[Cloning and function analysis of promoter of DcCDPK8 from Dendrobium catenatum].

DcCDPK8 involved in abiotic stress such as low temperature and signal transduction of hormones ABA and MeJA,but the transcriptional regulation is still unclear. In order to study the core promoter region of DcCDPK8 gene in Dendrobium catenatum and explore its transcriptional regulation mechanism,the DcCDPK8 gene promoter sequence was cloned by PCR from D. catenatum. Promoter sequence function was studied by fusion of 5 'terminal deletion and GUS gene. The results showed that the promoter sequence of DcCDPK8 gene has a low-temperature responsive element( LTR) between~(-1) 749 bp and-614 bp,two MeJA responsive elements between~(-1) 749 bp and-230 bp,and one ABA responsive elements between-614 bp and-230 bp. Three 5'-end different deletion fragments were constructed to fuse the eukaryotic expression vectors p BI121 with GUS,which were transformed into tobacco leaves. The GUS activity under cold stress treatment was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3. GUS activity under exogenous ABA induction was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3,and GUS activity under exogenous MeJA induction was DcCDPK8-p1>DcCDPK8-p2>DcCDPK8-p3. It is speculated that the ABA response element( ARE) in the promoter sequences of DcCDPK8 is positive regulatory role in response to exogenous ABA,the MeJA cis-acting element plays a negative role in response to exogenous MeJA.

Comparison of common burden tests for genetic association studies of rare variants.

Common burden tests have different statistical performance in genetic association studies of rare variants. Here, we compare the statistical performance of burden tests, such as CMC, WST, SUM and extension methods, using the computer-simulated datasets of rare variants with different parameters of sample sizes, linkage disequilibrium (LD), and different numbers of mixed non-associated variants. The simulation results showed that the type I error for all methods is near 0.05. When the rare variants had the same direction of effect, the higher LD and the less non-associated variants, the higher the power of these method, except the data adaptive SUM test. When the direction was different, the power was significantly reduced for all methods. The methods that consider the direction yielded larger statistical power than those methods without considering the effect direction, except the strong LD condition. And the larger the sample size, the larger the power. The statistical performance of burden tests is affected by a variety of factors, including the sample size, effect direction of variants, non-associated variants, and LD. Therefore, when choosing the method and setting the collection unit and weight, the prior biological information of genetic variation should be integrated to improve study efficiency.

Serum Thyroglobulin-A Sensitive Biomarker of Iodine Nutrition Status and Affected by Thyroid Abnormalities and Disease in Adult Populations.

OBJECTIVE: To evaluate the usefulness of the thyroglobulin (Tg) level in adults as a nutritional biomarker of iodine status and to identify the factors related to the serum Tg level. METHODS: A cross-sectional study was conducted in adult populations of areas differing in iodine nutrition from three provinces (Autonomous Region) in China. Serum levels of thyroid hormones and Tg as well as thyroid autoantibodies were measured. The thyroid volume and nodule were measured by ultrasound. A multivariate linear regression analysis was used to assess iodine intake and other indeterminate factors associated with the serum Tg level. RESULTS: A total of 573 adults were recruited for this study. The serum Tg levels differed significantly among the three groups (22.27 µg/L, 9.73 µg/L and 15.77 µg/L in the excess, more-than-adequate, and deficient groups, respectively). The results of multivariate linear regression analysis indicate that excess and deficient iodine intake, goiter, thyroid nodule, hypothyroidism are significantly related with higher Tg level, and TgAb positivity is significantly related with lower serum Tg. CONCLUSION: The serum Tg level reflects abnormal thyroid function and is a sensitive functional biomarker of iodine nutrition status.

[Cloning and analysis of reverse transcriptase(RT) of Ty1-copia retrotransposons in Dendrobium officinale].

