AIM: To study short ds RNA oligonucleotides(si RNA)as a potent tool for artificially modulating gene expression of N-Myc down regulated gene 1(NDRG1) gene induced under different physiological conditions(Normoxia and ...AIM: To study short ds RNA oligonucleotides(si RNA)as a potent tool for artificially modulating gene expression of N-Myc down regulated gene 1(NDRG1) gene induced under different physiological conditions(Normoxia and hypoxia) modulating NDRG1 transcription, m RNA stability and translation. METHODS: A cell line established from a patient with glioblastoma multiforme. Plasmid DNA for transfections was prepared with the Endofree Plasmid Maxi kit. From plates containing 5 × 107 cells, nuclear extracts were prepared according to previous protocols. The p SUPERNDRG1 vectors were designed, two sequences were selected from the human NDRG1 c DNA(5'-GCATTATTGGCATGGGAAC-3' and 5'-ATGCAGAGTAACGTGGAAG-3'. reverse transcription polymerase chain reaction was performed using primers designed using published information on β-actin and hypoxia-inducible factor(HIF)-1α m RNA sequences in Gen Bank. NDRG1 m RNA and protein level expression results under different conditions of hypoxia or reoxygenation were compared to aerobic control conditions using the Mann-Whitney U test. Reoxygenation values were also compared to the NDRG1 levels after 24 h of hypoxia(P < 0.05 was considered significant).RESULTS: si RNA- and iodoacetate(IAA)-mediated downregulation of NDRG1 m RNA and protein expression in vitro in human glioblastoma cell lines showed a nearly complete inhibition of NDRG1 expression when compared to the results obtained due to the inhibitory role of glycolysis inhibitor IAA. Hypoxia responsive elements bound by nuclear HIF-1 in human glioblastoma cells in vitro under different oxygenation conditions and the clearly enhanced binding of nuclear extracts from glioblastoma cell samples exposed to extreme hypoxic conditions confirmed the HIF-1 Western blotting results. CONCLUSION: NDRG1 represents an additional diagnostic marker for brain tumor detection, due to the role of hypoxia in regulating this gene, and it canrepresent a potential target for tumor treatment in human glioblastoma. The si RNA method can represent an elegant alt展开更多
Purpose: To compare target dose distribution and dose to normal tissue for brain tumors using intensity-modulated and three-dimensional conformal radiotherapy. Methods and Materials: Twelve patients selected in the pr...Purpose: To compare target dose distribution and dose to normal tissue for brain tumors using intensity-modulated and three-dimensional conformal radiotherapy. Methods and Materials: Twelve patients selected in the present study compared the dosimetry of intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT) techniques in patients treated with different diagnosis brain tumor. All patients underwent computed tomography planning in conjunction with magnetic resonance imaging fusion. Prescription dose and normal-tissue constraints were identical for both plans. The tolerance level for maximum dose was 6.0 Gy for lenses and 54.0 Gy for brain stem, and optical nerves. Target coverage was evaluated with the D98%, D95% and D2%. Normal tissue dose was evaluated with the maximum dose to lenses, brain stem, and optical nerves. Results: Mean and standard deviation values of PTV 98%, PTV 95% and PTV 2% in IMRT these values were 94.6 ± 2.3, 96.56 ± 1.67 and 106.5 ± 1.87 respectively;for 3DCRT were 92.7 ± 3.09, 95.58 ± 1.24 and 104.45 ± 2.73 respectively. IMRT plan provided reduced dose to brainstem (72.17 ± 29.967) and lenses (2.43 ± 2.39) relative to the 3DCRT plans for brainstem (73.05 ± 34.59) and lenses (7.65 ± 23.24). But optic nerves with IMRT significantly received higher doses (38.86 ± 32.15) than 3D-CRT (27.57 ± 31.45). Conclusion: Dose coverage of the planning target volume (PTV) and organ at risk (OAR) was better with IMRT. If PTV is distant to optical nerves and brainstem 3DCRT technique can be applied, and if the PTV is nearby OAR intensity-modulated treatment technique should be used.展开更多
A brain tumor is a mass of abnormal cells in the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). Conventional diagnosis of a brain tumor by the radiologist is done by examining a set of imag...A brain tumor is a mass of abnormal cells in the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). Conventional diagnosis of a brain tumor by the radiologist is done by examining a set of images produced by magnetic resonance imaging (MRI). Many computer-aided detection (CAD) systems have been developed in order to help the radiologists reach their goal of correctly classifying the MRI image. Convolutional neural networks (CNNs) have been widely used in the classification of medical images. This paper presents a novel CAD technique for the classification of brain tumors in MRI images. The proposed system extracts features from the brain MRI images by utilizing the strong energy compactness property exhibited by the Discrete Wavelet Transform (DWT). The Wavelet features are then applied to a CNN to classify the input MRI image. Experimental results indicate that the proposed approach outperforms other commonly used methods and gives an overall accuracy of 99.3%.展开更多
This paper presents a dynamic image approach to characterize the growth of brain cancer invasion of tumor gliomas cells using singular value decomposi-tion (SVD) technique. Such a dynamic image is identi-fied by the w...This paper presents a dynamic image approach to characterize the growth of brain cancer invasion of tumor gliomas cells using singular value decomposi-tion (SVD) technique. Such a dynamic image is identi-fied by the white and grey matter displayed by mag-netic resonance (MR) images of the patient brain taken at different times. SVD components and prop-erties have been analyzed for different brain images. It is figured out that the growth of tumor cells is quantized by the SVD eigenvalues. Since SVD geo-metrically interprets an ellipsoid transformation, then the higher the eigenvalues, the more of tumor growth is. In vivo SVD dynamic imaging offers a more pre-dictive model to assess the tumor therapy than con-ventional technologies. Furthermore, an efficient dy-namic white-black indicator of the tumor growth rate is constructed based on the change in the diagonal eigenvalues matrices of two MR images taken at dif-ferent times. Finally, SVD image processing results are demonstrated to verify the effectiveness of the applied approach that can be implemented for each individual patient.展开更多
