Protection of Ultra-filtration Extract from Danggui Buxue Decoction(当归补血汤) on Oxidative Damage in Cardiomyocytes of Neonatal Rats and Its Mechanism

Objective： To investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction （当归补血汤, EDBD） was able to protect cardiomyocytes from oxidative injury of rats induced by hydrogen peroxide （H2O2） and its potential mechanism. Methods： Myocardial cells from 1- to 2-day-old neonatal rats were cultured in Dulbecco＇s modified Eagle＇s medium low-glucose and Ham＇s F12 medium （1：1）, and the cellular injury was induced by H2O2. The ultra-filtration extract mixture from Angelica sinensis and Hedysarurn po/ybotrys was given in three doses of 3.75, 7.5, and 15 mg/mL. Morphological changes of cardiomyocytes were observed by microscope. Survival rate of myocardial cells was assessed using 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （Ml-r） assay. The cardiomyocyte damages were estimated by detecting lactate dehydrogenase （LDH） and creatine kinase （CK） releases in the medium, superoxide dismutase （SOD） activities, and intracellular malondialdehyde （MDA） and myeloperoxidase （MPO） contents. The levels of caspase-3 and heat shock protein 70 （hsp70） mRNA expression in cardiomyocytes were measured by reverse transcription polymerase chain reaction. Results： The EDBD could protect the cardiomyocytes from H202 injury in a dose- dependent manner （3.75, 7.50, and 15.00 mg/mL）. The EDBD could significantly decrease LDH and CK leakages and intracellular MDA and MPO contents, increase SOD activity, up-regulate hsp70 expression, and down-regulate caspase-3 expression. Conclusion： The EDBD has protection on cardiomyocytes injured by H202 through improving cell antioxidant ability, up-regulating hsp70 expression, and inhibiting caspase-3 activity.

Efficiency of Advanced Membrane Wastewater Treatment Plant towards Removal of Aspirin, Salicylic Acid, Paracetamol and p-Aminophenol

The efficiency of membrane separation technology for wastewater treatment was employed to check its efficiency in removing pharmaceuticals, their degradation products and their metabolites from wastewater. Aspirin and paracetamol were found to degrade in wastewater furnishing salicylic acid and p-aminophenol, respectively. The kinetics for the degradation reactions of both drugs were investigated in wastewater environment and both have shown first order kinetics with rate constants 0.845 × 10^-8 Ms^-1 and 1.0 × 10^-8 Ms^-1 at room temperature, respectively. These values are an order of magnitude larger than those obtained in pure water under the same conditions. The over all performance of the plant has shown complete removal of these compounds from spiked wastewater within the detection limit of the analytical method. The most effective components for removing those drugs within the plant were activated carbon and clay micelle filters. The adsorption isotherms for these compounds have been studied using both activated carbon and newly developed adsober named clay-micelle complex. All studied isotherms were found to fit Langmuir isotherm. The Langmuir constant and the adsorption capacity were evaluated and discussed.

Influence and mechanism of N-(3-oxooxtanoyl)-L-homoserine lactone(C_8-oxo-HSL) on biofilm behaviors at early stage

N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still sparse. In this study, Pseudomonas aeruginosa biofilm was formed on ultra-filtration membrane under a series of N-（3-0xooxtanoyl）-L-homoserine lactone （C8-0xo-HSL） concentrations. Diffusing Cs-oxo-HSL increased the growth rate of cells on biofilm where the concentration of Cs-oxo-HSL was over 10-7 g/L. The C8-0xo-HSL gradient had no observable influence on cell density and extracellular polymeric substances of biofilm with over 10-7 g/L Cs-oxo-HSL. Surprisingly, 10-11-10-8 g/L of Cs-Oxo-HSL had no effect on cell growth in liquid culture. The cell analysis demonstrated that the quorum sensing system might enhance the growth of neighboring cells in contact with surfaces into biofilm and may influence the structure and organization of biofilm.

Preparation of true solutions of monomeric amyloidogenic protein/peptide:A critical prerequisite for aggregation kinetic study

Our dynamic laser light scattering(LLS) study shows that the current widely used protocols of dissolving amyloidogenic protein/peptide do not really result in a true solution;namely,there always exist a trace amount of interchain aggregates,which greatly affect the association kinetics,partially explaining why different kinetics were reported even for a solution with identical protein and solvent.Recently,using a combination of the conventional dissolution procedure and our newly developed ultra-filtration method,we have developed a novel protocol to prepare a true solution of amyloidogenic protein/peptide without any interchain aggregates.The resultant solutions remain in their monomeric state for at least one week,which is vitally important for further study of the very initial stage of the interchain association under the physiological conditions because more and more evidence suggests that it is those small oligomers rather than large fabric aggregates that are cytotoxic.In addition,this study shows that combining static and dynamic LLS can lead to more physical and microscopic information about the protein association instead of only the size distribution.