Impacts of workplace verbal aggression classified via text mining on workers' mental health

BACKGROUND

Exposure to workplace aggression adversely affects workers' health; however, little is known regarding the impact of specific types of verbal content.

AIMS

We aimed to examine the relationship between exposure to several types of aggressive words at work and the victim's depressive symptoms and sleep disturbance using text mining.

METHODS

We conducted a longitudinal survey with 800 workers in wholesale and retail companies; of which, 500 responded to the follow-up survey. The Centre for Epidemiologic Studies-Depression Scale and Pittsburgh Sleep Quality Index were filled out by the participants, and their responses were analysed by logistic regression to evaluate the risk of depression or sleep problems. We collected exact aggressive words encountered at work over the past year as a dependent variable and classified it into four types using text mining, such as words criticizing one's performance.

RESULTS

The follow-up rate was 63%. Exposure to words threatening one's life showed a significant relationship with the risk of depression (odds ratio [OR] = 13.94, 95% confidence interval [CI] = 1.76-110.56). The exposure to words criticizing one's job performance is significantly related to the risk of sleep disturbance (OR = 5.56, 95% CI = 2.08-14.88).

CONCLUSIONS

These findings suggest that different contents of verbal aggression can have different impacts on workers' health. This indicates that not only overtly threatening and abusive language but also words related to one's performance can be a risk factor for workers, depending on how they are delivered. To mitigate the adverse effects, promoting effective communication and cultivating psychological detachment from work may be beneficial.

Transsynaptic activation of human lumbar spinal motoneurons by transvertebral magnetic stimulation

Noninvasive spinal stimulation has been increasingly used in research on motor control and neurorehabilitation. Despite advances in percutaneous electrical stimulation techniques, magnetic stimulation is not as commonly used as electrical stimulation. Therefore, it is still under discussion what neuronal elements are activated by magnetic stimulation of the human spinal cord. In this study, we demonstrated that transvertebral magnetic stimulation (TVMS) induced transsynaptic activation of spinal motoneuron pools in the lumbar cord. In healthy humans, paired-pulse TVMS was given over an intervertebral space between the L1-L2 vertebrae with an interpulse interval of 100 ms, and the stimulus-evoked electromyographic (EMG) responses were recorded in the lower limb muscles. The results show that the evoked EMG responses after the 2nd pulse were clearly suppressed compared with the widespread responses evoked after the 1st pulse in the muscles of the lower extremity, indicating that the transsynaptic activation of spinal motoneurons by the 2nd pulse was suppressed by the effects produced by the 1st pulse. The inconsistent modulation of response suppression to stimulus intensity across individuals suggests that the TVMS-evoked EMG responses are composed of the compound potentials mediated by the direct activation of motor axons and the transsynaptic activation of motoneuron pools through sensory afferents and that the recruitment order of those fibers by TVMS may be nonhomogeneous across individuals.

Premovement activity in the mesocortical system links peak force but not initiation of force generation under incentive motivation

Motivation facilitates motor performance; however, the neural substrates of the psychological effects on motor performance remain unclear. We conducted a functional magnetic resonance imaging experiment while human subjects performed a ready-set-go task with monetary incentives. Although subjects were only motivated to respond quickly, increasing the incentives improved not only reaction time but also peak grip force. However, the trial-by-trial correlation between reaction time and peak grip force was weak. Extensive areas in the mesocortical system, including the ventral midbrain (VM) and cortical motor-related areas, exhibited motivation-dependent activity in the premovement "Ready" period when the anticipated monetary reward was displayed. This premovement activity in the mesocortical system correlated only with subsequent peak grip force, whereas the activity in motor-related areas alone was associated with subsequent reaction time and peak grip force. These findings suggest that the mesocortical system linking the VM and motor-related regions plays a role in controlling the peak of force generation indirectly associated with incentives but not the initiation of force generation.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Online Adaptive Radiotherapy for Pharyngeal Cancer: Dose-Volume Histogram Analysis between Adapted and Scheduled Plan

PURPOSE/OBJECTIVE(S)

The present study aimed to evaluate whether online adapted plan with artificial intelligence (AI) driven work flow could be used in clinical settings with variable changes of the targets and organs at risk (OARs) for pharyngeal cancer.

MATERIALS/METHODS

Ten patients with pharyngeal cancer who underwent chemoradiotherapy at our institution between January and July 2020 were included for the analysis. All patients had been previously aligned daily with cone-beam computed tomography (CBCT) and treated by O-ring Linac. A simulated treatment was performed on the treatment emulator. Weekly fractions, once in every 4-5 fractions, were simulated in the treatment emulator for each patient using their previous on-treatment CBCTs. The dataset was divided into three groups according to the treatment period (1st-2nd week, 20 CBCTs), middle (3rd-4th week, 20 CBCTs), and late (5th-7th week, 30 CBCTs) period. In the present study, all of reference plan generation in treatment emulator were created on the initial plans of two-step method using 12 equidistant field IMRT. The prescribed dose was 70 Gy in 35 fractions and normalized to the dose of 68.6 Gy (98% dose) to 95% of the planning target volume (PTV). The adaptation process on treatment emulator includes auto-segmentation of daily anatomy, calculation of the dose in scheduled plans using the same monitor units and optimization and calculation of the dose in adapted plan. Dose-volume histogram (DVH) parameters between adapted and scheduled plans in terms of PTV (D98%, D95%, D50% and D2%), spinal cord (Dmax and D1cc), brain stem (Dmax), ipsilateral and contralateral parotid glands (Dmedian and Dmean) were evaluated in each period.

