Biomedical subjects

Fei Xiao

Publications and source records attributed to Fei Xiao.

28 records · Page 2Linked to original sources

PubMed2004

[Construction of recombinant adenovirus for the angiogenic inhibitor, vasostatin, and its expression in vitro].

OBJECTIVE: To construct a recombinant replication-deficient adenovirus for the angiogenic inhibitor, vasostatin and assay its expression in vitro. METHODS: The cDNA for vasostatin was got by PCR amplification, then it was cloned into T vector and confirmed by enzymatic analysis and direct sequencing. Subsequently the cDNA was subcloned into the shuttle plasmid, and co-transformed into 293 cells with backbone plasmid. The resulting recombinant andenovirus was confirmed by PCR and western blot. The activity was assayed by inhibition of HUVEC growth. RESULTS: The PCR product was about 590 bp in length, and sequencing result was identical to that reported. The construction of recombinant replication-deficient adenovirus was confirmed by PCR. Western blot analysis showed the expression of vasostatin in vitro. The supernatant from transduced HeLa cells inhibited the growth of HUVEC specifically. CONCLUSION: The recombinant adenovirus for vasostatin efficiently mediated the expression of the protein in vitro.

Adenoviridae↗

PubMed2004

[Changes of energy metabolism in canine respiratory muscles after phrenic nerve transection].

OBJECTIVE: To examine the changes in energy metabolism in the respiratory muscles of canines with unilateral phrenic nerve transection using high-performance liquid chromatography (HPLC). METHODS: The left phrenic nerve of 8 canines was transected and the contents of adenine nucleotide in respiratory muscles were determined by HPLC before and 1 and 2 months after the operation. RESULTS: In the intercostal muscles, ATP contents remained almost unchanged during the entire course of the observation, while ADP content was elevated 2 months after the operation as compared with that measured before and 1 month after the operation (P<0.05). One month postoperatively, the content of total adenylic acid (TAN) decreased to the lowest point, but the difference between the measurements was not statistically significant; also at 1 month after the operation, the content of adenylate energy charge (AEC) was the lowest, with statistically significant difference from the measurements before and 2 months after the operation (P<0.05). In the diaphragm, the contents of ATP, ADP, TAN and AEC 2 months postoperatively were 9.05+/-12.70, 2.99+/-2.57, 14.72+/-13.98, 0.57+/-0.29, significantly different from the levels at the other two time points (P<0.05). CONCLUSION: After unilateral phrenic nerve transection in canines, the energy metabolism of the diaphragm declines significantly, whereas that of the intercostal muscle can be compensated to some extent.

Adenine Nucleotides↗

PubMed2004

[Studies on the analgesic and anti-inflammatory effect of bornyl acetate in volatile oil from Amomum villosum].

OBJECTIVE: To study analgesic and anti-inflammatory effects of bornyl acetate, the main ingredient of Amomum villosum volatile oil. METHODS: The analgesic effects were tested by hot-plate and writhing reaction method, the ear swelling caused by dimethylbenzene in mice. RESULTS: Bornyl acetate could restrain writhing reaction caused by acetic acid glacial, lighten the pain caused by hot-plate. It could also suppress ear swelling caused by dimethylbenzene in mice. CONCLUSION: Bornyl acetate shows analgesic and anti-inflammatory effects.

Amomum↗

PubMed2004

Down-regulation amyloid beta-protein 42 production by interfering with transcript of presenilin 1 gene with siRNA.

AIM: To investigate the pathogenesis of Abeta42 yielding and new drug targets as well as the possibility of RNA interference (RNAi) technique for treatment of Alzheimer disease (AD). METHODS: Human AD presenilin 1 (PS1) cDNA sequence was obtained from NCBI website. The three sites of RNAi action and one missense control site were selected in PS1 cDNA through online design of Ambion company. To confirm specificity of these sites, we conducted a BLAST search of the IMAGE EST library. The corresponding double-stranded DNA was used to construct pSilencer 3.1-H1 plasmid, which could transcribe small interference RNA (siRNA). Then, the pSliencer 3.1-H1 plasmids were transfected into CHO/PS1/APP cells with SuperFect transfection reagent. The cells have been transfected with the mutant PS1 and APP gene of AD. All the CHO/PS1/APP cells with pSliencer 3.1-H1 plasmids were screened out using G418. Transcripts of PS1 gene in CHO/PS1/APP were measured by RT-PCR, the contents of PS1 peptide and Abeta42 production inside CHO/PS1/APP cells were examined through Western blot and the Abeta42 change of secretion by CHO/PS1/APP was determined with ELISA. RESULTS: The site 3 of PS1 mRNA was inhibited by RNAi after 2 d. The effect was more obvious with the time. The peptide corresponding to PS1 gene and Abeta42 production in CHO/PS1/APP cells were both reduced after siRNA interfere for 3 d. Abeta42 secretion by CHO/PS1/APP cells began to reduce on d 3, and reached the most significance on d 5. There was a time-dependent relationship between the transcript of PS1 gene and the production of Abeta42 with RNAi action. CONCLUSION: PS1 is essential for g-secretase activity. Inhibition of the PS1 can decrease the levels of Abeta42. Some sites of PS1 mRNA, for example, the site 3, may serve as a new drug target and RNAi probably can be used for treatment of AD.

