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221.
222.
Martos A Monterroso B Zorrilla S Reija B Alfonso C Mingorance J Rivas G Jiménez M 《PloS one》2012,7(6):e39829
We have obtained milligram amounts of highly pure Escherichia coli division protein FtsA from inclusion bodies with an optimized purification method that, by overcoming the reluctance of FtsA to be purified, surmounts a bottleneck for the analysis of the molecular basis of FtsA function. Purified FtsA is folded, mostly monomeric and interacts with lipids. The apparent affinity of FtsA binding to the inner membrane is ten-fold higher than to phospholipids, suggesting that inner membrane proteins could modulate FtsA-membrane interactions. Binding of FtsA to lipids and membranes is insensitive to ionic strength, indicating that a net contribution of hydrophobic interactions is involved in the association of FtsA to lipid/membrane structures. 相似文献
223.
Mercedes M. C. Bustamante Darlan Q. de Brito Alessandra R. Kozovits Gustavo Luedemann Thiago R. B. de Mello Alexandre de Siqueira Pinto Cássia B. R. Munhoz Frederico S. C. Takahashi 《Plant Ecology》2012,213(5):795-808
The Brazilian Cerrado is a diversity hotspot due to its high level of endemism and rapid loss of habitats. It is estimated
that the number of herbaceous species is four times higher than that of woody species. Increasing levels of nitrogen additions
to natural ecosystems have been indicated as a determinant of biodiversity loss. We investigated the effects of nutrient additions
on the productivity (aboveground and belowground) and on diversity of the herbaceous-subshrub layer of a Brazilian savanna
(cerrado stricto sensu). The experiment was carried out in the IBGE Ecological Reserve, near Brasília, Brazil. Between 1998
and 2006, N, P, N plus P, or Ca were applied to sixteen 225 m2 plots, arranged in a completely randomized design. Aboveground biomass was compared 1 year after the first fertilization
and 10 years later. Floristic diversity was significantly different (P < 0.01) between the treatments. The highest and lowest species richness were presented in control and NP, respectively. The
addition of P alone or in combination with N induced invasion by Melinis minutiflora (exotic C4 grass). The aboveground biomass of this species was higher in NP and P plots. In the N treatment, Echinolaena inflexa (native C3 grass) presented elevated cover and biomass but M. minutiflora was absent. The invasion by alien species resulted in negative impacts on native grass species. Besides changes in aboveground
biomass, addition of N and P also led, although to a lesser extent, to changes in the root morphology and biomass, but these
responses were modulated by seasonal variation in soil moisture. The results suggest that environmental changes in nutrient
availability can lead to important consequences for diversity and functioning of this savanna where the numerous rare species
have more chance to persist under dystrophic conditions as some species that tend to be dominant would be less competitive. 相似文献
224.
García-Bermúdez M López-Mejías R González-Juanatey C Castañeda S Miranda-Filloy JA Blanco R Fernández-Gutiérrez B Balsa A González-Alvaro I Gómez-Vaquero C Llorca J Martín J González-Gay MA 《DNA and cell biology》2012,31(7):1214-1220
Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased cardiovascular (CV) mortality. Toll-like receptor-4 (TLR4) activates the innate immune response via NF-kB pathway and mitogen-activated protein kinase signaling, leading to expression of proinflammatory cytokines and chemokines. The G allele of TLR4 rs4986790 (+896A>G, Asp299Gly) gene polymorphism has been implicated in reduction of risk of atherosclerosis. In this study, 1481 RA patients fulfilling the 1987 American College of Rheumatology (ACR) criteria were genotyped for the rs4986790 TLR4 variant to determine the influence of this variant in the risk of CV events in these patients. Also, HLA-DRB1 status was determined using molecular based methods. Moreover, potential influence of rs4986790 variant in the development of subclinical atherosclerosis was assessed in a subgroup of RA patients with no history of CV events by the measurement of surrogate markers of subclinical atherosclerosis. No statistically significant differences in allele or genotype frequencies for the rs4986790 variant between RA patients who experienced CV events or not were found. Likewise, no significant association between this gene variant and any of the surrogate markers of subclinical atherosclerosis was found. In summary, results in our study do not support the hypothesis that the rs4986790 (+896A>G, Asp299Gly) TLR4 variant may influence predisposition for subclinical atherosclerosis and clinically evident CV disease in RA patients. 相似文献
225.
226.
Inmaculada Garrido Mercedes García-Sánchez Ilda Casimiro Pedro Joaquin Casero Inmaculada García-Romera Juan Antonio Ocampo Francisco Espinosa 《PloS one》2012,7(9)
The contamination of soils with dry olive-mill residue can represent a serious problem as being an environmental stressor in plants. It has been demonstrated that inoculation of aqueous extract of olive oil-mill residue (ADOR) with saprobe fungi removes some phenolic compounds. In this paper we studied the effect of ADOR uninoculated or inoculated with saprobe fungi in sunflower seedling roots. The germination and root growth, O2·- generation, superoxide dismutase (SOD) and extracellular peroxidases (EC-POXs) activities, and the content of some metabolites involved in the tolerance of stress were tested. The roots germinated in ADOR uninoculated show a decrease in meristem size, resulting in a reduction of the root length and fresh weight, and in the number of layers forming the cortex, but did not alter the dry weight, protein and soluble amino acid content. ADOR caused the decreases in O2·- generation and EC-POX′s activities and protein oxidation, but enhanced SOD activity, lipid peroxidation and proline content. Fluorescence imaging showed that ADOR induced O2·- and H2O2 accumulation in the roots. The increase in SOD and the decrease in EC-POX′s activities might be involved in the enhancement of H2O2 content and lipid peroxidation. Control roots treated with ADOR for 10 min show an oxidative burst. Roots germinated in ADOR inoculated with saprobe fungi partially recovered normal levels of ROS, morphological characteristics and antioxidant activities. These results suggested that treatment with ADOR caused a phytotoxic effect during germination inducing an oxidative stress. The inoculation of ADOR with saprobe fungi limited the stress. 相似文献
227.
