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1

Altered neuromuscular control mechanisms of the trapezius muscle in fibromyalgia  

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Abstract Background fibromyalgia is a relatively common condition with widespread pain and pressure allodynia, but unknown aetiology. For decades, the association between motor control strategies and chronic pain has been a topic for debate. One long held functional neuromuscular control mechanism is differential activation between regions within a single muscle. The aim of this study was to investigate differences in neuromuscular control, i.e. differential activation, betwe...

Gerdle Björn; Grönlund Christer; Karlsson Stefan J; Holtermann Andreas; Roeleveld Karin

2010-01-01

2

Molecular control of neuromuscular junction development  

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Skeletal muscle innervation is a multi-step process leading to the neuromuscular junction (NMJ) apparatus formation. The transmission of the signal from nerve to muscle occurs at the NMJ level. The molecular mechanism that orchestrates the organization and functioning of synapses is highly complex, and it has not been completely elucidated so far. Neuromuscular junctions are assembled on the muscle fibers at very precise locations called end plates (EP). Acetylcholine receptor (AChR) clusteri...

Ferraro, Elisabetta; Molinari, Francesca; Berghella, Libera

2012-01-01

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Proprioceptive Neuromuscular Facilitation (PNF): Its Mechanisms and Effects on Range of Motion and Muscular Function  

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Proprioceptive neuromuscular facilitation (PNF) is common practice for increasing range of motion, though little research has been done to evaluate theories behind it. The purpose of this study was to review possible mechanisms, proposed theories, and physiological changes that occur due to proprioceptive neuromuscular facilitation techniques. Four theoretical mechanisms were identified: autogenic inhibition, reciprocal inhibition, stress relaxation, and the gate control theory. The studies s...

Hindle, Kayla B.; Whitcomb, Tyler J.; Briggs, Wyatt O.; Hong, Junggi

2012-01-01

4

Invasive home mechanical ventilation, mainly focused on neuromuscular disorders  

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Introduction and background: Invasive home mechanical ventilation is used for patients with chronic respiratory insufficiency. This elaborate and technology-dependent ventilation is carried out via an artificial airway (tracheal cannula) to the trachea. Exact numbers about the incidence of home mechanical ventilation are not available. Patients with neuromuscular diseases represent a large portion of it. Research questions: Specific research questions are formulated and answered concerning th...

2010-01-01

5

Invasive home mechanical ventilation, mainly focused on neuromuscular disorders  

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Introduction and background Invasive home mechanical ventilation is used for patients with chronic respiratory insufficiency. This elaborate and technology-dependent ventilation is carried out via an artificial airway (tracheal cannula) to the trachea. Exact numbers about the incidence of home mechanical ventilation are not available. Patients with neuromuscular diseases represent a large portion of it. Research questions Specific research questions are formulated and answered concerning the ...

Geiseler, J.; Karg, O.; Bo?rger, S.; Becker, K.; Zimolong, A.

2010-01-01

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Invasive home mechanical ventilation, mainly focused on neuromuscular disorders  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction and background: Invasive home mechanical ventilation is used for patients with chronic respiratory insufficiency. This elaborate and technology-dependent ventilation is carried out via an artificial airway (tracheal cannula to the trachea. Exact numbers about the incidence of home mechanical ventilation are not available. Patients with neuromuscular diseases represent a large portion of it. Research questions: Specific research questions are formulated and answered concerning the dimensions of medicine/nursing, economics, social, ethical and legal aspects. Beyond the technical aspect of the invasive home, mechanical ventilation, medical questions also deal with the patient’s symptoms and clinical signs as well as the frequency of complications. Economic questions pertain to the composition of costs and the differences to other ways of homecare concerning costs and quality of care. Questions regarding social aspects consider the health-related quality of life of patients and caregivers. Additionally, the ethical aspects connected to the decision of home mechanical ventilation are viewed. Finally, legal aspects of financing invasive home mechanical ventilation are discussed. Methods: Based on a systematic literature search in 2008 in a total of 31 relevant databases current literature is viewed and selected by means of fixed criteria. Randomized controlled studies, systematic reviews and HTA reports (health technology assessment, clinical studies with patient numbers above ten, health-economic evaluations, primary studies with particular cost analyses and quality-of-life studies related to the research questions are included in the analysis. Results and discussion: Invasive mechanical ventilation may improve symptoms of hypoventilation, as the analysis of the literature shows. An increase in life expectancy is likely, but for ethical reasons it is not confirmed by premium-quality studies. Complications (e. g. pneumonia are rare. Mobile home ventilators are available for the implementation of the ventilation. Their technical performance however, differs regrettably. Studies comparing the economic aspects of ventilation in a hospital to outpatient ventilation, describe home ventilation as a more cost-effective alternative to in-patient care in an intensive care unit, however, more expensive in comparison to a noninvasive (via mask ventilation. Higher expenses arise due to the necessary equipment and the high expenditure of time for the partial 24-hour care of the affected patients through highly qualified personnel. However, none of the studies applies to the German provisionary conditions. The calculated costs strongly depend on national medical fees and wages of caregivers, which barely allows a transmission of the results. The results of quality-of-life studies are mostly qualitative. The patient’s quality of life using mechanical ventilation is predominantly considered well. Caregivers of ventilated patients report positive as well as negative ratings. Regarding the ethical questions, it was researched which aspects of ventilation implementation will have to be considered. From a legal point of view the financing of home ventilation, especially invasive mechanical ventilation, requiring specialised technical nursing is regulated in the code of social law (Sozialgesetzbuch V. The absorption of costs is distributed to different insurance carriers, who often, due to cost pressures within the health care system, insurance carriers, who consider others and not themselves as responsible. Therefore in practice, the necessity to enforce a claim of cost absorption often arises in order to exercise the basic right of free choice of location. Conclusion: Positive effects of the invasive mechanical ventilation (overall survival and symptomatic are highly probable based on the analysed literature, although with a low level of evidence. An establishment of a home ventilation registry and health care research to ascertain valid data to improve outpatient structures is necessary. Gathering specific G

Börger, Sandra

2010-01-01

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Hebbian mechanisms revealed by electrical stimulation at developing rat neuromuscular junctions.  

Science.gov (United States)

Synapse competition and elimination are widespread developmental processes, first demonstrated at neonatal neuromuscular junctions. Action potential activity was long shown to exert a powerful influence, but mechanisms and contribution relative to other factors are still not well understood. Here we show that replacement of natural motoneuronal discharge with synchronous activity suppresses elimination of polyneuronal innervation of myofibers. This requires the simultaneous chronic conduction block (tetrodotoxin) and distal electrical stimulation of motor axons during ectopic synaptogenesis in denervated adult soleus muscle. If in fact chronic stimulation is applied without central block of motor axons, the time course of synapse elimination is as fast as in control muscles undergoing natural activity. Our findings follow the prediction of Hebb's postulate and imply that asynchronous activity drives developmental synapse elimination in muscle. They further suggest that motoneurons could become transiently synchronized during development and regeneration, helping to establish the initial polyneuronal innervation. PMID:10632598

Busetto, G; Buffelli, M; Tognana, E; Bellico, F; Cangiano, A

2000-01-15

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Enhancement of neuromuscular dynamics and strength behavior using extremely low magnitude mechanical signals in mice.  

Science.gov (United States)

Exercise in general, and mechanical signals in particular, help ameliorate the neuromuscular symptoms of aging and possibly other neurodegenerative disorders by enhancing muscle function. To better understand the salutary mechanisms of such physical stimuli, we evaluated the potential for low intensity mechanical signals to promote enhanced muscle dynamics. The effects of daily brief periods of low intensity vibration (LIV) on neuromuscular functions and behavioral correlates were assessed in mice. Physiological analysis revealed that LIV increased isometric force production in semitendinosus skeletal muscle. This effect was evident in both young and old mice. Isometric force recordings also showed that LIV reduced the fatiguing effects of intensive synaptic muscle stimulation. Furthermore, LIV increased evoked neurotransmitter release at neuromuscular synapses but had no effect on spontaneous end plate potential amplitude or frequency. In behavioral studies, LIV increased mouse grip strength and potentiated initial motor activity in a novel environment. These results provide evidence for the efficacy of LIV in producing changes in the neuromuscular system that translate into performance gains at a behavioral scale. PMID:24157062

Mettlach, Gabriel; Polo-Parada, Luis; Peca, Lauren; Rubin, Clinton T; Plattner, Florian; Bibb, James A

2014-01-01

9

The effects of neuromuscular training on knee joint motor control during sidecutting in female elite soccer and handball players  

DEFF Research Database (Denmark)

OBJECTIVE: The project aimed to implement neuromuscular training during a full soccer and handball league season and to experimentally analyze the neuromuscular adaptation mechanisms elicited by this training during a standardized sidecutting maneuver known to be associated with non-contact anterior cruciate ligament (ACL) injury. DESIGN: The players were tested before and after 1 season without implementation of the prophylactic training and subsequently before and after a full season with the implementation of prophylactic training. PARTICIPANTS: A total of 12 female elite soccer players and 8 female elite team handball players aged 26 +/- 3 years at the start of the study. INTERVENTION: The subjects participated in a specific neuromuscular training program previously shown to reduce non-contact ACL injury. METHODS: Neuromuscular activity at the knee joint, joint angles at the hip and knee, and ground reaction forces were recorded during a sidecutting maneuver. Neuromuscular activity in the prelanding phase was obtained 10 and 50 ms before foot strike on a force plate and at 10 and 50 ms after foot strike on a force plate. RESULTS: Neuromuscular training markedly increased before activity and landing activity electromyography (EMG) of the semitendinosus (P < 0.05), while quadriceps EMG activity remained unchanged. CONCLUSIONS: Neuromuscular training increased EMG activity for the medial hamstring muscles, thereby decreasing the risk of dynamic valgus. This observed neuromuscular adaptation during sidecutting could potentially reduce the risk for non-contact ACL injury.

Zebis, Mette K; Bencke, Jesper

2008-01-01

10

Aging and limb alter the neuromuscular control of goal-directed movements.  

Science.gov (United States)

The purpose of this study was to determine whether the neuromuscular control of goal-directed movements is different for young and older adults with the upper and lower limbs. Twenty young (25.1 ± 3.9 years) and twenty older adults (71.5 ± 4.8 years) attempted to accurately match the displacement of their limb to a spatiotemporal target during ankle dorsiflexion or elbow flexion movements. We quantified neuromuscular control by examining the movement endpoint accuracy and variability, and the antagonistic muscle activity using surface electromyography (EMG). Our results indicate that older adults exhibit impaired endpoint accuracy with both limbs due to greater time variability. In addition, older adults exhibit greater EMG burst and lower EMG burst variability as well as lower coactivation of the antagonistic muscles. The impaired accuracy of older adults during upper limb movements was related to lower coactivation of the antagonistic muscles, whereas their impaired accuracy during lower limb movements was related to the amplified EMG bursts. The upper limb exhibited greater movement control than the lower limb, and different neuromuscular parameters were related to the accuracy and consistency for each limb. Greater endpoint error during upper limb movements was related to lower coactivation of the antagonistic muscles, whereas greater endpoint error during lower limb movements was related to the amplified EMG bursts. These findings indicate that the age-associated impairments in movement control are associated with altered activation of the involved antagonistic muscles. In addition, independent of age, the neuromuscular control of goal-directed movements is different for the upper and lower limbs. PMID:24557320

Kwon, MinHyuk; Chen, Yen-Ting; Fox, Emily J; Christou, Evangelos A

2014-06-01

11

Neuromuscular mechanisms of esophageal responses at and proximal to a distending balloon.  

Science.gov (United States)

To determine the neuromuscular mechanisms involved in esophageal responses at and proximal to a distending stimulus, a manometric catheter incorporating a latex balloon at its distal end was positioned in the smooth muscle esophagus of alpha-chloralose-anesthetized opossums and used to record intraluminal pressures over the balloon and at several sites proximal to the balloon. Air inflation of the balloon evoked simultaneous phasic contractions at several sites proximal to the balloon that were abolished by bilateral cervical vagotomy. With the balloon located in the midesophagus, these proximal contractions were also abolished by atropine, and simultaneous suction electrode recordings indicated that they were associated with smooth muscle membrane depolarization and spike burst without preceding hyperpolarization. With the balloon located in the distal esophagus, the evoked proximal contractions were less atropine sensitive. Phasic pressure fluctuations recorded by the balloon itself were not affected by atropine or bilateral cervical vagotomy but were increased in amplitude by tetrodotoxin. These opossum studies suggest that unlike responses below a distending balloon, which have been shown to be noncholinergic and mediated by intramural neuromuscular mechanisms, proximal contractions depend on vagal pathways and, depending on esophageal location, muscarinic-cholinergic transmission. Contractions at the level of the distending balloon appear to be myogenic in origin. PMID:1987803

Paterson, W G

1991-01-01

12

Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control  

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By integrating studies of muscle function with analysis of whole body and limb dynamics, broader appreciation of neuromuscular function can be achieved. Ultimately, such studies need to address non-steady locomotor behaviors relevant to animals in their natural environments. When animals move slowly they likely rely on voluntary coordination of movement involving higher brain centers. However, when moving fast, their movements depend more strongly on responses controlled at more local levels....

2007-01-01

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INFLUENCE OF AGE ON NEUROMUSCULAR CONTROL DURING A DYNAMIC WEIGHT BEARING TASK  

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Neuromuscular control strategies may change with age and predispose elderly to knee joint injury. The purposes of this study were to determine if long latency responses (LLR), muscle activation patterns, and movement accuracy differs between the young and elderly during a novel single limb squat (SLS) task. Ten young and ten elderly subjects performed a series of resistive SLS (~0–30 degrees) while matching a computer-generated sinusoidal target. The SLS device provided a 16% body weight re...

Madhavan, Sangeetha; Burkart, Sarah; Baggett, Gail; Nelson, Katie; Teckenburg, Trina; Zwanziger, Mike; Shields, Richard K.

2009-01-01

14

The influence of auditory and visual information on the neuromuscular control of chewing crispy food.  

Science.gov (United States)

The influence of auditory and/or visual information on the neuromuscular control of chewing a crispy food was investigated. Participants chewed biscuits of three different levels of crispness under four experimental conditions: no masking, auditory masking, visual masking, and auditory plus visual masking. The order of the four masking condition blocks was randomized. The sound of chewing was masked by loud sounds on a headphone, and visual masking of the food was achieved by closing the eyes. Mechanical tests were performed on the biscuits to determine their characteristics, yield force, and sound production. Skull vibration, jaw-muscle activity, and jaw movement were measured while the subjects chewed and swallowed the food. Auditory and/or visual masking did not have a significant effect on skull vibration, muscle activity, and number of chewing cycles until swallowing. However, auditory and/or visual masking significantly increased the chewing cycle duration, but only for the participants who started the experiments with auditory and/or visual masking. The other participants were not influenced by masking. The memory of the unmodified stimuli helped these subjects to maintain their habitual chewing rate in later trials. PMID:22112027

van der Bilt, Andries; Pocztaruk, Rafael L; Frasca, Luis C F; van der Glas, Hilbert W; Abbink, Jan H

2011-12-01

15

Neuromuscular electrical stimulation for stroke rehabilitation: is spinal plasticity a possible mechanism associated with diminished spasticity?  

Science.gov (United States)

Although the specific pathophysiological mechanisms underlying the development of spasticity are not fully understood, a large amount of evidence suggests that abnormalities in spinal pathways regulating the stretch reflex may contribute to the hypertonia and hyperreflexia that characterize spasticity. It is quite interesting that neuromuscular electrical stimulation (NMES) has been reported as an efficient treatment for reducing spasticity after stroke while other reports have shown that it promotes neuroplasticity in healthy subjects. The hypothesis addressed in this paper is that plastic effects within some spinal cord pathways may be a possible mechanism associated with the NMES-induced improvements in spasticity. If the hypothesis is proven corrected, the association between plasticity within specific spinal pathways and NMES-induced improvements in spasticity may be used to guide the choice of stimulation parameters to be used in NMES-based stroke rehabilitation protocols. PMID:24011552

Motta-Oishi, Anna Amélia P; Magalhães, Fernando Henrique; Mícolis de Azevedo, Fábio

2013-11-01

16

Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control.  

Science.gov (United States)

By integrating studies of muscle function with analysis of whole body and limb dynamics, broader appreciation of neuromuscular function can be achieved. Ultimately, such studies need to address non-steady locomotor behaviors relevant to animals in their natural environments. When animals move slowly they likely rely on voluntary coordination of movement involving higher brain centers. However, when moving fast, their movements depend more strongly on responses controlled at more local levels. Our focus here is on control of fast-running locomotion. A key observation emerging from studies of steady level locomotion is that simple spring-mass dynamics, which help to economize energy expenditure, also apply to stabilization of unsteady running. Spring-mass dynamics apply to conditions that involve lateral impulsive perturbations, sudden changes in terrain height, and sudden changes in substrate stiffness or damping. Experimental investigation of unsteady locomotion is challenging, however, due to the variability inherent in such behaviors. Another emerging principle is that initial conditions associated with postural changes following a perturbation define different context-dependent stabilization responses. Distinct stabilization modes following a perturbation likely result from proximo-distal differences in limb muscle architecture, function and control strategy. Proximal muscles may be less sensitive to sudden perturbations and appear to operate, in such circumstances, under feed-forward control. In contrast, multiarticular distal muscles operate, via their tendons, to distribute energy among limb joints in a manner that also depends on the initial conditions of limb contact with the ground. Intrinsic properties of these distal muscle-tendon elements, in combination with limb and body dynamics, appear to provide rapid initial stabilizing mechanisms that are often consistent with spring-mass dynamics. These intrinsic mechanisms likely help to simplify the neural control task, in addition to compensating for delays inherent to subsequent force- and length-dependent neural feedback. Future work will benefit from integrative biomechanical approaches that employ a combination of modeling and experimental techniques to understand how the elegant interplay of intrinsic muscle properties, body dynamics and neural control allows animals to achieve stability and agility over a variety of conditions. PMID:17704070

Biewener, Andrew A; Daley, Monica A

2007-09-01

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Effects of neuromuscular lags on controlling contact transitions  

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We present a numerical exploration of contact transitions with the fingertip. When picking up objects our fingertips must make contact at specific locations, and—upon contact—maintain posture while producing well-directed force vectors. However, the joint torques for moving the fingertip towards a surface (?m) are different from those for producing static force vectors (?f). We previously described the neural control of such abrupt transitions in humans, and found that unavoidable error...

Venkadesan, Madhusudhan; Valero-cuevas, Francisco J.

2009-01-01

18

Early neuromuscular customized training after surgery for lumbar disc herniation: a prospective controlled study  

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A prospective and controlled study of training after surgery for lumbar disc herniation (LDH). The objective was to determine the effect of early neuromuscular customized training after LDH surgery. No consensus exists on the type and timing of physical rehabilitation after LDH surgery. Patients aged 15–50 years, disc prolapse at L4–L5 or L5–S1. Before surgery, at 6 weeks, 4, and 12 months postoperatively, the following evaluations were performed: low back pain and leg pain estimated on...

Millisdotter, Monica; Stro?mqvist, Bjo?rn

2007-01-01

19

Structure of the neuromuscular junction: function and cooperative mechanisms in the synapse.  

Science.gov (United States)

As an overview of the structure of the neuromuscular junction, three items are described focusing on cooperative mechanisms involving the synapse and leading to muscle contraction: (1) presynaptic acetylcholine release regulated by vesicle cycling (exocytosis and endocytosis); the fast-mode of endocytosis requires a large influx of external Ca(2+) and is promoted by the activation of G protein-coupled receptors and receptor tyrosine kinases; (2) postsynaptic acetylcholine receptor clustering mediated by the muscle-specific, Dok7-stimulated tyrosine kinase (MuSK) through two signaling mechanisms: one via agrin-Lrp4-MuSK (Ig1/2 domains) and the second via Wnt-MuSK (Frizzled-like cysteine-rich domain)-adaptor Dishevelled; Wnts/MuSK and Lrp4 direct a retrograde signal to presynaptic differentiation; (3) muscle contractile machinery regulated by Ca(2+) -release and Ca(2+) -influx channels, including the depolarization-activated ryanodine receptor-1 and the receptor- and/or store-operated transient receptor potential canonical. The first mechanism is dysfunctional in Lambert-Eaton myasthenic syndrome, the second in anti-acetylcholine receptor-negative myasthenia gravis (MG), and the third in thymoma-associated MG. PMID:23252893

Takamori, Masaharu

2012-12-01

20

Postoperative effects of neuromuscular exercise prior to hip or knee arthroplasty : a randomised controlled trial  

DEFF Research Database (Denmark)

OBJECTIVE: To investigate the postoperative efficacy of a supervised programme of neuromuscular exercise prior to hip or knee arthroplasty. METHODS: In this assessor-blinded randomised controlled trial, we included 165 patients scheduled for hip or knee arthroplasty due to severe osteoarthritis (OA). An 8-week preoperative neuromuscular supervised exercise programme was delivered twice a week for 1 h as adjunct treatment to the standard arthroplasty procedure and compared with the standard arthroplasty procedure alone. The primary outcome was self-reported physical function measured on the activities of daily living (ADL) subscale in the Hip disability and Osteoarthritis Outcome Score (HOOS) and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires for patients with hip and knee OA, respectively. Primary endpoint was 3 months after surgery. RESULTS: 165 patients randomised to the two groups were on average 67±8 years, 84 (51%) had hip OA and 92 (56%) were women. 153 patients (93%) underwent planned surgery and were evaluated postoperatively. There was no statistically significant difference in effects between hip or knee patients (p=0.7370). Three months postoperatively, no difference was found between groups for ADL (4.4, 95% CI -0.8 to 9.5) or pain (4.5, 95% CI -0.8 to 9.9). However, there was a statistically significant difference indicating an effect of exercise over the entire period (baseline to 3-months postoperatively) (p=0.0029). CONCLUSIONS: Eight weeks of supervised neuromuscular exercise prior to total joint arthroplasty (TJA) of the hip or knee did not confer additional benefits 3 months postoperatively compared with TJA alone. However, the intervention group experienced a statistically significant short-term benefit in ADL and pain, suggesting an earlier onset of postoperative recovery. TRIAL REGISTRATION: ClinicalTrials NCT01003756.

Villadsen, Allan; Overgaard, Søren

2014-01-01

 
 
 
 
21

No effect on performance tests from a neuromuscular warm-up programme in youth female football: a randomised controlled trial  

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The objective of the present randomised controlled trial was to study the effect of a neuromuscular warm-up programme on performance tests in youth female football. less thanbrgreater than less thanbrgreater thanFour youth female football teams with players aged 12-16 years were randomised into an intervention group and control group. The intervention was a 15-min neuromuscular warm-up programme carried out twice a week during the 11-week study period. Baseline and follow-up measurements of p...

2012-01-01

22

Neuromuscular changes after long-lasting mechanically and electrically elicited fatigue.  

Science.gov (United States)

Central fatigue was investigated under an isolated active condition whereby the possible effects of supraspinal fatigue were minimized. Therefore, ten subjects were fatigued by simultaneously and repeatedly mechanically stretching and electrically stimulating their calf muscles for 1 h. This was performed using an ankle ergometer. The active fatigue task included a total of 2400 muscle stretches with an intensity of 10% of the maximal voluntary contraction (MVC). This protocol clearly impaired neuromuscular function, as revealed by a significant reduction in MVC (P Stretch-reflex recordings revealed a notable post-fatigue reduction in the peak-to-peak amplitude (59.1%, P stretch-resisting force of the muscle (14.1%, P < 0.01). The maximal H-reflex declined by 50.5% (P < 0.001) and did not recover while the leg was kept ischemic. It is suggested that the existing protocol with minor metabolic loading can induce central fatigue, which seems to be of reflex origin from the fatigued muscle. Although the role of presynaptic inhibition of Ia terminals is possibly reinforced, disfacilitation via reduced spindle sensitivity cannot be excluded. PMID:11560086

Avela, J; Kyröläinen, H; Komi, P V

2001-08-01

23

Pathogenic immune mechanisms at the neuromuscular synapse: the role of specific antibody-binding epitopes in myasthenia gravis.  

Science.gov (United States)

Autoantibodies against three different postsynaptic antigens and one presynaptic antigen at the neuromuscular junction are known to cause myasthenic syndromes. The mechanisms by which these antibodies cause muscle weakness vary from antigenic modulation and complement-mediated membrane damage to inhibition of endogenous ligand binding and blocking of essential protein-protein interactions. These mechanisms are related to the autoantibody titre, specific epitopes on the target proteins and IgG autoantibody subclass. We here review the role of specific autoantibody-binding epitopes in myasthenia gravis, their possible relevance to the pathophysiology of the disease and potential implications of epitope mapping knowledge for new therapeutic strategies. PMID:24215230

Huijbers, M G; Lipka, A F; Plomp, J J; Niks, E H; van der Maarel, S M; Verschuuren, J J

2014-01-01

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Estimulação elétrica neuromuscular e o alongamento passivo manual na recuperação das propriedades mecânicas do músculo gastrocnêmio imobilizado / Neuromuscular electric stimulation and manual passive stretching when recovering mechanical properties of immobilized gastrocnemius muscles  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliamos a influência da imobilização, remobilização livre, remobilização com alongamento passivo manual, remobilização com estimulação elétrica neuromuscular (NMES) e remobilização por NMES e alongamento passivo manual associados sobre algumas propriedades mecânicas do músculo gastrocnêmio de rata [...] s. Foram avaliadas 60 ratas divididas em seis grupos.Um destes grupos foi usado como controle. Todos os outros grupos tiveram o membro posterior direito imobilizado por 14 dias consecutivos. Destes grupos um foi imobilizado e em seguida avaliado, um foi liberado da imobilização e permaneceu nas gaiolas plásticas por 10 dias, outro foi submetido a técnica de alongamento passivo manual por 10 dias consecutivos, outro foi submetido a NMES por 10 dias consecutivos e o último foi submetido a NMES somado ao alongamento passivo manual por 10 dias consecutivos. Observamos que a imobilização reduziu os valores das propriedades mecânicas avaliadas no músculo. A remobilização livre não restabeleceu nenhuma das propriedades avaliadas. A remobilização por alongamento passivo manual devolveu ao músculo as propriedades de alongamento no limite de proporcionalidade, rigidez e resiliência. A remobilização estimulada por NMES restabeleceu todas as propriedades estudadas. A remobilização por NMES somada ao alongamento passivo restabeleceu as propriedades mecânicas de alongamento no limite máximo e de proporcionalidade e rigidez. Abstract in english We evaluated the influence of immobilization, free remobilization, remobilization with manual passive stretching, remobilization with neuromuscular electric stimulation (NMES) and remobilization with electric stimulation and associated passive stretching on some mechanical properties of the gastrocn [...] emius muscle of female rats. Sixty female rats were assessed, being distributed into 6 experimental groups. One of these groups served as control. The animals of the five remaining groups had their right posterior limb immobilized for 14 consecutive days. From the five groups, one was sacrificed right after the immobilization period, a second group was released from immobilization, a third was submitted to the manual passive stretching technique for 10 consecutive days, a fourth was submitted to NMES for 10 consecutive days and the last one was submitted to NMES and manual passive stretching for 10 consecutive days. We found that the immobilization caused a significant reduction of the mechanical properties values evaluated on the muscle. The free remobilization could not reestablish any of the properties. The remobilization by manual passive stretching restored the mechanical properties of stretching at the proportionality limit, stiffness and resilience. The remobilization stimulated by NMES reestablished all of studied properties. The remobilization by electric stimulation and passive stretching reestablished the mechanical properties of stretching at the maximum limit, proportionality limit, and stiffness.

Leonardo César, Carvalho; Antonio Carlos, Shimano; Celso Hermínio Ferraz, Picado.

25

Estimulação elétrica neuromuscular e o alongamento passivo manual na recuperação das propriedades mecânicas do músculo gastrocnêmio imobilizado Neuromuscular electric stimulation and manual passive stretching when recovering mechanical properties of immobilized gastrocnemius muscles  

Directory of Open Access Journals (Sweden)

Full Text Available Avaliamos a influência da imobilização, remobilização livre, remobilização com alongamento passivo manual, remobilização com estimulação elétrica neuromuscular (NMES e remobilização por NMES e alongamento passivo manual associados sobre algumas propriedades mecânicas do músculo gastrocnêmio de ratas. Foram avaliadas 60 ratas divididas em seis grupos.Um destes grupos foi usado como controle. Todos os outros grupos tiveram o membro posterior direito imobilizado por 14 dias consecutivos. Destes grupos um foi imobilizado e em seguida avaliado, um foi liberado da imobilização e permaneceu nas gaiolas plásticas por 10 dias, outro foi submetido a técnica de alongamento passivo manual por 10 dias consecutivos, outro foi submetido a NMES por 10 dias consecutivos e o último foi submetido a NMES somado ao alongamento passivo manual por 10 dias consecutivos. Observamos que a imobilização reduziu os valores das propriedades mecânicas avaliadas no músculo. A remobilização livre não restabeleceu nenhuma das propriedades avaliadas. A remobilização por alongamento passivo manual devolveu ao músculo as propriedades de alongamento no limite de proporcionalidade, rigidez e resiliência. A remobilização estimulada por NMES restabeleceu todas as propriedades estudadas. A remobilização por NMES somada ao alongamento passivo restabeleceu as propriedades mecânicas de alongamento no limite máximo e de proporcionalidade e rigidez.We evaluated the influence of immobilization, free remobilization, remobilization with manual passive stretching, remobilization with neuromuscular electric stimulation (NMES and remobilization with electric stimulation and associated passive stretching on some mechanical properties of the gastrocnemius muscle of female rats. Sixty female rats were assessed, being distributed into 6 experimental groups. One of these groups served as control. The animals of the five remaining groups had their right posterior limb immobilized for 14 consecutive days. From the five groups, one was sacrificed right after the immobilization period, a second group was released from immobilization, a third was submitted to the manual passive stretching technique for 10 consecutive days, a fourth was submitted to NMES for 10 consecutive days and the last one was submitted to NMES and manual passive stretching for 10 consecutive days. We found that the immobilization caused a significant reduction of the mechanical properties values evaluated on the muscle. The free remobilization could not reestablish any of the properties. The remobilization by manual passive stretching restored the mechanical properties of stretching at the proportionality limit, stiffness and resilience. The remobilization stimulated by NMES reestablished all of studied properties. The remobilization by electric stimulation and passive stretching reestablished the mechanical properties of stretching at the maximum limit, proportionality limit, and stiffness.

Leonardo César Carvalho

2008-01-01

26

Rapid and reversible responses to IVIG in autoimmune neuromuscular diseases suggest mechanisms of action involving competition with functionally important autoantibodies.  

Science.gov (United States)

Intravenous immunoglobulin (IVIG) is widely used in autoimmune neuromuscular diseases whose pathogenesis is undefined. Many different effects of IVIG have been demonstrated in vitro, but few studies actually identify the mechanism(s) most important in vivo. Doses and treatment intervals are generally chosen empirically. Recent studies in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy show that some effects of IVIG are readily reversible and highly dependent on the serum IgG level. This suggests that in some autoantibody-mediated neuromuscular diseases, IVIG directly competes with autoantibodies that reversibly interfere with nerve conduction. Mechanisms of action of IVIG which most likely involve direct competition with autoantibodies include: neutralization of autoantibodies by anti-idiotypes, inhibition of complement deposition, and increasing catabolism of pathologic antibodies by saturating FcRn. Indirect immunomodulatory effects are not as likely to involve competition and may not have the same reversibility and dose-dependency. Pharmacodynamic analyses should be informative regarding most relevant mechanism(s) of action of IVIG as well as the role of autoantibodies in the immunopathogenesis of each disease. Better understanding of the role of autoantibodies and of the target(s) of IVIG could lead to more efficient use of this therapy and better patient outcomes. PMID:24200120

Berger, Melvin; McCallus, Daniel E; Lin, Cindy Shin-Yi

2013-12-01

27

Tai Chi and vestibular rehabilitation improve vestibulopathic gait via different neuromuscular mechanisms: Preliminary report  

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Abstract Background Vestibular rehabilitation (VR) is a well-accepted exercise program intended to remedy balance impairment caused by damage to the peripheral vestibular system. Alternative therapies, such as Tai Chi (TC), have recently gained popularity as a treatment for balance impairment. Although VR and TC can benefit people with vestibulopathy, the degree to which gait improvements may be related to neuromuscular adaptations of the lower extremities for the two differe...

McGibbon Chris A; Krebs David E; Parker Stephen W; Scarborough Donna M; Wayne Peter M; Wolf Steven L

2005-01-01

28

EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients  

Science.gov (United States)

This paper describes the Brain Computer Interface (BCI) system and the experiments to allow post-acute (stroke patients to use electroencephalogram (EEG) to trigger neuromuscular electrical stimulation (NMES)-assisted extension of the wrist/fingers, which are essential pre-requisites for useful hand function. EEG was recorded while subjects performed motor imagery of their paretic limb, and then analyzed to determine the optimal frequency range within the mu-rhythm, with the greatest attenuation. Aided by visual feedback, subjects then trained to regulate their mu-rhythm EEG to operate the BCI to trigger NMES of the wrist/finger. 6 post-acute stroke patients successfully completed the training, with 4 able to learn to control and use the BCI to initiate NMES. This result is consistent with the reported BCI literacy rate of healthy subjects. Thereafter, without the loss of generality, the controller of the NMES is developed and is based on a model of the upper limb muscle (biceps/triceps) groups to determine the intensity of NMES required to flex or extend the forearm by a specific angle. The muscle model is based on a phenomenological approach, with parameters that are easily measured and conveniently implemented.

Tan, Hock Guan; Shee, Cheng Yap; Kong, Keng He; Guan, Cuntai; Ang, Wei Tech

2011-03-01

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Self-tuning, microprocessor-based closed-loop control of atracurium-induced neuromuscular blockade.  

Science.gov (United States)

A self-tuning, closed-loop computerized system was used to maintain atracurium-induced neuromuscular blockade in patients undergoing routine lower abdominal gynaecological surgery. The controller is based on a unique algorithm which utilizes a bi-exponential model wherein two of the variables are estimated on-line. This enables the system to optimize the sizes of subsequent bolus doses according to patient sensitivity. In this study an initial bolus of 0.3 mg kg-1 was given in a trade-off aimed at achieving earlier intubating conditions rather than taking control of relaxation ab initio and obtaining the pre-programmed setpoint of 15% single twitch response (STR) without overshoot. This was successful in all of the 11 patients studied, the mean time from injecting the bolus to intubation being 2.47 (SD 0.95) min and the drug maintenance requirement being 0.34 (0.07) mg kg-1 h-1. This provided a mean value of 10.26% STR with minimal oscillation about the setpoint (average standard deviation = 4.31 (2.53)) for up to 147 min. PMID:3207541

Uys, P C; Morrell, D F; Bradlow, H S; Rametti, L B

1988-12-01

30

Efeitos da estimulação elétrica neuromuscular durante a imobilização nas propriedades mecânicas do músculo esquelético Efectos de la estimulación eléctrica neuromuscular durante la inmovilización en las propiedades mecánicas del músculo esquelético Effects of neuromuscular electric stimulation during immobilization in the mechanical properties of the skeletal muscle  

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Full Text Available A estimulação elétrica neuromuscular (EENM é um importante recurso utilizado em medicina esportiva para acelerar processos de recuperação. O objetivo deste estudo foi analisar os efeitos da EENM durante a imobilização do músculo gastrocnêmio, em posições de alongamento (LP e encurtamento (SP. Para tanto, 60 ratas fêmeas jovens Wistar foram distribuídas em seis grupos e acompanhadas durante sete dias: controle (C, eletroestimuladas (EE, imobilizadas em encurtamento (ISP, imobilizadas em alongamento (ILP, imobilizadas em encurtamento e eletroestimuladas (ISP + EE e imobilizadas em alongamento e eletroestimuladas (ILP + EE. Para a imobilização, o membro posterior direito foi envolvido por uma malha tubular e ataduras de algodão juntamente à atadura gessada. A EENM foi utilizada com freqüência de 50Hz, 10 minutos por dia, totalizando 20 contrações em cada sessão. Após sete dias os animais foram submetidos a eutanásia e os músculos gastrocnêmios retirados para a realização do ensaio mecânico de tração em uma máquina universal de ensaios (EMIC®. A partir dos gráficos carga versus alongamento, foram calculadas as seguintes propriedades mecânicas: alongamento no limite de proporcionalidade (ALP, carga no limite de proporcionalidade (CLP e rigidez. As imobilizações SP e LP promoveram reduções significativas (p La estimulación eléctrica neuromuscular (EENM es un importante recurso utilizado en medicina deportiva para acelerar procesos de recuperación. El objetivo de este estudio ha sido analizar los efectos de la EENM durante la inmovilización del músculo gastrocnemio, en posiciones de alongamiento (LP y contracción (SP. Para tal fin, 60 ratones hembras jóvenes Wistar fueron distribuidas en seis grupos y monitoreadas durante 7 días: control (C, electro estimuladas (EE, inmovilizadas en contracción (ISP, inmovilizadas en alongamiento (ILP, inmovilizadas en contracción y electro estimuladas (ISP + EE e inmovilizadas en alongamiento y electro estimuladas (ILP + EE. Para la inmovilización, el miembro posterior derecho fue envuelto por una malla tubular y vendas de algodón en conjunto con vendas de escayola. La EENM fue utilizada con una frecuencia de 50 Hz, 10 minutos por día, totalizando 20 contracciones en cada sesión. Después de 7 días los animales fueron sometidos a eutanasia y los músculos gastrocnemios fueron retirados para la realización del ensayo mecánico de tracción en una máquina universal de ensayos (EMIC®. A partir de los gráficos carga versus alongamiento se calculó las siguientes propiedades mecánicas: alongamiento en el límite de proporcionalidad (ALP, carga en el límite de proporcionalidad (CLP y rigidez. Las inmovilizaciones SP y LP dieron reducciones significativas (p The neuromuscular electric stimulation (NMES is an important tool used in sports medicine to accelerate the recovery process. The objective of this study was to analyze the effects of NMES during immobilization of the gastrocnemius muscle, in lengthened (LP and shortened positions (SP. Sixty young female Wistar rats were distributed into six groups and followed for 7 days: control (C; electric stimulation (ES; immobilized in shortening (ISP; immobilized in lengthening (ILP; immobilized in shortening and electric stimulation (ISP + ES and immobilized in lengthening and electric stimulation (ILP + ES. For the immobilization, a tubular mesh and cotton rolls together with the plaster were wrapped around the rat's right posterior paw. NMES in a frequency of 50 Hz was used 10 minutes a day, totaling 20 contractions in each session. After 7 days the animals were sacrificed and their gastrocnemius muscles of the right paw were submitted to a mechanical test of traction in a universal test machine (EMIC®. From the load versus elongation curves the following mechanical properties were obtained: elongation in the yield limit (EPL, load in the yield limit (LPL and stiffness. The SP and LP immobilizations promoted significant reductions (p < 0.05 in the EPL and LPL properties, b

João Paulo Chieregato Matheus

2007-02-01

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Efeitos da estimulação elétrica neuromuscular durante a imobilização nas propriedades mecânicas do músculo esquelético / Effects of neuromuscular electric stimulation during immobilization in the mechanical properties of the skeletal muscle / Efectos de la estimulación eléctrica neuromuscular durante la inmovilización en las propiedades mecánicas del músculo esquelético  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A estimulação elétrica neuromuscular (EENM) é um importante recurso utilizado em medicina esportiva para acelerar processos de recuperação. O objetivo deste estudo foi analisar os efeitos da EENM durante a imobilização do músculo gastrocnêmio, em posições de alongamento (LP) e encurtamento (SP). Par [...] a tanto, 60 ratas fêmeas jovens Wistar foram distribuídas em seis grupos e acompanhadas durante sete dias: controle (C), eletroestimuladas (EE), imobilizadas em encurtamento (ISP), imobilizadas em alongamento (ILP), imobilizadas em encurtamento e eletroestimuladas (ISP + EE) e imobilizadas em alongamento e eletroestimuladas (ILP + EE). Para a imobilização, o membro posterior direito foi envolvido por uma malha tubular e ataduras de algodão juntamente à atadura gessada. A EENM foi utilizada com freqüência de 50Hz, 10 minutos por dia, totalizando 20 contrações em cada sessão. Após sete dias os animais foram submetidos a eutanásia e os músculos gastrocnêmios retirados para a realização do ensaio mecânico de tração em uma máquina universal de ensaios (EMIC®). A partir dos gráficos carga versus alongamento, foram calculadas as seguintes propriedades mecânicas: alongamento no limite de proporcionalidade (ALP), carga no limite de proporcionalidade (CLP) e rigidez. As imobilizações SP e LP promoveram reduções significativas (p Abstract in spanish La estimulación eléctrica neuromuscular (EENM) es un importante recurso utilizado en medicina deportiva para acelerar procesos de recuperación. El objetivo de este estudio ha sido analizar los efectos de la EENM durante la inmovilización del músculo gastrocnemio, en posiciones de alongamiento (LP) y [...] contracción (SP). Para tal fin, 60 ratones hembras jóvenes Wistar fueron distribuidas en seis grupos y monitoreadas durante 7 días: control (C), electro estimuladas (EE), inmovilizadas en contracción (ISP), inmovilizadas en alongamiento (ILP), inmovilizadas en contracción y electro estimuladas (ISP + EE) e inmovilizadas en alongamiento y electro estimuladas (ILP + EE). Para la inmovilización, el miembro posterior derecho fue envuelto por una malla tubular y vendas de algodón en conjunto con vendas de escayola. La EENM fue utilizada con una frecuencia de 50 Hz, 10 minutos por día, totalizando 20 contracciones en cada sesión. Después de 7 días los animales fueron sometidos a eutanasia y los músculos gastrocnemios fueron retirados para la realización del ensayo mecánico de tracción en una máquina universal de ensayos (EMIC®). A partir de los gráficos carga versus alongamiento se calculó las siguientes propiedades mecánicas: alongamiento en el límite de proporcionalidad (ALP), carga en el límite de proporcionalidad (CLP) y rigidez. Las inmovilizaciones SP y LP dieron reducciones significativas (p Abstract in english The neuromuscular electric stimulation (NMES) is an important tool used in sports medicine to accelerate the recovery process. The objective of this study was to analyze the effects of NMES during immobilization of the gastrocnemius muscle, in lengthened (LP) and shortened positions (SP). Sixty youn [...] g female Wistar rats were distributed into six groups and followed for 7 days: control (C); electric stimulation (ES); immobilized in shortening (ISP); immobilized in lengthening (ILP); immobilized in shortening and electric stimulation (ISP + ES) and immobilized in lengthening and electric stimulation (ILP + ES). For the immobilization, a tubular mesh and cotton rolls together with the plaster were wrapped around the rat's right posterior paw. NMES in a frequency of 50 Hz was used 10 minutes a day, totaling 20 contractions in each session. After 7 days the animals were sacrificed and their gastrocnemius muscles of the right paw were submitted to a mechanical test of traction in a universal test machine (EMIC®). From the load versus elongation curves the following mechanical properties were obtained: elongation in the yield limit

Matheus, João Paulo Chieregato; Gomide, Liana Barbaresco; Oliveira, Juliana Goulart Prata de; Volpon, José Batista; Shimano, Antônio Carlos.

32

Static balance and function in children with cerebral palsy submitted to neuromuscular block and neuromuscular electrical stimulation: Study protocol for prospective, randomized, controlled trial  

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Full Text Available Abstract Background The use of botulinum toxin A (BT-A for the treatment of lower limb spasticity is common in children with cerebral palsy (CP. Following the administration of BT-A, physical therapy plays a fundamental role in potentiating the functionality of the child. The balance deficit found in children with CP is mainly caused by muscle imbalance (spastic agonist and weak antagonist. Neuromuscular electrical stimulation (NMES is a promising therapeutic modality for muscle strengthening in this population. The aim of the present study is to describe a protocol for a study aimed at analyzing the effects of NMES on dorsiflexors combined with physical therapy on static and functional balance in children with CP submitted to BT- A. Methods/Design Protocol for a prospective, randomized, controlled trial with a blinded evaluator. Eligible participants will be children with cerebral palsy (Levels I, II and III of the Gross Motor Function Classification System between five and 12 years of age, with independent gait with or without a gait-assistance device. All participants will receive BT-A in the lower limbs (triceps surae. The children will then be randomly allocated for either treatment with motor physical therapy combined with NMES on the tibialis anterior or motor physical therapy alone. The participants will be evaluated on three occasions: 1 one week prior to the administration of BT-A; 2 one week after the administration of BT-A; and 3 four months after the administration of BT-A (end of intervention. Spasticity will be assessed by the Modified Ashworth Scale and Modified Tardieu Scale. Static balance will be assessed using the Medicapteurs Fusyo pressure platform and functional balance will be assessed using the Berg Balance Scale. Discussion The aim of this protocol study is to describe the methodology of a randomized, controlled, clinical trial comparing the effect of motor physical therapy combined with NMES on the tibialis anterior muscle or motor physical therapy alone on static and functional balance in children with CP submitted to BT-A in the lower limbs. This study describes the background, hypotheses, methodology of the procedures and measurement of the results. Trial registration RBR5qzs8h

Kazon Soráia

2012-05-01

33

What Is a Neuromuscular Disease?  

Science.gov (United States)

... and muscles meet the muscle-controlling nerve cells (motor neurons) in the spinal cord More than a million people in the United States are affected by some form of neuromuscular disease, and about 40 percent of them are under ...

34

Ankles back in randomized controlled trial (ABrCt: braces versus neuromuscular exercises for the secondary prevention of ankle sprains. Design of a randomised controlled trial  

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Full Text Available Abstract Background Ankle sprains are the most common sports and physical activity related injury. There is extensive evidence that there is a twofold increased risk for injury recurrence for at least one year post injury. In up to 50% of all cases recurrences result in disability and lead to chronic pain or instability, requiring prolonged medical care. Therefore ankle sprain recurrence prevention in athletes is essential. This RCT evaluates the effect of the combined use of braces and neuromuscular training (e.g. proprioceptive training/sensorimotor training/balance training against the individual use of either braces or neuromuscular training alone on ankle sprain recurrences, when applied to individual athletes after usual care. Methods/Design This study was designed as three way randomized controlled trial with one year follow-up. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain in the two months prior to inclusion, were eligible for inclusion. After subjects had finished ankle sprain treatment by means of usual care, they were randomised to any of the three study groups. Subjects in group 1 received an eight week neuromuscular training program, subjects in group 2 received a sports brace to be worn during all sports activities for the duration of one year, and group 3 received a combination of the neuromuscular training program and a sports brace to be worn during all sports activities for the duration of eight weeks. Outcomes were assessed at baseline and every month for 12 months therafter. The primary outcome measure was incidence of ankle sprain recurrences. Secondary outcome measures included the direct and indirect costs of recurrent injury, the severity of recurrent injury, and the residual complaints during and after the intervention. Discussion The ABrCt is the first randomized controlled trial to directly compare the secondary preventive effect of the combined use of braces and neuromuscular training, against the use of either braces or neuromuscular training as separate secondary preventive measures. This study expects to identify the most effective and cost-efficient secondary preventive measure for ankle sprains. The study results could lead to changes in the clinical guidelines on the prevention of ankle sprains, and they will become available in 2012. Trial registration Netherlands Trial Register (NTR: NTR2157

Verhagen Evert ALM

2011-09-01

35

On the mechanism of action of muscle fibre activity in synapse competition and elimination at the mammalian neuromuscular junction.  

Science.gov (United States)

Activity-dependent competition plays a crucial role in the refinement of synaptic connections in the peripheral and central nervous system. The reduction in number of axons innervating each neuromuscular junction during development, i.e. synapse elimination, appears to be one such competitive activity-driven event. Recently, we showed that asynchronous firing of competing presynaptic terminals is a key player in synapse elimination. Although some previous studies suggested that activity of the postsynaptic cell may be an intermediary in the disposal of redundant presynaptic inputs, the mechanism involved remains unknown. In the present study, in order to assess the role of evoked muscle activity in this process, we inhibited the generation of postsynaptic action potentials in muscle fibers in vivo, through the overexpression of inwardly rectifying Kir2.1 and Kir2.2 channels, via electroporation of the soleus muscle in the mouse hindlimb. Electrophysiological and morphological data show that overexpression of potassium channels in the endplate region of neonatal muscle fibres induces membrane hyperpolarization and an increase in conductance, inhibition of the action potential mechanism and prolonged persistence of polyneuronal innervation. These changes are not seen in muscle fibres with overexpression of a non-conducting Kir2.1 mutant. Our results are compatible with the interpretation that the block of action potential generation, even in single endplates, can inhibit synapse elimination through local signalling. PMID:19490025

Favero, M; Massella, O; Cangiano, A; Buffelli, M

2009-06-01

36

Influência da procainamida sobre o bloqueio neuromuscular produzido pelo rocurônio e investigação sobre o mecanismo de ação da procainamida na junção neuromuscular Influencia de la procainamida sobre el bloqueo neuromuscular producido por el rocuronio e investigación sobre el mecanismo de acción de la procainamida en la junción neuromuscular Influence of procainamide on the neuromuscular blockade caused by rocuronium and investigation on the mechanism of action of procainamide on the neuromuscular junction  

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Full Text Available JUSTIFICATIVA E OBJETIVOS: A potencialização da procainamida sobre o bloqueio neuromuscular produzido pela d-tubocurarina já está comprovada, porém o mecanismo é controverso. O objetivo do estudo foi avaliar a influência da procainamida no bloqueio neuromuscular produzido pelo rocurônio e investigar os mecanismos desta interação. MÉTODO: Foram utilizados 15 ratos (250 a 300 g em preparação descrita por Bülbring. Formaram-se os seguintes grupos (n = 5 cada: procainamida - 20 µg.mL-1 (Grupo I; rocurônio - 4 µg.mL-1 (Grupo II e rocurônio - 4 µg.mL-1 e procainamida - 20 µg.mL-1 (Grupo III. Avaliaram-se: 1 a amplitude das contrações musculares sob estimulação indireta em cada grupo, antes e após a adição dos fármacos; 2 os potenciais de placa terminal em miniatura (PPTM; 3 a eficácia da 4-aminopiridina na reversão do bloqueio neuromuscular. O mecanismo da interação foi estudado em Biventer cervicis (n = 5 e diafragma de rato desnervado (n = 5, observando-se a influência da procainamida na resposta à acetilcolina antes e após a adição da procainamida. RESULTADOS: A procainamida isoladamente não alterou as respostas neuromusculares. O bloqueio produzido com o Grupo III foi de 68,6% ± 7,1%, com diferença significativa (p = 0,0067 em relação ao Grupo II (10,4% ± 4,5%, revertido pela 4-aminopiridina. A procainamida ocasionou aumento na freqüência dos PPTM, seguido de bloqueio revertido pela 4-aminopiridina. Em Biventer cervicis a procainamida aumentou a resposta à ação de contração da acetilcolina, resultado não observado com o diafragma desnervado. CONCLUSÕES: A procainamida potencializou o bloqueio produzido pelo rocurônio. As alterações observadas com PPTM e Biventer cervicis identificaram ação pré-sináptica. O antagonismo da 4-aminopiridina sobre o bloqueio dos PPTM sugeriu dessensibilização dos receptores pela procainamida.JUSTIFICATIVA Y OBJETIVOS: La potenciación de la procainamida sobre el bloqueo neuromuscular producido por la d-tubocurarina ya está comprobada, pero sin embargo el mecanismo es controvertido. El objetivo del estudio fue el de evaluar la influencia de la procainamida en el bloqueo neuromuscular producido por el rocuronio e investigar los mecanismos de esa interacción. MÉTODO: Se utilizaron 15 ratones (250 a 300 g en preparación descrita por Bülbring. Se formaron los siguientes grupos (n = 5 cada: procainamida - 20 µg.mL-1 (Grupo I; rocuronio - 4 µg.mL-1 (Grupo II y rocuronio - 4µg.mL-1 y procainamida - 20µg.mL-1 (Grupo III. Se evaluó: 1 la amplitud de las contracciones musculares bajo la estimulación indirecta en cada grupo, antes y después de la adición de los fármacos; 2 los potenciales de placa terminal en miniatura (PPTM; 3 la eficacia de la 4-aminopiridina en la reversión del bloqueo neuromuscular. El mecanismo de la interacción se estudió en Biventer cervicis (n = 5 y diafragma de ratón desnervado (n = 5, observándose la influencia de la procainamida en la respuesta a la acetilcolina antes y después de la adición de la procainamida. RESULTADOS: De forma aislada, la procainamida no alteró las respuestas neuromusculares. El bloqueo producido con el Grupo III fue de 68,6% ± 7,1%, con una diferencia significativa (p = 0,0067 con relación al Grupo II (10,4% ± 4,5%, revertido por la 4-aminopiridina. La procainamida ocasionó un aumento en la frecuencia de los PPTM, seguido de bloqueo revertido por la 4-aminopiridina. En Biventer cervicis, la procainamida aumentó la respuesta a la acción de contracción de la acetilcolina, resultado no observado con el diafragma desnervado. CONCLUSIONES: La procainamida potenció el bloqueo producido por el rocuronio. Las alteraciones observadas con PPTM y Biventer cervicis identificaron una acción presináptica. El antagonismo de la 4-aminopiridina sobre el bloqueo de los PPTMs sugirió la desensibilización de los receptores por la procainamida.BACKGROUND AND OBJECTIVES: It has already been proved that

Thalita Duque Martins

2007-02-01

37

Influência da procainamida sobre o bloqueio neuromuscular produzido pelo rocurônio e investigação sobre o mecanismo de ação da procainamida na junção neuromuscular / Influence of procainamide on the neuromuscular blockade caused by rocuronium and investigation on the mechanism of action of procainamide on the neuromuscular junction / Influencia de la procainamida sobre el bloqueo neuromuscular producido por el rocuronio e investigación sobre el mecanismo de acción de la procainamida en la junción neuromuscular  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese JUSTIFICATIVA E OBJETIVOS: A potencialização da procainamida sobre o bloqueio neuromuscular produzido pela d-tubocurarina já está comprovada, porém o mecanismo é controverso. O objetivo do estudo foi avaliar a influência da procainamida no bloqueio neuromuscular produzido pelo rocurônio e investigar [...] os mecanismos desta interação. MÉTODO: Foram utilizados 15 ratos (250 a 300 g) em preparação descrita por Bülbring. Formaram-se os seguintes grupos (n = 5 cada): procainamida - 20 µg.mL-1 (Grupo I); rocurônio - 4 µg.mL-1 (Grupo II) e rocurônio - 4 µg.mL-1 e procainamida - 20 µg.mL-1 (Grupo III). Avaliaram-se: 1) a amplitude das contrações musculares sob estimulação indireta em cada grupo, antes e após a adição dos fármacos; 2) os potenciais de placa terminal em miniatura (PPTM); 3) a eficácia da 4-aminopiridina na reversão do bloqueio neuromuscular. O mecanismo da interação foi estudado em Biventer cervicis (n = 5) e diafragma de rato desnervado (n = 5), observando-se a influência da procainamida na resposta à acetilcolina antes e após a adição da procainamida. RESULTADOS: A procainamida isoladamente não alterou as respostas neuromusculares. O bloqueio produzido com o Grupo III foi de 68,6% ± 7,1%, com diferença significativa (p = 0,0067) em relação ao Grupo II (10,4% ± 4,5%), revertido pela 4-aminopiridina. A procainamida ocasionou aumento na freqüência dos PPTM, seguido de bloqueio revertido pela 4-aminopiridina. Em Biventer cervicis a procainamida aumentou a resposta à ação de contração da acetilcolina, resultado não observado com o diafragma desnervado. CONCLUSÕES: A procainamida potencializou o bloqueio produzido pelo rocurônio. As alterações observadas com PPTM e Biventer cervicis identificaram ação pré-sináptica. O antagonismo da 4-aminopiridina sobre o bloqueio dos PPTM sugeriu dessensibilização dos receptores pela procainamida. Abstract in spanish JUSTIFICATIVA Y OBJETIVOS: La potenciación de la procainamida sobre el bloqueo neuromuscular producido por la d-tubocurarina ya está comprobada, pero sin embargo el mecanismo es controvertido. El objetivo del estudio fue el de evaluar la influencia de la procainamida en el bloqueo neuromuscular prod [...] ucido por el rocuronio e investigar los mecanismos de esa interacción. MÉTODO: Se utilizaron 15 ratones (250 a 300 g) en preparación descrita por Bülbring. Se formaron los siguientes grupos (n = 5 cada): procainamida - 20 µg.mL-1 (Grupo I); rocuronio - 4 µg.mL-1 (Grupo II) y rocuronio - 4µg.mL-1 y procainamida - 20µg.mL-1 (Grupo III). Se evaluó: 1) la amplitud de las contracciones musculares bajo la estimulación indirecta en cada grupo, antes y después de la adición de los fármacos; 2) los potenciales de placa terminal en miniatura (PPTM); 3) la eficacia de la 4-aminopiridina en la reversión del bloqueo neuromuscular. El mecanismo de la interacción se estudió en Biventer cervicis (n = 5) y diafragma de ratón desnervado (n = 5), observándose la influencia de la procainamida en la respuesta a la acetilcolina antes y después de la adición de la procainamida. RESULTADOS: De forma aislada, la procainamida no alteró las respuestas neuromusculares. El bloqueo producido con el Grupo III fue de 68,6% ± 7,1%, con una diferencia significativa (p = 0,0067) con relación al Grupo II (10,4% ± 4,5%), revertido por la 4-aminopiridina. La procainamida ocasionó un aumento en la frecuencia de los PPTM, seguido de bloqueo revertido por la 4-aminopiridina. En Biventer cervicis, la procainamida aumentó la respuesta a la acción de contracción de la acetilcolina, resultado no observado con el diafragma desnervado. CONCLUSIONES: La procainamida potenció el bloqueo producido por el rocuronio. Las alteraciones observadas con PPTM y Biventer cervicis identificaron una acción presináptica. El antagonismo de la 4-aminopiridina sobre el bloqueo de los PPTMs sugiri

Martins, Thalita Duque; Loyola, Yolanda Christina S.; Braga, Angélica de Fátima de Assunção.

