Accuracy of Force Repeatability in Relation to its Value and the Subjects’ Sex

AbstractThe purpose of the study was to determine the influence of force value and sex on force generation repeatability.The total of 17 female and 24 male students performed 3 maximal voluntary contractions for maximal force (FThe force generation repeatability rose with the increase of triggered force in both sexes; between force target 49 N vs. 98 N and 147 N (The influence of force value and a minor influence of sex on accuracy in generated forces might suggest that the control of muscle force by the central nervous system is similar in both sexes and the sex differences in muscle force generations are rather of muscle mass and structure.

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Cerebrospinal fluid ceftazidime kinetics in patients with external ventriculostomies.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.3.763 ◽

1996 ◽

Vol 40 (3) ◽

pp. 763-766 ◽

Cited By ~ 18

Author(s):

R Nau ◽

H W Prange ◽

M Kinzig ◽

A Frank ◽

A Dressel ◽

...

Keyword(s):

Central Nervous System ◽

Cerebrospinal Fluid ◽

Nervous System ◽

High Performance ◽

Elimination Half ◽

Daily Dose ◽

Order Of Magnitude ◽

The Central Nervous System ◽

Occlusive Hydrocephalus ◽

A Minor

Ceftazidime has proven to be effective for the treatment of bacterial meningitis caused by multiresistant gram-negative bacteria. Since nosocomial central nervous system infections are often accompanied by only a minor dysfunction of the blood-cerebrospinal fluid (CSF) barrier, patients with noninflammatory occlusive hydrocephalus who had undergone external ventriculostomy were studied (n = 8). Serum and CSF were drawn repeatedly after the administration of the first dose of ceftazidime (3 g over 30 min intravenously), and concentrations were determined by high-performance liquid chromatography by using UV detection. The concentrations of ceftazidime in CSF were maximal at 1 to 13 h (median, 5.5 h) after the end of the infusion and ranged from 0.73 to 2.80 mg/liter (median, 1.56 mg/liter). The elimination half-lives were 3.13 to 18.1 h (median, 10.7 h) in CSF compared with 2.02 to 5.24 h (median, 3.74 h) in serum. The ratios of the areas under the concentration-time curves in CSF and serum (AUCCSF/AUCS) ranged from 0.027 to 0.123 (median, 0.054). After the administration of a single dose of 3 g, the maximum concentrations of ceftazidime in CSF were approximately four times higher than those after the administration of 2-g intravenous doses of cefotaxime (median, 0.44 mg/liter) and ceftriaxone (median, 0.43 mg/liter) (R. Nau, H. W. Prange, P. Muth, G. Mahr, S. Menck, H. Kolenda, and F. Sörgel, Antimicrob. Agents Chemother. 37:1518-1524, 1993). The median AUCCSF/AUCS ratio of ceftazidime was slightly below that of cefotaxime (0.12), but it was 1 order of magnitude above the median AUCCSF/AUCS of ceftriaxone (0.007) (Nau et al., Antimicrob. Agents Chemother. 37:1518-1524, 1993). The concentrations of ceftazidime observed in CSF were above the MICs for most Pseudomonas aeruginosa strains. However, they are probably not high enough to be rapidly bactericidal. For this reason, the daily dose should be increased to 12 g in cases of P. aeruginosa infections of the central nervous system when the blood-CSF barrier is minimally impaired.

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Cleidocranial Dysplasia with Neonatal Death Due to Central Nervous System Injury in Utero: Case Report and Literature Review

Pediatric and Developmental Pathology ◽

10.1007/s100249900045 ◽

1998 ◽

Vol 1 (4) ◽

pp. 314-318 ◽

Cited By ~ 9

Author(s):

Calvin E. Oyer ◽

Nina G. Tatevosyants ◽

Selina C. Cortez ◽

Abby Hornstein ◽

Michael Wallach

Keyword(s):