RESULTS

D98% of PTV of adapted plan was significantly higher than that of scheduled plan in early and middle period (p = 0.02 and <0.01, respectively). D95% of PTV of adapted plan was significantly higher than that of scheduled plan in all periods (p<0.01). D2% of PTV of adapted plan was significantly lower than that of scheduled plan in all periods (p = 0.04, 0.04 and 0.02 in each period, respectively). There was not significant difference in D50% of PTV between adapted and scheduled plan in all periods. In terms of OARs, Dmax of spinal cord of adapted plan was significantly lower than that of scheduled plan in all periods (p<0.01). Similarly, D1cc of spinal cord of adapted plan was lower than that of scheduled plan. Dmean of ipsilateral and contralateral parotid glands of adapted plan were lower than those of scheduled plan in the late period (p<0.01 and 0.03, respectively).

CONCLUSION

The present study revealed that adapted plan with AI driven work flow could create dosimetrically better plans for pharyngeal cancer compared to scheduled plan. It was suggested that online adaptive radiotherapy could be necessary to maintain PTV coverage while reducing the dose to OARs in all periods for pharyngeal cancer.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Endothelial Insulin Resistance Exacerbates Experimental Periodontitis

Epidemiological studies suggest that the severity of periodontitis is higher in people with diabetes than in healthy individuals. Insulin resistance might play a crucial role in the pathogenesis of multiple diabetic complications and is reportedly induced in the gingiva of rodents with type 2 diabetes; however, the molecular mechanisms underlying the pathogenesis of diabetes-related periodontitis remain unclear. Therefore, we aimed to investigate whether endothelial insulin resistance in the gingiva may contribute to the pathogenesis of periodontitis as well as elucidate its underlying molecular mechanisms. We demonstrated that insulin treatment downregulated lipopolysaccharide (LPS)-induced or tumor necrosis factor α (TNFα)-induced VCAM1 expression in endothelial cells (ECs) via the PI3K/Akt activating pathway, resulting in reduced cellular adhesion between ECs and leukocytes. Hyperglycemia-induced selective insulin resistance in ECs diminished the effect of insulin on LPS- or TNFα-stimulated VCAM1 expression. Vascular endothelial cell-specific insulin receptor knockout (VEIRKO) mice exhibited selective inhibition of the PI3K/Akt pathway in the gingiva and advanced experimental periodontitis-induced alveolar bone loss via upregulation of Vcam1, Tnfα, Mcp-1, Rankl, and neutrophil migration into the gingiva compared with that in the wild-type (WT) mice despite being free from diabetes. We also observed that insulin-mediated activation of FoxO1, a downstream target of Akt, was suppressed in the gingiva of VEIRKO and high-fat diet (HFD)-fed mice, hyperglycemia-treated ECs, and primary ECs from VEIRKO. Further analysis using ECs transfected with intact and mutated FoxO1, with mutations at 3 insulin-mediated phosphorylation sites (T24A, S256D, S316A), suggested that insulin-mediated regulation of VCAM1 expression and cellular adhesion of ECs with leukocytes was attenuated by mutated FoxO1 overexpression. These results suggest that insulin resistance in ECs may contribute to the progression of periodontitis via dysregulated VCAM1 expression and cellular adhesion with leukocytes, resulting from reduced activation of the PI3K/Akt/FoxO1 axis.

Reorganization of Corticospinal Projections after Prominent Recovery of Finger Dexterity from Partial Spinal Cord Injury in Macaque Monkeys

We investigated morphologic changes in the corticospinal tract (CST) to understand the mechanism underlying recovery of hand function after lesion of the CST at the C4/C5 border in seven macaque monkeys. All monkeys exhibited prominent recovery of precision grip success ratio within a few months. The trajectories and terminals of CST from the contralesional (n = 4) and ipsilesional (n = 3) hand area of primary motor cortex (M1) were investigated at 5-29 months after the injury using an anterograde neural tracer, biotinylated dextran amine (BDA). Reorganization of the CST was assessed by counting the number of BDA-labeled axons and bouton-like swellings in the gray and white matters. Rostral to the lesion (at C3), the number of axon collaterals of the descending axons from both contralesional and ipsilesional M1 entering the ipsilesional and contralesional gray matter, respectively, were increased. Caudal to the lesion (at C8), axons originating from the contralesional M1, descending in the preserved gray matter around the lesion, and terminating in ipsilesional Laminae VI/VII and IX were observed. In addition, axons and terminals from the ipsilesional M1 increased in the ipsilesional Lamina IX after recrossing the midline, which were not observed in intact monkeys. Conversely, axons originating from the ipsilesional M1 and directed toward the contralesional Lamina VII decreased. These results suggest that multiple reorganizations of the corticospinal projections to spinal segments both rostral and caudal to the lesion originating from bilateral M1 underlie a prominent recovery in long-term after spinal cord injury.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Corticospinal interface to restore voluntary control of joint torque in a paralyzed forearm following spinal cord injury in non-human primates

