21 research outputs found
Racial disparities in risks of stroke
To the Editor: The incidence of stroke in the United States has been decreasing as efforts have been made to control vascular risk factors. However, the extent to which modifications in changes in the risk of stroke have occurred in blacks as compared with whites has not been widely studied
Widening racial differences in risks for coronary heart disease
The incidence of coronary heart disease (CHD) has been declining in the United States, but these improvements appear to be lagging in blacks compared to whites. To understand racebased patterns in contributions to risk over time, we investigated temporal trends in the prevalence of major risk factors and their attributable hazards for CHD in a large sample of black and white adults living in 4 different communities and followed over the last two decades
A Single Visualization Technique for Displaying Multiple Metabolite-Phenotype Associations
To assist with management and interpretation of human metabolomics data, which are rapidly increasing in quantity and complexity, we need better visualization tools. Using a dataset of several hundred metabolite measures profiled in a cohort of similar to 1500 individuals sampled from a population-based community study, we performed association analyses with eight demographic and clinical traits and outcomes. We compared frequently used existing graphical approaches with a novel ` rain plot' approach to display the results of these analyses. The ` rain plot' combines features of a raindrop plot and a conventional heatmap to convey results of multiple association analyses. A rain plot can simultaneously indicate e ff ect size, directionality, and statistical significance of associations between metabolites and several traits. This approach enables visual comparison features of all metabolites examined with a given trait. The rain plot extends prior approaches and o ff ers complementary information for data interpretation. Additional work is needed in data visualizations for metabolomics to assist investigators in the process of understanding and convey large-scale analysis results e ff ectively, feasibly, and practically
Directed Non-targeted Mass Spectrometry and Chemical Networking for Discovery of Eicosanoids and Related Oxylipins
Eicosanoids and related oxylipins are critical, small bioactive mediators of human physiology and inflammation. While similar to 1,100 distinct species have been predicted to exist, to date, less than 150 of these molecules have been measured in humans, limiting our understanding of their role in human biology. Using a directed non-targeted mass spectrometry approach in conjunction with chemical networking of spectral fragmentation patterns, we find over 500 discrete chemical signals highly consistent with known and putative eicosanoids and related oxylipins in human plasma including 46 putative molecules not previously described. In plasma samples from 1,500 individuals, we find members of this expanded oxylipin library hold close association with markers of inflammation, as well as clinical characteristics linked with inflammation, including advancing age and obesity. These experimental and computational approaches enable discovery of new chemical entities and will shed important insight into the role of bioactive molecules in human health and disease
Reconfigurable self-assembly through chiral control of interfacial tension
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 481 (2012): 348–351, doi:10.1038/nature10769.From determining optical properties of simple molecular crystals to establishing preferred handedness in highly complex vertebrates, molecular chirality profoundly influences the structural, mechanical, and optical properties of both synthetic and biological matter at macroscopic lengthscales1,2. In soft materials such as amphiphilic lipids and liquid crystals, the competition between local chiral interactions and global constraints imposed by the geometry of the self-assembled structures leads to frustration and the assembly of unique materials3-6. An example of particular interest is smectic liquid crystals, where the 2D layered geometry cannot support twist, expelling chirality to the edges in a manner analogous to the expulsion of a magnetic field from superconductors7-10. Here, we demonstrate a previously unexplored consequence of this geometric frustration which leads to a new design principle for the assembly of chiral molecules. Using a model system of colloidal membranes11, we show that molecular chirality can control the interfacial tension, an important property of multi-component mixtures. This finding suggests an analogy between chiral twist which is expelled to the edge of 2D membranes, and amphiphilic surfactants which are expelled to oil-water interfaces12. Similar to surfactants, chiral control of interfacial tension drives the assembly of myriad polymorphic assemblages such as twisted ribbons with linear and circular topologies, starfish membranes, and double and triple helices. Tuning molecular chirality in situ enables dynamical control of line tension that powers polymorphic transitions between various chiral structures. These findings outline a general strategy for the assembly of reconfigurable chiral materials which can easily be moved, stretched, attached to one another, and transformed between multiple conformational states, thus enabling precise assembly and nano-sculpting of highly dynamical and designable materials with complex topologies.This work was supported by the National Science Foundation (NSF-MRSEC-0820492, NSF-DMR-0955776, NSF-MRI 0923057) and Petroleum Research Fund (ACS-PRF 50558-DNI7).2012-07-0
