A high Streptolydigin-producing strain Streptomyces lydicus AS 4.2501-L8 with genetic stability was obtained from the original strain S. lydicus AS 4.2501-P28 by mutagenesis with UV and acridine orange, followed by resistance selection. Its yield of Streptolydigin was 177.0 ?g/mL, 96.2% higher than the original strain.

Aged ; Female ; Fibroma ; pathology ; Fibroma, Ossifying ; pathology ; Gingival Neoplasms ; pathology ; Humans

The authors explained the process of organizing and implementing of the designed experiments.The designed experi- ments can improve students' creative thinking ability and activate students'initiative and meanwhile,it can improve teachers' level and contribute to making progress in teaching and studying although there are still some problems to solve.

OBJECTIVETo examine the effects of Han's acupoint and nerve stimulator (HANS) electroacupuncture on the expression of NPY in periaqueductal grey (PAG) of heroin addicted rats.

METHODSHeroin was injected subcutaneously according to the principle of daily increasing dose in rats of experimented group. The ability of special learning and memory were tested by Morris water maze; The expression of NPY in PAG of rat were detected by immunohistochemistry.

RESULTS(1) Escape latency and searching distance in heroin-addiction group were significantly increased compared with those of normal group during the place navigation test (P < 0.05). However, in acupuncture group, escape latency and searching distance was obviously shortened compared with those of heroin-addiction group (P < 0.05). The exploring time and distance of original platform area in proportion to the total distance in heroin-addiction group significantly decreased compared with those of normal group during spatial probe test (P < 0.05). The exploring time and distance of original platform area in proportion to the total distance in acupuncture group was increased compared with those in heroin-addiction group (P < 0.01). (2) The expression of NPY of heroin-addiction group was lower than that in normal group in PAG, while those of acupuncture group was higher than that in the heroin-addiction group (P < 0.05).

CONCLUSIONThe learning and memory induced by heroin-addiction could be reversed and the expression of NPY in PAG was increased by HANS in rats.

Animals ; Electroacupuncture ; Heroin Dependence ; metabolism ; Male ; Maze Learning ; Memory ; Neuropeptide Y ; metabolism ; Periaqueductal Gray ; metabolism ; Rats ; Rats, Wistar

Objective To look for the genes of Schistosoma japonicum related to the Schistosoma-resistance of Microtus fortis.Methods The fresh sera of Microtus fortis were used to screen a T7 phage display cDNA library from worms of Schistosoma japonicum established in our lab.The positive clones were sequenced and functionally analysed through bioinformatics.Results The specific phages binding to the sera of Microtus fortis were enriched 857-fold after three rounds of biopanning,and 58 positive clones picked at random were sequenced and 10 ESTs were obtained.BLASTn results showed that 7 ESTs had 99%-100% similarity to the genes of Shistosoma japonicum reported in GenBank and 1 EST had 82% similarity to a zinc finger protein encoden gene from Pan troglodytes.The results of these ESTs function prediction indicated most of them were involved in the regulation of gene expresion of Schistosoma japonicum.Conclusions Several target genes of Schistosoma japonicum related to the Schistosoma-resistance of Microtus fortis are obtained and those would lay foundation to expatiate the native resistance mechnism of Microtus fortis to Schistosoma japonicum.

