Comparative study of duloxetine pharmacokinetics in normal and diabetic rats / 药学学报

The study was aimed to establish a liquid chromatography-tandem mass spectrometric method for the determination of the duloxetine concentration in rat plasma, and compare the pharmacokinetics in normal and diabetes mellitus rat models. Diazepam was used as an internal standard. The separation was achieved on a Waters Xterra® RP18 column (100 mm × 4.6 mm, 3.5 μm) with a mobile phase consisting of methanol -0.3% formic acid containing 5 mmol·L-1 ammonium acetate (75:25) at the flow rate of 0.6 mL·min-1. Electrospray ionization source was applied and operated in the positive multiple reaction monitoring mode. A good linearity of duloxetine was obtained in the concentration range of 10-5 000 ng·mL-1. The rat models of diabetes mellitus were established by intraperitoneal injection of streptozotocin. The same dose of duloxetine (40 mg·kg-1) was given by intragastric administration to the normal and diabetic rats. Blood samples were collected from the orbital venous plexus to determinate duloxetine concentration in the plasma. The pharmacokinetic parameters were calculated by DAS software. Statistical analysis was performed by SPSS software. The major pharma-cokinetic parameters of diabetes group were as follows: Cmax was 1 185 ± 190.0 ng·mL-1; AUC0-∞ was 8 398 ± 1 835 ng·mL-1·h; tmax was 1.6 ± 0.4 h; t1/2z was 3.6 ± 0.9 h. The major pharmacokinetic parameters of normal group were as follows: Cmax was 368.1 ± 40.7 ng·mL-1; AUC0-∞ was 4145 ± 640.1 ng·mL-1·h; tmax was 1.6 ± 0.3 h; t1/2z was 4.1 ± 0.8 h. The results of pharmacokinetic experiments suggest that the exposure amount of duloxetine in diabetic rats is twice higher than that in normal rats.

An experimental study on chemoprevention of esophageal adenocarcinoma by celecoxib, a selective cyclooxygenase-2 inhibitor / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the feasibility of chemoprevention of esophageal adenocarcinoma by celecoxib, a selective cyclooxygenase-2(COX-2) inhibitor using a rat model.</p><p><b>METHODS</b>Rats were divided into 3 groups: model group, celecoxib group, and control group. The rat surgical model was established by performing a gastrojejunostomy plus an esophagojejunostomy 5 mm distal to the gastrojejunal anastomosis. Twenty-eight weeks after surgery, all the animals were sacrificed and the pathological changes in the esophagus were examined macroscopically. COX-2 expression was analyzed by immunohistochemistry. Prostaglandin E2(PGE2) level was measured by enzyme-linked immunosorbent assay(ELISA).</p><p><b>RESULTS</b>The incidence of Barrett's esophagus and esophageal adenocarcinoma in the model group was 84% and 57% respectively, significantly higher than those in the control group(P<0.01). The incidence of esophageal adenocarcinoma in the celecoxib-treated group was significantly lower than that in the model group(P<0.01), and no esophageal adenocarcinoma was detected in the control group. COX-2 expression was detected in 100% of reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma, but not found in the normal tissue from the esophagus and the jejunum(P<0.01). The PGE2 level in the esophageal tissue in the model group was significantly higher than that in the control group(P<0.01). Rats in the celecoxib-treated group had significantly lower PGE2 level than that in the model group(P<0.01). The PGE2 levels were significantly higher in rats with cancer than those without cancer(P<0.01).</p><p><b>CONCLUSION</b>Celecoxib successfully prevents the development of esophageal adenocarcinoma in a rat surgical model with mixed reflux of acid and duodenal juice and significantly decreases the risk of Barrett esophagus developing esophageal adenocarcinoma. COX-2 maybe an effective selective target of chemoprevention for esophageal adenocarcinoma.</p>

Study on inter-individual variability of cerebral response to acupuncture with fMRI / 中国针灸

<p><b>OBJECTIVE</b>Effects of inter-individual variability on fMRI of acupuncture were observed and the possible influencing factors were further analyzed.</p><p><b>METHODS</b>Twenty-six healthy volunteers were selected. And acupuncture was applied at Zusanli (ST 36) on the left side with even manipulation. The same experimental designation and data collecting reference were adopted to collect functional data. Then, the same data processing method was applied for analyzing individual data. Data which did not confirm with data analyzing qualification were rejected. The 26 individual data which met the requirement were taken randomly for 5 times according to the principle of random group division. Five groups named with A, B, C, D and E were thus generated with 11 samples in each. Images were processed with the AFNI software for every group, and the activated brain areas were revealed.</p><p><b>RESULTS</b>Activated areas in the brain were observed in all the 5 groups, and the results vary a lot among different groups. Decreased signals of activated brain areas were observed in group C, while increased signals were seen in group D. Partial increasing and partial decreasing signals appeared in the other 3 groups. Compared with other groups, group D demonstrated totally different activated areas. The rate of difference among different groups is 46.7%-100.0%, and most of the differences were over half of the activated areas.</p><p><b>CONCLUSION</b>Under the pre-requisites of strict control of experimental designation, acupuncture method, data collecting and processing, great differences have been found in the activated areas of the brain. It indicates that obvious individual differences existes in the activated areas of the brain with acupuncture. And the difference may greatly influence the researching result of fMRI as well as conclusions of those results.</p>

