bluuebunny/crossref_metadata_2025 huggingface dataset:
Human astrocytes express a novel NLRP2 inflammasome
Authors: Minkiewicz Julia , de Rivero Vaccari Juan Pablo , Keane Robert W.
Published: April 2013

Central nervous system (CNS) trauma involves extensive cellular damage that is due, in part, to an innate inflammatory response induced by extracellular ATP. The innate immune response is regulated by pattern recognition receptors (PRRs), which include NOD‐like receptors (NLRs). The PRRs and signaling cascades that regulate innate glial responses to CNS injury remain largely undefined. In this report, we show that human astrocytes express the NLR protein 2 (NLRP2) inflammasome that is activated by the danger associated molecular pattern (DAMP) ATP. The NLRP2 inflammasome is a multiprotein complex that consists of NLRP2, the adaptor protein apoptosis‐speck‐like protein containing a caspase recruitment domain (ASC) and caspase‐1. NLRP2 also interacts with the P2X7 receptor and the pannexin 1 channel. Stimulation of human astrocytes with ATP resulted in activation of the NLRP2 inflammasome leading to the processing of inflammatory caspase‐1 and interleukin‐1β (IL‐1β). ATP‐induced activation of the NLRP2 inflammasome was inhibited by the pannexin 1 inhibitor probenecid and by the P2X7 receptor antagonist Brilliant Blue G (BBG). siRNA knockdown of NLRP2 significantly decreased NLRP2 levels and caspase‐1 processing in human astrocytes in response to ATP. Our findings suggest that the astrocytic NLRP2 inflammasome is an important component of the CNS inflammatory response and that the NLRP2 inflammasome may be a therapeutic target to inhibit inflammation induced by CNS injury.
Rapid loss of firn pore space accelerates 21st century Greenland mass loss
Authors: van Angelen J. H. , M. Lenaerts J. T. , van den Broeke M. R. , Fettweis X. , van Meijgaard E.
Published: April 2013

Mass loss from the two major ice sheets and their contribution to global sea level rise is accelerating. In Antarctica, mass loss is dominated by increased flow velocities of outlet glaciers, following the thinning or disintegration of coastal ice shelves into which they flow. In contrast, ~55% of post‐1992 Greenland ice sheet (GrIS) mass loss is accounted for by surface processes, notably increased meltwater runoff. A subtle process in the surface mass balance of the GrIS is the retention and refreezing of meltwater, currently preventing ~40% of the meltwater to reach the ocean. Here we force a high‐resolution atmosphere/snow model with a mid‐range warming scenario (RCP4.5, 1970–2100), to show that rapid loss of firn pore space, by >50% at the end of the 21st century, quickly reduces this refreezing buffer. As a result, GrIS surface mass loss accelerates throughout the 21st century and its contribution to global sea level rise increases to 1.7 ±0.5 mm yr−1, more than four times the current value.
Sex differences in blood genotoxic and cytotoxic effects as a consequence of vanadium inhalation: micronucleus assay evaluation
Authors: Rojas‐Lemus Marcela , Altamirano‐Lozano Mario , Fortoul Teresa I.
Published: April 2013

ABSTRACT: Vanadium is an environmental pollutant attached to the smallest air suspended particles that enters into the respiratory tract reaching the systemic circulation. The oxidative state of this element and sex are factors related to its toxicity. In this study, we explored sex‐associated genotoxic and cytotoxic differences in a mouse experimental model. Mice inhaled V2O5 (0.02 M) 2 h/twice a week; blood samples were obtained at 24 h and every week until the end of the 4‐week exposure. Samples were processed for fluorochrome‐mediated viability and a micronucleus assay in slides pre‐covered with acridine orange (AO). The results showed that males were more susceptible to genotoxicity during the exposure in contrast to the females. In peripheral blood leukocytes, no cytotoxic differences were observed in both, females or males, but the decrease in circulating reticulocytes provides evidence of the metal's cytotoxic effect on the bone marrow (BM). A significant decrease in reticulocytes was observed during the experiment independent of the animal's sex. The present findings might be explained by the interaction of the metal with the enzymes that control erythropoiesis or a direct effect on erythropoietin production might explain our findings; however, an absence of the genotoxic effects in females could be a consequence of the protective effect against oxidative stress by their higher estrogen levels. This study contributes to a better understanding of the mechanisms by which vanadium induces adverse effects in biological systems. Copyright © 2013 John Wiley & Sons, Ltd.
Translucent titanium coating altered the composition of focal adhesions and promoted migration of osteoblast‐like MG‐63 cells on glass
Authors: Ho Yi , Kok Sang‐Heng , Wang Juo‐Song , Lin Li‐Deh
Published: April 2013

“TiGlass” was designed and was known to promote initial adhesion and increase migration of rat calvarial osteoblats. In this article, migration study and a series of epifluorescence microscopic studies were conducted to find out the composition of focal adhesion on titanium surface. The translucent titanium surface was applied in random migration analysis and immunofluorescence cell staining. In the immunofluorescent double staining, phosphorylated focal adhesion kinase was tested with vinculin. Various integrin subunits were then tested with vinculin to study the composition of activated focal adhesions. Integrin subunit α5 and αV were tested against β3; integrin subunits α5, αV, β3, and αVβ3 were tested with F‐actin, respectively. The MG‐63 cells began migration earlier and migrated faster on “TiGlass.” Immunofluorescent double staining revealed that all focal adhesion kinase in the focal adhesions were activated on both the surfaces. The osteoblast was inferred to made adhesion to titanium and glass through integrins. The focal adhesions on glass were found to be composed of integrin subunits αV and β3. However, on “TiGlass,” integrin subunits α5 might have supplemented the adhesion to titanium. Results from double staining of integrin subunits α5, αV, β3, and αVβ3 with F‐actin also supported integrin subunits α5 might have involved in adhesion of titanium. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1187–1201, 2014.
Local ultraviolet laser irradiation for gradients on biocompatible polymer surfaces
Authors: Nottrodt Nadine , Leonhäuser Dorothea , Bongard Yvonne , Bremus‐Köbberling Elke , Gillner Arnold
Published: April 2013

