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Phylodynamics of the HIV-1 CRF02_AG clade in Cameroon

Faria, Nuno Rodrigues; Suchard, Marc A; Abecasis, Ana; Sousa, J. D.; Ndembi, Nicaise; Camacho, R.J.; Vandamme, Anne-Mieke; Peeters, Martine; Lemey, Philippe
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
Evolutionary analyses have revealed an origin of pandemic HIV-1 group M in the Congo River basin in the first part of the XXth century, but the patterns of historical viral spread in or around its epicentre remain largely unexplored. Here, we combine epidemiologic and molecular sequence data to investigate the spatiotemporal patterns of the CRF02_AG clade. By explicitly integrating prevalence counts and genetic population size estimates we date the epidemic emergence of CRF02_AG at 1973.1 (1972.1, 1975.3 95% CI). To infer their phylogeographic signature at a regional scale, we analyze pol and env time-stamped sequence data from 8 countries using a Bayesian phylogeographic approach based on a discrete asymmetric model. Our data confirms a spatial origin of this clade in the Democratic Republic of Congo (DRC) and suggests that viral dissemination to Cameroon occurred at an early stage of the evolutionary history of CRF02_AG. We find considerable support for epidemiological linkage between neighbour countries. Compilation of ethnographic data suggests that well-supported viral migration was related with chance exportation events rather than by sustained human migratory flows. Finally, using sequence data from 15 locations in Cameroon...

Genetic Identification and Separation of Innate and Experience-Dependent Courtship Behaviors in Drosophila

Pan, Yufeng; Baker, Bruce S.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em 16/01/2014 Português
Wild-type D. melanogaster males innately possess the ability to perform a multi-step courtship ritual to conspecific females. The potential for this behavior is specified by the male-specific products of the fruitless (fruM) gene; males without fruM do not court females when held in isolation. We show that such fruM null males acquire the potential for courtship when grouped with other flies; they apparently learn to court flies with which they were grouped, irrespective of sex or species, and retain this behavior for at least a week. The male-specific product of the doublesex gene (dsxM) is necessary and sufficient for the acquisition of the potential for such experience-dependent courtship. These results reveal a process that builds, via dsxM and social experience, the potential for a more flexible sexual behavior, which could be evolutionarily conserved as dsx related genes that function in sexual development are found throughout the animal kingdom.

HPV vaccine coverage among men who have sex with men – National HIV Behavioral Surveillance System, United States, 2011

Meites, Elissa; Markowitz, Lauri E.; Paz-Bailey, Gabriela; Oster, Alexandra M.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
Men who have sex with men (MSM) are at high risk for disease associated with human papillomavirus (HPV). In late 2011, HPV vaccine was recommended for males through age 21 and MSM through age 26. Using data from the 2011 National HIV Behavioral Surveillance System, we assessed self-reported HPV vaccine uptake among MSM, using multivariate analysis to calculate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs). Among 3221 MSM aged 18–26, 157 (4.9%) reported ≥1 vaccine dose. Uptake was higher among men who visited a healthcare provider (aPR 2.3, CI: 1.2–4.2), disclosed same-sex sexual attraction/behavior to a provider (aPR 2.1, CI: 1.3–3.3), reported a positive HIV test (aPR 2.2, CI: 1.5–3.2), or received hepatitis vaccine (aPR 3.9, CI: 2.4–6.4). Of 3064 unvaccinated MSM, 2326 (75.9%) had visited a healthcare provider within 1 year. These national data on HPV vaccine uptake among MSM provide a baseline as vaccination recommendations are implemented.

Hairpin dsRNA does not trigger RNA interference in Candida albicans cells

Staab, Janet F.; White, Theodore C.; Marr, Kieren A.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
RNA interference/silencing mechanisms triggered by double-stranded RNA (dsRNA) have been described in many eukaryotes, including fungi. These mechanisms have in common small RNA molecules (siRNAs or microRNAs) originating from dsRNAs that, together with the effector protein Argonaute, mediate silencing. The genome of the fungal pathogen Candida albicans harbours a well-conserved Argonaute and a non-canonical Dicer, essential members of silencing pathways. Prototypical siRNAs are detected as members of the C. albicans transcriptome, which is potential evidence of RNA interference/silencing pathways in this organism. Surprisingly, expression of a dsRNA a hairpin ADE2 dsRNA molecule to interfere with the endogenous ADE2 mRNA did not result in down-regulation of the message or produce adenine auxotrophic strains. Cell free assays showed that the hairpin dsRNA was a substrate for the putative C. albicans Dicer, discounting the possibility that the nature of the dsRNA trigger affects silencing functionality. Our results suggested that unknown cellular events govern the functionality of siRNAs originating from transgenes in RNA interference/silencing pathways in C. albicans.

