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Purpose: This study aimed to evaluate the correlation between infrared thermal imaging-magnetic resonance imaging (MRI)-pathology of microwave ablation (MWA) of lesions in rabbit lung tumors. Materials and Methods: MR-guided MWA was performed in nine VX2 tumor-bearing rabbits. Infrared thermal imaging, postoperative MRI, and pathological presentation were obtained and analyzed. The differences between the infrared thermal imaging-MRI-pathology of MWA were compared. Results: The center of the ablated lesion exhibited a high signal on T1-Vibe, and an isointense envelope was observed; the center of the ablated lesion exhibited a low signal on fat-suppressed turbo spin-echo T2-weighted imaging (TSE-T2WI-FS) and bands of high signal surrounding it compared with before MWA. No statistically significant difference existed between the maximum diameter of the central low-signal area of the ablation zone on TSE-T2WI-FS after MWA, the high-signal area of the ablation zone on T1-Vibe after MWA, and the maximum diameter of the pathological coagulation necrosis area, as well as between the maximum diameter of the isointense signal area peripheral to the ablation zone on T1-Vibe after MWA, the high-signal area peripheral to the ablation zone on TSE-T2WI-FS, the maximum diameter at the 41°C isothermal zone on infrared thermal imaging, and the maximum diameter of the pathological thermal injury zone. Conclusions: MWA of malignant lung tumors had specific MRI characteristics that were comparable with postoperative pathology. Infrared thermal imaging combined with MRI can be used to evaluate the extent of thermal damage to lung VX2 tumors
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Aims: We aimed to investigate the feasibility, safety, and efficacy of radiofrequency ablation (RFA) combined with percutaneous vertebroplasty (PVP) for treating VX2 vertebral metastases with posterior margin destruction in a rabbit model. Materials and Methods: Sixty rabbit models of VX2 vertebral metastases with posterior margin destruction were constructed through computed tomography (CT)-guided percutaneous puncture and randomly divided into four groups of 15 rabbits each: Groups A, RFA+PVP; B, PVP; C, RFA; and D, control. Five rabbits in each group were sacrificed within 24 h of the procedure. Pathological examination and immunohistochemical staining revealed the presence of a biomembrane barrier at the tumor edge; furthermore, bone cement leakage into the spinal canal was observed. The survival time of the remaining rabbits per group was observed, and the differences were analyzed. Results: CT scans of Group A and C rabbits revealed a low-density band around the tumor ablation region. Bone cement leakage rate significantly differed between Groups A and B (20% vs. 100%; P < 0.05). The average postoperative survival times of Group A, B, C, and D rabbits were 16.72 ± 0.93, 7.26 ± 0.75, 7.80 ± 1.30, and 3.84 ± 1.24 days, respectively, showing a significant difference between Group A and the remaining groups (P < 0.05). Conclusions: The biomembrane barrier formed at the tumor edge after RFA can prevent bone cement leakage into the spinal canal, reducing spinal cord injury and prolonging the survival time
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Objective To explore the application value of modified closed biopsy technique in puncture biopsy of rabbit model of VX2 transplanted bone tumor. Methods VX2 tumor tissue was cut from rabbit with VX2 tumor and transplanted into the bilateral tibia of 30 rabbits through the tibial plateau to make the model of VX2 transplanted bone tumor. Seven days after modeling, the proximal tibia puncture biopsy was performed under the guidance of X-ray, and the biopsy specimen was examined pathologically. The left leg was biopsied with modified closed biopsy technique (experimental group), and the right leg was biopsied with hollow needle (control group). On the 14th day after modeling, all rabbits were executed after X-ray examination around the puncture hole, and the soft tissue around the puncture hole was taken for pathological examination. Results By the end of the experiment, a total of 3 rabbits died, and finally 27 rabbits were included in the study. Tumor cells were detected in all the intramedullary specimens obtained by puncture biopsy. On the 14th day after modeling, X-ray examination showed that, compared with control group, the incidence of periosteal reaction and extraosseous high density shadow around the puncture hole, and the tumor cell metastasis rate were lower [14.81%(4/27) vs. 40.74%(11/27); 29.63%(8/27) vs. 100.00%(27/27)], the differences were statistically significant (P<0.05). Conclusions Both the modified closed biopsy technique and puncture needle aspiration biopsy can provide sufficient biopsy tissue for diagnosis of VX2 transplanted bone tumor in rabbits. Meanwhile, the improved closed biopsy technique can prevent local metastasis of tumor cells along the puncture channel to some extent.