38

Effect of pre-operative neuromuscular training on functional outcome after total knee replacement: a randomized-controlled trial  

Science.gov (United States)

Background Total Knee Replacement (TKR) is the standard treatment for patients with severe knee osteoarthritis (OA). Significant improvement in pain and function are seen after TKR and approximately 80% of patients are very satisfied with the outcome. Functional status prior to TKR is a major predictor of outcome after the intervention. Thus, improving functional status prior to surgery through exercise may improve after surgery outcome. However, results from several previous trials testing the concept have been inconclusive after surgery. Methods/design In a randomized controlled trial (RCT) we will test the effect of a pre-operative neuromuscular trainingprogram versus an attention control program on lower extremity function – before and after surgery. We will enroll 80 participants, aged between 55–90 years, who are scheduled for TKR. In this single-blinded RCT, the intervention group will receive a minimum of 8 and a maximum of 24 training sessions plus 3 educational sessions of the knee school. The control group will receive the 3 educational sessions only. Assessments are performed immediately before and after the intervention (before surgery), at 6?weeks, 3?months and 12?months (after surgery). The primary outcome will include the Chair Stand Test as a measure of leg strength and reaction time. Secondary outcomes are knee function and pain assessed with the self-reported Knee Injury and Osteoarthritis Outcome Score (KOOS). All measurements will be carried out by a specially trained physical therapist, blinded to group allocation. Discussion To our knowledge this is the first single-blinded RCT to test the effect of pre-operative neuromuscular training plus knee school against knee school alone – on knee function and pain, assessed immediately after the interventions prior to surgery and repeatedly after surgery. Trial registration Clinical Trials NCT00913575

2013-01-01

39

Neuromuscular Control Training Programs and Noncontact Anterior Cruciate Ligament Injury Rates in Female Athletes: A Numbers-Needed-to-Treat Analysis  

Science.gov (United States)

Objective: To determine the numbers needed to treat (NNT) and relative risk reduction (RRR) associated with neuromuscular training programs aimed at preventing noncontact anterior cruciate ligament (ACL) injuries in female athletes. Data Sources: We searched PubMed, MEDLINE, SPORT Discus, CINAHL, and Web of Science from 1966 through 2005 using the terms knee, injury, anterior cruciate ligament, ACL, prevention, plyometric, and neuromuscular training. Study Selection: Selected articles were from peer-reviewed journals written in English that described original research studies comparing neuromuscular training programs with control programs to determine the number of noncontact ACL injuries per event exposure or hours of playing time. Five studies met the inclusion criteria and were independently rated by 3 reviewers using the Physiotherapy Evidence Database (PEDro) scale. Consensus PEDro scores ranged from 4 to 7 out of 10. Data Extraction: We used numbers of subjects, ACL injuries, and injury exposure rates to calculate NNT and RRR for each study. The NNT calculations from all studies were based on the number of players across 1 competitive season and were described as NNT benefit or NNT harm. Data Synthesis: All 5 studies demonstrated a prophylactic effect due to the neuromuscular training programs. The pooled NNT estimates showed that 89 individuals (95% confidence interval: 66 to 136) would need to participate in the prophylactic training program to prevent 1 ACL injury over the course of 1 competitive season. Pooled RRR was 70% (95% confidence interval: 54% to 80%) among individuals who participated in the intervention program. One high-quality randomized control trial and 4 medium-quality prospective cohort studies showed mostly consistent findings. Thus, a Strength of Recommendation Taxonomy level of evidence of 1 with a grade B recommendation supports the use of neuromuscular training programs in the prevention of noncontact ACL injuries in female athletes.

Grindstaff, Terry L; Hammill, Robert R; Tuzson, Ann E; Hertel, Jay

2006-01-01

40

Neuromuscular control of scapula muscles during a voluntary task in subjects with Subacromial Impingement Syndrome : A case-control study  

DEFF Research Database (Denmark)

Imbalance of neuromuscular activity in the scapula stabilizers in subjects with Subacromial Impingement Syndrome (SIS) is described in restricted tasks and specific populations. Our aim was to compare the scapular muscle activity during a voluntary movement task in a general population with and without SIS (n=16, No-SIS=15). Surface electromyography was measured from Serratus anterior (SA) and Trapezius during bilateral arm elevation (no-load, 1kg, 3kg). Mean relative muscle activity was calculated for SA and the upper (UT) and lower part of trapezius (LWT), in addition to activation ratio and time to activity onset. In spite of a tendency to higher activity among SIS 0.10-0.30 between-group differences were not significant neither in ratio of muscle activation 0.80-0.98 nor time to activity onset 0.53-0.98. The hypothesized between-group differences in neuromuscular activity of Trapezius and Serratus was not confirmed. The tendency to a higher relative muscle activity in SIS could be due to a pain-related increase in co-activation or a decrease in maximal activation. The negative findings may display the variation in the specific muscle activation patterns depending on the criteria used to define the population of impingement patients, as well as the methodological procedure being used, and the shoulder movement investigated.

Larsen, C M; Søgaard, Karen

2013-01-01

 
 
 
 
41

Effects of repetitive work on proprioception and of stretching on sensory mechanisms : implications for work-related neuromuscular disorders  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the reten...

Bjo?rklund, Martin

2004-01-01

42

Control rod drive mechanism  

International Nuclear Information System (INIS)

Object: To facilitate mounting and removal of a control rod drive mechanism for facilitating inspection and maintenance and also improving the availability of the reactor by providing a housing of a control rod drive mechanism penetrating the pressure vessel of the reactor with a device for mounting and removing the control rod drive mechanism. Structure: A reactor pressure vessel containing a reactor core is provided at its bottom with a control rod drive mechanism housing penetrating the pressure vessel. The housing is provided with a connecting mechanism, which comprises a connecting section having an anti-rotation engagement section, and engagement section meshing with the anti-rotation engagement section, and springs mounted in the connecting section and engagement section. Thus, the control rod drive mechanism can be easily mounted in or removed from the housing by engagement or separation of the connecting section and engagement section in the connecting mechanism. In addition, since the mounting or removal operation can be carried out in a short period of time, it is possible to reduce the possibility of the exposure of operators to radiation and also improve the availability of the reactor. (Moriyama, K.)

1976-01-01

43

Neuromuscular alterations during walking in persons with moderate knee osteoarthritis.  

Science.gov (United States)

This paper compared the neuromuscular responses during walking between those with early-stage knee osteoarthritis (OA) to asymptomatic controls. The rationale for studying those with mild to moderate knee OA was to determine the alterations in response to dynamic loading that might be expected before severe pain, joint space narrowing and joint surface changes occur. We used pattern recognition techniques to explore both amplitude and shape changes of the surface electromyograms recorded from seven muscles crossing the knee joint of 40 subjects with knee OA and 38 asymptomatic controls during a walking task. The principal patterns for each muscle grouping explained over 83% of the variance in the waveforms. This result supported the notion that the main neuromuscular patterns were similar between asymptomatic controls and those with OA, reflecting the specific roles of the major muscles during walking. ANOVA revealed significant (p<0.05) differences in the principal pattern scores reflecting both amplitude and shape alterations in the OA group and among muscles. These differences captured subtle changes in the neuromuscular responses of the subjects with OA throughout different phases of the gait cycle and most likely reflected changes in the mechanical environment (joint loading, instability) and pain. The subjects with OA attempted to increase activity of the lateral sites and reduce activity in the medial sites, having minimal but prolonged activity during late stance. Therefore, alterations in neuromuscular responses were found even in this high functioning group with moderate knee OA. PMID:16213159

Hubley-Kozey, C L; Deluzio, K J; Landry, S C; McNutt, J S; Stanish, W D

2006-08-01

44

Speed adaptation in a powered transtibial prosthesis controlled with a neuromuscular model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Control schemes for powered ankle–foot prostheses would benefit greatly from a means to make them inherently adaptive to different walking speeds. Towards this goal, one may attempt to emulate the intact human ankle, as it is capable of seamless adaptation. Human locomotion is governed by the interplay among legged dynamics, morphology and neural control including spinal reflexes. It has been suggested that reflexes contribute to the changes in ankle joint dynamics that correspond to walkin...

2011-01-01

45

Características e impacto de la sedación, la analgesia y el bloqueo neuromuscular en los pacientes críticos que recibieron ventilación mecánica prolongada / Characteristics and impact of sedation, analgesia, and neuromuscular blockage in critical patients undergoing prolonged mechanical ventilation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivo. Describir el uso de sedantes, analgésicos y bloqueantes neuromusculares (BNM) en los pacientes con ventilación mecánica (VM) prolongada y evaluar los factores asociados a su empleo y asociación con la mortalidad a los 28 días. Diseño. Estudio multicéntrico, prospectivo y observacional de c [...] ohorte. Ámbito. Trece unidades de cuidados intensivos (UCI) en Chile. Pacientes. Pacientes con VM superior a 48h. Excluimos los pacientes con enfermedad neurológica, cirrosis hepática, insuficiencia renal crónica, sospecha de adicción a drogas y limitación precoz del esfuerzo terapéutico. Intervención. Ninguna Variables de interés principales. Proporción de uso y dosis de sedantes, analgésicos y BNM. Nivel de sedación observado (SAS [sedation-agitation scale "escala de sedación-agitación"]). Variables asociadas al nivel de la SAS, y el uso de sedantes, analgésicos y BNM. Regresión logística multivariada de variables asociadas a la mortalidad a los 28 días. Resultados. Participaron 155 pacientes (60±18 años, el 57% eran varones, SOFA 7 [6-10], APACHE II 18 [15-22], el 63% con sepsis y el 47% con lesión pulmonar aguda/síndrome de distrés respiratorio agudo. Los fármacos empleados fueron midazolam (85%; 4 mg/h [1,9-6,8]) y fentanilo (81%; 76 µg/h [39-140]). Un 30% de los pacientes usó BNM al menos un día. El 55% de la SAS fue 1-2. Existe una asociación entre el uso de BNM y la mortalidad a los 28 días, pero ésta no fue consistente en todos los modelos de uso de BNM evaluados. Conclusiones. En el grupo estudiado fue frecuente el uso de sedantes y la presencia de sedación profunda, el midazolam y el fentanilo fueron los fármacos más usados. El uso de BNM podría asociarse de forma independiente a una mayor mortalidad. Abstract in english Aim. To describe use of sedatives, analgesics, and neuromuscular blockers (NMB) in patients undergoing long-term mechanical ventilation and to assess factors associated with their use and their association with mortality at 28 days. Design. Prospective observational multicenter cohort study. Setting [...] . Thirteen intensive care units (ICU) in Chile. Patients. Patients undergoing mechanical ventilation for more than 48h. We excluded patients with neurological disorders, cirrhosis of the liver, chronic renal failure, suspected drug addiction, and early no resuscitation orders. Intervention. None. Main measurements. Proportion of use and dosage of sedatives, analgesics, and NMB. Level of sedation observed (SAS). Variables associated with the Sedation Agitation Scale (SAS), use of sedatives, analgesics, and NMB. Multivariate logistic regression of variables associated to mortality at 28 days. Results. A total of 155 patients participated (60±18 years, 57% male, SOFA 7 [6-10], APACHE II 18 [15-22], 63% with sepsis, and 47% with acute lung injury/adult respiratory distress syndrome. The drugs most frequently used were midazolam (85%, 4 [1.9-6.8]mg/hr) and fentanyl (81%, 76 [39-140]µg/hr). NMB were administered at least 1 day in 30% of patients. SAS score was 1 or 2 in 55% of patients. There was an association between NMB use and mortality at 28 days, but it was not consistent in all the models of NMB evaluated. Conclusions. Sedatives were frequently employed and deep sedation was common. Midazolam and fentanyl were the most frequently administered drugs. The use of NMB might be independently associated to greater mortality.

E., Tobar; G., Bugedo; M., Andresen; M., Aguirre; M.T., Lira; J., Godoy; H., González; A., Hernández; V., Tomicic; J., Castro; J., Jara; H., Ugarte.

46

Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Osteoarthritis of the knee involving predominantly the medial tibiofemoral compartment is common in older people, giving rise to pain and loss of function. Many people experience progressive worsening of the disease over time, particularly those with varus malalignment and increased medial knee joint load. Therefore, interventions that can reduce excessive medial knee loading may be beneficial in reducing the risk of structural progression. Traditional quadriceps strengthening can improve pain and function in people with knee osteoarthritis but does not appear to reduce medial knee load. A neuromuscular exercise program, emphasising optimal alignment of the trunk and lower limb joints relative to one another, as well as quality of movement performance, while dynamically and functionally strengthening the lower limb muscles, may be able to reduce medial knee load. Such a program may also be superior to traditional quadriceps strengthening with respect to improved pain and physical function because of the functional and dynamic nature. This randomised controlled trial will investigate the effect of a neuromuscular exercise program on medial knee joint loading, pain and function in individuals with medial knee joint osteoarthritis. We hypothesise that the neuromuscular program will reduce medial knee load as well as pain and functional limitations to a greater extent than a traditional quadriceps strengthening program. Methods/Design 100 people with medial knee pain, radiographic medial compartment osteoarthritis and varus malalignment will be recruited and randomly allocated to one of two 12-week exercise programs: quadriceps strengthening or neuromuscular exercise. Each program will involve 14 supervised exercise sessions with a physiotherapist plus four unsupervised sessions per week at home. The primary outcomes are medial knee load during walking (the peak external knee adduction moment from 3D gait analysis, pain, and self-reported physical function measured at baseline and immediately following the program. Secondary outcomes include the external knee adduction moment angular impulse, electromyographic muscle activation patterns, knee and hip muscle strength, balance, functional ability, and quality-of-life. Discussion The findings will help determine whether neuromuscular exercise is superior to traditional quadriceps strengthening regarding effects on knee load, pain and physical function in people with medial knee osteoarthritis and varus malalignment. Trial Registration Australian New Zealand Clinical Trials Registry reference: ACTRN12610000660088

Bennell Kim L

2011-12-01

47

Control rod driving mechanisms  

International Nuclear Information System (INIS)

Purpose: To conduct reactor scram by an external signal and, also by a signal for the abnormal temperature from a temperature detector in the nuclear reactor. Constitution: Control rod driving mechanisms magnetically coupling the extension pipe with the elevating mechanism above the reactor core and the holding magnet, and retains a control rod to the lower portion of the extension pipe by way of a latch mechanism. The temperature detector is immersed in reactor coolants. If the temperature of the coolants rises abnormally, bimetal contacts of the temperature detector are opened to interrupt the current supply to the holding electromagnet. Then, the extension pipe released from the magnetic coupling is lowered and the control rod free from latch is rapidly dropped and inserted into the reactor core. Since this procedure is carried out for all of the control rods, the reactor scram can be attained. The feature of this invention resides in that the reactor scram can be attained also by the signal of the reactor core itself even if the signal system for the external signals should be failed. (Horiuchi, T.)

1985-05-13

48

Mechanisms in environmental control  

Energy Technology Data Exchange (ETDEWEB)

The theory of implementation provides methods for decentralization of decisions in societies. By using mechanisms (game forms) it is possible (in theory) to implement attractive states in different economic environments. As an example the market mechanisms can implement Pareto-efficient and individual rational allocations in an Arrow-Debreu economic environment without market failures. And even when there exists externalities the market mechanism sometime can be used if it is possible to make a market for the goods not allocated on a market already - examples are marketable emission permits, and deposit refund systems. But environmental problems can often be explained by the existence of other market failures (e.g. asymmetric information), and then the market mechanism do not work properly. And instead of using regulation or traditional economic instruments (subsidies, charges, fees, liability insurance, marketable emission permits, or deposit refund systems) to correct the problems caused by market failures, some other methods can be used to deal with these problems. This paper contains a survey of mechanisms that can be used in environmental control when the problems are caused by the existence of public goods, externalities, asymmetric information, and indivisible goods in the economy. By examples it will be demonstrated how the Clarke-Groves mechanism, the Cournot-Lindahl mechanism, and other mechanisms can be used to solve specific environmental problems. This is only theory and examples, but a recent field study have used the Cournot-Lindahl mechanism to solve the problem of lake liming in Sweden. So this subject may be of some interests for environmental policy in the future. (au) 23 refs.

Lindeneg, K. [Univ. of Copenhagen, Inst.of Economics (Denmark)

1994-11-01

49

Study of the inhibitor of the crayfish neuromuscular junction by presynaptic voltage control.  

Science.gov (United States)

The inhibitor of the crayfish opener muscle was investigated by a presynaptic voltage control method. Two microelectrodes were inserted into the inhibitor and the amplitude and duration of presynaptic depolarization were controlled by a voltage-clamp amplifier. The inhibitory postsynaptic potential (IPSP) was measured from a muscle fiber located near the presynaptic voltage electrode. Nonlinear summation of IPSP amplitudes was corrected after chloride equilibrium potential was measured. With the use of 5-ms presynaptic pulses, the depolarization-release coupling (D-R) curve constructed from IPSP peak amplitudes (IPSPcor) had a threshold of about -35 mV and reached its maximal level at -5 to -10 mV. Depolarization beyond the maximum led to a suppression of neurotransmitter release. When transmitter release during a presynaptic pulse was completely suppressed, IPSPs activated by tail current could be identified with an average synaptic delay of 2.5 ms. Transmitter secretion triggered by a calcium current activated during the 5-ms pulses (IPSPon) was also measured on the rising phase of an IPSP, at 2.5 ms after the end of the 5-ms pulses. D-R coupling plots measured from IPSPon exhibited a more pronounced suppression than that obtained from IPSPcor. The effect of presynaptic pulse duration on the level of transmitter release was analyzed. Transmitter release increased with increasing duration and was nearly saturated by 20-ms pulses depolarized to 0 mV. The following conditions were identified as necessary to obtain a consistent D-R curve with a clear suppression: 1) small animals, 3.8 cm head to tail, 2) 15 degrees C, 3) 40 mM tetraethylammonium and 1 mM 4-aminopyridine, 4) an extracellular calcium concentration of or = 8 times longer than its actual length. Therefore the upper limit estimate of the space constant of a typical preparation is approximately 3 mm. Results reported here outline morphological and physiological conditions needed to achieve optimal control of the presynaptic branch of the crayfish inhibitor. The cable-release model quantitatively defines the extent of presynaptic voltage control. PMID:9120551

Vyshedskiy, A; Lin, J W

1997-01-01

50

Contribución del soporte nutricional al tratamiento de las alteraciones neuro-musculares del paciente crítico / Contribution of nutritional support to treatment neuromuscular impairments of critically ill patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Las alteraciones neuromusculares que tienen lugar en el paciente crítico han sido atribuidas a factores como la situación séptica, la liberación de mediadores inflamatorioso el empleo de fármacos que afectan desfavorablemente a la función neuro-muscular. El papel de factores metabólicos y nutriciona [...] les en el desarrollo de esta patología ha recibido poca atención. En la actualidad, el empleo de protocolos de control intensivo de la glucemia podría tener gran interés en la prevención de las alteraciones neuro-musculares de los pacientes críticos. Los mecanismos exactos de la implicación de la hiperglucemia en esta patología son, todavía, desconocidos, aunque la evidencia de los datos procedentes de la investigación es importante. La miopatía caquectizante (atrofia muscular) tiene lugar de manera habitual como consecuencia de los cambios obligados por la respuesta metabólica al estrés. El efecto del aporte de nutrientes sobre la ganancia de masa muscular es muy limitado, por lo que deben estudiarse otras acciones dirigidas a recuperar, de manera más rápida, la masa muscular perdida. Deben evitarse pautas agresivas de renutrición con objeto de prevenir el síndrome de realimentación y el consiguiente mayor deterioro de la función muscular. El aporte de substratos específicos, como la glutamina, podría tener un efecto beneficioso en la recuperación de las alteraciones neuro-musculares del paciente crítico. No obstante, no existen aún datos para justificar su empleo si el único objetivo es la recuperación de la función neuro-muscular. Abstract in english Neuromuscular impairments occurring in the critically ill patient have been attributed to factors such as sepsis, release of inflammatory mediators, or the use of drugs unfavorably affecting neuromuscular function. The role of metabolic and nutritional factors in the development of this condition ha [...] s received little attention. Currently, the use of protocols of intensive glycemia monitoring might be of great interest in preventing neuromuscular impairments in critically ill patients. The precise mechanisms of hyperglycemia involvement in this condition are still unknown, although evidence from research data is important. Cachectic myopathy (muscle atrophy) usually is the result of the obliged changes of metabolic response to stress. The effect of nutrients intake on muscle mass gaining is very limited, so that other actions aimed at more rapidly recovering lost muscle mass should be studied. Aggressive renutrition schedules should be avoided in order to prevent re-nutrition syndrome and further deterioration of muscle function. Intake of specific substrates, such as glutamine,might have a beneficial effect on recovering neuromuscular impairments in the critically ill patient. However, there are still no data to justify its use if the only purpose is to recover neuromuscular function.

J. C., Montejo González.

51

Control rod drive mechanism  

International Nuclear Information System (INIS)

A ball screw shaft rotatably inserted and disposed at the inner side of a housing for control rod drive mechanisms and a ball nut which is screw-coupled to the ball screw shaft and moves along the ball screw shaft are made of Ni-Cr-Fe-Mo-Nb alloys. When a control rod is inserted into a reactor pressure vessel, a detector is actuated by a magnetic force of a movable magnet, and the movement of the control rod is detected. Although the ball nut and the ball screw shaft are situated near the detector and they are made of metal components connected to the magnet, they are not magnetized and do not cause misoperation of the position detector by applying undesired effects on the detector. (T.M.)

1989-04-07

52

Immediate Efficacy of Neuromuscular Exercise in Patients with Severe Osteoarthritis of the Hip or Knee : A Secondary Analysis from a Randomized Controlled Trial  

DEFF Research Database (Denmark)

OBJECTIVE: Knowledge about the effects of exercise in severe and endstage osteoarthritis (OA) is limited. The aim was to evaluate the efficacy of a neuromuscular exercise program in patients with clinically severe hip or knee OA. METHODS: This was a randomized controlled assessor-blinded trial. Patients received an educational package (care-as-usual) only, or care-as-usual plus an 8-week neuromuscular exercise intervention (NEMEX-TJR). NEMEX-TJR was supervised by a physiotherapist, twice weekly for 1 h. The primary outcome was Activities of Daily Living (ADL) subscale from the Hip disability and Osteoarthritis Outcome Score (HOOS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. The secondary outcomes were the HOOS/KOOS subscales Pain, Symptoms, Sport and Recreation, and Joint-related Quality of Life. Exploratory outcomes were functional performance measures and lower limb muscle power. RESULTS: Included were 165 patients, 56% female, average age 67 years (SD ± 8), and a body mass index of 30 (SD ± 5), who were scheduled for primary hip or knee replacement. The postintervention difference between mean changes in ADL was 7.2 points (95% CI 3.5 to 10.9, p = 0.0002) in favor of NEMEX-TJR compared with control. Second, there were statistically significant differences between groups in favor of NEMEX-TJR on all self-reported outcomes and most functional performance tests (walk, chair stands, and 1-leg knee bends). Stratified analyses according to joint revealed moderate effect size for ADL for hip patients (0.63, 95% CI 0.26 to 1.00). Corresponding effect size for knee patients was small (0.23 95% CI -0.14 to 0.60). CONCLUSION: Feasibility of neuromuscular exercise was confirmed in patients about to have total joint replacement. Self-reported activities of daily living and objective performance were improved and pain reduced immediately following 8 weeks of neuromuscular exercise. While the effects were moderate in hip OA, they were only small in knee OA. ClinicalTrials.gov Identifier: NCT01003756.

Villadsen, Allan; Overgaard, Søren

2014-01-01

53

Unmammed Gun Control Mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available From ages it has been a desire of humans to achieve the ultimate in security and make his loved ones and loved things secure. It is this desire that prompted him to make the boundaries and secure them too from all unseen and unknown sources. For this it has been always necessary to maintain a huge sum of people to guard and raise alarms in cases of emergencies. To accomplish this we propose a mechanism which will employ image processing in which a camera (webcam will be continuously observing the ‘area under surveillance’. This data will be then processed by a MatLab code which will be running on a PC and will be able to detect a particular colour (Say Red in front of a white back ground (depicting snow. Depending on this processed data the information about the intruder location will be sent to a micro-controller (89c51 via the Serial/Parallel port of the PC and then a motor controlled gun will be used to point in the direction of the intruder. This mechanism will be online i.e. the gun will continuously be pointing in the direction of the intruder. Further depending on range (distance from the gun (fixed range in this project the gun can be activated and a Laser pointer will be switched ON depict “shooting the target”.

LAXMI NIDHI, PRATYUSHA ROY, SRISHTY NAYAK, RAJINE SWETHA R

2013-05-01

54

Neuromuscular disorders in pregnancy.  

Science.gov (United States)

Preexisting and coincident neuromuscular disorders in pregnancy are challenging for clinicians because of the heterogeneity of disease and the limited data in the literature. Many questions arise regarding the effect of disease on the pregnancy, delivery, and newborn in addition to the effect of pregnancy on the course of disease. Each disorder has particular considerations and possible complications. An interdisciplinary team of physicians is essential. This article discusses the most recent literature on neuromuscular disorders in pregnancy including acquired root, plexus, and peripheral nerve lesions; acquired and inherited neuropathies and myopathies; disorders of the neuromuscular junction; and motor neuron diseases. PMID:22840795

Guidon, Amanda C; Massey, E Wayne

2012-08-01

55

Presynaptic k(+) channels, vesicular ca(2+)/h (+) antiport-synaptotagmin, and acetylcholinesterase, three mechanisms cutting short the cholinergic signal at neuromuscular and nerve-electroplaque junctions.  

Science.gov (United States)

In neuromuscular and nerve-electroplaque junctions, nerve impulses can be transmitted at high frequencies. This implies that transmission of individual impulses must be very brief. We describe three mechanisms which curtail the time course of individual impulses at these synapses: (1) opening of presynaptic K(+) channels (delayed rectifier) efficiently curtails the presynaptic action potential. Inhibition of K(+) channel by aminopyridines transforms the normally brief postsynaptic potential (2-3 ms) to a long-lasting "giant" potential (exceeding half a second); (2) a low-affinity Ca(2+)/H(+) antiport ensures rapid Ca(2+) sequestration into synaptic vesicles, curtailing the calcium signal and thereby the duration of transmitter release. Indeed vesicular Ca(2+)/H(+) antiport inhibition by bafilomycin or Sr(2+) prolongs the duration of the postsynaptic potential. We recently showed that synaptotagmin-1 is required for this antiport activity; thus the vesicular Ca(2+)/H(+) antiport might be synaptotagmin itself, or regulated by it; and (3) it is recalled that, in these junctions, acetylcholinesterase is highly concentrated in the synaptic cleft and that anticholinesterases lengthen the endplate time course. Therefore, at three different steps of synaptic transmission, an efficient mechanism curtails the local synaptic signal. When one of these three mechanisms is inhibited, the duration of individual impulses is prolonged, but the synapse loses its faculty to fire at high frequencies. PMID:24390960

Dunant, Yves; Cordeiro, J Miguel

2014-07-01

56

Neuromuscular Diseases and Breathing  

Science.gov (United States)

... Help MDA Search form Search Neuromuscular Diseases and Breathing Breathing is accomplished with the effort of respiratory muscles. ... as air leaves the lungs. The process of breathing in and out, taking in oxygen and exhaling ...

57

Effects of neuromuscular training (NEMEX-TJR) on patient-reported outcomes and physical function in severe primary hip or knee osteoarthritis : a controlled before-and-after study  

DEFF Research Database (Denmark)

The benefits of exercise in mild and moderate knee or hip osteoarthritis (OA) are apparent, but the evidence in severe OA is less clear. We recently reported that neuromuscular training was well tolerated and feasible in patients with severe primary hip or knee OA. The aims of this controlled before-and-after study were to compare baseline status to an age-matched population-based reference group and to examine the effects of neuromuscular training on patient-reported outcomes and physical function in patients with severe primary OA of the hip or knee.

Ageberg, Eva; Nilsdotter, Anna

2013-01-01

58

Neuromuscular versus quadriceps strengthening exercise in patients with medial knee osteoarthritis and varus malalignment : a randomized controlled trial  

DEFF Research Database (Denmark)

OBJECTIVE: To compare the effects of neuromuscular exercise (NEXA) and quadriceps strengthening (QS) on the knee adduction moment (an indicator of mediolateral distribution of knee load), pain, and physical function in patients with medial knee joint osteoarthritis (OA) and varus malalignment. METHODS: One hundred patients with medial knee pain, mostly moderate-to-severe radiographic medial knee OA, and varus malalignment were randomly allocated to one of two 12-week exercise programs. Each program involved 14 individually supervised exercise sessions with a physiotherapist plus a home exercise component. Primary outcomes were peak external knee adduction moment (3-dimensional gait analysis), pain (visual analog scale), and self-reported physical function (Western Ontario and McMaster Universities Osteoarthritis Index). RESULTS: Eighty-two patients (38 [76%] of 50 in the NEXA group and 44 [88%] of 50 in the QS group) completed the trial. There was no significant between-group difference in the change in thepeak knee adduction moment (mean difference 0.13 Nm/[body weight Ã? height]% [95% confidence interval (95% CI) -0.08, 0.33]), pain (mean difference 2.4 mm [95% CI -6.0, 10.8]), or physical function (mean difference -0.8 units [95% CI -4.0, 2.4]). Neither group showed a change in knee moments following exercise, whereas both groups showed similar significant reductions in pain and improvement in physical function. CONCLUSION: Although comparable improvements in clinical outcomes were observed with both neuromuscular and quadriceps strengthening exercise in patients with moderate varus malalignment and mostly moderate-to-severe medial knee OA, these forms of exercise did not affect the knee adduction moment, a key predictor of structural disease progression.

Roos, Ewa M.

2014-01-01

59

Neuromuscular versus quadriceps strengthening exercise in people with medial knee osteoarthritis and varus malalignment : A randomised controlled trial  

DEFF Research Database (Denmark)

Objective: To compare the effects of neuromuscular exercise (NEXA) and quadriceps strengthening (QS) on the knee adduction moment (an indicator of medio-lateral distribution of knee load), pain and physical function in people with medial knee joint osteoarthritis (OA) and varus malalignment. Methods: 100 people with medial knee pain, mostly moderate to severe radiographic medial knee OA, and varus malalignment were randomly allocated to one of two 12-week exercise programs. Each program involved 14 individually supervised exercise sessions with a physiotherapist plus a home exercise component. Primary outcomes were peak external knee adduction moment (3D gait analysis), pain (visual analogue scale), and self-reported physical function (Western Ontario and McMaster Universities Osteoarthritis Index). Results: 82 participants (38/50 (76%) NEXA, 44/50 (88%) QS) completed the trial. There was no significant between-group difference in the change in the peak knee adduction moment (mean difference (95% CI) 0.134 (-0.069 to 0.337) Nm/(BW.HT)%), pain (2.4 (-6.0 to 10.8) mm) or physical function (-0.8 (-4.0 to 2.4) units). Neither group showed a change in knee moments following exercise, whereas both groups showed similar significant reductions in pain and physical dysfunction. Conclusions: Although comparable improvements in clinical outcomes were found for both neuromuscular and quadriceps strengthening exercise in people with moderate varus malalignment and mostly moderate to severe medial knee OA, these forms of exercise did not affect the knee adduction moment, a key predictor of structural disease progression. Australia and New Zealand Clinical Trials Registry (#ACTRN12610000660088) © 2013 American College of Rheumatology.

Bennell, Kim L; Kyriakides, Mary

2014-01-01

60

Effects of neuromuscular electrostimulation in patients with heart failure admitted to ward  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Neuromuscular electrostimulation has become a promising issue in cardiovascular rehabilitation. However there are few articles published in the literature regarding neuromuscular electrostimulation in patients with heart failure during hospital stay. Methods This is a randomized controlled pilot trial that aimed to investigate the effect of neuromuscular electrostimulation in the walked distance by the six-minute walking test in 30 patients a...

de Araújo Carlos José Soares; Gonçalves Fernanda Souza; Bittencourt Hugo Souza; dos Santos Noélia Gonçalves; Junior Sérgio Vitor Mecca; Neves Júlio Leal Bandeira; Fernandes André Maurício Souza; Junior Roque Aras; dos Reis FranciscoJoséFariasBorges; Guimarães Armênio Costa; Junior ErenaldodeSouzaRodrigues; Carvalho Vitor Oliveira

2012-01-01

 
 
 
 
61

Neuromuscular and hormonal factors associated with knee injuries in female athletes. Strategies for intervention.  

Science.gov (United States)

Female athletes who participate in jumping and cutting sports are 4 to 6 times more likely to sustain a serious knee injury than male athletes participating in the same sports. More than 30,000 serious knee injuries are projected to occur in female intercollegiate and high school athletics in the US each year. The majority of these injuries occur by non-contact mechanisms, most often during landing from a jump or making a lateral pivot while running. Knee instability, due possibly to decreased neuromuscular strength and coordination or increased ligamentous laxity, may underlie the increased incidence of knee injury in females. Neuromuscular training can significantly increase dynamic knee stability in female athletes. Female sex hormones (i.e. estrogen, progesterone and relaxin) fluctuate radically during the menstrual cycle and are reported to increase ligamentous laxity and decrease neuromuscular performance and, thus, are a possible cause of decreases in both passive and active knee stability in female athletes. Oral contraceptives stabilise hormone levels during the menstrual cycle and may function to either passively or actively stabilise the knee joint. The long term objective of clinicians and researchers should be to determine the factors that make women more susceptible than men to knee ligament injury and to develop treatment modalities to aid in the prevention of these injuries. The immediate objectives of this review are to examine how female and male athletes differ in neuromuscular and ligamentous control of the lower extremity. The review will examine the effects of neuromuscular training on knee stability. The effects of female hormone levels and oral contraceptives on neuromuscular control of the female athletes' knee will also be discussed. PMID:10840866

Hewett, T E

2000-05-01

62

Neuromuscular junction disorders.  

Science.gov (United States)

Disorders of the neuromuscular junction, such as myasthenia gravis and Lambert-Eaton myasthenic syndrome, constitute an important and treatable class of diseases. Both disorders are typically caused by an immunologically mediated attack on discrete components of the neuromuscular junction, compromise the efficacy of neurotransmitter transmission, and produce clinically distinct syndromes of fatigable muscle weakness. Although the history, clinical examination, and routine antibody testing can be diagnostic in many cases, specialized neurophysiological tests, such as repetitive nerve stimulation and single-fiber electromyography, are essential tools in the diagnostic evaluation of patients with more complicated or atypical conditions. In this review, we introduce primary disorders of the neuromuscular junction, and discuss the salient clinical and laboratory workup appropriate for recognizing these disorders, and the typical findings seen on electrodiagnostic testing with repetitive nerve stimulation and single-fiber electromyography. PMID:23524069

Liang, Chiawen Lucy; Han, Steve

2013-05-01

63

Control rod drive mechanism  

International Nuclear Information System (INIS)

Purpose: To enhance the drive performance of a control rod drive (CRD) and the reliability of the CRD in joining and separating functions with a control rod (CR) by sufficiently enclosing the top of a hollow piston. Constitution: A flange having a bolt hole for mounting a control rod drive (CRD) in a CRD housing is provided at the lower portion of the CRD. A piston tube is arranged at the center of the CRD, and a sealer is mounted at the joint between the piston tube and the inner face of the flange. On the other hand, a hollow piston is engaged between the hollow piston and a cylinder tube, and a sealer for sealing the space of the cylinder tube is mounted at the lower portion of the hollow piston. Further, a joining member with the control rod is mounted at the top of the hollow piston. (Yoshino, Y.)

1980-01-01

64

Control rod drive mechanism  

International Nuclear Information System (INIS)

Purpose: To improve security of the reactor by holding in the reactor core the control rods without functions of emergency insertion in the control rod drives for the BWR type reactors. Constitution: When the pressure switch to detect pressure in the accumulator and the pressure vessel is installed and such pressure is decreased to pressure by which the control rods cannot be inserted on scram within a given period of time, the feed water valve of the feed pipe from the accumulator is opened and the control rods are inserted into the reactor core by accumulator-applied pressure. The feed valve and the drain valve are held in the closed condition when pressure inside the accumulator and the pressure vessel is lowered. Accordingly, the reactor can be improved in safety by previously inserting in the core those control rods for which pressure for emergency insertion cannot be obtained, or by prohibiting more drawing of the rods staying in a half-drawn position. (Kamimura, M.)

1984-11-30

65

Genetics of neuromuscular disorders.  

Science.gov (United States)

Neuromuscular disorders affect the peripheral nervous system and muscle. The principle effect of neuromuscular disorders is therefore on the ability to perform voluntary movements. Neuromuscular disorders cause significant incapacity, including, at the most extreme, almost complete paralysis. Neuromuscular diseases include some of the most devastating disorders that afflict mankind, for example motor neuron disease. Neuromuscular diseases have onset any time from in utero until old age. They are most often genetic. The last 25 years has been the golden age of genetics, with the disease genes responsible for many genetic neuromuscular disorders now identified. Neuromuscular disorders may be inherited as autosomal dominant, autosomal recessive, or X-linked traits. They may also result from mutations in mitochondrial DNA or from de novo mutations not present in the peripheral blood DNA of either parent. The high incidence of de novo mutation has been one of the surprises of the recent increase in information about the genetics of neuromuscular disorders. The disease burden imposed on families is enormous including decision making in relation to presymptomatic diagnosis for late onset neurodegenerative disorders and reproductive choices. Diagnostic molecular neurogenetics laboratories have been faced with an ever-increasing range of disease genes that could be tested for and usually a finite budget with which to perform the possible testing. Neurogenetics has moved from one known disease gene, the Duchenne muscular dystrophy gene in July 1987, to hundreds of disease genes in 2011. It can be anticipated that with the advent of next generation sequencing (NGS), most, if not all, causative genes will be identified in the next few years. Any type of mutation possible in human DNA has been shown to cause genetic neuromuscular disorders, including point mutations, small insertions and deletions, large deletions and duplications, repeat expansions or contraction and somatic mosaicism. The diagnostic laboratory therefore has to be capable of a large number of techniques in order to identify the different mutation types and requires highly skilled staff. Mutations causing neuromuscular disorders affect the largest human proteins for example titin and nebulin. Successful molecular diagnosis can make invasive and expensive diagnostic procedures such as muscle biopsy unnecessary. Molecular diagnosis is currently largely based on Sanger sequencing, which at most can sequence a small number of exons in one gene at a time. NGS techniques will facilitate molecular diagnostics, but not for all types of mutations. For example, NGS is not good at identifying repeat expansions or copy number variations. Currently, diagnostic molecular neurogenetics is focused on identifying the causative mutation(s) in a patient. In the future, the focus might move to prevention, by identifying carriers of recessive diseases before they have affected children. The pathobiology of many of the diseases remains obscure, as do factors affecting disease severity. The aim of this review is to describe molecular diagnosis of genetic neuromuscular disorders in the past, the present and speculate on the future. PMID:22468856

Laing, Nigel G

2012-01-01

66

Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed/agility drills. The outcome measures chosen to assess for interventional efficacy were: 1 Cumberland Ankle Instability Tool (CAIT scores, 2 Star Excursion Balance Test (SEBT reach distances, 3 ankle joint plantar flexion during drop landing and drop vertical jumping, and 4 ground reaction forces (GRFs during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors.

O'Driscoll Jeremiah

2011-06-01

67

Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report  

Science.gov (United States)

Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI) are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed/agility drills. The outcome measures chosen to assess for interventional efficacy were: [1] Cumberland Ankle Instability Tool (CAIT) scores, [2] Star Excursion Balance Test (SEBT) reach distances, [3] ankle joint plantar flexion during drop landing and drop vertical jumping, and [4] ground reaction forces (GRFs) during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors.

2011-01-01

68

Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report  

LENUS (Irish Health Repository)

Abstract Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI) are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed\\/agility drills. The outcome measures chosen to assess for interventional efficacy were: 1 Cumberland Ankle Instability Tool (CAIT) scores, 2 Star Excursion Balance Test (SEBT) reach distances, 3 ankle joint plantar flexion during drop landing and drop vertical jumping, and 4 ground reaction forces (GRFs) during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors.

O'Driscoll, Jeremiah

2011-06-09

69

Neuromuscular Control Training Programs and Noncontact Anterior Cruciate Ligament Injury Rates in Female Athletes: A Numbers-Needed-to-Treat Analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective: To determine the numbers needed to treat (NNT) and relative risk reduction (RRR) associated with neuromuscular training programs aimed at preventing noncontact anterior cruciate ligament (ACL) injuries in female athletes.

Grindstaff, Terry L.; Hammill, Robert R.; Tuzson, Ann E.; Hertel, Jay

2006-01-01

70

Kinesio Taping(®) does not alter neuromuscular performance of femoral quadriceps or lower limb function in healthy subjects: randomized, blind, controlled, clinical trial.  

Science.gov (United States)

The aim of this study was to analyze the immediate effects of applying Kinesio Taping(®) (KT) on the neuromuscular performance of femoral quadriceps, postural balance and lower limb function in healthy subjects. This is a randomized, blind, controlled, clinical trial, where sixty female volunteers (age: 23.3 ± 2.5 years; BMI: 22.2 ± 2.1 kg/m(2)) were randomly assigned to three groups of 20 subjects each: control (10 min at rest); nonelastic adhesive tape (application over the rectus femoris, vastus lateralis and vastus medialis muscles); and KT (KT application over the same muscles). All individuals were assessed for single and triple hops, postural balance (by baropodometry), peak concentric and eccentric torque and electromyographic activity of vastus lateralis, before and after interventions. No significant differences in electromyographic activity of the VL or concentric and eccentric knee peak torque were recorded, between groups and initial and final assessment in any of the three groups. We also observed no significant alteration in single and triple-hop distance and one-footed static balance between the three groups. Application of KT to RF, VL and VM muscles did not significantly change lower limb function, postural balance, knee extensor peak torque or electromyographic activity of VL muscle in healthy women. PMID:22796389

Lins, Caio Alano de Almeida; Neto, Francisco Locks; Amorim, Anita Barros Carlos de; Macedo, Liane de Brito; Brasileiro, Jamilson Simões

2013-02-01

71

Ablation of de novo DNA methyltransferase Dnmt3a in the nervous system leads to neuromuscular defects and shortened lifespan.  

Science.gov (United States)

DNA methylation is an epigenetic mechanism involved in gene regulation and implicated in the functioning of the nervous system. The de novo DNA methyltransferase Dnmt3a is expressed in neurons, but its specific role has not been clarified. Dnmt3a is activated around embryonic day 10.5 in mouse neuronal precursor cells and remains active in postmitotic neurons in the adult. We assessed the role of neuronal Dnmt3a by conditional gene targeting. Mice lacking functional Dnmt3a in the nervous system were born healthy, but degenerated in adulthood and died prematurely. Mutant mice were hypoactive, walked abnormally, and underperformed on tests of neuromuscular function and motor coordination. Loss of Dnmt3a also led to fewer motor neurons in the hypoglossal nucleus and more fragmented endplates in neuromuscular junctions of the diaphragm muscle. Our results implicate a role for Dnmt3a in the neuromuscular control of motor movement. PMID:17477386

Nguyen, Suzanne; Meletis, Konstantinos; Fu, Dongdong; Jhaveri, Sonal; Jaenisch, Rudolf

2007-06-01

72

Feedback control in fractal mechanics  

International Nuclear Information System (INIS)

It is an important application of fractal to introduce the fractal Hausdorff integration to mechanical theory using the self-similarity of fractal. In this paper, we realize the control of the self-similarity of fractal by use of the product auxiliary reference feedback control method. Especially, for the self-similar set - Julia set of the exponential function, we can control its size, position and other aspects through this method.

2009-04-15

73

PROLONGED NEUROMUSCULAR BLOCKADE  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We are presenting a case of prolonged neuromuscular blockade afteremergency cesarean section. A 34 years old, young lady with no previous history of any systemic illness includingneuromuscular disorder reported in the operation t heatre for cesarean section. She was offered standard protocol forgeneral anaesthesia using thiopentone sodium i/v for induction, suxamethonium i/v for intubation, and pancuroniumbromide i/v for intra-operative relaxation. Intra-operative analgesia was obtained with ...

2006-01-01

74

Neuromuscular adaptations to respiratory muscle inactivity  

Science.gov (United States)

Cervical spinal cord injury results in significant functional impairment. It is important to understand the neuroplasticity in response to inactivity of respiratory muscles in order to prevent any associated effects that limit functional recovery. Recent studies have examined the mechanisms involved in inactivity-induced neuroplasticity of diaphragm motor units. Both spinal hemisection at C2 (C2HS) and tetrodotoxin (TTX)-induced phrenic nerve blockade result in diaphragm paralysis and inactivity of axon terminals. However, phrenic motoneurons are inactive with C2HS but remain active after TTX. Diaphragm muscle fibers ipsilateral to C2HS display minimal changes post-injury. Neuromuscular transmission is enhanced following C2HS but impaired following TTX. Synaptic vesicle pool size at diaphragm neuromuscular junctions increases after C2HS, but decreases after TTX. Thus, inactivity-induced neuromuscular plasticity reflects specific adaptations that depend on inactivity at the motoneuron rather than at axon terminals or muscle fibers. Theses results indicate that neuromuscular transmission and functional properties of DIAm fibers can be maintained after spinal cord injury, providing a substrate for functional recovery and/or specific therapeutic approaches such as phrenic pacing.

Mantilla, Carlos B.; Sieck, Gary C.

2009-01-01

75

Caveolin-3 promotes nicotinic acetylcholine receptor clustering and regulates neuromuscular junction activity.  

Science.gov (United States)

The molecular mechanisms that regulate the organization and activity of the neuromuscular junction remain to be fully identified. Caveolae are invaginations of the plasma membrane. Caveolin-3 is the structural protein component of caveolae in muscle cells. We show that caveolin-3 is expressed at the neuromuscular junction, that it associates with the nicotinic acetylcholine receptor (nAChR), and that a lack of caveolin-3 inhibits clustering of the nAChR in myotubes. At the molecular level, we demonstrate that caveolin-3 is a novel muscle-specific kinase (MuSK) binding protein and that altered nAChR clustering in caveolin-3-lacking myotubes results from inhibition of agrin-induced phosphorylation/activation of MuSK and activation of Rac-1. Functional studies in caveolin-3 null mice show abnormal neuromuscular junction activity that is consistent with altered nAChR localization at the sarcolemma. Together, these data identify caveolin-3 as a critical component of the signaling machinery that drives nicotinic acetylcholine receptor clustering and controls neuromuscular junction function. PMID:19940021

Hezel, Michael; de Groat, William C; Galbiati, Ferruccio

2010-01-15

76

Market mechanisms for pollution control  

Energy Technology Data Exchange (ETDEWEB)

The aim of this report is to examine the use of market mechanisms for pollution control. That is, regulatory approaches which harness the power of the market to modify consumption and production patterns so that they are more environmentally benign, by ensuring that prices of goods and services reflect the value of environmental resources used in their production. The report seeks to explain the background to current interest in market mechanisms, evaluating their claimed benefits compared with traditional regulation and standards. The focus of the report is on market mechanisms with potential impacts on the coal industry. 31 refs., 12 tabs.

Vernon, J.L.

