Objective To observe the effects of Astragalus polysaccharide ( APS) on tumor growth, cytokine and immune function impairment induced by cisplatin ( DDP) in mice bearing Lewis lung cancer.Methods A total of 90 mice were used in this study:10 for blank control group, and 80 mice with transplanted Lewis lung cancer were randomly divided into 8 groups:model control group (physiological saline), positive control group treated with DDP (6 mg/kg), low dose APS (50 mg/kg), moderate dose APS (100 mg/kg) and high dose APS (200 mg/kg) groups and three combinations of APS+DDP groups ( the same three APS levels with half dose of DDP, respectively) .0.3 mL of the drugs was intraper-itoneally injected to the mice, respectively, on the second day after moldeling.DDP was injected once a week and other drugs were injected once per day for consecutive 20 days.On the 21st day, blood samples were collected and serum levels of cytokine IL-2, IL-6, IL-12 and TNF-αwere determined by ELISA, and the tumor inhibition rate and immune organ in-dexes were assessed.Results The tumor inhibition rates of the positive control, low, moderate and high dose APS groups and three combinations of APS+DDP groups of mice bearing Lewis lung carcinoma were 49.30%, 17.21%, 39.68%, 17.21%, 51.02%, 57.21%and 65.11%, respectively.Compared with the model group, P<0.05 or P<0.01, and compared the three combination groups with the DDP group, P<0.05.Compared with the blank control group, the spleen index was significantly increased in the moderate and high dose APS groups and the three combinations of APS +DDP groups.There was a significant difference between the spleen indexes of the model control group, and the spleen indexes of high dose APS and the combination with high dose APS groups were significantly higher than that of the model control group (P<0.05).Compared with the DDP group, APS in various doses and combinations increased the thymus index and spleen index.Conclusions APS can improve the levels of cytokine IL -2, IL-6, IL-12 and TNF-αin mice bearing Lewis lung cancer, enhance the immune function impairment induced by DDP, has certain protective effect on the immune organs, and inhibit the growth of Lewis lung cancer in mice.When APS is used in combination with a half-dose of DDP, APS enhanced the inhibition of tumor growth.This mechanism may be related to the enhanced body immune function.Our results indicate that APS enhances the therapeutic effect of DDP and reduces its toxicity, therefore, may have potential application value in future treatment of solid tumors.

Objective To explore the establishment of a rabbit model of atrial fibrillation by wireless telemetering and stimulation technology.Method An implantable telemetering stimulator which was independently designed and devel-oped was hypodermically implanted in New Zealand rabbits.The implantable telemetering stimulator was made with the core development and design of MSP single-chip microcomputer of TI Corporation ( Texas Instruments) and RF wireless trans-ceiver chip CC2250 of TI Corporation.The design of the implantation system was optimized to cater to the exploratory ex-periment to establish atrial fibrillation model of New Zealand rabbits.The implanter was implanted into the abdominal sub-cutaneous tissue of the New Zealand rabbits, the collecting electrodes were placed in the oxter subcutaneous tissues of the left and the right upper extremities, and the two stimulating electrodes were sutured at the left auricle and the left atrium. The signals were collected and stimulated by the wireless transceiver.The I-lead ECG electrical signals were continuously monitored on the body surface by a Powerlab physiological recorder.High frequency ( >20 Hz) suprathreshold stimulus ( intensity 2 mA, pulse width 1 ms) was emitted by specialized stimulation software of a computer program by the interval ( stimulating for 2 s and pausing for 2 s) .In case of atrial fibrillation during intervals, the stimulation could be stopped by hand.In case of sinus rhythm, the stimulation could be continued.Results The implantable telemetering stimulator can work stably in vivo ( including collecting stimulated electrocardio signal and emitting stimulations) for 30 days.Atrial fibril-lation can be induced after stimulating in vivo of the New Zealand rabbits for 3 weeks, with a duration of >48 h.Conclu-sions Applying implantable telemetering stimulator can build a New Zealand istead of beagles model of atrial fibrillation which is more consistent with welfare optimization and substitution principle for laboratory animals.

