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Found 37769 matches. Displaying 4991-5000
Dahan R, Ravetch JV
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Co-targeting of Adenosine Signaling Pathways for Immunotherapy: Potentiation by Fc Receptor Engagement

CANCER CELL 2016 SEP 12; 30(3):369-371
Targeting the signaling pathway of the immunosuppressive metabolite adenosine is an emerging approach for cancer immunotherapy. In this issue of Cancer Cell, Young et al. describe that co-inhibition of the adenosingenic pathway through blockade of both CD73 and A2AR enhances antitumor efficacy through distinct mechanisms.
Barad DH, Kushnir VA, Gleicher N
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The importance of redundancy of functional ovarian reserve when investigating potential genetic effects on ovarian function

JOURNAL OF ASSISTED REPRODUCTION AND GENETICS 2016 SEP; 33(9):1157-1160
Li K, Nakajima M, Ibanez-Tallon I, Heintz N
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A Cortical Circuit for Sexually Dimorphic Oxytocin-Dependent Anxiety Behaviors

CELL 2016 SEP 22; 167(1):60-72
The frequency of human social and emotional disorders varies significantly between males and females. We have recently reported that oxytocin receptor interneurons (OxtrINs) modulate female sociosexual behavior. Here, we show that, in male mice, OxtrINs regulate anxiety-related behaviors. We demonstrate that corticotropin-releasing-hormone-binding protein (CRHBP), an antagonist of the stress hormone CRH, is specifically expressed in OxtrINs. Production of CRHBP blocks the CRH-induced potentiation of postsynaptic layer 2/3 pyramidal cell activity of male, but not female, mice, thus producing an anxiolytic effect. Our data identify OxtrINs as critical for modulation of social and emotional behaviors in both females and males and reveal a molecular mechanism that acts on local medial prefrontal cortex (mPFC) circuits to coordinate responses to OXT and CRH. They suggest that additional studies of the impact of the OXT/OXTR and CRHBP/CRH pathways in males and females will be important in development of gender-specific therapies.
Cohen JE, Lai JS, Coomes DA, Allen RB
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Taylor's law and related allometric power laws in New Zealand mountain beech forests: the roles of space, time and environment

OIKOS 2016 SEP; 125(9):1342-1357
Taylor's law says that the variance of population density of a species is proportional to a power of mean population density. Density-mass allometry says that mean population density is proportional to a power of mean biomass per individual. These power laws predict a third, variance-mass allometry: the variance of population density of a species is proportional to a power of mean biomass per individual. We tested these laws using 10 censuses of New Zealand mountain beech trees in 250 plots over 30 years at spatial scales from 5 m to kilometers. We found that: 1) a single-species forest not disrupted by humans obeyed all three laws; 2) random sampling explained the parameters of Taylor's law at a large spatial scale in 8 of 10 censuses, but not at a fine spatial scale; 3) larger spatial scale increased the exponent of Taylor's law and decreased the exponent of variance-mass allometry (this is the first empirical demonstration that the latter exponent depends on spatial scale), but affected the exponent of density-mass allometry slightly; 4) despite varying natural disturbance, the three laws varied relatively little over the 30 years; 5) self-thinning and recruiting plots had significantly different intercepts and slopes of density-mass allometry and variance-mass allometry, but the parameters of Taylor's law were not usually significantly affected; and 6) higher soil calcium was associated with higher variance of population density in all censuses but not with a difference in the exponent of Taylor's law, while elevation above sea level and soil carbon-to-nitrogen ratios had little effect on the parameters of Taylor's law. In general, the three laws were remarkably robust. When their parameters were influenced by spatial scale and environmental factors, the parameters could not be species-specific indicators. We suggest biological mechanisms that may explain some of these findings.
Gleicher N, Vidali A, Braverman J, Kushnir VA, Barad DH, Hudson C, Wu YG, Wang Q, Zhang L, Albertini DF
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Accuracy of preimplantation genetic screening (PGS) is compromised by degree of mosaicism of human embryos

REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY 2016 SEP 5; 14(?):? Article 54
Background: To preclude transfer of aneuploid embryos, current preimplantation genetic screening (PGS) usually involves one trophectoderm biopsy at blastocyst stage, assumed to represent embryo ploidy. Whether one such biopsy can correctly assess embryo ploidy has recently, however, been questioned. Methods: This descriptive study investigated accuracy of PGS in two ways. Part I: Two infertile couples donated 11 embryos, previously diagnosed as aneuploid and, therefore, destined to be discarded. They were dissected into 37 anonymized specimens, and sent to another national laboratory for repeat analyses to assess (i) inter-laboratory congruity and (ii) intra-embryo congruity of multiple embryo biopsies in a single laboratory. Part II: Reports on human IVF cycle outcomes after transfer of allegedly aneuploid embryos into 8 infertile patients. Results: Only 2/11 (18.2 %) embryos were identically assessed at two PGS laboratories; 4/11 (36.4 %), on repeat analysis were chromosomally normal, 2 mosaic normal/abnormal, and 5/11 (45.5 %) completely differed in reported aneuploidies. In intra-embryo analyses, 5/10 (50 %) differed between biopsy sites. Eight transfers of previously reported aneuploid embryos resulted in 5 chromosomally normal pregnancies, 4 delivered and 1 ongoing. Three patients did not conceive, though 1 among them experienced a chemical pregnancy. Conclusions: Though populations of both study parts are too small to draw statistically adequately powered conclusions on specific degrees of inaccuracy of PGS, here presented results do raise concerns especially about false-positive diagnoses. While inter-laboratory variations may at least partially be explained by different diagnostic platforms utilized, they cannot explain observed intra-embryo variations, suggesting more frequent trophectoderm mosiaicsm than previously reported. Together with recentl published mouse studies of lineages-specific degrees of survival of aneuploid cells in early stage embryos, these results call into question the biological basis of PGS, based on the assumption that a single trophectoderm biopsy can reliably determine embryo ploidy.
Thengone D, Gagnidze K, Pfaff D, Proekt A
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Phase-Amplitude Coupling in Spontaneous Mouse Behavior

