Background and Objective
We developed a quantitative method to measure movement representations of a phantom upper limb using a bimanual circle‐line coordination task (BCT). We investigated whether ...short‐term neurorehabilitation with a virtual reality (VR) system would restore voluntary movement representations and alleviate phantom limb pain (PLP).
Methods
Eight PLP patients were enrolled. In the BCT, they repeatedly drew vertical lines using the intact hand and intended to draw circles using the phantom limb. Drawing circles mentally using the phantom limb led to the emergence of an oval transfiguration of the vertical lines (‘bimanual‐coupling’ effect). We quantitatively measured the degree of this bimanual‐coupling effect as movement representations of the phantom limb before and immediately after short‐term VR neurorehabilitation. This was achieved using an 11‐point numerical rating scale (NRS) for PLP intensity and the Short‐Form McGill Pain Questionnaire (SF‐MPQ). During VR neurorehabilitation, patients wore a head‐mounted display that showed a mirror‐reversed computer graphic image of an intact arm (the virtual phantom limb). By intending to move both limbs simultaneously and similarly, the patients perceived voluntary execution of movement in their phantom limb.
Results
Short‐term VR neurorehabilitation promptly restored voluntary movement representations in the BCT and alleviated PLP (NRS: p = 0.015; 39.1 ± 28.4% relief, SF‐MPQ: p = 0.015; 61.5 ± 48.5% relief). Restoration of phantom limb movement representations and reduced PLP intensity were linearly correlated (p < 0.05).
Conclusions
VR rehabilitation may encourage patient's motivation and multimodal sensorimotor re‐integration of a phantom limb and subsequently have a potent analgesic effect.
Significance
There was no objective evidence that restoring movement representation by neurorehabilitation with virtual reality alleviated phantom limb pain. This study revealed quantitatively that restoring movement representation with virtual reality rehabilitation using a bimanual coordination task correlated with alleviation of phantom limb pain.
Summary Background Surgical site infection (SSI) after colorectal surgery is the leading cause of postoperative morbidity. Opioids induce immunosuppression through activation of μ-opioid receptors ...expressed on leucocytes, and through opioid withdrawal. A high dose of opioid administered as remifentanil during surgery may induce immunosuppression, leading to the development of SSI. Aim The purpose of this study was to investigate the influence of remifentanil on the development of SSI. Methods Adult patients who underwent elective colorectal surgery from January 2009 to December 2012 ( N = 286) were prospectively investigated according to the guidelines of the US Centers for Disease Control and Prevention. After exclusion of 51 patients, propensity matching was performed in 235 patients. To reduce the influence of selection on SSIs, propensity score pairwise matching was performed for patients maintained with remifentanil and for patients maintained with fentanyl. Findings The number of patients who developed SSI was higher after remifentanil-based anaesthesia compared with fentanyl-based anaesthesia 11.6% (17/146) vs 3.4% (3/89), remifentanil vs fentanyl, P = 0.03 before propensity matching. Propensity matching yielded 61 pairs of patients anaesthetized with remifentanil or fentanyl, and corrected several biases in the preoperative patient characteristics. After propensity matching, the number of patients who developed SSI was still higher after remifentanil-based anaesthesia than after fentanyl-based anaesthesia 16.4% (10/61) vs 3.3% (2/61), remifentanil vs fentanyl, P = 0.029. Conclusion Remifentanil-based anaesthesia increased the incidence of SSI. A possible reason may be opioid-induced immunosuppression or opioid withdrawal-induced immunosuppression.
We investigated the relationship between pain and hesitation during movement initiation among 11 adult female patients who had undergone surgery for a distal radius fracture. Data on the patients’ ...pain at rest, pain during movement and score on the Pain Catastrophizing Scale were analyzed. Movement characteristics were assessed by the administration of a finger tapping (FT) task using the thumb and index finger, with the movement repeated 10 times, recorded and analyzed to determine the patient's hesitation when opening or closing her thumb/forefinger during the task. Hesitation of movement initiation was significantly correlated with subjective factors such as pain at rest, pain during movement, and rumination. Pain was not significantly correlated with the physical range of motion. Our findings suggest that hesitation during movement initiation for the FT task may be a type of behavior that is affected by subjective pain. Movement hesitation is a novel clinical sign indicating the possible progression of acute pain into chronic pain. The kinematic evaluation described herein is a convenient clinical measurement that captures a subjective factor.
