Technological improvement for microorgnism isolation is important since isolation provides substantial materials for the exploitation of new microbial resources. In this study, a new approach, dispersion and differential cetrifugation (DDC), was applied in the isolation of acidophilic and acidoduric streptomycetes from 12 acid soil samples. Contrast with traditional method, the new approach yielded satisfying results with 2 - 20 times isolation efficiency and good selectivity. 45 representatives out of 249 streptomycetes isolates, which belonged to 12 color groups, showed morphology and cell wall type consistent with streptomycetes. The optimum pH range for their growth were between pH 4.5 - 5.5. It is proved that we succeeded in the rare-streptomycetes isolation using DDC approach.

Background and purpose:Chemotherapy plays an important role in the treatment of breast carcinoma by inhibiting the tumor growth and inducing the apoptosis.MAPK transduction pathway is closely related to proliferation and apoptosis of varieties of tumor cells,inhibition of MAPK pathway may increase the efficiency and decrease the toxicity of chemotherapy.Our study was to investigate the effect of MEK inhibitor PD98059 in response of breast cancer cell lines to Epirubicin.Methods:Human breast cancer cell lines MCF-7 and MCF-7/ADR were used as cell models.Epirubicin(EADM),PD98059(inhibitor of MAPK Kinase-MEK),or EADM+PD98059 was added into the culture medium,the expression of MEK2 and p-ERK were measured by Western blot,the growth of the two cell lines were measured by MTT.Results:ERK activity was elevated in MCF-7 after the treatment of EADM,the cells were more sensitive to EADM if combined with PD98059,while in MCF-7/ADR,ERK activity kept unchanged after EADM treatment,and PD98059 has no effect on the sensitivity of cells to EADM.Conclusion:MAPK signal transduction may be activated in some cells treated by EADM,adding inhibitor of MAPK signal transduction could improve the sensitivity of the cells to EADM.

The GFP(green fluorescence protein)-streptavidin(SA) bi-functional fusion protein was generated and characterized in order to demonstrate novel platform for efficiently and durably modifying the cell surface with SA-tagged bi-functional proteins.The GFP-SA/pET24d construct was generated and expressed in BL21(DE3) host bacteria at the high level.The recombinant protein GFP-SA was purified through the Ni-NTA affinity chromatography,and then refolded.After biotinylation B16 tumor cells were modified with GFP-SA bi-functional fusion protein and then subjected to fluorescent microscopy and FACS analysis.The effect of surface modification on the viability and growth of B16.F10 tumor cells was evaluated by MTT staining.The GFP-SA recombinant fusion protein was expressed in BL21(DE3) at about 20 % of total bacterial proteins.The GFP-SA bi-functional fusion protein exhibited the bi-functionality,i.e.,SA-mediated high-affinity binding to biotinylated cell surfaces and GFP-emitted green fluorescence.The cell surface modification with GFP-SA bi-functional fusion protein did not affect the viability and growth of the modified B16.F10 tumor cells significantly.The GFP-SA bi-functional fusion protein was obtained and could be displayed efficiently on the surface of the biotinylated B16.F10 tumor cells through the specific and tight interaction between streptavidin and biotin,thus can be used as good trace protein and experimental control in the development of surface-modified tumor vaccine.

By reverse transcription-polymerase chain reaction (RT-PCR), an open reading frame of pathogenesis-related protein 1 (PR1) was isolated from Panax notoginseng and named as PnPR1. Molecular and bioinformatic analyses of PnPR1 revealed that an open reading frame of 501 bp was predicted to encode a 166-amino acid protein with a deduced molecular mass of 18.1 kD. Homology analysis showed that the deduced amino acid sequence of PR1 protein of Panax notoginseng had a high similarity with other higher plants had the same conservative structure domain of cysteine-rich secretory protein (CAP). The recombinant expressed plasmid pET28a(+)-PnPR1 was expressed in Escherichia coli BL21. The expression conditions were optimized by induction at different times, different temperatures, different IPTG concentrations and different giving times. The optimum expression condition was 0.4 mmol.L-1 IPTG at 28 degrees C for 20 h. The successful expression of PnPR1 provides some basis for protein purification and preparation of the monoclonal antibody.
Amino Acid Sequence ; Cloning, Molecular ; Escherichia coli ; metabolism ; Molecular Weight ; Open Reading Frames ; genetics ; Panax notoginseng ; chemistry ; Phylogeny ; Plant Proteins ; genetics ; metabolism ; Plants, Medicinal ; chemistry ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Alignment

