Contraction Threshold Research Articles

Exploring the high-quality ingredients and mechanisms of Da Chuanxiong Formula in the treatment of neuropathic pain based on network pharmacology, molecular docking, and molecular dynamics simulation

Da Chuanxiong Formula (DCXF) is a traditional herbal prescription used for pain management. It consists of Chuanxiong Rhizoma (CR) and Gastrodiae Rhizoma (GR). Despite its long history of use, the underlying therapeutic mechanism of DCXF remains insufficiently understood. Therefore, in this study, key target genes were obtained through network pharmacology research methods and molecular docking techniques, including transient receptor potential vanilloid 1 (TRPV1), adenosine A2a receptor (ADORA2A), nuclear receptor subfamily 3 group C member 1 (NR3C1), and protein kinase C beta (PRKCB). Molecular dynamics simulations demonstrated the favorable binding between all four key genes and their corresponding compounds. Notably, chronic constriction injury (CCI) treatment resulted in a significant decrease in mechanical threshold and thermal latency period for rat foot contraction, which was ameliorated upon administration of DCXF. Furthermore, real-time quantitative reverse transcription PCR (RT-qPCR) and western blot (WB) analyses indicated an upregulation of TRPV1, ADORA2A, NR3C1, and PRKCB expression in the rat dorsal root ganglion following CCI, which was attenuated by treatment with DCXF. The expressions of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6), in the rat dorsal root ganglion were assessed using ELISA, confirming consistent trends with the aforementioned findings. The results of this study offer a promising theoretical foundation for the utilization of DCXF in the treatment of neuropathic pain (NP).

A Quantitative Investigation of Mental Fatigue Elicited during Motor Imagery Practice: Selective Effects on Maximal Force Performance and Imagery Ability.

In the present study, we examined the development of mental fatigue during the kinesthetic motor imagery (MI) of isometric force contractions performed with the dominant upper limb. Participants (n = 24) underwent four blocks of 20 MI trials of isometric contractions at 20% of the maximal voluntary contraction threshold (20% MVCMI) and 20 MI trials of maximal isometric contractions (100% MVCMI). Mental fatigue was assessed after each block using a visual analogue scale (VAS). We assessed maximal isometric force before, during and after MI sessions. We also assessed MI ability from self-report ratings and skin conductance recordings. Results showed a logarithmic pattern of increase in mental fatigue over the course of MI, which was superior during 100% MVCMI. Unexpectedly, maximal force improved during 100% MVCMI between the 1st and 2nd evaluations but remained unchanged during 20% MVCMI. MI ease and vividness improved during 100% MVCMI, with a positive association between phasic skin conductance and VAS mental fatigue scores. Conversely, subjective measures revealed decreased MI ability during 20% MVCMI. Mental fatigue did not hamper the priming effects of MI on maximal force performance, nor MI's ability for tasks involving high physical demands. By contrast, mental fatigue impaired MI vividness and elicited boredom effects in the case of motor tasks with low physical demands.

A Model-Driven Channel Estimation Method for Millimeter-Wave Massive MIMO Systems

Aiming at the problem of low estimation accuracy under a low signal-to-noise ratio due to the failure to consider the "beam squint" effect in millimeter-wave broadband systems, this paper proposes a model-driven channel estimation method for millimeter-wave massive MIMO broadband systems. This method considers the "beam squint" effect and applies the iterative shrinkage threshold algorithm to the deep iterative network. First, the millimeter-wave channel matrix is transformed into a transform domain with sparse features through training data learning to obtain a sparse matrix. Secondly, a contraction threshold network based on an attention mechanism is proposed in the phase of beam domain denoising. The network selects a set of optimal thresholds according to feature adaptation, which can be applied to different signal-to-noise ratios to achieve a better denoising effect. Finally, the residual network and the shrinkage threshold network are jointly optimized to accelerate the convergence speed of the network. The simulation results show that the convergence speed is increased by 10% and the channel estimation accuracy is increased by 17.28% on average under different signal-to-noise ratios.

Antagonistic Effect and Mechanism of Gabapentin on Neuropathic Pain in Rats through P38 MAPK Signaling Pathway.

