38 research outputs found
CRYSTAL GROWTH OF RARE EARTH COMPOUNDS IN CLOSED SYSTEM
Remarkable improvements have been made on the crystal growth of rare earth pnictides and chalchogenides by the development of new growth technique and the construction of several new equipments for the crystal growth such as electron beam welding system of tungsten crucible provided with large glove box and vacuum HF furnace. This system has really worked on obtaining excellent quality of single crystals and made easier to explore unknown materials of rare earth compounds. Interesting and attractive physical properties of these compounds were obtained from the crystals produced by this system and contributed to extend a new scope of the heavy Fermion physics
Complications of Evans' syndrome in an infant with hereditary spherocytosis: a case report
Hereditary spherocytosis (HS) is a genetic disorder of the red blood cell membrane clinically characterized by anemia, jaundice and splenomegaly. Evans' syndrome is a clinical syndrome characterized by autoimmune hemolytic anemia (AIHA) accompanied by immune thrombocytopenic purpura (ITP). It results from a malfunction of the immune system that produces multiple autoantibodies targeting at least red blood cells and platelets. HS and Evans' syndrome have different mechanisms of pathophysiology one another. We reported the quite rare case of an infant who had these diseases concurrently. Possible explanations of the unexpected complication are discussed
Cardiomyocyte Formation by Skeletal Muscle-Derived Multi-Myogenic Stem Cells after Transplantation into Infarcted Myocardium
BACKGROUND: Cellular cardiomyoplasty for myocardial infarction has been developed using various cell types. However, complete differentiation and/or trans-differentiation into cardiomyocytes have never occurred in these transplant studies, whereas functional contributions were reported. METHODS AND RESULTS: Skeletal muscle interstitium-derived CD34(+)/CD45(-) (Sk-34) cells were purified from green fluorescent protein transgenic mice by flowcytometory. Cardiac differentiation of Sk-34 cells was examined by in vitro clonal culture and co-culture with embryonic cardiomyocytes, and in vivo transplantation into a nude rat myocardial infarction (MI) model (left ventricle). Lower relative expression of cardiomyogenic transcription factors, such as GATA-4, Nkx2-5, Isl-1, Mef2 and Hand2, was seen in clonal cell culture. However, vigorous expression of these factors was seen on co-culture with embryonic cardiomyocytes, together with formation of gap-junctions and synchronous contraction following sphere-like colony formation. At 4 weeks after transplantation of freshly isolated Sk-34 cells, donor cells exhibited typical cardiomyocyte structure with formation of gap-junctions, as well as intercalated discs and desmosomes, between donor and recipient and/or donor and donor cells. Fluorescence in situ hybridization (FISH) analysis detecting the rat and mouse genomic DNA and immunoelectron microscopy using anti-GFP revealed donor-derived cells. Transplanted Sk-34 cells were incorporated into infarcted portions of recipient muscles and contributed to cardiac reconstitution. Significant improvement in left ventricular function, as evaluated by transthoracic echocardiography and micro-tip conductance catheter, was also observed. CONCLUSIONS AND SIGNIFICANCE: Skeletal muscle-derived multipotent Sk-34 cells that can give rise to skeletal and smooth muscle cells as reported previously, also give rise to cardiac muscle cells as multi-myogenic stem cells, and thus are a potential source for practical cellular cardiomyoplasty
PlGF Repairs Myocardial Ischemia through Mechanisms of Angiogenesis, Cardioprotection and Recruitment of Myo-Angiogenic Competent Marrow Progenitors
Despite preclinical success in regenerating and revascularizing the infarcted heart using angiogenic growth factors or bone marrow (BM) cells, recent clinical trials have revealed less benefit from these therapies than expected.We explored the therapeutic potential of myocardial gene therapy of placental growth factor (PlGF), a VEGF-related angiogenic growth factor, with progenitor-mobilizing activity.Myocardial PlGF gene therapy improves cardiac performance after myocardial infarction, by inducing cardiac repair and reparative myoangiogenesis, via upregulation of paracrine anti-apoptotic and angiogenic factors. In addition, PlGF therapy stimulated Sca-1(+)/Lin(-) (SL) BM progenitor proliferation, enhanced their mobilization into peripheral blood, and promoted their recruitment into the peri-infarct borders. Moreover, PlGF enhanced endothelial progenitor colony formation of BM-derived SL cells, and induced a phenotypic switch of BM-SL cells, recruited in the infarct, to the endothelial, smooth muscle and cardiomyocyte lineage.Such pleiotropic effects of PlGF on cardiac repair and regeneration offer novel opportunities in the treatment of ischemic heart disease
