scholarly journals Functional state of motor units of skeletal muscles in chronic diseases of motoneurons and their axones

1995 ◽  
Vol XXVII (1-2) ◽  
pp. 5-10
Author(s):  
L. F. Kasatkina
Keyword(s):  
Motor Neuron ◽  
Chronic Diseases ◽  
Functional State ◽  
Skeletal Muscles ◽  
Neuromuscular Diseases ◽  
Motor Units ◽  
Peripheral Motor ◽  
Partial Compensation

Electromyographic examination of the potentials of motor units in 498 patients with different forms of peripheral motor neuron pathology allowed to distinguish electromyographic criteria of estimation of the denervationreinnervation processes. Determination of phases of full, partial compensation and of decompensation phase may be used for examination of pathogenesis of neuromuscular diseases, their diagnosis and assessment of their progress.

Relative Refractoriness and Patterned Discharge of Locust Flight Motor Neurons

1964 ◽  
Vol 41 (1) ◽  
pp. 191-205
Author(s):  
DONALD M. WILSON
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Functional Significance ◽  
Motor Units ◽  
Frequency Division ◽  
Electronic Model ◽  
Antidromic Stimulation ◽  
Flight Muscles ◽  
Peripheral Motor ◽  
Flight Motor

1. The threshold recovery after impulse propagation in locust peripheral motor axons to flight muscles is described. The refractoriness is large enough to have functional significance for at least 10 msec, and may be detected after 50-100 msec. The refractoriness to successive impulses accumulates. 2. Ganglionic and axonal preparations demonstrate frequency division, apparently due to the refractoriness of the motor neuron. Accumulating refractoriness gives rise to non-integral division. Behaviour of the locust preparations is compared to that of an electronic model. 3. Antidromic stimulation during flight shows that refractory oscillation may regulate the interval between the closer spaced pairs of impulses in the motor units during flight, but that the wingbeat cycle must have another cause.

scholarly journals Bioengineered model of the human motor unit with physiologically functional neuromuscular junctions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rowan P. Rimington ◽  
Jacob W. Fleming ◽  
Andrew J. Capel ◽  
Patrick C. Wheeler ◽  
Mark P. Lewis
Keyword(s):  
Neuromuscular Junction ◽  
Motor Neuron ◽  
Motor Unit ◽  
Motor Nerve ◽  
Motor Units ◽  
Extracellular Matrices ◽  
Synaptic Membrane ◽  
Type I ◽  
Dependent Manner ◽  
Human Motor

AbstractInvestigations of the human neuromuscular junction (NMJ) have predominately utilised experimental animals, model organisms, or monolayer cell cultures that fail to represent the physiological complexity of the synapse. Consequently, there remains a paucity of data regarding the development of the human NMJ and a lack of systems that enable investigation of the motor unit. This work addresses this need, providing the methodologies to bioengineer 3D models of the human motor unit. Spheroid culture of iPSC derived motor neuron progenitors augmented the transcription of OLIG2, ISLET1 and SMI32 motor neuron mRNAs ~ 400, ~ 150 and ~ 200-fold respectively compared to monolayer equivalents. Axon projections of adhered spheroids exceeded 1000 μm in monolayer, with transcription of SMI32 and VACHT mRNAs further enhanced by addition to 3D extracellular matrices in a type I collagen concentration dependent manner. Bioengineered skeletal muscles produced functional tetanic and twitch profiles, demonstrated increased acetylcholine receptor (AChR) clustering and transcription of MUSK and LRP4 mRNAs, indicating enhanced organisation of the post-synaptic membrane. The number of motor neuron spheroids, or motor pool, required to functionally innervate 3D muscle tissues was then determined, generating functional human NMJs that evidence pre- and post-synaptic membrane and motor nerve axon co-localisation. Spontaneous firing was significantly elevated in 3D motor units, confirmed to be driven by the motor nerve via antagonistic inhibition of the AChR. Functional analysis outlined decreased time to peak twitch and half relaxation times, indicating enhanced physiology of excitation contraction coupling in innervated motor units. Our findings provide the methods to maximise the maturity of both iPSC motor neurons and primary human skeletal muscle, utilising cell type specific extracellular matrices and developmental timelines to bioengineer the human motor unit for the study of neuromuscular junction physiology.

Level of thyroid-stimulating hormone as basic diagnostic marker and criterion of treatment success of thyroid diseases

2017 ◽  
pp. 102-106
Author(s):  
V.I. Pankiv ◽  
Keyword(s):  
Key Words ◽  
Functional State ◽  
Diagnostic Marker ◽  
Treatment Success ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Diseases ◽  
Early Diagnostics ◽  
Basic Test ◽  
Stimulating Hormone

In the article information is generalized on the aspects of early diagnostics of thyrois disorders. The value of thyroid-stimulating hormone is underlined as basic test for determination of the thyroid functional state and criterion of treatment success of thyroid diseases. Key words: thyroid, thyroid-stimulating hormone, diagnostics.

