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971.
A total of 36 species of benthic hydroids, belonging to nine families and 16 genera, were found in the hydroid collection
gathered during the Brazilian Antarctic expeditions PROANTAR III and IV. Seven of the species were identified only to generic
level. There is a clear dominance of the subclass Leptothecatae with 33 species. By far the most diversified family was the
Sertulariidae, with 16 species (44%). Symplectoscyphus with eight species, including Symplectoscyphus magnificus sp. nov., is the most diversified genus. Almost 70% of the species diversity is restricted to just six genera (38%). Sixty-eight
percent of the species is Antarctic endemics and 86% is restricted to Antarctic or Antarctic/sub-Antarctic waters. Eudendrium antarcticum and Amphisbetia operculata are recorded for the first time from Antarctic waters. 相似文献
972.
Lotta Koskinen Jihane Romanos Katri Kaukinen Kirsi Mustalahti Ilma Korponay-Szabo Donatella Barisani Maria Teresa Bardella Fabiana Ziberna Serena Vatta György Széles Zsuzsa Pocsai Kati Karell Katri Haimila Róza Ádány Tarcisio Not Alessandro Ventura Markku Mäki Jukka Partanen Cisca Wijmenga Päivi Saavalainen 《Immunogenetics》2009,61(4):247-256
Human leukocyte antigen (HLA) genes, located on chromosome 6p21.3, have a crucial role in susceptibility to various autoimmune
and inflammatory diseases, such as celiac disease and type 1 diabetes. Certain HLA heterodimers, namely DQ2 (encoded by the
DQA1*05 and DQB1*02 alleles) and DQ8 (DQA1*03 and DQB1*0302), are necessary for the development of celiac disease. Traditional
genotyping of HLA genes is laborious, time-consuming, and expensive. A novel HLA-genotyping method, using six HLA-tagging
single-nucleotide polymorphisms (SNPs) and suitable for high-throughput approaches, was described recently. Our aim was to
validate this method in the Finnish, Hungarian, and Italian populations. The six previously reported HLA-tagging SNPs were
genotyped in patients with celiac disease and in healthy individuals from Finland, Hungary, and two distinct regions of Italy.
The potential of this method was evaluated in analyzing how well the tag SNP results correlate with the HLA genotypes previously
determined using traditional HLA-typing methods. Using the tagging SNP method, it is possible to determine the celiac disease
risk haplotypes accurately in Finnish, Hungarian, and Italian populations, with specificity and sensitivity ranging from 95%
to 100%. In addition, it predicts homozygosity and heterozygosity for a risk haplotype, allowing studies on genotypic risk
effects. The method is transferable between populations and therefore suited for large-scale research studies and screening
of celiac disease among high-risk individuals or at the population level.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Lotta Koskinen and Jihane Romanos are authors with equal contribution. 相似文献
973.
ATP Released by Electrical Stimuli Elicits Calcium Transients and Gene Expression in Skeletal Muscle
Sonja Buvinic Gonzalo Almarza Mario Bustamante Mariana Casas Javiera L��pez Manuel Riquelme Juan Carlos S��ez Juan Pablo Huidobro-Toro Enrique Jaimovich 《The Journal of biological chemistry》2009,284(50):34490-34505
ATP released from cells is known to activate plasma membrane P2X (ionotropic) or P2Y (metabotropic) receptors. In skeletal muscle cells, depolarizing stimuli induce both a fast calcium signal associated with contraction and a slow signal that regulates gene expression. Here we show that nucleotides released to the extracellular medium by electrical stimulation are partly involved in the fast component and are largely responsible for the slow signals. In rat skeletal myotubes, a tetanic stimulus (45 Hz, 400 1-ms pulses) rapidly increased extracellular levels of ATP, ADP, and AMP after 15 s to 3 min. Exogenous ATP induced an increase in intracellular free Ca2+ concentration, with an EC50 value of 7.8 ± 3.1 μm. Exogenous ADP, UTP, and UDP also promoted calcium transients. Both fast and slow calcium signals evoked by tetanic stimulation were inhibited by either 100 μm suramin or 2 units/ml apyrase. Apyrase also reduced fast and slow calcium signals evoked by tetanus (45 Hz, 400 0.3-ms pulses) in isolated mouse adult skeletal fibers. A likely candidate for the ATP release pathway is the pannexin-1 hemichannel; its blockers inhibited both calcium transients and ATP release. The dihydropyridine receptor co-precipitated with both the P2Y2 receptor and pannexin-1. As reported previously for electrical stimulation, 500 μm ATP significantly increased mRNA expression for both c-fos and interleukin 6. Our results suggest that nucleotides released during skeletal muscle activity through pannexin-1 hemichannels act through P2X and P2Y receptors to modulate both Ca2+ homeostasis and muscle physiology. 相似文献
974.
