RESUMO
Three myelin proteins, Nogo-A, MAG and OMgp, transduce their neurite-outgrowth inhibitory signal through a common receptor complex: NgR/ p75NTR (or TROY). Recently, LINGO-1 is identified as another essential component and regulator for the Nogo-66 receptor/p75 signaling complex. LINGO-1 is restricted to express in CNS, neuronal LINGO-1 is shown to be involved in the signal transduction from three myelin proteins, and Lingo-1 in oligodendrocyte negatively regulates the differentiation and myelination of oligodendrocyte. To investigate the potential activity of LINGO-1 in neuronal apoptosis, LINGO-1-Fc fusion protein including the extracellular LRR and IgC2 domain, was used as functional antagonist to study its protective effect on low-potassium induced apoptosis of cerebellar granule neurons (CGNs). In judgement of the apoptotic nuclei stained by Hoechst, LINGO-1-Fc pretreatment for 2 h significantly prevents apoptosis of CGNs. Although GST-LINGO-1 protein, including the LRR domain, binds to the CGN cultures in the same way with LINGO-1-Fc, it doesn't prevent the apoptosis of CGNs. These results indicate that LINGO-1-Fc fusion protein prevents low-potassium induced apoptosis of cerebellar granule neurons in certain conditions and this activity is probably IgC2 domain dependent.
RESUMO
Objective To investigate the method of establishing lymph node metastasis model for gastric cancer in nude mice.Methods Human poorly differentiated gastric cancer SGC-7901 ceils were cul- tured,inherited,amplified and collected in vitro,and were inoculated in nude mice subcu.taneously.After pas- saging six generations,the subcutaneous tumor was orthotopically implanted in nude mice.The mice were then sacrificed on the 9th week after implantation.Serum CEA density was detected using radio-immunity method. Orthotopically implanted tumors,remote organ metastases as well as lymph node metastasis were observed macrescopically and histologically.Results The successful rate of orthotopically transplantion of gastric can- cer was 100 %.The rate of perigastric lymph node metastases was 93.3 %.Local infiltration and remote metastasis were observed.The level of serum CEA in nude mice bearing tumor was significantly higher than that of normal nude mice(P
RESUMO
Objective To develop a new method for rapid detection of E.Coli.with a new substrate Na p nitrophenyl ? D glucuronate (PNP Glucu Na). Method The test paper was immersed with of Na p nitrophenyl ? D glucuronate which was synthesized by us and another paper with culture medium and phorphate buffer.Colour change was observed to detect the E.coli. Results An E.coli concerntration of 4?10 7 took 0.5 hour, while a concentration of 4?10 0 took 12 hours. 138 strains of E.coli and 190 strains of other bacteria were examined . The sensitivity was 94.2% and the specificity was 92.6%. Conclusion This method is rapid, accurate, simple, and economical for detecting E.coli.
RESUMO
Objective To observe the molecular weight distribution of soybean peptides prepared by complex enzyme hydrolysation and tumor inhibitory effect in vivo or in vitro. Method The soybean protein was enzymolyzed to soybean peptides by Flavourzyme, Alealase and neutral protease, at(50-55)℃, followed by separation, absorption,affination, ultra centrifuge and spray drying. The soybean peptides were passed Sephadex G25 column at 0.5ml/min with 0.1mol/L Tris-HCl buffer. The fragment of fluid collected was determined by UV at 280nm and HPLC. Then the molecular weight distribution was calculated. The inhibitory effect on ansplant glioma (G422) at dose 1.25, 2.5 and 5g/kg bw (ig daily for 11 d) was tested in mice and in Hep-2 in vitro. Results The peptides contents in three batches were 54.6%, 51.9%, 51.8% respeclively. The molecular weight