81 research outputs found
Control of Risk Factors Among People With Diagnosed Diabetes, by Lower Extremity Disease Status
Introduction We examined the control of modifiable risk factors among a national sample of diabetic people with and without lower extremity disease (LED). Methods The sample from the 1999-2004 National Health and Nutrition Examination Survey consisted of 948 adults aged 40 years or older with diagnosed diabetes and who had been assessed for LED. LED was defined as peripheral arterial disease (ankle-brachial index <0.9), peripheral neuropathy (≥1 insensate area), or presence of foot ulcer. Good control of modifiable risk factors, based on American Diabetes Association recommendations, included being a nonsmoker and having the following measurements: hemoglobin A1c (HbA1c) less than 7%, systolic blood pressure less than or equal to 130 mm Hg, diastolic blood pressure less than or equal to 80 mm Hg, high-density lipoprotein (HDL) cholesterol greater than 50 mg/dL, and body mass index (BMI) between 18.5 kg/m2 and 24.9 kg/m2. Results Diabetic people with LED were less likely than were people without LED to have recommended levels of HbA1c (39.3% vs 53.5%) and HDL cholesterol (29.7% vs 41.1%), but there were no differences in systolic or diastolic blood pressure, BMI classification, or smoking status between people with and without LED. Control of some risk factors differed among population subgroups. Notably, among diabetic people with LED, non-Hispanic blacks were more likely to have improper control of HbA1c (adjusted odds ratio [AOR] = 2.0; 95% confidence interval [CI], 1.1-3.9), systolic blood pressure (AOR = 1.9; 95% CI, 1.1-3.2), and diastolic blood pressure (AOR = 2.6; 95% CI, 1.1-5.8), compared with non-Hispanic whites. Conclusion Control of 2 of 6 modifiable risk factors was worse in diabetic adults with LED compared with diabetic adults without LED. Among diabetic people with LED, non-Hispanic blacks had worse control of 3 of 6 risk factors compared with non-Hispanic whites
Dirac states with knobs on: interplay of external parameters and the surface electronic properties of 3D topological insulators
Topological insulators are a novel materials platform with high applications
potential in fields ranging from spintronics to quantum computation. In the
ongoing scientific effort to demonstrate controlled manipulation of their
electronic structure by external means, stoichiometric variation and surface
decoration are two effective approaches that have been followed. In ARPES
experiments, both approaches are seen to lead to electronic band structure
changes. Such approaches result in variations of the energy position of bulk
and surface-related features and the creation of two-dimensional electron
gases.The data presented here demonstrate that a third manipulation handle is
accessible by utilizing the amount of illumination a topological insulator
surface has been exposed to under typical experimental ARPES conditions. Our
results show that this new, third, knob acts on an equal footing with
stoichiometry and surface decoration as a modifier of the electronic band
structure, and that it is in continuous competition with the latter. The data
clearly point towards surface photovoltage and photo-induced desorption as the
physical phenomena behind modifications of the electronic band structure under
exposure to high-flux photons. We show that the interplay of these phenomena
can minimize and even eliminate the adsorbate-related surface band bending on
typical binary, ternary and quaternary Bi-based topological insulators.
Including the influence of the sample temperature, these data set up a
framework for the external control of the electronic band structure in
topological insulator compounds in an ARPES setting. Four external knobs are
available: bulk stoichiometry, surface decoration, temperature and photon
exposure. These knobs can be used in conjunction to tune the band energies near
the surface and consequently influence the topological properties of the
relevant electronic states.Comment: 16 pages, 8 figure
Breaking Local Baryon and Lepton Number at the TeV Scale
Simple models are proposed where the baryon and lepton number are gauged and
spontaneously broken near the weak scale. The models use a fourth generation
that is vector-like with respect to the strong, weak and electromagnetic
interactions to cancel anomalies. One does not need large Yukawa couplings to
be consistent with the experimental limits on fourth generation quark masses
and hence the models are free of Landau poles near the weak scale. We discuss
the main features of simple non-supersymmetric and supersymmetric models. In
these models the light neutrino masses are generated through the seesaw
mechanism and proton decay is forbidden even though B and L are broken near the
weak scale. For some values of the parameters in these models baryon and/or
lepton number violation can be observed at the Large Hadron Collider.Comment: minor corrections, to appear in JHE
Dexmedetomidine is neuroprotective in an in vitro model for traumatic brain injury
