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11.
Daniele Sblattero Fiorella Florian Elisabetta Azzoni Trevin Zyla Min Park Valentina Baldas Tarcisio Not Alessandro Ventura Andrew Bradbury Roberto Marzari 《European journal of biochemistry》2002,269(21):5175-5181
Celiac disease is an intestinal malabsorption characterized by an intolerance to cereal proteins accompanied by immunological responses to dietary gliadins and an autoantigen located in the endomysium. The latter has been identified as the enzyme tissue transglutaminase which belongs to a family of enzymes that catalyze protein cross-linking reactions and is constitutively expressed in many tissues as well as being activated during apoptosis. In a recent paper, we described the selection and characterization of anti-transglutaminase Igs from phage antibody libraries created from intestinal lymphocytes from celiac disease patients. In this work, using transglutaminase gene fragments, we identify a region of tissue transglutaminase recognized by these antibodies as being conformational and located in the core domain of the enzyme. This is identical to the region recognized by anti-transglutaminase Igs found in the serum of celiac disease patients. 相似文献
12.
Marie-Aleth Lacaille-Dubois Dieudonné Emmanuel Pegnyemb Olivier Placide Noté Anne-Claire Mitaine-Offer 《Phytochemistry Reviews》2011,10(4):565-584
The aim of this review is to highlight updated results on the biologically active saponins from Leguminosae-Mimosoideae. Acacic
acid-type saponins (AATS), is a class of very complex glycosides possessing a common aglycon unit of the oleanane-type (acacic
acid = 3β, 16α, 21β trihydroxy-olean-12-en-28 oic acid), having various oligosaccharide moieties at C-3 and C-28 and an acyl
group at C-21. About sixty molecules of this type have been actively explored in recent years from Leguminosae family, from
a chemical point of view and some fifty were reported to possess cancer related activities. These include cytotoxic/antitumor,
immunomodulatory, antimutagenic, and apoptosis inducing properties and appear to depend on the acylation and esterification
by different moieties at C-21 and C-28 of the acacic acid-type aglycone. One can observe that the (6S) configuration of the outer monoterpenyl moiety (MT) seems more potent in mediating high cytotoxicity than its (6R) isomer. Furthermore, the trisaccharide moiety {β-d-Xylopyranosyl-(1→2)-β-d-Fucopyranosyl-(1→6)- N-Acetamido 2-β-d-Glucopyranosyl-} at C-3, the tetrasaccharide moiety {β-d-Glucopyranosyl-(1→3)-[α-L-Arabinofuranosyl-(1→4)]-α-l-Rhamnopyranosyl-(1→2)-β-d-Glucopyranosyl} at C-28 of the aglycone, and the inner MT hydroxylated at its C-9, having a (6S) configuration can be important substituent patterns for the induction of apoptosis of AATS. Because of their interesting
cytotoxic/apoptosis inducing activity, some AATS can be useful in the search for new potential antitumor agents from Fabaceae.
Furthermore, the sequence 28-O-{Glc-(1→3)-[Araf-(1→4)]-Rha-(1→2)-Glc-Acacic acid}, often encountered in the genera Acacia, Albizia, Archidendron, and Pithecellobium may represent a chemotaxonomic marker of the Mimosoideae subfamily. 相似文献
13.
