RNA silencing is increasingly employed as an experimental strategy to probe for gene function in several organisms. The purpose of the present study was to test the effect of gene silencing by dsRNA in budding yeast Saccharomyces cerevisiae. GRE3 gene encoding an NADPH-dependent aldose reductase was chosen as an example. A recombinant plasmid psiLENT-GRE3 was constructed based on the pESC-LEU backbone and used to transform S. cerevisiae YPH499. The down regulation of GRE3 gene expression by inducing 1 kb RNA duplex and a 136 bp loop was investigated using reverse transcription- PCR. The results showed that double-stranded RNA mediated gene silencing could be used as a functional tool to decrease the expression level of a specific gene in S. cerevisiae, which would contribute to the understanding of RNA interference in budding yeast.

The contamination of extrinsic harmful contaminants including mycotoxins, heavy metals and pesticides, etc, brings serious risks to traditional Chinese medicines (TCMs), further to human health. Due to their unique photoluminescence, chemiluminescence, electrochemical and electrochemiluminescence properties, semiconductor quantum dots (QDs) nanoparticles are widely used to immobilize bioprobes and biosensors, etc. In this review, the luminescence characteristics and specific ligands of QDs probles which are used to determine contaminants were summed up. Then, the applications of QDs-coated novel probes in the determination of mycotoxins, heavy metals and pesticides were discussed in detail. In addition, the contamination levels and characteristics of extrinsic harmful residues in TCMs were investigated. Further, the maximum levels of those contaminants in TCMs were compared with those set by various countries. Finally, the future development trends and problems of QDs-coated probes in the determination of those extrinsic residues in TCMs were prospected.
Drug Contamination ; prevention & control ; Humans ; Medicine, Chinese Traditional ; methods ; Nanotechnology ; instrumentation ; methods ; Quantum Dots ; Safety ; Time Factors

A simple and cost-effective indirect competitive enzyme-linked immune sorbent assay (ic-ELISA) was developed to rapidly screen the content of aflatoxin B1 (AFB1) in lotus seeds, and the results were confirmed by ultra-fast liquid chromatography-tandem mass spectrometry( UFLC-MS/MS). Matrix-matched calibration expressed a good linearity ranging from 0. 171 to 7. 25 µg · L(-1) for AFB, with R2 > 0.978. The medium inhibitory concentration( IC50 ) for AFB1 was 1.29 µg · L(-1), the recovery for AFB1 was 74.73% to 126.9% with RSD < 5%, and the limit of detection (IC10) was 0.128 µg · L(-1). The developed ic-ELSIA method was applied to rapid analysis of AFB, in 20 lotus seeds samples and the results indicated that the contents of AFB, in samples 1-15 were in the range of 1. 19- 115. 3 µg · kg(-1) and in 40% of the samples exceeded the legal limit(5 µg · kg(-1)), while the contamination rate of AFB, in samples 16-20 was 40%. Pearson correlation coefficient(r) reached 0.997 for AFB1 content in the samples detected by ic-ELSIA and UFLC-MS/MS methods. The results proved that the developed ic-ELISA method is simple, sensitive and reliable, and can be used for rapid and high-throughput screening of AFB1 in lotus seeds
Aflatoxin B1 ; analysis ; Drug Contamination ; Enzyme-Linked Immunosorbent Assay ; methods ; Loteae ; chemistry ; Seeds ; chemistry

With the development of low-carbon economy and renewable resource, fermentation of the pentose sugar xylose to produce ethanol becomes a very hot topic. The recombinant Saccharomyces cerevisiae can be constructed by expressing heterologous xylose isomerase (XI). Because Thermus thermophilus XI (TthXI) does not need cofactor, it has been developed for establishing the utilization pathway of xylose in S. cerevisiae. In this article, we reviewed the progress on xylose isomerase. We first introduced the primary properties, sequence and structure characters of xylose isomerase, and discussed its thermostability. The molecular modification of xylose isomerase, including of substrate specificity and thermostability were discussed in detail. Meanwhile, combined with our own research, we also discussed how to improve the xylose isomerase activity at room temperature. Finally, we suggested perspectives of xylose isomerase.
Aldose-Ketose Isomerases ; chemistry ; genetics ; metabolism ; Catalysis ; Enzyme Stability ; Hot Temperature ; Recombinant Proteins ; biosynthesis ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism ; Substrate Specificity