The etiology of neuropathic pain is complex, and the patients are distressed. In order to master more accurate information in the treatment of human nerve tissue and improve the efficiency of treatment, this paper discusses the antagonistic effect of gabapentin on neuropathic pain in rats through the p38 MAPK signal pathway. Thirty-six female Sprague Dawley (SD) rats were randomly divided into three groups, 12 in each group. One group was spinal nerve ligation group (SNL group), gabapentin Group (GBP group, spinal nerve ligation and intraperitoneal injection of gabapentin (50 mg/kg)) and sham operation group (sham group, no spinal nerve ligation, other surgical procedures were the same as SNL group), At 1, 3, 5 and 7 days after operation, the paw contraction latency (TWL) and mechanical paw contraction threshold (MWT) were detected. Then, the expression of Toll-like receptor 4 (TLR4) in dorsal root ganglia was detected by SPSS statistical analysis. Compared with the sham group, MWT and TWL in the SNL group and GBP group were lower at each time point after the operation (all P < 0.05). MWT and TWL in the GBP group were higher than those in the SNL group at 5 and 7 days after the operation (all P < 0.05). In addition, compared with the sham group, the expression of TLR4 in the dorsal root ganglia of the SNL group was significantly increased (P < 0.05), while the expression of TLR4 in the GBP group was not significantly increased (P > 0.05). Compared with the SNL group, the expression of TLR4 in the dorsal root ganglion of the GBP group was significantly decreased (P < 0.05). Thus, gabapentin combined therapy can effectively reduce the degree of pain in patients with significant efficacy, high safety and fewer adverse reactions.

Study on the Mechanism of Electroacupuncture in the Treatment of Neuropathic Pain Based on Vesicular Glutamate Transporter 2/Toll Like Receptor 4 Signal Pathway

To explore the analgesic effect of electro-acupuncture on neuropathic pain model rats and to clarify the mechanism of electro-acupuncture analgesia from the perspective of vesicular glutamate transporter 2/toll like receptor 4 signal pathway. A total of 30 specific pathogen free grade adult male Sprague-Dawley rats were selected. The rats were randomly divided into model group (chronic constriction injury), sham operation group, electro-acupuncture group, non-electro-acupuncture group (sham electro-acupuncture), Chicago sky blue 6B group and lipopolysaccharide group, with 5 rats in each group. The neuropathic pain model of chronic constriction injury of sciatic nerve was established. The “Huantiao” and “Yanglingquan” points were selected for electroacupuncture stimulation for 14 d. The mechanical foot contraction threshold, thermal pain, vesicular glutamate transporter 2/toll like receptor 4 signal pathway protein levels and inflammatory factor level of rats in each group were compared and analyzed. Compared with the sham operation group, the mechanical pain and thermal pain thresholds of the model group decreased significantly (p<0.01), the unilateral levels of vesicular glutamate transporter 2 and toll like receptor 4 and the release of interalukin-6 in the spinal cord increased significantly (p<0.01), while interalukin-10 decreased significantly (p<0.01); compared with the model group, electroacupuncture and intrathecal injection of Chicago sky blue 6B could significantly increase the pain threshold of neuropathic pain rats (p<0.01), reduce the release of interalukin-6 and the level of vesicular glutamate transporter 2 protein in the spinal cord and increase the level of interlukin-10; intrathecal injection of lipopolysaccharide decreased the pain threshold in rats (p<0.01). Electro-acupuncture can alleviate the pain sensitivity of neuropathic pain rats and its occurrence and development is closely related to the activation of vesicular glutamate transporter 2/toll like receptor 4 signal pathway in the spinal dorsal horn.

Downregulation of Soluble Guanylate Cyclase and Protein Kinase G in the Pulmonary Artery Leads to the Sensitization to Thromboxane A2 in the Monocrotaline‐induced Pulmonary Hypertensive Rats

