An Lijia

Effect of Cuscuta chinensis glycoside on the neuronal differentiation of rat pheochromocytoma PC12 cells

Exposure of rat pheochromocytoma PC12 cells to Cuscuta chinensis glycoside induced neuronal differentiation with resulting outgrowth of neurites and increase of acetylcholinesterase activity. A specific inhibitor of mitogen‐activated protein kinase (MAPK) kinase, PD98059, prevented this effect of C. chinensis on PC12 cells. These results suggested that C. chinensis glycoside induced neuronal differentiation in PC12 cells linked to the mitogen‐activated protein kinase signaling cascade.

Extraction and Purification of Anthocyanins from the Fruit Residues of Vaccinium uliginosum Linn

An aqueous two-phase system was developed to extract anthocyanins present in the fruit residue during juice production from the fruit of Vaccinium uliginosum Linn. A maximum partition coefficient of 10.67 and a recovery of 96.09% for anthocyanins could be obtained using an extraction system consisted of 30% (w/w) ethanol and 19% ammonium sulfate. Compared with the traditional extraction using acidified ethanol, the novel aqueous two-phase extraction could not only yield a much higher concentration of anthocyanins, save more ethanol, energy, and time, but also decrease impurities in extract, e.g. proteins and sugars by 58% and 66%, respectively. AB-8 macroporous resin was applied to the purification of anthocyanins. A novel and simple separation technique for anthocyanins was developed by integrating aqueous two-phase extraction and macroporous resin column chromatography. This new technology might be a suitable for other bioactive natural products on industrial scale.

An expeditious method for constructing T-vectors usingEam 1105 I cassettes

An expeditious method is described for constructing T-vectors containing complementary 3′-thymidine overhangs. A T-vector was developed by cloning a 90-bpEam 1105 I cassette containing 2Eam 1105 I restriction sites into a modified pUC119 vector. TheEam 1105 I cassette was generated by PCR with 2 specific primers containing different recognition sequences ofEam 1105 I. The recombinant vector was easily converted into a T-vector by digestion of the plasmid withEam 1105 I. The cloning efficiency of the PCR product was approximately 90%. The method described here is a simple way to construct a variety of T-vectors.

Production of a functional single-chain Fv protein in transgenic tobacco root exudates

Nicotiana tabacum was transformed with a gene encoding anti-PreS1 of hepatitis B surface antigen single-chain Fv antibody (scFv) and bearing an N-terminal endoplasmic reticulum protein signal peptide sequence. The scFv antibody protein was continuously secreted from the transgenic tobacco roots into a simple hydroponic medium at 630 to 760 ng g−1 dry wt root day−1. The antibody was about 2% of the total secreted protein and still possessed antigen-binding activity.

A new way for chemical degradation of plastic by natural volatile constituents of Ledum palustre

A novel phenomenon of degradation of polypropylene plastic by volatile constituents of Ledum palustre is reported in this study. The characteristic of degradation is described by tensile strength, melting point, and scanning electron micrographs as well as optical micrographs. The chemical composition of volatile oil of Ledum palustre is analyzed by gas chrography and mass spectrometry. The mechanism of degradation and problems needed to be solved are also discussed.

Myotoxic activity of a Gln-49 phospholipase A2 from Agkistrodon blomhoffii ussurensis snake venom

Abstract A novel myotoxic protein phospholipase A2 (PLA2), denoted as Gln49-PLA2, denoted as Gln49-PLA2, has been isolated from snake venom of Agkistrodon blomhoffii ussurensis, which has weak lethal effect and apparent anticoagulant activity, but lacks the PLA2 and hemorrhagenic activity. Gln49-PLA2 obviously increases of plasma creatine-kinase (CK) upon intramuscular injection in mice, suggesting that it may induce a dose-dependent myonecrosis. Histological studies also reveal morphological changes in mouse skeletal muscles, including extensive myonecrosis, hemorrhage and neutrophil infiltration in the treated animals. The myotoxic ability induced by Gln49-PLA2 can be partially inhibited by heparin. * Supported by Dalian Science and Technology Bureau