13 research outputs found

    Altering the distribution of Foxp3+ regulatory T cells results in tissue-specific inflammatory disease

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    CD4+Foxp3+ regulatory T cells (T reg) are essential for maintaining self-tolerance, but their functional mechanisms and sites of action in vivo are poorly defined. We examined the homing receptor expression and tissue distribution of T reg cells in the steady state and determined whether altering their distribution by removal of a single chemokine receptor impairs their ability to maintain tissue-specific peripheral tolerance. We found that T reg cells are distributed throughout all nonlymphoid tissues tested, and are particularly prevalent in the skin, where they express a unique CCR4+CD103hi phenotype. T reg cell expression of CCR4 and CD103 is induced by antigen-driven activation within subcutaneous lymph nodes, and accumulation of T reg cells in the skin and lung airways is impaired in the absence of CCR4 expression. Mice with a complete loss of CCR4 in the T reg cell compartment develop lymphocytic infiltration and severe inflammatory disease in the skin and lungs, accompanied by peripheral lymphadenopathy and increased differentiation of skin-tropic CD4+Foxp3+ T cells. Thus, selectively altering T reg cell distribution in vivo leads to the development of tissue-specific inflammatory disease

    Quantitative 18F-AV1451 Brain Tau PET Imaging in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease Patients

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    Recent developments of tau Positron Emission Tomography (PET) allows assessment of regional neurofibrillary tangles (NFTs) deposition in human brain. Among the tau PET molecular probes, 18F-AV1451 is characterized by high selectivity for pathologic tau aggregates over amyloid plaques, limited non-specific binding in white and gray matter, and confined off-target binding. The objectives of the study are (1) to quantitatively characterize regional brain tau deposition measured by 18F-AV1451 PET in cognitively normal older adults (CN), mild cognitive impairment (MCI), and AD participants; (2) to evaluate the correlations between cerebrospinal fluid (CSF) biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR); and (3) to evaluate the partial volume effects on 18F-AV1451 brain uptake.Methods: The study included total 115 participants (CN = 49, MCI = 58, and AD = 8) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed 18F-AV1451 PET images, structural MRIs, and demographic and clinical assessments were downloaded from the ADNI database. A reblurred Van Cittertiteration method was used for voxelwise partial volume correction (PVC) on PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. The parametric images of 18F-AV1451 SUVR relative to cerebellum were calculated. The ROI SUVR measurements from PVC and non-PVC SUVR images were compared. The correlation between ROI 18F-AV1451 SUVR and the measurements of MMSE, CSF total tau (t-tau), and phosphorylated tau (p-tau) were also assessed.Results:18F-AV1451 prominently specific binding was found in the amygdala, entorhinal cortex, parahippocampus, fusiform, posterior cingulate, temporal, parietal, and frontal brain regions. Most regional SUVRs showed significantly higher uptake of 18F-AV1451 in AD than MCI and CN participants. SUVRs of small regions like amygdala, entorhinal cortex and parahippocampus were statistically improved by PVC in all groups (p < 0.01). Although there was an increasing tendency of 18F-AV-1451 SUVRs in MCI group compared with CN group, no significant difference of 18F-AV1451 deposition was found between CN and MCI brains with or without PVC (p > 0.05). Declined MMSE score was observed with increasing 18F-AV1451 binding in amygdala, entorhinal cortex, parahippocampus, and fusiform. CSF p-tau was positively correlated with 18F-AV1451 deposition. PVC improved the results of 18F-AV-1451 tau deposition and correlation studies in small brain regions.Conclusion: The typical deposition of 18F-AV1451 tau PET imaging in AD brain was found in amygdala, entorhinal cortex, fusiform and parahippocampus, and these regions were strongly associated with cognitive impairment and CSF biomarkers. Although more deposition was observed in MCI group, the 18F-AV-1451 PET imaging could not differentiate the MCI patients from CN population. More tau deposition related to decreased MMSE score and increased level of CSF p-tau, especially in ROIs of amygdala, entorhinal cortex and parahippocampus. PVC did improve the results of tau deposition and correlation studies in small brain regions and suggest to be routinely used in 18F-AV1451 tau PET quantification