Objective To investigate whether gastroesophageal reflux can cause asthma-like pathophysiological changes and its mechanism.Methods Sixty BALB/c mice were randomly divided into 4 groups:group A was gastroesophageal reflux control group,group B was asthma control group,group C was gastroesophageal reflux group,and group D was asthmatic group.The asthmatic models were replicated with ovalbumin(OVA) and aluminum hydroxide,and gastroesophageal reflux models were replicated with hydrochloric acid solution pepsin.After the last inhaling ovalbumin and slow perfusion,the airway pressure was detected,and eosinophil (EOS) and neutrophil granulocyte in bronchial lavage fluid were counted.The flow cytometer was used to determinate IL-4,IFN-γ,and Th1/Th2 ratio changes of spleen cells;Lung tissue and esophagus sections were stained with HE,and pathological changes of lung tissue and esophagus were observed.Results In group C and group D,the airway hyper-responsiveness was significantly increased compared with group A and group B,and the differences were statistically significant (all P ＜ 0.05).In group C and group D,IL-4were significantly increased,while IFN-γand Thl/Th2 ratio were significantly decreased than that in the group A and B group,the differences were statistically significant (all P ＜ 0.05).EOS of group C and group D accounted for a high percentage of total cells and they were significantly higher than that in group A and group B,and the differences were statistically significant (all P ＜ 0.05).Through lung tissue biopsy,in group C and group D,bronchial lumen deformation,infiltration of inflammatory cells around the wall,basement membrane thickening,inflammatory cell infiltration around the wall,peripheral vascular edema,enlarging alveolar cavity,alveolar wall thinning,fracture,part of alveolar fusion into bullace of lung,could be observed.The lung pathological section showed that the endothelial cells in group A and group B were integrated and had no denaturation or necrosis,and there was no inflammation cell infiltrate around.EOS biopsy could be observed in group A and group B of lower esophagus markedly submucosal edema,submucosal inflammatory cell infiltration,and keratin hyper function,visible bacteria group A group B and group D were basic ally normal,with no pathological changes.Conclusions Gastroesophageal reflux can induce Th1/Th2 decreasing,airway hyper-responsiveness and pathophysiological changes similar to asthma.

Multi-central randomized controlled method was used to scientifically verify indications of 33 acupoints and provide definite clinical basis for the indications of single acupoint. Of the 52 studies, 40 studies showed that the therapeutic effect in acupuncture observation groups were better than the control group; 11 studies showed similar therapeutic effect of the two groups, and 1 study showed the acupuncture observation group was worse than the control group. Therefore, results indicate that in a certain observation cycle, acupuncture at single acupoint have different effects on diseases.
Acupuncture Points ; Humans ; Randomized Controlled Trials as Topic

OBJECTIVEUsing PCR-RDB to establish a new method for HBV genotyping, and to survey the distribution of HBV genotypes in the Foshan area.

METHODSBiotin-labeled primers for amplification of HBV region X (nt1550-1789) were used to amplify extracted HBV DNA. HBV was genotyped by hybridization of the PCR products with immobilized specific probes (genotype A to F) on C membrane. Color development was achieved by adding POD and TMB. A judgment was made according to color reactions. The reliability of this new method was verified by gene sequencing. 300 samples of HBV DNA-positive sera from the Foshan area were genotyped using this assay.

RESULTSOf the 300 sera genotyped by PCR-RBD, 147 (49.0%) cases were genotype B, 136 (45.3%) were genotype C, 1 (0.3%) genotype D, and 12 (4.0%) were mixtures of genotype B and C, and 4 (1.3%) were mixtures of genotype C and D. No genotype A, E or F were found. The results of PCR-RDB genotyping were consistent with the results obtained with sequence analysis.

CONCLUSIONThis newly established HBV genotyping system proved to be sensitive, specific, precise and economic, and should be suitable for clinical practice and epidemic study. The results of HBV genotyping show that genotype B and C are the predominant genotypes in the Foshan area.

DNA, Viral ; genetics ; Female ; Genotype ; Hepatitis B ; virology ; Hepatitis B virus ; classification ; genetics ; Humans ; Male ; Oligonucleotide Array Sequence Analysis ; methods

OBJECTIVETo examine the expression of matrix metalloproteinase-2 (MMP-2) and to evaluate its correlation with mesorectal metastasis in middle and lower rectal cancer.

METHODSThe resected primary tumors from 56 patients with middle and lower rectal cancer who received total mesorectal excision were studied from Dec. 2001 to Jul. 2003.