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BACKGROUND: Many methods have been developed to establish a rabbit VX2 tumor model, but the reliability of each method has not been explored. In order to develop a reliable method, we made some improvements based on the existing methods. OBJECTIVE: To investigate the reliability of rabbit VX2 tumor tissue block implantation and cell suspension via modified and traditional implantation to make the rabbit tibia VX2 tumor model. METHODS: Forty healthy adult New Zealand white rabbits were randomly divided into two groups. Group A was treated with tissue block implantation for tibia VX2 tumor modeling, and group B was treated with cell suspension for tibia VX2 tumor modeling. Modified and traditional implantation was performed on the left and right tibia of the experimental animals, respectively. One hour after successful modeling, ultrasound examination of the puncture site was performed to determine whether there is hematoma. All experimental animals were sacrificed at 3 weeks. X-ray examination of the bilateral tibia was performed to confirm the tumor growth range. Tumor tissue and soft tissue around the puncture site were taken for general and pathological observation to compare the size of the tumor and identify whether there is tumor cell metastasis. RESULTS AND CONCLUSION: One rabbit died in the tissue block group, and all the experimental animals in the cell suspension group survived. X-ray examination indicated the tumors in the tissue block group invaded the cortex, but the tumors in the cell suspension group did not invade the cortex. Gross observation revealed that the tumor volume of the tissue block group was greater than that of the cell suspension group. In the tissue block group, there were one and seven cases of hematoma around the puncture site at 1 hour after modified and traditional implantation, respectively. In the cell suspension group, there were two and nine cases of hematoma around the puncture site at 1 hour after modified and traditional implantation, respectively. Pathological examination showed that local tumor invasion was found in 1 and 8 cases in the tissue block group as well as in 2 and 11 cases in the cell suspension group at 3 months after modified and traditional implantation, respectively. Our findings indicate that the tissue block implantation method is easier and more convenient than the cell suspension method for making rabbit VX2 bone tumors, and the tumor invasion rate of the tissue block implantation method is lower than that of the cell suspension method. Improved tissue block implantation can effectively reduce the tumor invasion rate during modeling.
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BACKGROUND: There are many methods to establish VX2 subcutaneous tumor model, and the existing modeling methods have their own advantages and disadvantages. To meet the needs of tumor experiments on animals, the method of establishing an animal tumor model with high-quality and high-efficiency is necessary. OBJECTIVE: To explore more simple and efficient way of modeling, provide rabbit VX2 subcutaneous tumor experiment with large quantities of high-quality animal models by comparing different methods to establish rabbit VX2 subcutaneous tumor model. METHODS: Sixty-six male New Zealand white rabbits were enrolled. Two of the 66 rabbits were used to prepare VX2 tumor-bearing rabbits, and tumor tissues were taken from the tumor-bearing rabbits to prepare tumor tissue blocks and tumor tissue suspensions. There were two groups in the experiment. In tumor tissue suspension group (n=20), the rabbits were injected with 0.15 mL of tissue suspension on the medial side of bilateral hind limbs after anesthesia; in tumor tissue block group (n=20), tumor tissue blocks were implanted subcutaneously on the medial side of bilateral hind limbs after anesthesia. Two tumor-bearing rabbits from each group were subjected to the corresponding vaccination methods, each passed for five generations. Tumor inoculation time in the two groups was record and compared. The tumor size and growth were observed by ultrasound with 2-D and CDFI mode. Tumor-take rate and serial passage of tumor tissues were observed and compared between the two groups. The experimental protocol was approved by the Animal Experiment Ethics Committee of the Army Medical University of PLA (approval No. AMUWE2020016) RESULTS AND CONCLUSION: The tumor inoculation time in the tissue suspension group [(75.70±11.16) s] was significant shortened compared with that in the tissue block group [(100.80±9.21) s; P=0.00]. The tumor-take rate was significantly higher in the tissue suspension group than the tissue block group (95% vs. 60%; P < 0.05). The tumor size was significantly larger in the tissue suspension group than the tissue block group (P < 0.05). The rate of tumor tissue series passage was significantly higher in the tissue suspension group than the tissue block group (95% vs. 65%; P < 0.05). Therefore, tissue suspension method for making the model of rabbit VX2 subcutaneous tumor is simpler and more efficient compared with the tissue block method.
