185 research outputs found

    Ga-68 DOTATATE Accumulation in Sarcoidosis

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    We aimed in this case series to show Ga-68 DOTATATE uptake in relation with disease activity in sarcoidosis cases. 8 patients with previous diagnosis of sarcoidosis were included to the study. Ga-68 DOTATATE PET/CT was performed to evaluate of disease activity. Disease activity was described clinically by chest disease specialist by evaluation of lung function tests, serum ACE measurements and thorax CT. Correlation between Ga-68 DOTATATE uptake and disease activity was analyzed. Ga-68 DOTATATE PET/CT as a combination of SSR scintigraphy and anatomical imaging might be beneficial in the evaluation of active sarcoidosis

    Investigation of conduction band structure, electron scattering mechanisms and phase transitions in indium selenide by means of transport measurements under pressure

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    In this work we report on Hall effect, resistivity and thermopower measurements in n-type indium selenide at room temperature under either hydrostatic and quasi-hydrostatic pressure. Up to 40 kbar (= 4 GPa), the decrease of carrier concentration as the pressure increases is explained through the existence of a subsidiary minimum in the conduction band. This minimum shifts towards lower energies under pressure, with a pressure coefficient of about -105 meV/GPa, and its related impurity level traps electrons as it reaches the band gap and approaches the Fermi level. The pressure value at which the electron trapping starts is shown to depend on the electron concentration at ambient pressure and the dimensionality of the electron gas. At low pressures the electron mobility increases under pressure for both 3D and 2D electrons, the increase rate being higher for 2D electrons, which is shown to be coherent with previous scattering mechanisms models. The phase transition from the semiconductor layered phase to the metallic sodium cloride phase is observed as a drop in resistivity around 105 kbar, but above 40 kbar a sharp nonreversible increase of the carrier concentration is observed, which is attributed to the formation of donor defects as precursors of the phase transition.Comment: 18 pages, Latex, 10 postscript figure

    The Role of 18F-Flourodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in Pelvic and Paraaortic Lymph Node Staging of Uterine Cervical Cancer

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    Aim: We aimed to evaluate the sensitivity of 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pelvic and paraaortic lymph node metastases of uterine cervical cancer.  Material and Method: 32 female patients (mean age: 56.1±12.6) who underwent 18F-FDG PET/CT for preoperative staging of uterine cervical cancer between April 2009 and October 2013 were included to the study. Ethical committee approval was taken from Ankara University Medical Faculty Ethics Committee. All the patients had been performed trans-vaginal examination and diagnosed as uterine cervical cancer before 18F-FDG PET/CT. 18F-FDG PET/CT findings were compared with histopathological examination results. Sensitivity, specificity and accuracy of pelvic MRI and 18F-FDG PET/CT were calculated in the detection of pelvic and paraaortic lymph node metastases.  Results: 18F-FDG uptake was seen in primary cervical lesions of all the patients. Mean SUV max of primary cervical lesions was calculated as 13.6±6.6 (range: 6.7-25). In 16 (50%) patients, 18F-FDG uptake was not seen in pelvic and paraaortic lymph nodes. In the remaining patients, 18F-FDG uptake was detected in pelvic nodes in all the patients (50%) and in paraaortic nodes in 6 (18%) patients. Mean SUV max of pelvic lymph nodes were calculated as 8.4±5.2 and of paraaortic lymph nodes 12.45±6.41. 18F-FDG uptake was detected in a total of 47 lymph node stations in 16 patients. Mean SUVmax of all lymph nodes were calculated as 8.9±5.83 (range: 2.6-21.9). According to 18F-FDG PET/CT findings, disease was upstaged from I to IV in 1 (3%) patient, II to III in 2 (6%) patients, III to IV in 1 (3%) patients and I to III in 2 (6%) patients, and down staged from III to I in 1 (3%) patient, respectively. In the patient-based analysis, 18F-FDG PET/CT was TP, TN, FP and FN in 14 (%44), 14 (44%), 2 (6%) and 2 (6%) patients, respectively. Patients based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 87%, 87% and 87%, respectively. In the lesion-based analysis, 18F-FDG PET/CT was TP, FP, TN and FN in 30, 7, 37 and 5 lymph node stations, respectively. Lesion based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 85%, 84% and 84%, respectively.  Conclusion: 18F-FDG PET/CT is a reliable imaging tool with its high sensitivity and specificity in the pelvic and paraaortic lymph node staging of uterine cervical cancer. When performed in the preoperative staging it changes disease stage about in ¼ of patients. In combination of pelvic MRI, primary staging of primary cervical lesions and also pelvic/paraaortic lymph nodes can be done successfully

    The Role of 18F-Flourodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in Pelvic and Paraaortic Lymph Node Staging of Uterine Cervical Cancer

