153 research outputs found

    Successive phase transitions and phase diagrams of the quasi-two-dimensional triangular antiferromagnet Rb4Mn(MoO4)3

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    Comprehensive experimental studies by magnetic, thermal and neutron measurements have clarified that Rb4Mn(MoO4)3 is a model system of a quasi-2D triangular Heisenberg antiferromagnet with an easy-axis anisotropy, exhibiting successive transitions across an intermediate collinear phase. As a rare case for geometrically frustrated magnetism, quantitative agreement between experiment and theory is found for complete, anisotropic phase diagrams as well as magnetic properties.Comment: 4 pages, 5 figure

    Inspiratory and Expiratory Computed Tomography Imaging Clusters Reflect Functional Characteristics in Chronic Obstructive Pulmonary Disease

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    Purpose: Disease probability measure (DPM) is a useful voxel-wise imaging assessment of gas-trapping and emphysematous lesions in patients with chronic obstructive pulmonary disease (COPD). To elucidate the progression of COPD, we performed a cluster analysis using the following DPM parameters: normal (DPMNormal), gas-trapping (DPMGasTrap), and emphysematous lesions (DPMEmph). Our findings revealed the characteristics of each cluster and the 3-year disease progression using imaging parameters. Patients and methods: Inspiratory and expiratory chest computed tomography (CT) images of 131 patients with COPD were examined, of which 84 were followed up for 3 years. The percentage of low attenuation volume (LAV%) and the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) were quantitatively measured using inspiratory chest CT. A hierarchical cluster analysis was performed using the DPM parameters at baseline. Five clusters were named according to the dominant DPM parameters: normal (NL), normal-GasTrap (NL-GT), GasTrap (GT), GasTrap-Emphysema (GT-EM), and Emphysema (EM). Results: Women were predominantly diagnosed with GT. Forced expiratory volume in 1 s gradually decreased in the following order: NL, NL-GT, GT, GT-EM, and EM. DPMEmph correlated well with LAV%. Four clusters other than NL showed significantly higher values of √Aaw at Pi10 than NL; however, no significant differences were observed among them. In all clusters, DPMEmph increased after 3 years. DPMNormal only increased in the GT cluster. Conclusion: Clusters using DPM parameters may reflect the characteristics of COPD and help understand the pathophysiology of the disease.journal articl

    Androgen receptor and 5α-reductase immunohistochemical profiles in extramammary Paget disease

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    Background Extramammary Paget disease is an uncommon skin tumour occurring mostly in the genitoperineal region. Previous reports have shown frequent expression of androgen receptor, suggesting a tumour-proliferative effect of androgens on Paget cells. Androgen-converting enzymes such as 5α-reductase, which locally produces a bioactive androgen, have recently gained attention in studies of the intratumoral actions of androgens. Objectives We investigated correlations between the androgenic microenvironment and invasiveness in extramammary Paget disease, particularly in terms of sex differences. Methods We examined 58 cases of extramammary Paget disease (32 men, 26 women; 42 noninvasive, 16 invasive) using immunohistochemistry for androgen receptor and 5α-reductase. Results In all 58 cases, expression rates were 57% for androgen receptor and 55% for 5α-reductase, with 38% double-positivity for androgen receptor and 5α-reductase. Only 5α-reductase expression rate was significantly higher in invasive cases (81%) than in noninvasive cases (45%; P = 0·042). For invasive cases, numbers of double-positive results for androgen receptor and 5α-reductase were significantly higher in men (70%) than in women (17%; P = 0·039). Conclusions Double positivity for androgen receptor and 5α-reductase in Paget cells suggests autocrine synthesis of androgens in extramammary Paget disease. The different hormonal microenvironments in male and female cases and intratumoral androgen levels affect the invasiveness of extramammary Paget disease. © 2010 British Association of Dermatologists

    Cold preservation of the human colon and ileum with University of Wisconsin solution

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    The inclusion of the colon in the intestinal graft resulted in worsening patient and graft outcome and increased the incidence of infection and rejection. In this study, we examine the role of ischemia on the barrier function of the epithelium during cold ischemia. Samples were collected from 15 harvested and transplanted human donor grafts (colon, 10; ileum, 6), which were immersed in University of Wisconsin (UW) solution. Ischemia (6, 12, 24, and 45 h) and reoxygenation were performed to evaluate the mucosal electrical status using the Ussing chamber technique. The functions of enterocytes and crypt cells were tested by glucose and theophylline challenge. Modified Park's classification was applied to evaluate the severity of mucosal damage under light microscopy. The colon had higher levels of baseline potential difference, short-circuit current, and resistance than the ileum during 6-48 h of ischemia. Colonic epithelial cells responded well to theophylline stimulation at 24 h of ischemia, while there was no ileal response. The colonic mucosa was histopathologically well preserved in UW solution for 48 h, and mucosal damage induced by reoxygenation was less than in the ileum. In conclusion, electrophysiologically and histopathologically, the colon is less susceptible to cold preservation damage than the ileum during storage with UW solution

    Visualization of intrathoracically disseminated solid tumors in mice with optical imaging by telomerase-specific amplification of a transferred green fluorescent protein gene