Montiel R Solórzano E Díaz N Álvarez-Sandoval BA González-Ruiz M Cañadas MP Simões N Isidro A Malgosa A 《PloS one》2012,7(5):e36371
Ancient DNA (aDNA) analysis can be a useful tool in bacterial disease diagnosis in human remains. However, while the recovery of Mycobacterium spp. has been widely successful, several authors report unsuccessful results regarding ancient treponemal DNA, casting doubts on the usefulness of this technique for the diagnosis of ancient syphilis. Here, we present results from an analysis of four newborn specimens recovered from the crypt of "La Ermita de la Soledad" (XVI-XVII centuries), located in the province of Huelva in the southwest of Spain. We extracted and analyzed aDNA in three independent laboratories, following specific procedures generally practiced in the aDNA field, including cloning of the amplified DNA fragments and sequencing of several clones. This is the most ancient case, reported to date, from which detection of DNA from T. pallidum subspecies pallidum has been successful in more than one individual, and we put forward a hypothesis to explain this result, taking into account the course of the disease in neonate individuals. 相似文献
228.
Luisa Diomede Cristina Soria Margherita Romeo Sofia Giorgetti Loredana Marchese Patrizia Palma Mangione Riccardo Porcari Irene Zorzoli Mario Salmona Vittorio Bellotti Monica Stoppini 《PloS one》2012,7(12)
Availability of living organisms to mimic key step of amyloidogenesis of human protein has become an indispensable tool for our translation approach aiming at filling the deep gap existing between the biophysical and biochemical data obtained in vitro and the pathological features observed in patients. Human β2-microglobulin (β2-m) causes systemic amyloidosis in haemodialysed patients. The structure, misfolding propensity, kinetics of fibrillogenesis and cytotoxicity of this protein, in vitro, have been studied more extensively than for any other globular protein. However, no suitable animal model for β2-m amyloidosis has been so far reported. We have now established and characterized three new transgenic C. elegans strains expressing wild type human β2-m and two highly amyloidogenic isoforms: P32G variant and the truncated form ΔN6 lacking of the 6 N-terminal residues. The expression of human β2-m affects the larval growth of C. elegans and the severity of the damage correlates with the intrinsic propensity to self-aggregate that has been reported in previous in vitro studies. We have no evidence of the formation of amyloid deposits in the body-wall muscles of worms. However, we discovered a strict correlation between the pathological phenotype and the presence of oligomeric species recognized by the A11 antibody. The strains expressing human β2-m exhibit a locomotory defect quantified with the body bends assay. Here we show that tetracyclines can correct this abnormality confirming that these compounds are able to protect a living organism from the proteotoxicity of human β2-m. 相似文献
229.
María Nicolas Mercedes Alvarez Enrique Anel Félix Martínez Santiago Borragán Felipe Martínez-Pastor Paulino de Paz Luis Anel 《European Journal of Wildlife Research》2012,58(1):77-84
Sperm cryopreservation protocols for brown bear (Ursus arctos) require the centrifugation of semen samples to increase sperm concentration and to clean urine in contaminated samples.
We evaluated the effect of centrifugation regimes (time and relative centrifugal force—RCF) on the quantity of sperm recovered
and the quality of post-thawed sperm. Thirteen brown bears were electroejaculated. The ejaculates were diluted 1:1 in Tris–citric
acid–glucose (TCG) extender and centrifuged with different RCF/time combinations: 600×g, 1,200×g and 2,400×g, for 3, 6 or 12 min. After centrifugation, spermatozoa were diluted in TES–Tris–fructose extender with egg yolk and glycerol
(final glycerol concentration of 8%) and frozen in 0.25-mL straws. In the post-thawed semen, motility was assessed by CASA,
and acrosomal status (PNA-FITC), viability (SYBR-14 with propidium iodide) and chromatin status (SCSA) were determined by
flow cytometry. The longest centrifugation time (12 min) significantly decreased some motility parameters. Sperm recovery
significantly decreased in brown bear at 600×g. Our results suggest that brown bear spermatozoa are more sensitive to long centrifugation times than to high RCF. Centrifugation
regimes showed no effects on the post-thawing chromatin status. We recommend preparing the brown bear semen for freezing by
centrifugation 1,200×g or 2,400×g for 6 min, after electroejaculation and dilution 1:1 in TCG extender, since these procedures increase the spermatozoa recovery
without harmful effects on the post-thawed quality of brown bear spermatozoa. 相似文献
230.
M Armayones MA Vilaseca J Cutillas J Fàbrega JJ Fernández M García N Egea M Pousada B Gómez-Zuñiga J Pérez-Payarols R Artuch F Palau M Serrano 《Orphanet journal of rare diseases》2012,7(1):53
ABSTRACT: Web-based interventions are effective on the patient empowerment. Guiametabolica.org constitutes an interface for people involved in inherited metabolic diseases, trying to facilitate access to information and contact with professionals and other patients, offering a platform to develop support groups. Guiametabolica.org is widely considered for Spanish-speaking patients and caregivers with inherited metabolic diseases. Preliminary evaluations show changes in their habits, decrease in their senses of isolation and improvement regarding self-efficacy. Specific inherited metabolic diseases websites, especially participative websites, should be considered as a complement to more traditional clinical approaches. Their contribution lies in patient's general well-being, without interfering with traditional care. 相似文献