The corticospinal tract plays a major role in the control of voluntary limb movements, and its damage impedes voluntary limb control. We investigated the feasibility of closed-loop brain-controlled subdural spinal stimulation through a corticospinal interface for the modulation of wrist torque in the paralyzed forearm of monkeys with spinal cord injury at C4/C5. Subdural spinal stimulation of the preserved cervical enlargement activated multiple muscles on the paralyzed forearm and wrist torque in the range from flexion to ulnar-flexion. The magnitude of the evoked torque could be modulated by changing current intensity. We then employed the corticospinal interface designed to detect the firing rate of an arbitrarily selected "linked neuron" in the forearm territory of the primary motor cortex (M1) and convert it in real time to activity-contingent electrical stimulation of a spinal site caudal to the lesion. Linked neurons showed task-related activity that modulated the magnitude of the evoked torque and the activation of multiple muscles depending on the required torque. Unlinked neurons, which were independent of spinal stimulation and located in the vicinity of the linked neurons, exhibited task-related or -unrelated activity. Thus, monkeys were able to modulate the wrist torque of the paralyzed forearm by modulating the firing rate of M1 neurons including unlinked and linked neurons via the corticospinal interface. These results suggest that the corticospinal interface can replace the function of the corticospinal tract after spinal cord injury.

Non-invasive brain-spine interface: Continuous control of trans-spinal magnetic stimulation using EEG

Brain-controlled neuromodulation has emerged as a promising tool to promote functional recovery in patients with motor disorders. Brain-machine interfaces exploit this neuromodulatory strategy and could be used for restoring voluntary control of lower limbs. In this work, we propose a non-invasive brain-spine interface (BSI) that processes electroencephalographic (EEG) activity to volitionally control trans-spinal magnetic stimulation (ts-MS), as an approach for lower-limb neurorehabilitation. This novel platform allows to contingently connect motor cortical activation during leg motor imagery with the activation of leg muscles via ts-MS. We tested this closed-loop system in 10 healthy participants using different stimulation conditions. This BSI efficiently removed stimulation artifacts from EEG regardless of ts-MS intensity used, allowing continuous monitoring of cortical activity and real-time closed-loop control of ts-MS. Our BSI induced afferent and efferent evoked responses, being this activation ts-MS intensity-dependent. We demonstrated the feasibility, safety and usability of this non-invasive BSI. The presented system represents a novel non-invasive means of brain-controlled neuromodulation and opens the door towards its integration as a therapeutic tool for lower-limb rehabilitation.

Activation of human spinal locomotor circuitry using transvertebral magnetic stimulation

Transvertebral magnetic stimulation (TVMS) of the human lumbar spinal cord can evoke bilateral rhythmic leg movements, as in walking, supposedly through the activation of spinal locomotor neural circuitry. However, an appropriate stimulus intensity that can effectively drive the human spinal locomotor circuitry to evoke walking-like movements has not been determined. To address this issue, TVMS was delivered over an intervertebral space of the lumbar cord (L1–L3) at different stimulus intensities (10–70% of maximum stimulator output) in healthy human adults. In a stimulus intensity-dependent manner, TVMS evoked two major patterns of rhythmic leg movements in which the left-right movement cycles were coordinated with different phase relationships: hopping-like movements, in which both legs moved in the same direction in phase, and walking-like movements, in which both legs moved alternatively in anti-phase; uncategorized movements were also observed which could not be categorized as either movement type. Even at the same stimulation site, the stimulus-evoked rhythmic movements changed from hopping-like movements to walking-like movements as stimulus intensity was increased. Different leg muscle activation patterns were engaged in the induction of the hopping- and walking-like movements. The magnitude of the evoked hopping- and walking-like movements was positively correlated with stimulus intensity. The human spinal neural circuitry required a higher intensity of magnetic stimulation to produce walking-like leg movements than to produce hopping-like movements. These results suggest that TVMS activates distinct neural modules in the human spinal cord to generate hopping- and walking-like movements.

[Artificial Neural Connection Restores Voluntary Motor Function After Stroke and Spinal Cord Injury]

Artificial neural connection (ANC) establishes an artificial neural pathway to connect distant neuromuscular substrates using a computer interface. Our series of studies have demonstrated three events achieved by ANC. 1)ANC compensated the voluntary motor pathways damaged by stroke and spinal cord injury (SCI). 2)ANC provided a novel function for the neuron to input its information into the ANC. 3)ANC induced plastic changes in the existing neural connectivity between the neural substrates connected by ANC. In the preset literature, we expound the neurophysiological mechanisms underlying the three events and introduce theoretical neural backgrounds in restoring and recovering impaired voluntary locomotor function after stroke and SCI.

The ventral striatum contributes to the activity of the motor cortex and motor outputs in monkeys

The ventral striatum (VSt) is thought to be involved in the vigor of motivated behavior and is suggested to be a limbic-motor interface between limbic areas involved in motivational processes and neural circuits regulating behavioral outputs. However, there is little direct evidence demonstrating the involvement of the VSt in motor control for motivated behaviors. To clarify the functional role of the VSt in motor control, we investigated the effect of reversible pharmacological inactivation of the VSt on the oscillatory activity of the sensorimotor cortices and motor outputs in two macaque monkeys. VSt inactivation reduced movement-related activities of the primary motor cortex and premotor area at 15–120 Hz and increased those at 5–7 Hz. These changes were accompanied by reduced torque outputs but had no effect on the correct performance rate. The present study provides direct evidence that the VSt regulates activities of the motor cortices and motor output.

Development of a radiopaque tiltmeter to improve reproducibility for Fowler's position on chest radiography

INTRODUCTION

We have developed a novel radiopaque tiltmeter (ROT) that can indicate patient tilt during a radiography examination and display it on X-ray images. This study evaluated the effect of variation of patient tilt on the reproducibility of Fowler's position for chest radiography and the accuracy of the ROT.

