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Stem cells such as mesenchymal stem cells (MSCs) enhance neurological recovery in preclinical stroke models by secreting extracellular vesicles (EVs). Since previous reports have focused on the application of MSC-EVs only, the role of the most suitable host cell for EV enrichment and preclinical stroke treatment remains elusive. The present study aimed to evaluate the therapeutic potential of EVs derived from neural progenitor cells (NPCs) following experimental stroke. Using the PEG technique, EVs were enriched and characterized by electron microscopy, proteomics, rt-PCR, nanosight tracking analysis, and Western blotting. Different dosages of NPC-EVs displaying a characteristic profile in size, shape, cargo protein, and non-coding RNA contents were incubated in the presence of cerebral organoids exposed to oxygen-glucose deprivation (OGD), significantly reducing cell injury when compared with control organoids. Systemic administration of NPC-EVs in male C57BL6 mice following experimental ischemia enhanced neurological recovery and neuroregeneration for as long as 3 months. Interestingly, the therapeutic impact of such NPC-EVs was found to be not inferior to MSC-EVs. Flow cytometric analyses of blood and brain samples 7 days post-stroke demonstrated increased blood concentrations of B and T lymphocytes after NPC-EV delivery, without affecting cerebral cell counts. Likewise, a biodistribution analysis after systemic delivery of NPC-EVs revealed the majority of NPC-EVs to be found in extracranial organs such as the liver and the lung. This proof-of-concept study supports the idea of EVs being a general concept of stem cell-induced neuroprotection under stroke conditions, where EVs contribute to reverting the peripheral post-stroke immunosuppression.
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Modelos Animales de Enfermedad , Vesículas Extracelulares/trasplante , Células-Madre Neurales/trasplante , Accidente Cerebrovascular/terapia , Animales , Animales Recién Nacidos , Células Cultivadas , Vesículas Extracelulares/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Células-Madre Neurales/fisiología , Organoides/fisiología , Organoides/trasplante , Accidente Cerebrovascular/inmunología , Accidente Cerebrovascular/patología , Resultado del TratamientoRESUMEN
INTRODUCTION: Appropriately selecting patients with chronic pancreatitis associated with pancreas divisum (PD) for endoscopic retrograde cholangiopancreatography (ERCP)-based therapy versus surgery remains difficult. The objective of this study was to identify factors that predict success or failure of ERCP for treatment of chronic pancreatitis in PD. METHODS: Patients undergoing ERCP for a diagnosis of PD and pancreatitis between 2008 and 2016 were identified and grouped according to whether they required one or two ERCPs or three or more ERCPs. Groups were compared along demographic, diagnostic, laboratory, ERCP-related, and outcome variables. RESULTS: Patients requiring 1-2 ERCPs were less likely to have back pain on initial presentation (4 vs. 24%, p = 0.02) and less likely to have a dilated bile duct on imaging prior to their first ERCP (8 vs. 30%, p = 0.04) than those requiring 3+ ERCPs. Patients requiring 1-2 ERCPs were also less likely to eventually require operative intervention for treatment of their chronic pancreatitis than those requiring 3+ ERCPs (24 vs. 44%, p = 0.047). On multivariable analysis, a dilated bile duct (odds ratio (OR) = 6.0, 95% confidence interval (CI) = 1.01-36.0, p = 0.048) was independently associated with requiring 3+ ERCPs. Back pain (OR = 6.3, 95% CI = 0.73-54.2, p = 0.09) trended toward but did not reach statistical significance for being independently associated with requiring 3+ ERCPs. CONCLUSIONS: The success of endoscopic treatment of chronic pancreatitis in patients with PD is dependent on proper patient selection. Patients with a dilated bile duct and back pain upon presentation may not respond well to endoscopic treatment alone and are more likely to eventually require operative intervention. Consideration should be given to early operative intervention in these patients.
