PURPOSE: Extraocular muscle (EOM) consists of two layers, the global and the orbital layer, which are readily distinguished by their histopathology. This study was conducted to investigate the changes of myosin heavy chain (MHC) and MHC isoforms of the global and the orbital layers of EOM after tenotomy. METHODS: Twenty four New Zealand white rabbits were used. The rectus muscles were harvested on day 3, week 1, week 2, week 3, week 4, and week 8 after EOM tenotomy. The change of MHC amount was measured using an electrophoresis. The changes of MHC isoforms were also measured quantitatively using western blot immunostaining. RESULTS: The amount of total MHC, fast MHC isoform, and slow MHC isoform decreased maximally at 1-week after EOM tenotomy and recovered at 4-week and 8-week after tenotomy. There was no significant change in the amount of the neonatal and developmental MHC isoform. CONCLUSIONS: Fast and slow MHC isoform changed mainly due to the changes in the global layer rather than in the orbital layer after EOM tenotomy.
Blotting, Western ; Electrophoresis ; Muscles ; Myosin Heavy Chains* ; Myosins* ; Orbit ; Protein Isoforms* ; Rabbits* ; Tenotomy*

BACKGROUND: Osteopontin (OPN) is a cytokine associated with a cell-matrix via integrins. Fibroblast specific protein-1 (FSP-1), known as S100A4, has been implicated in cell migration by non-muscle myosin. We investigated whether the role of OPN and FSP-1/S100A4 expression in their contribution to the podocyte phenotype change to form podocyte bridge and cellular crescent. METHODS: Glomerular expression of OPN and FSP-1/S100A4 in renal biopsies of 16 patients with crescentic glomerulonephritis (CrGN) and 13 normal renal biopsies were studied by immunohistochemistry. RESULTS: The expression of OPN and FSP-1/S100A4 was increased in the podocytes of glomeruli, with and without crescents, in patients with CrGN. Neither OPN nor FSP-1/S100A4 was expressed in glomeruli from the normal controls (p<0.01). A significant positive correlation was found between the expression of OPN in glomerular tufts and cellular crescents, and the expression of OPN and FSP-1/S100A4 in glomerular tufts (p<0.05). CONCLUSIONS: The results suggest that OPN plays a role in early podocyte attachment to Bowman's capsule, and FSP-1/S100A4 potentiate podocyte contribution to cellular crescent formation by inducing cellular migration and growth.
Biopsy ; Bowman Capsule ; Cell Movement ; Fibroblasts ; Glomerulonephritis ; Humans ; Integrins ; Myosins ; Osteopontin ; Phenotype ; Podocytes

PURPOSE: To provide quantitative data on the distribution of MyHCeom and compare the proportion of myosin heavy chain (MyHC) isoforms between the central and peripheral regions of human extraocular muscles (EOMs). METHODS: Medial rectus, lateral rectus, superior rectus, inferior rectus, superior oblique, and inferior oblique muscle samples were taken from three men with brain death. To examine the longitudinal distribution of myosin isoforms, the muscles were divided into central and peripheral portions of equal length. Electrophoresis and densitometry were used to quantify the distribution of MyHC isoforms. RESULTS: Electrophoresis of whole-muscle extracts of sampled EOMs revealed four MyHC bands that were identified as MyHCI, MyHCeom, MyHCIIa, and MyHCIIx. The proportion of MyHCeom was higher in the central region, whereas the proportion of MyHCIIa was higher in the peripheral region. The relative proportions of MyHCI, MyHCeom, and MyHCIIa were not significantly different among the EOMs. There was a tendency for higher levels of MyHCIIx in the inferior rectus muscle. CONCLUSIONS: The proportion of MyHCeom was higher in the central region of human EOMs. Further studies are needed to investigate the consequences of this distributional difference on the function of EOMs.
Brain Death ; Densitometry ; Electrophoresis ; Humans ; Male ; Muscles ; Myosin Heavy Chains ; Myosins ; Protein Isoforms

