Human and bovine respiratory syncytial virus vaccine research and development

Human (HRSV) and bovine (BRSV) respiratory syncytial viruses (RSV) are two closely related viruses, which are the most important causative agents of respiratory tract infections of young children and calves, respectively. BRSV vaccines have been available for nearly 2 decades. They probably have reduced the prevalence of RSV infection but their efficacy needs improvement. In contrast, despite decades of research, there is no currently licensed vaccine for the prevention of HRSV disease. Development of a HRSV vaccine for infants has been hindered by the lack of a relevant animal model that develops disease, the need to immunize immunologically immature young infants, the difficulty for live vaccines to find the right balance between attenuation and immunogenicity, and the risk of vaccine-associated disease. During the past 15 years, intensive research into a HRSV vaccine has yielded vaccine candidates, which have been evaluated in animal models and, for some of them, in clinical trials in humans. Recent formulations have focused on subunit vaccines with specific CD4+ Th-1 immune response-activating adjuvants and on genetically engineered live attenuated vaccines. It is likely that different HRSV vaccines and/or combinations of vaccines used sequentially will be needed for the various populations at risk. This review discusses the recent advances in RSV vaccine development

In vivo evidence for quasispecies distributions in the bovine respiratory syncytial virus genome

We analyzed the genetic evolution of bovine respiratory syncytial virus (BRSV) isolate W2-00131, from its isolation in bovine turbinate (BT) cells to its inoculation in calves. Results showed that the BRSV genomic region encoding the highly variable glycoprotein G remains genetically stable after virus isolation and over 10 serial infections in BT cells, as well as following experimental inoculation in calves. This remarkable genetic stability led us to examine the mutant spectrum of several populations derived from this field isolate. Sequence analysis of molecular clones revealed an important genetic heterogeneity in G coding region of each population, with mutation frequencies ranging from 6.8 to 10.1 10-4 substitutions/nucleotide. The non-synonymous mutations of the mutant spectrum mapped preferentially within the two variable antigenic regions of the ectodomain or close to the highly conserved domain. These results suggest that RSV populations may evolve as complex and dynamic mutant swarms, despite apparent genetic stability

Advanced survival models for risk-factor analysis in scrapie

Because of the confounding effects of long incubation duration and flock management, accurate epidemiological studies of scrapie outbreaks are difficult to carry out. In this study, 641 Manech red-faced sheep from six scrapie-affected field flocks in Pyrénées Atlantiques, France, were monitored for clinical scrapie over a 6–9 year period. Over this period, 170 scrapie clinical cases were recorded and half of the culled animals were submitted for post-mortem transmissible spongiform encephalopathy diagnosis to assess their infectious status. Collected data were analysed using a ‘mixture cure model’ approach, which allowed for the discriminating effect of PrP genotype and flock origin on incidence and incubation period. Simulations were performed to evaluate the applicability of such a statistical model to the collected data. As expected, ARR heterozygote sheep were less at risk of becoming infected than ARQ/ARQ individuals and had a greater age at clinical onset. Conversely, when compared with ARQ/ARQ, the VRQ haplotype was associated with an increased infection risk, but not a shorter incubation period. Considering the flock effect, we observed that a high incidence rate was not associated with shorter incubation periods and that the incubation period could be significantly different in flocks harbouring similar infection risks. These results strongly support the conclusion that other parameters, such as the nature of the agent or flock management, could interfere with epidemiological dynamics of the infection in scrapie-affected flocks

Methylated DNA recognition during the reversal of epigenetic silencing is regulated by cysteine and cerine residues in the Epstein-Barr Virus lytic switch protein

Epstein-Barr virus (EBV) causes infectious mononucleosis and is associated with various malignancies, including Burkitt's lymphoma and nasopharyngeal carcinoma. Like all herpesviruses, the EBV life cycle alternates between latency and lytic replication. During latency, the viral genome is largely silenced by host-driven methylation of CpG motifs and, in the switch to the lytic cycle, this epigenetic silencing is overturned. A key event is the activation of the viral BRLF1 gene by the immediate-early protein Zta. Zta is a bZIP transcription factor that preferentially binds to specific response elements (ZREs) in the BRLF1 promoter (Rp) when these elements are methylated. Zta's ability to trigger lytic cycle activation is severely compromised when a cysteine residue in its bZIP domain is mutated to serine (C189S), but the molecular basis for this effect is unknown. Here we show that the C189S mutant is defective for activating Rp in a Burkitt's lymphoma cell line. The mutant is compromised both in vitro and in vivo for binding two methylated ZREs in Rp (ZRE2 and ZRE3), although the effect is striking only for ZRE3. Molecular modeling of Zta bound to methylated ZRE3, together with biochemical data, indicate that C189 directly contacts one of the two methyl cytosines within a specific CpG motif. The motif's second methyl cytosine (on the complementary DNA strand) is predicted to contact S186, a residue known to regulate methyl-ZRE recognition. Our results suggest that C189 regulates the enhanced interaction of Zta with methylated DNA in overturning the epigenetic control of viral latency. As C189 is conserved in many bZIP proteins, the selectivity of Zta for methylated DNA may be a paradigm for a more general phenomenon

