Establishment of a mdr1 Multidrug Resistant Model of Orthotopic Transplantation of Liver Carcinoma on Nude Mice

To develop a new method of inducing mdrl multidrug resistance by establishinga nude mice model of orthotopic transplantation of liver carcinoma by sporadic abdominalchemotherapy at intervals. Methods: Hepatocellular carcinoma HepG2 cell was cultured and injectedsubcutaneously to form the tumor-supplying mice. The tumor bits from the tumor-supplying mice wereimplanted under the envelope of the mice liver and induced by abdominal chemotherapy withPharmorubicin. Physical examination, ultrasonography, spiral CT and operative inspection were usedto examine tumor progression. RT-PCR and immunohistochemistry were adopted to detect the expressionof mdr1-mRNA and its encoded protein P-gp protein (P-gp). Results: There was no operative dead, therate of implanting tumor successfully was 88% (22/25), the rate of implanting secondly successfullywas 100% (3/3), and the rate of inducing successfully was 80% (16/20). The expression of mdrl-mRNAand the P-gp in the inducing group was 23 folds and 13 folds in the control group respectively.Conclusion: We have established an in vivo model of mdr using nude mice transplanted with orthotopicliver neoplasm coupled to chemotherapy.

Orthotopic liver transplantation as a rescue operation for recurrent hepatocellular carcinoma after partial hepatectomy

AIM: To compare post-orthotopic liver transplantation (OLT) survival between patients with recurrent hepatocellular carcinoma (HCC) after partial hepatectomy and those who received de novo OLT for HCC and to assess the risk factors associated with post-OLT mortality. METHODS: From July 2003 to August 2005, 77 consecutive HCC patients underwent OLT, including 15 patients with recurrent HCC after partial hepatectomy for tumor resection (the rescue OLT group) and 62 patients with de novo OLT for HCC (the de novo OLT group). Thirty-three demographic, clinical, histological, laboratory, intra-operative and post-operative variables were analyzed. Survival was calculated by the Kaplan- Meier method. Univariable and multivariable analyses were also performed. RESULTS: The median age of the patients was 49.0 years. The median follow-up was 20 mo. Three patients (20.0%) in the rescue OLT group and 15 patients (24.2%) in the de novo OLT group died during the follow-up period (P = 0.73). The 30-day mortality of OLT was 6.7% for the rescue OLT group vs 1.6% for the de novo OLT group (P = 0.27). Cox proportional hazards model showed that pre-OLT hyperbilirubinemia, the requirement of post-OLT transfusion, the size of the tumor, and family history of HCC were significantly associated with a higher hazard for mortality. CONCLUSION: There are no significant differences in survival/mortality rates between OLT as de novo therapy and OLT as a rescue therapy for patients with hcc. Pre-OLT hyperbilirubinemia, post-OLT requirement of transfusion, large tumor size and family history of HCC are associated with a poor survival outcome.

Gut perforation after orthotopic liver transplantation in adults

AIM： To describe cases of gut perforation after orthotopic liver transplantation.METHODS： Data were colleted from our center database and medical records. Six of 187 patients （3.2%）who underwent orthotopic liver transplantation from January to December 2005 developed gut perforation.All patients were male with an average age of 46 years.Modified piggyback liver transplantation was performed at the Organ Transplantation Center, First Affiliated Hospital, Sun Yat-Sen University.RESULTS： Previous operation, steroid therapy, and prolonged portal venous cross clamp time, poor nutritional status and iatrogenic injury were found to be its ecological factors. The patients with gut perforation were found to have fever, increased leukocytes, mild abdominal pain and tenderness. The median portal venous clamp time was 63 min （range 45-72 min）,median cold ischaemia time was 11.3 h （range 7-15 h）.Median intraoperative blood loss was 500 mL （range 100-1200 mL） and median operation time was 8.8 h （range 6-12 h）. None of the six patients developed acute cellular rejection. White cell count was above 18 × 10^9/L in five patients （neutrophilic leukocytes were above 90%） and 1.5 × 10^9/L in one patient. Bacterial culture in drainage liquid revealed enterococci in five patients. Of the 6 patients undergoing orthotopic liver transplantation, 3 survived and 3 died after modified piggyback liver transplantation.CONCLUSION： Gut perforation occurs after orthotopic liver transplantation in adults. A careful and minimal dissection during OLT, longer retention of the stomach tube, and reducing the portal clamp time and steroid dose should be taken into consideration. If gut perforation is not prevented, then early diagnosis,preferably through detection of enterococci may ensure better survival.

The precursor frequency of alloreactive CTLs is proportional to the number of T cell epitope specificities

The aim of this study is to find the experimental evidence that the precursor frequency of alloreactive CTLs is proportional to the number of the T-cell epitope specificities. The number of T-cell epitope specificities was manipulated by pulsing different humor of HLA-A2 restricted peptide（s） onto the T2 cells, which acted as stimulating cells to elicit allo-reaction by co-culturing with peripheral blood lymphocytes （PBLs） of HLA-A2 negative individual. Ten HLA-A2 restricted peptides （all were normal cell components ） were synthesized, and cell peptide extract was prepared by frozen and thawed. T2 cells loaded with different number of peptide（s） were co-cultured with PBLs of an HLA-A2 negative individual; the latter were stained with PKH67 in advance. Then the proliferation was monitored with flow cytometry, and the precursor frequency of the effector cells was ＇analyzed by the ModFit Software. After 6 d of culture, no proliferation was observed in the bulk culture of PBL alone, and obvious proliferation took place when PBLs of the HLA-A2 negative were co-cultured with T2 cells loaded with or without loading peptide（ s）. The precursor frequency of the alloreactive CTLs was 0.052 819 for co-culture with T2 cells loaded without peptide; however it was 0. 030 429 for T2 cells with EBV/LMP2A and 0. 030 528 for T2 cells loaded with a single autogeneic peptide, and increased up to 0. 144 942 for T2 cells loaded with 10 autogeneic peptides; the precursor frequency was 0. 203 649 when co-cultured with T2 cells loaded with miscellaneous peptides extracted from the cytoplasm of T2 cells. This study reveals that the precursor frequency of alloreactive CTLs is proportional to the number of T-cell epitope specificities, and independent of the density of the allogeneic HLA Class Ⅰ molecule. Our findings support the hypothesis that the alloreactive T cell populations comprise miscellaneous T cell clones; each is specific to corresponding pMHC. The novel constellation of peptides presented by allogeneic MHC molecules makes thousands of different epitopes, which account for the exceptional high precursor frequency of alloreactive T cells.