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793.
Nicol Fuentes Aníbal Pauchard Paulina Sánchez Jocelyn Esquivel Alicia Marticorena 《Biological invasions》2013,15(4):847-858
There is an urgent need for comprehensive national databases on alien plant species, especially in developing countries. Despite the fact that plant invasions are considered a major threat to biodiversity, they have been poorly studied or not considered a conservation priority in South America. We aim to assess alien plant distribution in Chile, using the first comprehensive public alien plant database, and discuss the implications of using herbarium records to develop national databases of alien plants. We used herbarium records to assemble a comprehensive national database of alien plants. We calculated the number of alien and native species and specimens recorded in each 10 × 10 km cell. We evaluated sampling efforts and tested for relationships between alien and native species collections, as well as other spatial patterns along the latitudinal gradient. Alien and native species richness was positively correlated. Alien plants were mostly collected in central Chile, with few species collected in both the extreme north and south. However, native plants were strongly collected in central Chile, as well as in both extremes of the country. Alien and native plants followed the same pattern of accumulation along the latitudinal gradient, with native plants being relatively more collected than alien plants. Herbarium records provide valuable baseline information to evaluate plant species distribution. However, there are important gaps in this database, (e.g. variable sampling effort for alien and native plants, incomplete information on life-history traits). Given scientists and land managers increasing demand for baseline information and the high cost of collecting such data in developing countries, herbarium records should be used more frequently for research and management of plant invasions. 相似文献
794.
Gabriela Paraschiv Cécile Vincke Paulina Czaplewska Marilena Manea Serge Muyldermans Michael Przybylski 《Journal of molecular recognition : JMR》2013,26(1):1-9
ß‐Amyloid (Aß) immunotherapy has become a promising strategy for reducing the level of Aß in brain. New immunological approaches have been recently proposed for rapid, early diagnosis, and molecular treatment of neurodegenerative diseases related to Alzheimer's Disease (AD). The combination of proteolytic epitope excision and extraction and mass spectrometry using digestion with various proteases has been shown to be an efficient tool for the identification and molecular characterization of antigenic determinants. Here, we report the identification of the Aβ epitope recognized by the variable domain of single chain llama anti‐Aβ‐antibodies, termed Aβ‐nanobodies, that have been discovered in the blood of camelids and found to be promising candidates for immunotherapy of AD. The epitope recognized by two Aβ‐specific nanobodies was identified by proteolytic epitope extraction‐ and excision‐mass spectrometry using a series of proteases (trypsin, chymotrypsin, GluC‐protease, and LysC‐protease). Matrix‐assisted laser desorption ionization – mass spectrometric analysis of the affinity – elution fraction provided the epitope, Aβ(17–28), in the mid‐ to carboxy‐terminal domain of Aβ, which has been shown to exert an Aß‐fibril inhibiting effect. Affinity studies of the synthetic epitope confirmed that the Aβ(17–28) peptide is the minimal fragment that binds to the nanobodies. The interactions between the nanobodies and full length Aβ(1–40) or Aβ‐peptides containing or lacking the epitope sequence were further characterized by enzyme linked immunosorbent assay and bioaffinity analysis. Determinations of binding affinities between the Aβ‐nanobodies and Aβ(1–40) and the Aβ(17–28) epitope provided KD values of approximately 150 and 700 nmol, respectively. Thus, the knowledge of the epitope may be highly useful for future studies of Aβ‐aggregation (oligomerization and fibril formation) and for designing new aggregation inhibitors. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
795.
Protein cryoprotective activity of a cytosolic small heat shock protein that accumulates constitutively in chestnut stems and is up-regulated by low and high temperatures 下载免费PDF全文
Lopez-Matas MA Nuñez P Soto A Allona I Casado R Collada C Guevara MA Aragoncillo C Gomez L 《Plant physiology》2004,134(4):1708-1717
796.
Carlyn A. Figueiredo Paulina C. Drohomyrecky Stephen D. S. McCarthy Danila Leontyev Xue-Zhong Ma Donald R. Branch Shannon E. Dunn 《PloS one》2014,9(7)
Background
Intravenous immunoglobulin (IVIg) has been used to treat a variety of autoimmune disorders including multiple sclerosis (MS); however its mechanism of action remains elusive. Recent work has shown that interleukin-11 (IL-11) mRNAs are upregulated by IVIg in MS patient T cells. Both IVIg and IL-11 have been shown to ameliorate experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The objective of this study was to determine whether the protective effects of IVIg in EAE occur through an IL-11 and IL-11 receptor (IL-11R)-dependent mechanism.Methods
We measured IL-11 in the circulation of mice and IL-11 mRNA expression in various organs after IVIg treatment. We then followed with EAE studies to test the efficacy of IVIg in wild-type (WT) mice and in mice deficient for the IL-11 receptor (IL-11Rα−/−). Furthermore, we evaluated myelin-specific Th1 and Th17 responses and assessed spinal cord inflammation and demyelination in WT and IL-11Rα−/− mice, with and without IVIg treatment. We also examined the direct effects of mouse recombinant IL-11 on the production of IL-17 by lymph node mononuclear cells.Results
IVIg treatment induced a dramatic surge (>1000-fold increase) in the levels of IL-11 in the circulation and a prominent increase of IL-11 mRNA expression in the liver. Furthermore, we found that IL-11Rα−/− mice, unlike WT mice, although initially protected, were resistant to full protection by IVIg during EAE and developed disease with a similar incidence and severity as control-treated IL-11Rα−/− mice, despite initially showing protection. We observed that Th17 cytokine production by myelin-reactive T cells in the draining lymph nodes was unaffected by IVIg in IL-11Rα−/− mice, yet was downregulated in WT mice. Finally, IL-11 was shown to directly inhibit IL-17 production of lymph node cells in culture.Conclusion
These results implicate IL-11 as an important immune effector of IVIg in the prevention of Th17-mediated autoimmune inflammation during EAE. 相似文献797.
