89 research outputs found

    Enhancement of mouse hematopoietic stem/progenitor cell function via transient gene delivery using integration-deficient lentiviral vectors

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    Integration-deficient lentiviruses (IdLVs) deliver genes effectively to tissues but are lost rapidly from dividing cells. This property can be harnessed to express transgenes transiently to manipulate cell biology. Here, we demonstrate the utility of short-term gene expression to improve functional potency of hematopoietic stem and progenitor cells (HSPCs) during transplantation by delivering HOXB4 and Angptl3 using IdLVs to enhance the engraftment of HSPCs. Constitutive overexpression of either of these genes is likely to be undesirable, but the transient nature of IdLVs reduces this risk and those associated with unsolicited gene expression in daughter cells. Transient expression led to increased multilineage hematopoietic engraftment in in vivo competitive repopulation assays without the side effects reported in constitutive overexpression models. Adult stem cell fate has not been programmed previously using IdLVs, but we demonstrate that these transient gene expression tools can produce clinically relevant alterations or be applied to investigate basic biology

    Late pregnancy vitamin D deficiency is associated with doubled odds of birth asphyxia and emergency caesarean section: A prospective cohort study

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    Objectives: The aim of this prospective cohort study was to investigate the associations between maternal vitamin D status in late pregnancy and emergency caesarean section (EMCS) and birth asphyxia, in a population based sample of women in Sweden. Methods: Pregnant women were recruited at the antenatal care in Sweden and 1832 women were included after exclusion of miscarriages, terminated pregnancies and missing data on vitamin D status. Mode of delivery was retrieved from medical records. EMCS was defined as caesarean section after onset of labour. Birth asphyxia was defined as either 5 min Apgar score < 7 or arterial umbilical cord pH < 7.1. Serum was sampled in the third trimester of pregnancy (T3) and 25-hydroxyvitamin D (25OHD) was analysed by liquid chromatography tandem mass spectrometry. Vitamin D deficiency was defined as 25OHD < 30 nmol/L, and associations were studied using logistic regression analysis and expressed as adjusted odds ratios (AOR). Results: In total, 141 (7.7%) women had an EMCS and 58 (3.2%) children were born with birth asphyxia. Vitamin D deficiency was only associated with higher odds of EMCS in women without epidural anaesthesia (AOR = 2.01, p = 0.044). Vitamin D deficiency was also associated with higher odds of birth asphyxia (AOR = 2.22, p = 0.044). Conclusions for Practice: In this Swedish prospective population-based cohort study, vitamin D deficiency in late pregnancy was associated with doubled odds of birth asphyxia and with EMCS in deliveries not aided by epidural anaesthesia. Prevention of vitamin D deficiency among pregnant women may reduce the incidence of EMCS and birth asphyxia. The mechanism behind the findings require further investigation

    Development of a core set of outcome measures for OAB treatment

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    © 2017, The Author(s). Introduction and hypothesis: Standardized measures enable the comparison of outcomes across providers and treatments giving valuable information for improving care quality and efficacy. The aim of this project was to define a minimum standard set of outcome measures and case-mix factors for evaluating the care of patients with overactive bladder (OAB). Methods: The International Consortium for Health Outcomes Measurement (ICHOM) convened an international working group (WG) of leading clinicians and patients to engage in a structured method for developing a core outcome set. Consensus was determined by a modified Delphi process, and discussions were supported by both literature review and patient input. Results: The standard set measures outcomes of care for adults seeking treatment for OAB, excluding residents of long-term care facilities. The WG focused on treatment outcomes identified as most important key outcome domains to patients: symptom burden and bother, physical functioning, emotional health, impact of symptoms and treatment on quality of life, and success of treatment. Demographic information and case-mix factors that may affect these outcomes were also included. Conclusions: The standardized outcome set for evaluating clinical care is appropriate for use by all health providers caring for patients with OAB, regardless of specialty or geographic location, and provides key data for quality improvement activities and research

    Layer-by-layer deposition of open-pore mesoporous TiO 2- Nafion® film electrodes

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    The formation of variable thickness TiO2 nanoparticle-Nafion® composite films with open pores is demonstrated via a layer-by-layer deposition process. Films of about 6 nm diameter TiO2 nanoparticles grow in the presence of Nafion® by “clustering” of nanoparticles into bigger aggregates, and the resulting hierarchical structure thickens with about 25 nm per deposition cycle. Film growth is characterized by electron microscopy, atomic force microscopy, and quartz crystal microbalance techniques. Simultaneous small-angle X-ray scattering and wide-angle X-ray scattering measurements for films before and after calcination demonstrate the effect of Nafion® binder causing aggregation. Electrochemical methods are employed to characterize the electrical conductivity and diffusivity of charge through the TiO2-Nafion® composite films. Characteristic electrochemical responses are observed for cationic redox systems (diheptylviologen2+/+, Ru(NH3)3+/2+6, and ferrocenylmethyl-trimethylammonium2+/+) immobilized into the TiO2-Nafion® nanocomposite material. Charge conduction is dependent on the type of redox system and is proposed to occur either via direct conduction through the TiO2 backbone (at sufficiently negative potentials) or via redox-center-based diffusion/electron hopping (at more positive potentials)

    Enhanced Migratory Waterfowl Distribution Modeling by Inclusion of Depth to Water Table Data

