Yuqin Bai
University of Yamanashi
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Publication
Featured researches published by Yuqin Bai.
Cancer | 2008
Nobuhiko Ohno; Nobuo Terada; Yuqin Bai; Sei Saitoh; Tadao Nakazawa; Nobuki Nakamura; Ichiro Naito; Yasuhisa Fujii; Ryohei Katoh; Shinichi Ohno
Assessment of tissue specimens obtained with common immersion‐fixation followed by dehydration (IMDH) is affected by artifacts, which hinder precise evaluation of the histology and microenvironment of tumor tissues. The technical characteristics of cryobiopsy and in vivo cryotechnique (IVCT) where target organs are directly cryofixed in vivo are still unknown in practical examinations of tumor histopathology and microenvironment.
Medical Molecular Morphology | 2011
Yuqin Bai; Nobuhiko Ohno; Nobuo Terada; Sei Saitoh; Tadao Nakazawa; Nobuki Nakamura; Ryohei Katoh; Shinichi Ohno
Tumor behavior depends on the complex tumor interstitium and microenvironment, which influence transport of fluid and soluble molecules from blood vessels. The purpose of this study was to reveal how complex tumor tissues affect the immunodistribution of serum proteins and time-dependent translocation of bovine serum albumin (BSA) from blood vessels, using relatively differentiated human adenocarcinoma produced by the xenografted A549 cell line. Histological architecture and immunodistribution of the serum proteins in adenocarcinomatous tissues were clearly detected by the in vivo cryotechnique and cryobiopsy. Both albumin and IgG1 were detected in blood vessels, connective tissues around the tumor mass, and the interstitium among tumor cell nests. IgM was mainly detected in blood vessels and connective tissues around the tumor mass but was not detected in the interstitium among the tumor cell nests. At 10 or 30 min after BSA injection, BSA was observed only in blood vessels, but 1 h after the injection, it was also detected in the interstitium and surrounding connective tissues of the tumor mass. The present findings showed topographic variation of molecular permeation in the adenocarcinomatous tumor mass. The interstitial tissues with augmented permeability of serum proteins would increase accessibility of tumor cells to blood-derived molecules.
Medical Molecular Morphology | 2012
Yuqin Bai; Bao Wu; Nobuo Terada; Yurika Saitoh; Nobuhiko Ohno; Sei Saitoh; Shinichi Ohno
It has been difficult to clarify the precise localizations of soluble serum proteins in thymic tissues of living animals with conventional immersion- or perfusion-fixation followed by alcohol dehydration owing to ischemia and anoxia. In this study, “in vivo cryotechnique” (IVCT) followed by freeze-substitution fixation was performed to examine the thymic structures of living mice and immunolocalizations of intrinsic or extrinsic serum proteins, which were albumin, immunoglobulin G1 (IgG1), IgA, and IgM, as well as intravenously injected bovine serum albumin (BSA). Mouse albumin was more clearly immunolocalized in blood vessels and interstitial matrices of the thymic cortex than in tissues prepared by the conventional methods. The immunoreactivities of albumin and IgG1 were stronger than those of IgA and IgM in the interstitium of subcapsular cortex. The injected BSA was time-dependently immunolocalized in blood vessels and the interstitium of corticomedullary areas at 3.5 h after its injection, and then gradually diffused into the interstitium of the whole cortex at 6 h and 12 h. Thus, IVCT revealed definite immunolocalizations of serum albumin and IgG1 in the interstitium of thymus of living mice, indicating different accessibility of serum proteins from the corticomedullary areas, not from the subcapsular cortex of living animals, depending on various molecular sizes and concentrations.
Acta Histochemica Et Cytochemica | 2011
Yuqin Bai; Bao Wu; Nobuo Terada; Nobuhiko Ohno; Sei Saitoh; Yurika Saitoh; Shinichi Ohno
The “in vivo cryotechnique” (IVCT) is a powerful tool to directly freeze living animal organs in order to maintain biological components in frozen tissues, reflecting their native states. In this study, mesenteric lymph nodes of living mice were directly frozen with IVCT, and we did morphological studies and immunohistochemical analyses on a hyaluronic acid receptor, LYVE-1. In lymph nodes, widely open lymphatic sinuses were observed, and many lymphocytes adhered to inner endothelial cells along subcapsular sinuses. The LYVE-1 was clearly immunolocalized at inner endothelial cells of subcapsular sinuses, as well as those of medullary sinuses. Conventional pre-embedding electron microscopy also showed LYVE-1 immunolocalization along both the apical and basal sides of cell membranes of inner endothelial cells. By triple-immunostaining for LYVE-1, smooth muscle actin, and type IV collagen, the LYVE-1 was immunolocalized only in the inner endothelial cells, but not in outer ones which were surrounded by collagen matrix and smooth muscle cells. Thus, the functional morphology of lymph nodes in vivo was demonstrated and LYVE-1 immunolocalization in inner endothelial cells of subcapsular sinuses suggests hyaluronic acid incorporation into lymph node parenchyma.