Central Nervous System ◽

Nervous System ◽

In Utero ◽

Cleidocranial Dysplasia ◽

Related Condition ◽

Wormian Bones ◽

Bilateral Absence ◽

The Central Nervous System ◽

The Right ◽

A Minor

Cleidocranial dysplasia (CCD), an uncommon disorder involving membranous bones, is rarely lethal in early life. The calvaria is defective and wormian bones are present. Abnormalities of the clavicles vary in severity from a minor unilateral defect to bilateral absence. This report concerns pre- and postmortem anatomical and radiological findings in a 15-day-old female neonate with CCD. Her postnatal course was characterized by seizures and recognition of hydrocephalus during the first day of life. The calvaria was hypoplastic with numerous wormian bones. A pseudofracture of the right clavicle was present. Hydrocephalus was present in the brachycephalic brain which had a severely thinned cerebral cortex. Hemosiderin in the ventricular lining and marked subependymal gliosis were interpreted as evidence of old intraventricular hemorrhage that had occurred in utero. A CCD-related condition, Yunis-Varon syndrome (YVS), is noted for early lethality and for developmental and secondary abnormalities of the central nervous system. The present case only partially matches the phenotype of YVS and might represent a part of a spectrum of phenotypic variants ranging from viable CCD to lethal YVS.

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Sex differences in the central nervous system

Endeavour ◽

10.1016/0160-9327(87)90205-5 ◽

1987 ◽

Vol 11 (3) ◽

pp. 156-159 ◽

Cited By ~ 2

Author(s):

J.J. van der Werff ten Bosch ◽

P. van der Schoot

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Sex Differences ◽

The Central Nervous System

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The 13th J. A. F. Stevenson Memorial Lecture Sexual differentiation of the brain: possible mechanisms and implications

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y85-098 ◽

1985 ◽

Vol 63 (6) ◽

pp. 577-594 ◽

Cited By ~ 65

Author(s):

Roger A. Gorski

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Sex Differences ◽

Sexual Differentiation ◽

Gonadal Hormones ◽

Model Systems ◽

Memorial Lecture ◽

Actual Structure ◽

The Central Nervous System ◽

The Brain

The mammalian brain appears to be inherently feminine and the action of testicular hormones during development is necessary for the differentiation of the masculine brain both in terms of functional potential and actual structure. Experimental evidence for this statement is reviewed in this discussion. Recent discoveries of marked structural sex differences in the central nervous system, such as the sexually dimorphic nucleus of the preoptic area in the rat, offer model systems to investigate potential mechanisms by which gonadal hormones permanently modify neuronal differentiation. Although effects of these steroids on neurogenesis and neuronal migration and specification have not been conclusively eliminated, it is currently believed, but not proven, that the principle mechanism of steroid action is to maintain neuronal survival during a period of neuronal death. The structural models of the sexual differentiation of the central nervous system also provide the opportunity to identify sex differences in neurochemical distribution. Two examples in the rat brain are presented: the distribution of serotonin-immunoreactive fibers in the medial preoptic nucleus and of tyrosine hydroxylase-immunoreactive fibers and cells in the anteroventral periventricular nucleus. It is likely that sexual dimorphisms will be found to be characteristic of many neural and neurochemical systems. The final section of this review raises the possibility that the brain of the adult may, in response to steroid action, be morphologically plastic, and considers briefly the likelihood that the brain of the human species is also influenced during development by the hormonal environment.

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Adaptation after vastus lateralis denervation in rats suggests neural regulation of joint stresses and strains

10.1101/312488 ◽

2018 ◽

Cited By ~ 1

Author(s):

Cristiano Alessando ◽

Benjamin A. Rellinger ◽

Filipe O. Barroso ◽

Matthew C. Tresch

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Task Performance ◽

Neural Control ◽

Muscle Force ◽

Vastus Lateralis ◽

Adaptation Strategies ◽

Internal Joint ◽

The Central Nervous System ◽

Muscle Activations

AbstractIn order to produce movements, muscles must act through joints. The translation from muscle force to limb movement is mediated by internal joint structures that permit movement in some directions but constrain it in others. Although muscle forces acting against constrained directions will not affect limb movements, such forces can cause excess stresses and strains in joint structures, leading to pain or injury. In this study, we hypothesized that the central nervous system (CNS) chooses muscle activations to avoid excess joint stresses and strains. We evaluated this hypothesis by examining adaptation strategies after selective paralysis of a muscle acting at the rat knee. We show that the CNS compromises between restoration of task performance and regulation of joint stresses and strains. These results have significant implications to our understanding of the neural control of movements, suggesting that common theories emphasizing task performance are insufficient to explain muscle activations during behaviors.