Generation of supporting structures, which guide cell growth, is a challenging task in the field of tissue engineering. Cell guidance properties of a scaffold are important in the field of neuronal regeneration. Those guiding structures can provide guidance just by mechanical stimulus or by chemical stimuli like cell signaling molecules. For an enhanced guidance, chemical gradients are under investigation. With this study, we show that ultraviolet laser irradiation is a useful tool to activate polymer surfaces with a high temporal and spatial resolution. We demonstrated that poly(methyl methacrylate) (PMMA) and poly‐ε‐caprolactone (PCL) can be locally activated and functionalized with amine groups that can be used for immobilization of arginine–glycine–aspartic acid (RGD) peptide. The immobilized RGD was detected by neuronal B35 cells. By defined pulse accumulation functionalization density on the surface can be varied for the generation of gradients. We demonstrated that PMMA and PCL have different process windows for functionalization. Although PMMA has a very small process window for activation, PCL allows the generation of stepwise functionalization. The presented technology can help to develop assays for the analysis of cell migration and neuronal regeneration due to flexible patterning easily realized by changing the irradiation parameters. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2014:102A:999–1007.
The extended Saturnian neutral cloud as revealed by global ENA simulations using Cassini/MIMI measurements
Authors: Dialynas K. , Brandt P. C. , Krimigis S. M. , Mitchell D. G. , Hamilton D. C. , Krupp N. , Rymer A. M.
Published: April 2013

We show that the neutral gas vertical distribution at Saturn must be ~3–4 times more extended than previously thought for the >5 RSregions, while the neutral H distribution is consistent with H densities that reach up to ~150/cm3close to the orbit of Titan. We utilize a technique to retrieve the global neutral gas distribution in Saturn's magnetosphere, using energetic ion and energetic neutral atom (ENA) measurements, obtained by the Magnetospheric Imaging Instrument (MIMI) onboard the Cassini spacecraft. Our ENA measurements are consistent with a neutral cloud that consists of H2O, OH, H, and O, while the overall shapes and densities numbers concerning the neutral gas distributions are constrained according to already existing models as well as recent observations. The neutral gas distribution at Saturn is determined by simulating a 24–55 keV hydrogen image of the Saturnian magnetosphere, measured by the Ion and Neutral Camera (INCA), averaged over the time period from 1 July 2004 to 23 August 2005. The ionic input of the model includes a proton distribution of combined Charge Energy Mass Spectrometer (CHEMS, 3–230 keV/e), Low Energy Magnetospheric Measurements System (LEMMS, 30.7 keV to 2.3 MeV), and INCA (5–300 keV) in situ measurements. These measurements cover several passes from 1 July 2004 to 10 April 2007, at various local times over the dipole L range 5< L <20RS. A parameterized neutral gas distribution is changed until agreement between the simulated and average INCA image is obtained.
On the nature of GPS draconitic year periodic pattern in multivariate position time series
Authors: Amiri‐Simkooei A. R.
Published: April 2013

Plate tectonics studies using GPS require proper analysis of time series, in which all functional effects are understood and all stochastic effects are captured using an appropriate noise assessment technique. Both issues are addressed in this contribution. Estimates of spatial correlation, time correlated noise, and multivariate power spectrum for daily position time series of 350, 150, and 50 permanent GPS stations, respectively, collected between 2000–2007, 1998–2007, and 1996–2007 are obtained. The daily GPS global solutions were processed by the GPS Analysis Center at JPL. The detection power of the common‐mode signals is improved by including the time‐ and space‐correlated noise into the least squares power spectrum. Previous signals, such as those with periods of 13.63, 14.2, 14.6, and 14.8 days, are identified in the multivariate analysis. Significant signal with period of 351.6 ± 0.2 days and its higher harmonics are detected in the series, which closely follows the GPS draconitic year. The variation range of this periodic pattern for the north, east, and up components are about ±3, ±3.2, and ±6.5 mm, respectively. Three independent criteria confirm that this periodic pattern is of similar nature at adjacent stations, indicating its independence of the station‐related effects such as multipath. It is likely due to the other causes of the GPS draconitic year period driven into GPS time series. The multivariate power spectrum shows a cluster of signals with periods ranging from 5 to 6 days (quasiperiodic signals). In their aliased forms, the effects are likely partly responsible for the time‐correlated noise and partly for the periodic patterns at lower frequencies.
Off‐resonance insensitive complementary SPAtial Modulation of Magnetization (ORI‐CSPAMM) for quantification of left ventricular twist
Authors: Reyhan Meral , Natsuaki Yutaka , Ennis Daniel B.
Published: April 2013

Purpose

To evaluate Off Resonance Insensitive Complementary SPAtial Modulation of Magnetization (ORI‐CSPAMM) and Fourier Analysis of STimulated echoes (FAST) for the quantification of left ventricular (LV) systolic and diastolic function and compare it with the previously validated FAST+SPAMM technique.

