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OBJECTIVE：To study the i mprovement effects of α-lipoic acid on glucose metabolism disorder of insulin resistant HepG2 cells. METHODS ：The effects of 25-1 000 µmol/L α-lipoic acid on survival rate of human hepatoma cell HepG2 were determined by MTT assay so as to determine the concentration of α-lipoic acid. Negative control group ，insulin resistance group （1× 10－7 mol/L insulin ），combination resistance group （30 µmol/L sodium arsenite+ 1×10－8 mol/L insulin ），α-lipoic acid low- concentration，medium-concentration and high-concentration groups were set up. HepG 2 cells were treated with α-lipoic acid for 12 h and then cultured with corresponding concentration of sodium arsenite or/and insulin for 24 h. The glucose oxidase method was used to detect the glucose consumption ，colorimetric method was used to detect hexokinase activity and pyruvate kinase activity ， and anthrone method was used to detect glycogen content. Western blot assay was used to detect the protein expression of GLUT 4， p-GSK3β and GSK3β as well as the ratio of p-Akt/Akt and p-GSK3β/GSK3β. RESULTS：25，50，100 µmol/L α-lipoic acid had no significant effect on the survival rates of HepG 2 cells（P＞0.05），and survival rates of H epG2 cells were higher than 96％，so they were used as the low ，medium and high concentration for follow-up study. Compared with negative control group ，glucose consumption，the activities of hexokinase and pyruvate kinase ，glycogen content ，protein expression of GLUT 4 and p-GSK 3β，the ratio of p-Akt/Akt and p-GSK 3β/GSK3β were decreased significantly in insulin resistance group and combined resistance group， while the protein expression of GSK 3β was increased significantly（P＜0.05）. Compared with combination resistance group ，the glucose consumption （except for α-lipoic acid low- concentration group ），the activities of h exokinase（except for α-lipoic acid low-concentration and medium-concentration groups ） andpyruvate kinase （except for α-lipoic acid low-concentration com and medium-concentration groups ）， glycogen contents ， protein expression of GLUT 4 （except for α-lipoic acid mail：bliang163@163.com low-concentration group ）and p-GSK3β，the ratio of p-Akt/ Akt（except for α-lipoic acid low-concentration and medium-concentration groups ）and p-GSK 3β/GSK3β（except for α-lipoic acid low-concentration groups ）were increased significantly in α-lipoic acid groups ，while protein expression of GSK 3β（except for α-lipoic acid low-concentration and medium-concentration groups ） was decreased significantly （P＜0.05）；glycogen content ， protein expression of GLUT 4 and the ratio of p-GSK 3β/GSK3β in α-lipoic acid high-concentration group as well as the protein expression of p-GSK 3β in α-lipoic acid medium-concentration and high-concentration groups were improved significantly （P＜0.05）. CONCLUSIONS：α-lipoic acid can improve the disorder of glucose metabolism in insulin resistant HepG 2 cells，the mechanism of which may be associated with the increase of glucose consumption ，the activities of glucose metabolism related enzymes and glycogen content ，and expression up-regulation of the phosphorylation levels of Akt and GSK 3β protein，the expression of GLUT 4 and p-GSK 3β proteins，down-regulation of the expression of GSK 3β protein.
