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991.
中国希瓦氏菌D14^T的厌氧腐殖质呼吸 总被引:1,自引:0,他引:1
实验证明,希瓦氏菌新种(ShewanellacinicaD14T)在厌氧条件下可以利用多种有机酸盐和甲苯等环境有毒污染物作为电子供体,以腐殖质作为唯一末端电子受体进行厌氧呼吸(即醌呼吸)。电子在细胞膜呼吸链的传递过程中,偶联能量的产生来支持菌体的生长,1mmol/LAQDS可支持细胞增殖约60倍。电子供体的氧化和唯一电子受体腐殖质还原之间存在着动态的偶联过程,随着电子供体量的增加腐殖质还原的量也随之增加。典型呼吸链抑制剂诸如:抑制Fe-S中心的Cu2 ,甲基萘醌类似物标桩菌素,抑制甲基萘醌氧化型向还原型转化的双香豆素和细胞色素P450的专一抑制物甲吡酮等对腐殖质的还原有着极为显著的抑制作用,为进一步证明希瓦氏菌(Shewanellacinica)D14T可利用腐殖质进行厌氧呼吸提供了有力的佐证。而D14T在进行腐殖质呼吸的同时,对于甲苯,苯胺等环境有毒物质的有效降解则具有着重要的环境学意义。 相似文献
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995.
Effects of rare earth elements on telomerase activity and apoptosis of human peripheral blood mononuclear cells 总被引:2,自引:0,他引:2
To study the effects of rare earth exposure on human telomerase and apoptosis of mononuclear cells from human peripheral blood
(PBMNCs). The blood contents of 15 rare earth elements, including La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,
and Y, were measured by inductively coupled plasma-mass spectrometry. Telomeric repeat amplification protocol assay and flow
cytometer analysis were carried out to analyze the telomerase activity and apoptosis of PBMNCs, respectively. The total content
of rare earth elements in the blood showed significant differences between the exposed group and the control group. The rare
earth exposure increased the telomerase activity and the percentages of cells in the S-phase and the G2/M phase in PBMNCs, but it had no effect on the apoptotic rate of PBMNCs. Under the exposure to lower concentrations of rare
earth elements, the telomerase activity of PBMNCs in the exposed group was higher than that of the control group, and there
was no effect on the apoptotic rate of PBMNCs, but promoted the diploid DNA replication and increased the percentages of G2/M- and S-phase cells. 相似文献
996.
Tumor angiogenesis plays an important role in tumor growth, aggression and metastasis. Many molecules have been demonstrated as positive regulators of angiogenesis, including vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and others. In recent years, significant progress has been made in the research on anti-angiogenic strategies for tumor therapies. In this review, anti-angiogenic active immunotherapies for tumors based on vaccination with xenogeneic homologous molecules and non-xenogeneic homologous molecules are discussed. 相似文献
997.
A Gram positive, rod-shaped potential strain was selected from the pool of bacterial isolates obtained from the Western Ghats
forest (India) on the basis of zone of P-solubilization activity. Identification based on 16S rRNA gene sequence revealed
that the strain is of Bacillus species, sharing highest sequence similarity to Bacillus tequilensis NRRL B-41771T (99.5%). Strain NII-0943 was able to produce good amount of indole acetic acid (IAA) and was positive for siderophore production.
In addition to IAA and siderophore attributes, strain NII-0943 also possessed the characteristics like Ca3(PO4)2 solubilization and growth in nitrogen-free medium. Seed inoculation with the strain NII-0943 resulted in significantly higher
root initiation in black pepper cuttings grown under pots. The contents of nitrogen and phosphorus in both soil and plant
were also enhanced significantly in treatments inoculated with these bacterial inocula. Hence, based on this evidence it is
proposed that strain NII-0943 could be deployed as a plant growth-promoting inoculant to attain the desired results of bacterization. 相似文献
998.
Xiao F Gao W Wang X Chen T 《Apoptosis : an international journal on programmed cell death》2012,17(6):600-611
Although caspases have been demonstrated to be involved in artemisinin (ARTE)-induced apoptosis, their exact functions are
not well understood. The aim of this report is to explore the roles of caspase-8, -9 and -3 during ARTE-induced apoptosis
in human lung adenocarcinoma (ASTC-a-1) cells. ARTE treatment induces a rapid generation of reactive oxygen species (ROS),
and ROS-dependent apoptosis as well as the activation of caspase-8, -9 and -3 via time- and dose-dependent fashion. Of upmost
importance, inhibition of caspase-8 or -9, but not caspase-3, almost completely blocks the ARTE-induced not only activation
of the caspase-8, -9 and -3 but also apoptosis. In addition, the apoptotic process triggered by ARTE does not involve the
Bid cleavage, tBid translocation, significant loss of mitochondrial membrane potential and cytochrome c release from mitochondria.
Moreover, silencing Bax/Bak does not prevent the ATRE-induced cell death as well as the activation of caspase-8, -9 and -3.
Collectively, our data firstly demonstrate that ARTE triggers a ROS-mediated positive feedback amplification activation loop
between caspase-8 and -9 independent of mitochondria, which dominantly mediated the ARTE-induced apoptosis via a caspase-3-independent
apoptotic pathway in ASTC-a-1 cells. Our findings imply a potential to develop new derivatives from artemisinin to effectively
initiate the amplification activation loop of caspases. 相似文献
999.
Immunohistochemical analysis of formalin-fixed paraffin-embedded tissues can be challenging due to potential modifications
of protein structure by exposure to formalin. Heat-induced antigen retrieval techniques can reverse reactions between formalin
and proteins that block antibody recognition. Interactions between antibodies and antigens are further enhanced by microwave
irradiation, which has simplified immunohistochemical staining protocols. In this report, we modify a technique for antigen
retrieval and immunofluorescent staining of formalin-fixed paraffin-embedded tissues by showing that it works well with several
antibodies and buffers. This microwave-assisted method for antigen retrieval and immunofluorescent staining eliminates the
need for blocking reagents and extended washes, which greatly simplifies the protocol allowing one to complete the analysis
in less than 3 h. 相似文献
1000.
A europium‐sensitized fluorescence spectrophotometry method using an anionic surfactant, sodium dodecyl benzene sulphonate (SDBS), was developed for the determination of gatifloxacin (GFLX). The GFLX–Eu3+–SDBS system was studied and it was found that SDBS significantly enhanced the fluorescence intensity of the GFLX–Eu3+ complex (about 25‐fold). The optimal experimental conditions were determined as follows: excitation and emission wavelengths of 338 and 617 nm, pH 7.5, 3.0 × 10–6 mol/L europium(III), and 5.0 × 10–5 mol/L SDBS. The enhanced fluorescence intensity of the system (ΔIf) showed a good linear relationship with the concentration of GFLX over the range 1.0 × 10–8–8.0 × 10–7 mol/L with a correlation coefficient of 0.9990. The detection limit (S:N = 3) was determined as 1.0 × 10–9 mol/L. This method has been successfully applied for the determination of GFLX in pharmaceuticals and human urine/serum samples. Compared with most other methods reported, the rapid and simple procedure proposed here offered higher sensitivity, wider linear range and good stability. The luminescence mechanism of the system is also discussed in detail. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献