Alzheimer Disease↗

PubMed2004

[Effect of ginsenoside Rg1 on the influence of neprilysin expression induced by LPS in BT325 cell line].

OBJECTIVE: To investigate the effect of ginsenoside Rg1 on the influence of neprilysin expression induced by LPS in BT325 cell line. METHOD: MTT was used to measure the levels of the survival rate of BT325 cultured with ginsenoside Rg1 and LPS in different concentrations. The expression of NEP was measured by RT-PCR. RESULT: The survival rate of BT325 was obviously inhibited by LPS, and the expression of NEP was decreased. The survival rate of BT325 was obviously raised by ginsenoside Rg1, and the expression of NEP was increased. CONCLUSION: LPS can cause cell damage, and decrease the expression of NEP. Ginsenoside Rg1 can exert neuroprotective properties which protects BT325 cell line from the cell toxicity of LPS.

Cell Line, Tumor↗

PubMed2003

Inhibition of tumor growth with a vaccine based on xenogeneic homologous fibroblast growth factor receptor-1 in mice.

Angiogenesis is important for the growth of solid tumors. The breaking of the immune tolerance against the molecule associated with angiogenesis should be a useful approach for cancer therapy. However, the immunity to self-molecules is difficult to elicit by a vaccine based on autologous or syngeneic molecules due to immune tolerance. Basic fibroblast growth factor (bFGF) is a specific and potent angiogenic factor implicated in tumor growth. The biological activity of bFGF is mediated through interaction with its high-affinity receptor, fibroblast growth factor receptor-1 (FGFR-1). In this study, we selected Xenopus FGFR-1 as a model antigen by the breaking of immune tolerance to explore the feasibility of cancer therapy in murine tumor models. We show here that vaccination with Xenopus FGFR-1 (pxFR1) is effective at antitumor immunity in three murine models. FGFR-1-specific autoantibodies in sera of pxFR1-immunized mice could be found in Western blotting analysis. The purified immunoglobulins were effective at the inhibition of endothelial cell proliferation in vitro and at the antitumor activity in vivo. The antitumor activity and production of FGFR-1-specific autoantibodies could be abrogated by depletion of CD4+ T lymphocytes. Histological examination revealed that the autoantibody was deposited on the endothelial cells within tumor tissues from pxFR1-immunized mice, and intratumoral angiogenesis was significantly suppressed. Furthermore, the inhibition of angiogenesis could also be found in alginate-encapsulate tumor cell assay. These observations may provide a new vaccine strategy for cancer therapy through the induction of autoimmunity against FGFR-1 associated with angiogenesis in a cross-reaction.

Alginates↗

PubMed2003

Active immunogene therapy of cancer with vaccine on the basis of chicken homologous matrix metalloproteinase-2.

Matrix metalloproteinase (MMP) family, in particular MMP-2, may play a key role in angiogenesis and tumor growth. It is conceivable that the breaking of immune tolerance of MMP-2 should be a useful approach to cancer therapy by active immunity. To test this concept, we constructed a plasmid DNA encoding chicken homologous MMP-2 (c-MMP-2) and control vectors. We found that the vaccine based on chicken homologous MMP-2 as a model antigen could induce both protective and therapeutic antitumor immunity. Autoantibodies against MMP-2 in sera of mice immunized with c-MMP-2 could be found by Western blotting analysis and ELISA assay. There was the deposition of autoantibodies within the tumor. IgG1 and IgG2b were substantially increased in response to c-MMP-2 immunization. The elevation of MMP-2 in the sera of tumor-bearing mice was abrogated with the vaccination of c-MMP-2. Transmigration of human endothelial cells and tumor cells through gelatin-coated filters was inhibited with immunoglobulins isolated from mice immunized with c-MMP-2. The gelatinase activity of MMP-2, including both latent MMP-2 (M(r) 72,000) and active MMP-2 (M(r) 66,000) derived from tumor tissues, was apparently inhibited by the vaccination with c-MMP-2. The antitumor activity and the inhibition of angiogenesis were acquired by the adoptive transfer of the purified immunoglobulins. The antitumor activity and production of autoantibodies against MMP-2 could be abrogated by the depletion of CD4(+) T lymphocytes. Angiogenesis was apparently inhibited within tumor, and chick CAMs angiogenesis was also inhibited. Thus, our findings may provide a vaccine strategy for cancer therapy through the induction of an autoimmune response against MMP-2 in a cross-reaction by the immunization with the single xenogeneic homologous MMP-2 gene and may be of importance in the additional exploration of the application of other xenogeneic homologous genes identified in human and other animal genome projects in cancer therapy.

