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Steven B Haase - One of the best experts on this subject based on the ideXlab platform.
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Cell cycle Analysis of budding yeast using SYTOX Green.
Current protocols in cytometry, 2004Co-Authors: Steven B HaaseAbstract:Flow cytometric determination of DNA content is a standard tool for cell cycle Analysis in the budding yeast, Saccharomyces cerevisiae. Using SYTOX Green instead of propidium iodide (PI) in a standard ethanol fixation protocol increases the accuracy and reproducibility of cell cycle analyses. SYTOX-stained cells exhibit improved coefficients of variation (CVs), a better correlation between DNA content and fluorescence, and decreased sensitivity to variances in experimental conditions when compared with PI-stained cells. The SYTOX Green protocol provides researchers with a more accurate and reliable alternative to standard PI-based protocols for the Analysis of the budding yeast cell cycle.
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Current Protocols in Cytometry - Cell Cycle Analysis of Budding Yeast Using SYTOX Green
Current Protocols in Cytometry, 2003Co-Authors: Steven B HaaseAbstract:Flow cytometric determination of DNA content is a standard tool for cell cycle Analysis in the budding yeast, Saccharomyces cerevisiae. Using SYTOX Green instead of propidium iodide (PI) in a standard ethanol fixation protocol increases the accuracy and reproducibility of cell cycle analyses. SYTOX-stained cells exhibit improved coefficients of variation (CVs), a better correlation between DNA content and fluorescence, and decreased sensitivity to variances in experimental conditions when compared with PI-stained cells. The SYTOX Green protocol provides researchers with a more accurate and reliable alternative to standard PI-based protocols for the Analysis of the budding yeast cell cycle. Keywords: cell cycle; SYTOX Green; propidium iodide; flow cytometry
George Vartholomatos - One of the best experts on this subject based on the ideXlab platform.
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Correlation of DNA ploidy and cell cycle Analysis with diffusion tensor and dynamic susceptibility contrast MRI metrics in meningiomas
2018Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Anastasia K. Zikou, Maria I. ArgyropoulouAbstract:Purpose: To investigate the relationship between diffusion tensor imaging and dynamic susceptibility perfusion MRI metrics with cell cycle Analysis findings in meningiomas. Material and Methods: Fourteen patients (4 men, 10 women, aged 30-76 years; median 58 years) with meningiomas were included in the study. There were 9 grade I and 5 grade II meningiomas. The MRI protocol consisted of T2-weighted turbo spin echo, unenhanced and contrast enhanced T1-weighted 3D spoiled gradient echo sequences. Diffusion tensor imaging (DTI) metrics, such as apparent diffusion coefficient (ADC) and fractional anisotropy (FA), were assessed with a single shot, multi-slice, spin-echo planar sequence (max b-value: 700 sec/mm²) and dynamic susceptibility perfusion imaging (DSC) metrics, such as the relative cerebral blood volume (rCBV), with a T2* gradient-echo, multishot echo planar imaging sequence. DNA ploidy and cell cycle Analysis was analysed by flow cytometry. Results: There was a significant negative correlation between rCBV and G0/G1 phase fraction ( r =−0.791, p =0.004) and a positive correlation with G2/M phase fraction ( r =0.621, p =0.04). A significant correlation was also observed between FA ratio and G0/G1 phase fraction ( r =0.721, p =0.018). No significant correlation was found between G0/G1, S-phase, G2/M and ADC values. Conclusions: DSC MRI and DTI metrics are correlated to meningioma aggressiveness as assessed by cell cycle Analysis.
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The Role of Fast Cell Cycle Analysis in Pediatric Brain Tumors.