Determination of the probability of aggregation to assess the functional state of platelets

1981 ◽  
Vol 91 (4) ◽  
pp. 555-558
Author(s):  
R. A. Markosyan ◽  
Z. A. Gabbasov ◽  
A. Yu. Radin ◽  
E. G. Popov
Keyword(s):  
Functional State

scholarly journals Post-synaptic morphology of mouse neuromuscular junctions is linked to muscle fibre type

2020 ◽  
Author(s):  
Aleksandra M. Mech ◽  
Anna-Leigh Brown ◽  
Giampietro Schiavo ◽  
James N. Sleigh
Keyword(s):  
Motor Neuron ◽  
Muscle Fibre ◽  
Fibre Type ◽  
Neuromuscular Junctions ◽  
Fibre Diameter ◽  
Neuromuscular Diseases ◽  
Neuronal Morphology ◽  
Muscle Fibre Type ◽  
Muscle Membrane ◽  
Muscle Fibres

AbstractThe neuromuscular junction (NMJ) is the highly specialised peripheral synapse formed between lower motor neuron terminals and muscle fibres. Post-synaptic acetylcholine receptors (AChRs), which are found in high density in the muscle membrane, bind to acetylcholine released into the synaptic cleft of the NMJ, ultimately facilitating the conversion of motor action potentials to muscle contractions. NMJs have been studied for many years as a general model for synapse formation, development and function, and are known to be early sites of pathological changes in many neuromuscular diseases. However, information is limited on the diversity of NMJs in different muscles, whether muscle fibre type impacts NMJ morphology and growth, and the relevance of these parameters to neuropathology. Here, this crucial gap was addressed using a robust and standardised semi-automated workflow called NMJ-morph to quantify features of pre- and post-synaptic NMJ architecture in an unbiased manner. Five wholemount muscles from wild-type mice were dissected and compared at immature (post-natal day, P7) and early adult (P31-32) timepoints. Post-synaptic AChR morphology was found to be more variable between muscles than that of the motor neuron terminal and there were greater differences in the developing NMJ than at the mature synapse. Post-synaptic architecture, but not neuronal morphology or post-natal synapse growth, correlates with fibre type and is largely independent of muscle fibre diameter. Counter to previous observations, this study indicates that smaller NMJs tend to innervate muscles with higher proportions of fast twitch fibres and that NMJ growth rate is not conserved across all muscles. Furthermore, healthy pre- and post-synaptic NMJ morphological parameters were collected for five anatomically and functionally distinct mouse muscles, generating reference data that will be useful for the future assessment of neuromuscular disease models.Graphical Abstract

scholarly journals THE IMPORTANCE OF THE FUNCTIONAL STATE OF THIOL-DISULFIDE UNIT OF THE ANTIOXIDANT SYSTEM IN THE ACUTE BACTERIAL DYSENTERY IN THE FORECAST OF THE COURSE AND THE SELECTION OF THE TREATMENT REGIMEN

2017 ◽  
Vol 22 (5) ◽  
pp. 258-263
Author(s):  
Zarema G. Tagirova
Keyword(s):  
Antimicrobial Peptides ◽  
Functional State ◽  
Antioxidant System ◽  
Disulfide Bonds ◽  
Severe Disease ◽  
Treatment Methods ◽  
Sh Groups ◽  
Group I ◽  
Antioxidant Agents

The goal was to optimize the treatment of shigellosis patients on the basis of an evaluation of the functional state of the thiol-disulfide unit of the antioxidant system (AOS) on a background of various treatment methods. Materials and methods. 400 patients with acute bacterial dysentery of varying severity of the course were observed; Shigella Flexner was isolated in 324(81%) cases, Shigella Sonne - in 76(19%) cases. The determination of sulfhydryl (SH-) groups and disulfide bonds (SS-) was carried out by the direct and reverse amperometric titration with the use of silver nitrate and unithiol in hemolysate. Three groups separated by random sampling were considered. In group I (122 patients), basic therapy was prescribed, including etiotropic and pathogenetic treatment. In group II (134 patients), pathogenetic treatment was prescribed in the combination with a complex of natural cytokines and antimicrobial peptides secreted by pig peripheral blood leukocytesa (»superlimph» preparation). In the third group (144 patients), the drug «superlimph» was prescribed along with etiotropic and pathogenetic treatment. Results. In acute bacterial dysentery disturbances of the redox balance were established to be correlated with the severity of the course in the form of a significant decrease in the level of SH-groups and the thiol-disulfide coefficient on the background of an increase in the level of SS-groups, which indicates to a decrease in the buffer capacity of the AOS. These data can serve as predictors of the nature of the course of dysentery. Comparative clinical evaluation of the effectiveness of various treatment methods revealed the most pronounced in severe disease advantages of complex therapy, including a combination of basic etiotropic, pathogenetic treatment with a complex of natural cytokines and antimicrobial peptides («superlimph»). Conclusion. The change in the ratio of oxidative processes to AOS occurs at any severity of dysentery, but in severe cases these changes acquire a qualitative character. In the survey standards for bacterial dysentery there is recommended to include the determination of indices of the thiol-disulfide unit, as an additional criterion for the severity of the course and the prognosis of the course of the disease. Exceeding the concentration of SS-groups of the concentration of SH-groups and the inversion of the thiol-disulfide coefficient as markers of the breakdown in AOS seem to be prognostically unfavorable factor. The severe course of acute bacterial dysentery is an indication for inclusion of antioxidant agents in the therapeutic complex. Based on the mechanism of revealed abnormalities in AOS, the use of a complex of natural cytokines and antimicrobial peptides («superlimph») can be considered as an immunocorrecting drug.