METHODS

We evaluated the reproducibility of Fowler's position based on changes from the first day in the central venous catheter (CVC) tip position and the cardiothoracic ratio (CTR) with and without a digital tiltmeter to verify its efficacy in patients who underwent mobile chest radiography. The ROT contains radiopaque liquid consisting of white barium sulfate solution and oil and has a scale bar of 15°-75° with increments of 15° to indicate ROT tilt. The ROT tilt was increased from 10° to 80° in increments of 10°. We then evaluated (1) the difference between the ROT tilt and the tilt measured with a digital tiltmeter, and (2) the ROT tilt displayed on the X-ray image.

RESULTS

With regard to reproducibility in Fowler's position, changes in the CVC tip position were 2.8 ± 3.9 mm and 10.7 ± 10.6 mm with and without the tiltmeter, respectively (p < 0.05) and the respective rates of change in the CTR were 0.7% ± 0.6% and 4.0% ± 2.1% (p < 0.05). Differences between the ROT tilt and the tilt measured by the digital tiltmeter were within ±2.5°. All ROT tilts displayed on the X-ray images were recognized exactly as each tilt.

CONCLUSION

Our novel ROT had the potential to accurately indicate patient tilt during chest radiography, which could be helpful in terms of reproducibility and precise follow-up.

IMPLICATIONS FOR PRACTICE

Use of the ROT for determination of patient tilt can improve reproducibility in Fowler's position, allowing more accurate serial X-ray imaging.

Quantitative comparison of corticospinal tracts arising from different cortical areas in humans

The corticospinal tract (CST), which plays a major role in the control of voluntary limb movements, arises from multiple motor- and somatosensory-related areas in monkeys. Although the cortical origin and quantitative differences in CSTs among the cortical areas are well-documented in monkeys, they are unclear in humans. We quantitatively investigated the CSTs from the cerebral cortex to the cervical cord in healthy volunteers using fiber tractography of diffusion-weighted magnetic resonance imaging. The corticospinal (CS) streamlines arose from nine cortical areas: primary motor area (mean ± SD = 49.71 ± 1.61%), dorsal (16.33 ± 1.37%) and ventral (11.02 ± 0.90%) premotor cortex, supplementary motor area (5.14 ± 0.36%), pre-supplementary motor area (2.46 ± 0.26%), primary somatosensory cortex (11.06 ± 0.91%), Brodmann area 5 (0.88 ± 0.09%), caudal cingulate zone (1.70 ± 0.30%), and posterior part of the rostral cingulate zone (1.70 ± 0.34%). In all cortical areas, the number of CS streamlines gradually decreased from the rostral to caudal spinal segments, but the proportion was maintained throughout the cervical cord. Over 75% of CS streamlines arose from the lateral surface of the frontal lobe, which may explain the voluntary control of dexterous and flexible limb movements in humans. (197/200 words).

The dorsal premotor cortex encodes the step-by-step planning processes for goal-directed motor behavior in humans

The dorsal premotor cortex (PMd) plays an essential role in visually guided goal-directed motor behavior. Although there are several planning processes for achieving goal-directed behavior, the separate neural processes are largely unknown. Here, we created a new visuo-goal task to investigate the step-by-step planning processes for visuomotor and visuo-goal behavior in humans. Using functional magnetic resonance imaging, we found activation in different portions of the bilateral PMd during each processing step. In particular, the activated area for rule-based visuomotor and visuo-goal mapping was located at the ventrorostral portion of the bilateral PMd, that for action plan specification was at the dorsocaudal portion of the left PMd, that for transformation was at the rostral portion of the left PMd, and that for action preparation was at the caudal portion of the bilateral PMd. Thus, the left PMd was involved throughout all of the processes, but the right PMd was involved only in rule-based visuomotor and visuo-goal mapping and action preparation. The locations related to each process were generally spatially separated from each other, but they overlapped partially. These findings revealed that there are functional subregions in the bilateral PMd in humans and these subregions form a functional gradient to achieve goal-directed behavior.

Origin of Multisynaptic Corticospinal Pathway to Forelimb Segments in Macaques and Its Reorganization After Spinal Cord Injury

Removal of the monosynaptic corticospinal pathway (CSP) terminating within the forelimb segments severely impairs manual dexterity. Functional recovery from the monosynaptic CSP lesion can be achieved through the remaining multisynaptic CSP toward the forelimb segments. In the present study, we applied retrograde transsynaptic labeling with rabies virus to a monkey model of spinal cord injury. By injecting the virus into the spinal forelimb segments immediately after the monosynaptic CSP lesion, we showed that the contralateral primary motor cortex (M1), especially its caudal and bank region (so-called “new” M1), was the principal origin of the CSP linking the motor cortex to the spinal forelimb segments disynaptically (disynaptic CSP). This forms a striking contrast to the architecture of the monosynaptic CSP that involves extensively other motor-related areas, together with M1. Next, the rabies injections were made at the recovery period of 3 months after the monosynaptic CSP lesion. The second-order labeled neurons were located in the ipsilateral as well as in the contralateral “new” M1. This indicates that the disynaptic CSP input from the ipsilateral “new” M1 is recruited during the motor recovery from the monosynaptic CSP lesion. Our results suggest that the disynaptic CSP is reorganized to connect the ipsilateral “new” M1 to the forelimb motoneurons for functional compensation after the monosynaptic CSP lesion.

