We manufactured an esophageal prosthesis made of a collagen sponge supported by an inner silicone tube. The collagen was derived from porcine skin and was crosslinked by dehydrothermal treatment. We implanted our prosthesis in nine dogs after resecting a 5 cm length of the thoracic esophagus. Intravenous hyperalimentation was performed for 4 weeks after the surgery. After 29 days, the inner silicone tube was removed endoscopically and oral feeding was restarted immediately. All nine dogs survived more than 1 month, and three of the nine dogs survived for more than 1 year. Endoscopically, the luminal surface of the regenerated esophagus was covered with a lustrous, smooth mucosa, but stenosis was observed in the midregion of the regenerated esophagus. Microscopically, no foreign material remained at the reconstructed site 1 month after surgery; the collagen sponge was absorbed and replaced by host tissue. Complete epithelization was observed within 3 months. Regeneration of the lamina muscularis mucosae, esophageal glands, and skeletal muscle were observed near the anastomoses. Our artificial esophagus holds promise for esophageal reconstruction in a clinical setting, even in the thorax.

Animals↗

PubMedDate not supplied

Intrathoracic esophageal replacement with a collagen sponge--silicone double layer tube: evaluation of omental-pedicle wrapping and prolonged placement of an inner stent.

In a previous study, we replaced a 5 cm gap created in the canine intrathoracic esophagus with an artificial esophagus. However, although newly formed esophageal tissue subsequently bridged the gap, mild stenosis occurred, and this seemed to be caused by inadequate regeneration of the skeletal muscle. In the present study, we evaluated whether omental pedicle wrapping (OMPx) of the prosthesis could promote tissue regeneration and whether prolonged retention of the silicone tube within the prosthesis could prevent stenosis. A gap was created in 14 dogs, and the defect was repaired by our prosthesis. OMPx was performed in 5 of the 14 dogs (OMPx group) but not in the rest (control group). The silicone tube was retained for 4 weeks in the control group and for 8 weeks in the OMPx group. All of the dogs in the control group survived for more than 3 months, except for those that were killed. Four dogs in the OMPx group died within 3 months, one caused by perforation at 7 months. Only the thin epithelial and submucosal layer regenerated in the OMPx group. OMPx is not effective for promoting tissue regeneration, and prolonged retention of the silicone tube interrupts epithelial regeneration.

Animals↗

PubMedDate not supplied

Effect of immune complexes in serum from patients with rheumatoid vasculitis on the expression of cell adhesion molecules on polymorphonuclear cells.

OBJECTIVE: Immune complexes (IC) are frequently detected in patients with rheumatoid vasculitis (RV). To explore the pathogenic role of IC in the development of vasculitis among patients with rheumatoid arthritis (RA), we examined the effect of IC on the expression of cell adhesion molecules (CAM) on polymorphonuclear cells (PMN). METHODS: PMN from healthy volunteers were incubated with the sera from 26 patients with RA including 9 patients with RV, and the expression of CAM on the PMN was assessed by flow cytometry. RESULTS: We found that 67% (6/9) of the serum samples from RV patients and 18% (3/17) of the samples from RA patients without RV revealed up-regulated CD11b expression. On the other hand, 89% (8/9) of the samples from RV patients and 12% (2/17) of the samples from RA patients without RV revealed up-regulated CD18 expression. However, the expression of CD11a was not affected. Up-regulation of CD11b and CD18 on PMN was also induced by the immunoglobulin G (IgG) fraction of the sera of RV patients. Moreover, L-selectin expression on PMN was down-regulated by the sera or IgG of some patients with RV. These changes in CAM expression on PMN induced by IgG of RV patients were not observed when PMN were incubated with the IgG of RV patients from which the IC formed by IgG had been removed. CONCLUSION: These results suggest that IC formed by IgG in patients with RA are involved in the development of vasculitis by affecting the expression of CAM on PMN.

Adult↗