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Páncreas , Pancreatitis Crónica , Colangiopancreatografia Retrógrada Endoscópica , Humanos , Páncreas/diagnóstico por imagen , Páncreas/cirugía , Pancreatitis Crónica/complicaciones , Pancreatitis Crónica/diagnóstico por imagen , Pancreatitis Crónica/cirugíaRESUMEN
Whole blood, that is blood that is not manufactured into its component red blood cells (RBC) plasma, and platelets (PLT) units, was the mainstay of transfusion for many years until it was discovered that the component parts of a blood donation could be stored under different conditions thereby optimizing the storage length of each product. The use of low anti-A and -B titer group O whole blood (LTOWB) has recently been rediscovered for use in massively bleeding trauma patients. Whole blood has several advantages over conventional component therapy for these patients, including simplifying the logistics of the resuscitation, being more concentrated than whole blood that is reconstituted from conventional components, and providing cold-stored PLTs, amongst other benefits. While randomized controlled trials to determine the efficacy of using LTOWB in the resuscitation of massively bleeding trauma patients are currently underway, retrospective data has shown that massively bleeding recipients of LTOWB with traumatic injury do not have worse outcomes compared to patients who received conventional components and, in some cases, recipients of LTOWB have more favourable outcomes. This paper will describe some of the advantages of using LTOWB and will discuss the emerging evidence for its use in massively bleeding patients.
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Transfusión Sanguínea/métodos , Hemorragia/terapia , Enfermedad Aguda , Anticoagulantes/efectos adversos , Tipificación y Pruebas Cruzadas Sanguíneas/métodos , Conservación de la Sangre/métodos , Sustitutos Sanguíneos/efectos adversos , Sustitutos Sanguíneos/uso terapéutico , Citratos/efectos adversos , Soluciones Cristaloides/efectos adversos , Soluciones Cristaloides/uso terapéutico , Servicios Médicos de Urgencia , Glucosa/efectos adversos , Hemorragia/etiología , Humanos , Procedimientos de Reducción del Leucocitos , Resucitación , Choque Hemorrágico/etiología , Choque Hemorrágico/mortalidad , Choque Hemorrágico/terapia , Reacción a la Transfusión/prevención & control , Resultado del Tratamiento , Heridas y Lesiones/complicacionesRESUMEN
INTRODUCTION: Endovascular treatment for acute ischaemic stroke with large artery occlusion has become the standard of care. However, the question if a subgroup of patients, with a low cerebral blood volume Alberta Stroke Program Early CT score (CBV-ASPECTS) ≤ 7 should be excluded from endovascular treatment remains open. Therefore; we investigated the difference of outcome between patients who were treated by endovascular treatment vs patients who did not receive endovascular treatment. METHODS: We retrospectively analysed our stroke database for all patients who presented within six hours of onset with unfavourable imaging findings and who received endovascular treatment or best medical treatment alone. Unfavourable imaging was defined as a CBV-ASPECTS ≤ 7, which was an exclusion criterion for endovascular treatment at our institution before 2015. RESULTS: From 60 patients with an initial CBV-ASPECTS ≤ 7, 40 received best medical treatment and 20 were treated with endovascular treatment. Arterial hypertension and atrial fibrillation was more present in patients without endovascular treatment, the other baseline characteristics and percentage of patients treated with intravenous recombinant tissue plasminogen activator were not significantly different in both groups. At discharge, 40% of the interventional treated patients had a favourable outcome (eight of 20 (40%) vs six of 40 (15%; p = 0.031). The median values of the National Institute of Health Stroke Score and modified Rankin Scale at discharge were significantly lower in the treated cohort (6.5 (2.5-10.5) vs 16 (9.5-22.5); p = 0.006; 3 (0-5.5) vs 5 (4.5-5.5); p = 0.003). CONCLUSION: Patients with a CBV-ASPECTS ≤ 7 are likely to benefit from therapy and therefore may not be excluded from endovascular treatment. Further randomised trials are warranted to validate the data.