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Kidney and Ureteral Disease during HIV Infection

Urologia Journal ◽

10.1177/039156039205900211 ◽

1992 ◽

Vol 59 (2) ◽

pp. 46-49

Author(s):

R. Musci ◽

T. Meroni ◽

M. Andres ◽

O. De Cobelli ◽

P. Larcher ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Hiv Infection ◽

Acquired Immunodeficiency Syndrome ◽

Urogenital System ◽

Hiv Virus ◽

The Central Nervous System ◽

Acquired Immunodeficiency ◽

A Minor ◽

Immunodeficiency Syndrome

Infection by Hiv virus affects the urogenital system in a minor percentage of cases in comparison to other organs such as the lungs, the central nervous system and the haemolymphopoietic system. In recent years however, with the continued spread of the disease, also urologists find themselves dealing with various urogenital pathologies that are presented in seropositive or fully-blown Aids patients. The Authors present their experience and describe the problems correlated to dealing with acquired immunodeficiency syndrome patients that are affected with urological pathologies.

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Central nervous system modulates the neuromechanical delay in a broad range for the control of muscle force

Journal of Applied Physiology ◽

10.1152/japplphysiol.00135.2018 ◽

2018 ◽

Vol 125 (5) ◽

pp. 1404-1410 ◽

Cited By ~ 24

Author(s):

A. Del Vecchio ◽

A. Úbeda ◽

M. Sartori ◽

J. M. Azorín ◽

F. Felici ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Motor Unit ◽

Neural Coding ◽

Neural Control ◽

Motor Units ◽

Force Generation ◽

Neural Drive ◽

Wide Range ◽

The Central Nervous System

Force is generated by muscle units according to the neural activation sent by motor neurons. The motor unit is therefore the interface between the neural coding of movement and the musculotendinous system. Here we propose a method to accurately measure the latency between an estimate of the neural drive to muscle and force. Furthermore, we systematically investigate this latency, which we refer to as the neuromechanical delay (NMD), as a function of the rate of force generation. In two experimental sessions, eight men performed isometric finger abduction and ankle dorsiflexion sinusoidal contractions at three frequencies and peak-to-peak amplitudes {0.5, 1, and 1.5 Hz; 1, 5, and 10 of maximal force [%maximal voluntary contraction (MVC)]}, with a mean force of 10% MVC. The discharge timings of motor units of the first dorsal interosseous (FDI) and tibialis anterior (TA) muscle were identified by high-density surface EMG decomposition. The neural drive was estimated as the cumulative discharge timings of the identified motor units. The neural drive predicted 80 ± 0.4% of the force fluctuations and consistently anticipated force by 194.6 ± 55 ms (average across conditions and muscles). The NMD decreased nonlinearly with the rate of force generation ( R2 = 0.82 ± 0.07; exponential fitting) with a broad range of values (from 70 to 385 ms) and was 66 ± 0.01 ms shorter for the FDI than TA ( P < 0.001). In conclusion, we provided a method to estimate the delay between the neural control and force generation, and we showed that this delay is muscle-dependent and is modulated within a wide range by the central nervous system. NEW & NOTEWORTHY The motor unit is a neuromechanical interface that converts neural signals into mechanical force with a delay determined by neural and peripheral properties. Classically, this delay has been assessed from the muscle resting level or during electrically elicited contractions. In the present study, we introduce the neuromechanical delay as the latency between the neural drive to muscle and force during variable-force contractions, and we show that it is broadly modulated by the central nervous system.

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