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Two-dimensional electrophoresis performed on a microfluidic chip could reduce the consumption of sample and reagents, realizing high-throughput analysis in a very short time. During the isoelectric focusing ( IEF) separation, the buffer for the two different separation methods should be kept from being mixed. After the IEF, the protein was transferred from the IEF channel into the second dimension channels. Based on the pseudo valve structure, this paper reported a method to deposit a titanium dioxide membrane at the interface of two dimensional channels, which enhanced the performance of the pseudo valve. The IEF electrophoresis and SDS-polyacrylamide gel electrophoresis ( SDS-PAGE ) procedures were characterized respectively. The total separation took 10-15 min, and the protein's migration rate was linear with the migration time, and inversely proportional to the logarithm of protein molecular weight. Based on the above results, the differential two-dimensional electrophoresis was performed to test the deviation between different measurements.
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Objective To explore the basic ingredients of the tree shrew’ s( Tupaia belangeri) milk and compare with the dairy ingredients of other milks.Methods We select ten seed tree shrews after delivery ( 1 ~21 ) d with lactation mother tree shrews, and use artificial passive breastfeeding method let the young tree shrews suck breast milk,we took the milk from the young tree shrews in the stomach, directly using aseptic operation with a syringe immediately, once every two days, for consecutive three to five times, and a total of 18 mL milk was taken from each seed tree shrew.Then the milk was detected according to the national standard method for component testing.Results The total solid content of the tree shrew’ s milk was 43.63%, including 26.01%of fat, 10.41%of protein, 0.45% of lactose and 0.99%of ash content.Compared with cow's milk, the tree shrew’ s milk contained 3.36 times of total solid contents, 1.24 times of ash, 2.74 times of protein, 6.67 times of fat, and 0.09 times of lactose.Compare with baby formula milk, the tree shrew’ s milk contained 1.44 times of total solid contents, 0.20 times of ash, 0.58 times of protein, 1.53 times of fat, and 0.06 times of lactose.The trace mineral composition of the tree shrew’ s milk showed that the calcium, phosphorus, potassium, sodium, magnesium, and iron contents were 1.83 times, 2.73 times, 1.25 times, 1.93 times, 1.28 times, and 1.48 times higher than those in the cow's milk, and were 0.66 times, 0.85 times, 0.34 times, 0.26 times, 0.85 times, 0.24 times lower than those in baby formula milk.Conclusions The main nutrients of tree shrew’ s milk is of high fat, high protein and low sugar, and it can provide a basis for tree shrews artificial brood and breeding work.
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[ ABSTRACT] AIM:To investigate the effect of silencing cell division cycle 25a ( CDC25a) gene on the prolifera-tion of human hepatoma HepG2 cells.METHODS:CDC25a gene in human hepatoma HepG2 cells was silenced by RNA interference.Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells.Western blotting was applied to detect the expression of CDC25a at protein level.In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells.RESULTS:The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P<0.05).The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P<0.05).The cell proliferation in silence group was lower than that in negative control group and normal control group ( P<0.05) .The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase.CONCLUSION:Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effec-tively inhibits the CDC25a gene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25a gene may be a key target for the treatment of liver cancer.
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AIM:To explore the changes and significance of Kupffer cells in the process of tree shrew chroni -cally infected with hepatitis B virus (HBV).METHODS:The animals were divided into 3 groups.Group A consists of 6 tree shrews that were identified as persistently infected with HBV;group B consists of 3 tree shrews that were suspected as persistently infected with HBV;group C consists of 4 tree shrews that were not inoculated with HBV and were applied as normal controls.Liver biopsies were collected regularly from all animals , and the Kupffer cells were isolated , purified and primarily cultured.The techniques of flow cytometry , immunohistochemistry, lysosomal fluorescent probe staining and real-time RT-PCR were applied to determine the number and function of these Kupffer cells .RESULTS: The result showed that the count and proportion of CD 163+cells in group A were significantly higher than those in group B and group C ( P<0.05).Meanwhile, the fluorescence intensity levels of lysosomal , the number of lysozyme-positive cells and the mRNA ex-pression level of TNF-αin the Kupffer cells in group A were significantly lower than those in group B and group C ( P<0.05).CONCLUSION:Kupffer cells may play a regulatory role during host’s chronic HBV infection.