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Trombolisis Mecánica/métodos , Accidente Cerebrovascular/terapia , Anciano , Anciano de 80 o más Años , Angiografía Cerebral/métodos , Angiografía por Tomografía Computarizada/métodos , Procedimientos Endovasculares/métodos , Femenino , Humanos , Masculino , Tomografía Computarizada Multidetector/métodos , Selección de Paciente , Estudios Retrospectivos , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
PURPOSE: We compared the postnatal course, morbidity and early results after repair for cases of isolated or "pure" TEF with those for cases of esophageal atresia (EA) with distal tracheoesophageal fistula (TEF). METHODS: Twenty-four consecutive infants were divided into two groups: isolated TEF [TEF group] (n = 5) and EA with distal TEF [EA group] (n = 19). RESULTS: A high rate of prematurity (29%) and major cardiac and other surgically-relevant malformations (0.8 vs. 0.7 per infant) was found in both groups. The median age at surgery was 8 days for the TEF group vs. 1 day for the EA group (p < 0.01). Most infants of both cohorts had stable acid-base and respiratory parameters at admission. Generally, tracheoscopy provided valuable information regarding the position of the TEF. Surgery for isolated TEF was performed via right cervicotomy in 4 cases and via thoracotomy in one. Postoperative thoracostomy tubes were inserted in 3 cases and one emergency gastrostomy was created for acute gastric overextension (exclusively in patients with EA). The duration of postoperative mechanical ventilation (49 vs. 113 h, p = 0.045) and the median length of stay in the pediatric surgery unit (10 vs. 20.5 days, p = 0.003) were shorter for the isolated TEF group. Four EA patients experienced severe events. Total mortality was 8% (0 out of 5 with TEF vs. 2 out of 19 with EA). CONCLUSION: Developmental delay and a high rate of morbidity were found in both groups. More complex surgery increased perioperative morbidity in cases of EA. With early recognition of isolated TEF, a less complicated course can be expected in comparison with esophageal atresia.
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Atresia Esofágica/cirugía , Fístula Traqueoesofágica/cirugía , Endoscopía , Atresia Esofágica/complicaciones , Femenino , Gastrostomía , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Masculino , Morbilidad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/terapia , Toracostomía , Toracotomía , Fístula Traqueoesofágica/complicaciones , Resultado del TratamientoRESUMEN
BACKGROUND: Femoral hernias are an often unexpected groin pathology during childhood. However, the pediatric surgeon has to be aware to diagnose femoral hernia and to repair this condition. This is the first report on laparoscopic percutaneous extraperitoneal closure of femoral hernia (LPEF) in children and adolescents. METHODS: Over a 6-year period in a bi-institutional clinical study, we retrospectively identified six children and one young adult who underwent LPEF repair. RESULTS: Femoral hernia was laparoscopically confirmed in seven patients. Ages at surgery were 3, 5, 7, 7, 8, 8.5, and 18 years, respectively. In the first case, we combined laparoscopic diagnosis with open repair. In the consecutive six cases, hernias were repaired minimally invasively with the percutaneous extraperitoneal technique described below. During a follow-up between 6 years and 6 months, no recurrence was observed. SURGICAL TECHNIQUE: For LPEF, we percutaneously placed a peritoneal U-shape suture with integrated transfixation of the hernia sac, closed with an epifascial knot. We performed LPEF using two graspers. The peritoneum was percutaneously punctured with a venous cannula through which the suture was inserted. One grasper was inserted through the working channel of the laparoscope to invert the hernia sac into the abdominal cavity. A mini-grasping forceps inserted through the cannula retrieved the thread and completed LPEF. CONCLUSION: We demonstrate that single-port laparoscopic percutaneous extraperitoneal closure of femoral hernia is successful and quick in children and in adolescents.
