Academic literature on the topic 'Viral variants'
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Journal articles on the topic "Viral variants"
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Lewicki, Hanna, Antoinette Tishon, Persephone Borrow, et al. "CTL Escape Viral Variants." Virology 210, no. 1 (1995): 29–40. http://dx.doi.org/10.1006/viro.1995.1314.
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Lewicki, Hanna A., Mathias G. Von Herrath, Claire F. Evans, J. Lindsay Whitton, and Michael B. A. Oldstone. "CTL Escape Viral Variants." Virology 211, no. 2 (1995): 443–50. http://dx.doi.org/10.1006/viro.1995.1426.
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Welsch, Christoph, Sabine Schweizer, Tetsuro Shimakami, et al. "Ketoamide Resistance and Hepatitis C Virus Fitness in Val55 Variants of the NS3 Serine Protease." Antimicrobial Agents and Chemotherapy 56, no. 4 (2012): 1907–15. http://dx.doi.org/10.1128/aac.05184-11.
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ABSTRACTDrug-resistant viral variants are a major issue in the use of direct-acting antiviral agents in chronic hepatitis C. Ketoamides are potent inhibitors of the NS3 protease, with V55A identified as mutation associated with resistance to boceprevir. Underlying molecular mechanisms are only partially understood. We applied a comprehensive sequence analysis to characterize the natural variability at Val55 within dominant worldwide patient strains. A residue-interaction network and molecular dynamics simulation were applied to identify mechanisms for ketoamide resistance and viral fitness in Val55 variants. An infectious H77S.3 cell culture system was used for variant phenotype characterization. We measured antiviral 50% effective concentration (EC50) and fold changes, as well as RNA replication and infectious virus yields from viral RNAs containing variants. Val55 was found highly conserved throughout all hepatitis C virus (HCV) genotypes. The conservative V55A and V55I variants were identified from HCV genotype 1a strains with no variants in genotype 1b. Topology measures from a residue-interaction network of the protease structure suggest a potential Val55 key role for modulation of molecular changes in the protease ligand-binding site. Molecular dynamics showed variants with constricted binding pockets and a loss of H-bonded interactions upon boceprevir binding to the variant proteases. These effects might explain low-level boceprevir resistance in the V55A variant, as well as the Val55 variant, reduced RNA replication capacity. Higher structural flexibility was found in the wild-type protease, whereas variants showed lower flexibility. Reduced structural flexibility could impact the Val55 variant's ability to adapt for NS3 domain-domain interaction and might explain the virus yield drop observed in variant strains.
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Skums, Pavel, Leonid Bunimovich, and Yury Khudyakov. "Antigenic cooperation among intrahost HCV variants organized into a complex network of cross-immunoreactivity." Proceedings of the National Academy of Sciences 112, no. 21 (2015): 6653–58. http://dx.doi.org/10.1073/pnas.1422942112.
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Hepatitis C virus (HCV) has the propensity to cause chronic infection. Continuous immune escape has been proposed as a mechanism of intrahost viral evolution contributing to HCV persistence. Although the pronounced genetic diversity of intrahost HCV populations supports this hypothesis, recent observations of long-term persistence of individual HCV variants, negative selection increase, and complex dynamics of viral subpopulations during infection as well as broad cross-immunoreactivity (CR) among variants are inconsistent with the immune-escape hypothesis. Here, we present a mathematical model of intrahost viral population dynamics under the condition of a complex CR network (CRN) of viral variants and examine the contribution of CR to establishing persistent HCV infection. The model suggests a mechanism of viral adaptation by antigenic cooperation (AC), with immune responses against one variant protecting other variants. AC reduces the capacity of the host’s immune system to neutralize certain viral variants. CRN structure determines specific roles for each viral variant in host adaptation, with variants eliciting broad-CR antibodies facilitating persistence of other variants immunoreacting with these antibodies. The proposed mechanism is supported by empirical observations of intrahost HCV evolution. Interference with AC is a potential strategy for interruption and prevention of chronic HCV infection.
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Bernasconi, Anna, Andrea Gulino, Tommaso Alfonsi, et al. "VirusViz: comparative analysis and effective visualization of viral nucleotide and amino acid variants." Nucleic Acids Research 49, no. 15 (2021): e90-e90. http://dx.doi.org/10.1093/nar/gkab478.
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Abstract Variant visualization plays an important role in supporting the viral evolution analysis, extremely valuable during the COVID-19 pandemic. VirusViz is a web-based application for comparing variants of selected viral populations and their sub-populations; it is primarily focused on SARS-CoV-2 variants, although the tool also supports other viral species (SARS-CoV, MERS-CoV, Dengue, Ebola). As input, VirusViz imports results of queries extracting variants and metadata from the large database ViruSurf, which integrates information about most SARS-CoV-2 sequences publicly deposited worldwide. Moreover, VirusViz accepts sequences of new viral populations as multi-FASTA files plus corresponding metadata in CSV format; a bioinformatic pipeline builds a suitable input for VirusViz by extracting the nucleotide and amino acid variants. Pages of VirusViz provide metadata summarization, variant descriptions, and variant visualization with rich options for zooming, highlighting variants or regions of interest, and switching from nucleotides to amino acids; sequences can be grouped, groups can be comparatively analyzed. For SARS-CoV-2, we manually collect mutations with known or predicted levels of severity/virulence, as indicated in linked research articles; such critical mutations are reported when observed in sequences. The system includes light-weight project management for downloading, resuming, and merging data analysis sessions. VirusViz is freely available at http://gmql.eu/virusviz/.
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Del Prete, Gregory Q., Haesun Park, Christine M. Fennessey, et al. "Molecularly Tagged Simian Immunodeficiency Virus SIVmac239 Synthetic Swarm for Tracking Independent Infection Events." Journal of Virology 88, no. 14 (2014): 8077–90. http://dx.doi.org/10.1128/jvi.01026-14.
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ABSTRACTFollowing mucosal human immunodeficiency virus type 1 transmission, systemic infection is established by one or only a few viral variants. Modeling single-variant, mucosal transmission in nonhuman primates using limiting-dose inoculations with a diverse simian immunodeficiency virus isolate stock may increase variability between animals since individual variants within the stock may have substantial functional differences. To decrease variability between animals while retaining the ability to enumerate transmitted/founder variants by sequence analysis, we modified the SIVmac239 clone to generate 10 unique clones that differ by two or three synonymous mutations (molecular tags). Transfection- and infection-derived virus stocks containing all 10 variants showed limited phenotypic differences in 9 of the 10 clones. Twenty-nine rhesus macaques were challenged intrarectally or intravenously with either a single dose or repeated, limiting doses of either stock. The proportion of each variant within each inoculum and in plasma from infected animals was determined by using a novel real-time single-genome amplification assay. Each animal was infected with one to five variants, the number correlating with the dose. Longitudinal sequence analysis revealed that the molecular tags are highly stable with no reversion to the parental sequence detected in >2 years of follow-up. Overall, the viral stocks are functional and mucosally transmissible and the number of variants is conveniently discernible by sequence analysis of a small amplicon. This approach should be useful for tracking individual infection events in preclinical vaccine evaluations, long-term viral reservoir establishment/clearance research, and transmission/early-event studies.IMPORTANCEHuman immunodeficiency virus type 1 transmission is established by one or only a few viral variants. Modeling of limited variant transmission in nonhuman primates with a diverse simian immunodeficiency virus isolate stock may increase the variability between animals because of functional differences in the individual variants within the stock. To decrease such variability while retaining the ability to distinguish and enumerate transmitted/founder variants by sequence analysis, we generated a viral stock with 10 sequence-identifiable but otherwise genetically identical variants. This virus was characterizedin vitroandin vivoand shown to allow discrimination of distinct transmission events. This approach provides a novel nonhuman primate challenge system for the study of viral transmission, evaluation of vaccines and other prevention approaches, and characterization of viral reservoirs and strategies to target them.
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Price, Graeme E., Lei Huang, Rong Ou, Menghua Zhang, and Demetrius Moskophidis. "Perforin and Fas Cytolytic Pathways Coordinately Shape the Selection and Diversity of CD8+-T-Cell Escape Variants of Influenza Virus." Journal of Virology 79, no. 13 (2005): 8545–59. http://dx.doi.org/10.1128/jvi.79.13.8545-8559.2005.
