102 research outputs found
Transmission of Human Immunodeficiency Virus I Drug Resistance - a Case Report. What are the Clinical Implications?
The success of first-line antiretroviral therapy can be challenged by the acquisition of primary drug resistance. Here we report a case where baseline genotypic resistance testing detected resistance conferring nucleoside/nucleotide reverse transcriptase inhibitor (NRTI)-associated mutations, but no primary mutations for protease inhibitor (PI). Subsequent PI-based HAART with boosted saquinavir led to virological treatment success with persistently undetectable viral load. After treatment simplification from saquinavir to an atazanavir based PI-therapy and no change in backbone therapy rapid virological breakthrough occurred. Retrospective analysis displayed preexisting gag cleavage site mutations which may have reduced the genetic barrier in a clinical relevant manner in combination with the already existing NRTI resistance mutations. Alternatively, this effect could be explained with a different antiviral potency for the respective PIs used
A transcriptomic analysis of Echinococcus granulosus larval stages:implications for parasite biology and host adaptation
The cestode Echinococcus granulosus--the agent of cystic echinococcosis, a zoonosis affecting humans and domestic animals worldwide--is an excellent model for the study of host-parasite cross-talk that interfaces with two mammalian hosts. To develop the molecular analysis of these interactions, we carried out an EST survey of E. granulosus larval stages. We report the salient features of this study with a focus on genes reflecting physiological adaptations of different parasite stages.We generated ~10,000 ESTs from two sets of full-length enriched libraries (derived from oligo-capped and trans-spliced cDNAs) prepared with three parasite materials: hydatid cyst wall, larval worms (protoscoleces), and pepsin/H(+)-activated protoscoleces. The ESTs were clustered into 2700 distinct gene products. In the context of the biology of E. granulosus, our analyses reveal: (i) a diverse group of abundant long non-protein coding transcripts showing homology to a middle repetitive element (EgBRep) that could either be active molecular species or represent precursors of small RNAs (like piRNAs); (ii) an up-regulation of fermentative pathways in the tissue of the cyst wall; (iii) highly expressed thiol- and selenol-dependent antioxidant enzyme targets of thioredoxin glutathione reductase, the functional hub of redox metabolism in parasitic flatworms; (iv) candidate apomucins for the external layer of the tissue-dwelling hydatid cyst, a mucin-rich structure that is critical for survival in the intermediate host; (v) a set of tetraspanins, a protein family that appears to have expanded in the cestode lineage; and (vi) a set of platyhelminth-specific gene products that may offer targets for novel pan-platyhelminth drug development.This survey has greatly increased the quality and the quantity of the molecular information on E. granulosus and constitutes a valuable resource for gene prediction on the parasite genome and for further genomic and proteomic analyses focused on cestodes and platyhelminths
Cancer risk in HIV-infected individuals on HAART is largely attributed to oncogenic infections and state of immunocompetence
<p>Abstract</p> <p>Objectives</p> <p>To estimate the cancer risk of HIV-infected patients in the HAART era with respect to a general reference population and to determine risk factors for malignancy.</p> <p>Methods</p> <p>Long term (1996-2009) cancer incidence of the Bonn single centre HIV cohort was compared to the incidence of the reference population of Saarland using standardized incidence ratios (SIR). Poisson regression analysis was used to identify predictors of cancer risk.</p> <p>Results</p> <p>1,476 patients entered the cohort, enabling 8,772 person years of observation. 121 tumours in 114 patients, 7 in-situ and 114 invasive cancers, were identified. Malignancies associated with infectious agents such as Kaposi sarcoma (SIRs: male: 5,683; female: 277), non-Hodgkin lymphoma (SIRs male: 35; female: 18), anal cancer (SIRs male: 88; female: 115) as well a cervical carcinoma (SIR female: 4) and Hodgkin's disease (SIR male: 39) and liver cancer (SIR male: 18) were substantially more frequent in HIV-infected patients than in the general population (p < 0.001, each), whereas all other types of cancer were not increased. Poisson regression identified HAART (incidence rate ratio IRR (95% CI): 0.28 (0.19-0.41), p < 0.001), CD4 count (IRR per 100 cells/μl increase: 0.66 (0.57-0.76), p < 0.001), hepatitis B (IRR: 2.15 (1.10-4.20), p = 0.046) and age (IRR per 10 year increase: 1.23 (1.03 - 1.46), p = 0.023) as independent predictors for the occurrence of any type of cancer.</p> <p>Conclusions</p> <p>HAART and preserved CD4 cells preferentially reduce the risk of malignancies associated with oncogenic infections.</p
Associations between change in BMI and the risk of hypertension and dyslipidaemia in people receiving integrase strand-transfer inhibitors, tenofovir alafenamide, or both compared with other contemporary antiretroviral regimens: a multicentre, prospective observational study from the RESPOND consortium cohorts
BACKGROUND:
Integrase strand-transfer inhibitors (INSTIs) and tenofovir alafenamide have been associated with weight gain in several clinical trials and observational cohorts. However, whether weight gain associated with INSTIs and tenofovir alafenamide confers a higher risk of weight-related clinical events is unclear. We aimed to assess whether changes in BMI differentially increase hypertension or dyslipidaemia risk in people with HIV receiving INSTIs, tenofovir alafenamide, or both versus other contemporary regimens.
