2,240 research outputs found
Transient Expression of Tetrameric Recombinant Human Butyrylcholinesterase in Nicotiana benthamiana.
To optimize the expression, extraction and purification of plant-derived tetrameric recombinant human butyrylcholinesterase (prBChE), we describe the development and use of plant viral amplicon-based gene expression system; Tobacco Mosaic Virus (TMV) RNA-based overexpression vector (TRBO) to express enzymatically active FLAG-tagged plant made recombinant butyrylcholinesterase (rBChE) in Nicotiana benthamiana leaves using transient agroinfiltration. Two gene expression cassettes were designed to express the recombinant protein in either the ER or to the apoplastic compartment. Leaf homogenization was used to isolate ER-retained recombinant butyrylcholinesterase (prBChE-ER) while apoplast-targeted rBChE was isolated by either leaf homogenization (prBChE) or vacuum-extraction of apoplastic wash fluid (prBChE-AWF). rBChE from apoplast wash fluid had a higher specific activity but lower enzyme yield than leaf homogenate. To optimize the isolation and purification of total recombinant protein from leaf homogenates, an acidic extraction buffer was used. The acidic extraction buffer yielded >95% enzymatically active tetrameric rBChE as verified by Coomassie stained and native gel electrophoresis. Furthermore, when compared to human butyrylcholinesterase, the prBChE was found to be similar in terms of tetramerization and enzyme kinetics. The N-linked glycan profile of purified prBChE-ER was found to be mostly high mannose structures while the N-linked glycans on prBChE-AWF were primarily complex. The glycan profile of the prBChE leaf homogenates showed a mixture of high mannose, complex and paucimannose type N-glycans. These findings demonstrate the ability of plants to produce rBChE that is enzymatically active and whose oligomeric state is comparable to mammalian butyrylcholinesterase. The process of plant made rBChE tetramerization and strategies for improving its pharmacokinetics properties are also discussed
Interior noise reduction by alternate resonance tuning
Existing interior noise reduction techniques for aircraft fuselages perform reasonably well at higher frequencies, but are inadequate at low frequencies, particularly with respect to the low blade passage harmonics with high forcing levels found in propeller aircraft. A method is studied which considers aircraft fuselages lined with panels alternately tuned to frequencies above and below the frequency that must be attenuated. Adjacent panel would oscillate at equal amplitude, to give equal acoustic source strength, but with opposite phase. Provided these adjacent panels are acoustically compact, the resulting cancellation causes the interior acoustic modes to be cut off, and therefore be nonpropagating and evanescent. This interior noise reduction method, called Alternate Resonance Tuning (ART), is being investigated theoretically and experimentally. Progress to date is discussed
Recommended from our members
Detailed Visual Cortical Responses Generated by Retinal Sheet Transplants in Rats with Severe Retinal Degeneration.