基金Supported by Deutsche Forschungsgemeinschaft DFG,VO 871/2-3,to Vordermark Dthe IZKF Würzburg,B25,to Hagemann C
文摘AIM: To study short ds RNA oligonucleotides(si RNA)as a potent tool for artificially modulating gene expression of N-Myc down regulated gene 1(NDRG1) gene induced under different physiological conditions(Normoxia and hypoxia) modulating NDRG1 transcription, m RNA stability and translation. METHODS: A cell line established from a patient with glioblastoma multiforme. Plasmid DNA for transfections was prepared with the Endofree Plasmid Maxi kit. From plates containing 5 × 107 cells, nuclear extracts were prepared according to previous protocols. The p SUPERNDRG1 vectors were designed, two sequences were selected from the human NDRG1 c DNA(5'-GCATTATTGGCATGGGAAC-3' and 5'-ATGCAGAGTAACGTGGAAG-3'. reverse transcription polymerase chain reaction was performed using primers designed using published information on β-actin and hypoxia-inducible factor(HIF)-1α m RNA sequences in Gen Bank. NDRG1 m RNA and protein level expression results under different conditions of hypoxia or reoxygenation were compared to aerobic control conditions using the Mann-Whitney U test. Reoxygenation values were also compared to the NDRG1 levels after 24 h of hypoxia(P < 0.05 was considered significant).RESULTS: si RNA- and iodoacetate(IAA)-mediated downregulation of NDRG1 m RNA and protein expression in vitro in human glioblastoma cell lines showed a nearly complete inhibition of NDRG1 expression when compared to the results obtained due to the inhibitory role of glycolysis inhibitor IAA. Hypoxia responsive elements bound by nuclear HIF-1 in human glioblastoma cells in vitro under different oxygenation conditions and the clearly enhanced binding of nuclear extracts from glioblastoma cell samples exposed to extreme hypoxic conditions confirmed the HIF-1 Western blotting results. CONCLUSION: NDRG1 represents an additional diagnostic marker for brain tumor detection, due to the role of hypoxia in regulating this gene, and it canrepresent a potential target for tumor treatment in human glioblastoma. The si RNA method can represent an elegant alt
文摘Purpose: To compare target dose distribution and dose to normal tissue for brain tumors using intensity-modulated and three-dimensional conformal radiotherapy. Methods and Materials: Twelve patients selected in the present study compared the dosimetry of intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT) techniques in patients treated with different diagnosis brain tumor. All patients underwent computed tomography planning in conjunction with magnetic resonance imaging fusion. Prescription dose and normal-tissue constraints were identical for both plans. The tolerance level for maximum dose was 6.0 Gy for lenses and 54.0 Gy for brain stem, and optical nerves. Target coverage was evaluated with the D98%, D95% and D2%. Normal tissue dose was evaluated with the maximum dose to lenses, brain stem, and optical nerves. Results: Mean and standard deviation values of PTV 98%, PTV 95% and PTV 2% in IMRT these values were 94.6 ± 2.3, 96.56 ± 1.67 and 106.5 ± 1.87 respectively;for 3DCRT were 92.7 ± 3.09, 95.58 ± 1.24 and 104.45 ± 2.73 respectively. IMRT plan provided reduced dose to brainstem (72.17 ± 29.967) and lenses (2.43 ± 2.39) relative to the 3DCRT plans for brainstem (73.05 ± 34.59) and lenses (7.65 ± 23.24). But optic nerves with IMRT significantly received higher doses (38.86 ± 32.15) than 3D-CRT (27.57 ± 31.45). Conclusion: Dose coverage of the planning target volume (PTV) and organ at risk (OAR) was better with IMRT. If PTV is distant to optical nerves and brainstem 3DCRT technique can be applied, and if the PTV is nearby OAR intensity-modulated treatment technique should be used.
文摘A brain tumor is a mass of abnormal cells in the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). Conventional diagnosis of a brain tumor by the radiologist is done by examining a set of images produced by magnetic resonance imaging (MRI). Many computer-aided detection (CAD) systems have been developed in order to help the radiologists reach their goal of correctly classifying the MRI image. Convolutional neural networks (CNNs) have been widely used in the classification of medical images. This paper presents a novel CAD technique for the classification of brain tumors in MRI images. The proposed system extracts features from the brain MRI images by utilizing the strong energy compactness property exhibited by the Discrete Wavelet Transform (DWT). The Wavelet features are then applied to a CNN to classify the input MRI image. Experimental results indicate that the proposed approach outperforms other commonly used methods and gives an overall accuracy of 99.3%.
文摘This paper presents a dynamic image approach to characterize the growth of brain cancer invasion of tumor gliomas cells using singular value decomposi-tion (SVD) technique. Such a dynamic image is identi-fied by the white and grey matter displayed by mag-netic resonance (MR) images of the patient brain taken at different times. SVD components and prop-erties have been analyzed for different brain images. It is figured out that the growth of tumor cells is quantized by the SVD eigenvalues. Since SVD geo-metrically interprets an ellipsoid transformation, then the higher the eigenvalues, the more of tumor growth is. In vivo SVD dynamic imaging offers a more pre-dictive model to assess the tumor therapy than con-ventional technologies. Furthermore, an efficient dy-namic white-black indicator of the tumor growth rate is constructed based on the change in the diagonal eigenvalues matrices of two MR images taken at dif-ferent times. Finally, SVD image processing results are demonstrated to verify the effectiveness of the applied approach that can be implemented for each individual patient.
