A ramsayite-type oxide, Ca2Sn2Al2O9

The title compound, dicalcium nonaoxidodistannate(IV)dialuminate, is the second example which crystallizes in the isotypic structure of a pyroxene silicate, Na2Ti2Si2O9 (ramsayite). ∞ 1[Sn2O8] chains and pyroxene-type ∞ 1[Al2O6] chains are formed along the b axis by sharing O atoms. The Ca atoms are situated in the resulting channels and exhibit a coordination number of 7

Free fatty acid receptors, G protein-coupled receptor 120 and G protein-coupled receptor 40, are essential for oil-induced gastric inhibitory polypeptide secretion

Aims/Introduction: Incretin hormone glucose‐dependent insulinotropic polypeptide/gastric inhibitory polypeptide (GIP) plays a key role in high‐fat diet‐induced obesity and insulin resistance. GIP is strongly secreted from enteroendocrine K cells by oil ingestion. G protein‐coupled receptor (GPR)120 and GPR40 are two major receptors for long chain fatty acids, and are expressed in enteroendocrine K cells. In the present study, we investigated the effect of the two receptors on oil‐induced GIP secretion using GPR120‐ and GPR40‐double knockout (DKO) mice. Materials and Methods: Global knockout mice of GPR120 and GPR40 were crossbred to generate DKO mice. Oral glucose tolerance test and oral corn oil tolerance test were carried out. For analysis of the number of K cells and gene expression in K cells, DKO mice were crossbred with GIP‐green fluorescent protein knock‐in mice in which visualization and isolation of K cells can be achieved. Results: Double knockout mice showed normal glucose‐induced GIP secretion, but no GIP secretion by oil. We then investigated the number of K cells and gene characteristics in K cells isolated from GIP‐green fluorescent protein knock‐in mice. Deficiency of both receptors did not affect the number of K cells in the small intestine or expression of GIP messenger ribonucleic acid in K cells. Furthermore, there was no significant difference in the expression of the genes associated with lipid absorption or GIP secretion in K cells between wild‐type and DKO mice. Conclusions: Oil‐induced GIP secretion is triggered by the two major fatty acid receptors, GPR120 and GPR40, without changing K‐cell number or K‐cell characteristics

An analysis of intestinal morphology and incretin-producing cells using tissue optical clearing and 3-D imaging

Tissue optical clearing permits detailed evaluation of organ three-dimensional (3-D) structure as well as that of individual cells by tissue staining and autofluorescence. In this study, we evaluated intestinal morphology, intestinal epithelial cells (IECs), and enteroendocrine cells, such as incretin-producing cells, in reporter mice by intestinal 3-D imaging. 3-D intestinal imaging of reporter mice using optical tissue clearing enabled us to evaluate both detailed intestinal morphologies and cell numbers, villus length and crypt depth in the same samples. In disease mouse model of lipopolysaccharide (LPS)-injected mice, the results of 3-D imaging using tissue optical clearing in this study was consistent with those of 2-D imaging in previous reports and could added the new data of intestinal morphology. In analysis of incretin-producing cells of reporter mice, we could elucidate the number, the percentage, and the localization of incretin-producing cells in intestine and the difference of those between L cells and K cells. Thus, we established a novel method of intestinal analysis using tissue optical clearing and 3-D imaging. 3-D evaluation of intestine enabled us to clarify not only detailed intestinal morphology but also the precise number and localization of IECs and incretin-producing cells in the same samples

Synergistic effect of sulfonation followed by precipitation of amorphous calcium phosphate on the bone-bonding strength of carbon fiber reinforced polyetheretherketone

Sulfonation and applications of amorphous calcium phosphate are known to make polyetheretherketone (PEEK) bioactive. Sulfonation followed by precipitation of amorphous calcium phosphate (AN-treatment) may provide PEEK with further bone-bonding strength. Herein, we prepared a carbon-fiber-reinforced PEEK (CPEEK) with similar tensile strength to cortical bone and a CPEEK subjected to AN-treatment (CPEEK-AN). The effect of AN-treatment on the bone-bonding strength generated at the interface between the rabbit’s tibia and a base material was investigated using a detaching test at two time-points (4 and 8 weeks). At 4 weeks, the strength of CPEEK-AN was significantly higher than that of CPEEK due to the direct bonding between the interfaces. Between 4 and 8 weeks, the different bone forming processes showed that, with CPEEK-AN, bone consolidation was achieved, thus improving bone-bonding strength. In contrast, with CPEEK, a new bone was absorbed mainly on the interface, leading to poor strength. These observations were supported by an in vitro study, which showed that pre-osteoblast on CPEEK-AN caused earlier maturation and mineralization of the extracellular matrix than on CPEEK. Consequently, AN-treatment, comprising a combination of two efficient treatments, generated a synergetic effect on the bonding strength of CPEEK

