OBJECTIVETo establish an ELISA approach to study the interaction of polysaccharides with cytokine in vitro.

METHODSThe heparin BSA complexes (HBC) were synthesized with a chemistry method and separated using a 1 X 90 cm column of Separose 4B. After identification of the complex via SDS-PAGE,the wells of ELISA plates were coated with HBC and the interaction of HBC with interferon-gamma (IFN-gamma) was detected. The effects of heparin, low molecular weight heparin (LMW heparin), chondroitin sulfate (CS), hyaluronic acid (HA) and carrageenans on the binding of HBC to IFN-gamma were tested in this system.

RESULTHuman recombinant IFN-gamma bound to heparin in a concentration dependent manner, the binding of IFN-gamma to HBC was detected at the concentration of 0.25 ng, and saturated at around 2 ng. Free heparin, LMW heparin, CS,HA and carrageenans competed for the binding of IFN-gamma to HBC with significant different ability. The IC(50)concentrations of heparin and LMW heparin were 2.40 microg/ml and 18.60 microg/ml respectively.

CONCLUSIONIFN-gamma is a cytokine with high binding affinity to heparin and carrageenans family but poor to CS-A and CS-C. ELISA is a simple, sensitive approach to detect the interaction of polysaccharides with cytokine in vitro.

Enzyme-Linked Immunosorbent Assay ; methods ; Heparin ; metabolism ; Interferon-gamma ; metabolism ; Polysaccharides ; metabolism ; Serum Albumin, Bovine ; metabolism

Animals ; Haptoglobins ; metabolism ; Mesenteric Artery, Superior ; metabolism ; Mesenteric Vascular Occlusion ; blood ; Rabbits ; Serum ; metabolism

OBJECTIVETo explore the mechanism of hypoalbuminemia in patients with severe sepsis.

METHODSI(125)-labeled albumin was administered intravenously to 10 health volunteers and 10 patients with severe sepsis. Blood samples were taken at 0, 1, 2, 4, 8, 12, 24 hours and 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 18, 22, 25 days for the measurement of the dose of gamma-radiation and the curve of concentration and time. Then the half-life time (t(1/2)), apparent volume of distribution (V(d)) and transportation rate (K(12)) from center compartment to side compartment of albumin were calculated.

RESULTSThe half-life time in septic group was obviously shorter than that in control group (8.2 +/- 1.4 vs. 12.5 +/- 1.7, P < 0.01). The transportation rate in the septic group was higher than that in the control group [(4.4 +/- 1.9) x 10(-2)/h vs. (2.4 +/- 0.6) x 10(-2)/h, P < 0.05]. There was no significant difference in apparent volume of distribution between the two groups.

CONCLUSIONSIn patients with severe sepsis, the distribution rate of albumin from vessel to tissue was obviously increased and the decomposition rate of albumin was markedly improved.

Adult ; Aged ; Female ; Half-Life ; Humans ; Kinetics ; Male ; Middle Aged ; Sepsis ; metabolism ; Serum Albumin ; metabolism

OBJECTIVETo establish a direct and fast method separating calcium levofolinate and calcium dextrofolinate in a bovine serum albumin stationary phase chiral column.

METHODSUsing EC150/4 RESOLVOSIL BSA-7(150 mm x 4 mm) chiral separation column, with 0.20 mol/L, pH=5.0 phosphate buffer as mobile phase HPLC method was performed to separate calcium folinate enantiomers.

RESULTThe capacity factor and resolution of the two calcium folinate enantiomers were greatly affected by mobile phase buffer concentration,pH and the column temperature. And the retention time of calcium levofolinate and calcium dextrofolinate were 18.5 min and 22.6 min, respectively. The resolution, R(s)=1.49.

CONCLUSIONCalcium folinate enantiomers are separated successfully using this method.

Chromatography, High Pressure Liquid ; Hydrogen-Ion Concentration ; Leucovorin ; chemistry ; metabolism ; Serum Albumin, Bovine ; metabolism ; Stereoisomerism

OBJECTIVETo study the influence of serum from scalded rats on the cytoskeleton of colonic smooth muscle cells (CSMC) of rats cultured in vitro, and to probe the possible mechanism of gastrointestinal motility disorder after burn.

METHODSCSMC isolated from healthy adult Wistar rat were cultured and divided into scald serum group (SS) and normal serum group (NS) according to the random number talbi. Two normal Wistar rats were used, one of which was inflicted with deep partial-thickness scald. Serum was obtained from blood collected from these two rats respectively and diluted to 20% in concentration. Serum from scald and normal rats were respectively added to the culture of CSMC in SS and NS groups. The expression of actin and the relative content of β-tubulin in CSMC was respectively determined with flow cytometry and Western blot at post treatment hour (PTH) 1, 3, 6, and 12 (with 10 samples in each group at each time point). Data were processed with t test.