Nous avons cherché la relation entre la douleur et l’hésitation de l’initiation du mouvement parmi des patientes ayant subi une opération pour une fracture distale du radius. Dix patientes adultes ont subi une opération pour une fracture distale du radius. Les données concernant les patientes au repos, pendant une douleur due à un mouvement ainsi que les chiffres de l’échelle de la dramatisation face à la douleur ont été analysés. Les caractéristiques de mouvement ont été évaluées par l’administration d’une tape sur le doigt (TD), tâche effectuée en utilisant le pouce et l’index, avec un mouvement répété 10 fois, enregistré et analysé pour déterminer l’hésitation de la patiente à ouvrir ou fermer son pouce/index pendant la tâche. L’hésitation de l’initiation du mouvement a montré une corrélation significative avec les facteurs subjectifs de douleur au repos, douleur pendant un mouvement, et rumination; cependant la douleur n’a montré aucune corrélation significative avec le facteur physique de l’amplitude du mouvement. Notre étude suggère que l’hésitation de l’initiative du mouvement dans la tâche de TD peut être un type de comportement qui est affecté par une douleur subjective. L’hésitation de mouvement est un signe clinique original indiquant l’évolution possible d’une douleur en douleur chronique. L’évaluation cinématique décrite ci-dessus est une mesure clinique commode qui inclut un facteur subjectif.
The major aim of the present study was to investigate whether painful stimuli have a differential effect on the Readiness Potential (RP) in terms of the early and late components. We hypothesized ...that painful stimuli would modulate the cortical movement preparatory activity and the components to a different extent when compared to non-painful stimuli.
The readiness potential (RP), which is a slow negative electrical brain potential that occurs before voluntary movement, can be interpreted as a measure of intrinsic brain activity originating from self-regulating mechanisms. Early and late components of the RP may indicate clinical-neurophysiological features such as motivation, preparation, intention, and initiation of voluntary movements. 15 healty volunteers were enrolled in this study. We conducted electrical stimulation trials in two randomized blocks termed as “no-pain condition” and “pain condition“. Our results demonstrated that painful stimuli were preceded by an enhanced RP at the Cz channel (p<0.05). The mean amplitude of the RP at the early phase was significantly higher for the painful stimuli when compared to the non-painful stimuli (p<0.05). Our results indicate that electrical painful stimuli, which can be considered as an unpleasant and stressful condition, modulate the motor preparation at sensory motor regions to a different extent when compared to non-painful electrical stimuli. Since early component of the RP represents cortical activation due to anticipation of the stimuli and the allocation of attentional resources, our results suggest that painful stimuli may affect the motor preparation processes and the prediction of the movement at the cortical level.
The number of foreign protein molecules expressed on the cell surface of the budding yeast Saccharomyces cerevisiae by cell surface engineering was quantitatively evaluated using enhanced green ...fluorescent protein (EGFP). The emission from EGFP on the cell surface was affected by changes in pH. The amount of EGFP on the cell surface, displayed as alpha-agglutinin-fusion protein under control of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter, was determined at the optimum pH of 7.0. The fluorometric analysis and the image analysis by confocal laser scanning microscopy (CLSM) showed a similar number of molecules displayed on the cell surface, demonstrating that 10(4)-10(5) molecules of alpha-agglutinin-fused molecules per cell were expressed. Furthermore, the amount of fluorescent protein expressed on cells harboring a multicopy plasmid was three to four times higher than that on cells harboring the gene integrated into the genome.
Purpose: In the thermal grill illusion, participants experience a feeling similar to burning pain. The illusion is induced by simultaneously touching warm and cool stimuli in alternating positions. ...In post-stroke pain, central sensitization is caused by a variety of factors, including damage to the spinothalamic tract and shoulder pain. Because the thermal grill illusion depends on central mechanisms, it has recently been suggested that it may be a useful indicator of central sensitization. Therefore, we hypothesized that post-stroke patients who are more likely to experience central sensitization may also be more likely to experience a thermal grill sensation of pain and discomfort than the likelihood among those who are less likely to experience central sensitization. However, the effects of the thermal grill illusion in post-stroke patients have not yet been reported. In this pilot study, we conducted the thermal grill illusion procedure in post-stroke patients and analyzed the relationship between clinical somatosensory functions and thermal grill sensations. We also conducted brain imaging analysis to identify brain lesion areas that were associated with thermal grill sensations. Patients and Methods: Twenty patients (65.7 + or - 11.9 years old) with post-stroke patients participated in this study. The thermal grill illusion procedure was performed as follows: patients simultaneously touched eight water-filled copper bars, with the water temperature adjusted to provide alternate warm (40degreesC) and cold (20degreesC) stimuli. Results: Thermal grill sensation of pain and discomfort tended to be associated with the wind-up phenomenon in bedside quantitative sensory testing and thermal grill sensation of discomfort was also related to damage to the thalamic lateral nucleus. Conclusion: These findings suggest that the thermal grill illusion might measure central sensitization, and that secondary brain hyperactivity might lead to increased thermal grill sensations. Keywords: thermal grill illusion, post stroke pain, central sensitization, thalamus, insula
