The technique of double-layered plate was developed for screening the library of mutant endoglucanase III from Trichoderma reesei generated by the method of directed evolution.The enzyme activity was determined according to the velocity of the formation of halos on the plates.Several mutants with higher activity than the wild type at low temperature or alkaline pH were obtained by using this strategy under different screening conditions.Further results of spectrophotometric determination of the activities of these mutants were consistent with the results of plate screening.The establishment of such strategy will broaden the applications of the directed evolution methods for improving the existing proteins to obtain useful enzymes with new properties for industrial applications.

AIMTo study the interaction mechanism of bovine serum albumin (BSA) with luteolin and apigenin.

METHODSFluorescence quenching method and non-radioactive energy transfer theory were used.

RESULTSThe binding constants at different temperature were determined and the quenching mechanism of them were suggested as static quenching. The transfer efficiency of energy and distance between BSA and luteolin or apigenin were investigated according to the mechanism of the Förster energy transference.

CONCLUSIONThe interaction between them seems to be strong and the binding force were mainly hydrophobic force. B(3')-OH,B(4')-OH strengthened the interaction of flavonoids and BSA.

Apigenin ; chemistry ; Energy Transfer ; Luteolin ; chemistry ; Protein Binding ; Serum Albumin, Bovine ; chemistry ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Thermodynamics

Pathway engineering was the third generation of gene engineering. Its main goals were to change metabolic flux and open a new metabolic pathway in organism. Application of recombinant DNA methods to restructure metabolic networks can improve production of metabolite and protein products by altering pathway distributions and rates. Ethanol is the most advanced liquid fuel because it is environmentally friendly. Enhancing fuel ethanol production will require developing lower-cost feedstock, and only lignocellulosic feedstock is available in sufficient quantities to substitute for corn starch. Xylose is the major pentose found in lignocellulosic materials and after glucose the most abundant sugar available in nature. Recently a lot of attentions have been focused on designing metabolic pathway of Saccharomyces cerevisiae in order to expand the substrate of ethanol fermentation, because it is a traditional ethanol producing strain and has wonderful properties for ethanol industry. However, it can not utilize xylose but convert the isomer, xylulose. Many attempts are based on introducing the genes in the pathway of xylose metabolism. The further research includes overexpressing the key enzyme or decreasing the unimportant flux. The sugars in lignocellulose hydrolyzates, therefore, could be efficiently utilized. Here, we describe the ethanol pathway engineering progress in ethanol fermentation from xylose with recombinant Saccharomyces cerevisiae.
Biotechnology ; methods ; Ethanol ; metabolism ; Fermentation ; genetics ; physiology ; Recombination, Genetic ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism ; Xylose ; metabolism

Abstract: Objective　This paper aims to explore the effect of live attenuated varicella vaccine on the sensitivity of tuberculin skin test(TST), and to provide reference for tuberculin skin test in the future. Methods　TST and emergency varicella vaccine were administered to students in grade one of a high school in Wuxi, Jiangsu province, who had both TB and varicella cases. Independent-samples t test was used to analyze the mean diameter of induration of TST in day 0, day 83 and day 195. The retrospective cohort study was used to analyze the effect of live attenuated varicella vaccine on TST. 　　Results　The mean induration diameter of 45 students who participated in three TST tests on day 0, day 83 and day 195 were analyzed by independent sample t test. On day 0, there was a difference in the mean diameter of TST induration between the unvaccinated and vaccinated groups(1.630±2.837 vs 5.818±4.530) (t=-3.692, P=0.001). On day 83, there was no difference in the mean diameter of TST induration between the two groups(0.001±0.001 vs 0.114±0.533) (t=-1.000, P=0.329). On day 195, there was a difference in the mean diameter of TST induration between the two groups(1.913±3.774 vs 5.023±5.126) (t=-2.309, P=0.026). Moreover, the retrospective cohort study showed that the mean diameter of TST induration changed more significantly after inoculation with varicella vaccine, RR=6.071, 95%CI (1.667-22.116), P<0.05; After inoculation with varicella vaccine, the mean diameter of TST test did not change significantly from day 0 to day 195 with no statistical significance RR=3.474, 95%CI (0.333-36.240), P>0.05. Conclusions　Live attenuated varicella vaccine may temporarily affect the sensitivity of tuberculin skin test.

OBJECTIVETo establish a method suitable to determine the purgative biopotency of rhubarb and construct a new quality evaluation pattern of rhubarb.

METHODA series of factors such as observation index (mass of feces in 10 hours), animal strain (ICR mice), sex (male) and the dose of diphenoxylate complex (50 mg x kg(-1)) was investigated and fixed. The purgative biopotency as well as anthraquinone determination was used to evaluate the quality of different rhubarb samples.

RESULTThere wasn't a good linear relationship between the purgative biopotency and content of anthraquinone. The quality difference of rhubarb samples could be well characterized by combination of purgative biopotency determination and anthraquinone determination.

CONCLUSIONThe purgative biopotency determination can be used in quality control and evaluation of rhubarb.

