scholarly journals Central sensitization increases the pupil dilation elicited by mechanical pinprick stimulation

2019 ◽  
Vol 121 (5) ◽  
pp. 1621-1632 ◽  
Author(s):  
E. N. van den Broeke ◽  
D. M. Hartgerink ◽  
J. Butler ◽  
J. Lambert ◽  
A. Mouraux
Keyword(s):  
Central Sensitization ◽  
High Frequency ◽  
Control Site ◽  
Pupil Dilation ◽  
Autonomic Arousal ◽  
Phasic Response ◽  
Brain Potentials ◽  
Left And Right ◽  
And Control ◽  
Activity Dependent

High-frequency electrical stimulation (HFS) of skin nociceptors triggers central sensitization (CS), manifested as increased pinprick sensitivity of the skin surrounding the site of HFS. Our aim was to assess the effect of CS on pinprick-evoked pupil dilation responses (PDRs) and pinprick-evoked brain potentials (PEPs). We hypothesized that the increase in the positive wave of PEPs following HFS would result from an enhanced pinprick-evoked phasic response of the locus coeruleus-noradrenergic system (LC-NS), indicated by enhanced PDRs. In 14 healthy volunteers, 64- and 96-mN pinprick stimuli were delivered to the left and right forearms, before and 20 minutes after HFS was applied to one of the two forearms. Both PEPs and pinprick-evoked PDRs were recorded. After HFS, pinprick stimuli were perceived as more intense at the HFS-treated arm compared with baseline and control site, and this increase was similar for both stimulation intensities. Importantly, the pinprick-evoked PDR was also increased, and the increase was stronger for 64- compared with 96-mN stimulation. This is in line with our previous results showing a stronger increase of the PEP positivity at 64 vs. 96-mN stimulation and suggests that the increase in PEP positivity observed in previous studies could relate, at least in part, to enhanced LC-NS activity. However, there was no increase of the PEP positivity in the present study, indicating that enhanced LC-NS activity is not the only determinant of the HFS-induced enhancement of PEPs. Altogether, our results indicate that PDRs are more sensitive for detecting CS than PEPs. NEW & NOTEWORTHY We provide the first demonstration in humans that activity-dependent central sensitization increases pinprick-evoked autonomic arousal measured by enhanced pupil dilation response.

scholarly journals Central sensitization increases the pupil dilation elicited by mechanical pinprick stimulation

2018 ◽  
Author(s):  
E.N. van den Broeke ◽  
D.M. Hartgerink ◽  
J Butler ◽  
J Lambert ◽  
A Mouraux
Keyword(s):  
Electrical Stimulation ◽  
Central Sensitization ◽  
High Frequency ◽  
Similar Pattern ◽  
Pupil Size ◽  
Pupil Dilation ◽  
Negative Wave ◽  
Brain Potentials ◽  
Stimulation Intensity ◽  
Brain Responses

ABSTRACTHigh frequency electrical stimulation (HFS) of skin nociceptors triggers central sensitization, manifested as increased pinprick sensitivity of the skin surrounding the site at which HFS was applied. The aim of the present study was to compare the effects of HFS on pupil dilation and brain responses elicited by pinprick stimulation delivered in the area of increased pinprick sensitivity. In fourteen healthy volunteers HFS was applied to one of the two forearms. Before and twenty minutes after applying HFS, mechanical pinprick stimuli (64 mN and 96 mN) were delivered to the area surrounding the site at which HFS was applied as well as the contralateral control arm. During pinprick stimulation both the pupil size and electroencephalogram were recorded. HFS induced a clear and comparable increase in pinprick sensitivity for both the 64 and 96 mN stimulation intensity. Both pinprick stimulation intensities elicited a greater pupil dilation response when delivered to the area of increased pinprick sensitivity. However, this greater pupil dilation response was larger for the 64 mN compared to the 96 mN stimulation intensity. A similar pattern was observed for the negative wave of the pinprick-evoked brain potentials (PEPs), however, the increase was not significant for the 96 mN and showed only a trend towards significance for the 64 mN. These results show that there is a correspondence between the increase in pupil dilation and the increase in PEPs, but that pupil size is a more sensitive measure for detecting the effects of central sensitization than PEPs.

