413 research outputs found

    Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)

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    Recommendations are given concerning the terminology of concepts and methods used in spectroscopy in analytical chemistry, covering nuclear magnetic resonance spectroscopy, atomic spectroscopy, and vibrational spectroscopy. © 2021 IUPAC and De Gruyter. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. For more information, please visit: http://creativecommons.org/licenses/by-nc-nd/4.0/ 2021

    Evaluation of the clinical value of bone metabolic parameters for the screening of osseous metastases compared to bone scintigraphy

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    BACKGROUND: Bone metastases are common in many types of cancer. As screening methods different imaging modalities are available. A new approach for the screening of osseous metastases represents the measurement of bone metabolic markers. Therefore aim of this study was to evaluate the usefulness of the determination of bone metabolic markers aminoterminal propeptide of type I procollagen (PINP, osteoblastic activity) and the carboxyterminal pyridinoline cross-linked telopeptide of type I collagen (ICTP, osteoclastic activity) for the detection of bone metastases associated with other malignancies. METHODS: 88 patients aged 21 – 82 years with malignant tumors were prospectively studied. The serum concentrations of PINP and ICTP were measured and compared to the results of bone scintigraphy, radiological bone series, CT, MRI and clinical follow-up. RESULTS: Osseous metastases were found in 21 patients. 19 of them were correctly identified by bone scintigraphy (sensitivity: 90%). For bone metabolic markers results were as follows: ICTP sensitivity: 71%, specificity: 42%; PINP sensitivity: 24%, specificity: 96%. CONCLUSIONS: As markers of bone metabolism PINP and ICTP showed low sensitivity and/or specificity for the detection of osseous metastases. The presented markers did not seem to be sufficient enough to identify patients with bone metastases or to replace established screening methods

    Antigen-specific CD4 cells assist CD8 T-effector cells in eliminating keratinocytes

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    Keratinocytes expressing tumor or viral antigens can be eliminated by antigen-primed CD8 cytotoxic T cells. CD4 T-helper cells help induction of CD8 cytotoxic T cells from naive precursors and generation of CD8 T-cell memory. In this study, we show, unexpectedly, that CD4 cells are also required to assist primed CD8 effector T cells in rejection of skin expressing human growth hormone, a neo-self-antigen, in keratinocytes. The requirement for CD4 cells can be substituted by CD40 costimulation. Rejection of skin expressing ovalbumin (OVA), a non-self-antigen, by primed CD8 cytotoxic T cells can in contrast occur without help from antigen-specific CD4 T cells. However, rejection of OVA expressing keratinocytes is helped by antigen-specific CD4 T cells if only low numbers of primed or naive OVA-specific CD8 T cells are available. Effective immunotherapy directed at antigens expressed in squamous cancer may therefore be facilitated by induction of tumor antigen-specific CD4 helper T cells, as well as cytotoxic CD8 T cells

    Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe

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    Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models

    CD4+ T Cell Effects on CD8+ T Cell Location Defined Using Bioluminescence

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    T lymphocytes of the CD8+ class are critical in delivering cytotoxic function and in controlling viral and intracellular infections. These cells are “helped” by T lymphocytes of the CD4+ class, which facilitate their activation, clonal expansion, full differentiation and the persistence of memory. In this study we investigated the impact of CD4+ T cells on the location of CD8+ T cells, using antibody-mediated CD4+ T cell depletion and imaging the antigen-driven redistribution of bioluminescent CD8+ T cells in living mice. We documented that CD4+ T cells influence the biodistribution of CD8+ T cells, favoring their localization to abdominal lymph nodes. Flow cytometric analysis revealed that this was associated with an increase in the expression of specific integrins. The presence of CD4+ T cells at the time of initial CD8+ T cell activation also influences their biodistribution in the memory phase. Based on these results, we propose the model that one of the functions of CD4+ T cell “help” is to program the homing potential of CD8+ T cells

    Nurses' experiences, expectations, and preferences for mind-body practices to reduce stress

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    BACKGROUND: Most research on the impact of mind-body training does not ask about participants\u27 baseline experience, expectations, or preferences for training. To better plan participant-centered mind-body intervention trials for nurses to reduce occupational stress, such descriptive information would be valuable. METHODS: We conducted an anonymous email survey between April and June, 2010 of North American nurses interested in mind-body training to reduce stress. The e-survey included: demographic characteristics, health conditions and stress levels; experiences with mind-body practices; expected health benefits; training preferences; and willingness to participate in future randomized controlled trials. RESULTS: Of the 342 respondents, 96% were women and 92% were Caucasian. Most (73%) reported one or more health conditions, notably anxiety (49%); back pain (41%); GI problems such as irritable bowel syndrome (34%); or depression (33%). Their median occupational stress level was 4 (0 = none; 5 = extreme stress). Nearly all (99%) reported already using one or more mind-body practices to reduce stress: intercessory prayer (86%), breath-focused meditation (49%), healing or therapeutic touch (39%), yoga/tai chi/qi gong (34%), or mindfulness-based meditation (18%). The greatest expected benefits were for greater spiritual well-being (56%); serenity, calm, or inner peace (54%); better mood (51%); more compassion (50%); or better sleep (42%). Most (65%) wanted additional training; convenience (74% essential or very important), was more important than the program\u27s reputation (49%) or scientific evidence about effectiveness (32%) in program selection. Most (65%) were willing to participate in a randomized trial of mind-body training; among these, most were willing to collect salivary cortisol (60%), or serum biomarkers (53%) to assess the impact of training. CONCLUSIONS: Most nurses interested in mind-body training already engage in such practices. They have greater expectations about spiritual and emotional than physical benefits, but are willing to participate in studies and to collect biomarker data. Recruitment may depend more on convenience than a program\u27s scientific basis or reputation. Knowledge of participants\u27 baseline experiences, expectations, and preferences helps inform future training and research on mind-body approaches to reduce stress