A multisynaptic pathway from the ventral midbrain toward spinal motoneurons in monkeys

Abstract

Motivation boosts motor performance. Activity of the ventral midbrain (VM), consisting of the ventral tegmental area (VTA), the substantia nigra pars compacta (SNc) and the retrorubral field (RRF), plays an important role in processing motivation. However, little is known about the neural substrate bridging the VM and the spinal motor output. We hypothesized that the VM might exert a modulatory influence over the descending motor pathways. By retrograde transneuronal labelling with rabies virus, we demonstrated the existence of multisynaptic projections from the VM to the cervical enlargement in monkeys. The distribution pattern of spinal projection neurons in the VM exhibited a caudorostral gradient, in that the RRF and the caudal part of the SNc contained more retrogradely labelled neurons than the VTA and the rostral part of the SNc. Electrical stimulation of the VM induced muscle responses in the contralateral forelimb with a delay of a few milliseconds following the responses of the ipsilateral primary motor cortex (M1). The magnitude and number of evoked muscle responses were associated with the stimulus intensity and number of pulses. The muscle responses were diminished during M1 inactivation. Thus, the present study has identified a multisynaptic VM–spinal pathway that is mediated, at least in part, by the M1 and might play a pivotal role in modulatory control of the spinal motor output.

Key points

Motivation to obtain reward is thought to boost motor performance, and activity in the ventral midbrain is important to the motivational process.

Little is known about a neural substrate bridging the ventral midbrain and the spinal motor output.

Retrograde trans‐synaptic experiments revealed that the ventral midbrain projects multisynaptically to the spinal cord in macaque monkeys.

Ventral midbrain activation by electrical stimulation generated cortical activity in the motor cortex and forelimb muscle activity.

A multisynaptic ventral midbrain–spinal pathway most probably plays a pivotal role in modulatory control of the spinal motor output.

Tuning of motor outputs produced by spinal stimulation during voluntary control of torque directions in monkeys

Spinal stimulation is a promising method to restore motor function after impairment of descending pathways. While paresis, a weakness of voluntary movements driven by surviving descending pathways, can benefit from spinal stimulation, the effects of descending commands on motor outputs produced by spinal stimulation are unclear. Here, we show that descending commands amplify and shape the stimulus-induced muscle responses and torque outputs. During the wrist torque tracking task, spinal stimulation, at a current intensity in the range of balanced excitation and inhibition, over the cervical enlargement facilitated and/or suppressed activities of forelimb muscles. Magnitudes of these effects were dependent on directions of voluntarily produced torque and positively correlated with levels of voluntary muscle activity. Furthermore, the directions of evoked wrist torque corresponded to the directions of voluntarily produced torque. These results suggest that spinal stimulation is beneficial in cases of partial lesion of descending pathways by compensating for reduced descending commands through activation of excitatory and inhibitory synaptic connections to motoneurons.

Assessment of safety of self-controlled repetitive trans-vertebral magnetic stimulation

OBJECTIVE

The aim of this study was to assess safety issues of self-controlled repetitive trans-vertebral magnetic stimulation (rTVMS) in humans.

METHODS

We investigated effects of self-controlled rTVMS (≤20 Hz, ≤90% intensity) on vital signs and subjective sensations in 1690 trials of 30 healthy volunteers and 12 patients with spinal cord disorders.

RESULTS

Healthy volunteers and the patients received 4595 ± 2345, and 4450 ± 2304 pulses in one day, respectively. No serious adverse events were observed in any participants, and only minor events were seen as follows. While blood pressure was unaffected in the patients, the diastolic blood pressure increased slightly after rTVMS in healthy volunteers. The peripheral capillary oxygen saturation increased after rTVMS in healthy volunteers. "Pain" or "Discomfort" was reported in approximately 10% of trials in both participants groups. Degree of the evoked sensation positively correlated with stimulus intensity and was affected by the site of stimulation.

CONCLUSION

Self-controlled rTVMS (≤20 Hz and ≤90% intensity) did not induce any serious adverse effects in healthy volunteers and patients with spinal cord disorders.

SIGNIFICANCE

Our results indicate that rTVMS can be used safely in physiological investigations in healthy volunteers and also as treatment for neurological disorders.

A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests

This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.

Acute circumflex coronary artery occlusion; dilemma in diagnosis and management

Background

Acute coronary syndrome (ACS) with occlusion of the circumflex coronary artery (LCX) poses diagnostic dilemma that may lead to a delay in reperfusion.

Purpose

We sought to assess the diagnostic significance of initial electrocardiography (ECG) changes in patients with acute LCX occlusion in relation to its clinical characteristics and the management.

Methods

From consecutive 1269 patients with ACS who were admitted to our institution during a 5-year period (2015–2019), 138 patients with ACS due to LCX occlusion were analyzed for clinical, ECG and angiographic presentation, and the door-to-balloon (DTB) time. ECG changes were classified into 4 different patterns: 1) ST-elevation in inferior/lateral leads (ST-E); 2) ST-depression in V1-V4 (ST-D); 3) no significant ST changes (No-ST); and 4) others.

