179 research outputs found
Paper Session II-B - Evolution of Biomedical Payloads to Expand Human Presence in Space
Life sciences has always been an important part of the human space program. The effects of space flight on humans were monitored from the beginning and some research was conducted in the Gemini and Apollo programs. But it was only when a space station, Skylab, was available that we were able to perform in-depth medical experiments to examine the responses of humans to space flight. Since Skylab, flight research programs have been and still are progressing toward our goals of helping astronauts live in space for long periods of time and readapt to Earth\u27s gravity as rapidly as possible, and studying the response of living systems to microgravity.
The remaining Spacelab missions promise to build on the knowledge gained from previous missions to provide further understanding of physiologic changes occurring in and resulting from space flight. Investigation results and lessons learned from each of these missions will be used to influence future space shuttle missions and Space Station Freedom
Use of telescience for biomedical research during space flight
When the U.S. first embarked on a manned space flight program, NASA's use of medical telescience was focused on crew health monitoring. In recent years, medical telescience use has been expanded to include support of basic research in space medicine. It enables ground support personnel to assist on-board crews in the performance of experiments and improves the quality and quantity of data return. NASA is continuing to develop its telescience capabilities. Future plans include telemedicine that will enable physicians on Earth to support crewmembers during flight and telescience that will enable investigators at their home institutions to support and conduct in-flight medical research. NASA's use of telescience for crew safety and biomedical research from Project Mercury to the present is described and NASA's plans for the future are presented
Self-reported evaluation of competencies and attitudes by physicians-in-training before and after a single day legislative advocacy experience
BACKGROUND: Advocacy is increasingly being recognized as a core element of medical professionalism and efforts are underway to incorporate advocacy training into graduate and undergraduate medical school curricula. While limited data exist to quantify physician attitudes toward advocacy, even less has been done to assess the knowledge, skills, and attitudes of future physicians. The purpose of this study was to assess students’ experiences and attitudes toward legislative advocacy, cutting out using a convience sample. METHODS: A paper survey based on previously validated surveys was administered to a convenience sample of premedical and medical student participants attending a National Advocacy Day in Washington, DC, in March 2011, both before and after their advocacy experiences. Responses were anonymous and either categorical ( or ordinal, using a 5-point Likert scale. Data were analyzed statistically to evaluate demographics and compare changes in pre- and post-experience attitude and skills. RESULTS: Data from 108 pre-advocacy and 50 post-advocacy surveys were analyzed yielding a response rate of 46.3%. Following a single advocacy experience, subjects felt they were more likely to contact their legislators about healthcare issues (p = 0.03), to meet in person with their legislators (p < 0.01), and to advocate for populations' health needs (p = 0.04). Participants endorsed an increased perception of the role of a physician advocate extending beyond individual patients (p = 0.03). Participants disagreed with the statement that their formal curricula adequately covered legislative healthcare advocacy. Additionally, respondents indicated that they plan to engage in legislative advocacy activities in the future (p < 0.01). CONCLUSIONS: A one-time practical advocacy experience has a positive influence on students’ knowledge, skills and attitudes towards legislative advocacy. Practical experience is an important method of furthering medical education in advocacy and further research is necessary to assess its impact in a broader population
Healthcare Reform and the Next Generation: United States Medical Student Attitudes toward the Patient Protection and Affordable Care Act
CONTEXT: Over one year after passage of the Patient Protection and Affordable Care Act (PPACA), legislators, healthcare experts, physicians, and the general public continue to debate the implications of the law and its repeal. The PPACA will have a significant impact on future physicians, yet medical student perspectives on the legislation have not been well documented. OBJECTIVE: To evaluate medical students' understanding of and attitudes toward healthcare reform and the PPACA including issues of quality, access and cost. DESIGN, SETTING, AND PARTICIPANTS: An anonymous electronic survey was sent to medical students at 10 medical schools (total of 6982 students) between October-December 2010, with 1232 students responding and a response rate of 18%. MAIN OUTCOME MEASURES: Medical students' views and attitudes regarding the PPACA and related topics, measured with Likert scale and open response items. RESULTS: Of medical students surveyed, 94.8% agreed that the existing United States healthcare system needs to be reformed, 31.4% believed the PPACA will improve healthcare quality, while 20.9% disagreed and almost half (47.7%) were unsure if quality will be improved. Two thirds (67.6%) believed that the PPACA will increase access, 6.5% disagreed and the remaining 25.9% were unsure. With regard to containing healthcare costs, 45.4% of participants indicated that they are unsure if the provisions of the PPACA will do so. Overall, 80.1% of respondents indicated that they support the PPACA, and 78.3% also indicated that they did not feel that reform efforts had gone far enough. A majority of respondents (58.8%) opposed repeal of the PPACA, while 15.0% supported repeal, and 26.1% were undecided. CONCLUSION: The overwhelming majority of medical students recognized healthcare reform is needed and expressed support for the PPACA but echoed concerns about whether it will address issues of quality or cost containment
Single-cell analysis of human glioma and immune cells identifies S100A4 as an immunotherapy target.