Species identification, antifungal susceptibility, and clinical feature association of Aspergillus section Nigri isolates from the lower respiratory tract

Species of Aspergillus section Nigri are generally identified by molecular genetics approaches, whereas in clinical practice, they are classified as A. niger by their morphological characteristics. This study aimed to investigate whether the species of Aspergillus section Nigri isolated from the respiratory tract vary depending on clinical diagnosis. Forty-four Aspergillus section Nigri isolates isolated from the lower respiratory tracts of 43 patients were collected from February 2012 to January 2017 at the National Hospital Organization (NHO) Tokyo National Hospital. Species identification was carried out based on β-tubulin gene analysis. Drug susceptibility tests were performed according to the Clinical and Laboratory Standards Institute (CLSI) M38 3rd edition, and the clinical characteristics were retrospectively reviewed. A. welwitschiae was isolated most frequently, followed by A. tubingensis. More than half of the A. tubingensis isolates exhibited low susceptibility to azoles in contrast to only one A. welwitschiae isolate. Approximately three quarters of the patients from whom A. welwitschiae was isolated were diagnosed with colonization, whereas more than half the patients from whom A. tubingensis was isolated were diagnosed with chronic pulmonary aspergillosis (CPA). More attention needs to be given to the drug choice for patients with CPA with Aspergillus section Nigri infection because A. tubingensis, which was found to be frequently azole-resistant, was the most prevalent in these patients

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide signaling in adipose tissue

GIPR signaling in adipose tissue plays an important role in HFD‐induced insulin resistance and hepatic steatosis in vivo, with no direct effect on fat accumulation, through IL‐6 signalin

Regulation of glucagon-like peptide-1 sensitivity by gut microbiota dysbiosis

Gut microbiota dysbiosis reduces expression of GLP‐1 receptor (GLP‐1R) and neuronal nitric oxide synthase (nNOS) in the enteric nervous system and hampers GLP‐1‐induced nitric oxide (NO) production through a pattern recognition receptor (PRR)‐dependent mechanism, hence preventing activation of the gut–brain–periphery axis for control of insulin secretion and gastric emptying

Control of intestinal stem cell fate: A novel approach to treating diabetes

Targeting L-cell development and enrichment of incretin-secreting cells could potentially evolve as novel, effective therapeutics for diabetes

Mechanisms of fat-induced gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide secretion from K cells

Gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide (GIP) is one of the incretins, which are gastrointestinal hormones released in response to nutrient ingestion and potentiate glucose-stimulated insulin secretion. Single fat ingestion stimulates GIP secretion from enteroendocrine K cells; chronic high-fat diet (HFD) loading enhances GIP secretion and induces obesity in mice in a GIP-dependent manner. However, the mechanisms of GIP secretion from K cells in response to fat ingestion and GIP hypersecretion in HFD-induced obesity are not well understood. We generated GIP-green fluorescent protein knock-in (GIPgfp/+) mice, in which K cells are labeled by enhanced GIP-green fluorescent protein. Microarray analysis of isolated K cells from GIPgfp/+ mice showed that both fatty acid-binding protein 5 and G protein-coupled receptor 120 are highly expressed in K cells. Single oral administration of fat resulted in significant reduction of GIP secretion in both fatty acid-binding protein 5- and G protein-coupled receptor 120-deficient mice, showing that fatty acid-binding protein 5 and G protein-coupled receptor 120 are involved in acute fat-induced GIP secretion. Furthermore, the transcriptional factor, regulatory factor X6 (Rfx6), is highly expressed in K cells. In vitro experiments using the mouse enteroendocrine cell line, STC-1, showed that GIP messenger ribonucleic acid levels are upregulated by Rfx6. Expression levels of Rfx6 messenger ribonucleic acid as well as that of GIP messenger ribonucleic acid were augmented in the K cells of HFD-induced obese mice, in which GIP content in the small intestine is increased compared with that in lean mice fed a control diet. These results suggest that Rfx6 is involved in hypersecretion of GIP in HFD-induced obese conditions by increasing GIP gene expression