Results

(1) No-ST pattern was found in 47 patients (34%), ST-E in 47 patients (34%), ST-D in 25 patients (18%) and others in 19 patients (14%). (2) Occlusion site: Proximal LCX; 16 patients with No-ST (34%), 6 patients with ST-E (13%), 13 patients with ST-D (52%). Distal LCX; 28 patients with No-ST (60%), 35 patients with ST-E (74%), 11 patients with ST-D (44%) (p=0.007). (Table) (3) Echocardiographic identification of left ventricular asynergy; 31 patients with No-ST (66%), 38 patients with ST-E (81%), 22 patients with ST-D (88%). (4) No-ST group was associated with longer DTB time; 245 min (170–562 min), compared to 93 min (83–121 min) in ST-E group and 97 min (70–129 min) in ST-D group (p&lt;0.0001). DTB time ≤90 min was significantly uncommon in No-ST group (11%), compared to ST-E group (46%) and ST-D group (43%) (p=0.0004). (Figure)

Conclusion

One-third of the patients with LCX-ACS showed no ST changes, resulting in significantly longer DTB time. Improving diagnostic accuracy with anticipation for LCX-ACS and the use of echocardiographic examination and also the possible application of posterior leads (V7-V9) recording is challenging but critical to avoid delayed reperfusion and to improve outcomes in these patients without ECG changes.

Funding Acknowledgement

Type of funding sources: None.

Impact of transcatheter aortic valve implantation on coronary flow reserve by transthoracic Doppler echocardiography 1-year after the intervention in severe aortic stenosis patients

Background

Coronary flow reserve (CFR) which is one of indexes reflecting coronary microcirculation in patients without significant epicardial coronary lesions can be impaired in patients with severe aortic stenosis (AS). It has been shown that CFR is an independent predictor for future cardiovascular events in AS patients. Transcatheter aortic valve implantation (TAVI) has rapidly become widespread and is becoming the standard treatment for severe AS. This procedure may have a good effect on CFR due to reduction of severe afterload in patients with severe AS. Although the recent reports evaluated change in CFR immediately and 6 months after TAVI, it has not been evaluated whether impaired CFR improves 1-year after TAVI in AS patients with preserved left ventricular ejection fraction (LVEF).

Purpose

The purpose of the present study was to investigate whether impaired CFR improves 1-year after TAVI in severe AS patients with preserved LVEF.

Methods

The study population consists of consecutive 105 patients with severe AS undergoing TAVI. Exclusion criteria were atrial fibrillation, old myocardial infarction, history of coronary artery bypass grafting, significant lesions in the left anterior descending artery (LAD), moderate or severe mitral valve disease, history of valve replacement, LVEF &lt;50% and preoperative CFR &gt;2.2. CFR was obtained from coronary flow velocity by transthoracic echocardiography at rest and maximal hyperemia in LAD before, immediately and 1-year after TAVI. We compared CFR between before and after TAVI in the study patients who did not meet the exclusion criteria.

Results

After exclusion of 76 patients who met the exclusion criteria, the final study patients consist of 29 patients (8 male, 84.9±5.2 years). There was no significant difference in LVEF (61.3±3.4% vs 61.6±4.4%, P=0.667) and LV end-diastolic volume (LVEDVI; 58.2±9.2 mL/m2 vs 55.8±9.0 mL/m2, P=0.089) between before and immediately after TAVI. LVEF (61.0±2.8%, P=0.721) and LVEDVI (58.0±9.1 mL/m2, P=0.949) 1-year after TAVI were similar to those before TAVI. There was no significant difference in coronary flow velocity at rest between before and immediately after TAVI (27.4±8.9 vs 24.4±7.0 cm/s, P=0.051) and between before and 1-year after TAVI (25.9±8.3 cm/s, P=0.396). Coronary flow velocity at maximal hyperemia 1-year after TAVI significantly increased compared with that before TAVI (from 48.8±13.9 to 67.9±21.0 cm/s, P&lt;0.001) while there was no significant difference between before and immediately after TAVI (52.0±12.0 cm/s, P=0.186). Impaired CFR before TAVI (1.82±0.28) increased immediately (2.03±0.39, P=0.009) and 1-year after TAVI (2.69±0.57, P&lt;0.001).

Conclusions

The present results suggest that impaired CFR in patients with preserved LVEF improves 1-year after TAVI. TAVI may have a good effect on CFR in severe AS patients with preserved LVEF.

Funding Acknowledgement

Type of funding sources: None.

Clinical impact of CREDO-kyoto risk score on in-hospital bleeding in patients with acute coronary syndrome

Background/Introduction

CREDO-Kyoto bleeding risk score was developed to predict the post-discharge bleeding events in patients with percutaneous coronary intervention. However, there were limited reports of the effectiveness of this score to predict the in-hospital bleeding events in patients with acute coronary syndrome (ACS).

Methods

We evaluated 562 consecutive ACS patients in Saga university hospital between 2014 and 2019. Primary outcome was major bleeding during hospitalization. Major bleeding was defined as the GUSTO moderate/severe bleeding. Patients were classified into three groups according to the CREDO-Kyoto bleeding risk score (low, intermediate and high).

Results

Major bleeding events occurred in 12.1% of all patients during hospitalization. Patients in the high risk group (n=22) had significantly higher incidence of major bleeding than those in the intermediate (n=113) and the low risk groups (n=427) (22.7%, 18.6%, versus 9.8%, respectively, p=0.018, see figure). Multivariate analysis showed that intermediate and high risk groups were independent predictors for the in-hospital major bleeding.

Conclusions

CREDO-Kyoto risk score successfully identified high risk ACS patients for the major bleeding during hospitalization.

Funding Acknowledgement

Type of funding sources: None. Results

Absence of microsatellite instability in extramammary Paget's disease

Background

Deficiency of DNA mismatch repair (MMR) induces microsatellite instability (MSI). Pembrolizumab, an antibody targeting PD‐1 (an immune checkpoint inhibitor), is more effective against MMR‐deficient tumours than against MMR‐proficient tumours. The status of MMR is a useful biomarker for predicting the effectiveness of pembrolizumab administration. Although the status of MMR has attracted attention in skin tumours, there are few reports on MSI in extramammary Paget's disease (EMPD).