Archive | 2016
Yuqin Bai; Nobuhiko Ohno; Nobuo Terada; Shinichi Ohno
Tumor behavior depends on the complex tumor interstitium and microenvironment, which influence transport of fluid and soluble molecules from blood vessels. The purpose of this study was to reveal how complex tumor tissues affect the immunodistribution of serum proteins and time-dependent translocation of bovine serum albumin (BSA) from blood vessels, using relatively differentiated human adenocarcinoma produced by the xenografted A549 cell line. Histological architecture and immunodistribution of the serum proteins in adenocarcinomatous tissues were clearly detected by the in vivo cryotechnique and cryobiopsy. Both albumin and IgG1 were detected in blood vessels, connective tissues around the tumor mass, and the interstitium among tumor cell nests. IgM was mainly detected in blood vessels and connective tissues around the tumor mass but was not detected in the interstitium among the tumor cell nests. At 10 or 30 min after BSA injection, BSA was observed only in blood vessels, but 1 h after the injection, it was also detected in the interstitium and surrounding connective tissues of the tumor mass. The present findings showed topographic variation of molecular permeation in the adenocarcinomatous tumor mass. The interstitial tissues with augmented permeability of serum proteins would increase accessibility of tumor cells to blood-derived molecules.
Archive | 2016
Bao Wu; Nobuhiko Ohno; Yurika Saitoh; Yuqin Bai; Zheng Huang; Nobuo Terada; Shinichi Ohno
The “in vivo cryotechnique” (IVCT) is useful to capture dynamic blood flow conditions. We injected various concentrations of horseradish peroxidase (HRP) into anesthetized mice via left ventricles to examine architectures of thymic blood vessels and their permeability at different time intervals. At 30 s after HRP injection, enzyme reaction products were weakly detected in interstitium around some thick blood vessels of corticomedullary boundary areas, but within capillaries of cortical areas. At 1 and 3 min, they were more widely detected in interstitium around all thick blood vessels of the boundary areas. At 10 min, they were diffusely detected throughout interstitium of cortical areas and more densely seen in medullary areas. At 15 min, however, they were uniformly detected throughout interstitium outside the blood vessels. At 30 min, phagocytosis of HRP by macrophages was scattered throughout the interstitium, which was accompanied by the decrease of HRP reaction intensity in interstitial matrices. Thus, time-dependent HRP distributions in living mice indicate that molecular permeability and diffusion depend on different areas of thymic tissues.
Archive | 2016
Yuqin Bai; Bao Wu; Nobuo Terada; Nobuhiko Ohno; Yurika Saitoh; Shinichi Ohno
The “in vivo cryotechnique” (IVCT) is a powerful tool to directly freeze living animal organs in order to maintain biological components in frozen tissues, reflecting their native states. In this study, mesenteric lymph nodes of living mice were directly frozen with IVCT, and we did morphological studies and immunohistochemical analyses on a hyaluronic acid receptor, LYVE-1. In lymph nodes, widely open lymphatic sinuses were observed, and many lymphocytes adhered to inner endothelial cells along subcapsular sinuses. The LYVE-1 was clearly immunolocalized at inner endothelial cells of subcapsular sinuses, as well as those of medullary sinuses. Conventional pre-embedding electron microscopy also showed LYVE-1 immunolocalization along both the apical and basal sides of cell membranes of inner endothelial cells. By triple immunostaining for LYVE-1, smooth muscle actin, and type IV collagen, the LYVE-1 was immunolocalized only in the inner endothelial cells, but not in outer ones which were surrounded by collagen matrix and smooth muscle cells. Thus, the functional morphology of lymph nodes in vivo was demonstrated and LYVE-1 immunolocalization in inner endothelial cells of subcapsular sinuses suggests hyaluronic acid incorporation into lymph node parenchyma.
