2,522 research outputs found
New Insights Revealed by Genetic Studies and the Future of Treating Bone Health Related Issues
Biomedical Tissue Engineering - Where We Go in the Future PanelThis presentation will examine the major role played by genetic studies in the identification of a fundamental pathway, the Wnt/β-catenin signaling pathway, and it's now appreciated multiple roles in bone cell biology. Specifically I will discuss how the genetic analysis of several families led to the discovery of this pathway and briefly summarize our work at understanding it's central role in the responsiveness of bone to mechanical loading. These studies have recently focused our attention on developing a better understanding of the strain environment within bone at the level of the osteocyte and how physical signals regulates the function of this bone cell. These fundamental studies will be of critical importance to our understanding of how to treat bone diseases such as osteoporosis and for the design of better scaffolds for use in fracture repair and bone regeneration
Effect of Radius on Load/Strain Distribution between Ulna and Radius: Experimental and Numberical Analyses
Computational Infrastructure and Informatics Poster SessionIt has been hypothesized that osteocytes are stimulated by local strain distribution within the bone subjected to mechanical loadings. This collaborative research project between bone biologists and mechanical engineers is attempting to identify local strain fields around osteocytes that can account for their behavior in response to loading. Using CT images we have built and conducted an extensive finite element study of the mouse forearm. Our model incorporates many components of forearm anatomy not previously included in these models such as the radius and marrow cavities. The results of the current research will shed light on how bone perceives mechanical load and the pathway whereby a physical load is transduced into a biochemical signal that eventually results in new bone formation. The study will help in developing new treatments for bone diseases such as osteoporosis
Development of a Telemetry Unit for Wireless Monitoring of Bone Strain
Computational Infrastructure and Informatics Poster SessionA telemetry unit designed to monitor strain in bones is presented. This unit allows studying the relationship between bone load and bone mass in scenarios that were not possible with current setup. The current measuring setup employs a bench top load instrument and a data acquisition unit to read the output of strain gage sensors attached to the ulna of a mouse. Although precise, this setup is bulky and requires complete immobilization of the mouse. The telemetry unit developed by the authors replaces the data acquisition unit in the current setup and is able to wirelessly transmit the readings of the strain gage to a remote computer. The telemetry unit makes possible the collection of bone strain data in scenarios where the mouse is free to move or while performing fatigue-inducing exercises. The unit has been designed around an ultra low-power microcontroller (MSP430). The microcontroller makes the design highly flexible and programmable. The telemetry unit also includes a high-performance instrumentation amplifier to amplify the strain gage output. The gain and offset of the amplifier are digitally set by the microcontroller eliminating the use of manual potentiometers. The board has an expansion connector that allows up to 16 additional strain gages to be connected to the unit and incorporates a low-power radio transceiver operating in the 2.4 GHz ISM band. The data transmitted by the unit is received by a base station connected to a computer via a USB cable. The telemetry unit has been tested in a lab setting and is able to transmit the strain data at distances greater than 20 m while consuming less than 30 mW of power. This low power consumption allows the unit to be powered by a micro-battery weighting less than 3 grams. The telemetry unit can be used in other biomedical applications such as in the monitoring of orthopedic implants and can be easily configured to use other type of sensors
Flexible Carbon Nanotube-Based Strain Gage Sensors
Jump Starting Technologies, Patent Issues, & Translational Medicine Poster SessionAging brings about dramatic changes in the skeleton and other organ systems. Major skeletal diseases associated with aging include osteoporosis and attendant fractures (hip, spine and wrist or Collies) and osteoarthritis and its resulting need for various joint replacements. The prosthetic joint market in the United Sates is between 780. Equipment and lab facilities are available at UMKC. Carbon nanotubes are commercially available from NanoLab Inc. Copper nanoparticles and other chemicals can be acquired from Sigma-Aldrich. A timeline of one year will be needed to fine tune the fabrication process and characterize the strain gages
Biomedical Tissue Engineering - Where We Go in the Future
Researchers and entrepreneurs examine breakthroughs in tissue engineering and regeneration that enhance healing, remodeling, and recovery
The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 With a Large Dense Core
Doppler measurements from Subaru and Keck have revealed radial velocity
variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass
planet in a 2.8766 day orbit. Photometric observations at Fairborn Observatory
have detected three complete transit events with depths of 0.003 mag at the
predicted times of conjunction. HD 149026 is now the second brightest star with
a transiting extrasolar planet. The mass of the star, based on interpolation of
stellar evolutionary models, is 1.3 +/- 0.1 solar masses; together with the
Doppler amplitude, K=43.3 m s^-1, we derive a planet mass Msin(i)=0.36 Mjup,
and orbital radius of 0.042 AU. HD 149026 is chromospherically inactive and
metal-rich with spectroscopically derived [Fe/H]=+0.36, Teff=6147 K, log g=4.26
and vsin(i)=6.0 km s^-1. Based on Teff and the stellar luminosity of 2.72 Lsun,
we derive a stellar radius of 1.45 Rsun. Modeling of the three photometric
transits provides an orbital inclination of 85.3 +/- 1.0 degrees and (including
the uncertainty in the stellar radius) a planet radius of 0.725 +/- 0.05 Rjup.
Models for this planet mass and radius suggest the presence of a ~67 Mearth
core composed of elements heavier than hydrogen and helium. This substantial
planet core would be difficult to construct by gravitational instability.Comment: 25 pages, 5 figures, accepted by the Astrophysical Journa
Comparison of facet joint activity on 99mTc-MDP SPECT/CT with facet joint signal change on MRI with fat suppression
PURPOSEWe compared signal change on magnetic resonance imaging (MRI) with fat suppression and bone scan activity of lumbar facet joints to determine if these two imaging findings are correlated.METHODSWe retrospectively identified all patients who underwent imaging of the lumbar spine for pain evaluation using both technetium-99m methylene disphosphonate single-photon emission computed tomography/computed tomography (99mTc-MDP SPECT/CT) and MRI with at least one fat-suppressed T2- or T1-weighted sequence with gadolinium enhancement within a 180-day interval, at our institution between 1 January 2008 and 19 February 2013. Facet joint activity on 99mTc-MDP SPECT/CT and peri-facet signal change on MRI were rated as normal or increased. Agreement between the two examination types were determined with the κ and prevalence-adjusted bias-adjusted κ (PABAK) statistics.RESULTSThis study included 60 patients (28 male, 47%), with a mean age of 49±19.7 years (range, 12–93 years). The κ value indicated no agreement between 99mTc-MDP SPECT/CT and MRI (κ=–0.026; 95% confidence interval: –0.051, 0.000). The PABAK values were fair to high at each spinal level, which suggests that relatively low disease prevalence lowered the κ values. Together, the κ and PABAK values indicate that there is some degree of intermodality agreement, but that it is not consistent.CONCLUSIONOverall, facet joint signal change on fat-suppressed MRI did not always correlate with increased 99mTc-MDP SPECT/CT activity. MRI and 99mTc-MDP SPECT/CT for facet joint evaluation should not be considered interchangeable examinations in clinical practice or research
Communications Biophysics
Contains research objectives, summary of research and reports on three research projects.National Institutes of Health (Grant 5 PO1 GM14940-04)National Institutes of Health (Grant 5 TOl GM01555-04)National Aeronautics and Space Administration (Grant NGL 22-009-304
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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