In physiological property and growing environment aspects, there are some similarities between Acidthiobacillus ferrooxidans(ATF) and magnetotactic bacteria. ATF shows magnetotacxis under the microscope. The magnetosome can be extracted from ATF by using the extracting method of magnetosome from magnetotactic bacteria. The membrane of ATF was crushed by ultrasonic wave and the magnetosomes in the ATF which mainly contains Fe through chemical detection were attracted by using magnetite. After purifing with sucrose density gradient centrifugation and washing by PBS, the magnetosomes can be seen clearly through a transmission electron microscope. The results indicate there are a small amount of intracellular magnetosomes which made the ATF be magnetotactic under the applied magnetic field. It is the first time to find that ATF was magnetotactic. The magnetotaxis of ATF can be utilized and isolated by the magnetotactic properties to gain the high-performance ATF strains of mineral leaching, which have high activity and different magnetism.

Objective: To study the effects of extremely low frequency (ELF) magnetic field with fixed parameters on human liver cancer cells (SK-HEP-1) at different aspects. Methods: SK-HEP-1 cells were exposed to 50Hz, 20mT magnetic field during the whole culture process, and then proliferation activity, growth kinetics, metabolic profile and cell cycle were analyzed. Results: 50Hz, 20mT magnetic field inhibits the growth and metabolism of SK-HEP-1 cells, and hampers their mitotic division. Conclusion: 50Hz, 20mT magnetic field could be a potential therapy in the treatment of human malignant tumors.

Microsatellite instability(MSI)was defined according to the frequency of positive findings in a panel of MSI markers.High frequency MSI(MSI-H)was the phenotype in which repeat sequences were extraordinarily unstable, and was considered to be the bona fide phenotype of DNA mismatch repair defection. However base substitutions in some well studied oncogenes or tumor suppressors were reported to be uncommon in MSI-H tumors. To explore this obvious contradiction, the relationship between MSI and KRAS gene mutations were studied in a panel of 76 human colorectal carcinomas, the whole exon of MLH1 and MSH2 were sequenced for MSI-H tumors. KRAS gene mutation was confirmed by similar frequencies in tumors of different MSI status. Intriguingly, all of the KRAS mutant MSI-H tumors harbored sequence alterations in MLH1gene, which was a key player in DNA mismatch repair system. This implied that in MSI-H tumors carrying MMR mutations, KRAS mutation were frequently and almost exclusively occurred. Furthermore, these MMR mutants were uniformly carrying a unique modification + jumping type MSI, which was different to MSI-H tumors without MLH1 or MSH2 gene mutations. This study shaded lights on the heterogeneity of MSI-H tumors, and implied the connection between modification type MSI and DNA mismatch defection.

Cloning of differentially expressed genes is one of the hottest topics in biology.It is very important in cloning genes correlated with phenotype and diseases at molecular level.Here we utilized a simple and rapid PCR-based protocol to detect and isolate cDNA fragments from differentially expressed genes of IL-6-induccd and IL-6-uninduced U937 cells in tWO easy steps.To generate cDNAs from most mRNAs,the first step was reverse transcription using three fully degenerated 6-mer oligonucleotides as primers.The second step was PGR amplification of internal regions of the cDNAs with two or three longer primers with arbitrary but defined sequences.The PCR amplification was repeated on the same cDNA templates(first step) with different sets of primers.DNA fragments were easily displayed by 2% agarose gel electrophoresis and then the differential recovered fragments were used directly in cloning,sequencing,and RNA reverse Northern blot analysis.In this study,seven differential ESTs are obtained;two Sequences not found in GenBank,are novel ESTs.They were proved to be differentially expressed genes related with IL-6 effect by reverse Northern hybridization.

Objective: To investigate the applied feasibility of scaffold with modified PLA (Polymer of lactic acid) in tissue engineering. Methods:First, we adopted salting-in method to prepare porous foam scaffold. Then, we reconstructed tissue engineering skin by epidermal cells and fibroblasts combined with modified PLA. On the 14th day of cell culturing in vitro, we was a control. Results:The arfificial skin is composed of epidermis and dermis and similar to natural skin in appearance. The skin consists of fibroblasts and keratinocytes, which are in various proliferation and differentiation stages. Fibroblasts and keratinocytes distribute on the surface of polymer of lactic acid (PLA) and the number of fibroblast and keratinocyte increase. Conclusion:Dialdehyde starches (DAS) not only improve the function of PLA but also have good effects on cells. Moreover, it does not affect the growth and the metabolism of the cells. So it is feasible to use modified scaffold to construct tissue engineering skin.

This paper, from the aspects of neuroendocrine, emotion, learning etc, analyzed comprehensively the characteristics of the influence of prenatal stress (PS) on offspring, including intensity of PS, timing of exposure and individual differences. Despite the variety in methodology, most studies on it indicate that the prenatal stressful events lead to offspring's increased plasma glucocorticoid (GC) level, more depressed-related behaviors and impaired learning abilities. Although mechanism of prenatal stress is still unclear, most studies show that it is concerned with hypothalamio-pituitary-adneral (HPA) axis,dopaminergic (DA-ergic) system, neuropeptide Y (NPY)and serotoninergic (5-HT ergic) system. Moreover, further studies are proposed to pay more attention to the relationship and interaction of various related substances.

