Applying Cluster Ensemble to Adaptive Tree Structured Clustering

Adaptive tree structured clustering (ATSC) is our proposed divisive hierarchical clustering method that recursively divides a data set into 2 subsets using self-organizing feature map (SOM). In each partition, the data set is quantized by SOM and the quantized data is divided using agglomerative hierarchical clustering. ATSC can divide data sets regardless of data size in feasible time. On the other hand clustering result stability of ATSC is equally unstable as other divisive hierarchical clustering and partitioned clustering methods. In this paper, we apply cluster ensemble for each data partition of ATSC in order to improve stability. Cluster ensemble is a framework for improving partitioned clustering stability. As a result of applying cluster ensemble, ATSC yields unique clustering results that could not be yielded by previous hierarchical clustering methods. This is because a different class distances function is used in each division in ATSC

長期ホルマリン固定により失活したProliferating Cell Nuclear Antigen (PCNA) の免疫反応性回復条件の基礎的検討 ―マイクロウェーブ、オートクレーブの影響について―

Using paraffin-embedded tissue sections of liver cancer obtained from autopsy which had been preserved in 10% buffered formalin solution for 6 months while PCNA immunoreactivity was lost, we examined the effects of heat processing by either microwave(MW) and autoclave(AC) in the presence of various processing solution. It appeared that AC processing took shorter time period than MW irradiation to restore equal immunoreactivity. With regard to immunoreactivity retrieval by MW irradiation,however, variation of the degree of retrieval depending on processing time was smaller than in AC, and so the stable consequences were obtained. Although AC processed tissues tended to be stained deep, prolonged processing time presented strong background staining and blurred nuclear margins which made it difficult to estimate the positive cell count. As for the effects of processing solution, there was little difference in retrieval of PCNA among 0.01 M citrate buffer (pH 6.0), saturated solution of lead thiocyanate and distilled water, but the least background staining was observed with distilled water. These observations suggest that MW irradiation of which effect of retrieval is less dependent of processing time and with the least background stainability, is superior to AC processing for PCNA immunoreactivity retrieval on formalin-fixed tissues.10％緩衝ホルマリンに6ヶ月間浸漬していた剖検材料（肝臓癌）のパラフィン包埋後の組織切片を用いて、ホルマリンの固定作用により失活したPCNAの免疫反応性の回復にマイクロウェーブ（MW）及びオートクレーブ（AC）による熱処理とその時用いる処理溶液が、どのような影響を与えるかについて検討した。その結果、同等の免疫反応性を回復するのには、AC処理の方がMW照射より短時間でよいことが解った。しかし、MW照射による免疫反応性回復では、処理時間による影響がAC処理に比べて少なく、安定した結果が得られた。また、PCNAの染色所見については、AC処理の方が濃く染まる傾向が見られた。しかし、処理時間が長くなるとバックグラウンドの染色性が高くなる、核の周囲ににじみ現象が見られる等の所見があり判定に困難をきたした。一方、処理溶液についてはクエン酸（0.01M pH6.0）、チオシアン酸鉛飽和溶液、蒸留水について検討を行った結果、PCNAの回復には差は認められなかったが、バックグラウンドの染色については蒸留水が最も少なかった。以上の結果により、ホルマリン固定により失活したPCNAの免疫反応性を回復するには、MW照射の方がAC処理より処理時間に関係なく安定した染色性が得られ、なおかつバックグラウンドの染色性が少ない等の点で優れていることが示唆された

MOOCs コース設計の10要素モデル : インストラクショナルデザイン理論を基盤とした学習の質設計モデルの提案

熊本大

Molecular imaging analysis of microvesicular and macrovesicular lipid droplets in non‑alcoholic fatty liver disease by Raman microscopy

Predominant evidence of non-alcoholic fatty liver disease (NAFLD) is the accumulation of excess lipids in the liver. A small group with NAFLD may have a more serious condition named non-alcoholic steatohepatitis (NASH). However, there is a lack of investigation of the accumulated lipids with spatial and molecular information. Raman microscopy has the potential to characterise molecular species and structures of lipids based on molecular vibration and can achieve high spatial resolution at the organelle level. In this study, we aim to demonstrate the feasibility of Raman microscopy for the investigation of NAFLD based on the molecular features of accumulated lipids. By applying the Raman microscopy to the liver of the NASH model mice, we succeeded in visualising the distribution of lipid droplets (LDs) in hepatocytes. The detailed analysis of Raman spectra revealed the difference of molecular structural features of the LDs, such as the degree of saturation of lipids in the LDs. We also found that the inhomogeneous distribution of cholesterol in the LDs depending on the histology of lipid accumulation. We visualised and characterised the lipids of NASH model mice by Raman microscopy at organelle level. Our findings demonstrated that the Raman imaging analysis was feasible to characterise the NAFLD in terms of the molecular species and structures of lipids

Assessment of Ultra-Early-Stage Liver Fibrosis in Human Non-Alcoholic Fatty Liver Disease by Second-Harmonic Generation Microscopy

