Reduction of bone cancer pain by CB1 activation and TRPV1 inhibition

ArticleJOURNAL OF ANESTHESIA. 24(2):328-332 (2010)journal articl

UDFS in shoulder surgeries

The purpose of this study was to clarify the difference in onset timing and incidence of undiagnosed finger symptom (UDFS) between various shoulder surgical procedures. In this study, UDFS symptoms included the following four symptoms in the fingers ; edema, limited range-of-motion, skin color changes, and abnormal sensations. UDFS cases were defined as those presenting with at least one UDFS. In result, the incidence rate of UDFS cases was 7.1% overall (58 / 816 shoulders), 7.4% (32 / 432) in arthroscopic rotator cuff repair (ARCR), 9.0% (11 / 122) in open rotator cuff repair (ORCR), 1.4% (2 / 145) in arthroscopic subacromial decompression (ASD), 13.2% (5 / 38) in open reduction and internal fixation (ORIF), 11.1% (3 / 27) in humeral head replacement, 4.8% (1 / 21) in anatomical total shoulder arthroplasty, and 12.9% (4 / 31) in reverse total shoulder arthroplasty cases. The Rate was significantly higher with ARCR compared to ASD (p < .01). About onset timing in weeks postoperatively, the ORIF group had a statistically earlier symptom onset than the Rotator cuff repair (ARCR + ORCR) group (2.4 weeks vs. 6.0 weeks, p < .01). When classifying the onset timing into before and after the removal of the abduction pillow, the ORIF group showed a statistically higher rate of onset before brace removal than the Rotator cuff repair groups (p < .01). Differences in UDFS among shoulder surgeries were demonstrated in this study

Bone cancer induces a unique central sensitization through synaptic changes in a wide area of the spinal cord

<p>Abstract</p> <p>Background</p> <p>Chronic bone cancer pain is thought to be partly due to central sensitization. Although murine models of bone cancer pain revealed significant neurochemical changes in the spinal cord, it is not known whether this produces functional alterations in spinal sensory synaptic transmission. In this study, we examined excitatory synaptic responses evoked in substantia gelatinosa (SG, lamina II) neurons in spinal cord slices of adult mice bearing bone cancer, using whole-cell voltage-clamp recording techniques.</p> <p>Results</p> <p>Mice at 14 to 21 days after sarcoma implantation into the femur exhibited hyperalgesia to mechanical stimuli applied to the skin of the ipsilateral hind paw, as well as showing spontaneous and movement evoked pain-related behaviors. SG neurons exhibited spontaneous excitatory postsynaptic currents (EPSCs). The amplitudes of spontaneous EPSCs were significantly larger in cancer-bearing than control mice without any changes in passive membrane properties of SG neurons. In the presence of TTX, the amplitude of miniature EPSCs in SG neurons was increased in cancer-bearing mice and this was observed for cells sampled across a wide range of lumbar segmental levels. Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor- and <it>N</it>-methyl-<it>D</it>-aspartate (NMDA) receptor-mediated EPSCs evoked by focal stimulation were also enhanced in cancer-bearing mice. Dorsal root stimulation elicited mono- and/or polysynaptic EPSCs that were caused by the activation of Aδ and/or C afferent fibers in SG neurons from both groups of animals. The number of cells receiving monosynaptic inputs from Aδ and C fibers was not different between the two groups. However, the amplitude of the monosynaptic C fiber-evoked EPSCs and the number of SG neurons receiving polysynaptic inputs from Aδ and C fibers were increased in cancer-bearing mice.</p> <p>Conclusions</p> <p>These results show that spinal synaptic transmission mediated through Aδ and C fibers is enhanced in the SG across a wide area of lumbar levels following sarcoma implantation in the femur. This widespread spinal sensitization may be one of the underlying mechanisms for the development of chronic bone cancer pain.</p

Optical manipulation of a single clay nanosheet hybridized with a porphyrin derivative

The effect of hybridization of a clay fluorohectorite (FHT) nanosheet with a π-conjugated organic compound, α,β,γ,δ-tetrakis(1-methylpyridinium-4-yl)porphyrin p-toluene-sulfonate (TMPyP), on its optical manipulation is investigated. Although the hybridized FHT is optically trapped essentially in the same manner as that of neat FHT, the hybridization with TMPyP allows for manipulation of FHT with lower laser intensity or a shorter period, or both. This is ascribed to the larger refractive index and polarizability of TMPyP compared with neat FHT

