Quantitative Threshold Determination of Auditory Brainstem Responses in Mouse Models

The auditory brainstem response (ABR) is a scalp recording of potentials produced by sound stimulation, and is commonly used as an indicator of auditory function. However, the ABR threshold, which is the lowest audible sound pressure, cannot be objectively determined since it is determined visually using a measurer, and this has been a problem for several decades. Although various algorithms have been developed to objectively determine ABR thresholds, they remain lacking in terms of accuracy, efficiency, and convenience. Accordingly, we proposed an improved algorithm based on the mutual covariance at adjacent sound pressure levels. An ideal ABR waveform with clearly defined waves I–V was created; moreover, using this waveform as a standard template, the experimentally obtained ABR waveform was inspected for disturbances based on mutual covariance. The ABR testing was repeated if the value was below the established cross-covariance reference value. Our proposed method allowed more efficient objective determination of ABR thresholds and a smaller burden on experimental animals.Tanaka K., Ohara S., Matsuzaka T., et al. Quantitative Threshold Determination of Auditory Brainstem Responses in Mouse Models. International Journal of Molecular Sciences 24, 11393 (2023); https://doi.org/10.3390/ijms241411393

Spectral dependence of photoinduced spin precession in DyFeO3

Spin precession was nonthermally induced by an ultrashort laser pulse in orthoferrite DyFeO3 with a pump-probe technique. Both circularly and linearly polarized pulses led to spin precessions; these phenomena are interpreted as the inverse Faraday effect and the inverse Cotton-Mouton effect, respectively. For both cases, the same mode of spin precession was excited; the precession frequencies and polarization were the same, but the phases of oscillations were different. We have shown theoretically and experimentally that the analysis of phases can distinguish between these two mechanisms. We have demonstrated experimentally that in the visible region, the inverse Faraday effect was dominant, whereas the inverse Cotton-Mouton effect became relatively prominent in the near-infrared region.Comment: 27 pages, 8 figure

トウイン ニオケル ダイタイ ヘルニア シュジュツ 26ショウレイ ノ リンショウテキ ケントウ

We performed this study to investigate the differences in clinical features between incarcerated femoral hernias and non-incarcerated cases. We operated on 26 patients with a femoral hernia from April 1989 to December 1998. Twenty-four patients were female and two were male. Thir mean age at the time of operation was 68.2±15.4 years, and those older than 60 years were remarkably high. All females had a history of abortion more than twice. Eighteen of 26 (69.2%) hemoral hernias occurred on the right side, 7 on the left, and 1 on both sides. Those with an incarcerated hernia were 46.2% (12/26). Almost all patients without incarceration had only femoral tumors or swelling. On the contrary, a large number of the patients with an incarcerated hernia complained of abdominal or femoral pain, suggesting a hernial strangulation. Significant increases in white blood cell counts were recognized in the incarcerated cases compared to those without incarceration (9158.3± 2155.3 vs 6602.9±1049.5/mm3, respectively;P=0.0001). Additionally, the postoperative hospitalization periods of the patients with incarcerations were remarkably prolonged compared to those without an incarceration. According to the contents of the hernia in the 12 patients with incarcerations, we detected the small bowel in 9 and the grater omentum in 3. Six of 9 patients with an incarcerated small bowel had necrotic complications of strangulated small bowel. However, there was no clinical difference compared to the other 6 patients without a necrotic small bowel. In conculusion, we should recognize the possibility of femoral hernias in the treatment of patients complaining of a tumor or pain in the femoral triangle

Hypermineralization of Hearing-Related Bones by a Specific Osteoblast Subtype

Auditory ossicles in the middle ear and bony labyrinth of the inner ear are highly mineralized in adult mammals. Cellular mechanisms underlying formation of dense bone during development are unknown. Here, we found that osteoblast-like cells synthesizing highly mineralized hearing-related bones produce both type I and type II collagens as the bone matrix, while conventional osteoblasts and chondrocytes primarily produce type I and type II collagens, respectively. Furthermore, these osteoblast-like cells were not labeled in a “conventional osteoblast”-specific green fluorescent protein (GFP) mouse line. Type II collagen-producing osteoblast-like cells were not chondrocytes as they express osteocalcin, localize along alizarin-labeled osteoid, and form osteocyte lacunae and canaliculi, as do conventional osteoblasts. Auditory ossicles and the bony labyrinth exhibit not only higher bone matrix mineralization but also a higher degree of apatite orientation than do long bones. Therefore, we conclude that these type II collagen-producing hypermineralizing osteoblasts (termed here auditory osteoblasts) represent a new osteoblast subtype. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).Kuroda Y., Kawaai K., Hatano N., et al. Hypermineralization of Hearing-Related Bones by a Specific Osteoblast Subtype. Journal of Bone and Mineral Research, 36, 8, 1535. https://doi.org/10.1002/jbmr.4320

