176 research outputs found

    Opioid growth factor modulates angiogenesis

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    AbstractObjective: Induced angiogenesis has recently been attempted as a therapeutic modality in patients with occlusive arterial atherosclerotic disease. We investigated the possible role of endogenous opioids in the modulation of angiogenesis. Methods: Chick chorioallantoic membrane was used as an in vivo model to study angiogenesis. Fertilized chick eggs were incubated for 3 days, explanted, and incubated for an additional 2 days. Three-millimeter methylcellulose disks were placed on the surface of the chorioallantoic membrane; each disk contained opioid growth factor ([Met5]-enkephalin; 5 μg), the short-acting opioid receptor antagonist naloxone (5 μg), opioid growth factor and naloxone together (5 μg of each), the long-acting opioid antagonist naltrexone (5 μg), or distilled water (control). A second series of experiments was performed with distilled water, the angiogenic inhibitor retinoic acid (1 μg), and vascular endothelial growth factor (1 μg) to further evaluate our model. The developing vasculature was imaged 2 days later with a digital camera and exported to a computer for image analysis. Total number of blood vessels, total vessel length, and mean vessel length were measured within a 100-mm2 region surrounding each applied disk. Immunocytochemical analysis was performed with antibodies directed against opioid growth factor and its receptor (OGFr). Results: Opioid growth factor had a significant inhibitory effect on angiogenesis, both the number of blood vessels and the total vessel length being decreased (by 35% and 20%, respectively) in comparison with control levels (P <.005). The simultaneous addition of naloxone and opioid growth factor had no effect on blood vessel growth, nor did naloxone alone. Chorioallantoic membranes exposed to naltrexone displayed increases of 51% and 24% in blood vessel number and length, respectively, in comparison with control specimens (P <.005). These results indicate that the opioid growth factor effects are receptor mediated and tonically active. Immunocytochemistry demonstrated the presence of both opioid growth factor and OGFr within the endothelial cells and mesenchymal cells of the developing chorioallantoic membrane vessel wall. Retinoic acid significantly reduced the number and the total length of blood vessels, whereas vascular endothelial growth factor increased both the number and the length of blood vessels in comparison with the controls (P <.0001). The magnitude of opioid growth factor's effects were comparable to those seen with retinoic acid, whereas inhibition of opioid growth factor with naltrexone induced an increase in total vessel length comparable to that for vascular endothelial growth factor. Conclusions: These results demonstrate for the first time that endogenous opioids modulate in vivo angiogenesis. Opioid growth factor is a tonically active peptide that has a receptor-mediated action in regulating angiogenesis in developing endothelial and mesenchymal vascular cells. (J Vasc Surg 2000;32:364-73.

    The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines

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    The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of 20\sim 20 kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 700 kW of power. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the L/EL/E behaviour, and distinguishing effects arising from δCP\delta_{CP} and matter. In this paper we show how this comprehensive physics case can be further enhanced and complemented if a neutrino beam produced at the Protvino IHEP accelerator complex, at a distance of 1160 km, and with modest power of 450 kW is aimed towards the same far detectors. We show that the coupling of two independent sub-MW conventional neutrino and antineutrino beams at different baselines from CERN and Protvino will allow to measure CP violation in the leptonic sector at a confidence level of at least 3σ3\sigma for 50\% of the true values of δCP\delta_{CP} with a 20 kton detector. With a far detector of 70 kton, the combination allows a 3σ3\sigma sensitivity for 75\% of the true values of δCP\delta_{CP} after 10 years of running. Running two independent neutrino beams, each at a power below 1 MW, is more within today's state of the art than the long-term operation of a new single high-energy multi-MW facility, which has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure

    Muscle Fiber Viability, a Novel Method for the Fast Detection of Ischemic Muscle Injury in Rats

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    Acute lower extremity ischemia is a limb- and life-threatening clinical problem. Rapid detection of the degree of injury is crucial, however at present there are no exact diagnostic tests available to achieve this purpose. Our goal was to examine a novel technique - which has the potential to accurately assess the degree of ischemic muscle injury within a short period of time - in a clinically relevant rodent model. Male Wistar rats were exposed to 4, 6, 8 and 9 hours of bilateral lower limb ischemia induced by the occlusion of the infrarenal aorta. Additional animals underwent 8 and 9 hours of ischemia followed by 2 hours of reperfusion to examine the effects of revascularization. Muscle samples were collected from the left anterior tibial muscle for viability assessment. The degree of muscle damage (muscle fiber viability) was assessed by morphometric evaluation of NADH-tetrazolium reductase reaction on frozen sections. Right hind limbs were perfusion-fixed with paraformaldehyde and glutaraldehyde for light and electron microscopic examinations. Muscle fiber viability decreased progressively over the time of ischemia, with significant differences found between the consecutive times. High correlation was detected between the length of ischemia and the values of muscle fiber viability. After reperfusion, viability showed significant reduction in the 8-hour-ischemia and 2-hour-reperfusion group compared to the 8-hour-ischemia-only group, and decreased further after 9 hours of ischemia and 2 hours of reperfusion. Light- and electron microscopic findings correlated strongly with the values of muscle fiber viability: lesser viability values represented higher degree of ultrastructural injury while similar viability results corresponded to similar morphological injury. Muscle fiber viability was capable of accurately determining the degree of muscle injury in our rat model. Our method might therefore be useful in clinical settings in the diagnostics of acute ischemic muscle injury