Letterio Guglielmo Roberta Minutoli Alessandro Bergamasco Antonia Granata Giacomo Zagami Tarcisio Antezana 《Polar Biology》2011,34(9):1301-1317
Knowledge on community structure oriented to describe energy flow during late summer season in Paso Ancho basin (Strait of
Magellan) is scarce and particularly affected by vertical diel migration (VDM). The main aim of this work is to identify the
VDM patterns of selected species and functional feeding groups of mesozooplankton, collected by the electronic multinet BIONESS
in 1995. Detailed studies were carried out on keystone components of the community: 7 species of copepods (Ctenocalanus citer, Drepanopus forcipatus, Metridia lucens, Clausocalanus brevipes, Scolecithricella minor, Paraeuchaeta antarctica,
Calanus simillimus), one ostracod (Discoconchoecia elegans), one chaetognath (Sagitta tasmanica), one euphausiid (Euphausia vallentini), and two polychaetes (Pelagobia longicirrata, Tomopteris planktonis). Unexpected deviations from the classic pattern reported in literature were uncovered. The shallow layer mesozooplankton
at night, although dominated by exclusively or preferentially herbivores, particularly by E. vallentini, was not represented by several species known as herbivores that remained in the deep layer throughout the day cycle. The
deep-layer zooplankton throughout the day cycle was well represented by carnivores, detritivores, and omnivores. It is suggested
that during low-chlorophyll summer conditions, the composition of functional groups and diet, and VDM patterns changed to
take advantage of sinking phytoplankton and picoplankton in deep layers. Pelagic-benthic coupling would be strengthened due
to animals that suppressed their vertical daily rise to the shallow layer at nights but remained in the deep layers to feed
on a rain of particulate organic matter and other non-migrant zooplankton. 相似文献
14.
Open oceanic calcification is mainly driven by unicellular organisms and in particular by eukaryotes such as coccolithophores and foraminifers. Open ocean microcalcifiers, like most planktonic protists, are characterized by extremely fast generation times and occasional sexual reproduction. Populations can alternate between diploid and haploid stages, which often build different kinds of cell covers. In the most important pelagic calcifiers, the coccolithophores, the diploid and haploid stages, which can self‐replicate and grow independently, display radically different morphologies with different modes of calcification or even with the absence of calcification in at least one life cycle stage. Although life cycle strategies seem likely to fundamentally influence the where and when of open ocean calcification, this issue has yet to be seriously addressed in the natural environment. Here, we introduce a new morphogenetic method, “combined CaCO3 optical detection with fluorescent in situ hybridization,” or COD‐FISH, which is based on a combination of TSA‐FISH and polarized optical microscopy. This technique allows simultaneous assessment of the taxonomic and life cycle status of single coccolithophore cells collected from the ocean. We demonstrate the application of COD‐FISH using both laboratory culture and field samples and discuss its potential value for assessing the ecology, biodiversity, population structure, and life cycles of coccolithophores and other open ocean unicellular calcifiers. 相似文献
15.
16.
Phylogenetic relationships and evolutionary patterns of the order Collodaria (Radiolaria) 总被引:1,自引:0,他引:1
Collodaria are the only group of Radiolaria that has a colonial lifestyle. This group is potentially the most important plankton in the oligotrophic ocean because of its large biomass and the high primary productivity associated with the numerous symbionts inside a cell or colony. The evolution of Collodaria could thus be related to the changes in paleo-productivity that have affected organic carbon fixation in the oligotrophic ocean. However, the fossil record of Collodaria is insufficient to trace their abundance through geological time, because most collodarians do not have silicified shells. Recently, molecular phylogeny based on nuclear small sub-unit ribosomal DNA (SSU rDNA) confirmed Collodaria to be one of five orders of Radiolaria, though the relationship among collodarians is still unresolved because of inadequate taxonomic sampling. Our phylogenetic analysis has revealed four novel collodarian sequences, on the basis of which collodarians can be divided into four clades that correspond to taxonomic grouping at the family level: Thalassicollidae, Collozoidae, Collosphaeridae, and Collophidae. Comparison of the results of our phylogenetic analyses with the morphological characteristics of each collodarian family suggests that the first ancestral collodarians had a solitary lifestyle and left no silica deposits. The timing of events estimated from molecular divergence calculations indicates that naked collodarian lineages first appeared around 45.6 million years (Ma) ago, coincident with the diversification of diatoms in the pelagic oceans. Colonial collodarians appeared after the formation of the present ocean circulation system and the development of oligotrophic conditions in the equatorial Pacific (ca. 33.4 Ma ago). The divergence of colonial collodarians probably caused a shift in the efficiency of primary production during this period. 相似文献
17.