Materials and Methods

LV short‐axis tagged images were acquired with ORI‐CSPAMM and SPAMM in healthy volunteers (n = 13). The FAST method was used to automatically estimate LV systolic and diastolic twist parameters from rotation of the stimulated echo and stimulated anti‐echo about the middle of k‐space subsequent to ∼3 min of user interaction.

Results

There was no significant difference between measures obtained for FAST+ORI‐CSPAMM and FAST+SPAMM for mean peak twist (12.9 ± 3.4° versus 11.9 ± 4.0°; P = 0.4), torsion (3.3 ± 0.9°/cm versus 2.9 ± 1.0°/cm, P = 0.3), circumferential–longitudinal shear angle (9.1 ± 3.0° versus 8.2 ± 3.4°, P = 0.3), twisting rate (79.6 ± 20.2°/s versus 68.2 ± 23.4°/s, P = 0.1), untwisting rate (−117.5 ± 31.4°/s versus −106.6 ± 32.4°/s, P = 0.3), normalized untwisting rate (−9.3 ± 2.0/s versus −9.9 ± 4.4/s, P = 0.7), and time of peak twist (281 ± 18 ms versus 293 ± 25 ms, P = 0.04). FAST+ORI‐CSPAMM also provided measures of duration of untwisting (148 ± 21 ms) and the ratio of rapid untwisting to peak twist (0.9 ± 0.3). Bland‐Altman analysis of FAST+ORI‐CSPAMM and FAST+SPAMM twist data demonstrates excellent agreement with a bias of −0.1° and 95% confidence intervals of (−1.0°, 3.2°).

Conclusion

FAST+ORI‐CSPAMM is a semi‐automated method that provides a quick and quantitative assessment of LV systolic and diastolic twist and torsion. ORI‐CSPAMM corrects off‐resonance accrued during tagging preparation and readout and visibly removes chemical shift from the tagging pattern, which confers greater robustness to the derived quantitative measures. J. Magn. Reson. Imaging 2014;39:339–345. © 2013 Wiley Periodicals, Inc.
Functional testing provides unique insights into the pathomechanics of femoroacetabular impingement and an objective basis for evaluating treatment outcome
Authors: Rylander Jonathan , Shu Beatrice , Favre Julien , Safran Marc , Andriacchi Thomas
Published: April 2013

Femoroacetabular impingement (FAI) has been recognized as a significant clinical problem. While hip reshaping surgery for treating FAI has had positive clinical outcomes, there remains a need for objective functional outcomes of FAI treatment. We tested the hypothesis that during walking and stair climbing significant changes in hip kinematics would occur following hip reshaping surgery that indicate restoration of normal function post‐operatively. Hip and pelvic kinematics were collected for 17 FAI patients pre‐ and 1 year post‐operatively and compared to 17 healthy matched controls. Prior to surgery, FAI patients had significantly reduced hip internal rotation and hip sagittal plane range of motion during walking (p = 0.01, p < 0.001, respectively) and stair climbing (p = 0.01, p < 0.001, respectively) as compared with controls. Post‐operatively, these motions were restored to normal during walking (p = 0.70, p = 0.46, respectively), but remained significantly reduced in the FAI patients during stair climbing (p = 0.03, p < 0.001, respectively). These results have important implications for understanding the functional pathomechanics of FAI and providing an objective basis for evaluating treatment outcome. The stair climbing results indicate that problems still exist in the hip joint for activities requiring higher ranges of hip motion and suggest a basis for exploring future improvements for the treatment of FAI. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1461–1468, 2013
The frequency response of a floating piezoelectric microphone for the implantable middle ear microphone
Authors: Gao Na , Chen Yong Zheng , Chi Fang Lu , Zhang Tian Yu , Xu Hai Dong , Kang Hou Yong , Pan Tie Zheng
Published: April 2013

Objectives/Hypothesis

A piezoelectric sensor, floating piezoelectric microphone, driven by acoustic vibration of the ossicles, is one possible design for a microphone for a totally implantable cochlear implant. The purpose of the article was to study the frequency response of the floating piezoelectric microphone and to identify the ideal feasible position in the ossicular chain.

Study Design

Basic Research.

Methods

The frequency response of the floating piezoelectric microphone was analyzed by finite‐element modeling and in vitro testing of fresh cadaveric heads. The floating piezoelectric microphone, 5.0 mm in length and 1.5 mm by 1.2 mm in rectangular cross section, as a piezoelectric microphone, was placed at various locations on the ossicular chain and stimulated by pure tones of different frequencies.

Results

The floating piezoelectric microphone can pick up the vibration of the ossicular chain and effectively convert it into the electronic signals effectively both in the long process of incus and in the malleus. The average sensitivity of the FPM is −44.22 dB rms ref 1V at 1000Hz in the long process of incus, −53.33 dB rms ref 1V at 1000Hz in the malleus, and −108.59 dB rms ref 1V at 1000Hz in the tympanic cavity.

Conclusions

The floating piezoelectric microphone is expected to be used as an implantable middle ear microphone for the totally implantable cochlear implant.

Level of Evidence

N/A.
Regenerative process of tracheal epithelium using a collagen vitrigel sponge scaffold
Authors: Tani Akiko , Tada Yasuhiro , Takezawa Toshiaki , Wada Ikuo , Imaizumi Mitsuyoshi , Nomoto Yukio , Nomoto Mika , Omori Koichi
Published: April 2013

Objectives/Hypothesis

Our group has developed a collagen vitrigel sponge scaffold containing basic fibroblast growth factor (b‐FGF) for tracheal reconstruction. In this study, we have investigated the regenerative process of tracheal epithelium histologically and morphologically.

