2,663 research outputs found
RHEBI Expression in Embryonic and Postnatal Mouse
Ras homolog enriched in brain (RHEB1) is a member within the superfamily of GTP-binding proteins encoded by the RAS oncogenes. RHEB1 is located at the crossroad of several important pathways including the insulin-signaling pathways and thus plays an important role in different physiological processes. To understand better the physiological relevance of RHEB1 protein, the expres- sion pattern of RHEB1 was analyzed in both embryonic (at E3.5âE16.5) and adult (1-month old) mice. RHEB1 immu- nostaining and X-gal staining were used for wild-type and Rheb1 gene trap mutant mice, respectively. These inde- pendent methods revealed similar RHEB1 expression pat- terns during both embryonic and postnatal developments. Ubiquitous uniform RHEB1/ÎČ-gal and/or RHEB1 expres- sion was seen in preimplantation embryos at E3.5 and post- implantation embryos up to E12.5. Between stages E13.5 and E16.5, RHEB1 expression levels became complex: In particular, strong expression was identified in neural tis- sues, including the neuroepithelial layer of the mesenceph- alon, telencephalon, and neural tube of CNS and dorsal root ganglia. In addition, strong expression was seen in certain peripheral tissues including heart, intestine, muscle, and urinary bladder. Postnatal mice have broad spatial RHEB1 expression in different regions of the cerebral cortex, sub- cortical regions (including hippocampus), olfactory bulb, medulla oblongata, and cerebellum (particularly in Purkinje cells). Significant RHEB1 expression was also viewed in internal organs including the heart, intestine, urinary blad- der, and muscle. Moreover, adult animals have complex tis- sue- and organ-specific RHEB1 expression patterns with different intensities observed throughout postnatal develop- ment. Its expression level is in general comparable in CNS and other organs of mouse. Thus, the expression pattern of RHEB1 suggests that it likely plays a ubiquitous role in the development of the early embryo with more tissue-specific roles in later development
RHEB1 Expression in Embryonic and Postnatal Mouse
Ras homolog enriched in brain (RHEB1) is a member within the superfamily of GTP-binding proteins encoded by the RAS oncogenes. RHEB1 is located at the crossroad of several important pathways including the insulin-signaling pathways and thus plays an important role in different physiological processes. To understand better the physiological relevance of RHEB1 protein, the expres-sion pattern of RHEB1 was analyzed in both embryonic (at E3.5âE16.5) and adult (1-month old) mice. RHEB1 immu-nostaining and X-gal staining were used for wild-type and Rheb1 gene trap mutant mice, respectively. These inde-pendent methods revealed similar RHEB1 expression pat-terns during both embryonic and postnatal developments. Ubiquitous uniform RHEB1/ÎČ-gal and/or RHEB1 expres-sion was seen in preimplantation embryos at E3.5 and post-implantation embryos up to E12.5. Between stages E13.5 and E16.5, RHEB1 expression levels became complex: In particular, strong expression was identified in neural tis-sues, including the neuroepithelial layer of the mesenceph-alon, telencephalon, and neural tube of CNS and dorsal root ganglia. In addition, strong expression was seen in certain peripheral tissues including heart, intestine, muscle, and urinary bladder. Postnatal mice have broad spatial RHEB1 expression in different regions of the cerebral cortex, sub-cortical regions (including hippocampus), olfactory bulb, medulla oblongata, and cerebellum (particularly in Purkinje cells). Significant RHEB1 expression was also viewed in internal organs including the heart, intestine, urinary blad-der, and muscle. Moreover, adult animals have complex tis-sue- and organ-specific RHEB1 expression patterns with different intensities observed throughout postnatal develop-ment. Its expression level is in general comparable in CNS and other organs of mouse. Thus, the expression pattern of RHEB1 suggests that it likely plays a ubiquitous role in the development of the early embryo with more tissue-specific roles in later development
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Hospital Acquired Pneumonia Is Linked to Right Hemispheric Peri-Insular Stroke
Purpose Hospital acquired pneumonia (HAP) is a major complication of stroke. We sought to determine associations between infarction of specific brain regions and HAP. Methods: 215 consecutive acute stroke patients with HAP (2003â2009) were carefully matched with 215 non-pneumonia controls by gender, then NIHSS, then age. Admission imaging and binary masks of infarction were registered to MNI-152 space. Regional atlas and voxel-based log-odds were calculated to assess the relationship between infarct location and the likelihood of HAP. An independently validated penalized conditional logistic regression model was used to identify HAP associated imaging regions. Results: The HAP and control patients were well matched by gender (100%), age (95% within 5-years), NIHSS (98% within 1-point), infarct size, dysphagia, and six other clinical variables. Right hemispheric infarcts were more frequent in patients with HAP versus controls (43.3% vs. 34.0%, p = 0.054), whereas left hemispheric infarcts were more frequent in controls (56.7% vs. 44.7%, p = 0.012); there was no significant difference between groups in the rate of brainstem strokes (p = 1.0). Of the 10 most infarcted regions, only right insular cortex volume was different in HAP versus controls (20 vs. 12 ml, p = 0.02). In univariate analyses, the highest log-odds regions for pneumonia were right hemisphere, cerebellum, and brainstem. The best performing multivariate model selected 7 brain regions of infarction and 2 infarct volume-based variables independently associated with HAP. Conclusions: HAP is associated with right hemispheric peri-insular stroke. These associations may be related to autonomic modulation of immune mechanisms, supporting recent hypotheses of stroke mediated immune suppression
Observation of coherent oscillations in association of dimers from a thermal gas of ultracold atoms
We report the observation of coherent oscillations in conversion efficiency
of molecules formed from a thermal gas of ultracold atoms. Finite thermal
energy of the gas causes loss of coherence when a broad continuum is resonantly
coupled to a discrete bound state. Restoration of the coherence can be achieved
through non-adiabatic transitions of the dressed molecular energy level that
are induced by a strong modulation pulse with fast envelope dynamics.