We have engineered the cell surface of the yeast Saccharomyces cerevisiae by anchoring active glucoamylase protein on the cell wall, and we have endowed the yeast cells with the ability to utilize ...starch directly as the sole carbon source. The gene encoding Rhizopus oryzae glucoamylase with its secretion signal peptide was fused with the gene encoding the C-terminal half (320 amino acid residues from the C terminus) of yeast alpha-agglutinin, a protein involved in mating and covalently anchored to the cell wall. The constructed plasmid containing this fusion gene was introduced into S. cerevisiae and expressed under the control of the glyceraldehyde-3-phosphate dehydrogenase promoter from S. cerevisiae. The glucoamylase activity was not detected in the culture medium, but it was detected in the cell pellet fraction. The glucoamylase protein transferred to the soluble fraction from the cell wall fraction after glucanase treatment but not after sodium dodecyl sulfate treatment, indicating the covalent binding of the fusion protein to the cell wall. Display of the fused protein was further confirmed by immunofluorescence microscopy and immunoelectron microscopy. The transformant cells could surely grow on starch as the sole carbon source. These results showed that the glucoamylase was anchored on the cell wall and displayed as its active form. This is the first example of an application of cell surface engineering to utilize and improve the metabolic ability of cells
AtHKT1 is a sodium (Na(+)) transporter that functions in mediating tolerance to salt stress. To investigate the membrane targeting of AtHKT1 and its expression at the translational level, antibodies ...were generated against peptides corresponding to the first pore of AtHKT1. Immunoelectron microscopy studies using anti-AtHKT1 antibodies demonstrate that AtHKT1 is targeted to the plasma membrane in xylem parenchyma cells in leaves. AtHKT1 expression in xylem parenchyma cells was also confirmed by AtHKT1 promoter-GUS reporter gene analyses. Interestingly, AtHKT1 disruption alleles caused large increases in the Na(+) content of the xylem sap and conversely reduced the Na(+) content of the phloem sap. The athkt1 mutant alleles had a smaller and inverse influence on the potassium (K(+)) content compared with the Na(+) content of the xylem, suggesting that K(+) transport may be indirectly affected. The expression of AtHKT1 was modulated not only by the concentrations of Na(+) and K(+) but also by the osmolality of non-ionic compounds. These findings show that AtHKT1 selectively unloads sodium directly from xylem vessels to xylem parenchyma cells. AtHKT1 mediates osmolality balance between xylem vessels and xylem parenchyma cells under saline conditions. Thus AtHKT1 reduces the sodium content in xylem vessels and leaves, thereby playing a central role in protecting plant leaves from salinity stress.
There is a possibility that hydrogen absorbing alloys will generate unexpected stress in an alloy bed and deform or destroy the vessel because the alloys expand when they absorb hydrogen. The amount ...of stress generated on the vessel surface by alloy swelling was measured with the object of elongating the life time of the reaction vessel in heat utilization systems that use hydrogen absorbing alloys. As a result, it was found that 1) localized stress is generated at the bottom of the vessel due to hydrogen ab-/desorption cycles with an alloy packing fraction of 50 vol
%, and this stress not only increases with each cycle, but also continues to increase even after plastic deformation of the vessel, 2) stress accumulation depends on the amount of hydrogen ab-/desorption and on the initial packing fraction, and 3) the mechanism for stress accumulation can be estimated as a two-step process in which agglomeration between the hydride particles occurs when the packing fraction of hydride is higher than 61 vol
% in the initial cycles (Step 1), and then fine powder generated by pulverization during the cycles falls in gaps at the bottom of the vessel and causes the hydride packing fraction at the bottom of the vessel to gradually increase (Step 2).
Individuals with chronic low back pain (CLBP) experience changes in gait control due to pain and/or fear. Although CLBP patients' gait has been performed in laboratory environments, changes in gait ...control as an adaptation to unstructured daily living environments may be more pronounced than the corresponding changes in laboratory environments. We investigated the impacts of the environment and pathology on the trunk variability and stability of gait in CLBP patients.
CLBP patients (n=20) and healthy controls with no low-back pain history (n=20) were tasked with walking in a laboratory or daily-living environment while wearing an accelerometer on the low back. We calculated the stride-to-stride standard deviation and multiscale sample entropy as indices of "gait variability" and the maximum Lyapunov exponent as an index of "gait stability" in both the anterior-posterior and medial-lateral directions. The participants were assessed on the numerical rating scale for pain intensity, the Tampa Scale for Kinesiophobia, and the Roland-Morris Disability Questionnaire for quality of life (QOL).
In a repeated-measures ANOVA, the standard deviation was affected by environment in the anterior-posterior direction and by group and environment in the medial-lateral direction. Multiscale sample entropy showed no effect in the anterior-posterior direction and showed both effects in the medial-lateral direction. Maximum Lyapunov exponents showed both effects in the anterior-posterior direction, but none in the medial-lateral direction. These changes of trunk motor control by CLBP patients were found to be related to pain intensity, fear of movement, and/or QOL in the daily-living environment but not in the laboratory environment.
These results revealed that CLBP patients exhibit changes in trunk variability and stability of gait depending on the environment, and they demonstrated that these changes are related to pain, fear, and QOL. We propose useful accelerometer-based assessments of qualitative gait in CLBP patients' daily lives, as it would provide information not available in a general practice setting.
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