Study Design

A preliminary animal experiment.

Methods

A collagen vitrigel sponge scaffold was fabricated with simultaneous addition of 100 ng b‐FGF. Tracheotomies were performed, and collagen vitrigel sponge scaffolds were implanted on tracheal defects in rats. At 5, 7, and 14 days after implantation, the intraluminal surface of the regenerated tracheae was observed using endoscope. Histological examination of the intraluminal regenerated trachea was performed using light microscope and scanning electron microscope.

Results

Endoscopic images showed epithelial regeneration at 7 days after implantation. Light microscopic examination detected stratified epithelium at 5 days, columnar cells at 7 days, and ciliated cells at 14 days after implantation. Scanning electron microscopy images showed regenerated epithelial cells at 5 and 7 days, and ciliated cells at 14 days after implantation.

Conclusions

The horizontal section and luminal area of the regenerated epithelium were investigated. The epithelium was formed at 5 days, and mature cilia were found at 14 days after implantation. Epithelium of equality equivalent to normal trachea was regenerated in a rat model with collagen vitrigel‐scaffold containing b‐FGF at 14 days.

Level of Evidence

N/A.
Primary embryonal rhabdomyosarcoma of the anterior neck and thyroid
Authors: Dutta Mainak , Chatterjee Indranil , Roy Soham , Gure Prasanta Kumar
Published: April 2013

Primary embryonal rhabdomyosarcoma of anterior neck involving the thyroid is extremely rare. This report is only the second of its kind that describes this form of nonorbital nonparameningeal rhabdomyosarcoma in a 7‐year‐old boy and adds to a new, seldom‐reported variant of rhabdomyosarcoma in the head‐neck region. The child presented with a huge anterior neck swelling that clinically resembled a thyroid mass. Computed tomography scan showed a heterogeneous mass in the anterior neck replacing the entire right lobe of thyroid. Fine‐needle aspiration cytology was nondiagnostic. Right hemithyroidectomy with selective neck dissection suggested embryonal rhabdomyosarcoma by histopathology; the diagnosis was confirmed by positive reactions to desmin and myogenin. The child was subsequently treated with chemotherapy. Repeat chemotherapy with radiotherapy was required when recurrences were detected in the mediastinum and cervical lymph nodes at 13‐month follow‐up.

Laryngoscope, 123:2072–2076, 2013
Serine substitution of proline at codon 151 of TP53 confers gain of function activity leading to anoikis resistance and tumor progression of head and neck cancer cells
Authors: Xie Tong‐Xin , Zhou Ge , Zhao Mei , Sano Daisuke , Jasser Samar A. , Brennan Richard G. , Myers Jeffrey N.
Published: April 2013

Objectives/Hypothesis

Mutation of the TP53 gene occurs in more than half of cases of head and neck squamous cell carcinoma (HNSCC). However, little is known about how specific TP53 mutations affect tumor progression. The objective of this study is to determine the gain of function of mutant p53 with a proline‐to‐serine substitution at codon 151.

Study Design

Laboratory‐based study.

Methods

A panel of HNSCC cell lines was determined with anoikis assays, and orthotopic mouse experiments were performed. TP53 was sequenced. The shRNA knockdown and overexpression approaches were used for testing mutant p53 functions. The crystal structure of the p53 protein was analyzed using an in silico approach.

Results

An anoikis‐resistant cell line, Tu138, was found to have a proline‐to‐serine substitution at codon 151 of TP53, which results in loss of wild‐type p53 transcriptional activity. Moreover, the mutant p53 was shown to promote anoikis resistance and soft agar growth. Using an in silico approach based on the crystal structure of wild‐type p53 protein, substitution of proline by serine at position 151 would create a cavity in a hydrophobic pocket, the loss of van der Waals contacts, and the thermodynamically unfavorable placement of a polar group, the hydroxyl oxygen atom of the serine, within a hydrophobic region, all of which likely cause a locally altered structure.

Conclusions

Our data suggest that mutation at position 151 leads to a structural alteration, which results in significant functional changes in the p53 protein that impact tumor progression.
Taste intensity in the Beaver Dam Offspring Study
Authors: Fischer Mary E. , Cruickshanks Karen J. , Schubert Carla R. , Pinto Alex , Klein Barbara E. K. , Klein Ronald , Nieto F. Javier , Pankow James S. , Huang Guan‐Hua , Snyder Derek J.
Published: April 2013

Objectives/Hypothesis

To determine the distribution of the perceived intensity of salt, sweet, sour, and bitter in a large population and to investigate factors associated with perceived taste intensity.

Study Design

Cross‐sectional population.

Methods

Subjects (n = 2,374; mean age, 48.8 years) were participants in the Beaver Dam Offspring Study examined during 2005 to 2008. Perceived taste intensity was measured using paper disks and a general labeled magnitude scale. Multiple linear regression was performed.

Results

Mean intensity ratings were: salt = 27.2 (standard deviation [SD] = 18.5), sweet = 20.4 (SD = 15.0), sour = 35.7 (SD = 21.4), and bitter = 49.6 (SD = 23.3). Females and those with less than a college degree education rated tastes stronger. With adjustment for age, sex, and education, stronger perceived sour and bitter intensities were related to current smoking (sour: B = 2.8, 95% confidence interval [CI], 0.4 to 5.2; bitter: B = 2.8, 95% CI, 0.3 to 5.4) and lipid‐lowering medications (sour: B = 5.1, 95% CI, 2.5 to 7.6; bitter: B = 3.2, 95% CI, 0.6 to 5.8). Alcohol consumption in the past year was related to weaker salt (B = −2.8, 95% CI, −5.3 to −0.3) and sweet intensity ratings (B = −2.3, 95% CI, −4.3 to −0.3), whereas olfactory impairment was associated with higher sweet ratings (B = 4.7, 95% CI, 1.4 to 7.9).