RESULTSThe MMP-2 expression was positive in 42 (75%) cases. The positive rate of MMP-2 expression was 88.9% in T3 tumors and 69.6 % in T2 tumors respectively, while only 33.3% in T1 tumors (P=0.013). MMP-2 was positive in 91.2% (31/34) infiltrative rectal carcinomas while 40.0% (6/15) expansive rectal carcinomas (P=0.001). Mesorectal metastasis was detected in 36 (64.3%) of 56 cases. The expression of MMP-2 was positive in 31 (86.1%) of the 36 patients with mesorectal metastasis, while in 11(55%) of the 20 patients without mesorectal metastasis (P=0.01).

CONCLUSIONSThe expression of MMP-2 in middle and lower rectal cancer is significantly associated with depth of tumor invasion and Ming classifications. The high expression of MMP-2 may play an important role in the development of mesorectal metastasis in middle and lower rectal cancer.

Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Mesentery ; pathology ; Middle Aged ; Neoplasm Metastasis ; Prognosis ; Rectal Neoplasms ; metabolism ; pathology

OBJECTIVETo observe the neuro-protective effects of genistein (Gen) and folic acid (FA) on neurons membrane and mitochondrial membrane damaged by β-amyloid peptides 31-35 (Aβ31-35).

METHODSThe primary cultured rat cerebral cortical neurons were randomly divided into DMEM (control), Aβ31-35 (25 µmol/L), Gen (Gen 27 µg/ml), FA (FA 40 µg/ml) and Gen + FA (Gen 27 µg/ml + FA 40 µg/ml). Gen and/or FA were added two hours before Aβ31-35 addition. After twenty four hours, MTT assay was performed to measure the viability of cultured neurons. Fluorescence polarization was performed to observe the neuron cell membrane fluidity. The mitochondrial membrane potential (MMP) was determined to investigate the alteration of mitochondrial structure and function of neurons by laser scanning confocal microscope and a flow cytometer was used to investigate the activation of mitochondrial permeability transition pore (MPTP). Each experiment was repeated three times.

RESULTSCompared with group Aβ31-35 (0.845 ± 0.050, F = 4.931, P < 0.05), the absorbance was significantly higher in group Gen (0.982 ± 0.110, t = 3.523, P < 0.01), FA (0.947 ± 0.061, t = 2.745, P < 0.01) and Gen + FA (0.996 ± 0.090, t = 3.966, P < 0.01). The viscosity of cell neuron membrane in group Gen (1.75 ± 0.28, t = 2.085, P < 0.05), FA (1.66 ± 0.37, t = 2.357, P < 0.05) and Gen + FA (1.50 ± 0.20, t = 3.784, P < 0.05) was significantly lower than that in group Aβ31-35 (2.11 ± 0.44, F = 5.529, P < 0.01), which indicated the cell membrane fluidity was significantly higher in group Gen and/or FA than that in group Aβ31-35. MMP was significantly decreased by Aβ31-35 (3.364 ± 1.140, t = 3.949, P < 0.01) when comparing to control group (6.383 ± 1.683), while it was significantly increased by Gen (5.286 ± 1.792, t = 2.406, P < 0.05), FA (5.884 ± 2.022, t = 2.887, P < 0.01) and Gen + FA (6.120 ± 2.124, t = 3.304, P < 0.01) when comparing to group Aβ31-35 (F = 7.585, P < 0.01). MPTP was activated by Aβ31-35 and Gen and/or FA could reverse this progress.

CONCLUSIONGen and/or FA could protect the neuronal and mitochondrial membrane from the impairment induced by Aβ31-35.

Amyloid beta-Peptides ; adverse effects ; Animals ; Cells, Cultured ; Cerebral Cortex ; drug effects ; Folic Acid ; pharmacology ; Genistein ; pharmacology ; Membrane Potential, Mitochondrial ; drug effects ; Neurons ; drug effects ; metabolism ; Neuroprotective Agents ; pharmacology ; Peptide Fragments ; adverse effects ; Rats ; Rats, Wistar