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61.
62.
Inflammatory mediators and cytokines play important roles in the pathogenesis of a vast number of human diseases; therefore much attention is focused on blunting their proinflammatory modes of action. The aims of the present research were to assess the effectiveness of combinations of carotenoids and phenolics, at concentrations that can be achieved in blood, to inhibit the release of inflammatory mediators from macrophages exposed to lipopolysaccharide (LPS) and to determine what the anti-inflammatory effect of the phytonutrient combinations was in an in vivo mouse model of peritonitis. Preincubation of mouse peritoneal macrophages with lycopene (1μM) or Lyc-O-Mato (1μM) and carnosic acid (2μM), lutein (1μM), and/or β-carotene (2μM) 1h before addition of LPS for 24h caused a synergistic inhibition of NO, prostaglandin E(2), and superoxide production derived from downregulation of iNOS, COX-2, and NADPH oxidase protein and mRNA expression and synergistic inhibition of TNFα secretion. We surmise that the anti-inflammatory action of the phytonutrient combinations used probably resides in their antioxidant properties, because they caused an immediate, efficient, and synergistic inhibition of LPS-induced internal superoxide production leading to a marked decrease in ERK and NF-κB activation. The anti-inflammatory effects of the selected phytonutrient combinations were also demonstrated in a mouse model of peritonitis: their supplementation in drinking water resulted in attenuation of neutrophil recruitment to the peritoneal cavity and in inhibition of inflammatory mediator production by peritoneal neutrophils and macrophages.  相似文献   
63.
In order to broaden the available genetic variation of melon, we developed an ethyl methanesulfonate mutation library in an orange-flesh ‘Charentais’ type melon line that accumulates β-carotene. One mutagenized M2 family segregated for a novel recessive trait, a yellow–orange fruit flesh (‘yofI’). HPLC analysis revealed that ‘yofI’ accumulates pro-lycopene (tetra-cis-lycopene) as its major fruit pigment. The altered carotenoid composition of ‘yofI’ is associated with a significant change of the fruit aroma since cleavage of β-carotene yields different apocarotenoids than the cleavage of pro-lycopene. Normally, pro-lycopene is further isomerized by CRTISO (carotenoid isomerase) to yield all-trans-lycopene, which is further cyclized to β-carotene in melon fruit. Cloning and sequencing of ‘yofI’ CRTISO identified two mRNA sequences which lead to truncated forms of CRTISO. Sequencing of the genomic CRTISO identified an A–T transversion in ‘yofI’ which leads to a premature STOP codon. The early carotenoid pathway genes were up regulated in yofI fruit causing accumulation of other intermediates such as phytoene and ζ-carotene. Total carotenoid levels are only slightly increased in the mutant. Mutants accumulating pro-lycopene have been reported in both tomato and watermelon fruits, however, this is the first report of a non-lycopene accumulating fruit showing this phenomenon.  相似文献   
64.
The effects of three isopropyl carbanilate derivatives (propham, chlorpropham, 3,4-diCl isopropyl carbanilate) were studied on Acer pseudoplatanus L. cell suspension cultures (Lamport's strain). At 0.1 m M , three types of effects were observed: the 3,4-diCl derivative rapidly killed the cells; chlorpropham inhibited mitosis, but the cells remained alive without any significant increase in fresh or dry matter; and propham strongly inhibited mitosis, but not cell growth.
Ultrastructural analysis indicated that no observable changes in mitochondrial or plastid density occurred during the cytoplasmic expansion in the presence of propham. Size increase was also accompanied by vacuolar expansion and morphological changes of the nuclei. In Acer cell cultures, isopropyl carbanilates clearly show selective inhibition of mitosis only when the phenyl ring is not substituted by chlorine.  相似文献   
65.

Background

Neural stem cells are currently being investigated as potential therapies for neurodegenerative diseases, stroke, and trauma. However, concerns have been raised over the safety of this experimental therapeutic approach, including, for example, whether there is the potential for tumors to develop from transplanted stem cells.

Methods and Findings

A boy with ataxia telangiectasia (AT) was treated with intracerebellar and intrathecal injection of human fetal neural stem cells. Four years after the first treatment he was diagnosed with a multifocal brain tumor. The biopsied tumor was diagnosed as a glioneuronal neoplasm. We compared the tumor cells and the patient''s peripheral blood cells by fluorescent in situ hybridization using X and Y chromosome probes, by PCR for the amelogenin gene X- and Y-specific alleles, by MassArray for the ATM patient specific mutation and for several SNPs, by PCR for polymorphic microsatellites, and by human leukocyte antigen (HLA) typing. Molecular and cytogenetic studies showed that the tumor was of nonhost origin suggesting it was derived from the transplanted neural stem cells. Microsatellite and HLA analysis demonstrated that the tumor is derived from at least two donors.

