Computed tomographic characteristics of acute thoracolumbar intervertebral disc disease in dogs.

Forty canine patients with a presumptive diagnosis of the intervertebral disc herniation at the thoracolumbar region were imaged. A neurological examination was performed and all patients were classified under four grades by the examination. The degrees of attenuation of the herniated disc material were measured in Housefield units (HU) in each image. The ratio of the area to herniated disc material and the height to disc material were measured. The clinical grade was correlated with the area ratio of the herniated disc material to the spinal cord, but not correlated with the height ratio of that. In the patients with epidural hemorrhage at surgery, HUs of the herniated disc material was lower than those with no epidural hemorrhage at surgery. Noncontrast computed tomography scans of the spine can be useful in diagnosing acute intervertebral disc disease in chondrodystrophoid breeds, evaluating patient status and identifying concurrent epidural hemorrhage.

Three-dimensional CT angiography of the canine hepatic vasculature.

Eight Beagle dogs were anesthetized and were imaged using a single channel helical CT scanner. The contrast medium used in this study was iohexol (300 mg I/ml) and doses were 0.5 ml/kg for a cine scan, 3 ml/kg for an enhanced scan. The flow rate for contrast material administration was 2 ml/sec for all scans. This study was divided into three steps, with unenhanced, cine and enhanced scans. The enhanced scan was subdivided into the arterial phase and the venous phase. All of the enhanced scans were reconstructed in 1 mm intervals and the scans were interpreted by the use of reformatted images, a cross sectional histogram, maximum intensity projection and shaded surface display. For the cine scans, optimal times were a 9-sec delay time post IV injection in the arterial phase, and an 18-sec delay time post IV injection in the venous phase. A nine-sec delay time was acceptable for the imaging of the canine hepatic arteries by CT angiography. After completion of arterial phase scanning, venous structures of the liver were well visualized as seen on the venous phase.

Expression of membrane type I-matrix metalloproteinase in oral squamous cell carcinoma.

A local invasion and lymph node metastasis (LNM) of an oral squamous cell carcinoma (OSCC) has a poor prognosis, and involves the degradation of the extracellular matrix mediated by multiple proteolytic enzymes including membrane type I-matrix metalloproteinase (MT1-MMP). This study aimed to determine the role of MT1-MMP in OSCC, to evaluate the immunohistochemical expression of MT1-MMP with regard to the invasiveness and LNM of the OSCC, and to evaluate the major source of MT1-MMP mRNA and its protein using immunohistochemistry and in situ hybridization. MT1-MMP expression was examined in 46 OSCCs via immunohistochemistry and non-radioisotope in situ hybridization. The relationship between MT1-MMP expression and LNM, as well as the histological invasiveness, was statistically analyzed. The results showed that whereas 12 out of the 18 OSCCs (66.7%) with LNM showed moderate to strong MT1-MMP expression, only nine of the 28 OSCCs (32.1%) without LNM expressed MT1-MMP strongly. MT1-MMP expression was significantly higher with regard to LNM (P=0.022). As the invasion grade became stronger (from grade a to grade d), MT1-MMP was significantly more strongly expressed (P=0.033). These results suggest that MT1-MMP is primarily secreted in the OSCC cells and is involved in the invasiveness of the OSCC and LNM. Moreover, MT1-MMP combined with other markers may be used to predict the metastatic potential of an OSCC.