170 research outputs found
Hepatitis C viral evolution in genotype 1 treatment-naïve and treatment-experienced patients receiving telaprevir-based therapy in clinical trials
Background: In patients with genotype 1 chronic hepatitis C infection, telaprevir (TVR) in combination with peginterferon and ribavirin (PR) significantly increased sustained virologic response (SVR) rates compared with PR alone. However, genotypic changes could be observed in TVR-treated patients who did not achieve an SVR.
Methods: Population sequence analysis of the NS3•4A region was performed in patients who did not achieve SVR with TVR-based treatment.
Results: Resistant variants were observed after treatment with a telaprevir-based regimen in 12% of treatment-naïve patients (ADVANCE; T12PR arm), 6% of prior relapsers, 24% of prior partial responders, and 51% of prior null responder patients (REALIZE, T12PR48 arms). NS3 protease variants V36M, R155K, and V36M+R155K emerged frequently in patients with genotype 1a and V36A, T54A, and A156S/T in patients with genotype 1b. Lower-level resistance to telaprevir was conferred by V36A/M, T54A/S, R155K/T, and A156S variants; and higher-level resistance to telaprevir was conferred by A156T and V36M+R155K variants. Virologic failure during telaprevir treatment was more common in patients with genotype 1a and in prior PR nonresponder patients and was associated with higher-level telaprevir-resistant variants. Relapse was usually associated with wild-type or lower-level resistant variants. After treatment, viral populations were wild-type with a median time of 10 months for genotype 1a and 3 weeks for genotype 1b patients.
Conclusions: A consistent, subtype-dependent resistance profile was observed in patients who did not achieve an SVR with telaprevir-based treatment. The primary role of TVR is to inhibit wild-type virus and variants with lower-levels of resistance to telaprevir. The complementary role of PR is to clear any remaining telaprevir-resistant variants, especially higher-level telaprevir-resistant variants. Resistant variants are detectable in most patients who fail to achieve SVR, but their levels decline over time after treatment
Sequence-tagged sites (STSs) for a set of mapped markers on chromosome 21
Sequence tagged sites (STSs) have been proposed as a "common language" for comparing physical and genetic maps of the human genome produced by a variety of techniques. We have produced 44 STSs from 38 mapped loci on human chromosome 21. The STSs represent most of the loci designated as genetic reference or ordered physical framework markers, along with a number of others chosen to span all regions of 21q. Of the STSs, 12 are from gene segments, including 4 from exons of the APP gene encoding the amyloid [beta] protein precursor, and 32 mark anonymous DNA loci. These STSs make each of the corresponding loci readily accessible to the research community without the need for exchange of clones. These sites also represent multiple start points for the isolation of YAC clones that should permit overlapping the entire chromosome 21 long arm as cloned DNA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29821/1/0000167.pd
Women and Haunted Houses in the Films of Jaume Balagueró: The Nightmares of Presence
Jaume Balagueró has developed a successful resumé of horror films that show a decided preference for the classic Gothic motif of the haunted house and the Gothic heroine who investigates its interior. This paper touches first on the Derridean concept of ‘dreams of presence’ (as theorized by cultural geographer Mitch Rose), in order to propose the ‘nightmares of presence’ in which the relationship, the call to care or commitment, between the subject and the space in which the subject dwells or moves is Gothicised but nonetheless remains to tie the subject to the space concerned. It then focuses on Balagueró’s Los sin nombre, Fragile and [REC] to consider three very different Gothic heroines: the mother of a dead daughter, a nurse in a children’s hospital, and a television reporter. The antagonistic call to care of the ‘nightmare of presence’ will be used to interrogate spatial aspects of the Gothic heroine. Keywords: Jaume Balagueró; haunted house; Spanish Gothic; Spanish horror; Spanish film Jaume Balagueró ha desarrollado un grupo de películas exitosas que demuestra una preferencia hacia el escenario clásico de lo gótico, la casa encantada tanto como la heroína gótica que la investiga. Este ensayo estudia en primer lugar el concepto derrideano de ‘los sueños de presencia’ (según la teoría de geógrafo cultural Mitch Rose), para proponer las ‘pesadillas de presencia’ en que el vínculo, la llamada a compromiso, entre el sujeto y el espacio en que se mueve o que habita, llega a ser gotizado; pero que fija al sujeto en el espacio relevante. El argumento se enfoca en Los sin nombre, Fragile y [REC] para considerar tres heroínas distintas: la madre de una hija muerta, una enfermera en un hospital para niños, y una locutora para un programa televisivo. La llamada antagonista de la pesadilla de presencia se usa para interrogar los aspectos espaciales de la heroína gótica
Crafting Critical Heritage Discourses into Interactive Exhibition Design
This paper argues how a more reflective design practice that embraces critical discourses can transform interactive exhibition design and therefore the museum visiting experience. Four framing arguments underpin our exhibition design making: the value of materiality, visiting as an aesthetic experience, challenging the authorized voice, and heritage as a process. These arguments were embodied through design, art and craft practice into one interactive exhibition at a house museum. We draw from our design process discussing the implications that adopting an approach informed by critical heritage debates has on exhibition design and suggest three sensitizing concepts (polyvocal narratives, dialogical interaction, interweaving time and space) bridging the practice of interactive exhibition design and critical heritage theory
Crop wild relatives of the brinjal eggplant ( Solanum melongena ): Poorly represented in genebanks and many species at risk of extinction
This is the publisher's Early View pdf without final pagination .© 2016 Botanical Society of America. This is an open access article, available to all readers online, published under a creative commons license. The attached file is the published version of the article
Rare Species Support Vulnerable Functions in High-Diversity Ecosystems
Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species. This issue is even more critical in species-rich ecosystems where high functional redundancy among species is likely and where it is thus often assumed that ecosystem functioning is buffered against species loss. Here, using extensive datasets of species occurrences and functional traits from three highly diverse ecosystems (846 coral reef fishes, 2,979 alpine plants, and 662 tropical trees), we demonstrate that the most distinct combinations of traits are supported predominantly by rare species both in terms of local abundance and regional occupancy. Moreover, species that have low functional redundancy and are likely to support the most vulnerable functions, with no other species carrying similar combinations of traits, are rarer than expected by chance in all three ecosystems. For instance, 63% and 98% of fish species that are likely to support highly vulnerable functions in coral reef ecosystems are locally and regionally rare, respectively. For alpine plants, 32% and 89% of such species are locally and regionally rare, respectively. Remarkably, 47% of fish species and 55% of tropical tree species that are likely to support highly vulnerable functions have only one individual per sample on average. Our results emphasize the importance of rare species conservation, even in highly diverse ecosystems, which are thought to exhibit high functional redundancy. Rare species offer more than aesthetic, cultural, or taxonomic diversity value; they disproportionately increase the potential breadth of functions provided by ecosystems across spatial scales. As such, they are likely to insure against future uncertainty arising from climate change and the ever-increasing anthropogenic pressures on ecosystems. Our results call for a more detailed understanding of the role of rarity and functional vulnerability in ecosystem functioning
Global human footprint on the linkage between biodiversity and ecosystem functioning in reef fishes
Copyright: © 2011 Mora et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Difficulties in scaling up theoretical and experimental results have raised controversy over the consequences of biodiversity loss for the functioning of natural ecosystems. Using a global survey of reef fish assemblages, we show that in contrast to previous theoretical and experimental studies, ecosystem functioning (as measured by standing biomass) scales in a non-saturating manner with biodiversity (as measured by species and functional richness) in this ecosystem. Our field study also shows a significant and negative interaction between human population density and biodiversity on ecosystem functioning (i.e., for the same human density there were larger reductions in standing biomass at more diverse reefs). Human effects were found to be related to fishing, coastal development, and land use stressors, and currently affect over 75% of the world's coral reefs. Our results indicate that the consequences of biodiversity loss in coral reefs have been considerably underestimated based on existing knowledge and that reef fish assemblages, particularly the most diverse, are greatly vulnerable to the expansion and intensity of anthropogenic stressors in coastal areas
Investigating orphan cytochromes P450 from Mycobacterium tuberculosis : the search for potential drug targets
Tuberculosis (TB) is a disease that the World Health Organisation (WHO) regards as a global pandemic. There is a great need for new drugs to combat this threat. Drug resistant strains of the causative agent, Mycobacterium tuberculosis (Mtb), have increased the urgency of this quest for novel anti-mycobacterial medicines. Publication of the Mtb genome sequence revealed a large number of cytochrome P450 (CYP) enzymes [Cole, S. T. et al. 1998]. These mono-oxygenase enzymes have been studied for many years and are responsible for metabolic functions in every kingdom of life. Research on the Mtb P450s to date has highlighted several of them as having critcal roles within the organism. CYP121 and CYP128 have been implicated as essential through gene knockout studies. It has been demonstrated that CYP125 is not essential for viability. However, it is part of a gene cluster highly important for Mtb infectivity and virulence. Due to the prospective importance of P450s to Mtb, this group of enzymes is under investigation as a source of novel drug targets. CYP142 was discovered as a potential drug target after it was located to a gene cluster involved in cholesterol catabolism during Mtb dormancy. As part of this PhD project, it was demonstrated that CYP142 performs an almost identical role to that reported for CYP125. These enzymes both perform C27 hydroxylation and carboxylation of the cholesterol side chain. However, variations in the level of oxidation have been identified, dependent upon the redox system with which these P450s are associated. A crystal structure of CYP142 showing high similarity in active site architecture to CYP125 supports the physiological role of CYP142 in cholesterol catabolism. Combining this with in vitro data which demonstrates that CYP142 possesses high affinity for a range of azole anti-fungal agents [Ahmad, Z. et al. 2005, 2006] supports the suggestion that it is a candidate target for the next generation of anti-mycobacterial drugs. CYP144 was highlighted as being important during the latent phase of Mtb growth, a phase that is not targeted by any of the current antimycobacterials. Work performed as part of this PhD has shown that many characteristics of CYP144 are highly comparable to those reported for other MtbP450s. CYP144 shows high affinity and specificity towards many azole molecules. Econazole, clotrimazole and miconazole have repeatedly been shown to bind to MtbP450s, including CYP144 and CYP142, with high affinity and are excellent potential candidates as novel anti-mycobacterial agents. An N-terminally truncated form of CYP144, CYP144-T, has been investigated in the pursuit of a CYP144 crystal structure. It is hoped that this will enable the elucidation of a physiological role for CYP144. Both CYP142 and CYP144 have demonstrated biochemical and biophysical characteristics that contribute to our knowledge of P450 enzymes. This PhD has established that CYP142 exhibits an equilibrium between P450 and P420 species in its CO-bound, ferrous form. A conversion from P420, and stabilisation of P450, upon substrate binding was also demonstrated. CYP144 displays unusual azole coordination characteristics when examined by EPR and removal of the CYP144 gene from Mtb increased sensitivity of the strain to clotrimazole. Studies of these enzymes has advanced knowledge of P450 and Mtb redox chemistry, established roles for the MtbP450 cohort and identified the potential of anti-mycobacterial drugs and associated targets.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases
The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article
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