Using universal primer Ty1-copia retrotransposon RT,43 Ty1-copia like retrotransposon RT with high heterogeneity, stop codon mutation and frameshift mutation were amplified by PCR from genomic DNA of Zhejiang Lin'an (C15) and Yunnan Guangnan (A39) of Dendrobium officinale. The length of these sequences varied from 260 to 266 bp, and was rich in AT and consistency ranged from 47.1% to 97.7%. Different c/s-acting regulatory elements induced by low temperature, heat, light, all kinds of plant growth regulating substances and the starting transcription signals, corresponding to CAAT box, TATA box conserved sequences and some other regulatory elements. When being translated into amino acids, ten sequences presented stop codon mutation, five sequences presented frameshift mutation, and thirty-seven sequences presented conserved sequence "SLYGKQ" mutation. Six categories were identified through phylogenic analysis after alignment analyses of their amino acid sequences, and with other plants (eg. Triticum aestivum, Eleocharis quinqueflora) having high homology, which indicated that horizontal transmission of retrotransposon occurred among the plants in the past.

[Effect of ABA on transcriptionally active Ty1-copia retrotransposons in Dendrobium officinale].

Using universal primer Tyl-copia retrotransposon RT, the conserved reverse transcriptase domain of about 260 bp was amplified by RT-PCR from the Dendrobium officinale which induced by 100 micromol x L(-1) abscisic acid (ABA), indicating these retrotransposons activated by 100 micromol x L(-1) ABA. The amplicons were recovered and cloned,then sequenced and analyzed by related bioinformatics software. Forty-two Ty1-copia like retrotransposon RT transcriptionally activated were obtained with high heterogeneity. The length of these sequences varied from 247 to 266 bp, and was rich in AT and homology ranged from 46.3% to 98.9%. The same to Ty1-copia like retrotransposon RT of genome, different c/s-acting regulatory elements induced by stress conditions and the starting transcription signals, corresponding to CAAT box, TATA box conserved sequences and some other regulatory elements. The c/s-acting regulatory elements induced by stress conditions of reverse transcriptase transcriptionally activated of Tyl-copia retrotransposons were significantly increased than that of Ty1-copia like retrotransposon RT of genome. When being translated into amino acids, fifteen sequences presented stop codon mutation, nineteen sequences presented frameshift mutation, and all sequences presented conserved sequence "SLYGKQ" mutation. Five categories were identified through phylogenic analysis after alignment analyses of their amino acid sequences, and with Ty1-copia like retrotransposon RT of genome having low homology, which indicated that reverse transcriptase transcriptionally activated of Ty1-copia retrotransposons which induced by ABA had Significantly differences with Ty1-copia like retrotransposon RT of genome.

The chiral bioconversion and preclinical pharmacokinetic analysis of (R)-(+)-rabeprazole in beagle dogs by HPLC and HPLC-MS/MS.

In order to accurately investigate the preclinical pharmacokinetics of (R)-(+)-rabeprazole sodium injection, a reliable high-performance liquid chromatography (HPLC) method was developed using a Chiral-AGP column to prove that there is no chiral bioconversion of (R)-(+)-rabeprazole to (S)-(-)-rabeprazole in beagle dogs after single intravenous administration of (R)-(+)-rabeprazole sodium injection. An HPLC-tandem mass spectrometry (HPLC-MS/MS) method for analysis of (R)-(+)-rabeprazole was developed and validated, and used to acquire the pharmacokinetic parameters in beagle dogs. (R)-(+)-Rabeprazole and internal standard omeprazole were extracted from plasma samples by protein precipitation and separated on a C18 column using methanol-5 mm ammonium acetate as mobile phase. Detection was performed using a turbo-spray ionization source and mass spectrometric positive multi-reaction monitoring mode. The linear relationship was achieved in the range from 2.5 to 5000 ng/mL. The method also afforded satisfactory results in terms of sensitivity, specificity, precision, accuracy and recovery as well as the stability of the analyte under various conditions, and was successfully applied to a preclinical pharmacokinetic study in beagle dogs after single intravenous administrations of (R)-(+)-rabeprazole sodium injection at 0.33, 2 and 6 mg/kg.