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Purpose: The purpose of this study is to evaluate the feasibility of percutaneous transauricular artery access for hepatic artery catheterization using a peripherally inserted central catheter (PICC) device and hepatic artery catheterization through auricular approach. Methods: Ten New Zealand White rabbits were used to establish a VX2 liver tumor model. Hepatic artery angiography and embolization were performed 3 weeks after inoculation. The rabbits were restrained in supine position under anesthesia. Intra-arterial access was accomplished with percutaneous Seldinger technique through the auricular artery using a PICC device. The hepatic artery catheterization was performed with a microcatheter and guide wire. The rate of technical success and procedure time was investigated. Results: Two rabbits failed initial percutaneous transauricular arterial access, with success in a contralateral attempt. Thus, percutaneous transauricular arterial access was achieved in 10 of 12 auricular arteries, with a technical success rate of 83.3%. The time needed to obtain intra-auricular access was 7.2 ± 3.1 min. Hepatic artery catheterization, angiography, and embolization were accomplished through the auricular approach in all 10 rabbits. Conclusion: Arterial access in rabbits can be achieved through the auricular artery. Hepatic artery catheterization, angiography, and embolization can be performed through auricular arterial access
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Objective: To investigate the efficacy of antiangiogenesis, mechanism and timing of transcatheter arterial chemoembolization (TACE) combined with sorafenib in treatment of liver cancer in new Zealand rabbits with VX2 liver cancer model. Methods: Thirty New Zealand rabbits with VX2 liver cancer were randomly divided into normal saline control group, single TACE group, single sorafenib group, pre-TACE + sorafenib group and post-TACE + sorafenib group (n=6 in each). Serum VEGF was measured by ELISA 7 days before TACE, 1 day before TACE, 3 days after TACE, 7 days after TACE, and 14 days after TACE. All the rabbits were sacrificed 14 days after operation for MVD immunohistochemical staining, and the tumor growth rate of each group was compared. Results: Compared with that in normal saline control group, serum VEGF in TACE + sorafenib group, TACE + sorafenib group and TACE + sorafenib group increased significantly (P<0.05), but the peak value of VEGF in TACE + sorafenib group was lower than that in TACE group and TACE + sorafenib group(P<0.05). Fourteen days after TACE, the VEGF level in the group + sorafenib was the lowest and that in the group of one drug alone was the highest (P<0.05). In 14 days after TACE + sorafenib group, MVD value was higher than that in saline control group and sorafenib group, but significantly lower than that of single TACE group(P<0.05). The 14 days after TACE + sorafenib group had the smallest tumor growth(P<0.05). Conclusion: TACE combined with sorafenib can significantly inhibit the growth of VX2 liver cancer in rabbits. The effect of TACE combined with sorafenib is better than that of TACE alone or sorafenib alone. However, after TACE the level of VEGF is increased and the level of serum VEGF is decreased by combining sorafenib, which decreases the microvessel density. Moreover, the effect of TACE combined with sorafenib on anti-tumor and anti-angiogenesis is better than that after TACE.