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ABSTRACT Antigenic variation is a viral strategy exploited to promote survival in the face of the host immune response and represents a major challenge for efficient vaccine development. Influenza viruses are pathogens with high transmissibility and mutation rates, enabling viral escape from immunity induced by prior infection or vaccination. Intense selection from neutralizing antibody drives antigenic changes in the surface glycoproteins, resulting in emergence of new strains able to reinfect hosts immune to previously circulating viruses. CD8+ cytotoxic T cells (CTLs) also provide protective immunity from influenza virus infection and may contribute to the antigenic evolution of influenza viruses. Utilizing mice transgenic for an influenza virus NP366-374 peptide-specific T-cell receptor, we demonstrated that the respiratory tract is a suitable site for generation of escape variants of influenza virus selected by CTL in vivo. In this report the contributions of the perforin and Fas pathways utilized by influenza virus-specific CTLs in viral clearance and selection of CTL escape variants have been evaluated. While transgenic CTLs deficient in either perforin- or Fas-mediated pathways are efficient in initial pulmonary viral control, variant virus emergence was observed in all the mice studied, although the spectrum of viral CTL escape variants selected varied profoundly. Thus, a less-restricted repertoire of escape variants was observed in mice with an intact perforin cytotoxic pathway compared with a limited variant diversity in perforin pathway-deficient mice, although maximal variant diversity was observed in mice having both Fas and perforin pathways intact. We conclude that selection of viral CTL escape variants reflects coordinate action between the tightly controlled perforin/granzyme pathway and the more promiscuous Fas/FasL pathway.
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Chaqroun, Ahlam, Cédric Hartard, and Evelyne Schvoerer. "Anti-SARS-CoV-2 Vaccines and Monoclonal Antibodies Facing Viral Variants." Viruses 13, no. 6 (2021): 1171. http://dx.doi.org/10.3390/v13061171.
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is genetically variable, allowing it to adapt to various hosts including humans. Indeed, SARS-CoV-2 has accumulated around two mutations per genome each month. The first relevant event in this context was the occurrence of the mutant D614G in the Spike gene. Moreover, several variants have emerged, including the well-characterized 20I/501Y.V1, 20H/501Y.V2, and 20J/501Y.V3 strains, in addition to those that have been detected within clusters, such as 19B/501Y or 20C/655Y in France. Mutants have also emerged in animals, including a variant transmitted to humans, namely, the Mink variant detected in Denmark. The emergence of these variants has affected the transmissibility of the virus (for example, 20I/501Y.V1, which was up to 82% more transmissible than other preexisting variants), its severity, and its ability to escape natural, adaptive, vaccine, and therapeutic immunity. In this respect, we review the literature on variants that have currently emerged, and their effect on vaccines and therapies, and, in particular, monoclonal antibodies (mAbs). The emergence of SARS-CoV-2 variants must be examined to allow effective preventive and curative control strategies to be developed.
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Greenier, Jennifer L., Christopher J. Miller, Ding Lu, et al. "Route of Simian Immunodeficiency Virus Inoculation Determines the Complexity but Not the Identity of Viral Variant Populations That Infect Rhesus Macaques." Journal of Virology 75, no. 8 (2001): 3753–65. http://dx.doi.org/10.1128/jvi.75.8.3753-3765.2001.
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ABSTRACT A better understanding of the host and viral factors associated with human immunodeficiency virus (HIV) transmission is essential to developing effective strategies to curb the global HIV epidemic. Here we used the rhesus macaque-simian immunodeficiency virus (SIV) animal model of HIV infection to study the range of viral genotypes that are transmitted by different routes of inoculation and by different types of viral inocula. Analysis of transmitted variants was undertaken in outbred rhesus macaques inoculated intravenously (IV) or intravaginally (IVAG) with a genetically heterogeneous SIVmac251 stock derived from a well-characterized rhesus macaque viral isolate. In addition, we performed serial IV and IVAG passage experiments using plasma from SIV-infected macaques as the inoculum. We analyzed the V1-V2 region of the SIV envelope gene from virion-associated RNA in plasma from infected animals by the heteroduplex mobility assay (HMA) and by DNA sequence analysis. We found that a more diverse population of SIV genetic variants was present in the earliest virus-positive plasma samples from all five IV SIVmac251-inoculated monkeys and from two of five IVAG SIVmac251-inoculated monkeys. In contrast, we found a relatively homogeneous population of SIV envelope variants in three of five monkeys inoculated IVAG with SIVmac251 stock and in two monkeys infected after IVAG inoculation with plasma from an SIV-infected animal. In some IVAG-inoculated animals, the transmitted SIV variant was the most common variant in the inoculum. However, a specific viral variant in the SIVmac251 stock was not consistently transmitted by IVAG inoculation. Thus, it is likely that host factors or stochastic processes determine the specific viral variants that infect an animal after IVAG SIV exposure. In addition, our results clearly demonstrate that the route of inoculation is associated with the extent and breadth of the genetic complexity of the viral variant population in the earliest stages of systemic infection.
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Samaranayake, Lakshman, and Kausar Sadia Fakhruddin. "SARS-CoV-2 Variants and COVID-19: An Overview." Dental Update 48, no. 3 (2021): 235–38. http://dx.doi.org/10.12968/denu.2021.48.3.235.
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All viruses, including coronaviruses, change over time. This leads to multiple progenies of viral strains, with virulence traits that are unlike those of their parents. This article provides an overview of how viral variants emerge, and the signs and symptoms of variant-related COVID-19.
Dissertations / Theses on the topic "Viral variants"
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Hallett, Rachel Louise. "Molecular epidemiological studies of defined variants of hepatitis B and TT viruses." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251923.
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Hulot, Sandrine. "Reconnaissance de variants d'un épitope viral par des lymphocytes T CD8+ induits par la vaccination de singes rhésus." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2010. http://tel.archives-ouvertes.fr/tel-00598370.
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La diversité génétique du virus de l'immunodéficience humaine, le VIH-1 responsable de la pandémie du SIDA, représente un challenge dans le développement d'un vaccin qui doit conférer une protection contre différentes formes du virus pour être efficace. L'identification de populations de lymphocytes T CD8+ (CTL) capables de reconnaître des variants peptidiques d'un épitope est donc une étape importante. Dans le modèle singes rhésus, j'ai montré en utilisant des tétramères spécifiques de 9 variants peptidiques d'un épitope qu'une même population de CTL générés par la vaccination, peut reconnaître l'épitope relatif à l'immunogène et un certain nombre de ses variants provenant de diverses formes du VIH-1. Ces études ont également permis de caractériser les populations de CTL spécifiques de chaque variant de cet épitope en analysant l'expression des différents gènes codant pour la chaîne variable β du TCR (Vβ répertoire) et par un large séquençage des régions complémentaires déterminantes 3 (CDR3) du TCRβ. Ces travaux ont montré qu'une vaccination utilisant la séquence du clade C de l'enveloppe du VIH-1 conduit à des réponses divergentes chez 2 singes rhésus Mamu-A*01+. De plus, ces résultats ont mis en évidence que l'usage de certainβes nVe permet pas de déterminer le potentiel cross-réactif des CTL. Par ailleurs, une immunisation utilisant des séquences de l'enveloppe du clade B du VIH-1 peut générer des CTL capables de reconnaître un large nombre de variants de l'épitope testé. L'analyse de 8112 séquences CDR3 du TCRβ a permis de les caractériser. Cependant, les tests fonctionnels ont démontré que bon nombre de ces variants peptidiques stimulent une production suboptimale de cytokines par les CTL générés après vaccination. Ces résultats démontrent que la reconnaissance de variant peptidiques d'un épitope est nécessaire mais pas suffisante pour protéger contre différentes formes du VIH-1 exprimant ces séquences. L'identification de variants peptidiques capables d'induire une réponse fonctionnelle des CTL pourrait contribuer au développement d'un vaccin efficace contre le VIH-1.