Objective To investigate the possible role of interstitial cell of Cajal (ICE)in the pathogenesis of diabetic gastroparesis and the protective effect of"Xiaopi prescription (消痞方)".Methods Fifty healthy male Spregue-Dawley (SD) rats were randomly divided into 5 groups (each n=10):normal, model,and 3 Xiaopi prescription groups:low,middle and high dosages.Diabetes was induced by intravenous injection of alloxan,and equal amount of normal saline was intravenously injected in the normal group.Gastric lavage method was used to administer the traditional Chinese medicine decoction of Xiaopi prescription in corresponding amount (5,10 and 20 g?kg~(-1)?d~(-1)) in respective low,middle and high dosage groups.In the normal control group and diabetic model group,only equal amount of normal saline was administered into the stomach.Gastric emptying rate was measured by method of nutritious semisolid paste;c-kit positive cells of ICC were quantitatively measured with immunohistochemistry assay and computer image analysis system;c-kit mRNA positive cells were quantitatively measured with in situ hybridization and computer image analysis system.Results①Gastric emptying rate:The rate was significantly lower in the model group than that in the normal control group (P0.05),but higher than those in the model group and the low dosage group (all P0.05).②c-kit immmunohistochemistry:c-kit positive cell presented yellow in color,and its membrane was stained yellow,this kind of cells primarily were distributed around the neural plexus in the inter-space between the circular and longitudinal muscular fibers, and around the ganglionic cells forming"sheath-like"structure.The results of numbers of c-kit positive cells in the various groups:the number of the cells in the model group was significantly lower than that in the normal group (P0.05),but the numbers in the former two dosage groups were obviously higher than those in the model group (all P0.05),being significantly lower than that in the normal group,middle and high dosage groups (all P0.05),but obviously higher than those in the model group (all P0.05),being significantly lower than that in the normal,middle and high dosage groups (all P

Objective： A prospective randomized trial was performed to evaluate the contribution of neoadjuvant chemotherapy in the patients with locoregionally advanced nasopharyngeal carcinoma. Methods： The patients with locoregionally advanced nasopharyngeal carcinoma were treated with either radiotherapy alone (RT group) or neoadjuvant chemotherapy plus radiotherapy (CT/RT group). Neoadjuvant chemotherapy consisting of 2-3 cycles of cisplatin (20 mg/m2 on Day 1 to Day 5), bleomycin (7 mg/m2 on Day 1 and Day 5), and 5-FU (500 mg/m2 on Day 1 to Day 5) followed by radiotherapy was given to CT/RT group. All patients were treated in a uniform definitive-intent radiation therapy in two groups. Results： From 1992 to 1993, 457 patients were enrolled and 440 patients (221 in RT group, 219 in CT/RT group) were assessable. The 5-year overall survival (OS) rates were 62％ for CT/RT group and 55％ for RT group (P=0.1335)； The 5-year relapse free survival rate was 48％ versus 58％ , respectively (P=0.0539). The 5-year free local recurrence (FLR) rate was 82％ for CT/RT group, 74％ for RT group (P=0.0412). There was no significant difference in free distant metastasis (FDM) between two treatment groups (CT/RT group, 79％ ; RT group, 75％ ; P=0.4177). Subgroup analyses showed that neoadjuvant chemotherapy improved local control in patients with T3-4 disease, and had no effect in preventing distant metastases in patients with N2-3 disease. Conclusion： Despite improving FLR and RFS, neoadjuvant chemotherapy and radiatherapy failed to gain other survival benefit or reduce distant metastases in patients with locoregionally advanced nasopharyngeal carcinoma. The indication for neoadjuvant chemotherapy is proposed.

OBJECTIVETo provide new germplasm materials for breeding new varieties of Pseudostellaria heterophylla.

METHODThe method of single plant selection was adopted, with the comparative experiments being carried out under the same conditions in Shibing county. The 8 plants of Shibing SB-4 were compared respectively with factor analysis for 27 phenotypic traits and 8 yield traits, and single factor variance analysis for the contents of polysaccharides.

RESULTUsing factor analysis, 27 phenotypic traits were classified into 7 principal divisors and 8 yield traits were simplified into 3 principal divisors. The 4 strains of P. heterophylla, ZT-01, ZT-02, ZT-06 and ZT-07, performed better than others in the phenotypic traits, and ZT-01, ZT-02, ZT-03 and ZT-07 in the yield traits. The contents of polysaccharides of ZT-01, ZT-02, ZT-05 and ZT-08 showed significantly higher value.

CONCLUSIONThere is significant difference among the 8 strains of P. heterophylla in phenotypic traits, yield traits and quality traits, making it possible to select certain strains for different purposes. ZT-01 and ZT-02 can be breaded further. ZT-06 and ZT-07 were used as ornamental cultivars for its great phenotypic traits. ZT-03 with good resistance and high yield was taken as resistant variety, and ZT-05 would face next selection on the basis of its high content of polysaccharide.