Objective To assess the application value of high time-resolved MR angiography (TR-MRA) in postoperative follow-up study of children with congenital heart diseases. Methods Seventy-three patients (median age 6 years, range 1-20 years) with congenital heart diseases who underwent TR-MRA scan after operation were retrospectively analyzed. Twenty-nine cases also were performed conventional contrast-enhanced MRA and forty-four cases were performed phase-contrast MRA. A 3D T1-weighted fast gradient-echo sequence was used for time-resolved three-dimensional MRA (10-20 dynamic data sets, less than three seconds per dynamic data set). The flow dynamics and morphology of pulmonary circulations, lung perfusion and collaterals flow direction were noted. All imaging quality was evaluated by using 5 scales. Left and right pulmonary artery flow volumes were measured and left and right pulmonary artery ratio was noted. SPSS22.0 was used in statistic analysis. The statistical analysis of comparing imaging quality was performed by using paired t-test. The intermodality agreement between TR-MRA and phase contrast in assessing left and right pulmonary perfusion was tested by Kappa coefficient. Results In 73 cases, imaging scores were over 3 and imaging quality was good enough for diagnosis. In 29 cases, there was no statistic difference between TR-MRA and conventional CE-MRA in demonstrating great vessels (P>0.05) except that CE-MRA scores(3.77 ± 0.39)was higher than TR-MRA scores(3.44 ± 0.55)of
inferior vena cava (IVC). There was statistic difference(t=3.68,P=0.01)between two sequences. TR-MRA could qualitatively demonstrate the pulmonary perfusion comparing to the results of PC. In PC sequence, there were 8 cases with symmetric and 36 cases with asymmetric left and right pulmonary perfusion. In TR-MRA sequence, there were 6 cases with symmetric and 38 cases with asymmetric left and right pulmonary perfusion. There was an excellent agreement between PC and TR-MRA (Kappa=0.83,P=0.01). Conclusions TR-MRA not only supplies with high spatial resolution imaging which demonstrates postoperative great arteries anatomy and also with high temporal resolution imaging which can demonstrate the preferential or balanced pulmonary blood flow and collaterals flow direction. TR-MRA is a very important sequence in follow-up study of congenital heart disease.

Revolution energy spectral CT had its structural innovation introduced from the aspects of detector,driving system and CT bulb as well as high voltage generator,technical principle analyzed from the aspects of SSF,multi-model iterative reconstruction, cardiac imaging unlimited as well as material separation and quantitative analysis, and clinical application described in diagnoses of liver cancer, cholecystolithiasis and kidney stone, coronary arteriongraphy and metal artifact elimination.It's pointed out Revolution energy spectral CT was a new method for identifying the focal nature,tumor homology and components of inorganic substance as well as analyzing multi material quantitatively and qualitatively.

