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A prospective study was conducted to test the utility of the motor evoked potentials (MEPs) from the erector spinae muscles as a measure to estimate the motor level of thoracic compression myelopathies in 13 consecutive patients.To confirm whether this test is a useful addition to the neurological examination in non-invasively localizing the level responsible for the main functional change in mild to moderate thoracic myelopathy.Department of Orthopaedic Surgery, Kochi Medical School, Kochi, Japan.This electrophysiological study consisted of transcranial magnetic stimulation (TMS) of the brain and surface recording of MEPs from voluntarily contracted erector spinae muscles with the patient in the prone position. The recordings were obtained unilaterally from the same side as the lower-limb affected at 12 serial interspinous levels from T5-6 to L4-5. The results were compared to the MEP data from normal subjects and to neurological and MRI findings.Multisegmental MEP studies demonstrated a focal conduction block in one patient, a single site of conduction delay in seven, and normal conduction in five. The conduction block was characterized by an abrupt reduction in amplitude of the MEPs. Examination of the sites conduction delay showed that the latency difference between the two adjacent levels was longer than the corresponding normal upper limit by 1.00+/-0.40 ms (range, 0.62-1.61 ms). The site of conduction abnormalities approximated to the compressive lesion site shown by MRI. All five patients with false-negative MEP findings had the lesion site at or caudal to the T10-11 vertebral level.This method has the advantage of instantaneously testing multisegments of the thoracic spinal cord. The technique is of particular value in estimating the motor level of the lesions rostral to T10-11 vertebral level, which can not be achieved by clinical examinations or MEP recordings from the lower limb.

Synovial fluid in inflamed joint shows a drop in pH, which activates proton-gated ion channels in nociceptors. No studies have ever tried to develop and characterize acid-induced joint pain.Rats were injected intra-articularly with pH 4.0 acidic saline twice, 5 days apart. Pain-related behaviour tests including weight-bearing asymmetry, paw withdrawal threshold and knee compression threshold were conducted. To clarify the roles of proton-gated ion channels, rats were injected intra-articularly with selective antagonists for ASIC1a, ASIC3 and TRPV1 on day 5 (before the second injection) or on day 14. Underlying peripheral and central pain mechanisms were evaluated using joint histology, interleukin-1β concentrations in the synovium, single-fibre recording of the knee afferent and expression of phosphorylated cyclic adenosine monophosphate-responsive element-binding protein (p-CREB) in the spinal dorsal horn.Repeated injections of acidic saline induced weight-bearing asymmetry, decrease in paw withdrawal threshold and knee compression threshold bilaterally, which lasted until day 28. Early administration of ASIC3 antagonist reduced the bilateral and long-lasting hyperalgesia. Neither articular degeneration nor synovial inflammation was observed. C-fibre of the knee afferent was activated by acidic saline, which was attenuated by pre-injection of ASIC3 antagonist. p-CREB expression was transiently up-regulated bilaterally on day 6, but not on day 14.We developed and characterized a model of acid-induced long-lasting bilateral joint pain. Peripheral ASIC3 and spinal p-CREB played important roles for the development of hyperalgesia. This animal model gives insights into the mechanisms of joint pain, which is helpful in developing better pain treatments.

We attempt the optimum design of the ultra-deep hydrodesulfurization required in the future or for the hydrogenation of aromatics in diesel oil, as the conventional reaction model based on n-th order of desulfurization is no more accurate enough. A further buildup of reaction simulator for reactor design was attempted. Distribution Function Model is developed in the present study. In this model, the distribution of rate constants is expressed with a Γ function. It is clear that the predictions agreed well with the observed data, down to the ultra-deep desulfurization range. This model could also be applied for various kinds of oil fractions and wide desulfurization reaction conditions. The reactor sizes were estimated, compared with both the distribution function and n-th order reaction models, in order to obtain diesel oil of sulfur level required by European Auto-Oil II Program. The reactor size calculated by the Distribution Function Reaction Model is estimated as being smaller than that estimated by the conventional 1.7th order. It means that a more competitive design of the process will be provided by the new model and will allow more practical feasibility study and the plant design for ultra-deep desulfurization process.