Functional interaction between Epstein-Barr virus replication protein Zta and host DNA damage response protein 53BP1

Epstein-Barr virus (EBV; human herpesvirus 4) poses major clinical problems worldwide. Following primary infection, EBV enters a form of long-lived latency in B lymphocytes, expressing few viral genes, and it persists for the lifetime of the host with sporadic bursts of viral replication. The switch between latency and replication is governed by the action of a multifunctional viral protein Zta (also called BZLF1, ZEBRA, and Z). Using a global proteomic approach, we identified a host DNA damage repair protein that specifically interacts with Zta: 53BP1. 53BP1 is intimately connected with the ATM signal transduction pathway, which is activated during EBV replication. The interaction of 53BP1 with Zta requires the C-terminal ends of both proteins. A series of Zta mutants that show a wild-type ability to perform basic functions of Zta, such as dimer formation, interaction with DNA, and the transactivation of viral genes, were shown to have lost the ability to induce the viral lytic cycle. Each of these mutants also is compromised in the C-terminal region for interaction with 53BP1. In addition, the knockdown of 53BP1 expression reduced viral replication, suggesting that the association between Zta and 53BP1 is involved in the viral replication cycle

Lawn Mower Lift

Our team of engineers were given the task of coming up with a design project and designing the system, creating calculations, and brainstorming ideas. We set out to design a riding lawn mower lift. The purpose of this design was to assist in general maintenance like replacing blades, oil changes, etc. To accomplish this task, our team started to brainstorm ideas and make sketches to look at all the options. We then did research and looked at different size lawn mowers and looked at the specifications. This helped our team to be able to design the size of platform needed to accommodate the size of the tractors. Then, calculations were performed to see the lifting power needed for the mower. Once all of the decisions and calculations were made, we designed the 3D model of our design. As a result, our team of engineers have produced a lawn mower lift concept that is both functional and user friendly. This will help the customer have a more functional and more ergonomically friendly design to work on any repairs. We designed the lift to have the front end lift up significantly more than the back end so the user can change blades on a mower easier. Also the user could make the front and back end level to get under the vehicle to change oil or perform general maintenance with more room to work with under the vehicle. Once the concept was developed, we expanded our capabilities to other small motorized vehicles with four wheels, like four-wheelers, go-carts, or side-by-sides

Le transfert de films (vers une intégration hétérogène des micro et nanosystèmes)

Une technologie d élaboration de micro et nanosystèmes idéale devrait permettre l intégration de différents matériaux (magnétiques, piézoélectriques, polymères, etc.) ou structures (composants optiques, mécaniques, optoélectroniques, etc.) de nature fortement hétérogène dans le but d obtenir des systèmes multifonctionnels complexes éventuellement encapsulés. Un moyen de contourner les différents problèmes d incompatibilité, liés aux mélanges des technologies de fabrication, est de transférer les différents films de matériaux ou composants d un substrat donneur, sur lequel ils ont été préalablement élaborés, vers le substrat comportant le système visé Dans cette optique, un procédé de transfert de film à basse température a été développé. Ce procédé repose sur le contrôle de l adhésion d un film mince de nickel préformé, à partir d un substrat dit donneur , sur une couche à adhésion contrôlée de nature carbonée ou fluorocarbonée. La libération mécanique du film, sur un substrat dit cible , est assurée par une soudure adhésive via des cordons de scellement en BCB. Grâce à sa facilité de mise en œuvre et aux faibles températures requises pour le scellement des substrats, ce procédé a permis de transférer des microstructures en nickel sur des substrats de silicium, de verre ainsi que sur des substrats Kapton souples. L emploi d une soudure BCB assure l isolation thermique et électrique des microstructures sur le substrat cible. La versatilité du procédé a été prouvée par l empilement de microstructures suspendues et par le transfert de divers matériaux. Ce procédé est très prometteur pour de nombreuses applications et apporte de nouvelles perspectives quant à l intégration hétérogène 3D de micro et nanosystèmes.Nowadays, micro and nano systems fabrication technologies should allow the integration of any passive or active materials (magnetic, piezoelectric, polymers, etc.) in various forms (films, micro/nanostructures, etc.) to build and/or package highly integrated multi-functional systems. A generic technology able to solve incompatibility issues related to the mixing of different technologies is pattern or device transfer by wafer bonding from a donor wafer to the target substrate. Ideally, such a process should be versatile, low cost, selective and over all should involve minimum interaction and processing steps on the target wafer. From this perspective, a low cost and low temperature MEMS transfer process has been developed. The process is based on adhesion control of molded electroplated Ni microstructures on the donor wafer by using plasma deposited fluorocarbon films and sputtered carbon films (for high temperature materials). Adhesive bonding of the microstructures on the target wafer using BCB sealing enables mechanical tearing off from the donor wafer. This proposed process has allowed us to realize various Ni patterns on Si, Pyrex glass wafers and Kapton foils. Furthermore, BCB sealing leads to freestanding microstructures which are thermally and electrically isolated from the target substrate. Thanks to multiple transfers, Ni stacked microstructures have been achieved. The transfer of various materials has been demonstrated for simple and complex structures. This transfer process is very promising for numerous applications and brings new perspectives towards 3D microfabrication and heterogeneous integration of MEMS/NEMS.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Clinical, electroretinographic and histomorphometric evaluation of the retina in sheep with natural scrapie