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The purpose of the present work is to establish an ultra-minimal invasive percutaneous puncture inoculation method for a VX2 orthotopic lung cancer rabbit model with fewer technical difficulties, lower mortality of rabbits, a higher success rate and a shorter operation time, to evaluate the growth, metastasis and apoptosis of tumor by CT scans, necropsy, histological examination, flow cytometry and immunohistochemistry. The average inoculation time was 10–15 min per rabbit. The tumor-bearing rate was 100%. More than 90% of the tumor-bearing rabbits showed local solitary tumor with 2–10 mm diameters after two weeks post-inoculation, and the rate of chest seeding was only 8.3% (2/24). The tumors diameters increased to 4–16 mm, and irregularly short thorns were observed 3 weeks after inoculation. Five weeks post-inoculation, the liquefaction necrosis and a cavity developed, and the size of tumor grew further. Before natural death, the CT images showed that the tumors spread to the chest. The flow cytometry and immunohistochemistry indicated that there was less apoptosis in VX2 orthotopic lung cancer rabbit model compared to chemotherapy drug treatment group. Minimal invasive percutaneous puncture inoculation is an easy, fast and accurate method to establish the VX2 orthotopic lung cancer rabbit model, an ideal in situ tumor model similar to human malignant tumor growth.
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Humans , Rabbits , Apoptosis , Drug Therapy , Flow Cytometry , Immunohistochemistry , Lung Neoplasms , Lung , Methods , Mortality , Necrosis , Neoplasm Metastasis , Punctures , Thorax , Tomography, X-Ray ComputedABSTRACT
Objective To investigate the sequential biological effects and outcomes of microbubble-enhanced ultrasound (MEUS) combined with prothrombin on microwave ablation (MWA) in rabbit VX2 liver tumors using examination of transmission electron microscopy ,histopathology and contrast-enhanced ultrasound(CEUS) . Methods Eighty New Zealand rabbits with VX2 liver tumors were randomly divided into 4 groups ( 20 per group ) , including physiological saline group , prothrombin group , cavitation of microbubbles group ( cavitation group ) and cavitation of microbubbles combined prothrombin group (combined group) . After treatment ,the targeted liver tumors in all groups were ablated with MWA . On the 0 ,3 ,7 and 14 d ,the volumes of coagulated areas of 5 rabbits of each group randomly were measured using CEUS . Tissues in ablated areas ,transition areas and surrounding areas were examined under light microscopy with histopathology and transmission electron microscopy to observe the differences among 4 groups . Tumor metastasis was graded using visual method . Results On the 0 ,3 ,7 and 14 d ,the coagulated volumes in combined group were larger than those in remaining 3 groups ( all P ＜ 0 .001) . Under light microscopy with HE stain ,in transition area ,the fibra band in combined group was wider than those in remaining 3 groups on the 7 and 14 d ( all P ＜ 0 .05 ) . The observations under transmission electron microscopy showed that the cellular ultrastructure disorder in ablated area on the 0 d and mitochondrial injury in transition area on the 7 d were more severe in combined group than those in remaining 3 groups . Compared with the remaining 3 groups ,the degree of tumor metastasis in combined group was less ,and the time of ocurrence was later . Conclusions MEUS combined with prothrombin can significantly expand ablation volume ,enhance the necrosis of ablated tissues ,and inhibit tumor metastasis on rabbit VX 2 liver tumors . The fibra bands in the transition areas can promote the organization and repair the surrounding tissue in the ablation areas .