Objectives : We studied waveform changes associated with a focal conduction block in compression myelopathies. Design and Methods : A total of 26 patients underwent serial intervertebral recording of spinal somatosensory evoked potentials (SSEPs) after epidural stimulation. The site of compression identified by abrupt reduction in size of the negative peak was designated as 0 level with the other levels numbered in order of distance assigning a minus sign caudally. Results : Considering the response recorded at −4 as baseline (100%), SSEPs showed a progressive increase rostrally, reaching an average of 154% in amplitude and 216% in area at −1 followed by an abrupt decline to 32% and 31% at 0. The incremental change of the negative peak was accompanied by a small reduction in area of the initial positive component to 90% at −1 considering the value at −4 as baseline (100%). Conclusions : The theory of solid angle approximation and the concept of phase cancellation best explain the apparently paradoxical enhancement of the negative peak which characterize typical waveform changes at the site of conduction block.

The cytocompatibility of new Ti alloys not containing Al and V such as Ti-15Zr-4Nb-4Ta-0.2Pd-0,05%N-0.2%O and Ti-15Sn-4Nb-2Ta-0.2Pd-0.2%O were investigated by comparing with those of pure Ti grade 2 andTi-6%Al-4%V ELI (extra low interstitial) alloys. The relative growth ratios of both L929 and MC3T3-E1 cells for the new Ti alloys were almost equal to 1 and were slightly higher than pure Ti grade 2 and Ti-6Al-4V alloys. Also, the influence of extracting conditions with E-MEM solution and ultrapure water on the relative growth ratio of cells were examined. Furthermore, the relationship between metallic concentration in the medium extracted with Ti, Al, V, Zr, Sn, Nb, Ta and Pd powders and the relative growth ratios of L929 cells were evaluated. The relative growth ratio for the medium extraction of Al, containing very little V ions (less than 0.02 ppm) tend to be too low as compared to that of V free Al extraction. However, extraction of Ti, Zr, Sn, Nb and Ta powders, and mixtures of powders such as Ti + Zr + Mb + Ta and Ti + Sn + Nb + Ta had evidently no effect on the relative growth ratio of L929 cells.

Infrared-absorption spectra of solid ${\mathrm{H}}_{2}$S have been measured at high pressures up to 50 GPa and room temperature. The symmetric stretching overtone vibration 2${\ensuremath{\nu}}_{1}$ shows a redshift in frequency with increasing pressure, and changes into two components at about 11 GPa for the II-IV phase transition. The pressure dependence of the observed 2${\ensuremath{\nu}}_{1}$, ${\ensuremath{\nu}}_{2}$+${\ensuremath{\nu}}_{3}$ (bending plus asymmetric-stretching combination bands), and ${\ensuremath{\nu}}_{2}$ vibrations shows strongly the existence of the phase transition from IV to V at about 30 GPa, which is consistent with a recent high-pressure x-ray study. The derived frequencies of fundamental ${\ensuremath{\nu}}_{1}$ and ${\ensuremath{\nu}}_{3}$ vibrations continue to decrease with pressure up to the IV\ensuremath{\rightarrow}V phase transition, and show small jumps at its point and moreover decrease slightly up to 45 GPa. The S-H- - -S hydrogen-bond system still exists up to at least 45 GPa; however, its bonding is very weak.

The subchondral bone of the distal femur is a source of pain caused by osteoarthritis (OA) or spontaneous osteonecrosis of the knee. However, nociceptive phenotype of dorsal root ganglia (DRG) neurons innervating the subchondral bone in rat knee joints has not been clarified.Retrograde labelling was used to identify afferents innervating the subchondral bone of the distal femur and the knee joint in rats. The nociceptive phenotype markers [calcitonin gene-related peptide (CGRP), tyrosine receptor kinase A (TrkA), neurofilament 200 (NF200) and isolectin B4 (IB4)], segmental distribution and the soma size of backlabelled DRG neurons were examined. Furthermore, we evaluated the differences in nociceptive phenotype between the subchondral bone and the knee joint afferents.The majority (60%) of the subchondral bone afferents were localized in L3 DRGs and fewer in L4 and L5, while the knee joint afferents were localized mainly in L3 and L4. The percentage of CGRP immunoreactive (IR), TrkA-IR, NF200-IR and IB4-binding neurons in the subchondral bone afferents were 50%, 65%, 35% and 0%, respectively. The percentage of CGRP-IR and TrkA-IR neurons in the subchondral bone afferents was significantly higher than that in the knee joint afferents, respectively (p 0.05).The majority of sensory DRG neurons innervating the subchondral bone of the distal femur were CGRP-IR and TrkA-IR. It is expected that therapeutic approaches targeting CGRP and TrkA could be effective in attenuating pain from the subchondral bone in knee joints.