Conclusions

This is the first report of a human brain tumor complicating neural stem cell therapy. The findings here suggest that neuronal stem/progenitor cells may be involved in gliomagenesis and provide the first example of a donor-derived brain tumor. Further work is urgently needed to assess the safety of these therapies.  相似文献   
66.
Physically building complex multi-molecular structures from naturally occurring biological macromolecules has aroused a great deal of interest. Here we focus on nanostructures composed of re-engineered, natural 'foldamer' building blocks. Our aim is to provide some of the underlying concepts and schemes for crafting structures utilizing such conformationally relatively stable molecular components. We describe how, via chemical biology strategies, it is further possible to chemically manipulate the foldamer building blocks toward specific shape-driven structures, which in turn could be used toward potential-designed functions. We outline the criteria in choosing candidate foldamers from the vast biological repertoire, and how to enhance their stability through selected targeted replacements by non-proteinogenic conformationally constrained amino acids. These approaches combine bioinformatics, high performance computations and mathematics with synthetic organic chemistry. The resulting artificially engineered self-organizing molecular scale structures take advantage of nature's nanobiology toolkit and at the same time improve on it, since their new targeted function differs from that optimized by evolution. The major challenge facing nanobiology is to be able to exercise fine control over the performance of these target-specific molecular machines.  相似文献   
67.
68.
Differences in rates of steroid production and secretion will, eventually, determine the developmental rates of ovarian follicles. The major supply of cholesterol, the precursor for steroid and androgen biosynthesis, to ovarian cells is from circulating lipoproteins via membrane receptors from the low density lipoprotein receptor (LDL) superfamily. This occurs by either endocytosis, which has been described for very low density lipoprotein receptors (VLDLr), for LDL receptors (LDLr), and by the selective uptake pathway described for the scavenger receptor class B type 1 receptor (SRB1) and the recently described ovarian receptor, lipoprotein receptor-related protein 8 (LRP8). In this study, the mRNA expression of these four cholesterol receptors in bovine ovarian cells was determined at different stages of follicular development. In small antral follicles, mRNA expression of the endocytosis receptors was higher than in large antral follicles. Expression of LRP8 mRNA increased linearly with follicular size together with an increase in LDL, VLDL, and cholesterol concentrations in the follicular fluid. SRB1 mRNA expression tended to increase with follicular diameter. Because different mRNA expression patterns were found for the two types of receptor, this may imply different regulation of cholesterol supply at different stages of follicular development. Accumulation of LDL and VLDL particles in the follicular fluid of large antral follicles may enhance cholesterol availability for the intense steroidogenic activity that is essential at these stages.  相似文献   
69.
Anthropologists dealing with death have pointed to a process of privatization, bureaucratization, and secularization of death in the age of 'high modernity'. In this article I argue that the exploration of death within the framework of modern terrorism, a form of death that is becoming increasingly common, reveals new expressions and interpretations of death that are public and are represented by a complex religious repertoire of images and practices. Based on a field study that combines in-depth interviews, observations, films, and textual analyses, this article examines how volunteers from the ' Zaka ' organization (the Jewish ultra-Orthodox team for identification of victims of disaster in Israel) explain their deathwork during terror attacks. Generally we would expect that this community's religious norms, which prevent them from involvement with the larger society, would also prevent members from participation in cases of death in the public sphere. Nevertheless, Zaka 's tasks involve collecting, matching, and recomposing pieces of human flesh and blood in the public arena. Through these new practices, Zaka volunteers shape new narratives of public death, which are based on two central premises: a discourse of 'corpse symbolism' and a narrative of taboo desecration. This language reinforces and revives Haredis' own religious expressions during terror, allowing them to monopolize the death experience and the handling of dead bodies, introduce sacred meanings of corpses and death into the public sphere, and create their new position as specialists and deathworkers.  相似文献   
70.
Detection of protein complexes and their structures is crucial for understanding their role in the basic biology of organisms. Computational docking methods can provide researchers with a good starting point for the analysis of protein complexes. However, these methods are often not accurate and their results need to be further refined to improve interface packing. In this paper, we introduce a refinement method that incorporates evolutionary information into a novel scoring function by employing Evolutionary Trace (ET)-based scores. Our method also takes Van der Waals interactions into account to avoid atomic clashes in refined structures. We tested our method on docked candidates of eight protein complexes and the results suggest that the proposed scoring function helps bias the search toward complexes with native interactions. We show a strong correlation between evolutionary-conserved residues and correct interface packing. Our refinement method is able to produce structures with better lRMSD (least RMSD) with respect to the known complexes and lower energies than initial docked structures. It also helps to filter out false-positive complexes generated by docking methods, by detecting little or no conserved residues on false interfaces. We believe this method is a step toward better ranking and prediction of protein complexes.  相似文献   
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