1990-08-01

77

Urgencias en patología neuromuscular Emergencies in neuromuscular pathology  

Directory of Open Access Journals (Sweden)

Full Text Available La debilidad muscular aguda (DMA es el síntoma predominante de las urgencias neuromusculares, especialmente si afecta a la musculatura respiratoria u orofaríngea. La DMA es un síndrome plurietiológico y con distintos niveles lesionales en la unidad motora. Dentro del amplio grupo de enfermedades neuromusculares, las que con mayor frecuencia provocan DMA e insuficiencia respiratoria son el síndrome de Guillain-Barré (SGB y la miastenia gravis (MG. El SGB constituye la causa más frecuente de parálisis flácida aguda; puede ocasionar fallo respiratorio en un tercio de los casos precisando ventilación mecánica. El diagnóstico preciso de este síndrome permitirá iniciar tratamiento inmunomodulador, que ha demostrado que modifica el curso de la enfermedad. Además, la valoración clínica de los pacientes y el conocimiento de sencillos tests neurofisiológicos y de función respiratoria guiarán la decisión de ventilación mecánica evitando la intubación de urgencia. La urgencia más frecuente que ocasiona la MG es la crisis miasténica, definida por el deterioro en la función bulbar con insuficiencia respiratoria aguda y riesgo de parada respiratoria. Ocurre en un 15-20% de pacientes miasténicos y puede desencadenarse por múltiples factores. Además del diagnóstico preciso de la crisis es importante la supresión de los factores desencadenantes y medidas de soporte ventilatorio. Entre las medidas farmacológicas son la plasmaféresis y las inmunoglobulinas intravenosas los instrumentos más útiles en la actualidad; estos tratamientos no sustituyen la vigilancia intensiva y el reconocimiento de los signos inminentes de fallo respiratorio que implican soporte ventilatorio invasivo o no invasivo.Acute muscle weakness (AMW is the predominant symptom of neuromuscular emergencies, especially if it affects the respiratory or oropharyngeal musculature . AMW is a multi-etiological syndrome, with different lesion levels in the motor unit. Within the broad group of neuromuscular diseases, those that most frequently provoke AMW and respiratory failure are Guillain-Barré syndrome (GBS and myasthenia gravis (MG. GBS is the most frequent cause of acute flaccid paralysis; it can cause respiratory failure in a third of cases, making mechanical ventilation necessary. Accurate diagnosis of this syndrome enables immunomodulatory treatment to be started, which has been shown to modify the course of the disease. Besides, clinical evaluation of the patients and knowledge of the simple tests of neurophysiology and respiratory function will guide the decision on mechanical ventilation, avoiding emergency intubation. The most frequent emergency caused by MG is myasthenic crisis, defined by the deterioration in the bulbar function with acute respiratory insufficiency and risk of respiratory stoppage. This occurs in 15-20% of myasthenic patients and can be triggered by numerous factors. Besides early identification of the crisis, it is important to suppress the triggering factors and to provide measure of ventilatory support. Amongst the pharmacological measures, the most useful instruments at present are plasmapheresis and intravenous immunoglobulins; these treatments do not cancel the need for intensive vigilance and of checking for imminent signs of respiratory failure that will involve invasive or non-invasive ventilatory support.

T. Ayuso

2008-01-01

78

Applications of skeletal muscle progenitor cells for neuromuscular diseases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Neuromuscular diseases affect skeletal muscle and/or nervous control resulting in direct disruption of skeletal muscle and muscle pathology, or nervous system disruption which indirectly disrupts muscle function. Stem cell-based therapy is well-recognized as a promising approach for several types of diseases including those affecting the neuromuscular system. To design a successful therapeutic strategy, it is important to choose the most appropriate stem cell type. Skeletal muscle progenitor ...

2012-01-01

79

Controlled mechanically activated hydrogen sorption  

Energy Technology Data Exchange (ETDEWEB)

Hydrogen absorption isotherms are measured in a shaker mill, which allows the mechanical activation of the material. A high pressure flexible hose is attached to a SPEX 8000 M shaker mill and the mill is connected to a gas controlling device, in order to monitor and control the applied hydrogen pressure. The influence of the milling during ''in situ'' hydrogenation of a Mn{sub 3}Ti{sub 2}V alloy and the controlled hydrogen absorption by Ca to its hydride CaH{sub 2} is investigated. Pure CaH{sub 2} as the final product after the mechanical activation is identified by X-ray diffraction. For the Ca we demonstrate the measurement of pressure-composition isotherms during milling. (author)

Friedrichs, O.; Borgschulte, A.; Zuettel, A. [Empa, Swiss Federal Laboratories for Materials Testing and Research, Department of Mobility, Environment, and Energy, Division of Hydrogen and Energy, Ueberlandstrasse 129, 8600 Duebendorf (Switzerland)

2008-10-15

80

Optimal Control of Mechanical Systems  

Directory of Open Access Journals (Sweden)

Full Text Available In the present work, we consider a class of nonlinear optimal control problems, which can be called “optimal control problems in mechanics.” We deal with control systems whose dynamics can be described by a system of Euler-Lagrange or Hamilton equations. Using the variational structure of the solution of the corresponding boundary-value problems, we reduce the initial optimal control problem to an auxiliary problem of multiobjective programming. This technique makes it possible to apply some consistent numerical approximations of a multiobjective optimization problem to the initial optimal control problem. For solving the auxiliary problem, we propose an implementable numerical algorithm.

Vadim Azhmyakov

2007-08-01

 
 
 
 
81

Synaptic Defects in the Spinal and Neuromuscular Circuitry in a Mouse Model of Spinal Muscular Atrophy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Spinal muscular atrophy (SMA) is a major genetic cause of death in childhood characterized by marked muscle weakness. To investigate mechanisms underlying motor impairment in SMA, we examined the spinal and neuromuscular circuitry governing hindlimb ambulatory behavior in SMA model mice (SMN?7). In the neuromuscular circuitry, we found that nearly all neuromuscular junctions (NMJs) in hindlimb muscles of SMN?7 mice remained fully innervated at the disease end stage and were capable of elici...

Ling, Karen K. Y.; Lin, Ming-yi; Zingg, Brian; Feng, Zhihua; Ko, Chien-ping

2010-01-01

82

Mechanical control of electroresistive switching.  

Science.gov (United States)

Hysteretic metal-insulator transitions (MIT) mediated by ionic dynamics or ferroic phase transitions underpin emergent applications for nonvolatile memories and logic devices. The vast majority of applications and studies have explored the MIT coupled to the electric field or temperarture. Here, we argue that MIT coupled to ionic dynamics should be controlled by mechanical stimuli, the behavior we refer to as the piezochemical effect. We verify this effect experimentally and demonstrate that it allows both studying materials physics and enabling novel data storage technologies with mechanical writing and current-based readout. PMID:23981113

Kim, Yunseok; Kelly, Simon J; Morozovska, Anna; Rahani, Ehsan Kabiri; Strelcov, Evgheni; Eliseev, Eugene; Jesse, Stephen; Biegalski, Michael D; Balke, Nina; Benedek, Nicole; Strukov, Dmitri; Aarts, J; Hwang, Inrok; Oh, Sungtaek; Choi, Jin Sik; Choi, Taekjib; Park, Bae Ho; Shenoy, Vivek B; Maksymovych, Peter; Kalinin, Sergei V

2013-09-11

83

Mechanical control of electroresistive switching  

Energy Technology Data Exchange (ETDEWEB)

Hysteretic metal-insulator transitions (MIT) mediated by ionic dynamics or ferroic phase transitions underpin emergent applications for non-volatile memories and logic devices. The vast majority of applications and studies have explored the MIT coupled to the electric field or temperarture. Here, we argue that MIT coupled to ionic dynamics should allow control by mechanical stimuli, the behavior we refer to as piezochemical effect. We verify this effect experimentally, and demonstrate that it allows both studying materials physics and enabling novel data storage technologies with mechanical writing and current based read-out.

Kim, Yunseok [ORNL; Kelly, Simon J [ORNL; Strelcov, Evgheni [ORNL; Jesse, Stephen [ORNL; Biegalski, Michael D [ORNL; Balke, Nina [ORNL; Maksymovych, Petro [ORNL; Kalinin, Sergei V [ORNL

2013-01-01

84

Comparison between two different neuromuscular electrical stimulation protocols for the treatment of female stress urinary incontinence: a randomized controlled trial / Comparação de diferentes procedimentos de estimulação elétrica neuromuscular utilizados no tratamento da incontinência urinária de esforço feminina: ensaio clínico randomizado  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese CONTEXTUALIZAÇÃO: A estimulação elétrica neuromuscular (EENM) é amplamente utilizada no tratamento da incontinência urinária de esforço (IUE), no entanto não há consenso na literatura sobre os parâmetros de tratamento mais eficazes. OBJETIVO: Avaliar os procedimentos de EENM intravaginal no tratamen [...] to de mulheres com IUE. MÉTODOS: Participaram do estudo 20 voluntárias com idade média de 55,55±6,51 anos, com diagnóstico clínico de IUE. As voluntárias foram divididas aleatoriamente em dois grupos: grupo 1 (G1), que recebeu EENM com corrente de média frequência, e grupo 2 (G2), com corrente de baixa frequência. A avaliação funcional dos músculos do assoalho pélvico (MAP) foi realizada por meio de perineometria, e a severidade dos sinais e sintomas da IUE foi avaliada, objetivamente, pelo pad test de uma hora e, subjetivamente, pela Escala Visual Analógica (EVA), que mediu o desconforto causado pela incontinência. Para a análise de normalidade dos dados, utilizou-se o teste Shapiro-Wilk, seguido do teste de Friedman para dados não paramétricos. Para a análise dos sintomas relacionados à IUE, usaram-se os testes Exato de Fisher e Mann-Whitney. Em todas as análises, considerou-se o nível de significância de 5%. RESULTADOS: Não houve diferença significativa (p>0,05) entre os grupos em nenhuma variável avaliada. Na comparação intragrupos das avaliações iniciais e finais (após EENM), houve diferença significativa (p Abstract in english BACKGROUND: Neuromuscular electrical stimulation (NMES) is widely treatment for stress urinary incontinence (SUI) but there is no consensus in literature regarding the most effective treatment parameters. OBJECTIVE: To compare two NMESintra-vaginal protocols for the treatment of SUI in women. METHOD [...] S: The study included 20 volunteers with an average age of 55.55±6.51 years and with the clinical diagnosis of SUI. Volunteers were randomly divided into two groups: group 1 (G1) received NMES with medium-frequency current and group 2 (G2) received NMES with low-frequency current. Functional assessments of pelvic floor muscles (PFM) were performed by perineometry. The severity of signs and symptoms were objectively evaluated using the 1 hour pad test and subjectively evaluated using a visual analog scale that measured the discomfort caused by the SUI. Shapiro-Wilk test was used to analyze data normality, and the Friedman test was used to analyze nonparametric data. For analysis of symptoms related to SUI the Fisher exact test and the Mann-Whitney test were used. Significance level of 5% was set for all data analysis. RESULTS: No significant differences (p>0.05) were found between groups for any of the variable assessed. The within group analysis of initial and final evaluations (after NMES) demonstrated significant differences (p

Priscila G. J. M., Alves; Fabiana R., Nunes; Elaine C. O., Guirro.

85

Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is c...

La Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Dura?n, Ramon; Ferna?ndez, Patricia

2010-01-01

86

Urgencias en patología neuromuscular / Emergencies in neuromuscular pathology  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish La debilidad muscular aguda (DMA) es el síntoma predominante de las urgencias neuromusculares, especialmente si afecta a la musculatura respiratoria u orofaríngea. La DMA es un síndrome plurietiológico y con distintos niveles lesionales en la unidad motora. Dentro del amplio grupo de enfermedades ne [...] uromusculares, las que con mayor frecuencia provocan DMA e insuficiencia respiratoria son el síndrome de Guillain-Barré (SGB) y la miastenia gravis (MG). El SGB constituye la causa más frecuente de parálisis flácida aguda; puede ocasionar fallo respiratorio en un tercio de los casos precisando ventilación mecánica. El diagnóstico preciso de este síndrome permitirá iniciar tratamiento inmunomodulador, que ha demostrado que modifica el curso de la enfermedad. Además, la valoración clínica de los pacientes y el conocimiento de sencillos tests neurofisiológicos y de función respiratoria guiarán la decisión de ventilación mecánica evitando la intubación de urgencia. La urgencia más frecuente que ocasiona la MG es la crisis miasténica, definida por el deterioro en la función bulbar con insuficiencia respiratoria aguda y riesgo de parada respiratoria. Ocurre en un 15-20% de pacientes miasténicos y puede desencadenarse por múltiples factores. Además del diagnóstico preciso de la crisis es importante la supresión de los factores desencadenantes y medidas de soporte ventilatorio. Entre las medidas farmacológicas son la plasmaféresis y las inmunoglobulinas intravenosas los instrumentos más útiles en la actualidad; estos tratamientos no sustituyen la vigilancia intensiva y el reconocimiento de los signos inminentes de fallo respiratorio que implican soporte ventilatorio invasivo o no invasivo. Abstract in english Acute muscle weakness (AMW) is the predominant symptom of neuromuscular emergencies, especially if it affects the respiratory or oropharyngeal musculature . AMW is a multi-etiological syndrome, with different lesion levels in the motor unit. Within the broad group of neuromuscular diseases, those th [...] at most frequently provoke AMW and respiratory failure are Guillain-Barré syndrome (GBS) and myasthenia gravis (MG). GBS is the most frequent cause of acute flaccid paralysis; it can cause respiratory failure in a third of cases, making mechanical ventilation necessary. Accurate diagnosis of this syndrome enables immunomodulatory treatment to be started, which has been shown to modify the course of the disease. Besides, clinical evaluation of the patients and knowledge of the simple tests of neurophysiology and respiratory function will guide the decision on mechanical ventilation, avoiding emergency intubation. The most frequent emergency caused by MG is myasthenic crisis, defined by the deterioration in the bulbar function with acute respiratory insufficiency and risk of respiratory stoppage. This occurs in 15-20% of myasthenic patients and can be triggered by numerous factors. Besides early identification of the crisis, it is important to suppress the triggering factors and to provide measure of ventilatory support. Amongst the pharmacological measures, the most useful instruments at present are plasmapheresis and intravenous immunoglobulins; these treatments do not cancel the need for intensive vigilance and of checking for imminent signs of respiratory failure that will involve invasive or non-invasive ventilatory support.

Ayuso, T.; Jericó, I..

87

Influence of simulated neuromuscular noise on movement variability and fall risk in a 3D dynamic walking model.  

Science.gov (United States)

People at risk of falling exhibit increased gait variability, which may predict future falls. However, the causal mechanisms underlying these correlations are not well known. Increased neuronal noise associated with aging likely leads to increased gait variability, which could in turn lead to increased fall risk. This paper presents a model of how changes in neuromuscular noise independently affect gait variability and probability of falling, and aims to determine the extent to which changes in gait variability directly predict fall risk. We used a dynamic walking model that incorporates a lateral step controller to maintain lateral stability. Noise was applied to this controller to approximate neuromuscular noise in humans. Noise amplitude was varied between low amplitudes that did not induce falls and high amplitudes for which the model always fell. With increases in noise amplitude, the model fell more often and after fewer steps. Gait variability increased with noise amplitude and predicted increased probability of falling. Importantly, these relationships were not linear. At either low gait variability or very high gait variability, small increases in noise and variability affected probability of falling very little. Conversely, at intermediate noise and/or variability levels, the same small increases resulted in large increases in probability of falling. Our results validate the idea that age-related increases in neuromuscular noise likely play a direct contributing role in increasing fall risk. However, neuromuscular noise remains only one of many important factors that need to be considered. These findings have important implications for fall prevention research and practice. PMID:20708189

Roos, Paulien E; Dingwell, Jonathan B

2010-11-16

88

Urgencias en patología neuromuscular Emergencies in neuromuscular pathology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

La debilidad muscular aguda (DMA) es el síntoma predominante de las urgencias neuromusculares, especialmente si afecta a la musculatura respiratoria u orofaríngea. La DMA es un síndrome plurietiológico y con distintos niveles lesionales en la unidad motora. Dentro del amplio grupo de enfermedades neuromusculares, las que con mayor frecuencia provocan DMA e insuficiencia respiratoria son el síndrome de Guillain-Barré (SGB) y la miastenia gravis (MG). El SGB constituye la causa más frecu...

2008-01-01

89

Effects of carbohydrates-BCAAs-caffeine ingestion on performance and neuromuscular function during a 2-h treadmill run: a randomized, double-blind, cross-over placebo-controlled study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Carbohydrates (CHOs, branched-chain amino acids (BCAAs and caffeine are known to improve running performance. However, no information is available on the effects of a combination of these ingredients on performance and neuromuscular function during running. Methods The present study was designed as a randomized double-blind cross-over placebo-controlled trial. Thirteen trained adult males completed two protocols, each including two conditions: placebo (PLA and Sports Drink (SPD: CHOs 68.6 g.L-1, BCAAs 4 g.L-1, caffeine 75 mg.L-1. Protocol 1 consisted of an all-out 2 h treadmill run. Total distance run and glycemia were measured. In protocol 2, subjects exercised for 2 h at 95% of their lowest average speeds recorded during protocol 1 (whatever the condition. Glycemia, blood lactate concentration and neuromuscular function were determined immediately before and after exercise. Oxygen consumption (V?O2, heart rate (HR and rate of perceived exertion (RPE were recorded during the exercise. Total fluids ingested were 2 L whatever the protocols and conditions. Results Compared to PLA, ingestion of SPD increased running performance (p = 0.01, maintained glycemia and attenuated central fatigue (p = 0.04, an index of peripheral fatigue (p = 0.04 and RPE (p = 0.006. Maximal voluntary contraction, V?O2, and HR did not differ between the two conditions. Conclusions This study showed that ingestion of a combination of CHOs, BCAAs and caffeine increased performance by about 2% during a 2-h treadmill run. The results of neuromuscular function were contrasted: no clear cut effects of SPD were observed. Trial registration ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT00799630

Peltier Sébastien L

2011-12-01

90

Controlled versus assisted mechanical ventilation.  

Science.gov (United States)

On the basis of currently available data, it can be suggested that maintained spontaneous breathing during mechanical ventilation should not be suppressed even in patients with severe pulmonary dysfunction if no contraindications, such as increased intracranial pressure, are present. Improvements in pulmonary gas exchange, systemic blood flow, and oxygen supply to tissues, which have been observed when spontaneous breathing was allowed during ventilatory support, are reflected in the clinical improvement in the patient's condition, as indicated by significantly fewer days with ventilation, earlier extubation, and shorter stays in the intensive care unit. The positive effects of spontaneous breathing have been documented only for some of the available partial ventilatory support modalities. If ventilatory modalities are limited to those whose positive effects have been documented, then partial ventilatory support can be used as a primary modality even in patients with severe pulmonary dysfunction. Whereas controlled mechanical ventilation followed by weaning with partial ventilatory support modalities has been the earlier standard in ventilation therapy, this approach should be reconsidered in view of the available data. PMID:12205407

Putensen, Christian; Hering, Rudolf; Wrigge, Hermann

2002-02-01

91

Neuromuscular disease classification system.  

Science.gov (United States)

Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns. PMID:23804164

Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M; Serrano, Carmen

2013-01-01

92

Effects of neuromuscular training (NEMEX-TJR) on patient-reported outcomes and physical function in severe primary hip or knee osteoarthritis: a controlled before-and-after study  

Science.gov (United States)

Background The benefits of exercise in mild and moderate knee or hip osteoarthritis (OA) are apparent, but the evidence in severe OA is less clear. We recently reported that neuromuscular training was well tolerated and feasible in patients with severe primary hip or knee OA. The aims of this controlled before-and-after study were to compare baseline status to an age-matched population-based reference group and to examine the effects of neuromuscular training on patient-reported outcomes and physical function in patients with severe primary OA of the hip or knee. Methods 87 patients (60–77 years) with severe primary OA of the hip (n?=?38, 55% women) or knee (n?=?49, 59% women) awaiting total joint replacement (TJR) had supervised, neuromuscular training (NEMEX-TJR) in groups with individualized level and progression of training. A reference group (n?=?43, 53% women) was included for comparison with patients’ data. Assessments included self-reported outcomes (HOOS/KOOS) and measures of physical function (chair stands, number of knee bends/30 sec, knee extensor strength, 20-meter walk test) at baseline and at follow-up before TJR. Analysis of covariance (ANCOVA) was used for comparing patients and references and elucidating influence of demographic factors on change. The paired t-test was used for comparisons within groups. Results At baseline, patients reported worse scores than the references in all HOOS/KOOS subscales (hip 27–47%, knee 14–52%, of reference scores, respectively) and had functional limitations (hip 72–85%, knee 42–85%, of references scores, respectively). NEMEX-TJR (mean 12 weeks (SD 5.6) of training) improved self-reported outcomes (hip 9–29%, knee 7–20%) and physical function (hip 3–18%, knee 5–19%) (p?KOOS subscales by training. The improvement in HOOS/KOOS subscale ADL was greater for patients with knee OA than hip OA, while the improvement in subscale Sport/Rec was greater for patients with hip OA than knee OA. Conclusions Both self-reported outcomes and physical function were clearly worse compared with the reference group. Neuromuscular training with an individualized approach and gradual progression showed promise for improving patient-reported outcomes and physical function even in older patients with severe primary OA of the hip or knee.

2013-01-01

93

Control of a mechanical gripper with a fuzzy controller  

International Nuclear Information System (INIS)

A fuzzy logic system is used to control a mechanical gripper. System is based in a NLX230 fuzzy micro controller. Control rules are programmed by a 68020 microprocessor in the micro controller memory. Stress and its derived are used as feedback signals in the control. This system can adapt its effort to the mechanical resistance of the object between the fingers. (Author)

1995-01-01

94

Patología neuromuscular en cuidados intensivos / Neuromuscular abnormalities in critical illness  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish La patología neuromuscular en los pacientes críticos ha comenzado a ser objeto de un importante número de estudios en los últimos años, si bien aún quedan muchas lagunas en el conocimiento de su etiología, patogenia, tratamiento y pronóstico. Dentro de esta patología debemos distinguir dos grandes g [...] rupos. En el primero, la debilidad muscular aparece antes del ingreso en UCI y es posible identificar una causa conocida. El síndrome de Guillain-Barré y la miastenia grave son las dos entidades que con mayor frecuencia requieren ser atendidas en nuestras unidades. En el segundo grupo, la debilidad muscular se adquiere en la UCI, en pacientes sin enfermedad neuromuscular previa, y es secundaria a la gravedad de la enfermedad que originó su ingreso en esta unidad y/o al tratamiento empleado. La polineuropatía del paciente crítico (PPC) es, de todas ellas, la entidad más precisamente definida y de la que conocemos mejor sus características clínicas, diagnóstico y pronóstico; no obstante, aún quedan muchas sombras en cuanto a su etiopatogenia. Las alteraciones de la placa neuromuscular y sobre todo la miopatía, que frecuentemente coexiste con la PPC, son las otras complicaciones del sistema nervioso periférico que se desarrollan en pacientes críticos. Los avances en el conocimiento de estas afecciones podrían tener un importante impacto, sobre todo para el desarrollo de intervenciones terapéuticas y preventivas efectivas que mejoren el pronóstico de estos pacientes. Abstract in english The spectrum of neuromuscular disease encountered in today's intensive care units (ICU) has evolved over the last few decades. However, in spite of many studies on neuromuscular disorders complicating critical illness as well as its epidemiology, etiology, treatment and prognosis, several key areas [...] remain unclear. Two main groups are found among these neuromuscular abnormalities. The first group includes primary neuromuscular disorders present on admission to the ICU in which a possible etiology can be identified. Guillain-Barré syndrome and myasthenia gravis are two of the most common diseases admitted to ours units. In the second group, weakness is acquired in the ICU in the absence of preexisting neuromuscular disease. It is believed to reflect illnesses or treatments occurring in the ICU. Critical illness polyneuropathy (CIP) is the most clearly defined neuromuscular complication in this group. However, although we have better knowledge of its clinical, diagnosis, and prognosis features, its pathophysiological substrate has not been fully elucidated. Neuromuscular junction defects and specially myopathies, that frequently coexist with CIP, are the others main causes of acquired weakness in critically ill patients. Advances in understanding of these neuromuscular disorders could have an important impact in terms of developing effective preventive and therapeutic interventions that could help to improve the poor prognosis of these patients.

Amaya Villar, R.; Garnacho-Montero, J.; Rincón Ferrari, M.D..

95

Activity-dependent synaptic competition at mammalian neuromuscular junctions.  

Science.gov (United States)

Synapse elimination is a widespread developmental process in the peripheral and central nervous system that brings about refinement of neural connections through epigenetic mechanisms. Here we describe recent advances concerning the role of the pattern of motoneuronal firing, synchronous or asynchronous, in neuromuscular synapse elimination. PMID:15143199

Buffelli, Mario; Busetto, Giuseppe; Bidoia, Carlo; Favero, Morgana; Cangiano, Alberto

2004-06-01

96

Protein defects in neuromuscular diseases  

Directory of Open Access Journals (Sweden)

Full Text Available Muscular dystrophies are a heterogeneous group of genetically determined progressive disorders of the muscle with a primary or predominant involvement of the pelvic or shoulder girdle musculature. The clinical course is highly variable, ranging from severe congenital forms with rapid progression to milder forms with later onset and a slower course. In recent years, several proteins from the sarcolemmal muscle membrane (dystrophin, sarcoglycans, dysferlin, caveolin-3, from the extracellular matrix (alpha2-laminin, collagen VI, from the sarcomere (telethonin, myotilin, titin, nebulin, from the muscle cytosol (calpain 3, TRIM32, from the nucleus (emerin, lamin A/C, survival motor neuron protein, and from the glycosylation pathway (fukutin, fukutin-related protein have been identified. Mutations in their respective genes are responsible for different forms of neuromuscular diseases. Protein analysis using Western blotting or immunohistochemistry with specific antibodies is of the utmost importance for the differential diagnosis and elucidation of the physiopathology of each genetic disorder involved. Recent molecular studies have shown clinical inter- and intra-familial variability in several genetic disorders highlighting the importance of other factors in determining phenotypic expression and the role of possible modifying genes and protein interactions. Developmental studies can help elucidate the mechanism of normal muscle formation and thus muscle regeneration. In the last fifteen years, our research has focused on muscle protein expression, localization and possible interactions in patients affected by different forms of muscular dystrophies. The main objective of this review is to summarize the most recent findings in the field and our own contribution.

Vainzof M.

2003-01-01

97

Protein defects in neuromuscular diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Muscular dystrophies are a heterogeneous group of genetically determined progressive disorders of the muscle with a primary or predominant involvement of the pelvic or shoulder girdle musculature. The clinical course is highly variable, ranging from severe congenital forms with rapid progression to [...] milder forms with later onset and a slower course. In recent years, several proteins from the sarcolemmal muscle membrane (dystrophin, sarcoglycans, dysferlin, caveolin-3), from the extracellular matrix (alpha2-laminin, collagen VI), from the sarcomere (telethonin, myotilin, titin, nebulin), from the muscle cytosol (calpain 3, TRIM32), from the nucleus (emerin, lamin A/C, survival motor neuron protein), and from the glycosylation pathway (fukutin, fukutin-related protein) have been identified. Mutations in their respective genes are responsible for different forms of neuromuscular diseases. Protein analysis using Western blotting or immunohistochemistry with specific antibodies is of the utmost importance for the differential diagnosis and elucidation of the physiopathology of each genetic disorder involved. Recent molecular studies have shown clinical inter- and intra-familial variability in several genetic disorders highlighting the importance of other factors in determining phenotypic expression and the role of possible modifying genes and protein interactions. Developmental studies can help elucidate the mechanism of normal muscle formation and thus muscle regeneration. In the last fifteen years, our research has focused on muscle protein expression, localization and possible interactions in patients affected by different forms of muscular dystrophies. The main objective of this review is to summarize the most recent findings in the field and our own contribution.

Vainzof, M.; Zatz, M..

98

Caffeine Ingestion Reverses the Circadian Rhythm Effects on Neuromuscular Performance in Highly Resistance-Trained Men  

Science.gov (United States)

Purpose To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. Methods Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i) morning (10:00 a.m.) with caffeine ingestion (i.e., 3 mg kg?1; AMCAFF trial); ii) morning (10:00 a.m.) with placebo ingestion (AMPLAC trial); and iii) afternoon (18:00 p.m.) with placebo ingestion (PMPLAC trial). A randomized, double-blind, crossover, placebo controlled experimental design was used, with all subjects serving as their own controls. The neuromuscular test battery consisted in the measurement of bar displacement velocity during free-weight full-squat (SQ) and bench press (BP) exercises against loads that elicit maximum strength (75% 1RM load) and muscle power adaptations (1 m s?1 load). Isometric maximum voluntary contraction (MVCLEG) and isometric electrically evoked strength of the right knee (EVOKLEG) were measured to identify caffeine's action mechanisms. Steroid hormone levels (serum testosterone, cortisol and growth hormone) were evaluated at the beginning of each trial (PRE). In addition, plasma norepinephrine (NE) and epinephrine were measured PRE and at the end of each trial following a standardized intense (85% 1RM) 6 repetitions bout of SQ (POST). Results In the PMPLAC trial, dynamic muscle strength and power output were significantly enhanced compared with AMPLAC treatment (3.0%–7.5%; p?0.05). During AMCAFF trial, muscle strength and power output increased above AMPLAC levels (4.6%–5.7%; p?0.05) except for BP velocity with 1 m s?1 load (p?=?0.06). During AMCAFF, EVOKLEG and NE (a surrogate of maximal muscle sympathetic nerve activation) were increased above AMPLAC trial (14.6% and 96.8% respectively; p?0.05). Conclusions These results indicate that caffeine ingestion reverses the morning neuromuscular declines in highly resistance-trained men, raising performance to the levels of the afternoon trial. Our electrical stimulation data, along with the NE values, suggest that caffeine increases neuromuscular performance having a direct effect in the muscle.

Mora-Rodriguez, Ricardo; Pallares, Jesus Garcia; Lopez-Samanes, Alvaro; Ortega, Juan Fernando; Fernandez-Elias, Valentin E.

2012-01-01

99

Neuromuscular activity and knee kinematics in adolescents with patellofemoral pain  

DEFF Research Database (Denmark)

This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS).

Rathleff, Michael Skovdal; Samani, Afshin

2013-01-01

100

Neuromuscular Activity and Knee Kinematics in Adolescents with Patellofemoral Pain  

DEFF Research Database (Denmark)

: Purpose: To investigate neuromuscular control of the knee during stair descent among female adolescents with Patellofemoral Pain (PFP) and report its association with self-reported clinical status assessed by the Knee injury and Osteoarthritis Outcome Score (KOOS).Methods: Fifty-seven previously untreated female adolescents diagnosed with PFP aged 15 to 19 years were recruited from schools. The control group consisted of 29 age-matched healthy female adolescents. Bipolar surface electrodes were placed on VM and VL and an electronic knee goniometer was placed at the knee to collect knee flexion/extension kinematics. The participants walked down a stairway consisting of 24 steps at their normal pace. Sample Entropy was used to quantify the complexity of the time series from surface electromyography (sEMG) and kinematics during the stance phase. Self-reported clinical status was assessed by the KOOS and maximal quadriceps torque measured using strap-mounted handheld dynamometry.Results: Female adolescents withPFP were characterized by altered neuromuscular knee control during stair descent, lower maximal quadriceps torque, and poorer KOOS scores across all five domains. Furthermore, a positive association was found between the complexity of sEMG from VL and self-reported pain determined by KOOSpain indicating larger impairments in neuromuscular knee control among those with the highest pain levels.Conclusion: The current findings show that female adolescents with PFP are characterized by altered neuromuscular control of the knee during stair descent and lower maximal quadriceps torque. These results suggest that rehabilitation is needed, and should focus on restoring neuromuscular control and muscle strength.

Rathleff, Michael Skovdal; Samani, Afshin

2013-01-01

 
 
 
 
101

Mechanical control of nanomaterials and nanosystems.  

Science.gov (United States)

In situations of power outage or shortage, such as periods just following a seismic disaster, the only reliable power source available is the most fundamental of forces i.e., manual mechanical stimuli. Although there are many macroscopic mechanical tools, mechanical control of nanomaterials and nanosystems has not been an easy subject to develop even by using advanced nanotechnological concepts. However, this challenge has now become a hot topic and many new ideas and strategies have been proposed recently. This report summarizes recent research examples of mechanical control of nanomaterials and nanosystems. Creation of macroscopic mechanical outputs by efficient accumulation of molecular-level phenomena is first briefly introduced. We will then introduce the main subject: control of molecular systems by macroscopic mechanical stimuli. The research described is categorized according to the respective areas of mechanical control of molecular structure, molecular orientation, molecular interaction including cleavage and healing, and biological and micron-level phenomena. Finally, we will introduce two more advanced approaches, namely, mechanical strategies for microdevice fabrication and mechanical control of molecular machines. As mechanical forces are much more reliable and widely applicable than other stimuli, we believe that development of mechanically responsive nanomaterials and nanosystems will make a significant contribution to fundamental improvements in our lifestyles and help to maintain and stabilize our society. PMID:21953700

Ariga, Katsuhiko; Mori, Taizo; Hill, Jonathan P

2012-01-10

102

Autoimmune disorders of the neuromuscular junction  

Directory of Open Access Journals (Sweden)

Full Text Available The neuromuscular junction (NMJ is a specialized synapse with a complex structural and functional organization. It is a target for a variety of immunological disorders and these diseases usually respond well to immunotherapies. The understanding of the immunological basis of myasthenia gravis, the most common neuromuscular junction disorder, has improved in the recent years. Most patients have antibodies to the acetylcholine receptor (AChR, but around 10% have AChR antibodies that are only identified by novel methods, and up to 5% have muscle-specific kinase antibodies which define a different subgroup of myasthenia. The spectrum of antibodies and their pathophysiological aspects are being elucidated. Even though less common, Lambert Eaton myasthenic syndrome (LEMS is important to recognize. The abnormality in LEMS is a presynaptic failure to release enough packets of ACh, caused by antibodies to the presynaptic voltage-gated calcium channels. More than half these patients have a small cell carcinoma of lung. Acquired neuromyotonia (NMT is a condition associated with muscle hyperactivity. Clinical features include muscle stiffness, cramps, myokymia, pseudomyotonia and weakness. The immune mechanisms of acquired NMT relate to loss of voltage-gated potassium channel function. This review will focus on the important recent developments in the immune-mediated disorders of the NMJ.

Vincent Angela

2008-01-01

103

The mechanisms of price control  

International Nuclear Information System (INIS)

The privatization of previously state-controlled industries, both in the U.K. and elsewhere, has focused attention on their economic regulation. This paper looks at the economic basis for such regulation and in particular the RPI-X system of price control. Privatized utilities in the U.K. are subject to this form of regulation. The price-cap formulae used in regulating the various U.K. utilities are analysed in depth; examining not only their common features but also their significant differences. As with any form of regulation, there is a tendency for over-intervention, and the paper concludes with some observations on this point. (author)

1992-01-01

104

Neuromuscular dressing effects: a literature review  

Directory of Open Access Journals (Sweden)

Full Text Available The kinesio taping is a technique that was created in 1979 by Doctor Kenzo Kase I’m looking through it that could generate a new therapeutic option to control pain, improve athletic performance and reduce the impact of musculoskeletal disorders. From the Sydney 2000 Olympic Games, this technique as a therapeutic alternative PTO and is composed of health professionals in the field of sport and physical rehabilitation.Objetive: This article aims to identify theoretical approaches on the bandage neuromuscular. Material and methods: held today, for which conducted a literature search of databases such as como Proquest, Ovid, Cochraine, PEDro, Journal of Orthopedic and Sports Physical, Sciencedirect, Pubmed y Literatura Latinoamericana y del Caribe en Ciencias de la Salud (Lilacs.The paper proposes a scheme of contextualization of the current landscape of the use and effects of kinesio taping in the management of different pathologies of the musculo-skeletal system in sports. Conclusion: it is concluded that currently many health professionals, and take the neuromuscular bandage a good therapeutic option in the management of diseases affecting the human body is investigated and every day more about the subject, which makes these new therapeutic methods to acquire a scientific value and transcends knowledge.

Calero PA

2012-05-01

105

Neuromuscular Disease Descriptions  

Science.gov (United States)

... addressing any underlying respiratory or heart problems. Peripheral motor neuron diseases (involving muscle-controlling nerve cells of the arms, ... vary. Often associated with diabetes and heart disease. Motor neuron diseases (involving nerve cells in the spinal cord) Infantile ...

106

Neuromuscular ultrasound in common entrapment neuropathies.  

Science.gov (United States)

Neuromuscular ultrasound involves the use of high-resolution ultrasound to image the peripheral nervous system of patients with suspected neuromuscular diseases. It complements electrodiagnostic studies well by providing anatomic information regarding nerves, muscles, vessels, tendons, ligaments, bones, and other structures that cannot be obtained with nerve conduction studies and electromyography. Neuromuscular ultrasound has been studied extensively over the past 10 years and has been used most often in the assessment of entrapment neuropathies. This review focuses on the use of neuromuscular ultrasound in 4 of the most common entrapment neuropathies: carpal tunnel syndrome, ulnar neuropathy at the elbow and wrist, and fibular neuropathy at the knee. PMID:23681885

Cartwright, Michael S; Walker, Francis O

2013-11-01

107

Assessment of vibratory stimulation on neuromuscular system  

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The thesis analyze a subject of renewed interest in bioengineering, the research and analysis of exercise parameters that maximize the neuromuscular and cardiovascular involvement in vibration treatment.

Di Iorio, Felice

2013-01-01

108

Neuromuscular junction integrity after chronic nerve compression injury.  

Science.gov (United States)

Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves. PMID:18655131

Mozaffar, Tahseen; Strandberg, Erika; Abe, Kazuko; Hilgenberg, Lutz G; Smith, Martin A; Gupta, Ranjan

2009-01-01

109

Geometric Computational Mechanics and Optimal Control.  

Science.gov (United States)

The research performed during this AFOSR grant has extended the basic discrete DMOC (Discrete Mechanics and Optimal Control) framework to derive algorithms for general nonholonomic multi-body systems, with applications to a variety of problems including s...

M. Desbrun M. Kobilarov

2011-01-01

110

SLEEP, SLEEP DISORDERED BREATHING, AND NOCTURNAL HYPOVENTILATION IN CHILDREN WITH NEUROMUSCULAR DISEASES  

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Sleep disordered breathing (SDB) is now well recognized in children with neuromuscular diseases (NMD) and may lead to significant morbidity and increased mortality. Predisposing factors to SDB in children with NMD include reduced ventilatory responses, reduced activity of respiratory muscles during sleep and poor lung mechanics due to the underlying neuro-muscular disorder. SDB may present long before signs of respiratory failure emerge. When untreated, SDB may contribute to significant cardi...

Arens, Raanan; Muzumdar, Hiren

2010-01-01

111

Ultrastructural localization of calcium in neuromuscular junctions of smooth and skeletal muscles after aminoglycoside antibiotics treatment  

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Aminoglycoside antibiotics are all capable of producing clinically significant neuromuscular paralysis. Since part of the mechanism of action of these antibiotics at neuromuscular junction is a calciumdependent inhibition of acetylcholine release, so this experiment was carried out in vitro on both somatic (isolated rat phrenic-nerve hemidiaphragm) and autonomic neuro-effector transmission (guinea-pig ileum) using gentamicin and amikacin, to determine the c...

Nouhnejad, P.; Dehpour, A. R.; Samadian, T.; Amini, Sh

1994-01-01

112

Implementation of a guideline for the treatment of pain, sedation, agitation and neuromuscular blockade in the mechanically ventilated adult patient in the emergency department  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Kristin E White1, Paul M Szumita1, Nicki Gilboy2, Hillary A Keenan3, Christian Arbelaez21Department of Pharmacy Services, 2Department of Emergency Medicine, 3Center for Clinical Investigation, Brigham and Women's Hospital, Boston, MA, USAPurpose: When emergency department (ED) overcrowding includes admitted mechanically ventilated (MV) critically-ill patients without an open intensive care unit (ICU) bed, emergency providers must deliver ICU level care in the ED. Implementing standardized...

2011-01-01

113

A reversible mechanical remote-control device  

International Nuclear Information System (INIS)

Description is given of a device for the remote control of a mechanical assembly, as regards displacements and stresses. The mechanical assembly, actuated by a motor, is characterized in that it is reversible and comprises a displacement sensor adapted to deliver a pulse each time a shaft for moving said mechanical assembly associated to said motor has rotated by one step, the sign of that pulse depending, on the direction of the rotation of the motor, said pulses feeding an adding-device, the other input of which is fed with pulses delivered by a unit controlling the motor and constituting motor positioning orders, the output of said adding-device being re-injected in the control unit, thus providing a stress return, on the one hand and introduced into the input of an amplifier-circuit controlling the torque of said motor, on the other hand. This can be applied to manipulators

1974-01-01

114

Fatigue syndromes: a comparison of chronic "postviral" fatigue with neuromuscular and affective disorders.  

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Patients (n = 47) presenting to a neurological centre with unexplained chronic "postviral" fatigue (CFS) were studied prospectively. Controls were patients with peripheral fatiguing neuromuscular diseases and inpatients with major depression in a psychiatric hospital. Seventy-two percent of the CFS patients were cases of psychiatric disorder, using criteria that excluded fatigue as a symptom, compared with 36% of the neuromuscular group. There was no difference in subjective complaints of phy...

Wessely, S.; Powell, R.

1989-01-01

115

Electrophysiological study in neuromuscular junction disorders  

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This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG) helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS). SFEMG requires skill and patience and its availability i...

2013-01-01

116

Facial Nerve Monitoring under Neuromuscular Blockade  

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The characteristics of facial nerve electromyography at various levels of neuromuscular blockade are unclear. Partial blockade is well known to facilitate anesthetic safety and management. However, the use of neuromuscular blockage in many skull base procedures is avoided to allow intraoperative facial nerve monitoring.

Hester, T. Oma; Hasan, Akbar; Mcdonnell, Francis; Valentino, Joseph; Jones, Raleigh

1995-01-01

117

Computed tomography of skeletal muscles in neuromuscular disease  

Energy Technology Data Exchange (ETDEWEB)

CT-documentation of skeletal muscular lesions caused by neuromuscular diseases implies an essential contribution to conventional techniques in the macroscopic field. Size, distribution and degree of lesions as well as compensatory mechanisms are proved thereby. We report about the different effects on muscle appearance referring to 106 patients of our own experience in amyotrophic lateral sclerosis, spinal muscular atrophy, poliomyelitis, polyradiculitis, polyneuropathy as well as peripheral traumatic nerve lesions.

Rodiek, S.O.; Kuether, G.

1985-06-01

118

Computed tomography of skeletal muscles in neuromuscular disease  

International Nuclear Information System (INIS)

CT-documentation of skeletal muscular lesions caused by neuromuscular diseases implies an essential contribution to conventional techniques in the macroscopic field. Size, distribution and degree of lesions as well as compensatory mechanisms are proved thereby. We report about the different effects on muscle appearance referring to 106 patients of our own experience in amyotrophic lateral sclerosis, spinal muscular atrophy, poliomyelitis, polyradiculitis, polyneuropathy as well as peripheral traumatic nerve lesions. (orig.)

1985-06-01

119

Diagnostic immunohistochemistry in neuromuscular disorders.  

Science.gov (United States)

Most neuromuscular disorders display only non-specific myopathological features in routine histological preparations. However, a number of proteins, including sarcolemmal, sarcomeric, and nuclear proteins as well as enzymes with defects responsible for neuromuscular disorders, have been identified during the past two decades, allowing a more specific and firm diagnosis of muscle diseases. Identification of protein defects relies predominantly on immunohistochemical preparations and on Western blot analysis. While immunohistochemistry is very useful in identifying abnormal expression of primary protein abnormalities in recessive conditions, it is less helpful in detecting primary defects in dominantly inherited disorders. Abnormal immunohistochemical expression patterns can be confirmed by Western blot analysis which may also be informative in dominant disorders, although its role has yet to be established. Besides identification of specific protein defects, immunohistochemistry is also helpful in the differentiation of inflammatory myopathies by subtyping cellular infiltrates and demonstrating up-regulation of subtle immunological parameters such as cell adhesion molecules. The role of immunohistochemistry in denervating disorders, however, remains controversial in the absence of a reliable marker of muscle fibre denervation. Nevertheless, as well as the diagnostic value of immunocytochemical analysis it may also widen understanding of muscle fibre pathology as well as help in the development of therapeutic strategies. PMID:15656881

Tews, D S; Goebel, H H

2005-01-01

120

Musculoskeletal and neuromuscular interventions: a physical approach to cystic fibrosis.  

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Children with CF are living longer than ever before, and thus issues pertaining to quality of life rather than just longevity of life need to be addressed by the entire healthcare team. This article addressed the issues pertaining to the external support of the dysfunctional internal organs: the secondary musculoskeletal (postural) and neuromuscular control deficits that occur to the maturing child with CF. The research pointed towards starting PT interventions for these deficits during the p...

Massery, Mary

2005-01-01

 
 
 
 
121

Cardiovascular and neuromuscular effects of esmolol during induction of anesthesia.  

Science.gov (United States)

Sixteen subjects scheduled for surgical procedures under general anesthesia participated in an investigation of the effects of esmolol on the transient hypertension and tachycardia that was observed during endotracheal intubation and on the duration of succinylcholine-induced neuromuscular blockade. In eight subjects, infusion of esmolol was begun five minutes before induction of anesthesia and continued for 12 minutes after induction. In the remaining subjects, an equivalent volume of solvent (D5W) was infused for 12 minutes. Infusion of esmolol significantly attenuated the cardioacceleration observed during intubation without any significant effect on the pressor effects of the procedure. Esmolol delayed the recovery from succinylcholine-induced neuromuscular blockade by less than three minutes. The mechanism of this delay remains to be investigated, although such a delay does not have clinical significance. Esmolol-induced attenuation of the tachycardia seen during intubation may offer a protective effect on the myocardium, especially in elderly subjects and patients with coronary artery disease. PMID:2871054

Murthy, V S; Patel, K D; Elangovan, R G; Hwang, T F; Solochek, S M; Steck, J D; Laddu, A R

1986-01-01

122

Efectos del vendaje neuromuscular: una revisión bibliográfica / Neuromuscular dressing effects: a literature review / Efeitos neuromusculares de bandages: uma revisão da literatura  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese A kinesio taping é uma técnica que foi criada em 1979 por Dr. Kenzo Kase Estou procurando através dele que poderia gerar uma nova opção terapêutica para controlar a dor, melhorar o desempenho atlético e reduzir o impacto de distúrbios músculo-esqueléticos. Do Sydney 2000 Olympic Games, estatécnica c [...] omo uma alternativa terapêutica PTO e é composto de profissionais de saúde na área de reabilitação física e esporte. Alvo: Este artigo tem como objetivo identificar abordagens teóricas sobre oNeuromuscular curativo. Materiais e métodos: realizou hoje, para o qual realizou uma pesquisa bibliográficados bancos de dados, tais como como Proquest, Ovid, Cochraine, PEDro, Journal of Orthopedic and Sports Physical, Sciencedirect, Pubmed y Literatura Latinoamericana y del Caribe en Ciencias de la Salud (Lilacs). O documento propõe um esquemade contextualização do cenário atual do uso e efeitos de kinesio taping na gestão dasdiferentes patologias do sistema músculo-esquelético no esporte. Conclusões: conclui-se quemuitos profissionais de saúde atualmente, e tomar as vandaje neuromuscular uma boa opção terapêutica no tratamento de doenças que afetam o corpo humano é investigada e cada dia mais sobre o assunto, o que torna esses novos métodosterapêuticos para adquirir um valor científico e transcende o conhecimento. Abstract in spanish El vendaje neuromuscular es una técnica creada en 1979 por el doctor Kenzo Kase, quien buscó proponer una nueva opción terapéutica para controlar el dolor, mejorar el rendimiento deportivo y reducir el impacto de los trastornos musculo-esqueléticos. A partir de los Juegos Olímpicos de Sydney 2000 es [...] ta técnica empleada por los profesionales de la salud en el campo del deporte y la rehabilitación física tomó fuerza como alternativa terapéutica. Objetivo: identificar las aproximaciones teóricas sobre el vendaje neuromuscular realizadas en la actualidad. Materiales y métodos: se llevó a cabo una búsqueda bibliográfica en bases de datos como Proquest, Ovid, Cochraine, PEDro, Journal of Orthopedic and Sports Physical, Sciencedirect, Pubmed y Literatura Latinoamericana y del Caribe en Ciencias de la Salud (Lilacs). El esquema del artículo propone una contextualización del panorama actual del uso y los efectos del vendaje neuromuscular en el campo deportivo y en el manejo de diferentes patologías del sistema musculo-esquelético. Conclusiones: se concluye que actualmente muchos profesionales de la salud toman el vendaje neuromuscular como un buena opción terapéutica en el manejo de patologías que afectan el cuerpo humano, por lo cual cada día se investiga más acerca del tema, otorgando un valor científico a estos nuevos métodos. Abstract in english The kinesio taping is a technique that was created in 1979 by Doctor Kenzo Kase I'm looking through it that could generate a new therapeutic option to control pain, improve athletic performance and reduce the impact of musculoskeletal disorders. From the Sydney 2000 Olympic Games, this technique as [...] a therapeutic alternative PTO and is composed of health professionals in the field of sport and physical rehabilitation. Objetive: This article aims to identify theoretical approaches on the bandage neuromuscular. Material and methods: held today, for which conducted a literature search of databases such as como Proquest, Ovid, Cochraine, PEDro, Journal of Orthopedic and Sports Physical, Sciencedirect, Pubmed y Literatura Latinoamericana y del Caribe en Ciencias de la Salud (Lilacs). The paper proposes a scheme of contextualization of the current landscape of the use and effects of kinesio taping in the management of different pathologies of the musculo-skeletal system in sports. Conclusion: it is concluded that currently many health professionals, and take the neuromuscular bandage a good therapeutic option in the management of diseases affecting the human body is investigated and every day more about the subject,

Calero Saa, Pedro Antonio; Cañón Martínez, Gustavo Adolfo.

123

[Macro EMG in neuromuscular diseases].  

Science.gov (United States)

The aim of this study is the introducing of macro-emg method as electrophysiological test used in diagnosis of neuromuscular diseases. The macro motor unit potentials (macro MUPs) obtained by recording macroelectrode (modified single-fibre electrode) represents temporal and spatial summation of individual single fiber action potentials belonging to whole motor unit territory--so the uptake area is larger for macroelectrode than for the concentric electrode, commonly used in emg routine work, when central main complex is generated only from less than 15 muscle fibers [10, 12, 13]. Additional information obtained by macro-emg method is spatial organisation of muscle fibers within the motor unit, so-called fiber density (F.D) In our study macro-emg examinations were performed in 20 healthy subjects, aged 21-55, without signs and symptoms of neuromuscular disorders. Macro MUPs were recorded using special programme for macro-emg and performed on electromyograph Counterpoint. 37 muscles (20 BB and 17 RF) were examined, and median values of amplitude, area of macro MUPs and F.D. in healthy subjects of different age were analyzed. Mean values of median for amplitude and area of macro MUPs in BB and RF muscles show respectively--148 microV, 382 microV x ms, and 319 microV, 763 microV x ms. Parameters of macro MUPs obtained in healthy subjects were compared to results obtained in 10 patients with myopathy and lower motor neuron lesion. Our results have confirmed the value of macro-emg method for investigating of the pathophysiological changes in motor units in neurogenic disorders, in myopathy the study should be continued. PMID:10463226

Szmidt-Sa?kowska, E; Rowi?ska-Marci?ska, K; Kope?, A; Wawro, A

1998-01-01

124

Packet Loss Control Using STLCC Mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available Presently the Internet accommodates simultaneous audio, video, and data traffic. This requires the Internet to guarantee the packet loss which at its turn depends very much on congestion control. A series of protocols have been introduced to supplement the insufficient TCP mechanism controlling the network congestion. CSFQ was designed as an open-loop controller to provide the fair best effort service for supervising the per-flow bandwidth consumption and has become helpless when the P2P flows started to dominate the traffic of the Internet. Token-Based Congestion Control (TBCC is based on a closed-loop congestion control principle, which restricts token resources consumed by an end-user and provides the fair best effort service. As Self-Verifying CSFQ and Re-feedback, it experiences a heavy load by policing inter domain traffic for lack of trust.In this paper, Stable Token-Limited Congestion Control (STLCC is introduced as new protocols which appends interdomain congestion control to TBCC and make the congestion control system to be stable. STLCC is able to shape output and input traffic at the inter-domain link.STLCC produces a congestion index pushes the packet loss to the network edge and improves the network performance. Finally, the simple version of STLCC is introduced. This version is deployable in the Internet without any IP protocols modifications and preserves also the packet datagram.

G. Srikanth Reddy

2013-09-01

125

Optimal Control of Underactuated Nonholonomic Mechanical Systems  

CERN Document Server

In this paper we use an affine connection formulation to study an optimal control problem for a class of nonholonomic, under-actuated mechanical systems. In particular, we aim at minimizing the norm-squared of the control input to move the system from an initial to a terminal state. We consider systems evolving on general manifolds. The class of nonholonomic systems we study in this paper includes, in particular, wheeled-type vehicles, which are important for many robotic locomotion systems. The two special aspects of this optimal control problem are the nonholonomic constraints and under-actuation. Nonholonomic constraints restrict the evolution of the system to a distribution on the manifold. The nonholonomic connection is used to express the constrained equations of motion. Furthermore, it is used to take variations of the cost functional. Many robotic systems are under-actuated since control inputs are usually applied through the robot's internal configuration space only. While we do not consider symmetri...

Hussein, I I; Hussein, Islam I.; Bloch, Anthony M.

2005-01-01

126

Common pathways of autoimmune inflammatory myopathies and genetic neuromuscular disorders.  

