Peripheral Nerve Findings in Rett Syndrome

1988 ◽  
Vol 3 (1_suppl) ◽  
pp. S25-S30 ◽  
Author(s):  
Richard H. Haas ◽  
Seth Love
Keyword(s):  
Rett Syndrome ◽  
Sural Nerve ◽  
Enzyme Histochemistry ◽  
Axonal Neuropathy ◽  
Type I ◽  
Normal Density ◽  
Hirano Bodies ◽  
Peroneus Brevis ◽  
Type I Fibers ◽  
Muscle Biopsies

Sural nerve and peroneus brevis muscle biopsies were studied in 12 patients with Rett syndrome, ten with the typical form of the disorder according to 1985 criteria, and two with atypical features. Ages ranged from 23 months to 25 years. All stages of the disease were represented. There was evidence of a mild axonal neuropathy in seven of 12 patients. Degenerative and occasional regenerative changes were seen in five sural nerve biopsies, including one from the youngest patient in the series, who was normally nourished and fully ambulatory. Occasional nonspecific ultrastructural abnormalities were present, including accumulation of pi granules in Schwann cells and Hirano bodies within axons. However, morphometric analysis of the four nerves in which these alterations were most prominent showed a normal density and size distribution of myelinated fibers. Enzyme histochemistry of the peroneus brevis biopsies demonstrated abnormal predominance of type II muscle fibers in three of the 12 biopsies and atrophy of type I fibers in one patient. (J Child Neurol 1988;3(Suppl):S25-S30).

scholarly journals Skeletal muscle lipid droplets are resynthesized before being coated with perilipin proteins following prolonged exercise in elite male triathletes

2020 ◽  
Vol 318 (3) ◽  
pp. E357-E370 ◽  
Author(s):  
Emily F. P. Jevons ◽  
Kasper D. Gejl ◽  
Juliette A. Strauss ◽  
Niels Ørtenblad ◽  
Sam O. Shepherd
Keyword(s):  
Prolonged Exercise ◽  
Fiber Type ◽  
Moderate Intensity ◽  
Type I ◽  
Muscle Lipid ◽  
Confocal Immunofluorescence Microscopy ◽  
Confocal Immunofluorescence ◽  
Skeletal Muscle Lipid ◽  
Type I Fibers ◽  
Muscle Biopsies

Intramuscular triglycerides (IMTG) are a key substrate during prolonged exercise, but little is known about the rate of IMTG resynthesis in the postexercise period. We investigated the hypothesis that the distribution of the lipid droplet (LD)-associated perilipin (PLIN) proteins is linked to IMTG storage following exercise. Fourteen elite male triathletes (27 ± 1 yr, 66.5 ± 1.3 mL·kg−1·min−1) completed 4 h of moderate-intensity cycling. During the first 4 h of recovery, subjects received either carbohydrate or H2O, after which both groups received carbohydrate. Muscle biopsies collected pre- and postexercise and 4 and 24 h postexercise were analyzed using confocal immunofluorescence microscopy for fiber type-specific IMTG content and PLIN distribution with LDs. Exercise reduced IMTG content in type I fibers (−53%, P = 0.002), with no change in type IIa fibers. During the first 4 h of recovery, IMTG content increased in type I fibers ( P = 0.014), but was not increased more after 24 h, where it was similar to baseline levels in both conditions. During recovery the number of LDs labeled with PLIN2 (70%), PLIN3 (63%), and PLIN5 (62%; all P < 0.05) all increased in type I fibers. Importantly, the increase in LDs labeled with PLIN proteins only occurred at 24 h postexercise. In conclusion, IMTG resynthesis occurs rapidly in type I fibers following prolonged exercise in highly trained individuals. Furthermore, increases in IMTG content following exercise preceded an increase in the number of LDs labeled with PLIN proteins. These data, therefore, suggest that the PLIN proteins do not play a key role in postexercise IMTG resynthesis.