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Objective By using CT-guided percutaneous inoculation with "external pre-loaded and traced one-step implantation technique" to establish VX2 liver and kidney tumor model in experimental rabbits, and to evaluate the effectiveness and convenience of this technique. Methods By using a disposal 16G thoracic puncture needle (length of 8. 5 cm) and a self-made 18 G puncture probe, inoculation of tumor cells was performed in experimental rabbits. Retrograde filling of gelatin sponge strip, which was infiltrated with 0. 3 mL contrast medium, into the thoracic puncture needle lumen was performed, which was followed by retrograde loading of 1X1X3 mm3 VX2 tissue block, and the pre-assembly in vitro was completed. Under CT guidance, percutaneous puncturing of the target organ of experimental rabbit with pre - assembly probe was conducted, then, the end of the needle was inserted into the probe to push out the tumor tissue and gelatin sponge when it was verified that the needle tip reached the desired target point. After 30 seconds, the needle and probe were pulled out slowly and integrally, and the puncture point was manually pressed for 60 seconds. CT scan was performed to check the location of high-density gelatin sponge. The tumor inoculation time was recorded. Contrast - enhanced CT scan was employed at 2, 3 and 4 weeks after inoculation to validate the modeling results. Results Immediate postoperative CT scan showed that the inoculation site was manifested as nodular high density shadow in the liver or kidney parenchyma. Liver tumor modeling was used in 10 rabbits, and tumor formation was obtained in all 10 rabbits (100％, 10/10), and the mean time used for inoculation was 4. 3 minutes. Kidney tumor modeling was adopted in 10 rabbits, and tumor formation was obtained in 9 rabbits (90％, 9/10), and the mean time used for inoculation was 4. 9 minutes. The inoculated tumor was characterized by a single lesion in all experimental rabbits, the location of the tumor was basically the same as that of the high density gelatin sponge. Check-up contrast-enhanced CT scan showed that the liver implanted tumor had peripheral enhancement, which presented as ring - shaped enhancement on DSA. The kidney implanted tumor was manifested as renal parenchyma staining defect on both contrast - enhanced CT scan and DSA. After 3-4 weeks of inoculation, the implanted tumors grew rapidly. Conclusion For the establishment of rabbit VX2 liver and kidney tumor models, CT - guided percutaneous inoculation with "external pre-loaded and traced one-step implantation technique" is very effective. This technique has several advantages, such as convenient and time-saving, postoperative immediate confirmation of the inoculation site, higher tumor formation rate, solitary tumor formation, etc. (J Intervent Radiol, 2018, 27:252-256)
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Objective To study the pharmacokinetics of raltitrexed using different ways of drug delivery, including femoral venous infusion, hepatic artery perfusion, hepatic artery injection of lipiodol suspension, hepatic artery perfusion followed by embolization with Gelfoam. Methods According to the administration way of raltitrexed, a total of 40 New Zealand rabbit models with VX2 liver tumor were randomly divided into group A (femoral venous perfusion), group B (hepatic arterial perfusion), group C (hepatic artery injection of lipiodol suspension), and group D(hepatic artery perfusion followed by embolization with Gelfoam). Drug concentration in plasma were determined by using LC-MS/MS method and the pharmacokinetic parameters were calculated. Results After administration of raltitrexed, the Tmax was 5 minutes in all 4 groups. In group A, B, C and D, the values were (5.88±1.39), (7.31±2.60), (9.86±5.10) and (7.19±2.27) respectively, with group C having the longest t1/2 value, which was significantly different with that of group A (P＜0.05); the (ng·ml-1·h-1) values were (2 056.40± 139.17), (1 389.21±180.28), (911.84±105.62) and (1 133.41±181.42)respectively, with the value of group A being obviously higher than that of group B, C and D (P＜0.05) and the value of group C being the lowest; the AUC0-t(ng· ml-1·h-1) values were (5 482.72±1 007.07), (4 156.99±1 475.77), (2 785.13±1 107.36) and (3 903.64±947.25) respectively, with the value of group A being remarkably higher than that of group B, C and D (P＜0.05) and the value of group C being the lowest. Conclusion Compared with the femoral vein infusion way, the ways of hepatic artery infusion, hepatic artery lipiodol suspension injection and hepatic artery perfusion followed by embolization with Gelfoam may promote more raltitrexed to deposit in the tumor area, thus, the curative effect is enhanced, the drug concentration in plasma is lowered and the side effects are alleviated.
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Objective To relieve the influences of the respiratory motion on the liver contrast-enhance ultrasound (CEUS) image sequences,to enhance the quantitative analysis accuracy for liver CEUS and to put forward a correction strategy for the respiratory motion in liver CEUS sequences.Methods A principal component analysis (PCA) model of the respiratory motion in liver CEUS sequences was established with 18 cases of rabbit liver VX2 tumors,and a respiratory motion curve was generated based on the principal component with large data proportion,then the images with similar phases to the reference image were analyzed.Resnlts Correction made the mean structural similarity and mean correlation coefficient enhanced significantly to 0.57±0.11 and 0.78±0.11 respectively (P＜0.001),while the average of deviation valve (DV) was decreased to 29.9±7.02 which only was one-third of the original value.Threshold setting could further improve the quality of the selected image sequence.Conchusion The proposed respiratory motion method proves its effectiveness for rabbit liver CEUS image sequences,and thus contributes to enhancing the differential diagnosis rate of benign and malignant liver tumors.