The effect of Ti, V and Al ions on the relative growth rate of L929 cells and MC3T3-E1 cells was investigated by a cell culture method with metallic powders. These powders were sterilized under a U.V. lamp for 6 h, suspended in the medium and extracted for 48 h, 72 h and 96 h in the incubator. After filtering with a 0.2 microns filter, 3.0 x 10(4) L929 cells and 5 x 10(4) MC3T3-E1 cells were seeded in these filtrates of the medium with and without (control) the presence of the metallic powder. The number of cells was counted using a coulter counter from 1 to 7 days. The number of L929 cells after 4 days of incubation was almost similar for Ti and the control, whereas in the case of A1 and V extraction the number of cells was too low as compared to that of the control. The relative growth rate of L929 cells for Ti, A1 and V after 4 days of incubation was about 1, 0.2 and 0.02, respectively. A similar trend was also observed for MC3T3-E1 cells. The effect of the relative growth rate of L929 cells at different extraction times of 48 h, 72 h and 96 h was examined. It was found that the relative growth rate of L929 cells for Ti, A1 and V extraction was almost the same at all three extraction times. A number of 2.0-5.0 x 10(4) cells was seeded in the medium of A1 extraction. The effect of this initial number of cells on the relative growth rate of L929 cells was investigated. The relative growth rate of L929 cells decreased as the initial number of L929 cells increased. Moreover, dilutions from 1 to 10 times in the case of A1 and from 1 to 4000 times in the case of V were made. The relative growth rate became equal to 1 at 5 times dilution for A1 and at 4000 times dilution for V, for both L929 and MC3T3-E1 cells. From the measures of the concentration of the released A1 and V ions on the relative growth rate of L929 cells, it could be seen that there was a marked decrease in the concentrations of A1 and V ions from 0.3 ppm to 0.1 ppm.

It has been postulated that physical immobilization is an essential factor in developing chronic pain after trauma or surgery in an extremity. However, the mechanisms of sustained immobilization-induced chronic pain remain poorly understood. The present study, therefore, aimed to develop a rat model for chronic post-cast pain (CPCP) and to clarify the mechanism(s) underlying CPCP. To investigate the effects of cast immobilization on pain behaviours in rats, one hindlimb was immobilized for 2 weeks with a cast and remobilization was conducted for 10 weeks. Cast immobilization induced muscle atrophy and inflammatory changes in the immobilized hindlimb that began 2 h after cast removal and continued for 1 week. Spontaneous pain-related behaviours (licking and reduction in weight bearing) in the immobilized hindlimb were observed for 2 weeks, and widespread mechanical hyperalgesia in bilateral calves, hindpaws and tail all continued for 5-10 weeks after cast removal. A sciatic nerve block with lidocaine 24 h after cast removal transitorily abolished bilateral mechanical hyperalgesia in CPCP rats, suggesting that sensory inputs originating in the immobilized hindlimb contribute to the mechanism of both ipsilateral and contralateral hyperalgesia. Intraperitoneal injection of the free radical scavengers 4-hydroxy-2,2,6,6-tetramethylpiperydine-1-oxy1 or N-acetylcysteine 24 h after cast removal clearly inhibited mechanical hyperalgesia in bilateral calves and hindpaws in CPCP rats. These results suggest that cast immobilization induces ischaemia/reperfusion injury in the hindlimb and consequent production of oxygen free radicals, which may be involved in the mechanism of widespread hyperalgesia in CPCP rats.