    Radionuclide imaging of bone marrow disorders

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    Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as 99mTc-nanocolloid, 99mTc-sulphur colloid, 111In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using 18F-FDG and 18F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed

    Performance study of a 3 x 1 x 1 m(3) dual phase liquid Argon Time Projection Chamber exposed to cosmic rays

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    This work would not have been possible without the support of the Swiss National Science Foundation, Switzerland; CEA and CNRS/IN2P3, France; KEK and the JSPS program, Japan; Ministerio de Ciencia e Innovacion in Spain under grants FPA2016-77347-C2, SEV-2016-0588 and MdM-2015-0509, Comunidad de Madrid, the CERCA program of the Generalitat de Catalunya and the fellowship (LCF/BQ/DI18/11660043) from "La Caixa" Foundation (ID 100010434); the Programme PNCDI III, CERN-RO, under Contract 2/2020, Romania; the U.S. Department of Energy under Grant No. DE-SC0011686. This project has received funding from the European Union's Horizon 2020 Research and Innovation program under Grant Agreement no. 654168. The authors are also grateful to the French government operated by the National Research Agency (ANR) for the LABEX Enigmass, LABEX Lyon Institute of Origins (ANR-10-LABX-0066) of the Universite de Lyon for its financial support within the program "Investissements d'Avenir" (ANR-11-IDEX-0007).We report the results of the analyses of the cosmic ray data collected with a 4 tonne (3x1x1 m(3)) active mass (volume) Liquid Argon Time-Projection Chamber (TPC) operated in a dual-phase mode. We present a detailed study of the TPC's response, its main detector parameters and performance. The results are important for the understanding and further developments of the dual-phase technology, thanks to the verification of key aspects, such as the extraction of electrons from liquid to gas and their amplification through the entire one square metre readout plain, gain stability, purity and charge sharing between readout views.Swiss National Science Foundation (SNSF)French Atomic Energy CommissionCentre National de la Recherche Scientifique (CNRS)High Energy Accelerator Research Organization (KEK)Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of ScienceSpanish Government FPA2016-77347-C2 SEV-2016-0588MdM-2015-0509Comunidad de MadridCERCA program of the Generalitat de CatalunyaLa Caixa Foundation LCF/BQ/DI18/11660043 100010434Programme PNCDI III, RomaniaCERN-RO, Romania 2/2020United States Department of Energy (DOE) SC0011686European Commission 654168Universite de Lyon ANR-10-LABX-0066 ANR-11-IDEX-000

    Comparação termohigrométrica de sub-altitude em área urbana e rural em São Carlos, Brasil, por meio de VANT/DRONE.

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    A Radiossondagem de sub-altitude tem como objetivo mensurar os dados climatológicos em vários níveis verticais da atmosfera por meio de um equipamento denominado radiossonda. Além do mais, é conhecido que os diferentes tipos de uso e ocupação do solo (urbano, industrial, rural, florestal) alteram o balanço de energia entre a superfície e a atmosfera. Dessa forma, o estudo proposto tem como objetivo analisar e comparar os valores de temperatura e umidade relativa do ar próximo a superfície (1,5m de altura) e em diferentes alturas (50m e 190m da superfície) em área urbana e rural no município de São Carlos, Brasil, no período noturno em episódios de inverno, por meio de termohigrômetros acoplados em um Veículo Aéreo Não-Tripulado (Vant/Drone) do tipo quadricóptero (quatro hélices). O voo na área urbana foi realizado no dia 13/07/2018 e na área rural no dia 26/07/2018 entre 19:30 e 20:30. Os resultados demonstraram que na área urbana em períodos noturnos a temperatura e umidade relativa do ar são maiores próxima a superfície em relação aos dados de sub-altitude. Já na área rural em períodos noturnos a temperatura do ar é menor e a umidade relativa do ar é maior próximo a superfície em comparação aos dados de sub-altitude

    Current Concepts and Future Trends in Increasing the Benefits of Cochlear Implantation: A Narrative Review

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    Hearing loss is the most common neurosensory disorder, and with the constant increase in etiological factors, combined with early detection protocols, numbers will continue to rise. Cochlear implantation has become the gold standard for patients with severe hearing loss, and interest has shifted from implantation principles to the preservation of residual hearing following the procedure itself. As the audiological criteria for cochlear implant eligibility have expanded to include patients with good residual hearing, more attention is focused on complementary development of otoprotective agents, electrode design, and surgical approaches. The focus of this review is current aspects of preserving residual hearing through a summary of recent trends regarding surgical and pharmacological fundamentals. Subsequently, the assessment of new pharmacological options, novel bioactive molecules (neurotrophins, growth factors, etc.), nanoparticles, stem cells, and gene therapy are discussed
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