Positive clones from Pichia pastoris strain GS115-47-4 and KM71-47-1 were grown in 1200 ml BMGY/BMMY medium into 2 liters fermentor and 50 ml innoculum with high density was added, temperature was 30oC, agitation speed was 300 rpm and pressure was 0.5 kg/cm2. The biomass was harvested after 72 h of induction in case of GS115-47-4 strain and 48 h for KM71-47-1 strain. The density was 3,9 x 109 cells/ml. After cell lysis, the total HBsAg contents were obtained approximately 30 mg in both strains. 2 consecutive isopycnic KBr gradient ultracentifugations following one rate-zonal sucrose were performed.
hepatitis B vaccines ; isolation & purification ; Hepatitis B Surface Antigens

In order to produce recombinant human anti-HBsAg Fab antibody in Pichia pastoris, the recombinant yeast was fermented using fed-batch system in a 30 L bioreactor. The fermentation temperature was 30 degrees C, the pH was 5.0 approximately 5.3, and the DO was 20% approximately 30%. The recombinant Fab antibody was purified from crude culture supernatant by ion exchange and analyzed by SDS-PAGE and western blot and ELISA. When the absorbance (OD600) of broth reach 300 at the end of fed-batch phase, the induced phase was initiated. The results showed that recombinant human anti-HBsAg Fab antibody was high-level expressed in recombinant Pichia pastoris using a fed-batch fermentation system. Both chains of the Fab were successfully expressed upon methanol induction. After 192 h of induction, the expression level of recombinant Fab (soluble) reached 412 mg/L. The recombinant Fab antibody was purified effectively by ion-exchange chromatography from the fermentation supernatant to a purity of 95%. And the affinity activities of the purified recombinant Fab antibdy and fermentation supernatant were detected, and both of them showed high affinity activities. The results demonstrated that recombinant human anti-HBsAg Fab antibody could be high level produced by fed-batch fermentations in Pichia pastoris. Which can be efficiently used in industrial production.
Fermentation ; Hepatitis B Antibodies ; biosynthesis ; isolation & purification ; Hepatitis B Surface Antigens ; immunology ; Humans ; Immunoglobulin Fab Fragments ; biosynthesis ; isolation & purification ; Pichia ; genetics ; Recombinant Proteins ; biosynthesis ; isolation & purification

OBJECTIVETo investigate the viral contamination of invasive medical instruments in dentistry and to provide health administrative institutions with surveillance data.

METHODSSterilized samples were randomly collected from the department of dentistry to detect HBV-DNA, HCV-RNA, HIV-RNA and HBsAg.

RESULTSOf the invasive medical instruments that were sterilized with 2% glutaraldehyde, one of the samples was positive for HBV-DNA, and another sample was positive for HBsAg.

CONCLUSIONThough massive virus contamination of invasive medical instruments in dentistry has been reduced to a low level, the occurrence of contamination still remains.

DNA, Viral ; analysis ; Dental Instruments ; virology ; Equipment Contamination ; HIV ; isolation & purification ; Hepacivirus ; isolation & purification ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B virus ; isolation & purification ; Humans ; RNA, Viral ; analysis