Conclusions

Perceived intensities were strongest for bitter and weakest for sweet. Sex and education were associated with each taste, whereas age did not demonstrate a consistent relationship. Associations with other factors differed by tastants, with current smoking and alcohol consumption being related to some tastes.

Level of Evidence

2b.
Histologic comparison of vocal fold microflap healing with sutures and glue
Authors: Maunsell Rebecca C. K. , de Freitas Leandro L. , Altemani Albina , Crespo Agrício N.
Published: April 2013

Objectives/Hypothesis

Improved voice quality is the expected outcome of microphonosurgery. To this end, the complex vibratory movement of the vocal folds must be preserved. Scarring of the vocal folds may compromise vocal outcome and is one of the most difficult to treat conditions. To minimize scar formation, a consensus exists on the need for maximum preservation of the epithelium and superficial lamina propria, and minimal exposure of vocal ligament. However, the need to cover the microflap defect is controversial. The aim of this study was to compare healing characteristics of microflap technique when the microflap is left to heal by second intention, when the defect is closed with sutures, and when it is covered with glue.

Study Design

Experimental animal study.

Material and Methods

An experimental study comparing the three techniques was carried out on 37 New Zealand rabbits. Vocal fold healing was evaluated 7, 30, and 90 days after surgical intervention. Collagen concentration, inflammatory reaction, epithelium, and lamina propria thickness were evaluated.

Results

Collagen concentration significantly increased in all groups. After 7 days, epithelium thickness significantly increased and lamina propria thickness was not significantly altered. At 90 days, only the suture group showed no significant alteration in epithelium thickness. After 90 days, lamina propria thickness decreased, except in the fibrin glue group. No difference was seen in the number of inflammatory cells among the techniques.

Conclusions

The use of microsutures or fibrin glue to close microflap defects did not consistently improve vocal fold healing nor produce better scarring results when compared to healing by second intention.

Level of Evidence

N/A. Laryngoscope, 2012
Delayed lower cranial neuropathies following primary radiotherapy for oropharyngeal squamous cell carcinoma
Authors: Huang Andrew T. , Song Shiyu , Dominguez Laura M. , Nguyen Josephine , Goldman Richard A. , Reiter Evan R.
Published: April 2013

Objectives/Hypothesis

Delayed lower cranial neuropathy is a rare complication following primary radiotherapy for head and neck cancer, and has been most associated with nasopharyngeal carcinoma with minimal data regarding this outcome in the treatment of the oropharynx. No reports, to the authors' knowledge, have described this complication following intensity modulated radiation therapy (IMRT) for oropharyngeal primaries. Once encountered, this adverse outcome can have serious impacts on speech and swallowing. We present here our institution's experience with delayed cranial neuropathies following primary radiation therapy for oropharyngeal squamous cell carcinoma, as well as document the only reported case following IMRT.
808 nm Wavelength Light Induces a Dose‐Dependent Alteration in Microglial Polarization and Resultant Microglial Induced Neurite Growth
Authors: von Leden Ramona E. , Cooney Sean J. , Ferrara Teresa M. , Zhao Yujia , Dalgard Clifton L. , Anders Juanita J. , Byrnes Kimberly R.
Published: April 2013

Background and Objective

Despite the success of using photobiomodulation (PBM), also known as low level light therapy, in promoting recovery after central nervous system (CNS) injury, the effect of PBM on microglia, the primary mediators of immune and inflammatory response in the CNS, remains unclear. Microglia exhibit a spectrum of responses to injury, with partial or full polarization into pro‐ and anti‐inflammatory phenotypes. Pro‐inflammatory (M1 or classically activated) microglia contribute to chronic inflammation and neuronal toxicity, while anti‐inflammatory (M2 or alternatively activated) microglia play a role in wound healing and tissue repair; microglia can fall anywhere along this spectrum in response to stimulation.

Materials and Methods

The effect of PBM on microglial polarization therefore was investigated using colorimetric assays, immunocytochemistry, proteomic profiling and RT‐PCR in vitro after exposure of primary microglia or BV2 microglial cell line to PBM of differing energy densities (0.2, 4, 10, and 30 J/cm2, 808 nm wavelength, 50 mW output power).

Results

PBM has a dose‐dependent effect on the spectrum of microglial M1 and M2 polarization. Specifically, PBM with energy densities between 4 and 30 J/cm2 induced expression of M1 markers in microglia. Markers of the M2 phenotype, including CD206 and TIMP1, were observed at lower energy densities of 0.2–10 J/cm2. In addition, co‐culture of PBM or control‐treated microglia with primary neuronal cultures demonstrated a dose‐dependent effect of PBM on microglial‐induced neuronal growth and neurite extension.

Conclusion

These data suggest that the Arndt–Schulz law as applied to PBM for a specific bioassay does not hold true in cells with a spectrum of responses, and that PBM can alter microglial phenotype across this spectrum in a dose‐dependent manner. These data are therefore of important relevance to not only therapies in the CNS but also to understanding of PBM effects and mechanisms. Lasers Surg. Med. © 2013 Wiley Periodicals, Inc.
Operator Independent Focused High Frequency ISM Band for Fat Reduction: Porcine Model
Authors: Weiss Robert , Weiss Margaret , Beasley Karen , Vrba Jan , Bernardy Jan
Published: April 2013

Background

Selective fat reduction has been clearly shown for various methods and energy modalities including cryolipolysis and high intensity focused thermal ultrasound. Mathematical modeling of focused high frequency of the EM spectrum has indicated that selective heating of fat is possible using wavelengths not previous explored. The purpose of this study was to demonstrate in the porcine model that selective heating of fat is possible with a non‐contact, operator independent device.