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Barbosa, Filho Roberto Alexandre Alves. "Clonagem, sequenciamento e estudos moleculares do genoma de HPV 16 isolado na Amazônia." Universidade Federal do Amazonas, 2010. http://tede.ufam.edu.br/handle/tede/3630.
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The Human papillomavirus is responsible for lesions in the oral mucosa, anal and urogenital tract of male and female, transmitted by direct or indirect contact with infected skin or through sexual intercourse. In women these infections can progress to cervical cancer, which is estimated incidence for the Northern region in 2010 was the largest in Brazil. The nature of the infection depends on the degree of integration of viral DNA with host DNA linked primarily to genes of oncoproteins E6 and E7 of HPV. The determination of the viral types can be held from differences in the viral capsid L1 gene and the variants of a particular type of HPV can be identified through the study of viral non-coding region. Currently the development of prophylactic vaccines against HPV particles using "pseudo-viral" formed by the L1 protein of different subtypes of high risk, while a growing number of studies that use the oncoproteins E6 and E7 in the development of therapeutic vaccines. However, it is necessary for the development of such antiviral vaccines also consider the great diversity of variants of HPV types exist, since differences between the genomic regions of these variants may influence the degree of their infections. This paper describes the complete genome sequence of a variant of HPV 16, detected in Amazonian region, using techniques of genetic engineering and the analysis of this genome by bioinformatics tools. It was observed by analysis of genetic distance that the genome of this variant has a genetic proximity of those identified in the literature as "African variants, and phylogenetic analysis, performed from the non-coding region, support this hypothesis. In addition, several mutations were detected in the genome and obtained, resulting in changes in the positions and number of restriction sites in its sequence. The major differences between the genetic regions of the genome sequenced and the corresponding variants in Africa have been observed over E7. It is expected, with that work, look for future research projects involving protein expression and genomic analysis of HPV in the Amazon region to the regional peculiarities in variants and provide a concise and complete reference on the genome of HPV 16 in the region.
O Papillomavirus Humano é responsável por lesões na mucosa oral, anal e do trato urogenital masculino e feminino, transmitidas por contato direto ou indireto com a pele infectada ou através de relações sexuais. Na mulher essas infecções podem evoluir para um câncer de colo do útero, cuja estimativa de incidência para a região Norte no ano de 2010 foi a maior do Brasil. A natureza das infecções depende do grau de integração do DNA viral com o DNA do hospedeiro associada, principalmente, aos genes das oncoproteínas E6 e E7 do HPV. A determinação dos tipos virais pode ser realizada a partir de diferenças no gene L1 do capsídeo viral e as variantes de um determinado tipo de HPV podem ser identificadas por meio do estudo da Região Não Codificadora viral. Atualmente o desenvolvimento de vacinas profiláticas contra o HPV utiliza partículas pseudo-virais formadas pela proteína L1 de tipos virais de alto risco, enquanto cresce o número de estudos que utilizam as oncoproteínas E6 e E7 no desenvolvimento de vacinas terapêuticas. Contudo, é necessário que o desenvolvimento de tais vacinas antivirais também considere a grande diversidade das variantes dos tipos de HPV existentes, uma vez que diferenças entre as regiões genômicas dessas variantes podem influenciar o grau de suas infecções. Este trabalho descreve o sequenciamento completo do genoma de uma variante do HPV 16, detectado no Estado do Amazonas, utilizando técnicas de Engenharia Genética, bem como a análise desse genoma por ferramentas de Bioinformática. Observou-se, pela análise de distâncias genéticas, que o genoma dessa variante apresenta grande proximidade genética dos exemplares identificados na literatura como variantes africanas , e as análises filogenéticas, realizadas a partir da Região Não Codificadora, reforçam essa hipótese. Além disso, também foram detectadas várias mutações ao longo do genoma obtido, resultando em alterações nas posições e na quantidade de sítios de restrição de sua sequência. As maiores diferenças entre as regiões gênicas do genoma sequenciado e as correspondentes nas variantes africanas foram observadas ao longo de E7. Espera-se, com esse trabalho, atentar os futuros projetos de pesquisa que envolvam expressão de proteínas e análises genômicas de HPV na região amazônica para as peculiaridades existentes nas variantes regionais e fornecer uma referência concisa e completa sobre o genoma do HPV 16 na região.
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Labaille, Jennifer. "Conception d'un vaccin recombinant contre la maladie de Marek d'après l'étude de la dynamique des populations de variants du vaccin CV1988/RISPENS." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4014.
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Le Gallid herpesvirus 2 (GaHV-2), responsable de lymphomes T du poulet, est contrôlé par le vaccin CVI988/Rispens. Mes travaux de thèse ont montré que le vaccin était composé, au contraire des souches virulentes, d’une population dynamique de variants viraux majoritairement délétés de la région promotrice et d’une partie variable de l’extrémité 5’ du gène LAT codant des microARN et associé à la latence virale. Dans une approche vaccinale, un virus recombinant correspondant à l’un des variants majoritaires du vaccin CVI988/Rispens a été généré à partir d’une souche GaHV-2 hypervirulente, clonée en bacmide. Nous avons montré que ce recombinant, présentant une perte de pathogénicité presque totale, était capable de protéger significativement les poulets lors d’une épreuve avec des souches GaHV-2 hypervirulentes. Ces travaux posent les bases du développement de nouveaux vaccins à partir de souches hypervirulentes émergentesGallid herpesvirus 2 (GaHV-2), responsible for T-cell lymphomas chicken, is controlled by the vaccine CVI988/Rispens. My work has shown that the vaccine contains, unlike virulent strain, a viral variants population mostly deleted from the promoter region and a variable portion of the 5' end of the gene LAT encoding microRNA and associated with viral latency. In a vaccine approach, a recombinant virus corresponding to a majority variant of the CVI988/Rispens vaccine was generated from a hypervirulent strain GaHV-2, cloned as bacmid. We showed that recombinant, with an almost total loss of pathogenicity, was able to significantly protect chickens against challenge with virulent strains GaHV-2. This work lays the basis for the development of new vaccines from emerging virulent strains
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Hagag, Ibrahim [Verfasser]. "Marek’s disease virus: from novel viral interleukin-8 (vIL-8) splice variants to inhibition with CRISPR/Cas9 / Ibrahim Hagag." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1218076895/34.
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Kishko, Michael G. "Molecular and Functional Properties of Transmitted HIV-1 Envelope Variants: A Dissertation." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/519.
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In 2008 the Nobel Prize in Physiology or Medicine was awarded to the co-discoverers of the Human Immunodeficiency Virus Type 1 (HIV-1), the causative agent of Acquired Immunodeficiency Syndrome (AIDS). This award acknowledged the enormous worldwide impact of the HIV-1/AIDS pandemic and the importance of research aimed at halting its spread. Since the syndrome was first recognized, 25 million people have succumbed to AIDS and over 33 million are currently infected with HIV-1 (www.unaids.org). The most effective strategy for ending the pandemic is the creation of a prophylactic vaccine. Yet, to date, all efforts at HIV-1 vaccine design have met with very limited success. The consistent failures of vaccine candidates stem in large part from the unprecedented diversity of HIV-1.
Among the novel theories of vaccine design put forward to address this diversity is the targeted vaccine approach. This proposal is based on the finding that mucosal transmission of HIV-1, the most prevalent form, occurs across a selective bottleneck such that typically only a single (or a few) variants of the viral swarm present in a donor are passed to the recipient. While the mechanisms controlling the selection are largely unknown, the targeted vaccine approach postulates that once they are identified, we can utilize this understanding to design vaccines specifically targeted to the characteristics shared by the rare, mucosally transmissible HIV-1 variants.
