Репозиторий Университета

© 2020 Elsevier B.V. Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF) are crucial for the peripheral and central nervous system development, respectively, and differential brain and blood levels in Intra Uterine Growth Restriction (IUGR) and prematurity have been found. As reduced growth of brain regions, measured at 30−40 days of postnatal period, has been demonstrated in preterm and IUGR neonates who showed impaired neuro-development at two years of age, in this study, the levels of NGF and BDNF were evaluated in the urine samples of 30−40 day-old subjects who were full-term, preterm and IUGR and showed a normal or an abnormal neuro-development at follow up after two years. Neurotrophins were measured concurrently with volumes of whole brain, thalamus, frontal cortex and cerebellum. Values were then correlated with later neuro-developmental outcome. Biochemical parameters and cerebral volumes were assessed using colorimetric ELISA kits and three-dimensional ultra-sonography (3DUS), respectively. Neuro-development was estimated using the Griffiths-II test. Urinary NGF and brain volumes significantly correlated and were lower in preterm and IUGR subjects characterized by poor neuro-development. No differences were seen in the case of BDNF. The present investigation demonstrates, for the first time, the strong and direct association of NGF with brain growth at the initial phase of the postnatal period and with neuro-developmental outcome in later life. Remarkably, urinary NGF may be suggested as an early prognostic indicator of high long-term risk of motor and cognitive impairment in IUGR and preterm neonates.

© 2020 Elsevier B.V. Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF) are crucial for the peripheral and central nervous system development, respectively, and differential brain and blood levels in Intra Uterine Growth Restriction (IUGR) and prematurity have been found. As reduced growth of brain regions, measured at 30−40 days of postnatal period, has been demonstrated in preterm and IUGR neonates who showed impaired neuro-development at two years of age, in this study, the levels of NGF and BDNF were evaluated in the urine samples of 30−40 day-old subjects who were full-term, preterm and IUGR and showed a normal or an abnormal neuro-development at follow up after two years. Neurotrophins were measured concurrently with volumes of whole brain, thalamus, frontal cortex and cerebellum. Values were then correlated with later neuro-developmental outcome. Biochemical parameters and cerebral volumes were assessed using colorimetric ELISA kits and three-dimensional ultra-sonography (3DUS), respectively. Neuro-development was estimated using the Griffiths-II test. Urinary NGF and brain volumes significantly correlated and were lower in preterm and IUGR subjects characterized by poor neuro-development. No differences were seen in the case of BDNF. The present investigation demonstrates, for the first time, the strong and direct association of NGF with brain growth at the initial phase of the postnatal period and with neuro-developmental outcome in later life. Remarkably, urinary NGF may be suggested as an early prognostic indicator of high long-term risk of motor and cognitive impairment in IUGR and preterm neonates.

BACKGROUND: This retrospective clinical study aims to present results of experience with a novel guided surgery system with a sleeveless, open-frame structure, in which the surgical handpiece (not the drills used for preparation) is guided. METHODS: This study was based on an evaluation of the records of partially edentulous patients who had been treated with a sleeveless open-frame guided surgery system (TWIN-Guide®, 2Ingis, Brussels, Belgium), between January 2015 and December 2017. Inclusion criteria were patients with good systemic/oral health and a minimum follow-up of 1 year. Exclusion criteria were patients who had been treated without a guide, or with a guide with sleeves, patients with systemic/oral diseases and who did not have a follow-up of 1 year. The main outcomes were surgical (fit and stability of the surgical guide, duration of the intervention, implant stability, and any intra-operative or immediate post-operative complication), biologic, and prosthetic. RESULTS: Thirty-eight patients (24 males, 14 females; mean age 56.5 ± 14.0 years) were included in the study. These patients had been treated with 110 implants inserted by means of 40 sleeveless, open-frame guides. With regard to fit and stability, 34 guides were excellent, 4 acceptable, and 2 inadequate for use. The mean duration of the intervention was 23.7 (± 6.7) minutes. Immediately after placement, 2 fixtures were not stable and had to be removed. Two patients experienced pain/swelling after surgery. The 108 surviving implants were restored with 36 single crowns and 32 fixed partial prostheses (24 two-unit and 8 three-unit bridges); these restorations survived until the 1-year follow-up, with a low incidence of biologic and prosthetic complications. CONCLUSIONS: Within the limits of this study, this novel guided surgery system with sleeveless, open frame-structure guides seems to be clinically reliable; further studies on a larger sample of patients are needed to confirm these outcomes.