Science.gov (United States)

It has been shown that many hereditary motor neuron diseases are caused by mutation of RNA processing enzymes. Survival of motor neuron 1 (SMN1) is well-known as a causative gene for spinal muscular atrophy (SMA) and mutations of glycyl- and tyrosyl-tRNA synthetases are identified as a cause of distal SMA and Charcot-Marie-Tooth disease. Why and how the dysfunction of these ubiquitously expressed genes involved in RNA processing can cause a specific neurological disorder is not well understood. Interestingly, SMN complex has been identified recently as a new target of autoantibodies in polymyositis (PM). Autoantibodies in systemic rheumatic diseases are clinically useful biomarkers associated with a particular diagnosis, subset of a disease, or certain clinical characteristics. Many autoantibodies produced in patients with polymyositis/dermatomyositis (PM/DM) target RNA-protein complexes such as aminoacyl tRNA synthetases. It is interesting to note these same RNA-protein complexes recognized by autoantibodies in PM/DM are also responsible for genetic neuromuscular disease. Certain RNA-protein complexes are also targets of autoantibodies in paraneoplastic neurological disorders. Thus, there are several interesting associations between RNA-processing enzymes and neuromuscular disorders. Although pathogenetic roles of autoantibodies to intracellular antigens are generally considered unlikely, understanding the mechanisms of antigen selection in a particular disease and specific neurological symptoms caused by disruption of ubiquitous RNA-processing enzyme may help identify a common path in genetic neuromuscular disorders and autoimmunity in inflammatory myopathies. PMID:22083460

Satoh, Minoru; Ceribelli, Angela; Chan, Edward K L

2012-02-01

127

La monitorización neuromuscular y su importancia en el uso de los bloqueantes neuromusculares Neuromuscular monitoring and its importance in neuromuscular blockade  

Directory of Open Access Journals (Sweden)

Full Text Available Introducción: La necesidad por incorporar nuevas guías o estrategias en la buena práctica de uso de los bloqueantes neuromusculares no es un hecho de obligado cumplimento en la actualidad dentro de la anestesiología. Solo existen recomendaciones de actuación con el propósito de convencer que la monitorización neuromuscular es una herramienta muy útil para el buen uso racional de los bloqueantes neuromusculares. Metodología: Las complicaciones surgen, y la parálisis residual es un evento destacado. Por esta razón, los autores propugnamos que la monitorización del bloqueo neuromuscular puede ser un factor determinante en la mejora del cuidado de nuestros pacientes, disminuyendo tanto la morbilidad como la mortalidad. Esta revisión y su metodología en base a la experiencia de los autores solo pretende exponer de forma sencilla conocimientos que consideramos básicos para su utilización sistemática en nuestra práctica rutinaria. Resultados y conclusiones: Esta actualización describe los principios fundamentales de los métodos que disponemos en la actualidad, priorizando las medidas cuantitativas de registro. Y también demuestra el diferente comportamiento de la musculatura al efecto de los bloqueantes neuromusculares, fundamentos relevantes que es preciso conocer. La monitorización neuromuscular es una práctica que debe utilizarse siempre que un bloqueo neuromuscular sea necesario. Somos conscientes que generar una recomendación explícita es difícil. Pero nuestro entusiasmo parte del beneficio de una experiencia personal con estos métodos que son conocidos desde antiguo. Debido a la potencial morbilidad asociada con bloqueos neuromusculares residuales, la monitorización perioperatoria de la función neuromuscular es esencial.Introduction: The incorporation of new guidelines or strategies as part of good practices in the use of muscle relaxants is not a requirement at present in the practice of anesthesia. There are only action recommendations designed to persuade clinicians of the fact that neuromuscular monitoring is a very useful tool for the rational use of muscle relaxants. Methodology:Complications occur, and residual paralysis is a significant event. For this reason, the authors advocate that monitoring neuromuscular block may be a determining factor in improving patient care and reducing morbidity and mortality. This review and its methodology based on the experience of the authors is designed to present, in a simple format, the knowledge that considered fundamental for the systematic use of neuromuscular monitoring in every day practice. Results and conclusions: This update describes the fundamental principles of the methods available at present, emphasizing quantitative recording measurements. It then describes the different ways in which muscles respond to the effect of neuromuscular blockade, as these are critical fundamental principles that have to be known. Neuromuscular monitoring is a practice that should be implemented every time a neuromuscular block is required. We are aware of the difficulty of generating an explicit recommendation, but our enthusiasm is derived from the benefits we have personally experienced when applying these methods that have been known for a long time. Due to the potential morbidity associated with residual muscle relaxation, perioperative monitoring of neuromuscular function is essential.

Joaquín Fabregat López

2012-12-01

128

La monitorización neuromuscular y su importancia en el uso de los bloqueantes neuromusculares / Neuromuscular monitoring and its importance in neuromuscular blockade  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Introducción: La necesidad por incorporar nuevas guías o estrategias en la buena práctica de uso de los bloqueantes neuromusculares no es un hecho de obligado cumplimento en la actualidad dentro de la anestesiología. Solo existen recomendaciones de actuación con el propósito de convencer que la moni [...] torización neuromuscular es una herramienta muy útil para el buen uso racional de los bloqueantes neuromusculares. Metodología: Las complicaciones surgen, y la parálisis residual es un evento destacado. Por esta razón, los autores propugnamos que la monitorización del bloqueo neuromuscular puede ser un factor determinante en la mejora del cuidado de nuestros pacientes, disminuyendo tanto la morbilidad como la mortalidad. Esta revisión y su metodología en base a la experiencia de los autores solo pretende exponer de forma sencilla conocimientos que consideramos básicos para su utilización sistemática en nuestra práctica rutinaria. Resultados y conclusiones: Esta actualización describe los principios fundamentales de los métodos que disponemos en la actualidad, priorizando las medidas cuantitativas de registro. Y también demuestra el diferente comportamiento de la musculatura al efecto de los bloqueantes neuromusculares, fundamentos relevantes que es preciso conocer. La monitorización neuromuscular es una práctica que debe utilizarse siempre que un bloqueo neuromuscular sea necesario. Somos conscientes que generar una recomendación explícita es difícil. Pero nuestro entusiasmo parte del beneficio de una experiencia personal con estos métodos que son conocidos desde antiguo. Debido a la potencial morbilidad asociada con bloqueos neuromusculares residuales, la monitorización perioperatoria de la función neuromuscular es esencial. Abstract in english Introduction: The incorporation of new guidelines or strategies as part of good practices in the use of muscle relaxants is not a requirement at present in the practice of anesthesia. There are only action recommendations designed to persuade clinicians of the fact that neuromuscular monitoring is a [...] very useful tool for the rational use of muscle relaxants. Methodology:Complications occur, and residual paralysis is a significant event. For this reason, the authors advocate that monitoring neuromuscular block may be a determining factor in improving patient care and reducing morbidity and mortality. This review and its methodology based on the experience of the authors is designed to present, in a simple format, the knowledge that considered fundamental for the systematic use of neuromuscular monitoring in every day practice. Results and conclusions: This update describes the fundamental principles of the methods available at present, emphasizing quantitative recording measurements. It then describes the different ways in which muscles respond to the effect of neuromuscular blockade, as these are critical fundamental principles that have to be known. Neuromuscular monitoring is a practice that should be implemented every time a neuromuscular block is required. We are aware of the difficulty of generating an explicit recommendation, but our enthusiasm is derived from the benefits we have personally experienced when applying these methods that have been known for a long time. Due to the potential morbidity associated with residual muscle relaxation, perioperative monitoring of neuromuscular function is essential.

Fabregat López, Joaquín; Candia Arana, César Augusto; Castillo Monzón, Caridad Greta.

129

Autoimmune disorders of the neuromuscular junction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The neuromuscular junction (NMJ) is a specialized synapse with a complex structural and functional organization. It is a target for a variety of immunological disorders and these diseases usually respond well to immunotherapies. The understanding of the immunological basis of myasthenia gravis, the most common neuromuscular junction disorder, has improved in the recent years. Most patients have antibodies to the acetylcholine receptor (AChR), but around 10% have AChR antibodies that ar...

Vincent Angela

2008-01-01

130

Neuromuscular Electrical Stimulation for Skeletal Muscle Function  

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Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical ...

Doucet, Barbara M.; Lam, Amy; Griffin, Lisa

2012-01-01

131

Stance control knee mechanism for lower-limb support in hybrid neuroprosthesis  

Directory of Open Access Journals (Sweden)

Full Text Available A hydraulic stance control knee mechanism (SCKM was developed to fully support the knee against flexion during stance and allow uninhibited motion during swing for individuals with paraplegia using functional neuromuscular stimulation (FNS for gait assistance. The SCKM was optimized for maximum locking torque for body-weight support and minimum resistance when allowing for free knee motion. Ipsilateral and contralateral position and force feedback were used to control the SCKM. Through bench and nondisabled testing, the SCKM was shown to be capable of supporting up to 70 N-m, require no more than 13% of the torque achievable with FNS to facilitate free motion, and responsively and repeatedly unlock under an applied flexion knee torque of up to 49 N-m. Preliminary tests of the SCKM with an individual with paraplegia demonstrated that it could support the body and maintain knee extension during stance without the stimulation of the knee extensor muscles. This was achieved without adversely affecting gait, and knee stability was comparable to gait assisted by knee extensor stimulation during stance.

Curtis S. To, PhD

2011-08-01

132

Automatic control mechanism for nuclear reactor scram  

International Nuclear Information System (INIS)

A mechanism is described in which the mean temperature of the coolant on leaving the core of a liquid cooled nuclear reactor is detected and which allows a poison to fall quickly into the core of the reactor when a critical temperature is reached. The reactor comprises a safety pipe located in the core and rising above it, a vertical flow path for the reactor coolant passing through the pipe and a poison bundle absorbing the neutrons, retained by a supporting system. Several fuel rods are located in the flow path of the coolant, a temperature sensitive control device is located in the flow path near the upper end of the fuel rods, a retaining device is fitted between the poison bundle support system and the control system so as to release the poison bundle when the control system makes a preset movement

1977-06-10

133

Ação neuro-muscular do veneno crotálico: dados preliminares Neuromuscular action of crotalid venom: preliminar data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Estudamos 6 pacientes, 2 cães e um coelho com intoxicação crotálica. Avaliamos a condução nervosa periférica sensitiva e motora, a transmissão neuromuscular e eletromiografias. As biópsias de músculo foram processadas por histoquímica. Os 6 pacientes apresentaram mononeuropatia sensitiva no nervo periférico adjacente ao local da inoculação do veneno e encontramos evidências histoquímicas de miopatia mitocondrial. Os defeitos da transmissão neuromuscular foram mínimos. A maio...

1996-01-01

134

Papel da vitamina D na função neuro-muscular Role of vitamin D in the neuro-muscular function  

Directory of Open Access Journals (Sweden)

Full Text Available A vitamina D, através de suas ações no intestino, rim, osso e glândulas paratiróides, é um hormônio fundamental para a homeostase do cálcio e para o desenvolvimento de um esqueleto saudável. Além disso, receptores deste hormônio podem ser encontrados em quase todos os tecidos do organismo e outras ações não relacionadas ao metabolismo mineral têm sido imputadas a ele. Na célula muscular esquelética, a vitamina D atua através do mecanismo clássico de ligação a um receptor nuclear e também através da ligação a um receptor de membrana, realizando ações que envolvem o transporte de cálcio, a síntese protéica e a velocidade de contração muscular. Clinicamente, a deficiência de vitamina D, que é bastante comum em idosos, inclusive em nosso país, tem sido relacionada a um aumento da incidência de quedas, a uma diminuição da força muscular e a uma deterioração do equilíbrio, avaliada pela oscilação do corpo na postura ereta. Por outro lado, tem sido demonstrado que a suplementação associada de cálcio e vitamina D em idosos deficientes contribui para melhoria destes aspectos da função neuro-muscular. Nesta revisão, serão discutidos os mecanismos conhecidos envolvidos na associação entre vitamina D e função neuro-muscular, e também a suplementação de vitamina D e cálcio na prevenção de fraturas osteoporóticas não-vertebrais sob a perspectiva dos efeitos neuro-musculares.Through its action in the kidney, intestines, bone and parathyroid glands vitamin D is a major regulator of calcium homeostasis and for the development of a healthy skeleton. Moreover, receptors for this hormone are present in almost all body tissues and other actions which are not related to the mineral metabolism have been imputed to it. In the skeletal muscle cell, vitamin D acts through the classic mechanism of binding to a nuclear receptor and also by binding to a membrane receptor, carrying out actions that involve calcium transport, protein synthesis and kinetics of muscle contraction. Clinically, vitamin D deficiency, which is very common among the elderly, including the ones in our country, has been related to an increase in the incidence of falls, as well as the reduction of muscle strength and deterioration of body sway, evaluated by the oscillation of the body in the erect position. On the other hand, it has been demonstrated that supplementation of calcium associated to vitamin D in deficient elderly contributes to the improvement of these aspects of the neuro-muscular function. In this review, the mechanisms involved in the association between vitamin D and neuro-muscular function will be discussed, as well as the supplementation of vitamin D and calcium to prevent non-vertebral osteoporotic fractures under the perspective of the neuro-muscular effects.

Márcia A. Carneiro Pedrosa

2005-08-01

135

Mobility-assistive technology in progressive neuromuscular disease.  

Science.gov (United States)

Mobility-assistive technologies allow patients with neuromuscular disease to interact with peers and the community. In children, they also serve to facilitate development. Lack of access to appropriate assistive technology, especially in regards to mobility, can have adverse developmental consequences. There are multiple options for mobility devices and methods for their control. These devices can be integrated with other electronics to facilitate the control of a variety of devices in the environment. The clinician should assess which devices are best based on the patient's, caregivers', and medical team's goals. PMID:23137743

Lin, Wendy; Pierce, Aaron; Skalsky, Andrew J; McDonald, Craig M

2012-11-01

136

Splicing therapy for neuromuscular disease?  

Science.gov (United States)

Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) are two of the most common inherited neuromuscular diseases in humans. Both conditions are fatal and no clinically available treatments are able to significantly alter disease course in either case. However, by manipulation of pre-mRNA splicing using antisense oligonucleotides, defective transcripts from the DMD gene and from the SMN2 gene in SMA can be modified to once again produce protein and restore function. A large number of in vitro and in vivo studies have validated the applicability of this approach and an increasing number of preliminary clinical trials have either been completed or are under way. Several different oligonucleotide chemistries can be used for this purpose and various strategies are being developed to facilitate increased delivery efficiency and prolonged therapeutic effect. As these novel therapeutic compounds start to enter the clinical arena, attention must also be drawn to the question of how best to facilitate the clinical development of such personalised genetic therapies and how best to implement their provision.

Douglas, Andrew G.L.; Wood, Matthew J.A.

2013-01-01

137

Passive cooling of control rod drive mechanisms  

International Nuclear Information System (INIS)

A method and apparatus are provided for passively cooling the control rod drive mechanisms (CRDMs) in the reactor vessel of a nuclear power plant. Passive cooling is achieved by dispersing a plurality of chimneys within the CRDM array in positions where a control rod is not required. The chimneys induce convective air currents which cause ambient air from within the containment to flow over the CRDM coils. The air heated by the coils is guided into inlets in the chimneys by baffles. The chimney is insulated and extends through the seismic support platform and missile shield disposed above the closure head. A collar of adjustable height mates with plate elements formed at the distal end of the CRDM pressure housings by an interlocking arrangement so that the seismic support platform provides lateral restraint for the chimneys. (Author)

1991-01-17

138

Effects of neuromuscular electrostimulation in patients with heart failure admitted to ward  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Neuromuscular electrostimulation has become a promising issue in cardiovascular rehabilitation. However there are few articles published in the literature regarding neuromuscular electrostimulation in patients with heart failure during hospital stay. Methods This is a randomized controlled pilot trial that aimed to investigate the effect of neuromuscular electrostimulation in the walked distance by the six-minute walking test in 30 patients admitted to ward for heart failure treatment in a tertiary cardiology hospital. Patients in the intervention group performed a conventional rehabilitation and neuromuscular electrostimulation. Patients underwent 60 minutes of electrostimulation (wave frequency was 20 Hz, pulse duration of 20 us two times a day for consecutive days until hospital discharge. Results The walked distance in the six-minute walking test improved 75% in the electrostimulation group (from 379.7 ± 43.5 to 372.9 ± 46.9 meters to controls and from 372.9 ± 62.4 to 500 ± 68 meters to electrostimulation, p Conclusion The neuromuscular electrostimulation group showed greater improvement in the walked distance in the six-minute walking test in patients admitted to ward for compensation of heart failure.

de Araújo Carlos José Soares

2012-11-01

139

Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by Volitional Activation of the Same Muscle : Adaptive Removal of the Muscle Response from the Recorded EMG-Signal  

DEFF Research Database (Denmark)

In order to use the volitional electromyography (EMG) as a control signal for the stimulation of the same muscle, it is necessary to eliminate the stimulation artifacts and the muscle responses caused by the stimulation. The stimulation artifacts, caused by the electric field in skin and tissue generated by the stimulation current, are relatively easy to eliminate by shutting down the EMG-amplifier at the onset of the stimulation pulses. The muscle response is a nonstationary signal, therefore, an adaptive linear prediction filter is proposed. The filter is implemented and for three filter lengths tested on both simulated and real data. The filter performance is compared with a conventional fixed comb filter. The simulations indicate that the adaptive filter is relatively insensitive to variations in amplitude of the muscle responses, and for all filter lengths produces a good filtering. For variations in shape of the muscle responses and for real data, an increased filter performance can be achieved by increasing the filter length. Using a filter length of up to seven stimulation periods, it is possible to reduce real muscle responses to a level comparable with the background noise. Using the shut-down circuit and the adaptive filter both the stimulation artifacts and the muscle responses can be effectively eliminated from the EMG signal from a stimulated muscle. It is therefore possible to extract the volitional EMG from a partly paralyzed muscle and use it for controlling the stimulation of the same muscle

Sennels, Søren; Andersen, Ole Trier

1997-01-01

140

Control of mechanical properties by monitoring microstructure  

Energy Technology Data Exchange (ETDEWEB)

The microstructure monitor involves a method to compute mechanical properties of hot rolled steel from process data and the chemical composition of the steel. The underlying microstructure model monitors grain size and degree of recrystallization at each point in the mill. The physical model is complemented by an artificial neural network for the calculation of mechanical properties. The evolution of microstructure during finishing and cooling is described in the model. Processes such as static and dynamic recrystallization, grain growth and austenite-ferrite transformation are all part of the calculation. Results from hot rolling mills are presented. A comparison of measured and calculated values for the tensile strength of low-carbon manganese and niobium microalloyed steels illustrate the accuracy of the microstructure monitor. Several major advantages result from the on-line application of the monitor system. In addition to the facility of quick release of strips after rolling and the saving of costs involved in quality control measurements, even process parameters could be changed to achieve desired mechanical properties of the product. (orig.)

Loeffler, H.U.; Doell, R.; Lang, B.; Soergel, G. [Siemens AG (Germany); Holtheuer, U. [Hoesch Hohenlimburg GmbH (Germany); Zouhar, G. [Technical Univ. of Dresden (Germany)

2000-07-01

 
 
 
 
141

Changes of trabecular bone under control of biologically mechanical mechanism  

Science.gov (United States)

In this study, a biological process of bone remodeling was considered as a closed loop feedback control system, which enables bone to optimize and renew itself over a lifetime. A novel idea of combining strain-adaptive and damage-induced remodeling algorithms at Basic Multicellular Unit (BMU) level was introduced. In order to make the outcomes get closer to clinical observation, the stochastic occurrence of microdamage was involved and a hypothesis that remodeling activation probability is related to the value of damage rate was assumed. Integrated with Finite Element Analysis (FEA), the changes of trabecular bone in morphology and material properties were simulated in the course of five years. The results suggest that deterioration and anisotropy of trabecluar bone are inevitable with natural aging, and that compression rather than tension can be applied to strengthen the ability of resistance to fracture. This investigation helps to gain more insight the mechanism of bone loss and identify improved treatment and prevention for osteoporosis or stress fracture.

Wang, C.; Zhang, C. Q.; Dong, X.; Wu, H.

2008-11-01

142

Employment profiles in neuromuscular diseases.  

Science.gov (United States)

Consumer and rehabilitation provider factors that might limit employment opportunities for 154 individuals with six slowly progressive neuromuscular diseases (NMD) were investigated. The NMDs were spinal muscular atrophy (SMA), hereditary motor sensory neuropathy (HMSN), Becker's muscular dystrophy (BMD), facioscapulohumeral muscular dystrophy (FSHD), myotonic muscular dystrophy (MMD), and limb-girdle syndrome (LGS). Forty percent were employed in the competitive labor market at the time of the study, 50% had been employed in the past, and 10% had never been employed. The major consumer barrier to employment was education. Other important factors were type of occupation, intellectual capacity, psychosocial adjustment, and the belief by most individuals that their physical disability was the only or major barrier to obtaining a job. Psychological characteristics were associated with level of unemployment. However, physical impairment and disability were not associated with level of unemployment. There also were differences among the types of NMDs. Compared with the SMA, HMSN, BMD, and FSHD groups, the MMD and LGS groups had significantly higher levels of unemployment, lower educational levels, and fewer employed professional, management, and technical workers. Nonphysical impairment factors such as a low percentage of college graduates, impaired intellectual function in some individuals, and poor psychological adjustment were correlated with higher unemployment levels in the MMD group. Unemployment in the LGS group was correlated with a failure to complete high school. Major provider barriers to employment were the low level of referrals to Department of Rehabilitation by physicians and the low percentage of acceptance into the State Department of Rehabilitation. The low rate of acceptance was primarily attributable to the low number of referrals compounded by a lack of counselor experience with individuals with NMD. Both consumer and provider barriers may contribute to the lack of interest in obtaining a job. PMID:9036908

Fowler, W M; Abresch, R T; Koch, T R; Brewer, M L; Bowden, R K; Wanlass, R L

1997-01-01

143

Bonfils Fiberscope: Intubating Conditions and Hemodynamic Changes without Neuromuscular Blockade  

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Full Text Available To compare intubating conditions and hemodynamic changes between Bonfils Intubation Fiberscope and Macintosh laryngoscopy without administering neuromuscular blocking drugs (NMBDs. METHODS: In this randomized controlled trial,80 male and female patients, scheduled for elective surgery, aged 15 to 60 years, ASA class II or I, non-obese, non smokers, without anticipated difficult intubation; were randomly allocated into two groups of 40: Bonfils and Macintosh. Following adequate hydration and preoxygenation, midazolam 0.03 mg.kg-1 was administered, followed by intravenous alfentanil 20 µg.kg-1, lidocaine 1.0 mg.kg-1, and propofol 2 mg.kg-1 sequentially. Trachea was then intubated using Bonfils Intubation Fiberscope in the Bonfils group and conventional Macintosh laryngoscopy in the Macintosh group. Intubating condition, mean arterial blood pressure, heart rate, pulse oximetry, and success rate were measured. RESULTS: Clinically acceptable intubating condition scores did not differ significantly between the groups (P=0.465. Compared to the baseline values, heart rate rose significantly after intubation only in the Macintosh group (P<0.001. Although mean arterial blood pressure increased immediately after intubation in the Macintosh group (P=0.022, its post-intubation values were significantly less than baseline in both groups (P<0.001. Intubation time took much longer in the Bonfils group (40 s than the Macintosh group (11 s, P<0.001. In the absence of NMBDs, Bonfils Intubation Fiberscope compares well with Macintosh laryngoscopy in terms of success rate and intubating conditions, but with less mechanical stress and hemodynamic compromise and longer intubation time.

Atabak Najafi

2011-04-01

144

Diagnóstico electromiográfico de las enfermedades neuromusculares  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se revisó una amplia bibliografía acerca del estado actual del diagnóstico electromiográfico de las enfermedades neuromusculares, sus logros, avances y limitaciones, en la búsqueda de un diagnóstico electrofisiológico funcional más sensible y específico. La electromiografía contemporánea se encuentr [...] a en una etapa de revisiones de sus objetivos y aplicaciones, surgen nuevos métodos y conceptos que desplazan a los anteriores ya arcaicos; es indiscutiblemente una herramienta imprescindible en el estudio de las enfermedades neuromusculares. Con el objetivo de dar a conocer estos aspectos a los especialistas de otras ramas de la medicina se realizó este estudio. Abstract in english Electromyographic diagnosis of neuromuscular diseases [...

Álvarez Fiallo, Roger; Santos Anzorandia, Carlos; Medina Herrera, Esther.

145

Naturally occurring plant polyphenols as potential therapies for inherited neuromuscular diseases.  

Science.gov (United States)

There are several lines of laboratory-based evidence emerging to suggest that purified polyphenol compounds such as resveratrol, found naturally in red grapes, epigallocatechin galate from green tea and curcumin from turmeric, might be useful for the treatment of various inherited neuromuscular diseases, including spinal muscular atrophy, Duchenne muscular dystrophy and Charcot-Marie-Tooth disease. Here, we critically examine the scientific evidence related to the known molecular effects that these polyphenols have on different models of inherited neuromuscular disease, with particular attention to problems with the validity of in vitro evidence. We also present proteomic evidence that polyphenols have in vitro effects on cells related to metal ion chelation in cell-culture media. Although their precise mechanisms of action remain somewhat elusive, polyphenols could be an attractive approach to therapy for inherited neuromuscular disease, especially since they may be safer to use on young children, compared with some of the other drug candidates. PMID:24215348

Fuller, Heidi R; Humphrey, Emma L; Morris, Glenn E

2013-11-01

146

Discrete Mechanics and Optimal Control: an Analysis  

CERN Document Server

The optimal control of a mechanical system is of crucial importance in many realms. Typical examples are the determination of a time-minimal path in vehicle dynamics, a minimal energy trajectory in space mission design, or optimal motion sequences in robotics and biomechanics. In most cases, some sort of discretization of the original, infinite-dimensional optimization problem has to be performed in order to make the problem amenable to computations. The approach proposed in this paper is to directly discretize the variational description of the system's motion. The resulting optimization algorithm lets the discrete solution directly inherit characteristic structural properties from the continuous one like symmetries and integrals of the motion. We show that the DMOC approach is equivalent to a finite difference discretization of Hamilton's equations by a symplectic partitioned Runge-Kutta scheme and employ this fact in order to give a proof of convergence. The numerical performance of DMOC and its relationsh...

Ober-Bloebaum, S; Marsden, J E

2008-01-01

147

Neuromuscular electrical stimulation cycling exercise for persons with advanced multiple sclerosis.  

Science.gov (United States)

Objective: To investigate the feasibility of neuromuscular electrical stimulation cycling modified to suit persons with advanced multiple sclerosis. Subjects: Eight women with secondary progressive multiple sclerosis. Methods: Subjects participated in an 18-session (40 min) neuromuscular electrical stimulation cycling program. A pedaling cadence of 10 rev•min-1 was employed and stimulation intensity was not modulated to control cadence, but increased gradually throughout each session. The outcomes included the stimulation intensity tolerated, thigh circumference changes, and power output and cardiorespiratory response during cycling. Participants were interviewed about perceived benefits of the treatment including changes in transfer ability. Results: Seven participants (Expanded Disability Status Scale 6.5-8.5) (mean 7.4 (standard deviation 0.7)) completed the training program over an average of 10 weeks. Greater stimulation intensities were tolerated than previously reported for persons with multiple sclerosis. Increases were found in thigh volume. Perceived benefits included improvements in transfer ability, leg circulation, spasticity and strength. Conclusion: Modifying neuromuscular electrical stimulation cycling allowed persons with advanced multiple sclerosis to tolerate greater stimulation intensities and exercise their muscles more intensely than previous studies. The benefits reported, which were solely due to neuromuscular electrical stimulation cycling, demonstrate that persons with preserved sensation and muscle paralysis/paresis might benefit from neuromuscular electrical stimulation exercise when it is adjusted appropriately. PMID:24763902

Fornusek, Ché; Hoang, Phu

2014-06-25

148

Neuromuscular patterns and the origin of trophic specialization in fishes.  

Science.gov (United States)

The pattern of muscle electrical activity in the pharyngeal muscles of the mollusc-eating sunfish Lepomis microlophus is highly specialized in comparison with the pattern displayed by most other members of the sunfish family and does not change when different prey are eaten. The closest genealogical relative of this species has the specialized muscle activity pattern for crushing prey when it feeds on snails but uses the primitive sequence of muscle activity during swallowing of other prey. The ability of species that crush snails to use molluscan prey effectively is due primarily to the evolutionary transformation of the neuromuscular program controlling the trophic apparatus. PMID:6828853

Lauder, G V

1983-03-11

149

Research highlights of partial neuromuscular disorders  

Directory of Open Access Journals (Sweden)

Full Text Available In order to understand the latest progression on neuromuscular disorders for clinicians, this review screened and systemized the papers on neuromuscular disorders which were collected by PubMed from January 2013 to February 2014. This review also introduced the clinical diagnosis and treatment hightlights on glycogen storage disease type ? (GSD ?, Duchenne muscular dystrophy (DMD, amyotrophic lateral sclerosis (ALS and spinal muscular atrophy (SMA. The important references will be useful for clinicians. doi: 10.3969/j.issn.1672-6731.2014.05.004

Cheng ZHANG

2014-05-01

150

The timing of impulse activity shapes the process of synaptic competition at the neuromuscular junction.  

Science.gov (United States)

The development of neuromuscular junctions exhibits profound remodeling that brings from an immature state characterized by multiple motoneuronal inputs per muscle fiber, to a mature mononeuronal innervation. This striking elimination process occurs both perinatally and during adult reinnervation, and is also widely present in the developing CNS. The accelerating influence of the amount of impulse activity on this process, has been shown by various studies, but a more subtle role of the time correlation of action potential firing in the competing inputs, has also been suggested. Here we explore the latter influence using a rat adult model of neuromuscular junction formation, that is reinnervation following a motor nerve crush. This shares all important features with perinatal development, especially the strict juxtaposition of the competing inputs. In fact the regenerating axons converge on a single cluster of postsynaptic receptors, that is the original endplate of each muscle fiber. This focus on the spatial aspect of competition between nerve endings was missing in our previous experiments employing a similar paradigm. We impose a chronic synchronous firing to the competing terminals, by in vivo electrical stimulation of their axons distal to a sciatic nerve conduction block. Control preparations, with similar post-crush reinnervation, are left with their natural impulse activity unperturbed. We find that the experimental muscles display a prolonged duration of polyneuronal innervation with respect to controls, indicating that hebbian mechanisms participate in the synapse elimination process. Another aspect dealt with in our study is the genuine nature of the polyneuronal innervation occurring during adult muscle reinnervation, because it is supported by both confocal microscopy and by appropriate electrophysiological tests that exclude electrical coupling of myofibers by gap junctions. PMID:20132871

Favero, M; Buffelli, M; Cangiano, A; Busetto, G

2010-05-01

151

Control mechanisms for a nonlinear model of international relations  

Energy Technology Data Exchange (ETDEWEB)

Some issues of control in complex dynamical systems are considered. The authors discuss two control mechanisms, namely: a short range, reactive control based on the chaos control idea and a long-term strategic control based on an optimal control algorithm. They apply these control ideas to simple examples in a discrete nonlinear model of a multi-nation arms race.

Pentek, A.; Kadtke, J. [Univ. of California, San Diego, La Jolla, CA (United States). Inst. for Pure and Applied Physical Sciences; Lenhart, S. [Univ. of Tennessee, Knoxville, TN (United States). Mathematics Dept.; Protopopescu, V. [Oak Ridge National Lab., TN (United States). Computer Science and Mathematics Div.

1997-07-15

152

O uso de bloqueadores neuromusculares no Brasil / Neuromuscular blockers in Brazil / El uso de bloqueadores neuromusculares en Brasil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese JUSTIFICATIVA E OBJETIVOS: Dados estatísticos referentes ao uso de bloqueadores neuromusculares no Brasil são desconhecidos. Este trabalho se propõe a análise estatística desse tópico. MÉTODO: Foram compiladas 831 respostas de um questionário preenchido em parte por anestesiologistas presentes ao 48 [...] º Congresso Brasileiro de Anestesiologia em Recife, 2001 e em parte via Internet, por anestesiologistas cujos endereços eletrônicos constam na página da Sociedade Brasileira de Anestesiologia (www.sba.com.br). Foram analisados os seguintes dados: tempo de contato com a especialidade, região onde atuam os anestesiologistas, uso de bloqueadores neuromusculares (BNM) em ordem de preferência, indicações do uso de succinilcolina, uso do monitor da transmissão neuromuscular, critérios para se considerar o paciente descurarizado, uso de neostigmina, forma de administração dos BNM e descrição de complicações observadas. RESULTADOS: A maioria dos anestesiologistas em questão exerce a profissão há mais de 11 anos e o maior número de respostas foi proveniente da região sudeste do Brasil. O BNM mais empregado é o atracúrio, seguido de pancurônio e succinilcolina. A succinilcolina é mais empregada na indução rápida e em crianças (80% e 25% respectivamente). Monitores da transmissão neuromuscular, 53% dos anestesiologistas nunca usam, e como critério de recuperação, 92% consideram o paciente descurarizado mediante sinais clínicos. Em 45% das vezes os profissionais empregam a neostigmina de forma rotineira, e 94% administra os BNM sob forma de bolus. Cerca de 30% registra ter havido complicação decorrente do uso de BNM. As complicações mais apontadas foram o bloqueio prolongado, o broncoespasmo grave e a curarização residual. CONCLUSÕES: O atracúrio é o bloqueador neuromuscular mais empregado no Brasil, há percentual alto de uso da succinilcolina em situações não emergenciais, o uso de monitores da transmissão neuromuscular é raro, e, como um corolário, um percentual significativo de uso de critérios eminentemente clínicos para considerar o paciente descurarizado. Registrou-se que, cerca de 30% dos anestesiologistas teve algum tipo de complicação decorrente do uso desses fármacos. Abstract in spanish JUSTIFICATIVA Y OBJETIVOS: Dados estadísticos referentes al uso de bloqueadores neuromusculares en Brasil son desconocidos. Este trabajo se propone el análisis estadístico de ese tópico. MÉTODO: Fueron compiladas 831 respuestas de un cuestionario llenado en parte por anestesiologistas presentes al 4 [...] 8º Congreso Brasileño de Anestesiologia en la ciudad de Recife, 2001 y en parte vía Internet, por anestesiologistas cuyas direcciones electrónicas constan en la página de la Sociedad Brasileña de Anestesiologia (www.sba.com.br). Fueron analizados los siguientes datos: tiempo de contacto con la especialidad, región donde actúan los anestesiologistas, uso de bloqueadores neuromusculares (BNM) en orden de preferencia, indicaciones del uso de succinilcolina, uso del monitor de transmisión neuromuscular, criterios para considerar el paciente descurarizado, uso de neostigmina, forma de administración de los BNM y descripción de complicaciones observadas. RESULTADOS: La mayoría de los anestesiologistas en cuestión ejerce la profesión hace más de 11 años y el mayor número de respuestas fue proveniente de la región sudeste de Brasil. El BNM más empleado es el atracúrio, seguido de pancurónio y succinilcolina. La succinilcolina es más empleada en la inducción rápida y en niños (80% y 25% respectivamente). Monitores de la transmisión neuromuscular, 53% de los anestesiologistas nunca usan, y como criterio de recuperación, 92% consideran el paciente descurarizado mediante señales clínicas. En un 45% de las veces los profesionales emplean la neostigmina de forma rutinaria, y 94% administra los BNM bajo forma de bolus. Cerca del 30% registra que tuvieron complicación consecuent

Maria Cristina Simões de, Almeida.

153

Neuromuscular transmission in hypoxemic patients with chronic obstructive pulmonary disease.  

Science.gov (United States)

Many studies have focused on the systemic effects of chronic obstructive pulmonary disease (COPD), but none has examined neuromuscular junction transmission (NMT). We evaluated NMT dysfunction using single-fiber electromyography (SFEMG) in patients with COPD. Twenty patients with COPD and 20 age-matched healthy controls were included in the study. All patients and controls underwent SFEMG. Abnormal NMT was found in seven of 20 patients (35%), but in none of the control subjects. The COPD patients were subgrouped according to the presence of hypoxemia. The patients with normoxemia were classified as Group 1, and the patients with hypoxemia were classified as Group 2. Abnormal NMT was found in six patients in Group 2 and in one in Group 1. While there was significant difference in terms of abnormal NMT between Group 2 and the controls, there was none between Group 1 and the controls. Our results show that NMT abnormalities can be present in hypoxemic patients with COPD. PMID:23886635

Gulbas, Gazi; Kaplan, Yuksel; Kamisli, Ozden; Ermis, Hilal; Kamisli, Suat; Ozcan, Cemal

2013-10-01

154

Signaling and aging at the neuromuscular synapse: lessons learnt from neuromuscular diseases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The neuromuscular junction (NMJ) is a specialized synapse between motor neurons and skeletal muscle with a complex signaling network that assures highly reliable neuromuscular transmission. Diseases of the NMJ cause skeletal muscle fatigue and include inherited and acquired disorders that affect presynaptic, intrasynaptic or postsynaptic components. Moreover, fragmentation of the NMJ contributes to sarcopenia, the loss of muscle mass during aging. Studies from recent years indicate that the f...

Punga, Anna Rostedt; Ruegg, Markus A.

2012-01-01

155

Effects of a short proprioceptive neuromuscular facilitation stretching bout on quadriceps neuromuscular function, flexibility, and vertical jump performance.  

Science.gov (United States)

The inclusion of relatively long bouts of stretching (repeated static stretches of ?30 seconds) in the warm-up is usually associated with a drop in muscle performance. The purpose of this study was to assess the effect of a novel self-administered proprioceptive neuromuscular facilitation (PNF) paradigm with short periods of stretching and contraction on quadriceps neuromuscular function, vertical jump performance, and articular range of motion (ROM). Twelve healthy men (age: 27.7 ± 7.3 years, height: 178.4 ± 10.4 cm, weight: 73.8 ± 16.9 kg) volunteered to participate in a PNF session and a control session separated by 2-7 days. The PNF stretching lasted 2 minutes and consisted of 4 sets of 5-second isometric hamstring contraction immediately followed by 5 seconds of passive static stretch of the quadriceps immediately followed by 5 seconds isometric quadriceps contraction for each leg. For the control session, the participants were asked to walk at a comfortable speed for 2 minutes. Active ROM of knee flexion, vertical jump performance, and quadriceps neuromuscular function were tested before, immediately after, and 15 minutes after the intervention. The PNF stretching procedure did not affect ROM, squat jump, and countermovement jump performances. Accordingly, we did not observe any change in maximal voluntary contraction force, voluntary activation level, M-wave and twitch contractile properties that could be attributed to PNF stretching. The present self-administered PNF stretching of the quadriceps with short (5-second) stretches is not recommended before sports where flexibility is mandatory for performance. PMID:22505131

Place, Nicolas; Blum, Yannick; Armand, Stéphane; Maffiuletti, Nicola A; Behm, David G

2013-02-01

156

Papel da vitamina D na função neuro-muscular / Role of vitamin D in the neuro-muscular function  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A vitamina D, através de suas ações no intestino, rim, osso e glândulas paratiróides, é um hormônio fundamental para a homeostase do cálcio e para o desenvolvimento de um esqueleto saudável. Além disso, receptores deste hormônio podem ser encontrados em quase todos os tecidos do organismo e outras a [...] ções não relacionadas ao metabolismo mineral têm sido imputadas a ele. Na célula muscular esquelética, a vitamina D atua através do mecanismo clássico de ligação a um receptor nuclear e também através da ligação a um receptor de membrana, realizando ações que envolvem o transporte de cálcio, a síntese protéica e a velocidade de contração muscular. Clinicamente, a deficiência de vitamina D, que é bastante comum em idosos, inclusive em nosso país, tem sido relacionada a um aumento da incidência de quedas, a uma diminuição da força muscular e a uma deterioração do equilíbrio, avaliada pela oscilação do corpo na postura ereta. Por outro lado, tem sido demonstrado que a suplementação associada de cálcio e vitamina D em idosos deficientes contribui para melhoria destes aspectos da função neuro-muscular. Nesta revisão, serão discutidos os mecanismos conhecidos envolvidos na associação entre vitamina D e função neuro-muscular, e também a suplementação de vitamina D e cálcio na prevenção de fraturas osteoporóticas não-vertebrais sob a perspectiva dos efeitos neuro-musculares. Abstract in english Through its action in the kidney, intestines, bone and parathyroid glands vitamin D is a major regulator of calcium homeostasis and for the development of a healthy skeleton. Moreover, receptors for this hormone are present in almost all body tissues and other actions which are not related to the mi [...] neral metabolism have been imputed to it. In the skeletal muscle cell, vitamin D acts through the classic mechanism of binding to a nuclear receptor and also by binding to a membrane receptor, carrying out actions that involve calcium transport, protein synthesis and kinetics of muscle contraction. Clinically, vitamin D deficiency, which is very common among the elderly, including the ones in our country, has been related to an increase in the incidence of falls, as well as the reduction of muscle strength and deterioration of body sway, evaluated by the oscillation of the body in the erect position. On the other hand, it has been demonstrated that supplementation of calcium associated to vitamin D in deficient elderly contributes to the improvement of these aspects of the neuro-muscular function. In this review, the mechanisms involved in the association between vitamin D and neuro-muscular function will be discussed, as well as the supplementation of vitamin D and calcium to prevent non-vertebral osteoporotic fractures under the perspective of the neuro-muscular effects.

Márcia A. Carneiro, Pedrosa; Marise Lazaretti, Castro.

157

Neuromuscular Effects of Acute Organophosphate Poisoning  

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Conclusion: There is no evoked potential studies performed in organophosphate poisoning althoung electroneurography repetitive and P300 studies exist in literature. More further studies are needed to evaluate the cardiac and neuromuscular effects of organophosphate poisoning. [Cukurova Med J 2014; 39(4.000: 795-800

Taylan Pekoz

2014-08-01

158

Neuromuscular hamartoma arising in the brachial plexus  

International Nuclear Information System (INIS)

We report a case brachial plexus neuromuscular hamartoma (choristoma) in a 28-year-old man who complained of numbness of the left hand and forearm for several years. MRI revealed a circumscribed, rounded mass in the left brachial plexus. The patient is well 2 years after surgery, with no neurological deficit. (orig.)

2004-03-01

159

Facilitatory effects of piracetam on excitability of motor nerve terminals and neuromuscular transmission.  

Science.gov (United States)

The possible in vivo facilitatory effects of the pyrrolidine acetamide no-otropic agent piracetam on neuromuscular transmission, were studied based upon reports of enhancement of central cholinergic function. Piracetam was shown to antagonize the lethal effects of the neuromuscular blocking agent hemicholinium-3 (HC-3), in female CF-1 mice when administered in a dose of 100 mg/kg (i.p.) simultaneously with HC-3. A 30 mg/kg (i.p.) dose of piracetam was ineffective by itself, although it potentiated the protective effects of choline (25 mg/kg i.p.). The analogs of piracetam, aniracetam, oxiracetam, pramiracetam and dupracetam also significantly antagonized the lethality of HC-3 at doses over a 30-300 mg/kg range. The acute facilitatory properties of piracetam on neuromuscular transmission were examined in more detail in vivo in the soleus nerve muscle preparation of the cat. A 100 mg/kg (i.v.) dose of piracetam, while having no effect on its own, significantly enhanced the ability of a 200 micrograms/kg (i.v.) dose of edrophonium to produce a potentiation of muscle contraction dependent on repetitive discharges in the soleus motor nerve terminals. In preparations in which the motor nerve terminals of the soleus were in a partially degenerated state as a result of section of the motor axons 48 hr earlier, piracetam acted to restore their sensitivity to edrophonium. Furthermore, in both normal and partially degenerated preparations, piracetam significantly decreased the neuromuscular blocking effects of a 150 micrograms/kg (i.v.) dose of d-tubocurarine. The mechanism of the neuromuscular facilitatory effects of piracetam on neuromuscular transmission is discussed in terms of an enhanced excitability of motor nerve terminals together with an action to increase the synthesis and/or release of acetylcholine. PMID:2829047

Hall, E D; Von Voigtlander, P F

1987-11-01

160

Spectrum of Cyber threats & Available Control Mechanisms  

Directory of Open Access Journals (Sweden)

Full Text Available The Internet is undoubtedly the largest public data network enabling and facilitating both personal & business communications worldwide. Wireless networking has experienced a tremendous growth becoming an integral part of homes, offices & all type of businesses. It provides many advantages, but it is also coupled with many security threats and alters the organizations overall information security risk profile. Although implementation of technological solution is the usual respond to the wireless security threats and vulnerabilities, wireless security is primarily a management issue. Cyber crime is constantly evolving and the growing increase in the number of threats that use social engineering techniques is causing concern for several businesses. All it takes is for one user to click on a malicious link and a firm’s network can be brought to a grinding halt. But the early days of cyber threats have gone now. Cyber threats have increased in large number. The volume of effect of these attacks has increased tremendously whereas the transaction time has decreased. The sources of attacks and exploitations are difficult to determine within time frames that enable victims to avoid damage, and any defensive measure is likely eventually to fail given the vulnerabilities of most cyber systems and the incapacities of users. In this paper we review different cyber threats and control mechanisms available and how these are affecting the network world.

Vikram Mangla, Dr.S.N.Panda

2013-04-01

 
 
 
 
161

Neuromuscular manifestations of viscoelastic tissue degradation following high and low risk repetitive lumbar flexion.  

Science.gov (United States)

Cumulative lumbar disorder is common in individuals engaged in long term performance of repetitive and static occupational/sports activities with the spine. The triggering source and of the disorder, the tissues involved in the failure and the biomechanical, neuromuscular, and biological processes active in the initiation and development of the disorder are not known. The hypothesis is forwarded that static and repetitive (cyclic) lumbar flexion-extension and the associated repeated stretch of the various viscoelastic tissues (ligaments, fascia, facet capsule, discs, etc.) causes micro-damage in their collagen fibers followed by an acute inflammation, triggering pain and reflexive muscle spasms/hyper-excitability. Continued exposure to activities, over time, converts the acute inflammation into a chronic one, viscoelastic tissues remodeling/degeneration, modified motor control strategy and permanent disability. Changes in lumbar stability are expected during the development of the disorder. A series of experimental data from in-vivo feline is reviewed and integrated with supporting evidence from the literature to gain a valuable insight into the multi-factorial development of the disorder. Prolonged cyclic lumbar flexion-extension at high loads, high velocities, many repetitions and short in between rest periods induced transient creep/laxity in the spine, muscle spasms and reduced stability followed, several hours later, by an acute inflammation/tissue degradation, muscular hyper-excitability and increased stability. The major findings assert that viscoelastic tissues sub-failure damage is the source and inflammation is the process which governs the mechanical and neuromuscular characteristic symptoms of the disorder. A comprehensive model of the disorder is presented. The experimental data validates the hypothesis as well as provide insights into the development of potential treatment and prevention of the disorder. PMID:22154465

Solomonow, M

2012-04-01

162

Tratamiento farmacológico de las alteraciones neuromusculares en el paciente crítico / Pharmacological treatment neuromuscular impairments in critically ill patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish El empleo de fármacos para tratamiento de las alteraciones neuromusculares que se presentan en el enfermo ingresado en una Unidad de Cuidados Intensivos es prácticamente inexistente. El empleo de inmunoglobulinas por vía venosa para el tratamiento de la polineuropatía del paciente crítico (PPC) no a [...] porta ninguna evidencia para su uso. Más importancia tiene el tratamiento profiláctico, como es el caso de la administración de una perfusión de insulina para prevenir la hiperglucemias que seasocian a un mayor desarrollo de la PPC. Nuevos datos inducen a pensar que el mecanismo protector de esta perfusión, normalizando los niveles de glucosa se hacen modulando una disfunción endotelial y a unos menores niveles de dimetilarginina asimétrica (ADMA). Con respecto a la miopatía del paciente crítico o a los cuadros de bloqueo neuromuscular prolongado, el tratamiento consiste en evitar el empleo de diversos fármacos que se sabe se asocian al desarrollo de estas entidades como son los corticoides, los relajantes musculares y los aminoglucósidos. Por lo que respecta a la parálisis aguda flácida -infección por el virus del oeste del nilo se han comunicado casos anecdóticos de mejoría con el empleo de corticoides o de interferón, pero su tratamiento rutinario queda aún por establecer. Abstract in english The use of drugs for treating neuromuscular impairments that present in the patient admitted to the Intensive Care Unit is virtually inexistent. The use of intravenous immunoglobulins for managing polyneuropathy of the critically ill patient (PCIP) is supported by no evidence. More important is prop [...] hylactic therapy, as is the administration of insulin perfusion to prevent hyperglycemia that is associated to increased development of PCIP. New data suggest that the protective mechanism of this perfusion, which normalizes glucose levels, is achieved through the modulation of endothelial dysfunction and lowering levels of asymmetrical di-methyl arginine (ADMA). As for myopathy of the critically ill patient or conditions with prolonged neuromuscular blockade, treatment consists in avoiding the use of several drugs known to be associated with development of these conditions, such as muscle relaxants and aminoglycosides. In relation to acute flaccid paralysis -an infection caused by the Western Nile Virus, anecdotic cases have been reported of improvement with the use steroids or interferon, although routine management remains to be established.

Ortiz Leyba, C..

163

Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals  

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Full Text Available This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System, a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES and, as a novelty, the myomechanic signals (MMS. In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

Patricia Fernández

2010-12-01

164

Respiratory management of acute respiratory failure in neuromuscular diseases.  

Science.gov (United States)

Neuromuscular diseases (NMD) can affect all major respiratory muscles, leading to the development of respiratory failure, which is the most common cause of morbidity and mortality in patients affected by those conditions. Based on the clinical onset of acute respiratory failure (ARF), NMD can be classified into two main categories: 1) slowly progressive NMD with acute exacerbations of chronic respiratory failure, and 2) rapidly progressive NMD with acute episodes of respiratory failure. The most common slowly progressive NMDs, such as motor neuron diseases and inherited myopathies, account for the majority of NMD patients developing chronic neuromuscular respiratory failure at risk of acute exacerbations. Conversely, rapidly progressive NMDs, such as Guillain-Barré syndrome and myasthenic crises, are characterized by a sudden onset of ARF, usually in patients with previously normal respiratory function. The patho-physiological mechanisms responsible for ARF in NMD and the variety and complexity of specific challenges presented by the two main categories of NMD will be analyzed in this review, with the aim of providing clinically relevant suggestions for adequate respiratory management of these patients. PMID:20125073

Racca, F; Del Sorbo, L; Mongini, T; Vianello, A; Ranieri, V M

2010-01-01

165

Research Group Introduction : Mechanical Control Engineering Laboratory, Mechanical Engineering Department, Shibaura Institute of Technology  

Science.gov (United States)

Mechanical Control Engineering Laboratory focuses on the control theory and implementation for the robotic applications. The research themes include network based tele-operation, mobile robots control for network relay, autonomous outdoor mobile robot and biped robot.

??, ?

166

Neuromuscular effects of G93A-SOD1 expression in zebrafish  

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Full Text Available Abstract Background Amyotrophic lateral sclerosis (ALS is a fatal disorder involving the degeneration and loss of motor neurons. The mechanisms of motor neuron loss in ALS are unknown and there are no effective treatments. Defects in the distal axon and at the neuromuscular junction are early events in the disease course, and zebrafish provide a promising in vivo system to examine cellular mechanisms and treatments for these events in ALS pathogenesis. Results We demonstrate that transient genetic manipulation of zebrafish to express G93A-SOD1, a mutation associated with familial ALS, results in early defects in motor neuron outgrowth and axonal branching. This is consistent with previous reports on motor neuron axonal defects associated with familial ALS genes following knockdown or mutant protein overexpression. We also demonstrate that upregulation of growth factor signaling is capable of rescuing these early defects, validating the potential of the model for therapeutic discovery. We generated stable transgenic zebrafish lines expressing G93A-SOD1 to further characterize the consequences of G93A-SOD1 expression on neuromuscular pathology and disease progression. Behavioral monitoring reveals evidence of motor dysfunction and decreased activity in transgenic ALS zebrafish. Examination of neuromuscular and neuronal pathology throughout the disease course reveals a loss of neuromuscular junctions and alterations in motor neuron innervations patterns with disease progression. Finally, motor neuron cell loss is evident later in the disease. Conclusions This sequence of events reflects the stepwise mechanisms of degeneration in ALS, and provides a novel model for mechanistic discovery and therapeutic development for neuromuscular degeneration in ALS.

Sakowski Stacey A

2012-08-01

167

Coherent, mechanical control of a single electronic spin.  

Science.gov (United States)

We demonstrate coherent quantum control of a single spin driven by the motion of a mechanical resonator. The motion of a mechanical resonator is magnetically coupled to the electronic spin of a single nitrogen-vacancy center in diamond. Synchronization of spin-addressing protocols to the motion of the driven oscillator is used to fully exploit the coherence of this hybrid mechanical-spin system. We demonstrate applications of this coherent mechanical spin-control technique to nanoscale scanning magnetometry. PMID:22800099

Hong, Sungkun; Grinolds, Michael S; Maletinsky, Patrick; Walsworth, Ronald L; Lukin, Mikhail D; Yacoby, Amir

2012-08-01

168

Gastrointestinal neuromuscular pathology in chronic constipation.  

