Phosphatidyl inositol-phospholipase C in squid photoreceptor membrane is activated by stable metarhodopsin via GTP-binding protein, Gq

AbstractPhosphatidyl inositol-phospholipase C (PI-PLC) in squid retina was studied by immunoblotting and its activites were determined using [3H]phosphatidyl inositol bisphosphate ([3H]PIP2) as substrate. PI-PLC activity was found mostly in soluble fraction when the retina homogenate was treated with 400 mM KCl, but was associated with rhabdomal membranes under low salt conditions (20 mM Hepes). A protein with apparent molecular mass of 130 kD was recognized by an antibody against PLCβ4/norp A in both 400 mM KCl soluble and rhabdomal membrane fractions. A 42 kD protein recognized by antibody against the C-terminus of Gqα was also present in these two fractions. GTPγS stimulated only the PI-PLC activity associated with membrane and was magnesium dependent. PI-PLC activity was found to be (i) highly dependent upon calcium concentrations, (ii) enhanced by GTP but not by other nucleotides, and (iii) significantly stimulated by light at lower concentrations of GTPγS. The stimulation by light was still observed when irradiated membrane was incubated at 10°C for 10 min and then mixed with GTPγS. These results suggest that stable metarhodopsin stimulates a PLCβ4/norp A-like enzyme via a G-protein, Gq

<ORIGINAL>Combined Effects of Erbium : YAG laser and Fluoride Application on Acid Resistance of Tooth dentin in vitro

This study examined the inhibition of dentin demineralization in initial caries with Er : YAG laser irradiation only and laser irradiation combined with fluoride application. Dentin blocks were prepared from the roots of bovine incisors and pretreated with one of the following five procedures : A) untreated, B) Er : YAG laser irradiation for 5min at 50mJ/pulse, C) APF gel application for 5min, D) Er : YAG laser followed by APF application for 5min,and E) APF treatment for 5min followed by Er : YAG laser irradiation. Subsequently the samples were demineralized in a 0.1M lactic acid gel (pH5.0) containing 6wt% CMC at 37℃ for 2 weeks. The mineral distributions in the dentin surfaces were assessed quantitatively by transversal microradiography (TMR) and videodensitometry. The mineral parameter values were not significantly different for samples with and without laser treatment at p=0.05, as tested by paired t-tests. The present results suggest that the progress of demineralization in dentin lesions is not effectively inhibited by the single treatment with laser irradiation. Combined Er : YAG laser and APF treated samples had the highest acid resistance with significantly lower lesion depth (ld) and mineral loss (ΔZ) values lower even than the APF treated samples

ALMA ACA detection of submillimeter emission associated with the west hot spot of the radio galaxy Pictor A

In order to investigate the far-infrared excess detected from the west hot spot of the radio galaxy Pictor A with the Herschel observatory, a submillimeter photometry is performed with the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array at Band 8 with the reference frequency of 405 GHz. A submillimeter source is discovered at the radio peak of the hot spot. Because the 405 GHz flux density of the source, $80.7\pm3.1$ mJy, agrees with the extrapolation of the synchrotron radio spectrum, the far-infrared excess is suggested to exhibit no major contribution at the ACA band. In contrast, by subtracting the power-law spectrum tightly constrained by the radio and ACA data, the significance of the excess in the Herschel band is well confirmed. No diffuse submillimeter emission is detected within the ACA field of view, and thus, the excess is ascribed to the west hot spot itself. In comparison to the previous estimate based on the Herschel data, the relative contribution of the far-infrared excess is reduced by a factor of $\sim 1.5$. The spectrum of the excess below the far-infrared band is determined to be harder than that of the diffusive shock acceleration. This strengthens the previous interpretation that the excess originates via the magnetic turbulence in the substructures within the hot spot. The ACA data are utilized to evaluate the magnetic field strength of the excess and of diffuse radio structure associated to the hot spot.Comment: 10 pages,4 figures, 3 tables, accepted for Ap

Utility of commercial high‐resolution satellite imagery for monitoring general flowering in Sarawak, Borneo

General flowering (GF), irregular synchronous mass flowering of multiple tree species across multiple families, is a unique biological phenomenon of the mixed lowland dipterocarp forest in Southeast Asia. Characterizing the spatial extent and temporal dynamics of GF is essential for an improved understanding of climate–vegetation interactions and the potential climate change impact on this species-rich rainforest. We investigated the utility of newly available high-temporal (daily) and high-spatial (3–4 m) resolution remote sensing by the PlanetScope commercial satellite constellation for detecting flowering trees in a dipterocarp rainforest at Lambir Hills National Park, Sarawak, Malaysia. Our study was focused on the latest GF event known to have occurred in the region in the year 2019. PlanetScope successfully acquired 13 clear-sky or minimally cloud-contaminated scenes over the park during a study period of January 1, 2019 to August 31, 2019 encompassing the 2019 GF event. In situ phenology observations verified that the PlanetScope images detected the flowering crowns of tree species that turned into white or orange. This multitemporal image dataset also captured the flowering peak and species differences. The correlation coefficients between the multitemporal image signatures and in situ phenology observations were moderate to very strong (0.52–0.85). The results indicated that the 2019 GF event was a whole-park phenomenon with the flowering peak in May. This study reports the first successful satellite-based observations of a GF event and suggests the possibility of regional-scale characterization of species-level phenology in the dipterocarp forest, key information for biodiversity conservation in Southeast Asia

Risk for atrial fibrillation in patients with hypertrophic cardiomyopathy: Association with insulin resistance