The studies described in this work were conducted to improve our understanding of the factors influencing viral variant selection during mother-to-child-transmission of HIV-1, a route of mucosal transmission which has globally become the leading cause of child infection. A unique panel was generated, consisting of nearly 300 HIV-1 envelope genes cloned from infected mother-infant pairs. Extensive characterization of the genotypes, phenotypes and phylogeny of these clones was then done to identify attributes differentiating early infant from maternal variants. Low genetic diversity of HIV-1 envelope variants was detected in early infant samples, suggesting a bottleneck and active selection of variants for transmission. Transmitted variants did not differ from non-transmitted variants in CD4 and CCR5 use. Infant isolates replicated poorly in macrophages; a cell subtype hypothesized to be important in the establishment of infection. The sensitivity of infant envelope variants to neutralization by a panel of monoclonal antibodies, heterologous and autologous plasmas and HIV-1 entry inhibitors varied. Most intriguingly, envelopes cloned from infants infected during delivery exhibited a faster entry phenotype than maternal isolates. Together, these findings provide further insight into viral variant selection during mother-to-child transmission. Identification of properties shared by mucosally transmitted viral variants may allow them to be selectively targeted, resulting in improved methods for preventing HIV-1 transmission.
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Fins, Ivo Joel Salgueiro. "Molecular surveillance of parvoviruses circulating in cats in the United Kingdom." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23095.
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This dissertation was developed under the Curricular Traineeship scope, which took place at the University of Nottingham, between July 2016 and April 2017. Feline panleukopenia virus (FPV) and canine parvovirus (CPV), two closely related viruses, are known to cause acute enteritis in companion animals. Cats may be infected by strains of both viruses. Population-based surveillance studies have been lacking. This study investigated the prevalence of parvoviruses in a cross-sectional survey of clinically-healthy cats housed within 13 shelters across the United Kingdom, comprising 818 faecal samples. FPV/CPV DNA was detected by PCR. Overall, the prevalence of parvovirus was 3.8%. Five FPV/CPV-2a like strains and one CPV-2b were identified by sequence analysis. These results showed that parvoviruses are circulating in the UK feline population, providing an insight about parvovirus occurrence in a non-clinical population, which reinforces the possibility that asymptomatic cats may be important reservoirs for infection maintenance in companion animals; Resumo:
Vigilância molecular dos Parvovírus circulantes em gatos no Reino Unido
Esta dissertação foi elaborada no âmbito do Estágio Curricular, realizado na Universidade de Nottingham, entre julho de 2016 e abril de 2017. O vírus da panleucopénia felina (FPV) e o parvovirus canino (CPV), dois vírus estreitamente relacionados, são conhecidos por causar enterite aguda em animais de companhia. Os gatos podem ser infetados por estirpes de ambos os vírus. Investigou-se a prevalência de parvovirus através de um estudo transversal em gatos clinicamente saudáveis acolhidos em 13 abrigos de distintas localizações no Reino Unido, somando 818 amostras fecais. O DNA do FPV/CPV foi detetado por PCR. Globalmente, a prevalência de infeção por parvovirus foi de 3,8%. Cinco estirpes virais compatíveis com FPV/CPV-2a e uma estirpe CPV-2b foram identificadas através de sequenciação. Os resultados comprovam que diferentes variantes de parvovirus circulam na população felina do país, reforçando a possibilidade de gatos assintomáticos constituírem reservatórios importantes para manutenção da infeção em animais de companhia.
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Mohr, Christina [Verfasser]. "Influence of hepatitis B virus surface protein variants associated with antiviral resistance on viral assembly and secretion of hepatitis B and hepatitis D viruses / Christina Mohr." Gießen : Universitätsbibliothek, 2014. http://d-nb.info/1068540001/34.
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Gamon, Thaís Helena Martins. "Estudo da etiopatogenia do vírus da raiva utilizando um modelo murino de neuroinfecção." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-16092015-123105/.
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A raiva é uma zoonose quase sempre fatal, que causa milhares de mortes humanas por ano em todo mundo. Essa enfermidade manifesta-se nos mamíferos em duas formas clínicas: furiosa e paralítica. Distinções em relação à evolução, manifestações clínicas, lesões, distribuição e respectiva carga viral no Sistema Nervoso Central (SNC) podem estar relacionadas às características de neuroinvasividade e neuropatogenicidade das diferentes variantes do vírus da raiva (RABV). O objetivo deste projeto foi estabelecer um modelo para o estudo da patogênese da raiva em camundongos inoculados com vírus fixo CVS/31 e variantes de rua do RABV originárias de bovino (variante 3 compatível com isolados de morcegos hematófagos) e de canídeo silvestre (variante compatível com isolados de canídeo silvestre). Para estabelecer o modelo murino, 24 camundongos isogênicos da linhagem BALB/c, de três semanas de idade foram inoculados com 103 DLIC50/0,03mL por via intracerebral (IC) para confirmar a neurovirulência das diferentes variantes do RABV. De modo concomitante, 32 camundongos desta mesma linhagem e faixa etária, foram inoculados com 105 DLIC50/0,03mL pela via coxim plantar (CP) com o intuito de mimetizar a progressão da infecção natural. Para o estudo da patogênese do RABV foram analisados durante um período de trinta dias após a inoculação (DPI) em camundongos pela via CP os seguintes parâmetros: manifestações clínicas, alterações histopatológicas, distribuição antigênica viral pela técnica de imuno-histoquímica (IHQ) e distribuição de RNA viral pela técnica da reação em cadeia da polimerase em tempo real precedida pela transcrição reversa (RT-qPCR) - sistema SYBR Green em diversos segmentos do SNC. Todos os camundongos inoculados com as três amostras do RABV apresentaram sintomas compatíveis com a forma paralítica da doença, tais como: piloereção, perda de peso, postura arqueada, prostração e paresia dos membros posteriores. Apesar de não ser possível observar diferenças de neuropatogenicidade entre as variantes virais, detectaram-se diversidade de virulência entre essas estirpes, demonstrado pelas distinções de período de incubação e taxa de letalidade. Ao analisar os resultados, também foi possível observar diferenças entre a neurovirulência e a neuroinvasividade das diferentes variantes do RABV. Nos camundongos inoculados com CVS/31 pela via CP, no 6º DPI, observaram-se predomínio de manguitos perivasculares na medula espinhal e degeneração neuronal em córtex e intensa distribuição antigênica de RABV no tronco encefálico. Nos camundongos inoculados via CP com amostras do RABV originárias de bovino, no 8º DPI, apresentaram moderada distribuição de manguitos perivasculares na medula e córtex e intensa distribuição antigênica no tálamo. Já nos animais inoculados com a amostra de canídeo silvestre, no 9ºDPI, relataram-se moderada distribuição de manguitos perivasculares no tronco encefálico e moderada distribuição antigênica no córtex. Além disso, foi observado discrepâncias na comparação entre a intensidade e distribuição de marcações antigênicas pela IHQ e inferência semi-quantitativa de distribuição de RNA viral analisada pelo RT-qPCR-sistema SYBR Green no SNC de camundongosRabies is a zoonotic disease usually fatal, causing thousands of human deaths each year worldwide. This disease manifests itself in mammals in two clinical forms: furious and paralytic. Distinctions regarding the evolution, clinical manifestations, injuries, distribution and their viral load on the central nervous system (CNS) may be related to the characteristics of neuroinvasiveness and neuropathogenicity of different variants of rabies virus (RABV). The objective of this project was to establish a model to study the pathogenesis of rabies in mice inoculated with fixed virus CVS / 31 and RABV Street variants originating from bovine (variant 3 - compatible with isolates from vampire bats) and wild canid (variant supports isolated from wild canid). To establish the mouse model, 24 mice of the inbred strain BALB/c, three weeks old were inoculated with 103DLIC50/0,03mL intracerebrally (IC) to confirm the neurovirulence of the different variants of RABV. Concomitantly, 32 mice of the same lineage and age were inoculated with 105DLIC50/0,03mL via footpad (CP) in order to mimic the natural progression of the infection. To study the pathogenesis of RABV CP the following parameters were analyzed over a period of thirty days after inoculation (DPI) in mice via CP: clinical, histopathological changes, viral antigen distribution by the technique of immunohistochemistry (IHC) and distribution of RNA by real-time polymerase chain reaction technique preceded by reverse transcription (RT-qPCR) - SYBR Green system in various segments of the CNS. All mice inoculated with the three RABV samples showed symptoms consistent with the paralytic form of the disease, such as ruffled fur, weight loss, hunched, prostration and paresis of the hind limbs. Although it is not possible to observe neuropathogenicity differences between viral variants, the virulence diversity is detected between these strains demonstrated by distinctions incubation period and fatality rate. When analyzing the results, it was also possible to observe differences between neurovirulence and neuroinvasiveness of different variants of RABV. In mice inoculated with CVS/31 via CP on the 6th DPI, there were predominance of perivascular cuffing in spinal cord and neuronal degeneration in cortex and intense antigenic distribution of the RABV in the brainstem. Mice inoculated via CP with RABV samples originating from bovine on the 8thDPI had moderate distribution of perivascular cuffing in the medulla and cortex and intense antigenic distribution in the thalamus. The animals inoculated with the sample of wild canid in 9thDPI reported a moderate perivascular cuffing distribution in the brainstem and moderate antigenic distribution in the cortex. Additionally, discrepancies were observed when comparing the intensity and distribution of antigenic tags by IHC, semi-quantitative inference viral RNA distribution analyzed by RT-qPCR using SYBR Green system in the mouse CNS
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Menezes, Wanessa Basílio de. "Caracterização Molecular de isolados do vírus rábico dos Estados do RN,PB e PB." Universidade Federal Rural do Semi-Árido, 2013. http://bdtd.ufersa.edu.br:80/tede/handle/tede/336.
