3,644 research outputs found

    A proteomic approach to identify endosomal cargoes controlling cancer invasiveness

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    We have previously shown that Rab17 - a small GTPase associated with epithelial polarity - is specifically suppressed by ERK2 signalling to promote an invasive phenotype. However, the mechanisms through which Rab17 loss permits invasiveness, and the endosomal cargoes that are responsible for mediating this are not known. Using quantitative mass spectrometry-based proteomics, we have found that knockdown of Rab17 leads to highly selective reduction in the cellular levels of a v-SNARE (Vamp8). Moreover, proteomics and immunofluorescence indicate that Vamp-8 is associated with Rab17 at late endosomes. Reduced levels of Vamp8 promote transition between ductal carcinoma in situ (DCIS) and a more invasive phenotype. We developed an unbiased proteomic approach to elucidate the complement of receptors that redistributes between endosomes and the plasma membrane, and have pin-pointed neuropilin-2 (NRP2) as a key pro-invasive cargo of Rab17/Vamp8-regulated trafficking. Indeed, reduced Rab17 or Vamp8 levels lead to increased mobilisation of NRP2-containing late endosomes and upregulated cell surface expression of NRP2. Finally, we show that NRP2 is required for the basement membrane disruption which accompanies transition between DCIS and a more invasive phenotype

    Preschool Participation and BMI at Kindergarten Entry: The Case for Early Behavioral Intervention

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    Preschool years (ages 3–5) are a critical period in growth and development. Emerging studies suggest that preschool attendance may be linked to future weight, and perhaps obesity. This study examined relationships between public preschool attendance, demographic variables, and weight at kindergarten entry. Participants included 2,400 children entering kindergarten in 2006. Height and weight were used to calculate a child's BMI category based on CDC norms. At kindergarten entry, 17% of participants were overweight, and 18% were obese. Children attending a public preschool were at an increased risk for overweight (OR = 1.06) and obesity (OR = 1.34) at kindergarten entry, χ2(2) = 6.81, P = .03 relative to children who did not attend preschool. No significant trends relationships between demographics and weight status were found, but demographic variables are summarized descriptively. Policy and clinical implications are provided

    Developing a Monitoring Framework to Estimate Wolf Distribution and Abundance in Southwest Alberta

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    Gray wolf (Canis lupus) populations are difficult to monitor because wolves can be elusive and occur in low densities.  Traditional radiotelemetry-based monitoring methods have limited application when turnover is high within the wolf population and resources to maintain long-term collaring programs are limited.  We worked collaboratively with Alberta Environmental Sustainable Resource Development between 2012 and 2014 to develop techniques for monitoring gray wolf populations in the absence of radiotelemetry in southwest Alberta.  We surveyed potential rendezvous sites and collected DNA samples from wolf scats for genetic analysis and surveyed hunters for wolf sightings made during the hunting seasons. We fit false-positive occupancy models to annual detection data derived from genetic results and hunter surveys with Program PRESENCE.  We found percent forest cover and human density positively influenced pack occupancy whereas detection probabilities varied by survey method, sampling effort, and sampling season.  The model predicted wolf pack occupancy well and distribution and abundance estimates were consistent with agency predictions.  While developing the monitoring framework, questions arose regarding pack turnover and population growth under widespread human harvest.  Previous studies have focused on population recovery following wolf control actions but little emphasis is put on populations that exist under regular harvest.  We will use genetic data to determine how immigration contributes to wolf population trends under a long-term harvest regime and tie this into pack occupancy through colonization and local extinction probabilities.  This will expand the application of our occupancy model and will further clarify how wolf populations respond to long-term regulated harvest

    Tuberculosis before and after the Black Death (1346 – 1353 CE) in the Hospital of St John the Evangelist in Cambridge, England

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    This article was published with Open Access under the Elsevier/Jisc Open Access agreement The authors would like to thank all of the members of the ‘After the Plague’ project, and the Cambridge Archaeological Unit for their help and support. We would also like to thank György Pálfi for organising the ICEPT-3 conference, at which the initial findings of this research were presented and for inviting us to contribute to this special issue. This research was funded by the Wellcome Trust (Award no 2000368/Z/15/Z) and St John's College, Cambridge.Peer reviewedPublisher PD

    Dynamic subcellular localization of isoforms of the folate pathway enzyme serine hydroxymethyltransferase (SHMT) through the erythrocytic cycle of Plasmodium falciparum

