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101.
Autophagy defects accelerate aging, while stimulation of autophagy decelerates aging. Acyl-coenzyme A binding protein (ACBP), which is encoded by a diazepam-binding inhibitor (DBI), acts as an extracellular feedback regulator of autophagy. As shown here, knockout of the gene coding for the yeast orthologue of ACBP/DBI (ACB1) improves chronological aging, and this effect is reversed by knockout of essential autophagy genes (ATG5, ATG7) but less so by knockout of an essential mitophagy gene (ATG32). In humans, ACBP/DBI levels independently correlate with body mass index (BMI) as well as with chronological age. In still-healthy individuals, we find that high ACBP/DBI levels correlate with future cardiovascular events (such as heart surgery, myocardial infarction, and stroke), an association that is independent of BMI and chronological age, suggesting that ACBP/DBI is indeed a biomarker of “biological” aging. Concurringly, ACBP/DBI plasma concentrations correlate with established cardiovascular risk factors (fasting glucose levels, systolic blood pressure, total free cholesterol, triglycerides), but are inversely correlated with atheroprotective high-density lipoprotein (HDL). In mice, neutralization of ACBP/DBI through a monoclonal antibody attenuates anthracycline-induced cardiotoxicity, which is a model of accelerated heart aging. In conclusion, plasma elevation of ACBP/DBI constitutes a novel biomarker of chronological aging and facets of biological aging with a prognostic value in cardiovascular disease.  相似文献   
102.
 The mechanism of phenanthrene transfer to the bacteria during biodegradation by a Pseudomonas strain was investigated using a sensitive respirometric technique (Sapromat equipment) allowing the quasi-continuous acquisition of data on oxygen consumption. Several systems of phenanthrene supply, crystalline solid and solutions in non-water-miscible solvents (silicone oil and 2,2,4,4,6,8,8-heptamethylnonane) were studied. In all cases, analysis of the kinetics of oxygen consumption demonstrated an initial phase of exponential growth with the same specific growth rate. In order to analyze the second phase of growth and phenanthrene degradation, a study of the kinetics of phenanthrene transfer to the aqueous phase was conducted by direct experimentation, with the crystal and silicone oil systems, in abiotic conditions. The data allowed the validation of a model based on phase-transfer laws, describing the variations, with substrate concentrations, of rates of phenanthrene transfer to the aqueous phase. Analysis of the biodegradation curves then showed that exponential growth ended in all cases when the rates of phenanthrene consumption reached the maximal transfer rates. Thereafter, the biodegradation rates closely obeyed, for all systems, the transfer rate values given by the model. These results unambiguously demonstrated that, in the present case, phenanthrene biodegradation required prior transfer to the aqueous phase. With the silicone oil system, which allowed high transfer and biodegradation rates, phenanthrene was directed towards higher metabolite production and lower mineralization, as shown by oxygen consumption and carbon balance determinations. Received: 30 November 1994/Accepted: 11 January 1995  相似文献   
103.
Summary The growth of late erythroid precursors (CFU-Es) from adult bone marrow is inhibited when Iscove's modified Dulbecco's medium supplied in liquid form is used. Catalase and other H2O2 destroying compounds restore the capacity of culture medium to support colony development. However early precursors from adult bone marrow and fetal liver CFU-Es were resistant to H2O2. This work was supported by grants from the Centre National de la Recherche Scientifique, the Institut National de la Santé et de la Recherche Médicale and the Fédération Nationale des Centres de Lutte contre le Cancer.  相似文献   
104.
Bone marrow cells from normal adult mice were introduced by microinjection via the placenta into W/Wv genetically anemic fetuses of 11 days' gestation. After birth, erythrocytes were fractionated by fluorescence-activated cell sorting on the basis of antibody binding to a fetal-specific antigen (Ft). Lysates of Ft-positive, i.e., fetal, erythrocytes did not detectably contain hemoglobin of the donor type, as judged from electrophoresis of strain-specific hemoglobin variants. Thus, adult hematopoietic bone marrow cells did not resume fetal differentiation despite their post-transplant maturation in a fetal environment.  相似文献   
105.