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Rabies is a viral disease that affects the central nervous system, causing encephalitis and almost 100% lethality once the signs and symptoms start. This study describes the genetic characterization of rabies virus strains isolated in samples from domestic and wild animals acquired in the states of Rio Grande do Norte, Paraíba and Pernambuco in the period of 2001 to 2012, aiming to contribute to the understanding of the molecular epidemiology of rabies. Eighty fivesamplespositivethrough direct immunofluorescenceandbiological test,provided by theCentral Laboratoryof Public Healthof RioGrande do Norte(LACEN-RN) and theRabies Laboratoryof the Federal Universityof CampinaGrande(UFCG-Campos Patos) were analyzed, and underwent RT-PCR directedto thenucleoprotein geneand subsequentlysequencing was performed.In this study67% ofsampleswere positiveinRT-PCR and 40% presented viablesequences. Theaggregation patternobtainedin the phylogenetic treeresulted in the formationof the main expectedgroupsof rabies virussamples, i.e., antigenic variants2, 3; insectivorous batvariant;andfixed sample(CVS).The study andconstant monitoringof these variantsare extremely important, sincegenetic changescanlead toproteinmodifications, andwith itvaccineinefficiency
A raiva é uma enfermidade de origem viral, que afeta o sistema nervoso central, ocasionando encefalite e praticamente 100% de letalidade uma vez iniciados os sinais e sintomas. Este estudo descreve a caracterização genética das cepas de vírus rábico isoladas de amostras de animais domésticos e silvestres nos Estados do Rio Grande do Norte, Paraíba e Pernambuco no período de 2001 a 20012 visando contribuir para o entendimento da epidemiologia molecular da raiva. Foram analisadas 85 amostras positivas pela imunofluorescência direta e prova biológica cedida pelo Laboratório Central de Saúde Pública do Rio Grande do Norte (LACEN-RN) e o Laboratório de Raiva da Universidade Federal de Campina Grande (UFCG-Campus Patos) e submetidas a RT-PCR direcionada ao gene da nucleoproteína e posterior sequenciamento.No presente estudo 67% da amostras apresentaram positividade na RT-PCR e 40% apresentaram sequencias viáveis. O padrão de agregação obtido na árvore filogenética resultou na formação dos principais grupos esperados de amostras do vírus da raiva, ou seja, variante antigênica 2, 3 e variante de morcego insetívoro e amostra fixa (CVS). O estudo e a monitoração constante dessas variantes são de extrema importância, pois alterações genéticas podem levar a modificações protéicas, e com isso ineficiência vacinal
Books on the topic "Viral variants"
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Sole, Richard, and Santiago F. Elena. Viruses as Complex Adaptive Systems. Princeton University Press, 2018. http://dx.doi.org/10.23943/princeton/9780691158846.001.0001.
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Viruses are everywhere, infecting all sorts of living organisms, from the tiniest bacteria to the largest mammals. Many are harmful parasites, but viruses also play a major role as drivers of our evolution as a species and are essential regulators of the composition and complexity of ecosystems on a global scale. This book draws on complex systems theory to provide a fresh look at viral origins, populations, and evolution, and the coevolutionary dynamics of viruses and their hosts. New viruses continue to emerge that threaten people, crops, and farm animals. Viruses constantly evade our immune systems, and antiviral therapies and vaccination campaigns can be powerless against them. These unique characteristics of virus biology are a consequence of their tremendous evolutionary potential, which enables viruses to quickly adapt to any environmental challenge. This book presents a unified framework for understanding viruses as complex adaptive systems. It shows how the application of complex systems theory to viral dynamics has provided new insights into the development of AIDS in patients infected with HIV-1, the emergence of new antigenic variants of the influenza A virus, and other cutting-edge advances. The book also extends the analogy of viruses to the evolution of other replicators such as computer viruses, cancer, and languages.
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Ralston, Stuart H. Paget’s disease of bone. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199642489.003.0144_update_001.
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Paget’s disease of bone (PDB) affects up to 1% of people of European origin aged 55 years and above. It is characterized by focal abnormalities of bone remodelling which disrupt normal bone architecture, leading to expansion and reduced mechanical strength of affected bones. This can lead to various complications including deformity, fracture, nerve compression syndromes, and osteoarthritis, although many patients are asymptomatic. Genetic factors play a key role in the pathogenesis of PDB. This seems to be mediated by a combination of rare genetic variants which cause familial forms of the disease and common variants which increase susceptibility to environmental triggers. Environmental factors which have been suggested to predispose to PDB include viral infections, calcium and vitamin D deficiency, and excessive mechanical loading of affected bones. The diagnosis can be made by the characteristic changes seen on radiographs, but isotope bone scans are helpful in defining disease extent. Serum alkaline phosphatase levels can be used as a measure of disease activity. Inhibitors of bone resorption are the mainstay of medical management for PDB and bisphosphonates are regarded as the treatment of choice. Bisphosphonates are highly effective at reducing bone turnover in PDB and have been found to heal osteolytic lesions, and normalize bone histology. Although bisphosphonates can improving bone pain caused by elevated bone turnover, most patients require additional therapy to deal with symptoms associated with disease complications. It is currently unclear whether bisphosphonate therapy is effective at preventing complications of PDB.
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Ralston, Stuart H. Paget’s disease of bone. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0144.
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Paget's disease of bone (PDB) affects up to 1% of people of European origin aged 55 years and above. It is characterized by focal abnormalities of bone remodelling which disrupt normal bone architecture, leading to expansion and reduced mechanical strength of affected bones. This can lead to various complications including deformity, fracture, nerve compression syndromes, and osteoarthritis, although many patients are asymptomatic. Genetic factors play a key role in the pathogenesis of PDB. This seems to be mediated by a combination of rare genetic variants which cause familial forms of the disease and common variants which increase susceptibility to environmental triggers. Environmental factors which have been suggested to predispose to PDB include viral infections, calcium and vitamin D deficiency, and excessive mechanical loading of affected bones. The diagnosis can be made by the characteristic changes seen on radiographs, but isotope bone scans are helpful in defining disease extent. Serum alkaline phosphatase levels can be used as a measure of disease activity. Inhibitors of bone resorption are the mainstay of medical management for PDB and bisphosphonates are regarded as the treatment of choice. Bisphosphonates are highly effective at reducing bone turnover in PDB and have been found to heal osteolytic lesions, and normalize bone histology. Although bisphosphonates can improving bone pain caused by elevated bone turnover, most patients require additional therapy to deal with symptoms associated with disease complications. It is currently unclear whether bisphosphonate therapy is effective at preventing complications of PDB.
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Meyrier, Alain, and Patrick Niaudet. Primary focal segmental glomerulosclerosis. Edited by Neil Turner. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0057_update_001.