Thromboxane A2(TXA2) relates to physiological and pathophysiological conditions of pulmonary artery (PA). Here, we examined the role of TXA2 receptor (TP)-mediated signaling in the pathophysiology of pulmonary arterial hypertension (PAH). The responsiveness to contractile agonist in PA could be determined by signals related to vasodilation such as nitric oxide (NO), soluble guanylate cyclase (sGC) and cGMP-dependent kinase (PKG) pathway. In this study, the TP receptor agonist (U46619)-induced contraction and modulatory role of NO/cGMP signaling were investigated in a monocrotaline-induced PAH rat model (PAH-MCT). PA from PAH-MCT exhibited higher sensitivity to U46619, that is decreased EC50. Lower expression of eNOS, sGC, and PKG were observed while higher expression of RhoA-dependent kinase 2 (ROCK2) was revealed by immunoblot analysis in the PA from PAH-MCT and control. The higher sensitivity to U46619 in PAH-MCT was ameliorated by 8-Br-cGMP, a membrane-permeable cGMP analogue, but not by NO donor, sodium nitroprusside (SNP 30 µM). In contrast, in the control PA, sGC inhibition by 1H- [1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) 10 µM lowered the threshold of U46619-induced contraction. In the presence of ODQ, SNP treatment did not present its regulatory effect whereas the addition of 8-Br-cGMP lowered the sensitivity to U46619. The inhibition of ROCK by Y-27632 also lowered the sensitivity to U46619 in both control and PAH-MCT. The study suggests that the attenuation of NO/cGMP signaling and the upregulation of ROCK2 increase the sensitivity to TXA2 in the PAH animal, which might have pathophysiological implications in patients with PAH.

Downregulation of Soluble Guanylate Cyclase and Protein Kinase G With Upregulated ROCK2 in the Pulmonary Artery Leads to Thromboxane A2 Sensitization in Monocrotaline-Induced Pulmonary Hypertensive Rats.

Thromboxane A2 (TXA2) promotes various physiological responses including pulmonary artery (PA) contraction, and pathophysiological implications have been suggested in cardiovascular diseases including pulmonary hypertension. Here, we investigated the role of TXA2 receptor (TP)-mediated signaling in the pathophysiology of pulmonary arterial hypertension (PAH). The sensitivity of PA to the contractile agonist could be set by relaxing signals such as the nitric oxide (NO), soluble guanylate cyclase (sGC), and cGMP-dependent kinase (PKG) pathways. Changes in the TP agonist (U46619)-induced PA contraction and its modulation by NO/cGMP signaling were analyzed in a monocrotaline-induced PAH rat model (PAH-MCT). In the myograph study, PA from PAH-MCT showed higher responsiveness to U46619, that is decreased EC50. Immunoblot analysis revealed a lower expression of eNOS, sGC, and PKG, while there was a higher expression of RhoA-dependent kinase 2 (ROCK2) in the PA from PAH-MCT than in the control. In PAH-MCT, the higher sensitivity to U46619 was reversed by 8-Br-cGMP, a membrane-permeable cGMP analog, but not by the NO donor, sodium nitroprusside (SNP 30 μM). In contrast, in the control PA, inhibition of sGC by its inhibitor (1H− [1,2,4] oxadiazolo [4,3−a] quinoxalin-1-one (ODQ), 10 μM) lowered the threshold of U46619-induced contraction. In the presence of ODQ, SNP treatment had no effect whereas the addition of 8-Br-cGMP lowered the sensitivity to U46619. The inhibition of ROCK by Y-27632 attenuated the sensitivity to U46619 in both control and PAH-MCT. The study suggests that the attenuation of NO/cGMP signaling and the upregulation of ROCK2 increase the sensitivity to TXA2 in the PAH animal, which might have pathophysiological implications in patients with PAH.

Exploring Localized Muscle Fatigue Responses at Current Upper-Extremity Ergonomics Threshold Limit Values.

The purpose of this study was to evaluate localized muscle fatigue responses at three upper-extremity ergonomics threshold limit value (TLV) duty cycles. Recently, a TLV equation was published to help mitigate excessive development of localized muscle fatigue in repetitive upper limb tasks. This equation predicts acceptable levels of maximal voluntary contraction (% MVC) for a given duty cycle (DC). Experimental validation of this TLV curve has not yet been reported, which can help guide utilization by practitioners. Eighteen participants performed intermittent isometric elbow flexion efforts, in three separate counter-balanced sessions, at workloads defined by the American Conference of Governmental Industrial Hygenists' (ACGIH) TLV equation: low DC (20% DC, 29.6% MVC), medium DC (40% DC, 19.7% MVC), and high DC (60% DC, 13.9% MVC). Targeted localized muscle fatigue (LMF) of the biceps brachii was tracked across numerous response variables, including decline in strength (MVC), electromyography (EMG) amplitude and mean power frequency (MnPF), and several psychophysical ratings. At task completion, biceps MnPF and MVC (strength) were significantly different between each TLV workload, with the high DC condition eliciting the largest declines in MnPF and MVC. Findings demonstrate that working at different DCs along the ACGIH TLV curve may not be equivalent in preventing excessive LMF. Higher DC workloads elicited a greater LMF response across several response variables. High DC work of the upper extremity should be avoided to mitigate excess LMF development. Current TLVs for repetitive upper-extremity work may overestimate acceptable relative contraction thresholds, particularly at higher duty cycles.

