119 research outputs found

    A Method for Direct Measurement of the First-Order Mass Moments of Human Body Segments

    Get PDF
    We propose a simple and direct method for measuring the first-order mass moment of a human body segment. With the proposed method, the first-order mass moment of the body segment can be directly measured by using only one precision scale and one digital camera. In the dummy mass experiment, the relative standard uncertainty of a single set of measurements of the first-order mass moment is estimated to be 1.7%. The measured value will be useful as a reference for evaluating the uncertainty of the body segment inertial parameters (BSPs) estimated using an indirect method

    Visualization of nerve fibers around the carotid bifurcation with use of a 9.4 Tesla microscopic magnetic resonance diffusion tensor imaging with tractography

    Get PDF
    BACKGROUND: Precise imaging of nerves have been challenging in the head and neck region, mainly due to low spatial resolution. Here, we investigated how nerves in the head and neck region could be visualized using an ultra-high magnetic field MR system. METHODS: We used formol-carbol-fixed human cadaveric necks and obtained MR diffusion tensor images (DTIs) using a 9.4 Tesla (T) ultra-high magnetic field MR system. Afterward, we prepared tissue sections and checked the anatomic relationships between the neurons and the carotid artery in order to confirm that the visualized fibers are indeed neuron fibers. RESULTS: We were able to identify nerves, including the vagus nerve, the hypoglossal nerve, and the spinal-accessory nerve. Hematoxylin-eosin stained histological sections confirmed neuron fibers in the same anatomic position. CONCLUSION: This technique has the feasibility to be applied for a more accurate anatomic understanding, maybe even close to a histological level

    Increased CaV1.2 late current by a CACNA1C p.R412M variant causes an atypical Timothy syndrome without syndactyly

    Get PDF
    Timothy syndrome (TS) is a rare pleiotropic disorder associated with long QT syndrome, syndactyly, dysmorphic features, and neurological symptoms. Several variants in exon 8 or 8a of CACNA1C, a gene encoding the α-subunit of voltage-gated Ca2+ channels (Cav1.2), are known to cause classical TS. We identified a p.R412M (exon 9) variant in an atypical TS case. The aim of this study was to examine the functional effects of CACNA1C p.R412M on CaV1.2 in comparison with those of p.G406R. The index patient was a 2-month-old female infant who suffered from a cardio-pulmonary arrest in association with prolonged QT intervals. She showed dysmorphic facial features and developmental delay, but not syndactyly. Interestingly, she also presented recurrent seizures from 4 months. Genetic tests identified a novel heterozygous CACNA1C variant, p.R412M. Using heterologous expression system with HEK-293 cells, analyses with whole-cell patch-clamp technique revealed that p.R412M caused late Ca2+ currents by significantly delaying CaV1.2 channel inactivation, consistent with the underlying mechanisms of classical TS. A novel CACNA1C variant, p.R412M, was found to be associated with atypical TS through the same mechanism as p.G406R, the variant responsible for classical TS

    SCN5A mutations in 442 neonates and children: genotype-phenotype correlation and identification of higher-risk subgroups.

    Get PDF
    Aims To clarify the clinical characteristics and outcomes of children with SCN5A-mediated disease and to improve their risk stratification. Methods and results A multicentre, international, retrospective cohort study was conducted in 25 tertiary hospitals in 13 countries between 1990 and 2015. All patients ≤16 years of age diagnosed with a genetically confirmed SCN5A mutation were included in the analysis. There was no restriction made based on their clinical diagnosis. A total of 442 children {55.7% boys, 40.3% probands, median age: 8.0 [interquartile range (IQR) 9.5] years} from 350 families were included; 67.9% were asymptomatic at diagnosis. Four main phenotypes were identified: isolated progressive cardiac conduction disorders (25.6%), overlap phenotype (15.6%), isolated long QT syndrome type 3 (10.6%), and isolated Brugada syndrome type 1 (1.8%); 44.3% had a negative electrocardiogram phenotype. During a median follow-up of 5.9 (IQR 5.9) years, 272 cardiac events (CEs) occurred in 139 (31.5%) patients. Patients whose mutation localized in the C-terminus had a lower risk. Compound genotype, both gain- and loss-of-function SCN5A mutation, age ≤1 year at diagnosis in probands and age ≤1 year at diagnosis in non-probands were independent predictors of CE. Conclusion In this large paediatric cohort of SCN5A mutation-positive subjects, cardiac conduction disorders were the most prevalent phenotype; CEs occurred in about one-third of genotype-positive children, and several independent risk factors were identified, including age ≤1 year at diagnosis, compound mutation, and mutation with both gain- and loss-of-function

    Molecular Basis of the Ligand Binding Specificity of αvβ8 Integrin

    Get PDF
    This research was originally published in the Journal of Biological Chemistry. Akio Ozawa, Yuya Sato, Tsukasa Imabayashi, Toshihiko Uemura, Junichi Takagi and Kiyotoshi Sekiguchi. Molecular Basis of the Ligand Binding Specificity of αvβ8 Integrin. J. Biol. Chem. 2016; 291: 11551-11565 © the American Society for Biochemistry and Molecular Biolog
    corecore