Pediatric Neurosurgery, 2015Co-Authors: George A. Alexiou, Kalliopi Stefanaki, Amalia Patereli, Georgia Tseka, George Sfakianos, Meropi Tzoufi, Efstathios G Lykoudis, George Vartholomatos, Neofytos ProdromouAbstract:Cell cycle Analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of a modified rapid (within 6 min) cell cycle Analysis protocol for the characterization of malignancy of pediatric brain tumors and for the differentiation of neoplastic from nonneoplastic tissue for possible intraoperative application. We retrospectively studied brain tumor specimens from patients treated at our institute over a 5-year period. All tumor samples were histopathologically verified before flow-cytometric Analysis. The histopathological examination of permanent tissue sections was the gold standard. There were 68 brain tumor cases. All tumors had significantly lower G₀/G1 and significantly higher S phase and mitosis fractions than normal brain tissue. Furthermore low-grade tumors could be differentiated from high-grade tumors. DNA aneuploidy was detected in 35 tumors. A correlation between S phase fraction and Ki-67 index was found in medulloblastomas and anaplastic ependymomas. Rapid cell cycle Analysis by flow cytometry is a promising method for the identification of neoplastic tissue intraoperatively. Low-grade tumors could be differentiated from high-grade tumors. Thus, cell cycle Analysis can be a valuable adjunct to the histopathological evaluation of pediatric brain tumors, whereas its intraoperative application warrants further investigation.
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the value of cell cycle Analysis by propidium iodine staining of cd56 cells in pediatric brain tumors
Clinical Neurology and Neurosurgery, 2015Co-Authors: George Vartholomatos, Kalliopi Stefanaki, Georgia Tseka, George Sfakianos, Meropi Tzoufi, George A. Alexiou, Efstathios G Lykoudis, Neofytos ProdromouAbstract:Abstract Purpose Cell cycle Analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of cell cycle Analysis by propidium-iodine (PI) staining of CD56+ (gated) cells for the characterization of pediatric brain tumor's malignancy. Methods Patients that underwent surgery for an intracranial lesion and tissue sample was available were included in the study. All tumor samples were histopathologically verified before flow cytometric Analysis. Results There were 46 pediatric brain tumor cases. As control we used samples from three cases of brain tissue obtained during surgery for epilepsy. All tumors had significant lower G 0 /G 1 and significant higher S-phase, G 2 /M fraction, S+G 2 /M and S+G 2 /M/G 0 /G 1 -phase fraction than normal brain tissue. Low-grade tumors had significant lower S-phase than high grade tumors. Grade IV tumors had significant lower G 0 /G 1 fraction and higher S+G 2 /M/G 0 /G 1 index than grade III tumors. DNA diploidy was detected in 24 tumors and DNA aneuploidy was detected in 23 tumors. There was a significant correlation between Ki-67 index and both S+G 2 /M and S+G 2 /M/G 0 /G 1 phase fraction. Conclusions Cell cycle Analysis by PI staining of CD56+ cells is a promising method for the assessment of pediatric brain tumors malignancy and could be a valuable adjunct to histopathological evaluation.
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Fast cell cycle Analysis for intraoperative characterization of brain tumor margins and malignancy
Journal of Clinical Neuroscience, 2015Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Anna Batistatou, Konstantinos I. Tsamis, Spyridon Voulgaris, Athanasios P. KyritsisAbstract:Flow cytometry, although indispensable for the characterization of hematologic malignancies, has not been extensively evaluated in solid tumors. To date intraoperative pathology evaluation of frozen sections of tissue obtained during surgery is the gold standard for intraoperative diagnosis. We investigated the value of a modified rapid protocol for cell cycle Analysis for the intraoperative characterization of intracranial lesions and their surgical margins. We investigated patients who underwent surgery for an intracranial lesion suspicious for a tumor. DNA Analysis and frozen sections were performed on tumor samples that were taken during surgery. Thirty-one patients met the inclusion criteria for the study. There was a significant difference in G0/G1 phase between high-grade and low-grade tumors. Receiver operating characteristic (ROC) Analysis provided 75% of G0/G1 fraction as the optimal cutoff value thresholding the discrimination between low and high-grade tumors. There was a significant difference in S-phase and mitoses fraction between high-grade and low-grade tumors. ROC Analysis indicated 6% of S-phase and 9.7% of mitoses as the optimal cutoff values thresholding the discrimination between these two groups. In the glioblastoma patients, we also analyzed the perilesional tissue and found significant differences between tumor mass and margins regarding the G0/G1 phase, the S-phase and mitoses fraction. In conclusion rapid cell cycle Analysis is a method capable of differentiating low from high-grade tumors and delineating tumor margins in gliomas. Thus, the role of cell cycle Analysis in brain tumors warrants further investigation.
