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11.
Rivelli AR De Maria S Puschenreiter M Gherbin P 《International journal of phytoremediation》2012,14(4):320-334
We investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of Cd; 5 and 300 mg kg(-1) of Cd and Zn, respectively; 5, 300, and 400 mg kg(-1) of Cd, Zn, and Cu, respectively. Contaminants applied did not produce large effects on growth, except in Cd-Zn-Cu treatment in which leaf area and total dry matter were reduced, by 15%. The contamination with Cd alone did not affect neither growth nor physiological parameters, despite considerable amounts of Cd accumulated in roots and older leaves, with a high bioconcentration factor from soil to plant. By adding Zn and then Cu to Cd in soil, significant were the toxic effects on chlorophyll content and water relations due to greater accumulation of trace elements in tissues, with imbalances in nutrients uptake. Highly significant was the interaction between shoot elements concentration (Cd, Zn, Cu, Fe, Mg, K, Ca) and treatments. Heavy metals concentrations in roots always exceeded those in stem and leaves, with a lower translocation from roots to shoots, suggesting a strategy of sunflower to compartmentalise the potentially toxic elements in physiologically less active parts in order to preserve younger tissues. 相似文献
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In this study we describe the sociodemographic characteristics of people participating in a clinical trial on the safety and immunogenicity of a H5N1 influenza vaccine and we identify the main motivations for joining it. 相似文献
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Brohem CA Massaro RR Tiago M Marinho CE Jasiulionis MG de Almeida RL Rivelli DP Albuquerque RC de Oliveira TF de Melo Loureiro AP Okada S Soengas MS de Moraes Barros SB Maria-Engler SS 《Pigment cell & melanoma research》2012,25(3):354-369
Induction of apoptotic cell death in response to chemotherapy and other external stimuli has proved extremely difficult in melanoma, leading to tumor progression, metastasis formation and resistance to therapy. A promising approach for cancer chemotherapy is the inhibition of proteasomal activity, as the half‐life of the majority of cellular proteins is under proteasomal control and inhibitors have been shown to induce cell death programs in a wide variety of tumor cell types. 4‐Nerolidylcatechol (4‐NC) is a potent antioxidant whose cytotoxic potential has already been demonstrated in melanoma tumor cell lines. Furthermore, 4‐NC was able to induce the accumulation of ubiquitinated proteins, including classic targets of this process such as Mcl‐1. As shown for other proteasomal inhibitors in melanoma, the cytotoxic action of 4‐NC is time‐dependent upon the pro‐apoptotic protein Noxa, which is able to bind and neutralize Mcl‐1. We demonstrate the role of 4‐NC as a potent inducer of ROS and p53. The use of an artificial skin model containing melanoma also provided evidence that 4‐NC prevented melanoma proliferation in a 3D model that more closely resembles normal human skin. 相似文献
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Background
The Prisoner's Dilemma (PD) is a widely used paradigm to study cooperation in evolutionary biology, as well as in fields as diverse as moral philosophy, sociology, economics and politics. Players are typically assumed to have fixed payoffs for adopting certain strategies, which depend only on the strategy played by the opponent. However, fixed payoffs are not realistic in nature. Utility functions and the associated payoffs from pursuing certain strategies vary among members of a population with numerous factors. In biology such factors include size, age, social status and expected life span; in economics they include socio-economic status, personal preference and past experience; and in politics they include ideology, political interests and public support. Thus, no outcome is identical for any two different players. 相似文献16.
A quantitative capillary assay was used to show that aromatic acids, compounds that are chemorepellents for Escherichia coli and Salmonella sp., are chemoattractants for Pseudomonas putida PRS2000. The most effective attractants were benzoate; p-hydroxybenzoate; the methylbenzoates; m-, p-, and o-toluate; salicylate; DL-mandelate; beta-phenylpyruvate; and benzoylformate. The chemotactic responses to these compounds were inducible. Taxis to benzoate and m-toluate was induced by beta-ketoadipate, a metabolic intermediate formed when benzoate is dissimilated via enzymes specified by chromosomal genes. Benzoylformate taxis was induced by benzoylformate and L(+)-mandelate. Taxis to mandelate, benzoylformate, and beta-phenylpyruvate was exhibited by cells grown on mandelate, but not by cells grown on benzoate. Cells grown on benzoate were chemotactic to benzoate, the toluates, p-hydroxybenzoate, and salicylate. These results show that P. putida synthesizes at least two distinct chemoreceptors for aromatic acids. Although DL-mandelate was an effective attractant in capillary assays, additional experiments indicated that the cells were actually responding to benzoylformate, a metabolite formed from mandelate. With the exception of mandelate taxis, chemotaxis to aromatic acids was not dependent on the expression of pathways for aromatic degradation. Therefore, the tactic responses exhibited by cells cannot be attributed to an effect of the oxidation of aromatic acids on the energy metabolism of cells. 相似文献
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V?Srinivasan GJM?Maestroni DP?Cardinali AI?Esquifino SR?Pandi?Perumal SC?MillerEmail author 《Immunity & ageing : I & A》2005,2(1):17
Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence
of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration
with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages
and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide
generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas
CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness.
Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect.
Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of
NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper
lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid
network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the
potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state. 相似文献
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Evolution of the WANCY region in amniote mitochondrial DNA 总被引:7,自引:1,他引:6
In most vertebrate mitochondrial genomes, the site for initiation of
light-strand replication, OL, is found within a cluster of five transfer
RNA (tRNA) genes (tRNA(Trp), tRNA(Ala), tRNA(Asn), tRNA(Cys), and
tRNA(Tyr)). This region and part of the adjacent cytochrome c oxydase
subunit I (COI) gene were sequenced for two crocodilian, two turtle, and
one snake species and for Sphenodon punctatus; part of the adjacent
nicotinamide adenine dinucleotide dehydrogenase subunit 2 (ND2) gene was
also sequenced for the crocodilian and turtle species. All had the typical
vertebrate gene order. The turtles and the snake have a lengthy noncoding
sequence between the tRNA(Asn) and tRNA(Cys) genes that we assumed to be
homologous to the mammalian OL. The crocodilians and Sphenodon lack such a
sequence, a condition they share with birds. Most proposed phylogenies for
the amniotes require that OL at this position was lost at least twice
during their diversification or was evolved independently more than once.
Within the five tRNA genes, frequencies of substitutions are much higher in
loops than in stems. Many loops vary dramatically in size among the
species; in the most extreme case, the D-arm of the Sphenodon tRNA(Cys) is
a "D-arm replacement" loop of seven nucleotides. Frequency of transitions
in stems is relatively uniform across tRNAs, but frequency of transversions
varies greatly. Mismatches in stems are infrequent, and their relative
frequency in a specific tRNA is unrelated to the frequency of substitution
in the corresponding gene. Several features of mammalian mitochondrial
tRNAs are conserved in WANCY tRNAs throughout amniotes. The inferred
initiation codon for COI is GTG in crocodilians, turtles, and the snake, a
condition they share with fishes, certain amphibians, and birds. TTG
appears to be the initiation codon for COI in Sphenodon; if correct, this
would be a novel initiation codon for vertebrate mitochondrial DNA.
Phylogenetic analyses of the inferred amino acid sequences of ND2 and COI
support the sister-group relationship of birds and crocodilians and suggest
that mammals are an early derived lineage within the amniotes.
相似文献
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Valentina Rivelli Andrea Franzetti Isabella Gandolfi Sergio Cordoni Giuseppina Bestetti 《Biodegradation》2013,24(1):1-11
Rhodococcus sp. and Pseudomonas sp. bioremediation experiments were carried out using free and immobilized cells on natural carrier material (corncob powder) in order to evaluate the feasibility of its use in the bioremediation of hydrocarbon-contaminated soils. Terminal restriction fragment length polymorphism analysis was performed on the 16S rRNA gene as molecular fingerprinting method in order to assess the persistence of inoculated strains in the soil over time. Immobilized Pseudomonas cells degraded hydrocarbons more efficiently in the short term compared to the free ones. Immobilization seemed also to increase cell growth and stability in the soil. Free and immobilized Rhodococcus cells showed comparable degradation percentages, probably due to the peculiarity of Rhodococcus cells to aggregate into irregular clusters in the presence of hydrocarbons as sole carbon source. It is likely that the cells were not properly adsorbed on the porous matrix as a result of the small size of its pores. When Rhodococcus and Pseudomonas cells were co-immobilized on the matrix, a competition established between the two strains, that probably ended in the exclusion of Pseudomonas cells from the pores. The organic matrix might act as protective agent, but it also possibly limited cell density. Nevertheless, when the cells were properly adsorbed on the porous matrix, the immobilization became a suitable bioremediation strategy. 相似文献