[SCoT differential expression of cold resistance related genes in Dendrobium officinale under low temperature stress].

In order to study the molecule mechanism of the differential expression in Dendrobium officinale under low temperature, the high cold resistance germplasms were used for constructing the RNA pools. SCoT markers were used to analyze the different cDNA pools transcribed from the RNA pools. 11 transcripts derived fragments from 500 cDNA amplified bands were amplified by 64 primers, and were sorted out, cloned, sequenced and analyzed. The results showed that cDNA pools with SCoT markers could be used for differential display in D. officinale under low temperature stress. Sequence analysis indicated that the transcripts derived fragments were significantly homologous in nucleotide sequence with membrane-associated proteins, osmotic regulation protein, CBF transcriptional factor, resistance protein. One left gene segments functions were still unknown, which may be related to the cold resistant gene expression in D. officinale.

Extract of Ginkgo biloba leaves attenuates neurotoxic damages in rats and SH-SY5Y cells exposed to a high level of fluoride.

BACKGROUND: Potential protection against the neurotoxic damages of high levels of fluoride on rats and SH-SY5Y cells by extract of Ginkgo biloba leaves, as well as underlying mechanisms, were examined. METHODS: The rats were divided randomly into 4 groups, i.e., control, treatment with the extract (100 mg/kg body weight, gavage once daily), treatment with fluoride (50 ppm F- in drinking water) and combined treatment with both; SH-SY5Y cells exposed to fluoride and fluoride in combination with the extract or 4-Amino-1,8-naphthalimide (4-ANI), an inhibitor of poly (ADP-ribose) polymerase-1 (PARP-1). Spatial learning and memory in the rats were assessed employing Morris water maze test; the contents of fluoride in brains and urine by fluoride ion-selective electrode; cytotoxicity of fluoride was by CCK-8 kit; the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the content of malondialdehyde (MDA) by appropriate kits; the level of 8-hydroxydeoxyguanosine (8-OHdG) was by ELISA; the content of ROS and frequency of apoptosis by flow cytometry; the expressions of phospho-histone H2A.X(Ser139), PARP-1, poly (ADP-ribose) (PAR) and Sirtuin-1 (SIRT1) by Western blotting or immunofluorescence. RESULTS: The rats with prolong treatment of fluoride exhibited dental fluorosis, the increased contents of fluoride in brains and urine and the declined ability of learning and memory. In the hippocampus of the rats and SH-SY5Y cells exposed to fluoride, the levels of ROS, MDA, apoptosis, 8-OHdG and the protein expressions of histone H2A.X(Ser139), PARP-1 and PAR were all elevated; the activities of SOD and GSH-Px and the protein expression of SIRT1 reduced. Interestingly, the treatment of Ginkgo biloba extract attenuated these neurotoxic effects on rats and SH-SY5Y cells exposed to fluoride and the treatment of 4-ANI produced a neuroprotective effect against fluoride exposure. CONCLUSION: Ginkgo biloba extract attenuated neurotoxic damages induced by fluoride exposure to rats and SH-SY5Y cells and the underlying mechanism might involve the inhibition of PARP-1 and the promotion of SIRT1.

[Association between beta3-adrenergic receptor and oxidative stress in chronic heart failure rats].