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Correlation of diffusion tensor and dynamic susceptibility contrast MRI with DNA ploidy and cell cycle Analysis of gliomas.
Clinical Neurology and Neurosurgery, 2015Co-Authors: Anastasia K. Zikou, George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Vasileios G. Xydis, Paraskevi Kosta, Maria I. ArgyropoulouAbstract:Abstract Objectives Flow cytometry provides a powerful tool to assess cells in G 0 /G 1 , S and G 2 /M phase and ploidy. The purpose of the present study was to investigate the correlation between diffusion tensor (DTI) and dynamic susceptibility contrast (DSC) MRI metrics with cell cycle Analysis findings in gliomas. Patients and methods We studied thirty patients who were operated on for glioma. DTI and DSC MRI were performed within a week prior to surgical excision. Lesion/normal ratios were calculated for the ADC, FA and rCBV. In an excised tumour sample flow cytometric Analysis was performed. Results There were 24 glioblastomas, 2 anaplastic astrocytomas, 1 oligoastrocytoma and 3 diffuse astrocytomas. There were significant differences between low and high-grade gliomas for rCBV and ADC values. Low grade tumours had higher G 0 /G 1 phase fraction and lower S-phase, G 2 /M, S + G 2 /M and S + G 2 /M/G 0 /G 1 fractions There was a significant negative correlation between rCBV and G 0 /G 1 phase fraction and a positive correlation with G 2 /M, S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. Significant correlation was also observed between FA ratio and S + G 2 /M/G 0 /G 1 . There was a negative significant correlation between ADC and S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. There were 21 (70%) diploid and 9 (30%) aneuploid tumours. No significant difference was found between diploid and aneuploid tumours with respect to rCBV, ADC and FA values. Conclusion Dynamic susceptibility contrast MRI and diffusion tensor imaging metrics are correlated to tumour aggressiveness as assessed by cell cycle Analysis.
Athanasios P. Kyritsis - One of the best experts on this subject based on the ideXlab platform.
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Correlation of DNA ploidy and cell cycle Analysis with diffusion tensor and dynamic susceptibility contrast MRI metrics in meningiomas
2018Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Anastasia K. Zikou, Maria I. ArgyropoulouAbstract:Purpose: To investigate the relationship between diffusion tensor imaging and dynamic susceptibility perfusion MRI metrics with cell cycle Analysis findings in meningiomas. Material and Methods: Fourteen patients (4 men, 10 women, aged 30-76 years; median 58 years) with meningiomas were included in the study. There were 9 grade I and 5 grade II meningiomas. The MRI protocol consisted of T2-weighted turbo spin echo, unenhanced and contrast enhanced T1-weighted 3D spoiled gradient echo sequences. Diffusion tensor imaging (DTI) metrics, such as apparent diffusion coefficient (ADC) and fractional anisotropy (FA), were assessed with a single shot, multi-slice, spin-echo planar sequence (max b-value: 700 sec/mm²) and dynamic susceptibility perfusion imaging (DSC) metrics, such as the relative cerebral blood volume (rCBV), with a T2* gradient-echo, multishot echo planar imaging sequence. DNA ploidy and cell cycle Analysis was analysed by flow cytometry. Results: There was a significant negative correlation between rCBV and G0/G1 phase fraction ( r =−0.791, p =0.004) and a positive correlation with G2/M phase fraction ( r =0.621, p =0.04). A significant correlation was also observed between FA ratio and G0/G1 phase fraction ( r =0.721, p =0.018). No significant correlation was found between G0/G1, S-phase, G2/M and ADC values. Conclusions: DSC MRI and DTI metrics are correlated to meningioma aggressiveness as assessed by cell cycle Analysis.