The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force
「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
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
Effects of Bit Shape of Electroplated Diamond Tool Used for Drilling Small Diameter Holes in Glass Plate on Machining Fluid Flow and Chip Discharge
Our laboratory has been exploring the development of tools for drilling holes in glass plates, and the drilling techniques to be adopted for it. A devised tool shape that could prevent the occurrence of cracks at the exit holes achieved high quality through hole drilling of 100 holes or more using only the drilling cycle. However, crack-free drilling beyond this number of holes cannot be performed. This is due to the adhesion of the residual chip on the tool surface when the number of holes increases. Therefore, further improvement of chip discharge is needed to achieve crack-free drilling. In this report, we consider that chip discharge results from the flow of the machining fluid. To investigate the cause of chip discharge, we analyzed the flow of the machining fluid in the hole using computational fluid dynamics and the supposed chip discharge conditions. The results obtained in this study are summarized as follows. (1) In the case of a cylindrical tool, the Z-axis directional flow of the machining fluid did not occur in the hole. This is because the tool does not have bumps to agitate the fluid on the side, and the gap between the tool and the inner surface of the hole is narrow. (2) The plate side widened the gap between the tool and inner surface of the hole. Therefore, the fluid was likely to flow in the Z-axis direction in the hole. (3) For the tool with the plane side bit, the flow entered the hole from one plane side and exited the hole from the other plane side. (4) When the tool end is spherical, the Z-axis directional flow of the fluid occurs at the tool end. (5) The fluid flow of the devised tool weakened as the drilling depth increased. To improve the chip discharge performance of the designed tool, the Z-axis directional flow of the machining fluid must occur in an area deeper than 2 mm
Effects of Bit Shape of Electroplated Diamond Tool Used for Drilling Small Diameter Holes in Glass Plate on Machining Fluid Flow and Chip Discharge
Our laboratory has been exploring the development of tools for drilling holes in glass plates, and the drilling techniques to be adopted for it. A devised tool shape that could prevent the occurrence of cracks at the exit holes achieved high quality through hole drilling of 100 holes or more using only the drilling cycle. However, crack-free drilling beyond this number of holes cannot be performed. This is due to the adhesion of the residual chip on the tool surface when the number of holes increases. Therefore, further improvement of chip discharge is needed to achieve crack-free drilling. In this report, we consider that chip discharge results from the flow of the machining fluid. To investigate the cause of chip discharge, we analyzed the flow of the machining fluid in the hole using computational fluid dynamics and the supposed chip discharge conditions. The results obtained in this study are summarized as follows. (1) In the case of a cylindrical tool, the Z-axis directional flow of the machining fluid did not occur in the hole. This is because the tool does not have bumps to agitate the fluid on the side, and the gap between the tool and the inner surface of the hole is narrow. (2) The plate side widened the gap between the tool and inner surface of the hole. Therefore, the fluid was likely to flow in the Z-axis direction in the hole. (3) For the tool with the plane side bit, the flow entered the hole from one plane side and exited the hole from the other plane side. (4) When the tool end is spherical, the Z-axis directional flow of the fluid occurs at the tool end. (5) The fluid flow of the devised tool weakened as the drilling depth increased. To improve the chip discharge performance of the designed tool, the Z-axis directional flow of the machining fluid must occur in an area deeper than 2 mm