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Primary focal segmental glomerulosclerosis (FSGS) causes nephrotic syndrome and by definition is not caused by any of the known causes of podocyte toxicity or focal segmental sclerosis such as viral infections or toxins. A number of genetic causes of FSGS are commonly diagnosed in early childhood. Other causes of segmental scarring need to be distinguished. Genotypes in APOL1 of African origin are associated with higher incidence of FSGS and poorer responses to treatment. Cellular and collapsing FSGS are variants of FSGS in which there is overt acute podocytopathy and they have a relatively poor prognosis. A glomerular tip lesion is thought to have a slightly better prognosis than other types. Some cases of primary FSGS respond to high-dose corticosteroids, sometimes only after prolonged therapy. Response to steroids is a good prognostic sign, and without a response, progressive loss of renal function is likely. A circulating factor is implicated by the observation that proteinuria can recur in a donor kidney within hours of transplant. Plasma exchange appears to remove this factor but it is not conclusively identified.
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Crowley, Lara M. “I their forger”. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198821861.003.0005.
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Chapter 5 explores Donne’s lyric poetry in British Library, Additional Manuscript 10309, a seventeenth-century miscellany prepared in a single italic hand. We investigate the manuscript’s eight heavily revised Donne poems, read—and perhaps compiled, even adapted—by Margaret Bellasis. This chapter attends to manuscript features such as titles and verbal variants in these poems, focusing largely on the highly variant versions of “Breake of day” and “The Will.” The verse adapter seems to deploy a consistent pattern of revision that emphasizes sincere love and dilutes bitterness, while still delighting in Donne’s witty premises. These supposedly corrupt texts (very corrupt indeed by traditional editorial standards) provide evidence of a sensitive literary mind at work within Donne’s poems. Through its detailed analysis of verbal adaptations, this chapter contributes a vital study to continuing conversations about early modern women as readers and writers.
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Sample Design, Sampling Weights, Imputation And Variance Estimation in the 1995 National (Vital and health statistics). United States Government Printing, 1998.
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National Survey of Family Growth, Cycle 6: Sample Design, Weighting, Imputation and Variance Estimation (Vital and Health Statistics). Dept. of Health and Human Services Centers fo, 2006.
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Stephens, Piers. Environmental Political Theory and the Liberal Tradition. Edited by Teena Gabrielson, Cheryl Hall, John M. Meyer, and David Schlosberg. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780199685271.013.22.
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This chapter discusses the history of environmental concern within the liberal tradition from the latter’s roots onwards, moving from the private property orientated “old liberalism” of John Locke into the self-development orientated “new liberalism” of John Stuart Mill, then onwards into American pragmatism and the neutralist liberalism of John Rawls and his contemporary followers. This leads into an overview of the current debate, which started in the 1990s, over the possibilities of synthesizing environmentalist goals of sustainability and nature protection with some variant of liberalism. The chapter concludes with an argument that yokes the new liberal concern with self-development to the environmentalist emphasis on nature protection, arguing that the continued existence of relatively untransformed nonhuman nature is a vital precondition and assistance to human imaginative development and thus freedom.
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Martinho, Neudson Johnson, Carolina Carbonell Demori, and João Vitor Andrade. Ciências da saúde: aprendizados, ensino e pesquisa no cenário contemporâneo. Editora Amplla, 2021. http://dx.doi.org/10.51859/amplla.csa511.1121-0.
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Novos desafios surgem a cada dia na área de saúde, os quais vem demonstrando que somente a partir da confluência de saberes e fazeres das diversas áreas do conhecimento os sistemas de saúde estarão fortalecidos para o enfrentamento deles, tendo em vista a complexidade das ações que se fazem necessárias em todos os níveis de atenção: primário, secundário e terciário. As rápidas mudanças epidemiológicas e demográficas, concomitante ao surgimento de pandemias e recrudescimento de doenças transmissíveis e não transmissíveis no mundo, evocam novos olhares e fazeres que requerem transformações desde a formação dos profissionais, produção de conhecimentos com vistas à processos de trabalhos colaborativos nos serviços de saúde, nos quais ocorram uma compreensão quanto a complementariedade dos diversos saberes e fazeres que compõem a equipe de saúde, desconstruindo a cultura das ações sobrepostas ou, a falácia que algumas profissões são mais importantes e portanto, hegemônicas frente as outras. O mundo é complexo e dinâmico, logo, os seres humanos que nele existem também o são em suas dimensões existenciais considerando que estão imbricados no mundo e, por esta característica fenomenológica, o saber / fazer de uma única profissão jamais será capaz de compreender e atender as complexas necessidades factuais destes seres em todo o seu ciclo vital, tendo em vista a imprevisibilidades e incertezas oriundas delas. Com base nas afirmações supracitadas e partindo do princípio de que o trabalho em saúde não tem um produto concreto final, sendo seu resultado consequência das relações profissionais e interpessoais que subjazem suas ações de cuidado e não apenas resultante do saber/fazer de um único profissional, é importante enfatizar que toda a centralidade do processo de trabalho em saúde deve ser o usuário e suas complexas necessidades, as quais só poderão ser realmente atendidas com um cuidado interprofissional / colaborativo. Portanto, mudanças no modus operandi e modus faciendi na formação dos profissionais de saúde e no processo de trabalho suscitam o desenvolvimento de novas competências e habilidades que devem permear a arte de ensinar, pesquisar e extensionar, reverberando no verdadeiro trabalho em equipe nos serviços de saúde, algo somente alcançável através da implementação de uma educação interprofissional nas universidades e cursos técnicos, assim como, a criação de políticas indutoras para o trabalho colaborativo, no qual os diversos saberes e fazeres profissionais sejam valorizados e reconhecidos quanto sua importante complementariedade, visando decisões terapêuticas compartilhadas no atendimento às necessidades de saúde no contexto mundial vigente frente a pandemia de COVID-19 e outras demandas biopsicossociais de cuidado humano. Nesta perspectiva, pensar em ciências da saúde é refletir sobre novos aprendizados, novas metodologias de ensino e novas formas de pesquisar em um cenário contemporâneo que desvela um mix de processos antigos que recrudescem e novos que surgem, apontando a urgência de novas tomadas de decisões, as quais sejam rápidas e eficazes em responder às complexas necessidades dos usuários do sistema de saúde, contribuindo para o resgate e manutenção da qualidade de vida. Desejamos a todos uma profícua leitura desta obra, a qual pela diversidade de temáticas abordadas, permitirá ao leitor não somente uma leitura do mundo sob o prisma dos autores ao socializarem os resultados alcançados em seus estudos, mas, sobretudo, poderá instigá-lo de certa forma à “reescrevê-lo”, no sentido de transformálo a partir da apreensão e ressignificação de conhecimentos contidos nas diferentes pesquisas que corporificam este e-book, permitindo um movimento de cruzamento e interdependência entre variadas competências.
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Martinho, Neudson Johnson, Carolina Carbonell Demori, and João Vitor Andrade. Ciências da saúde: aprendizados, ensino e pesquisa no cenário contemporâneo. 2nd ed. Editora Amplla, 2021. http://dx.doi.org/10.51859/amplla.csa528.2121-0.