PLOS ONE 2016 SEP 15; 11(9):? Article e0162262
The level of activity of many animals including humans rises and falls with a period of similar to 24 hours. The intrinsic biological oscillator that gives rise to this circadian oscillation is driven by a molecular feedback loop with an approximately 24 hour cycle period and is influenced by the environment, most notably the light: dark cycle. In addition to the circadian oscillations, behavior of many animals is influenced by multiple oscillations occurring at fasterultradian-time scales. These ultradian oscillations are also thought to be driven by feedback loops. While many studies have focused on identifying such ultradian oscillations, less is known about how the ultradian behavioral oscillations interact with each other and with the circadian oscillation. Decoding the coupling among the various physiological oscillators may be important for understanding how they conspire together to regulate the normal activity levels, as well in disease states in which such rhythmic fluctuations in behavior may be disrupted. Here, we use a wavelet-based cross-frequency analysis to show that different oscillations identified in spontaneous mouse behavior are coupled such that the amplitude of oscillations occurring at higher frequencies are modulated by the phase of the slower oscillations. The patterns of these interactions are different among different individuals. Yet this variability is not random. Differences in the pattern of interactions are confined to a low dimensional subspace where different patterns of interactions formclusters. These clusters expose the differences among individuals-males and females are preferentially segregated into different clusters. These sex-specific features of spontaneous behavior were not apparent in the spectra. Thus, our methodology reveals novel aspects of the structure of spontaneous animal behavior that are not observable using conventional methodology.
Bigio B, Nasca C, McEwen BS
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REPLY TO ARDUINI ET AL.: Acetyl-L-carnitine and the brain: Epigenetics, energetics, and stress

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2016 SEP 27; 113(39):E5700-E5701
Belousov R, Cohen EGD, Rondoni L
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Langevin equation for systems with a preferred spatial direction

PHYSICAL REVIEW E 2016 SEP 22; 94(3):? Article 032127
In this paper, we generalize the theory of Brownian motion and the Onsager-Machlup theory of fluctuations for spatially symmetric systems to equilibrium and nonequilibrium steady-state systems with a preferred spatial direction, due to an external force. To do this, we extend the Langevin equation to include a bias, which is introduced by an external force and alters the Gaussian structure of the system's fluctuations. In addition, by solving this extended equation, we provide a physical interpretation for the statistical properties of the fluctuations in these systems. Connections of the extended Langevin equation with the theory of active Brownian motion are discussed as well.
Martel J, Wu CY, Young JD
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Translocation of mineralo-organic nanoparticles from blood to urine: a new mechanism for the formation of kidney stones?

NANOMEDICINE 2016 SEP; 11(18):2399-2404
Recent studies indicate that mineralo-organic nanoparticles form in various human body fluids, including blood and urine. These nanoparticles may form within renal tubules and increase in size in supersaturated urine, eventually leading to the formation of kidney stones. Here, we present observations suggesting that mineralo-organic nanoparticles found in blood may induce kidney stone formation via an alternative mechanism in which the particles translocate through endothelial and renal epithelial cells to reach urine. We propose that this alternative mechanism of kidney stone formation and the study of mineralo-organic nanoparticles in general may provide novel strategies for the early detection and treatment of ectopic calcifications and kidney stones.
Kang HS, Charlop-Powers Z, Brady SF
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Multiplexed CRISPR/Cas9-and TAR-Mediated Promoter Engineering of Natural Product Biosynthetic Gene Clusters in Yeast

ACS SYNTHETIC BIOLOGY 2016 SEP; 5(9):1002-1010
The use of DNA sequencing to guide the discovery of natural products has emerged as a new paradigm for revealing chemistries encoded in bacterial genomes. A major obstacle to implementing this approach to natural product discovery is the transcriptional silence of biosynthetic gene clusters under laboratory growth conditions. Here we describe an improved yeast-based promoter engineering platform (mCRISTAR) that combines CRISPR/Cas9 and TAR to enable single-marker multiplexed promoter engineering of large gene clusters. mCRISTAR highlights the first application of the CRISPR/Cas9 system to multiplexed promoter engineering of natural product biosynthetic gene clusters. In this method, CRISPR/Cas9 is used to induce DNA double-strand breaks in promoter regions of biosynthetic gene clusters, and the resulting operon fragments are reassembled by TAR using synthetic gene cluster-specific promoter cassettes. mCRISTAR uses a CRISPR array to simplify the construction of a CRISPR plasmid for multiplex CRISPR and a single auxotrophic selection to improve the inefficiency of using a CRISPR array for multiplex gene cluster refactoring. mCRISTAR is a simple and generic method for multiplexed replacement of promoters in biosynthetic gene clusters that will facilitate the discovery of natural products from the rapidly growing collection of gene clusters found in microbial genome and metagenome sequencing projects.