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601.
Charles R. Warren Ismael Aranda F. Javier Cano 《Metabolomics : Official journal of the Metabolomic Society》2012,8(2):186-200
Past studies of water stress in Eucalyptus spp. generally highlighted the role of fewer than five “important” metabolites, whereas recent metabolomic studies on other
genera have shown tens of compounds are affected. There are currently no metabolite profiling data for responses of stress-tolerant
species to water stress. We used GC–MS metabolite profiling to examine the response of leaf metabolites to a long (2 month)
and severe (Ψpredawn < −2 MPa) water stress in two species of the perennial tree genus Eucalyptus (the mesic Eucalyptus pauciflora and the semi-arid Eucalyptus dumosa). Polar metabolites in leaves were analysed by GC–MS and inorganic ions by capillary electrophoresis. Pressure–volume curves
and metabolite measurements showed that water stress led to more negative osmotic potential and increased total osmotically
active solutes in leaves of both species. Water stress affected around 30–40% of measured metabolites in E. dumosa and 10–15% in E. pauciflora. There were many metabolites that were affected in E. dumosa but not E. pauciflora, and some that had opposite responses in the two species. For example, in E. dumosa there were increases in five acyclic sugar alcohols and four low-abundance carbohydrates that were unaffected by water stress
in E. pauciflora. Re-watering increased osmotic potential and decreased total osmotically active solutes in E. pauciflora, whereas in E. dumosa re-watering led to further decreases in osmotic potential and increases in total osmotically active solutes. This experiment
has added several extra dimensions to previous targeted analyses of water stress responses in Eucalyptus, and highlights that even species that are closely related (e.g. congeners) may respond differently to water stress and re-watering. 相似文献
602.
Samer Alasaad Antonio Sánchez Juan L. García-Mudarra Michael J. Jowers Jesús M. Pérez Juan Alberto Marchal Ismael Romero José A. Garrido-García Ramón C. Soriguer 《European Journal of Wildlife Research》2012,58(1):345-350
A cost-effective, reliable and efficient method of obtaining DNA samples is essential in large-scale genetic analyses. This
study examines the possibility of using a threatened vole species, Microtus cabrerae, as a model for the collection and preservation of faecal samples for subsequent DNA extraction with a protocol based on
the HotSHOT technique. Through the examination of the probability of multi-copies (mitochondrial) and single copy (microsatellite)
loci amplification (including the genotype error) and of the DNA yield (estimated by real-time qPCR), the new protocol was
compared with both the frequently employed methods that successfully use ethanol to preserve faecal samples and with commercial
kit-based DNA extraction. The single-tube HotSHOT-based protocol is a user-friendly, non-polluting, time-saving and inexpensive
method of faeces sample collection, preservation and PCR-quality gDNA preparation. This technique therefore provides researchers
with a new approach that can be employed in high-throughput, noninvasive genetic analyses of wild animal populations. 相似文献
603.
Balanzat AM Hertlein C Apezteguia C Bonvehi P Cámera L Gentile A Rizzo O Gómez-Carrillo M Coronado F Azziz-Baumgartner E Chávez PR Widdowson MA 《PloS one》2012,7(4):e33670
Background
The apparent high number of deaths in Argentina during the 2009 pandemic led to concern that the influenza A H1N1pdm disease was different there. We report the characteristics and risk factors for influenza A H1N1pdm fatalities.Methods
We identified laboratory-confirmed influenza A H1N1pdm fatalities occurring during June-July 2009. Physicians abstracted data on age, sex, time of onset of illness, medical history, clinical presentation at admission, laboratory, treatment, and outcomes using standardize questionnaires. We explored the characteristics of fatalities according to their age and risk group.Results
Of 332 influenza A H1N1pdm fatalities, 226 (68%) were among persons aged <50 years. Acute respiratory failure was the leading cause of death. Of all cases, 249 (75%) had at least one comorbidity as defined by Advisory Committee on Immunization Practices. Obesity was reported in 32% with data and chronic pulmonary disease in 28%. Among the 40 deaths in children aged <5 years, chronic pulmonary disease (42%) and neonatal pathologies (35%) were the most common co-morbidities. Twenty (6%) fatalities were among pregnant or postpartum women of which only 47% had diagnosed co-morbidities. Only 13% of patients received antiviral treatment within 48 hours of symptom onset. None of children aged <5 years or the pregnant women received antivirals within 48 h of symptom onset. As the pandemic progressed, the time from symptom-onset to medical care and to antiviral treatment decreased significantly among case-patients who subsequently died (p<0.001).Conclusion
Persons with co-morbidities, pregnant and who received antivirals late were over-represented among influenza A H1N1pdm deaths in Argentina, though timeliness of antiviral treatment improved during the pandemic. 相似文献604.
