79 research outputs found
Optical High Content Nanoscopy of Epigenetic Marks Decodes Phenotypic Divergence in Stem Cells
While distinct stem cell phenotypes follow global changes in chromatin marks, single-cell chromatin technologies are unable to resolve or predict stem cell fates. We propose the first such use of optical high content nanoscopy of histone epigenetic marks (epi-marks) in stem cells to classify emergent cell states. By combining nanoscopy with epi-mark textural image informatics, we developed a novel approach, termed EDICTS (Epi-mark Descriptor Imaging of Cell Transitional States), to discern chromatin organizational changes, demarcate lineage gradations across a range of stem cell types and robustly track lineage restriction kinetics. We demonstrate the utility of EDICTS by predicting the lineage progression of stem cells cultured on biomaterial substrates with graded nanotopographies and mechanical stiffness, thus parsing the role of specific biophysical cues as sensitive epigenetic drivers. We also demonstrate the unique power of EDICTS to resolve cellular states based on epi-marks that cannot be detected via mass spectrometry based methods for quantifying the abundance of histone posttranslational modifications. Overall, EDICTS represents a powerful new methodology to predict single cell lineage decisions by integrating high content super-resolution nanoscopy and imaging informatics of the nuclear organization of epi-marks.National Institutes of Health (U.S.) (Grant GM110174
Co-culture of primary rat hepatocytes with rat liver epithelial cells enhances interleukin-6-induced acute-phase protein response
Three different primary rat hepatocyte culture methods were compared for their ability to allow the secretion of fibrinogen and albumin under basal and IL-6-stimulated conditions. These culture methods comprised the co-culture of hepatocytes with rat liver epithelial cells (CC-RLEC), a collagen type I sandwich culture (SW) and a conventional primary hepatocyte monolayer culture (ML). Basal albumin secretion was most stable over time in SW. Fibrinogen secretion was induced by IL-6 in all cell culture models. Compared with ML, CC-RLEC showed an almost three-fold higher fibrinogen secretion under both control and IL-6-stimulated conditions. Induction of fibrinogen release by IL-6 was lowest in SW. Albumin secretion was decreased after IL-6 stimulation in both ML and CC-RLEC. Thus, cells growing under the various primary hepatocyte cell culture techniques react differently to IL-6 stimulation with regard to acute-phase protein secretion. CC-RLEC is the preferred method for studying cytokine-mediated induction of acute-phase proteins, because of the pronounced stimulation of fibrinogen secretion upon IL-6 exposure under these conditions
Exposure assessment of process-related contaminants in food by biomarker monitoring
Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario’s and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment
Genome-wide characterization of intergenic polyadenylation sites redefines gene spaces in Arabidopsis thaliana
Knowledge of adverse drug reaction reporting in first year postgraduate doctors in a medical college
Prerna Upadhyaya,1 Vikas Seth,2 Vijay V Moghe,1 Monika Sharma,1 Mushtaq Ahmed11Department of Pharmacology, Mahatma Gandhi Medical College, Sitapura, Jaipur, Rajasthan, 2Department of Pharmacology, Hind Institute of Medical Sciences, Safedabad, Barabanki, Lucknow, Uttar Pradesh, IndiaIntroduction: Poor reporting of adverse drug reactions (ADRs) by doctors is a major hindrance to successful pharmacovigilance. The present study was designed to assess first-year residents’ knowledge of ADR reporting.Methods: First-year postgraduate doctors at a private medical college completed a structured questionnaire. The responses were analyzed by nonparametric methods.Results: All doctors were aware of the term “adverse drug reactions.” Fifty percent of the doctors reported being taught about ADR reporting during their undergraduate teaching, and 50% had witnessed ADRs in their internship training. Ten percent of patients suffering an ADR observed and reported by doctors required prolonged hospitalization for treatment as a result. Only 40% of interns reported the ADRs that they observed, while 60% did not report them. Twenty-eight percent reported ADRs to the head of the department, 8% to an ADR monitoring committee, and 4% to the pharmacovigilance center. Eighty-six percent of the doctors surveyed felt that a good knowledge of undergraduate clinical pharmacology therapeutics would have improved the level of ADR reporting.Conclusion: The knowledge of first-year doctors regarding ADR reporting is quite poor. There is a dire need to incorporate ADR reporting into undergraduate teaching, and to reinforce this during internships and periodically thereafter.Keywords: ADR reporting, pharmacovigilance, first-year postgraduate doctor
Bake hardening mechanism in steels
The steels used in modern automotive sector are faced with inherent compromise of formabilityfor desired increase in strength. During the last two and half decades. bake hardenable (BH) steels were developed to reduce the weight by decreasing the sheet thickness of autobody panels without deteriorating the strength properties. BH steels are characterized by excellent formability and low yield strength in delivery conditions from the plant and hence can be readily used for outer panels of automotive bodies. A sincere attempt is made to elucidate the core of contemporary mechanisms for bake hardening under different conditions of prestrain and temperature in two distinct stages. A worthwhile mention of some mathematical models is made to simulate the phenomena at atomic level and to reason some of the attributes of bake hardening mechanism. Finally, the ultimate increase in yield strength due to bake hardening process is abridged in an empirical relationship. The current paper is framed to unravel the 'Bake hardening mechanism. which serves as the grass root feature of the bake hardenable steels
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