Case study: Simulation and control of high frequency noise for commercial vehicle cab considering leak

2019 ◽  
Vol 67 (4) ◽  
pp. 315-329
Author(s):  
Rongjiang Tang ◽  
Zhe Tong ◽  
Weiguang Zheng ◽  
Shenfang Li ◽  
Li Huang
Keyword(s):  
High Frequency ◽  
Commercial Vehicle ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Simulation And Control ◽  
And Control

A Retrospective Study to Evaluate the Efficacy of a Plasma Energy System (Renuvion) in the Management of Skin Laxity to Improve Tightening at the Time of Standard Liposuction of the Arms

2021 ◽  
pp. 074880682110310
Author(s):  
Angelo Cuzalina ◽  
Pasquale G. Tolomeo
Keyword(s):  
Upper Extremity ◽  
Control Site ◽  
Clinical Staff ◽  
Upper Extremities ◽  
Final Visit ◽  
Recipient Site ◽  
Skin Laxity ◽  
Plasma Energy ◽  
Treatment Site ◽  
And Control

The aim of this study was to determine the efficacy of cool atmospheric plasma (Renuvion/J-plasma) in promoting skin tightening and soft tissue contouring following liposuction of the upper extremities. The study was a retrospective review of upper extremity liposuction with associated Renuvion therapy performed by the same surgeon. Patients were made aware of Renuvion therapy to assist with skin laxity and offered adjunctive treatment following liposuction. While a majority of patients elected to have Renuvion therapy performed bilaterally, a small subset of patients elected for unilateral treatment. This subset of patients pursued delayed treatment on the control side. The inclusion criteria for the study included patients with moderate fat excess of the upper extremity with associated mild to moderate cutaneous laxity. Exclusion criteria for the study included severe medical comorbidities, body mass index greater than 35 kg/m2 and those below the age of 30. The study included 5 female patients between the ages of 46 to 52. The method of treatment was liposuction of the bilateral upper extremities with removal of equal proportions of fat. The recipient site for Renuvion treatment was randomly selected by the study coordinator; the surgeon and clinical staff remained blinded to the selection. Following treatment, the patients were evaluated at 1 week, 6 weeks, and 6 months postoperatively to assess surgical outcomes subjectively. The surgeon and clinical staff were unblinded at the final visit. Patients were evaluated based on subjective criteria and photographic evaluation at each postoperative visit. At the 1-week visit, no significant differences were noted in all subjects. At the 6-week visit, two patients demonstrated improved results to the treatment site when compared with the control site. At the 6-month visit, four out of the five patients demonstrated a significant improvement in contour and laxity at the treatment site when compared with the control site. One patient demonstrated equal results on both treatment and control sites with no major abnormalities. Following the final evaluation, the patients underwent a secondary procedure to the control site with Renuvion to obtain similar results as the recipient site. One patient demonstrated equal results on both test and control sites with no major abnormalities. The use of plasma energy via Renuvion in conjunction with liposuction has demonstrated esthetic results with proposed long-term benefits. The plasma energy device, as an adjuvant therapy, may be beneficial in cases where liposuction alone may not address tissue laxity concerns. Additional studies with a larger sample size, objective criteria, and extended follow-ups are necessary to statistically analyze the results and determine its significance.

Somatosensory Evoked Potentials in Schizophrenia a Lateralisation Study

1990 ◽  
Vol 157 (6) ◽  
pp. 881-887 ◽  
Author(s):  
Paul Furlong ◽  
Paul Barczak ◽  
Gwilym Hayes ◽  
Graham Harding
Keyword(s):  
Index Finger ◽  
Objective Measure ◽  
Control Group ◽  
Temporal Region ◽  
Control Groups ◽  
Significant Difference ◽  
Schizophrenic Patients ◽  
Left And Right ◽  
And Control ◽  
Stimulation Of

The SSEPs obtained from 19 schizophrenics defined by RDC, DSM–III and PSE criteria Were compared with those from a control group of healthy volunteers. Previous findings of an abnormal lack of lateralising response in schizophrenic patients were not replicated. No significant difference in either amplitude or morphology between the traces obtained from the two groups were recorded. Ipsilateral and contralateral latencies for stimulation of the left and right index finger showed no significant difference in peak latency for any component between patient and control group. When mean peak-to-peak amplitudes were plotted the contralateral component was always greater in amplitude than the ipsilateral one. An objective measure of the degree of lateralisation, the percentage lateralisation quotient, showed no lateralisation differences between the patient and control groups. A case of myogenic contamination of ipsilateral components was observed calling into doubt findings where no temporal region monitoring has been performed.