Archive | 2016
Yuqin Bai; Nobuhiko Ohno; Nobuo Terada; Shinichi Ohno
The transport mechanism of soluble molecules throughout the interstitial matrix is closely associated with human tumor behavior in vivo. However, the examination of soluble components in histological architectures has been hampered by artifacts caused during conventional tissue preparation. In this study, the immunodistribution of intrinsic and extrinsic serum components in tumor tissues was examined in xenografted human lung large carcinoma cells using “in vivo cryotechnique” (IVCT) and cryobiopsy, where target tissues are directly cryofixed in vivo. Human lung cancer cells were subcutaneously injected into the dorsal flank of nude mice, and paraffin sections and cryosections of produced tumors were prepared with different methods. Immunolocalization of serum proteins, including albumin, immunoglobulin G (IgG), and IgM, as well as intravenously injected bovine serum albumin (BSA) was examined. Their immunodistribution was more clearly observed in the interstitium by both IVCT and cryobiopsy than conventional methods. IgM was immunolocalized within blood vessels, whereas albumin and IgG were observed in the tumor interstitium. Moreover, intravenously injected bovine serum albumin exhibited leakage from the blood capillaries into surrounding connective tissues in 24 h, but it gradually diffused to the interstitium of the tumor masse in 3 days. These results suggest that molecular leakage from blood capillaries varies significantly in different areas of developing tumors and that small serum proteins, but not large ones, were abundantly immunolocalized in the tumor interstitium. Both IVCT and cryobiopsy were found to be useful for immunohistochemical studies of soluble molecules in tumors with blood circulation and may therefore be helpful for further histopathological analyses.
Archive | 2016
Yuqin Bai; Bao Wu; Nobuo Terada; Yurika Saitoh; Nobuhiko Ohno; Sei Saitoh; Shinichi Ohno
It has been difficult to clarify the precise localizations of soluble serum proteins in thymic tissues of living animals with conventional immersion or perfusion fixation followed by alcohol dehydration owing to ischemia and anoxia. In this study, “in vivo cryotechnique” (IVCT) followed by freeze-substitution fixation was performed to examine the thymic structures of living mice and immunolocalizations of intrinsic or extrinsic serum proteins, which were albumin, immunoglobulin G1 (IgG1), IgA, and IgM, as well as intravenously injected bovine serum albumin (BSA). Mouse albumin was more clearly immunolocalized in blood vessels and interstitial matrices of the thymic cortex than in tissues prepared by the conventional methods. The immunoreactivities of albumin and IgG1 were stronger than those of IgA and IgM in the interstitium of subcapsular cortex. The injected BSA was time-dependently immunolocalized in blood vessels and the interstitium of corticomedullary areas at 3.5 h after its injection and then gradually diffused into the interstitium of the whole cortex at 6 and 12 h. Thus, IVCT revealed definite immunolocalizations of serum albumin and IgG1 in the interstitium of thymus of living mice, indicating different accessibility of serum proteins from the corticomedullary areas, not from the subcapsular cortex of living animals, depending on various molecular sizes and concentrations.
Acta Histochemica Et Cytochemica | 2014
Bao Wu; Nobuhiko Ohno; Yurika Saitoh; Yuqin Bai; Zheng Huang; Nobuo Terada; Shinichi Ohno
It is difficult to understand the in vivo permeability of thymic blood vessels, but “in vivo cryotechnique” (IVCT) is useful to capture dynamic blood flow conditions. We injected various concentrations of horseradish peroxidase (HRP) with or without quantum dots into anesthetized mice via left ventricles to examine architectures of thymic blood vessels and their permeability at different time intervals. At 30 sec after HRP (100 mg/ml) injection, enzyme reaction products were weakly detected in interstitium around some thick blood vessels of corticomedullary boundary areas, but within capillaries of cortical areas. At 1 and 3 min, they were more widely detected in interstitium around all thick blood vessels of the boundary areas. At 10 min, they were diffusely detected throughout interstitium of cortical areas, and more densely seen in medullary areas. At 15 min, however, they were uniformly detected throughout interstitium outside blood vessels. At 30 min, phagocytosis of HRP by macrophages was scattered throughout the interstitium, which was accompanied by decrease of HRP reaction intensity in interstitial matrices. Thus, time-dependent HRP distributions in living mice indicate that molecular permeability and diffusion depend on different areas of thymic tissues, resulting from topographic variations of local interstitial flow starting from corticomedullary areas.