Science.gov (United States)

Some patients with chronic constipation may undergo colectomy yielding tissue appropriate to diagnosis of underlying neuromuscular pathology. The analysis of such tissue has, over the past 40 years, fueled research that has explored the presence of neuropathy, myopathy and more recently changes in interstitial cells of Cajal (ICC). In this chapter, the data from these studies have been critically reviewed in the context of the significant methodological and interpretative issues that beset the field of gastrointestinal neuromuscular pathology. On this basis, reductions in ICC appear to a consistent finding but one whose role as a primary cause of slow-transit constipation requires further evaluation. Findings indicative of significant neuropathy or myopathy are variable and in many studies subject to considerable methodological bias. Methods with practical diagnostic utility in the individual patient have rarely been employed and require further validation in respect of normative data. PMID:21382578

Knowles, Charles H; Farrugia, Gianrico

2011-02-01

169

Neuromuscular monitoring: old issues, new controversies.  

Science.gov (United States)

"Expert" editorial opinion suggests that objective or quantitative neuromuscular monitors should be used whenever nondepolarizing blocking agents are administered. It is clear that this advice has by and large fallen on deaf ears. A sizeable number of clinicians here (North America) and abroad (Europe) fail to use even conventional peripheral nerve stimulators routinely. This chapter will explore potential reasons for and consequences of this disconnect between academia and "the real world." Along the way, we will examine such questions as how do we define and measure adequate recovery from nondepolarizing block. What are the limitations of clinical tests of recovery such as the "head-lift test?" What is the incidence of undetected postoperative residual curarization (PORC)? Does neuromuscular monitoring reduce the frequency of PORC? How will the availability of sugammadex alter the above discussion? PMID:19272534

Kopman, Aaron F

2009-03-01

170

Uso de sugamadex após reversão incompleta com neostigmine do bloqueio neuromuscular induzido por rocurônio / Use of sugammadex after neostigmine incomplete reversal of rocuronium-induced neuromuscular blockade / Uso de sugamadex después de la reversión incompleta con neostigmine del bloqueo neuromuscular inducido por rocuronio  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese JUSTIFICATIVA E OBJETIVOS: O uso de bloqueadores neuromusculares (BNM) na prática anestésica já tem mais de meio século e sempre foi um desafio para os anestesiologistas. Até bem pouco tempo a reversão dos bloqueadores neuromusculares adespolarizantes só possuia uma opção: a utilização de anticoline [...] sterásicos. No entanto em algumas situações como na presença de bloqueio neuromuscular profundo após o uso de altas doses do relaxante, o uso de anticolinesterásicos não possibilita a adequada reversão do bloqueio neuromuscular. Recentemente uma ciclodextrina gama mostrou-se altamente eficaz para a reversão do BNM de agentes esteroidais, o sugamadex. RELATO DO CASO: Paciente do sexo feminino, submetida à laparotomia exploradora de emergência após intubação em sequência rápida com uso de rocurônio 1,2 mg.kg-1. Ao final da cirurgia a paciente foi descurarizada com neostigmina, no entanto a monitoração da junção neuromuscular não apresentou a recuperação esperada, revelando curarização residual. Foi utilizado sugamadex 2 mg.kg-1 e a paciente apresenta reversão completa do BNM em apenas 2 minutos. CONCLUSÃO: A adequada recuperação do bloqueio neuromuscular residual é necessária para o pleno controle das funções da faringe e respiratória, evitando assim complicações. A adequada recuperação só pode ser obtida através da monitoração da junção neuromuscular com uma relação de TOF acima de 0,9. Muitas vezes a reversão do BNM com o uso de anticolinesterásicos pode não reverter completamente o BNM, no entanto na ausência da monitoração objetiva este diagnóstico não é possível. O caso ilustra o diagnóstico de BNM residual mesmo após a reversão com anticolinesterásicos, resolvido com a administração de sugamadex, uma alternativa segura para a reversão dos BNM adespolarizantes esteroidais. Abstract in spanish JUSTIFICATIVA Y OBJETIVOS: El uso de bloqueantes neuromusculares (BNM) en la práctica anestésica cuenta ya con más de medio y siempre fue un reto para los anestesiólogos. Hasta hace poco tiempo la reversión de los bloqueantes neuromusculares adespolarizantes solo tenía una opción: la utilización de [...] antocolinesterásicos. Sin embargo, en algunas situaciones como en presencia de bloqueo neuromuscular profundo después del uso de altas dosis del relajante, el uso de anticolinesterásicos no posibilita la adecuada reversión del bloqueo neuromuscular. Recientemente una ciclodextrina gama mostró ser altamente eficaz para la reversión del BNM de agentes esteroidales, como el sugamadex. RELATO DE CASO: Paciente del sexo femenino, sometida a la laparotomía exploradora de emergencia después de la intubación en secuencia rápida con el uso de rocuronio 1,2 mg.kg-1. Al término de la operación, la paciente fue descurarizada con neostigmina, pero la monitorización de la junción neuromuscular no presentó la recuperación esperada, revelando la curarización residual. Fue utilizado sugamadex 2 mg.kg-1 y comprobamos que la paciente presenta una reversión completa del BNM en solamente 2 minutos. CONCLUSIONES: La correcta recuperación del bloqueo neuromuscular residual es necesaria para el pleno control de las funciones de la faringe y respiratoria, evitando así complicaciones. La adecuada recuperación solo puede obtenerse por medio de la monitorización de la junción neuromuscular con una relación de TOF por encima de 0,9. En muchas ocasiones, la reversión del BNM con el uso de anticolinesterásicos puede no revertir completamente el BNM, pero sin embargo en ausencia de la monitorización objetiva, ese diagnóstico no puede ser alcanzado. El caso ilustra el diagnóstico de BNM residual incluso después de la reversión con anticolinesterásicos, resuelto con la administración de sugamadex, una alternativa segura para la reversión de los BNM adespolarizantes esteroidales. Abstract in english BACKGROUND AND OBJECTIVES: Neuromuscular blockers (NMB) have been used

Cássio Campelo de, Menezes; Lilian Akemi Moore, Peceguini; Enis Donizetti, Silva; Claudia Marquez, Simões.

171

Analysis and control of underactuated mechanical systems  

CERN Document Server

This monograph provides readers with tools for the analysis, and control of systems with fewer control inputs than degrees of freedom to be controlled, i.e., underactuated systems. The text deals with the consequences of a lack of a general theory that would allow methodical treatment of such systems and the ad hoc approach to control design that often results, imposing a level of organization whenever the latter is lacking. The authors take as their starting point the construction of a graphical characterization or control flow diagram reflecting the transmission of generalized forces through the degrees of freedom. Underactuated systems are classified according to the three main structures by which this is found to happen—chain, tree, and isolated vertex—and control design procedures proposed. The procedure is applied to several well-known examples of underactuated systems: acrobot; pendubot; Tora system; ball and beam; inertia wheel; and robotic arm with elastic joint. The text is illustrated with MATL...

Choukchou-Braham, Amal; Djemaï, Mohamed; Busawon, Krishna

2014-01-01

172

Reconstruction of the neuromuscular junction connectome  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Motivation: Unraveling the structure and behavior of the brain and central nervous system (CNS) has always been a major goal of neuroscience. Understanding the wiring diagrams of the neuromuscular junction connectomes (full connectivity of nervous system neuronal components) is a starting point for this, as it helps in the study of the organizational and developmental properties of the mammalian CNS. The phenomenon of synapse elimination during developmental stages of the neuronal circuitry i...

Srinivasan, Ranga; Wong, Stephen T. C.; Li, Qing; Lichtman, Jeff; Lu, Ju; Zhou, Xiaobo

2010-01-01

173

The emerging diversity of neuromuscular junction disorders  

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Research advances over the last 30 years have shown that key transmembrane proteins at the neuromuscular junction are vulnerable to antibody-mediated autoimmune attack These targets are acetylcholine receptors (AChRs) and muscle specific kinase (MuSK) in myasthenia gravis, voltage-gated calcium channels (VGCCs) in the Lambert-Eaton myasthenic syndrome (LEMS), and voltage-gated potassium channels (VGKCs) in neuromyotonia. In parallel with these immunological advances, mutations identified in g...

2007-01-01

174

Neuromuscular Diseases Associated with HIV-1 Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Neuromuscular disorders are common in HIV, occurring at all stages of disease and affecting all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, co-morbid illnesses and infections, and side effects of medications. In this article, we review the following HIV-associated conditions: distal symmetric polyneuropathy, inflammatory demyelinating polyneuropathy, mononeuropathy, mononeuropathy multiplex, autono...

Robinson-papp, Jessica; Simpson, David M.

2009-01-01

175

Reconstruction of the Neuromuscular Junction Connectome  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Motivation: Unraveling the structure and behavior of the brain and central nervous system (CNS) has always been a major goal of neuroscience. Understanding the wiring diagrams of the neuromuscular junction connectomes (full connectivity of nervous system neuronal components) is a starting point for this, as it helps in the study of the organizational and developmental properties of the mammalian CNS. The phenomenon of synapse elimination during developmental stages of the neuronal circuitry i...

Srinivasan, Ranga; Wong, Stephen T. C.; Li, Qing; Lichtman, Jeff; Lu, Ju; Zhou, Xiaobo

2010-01-01

176

Neuromuscular Compression Garments: Effects on Neuromuscular Strength and Recovery  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Graduated compression stockings have been used as a mechanical method of deep vein thrombosis prophylaxis for several years. Several studies have demonstrated an increase in mean deep venous velocity, reduced venous pooling, improved venous return, and increase blood lactate clearance in subjects who wore graduated compression stockings during exercise. A possible improvement in venous return during and after exercise may facilitate the clearance of metabolites produced during exercise. Also,...

Bottaro, Martim; Martorelli, Saulo; Vilac?a, Jose?

2011-01-01

177

Control of underactuated mechanical systems by the transverse function approach  

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An approach for the control of a class of underactuated mechanical systems on Lie groups, including many systems previously studied in the control literature, like underactuated planar manipulators and rigid bodies (spacecrafts, hovercrafts, etc), is proposed. The main outcome of the paper is the derivation, based on the transverse function approach initially proposed by the authors for the control of non-holonomic (driftless) mechanical systems, of smooth feedback control laws which stabiliz...

Morin, Pascal; Samson, Claude

2005-01-01

178

Neuromuscular scoliosis - surgical management and outcomes  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Neuromuscular scoliosis affects a heterogeneous group of patients with myopathic, upper and lower motor neuron diseases. Spinal surgery is often required to optimise respiratory, sitting and ambulatory function. OBJECTIVES: Review of management and outcomes of surgically treated neuromuscular scolio [...] sis. STUDY DESIGN: Retrospective review of prospectively maintained data, including demographics, intra-operative variables, pre- and post-operative imaging, complications, outcomes and a telephonic follow-up questionnaire. RESULTS: Ninety-eight patients (45 male and 53 female) were included in the study. The average operating time was 230 (100-525 ± 60.9) minutes and an average of 15.4 (8-19 ± 2.9) levels were fused. Pedicle screw only constructs corrected the primary curve by 63% initially and 56% correction at last follow-up. Hybrid constructs had an immediate correction of 69% and 47% at last follow-up. Although pedicle screw constructs lost less correction when compared to hybrid constructs, this was not a statistically significant difference. Pelvic obliquity was corrected from 14.02 (0-80 ± 15.54) to 4.06 (0-35 ± 7.69) degrees. The majority of the telephonic responses were positive. CONCLUSION: : Corrective spinal surgery in the neuromuscular patient is demanding with a high rate of complications but outcomes are good, with radiographic correction maintained in the long term and high level of patient and parent satisfaction. LEVEL OF EVIDENCE: III

A, Puddu; RN, Dunn.

179

Neuromuscular transmission modulation by adenosine upon aging.  

Science.gov (United States)

In infant rats adenosine A(2A) receptor-mediated modulation of neuromuscular transmission predominates over A1 receptor-mediated neuromodulation. We investigated whether aging affects this A(2A)/A(1) receptor balance. Evoked (EPPs) and miniature end plate potentials (MEPPs) were recorded from single fibers of (weeks-old) infant (3-4), young adult (12-16), older (36-38), and aged (80-90) male rat-diaphragm. The non A1/A(2A) selective agonist, 2-chloroadenosine (CADO; 30 nM) and the adenosine kinase inhibitor, iodotubericidin (ITU; 10 ?M) increased mean amplitude and quantal content of EPPs in infant, young adult, and older adult rats, but not in aged rats. The facilitatory effects were prevented by the A(2A) receptor antagonist, ZM241385 (50 nM) and mimicked by the A(2A) receptor agonist, CGS21680 (10 nM). The A1 receptor agonist, 6-cyclopentyladenosine (CPA; 100 nM), decreased EPPs amplitude in all age groups. It is concluded that aging differently influences adenosine A1 receptor and A(2A) receptor-mediated presynaptic modulation of neuromuscular transmission, so that the facilitatory influence decreases upon aging, whereas the inhibitory influence remains unchanged in aged animals. The reduction of adenosine A(2A) receptors upon aging may contribute to the age-related changes in neuromuscular function. PMID:22365485

Pousinha, Paula A; Correia, Alexandra M; Sebastião, Ana M; Ribeiro, Joaquim A

2012-12-01

180

Computer aided control of a mechanical arm  

Science.gov (United States)

A method for computer-aided remote control of a six-degree-of-freedom manipulator arm involved in the on-orbit servicing of a spacecraft is presented. The control configuration features a supervisory type of control in which each of the segments of a module exchange trajectory is controlled automatically under human supervision, with manual commands to proceed to the next step and in the event of a failure or undesirable outcome. The implementation of the supervisory system is discussed in terms of necessary onboard and ground- or Orbiter-based hardware and software, and a one-g demonstration system built to allow further investigation of system operation is described. Possible applications of the system include the construction of satellite solar power systems, environmental testing and the control of heliostat solar power stations.

Derocher, W. L., Jr.; Zermuehlen, r. O.

1979-01-01

 
 
 
 
181

Neuromuscular stimulation therapy after incomplete spinal cord injury promotes recovery of interlimb coordination during locomotion  

Science.gov (United States)

The mechanisms underlying the effects of neuromuscular electrical stimulation (NMES) induced repetitive limb movement therapy after incomplete spinal cord injury (iSCI) are unknown. This study establishes the capability of using therapeutic NMES in rodents with iSCI and evaluates its ability to promote recovery of interlimb control during locomotion. Ten adult female Long Evans rats received thoracic spinal contusion injuries (T9; 156 ± 9.52 Kdyne). 7 days post-recovery, 6/10 animals received NMES therapy for 15 min/day for 5 days, via electrodes implanted bilaterally into hip flexors and extensors. Six intact animals served as controls. Motor function was evaluated using the BBB locomotor scale for the first 6 days and on 14th day post-injury. 3D kinematic analysis of treadmill walking was performed on day 14 post-injury. Rodents receiving NMES therapy exhibited improved interlimb coordination in control of the hip joint, which was the specific NMES target. Symmetry indices improved significantly in the therapy group. Additionally, injured rodents receiving therapy more consistently displayed a high percentage of 1:1 coordinated steps, and more consistently achieved proper hindlimb touchdown timing. These results suggest that NMES techniques could provide an effective therapeutic tool for neuromotor treatment following iSCI.

Jung, R.; Belanger, A.; Kanchiku, T.; Fairchild, M.; Abbas, J. J.

2009-10-01

182

Sugammadex reversal of rocuronium-induced neuromuscular blockade in two types of neuromuscular disorders: Myotonic dystrophy and spinal muscular atrophy.  

Science.gov (United States)

Neuromuscular disorders like myotonic dystrophy (dystrophia myotonica or Steinert's disease) and spinal muscular atrophy are associated with perioperative complications related to muscle weakness. These patients have an increased sensitivity to non-depolarising neuromuscular blocking agents, which can lead to postoperative residual curarization (PORC) and its associated respiratory complications. Adequate reversal of neuromuscular blockade is essential to prevent this. Sugammadex is the first selective relaxant binding agent and it reverses rocuronium- and vecuronium-induced neuromuscular block. Two cases are reported in which the patients received sugammadex to reverse a rocuronium-induced neuromuscular block. Reversal of the rocuronium-induced neuromuscular block (NMB) in both cases was fast, effective and without recurarization, and no safety concerns were observed. PMID:22947194

Stewart, P A; Phillips, S; De Boer, H D

2013-04-01

183

Mechanisms for leaf control of gas exchange  

Energy Technology Data Exchange (ETDEWEB)

Several mechanisms enable leaf stomata to optimize water loss with respect to carbon gain. Stomatal responses to environmental variation constitute a plant's first and second lines of defense against damaging water deficits. Changes in the concentrations of endogenous growth regulations and their influence on stomata may well be important to both defense strategies.

Mansfield, T.A.; Davies, W.J.

1985-03-01

184

Multi-Function Magnetic Jack Control Drive Mechanism.  

Science.gov (United States)

A multi-function magnetic jack control drive mechanism for controlling a nuclear reactor is provided. The mechanism includes an elongate pressure housing in which a plurality of closely spaced drive rods are located. Each drive rod is connected to a rod w...

L. R. Bollinger D. C. Crawford

1983-01-01

185

Controlling a mechanical oscillator with a tunable coherent feedback network  

CERN Multimedia

We demonstrate a fully cryogenic microwave feedback network composed of distinct superconducting devices interconnected by waveguides and designed to control a mechanical oscillator coupled to one of the devices. The network is partitioned into an electromechanical device to be controlled and a dynamically tunable controller that coherently receives, processes and feeds back continuous microwave signals that modify the dynamics and readout of the mechanical state. While previous electromechanical systems represent some compromise between efficient control and efficient readout of the mechanical state, as set by the electromagnetic decay rate, this flexible controller yields a closed-loop network that can be dynamically and continuously tuned between both extremes much faster than the mechanical response time. We demonstrate that the microwave decay rate may be modulated by at least a factor of 10 at a rate greater than $10^4$ times the mechanical response rate.

Kerckhoff, Joseph; Ku, H S; Kindel, William F; Cicak, Katarina; Simmonds, Raymond W; Lehnert, K W

2012-01-01

186

Novel Mechanism Control Algorithm for Wired Network  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: A critical issue in wireless network where the data can hack by the person and we add a novel encryption mechanism to protect the data transfer from client to server and vice versa. Approach: We present a queuing model of a client and server that uses for bulk arrival service. The arrival of data requests is assumed to Markov Poisson Distributed Process (MPDP) and the events are considered in the server for process sharing. We obtained the ...

2011-01-01

187

Flow-control mechanism for distributed systems  

Science.gov (United States)

A new approach to the rate-based flow control in store-and-forward networks is evaluated. Existing methods display oscillations in the presence of transport delays. The proposed scheme is based on the explicit use of an embedded dynamic model of a store-and-forward buffer in a controller's feedback loop. It is shown that the use of the model eliminates the oscillations caused by the transport delays. The paper presents simulation examples and assesses the applicability of the scheme in the new generation of high-speed photonic networks where transport delays must be considered.

Maitan, Jacek

1991-08-01

188

Strength training induced adaptations in neuromuscular function of premenopausal women with fibromyalgia: comparison with healthy women  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVE—To investigate the effects of 21 weeks' progressive strength training on neuromuscular function and subjectively perceived symptoms in premenopausal women with fibromyalgia (FM).?METHODS—Twenty one women with FM were randomly assigned to experimental (FMT) or control (FMC) groups. Twelve healthy women served as training controls (HT). The FMT and HT groups carried out progressive strength training twice a week for 21 weeks. The major outcome measures were muscle strength...

Hakkinen, A.; Hakkinen, K.; Hannonen, P.; Alen, M.

2001-01-01

189

Neuromuscular induced phonation in a human ex vivo perfused larynx preparation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Considering differences in laryngeal anatomy, degree of control, and range of voice qualities between animals and humans, investigations of the neuromuscular process of voice control are better conducted using a living human larynx in which parametric stimulation of individual laryngeal muscles is possible. Due to difficulties in access and monitoring of laryngeal muscle activities, such investigations are impossible in living human subject experiments. This study reports the recent success i...

Berke, Gerald; Mendelsohn, Abie H.; Scott Howard, Nelson; Zhang, Zhaoyan

2013-01-01

190

Cutaneous mechanisms of isometric ankle force control  

DEFF Research Database (Denmark)

The sense of force is critical in the control of movement and posture. Multiple factors influence our perception of exerted force, including inputs from cutaneous afferents, muscle afferents and central commands. Here, we studied the influence of cutaneous feedback on the control of ankle force output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured the effects of repetitive nerve stimulation on (1) tactile thresholds, (2) performance in an ankle force-matching and (3) an ankle position-matching task. Additional force-matching experiments were done to compare the effects of transient versus continuous stimulation in 6 subjects and to determine the effects of foot anesthesia using lidocaine in another 6 subjects. The results showed that stimulation decreased cutaneous sensory function as evidenced by increased touch threshold. Absolute dorsiflexion force error increased without visual feedback during peroneal nerve stimulation. This was not a general effect of stimulation because force error did not increase during plantar nerve stimulation. The effects of transient stimulation on force error were greater when compared to continuous stimulation and lidocaine injection. Position-matching performance was unaffected by peroneal nerve or plantar nerve stimulation. Our results show that cutaneous feedback plays a role in the control of force output at the ankle joint. Understanding how the nervous system normally uses cutaneous feedback in motor control will help us identify which functional aspects are impaired in aging and neurological diseases.

Choi, Julia T; Jensen, Jesper Lundbye

2013-01-01

191

Signaling mechanisms controlling taste cell function.  

Science.gov (United States)

Sensory systems have evolved to collect information about the environment. Each system has developed to gather specific data that are pertinent to an organism's needs, and consequently the systems vary in their abilities to detect external stimuli such as light, sound, vibration, magnetic fields, or chemicals. Although not all sensory systems are present in all organisms, all organisms, even those at the single-cell level, have the ability to detect chemicals in the environment. Chemical detection likely evolved out of organisms' needs to detect food sources and avoid potentially harmful compounds. Higher-level organisms developed two sensory systems to detect environmental chemicals: olfaction and taste. Olfaction is used in many behaviors, such as kin recognition and mate selection, whereas taste is used primarily to determine whether potential food items will be ingested or rejected. The sense of taste involves the detection of five taste qualities: bitter, sweet, salty, sour, and umami, which is the detection of amino acids, specifically glutamate. Because the chemical structures of taste qualities are diverse, numerous mechanisms are used by taste cells to detect these stimuli. This review focuses on our current understanding of the signaling mechanisms used by taste cells to transduce stimulus signals. PMID:18304027

Medler, Kathryn

2008-01-01

192

Installing and detaching apparatus for a control rod drive mechanism  

International Nuclear Information System (INIS)

Object: To facilitate maintenance and repair of a control rod drive mechanism. Structure: The apparatus comprises a means moving in a moving direction of a control rod within a reactor vessel, said moving means having a housing mounted thereon, a means mounted on the reactor vessel to release a connection between a control rod drive mechanism connected to the control rod and the control rod, and a means for mounting and removing a fixing means which connects the reactor vessel to the control rod drive means. With this arrangement, cooling water of high radioactivity level may not be leaked outside to thereby notably reduce dangerousness of exposure and materially cut time required for mounting and removing the control rod drive mechanism. (Ohara, T.)

1976-01-01

193

Avaliação da ativação neuromuscular em indivíduos com escoliose através da eletromiografia de superfície / Assessment of neuromuscular activation in individuals with scoliosis using surface electromyography  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: O objetivo desse estudo foi verificar o potencial da eletromiografia (EMG) de superfície para a avaliação da eficiência neuromuscular e da fadiga muscular localizada dos extensores lombares em indivíduos com escoliose. MÉTODOS: Participaram deste estudo 20 indivíduos divididos igualmente e [...] m dois grupos, (1) Grupo com Escoliose e (2) Grupo Controle, que foram submetidos a um teste de indução dos músculos extensores lombares a fadiga, o qual constituiu da realização de uma contração voluntária máxima isométrica (CVM), e realização de um teste com esforço a 80% da CVM. Foram coletados simultaneamente sinais de força e eletromiográficos (sinal EMG). O sinal EMG foi processado no domínio da freqüência, utilizando-se a transformada rápida de Fourier (FFT), por meio da mediana da freqüência (MF), e no domínio do tempo, pelo cálculo do valor root mean square (RMS). Os dados foram submetidos a uma análise de variância one-way para verificar as diferenças entre os dois grupos. Para verificar a simetria entre os lados direito e esquerdo, foi realizado o teste t pareado. O nível de significância adotado foi 0,05. RESULTADOS: os resultados demonstraram que indivíduos com escoliose apresentaram: (1) simetria de ativação neuromuscular entre os lados; (2) menor eficiência neuromuscular; (3) maior capacidade de resistir a fadiga; e (4) valores de força 42,6% menores que os indivíduos do GC. CONCLUSÕES: Os resultados sugerem que a EMG de superfície corresponde a um efetivo instrumento de avaliação funcional da escoliose, embora o protocolo estabelecido tenha limitado a participação dos indivíduos com escoliose, do ponto de vista da eficiência neuromuscular. Abstract in english OBJECTIVE: The aim of this study was to investigate the potential of surface electromyography (EMG) for assessing neuromuscular efficiency and localized muscle fatigue in the lumbar extensors, in individuals with scoliosis. METHODS: Twenty individuals participated in this study, divided equally into [...] two groups: (1) Scoliosis Group and (2) Control Group. These subjects underwent a fatigue induction test on their lumbar extensor muscles, consisting of one maximum voluntary isometric contraction (MVIC) followed by a test at 80% of the MVIC effort. Force and EMG signals were collected simultaneously. The EMG signal was processed in the frequency domain by means of fast Fourier transforms using the median frequency; and in the time domain by calculating the root mean square value. The data were analyzed by means of one-way analysis of variance to investigate the differences between the two groups. Paired t test was used to investigate the symmetry between the right and left sides. The significance level adopted was 0.05. RESULTS: The results showed that the individuals with scoliosis presented: (1) symmetrical neuromuscular activation between the sides; (2) lower neuromuscular efficiency; (3) greater capacity to resist fatigue; and (4) force values 42.6% lower than those of the individuals in the Control Group. CONCLUSIONS: The results suggest that surface EMG is an effective tool for functional assessments of scoliosis, although the protocol established limited the participation of individuals with scoliosis, from the perspective of neuromuscular efficiency.

Bassani, E; Candotti, CT; Pasini, M; Melo, M; La Torre, M.

194

Avaliação da ativação neuromuscular em indivíduos com escoliose através da eletromiografia de superfície Assessment of neuromuscular activation in individuals with scoliosis using surface electromyography  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: O objetivo desse estudo foi verificar o potencial da eletromiografia (EMG de superfície para a avaliação da eficiência neuromuscular e da fadiga muscular localizada dos extensores lombares em indivíduos com escoliose. MÉTODOS: Participaram deste estudo 20 indivíduos divididos igualmente em dois grupos, (1 Grupo com Escoliose e (2 Grupo Controle, que foram submetidos a um teste de indução dos músculos extensores lombares a fadiga, o qual constituiu da realização de uma contração voluntária máxima isométrica (CVM, e realização de um teste com esforço a 80% da CVM. Foram coletados simultaneamente sinais de força e eletromiográficos (sinal EMG. O sinal EMG foi processado no domínio da freqüência, utilizando-se a transformada rápida de Fourier (FFT, por meio da mediana da freqüência (MF, e no domínio do tempo, pelo cálculo do valor root mean square (RMS. Os dados foram submetidos a uma análise de variância one-way para verificar as diferenças entre os dois grupos. Para verificar a simetria entre os lados direito e esquerdo, foi realizado o teste t pareado. O nível de significância adotado foi 0,05. RESULTADOS: os resultados demonstraram que indivíduos com escoliose apresentaram: (1 simetria de ativação neuromuscular entre os lados; (2 menor eficiência neuromuscular; (3 maior capacidade de resistir a fadiga; e (4 valores de força 42,6% menores que os indivíduos do GC. CONCLUSÕES: Os resultados sugerem que a EMG de superfície corresponde a um efetivo instrumento de avaliação funcional da escoliose, embora o protocolo estabelecido tenha limitado a participação dos indivíduos com escoliose, do ponto de vista da eficiência neuromuscular.OBJECTIVE: The aim of this study was to investigate the potential of surface electromyography (EMG for assessing neuromuscular efficiency and localized muscle fatigue in the lumbar extensors, in individuals with scoliosis. METHODS: Twenty individuals participated in this study, divided equally into two groups: (1 Scoliosis Group and (2 Control Group. These subjects underwent a fatigue induction test on their lumbar extensor muscles, consisting of one maximum voluntary isometric contraction (MVIC followed by a test at 80% of the MVIC effort. Force and EMG signals were collected simultaneously. The EMG signal was processed in the frequency domain by means of fast Fourier transforms using the median frequency; and in the time domain by calculating the root mean square value. The data were analyzed by means of one-way analysis of variance to investigate the differences between the two groups. Paired t test was used to investigate the symmetry between the right and left sides. The significance level adopted was 0.05. RESULTS: The results showed that the individuals with scoliosis presented: (1 symmetrical neuromuscular activation between the sides; (2 lower neuromuscular efficiency; (3 greater capacity to resist fatigue; and (4 force values 42.6% lower than those of the individuals in the Control Group. CONCLUSIONS: The results suggest that surface EMG is an effective tool for functional assessments of scoliosis, although the protocol established limited the participation of individuals with scoliosis, from the perspective of neuromuscular efficiency.

E Bassani

2008-02-01

195

Novel Mechanism Control Algorithm for Wired Network  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: A critical issue in wireless network where the data can hack by the person and we add a novel encryption mechanism to protect the data transfer from client to server and vice versa. Approach: We present a queuing model of a client and server that uses for bulk arrival service. The arrival of data requests is assumed to Markov Poisson Distributed Process (MPDP and the events are considered in the server for process sharing. We obtained the parameter of service rate, arrival rate, expected waiting time and expected busy period. We also derive the expression for the data value of threshold. Results: The total number of packets request processed, there was no time limit to arrivals, while compared to m/m/1 model. Our model m/m (1,b/1 was more efficient to find response and request time in between client and server. Conclusions: Our proposed simulation model validated through Java programming.

V. B. Kirubanand

2011-01-01

196

Single-atom quantum control of macroscopic mechanical oscillators  

CERN Document Server

We investigate a hybrid electro-mechanical system consisting of a pair of charged macroscopic mechanical oscillators coupled to a small ensemble of Rydberg atoms. The resonant dipole-dipole coupling between an internal atomic Rydberg transition and the mechanics allows cooling to its motional ground state with a single atom despite the considerable mass imbalance between the two subsystems. We show that the rich electronic spectrum of Rydberg atoms, combined with their high degree of optical control, paves the way towards implementing various quantum-control protocol for the mechanical oscillators.

Bariani, F; Tan, Huatang; Meystre, P

2013-01-01

197

Recent achievements in restorative neurology: Progressive neuromuscular diseases  

Energy Technology Data Exchange (ETDEWEB)

This book contains 27 chapters. Some of the chapter titles are: Computed Tomography of Muscles in Neuromuscular Disease; Mapping the Genes for Muscular Dystrophy; Trophic Factors and Motor Neuron Development; Size of Motor Units and Firing Rate in Muscular Dystrophy; Restorative Possibilities in Relation to the Pathology of Progressive Neuromuscular Disease; and An Approach to the Pathogenesis of some Congenital Myopathies.

Dimitrijevic, M.R.; Kakulas, B.A.; Vrbova, G.

1986-01-01

198

Recent achievements in restorative neurology: Progressive neuromuscular diseases  

International Nuclear Information System (INIS)

This book contains 27 chapters. Some of the chapter titles are: Computed Tomography of Muscles in Neuromuscular Disease; Mapping the Genes for Muscular Dystrophy; Trophic Factors and Motor Neuron Development; Size of Motor Units and Firing Rate in Muscular Dystrophy; Restorative Possibilities in Relation to the Pathology of Progressive Neuromuscular Disease; and An Approach to the Pathogenesis of some Congenital Myopathies

1986-01-01

199

CHRONIC NEUROMUSCULAR ELECTRICAL STIMULATION OF PARALYZED HINDLIMBS IN A RODENT MODEL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Neuromuscular electrical stimulation (NMES) can be used to activate paralyzed or paretic muscles to generate functional or therapeutic movements. The goal of this research was to develop a rodent model of NMES-assisted movement therapy after spinal cord injury (SCI) that will enable investigation of mechanisms of NMES-induced plasticity, from the molecular to systems level. Development of the model requires accurate mapping of electrode and muscle stimulation sites, the capability to selectiv...

Jung, Ranu; Ichihara, Kazuhiko; Venkatasubramanian, Ganapriya; Abbas, James J.

2009-01-01

200

Postsynaptic TRPC1 Function Contributes to BDNF-Induced Synaptic Potentiation at the Developing Neuromuscular Junction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Brain-derived neurotrophic factor (BDNF) induces synaptic potentiation at both neuromuscular junctions (NMJs) and synapses of the central nervous system through a Ca2+-dependent pathway. The molecular mechanism underlying BDNF-induced synaptic potentiation, especially the regulation of Ca2+ dynamics, is not well understood. Using the Xenopus NMJ in culture as a model system, we show that pharmacological inhibition or morpholino-mediated knockdown of Xenopus TRPC1 (XTRPC1) significantly attenu...

Mcgurk, Julie S.; Shim, Sangwoo; Kim, Ju Young; Wen, Zhexing; Song, Hongjun; Ming, Guo-li

2011-01-01

 
 
 
 
201

A novel pathway for MuSK to induce key genes in neuromuscular synapse formation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

At the developing neuromuscular junction the Agrin receptor MuSK is the central organizer of subsynaptic differentiation induced by Agrin from the nerve. The expression of musk itself is also regulated by the nerve, but the mechanisms involved are not known. Here, we analyzed the activation of a musk promoter reporter construct in muscle fibers in vivo and in cultured myotubes, using transfection of multiple combinations of expression vectors for potential signaling components. We show that n...

Lacazette, Eric; Le Calvez, Sophie; Gajendran, Nadesan; Brenner, Hans Rudolf

2003-01-01

202

Chemical mechanisms in mercury emission control technologies  

Energy Technology Data Exchange (ETDEWEB)

The emission of elemental mercury in the flue gas from coal-burning power plants is a major environmental concern. Control technologies utilizing activated carbon show promise and are currently under intense review. Oxidation and capture of elemental mercury on activated carbon was extensively investigated in a variety of flue gas atmospheres. Extensive parametric testing with individual and a variety of combinations and concentrations of reactive flue gas components and spectroscopic examination of the sulfur and chlorine forms present before and after breakthrough have led to an improved model to explain the kinetic and capacity results. The improved model delineates the independent Lewis acid oxidation site as well as a zig-zag carbene site on the carbon edge that performs as a Lewis base in reacting with both the oxidized mercury formed at the oxidation site and with the acidic flue gas components in competing reactions to form organochlorine, sulfinate, and sulfate ester moieties on the carbon edge.

Olson, E.S.; Laumb, J.D.; Benson, S.A.; Dunham, G.E.; Sharma, R.K.; Mibeck, B.A.; Miller, S.J.; Holmes, M.J.; Pavlish, J.H. [University of North Dakota, Energy and Environmental Research Center, Grand Forks, ND (United States)

2003-05-01

203

Neural Control Mechanisms and Body Fluid Homeostasis  

Science.gov (United States)

The goal of the proposed research was to study the nature of afferent signals to the brain that reflect the status of body fluid balance and to investigate the central neural mechanisms that process this information for the activation of response systems which restore body fluid homeostasis. That is, in the face of loss of fluids from intracellular or extracellular fluid compartments, animals seek and ingest water and ionic solutions (particularly Na(+) solutions) to restore the intracellular and extracellular spaces. Over recent years, our laboratory has generated a substantial body of information indicating that: (1) a fall in systemic arterial pressure facilitates the ingestion of rehydrating solutions and (2) that the actions of brain amine systems (e.g., norepinephrine; serotonin) are critical for precise correction of fluid losses. Because both acute and chronic dehydration are associated with physiological stresses, such as exercise and sustained exposure to microgravity, the present research will aid in achieving a better understanding of how vital information is handled by the nervous system for maintenance of the body's fluid matrix which is critical for health and well-being.

Johnson, Alan Kim

1998-01-01

204

The response of cortical alpha activity to pain and neuromuscular changes caused by exercise-induced muscle damage.  

Science.gov (United States)

Exercise-induced muscle damage (EIMD) is characterized by pain, swelling, and shortening of the muscle; increased serum creatine kinase; decreased force output; and altered neuromuscular function. The aim of this study was to investigate the effects of EIMD to determine the relationship between the peripheral symptoms, neuromuscular changes, and delayed pain sensation during a submaximal movement of the biceps brachii on cortical alpha (?) activity. In contrast to the control (n?=?12) group, the experimental (n?=?16) group participated in an EIMD protocol, and both groups were monitored for 132?h post-EIMD protocol. At 12?h, neuromuscular functioning was already disturbed while the sensation of pain was perceived, but not fully developed. Muscle pain scores in the experimental group peaked after 36?h with the lowest torque reported at 12?h. ?-1 activity increased significantly in the motor and somatosensory area 12?h post-EIMD while ?-2 activity increased in the contralateral fronto-central area. At 36?h, pain had further increased and neuromuscular function improved while ?-1 and ?-2 activities had decreased. We hypothesize that ?-1 activity over the motor and somatosensory cortex of the experimental group displays a compensatory increase in response to the changes in neuromuscular function during movement, while an increase in ?-2 activity is related to the suppression of pain experienced within the first 12?h. PMID:22734862

Plattner, K; Lambert, M I; Tam, N; Baumeister, J

2014-02-01

205

Implementación de la electromiografía cuantitativa para el estudio de las enfermedades neuromusculares / Implementation of quantitative electromyography for studying neuromuscular diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se implementaron métodos de análisis de la electromiografía cuantitativa, en particular los métodos de procesamiento manual de Buchthal, de descomposición de la señal electromiográfica, turns-amplitudes y el análisis espectral para obtener los valores normativos de 2 músculos de referencia, el bícep [...] s braquial y el tibial anterior, con el objetivo de utilizarlos posteriormente en la práctica asistencial en el estudio de las enfermedades neuromusculares. Se realizó un estudio transversal de 50 sujetos controles, 20 del sexo femenino, 30 del sexo masculino, con una edad promedio de 38,52 años entre 25 y 55 años. Se tomaron un total de 12 000 muestras. Se concluyó que el método de análisis de descomposición de la señal electromiográfica empleado es más factible de aplicar en la práctica asistencial que el manual de Buchthal por su eficacia y rapidez, y se obtuvieron los valores normativos de los músculos bíceps braquial y tibial anterior para los estudios de electromiografía cuantitativa Abstract in english In this research, the methods of analysis of quantitative electromyography, in particular the methods of Buchthal's manual processing, the decomposition of the electromyographic signal, the turns-amplitude analysis and the spectral analysis to obtain the normative values of two reference muscles, th [...] e brachial biceps and the anterior tibial, were implemented in order to use them later in medical practice to study neuromuscular diseases. A cross-sectional study of 50 controls aged 25-55, 20 females and 30 males, with an average age of 38.52 years old, was conducted. 12 000 samples were taken in all. It was concluded that the method analysis of decomposition of the electromyographic signal used is more feasible to be used in medical practice than Buchthal's manual method due to its efficiency and celerity. The normative values of the brachial biceps and anterior tibial muscles were obtained for the studies of quantitative electromyography

Álvarez Fiallo, Roger; Santos Anzorandía, Carlos; Medina Herrera, Esther.

206

Skeletal muscle fibrosis and stiffness increase after rotator cuff tendon injury and neuromuscular compromise in a rat model.  

Science.gov (United States)

Rotator cuff tears can cause irreversible changes (e.g., fibrosis) to the structure and function of the injured muscle(s). Fibrosis leads to increased muscle stiffness resulting in increased tension at the rotator cuff repair site. This tension influences repairability and healing potential in the clinical setting. However, the micro- and meso-scale structural and molecular sources of these whole-muscle mechanical changes are poorly understood. Here, single muscle fiber and fiber bundle passive mechanical testing was performed on rat supraspinatus and infraspinatus muscles with experimentally induced massive rotator cuff tears (Tenotomy) as well as massive tears with chemical denervation (Tenotomy?+?BTX) at 8 and 16 weeks post-injury. Titin molecular weight, collagen content, and myosin heavy chain profiles were measured and correlated with mechanical variables. Single fiber stiffness was not different between controls and experimental groups. However, fiber bundle stiffness was significantly increased at 8 weeks in the Tenotomy?+?BTX group compared to Tenotomy or control groups. Many of the changes were resolved by 16 weeks. Only fiber bundle passive mechanics was weakly correlated with collagen content. These data suggest that tendon injury with concomitant neuromuscular compromise results in extra-cellular matrix production and increases in stiffness of the muscle, potentially complicating subsequent attempts for surgical repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1111-1116, 2014. PMID:24838823

Sato, Eugene J; Killian, Megan L; Choi, Anthony J; Lin, Evie; Esparza, Mary C; Galatz, Leesa M; Thomopoulos, Stavros; Ward, Samuel R

2014-09-01

207

Acyclic cucurbit[n]uril-type molecular containers bind neuromuscular blocking agents in vitro and reverse neuromuscular block in vivo.  

Science.gov (United States)

Be my guest: two acyclic cucurbit[n]uril-type receptors that carry SO(3) (-) -groups bind tightly to several commonly used neuromuscular blocking agents, such as rocuronium, in aqueous solution as revealed by direct and competitive UV/Vis binding assays. One of these containers functions as a potent reversal agent for rocuronium-induced neuromuscular block in rats. PMID:23047893

Ma, Da; Zhang, Ben; Hoffmann, Ulrike; Sundrup, Martina Grosse; Eikermann, Matthias; Isaacs, Lyle

2012-11-01

208

?????????????????? Brown Adipsoe Tissue Differentiation and Control Mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available ?????????????????????????(???????????????????????????????????????????????????????????????????????????????BMP7 (bone morphogenetic proteins 7???????-??????(transforming growth?TGF-?????????????????????????????????????????????????????????BMP7??????????????????BMP7??PRDM16?PGC-1??????????????UCP1????????????????????????????????????????????? BMP7?PRDM16 ?????????????????????????????????????????????????–???????????????(?X-????????(18F-FDG-PET/CT????????????????????????????????????????????????????????????????????Humans and other mammals have two main adipose tissue depots: white adipose tissue (include visceral- and subcutaneous- white adipose tissue, and brown adipose tissue, each of which possesses unique cell-autonomous properties. In contrast to visceral adipose tissue, which can induce detrimental metabolic ef-fects, subcutaneous white adipose tissue and brown adipose tissue have the potential to benefit metabolism by improving glucose homeostasis and increasing energy consumption. BMP7 (bone morphogenetic proteins7 is one of members of the transforming growth factor-? (TGF-? superfamily and control multiple key steps of embryonic development and differentiation. In recent studies, people found that BMP7-induced UCP1 ex-pression was markedly diminished in brown preadipocytes deficient in both PRDM16 and PGC (PGC-1? and PGC-1?, it ultimately induces BAT mitochondrial cells in the biological production and cell differentiation. There are two ways in development of brown adipose tissue. These researches indicate the potential to treat obesity and related diseases through activating BMP7 and PRDM16 to produce brown adipose tissue. Re-cently, using 18F-fluorodeoxyglucose (18F-FDG positron-emission tomographic and computed tomographic (PET-CT scans showed that adults retain metabolically active BAT depots that can be induced in response to cold and sympathetic nervous system activation. These findings high light BAT as a potenial relevant tar get for pharmacological and gene expression manipulation to combat human obesity. We reviewed the recent re-search progresses of BAT in human and its potential functional significance.

??

2011-12-01

209

Cyclic movement pin mechanism for controlling a nuclear reactor  

International Nuclear Information System (INIS)

This invention concerns a recurring movement pin mechanism for controlling a nuclear reactor by shifting a neutron absorbing assembly, vertically mobile in the nuclear reactor, to adjust the power and for emergency shut-down. This mechanism ensures a continuous movement and accurate shut-down at any level of the travel height of the absorbing assembly in the core. It also prevents the impacts of the pivoting pins in the control rod slots

1981-01-01

210

Combined application of neuromuscular electrical stimulation and voluntary muscular contractions.  

Science.gov (United States)

Electromyostimulation (EMS) and voluntary muscle contraction (VC) constitute different modes of muscle activation and induce different acute physiological effects on the neuromuscular system. Long-term application of each mode of muscle activation can produce different muscle adaptations. It seems theoretically possible to completely or partially cumulate the muscle adaptations induced by each mode of muscle activation applied separately. This work consisted of examining the literature concerning the muscle adaptations induced by long-term application of the combined technique (CT) [i.e. EMS is combined with VC - non-simultaneously] compared with VC and/or EMS alone in healthy subjects and/or athletes and in post-operative knee-injured subjects. In general, CT induced greater muscular adaptations than VC whether in sports training or rehabilitation. This efficiency would be due to the fact that CT can facilitate cumulative effects of training completely or partially induced by VC and EMS practiced alone. CT also provides a greater improvement of the performance of complex dynamic movements than VC. However, EMS cannot improve coordination between different agonistic and antagonistic muscles and thus does not facilitate learning the specific coordination of complex movements. Hence, EMS should be combined with specific sport training to generate neuromuscular adaptations, but also allow the adjustment of motor control during a voluntary movement. Likewise, in a therapeutic context, CT was particularly efficient to accelerate recovery of muscle contractility during a rehabilitation programme. Strength loss and atrophy inherent in a traumatism and/or a surgical operation would be more efficiently compensated with CT than with VC. Furthermore, CT also restored more functional abilities than VC. Finally, in a rehabilitation context, EMS is complementary to voluntary exercise because in the early phase of rehabilitation it elicits a strength increase, which is necessary to perform voluntary training during the later rehabilitation sessions. PMID:18201117

Paillard, Thierry

2008-01-01

211

Diagnosis of Neuromuscular Disorders Using Softcomputing Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available Biomedical signals are collection of electrical signals which generated from any organ that signal represents a physical variable of interest. Electromyography (EMG is a technique for evaluating and recording of electrical activities produced from skeletal muscles. There are so many applications of EMG signals. Major interests lies in the field of clinical as well as biomedical engineering.EMG is used as a diagnostic tool for identifying neuromuscular disorders .Motor unit action potentials (MUPS provides information about neuromuscular disorders. Traditionally neurophysiologist can access MUPs information from their shapes and patterns using an oscilloscope. But MUPs from different motor neurons will overlap leads to the formation of interference pattern and it is difficult to detect individual shapes accurately. For this reason a number of computer based quantitative EMG analysis algorithm have been developed. In this work, different types of learning methods were used to classify EMG signals. The model automatically classifies EMG signals into normal, myopathy and neuropathy. In order to extract useful information from the EMG signals different feature extraction methods such as discrete wavelet transform(DWT and auto regressive modeling(ARare implemented. Adaptive neuro-fuzzy inference system (ANFIS with hybrid learning algorithm, support vector machine (SVM and fuzzy support vector machine (FSVM were compared in relation to their accuracy in the classification of EMG signals. Based on the impacts of features on the EMG signal classification, different results were obtained through analysis of the soft computing techniques.

Akhila Devi.B.V

2013-11-01

212

Electrophysiological study in neuromuscular junction disorders.  

Science.gov (United States)

This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG) helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS). SFEMG requires skill and patience and its availability is limited to a few centers. For RNS supramaximal stimulation is essential and so is display of the whole waveform of each muscle response at maximum amplitude. The amplitudes of the negative phase of the first and fourth responses are measured from baseline to negative peak, and the percent change of the fourth response compared with the first represents the decrement or increment. A decrement greater than 10% is accepted as abnormal and smooth progression of response amplitude train and reproducibility form the crux. In suspected LEMS the effect of fast rates of stimulation should be determined after RNS response to slow rates of stimulation. Caution is required to avoid misinterpretation of potentiation and pseudofacilitation. PMID:23661960

Cherian, Ajith; Baheti, Neeraj N; Iype, Thomas

2013-01-01

213

Electromyographic responses at the neuromuscular fatigue threshold.  

Science.gov (United States)

The purposes of this investigation were to: (a) examine the electromyographic (EMG) responses from the vastus lateralis during a continuous ride to exhaustion at the neuromuscular fatigue threshold (EMGFT) and (b) determine what percentage of the power output at VO2max the EMGFT represents. Fifteen adult males (mean +/- SD = 22 +/- 2 years) volunteered to perform an EMGFT test and a continuous ride to exhaustion at the EMGFT on separate days. A subsample of ten subjects completed an incremental cycle ergometer test for the determination of VO2max. The mean (+/- SD) EMGFT for the total sample (n = 15) was 286 +/- 40W and the mean time to exhaustion at the EMGFT was 250 +/- 85 sec. For each subject, the slope of the iEMG versus time relationship during the continuous ride to exhaustion at the EMGFT was significantly (p 0.05) different from the power output at VO2max (282 +/- 47W). These findings did not support the contention that the EMGFT can be sustained without electromyographic evidence of neuromuscular fatigue and indicated that the EMGFT was comparable to the power output at VO2max. PMID:7474990

Pavlat, D J; Housh, T J; Johnson, G O; Eckerson, J M

1995-03-01

214

Mechanics and model-based control of advanced engineering systems  

CERN Multimedia

Mechanics and Model-Based Control of Advanced Engineering Systems collects 32 contributions presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines, which took place in St. Petersburg, Russia in July 2012. The workshop continued a series of international workshops, which started with a Japan-Austria Joint Workshop on Mechanics and Model Based Control of Smart Materials and Structures and a Russia-Austria Joint Workshop on Advanced Dynamics and Model Based Control of Structures and Machines. In the present volume, 10 full-length papers based on presentations from Russia, 9 from Austria, 8 from Japan, 3 from Italy, one from Germany and one from Taiwan are included, which represent the state of the art in the field of mechanics and model based control, with particular emphasis on the application of advanced structures and machines.

Irschik, Hans; Krommer, Michael

2014-01-01

215

Metabolic syndrome: aggression control mechanisms gone out of control.  

Science.gov (United States)

An upcoming hypothesis about the evolutionary origins of metabolic syndrome is that of a 'soldier' to 'diplomat' transition in behaviour and the accompanying metabolic adaptations. Theoretical as well as empirical studies have shown that similar to the soldier and diplomat dichotomy, physically aggressive and non-aggressive strategists coexist in animal societies with negative frequency dependent selection. Although dominant individuals have a higher reproductive success obtained through means such as greater access to females, subordinate individuals have alternative means such as sneak-mating for gaining a substantial reproductive success. The alternative behavioural strategies are associated with different neurophysiologic and metabolic states. Subordinate individuals typically have low testosterone, high plasma cholesterol and glucocorticoids and elevated serotonin signalling whereas dominant ones are characterized by high testosterone, low brain serotonin and lower plasma cholesterol. Food and sex are the main natural causes of aggression. However, since aggression increases the risk of injury, aggression control is equally crucial. Therefore chronic satiety in the form of fat should induce aggression control. It is not surprising that the satiety hormone serotonin has a major role in aggression control. Further chronically elevated serotonin signalling in the hypothalamus induces peripheral insulin resistance. Meta-analysis shows that most of the anti-aggression signal molecules are pro-obesity and pro-insulin-resistance. Physical aggression is known to increase secretion of epidermal growth factor (EGF) in anticipation of injuries and EGF is important in pancreatic beta cell regeneration too. In anticipation of injuries aggression related hormones also facilitate angiogenesis and angiogenesis dysfunction is the root cause of a number of co-morbidities of insulin resistance syndrome. Reduced injury proneness typical of 'diplomat' life style would also reorient the immune system resulting into delayed wound healing on the one hand and increased systemic inflammation on the other. Diabetes is negatively associated with physically aggressive behaviour. We hypothesize that suppression of physical aggression is the major behavioural cue for the development of metabolic syndrome. Preliminary trials of behavioural intervention indicate that games and exercises involving physical aggression reduce systemic inflammation and improve glycemic control. PMID:19800745

Belsare, Prajakta V; Watve, Milind G; Ghaskadbi, Saroj S; Bhat, Dattatraya S; Yajnik, Chittaranjan S; Jog, Maithili

2010-03-01

216

The effects of neuromuscular electrical stimulation for dysphagia in opercular syndrome: a case study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 76-year-old man with opercular syndrome characterized by complete bilateral loss of voluntary control of facial, lingual, pharyngeal and masticatory muscles is presented with focus on the severe dysphagia. Three years earlier the patient had experienced two strokes resulting in opercular syndrome with severe dysphagia. Despite initial logopedic dysphagia treatment, swallowing did not improve. A new treatment for dysphagia, consisting of neuromuscular electrical stimulation was applied on th...

Baijens, Laura W. J.; Speyer, Rene?e; Roodenburg, Nel; Manni, Johannes J.

2008-01-01

217

Cross-training effects of a proprioceptive neuromuscular facilitation exercise programme on knee musculature  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objectives: To examine the cross-training effects of a proprioceptive neuromuscular facilitation training (PNF) program on peak torque and endurance. Design: Factorial design. Participants: Twenty-three males were assigned to a PNF group (n=12) or a control group (n=11). Interventions: The PNF program included training of the knee extensor and flexor muscles for a period of 8 weeks, exercising three times a week. PNF training included performance of knee movements through range of motion agai...

