113 research outputs found
Trends and correlates of HIV-1 resistance among subjects failing an antiretroviral treatment over the 2003-2012 decade in Italy
BACKGROUND:
Despite a substantial reduction in virological failures following introduction of new potent antiretroviral therapies in the latest years, drug resistance remains a limitation for the control of HIV-1 infection. We evaluated trends and correlates of resistance in treatment failing patients in a comprehensive database over a time period of relevant changes in prescription attitudes and treatment guidelines.
METHODS:
We analyzed 6,796 HIV-1 pol sequences from 49 centres stored in the Italian ARCA database during the 2003-2012 period. Patients (n = 5,246) with viremia > 200 copies/mL received a genotypic test while on treatment. Mutations were identified from IAS-USA 2013 tables. Class resistance was evaluated according to antiretroviral regimens in use at failure. Time trends and correlates of resistance were analyzed by Cochran-Armitage test and logistic regression models.
RESULTS:
The use of NRTI backbone regimens slightly decreased from 99.7% in 2003-2004 to 97.4% in 2010-2012. NNRTI-based combinations dropped from 46.7% to 24.1%. PI-containing regimens rose from 56.6% to 81.7%, with an increase of boosted PI from 36.5% to 68.9% overtime. In the same reference periods, Resistance to NRTIs, NNRTIs and PIs declined from 79.1% to 40.8%, from 77.8% to 53.8% and from 59.8% to 18.9%, respectively (p < .0001 for all comparisons). Dual NRTI + NNRTI and NRTI + PI resistance decreased from 56.4% to 33.3% and from 36.1% to 10.5%, respectively. Reduced risk of resistance over time periods was confirmed by a multivariate analysis.
CONCLUSIONS:
Mutations associated with NRTIs, NNRTIs and PIs at treatment failure declined overtime regardless of specific class combinations and epidemiological characteristics of treated population. This is likely due to the improvement of HIV treatment, including both last generation drug combinations and prescription guidelines
TGFβ pathway limits dedifferentiation following WNT and MAPK pathway activation to suppress intestinal tumourigenesis
Recent studies have suggested increased plasticity of differentiated cells within the intestine to act both as intestinal stem cells (ISCs) and tumour-initiating cells. However, little is known of the processes that regulate this plasticity. Our previous work has shown that activating mutations of Kras or the NF-κB pathway can drive dedifferentiation of intestinal cells lacking Apc. To investigate this process further, we profiled both cells undergoing dedifferentiation in vitro and tumours generated from these cells in vivo by gene expression analysis. Remarkably, no clear differences were observed in the tumours; however, during dedifferentiation in vitro we found a marked upregulation of TGFβ signalling, a pathway commonly mutated in colorectal cancer (CRC). Genetic inactivation of TGFβ type 1 receptor (Tgfbr1/Alk5) enhanced the ability of KrasG12D/+ mutation to drive dedifferentiation and markedly accelerated tumourigenesis. Mechanistically this is associated with a marked activation of MAPK signalling. Tumourigenesis from differentiated compartments is potently inhibited by MEK inhibition. Taken together, we show that tumours arising in differentiated compartments will be exposed to different suppressive signals, for example, TGFβ and blockade of these makes tumourigenesis more efficient from this compartment
Tephrochronology
Tephrochronology is the use of primary, characterized tephras or cryptotephras as chronostratigraphic marker beds to connect and synchronize geological, paleoenvironmental, or archaeological sequences or events, or soils/paleosols, and, uniquely, to transfer relative or numerical ages or dates to them using stratigraphic and age information together with mineralogical and geochemical compositional data, especially from individual glass-shard analyses, obtained for the tephra/cryptotephra deposits. To function as an age-equivalent correlation and chronostratigraphic dating tool, tephrochronology may be undertaken in three steps: (i) mapping and describing tephras and determining their stratigraphic relationships, (ii) characterizing tephras or cryptotephras in the laboratory, and (iii) dating them using a wide range of geochronological methods. Tephrochronology is also an important tool in volcanology, informing studies on volcanic petrology, volcano eruption histories and hazards, and volcano-climate forcing. Although limitations and challenges remain, multidisciplinary applications of tephrochronology continue to grow markedly
Nanobodies restore stability to cancer-associated mutants of tumor suppressor protein p16INK4a
\ua9 2025 The Author(s)We describe the generation and characterization of camelid single-domain antibodies (nanobodies) raised against tumor suppressor protein p16INK4a (p16). p16 is a cell cycle regulator that inhibits cyclin-dependent kinases CDK4 and CDK6 and is inactivated in sporadic and familial cancers. The majority of p16 missense mutations cause loss of function by destabilizing the protein\u27s structure. We identify nanobodies that bind p16 with nanomolar affinities and restore the stability of many different cancer-associated p16 mutations located at sites throughout the protein. The crystal structure of a nanobody-p16 complex reveals that the nanobody binds to the opposite face of p16 to the CDK-binding interface permitting formation of a ternary complex. We confirm that nanobodies bind to p16 in a cellular setting and do not preclude p16 binding to CDK6 and its ability to induce cell-cycle arrest. These findings indicate that nanobodies merit testing as pharmacological chaperones for p16 reactivation in the cell
The effectiveness of lunchbox interventions on improving the foods and beverages packed and consumed by children at centre-based care or school: a systematic review and meta-analysis
Objective: To assess the effectiveness of lunchbox interventions aiming to improve the foods and beverages packed and consumed by children at centre-based care or school; and subsequent impact on children’s adiposity.
