5,782 research outputs found

    Immunoglobulin Gamma Subclasses and Corresponding Fc Receptors in Rhesus Macaques: Genetic Characterization and Engineering of Recombinant Molecules

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    Rhesus macaques represent a valuable model in biomedical research and in development of vaccines and therapeutics. Due to the lack of reagents, the general properties of IgG and corresponding cellular receptors (FcγR) in this species are poorly characterized. We engineered recombinant IgGs containing each of the four rhesus macaque heavy constant region (CH) subclasses. To define FcγRs that mediate IgGs, we identified and characterized three FcγR classes, and generated recombinant cDNA constructs. cDNA IgH constructs were created by fusing – by sequence overlap extension PCRs – a gene segment encoding the murine variable heavy domain specific for the hapten NIP, an established specificity system for assessing antibody effector functions, with rhesus macaque CH fragments. The complete IgH constructs were transfected into J558L cells, a murine IgH-lost myeloma cell line expressing anti-NIP light chain. Secretion of engineered IgGs was determined by ELISAs using NIP-BSA and anti-monkey IgG-specific antibodies. Molecular cloning methods were applied to identify and clone FcγR genes, and recombinant FcγR cDNA constructs were created by the recombinant DNA method. Four engineered IgH cDNA constructs were successfully created. Recombinant IgGs, in the intact Ig form and retaining the original anti-NIP specificity, were successfully produced. Compared to those in humans, FcγRs in rhesus macaques share high homology, yet also feature a relatively high level of intra-species polymorphism and possess different N-linked glycosylation patterns. FcγR constructs and expression vectors were successfully generated. The chimeric recombinant IgGs are powerful tools for defining IgG functional properties and studying CH structure/function relationship. These molecules can also be used as immunogens for generation of antibodies capable of unequivocally detecting individual IgG subclasses. The findings on FcγRs validate rhesus macaques as a model for studying antibody responses, and underscore the need to take into account of the genetic heterogeneity. The FcγR constructs and vectors serve as a tool for further studies of IgG/FcγR interactions. We also reported here our findings from a separate study that the main female hormone, 17β-estradiol, is capable of restoring antibody responses to an influenza vaccine in a postmenopausal mouse model, suggesting that immunogenicity and efficacy of influenza vaccines should be evaluated in postmenopausal women

    Course Goals and Feedback Workflows: Examining Instructors\u27 Pedagogy in Professional Communication Service Courses

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    In Professional and Technical Communication (PTC), feedback has not been studied in proportion to its importance, particularly in service, or introductory, courses. Feedback is a form of assessment; therefore, an empirical study of instructor feedback requires attention to PTC instructors’ pedagogical goals and learning outcomes. This research asked and answered three questions about 1. Instructors’ pedagogical goals and learning outcomes for their PTC service courses, 2. Instructors’ approaches to giving feedback on students’ resumes and cover letters, and 3. The extent to which instructors’ pedagogical goals and feedback aligned. This research contributes data-driven findings on instructor feedback within PTC service courses, implications about how instructors’ training and theoretical backgrounds affect their pedagogy, and information about how instructors’ goals reflect PTC’s overarching goals. I interviewed 10 instructors and collected their service course syllabi, resume and cover letter assignment sheets, and instructors’ feedback on students’ de-identified resumes and cover letters. For analysis, I coded the data using a coding scheme that emerged from the data and from Miller’s genre as social action. When instructors spoke about their pedagogical goals, they most often discussed Neo-Aristotelian rhetoric and genre. In their syllabi learning outcomes, instructors framed rhetoric and critical thinking as most important. When giving feedback, half of the instructors gave formative feedback while half gave summative feedback. Summative feedback was faster; however, instructors who gave formative feedback generally received more polished writing. Four implications arose from the discrepancies between instructors’ pedagogical goals and their feedback-giving practices: 1. Instructors’ relationships with theory were informed by their graduate-level training and/or their workplace experience. 2. Instructors rarely discussed teaching information literacy and content-centric writing in their pedagogical goals; however, they gave ample feedback about issues of information, detail, and content on students’ resumes and cover letters. 3. Instructors’ labor conditions informed the perceived quality of their feedback and their adherence to their pedagogical goals. 4. Instructors often imported pedagogical methods from first-year composition into PTC service courses due to a lack of time or training. This study calls for further empirical research about instructors’ training experiences, instructor feedback, and field-wide goals for the PTC service course