Histochemistry of the Triceps Surae Muscle in Idiopathic Congenital Clubfoot

Foot & Ankle ◽  
1992 ◽  
Vol 13 (2) ◽  
pp. 80-84 ◽  
Author(s):  
Nicola Maffulli ◽  
Giovanni Capasso ◽  
Vittorino Testa ◽  
Luigi Borrelli
Keyword(s):  
Capillary Density ◽  
Triceps Surae ◽  
Idiopathic Clubfoot ◽  
Type I ◽  
Fiber Types ◽  
Congenital Clubfoot ◽  
Triceps Surae Muscle ◽  
Affected Side ◽  
Type I Fibers ◽  
Muscle Biopsies

The histochemical composition of the triceps surae muscle was investigated in 13 previously unoperated children (age 9–24 months) with unilateral idiopathic clubfoot. On both the normal and the affected side, the percentage of type I fibers was significantly higher than that of the other fiber types. The muscle biopsies from the clubfoot side showed an increase in their connective tissue content. The affected side showed a nonsignificant higher percentage of type I fibers, whereas the average capillary density and capillary to fiber ratio were significantly lower.

Distribution of myogenic progenitor cells and myonuclei is altered in women with vs. those without chronically painful trapezius muscle

2010 ◽  
Vol 109 (6) ◽  
pp. 1920-1929 ◽  
Author(s):  
Abigail L. Mackey ◽  
Lars L. Andersen ◽  
Ulrik Frandsen ◽  
Charlotte Suetta ◽  
Gisela Sjøgaard
Keyword(s):  
Cross Sections ◽  
Trapezius Muscle ◽  
Motor Units ◽  
Type I ◽  
Trapezius Myalgia ◽  
Low Threshold ◽  
Myogenic Progenitor Cells ◽  
Type I Fibers ◽  
Muscle Biopsies ◽  
Type Ii Fibers

It is hypothesized that repeated recruitment of low-threshold motor units is an underlying cause of chronic pain in trapezius myalgia. This study investigated the distribution of satellite cells (SCs), myonuclei, and macrophages in muscle biopsies from the trapezius muscle of 42 women performing repetitive manual work, diagnosed with trapezius myalgia (MYA; 44 ± 8 yr; mean ± SD) and 20 matched healthy controls (CON; 45 ± 9 yr). Our hypothesis was that muscle of MYA, in particular type I fibers, would demonstrate higher numbers of SCs, myonuclei, and macrophages compared with CON. SCs were identified on muscle cross sections by combined immunohistochemical staining for Pax7, type I myosin, and laminin, allowing the number of SCs associated with type I and II fibers to be determined. We observed a pattern of SC distribution in MYA previously only reported for individuals above 70 yr of age. Compared with CON, MYA demonstrated 19% more SCs per fiber associated with type I fibers (MYA 0.098 ± 0.039 vs. CON 0.079 ± 0.031; P < 0.05) and 40% fewer SCs associated with type II fibers (MYA 0.047 ± 0.017 vs. CON 0.066 ± 0.035; P < 0.05). The finding of similar numbers of macrophages between the two groups was not in line with our hypothesis and suggests that the elevated SC content of MYA was not due to heightened inflammatory cell contents, but rather to provide new myonuclei. The findings of greater numbers of SCs in type I fibers of muscle subjected to repeated low-intensity work support our hypothesis and provide new insight into stimuli capable of regulating SC content.

scholarly journals Nemaline myopathy: clinical, histochemical and immunohistochemical features

2009 ◽  
Vol 67 (3b) ◽  
pp. 886-891 ◽  
Author(s):  
Nazah Cherif Mohamad Youssef ◽  
Rosana Herminia Scola ◽  
Paulo José Lorenzoni ◽  
Lineu César Werneck
Keyword(s):  
Expression Patterns ◽  
Immunohistochemical Analysis ◽  
Nemaline Myopathy ◽  
Severe Form ◽  
Intermediate Form ◽  
Type I ◽  
Feeding Difficulties ◽  
Fast Myosin ◽  
Type I Fibers ◽  
Muscle Biopsies

Nemaline myopathy (NM) is a congenital disease that leads to hypotonia and feeding difficulties in neonates. Some cases have a more benign course, with skeletal abnormalities later in life. We analyzed a series of eight patients with NM obtained from a retrospective analysis of 4300 muscle biopsies. Patients were classified as having the typical form in five cases, intermediate form in two cases and severe form in one case. Histochemical analysis showed mixed rods distribution in all cases and predominance of type I fibers in five cases. Immunohistochemical analysis showed abnormal nebulin expression in all patients (four heterogeneous and four absent), homogeneous desmin expression in four cases, strongly positive in three and absent in one, fast myosin expression in a mosaic pattern in six cases and absent in two cases. There was no specific relation between these protein expression patterns and the clinical forms of NM.