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Objective To relieve the influences of the respiratory motion on the liver contrast-enhance ultrasound (CEUS) image sequences,to enhance the quantitative analysis accuracy for liver CEUS and to put forward a correction strategy for the respiratory motion in liver CEUS sequences.Methods A principal component analysis (PCA) model of the respiratory motion in liver CEUS sequences was established with 18 cases of rabbit liver VX2 tumors,and a respiratory motion curve was generated based on the principal component with large data proportion,then the images with similar phases to the reference image were analyzed.Resnlts Correction made the mean structural similarity and mean correlation coefficient enhanced significantly to 0.57±0.11 and 0.78±0.11 respectively (P＜0.001),while the average of deviation valve (DV) was decreased to 29.9±7.02 which only was one-third of the original value.Threshold setting could further improve the quality of the selected image sequence.Conchusion The proposed respiratory motion method proves its effectiveness for rabbit liver CEUS image sequences,and thus contributes to enhancing the differential diagnosis rate of benign and malignant liver tumors.
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Objective:To study the effects of the treatment for rabbit VX-2 tongue cancer with paclitaxel or paclitaxel liposome infusion through rabbit lingual artery or ear vein infusion.Methods:24 rabbits with VX-2 tongue cancer were divided into 6 groups(n =40) randomly.The rabits in 3 groups were respectively treated by intra-arterial infusion with paclitaxel,paclitaxel liposome and 5％ glucose,and those in other 3 groups by ear vein infusion with the same materials.After 7 days of treatment,the lesion volumes were measured for response evaluation,cells apotosis in the cancer tissure was detected by llowcytometry,P53 protein expression was examined by immunohistochemical staining,respectively.The data was analyzed by SPSS 20.0 software package.Results:The response rate and apotosis of the tumor cells in intra-arterial infusion with paclitaxel liposome group were higher than those in the other groups(P ＜ 0.05),P53 protein expression was lower than that of the other groups (P ＜ 0.05).Conclusion:Intra-arterial infusion through tongue artery with paclitaxel liposome is more effective than the other methods in the treatment of rabbit VX-2 tongue cancer.
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Objective:To evaluate the feasibility and therapeutic efficacy of transhepatic arterial embolization with superparamagnetic iron oxide (SPIO) and lipiodol (LIP) for the treatment of VX2 tumor in rabbits.Methods:Twenty-four rabbits with hepatic VX2 tumors by surgical implantation were randomly divided into 4 groups and treated with transhepatic arterial embolization of 4 different agents as follows (n=6 each):doxorubicin (DOX) group,DOX-LIP group,SPIO-DOX group,and SPIO-DOX-LIP group.Liver function (AST and ALT) was measured at 0,1,3,5 and 7 d after transhepatic arterial embolization.The serum DOX level was measured at 0,5,15,30,60,and 120 minutes after transhepatic arterial embolization.MRI was performed at 7 d after the treatment to assess the distribution of SPIO in the SPIO-DOX group and SPIO-DOX-LIP group,while CT was performed to assess the distribution of LIP in the DOX-LIP group and SPIO-DOX-LIP group.All the rabbits were sacrificed and their livers were removed at 7 d after treatment for the detection of tissue DOX level.The histopathologic examinations were performed including HE staining,Prussian blue staining and TUNEL assay,and then the tumor necrosis percentage and apoptosis index were calculated.Results:Compared to the DOX group,the levels of AST and ALT in other 3 groups were significantly elevated at 1 and 3 d after embolization (P＜0.05).The levels of ALT and AST in the DOX group,DOX-LIP group or SPIO-DOX-LIP group returned to the baseline at day 7,there were no significant differences (P＞0.05).The SPIO-DOX-LIP group exhibited the lowest serum DOX level at all time points up to 120 minutes after embolization (P＜0.05).However,the tissue DOX level in the SPIO-DOX-LIP group was the highest among all groups at day 7 (P＜0.05).The SPIO-DOX group and SPIO-DOX-LIP group showed significantly lower MRI signal intensity of tumors in T2 weighted imaging (T2WI) at day 7.Meanwhile DOX-LIP group and SPIO-DOX-LIP group showed that high-density lipiodol was deposited in the tumors in CT images.Histopathologic findings showed an almost complete central necrosis coagulation of tumors in the SPIO-DOX-LIP group,and the tumor necrosis percentage and tumor apoptosis index were significantly increased in the SPIO-DOX-LIP group compared to those in other 3 groups (P＜0.05).Conclusion:This novel drug-delivery system of SPIO nano-drug carrier together with LIP is safe and feasible when it is used for transhepatic arterial embolization for liver tumor.It provides an excellent MR and CT visualization and improves the therapeutic efficacy for the treatment of rabbit VX2 liver tumor.
