58 research outputs found

    Histological development of stapes footplate in human embryos.

    Get PDF
    Normal development of the human stapes footplate was investigated in serial sections by light microscopy. Materials were obtained from 35 Japanese embryos from the 6th to 32nd week of embryonal age. Eighteen embryos up to 16 weeks of age (3.5mm to 105mm in crown-rump length) were examined, focusing particularly on the lamina stapedialis of the otic capsule. The present study showed that primordial formation of the lamina stapedialis appeared in 16mm embryo and that the lamina was completely formed and fused to the base of the annular stapes in a 35mm embryo. In a 50mm embryo, the adult form of stapes was found with a rim and annular ligament. The results, therefore, seemed to essentially agree with the theory of dual origin and development of the footplate proposed by Cauldwell and Anson, and teratogenic agents might affect any stage of the process producing anomalies,</p

    Effects of Hydrostatic Pressure and Uniaxial Strain on Spin-Peierls Transition in an Organic Radical Magnet, BBDTA·InCl4

    Get PDF
    We investigated the effects of hydrostatic pressure and uniaxial strain on the spin-Peierls (SP) transition of an organic radical magnet, benzo[1,2-d:4,5-d\u27]bis[1,3,2]dithiazole(BBDTA)·InCl 4 . It has a one-dimensional coordination polymer structure along its c -axis and its SP transition occurs at 108 K. The SP transition temperature T SP decreased to 99 K at a hydrostatic pressure of 10 kbar, while it increased to 132 K at a uniaxial strain along the c -axis of 8 kbar. The pressure dependences of T SP under these two conditions were discussed by evaluating two parameters, namely, the intrachain interaction 2 J / k B and the effective spin–lattice coupling parameter η, that are related to T SP by the equation T SP =1.6η J / k B . Under ambient pressure, the a - and c -axes of this material shortened monotonically with decreasing temperature, while the b -axis elongated below T SP . In this study, we found the correlation between η and the change in the lattice constant b . 2 J / k B increased with increasing hydrostatic pressure and uniaxial strain, suggesting that the contraction along the c -axis does not depend on the manner of pressurization. From the evaluation of η, the observed variation in T SP is explained by the difference between the changes in b under the two pressurization conditions

    Midgut-derived neuropeptide F controls germline stem cell proliferation in a mating-dependent manner

    Get PDF
    Stem cell maintenance is established by neighboring niche cells that promote stem cell self-renewal. However, it is poorly understood how stem cell activity is regulated by systemic, tissue-extrinsic signals in response to environmental cues and changes in physiological status. Here, we show that neuropeptide F (NPF) signaling plays an important role in the pathway regulating mating-induced germline stem cell (GSC) proliferation in the fruit fly Drosophila melanogaster. NPF expressed in enteroendocrine cells (EECs) of the midgut is released in response to the seminal-fluid protein sex peptide (SP) upon mating. This midgut-derived NPF controls mating-induced GSC proliferation via ovarian NPF receptor (NPFR) activity, which modulates bone morphogenetic protein (BMP) signaling levels in GSCs. Our study provides a molecular mechanism that describes how a gut-derived systemic factor couples stem cell behavior to physiological status, such as mating, through interorgan communication

    Semiconducting Electronic Structure of the Ferromagnetic Spinel HgCr2Se4\mathbf{Hg}\mathbf{Cr}_2\mathbf{Se}_4 Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy

    Full text link
    We study the electronic structure of the ferromagnetic spinel HgCr2Se4\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4 by soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) and first-principles calculations. While a theoretical study has predicted that this material is a magnetic Weyl semimetal, SX-ARPES measurements give direct evidence for a semiconducting state in the ferromagnetic phase. Band calculations based on the density functional theory with hybrid functionals reproduce the experimentally determined band gap value, and the calculated band dispersion matches well with ARPES experiments. We conclude that the theoretical prediction of a Weyl semimetal state in HgCr2Se4\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4 underestimates the band gap, and this material is a ferromagnetic semiconductor.Comment: 6+13 pages, 4+13 figure

    Lower In-Hospital Mortality With Beta-Blocker Use at Admission in Patients With Acute Decompensated Heart Failure

    Get PDF
    [Background] It remains unclear whether beta‐blocker use at hospital admission is associated with better in‐hospital outcomes in patients with acute decompensated heart failure. [Methods and Results] We evaluated the factors independently associated with beta‐blocker use at admission, and the effect of beta‐blocker use at admission on in‐hospital mortality in 3817 patients with acute decompensated heart failure enrolled in the Kyoto Congestive Heart Failure registry. There were 1512 patients (39.7%) receiving, and 2305 patients (60.3%) not receiving beta‐blockers at admission for the index acute decompensated heart failure hospitalization. Factors independently associated with beta‐blocker use at admission were previous heart failure hospitalization, history of myocardial infarction, atrial fibrillation, cardiomyopathy, and estimated glomerular filtration rate <30 mL/min per 1.73 m2. Factors independently associated with no beta‐blocker use were asthma, chronic obstructive pulmonary disease, lower body mass index, dementia, older age, and left ventricular ejection fraction <40%. Patients on beta‐blockers had significantly lower in‐hospital mortality rates (4.4% versus 7.6%, P<0.001). Even after adjusting for confounders, beta‐blocker use at admission remained significantly associated with lower in‐hospital mortality risk (odds ratio, 0.41; 95% CI, 0.27–0.60, P<0.001). Furthermore, beta‐blocker use at admission was significantly associated with both lower cardiovascular mortality risk and lower noncardiovascular mortality risk. The association of beta‐blocker use with lower in‐hospital mortality risk was relatively more prominent in patients receiving high dose beta‐blockers. The magnitude of the effect of beta‐blocker use was greater in patients with previous heart failure hospitalization than in patients without (P for interaction 0.04). [Conclusions] Beta‐blocker use at admission was associated with lower in‐hospital mortality in patients with acute decompensated heart failure

    LSD1-mediated repression of GFI1 super-enhancer plays an essential role in erythroleukemia.

    Get PDF
    Super-enhancers (SEs) consist of enhancer clusters with abundant binding of transcription factors (TFs) and cofactors. LSD1 is a histone modifier that eliminates SE activity. However, whether SE suppression by LSD1 is associated with leukemogenesis remains unknown. In erythro-megakaryocyte lineage leukemia cells, activation of the SE of GFI1 (GFI1-SE) is related to induction of myeloid differentiation by LSD1 inhibitors NCD38 and NCD25 and to their antileukemia effect. Although functional TF-motifs were concentrated in an evolutionally conserved area, NCD38 barely induced additional TF recruitment. Instead, the transcription cofactors including LSD1, CoREST, HDAC1, and HDAC2 were evicted from GFI1-SE. Deletion of GFI1-SE impaired induction of myeloid differentiation by NCD38 and NCD25 in erythroleukemia cells. Gene set enrichment analysis revealed that the GFI1-SE deletion impaired NCD38-induced programs related to granulocyte differentiation and the CEBPA network, but restored NCD38-suppressed programs related to erythroid development, GATA1 targets, and acute myeloid leukemia (AML) clusters including FAB subtype M6 and AML with myelodysplastic syndrome-related chromosomal abnormalities. Ontologies of genes whose expression changes by NCD38 were canceled due to the GFI1-SE deletion showed enrichment in AML and neutropenia signatures. Collectively, our data suggest that sustainable repression of GFI1-SE by LSD1 is essential for sustenance of erythroleukemia cells
    corecore