Microbial lipases have been widely used in traditional industries,as well as in emerging biocatalysed areas owing to their ability to catalyze a variety of reactions in aqueous and non-aqueous media.Therefore,it is very important to enhance amount of lipase production by recombinant overexpression for meeting market demand.A critical review of main and novel strategies which have been employed for recombinant expression of microbial lipases are presented,including codon optimization,fusion and co-expression,dual expression system based on hybrid promoters,homologous overexpression,cell surface displaying and high-throughput screening based on gene library of expression.These new technologies are gradually coming to the forefront in the recombinant expression of lipase,especially for cell surface displaying and high-throughput screening based on gene library of expression.Meanwhile,several recombinant expressions for representative microbial lipases were also introduced and discussed,which are available for consultation when attempting to overexpress any lipases by scientists and industrialists.

Purpose:To study the effect of inhibition of telomerase activity and cell cycle by transcriptase telomerase inhibitors (3′ azido 3′ deoxythymidine, AZT) on squamous cell carcinoma of tongue in vitro.Methods:Human squmous cell carcinoma of tongue cell line Tca8113 was used as target cell. Telomerase activity was determined by TRAP PCR ELISA in untreated and treated Tca8113 by AZT, cell cycle phases were analyzed by flow cytometry. Results:Telomerase activity of Tca8113 was significantly inhibited when treated with AZT, and the effect of inhibition was dose dependant (rate of telomerase activity treated with AZT in 0.3, 0.6, 1.0, 1.5mol 10 -1 was 0.69 0.03, 0.61 0.08, 0.53 0.11, 0.50 0.02 respectively, rate of telomerase activity treated without AZT was 0.76 0.06). Cell cycle of treated Tca8113 was changed with marked increase in G 2 /M phase compared with untreated Tca8113 (62.8% vs 19.7%, P

The fermentation conditions of lipase production by Geotrichum candidum Y162 were optimized. Initially, the most suitable carbon olive oil, nitrogen source soybean flour and NH4Cl, salt BaCl2 and MgCl2 were selected according to single factorial experiments respectively. Based on the result, screening methodology Plackett-Burman design was used to evaluate the effects of twelve factors related to lipase production and three statistically significant factors olive oil, BaCl2 and NH4Cl were selected. The path of steepest ascent was used to approach the optimal region of lipase production subsequently. Then, the optimal combined concentration for maximum enzyme activity were further optimized by response surface methodology and determined as follows: olive oil 2.35%, BaCl2 0.36%,and NH4Cl 4.69%.The optimization of culture conditions of G.candidum Y162 led to a 2.25-fold increase in lipase production relative to initial result 14.16 U/ml, which indicate that single factor in combination with response surface methodology is an effective method for optimization of lipase production conditions by G.candidum Y162.

0.05).Conclusion The results suggested that the polymorphism of CCR2-64I was not associated with hypertension in Han Chinese elders.

BACKGROUND: Techniques in the focal cerebral ischemia model in mice have been well developed in some foreign countries. However, rats are commonly used in cerebral ischemia studies due to resource availability in China.OBJECTIVE: To establish reliable and reproducible focal cerebral ischemia reperfusion model in mouse to explore the molecular mechanism of cerebral ischemia reperfusion process in genetic level.DESIGN: Randomized controlled study.SETTING: Fundamental Medical Research Institute of Chengde Medical College. MATERIALS: The experiment was carried out in Fundamental Medical Research Institute of Chengde Medical College from September 2002 to May 2003. Totally 30 Kunming mice (25 to 30 g), provided by Experimental Animal Center, Chengde Medical College, were randomly grouped as follows: control group, 6, 3-hour occlusion and 18-hour, 24-hour reperfusion, with 6 mice in each group respectively.INTERVENTIONS: Nylon thread (qb0.128 mm) was soaked in paraffin wax and inserted into internal carotid artery in mouse to reversibly occlude the middle cerebral at the right side after 3 hours, then was removed, and reperfusion was performed in 18, 24 hours, respectively.MAIN OUTCOME MEASURES: The infarct volume was observed and neurological deficit scored was analysis.of mice in operation group was shown as head turning to left, adduction of left forelimb, internal rotation of shoulder, decrease of muscular tension of left forelimb, unable to straighten completely during tail lifted. At independent activity, mice turned to left as the left hidlegs as the center of a circle; under the abdomen, left forelimb was crossed with right forelimb as scissor shape. Palsy of left limbs was observed obviously, especially forelimb.tion was shown clearly with TTC. The infarct volumes were (13±2.3) mm3 and (16±4.5) mm3 for 18 hours and 24 hours reperfusion and 3-hour ischemia, respectively. Pathological changes were observed under light microscope after ischemia. The infarct volume increased as the increasing of reperfusion time, including 3-hour blocking and 18-hour and 24-hour reperfusion.CONCLUSION: Using suture method to establish focal cerebral ischemia reperfusion model in mice, it is less invasion and trauma without requiring skull opening. Ischemia position is relatively fixed, thus, ischemia reperfusion time can be controlled precisely. It is also an ideal animal model to study pathological changes in cerebral vascular diseases and an efficient tool to study the therapeutic effect of medicine after surgery.