    Comparing the Effectiveness of Using Educational Booklet or Brief Video on Patients’ Knowledge, Perceptions and Willingness to Participate in Placebo-Controlled Clinical Trials

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    Background and Objectives: Limited knowledge about clinical trials can influence a patient’s willingness to participate in medical research. For placebo-controlled clinical trials, it is more difficult to recruit patients compared to clinical trials without a placebo arm. Thus, educating individuals about clinical trials and placebos can potentially improve their perceptions about clinical trials and might increase their willingness to enroll in them. The study objectives include: 1) To design educational interventions (a booklet and a video) to improve a patient’s knowledge of placebo controlled clinical trials. 2) To compare the impact of the educational interventions (booklet, video or both) on a patient’s knowledge of placebo-controlled clinical trials, perceptions (perceived benefits and perceived barriers) related to and their willingness to participate in placebo-controlled clinical trials. Methods: Patients from 3 different clinics (N=108) were randomly assigned to one of the following groups; booklet, video, both the booklet and video and control group. A paper based questionnaire was administered to measure patient’s knowledge, perception and their willingness to participate in placebo-controlled clinical trials. Results: Patients in the booklet group had a knowledge score of 9.59 (±0.74) out of 10 possible points. Patients in the video group scored 9.66 (±0.55) and patients in the booklet and video group scored 9.66 (±0.62) points, which was slightly a higher knowledge score compared to the booklet group. Patients in the control group had the lowest knowledge score of 8.03 (±1.84) points. There was a significant statistical difference in the knowledge score among the four groups (p 0.01). The educational materials used in the three interventional groups increased patient positive perceptions. There was no significant difference related to number of patients willing to participate in placebo-controlled trials among the different groups. Conclusions: The study results showed that the educational interventions were able to increase patient knowledge about placebo-controlled clinical trials significantly compared to the control group. Moreover, the educational interventions increased patient positive perceptions related to perceived benefits and reduced perceived barriers towards placebo-controlled clinical trials. The results of this study showed that patient knowledge was not a significant predictor of patient perceived barriers, benefits or their willingness to participate in clinical trials. These findings showed that a patient knowledge is not sufficient to increase participation in placebo-controlled clinical trials and that interventions need to go beyond educating knowledge to patients

    Total integrated performance excellence system (TIPES): A true north direction for a clinical trial support center

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    This paper presents the quality journey taken by a Federal organization over more than 20 years. These efforts have resulted in the implementation of a Total Integrated Performance Excellence System (TIPES) that combines key principles and practices of established quality systems. The Center has progressively integrated quality system frameworks including the Malcom Baldrige National Quality Award (MBNQA) Framework and Criteria for Performance Excellence, ISO 9001, and the Organizational Project Management Maturity Model (OPM3), as well as supplemental quality systems of ISO 15378 (packaging for medicinal products) and ISO 21500 (guide to project management) to systematically improve all areas of operations. These frameworks were selected for applicability to Center processes and systems, consistency and reinforcement of complimentary approaches, and international acceptance. External validations include the MBNQA, the highest quality award in the US, continued registration and conformance to ISO standards and guidelines, and multiple VA and state awards. With a focus on a holistic approach to quality involving processes, systems and personnel, this paper presents activities and lessons that were critical to building TIPES and establishing the quality environment for conducting clinical research in support of Veterans and national health care

    A protein engineered to bind uranyl selectively and with femtomolar affinity

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    Uranyl (UO22+), the predominant aerobic form of uranium, is present in the ocean at a concentration of similar to 3.2 parts per 10(9) (13.7 nM); however, the successful enrichment of uranyl from this vast resource has been limited by the high concentrations of metal ions of similar size and charge, which makes it difficult to design a binding motif that is selective for uranyl. Here we report the design and rational development of a uranyl-binding protein using a computational screening process in the initial search for potential uranyl-binding sites. The engineered protein is thermally stable and offers very high affinity and selectivity for uranyl with a K-d of 7.4 femtomolar (fM) and >10,000-fold selectivity over other metal ions. We also demonstrated that the uranyl-binding protein can repeatedly sequester 30-60% of the uranyl in synthetic sea water. The chemical strategy employed here may be applied to engineer other selective metal-binding proteins for biotechnology and remediation applications.Chemistry, MultidisciplinarySCI(E)[email protected]; [email protected]
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