Clinical study of strangulation obstruction of the small bowel

Early diagnosis of strangulation obstruction is very important for surgeons because delayed diagnosis often leads to severe complications. Thirty patients underwent an operation because of small bowel obstruction between April, 1993 and December, 1999. In the present study, we examined the differences in clinical findings between simple obstruction and strangulation obstruction. In addition, we examined the manifestation of systemic inflammatory response syndrome (SIRS) and whether it is useful for early diagnosis of strangulation obstruction, and whether it is correlated with the severity of ischemia due to strangulation. Tenderness was examined in all patients and signs such as abdominal irritation were detected more often in patients with strangulation obstruction than in the patients with simple obstruction. According to SIRS, the large number of the patients with strangulation obstruction showed SIRS before operation and the manifestation of SIRS correlated well with the length of the necrosis in the strangulated small bowel. We recognized the importance of anamnesis and clinical findings in examinations of small bowel obstruction, furthermore, it was suggested that SIRS should be the warning sign for strangulation obstruction

Striatal TRPV1 activation by acetaminophen ameliorates dopamine D2 receptor antagonists-induced orofacial dyskinesia

ジスキネジア新治療法の発見 --副作用を減らす併用薬から新しい創薬標的へ--. 京都大学プレスリリース. 2021-04-16.Antipsychotics often cause tardive dyskinesia, an adverse symptom of involuntary hyperkinetic movements. Analysis of the U.S. Food and Drug Administration Adverse Event Reporting System and JMDC insurance claims revealed that acetaminophen prevents the dyskinesia induced by dopamine D₂ receptor antagonists. In vivo experiments further showed that a 21-day treatment with haloperidol increased the number of vacuous chewing movements (VCMs) in rats, an effect that was inhibited by oral acetaminophen treatment or intracerebroventricular injection of N-(4-hydroxyphenyl)-arachidonylamide (AM404), an acetaminophen metabolite that acts as an activator of the transient receptor potential vanilloid 1 (TRPV1). In mice, haloperidol-induced VCMs were also mitigated by treatment with AM404 applied to the dorsal striatum, but not in TRPV1-deficient mice. Acetaminophen prevented the haloperidol-induced decrease in the number of c-Fos⁺/preproenkephalin⁺ striatal neurons in wild-type mice but not in TRPV1-deficient mice. Finally, chemogenetic stimulation of indirect-pathway medium spiny neurons in the dorsal striatum decreased haloperidol-induced VCMs. These results suggest that acetaminophen activates the indirect pathway neurons by activating TRPV1 channels via AM404

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

We study the electronic structure of the ferromagnetic spinel $\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4$ 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 $\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4$ underestimates the band gap, and this material is a ferromagnetic semiconductor.Comment: 6+13 pages, 4+13 figure

Understanding the Role of Biogenic Magnetite in Geomagnetic Paleointensity Recording: Insights From Ontong Java Plateau Sediments

金沢大学理工研究域地球社会基盤学系Marine sediments can preserve continuous paleomagnetic intensity records. Different magnetic minerals may acquire remanent magnetizations differently, so that compositional variations of magnetic mineral assemblages in sediments may hinder extraction of reliable relative paleointensity (RPI) records. To better understand this issue, we conducted a paleo- and rock magnetic study of a sediment core from the Ontong Java Plateau, western equatorial Pacific Ocean. RPI estimated by normalizing natural remanent magnetization (NRM) with anhysteretic remanent magnetization (ARM) decreases downcore with an inverse correlation with the ratio of ARM susceptibility to saturation isothermal remanent magnetization. This relationship indicates that the RPI signal weakens as the proportion of biogenic magnetite increases. The NRM–ARM demagnetization diagrams obtained have concave-down curvature. These observations indicate that the RPI recording efficiency of the biogenic component is lower than that of the terrigenous component if we assume that the magnetizations of the high- and low-coercivity windows are carried dominantly by biogenic and terrigenous components, respectively. This assumption is supported by first-order reversal curve measurements, transmission electron microscope observations, low-temperature measurements, and extraction of silicate-hosted magnetic inclusions from the sediments. Previous studies have suggested that the RPI recording efficiency of biogenic magnetite is higher than that of the terrigenous component, which disagrees with our results. Different concentrations of silicate-hosted magnetic inclusions in different sedimentary environments might explain this contradiction. We conclude that biogenic magnetite contributes to RPI records with lower efficiency than unprotected terrigenous magnetic minerals in the studied sediments. Changing biogenic magnetite proportions distort ARM-normalized RPI estimations. © 2022. American Geophysical Union. All Rights Reserved