Ethylglucoside lactate, a novel Alpha-Hydroxy Acids Derivative, was synthesized by transesterification in non-aqueous phase using immobilized lipase as biocatalyst. Based on the studies of the factors effecting initial rate and conversion under atmospheric pressure (solvent, acyl donor, different immobilized lipase, substrate concentration, enzyme concentration and temperature), the results show that solvent-free medium using butyllactate as acyl donor is suitable to the ester synthesis. The reaction conditions have been optimized as the following: the amount of enzyme = 75 g/L, the ethylglucoside concentration = 0.4 mol/L, 70 degrees C, 200 r/min, 50 h, which the conversion was 71%. A 90% conversion and a 60.7 mmol.L-1.h-1 initial rate can be obtained under reduced pressure, which the conditions are enzyme 75 g/L, ethylglucoside 0.35 mol/L, 65 degrees C, 200 r/min and 40 h. The product purified by extraction and SIO2 chromatography was identified by infrared spectroscopy and 1H NMR.
Candida ; enzymology ; Enzymes, Immobilized ; metabolism ; Esters ; metabolism ; Glucosides ; isolation & purification ; metabolism ; Kinetics ; Lactates ; isolation & purification ; metabolism ; Lactic Acid ; metabolism ; Lipase ; metabolism ; Substrate Specificity ; Temperature

OBJECTIVETo study the effect of Platycarya strobilacea Sieb. et Zucc (PSZ) extract on methuosis of human nasopharyngeal carcinoma CNE1 and CNE2 cells and explore the underlying mechanism.

METHODSCNE1 and CNE2 cells were treated with 1 mg/mL PSZ extract and the expressions of Rac1 mRNA and Rac1 protein were detected using RT-qPCR and Western blotting, respectively. Results CNE1 and CNE2 cells showed obvious morphological changes typical of methuosis following treatment with PSZ extract characterized by cell merging, accumulation of large cytoplasmic vacuoles, and membrane rupture without obvious changes in the nuclei. PSZ treatment resulted in up-regulated Rac1 mRNA and Rac1 protein expressions in the cells. Application of EHT 1864 obviously blocked the effect of PSZ extract in inducing methuosis in CNE1 and CNE2 cells.

CONCLUSIONPSZ extract can induce methuosis in CNE1 and CNE2 cells by inducing the overexpression of Rac1.

OBJECTIVETo understand the prevalence of Epstein-Barr virus (EBV) infection in urban and rural areas of Beijing using the serological method.

METHODSTotally 589 serum samples were collected from children in Beijing urban and rural areas who were 0--14 years old and tested with Viron-Seron ELISA classic EBV virus capsid antigen IgG antibody (EBV VCA IgG) kit. Optical density of serum samples was obtained at the wavelength of 405 nanometers. Sero-positive or negative samples were determined according to standard curve and cut-off attached in ELISA classic EBV VCA IgG kits. The activity of EBV VCA IgG was calculated by using special formula. The percentage and activity of EBV VCA IgG from Beijing children were compared with SPSS 13.0 between the urban and rural areas.

RESULTSThe percentage of EBV VCA IgG seropositive samples was 83.6%, and 80.8% in those from urban and 86.2% in those from rural areas. The peak value of EBV infection was 71% seen among children under the age of 3 years, and in urban area the rate was 67.7%, which was lower than that in the rural area (75.3%), and was 82.5% by the age of 6, which was lower than the data (up to 90%) reported 30 years ago. There was a significant difference in EBV infection rate and VCA IgG activities in children at different ages between urban and rural areas (P < 0.05).

CONCLUSIONThe rate of EBV infection in children living in urban area was lower by the age of 6 years. The primary infection of EBV occurred late in part of children lived in urban area.

Adolescent ; Age Factors ; Antigens, Viral ; immunology ; Capsid Proteins ; immunology ; Child ; Child, Preschool ; China ; epidemiology ; Cities ; epidemiology ; Epstein-Barr Virus Infections ; epidemiology ; immunology ; Herpesvirus 4, Human ; immunology ; Humans ; Immunoglobulin G ; analysis ; immunology ; Infant ; Infant, Newborn ; Rural Population ; statistics & numerical data ; Serologic Tests