Myofibers in tongues of Down's syndrome

Yarom, R.; Sagher, U; Havivi, Y.; Peled, Isaac J.; Wexler, Menachem R.

doi:10.1016/0022-510x(86)90152-8

Cited by 34 publications

(11 citation statements)

References 8 publications

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“…Cu/Zn-SOD transgenic mice also exhibit signs of premature aging and neuromuscular dysfunction (30 -32, 648). The neuromuscular junctions of the leg muscles from these mice were found to exhibit pathological changes that are similar to those observed in the skeletal muscle tissue of aging rats and mice (95,172) and in the tongue muscles of individuals with Down's syndrome (646,647).…”

Section: Neurodegenerative Diseasesmentioning

confidence: 60%

Free Radicals in the Physiological Control of Cell Function

Dröge

2002

Physiological Reviews

8,452

5,836

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At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, however, nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS) play an important role as regulatory mediators in signaling processes. Many of the ROS-mediated responses actually protect the cells against oxidative stress and reestablish “redox homeostasis.” Higher organisms, however, have evolved the use of NO and ROS also as signaling molecules for other physiological functions. These include regulation of vascular tone, monitoring of oxygen tension in the control of ventilation and erythropoietin production, and signal transduction from membrane receptors in various physiological processes. NO and ROS are typically generated in these cases by tightly regulated enzymes such as NO synthase (NOS) and NAD(P)H oxidase isoforms, respectively. In a given signaling protein, oxidative attack induces either a loss of function, a gain of function, or a switch to a different function. Excessive amounts of ROS may arise either from excessive stimulation of NAD(P)H oxidases or from less well-regulated sources such as the mitochondrial electron-transport chain. In mitochondria, ROS are generated as undesirable side products of the oxidative energy metabolism. An excessive and/or sustained increase in ROS production has been implicated in the pathogenesis of cancer, diabetes mellitus, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and other diseases. In addition, free radicals have been implicated in the mechanism of senescence. That the process of aging may result, at least in part, from radical-mediated oxidative damage was proposed more than 40 years ago by Harman ( J Gerontol 11: 298–300, 1956). There is growing evidence that aging involves, in addition, progressive changes in free radical-mediated regulatory processes that result in altered gene expression.

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Section: Neurodegenerative Diseasesmentioning

confidence: 60%

Free Radicals in the Physiological Control of Cell Function

Dröge

2002

Physiological Reviews

8,452

5,836

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“…Unfortunately, there are few reports on fibre types in the human genioglossus. YAROM et al [13] reported that tongue muscles (no differentiation among muscles was reported) were composed of 30±40% slow-twitch fibres in patients with Down syndrome. SERIES et al [14] recently demonstrated that the genioglossus contains 33% type I fibres and 67% type II fibres in both snorers and patients with obstructive sleep apnoea.…”

Section: Discussionmentioning

confidence: 99%

Functional divergence of human genioglossus motor units with respiratory-related activity

Tsuiki¹,

Ono²,

Ishiwata³

et al. 2000

Eur Respir J

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The genioglossus muscle has at least two types of motor unit with respiratory-related activity. Inspiratory motor units show phasic activity during inspiration, whereas inspiratory/expiratory motor units show phasic inspiratory activity superimposed on tonic activity. The purpose of this study was to investigate the physiological roles of these different genioglossus motor units.The unitary activities of 12 inspiratory and 12 inspiratory/expiratory motor units were recorded using fine-wire electrodes during quiet nasal breathing in eight normal adult males. The mean interspike interval and the SD of successive spikes were calculated for inspiratory and inspiratory/expiratory motor units, respectively. Scattergrams of the mean interspike interval versus SD were constructed for the two groups of motor units.The effects of changes in head position on the firing activity and the patterns of distribution of the mean interspike interval versus SD were significantly different for inspiratory and inspiratory/expiratory motor units.These results suggest that the inspiratory and inspiratory/expiratory motor units have different functional roles in respiration; inspiratory motor units may be phasically active to counteract intraluminal negative pressure during inspiration, whereas inspiratory/expiratory motor units may be tonically active to maintain tongue posture. Eur Respir J 2000; 15: 906±910.

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“…Similarly, Guimaraes, Donnelly, Shott, Amin, & Kalra (2008) concluded that children with DS do not have true macroglossia but rather have relatively large tongues compared to the bony confines of the oral cavity. Evidence also has been reported on abnormalities of the myofibers of the tongue (Yarom, Sagher, Havivi, Peied & Wexler, 1986). …”

Section: Speech Sound Disorders (Table 2)mentioning

confidence: 92%

Speech Impairment in Down Syndrome: A Review

Kent

Vorperian

2013

J Speech Lang Hear Res

192

145

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Purpose This review summarizes research on disorders of speech production in Down Syndrome (DS) for the purposes of informing clinical services and guiding future research. Method Review of the literature was based on searches using Medline, Google Scholar, Psychinfo, and HighWire Press, as well as consideration of reference lists in retrieved documents (including online sources). Search terms emphasized functions related to voice, articulation, phonology, prosody, fluency and intelligibility. Conclusions The following conclusions pertain to four major areas of review: (a) Voice. Although a number of studies have been reported on vocal abnormalities in DS, major questions remain about the nature and frequency of the phonatory disorder. Results of perceptual and acoustic studies have been mixed, making it difficult to draw firm conclusions or even to identify sensitive measures for future study. (b) Speech sounds. Articulatory and phonological studies show that speech patterns in DS are a combination of delayed development and errors not seen in typical development. Delayed (i.e., developmental) and disordered (i.e., nondevelopmental) patterns are evident by the age of about 3 years, although DS-related abnormalities possibly appear earlier, even in infant babbling. (c) Fluency and prosody. Stuttering and/or cluttering occur in DS at rates of 10 to 45%, compared to about 1% in the general population. Research also points to significant disturbances in prosody. (d) Intelligibility. Studies consistently show marked limitations in this area but it is only recently that research goes beyond simple rating scales.

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Myofibers in tongues of Down's syndrome

Cited by 34 publications

References 8 publications

Free Radicals in the Physiological Control of Cell Function

Free Radicals in the Physiological Control of Cell Function

Functional divergence of human genioglossus motor units with respiratory-related activity

Speech Impairment in Down Syndrome: A Review

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