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Objective To explore the expression of vascular endothelial growth factor (VEGF) and apoptosis of the tumor cells in the different regions of rabbit liver VX2 tumor after radiofrequency ablation (RFA).Methods Forty-eight experimental rabbits were implanted with VX2 tumor.After successfully established the model,the rabbits were randomly divided into control group (n=6) and RFA group (n=42).In the RFA group,7 rabbits at each time point were killed at immediately,1 day,2 days,1 week,2 weeks,3 weeks after RFA,and the tumor specimens were retained and performed with HE staining,VEGF,Annexin V-FITC/PI labeling,flow cytometry analysis.The changes of VEGF and apoptosis of the cells in different periods and different zones after RFA were observed.Results After the operation,the difference of the VEGF value of the needle zone,coagulation necrotic zone and junction zone had statistically significant (all P＜0.05).The difference of the VEGF value in each zone between immediately and the other time points after operation by pairwise comparisons were significantly different (all P＜0.05).The VEGF value of the needle zone and coagulation necrotic zone reached the peak after operation immediately,which declined from 1 day to 3 weeks after operative.And VEGF of the junction zone increased from immediately to 1 week after operation,and declined 2 weeks after operation.There were significant differences in the apoptosis rate of the three zones after RFA compared with control group (all P＜0.05).The apoptosis rate in all zones were at the peak on the 1 day after operation,and then showed a downward trend.Conclusion The reduction of VEGF and apoptosis of tumor cells in the needle zone and coagulation necrotic zone are significant,but tumor remnant remains visible in the junction zone.In the third week after RFA,the proliferation of the remaining tumor cells can be recurrent to preoperative levels,which suggests that the further treatment should be performed at this period.
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Objective:To study the effects of antimicrobial therapy on the maturation and function of dendritic cells(DCs) in the infected microenvironment of rabbit buccal VX-2 squamous cell carcinoma.Methods:The inflammatory models were obtained by mechanical trauma and high sugar diet on the basis of rabbit buccal VX-2 squamous cell carcinoma models which were established by particle implantation of the tumor tissue.The model rabbits were divided into 3 groups (n =6).In group A the rabbits with buccal VX-2 squamous cell carcinoma and local inflammation were given antibiotics by gavage and intramuscular injection for 3 consecutive days;the rabbits in group B with buccal VX-2 squamous cell carcinoma and local inflammation were given normal saline by gavage and intramuscular injection;the rabbits in group C with tumor and without inflammation were given normal saline by gavage and intramuscular injection.The tumor specimens were collected 3 days after treatment,and made into tissue homogenate,supernatant was collected after centrifugation.Normal rabbit peripheral blood mononuclear cells were separated and co-cultured with the supernatant obtained from the 3 groups respectively.Expressions of DCs surface markers HLA-DR,CD83 and CD86 were detected by flow cytometry.the function of DCs was tested by mixed lymphocyte reaction.Results:The positive rate of HLA-DR,CD83,CD86 and stimulate index were group C ＞ group A ＞ group B (P ＜ 0.05).Conclusion:Antimicrobial therapy can promote the maturation and function of DCs in the infected microenvironment of rabbit buccal VX-2 squamous cell carcinoma.
