Isolation of Nebulin from Rabbit Skeletal Muscle and Its Interaction with Actin

Nebulin is about 800 kDa filamentous protein that binds the entire thin filament of vertebrate skeletal muscle sarcomeres. Nebulin cannot be isolated from muscle except in a completely denatured form by direct solubilization of myofibrils with SDS because nebulin is hardly soluble under salt conditions. In the present study, nebulin was solubilized by a salt solution containing 1 M urea and purified by DEAE-Toyopearl column chromatography via 4 M urea elution. Rotary-shadowed images of nebulin showed entangled knit-like particles, about 20 nm in diameter. The purified nebulin bound to actin filaments to form loose bundles. Nebulin was confirmed to bind actin, α-actinin, β-actinin, and tropomodulin, but not troponin or tropomyosin. The data shows that full-length nebulin can be also obtained in a functional and presumably native form, verified by data from experiments using recombinant subfragments

Effect of Salivation by Facial Somatosensory Stimuli of Facial Massage and Vibrotactile Apparatus

We studied the effects of salivary promotion of fluid secretion after hand massage, and the apparatus of vibrotactile stimulation (89 Hz frequency, 15 min) in normal humans. Personal massage cannot be performed on handicap and stroke patients, and then giving hand massage to them for 5 min massage gives a tired feeling. So, we focused 3 min stranger massage. Salivary glands can discharge the accumulated saliva by extrusion from the acinus glands’ massages as described in the recent Japanese textbook. We think that this method may not produce realistic recovery. Our aim ideas are to relieve stress and increase temperature with lightly touch massage of the skin and for a 1 cycle of 1 s. We recorded RR interval of ECG, total salivation, facial skin temperature, OxyHb of fNIRS on the frontal cortex, and amylase activity for the autonomic changes. In increased 2°C of the facial skin temperature, the hand massage had a need for 3 min and the vibrotactile stimulation for 15 min. Increase from 700 to 1000 ms of RR intervals had a need for 3 min in the hand massage and had 15 min in the vibrotactile stimulation. Although vibrotactile stimulation needs long time of 4–7 years as effective recovery, hand massage may have more effect with a repetition of day after day

A case of Cushing’s syndrome detected by repeated fragility fractures

A ３８-year-old woman had suffered from an avulsion fracture of the left cuboid bone, a rib fracture, a fatigue fracture of the left second metatarsal bone and a pubic fracture within the last ４ years. She also realized that her face was getting rounded and became aware of edema on extremities. She had repeated fragile fractures before menopause and was referred to our department on suspicion of secondary osteoporosis. The patients showed physical signs of moon face, central obesity, and abdominal violaceous striae. Cushing’s syndrome was suspected, therefore confirmatory studies were performed. Circadian variation of cortisol : serum cortisol１９．３μg／dL（at７：００）, ２１．４μg／dL（at２３：００）, urinary free cortisol :２４７．４μg／２４h, ACTH :２．５pg／mL. Low-dose（１mg） dexamethasone did not suppress cortisol level（１８．９μg/dL）. Based on these findings, we diagnosed as Cushing’s syndrome and glucocorticoid excess seemed to be the cause of secondary osteoporosis. Abdominal CT identified a ２．７ cm tumor in the left adrenal gland, and in-phase T１‐weighted MRI showed decreased signal compared to out-phase, suggesting an adrenocortical adenoma. She underwent laparoscopic left adrenalectomy. Postoperative fasting serum cortisol decreased to２．２ μg/dL, and glucocorticoid replacement therapy was started. It is necessary to find out any secondary causes for premenopausal women with fragility fractures. It is well known that endocrine disorders including Cushing’s syndrome are the most frequent associated diseases in patients with premenopausal osteoporosis. Cushing’s syndrome should be considered as a causative disease in premenopausal women with osteoporosis

Topoisomerase II, scaffold component, promotes chromatin compaction in vitro in a linker-histone H1-dependent manner

TopoisomeraseII (Topo II) is a major component of chromosomal scaffolds and essential for mitotic chromosome condensation, but the mechanism of this action remains unknown. Here, we used an in vitro chromatin reconstitution system in combination with atomic force and fluorescence microscopic analyses to determine how Topo II affects chromosomal structure. Topo II bound to bare DNA and clamped the two DNA strands together, even in the absence of ATP. In addition, Topo II promoted chromatin compaction in a manner dependent on histone H1 but independent of ATP. Histone H1-induced 30-nm chromatin fibers were converted into a large complex by Topo II. Fluorescence microscopic analysis of the Brownian motion of chromatin stained with 4′,6-diamidino-2-phenylindole showed that the reconstituted chromatin became larger following the addition of Topo II in the presence but not the absence of histone H1. Based on these findings, we propose that chromatin packing is triggered by histone H1-dependent, Topo II-mediated clamping of DNA strands

High-resolution seismic reflection profiling across the Sone Hills fault zone, central Japan

The Sone fault is a south dipping active reverse fault, trending WNW-ESE and bounding the southern end of the Kofu basin. This fault is located between the Kofu basin and Sone hills, and has displaced several river terraces. To reveal the subsurface geometry of the Sone fault, highresolution shallow seismic profiling was performed along the 2.8-km-long Makado and 0.8-km-long Ubaguchi seismic lines. On the Unagushi section, a south dipping fault surface is clearly recognized by the discontinuity between horizontal reflectors in the north and the domain showing a chaotic pattern of reflections. On the Makado section, the south dipping Sone fault is identified between the horizontal reflectors at the basin-side and dipping reflectors at the hill-side. On both seismic lines, the fault surface dips 30 degrees southward. The trace of The Sone fault is located along the present riverbed of R. Fuefuki, some hundred meters basin-ward shift from the trace estimated from tectonic geomorphology

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target