Influence of the Gd spin on the Co hyperfine field has been studied by 59Co nuclear magnetic resonance (NMR) in (Y1−xGdx)2Co14B compounds. It is shown that the hyperfine coupling constants from the Gd spin for 8j1 and 8j2 sites are negative while those for 16k1 and 16k2 sites are positive. The dependence of the spin orientation temperature on the non-magnetic Y concentration in (Y1−xTbx)2Co14B is also investigated by magnetization and 59Co NMR measurements. A spin phase diagram for this compound is proposed.

Capillary endothelial cells (ECs) were cultured on gold electrodes in polydimethylsiloxane (PDMS)/glass microdevices. Our objective was to monitor the culture growth by electrical impedance spectroscopy (EIS) measurements, and to observe whether the formation of capillary-like structures in the cell layer produces a change in the impedance spectra. In our contribution, we present a novel micro-device, which enables long-term cell culture and the monitoring of the cell layer properties. We illustrate the usefulness of EIS measurements in observing several culture conditions (confluence, cell detachment, cell death, capillary formation) by providing impedance measurement curves, as well as cell layer pictures of the culture area.

The aim of study is the recognition on the voice-prints. This paper describes how raw vowels in signals consisting of voices and environmental noise are recognized using a neural network method for the binary two dimensional lattice array composed of 10/spl times/10=100 for the normalized DFT of voices.

The aim of this study is to measure adhesion strength of cultured cells to bioceramics such as alumina, and to adapt a mathematical model of defect growth kinetics to the cell adhesion phenomena. Fibroblasts from mouse (L-929) were cultured on alumina plates and fibronectin-coated alumina plates. The adhesion strength was measured by loading adhered cells with centrifugal force vertical to the material's surface. At the same time, we measured adhered areas and morphology of cells on the 2 types of surfaces by using an image analyzing method. The results show that the cells adhered more tightly to fibronectin coated alumina than to alumina. (50% of the cells were peeled off from the fibronectin-coated alumina under the load of 500 G, while 50% of the cells were peeled off from the alumina under the load of 100 G.) The image processed data show that the average of adhered areas of cells to fibronectin coated alumina was 3 times as large as to alumina 6 hours after seeding. The results show influence of fibronectin-receptor bonds on the cell's adhesion strength and the cell's adhesion phenomena. Considering the influence of fibronectin-receptor bonds, a mathematical model of defect growth kinetics was adapted to the cells adhesion phenomena, where we assumed that the rate of condensation of vacancies or the rate of rupture of fibronectin-receptor bonds at the tip of the crack was proportional to the radius of the crack.

A novel three-dimensional porous scaffold has been developed for bone tissue engineering by hybridizing synthetic poly(DL-lactic-co-glycolic acid) (PLGA), naturally derived collagen, and inorganic apatite. First, a porous PLGA sponge was prepared. Then, collagen microsponges were formed in the pores of the PLGA sponge. Finally, apatite particulates were deposited on the surfaces of the collagen microsponges in the pores of PLGA sponge. The PLGA-collagen sponge served as a template for apatite deposition, and the deposition was accomplished by alternate immersion of PLGA-collagen sponge in CaCl(2) and Na(2)HPO(4) aqueous solutions and centrifugation. The deposited particulates were small and scarce after one cycle of alternate immersion. Their number and size increased with the number of alternate immersion cycles. The surfaces of collagen microsponges were completely covered with apatite after three cycles of alternate immersion. The porosity of the hybrid sponge decreased gradually as the number of alternate immersion increased. Energy-dispersive spectroscopy analysis and X-ray diffraction spectra showed that the calcium-to-phosphorus molar ratio of the deposited particulates and the level of crystallinity increased with the number of alternate immersion cycles, and became almost the same as that of hydroxyapatite after four cycles of alternate immersion. The deposition process was controllable. Use of the PLGA sponge as a mechanical skeleton facilitated formation of the PLGA-collagen-apatite hybrid sponge into desired shapes and collagen microsponges facilitated the uniform deposition of apatite particulates throughout the sponge. The PLGA-collagen-apatite hybrid sponge would serve as a useful three-dimensional porous scaffold for bone tissue engineering.