Analgesic effect of flurbiprofen ester and its effect on serum inflammatory factors and Β-endorphin expression in rats with incision pain

Purpose: To study the analgesic effect of flurbiprofen ester in rats with incision pain, and its effect on serum inflammatory factors and β-endorphin expression.&#x0D; Methods: Seventy-five (75) healthy rats with foot contraction threshold induced by basic mechanical stimulation were randomly assigned to control, model control and treatment groups. Flurbiprofen was administered in 3 doses: 5, 10 and 15 mg/kg. Then, 3 mL of ventricular blood was taken from anesthetized rats and the serum levels of tumor necrosis factor-α (TNF- α), interleukin-1 β, interleukin-6 and β-endorphin were measured. The expression of β-endorphin in the spinal cord of rats with lumbar enlargement and ARC was determined.&#x0D; Results: The TNF- α, interleukin-1 β and interleukin-6 concentrations were significantly lower in treatment group than in model rats, and decreased with time and dose (p &lt; 0.05). In the treatment group, the level of serum β-endorphin decreased with increase in dose at 1 h, but increased with increase in dose at 5 h and 10 h (p &lt; 0.05). The levels of β-endorphin in the spinal cord, was significantly lower in model rats than in control rats (p &lt; 0.05).&#x0D; Conclusion: Pre-administration of flurbiprofen ester reduces serum inflammatory factors and upregulates β-endorphin expression in rats with incision pain. Thus, it flurbiprofen exerts analgesic effect.&#x0D; Keywords: Flurbiprofen ester, Incision pain, Rat, Analgesia, Inflammatory factor, β-endorphin

MP28-15 EFFECTS OF SINGLE BOUT ACUTE INTERMITTENT HYPOXIA PROTOCOLS ON REFLEX MICTURITION IN NAIVE AND SPINAL CORD-INJURED ADULT RATS

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology I (MP28)1 Apr 2020MP28-15 EFFECTS OF SINGLE BOUT ACUTE INTERMITTENT HYPOXIA PROTOCOLS ON REFLEX MICTURITION IN NAIVE AND SPINAL CORD-INJURED ADULT RATS William Collins*, Christine Wang, and Irene Solomon William Collins*William Collins* More articles by this author , Christine WangChristine Wang More articles by this author , and Irene SolomonIrene Solomon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000867.015AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Acute intermittent hypoxia (AIH) has been suggested as a potential therapy in spinal cord injury (SCI) since it can induce neural plasticity in both respiratory and non-respiratory somatic motor systems. Implementing the most commonly used AIH protocol consisting of a single bout of three 5-min episodes of hypoxia, we have previously demonstrated that AIH produces a sustained decrease in the frequency of reflex micturition events (rME) accompanied by an increase in micturition volume in both naïve rats and rats with moderate SCI as well as a sustained decrease in the frequency of non-voiding contractions in SCI rats. In the present study, we examine the effects of different single bout AIH protocols that keep the total duration of hypoxia (15 min) constant but differ in timing and number of hypoxic episodes on lower urinary tract (LUT) function in naïve and SCI rats. METHODS: We assessed the effects of three single bout AIH protocols on bladder intravesical pressure (BP) and void volume recorded under urethane anesthesia (1.4 g/kg) in naïve and mid-thoracic moderate contusion SCI (4-week survival) rats during continuous infusion of saline (0.04 ml/min) into the bladder to elicit rMEs. The AIH protocols implemented consisted of alternating exposures of hypoxia (12% O2) and normoxia using the following: (1) three 5-min episodes, (2) five 3-min episodes, and (3) ten 1.5-min episodes. Following the AIH exposure, data acquisition continued for up to 120 minutes while the rats continued to breathe room air. RESULTS: In both naïve and SCI rats, each single bout AIH protocol produced a comparable decrease in rME frequency and increase in void volume that persisted for up 120 min post-AIH. Moreover, in SCI rats, each of the protocols was equally effective in reducing the ratio of non-voiding/voiding bladder contractions. Single bout AIH exposure also produced transient increases in both bladder contraction threshold BP and minimum BP. Modulation of LUT behavior during individual exposures to hypoxia and immediately following each hypoxic episode (“off effect”) were also observed, with the intensity of the “off effect” tending to be lower following short duration (e.g., 10 x 1.5-min) hypoxic exposures. CONCLUSIONS: Our observations suggest that while each single bout AIH protocol is effective in improving micturition and reducing non-voiding bladder contractions in SCI rats, subtle differences in magnitude and/or timing were noted across the protocols. Source of Funding: DOD CDMRP W81XWH-17-1-0260; NIH NS096514 © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e425-e426 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information William Collins* More articles by this author Christine Wang More articles by this author Irene Solomon More articles by this author Expand All Advertisement PDF downloadLoading ...