Conditions to observe coherent oscillations are verified, and control of their
properties is demonstrated. The main experimental findings are supported by
theoretical modeling and numerical calculations.Comment: 7 pages, 3 figure
A programme for risk assessment and minimisation of progressive multifocal leukoencephalopathy developed for vedolizumab clinical trials
Introduction Over the past decade, the potential for drug-associated progressive multifocal leukoencephalopathy (PML) has become an increasingly important consideration in certain drug development programmes, particularly those of immunomodulatory biologics. Whether the risk of PML with an investigational agent is proven (e.g. extrapolated from relevant experience, such as a class effect) or merely theoretical, the serious consequences of acquiring PML require careful risk minimisation and assessment. No single standard for such risk minimisation exists. Vedolizumab is a recently developed monoclonal antibody to α4ÎČ7 integrin. Its clinical development necessitated a dedicated PML risk minimisation assessment as part of a global preapproval regulatory requirement.
Objective The aim of this study was to describe the multiple risk minimisation elements that were incorporated in vedolizumab clinical trials in inflammatory bowel disease patients as part of the risk assessment and minimisation of PML programme for vedolizumab.
Methods A case evaluation algorithm was developed for sequential screening and diagnostic evaluation of subjects who met criteria that indicated a clinical suspicion of PML. An Independent Adjudication Committee provided an independent, unbiased opinion regarding the likelihood of PML.
Results Although no cases were detected, all suspected PML events were thoroughly reviewed and successfully adjudicated, making it unlikely that cases were missed.
Conclusion We suggest that this programme could serve as a model for pragmatic screening for PML during the clinical development of new drugs
Complex dynamical networks constructed with fully controllable nonlinear nanomechanical oscillators
Control of the global parameters of complex networks has been explored experimentally in a variety of contexts. Yet, the more difficult prospect of realizing arbitrary network architectures, especially analog physical networks that provide dynamical control of individual nodes and edges, has remained elusive. Given the vast hierarchy of time scales involved, it also proves challenging to measure a complex networkâs full internal dynamics. These span from the fastest nodal dynamics to very slow epochs over which emergent global phenomena, including network synchronization and the manifestation of exotic steady states, eventually emerge. Here, we demonstrate an experimental system that satisfies these requirements. It is based upon modular, fully controllable, nonlinear radio frequency nanomechanical oscillators, designed to form the nodes of complex dynamical networks with edges of arbitrary topology. The dynamics of these oscillators and their surrounding network are analog and continuous-valued and can be fully interrogated in real time. They comprise a piezoelectric nanomechanical membrane resonator, which serves as the frequency-determining element within an electrical feedback circuit. This embodiment permits network interconnections entirely within the electrical domain and provides unprecedented node and edge control over a vast region of parameter space. Continuous measurement of the instantaneous amplitudes and phases of every constituent oscillator node are enabled, yielding full and detailed network data without reliance upon statistical quantities. We demonstrate the operation of this platform through the real-time capture of the dynamics of a three-node ring network as it evolves from the uncoupled state to full synchronization
Drag on particles in a nematic suspension by a moving nematic-isotropic interface
We report the first clear demonstration of drag on colloidal particles by a moving nematic-isotropic
interface. The balance of forces explains our observation of periodic, strip-like structures that are produced by the movement of these particles
Defect structures and torque on an elongated colloidal particle immersed in a liquid crystal host
Combining molecular dynamics and Monte Carlo simulation we study defect
structures around an elongated colloidal particle embedded in a nematic liquid
crystal host. By studying nematic ordering near the particle and the
disclination core region we are able to examine the defect core structure and
the difference between two simulation techniques. In addition, we also study
the torque on a particle tilted with respect to the director, and modification
of this torque when the particle is close to the cell wall
Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets.
We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150âTW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20âMeV with particle numbers exceeding 109 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (â
5âÎŒm) and planar (20âÎŒmâĂâ2âÎŒm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions
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