213 research outputs found
Tag-probe labeling methods for live-cell imaging of membrane proteins
Instead of using reconstituted proteoliposomes, in situ investigations of membrane proteins in living cell membranes are important because the heterogeneous and dynamic nature of biomembranes significantly affects their behavior. Protein-specific labeling is a key technique for the detection of a target protein by fluorescence measurements, particularly fluorescence microscopy. However, conventional genetic fusion with fluorescent proteins has several shortcomings. Post-translational labeling methods using a genetically encodable tag and synthetic probes targeting to the tag can overcome these limitations. This review summarizes emerging tag–probe techniques for labeling specific membrane proteins and their applications, including endocytotic internalization, partitioning to specific membrane domains, interprotein interactions, and conformational changes
Development of nickel-metal hydride cell
National Space Development Agency of Japan (NASDA) has conducted the research and development (R&D) of battery cells for space use. A new R&D program about a Nickel-Metal Hydride (Ni-MH) cell for space use from this year, based on good results in evaluations of commercial Ni-MH cells in Tsukuba Space Center (TKSC), was started. The results of those commercial Ni-MH cell's evaluations and recent status about the development of Ni-MH cells for space use are described
Superconformal Sigma Models in Higher Than Two Dimensions
Rigidly superconformal sigma models in higher than two dimensions are
constructed. These models rely on the existence of conformal Killing spinors on
the dimensional worldvolume , and homothetic conformal Killing
vectors in the --dimensional target space. In the bosonic case, substituting
into the action a particular form of the target space metric admitting such
Killing vectors, we obtain an action with manifest worldvolume conformal
symmetry, which describes the coupling of scalars to a conformally flat
metric on the worldvolume. We also construct gauged sigma models with
worldvolume conformal supersymmetry. The models considered here are
generalizations of the singleton actions on , constructed
sometime ago by Nicolai and these authors.Comment: 16 pages, plain te
Association-Dissociation Dynamics of Transmembrane Helices as Detected by Single-Molecule Fluorescence Microscopy
Elevated levels of placental growth factor represent an adaptive host response in sepsis
Recently, we demonstrated that circulating levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are increased in sepsis (Yano, K., P.C. Liaw, J.M. Mullington, S.C. Shih, H. Okada, N. Bodyak, P.M. Kang, L. Toltl, B. Belikoff, J. Buras, et al. 2006. J. Exp. Med. 203:1447–1458). Moreover, enhanced VEGF/Flk-1 signaling was shown to contribute to sepsis morbidity and mortality. We tested the hypothesis that PlGF also contributes to sepsis outcome. In mouse models of endotoxemia and cecal ligation puncture, the genetic absence of PlGF or the systemic administration of neutralizing anti-PlGF antibodies resulted in higher mortality compared with wild-type or immunoglobulin G–injected controls, respectively. The increased mortality associated with genetic deficiency of PlGF was reversed by adenovirus (Ad)-mediated overexpression of PlGF. In the endotoxemia model, PlGF deficiency was associated with elevated circulating levels of VEGF, induction of VEGF expression in the liver, impaired cardiac function, and organ-specific accentuation of barrier dysfunction and inflammation. Mortality of endotoxemic PlGF-deficient mice was increased by Ad-mediated overexpression of VEGF and was blocked by expression of soluble Flt-1. Collectively, these data suggest that up-regulation of PlGF in sepsis is an adaptive host response that exerts its benefit, at least in part, by attenuating VEGF signaling
Goreisan Inhibits Upregulation of Aquaporin 4 and Formation of Cerebral Edema in the Rat Model of Juvenile Hypoxic-Ischemic Encephalopathy