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Novos desafios surgem a cada dia na área de saúde, os quais vem demonstrando que somente a partir da confluência de saberes e fazeres das diversas áreas do conhecimento os sistemas de saúde estarão fortalecidos para o enfrentamento deles, tendo em vista a complexidade das ações que se fazem necessárias em todos os níveis de atenção: primário, secundário e terciário. As rápidas mudanças epidemiológicas e demográficas, concomitante ao surgimento de pandemias e recrudescimento de doenças transmissíveis e não transmissíveis no mundo, evocam novos olhares e fazeres que requerem transformações desde a formação dos profissionais, produção de conhecimentos com vistas à processos de trabalhos colaborativos nos serviços de saúde, nos quais ocorram uma compreensão quanto a complementariedade dos diversos saberes e fazeres que compõem a equipe de saúde, desconstruindo a cultura das ações sobrepostas ou, a falácia que algumas profissões são mais importantes e portanto, hegemônicas frente as outras. O mundo é complexo e dinâmico, logo, os seres humanos que nele existem também o são em suas dimensões existenciais considerando que estão imbricados no mundo e, por esta característica fenomenológica, o saber / fazer de uma única profissão jamais será capaz de compreender e atender as complexas necessidades factuais destes seres em todo o seu ciclo vital, tendo em vista a imprevisibilidades e incertezas oriundas delas. Com base nas afirmações supracitadas e partindo do princípio de que o trabalho em saúde não tem um produto concreto final, sendo seu resultado consequência das relações profissionais e interpessoais que subjazem suas ações de cuidado e não apenas resultante do saber/fazer de um único profissional, é importante enfatizar que toda a centralidade do processo de trabalho em saúde deve ser o usuário e suas complexas necessidades, as quais só poderão ser realmente atendidas com um cuidado interprofissional / colaborativo. Portanto, mudanças no modus operandi e modus faciendi na formação dos profissionais de saúde e no processo de trabalho suscitam o desenvolvimento de novas competências e habilidades que devem permear a arte de ensinar, pesquisar e extensionar, reverberando no verdadeiro trabalho em equipe nos serviços de saúde, algo somente alcançável através da implementação de uma educação interprofissional nas universidades e cursos técnicos, assim como, a criação de políticas indutoras para o trabalho colaborativo, no qual os diversos saberes e fazeres profissionais sejam valorizados e reconhecidos quanto sua importante complementariedade, visando decisões terapêuticas compartilhadas no atendimento às necessidades de saúde no contexto mundial vigente frente a pandemia de COVID-19 e outras demandas biopsicossociais de cuidado humano. Nesta perspectiva, pensar em ciências da saúde é refletir sobre novos aprendizados, novas metodologias de ensino e novas formas de pesquisar em um cenário contemporâneo que desvela um mix de processos antigos que recrudescem e novos que surgem, apontando a urgência de novas tomadas de decisões, as quais sejam rápidas e eficazes em responder às complexas necessidades dos usuários do sistema de saúde, contribuindo para o resgate e manutenção da qualidade de vida. Desejamos a todos uma profícua leitura desta obra, a qual pela diversidade de temáticas abordadas, permitirá ao leitor não somente uma leitura do mundo sob o prisma dos autores ao socializarem os resultados alcançados em seus estudos, mas, sobretudo, poderá instigá-lo de certa forma à “reescrevê-lo”, no sentido de transformálo a partir da apreensão e ressignificação de conhecimentos contidos nas diferentes pesquisas que corporificam este e-book, permitindo um movimento de cruzamento e interdependência entre variadas competências.
Book chapters on the topic "Viral variants"
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Jazayeri, Seyed Mohammad, Seyed Moayed Alavian, Payam Dindoost, Howard C. Thomas, and Peter Karayiannis. "Molecular Variants of Hepatitis B Surface Antigen (HBsAg)." In Viral Hepatitis. John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118637272.ch8.
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Bonino, F., and M. R. Brunetto. "Variants of hepatitis B virus." In Chronically Evolving Viral Hepatitis. Springer Vienna, 1992. http://dx.doi.org/10.1007/978-3-7091-5633-9_17.
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Miska, S., and H. Will. "Hepatitis B virus C-gene variants." In Research in Chronic Viral Hepatitis. Springer Vienna, 1993. http://dx.doi.org/10.1007/978-3-7091-9312-9_16.
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Khalid, Sakib, and Jeffrey S. Crippin. "Cholestatic Variants of Viral Disease and Alcohol." In Cholestatic Liver Disease. Humana Press, 2008. http://dx.doi.org/10.1007/978-1-59745-118-5_7.
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Atia, Mary A., and Bashar Aqel. "Cholestatic Variants of Viral Disease and Alcohol." In Clinical Gastroenterology. Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1013-7_7.
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Karayiannis, Peter, William F. Carman, and Howard C. Thomas. "Molecular Variants of the Precore, Core, and Core Promoter Regions of Hepatitis B Virus, and Their Clinical Significance." In Viral Hepatitis. John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118637272.ch9.
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Gauntt, Charles J. "The Possible Role of Viral Variants in Pathogenesis." In Coxsackieviruses. Springer US, 1988. http://dx.doi.org/10.1007/978-1-4757-0247-7_10.
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Howard, Colin R., Vasandra Devi Karthigesu, Lisa M. C. Allison, Marijke Fortuin, Maimuna Mendy, and Hilton C. Whittle. "Hepatitis B Virus Variants with Altered a Determinants Causing Infections in Immunized Children." In Viral Hepatitis and Liver Disease. Springer Japan, 1994. http://dx.doi.org/10.1007/978-4-431-68255-4_63.
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Naidu, Vijay, and Ajit Narayanan. "A Syntactic Approach for Detecting Viral Polymorphic Malware Variants." In Intelligence and Security Informatics. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-31863-9_11.
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Hotta, Hak, Hisaya Doi, Takako Hayashi, et al. "Sequence Analysis of Hepatitis C Virus Obtained from Indonesian Patients and Identification of Novel Sequence Variants." In Viral Hepatitis and Liver Disease. Springer Japan, 1994. http://dx.doi.org/10.1007/978-4-431-68255-4_76.
Full textConference papers on the topic "Viral variants"
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Naidu, Vijay, and Ajit Narayanan. "Needleman-Wunsch and Smith-Waterman Algorithms for Identifying Viral Polymorphic Malware Variants." In 2016 IEEE 14th Intl Conf on Dependable, Autonomic and Secure Computing, 14th Intl Conf on Pervasive Intelligence and Computing, 2nd Intl Conf on Big Data Intelligence and Computing and Cyber Science and Technology Congress(DASC/PiCom/DataCom/CyberSciTech)2016. IEEE, 2016. http://dx.doi.org/10.1109/dasc-picom-datacom-cyberscitec.2016.73.
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Campo, David S., Zoya Dimitrova, Guo-Liang Xia, Pavel Skums, Lilia Ganova-Raeva, and Yury Khudyakov. "New computational methods for assessing the genetic relatedness of close viral variants." In 2014 IEEE 4th International Conference on Computational Advances in Bio and Medical Sciences (ICCABS). IEEE, 2014. http://dx.doi.org/10.1109/iccabs.2014.6863937.
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Naidu, Vijay, and Ajit Narayanan. "Using different substitution matrices in a string-matching technique for identifying viral polymorphic malware variants." In 2016 IEEE Congress on Evolutionary Computation (CEC). IEEE, 2016. http://dx.doi.org/10.1109/cec.2016.7744156.
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Fischer, J., S. Long, E. Koukoulioti, et al. "Genetic variants of interleukin 1 beta are associated with viral hepatitis-related HCC in Caucasian patients." In 37. Jahrestagung der Deutschen Arbeitsgemeinschaft zum Studium der Leber. Georg Thieme Verlag KG, 2021. http://dx.doi.org/10.1055/s-0040-1722060.
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Benslimane, Fatiha M., Hebah Al Khatib, Dana Albatesh, et al. "Nanopore Sequencing SARS-CoV-2 Genome in Qatar." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0289.
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Background: The current pandemic, COVID-19, is cause by an RNA Coronavirus that was recently identified as SARS-CoV-2. RNA viruses tend to have a high mutation rate; the rate is around a million times greater than that of their hosts. The mutagenic potential of the virus depends on many factors, including the fidelity of nucleic acid-replicating viral enzymes, such as SARSCoV-2 RNA dependent RNA polymerase (RdRp). The rate of mutation drives viral evolution and genome variability, consequently allowing viruses to escape the immunity of the host and develop resistance to drugs. Therefore, the characterization of SARS-CoV-2 variants might lead to implement better therapeutics treatments, vaccines design and identify new diagnostics approaches. Aim: The aim of this study was to establish a fast sequencing method to identify SARS-CoV-2 mutations in Qatar. This will help to assess if there are new viral variants that are spreading in country. Methods: RNA was isolated from samples collected from Qatar COVID-19 positive patients. The Artic Network V3 primer scheme and Oxford Nanopore ligation sequencing kit were used to prepare the sequencing libraries. Libraries were loaded on to R9.4.1 flow cells and ran on a GridION. Bioinformatics analysis was done following the Artic Network SARA-CoV-2 bioinformatics tools. Results: Genome coverage of sequenced samples was >80% and the depth was average at 200x. The coverage was highly dependable on sample viral load; samples of CT value lower than 30 resulted in better sequence coverage. The sequenced genomes were deposited in GISAID and were mainly clustering with genomes deposited from the UK. Sequences were compared to Illumina and sanger sequences and they showed compatible results. Conclusion: The use of ONT to sequence SARA-CoV-2 is a quick, affordable, and reliable technique to determine viral mutation. Using this technique, the first sequences from Qatar were deposited in to GISAID. Up to date, 700 genomes have been sequenced from Qatari samples.
