Gastric submucosa as the safer and repeatable site for hepatocyte transplantation.

To establish a safe repeatable method for hepatocyte transplantation avoiding serious complications, such as portal thrombosis in the case of the intraportal route of transplantation, we attempted liver cell transplantation into the submucosal layer of the stomach wall. Hepatocytes were isolated from the Lewis rats by a two-step collagenase perfusion method. The final hepatocyte suspension containing 2 x 10(7) viable hepatocytes in 1 mL of 0.2% collagen gel solution. Recipient rats underwent 20% partial hepatectomy and the hepatocyte suspension (2 x 10(7) cells) was injected into the submucosal layer of the anterior wall of the stomach. Rats were humanely killed and histologically examined at days 1, 3, 7, 30, or 180. Most transplanted hepatocytes remained in the submucosal layer until day 7. The surviving hepatocytes were arranged in clusters in the submucosa on day 30; 5-bromo-2'-deoxy-uridine (BrdU)-positive cells were observed. Also, the function of glycogen storage was detected by Periodic acid-Schiff (PAS) reactions on days 7, 30, and 180. The transplanted hepatocytes proliferated, reconstructing liver tissue-like structures in the gastric submucosa on day 180. The gastric submucosa is easily, repeatedly accessible by the gastro-endoscope. Thus, these results suggest that the gastric submucosa is a possible site for safe repetitions hepatocyte transplantation using endoscopic injection.

[Activities of thymidylate synthase and dihydropyrimidine dehydrogenase in patients with colorectal cancer].

Between 1998 and 2001, 82 colorectal cancers were resected in our hospital. The activities of TS and DPD were evaluated. TS activities in tumor tissues were significantly higher than in normal tissue, but the DPD activities had no significant difference between them. TS and DPD showed a correlation between normal and tumor tissues in stage III or IV patients. The TS value of patients with recurrence tended to be higher than that of patients with no recurrence. Especially in stage I or II patients with recurrence, who were administered 5-FU before recurrence, the TS value was significantly higher than in non-treated patients. In stage III or IV patients, it was considered that DPD prevention was important for 5-FU to effectively prevent TS. The TS value might be a new prospective risk factor for recurrence. Moreover, TS and DPD would be the index of biological malignancy.

Hypoxic conditions restore lost sensitivity to the growth inhibitory effect of transforming growth factor beta-1 (TGF beta-1) in proliferating rat hepatocytes in vitro.

TGF beta-1 is known to be a growth inhibitor of regenerating liver, and an inducer of hepatocyte apoptosis in primary culture. However, hepatocytes can proliferate after partial hepatectomy even at high serum TGF beta-1 concentrations. In this study we used the primary cultures of rat hepatocytes for 10 days to investigate how TGF beta-1 affects proliferating hepatocytes. DNA synthesis peaked on day 8 of culture, and TGF beta-1-induced apoptosis was significantly suppressed on day 8 compared to days 2, 5, and 10. Flow-cytometric analysis revealed that hepatocytes that had incorporated BrdU were resistant to the apoptotic effect of TGF beta-1, and Northern blot analysis showed that TGF beta receptor mRNA was down-regulated on day 8. Hypoxic conditions restores TGF beta receptor mRNA expression and the lost sensitivity of proliferating hepatocyte to TGF beta-1.

[Long-term complete response in two cases of liver metastases from rectal and gastric cancer treated with intra-arterial infusion chemotherapy of leucovorin and 5-fluorouracil].

Intra-arterial infusion chemotherapy combined with leucovorin (LV) and 5-fluorouracil (5-FU) was performed in two patients with multiple metastases from rectal and gastric cancer. In each patient LV 45 mg was infused as a bolus just before and after 5-FU 1,000 mg/4 hrs administration. Thereafter 5-FU dose was decreased gradually. This regimen was principally repeated weekly on an outpatient basis. In both patients PR was detectable 3 and 4 months after the beginning of chemotherapy, and CR was obtained in 21 and 6 months, respectively. Neither patient showed any signs of recurrence and are in good health 35 and 30 months after initiation of chemotherapy. These findings suggest that our protocol has an excellent anti-tumor effect and improves the QOL in some patients for a long time.

Recovery of the contact site A glycoprotein of Dictyostelium discoideum from sodium dodecyl sulfate-polyacrylamide gel and characteristics of monoclonal antibodies against the recovered protein.

Monoclonal antibodies were produced against a cell-cell adhesion (contact site A) glycoprotein of Dictyostelium discoideum, isolated by preparative gel electrophoresis. The glycoprotein was recovered by electroelution from a polyacrylamide gel strip and used for the production of monoclonal antibodies. Four of the five antibodies obtained bound specifically to the protein moiety of the contact site A glycoprotein. The specificities of the antibodies were in striking contrast to those of antibodies raised against the contact site A glycoprotein purified by Triton X-114 phase separation and DEAE chromatography. The majority of the latter antibodies recognized the carbohydrate moiety of the contact site A glycoprotein and cross-reacted heavily with other membrane glycoproteins.