Medullomyoblastoma is a very rare central nervous system tumor and is regarded to be a variant of medulloblastoma showing a rhabdomyoblastic component. We found 32 cases of medullomyoblastoma in English literature. We recently experienced a case of a cerebellar medullomyoblastoma with neuronal differentiation in a 15-year-old girl who displayed headaches and vomiting. The tumor displayed extensive neuronal and myoblastic differentiation on microscopic and immunohistochemical examination. On ultrastructural study, the tumor obviously demonstrated rhabdomyoblastic features showing myofilaments composed of actin and myosin with well developed Z-bands.
Actins ; Adolescent ; Central Nervous System ; Female ; Headache ; Humans ; Medulloblastoma* ; Myoblasts ; Myofibrils ; Myosins ; Neurons* ; Vomiting

PURPOSE: To study the changes in the amount and isoform pattern of the myosin heavy chain (MyHC) in rabbit extraocular muscle (EOM) fibers after recession. METHODS: Sixteen New Zealand white rabbits were used. Recession surgery was performed on the right superior rectus (SR) muscle by 3 mm in eight rabbits, and performed by 8 mm in other eight rabbits. The left SR muscles were left intact as the control groups. The SR muscles in both eyes were harvested from two rabbits from each recession group at 3 days and 1, 2, and 4 weeks after surgery. The changes in MyHC amount and isoform pattern were analyzed by gel electrophoresis. RESULTS: Total MyHC content decreased from 1 week after surgery in the 3-mm recessed group and from 3 days in the 8-mm group. The type IIb MyHC (MyHCIIb) plus EOM-specific MyHC (MyHCeom) showed similar proportional changes to the total MyHC at the different time points after surgery. CONCLUSIONS: The fast MyHCIIb plus the superfast MyHCeom decreased after EOM recession, and these results appear to be related to the changes in the global layer rather than in the orbital one. This suggests that the global layer might be the fast and the superfast twitch portions of rabbit EOM, which perform the fast saccades in ocular movements.
Electrophoresis ; Eye ; Muscles ; Myosin Heavy Chains ; Myosins ; Orbit ; Protein Isoforms ; Rabbits ; Saccades

PURPOSE: To study the changes in the amount and isoform pattern of the myosin heavy chain (MyHC) in rabbit extraocular muscle (EOM) fibers after recession. METHODS: Sixteen New Zealand white rabbits were used. Recession surgery was performed on the right superior rectus (SR) muscle by 3 mm in eight rabbits, and performed by 8 mm in other eight rabbits. The left SR muscles were left intact as the control groups. The SR muscles in both eyes were harvested from two rabbits from each recession group at 3 days and 1, 2, and 4 weeks after surgery. The changes in MyHC amount and isoform pattern were analyzed by gel electrophoresis. RESULTS: Total MyHC content decreased from 1 week after surgery in the 3-mm recessed group and from 3 days in the 8-mm group. The type IIb MyHC (MyHCIIb) plus EOM-specific MyHC (MyHCeom) showed similar proportional changes to the total MyHC at the different time points after surgery. CONCLUSIONS: The fast MyHCIIb plus the superfast MyHCeom decreased after EOM recession, and these results appear to be related to the changes in the global layer rather than in the orbital one. This suggests that the global layer might be the fast and the superfast twitch portions of rabbit EOM, which perform the fast saccades in ocular movements.
Electrophoresis ; Eye ; Muscles ; Myosin Heavy Chains ; Myosins ; Orbit ; Protein Isoforms ; Rabbits ; Saccades

We evaluated the muscle fiber characteristics, the mean proportion of muscle fiber types and its range of individual difference in human vertebral muscle. Muscle samples used were from subjects who had a relatively brief history of spinal dysfunction such as compression fracture, disc hernia etc., and obtained from precisely defined superficial and deep sites on both sides of the vertebral column. In particular, samples were collected from three different levels of the column and flash-frozen sections of biopsied adult vertebral muscles were stained for H–E, trichrome, PAS, regular and reversed myosin ATPase, and SDH. Discrimination of muscle fiber types in H–E and trichrome stained sections was not evident. Three types of muscle fibers were, however, evident in PAS-stained sections according to the degree of positivity in observed vertebral muscles. The mean proportion of musele fiber types was different in regular and reversed myosin ATPase, and SDH stains and the majority of fiber types in human vertebral muscles was type I in three different levels of vertebral clumn. There was a decreasing tendency in percentage of type I fibers at both superficial and deep levels as the vertebral column descended. The size of muscle fibers was relatively larger in deep levels than in superficial levels of vertebral muscles. The human vertebral muscle showed moderately individual and regional differences in the mean size of fiber types. The evaluation for the combination patterns of various enzyme histochemical activities showed that the common musele fiber types(type I, II A and II B) were moderately reduced in the mean proportions and unusual rare muscle fiber types increased in number. And the decreasing tendency in the mean proportion of type as the vertebral column descended was not evident in the combination patterns of histochemical activities
Adult ; Coloring Agents ; Discrimination (Psychology) ; Fractures, Compression ; Hernia ; Humans ; Individuality ; Muscles ; Myosins ; Spine