Animals ; Anthraquinones ; analysis ; Biological Assay ; Cathartics ; pharmacology ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Linear Models ; Male ; Mice ; Quality Control ; Reproducibility of Results ; Rheum ; chemistry ; Sex Factors ; Time Factors

The essential issues of bioassay methods for quality control of traditional Chinese medicines (TCM) were investigated and discussed through the instantiation of developing the bioassay methods for laxative drugs. For the relatively broad variation of the quality of TCM, which might be influenced much by many factors, the parallel lines model of quantitative response is preferred to control the quality of TCM for its relatively high accuracy. The parallel model of quantal response is alternative while the sample can not meet the reliability standard for quantitative response model. According to the requirement of homogeneity between reference and sample for bioassay, the extract from referenced crude meterial is suitable to be used as reference substance after standardizing and defining by chemical substances, and to give reference to the establishment and reproducibility of authorized standard substance. The results of determination of the purgative biopotency of different species of rhubarb and the compound preparations showed that the bioassay methods and self-made reference substance established in this study could be used to control the quality of laxative medicines.
Animals ; Anthraquinones ; isolation & purification ; pharmacology ; Biological Assay ; methods ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Laxatives ; isolation & purification ; pharmacology ; Linear Models ; Male ; Medicine, Chinese Traditional ; Mice ; Quality Control ; Random Allocation ; Rheum ; chemistry

OBJECTIVETo investigate the relationship between the laxative potency and anthraquinones content of six kinds of traditional Chinese drugs (TCDs) like Rheum tanguticum, Polygonum cuspidatum, R. palmatum, R. officeinale, Semen Cassiae and Radix Polygoni Multiflori.

METHODThe half effective dose (ED50) was applied to determine the laxative potency and the content of anthraquinones was evaluated by RP-HPLC.

RESULTThe ED50 for the six kinds of TCD was 0.458, 0.686, 0.925, 1.004, 1.047, 1.986 g x kg(-1), respectively, and the sequence of laxative potency was R. tanguticum > P. cuspidatum > R. palmatum > R. officeinale > Semen Cassiae > Radix Polygoni Multiflori. In terms of the HPLC quantitative determination, the content of combined anthraquinones was 2.82% ,1.64%, 1.44%, 0.82%, 0.15%, 0.019%, respectively,and the sequence was R. tanguticum > Polygoni cuspidatum > R. palmatum > P. cuspidatum > Semen Cassiae > Radix Polygoni Multiflori.

CONCLUSIONThere is a great difference in laxative potency between TCDs, and the relationship between laxative potency and the content of combined anthraquinones was found. The bioassay may be utilized to evaluate and control the quality of TCD with the chemical methods.

Animals ; Anthraquinones ; analysis ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Laxatives ; chemistry ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Regression Analysis

OBJECTIVETo observe protective effects of Shenmai (SM) injection on the delayed injury of the cerebral neurons in rat with intracerebral hemorrhage.

METHODRosenberg models of intracerebral hemorrhage was established and the effects of SM injection on the pathologic changes in neuronal structure, mitochondria-DNA(mtDNA)deletion, C-myc gene and expression PDGF-A gene in hippocampal CA1 areas, were investigated.

RESULTSM injection inhibited the apoptosis of pyramidal cells in the hippocampal CA1 areas, and decreased the degree of mtDNA deletion in the neurons in the injured area. SM injection had no effect on gene expression of C-myc at initial stage a intracerebral hemorrhage, but significantiy decreased the level of PDGF-A mRNA and prolonged the time of its expression.

CONCLUSIONSM injection might attenuate the delayed injury induced by intracerebral hemorrhage via regulating the expression of PDGF.

Animals ; Apoptosis ; drug effects ; Cerebral Hemorrhage ; metabolism ; pathology ; DNA, Mitochondrial ; genetics ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Gene Deletion ; Hippocampus ; pathology ; Male ; Neurons ; drug effects ; Neuroprotective Agents ; administration & dosage ; pharmacology ; Ophiopogon ; chemistry ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; Platelet-Derived Growth Factor ; biosynthesis ; genetics ; Pyramidal Cells ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley

15 scores were randomly divided into therapeutic group (30 cases)and control group(30 cases).The two groups were treated with the same conventional therapy. From the 1st day of admission,Xuebijing injection 80 ml was given by intravenous drip once for every 12 hours for 7 days to the therapeutic group.The level of tumor necrosis factor-?(TNF-?),interleukin-1?(IL-1?),IL-6,IL-10,and APACHEⅡscore were tested on 1,3,5 and 7 days after admission.The case fatality and incidences rates of sepsis and MODS in both groups were recorded.Results Compared with the control group,APACHEⅡscore,TNF-?,IL-1?,IL-6 and IL-10 of the therapeutic group were lower significantly on the 3rd day after admission,especially on the 5th day(all P

[Objective] To investigate the awareness rate of AIDS and STDs related knowledge, the epidemic features of high-risk behaviors and related risk factors among pregnant women in a sentinel hospital of Liangxi District of Wuxi City. [Methods]The pregnant women who built health care manual or accepted pregnancy health care from April to June in every year during 2010-2015 were investigated.[Results]Of more than 2 400 pregnant women investigated, the infection rates of HIV, syphilis, and HCV were 0.04％, 0.46％ and 0.25％. The awareness rate of knowledge was 85.79％. But, the understanding of AIDS was not scientific and comprehensive. [Conclusion]The infection rates of HIV and other STDs were observed at low levels among pregnant women in the sentinel hospital of Liangxi District. But, some still had high-risk behaviors. The mastery degree of the knowledge of AIDS prevention and control were not comprehensive. Policy advocacy, health education, voluntary consultation test and many other prevention and control strategies must extend the coverage from high risk groups to pregnant women and many other general population. Intensive education about AIDS should be carried out to help people have a correct and scientific understanding of AIDS.