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Biomedical subjects

Jun-zhi Wang

Publications and source records attributed to Jun-zhi Wang.

9 recordsLinked to original sources
PubMed2006

[The clinical study of circumferential ablation around orifice of pulmonary vein by radiofrequency energy with chronic atrial fibrillation undergoing rheumatic valvular heart surgery].

OBJECTIVE: To evaluate the clinical efficiency of circumferential ablation around orifice of pulmonary vein by radiofrequency (RF) energy in the cure of chronic atrial fibrillation (AF) in patients with rheumatic valvular disease. METHODS: Radiofrequency catheter ablation was performed in 20 patients with rheumatic valvular disease and chronic AF who underwent heart valve surgery. The ablation temperature was 50 - 60 degrees C and the linear RF ablations were performed encircling the four openings of pulmonary veins and connecting the posterior mitral annulus with the probe made by ourselves especially for this ablative procedure. And amiodarone was given from the third day before the surgery and lasted for 3 months thereafter. Twenty patients with chronic AF who underwent valvular surgery but refused RF ablation were considered as the control group. RESULTS: Sinus rhythm (SR) restored in 19 patients either spontaneously or after intraoperative direct current cardioversion, immediately after the operation, as compared with 16 patients in the control group. During the follow-up (24 +/- 3) months, 16 of 20 patients (80%) remained in sinus rhythm in patients received ablation, but in control group, SR was presented in only 7 of 20 patients (35%). CONCLUSIONS: Circumferential ablation around orifice of pulmonary vein by RF energy is safe and effective in restoration and maintenance of SR in patients with rheumatic valvular disease and chronic AF.

Adult↗
PubMed2006

[Peptide mapping analysis of recombinant human interleukin-11 with HPLC-ESI-Q-TOF/MS spectrometry].

AIM: To analyze the peptide mapping of recombinant human interleukin-11 (rhIL-11) by HPLC-ESI-Q-TOF/MS spectrometry. METHODS: The trypsin digested rhIL-11 at 37 degrees C over night, and the peptide mapping was performed by HPLC. The relative molecular weight of the peptides fragments was measured by ESI-Q-TOF/MS, and amino acid sequence was analyzed by MS/MS. RESULTS: The peptide fragments of rhIL-11 in the peptide mapping were assigned by analyzing the retain time, relative molecular weight and amino acid sequence. And 97% of the expected peptides were detected in this way. CONCLUSION: The study proves that HPLC-ESI-Q-TOF/MS is a good method to analyze peptide mapping of protein with the advantage of sensitivity, high speed and accuracy.

Amino Acid Sequence↗
PubMed2004

[Study on methods for quality control of recombinant human neu epitope peptide 12].

AIM: To establish methods and requirements for the quality control of recombinant human neu epitope peptide 12. METHODS: Biological activity of recombinant human neu epitope peptide 12 was evaluated in FVB/N transgenic mice (TgN MMTV neu 202 Mul, Jackson Lab., USA) administered with samples. The percentage of antibody-positive mice detected by ELISA was used in the biological activity evaluation. The peptide map was performed by peptic digestion. The antigen content was determined by SEC-HPLC. RESULTS AND CONCLUSION: The quality control methods, such as biological activity, peptide map, antigen content, and the requirements for the quality control of recombinant human neu epitope peptide 12 were established. The established methods and requirements were already used for the quality control of recombinant human neu epitope peptide 12 products.

Animals↗
PubMed2004

Expression of human nerve growth factor beta gene in central nervous system mediated by recombinant adeno-associated viruses type-2 vector.

BACKGROUND: Neurone atrophy and loss are major causes of chronic neurodegenerative disorders such as Alzheimer's disease. Despite many pharmacotherapies for neurodegeneration, there are no accepted treatments. We investigated the feasibility of human nerve growth factor beta (hNGFbeta) gene expression mediated by recombinant adeno-associated viruses type-2 (rAAV-2) vector in the central nervous system (CNS) after blood brain barrier (BBB) disruption. METHODS: rAAV-2 containing hNGFbeta gene was constructed. The ability of hNGFbeta gene mediated by rAAV-2 vector (rAAV-2/hNGFbeta) to transfect cells in vitro was confirmed by both ELISA and bioassay of hNGFbeta in the culture supernatant of BHK-21 cells infected by rAAV-2/hNGFbeta. rAAV-2/hNGFbeta and rAAV-2/green fluorescence protein (GFP) were administrated separately to rat brains through internal carotid intubation after BBB disruption with hypertonic mannitol. Brain hNGFbeta concentration was measured by ELISA and GFP in brain sections was examined by laser scan confocal microscope. RESULTS: After 48 hours, hNGFbeta content in supernatant was up to (188.0 +/- 28.6) pg/ml when BHK-21 cells were infected by rAAV-2/hNGFbeta at multiplicity of infection (MOI) 1.0 x 10(6) vector genome. Neurone fibre outgrowths were obvious in dorsal root ganglion neurone assays by adding serum free culture medium harvested from BHK-21 cells exposed to rAAV-2/hNGFbeta. Whole brain hNGFbeta content in rAAV-2/hNGFbeta transferred group was up to (636.2 +/- 140.6) pg/ml. hNGFbeta content of BBB disruption in rAAV-2/hNGFbeta infused group increased significantly compared to the control group (P <0.05). GFP expression was clearly observed in brain sections of rAAV-2/GFP transferred group. CONCLUSION: rAAV-2/hNGFbeta successfully expresses in the CNS after BBB disruption induced by hypertonic mannitol.

