Influence of the tibial stem design on bone density after cemented total knee arthroplasty: a prospective seven-year follow-up study.

We prospectively measured the changes in bone mineral density (BMD) in the proximal tibia of 20 total knee arthroplasties, ten with cruciform stems and ten with cylindrical stems. The measurements were made one, four and seven years after surgery. We observed a uniform density decrease in three regions of interest from one to seven years of follow-up. Cylindrical stems showed an asymmetrical density decrease between the three regions of interest, with no change in the central region, a slight decrease in the lateral region, and large decrease in the medial region. Multivariate analysis with general linear model showed the stem type factor as statistically significant for medial region of interest (p = 0.006). The cylindrical stem produces heterogeneous BMD changes under the tibial platform in knee arthroplasties, and this could be a potential risk factor for asymmetrical subsidence of this component.

Collagenase-3 (MMP-13) expression by inflamed mucosa in inflammatory bowel disease.

OBJECTIVE: To determine whether the expression of collagenase-3 (MMP-13) in biopsies from patients with inflammatory bowel disease is correlated with histological inflammation parameters. MATERIAL AND METHODS: Fifty-nine patients with inflammatory bowel disease were included in the study. The control group comprised 20 patients free of inflammatory disease and ten patients with acute diverticulitis. MMP-13 expression was determined by immunohistochemical staining and the specimens were assigned a histological inflammation score. RESULTS: It was found that 62.8% of patients with ulcerative colitis (UC) and 54.1% of patients with Crohn's disease (CD) showed MMP-13-positive immunostaining in biopsies from affected areas. MMP-13-positive staining was more intense in ulcerated colonic mucosa. A positive and significant correlation was found between MMP-13 expression and the histological inflammation scores in mucosal samples from patients with CD (r = 0.74, p < 0.0001) or UC (r = 0.62, p < 0.0001). However, no MMP-13-positive immunostaining was found in either the biopsy specimens of the control group or those biopsies taken from patients with UC or CD in microscopically confirmed non-affected areas of the colonic mucosa. Similarly, colonic mucosa samples of the 10 patients with acute diverticulitis did not show immunostaining for MMP-13. CONCLUSIONS: Our findings demonstrating the absence of MMP-13 expression in non-inflamed colonic mucosa or in acute diverticulitis, as well as a positive correlation between elevated MMP-13 expression and histological criteria of inflammation in patients with inflammatory bowel diseases (CD and UC) suggest a role of the protease in the pathogenesis of these latter processes.

Expression and clinical significance of CD44V5 and CD44V6 in resectable colorectal cancer.

PURPOSE: This study was conducted to evaluate the prognostic significance of CD44v5 and CD44v6 in resectable colorectal cancer. MATERIALS AND METHODS: Membranous CD44v5 and CD44v6 levels were measured by an immunoenzymatic assay in tumors and surrounding mucosal samples obtained from 105 patients with resectable colorectal carcinomas. RESULTS: There were no significant differences of CD44v5 levels between tumors [median: 3.2 (range: 0.9-83.5) ng/mg protein) and surrounding mucosal samples (3 (3-146.2) ng/mg protein]. However, tumor samples showed significantly higher CD44v6 levels [19.5 (2.2-562.9) ng/mg protein] than mucosal samples [5 (5-230) ng/mg protein] (P=0.0001). Patients with higher CD44v5 or CD44v6 content in tumor samples had a considerably shorter relapse-free survival (P<0.05, for both). Patients with a higher CD44v6 content also had a shorter relapse-free and overall survival in the multivariate analysis (P<0.05). CONCLUSION: The results of this study suggest a role of CD44v5 and CD44v6 in colorectal cancer progression. Membranous CD44v levels in primary tumors, measured by immunoenzymatic assay, may contribute to a more precise prognostic estimation in patients with resectable colorectal cancer.

CD44s expression in resectable colorectal carcinomas and surrounding mucosa.

BACKGROUND: CD44s (standard isoform) is a cell adhesion molecule belonging to the family of the hyaluronan-binding proteins. The CD44 family has been found to be overexpressed in epithelial tumors, where they are generally in relationship with tumor growth and metastasic properties. The aim of this work was to evaluate the membranous CD44s content in colorectal cancer and in healthy surrounding mucosa, its possible relationship with clinicopathological parameters, and its potential prognostic significance. MATERIALS AND METHODS: Membranous CD44s levels were measured by an immunoenzymatic assay in tumors and surrounding mucosa samples from 72 patients with resectable colorectal carcinomas. The patients were followed for a mean time period of 30 months. RESULTS: There was a wide variability of CD44s levels in tumor-surrounding mucosal samples (26.6-727 ng/mg protein) as well as in tumors (28.5-381 ng/mg protein). Tumor samples showed significantly higher CD44s levels (median: 99.1 ng/mg protein) than surrounding mucosal samples (81 ng/mg protein) (p=0.03). In the same way, CD44s levels in tumors as well as in surrounding mucosal samples were significantly higher in high S-phase tumors than in low S-phase tumors (p=0.001 for both). There was no significant relationship between tumor CD44s levels and patient's outcome. However, high levels of the glycoprotein in nonneoplastic surrounding mucosa were significantly (p=0.018) associated with a poor overall patient survival. CONCLUSION: CD44s may play a role in the tumorogenesis of colorectal carcinomas. In addition, CD44s levels in tumor-surrounding mucosa may provide, in concert with some clinicopathological parameters, important information about prognostic evaluation of patients with resectable colorectal carcinomas.