Motility studies of isolated antral pouches before and after vagus denervation

1959 ◽  
Vol 14 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Donald E. Wohlrabe ◽  
William D. Kelly
Keyword(s):  
Electrical Stimulation ◽  
Reliable Method ◽  
Time Interval ◽  
Vagus Nerves ◽  
Parasympathetic Innervation ◽  
Insulin Hypoglycemia ◽  
Difference Of Opinion ◽  
Before And After ◽  
Vagal Innervation ◽  
Greater Curvature

The motility responses of vagus innervated and denervated antral pouches to electrical stimulation of the vagus nerves and to insulin hypoglycemia were determined. Electrical stimulation appears to be a reliable method of demonstrating the presence or absence of vagus nerve supply to the antrum both in acute studies and in preparations of several months' duration. The motility response of the antral pouch to insulin hypoglycemia was found to be a less reliable method of determining the presence or absence of vagal innervation largely because spontaneous hypermotility may occur and there is more room for difference of opinion in interpretation of the results obtained. The administration of glucose after an appropriate time interval, however, added significantly to the reliability of the test. By the methods employed the antral branches of the vagus nerves were found to be the only sources of vagus innervation of the antrum. No evidence was obtained to suggest effective parasympathetic innervation of the antrum via a pyloric nerve, via the greater curvature mesenteric attachment or via an intramural gastric pathway. Submitted on July 7, 1958

scholarly journals Effect of Electrical Stimulation of the Vagus Nerves on Bile Secretion in Anaesthetized Sheep

1976 ◽  
Vol 29 (4) ◽  
pp. 351 ◽  
Author(s):  
MichaeI Pass ◽  
Trevor Heath
Keyword(s):  
Electrical Stimulation ◽  
Bile Salt ◽  
Maximum Rate ◽  
Vagal Stimulation ◽  
Bile Secretion ◽  
Vagus Nerves ◽  
Bile Formation ◽  
Vagal Innervation ◽  
Bicarbonate Output ◽  
Stimulation Of

Bile was collected before and during electrical stimulation of the vagus nerves in acute experiments on sheep with ligated cystic ducts. Most stimuli caused no change in: bile formation, but a 10-V, 10-Hz stimulus caused a slight increase in bicarbonate output. Neither the response to infused secretin nor the maximum rate of bile salt transpoit by liver cells changed during vagal stimulation; It was concluded that the vagal innervation of the liver is not likely to playa major role in the regulation of bile formation in sheep.

scholarly journals Insights into the combination of neuromuscular electrical stimulation and motor imagery in a training-based approach

2021 ◽  
Author(s):  
Amandine Bouguetoch ◽  
Alain Martin ◽  
Sidney Grosprêtre
Keyword(s):  
Electrical Stimulation ◽  
Motor Imagery ◽  
Neural Plasticity ◽  
Neuromuscular Electrical Stimulation ◽  
Voluntary Contraction ◽  
Muscle Architecture ◽  
Fascicle Length ◽  
Before And After ◽  
V Wave ◽  
And Control

Abstract Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.

Temporal dynamics of encrusting communities during the Late Devonian: a case study from the Central Devonian Field, Russia

Paleobiology ◽  
2017 ◽  
Vol 43 (4) ◽  
pp. 550-568 ◽  
Author(s):  
Michał Zatoń ◽  
Tomasz Borszcz ◽  
Michał Rakociński
Keyword(s):  
Temporal Dynamics ◽  
Small Sample ◽  
Time Interval ◽  
Faunal Turnover ◽  
Central Devonian Field ◽  
Before And After ◽  
Substrate Size ◽  
Mass Extinction Event ◽  
Diversity Dynamics

AbstractIn this study we focused on the dynamics of encrusting assemblages preserved on brachiopod hosts collected from upper Frasnian and lower Famennian deposits of the Central Devonian Field, Russia. Because the encrusted brachiopods come from deposits bracketing the Frasnian/Famennian (F/F) boundary, the results also shed some light on ecological differences in encrusting communities before and after the Frasnian–Famennian (F-F) event. To explore the diversity dynamics of encrusting assemblages, we analyzed more than 1300 brachiopod valves (substrates) from two localities. Taxon accumulation plots and shareholder quorum subsampling (SQS) routines indicated that a reasonably small sample of brachiopod host valves (n=50) is sufficient to capture the majority of the encrusting genera recorded at a given site. The richness of encrusters per substrate declined simultaneously with the number of encrusting taxa in the lower Famennian, accompanied by a decrease in epibiont abundance, with a comparable decrease in mean encrustation intensity (percentage of bioclasts encrusted by one or more epibionts). Epibiont abundance and occupancy roughly mirror each other. Strikingly, few ecological characteristics are correlated with substrate size, possibly reflecting random settlement of larvae. Evenness, which is negatively correlated with substrate size, shows greater within-stage variability among samples than between Frasnian and Famennian intervals and may indicate the instability of early Famennian biocenoses following the faunal turnover. The occurrence distribution of encrusters points to nonrandom associations and exclusions among several encrusting taxa. However, abundance and occupancy of microconchids remained relatively stable throughout the sampled time interval. The notable decline in abundance (~60%) and relatively minor decline in diversity (~30%) suggest jointly that encrusting communities experienced ecological collapse rather than a major mass extinction event. The differences between the upper Frasnian and lower Famennian encrusting assemblages may thus record a turnover associated with the F-F event.

