The Experts below are selected from a list of 3795 Experts worldwide ranked by ideXlab platform
Tsukasa Ashihara - One of the best experts on this subject based on the ideXlab platform.
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Relationship between chromosomal aberrations by fluorescence in situ hybridization and DNA ploidy by Cytofluorometry in osteosarcoma.
Cancer Letters, 1999Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Tsukasa Ashihara, Tatuto Abe, Johji InazawaAbstract:Abstract An analysis of the chromosomal aberrations and DNA ploidy in the interphase nuclei of seven human osteosacomas was preformed by double-target fluorescence in situ hybridization (FISH) and DNA Cytofluorometry. The FISH study of the numerical aberrations in chromosomes 1 and 17 or the structural aberrations in chromosome arm 1p or 17p was carried out by using four locus specific DNA markers, with one pair consisting of 1q12 and 1p36 and the other pair consisting of the 17 cemtromere and 17p13.3. There was no significant differences in the percentage of deletions in chromosome 1 and 17 between osteosarcomas and normal tissues. However, all seven tumors studied had extra copies. Cells with more than three probe signals were regarded as having chromosome polysomy. The percentage of polysomy of chromosome 1 was 20.0–64.0%, and chromosome 17 was 28.0–60.0%. The DNA ploidy patterns of hyperdiploid cells showing a greater DNA content than diploid cells were obtained by DNA cytoflurometry. Five of the seven tumors were non-diploid, and the remaining two were diploid. The percentage of polysomy was correlated with the percentage of hyperdiploid cells in each tumor. Thus, these findings indicated that the DNA ploidy changes were closely correlated with aberrations in the chromosome copy number in osteosarcomas.
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Ploidy analysis in paraffin-embedded malignant fibrous histiocytoma by DNA Cytofluorometry and fluorescence in situ hybridization
Cancer Letters, 1997Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Johji Inazawa, Tatuo Abe, Tsukasa AshiharaAbstract:To prove the relationship between chromosomal aberration and DNA ploidy in human malignant fibrous histiocytoma (MFH), fluorescence in situ hybridization (FISH) and DNA Cytofluorometry were performed in this study. For FISH study, the nucleus of each tumor cell was isolated from paraffin-embedded tissue of nine MFHs. Five chromosome-specific DNA probes (1p36, 1q12, 8q21.3, 11 centromere, and 17 centromere) were hybridized on cell nuclei. Cells with more than three probe signals were regarded as chromosome polysomy. All of the tumors analyzed by FISH had extra copies. The average percentage of polysomy in all tumors was high, ranging from 10.2% to 49.2%. The DNA ploidy patterns, and the percentage of hyperdiploid cells showing a greater DNA content than diploid cells, were obtained from DNA Cytofluorometry. Three of nine were diploid patterns and six were non-diploid patterns, and the percentage of hyperdiploid cells in all tumors was high, ranging from 9.1% to 61.9%. The percentage of polysomy could be correlated with the percentage of hyperdiploid cells in each cell. In this study, we found that the DNA ploidy change was closely correlated with aberrations of chromosome copy number in MFH. In addition, the alterations of specific chromosome copy number could be detected in MFH showing diploid cells. Thus, these data indicate that FISH and DNA Cytofluorometry are available as a cytogenetic tool for the analysis of interphase nuclei of bone and soft tissue tumors including MFH.
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EGF binding activity of rat hepatocytes in liver regeneration after partial hepatectomyCell cycle analysis by Cytofluorometry
International Hepatology Communications, 1993Co-Authors: Hisashi Tada, Yoji Urata, Keizo Kagawa, Hiroshi Hikita, Takayuki Takeuchi, Takeshi Okanoue, Kei Kashima, Tsukasa AshiharaAbstract:Abstract To analyze EGF binding activity in liver regeneration at cell cycle level, we performed the double measurement of nuclear DNA content and cellular bound EGF content in freshly isolated rat hepatocytes from normal and regenerating liver after 67% hepatectomy using autostaging Cytofluorometry. The data demonstrated that the bound EGF content of resting cells increased in proportion to their DNA content, while cycling cells had significantly consistently lower bound hEGF throughout cell cycle. These changes are supposed to reflect ‘down-regulation’ of EGF receptor at the cell cycle level, and the data suggested a major role of endogenous EGF in cell proliferation during liver regeneration.
