Biomedical subjects

Jie Ding

Publications and source records attributed to Jie Ding.

78 records · Page 5Linked to original sources

PubMed2002

Expression and bioactivity identification of soluble MG7 scFv.

AIM: To examine the molecular mass and identify the bioactivity of MG7 scFv for its application as a targeting mediator in gene therapy of gastric cancer. METHODS: Two strongly positive recombinant phage clones screened from MG7 recombinant phage antibody library were separately transfected into E.coli TG1. Plasmid was isolated from the transfected E.coli TG1 and digested by EcoR I and Hind III to examine the length of exogenous scFv gene. Then, the positive recombinant phage clones were individually transfected into E.coli HB2151. The transfectant was cultured and induced by IPTG. Perplasmic extracts was prepared from the induced transfectant by osmotic shock. ELISA was used to examine the antigen-binding affinity of the soluble MG7 scFv. Immunodotting assay was adopted to evaluate the yield of soluble MG7 scFv produced by transfected E.coli HB2151. Western blot was used to examine the molecular mass of MG7 scFv. Finally, the nucleotide sequence of MG7 scFv was examined by DNA sequencing. RESULTS: Two positive recombinant phage clones were found to contain the exogenous scFv gene. ELISA showed that MG7 scFv had strong antigen-binding affinity. Immuodotting assay showed that transfected E.coli HB2151 could successfully produce the soluble MG7 scFv with high yield via induction by IPTG. The molecular mass of MG7 scFv was 30 kDa by western blot. DNA sequencing demonstrated that the VH and VL genes of MG7 scFv were 363 bp and 321 bp,respectively. CONCLUSION: We have successfully developed the soluble MG7 scFv which possessed strong antigen-binding affinity.

Antibody Affinity↗

PubMed2002

Effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats.

AIM: To investigate the effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats. METHODS: Rats with cirrhosis induced by carbon tetrachloride were randomly divided into two groups, one n =13 receiving 0.5mg.kg(-1) per day of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, for 10 days, whereas the other group (n =13) and control (n =10) rats were administrated the same volume of 9g.L(-1) saline. Half gastric emptying time and 2h residual rate were measured by SPECT, using (99m)Tc-DTPA-labeled barium sulfate as test meal. Gastrointestinal transition time was recorded simultaneously. Serum concentration of nitric oxide (NO) was determined by the kinetic cadmium reduction and colorimetric methods. Immunohistochemical SABC method was used to observe the expression and distribution of three types of nitric oxide synthase (NOS) isoforms in the rat gastrointestinal tract. Western blot was used to detect expression of gastrointestinal NOS isoforms. RESULTS: Half gastric emptying time and trans-gastrointestinal time were significantly prolonged(124.0 +/- 26.4 min; 33.7 +/- 8.9 min; 72.1 +/- 15.3 min; P<0.01), (12.4 +/- 0.5h; 9.5 +/- 0.3h; 8.2 +/- 0.8h; P<0.01), 2h residual rate was raised in cirrhotic rats than in controls and cirrhotic rats treated with L-NAME (54.9 +/- 7.6%,13.7 +/- 3.2%, 34.9 +/- 10.3%, P<0.01). Serum concentration of NO was significantly increased in cirrhotic rats than in the other groups (8.20 +/- 2.48) micromol.L(-1), (5.94 +/-1.07) micromol.L(-1) and control (5.66 +/- 1.60 micromol.L(-1), P<0.01. NOS staining intensities which were mainly located in the gastrointestinal tissues were markedly lower in cirrhotic rats than in the controls and cirrhotic rats after treated with L-NAME. CONCLUSION: Gastrointestinal motility was remarkably inhibited in cirrhotic rats, which could be alleviated by L-NAME. Nitric oxide may play an important role in the inhibition of gastrointestinal motility in cirrhotic rats.

Animals↗

PubMed2002

[Development of oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer].

