Solli P

Experimental Tracheal Transplantation Using a Cryopreserved Aortic Allograft

Background: The tracheal reconstruction after wide resections remains a critical surgical problem. Our aim was to replace trachea with a tissue easy to vascularize, which allows a simple reconstruction and does not require an immunosuppressive regimen. Materials and Methods: A segment of cryopreserved aorta was used in order to verify its adequacy as tracheal substitute. In phase 1, the thoracic aorta of 10 rabbits was excised, obtaining 20 segments that were cryopreserved. Ten segments were implanted in the omentum of 10 rabbits that were sacrificed on postoperative days 7, 14 and 21, and the grafts were examined histologically. In phase 2, a segment of cryopreserved aorta arranged with a silicone prosthesis was transplanted in 10 rabbits and wrapped with omentum. The animals were sacrificed on postoperative days 7, 14 and 21. Results: In phase 1, the neovascularization of the grafts was present after 7 days, and after 14 days the fibroblasts invaded the lumen of the aorta. In phase 2, 8 rabbits survived and the histologic examination after 7, 14 and 21 days showed neovascularization, the absence of rejection and the proliferation of fibroblasts inside the lumen of the aorta; this growth has been restrained by an endoluminal prosthesis. Conclusions: Our study demonstrated that replacing the trachea with cryopreserved aorta is technically feasible and does not evoke immunologic reactions. It requires, however, a silicone tube inside the allograft to limit the colonization of fibroblasts.

Pneumocytes Type II Ultrastructural Modifications after Storage in Preservation Solutions for Transplantation

Although lung transplantation represents a real therapeutic opportunity, the problem of preserving the organ for a prolonged period (> 10 h) still remains unsolved. Further studies are necessary to fully understand the behavior of different lung cell types during the ischemic period. As ultrastructural modifications of cells of lung samples stored in different means of preservation represent an index of the integrity and therefore of cellular viability, in the present work we have compared the time-related ultrastructural changes in human pneumocytes type II cells after hypothermic (10 degrees C) storage for 6 and 12 h in University of Wisconsin (UW) solution and in low potassium dextran (LPD) solution. An ultrastructural grading scale was used to quantify the damage and the results confirmed what was observed microscopically. Statistical analysis (t test) of the data showed that after 6 h in LPD solution, pneumocytes type II were less damaged than those stored in UW solution; these differences were statistically significant (p < 0.05). In our opinion, ultrastructural studies should be considered among the methods presently used to assess the effectiveness of different storage fluids.

Expression of Human CD44v6 in Non-Small-Cell Lung Cancer

Introduction: The CD44 is a membrane glycoprotein that functions as lymph node homing receptor in lymphocyte activation and is involved in homo- and heterotypic cell adhesion. In several tumor cell lines the expression of splice variants (CD44v6 and CD44v7) are correlated with the metastatic potential and confer an advantage in the early steps of the metastatic cascade. In our study we examined 35 cases of non-small-cell lung cancers (NSCLC) in order to detect the presence of CD44v6 and to compare its expression with the histologic type, degree of differentiation, stage of the tumor and survival of the patients. Methods: CD44v6 expression in frozen tissue sections of 35 patients with NSCLC who underwent pneumonectomy or lobectomy was analyzed with the VFF-7 monoclonal antibody that detected the CD44v6 variant. The data on survival were analyzed by the actuarial method and compared by the log rank test. Results: The expression of CD44v6 occurred in all the 20 cases of epidermoid carcinomas tested and in 2 out of the 3 cases of undifferentiated large cell carcinoma and was absent in all the 12 adenocarcinomas. No relationship was found between the presence of this marker and the grading or the stage of the pathology. The 3-year survival rate was 73% for CD44v6-positive and 65% for CD44v6-negative cancer and the comparison was not statistically significant. Conclusion: These results suggest that in lung cancer the expression of CD44v6 is not a useful prognostic factor.

Pneumomediastinum following Politzer's manoeuvre.

drug. We consider that this leaves insufficient time for reliable identification ofthe offending drug or drugs. We agree that the drugs should probably be re-introduced in this order. A further difficult problem is the re-introduction of chemotherapy after an episode of acute liver failure. Certainly it is our policy, as discussed by Mitchell et al, to change to drugs with no history of hepatotoxicity in patients fortunate enough to have survived this complication.