Animals↗
PubMed2003

[Study on methods and requirements for quality control of recombinant human tumor necrosis factor receptor Fc fusion protein].

AIM: To establish methods and requirements for quality control of recombinant human tumor necrosis factor receptor Fc fusion protein (rhTNFR-Fc). METHODS: Biological potency of rhTNFR-Fc was determined by neutralizing the bioactivity of TNF-alpha. rhTNFR-Fc samples were reduced by beta-mercaptoethanol and the peptide map was performed by tryptic digestion. Residual protein A and the host cell protein content were detected by ELISA. Anti-TNFR and anti-Fc antibodies were used in ELISA for detection of the rhTNFR-Fc content. RESULTS: The quality control methods, such as bioassay, peptide map, residual protein A detection, were established and used for quality control of rhTNFR-Fc. The unit of rhTNFR-Fc (AU) was defined according to the international unit of TNF-alpha. The specific activity was up to 8 x 10(4) AU.mg-1. The requirements for quality control of rhTNFR-Fc were established. CONCLUSION: The methods and requirement were used for quality control of rhTNFR-Fc products.

Animals↗
PubMed2003

[Quality control of recombinant adeno-associated virus type 2/human blood coagulation factor IX].

AIM: To establish quality control requirements and methods for recombinant adeno-associated virus(rAAV) type 2/human blood coagulation factor IX (rAAV-2/hFIX). METHODS: Identification of rAAV genome fragments, potential contaminants including wild type AAV(wtAAV) and helper virus, were detected by PCR. Purity of rAAV-2/hFIX was analyzed by cation-exchange HPLC and SDS-PAGE. Virus partical numbers were performed by dot blot assay. hFIX expression was demonstrated by ELISA and potency of hFIX was verified by APTT. RESULTS: Identity of rAAV-2/hFIX was proved. Residues of wtAAV and helper virus were conformed to requirements. Purity of rAAV-2/hFIX were more than 98%. Partical numbers of rAAV-2/hFIX were more than 1.0 x 10(15) VG.L-1. hFIX expression was more than 20.0 micrograms.L-1. hFIX potency was verified by APTT following rAAV-2/hFIX injected to FIX gene knockout mice, potency results conformed to requirements. CONCLUSION: The methods and requirements had been established for quality control of rAAV-2/hFIX.

Animals↗
PubMed2002

[Quality control for recombinant adenovirus-IL2].

AIM: To investigate the quality and optimized test methods and establish the quality specification of recombinant adenovirus-IL2. METHODS: The titer of Adv-IL2 was measured by cytopathic effect (CPE). Hela cells were infected with Adv-IL2 in vitro, the expressed IL-2 and its bioactivity in Hela cell were determined by enzyme-linked immunosorbent assay (ELISA) and 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) respectively. The purity of Adv-IL2 was analysed by UV and IE-HPLC method. The molecular weight and enzyme digestive map of Adv-IL2 genome were analysed by electrophoresis. The characteristic gene E2B, IL-2 expression casseter and foreign factors (RCV, HIV, HBV, HCV) were detected with polymerase chain reaction (PCR). Other tests were carried out according to the Chinese Requirements for Biological Products. RESULTS: Adv-IL2 was generated efficiently with a titer of 3 x 10(10) pfu.mL-1. The expressed IL-2 and its bioactivity were 25 ng.mL-1 and 700 u.mL-1 respectively. A260 nm/A280 nm was 1.23. The purity determined by IE-HPLC was higher than 98%. The molecular weight, enzyme digestive map of Adv-IL2 genome, the characteristic gene E2B and IL-2 expression casseter conformed to expected values. CONCLUSION: The specification for Adv-IL2 is established and can be used for the quality control of the product.

Adenoviridae↗
PubMed2002

[Quality control methods for recombinant human endostatin].

AIM: To establish the quality control methods for recombinant human endostatin. METHODS: Biological activity was determined by endothelial cell migration assays. Peptide mapping was tested by trypsin digestion and RP-HPLC. Purity was determined by non-reduced SDS-PAGE and RP-HPLC. Other tests including molecular weight, isoelectrical point, etc. were done according to the National Requirements for Biological Products (2000). RESULTS: The method of bioassay was established and used for determining activity of endostatin. Specific activity of the three batchs of drug substance was 1.45 x 10(6), 1.57 x 10(6) and 2.73 x 10(6) u.mg-1 proteins. Peptide mappings of the three batches of drug substance were completely identified. Both purity results of the products tested by SDS-PAGE and RP-HPLC were more than 99%. CONCLUSION: The established methods can effectively control the quality of recombinant human endostatin.

Cell Movement↗