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Acosta-Leal, Rodolfo, Becky Bryan, and Charlie M. Rush. "Host and viral factors that promote the emergence of resistance breaking variants of Beet necrotic yellow vein virus (BNYW)." In American Society of Sugar Beet Technologist. ASSBT, 2007. http://dx.doi.org/10.5274/assbt.2007.39.
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Al Khatib, Hebah A., Fatiha M. Benslimane, Israa El Bashir, Asmaa A. Al Thani, and Hadi M. Yassine. "Within-Host Diversity of SARS-Cov-2 in COVID-19 Patients with Variable Disease Severities." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0280.
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Background: The ongoing pandemic of SARS-COV-2 has already infected more than eight million people worldwide. The majority of COVID-19 patients are either asymptomatic or have mild symptoms. Yet, about 15% of the cases experience severe complications and require intensive care. Factors determining disease severity are not yet fully characterized. Aim: Here, we investigated the within-host virus diversity in COVID-19 patients with different clinical manifestations. Methods: We compared SARS-COV-2 genetic diversity in 19 mild and 27 severe cases. Viral RNA was extracted from nasopharyngeal samples and sequenced using Illumina MiSeq platform. This was followed by deep-sequencing analyses of SARS-CoV-2 genomes at both consensus and sub-consensus sequence levels. Results: Consensus sequences of all viruses were very similar, showing more than 99·8% sequence identity regardless of the disease severity. However, the sub-consensus analysis revealed significant differences in within-host diversity between mild and severe cases. Patients with severe symptoms exhibited a significantly (p-value 0.001) higher number of variants in coding and non-coding regions compared to mild cases. Analysis also revealed higher prevalence of some variants among severe cases. Most importantly, severe cases exhibited significantly higher within-host diversity (mean= 13) compared to mild cases (mean=6). Further, higher within-host diversity was observed in patients above the age of 60 compared to the younger age group. Conclusion: These observations provided evidence that within-host diversity might play a role in the development of severe disease outcomes in COVID19 patients; however, further investigations is required to elucidate this association.
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Sarver, Nava, and George A. Ricca. "SUSTAINED EXPRESSION OF FULL LENGTH AND VARIANT RECOMBINANT FACTOR VIII IN GENETICALLY ENGINEERED CELLS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643875.
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A major effort is presently underway to provide factor VIII (FVIII) in a form free of viral pathogens via a recombinant DNA approach. We have constructed two chimeric FVIII cDNA vectors based on the bovine papillomavirus mammalian expression system. The first vector (FVIII) contained a full length FVIII cDNA; the second vector (AFVIII) contained a cDNA insert with an extensive deletion, corresponding to amino acid residues 747 to 1560 in the region encoding the "B" domain. This internal region is removed during activation of the parental FVIII molecule and is believed not to be required for coagulant activity. We have found that recombinant FVIII produced by stable cell lines harboring either the full length or the variant FVIII was capable of restoring coagulant activity to FVIII deficient plasma in. vitro. This expressed activity was neutralized by anti-FVIII antibodies. Similar to observations with FVIII derived from human plasma, the two recombinant FVIII forms were (i) inactivated by the chelating agent EDTA, (ii) demonstrated a biphasic response of an initial activation followed by a decay in activity when treated with thrombin, and (iii) presented the expected peptide banding pattern by western blot analyses. A higher percentage of ΔFVIII transformants were isolated expressing coagulant activity compared to transformants harboring the complete FVIII cDNA. Among the positive transformants isolated, those harboring ΔFVIII produced higher levels of coagulant activity than their full length counterparts. Comparable steady state levels of FVIII specific transcripts were detected in FVIII and ΔFVIII transformants indicating that the difference in expression levels is due to a post transcriptional event(s). Our study demonstrates the efficacy of a full length and an abridged recombinant FVIII produced by stably transformed cells in correcting coagulation deficiency in. vitro. It further suggests the potential usefulness of other molecular variants for efficient expression in genetically engineered cells.
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Cano Rosás, Mónica, María Yolanda González Alonso, Raquel Aceves Díez, Thaís Pousada García, Estíbaliz Jimenez Arberas, and Emiliano Díez Villoria. "Propuesta de Innovación docente para el aprendizaje Interdisciplinar sobre Diseño para todas las personas entre estudiantes de los Grados de Odontología y de Terapia Ocupacional de diferentes Universidades españolas." In IN-RED 2019: V Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/inred2019.2019.10382.
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Enseñar “diseño para todas las personas” a los estudiantes de Ciencias de la Salud es vital para que en el futuro sean capaces de “diseñar productos y entornos de fácil uso para el mayor número de personas posible, sin la necesidad de adaptarlos o rediseñarlos de una forma especial”. Por eso, durante los primeros años de implantación de los títulos de grado, se han venido planteando distintos tipos de acciones dirigidas a incluir contenidos curriculares sobre diseño para todas las personas de maneras muy variadas. Por ejemplo, mediante asignaturas específicas o con planteamientos curriculares transversales que reparten la enseñanza en distintas asignaturas. El objetivo general del proyecto ha sido diseñar un conjunto de actividades de carácter interdisciplinar entre estudiantes del Grado de Odontología y del Grado de Terapia Ocupacional de varias universidades españolas para intercambiar información y experiencias en relación a la aplicación de los principios del diseño para todas las personas.
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Park, J., H. E. Cho, J. Byun, E. Kim, W. A. Choi, and S. W. Kang. "Effect of Positional Variance of Vital Capacity on Postural Transcutaneous Monitoring: A Preliminary Study." In American Thoracic Society 2020 International Conference, May 15-20, 2020 - Philadelphia, PA. American Thoracic Society, 2020. http://dx.doi.org/10.1164/ajrccm-conference.2020.201.1_meetingabstracts.a5514.
Full textReports on the topic "Viral variants"
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Bhatt, Mihir R., Shilpi Srivastava, Megan Schmidt-Sane, and Lyla Mehta. Key Considerations: India's Deadly Second COVID-19 Wave: Addressing Impacts and Building Preparedness Against Future Waves. Institute of Development Studies (IDS), 2021. http://dx.doi.org/10.19088/sshap.2021.031.
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Since February 2021, countless lives have been lost in India, which has compounded the social and economic devastation caused by the second wave of COVID-19. The sharp surge in cases across the country overwhelmed the health infrastructure, with people left scrambling for hospital beds, critical drugs, and oxygen. As of May 2021, infections began to come down in urban areas. However, the effects of the second wave continued to be felt in rural areas. This is the worst humanitarian and public health crisis the country has witnessed since independence; while the continued spread of COVID-19 variants will have regional and global implications. With a slow vaccine rollout and overwhelmed health infrastructure, there is a critical need to examine India's response and recommend measures to further arrest the current spread of infection and to prevent and prepare against future waves. This brief is a rapid social science review and analysis of the second wave of COVID-19 in India. It draws on emerging reports, literature, and regional social science expertise to examine reasons for the second wave, explain its impact, and highlight the systemic issues that hindered the response. This brief puts forth vital considerations for local and national government, civil society, and humanitarian actors at global and national levels, with implications for future waves of COVID-19 in low- and middle-income countries. This review is part of the Social Science in Humanitarian Action Platform (SSHAP) series on the COVID-19 response in India. It was developed for SSHAP by Mihir R. Bhatt (AIDMI), Shilpi Srivastava (IDS), Megan Schmidt-Sane (IDS), and Lyla Mehta (IDS) with input and reviews from Deepak Sanan (Former Civil Servant; Senior Visiting Fellow, Centre for Policy Research), Subir Sinha (SOAS), Murad Banaji (Middlesex University London), Delhi Rose Angom (Oxfam India), Olivia Tulloch (Anthrologica) and Santiago Ripoll (IDS). It is the responsibility of SSHAP.