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    <p>Abstract</p> <p>Background</p> <p>The folate pathway enzyme serine hydroxymethyltransferase (SHMT) converts serine to glycine and 5,10-methylenetetrahydrofolate and is essential for the acquisition of one-carbon units for subsequent transfer reactions. 5,10-methylenetetrahydrofolate is used by thymidylate synthase to convert dUMP to dTMP for DNA synthesis. In <it>Plasmodium falciparum </it>an enzymatically functional SHMT (PfSHMTc) and a related, apparently inactive isoform (PfSHMTm) are found, encoded by different genes. Here, patterns of localization of the two isoforms during the parasite erythrocytic cycle are investigated.</p> <p>Methods</p> <p>Polyclonal antibodies were raised to PfSHMTc and PfSHMTm, and, together with specific markers for the mitochondrion and apicoplast, were employed in quantitative confocal fluorescence microscopy of blood-stage parasites.</p> <p>Results</p> <p>As well as the expected cytoplasmic occupancy of PfSHMTc during all stages, localization into the mitochondrion and apicoplast occurred in a stage-specific manner. Although early trophozoites lacked visible organellar PfSHMTc, a significant percentage of parasites showed such fluorescence during the mid-to-late trophozoite and schizont stages. In the case of the mitochondrion, the majority of parasites in these stages at any given time showed no marked PfSHMTc fluorescence, suggesting that its occupancy of this organelle is of limited duration. PfSHMTm showed a distinctly more pronounced mitochondrial location through most of the erythrocytic cycle and GFP-tagging of its N-terminal region confirmed the predicted presence of a mitochondrial signal sequence. Within the apicoplast, a majority of mitotic schizonts showed a marked concentration of PfSHMTc, whose localization in this organelle was less restricted than for the mitochondrion and persisted from the late trophozoite to the post-mitotic stages. PfSHMTm showed a broadly similar distribution across the cycle, but with a distinctive punctate accumulation towards the ends of elongating apicoplasts. In very late post-mitotic schizonts, both PfSHMTc and PfSHMTm were concentrated in the central region of the parasite that becomes the residual body on erythrocyte lysis and merozoite release.</p> <p>Conclusions</p> <p>Both PfSHMTc and PfSHMTm show dynamic, stage-dependent localization among the different compartments of the parasite and sequence analysis suggests they may also reversibly associate with each other, a factor that may be critical to folate cofactor function, given the apparent lack of enzymic activity of PfSHMTm.</p

    Immigration as a Compensatory Mechanism to Offset Harvest Mortality in Harvested Wolf Populations

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    In less than a decade the U.S. Northern Rocky Mountain gray wolf (Canis lupus) population has experienced large shifts in management practices, from federal protection under the Endangered Species Act to increasingly liberal hunting and trapping seasons in many portions of their range after delisting.  As a result, there is interest in how current wolf management practices will affect this population over time.  Recent research suggests wolf pup recruitment in central Idaho has declined since harvest was initiated, yet wolf densities appear stable in many regions of the state, suggesting other compensatory mechanisms are offsetting the effects of harvest mortality.  Our objective was to evaluate immigration as a compensatory mechanism that may offset the effects of harvest mortality and facilitate population persistence in a heavily harvested wolf population.  Using noninvasively sampled DNA we identified dispersers into two focal study areas in central Idaho prior to and after harvest was initiated.  We measured genetic relatedness within and among wolf packs using three different metrics to assess how immigration has changed with changing management practices.  Our results suggest that at current harvest rates immigration is not acting as a compensatory mechanism to offset the effects of harvest mortality.  Local dispersal may be unaffected by harvest pressure whereas harvest has negative effects on long-distance dispersal.  Our research can help managers consider the effects of immigration on local wolf populations when making harvest management decisions

    GPR55 deficiency is associated with increased adiposity and impaired insulin signaling in peripheral metabolic tissues

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    This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) and Diabetes UK. The authors declare no conflicts of interest. This article includes supplemental data. Please visit http://www.fasebj.org to obtain this information.Peer reviewedPublisher PD

    Understanding the social and community support experiences of sexual and gender minority individuals in 12-Step programs

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Gay and Lesbian Social Services on 25 Jan 2023, available at: http://www.tandfonline.com/10.1080/10538720.2023.2172759.Sexual and gender minority individuals (e.g., gay, bisexual, non-binary, transgender; SGMI) are 2-6 times as likely as cisgender heterosexual individuals to experience alcohol or other substance use disorders. SGMI participate in 12-Step groups, such as Alcoholics Anonymous (AA), at high rates. Though social support is an established mechanism through which 12-Step programs support reductions in substance use, little is known about SGMI’s experiences of the social support in 12-Step programs. This qualitative study aims to understand the experiences of social and community support among SGMI involved in 12-Step programs. This study employed thematic analysis to interpret open-ended responses from 302 SGMI who had participated in 12-Step programs. Data was from The PRIDE Study, a large, national, online. longitudinal, cohort study of SGMI. Two themes emerged about how SGMI experienced social and community support in 12-Step programs: beneficial connections and harmful environments. Beneficial connections included a sense of community, shared experiences, and skills provision. Harmful environments included marginalization, oppression, violence, and bullying. This study highlights the variability of experiences of SGMI participating in 12-Step programs. These findings suggest that many SGMI may benefit from 12-Step programs but may need support in coping with potential harms that can emerge through participation
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