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Objective:To test the expression of Minichromosome maintenance complex component 7(MCM7) protein in hepato-cellular carcinoma(HCC) of different species including human, rat and tree shrew (tupaia) by cross-species oncogenomics approach, and to investigate the relationship between the expression of MCM7 and the development of hepatocellular carcinoma and its clinical significance. Methods:Western blot and Immunohistochemistry were applied to detect the expression levels of MCM7 protein in HCC tissues,corresponding HCC-adjacent liver tissues and normal liver tissues collected from different species including human, rat and tree shrew, respectively. The clinicopathologic factors were also analyzed with the results of Immunohistochemistry. Results:Western blot analysis showed that the expression of MCM7 protein in HCC tissues of human and rat were higher than that in corresponding HCC-ad-jacent liver tissues and normal liver tissues, respectively and significantly (P0.05).There was also no significant difference between HCC-adjacent liver tis-sues and normal liver tissues in three species (P>0.05). Immunohistochemical analysis showed that MCM7 protein was mainly ex-pressed in nucleus of HCC cells, and the positive rate of MCM7 protein in HCC tissues of human, rat and tree shrew were significantly higher than that in corresponding HCC-adjacent liver tissues and normal liver tissues, respectively (P0.05). Moreover, the protein level of MCM7 was intimately related to patient's HCC stage, extrahepatic metastases and postoperative recurrence (P<0.05). Conclusion:MCM7 protein might play a pivotal role in hepatocarcinogenesis. In addition, it was probably related to patient's HCC stage, extrahepatic metastases and postoperative recurrence. It seems very likely that MCM7 may be applied as a new molecular target in HCC prevention and treat-ment.
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Objective:To study the effect of Ginkgo biloba extract (EGb761) on metabolism of aflatoxin B_1(AFB_1) in Wistar rats. Methods:Seventy one Wistar rats were divided into three groups at random: group A (AFB_1 group), group B (AFB_1+EGb761 group), and group C (control group). The rats in groups A and B were given AFB_1(intraperitoneal injection, 100-200 μg/ kg body weight, 1-3 times/week). The rats in group B were fed the food containing EGb761 while the rats in groups A and C were given normal food. Blood samples were collected and liver biopsy was performed on the 14th, 28th and 42nd week. All the rats were sacrificed at the 64th week. The incidence of hepatoma was observed. The hepatic phase Ⅰ drug-metabolizing enzyme CYP450 and phase Ⅱ enzyme GST were detected by spectrometry. The serum AFB_1-lysine adduct was determined by high performance liquid chromatography (HPLC). The expression of 8-hydroxydeoxyguanosine(8-OHdG) was measured by immunohistochemistry. Results:The incidence of hepatocellular carcinoma (HCC) in group B was significantly lower than that in group A (26.92% vs 76.00%,P<0.001). No hepatocellular carcinoma developed in group C. EGb761 had no effects on the activities of CYP450 and GST in rat liver tissues. The level of AFB_1-lysine adduct reached the peak (4 356.01 pg/mg albumin) at the 14th week in group A. EGb761 significantly inhibited the formation of AFB_1-lysine adducts in serum by 13.07% at the 14th week (P＝0.033), and 73.63% at the 42nd week (P＝0.002). The expression of 8-OHdG protein in rat liver tissues in group B was significantly lower than that in group A at the 28th, 42nd, and 64th week (P<0.05). Conclusion:The main mechanism underlying the effect of EGb761 in blocking hepatogenesis induced by AFB_1 may not be fully related with its influence on the activity of liver phase Ⅰ and phase Ⅱ metabolizing enzymes. EGb761 inhibites the production of AFB_1-lysine addcuts, decreases the expression of 8-OHdG protein, and finally alleviates the DNA oxidative injury, which may be one of the mechanisms for the effects of EGb761 in inhibiting or delaying hepatogenesis induced by AFB_1.
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Objective To provide a better cell model of closely nature infectious state for further research of hepatitis B virus(HBV). Methods Primary tupaia hepatocytes were isolated by the two-step perfusion method. The hepatocytes were then infected with purified serum from patients with hepatitis B. DNA and RNA isolated from the hepatocytes were detected with Southern blot and Northern blot. HBsAg in supernatant was tested by immunohistochemical method. Results cccDNA, pgRNA and sgRNA could be detected by Southern blot and Northem blot, and strong signals could be seen from day 7 to day 14 post-in-fection. The S/CO value of HBsAg in supernatant decreased from day 1 to day 5 and then increased after 5 day. Conclusion Primary tupaia hepatocytes are competent for infection with HBV. HBV can stably repli-cate and express in HBV-infected tupaia hepatocytes.