In chickens the erythroid differentiation proceeds from stem cells to erythrocytes through several intermediate steps which have been identified in vivo and in vitro. To determine whether Avian erythroblastosis virus (AEV) is able to transform in vitro either one or several types of these precursors, bone marrow cells were separated by physical and immunological methods. It was found that the target cells which could be transformed in vitro by AEV were cells of light density (1.060-1.065 g/cm3), having a modal sedimentation velocity at unit gravity between 4.0 and 6.0 mm/hr, expressing an immature antigen at a low level and a brain-related antigen at a high level. These results indicated that the target cells of neoplastic transformation by AEV were early erythroid precursors, since these precursors shared the same physical and immunological properties with AEV target cells.  相似文献   
106.
Summary Acetone-butanol fermentation of the Jerusalem artichoke has been studied as a case for systematic investigation of the industrial optimization of both strain selection and fermentation operation. Hydrolysis of the inulinic oligofructans of the substrate was found necessary for optimal performance but could be achieved with a selected strain using a moderate amount of inulinase added at the beginning of the fermentation. Apart from ammonia, no nutritional supplementation of the medium was found necessary. The marked influence of pH in the fermentation performance prompted a detailed search for a method of controlling pH during fermentation. With an optimized procedure, solvent production of 23–24 g/l were obtained in 36 h. Detailed fermentation balances are presented. An industrial process for ABE production from Jerusalem artichoke or sugar beet has been defined and tested in the pilot plant.  相似文献   
107.
Changes in fish distribution are being observed across the globe. In Europe's Common Fisheries Policy, the share of the catch of each fish stock is split among management areas using a fixed allocation key known as ‘Relative Stability’: in each management area, member states get the same proportion of the total catch each year. That proportion is largely based on catches made by those member states in the 1970s. Changes in distribution can, therefore, result in a mismatch between quota shares and regional abundances within management areas, with potential repercussions for the status of fish stocks and the fisheries that depend on them. Assessing distribution changes is crucial to ensure adequate management and sustainable exploitation of our fish resources. We analysed scientific survey data using a three-tiered analytical approach to provide, for the first time, an overview of changes in distribution for 19 northeast Atlantic fish species encompassing 73 commercial stocks over 30 yr. All species have experienced changes in distribution, five of which did so across management areas. A cross-species analysis suggested that shifts in areas of suitable thermal habitat, and density-dependent use of these areas, are at least partly responsible for the observed changes. These findings challenge the current use of relative stability to allocate quotas.  相似文献   
108.

Background  

Estimators of free energies are routinely used to judge the quality of protein structural models. As these estimators still present inaccuracies, they are frequently evaluated by discriminating native or native-like conformations from large ensembles of so-called decoy structures.  相似文献   
109.
Macdonald et al. (Ecol. Lett., 21, 2018, 207–216) proposed an analytical framework for identifying evolutionary processes underlying trait‐environment relationships observed in natural populations. Here, we propose an expanded and refined framework based on simulations and bootstrap‐based approaches, and we elaborate on an important statistical caveat common to most datasets.  相似文献   
110.
Peripheral mechanisms responsible for penile erection are dependant upon a complex control by the nervous system, including peripheral nervous pathways, spinally mediated reflex loops and supraspinal nervous structures. Spinal cord injury is accompanied by a partial or a complete modification of these controls. In relation to the reflexogenic or psychogenic origin of penile erection, spinal cord injury does not cause the same effects. Reflexogenic erections sitll occur after spinal cord injury at a suprasacral level. After lesions at a level lower than the thoracolumbar spinal cord, tumescence following psychogenic stimulation has been observed. The hypotheses resulting from clinical and experimental observations and explaining the differences at the origin of these response are detailed. The recent developments in the neurophysiology of penile erection and the role of neurotransmitters allow a more analytical approach of the phenomenous and also bring new insights into possible compensatory pathways following spinal cord injury.  相似文献   
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