Seasonal variations in nocturnal changes in blood pressure between Ireland and Singapore

Wong, Lin Ho; Ting, Peter; Kerins, David
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português

REJUVENATION OF PERIOSTEAL CHONDROGENESIS USING LOCAL GROWTH FACTOR INJECTION

Reinholz, G.G.; Fitzsimmons, J.S.; Casper, M.; Ruesink, T.J.; Chung, H.W.; Schagemann, J.C.; O’Driscoll, S.W.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português

The Big Impact of Small Groups on College Drinking

Fitzpatrick, B.; Martinez, J.; Polidan, E.; Angelis, E.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
College drinking is a problem with severe academic, health, and safety consequences. The underlying social processes that lead to increased drinking activity are not well understood. Social Norms Theory is an approach to analysis and intervention based on the notion that students’ misperceptions about the drinking culture on campus lead to increases in alcohol use. In this paper we develop an agent-based simulation model, implemented in MATLAB, to examine college drinking. Students’ drinking behaviors are governed by their identity (and how others perceive it) as well as peer influences, as they interact in small groups over the course of a drinking event. Our simulation results provide some insight into the potential effectiveness of interventions such as social norms marketing campaigns.

Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline

Edwards, Ceiridwen J.; Suchard, Marc A.; Lemey, Philippe; Welch, John J.; Barnes, Ian; Fulton, Tara L.; Barnett, Ross; O’Connell, Tamsin C.; Coxon, Peter; Monaghan, Nigel; Valdiosera, Cristina E.; Lorenzen, Eline D.; Willerslev, Eske; Baryshnikov, Genna
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português

Breast Volume Asymmetry Value, Ratio, and Cancer Risk

Kayar, Ragıp; Çilengiroğlu, Özgül V.
Fonte: Libertas Academica Publicador: Libertas Academica
Tipo: Text
Publicado em 10/12/2015 Português

Predictors of Surgery Types after Neoadjuvant Therapy for Advanced Stage Breast Cancer: Analysis from Florida Population-Based Cancer Registry (1996–2009)

Al-Azhri, Jamila; Koru-Sengul, Tulay; Miao, Feng; Saclarides, Constantine; Byrne, Margaret M.; Avisar, Eli
Fonte: Libertas Academica Publicador: Libertas Academica
Tipo: Text
Publicado em 13/12/2015 Português

Integrated mass spectrometry–based analysis of plasma glycoproteins and their glycan modifications

Wang, Hong; Wong, Chee-Hong; Chin, Alice; Taguchi, Ayumu; Taylor, Allen; Hanash, Samir; Sekiya, Sadanori; Takahashi, Hidenori; Murase, Masaki; Kajihara, Shigeki; Iwamoto, Shinichi; Tanaka, Koichi
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
We present a protocol for the identification of glycosylated proteins in plasma followed by elucidation of their individual glycan compositions. The study of glycoproteins by mass spectrometry is usually based on cleavage of glycans followed by separate analysis of glycans and deglycosylated proteins, which limits the ability to derive glycan compositions for individual glycoproteins. The methodology described here consists of 2D HPLC fractionation of intact proteins and liquid chromatography–multistage tandem mass spectrometry (LC-MS/MSn) analysis of digested protein fractions. Protein samples are separated by 1D anion-exchange chromatography (AEX) with an eight-step salt elution. Protein fractions from each of the eight AEX elution steps are transferred onto the 2D reversed-phase column to further separate proteins. A digital ion trap mass spectrometer with a wide mass range is then used for LC-MS/MSn analysis of intact glycopeptides from the 2D HPLC fractions. Both peptide and oligosaccharide compositions are revealed by analysis of the ion fragmentation patterns of glycopeptides with an intact glycopeptide analysis pipeline.

Comparing Visual and Statistical Analysis in Single-Case Studies Using Published Studies

Harrington, Magadalena; Velicer, Wayne F.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em //2015 Português
Little is known about the extent to which interrupted time-series analysis (ITSA) can be applied to short, single-case study designs and whether those applications produce results consistent with visual analysis (VA). This paper examines the extent to which ITSA can be applied to single-case study designs and compares the results based on two methods: ITSA and VA, using papers published in the Journal of Applied Behavior Analysis in 2010. The study was made possible by the development of software called UnGraph® which facilitates the recovery of raw data from the graphs. ITSA was successfully applied to 94% of the examined graphs with the number of observations ranging from 8 to 136. Moderate to high lag 1 autocorrelations (> .50) were found for 46% of the data series. Effect sizes similar to group-level Cohen’s d were identified based on the tertile distribution. Effects ranging from 0.00 to 0.99 were classified as small, those ranging from 1.00 to 2.49 as medium, and large effect sizes were defined as 2.50 or greater. Comparison of the conclusions from VA and ITSA had a low level of agreement (Kappa = .14, accounting for the agreement expected by chance). The results demonstrate that ITSA can be broadly implemented in applied behavior analysis research. These two methods should be viewed as complimentary and used concurrently.