Carlos Novo Tiago M. Martins Sofia Prata ngela Lopes Ana Armada 《International journal of biological macromolecules》2009,45(4):399-406
Malaria remains one of the major human parasitic diseases, particularly in subtropical regions. Most of the fatal cases are caused by Plasmodium falciparum. The rodent parasite Plasmodium chabaudi has been the model of choice in research due to its similarities to human malaria, including developmental cycle, preferential invasion of mature erythrocytes, synchrony of asexual development, antigenic variation, gene sinteny as well as similar resistance mechanisms. Protein disulfide isomerase (PDI) is an essential catalyst of the endoplasmic reticulum in different biological systems with folding and chaperone activities. Most of the proteins exported by parasites have to pass through the endoplasmic reticulum before reaching their final destination and their correct folding is critical for parasite survival. PDI constitutes a potential target for the development of alternative therapy strategies based on the inhibition of folding and chaperoning of exported proteins. We here describe the sequencing of the gene coding for the PDI from P. chabaudi and analyse the relationship to its counterpart enzymes, particularly with the PDI from other Plasmodium species. The model constructed, based on the recent model deduced from the crystallographic structure 2B5E, was compared with the previous theoretical model for the whole PDI molecule constructed by threading. A recombinant PDI from P. chabaudi was also produced and used as an antigen for monoclonal antibody production for application in PDI immunolocalization. 相似文献
975.
Alessandra de Santana Braga Barbosa Ribeiro Cláudio Carlos da Silva Flávia de Castro Pereira Aliny Pereira de Lima Cesar Augusto Sam Tiago Vilanova-Costa Simone Santos Aguiar Luiz Alfredo Pavanin Aparecido Divino da Cruz Elisângela de Paula Silveira-Lacerda 《Biological trace element research》2009,130(3):249-261
Chemotherapeutic agents play an important role in cancer treatment mostly due their systemic action on human organism allowing
access to liquid tumors and even metastases. Among these drugs, ruthenium compounds have been showing promising results to
treat tumors and represent an important development of new antitumor therapy. This study presents the evaluation of cis-(dichloro)tetraammineruthenium(III) chloride, cis-[RuCl2(NH3)4]Cl, genotoxic effects using human peripheral blood lymphocytes cultured in vitro. Mitotic index (MI), chromosome aberrations
(CA), and DNA damage using the comet assay were analyzed. MI in human peripheral blood lymphocyte cultures treated with 1,
10, 100, and 1,000 μg mL−1
cis-[RuCl2(NH3)4]Cl were 5.9%, 4.6%, 3.9%, and 0%, respectively. Doxorubicin chloridate was used as the positive control. CA derived from
1, 10, and 100 μg mL−1 concentrations were defined as spontaneous when compared with the negative control, and at the concentration of 1,000 μg
mL−1, the cell cycle was inhibited (IM = 0%). Results obtained for the comet assay using cis-[RuCl2(NH3)4]Cl suggest that this compound has no genotoxic activity against cultured human peripheral blood lymphocytes. 相似文献
976.
Camila Infantosi Vannucchi Marcelo Faustino Mariana Groke Marques Marcílio Nichi Mayra Elena Ortiz D’Ávila Assumpção José Antonio Visintin 《In vitro cellular & developmental biology. Animal》2009,45(7):328-333
During the process of maturation in the oviduct, canine oocytes in the germinal vesicle stage are exposed to decreasing levels
of estradiol-17β and increasing levels of progesterone. However, hormone concentrations in the microenvironments in which
they act are higher than serum concentrations. Therefore, the aim of the present study was to compare the meiotic competence
of canine oocytes harvested from anestrous bitches in culture medium containing high concentrations (20 μg ml−1) of estradiol-17β and/or progesterone in association to gonadotropins (luteinizing hormone and follicle-stimulating hormone)
using three different maturation periods (48, 72, and 96 h). Oocytes were cultured in tissue culture medium (TCM-199) and
arranged in four experimental groups: group control, group E2 (estradiol-17β), group P4 (progesterone), and group E2 + P4.
Regardless of the maturation period, groups P4 and E2 + P4 presented statistically higher rate of germinal vesicle breakdown
oocytes compared to the group control and group E2. There were no significant differences among groups on germinal vesicle,
metaphase I, metaphase II, and degenerated or unidentifiable oocytes rates. The mean percentage of metaphase II oocytes was
higher at 96 h when compared to 72 h. Results of the present research indicate no influence of estradiol-17β supplementation,
unless in association with progesterone. There is an evidence of the positive effect of progesterone on germinal vesicle breakdown.