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Fast cell cycle Analysis for intraoperative characterization of brain tumor margins and malignancy
Journal of Clinical Neuroscience, 2015Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Anna Batistatou, Konstantinos I. Tsamis, Spyridon Voulgaris, Athanasios P. KyritsisAbstract:Flow cytometry, although indispensable for the characterization of hematologic malignancies, has not been extensively evaluated in solid tumors. To date intraoperative pathology evaluation of frozen sections of tissue obtained during surgery is the gold standard for intraoperative diagnosis. We investigated the value of a modified rapid protocol for cell cycle Analysis for the intraoperative characterization of intracranial lesions and their surgical margins. We investigated patients who underwent surgery for an intracranial lesion suspicious for a tumor. DNA Analysis and frozen sections were performed on tumor samples that were taken during surgery. Thirty-one patients met the inclusion criteria for the study. There was a significant difference in G0/G1 phase between high-grade and low-grade tumors. Receiver operating characteristic (ROC) Analysis provided 75% of G0/G1 fraction as the optimal cutoff value thresholding the discrimination between low and high-grade tumors. There was a significant difference in S-phase and mitoses fraction between high-grade and low-grade tumors. ROC Analysis indicated 6% of S-phase and 9.7% of mitoses as the optimal cutoff values thresholding the discrimination between these two groups. In the glioblastoma patients, we also analyzed the perilesional tissue and found significant differences between tumor mass and margins regarding the G0/G1 phase, the S-phase and mitoses fraction. In conclusion rapid cell cycle Analysis is a method capable of differentiating low from high-grade tumors and delineating tumor margins in gliomas. Thus, the role of cell cycle Analysis in brain tumors warrants further investigation.
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Correlation of diffusion tensor and dynamic susceptibility contrast MRI with DNA ploidy and cell cycle Analysis of gliomas.
Clinical Neurology and Neurosurgery, 2015Co-Authors: Anastasia K. Zikou, George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Vasileios G. Xydis, Paraskevi Kosta, Maria I. ArgyropoulouAbstract:Abstract Objectives Flow cytometry provides a powerful tool to assess cells in G 0 /G 1 , S and G 2 /M phase and ploidy. The purpose of the present study was to investigate the correlation between diffusion tensor (DTI) and dynamic susceptibility contrast (DSC) MRI metrics with cell cycle Analysis findings in gliomas. Patients and methods We studied thirty patients who were operated on for glioma. DTI and DSC MRI were performed within a week prior to surgical excision. Lesion/normal ratios were calculated for the ADC, FA and rCBV. In an excised tumour sample flow cytometric Analysis was performed. Results There were 24 glioblastomas, 2 anaplastic astrocytomas, 1 oligoastrocytoma and 3 diffuse astrocytomas. There were significant differences between low and high-grade gliomas for rCBV and ADC values. Low grade tumours had higher G 0 /G 1 phase fraction and lower S-phase, G 2 /M, S + G 2 /M and S + G 2 /M/G 0 /G 1 fractions There was a significant negative correlation between rCBV and G 0 /G 1 phase fraction and a positive correlation with G 2 /M, S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. Significant correlation was also observed between FA ratio and S + G 2 /M/G 0 /G 1 . There was a negative significant correlation between ADC and S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. There were 21 (70%) diploid and 9 (30%) aneuploid tumours. No significant difference was found between diploid and aneuploid tumours with respect to rCBV, ADC and FA values. Conclusion Dynamic susceptibility contrast MRI and diffusion tensor imaging metrics are correlated to tumour aggressiveness as assessed by cell cycle Analysis.
