Objective In recent years,as people have attached importance to the application of regional chemotherapy in the surgery of advanced gastric cancer,the research of fluorouracil sustained release implant,a regional chemotherapeutic drug,is on the increase.Fluorouracil sustained release implant is a new anti-carcinogen combined with fluorouracil,a conventional chemotherapeutic drug,through polymeric scaffolds and rete technology.It can be implanted into cancerous lesion area,as its slow-releasing potential and targeting property will give full play to the antitumor effect of fluorouracil,which can decrease the rate of local recurrence and metastasis of gastric cancer and prolong the life span of the patients.Based on the study of the researches on fluorouracil sustained release implant,a summary was made from different perspectives: basic medicine,pharmacy and clinical medicine.It may have reference value for clinical application and further study.

The accuracy of preoperative staging diagnosis of colorectal cancer directly determines the accuracy of treatment and prognosis.Endoscopic ultrasonography,CT,MRI and positron emission tomography/computed tomography (PET/CT) imaging have their own advantages and disadvantages in preoperative staging of colorectal cancer.According to the actual situation of patients,choosing the best method of examination,when necessary,several effective methods combined,can improve the accuracy of preoperative staging diagnosis of colorectal cancer.

The aim of this study was to produce E^rns protein of bovine viral diarrhea virus (BVDV) by using suspensively cultured CHO cells expression system and to analyze the immunogenicity of the purified E^rns protein. In this study, the recombinant eukaryotic expression plasmid pcDNA3.1-BVDV-E^rns was constructed based on the gene sequence of BVDV-1 NADL strain. The E^rns protein was secreted and expressed in cells supernatant after transfecting the recombinant expression plasmid pcDNA3.1-BVDV-E^rns into CHO cells. The expression and purification of the E^rns protein was analyzed by SDS-PAGE, the reactivity was determined with anti-His monoclonal antibodies and BVDV positive serum with Western blotting. Immunogenicity analysis of the E^rns protein was determined after immunizing New Zealand white rabbits, and the serum antibodies were tested by indirect ELISA (iELISA) and indirect immunofluorescence (IFA). The serum neutralizing titer of the immunized rabbits was determined by virus neutralization test. The concentration of the purified E^rns protein was up to 0.886 mg/mL by BCA protein quantification kit. The results showed that the E^rns protein could be detected with anti-His monoclonal antibodies and anti-BVDV sera. Serum antibodies could be detected by iELISA on the 7th day post-prime immunization, and the antibody level was maintained at a high titer until the 28th day post-immunization. The antibody titer was 1:128 000. Furthermore, the expression of the E^rns protein in BVDV-infected MDBK cells could be detected with immunized rabbits sera by IFA. Moreover, antigen-specific neutralizing antibodies of 2.71 log₁₀ was induced in rabbits. In this study, purified BVDV E^rns protein was successfully produced using CHO suspension culture system, and the recombinant protein was proved to have a good immunogenicity, which may facilitate the development of BVD diagnosis method and novel subunit vaccine.
Rabbits ; Animals ; Cricetinae ; Cricetulus ; CHO Cells ; Antibodies, Viral ; Diarrhea Viruses, Bovine Viral/genetics* ; Antibodies, Monoclonal/genetics* ; Diarrhea ; Viral Vaccines/genetics*

The aim of this study was to produce recombinant porcine interferon gamma (rPoIFN-γ) by Chinese hamster ovarian (CHO) cells expression system and to analyze its antiviral activity. Firstly, we constructed the recombinant eukaryotic expression plasmid pcDNA3.1-PoIFN-γ and transfected into suspension cultured CHO cells for secretory expression of rPoIFN-γ. The rPoIFN-γ was purified by affinity chromatography and identified with SDS-PAGE and Western blotting. Subsequently, the cytotoxicity of rPoIFN-γ was analyzed by CCK-8 test, and the antiviral activity of rPoIFN-γ was evaluated using standard procedures in VSV/PK-15 (virus/cell) test system. Finally the anti-Seneca virus A (SVA) of rPoIFN-γ activity and the induction of interferon-stimulated genes (ISGs) and cytokines were also analyzed. The results showed that rPoIFN-γ could successfully expressed in the supernatant of CHO cells. CCK-8 assays indicated that rPoIFN-γ did not show cytotoxicity on IBRS-2 cells. The biological activity of rPoIFN-γ was 5.59×10⁷ U/mg in VSV/PK-15 system. Moreover, rPoIFN-γ could induced the expression of ISGs and cytokines, and significantly inhibited the replication of SVA. In conclusion, the high activity of rPoIFN-γ was successfully prepared by CHO cells expression system, which showed strong antiviral activity on SVA. This study may facilitate the investigation of rPoIFN-γ function and the development of novel genetically engineered antiviral drugs.
Swine ; Animals ; Cricetinae ; Interferon-gamma/pharmacology* ; Cricetulus ; CHO Cells ; Sincalide ; Recombinant Proteins/pharmacology* ; Antiviral Agents/pharmacology*