Establishment of an orthotopic transplantation tumor model of hepatocellular carcinoma in mice

AIM:To improve the outcome of orthotopic transplantation in a mouse model,we used an absorbable gelatin sponge(AGS) in nude mice to establish an orthotopic implantation tumor model.METHODS:MHCC-97L hepatocellular carcinoma(HCC)cells stably expressing the luciferase gene were injected into the subcutaneous region of nude mice.One week later,the ectopic tumors were harvested and transplanted into the left liver lobe of nude mice.The AGS was used to establish the nude mouse orthotopic implantation tumor model.The tumor suppressor gene,paired box gene 5(PAX5),which is a tumor suppressor in HCC,was transfected into HCC cells to validate the model.Tumor growth was measured by bioluminescence imaging technology.Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) and histopathology were used to confirm the tumorigenicity of the implanted tumor from the MHCC-97L cell line.RESULTS:We successfully developed an orthotopic transplantation tumor model in nude mice with the use of an AGS.The success rate of tumor transplantation was improved from 60% in the control group to 100% in the experimental group using AGS.The detection of fluorescent signals showed that tumors grew in all live nude mice.The mice were divided into 3 groups:AGS-,AGS+/PAX5-and AGS+/PAX5 +.Tumor size was significantly smaller in PAX5 transfected nude mice compared to control mice(P < 0.0001).These fluorescent signal results were consistent with observations made during surgery.Pathologic examination further confirmed that the tissues from the ectopic tumor were HCC.Results from RT-PCR proved that the HCC originated from MHCC-97L cells.CONCLUSION:Using an AGS is a convenient and efficient way of establishing an indirect orthotopic liver transplantation tumor model with a high success rate.

Relation between eardrum flap area and healing outcome of traumatic eardrum perforation

Objective： To retrospectively study the clinical effects of eardrum flap area on the healing outcome following traumatic perforation.Methods： Totally 291 traumatic eardrum perforations with in-/everted edges were included in this study. They were randomly divided into three groups and received conservative treatment, epidermal growth factor （EGF） via Gelfoam patching, or edge-approximation plus Gelfoam patching respectively. Patients in each group were further divided into two subgroups according to the eardrum flap area ≤ 1/2 or 〉1/2 of the perforation size. The healing rate and mean closure time after tympanic membrane perforation were evaluated at three months.Results： Of the total 291 participants, 281 were included in the final statistical analysis. The area of curled edge did not affect the healing outcome significantly in any groups （P〉0.05）. The healing rate varied slightly： 90.7% vs 92.3% in spontaneous healing group, 98.2% vs 97.4% in EGF via Gelfoam patching group, and 96.5% vs 100% in edge-approximation plus Gelfoam patching group. In addition, in all groups the area of curled edge did not affect the mean closure time significantly （P〉0.05）. The closure time was （32.3±2.4） d vs （30.6±3.1） d in sponaneous healing group, （13.4±2.5） d vs （13.1± 1.9） d in EGF via Gelfoam patching group, and （11.9±3.1） d vs （12.2±2.1） d in edge-approximation plus Gelfoam patching group.Conclusion： The eardrum flap area of traumatic eardrum perforation does not significantly affect the clinical outcomes.