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Rapid cell cycle Analysis for intraoperative diagnosis of brain tumors
Brain Tumor Pathology, 2014Co-Authors: George Vartholomatos, George A. Alexiou, Efstathios G Lykoudis, Anna Batistatou, Spyridon Voulgaris, Athanasios P. KyritsisAbstract:We read with great interest the recent article by Tanino et al. on the value of rapid immunohistochemistry (R-IHC) during brain tumor surgery. The authors developed a new immunohistochemistry method based on an alternating current electric field to facilitate the antigen–antibody reaction that could provide results for surgeons within 30 min [1]. The overall diagnostic accuracy of this method was 90.7 %. For the discrimination of lowand high-grade glioma, the authors evaluated supportive information of the Ki-67/MIB-1 index which could be completed within 16 min. Furthermore, in four cases of CNS lymphoma, CD20 and Ki-67/MIB-1 indices were successfully stained in all frozen samples using R-IHC. The authors concluded that R-IHC provides reliable results of IHC for CNS tumor diagnosis on frozen sections, and may contribute to an intraoperative rapid diagnosis [1]. Although flow cytometry has become a standard practice for the diagnosis, classification, staging and monitoring of patients with hematologic neoplasms, it has remained largely a research tool in solid tumors. Cell cycle Analysis by flow cytometry can provide important information on tumor’s aggressiveness [2]. Furthermore, although flow cytometric Analysis of DNA aneuploidy is not always associated with malignancy in several tumors, it is useful in brain tumors [3]. Recently, we have showed that based on G0/G1 and S-fraction we could differentiate lowfrom high-grade gliomas and benign from atypical/anaplastic meningiomas with high sensitivity and specificity (Fig. 1). In gliomas, a negative linear correlation between Ki-67 index and the G0/G1 fraction, and significant positive correlation between Ki-67 index and both S phase-fraction and mitoses were found. Apart from that, we have reported that cell cycle Analysis has an additional prognostic significance. Glioma patients with G0/G1 value lower than 69 % and S phase value greater than 6 % were associated with worse survival [2]. The cell cycle Analysis by flow cytometry usually requires 20 min. Recently, we developed a rapid cell cycle protocol that provides within 5 min intraoperative characterization of brain tumors and their margins [4]. The latter is of paramount importance to guide surgeon for tumor excision. Shioyama et al. also developed a rapid protocol for intraoperative characterization of resected gliomas by flow cytometry. By evaluating in 328 biopsy specimens the malignancy index, defined as the ratio of the number of cells with greater than normal DNA content to the total number of cells, Shioyama et al. [5] found significant differences between neoplastic and G. Vartholomatos Haematology Laboratory-Unit of Molecular Biology, University Hospital of Ioannina, 45500 Ioannina, Greece
George A. Alexiou - One of the best experts on this subject based on the ideXlab platform.
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Correlation of DNA ploidy and cell cycle Analysis with diffusion tensor and dynamic susceptibility contrast MRI metrics in meningiomas
2018Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Anastasia K. Zikou, Maria I. ArgyropoulouAbstract:Purpose: To investigate the relationship between diffusion tensor imaging and dynamic susceptibility perfusion MRI metrics with cell cycle Analysis findings in meningiomas. Material and Methods: Fourteen patients (4 men, 10 women, aged 30-76 years; median 58 years) with meningiomas were included in the study. There were 9 grade I and 5 grade II meningiomas. The MRI protocol consisted of T2-weighted turbo spin echo, unenhanced and contrast enhanced T1-weighted 3D spoiled gradient echo sequences. Diffusion tensor imaging (DTI) metrics, such as apparent diffusion coefficient (ADC) and fractional anisotropy (FA), were assessed with a single shot, multi-slice, spin-echo planar sequence (max b-value: 700 sec/mm²) and dynamic susceptibility perfusion imaging (DSC) metrics, such as the relative cerebral blood volume (rCBV), with a T2* gradient-echo, multishot echo planar imaging sequence. DNA ploidy and cell cycle Analysis was analysed by flow cytometry. Results: There was a significant negative correlation between rCBV and G0/G1 phase fraction ( r =−0.791, p =0.004) and a positive correlation with G2/M phase fraction ( r =0.621, p =0.04). A significant correlation was also observed between FA ratio and G0/G1 phase fraction ( r =0.721, p =0.018). No significant correlation was found between G0/G1, S-phase, G2/M and ADC values. Conclusions: DSC MRI and DTI metrics are correlated to meningioma aggressiveness as assessed by cell cycle Analysis.