A major rate-limiting step in developing more effective immunotherapies for GBM is our inadequate understanding of the cellular complexity and the molecular heterogeneity of immune infiltrates in gliomas. Here, we report an integrated analysis of 201,986 human glioma, immune, and other stromal cells at the single cell level. In doing so, we discover extensive spatial and molecular heterogeneity in immune infiltrates. We identify molecular signatures for nine distinct myeloid cell subtypes, of which five are independent prognostic indicators of glioma patient survival. Furthermore, we identify S100A4 as a regulator of immune suppressive T and myeloid cells in GBM and demonstrate that deleting S100a4 in non-cancer cells is sufficient to reprogram the immune landscape and significantly improve survival. This study provides insights into spatial, molecular, and functional heterogeneity of glioma and glioma-associated immune cells and demonstrates the utility of this dataset for discovering therapeutic targets for this poorly immunogenic cancer
Synthetic Cationic Helical Polypeptides for the Stimulation of Antitumour Innate Immune Pathways in Antigen-Presenting Cells
Intracellular DNA sensors regulate innate immunity and can provide a bridge to adaptive immunogenicity. However, the activation of the sensors in antigen-presenting cells (APCs) by natural agonists such as double-stranded DNAs or cyclic nucleotides is impeded by poor intracellular delivery, serum stability, enzymatic degradation and rapid systemic clearance. Here we show that the hydrophobicity, electrostatic charge and secondary conformation of helical polypeptides can be optimized to stimulate innate immune pathways via endoplasmic reticulum stress in APCs. One of the three polypeptides that we engineered activated two major intracellular DNA-sensing pathways (cGAS-STING (for cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes) and Toll-like receptor 9) preferentially in APCs by promoting the release of mitochondrial DNA, which led to the efficient priming of effector T cells. In syngeneic mouse models of locally advanced and metastatic breast cancers, the polypeptides led to potent DNA-sensor-mediated antitumour responses when intravenously given as monotherapy or with immune checkpoint inhibitors. The activation of multiple innate immune pathways via engineered cationic polypeptides may offer therapeutic advantages in the generation of antitumour immune responses
RAD18-mediated ubiquitination of PCNA activates the Fanconi anemia DNA repair network
The DNA damage–activated E3 ubiquitin ligase RAD18 promotes repair of interstrand DNA cross-links by ubiquitylating PCNA and recruiting FANCL to chromatin
Checkpoint Signaling, Base Excision Repair, and PARP Promote Survival of Colon Cancer Cells Treated with 5-Fluorodeoxyuridine but Not 5-Fluorouracil
The fluoropyrimidines 5-fluorouracil (5-FU) and FdUrd (5-fluorodeoxyuridine; floxuridine) are the backbone of chemotherapy regimens for colon cancer and other tumors. Despite their widespread use, it remains unclear how these agents kill tumor cells. Here, we have analyzed the checkpoint and DNA repair pathways that affect colon tumor responses to 5-FU and FdUrd. These studies demonstrate that both FdUrd and 5-FU activate the ATR and ATM checkpoint signaling pathways, indicating that they cause genotoxic damage. Notably, however, depletion of ATM or ATR does not sensitize colon cancer cells to 5-FU, whereas these checkpoint pathways promote the survival of cells treated with FdUrd, suggesting that FdUrd exerts cytotoxicity by disrupting DNA replication and/or inducing DNA damage, whereas 5-FU does not. We also found that disabling the base excision (BER) repair pathway by depleting XRCC1 or APE1 sensitized colon cancer cells to FdUrd but not 5-FU. Consistent with a role for the BER pathway, we show that small molecule poly(ADP-ribose) polymerase 1/2 (PARP) inhibitors, AZD2281 and ABT-888, remarkably sensitized both mismatch repair (MMR)-proficient and -deficient colon cancer cell lines to FdUrd but not to 5-FU. Taken together, these studies demonstrate that the roles of genotoxin-induced checkpoint signaling and DNA repair differ significantly for these agents and also suggest a novel approach to colon cancer therapy in which FdUrd is combined with a small molecule PARP inhibitor
Engineering a Tunable Micropattern-Array Assay To Sort Single Extracellular Vesicles and Particles To Detect RNA and Protein In Situ
The molecular heterogeneity of extracellular vesicles (EVs) and the co-isolation of physically similar particles, such as lipoproteins (LPs), confounds and limits the sensitivity of EV bulk biomarker characterization. Herein, we present a single-EV and particle (siEVP) protein and RNA assay (siEVPPRA) to simultaneously detect mRNAs, miRNAs, and proteins in subpopulations of EVs and LPs. The siEVPPRA immobilizes and sorts particles via positive immunoselection onto micropatterns and focuses biomolecular signals in situ. By detecting EVPs at a single-particle resolution, the siEVPPRA outperformed the sensitivities of bulk-analysis benchmark assays for RNA and protein. To assess the specificity of RNA detection in complex biofluids, EVs from various glioma cell lines were processed with small RNA sequencing, whereby two mRNAs and two miRNAs associated with glioblastoma multiforme (GBM) were chosen for cross-validation. Despite the presence of single-EV-LP co-isolates in serum, the siEVPPRA detected GBM-associated vesicular RNA profiles in GBM patient siEVPs. The siEVPPRA effectively examines intravesicular, intervesicular, and interparticle heterogeneity with diagnostic promise
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