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    Currently available methods for detection of tumors in vivo such as X-ray, computed tomography, and ultrasonography are noninvasive and have been well studied; the images, however, are not specific for tumors. Direct optical imaging of tumor cells in vivo that can clearly distinguish them from surrounding normal tissues may be clinically useful. Here, we describe a new approach to visualizing tumors whose fluorescence can be detected using tumor-specific replication-competent adenovirus (OBP-301, Telomelysin) in combination with Ad-GFP, a replication-deficient adenovirus expressing green fluorescent protein (GFP). Human telomerase reverse transcriptase is the catalytic subunit of telomerase, which is highly active in cancer cells but quiescent in most normal somatic cells. We constructed an adenovirus 5 vector in which the human telomerase reverse transcriptase promoter element drives expression of E1A and E1B genes linked with an internal ribosome entry site and showed that OBP-301 replicated efficiently in human cancer cells, but not in normal cells such as human fibroblasts. When the human lung and colon cancer cell lines were infected with Ad-GFP at a low multiplicity of infection, GFP expression could not be detected under a fluorescence microscope; in the presence of OBP-301, however, Ad-GFP replicated in these tumor cells and showed strong green signals. In contrast, coinfection with OBP-301 and Ad-GFP did not show any signals in normal cells such as fibroblasts and vascular endothelial cells. We also found that established subcutaneous tumors could be visualized after intraturnoral injection of OBP-301 and Ad-GFP. A549 human lung tumors and SW620 human colon tumors transplanted into BALB/c nu/nu mice were intraturnorally injected with 8 X 10(5) plaque-forming units of Ad-GFP in combination with 8 X 106 plaque-forming units of OBP-301. Within 3 days of treatment, the fluorescence of the expressed GFP became visible by a three-chip color cooled charged-coupled device camera in these tumors, whereas intraturnoral injection of Ad-GFP alone could not induce GFP fluorescence. Moreover, intrathoracic administration of Ad-GFP and OBP-301 could visualize disseminated A549 tumor nodules in mice after intrathoracic implantation. Our results indicate that intratumoral or intrathoracic injection of Ad-GFP in combination with OBP-301 might be a useful diagnostic method that provides a foundation for future clinical application

    Genetic and clinical landscape of breast cancers with germline BRCA1/2 variants

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    遺伝性乳癌の遺伝学的・臨床学的特徴を解明 --BRCA1/2 変異乳癌は両アレルの不活化の有無により異なった特徴を持つ--. 京都大学プレスリリース. 2020-10-26.The genetic and clinical characteristics of breast tumors with germline variants, including their association with biallelic inactivation through loss-of-heterozygosity (LOH) and second somatic mutations, remain elusive. We analyzed germline variants of 11 breast cancer susceptibility genes for 1, 995 Japanese breast cancer patients, and identified 101 (5.1%) pathogenic variants, including 62 BRCA2 and 15 BRCA1 mutations. Genetic analysis of 64 BRCA1/2-mutated tumors including TCGA dataset tumors, revealed an association of biallelic inactivation with more extensive deletions, copy neutral LOH, gain with LOH and younger onset. Strikingly, TP53 and RB1 mutations were frequently observed in BRCA1- (94%) and BRCA2- (9.7%) mutated tumors with biallelic inactivation. Inactivation of TP53 and RB1 together with BRCA1 and BRCA2, respectively, involved LOH of chromosomes 17 and 13. Notably, BRCA1/2 tumors without biallelic inactivation were indistinguishable from those without germline variants. Our study highlights the heterogeneity and unique clonal selection pattern in breast cancers with germline variants

    Autobullectomy with COVID-19 in a patient with chronic obstructive pulmonary disease

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    application/pdfA 72-year-old man with chronic obstructive pulmonary disease (COPD) was admitted for coronavirus disease 2019 (COVID-19). He was discharged on day 30; however, he was readmitted 6 days later due to a left lung organizing pneumonia secondary to COVID-19. After methylprednisolone treatment, the patient was discharged on day 15. One year later, computed tomography showed shrinkage of emphysematous lesions, and both total lung capacity measured using computed tomography and fraction of low attenuation volume decreased in the left lung compared to that before COVID-19. Here, we report a rare case of autobullectomy with COVID-19 in a patient with COPD.Journal Articlejournal articl

    Evolutionary histories of breast cancer and related clones

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    乳がん発生の進化の歴史を解明 --ゲノム解析による発がんメカニズムの探索--. 京都大学プレスリリース. 2023-07-28.Tracking the ol' mutation trail: Unraveling the long history of breast cancer formation. 京都大学プレスリリース. 2023-08-31.Recent studies have documented frequent evolution of clones carrying common cancer mutations in apparently normal tissues, which are implicated in cancer development1, 2, 3. However, our knowledge is still missing with regard to what additional driver events take place in what order, before one or more of these clones in normal tissues ultimately evolve to cancer. Here, using phylogenetic analyses of multiple microdissected samples from both cancer and non-cancer lesions, we show unique evolutionary histories of breast cancers harbouring der(1;16), a common driver alteration found in roughly 20% of breast cancers. The approximate timing of early evolutionary events was estimated from the mutation rate measured in normal epithelial cells. In der(1;16)(+) cancers, the derivative chromosome was acquired from early puberty to late adolescence, followed by the emergence of a common ancestor by the patient’s early 30s, from which both cancer and non-cancer clones evolved. Replacing the pre-existing mammary epithelium in the following years, these clones occupied a large area within the premenopausal breast tissues by the time of cancer diagnosis. Evolution of multiple independent cancer founders from the non-cancer ancestors was common, contributing to intratumour heterogeneity. The number of driver events did not correlate with histology, suggesting the role of local microenvironments and/or epigenetic driver events. A similar evolutionary pattern was also observed in another case evolving from an AKT1-mutated founder. Taken together, our findings provide new insight into how breast cancer evolves
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