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Analysis of cell proliferation kinetics and the effects of cisplatin on the cell cycle of human gastric cancer cells by autostage Cytofluorometry
Gan to kagaku ryoho. Cancer & chemotherapy, 1992Co-Authors: Azumi Y, Tsukasa Ashihara, Hirosumi Itoi, Eiichi Konishi, Urata Y, Yamaguchi N, Hayazo Kubo, Akira Horii, Hisakazu Yamagishi, Takahiro OkaAbstract:Analysis of both cell proliferation kinetics and effects of cis-diamminedichloroplatinum (CDDP) on cell cycle in human gastric cancer cell line (HGC-Y2) by measuring the contents of nuclear DNA, RNA and the Ki-67 antigen using autostage Cytofluorometry system was described. In HGC-Y2 cells, RNA content increased during the cell cycle and reached to the maximum at G2/M phase. The results of pulse treatment with CDDP on these cells demonstrated a prolongation of S phase and G2 arrest with increasing of RNA content of these cells. We classified the cells by intranuclear distribution pattern of Ki-67 antigen and thus could identified the cells at G0 and M phases from these classification. The content of Ki-67 antigen was moderate grade at G1 phase and it decreased in the early S phase, then increased gradually during S phase and at the late S phase. It increased rapidly, reaching to the maximum at G2/M phase. After CDDP treatment, the content of Ki-67 antigen increased in the cells in prolonged S phase and in the cells arrested at G2 phase. It was also found that the syntheses of both Ki-67 antigen and RNA were not inhibited by CDDP. These results suggest that the method using autostage Cytofluorometry system was useful for the research, on the mechanism of cancer therapy because of making possible to analyze precisely the cell cycle and the influence of anticancer drugs.
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Assessment of Malignancy of Bone and Soft Tissue Tumors Using DNA Cytofluorometry
Recent Advances in Musculoskeletal Oncology, 1992Co-Authors: Katsuyuki Kusuzaki, Tsukasa Ashihara, Yasusuke HirasawaAbstract:Many recent reports have demonstrated the usefulness of cytometric DNA ploidy analysis in assessing the nature of the malignancy of human tumors. Among the researchers who have attempted over the past 10 years to apply this technique to bone and soft tissue tumors [1–7], most believe that DNA ploidy analysis may be helpful not only for the histological diagnosis of malignancy but also in predicting prognosis. Most of these previous studies used flow cytometry, a method in which examiners are unable to determine the morphology of the studied cells, even though a large number of cells can be measured instantly. However, flow cytometry may not provide an accurate measurement of DNA content due to possible contamination with non-tumorous cells, such as fibroblasts, granulocytes, and lymphocytes, and a large amount of debris from bony, cartilaginous, and collagenous matrices that commonly appear in bone and soft tissue tumors. In order to avoid these problems, we attempted to analyze the DNA ploidy of bone and soft tissue tumors using Cytofluorometry. With this method, we were able to selectively measure only the tumor cells under a fluorescence microscope, although the measurable cell number was much lower than that obtained with flow cytometry and it was relatively time-consuming because we had to detect cells which had been smeared on a glass slide. The results of DNA ploidy analysis by Cytofluorometry were statistically comparable with histological evaluation of malignancy performed by pathologists.
Bo Thorell - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the Normoblast Population in β‐Thalassaemic Blood by Rapid‐Flow Cytofluorometry
Scandinavian Journal of Haematology, 2009Co-Authors: Eliezer A. Rachmilewitz, Bo ThorellAbstract:Samples of peripheral blood from patients with beta-thalassaemia major which contained significant numbers of nucleated normoblasts were stained with acridine orange and analyzed with rapid-flow Cytofluorometry. The pyknotic normoblast-nuclei gave less green 'DNA' fluorescence than the (diploid) leucocytes and constituted a separate, distinct subpopulation. Mean values of the fluorescence intensities and standard deviations as displayed by multichannel analyses gave a numerical value for normoblasts with regard to their maturation stages. These mean values correlated with the differential counts of 'early and late' normoblasts in the light microscope under rigidly standardized conditions. Rapid-flow Cytofluorometry thus provides an objective and quantitative way to monitor and define peripheral blood normoblast populations as a measure of the severity of 'erythropoietic stress'.