Evaluation of the dose-response for electrostimulation with Aussie current in the core strength

Introduction. Muscle strengthening to improve joint stability is widely used in the rehabilitation process, and the use of neuromuscular electrical stimulation is a useful tool, but the use of Aussie current still has little documentation about its effectiveness. Aim. To verify if there is a dose-response effect to Aussie current, both in the strength and in the static and dynamic stability of the deep pelvic lumbar muscles. Material and methods. 39 volunteers divided into four groups, one control and three electrostimulation with intensity variation, one with intensity at the contraction threshold (GT), another with intensity maintained at 20% more (G20), and another with intensity maintained at 30% more (G30) than the intensity at the contraction threshold. The intervention lasted four weeks, with three weekly sessions lasting 15 minutes. Initially and after the intervention period, the strength and stability of the deep muscles of the pelvic lumbar region were measured in a static and dynamic manner by a biofeedback pressure unit. Results. There was a significant increase of pressure under the lordoses in the pre- and post-evaluation moments, there were no differences in the evaluation of indirect force (dynamic stability), but there was an increase in the time for GT. The effect sizes presented advantages for the electrostimulated groups in static stability. Conclusion. The doses used did not promote significant statistical differences, but the effects were positive for the electrostimulated groups, especially with respect to static stability.

Mechanical analysis of intestinal contractility in a neonatal maternal deprivation irritable bowel syndrome rat model

The aims of the present study are to investigate biomechanical properties and provide mechanical analysis of contractility in ileum and colon in a neonatal maternal deprivation (NMD) irritable bowel syndrome (IBS) rat model. Mechanical testing was done on segments from ileum and colon in 25 IBS rats and 13 Control rats. Morphometric data were obtained from digitized images of the segments at no-load and zero-stress states. Pressure and diameter changes were measured during flow and ramp distensions under active and passive experimental conditions. Circumferential stresses (force per area) and strains (deformation) were computed with referenced to the zero-stress state. The contraction frequency was analyzed. Contraction thresholds and maximum contraction amplitude were calculated in terms of mechanical stress and strain. Compared with controls, the IBS rats had lower body weight (P < 0.01), smaller colonic opening angle (P < 0.05), higher colonic contraction frequency (P < 0.05 and P < 0.01) and lower contraction thresholds of pressure, stress and strain in both ileum and colon (P < 0.05 and P < 0.01). The maximum contraction pressure, stress and strain did not differ between IBS and Control groups (P > 0.05). In conclusion, the pressure, stress, and strain to evoke contractility in ileum and colon were lower whereas the frequency of induced colon contractions was higher in NMD IBS rats compared to normal rats. Furthermore, zero-stress state remodeling occur in colon in NMD IBS rats. Further studies on the association between intestinal biomechanical properties, hypersensitivity and afferent signaling in the IBS animal models are warranted.

Comparison of Single‐bout AIH Protocols That Differ in Timing and Number of Hypoxic Episodes on Improvement in LUT Function in Adult Rats with SCI