OBJECTIVE: To develop an oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer using attenuated Salmonella typhimurium and evaluate its efficacy and protective effect. METHODS: The eukaryotic expression vector including the MG(7)-Ag mimotope and a Th epitope was constructed, and then transduced into an attenuated Salmonella typhimurium to get the oral DNA vaccine. C57BL/6 J mice were orally immunized with 1 x 10(8) cfu Salmonella transfectants, with Salmonella harboring empty plasmid, with phophate buffered saline (PBS) as control. At the 6th week, serum titer of MG(7) antibody was detected by ELISA. In the 8th week, a [(3)H]-thymidine incorporation assay was performed to test the proliferation of murine spleen cells to the stimulant of MG(7)-Ag mimicry peptide. At the same time, Ehrlich ascites carcinoma cells expressing MG(7)-Ag were used in tumor challenge assay to evaluate the protective effect of the immunization. RESULTS: The oral DNA vaccine induced MG(7) antibody in mice, while in vivo unprimed proliferation assay of the spleenocytes showed no difference among the three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while none in the control group was protected. CONCLUSION: Oral DNA vaccine based on the MG(7)-Ag momitope is immunogenic. It is able to induce specific immunity response against tumor in mice, and the vaccine is partially protective.

Administration, Oral↗

PubMed2002

[Clinical research of patients with acute or chronic hepatic failure treated with molecular adsorbent recirculating system].

OBJECTIVE: To summarize the experience of a single treatment using molecular adsorbent recirculating system (MARS) in patients with acute-on-chronic liver failure. METHODS: Twenty-five eases treated by MARS-artificial liver were followed up and reviewed. RESULTS: The levels of serum total bilirubin, non-conjugated bilirubin and blood ammonia were significantly decreased from (618.51 200.68) mmol/L to (390.81 146.02) mmol/L (t=2.729, P<0.01), (490.03 163.39) mmol/L to (303.28 113.06) mmol/L (t =2.516, P<0.01), and (152.44 82.62)mmol/L to (84.80 13.30)mmol/L (t=2.174, P<0.05), respectively. Prothrombin activity was significantly increased from 70.55% 32.39% to 93.63% 14.20% (t=1.728, P<0.05) in patients during a single 6 h treatment with MARS. No difference was presented in the markers of liver zymogram, serum protein, kidney function, electrolyte, blood routine and blood gas analysis before and after the MARS. Thirteen of 17 patients have been cured or improved, 4 died, and the survival rate was 76.5%. CONCLUSIONS: MARS is a safe and an effective treatment for patients with liver failure.

Adult↗

PubMed2001

Investigation of Calcium Carbonate Scaling Inhibition and Scale Morphology by AFM.

The calcium carbonate scale inhibition by two inhibitors, polyacrylic acid (PAA) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), has been studied in two heat transfer systems: recirculating cooling water and pool boiling systems. It is found that PBTCA has a better inhibition effect than PAA under identical conditions. The inhibition effect increases with increasing fluid velocity for the cooling water system, whereas in the presence of inhibitors, the fluid velocity has less effect on the scaling behavior. When the initial surface temperature increases, the inhibition efficiency decreases. In the presence of inhibitors, the scaling behavior is insensitive to the change of surface temperature. The relationship between the inhibition effect and the fractal dimension has also been investigated. The results show that the fractal dimension is higher in the presence of inhibitors. The better the inhibition effect, the higher the fractal dimension. XRD and FTIR analyses demonstrate that for the CaCO(3) formed in the pool boiling system, the content of vaterite increases with the increase of inhibition effects. The metastable crystal forms of vaterite and aragonite are stabilized kinetically in the presence of inhibitors. The step morphology has been observed by atomic force microscopy. It is shown that the step space on the CaCO(3) surface increases in the presence of inhibitors. Moreover, with the increase in inhibition effect, both the step space and the fractal dimension increase. Step bunching is also found and discussed in this paper. Copyright 2001 Academic Press.

Journal Article↗

PubMedDate not supplied

The separation of hypericin's enantiomers and their photophysics in chiral environments.

We report the first separation of the enantiomers of hypericin. Their steady-state optical spectra and ultrafast primary photoprocesses are investigated in chiral environments. Within experimental error, there is no difference between the two enantiomers in any of the systems considered. This is consistent with the emerging picture that the rich and extended absorption spectrum of hypericin is not a result of ground-state heterogeneity. It is also consistent with the observation that the spectra and photophysics of hypericin are generally insensitive to environments in which it does not aggregate.

Anthracenes↗