Cloning and heterologous expression of a hydrophobin gene Ltr. hyd from the tiger milk mushroom Lentinus tuber-regium in yeast-like cells of Tremella fuciformis

Background: Hydrophobins are small proteins secreted by filamentous fungi, which show a highly surface activity. Because of the signally self-assembling abilities and surface activities, hydrophobins were considered as candidates in many aspects, for example, stabilizing foams and emulsions in food products. Lentinus tuber-regium, known as tiger milk mushroom, is both an edible and medicinal sclerotium-producing mushroom. Up to now, the hydrophobins of L. tuber-regium have not been identified. Results: In this paper, a Class I hydrophobin gene, Ltr.hyd, was cloned from L. tuber-regium and expressed in the yeast-like cells of Tremella fuciformis mediated by Agrobacterium tumefaciens. The expression vector pGEH-GH was under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter. The integration of Ltr.hyd into the genome of T. fuciformis was confirmed by PCR, Southern blot, fluorescence observation and quantitative real-time PCR (qRT-PCR). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that recombinant hydrophobin rLtr.HYD with an expected molecular mass of 13 kDa was extracted. The yield of rLtr.HYD was 0.66 mg/g dry weight. The emulsifying activity of rLtr.HYD was better than the typical food emulsifiers sodium caseinate and Tween 20. Conclusions: We evaluated the emulsifying property of hydrophobin Ltr.HYD, which can be potentially used as a food emulsifier.

Effect of Qinbai Qingfei Concentrated pellets on TGF-βand SP-A expression in lung tissue of rats infected by mycoplasmal pneumonia / 中国药理学通报

Aim To discuss the repairing mechanism of Qinbai Qingfei Concentrated pellets to lung tissue of rats infected by mycoplasma. Method 60 Wistar rats weighting 80~100 g, male to female:1 ∶ 1) were di-vided into six groups randomly ( 10 rats in each group): blank group, model group, positive group, the high、middle and low dose groups of Qinbai Qingfei Concentrated pellets. Rats were infected through nasal intubation drip of MP. After 10 days of administration, concentrations of IL-6 , IL-8 AND TNF-α in serum of MPP rats were detected. Left pulmonary tissues of rats were collected to observe the lung tissue pathological change by HE staining and right pulmonary tissues were used to detect the transforming growth factor-beta ( TGF-β) and surface activity related protein A( SP-A) mRNA expression level by real-time quantitative PCR ( RT-PCR) and TGF-βand SP-A protein expression by (Western blot. Result Qinbai Qingfei Concentrated) pellets significantly inhibited inflammation of lung tis-sue, reduced the expression of TGF-β and increased the expression of SP-A in the lung tissue of rats infec-ted by mycoplasma. Conclusion Qinbai Qingfei Con-centrated pellets can inhibit epithelial-mesenchymal transition ( EMT ) , of alveolar type Ⅱ epithelial cells by reducing the content of TGF-β and restore the nor-mal morphology and function of the lung by increasing the expression of SP-A.

Surface activity as basis for pharmaceutical applications of hydrocolloids: A review.

Hydrocolloids are polymeric substances with mild to moderate surface activity. They are widely used as excipients in drug delivery systems where they serve various purposes such as suspending, emulsifying, wetting, foaming, solubilizing, stabilizing and bioadhesive agents as well as permeation enhancers. The surface activity and pharmaceutical applications of some hydrocolloids were reviewed in this study. The review showed that most natural hydrocolloids are characterized by higher critical micelle concentrations (CMC) compared to semisynthetic and synthetic ones. Cashew and khaya gums (exudates gums) with hydrophile – lipophile balance (HLB) values in the range of 15 - 18 possess solubilizing property. Dispersions of afzelia and prosopis gums (seed gums) have higher viscosity compared to acacia gum and may produce more stable disperse systems. Semisynthetic and synthetic hydrocolloids like sodium carboxyl methylcellulose and polyvinylpyrrolidone are characterized by low CMC and exhibit very high surface elasticity at concentrations above CMC thus exhibiting high bioadhesive strength. Therefore, surface activity is the basis for most pharmaceutical applications of hydrocolloids and the application of individual hydrocolloid depends on its adsorption power, CMC, HLB value and bioadhesive strength.

Precalcification Treatment of TiO2 Nanotube on Ti-6Al-4V Alloy / 대한치과보철학회지

STATEMENT OF PROBLEM: Recently precalcification treatment has been studied to shorten the period of the implant. Purpose: This study was performed to evaluate the effect of precalcification treatment of TiO2 Nanotube formed on Ti-6Al-4V Alloy. MATERIAL AND METHODS: Specimens of 20 x 10 x 2 mm in dimensions were polished sequentially from #220 to #1000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at 50 degrees C for 24 hours. The nanotubular layer was processed by electrochemical anodic oxidation in electrolytes containing 0.5 M Na2SO4 and 1.0 wt percent NaF. Anodization was carried out using a regulated DC power supply (Kwangduck FA, Korea) at a potential of 20 V and current density of 30 mA/cm2 for 2 hours. Specimens were heat-treated at 600 degrees C for 2 hours to crystallize the amorphous TiO2 nanotubes, and precalcified by soaking in Na2HPO4 solution for 24 hours and then in saturated Ca(OH)2 solution for 5 hours. To evaluate the bioactivity of the precalcified TiO2 nanotube layer, hydroxyapatite formation was investigated in a Hanks'balanced salts solution with pH 7.4 at 36.5 degrees C for 2 weeks. RESULTS: Vertically oriented amorphous TiO2 nanotubes of diameters 48.0 - 65.0 nm were fabricated by anodizing treatment at 20 V for 2 hours in an 0.5 M Na2SO4 and 1.0 NaF solution. TiO2 nanotubes were composed with strong anatase peak with presence of rutile peak after heat treatment at 600 degrees C. The surface reactivity of TiO2 nanotubes in SBF solution was enhanced by precalcification treatment in 0.5 M Na2HPO4 solution for 24 hours and then in saturated Ca(OH)2 solution for 5 hours. The immersion in Hank's solution for 2 weeks showed that the intensity of TiO2 rutile peak increased but the surface reactivity decreased by heat treatment at 600 degrees C. CONCLUSION: This study shows that the precalcified treatment of TiO2 Nanotube formed on Ti-6Al-4V Alloy enhances the surface reactivity.

ISOLATION OF BOVINE PULMONARY SURFACTANT AND ANALYSIS OF ITS CHEMICAL COMPOSITION AND PHYSICOCHEMICAL PROPERTIES / 第二军医大学学报

Bovine pulmonary surfactant was obtained by endotracheal lavage of lungs from newly slaughtered calves followed by differential centrifugation.Lipid extracts of bovine surfactant contained 86.1?2.1% "of phospholipids (X?SD) , 1.8?1.1%of protein and smaller amounts of cholesterol, fatty acids, glycerides and carbohydrate. Phosphatidylcholine(83.4?5.6%)accounted for most of the phospholipids, of which disaturated phosphatidylcholine was 76.0? 4.7% .The physicochemical properties of bovine surfactant were measured with a modified Wilhelmy film balance made by the authors.The minimum surface tension was 2.4?1.5mN/m, stability index was 1.78?0.15, surface compresibility at 10mN/m was 0.022?0.004 m/mN, and surface concentration of phospholipids at 10mN/m was 1.112?0.283 nmol/cm2. The surfactant spread rapidly and could be quickly absorbed to the surface of the water.The results show that the bovine pulmonary surfactant we isolated is able to meet the criteria for investigations of surfactant replacement therapy.