Methods

High frequencies of the Industrial, Scientific and Medical (ISM) RF band were utilized to reduce abdominal fat in a porcine model. Practical application of mathematical modeling allowed an auto‐feedback loop to be developed to allow operator independent adjustment of energy to maintain subcutaneous fat at 45–46°C while overlying skin remained at 40–41°C.

Results

Treatments of three Vietnamese pigs were performed under anesthesia in a certified veterinary facility. Gross and microscopic histologic results demonstrated a marked reduction in adipocytes of the treated area after 4 treatments of a total of 30 minutes each, with incremental fat diminution after each treatment. A final 70% reduction of the abdominal fat layer was seen in the treated areas. Duplex ultrasound revealed a reduction of fat layer from 7.6 to 2.9 mm. Histologic evaluation revealed that epidermis, dermis, and adnexal structures such as hair follicles were unaffected by the treatment, while adipocytes were significantly affected.

Conclusion

A new model of fat reduction using high frequency RF has been successfully achieved in a porcine model. This has very positive implications in the development of an operator independent, contact free device for reduction of fat in clinical practice. Lasers Surg. Med. © 2013 Wiley Periodicals, Inc.
Minimally Invasive Bipolar Fractional Radiofrequency Treatment Upregulates Anti‐Senescence Pathways
Authors: Rangarajan Sachin , Trivedi Apexa , Ubeid Anan Abu , Hantash Basil M.
Published: April 2013

Background

The sirtuin gene family has been implicated in various anti‐senescence pathways. Its connection, if any, with the skin wound healing response has yet to be elucidated.

Objective

The goal of our study was to better understand the effects of FRF treatment on the sirtuin anti‐senescence pathway in skin.

Methods

Human abdominal skin was treated with FRF, and then harvested at 0, 2, 14, and 28 days post‐treatment to assess for temporal changes in gene expression levels.

Results

Decreased levels of SIRT1, 3, 5, and 7 were observed immediately post‐FRF treatment. By Day 2, SIRT1, 6, and 7 expressions increased 50–100%. SIRT6 and 7 expression continued to increase through Day 28. Expression levels of apoptosis genes FoxO3 and p53 decreased, while Bax levels increased by Day 28.

Conclusions

Our results raise the possibility that sirtuin activity may be used as an accurate corollary to clinical improvement in skin quality. Lasers Surg. Med. 9999:XX–XX, 2013. © 2013 Wiley Periodicals, Inc.
A Light Emitting Diode (LED) Based Spatial Frequency Domain Imaging System for Optimization of Photodynamic Therapy of Nonmelanoma Skin Cancer: Quantitative Reflectance Imaging
Authors: Saager R. B. , Cuccia D. J. , Saggese S. , Kelly K. M. , Durkin A. J.
Published: April 2013

Background

Photodynamic therapy (PDT) offers the potential for enhanced treatment of nonmelanoma skin cancer (NMSC) with minimal scarring. Yet, PDT has not achieved consistent long term effectiveness to gain widespread clinical acceptance for treatment of skin cancer. Therapeutic response varies between practitioners, patients and lesions. One important contributing factor is the absence of quantitative tools to perform in vivo dosimetry. To this end, we have developed a new quantitative imaging device that can be used to investigate parameters related to optimizing dosimetry.

Methods

We present a spatial frequency domain imaging (SFDI) based device designed to: (1) determine the optical properties at the therapeutic wavelength, which can inform variations in light penetration depth and (2) measure the spatially resolved oxygen saturation of the skin cancer lesions and surrounding tissue. We have applied this system to a preliminary clinical study of nine skin cancer lesions.

Results

Optical properties vary greatly both spatially [101%, 48% for absorption and reduced scattering, respectively] and across patients [102%, 57%]. Blood volume maps determined using visible wavelengths (460, 525, and 630 nm) represent tissue volumes within ∼1 mm in tissue (1.17 ± 0.3 mm). Here the average total hemoglobin concentration is approximately three times greater in the lesion than that detected in normal tissue, reflecting increased vasculature typically associated with tumors. Data acquired at near infrared wavelengths (730 and 850 nm) reports tissue blood concentrations and oxygenations from the underlying dermal microvasculature (volumes reaching 4.36 ± 1.32 mm into tissue).

Conclusions

SFDI can be used to quantitatively characterize in vivo tissue optical properties that could be useful for better informing PDT treatment parameters. Specifically, this information provides spatially resolved insight into light delivery into tissue and local tissue oxygenation, thereby providing more quantitative and controlled dosimetry specific to the lesion. Ultimately, by optimizing the execution of PDT, this instrument has the potential to positively improve treatment outcomes. Lasers Surg. Med. 9999:XX–XX, 2013. © 2013 Wiley Periodicals, Inc.
Polyaniline–Polypyrrole Composites with Enhanced Hydrogen Storage Capacities
Authors: Attia Nour F. , Geckeler Kurt E.
Published: April 2013

A facile method for the synthesis of polyaniline–polypyrrole composite materials with network morphology is developed based on polyaniline nanofibers covered by a thin layer of polypyrrole via vapor phase polymerization. The hydrogen storage capacity of the composites is evaluated at room temperature exhibits a twofold increase in hydrogen storage capacity. The HCl‐doped polyaniline nanofibers exhibit a storage capacity of 0.46 wt%, whereas the polyaniline–polypyrrole composites could store 0.91 wt% of hydrogen gas. In addition, the effect of the dopant type, counteranion size, and the doping with palladium nanoparticles on the storage properties are also investigated.