OBJECTIVE: To investigate the association between beta(3)-adrenergic receptor (beta(3)-AR) and oxidative stress in isoproterenol (ISO)-induced chronic heart failure (HF) rats. METHODS: Seven weight-matched normal adult rats (control), 18 ISO induced heart failure rats and 21 ISO induced heart failure rats treated with specific beta(3)-AR inhibitor, SR59230A for 6 weeks were included in this study. Echocardiography was performed at the end of the study and the myocardial levels of total superoxide dismutase (T-SOD) and lipid peroxidation (LPO) were measured by colorimetry, myocardial expression of beta(3)-AR was detected by reverse transcription-polymerase chain reaction (RT-PCR). RESULT: Compared with control group, the cardiac function was significantly reduced and myocardial beta(3)-AR mRNA expression was significantly increased, LPO level was also significantly enhanced while T-SOD level was significantly reduced in ISO group and these changes could be significantly attenuated by treatment with SR59230A. CONCLUSION: Our results showed that myocardial upregulation of beta(3)-AR is associated with increased oxidative stress in this model and beta(3)-AR inhibitor may be a new therapeutic agent for heart failure treatment.

High birth weight and its interaction with physical activity influence the risk of obesity in early school-aged children.

BACKGROUND: High birth weight (HBW) is associated with childhood obesity, but with inconsistent results. This study investigated the relationship between HBW and childhood obesity, and further explored the interaction of HBW with behavioral and socio-economic determinants of obesity. METHODS: This cross-sectional study enrolled 1906 grade-two children of Guangzhou, China, from June to November, 2016. Overweight/obesity corresponded to a body mass index higher than the sex-age-specific criteria. Abdominal obesity was assessed using the sex-specific waist-height ratio cutoffs. The association of HBW with obesity was evaluated in multivariable logistic regression model. The relative excess risk due to interaction (RERI) and the attributable proportion of interaction (AP) indices were used to measure additive interaction, while applying the interaction of OR index for multiplicative interaction assessment. RESULTS: Children with HBW had an increased risk of overweight/obesity [odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.56-3.76] compared with those without HBW. Significant additive interaction of HBW with physical activity was found for overweight/obesity [relative excess risk due to interaction (RERI) = 2.69, 95% CI = 0.62-4.75; attributable proportion of interaction (AP) = 0.72, 95% CI = 0.42-1.02]. The HBW children with insufficient activity had higher odds of overweight/obesity compared to the non-HBW children with sufficient activity (OR = 3.75, 95% CI = 2.06-6.83). In addition, we identified a significant interaction of HBW with household income for abdominal obesity (RERI = 1.20, 95% CI = 0.02-2.37; AP = 0.76, 95% CI = 0.16-1.36). CONCLUSIONS: HBW confers an increased risk for childhood overweight/obesity. Physical activity attenuates the effect of HBW on overweight/obesity, and HBW possibly synergistically interacts with high household income to promote abdominal obesity in childhood.

[Study on inhibitory effects of c9, t11-conjugated linoleic acid on migration of human gastric carcinoma cell line via cyclooxygenase-2 pathway].

OBJECTIVE: To study the inhibitory effects of c9, t11-conjugated linoleic acid (c9, t11-CLA) on migration of human gastric carcinoma cell line (SGC-7901) via cyclooxygenase-2 (COX-2) pathway. METHODS: After inhibiting COX-2 activity by 100 micromol/L COX-2 inhibitor NS-398 in SGC-7901 cell, we treated SGC-7901 cells with c9, t11-CLA at a concentration of 200,100, 50, 25 micromol/L for 24 h, respectively. Using reconstituted basement membrane invasion, adhesion, chemotaxis assays, we detected the effect of c9, t11-CLA and COX-2 on the cell migration. RESULTS: Compared to NS-398 group, 200, 100 micromol/L c9, t11-CLA significantly suppressed SGC-7901 cells invading into the reconstituted basement membrane (F = 14.309, P = 0.000; F = 19.005, P = 0.000). 200 micromol/L c9, t11-CLA significantly inhibited SGC-7901 cells adhering to laminin, fibronectin and Matrigel (F = 3.063, P = 0.021; F = 6.692, P = 0.001; F = 11.999, P = 0.000). The chemotaxis of SGC-7901 cells and inhibitory frequency were significantly decreased in the 200 micromol/L c9, t11-CLA group (F = 1.380, P = 0.276). CONCLUSION: c9, t11-CLA inhibits invasion, adhesion and chemotaxis of SGC-7901 cells, and the COX-2 plays an important role in the process. [ Key words]

ClC-7/Ostm1 contribute to the ability of tea polyphenols to maintain bone homeostasis in C57BL/6 mice, protecting against fluorosis.

