Bioengineering Dermo-Epidermal Skin Grafts with Blood and Lymphatic Capillaries

The first bioengineered, autologous, dermo-epidermal skin grafts are presently undergoing clinical trials; hence, it is reasonable to envisage the next clinical step at the forefront of plastic and burn surgery, which is the generation of autologous skin grafts that contain vascular plexuses, preformed in vitro. As the importance of the blood, and particularly the lymphatic vascular system, is increasingly recognized, it is attractive to engineer both human blood and lymphatic vessels in one tissue or organ graft. We show here that functional lymphatic capillaries can be generated using three-dimensional hydrogels. Like normal lymphatics, these capillaries branch, form lumen, and take up fluid in vitro and in vivo after transplantation onto immunocompromised rodents. Formation of lymphatic capillaries could be modulated by both lymphangiogenic and anti-lymphangiogenic stimuli, demonstrating the potential usefulness of this system for in vitro testing. Blood and lymphatic endothelial cells never intermixed during vessel development, nor did blood and lymphatic capillaries anastomose under the described circumstances. After transplantation of the engineered grafts, the human lymphatic capillaries anastomosed to the nude rat's lymphatic plexus and supported fluid drainage. Successful preclinical results suggest that these skin grafts could be applied on patients suffering from severe skin defects

Toolbox Scilab : Detection signal design for failure detection and isolation for linear dynamic systems User's Guide

We show how the Detection Toolbox can be used in Scilab. We present a Toolbox to calculate a filter for failure detection and isolation in dynamic systems. This Toolbox uses Scilab and the LIPSOL library (Linear programming Interior Point SOLvers)

The occurrence of postoperative vertigo after CI

Background. The incidence of postoperative vertigo after cochlear implantation (CI) varies a lot in the literature. The aim of this work was to investigate both subjective complaints of vertigo before and after cochlear implantation and related it to to the preoperative vestibular function, the surgical procedure and to the position of CI at the postoperative neuroradiological study. Methods. Retrospective cohort study of adult CI series operated by the same surgeon (DZ) over the last 3 years. (N= 107). Sixty-six subjects (38 F; 28 M), aged from 21 to 78 years old were included in the study, lasting 83 CI. The outcomes of the pre-operative vestibular assessment were extracted from the database of the Vestibular Disorders Unit of the tertiary referral University Hospital of Milano from 1992 to 2018 (N=557). Post-operative presence/absence of vestibular disorders was analyzed and related to the preoperative vestibular examination and to the flat-panel computed tomography (FPCT) findings. Results: The patients were divided by age and by the presence of vestibular response of the operated ear measured by videoculography, caloric testing and video-impulse test. Sensorial analysis by static posturography was also included. The incidence of postoperative vertigo was higher in patients > 65 years old (36.3% vs 20.4%, p=0.03). Postoperative vertigo did not result related to the surgical procedure. The results are discussed with the review of the literature. Conclusion: Our results confirm the importance of vestibular testing in CI recipients, in order to better counsel the patient on the foreseeable post-operative course and to identify those patients who will need a vestibular rehabilitation

Detection Signal Design for Failure Detection and Isolation For Linear Dynamic System

Projet META2We present a new methodology to calculate a filter that permits failure detection and isolation in a dynamic system. Assuming that the normal and the failed behaviors of a process can be modeled by two linear systems subject to inequality bounded perturbations, a method for on line implementati-on of a detection signal, guaranteeing detection of failure, is presented. To make the failure detectable, the injection of the test signal that improves the detectability property of failure in the dynamic process is proposed which achieves detectability on line. All the operations needed for our method are implemented by using large linear optimization problem. Examples are shown

Implementation of Lipsol in Scilab

Projet META2We show how the LIPSOL library (Linear programming Interior-Point SOLvers) can be used in Scilab. To do this, fast Scilab-Fortran interfaces for sparse Cholesky decomposition have been developed. All other calculations are made using Scilab functions, which take into account sparsity for storing and factorizing the matrices. We make use of structural matrices algorithms from Metanet (Scilab toolbox for graphs and networks computations), in particular the Dulmage Mendelsohn algorithm

Solving Large Linear Optimization Problems with Scilab : Application to Multicommodity Problems

Projet META2We show the incorporation into the Scilab environment of the codes Lipsol, Hopdm and Lp_solve. We describe their use from Scilab and give a comparison of some results obtained. Applications for multicommodity problems are shown, which are solved in a user-friendly way using Metanet for the data introduction and visualization of the results

Comparison of intrascalar location of straight vs perimodiolar electrode array by flat-panel computerized tomography

Introduction, One of the fields of technological advancement in cochlear implants (CI) pursued by all manufacturers is the development of less traumatic electrodes that can conform to the anatomy of the cochlea, and possibly enhance the outcomes. Recently, a slim precurved perimodiolar electrode with an insertion guidance sleeve has been designed in order to facilitate the insertion and to avoid the inter-scalar dislodgement that frequently occurs at the first basal turn. Aim of this study was to evaluate the intracochlear position of different Nucleus electrode arrays in aduld and pediatric CI recipients by means of flat-panel volume computerized tomography (FPCT). Methods, Fifty-six CI recipients (37 females, 19 males), 1 to 80 years of age, operated by the same surgeon with the same technique, were included. All underwent FPCT with a C-arm angiographic system including a digital flat panel detector 30 x 40 cm, with a source-to-image-receptor distance of 120cm. The imaging assessment was performed the day after surgery in all cases. Sequential and simultaneous CI were included and a total of 68 ears have been analyzed. The primary objective was to identify the scalar location of the array (completely in scala tympani vs. partially dislodged in scala vestibuli) and the site of dislocation. Secondarily, we measured the medial-lateral position within the scala, the insertion depth (mm and angles). The FPCT findings were also contrasted with the type of cochleostomy (round window (RW), extended RW, promontorial) and with the residual hearing preservation. Results, Fifty-nine ears were implanted with a perimodiolar electrode, either Nucleus CI532 (n=45) or a CI412 / CI512 Contour Advance (n=14), while 9 received a straight one (Nucleus CI422/CI522). A RW approach was performed more frequently (41 out of 45 = 91.1 %) with CI532 than with the other arrays (10 out of 23 = 43.5%). Inferior and/or anterior cochleostomy were never performed. The CI532 showed the most consistent and reliable intrascalar position, close to the modiolus and in the scala tympani. Scala vestibuli dislodgement was observed in (14.3%) of the Contour Advance electrodes and in (6.7%) of the CI532. Pre-operative residual hearing was preserved within 10 dB HL in 62% of the cases. Conclusions: the CI532 electrode array achieved the most consistent and reliable perimodiolar location by FPCT; in our small series it appeared to be dislodged in the scala tympani in the minority of cases