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Hernia Femoral/cirugía , Herniorrafia/métodos , Adolescente , Niño , Preescolar , Femenino , Herniorrafia/instrumentación , Humanos , Laparoscopía/instrumentación , Laparoscopía/métodos , Masculino , Peritoneo/cirugía , Estudios Retrospectivos , Adulto JovenRESUMEN
The concept of whole blood (WB) as a treatment modality for trauma patients requiring transfusion therapy is not new. Successfully employed in the early 20 century, WB was the product of choice for military trauma resuscitation until the advent of component therapy changed the landscape of transfusion medicine. However, the recognition of the success of WB in the military operational setting has provided some enthusiasm to explore its revival as a cold-stored option in the civilian trauma resuscitation sector. Concerns continue to exist over potential limitations for its application in regards to the efficacy of platelets after cold storage, the risk of haemolytic transfusion reactions following the transfusion of un-cross-matched WB and the logistical issues for civilian blood banks in providing WB. This review aims to reconcile these concerns with data available in the literature, with a view to establishing that there is in vitro evidence supporting the haemostatic effects of cold-stored WB as a potential therapeutic option in both the pre-hospital and in-hospital civilian trauma resuscitation settings.
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Transfusión Sanguínea , Hemorragia/terapia , Reacción a la Transfusión/prevención & control , Heridas y Lesiones/terapiaRESUMEN
BACKGROUND: Alopecia areata (AA) is an autoimmune disorder whose pathogenesis involves the collapse of the relative immune privilege (IP) of the hair follicle (HF). Given that vasoactive intestinal peptide (VIP) is an immunoinhibitory neuropeptide released by perifollicular sensory nerve fibres, which play a role in IP maintenance, it may modulate human HF-IP and thus be therapeutically relevant for AA. OBJECTIVES: To answer the following questions: Do human HFs express VIP receptors, and does their stimulation protect from or restore experimentally induced HF-IP collapse? Is VIP signalling defective in AA HFs? METHODS: Firstly, VIP and VIP receptor (VPAC1, VPAC2) expression in human scalp HFs and AA skin was assessed. In HF organ culture, we then explored whether VIP treatment can restore and/or protect from interferon-γ-induced HF-IP collapse, assessing the expression of the key IP markers by quantitative (immuno-)histomorphometry. RESULTS: Here we provide the first evidence that VIP receptors are expressed in the epithelium of healthy human HFs at the gene and protein level. Furthermore, VIP receptor protein expression, but not VIP(+) nerve fibres, is significantly downregulated in lesional hair bulbs of patients with AA, suggesting defects in VIP receptor-mediated signalling. Moreover, we show that VIP protects the HF from experimentally induced IP collapse in vitro, but does not fully restore it once collapsed. CONCLUSIONS: These pilot data suggest that insufficient VIP receptor-mediated signalling may contribute to impairing HF-IP in patients with AA, and that VIP is a promising candidate 'HF-IP guardian' that may be therapeutically exploited to inhibit the progression of AA lesions.
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Alopecia Areata/inmunología , Folículo Piloso/inmunología , Péptido Intestinal Vasoactivo/fisiología , Epitelio/metabolismo , Femenino , Voluntarios Sanos , Humanos , Interferón gamma/farmacología , Proyectos Piloto , ARN Mensajero/metabolismo , Receptores de Tipo II del Péptido Intestinal Vasoactivo/metabolismo , Receptores de Tipo I del Polipéptido Intestinal Vasoactivo/metabolismo , Cuero Cabelludo/inmunología , Autotolerancia/inmunología , Péptido Intestinal Vasoactivo/metabolismoRESUMEN
This study was carried out to investigate the effect of mannitol, sorbitol and sucrose as osmotic agents on in vitro conservation of embryogenic cultures of date palm (Phoenix dactylifera, L.) Bartamoda and Sakkoty cultivars. Embryogenic cultures was obtained using MS medium supplemented with 10 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D) and 3 mg/l isopentenyl adenine (2iP). Among the three types of osmotic substances used for slow growth conservation, sucrose at all concentrations gave the highest percentage of survival with Sakkoty cultivar. However, addition of 40 g/l or 60 g/l mannitol and 20 g/l sorbitol showed the highest percentage of survival percentage with Bartamoda cultivar. The different sucrose concentrations caused higher numbers of germinated embryos of the two cultivars compared with mannitol or sorbitol. Also, the number of germinated embryos was increased with increasing the storage periods till the ninth month. Genetic stability was determined using random amplified polymorphic DNA (RAPD) analysis. There were no clear genetic differences between the two osmotic agents used for preservation. The preserved cultures of Sakkoty cultivar gave the high percent of similarity while Bartamoda cultivar gave low percent of similarity. From the obtained results we can recommend using 40 g/l mannitol or 20 g/l sorbitol for in vitro preservation of Bartamoda cultivar of date palm and 20 g/l of sucrose for Sakkoty cultivar.
