexin A1-dependent tethering promotes extracellular vesicle aggregation revealed with single–extracellular vesicle analysis

Extracellular vesicles (EVs) including plasma membrane-derived microvesicles and endosomal-derived exosomes aggregate by unknown mechanisms, forming microcalcifications that promote cardiovascular disease, the leading cause of death worldwide. Here, we show a framework for assessing cell-independent EV mechanisms in disease by suggesting that annexin A1 (ANXA1)-dependent tethering induces EV aggregation and microcalcification. We present single-EV microarray, a method to distinguish microvesicles from exosomes and assess heterogeneity at a single-EV level. Single-EV microarray and proteomics revealed increased ANXA1 primarily on aggregating and calcifying microvesicles. ANXA1 vesicle aggregation was suppressed by calcium chelation, altering pH, or ANXA1 neutralizing antibody. ANXA1 knockdown attenuated EV aggregation and microcalcification formation in human cardiovascular cells and acellular three-dimensional collagen hydrogels. Our findings explain why microcalcifications are more prone to form in vulnerable regions of plaque, regulating critical cardiovascular pathology, and likely extend to other EV-associated diseases, including autoimmune and neurodegenerative diseases and cancer

Analysis of defect-related optical degradation of VCSILs for photonic integrated circuits

Laser diodes are of paramount importance for on-chip telecommunications applications, and a wide range of sensing devices that require near-infrared sources. In this work, the devices under test are vertical-cavity silicon-integrated lasers (VCSILs) designed for operation at 845 nm in photonic integrated circuits (PICs). We focus on the analysis of the degradation of the optical performance during aging. To investigate the reliability of the devices, we carried out several stress tests at constant current, ranging from 3.5 mA to 4.5 mA representing a highly accelerated stress condition. We observed two different degradation modes. In the first part of the experiments, the samples exhibited a worsening of the threshold current, but the sub-threshold emission was unaffected by degradation. We associated this behavior to the diffusion of impurities that, from the p-contact, were crossing the upper mirror implying a worsening of the DBR optical absorption. In the second stage of the stress test, the devices showed a higher degradation rate of the threshold current, whose variation was found to be linearly correlated to the worsening of the sub-threshold emission. We related this second degradation mode to the migration of the same impurities degrading the top DBR that, when reaching the active region of the laser, induced an increase in the non-radiative recombination rate. In addition to that, we related the two degradation modes to the change in series resistance, which was ascribed to the resistivity increment of the top DBR first and of oxide aperture afterwards

Nanoanalytical analysis of bisphosphonate-driven alterations of microcalcifications using a 3D hydrogel system and in vivo mouse model

Vascular calcification predicts atherosclerotic plaque rupture and cardiovascular events. Retrospective studies of women taking bisphosphonates (BiPs), a proposed therapy for vascular calcification, showed that BiPs paradoxically increased morbidity in patients with prior acute cardiovascular events but decreased mortality in event-free patients. Calcifying extracellular vesicles (EVs), released by cells within atherosclerotic plaques, aggregate and nucleate calcification. We hypothesized that BiPs block EV aggregation and modify existing mineral growth, potentially altering microcalcification morphology and the risk of plaque rupture. Three-dimensional (3D) collagen hydrogels incubated with calcifying EVs were used to mimic fibrous cap calcification in vitro, while an ApoE-/- mouse was used as a model of atherosclerosis in vivo. EV aggregation and formation of stress-inducing microcalcifications was imaged via scanning electron microscopy (SEM) and atomic force microscopy (AFM). In both models, BiP (ibandronate) treatment resulted in time-dependent changes in microcalcification size and mineral morphology, dependent on whether BiP treatment was initiated before or after the expected onset of microcalcification formation. Following BiP treatment at any time, microcalcifications formed in vitro were predicted to have an associated threefold decrease in fibrous cap tensile stress compared to untreated controls, estimated using finite element analysis (FEA). These findings support our hypothesis that BiPs alter EV-driven calcification. The study also confirmed that our 3D hydrogel is a viable platform to study EV-mediated mineral nucleation and evaluate potential therapies for cardiovascular calcification