OBJECTIVE: To explore mutational characteristics of acute myeloid leukemia (AML) patients with CBFβ-MYH11⁺ and analyze the correlation between the mutations and partial clinical characteristics. METHODS: A total of 62 AML patients with CBFβ-MYH11⁺ were included and 51 candidate genes were screened for their mutations using targeted next-generation sequencing (NGS). The exon 12 of NPM1 , FLT3-ITD , and TAD, bZIP domains of CEBPA were detected by genomic DNA-PCR combined with sanger sequencing. RESULTS: Compared with RUNX1-RUNX1T1 ⁺ group, the patients with CBFβ-MYH11⁺ showed higher age, peripheral WBC level, initial induced complete remission (CR) rate, more commonly carried chromosomal abnormalities such as +22, and lower deletion ratio of sex chromosome (-X or -Y) (P<0.05). In AML patients with CBFβ-MYH11⁺, the most common mutation was NRAS , followed by KIT, KRAS , and FLT3-TKD . Compared with RUNX1-RUNX1T1⁺ group, NRAS and FLT3-TKD were more frequently mutated in patients with CBFβ-MYH11⁺ (51.6% vs 18.7%, 17.7% vs 3.8%) (P<0.05). CONCLUSION The genomic landscape and clinical characteristics of AML patients with CBFβ-MYH11⁺ are different from patients with RUNX1-RUNX1T1 ⁺.
Humans ; Genomics ; Leukemia, Myeloid, Acute/genetics* ; Myosin Heavy Chains

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

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*

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

PURPOSE: Extraocular muscle (EOM) consists of two layers, orbital and global layers which are readily distinguished by their histology. This study was conducted to investigate the changes of histology, myosin heavy chain (MHC), and MHC isoforms of the global and orbital layers of EOM after tenotomy. METHODS: Forty-two New Zealand white rabbits were used. The rectus muscles were harvested at day 3, week 1, week 2, week 4, and week 8 after EOM tenotomy. EOM mass change was measured. The EOM were serially sectioned in coronal plane and stained with Masson's trichrome. The diameters of muscle fibers and cross sectional areas of two layers were measured in the middle of the muscles. Changes of MHC isoforms were also measured using immunohistochemistry. RESULTS: The EOM mass was decreased at all periods of surgery especially at day 3 and week 1, increased maximally at week 8. The diameters of EOM fibers in global layer were decreased at day 3, week 1, and week 2 after EOM tenotomy and increased maximally at week 8. The immunohistochemical stains of fast and slow MHC were weakened in the global layer at week 1 after tenotomy. CONCLUSIONS: EOM changes due to atrophy appeared at day 3, week 1, and week 2 after EOM tenotomy while EOM atrophy was recovered at week 4 and week 8 after the surgery. These changes did not appear on the EOM orbital layer but was shown in EOM global layer. These results were due to the histological and functional differences between the EOM global and orbital layers.
Atrophy ; Coloring Agents ; Immunohistochemistry ; Muscles ; Myosin Heavy Chains ; Orbit ; Protein Isoforms ; Rabbits ; Tenotomy*

May-Hegglin anomaly (MHA) is an autosomal dominant disorder characterized by macrothrombocytopenia and leukocyte inclusions. In 1992, we reported the first Korean case of MHA family. Again, in this family, we identified a nonsense C5797T mutation (R1933X) in the MYH9 gene, encoding non-muscle myosin heavy chain A. To the best of our knowledge, our genetic study in this MHA family is the first report of mutation resulting in the truncation of 28 of 34 amino acids of the carboxy-terminal tailpiece of the myosin heavy chain in Korea.
Amino Acids ; Humans ; Inclusion Bodies ; Korea ; Leukocytes ; Myosin Heavy Chains ; Myosins

OBJECTIVE: The purpose of this study is to compare muscle strength, endurance and the change of myosin heavy chain isoform after sprint training(ST) and heavy resistance training(HRT). METHOD: Fourteen young athletes were enrolled and were randomly assigned into each training group. Before and after training for 8 weeks, the strength and the endurance were evaluated using isokinetic exercise system(Cybex 6000). The specimens of muscle biopsy were obtained from vastus lateralis muscle and were analysed for muscle fiber type using one dimensional electrophoresis. RESULTS: Peak torque, total work and mean power were increased significantly in both groups, but endurance ratio increased only in the sprint training group(P<0.05). The proportions of myosin heavy chain(MHC) IIa fibers were increased in both groups and those of MHC IIb fibers were decreased in both groups(P<0.05). MHC I fibers were significantly increased in ST group, but decresed in HRT group(P>0.05). CONCLUSION: This study shows that it is possible to increase muscle strength and to achieve fiber type transformation with the sprint training and the high resistance training.
Athletes ; Biopsy ; Electrophoresis ; Humans ; Muscle Strength* ; Myosin Heavy Chains ; Myosins ; Quadriceps Muscle ; Resistance Training* ; Torque

OBJECTIVE: To analyze the prognostic factors of AML children with CBFβ/MYH11 positive. METHODS: Twenty-eight children with CBFβ/MYH11 positive treated in our hospital from May 2012 to June 2018 were selected, the clinical data and curative were analyzed and evaluated. RESULTS: Five-year OS and 5-year EFS rate of CBFβ/MYH11 positive AML children was 76.8% and 64.0% efficacy, respectively. Univariate analysis results showed that the OS rate of CBFβ/MYH11 positive AML children with WBC<60.0×10 CONCLUSION WBC level and XRCC-Thr241Met genotype at initial diagnosis are the major affecting factors for prognosis of AML children with CBFβ/MYH11 positive.
Child ; Chromosome Inversion ; Genotype ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Myosin Heavy Chains ; Oncogene Proteins, Fusion ; Prognosis

OBJECTIVE: To identify the mutation type of non-muscle myosin heavy chain 9 (MYH9) gene and investigate the clinical features of a pedigree affected with MYH9 gene-related disease. METHODS: Peripheral blood samples of the proband and his family members were collected. Routine blood tests were performed, which included platelet counting and Wright's staining to observe the granulocyte inclusions and giant platelets. PCR was used to amplify exons 2, 17, 27, 31, 39 and 41 of the MYH9 gene, and the mutation site was determined by Sanger sequencing. RESULTS: All patients from the pedigree presented a typical triad of thrombocytopenia, giant platelets, and inclusion bodies in leukocytes. In addition, two patients had nephritis and cataract. All affected members carried a heterozygous missense mutation of c.5521G>A (p.glu1841Lys) in exon 39 of the MYH9 gene. The same mutation was not found among healthy members of the pedigree and the controls. CONCLUSION The c.5521G>A (p.Glu1841Lys) mutation in the MYH9 gene probably underlies the MYH9-related disease in this pedigree.
Female ; Genetic Testing ; Humans ; Male ; Molecular Motor Proteins ; genetics ; Mutation ; Myosin Heavy Chains ; genetics ; Pedigree ; Thrombocytopenia