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Although cellular prion protein (PrP(c)) has been suggested to have physiological roles in neurogenesis and angiogenesis, the pathophysiological relevance of both processes remain unknown. To elucidate the role of PrP(c) in post-ischemic brain remodeling, we herein exposed PrP(c) wild type (WT), PrP(c) knockout (PrP-/-) and PrP(c) overexpressing (PrP+/+) mice to focal cerebral ischemia followed by up to 28 days reperfusion. Improved neurological recovery and sustained neuroprotection lasting over the observation period of 4 weeks were observed in ischemic PrP+/+ mice compared with WT mice. This observation was associated with increased neurogenesis and angiogenesis, whereas increased neurological deficits and brain injury were noted in ischemic PrP-/- mice. Proteasome activity and oxidative stress were increased in ischemic brain tissue of PrP-/- mice. Pharmacological proteasome inhibition reversed the exacerbation of brain injury induced by PrP-/-, indicating that proteasome inhibition mediates the neuroprotective effects of PrP(c). Notably, reduced proteasome activity and oxidative stress in ischemic brain tissue of PrP+/+ mice were associated with an increased abundance of hypoxia-inducible factor 1α and PACAP-38, which are known stimulants of neural progenitor cell (NPC) migration and trafficking. To elucidate effects of PrP(c) on intracerebral NPC homing, we intravenously infused GFP(+) NPCs in ischemic WT, PrP-/- and PrP+/+ mice, showing that brain accumulation of GFP(+) NPCs was greatly reduced in PrP-/- mice, but increased in PrP+/+ animals. Our results suggest that PrP(c) induces post-ischemic long-term neuroprotection, neurogenesis and angiogenesis in the ischemic brain by inhibiting proteasome activity.
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Isquemia Encefálica/metabolismo , Células-Madre Neurales/metabolismo , Neuronas/metabolismo , Neuronas/patología , Priones/metabolismo , Animales , Isquemia Encefálica/patología , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Transgénicos , Células-Madre Neurales/patología , Neurogénesis/efectos de los fármacos , Fármacos Neuroprotectores/farmacologíaRESUMEN
Many neuropathological and experimental studies suggest that the degeneration of dopaminergic terminals and axons precedes the demise of dopaminergic neurons in the substantia nigra, which finally results in the clinical symptoms of Parkinson disease (PD). The mechanisms underlying this early axonal degeneration are, however, still poorly understood. Here, we examined the effects of overexpression of human wildtype alpha-synuclein (αSyn-WT), a protein associated with PD, and its mutant variants αSyn-A30P and -A53T on neurite morphology and functional parameters in rat primary midbrain neurons (PMN). Moreover, axonal degeneration after overexpression of αSyn-WT and -A30P was analyzed by live imaging in the rat optic nerve in vivo. We found that overexpression of αSyn-WT and of its mutants A30P and A53T impaired neurite outgrowth of PMN and affected neurite branching assessed by Sholl analysis in a variant-dependent manner. Surprisingly, the number of primary neurites per neuron was increased in neurons transfected with αSyn. Axonal vesicle transport was examined by live imaging of PMN co-transfected with EGFP-labeled synaptophysin. Overexpression of all αSyn variants significantly decreased the number of motile vesicles and decelerated vesicle transport compared with control. Macroautophagic flux in PMN was enhanced by αSyn-WT and -A53T but not by αSyn-A30P. Correspondingly, colocalization of αSyn and the autophagy marker LC3 was reduced for αSyn-A30P compared with the other αSyn variants. The number of mitochondria colocalizing with LC3 as a marker for mitophagy did not differ among the groups. In the rat optic nerve, both αSyn-WT and -A30P accelerated kinetics of acute axonal degeneration following crush lesion as analyzed by in vivo live imaging. We conclude that αSyn overexpression impairs neurite outgrowth and augments axonal degeneration, whereas axonal vesicle transport and autophagy are severely altered.
