The purpose of this study is to obtain effective and stable bacteriocin-like substance from lactic acid bacteria. Lactobacillus buchneri KLDS1.0364,which was isolated from fermented cream,a traditional dairy product in Inner Mongolia,could produce bacteriocin-like substance. The bacteriocin-like substance produced by KLDS1.0364 was partially purified and the characteristics were studied. The bacteriocin-like substance was purified by SP-Sepharose fast flow cation exchange chromatography. The molecular weight of the bacteriocin-like substance was 21.6kD,as determined by tricine-SDS-PAGE. The bacteriocin-like substance remained stable after 30 min at 121℃ and after 2 h of incubation during pH 2～10. Complete inactivation of antimicrobial activity was observed after treatment of the bacteriocin-like substance with several proteinases. Treatment with catalase and ?-amylase did not result in any changes of antimicrobial activity. The mode of action of the bacteriocin-like substance is bactericidal. It exhibited a broad spectrum of antagonistic activity against various species of Gram-positive bacteria,Gram-negative bacteria and fungi.

Animals ; Avoidance Learning ; physiology ; Cues ; Extinction, Psychological ; physiology ; Fear ; physiology ; Male ; Mental Recall ; physiology ; Rats ; Sleep Deprivation ; physiopathology ; Sleep, REM ; physiology

Animals ; Estrogens ; metabolism ; Gene Expression Regulation ; Humans ; Osteoarthritis ; complications ; genetics ; metabolism ; Pain ; etiology ; Pain Measurement ; Temporomandibular Joint ; pathology ; Temporomandibular Joint Disorders ; complications ; genetics ; metabolism ; Wnt Signaling Pathway

OBJECTIVETo study the effect of ginsenoside Rb1 on GSKbeta/IDE signal transduction pathway and Abeta protein secretion in hippocampal neurons of high glucose-treated rats.

METHODHippocampal neurons of 24 h-old newly born SD rats were primarily cultured, inoculated in culture medium under different conditions, and then divided into the normal group, the high glucose group, the LiCl group and the Rb1 group. After being cultured for 72 h, the expressions of their phosphorylated GSK3beta, total GSK3beta and IDE protein were detected by Western blotting analysis. The mRNA expressions of GSK3beta and IDE were determined by RT-PCR. The ELISA assay was used to detect the secretion of Abeta protein in cell supernatant.

RESULTCompared with the normal group, the high glucose group showed increase in the p/tGSK3beta protein ratio and the secretion of Abeta protein and decrease in IDE protein and mRNA (P < 0.05). Compared with the high glucose group, both Rb1 and LiCl groups showed decrease in the p/tGSK3beta protein ratio and the expression of Abeta protein and increase in IDE protein and mRNA expression (P < 0.05). Compared with the LiCl group, the Rb1 group showed no significant difference in the expressions of p/tGSK3beta protein, IDE protein, mRNA and Abeta protein expression. In addition, the GSK3beta mRNA expression of the four groups had no significant difference.

CONCLUSIONGinsenoside Rb1 may reduce the secretion of Abeta protein in hippocampal neurons by reducing the phosphorylation of GSK3beta, down-regulating the ratio of pGSK3beta/GSK3beta and upregulating the expression of IDE.

Amyloid beta-Peptides ; genetics ; metabolism ; secretion ; Animals ; Dietary Carbohydrates ; adverse effects ; Gene Expression Regulation ; drug effects ; Ginsenosides ; pharmacology ; Glucose ; adverse effects ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Hippocampus ; cytology ; Insulin ; metabolism ; Insulysin ; genetics ; metabolism ; Neurons ; cytology ; drug effects ; metabolism ; secretion ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

OBJECTIVETo explore the underwater decompression schedule for 100 m Trimix conventional diving operations and evaluate its safety through a simulated rabbits Trimix conventional diving.

METHODSAccording to the Haldane theory, the assumed time units, the classification of tissue compartments, the nitrogen super-saturation safety coefficient and the selection of methods used for the calculation of the simulated 100 m Trimix conventional diving schedule were properly selected, and the calculating method for the dive decompression schedule was thus firmly established. In our experiments, five tissue compartments were selected during the calculation of decompression schedule: 5 min, 10 min, 20 min, 40 min and 75 min, and the nitrogen super-saturation safety coefficient was calculated by 1.6. Eight New Zealand rabbits were performed a simulated 100 m Trimix dive program which was established according to the Haldane theory, and eight rabbits for intact group. The tissues wet/dry ratio and ethology were detected and observed before and after the simulated diving to evaluate the safety of decompression schedule.