RESULTSFluorescence intensity of actin in SS group at PTH 1, 3, 6, and 12 was respectively 59 ± 4, 26 ± 6, 39 ± 6, and 42 ± 6, all significantly lower than those in NS group (95 ± 10, 91 ± 10, 102 ± 9, and 97 ± 9, with t value respectively 10.528, 18.069, 18.748, 16.647, P < 0.05 or P < 0.01). In SS group, the fluorescence intensity decreased to the nadir at PTH 3, and then increased persistently at PTH 6 and 12. (2) Relative content of β-tubulin in SS group at PTH 1, 3, 6, and 12 was respectively 14.44 ± 0.26, 8.61 ± 0.19, 11.76 ± 0.31, and 12.13 ± 0.29, all significantly less than those in NS group (22.37 ± 1.15, 21.87 ± 1.79, 23.24 ± 1.55, and 21.99 ± 2.02, with t value respectively 21.176, 23.365, 23.000, 15.273, P values all below 0.01). In SS group, the relative content of β-tubulin decreased to the nadir at PTH 3 and increased slowly at PTH 6 and 12.

CONCLUSIONSThe reduction of CMSC content which has the tendency of increasing later, can be attributed to the influence of scald serum in initial stage. This may be related to the tolerance and adaptation to scald serum and self-repair of CMSC.

Animals ; Burns ; metabolism ; Cells, Cultured ; Colon ; cytology ; Cytoskeleton ; metabolism ; Male ; Microtubules ; metabolism ; Myocytes, Smooth Muscle ; metabolism ; Rats ; Rats, Wistar ; Serum

Human fibroblast growth factor 21 (hFGF21) has become a candidate drug for regulating blood glucose and lipid metabolism. The poor stability and short half-life of hFGF21 resulted in low target tissue availability, which hampers its clinical application. In this study, the hFGF21 was fused with a recombinant human serum albumin (HSA), and the resulted fusion protein rHSA-hFGF21 was expressed in Pichia pastoris. After codon optimization, the recombinant gene fragment rHSA-hFGF21 was inserted into two different vectors (pPIC9k and pPICZαA) and transformed into three different strains (X33, GS115 and SMD1168), respectively. We investigated the rHSA-hFGF21 expression levels in three different strains and screened an engineered strain X33-pPIC9K-rHSA-hFGF21 with the highest expression level. To improve the production efficiency of rHSA-hFGF21, we optimized the shake flask fermentation conditions, such as the OD value, methanol concentration and induction time. After purification by hollow fiber membrane separation, Blue affinity chromatography and Q ion exchange chromatography, the purity of the rHSA-hFGF21 protein obtained was 98.18%. Compared to hFGF21, the biostabilities of rHSA-hFGF21, including their resistance to temperature and trypsinization were significantly enhanced, and its plasma half-life was extended by about 27.6 times. Moreover, the fusion protein rHSA-hFGF21 at medium and high concentration showed a better ability to promote glucose uptake after 24 h of stimulation in vitro. In vivo animal studies showed that rHSA-hFGF21 exhibited a better long-term hypoglycemic effect than hFGF21 in type 2 diabetic mice. Our results demonstrated a small-scale production of rHSA-hFGF21, which is important for large-scale production and clinical application in the future.
Animals ; Blood Glucose/metabolism* ; Diabetes Mellitus, Experimental ; Fibroblast Growth Factors ; Humans ; Hypoglycemic Agents/metabolism* ; Methanol/metabolism* ; Mice ; Pichia/metabolism* ; Recombinant Fusion Proteins ; Recombinant Proteins/metabolism* ; Saccharomycetales ; Serum Albumin/metabolism* ; Serum Albumin, Human/metabolism*

Aged ; Case-Control Studies ; Humans ; Male ; Malondialdehyde ; metabolism ; Middle Aged ; Oxidation-Reduction ; Serum ; metabolism ; Silicosis ; blood ; Superoxide Dismutase ; metabolism

Animals ; Chickens ; Cold Temperature ; adverse effects ; Gastric Mucosa ; metabolism ; pathology ; physiopathology ; Intestinal Mucosa ; metabolism ; pathology ; physiopathology ; Male ; Serum ; metabolism

AIMTo study the protein binding of glimepiride.

METHODSAn HPLC-FA method is performed by using Pinkerton GFF II-S5-80 internal-surface reversed-phase silica support (150 mm x 4.6 mm ID, 5 microm) at pH 7.4 in a 67 mmol x L(-1) isotonic sodium phosphate buffer at 37 degree C. Other conditions included flow rate of 0.2 mL x min(-1), UV detection at wavelength 230 nm and injection volume 900 microL.

RESULTSNonlinear regression parameter estimation was used for the association constant measurement of glimepiride to both primary and secondary sites, which were 5.1 (micromol x L(-1)-1 and 1 for K1 and n1, and 0.017 (micromol x L(-1))-1 and 7 for K2 and n2, respectively.

CONCLUSIONThe method is shown to be suitable for investigation of protein binding of glimepiride.

Chromatography, High Pressure Liquid ; methods ; Humans ; Hypoglycemic Agents ; metabolism ; Protein Binding ; Serum Albumin ; metabolism ; Sulfonylurea Compounds ; metabolism

Apoptosis ; Cell Line ; Hepacivirus ; genetics ; Humans ; Serum ; metabolism ; Viral Nonstructural Proteins ; genetics