Exposure to acute intermittent hypoxia (AIH) has been reported to improve respiratory and non‐respiratory somatic motor function in rodents and humans, and as such has been proposed as a potential therapeutic intervention for treatment of motor incomplete spinal cord injury (SCI). In our previous studies in rats with moderate mid‐thoracic (T8) SCI, we observed that a single bout of AIH produces sustained improvements in lower urinary tract (LUT) function characterized by decreased non‐voiding bladder contractions and increased void volume. In the present study, we extend these observations on lower LUT function in SCI rats by comparing the potential therapeutic benefits of different single‐bout AIH protocols that keep the total duration of hypoxia (15 min; 12% O2) constant but differ in timing and number of hypoxic episodes. To this end, four weeks after moderate contusion (200 kilodynes) mid‐thoracic SCI, bladder intravesical pressure was recorded in urethane‐anesthetized (1.4 g/kg), spontaneously breathing, vagally intact adult female Sprague‐Dawley rats (n = 44) during continuous infusion of saline (0.04 ml/min) into the bladder to elicit reflex micturition events. Following &gt;60 min of baseline recording, rats were exposed to a single bout of AIH consisting of (1) three 5‐min episodes of hypoxia each separated by 5‐min exposures to room air, (2) five 3‐min episodes of hypoxia each separated by 3‐min exposures to room air, or (3) ten 1.5‐min episodes of hypoxia each separated by 1.5‐min exposures to room air. Following completion of the AIH exposure protocol, data acquisition continued for up to 120 minutes while the rats continued to breathe room air, and these data were quantified based on features measured in 30‐min bins (post‐AIH data normalized to pre‐AIH data). These analyses revealed that each of the single‐bout AIH protocols elicited long‐lasting improvements (up to 120 min post‐AIH) in LUT function. Moreover, each of the protocols appeared to be equally effective in reducing the ratio of non‐voiding/voiding bladder contractions and increasing bladder inter‐contraction interval and micturition volume. Single‐bout AIH exposure also produced transient increases in both bladder contraction threshold pressure and minimum bladder pressure. Modulation of LUT behavior during individual exposures to hypoxia and immediately following each hypoxic episode (“off effect”) were also observed, with the intensity of the “off effect” tending to be lower following short duration (e.g., 10 × 1.5‐min) hypoxic exposures. Our observations suggest that each single‐bout AIH protocol is effective in reducing non‐voiding bladder contractions and increasing micturition in SCI rats albeit subtle differences in magnitude and/or timing were noted across the protocols. These data also provide additional evidence that single‐bout AIH exposure reduces bladder overactivity and stabilizes bladder function to improve voiding efficiency in SCI rats.Support or Funding InformationDOD CDMRP W81XWH‐17‐1‐0260; NYS DOH SCIRB C32088GGThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Stress-strain analysis of duodenal contractility in response to flow and ramp distension in rabbits fed low-fiber diet.

Previously we demonstrated that low-fiber diet in rabbits affects the passive mechanomorphological properties in the small intestine, resulting in reduced intestinal wall thickness and collagen content, as well as intestinal wall softening. The aim of the present study was to evaluate the contractility in rabbits on long-term low-fiber diet and specifically to compare the contraction threshold, the frequency, and the amplitude of flow-induced and distension-induced contractions in the duodenum between rabbits on normal diet and on long-term low-fiber diet. Ten rabbits were fed a low-fiber diet for 5months (Intervention group), and five rabbits were fed normal diet (Control group). The duodenal segments were used for determination of mechanical parameters for analyses of contractility. The duodenal experiments were carried out in organ baths containing physiological Krebs solution. Pressure and diameter changes induced by contractions in response to flow and ramp distension were measured. The frequencies and amplitude of contractions were analyzed. Distension-induced contraction thresholds and maximum contraction amplitude of flow-induced contractions were calculated in terms of mechanical stress and strain. Multiple linear regression analyses were applied to study dependencies between contractility parameters and wall thickness, wall area, and muscle layer thickness. During distension, the pressure, stress, and strain thresholds for induction of phasic contraction were biggest in the Intervention Group (P<0.05). In addition, the contraction frequencies during flow-induced contraction were highest in the Intervention Group (P<0.05), whereas the maximum contraction amplitudes in terms of pressure, diameter, stress, and strain were lowest in the Intervention Group (P<0.05). The contraction thresholds and contraction frequencies were negatively associated with the wall thickness, wall area, and muscle layer thickness, whereas maximum contraction amplitudes were positively associated with the wall thickness, wall area, and muscle layer thickness. Duodenal contractility in rabbits fed with long-term low-fiber diet exhibited low contraction amplitudes and high contraction thresholds and frequencies. The changes were associated with the low-fiber diet-induced histomorphological remodeling. Studies on detailed structural and functional diet-induced changes in smooth muscle and intestinal nerves are needed for better understanding the remodeling mechanisms.

