163 research outputs found
Role of satellite cell-derived l-serine in the dorsal root ganglion in paclitaxel-induced painful peripheral neuropathy
Paclitaxel is one of the most commonly used antineoplastic drugs for the treatment of solid tumors. Unfortunately, its use is often associated with dose-limiting painful peripheral neuropathy and subsequent neuropathic pain that is resistant to standard analgesics. However, there are few clinically available drugs or drug classes for the treatment of paclitaxel-induced neuropathy due to a lack of information regarding the mechanisms responsible for it. In this study, we examined the involvement of L-serine in paclitaxel-induced hyperalgesia/allodynia and decrease in sensory nerve conduction velocity (SNCV). We used a preclinical rat model of paclitaxel-induced painful peripheral neuropathy. Response to von Frey filaments, SNCV, 3-phosphoglycerate dehydrogenase (3PGDH) expression, and L-serine concentration were examined. Effects of L-serine administration were also investigated. Paclitaxel treatment induced mechanical allodynia/hyperalgesia and reduction of SNCV. Paclitaxel also decreased the L-serine concentration in the dorsal root ganglion (DRG) but not in the sciatic nerve or spinal cord. In addition, paclitaxel decreased expression of 3PGDH, a biosynthetic enzyme of L-serine, in the DRG. Immunohistochemistry showed that 3PGDH was localized in satellite cells but not in neurons in the DRG. Intraperitoneal administration of L-serine improved both paclitaxel-induced mechanical allodynia/hyperalgesia and the reduction of SNCV. These results suggest that satellite cell-derived L-serine in the DRG plays an important role in paclitaxel-induced painful peripheral neuropathy. These findings may lead to novel strategies for the treatment of paclitaxel-induced painful peripheral neuropathy.ArticleNEUROSCIENCE. 174(0):190-199 (2011)journal articl
Spin-orbit effects in a graphene bipolar pn junction
A graphene junction is studied theoretically in the presence of both
intrinsic and Rashba spin-orbit couplings. We show that a crossover from
perfect reflection to perfect transmission is achieved at normal incidence by
tuning the perpendicular electric field. By further studying angular dependent
transmission, we demonstrate that perfect reflection at normal incidence can be
clearly distinguished from trivial band gap effects. We also investigate how
spin-orbit effects modify the conductance and the Fano factor associated with a
potential step in both and cases.Comment: 6 pages, 5 figures, conductance and Fano factor plots adde
Bulk electronic state of superconducting topological insulator
We study electronic properties of a superconducting topological insulator
whose parent material is a topological insulator. We calculate the temperature
dependence of the specific heat and spin susceptibility for four promising
superconducting pairings proposed by L. Fu and E. Berg (Phys. Rev. Lett. 105,
097001). Since the line shapes of temperature dependence of specific heat are
almost identical among three of the four pairings, it is difficult to identify
them simply from the specific heat. On the other hand, we obtain wide varieties
of the temperature dependence of spin susceptibility for each pairing
reflecting the spin structure of Cooper pair. We propose that the pairing
symmetry of superconducting topological insulator can be determined from
measurement of Knight shift by changing the direction of applied magnetic
field.Comment: 12 pages, 15 figures. Accepted for publication in J. Phys. Soc. Jp
Significance of Off-Center Rattling for Emerging Low-lying THz Modes in type-I Clathrates
We show that the distinct differences of low-lying THz-frequency dynamics
between type-I clathrates with on-center and off-center guest ions naturally
follow from a theoretical model taking into account essential features of the
dynamics of rattling guest ions. Our model analysis demonstrates the drastic
change from the conventional dynamics shown by on-center systems to the
peculiar dynamics of off-center systems in a unified manner. We claim that
glass-like plateau thermal conductivities observed for off-center systems stem
from the flattening of acoustic phonon dispersion in the regime |k|<|G|/4. The
mechanism is applicable to other systems such as glasses or relaxers
Suppression of bone marrow-derived microglia in the amygdala improves anxiety-like behavior induced by chronic partial sciatic nerve ligation in mice
大脳辺縁系の一部である扁桃体は,不快情動の形成において重要な役割を担っている.我々は,神経障害性疼痛の慢性期に扁桃体中心核に集積する骨時由来ミクログリアが IL-1βを分泌して神経細胞に作用することで,慢性疼痛における不快情動の形成に関与することを明らかにした
Edge Current due to Majorana Fermions in Superfluid He A- and B-Phases
We propose a method utilizing edge current to observe Majorana fermions in
the surface Andreev bound state for the superfluid He A- and B-phases. The
proposal is based on self-consistent analytic solutions of quasi-classical
Green's function with an edge. The local density of states and edge mass
current in the A-phase or edge spin current in the B-phase can be obtained from
these solutions. The edge current carried by the Majorana fermions is partially
cancelled by quasiparticles (QPs) in the continuum state outside the superfluid
gap. QPs contributing to the edge current in the continuum state are
distributed in energy even away from the superfluid gap. The effect of Majorana
fermions emerges in the depletion of the edge current by temperature within a
low-temperature range. The observations that the reduction in the mass current
is changed by -power in the A-phase and the reduction in the spin current
is changed by -power in the B-phase establish the existence of Majorana
fermions. We also point out another possibility for observing Majorana fermions
by controlling surface roughness.Comment: 13 pages, 4 figures, published versio
Flat edge modes of graphene and of Z2 topological insulator
A graphene nano-ribbon in the zigzag edge geometry exhibits a specific type of gapless edge modes with a partly flat band dispersion. We argue that the appearance of such edge modes are naturally understood by regarding graphene as the gapless limit of a Z2 topological insulator. To illustrate this idea, we consider both Kane-Mele (graphene-based) and Bernevig-Hughes-Zhang models: the latter is proposed for HgTe/CdTe 2D quantum well. Much focus is on the role of valley degrees of freedom, especially, on how they are projected onto and determine the 1D edge spectrum in different edge geometries
Hot Start PCR with heat-activatable primers: a novel approach for improved PCR performance
The polymerase chain reaction (PCR) is widely used for applications which require a high level of specificity and reliability, such as genetic testing, clinical diagnostics, blood screening, forensics and biodefense. Great improvements to PCR performance have been achieved by the use of Hot Start activation strategies that aim to prevent DNA polymerase extension until more stringent, higher temperatures are reached. Herein we present a novel Hot Start activation approach in PCR where primers contain one or two thermolabile, 4-oxo-1-pentyl (OXP) phosphotriester (PTE) modification groups at 3′-terminal and 3′-penultimate internucleotide linkages. Studies demonstrated that the presence of one or more OXP PTE modifications impaired DNA polymerase primer extension at the lower temperatures that exist prior to PCR amplification. Furthermore, incubation of the OXP-modified primers at elevated temperatures was found to produce the corresponding unmodified phosphodiester (PDE) primer, which was then a suitable DNA polymerase substrate. The OXP-modified primers were tested in conventional PCR with endpoint detection, in one-step reverse transcription (RT)–PCR and in real-time PCR with SYBR Green I dye and Taqman® probe detection. When OXP-modified primers were used as substitutes for unmodified PDE primers in PCR, significant improvement was observed in the specificity and efficiency of nucleic acid target amplification
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