Inhibitory effect of VPA on multiple myeloma U266 cell proliferation and regulation of histone acetylation / 中国实验血液学杂志

This study was aimed to investigate the effects of sodium valproate (VPA) on the proliferation and regulation of histone acetylation of multiple myeloma cell line U266. U266 cells were treated with VPA. Cell proliferation was determined by CCK-8 assay, and cell cycle were analyzed by flow cytometry (FCM). The expression level of HDAC1 mRNA was detected by RT-PCR, and the protein levels of HDAC1 and histone H3, H4 acetylation was detected by Western blot. The results showed that the VPA inhibited the proliferation of U266 cells in concentration-and time-dependent manners.After exposure to different concentrations of VPA for 48 hours, the proportion of G(0)/G(1) cells increased, while the proportion of S phase cells decreased. The cell cycle was arrested obviously in G(0)/G(1) phase (p < 0.05). The expression of HDAC1 mRNA was inhibited, and the protein level of HDAC1 was down-regulated, while the histone H3/H4 acetylation was up-regulated in U266 cells. It is concluded that the VPA can inhibit cell proliferation of U266 and induce G(0)/G(1) phase arrest. The increase of histone H3/H4 acetylation resulting from inhibiting HDAC1 by VPA might be considered as a possible mechanism.

Mechanism of As(2)O(3) on hdpr1 gene demethylation in Jurkat cell line / 中国实验血液学杂志

This study was purposed to investigate the effect of As(2)O(3) on the demethylation of anti-oncogene-hdpr1 gene of acute lymphoblastic leukemia cell line Jurkat in vitro and its mechanism. The inhibitory effect of As(2)O(3) on the proliferation of Jurkat cells was assayed by CCK-8; the change of Jurkat cell cycle was detected by flow cytometry before and after using As(2)O(3); the effect of As(2)O(3) on the methylation model of hdpr1 gene was analyzed by methylation-specific PCR, and the effect of As(2)O(3) on the expression of hdpr1 mRNA was analyzed by semiquantitative RT-PCR. The results showed that the proliferation rate of Jurkat cells was decreased significantly after being treated with As(2)O(3), and in dose-and time-dependent manner; As(2)O(3) blocked Jurkat cell cycle in G(0)/G(1) phase in dose-dependent manner. As(2)O(3) could reverse hypermethylation of hdpr1 gene and induce its mRNA reexpression, and down-regulate the dnmt1, dnmt3a, dnmt3b mRNA expression level also in dose-dependent manner. It is concluded that the As(2)O(3) suppresses the proliferation of Jurkat cells and blocks cell cycle is G(0)/G(1), its possible mechanism may be down-regulating mRNA expression level of dnmt1, dnmt3a and dnmt3b, induce demethylation of hdpr1 gene from abnormal hypermethylation status and activates its reexpression.

Investigation on the mechanisms of p15INK4B gene demethylation by valproate in Molt-4 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the antitumour effects of sodium valproate (VPA) on the proliferation, differentiation and cell cycle of Molt-4 cell and to investigate its demethylation mechanisms.</p><p><b>METHODS</b>After Molt-4 cells trated with VPA at different concentrations, cell viability and growth curve were assessed by MTT assay. Cell cycle changes were analyzed by flow cytometry. The expression level of p15, DNA methyltransferase 1 (DNMT-1), DNMT3A and 3B mRNA were detected by RT-PCR and the methylation level was detected by hn-MSPCR.</p><p><b>RESULTS</b>VPA significantly inhibited the proliferation of Molt-4 cells. After 48 h culture with 5.0 mmol/L VPA, the percentages of Molt-4 cells in G(0)/G(1) phase was (66.87 ± 3.31)% and in S phase was (8.47 ± 2.56)%, while in control group, the cells in G(0)/G(1) phase increased and in S phase decreased significantly. The p15 gene in Molt-4 cells failed to express due to its hypermethylation. The expression level of p15 gene mRNA increased significantly after exposure to VPA for 48 h. As compared with control group, the expression of DNMT-1 was down-regulated in a dose-dependent manner. The expression level of DNMT3B decreased at 10.0 mmol/L concentration.</p><p><b>CONCLUSION</b>VPA has a demethylation effect on p15 INK4B gene by inhibiting the DNMT-1 and DNMT3B gene activities to recover p15 gene activity, which arrests Molt-4 cell in G(0)/G(1) phase.</p>

Methylation status of CpG islands in secreted frizzled-related protein gene promoter region of malignant hematopoietic cell lines / 中国实验血液学杂志

To investigate the methylation status of CpG islands of the secreted frizzled-related protein (SFRP) gene promoter region in malignant hematopoietic cell lines, and to explore the possible relationship of CpG abnormal methylation status with pathogenic mechanism of hematologic malignancies. Methylation-specific PCR was used to detect the status of SFRP gene promoter region in nine malignant hematopoietic cell lines and peripheral blood mononuclear cells from healthy people. The results indicated that hypermethylation of 2 genes coding for SFRP1 and 2 were present in nine malignant hematopoietic cell lines, however, methylation and unmethylation of SFRP4 were both detected in CA46, HL60 and U937 cell lines, and SFRP5 in U266 as well. None of the normal mononuclear cells showed methylation of SFRP 1-5 genes. It is concluded that the hypermethylation of SFRP genes is related to the evolution of malignant hematopoiesis. Methylation of SFRP genes may serve as potential independent biomarkers for early detection of hematologic malignancies.