Effect of Puerarin in Reducing Insulin Resistance in HepG2 Cells via PI3K/Akt/GSK-3β Signal Transduction Pathway / 中国实验方剂学杂志

Objective: To observe the effect of puerarin on phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β) in insulin resistant HepG2 cells. Method: HepG2 cells were treated with palmitic acid 0.5 mmol·L-1 and insulin 9×10-4 U·L-1 to induce insulin resistant condition for 24 h. Cell viability was detected by methyl thiazolyl tetrazolium (MTT) assay to determine the concentration of puerarin. This experiment included normal control group, model control group and puerarin groups of different doses (40, 80, 160,320 μg·L-1). Glucose detection kit was used to detect the content of glucose in cell culture supernatant. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) levels in supernatant of cell culture medium were detected by enzyme-linked immunosorbent assay (ELISA). Hepatic glycogen assay kit was used for detecting the hepatic glycogen content in HepG2 cells. Western blot was applied to detect protein expression levels of PI3K, Akt, p-Akt, GSK-3β and p-GSK-3β. Result: Compared with those in the normal control group, the glucose consumption rate was significantly down-regulated in HepG2 cells in the model control group (PPα and IL-6 were increased in supernatant of cell culture medium (PPβ protein expression was up-regulated (PPα and IL-6 were reduced in supernatant of cell culture medium (PPβ protein expression was down-regulated, but its phosphorylation inactivation was increased (PConclusion: Puerarin alleviates the insulin resistance of HepG2 cells by strengthening the PI3K/Akt/GSK-3β signal transduction process and increasing the glycogen content in hepatocytes.

New EMA real-time fluorescence PCR method for detection of alive Listeria monocytogenes in foods / 中国人兽共患病学报

A new EMA real-time fluorescence PCR method was developed to detect alive Listeria monocytogenes in foods.The specific primers and probe were designed based on the conserved inlA gene.The pretreatment conditions including EMA of different concentrations and irradiating times were optimized.The detection limit and inhibition rate to dead bacteria of this method were confirmed by using direct plating method.The detection specificity was evaluated by using 35 L.monocytogenes strains,25 non-L.monocytogenes strains and 92 non-Listeria strains.Simulation detection experiments were performed on 15 beverage samples and 15 cooked meat samples supplemented separately with inactivated L.monocytogenes,alive L.monocytogenes and Staphylococcus aureus.Results showed that the Ct of EMA real-time fluorescence PCR for alive L.monocytogenes was Ct=38.46-3.30 × log (R2=0.999).The detection limit was 55 cfu per reaction.Inhibition rate of DNA of inactivated strains was over 99.98％.The Ct of 35 L.monocytogenes strains were between 16.21 and 29.38,while 25 non-L.monocytogenes strains and 92 non-Listeria strains had Ct ＞35.The variation coefficient of CT was less than 5％ when the experiments were repeated.Results of 30 simulation samples were consistent with that by using standard method.The test time by using newly developed EMA real-time fluorescence PCR was shortened from 3-5 days to about 10 h.The newly developed EMA real-time fluorescence PCR method for alive L.monocytogenes is rapid,convenient,specific and sensitive and could be applyed in foods inspection.

Influence on costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the influence on costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site.</p><p><b>METHODS</b>16 rabbits (8-10 weeks old, 1.8-2.2 kg) were randomly divided into four groups as three experimental groups and one control group. The 1.5 cm in length of costal cartilage defect was made in experimental groups with the perichondrium and costochondral junction left completely intact. The cartilage defect was closed by 3 methods as saturation directly, or replanting the small blocks of autogeneic cartilage, or plugging bio-protein jelly after cartilage replanting. Each experimental group was handled with two methods in two sides of costal cartilage. No operation was performed in control group. All the rabbits were sacrificed 16 weeks after operation. The appearance of thoracic cage and new-formed tissue at the defect site were examined grossly. Haematoxylin-eosin staining was performed to evaluate the characteristics of new-formed tissues and biomechanical detection was used to measure intension of new-formed tissues.</p><p><b>RESULTS</b>The appearance of thoracic cage was normal in every experimental group. Histological study showed that the defect was filled with abundant fibrous tissue in each group. The chipping of cartilage survived effectively with little proliferation. Biomechanical detection showed that the intension of new-formed tissue in the non-replanted group [(193.92 +/- 41.41) N] was obviously less than that in the replanted group [(318.88 +/- 28.28) N], or bio-protein jelly group [(301.00 +/- 39.52) N], or control group [(300.54 +/- 38.35) N] (P < 0.01). Furthermore, there was no statistical difference between the latter three groups (P > 0.05).</p><p><b>CONCLUSIONS</b>Although replanting the chipping of cartilage can't promote reparative regeneration of hyaline cartilage, it can definitively strengthen the intensity of new-formed tissue, reinforce thoracic stability. It may also indirectly decrease the incidence rate of postoperative chest wall deformity.</p>