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characterization of the normoblast population in β thalassaemic blood by rapid flow Cytofluorometry
Scandinavian Journal of Haematology, 2009Co-Authors: Eliezer A. Rachmilewitz, Bo ThorellAbstract:Samples of peripheral blood from patients with beta-thalassaemia major which contained significant numbers of nucleated normoblasts were stained with acridine orange and analyzed with rapid-flow Cytofluorometry. The pyknotic normoblast-nuclei gave less green 'DNA' fluorescence than the (diploid) leucocytes and constituted a separate, distinct subpopulation. Mean values of the fluorescence intensities and standard deviations as displayed by multichannel analyses gave a numerical value for normoblasts with regard to their maturation stages. These mean values correlated with the differential counts of 'early and late' normoblasts in the light microscope under rigidly standardized conditions. Rapid-flow Cytofluorometry thus provides an objective and quantitative way to monitor and define peripheral blood normoblast populations as a measure of the severity of 'erythropoietic stress'.
Yasusuke Hirasawa - One of the best experts on this subject based on the ideXlab platform.
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Relationship between chromosomal aberrations by fluorescence in situ hybridization and DNA ploidy by Cytofluorometry in osteosarcoma.
Cancer Letters, 1999Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Tsukasa Ashihara, Tatuto Abe, Johji InazawaAbstract:Abstract An analysis of the chromosomal aberrations and DNA ploidy in the interphase nuclei of seven human osteosacomas was preformed by double-target fluorescence in situ hybridization (FISH) and DNA Cytofluorometry. The FISH study of the numerical aberrations in chromosomes 1 and 17 or the structural aberrations in chromosome arm 1p or 17p was carried out by using four locus specific DNA markers, with one pair consisting of 1q12 and 1p36 and the other pair consisting of the 17 cemtromere and 17p13.3. There was no significant differences in the percentage of deletions in chromosome 1 and 17 between osteosarcomas and normal tissues. However, all seven tumors studied had extra copies. Cells with more than three probe signals were regarded as having chromosome polysomy. The percentage of polysomy of chromosome 1 was 20.0–64.0%, and chromosome 17 was 28.0–60.0%. The DNA ploidy patterns of hyperdiploid cells showing a greater DNA content than diploid cells were obtained by DNA cytoflurometry. Five of the seven tumors were non-diploid, and the remaining two were diploid. The percentage of polysomy was correlated with the percentage of hyperdiploid cells in each tumor. Thus, these findings indicated that the DNA ploidy changes were closely correlated with aberrations in the chromosome copy number in osteosarcomas.
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Ploidy analysis in paraffin-embedded malignant fibrous histiocytoma by DNA Cytofluorometry and fluorescence in situ hybridization
Cancer Letters, 1997Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Johji Inazawa, Tatuo Abe, Tsukasa AshiharaAbstract:To prove the relationship between chromosomal aberration and DNA ploidy in human malignant fibrous histiocytoma (MFH), fluorescence in situ hybridization (FISH) and DNA Cytofluorometry were performed in this study. For FISH study, the nucleus of each tumor cell was isolated from paraffin-embedded tissue of nine MFHs. Five chromosome-specific DNA probes (1p36, 1q12, 8q21.3, 11 centromere, and 17 centromere) were hybridized on cell nuclei. Cells with more than three probe signals were regarded as chromosome polysomy. All of the tumors analyzed by FISH had extra copies. The average percentage of polysomy in all tumors was high, ranging from 10.2% to 49.2%. The DNA ploidy patterns, and the percentage of hyperdiploid cells showing a greater DNA content than diploid cells, were obtained from DNA Cytofluorometry. Three of nine were diploid patterns and six were non-diploid patterns, and the percentage of hyperdiploid cells in all tumors was high, ranging from 9.1% to 61.9%. The percentage of polysomy could be correlated with the percentage of hyperdiploid cells in each cell. In this study, we found that the DNA ploidy change was closely correlated with aberrations of chromosome copy number in MFH. In addition, the alterations of specific chromosome copy number could be detected in MFH showing diploid cells. Thus, these data indicate that FISH and DNA Cytofluorometry are available as a cytogenetic tool for the analysis of interphase nuclei of bone and soft tissue tumors including MFH.