The chemical constituents were isolated and purified by various chromatographic techniques indluding silica gel, reverse phase silica gel, sephadex LH-20 and pre-HPLC and identified by their physicochemical properties and spectral data. Sixteen phenolic compounds had been isolated and n-butanol extracts which were fractionated from the ethanol extract of Oplopanax horridus roots bark. Their structures were identified as below, including 7 phenylpropanoid compounds, ferulic acid (1), 3-acetylcaffeic acid (2), caffeic acid (3), homovanillyl alcohol 4-O-beta-D-glucopyranoside (4), 3-hydroxyphenethyl alcohol 4-O-beta-D-glucopyranoside (5), 3, 5-dimethoxycinnamyl alcohol 4-O-beta-D-glucopyranoside (6), and 3-dimethoxycinnamyl alcohol 4-O-beta-D-glucopyranoside (7). Three coumarins, scopoletin (8), esculetin (9) and 3'-angeloyl-4'-acetyl-cis-knellactone (10). And 6 lignan compounds, (+)-isolaricires-inol-9'-O-beta-D-glucopyranoside (11), 3, 3'-dimethoxy-4, 9, 9'-trihydroxy-4', 7-epoxy-5', 8-lignan-4, 9-bis-O-beta-D-glucopyranoside (12), (+)-5, 5'-dimethoxylariciresinol 4'-O-beta-D-glucopyranoside (13), (-)-5,5'-dimethoxylariciresinol 4'-O-beta-D-glucopyranoside (14), (-)-pinoresinol 4'-O-beta-D-glucopyranoside (15), and (+)-5, 5'-dimethoxylariciresinol 9'-O-beta-D-glucopyranoside (16). All compounds were isolated and identified for the first time from this plant All the constituents except compounds 4, 6, 12 and 13 were obtained for the first time from the genus Oplopanax.
Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Oplopanax ; chemistry ; Phenols ; chemistry ; isolation & purification ; Spectrometry, Mass, Electrospray Ionization

Acetaldehyde ; pharmacology ; Animals ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; Flavonoids ; pharmacology ; Hepatocytes ; cytology ; physiology ; Rats

OBJECTIVETo investigate the clinical pathology of cavernous venous malformations of the body surface.

METHODSTissue samples of cavernous venous malformations from 42 cases were stained with hematoxylin and eosin to observe the pathologic structure. The clinical manifestations and case history were summarized accordingly.

RESULTSThere was no distribution difference of the malformation in sex and body sides, but with obvious difference in anatomic sites. The malformation occurred most frequently at the head and neck, more frequently at extremities and least frequently at the trunk. According to pathologic structure, cavernous venous malformations of the body surface can be divided into three types: the cellular, the canaliform and the mixed.

CONCLUSIONThe cause of distribution difference in anatomic sites remains unclear. Internal hemorrhage and infection may account for the increased growth and ache of the lesion. The different pathologic structure of the malformation may cause different clinical manifestations.

Adolescent ; Adult ; Aged ; Arteriovenous Malformations ; complications ; pathology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Infection ; etiology ; Male ; Middle Aged ; Pain ; etiology ; Sex Factors ; Skin ; blood supply ; pathology ; Veins ; abnormalities

The argE gene from Escherichia coli coding for N-acety-L-ornithine deacetylase(NAOase), the key enzyme involved in the L-arginine biosynthesis, had been cloned in pET22b and transformed into BL21 (DE3). With 32.5% expression level in the optimal fermentation medium at 37 degrees C, most NAOase was expressed as inclusion bodies. The soluble and active proportion could be slightly increased when expressed at low temperature. The specific activity of soluble NAOase purified by Ni-NTA resin chromatography was 1193.2u/mg. The species and proportions of whole cell proteins varied with induction conditions. The inclusion bodies expressed at 37 degrees C was more pure than 22 degrees C after gradient wash with urea. Inclusion bodies could be partly refolding and reactivated by dilution and dialysis. Low protein concentration and suitable rate of oxidant/reducing agents were important to renaturation. In the optimal conditions 17.78% of Urea-denatured NAOase could be refolding and reactivated by dilution. The purified fusion protein was obtained after wash, solubilization and Ni-NTA resin affinity chromatography purification of inclusion bodies.
Amidohydrolases ; chemistry ; genetics ; metabolism ; Biocatalysis ; drug effects ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; enzymology ; genetics ; Escherichia coli Proteins ; genetics ; metabolism ; Gene Expression Regulation, Bacterial ; Gene Expression Regulation, Enzymologic ; Inclusion Bodies ; enzymology ; Protein Folding ; drug effects ; Recombinant Proteins ; chemistry ; isolation & purification ; metabolism ; Urea ; pharmacology