1,845 research outputs found
Physical non-equivalence of the Jordan and Einstein frames
We show, considering a specific f(R)-gravity model, that the Jordan frame and
the Einstein frame are physically non-equivalent, although they are connected
by a conformal transformation which yields a mathematical equivalence. Since
all the calculations are performed analytically, this non-equivalence is shown
in an unambiguous way.Comment: 7 pages, 3 figure
Residual effects of esmirtazapine on actual driving performance: overall findings and an exploratory analysis into the role of CYP2D6 phenotype
INTRODUCTION: Esmirtazapine is evaluated as a novel drug for treatment of insomnia. PURPOSE: The present study was designed to assess residual effects of single and repeated doses of esmirtazapine 1.5 and 4.5 mg on actual driving in 32 healthy volunteers in a double-blind, placebo-controlled study. Treatment with single doses of zopiclone 7.5 mg was included as active control. METHODS: Treatments were administered in the evening. Driving performance was assessed in the morning, 11 h after drug intake, in a standardized on-the-road highway driving test. The primary study parameter was standard deviation of lateral position (SDLP), a measure of "weaving". All subjects were subjected to CYP2D6 phenotyping in order to distinguish poor metabolizers from extensive metabolizers of esmirtazapine. RESULTS: Overall, esmirtazapine 1.5 mg did not produce any clinically relevant change in SDLP after single and repeated dosing. Driving impairment, i.e., a rise in SDLP, did occur after a single-dose administration of esmirtazapine 4.5 mg but was resolved after repeated doses. Acute driving impairment was more pronounced after both doses of esmirtazapine in a select group of poor metabolizers (N = 7). A single-dose zopiclone 7.5 mg also increased SDLP as expected. CONCLUSION: It is concluded that single and repeated doses of 1.5 mg esmirtazapine are generally not associated with residual impairment. Single-dose administration of 4.5 mg esmirtazapine was associated with residual impairment that generally resolved after repeated administration. Exploratory analysis in a small group of poor CYP 2D6 metabolizers suggested that these subjects are more sensitive to the impairing effects of esmirtazapine on car driving
In vaginal fluid, bacteria associated with bacterial vaginosis can be suppressed with lactic acid but not hydrogen peroxide
<p>Abstract</p> <p>Background</p> <p>Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) produced by vaginal lactobacilli is generally believed to protect against bacteria associated with bacterial vaginosis (BV), and strains of lactobacilli that can produce H<sub>2</sub>O<sub>2 </sub>are being developed as vaginal probiotics. However, evidence that led to this belief was based in part on non-physiological conditions, antioxidant-free aerobic conditions selected to maximize both production and microbicidal activity of H<sub>2</sub>O<sub>2</sub>. Here we used conditions more like those <it>in vivo </it>to compare the effects of physiologically plausible concentrations of H<sub>2</sub>O<sub>2 </sub>and lactic acid on a broad range of BV-associated bacteria and vaginal lactobacilli.</p> <p>Methods</p> <p>Anaerobic cultures of seventeen species of BV-associated bacteria and four species of vaginal lactobacilli were exposed to H<sub>2</sub>O<sub>2</sub>, lactic acid, or acetic acid at pH 7.0 and pH 4.5. After two hours, the remaining viable bacteria were enumerated by growth on agar media plates. The effect of vaginal fluid (VF) on the microbicidal activities of H<sub>2</sub>O<sub>2 </sub>and lactic acid was also measured.</p> <p>Results</p> <p>Physiological concentrations of H<sub>2</sub>O<sub>2 </sub>(< 100 μM) failed to inactivate any of the BV-associated bacteria tested, even in the presence of human myeloperoxidase (MPO) that increases the microbicidal activity of H<sub>2</sub>O<sub>2</sub>. At 10 mM, H<sub>2</sub>O<sub>2 </sub>inactivated all four species of vaginal lactobacilli but only one of seventeen species of BV-associated bacteria. Moreover, the addition of just 1% vaginal fluid (VF) blocked the microbicidal activity of 1 M H<sub>2</sub>O<sub>2</sub>. In contrast, lactic acid at physiological concentrations (55-111 mM) and pH (4.5) inactivated all the BV-associated bacteria tested, and had no detectable effect on the vaginal lactobacilli. Also, the addition of 10% VF did not block the microbicidal activity of lactic acid.</p> <p>Conclusions</p> <p>Under optimal, anaerobic growth conditions, physiological concentrations of lactic acid inactivated BV-associated bacteria without affecting vaginal lactobacilli, whereas physiological concentrations of H<sub>2</sub>O<sub>2 </sub>produced no detectable inactivation of either BV-associated bacteria or vaginal lactobacilli. Moreover, at very high concentrations, H<sub>2</sub>O<sub>2 </sub>was more toxic to vaginal lactobacilli than to BV-associated bacteria. On the basis of these <it>in vitro </it>observations, we conclude that lactic acid, not H<sub>2</sub>O<sub>2</sub>, is likely to suppress BV-associated bacteria <it>in vivo</it>.</p