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Smart Molecularly Imprinted Polymers: Recent Developments and Applications
Authors: Ge Yi , Butler Benjamin , Mirza Farhan , Habib‐Ullah Sabeeh , Fei Dan
Published: April 2013

The use of the molecular imprinting technique to produce polymers with high specificity for a given “molecular template” has undergone a rapid and expansive evolution since the inception of the idea over half a century ago. It was only a matter of time before the seemingly inevitable “marriage” of this concept with another modern research obsession, the generation of “smart” polymers, capable of reacting quickly, accurately and reproducibly to changes in their environment. Many advances have since been made, concerning the quality and diversity of these systems and polymers responsive to temperature, pH and a host of other environmental cues now exist. This article provides a succinct overview of the process and outcomes of “smart” molecular imprinting, followed by a detailed assessment of recent developments and applications in such field.

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The role of ERK2 in colorectal carcinogenesis is partly regulated by TRAPPC4
Authors: Weng Yu‐Rong , Kong Xuan , Yu Ya‐Nan , Wang Ying‐Chao , Hong Jie , Zhao Shu‐Liang , Fang Jing‐Yuan
Published: April 2013

The extracellular signal‐regulated kinase (ERK), mitogen‐activated protein kinase (MAPK) pathway is an important cell proliferation pathway. We previously reported that the transport protein particle complex 4 (TRAPPC4), ERK2 interaction may activate ERK1/2, modulate pERK2 nuclear localization and regulate proliferation and apoptosis in colorectal cancer (CRC) cells. The present study further investigated the function of the TRAPPC4–ERK2 interaction in CRC in vitro and in vivo. Silencing of TRAPPC4 induced G0/G1 phase cell cycle arrest, upregulated p21 and downregulated cyclin B1 in CRC cells. Overexpression of TRAPPC4 after ERK2 silencing decreased the percentage of G0/G1 phase cells, increased the percentage of G2/M and S phase cells, downregulated p21, upregulated cyclin B1, and enhanced CRC cell viability. Immunohistochemical staining revealed that knockdown of TRAPPC4 downregulated pERK2, whereas overexpression of TRAPPC4 upregulated pERK2. Epidermal growth factor (EGF) stimulated upregulation of TRAPPC4 and pERK2 in SW1116 cells; EGF stimulation or overexpression of TRAPPC4 induced pERK2 nuclear translocation. Silencing of TRAPPC4 reduced SW1116 xenograft tumor growth in vivo, whereas overexpression of TRAPPC4 increased tumor growth, compared to control tumors. Moreover, modulation of TRAPPC4 expression in vivo affected the levels of pERK2 in the cytoplasm and nucleus and expression of p21. These results conclusively demonstrate that TRAPPC4 regulates ERK2 activation and also affects the distribution of activated pERK2 in CRC cells. The ability of ERK2 to play a role in colorectal carcinogenesis depends, at least in part, on TRAPPC4. © 2013 Wiley Periodicals, Inc.
Numerical solutions of the coupled Burgers’ equation by the Galerkin quadratic B‐spline finite element method
Authors: Kutluay S. , Ucar Y.
Published: April 2013

In this paper, a coupled Burgers’ equation has been numerically solved by a Galerkin quadratic B‐spline FEM. The performance of the method has been examined on three test problems. Results obtained by the method have been compared with known exact solution and other numerical results in the literature. A Fourier stability analysis of the method is also investigated. Copyright © 2013 John Wiley & Sons, Ltd.
Low‐power photonic control of a microwave ring resonator using bulk illumination
Authors: Shirazi‐Hosseinidokht Mohammad Ali , Hossein‐Zadeh Mani
Published: April 2013

We demonstrate the feasibility of bulk illumination technique for low‐power photonic control of RF resonance.Using this technique, the transmitted RF power through a microstripline‐ring filter on a junction‐less silicon substrate is changed by 11 dB with less than 2 mW of interacting optical power. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1594–1599, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27606
Sparse scatterers imaging through approximated multitask compressive sensing strategies
Authors: Viani Federico , Poli Lorenzo , Oliveri Giacomo , Robol Fabrizio , Massa Andrea
Published: April 2013

In the framework of the multitask Bayesian compressive sensing (BCS) paradigm, two innovative approaches for the solution of coherent imaging problems are proposed within the first‐order Born approximation and the Rytov approximation.Selected numerical results are reported to compare the proposed techniques with state‐of‐the‐art BCS approaches as well as global optimization‐based methods. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1553–1558, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27612
Miniaturization and isolation improvement of a multiple‐patch antenna system using electromagnetic bandgap structures
Authors: Suntives Asanee , Abhari Ramesh
Published: April 2013

In this article, a compact multielement antenna system composing of microstrip patch antennas is designed by using electromagnetic bandgap (EBG) structures. Two distinct EBG structures are designed to achieve the two objectives of miniaturization and suppression of interelement coupling due to surface waves in a multiantenna system. By embedding an EBG array operating in the slow‐wave region, the area of the microstrip patch antenna is reduced by 67.48%. To alleviate the resulting increased back radiation, a second EBG structure is designed to surround the miniaturized patch antenna and close to 8 dB improvement in the front‐to‐back lobe ratio is achieved. As well, the second EBG design is included in a 2 × 2 multiantenna system to suppress interelement coupling. It is found that the coupling is reduced significantly when utilizing the proposed EBG rings. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1609–1612, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27621
A dual‐band wide‐angle polarization‐insensitive ultrathin gigahertz metamaterial absorber
Authors: Zhai Huiqing , Li Zhenhua , Li Long , Liang Changhong
Published: April 2013