Testing of Sonic-Absorbent Panels’ Behavior in Open-Air Environment

2012 ◽  
Author(s):  
Petru A. Pop ◽  
Patricia A. Ungur ◽  
Liviu Lazar ◽  
Mircea Gordan ◽  
Florin M. Marcu
Keyword(s):  
High Frequency ◽  
Noise Pollution ◽  
Sound Level ◽  
Sound Level Meter ◽  
Data Logger ◽  
Public Buildings ◽  
Gypsum Plaster ◽  
Level Meter ◽  
And Control

One wildly used method to reduce and control the noise pollution in green city’s buildings is using sonic-absorbent panels. Their applications can be multiple, such as the insulation of buildings, acoustic barriers and fences along the highway or in front of supermarkets, hospitals and other public buildings. This paper presents a method for testing the behavior of sonic-absorbent panels in open-air environment. The work represents a carrying on of previous research about absorbent materials from gypsum family, tested in lab conditions. The experiment setup used a dynamic installation and as a sample a stand formed by six sonic-absorbent panels from special modeling alpha-gypsum plaster. This installation has been composed of two loudspeakers for emitting the sound at a well-defined frequency by the first laptop, the microphone for detecting and transmitting the signal to the second laptop for analyzing and processing the data. All operations were performed using MATLAB Programs, while a Data Logger Sound Level Meter type CENTER 332 was put on near the microphone to compare both results. The first experiment of acoustic stand has been realized by setting up the installation at a frequency from 50 Hz to 1250 Hz and altering the distance between loudspeakers and stand at 0.5m to 1m and 1.5m, respectively. The second experiment kept the same test’s conditions, while two and three layers of sonic-absorbent panels formed the stand, respectively, but at same distance from source of 0.5 m. In both tests, the results underlined the good sonic-absorbent properties of these panels, especially at medium and high frequency, which can recommend using the panels for multiple outside applications.

Effects of sea urchin and herbivorous gastropod removal, coupled with transplantation, on seaweed forest restoration

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Seokwoo Hong ◽  
Junsu Kim ◽  
Young Wook Ko ◽  
Kwon Mo Yang ◽  
Daniela Macias ◽  
...  
Keyword(s):  
Forest Restoration ◽  
Control Site ◽  
Eastern Coast ◽  
First Year ◽  
Survey Period ◽  
Red Algal ◽  
Rapid Restoration ◽  
Experimental Treatments ◽  
And Control ◽  
Herbivorous Gastropods

Abstract This study aims to investigate the relative effects of urchin removal, non-urchin gastropod herbivores removal, and transplantation on macroalgal forest restoration using an additive manipulation design. A field experiment was conducted in subtidal urchin barren rocks in the eastern coast of South Korea from August 2017 to June 2020 with three experimental treatments: no urchins (NU), NU plus no herbivorous gastropods (NH), NH plus Ecklonia bicyclis transplant (NHT). Six months after experiment initiation, seaweed abundance rapidly increased in all three experimental treatments. The highest peak was found in the spring season of the first year (2018). The year-to-year variations became smaller throughout the survey period. The results of comparing NU and control site indicated that urchin removal had an exclusive effect on algal recovery while additional removal of herbivorous gastropods did not affect algal recovery quantitatively. With the successful establishment of E. bicyclis, the community assemblages of the three treatments became more distinct in the subsequent years, showing diverse dominance in NU, red algal dominance in NH, and dominance of E. bicyclis canopy and understory groups in NHT. This study provides evidence that urchin removal on its own from barren grounds can lead to rapid restoration of seaweed forest in subtidal habitats.

scholarly journals Minimal role for H1 and H2 histamine receptors in cutaneous thermal hyperemia to local heating in humans