RESULTSBy using the developed underwater decompression schedule, abnormal ethology changes in rabbits could not be observed after compression and decompression to the surface; and the tissues wet/dry ratio of simulated diving rabbits had no significant changes compared with the intact group (P > 0.05).

CONCLUSIONThe decompression schedule calculated by Haldane theory seemed to be safe and reliable, the diving breathing gas concentration did not cause oxygen toxicity and nitrogen narcosis among the dive rabbits, and dive efficiency was greatly improved by using enriched oxygen gas in UPTD safety range during decompression.

Animal Experimentation ; Animals ; Decompression ; Diving ; Helium ; Nitrogen ; Oxygen ; Rabbits

Food allergies, as a type of adverse immune-mediated reactions to ingested food proteins, have become a serious public health issue that harms children and adults health, with increasing incidence year by year. However, without effective therapy for food allergies, doctors-have mostly advised to avoid allergens and provided symptomatic treatment. According to the findings of many studies, allergic diseases are correlated with intestinal barrier function injury, as evidenced by the significant increase in the intestinal permeability among patients with food allergies. In this paper, recent studies on correlations between food allergies and intestinal barrier functions, intestinal barrier function injury mechanisms of allergic foods and food allergy intervention strategies based on intestinal barrier functions were summarized to provide reference for laboratory researches and clinical treatment of food allergic diseases.
Animals ; Food Hypersensitivity ; immunology ; therapy ; Humans ; Intestines ; immunology

A strain NK13 was screened for a certain extent asymmetric hydrolyze the rac-ketoprofen chloroethyl ester and identified as Bacillus megaterium. For the preparation of gene libraries, a positive clones was obtained from the tributyrin flat. The sequence of this esterase gene had been analysised, and contained the whole ORF of an esterase gene with the length of 933bp. The esterase gene of NK13 was compared with the esterase genes of GenBank and the result showed that the esterase gene of NK13 was a novel gene(GenBank accession nember DQ196347).The new esterase gene was inserted into the plasmid pET21b+, then the recombinant plasmid transformed E.coli BL21. After being induced by IPTG, it was expressed in the host strain. SDS-PAGE analysis showed that the relative molecular mass of the esterase was about 34kDa. The result of TLC and HPLC showed that the recombinant strain had higher conversion ration than templet strain. 47.4%of the rac-ketoprofen Chloroethl ester was hydrolyzed to ketoprofen by the recombinant strain in 45min. The (S)- ketoprofen enantiomeric excess, in the later,was 55.46%, which indicated that the esterase could hydrolyze (S)-ketoprofen chloroethyl ester firstly.

Nitrites play multiple characteristic functions in invasion and metastasis of hepatic cancer cells, but the exact mechanism is not yet known. Cancer cells can maintain the malignant characteristics via clearance of excess mitochondria by mitophagy. The purpose of this article was to determine the roles of nitrite, reactive oxygen species (ROS) and hypoxia inducing factor 1 alpha (HIF-1 α) in mitophagy of hepatic cancer cells. After exposure of human hepatocellular carcinoma SMMC-7721 cells to a serial concentrations of sodium nitrite for 24 h under normal oxygen, the maximal cell vitality was increased by 16 mg x (-1) sodium nitrite. In addition, the potentials of migration and invasion for SMMC-7721 cells were increased significantly at the same time. Furthermore, sodium nitrite exposure displayed an increase of stress fibers, lamellipodum and perinuclear mitochondrial distribution by cell staining with Actin-Tracker Green and Mito-Tracker Red, which was reversed by N-acetylcysteine (NAC, a reactive oxygen scavenger). DCFH-DA staining with fluorescent microscopy showed that the intracellular level of ROS concentration was increased by the sodium nitrite treatment. LC3 immunostaining and Western blot results showed that sodium nitrite enhanced cell autophagy flux. Under the transmission electron microscopy (TEM), more autolysosomes formed after sodium nitrite treatment and NAC could prevent autophagosome degradation. RT-PCR results indicated that the expression levels of COX I and COXIV mRNA were decreased significantly after sodium nitrite treatment. Meanwhile, laser scanning confocal microscopy showed that sodium nitrite significantly reduced mitochondrial mass detected by Mito-Tracker Green staining. The expression levels of HIF-1α, Beclin-1 and Bnip3 (mitophagy marker molecular) increased remarkably after sodium nitrite treatment, which were reversed by NAC. Our results demonstrated that sodium nitrite (16 mg x L(-1)) increased the potentials of invasion and migration of hepatic cancer SMMC-7721 cells through induction of ROS and HIF-1α mediated mitophagy.
Acetylcysteine ; pharmacology ; Autophagy ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Movement ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Liver Neoplasms ; pathology ; Mitochondrial Degradation ; Neoplasm Invasiveness ; Nitrites ; metabolism ; Reactive Oxygen Species ; metabolism ; Sodium Nitrite ; pharmacology