There have been numerous hypotheses about the pathogenesis of idiopathic scoliosis, but it is still unclear. There are some reports that abnormalities of contractile proteins may play a role in the pathogenesis of idiopathic scoliosis. The purpose of this report is to study the quantitative abnormalities of contractile proteins in muscles and nonactivated and activated platelets, and to determine whether or not the abnormalities in contractile proteins may play a role in the pathogenesis of idiopathic scoliosis. The materials were 21 idiopathic scoliosis patients aged from 13 years to 28 years(average 19.2 years) and 20 persons aged from 17 years to 25 years(average 20.1 years) as a control group. The electrophoretic analysis(SDS-PAGE method) was done on platelets both unstimulated and stimulated with thrombin and also on proteins of paraspinal muscles and gluteus maximus of idiopathic scoliosis patient and paraspinal muscles of control group. The results are as follows. 1. The myosin/actin ratios of triton-insoluble fractions to paraspinal muscles in convex sides of main curvatures of scoliosis patients(1.69±0.81) were significantly decreased compared to those of concave sides(2.55±1.28), gluteus maximus muscles(2.56±1.70) and control group(2.61±1.01). 2. There were no significant differences between scoliosis group and control group in the actin/myosin ratios of triton-insoluble fractions of the platelets both nonactivated and activated by thrombin. In conclusion, abnormalities of contractile protein in paraspinal muscles of convex side may play a role in the pathogenesis of idiopathic scoliosis, rather than abnormalities of systemic contractile protein.
Actins ; Blood Platelets ; Contractile Proteins ; Humans ; Muscles ; Myosins ; Paraspinal Muscles ; Scoliosis ; Thrombin

It is the aim of this study to determine the effects of facial denervation on physiological properties of facial muscles and facial bones in growing rabbits. Experimental animals of fifty two Oryctolagus cuniculus rabbits were employed. Unilateral dissection of facial nerve was carried out on twelve rabbits, bilateral dissection of facial nerve was made on another twelve rabbits and the other twenty rabbits were on unilateral dissection of facial nerve for the histochemical analyses. Six rabbits on the bilateral surgical sham operations and six rabbits of non-intervention served the control groups. EMG records of the orbicularis oris, buccinator and masseter muscles as well as lateral and dorsoventral cephalometric films were taken and analyzed at 0, I, 2, 5 and 8 weeks respectively. The orbicularis oris, buccinator and masseter muscles of both sides were removed from the animals of the histochemistry group and muscle fibers were classified on the basis of histochemical staining for alpha-GPD, NADH-D and myosin ATPase. EMG activities of orbicularis oris and buccinator muscles were vanished immediately after denervation. Recovery of activities were detected one week after denervation in buccinator and five weeks in orbicularis oris muscles. Histochemical properties of masseter muscles remained as fast glycolytic through the experimental period. Orbicularis oris muscle fibers showed the gradual diminution of size and ratio of the slow oxidative fibers accompanied with atrophy, phagocytosis and vacuolation as well as the augmentation of fast oxidative glycolytic fibers. The buccinator muscle manifested the augmentation of fast oxidative glycolytic fibers at five weeks of experiment. Visual changes in morphology of craniofacial area were not evident, however it variety of subtle changes were apparent from statistical analysis of cephalometric measurements. It is concluded facial nerve regulates the physiological properties of facial muscles and interrelation between the function of the facial muscles and changes of facial bones would be in some degrees.
Animals ; Atrophy ; Denervation* ; Facial Bones ; Facial Muscles* ; Facial Nerve ; Masseter Muscle ; Muscles ; Myosins ; Phagocytosis ; Rabbits*

OBJECTIVE: To explore the genetic basis for a family with non-syndromic autosomal recessive deafness. METHODS: The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents. RESULTS: The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c.462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father. CONCLUSION The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.
Female ; Hearing Loss, Sensorineural ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Male ; Mutation ; Myosins ; genetics ; Pedigree