Kofotolis, N. D.; ??????????, ?. ?.; Kellis, E.; ???????, ?.

2010-01-01

218

RIM Promotes Calcium Channel Accumulation at Active Zones of the Drosophila Neuromuscular Junction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Synaptic communication requires the controlled release of synaptic vesicles from presynaptic axon terminals. Release efficacy is regulated by the many proteins that comprise the presynaptic release apparatus, including Ca2+ channels and proteins that influence Ca2+ channel accumulation at release sites. Here we identify Drosophila RIM and demonstrate that it localizes to active zones at the larval neuromuscular junction. In Drosophila RIM mutants, there is a large decrease in evoked synaptic ...

Graf, Ethan R.; Valakh, Vera; Wright, Christina M.; Wu, Chunlai; Liu, Zhihua; Zhang, Yong Q.; Diantonio, Aaron

2012-01-01

219

Neuromuscular performance and knee laxity do not change across the menstrual cycle in female athletes.  

Science.gov (United States)

Female athletes incur anterior cruciate ligament ruptures at a rate at least twice that of male athletes. Hypothesized factors for the increased injury risk in females include biomechanical, neuromuscular, and hormonal differences between genders. A wealth of literature exists examining these potential predispositions individually, but the interactions between these factors have not been examined extensively. Our purpose was to investigate changes in neuromuscular control and laxity at the knee across the menstrual cycle of healthy females. Fourteen female collegiate athletes with normal, documented ovulatory menstrual cycles, confirmed ovulation, and no history of serious knee injury participated. The presence and timing of ovulation was determined during a screening cycle with ovulation detection kits and during an experimental cycle with collection of daily urine samples and subsequent analysis of urinary estrone-3-glucuronide (E3G) and pregnanediol-3-glucoronide (PdG), which correlate with circulating estrogen and progesterone. Each subject had measures of knee neuromuscular performance and laxity once during the mid-follicular, ovulatory, and mid-luteal stages of her menstrual cycle. The test battery included assessments of knee flexion and extension peak torque, passive knee joint position sense, and postural control in single leg stance. Knee joint laxity was measured with an arthrometer. Analyses of variance revealed that E3G and PdG levels were significantly different across the three testing sessions, but there were no significant differences in the measures of strength, joint position sense, postural control, or laxity. No significant correlations were found between changes in E3G or PdG levels and changes in the performance and laxity measures between sessions. These results suggest that neuromuscular control and knee joint laxity do not change substantially across the menstrual cycle of females despite varying estrogen and progesterone levels. PMID:16470385

Hertel, Jay; Williams, Nancy I; Olmsted-Kramer, Lauren C; Leidy, Heather J; Putukian, Margot

2006-09-01

220

Gender differences exist in neuromuscular control patterns during the pre-contact and early stance phase of an unanticipated side-cut and cross-cut maneuver in 15-18 years old adolescent soccer players.  

Science.gov (United States)

Non-contact ACL injuries generally occur as the foot contacts the ground during cutting or landing maneuvers and the non-contact ACL injury rate is 2-8 times greater in females compared to males. To provide insight into the gender bias of this injury, this study set out to identify gender differences in the neuromuscular response of the quadriceps, hamstrings and gastrocnemii muscles in elite adolescent soccer players during the pre-contact and early stance phases of an unanticipated side-cut and cross-cut. For the early stance phase of the two maneuvers, females demonstrated greater rectus femoris activity compared to males. Throughout the pre-contact phase of the maneuvers, a rectus femoris activation difference was identified with females having an earlier and more rapid rise in muscle activity as initial ground contact approached. Females demonstrated greater lateral and medial gastrocnemii activity for the pre-contact and early stance phases of the side-cut and greater lateral gastrocnemii activity during early stance of the cross-cut. Timing of hamstring activity also differed between genders prior to foot contact. The differences suggest that the activation patterns observed in females might not be providing adequate joint protection and stability, thereby possibly having a contributing role towards increased non-contact ACL injuries in females. PMID:18938089

Landry, Scott C; McKean, Kelly A; Hubley-Kozey, Cheryl L; Stanish, William D; Deluzio, Kevin J

2009-10-01

 
 
 
 
221

Single-atom quantum control of macroscopic mechanical oscillators  

Science.gov (United States)

We investigate a hybrid electromechanical system consisting of a pair of charged macroscopic mechanical oscillators coupled to a small ensemble of Rydberg atoms. The resonant dipole-dipole coupling between an internal atomic Rydberg transition and the mechanics allows cooling to its motional ground state with a single atom despite the considerable mass imbalance between the two subsystems. We show that the rich electronic spectrum of Rydberg atoms, combined with their high degree of optical control, paves the way towards implementing various quantum-control protocols for the mechanical oscillators.

Bariani, F.; Otterbach, J.; Tan, Huatang; Meystre, P.

2014-01-01

222

The influence of gender on neuromuscular pre-activity during side-cutting  

DEFF Research Database (Denmark)

It is well established that female athletes are at increased risk for sustaining ACL injuries in sports, where sudden changes of direction are a frequent movement pattern. The underlying neuromuscular mechanisms related to the elevated ACL injury rate in female athletes has yet to be fully investigated. This cross-sectional study aimed to examine gender differences in neuromuscular pre-activity during a maneuver that mimics a movement associated with the incidence of ACL injuries. Twenty-four team handball players (12 male and 12 female) with no history of ACL injury were tested for EMG pre-activity of vastus lateralis, vastus medialis, semitendinosus, and biceps femoris during a side-cutting maneuver. Mean EMG amplitude 50ms prior to toe down was normalized to maximal EMG obtained during maximal isometric contraction. The results showed that females had significantly lower hamstring EMG pre-activity 50ms prior to toe-down than males (P

Zebis, Mette K

2011-01-01

223

System defense mechanisms in nuclear power generation control computers  

International Nuclear Information System (INIS)

Dual-redundant computers are used to control and monitor the production of power from Ontario Hydro's nuclear power reactors. Each computer must have the capability of monitoring its own performance and detecting faults. Upon fault detection, each computer must initiate corrective responses to ensure the integrity of critical control functions. This paper reviews those features the authors have termed system defense mechanisms

1985-01-01

224

Evaluation of skeletal muscular involvement in neuromuscular disorders with thallium-201 whole body scintigraphy  

International Nuclear Information System (INIS)

The extent as well as severity of pathologic changes of skeletal muscles were analyzed with thallium-201 whole body scintigraphy (WBS) in 29 cases of various types of neuromuscular diseases (18 cases of myogenic and 11 cases of neurogenic muscular diseases) and 14 cases of normal controls. After intravenous injection of 2 mCi of thallium-201 chloride, WBS was performed for 15 minutes using a gamma camera with twin-opposed large rectangular detectors. Counts at brachia, forearms, thighs, and calves were assessed after reconstruction of the scintigram of the whole body by taking the geometric mean of the anterior and posterior data. WBS showed uniform tracer activities in the 4 extremities in 12 cases among 14 controls. Laterality in distribution of counts of both legs and arms was noted in the remaining 2 controls. WBS revealed decrease of perfusion in the extremities with muscular atrophy and/or weakness in neuromuscular diseases. The overall diagnostic accuracy of WBS for evaluation of skeletal muscle involvement was 75 to 80 % except for the bilateral brachia for which it decreased to 65 %. All of the three cases of muscular dystrophy with pseudohypertrophy of the calves or thighs showed unequivocal decrease of perfusion of those regions in WBS. In conclusion, thallium-201 WBS was considered to be a useful clinical means in evaluating the extent and severity of muscular involvement of various types of neuromuscular disorders. (author)

1986-01-01

225

Consecuencias clínicas de las alteraciones neuromusculares en el paciente crítico / Clinical consequences of neuromuscular impairments in critically ill patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish La patología neuromuscular en el paciente crítico se desarrolla en dos contextos: enfermedades neurológicas primarias que requieren su ingreso en Medicina Intensiva por necesitar vigilancia estricta o ventilación mecánica y manifestaciones del sistema nervioso periférico secundarias a enfermedades s [...] istémicas críticas. En el primer grupo son las más frecuentes el Síndrome de Guillain-Barré y la Miastenia Gravis y en el segundo la Polineuropatía y la Miopatía del paciente crítico. El patrón clínico común más frecuente consiste en el desarrollo de un cuadro de acusada debilidad y cuadriparesia cuya manifestación más típica es la necesidad de respiración asistida o la dificultad/imposibilidad para su retirada. Se consideran factores desencadenantes el fracaso multiorgánico y la sepsis en la polineuropatía y los esteroides y bloqueantes neuromusculares en la miopatía, actuando como coadyuvantes en ambos casos la malnutrición, particularmente la hipoalbimunemia, y la hiperglucemia. Considerando que la afectación neuropática y miopática coexisten con frecuencia, se ha acuñado el término polineuromiopatía del paciente crítico. Tanto el Síndrome de Guillain-Barré como la polineuropatía del paciente crítico se localizan a nivel del nervio periférico, por lo que debe efectuarse un diagnóstico diferencial entre ambos. La forma de presentación es diferente ya que el primero es una patología aguda que motiva su ingreso en UCI, mientras que la polineuropatía se adquiere durante la hospitalización. En el primero es frecuente la afectación del sistema nervioso autónomo y la disociación albúmino-citológica en el LCR, lo que no se da en la polineuropatía. Los estudios electrofisiológicos muestran signos de desmelinización con disminución de la velocidad de conducción y normalidad en la amplitud de potenciales motores en el Síndrome de Guillain- Barré frente a velocidad de conducción normal y amplitud reducida de potenciales motores en la polineuropatía axonal. La crisis miasténica afecta a la unión neuromuscular y su diagnóstico suele ser más fácil al tener en la mayoría de los casos un diagnóstico previo de miastenia gravis.La debilidad muscular aumenta durante la actividad repetida (fatiga muscular) y mejora con el reposo. Su confirmación diagnóstica se realiza con el test del edofronio y con la estimulación nerviosa repetitiva, que provoca una rápida disminución del 10-15% en la amplitud de las respuestas provocadas. La miopatía del paciente crítico se localiza en el músculo y provoca una debilidad generalizada con cuadriparesia, muy similar a la de la polineuropatía, que impide o retrasa la desconexión de la ventilación mecánica y que en sus grados avanzados puede provocar un aumento de CPK y mioglobina, junto con alteraciones en la exploración neurofisiológica. Esta última es difícil de discernir de la encontrada en la polineuropatía, aunque la normalidad en los potenciales de acción sensitiva y la redución en el potencial de ación motora con estimulación muscular directa, puede ayudar a diferenciarlos. El pronóstico funcional de las alteraciones musculares primarias suele ser bastante bueno, pero tanto la polineuropatía como la miopatía evolucionan lentamente a lo largo de semanas o meses, pudiendo quedar un importante déficit residual a los dos años en los casos más graves. Abstract in english Neuromuscular pathology in the critically ill patient develops within two settings: primary neurological diseases that require admission in the Intensive Care Medicine Unit for close monitoring or mechanical ventilation, and peripheral nervous system manifestations secondary to critical systemic dis [...] eases. The most frequent conditions in the first group are Guillain-Barré syndrome and Myasthenia Gravis, and in the second group, polyneuropathy and myopathy of the critically ill patient. The most commonly shared clinical pattern is the development of severe weakness and

Mesejo, A.; Pérez-Sancho, E.; Moreno, E..

226

Consecuencias clínicas de las alteraciones neuromusculares en el paciente crítico Clinical consequences of neuromuscular impairments in critically ill patients  

Directory of Open Access Journals (Sweden)

Full Text Available La patología neuromuscular en el paciente crítico se desarrolla en dos contextos: enfermedades neurológicas primarias que requieren su ingreso en Medicina Intensiva por necesitar vigilancia estricta o ventilación mecánica y manifestaciones del sistema nervioso periférico secundarias a enfermedades sistémicas críticas. En el primer grupo son las más frecuentes el Síndrome de Guillain-Barré y la Miastenia Gravis y en el segundo la Polineuropatía y la Miopatía del paciente crítico. El patrón clínico común más frecuente consiste en el desarrollo de un cuadro de acusada debilidad y cuadriparesia cuya manifestación más típica es la necesidad de respiración asistida o la dificultad/imposibilidad para su retirada. Se consideran factores desencadenantes el fracaso multiorgánico y la sepsis en la polineuropatía y los esteroides y bloqueantes neuromusculares en la miopatía, actuando como coadyuvantes en ambos casos la malnutrición, particularmente la hipoalbimunemia, y la hiperglucemia. Considerando que la afectación neuropática y miopática coexisten con frecuencia, se ha acuñado el término polineuromiopatía del paciente crítico. Tanto el Síndrome de Guillain-Barré como la polineuropatía del paciente crítico se localizan a nivel del nervio periférico, por lo que debe efectuarse un diagnóstico diferencial entre ambos. La forma de presentación es diferente ya que el primero es una patología aguda que motiva su ingreso en UCI, mientras que la polineuropatía se adquiere durante la hospitalización. En el primero es frecuente la afectación del sistema nervioso autónomo y la disociación albúmino-citológica en el LCR, lo que no se da en la polineuropatía. Los estudios electrofisiológicos muestran signos de desmelinización con disminución de la velocidad de conducción y normalidad en la amplitud de potenciales motores en el Síndrome de Guillain- Barré frente a velocidad de conducción normal y amplitud reducida de potenciales motores en la polineuropatía axonal. La crisis miasténica afecta a la unión neuromuscular y su diagnóstico suele ser más fácil al tener en la mayoría de los casos un diagnóstico previo de miastenia gravis.La debilidad muscular aumenta durante la actividad repetida (fatiga muscular y mejora con el reposo. Su confirmación diagnóstica se realiza con el test del edofronio y con la estimulación nerviosa repetitiva, que provoca una rápida disminución del 10-15% en la amplitud de las respuestas provocadas. La miopatía del paciente crítico se localiza en el músculo y provoca una debilidad generalizada con cuadriparesia, muy similar a la de la polineuropatía, que impide o retrasa la desconexión de la ventilación mecánica y que en sus grados avanzados puede provocar un aumento de CPK y mioglobina, junto con alteraciones en la exploración neurofisiológica. Esta última es difícil de discernir de la encontrada en la polineuropatía, aunque la normalidad en los potenciales de acción sensitiva y la redución en el potencial de ación motora con estimulación muscular directa, puede ayudar a diferenciarlos. El pronóstico funcional de las alteraciones musculares primarias suele ser bastante bueno, pero tanto la polineuropatía como la miopatía evolucionan lentamente a lo largo de semanas o meses, pudiendo quedar un importante déficit residual a los dos años en los casos más graves.Neuromuscular pathology in the critically ill patient develops within two settings: primary neurological diseases that require admission in the Intensive Care Medicine Unit for close monitoring or mechanical ventilation, and peripheral nervous system manifestations secondary to critical systemic diseases. The most frequent conditions in the first group are Guillain-Barré syndrome and Myasthenia Gravis, and in the second group, polyneuropathy and myopathy of the critically ill patient. The most commonly shared clinical pattern is the development of severe weakness and quadriplegia which most typical manifestation is the need for assisted ventilation and/or

A. Mesejo

2006-05-01

227

Monolithic Controlled Delivery Systems: Part I. Basic Characteristics and Mechanisms  

Directory of Open Access Journals (Sweden)

Full Text Available The article considers contemporary systems for controlled delivery of active agents, such as drugs, agricultural chemicals, pollutants and additives in the environment. A useful classification of the available controlled release systems (CRS is proposed according to the type of control (passive, active or self-preprogrammed and according to the main controlling mechanism (diffusion, swelling, dissolution or erosion. Special attention is given to some of the most used CRS - polymer monoliths. The structural and physical-chemical characteristics of CRS as well as the basic approaches to their production are examined. The basic mechanisms of controlled agent release are reviewed in detail and factors influencing the release kinetics are classified according to their importance. The present study can be helpful for understanding and applying the available mathematical models and for developing more comprehensive ones intended for design of new controlled delivery systems.

Rumiana Blagoeva

2006-04-01

228

Soft Time-Suboptimal Controlling Structure for Mechanical Systems  

DEFF Research Database (Denmark)

The paper presents conception of a soft control structure based on the time-optimal approach. Its parameters are selected in accordance with the rules of the statistical decision theory and additionally it allows to eliminate rapid changes in control values. The object is a basic mechanical system, with uncertain (also non-stationary) mass treated as a stochastic process. The methodology proposed here is of a universal nature and may easily be applied with respect to other uncertainty elements of timeoptimal controlled mechanical systems.

Kulczycki, Piotr; Wisniewski, Rafal

2004-01-01

229

Surgical advances in the treatment of neuromuscular scoliosis.  

Science.gov (United States)

Neuromuscular disorders are a group of diseases affecting the neuro-musculo-skeletal system. Children with neuromuscular disorders frequently develop progressive spinal deformities with cardio-respiratory compromise in the most severe cases. The incidence of neuromuscular scoliosis is variable, inversely correlated with ambulatory abilities and with a reported risk ranging from 80% to 100% in non-ambulatory patients. As surgical and peri-operative techniques have improved, more severely affected children with complex neuromuscular deformities and considerable co-morbidities are now believed to be candidates for extensive surgery for spinal deformity. This article aimed to provide a comprehensive review of how neuromuscular spinal deformities can affect normal spine balance and how these deformities can be treated with segmental instrumentation and sub-laminar devices. Older concepts have been integrated with newer scientific data to provide the reader with a basis for better understanding of how treatment of neuromuscular scoliosis has evolved over the past few decades. Recent advances, as well as challenges that remain to be overcome, in the surgical treatment of neuromuscular curves with sub-laminar devices and in the management of post-operative infections are outlined. PMID:24829875

Canavese, Federico; Rousset, Marie; Le Gledic, Benoit; Samba, Antoine; Dimeglio, Alain

2014-04-18

230

Neuromuscular blockade in cardiac surgery: An update for clinicians  

Directory of Open Access Journals (Sweden)

Full Text Available There have been great advancements in cardiac surgery over the last two decades; the widespread use of off-pump aortocoronary bypass surgery, minimally invasive cardiac surgery, and robotic surgery have also changed the face of cardiac anaesthesia. The concept of "Fast-track anaesthesia" demands the use of nondepolarising neuromuscular blocking drugs with short duration of action, combining the ability to provide (if necessary sufficiently profound neuromuscular blockade during surgery and immediate re-establishment of normal neuromuscular transmission at the end of surgery. Postoperative residual muscle paralysis is one of the major hurdles for immediate or early extubation after cardiac surgery. Nondepolarising neuromuscular blocking drugs for cardiac surgery should therefore be easy to titrate, of rapid onset and short duration of action with a pathway of elimination independent from hepatic or renal dysfunction, and should equally not affect haemodynamic stability. The difference between repetitive bolus application and continuous infusion is outlined in this review, with the pharmacodynamic and pharmacokinetic characteristics of vecuronium, pancuronium, rocuronium, and cisatracurium. Kinemyography and acceleromyography are the most important currently used neuromuscular monitoring methods. Whereas monitoring at the adductor pollicis muscle is appropriate at the end of surgery, monitoring of the corrugator supercilii muscle better reflects neuromuscular blockade at more central, profound muscles, such as the diaphragm, larynx, or thoraco-abdominal muscles. In conclusion, cisatracurium or rocuronium is recommended for neuromuscular blockade in modern cardiac surgery.

Hemmerling Thomas

2008-01-01

231

Quantitative quality control for mechanical isocenter in teletherapy  

International Nuclear Information System (INIS)

Teletherapy devices have a non point mechanical isocenter which can influence the quality of care and therefore, quality control protocols were established to evaluate this parameter. This work aims to create a method for measuring the mechanical isocenter to be made an assessment and validation of equipment. It used a mechanical ensemble, where the main component is a gauge, for measuring the size of a precision piece. The difference between the known and measured value is attributed to mechanical instability of the device in question. (author)

2009-07-08

232

Research on Internal Flow Control Mechanism of For CES Routers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To improve the communication efficiency and security between Control Elements (CEs) and Forwarding Elements (FEs) of For CES routers, this study researches on internal flow control mechanism. Firstly, an evaluation model based on communication of Transport Mapping Layer (TML) is proposed, which is used to improve service performance of TML. Secondly, in order to prevent redirect channel interference with control channel, this study proposes a bandwidth allocation algorithm called Dynamic Prob...

Bin Zhuge; Cheng Yu; Kang-ping Liu; Wei-ming Wang

2011-01-01

233

A systematic literature review on the use of proprioceptive neuromuscular facilitation in neuromuscular rehabilitation  

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The purpose of this thesis was to review and critically analyze the literatures from 1990 to 2013 in order to investigate the methodological quality of the studies, indications and goals of PNF treatment, and to explore the components of PNF that are being used in treatment of neurological disorders. And to overview on the effectiveness and use of PNF approach in neuromuscular rehabilitation through the findings of this study.

Shrestha, Yugal

2013-01-01

234

Ação neuro-muscular do veneno crotálico: dados preliminares / Neuromuscular action of crotalid venom: preliminar data  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudamos 6 pacientes, 2 cães e um coelho com intoxicação crotálica. Avaliamos a condução nervosa periférica sensitiva e motora, a transmissão neuromuscular e eletromiografias. As biópsias de músculo foram processadas por histoquímica. Os 6 pacientes apresentaram mononeuropatia sensitiva no nervo pe [...] riférico adjacente ao local da inoculação do veneno e encontramos evidências histoquímicas de miopatia mitocondrial. Os defeitos da transmissão neuromuscular foram mínimos. A maioria dos autores admite que veneno crotálico determina síndrome miastênica. Nossos achados indicam que ptose palpebral, facies miastênico e fraqueza muscular observados após acidente crotálico, correspondem provavelmente a miopatia mitocondrial, muitas vezes transitória e reversível. Abstract in english We studied 6 patients and 2 dogs that have been bitten by South American rattlesnake Crotalus durissus terrificus and one rabbit inoculated with crotalid venom. We analized sensory and motor peripheral nerve conduction, repetitive stimulation for studying neuromuscular transmission and electromyogra [...] phies. Muscle biopsies were processed by histochemistry. All patients had peripheral mononeuropathy of the closest sensitive nerve to the area of snakebite. The neuromuscular transmission alterations were minimal. Muscle histochemistry of 4 patients, 2 dogs and 1 rabbit showed findings of mitochondrial myopathy. The majority of authors admit that crotalid venom causes myastenic syndrome. Our findings suggest that palpebral ptosis, myastenic facies and muscular weakness observed after crotalid poisoning are, probably, due to transient and reversible mitochondrial myopathy. As far as we know, this is the first report on the ability of the venom of this rattlesnake to cause local sensitive mononeuropathy and the first muscle histochemistry showing mitochondrial myopathy in humans poisoned by crotalid venom.

Maria Dorvalina, Silva; Luiz Antônio L., Resende; Anete Kimuni, Ueda; Benedito, Barraviera; R.P., Mendes; Mário Rubens G., Montenegro.

235

Ação neuro-muscular do veneno crotálico: dados preliminares Neuromuscular action of crotalid venom: preliminar data  

Directory of Open Access Journals (Sweden)

Full Text Available Estudamos 6 pacientes, 2 cães e um coelho com intoxicação crotálica. Avaliamos a condução nervosa periférica sensitiva e motora, a transmissão neuromuscular e eletromiografias. As biópsias de músculo foram processadas por histoquímica. Os 6 pacientes apresentaram mononeuropatia sensitiva no nervo periférico adjacente ao local da inoculação do veneno e encontramos evidências histoquímicas de miopatia mitocondrial. Os defeitos da transmissão neuromuscular foram mínimos. A maioria dos autores admite que veneno crotálico determina síndrome miastênica. Nossos achados indicam que ptose palpebral, facies miastênico e fraqueza muscular observados após acidente crotálico, correspondem provavelmente a miopatia mitocondrial, muitas vezes transitória e reversível.We studied 6 patients and 2 dogs that have been bitten by South American rattlesnake Crotalus durissus terrificus and one rabbit inoculated with crotalid venom. We analized sensory and motor peripheral nerve conduction, repetitive stimulation for studying neuromuscular transmission and electromyographies. Muscle biopsies were processed by histochemistry. All patients had peripheral mononeuropathy of the closest sensitive nerve to the area of snakebite. The neuromuscular transmission alterations were minimal. Muscle histochemistry of 4 patients, 2 dogs and 1 rabbit showed findings of mitochondrial myopathy. The majority of authors admit that crotalid venom causes myastenic syndrome. Our findings suggest that palpebral ptosis, myastenic facies and muscular weakness observed after crotalid poisoning are, probably, due to transient and reversible mitochondrial myopathy. As far as we know, this is the first report on the ability of the venom of this rattlesnake to cause local sensitive mononeuropathy and the first muscle histochemistry showing mitochondrial myopathy in humans poisoned by crotalid venom.

Maria Dorvalina Silva

1996-03-01

236

Immunoglobulins from Animal Models of Motor Neuron Disease and from Human Amyotrophic Lateral Sclerosis Patients Passively Transfer Physiological Abnormalities to the Neuromuscular Junction  

Science.gov (United States)

Amyotrophic lateral sclerosis (ALS) is a devastating human disease of upper and lower motoneurons of unknown etiology. In support of the potential role of autoimmunity in ALS, two immune-mediated animal models of motoneuron disease have been developed that resemble ALS with respect to the loss of motoneurons, the presence of IgG within motoneurons and at the neuromuscular junction, and with respect to altered physiology of the motor nerve terminal. To provide direct evidence for the primary role of humoral immunity, passive transfer with immunoglobulins from the two animal models and human ALS was carried out. Mice injected with serum or immunoglobulins from the animal disease models and human ALS but not controls demonstrated IgG in motoneurons and at the neuromuscular junction. The mice also demonstrated an increase in miniature end-plate potential (mepp) frequency, with normal amplitude and time course and normal resting membrane potential, indicating an increased resting quantal release of acetylcholine from the nerve terminal. The ability to transfer motoneuron dysfunction with serum immunoglobulins provides evidence for autoimmune mechanisms in the pathogenesis of both the animal models and human ALS.

Apel, Stanley H.; Engelhardt, Jozsef I.; Garcia, Jesus; Stefani, Enrico

1991-01-01

237

Synthesis of dissipative output feedback controllers. Application to mechanical systems  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents new results on the synthesis of linear controllers with passivity, or more general, dissipativity properties. These methods may be applied to obtain more accurate control over mechanical systems and in the control of chemical processes that involve dissipative subsystems. The thesis presents two different approaches for synthesis of dissipative controllers: (1) A method that exploits the Riccati equation solution to the state space formulation of the H{sub {infinity}} control problem is investigated, illustrated by synthesising a controller for damping of flexible modes in a beam. (2) A more general method for dissipative control synthesis is developed that retains the well-known techniques of loop-shaping and frequency weighting in H{sub {infinity}}. A method is also presented for controller synthesis directly from frequency response data. 82 refs., 34 figs., 3 tabs.

Johannessen, Erling Aarsand

1997-12-31

238

The action of polymyxin B at the frog neuromuscular junction.  

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1 The effects of polymyxin B at the neuromuscular junction of the frog were studied by conventional electrophysiological and voltage clamp techniques. 2 At a concentration of 2.5 micrograms/ml polymyxin B produced neuromuscular blockade in 10 to 15 min neuromuscular block was characterized by a depressed e.p.p. quantal content (28 plus or minus 7), which was similar to that determined from endplates exposed to 13 mM magnesium (23 plus or minus 3), and a low e.p.p. quantal size, which was simi...

Durant, N. N.; Lambert, J. J.

1981-01-01

239

Neuromuscular hamartoma: imaging features of a rare paediatric craniofacial tumour  

International Nuclear Information System (INIS)

Neuromuscular hamartoma (also referred to as neuromuscular choristoma or benign triton tumour) has not previously been described in the radiological literature. It is a rare benign lesion composed of mature elements of striated muscle and neural tissue. We report a case of neuromuscular hamartoma involving the skull base, nasopharynx, orbit and maxilla in a 2.5-year-old child who presented with facial swelling. The CT and MRI appearances of this unusual soft-tissue tumour are emphasized, together with a discussion of the pathological findings, differential diagnosis and review of the literature. (orig.)

2003-01-01

240

The differential effects of PNF versus passive stretch conditioning on neuromuscular performance.  

Science.gov (United States)

The effects of flexibility conditioning on neuromuscular and sensorimotor performance were assessed near to full knee extension (25°). Eighteen males who were randomly assigned into two groups underwent eight weeks (three-times per week) of flexibility conditioning (hip region/knee flexor musculature; dominant limb) involving either proprioceptive neuromuscular facilitation (PNF) (n=9) or passive stretching (PASS) (n=9). Both modes of flexibility conditioning are popular within contemporary exercise and clinical settings and have demonstrated efficacy in improving range of motion. The contralateral limb and a prior 'no exercise' condition were used as controls. The PNF and PASS modes of conditioning improved passive hip flexibility to a similar extent (mean 19.3% vs. baseline, intervention limb, ppassive to help preserve dynamic joint stability capabilities at this extended and vulnerable joint position. PMID:23688197

Minshull, Claire; Eston, Roger; Bailey, Andrea; Rees, David; Gleeson, Nigel

2014-01-01

 
 
 
 
241

Mechanical properties of compacts and particles that control tableting success.  

Science.gov (United States)

The use and limitations of linear-elasticity equations for describing mechanical properties of compacts is discussed; the limitations occur because compacts are porous, viscoelastic, nonhomogeneous, Mohr bodies. Awareness of these properties permits meaningful comparisons to be made. Ignoring limitations may result in unjustified conclusions. Special care during measuring mechanical properties of compacts is required. The mechanical criteria for a successful formulation are good flowability for powders and adequate strength without fracture for compacts. Interparticle attraction is spontaneous but particle contact numbers and size are limited by mechanical preclusion. Plastic deformation and fracture mechanics are controlling mechanisms with the magnitude of elastic constants having little effect on the successful processing. General compaction characteristics can be appraised by using combinations of properties, e.g., specific tableting indices. PMID:9294809

Hiestand, E N

1997-09-01

242

Gastrointestinal neuromuscular pathology in alpers disease.  

Science.gov (United States)

Alpers disease is a recessive mitochondrial disorder caused by mutations in POLG1 and characterized primarily by progressive neurological and hepatic degeneration. Intestinal dysmotility is a frequent symptom, but it is often overshadowed by other clinical manifestations. The onset and progression of Alpers disease vary; however, most patients die during childhood, often before a specific diagnosis has been established. The gastrointestinal neuromuscular pathology of 4 patients, obtained largely from postmortem specimens, showed distinctive eosinophilic cytoplasmic granules in a subset of enteric ganglia and patchy atrophy of small intestinal muscularis externa. The cytoplasmic inclusions corresponded to abnormal mitochondria, which have been reported previously in another mitochondrial disorder (mitochondrial neurogastrointestinal encephalomyopathy) but not in Alpers disease. Recognition of these distinctive light microscopic findings, in an appropriate clinical setting, should prompt the evaluation of an underlying primary mitochondriopathy. PMID:21451360

Kapur, Raj P; Fligner, Corinne; Maghsoodi, Bita; Jaffe, Ronald

2011-05-01

243

Neuromuscular Evaluation of Trunk-Training Exercises.  

Science.gov (United States)

OBJECTIVE: To evaluate the neuromuscular activation profiles of trunk muscles in commonly used gymnastic strength exercises with a polymyographic set-up and to describe the training effects of each exercise. DESIGN AND SETTING: Subjects performed 9 repetitions of each of 12 gymnastic exercises. Variations of 5 trunk flexions, 5 extensions, and 2 lateral-flexion movements were performed under standardized test conditions. SUBJECTS: Ten healthy subjects (men and women) who were familiar with the exercises participated in the study. MEASUREMENTS: We recorded surface electromyograms (EMGs) from the rectus abdominis, external oblique, rectus femoris, middle trapezius, erector spinae at T12 and L3, gluteus maximus, and semitendinosus and semimembranosus muscles. Recording of each repetition cycle was triggered by a flexible electronic goniometer attached to the trunk. The raw EMG signals were rectified, smoothed, amplitude normalized to maximal voluntary contraction (MVC), and averaged for the last 8 repetitions. RESULTS: Pure spine-flexion exercises, such as a curl-up, produced sufficient and isolated activation (greater than 50% MVC) of the abdominal muscles. When flexion of the spine was combined with hip flexion (sit-up), the peak activation was increased. Lateral-flexion tasks targeted primarily the external oblique muscle, which demonstrated high activity in side-lying flexion tasks. Back- and hip-extension exercises, such as bridging and diagonal hip and shoulder extension, produced only moderate mean activities (less than 35% MVC) in the trunk-extensor muscles. Trunk-extension exercises with combined hip extension increased the EMG activity to 50% MVC but only at the end of the extension. CONCLUSIONS: Individual responses to each exercise varied markedly, which complicated the classification of exercise effects. However, within the limitations of the study, we found that the chosen abdominal exercises provided an effective training stimulus for the trunk-flexor muscles, whereas in the back- and hip-extension exercises, the neuromuscular activation tended to be too low or unspecific to qualify as muscle-specific training. PMID:12937449

Konrad, Peter; Schmitz, Klaus; Denner, Achim

2001-06-01

244

Growth Control and Disease Mechanisms in Computational Embryogeny  

Science.gov (United States)

This paper presents novel approach to applying growth control and diseases mechanisms in computational embryogeny. Our method, which mimics fundamental processes from biology, enables individuals to reach maturity in a controlled process through a stochastic environment. Three different mechanisms were implemented; disease mechanisms, gene suppression, and thermodynamic balancing. This approach was integrated as part of a structural evolutionary model. The model evolved continuum 3-D structures which support an external load. By using these mechanisms we were able to evolve individuals that reached a fixed size limit through the growth process. The growth process was an integral part of the complete development process. The size of the individuals was determined purely by the evolutionary process where different individuals matured to different sizes. Individuals which evolved with these characteristics have been found to be very robust for supporting a wide range of external loads.

Shapiro, Andrew A.; Yogev, Or; Antonsson, Erik K.

2008-01-01

245

Optimal piezo-electro-mechanical coupling to control plate vibrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new way of coupling electrical and mechanical waves, using piezoelectric effect, is presented here. Since the energy exchange between two systems supporting wave propagation is maximum when their evolution is governed by similar equations, hence, an optimal electromechanical coupling is obtained by designing an electric network which is "analog" to the mechanical structure to be controlled. In this paper, we exploit this idea to enhance the coupling, between a Kirchhoff-Lo...

Alessandroni, S.; Isola, F.; Frezza, F.

2010-01-01

246

Master-slave synchronization control of mechanically coupled Robot Manipulators  

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Different synchronization schemes are considered for controlling a mechanically coupled multi-robot system on a robotized platform. The schemes are briefly presented and compared, before the feasibility of the popular master-slave synchronization scheme used on mechanically coupled robot manipulators is analyzed. Both analytic results for a simplified system of one dimension and results produced by simulation of a generic industrial robot manipulator are presented.

Aune, Rune Tevasvold

2007-01-01

247

Mechanisms of Controlled Release from Silk Fibroin Films  

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The controlled release of fluorescein-iso-thio-cyanate (FITC) labeled dextrans from methanol treated and untreated silk fibroin films was modeled to characterize the release kinetics and mechanisms. Silk films were prepared with FITC-dextrans of various molecular weights (4, 10, 20, 40 kDa). Methanol treatment was used to promote crystallinity. The release data were assessed with two different models, an empirical exponential equation commonly fit to release data and a mechanism based semi-em...

Hines, Daniel J.; Kaplan, David L.

2011-01-01

248

An examination of neuromuscular and metabolic fatigue thresholds.  

Science.gov (United States)

This study examined the relationships among the physical working capacity at the fatigue threshold (PWCFT), the power outputs associated with the gas exchange threshold (PGET) and the respiratory compensation point (PRCP), and critical power (CP) to identify possible physiological mechanisms underlying the onset of neuromuscular fatigue. Ten participants (mean ± SD age: 20 ± 1 years) performed a maximal incremental cycle ergometer test to determine the PWCFT, PGET, and PRCP. CP was determined from the 3 min all-out test. The PWCFT (197 ± 55 W), PRCP (212 ± 50 W), and CP (208 ± 63 W) were significantly greater than the PGET (168 ± 40 W), but there were no significant differences among the PWCFT, PRCP, and CP. All thresholds were significantly inter-4 (r = 0.794-0.958). The 17% greater estimates for the PWCFT than PGET were likely related to differences in the physiological mechanisms that underlie these fatigue thresholds, while the non-significant difference and high correlation between the PWCFT and the PRCP suggested that hyperkalemia may underlie both thresholds. Furthermore, it is possible that the 5% lower estimate of the PWCFT than CP could more accurately reflect the demarcation of the heavy from severe exercise intensity domains. PMID:24021781

Bergstrom, Haley C; Housh, Terry J; Cochrane, Kristen C; Jenkins, Nathaniel D M; Lewis, Robert W; Traylor, Daniel A; Zuniga, Jorge M; Schmidt, Richard J; Johnson, Glen O; Cramer, Joel T

2013-10-01

249

Study of Seed Dormancy Mechanisms; Causes and Control  

Directory of Open Access Journals (Sweden)

Full Text Available Dormancy mechanisms in cereals and oilseed crops were reviewed. Objective was to determine the causes of seed dormancy. The methods of control of seed dormancy were also reviewed and the following results were obtained. During seed dormancy, a mature embryo remains inactive but viable. An understanding of seed dormancy mechanisms can be helpful in optimizing the distribution of seed germination in time or space. Seed coats, cotyledons and growth hormones play an important role in maintaining seed dormancy. Seed dormancy can also be controlled by environment and genetic factors.

Syeda Nasreen

2002-01-01

250

Teaching Visually Impaired Adults with a Neuromuscular Disorder.  

Science.gov (United States)

The effects of four neuromuscular disorders (stroke, Parkinson's disease, Huntington's disease, and Lou Gehrig's disease) on concommitant visual impairments are considered. Rehabilitation approaches and equipment that help clients cope with the condition are described. (CL)

Williams, Susan

1983-01-01

251

Neuromuscular Blocking Properties of Lincomycin and Kanendomycin in Man.  

Science.gov (United States)

It has been well recognized that certain antibiotics such as neomycin and streptomycin have a neuromuscular blocking action, occasionally resulting in postoperative prolonged respiratory depression. An interaction between muscle relaxants and lincomycin a...

Y. Hashimoto N. Iwatsuki T. Shima K. Iwatsuki

1975-01-01

252

[Neuromuscular relaxation and CCMDP. The Zilgrei and Feldenkrais methods 2].  

Science.gov (United States)

The Authors show two neuromuscular release methods employed in the treatment of cranio-cervico-mandibular syndrome; these methods work at the place of origin of the pathology resolving the symptoms in different districts of the body. PMID:2701432

Santoro, F; Maiorana, C; Faccin, C

1989-10-31

253

Conservative Transmit Power Control Mechanism for 802.11 Mesh  

Science.gov (United States)

Power control techniques for IEEE 802.11 wireless networks have already gained considerable attention. Such techniques are particularly attractive because they can improve various aspects of wireless network operation such as interference mitigation, spatial reuse in dense wireless deployments, topology control, and link quality enhancement. In this paper we propose a novel delivery ratio based Conservative Transmit Power Control (ConTPC) mechanism. Our implementation is conservative when it comes to deciding if the transmit power should be reduced for a given link. This is because we do not want poor quality wireless links to further reduce their quality and be overwhelmed by other links transmitting at maximum power. We have experimentally evaluated the benefit of the proposed power control scheme when compared with fixed power level systems. We show that our ConTPC mechanism can increase the throughput, however the magnitude of this enhancement largely depends on the topology of the wireless network.

Kowalik, Karol; Bykowski, Marek; Keegan, Brian; Davis, Mark

254

[Controlled mechanical lung ventilation with guaranteed volume in newborns].  

Science.gov (United States)

Mechanical ventilation with guaranteed volumes combines advantages of time-cyclic ventilation with limitation of pressure and constant flow, with volume control ventilation. This symbiosis allows to choose the optimal, stable breathing volume of the newborn, while maintaining pressure control. The review presents the principles of work, the main advantages and limitations of ventilation systems with the guaranteed volumes, as well as results and analysis of studies. PMID:21510070

Kriakvina, O A; Grebennikov, V A; Tsypin, L E; Volodin, N N

2011-01-01

255

Control rod drive mechanism with shock absorber for nuclear reactor  

International Nuclear Information System (INIS)

The mechanism usable in a PWR has a shaft carrying the bar vertically displaceable in the reactor internals and a dash pot with a hydraulic cylinder and a piston. The cylinder has a large diameter perforated upper section to the cylinder, a small diameter lower section, a piston traversed by the control rod sized to fit into the upper section and forced downwards when the control descends. The shock absorbing chamber is defined between the piston and the upper section

1988-02-11

256

Soft Time-Suboptimal Controlling Structure for Mechanical Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents conception of a soft control structure based on the time-optimal approach. Its parameters are selected in accordance with the rules of the statistical decision theory and additionally it allows to eliminate rapid changes in control values. The object is a basic mechanical system, with uncertain (also non-stationary) mass treated as a stochastic process. The methodology proposed here is of a universal nature and may easily be applied with respect to other uncertainty element...

Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr; Krawiec, Karol

2004-01-01

257

Soft Time-Suboptimal Controlling Structure for Mechanical Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents conception of a soft control structure based on the time-optimal approach. Its parameters are selected in accordance with the rules of the statistical decision theory and additionally it allows to eliminate rapid changes in control values. The object is a basic mechanical system, with uncertain (also non-stationary) mass treated as a stochastic process. The methodology proposed here is of a universal nature and may easily be applied with respect to other uncertainty element...

Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr; Krawiec, Karol

2005-01-01

258

The Analysis on Financial Cooperative Controlling Mechanism of Enterprise Group  

Digital Repository Infrastructure Vision for European Research (DRIVER)

As the core of modern market economy, enterprise group is an advanced form of organization after productive forces reached to a certain stage. For the reason of complexity and specificity of organizational form of enterprise group, the issue of financial cooperative control has been widespread concerned by theorists. Although many researches have been done, but there are still lacking of systematic research results especially in the fields of mechanism of financial cooperative control. After ...

Ziqin Feng

2010-01-01

259

Patient Machine Interface for the Control of Mechanical Ventilation Devices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The potential of Brain Computer Interfaces (BCIs) to translate brain activity into commands to control external devices during mechanical ventilation (MV) remains largely unexplored. This is surprising since the amount of patients that might benefit from such assistance is considerably larger than the number of patients requiring BCI for motor control. Given the transient nature of MV (i.e., used mainly over night or during acute clinical conditions), precluding the use of invasive methods, a...

Rolando Grave de Peralta; Sara Gonzalez Andino; Stephen Perrig

2013-01-01

260

Fuzzy logic controller for weaning neonates from mechanical ventilation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Weaning from mechanical ventilation is the gradual detachment from any ventilatory support till normal spontaneous breathing can be fully resumed. To date, we have developed a fuzzy logic controller for weaning COPD adults using pressure support ventilation (PS). However, adults and newborns differ in the pathophysiology of lung disease. We therefore used our fuzzy logic-based weaning platform to develop modularized components for weaning newborns with lung disease. Our controller uses the he...

Hatzakis, G. E.; Davis, G. M.

2002-01-01

 
 
 
 
261

Electrical characterization of DNA in mechanically controlled break-junctions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Electrical characterization of DNA molecules using the mechanically controlled break-junction technique is presented. The mainadvantage of the technique is the control over the electrode distance during the measurement. This can be used to stretch the DNA and search for the in?uence of the conformation on the conduction process. The DNA is characterized in liquid and dry environments. From our data, we conclude that only a small number of molecules are contacted in each measurement.

Kang, Ning; Erbe, Artur; Scheer, Elke

2008-01-01

262

Immune control by endocannabinoids - new mechanisms of neuroprotection?  

Science.gov (United States)

The endocannabinoid system consists of cannabinoid receptors, their endogenous ligands and enzymes for synthesis and degradation of endocannabinoids and represents a local messenger system within and between the nervous and immune system. Apparently, the endocannabinoid system is involved in immune control and neuoprotection. In this review, we discuss possible mechanisms of immune control by endocannabinoids, which include the modulation of innate immunity, effects on cytokin networks, downregulation of adaptive immune response and apoptosis in immune cells. PMID:17196262

Ullrich, Oliver; Merker, Katrin; Timm, Johanna; Tauber, Svantje

2007-03-01

263

Formation of neuromuscular junctions in rat embryo cell cultures  

International Nuclear Information System (INIS)

The morphological evidence of the primary nerve muscle contacts are described. They consist of areas of cholinesterase activity (detected histochemically) localized on the myotube membranes and of multiple clusters of ACh receptors whose 125I-?-bungarotoxin binding sites are revealed by radioautography. After the stage of the primary nerve muscle contacts, some of which seem transient, characteristic neuromuscular junctions appear. These neuromuscular junctions which possess subneural infoldings are similar to the end-plates of the rat in vivo

1978-05-22

264

Neuromuscular blockade in cardiac surgery: An update for clinicians  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There have been great advancements in cardiac surgery over the last two decades; the widespread use of off-pump aortocoronary bypass surgery, minimally invasive cardiac surgery, and robotic surgery have also changed the face of cardiac anaesthesia. The concept of "Fast-track anaesthesia" demands the use of nondepolarising neuromuscular blocking drugs with short duration of action, combining the ability to provide (if necessary) sufficiently profound neuromuscular blockade during surge...

2008-01-01

265

How Myasthenia Gravis Alters the Safety Factor for Neuromuscular Transmission  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Myasthenia gravis (MG), the most common of autoimmune myasthenic syndromes, is characterized by antibodies directed against the skeletal muscle acetylcholine receptors (AChRs). Endplate Na+ channels ensure the efficiency of neuromuscular transmission by reducing the threshold depolarization needed to trigger an action potential. Postsynaptic AChRs and voltage-gated Na+ channels are both lost from the neuromuscular junction in MG. This study examined the impact of postsynaptic voltage-gated Na...

2008-01-01

266

NEUROMUSCULAR ELECTRICAL STIMULATION INDUCED FORELIMB MOVEMENT IN A RODENT MODEL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Upper extremity neuromuscular electrical stimulation (FNS) has long been utilized as a neuroprosthesis to restore hand-grasp function in individuals with neurological disorders and injuries. More recently, electrical stimulation is being used as a rehabilitative therapy to tap into central nervous system plasticity. Here, we present initial development of a rodent model for neuromuscular stimulation induced forelimb movement that can be used as a platform to investigate stimulation-induced pl...

Kanchiku, Tsukasa; Lynskey, James V.; Protas, Danielle; Abbas, James J.; Jung, Ranu

2008-01-01

267

Treatment of postoperative infection after posterior spinal fusion and instrumentation in a patient with neuromuscular scoliosis.  

Science.gov (United States)

According to the literature, patients with neuromuscular scoliosis have a higher rate of infection after spinal fusion. No randomized controlled trials have been completed to assess the optimal treatment and related outcomes for patients with infections after posterior spinal fusion. In this article, we examine the data and report a case in which a vacuum-assisted closure (VAC) device was used as definitive treatment for a deep wound infection after posterior spinal fusion and instrumentation in a patient with neuromuscular scoliosis. Our patient, a 17-year-old adolescent girl with progressive neuromuscular scoliosis, underwent posterior spinal fusion with instrumentation and bone graft from T2 to sacrum without complication. One month after surgery, she presented with a draining wound. She underwent repeat surgical irrigation and debridement with subsequent use of a wound VAC. The wound VAC was used for more than 2 months, until skin closure was complete. The deep polymicrobial wound infection was treated successfully and definitively with a wound VAC. This case report suggests that good long-term outcomes can be achieved with use of a wound VAC for definitive closure, with possible avoidance of other secondary surgeries requiring skin grafts or flaps for wound closure. PMID:24551867

Ghattas, Paul J; Mehlman, Charles T; Eichten, David

2014-02-01

268

An accurate error control mechanism for simplification before generation algorithms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of simplification before generation techniques to enable the approximate symbolic analysis of large analog circuits is discussed. This paper introduces an error control mechanism to drive the circuit reduction, which overcomes the accuracy problems of previous approaches. The features and efficiency of the new methodology are demonstrated through several practical examples.

Guerra, Oscar; Rodriguez-garcia, J. D.; Roca, E.; Ferna?ndez, Francisco V.; Rodri?guez Va?zquez, Angel

1999-01-01

269

Fluid Mechanics of Wing Adaptation for Separation Control  

Science.gov (United States)

The unsteady fluid mechanics associated with use of a dynamically deforming leading edge airfoil for achieving compressible flow separation control has been experimentally studied. Changing the leading edge curvature at rapid rates dramatically alters the flow vorticity dynamics which is responsible for the many effects observed in the flow.

Chandrasekhara, M. S.; Wilder, M. C.; Carr, L. W.; Davis, Sanford S. (Technical Monitor)

1997-01-01

270

State of process control development for mechanical drivage  

Energy Technology Data Exchange (ETDEWEB)

The report is a brief review of the development state of contour and directional control and cutting performance optimization devices as well as machine monitors for mechanical drivage in underground mining. Descriptions of equipments and devices manufactured by Atlas-Copco-Eckhoff Roadheading Technic GmbH, Paurat GmbH, Westfalia Luenen and Voest-Alpine Finalindustrie are given. (MOS).

Boldt, H. (Bergbau AG Niederrhein, Duisburg (Germany, F.R.))

1989-01-01

271

Quasivelocities and Optimal Control for underactuated Mechanical Systems  

International Nuclear Information System (INIS)

This paper is concerned with the application of the theory of quasivelocities for optimal control for underactuated mechanical systems. Using this theory, we convert the original problem in a variational second-order lagrangian system subjected to constraints. The equations of motion are geometrically derived using an adaptation of the classical Skinner and Rusk formalism.

2010-07-28

272

Mechanisms controlling the onset of simulated convectively coupled Kelvin waves  

Directory of Open Access Journals (Sweden)

Full Text Available Convectively coupled Kelvin waves (CCKW are analysed using a cloud-resolving model to gain a better understanding of the mechanisms that initiate and drive these waves. We compare the modelled precipitation and vertical structure of a convectively coupled Kelvin wave to the mechanisms that control precipitation over warm tropical oceans: convective inhibition (CIN, saturation fraction, atmospheric stability and surface moist entropy fluxes. Our results show that the primary onset mechanism for precipitation associated with CCKW is CIN associated with a decrease in the threshold moist entropy. Saturation fraction and atmospheric instability exhibit a time lag in comparison with the rainfall evolution and are, therefore, not primary controls in the onset of these waves. The modelled CCKW evolve by starting with congestus convection, develop into deep convection and decay with the stratiform convection. The results from the presented model agree with observations and linearised models.

Željka Fuchs

2014-01-01

273

Robust control of multi-jointed arm with a decentralized autonomous control mechanism  

Science.gov (United States)

A decentralized autonomous control mechanism applied to the control of three dimensional manipulators and its robustness to partial damage was assessed by computer simulation. Decentralized control structures are believed to be quite robust to time delay between the operator and the target system. A 10-jointed manipulator based on our control mechanism was able to continue its positioning task in three-dimensional space without revision of the control program, even after some of its joints were damaged. These results suggest that this control mechanism can be effectively applied to space telerobots, which are associated with serious time delay between the operator and the target system, and which cannot be easily repaired after being partially damaged.

Kimura, Shinichi; Miyazaki, Ken; Suzuki, Yoshiaki

1994-01-01

274

Control rod drive mechanisms in BWR type reactors  

International Nuclear Information System (INIS)

Purpose: To reduce the intrusion of chloride ions and water of highly dissolved oxygen content to control rod drive mechanisms and the reactor core as low as possible. Constitution: Driving water for control rod drive mechanisms is usually supplied from a condensate desalter. However, if the electroconductivity at the exit of the condensate desalter is increased due to sea water leakage in the condensor, the control rod driving water is automatically switched from that of condensate storage tank water and dissolved oxygen density in the condensate storage tank water is supplied as control rod driving water in which the dissolved oxygen density is reduced to about several tens ppb by the deareation. In this way, intrusion of chloride ions by way of the control rod driving mechanisms into the reactor core upon sea water leakage in the condensor can be decreased, as well as the stress corrosion crackings in the core components can be reduced since deareated water is used as the driving water. (Kamimura, M.)

1985-05-24

275

Seismic analysis of control and safety rod drive mechanism  

International Nuclear Information System (INIS)

Control rod and its driving mechanism for a Fast Breeder Reactor is to facilitate safe shutdown of the reactor in case of emergency. A theoretical study on the seismic qualification of control and safety rod driving mechanism is carried out. Earthquake excitations under Operational Basis (ORE) and Safe Shutdown condition (SSE) are considered. The time required for the control rod to reach the bottom position in order to shut down the reaction under excited condition is traced out. The maximum displaced positions and extreme stresses in various parts of the system under excitations are evaluated. The system modeled using beam elements. The connections between different parts are modeled through rigid elements. The interaction between various parts are modeled using GAP elements. (author)

2003-02-01

276

Sliding mode control on electro-mechanical systems  

Directory of Open Access Journals (Sweden)

Full Text Available The first sliding mode control application may be found in the papers back in the 1930s in Russia. With its versatile yet simple design procedure the methodology is proven to be one of the most powerful solutions for many practical control designs. For the sake of demonstration this paper is oriented towards application aspects of sliding mode control methodology. First the design approach based on the regularization is generalized for mechanical systems. It is shown that stability of zero dynamics should be taken into account when the regular form consists of blocks of second-order equations. Majority of applications in the paper are related to control and estimation methods of automotive industry. New theoretical methods are developed in the context of these studies: sliding made nonlinear observers, observers with binary measurements, parameter estimation in systems with sliding mode control.