OBJECTIVESTo investigate whether antisense Bmi-1 plasmid could inhibit the proliferation of Jurkat cells.

METHODSThe antisense plasmid was constructed by PCR amplification of a 171 bp segment spanning Bmi-1 start codon and zinc finger structure and the PCR product was subsequently inserted reversely to plasmid pLNCX2. The final construct was confirmed through restriction enzyme digestion. G418 was added into the medium after the plasmid was successfully introduced into Jurkat cells by using lipofectin-mediated DNA transfection. The proliferation of Jurkat cells were determined by MTT and colony formation assays. Cell cycle was determined by flow cytometry. The p16 expression of Jurkat cells was studied by immunofluorescent histochemistry.

RESULTSThe growth rate of antisense Bmi-1 transfected Jurkat cells was significantly lower than that of the controls, and the colony forming capacity of the transfected cells decreased significantly (P < 0.01), the colony numbers being (90.7 +/- 9.07)/10(3) cells, (83.3 +/- 6.11)/10(3) cells and (56.0 +/- 5.56)/10(3) cells for control cells, empty plasmid transfected Jurkat cells and antisense Bmi-1 transfected Jurkat cells, respectively. The percentage of G, phase cells was increased and the p16 expression of antisense Bmi-1 transfected cells was significantly upregulated than that of control cells.

CONCLUSIONAntisense Bmi-1 can inhibit the growth and upregulate the expression of p16 of Jurkat cells in vitro.

Cell Cycle ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Genetic Vectors ; Humans ; Jurkat Cells ; Nuclear Proteins ; genetics ; Oligonucleotides, Antisense ; genetics ; Plasmids ; genetics ; Polycomb Repressive Complex 1 ; Proto-Oncogene Proteins ; genetics ; Repressor Proteins ; genetics ; Transfection

Objective To investigate the time-and dose-related expressions of vascular endothelial growth factor (VEGF) and glial fibrillary acid protein (GFAP) in cultured rat astrocytes after irradiation by X-ray,and discuss the possible relationship between astrocytes and radiation brain injury (RBI).Methods Rat astrocytes primarily cultured in vitro were exposed to X-ray at various doses (5,10,15 and 20 Gy) and kept culturing for 48 h,and some other rat astrocytes primarily cultured in vitro were exposed to 20 Gy and kept culturing for 4,12,24 and 48 h,respectively; normal control groups (without radiation) were used in all the above experiments.Immunofluorescence staining was employed to detect the level of GFAP and observe the cell morphology changes in each group; DAPI staining was used to observe the apoptosis of astrocytes; VEGF and GFAP expressions were detected by Western blotting.Results As compared with astrocytes in the normal control group,astrocytes in the radiation group showed increased number,hyperplasia,deformation,swelling of the cell body,thickening processus and deepened GFAP staining; and these changes became obvious following the increment of time and radiation doses.No significant differences on the astrocyte apoptosis rate were noted between the normal control groups and the radiation groups of different doses (P＞0.05).Western blotting indicated that the irradiation groups of different doses and the 20 Gy radiation groups of different exposing times had significantly different GFAP and VEGF protein expressions (P＜0.05).The expressions of GFAP and VEGF were up-regulated gradually with the increment of radiation doses in astrocytes and times of radiation (P＜0.05); as compared with the control group,20 Gy radiation groups of different exposing times showed time dependent VEGF expression from 4 to 24 h and time dependent GFAP expression from 4 to 48 h (P＜0.05).Conclusion X-ray irradiation can induce the activation of cultured rat astrocytes; VEGF and GFAP expressions in the reactive astrocytes increased in time and dose-dependent manners after X-ray irradiation; VEGF over-expression in reactive astrocytes after irradiation may play an important role in RBI.