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Objective Using a short-term in vivo laboratory model of murine liver cancer induced with diethylnitrosamine (DEN),we inspected the impact of 5% C.Chrysantha leaves and 5% concentrations on induction of liver cancer with DEN.Methods Laboratory Winstar rats,all being male and SPF grade,were administered with the liver cancer initiator DEN(200?g/kg,ip,once only),then with murine food containing 0.015% 2-AAF (2-Acetaminoflueren) for 2 weeks,following an excision of the augmented parts as a selective promoting program that speeded up the proliferation of precancerous foci from the initiated hepatocytes.On the beginning of this experiment,5% C.Chrysantha leaves and 5% concentration-contained food were given to the trail rats; in contrast,normal food to the control.Rats were killed 3 days after feeding of 2-AAF-contained food.Targeting part of liver were collected for ?-glutamyltranspeptidase (?-GT) staining,and numbers and areas of?-GT positive foci per cm2 of the liver area were calculated using a software designed by us.Results Numbers and areas of?-GT positive foci of the trail are significantly less than those of the control.Conclusion 5% C.Chrysantha leaves and 5% concentrations inhibit the DEN induction to liver cancer.
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Objective:To search the marker of micrometastatic hepatocellular carcinoma (HCC).Methods:Peripheral blood samples were obtained from 65 patients with hepatocellular carcinoma,21 non HCC malignant tumors,22 chronic hepatitis B or cirrhosis,and 21 normal healthy volunteers.To identify hepatocellular carcinoma cells in peripheral blood, liver specific alpha fetoprotein(AFP)mRNA was amplified from total RNA extracted from whole blood by nested reverse transcription polymerase chain reaction (Nested RT PCR).Results:AFP mRNA was not detected in the normal healthy volunteers and patients with non HCC malignant tumors.The presence of AFP mRNA in patients with HCC(44/65,67.7%)was higher than those with chronic hepatitis B or cirrhosis(2/22,9.1%, P
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The effect of carbon tetrachloride (CCl4) on aflatoxin B1 (AFB1)-induced enzyme altered hepatic foci has been examined in young male Fischer rats given AIN-76A diet. A single i.p. dose of AFB1 (0.2 mg/kg body wt) was given to rats 24 h after partial hepatectomy. Two weeks later, CCl4 (0.8 ml/kg body wt) was injected i.p. once a week for 9 weeks. Animals were sacrificed 24 h after the last dose of CCl4 and glutathione S-transferase placental form (GST-P) and gamma-glutamyl transpeptidase (GGT) positive hepatic foci were analyzed by immunohistochemical and histochemical methods, respectively. Ten weeks after AFB1 dosing, treatment with CCl4 increased the number of AFB1-induced enzyme altered foci several fold and produced a ten to twenty-fold increase in area and volume. GST-P was more sensitive than GGT in detecting AFB1-induced enzyme altered foci. Treatment with AFB1 or CCl4 produced mild hepatic fibrosis in zones 1 and 3 respectively, whereas both treatments produced severe fibrosis in zones 1 to 3 areas. Treatment with CCl4 after AFB1 dosing lowered hepatic GSH levels by 20% and increased lipid peroxidation by 40%. It appears that CCl4, by being an effective enhancer of AFB1-induced enzyme altered hepatic foci in the rat, may mimic cirrhosis observed in human hepatocellular carcinoma.
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Male , Rats , Aflatoxin B1/pharmacology , Animals , Carbon Tetrachloride/pharmacology , Drug Synergism , Fibrosis/chemically induced , Glutathione Transferase/metabolism , Immunohistochemistry , Lipid Peroxidation/drug effects , Liver Neoplasms, Experimental/chemically induced , gamma-Glutamyltransferase/metabolismABSTRACT
Using tree shrew as an animal model, our previous studies have demonstrated synergistic effects of aflatoxin B-1 (AFB(1)) and human hepatitis B virus (HHBV) in the induction of hepatocellular carcinoma (HCC). In the present study, we have examined expression of p53 gene in HCCs induced by AFB(1) with or without HHBV infection in tree shrews. Avidin-biotin-peroxidase complex immunohistochemical method with human p53-CM1 polyclonal antibody has been used to detect p53 expression in serial sections of paraffin-embedded liver and HCC tissues. Five out of 9 animals with HCCs (55.6%) induced by AFB(1) with HHBV infection and 2/3 animals with HCCs (66.7%) induced by AFB(1) alone expressed the p53 protein. Out of 18 HCCs examined, expression of p53 protein was observed in 9/10 moderately and poorly differentiated HCCs (0/8). None of the well differentiated HCCs (0/8) expressed p53 (0%). Similarly, no p53 expression was observed in either non-tumorous or hyperplastic liver tissues or nodules. These results suggest that p53 expression associated with p53 mutation is a late event occurring probably during tumor progression in AFB(1) and HHBV induced hepatocarcinogenesis in the tree shrew. This report is the first example of an experimental animal model where combination of human HBV and AFB(1)-induced HCCs demonstrate p53 expression.