Objectives

To evaluate the status of MMR in patients with EMPD.

Materials & Methods

One hundred one patients with EMPD were included. MMR status of the genomic DNA of each subject was analysed using Promega panel (approved as a companion diagnostic agent for the administration of pembrolizumab).

Results

MSI testing showed the occurrence rates of MSI‐high (more than two markers are unstable), MSI‐low (one marker is unstable) and MSS (all markers are stable) tumour tissues were 0% (0/101), 1.0% (1/101) and 99.0% (100/101), respectively.

Conclusion

The status of MMR may not be useful for the potential therapeutic application of pembrolizumab.

Changes in beta and high-gamma power in resting-state electrocorticogram induced by repetitive transcranial magnetic stimulation of primary motor cortex in unanesthetized macaque monkeys

Repetitive transcranial magnetic stimulation (rTMS) is now widely used as a means of neuromodulation, but the details of the mechanisms by which rTMS works remain unclarified. As a step forward to unveiling the neural phenomena occurring underneath the TMS coil, we conducted an electrophysiological study using awake and unanesthetized monkeys with subdural electrocorticogram (ECoG) electrodes implanted over the primary motor cortex (MI). We evaluated the effects of low-frequency (1 Hz) and high-frequency (10 Hz) rTMS on the resting-state ECoG signals in the stimulated MI, as well as the motor evoked potentials (MEPs) in the contralateral hand. Following the 1-Hz rTMS application, the ECoG beta band power and the MEP amplitude were significantly decreased. Following the 10-Hz rTMS application, the ECoG high-gamma power and the MEP amplitude significantly increased. Given that beta and high-gamma activities in the ECoG reflect the synchronous firing and the firing frequency of cell assemblies, respectively, in local neural circuits, these results suggest that low-frequency rTMS inhibits neural activity by desynchronizing the firing activity of local circuits, whereas high-frequency rTMS facilitates neural activity by increasing the firing rate of cell assemblies in the local circuits.

Stroke, systemic embolism and bleeding rate in non-valvular atrial fibrillation patients without anticoagulation on the real world data in Japan

Background

Anticoagulant therapy is recommended in patients with non-valvular atrial fibrillation (NVAF) for those with CHADS2 ≥2. However, there have been significant number of subjects with CHADS2 ≥2 who receive no anticoagulation. Most of reported real world data have been collected mainly before wide spread use of DOAC. This study evaluated the clinical outcome of no anticoagulant drug therapy in NVAF.

Methods

This study is a non-interventional, observational, retrospective cohort study of NVAF patients in Mie-LIP Database, which is a regional clinical database joining 1 university hospital and 8 general hospitals in Mie prefecture in Japan. Patient enrolment was conducted from 1st Jan. 2016 to 31st Dec. 2018. The primary outcome events are ischemic stroke, systemic embolism, and bleeding events (bleeding to need a blood transfusion, intracranial bleeding, intraocular bleeding, and gastrointestinal bleeding).

Results

7001 patients were included in the current analysis, 2550 patients, 36.4% were treated without any anticoagulant drug therapy. Table 1 shows patients with no anticoagulant drug therapy, mean age was 75.4 years and 42.2% of patients were female. The most frequent comorbidities included hypertension (50.0%), diabetes mellitus (28.2%), heart failure (14.0%), ischemic stroke (12.7%), vascular disease (14.4%) respectively. The annual incidence of ischemic stroke, systemic embolism per 100 person-years is 3.7, and that in each CHADS2 group is 0: 1.4, 1: 1.4, 2: 3.2, 3–6: 8, respectively in Figure 1. The annual incidence of bleeding events is 1.5, and that in each CHADS2 group is 0: 0.7, 1: 1.0, 2: 1.2, 3–6: 2.9, respectively.

Conclusions

Approximately one-thirds of subjects have not received any anticoagulation in the modern DOAC in daily clinical practice in Japan. The rate of ischemic stroke and systemic embolism increased by CHADS2. Stroke or SEE rate was very low in subjects with CHADS2 ≤1, supporting no indication of anticoagulation in current guidelines. Regarding subjects with CHADS2&gt;2, considering the higher risk of stroke, use of anticoagulant drug therapy is recommended.

Funding Acknowledgement

Type of funding source: None

Relative contributions of large-scale and wedgelet currents in the substorm current wedge

We examined how much large-scale and localized upward and downward currents contribute to the substorm current wedge (SCW), and how they evolve over time, using the THEMIS all-sky imagers (ASIs) and ground magnetometers. One type of events is dominated by a single large-scale wedge, with upward currents over the surge and broad downward currents poleward-eastward of the surge. The other type of events is a composite of large-scale wedge and wedgelets associated with streamers, with each wedgelet having comparable intensity to the large-scale wedge currents. Among 17 auroral substorms with wide ASI coverage, the composite current type is more frequent than the single large-scale wedge type. The dawn-dusk size of each wedgelet is ~ 600 km in the ionosphere (~ 3.2 R _E in the magnetotail, comparable to the flow channel size). We suggest that substorms have more than one type of SCW, and the composite current type is more frequent.

