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ABSTRACT: The in vivo temporal changes of luciferase activity were investigated under the control of an hsp70 promoter in three tumour models after the application of different intensities of high-intensity focused ultrasound (HIFU). Three cell lines, SCCVII, NIH3T3 and M21 were stably transfected with a plasmid containing the hsp70 promoter and luciferase reporter gene, and tumours were subcutaneously initiated into mice. At a size of 1300 ± 234 mm(3), the tumours were exposed to five intensities of continuous HIFU (802-1401-2157-3067-4133 W/cm(2)) for 20 sec. Bioluminescence and MR imaging were performed to assess luciferase activity and signal intensity changes in the tissue. The MRI scan protocol was pre- and post-contrast T1-wt-SE, T2-wt-FSE, DCE-MRI, diffusion-wt STEAM sequence, T2 relaxation time determination obtained on a 1.5-T GE MRI scanner. The NIH3T3 tumours showed the highest luciferase activity of 328.1 ± 7.1 fold at 24 h at a HIFU intensity of 3067 W/cm(2), the M21 tumours of 3.2 ± 0.6 fold 8 hours and the SCCVII tumours 2.9 ± 0.9 fold 4 hours post-HIFU at 2157 W/cm(2). The greatest increase in T2 signal intensity and T2 relaxation time of 20.7 ± 3.4% was seen in the SCCVII tumours. The highest contrast medium uptake of 10.1 ± 1.1% was noted in the M21 tumours, and 14.8 ± 1.9% in the SCCVII tumours. In all tumours, a significant increase in the diffusion coefficient was seen with increased HIFU intensity, the highest of which was 40.3 ± 4.1% in the SCCVII tumours. The three tumour cell lines stably transfected with the hsp70/luciferase gene showed differential luciferase activity, which peaked at different times after the application of HIFU and was dependant on tumour type and HIFU energy deposition.
Technology in cancer research & treatment 04/2011; 10(2):197-210. · 2.02 Impact Factor
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RöFo - Fortschritte auf dem Gebiet der R 02/2008; 180(1):57-9. · 2.76 Impact Factor
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ABSTRACT: Endoscopic retrograde cholangiopancreaticography (ERCP) is the morphologic gold standard for the diagnosis of chronic pancreatitis. Magnetic Resonance Imaging (MRI) enables the visualization of not only the pancreatic duct but also the surrounding parenchyma using T2- and T1-weighted sequences before and after the application of a contrast agent. Moreover, it allows the depiction of ductal segments distal to a stenosis or occlusion. However, conventional Magnetic Resonance Cholangiopancreaticography (MRCP) was not able to achieve accuracy similar to that of ERCP. Despite many technological innovations, such as fast breath-hold acquisitions or respiratory-gated 3D sequences, this drawback could not be overcome. In recent years, secretin-enhanced MRCP has been used for the diagnosis of chronic pancreatitis. A recent study showed that secretin not only improves the visibility of the pancreatic duct and its side branches but it also enhances the diagnostic accuracy of MRCP. The sensitivity, specificity, and positive and negative predictive values were improved by the application of secretin. Moreover, the agreement between independent observers increased after the use of secretin. In addition, quantitative post-processing tools have been developed that enable the measurement of the exocrine pancreatic output non-invasively using secretin-enhanced MRCP. These tools facilitate applications, such as functional follow-up after pancreaticogastrostomy and pancreaticogastric anastomoses, evaluation of the functional status of the graft after pancreas transplantation and follow-up of pancreatic drainage procedures and duct disruption.
RöFo - Fortschritte auf dem Gebiet der R 09/2007; 179(8):790-5. · 2.76 Impact Factor
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ABSTRACT: A 41-year-old man with known Klippel-Trenaunay syndrome was admitted to hospital because of progressive dyspnea on exertion. Examination on admission revealed the typical signs of Klippel-Trenaunay syndrome, predominantly of the left leg.
D-dimers were significantly increased. Contrast-enhanced computed tomography of the chest revealed multiple small pulmonary arterial emboli in subsegmental arteries on both lungs. Pulmonary arterial digital subtraction angiography revealed extensive peripherally localized perfusion defects. Pulmonary artery pressure measurement demonstrated bilateral pulmonary artery hypertension. Phlebography of the left lower leg showed marked varices in the calf. There was also a persisting sciatic vein.
The recurrent peripheral pulmonary emboli with pulmonary arterial hypertension was a complication of a Klippel-Trenaunay syndrome. Another rare entity of this syndrome was a persisting sciatic vein. Heparinization was initiated, followed by oral anticoagulation. As the patient had not been anticoagulated before, implantation of an inferior vena cava filter was not deemed appropriate.
Recurrent peripheral pulmonary emboli leading to chronic pulmonary artery hypertension is a rare but typical complication of Klippel-Trenaunay syndrome. Early recognition of this syndrome and any complications as a separate entity, as well as initiation of therapeutic measures, like anticoagulation or early pulmonary thrombendarterectomy for chronic pulmonary artery emboli, are of prognostic importance.
DMW - Deutsche Medizinische Wochenschrift 05/2006; 131(15):811-4. · 0.53 Impact Factor
