1,797 research outputs found

    The Role of Phagocytes in Immunity to Candida albicans

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    Body clearance of fungi such as Candida albicans involves phagocytosis by fixed tissue macrophages as well as infiltrating monocytes and neutrophils. Through phagocytosis, the fungi are confined and killed by the oxidative and non-oxidative anti-microbial systems. These include oxygen derived reactive species, generated from the activation of the NADPH oxidase complex and granule constituents. These same mechanisms are responsible for the damage to hyphal forms of C. albicans. Complement promotes phagocytosis, through their interaction with a series of complement receptors including the recently described complement receptor immunoglobulin. However, it is also evident that under other conditions, the killing of yeast and hyphal forms can occur in a complement-independent manner. Phagocytosis and killing of Candida is enhanced by the cytokine network, such as tumour necrosis factor and interferon gamma. Patients with primary immunodeficiency diseases who have phagocytic deficiencies, such as those with defects in the NADPH oxidase complex are predisposed to fungal infections, providing evidence for the critical role of phagocytes in anti-fungal immunity. Secondary immunodeficiencies can arise as a result of treatment with anti-cancer or other immunosuppressive drugs. These agents may also predispose patients to fungal infections due to their ability to compromise the anti-microbial activity of phagocytes

    LET’s CONNECT community mentorship program for youths with peer social problems: Preliminary findings from a randomized effectiveness trial

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    This study examined the effectiveness of LET’s CONNECT (LC), a community mentorship program for youths who report peer social problems, which is based on a positive youth development framework. Participants were 218 youths (66.5% girls), aged 12 to 15 years, who were recruited from an urban medical emergency department and screened positive for bullying victimization, bullying perpetration, and/or low social connectedness. Youths were randomized to LC (n = 106) or the control condition (n = 112). Six‐month outcomes were assessed with self‐report measures of youth social connectedness, community connectedness, thwarted belongingness, depression, self‐esteem, and suicidal ideation. LC was associated with a significant increase in only one of these outcomes, social connectedness (effect size = 0.4). It was associated consistently with trend‐level positive changes for thwarted belongingness (decreased), depression (decreased), community connectedness, and self‐esteem (effect sizes = 0.2). There was no effect on suicidal ideation (effect size = 0.0), and although not a primary outcome, eight youths in the LC condition and seven youths in the control condition engaged in suicidal behavior between baseline and follow‐up. Although LC effect sizes are consistent with those from previous studies of community mentorship, there were multiple challenges to LC implementation that affected dosage and intervention fidelity, and that may account for the lack of stronger positive effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145529/1/jcop21979.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145529/2/jcop21979_am.pd

    Understanding Teamwork in the Provision of Cancer Care: Highlighting the Role of Trust

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    Team science research has indicated that trust is a critical variable of teamwork, contributing greatly to a team’s performance. Trust has long been examined in health care with research focusing on the development of trust by patients with their health care practitioners. Studies have indicated that trust is linked to patient satisfaction, adherence to treatment, continuity of care, and improved outcomes. We explore the construct of trust using a case example of a patient who received a surgical procedure for a precancerous polyp. We apply the principle of trust to the case as well as present the literature on trust and key definitions for understanding trust. Additionally, we apply the definitions presented to the specific case example by highlighting moments where trust is developed or violated. Lastly, we offer insights to health care practitioners on the development of trust in their own patient interactions to improve care

    Recruitment Strategies and the Retention of Obese Urban Racial/Ethnic Minority Adolescents in Clinical Trials: The FIT Families Project, Michigan, 2010–2014

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    Introduction The successful recruitment and retention of participants is integral to the translation of research findings. We examined the recruitment and retention rates of racial/ethnic minority adolescents at a center involved in the National Institutes of Health Obesity Research for Behavioral Intervention Trials (ORBIT) initiative by the 3 recruitment strategies used: clinic, informatics, and community. Methods During the 9-month study, 186 family dyads, each composed of an obese African American adolescent and a caregiver, enrolled in a 6-month weight-loss intervention, a sequential multiple assignment randomized trial. We compared recruitment and retention rates by recruitment strategy and examined whether recruitment strategy was related to dyad baseline characteristics. Results Of the 186 enrolled families, 110 (59.1%) were recruited through clinics, 53 (28.5%) through informatics, and 23 (12.4%) through community. Of those recruited through community, 40.4% enrolled in the study, compared with 32.7% through clinics and 8.2% through informatics. Active refusal rate was 3%. Of the 1,036 families identified for the study, 402 passively refused to participate: 290 (45.1%) identified through informatics, 17 (29.8%) through community, and 95 (28.3%) through clinics. Recruitment strategy was not related to the age of the adolescent, adolescent comorbidities, body mass index of the adolescent or caregiver, income or education of the caregiver, or retention rates at 3 months, 7 months, or 9 months. Study retention rate was 87.8%. Conclusion Using multiple recruitment strategies is beneficial when working with racial/ethnic minority adolescents, and each strategy can yield good retention. Research affiliated with health care systems would benefit from the continued specification, refinement, and dissemination of these strategies