A case of resected retroperitoneal metachronous solitary metastasis from caecal cancer

Colorectal cancer metastasis to the retroperitoneum, especially solitary metastasis allowing curative resection, is rare. We report a case of complete resection of retroperitoneal metachronous solitary metastasis from caecal cancer without distant metastasis. An 80-year-old woman with caecal cancer underwent laparoscopic ileocaecal resection with regional lymph node dissection. According to the eighth edition of the TNM classification, the pathological diagnosis was stage IIA (T3N0M0). Six months following the surgery, computed tomography revealed a solitary mass of 2cm diameter, dorsal to the right kidney. A second procedure for the removal of the tumour was performed. The lesion was pathologically diagnosed as a metachronous solitary retroperitoneal metastasis from caecal cancer. The patient is surviving and free from recurrence 17 months following the second procedure.

0561 Differences in Nasopharyngoscopic Airway Form Between Awake and Sleep, Sitting and Recumbent Position and Techniques

Introduction

To examine and compare the information derived from flexible fiber-optic nasopharyngoscopy in awake mimic snoring (AMS), Müller’s Maneuver (MM) and drug-induced sleep endoscopy (DISE), to determine if AMS and MM can be used in substitution for DISE as a streamlined method. We investigated their relation with the level and pattern of obstruction detected on AMS, MM and DISE.

Methods

This is a retrospective study of 15 obstructive sleep apnea patients with apnea hypopnea index from 8.3 to 105.2, ages 20 to 80 were included. Each patient underwent polysomnography and thorough a physical examination, including flexible nasopharyngoscopy with AMS, MM and DISE. Airway obstruction on these endoscopic procedures were described according to airway level and pattern of obstruction. They were classified 5 different types; Uvula type: anterior-posterior vibration of the uvula, no airway obstruction; L-R velum type: lateral (the left and right directions) airway narrowing at velum level, no airway obstruction; A-P velum type: anterior-posterior total airway obstruction at velum level; Tonsillar type: total airway obstruction at pharyngeal level; Circumferential type: circumferential total airway obstruction at velum level. AMS and MM were performed with patients in sitting and in recumbent position. DISE was performed only in recumbent position.

Results

In review of the three procedures, the results were much different. Airway was obstructed in all cases(100%, 15 of 15)in DISE, but not all cases in AMS and MM. When tonsillar type was seen in AMS, it was also seen in MM and DISE(100%, 5 of 5).

Conclusion

Flexible fiber-optic nasopharyngoscopy appears to be useful for evaluating airway obstruction. It might be not suitable to use AMS and MM in substitution for DISE(except tonsillar type). Muscle tonic relaxation of the upper airway between AMS, MM and DISE might be different (DISE&gt;MM&gt;AMS, recumbent&gt;sitting).

Support

 

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Cerebellar outputs contribute to spontaneous and movement-related activity in the motor cortex of monkeys

Cerebellar outputs originate from the dentate nucleus (DN), project to the primary motor cortex (M1) via the motor thalamus, control M1 activity, and play an essential role in coordinated movements. However, it is unclear when and how the cerebellar outputs contribute to M1 activity. To address this question, we examined the response of M1 neurons to electrical stimulation of the DN and M1 activity during performance of arm-reaching tasks. Based on response patterns to DN stimulation, M1 neurons were classified into facilitation-, suppression-, and no-response-types. During tasks, not only facilitation- and suppression-type M1 neurons, but also no response-type M1 neurons increased or decreased their firing rates in relation to arm reaching movements. However, the firing rates of facilitation- and suppression-type neurons were higher than those of no-response-type neurons during both inter-trial intervals and arm reaching movements. These results imply that cerebellar outputs contribute to both spontaneous and movement-related activity in the M1, which help to maintain muscle tones and execute coordinated movements, although other inputs also contribute to movement-related activity. Pharmacological inactivation of the DN supports this notion, in that DN inactivation reduced both spontaneous firing rates and movement-related activity in the M1.

Stimulus outputs induced by subdural electrodes on the cervical spinal cord in monkeys

OBJECTIVE

Spinal stimulation is a promising method for restoring the function of paralyzed limbs following neurological damage to descending pathways. The present study examined the forelimb movements and muscle responses evoked by subdural spinal stimulation of the cervical cord in sedated monkeys or during an arm-reaching task.

APPROACH

We chronically implanted a platinum subdural electrode array with eight channels over the dorsal-lateral aspect of the cervical enlargement. The electrodes had a diameter of 1 mm and an inter-electrode center-to-center distance of 3 mm. Subdural spinal micro-stimulation was delivered at sites while the monkeys were sedated or performed arm-reaching movements.

MAIN RESULTS

The evoked movements clearly showed the somatotopic map of the output sites; the electrodes located on the rostral cervical cord tended to induce movements of the proximal arm, whereas the caudal electrodes tended to induce movements of the distal joints, such as the wrist and digits. To document the muscle responses evoked by subdural spinal stimulation, stimulus-triggered averages of rectified electromyograms were compiled when the monkeys performed an arm-reaching task or were sedated. Under sedation, evoked facilitative muscle responses were observed in vicinity muscles. In contrast, during the task, stimulation evoked facilitative or suppressive responses in multiple muscles, including those located on proximal and distal joints, while somatotopy became blurred under sedation. Furthermore, stimulation during tasks activated synergistic muscle groups. For example, stimuli strongly facilitated finger extensor muscles, but suppressed the antagonist muscles.

SIGNIFICANCE

These dynamic changes in muscle representation by subdural cervical spinal stimulation between sedated and awake states help our understanding of the nature of spinal circuits and will facilitate the development of neuroprosthetic technology to regain motor function after neural damage to the descending pathways.