Expression of CD44s, v3 and v6 in Squamous Cell Carcinoma of the Head and Neck / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: CD44 is a transmembrane glycoprotein that mediates cell adhesion through binding to extracelluar matrix molecules such as hyaluronan. Multiple isoforms of CD44 are generated by alternative splicing of 10 separate exons (v1-v10). Some of them have been noted as markers for tumor metastasis and prognosis in several studies. We investigated whether CD44s, v3 and v6 may be a useful markers in the head and neck squamous cell carcinoma. MATERIALS AND METHOD: Paraffin embedded tissue sections, which was diagnosed as squamous cell carcinoma of the head and neck from 41 patients were stained immunohistochemically with monoclonal Ab of CD44s, v3 and v6. The results were compared with the primary tumor status, lymph node metastasis, histopathologic differentiation and survival. RESULTS: Various levels of immunoreactivities of the CD44s, CD44v3 and CD44v6 were detected dominantly in cancer cell membrane. The positive rate of CD44s, CD44v3 and CD44v6 were 59%, 66%, 71%, respectively. The decreased expression of CD44s and CD44v6 was significantly correlated to lymph node metastasis but was not affected by T-stage, histopathologic differentiation and survival. CD44v3 had no correlation with the T-stage, N-stage, pathologic differentiation nor survival. CONCLUSION: The expression of CD44s and CD44v6 in the head and neck squamous cell carcinoma may be a biologic marker for lymph node metastasis.

MR Imaging of Experimental Focal Cerebral Ischemia in Cats: Temporal Evolution of Hyperacute Stroke

PURPOSE: To evaluate the temporal evolution of the ischemic area and trace ratio, and to define ischemic penumbra within the hyperacute experimental focal cerebral ischemia model. MATERIALS AND METHODS: A focal cerebral ischemia model of middle cerebral artery occlusion (MCAO) was constructed in twelve Korean cats weighing 2 -3 Kg. T2-weighted images (T2WI) and diffusion-weighted images(DWI) were obtained using a 1.5T MR imager. Trace images were reconstructed after post-image processing with IDL 5.0. The trace ratio (ipsilateral trace value/contralateral trace value) was calculated in the ischemic core and periphery, and MR images were obtained at 1, 3, 6, and 24 hrs after MCAO. The twelve cats were divided into three groups, and 4, 5, and 3 cats were sacrified after obtaining MR images at 3, 6, and 24 hrs after MCAO, respectively. After 2% triphenyl tetrazolium chloride (TTC) solution and formalin preparation, the infarction area of the brain slice and T2WI and DWI trace images of the same slice were compared. The trace ratio was calculated at the peripheral portion of the ischemic core, which was the presumed ischemic penumbra in images obtained 1hr after MCAO. Changes in trace ratio in the ischemic core and infarction territory were also evaluated according to time. RESULTS: The trace ratio in the peripheral portion of the ischemic core was 0.71 +/- 0.03. The region where the trace ratio was 0.83 +/- 0.06 in images obtained 1 hour after MCAO was presumed to be ischemic penumbra; the region progressed to infarction in images taken during the next time period. In all cases the abnormal area of trace images was larger than that seen on DWI. The trace ratio was lower, by 6.2 %, 3 -6hrs after MCAO than at any other time. In cat number 3, the trace radio decreased rapidly and progressively, by 21%, during the first six hours. For 3 -6hrs after MCAO, the area of infarction showed progressive enlargement. CONCLUSION: Within six hours of MCAO, ischemic penumbra is progressively incorporated into the ischemic core. In the experimental focal cerebral ischemia model, an area of trace ratio larger than 0.71 and less than 1may be defined as ischemic penumbra.