135 A Novel Therapy for Premature Ejaculation: Transcutaneous Functional Electrical Stimulation-results of a Pioneer Study

To evaluate the safety and efficacy of Transcutaneous functional electrical stimulation (TFES) for the treatment of Premature Ejaculation (PE). Our preliminary safety study (n=19) demonstrated that applying TFES to the perineal region is safe. In the present study, we included 23 men aged 20-60 that complained of PE. On the first visit of this prospective, single-blinded, self-controlled study, we alternately delivered either TFES or sham treatment to the perineum, based on the enrollment order. For stimulation, we used a commercial neuro-muscular electrical stimulation device. The alternating second treatment was given to the same subject after a minimal period of one week. In order to determine the intensity threshold for muscle contraction, we gradually increased TFES intensity. Patients were instructed to inform the investigator upon first sensation of a convenient muscle contraction in the stimulated area, after which we applied this individual intensity-threshold during the study. The patients were left alone in a silent room to masturbate and, using a stopwatch, to measure their Masturbation Ejaculatory Latency Time (MELT), measured between full erection and ejaculation. Patients filled-out safety questionnaires after each visit and on each of the three following days.

Effect of Qianjinjiu on the Contraction of Gastrocnemius muscle of Isolated Sciatic Nerve

Objective: To investigate the water extract from Radix (Flemingia philippinensis Merr et Rolfe Decoction.) Effect of sciatic nerve gastrocnemius muscle Characteristics of isolated frog. Methods: The dissected lesion of sciatic nerve gastrocnemius muscle was infused with 0.9% saline, 0.125g / mL, 0.25g / mL, 0.5g / mL jelly extract, and the RM6240 bio-signal collector was used to measure each The infiltration depth of 5 minutes, infiltration for 10 minutes, infiltration of 15 minutes at each time point of the gastrocnemius muscle contraction threshold strength (measured at each time point 5 times) and complete single contraction curve (measured at each time point 25) Systolic rate, systolic rate, rate of contraction, and latency. Results: The systolic threshold intensity of the gastrocnemius muscle increased with the increase of the concentration of the extraction fluid, but less than the pre-treatment level (P &lt;0.01, P &lt;0.05). If the concentration and time (P &lt;0.05). At the same time, the systolic amplitude, systolic rate and diastolic rate increased first and then decreased with the increase of the concentration of the extract (P &lt;0.01, P &lt;0.05). The latency of the sciatic nerve of the sciatic nerve was affected by the concentration of the drug in the infiltration solution, which decreased first and then increased with the increase of the drug concentration. Conclusion: The systolic characteristics of skeletal muscle are affected by the weight of the components. Low concentration of salt water extract in a short time to improve the ability of skeletal muscle contraction, treatment time is too long or too high concentration of crude drugs will make the skeletal muscle contractility weakened, and even inhibit the skeletal muscle contractility, and affect the nerve Muscle excitement signal transmission.

Angiotensin II, a unique vasoactive agent dissociates myosin light chain phosphorylation from contraction.

Angiotensin II (100 nM) induced bi-phasic increases in cytosolic Ca2+ level ([Ca2+]i) through the activation of angiotensin II type 1 receptor. Pharmacological examinations using 10 µM verapamil, 30 µM La3+, and 1 µM thapsigargin indicated that the first phase of the [Ca2+]i-increase was mediated by Ca2+ release from sarcoplasmic reticulum (SR) and Ca2+ influx independently of voltage dependent Ca2+ channel (VDC). In contrast, the second phase of [Ca2+]i-increase was mediated by Ca2+ influx through VDC. Although both [Ca2+]i and myosin light chain (MLC)-phosphorylation at the first phase was apparently exceeded the threshold for contraction as estimated by high K+-induced responses, there was no appreciable contraction, indicating the dissociation between MLC phosphorylation and force during this phase. In contrast, the second phase of [Ca2+]i was associated with the increases in both MLC phosphorylation and force. These results suggest that angiotensin II is a unique agonist which dissociates MLC-phosphorylation from muscle force during the Ca2+ releases from SR.

Global genotype flow in Cercospora beticola populations confirmed through genotyping-by-sequencing.