The Cauchy problem of f(R) gravity
The initial value problem of metric and Palatini f(R)gravity is studied by
using the dynamical equivalence between these theories and Brans-Dicke gravity.
The Cauchy problem is well-formulated for metric f(R)gravity in the presence of
matter and well-posed in vacuo. For Palatini f(R)gravity, instead, the Cauchy
problem is not well-formulated.Comment: 16 latex pages, to appear in Class. Quantum Grav; typographical
errors corrected, new references adde
Genomic epidemiology of the emerging pathogen Batrachochytrium dendrobatidis from native and invasive amphibian species in Chile
Emerging fungal diseases represent a threat to food security, animal and human health worldwide. Amphibian chytridiomycosis, caused by the fungus Batrachochytrium
dendrobatidis (Bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. For the first time, Bd was cultured from
native and non-native wild amphibians in Chile. Phylogenomic analyses revealed that Chilean isolates AVS2, AVS4 and AVS7 group within the global panzootic lineage of Bd (BdGPL) in a single highly supported clade that includes a genotype previously isolated
from the United Kingdom. Our results extend the known distribution of BdGPL in South America and suggest a single and relatively recent introduction of BdGPL into the country, providing additional support to the role of anthropogenic activity in the global spread of this panzootic lineage
Early-onset and classical forms of type 2 diabetes show impaired expression of genes involved in muscle branched-chain amino acids metabolism
Abstract The molecular mechanisms responsible for the pathophysiological traits of type 2 diabetes are incompletely understood. Here we have performed transcriptomic analysis in skeletal muscle, and plasma metabolomics from subjects with classical and early-onset forms of type 2 diabetes (T2D). Focused studies were also performed in tissues from ob/ob and db/db mice. We document that T2D, both early and late onset, are characterized by reduced muscle expression of genes involved in branched-chain amino acids (BCAA) metabolism. Weighted Co-expression Networks Analysis provided support to idea that the BCAA genes are relevant in the pathophysiology of type 2 diabetes, and that mitochondrial BCAA management is impaired in skeletal muscle from T2D patients. In diabetic mice model we detected alterations in skeletal muscle proteins involved in BCAA metabolism but not in obese mice. Metabolomic analysis revealed increased levels of branched-chain keto acids (BCKA), and BCAA in plasma of T2D patients, which may result from the disruption of muscle BCAA management. Our data support the view that inhibition of genes involved in BCAA handling in skeletal muscle takes place as part of the pathophysiology of type 2 diabetes, and this occurs both in early-onset and in classical type 2 diabetes
Challenges and solutions in early detection, rapid response and communication about potential invasive alien species in forests
Invasive alien species (IAS) are an important threat to forests. One of the best ways to manage potential IAS is through early detection and rapid response (EDRR) strategies. However, when dealing with IAS in forests, EU regulations are divided between phytosanitary regulations and IAS regulations. A version of EDRR for the former has been in place in the EU for more than 15 years while the latter is still in the process of being implemented. During 2019, a workshop was held to gather international experts on different plant health pests and IAS. The purpose of this workshop was to identify the opportunities and difficulties in applying the EDRR system in the EU phytosanitary and IAS legislation to four species for providing suggestions to improve the EDRR system. The model species are well known and come from different trophic