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61.
Isabel Marques Antonio José Díaz‐Pérez José Ángel López‐Rodríguez Victoria Mirones Ana Sus Félix Llamas Alicia Alonso Ernesto Pérez‐Collazos Juan Viruel Elvira Sahuquillo Maria Del Carmen Sancho Benjamin Komac José Antonio Manso José Gabriel Segarra‐Moragues David Draper Luis Villar Pilar Catalán 《Botanical journal of the Linnean Society. Linnean Society of London》2013,173(4):676-706
The Iberian mountain spiny fescues are a reticulate group of five diploid grass taxa consisting of three parental species and two putative hybrids: F. × souliei (F. eskia × F. quadriflora) and F. × picoeuropeana (F. eskia × F. gautieri). Phenotypic and molecular studies were conducted with the aim of determining the taxonomic boundaries and genetic relationships of the five taxa and disentangling the origins of the two hybrids. Statistical analyses of 31 selected phenotypic traits were conducted on individuals from 159 populations and on nine type specimens. Molecular analyses of random amplified polymorphic DNA (RAPD) markers were performed on 29 populations. The phenotypic analyses detected significant differences between the five taxa and demonstrated the overall intermediacy of the F. × picoeuropeana and F. × souliei between their respective parents. The RAPD analysis corroborated the genetic differentiation of F. eskia, F. gautieri and F. quadriflora and the intermediate nature of the two hybrids; however, they also detected genetic variation within F. × picoeuropeana. These results suggest distinct origins for F. × picoeuropeana in the Cantabrian and Pyrenean mountains, with the sporadic Pyrenean populations having potentially resulted from recent hybridizations and the stabilized Cantabrian ones from older events followed by potential displacements of the parents. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 676–706. 相似文献
62.
Paula Clemente Susana Peralta Alberto Cruz-Bermudez Lucía Echevarría Flavia Fontanesi Antoni Barrientos Miguel A. Fernandez-Moreno Rafael Garesse 《The Journal of biological chemistry》2013,288(12):8321-8331
Cytochrome c oxidase (COX) or complex IV of the mitochondrial respiratory chain plays a fundamental role in energy production of aerobic cells. In humans, COX deficiency is the most frequent cause of mitochondrial encephalomyopathies. Human COX is composed of 13 subunits of dual genetic origin, whose assembly requires an increasing number of nuclear-encoded accessory proteins known as assembly factors. Here, we have identified and characterized human CCDC56, an 11.7-kDa mitochondrial transmembrane protein, as a new factor essential for COX biogenesis. CCDC56 shares sequence similarity with the yeast COX assembly factor Coa3 and was termed hCOA3. hCOA3-silenced cells display a severe COX functional alteration owing to a decreased stability of newly synthesized COX1 and an impairment in the holoenzyme assembly process. We show that hCOA3 physically interacts with both the mitochondrial translation machinery and COX structural subunits. We conclude that hCOA3 stabilizes COX1 co-translationally and promotes its assembly with COX partner subunits. Finally, our results identify hCOA3 as a new candidate when screening for genes responsible for mitochondrial diseases associated with COX deficiency. 相似文献
63.
Marina Azevêdo Souza Susana Johann Luciana Alves Rodrigues dos Santos Lima Fernanda Fraga Campos Isolda Castro Mendes Heloisa Beraldo Elaine Maria de Souza-Fagundes Patrícia Silva Cisalpino Carlos Augusto Rosa Tania Maria de Almeida Alves Nívea Pereira de Sá Carlos Leomar Zani 《Memórias do Instituto Oswaldo Cruz》2013,108(3):342-351
Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes. 相似文献
64.
Claudia Mara Maciel-Rezende Letícia de Almeida Éderson D’Martin Costa Francieli Ribeiro Pires Karina Ferreira Alves Cláudio Viegas Junior Danielle Ferreira Dias Antônio Carlos Doriguetto Marcos José Marques Marcelo Henrique dos Santos 《Bioorganic & medicinal chemistry》2013,21(11):3114-3119
Nine O-alkyl and O-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4′-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. All derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound LFQM-123 (3c) was 250-fold more active than its precursor 4,4′-dihydroxybenzophenone (3). Moreover, some of the results were comparable to the standard drug Amphotericin B, suggesting that the increase in lipophilicity could facilitate protozoa membrane permeation. In this study we confirmed that benzophenone derivatives exhibit leishmanicidal properties, with relatively low toxicity, and thus could be exploited as promise prototypes for the design and development of new drug for the treatment of leishmaniasis. 相似文献
65.