Background: The retina is part of the diencephalon in a peripheral location and may be involved in prion diseases. Retinal function and structural changes were assessed in naturally scrapie-affected red face Manech ewes presenting the classical signs of the disease, and clinically healthy age-matched subjects for controls. Ophthalmic examination was done prior to electroretinography (ERG), which was carried out under conditions that allowed photopic and scotopic activities to be assessed. Histomorphometry of the inner and outer retinal layers was performed post-mortem, and retinas were also examined for evidence of abnormal prion protein (PrPSc) accumulation and glial fibrillary acidic protein (GFAP) upregulation as a marker of gliosis. Scrapie status was determined by examination of brain tissue Results: Ocular reflexes and ophthalmoscopy did not reveal any difference between scrapie affected and control animals. Although the light-and dark-adapted ERG responses of both rod-and cone-mediated functions had a similar waveform in scrapie-affected and control sheep, a significant reduction in the amplitude of the ERG a-and b-waves was observed in affected animals compared to controls. These functional alterations were correlated with a substantial loss of cells in the outer nuclear layer (ONL), lengthening and disorganization in photoreceptor segments, and substantial reduction in cellularity and thickness of the inner nuclear layer (INL). The degenerative changes in the INL and ONL were most marked in the central and paracentral areas of the scrapie retinas, and were accompanied in all scrapie retinas by PrPSc deposition in the ganglion cell and synaptic layers. GFAP immunoreactivity was mainly increased in the ganglion cell and inner plexiform layers. Conclusions: No appreciable fundoscopic changes were observed in the scrapie-affected ewes although reproducible changes in retinal function as measured by ERG were observed in these animals. The alterations in the receptoral and post-receptoral pathways corresponded to the degenerative lesions observed in the ONL and INL of the scrapie retinas. The retinal degeneration was associated with prion protein infectivity which presumably spread via the optic nerve

Dermoglandular Rotation Flaps for Breast-Conserving Therapy: Aesthetic Results, Patient Satisfaction, and Morbidity in Comparison to Standard Segmentectomy

We compared a dermoglandular rotation flap (DGR) in the upper inner, lower inner, and upper outer quadrant regarding similar aesthetic results, patient satisfaction, and comfort after breast-conserving therapy with standard segmentectomy (SE). Between 2003 and 2011, 69 patients were treated with breast-conserving surgery using DGR for cancers with high tumor-to-breast volume ratios or skin resection in the three above mentioned quadrants; 161 patients with tumors in the same quadrants were treated with SE. The outcome of the procedures was assessed at least 7 months after completed radiation therapy using a patient and breast surgeon questionnaire and the BCCT.core software. Symmetry, visibility of the scars, the position of the nipple-areola complex, and the appearance of the treated breast were each assessed on a scale from 1 to 4 by an expert panel and by the patients. Univariate and multivariate analysis were used to evaluate the relationship between patient-, tumor-, and treatment-dependent factors and patient satisfaction. 94.2% of the patients with rotation flaps and 83.5% of the patients with lumpectomy were very satisfied with the cosmetic appearance of their breast. Younger patient age was significantly associated with a lower degree of satisfaction. DGR provides good cosmetic results compared with SE and shows high patient satisfaction despite longer scarring and higher median resection volume