levels. These species were the American pokeweed (Phytolacca americana), the grey squirrel (Sciurus carolinensis); and the plant health pests Geosmithia morbida and Emerald ash borer (Agrilus planipennis). We identified the similarities in the challenges of early detection, rapid response and communication of these species. For all species, difficulties in species identification, knowledge gaps on the pathways of spread, a lack of resources and uncertainty over which national government service was the competent authority were identified as the main challenges. Other challenges like public perception for the grey squirrel or methodological problems were species-specific. Regarding the rapid response: public perception, determination of the eradication area, sufficient scientific capacity and the lack of resources were common challenges for all species. Therefore, collaboration between institutes dealing with plant health pests and IAS can lead to better control of both groups of unwanted organisms in forests.Peer reviewe
Early-onset and classical forms of type 2 diabetes show impaired expression of genes involved in muscle branched-chain amino acids metabolism
The molecular mechanisms responsible for the pathophysiological traits of type 2 diabetes are incompletely understood. Here we have performed transcriptomic analysis in skeletal muscle, and plasma metabolomics from subjects with classical and early-onset forms of type 2 diabetes (T2D). Focused studies were also performed in tissues from ob/ob and db/db mice. We document that T2D, both early and late onset, are characterized by reduced muscle expression of genes involved in branched-chain amino acids (BCAA) metabolism. Weighted Co-expression Networks Analysis provided support to idea that the BCAA genes are relevant in the pathophysiology of type 2 diabetes, and that mitochondrial BCAA management is impaired in skeletal muscle from T2D patients. In diabetic mice model we detected alterations in skeletal muscle proteins involved in BCAA metabolism but not in obese mice. Metabolomic analysis revealed increased levels of branched-chain keto acids (BCKA), and BCAA in plasma of T2D patients, which may result from the disruption of muscle BCAA management. Our data support the view that inhibition of genes involved in BCAA handling in skeletal muscle takes place as part of the pathophysiology of type 2 diabetes, and this occurs both in early-onset and in classical type 2 diabetes
Identification of novel associations and localization of signals in idiopathic inflammatory myopathies using genome-wide imputation
Objective: The idiopathic inflammatory myopathies (IIMs) are heterogeneous diseases thought to be initiated by immune activation in genetically predisposed individuals. We imputed variants from the ImmunoChip array using a large reference panel to fine-map associations and identify novel associations in IIM. Methods: We analyzed 2,565 Caucasian IIM patient samples collected through the Myositis Genetics Consortium (MYOGEN) and 10,260 ethnically matched control samples. We imputed 1,648,116 variants from the ImmunoChip array using the Haplotype Reference Consortium panel and conducted association analysis on IIM and clinical and serologic subgroups. Results: The HLA locus was consistently the most significantly associated region. Four non-HLA regions reached genome-wide significance, SDK2 and LINC00924 (both novel) and STAT4 in the whole IIM cohort, with evidence of independent variants in STAT4, and NAB1 in the polymyositis (PM) subgroup. We also found suggestive evidence of association with loci previously associated with other autoimmune rheumatic diseases (TEC and LTBR). We identified more significant associations than those previously reported in IIM for STAT4 and DGKQ in the total cohort, for NAB1 and FAM167A-BLK loci in PM, and for CCR5 in inclusion body myositis. We found enrichment of variants among DNase I hypersensitivity sites and histone marks associated with active transcription within blood cells. Conclusion: We found novel and strong associations in IIM and PM and localized signals to single genes and immune cell types
Tumor markers in breast cancer - European Group on Tumor Markers recommendations
Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins ( CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin ( trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy. Copyright (C) 2005 S. Karger AG, Basel
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