Objective To establish an optimal animal model of pulmonary metastasis of human lung adenocarcino-ma, to serve further investigation of mechanism of lung adenocarcinoma metastasis.Methods Eleven nude mice aged 4-6 weeks were used in this study.Suspension of human lung adnocarcinoma A549 cells (0.1 mL, 107 cells/mL) was injec-ted into the tail vein in nude mice.From four weeks after inoculation, two nude mice were killed each time at 4, 5, 6 weeks after the tumor cell injection at random for examination.The remaining 3 mice were killed at the end of the experi-ment.At autopsy, the lung, brain, liver, kidney and other organs were removed, fixed in neutral buffered formalin and embedded in paraffin.Sections were cut and stained with hematoxylin-eosin, and examined by histopathology.The number of metastatic foci was counted.Results No mouse died after tumor cell inoculation.Serially euthanized mice revealed evi-dence of gradually increasing pulmonary metastases in the mice:No metastasis was found before 4 weeks after tumor cell in-oculation, the first histological metastases appeared at 5 weeks, gross metastatic foci were observed at 6 weeks, widely spread metastatic foci were observed at 7 weeks, and the remain 3 mice developed cachesia at 11, 13, and 14 weeks after tumor cell inoculation.Mediastinal lymph node metastases were found in the nude mice by 11 weeks after tumor cell inocu-lation.Conclusions We have successfully established a nude mouse model of pulmonary metastasis by injecting human lung adenocarcinoma A549 cells into the tail vein.

Objective To clone the coding sequence of Guangxi Bama mini-pig PGC-1αgene, and to analyze the expression of PGC-1αgene in various tissues of mini-pigs using RT-PCR and QRT-PCR techniques.Methods The PGC-1αgene coding sequence ( CDS) was amplified by PCR from the cDNA of longissimus muscle of Guangxi Bama mini-pig. The PCR products were inserted into pEASY-T5 vector, transfected E.coli, identified and sequenced.The PGC-1αgene expression in different tissues of the Bama mini-pigs was detected by RT-PCR and QRT-PCR assays.Results The PGC-1αgene CDS of Guangxi Bama mini-pig was cloned.It was 2391 bp in length.It had 99.9%homology with the reference sequence, and had two synonymous mutations that were C-A1105 and G-A1524.The expression level of PGC-1αgene was higher in the heart and kidney, followed by liver, subcutaneous fat and longissimus muscle, but the expression was not de-tected in pancreas of Guangxi Bama mini-pig.Conclusions We have successfully cloned the PGC-1αgene of Guangxi Bama mini-pig, and detected this gene expression in six tissues.The results of this study will provide a basis for studying the effect of PGC-1αon type 2 diabetes mellitus (T2DM) in Bama mini-pigs.

Objective To explore the effect of caspase-9 inhibitor on low fetal bovine serum ( FBS)-induced apop-tosis in cartilage endplate chondrocytes in SD rat vertebrae.Methods Disc cartilage endplates were obtained from 3-month old SD rats and subjected to sequential digestion to harvest chondrocytes for primary culture, and apoptosis was in-duced by 1%FBS for 48 hours.Three groups of chondrocytes were treated by 1% FBS, caspase-9 inhibitor ( Z-LEHD-FMK) and DMSO, respectively.After 48 hours, apoptosis was detected by DAPI staining and flow cytometry.The expres-sion of procaspase-9, active caspase-9 and active caspase-3 was monitored by Western blot.Results Compared with the 1%FBS group (40.8 ±0.84)%and DMSO group (40.2 ±1.56)%, the apoptosis rate of the caspase-9 inhibitor group (26.3 ±2.56)% was significantly lower (P<0.05).The expressions of active caspase-9 and active caspase-3 in the caspase-9 inhibitor group were significantly lower than those in the other two groups (P<0.05).Conclusions Caspase-9 inhibitor can inhibit low FBS-induced apoptosis in cartilage endplate chondrocytes of rat vertebrae, and might become a new drug for the treatment of disc degeneration.

Objective To observe the effects of angiotensin Ⅱ( Ang Ⅱ) blockade on renal function, renal blood flow and renal oxygen consumption in chronic renal failure ( CRF) rats induced by 5/6th kidney ablation /infarction (5/6A/I).Methods Sprague-Dawley rats were randomly divided into 3 groups:the normal group (group A, n =14), mod-el group (group B, n=14) and angiotensin II blockade (Cozaar with Monopril) treatment group (group C, n =14).The chronic renal failure ( CRF) rat models were induced by 5/6th kidney ablation/infarction.The tail artery systolic pressure (SBP), diastolic blood pressure (DBP) and tail vein serum creatinine (Scr), blood urea nitrogen (BUN), hemoglobin ( Hb) and creatinine clearance rate ( Ccr) were assessed before and after intervention.The course of treatment was sixty days.The renal blood flow ( RBF) , blood gas analysis of abdominal aortic and renal vein, left renal vein pressure ( RV-pO2 ) were detected and remnant renal oxygen consumption ( QO2/TNa ) was calculated, and the pathological changes of remnant kidney were observed after the 60 d intervention.Results (1) Compared with the group A, the levels of Scr, BUN and tail artery SBP, DBP were significantly increased ( P<0.01 for all) , and the levels of Ccr and Hb were signifi-cantly decreased ( P<0.01) in the groups B and C, demonstrating the successful modeling.(2) Compared with the group B, the levels of Scr, tail artery SBP, DBP and QO2/TNa were significantly decreased (P<0.01 for all), the levels of BUN were decreased (P<0.05), the levels of Hb, Ccr and RVpO2 were significantly increased (P<0.01 for all), the level of RBF was increased ( P<0.05) in the group C after intervention.(3) The histopathological examination of the remnant re-nal tissue showed that the pathological changes in the group C were apparently reduced, better than those of the Group B. Conclusions Angiotensin II blockade can increase RBF, reduce renal oxygen consumption, improve renal function, and reduce the renal pathological changes in CRF rats.The mechanism of renal protection may be related to the regulation of cellular energy metabolism and improvement of renal oxygen consumption.

