Biomedical subjects

Zhi-fang Yang

Publications and source records attributed to Zhi-fang Yang.

4 recordsLinked to original sources

PubMed2006

[Decrease of FOXP3 mRNA in CD4+ T cells in latent autoimmune diabetes in adult].

OBJECTIVE: To study the percentage of peripheral blood CD4(+)CD25(+) T cells and the expression of FOXP3 mRNA in the patients with latent autoimmune diabetes in adult (LADA). METHODS: Fresh peripheral blood samples were obtained from 60 patients with LADA, 30 patients with type 2 diabetes and 30 age- and sex-matched matched healthy nondiabetic control subjects without diabetic family history. Two-color staining (anti-CD4, anti-CD25, anti-CD3, and anti-CD8) flow cytometric analysis was employed to measure the CD4(+)CD25(+) T cells. The CD4 positive human cells were isolated with immunomagnetic beads, and then real time-PCR was used to test the expression of FOXP3 mRNA in the CD4(+) T cells. RESULTS: In the LADA group, the percentage of CD4(+)CD25(+) T cells was 4.1 +/- 1.9, significantly higher than that of the normal control group (2.8 +/- 1.5, P < 0.01), the ratio of CD4(+)CD25(+) to the CD4(+) T cells was 11.9 +/- 5.0, significantly higher than that of the normal control group (8.2 +/- 3.7, P < 0.01), the percentage CD8(+) T cells was 24.6 +/- 6.8, significantly higher than that of the normal control group (19.4 +/- 7.1, P < 0.01) and the CD4(+)/CD8(+) ratio was 1.5 +/- 0.5, significantly lower (1.9 +/- 0.6, P < 0.01). The expression of FOXP3 mRNA in CD4(+) T cells of the LADA group was 0.52 time that of the control group (P < 0.01). The CD4(+)/CD8(+) ratio of LADA group was significantly lower that of the type 2 diabetes group (1.8 +/- 0.8, P < 0.05), however, the other results were not significantly different between these 2 groups. The percentage of was positively correlated with the titer of glutamic acid decarboxylase antibody (GADA) (r = 0.292, P < 0.05). CONCLUSION: Though the percentage of CD4(+)CD25(+) T cells and the level of CD25 expression in CD4(+) T cells are elevated, the expression of FOXP3 mRNA in CD4(+) T cells is lower. in the patients with LADA. The regulatory T cells may have defective suppressor function in patients with LADA.

Adult↗

PubMed2006

Electrophysiological effect of fluoxetine on Xenopus oocytes heterologously expressing human serotonin transporter.

AIM: To investigate the electrophysiological effect of fluoxetine on serotonin transporter. METHODS: A heterologous expression system was used to introduce human serotonin transporter (hSERT) into Xenopus oocytes. A 2-electrode voltage clamp technique was used to study the pharmacological properties of fluoxetine. RESULTS: hSERT-expressing oocytes were perfused with 10 micromol/L serotonin (5-HT) to induce hSERT-current. The 5-HT-induced hSERT currents were dose-dependently reversed by fluoxetine. The RC50 (concentration that achieved a 50% reversal) was approximately 3.12 micromol/L. Fluoxetine took more time to combine with hSERT than 5-HT did, and it was also slow to dissociate from hSERT. This long-lasting effect of fluoxetine affected normal 5-HT transport. Fluoxetine significantly prolonged the time constant for 5-HT-induced hSERT current. These results might be used to explain the long-lasting anti-anxiety effect of fluoxetine in clinical practice, because it increases the concentration of 5-HT in the synaptic cleft by its enduring suppression of the function of 5-HT transporters. CONCLUSION: Fluoxetine inhibits 5-HT reuptake by competing with 5-HT and changing the normal dynamics of hSERT.

Animals↗

PubMed2005

[PTEN induces anoikis through its phosphatase activity in hepatocellular carcinoma cells].

OBJECTIVE: To investigate the effect and mechanisms of tumor suppressor gene PTEN on the induction of anoikis of hepatocellular carcinoma SMMC-7721 cells. METHODS: SMMC-7721 cells were transfected with GFP plasmids containing wild-type PTEN or phosphatase inactivating mutant PTEN (C124A-PTEN) in vitro; The PTEN expression and the phosphorylation levels of focal adhesion kinase (FAK) and protein kinase B (PKB/Akt) were detected by Western blotting; Flow cytometry assay and laser scanning confocal microscopy were used to analyze apoptosis in adherent and non-adherent cells. RESULTS: Compared with the control, PTEN expression in the cells transfected with wild-type PTEN increased to 248%, while the phosphorylation level of FAK and Akt decreased 65.2% and 89.1%, respectively; and the anoikis percentage increased from 9.5% to 31.3%. In the cells transfected with C124A-PTEN, neither the phosphorylation of FAK and Akt nor the anoikis percentage had obviously changed, although the PTEN expression enhanced dramatically in comparison with the control. CONCLUSION: Through its phosphatase activity, tumor suppressor gene PTEN can suppress the phosphorylation of FAK and Akt, and induce anoikis in hepatocellular carcinoma cells.

Anoikis↗

PubMed2004

[Effects of glimepiride and metformin on free fatty acid in patients with Type 2 diabetes mellitus].

OBJECTIVE: To investigate the effect of glimepiride and metformin on free fatty acid (FFA) in patients with Type 2 diabetes mellitus and to further study the relationship between free fatty acid and insulin resistance in patients with Type 2 diabetes mellitus. METHODS: A prospective and case-control study was conducted. Ninty-four patients with Type 2 diabetes mellitus (35-70 year-old) were divided into 3 groups: glimepiride treated group (n=33), metformin treated group (n=29) and glimepiride plus metformin treated group (n=32). These patients were followed up for 6 months. Free fatty acids were measured by using an enzymatic colorimetry. RESULTS: The concentration of FFA didn't significantly change in the glimepiride treated group at the end of treatment, but it obviously decreased in the metformin treated group and in the glimepiride plus metformin treated group (P < 0.05 and P < 0.001, respectively). The decrease of FFA in the glimepiride plus metformin treated group was more obvious than that in the glimepiride treated group (P < 0.05). The fasting serum FFA concentration is positively related to HOMA-IR( homeostasis model assessment-insulin resistance) and the choice of drugs by stepwise regression analysis. CONCLUSION: Metformin alone or metformin plus glimepiride can decrease FFA levels, body weight index, blood glucose and insulin resistance. FFA level can reflect the index of insulin resistance to some degree.

Adult↗