Secondary cerebral edema regulation is of prognostic significance in hypoxic-ischemic encephalopathy (HIE), and aquaporin 4 (AQP4) plays an important role in the pathogenesis of cerebral edema. The traditional Japanese herbal medicine Goreisan relieves brain edema in adults; however, its effect and pharmacological mechanism in children are unknown. We investigated the effects of Goreisan on HIE-associated brain edema and AQP4 expression in a juvenile rat model, established by combined occlusion of middle cerebral and common carotid arteries. Magnetic resonance imaging showed that the lesion areas were significantly smaller in the Goreisan- (2 g/kg) treated group than in the nontreated (saline) group at 24 and 48 h postoperatively. AQP4 mRNA levels in the lesion and nonlesion sides were significantly suppressed in the Goreisan group compared with the nontreated group 36 h postoperatively. Western blotting revealed that levels of AQP4 protein were significantly decreased in the Goreisan group compared with the nontreated group in the lesion side 72 h postoperatively, but not at 12 or 36 h. After 14 days, the Goreisan group had a significantly better survival rate. These findings suggest that Goreisan suppresses brain edema in HIE and improves survival in juvenile rats, possibly via regulation of AQP4 expression and function
Ongoing EEG artifact correction using blind source separation
Objective: Analysis of the electroencephalogram (EEG) for epileptic spike and
seizure detection or brain-computer interfaces can be severely hampered by the
presence of artifacts. The aim of this study is to describe and evaluate a fast
automatic algorithm for ongoing correction of artifacts in continuous EEG
recordings, which can be applied offline and online. Methods: The automatic
algorithm for ongoing correction of artifacts is based on fast blind source
separation. It uses a sliding window technique with overlapping epochs and
features in the spatial, temporal and frequency domain to detect and correct
ocular, cardiac, muscle and powerline artifacts. Results: The approach was
validated in an independent evaluation study on publicly available continuous
EEG data with 2035 marked artifacts. Validation confirmed that 88% of the
artifacts could be removed successfully (ocular: 81%, cardiac: 84%, muscle:
98%, powerline: 100%). It outperformed state-of-the-art algorithms both in
terms of artifact reduction rates and computation time. Conclusions: Fast
ongoing artifact correction successfully removed a good proportion of
artifacts, while preserving most of the EEG signals. Significance: The
presented algorithm may be useful for ongoing correction of artifacts, e.g., in
online systems for epileptic spike and seizure detection or brain-computer
interfaces.Comment: 16 pages, 4 figures, 3 table
Use of the Hydrogen Breath Test to Determine the Influence of Antibiotic Prophylaxis on Intestinal Flora
Purpose: This experimental study was designed to use the hydrogen (H2) breath test to investigate changes in the intestinal flora of patients that were administered prophylactic antibiotics for 48 hours after surgery.
Methods: Altogether, 22 patients were divided into two groups and the antimicrobial prophylactics, cefazolin (3.0 g/day) or sulbactam/ampicillin (4.5 g/day), were administered on induction of anaesthesia for 48 hours after surgery. End expiratory breath samples were collected on the morning of the day of surgery and every morning for 1-6 days after surgery.
Results: H2 breath concentration significantly decreased in each group on day 1 (cefazolin: 1.20 ± 0.39 ppm vs. sulbactam/ampicillin: 1.17 ± 0.34 ppm). On day 2, the H2 concentration in the sulbactam/ampicillin group was significantly lower than the cefazolin group (cefazolin: 6.4 ± 2.2 ppm vs. sulbactam/ampicillin: 1.0 ± 0.4 ppm, p < 0.05). H2 concentration was still lower in the sulbactam/ampicillin group (1.3 ± 0.3 ppm vs. 3.3 ± 1.0 ppm, p = 0.10) on day 3. On days 4-6, H2 concentration was essentially the same for both groups.
Discussion: Colonic anaerobes are thought to be a reservoir of resistant organisms and prolonged antimicrobial treatment is a major cause for the development of resistance. Surgical prophylaxis is basically recommended for use within 24 hours after surgery. The breath H2 concentration in both groups significantly decreased 24 hours after administration. These results suggest that both antibiotics influence the activity of colonic anaerobes and the duration of surgical antibiotic prophylaxis should be as short as possible
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