Renato Westermeier David J. Pati?o Pedro Murúa Juan C. Quintanilla Juan Correa Alejandro H. Buschmann Ismael Barros 《Journal of applied phycology》2012,24(1):11-20
Different propagation techniques for cultivation of vegetative Gigartina skottsbergii fronds were tested using a system of suspended ropes, to which inoculants were attached. Our results showed that triangular
fragments obtained from the circular G. skottsbergii thalli produced harvestable frond of 800 cm2 after 8 months. In contrast, inoculants of intact juvenile fronds of comparable size needed at least 10 months to reach the
same size. A control experiment with spores developing on an artificial substrate showed that 20 months were needed to reach
a surface of 500 cm2, confirming the superiority of our fragment culture system. A pilot study demonstrated that with a density of six fronds
m−1 of farming line, the proposed system can be economically interesting for local fishermen. 相似文献
605.
606.
Sánchez-Rodríguez SP Münch-Anguiano L Echeverría O Vázquez-Nin G Mora-Pale M Dordick JS Bustos-Jaimes I 《Biochimie》2012,94(3):870-878
Virus-like particles (VLPs) are biological nanoparticles identical to the natural virions, but without genetic material. VLPs are suitable for the analysis of viral infection mechanisms, vaccine production, tissue-specific drug delivery, and as biological nanomaterials. Human parvovirus B19 (B19) infects humans; therefore VLPs derived from this virus have enormous potential in medicine and diagnostics. Current production of self-assembled VLPs derived from B19 is typically carried out in eukaryotic expression systems. However many applications of VLPs require access to its internal core. Consequently, the processes of disassembly and further reassembly of VLPs are critical both for purification of viral proteins, and for encapsulation purposes. Herein we report the in vitro self-assembly of B19 VLPs derived from the recombinant VP2 protein expressed in Escherichia coli and the effects of pH and ionic strength on the assembly process. Our results demonstrate that VP2 is able to form VLPs completely in vitro. At neutral pH, homogeneous VLPs assemble, while at acidic and basic pHs, with low ionic strength, the major assemblies are small intermediates. The in vitro self-assembled VLPs are highly stable at 37 °C, and a significant fraction of particles remain assembled after 30 min at 80 °C. 相似文献
607.
Ismael Sánchez-Jiménez Oriane Hidalgo Miguel ángel Canela Sonja Siljak-Yakovlev Marija Edita ?oli? Joan Vallès Teresa Garnatje 《Plant Systematics and Evolution》2012,298(6):1085-1099
This work focuses on the representatives of genus Echinops (Asteraceae, Cardueae) in the Aegean and Balkan regions, from the perspective of their genome evolution. Chromosome numbers were determined by orcein staining in 14 populations of nine taxa, and DNA contents were assessed by flow cytometry in 24 populations of nine taxa. A molecular phylogeny based on the internal transcribed spacer (ITS) and trnL-trnF and including first sequences for two taxa (Echinops sphaerocephalus subsp. taygeteus and E.?spinosissimus subsp. neumayeri) provided a framework for discussing genome changes. From a methodological point of view, similar C-DNA value estimates were obtained when measuring, for a same population, fresh leaves from adult plants collected in the field and from cultivated seedlings. Conversely, despite giving the appearance of being correct (e.g., low coefficient of variation), genome size assessed using silica gel-preserved material differs significantly from values obtained for the same populations with fresh material. Nevertheless, silica gel-preserved material may still provide rough estimates of genome size for, e.g., inferring ploidy level. Suitable—non-silica gel-based—DNA amounts assessed for 23 populations range from 2C?=?6.52?pg (E.?spinosissimus subsp. neumayeri) to 2C?=?9.37?pg (E.?bannaticus). Chromosome counts were established for the first time for Echinops graecus (2n?=?32), E.?sphaerocephalus subsp. albidus (2n?=?32), E.?sphaerocephalus subsp. taygeteus (2n?=?ca.?30), and E.?spinosissimus subsp. neumayeri (2n?=?28). Genome size and chromosome number are confirmed as crucial parameters for deciphering lineage diversification within the genus Echinops. 相似文献
608.
Diego Ismael Rocha Lorena Melo Vieira Francisco André Ossamu Tanaka Luzimar Campos da Silva Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2012,111(1):69-78
This study aimed to characterize the anatomical events and ultrastructural aspects of direct and indirect in vitro organogenesis in Passiflora edulis. Root explants were cultured on induction medium, supplemented with 4.44 μM 6-benzyladenine. Roots at different stages of development were collected and processed for observation by light microscopy and scanning and transmission electron microscopy. Patterns of direct and indirect regeneration were observed in the explants. During direct organogenesis, the organogenic buds and nodules, formed from meristemoids, originated from the pericycle regions distant from the cut surface. Completely differentiated buds were observed after 20 days of culture. During indirect organogenesis, bud formation occurred via meristemoids at the periphery of the calli, which differentiated from the cortical region of the initial explant. Regardless of the regeneration pattern, the meristemoids had similar ultrastructural characteristics; however, differences were reported in the nuclear shape of the cells of the meristemoids formed directly and indirectly. This study provides important information for enhancing the understanding and characterization of the organogenic process in non-meristematic explants and provides information on the use of roots as explants in genetic transformation protocols for this important tropical species. 相似文献
609.