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Neuronas Dopaminérgicas/metabolismo , Degeneración Nerviosa/genética , Enfermedad de Parkinson/genética , alfa-Sinucleína/biosíntesis , Sustitución de Aminoácidos , Animales , Autofagia/genética , Axones/patología , Dopamina/metabolismo , Neuronas Dopaminérgicas/patología , Regulación de la Expresión Génica , Humanos , Neuritas/patología , Enfermedad de Parkinson/patología , Ratas , Sustancia Negra/metabolismo , Sustancia Negra/patología , alfa-Sinucleína/genéticaRESUMEN
Intravenous transplantation of neural progenitor cells (NPCs) induces functional recovery after stroke, albeit grafted cells are not integrated into residing neural networks. However, a systematic analysis of intravenous NPC delivery at acute and post-acute time points and their long-term consequences does not exist. Male C57BL6 mice were exposed to cerebral ischemia, and NPCs were intravenously grafted on day 0, on day 1 or on day 28. Animals were allowed to survive for up to 84 days. Mice and tissues were used for immunohistochemical analysis, flow cytometry, ELISA and behavioral tests. Density of grafted NPCs within the ischemic hemisphere was increased when cells were transplanted on day 28 as compared with transplantation on days 0 or 1. Likewise, transplantation on day 28 yielded enhanced neuronal differentiation rates of grafted cells. Post-ischemic brain injury, however, was only reduced when NPCs were grafted at acute time points. On the contrary, reduced post-ischemic functional deficits due to NPC delivery were independent of transplantation paradigms. NPC-induced neuroprotection after acute cell delivery was due to stabilization of the blood-brain barrier (BBB), reduction in microglial activation and modulation of both peripheral and central immune responses. On the other hand, post-acute NPC transplantation stimulated post-ischemic regeneration via enhanced angioneurogenesis and increased axonal plasticity. Acute NPC delivery yields long-term neuroprotection via enhanced BBB integrity and modulation of post-ischemic immune responses, whereas post-acute NPC delivery increases post-ischemic angioneurogenesis and axonal plasticity. Post-ischemic functional recovery, however, is independent of NPC delivery timing, which offers a broad therapeutic time window for stroke treatment.
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Encéfalo/fisiología , Células-Madre Neurales/trasplante , Accidente Cerebrovascular/terapia , Animales , Barrera Hematoencefálica/metabolismo , Diferenciación Celular , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos C57BL , Actividad Motora , Células-Madre Neurales/citología , Neurogénesis , Recuperación de la Función , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/patología , Trasplante HomólogoRESUMEN
The Rho/ROCK/LIMK pathway is central for the mediation of repulsive environmental signals in the central nervous system. Several studies using pharmacological Rho-associated protein kinase (ROCK) inhibitors have shown positive effects on neurite regeneration and suggest additional pro-survival effects in neurons. However, as none of these drugs is completely target specific, it remains unclear how these effects are mediated and whether ROCK is really the most relevant target of the pathway. To answer these questions, we generated adeno-associated viral vectors to specifically downregulate ROCK2 and LIM domain kinase (LIMK)-1 in rat retinal ganglion cells (RGCs) in vitro and in vivo. We show here that specific knockdown of ROCK2 and LIMK1 equally enhanced neurite outgrowth of RGCs on inhibitory substrates and both induced substantial neuronal regeneration over distances of more than 5 mm after rat optic nerve crush (ONC) in vivo. However, only knockdown of ROCK2 but not LIMK1 increased survival of RGCs after optic nerve axotomy. Moreover, knockdown of ROCK2 attenuated axonal degeneration of the proximal axon after ONC assessed by in vivo live imaging. Mechanistically, we demonstrate here that knockdown of ROCK2 resulted in decreased intraneuronal activity of calpain and caspase 3, whereas levels of pAkt and collapsin response mediator protein 2 and autophagic flux were increased. Taken together, our data characterize ROCK2 as a specific therapeutic target in neurodegenerative diseases and demonstrate new downstream effects of ROCK2 including axonal degeneration, apoptosis and autophagy.