In this research, a dual‐band ultrathin metamaterial absorber with wide‐angle and polarization‐insensitive characteristic is presented. The metamaterial absorbers consist of a periodic arrangement of two scales of Jerusalem resonators and a metallic background plane, separated by only 0.8 mm dielectric spacer. By changing the direction of polarization, we achieve that the structure is polarization insensitive. Simulations demonstrate two good absorption rates in the designed frequency bands over wide angles of incident waves for both transverse electric and magnetic polarizations. Waveguide experiments are conducted to verify that the proposed designs can achieve two good absorptivity peaks. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1606–1609, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27622
Experimental research of surface plasmon polaritons waveguide filter in microwave band
Authors: Wang Wusong , Zhang Liwei , Jia Ran , Zhang Yewen
Published: April 2013

Based on theoretical analysis and experiments, the low‐pass filter effects of the μ‐negative materials/double positive materials/μ‐negative materials (MNG‐DPS‐MNG) surface plasmon polaritons waveguide are studied by using L‐C loaded transmission line structures in microwave band. It is shown that the pass‐band width of the waveguide is not determined by its size but the effective permeability in MNG materials. So it can be used to realize the small size and tunable low‐pass filter. The experimental results are in good agreement with results of simulations. These properties will have potential application values in the miniature and tunable low‐pass filters. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1531–1533, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27627
A four‐channel parallel 40 Gb/s laser diode voltage driver in 0.18‐μm CMOS
Authors: Yingmei Chen , Dawei Zai , Li Zhang , Wei Li
Published: April 2013

This article describes the design of a four‐channel parallel 40 Gb/s laser diode voltage driver (LDVD) circuit using 0.18‐μm CMOS technology.The LDVD circuit consists of input buffer stage, preamplifier stage, and output driver stage. The LDVD uses dual power supplies, including the 1.8‐V supply in the preamplifier stage and the 3.5‐V supply in the output driver stage. To increase the bandwidth, the preamplifier stage is made up of two‐stage cascaded differential amplifiers. The output driver circuit uses the RC negative feedback and capacitively coupled current amplifier (C3A) structure to speed up the operation of laser diode. The isolation has been carefully taken to avoid the cross‐talk issues among channels. Experimental results show that each channel of the LDVD can work at 10 Gb/s rate, and the output current swing is over 10 mA. The total power dissipation is 450 mW, and the chip area is 460 × 1230 μm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1540–1543, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27635
A compact two‐way equal power divider with enhanced out‐of‐band rejection based on SIW technology
Authors: Chen Shiyong , Su Chengfei , Yu Yantao , Wu Yucheng
Published: April 2013

A compact two‐way equal power divider with improved out‐of‐band rejection based on substrate‐integrated waveguide technology is presented in this letter.The proposed power divider with 4.3‐GHz center frequency and 38% fractional bandwidth has been designed, fabricated, and measured. The measured results show that the insertion losses are about 3.7 ± 0.5 dB, and the input return loss is greater than 10.6 dB in the pass band, which are in good agreement with the simulated data. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1638–1640, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27641
Novel bandpass‐response power divider with high frequency selectivity using centrally stub‐lOaded resonators
Authors: Song Kaijun , Hu Shunyong , Mo Yuxia , Fan Yong , Zhong Cuilin
Published: April 2013

This article presents a novel bandpass‐response power divider with high frequency selectivity. The centrally stub‐loaded resonators are applied to this power divider in order to provide bandpass‐filtering frequency response. In addition, the presented power divider has three transmission zeros, which can be used to improve the frequency selectivity. The measured results demonstrate the good performance of the fabricated bandpass‐response power divider with high selectivity. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1560–1562, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27644
Schwann cells seeded in acellular nerve grafts improve functional recovery
Authors: Jesuraj Nithya J. , Santosa Katherine B. , Macewan Matthew R. , Moore Amy M. , Kasukurthi Rahul , Ray Wilson Z. , Flagg Eric R. , Hunter Daniel A. , Borschel Gregory H. , Johnson Philip J. , Mackinnon Susan E. , Sakiyama‐Elbert Shelly E.
Published: April 2013

Introduction: This study evaluated whether Schwann cells (SCs) from different nerve sources transplanted into cold‐preserved acellular nerve grafts (CP‐ANGs) would improve functional regeneration compared with nerve isografts. Methods: SCs isolated and expanded from motor and sensory branches of rat femoral and sciatic nerves were seeded into 14mm CP‐ANGs. Growth factor expression, axonal regeneration, and functional recovery were evaluated in a 14‐mm rat sciatic injury model and compared with isografts. Results: At 14 days, motor or sensory‐derived SCs increased expression of growth factors in CP‐ANGs versus isografts. After 42 days, histomorphometric analysis found CP‐ANGs with SCs and isografts had similar numbers of regenerating nerve fibers. At 84 days, muscle force generation was similar for CP‐ANGs with SCs and isografts. SC source did not affect nerve fiber counts or muscle force generation. Conclusions: SCs transplanted into CP‐ANGs increase functional regeneration to isograft levels; however SC nerve source did not have an effect. Muscle Nerve 49: 267–276, 2014