Wagner and Dollo: A Stochastic Duet by Composing Two Parsimonious Solos

Alekseyenko, Alexander V.; Lee, Christopher J.; Suchard, Marc A.
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em /10/2008 Português
New contributions toward generalizing evolutionary models expand greatly our ability to analyze complex evolutionary characters and advance phylogeny reconstruction. In this article, we extend the binary stochastic Dollo model to allow for multi-state characters. In doing so, we align previously incompatible Wagner and Dollo parsimony principles under a common probabilistic framework by embedding arbitrary continuous-time Markov chains into the binary stochastic Dollo model. This approach enables us to analyze character traits that exhibit both Dollo and Wagner characteristics throughout their evolutionary histories. Utilizing Bayesian inference, we apply our novel model to analyze intron conservation patterns and the evolution of alternatively spliced exons. The generalized framework we develop demonstrates potential in distinguishing between phylogenetic hypotheses and providing robust estimates of evolutionary rates. Moreover, for the two applications analyzed here, our framework is the first to provide an adequate stochastic process for the data. We discuss possible extensions to the framework from both theoretical and applied perspectives.

miRNAs As Diagnostic and Prognostic Biomarkers in Pancreatic Ductal Adenocarcinoma and Its Precursor Lesions: A Review

Alemar, Bárbara; Gregório, Cleandra; Ashton-Prolla, Patricia
Fonte: Libertas Academica Publicador: Libertas Academica
Tipo: Text
Publicado em 13/12/2015 Português
Pancreatic ductal adenocarcinoma (PDAC), a rare but lethal tumor, is difficult to diagnose without performing an invasive procedure. miRNAs are known to be deregulated in PDAC patients, and recent studies have shown that they can be used as diagnostic and prognostic of the disease. The detection of miRNAs in samples acquired through minimally or noninvasive procedures, such as serum, plasma, and saliva, can have a positive impact on the clinical management of these patients. This article is a comprehensive review of the major studies that have evaluated the expression of miRNAs as biomarkers in pancreatic cancer and its premalignant lesions.

Seagrass biofilm communities at a naturally CO2-rich vent

Hassenrück, Christiane; Hofmann, Laurie C; Bischof, Kai; Ramette, Alban
Fonte: John Wiley & Sons, Ltd Publicador: John Wiley & Sons, Ltd
Tipo: Text
Português
Seagrass meadows are a crucial component of tropical marine reef ecosystems. Seagrass plants are colonized by a multitude of epiphytic organisms that contribute to broadening the ecological role of seagrasses. To better understand how environmental changes like ocean acidification might affect epiphytic assemblages, the microbial community composition of the epiphytic biofilm of Enhalus acroides was investigated at a natural CO2 vent in Papua New Guinea using molecular fingerprinting and next-generation sequencing of 16S and 18S rRNA genes. Both bacterial and eukaryotic epiphytes formed distinct communities at the CO2-impacted site compared with the control site. This site-related CO2 effect was also visible in the succession pattern of microbial epiphytes. We further found an increased relative sequence abundance of bacterial types associated with coral diseases at the CO2-impacted site (Fusobacteria, Thalassomonas), whereas eukaryotes such as certain crustose coralline algae commonly related to healthy reefs were less diverse. These trends in the epiphytic community of E. acroides suggest a potential role of seagrasses as vectors of coral pathogens and may support previous predictions of a decrease in reef health and prevalence of diseases under future ocean acidification scenarios.