Utkin Vadim I.

2002-01-01

277

Neuromuscular Fatigue During 200 M Breaststroke  

Science.gov (United States)

The aims of this study were: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1st to the 3rd lap. SR increased on the 4th lap (35.91 ± 2.99 stroke·min-1). Peak blood lactate was 13.02 ± 1.72 mmol·l-1 three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1st lap and for biceps brachii, deltoid anterior and triceps brachii in the 4th lap. The mean frequency of the power spectral density (MNF) decreased at the 4th lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2nd lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state. Key Points Fatigue in the upper limbs occurs in different way as it described by 100m swimming events. Neuromuscular fatigue was estimated by analyzing the physiological changes (high blood lactate concentrations), biomechanical changes in the swimming stroke characteristics (decreased in swimming velocity), and by the changes in the EMG amplitude and frequency parameters at the end of the swimming bout. The amplitude signal of EMG provided by the ARV demonstrated an increase at the end with the respect to the beginning for all muscles under study, excepted for the muscle deltoid anterior. The mean frequency (MNF) in our study decrease at the end of the swimming in the 4th lap relative to the 1st lap for all muscles under observation, along the 200m breaststroke.

Conceicao, Ana; Silva, Antonio J.; Barbosa, Tiago; Karsai, Istvan; Louro, Hugo

2014-01-01

278

Differences in neuromuscular fatigue after aerobic and anaerobic running loads  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the research was to establish some characteristics and differences in neuromuscular fatigue after different running loads. Seven well-trained runners performed two running tasks: an interval run of 5 x 300 m at sub-maximum speed with a one-min rest (100 m jogging between individual runs, and a continuous 6-km run at the anaerobic threshold speed (criterion VOBLA. To measure the contractile characteristics of the femuris muscle quadriceps before and after a running load the following electrical stimulation (ES tests were used: single twitch, low - and high-frequency stimulation, the maximum voluntary knee extension test and the muscle activation level test. The anaerobic interval runs caused a greater decline in maximum torque twitch (p<0.05 and a greater decline in maximum muscular relaxation rate (p<0.05 compared to the longer continuous run. The anaerobic interval load reduced muscle contraction at both low and high frequencies of ES, while the aerobic continuous run led to a lowering of muscle contraction force but only at low frequencies of stimulation. After both charges the decrease in ES-evoked muscle contraction was bigger than the decrease in torque at MVC. Both running loads caused peripheral fatigue. The lowering of muscular contractile ability after both loads was mainly the consequence of disturbance in the Ca transport system mechanism, while after the intensive interval runs this was also a result of disturbance in the spreading action potential across the sarcomere.

B Škof

2008-12-01

279

Versatile cable handling mechanisms for remote operator control  

International Nuclear Information System (INIS)

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other, between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (UK)

1996-01-01

280

Versatile cable handling mechanisms for remote operator control  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author).

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D. [Portech Ltd., Portsmouth (United Kingdom)

1996-12-31

 
 
 
 
281

Versatile cable handling mechanisms for remote operator control  

International Nuclear Information System (INIS)

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author)

1996-01-01

282

Fisiopatología de las alteraciones neuromusculares en el paciente crítico / Pathophysiology of neuromuscular impairments in the critically ill patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivo: Analizar las causas y manifestaciones de la debilidad muscular que desarrollan los pacientes críticos durante su estancia en la UCI y revisar la bibliografía. Desarrollo: A principios de los años 80 se describió en pacientes críticos sépticos una polineuropatía axonal mixta que clínicament [...] e se caracterizaba por una debilidad muscular de intensidad variable que en su vertiente más grave producía tetraplejia y/o dependencia del ventilador. Casi paralelamente se describió la miopatía aguda de los cuidados intensivos en pacientes asmáticos que eran ingresados en la UCI por exacerbación de su enfermedad. Con posterioridad se observó que esta miopatía se presentaba también en pacientes trasplantados, sépticos o quemados. Hay autores que consideran a la miopatía aguda de los cuidados intensivos como la primera causa de debilidad muscular en la UCI. Conclusiones: En este artículo se describen la clínica, etiopatogenia, diagnóstico y tratamiento de la polineuropatía del paciente crítico y de la miopatía aguda de los cuidados intensivos. Los dos cuadros clínicos son diferenciables en muchas ocasiones, siendo de gran ayuda los estudios neurofisiológicos y eventualmente la biopsia muscular. Aunque algunos autores prefieren englobar estas entidades bajo el nombre de polineuromiopatía, proponemos la denominación general de Síndrome Neuromuscular Agudo en el paciente crítico término más descriptivo, que no presupone un mecanismo ni una etiología única. Abstract in english Objective: to analyze the causes and manifestations of muscle weakness that critically ill patients develop during their staying at the ICU, and literature review. Development: in the early 1980s, a mixed axonal polyneuropathy was described in septic critically ill patients, which clinically manifes [...] ted by muscle weakness of variable severity, leading to quadriplegia and/or ventilator dependency in its most severe presentation. Almost at the same time, an acute intensive care myopathy was described in asthmatic patients admitted to the ICU for asthma exacerbation. Later on, this myopathy was also observed in transplanted, septic, or burnt patients. Several authors consider acute intensive care myopathy as the main cause of muscle weakness in the ICU. Conclusions: in this article, we describe the clinical presentation, etiopathogenesis, diagnosis, and treatment of polyneuropathy of the critically ill patient and of acute intensive care myopathy. Both clinical pictures may be differentiated, with neurophysiological studies and eventually muscle biopsy being of great help. Although some authors rather include these conditions under the name of polyneuromyopathy, we propose the general denomination of Acute Neuromuscular Syndrome of the Critically Ill Patient, a more descriptive term no presupposing a single mechanism or etiology.

García de Lorenzo, A.; Vilas, E.; Rodríguez Montes, J. A..

283

Fisiopatología de las alteraciones neuromusculares en el paciente crítico Pathophysiology of neuromuscular impairments in the critically ill patients  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo: Analizar las causas y manifestaciones de la debilidad muscular que desarrollan los pacientes críticos durante su estancia en la UCI y revisar la bibliografía. Desarrollo: A principios de los años 80 se describió en pacientes críticos sépticos una polineuropatía axonal mixta que clínicamente se caracterizaba por una debilidad muscular de intensidad variable que en su vertiente más grave producía tetraplejia y/o dependencia del ventilador. Casi paralelamente se describió la miopatía aguda de los cuidados intensivos en pacientes asmáticos que eran ingresados en la UCI por exacerbación de su enfermedad. Con posterioridad se observó que esta miopatía se presentaba también en pacientes trasplantados, sépticos o quemados. Hay autores que consideran a la miopatía aguda de los cuidados intensivos como la primera causa de debilidad muscular en la UCI. Conclusiones: En este artículo se describen la clínica, etiopatogenia, diagnóstico y tratamiento de la polineuropatía del paciente crítico y de la miopatía aguda de los cuidados intensivos. Los dos cuadros clínicos son diferenciables en muchas ocasiones, siendo de gran ayuda los estudios neurofisiológicos y eventualmente la biopsia muscular. Aunque algunos autores prefieren englobar estas entidades bajo el nombre de polineuromiopatía, proponemos la denominación general de Síndrome Neuromuscular Agudo en el paciente crítico término más descriptivo, que no presupone un mecanismo ni una etiología única.Objective: to analyze the causes and manifestations of muscle weakness that critically ill patients develop during their staying at the ICU, and literature review. Development: in the early 1980s, a mixed axonal polyneuropathy was described in septic critically ill patients, which clinically manifested by muscle weakness of variable severity, leading to quadriplegia and/or ventilator dependency in its most severe presentation. Almost at the same time, an acute intensive care myopathy was described in asthmatic patients admitted to the ICU for asthma exacerbation. Later on, this myopathy was also observed in transplanted, septic, or burnt patients. Several authors consider acute intensive care myopathy as the main cause of muscle weakness in the ICU. Conclusions: in this article, we describe the clinical presentation, etiopathogenesis, diagnosis, and treatment of polyneuropathy of the critically ill patient and of acute intensive care myopathy. Both clinical pictures may be differentiated, with neurophysiological studies and eventually muscle biopsy being of great help. Although some authors rather include these conditions under the name of polyneuromyopathy, we propose the general denomination of Acute Neuromuscular Syndrome of the Critically Ill Patient, a more descriptive term no presupposing a single mechanism or etiology.

A. García de Lorenzo

2006-05-01

284

Ecological production of dryland hairy vetch by mechanical control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Winter hairy vetch, Vicia villosa Roth, gives high grain and hay yields. Mechanical control of weeds is an ecological alternative to the use of herbicides. Among the various mechanical methods, interrow weeding is cheap and practical. Nonetheless, wider row spacing than common practice is needed to ease the operation. We optimized row spacing and seed rates for high grain yield and to ease interrow cultivation. We used two row spacings of 45 and 60 cm as main plots and five seeding rates of 1...

Avci, Muzaffer; Akar, Taner

2006-01-01

285

Using reversible crosslink dynamics to control polymer network mechanics  

Science.gov (United States)

Growing evidence supports a role for metal-coordination in tuning the visco-elastic properties of soft biological polymeric materials. Using a bio-inspired metal-binding polymer we demonstrate how dynamics of metal-coordinate crosslinks can be used to tune network visco-elasticity. Metal ion identity and pH thereby provide access to control over mechanical properties of coordinate polymer networks. We discuss how the strong correlation between coordinate bond dynamics and polymer network mechanics is established and can ultimately be exploited in material applications.

Holten-Andersen, Niels; Fullenkamp, Dominic; Harrington, Matt; He, Lihong; Messersmith, Phillip; Lee, Ka Yee

2012-02-01

286

Coenzyme Q10 deficiencies in neuromuscular diseases.  

Science.gov (United States)

Coenzyme Q (CoQ) is an essential component of the respiratory chain but also participates in other mitochondrial functions such as regulation of the transition pore and uncoupling proteins. Furthermore, this compound is a specific substrate for enzymes of the fatty acids beta-oxidation pathway and pyrimidine nucleotide biosynthesis. Furthermore, CoQ is an antioxidant that acts in all cellular membranes and lipoproteins. A complex of at least ten nuclear (COQ) genes encoded proteins synthesizes CoQ but its regulation is unknown. Since 1989, a growing number of patients with multisystemic mitochondrial disorders and neuromuscular disorders showing deficiencies of CoQ have been identified. CoQ deficiency caused by mutation(s) in any of the COQ genes is designated primary deficiency. Other patients have displayed other genetic defects independent on the CoQ biosynthesis pathway, and are considered to have secondary deficiencies. This review updates the clinical and molecular aspects of both types of CoQ deficiencies and proposes new approaches to understanding their molecular bases. PMID:20225022

Artuch, Rafael; Salviati, Leonardo; Jackson, Sandra; Hirano, Michio; Navas, Plácido

2009-01-01

287

Stem cell route to neuromuscular therapies.  

Science.gov (United States)

As applied to skeletal muscle, stem cell therapy is a reincarnation of myoblast transfer therapy that has resulted from recent advances in the cell biology of skeletal muscle. Both strategies envisage the reconstruction of damaged muscle from its precursors, but stem cell therapy employs precursors that are earlier in the developmental hierarchy. It is founded on demonstrations of apparently multipotential cells in a wide variety of tissues that can assume, among others, a myogenic phenotype. The main demonstrated advantage of such cells is that they are capable of colonizing many tissues, including skeletal and cardiac muscle via the blood vascular system, thereby providing the potential for a body-wide distribution of myogenic progenitors. From a practical viewpoint, the chief disadvantage is that such colonization has been many orders of magnitude too inefficient to be useful. Proposals for overcoming this drawback are the subject of much speculation but, so far, relatively little experimentation. This review attempts to give some perspective to the status of the stem cell as a therapeutic instrument for neuromuscular disease and to identify issues that need to be addressed for application of this technology. PMID:12548520

Partridge, Terence A

2003-02-01

288

Efeito do priming na redução da latência do pipecurônio, novo bloqueador neuromuscular não-despolarizante Efecto del priming en la reducción de la latencia del pipecuronio, nuevo bloqueador neuromuscular no despolarizante Effect of priming in shortening onset of pipecuronium, a new nondepolarizing neuromuscular blocker  

Directory of Open Access Journals (Sweden)

Full Text Available JUSTIFICATIVA E OBJETIVOS: Uma das mais importantes propriedades dos bloqueadores neuromusculares é o rápido início de ação, possibilitando intubação traqueal precoce. A administração de pequena dose de bloqueador não-despolarizante antes da dose plena é sabidamente redutora da latência da maioria dos bloqueadores neuromusculares utilizados. O brometo de pipecurônio é um agente aminoesteróide de longa duração com grande estabilidade cardiovascular, porém, com início de ação tardio. O objetivo desse estudo foi avaliar o efeito do priming do pipecurônio em pacientes adultos submetidos a cirurgias eletivas sob anestesia geral. MÉTODO: Foram estudados 33 pacientes adultos de ambos os sexos, com idade entre 20 e 65 anos, estado físico ASA I ou II, submetidos a cirurgias eletivas sob anestesia geral. Foram excluídos do estudo pacientes com insuficiência renal ou hepática, neuromiopatia, uso concomitante de drogas que influenciem a sua farmacocinética ou pacientes com histórico familiar de hipertermia maligna. Foram divididos em dois grupos: Grupo 1 onde foi utilizado o priming com 0,01 mg.kg-1 e três minutos depois completada a dose de 0,08 mg.kg-1 e o Grupo 2, sem dose priming (Grupo Controle. O relaxamento neuromuscular foi controlado pela aceleromiografia (Aparelho TOF-Guard e no momento em que T1 JUSTIFICATIVA Y OBJETIVOS: Una de las más importantes propiedades de los bloqueadores neuromusculares es el rápido inicio de acción, posibilitando intubación orotraqueal precoz. La administración de pequeña dosis del bloqueador no despolarizante antes de la dosis completa es consabidamente reductora de la latencia de la mayoría de los bloqueadores neuromusculares utilizados. El bromuro de pipecuronio es un agente aminoesteroide de larga duración con grande estabilidad cardiovascular, sin embargo, con inicio de acción tardía. El objetivo de ese estudio es evaluar el efecto del priming del pipecuronio en pacientes adultos sometidos a cirugías electivas bajo anestesia general. MÉTODO: Fueron estudiados 32 pacientes adultos de ambos sexos, con edad entre 20 y 65 años, estado físico ASA I ó II, a ser sometidos a cirugías electivas bajo anestesia general. Fueron excluidos del estudio pacientes con insuficiencia renal o hepática, neuromiopatia, uso concomitante de drogas que influencien la farmacocinética de la droga o pacientes con histórico familiar de hipertermia maligna. Fueron divididos en dos grupos: Grupo 1 donde fue utilizada el priming con 0,01 mg.kg-1 3 minutos después de completada la dosis de 0,08 mg.kg-1 y el Grupo 2, sin dosis priming (Grupo Control. El relajamiento neuromuscular fue controlado por la aceleromiografía (Aparato TOF-Guard y en el momento en que T1 BACKGROUND AND OBJECTIVES: One of the most important neuromuscular blockers property is short onset, allowing early tracheal intubation. Low nondepolarizing blocker dose before the full dose is known to decrease the onset of most neuromuscular blockers. Pipecuronium bromide is a long-lasting aminosteroid with major cardiovascular stability, however, with late onset. This study aimed at evaluating pipecuronium priming effect in adult patients submitted to elective surgeries under general anesthesia. METHODS: Participated in this study 33 adult patients of both genders, aged 20 to 65 years, physical status ASA I or II, to be submitted to elective surgeries under general anesthesia. Exclusion criteria were patients with kidney or liver failure, neuromuscular diseases, in concurrent use of drugs influencing pipecuronium pharmacokinetics, and patients with family history of malignant hyperthermia. Patients were divided in 2 groups: Group 1 = priming with 0.01 mg.kg-1 and 3 minutes later the remaining 0.07 mg.kg-1 (total 0.08 mg.kg-1; Group 2 = no priming dose (group control. Neuromuscular relaxation was controlled by acceleromyography (TOF-Guard device and laryngoscopy was accomplished when T1 < 10%. T test for independent samples was used for statistical analysis and Shapiro Wilks was used to test no

José Carlos Canga

2005-08-01

289

New mechanism for the control of sodium transport in wheat  

International Nuclear Information System (INIS)

Full text: Durum and other tetraploid wheats are typically very salt-sensitive compared to hexaploid bread wheats. This is primarily due to high rates of Na+ accumulation in the leaves in tetraploid wheat. Recently, we have discovered a durum landrace with low Na+ accumulation and enhanced K+/Na+ discrimination, much lower than current durum cultivars and similar to bread wheat. We have identified 3 different mechanisms for the control of Na+ transport to the leaves in this landrace, 1) control of Na+ uptake at the epidermis of the root, 2) control of Na+ loading into the xylem and 3) partitioning of Na+ into the leaf sheath. The low Na+ durum landrace had 3-4 fold lower Na+ uptake rates than durum cultivars. Using X ray microanalysis on snap-frozen root sections, we found Na+ to be high in the epidermis, a decreasing gradient through the cortex, low in the endodermis and again high in the stele (pencycle and xylem parenchyma), indicative of control points at the epidermis and in the stele. Partitioning of Na+ between shoot and root was at least 5 times lower in the durum landrace, suggestive of greater control of Na+ transport at the site of xylem loading. A third and novel control mechanism was found in the leaf sheath. Short and long term salinity treatments showed that Na+ was partitioned preferentially into the sheaths of the low Na+ durum landrace, keeping leaf blade Na+ levels very low and similar to that of bread wheat Na+ partitioned in the leaf sheath was stored primarily in the parenchyma cells and Cl- in the epidermal cells. Collectively, these data show that we have identified germplasm that has the potential to increase the salt tolerance of durum wheat. Additionally, as bread wheat does not contain the mechanism for partitioning Na+ into the sheath, this trait may be useful for further increasing the salt tolerance of this species

2002-10-03

290

Fine Voltage Control Using Oltc by Static Tap Change Mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a novel model of fully electronic on load semiconductor tap changer for power transformer has been proposed. With high power semiconductor devices, problems associated with conventional mechanical on load tap changers which includes excessive conduction losses and arcing in the diverter switch have been properly rectified. In this work Simulink model was designed with GTOs as switching devices embedded in taps. Step change of voltage is achieved changing taps by switching GTOs and fine voltage with error less than ±0.1% is obtained by sequential firing control between GTOs in the system, which is not possible in conventional automatic OLTC control system.

S.V.M. Bhuvanaika rao , B.Subramanyeswar

2012-12-01

291

Model Predictive Vibration Control Efficient Constrained MPC Vibration Control for Lightly Damped Mechanical Structures  

CERN Multimedia

Real-time model predictive controller (MPC) implementation in active vibration control (AVC) is often rendered difficult by fast sampling speeds and extensive actuator-deformation asymmetry. If the control of lightly damped mechanical structures is assumed, the region of attraction containing the set of allowable initial conditions requires a large prediction horizon, making the already computationally demanding on-line process even more complex. Model Predictive Vibration Control provides insight into the predictive control of lightly damped vibrating structures by exploring computationally efficient algorithms which are capable of low frequency vibration control with guaranteed stability and constraint feasibility. In addition to a theoretical primer on active vibration damping and model predictive control, Model Predictive Vibration Control provides a guide through the necessary steps in understanding the founding ideas of predictive control applied in AVC such as: ·         the implementation of ...

Takács, Gergely

2012-01-01

292

Mechanical Spin Control of Nitrogen-Vacancy Centers in Diamond  

Science.gov (United States)

We demonstrate direct coupling between phonons and diamond nitrogen-vacancy (NV) center spins by driving spin transitions with mechanically generated harmonic strain at room temperature. The amplitude of the mechanically driven spin signal varies with the spatial periodicity of the stress standing wave within the diamond substrate, verifying that we drive NV center spins mechanically. These spin-phonon interactions could offer a route to quantum spin control of magnetically forbidden transitions, which would enhance NV-based quantum metrology, grant access to direct transitions between all of the spin-1 quantum states of the NV center, and provide a platform to study spin-phonon interactions at the level of a few interacting spins.

MacQuarrie, E. R.; Gosavi, T. A.; Jungwirth, N. R.; Bhave, S. A.; Fuchs, G. D.

2013-11-01

293

Molecular mechanisms controlling CFTR gene expression in the airway  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The low levels of CFTR gene expression and paucity of CFTR protein in human airway epithelial cells are not easily reconciled with the pivotal role of the lung in cystic fibrosis pathology. Previous data suggested that the regulatory mechanisms controlling CFTR gene expression might be different in airway epithelium in comparison to intestinal epithelium where CFTR mRNA and protein is much more abundant. Here we examine chromatin structure and modification across the CFTR locus in primary hum...

Zhang, Zhaolin; Ott, Christopher J.; Lewandowska, Marzena A.; Leir, Shih-hsing; Harris, Ann

2012-01-01

294

Workload Control Release Mechanisms: From Practice Back to Theory Building  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Much Workload Control research has focussed on the order release stage but failed to address practical considerations that impact practical application. Order release mechanisms have been developed through simulations that neglect job size variation effects while empirical evidence suggests groups of small/large jobs are often found in practice. When job sizes vary, it is difficult to release all jobs effectively – small jobs favour a short period between releases and a ...

2010-01-01

295

Control of directional change after mechanical stimulation in Drosophila  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Proper adjustment of moving direction after external mechanical stimulation is essential for animals to avoid danger (e.g. predators, and thus is vital for survival. This process involves sensory inputs, central processing and motor outputs. Recent studies have made considerable progress in identifying mechanosensitive neurons and mechanosensation receptor proteins. Our understandings of molecular and cellular mechanisms that link mechanosensation with the changes in moving direction, however, remain limited. Results In this study, we investigate the control of movement adjustment in Drosophila. In response to gentle touch at the anterior segments, Drosophila larvae reorient and select a new direction for forward movement. The extent of change in moving direction is correlated with the intensity of tactile stimuli. Sensation of gentle touch requires chordotonal organs and class IV da neurons. Genetic analysis indicates an important role for the evolutionarily conserved immunoglobulin (Ig superfamily protein Turtle (Tutl to regulate touch-initiated directional change. Tutl is required specifically in post-mitotic neurons at larval stage after the completion of embryonic development. Circuit breaking analysis identified a small subset of Tutl-positive neurons that are involved in the adjustment of moving direction. Conclusion We identify Tutl and a small subset of CNS neurons in modulating directional change in response to gentle touch. This study presents an excellent starting point for further dissection of molecular and cellular mechanisms controlling directional adjustment after mechanical stimulation.

Zhou Yating

2012-10-01

296

Mechanical design and optimal control of humanoid robot (TPinokio  

Directory of Open Access Journals (Sweden)

Full Text Available The mechanical structure and the control of the locomotion of bipedal humanoid is an important and challenging domain of research in bipedal robots. Accurate models of the kinematics and dynamics of the robot are essential to achieve bipedal locomotion. Toe-foot walking produces a more natural and faster walking speed and it is even possible to perform stretch knee walking. This study presents the mechanical design of a toe-feet bipedal, TPinokio and the implementation of some optimal walking gait generation methods. The optimality in the gait trajectory is achieved by applying augmented model predictive control method and the pole-zero cancellation method, taken into consideration of a trade-off between walking speed and stability. The mechanism of the TPinokio robot is designed in modular form, so that its kinematics can be modelled accurately into a multiple point-mass system, its dynamics is modelled using the single and double mass inverted pendulum model and zero-moment-point concept. The effectiveness of the design and control technique is validated by simulation testing with the robot walking on flat surface and climbing stairs.

Teck Chew Wee

2014-04-01

297

Conceptual Design of Bottom-mounted Control Rod Drive Mechanism  

Energy Technology Data Exchange (ETDEWEB)

The arrangement of the BMCRDMs and irradiation holes in the core is therefore easier than that of the top-mounted CRDM. Hence, many foreign research reactors, such as JRR-3M, JMTR, OPAL, and CARR, have adopted the BMCRDM concept. The purpose of this paper is to introduce the basic design concept on the BMCRDM. The major differences of the CRDMs between HANARO and KJRR are compared, and the design features and individual system of the BMCRDM for the KJRR are described. The Control Rod Drive Mechanism (CRDM) is a device to regulate the reactor power by changing the position of a Control Absorber Rod (CAR) and to shut down the reactor by fully inserting the CAR into the core within a specified time. The Bottom-Mounted CRDM (BMCRDM) for the KiJang Research Reactor (KJRR) is a quite different design concept compared to the top-mounted CRDM such as HANARO and JRTR. The main drive mechanism of the BMCRDM is located in a Reactivity Control Mechanism (RCM) room under the reactor pool bottom, which makes the interference with equipment in the reactor pool reduced.

Lee, Jin Haeng; Kim, Sanghaun; Yoo, Yeonsik; Cho, Yeonggarp; Kim, Dongmin; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

298

On the optimal control of mechanical systems - hybrid control strategies and hybrid dynamics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Optimal control problems for mechanical systems manifoldly arise in the fields of engineering and natural sciences, for instance, in robotics, biomechanics, automotive systems, or in space mission design. Here, the aim is to influence the systems dynamical behavior via its control inputs such that a given problem is optimally solved. For complex technical systems, an adequate modeling leads to hybrid dynamical systems. Hybrid control strategies provide a range of new possibilities for the des...

2014-01-01

299

Using mouse cranial muscles to investigate neuromuscular pathology in vivo.  

Science.gov (United States)

Neuromuscular pathology is a classic hallmark of many diseases such as muscular dystrophy, myasthenia gravis, amyotrophic lateral sclerosis and spinal muscular atrophy. It is also a feature of many congenital and acquired myopathies and neuropathies such as diabetic neuropathy and toxin-exposure. The availability of experimentally accessible nerve-muscle preparations from rodent models in which pathological events can be studied in nerve and muscle, as well as at the neuromuscular junction, is therefore of fundamental importance for investigating neuromuscular disease. The group of small cranial muscles, which move the ear in the mouse provide ideal experimental preparations for the study of neuromuscular disease in vivo, but information regarding their anatomical and functional characteristics is currently lacking. Here, we provide a detailed description of the levator auris longus, auricularis superior, abductor auris longus and interscutularis muscles. In addition, we briefly review their differential fibre type and developmental characteristics, which can be exploited to aid our understanding of neuromuscular vulnerability and to provide preferable alternatives to more traditional muscle preparations such as gastrocnemius, soleus and diaphragm. PMID:20637618

Murray, L M; Gillingwater, T H; Parson, S H

2010-11-01

300

Control and locking mechanism for nuclear reactor control rod having a liquid coolant  

International Nuclear Information System (INIS)

The invention proposes a simple control rod drive mechanism for a reactor comprising a large number of control rods, among which some have to be moved simultaneously to keep a symmetric neutron flux distribution in the core. The mechanism has a cylinder surrounding the rod; this cylinder acts as a hydraulic cylinder in which the rod slides delimiting a compression chamber. Il includes mechanical fastening means for the rod in its raised position. It comprises an electromagnetically controlled pump in the cylinder which reduces the pressure of the reactor coolant in it to raise the rod, and an electromagnetically controlled valve in the cylinder opening it to the reactor vessel and disabling the support to release the rod

1985-01-24

 
 
 
 
301

[Diaphragmatic fatigue and its recovery are influenced by markedly decreased cardiac output: possible involvement of neuromuscular junction].  

Science.gov (United States)

Effects of highly decreased cardiac output on the development and recovery of diaphragmatic fatigue were studied in dogs. The fatigue was induced by supramaximal electrical stimulation (20 Hz) of phrenic nerves for 30 minutes. Cardiac output was reduced during this period to 30% of control value by mechanically obstructing inferior vena cava with a balloon in animals with lowered cardiac output group (lowered Qt group). Cardiac output was maintained at normal value throughout the experiment in animals of the other group (control group). The animals were observed for recovery for 60 minutes after induction of the fatigue. The standardized transdiaphragmatic pressure (Pdi/Pdi 100) and integrated electromyographic activity (Edi/Edi 100) elicited by electrical test stimuli (20, 100 Hz) were significantly lower in lowered Qt group (P less than 0.01) during entire fatigue and recovery period. The decrease of Pdi/Pdi 100 and Edi/Edi 100 at high frequency test stimuli (100 Hz) was observed only in lowered Qt group. These results suggest that when cardiac output is severely decreased the diaphragm is more susceptible to fatigue, and that this may be caused by a failure of neuromuscular junction as well as by an impaired excitation-contraction coupling. PMID:1920803

Fujii, Y; Oshima, T; Toyooka, H; Udagawa, T; Ebata, T; Amaha, K

1991-08-01

302

Individuals with medial knee osteoarthritis show neuromuscular adaptation when perturbed during walking despite functional and structural impairments.  

Science.gov (United States)

Neuromuscular control relies on sensory feedback that influences responses to changing external demands, and the normal response is for movement and muscle activation patterns to adapt to repeated perturbations. People with knee osteoarthritis (OA) are known to have pain, quadriceps weakness, and neuromotor deficits that could affect adaption to external perturbations. The aim of this study was to analyze neuromotor adaptation during walking in people with knee OA (n = 38) and controls (n = 23). Disability, quadriceps strength, joint space width, malalignment, and proprioception were assessed. Kinematic and EMG data were collected during undisturbed walking and during perturbations that caused lateral translation of the foot at initial contact. Knee excursions and EMG magnitudes were analyzed. Subjects with OA walked with less knee motion and higher muscle activation and had greater pain, limitations in function, quadriceps weakness, and malalignment, but no difference was observed in proprioception. Both groups showed increased EMG and decreased knee motion in response to the first perturbation, followed by progressively decreased EMG activity and increased knee motion during midstance over the first five perturbations, but no group differences were observed. Over 30 trials, EMG levels returned to those of normal walking. The results illustrate that people with knee OA respond similarly to healthy individuals when exposed to challenging perturbations during functional weight-bearing activities despite structural, functional, and neuromotor impairments. Mechanisms underlying the adaptive response in people with knee OA need further study. PMID:24072409

Kumar, Deepak; Swanik, Charles Buz; Reisman, Darcy S; Rudolph, Katherine S

2014-01-01

303

Epigenetic Control of the Immune Escape Mechanisms in Malignant Carcinomas?  

Science.gov (United States)

Downregulation of the transporter associated with antigen processing 1 (TAP-1) has been observed in many tumors and is closely associated with tumor immunoevasion mechanisms, growth, and metastatic ability. The molecular mechanisms underlying the relatively low level of transcription of the tap-1 gene in cancer cells are largely unexplained. In this study, we tested the hypothesis that epigenetic regulation plays a fundamental role in controlling tumor antigen processing and immune escape mechanisms. We found that the lack of TAP-1 transcription in TAP-deficient cells correlated with low levels of recruitment of the histone acetyltransferase, CBP, to the TAP-1 promoter. This results in lower levels of histone H3 acetylation at the TAP-1 promoter, leading to a decrease in accessibility of the RNA polymerase II complex to the TAP-1 promoter. These observations suggest that CBP-mediated histone H3 acetylation normally relaxes the chromatin structure around the TAP-1 promoter region, allowing transcription. In addition, we found a hitherto-unknown mechanism wherein interferon gamma up-regulates TAP-1 expression by increasing histone H3 acetylation at the TAP-1 promoter locus. These findings lie at the heart of understanding immune escape mechanisms in tumors and suggest that the reversal of epigenetic codes may provide novel immunotherapeutic paradigms for intervention in cancer.

Setiadi, A. Francesca; David, Muriel D.; Seipp, Robyn P.; Hartikainen, Jennifer A.; Gopaul, Rayshad; Jefferies, Wilfred A.

2007-01-01

304

Does perioperative tactile evaluation of the train-of-four response influence the frequency of postoperative residual neuromuscular blockade?  

DEFF Research Database (Denmark)

The authors conducted a randomized controlled clinical trial to evaluate the usefulness of perioperative manual evaluation of the response to train-of-four (TOF) nerve stimulation. A total of 80 patients were divided into four groups of 20 each. For two groups (one given vecuronium and one pancuronium), the anesthetists assessed the degree of neuromuscular blockade during operation and during recovery from neuromuscular blockade by manual evaluation of the response to TOF nerve stimulation. In the other two groups, one of which received vecuronium and the other pancuronium, the anesthetists evaluated the degree of neuromuscular blockade solely by clinical criteria. The use of a nerve stimulator was found to have no effect on the dose of relaxant given during anesthesia, on the need for supplementary doses of anticholinesterase in the recovery room, on the time from end of surgery to end of anesthesia, or on the incidence of postoperative residual neuromuscular blockade evaluated clinically. The median (and range of) TOF ratios recorded in the recovery room were 0.75 (0.33-0.96) and 0.79 (0.10-0.97) in the vecuronium groups monitored with and without a nerve stimulator, respectively. These ratios were significantly higher than those found in the pancuronium groups, which wre 0.66 (0.06-0.90) and 0.63 (0.29-0.95), respectively. However, no difference was found between the vecuronium and pancuronium groups in the number of patients showing clinical signs of residual neuromuscular blockade, as evaluated by the 5-s head-lift test.(ABSTRACT TRUNCATED AT 250 WORDS)

Pedersen, T; Viby-Mogensen, J

1990-01-01

305

Controller modeling and evaluation for PCV electro-mechanical actuator  

Science.gov (United States)

Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

Parker, Joey K.

1993-11-01

306

Controller modeling and evaluation for PCV electro-mechanical actuator  

Science.gov (United States)

Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

Parker, Joey K.

1993-01-01

307

Moving constraints as stabilizing controls in classical mechanics  

CERN Document Server

The paper analyzes a Lagrangian system which is controlled by directly assigning some of the coordinates as functions of time, by means of frictionless constraints. In a natural system of coordinates, the equations of motions contain terms which are linear or quadratic w.r.t.time derivatives of the control functions. After reviewing the basic equations, we explain the significance of the quadratic terms, related to geodesics orthogonal to a given foliation. We then study the problem of stabilization of the system to a given point, by means of oscillating controls. This problem is first reduced to the weak stability for a related convex-valued differential inclusion, then studied by Lyapunov functions methods. In the last sections, we illustrate the results by means of various mechanical examples.

Bressan, A

2008-01-01

308

Breath stacking in children with neuromuscular disorders.  

Science.gov (United States)

Respiratory muscle weakness in neuromuscular disorders (NMD) can lead to shallow breathing and respiratory insufficiency over time. Children with NMD often cannot perform maneuvers to recruit lung volume. In adults, breath stacking with a mask and one-way valve can achieve significantly increased lung volumes. To evaluate involuntary breath stacking (IBS) in NMD, we studied 23 children of whom 15 were cognitively aware and able to communicate verbally. For IBS, a one-way valve and pneumotachograph were attached to a face mask. Tidal volumes (Vt) and minute ventilation (VE ) were calculated from airflow over 30?sec before and after 15?sec of expiratory valve closure. Six cooperative male subjects with Duchenne muscular dystrophy (DMD) participated in a subsequent comparison of IBS with voluntary breath stacking (VBS) and supported breath stacking (SBS). The average Vt in those studied with IBS was 277?ml (range 29-598?ml). The average increase in volume by stacking was 599?ml (range -140 to 2,916?ml) above Vt . The average number of stacked breaths was 4.5 (range 0-17). VE increased on average by 18% after stacking (P?

Jenkins, H M; Stocki, A; Kriellaars, D; Pasterkamp, H

2014-06-01

309

N-glycosylation requirements in neuromuscular synaptogenesis.  

Science.gov (United States)

Neural development requires N-glycosylation regulation of intercellular signaling, but the requirements in synaptogenesis have not been well tested. All complex and hybrid N-glycosylation requires MGAT1 (UDP-GlcNAc:?-3-D-mannoside-?1,2-N-acetylglucosaminyl-transferase I) function, and Mgat1 nulls are the most compromised N-glycosylation condition that survive long enough to permit synaptogenesis studies. At the Drosophila neuromuscular junction (NMJ), Mgat1 mutants display selective loss of lectin-defined carbohydrates in the extracellular synaptomatrix, and an accompanying accumulation of the secreted endogenous Mind the gap (MTG) lectin, a key synaptogenesis regulator. Null Mgat1 mutants exhibit strongly overelaborated synaptic structural development, consistent with inhibitory roles for complex/hybrid N-glycans in morphological synaptogenesis, and strengthened functional synapse differentiation, consistent with synaptogenic MTG functions. Synapse molecular composition is surprisingly selectively altered, with decreases in presynaptic active zone Bruchpilot (BRP) and postsynaptic Glutamate receptor subtype B (GLURIIB), but no detectable change in a wide range of other synaptic components. Synaptogenesis is driven by bidirectional trans-synaptic signals that traverse the glycan-rich synaptomatrix, and Mgat1 mutation disrupts both anterograde and retrograde signals, consistent with MTG regulation of trans-synaptic signaling. Downstream of intercellular signaling, pre- and postsynaptic scaffolds are recruited to drive synaptogenesis, and Mgat1 mutants exhibit loss of both classic Discs large 1 (DLG1) and newly defined Lethal (2) giant larvae [L(2)GL] scaffolds. We conclude that MGAT1-dependent N-glycosylation shapes the synaptomatrix carbohydrate environment and endogenous lectin localization within this domain, to modulate retention of trans-synaptic signaling ligands driving synaptic scaffold recruitment during synaptogenesis. PMID:24227656

Parkinson, William; Dear, Mary Lynn; Rushton, Emma; Broadie, Kendal

2013-12-01

310

Is there a role for selective anterior instrumentation in neuromuscular scoliosis?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our objective was to report on the clinical and radiological outcome from a cohort of patients with neuromuscular scoliosis who underwent selective anterior single rod instrumentation for correction of thoraco-lumbar and lumbar scoliosis. Traditionally combined anterior release with long posterior instrumentation has been advocated for the treatment of neuromuscular scoliosis. Neuromuscular curves tend to be long and may have significant pelvic obliquity. However, certain neuromuscular curves...

Tokala, Devi Prakash; Lam, Khai S.; Freeman, Brian J. C.; Webb, John K.

2007-01-01

311

Fibromatosis arising in association with neuromuscular hamartoma of the mandible.  

Science.gov (United States)

Aggressive fibromatosis is a benign but locally-aggressive tumor, which most often affects the muscles of the shoulder, the pelvic girdle, and the thigh. It usually affects adolescents and young adults. Desmoplastic fibroma, considered the bone counterpart of soft tissue fibromatosis, is a rare tumor that usually affects the metaphyseal or diaphyseal portions of long bones or, less commonly, the jaw. Neuromuscular hamartoma, a rare developmental lesion composed of mature elements of both striated muscle and nerve, is usually diagnosed in infants and children and affects large nerve trunks. Rarely, it can affect the head and neck region. Occasional cases showing an association between aggressive fibromatosis and neuromuscular hamartoma have been reported in the literature. Here we present a unique case of an adult patient with desmoplastic fibroma of the mandible in association with neuromuscular hamartoma. PMID:23315379

Taher, Leena Yaseen; Saleem, Muhammad; Velagapudi, Suresh; Dababo, Anas

2013-09-01

312

The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Lower limb injuries in sport are increasingly prevalent and responsible for large economic as well as personal burdens. In this review we seek to determine which easily implemented functional neuromuscular warm-up strategies are effective in preventing lower limb injuries during sports participation and in which sporting groups they are effective. Methods Seven electronic databases were searched from inception to January 2012 for studies investigating neuromuscular warm-up strategies and injury prevention. The quality of each included study was evaluated using a modified version of the van Tulder scale. Data were extracted from each study and used to calculate the risk of injury following application of each evaluated strategy. Results Nine studies were identified including six randomized controlled trials (RCT and three controlled clinical trials (CCT. Heterogeneity in study design and warm-up strategies prevented pooling of results. Two studies investigated male and female participants, while the remaining seven investigated women only. Risk Ratio (RR statistics indicated 'The 11+' prevention strategy significantly reduces overall (RR 0.67, confidence interval (CI 0.54 to 0.84 and overuse (RR 0.45, CI 0.28 to 0.71 lower limb injuries as well as knee (RR 0.48, CI 0.32 to 0.72 injuries among young amateur female footballers. The 'Knee Injury Prevention Program' (KIPP significantly reduced the risk of noncontact lower limb (RR 0.5, CI 0.33 to 0.76 and overuse (RR 0.44, CI 0.22 to 0.86 injuries in young amateur female football and basketball players. The 'Prevent Injury and Enhance Performance' (PEP strategy reduces the incidence of anterior cruciate ligament (ACL injuries (RR 0.18, CI 0.08 to 0.42. The 'HarmoKnee' programme reduces the risk of knee injuries (RR 0.22, CI 0.06 to 0.76 in teenage female footballers. The 'Anterior Knee Pain Prevention Training Programme' (AKP PTP significantly reduces the incidence of anterior knee pain (RR 0.27, CI 0.14 to 0.54 in military recruits. Conclusions Effective implementation of practical neuromuscular warm-up strategies can reduce lower extremity injury incidence in young, amateur, female athletes and male and female military recruits. This is typically a warm-up strategy that includes stretching, strengthening, balance exercises, sports-specific agility drills and landing techniques applied consistently for longer than three consecutive months. In order to optimize these strategies, the mechanisms for their effectiveness require further evaluation.

Herman Katherine

2012-07-01

313

Aberrant Morphology and Residual Transmitter Release at the Munc13-Deficient Mouse Neuromuscular Synapse†  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In cultured hippocampal neurons, synaptogenesis is largely independent of synaptic transmission, while several accounts in the literature indicate that synaptogenesis at cholinergic neuromuscular junctions in mammals appears to partially depend on synaptic activity. To systematically examine the role of synaptic activity in synaptogenesis at the neuromuscular junction, we investigated neuromuscular synaptogenesis and neurotransmitter release of mice lacking all synaptic vesicle priming protei...

2005-01-01

314

Eletroestimulação neuromuscular, exercícios contrarresistência, força muscular, dor e função motora em pacientes com osteoartrite primária de joelho / Neuromuscular electrical stimulation, exercises against resistance, muscle strength, pain, and motor function in patients with primary osteoarthritis of the knee  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese INTRODUÇÃO: A osteoartrite (OA) do joelho é um processo degenerativo e os sintomas são dor mecânica e períodos de dor inflamatória, rigidez articular e fraqueza muscular. Ela não tem cura. O objetivo do tratamento é aliviar os sinais e sintomas e, quando possível, retardar sua evolução. O fortalecim [...] ento muscular é indicado como tratamento da OA. OBJETIVO: Comparar a eficácia da eletroestimulação neuromuscular (EENM) e de exercícios contrarresistência (ECR) no ganho de força extensora de joelho, na diminuição da dor e na recuperação da função motora em pacientes com OA primária do joelho. MATERIAIS E MÉTODOS: Participaram da pesquisa 23 pacientes com diagnóstico de OA primária do joelho, segundo os critérios clínicos e radiológicos do American College of Rheumatology. Eles foram alocados aleatoriamente para um grupo de ECR (n = 9), um grupo de EENM (n = 8) e um grupo controle (n = 6), e foram submetidos aos procedimentos característicos de seu grupo três vezes por semana até completar 24 sessões. Foram avaliadas de forma cega a força extensora de joelho, a dor e a função motora. Foi utilizado o teste MANOVA 3 x 2 com medidas repetidas para P Abstract in english INTRODUCTION: Knee osteoarthritis (OA) is a degenerative and the symptoms are mechanical pain and periods of inflammatory pain, joint stiffness and muscle weakness. OA has no cure and treatment serves to relieve the signs and symptoms and, when they can, slow its progression. Muscle strengthening is [...] indicated as the treatment. OBJECTIVE: To compare the effectiveness of NMES and resistance exercise in knee extensor strength gain, pain reduction and recovery of motor function in patients diagnosed with primary osteoarthritis of the knee. MATERIALS AND METHODS: Participated 23 patients with primary knee osteoarthritis, according to the clinical and radiological criteria of the American College of Rheumatology. Patients were randomly assigned to a group of resistance exercise (ECR n = 9), a group of neuromuscular electrical stimulation (NMES n = 8) and a control group (n = 6). They underwent characteristic procedures of their group three times per week until 24 sessions. The knee extensor strength pain and function were evaluated. Statistical analyses used was a 3 x 2 MANOVA with repeated measures, P

Dadalto, Thais Varanda; Souza, Cintia Pereira de; Silva, Elirez Bezerra da.

315

Sodium cooled CANDLE reactor equipped with reactivity control mechanism  

International Nuclear Information System (INIS)

In series of the study on CANDLE reactor, a design specification of sodium cooled, metal fuel, 2000 MWt rating CANDLE core has been presented. The core satisfies engineering design criteria including cladding temperature, pressure drop, linear heat rate, cumulative damage fraction (CDF) of cladding, fast neutron fluence and sodium void reactivity which are defined in the Japanese FBR design project. Some distinctive features of CANDLE such as >30% of burnup without recycling, no need for enrichment and reprocessing processes by generating necessary fissile by itself are attributed to its superior breeding capability. It is enabled by very hard neutron spectrum that the fraction of fast neutrons (>0.1 MeV) is no less than 73.5%. The process of cladding replacement while keeping the shape and composition of fuel materials inside is called recladding. The recladding have to be implemented every 6.4 years if the core uses HT-9 for cladding material. During normal operation CANDLE core requires no reactivity control mechanism, it must be however considered in its realistic design to control reactivity change in case of startup, shutdown, transient condition and also to compensate uncertainties ascribed to errors in nuclear data, in fabrication process. Therefore a concrete design of CANDLE core equipped with reactivity control mechanism is studied by considering necessary reactivity worth. (author)

2011-12-11

316

Phloem transport: a review of mechanisms and controls.  

Science.gov (United States)

It is generally believed that an osmotically generated pressure gradient drives the phloem mass flow. So far, this widely accepted Münch theory has required remarkably few adaptations, but the debate on alternative and additional hypotheses is still ongoing. Recently, a possible shortcoming of the Münch theory has been pointed out, suggesting that the Münch pressure flow is more suitable for herbs than for trees. Estimation of the phloem resistance indicates that a point might be reached in long sieve tubes where the pressure required to drive the Münch flow cannot be generated. Therefore, the relay hypothesis regained belief as it implies that the sieve tubes are shorter then the plant's axial axis. In the source phloem, three different loading strategies exist which probably result from evolutionary advantages. Passive diffusion seems to be the most primitive one, whereas active loading strategies substantially increase the growth potential. Along the transport phloem, a leakage-retrieval mechanism is observed. Appreciable amounts of carbohydrates are lost from the sieve tubes to feed the lateral sinks, while a part of these lost carbohydrates is subsequently reloaded into the sieve tubes. This mechanism is probably involved to buffer short-term irregularities in phloem turgor and gradient. In the long term, the mechanism controls the replenishment and remobilization of lateral stem storage tissues. As phloem of higher plants has multiple functions in plant development, reproduction, signalling, and growth, the fundamental understanding of the mechanisms behind phloem transport should be elucidated to increase our ability to influence plant growth and development. PMID:24106290

De Schepper, Veerle; De Swaef, Tom; Bauweraerts, Ingvar; Steppe, Kathy

2013-11-01

317

Perioperative respiratory management of pediatric patients with neuromuscular disease.  

Science.gov (United States)

Patients with neuromuscular disorders undergoing general anesthesia present a special set of respiratory problems for perioperative management. While there are disease-specific concerns, there are many common themes in the respiratory management of patients with neuromuscular disorders. These problems are discussed in this review. Such common perioperative concerns include upper airway obstruction, chest wall restriction, postoperative hypoventilation, inadequate airway clearance, and chronic lower airway disease. Each of these challenges has an effective management approach, and careful planning can help avoid perioperative respiratory complications. PMID:23763308

Blatter, Joshua A; Finder, Jonathan D

2013-09-01

318

Joint moment control of mechanical energy flow during normal gait.  

Science.gov (United States)

The study purpose was to estimate the ability of joint moments to transfer mechanical energy through the leg and trunk during gait. A segmental power analysis of five healthy adult subjects revealed that internal joint extensor moments removed energy from the leg and added energy to the trunk, while flexor moments and gravity produced the opposite effects. The only exception to this pattern was during the push off phase of gait when the ankle plantar flexor moment added energy to both the leg and the trunk. Pairs of joint moments with opposite energetic effects (knee extensor vs gravity, hip flexor vs ankle plantar flexor) worked together to balance energy flows through the segments. This intralimb coordination suggests that moments with contradictory effects are generated simultaneously to control mechanical energy flow within the body during walking. PMID:14741305

Siegel, Karen Lohmann; Kepple, Thomas M; Stanhope, Steven J

2004-02-01

319

Peripheral and central nervous system mechanisms of joint protection.  

Science.gov (United States)

Although there are many risk factors (such as age, family history, and obesity) associated with the development of osteoarthritis (OA), only trauma is known to cause OA. The neuromuscular system controls the amount and kind of movement occurring at a joint, so it is this system that is uitimately responsible for ensuring that joint tissues are not damaged to the point of developing OA during normal day-to-day activities. In the present paper, we review and critically evaluate some of the current concepts of the role of peripheral and central nervous system mechanisms that might protect joints from excessive excursion and joint tissues from excessive loading and OA. We conclude that a neuromuscular protective model based on central pattern generators (CPGs--subconscious motor programs) can best reconcile much heretofore ambiguous information pertaining to the development and progression of OA in stable and unstable joints. PMID:12892277

O'Connor, Brian L; Vilensky, Joel A

2003-07-01

320

A cognitive intersensory interaction mechanism in human postural control.  

Science.gov (United States)

Human control of upright body posture involves inputs from several senses (visual, vestibular, proprioceptive, somatosensory) and their central interactions. We recently studied visual effects on posture control and their intersensory interactions and found evidence for the existence of an indirect and presumably cognitive mode of interaction, in addition to a direct interaction (we found, e.g., that a 'virtual reality' visual stimulus has a weaker postural effect than a 'real world' scene, because of its illusory character). Here we focus on the presumed cognitive interaction mechanism. We report experiments in healthy subjects and vestibular loss patients. We investigated to what extent a postural response to lateral platform tilt is modulated by tilt of a visual scene in an orthogonal rotational plane (anterior-posterior, a-p, direction). The a-p visual stimulus did not evoke a lateral postural response on its own. But it enhanced the response to the lateral platform tilt (i.e., it increased the evoked body excursion). The effect was related to the velocity of the visual stimulus, showed a threshold at 0.31 degrees /s, and increased monotonically with increasing velocity. These characteristics were similar in normals and patients, but body excursions were larger in patients. In conclusion, the orthogonal stimulus arrangement in our experiments allowed us to selectively assess a cognitive intersensory interaction that upon co-planar stimulation tends to be merged with direct interaction. The observed threshold corresponds to the conscious perceptual detection threshold of the visual motion, which is clearly higher than the visual postural response threshold. This finding is in line with our notion of a cognitive phenomenon. We postulate that the cognitive mechanism in normals interferes with a central visual-vestibular interaction mechanism. This appears to be similar in vestibular loss patients, but patients use less effective somatosensory instead of vestibular anti-gravity mechanisms. PMID:16491407

Blümle, A; Maurer, C; Schweigart, G; Mergner, T

2006-08-01

 
 
 
 
321

Estudio electromiográfico de fibra aislada en enfermedades neuromusculares / Single fiber electromyographic study in neuromuscular diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se implementó la electromiografía de fibra aislada en la práctica asistencial. Se realizó el estudio electromiográfico de fibra aislada de 191 pacientes con enfermedades neuromusculares. Se obtuvo una positividad de los estudios en el grupo de las radiculopatías de C6 del 15,2 %, para las lesiones d [...] el plexo braquial del 33, 3 %, para la esclerosis lateral amiotrófica del 44,1 %, para las miopatías del 21,9 % y se destaca la sensibilidad del mismo en el grupo de pacientes de miastenia gravis, que llegó al 70 %. Se concluye que se ratifica la alta sensibilidad del método de electromiografía de fibra aislada en el diagnóstico de la miastenia gravis y se señala su positividad moderada o baja en el resto de las enfermedades estudiadas. Abstract in english The single fiber electromyography was implemented in the health care practice. The single fiber electromyographic study of 191 patients with neuromuscular diseases was carried out. It was obtained a positivity of 15,2 % in the studies conducted in the group of C6 radiculopathies; 33,3 % in the brach [...] ial plexus injuries; 44,1 % in the amyotrophic lateral sclerosis; and 21,9 % in the myopathies. Its sensitivity was stressed in the group of patients with myasthenia gravis that reached 70 %. To conclude, it was ratified the high sensitivity of the method of single fibre electromyography in the diagnosis of myasthenia gravis, and it was underlined its moderate or low positivity in the rest of the studied diseases.