Valladolid-Acebes I Merino B Principato A Fole A Barbas C Lorenzo MP García A Del Olmo N Ruiz-Gayo M Cano V 《American journal of physiology. Endocrinology and metabolism》2012,302(4):E396-E402
Obesity and high-fat (HF) diets have a deleterious impact on hippocampal function and lead to impaired synaptic plasticity and learning deficits. Because all of these processes need an adequate glutamatergic transmission, we have hypothesized that nutritional imbalance triggered by these diets might eventually concern glutamate (Glu) neural pathways within the hippocampus. Glu is withdrawn from excitatory synapses by specific uptake mechanisms involving neuronal (EAAT-3) and glial (GLT-1, GLAST) transporters, which regulate the time that synaptically released Glu remains in the extracellular space and, consequently, the duration and location of postsynaptic receptor activation. The goal of the present study was to evaluate in mouse hippocampus the effect of a short-term high-fat dietary treatment on 1) Glu uptake kinetics, 2) the density of Glu carriers and Glu-degrading enzymes, 3) the density of Glu receptor subunits, and 4) synaptic transmission and plasticity. Here, we show that HF diet triggers a 50% decrease of the Michaelis-Menten constant together with a 300% increase of the maximal velocity of the uptake process. Glial Glu carriers GLT-1 and GLAST were upregulated in HF mice (32 and 27%, respectively), whereas Glu-degrading enzymes glutamine synthase and GABA-decarboxilase appeared to be downregulated in these animals. In addition, HF diet hippocampus displayed diminished basal synaptic transmission and hindered NMDA-induced long-term depression (NMDA-LTD). This was coincident with a reduced density of the NR2B subunit of NMDA receptors. All of these results are compatible with the development of leptin resistance within the hippocampus. Our data show that HF diets upregulate mechanisms involved in Glu clearance and simultaneously impair Glu metabolism. Neurochemical changes occur concomitantly with impaired basal synaptic transmission and reduced NMDA-LTD. Taken together, our results suggest that HF diets trigger neurochemical changes, leading to a desensitization of NMDA receptors within the hippocampus, which might account for cognitive deficits. 相似文献
610.
Diana Zamora‐Gutirrez Adrian Guzmn Cyndi G. Hernndez‐Coronado Hctor Castillo‐Jurez Francisco Fierro Carlos G. Gutirrez Rafael Bojalil Ana Ma. Rosales‐Torres 《Molecular reproduction and development》2019,86(2):156-165
In the present study, we investigated the temporal relationship between angiogenic and antiangiogenic vascular endothelial growth factor isoforms (VEGFxxxa and VEGFxxxb, respectively), the receptors VEGFR1 and VEGFR2, their soluble forms, and the kinases and the splicing factors regulating the synthesis of VEGF isoforms in healthy and atretic antral follicles. The results show a higher (p < 0.05) messenger RNA (mRNA) expression of VEGF120a, VEGF164a, and VEGF120b in healthy than in atretic follicles, but the mRNA expression of VEGF164b was not detected. The mRNA of serine–arginine protein kinase 1 ( SRPK1) was higher ( p < 0.05) in large healthy follicles than in large atretic follicles. In contrast, atretic follicles had higher mRNA expression of a soluble form of the receptor 2 of VEGF ( sVEGFR2) than healthy follicles ( p < 0.05). Additionally, we observed a positive relationship ( p < 0.05) between SRPK1 and serine–arginine‐rich splicing factor 1 ( SRSF1) with the angiogenic isoforms VEGF120a and VEGF164a and between CDC‐like kinases‐1 ( CLK1) and SRSF6 with the antiangiogenic VEGF120b isoform. Principal components analysis (PCA) resulted in two PC explaining 71% of the variation, which was formed by the VEGF isoforms, the kinases and the splicing factor (PC1) and by the VEGF receptors (PC2). When PC analysis was carried out within follicular health status, there were no differences for PC1 between follicular status, whereas PC2 differed between healthy and atretic follicles. In conclusion, the higher mRNA expression for VEGF120a and VEGF164a, the low expression of sVEGFR2, and absent expression of mRNA for VEGF164b provide evidence of a proangiogenic autocrine milieu to support granulosa cells during follicle development. 相似文献