Adriana Fonseca Marques Daniel Esser Philip J. Rosenthal Matthias U. Kassack Luis Mauricio T.R. Lima 《Bioorganic & medicinal chemistry》2013,21(13):3667-3673
Falcipain-2 is a cysteine protease of the malaria parasite Plasmodium falciparum that plays a key role in the hydrolysis of hemoglobin, a process that is required by intraerythrocytic parasites to obtain amino acids. In this work we show that the polysulfonated napthylurea suramin is capable of binding to falcipain-2, inhibiting its catalytic activity at nanomolar concentrations against both synthetic substrates and the natural substrate hemoglobin. Kinetic measurements suggest that the inhibition occurs through an noncompetitive allosteric mechanism, eliciting substrate inhibition. Smaller suramin analogues and those with substituted methyl groups also showed inhibition within the nanomolar range. Our results identify the suramin family as a potential starting point for the design of falcipain-2 inhibitor antimalarials that act through a novel inhibition mechanism. 相似文献
66.
Nelson Marques John F Araujo Ana Stella F Righini J J Fleury J B F Costa-Neto Maria Clara S Caldas 《Biological Rhythm Research》2013,44(3):343-350
We describe the semen characteristics of a 21-year old “mangalarga” stallion living under natural temperature and photoperiod conditions in São José do Rio Pardo, São Paulo, Brazil (latitude 21°36' S; longitude 46°53' W). The horse fed on natural pasture and a nutritionally balanced feed twice a day (11:00 and 17:00 h). Water and a mineral supplement were available “ad libitum”. Semen was collected for over 36 months (Oct 89-Dec 92) almost daily between 08:00 and 10:00 h by an artificial vagina and evaluated for volume of ejaculate, spermatozoa motility and concentration by standard procedures. Analysis of data from a total of 128-days was performed according to the Fast Fourier Transform Technique (FFT). Statistically significant periods of 7-day were demonstrated for volume, motility, and spermatozoa concentration. Circaseptan rhythms and, particularly, the circannual rhythm (already described in a previous publication) are probably related to ecological diversity and reproductive strategies. 相似文献
67.
MR structural T1-weighted imaging using high field systems (>3T) is severely hampered by the existing large transmit field inhomogeneities. New sequences have been developed to better cope with such nuisances. In this work we show the potential of a recently proposed sequence, the MP2RAGE, to obtain improved grey white matter contrast with respect to conventional T1-w protocols, allowing for a better visualization of thalamic nuclei and different white matter bundles in the brain stem. Furthermore, the possibility to obtain high spatial resolution (0.65 mm isotropic) R1 maps fully independent of the transmit field inhomogeneities in clinical acceptable time is demonstrated. In this high resolution R1 maps it was possible to clearly observe varying properties of cortical grey matter throughout the cortex and observe different hippocampus fields with variations of intensity that correlate with known myelin concentration variations. 相似文献
68.
Ana Horta Claudia Nobrega Pedro Amorim-Machado Vitor Coutinho-Teixeira Palmira Barreira-Silva Susana Boavida Patrício Costa Rui Sarmento-Castro António Gil Castro Margarida Correia-Neves 《PloS one》2013,8(2)
CD4+ regulatory T cells (Tregs) are essential for the maintenance of the immune system''s equilibrium, by dampening the activation of potential auto-reactive T cells and avoiding excessive immune activation. To correctly perform their function, Tregs must be maintained at the right proportion with respect to effector T cells. Since this equilibrium is frequently disrupted in individuals infected with the human immunodeficiency virus (HIV), we hypothesize that its deregulation could hamper immune reconstitution in patients with poor CD4+ T cell recovery under highly active antiretroviral therapy (HAART). We analysed Tregs percentages amongst CD4+ T cells in 53 HIV-infected patients under HAART, with suppression of viral replication and distinct levels of immune reconstitution. As controls, 51 healthy individuals were also analysed. We observed that amongst the patients with Nadir values (the lowest CD4+ T cell counts achieved) <200 cells/µL, the individuals with high Tregs percentages (≥10% of total CD4+ T cells) had the worse CD4+ T cell reconstitution. In accordance, the well-described direct correlation between the Nadir value and CD4+ T cell reconstitution is clearly more evident in individuals with high Tregs proportions. Furthermore, we observed a strong negative correlation between Tregs percentages and CD4+ T cell recovery among immunological non-responder HIV+ individuals. All together, this work shows that high Tregs frequency is an important factor associated with sub-optimal CD4+ T cell recovery. This is particularly relevant for immunological non-responders with low Nadir values. Our results suggest that the Tregs proportion might be of clinical relevance to define cut-offs for HAART initiation. 相似文献
69.
70.
Herman Kosasih Bachti Alisjahbana Nurhayati Quirijn de Mast Irani F. Rudiman Susana Widjaja Ungke Antonjaya Harli Novriani Nugroho H. Susanto Hadi Jusuf Andre van der Ven Charmagne G. Beckett Patrick J. Blair Timothy H. Burgess Maya Williams Kevin R. Porter 《PLoS neglected tropical diseases》2016,10(2)