Three different chemical carcinogens, 2-acetylaminofluorene (AAF), diethylnitrosamine(DENA), and 3'-methyl-4dimethylaminoazobenzene (3'-Me DAB) were used to induce hepatomas in rats. Plasma membrane surface proteins of normal rat liver cells and rat hepatomas were extracted with 3M KCI. From the analysis of the proteins of normal rat liver and rat hepatoma induced by 3'-Me DAB by discontinuous polyacrylamide gel electrophoresis(Disc-PAGE), under nonreducing and nondenaturing conditions polyacrylamide gel electrophoresis in the presence of SDS and 2-mercaptoethanol (SDS-PAGE), Sephadex G-200 gel permeation chromatography, DEAE-A50 ion-exchange chromatography and two-dimensional gel electrophoresis, at least three tumor specific antigens were identified. One had a molecular weigh of 66,000 (pl=6.79) while the other two had the same molecular weight 73,000 but differed in their isoelectric points (7.58 and 7.81). For immunological analysis of tumor specific antigens, the absorbed antiserum was prepared. Plasma membrane surface proteins of rat hepatoma induced by 3'-Me DAB were used to obtain New Zealand White male rabbit antiserum. Rabbit antiserum was then reacted with the proteins isolated from the plasma membrane surface of normal rat liver and the absorbed antiserum reacting specifically with the tumor specific antigens derived by 3'-Me DAB was obtained. Using the absorbed antiserum, the immunoreactivities of plasma membrane surface proteins isolated from rat hepatomas induced by 3'-Me DAB, AAF, and DENA were compared by Ouchterlony double immunodiffusion analysis and immunoelectrophoresis. To characterize the proteins reacting to the absorbed antiserum, immunoglobulin G was separated from the absorbed antiserum and coupled to cyanogen bromide-activated Sepharose CL-4B. The isolated proteins from the plasma membrane surface proteins of 3'-Me DAB-induced hepatoma using this immunoaffinity chromatography had molecular weights of 66,000 and 73,000. The localization of these proteins on surface plasma membranes of rat hepatomas induced by 3'-Me DAB was confirmed by an immunofluorescence technique. The experimental results revealed the existence of cross-reacting common antigens on the plasma membrane surface of rat hepatomas induced by different hepatocarcinogens.
2-Acetylaminofluorene ; Animal ; Antigens, Neoplasm/*isolation and purification ; Antigens, Surface/isolation and purification ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*immunology ; Methyldimethylaminoazobenzene ; Rats ; Rats, Inbred Strains ; Support, Non-U.S. Gov't

In summarizing the results of the experimental studies up to the present, it is conjectured that the pathogenicity of Entamoeba histolytica or establishment of amoebiasis is not unique but differs by strain and age of Entamoeba histolytica and the age of the host. A non-virulent strain is more likely adapt to as low a temperature as 32 . This is not so in the strains which originated form clinical cases. Iso-enzyme patterns may roughly characterize pathogenic strains from non-pathogenic, Red blood cells may contribute as nutrients for growth of Entamoeba histolytica only after they have been hemolysed, but they are toxic to the amoebae as long as they remains intact. A low protein diet and stress may facilitate the establishment of amoebiasis; male sex hormones or previous infection by enteric bacteria provide a more advantageous condition than the female; and hepatotoxic agents will accelerate amoebic hepatitis.
2-Acetylaminofluorene ; Animal ; Antigens, Neoplasm/*isolation and purification ; Antigens, Surface/isolation and purification ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*immunology ; Methyldimethylaminoazobenzene ; Rats ; Rats, Inbred Strains ; Support, Non-U.S. Gov't

Thirty turtles (15 Clemys mutica and 15 Geoclemys reevesii) which were inoculated with human sera those were positive for hepatitis B surface antigen (HBsAg) and hepatitis B "e" antigen (HBeAg) were found to be infected with hepatitis B virus (HBV). The levels of HBV infection markers, such as HBsAg and antibody to HBsAg (anti-HBsAg), were retinely monitored in the turtles' serum for 46 weeks. Within two weeks of the inoculation, 42% of the turtles tested were positive for HBsAg, and their reciprocal titers as measured by reverse passive hemagglutination (RPHA) and enzyme linked immunoabsorbance assay (ELISA) ranged from 16 to 96. Within 20 weeks, the remaining turtles tested HBsAg positive, as confirmed by ELISA. At 20 weeks, all but one of the turtles exhibited changes in HBV blood marker from HBsAg to anti-HBs; the one exception was positive for both HBsAg and anti-HBs. At the 47th week, 7 animals were killed and their organs were examined for HBV infected cells utilizing an immunofluorescent technique. Numerous fluorescent cells which reacted with human anti-HBs nad anti-HBc were observed in the following organs: pancreas, liver, kidney, and brain. Histopathologically, edematous changes in hepatocytes and minor cellular infiltration attributed to an inflammatory response were noted. Liver and kidney cells from the infected animals were cultured, and HBV antigen positive cells for HBsAg and HBcAg were detected in the cultures. Throughout the experiment, HBsAg was detected in the supernatant by ELISA. Virus particles which were indistinguishable from Dane particles were seen in the cytoplasmic vacuoles of the cultured cells by electron microscopy. Finally, the presence of HBV DNA was established by molecular hybridization techniques in the culture supernatants of kidney cells from the infected turtles.
Animal ; Hepatitis B/microbiology/transmission/*veterinary ; Hepatitis B Antibodies/isolation and purification ; Hepatitis B Core Antigens/isolation and purification ; Hepatitis B Surface Antigens/isolation and purification ; Human ; Kidney/microbiology ; Liver/microbiology/pathology ; Turtles/*microbiology