Non-alcoholic fatty liver disease (NAFLD) is associated with the chronic progression of fibrosis. In general, the progression of liver fibrosis is determined by a histopathological assessment with a collagen-stained section; however, the ultra-early stage of liver fibrosis is challenging to identify because of the low sensitivity in the collagen-selective staining method. In the present study, we demonstrate the feasibility of second-harmonic generation (SHG) microscopy in the histopathological diagnosis of the liver of NAFLD patients for the quantitative assessment of the ultra-early stage of fibrosis. We investigated four representative NAFLD patients with early stages of fibrosis. SHG microscopy visualised well-matured fibrotic structures and early fibrosis diffusely involving liver tissues, whereas early fibrosis is challenging to be identified by conventional histopathological methods. Furthermore, the SHG emission directionality analysis revealed the maturation of each collagen fibre of each patient. As a result, SHG microscopy is feasible for assessing liver fibrosis on NAFLD patients, including the ultra-early stage of liver fibrosis that is difficult to diagnose by the conventional histopathological method. The assessment method of the ultra-early fibrosis by using SHG microscopy may serve as a crucial means for pathological, clinical, and prognostic diagnosis of NAFLD patients

奈良における侵襲性GBS感染症における臨床的特徴と分子疫学的特徴(2007～2016年)

Invasive Streptococcus agalactiae (GBS) infections are increasingly common among neonates and the elderly. Therefore, GBS surveillance for better antibiotic treatment and prophylaxis strategies are needed. We retrospectively evaluated the clinical aspects of invasive infections and the phenotypic and genetic diversity of infectious isolates from Nara, Japan, collected between 2007 and 2016, by using information from hospital records. GBS strains collected from the blood and cerebrospinal fluid cultures were evaluated for capsular types, multi-locus sequence typing (MLST), antibiotic susceptibility, antibiotics resistance gene, and pulsed-field gel electrophoresis. Forty GBS isolates (10 from children and 30 from adults) were analyzed, and the distribution of molecular serotype and allelic profiles varied between children and adults. We found the rates of early-onset disease in neonates with birth complications to be higher than that of previous reports, indicating that there could be relevance between complications at birth and early-onset disease. Standard antibiotic prophylaxis strategies may need to be reconsidered in patients with birth complications. In adults, the mean age of the patients was 68 years (male: 63%). Primary bacteremia was the most common source of infection. In the neonates, six had early-onset diseases and four had late-onset diseases. The most frequently identified strains were molecular serotype Ia ST23 (40%) and molecular serotype Ib ST10 (20%) in children and molecular serotype Ib ST10 (17%), molecular serotype VI ST1 (13%), and molecular serotype V ST1 (13%) in adults. Levofloxacin-resistant molecular serotype Ib strains and molecular serotypes V and VI ST1 were common causes of GBS infection in adults but were rarely found in children. Furthermore, pulsed-field gel electrophoresis in our study showed that specific clone isolates, that tend to have antibiotics resistance were widespread horizontally for a decade. Continuous surveillance and molecular investigation are warranted to identify the transmission route and improve antibiotic treatment strategies.博士（医学）・甲第773号・令和3年3月15日Copyright: © 2020 Hirai et al. This is an open access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

PESI-MS for Diagnostic Cytology

Objectives: Cytology and histology are 2 indispensable diagnostic tools for cancer diagnosis, which are rapidly increasing in importance with aging populations. We applied mass spectrometry (MS) as a rapid approach for swiftly acquiring nonmorphological information of interested cells. Conventional MS, which primarily rely on promoting ionization by pre-applying a matrix to cells, has the drawback of time-consuming both on data acquisition and analysis. As an emerging method, probe electrospray ionization-MS (PESI-MS) with a dedicated probe is capable to pierce sample and measure specimen in small amounts, either liquid or solid, without the requirement for sample pretreatment. Furthermore, PESI-MS is timesaving compared to the conventional MS. Herein, we investigated the capability of PESI-MS to characterize the cell types derived from the respiratory tract of human tissues. Study Design: PESI-MS analyses with DPiMS-2020 were performed on various type of cultured cells including 5 lung squamous cell carcinomas, 5 lung adenocarcinomas, 5 small-cell carcinomas, 4 malignant mesotheliomas, and 2 normal controls. Results: Several characteristic peaks were detected at around m/z 200 and 800 that were common in all samples. As expected, partial least squares-discriminant analysis of PESI-MS data distinguished the cancer cell types from normal control cells. Moreover, distinct clusters divided squamous cell carcinoma from adenocarcinoma. Conclusion: PESI-MS presented a promising potential as a novel diagnostic modality for swiftly acquiring specific cytological information

Impact of extracellular matrix on engraftment and maturation of pluripotent stem cell-derived cardiomyocytes in a rat myocardial infarct model

Pluripotent stem cell-derived cardiomyocytes show great promise in regenerating the heart after myocardial infarction; however, several uncertainties exist that must be addressed before clinical trials. One practical issue is graft survival following transplantation. Although a pro-survival cocktail with Matrigel has been shown to enhance graft survival, the use of Matrigel may not be clinically feasible. The purpose of this study was to test whether a hyaluronan-based hydrogel, HyStem, could be a substitute for Matrigel. Human induced pluripotent stem cell-derived cardiomyocytes diluted with HyStem alone, HyStem plus pro-survival factors, or a pro-survival cocktail with Matrigel (PSC/MG), were transplanted into a rat model of acute myocardial infarction. Histological analysis at 4 weeks post transplantation revealed that, among the three groups, recipients of PSC/MG showed the largest graft size. Additionally, the grafted cardiomyocytes in the recipients of PSC/MG had a more matured phenotype compared to those in the other two groups. These findings suggest that further studies will be required to enhance not only graft size, but also the maturation of grafted cardiomyocytes.ArticleScientific reports 7(1) : 8630-(2017)journal articl