Hepatitis C virus ( HCV) is a leading cause of chronic hepatitis, cirrhosis, and hepatocellular carcino-ma in humans.Due to the lack of suitable experimental animal models for HCV infection, the development of more effective treatment of HCV infection and vaccines has been delayed.Chimpanzee is the best experimental animal model for the re-search of hepatitis C virus ( HCV) infection.However, because of its limited in resource, expensive in breeding, and difference in clinical symptoms, thus developing new experimental animal models for HCV-related basic and applied re-search is imminent.In recent years, as a surrogate animal model, the development of rodent model and other models has been achieved a lot of progress.Using such as genetically modified experimental techniques, those surrogate animals were infected with HCV in vivo and were successfully applied to research in several areas.In this review, we will focus on the a-chieved progress in naturally infected animal model and transgenic surrogate experimental models, and their advantage and limitation in usage in study on the pathogenetic mechanism of infection, drug evaluation and development of vaccines, and will also discuss the future direction of development of experimental animal models for research of infection with HCV.

Liver diseases post great threats to human public health globally.Lacking of appropriate small animal models largely impeded the translational studies on human liver diseases, especially on viral hepatitis and related cirrhosis, hepatocellular carcinoma, etc.By human hepatocyte transplantation, the liver-humanized mice have significantly contribu-ted to the researches of human liver diseases.This review summarizes the currently widely used and representative human-ized mouse models, including uPA, FAH, TK-NOG, AFC8 mice and their applications in studies of human liver diseases.

Objective To obtain a stably inherited Sprague-Dawley rat model of congenital umbilical hernia by in-breeding, and to observe the structure of umbilical hernia and treat it surgically.Methods Congenital umbilical hernia rats were fostered by full-sib mating.The birth number and umbilical hernia quantity were recorded, and the umbilical hernia rate of rats was analyzed.Six female and 6 male rats with congenital umbilical hernia of 6-month aged F2 generation were selected randomly, among which 2 female and 2 male rats were examined anatomically, and the rest rats underwent surgical suture. Results The umbilical hernia rate was increased along with the increasing inbreeding coefficient, and the rats of F12 and F13 generations were all with congenital umbilical hernia.The umbilical hernia rate in female rats was significantly higher than that in male rats based on the total number of rats from F1 to F13 generation (c2 =11.1, P=0.001).Female and male rats had the same structure of umbilical hernia, and all rats recovered 3-4 weeks after surgery without recurrence.Conclusion After 13 consecutive generations of full-sib mating, a rat model of congenital umbilical hernia with stable genetic properties is successfully established.

Objective To establish a mouse model of orthotopic Lewis lung carcinoma using Matrigel, to evaluate the tumor growth and metastasis, and to provide a more stable mouse model of orthotopic lung cancer, which is more similar to human lung cancer.Methods Logarithmic phase of cultured Lewis lung cancer cells were suspended in Matrigel, vac-cinated into the left lung of inbred C57BL/6 mice.Five mice were killed on the 4th, 7th, 10th, 13th, and 16th days, re-spectively, and to observe the median survival, tumor formation rate, tumor growth, and metastasis.Pathological changes of the mouse lung, liver, kidney and spleen were examined.Results In 5 mice killed on the 7th postoperative day, small tumor nodules were observed on the lung in three mice and no tumor was visible by gross inspection in the other two mice, but small tumor nodules were observed under the microscope.For all the mice killed on the 10th postoperative day, tumors were visible to the naked eye on the lung of all the five mice.On the 13th day, orthotopic tumor was observed on the lung with bloody pleural effusion and pleural metastasis in all the five mice.On the 25th day, in addition to the pleural metasta-sis, one mouse had pericardial metastasis and renal metastasis.The survival periods of the 5 mice were 17 d, 20 d, 22 d, 22 d, and 25 d, respectively, with a median survival period of 21.2 d (17-25 d), and the tumor formation rate was 100%.Conclusions Mouse models of orthotopic Lewis lung carcinoma is successfully established using injection of tumor cells suspended in Matrigel.This model is more similar to the growth of human lung cancer, with good stability, high tumor formation rate and characteristics of distant metastasis, therefore, is worthy of further application.