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To investigate the antihyperglycemic and antioxidant activity of the total flavones of Potentilla kleiniana Wight et Arn. [TFP] in streptozotocin [STZ] induced diabetic rats. STZ-induced diabetic rats were treated with TFP weekly for 4 weeks at three doses [100 mg/kg, 200 mg/kg and 400 mg/kg]. Blood glucose levels [BGL], body weight, insulin, total cholesterol [TC], triglyceride [TG], high density lipoprotein [HDL], very low density lipoprotein [VLDL], low density lipoprotein [LDL], malondialdehyde [MDA], glutathione [GSH], super oxide dismutase [SOD] and catalase [CAT] levels of liver and pancreas were measured weekly for 4 weeks. STZ administration resulted in oxidative damage of pancreas, then hyperglycemia proved by higher MDA, lower insulin and higher BGL in comparison to normal rats. TC, TG, LDL and VLDL cholesterol levels were also significantly elevated with decreased GSH, SOD, and CAT levels. A steady decrease in BGL and increase in insulin level were observed 4 weeks after TFP treatment in a dose dependent manner, as well as remarkable improvement in body weight and biochemical parameters. TFP have the effect of inhibiting hyperglycemia and oxidative stress, and the administration may be helpful in the prevention of diabetic complications associated with oxidative stress
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Animals, Laboratory , Male , Streptozocin , Hypoglycemic Agents/pharmacology , Antioxidants/pharmacology , Phytotherapy , Plants, Medicinal , Rats, WistarABSTRACT
Aim To isolate cancer stem cells from human pan-creatic cancer cell line L3. 6pl and to identify their biological characteristics. Methods L3. 6pl cells were cultivated in com-mercial low adhesion plate with serum-free stem cell culture me-dium ( MEM/F12 1:1 ) supplemented with B27. The cancer stem cells reformed into floating spheres were isolated. The method of tumor sphere formation was used to isolate/enrich and characterize the cancer stem cells in pancreatic carcinoma cell line L3. 6pl. Cancer stem cell spheres were collected and sorted using magnetic cell sorting ( magnetic activated cell sorting, MACS) technology, with the cell surface markers of CD24 +CD44 + ESA+. Self-renewal and EMT-related oncogene expres-sion were measured with Western blot. Cancer stem cells differ-entiation potential and the expression of cancer stem cell related signs were checked with Immunofluorescence assay. To deter-mine tumorigenesis in vivo, Xenograft assay in NOD-SCID mice were performed respectively, then immunohistochemistry proto-oncogene c-Met and RON expression were also checked. West-ern blot was used to detect the changes of stemness relative tran-scriptional factors and epithelial markers expressed in spheres before and after differentiation. Drug resistance of pancreatic cancer stem cells to gemcitabine or paclitaxel was measured with MTT assay. Results CD24 + CD44 + ESA+ cells were signifi-cantly tumorigenic, and cultured in serum-free conditions to form spheroids, which had the characteristics of stem cells with self-renewal, EMT and drug-resistant capabilities, and had a posi-tive correlation with the c-Met, RON protein expression. Con-clusion Human pancreatic stem cells are successfully isolated, which provides a useful model for individualized therapy and e-valuation of the therapeutic efficacy for pancreatic cancer pa-tients.
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In this paper,we made an analysis of the organization and content settings of medical laboratory students' summer clinical practices,and summarizes the students' achievements and experience of clinical practices in many years.Standardized organization and reasonable content settings are the guarantees for the students to have a comprehensive understanding of the basic major contents.Through the summer clinical practices,students can have a good understanding of their major in short period of time.
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Graduation practice of clinical laboratory profession is the important link of the teaching.In this stage,it is necessary for the students to adapt to the transition role and the thought method,and deal with interpersonal relation,cultivate noble professional ethics,master skills as soon as possible and get aware of the protection of the safe medical treatment to avoid the medical entanglement.It is also very important to accelerate personal skill,increase practice result and cultivate talented persons.
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Objective To study the genetic diversity of different geographical populations of Houttuynia cordata in China.Methods The genetic diversity of 15 geographical populations of H.cordata from 13 provinces in China was estimated using amplified fragment length polymorphism(AFLP) markers.The data of amplified bands were analyzed by the software POPGENE and MEGA.Results The ten AFLP primers employed produced a total of 110 discernable and reproduceable amplified fragments.The percentage of polymorphic bands within different populations was 70.51%.Genetic diversity analysis showed that effective number of alleles(Ne) was 1.210,Nei′s gene diversity(H) was 0.119,and Shannon′s genetic diversity index(I) was 0.186.The coefficient of genetic distance was 0.008 9—0.181 8 among populations.A UPGMA dendrogram based on Nei′s(1972) genetic distance visualized that the 15 populations were grouped into three different clusters,Emei population was one individual cluster group and the other populations were grouped into two different clusters corresponding to the different geographical areas.Conclusion The genetic diversity within different geographical populations of H.cordata in China is plentiful.
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Objective To study the genetic diversity of germplasm resources for Potentilla discolor.Methods Twelve species of germplasm resources for P.discolor were analyzed by ISSR molecular markers.To make up the systematic diagram of genetic relationship by POPGENE 1.32 software,cluster by UPGMA method,and establish the dendrogram.Results A total of 128 ISSR bands were scored for 12 primers,among which 101 were polymorphic bands.The average percentage of polymorphic bands was 78.91%.Genetic similarity coefficient was changed from 0.179 2 to 0.632 5.By cluster analysis,the geographical distribution is mutually related to the relationship of germplasm resources for P.discolor and it was also showed some of P.discolor from the same region were in the same group which presented the rule of geographical distribution in the tested materials.Conclusion The diversity level of the different germplasm resources for P.discolor higher and the relationship of P.discolor correlates with the geographical location in some way.