Blocking effects of genistein on cell proliferation and possible mechanism in human gastric carcinoma

AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution.Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1,cyclin B1 and p21waf1/cip1.RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901).Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 μg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7%respectively and cell cycles were arrested at the G(2)/Mphase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21waf/cip1 protein expression in a concentration-dependent manner.CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle,with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21waf/cip1 protein in the concentration range of 0-20 μg/mL.

Isolation and characterization of heterotrophic nitrifying bacteria in MBR

The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. Continuous tests via a membrane bioreactor (MBR) were operated under the controlled conditions to proliferate the nitrifiers. Heterotrophic nitrifying bacteria were isolated from the system in which the efficiency of total nitrogen(TN) removal was up to 80%. Since no autotrophic ammonium and nitrite oxidizers could be detected by fluorescence in situ hybridization(FISH), oxidized-N production was unlikely to be catalyzed by autotrophic nitrifiers during the heterotrophic nitrifiers' isolation in this study. The batch test results indicate that the isolated heterotrophic bacteria were able to nitrify. After 3 weeks incubation, the efficiencies of the COD removal by the three isolated bacterial strains B1, B2, and B3 were 52 6%, 71 7%, and 77 7%, respectively. The efficiencies of the TN removal by B1, B2, and B3 were 35 6%, 61 2% and 68 7%, respectively.

LRH-1/hB1F and HNF1 synergistically up-regulate hepatitis B virus gene transcription and DNA replication

Enhancer Ⅱ(ENII)is one of the critical cis-elements in the Hepatitis B Virus(HBV)genome for the hepatic viral gene transcription and DNA replication.The liver-specific activity of ENII is regulated by multiple liver-enriched transcription factors,including LRH-1/hB 1 F,HNF 1,HNF3β,HNF4 and C/EBP.Knowledge on the interplay of these important factors is still limited.In this study,we demonstrate a functional synergism between the orphan nuclear receptor LRH-1/hB 1F and the homeoprotein HNF1 in up-regulating the liver-specific activity of ENII.This synergism is sufficient for initiating the viral gene transcription and DNA replication in non-hepatic cells.We have defined the activation domains in hB 1F and HNF 1 that contribute to the synergism.We further show that hB 1F and HNF1 can interact directly in vitro and have mapped the domains required for this interaction.

Effect of Long-term Intake of Rare Earth in Drinking Water on Trace Elements in Brains of Mice

The mice were fed with water dissolved different level Y 3+ (0, 23.25, 2325.00 mg·L -1 ) for seven months, and the levels of trace elements such as Cu, Zn, Mn, Fe, Mg, Ni and Co in brains of F1 generation mice were then determined by POEMS. The results show that, compared with control, significant decreases in levels of Fe and Ni, increase in level of Co are observed, which suggested that Y 3+ may have an effect on the metabolism and distribution of some trace elements in brain, and then lead to changes of physiological function.

Analysis of SSR in Citrus Sequences from EMBL Database

Abundance of simple sequence repeat (SSR) in Citrus sequences from EMBL database was investigated by usingcomputer program MISA (MIcroSAtellite), which aimed to provide useful information for the development of SSR markers.Among 32 896 sequences of Citrus, 4 987 SSRs were found in 4 167 sequences and the average distance between SSRs wasapproximately 3.5 kb. Mononucleotide repeats (50.6%) were the most abundant repeats. And di-, tri-, tetra-, penta- andhexa-nucleotide repeats were 22.8, 25.2, 1, 0.08, and 0.36%, respectively. The most abundant motif was A/T followed indescending order by AG/CT, AC/GT, AT/TA. AAT/ATT, AAG/CTT, AGC/CGT, ACG/CTG and C/G. They comprised about90% of all microsatellites. Ten primer pairs were designed, and three of them produced clear visible bands among Citrusand its related genera.

The Role of Extracellular Ca^(2+) Influx,Intracellular Ca^(2+) Release and Calm odulin in MouseEgg Fertilization

The effects of various Ca 2+ modifying drugs on moue egg fertilization were studied.Ca 2+ chelator,ethylen glycol bis (2 aminoethyl) tetracetic acid(EGTA),and calmodulin (CaM) antagonist,trifluoperzaine(TFP),inhibited fertilization in a dose dependent manner,whild Ca 2+ channel bolcker,verapamil,did not have any effect.When intracellular Ca 2+ release was blocked by 8 (N,N diethylamino) octy1 3,4, 5 trimethoxybenzonate(TMB 8) or the Ca 2+ oscillations were inhibited by an inhibitor of endoplasmic reticulum Ca 2+ ATPase,thapsigargin,the second polar body emission and pronuclear formation were significantly decreased.In contrast,inhibition of intracellular Ca 2+ release via bolckage of inositol 1,4,5 triphosphate (IP3) production by neomycin or lithium did not affect fertilization.The results sugest that both extracellular influx,intracellular Ca 2+ release and CaM activation are required for normal fertilization.However,extracellular influx through voltage gated Ca 2+ channel and intracellular release induced by IP3 are not the only pathways for producing Ca 2+ transients in moue eggs.