scholarly journals The Syndrome of Carnitine Deficiency: Morphological and Metabolic Correlations in Two Cases

1978 ◽  
Vol 5 (2) ◽  
pp. 205-213 ◽  
Author(s):  
G. Scarlato ◽  
G. Pellegrini ◽  
C. Cerri ◽  
G. Meola ◽  
A. Veicsteinas
Keyword(s):  
Lactic Acid ◽  
Muscle Tissue ◽  
Clinical Manifestations ◽  
Carnitine Deficiency ◽  
Type I ◽  
Work Intensity ◽  
Morphological Alterations ◽  
Ultrastructural Studies ◽  
First Case ◽  
Type I Fibers

SUMMARY:Two cases of systemic carnitine deficiency are described. In both patients, carnitine concentration was lower than normal in serum and muscle tissue. In the first case, the illness began at age 35; the clinical manifestations were only muscular. In the second case, the illness began in childhood; there were intermittent episodes of hepatic enlargement and coma. An excessive lipid content was present in muscle tissue, especially in type I fibers, of both cases, and in the liver of the second patient. Ultrastructural studies of muscle tissue revealed important changes of mitochondria.During muscular exercise, aerobic and anaerobic metabolism were in vestigated. For a given relative work intensity, these patients showed abnormally high blood lactic acid concentration and lactic acid/pyruvic acid ratios. These data, together with the morphological alterations observed in mitochondria, suggest an impaired function of the respiratory chain, leading to a shift of the red/ox potential of the tissue towards a non reduced state.

Rostrocaudal pattern of fiber-type changes in an overloaded rat ankle extensor

1991 ◽  
Vol 71 (2) ◽  
pp. 558-564 ◽  
Author(s):  
P. F. Gardiner ◽  
B. J. Jasmin ◽  
P. Corriveau
Keyword(s):  
Fiber Type ◽  
Muscle Length ◽  
Similar Degree ◽  
Complex Nature ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Cross Sectional ◽  
Hypertrophic Response ◽  
Type I Fibers

Our aim was to quantify the overload-induced hypertrophy and conversion of fiber types (type II to I) occurring in the medial head of the gastrocnemius muscle (MG). Overload of MG was induced by a bilateral tenotomy/retraction of synergists, followed by 12–18 wk of regular treadmill locomotion (2 h of walking/running per day on 3 of 4 days). We counted all type I fibers and determined type I and II mean fiber areas in eight equidistant sections taken along the length of control and overloaded MG. Increase in muscle weights (31%), as well as in total muscle cross-sectional areas (37%) and fiber areas (type I, 57%; type II, 34%), attested to a significant hypertrophic response in overloaded MG. An increase in type I fiber composition of MG from 7.0 to 11.5% occurred as a result of overload, with the greatest and only statistically significant changes (approximately 70–100%) being found in sections taken from the most rostral 45% of the muscle length. Results of analysis of sections taken from the largest muscle girth showed that it significantly underestimated the extent of fiber conversion that occurred throughout the muscle as a whole. These data obtained on the MG, which possesses a compartmentalization of fiber types, support the notion that all fiber types respond to this model with a similar degree of hypertrophy. Also, they emphasize the complex nature of the adaptive changes that occur in these types of muscles as a result of overload.

Metabolic response in type I and type II muscle fibers during a 30-s cycle sprint in men and women

1999 ◽  
Vol 87 (4) ◽  
pp. 1326-1332 ◽  
Author(s):  
Mona Esbjörnsson-Liljedahl ◽  
Carl Johan Sundberg ◽  
Barbara Norman ◽  
Eva Jansson
Keyword(s):  
Gender Difference ◽  
Glycogen Content ◽  
Metabolic Response ◽  
Muscle Fibers ◽  
Type I ◽  
Type Ii ◽  
Men And Women ◽  
Sprint Exercise ◽  
Exercise Induced ◽  
Type I Fibers