Novel hydrophobic absorbents were synthesized by immobilizing butyl derivative onto the highly cross-linked agarose beads manufatured in China, which are used as matrix. The effect of the spacer arm length (3C, 8C and 10C) and ligand density (from 13 to 45 micromol/mL) on the hydrophobicity were investigated using purified Hepatitis B surface antigen (HBsAg) expressed by CHO cell lines. Also considering the effects of salt concentration and pH on HBsAg recovery and purification factor, orthogonal experiment design method was used to evaluated the absorbents. The results showed the butyl-S absorbent with the spacer arm length of C8, the ligand density of 22 micromol/mL gel showed the best performance for the separation of HBsAg. Approximately 100% HBsAg recovery and 60 as purification fold were achieved by this media under the operating condition of pH 7.0 and 9% of salt concentrateion.
Adsorption ; Animals ; CHO Cells ; Chromatography, Agarose ; methods ; Cricetinae ; Cricetulus ; Hepatitis B Surface Antigens ; biosynthesis ; isolation & purification ; Hydrophobic and Hydrophilic Interactions ; Recombinant Proteins ; biosynthesis ; isolation & purification

The dissociation of virus-like particles of Hepatitis B surface antigen (HBsAg) during the adsorption-desorption on the solid-phase of chromatography is a main challenge for its purification. Herein, poly (ethylene glycol) (PEG) was applied as an additive during the purification of HBsAg from recombinant Chinese hamster ovary (CHO) cell culture to improve the HBsAg recovery and protect its structural assembly. The presence of 1% of PEG10000 in the mobile phase of ion-exchange chromatography (IEC) of DEAE-Sepharose FF column could increase the recovery of HBsAg from about 55% to 80%, with a similar purification (-fold) (about 12) compared with the absence of PEG. Importantly, glycosylated protein forms of HBsAg were reserved well by PEG-accompanied chromatography. Furthermore, size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) analysis was performed on line to monitor the aggregates, particle size and molecular weight distribution of HBsAg. The results demonstrated that the HBsAg particle size and assembly are more homogenous after adding PEG in the mobile phase of IEC than no PEG added in the mobile phase.
Animals ; CHO Cells ; Chromatography, Ion Exchange ; methods ; Cricetinae ; Cricetulus ; Hepatitis B Surface Antigens ; genetics ; isolation & purification ; Humans ; Polyethylene Glycols ; chemistry ; Recombinant Proteins ; genetics ; isolation & purification

A new hydrophobic absorbent based on homemade highly cross-linked agarose beads was synthesized by immobilizing butyl derivative onto the matrix linkage. The density of ligand was controlled by adjusting the concentration of butanethiol and the synthesis route was optimized by evaluating the purification efficiency of recombinant Hepatitis B surface antigen (HBsAg) expressed by Chinese hamster ovary (CHO) cell line. A high performance absorbent was finally screened out with up to 80% of HBsAg recovery and purification-fold (PF) about 20. Furthermore, the column pressure was about 0.06 MPa under the flow rate of 500cm/h, and no leaked butyl were detected after exposing the gel in common buffers, chaotropic agents, high concentrations of denaturing agents such as guanidine hydrochloride, urea and polar organic solvents. These results demonstrated that the absorbent have high physico-chemical stability, so it was available for the downstream process. Finally, after scaled up to 2L wet gel/batch, the absorbent was applied to the integration of three-step chromatography and obtained the purified CHO-HBsAg with 95% purity by SDS-PAGE and HPLC, which meet the requirements of SFDA. The purification efficiency and the reproducible ability of the absorbents were also evaluated from batch-to-batch. The results demonstrated that the absorbent met the requirement of scalable, reproducible, economic effect as well. This absorbent is a promising alternative exported HIC gel for wildly being used in Chinese pharmaceutical industries.
Animals ; CHO Cells ; Chromatography, Agarose ; methods ; Cricetinae ; Cricetulus ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; isolation & purification ; Humans ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification

China ; epidemiology ; Hepatitis B ; classification ; epidemiology ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; genetics ; isolation & purification ; Humans ; Mutation