Álvarez Fiallo, Roger; Santos Anzorandia, Carlos; Medina Herrera, Esther; Jiménez Paneque, Rosa; Gutiérrez Sánchez, Ángela.

322

Dolor en niños y adolescentes con enfermedades neuromusculares / Pain in children and adolescents with neuromuscular diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish El objetivo de este trabajo es revisar la información disponible sobre la experiencia de dolor en niños y adolescentes con una enfermedad neuromuscular (ENM). Para ello, se examinaron las bases de datos SCOPUS y MEDLINE y se localizaron los artículos publicados sobre el tema hasta marzo de 2012. Tra [...] s un análisis exhaustivo, se identificaron 33 artículos que cumplían con los criterios de inclusión. Del análisis efectuado se desprende que el dolor es una experiencia muy habitual en estos jóvenes, que se trata de molestias, por lo general, de moderadas a severas, con una alta frecuencia de aparición y de larga duración. Habitualmente se trata de cuadros crónicos. Estos problemas afectan a la calidad de vida de los jóvenes, más allá de lo que puede explicar la propia ENM. Los estudios revisados muestran que no solo la calidad de vida de los jóvenes se ve afectada por la presencia del dolor, también la de sus cuidadores. Abstract in english The aim of this paper is to review the available information on the experience of pain in children and adolescents with neuromuscular disease (NMD). In order to do this, we examined the MEDLINE and SCOPUS databases and located published articles on the subject until March 2012. After a thorough anal [...] ysis, we identified 33 articles that met the inclusion criteria. The analysis conducted shows that pain is a very common experience for these young people, usually moderate to severe, with a high frequency of occurrence and long lasting. In general, these are chronic conditions. These chronic pain problems affect the quality of life of young people, beyond what could be explained by the NMD alone. The reviewed studies show that pain not only negatively impacts the quality of life of young people, also that of their caregivers is at jeopardy.

López, M.; Miró, J..

323

Rod drive mechanism with screw and nut for reactor control  

International Nuclear Information System (INIS)

Screw and nut mechanism for controlling a nuclear reactor by vertical travel of an assembly absorbing the neutrons in the reactor core and drop of this absorbing assembly in maximum insertion position under its own weight, for reactor scram. It comprises a mobile screw in translation, the lower end of which can be connected to the absorbing assembly through a linking rod and a fixed nut in translation, mobile in rotation, secured to the lower end of a screw holding tube, the upper end of which comprises gear for hooking the claws of the grab for holding the screw-nut assembly in vertical position

1981-01-01

324

Electromagnetic control rod drive mechanism, with reduced heat losses  

International Nuclear Information System (INIS)

The electromagnetic device can be used for the control rod drive mechanism of a pressurized coater reactor. It has a sealed casing extending from the reactor cover containing two mobile poles and a mobile plunger, a coil moving the first pole to grip or release the rod, a second coil moving the plunger against the second pole to grip the rod, a third coil moving the second pole, and a cut-out for a thermal coolant siphon associated with the first pole and coil

1985-01-29

325

Bellows for control rod drive mechanism of 'MONJU'  

International Nuclear Information System (INIS)

The full mock-up operation test of Control Rod Drive Mechanism (CRDM) for ''MONJU'' have been carried on since 1972 in OEC of PNC. Welded type bellows were adopted for CRDM as the boundary between sodium and atmosphere. In design, two different locations were considered for bellows, one in sodium and the other in argon gas with sodium vapor and some experiences on the bellows have been obtained. Besides the prototype tests of CRDM, several R and D on CRDM bellows, such as environment effect test and endurance test are conducted. (author)

1979-01-01

326

Bellows for control rod drive mechanisms of 'MONJU'  

International Nuclear Information System (INIS)

The full mock-up operation test of Control Rod Drive Mechanism (CRDM) for 'MONJU' has been carried out since 1972 in OEC of PNC. Welded type bellows were adopted for CRDM as the boundary between sodium and atmosphere. In design, two different locations were considered for bellows, one in sodium and the other in argon gas with sodium vapor and some experiences on the bellows have been obtained. Besides the prototype tests of CRDM, several R and D on CRDM bellows, such as environment effect test and endurance test are conducted. (author)

1980-02-01

327

Web-based neuromuscular simulator applied to the teaching of principles of neuroscience  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english INTRODUCTION: The learning of core concepts in neuroscience can be reinforced by a hands-on approach, either experimental or computer-based. In this work, we present a web-based multi-scale neuromuscular simulator that is being used as a teaching aid in a campus-wide course on the Principles of Neur [...] oscience. METHODS: The simulator has several built-in individual models based on cat and human biophysics, which are interconnected to represent part of the neuromuscular system that controls leg muscles. Examples of such elements are i) single neurons, representing either motor neurons or interneurons mediating reciprocal, recurrent and Ib inhibition; ii) afferent fibers that can be stimulated to generate spinal reflexes; iii) muscle unit models, generating force and electromyogram; and iv) stochastic inputs, representing the descending volitional motor drive. RESULTS: Several application examples are provided in the present report, ranging from studies of individual neuron responses to the collective action of many motor units controlling muscle force generation. A subset of them was included in an optional homework assignment for Neuroscience and Biomedical Engineering graduate students enrolled in the course cited above at our University. Almost all students rated the simulator as a good or an excellent learning tool, and approximately 90% declared that they would use the simulator in future projects. CONCLUSION: The results allow us to conclude that multi-scale neuromuscular simulator is an effective teaching tool. Special features of this free teaching resource are its direct usability from any browser (http://remoto.leb.usp.br/), its user-friendly graphical user interface (GUI) and the preset demonstrations.

Elias, Leonardo Abdala; Kohn, André Fabio.

328

Digital PI Controller Using Anti-Wind-Up Mechanism for A Speed Controlled Electric Drive System  

Directory of Open Access Journals (Sweden)

Full Text Available This paper discusses the implementation of Digital PI Controller Using Anti Wind-Up Mechanism For A Speed Controlled Electric Drive System. To eliminate the system zeros relocated proportional integral controller is implemented. Which in turn reduces the over shoots. The torque is not limited, inspite of the use of relocated proportional integral controller. The motor windings get damaged, if the torque reaches higher values. In order to limit this torque, we introduce a torque limiter, which limits the torque value to the permissible limits. Due to limited torque, over shoots are produced for large inputs. To eliminate these overshoots, with limited torque, we implement the anti-windup mechanism. The scheme is implemented in MATLAB and from the obtained results its possible use and limitations are studied for torque limits varying from +3000 to +7000 N-m.

Srikanth Mandarapu,

2013-06-01

329

Radon mitigation with pressure-controlled mechanical ventilation  

International Nuclear Information System (INIS)

Effective ventilation and positive or low negative pressure indoors are suggested to achieve low indoor radon levels. The aim of this study was to develop and to test equipment which makes it possible to achieve simultaneously effective ventilation and minimum indoor-outdoor pressure difference. The unit included mechanical supply and exhaust air fans, a heat-exchanger and a pressure control unit in direct digital control (DDC), which continuously adjusted air flows based on the pressure difference transmitter information. Indoor radon level decreased from 501 ± 95 Bq/m3 to 202 ± 54 Bq/m3 after two weeks of the equipment's installation during winter conditions. The arithmetic week average of indoor radon level was 135 Bq/m3 from May to August. When the set value of pressure difference adjustment was slightly positive (0.2 Pa) and in-out temperature difference was small in August, the minimum level (38 ± 28 Bq/m3) was obtained. (author)

1994-01-01

330

Tracking control mechanisms for positioning automatic CRD exchanger  

International Nuclear Information System (INIS)

Purpose: To enable completely automatic positioning for the automatic CRD (control rod drives) exchanger, as well as shorten the time for the exchanging operation and save the operator's labour. Constitution: Images of a target attached to the lower flange face of CRD are picked up by a fiber scope mounted to a mounting head. The images are converted through I.T.V. into electrical signals, passed through a cable and then sent to a pattern recognition mechanism. The position for the images of the target is calculated and the calculated position is sent to a drive control section, where the position for the images of the target is compared with a reference position for the images (exactly aligned position) and the moving amount of the mounting head is calculated to move the driving section and thereby complete the positioning. (Kawakami, Y.)

1983-03-18

331

Uranium dioxide sintering Kinetics and mechanisms under controlled oxygen potentials  

International Nuclear Information System (INIS)

The initial, intermediate, and final sintering stages of uranium dioxide were investigated as a function of stoichiometry and temperature by following the kinetics of the sintering reaction. Stoichiometry was controlled by means of the oxygen potential of the sintering atmosphere, which was measured continuously by solid-state oxygen sensors. Included in the kinetic study were microspheres originated from UO2 gels and UO2 pellets produced by isostatic pressing ceramic grade powders. The microspheres sintering behavior was examined using hot-stage microscopy and a specially designed high-temperature, controlled atmosphere furnace. This same furnace was employed as part of an optical dilatometer, which was utilized in the UO2 pellet sintering investigations. For controlling the deviations from stoichiometry during heat treatment, the oxygen partial pressure in the sintering atmosphere was varied by passing the gas through a Cu-Ti-Cu oxygen trap. The trap temperature determined the oxygen partial pressure of the outflowing mixture. Dry hydrogen was also used in some of the UO sub(2+x) sintering experiments. The determination of diametrial shrinkages and sintering indices was made utilizing high-speed microcinematography and ultra-microbalance techniques. It was observed that the oxygen potential has a substantial influence on the kinetics of the three sintering stages. The control of the sintering atmosphere oxygen partial pressure led to very fast densification of UO sub(2+x). Values in the interval 95.0 to 99.5% of theoretical density were reached in less than one minute. Uranium volume diffusion is the dominant mechanism in the initial and intermediate sintering stages. For the final stage, uranium grain boundary diffusion was found to be the main sintering mechanism. (Author)

1980-01-01

332

Eustatic control of gravity tectonics: Concept, mechanism and limits  

Energy Technology Data Exchange (ETDEWEB)

Gravity tectonics over a ductile decollement characterizes deformation of the Albian to Recent section in the West African margin, from Gabon to Angola. Largely studied during the past 20 years as a prolific petroleum play, it is now well known that three mains factors will control gravity driven deformation: the ductile layer, the slope as a response to the crustal activity and the overlying sedimentary loading. For the West African passive margin, the slope effect at the first glance can be considered as constant and gravity driven deformation as a result of salt layer distribution (in time and space) and sedimentary loading. If previous papers have already shown that the type and distribution of the deposits control the development of the classical structural domains : updip extensional to downdip contractional, this study will focused on the factor which control the sedimentary loading. Based on several natural examples combining seismic stratigraphy, sequential stratigraphy and structural studies and also analogical modelling, it is demonstrated that: (1) as sediment distribution and then sedimentary loading is controlled by relative sea level changes, thus sea level changes can be directly related to gravity driven deformation : large sea level fall will provide an important increase of clastics supply which will enhanced gravity gliding. On the contrary, relative sea level high will stop the deformation because of the decreasing amount of detritics and their homogeneous distribution. (2) the salt downdip withdrawal during extension will enhance the eustatic effect. (3) episodic crustal activity, materialized by westward tilting of the margin will interfere on this mechanism.

Raillard, S.; Allix, P.; Guerin, G.; Lecanu, H. [Elf Aquitaine Production, Pau (France)] [and others

1996-12-31

333

A Cell-Level Mechanism of Contrast Gain Control  

CERN Document Server

The gain of neurons' responses in the auditory cortex is sensitive to contrast changes in the stimulus within a spectrotemporal range similar to their receptive fields, which can be interpreted to represent the tuning of the input to a neuron. This indicates a local mechanism of contrast gain control, which we explore with a minimal mechanistic model here. Gain control through noisy input has been observed in vitro and in a range of computational models. We investigate the behaviour of the simplest of such models to showcase gain control, a stochastic leaky integrate-and-fire (sLIF) neuron, which exhibits gain control through divisive normalisation of the input both with and without accompanying subtractive shift of the input-response curve, depending on whether input noise is proportional to or independent of its mean. To get a more direct understanding of how the input statistics change the response, we construct an analytic approximation to the firing rate of a sLIF neuron constituted of the expression for...

Schumacher, Linus J

2013-01-01

334

Genetic and evolutionary analysis of the Drosophila larval neuromuscular junction  

Science.gov (United States)

Although evolution of brains and behaviors is of fundamental biological importance, we lack comprehensive understanding of the general principles governing these processes or the specific mechanisms and molecules through which the evolutionary changes are effected. Because synapses are the basic structural and functional units of nervous systems, one way to address these problems is to dissect the genetic and molecular pathways responsible for morphological evolution of a defined synapse. I have undertaken such an analysis by examining morphology of the larval neuromuscular junction (NMJ) in wild caught D. melanogaster as well as in over 20 other species of Drosophila. Whereas variation in NMJ morphology within a species is limited, I discovered a surprisingly extensive variation among different species. Compared with evolution of other morphological traits, NMJ morphology appears to be evolving very rapidly. Moreover, my data indicate that natural selection rather than genetic drift is primarily responsible for evolution of NMJ morphology. To dissect underlying molecular mechanisms that may govern NMJ growth and evolutionary divergence, I focused on a naturally occurring variant in D. melanogaster that causes NMJ overgrowth. I discovered that the variant mapped to Mob2, a gene encoding a kinase adapter protein originally described in yeast as a member of the Mitotic Exit Network (MEN). I have subsequently examined mutations in the Drosophila orthologs of all the core components of the yeast MEN and found that all of them function as part of a common pathway that acts presynaptically to negatively regulate NMJ growth. As in the regulation of yeast cytokinesis, these components of the MEN appear to act ultimately by regulating actin dynamics during the process of bouton growth and division. These studies have thus led to the discovery of an entirely new role for the MEN---regulation of synaptic growth---that is separate from its function in cell division. This work has identified a rich source of material for discovery of novel genes and mechanisms that regulate synaptic growth and development, and has also provided new insights into the mechanisms that underlie morphological evolution of nervous systems.

Campbell, Megan

335

Discrete Mechanics and Optimal Control for Space Trajectory Design  

Science.gov (United States)

Space trajectory design is often achieved through a combination of dynamical systems theory and optimal control. The union of trajectory design techniques utilizing invariant manifolds of the planar circular restricted three-body problem and the optimal control scheme Discrete Mechanics and Optimal Control (DMOC) facilitates the design of low-energy trajectories in the N-body problem. In particular, DMOC is used to optimize a trajectory from the Earth to the Moon in the 4-body problem, removing the mid-course change in velocity, Delta V, usually necessary for such a trajectory while still exploiting the structure from the invariant manifolds. This thesis also focuses on how to adapt DMOC, a method devised with a constant step size, for the highly nonlinear dynamics involved in trajectory design. Mesh refinement techniques that aim to reduce discretization errors in the solution and energy evolution and their effect on DMOC optimization are explored and compared with trajectories created using time adaptive variational integrators. Furthermore, a time adaptive form of DMOC is developed that allows for a variable step size that is updated throughout the optimization process. Time adapted DMOC is based on a discretization of Hamilton's principle applied to the time adapted Lagrangian of the optimal control problem. Variations of the discrete action of the optimal control Lagrangian lead to discrete Euler-Lagrange equations that can be enforced as constraints for a boundary value problem. This new form of DMOC leads to the accurate and efficient solution of optimal control problems with highly nonlinear dynamics. Time adapted DMOC is tested on several space trajectory problems including the elliptical orbit transfer in the 2-body problem and the reconfiguration of a cubesat.

Moore, Ashley

336

Dynamic Simulation of Hybrid-driven Planar Five-bar Parallel Mechanism Based on SimMechanics and Tracking Control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper investigates dynamic simulation and trajectory tracking control of hybrid?driven planar five?bar parallel mechanism (HPPM). To begin with, a simulation model of dynamics based on MATLAB/SimMechanics is established. Then, traditional PD control and closed loop PD?type iterative learning control of the HPPM are designed. At the end, the simulation based on SimMechanics is carried out, which acquires angular, angular velocity, angular acceleration of two driving link...

Bin Zi; Jianbin Cao; Zhencai Zhu

2011-01-01

337

Sugammadex compared with neostigmine/glycopyrrolate for routine reversal of neuromuscular block: a systematic review and economic evaluation†  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The cost-effectiveness of sugammadex for the routine reversal of muscle relaxation produced by rocuronium or vecuronium in UK practice is uncertain. We performed a systematic review of randomized controlled trials of sugammadex compared with neostigmine/glycopyrrolate and an economic assessment of sugammadex for the reversal of moderate or profound neuromuscular block (NMB) produced by rocuronium or vecuronium. The economic assessment aimed to establish the reduction in recovery time and the ...

Paton, F.; Paulden, M.; Chambers, D.; Heirs, M.; Duffy, S.; Hunter, J. M.; Sculpher, M.; Woolacott, N.

2010-01-01

338

Suramin inhibits the early effects of PLA2 neurotoxins at mouse neuromuscular junctions: A twitch tension study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Several phospholipase A2 (PLA2) neurotoxins from snake venoms can affect acetylcholine release at the neuromuscular junction. In isolated nerve-muscle preparations three distinct phases have been described for this phenomenon: An initial transient decrease in twitch tension; a second facilitatory phase during which twitch height is greater than control twitch height; and the last phase which causes a reduction in twitch height that finally results in paralysis. Suramin has been reported to in...

Fathi, Behrooz; Harvey, Alan L.; Rowan, Edward G.

2011-01-01

339

Mechanism of controlled release kinetics from medical devices  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Utilization of biodegradable polymers for controlled drug delivery has gained immense attention in the pharmaceutical and medical device industry to administer various drugs, proteins and other bio-molecules both systematically and locally to cure several diseases. The efficacy and toxicity of this [...] local therapeutics depends upon drug release kinetics, which will further decide drug deposition, distribution, and retention at the target site. Drug Eluting Stent (DES) presently possesses clinical importance as an alternative to Coronary Artery Bypass Grafting due to the ease of the procedure and comparable safety and efficacy. Many models have been developed to describe the drug delivery from polymeric carriers based on the different mechanisms which control the release phenomenon from DES. Advanced characterization techniques facilitate an understanding of the complexities behind design and related drug release behavior of drug eluting stents, which aids in the development of improved future drug eluting systems. This review discusses different drug release mechanisms, engineering principles, mathematical models and current trends that are proposed for drug-polymer coated medical devices such as cardiovascular stents and different analytical methods currently utilized to probe diverse characteristics of drug eluting devices.

Raval, A.; Parikh, J.; Engineer, C..

340

Neural mechanisms of attentional control in mindfulness meditation  

Directory of Open Access Journals (Sweden)

Full Text Available The scientific interest in meditation and mindfulness practice has recently seen an unprecedented surge. After an initial phase of presenting beneficial effects of mindfulness practice in various domains, research is now seeking to unravel the underlying psychological and neurophysiological mechanisms. Advances in understanding these processes are required for improving and fine-tuning mindfulness-based interventions that target specific conditions such as eating disorders or attention deficit hyperactivity disorders. This review presents a theoretical framework that emphasizes the central role of attentional control mechanisms in the development of mindfulness skills. It discusses the phenomenological level of experience during meditation, the different attentional functions that are involved, and relates these to the brain networks that subserve these functions. On the basis of currently available empirical evidence specific processes as to how attention exerts its positive influence are considered and it is concluded that meditation practice appears to positively impact attentional functions by improving resource allocation processes. As a result, attentional resources are allocated more fully during early processing phases which subsequently enhance further processing. Neural changes resulting from a pure form of mindfulness practice that is central to most mindfulness programs are considered from the perspective that they constitute a useful reference point for future research. Furthermore, possible interrelations between the improvement of attentional control and emotion regulation skills are discussed.

PeterMalinowski

2013-02-01

 
 
 
 
341

Mechanism of controlled release kinetics from medical devices  

Directory of Open Access Journals (Sweden)

Full Text Available Utilization of biodegradable polymers for controlled drug delivery has gained immense attention in the pharmaceutical and medical device industry to administer various drugs, proteins and other bio-molecules both systematically and locally to cure several diseases. The efficacy and toxicity of this local therapeutics depends upon drug release kinetics, which will further decide drug deposition, distribution, and retention at the target site. Drug Eluting Stent (DES presently possesses clinical importance as an alternative to Coronary Artery Bypass Grafting due to the ease of the procedure and comparable safety and efficacy. Many models have been developed to describe the drug delivery from polymeric carriers based on the different mechanisms which control the release phenomenon from DES. Advanced characterization techniques facilitate an understanding of the complexities behind design and related drug release behavior of drug eluting stents, which aids in the development of improved future drug eluting systems. This review discusses different drug release mechanisms, engineering principles, mathematical models and current trends that are proposed for drug-polymer coated medical devices such as cardiovascular stents and different analytical methods currently utilized to probe diverse characteristics of drug eluting devices.

A. Raval

2010-06-01

342

Neuromuscular-skeletal constraints on the acquisition of skill in a discrete torque production task.  

Science.gov (United States)

The organisation of the human neuromuscular-skeletal system allows an extremely wide variety of actions to be performed, often with great dexterity. Adaptations associated with skill acquisition occur at all levels of the neuromuscular-skeletal system although all neural adaptations are inevitably constrained by the organisation of the actuating apparatus (muscles and bones). We quantified the extent to which skill acquisition in an isometric task set is influenced by the mechanical properties of the muscles used to produce the required actions. Initial performance was greatly dependent upon the specific combination of torques required in each variant of the experimental task. Five consecutive days of practice improved the performance to a similar degree across eight actions despite differences in the torques required about the elbow and forearm. The proportional improvement in performance was also similar when the actions were performed at either 20 or 40% of participants' maximum voluntary torque capacity. The skill acquired during practice was successfully extrapolated to variants of the task requiring more torque than that required during practice. We conclude that while the extent to which skill can be acquired in isometric actions is independent of the specific combination of joint torques required for target acquisition, the nature of the kinetic adaptations leading to the performance improvement in isometric actions is influenced by the neural and mechanical properties of the actuating muscles. PMID:17006690

Shemmell, Jonathan; Forner, Matthew; Tathem, Benjamin; Tresilian, James R; Riek, Stephan; Barry, Benjamin K; Carson, Richard G

2006-11-01

343

EFFECTIVENESS OF NEUROMUSCULAR TRAINING FOR BASKET BALL PLAYERS ON PERFORMANCE OF STAR EXCURSION BALANCE TEST  

Directory of Open Access Journals (Sweden)

Full Text Available Background and introduction:To determine the effect of neuromuscular training program (NMTP focused oncore stability and lower extremity strength on performance of star excursion balance test (SEBT inbasketballplayers.Method:: Pre to post test experimental study design randomisedthirty Basketball players each 15 into NMTPand control group. Players trained together as a team in which NMTP group participated 4 weeks of NMTPtwice a week and Control group followed their regular protocol as guided by their coach.Results:When means of post intervention compared using Independent‘t’between NMTP and Control groupthere is no statistically significant difference (p<0.05 in anterior, posterior-medial and posterior-Lateral directionreach distance of star Excursion test but there is a statistically significant difference in means of anterior, posterior-medial and posterior-Lateral direction reach distance when analyzed within in groups using Paired‘t’test andWilcoxon signed rank test.Conclusion:Neuromuscular Training program found to be effective for Basketball Players on Performance ofStar Excursion Balance Test and this improvement can significantly predict the prevention of injury.

Bhargava Kumar Bhaskar

2013-12-01

344

Repouso da junção neuromuscular no tratamento de crises miastênicas e colinérgicas / Management of the myasthenic and cholinergic crisis by neuromuscular junction rest  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os autores trataram 18 crises miastênicas e colinérgicas desenvolvidas em 12 pacientes com forma generalizada e severa de miastenia grave, mediante o "repouso" da junção neuromuscular. Êste foi conseguido, em um grupo de 6 enfermos, pela suspensão das drogas anticolinesterásicas, emprego da respiraç [...] ão artificial e alimentação por sonda nasogástrica ? "repouso relativo". Outro grupo de 6 pacientes foi submetido ao "repouso absoluto" da junção neuromuscular, mediante o uso da respiração artificial, alimentação por sonda nasogástrica e curarização prolongada pela galamina. Em mais de 50% das crises observaram-se melhoras imediatas e acentuadas com o método de tratamento pelo "repouso" da junção neuromuscular, ao lado de redução significativa da taxa de mortalidade nas crises. A evolução mostrou que os pacientes que responderam melhor durante e logo após o tratamento da crise, tiveram, também, melhor evolução ulterior. Dos 12 enfermos somente um era portador de timoma e, mesmo nesse paciente, a evolução foi satisfatória. A sensibilidade inicial ao curare foi muito grande em todos os doentes submetidos à curarização prolongada, mas, em prazo relativamente curto (alguns dias), esta hipersensibilidade diminuiu sensivelmente. Apesar de todos os cuidados, as infecções respiratórias foram a regra, exigindo tratamento enérgico e bem orientado. Abstract in english The neuromuscular junction rest method was employed in the treatment of 18 myasthenic and cholinergic crisis occurring in 12 patients with severe forms of myasthenia gravis. Six of these patients received a "relative rest" and other six patients received an "absolute rest" treatment. In the first gr [...] oup of patients the method consisted essentially in withdrawal of anticholinesterase therapy and mechanical respiratory support with early performance of traqueostomy and use of the intermitente positive pressure breathing (I.P.P.B.) with cuffed traqueostomy tube. The patients of second group, in addition to this management, were submitted to prolonged curarization by galamine (Flaxedil by intramuscular injection); all of them presented an initial curare supersensitivity which always decreased shortly. In both methods the reinstitution of the drug therapy was progressive. The respirator weanned of progressively and the patients were kept under observation for adequate ventilation. The doses were variable but subsequent doses of antimyasthenic medications were determined by clinical findings and response to the tensilon or prostigmine tests. The doses were increased or decreased accordingly in each individual case, rapid changes of drug doses to perfect adjustment being undesirable in this transition period. Partial or temporary remission occurred in some patients. Others were able to sustain satisfactory ventilation for a long period or definitively. Most of the crisis improved and most of the patients benefited from the therapeutic method of the neuromuscular junction rest. There was a remarkable reduction in the mortality rate from the crisis. One patient had a thymoma which was malignant; in spite of this the evolution of this case has been good after the treatment. Those patients who had immediate good response to the treatment of the crisis had a favorable fellow up, even a complete remission. Respiratory infections were very common in spite of all cares. Culture of tracheal secretions and wound exsudates were made. Bactericidal and broad-spectrum antibiotics were used, depending of the laboratory report cf patient's sensitivity. Physiotherapy besides other prophylactic measures was used against bronchopneumonia. Atelectasis was a common complication in the crisis and all efforts to prevent it were made, including daily clinical examination of pulmonary conditions, Vt,, blood pressure and bed side chest films. The routine use of atropine sulfate promoved inspissation of bronchial secretions, plugging of the bronchi, and attendant atelectas

Assis, J. Lamartine de; Saraiva, Paulo A. P..

345

Repouso da junção neuromuscular no tratamento de crises miastênicas e colinérgicas Management of the myasthenic and cholinergic crisis by neuromuscular junction rest  

Directory of Open Access Journals (Sweden)

Full Text Available Os autores trataram 18 crises miastênicas e colinérgicas desenvolvidas em 12 pacientes com forma generalizada e severa de miastenia grave, mediante o "repouso" da junção neuromuscular. Êste foi conseguido, em um grupo de 6 enfermos, pela suspensão das drogas anticolinesterásicas, emprego da respiração artificial e alimentação por sonda nasogástrica — "repouso relativo". Outro grupo de 6 pacientes foi submetido ao "repouso absoluto" da junção neuromuscular, mediante o uso da respiração artificial, alimentação por sonda nasogástrica e curarização prolongada pela galamina. Em mais de 50% das crises observaram-se melhoras imediatas e acentuadas com o método de tratamento pelo "repouso" da junção neuromuscular, ao lado de redução significativa da taxa de mortalidade nas crises. A evolução mostrou que os pacientes que responderam melhor durante e logo após o tratamento da crise, tiveram, também, melhor evolução ulterior. Dos 12 enfermos somente um era portador de timoma e, mesmo nesse paciente, a evolução foi satisfatória. A sensibilidade inicial ao curare foi muito grande em todos os doentes submetidos à curarização prolongada, mas, em prazo relativamente curto (alguns dias, esta hipersensibilidade diminuiu sensivelmente. Apesar de todos os cuidados, as infecções respiratórias foram a regra, exigindo tratamento enérgico e bem orientado.The neuromuscular junction rest method was employed in the treatment of 18 myasthenic and cholinergic crisis occurring in 12 patients with severe forms of myasthenia gravis. Six of these patients received a "relative rest" and other six patients received an "absolute rest" treatment. In the first group of patients the method consisted essentially in withdrawal of anticholinesterase therapy and mechanical respiratory support with early performance of traqueostomy and use of the intermitente positive pressure breathing (I.P.P.B. with cuffed traqueostomy tube. The patients of second group, in addition to this management, were submitted to prolonged curarization by galamine (Flaxedil by intramuscular injection; all of them presented an initial curare supersensitivity which always decreased shortly. In both methods the reinstitution of the drug therapy was progressive. The respirator weanned of progressively and the patients were kept under observation for adequate ventilation. The doses were variable but subsequent doses of antimyasthenic medications were determined by clinical findings and response to the tensilon or prostigmine tests. The doses were increased or decreased accordingly in each individual case, rapid changes of drug doses to perfect adjustment being undesirable in this transition period. Partial or temporary remission occurred in some patients. Others were able to sustain satisfactory ventilation for a long period or definitively. Most of the crisis improved and most of the patients benefited from the therapeutic method of the neuromuscular junction rest. There was a remarkable reduction in the mortality rate from the crisis. One patient had a thymoma which was malignant; in spite of this the evolution of this case has been good after the treatment. Those patients who had immediate good response to the treatment of the crisis had a favorable fellow up, even a complete remission. Respiratory infections were very common in spite of all cares. Culture of tracheal secretions and wound exsudates were made. Bactericidal and broad-spectrum antibiotics were used, depending of the laboratory report cf patient's sensitivity. Physiotherapy besides other prophylactic measures was used against bronchopneumonia. Atelectasis was a common complication in the crisis and all efforts to prevent it were made, including daily clinical examination of pulmonary conditions, Vt,, blood pressure and bed side chest films. The routine use of atropine sulfate promoved inspissation of bronchial secretions, plugging of the bronchi, and attendant atelectasis, infection and bronchopneumonia. Exceptionally, steroids or bronchoscopy had been used.

J. Lamartine de Assis

1968-06-01

346

Rotating stall mechanism and stability control in the pump flows  

International Nuclear Information System (INIS)

Investigations based on experimental measurements and flow dynamics analysis have been completed to reveal the mechanism of flow separations in the pump flow. The possible flow separation including the rotating stall in the vaned diffuser under the normal flow condition has been confirmed to be merely a diffuser effect and caused by the oversized expansion angle of the diffuser. The part load flow separation of both the stationary and the non-stationary character has been identified to have its occurrence origin in the flow at the impeller inlet. The mechanism of the flow separation at the impeller inlet has been revealed with respect to the built-up of a flow dynamical barrier on the shroud side. It exactly explains the coincidence of the flow separation at the impeller inlet and that at the impeller outlet. To quantify the onset of the flow separation, a hypothesis is established based on the revealed mechanism. This has been satisfactorily validated by the test based on the flow visualization, pressure measurements and LDA applications. The method for stability control of the pump flows with effective suppression of the flow separation has also been presented.

2010-08-01

347

Rotating stall mechanism and stability control in the pump flows  

Energy Technology Data Exchange (ETDEWEB)

Investigations based on experimental measurements and flow dynamics analysis have been completed to reveal the mechanism of flow separations in the pump flow. The possible flow separation including the rotating stall in the vaned diffuser under the normal flow condition has been confirmed to be merely a diffuser effect and caused by the oversized expansion angle of the diffuser. The part load flow separation of both the stationary and the non-stationary character has been identified to have its occurrence origin in the flow at the impeller inlet. The mechanism of the flow separation at the impeller inlet has been revealed with respect to the built-up of a flow dynamical barrier on the shroud side. It exactly explains the coincidence of the flow separation at the impeller inlet and that at the impeller outlet. To quantify the onset of the flow separation, a hypothesis is established based on the revealed mechanism. This has been satisfactorily validated by the test based on the flow visualization, pressure measurements and LDA applications. The method for stability control of the pump flows with effective suppression of the flow separation has also been presented.

Zhang, Z, E-mail: zha@kwo.c [Oberhasli Hydroelectric Power Company (KWO) CH-3862 Innertkirchen Switzerland (Switzerland)

2010-08-15

348

Aging interferes central control mechanism for eccentric muscle contraction  

Directory of Open Access Journals (Sweden)

Full Text Available Previous studies report greater activation in the cortical motor network in controlling eccentric contraction (EC than concentric contraction (CC despite lower muscle activation level associated with EC vs. CC in healthy, young individuals. It is unknown, however, whether elderly people exhibiting increased difficulties in performing EC than CC possess this unique cortical control mechanism for EC movements. To address this question, we examined functional MRI (fMRI data acquired during EC and CC of the first dorsal interosseous (FDI muscle in 11 young (20-32 years and 9 old (67-73 years individuals. During the fMRI experiment, all subjects performed 20 CC and 20 EC of the right FDI with the same angular distance and velocity. The major findings from the behavioral and fMRI data analysis were that (1 movement stability was poorer in EC than CC in the old but not the young group; (2 similar to previous electrophysiological and fMRI reports, the EC resulted in significantly stronger activation in the motor control network consisting of primary, secondary and association motor cortices than CC in the young and old groups; (3 the biased stronger activation towards EC was significantly greater in the old than the young group especially in the secondary and association cortices such as supplementary and premotor motor areas and anterior cingulate cortex; and (4 in the primary motor and sensory cortices, the biased activation towards EC was significantly greater in the young than the old group. Greater activation in higher-order cortical fields for controlling EC movement by elderly adults may reflect activities in these regions to compensate for aging-related impairments in the ability to control complex EC movements. Our finding is useful for potentially guiding the development of targeted therapies to counteract age-related movement deficits and to prevent injury.

WanX.Yao

2014-05-01

349

Aging interferes central control mechanism for eccentric muscle contraction.  

Science.gov (United States)

Previous studies report greater activation in the cortical motor network in controlling eccentric contraction (EC) than concentric contraction (CC) despite lower muscle activation level associated with EC vs. CC in healthy, young individuals. It is unknown, however, whether elderly people exhibiting increased difficulties in performing EC than CC possess this unique cortical control mechanism for EC movements. To address this question, we examined functional magnetic resonance imaging (fMRI) data acquired during EC and CC of the first dorsal interosseous (FDI) muscle in 11 young (20-32 years) and 9 old (67-73 years) individuals. During the fMRI experiment, all subjects performed 20 CC and 20 EC of the right FDI with the same angular distance and velocity. The major findings from the behavioral and fMRI data analysis were that (1) movement stability was poorer in EC than CC in the old but not the young group; (2) similar to previous electrophysiological and fMRI reports, the EC resulted in significantly stronger activation in the motor control network consisting of primary, secondary and association motor cortices than CC in the young and old groups; (3) the biased stronger activation towards EC was significantly greater in the old than the young group especially in the secondary and association cortices such as supplementary and premotor motor areas and anterior cingulate cortex; and (4) in the primary motor and sensory cortices, the biased activation towards EC was significantly greater in the young than the old group. Greater activation in higher-order cortical fields for controlling EC movement by elderly adults may reflect activities in these regions to compensate for aging-related impairments in the ability to control complex EC movements. Our finding is useful for potentially guiding the development of targeted therapies to counteract age-related movement deficits and to prevent injury. PMID:24847261

Yao, Wan X; Li, Jinqi; Jiang, Zhiguo; Gao, Jia-Hong; Franklin, Crystal G; Huang, Yufei; Lancaster, Jack L; Yue, Guang H

2014-01-01

350

Aging interferes central control mechanism for eccentric muscle contraction  

Science.gov (United States)

Previous studies report greater activation in the cortical motor network in controlling eccentric contraction (EC) than concentric contraction (CC) despite lower muscle activation level associated with EC vs. CC in healthy, young individuals. It is unknown, however, whether elderly people exhibiting increased difficulties in performing EC than CC possess this unique cortical control mechanism for EC movements. To address this question, we examined functional magnetic resonance imaging (fMRI) data acquired during EC and CC of the first dorsal interosseous (FDI) muscle in 11 young (20–32 years) and 9 old (67–73 years) individuals. During the fMRI experiment, all subjects performed 20 CC and 20 EC of the right FDI with the same angular distance and velocity. The major findings from the behavioral and fMRI data analysis were that (1) movement stability was poorer in EC than CC in the old but not the young group; (2) similar to previous electrophysiological and fMRI reports, the EC resulted in significantly stronger activation in the motor control network consisting of primary, secondary and association motor cortices than CC in the young and old groups; (3) the biased stronger activation towards EC was significantly greater in the old than the young group especially in the secondary and association cortices such as supplementary and premotor motor areas and anterior cingulate cortex; and (4) in the primary motor and sensory cortices, the biased activation towards EC was significantly greater in the young than the old group. Greater activation in higher-order cortical fields for controlling EC movement by elderly adults may reflect activities in these regions to compensate for aging-related impairments in the ability to control complex EC movements. Our finding is useful for potentially guiding the development of targeted therapies to counteract age-related movement deficits and to prevent injury.

Yao, Wan X.; Li, Jinqi; Jiang, Zhiguo; Gao, Jia-Hong; Franklin, Crystal G.; Huang, Yufei; Lancaster, Jack L.; Yue, Guang H.

2014-01-01

351

Assessment of ventilatory neuromuscular drive in patients with obstructive sleep apnea  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The presence of abnormalities of the respiratory center in obstructive sleep apnea (OSA) patients and their correlation with polysomnographic data are still a matter of controversy. Moderately obese, sleep-deprived OSA patients presenting daytime hypersomnolence, with normocapnia and no clinical or [...] spirometric evidence of pulmonary disease, were selected. We assessed the ventilatory control and correlated it with polysomnographic data. Ventilatory neuromuscular drive was evaluated in these patients by measuring the ventilatory response (VE), the inspiratory occlusion pressure (P.1) and the ventilatory pattern (VT/TI, TI/TTOT) at rest and during submaximal exercise, breathing room air. These analyses were also performed after inhalation of a hypercapnic mixture of CO2 (DP.1/DPETCO2, DVE/DPETCO2). Average rest and exercise ventilatory response (VE: 12.2 and 32.6 l/min, respectively), inspiratory occlusion pressure (P.1: 1.5 and 4.7 cmH2O, respectively), and ventilatory pattern (VT/TI: 0.42 and 1.09 l/s; TI/TTOT: 0.47 and 0.46 l/s, respectively) were within the normal range. In response to hypercapnia, the values of ventilatory response (DVE/DPETCO2: 1.51 l min-1 mmHg-1) and inspiratory occlusion pressure (DP.1/DPETCO2: 0.22 cmH2O) were normal or slightly reduced in the normocapnic OSA patients. No association or correlation between ventilatory neuromuscular drive and ventilatory pattern, hypersomnolence score and polysomnographic data was found; however a significant positive correlation was observed between P.1 and weight. Our results indicate the existence of a group of normocapnic OSA patients who have a normal awake neuromuscular ventilatory drive at rest or during exercise that is partially influenced by obesity

L.R.A., Bittencourt; S.M.T., Moura; M.C., Bagnato; L.C., Gregório; S., Tufik; L.E., Nery.

352

Assessment of ventilatory neuromuscular drive in patients with obstructive sleep apnea  

Directory of Open Access Journals (Sweden)

Full Text Available The presence of abnormalities of the respiratory center in obstructive sleep apnea (OSA patients and their correlation with polysomnographic data are still a matter of controversy. Moderately obese, sleep-deprived OSA patients presenting daytime hypersomnolence, with normocapnia and no clinical or spirometric evidence of pulmonary disease, were selected. We assessed the ventilatory control and correlated it with polysomnographic data. Ventilatory neuromuscular drive was evaluated in these patients by measuring the ventilatory response (VE, the inspiratory occlusion pressure (P.1 and the ventilatory pattern (VT/TI, TI/TTOT at rest and during submaximal exercise, breathing room air. These analyses were also performed after inhalation of a hypercapnic mixture of CO2 (DP.1/DPETCO2, DVE/DPETCO2. Average rest and exercise ventilatory response (VE: 12.2 and 32.6 l/min, respectively, inspiratory occlusion pressure (P.1: 1.5 and 4.7 cmH2O, respectively, and ventilatory pattern (VT/TI: 0.42 and 1.09 l/s; TI/TTOT: 0.47 and 0.46 l/s, respectively were within the normal range. In response to hypercapnia, the values of ventilatory response (DVE/DPETCO2: 1.51 l min-1 mmHg-1 and inspiratory occlusion pressure (DP.1/DPETCO2: 0.22 cmH2O were normal or slightly reduced in the normocapnic OSA patients. No association or correlation between ventilatory neuromuscular drive and ventilatory pattern, hypersomnolence score and polysomnographic data was found; however a significant positive correlation was observed between P.1 and weight. Our results indicate the existence of a group of normocapnic OSA patients who have a normal awake neuromuscular ventilatory drive at rest or during exercise that is partially influenced by obesity

Bittencourt L.R.A.

1998-01-01

353

A geometric study of abnormality in optimal control problems for control and mechanical control systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Durante los últimos cuarenta años la geometría diferencial ha sido una herramienta para entender la teoría de control óptimo. Habitualmente la mejor estrategia para resolver un problema es transformarlo en otro problema que sea más tratable. El Principio del Máximo de Pontryagin dota al problema de control óptimo de una estructura Hamiltoniana.

2008-01-01

354

Chemo-mechanical control of neural stem cell differentiation  

Science.gov (United States)

Cellular processes such as adhesion, proliferation, and differentiation are controlled in part by cell interactions with the microenvironment. Cells can sense and respond to a variety of stimuli, including soluble and insoluble factors (such as proteins and small molecules) and externally applied mechanical stresses. Mechanical properties of the environment, such as substrate stiffness, have also been suggested to play an important role in cell processes. The roles of both biochemical and mechanical signaling in fate modification of stem cells have been explored independently. However, very few studies have been performed to study well-controlled chemo-mechanotransduction. The objective of this work is to design, synthesize, and characterize a chemo-mechanical substrate to encourage neuronal differentiation of C17.2 neural stem cells. In Chapter 2, Polyacrylamide (PA) gels of varying stiffnesses are functionalized with differing amounts of whole collagen to investigate the role of protein concentration in combination with substrate stiffness. As expected, neurons on the softest substrate were more in number and neuronal morphology than those on stiffer substrates. Neurons appeared locally aligned with an expansive network of neurites. Additional experiments would allow for statistical analysis to determine if and how collagen density impacts C17.2 differentiation in combination with substrate stiffness. Due to difficulties associated with whole protein approaches, a similar platform was developed using mixed adhesive peptides, derived from fibronectin and laminin, and is presented in Chapter 3. The matrix elasticity and peptide concentration can be individually modulated to systematically probe the effects of chemo-mechanical signaling on differentiation of C17.2 cells. Polyacrylamide gel stiffness was confirmed using rheological techniques and found to support values published by Yeung et al. [1]. Cellular growth and differentiation were assessed by cell counts, immunocytochemistry (ICC), and neurite measurements. Data indicates that chemo-mechanical signaling is highly combinatorial in directing differentiation of C17.2s along a neuronal lineage in vitro. Chapter 4 discusses the design, synthesis, and characterization of a novel nanomaterial platform to investigate ligand-receptor binding. PEGylated nanoparticles were successfully synthesized and found to be relatively homogenous in size and morphology, as observed by transmission electron microscopy. However, successful binding of RGD peptide to the nanoparticle was not confirmed. Finally, a method for proteomic analysis of the C17.2 secretome is discussed in Chapter 5. Secreted proteins are of great importance as they can both influence cell behaviors as well as act as biomarkers of differentiation. Methods have been selected and optimized for protein extraction and two dimensional gel electrophoresis to be followed by mass spectrometry and protein identification. A temporal analysis of unique proteins expressed by C17.2s will result in a differentiation timeline. Deducing the dynamics of neuronal cell secretions will greatly contribute to the characterization of the C17.2 cell line and improve its relevance as a neural stem cell model. Overall, results illustrate the importance of chemical and mechanical cues in manipulating neural stem cell fate. These material platforms in combination with the further characterization of the C17.2 neural stem cells could have a great impact in the fields of neuronal biology, translational therapeutics, and pharmaceutical research.

Geishecker, Emily R.

355

Neuromuscular Activity of Micrurus laticollaris (Squamata: Elapidae Venom in Vitro  

Directory of Open Access Journals (Sweden)

Full Text Available In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake venom (MLV in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1–30 µg/mL neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.05. In mouse phrenic nerve-diaphragm preparations, MLV (1–10 µg/mL promoted a slight increase in the amplitude of twitch-tension (3 µg/mL, followed by neuromuscular blockade (n = 4; the highest concentration caused complete inhibition of the twitches (time for 50% blockade = 26 ± 3 min, without exhibiting a previous neuromuscular facilitation. The venom (3 µg/mL induced a biphasic modulation in the frequency of miniature end-plate potentials (MEPPs/min, causing a significant increase after 15 min, followed by a decrease after 60 min (from 17 ± 1.4 (basal to 28 ± 2.5 (t15 and 12 ± 2 (t60. The membrane resting potential of mouse diaphragm preparations pre-exposed or not to d-tubocurarine (5 µg/mL was also significantly less negative with MLV (10 µg/mL. Together, these results indicate that M. laticollaris venom induces neuromuscular blockade by a combination of pre- and post-synaptic activities.

Alejandro Carbajal-Saucedo

2014-01-01

356

Sleep polygraphic parameters in neuromuscular diseases / Parâmetros poligráficos do sono em doenças neuromusculares  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Estudando 32 pacientes com doenças neuromusculares -22 com forma de distrofia muscular, 3 com forma de miopatia congênita, 4 com forma de atrofia muscular espinal, 1 com forma recorrente de polimiosite e 1 com síndrome de osteogenesis imperfecta - dos quais 21 estavam impossibilitados de deambulação [...] , distúrbios respiratórios relacionados ao sono foram observados sob forma dessaturação da oxi-hemogloblina, arritmia cardíaca, taquipnéia, taquicardia e roncos. Nove desses 32 pacientes apresentaram períodos de dessaturação de oxi-hemoglobina maiores que 4% em relação aos níveis obtidos em vigília e repouso. Esse grupo de pacientes era caracterizado por apresentar síndrome respiratória restritiva associada a deformidade torácica (principalmente escoliose). Alguns apresentaram taquipnéia e/ou saturação da oxi-hemoglobina abaixo de 90% durante o repouso e em vigília. Neste grupo, roncos foram observados principalmente nos pacientes com forma de distrofia muscular, enquanto a taquipnéia foi observada sobretudo nos pacientes com os maiores níveis de dessaturação. A quantificação do sono mostrou aumento na porcentagem do estado 1 do sono associada a diminuição ou mesmo ausência do estado do sono paradoxal. Isso nos leva a crer em um provável mecanismo de proteção consequente à potencialização da hipoventilação observada durante o estado de sono paradoxal, em que os maiores níveis de dessaturação são observados. Abstract in english In a polysomnography study of 32 neuromuscular patients - 22 with a form of muscular dystrophy, 3 with a form of congenital myopathy, 4 with a form of spinal muscular atrophy, 1 with a recurrent form of polymyositis and 1 with osteogenesis imperfecta syndrome - of which 21 were nonambulatory, we obs [...] erved sleep related respiratory disturbances represented by: drops in oxygen saturation (SaO2), cardiac arrythmia, sleep disruption, apneas, tachypnea, tachycardia and snoring. Nine out of the cohort of 32 patients presented with significant desaturations periods. These patients presented with an associated restrictive syndrome and thoracic deformities, some with tachypnea and/or SaO2 below 90% during wakefulness. In this group, snoring was observed in those patients with a form of muscular dystrophy while tachypnea was observed in patients who presented the highest desaturations levels. Sleep quantification revealed an increase of stage 1 sleep coupled with a decrease or even total absence of REM sleep. This is, we believe, a likely consequence of episodic desaturations that may accompany sleep hypoventilation which is potentialised during REM sleep stage.

Pradella, Márcia.

357

Communication: Quantum Zeno-based control mechanism for molecular fragmentation  

Science.gov (United States)

A quantum control mechanism is proposed for molecular fragmentation processes within a scenario grounded on the quantum Zeno effect. In particular, we focus on the van der Waals Ne-Br2 complex, which displays two competing dissociation channels via vibrational and electronic predissociation. Accordingly, realistic three-dimensional wave packet simulations are carried out by using ab initio interaction potentials recently obtained to reproduce available experimental data. Two numerical models to simulate the repeated measurements are reported and analyzed. It is found that the otherwise fast vibrational predissociation is slowed down in favor of the slow electronic (double fragmentation) predissociation, which is enhanced by several orders of magnitude. Based on these theoretical predictions, some hints to experimentalists to confirm their validity are also proposed.

Sanz-Sanz, C.; Sanz, A. S.; González-Lezana, T.; Roncero, O.; Miret-Artés, S.

2012-03-01

358

Mechanical control of a microrod-resonator optical frequency comb  

CERN Document Server

Robust control and stabilization of optical frequency combs enables an extraordinary range of scientific and technological applications, including frequency metrology at extreme levels of precision, novel spectroscopy of quantum gases and of molecules from visible wavelengths to the far infrared, searches for exoplanets, and photonic waveform synthesis. Here we report on the stabilization of a microresonator-based optical comb (microcomb) by way of mechanical actuation. This represents an important step in the development of microcomb technology, which offers a pathway toward fully-integrated comb systems. Residual fluctuations of our 32.6 GHz microcomb line spacing reach a record stability level of $5\\times10^{-15}$ for 1 s averaging, thereby highlighting the potential of microcombs to support modern optical frequency standards. Furthermore, measurements of the line spacing with respect to an independent frequency reference reveal the effective stabilization of different spectral slices of the comb with a $&...

Papp, Scott B; Diddams, Scott A

2012-01-01

359

Bacterial cell curvature through mechanical control of cell growth  

DEFF Research Database (Denmark)

The cytoskeleton is a key regulator of cell morphogenesis. Crescentin, a bacterial intermediate filament-like protein, is required for the curved shape of Caulobacter crescentus and localizes to the inner cell curvature. Here, we show that crescentin forms a single filamentous structure that collapses into a helix when detached from the cell membrane, suggesting that it is normally maintained in a stretched configuration. Crescentin causes an elongation rate gradient around the circumference of the sidewall, creating a longitudinal cell length differential and hence curvature. Such curvature can be produced by physical force alone when cells are grown in circular microchambers. Production of crescentin in Escherichia coli is sufficient to generate cell curvature. Our data argue for a model in which physical strain borne by the crescentin structure anisotropically alters the kinetics of cell wall insertion to produce curved growth. Our study suggests that bacteria may use the cytoskeleton for mechanical control of growth to alter morphology

Cabeen, M.; Charbon, Godefroid

2009-01-01

360

A comparison of drive mechanisms for precision motion controlled stages  

Energy Technology Data Exchange (ETDEWEB)

This abstract presents a comparison of two drive mechanisms, a Rohlix{reg_sign} drive and a polymer nut drive, for precision motion controlled stages. A single-axis long-range stage with a 50 mm traverse combined with a short-range stage with a 16 {micro}m traverse at a operational bandwidth of 2.2 kHz were developed to evaluate the performance of the drives. The polymer nut and Rohlix{reg_sign} drives showed 4 nm RMS and 7 nm RMS positioning capabilities respectively, with traverses of 5 mm at a maximum velocity of 0.15 mm{sup -}s{sup -1} with the short range stage operating at a 2.2 kHz bandwidth. Further results will be presented in the subsequent sections.

Buice, E S; Yang, H; Otten, D; Smith, S T; Hocken, R J; Trumper, D L; Seugling, R M

2006-03-22

 
 
 
 
361

14 CFR 29.923 - Rotor drive system and control mechanism tests.  

Science.gov (United States)

...2009-01-01 2009-01-01 false Rotor drive system and control mechanism tests. 29.923...TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.923 Rotor drive system and control mechanism tests. (a)...

2009-01-01

362

14 CFR 27.923 - Rotor drive system and control mechanism tests.  

Science.gov (United States)

...2009-01-01 2009-01-01 false Rotor drive system and control mechanism tests. 27.923...NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.923 Rotor drive system and control mechanism tests....

2009-01-01

363

Closed-loop timing controller design for control rod drive mechanism (CRDM) control system in pressurized water reactor  

International Nuclear Information System (INIS)

The method that the operating condition of Control Rod Drive Mechanism (CRDM) can be monitored without mounting sensors within CRDM housing was developed, and by using this developed method the closed-loop controller for the CRDM was designed which can optimize the performance and maximize the reliability of CRDM operation. Neural network is utilized as pattern recognition engine in detecting CRDM actuation. In this paper, most problems in previous open loop system are resolved. The control algorithms for closed-loop system were developed and implemented within the hardware of timing controller based on microprocessor. All functions in the timing controller were verified by means of real time CRDM simulator. The results show that the timing controller performs its intended functions properly. (author)

1997-04-01