METHODS:
This multicentre, prospective observational study analysed prospective data from RESPOND, an international consortium of HIV cohorts for which recruitment began in 2017 and is still ongoing from HIV clinics and hospitals in 37 European countries and Australia. Participants were eligible if they were aged 18 years or older, receiving INSTI-containing antiretroviral therapy (ART) regimens or a contemporary non-INSTI, did not have hypertension or dyslipidaemia at baseline, and had baseline and at least two follow-up BMI, lipid, and blood pressure measurements. We excluded participants without baseline CD4 or HIV RNA results and those receiving non-ART medications associated with weight changes, including antipsychotics and mood stabilisers, corticosteroids, insulin, and insulin secretagogues. They were followed up from baseline until the earliest hypertension or dyslipidaemia event, their last visit, or Dec 31, 2021, whichever was earlier. The primary outcomes were incidence of hypertension and dyslipidaemia, for which we used multivariable Poisson regression adjusted for time-updated BMI to determine unadjusted and adjusted incidence rate ratios (IRRs) of hypertension and dyslipidaemia in people receiving INSTIs, tenofovir alafenamide, or both, and tested for interaction between time-updated ART regimen and BMI.
FINDINGS:
Of the 35 941 RESPOND participants, 9704 (7327 [75·5 %] male and 2377 [24·5%] female) were included in the hypertension analysis and 5231 (3796 [72·6%] male and 1435 [27·4%] female) were included in the dyslipidaemia analysis. In the univariable model, hypertension was more common in individuals receiving an INSTI with tenofovir alafenamide (IRR 1·70, 95% CI 1·54–1·88) or an INSTI without tenofovir alafenamide (1·41, 1·30–1·53) compared with those receiving neither INSTIs nor tenofovir alafenamide. Adjustment for time-updated BMI and confounders attenuated risk in participants receiving an INSTI with (IRR 1·48, 1·31–1·68) or without (1·25, 1·13–1·39) tenofovir alafenamide. Similarly, dyslipidaemia was more common in participants using tenofovir alafenamide with an INSTI (IRR 1·24, 1·10–1·40) and tenofovir alafenamide alone (1·22, 1·03–1·44) than in participants using neither INSTI nor tenofovir alafenamide. Adjustment for BMI and confounders attenuated the risk in participants receiving tenofovir alafenamide with an INSTI (adjusted IRR 1·21, 1·07–1·37), whereas the risk in those receiving tenofovir alafenamide alone became non-significant (1·15, 0·96–1·38). The associations between increasing BMI and risk of hypertension and dyslipidaemia did not differ between participants receiving different ART regimens (pinteraction=0·46 for hypertension; pinteraction=0·31 for dyslipidaemia).
INTERPRETATION:
Although residual confounding cannot be entirely excluded, the use of INSTIs was associated with incident hypertension, and the use of tenofovir alafenamide was associated with dyslipidaemia, with the latter association partly mediated by weight gain. These results reiterate the need for hypertension and dyslipidaemia screening in people with HIV.
FUNDING:
The CHU St Pierre Brussels HIV Cohort, The Austrian HIV Cohort Study, The Australian HIV Observational Database, The AIDS Therapy Evaluation in the Netherlands national observational HIV cohort, The Brighton HIV Cohort, The National Croatian HIV Cohort, The EuroSIDA cohort, The Frankfurt HIV Cohort Study, The Georgian National AIDS Health Information System, The Nice HIV Cohort, The ICONA Foundation, The Modena HIV Cohort, The PISCIS Cohort Study, The Swiss HIV Cohort Study, The Swedish InfCare HIV Cohort, The Royal Free HIV Cohort Study, The San Raffaele Scientific Institute, The University Hospital Bonn HIV Cohort, The University of Cologne HIV Cohort, Merck Life Sciences, ViiV Healthcare, and Gilead Sciences
Next generation transcriptomes for next generation genomes using est2assembly
<p>Abstract</p> <p>Background</p> <p>The decreasing costs of capillary-based Sanger sequencing and next generation technologies, such as 454 pyrosequencing, have prompted an explosion of transcriptome projects in non-model species, where even shallow sequencing of transcriptomes can now be used to examine a range of research questions. This rapid growth in data has outstripped the ability of researchers working on non-model species to analyze and mine transcriptome data efficiently.</p> <p>Results</p> <p>Here we present a semi-automated platform '<it>est2assembly</it>' that processes raw sequence data from Sanger or 454 sequencing into a hybrid <it>de-novo </it>assembly, annotates it and produces GMOD compatible output, including a SeqFeature database suitable for GBrowse. Users are able to parameterize assembler variables, judge assembly quality and determine the optimal assembly for their specific needs. We used <it>est2assembly </it>to process <it>Drosophila </it>and <it>Bicyclus </it>public Sanger EST data and then compared them to published 454 data as well as eight new insect transcriptome collections.</p> <p>Conclusions</p> <p>Analysis of such a wide variety of data allows us to understand how these new technologies can assist EST project design. We determine that assembler parameterization is as essential as standardized methods to judge the output of ESTs projects. Further, even shallow sequencing using 454 produces sufficient data to be of wide use to the community. <it>est2assembly </it>is an important tool to assist manual curation for gene models, an important resource in their own right but especially for species which are due to acquire a genome project using Next Generation Sequencing.</p
Comparative Genomics of the Apicomplexan Parasites Toxoplasma gondii and Neospora caninum: Coccidia Differing in Host Range and Transmission Strategy
Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species
Clinical associations and potential novel antigenic targets of autoantibodies directed against rods and rings in chronic hepatitis C infection
Functional impairment of systemic scleroderma patients with digital ulcerations: results from the DUO Registry
OBJECTIVES:
Digital ulcers (DUs) are frequent manifestations of systemic scleroderma (SSc). This study assessed functional limitations due to DUs among patients enrolled in the Digital Ulcer Outcome (DUO) Registry, an international, multicentre, observational registry of SSc patients with DU disease.
