An 11C-labeled selective adenosine A2A antagonist, (E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-[11C]-methylxanthine ([11C]KF17837), was prepared by reaction of (E)-8-(3,4-dimethoxystyryl)-1,3-dipropylxanthine and [11C]methyl iodide with decay-corrected radiochemical yield of 19-50%, radiochemical purity of > 99%, sp. act. of 17-100 GBq/mumol and preparation time of 20-25 min. In mice, the myocardium showed the highest (13.4% ID/g) at 5 min after i.v. injection, which decreased gradually with time. The specific myocardial uptake was visualized by gamma-camera. In the brain region the radioactivity level was higher in the A2A receptors-rich striatum than in the cortex and cerebellum. The specific striatal uptake in rats was clearly demonstrated by PET. These results have shown that [11C]KF17837 is a potential PET radioligand for mapping the adenosine A2A receptors in the heart and brain.

Animals↗

PubMedDate not supplied

Generation of fractal dimension images and its application to automatic edge detection in brain MRI.

We have developed four methods to generate a fractal dimension image and have applied them to the brain MRI. We have adopted four types of scanning methods, "CONVENTIONAL", "OVERLAPPING", "SYMMETRIC" and "FOLDED" to estimate the fractal dimension. The first three methods show almost the same fractal dimension images and their values were between two and three. In the "FOLDED" method, we were able to obtain the images in which the edge of a narrow region including dura and scalp surrounding the brain was selectively enhanced in the T1-weighted MRI. This is found to be a new edge-enhancing filter. We could remove the surrounding structure of the brain by using these filtered images and detect the edge of the brain surface automatically. The brain surface data can be used for various applications such as three-dimensional surface display and registration of inter-modal brain images.

Adult↗

PubMedDate not supplied

The relationship between anterior-posterior knee laxity and the structural properties of the patellar tendon graft. A study in canines.

We studied the relationship between anterior-posterior knee laxity and the structural properties of autogenous patellar tendon grafts used to replace the anterior cruciate ligaments in dogs 1 year after reconstruction. At 30 degrees (full extension for the dog), 60 degrees, and 90 degrees of flexion a significant inverse correlation was found between anterior-posterior knee laxity and the ultimate failure strength of the graft. Likewise, at 60 degrees and 90 degrees of flexion a significant inverse correlation was found between knee laxity and the linear stiffness of the graft. In all cases, as knee laxity increased, the ultimate failure load and linear stiffness values of the graft were found to decrease. There was also a significant increase in anterior-posterior knee laxity of the reconstructed knees (produced by an increase in anterior translation of the tibia relative to the femur) compared with the contralateral control knee. The group of dogs that underwent a sham operation without reconstruction of the anterior cruciate ligament had no change in anterior-posterior knee laxity or the structural properties of the anterior cruciate ligament. The clinical significance of this investigation is that knee laxity measurements demonstrating an increase in anterior translation of the tibia relative to the femur during graft healing may indicate that the graft has weakened and reduced structural properties.

Animals↗

PubMedDate not supplied

Differential expression of RAGE in human pancreatic carcinoma cells.

BACKGROUND/AIMS: Amphoterin is a key protein in normal neurite outgrowth and that its receptor on the cell surface, RAGE, is an important molecule for invasion. RAGE induces neurite outgrowth and regulate gene expression through NF-kappa B. Because the pancreatic cancer shows the constitutively activated NF-kappa B, the involvement of RAGE could be possible as a determinant for the metastatic ability. METHODOLOGY: To see the involvement of RAGE in pancreatic cancer, three representative human pancreatic carcinoma cells were rendered for the study which have different metastatic potential, PANC-1 and MIA PaCa-2 as the cells with high ability, BxPC-3 as those with low. The expression of RAGE (receptor for advanced glycation end-products) was examined by Western blot. RESULTS: The expression of RAGe was strong in MIA PaCa-2 and PANC-1 that have high metastatic ability. On the contrary, RAGE is expressed little in BxPC-3 whose ability is low. CONCLUSIONS: RAGE is expressed in concordant to the metastatic ability of the human pancreatic cancer cells. Control of this molecule could be a key to regulate the metastatic ability of pancreatic cancer.

Blotting, Western↗

PubMedDate not supplied

Minor changes in regional cerebral blood flow revealed by the early distribution of I-123 IMP in brain.

To evaluate the early distribution of I-123 IMP in the brain, 10 dynamic images were obtained in the first 10 minutes after injection using a ring-type SPECT system with a high-sensitivity collimator. In cases of chronic carotid occlusion without brain CT abnormalities, areas of low perfusion were more clearly demonstrated in dynamic images than in static images obtained beginning 20 minutes after injection and continuing for 15 minutes using a high-resolution collimator. In cases of hyperperfusion following infarct or surgery, there was a difference between dynamic and static images in the visualization of hyperemic lesions. The distribution of I-123 IMP in the brain changes gradually, even in the early period after injection, and evaluation of early accumulation is useful for the detection of minor changes in regional cerebral blood flow.

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