Molecular Cloning and Prokaryotic Expression of Non-Structural Protein NS1 Gene of Porcine Parvovirus

Porcine parvovirus (PPV) is one of the major agents causing swine reproductive failure. NS1 protein is a non-structural protein of PPV and can be used as a reagent for differentiation of vaccinated animals and infected ones. In present study, a recombinant plasmid pET28a/NS1 was constructed by cloning the coding sequence for NS1 of PPV into pET28a, a bacterial expression vector. The NS1 protein was expressed in E. coli BL21(DE3) after induced by IPTG and the recombinant fusion protein was purified with affinity chromatography. Expression amount of NS1 protein was improved by optimizing the inducing parameters. The recombinant NS1 protein is reactive to PPV positive sera in Western blot and ELISA test and therefore can be applicable in differential diagnosis of PPV infections.

Construction of ammonium-tolerant strains of diazotroph associated with rice and its applications

In rice field, especially in the fertilized field the combined nitrogen content is rather high. It is well known that the nitrogen compounds, particularly NH4^+ inhibits the nitrogenase activity- of diazotrophs. So, the enhancement of nitrogen fixation ability of diazotrophs in the presence of ammonia by means of genetic manipulation will be of importance for agricultural use.

酸变性木薯淀粉的制备及其在高水分含量低温热处理的结构研究

在本实验中，我们以酸解法获得有较高结晶度和一定机械强度的木薯变性淀粉，还进一步研究了这些淀粉在高水分含量的情况下，经低温热处理形成的有序分子结构，木薯原淀粉酸解的第一阶段（水解12－96h)，直链淀粉水解速度快，相对结晶度急剧增加，第二阶段（水解192－768h)，几乎所有的直链淀粉都不存在，结晶区部分在地开始降解，最不稳定的结晶区域不再存在。另外，非均性大的结晶区域彼此分开，最后导致吸热曲线变宽，糊化焓可视为双螺旋结构的熔化能力，焓的提高是因为直链淀粉－支链淀粉之间的相互作用，从而在退火过程中导致更多的双螺旋结构或共结晶。

Characterization of the Hemolytic Properties of an Extract from Phaeocystis globosa Scherffel

Phaeocystis globosa Scherffel, an organism that causes harmful algal blooms, is a genus of the family Prymnesiophyta (or Haptophyta) with eurythermal and euryhaline characteristics. P. globosa has been confirmed to produce hemolytic substances, which are a mixture of liposaccharides. In the present study, the hemolytic properties of extract of P. globosa are analyzed further. The effects of temperature, pH, different divalent cations, and membrane lipids on extract-induced hemolysis are discussed, as is the possible hemolytic mechanism. The results of the present study showed that the hemolytic activity of the extract was approximately 127.1 hemolytic units (HU)/L. The hemolytic reaction became fastest and a 50% decrease in absorbance was induced at 30 min at 37 °C, and at pH 7.0; Hg2+ was the strongest inhibitor of the hemolysis compared with the other divalent cations and many membrane lipids, except for phosphatidic acid, inhibited the hemolytic activity to different degrees. These results suggest that the toxin may make pores in the surface of red blood cells and that Hg2+ either combines with the hemolysin or closes the pores, hence inhibiting its further hemolytic reaction. The toxin probably has no specific membrane receptor in the red blood cell membrane.

Effect of Microwave and He-Ne Laser on Enzyme Activity and Biophoton Emission of Isatis indigotica Fort

Abstract: The seed embryos of Isatis indigotica Fort were exposed to He-Ne laser (5.23 mW/mm2, radiated for 5 min) and microwave (1.26 mW/mm2, radiated for 8 s) irradiation to determine the effects of microwave and He-Ne laser pretreatment on enzyme activities, and biophoton emission of cotyledon. Then: (i) changes in the activities of enzymes in I. indigotica cotyledon (such as amylase, transaminase, and proteinase) were measured to investigate the effects of He-Ne laser and microwave pretreatment; and (ii) biophoton emission was measured to determine the speed of cell division and metabolism. Results from these experiments indicated that: (i) the activities of amylase, transaminase, and proteinase of the cotyledon pretreated by He-Ne laser and microwave were significantly increased; and (ii) the intensity of biophoton emission was enhanced significantly by He-Ne laser and microwave irradiation. These changes suggest that He-Ne laser and microwave pretreatment can improve the inner energy of seeds, lead to an enhancement of cotyledon enzymes, and speed up the metabolism of the cell, resulting in significantly increased biophoton emission. Moreover, the mechanism of action of the effects of laser and microwave radiation on the microcalorimetric parameters, enzyme activities, and biophoton emission of seeds is discussed on the basis of the results obtained.

A new way for chemical degradation of plastic by natural volatile constituents of Ledum palustre

A novel phenomenon of degradation ofpolypropylene plastic by volatile constituents of Ledum palustre is reported in this study. The characteristic ofdegradation is described by tensile strength, melting point,and scanning electron micrographs as well as opticalmicrographs. The chemical composition of volatile oil ofLedum palustre is analyzed by gas chrography and massspectrometry. The mechanism of degradation and problemsneeded to be solved are also discussed.