Influences of AMY1 gene copy number and protein expression on salivary alpha-amylase activity before and after citric acid stimulation in splenic asthenia children

OBjECTIVE:To compare the correlations between salivary alpha-amylase(sAA) activity and amylase,alpha 1(salivary) gene(AMY1) copy number or its gene expression between splenic asthenia and healthy children,and investigate the reasons of attenuated sAA activity ratio before and after citric acid stimulation in splenic asthenia children.METHODS:Saliva samples from 20 splenic asthenia children and 29 healthy children were collected before and after citric acid stimulation.AMY1 copy number,sAA activity,and total sAA and glycosylated sAA contents were determined,and their correlations were analyzed.RESULTS:Although splenic asthenia and healthy children had no differences in AMY1 copy number,splenic asthenia children had positive correlations between AMY1 copy number and sAA activity before or after citric acid stimulation.Splenic asthenia children had a higher sAA glycosylated proportion ratio and glycosylated sAA content ratio,while their total sAA content ratio and sAA activity ratio were lower compared with healthy children.The glycosylated sAA content ratio was higher than the total sAA content ratio in both groups.Splenic asthenia and healthy children had positive correlations between total sAA or glycosylated sAA content and sAA activity.However,the role played by glycosylated sAA content in sAA activity in healthy children increased after citric acid stimulation,while it decreased in splenic asthenia children.CONCLUSION:Genetic factors like AMY1 copy number variations,and more importantly,sAA glycosylation abnormalities leading to attenuated sAA activity after citric acid stimulation,which were the main reasons of the attenuated sAA activity ratio in splenic asthenia children compared with healthy children.

A robust viscoelastic surfactant tolerating 20% HCl up to 150℃ for oil well stimulation

Viscoelastic surfactants(VES)are often used as viscous diverters in acidizing stimulation to prolong the acid consumption time and maximize zonal coverage of the acid for improving well productivity.However,the ceiling temperature of commercial VES cannot exceed 120℃in practical use because of the poor thermal stability and fragile molecular structure,hindering their implementation in hightemperature oil reservoirs,i.e.,≥150℃.Here we synthesized a novel C22-tailed diamine,N-erucaminopropyl-N,N-dimethylamine(EDPA),and examined comparatively its rheological behavior,assemblies morphology and molecular stability in 20 wt%HCl with a commercial VES,erucyl dimethyl amidopropyl betaine(EDAB).The feasibility of EDPA for acidizing stimulation was assessed by acid etching of carbonate rock with its HCl solution at 150℃.Rheological results showed that the 2.5 wt%EDPA—20 wt%HCl solution maintains stable viscosity of 90 m Pa s at 150℃for 60 min,while that of 2.0 wt%EDAB HCl solution is just 1 m Pa s under identical conditions.1H NMR spectra and cryo-TEM observations revealed that the chemical structure and self-assembled architectures of EDPA remained intact in such context,but the EDAB suffered from degradation due to the hydrolysis of the amide group,accounting for the poor heat-resistance and acid-tolerance.The reaction rate of 2.5 wt%EDPA HCl solution with carbonate rock was one order of magnitude lower than that of 20 wt%HCl solution at 150℃,underpinning the potential of EDPA to be used in the high-temperature reservoirs acidizing.This work improved the thermal tolerance of VES in highly concentrated HCl solution,paving a feasible way for the acidization of high-temperature reservoir environments(~150℃).

Immune Responses to Varicella-Zoster Virus Glycoprotein E Formulated with Poly(Lactic-co-Glycolic Acid) Nanoparticles and Nucleic Acid Adjuvants in Mice

The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy,yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved.Based on poly(lactic-co-glycolic acid)(PLGA)delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion(w/o/w)solvent evaporation method,we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E(VZV-g E)as an antigen and nucleic acids including polyinosinic-polycytidylic acid(Poly I:C)and phosphodiester Cp G oligodeoxynucleotide(Cp G ODN),encapsulated as immune stimulators.While cationic lipids(DOTAP)have more potential than neutral lipids(DOPC)for activating g E-specific cell-mediated immunity(CMI)in immunized mice,especially when g E is encapsulated in and presented on the surface of nanoparticles,PLGA particles without lipids have the greatest potential to induce not only the highest g Especific Ig G titers but also the strongest g E-specific CMI responses,including the highest proportions of interferon-c(IFNc)-and interleukin-2(IL-2)-producing CD4?/CD8?T cells according to a flow cytometry assay and the greatest numbers of IFN-c-and IL-2-producing splenocytes according to an enzyme-linked immunospot(ELISPOT)assay.These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.