scholarly journals Investigation of different stimulation patterns with doublet pulses to reduce muscle fatigue

2019 ◽  
Vol 6 ◽  
pp. 205566831982580 ◽  
Author(s):  
Ruslinda Ruslee ◽  
Jennifer Miller ◽  
Henrik Gollee
Keyword(s):  
Electrical Stimulation ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Muscle Activation ◽  
Motor Units ◽  
Pulse Interval ◽  
Time Interval ◽  
Fatigue Index ◽  
Significant Difference ◽  
Cord Injury

Introduction: Functional electrical stimulation is a common technique used in the rehabilitation of individuals with a spinal cord injury to produce functional movement of paralysed muscles. However, it is often associated with rapid muscle fatigue which limits its applications. Methods: The objective of this study is to investigate the effects on the onset of fatigue of different multi-electrode patterns of stimulation via multiple pairs of electrodes using doublet pulses: Synchronous stimulation is compared to asynchronous stimulation patterns which are activated sequentially (AsynS) or randomly (AsynR), mimicking voluntary muscle activation by targeting different motor units. We investigated these three different approaches by applying stimulation to the gastrocnemius muscle repeatedly for 10 min (300 ms stimulation followed by 700 ms of no-stimulation) with 40 Hz effective frequency for all protocols and doublet pulses with an inter-pulse-interval of 6 ms. Eleven able-bodied volunteers (28 ± 3 years old) participated in this study. Ultrasound videos were recorded during stimulation to allow evaluation of changes in muscle morphology. The main fatigue indicators we focused on were the normalised fatigue index, fatigue time interval and pre-post twitch–tetanus ratio. Results: The results demonstrate that asynchronous stimulation with doublet pulses gives a higher normalised fatigue index (0.80 ± 0.08 and 0.87 ± 0.08) for AsynS and AsynR, respectively, than synchronous stimulation (0.62 ± 0.06). Furthermore, a longer fatigue time interval for AsynS (302.2 ± 230.9 s) and AsynR (384.4 ± 279.0 s) compared to synchronous stimulation (68.0 ± 30.5 s) indicates that fatigue occurs later during asynchronous stimulation; however, this was only found to be statistically significant for one of two methods used to calculate the group mean. Although no significant difference was found in pre-post twitch–tetanus ratio, there was a trend towards these effects. Conclusion: In this study, we proposed an asynchronous stimulation pattern for the application of functional electrical stimulation and investigated its suitability for reducing muscle fatigue compared to previous methods. The results show that asynchronous multi-electrode stimulation patterns with doublet pulses may improve fatigue resistance in functional electrical stimulation applications in some conditions.

Efferent vagal innervation of canine ventricle

1985 ◽  
Vol 248 (1) ◽  
pp. H89-H97 ◽  
Author(s):  
N. Takahashi ◽  
M. J. Barber ◽  
D. P. Zipes
Keyword(s):  
Coronary Artery ◽  
Vagal Stimulation ◽  
Left Ventricular ◽  
Constant Infusion ◽  
Epicardial Surface ◽  
Before And After ◽  
Vagal Innervation ◽  
The Subject ◽  
Infusion Of Norepinephrine ◽  
The Right

The route efferent vagal fibers travel to reach the left ventricle is not clear and was the subject of this investigation. We measured left ventricular and septal effective refractory period (ERP) changes during vagal stimulation and a constant infusion of norepinephrine, before and after phenol was applied at selected sites of the heart to interrupt efferent vagal fibers that may be traveling in that area. Phenol applied to the atrioventricular (AV) groove between the origin of the right coronary artery anteriorly to the posterior descending branch of the circumflex coronary artery completely eliminated vagal-induced prolongation of ERP in the anterior and posterior left ventricular free wall and reduced, but did not eliminate, ERP prolongation in the septum. A large (3-cm radius) epicardial circle of phenol prevented vagal-induced ERP prolongation within the circle in all dogs, while a small (1-cm radius) epicardial circle of phenol failed to prevent vagal-induced ERP changes within the circle in any dog. An intermediate (2-cm radius) circle eliminated vagal effects on ERP in 13 of 18 dogs. Arcs of phenol, to duplicate the upper portion of the circle, applied sequentially from apex to base eliminated efferent vagal effects only when painted near or at the AV groove. We conclude that the majority of efferent vagal fibers enroute to innervate the anterior and posterior left ventricular epicardium cross the AV groove within 0.25-0.5 mm (depth of phenol destruction) of the epicardial surface.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Evaluation of color stability of different temporary restorative materials