Marta Hałasa Dominika Cieślak Agnieszka A. Kaczor Paulina Miziak Andrzej Stepulak 《Journal of biomolecular structure & dynamics》2020,38(5):1283-1291
AbstractThe sirtuin family comprises seven NAD+-dependent histone deacetylases named SIRT1 to SIRT7. The least investigated SIRT7 is currently considered as a promising therapeutic target for cardiovascular diseases, diabetes and different types of cancer. So far, its structure was not experimentally resolved, except of a fragment of its N-terminus. The aim of this study was to create in silico model of SIRT7 containing its core together with N-terminus, which is known to affect the enzyme’s catalytic activity and to find pockets that could be targeted by structure-based virtual screening. Homology model of SIRT7 was prepared using X-ray structures of other sirtuins and a resolved fragment of the N-terminus of SIRT7 as templates. All atom-unbiased molecular dynamics simulations were performed. It was found that N-terminus of SIRT7 remains in spatial proximity of the catalytic core for considerable fraction of time, and therefore, it may affect its catalytic activity by helping the enzyme to hold the substrate peptide. It may also participate in holding and release of the cofactor. Preferred orientations of NAD+?and acetyl-lysine inside SIRT7 were found, with all components forming a stable complex. Molecular dynamics provided an ensemble of conformations that will be targeted with virtual screening. Reliable in silico structure of SIRT7 will be a useful tool in searching for its inhibitors, which can be potential drugs in cancer treatment.Communicated by Ramaswamy H. Sarma 相似文献
798.
Edyta Koscianska Julia Starega-Roslan Lukasz J Sznajder Marta Olejniczak Paulina Galka-Marciniak Wlodzimierz J Krzyzosiak 《BMC molecular biology》2011,12(1):14
Background
Numerous microRNAs (miRNAs) have heterogeneous ends resulting from imprecise cleavages by processing nucleases and from various non-templated nucleotide additions. The scale of miRNA end-heterogeneity is best shown by deep sequencing data revealing not only the major miRNA variants but also those that occur in only minute amounts and are unlikely to be of functional importance. All RNA interference (RNAi) technology reagents that are expressed and processed in cells are also exposed to the same machinery generating end-heterogeneity of the released short interfering RNAs (siRNAs) or miRNA mimetics. 相似文献799.
Previously we reported that immunization with Escherichia coli DH5alpha-expressing Brucella abortus Cu/Zn superoxide dismutase [E. coli (pBSSOD)] induces a protective immune response in BALB/c mice. Here we studied the type of immune defense that the recombinant E. coli induces in mice using as our experimental model Brucella superoxide dismutase Cu/Zn presented by J744.A1 to sensitized lymphocytes as the target of specific lysis or as cytokine inductors. The results indicate that E. coli carrying the Cu/Zn gene was able to induce specific cytotoxic T cells, mainly from CD8(+) subpopulation and IFN-gamma-producing cells belonging in their vast majority to the CD4(+) subpopulation. 相似文献
800.
Freddy Mora Osvin Arriagada Paulina Ballesta Eduardo Ruiz 《Journal of plant biochemistry and biotechnology.》2017,26(3):274-281
Given the impact of climate change on the availability of water resources, it becomes necessary the use of plant species well suited to planting on dryland sites. Eucalyptus cladocalyx, a native tree of South Australia, is capable of growing under relatively dry environments and saline soils. Two hundred twenty simple sequence repeat (microsatellites) markers, from a consensus linkage map of Eucalyptus, were selected to examine genetic diversity and population structure in a collection of E. cladocalyx introduced to southern Atacama Desert, Chile. A total of 130 microsatellites were successfully amplified, some of which are associated with quantitative traits of interest in Eucalyptus. Genetic analysis revealed a total of 457 alleles, ranging from 2 to 8 alleles per locus. A moderate level of genetic diversity (He = 0.492) and differentiation (FST = 0.086) was found among the populations. Mount Remarkable and Marble Range showed the highest and lowest level of genetic diversity, respectively. The Bayesian clustering analysis revealed three homogeneous genetic groups confirming that the individuals of E. cladocalyx from natural forest are highly and significantly structured. These results provide a novel information for the development of breeding strategies in E. cladocalyx by using marker-assisted selection in regions with low rainfall patterns. 相似文献