Covellite oxidation was evaluated with two acidophilic thiobacilli that are important in bioleaching processes.The experiments were carried out in shake flasks in the absence and presence of 4 g/L Fe2+ (as ferrous sulphate) at pH 2.0, 150 rpm and 35 ℃. The tests showed that the copper extraction by the Acidithiobacillus ferrooxidans culture was nearly the same as that by the mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus. On the other hand, additional iron clearly improved Cu leaching.

Objective: To study the effects of glycosaminoglycan from scallop skirt (SS-GAG) on the expression of vascular endothelial growth factor (VEGF) and the mechanism of anti-atherosclerosis action of SS-GAG. Methods: U937 cells were incubated with 80mg/L oxidized low density lipoprotein (ox-LDL) for 48h to establish a macrophage-derived foam cell model. In addition, U937 cells were divided into 6 groups: ①control group; ②ox-LDL group; ③ox-LDL+200mg/L SS-GAG group; ④ox-LDL+400 mg/L SS-GAG group; ⑤ox-LDL+800 mg/L SS-GAG group; ⑥ox-LDL +Heparin 100 mg/L group.After 48h's incubation, the concentration of VEGF in the medium was determined by ELISA. Results: The expression of VEGF in U937 foam cells was obviously higher than that of the control group. After treatment with heparin (100 mg/L) and SS-GAG of different concentrations (200mg/L, 400 mg/L, 800 mg/L), the expression of VEGF decreased obviously, especially in the ox-LDL+800 mg/L SS-GAG group (P＜0.01). Conclusion: The antiatherogenic effect of SS-GAG is probably due to its ability to inhibit VEGF expression.

Background & Objective:Background &Objective: The class Ⅰ Alcohol Dehydrogenases (ADH) play a key role in hepatic alcohol catabolism. Human ADH is encoded by at least seven genes, and three class Ⅰ ADH genes-ADH1, ADH2 and ADH3, which encode the α, β, and γ subunit respectively, had been isolated and mapped on chromosome 4q21-q25. This experiment tends to clone the human class Ⅰ ADH and investigate its role in the hepatic alcohol catabolism. Methods: A pair of primers were designed and the full-length cDNAs encoding human Class Ⅰ ADH were cloned at one time. Class Ⅰ ADH cDNAs were amplified with RT-PCR from total RNA extracted from fetal human liver and kidney, and cloned into pGEM-T vector. To identify cDNA segments, a pair of differential primers was designed. By using them, a portion of the ADHs which encodes the segment from -4 to 296 was cloned. These cDNA segments then were detected directly when being digested with Kpn Ⅰ and Pst Ⅰ, respectively. Then all the full-length cDNAs were subcloned in the plasmid pTYB11 and expressed in E. Coli. Stably. Alcohol Dehydrogenase activity of catalyzing alcohol were monitored at 340 nm. Results: Here we had successfully the human class Ⅰ ADH cloned and the full-length cDNAs expressed in E.col.I stably. The relative activity of recombinant enzymes metabolizing ethanol was 0.81 ～1.31 U/mg,0.09 ～0.15 U/mg and 0.76～1.11 U/mg, respectively. Conclusions: In the paper, the full-length cDNAs encoding human class Ⅰ AD H were successfully cloned and expressed and the recombinant enzymes showed the activities similar to the ones isolated from liver.

Objective: To investigate the predictive value of serum E2 in early diagnosis of pregnancy through IVF-ET(in vitro fertilization-embryo transfer). Methods: Sixty-two patients (75 cycles involved) undergoing IVF-ET cycles, whose infertility was attributed to uterine tube or male factors, were enrolled. Luteal phase serum E2 was detected every other day after extraction of oocytes with micro-particle enzyme immunoassay. Results: The level of serum E2 declined progressively after extraction of oocytes in both pregnant and non-pregnant cycles, while it showed no significant difference on 2, 4, 6, 8 days after extraction of oocytes. In pregnant cycles following IVF-ET, serum E2 achieved the nadir on day 10 and then increased gradually. The differences of serum E2 levels in pregnant and non-pregnant cycles were detectable from day 10 after extraction of oocytes (816.4+ 537.6 vs. 189.5±69.3 pg/ml) (P＜0.05). In non-pregnant cycles, E2 on day 10 was significantly lower than that on day 8 ( 189.5+ 69.3 vs. 989.2+581.5 pg/ml) (P＜0.05). Conclusions: We concluded that the level of E2 on day 8 and 10 consecutively after extraction of oocytes may have predictive value in diagnosing early pregnancy. Ascension of serum E2 level of pregnant patients on day 10 forebodes the success of pregnancy, or else the failure of pregnancy.