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The Role of Fast Cell Cycle Analysis in Pediatric Brain Tumors.
Pediatric Neurosurgery, 2015Co-Authors: George A. Alexiou, Kalliopi Stefanaki, Amalia Patereli, Georgia Tseka, George Sfakianos, Meropi Tzoufi, Efstathios G Lykoudis, George Vartholomatos, Neofytos ProdromouAbstract:Cell cycle Analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of a modified rapid (within 6 min) cell cycle Analysis protocol for the characterization of malignancy of pediatric brain tumors and for the differentiation of neoplastic from nonneoplastic tissue for possible intraoperative application. We retrospectively studied brain tumor specimens from patients treated at our institute over a 5-year period. All tumor samples were histopathologically verified before flow-cytometric Analysis. The histopathological examination of permanent tissue sections was the gold standard. There were 68 brain tumor cases. All tumors had significantly lower G₀/G1 and significantly higher S phase and mitosis fractions than normal brain tissue. Furthermore low-grade tumors could be differentiated from high-grade tumors. DNA aneuploidy was detected in 35 tumors. A correlation between S phase fraction and Ki-67 index was found in medulloblastomas and anaplastic ependymomas. Rapid cell cycle Analysis by flow cytometry is a promising method for the identification of neoplastic tissue intraoperatively. Low-grade tumors could be differentiated from high-grade tumors. Thus, cell cycle Analysis can be a valuable adjunct to the histopathological evaluation of pediatric brain tumors, whereas its intraoperative application warrants further investigation.
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the value of cell cycle Analysis by propidium iodine staining of cd56 cells in pediatric brain tumors
Clinical Neurology and Neurosurgery, 2015Co-Authors: George Vartholomatos, Kalliopi Stefanaki, Georgia Tseka, George Sfakianos, Meropi Tzoufi, George A. Alexiou, Efstathios G Lykoudis, Neofytos ProdromouAbstract:Abstract Purpose Cell cycle Analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of cell cycle Analysis by propidium-iodine (PI) staining of CD56+ (gated) cells for the characterization of pediatric brain tumor's malignancy. Methods Patients that underwent surgery for an intracranial lesion and tissue sample was available were included in the study. All tumor samples were histopathologically verified before flow cytometric Analysis. Results There were 46 pediatric brain tumor cases. As control we used samples from three cases of brain tissue obtained during surgery for epilepsy. All tumors had significant lower G 0 /G 1 and significant higher S-phase, G 2 /M fraction, S+G 2 /M and S+G 2 /M/G 0 /G 1 -phase fraction than normal brain tissue. Low-grade tumors had significant lower S-phase than high grade tumors. Grade IV tumors had significant lower G 0 /G 1 fraction and higher S+G 2 /M/G 0 /G 1 index than grade III tumors. DNA diploidy was detected in 24 tumors and DNA aneuploidy was detected in 23 tumors. There was a significant correlation between Ki-67 index and both S+G 2 /M and S+G 2 /M/G 0 /G 1 phase fraction. Conclusions Cell cycle Analysis by PI staining of CD56+ cells is a promising method for the assessment of pediatric brain tumors malignancy and could be a valuable adjunct to histopathological evaluation.
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Fast cell cycle Analysis for intraoperative characterization of brain tumor margins and malignancy
Journal of Clinical Neuroscience, 2015Co-Authors: George A. Alexiou, George Vartholomatos, Anna Goussia, Anna Batistatou, Konstantinos I. Tsamis, Spyridon Voulgaris, Athanasios P. KyritsisAbstract:Flow cytometry, although indispensable for the characterization of hematologic malignancies, has not been extensively evaluated in solid tumors. To date intraoperative pathology evaluation of frozen sections of tissue obtained during surgery is the gold standard for intraoperative diagnosis. We investigated the value of a modified rapid protocol for cell cycle Analysis for the intraoperative characterization of intracranial lesions and their surgical margins. We investigated patients who underwent surgery for an intracranial lesion suspicious for a tumor. DNA Analysis and frozen sections were performed on tumor samples that were taken during surgery. Thirty-one patients met the inclusion criteria for the study. There was a significant difference in G0/G1 phase between high-grade and low-grade tumors. Receiver operating characteristic (ROC) Analysis provided 75% of G0/G1 fraction as the optimal cutoff value thresholding the discrimination between low and high-grade tumors. There was a significant difference in S-phase and mitoses fraction between high-grade and low-grade tumors. ROC Analysis indicated 6% of S-phase and 9.7% of mitoses as the optimal cutoff values thresholding the discrimination between these two groups. In the glioblastoma patients, we also analyzed the perilesional tissue and found significant differences between tumor mass and margins regarding the G0/G1 phase, the S-phase and mitoses fraction. In conclusion rapid cell cycle Analysis is a method capable of differentiating low from high-grade tumors and delineating tumor margins in gliomas. Thus, the role of cell cycle Analysis in brain tumors warrants further investigation.