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Objective To establish rabbit model bearing VX2 liver tumor using improved technique,and to analyze the relevant impact factors of hepatic artery and portal vein catheterization.Methods Transplanted liver tumors of 60 healthy New Zealand white rabbits were established through open abdominal puncture and hepatic artery and portal vein catheterization.The rabbits were divided into A group (survival) and B group (death) according to whether a short-term (within 7 days after surgery) death occurred or not.The univariate analysis of the factors which could lead to the death of rabbits were analyzed.The Logistic regression models were established with parameters which were significantly different between the 2 groups,and independent risk factors which could lead to the failure of the experiment were analyzed.Results VX2 tumors were successfully implanted in the liver to all 60 rabbits.Nine (9/60,15.00 ％) rabbits died within 7 days,while 51 (51/60,85.00％) rabbits survived,weight ＜ 2.5 kg,additional intraoperative anesthesia,operation time ≥60 min,length of incision ≥5 cm and blood loss of operation ≥25 ml were impact factors (all P＜0.05).Weight ＜ 2.5 kg,additional intraoperative anesthesia and the blood loss of operation ≥25 ml were independent risk factors for death (P＜0.01).Conclusion Relative high success rate of building rabbit models bearing VX2 liver tumor may achieved using hepatic artery and portal vein catheterization.Larger weight of rabbits,training of surgical skills,less intraoperative blood loss are helpful to avoid intraoperative additional anesthesia,thus reducing mortality of rabbits.
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Objective Few reports are seen on the methods of establishing the rabbit model of pancreatic cancer .This study was to compare the effect of Panc-1 cell suspension orthotopic implantation with that of VX-2 tissue orthotopic implantation in construc-ting the rabbit model of pancreatic cancer . Methods Using the random number table method , we divided 30 healthy rabbits into a tissue suspension group ( n=15) and a cell suspension group ( n=15) , VX-2 tissue suspension employed for in-situ implanting in the former group and panc-1 cell suspension utilized in the latter .Then we evaluated the two modeling methods by B-ultrasonography , 3.0T MRI, and CT. Results In the third week after modeling , transpla-ntive metastasis of lots of tumor tissues was observed in the duode-num, colon, appendix, and peritoneal wall in 5 rabbits of the tissue suspension group , but only in the greater omentum of 3 rabbits in the cell suspension group , with high signals of MR T 2 in the posterior gastric body .One case of duodenal metastasis was seen in the cell suspension group , with slightly high signals of MR LAVA in the posterior gastric body .The model of pancreatic cancer was successfully established in all the 15 rabbits of the tissue suspension group , but only in 3 of the cell suspension group .The success rate of tumor im-planting at 3 and 4 weeks was significantly higher in the former ( 46.66%and 100%) than in the latter group ( 6.67%and 20.00%) (P<0.05). Conclusion VX-2 tissue orthotopic implantation is a more feasible and convenient method than Panc -1 cell suspension orthotopic implantation for establishing the rabbit model of pancreatic cancer .
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Objective To evaluate the influence of dosage,operation method,adverse reaction of endoscopic photodynamic therapy (EPDT) on its therapeutic efficacy in rabbit models of in-situ rectal cancer,so as to provide preclinical basis of photodynamic therapy for rectal cancer.Methods 20 rabbits with in-situ VX2 rectal cancer were randomly divided into control group,PDT low dose group,intermediate dose group,and high dose group.At 24 h before PDT,photosensitizer (hermimether) was intravenously injected into rabbits.630 nm semiconductor laser was used as light source.The growth of the tumor was observed by conventional endoscopy and endoscopic ultrasonography,and the survival time,general conditions and adverse reactions were recorded.The histopathological changes were observed by hematoxylin-eosin staining.Results At 7 d after PDT,the total response rates of low dose,intermediate dose and high dose group respectively were 40％ (slight),80％ (60％ remarkable and 20％ slight),100％ (20％ remarkable and 80％ slight).The average survival times of the three groups were 14 d,10 d and 5 d,respectively.The main adverse reactions were inflammation,intestinal obstruction,intestinal peristalsis loss and death.Conclusions The dosage of PDT is an important factor to influence the curative effect.The appropriate dose of PDT will have a better effect on the treatment of rectal cancer.A thorough study of these problems is helpful to the clinical application of PDT in the treatment of rectal cancer.