Breeding ; Caryophyllaceae ; chemistry ; growth & development ; China ; Phenotype ; Polysaccharides ; analysis

Animals ; Antibodies, Monoclonal ; immunology ; Atrazine ; analysis ; immunology ; Chromatography, Gas ; Chromatography, High Pressure Liquid ; Enzyme-Linked Immunosorbent Assay ; Food Contamination ; analysis ; Herbicides ; analysis ; immunology ; Mass Spectrometry

BACKGROUNDThis study was designed to investigate the potential pathogenicity of Mycoplasma penetrans (M. penetrans) and its molecular mechanisms responsible for the induction of iNOS gene expression in mouse macrophages stimulated by lipid-associated membrane proteins (LAMPs) prepared from M. penetrans.

METHODSMouse macrophages were stimulated with M. penetrans LAMPs to assay the production of nitric oxide (NO). The expression of inducible nitric oxide synthase (iNOS) was detected by RT-PCR and Western blotting. The activity of nuclear factor kappaB (NF-kappaB) and the effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappaB, on the production of nitric oxide and the expression of iNOS were also assessed in mouse macrophages treated with M. penetrans LAMPs by indirect immunofluorescence and Western blotting.

RESULTSM. penetrans LAMPs stimulated mouse macrophages to produce nitric oxide in a dose- and time-dependent manner. The mRNA and protein levels of iNOS were also upregulated in response to LAMP stimulation and inhibited by PDTC treatment. M. penetrans LAMPs were found to trigger NF-kappaB activation, a possible mechanism for the induction of iNOS expression.

CONCLUSIONThis study demonstrated that M. penetrans may be an important etiological factor of certain diseases due to the ability of M. penetrans LAMPs to stimulate the expression of iNOS, which is probably mediated through the activation of NF-kappaB.

Animals ; Bacterial Proteins ; pharmacology ; Cells, Cultured ; Enzyme Induction ; Lipoproteins ; pharmacology ; Membrane Proteins ; pharmacology ; Mice ; Mycoplasma penetrans ; chemistry ; NF-kappa B ; metabolism ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase ; biosynthesis ; Nitric Oxide Synthase Type II ; RNA, Messenger ; analysis

OBJECTIVETo investigate the influence of escharectomy during shock stage on systemic and intestinal immune function and its mechanism in scalded rats.

METHODSNinety-six Wistar rats were employed in the study of which 8 were used as normal control group. The donor skin from the trunk in twenty-four rats were preserved in liquid nitrogen. The other 64 rats were subjected to 30% full-thickness scalding, and they were randomly divided into A (n = 24, no treatment after scalding), B (n = 24) and C (n = 16) groups. Physiological saline was intraperitoneally injected (50 ml/kg) on the 24 post-scalding hours to the rats in the B and C groups. The rats in B group underwent escharectomy during shock stage, and the excision wounds were covered with the cryo-preserved alloskin. The rats in C group received the same treatment as in B group but at 72 post-scalding hours. The change in the proliferative ability of splenic lymphocytes, the plasma and intestinal tissue content of interleukin 2 (IL-2), the contents of sIgA in intestinal mucus, and the content of DAO in the intestinal tissue were observed on 2, 4 and 8 post burn days (PBD) in A and B groups and also on 4 and 8 PBD in C group, respectively.

RESULTSThe splenocytic proliferative ability, IL-2 level in the plasma and intestinal tissue, and the sIgA content in intestinal mucus in the rats in A, B and C groups were lower than that in control group at all time points (P < 0.05). The proliferative ability of splenic lymphocytes in B group on 4 and 8 PBD and in C group on 8 PBD respectively was similar to that in control group. Whereas the IL-2 content in plasma and in intestinal tissue was higher in B and C groups than that in A group (P < 0.01). The sIgA content in intestinal mucus in B group was twice of that in C group respectively [(3.51 +/- 2.14) mg/g vs (1.40 +/- 0.64) mg/g, (3.03 +/- 0.95) mg/g vs (1.52 +/- 1.26) mg/g (P < 0.05 or P < 0.01)] on 4 and 8 PBD. The DAO activity in the intestinal tissue in A group was lower than that in control and B group (P < 0.05) on 4 and 8 PBD.

CONCLUSIONEscharectomy during shock stage might be beneficial to the recovery of the systemic and intestinal immune functions in rats with scalding injury.

Animals ; Burns ; immunology ; surgery ; Immunoglobulin A, Secretory ; immunology ; Interleukin-2 ; immunology ; Intestines ; immunology ; Male ; Rats ; Rats, Wistar ; Shock, Traumatic ; immunology ; surgery ; Skin Transplantation ; immunology ; T-Lymphocytes ; immunology