© 2019 Elsevier Inc. The paper studies an approximate static condensation method for the diffusion problem with discontinuous diffusion coefficients. The method allows for a general polygonal mesh which is unfitted to the material interfaces. Moreover, the interfaces can be discontinuous across the mesh edges as typical for numerical reconstructions using the volume or moment-of-fluid methods. We apply a mimetic finite difference method to solve local diffusion problems and use P1 (mortar) edge elements to couple local problems into the global system. The condensation process and the properties of the resulting algebraic system are discussed. It is demonstrated that the method is second order accurate on smooth solutions and performs well for problems with high contrast in diffusion coefficients. Experiments also show the robustness with respect to position of the material interfaces against the underlying mesh.

© 2018 American Society for Microbiology. All Rights Reserved. Reproduction of RNA viruses is typically error-prone due to the infidelity of their replicative machinery and the usual lack of proofreading mechanisms. The error rates may be close to those that kill the virus. Consequently, populations of RNA viruses are represented by heterogeneous sets of genomes with various levels of fitness. This is especially consequential when viruses encounter various bottlenecks and new infections are initiated by a single or few deviating genomes. Nevertheless, RNA viruses are able to maintain their identity by conservation of major functional elements. This conservatism stems from genetic robustness or mutational tolerance, which is largely due to the functional degeneracy of many protein and RNA elements as well as to negative selection. Another relevant mechanism is the capacity to restore fitness after genetic damages, also based on replicative infidelity. Conversely, error-prone replication is a major tool that ensures viral evolvability. The potential for changes in debilitated genomes is much higher in small populations, because in the absence of stronger competitors low-fit genomes have a choice of various trajectories to wander along fitness landscapes. Thus, low-fit populations are inherently unstable, and it may be said that to run ahead it is useful to stumble. In this report, focusing on picornaviruses and also considering data from other RNA viruses, we review the biological relevance and mechanisms of various alterations of viral RNA genomes as well as pathways and mechanisms of rehabilitation after loss of fitness. The relationships among mutational robustness, resilience, and evolvability of viral RNA genomes are discussed.

© Copyright 2018, Mary Ann Liebert, Inc., publishers 2018. Aim: To compare a program based on intermittent hypoxia-hyperoxia training (IHHT) consisting of breathing hypoxic-hyperoxic gas mixtures while resting to a standard exercise-based rehabilitation program with respect to cardiorespiratory fitness (CRF) in older, comorbid cardiac outpatients. Materials and Methods: Thirty-two cardiac patients with comorbidities were randomly allocated to IHHT and control (CTRL) groups. IHHT completed a 5-week program of exposure to hypoxia-hyperoxia while resting, CTRL completed an 8-week tailored exercise program, and participants in the CTRL were also exposed to sham hypoxia exposure. CRF and relevant hematological biomarkers were measured at baseline and after treatment in both groups. Results: After intervention, CRF in the IHHT group was not significantly different (n = 15, 19.9 ± 6.1 mlO2 minutes-1 kg-1) compared with the CTRL group (n = 14, 20.6 ± 4.9 mlO2 minutes-1 kg-1). CRF in IHHT increased significantly from baseline (6.05 ± 1.6 mlO2 minutes-1 kg-1), while no difference was found in CTRL. Systolic and diastolic blood pressures were not significantly different between groups after treatment. Hemoglobin content was not significantly different between groups. Erythrocytes and reticulocytes did not change pre/post interventions in both experimental groups. Conclusions: IHHT is safe in patients with cardiac conditions and common comorbidities and it might be a suitable option for older patients who cannot exercise. A 5-week IHHT is as effective as an 8-week exercise program in improving CRF, without hematological changes. Further studies are needed to clarify the nonhematological adaptations to short, repeated exposure to normobaric hypoxia-hyperoxia.