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Degeneración Nerviosa , Regeneración Nerviosa , Traumatismos del Nervio Óptico/enzimología , Nervio Óptico/enzimología , Células Ganglionares de la Retina/enzimología , Quinasas Asociadas a rho/metabolismo , Animales , Apoptosis , Autofagia , Axones/enzimología , Axones/patología , Calpaína/metabolismo , Caspasa 3/metabolismo , Muerte Celular , Células Cultivadas , Dependovirus/genética , Modelos Animales de Enfermedad , Femenino , Técnicas de Silenciamiento del Gen , Técnicas de Transferencia de Gen , Vectores Genéticos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Quinasas Lim/genética , Quinasas Lim/metabolismo , Compresión Nerviosa , Proteínas del Tejido Nervioso/metabolismo , Neuritas/enzimología , Neuritas/patología , Nervio Óptico/patología , Nervio Óptico/fisiopatología , Traumatismos del Nervio Óptico/genética , Traumatismos del Nervio Óptico/patología , Traumatismos del Nervio Óptico/fisiopatología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , Ratas , Ratas Wistar , Células Ganglionares de la Retina/patología , Transducción de Señal , Factores de Tiempo , Transfección , Quinasas Asociadas a rho/genéticaRESUMEN
Magnonics as an emerging nanotechnology offers functionalities beyond current semiconductor technology. Spin waves used in cellular nonlinear networks are expected to speed up technologically, demanding tasks such as image processing and speech recognition at low power consumption. However, efficient coupling to microelectronics poses a vital challenge. Previously developed techniques for spin-wave excitation (for example, by using parametric pumping in a cavity) may not allow for the relevant downscaling or provide only individual point-like sources. Here we demonstrate that a grating coupler of periodically nanostructured magnets provokes multidirectional emission of short-wavelength spin waves with giantly enhanced amplitude compared with a bare microwave antenna. Exploring the dependence on ferromagnetic materials, lattice constants and the applied magnetic field, we find the magnonic grating coupler to be more versatile compared with gratings in photonics and plasmonics. Our results allow one to convert, in particular, straight microwave antennas into omnidirectional emitters for short-wavelength spin waves, which are key to cellular nonlinear networks and integrated magnonics.
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BACKGROUND: Gastrointestinal endoscopies are increasingly being carried out with sedation. All of the drugs used for sedation are associated with a certain risk of complications. Data currently available on sedation-associated morbidity and mortality rates are limited and in most cases have substantial methodological limitations. The aim of this study was to record severe sedation-associated complications in a large number of gastrointestinal endoscopies. METHODS: Data on severe sedation-associated complications were collected on a multicentre basis from prospectively recorded registries of complications in the participating hospitals (median documentation period 27 months, range 9 - 129 months). RESULTS: Data for 388,404 endoscopies from 15 departments were included in the study. Severe sedation-associated complications occurred in 57 patients (0.01 %). Forty-one percent of the complications and 50 % of all complications with a fatal outcome (10/20 patients) occurred during emergency endoscopies. In addition, it was found that 95 % of the complications and 100 % of all fatal complications affected patients in ASA class ≥ 3. CONCLUSIONS: Including nearly 400,000 endoscopies, this study represents the largest prospective, multicenter record of the complications of sedation worldwide. The analysis shows that sedation is carried out safely in gastrointestinal endoscopy. The morbidity and mortality rates are much lower than previously reported in the literature in similar groups of patients. Risk factors for the occurrence of serious complications include emergency examinations and patients in ASA class ≥ 3.