Adaptation of the ASTRIN staining technique for quantitative determination of the functional state of the cellular nucleus

1987 ◽  
Vol 81 (1) ◽  
pp. 95-IN2 ◽  
Author(s):  
Péter Kovács ◽  
György Csaba ◽  
László Kőhidai ◽  
Ottilie Török
Keyword(s):  
Quantitative Determination ◽  
Functional State ◽  
Staining Technique

Anatomo-functional state of organs of small tangs in poor responders

2018 ◽  
pp. 50-54
Author(s):  
G.V. Strelko ◽  
Keyword(s):  
Blood Flow ◽  
Functional Status ◽  
Vascular Resistance ◽  
Functional State ◽  
Color Doppler ◽  
Ovarian Response ◽  
Treatment Programs ◽  
Poor Responders ◽  
Surgical Interventions

The objective: study of the anatomical and functional status of the uterus and ovaries in poor responders in ART programs. Materials and methods. Determination of the anatomical features and functional status of the uterus and ovaries in «poor responders» to exclude a clinically significant pathology that would affect the success of the ART program was performed by ultrasound scanning with the study of topografts, sizes, contours, echostructure of the uterus and ovary and determination of the volume of the ovaries and the number of antral follicles. Blood flow in the vessels of the stroma of the ovaries, as one of the important criteria for assessing the possible ovarian response, was assessed using color Doppler mapping. Results. «Poor responders» patients have a smaller sise of ovaries and a reduced number of antral folicles, which can be explained by the surgical interventions carried out according to the type of ovarian resection and the cysts removal. In addition, during the transition from the follicular to luteal phase, there is no decrease in the vascular resistance of the dominant follicle, which slows the process of ovulation and reduces the likelihood of fertilization in conditions of increased vascular resistance. Conclusion. Ultrasound examination of the uterus and ovaries and doplerometric investigation of peryfollicular blood flow allows us to thoroughly approach both the evaluation of the ovarian response and the endometric readiness for implantation, which dictates the need for an individual selection of preconceptional preparation and treatment programs for ART. Key words: anatomical and functional state, pelvic organs, ovarian reserve, peryfollicular blood flow, poor responders.

scholarly journals Assessing Rat Forelimb and Hindlimb Motor Unit Connectivity as Objective and Robust Biomarkers of Spinal Motor Neuron Function

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Markus E. Harrigan ◽  
Angela R. Filous ◽  
Andrew P. Tosolini ◽  
Renee Morris ◽  
Jan M. Schwab ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Motor Unit ◽  
Compound Muscle Action Potential ◽  
Motor Units ◽  
Longitudinal Assessment ◽  
Muscle Contractility ◽  
Cross Sectional ◽  
Muscle Action Potential ◽  
Experimental Findings ◽  
Neuron Function

Abstract Sensitive and objective biomarkers of neuronal injury, degeneration, and regeneration can help facilitate translation of experimental findings into clinical testing. Whereas measures of upper motor neuron connectivity have been readily established, functional assessments of lower motor neuron (LMN) innervation of forelimb muscles are lacking. Compound muscle action potential (CMAP) and motor unit (MU) number estimation (MUNE) are well-established methods that allow longitudinal MU integrity monitoring in patients. In analogy we refined CMAP and MUNE methods for assessing spinal MU input in the rat forelimb and hindlimb. Repeated CMAP and MUNE recordings are robust (coefficients of variability: 4.5–11.3%), and MUNE measurements from forelimb wrist flexor muscles (415 ± 8 [SEM]) align with back-traced anatomical LMN counts (336 ± 16 [SEM]). For disease validation, cross-sectional blinded electrophysiological and muscle contractility measurements were obtained in a cohort of G93A SOD1 mutant overexpressing rats and compared with controls. Longitudinal assessment of mutant animals demonstrated progressive motor unit decline in the hindlimb to a greater extent than the forelimb. Hindlimb CMAP and MUNE demonstrated strong correlations with plantarflexion muscle contractility. Cross-species assessment of upper/fore- limb and lower/hind- limb motor units using objective electrophysiological CMAP and MUNE values as biomarkers will guide and improve bi-directional translation.

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