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Correlation of diffusion tensor and dynamic susceptibility contrast MRI with DNA ploidy and cell cycle Analysis of gliomas.
Clinical Neurology and Neurosurgery, 2015Co-Authors: Anastasia K. Zikou, George A. Alexiou, George Vartholomatos, Anna Goussia, Spyridon Voulgaris, Athanasios P. Kyritsis, Vasileios G. Xydis, Paraskevi Kosta, Maria I. ArgyropoulouAbstract:Abstract Objectives Flow cytometry provides a powerful tool to assess cells in G 0 /G 1 , S and G 2 /M phase and ploidy. The purpose of the present study was to investigate the correlation between diffusion tensor (DTI) and dynamic susceptibility contrast (DSC) MRI metrics with cell cycle Analysis findings in gliomas. Patients and methods We studied thirty patients who were operated on for glioma. DTI and DSC MRI were performed within a week prior to surgical excision. Lesion/normal ratios were calculated for the ADC, FA and rCBV. In an excised tumour sample flow cytometric Analysis was performed. Results There were 24 glioblastomas, 2 anaplastic astrocytomas, 1 oligoastrocytoma and 3 diffuse astrocytomas. There were significant differences between low and high-grade gliomas for rCBV and ADC values. Low grade tumours had higher G 0 /G 1 phase fraction and lower S-phase, G 2 /M, S + G 2 /M and S + G 2 /M/G 0 /G 1 fractions There was a significant negative correlation between rCBV and G 0 /G 1 phase fraction and a positive correlation with G 2 /M, S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. Significant correlation was also observed between FA ratio and S + G 2 /M/G 0 /G 1 . There was a negative significant correlation between ADC and S + G 2 /M and the S + G 2 /M/G 0 /G 1 fraction. There were 21 (70%) diploid and 9 (30%) aneuploid tumours. No significant difference was found between diploid and aneuploid tumours with respect to rCBV, ADC and FA values. Conclusion Dynamic susceptibility contrast MRI and diffusion tensor imaging metrics are correlated to tumour aggressiveness as assessed by cell cycle Analysis.
Thomas Lasi - One of the best experts on this subject based on the ideXlab platform.
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label free cell cycle Analysis for high throughput imaging flow cytometry
Nature Communications, 2016Co-Authors: Thomas Lasi, Holge Hennig, Huw D Summers, Fabia J Theis, Joana Cerveira, James O Patterso, Derek Davies, Andrew Filby, Anne E CarpenteAbstract:Imaging flow cytometry combines the high-throughput capabilities of conventional flow cytometry with single-cell imaging. Here we demonstrate label-free prediction of DNA content and quantification of the mitotic cell cycle phases by applying supervised machine learning to morphological features extracted from brightfield and the typically ignored darkfield images of cells from an imaging flow cytometer. This method facilitates non-destructive monitoring of cells avoiding potentially confounding effects of fluorescent stains while maximizing available fluorescence channels. The method is effective in cell cycle Analysis for mammalian cells, both fixed and live, and accurately assesses the impact of a cell cycle mitotic phase blocking agent. As the same method is effective in predicting the DNA content of fission yeast, it is likely to have a broad application to other cell types.