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     Abstract: Aim: We aimed to evaluate the sensitivity of 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pelvic and paraaortic lymph node metastases of uterine cervical cancer.Material and Method: 32 female patients (mean age: 56.1±12.6) who underwent 18F-FDG PET/CT for preoperative staging of uterine cervical cancer between April 2009 and October 2013 were included to the study. Ethical committee approval was taken from Ankara University Medical Faculty Ethics Committee. All the patients had been performed trans-vaginal examination and diagnosed as uterine cervical cancer before 18F-FDG PET/CT. 18F-FDG PET/CT findings were compared with histopathological examination results. Sensitivity, specificity and accuracy of pelvic MRI and 18F-FDG PET/CT were calculated in the detection of pelvic and paraaortic lymph node metastases.Results: 18F-FDG uptake was seen in primary cervical lesions of all the patients. Mean SUV max of primary cervical lesions was calculated as 13.6±6.6 (range: 6.7-25). In 16 (50%) patients, 18F-FDG uptake was not seen in pelvic and paraaortic lymph nodes. In the remaining patients, 18F-FDG uptake was detected in pelvic nodes in all the patients (50%) and in paraaortic nodes in 6 (18%) patients. Mean SUV max of pelvic lymph nodes were calculated as 8.4±5.2 and of paraaortic lymph nodes 12.45±6.41. 18F-FDG uptake was detected in a total of 47 lymph node stations in 16 patients. Mean SUVmax of all lymph nodes were calculated as 8.9±5.83 (range: 2.6-21.9). According to 18F-FDG PET/CT findings, disease was upstaged from I to IV in 1 (3%) patient, II to III in 2 (6%) patients, III to IV in 1 (3%) patients and I to III in 2 (6%) patients, and down staged from III to I in 1 (3%) patient, respectively. In the patient-based analysis, 18F-FDG PET/CT was TP, TN, FP and FN in 14 (%44), 14 (44%), 2 (6%) and 2 (6%) patients, respectively. Patients based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 87%, 87% and 87%, respectively. In the lesion-based analysis, 18F-FDG PET/CT was TP, FP, TN and FN in 30, 7, 37 and 5 lymph node stations, respectively. Lesion based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 85%, 84% and 84%, respectively.Conclusion: 18F-FDG PET/CT is a reliable imaging tool with its high sensitivity and specificity in the pelvic and paraaortic lymph node staging of uterine cervical cancer. When performed in the preoperative staging it changes disease stage about in ¼ of patients. In combination of pelvic MRI, primary staging of primary cervical lesions and also pelvic/paraaortic lymph nodes can be done successfully

    A resampling-based meta-analysis for detection of differential gene expression in breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Accuracy in the diagnosis of breast cancer and classification of cancer subtypes has improved over the years with the development of well-established immunohistopathological criteria. More recently, diagnostic gene-sets at the mRNA expression level have been tested as better predictors of disease state. However, breast cancer is heterogeneous in nature; thus extraction of differentially expressed gene-sets that stably distinguish normal tissue from various pathologies poses challenges. Meta-analysis of high-throughput expression data using a collection of statistical methodologies leads to the identification of robust tumor gene expression signatures.</p> <p>Methods</p> <p>A resampling-based meta-analysis strategy, which involves the use of resampling and application of distribution statistics in combination to assess the degree of significance in differential expression between sample classes, was developed. Two independent microarray datasets that contain normal breast, invasive ductal carcinoma (IDC), and invasive lobular carcinoma (ILC) samples were used for the meta-analysis. Expression of the genes, selected from the gene list for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes were tested on 10 independent primary IDC samples and matched non-tumor controls by real-time qRT-PCR. Other existing breast cancer microarray datasets were used in support of the resampling-based meta-analysis.</p> <p>Results</p> <p>The two independent microarray studies were found to be comparable, although differing in their experimental methodologies (Pearson correlation coefficient, R = 0.9389 and R = 0.8465 for ductal and lobular samples, respectively). The resampling-based meta-analysis has led to the identification of a highly stable set of genes for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes. The expression results of the selected genes obtained through real-time qRT-PCR supported the meta-analysis results.</p> <p>Conclusion</p> <p>The proposed meta-analysis approach has the ability to detect a set of differentially expressed genes with the least amount of within-group variability, thus providing highly stable gene lists for class prediction. Increased statistical power and stringent filtering criteria used in the present study also make identification of novel candidate genes possible and may provide further insight to improve our understanding of breast cancer development.</p

    MED12 Alterations in Both Human Benign and Malignant Uterine Soft Tissue Tumors

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    The relationship between benign uterine leiomyomas and their malignant counterparts, i.e. leiomyosarcomas and smooth muscle tumors of uncertain malignant potential (STUMP), is still poorly understood. The idea that a leiomyosarcoma could derive from a leiomyoma is still controversial. Recently MED12 mutations have been reported in uterine leiomyomas. In this study we asked whether such mutations could also be involved in leiomyosarcomas and STUMP oncogenesis. For this purpose we examined 33 uterine mesenchymal tumors by sequencing the hot-spot mutation region of MED12. We determined that MED12 is altered in 66.6% of typical leiomyomas as previously reported but also in 11% of STUMP and 20% of leiomyosarcomas. The mutated allele is predominantly expressed in leiomyomas and STUMP. Interestingly all classical leiomyomas exhibit MED12 protein expression while 40% of atypical leiomyomas, 50% of STUMP and 80% of leiomyosarcomas (among them the two mutated ones) do not express MED12. All these tumors without protein expression exhibit complex genomic profiles. No mutations and no expression loss were identified in an additional series of 38 non-uterine leiomyosarcomas. MED12 mutations are not exclusive to leiomyomas but seem to be specific to uterine malignancies. A previous study has suggested that MED12 mutations in leiomyomas could lead to Wnt/β-catenin pathway activation however our immunohistochemistry results show that there is no association between MED12 status and β-catenin nuclear/cytoplasmic localization. Collectively, our results show that subgroups of benign and malignant tumors share a common genetics. We propose here that MED12 alterations could be implicated in the development of smooth muscle tumor and that its expression could be inhibited in malignant tumors
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