Adult ; Aged ; Asteraceae ; Drugs, Chinese Herbal ; adverse effects ; Female ; Hepatic Veno-Occlusive Disease ; chemically induced ; Humans ; Male ; Middle Aged ; Retrospective Studies

Melanin is formed by oxidative polymerization of phenolic compounds,basically different kinds of melanin come from different organisms.DOPA melanin and DHN melanin have same physical and chemical characters although they have different biosynthetic pathway.DHN melanin is common in plant fungi and plays an important role on infection.The melanin accumulates in the fungal cell walls and prevents organic and inorganic molecules penetrating out,that insures appressorium's pressure and infection ability.This paper has reviewed the kinds and characters,especially discussed the role of melanin during pathogen infection based on our some research.

Objective To determine the effect of endomorphin (EM) on colonic electromyography activity and investigate the pathogenesis of slow transit constipation (STC). Methods An experimental rat model of slow transit constipation was constructed by contract laxatives mixed with the feed. The changes of colonic electromyography and reaction to endomorphin 1 and endomorphin 2 were examined. Results Compared with the control group, the frequency and amplitude of slow wave in cathartic colon rats were decreased significantly. Endomorphin 1 and endomorphin 2 significantly decreased the amplitudes of slow wave, but did not change the frequencies of slow wave. The effect of endomorphin 1 was more pronounced than that of endomorphin 2, which could be reversed by the morphine antagonist Naloxone in concentration-dependent manner. Endomorphin could not block the stimulating effect of acetylcholine. Conclusions Endomorphin can influence the colonic electromyography activity and intestine motility of cathartic colon rats, and may be involved in the pathologic mechanism of slow transit constipation.

AIM:To determine whether acellular porcine cornea stroma (APCS) could support the growth of the rabbit corneal cells in vitro.METHODS: APCS was prepared. The rabbit's corneal epithelium and stromal cells were cultured and seeded on, APCS in vitro.The observation of phase contrast photograph and histological examination were performed.RESULTS: Histological examination showed the epithe- lium grew on the scaffold of APCS in 2-3 layers at 10th day. The stromal cells adhered to the surface of the scaffold after 24 hours and invaded into the interlaminar of the material at 5th day.CONCLUSION: These results indicate that APCS can support the growth and proliferation of the corneal epithelium and stromal cells in vitro.

The experiment's aim was to optimize the processing technology of Xanthii Fructus which through comparing the difference of UPLC fingerprint and contents of toxicity ingredient in water extract of 16 batches of processed sample. The determination condition of UPLC chromatographic and contents of toxicity ingredient were as follows. UPLC chromatographic: ACQUITY BEH C18 column (2.1 mm x 100 mm, 1.7 microm) eluted with the mobile phases of acetonitrile and 0.1% phosphoric acidwater in gradient mode, the flow rate was 0.25 mL x min(-1) and the detection wavelength was set at 327 nm. Contents of toxicity ingredient: Agilent TC-C18 column (4.6 mm x 250 mm, 5 microm), mobile phase was methanol-0.01 mol x L(-1) sodium dihydrogen phosphate (35: 65), flow rate was 1.0 mL x min(-1), and detection wavelength was 203 nm. The chromatographic fingerprints 16 batches of samples were analyzed in using the similarity evaluation system of chromatographic, fingerprint of traditional Chinese medicine, SPSS16.0 and SIMCA13.0 software, respectively. The similarity degrees of the 16 batches samples were more than 0.97, all the samples were classified into four categories, and the PCA showed that the peak area of chlorogenic acid, 3,5-dicaffeoylquinic acid and caffeic acid were significantly effect index in fingerprint of processed Xanthii Fructus sample. The outcome of determination showed that the toxicity ingredient contents of all samples reduced significantly after processing. This method can be used in optimizing the processing technology of Xanthii Fructus.
Caffeic Acids ; analysis ; toxicity ; Chemistry, Pharmaceutical ; Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; analysis ; toxicity ; Quinic Acid ; analogs & derivatives ; analysis ; toxicity ; Xanthium ; chemistry ; classification