We treated 31 patients aged 65 years or more with cervical spondylotic myelopathy by microsurgical decompression and fusion at a single most appropriate level, in spite of MRI evidence of compression at several levels. Spinal cord potentials evoked at operation localised the level responsible for the principal lesion at C3-4 in 18 patients, C4-5 in 11 and at C5-6 in two. Despite the frequent coexistence of other age-related conditions, impairing ability to walk, the average Nurick grade improved from 3.5 before operation to 2.2 at a mean follow-up of 48 months. There was also good recovery of finger dexterity and sensitivity. Operation at a single optimal level, as opposed to several, has the advantage of minimising complications, of particular importance in this age group.

The influence of gadolinium atoms on the 59 Co hyperfine field has been studied in compounds (Y 1− x Gd x ) 2 Co 14 B by spin echo experiment in zero field at 4.2 K. The resonance frequencies for 59 Co nuclei on the 16k 1 and 16k 2 sites are gradually reduced by the addition of Gd atoms. On the other hand, those for 59 Co on the 8j 1 and 8j 2 sites increase slightly.

We established a novel method to investigate the phagocytosis of ultra high molecular weight polyethylene using primary macrophage cells by an inverted cell culture method. Abundant wear debris derived from implant materials are generated in aseptic loosening and are deposited in periprosthetic tissues in which they are phagocytized by mono- and multi-nucleated macrophage like cells. Ultra-high-molecular-weight-polyethylene wear debris generated from different sources namely, from laboratory test wear machine, in vivo methods and from knee and hip simulator were mainly used in this investigation. The cytotoxicity index of the different UHMWPE particles obtained from various sources were compared with that of the PE beads and the control without particles by Alamar Blue and Neutral Red assays. The results showed that the cytotoxicity index was significantly lower for the wear debris from the in vivo experiments than that for other particles. SEM analysis were also done to understand the morphology of the wear debris and polyethylene beads and to confirm the phagocytosis process. The mean diameter of the wear debris obtained from the in vivo experiments as estimated from the imaging analysis of the SEM photographs was found to be the least. The inverted cell culture method may be regarded as one of the good methods to study the phagocytosis of UHMWPE by macrophage cells.

Recently we experienced a case of tracheal tube obstruction due to the upward displacement of carina during CD (Cotrel-Dubousset) instrumentation for idiopathic scoliosis. Therefore, we hypothesized that CD instrumentation may affect the position of the carina as a result of correction of chest deformity, and studied the displacement of carina before and after CD instrumentation on chest X-ray in 12 patients with scoliosis. The length between the bottom of the 6th cervical vertebral body and the carina was measured by using chest X-ray before and after the correction. In all patients studied, cephalad movement of the carina was observed, and it was more than 1.00 cm in 5 patients. The maximal movement of the carina was 1.59 cm. The tracheal length after the correction was significantly shorter than before (P0.01). These results suggest that the carina may be displaced upwards due to the correction by the CD instrumentation, and that such induced displacement may affect the tracheal tube position and obstruct the tube during the operation.

Single nerve fiber action potential (single-NAP) was computer simulated using solid angle approximation theory. The simulated spinal cord evoked potential (Simulated-SCEP) was then produced by summing the simulated single-NAPs according to the data of the fiber diameter spectrum of the human spino-cerebellar tract. To model the conduction block phenomenon in the spinal cord, it was assumed that each fiber impulse which reached the conduction block point could not go through the point and gradually became smaller. When the largest 10% of the constituent fibers had become blocked, there was augmentation of the negative peak at just before the conduction block point and at every point after the block. As the percentage of the blocked fibers increased, the amplitude of the simulated-SCEP decreased at every point except at just before the block. When 50% or more of the largest fibers were blocked, then augmentation of the negative peak still remained at just before the conduction block. However at the points just after the conduction block there was a monophasic positive waveform which is known as the killed-end potential. Phase cancellation normally dictates the wave forms of compound action potential. However, the killed-end potential and the augmentation of the amplitude associated with the conduction block can be explained by the loss of the phase cancellation.

Bi-Sr-Ca-Cu-0 thin films were prepared by using a rf magnetron sputtering. The films were grown on MgO substrates at 300°C cyclically by sputtering through an off-centered shutter hole while rotating the substrate table. Then the films were annealed at 860°C for 10 hours in the mixture of O2/N2=1/10.