A novel keratin18 promoter that drives reporter gene expression in the intrahepatic and extrahepatic biliary system allows isolation of cell-type specific transcripts from zebrafish liver

Wilkins, Benjamin J.; Gong, Weilong; Pack, Michael
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
Heritable and acquired biliary disorders are an important cause of acute and chronic human liver disease. Biliary development and physiology have been studied extensively in rodent models and more recently, zebrafish have been used to uncover pathogenic mechanisms and potential therapies for these conditions. Here we report development of novel transgenic lines labeling the intrahepatic and extrahepatic biliary system of zebrafish larvae that can be used for lineage tracing and isolation of biliary-specific RNAs from mixed populations of liver cells. We show that GFP expression driven by a 4.4 kilobase promoter fragment from the zebrafish keratin18 (krt18) gene allows visualization of all components of the developing biliary system as early as 3 days post-fertilization. In addition, expression of a ribosomal fusion protein (EGFP-Rpl10a) in krt18:TRAP transgenic fish allows for enrichment of translated biliary cell mRNAs via translating ribosome affinity purification (TRAP). Future studies utilizing these reagents will enhance our understanding of the morphologic and molecular processes involved in biliary development and disease.

Age-associated changes in cardiovascular structure and function: a fertile milieu for future disease

Fleg, Jerome L.; Strait, James
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em /09/2012 Português
Important changes occur in the cardiovascular system with advancing age, even in apparently healthy individuals. Thickening and stiffening of the large arteries develop due to collagen and calcium deposition and loss of elastic fibers in the medial layer. These arterial changes cause systolic blood pressure to rise with age, while diastolic blood pressure generally declines after the sixth decade. In the left ventricle, modest concentric wall thickening occurs due to cellular hypertrophy, but cavity size does not change. Although left ventricular systolic function is preserved across the age span, early diastolic filling rate declines 30–50% between the third and ninth decades. Conversely, an age-associated increase in late diastolic filling due to atrial contraction preserves end-diastolic volume. Aerobic exercise capacity declines approximately 10% per decade in cross-sectional studies; in longitudinal studies, however, this decline is accelerated in the elderly. Reductions in peak heart rate and peripheral oxygen utilization but not stroke volume appear to mediate the age-associated decline in aerobic capacity. Deficits in both cardiac b-adrenergic receptor density and in the efficiency of postsynaptic b-adrenergic signaling contribute significantly to the reduced cardiovascular performance during exercise in older adults. Although these cardiovascular aging changes are considered “normative”...

Reiterative Use of the Notch Signal During Zebrafish Intrahepatic Biliary Development

Lorent, Kristin; Moore, John C; Siekmann, Arndt F; Lawson, Nathan; Pack, Michael
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em /03/2010 Português
The Notch signaling pathway regulates specification of zebrafish liver progenitor cells towards a biliary cell fate. Here, using staged administration of a pharmacological inhibitor of Notch receptor processing, we show that activation of the Notch pathway is also important for growth and expansion of the intrahepatic biliary network in zebrafish larvae. Biliary expansion is accompanied by extensive cell proliferation and active remodeling of the nascent ductal network, as revealed by time lapse imaging of living zebrafish larvae that express a Notch responsive fluorescent reporter transgene. Together, these data support a model in which the Notch signal functions reiteratively during biliary development; first to specific biliary cells and then to direct remodeling of the nascent biliary network. As the Notch pathway plays a comparable role during mammalian biliary development, including humans, these studies also indicate broad conservation of the molecular mechanisms directing biliary development in vertebrates.

A Unifying Genetic Model for Facioscapulohumeral Muscular Dystrophy

Lemmers, Richard J.L.F.; van der Vliet, Patrick J.; Klooster, Rinse; Sacconi, Sabrina; Camaño, Pilar; Dauwerse, Johannes G.; Snider, Lauren; Straasheijm, Kirsten R.; Jan van Ommen, Gert; Padberg, George W.; Miller, Daniel G.; Tapscott, Stephen J.; Tawil,
Fonte: PubMed Publicador: PubMed
Tipo: Text
Português
Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy in adults that is foremost characterized by progressive wasting of muscles in the upper body. FSHD is associated with contraction of D4Z4 macrosatellite repeats on chromosome 4q35 but this contraction is pathogenic only in certain “permissive” chromosomal backgrounds. Here we show that FSHD patients carry specific single nucleotide polymorphisms (SNPs) in the chromosomal region distal to the last D4Z4 repeat. This FSHD-predisposing configuration creates a canonical polyadenylation signal for transcripts derived from DUX4, a double homeobox gene of unknown function that straddles the last repeat unit and the adjacent sequence. Transfection studies revealed that DUX4 transcripts are efficiently polyadenylated and are more stable when expressed from permissive chromosomes. These findings suggest that FSHD arises through a toxic gain of function attributable to the stabilized distal DUX4 transcript.

Corrigendum to ‘Three-dimensional, soft neotissue arrays as high throughput platforms for the interrogation of engineered tissue environments’

Floren, Michael; Tan, Wei
Fonte: PubMed Publicador: PubMed
Tipo: Text
Publicado em /10/2015 Português