SummaryBackgroundWe undertook a cross-sectional study to test the hypothesis that patients with hypertrophic cardiomyopathy (HCM) who have impaired left ventricular (LV) diastolic function are insulin resistant. We also evaluated the relation between the development of atrial fibrillation (AF) and insulin resistance (IR) in patients with HCM.Methods and resultsEighty-eight patients with HCM (71 men, 17 women) were enrolled in the study. IR was estimated using the homeostasis model assessment (HOMA) index. Echocardiographically determined left atrial (LA) dimension was measured as a marker of LA size. The ratio of trasmitral early LV filling velocity to early diastolic mitral annulus velocity (E/e′) was also measured as a marker of LV diastolic function. Twenty-seven patients (31%) had IR. Multivariate logistic regression analyses showed that independent determinants of AF were increased LA size [odds ratio (OR) 3.5, 95% confidence interval (CI) 1.2–9.8] and impaired LV diastolic function [OR 4.6, 95% CI 1.6–12.8]. The strongest determinant of LA size was the HOMA index (p=0.0005). Similarly, the HOMA index (p=0.0019) was an independent determinant of LV diastolic function.ConclusionIR is highly prevalent among non-diabetic patients with HCM. A possible mechanism by which IR affects the development of AF is mediated through its association with increased LA size or impaired LV diastolic function. IR may be an important underlying mechanism for the genesis of AF in HCM

Chemogenetic sensory fMRI reveals behaviorally relevant bidirectional changes in primate somatosensory network

手と足の感覚は、実は脳の中でつながっていた --脳障害による活動変化の広がりを見ることで常識を覆す発見、脳機能・疾患機序の理解へ前進--. 京都大学プレスリリース. 2021-10-21.Concurrent genetic neuromodulation and functional magnetic resonance imaging (fMRI) in primates has provided a valuable opportunity to assess the modified brain-wide operation in the resting state. However, its application to link the network operation with behavior still remains challenging. Here, we combined chemogenetic silencing of the primary somatosensory cortex (SI) with tactile fMRI and related behaviors in macaques. Focal chemogenetic silencing of functionally identified SI hand region impaired grasping behavior. The same silencing also attenuated hand stimulation-evoked fMRI signal at both the local silencing site and the anatomically and/or functionally connected downstream grasping network, suggesting altered network operation underlying the induced behavioral impairment. Furthermore, the hand region silencing unexpectedly disinhibited foot representation with accompanying behavioral hypersensitization. These results demonstrate that focal chemogenetic silencing with sensory fMRI in macaques unveils bidirectional network changes to generate multifaceted behavioral impairments, thereby opening a pivotal window toward elucidating the causal network operation underpinning higher brain functions in primates

High-pressure synthesis, crystal structure determination, and a Ca substitution study of the metallic rhodium oxide NaRh2O4

The sodium rhodate NaRh2O4 was synthesized for the first time and characterized by neutron and X-ray diffraction studies and measurements of magnetic susceptibility, specific heat, electrical resistivity, and the Seebeck coefficient. NaRh2O4 crystallizes in the CaFe2O4-type structure, which is comprised of a characteristic RhO6 octahedral network. The compound is metallic in nature, probably reflecting the 1:1 mixed valence character of Rh(III) and Rh(IV) in the network. For further studies of the compound, the Rh valence was varied significantly by means of an aliovalent substitution: the full-range solid solution between NaRh2O4 and CaRh2O 4 was achieved and characterized as well. The metallic state was dramatically altered, and a peculiar magnetism developed in the low Na concentration range

細菌の接種によって誘導されるアコヤガイ中の抗菌性タンパク質の探索

The aim of this research was to characterize immune-related antibacterial substances from pearl oyster Pinctada fucata induced by bacterial invasion. Bacteria inoculation was performed by injecting 0.1 ml of 1.0 × 1012 colony-forming units/ml Vibrio parahaemolyticus into adductor muscle. Acidic extracts were prepared with 0.1% trifluoroacetic acid from different tissues after 8 h of injection, and antibacterial activity against V. parahaemolyticus was determined via the microdilution broth method. The acidic extracts from gills of inoculated oysters (AEg) showed stronger antibacterial activity than those from non-inoculated ones. Based on this result, antibacterial proteins were purified from AEg via two-step gel filtration chromatography, followed by high-performance liquid chromatography using a TSkgel G3000 column. Protein components were analyzed by both sodium dodecyl sulfate and native polyacrylamide gel electrophoresis. As a result, two antibacterial proteins, APg-1 (with a molecular mass of approximately 210 kDa) and APg-2 (of approximately 30 kDa), were obtained from AEg. Matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis and partial amino acid sequences revealed that these proteins might be novel antibacterial proteins. These results indicate that antibacterial proteins are potentially upregulated in the gill of pearl oysters or released therefrom for defense against bacterial invasion.本研究で対象とするアコヤガイは，日本において重要な養殖真珠の母貝として用いられる二枚貝である。腸炎ビブリオをアコヤガイ閉殻筋に直接接種したところ，鰓から得られた酸抽出物に，非接種の対照よりも強い抗菌活性を示す成分が存在することを見出した。酸抽出物はグラム陽性菌および陰性菌に抗菌活性を示し，とくにビブリオ属に強く作用した。鰓より2種の抗菌タンパク質APg-1（分子量約210 kDa）およびAPg-2（分子量約30 kDa）を分離し，これらはMALDI-TOF MS分析により，新規の抗菌タンパク質である可能性が推察された