    The Influence of Culture on HIV Disclosure Among Gay Asian Males

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    HIV-positive, Asian Pacific Islander (API) men who have sex with men (MSM) experience triple minority stigma including HIV, sexual orientation, and minority ethnicity. To date, there is no research that examines the influence of cultural factors, level of acculturation, social determinants of health, and other confounding variables (e.g., age, education, level of income, and length of time since diagnosis) on HIV-positive disclosure behaviors, attitudes, and intentions to casual sexual partners for API MSM. The theoretical framework for this study was based on Hofstede\u27s original cultural values and Triandis\u27s cultural dimensions. In this 2-phase, mixed methods, sequential explanatory study, 24 API MSM participants who are members of Fridae and other API organizations in the United States completed an anonymous online survey and 8 participants in Southern California completed in-depth semistructured phenomenological qualitative interviews. None of the regressions produced significant findings at the requested significance level (i.e., p \u3c 0.5). The findings from the 2 phases of the study were integrated to facilitate a deeper, richer, and better understanding and explanation of those results than either approach alone. This mixed methods study was unique because it addressed an under-researched and poorly understood population of API MSM. The findings from this study have implications for positive social change for practitioners to incorporate culturally sensitive counseling strategies and for policymakers to develop or modify existing HIV preventive health education and health promotion programs for HIV-positive API MSM to negotiate safer sex behaviors, improve well-being, provide informed choice, and protect life that would promote competent quality care

    Digital classrooms, public profiles

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    Framed by the larger questions of digital representation and course management systems, I examine how instructors perceive customized student profile on course management systems. For this exploratory study, I have surveyed 41 instructors and interviewed 9 instructors of English 150 and 250 in the English Department to examine how these instructors use both CMS and student profiles inside and outside of the classroom at Iowa State University. This study has found that instructors use their course management systems in various online ways: as online syllabi, as workshops for their students, as homework hubs, and as an extension of the classroom. Five main themes from this study include course management systems as a space, course management systems as a resource, boundaries between the physical and online classrooms, online identities through user profiles, and course management systems versus social media

    Study of process variables associated with manufacturing hermetically sealed nickel-cadium cells Quarterly report, 23 May - 23 Aug. 1970

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    Separator materials, ceramic to metal seals, cell plate polarization and impregnation processes, and plaque sintering data for study of variables in manufacture of nickel cadmium cell

    Delayed hepatic uptake of multi-phosphonic acid poly(ethylene glycol) coated iron oxide measured by real-time Magnetic Resonance Imaging

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    We report on the synthesis, characterization, stability and pharmacokinetics of novel iron based contrast agents for magnetic resonance imaging (MRI). Statistical copolymers combining multiple phosphonic acid groups and poly(ethylene glycol) (PEG) were synthesized and used as coating agents for 10 nm iron oxide nanocrystals. In vitro, protein corona and stability assays show that phosphonic acid PEG copolymers outperform all other coating types examined, including low molecular weight anionic ligands and polymers. In vivo, the particle pharmacokinetics is investigated by monitoring the MRI signal intensity from mouse liver, spleen and arteries as a function of the time, between one minute and seven days after injection. Iron oxide particles coated with multi-phosphonic acid PEG polymers are shown to have a blood circulation lifetime of 250 minutes, i.e. 10 to 50 times greater than that of recently published PEGylated probes and benchmarks. The clearance from the liver takes in average 2 to 3 days and is independent of the core size, coating and particle stability. By comparing identical core particles with different coatings, we are able to determine the optimum conditions for stealth MRI probes.Comment: 19 pages 8 figures, RSC Advances, 201
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