Dissent and Disputes ; Humans ; Occupational Diseases ; diagnosis

Objective: To explore the effect and mechanism of DMDAI-L in inducing the HL-60 cells apoptosis. Methods:Caspase-3 activity in HL-60 cells was measured with the enzymatic visible substrate DEVD-pNA. The fluorescence changes of mito-chondrial membrane potential (△Ψm) in HL-60 cells were investigated with the fluorescent probe JC-1. Results:The caspase-3 activ-ity was significantly increased in HL-60 cells after the DMDAI-L treatment at the concentration of 1. 25, 2. 5, 5, 10 and 20μg·ml-1 for 24h(P<0. 05). DMDAI-L could significantly reduce the mitochondrial membrane potential in HL-60 cells. Conclusion: The mechanism of DMDAI-L in inducing HL-60 cells apoptosis may involve the activation or regulation of caspase-3 activity as well as the reduction of mitochondrial membrane potential in HL-60 cells within certain concentration and time range.

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.

[ 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.

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.

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 (P<0.05). However, the expression of MCM7 protein in HCC tissues of tree shrew were also higher than that in corresponding HCC-adjacent liver tissues and normal liver tissues, but no significant difference was found among three types of tissues (P>0.05).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 (P<0.05). However, no significant difference was found between HCC-adjacent liver tissues and normal liver tissues (P>0.05). 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.

This study aimed to analyze the etiology of the encephalitis outbreak in Longyan, Fujian Province, China in 2010, in order to provide valuable information for this prevention and control of this disease. Pathogens were confirmed from cerebrospinal fluid samples with fluorescent RT-PCR, virus isolation (RD cells), and neutralization tests. Then, the VP1 fragments or whole genome nucleotide sequences were determined for four virus strains using PCR. Homology was assessed using the MegAlign software, and a phylogenetic evolutionary tree was drawn using Mega 4.0 software. The results confirmed that the etiology of the outbreak was the ECHO6 intestinal virus, and the nucleotide sequence of the VP1 segment indicated that the C2 subtype was responsible. The genome sequence consisted of 7407 nucleotides, and resembled the genome of other ECHO and CoxB viruses with homology levels of 78.5%-87.3%. The encephalitis outbreak in Longyan in 2010 was caused by the ECHO6 C2 subtype intestinal virus, and its complete genome sequence length is similar to the standard strain (U16283) with a sequence homology of 80.4%.
Child, Preschool ; China ; epidemiology ; Disease Outbreaks ; Echovirus 6, Human ; classification ; genetics ; isolation & purification ; Echovirus Infections ; epidemiology ; virology ; Encephalitis ; epidemiology ; virology ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Phylogeny

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.

The aim of the present study was to testify whether the reactive oxygen species and mitochondrial ATP-sensitive potassium (K(ATP)) channels were involved in the cardioprotection induced by tumor necrosis factor alpha (TNF-alpha) in the cultured neonatal ventricular myocytes suffered from 12 h of hypoxia and 6 h of reoxygenation. We tested the release of lactate dihydrogenase (LDH) and manganese superoxide dismutase (Mn-SOD) with spectrophotometry. It was shown that pretreatment with TNF-alpha (10, 50, 100, or 500 U/ml) significantly increased the Mn-SOD activity and reduced LDH release in the neonatal ventricular myocytes subjected to hypoxia and reoxygenation. Pretreatment with NAC (1 mmol/L), antimycin A (50 micromol/L), 2-MPG (400 micromol/L), DDC (100 nmol/L) or 5-HD (100 micromol/L), respectively, attenuated the increase in Mn-SOD activity and reduction of LDH level induced by TNF-alpha in ventricular myocytes. Diazoxide (50 micromol/L), a selective opener of the mitochondrial K(ATP) channel, decreased the LDH release of the myocytes subjected to hypoxia and reoxygenation, which could be abolished by pretreatment with NAC (1 mmol/L) or 5-HD (100 micromol/L). These results suggest that oxygen radical signals and mitochondrial K(ATP) channels are involved in the cardioprotection induced by TNF-alpha.
Animals ; Animals, Newborn ; Cell Hypoxia ; Cells, Cultured ; Heart Ventricles ; cytology ; KATP Channels ; metabolism ; Mitochondria, Heart ; metabolism ; physiology ; Myocardial Ischemia ; metabolism ; Myocardial Reperfusion Injury ; physiopathology ; prevention & control ; Myocytes, Cardiac ; cytology ; Oxygen ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology

AIM:To investigate the effect of recombinant lentiviral vector for RNA interference (RNAi) on the expression of fatty acid-binding protein 5 (FABP5) gene in hepatocellular carcinoma HepG2 cells and tumor formation in nude mice.METHODS:RNAi lentiviral vector was used in the experiment.Human hepatocellular carcinoma HepG2 cells were divided into 3 groups:the HepG2 cells in experimental group were transfected with the recombinant lentivirirus vector LV-shRNA-FABP5, the cells in negative control group were transfected with a control lentiviral vector LV-shRNA-NC, and the cells in normal control group were without any treatment.The nude mice were randomly divided into 3 groups.The growth of the transplanted tumor cells in the nude mice was observed.The tumor growth curve, volume and weight were de-termined 4 weeks after the cell inoculation.The expression of FABP5 was detected by real-time PCR, Western blot and im-munohistochemical staining.RESULTS:Transfection of the lentiviral vector FABP5-shRNA obviously reduced FABP5 ex-pression in the HepG2 cells.Tumor formation was all positive in the 3 groups of the nude mice inoculated with the tumor cells.Compared with normal control group and negative control group, the tumor growth slowed significantly in experimental group with smaller volume and weight.FABP5 expression in the transplanted tumor tissues was significantly down-regulated at mRNA and protein levels in experimental group as compared with normal control group and negative control group. CONCLUSION:RNAi-induced down-regulation of FABP5 effectively inhibits the growth of transplanted hepatocellular carcinoma, suggesting that FABP5 gene may be an effective target for gene therapy in treating liver cancer.