Results also showed that extended periods of in vitro maturation affect positively maturation rates to metaphase II of low
competent oocytes harvested from anestrous bitches, independent of the maturation media. In conclusion, high concentrations
of steroids, especially progesterone, have positive effect on in vitro oocyte maturation when the oocytes are derived from
the anestrous status. 相似文献
977.
The induction of several secondary metabolites in plants is one of the most commonly observed effects after the external addition of methyl jasmonate (MeJA). After the elicitation of Catharanthus roseus hairy roots with different concentrations of MeJA, changes in the accumulation of alkaloids such as ajmalicine, serpentine, ajmaline and catharanthine were observed. In addition to the increased accumulation of alkaloids in the tissues, the root exudation of phytochemicals increased compared to that of the non-treated control hairy roots. Moreover, MeJA induced differential secretion of several C. roseus hairy root metabolites. 相似文献
978.
Rosalía Piñeiro Javier Fuertes Aguilar Miguel Menezes de Sequeira Gonzalo Nieto Feliner 《Folia Geobotanica》2009,44(1):65-81
The genetic diversity and possible geographic structure of the Madeiran endemic Armeria maderensis have been assessed with AFLP. Its scarce distribution (less than 3 km between the two most distant localities) and restricted habitat (vertical pastures on the highest elevations of Madeira), at least in part due to grazing by goats, suggest an assessment of its conservation status. Diversity estimates obtained for A. maderensis were evaluated through comparison with reference values of AFLP diversity for outcrossing plants and, in order to correct for phylogenetic constraints, with a widespread congener analyzed with the same AFLP markers. Our results reveal that low levels of genetic diversity and a weak intraspecific genetic structure underlie the restricted distribution of A. maderensis. 相似文献
979.
C. Ekaterina Rodríguez-Pérez Erika Calvo-Ochoa Ekaterina V. Kalashnikova Guadalupe Reyes-Cruz M. Teresa Romero-Ávila J. Adolfo García-Sáinz 《The international journal of biochemistry & cell biology》2009,41(6):1276-1283
Human α1D-adrenoceptors (truncated at the amino terminus (Δ1–79) to increase their membrane expression) were stably expressed in Rat-1 fibroblasts (1–1.5 pmol/mg protein). The receptors were functional as evidenced by a robust increase in intracellular calcium in response to noradrenaline. Using this cell line, the possibility that activation of receptor tyrosine kinases could modulate this adrenoceptor subtype was studied. It was observed that cell preincubation with insulin, IGF-I, EGF or PDGF markedly reduced the intracellular calcium increase observed in response to noradrenaline. Inhibitors of PI3K and PKC essentially blocked insulin-, IGF-I- and EGF-induced desensitizations. Interestingly, PDGF-induced α1D-adrenergic desensitization was only partially ameliorated by PI3K inhibitors and was not affected by those of PKC. Insulin, IGF-I, EGF and PDGF induced concentration-dependent increases in the phosphorylation state of α1D-adrenoceptors; phosphorylation took place on serine residues. Inhibitors of PI3K and PKC markedly reduced the effects of insulin, IGF-I and EGF on this parameter. These inhibitors only marginally reduced PDGF-induced α1D-adrenoceptors phosphorylation. The ability of IGF-I to induce α1D-adrenergic desensitization and phosphorylation was confirmed in cells expressing non-truncated rat α1D-adrenenoceptors. Our data indicate that the function and phosphorylation state of α1D-adrenoceptors is modulated by activation of receptor tyrosine kinases. Insulin, IGF-I and EGF actions take place through the action of PI3K and PKC; additional pathway(s) seem to participate in PDGF-induced α1D-adrenoceptor desensitization and phosphorylation. 相似文献
980.
Conflicting selection on diaspore traits limits the evolutionary potential of seed dispersal by ants
Conflicts of selection on diaspore traits throughout the dispersal cycle can limit the evolutionary consequences of seed dispersal. However, these conflicts have never been investigated in directed dispersal systems. We explored conflicts of selection through life stages of dispersal in the myrmecochorous herb Helleborus foetidus. Seeds are subject to two contrasting partial selective scenarios. Undispersed seeds are subject to positive directional selection on seed size characters, whereas seeds dispersed are subject to stabilizing selection for size. In both scenarios, seedling establishment determined the magnitude and direction of selection. This does not reflect ant preferences for seed size. However, total selection still depends largely on ant activity, as ants control the relative importance of each selective scenario. We advocate the use of analytical approaches combining multiplicative fitness and microenvironment‐specific selection to more realistically estimate the realized selection on traits functional during several life stages. This approach may be extended to any organism dispersing offspring to different environments. 相似文献