2015 ◽  
Vol 44 (5) ◽  
pp. 262-267 ◽  
Author(s):  
José Vitor Quinelli Mazaro ◽  
Luiz Miguel Minani ◽  
Adriana Cristina Zavanelli ◽  
Caroline Cantieri de Mello ◽  
Cleidiel Aparecido Araújo Lemos
Keyword(s):  
Storage Time ◽  
Color Change ◽  
Artificial Saliva ◽  
Color Stability ◽  
Time Interval ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Restorative Materials ◽  
Before And After ◽  
Level Of Significance

AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001).ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

Cross-talk along gastrointestinal tract during electrical stimulation: effects and mechanisms of gastric/colonic stimulation on rectal tone in dogs

2005 ◽  
Vol 288 (6) ◽  
pp. G1195-G1198 ◽  
Author(s):  
Shi Liu ◽  
Lijie Wang ◽  
J. D. Z. Chen
Keyword(s):  
Electrical Stimulation ◽  
Inhibitory Effect ◽  
Adrenergic Blockade ◽  
Rectal Compliance ◽  
Rectal Tone ◽  
Before And After ◽  
Sensory Functions ◽  
Sympathetic Pathway ◽  
Colonic Electrical Stimulation ◽  
Stimulation Of

Gastric electrical stimulation (GES) has been shown to alter motor and sensory functions of the stomach. However, its effects on other organs of the gut have rarely been investigated. The study was performed in 12 dogs implanted with two pairs of electrodes, one on the serosa of the stomach and the other on the colon. The study was composed of two experiments. Experiment 1 was designed to study the effects of GES on rectal tone and compliance in nine dogs compared with colonic electrical stimulation (CES). Rectal tone and compliance were assessed before and after GES or CES. Experiment 2 was performed to study the involvement of sympathetic pathway in 8 of the 12 dogs. The rectal tone was recorded for 30–40 min at baseline and 20 min after intravenous guanethidine. GES or CES was given for 20 min 20 min after the initiation of the infusion. It was found that both GES and CES reduced rectal tone with comparable potency. Rectal compliance was altered neither with GES, nor with CES. The inhibitory effect of GES but not CES on rectal tone was abolished by an adrenergic blockade, guanethidine. GES inhibited rectal tone with a comparable potency with CES but did not alter rectal compliance. The inhibitory effect of GES on rectal tone is mediated by the sympathetic pathway. It should be noted that electrical stimulation of one organ of the gut may have a beneficial or adverse effect on another organ of the gut.

Deterioration of Local Mechanical Properties of HVOF-Sprayed Stellite 6 after Exposure to High-Temperature Corrosion

2015 ◽  
Vol 662 ◽  
pp. 115-118 ◽  
Author(s):  
Zdeněk Česánek ◽  
Jan Schubert ◽  
Šárka Houdková ◽  
Olga Bláhová ◽  
Michaela Prantnerová
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperature Corrosion ◽  
Corrosion Testing ◽  
Time Interval ◽  
Coating Properties ◽  
Operational Conditions ◽  
Stellite 6 ◽  
Coating Surface ◽  
Before And After

Coating properties determine its behavior in operation. The simulation of future operational conditions is therefore the best quality test. The evaluation during operation is usually not possible to perform, and the coatings are therefore frequently characterized by their physical or mechanical properties. This text deals with the high temperature corrosion of HVOF sprayed Stellite 6 coating and with changes of its local mechanical properties before and after the corrosion testing. High temperature corrosion is defined as a corrosion in the presence of molten salts. In this case, the mixture of salts in composition of 59% Na2(SO)4 with 34.5% KCl and 6.5% NaCl was used. Two exposure temperatures 525 °C and 575 °C were selected and the tests for both temperatures were performed in the time interval of 168h in the autoclave. The coating with salt mixture layer was analyzed using scanning electron microscopy and nanoindentation. The high temperature resistance of Stellite 6 coating was evaluated according to the changes in the coating surface and by the occurrence of individual phases formed on the coating surface during the test. Generally, it can be said that the Stellite 6 alloys deposited by HVOF technology show selective oxidation under the salt film. This fact was also proved in this study. Furthermore, the nanoindentation measurements of Stellite 6 coating were performed before and after the corrosion testing. These measurements were used to evaluate the change of local mechanical coating properties.