Epidemiological investigations indicate that certain ingredients in tea bricks can antagonize the adverse effects of fluoride. Tea polyphenols (TPs), the most bioactive ingredient in tea bricks, have been demonstrated to be potent bone-supporting agents. ClC­7 is known to be crucial for osteoclast (OC) bone resorption. Thus, in this study, we investigated the potential protective effects of TPs against fluorosis using a mouse model and explored the underlying mechanisms with particular focus on ClC­7. A total of 40, healthy, 3­week­old male C57BL/6 mice were randomly divided into 4 groups (n=10/group) by weight as follows: distilled water (control group), 100 mg/l fluoridated water (F group), water containing 10 g/l TPs (TP group) and water containing 100 mg/l fluoride and 10 g/l TPs (F + TP group). After 15 weeks, and after the mice were sacrificed, the long bones were removed and bone marrow-derived macrophages were cultured ex vivo in order to perform several experiments. OCs were identified and counted by tartrate­resistant acid phosphatase (TRAP) staining. The consumption of fluoride resulted in severe fluorosis and in an impaired OC function [impaired bone resorption, and a low mRNA expression of nuclear factor of activated T-cells 1 (NFATc1), ATPase H+ transporting V0 subunit D2 (ATP6v0d2) and osteopetrosis­associated transmembrane protein 1 (Ostm1)]. In the F + TP group, fluorosis was attenuated and OC function was restored, but not the high bone fluoride content. Compared with the F group, mature OCs in the F + TP group expressed higher mRNA levels of ClC­7 and Ostm1; the transportation and retaining of Cl­ was improved, as shown by the fluorescence intensity experiment. On the whole, our findings indicate that TPs mitigate fluorosis in C57BL/6 mice by regulating OC bone resorption. Fluoride inhibits OC resorption by inhibiting ClC­7 and Ostm1, whereas TPs attenuate this inhibitory effect of fluoride.

[Influence of methane and trichloroethylene domestication on bacterial community structure in landfill cover soil.] / 甲烷及三氯乙烯驯化对垃圾填埋场覆盖土细菌群落结构的影响.

The biological oxidation capacity and change of microbial community structure of typical landfill cover soil cultured in situ by methane and trichloroethylene (TCE) were studied. The rates of CH4 oxidation and TCE degradation were 0.20-0.87 Μmol·g-1 soil·h-1 and 0.009-0.013 mg·L-1·h-1 among these landfill cover soils, respectively. The activity of CH4 oxidation in Shandong landfill cover soil was higher than that in landfill cover soils sampled from Guangdong, Shanghai and Chongqing. The α-diversity and microbial community structure before and after co-metabolism degradation were then investigated in all landfill cover soils by Illumina MiSeq sequencing. The results indicated that bacterial Operational Taxonomic Units (OTUs) were assigned to 39 phyla, 85 classes and 562 genera in all the commented OTUs clustering. The dominant bacterial populations were Proteobacteria, Bacteroidetes, Chloroflexi and Acidobacteria and the sum of the proportion was over 77.4% in all landfill cover soils. In addition, total percent of γ-Protebacteria, ß--Protebacteria, α-Proteobacteria, Actinobacteria and Acidobacteria was over 26.5%. Specifically, the relative abundances of Methylophilaceae_uncultured, Anaerolineaceae_uncultured, Arthrobacter and Pseudomonas increased obviously after acclimated by TCE. These results suggested that there were co-metabolism degradation with non-methane compounds and aerobic assimilation of TCE besides the widely-agreed co-metabolism degradation by methanotrophs.