<p>Abstract</p> <p>Background</p> <p>The α<sub>2</sub>-adrenoreceptor agonist dexmedetomidine is known to provide neuroprotection under ischemic conditions. In this study we investigated whether dexmedetomidine has a protective effect in an <it>in vitro </it>model for traumatic brain injury.</p> <p>Methods</p> <p>Organotypic hippocampal slice cultures were subjected to a focal mechanical trauma and then exposed to varying concentrations of dexmedetomidine. After 72 h cell injury was assessed using propidium iodide. In addition, the effects of delayed dexmedetomidine application, of hypothermia and canonical signalling pathway inhibitors were examined.</p> <p>Results</p> <p>Dexmedetomidine showed a protective effect on traumatically injured hippocampal cells with a maximum effect at a dosage of 1 μM. This effect was partially reversed by the simultaneous administration of the ERK inhibitor PD98059.</p> <p>Conclusion</p> <p>In this TBI model dexmedetomidine had a significant neuroprotective effect. Our results indicate that activation of ERK might be involved in mediating this effect.</p
Mechanism of Action of Cyclophilin A Explored by Metadynamics Simulations
Trans/cis prolyl isomerisation is involved in several biological processes, including the development of numerous diseases. In the HIV-1 capsid protein (CA), such a process takes place in the uncoating and recruitment of the virion and is catalyzed by cyclophilin A (CypA). Here, we use metadynamics simulations to investigate the isomerization of CA's model substrate HAGPIA in water and in its target protein CypA. Our results allow us to propose a novel mechanistic hypothesis, which is finally consistent with all of the available molecular biology data
Design and Analysis of Rhesus Cytomegalovirus IL-10 Mutants as a Model for Novel Vaccines against Human Cytomegalovirus
Human cytomegalovirus (HCMV) expresses a viral ortholog (CMVIL-10) of human cellular interleukin-10 (cIL-10). Despite only ∼26% amino acid sequence identity, CMVIL-10 exhibits comparable immunosuppressive activity with cIL-10, attenuates HCMV antiviral immune responses, and contributes to lifelong persistence within infected hosts. The low sequence identity between CMVIL-10 and cIL-10 suggests vaccination with CMVIL-10 may generate antibodies that specifically neutralize CMVIL-10 biological activity, but not the cellular cytokine, cIL-10. However, immunization with functional CMVIL-10 might be detrimental to the host because of its immunosuppressive properties.Structural biology was used to engineer biologically inactive mutants of CMVIL-10 that would, upon vaccination, elicit a potent immune response to the wild-type viral cytokine. To test the designed proteins, the mutations were incorporated into the rhesus cytomegalovirus (RhCMV) ortholog of CMVIL-10 (RhCMVIL-10) and used to vaccinate RhCMV-infected rhesus macaques. Immunization with the inactive RhCMVIL-10 mutants stimulated antibodies against wild-type RhCMVIL-10 that neutralized its biological activity, but did not cross-react with rhesus cellular IL-10.This study demonstrates an immunization strategy to neutralize RhCMVIL-10 biological activity using non-functional RhCMVIL-10 antigens. The results provide the methodology for targeting CMVIL-10 in vaccine, and therapeutic strategies, to nullify HCMV's ability to (1) skew innate and adaptive immunity, (2) disseminate from the site of primary mucosal infection, and (3) establish a lifelong persistent infection
Genome of the anaerobic fungus Orpinomyces sp. strain C1A reveals the unique evolutionary history of a remarkable plant biomass degrader
Anaerobic gut fungi represent a distinct early-branching fungal phylum (Neocallimastigomycota) and reside in the rumen, hindgut, and feces of ruminant and nonruminant herbivores. The genome of an anaerobic fungal isolate, Orpinomyces sp. strain C1A, was sequenced using a combination of Illumina and PacBio single-molecule real-time (SMRT) technologies. The large genome (100.95 Mb, 16,347 genes) displayed extremely low G+C content (17.0%), large noncoding intergenic regions (73.1%), proliferation of microsatellite repeats (4.9%), and multiple gene duplications. Comparative genomic analysis identified multiple genes and pathways that are absent in Dikarya genomes but present in early-branching fungal lineages and/or nonfungal Opisthokonta. These included genes for posttranslational fucosylation, the production of specific intramembrane proteases and extracellular protease inhibitors, the formation of a complete axoneme and intraflagellar trafficking machinery, and a near-complete focal adhesion machinery. Analysis of the lignocellulolytic machinery in the C1A genome revealed an extremely rich repertoire, with evidence of horizontal gene acquisition from multiple bacterial lineages. Experimental analysis indicated that strain C1A is a remarkable biomass degrader, capable of simultaneous saccharification and fermentation of the cellulosic and hemicellulosic fractions in multiple untreated grasses and crop residues examined, with the process significantly enhanced by mild pretreatments. This capability, acquired during its separate evolutionary trajectory in the rumen, along with its resilience and invasiveness compared to prokaryotic anaerobes, renders anaerobic fungi promising agents for consolidated bioprocessing schemes in biofuels production.Peer reviewedMicrobiology and Molecular GeneticsBiosystems and Agricultural Engineerin
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