Diazoxide Promotes Oligodendrocyte Precursor Cell Proliferation and Myelination
Several clinical conditions are associated with white matter injury, including periventricular white matter injury (PWMI), which is a form of brain injury sustained by preterm infants. It has been suggested that white matter injury in this condition is due to altered oligodendrocyte (OL) development or death, resulting in OL loss and hypomyelination. At present drugs are not available that stimulate OL proliferation and promote myelination. Evidence suggests that depolarizing stimuli reduces OL proliferation and differentiation, whereas agents that hyperpolarize OLs stimulate OL proliferation and differentiation. Considering that the drug diazoxide activates K(ATP) channels to hyperpolarize cells, we tested if this compound could influence OL proliferation and myelination.Studies were performed using rat oligodendrocyte precursor cell (OPC) cultures, cerebellar slice cultures, and an in vivo model of PWMI in which newborn mice were exposed to chronic sublethal hypoxia (10% O(2)). We found that K(ATP) channel components Kir 6.1 and 6.2 and SUR2 were expressed in oligodendrocytes. Additionally, diazoxide potently stimulated OPC proliferation, as did other K(ATP) activators. Diazoxide also stimulated myelination in cerebellar slice cultures. We also found that diazoxide prevented hypomyelination and ventriculomegaly following chronic sublethal hypoxia.These results identify KATP channel components in OLs and show that diazoxide can stimulate OL proliferation in vitro. Importantly we find that diazoxide can promote myelination in vivo and prevent hypoxia-induced PWMI
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NT-3 weakly stimulates proliferation of adult rat O1−O4+ oligodendrocyte-lineage cells and increases oligodendrocyte myelination in vitro
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Mitogenic response of adult rat olfactory ensheathing glia to four growth factors
Olfactory ensheathing glia (EG) from adult rat proliferate slowly in vitro without added mitogens. The potential future use of EG in transplantation within the central nervous system to improve neural repair is dependent on identifying mitogens that will effectively expand EG without altering their phenotype. The mitogenic effects of heregulin (HRG), fibroblast growth factor 2 (FGF‐2), platelet‐derived growth factor BB (PDGF‐BB), insulin‐like growth factor 1 (IGF‐1), and forskolin (FSK) on cultured adult‐derived rat EG were monitored by tritiated‐thymidine labeling and p75 immunostaining. In serum‐containing medium, HRG, FGF‐2, PDGF‐BB, IGF‐1, and FSK were capable of stimulating EG proliferation, and the stimulation by these growth factors was potentiated by FSK. The combinations of HRG + FGF‐2, HRG + PDGF‐BB, HRG + IGF‐1, FGF‐2 + PDGF‐BB, and FGF‐2 + IGF‐1 all promoted EG proliferation in an additive manner. In serum‐free medium, HRG and FGF‐2 were mitogenic, but PDGF‐BB, IGF‐1 and FSK were not; however, FSK potentiated the stimulation by HRG and FGF‐2, and the combination of HRG + FGF‐2 promoted EG proliferation in an additive manner. This new information will be useful for the design of protocols to achieve sufficient numbers of adult‐derived EG for clinical purposes. This study also further establishes similarities between EG and Schwann cells. GLIA 33:334–342, 2001. © 2001 Wiley‐Liss, Inc
Health education and the control of intestinal worm infections in China : a new vision
The transmission of soil-transmitted helminths (STHs) is associated with poverty, poor hygiene behaviour, lack of clean water and inadequate waste disposal and sanitation. Periodic administration of benzimidazole drugs is the mainstay for global STH control but it does not prevent re-infection, and is unlikely to interrupt transmission as a stand-alone intervention.; We reported recently on the development and successful testing in Hunan province, PR China, of a health education package to prevent STH infections in Han Chinese primary school students. We have recently commenced a new trial of the package in the ethnically diverse Xishuangbanna autonomous prefecture in Yunnan province and the approach is also being tested in West Africa, with further expansion into the Philippines in 2015.; The work in China illustrates well the direct impact that health education can have in improving knowledge and awareness, and in changing hygiene behaviour. Further, it can provide insight into the public health outcomes of a multi-component integrated control program, where health education prevents re-infection and periodic drug treatment reduces prevalence and morbidity
Racial disparities in risks of stroke
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