Prolactin rs1341239 T allele may have protective role against the brick tea type skeletal fluorosis.

OBJECTIVE: Prolactin (PRL) has been reported to be associated with increased bone turnover, and increased bone turnover is also a feature of skeletal fluorosis (SF). Autocrine/paracrine production of PRL is regulated by the extrapituitary promoter and a polymorphism in the extrapituitary PRL promoter at -1149 (rs1341239) is associated with disturbances of bone metabolism in other diseases. Here, we have investigated the possibility that the rs1341239 polymorphism is associated with SF, which results from the consumption of brick tea. DESIGN: We conducted a cross-sectional study in Sinkiang, Qinghai, Inner Mongolia in China. Demography survey questionnaires were completed and physical examination and X-ray diagnoses were used to diagnose SF. Brick tea water fluoride intake (IF) and urinary fluoride (UF) were tested by an F-ion selective electrode method. A Sequenom MassARRAY system was used to determine PRL gene polymorphisms. RESULTS: Subjects who were younger than 45 years of age and carried the T allele had a significantly decreased risk of SF [OR = 0.279 (95%CI, 0.094-0.824)] compared to those carrying the homozygous G allele. This phenomenon was only observed in Kazakh subjects [OR = 0.127 (95%CI, 0.025-0.646)]. Kazakh females who carried T alleles has a decreased risk of SF [OR = 0.410 (95%CI, 0.199-0.847)]. For Kazakh subjects which IF is less than 3.5 mg/d, a decreased risk of SF was observed among the participants who carried T alleles [OR = 0.118 (95%CI, 0.029-0.472)]. Overall, subjects with 1.6-3.2 mg/L UF and carried T alleles had a significantly decreased risk of SF [OR = 0.476 (95%CI, 0.237-0.955)] compared to homozygous G allele carriers. This phenomenon was only observed in Kazakh subjects [OR = 0.324 (95%CI, 0.114-0.923)]. CONCLUSIONS: Our results suggested that the PRL rs1341239 T allele decreases the risk of brick tea SF.

[Studies on the cytological characters of the interspecific hybrid F1 among the cultivated species in Gossypium and their genetic relationship].

Interspescific hybridization among four cultivated species in Gossypium (G. herbaceum, G. arboreum, G. hirsutum and G. barbadense) were carried out to produce dispecific hybrids F1, (G. arboreum x G. herbaceum) F1 and (G. hirsutum x G. barbadense) F1, and quadrispecific hybrid F1, which was produced by crossed the chromosome doubled (G. arboreum x G. herbaceum) F1 with (G. hirsutum x G. barbadense) F1. In order to study the evolution relationship among the four cultivated species in Gossypium, the characteristic of chromosome behavior during the meiosis and pollen viability in those interspecific hybrids F1 were studied in this paper. The results showed that the diploid interspecific hybrid, (G. arboreum x G. herbaceum) F1, had a four-chromosome-ring, the chromosome configuration was 2n = 26 = 11 II + 1 IV. And the normal pollen percent was 50.71%, which showed the character of typical gamete semi-sterility, and approved that there was a chromosome translocation between the two diploid cotton species, G. arboreum and G. herbaceum. For the allotetraploid species interspecific hybrid F1, (G. hirsutum x G. barbadense) F1, most of the chromosomes at metaphase I could be paired into bivalents, with a few number of univalents, trivalents, and quardrivalents. The chromosome configuration was 2n = 52 = 0.78 I +22.24 II +0.94 III +0.98 IV, with a normal pollen rate of 54. 84%. The experiment showed that there were a few chromosome translocation or chromosome inversion between the two allotetraploid cotton species, G. hirsutum and G. barbadenses. The meiosis of the quardrispecific hybrid F1 was abnormal, and the loss of chromosomes was common. Most of the chromosomes could not synapse at metaphase I, which led to many univalents and some multivalents. The chromosome configuration of the quardrispecific hybrid F1 was 2n = 52 = 5.45 I +14.41 II +2.44 III +1.59 IV +0.63 V +0.15 VI, and the normal pollen rate was 6.87%, which showed that the relationship of four cultivated cotton species was relatively closed. It is possible to produce a new germplasm with the good characters of the four cultivated species through genetic recombination.