Lumbar Puncture in Pediatric Bacterial Meningitis: Defining the Time Interval for Recovery of Cerebrospinal Fluid Pathogens After Parenteral Antibiotic Pretreatment

PEDIATRICS ◽  
2001 ◽  
Vol 108 (5) ◽  
pp. 1169-1174 ◽  
Author(s):  
John T. Kanegaye ◽  
Peyman Soliemanzadeh ◽  
John S. Bradley
Keyword(s):  
Cerebrospinal Fluid ◽  
Bacterial Meningitis ◽  
Laboratory Data ◽  
Final Diagnosis ◽  
Prolonged Treatment ◽  
Time Interval ◽  
Antibiotic Administration ◽  
Parenteral Antibiotic ◽  
Culture Material ◽  
Before And After

Objective. Despite the lack of evidence defining a time interval during which cerebrospinal fluid (CSF) culture yield will not be affected by previous antibiotic therapy, recent publications cite a “minimum window” of 2 to 3 hours for recovery of bacterial pathogens after parenteral antibiotic administration. We conducted a retrospective review of children with bacterial meningitis to describe the rate at which parenteral antibiotic pretreatment sterilizes CSF cultures. Methods. The medical records of pediatric patients who were discharged from a tertiary children's hospital during a 5-year period with the final diagnosis of bacterial meningitis or suspected bacterial meningitis were reviewed. The decay in yield of CSF cultures over time was evaluated in patients with lumbar punctures (LP) delayed until after initiation of parenteral antibiotics and in patients with serial LPs before and after initiation of parenteral antibiotics. Results. The pathogens that infected the 128 study patients were Streptococcus pneumoniae (49),Neisseria meningitidis (37), group BStreptococcus (21), Haemophilus influenzae (8), other organisms (11), and undetermined (3). Thirty-nine patients (30%) had first LPs after initiation of parenteral antibiotics, and 55 (43%) had serial LPs before and after initiation of parenteral antibiotics. After ≥50 mg/kg of a third-generation cephalosporin, 3 of 9 LPs in meningococcal meningitis were sterile within 1 hour, occurring as early as 15 minutes, and all were sterile by 2 hours. With pneumococcal disease, the first negative CSF culture occurred at 4.3 hours, with 5 of 7 cultures negative from 4 to 10 hours after initiation of parenteral antibiotics. Reduced susceptibility to β-lactam antibiotics occurred in 11 of 46 pneumococcal isolates. Group B streptococcal cultures were positive through the first 8 hours after parenteral antibiotics. Blood cultures were positive in 74% of cases without pretreatment and in 57% to 68% of cases with negative CSF cultures. Conclusions. The temptation to initiate antimicrobial therapy may override the principle of obtaining adequate pretreatment culture material. The present study demonstrates that CSF sterilization may occur more rapidly after initiation of parenteral antibiotics than previously suggested, with complete sterilization of meningococcus within 2 hours and the beginning of sterilization of pneumococcus by 4 hours into therapy. Lack of adequate culture material may result in inability to tailor therapy to antimicrobial susceptibility or in unnecessarily prolonged treatment if the clinical presentation and laboratory data cannot exclude the possibility of bacterial meningitis.

scholarly journals Blood Transfusion Practice before and after Implementation of Type and Screen Protocol in Emergency Department of a University Affiliated Hospital in Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Mostafa Alavi-Moghaddam ◽  
Mahmoud Bardeh ◽  
Hossein Alimohammadi ◽  
Habib Emami ◽  
Seyed-Mostafa Hosseini-Zijoud
Keyword(s):  
Emergency Department ◽  
Blood Transfusion ◽  
Transfusion Practice ◽  
Time Interval ◽  
Blood Transfusions ◽  
Common Diseases ◽  
Before And After ◽  
Transfusion Ratio ◽  
Cross Match

Background. Blood transfusion is the cornerstone of therapy for many serious and common diseases. This study was performed to assess blood transfusion practice before and after implementation of type and screen protocol in emergency department of a university affiliated hospital in Iran, 2012-2013.Methods. An audit was studied before and after the implementation of type and screen protocol. The number of blood transfusions, time interval between blood order and transfusion, cross-match to transfusion ratio (C/Tratio), and transfusion index (TI) were checked.C/Tratio was used as a measure of the efficiency of blood ordering practice. We compared our results before and after implementation of type and screen protocol.Results. In present study after implementation of type and screen protocol, the time interval between requesting blood transfusion and transfusion of blood has decreased significantly (P<0.001). The number of blood transfusions required by actual patients increased significantly from 1/2 to 2 (P<0.001). The average cross-match to transfusion (C/T) ratio got near 1.13 from 1.41 and TI got near 0.91 from 0.58 (P<0.001).Conclusion. The implementation of T&S protocol has been proven to be safe, efficient, and beneficial to the transfusion practice of our hospital from the current study.

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