Genetic variability of hepatitis C virus before and after combined therapy of interferon plus ribavirin

We present an analysis of the selective forces acting on two hepatitis C virus genome regions previously postulated to be involved in the viral response to combined antiviral therapy. One includes the three hypervariable regions in the envelope E2 glycoprotein, and the other encompasses the PKR binding domain and the V3 domain in the NS5A region. We used a cohort of 22 non-responder patients to combined therapy (interferon alpha-2a plus ribavirin) for which samples were obtained before initiation of therapy and after 6 or/and 12 months of treatment. A range of 25-100 clones per patient, genome region and time sample were sequenced. These were used to detect general patterns of adaptation, to identify particular adaptation mechanisms and to analyze the patterns of evolutionary change in both genome regions. These analyses failed to detect a common adaptive mechanism for the lack of response to antiviral treatment in these patients. On the contrary, a wide range of situations were observed, from patients showing no positively selected sites to others with many, and with completely different topologies in the reconstructed phylogenetic trees. Altogether, these results suggest that viral strategies to evade selection pressure from the immune system and antiviral therapies do not result from a single mechanism and they are likely based on a range of different alternatives, in which several different changes, or their combination, along the HCV genome confer viruses the ability to overcome strong selective [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]

Positional variations among heterogeneous nucleosome maps give dynamical information on chromatin

Although nucleosome remodeling is essential to transcriptional regulation in eukaryotes, little is known about its genome-wide behavior. Since a number of nucleosome positioning maps in vivo have been recently determined, we examined if their comparisons might be used for obtaining a genome-wide profile of nucleosome remodeling. Using seven yeast maps, the local variability of nucleosomes, measured by the entropy, was significantly higher in a set of reported unstable nucleosomes. The binding sites of four transcription factors, known as the remodeling factors, were distinctively high both in entropy and linker ratio, whereas those of Yhp1, their potential inhibitor, showed the lowest values in both of them. Taken together, our map shows the general information of nucleosome dynamics reasonably well. The “nucleosome dynamics” map provides the new significant correlation with the degree of expression variety instead of their intensity. Furthermore, the associations with gene function and histone modification were also discussed here

FCS-MPC upravljačka strategija novim trorazinskim izmjenjivačem otpornim na kvarove

In order to meet the high reliability of aviation inverters, the paper established a new three-level inverter which can increase the reliability in safety-critical applications, what\u27s more, the new topology adding assistant leg to control neutral-point voltage independently. On the basis of the new topology, a mixed logic dynamic (MLD) model was established for the new inverter circuits, and takes finite control set model predictive control (FCS-MPC) for the new inverter. The method takes a discrete-time model of inverter to predict the future value of the all possible voltage vectors generated by the inverter. The vector which minimizes objective function in finite control set is selected as the control of inverter, the objective function used in this work evaluates the voltage error and the switch frequency at the next sampling time. The paper explicitly researched the solving algorithm and realization procedure of the new inverter circuit, its feasibility and validity is verified by the experiment.Za postizanje visokog stupnja pouzdanosti avijacijskih izmjenjivača, u radu je postavljena nova topologija trorazinskog izmjenjivača za primjene u sigurnosno kritičnim sustavima koja ima dodatnu pomoćnu granu za nezavisno upravljanje naponom neutralne točke. Zasnivajući se na ovoj novoj topologiji, dinamički model s mješovitom logikom (MLD) postavljen je za električne krugove novog ispravljača koji za upravljanje pretvaračem koriste konačni skup upravljačkih signala dobivenih modelskog prediktivnog upravljanja (FCS-MPC). Metoda koristi vremenski diskretni model izmjenjivača za predviđanje budućih vrijednosti svih mogućih vektora napona koje generira izmjenjivač. Za upravljanje pretvaračem koristi se upravljački vektor iz konačnog skupa upravljačkih signala dobiven minimiziranjem funkcije cilja koja u obzir uzima grešku napona i frekvenciju sklapanja u sljedećem koraku diskretizacije. U radu je izravno razvijen algoritam za rješavanje problema i procedura za realizaciju nove topologije izmjenjivača, a izvedivost i validnost provjereni su eksperimentalno

In Vivo Imaging Reveals Distinct Inflammatory Activity of CNS Microglia versus PNS Macrophages in a Mouse Model for ALS