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    In addition to being used as a tool for ecological understanding, management and conservation of migratory waterfowl rely heavily on distribution models; yet these models have poor accuracy when compared to models of other bird groups. The goal of this study is to offer methods to enhance our ability to accurately model the spatial distributions of six migratory waterfowl species. This goal is accomplished by creating models based on species-specific annual cycles and introducing a depth to water table (DWT) data set. The DWT data set, a wetland proxy, is a simulated long-term measure of the point either at or below the surface where climate and geological/topographic water fluxes balance. For species occurrences, the USGS' banding bird data for six relatively common species was used. Distribution models are constructed using Random Forest and MaxEnt. Random Forest classification of habitat and non-habitat provided a measure of DWT variable importance, which indicated that DWT is as important, and often more important, to model accuracy as temperature, precipitation, elevation, and an alternative wetland measure. MaxEnt models that included DWT in addition to traditional predictor variables had a considerable increase in classification accuracy. Also, MaxEnt models created with DWT often had higher accuracy when compared with models created with an alternative measure of wetland habitat. By comparing maps of predicted probability of occurrence and response curves, it is possible to explore how different species respond to water table depth and how a species responds in different seasons. The results of this analysis also illustrate that, as expected, all waterfowl species are tightly affiliated with shallow water table habitat. However, this study illustrates that the intensity of affiliation is not constant between seasons for a species, nor is it consistent between species

    The role of copeptin as a diagnostic and prognostic biomarker for risk stratification in the emergency department

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    The hypothalamic-pituitary-adrenal axis is activated in response to stress. One of the activated hypothalamic hormones is arginine vasopressin, a hormone involved in hemodynamics and osmoregulation. Copeptin, the C-terminal part of the arginine vasopressin precursor peptide, is a sensitive and stable surrogate marker for arginine vasopressin release. Measurement of copeptin levels has been shown to be useful in a variety of clinical scenarios, particularly as a prognostic marker in patients with acute diseases such as lower respiratory tract infection, heart disease and stroke. The measurement of copeptin levels may provide crucial information for risk stratification in a variety of clinical situations. As such, the emergency department appears to be the ideal setting for its potential use. This review summarizes the recent progress towards determining the prognostic and diagnostic value of copeptin in the emergency department

    Time domains of the hypoxic ventilatory response in ectothermic vertebrates

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    Over a decade has passed since Powell et al. (Respir Physiol 112:123–134, 1998) described and defined the time domains of the hypoxic ventilatory response (HVR) in adult mammals. These time domains, however, have yet to receive much attention in other vertebrate groups. The initial, acute HVR of fish, amphibians and reptiles serves to minimize the imbalance between oxygen supply and demand. If the hypoxia is sustained, a suite of secondary adjustments occur giving rise to a more long-term balance (acclimatization) that allows the behaviors of normal life. These secondary responses can change over time as a function of the nature of the stimulus (the pattern and intensity of the hypoxic exposure). To add to the complexity of this process, hypoxia can also lead to metabolic suppression (the hypoxic metabolic response) and the magnitude of this is also time dependent. Unlike the original review of Powell et al. (Respir Physiol 112:123–134, 1998) that only considered the HVR in adult animals, we also consider relevant developmental time points where information is available. Finally, in amphibians and reptiles with incompletely divided hearts the magnitude of the ventilatory response will be modulated by hypoxia-induced changes in intra-cardiac shunting that also improve the match between O2 supply and demand, and these too change in a time-dependent fashion. While the current literature on this topic is reviewed here, it is noted that this area has received little attention. We attempt to redefine time domains in a more ‘holistic’ fashion that better accommodates research on ectotherms. If we are to distinguish between the genetic, developmental and environmental influences underlying the various ventilatory responses to hypoxia, however, we must design future experiments with time domains in mind

    Local staging of rectal cancer: the current role of MRI

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    With the advent of powerful gradient coil systems and high-resolution surface coils, magnetic resonance imaging (MRI) has recently extended its role in the staging of rectal cancer. MRI is superior to endorectal ultrasound, the most widely used staging modality in patients with rectal tumors, in that it visualizes not only the intestinal wall but also the surrounding pelvic anatomy. The crucial advantage of MRI is not that it enables exact T-staging but precise evaluation of the topographic relationship of a tumor to the mesorectal fascia. This fascia is the most important anatomic landmark for the feasibility of total mesorectal excision, which has evolved into the standard operative procedure for the resection of cancer located in the middle or lower third of the rectum. MRI is currently the only imaging modality that is highly accurate in predicting whether or not it is likely that a tumor-free margin can be achieved and thus provides important information for planning of an effective therapeutic strategy, especially in patients with advanced rectal cancer

    The HOXB4 Homeoprotein Promotes the Ex Vivo Enrichment of Functional Human Embryonic Stem Cell-Derived NK Cells

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    Human embryonic stem cells (hESCs) can be induced to differentiate into blood cells using either co-culture with stromal cells or following human embryoid bodies (hEBs) formation. It is now well established that the HOXB4 homeoprotein promotes the expansion of human adult hematopoietic stem cells (HSCs) but also myeloid and lymphoid progenitors. However, the role of HOXB4 in the development of hematopoietic cells from hESCs and particularly in the generation of hESC-derived NK-progenitor cells remains elusive. Based on the ability of HOXB4 to passively enter hematopoietic cells in a system that comprises a co-culture with the MS-5/SP-HOXB4 stromal cells, we provide evidence that HOXB4 delivery promotes the enrichment of hEB-derived precursors that could differentiate into fully mature and functional NK. These hEB-derived NK cells enriched by HOXB4 were characterized according to their CMH class I receptor expression, their cytotoxic arsenal, their expression of IFNγ and CD107a after stimulation and their lytic activity. Furthermore our study provides new insights into the gene expression profile of hEB-derived cells exposed to HOXB4 and shows the emergence of CD34+CD45RA+ precursors from hEBs indicating the lymphoid specification of hESC-derived hematopoietic precursors. Altogether, our results outline the effects of HOXB4 in combination with stromal cells in the development of NK cells from hESCs and suggest the potential use of HOXB4 protein for NK-cell enrichment from pluripotent stem cells
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