2006 ◽  
Vol 100 (2) ◽  
pp. 535-540 ◽  
Author(s):  
Brett J. Wong ◽  
Sarah J. Williams ◽  
Christopher T. Minson
Keyword(s):  
Blood Flow ◽  
Receptor Antagonist ◽  
Skin Blood Flow ◽  
Local Heating ◽  
Histamine Receptor ◽  
Receptor Activation ◽  
Control Site ◽  
Doppler Flowmetry ◽  
Histamine Receptor Antagonist ◽  
And Control

The precise mechanism(s) underlying the thermal hyperemic response to local heating of human skin are not fully understood. The purpose of this study was to investigate a potential role for H1 and H2 histamine-receptor activation in this response. Two groups of six subjects participated in two separate protocols and were instrumented with three microdialysis fibers on the ventral forearm. In both protocols, sites were randomly assigned to receive one of three treatments. In protocol 1, sites received 1) 500 μM pyrilamine maleate (H1-receptor antagonist), 2) 10 mM l-NAME to inhibit nitric oxide synthase, and 3) 500 μM pyrilamine with 10 mM NG-nitro-l-arginine methyl ester (l-NAME). In protocol 2, sites received 1) 2 mM cimetidine (H2 antagonist), 2) 10 mM l-NAME, and 3) 2 mM cimetidine with 10 mM l-NAME. A fourth site served as a control site (no microdialysis fiber). Skin sites were locally heated from a baseline of 33 to 42°C at a rate of 0.5°C/5 s, and skin blood flow was monitored using laser-Doppler flowmetry (LDF). Cutaneous vascular conductance was calculated as LDF/mean arterial pressure. To normalize skin blood flow to maximal vasodilation, microdialysis sites were perfused with 28 mM sodium nitroprusside, and control sites were heated to 43°C. In both H1 and H2 antagonist studies, no differences in initial peak or secondary plateau phase were observed between control and histamine-receptor antagonist only sites or between l-NAME and l-NAME with histamine receptor antagonist. There were no differences in nadir response between l-NAME and l-NAME with histamine-receptor antagonist. However, the nadir response in H1 antagonist sites was significantly reduced compared with control sites, but there was no effect of H2 antagonist on the nadir response. These data suggest only a modest role for H1-receptor activation in the cutaneous response to local heating as evidenced by a diminished nadir response and no role for H2-receptor activation.

Rate-dependent shortening of action potential duration increases ventricular vulnerability in failing rabbit heart

2011 ◽  
Vol 300 (2) ◽  
pp. H565-H573 ◽  
Author(s):  
Masahide Harada ◽  
Yukiomi Tsuji ◽  
Yuko S. Ishiguro ◽  
Hiroki Takanari ◽  
Yusuke Okuno ◽  
...  
Keyword(s):  
Action Potential ◽  
High Frequency ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
High Frequency Stimulation ◽  
Electrophysiological Properties ◽  
Rate Dependent ◽  
Frequency Stimulation ◽  
And Control

Congestive heart failure (CHF) predisposes to ventricular fibrillation (VF) in association with electrical remodeling of the ventricle. However, much remains unknown about the rate-dependent electrophysiological properties in a failing heart. Action potential properties in the left ventricular subepicardial muscles during dynamic pacing were examined with optical mapping in pacing-induced CHF ( n = 18) and control ( n = 17) rabbit hearts perfused in vitro. Action potential durations (APDs) in CHF were significantly longer than those observed for controls at basic cycle lengths (BCLs) >1,000 ms but significantly shorter at BCLs <400 ms. Spatial APD dispersions were significantly increased in CHF versus control (by 17–81%), and conduction velocity was significantly decreased in CHF (by 6–20%). In both groups, high-frequency stimulation (BCLs <150 ms) always caused spatial APD alternans; spatially concordant alternans and spatially discordant alternans (SDA) were induced at 60% and 40% in control, respectively, whereas 18% and 82% in CHF. SDA in CHF caused wavebreaks followed by reentrant excitations, giving rise to VF. Incidence of ventricular tachycardia/VFs elicited by high-frequency dynamic pacing (BCLs <150 ms) was significantly higher in CHF versus control (93% vs. 20%). In CHF, left ventricular subepicardial muscles show significant APD shortenings at short BCLs favoring reentry formations following wavebreaks in association with SDA. High-frequency excitation itself may increase the vulnerability to VF in CHF.

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