    Tropical understory herbaceous community responds more strongly to hurricane disturbance than to experimental warming

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    Ecology and Evolution published by John Wiley & Sons Ltd. The effects of climate change on tropical forests may have global consequences due to the forests’ high biodiversity and major role in the global carbon cycle. In this study, we document the effects of experimental warming on the abundance and composition of a tropical forest floor herbaceous plant community in the Luquillo Experimental Forest, Puerto Rico. This study was conducted within Tropical Responses to Altered Climate Experiment (TRACE) plots, which use infrared heaters under free-air, open-field conditions, to warm understory vegetation and soils + 4°C above nearby control plots. Hurricanes Irma and María damaged the heating infrastructure in the second year of warming, therefore, the study included one pretreatment year, one year of warming, and one year of hurricane response with no warming. We measured percent leaf cover of individual herbaceous species, fern population dynamics, and species richness and diversity within three warmed and three control plots. Results showed that one year of experimental warming did not significantly affect the cover of individual herbaceous species, fern population dynamics, species richness, or species diversity. In contrast, herbaceous cover increased from 20% to 70%, bare ground decreased from 70% to 6%, and species composition shifted pre to posthurricane. The negligible effects of warming may have been due to the short duration of the warming treatment or an understory that is somewhat resistant to higher temperatures. Our results suggest that climate extremes that are predicted to increase with climate change, such as hurricanes and droughts, may cause more abrupt changes in tropical forest understories than longer-term sustained warming

    A global analysis of IFT-A function reveals specialization for transport of membrane-associated proteins into cilia

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    Intraflagellar transport (IFT), which is essential for the formation and function of cilia in most organisms, is the trafficking of IFT trains (i.e. assemblies of IFT particles) that carry cargo within the cilium. Defects in IFT cause several human diseases. IFT trains contain the complexes IFT-A and IFT-B. To dissect the functions of these complexes, we studied a Chlamydomonas mutant that is null for the IFT-A protein IFT140. The mutation had no effect on IFT-B but destabilized IFT-A, preventing flagella assembly. Therefore, IFT-A assembly requires IFT140. Truncated IFT140, which lacks the N-terminal WD repeats of the protein, partially rescued IFT and supported formation of half-length flagella that contained normal levels of IFT-B but greatly reduced amounts of IFT-A. The axonemes of these flagella had normal ultrastructure and, as investigated by SDS-PAGE, normal composition. However, composition of the flagellar \u27membrane+matrix\u27 was abnormal. Analysis of the latter fraction by mass spectrometry revealed decreases in small GTPases, lipid-anchored proteins and cell signaling proteins. Thus, IFT-A is specialized for the import of membrane-associated proteins. Abnormal levels of the latter are likely to account for the multiple phenotypes of patients with defects in IFT140. This article has an associated First Person interview with the first author of the paper

    Evaluation of a Diagnostic Reasoning Program (DxR): Exploring Student Perceptions and Addressing Faculty Concerns

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    Abstract: Clinical reasoning is essentially a problem-solving process, in which medical students must learn to gather and interpret data, generate hypotheses and make decisions. To develop skills in problem-solving it is argued that students need more tools, rather than more answers (Masys, 1989). DxR is a computerised case series, in which students use 'doctor tools' to investigate a patient problem. This report describes a pilot evaluation of DxR in fourth year medicine at the University of Sydney. It addresses faculty concerns regarding the program, explores student perceptions, and looks at the capacity of the program to stimulate and support the development of clinical reasoning skills. It finally discusses possibilities for using DxR to support learning in medicine. Reviewers: Stig Andersen (Virtual Centre for Health Informatics, Aalborg, DK), David Good (U. Cambridge), Timothy Koschmann (U. Colorado) Interactive elements: 'Details are provided for obtaining a DxR demonstration CD.' DxR is distributed by NOVARTIS, although the DxR cases described in this article are not the same as those listed in the Diagnosis category of their bookshop/website. A Macromedia Director demonstration of DxR can be obtained by contacting Tanaya Patel, Project Director, DxR Development Group ([email protected]). Alternatively, a demonstration CD, and complimentary catalogue of patient cases and price list can be obtained by calling 800-631-1181 (USA)
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