Methods: Systematic search of nine databases for controlled trials published in English between 1995-January 2017. Where appropriate, data were pooled in a random effects meta-analysis.
Results: Of the 1601 articles identified, ten studies (centre-based care n = 4, school n = 6) were included of which eight were RCTs. The impact of interventions on the packing of discretionary foods, sugar-sweetened drinks and other core foods was inconsistent. Meta-analysis of four RCTs trials found a moderate increase in provision of vegetables (SMD = 0.40 95% CI 0.16 to 0.64, p = 0.001, I2 = 82%; equivalent to a mean difference of 0.28 serves) but not fruit. Four studies reported impact on children’s dietary intake, one reported no significant effect on consumption of discretionary foods, one reported improvements in the consumption of sugar-sweetened drinks and water, and two reported improvements in consumption of vegetables and fruit. Two studies, that were broader obesity prevention interventions, reported no significant impact on adiposity.
Conclusions: There is some evidence that lunchbox interventions are effective in improving the packing of vegetables in children’s lunchboxes, however more robust research is required to determine the impact on children’s dietary intake and adiposity.
Trial registration: PROSPERO 2016: CRD4201603564
The NIH-NIAID Schistosomiasis Resource Center
A bench scientist studying schistosomiasis must make a large commitment to maintain the parasite's life cycle, which necessarily involves a mammalian (definitive) host and the appropriate species of snail (intermediate host). This is often a difficult and expensive commitment to make, especially in the face of ever-tightening funds for tropical disease research. In addition to funding concerns, investigators usually face additional problems in the allocation of sufficient lab space to this effort (especially for snail rearing) and the limited availability of personnel experienced with life cycle upkeep. These problems can be especially daunting for the new investigator entering the field. Over 40 years ago, the National Institutes of Health–National Institute of Allergy and Infectious Diseases (NIH-NIAID) had the foresight to establish a resource from which investigators could obtain various schistosome life stages without having to expend the effort and funds necessary to maintain the entire life cycle on their own. This centralized resource translated into cost savings to both NIH-NIAID and to principal investigators by freeing up personnel costs on grants and allowing investigators to divert more funds to targeted research goals. Many investigators, especially those new to the field of tropical medicine, are only vaguely, if at all, aware of the scope of materials and support provided by this resource. This review is intended to help remedy that situation. Following a short history of the contract, we will give a brief description of the schistosome species provided, provide an estimate of the impact the resource has had on the research community, and describe some new additions and potential benefits the resource center might have for the ever-changing research interests of investigators
Designing and undertaking randomised implementation trials: guide for researchers
Implementation science is the study of methods to promote the systematic uptake of evidence based interventions into practice and policy to improve health. Despite the need for high quality evidence from implementation research, randomised trials of implementation strategies often have serious limitations. These limitations include high risks of bias, limited use of theory, a lack of standard terminology to describe implementation strategies, narrowly focused implementation outcomes, and poor reporting. This paper aims to improve the evidence base in implementation science by providing guidance on the development, conduct, and reporting of randomised trials of implementation strategies. Established randomised trial methods from seminal texts and recent developments in implementation science were consolidated by an international group of researchers, health policy makers, and practitioners. This article provides guidance on the key components of randomised trials of implementation strategies, including articulation of trial aims, trial recruitment and retention strategies, randomised design selection, use of implementation science theory and frameworks, measures, sample size calculations, ethical review, and trial reporting. It also focuses on topics requiring special consideration or adaptation for implementation trials. We propose this guide as a resource for researchers, healthcare and public health policy makers or practitioners, research funders, and journal editors with the goal of advancing rigorous conduct and reporting of randomised trials of implementation strategies
Adherence to Antiretroviral Treatment and Correlation with Risk of Hospitalization among Commercially Insured HIV Patients in the United States
Purpose: A lower daily pill burden may improve adherence to antiretroviral treatment (ART) and clinical outcomes in patients with human immunodeficiency virus (HIV). This study assessed differences in adherence using the number of pills taken per day, and evaluated how adherence correlated with hospitalization. Methodology: Commercially insured patients in the LifeLink database with an HIV diagnosis (International Classification of Diseases, 9th Revision, Clinical Modification code 042.xx) between 6/1/2006 and 12/31/2008 and receipt of a complete ART regimen were selected for inclusion. Patients were grouped according to their daily pill count and remained on ART for at least 60 days. Outcomes included adherence and rates of hospitalization. Adherence was measured as the proportion of days between the start and end of the regimen in which the patient maintained supply of all initiated ART components. Logistic regressions assessed the relationship between pills per day, adherence, and hospitalization, controlling for demographics, comorbidities, and ART-naïve (vs. experienced) status. Results: 7,073 patients met the study inclusion criteria, and 33.4%, 5.8%, and 60.8 % received an ART regimen comprising one, two, or three or more pills per day, respectively. Regression analysis showed patients receiving a single pill per day were significantly more likely to reach a 95 % adherence threshold versus patients receiving three or more pills per day (odds ratio [OR] = 1.59; P,0.001). Regardless of the number of pills received per day, patients were over 40 % less likely to have
A novel approach to identifying patterns of human invasion-inhibitory antibodies guides the design of malaria vaccines incorporating polymorphic antigens
Incidence and Reproduction Numbers of Pertussis: Estimates from Serological and Social Contact Data in Five European Countries
Analyses of serological and social contact data from several European countries by Miriam Kretzschmar and colleagues show that vaccination against pertussis has shifted the burden of infection from children to adolescents and adults
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