Genotyping-by-sequencing (GBS) was conducted on 333 Cercospora isolates collected from Beta vulgaris (sugar beet, table beet and swiss chard) in the USA and Europe. Cercospora beticola was confirmed as the species predominantly isolated from leaves with Cercospora leaf spot (CLS) symptoms. However, C. cf. flagellaris also was detected at a frequency of 3% in two table beet fields in New York. Resolution of the spatial structure and identification of clonal lineages in C. beticola populations using genome-wide single nucleotide polymorphisms (SNPs) obtained from GBS was compared to genotyping using microsatellites. Varying distance thresholds (bitwise distance = 0, 1.854599 × 10−4, and 1.298 × 10−3) were used for delineation of clonal lineages in C. beticola populations. Results supported previous reports of long distance dispersal of C. beticola through genotype flow. The GBS-SNP data set provided higher resolution in discriminating clonal lineages; however, genotype identification was impacted by filtering parameters and the distance threshold at which the multi-locus genotypes (MLGs) were contracted to multi-locus lineages. The type of marker or different filtering strategies did not impact estimates of population differentiation and structure. Results emphasize the importance of robust filtering strategies and designation of distance thresholds for delineating clonal lineages in population genomics analyses that depend on individual assignment and identification of clonal lineages. Detection of recurrent clonal lineages shared between the USA and Europe, even in the relaxed-filtered SNP data set and with a conservative distance threshold for contraction of MLGs, provided strong evidence for global genotype flow in C. beticola populations. The implications of intercontinental migration in C. beticola populations for CLS management are discussed.

Localization of Deep Brain Stimulation Contacts Using Corticospinal/Corticobulbar Tracts Stimulation.

Successful deep brain stimulation (DBS) in Parkinson's disease (PD) requires optimal electrode placement. One technique of intraoperative electrode testing is determination of stimulation thresholds inducing corticospinal/corticobulbar tracts (CSBT) motor contractions. This study aims to analyze correlations between DBS electrode distance to CSBT and contraction thresholds, with either visual or electromyography (EMG) detection, to establish an intraoperative tool devoted to ensure safe distance of the electrode to the CSBT. Twelve PD patients with subthalamic nucleus DBS participated. Thresholds of muscular contractions were assessed clinically and with EMG, for three different sets of stimulation parameters, all monopolar: 130 Hz high-frequency stimulation (HFS); 2 Hz low-frequency stimulation with either 60 or 210 µs (LFS-60, LFS-210). The anatomical distance of electrode contacts to CSBT was measured from fused CT-MRI. The best linear correlation was found for thresholds of visually detected contractions with HFS (r2 = 0.63, p < 0.0001) when estimated stimulation currents rather than voltages were used. This correlation was found in agreement with an accepted model of electrical spatial extent of activation (r2 = 0.50). When using LFS, the correlation found remained lower than for HFS but increased when EMG was used. Indeed, the detection of contraction thresholds with EMG versus visual inspection did allow more frequent detection of face contractions, contributing to improve that correlation. The correlation between electrode distance to the CSBT and contraction thresholds was found better when estimated with currents rather than voltage, eliminating the variance due to electrode impedance. Using LFS did not improve the precision of that evaluation, but EMG did. This technique provides a prediction band to ensure minimum distance of the electrode contacts to the CSBT, integrating the variance that can be encountered between prediction of models and practice.

Presence and Absence of Muscle Contraction Elicited by Peripheral Nerve Electrical Stimulation Differentially Modulate Primary Motor Cortex Excitability.

Modulation of cortical excitability by sensory inputs is a critical component of sensorimotor integration. Sensory afferents, including muscle and joint afferents, to somatosensory cortex (S1) modulate primary motor cortex (M1) excitability, but the effects of muscle and joint afferents specifically activated by muscle contraction are unknown. We compared motor evoked potentials (MEPs) following median nerve stimulation (MNS) above and below the contraction threshold based on the persistence of M-waves. Peripheral nerve electrical stimulation (PES) conditions, including right MNS at the wrist at 110% motor threshold (MT; 110% MNS condition), right MNS at the index finger (sensory digit nerve stimulation [DNS]) with stimulus intensity approximately 110% MNS (DNS condition), and right MNS at the wrist at 90% MT (90% MNS condition) were applied. PES was administered in a 4 s ON and 6 s OFF cycle for 20 min at 30 Hz. In Experiment 1 (n = 15), MEPs were recorded from the right abductor pollicis brevis (APB) before (baseline) and after PES. In Experiment 2 (n = 15), M- and F-waves were recorded from the right APB. Stimulation at 110% MNS at the wrist evoking muscle contraction increased MEP amplitudes after PES compared with those at baseline, whereas DNS at the index finger and 90% MNS at the wrist not evoking muscle contraction decreased MEP amplitudes after PES. M- and F-waves, which reflect spinal cord or muscular and neuromuscular junctions, did not change following PES. These results suggest that muscle contraction and concomitant muscle/joint afferent inputs specifically enhance M1 excitability.