Mutations in the enzyme superoxide dismutase-1 (SOD1) cause hereditary variants of the fatal motor neuronal disease Amyotrophic lateral sclerosis (ALS). Pathophysiology of the disease is non-cell-autonomous: neurotoxicity is derived not only from mutant motor neurons but also from mutant neighbouring non-neuronal cells. In vivo imaging by two-photon laser-scanning microscopy was used to compare the role of microglia/macrophage-related neuroinflammation in the CNS and PNS using ALS-linked transgenic SOD1G93A mice. These mice contained labeled projection neurons and labeled microglia/macrophages. In the affected lateral spinal cord (in contrast to non-affected dorsal columns), different phases of microglia-mediated inflammation were observed: highly reactive microglial cells in preclinical stages (in 60-day-old mice the reaction to axonal transection was ∼180% of control) and morphologically transformed microglia that have lost their function of tissue surveillance and injury-directed response in clinical stages (reaction to axonal transection was lower than 50% of control). Furthermore, unlike CNS microglia, macrophages of the PNS lack any substantial morphological reaction while preclinical degeneration of peripheral motor axons and neuromuscular junctions was observed. We present in vivo evidence for a different inflammatory activity of microglia and macrophages: an aberrant neuroinflammatory response of microglia in the CNS and an apparently mainly neurodegenerative process in the PNS

COX-2, CB2 and P2X7-immunoreactivities are increased in activated microglial cells/macrophages of multiple sclerosis and amyotrophic lateral sclerosis spinal cord

BACKGROUND: While multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) are primarily inflammatory and degenerative disorders respectively, there is increasing evidence for shared cellular mechanisms that may affect disease progression, particularly glial responses. Cyclooxygenase 2 (COX-2) inhibition prolongs survival and cannabinoids ameliorate progression of clinical disease in animal models of ALS and MS respectively, but the mechanism is uncertain. Therefore, three key molecules known to be expressed in activated microglial cells/macrophages, COX-2, CB2 and P2X7, which plays a role in inflammatory cascades, were studied in MS and ALS post-mortem human spinal cord. METHODS: Frozen human post mortem spinal cord specimens, controls (n = 12), ALS (n = 9) and MS (n = 19), were available for study by immunocytochemistry and Western blotting, using specific antibodies to COX-2, CB2 and P2X7, and markers of microglial cells/macrophages (CD 68, ferritin). In addition, autoradiography for peripheral benzodiazepine binding sites was performed on some spinal cord sections using [3H] (R)-PK11195, a marker of activated microglial cells/macrophages. Results of immunostaining and Western blotting were quantified by computerized image and optical density analysis respectively. RESULTS: In control spinal cord, few small microglial cells/macrophages-like COX-2-immunoreactive cells, mostly bipolar with short processes, were scattered throughout the tissue, whilst MS and ALS specimens had significantly greater density of such cells with longer processes in affected regions, by image analysis. Inflammatory cell marker CD68-immunoreactivity, [3H] (R)-PK11195 autoradiography, and double-staining against ferritin confirmed increased production of COX-2 by activated microglial cells/macrophages. An expected 70-kDa band was seen by Western blotting which was significantly increased in MS spinal cord. There was good correlation between the COX-2 immunostaining and optical density of the COX-2 70-kDa band in the MS group (r = 0.89, P = 0.0011, n = 10). MS and ALS specimens also had significantly greater density of P2X7 and CB2-immunoreactive microglial cells/macrophages in affected regions. CONCLUSION: It is hypothesized that the known increase of lesion-associated extracellular ATP contributes via P2X7 activation to release IL-1 beta which in turn induces COX-2 and downstream pathogenic mediators. Selective CNS-penetrant COX-2 and P2X7 inhibitors and CB2 specific agonists deserve evaluation in the progression of MS and ALS

Load partitioning between ferrite/martensite and dispersed nanoparticles of a 9Cr ferritic/martensitic (F/M) ODS steel at high temperatures

In this study, a high-energy synchrotron radiation X-ray technique was used to investigate the tensile deformation processes of a 9Cr-ODS ferritic/martensitic (F/M) steel at different temperatures. Two minor phases within the 9Cr-ODS F/M steel matrix were identified as Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> and TiN by the high-energy X-ray diffraction, and confirmed by the analysis using energy dispersive X-ray spectroscopy (EDS) of scanning transmission electron microscope (STEM). The lattice strains of the matrix and particles were measured through the entire tensile deformation process. During the tensile tests, the lattice strains of the ferrite/martensite and the particles (TiN and Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf>) showed a strong temperature dependence, decreasing with increasing temperature. Analysis of the internal stress at three temperatures showed that the load partitioning between the ferrite/martensite and the particles (TiN and Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf>) was initiated during sample yielding and reached to a peak during sample necking. At three studied temperatures, the internal stress of minor phases (Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> and TiN) was about 2 times that of F/M matrix at yielding position, while the internal stress of Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> and TiN reached about 4.5-6 times and 3-3.5 times that of the F/M matrix at necking position, respectively. It indicates that the strengthening of the matrix is due to minor phases (Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> and TiN), especially Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> particles. Although the internal stresses of all phases decreased with increasing temperature from RT to 600°C, the ratio of internal stresses of each phase at necking position stayed in a stable range (internal stresses of Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> and TiN were about 4.5-6 times and 3-3.5 times of that of F/M matrix, respectively). The difference between internal stress of the F/M matrix and the applied stress at 600°C is slightly lower than those at RT and 300°C, indicating that the nanoparticles still have good strengthening effect at 600°C. © 2015 Elsevier B.V