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Assessment of Malignancy of Bone and Soft Tissue Tumors Using DNA Cytofluorometry
Recent Advances in Musculoskeletal Oncology, 1992Co-Authors: Katsuyuki Kusuzaki, Tsukasa Ashihara, Yasusuke HirasawaAbstract:Many recent reports have demonstrated the usefulness of cytometric DNA ploidy analysis in assessing the nature of the malignancy of human tumors. Among the researchers who have attempted over the past 10 years to apply this technique to bone and soft tissue tumors [1–7], most believe that DNA ploidy analysis may be helpful not only for the histological diagnosis of malignancy but also in predicting prognosis. Most of these previous studies used flow cytometry, a method in which examiners are unable to determine the morphology of the studied cells, even though a large number of cells can be measured instantly. However, flow cytometry may not provide an accurate measurement of DNA content due to possible contamination with non-tumorous cells, such as fibroblasts, granulocytes, and lymphocytes, and a large amount of debris from bony, cartilaginous, and collagenous matrices that commonly appear in bone and soft tissue tumors. In order to avoid these problems, we attempted to analyze the DNA ploidy of bone and soft tissue tumors using Cytofluorometry. With this method, we were able to selectively measure only the tumor cells under a fluorescence microscope, although the measurable cell number was much lower than that obtained with flow cytometry and it was relatively time-consuming because we had to detect cells which had been smeared on a glass slide. The results of DNA ploidy analysis by Cytofluorometry were statistically comparable with histological evaluation of malignancy performed by pathologists.
Eliezer A. Rachmilewitz - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the Normoblast Population in β‐Thalassaemic Blood by Rapid‐Flow Cytofluorometry
Scandinavian Journal of Haematology, 2009Co-Authors: Eliezer A. Rachmilewitz, Bo ThorellAbstract:Samples of peripheral blood from patients with beta-thalassaemia major which contained significant numbers of nucleated normoblasts were stained with acridine orange and analyzed with rapid-flow Cytofluorometry. The pyknotic normoblast-nuclei gave less green 'DNA' fluorescence than the (diploid) leucocytes and constituted a separate, distinct subpopulation. Mean values of the fluorescence intensities and standard deviations as displayed by multichannel analyses gave a numerical value for normoblasts with regard to their maturation stages. These mean values correlated with the differential counts of 'early and late' normoblasts in the light microscope under rigidly standardized conditions. Rapid-flow Cytofluorometry thus provides an objective and quantitative way to monitor and define peripheral blood normoblast populations as a measure of the severity of 'erythropoietic stress'.
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characterization of the normoblast population in β thalassaemic blood by rapid flow Cytofluorometry
Scandinavian Journal of Haematology, 2009Co-Authors: Eliezer A. Rachmilewitz, Bo ThorellAbstract:Samples of peripheral blood from patients with beta-thalassaemia major which contained significant numbers of nucleated normoblasts were stained with acridine orange and analyzed with rapid-flow Cytofluorometry. The pyknotic normoblast-nuclei gave less green 'DNA' fluorescence than the (diploid) leucocytes and constituted a separate, distinct subpopulation. Mean values of the fluorescence intensities and standard deviations as displayed by multichannel analyses gave a numerical value for normoblasts with regard to their maturation stages. These mean values correlated with the differential counts of 'early and late' normoblasts in the light microscope under rigidly standardized conditions. Rapid-flow Cytofluorometry thus provides an objective and quantitative way to monitor and define peripheral blood normoblast populations as a measure of the severity of 'erythropoietic stress'.
Katsuyuki Kusuzaki - One of the best experts on this subject based on the ideXlab platform.
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Relationship between chromosomal aberrations by fluorescence in situ hybridization and DNA ploidy by Cytofluorometry in osteosarcoma.