OPTICAL TRAPPING AND ORIENTATION MANIPULATION OF 2D INORGANIC MATERIALS USING A LINEARLY POLARIZED LASER BEAM

Because inorganic nanosheets, such as clay minerals, are anisotropic, the manipulation of nanosheet orientation is an important challenge in order to realize future functional materials. In the present study, a novel methodology for nanosheet manipulation using laser radiation pressure is proposed. When a linearly polarized laser beam was used to irradiate a niobate (Nb6O 4-17) nanosheet colloid, the nanosheet was trapped at the focal point so that the in-plane direction of the nanosheet was oriented parallel to the propagation direction of the incident laser beam so as to minimize the scattering force. In addition, the trapped nanosheet was aligned along the polarization direction of the linearly polarized laser beam

Radiation-Pressure-Induced Hierarchical Structure of Liquid-Crystalline Inorganic Nanosheets

Although hierarchical assemblies of colloidal particles add novel structure-based functions to systems, few local and on-demand colloidal structures have been developed. We have combined the colloidal liquid crystallinity of two-dimensional inorganic particles and laser radiation pressure to obtain a large hierarchical and local structure in a colloidal system. The scattering force of the laser beam converted the parallel nanosheet alignment to the direction of the incident laser beam. At the focal point, the nanosheet orientation depends on the electric field of the polarized laser beam. In contrast, a giant tree-ring-like nanosheet texture of more than 100 μm, and which is independent of the polarization direction, was organized at the periphery of the focal point. This organization resulted from a cooperative effect between the liquid-crystalline nanosheets, which indicates an effectiveness of optical manipulation to construct hierarchical colloidal structures with the aid of interparticle interactions

Microscope Observation of Morphology of Colloidally Dispersed Niobate Nanosheets Combined with Optical Trapping

Although inorganic nanosheets prepared by exfoliation (delamination) of layered crystals have attracted great attention as 2D nanoparticles, in situ real space observations of exfoliated nanosheets in the colloidally dispersed state have not been conducted. In the present study, colloidally dispersed inorganic nanosheets prepared by exfoliation of layered niobate are directly observed with bright-field optical microscopy, which detects large nanosheets with lateral length larger than several micrometers. The observed nanosheets are not strictly flat but rounded, undulated, or folded in many cases. Optical trapping of nanosheets by laser radiation pressure has clarified their uneven cross-sectional shapes. Their morphology is retained under the relation between Brownian motion and optical trapping

Birational cobordism invariance of uniruled symplectic manifolds

A symplectic manifold $(M,\omega)$ is called {\em (symplectically) uniruled} if there is a nonzero genus zero GW invariant involving a point constraint. We prove that symplectic uniruledness is invariant under symplectic blow-up and blow-down. This theorem follows from a general Relative/Absolute correspondence for a symplectic manifold together with a symplectic submanifold. A direct consequence is that symplectic uniruledness is a symplectic birational invariant. Here we use Guillemin and Sternberg's notion of cobordism as the symplectic analogue of the birational equivalence.Comment: To appear in Invent. Mat

Bile Acid Inhibition of N-type Calcium Channel Currents from Sympathetic Ganglion Neurons

Under some pathological conditions as bile flow obstruction or liver diseases with the enterohepatic circulation being disrupted, regurgitation of bile acids into the systemic circulation occurs and the plasma level of bile acids increases. Bile acids in circulation may affect the nervous system. We examined this possibility by studying the effects of bile acids on gating of neuronal (N)-type Ca2+ channel that is essential for neurotransmitter release at synapses of the peripheral and central nervous system. N-type Ca2+ channel currents were recorded from bullfrog sympathetic neuron under a cell-attached mode using 100 mM Ba2+ as a charge carrier. Cholic acid (CA, 10-6 M) that is relatively hydrophilic thus less cytotoxic was included in the pipette solution. CA suppressed the open probability of N-type Ca2+ channel, which appeared to be due to an increase in null (no activity) sweeps. For example, the proportion of null sweep in the presence of CA was ~40% at +40 mV as compared with ~8% in the control recorded without CA. Other single channel properties including slope conductance, single channel current amplitude, open and shut times were not significantly affected by CA being present. The results suggest that CA could modulate N-type Ca2+ channel gating at a concentration as low as 10-6 M. Bile acids have been shown to activate nonselective cation conductance and depolarize the cell membrane. Under pathological conditions with increased circulating bile acids, CA suppression of N-type Ca2+ channel function may be beneficial against overexcitation of the synapses