METHODS:
Patients completed at enrolment a DU-specific functional assessment questionnaire with a 1-month recall period, measuring impairment in work and daily activities, and hours of help needed from others. Physician-reported clinical parameters were used to describe the population. For patients who completed at least part of the questionnaire, descriptive analyses were performed for overall results, and stratified by number of DUs at enrolment.
RESULTS:
This study included 2327 patients who completed at least part of the questionnaire. For patients with 0, 1–2, and ≥3 DUs at enrolment, mean overall work impairment during the prior month among employed/self-employed patients was 28%, 42%, and 48%, respectively. Across all included patients, ability to perform daily activities was impaired on average by 35%, 54%, and 63%, respectively. Patients required a mean of 2.0, 8.7, and 8.8 hours of paid help and 17.0, 35.9, and 63.7 hours of unpaid help, respectively, due to DUs in the prior month. Patients with DUs had more complications and medication use than patients with no DUs.
CONCLUSIONS:
With increasing number of DUs, SSc patients reported more impairment in work and daily activities and required more support from others
Purification of cross-linked RNA-protein complexes by phenol-toluol extraction
Recent methodological advances allowed the identification of an increasing number of RNA-binding proteins (RBPs) and their RNA-binding sites. Most of those methods rely, however, on capturing proteins associated to polyadenylated RNAs which neglects RBPs bound to non-adenylate RNA classes (tRNA, rRNA, pre-mRNA) as well as the vast majority of species that lack poly-A tails in their mRNAs (including all archea and bacteria). We have developed the Phenol Toluol extraction (PTex) protocol that does not rely on a specific RNA sequence or motif for isolation of cross-linked ribonucleoproteins (RNPs), but rather purifies them based entirely on their physicochemical properties. PTex captures RBPs that bind to RNA as short as 30 nt, RNPs directly from animal tissue and can be used to simplify complex workflows such as PAR-CLIP. Finally, we provide a global RNA-bound proteome of human HEK293 cells and the bacterium Salmonella Typhimurium
Contribution of genetic background, traditional risk factors, and HIV-related factors to coronary artery disease events in HIV-positive persons.
BACKGROUND: Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection.
METHODS: In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis. Using the Metabochip, we genotyped 1875 HIV-positive, white individuals enrolled in 24 HIV observational studies, including 571 participants with a first CAD event during the 9-year study period and 1304 controls matched on sex and cohort.
RESULTS: A genetic risk score built from 23 CAD-associated SNPs contributed significantly to CAD (P = 2.9 × 10(-4)). In the final multivariable model, participants with an unfavorable genetic background (top genetic score quartile) had a CAD odds ratio (OR) of 1.47 (95% confidence interval [CI], 1.05-2.04). This effect was similar to hypertension (OR = 1.36; 95% CI, 1.06-1.73), hypercholesterolemia (OR = 1.51; 95% CI, 1.16-1.96), diabetes (OR = 1.66; 95% CI, 1.10-2.49), ≥ 1 year lopinavir exposure (OR = 1.36; 95% CI, 1.06-1.73), and current abacavir treatment (OR = 1.56; 95% CI, 1.17-2.07). The effect of the genetic risk score was additive to the effect of nongenetic CAD risk factors, and did not change after adjustment for family history of CAD.
CONCLUSIONS: In the setting of HIV infection, the effect of an unfavorable genetic background was similar to traditional CAD risk factors and certain adverse antiretroviral exposures. Genetic testing may provide prognostic information complementary to family history of CAD
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