scholarly journals Oculomotor adaptation to prisms is not simply a muscle potentiation effect

1975 ◽  
Vol 18 (2) ◽  
pp. 105-106 ◽  
Author(s):  
Brian Craske ◽  
Martin Crawshaw
Keyword(s):  
Potentiation Effect ◽  
Muscle Potentiation ◽  
Oculomotor Adaptation

Adaptation to tilt is not produced by eye-muscle potentiation

1990 ◽  
Vol 30 (5) ◽  
pp. 779-783 ◽  
Author(s):  
H.H. Mikaelian ◽  
D.M. Mikaelian ◽  
E.L. Cameron
Keyword(s):  
Eye Muscle ◽  
Muscle Potentiation

The Threshold for Potassium-Induced Contractures of Frog Skeletal Muscle. Potentiation of Potassium-Induced Contractures by Preexposure to Subthreshold Potassium Concentrations

1972 ◽  
Vol 50 (1) ◽  
pp. 37-44 ◽  
Author(s):  
E. C. Vos ◽  
G. B. Frank
Keyword(s):  
Skeletal Muscle ◽  
Potassium Concentration ◽  
Ringer Solution ◽  
Frog Skeletal Muscle ◽  
Contractile Apparatus ◽  
Tension Development ◽  
Eventual Loss ◽  
Active Processes ◽  
Muscle Potentiation ◽  
Small Bundle

A brief exposure (about 10–30 s) of a frog's toe muscle or a small bundle of fibers from the semi-tendinosus muscle to just subthreshold potassium concentrations potentiated contractures subsequently produced by exposing the muscles to a potassium concentration slightly above the threshold. The contractures thus potentiated had greater maximum tensions, and greater rates of tension development and relaxation than control contractures elicited by the same final potassium concentration. The resistance to stretch (R.T.S.) in the first few seconds of the potentiated contractures was about twice that of control contractures. Maximum potentiation occurred with preexposures of about 30 s; longer preexposures led to a decrease of potentiation and eventually to a depression of the contracture. The potentiation was not immediately abolished when the muscle was reexposed to Ringer solution but persisted for 2 min or longer (the 'washout effect'). It was concluded that exposing a muscle to low subcontracture threshold concentrations of potassium for a few seconds primes the intracellular contractile apparatus, probably by causing an increased sarcoplasmic concentration of Ca2+ ions, resulting in a potentiation of subsequently induced submaximal potassium contractures. The increase in metabolism (or 'Solandt effect') seen under these conditions is temporally related to the decline and eventual loss of the potentiation and is probably a reflection of active processes involved in reducing the sarcoplasmic concentration of Ca2+ ions.

scholarly journals Potentiation effect of choline esters on choline-catalysed decarbamoylation of dimethylcarbamoyl-acetylcholinesterase

1992 ◽  
Vol 284 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Y B Kim ◽  
C H Jung ◽  
S J Choi ◽  
W J Seo ◽  
S H Cha ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Quaternary Ammonium ◽  
Acyl Chain ◽  
Requirement Analysis ◽  
Ester Bond ◽  
Choline Ester ◽  
Anionic Sites ◽  
Structural Requirement ◽  
Potentiation Effect ◽  
Choline Esters

The choline esters potentiated the choline-catalysed decarbamoylation of dimethylcarbamoyl-acetylcholinesterase in proportion to the length of acyl group, although esters containing an acyl chain longer than the hexanoyl group exhibited a corresponding decrease in the potentiation. In structural requirement analysis it was found that both the quaternary ammonium moiety and the ester bond were important for the effective acceleration of choline-catalysed decarbamoylation. In general, the respective thiocholine ester was found to be more effective than the corresponding choline ester. Whereas the binding affinity (Ka) of choline in the decarbamoylation was not significantly altered, the maximum decarbamoylation rate (kr(max.)) of choline was greatly enhanced in the presence of choline esters or thiocholine esters. Along with the above observation, the isotope solvent effect, the effect of ionic strength and the antagonism studies demonstrate that the choline esters or thiocholine esters may interact with one of peripheral anionic sites, and thereby make the choline-catalysed decarbamoylation more favourable.

scholarly journals An Antipersister Strategy for Treatment of Chronic Pseudomonas aeruginosa Infections