    Amplified B Lymphocyte CD40 Signaling Drives Regulatory B10 Cell Expansion in Mice

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    Aberrant CD40 ligand (CD154) expression occurs on both T cells and B cells in human lupus patients, which is suggested to enhance B cell CD40 signaling and play a role in disease pathogenesis. Transgenic mice expressing CD154 by their B cells (CD154(TG)) have an expanded spleen B cell pool and produce autoantibodies (autoAbs). CD22 deficient (CD22(-/-)) mice also produce autoAbs, and importantly, their B cells are hyper-proliferative following CD40 stimulation ex vivo. Combining these 2 genetic alterations in CD154(TG)CD22(-/-) mice was thereby predicted to intensify CD40 signaling and autoimmune disease due to autoreactive B cell expansion and/or activation.CD154(TG)CD22(-/-) mice were assessed for their humoral immune responses and for changes in their endogenous lymphocyte subsets. Remarkably, CD154(TG)CD22(-/-) mice were not autoimmune, but instead generated minimal IgG responses against both self and foreign antigens. This paucity in IgG isotype switching occurred despite an expanded spleen B cell pool, higher serum IgM levels, and augmented ex vivo B cell proliferation. Impaired IgG responses in CD154(TG)CD22(-/-) mice were explained by a 16-fold expansion of functional, mature IL-10-competent regulatory spleen B cells (B10 cells: 26.7×10(6)±6 in CD154(TG)CD22(-/-) mice; 1.7×10(6)±0.4 in wild type mice, p<0.01), and an 11-fold expansion of B10 cells combined with their ex vivo-matured progenitors (B10+B10pro cells: 66×10(6)±3 in CD154(TG)CD22(-/-) mice; 6.1×10(6)±2 in wild type mice, p<0.01) that represented 39% of all spleen B cells.These results demonstrate for the first time that the IL-10-producing B10 B cell subset has the capacity to suppress IgG humoral immune responses against both foreign and self antigens. Thereby, therapeutic agents that drive regulatory B10 cell expansion in vivo may inhibit pathogenic IgG autoAb production in humans

    Internet of Things for Sustainable Mining

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    The sustainable mining Internet of Things deals with the applications of IoT technology to the coupled needs of sustainable recovery of metals and a healthy environment for a thriving planet. In this chapter, the IoT architecture and technology is presented to support development of a digital mining platform emphasizing the exploration of rock–fluid–environment interactions to develop extraction methods with maximum economic benefit, while maintaining and preserving both water quantity and quality, soil, and, ultimately, human health. New perspectives are provided for IoT applications in developing new mineral resources, improved management of tailings, monitoring and mitigating contamination from mining. Moreover, tools to assess the environmental and social impacts of mining including the demands on dwindling freshwater resources. The cutting-edge technologies that could be leveraged to develop the state-of-the-art sustainable mining IoT paradigm are also discussed

    IL-2 Mediates CD4+ T Cell Help in the Breakdown of Memory-Like CD8+ T Cell Tolerance under Lymphopenic Conditions

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    Background: Lymphopenia results in the proliferation and differentiation of naïve T cells into memory-like cells in the apparent absence of antigenic stimulation. This response, at least in part due to a greater availability of cytokines, is thought to promote anti-self responses. Although potentially autoreactive memory-like CD8 + T cells generated in a lymphopenic environment are subject to the mechanisms of peripheral tolerance, they can induce autoimmunity in the presence of antigen-specific memory-like CD4 + T helper cells. Methodology/Principal Findings: Here, we studied the mechanisms underlying CD4 help under lymphopenic conditions in transgenic mice expressing a model antigen in the beta cells of the pancreas. Surprisingly, we found that the self-reactivity mediated by the cooperation of memory-like CD8 + and CD4 + T cells was not abrogated by CD40L blockade. In contrast, treatment with anti-IL-2 antibodies inhibited the onset of autoimmunity. IL-2 neutralization prevented the CD4-mediated differentiation of memory-like CD8 + T cells into pathogenic effectors in response to self-antigen cross-presentation. Furthermore, in the absence of helper cells, induction of IL-2 signaling by an IL-2 immune complex was sufficient to promote memory-like CD8 + T cell self-reactivity. Conclusions/Significance: IL-2 mediates the cooperation of memory-like CD4 + and CD8 + T cells in the breakdown of crosstolerance, resulting in effector cytotoxic T lymphocyte differentiation and the induction of autoimmune disease
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