To combat retinal degeneration, healthy fetal retinal sheets have been successfully transplanted into both rodent models and humans, with synaptic connectivity between transplant and degenerated host retina having been confirmed. In rodent studies, transplants have been shown to restore responses to flashes of light in a region of the superior colliculus corresponding to the location of the transplant in the host retina. To determine the quality and detail of visual information provided by the transplant, visual responsivity was studied here at the level of visual cortex where higher visual perception is processed. For our model, we used the transgenic Rho-S334ter line-3 rat (both sexes), which loses photoreceptors at an early age and is effectively blind at postnatal day 30. These rats received fetal retinal sheet transplants in one eye between 24 and 40 d of age. Three to 10 months following surgery, visually responsive neurons were found in regions of primary visual cortex matching the transplanted region of the retina that were as highly selective as normal rat to stimulus orientation, size, contrast, and spatial and temporal frequencies. Conversely, we found that selective response properties were largely absent in nontransplanted line-3 rats. Our data show that fetal retinal sheet transplants can result in remarkably normal visual function in visual cortex of rats with a degenerated host retina and represents a critical step toward developing an effective remedy for the visually impaired human population.SIGNIFICANCE STATEMENT Age-related macular degeneration and retinitis pigmentosa lead to profound vision loss in millions of people worldwide. Many patients lose both retinal pigment epithelium and photoreceptors. Hence, there is a great demand for the development of efficient techniques that allow for long-term vision restoration. In this study, we transplanted dissected fetal retinal sheets, which can differentiate into photoreceptors and integrate with the host retina of rats with severe retinal degeneration. Remarkably, we show that transplants generated visual responses in cortex similar in quality to normal rats. Furthermore, transplants preserved connectivity within visual cortex and the retinal relay from the lateral geniculate nucleus to visual cortex, supporting their potential application in curing vision loss associated with retinal degeneration
Known-groups validity of the Patient-Reported Outcomes Measurement Information System (PROMIS®) in adolescents and young adults with special healthcare needs
To examine known-groups validity of the Patient-Reported Outcomes Measurement Information System (PROMIS®) Short Forms (SFs) for adolescents and young adults with special health care needs (SHCN) using data collected from the PROMIS Linking Study
Responsiveness to Change in PROMIS
AbstractObjectiveTo compare the responsiveness to change of the Patient-Reported Outcomes Measurement Information System (PROMIS®) asthma impact, pain interference, fatigue, depressive symptoms, mobility, and peer relationship scales to a legacy scale, the Paediatric Asthma Quality of Life Questionnaire (PAQLQ).MethodsTwo hundred and twenty-nine child-parent dyads from public insurance programs were enrolled. PROMIS pediatric short forms (SFs) and the PAQLQ were used to measure health-related quality of life across four time points (T1–T4) over 2 years. The Asthma Control and Communication Instrument was used to measure the change in asthma control, and the Global Rating of Change (GRC) Index for breathing problems and overall health was used to measure the change in health status. Responsiveness was tested by comparing the changes in health-related quality of life with the changes in asthma control and health status over time using t tests, generalized estimating equations, and relative validity approaches. Magnitudes of the responsiveness between the Pediatric PROMIS and PAQLQ were assessed through statistical significance, Cohen's d effect size (ES), and standardized response mean (SRM).ResultsThe PROMIS asthma impact scale and all PAQLQ scales exhibited significant responsiveness (p'sConclusionsThe PROMIS asthma impact SF indicated similar responsiveness to the PAQLQ scales. Due to its brevity and responsiveness, the PROMIS asthma impact SF is useful for clinical practice or research
Understanding racial differences in health-related quality of life in a population-based cohort of breast cancer survivors
Although racial disparities in health-related quality of life (HRQOL) among women with breast cancer (BC) are well documented, less is known about HRQOL changes over time among women of different races. Our objective was to assess racial differences in HRQOL during active treatment and survivorship phases of BC care
Pathway to the PiezoElectronic Transduction Logic Device
The information age challenges computer technology to process an
exponentially increasing computational load on a limited energy budget - a
requirement that demands an exponential reduction in energy per operation. In
digital logic circuits, the switching energy of present FET devices is
intimately connected with the switching voltage, and can no longer be lowered
sufficiently, limiting the ability of current technology to address the
challenge. Quantum computing offers a leap forward in capability, but a clear
advantage requires algorithms presently developed for only a small set of
applications. Therefore, a new, general purpose, classical technology based on
a different paradigm is needed to meet the ever increasing demand for data
processing.Comment: in Nano Letters (2015
Longitudinal associations among asthma control, sleep problems, and health-related quality of life in children with asthma: a report from the PROMIS® Pediatric Asthma Study
Few studies have investigated the complex relationship among asthma control, sleep problems, and health-related quality of life (HRQOL) among children with asthma. This study aimed to test the longitudinal effect of asthma control status on asthma-specific HRQOL through the mechanism of nighttime sleep quality and daytime sleepiness
- …