Cancer Letters, 1999Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Tsukasa Ashihara, Tatuto Abe, Johji InazawaAbstract:Abstract An analysis of the chromosomal aberrations and DNA ploidy in the interphase nuclei of seven human osteosacomas was preformed by double-target fluorescence in situ hybridization (FISH) and DNA Cytofluorometry. The FISH study of the numerical aberrations in chromosomes 1 and 17 or the structural aberrations in chromosome arm 1p or 17p was carried out by using four locus specific DNA markers, with one pair consisting of 1q12 and 1p36 and the other pair consisting of the 17 cemtromere and 17p13.3. There was no significant differences in the percentage of deletions in chromosome 1 and 17 between osteosarcomas and normal tissues. However, all seven tumors studied had extra copies. Cells with more than three probe signals were regarded as having chromosome polysomy. The percentage of polysomy of chromosome 1 was 20.0–64.0%, and chromosome 17 was 28.0–60.0%. The DNA ploidy patterns of hyperdiploid cells showing a greater DNA content than diploid cells were obtained by DNA cytoflurometry. Five of the seven tumors were non-diploid, and the remaining two were diploid. The percentage of polysomy was correlated with the percentage of hyperdiploid cells in each tumor. Thus, these findings indicated that the DNA ploidy changes were closely correlated with aberrations in the chromosome copy number in osteosarcomas.
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Ploidy analysis in paraffin-embedded malignant fibrous histiocytoma by DNA Cytofluorometry and fluorescence in situ hybridization
Cancer Letters, 1997Co-Authors: Hiroaki Murata, Katsuyuki Kusuzaki, Yasusuke Hirasawa, Johji Inazawa, Tatuo Abe, Tsukasa AshiharaAbstract:To prove the relationship between chromosomal aberration and DNA ploidy in human malignant fibrous histiocytoma (MFH), fluorescence in situ hybridization (FISH) and DNA Cytofluorometry were performed in this study. For FISH study, the nucleus of each tumor cell was isolated from paraffin-embedded tissue of nine MFHs. Five chromosome-specific DNA probes (1p36, 1q12, 8q21.3, 11 centromere, and 17 centromere) were hybridized on cell nuclei. Cells with more than three probe signals were regarded as chromosome polysomy. All of the tumors analyzed by FISH had extra copies. The average percentage of polysomy in all tumors was high, ranging from 10.2% to 49.2%. The DNA ploidy patterns, and the percentage of hyperdiploid cells showing a greater DNA content than diploid cells, were obtained from DNA Cytofluorometry. Three of nine were diploid patterns and six were non-diploid patterns, and the percentage of hyperdiploid cells in all tumors was high, ranging from 9.1% to 61.9%. The percentage of polysomy could be correlated with the percentage of hyperdiploid cells in each cell. In this study, we found that the DNA ploidy change was closely correlated with aberrations of chromosome copy number in MFH. In addition, the alterations of specific chromosome copy number could be detected in MFH showing diploid cells. Thus, these data indicate that FISH and DNA Cytofluorometry are available as a cytogenetic tool for the analysis of interphase nuclei of bone and soft tissue tumors including MFH.
-
Assessment of Malignancy of Bone and Soft Tissue Tumors Using DNA Cytofluorometry
Recent Advances in Musculoskeletal Oncology, 1992Co-Authors: Katsuyuki Kusuzaki, Tsukasa Ashihara, Yasusuke HirasawaAbstract:Many recent reports have demonstrated the usefulness of cytometric DNA ploidy analysis in assessing the nature of the malignancy of human tumors. Among the researchers who have attempted over the past 10 years to apply this technique to bone and soft tissue tumors [1–7], most believe that DNA ploidy analysis may be helpful not only for the histological diagnosis of malignancy but also in predicting prognosis. Most of these previous studies used flow cytometry, a method in which examiners are unable to determine the morphology of the studied cells, even though a large number of cells can be measured instantly. However, flow cytometry may not provide an accurate measurement of DNA content due to possible contamination with non-tumorous cells, such as fibroblasts, granulocytes, and lymphocytes, and a large amount of debris from bony, cartilaginous, and collagenous matrices that commonly appear in bone and soft tissue tumors. In order to avoid these problems, we attempted to analyze the DNA ploidy of bone and soft tissue tumors using Cytofluorometry. With this method, we were able to selectively measure only the tumor cells under a fluorescence microscope, although the measurable cell number was much lower than that obtained with flow cytometry and it was relatively time-consuming because we had to detect cells which had been smeared on a glass slide. The results of DNA ploidy analysis by Cytofluorometry were statistically comparable with histological evaluation of malignancy performed by pathologists.