There is increasing awareness that many terrestrial and aquatic organisms are not strictly heterotrophic or autotrophic but rather mixotrophic. Mixotrophy is an intermediate nutritional strategy, merging autotrophy and heterotrophy to acquire organic carbon and/or other elements, mainly N, P or Fe. We show that both terrestrial and aquatic mixotrophs fall into three categories, namely necrotrophic (where autotrophs prey on other organisms), biotrophic (where heterotrophs gain autotrophy by symbiosis) and absorbotrophic (where autotrophs take up environmental organic molecules). Here we discuss their physiological and ecological relevance since mixotrophy is found in virtually every ecosystem and occurs across the whole eukaryotic phylogeny, suggesting an evolutionary pressure towards mixotrophy. Ecosystem dynamics tend to separate light from non‐carbon nutrients (N and P resources): the biological pump and water stratification in aquatic ecosystems deplete non‐carbon nutrients from the photic zone, while terrestrial plant successions create a canopy layer with light but devoid of non‐carbon soil nutrients. In both aquatic and terrestrial environments organisms face a grand écart (dancer's splits, i.e., the need to reconcile two opposing needs) between optimal conditions for photosynthesis vs. gain of non‐carbon elements. We suggest that mixotrophy allows adaptation of organisms to such ubiquist environmental gradients, ultimately explaining why mixotrophic strategies are widespread. 相似文献
18.
Mapping of picoeucaryotes in marine ecosystems with quantitative PCR of the 18S rRNA gene 总被引:2,自引:0,他引:2
A quantitative PCR (QPCR) assay based on the use of SYBR Green I was developed to assess the abundance of specific groups of picoeukaryotes in marine waters. Six primer sets were designed targeting four different taxonomic levels: domain (Eukaryota), division (Chlorophyta), order (Mamiellales) and genus (Bathycoccus, Micromonas, and Ostreococcus). Reaction conditions were optimized for each primer set which was validated in silico, on agarose gels, and by QPCR against a variety of target and non-target cultures. The approach was tested by estimating gene copy numbers for Micromonas, Bathycoccus, and Ostreococcus in seawater samples to which cultured cells were added in various concentrations. QPCR was then used to determine that rRNA gene (rDNA) copy number varied from one to more than 12,000 in 18 strains of phytoplankton. Finally, QPCR was applied to environmental samples from a Mediterranean Sea coastal site and the results were compared to those obtained by Fluorescent in situ hybridization (FISH). The data obtained demonstrate that Chlorophyta and more specifically Mamiellales were important in these waters, especially during the winter picoplankton bloom. The timing of major abundance peaks of the targeted species was similar by QPCR and FISH. When used in conjunction with other techniques such as FISH or gene clone libraries, QPCR appears as very promising to quickly obtain data on the ecological distribution of important phytoplankton groups. Data interpretation must take into account primer specificity and the varying rRNA gene copy number among eukaryotes. 相似文献
19.
Tarcisio Passos Ribeiro de Campos Bruno M. Mendes Bruno Trindade Wagner L. Araujo 《Reports of Practical Oncology and Radiotherapy》2018,23(5):384-391
Aim
The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6?MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16?MeV applied in the left breast, considering the adoption of a combined photon (16?Gy) and electron (30?Gy) protocols.Materials and methods
The modified ICRP-reference female model of 60?kg, 163?cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered.Results
CR associated with the 6?MV, 4?MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16?MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3–5.0?Gy.Conclusions
To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16?Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8?MeV portal while 12–16?MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8–12?MeV may bring benefits, reducing CR. The lowest risk was found to 46?Gy electron portals exclusively. 相似文献20.
Analysis of the genomic basis of functional diversity in dinoflagellates using a transcriptome‐based sequence similarity network
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