The acute metabolic response to sprint exercise was studied in 20 male and 19 female students. We hypothesized that the reduction of muscle glycogen content during sprint exercise would be smaller in women than in men and that a possible gender difference in glycogen reduction would be higher in type II than in type I fibers. The exercise-induced increase in blood lactate concentration was 22% smaller in women than in men. A considerable reduction of ATP (50%), phosphocreatine (83%), and glycogen (35%) was found in type II muscle fibers, and it did not differ between the genders. A smaller reduction of ATP (17%) and phosphocreatine (78%) was found in type I fibers, and it did not differ between the genders. However, the exercise-induced reduction in glycogen content in type I fibers was 50% smaller in women than in men. The hypothesis was indeed partly confirmed: the exercise-induced glycogen reduction was attenuated in women compared with men, but the gender difference was in type I rather than in type II fibers. Fiber-type-specific and gender-related differences in the metabolic response to sprint exercise might have implications for the design of training programs for men and women.

Genetic and other determinants of AMP deaminase activity in healthy adult skeletal muscle

1998 ◽  
Vol 85 (4) ◽  
pp. 1273-1278 ◽  
Author(s):  
Barbara Norman ◽  
Donna K. Mahnke-Zizelman ◽  
Amy Vallis ◽  
Richard L. Sabina
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Mutant Allele ◽  
Fiber Type ◽  
Type I ◽  
Training Status ◽  
Amp Deaminase ◽  
Normal Allele ◽  
Relative Percentage ◽  
Type I Fibers

AMPD1 genotype, relative fiber type composition, training status, and gender were evaluated as contributing factors to the reported variation in AMP deaminase enzyme activity in healthy skeletal muscle. Multifactorial correlative analyses demonstrate that AMPD1 genotype has the greatest effect on enzyme activity. An AMPD1 mutant allele frequency of 13.7 and a 1.7% incidence of enzyme deficiency was found across 175 healthy subjects. Homozygotes for the AMPD1 normal allele have high enzyme activities, and heterozygotes display intermediate activities. When examined according to genotype, other factors were found to affect variability as follows: AMP deaminase activity in homozygotes for the normal allele exhibits a negative correlation with the relative percentage of type I fibers and training status. Conversely, residual AMP deaminase activity in homozygotes for the mutant allele displays a positive correlation with the relative percentage of type I fibers. Opposing correlations in different homozygous AMPD1 genotypes are likely due to relative fiber-type differences in the expression of AMPD1 and AMPD3 isoforms. Gender also contributes to variation in total skeletal muscle AMP deaminase activity, with normal homozygous and heterozygous women showing only 85–88% of the levels observed in genotype-matched men.

Effect of heavy-resistance exercise training on muscle fiber composition in young rats

1990 ◽  
Vol 69 (2) ◽  
pp. 434-437 ◽  
Author(s):  
K. E. Yarasheski ◽  
P. W. Lemon ◽  
J. Gilloteaux
Keyword(s):  
Exercise Training ◽  
Resistance Exercise ◽  
Muscle Fiber ◽  
Rectus Femoris ◽  
Type I ◽  
Resistance Exercise Training ◽  
Fiber Composition ◽  
Deep Region ◽  
Heavy Resistance Exercise ◽  
Type I Fibers

The purpose of this investigation was to determine whether heavy-resistance exercise training alters the skeletal muscle fiber composition of young rats. Ten male Long Evans rats (3 wk old) were trained to lift progressively heavier weights, which were secured to the rats' tails, while they ascended a 40-cm 90 degree mesh incline 20 times/day 5 days/wk for a food reward. After 8 wk of training, they lifted 406 +/- 19 (SD) g in addition to their body weight (261 +/- 9 g). Compared with 10 sedentary pair-fed rats, no hypertrophy of forelimb muscles (biceps brachii and brachialis) was observed, but rectus femoris wet and dry weights were greater (P less than 0.01) in the trained group. In the deep region of the rectus femoris, type I fiber area was similar between groups, but the trained rats had both a lower (P less than 0.05) percentage of type I fibers and a smaller (P less than 0.05) portion of the total area occupied by type I fibers. The percentage of type IIb fibers in the deep region of the rectus femoris was also similar between groups, but the portion of the deep area composed of type IIb fibers was greater (P less than 0.05) in the trained rats. In the superficial region of the rectus femoris, the trained rats' type IIb fibers were larger (P less than 0.01) and occupied a greater (P less than 0.05) portion of the superficial muscle area.(ABSTRACT TRUNCATED AT 250 WORDS)

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