Sheep head frame validation for CT and MRI studies

Abstract IntroductionsAim of EDEN 2020 project’s Milestone 5 is the development of a steerable catheter for CED system in glioblastoma therapy. The VET group is involved in realization and validation of the proper animal model.Materials and methodsIn this part of the study two fresh sheep’s head from the local slaughter were used.The heads were located into an ad hoc Frame system based on anatomical measures and CT images, producted by Renishaw plc partner in this project. The frame was adapted and every components were checked for the ex vivo validation tests.CT imaging was taken in Lodi at Università degli studi di Milano, Facoltà di Medicina Veterinaria, with CT scanner and MRI imaging was taken in La Cittadina, CremonaResultsSystem validation was approved by the ex vivo trial.The frame system doesn’t compromise the imaging acquisition in MRI and CT systems.Every system components are functional to their aims.DiscussionThe Frame system is adapted to the sheep head. It is composed by elements able to lock the head during the imaging acquisition. Frame system is characterized by a support base helpings the animals to keep the head straight forward during imaging time, under general anesthesia. The design of these device support the airways anatomy, avoiding damaging or obstruction of airflows during anesthesia period.The role of elements like mouth bar and ovine head pins is to lock the head in a stable position during imaging acquisition; fixing is guaranteed by V shape head pins, that are arranged against the zygomatic arches. Lateral compression forces to the cranium, and the V shape pins avoid the vertical shifting of the head and any kind of rotations. (fig. 1

Sheep brain atlas creation. Diffusion tensor imaging and Scanning electron microscope in sheep brain analysis

IntroductionsAim of EDEN 2020 project is the development of a steerable catheter for CED system in glioblastoma therapy. The VET group is involved in realization and validation of the proper animal model.For surgical planning purpose a Diffusion Tensor Imaging (DTI) of white matter tracts in the sheep is necessary to identify the target points useful for the catheter introduction.The analysis of the sheep brain under a Scanning Electron Microscope (SEM) is required to understand any alterations due to the catheter introduction and to fluids injection during CED administration. Materials and methodsAnimals were treated in accordance with the European Communities Council directive (86/609/EEC), to the laws and regulations on animal welfare enclosed in D.L.G.S. 26/2014A total of five 70 kg female, one year old, sheep were used for the study.All animals, under general anesthesia, underwent to Magnetic Resonance Imaging (MRI) acquisition. MRI scanner used was Philips Ingenia 1.5 Tesla system.Once the DTI imaging were acquired the animals were euthanased, sheep brain was collected and samples of white matter tracts obtained with disposable biopsy punches of 1.5-2 mm of diameter.The samples were fixed, stained in Osmium tetroxide (OsO4) and then embedded with two different protocols (cold curing vs thermal curing) in resin for the Focused Ion Beam (FIB) SEM analyses. Results and discussionAll the DTI images were uploaded to TrackVis software and major white matter fiber tracts analysed. Corticospinal tract, visual radiation, fornix and fronto-occipital fasciculus were identified.Corticospinal tract was identified as major white matter tract in sheep brain and useful as target area for the research aims.For the SEM analysis the thermal protocol was recognised as better curing methods for the research purpose than cold curing one. ConclusionThe data acquired in this study are still submitted to analysis. AcknowledgmentThe project has received funding from the European Union’s EU Research and Innovation programme Horizon 2020 (no 688279)

Isolated slaughterhouse liver as model for normothermic perfusion after warm and cold ischemia: single case report

AbstractLiver transplantation is an ultimate procedure in patients suffering end-stage liver diseases. In these last years the donation after cardiac death (DCD) has increased the pool of potential liver donors. Different studies and procedures are involved in the prevention of the main ischemic problems during the reconditioning and resuscitation of the marginal livers. Normothermic extracorporeal liver perfusion (NELP) avoids prolonged cold storage damage that is the main cause of steatosis and biliary tract ischemia in transplanted patiens. Different porcine models have been studied and developed to understand the ischemia mechanism and to select the better technique for NELP.We conducted our study using a DCD pig liver model collected from slaughterhouse. Using extracorporeal membrane oxygenation, 2000 ml of total fluid containing autologous blood, lidocaine, heparin, antibiotics, glucose 10 % solution and flunixin, the NELP was achieved. The liver was perfused over 7 hours after 48 hours of cold storage (4C°), using Eurocollins solution. During the liver withdrawal in the slaughterhouse 20 minutes were waited to simulate the warm ischemia (WI) time. Histological samples, swab for bacterial grow, blood sample, temperature and pulse oximetry saturation were collected to assess the liver viability and function. These analyses revealed stable metabolism throughout perfusion identifying a cycles 2 hours length, coinciding with recovery of oxygen uptake rates to fresh liver, as described in literature.In summary the preliminary established model of isolated hemoperfused slatherhouse liver reveals the important role of the relation between cold storage and normothermic perfusion. Moreover this preliminary study justifies further investigation of the optimization of the treatment protocols and perfusion media

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Measurements of the Higgs boson production and decay rates and coupling strengths using pp collision data at √S=7 and 8 TeV in the ATLAS experiment

Combined analyses of the Higgs boson production and decay rates as well as its coupling strengths to vector bosons and fermions are presented. The combinations include the results of the analyses of the H -> gamma gamma, ZZ*, WW*, Z gamma, b (b) over bar, tau tau and mu mu decay modes, and the constraints on the associated production with a pair of top quarks and on the off-shell coupling strengths of the Higgs boson. The results are based on the LHC proton-proton collision datasets, with integrated luminosities of up to 4.7 fb(-1) at root s = 7 TeV and 20.3 fb(-1) at root s = 8 TeV, recorded by the ATLAS detector in 2011 and 2012. Combining all production modes and decay channels, the measured signal yield, normalised to the Standard Model expectation, is 1.18(-0.14)(+0.15). The observed Higgs boson production and decay rates are interpreted in a leading-order coupling framework, exploring a wide range of benchmark coupling models both with and without assumptions on the Higgs boson width and on the Standard Model particle content in loop processes. The data are found to be compatible with the Standard Model expectations for a Higgs boson at a mass of 125.36 GeV for all models considered