[Effects of conjugated linoleic acid on the expression of critical enzymes of linoleic acid metabolism in tumor cell].

OBJECTIVES: To study the effects of c9,t11-conjugated linoleic acid (c9,t11-CLA) on critical enzymes of linoleic acid metabolism in stomach granular cell (SGC-7901). METHODS: SGC-7901 was treated with c9,t11-CLA by 200, 100, 50 or 25 micromol/L for 24 hours. The effects of c9,t11-CLA on the cell proliferation was measured by monotetrazolium and the expression of Delta6-desaturase, Delta5-desaturase, COX-1, COX-2, 5-LOX mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: At a concentration of 200, 100, 50, or 25 micromol/L, c9,t11-CLA suppressed the proliferation of SGC-7901 by 54.3%, 20.5%, 10.5% and 2.93%. The c9,t11-CLA might decrease the expression of COX-2 mRNA, and increase the expression of Delta6-desaturase and COX-1 in SGC-7901, but might not affect Delta5-desaturase and 5-LOX. CONCLUSION: The effects of c9,t11-CLA on the COX and Delta6-desaturase might play an important role in mediating the ability of c9,t11-CLA as to inhibiting the proliferation of tumor cells, and the anti-cancer activity by c9,t11-CLA might be associated with the linoleic acid metabolism.

[Depth Profiles of Methane Oxidation Kinetics and the Related Methanotrophic Community in a Simulated Landfill Cover].

Simulated landfill cover with real time online monitoring system was developed using cover soils. Then the system started and the concentrations of bio-gas in various depths were continuously monitored, and it was found that the system ran continually and stably after 2-3 h when methane flux changed. After that, the relationship between regularity of methane oxidation and methane flux in landfill cover was analyzed. The results indicated that concentration of oxygen decreased with increasing methane flux when the depth was deeper than 20 cm, and no obvious correlation between oxygen concentration in landfill cover surface and methane flux, however, methane oxidation rate showed positive correlation with methane flux in various depths (range of R2 was 0.851-0.999). Kinetics of CH4 oxidation in landfill cover was fitted by CH4 -O2 dual-substrate model (range of R2 was 0.902-0.955), the half-saturation constant K(m) increasing with depth was 0.157-0.729 in dynamic condition. Finally, methanotrophs community structure in original cover soil sample and that in simulated landfill cover were investigated by high-throughout sequencing technology, and the statistics indicated that the abundance and species of methanotrophs in simulated landfill cover significantly increased compared with those in original cover soil sample, and type I methanotrophs including Methylobacter and Methylophilaceae and type II methanotrophs Methylocystis were dominant species.

Effects of c9,t11-conjugated linoleic acid on adhesion of human gastric carcinoma cell line SGC-7901.