2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Martina Koeva ◽  
Alina D. Gutu ◽  
Wesley Hebert ◽  
Jeffrey D. Wager ◽  
Lael M. Yonker ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lactate Dehydrogenase ◽  
Stationary Phase ◽  
Persister Cells ◽  
Content Type ◽  
Ph Values ◽  
Potentiation Effect ◽  
Metabolite Concentrations ◽  
Ldh Assay

ABSTRACTBacterial persisters are a quasidormant subpopulation of cells that are tolerant to antibiotic treatment. The combination of the aminoglycoside tobramycin with fumarate as an antibacterial potentiator utilizes an antipersister strategy that is aimed at reducing recurrentPseudomonas aeruginosainfections by enhancing the killing ofP. aeruginosapersisters. Stationary-phase cultures ofP. aeruginosawere used to generate persister cells. A range of tobramycin concentrations was tested with a range of metabolite concentrations to determine the potentiation effect of the metabolite under a variety of conditions, including a range of pH values and in the presence of azithromycin or cystic fibrosis (CF) patient sputum. In addition, 96-well dish biofilm and colony biofilm assays were performed, and the cytotoxicity of the tobramycin-fumarate combination was determined utilizing a lactate dehydrogenase (LDH) assay. Enhanced killing of up to 6 orders of magnitude ofP. aeruginosapersisters over a range of CF isolates, including mucoid and nonmucoid strains, was observed for the tobramycin-fumarate combination compared to killing with tobramycin alone. Furthermore, significant fumarate-mediated potentiation was seen in the presence of azithromycin or CF patient sputum. Fumarate also reduced the cytotoxicity of tobramycin-treatedP. aeruginosato human epithelial airway cells. Finally, in mucoid and nonmucoid CF isolates, complete eradication ofP. aeruginosabiofilm was observed in the colony biofilm assay due to fumarate potentiation. These data suggest that a combination of tobramycin with fumarate as an antibacterial potentiator may be an attractive therapeutic for eliminating recurrentP. aeruginosainfections in CF patients through the eradication of bacterial persisters.

Postactivation potentiation effect of two lower body resistance exercises on repeated jump performance measures

2020 ◽  
Vol 37 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Daniel Gahreman ◽  
Mehdi Moghadam ◽  
Ehsan Hoseininejad ◽  
Vahid Dehnou ◽  
Jonathan Connor ◽  
...  
Keyword(s):  
Performance Measures ◽  
Lower Body ◽  
Postactivation Potentiation ◽  
Jump Performance ◽  
Potentiation Effect ◽  
Resistance Exercises ◽  
Body Resistance

scholarly journals Effects of Acupuncture on Explosive Force Production by the Healthy Female Shoulder Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
I-Lin Wang ◽  
Yi-Ming Chen ◽  
Jun Wang ◽  
Rui Hu ◽  
Ke-Ke Zhang ◽  
...  
Keyword(s):  
Shoulder Joint ◽  
Force Production ◽  
Maximum Speed ◽  
Maximum Torque ◽  
Shoulder Muscles ◽  
Potentiation Effect ◽  
Average Maximum ◽  
Significant Difference ◽  
Before And After ◽  
Explosive Force

Background. Acupuncture is often used to treat chronic conditions, such as pain. In recent years, given the importance of the explosive forces generated by shoulder muscles for the completion of motor tasks, studies in which nerves were stimulated through acupuncture to increase the explosive forces were conducted. This study explored the effect of acupuncture on explosive force production by the muscles of the female shoulder joint. Methods. Eighteen healthy women underwent shoulder adduction (Add), abduction (Abd), flexion (Flex), and extension (Ext) tests with an isokinetic measurement system. Acupuncture was used to stimulate the Zhongfu (LU1), Tianfu (LI3), Xiabai (LU4), Binao (LI14), Naohui (SJ13), Jianliao (SJ14), and Xiaoluo (SJ12) points, and electromyography (EMG) signals were recorded before and after acupuncture. Results. After acupuncture, there was a significant difference in the average maximum work, the average maximum power, the average maximum speed, the total work in Add/Abd and Flex/Ext, the EMG signals, and the stiffness of the muscles in Abd and Ext ( P < 0.05 ). There were no significant differences in the average maximum torque in Abd or Flex. Conclusion. Based on the results, there may be a significant correlation between the manipulation of different acupoints by acupuncture and the average maximum torque and stiffness. Acupuncture may stimulate nerves to activate muscles and induce a postactivation potentiation effect that improves explosive force production. Therefore, acupuncture as an auxiliary tool may increase the explosive forces generated by acupoint-related muscles by stimulating nerves.

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