Animals↗

PubMed2003

[Study on pharmacokinetics of ferulic acid and paeoniflorin in Angelic-Paeonia root powder].

OBJECTIVE: To study pharmacokinetics of ferulic acid and paeoniflorin that are two chief active compounds in Angelic-Paeonia Root Powder (APRP). METHODS: After the mice were administered by APRP through ig, HPLC was used to determine ferulic acid and paeoniflorin concentration in serum at different times. 3P87 procedure was used to process concentration-time data. RESULTS: Ferulic acid and paeoniflorin were detected from serum in the mice. The pharmacokinetics parameters were: Ferulic acid: Ke = 0.330 +/- 0.085 1/h, Ka = 0.555 +/- 0.133 1/h, t1/2(ka) = 1.249 +/- 0.365 h, t1/2(ke) = 2.101 +/- 0.665 h, Tpeak = 2.606 +/- 0.586 h, Cmax = 6.372 +/- 1.510 mg.L-1, AUC = 41.399 +/- 11.763 mg.h-1.L-1; Paeoniflorin: Ke = 0.511 +/- 0.117 1/h, Ka = 0.656 +/- 0.121 1/h, t1/2(Ka) = 1.056 +/- 0.263 h, t1/2(Ke) = 1.356 +/- 0.281 h, Tpeak = 2.062 +/- 0.396 h, Cmax = 3.401 +/- 0.879 mg.L-1, AUC = 16.047 +/- 3.767 mg.L-1. The present research provided valuable data for rational clinical practice of APRP.

Angelica sinensis↗

PubMed2002

Immunogene therapy of tumors with a vaccine based on the ligand-binding domain of chicken homologous integrin beta3.

The breaking of immune tolerance against angiogenesis-associated molecules should be a useful approach for cancer therapy by active immunity. We used chicken integrin beta3 as a model antigen to explore the feasibility of immunogene therapy of the tumors with a vaccine based on a single xenogeneic homologous gene, targeting the molecules associated with angiogenesis. To test this concept we constructed a plasmid DNA encoding the ligand-binding domain of chicken integrin beta3 (P-BD-C) and control vectors. We found that immunogene therapy of tumors with a vaccine based on the ligand-binding domain of chicken integrin beta3 (P-BD-C) was effective in both protective and therapeutic anti-tumor immunity in several tumor models in mice. Autoantibodies against integrin beta3 in sera of mice immunized with the ligand-binding domain of chicken integrin beta3 could be found by Western blot analysis and ELISA assay. The purified immunoglobulins were effective in the inhibition of endothelial cell proliferation in vitro, and in anti-tumor activity as well as in the inhibition of angiogenesis by adoptive transfer in vivo. The anti-tumor activity and the production of integrin beta3-specific autoantibodies (manifested by significantly elevated Ig G1 and Ig G2b) could be abrogated by the depletion of CD4+ T lymphocytes. These observations may provide a vaccine strategy for cancer therapy through the induction of the autoimmunity against the molecules associated with tumor growth in a cross-reaction with a single xenogeneic homologous gene and may be of importance in the further exploration of the applications of other xenogeneic homologous genes identified in human and other animal genome sequence projects in cancer therapy.

Animals↗

PubMed2002

[The effect of Kadsura heteroclita on the cultured hippocampal neurons].

OBJECTIVE: The effects of different concentration Kadsura heteroclita extract (HS2) on the growth of newborn rat hippocampal neurons were observed by means of dissociated cell culture. METHODS: The newborn rat hippocampal neurons were cultured with different level HS2. The convert phase microscope was used to analyse the number and the length of neurites, as well as the maximum diameter of hippocampal neurons soma. The survival neurons count and LDH assay were carried out to investigate the effect of HS2 on the growth and development of neurons in different culture time. RESULTS: After 36h, the number and the length of neurites of 1 mg/ml HS2 group were increased and the maximum diameter of hippocampal neurons soma did not change. The 0.2 mg/ml HS2 group did not show statistical difference as compared with the control group, while 8 mg/ml HS2 inhibited notably the growth of neurons. The number of survival neurons of 1 mg/ml HS2 group was more than that of the control group, and the LDH activity of 1 mg/ml HS2 group was lower in different culture time. CONCLUSION: This study suggested that suitable dose HS2 can promote the growth and development of hippocampal neurons.

Animals↗