AIM: To investigate the effect of c9,t11-conjugated linoleic acid (c9,t11-CLA) on the adhesion of human gastric carcinoma cell line (SGC-7901). METHODS: SGC-7901 cells were at first treated with different concentrations (25, 50, 100, 200 micromol/L) of c9,t11-CLA and 1 mL/L ethanol (as a negative control) for 24 h. Using adhesion assay and Western blot, we investigated the ability of SGC-7901 cells to adhere to intracellular matrix and examined the expression of E-cadherin (ECD), alpha-catenin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in these cells. RESULTS: The attachment rate to laminin of SGC-7901 cells treated with different concentrations of c9,t11-CLA (0, 25, 50, 100, and 200 micromol/L) was 100.0+/-3.3, 95.7+/-4.0, 89.2+/-4.6, 87.9+/-6.1, and 65.9+/-5.8, respectively. The attachment rate to fibronectin was 100.0+/-4.7, 96.8+/-3.8, 94.5+/-4.1, 76.5+/-4.3, and 61.8+/-4.8, respectively. The attachment rate to Matrigel was 99.9+/-6.6, 91.4+/-6.8, 85.5+/-7.4, 79.3+/-5.6, and 69.6+/-5.1, respectively. Besides, c9,t11-CLA could increase the level of ECD and alpha-catenin, and decrease the level of ICAM-1 and VCAM-1 in SGC-7901 cells. CONCLUSION: c9,t11-CLA can reduce the adhesion of human gastric carcinoma cells to laminin, fibronectin and Matrigel. c9,t11-CLA can increase the level of ECD and alpha-catenin, and decrease the level of ICAM-1 and VCAM-1 in human gastric carcinoma cells.

Inhibitory effects of c9, t11-conjugated linoleic acid on invasion of human gastric carcinoma cell line SGC-7901.

AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9, t11-CLA) on the invasion of human gastric carcinoma cell line and its possible mechanism of preventing metastasis. METHODS: Using reconstituted basement membrane invasion, chemotaxis, adhesion, PAGE substrate zymography and RT-PCR assays, we analyzed the abilities of invasion, direct migration, adhesion of intracellular matrix, as well as the activity of type IV collagenase and expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 mRNA in SGC-7901 cells which were treated with gradually increased concentrations (25, 50, 100 and 200 micromol/L) of c9, t11-CLA for 24 h. RESULTS: At the concentrations of 200 micromol/L, 100 micromol/L and 50 micromol/L, c9,t11-CLA suppressed the invasion of SGC-7901 cells into the reconstituted basement membrane by 53.7 %, 40.9 % and 29.3 %, respectively, in comparison with the negative control. Only in the 200 micromol/L c9,t11-CLA group, the chemotaxis of SGC-7901 cells was inhibited by 16.0 % in comparison with the negative control. C9,t11-CLA also could inhibit the adhesion of SGC-7901 cells to laminin, fibronectin and Matrigel, increase the expression of TIMP-1 and TIMP-2 mRNA, and reduce type IV collagenase activities in the serum-free medium supernatant of SGC-7901 cells. CONCLUSION: c9,t11-CLA can inhibit the invasion of SGC-7901 cells at multiple procedures in tumor metastasis cascade, which may be associated with the induction of TIMP-1 and TIMP-2 mRNA expression.

Protective effect of M3 receptor on H2O2 -induced apoptosis of rat myocardial cells in vitro.

AIM: To observe the effect of activation of M3 receptor on H2O2 induced apoptosis in cultured rat myocytes and to investigate its possible mechanisms. METHODS: Isolated neonatal cardiomyocytes were cultured. Morphologic changes were observed by microscopy. The apoptosis in cardiomyocyte was detected by terminal deoxynucleotide transferase directed d-UTP nick and end labeling (TUNEL) assay. The expression of apoptosis-related protein in Bcl-2 and Fas was measured by immunohistochemistry assay. [Ca2+]i in single cardiomyocyte loaded with Fluo 3-AM was measured by confocal microscope. RESULTS: H2O2-mediated myocyte apoptosis was attenuated by M3 receptor agonist choline (10 mmol x L(-1)). Pretreatment of cardiac myocytes with choline also increased Bcl-2, decreased Fas expression, and inhibited the increase in FI value of [Ca2+]i in H2O2-stimulated cardiac myocytes. However, blockade of M3 receptor by 4DAMP (10 nmol x L(-1)) completely inhibited the effects of choline on H2O2-stimulated cardiac myocytes. CONCLUSION: Activation of M3 receptor showed protective effect on H2O2-induced apoptosis in cultured rat myocytes and this effect might be related to modulating the expression of some genes including Bcl-2 and Fas as well as the downregulation of [Ca2+]i.