845 research outputs found
Aspectos nutricionais e fisiológicos em genótipos de soja com diferentes níveis de tolerância à restrição hídrica.
A fixação biológica de nitrogênio (FBN) é indispensável para a viabilidade da cultura da soja em termos econômicos e ambientais. Entretanto, a ocorrência de veranicos prejudica a cultura e a FBN. O objetivo desse trabalho foi avaliar aspectos nutricionais e fisiológicos em genótipos de soja com capacidade de manter a FBN em condições de restrição hídrica (30% CC), em comparação com a condição normal (70% CC). O experimento foi conduzido em delineamento inteiramente casualizado em esquema fatorial 5 × 2, com sete repetições, com as linhagens R01-581F, R01-416F, R02-1325, com capacidade de manter a FBN em condições de seca, e os padrões CD 215 e BRS 317, sob suprimento adequado de água (70% CC), ou sob restrição hídrica (30% CC) entre 45 e 55 dias. Avaliaram-se os teores de N e K na parte aérea, a taxa fotossintética e transpiratória das plantas, e a concentração de N-ureídos (alantoína + ácido alantóico) nos pecíolos e nódulos. Os genótipos R01-581F, R01-416F e R02-1325 apresentaram os maiores teores de N e K, independente da condição hídrica. A condição de 30% CC não influenciou no teor de K para os genótipos R01-518F, R01-416F e R02-1325. Apenas o genótipo R01-581F não apresentou diminuição da fotossíntese em condição de 30% CC, e teve a maior taxa transpiratória quando submetido à restrição hídrica. A 30% CC os genótipos R02-1325, CD 215 e BRS 317 tiveram aumento da concentração de N-ureídos em pecíolos, e para os nódulos, todos os genótipos aumentaram a concentração de N-ureídos nessa condição.Fertbio
Rosai-Dorfman disease of the colon presented as small solitary polypoid lesion
Rosai-Dorfman disease (RDD) was formerly known as “sinus histiocytosis with massive lymphadenopathy”, and cases involving the gastrointestinal tract are rare. We present a case of pure extranodal RDD, resected as a polypoid lesion in colonoscopic study. The patient was a 62-year old woman with a history of sigmoidectomy for unexplained peritonitis. Microscopic study of the polypoid lesion showed the submucosal mass with histological and immunological features of RDD. The whole body computed tomography revealed neither lymphadenopathy nor tumor-like mass
Endothelial cell apoptosis in chronically obstructed and reperfused pulmonary artery
<p>Abstract</p> <p>Background</p> <p>Endothelial dysfunction is a major complication of pulmonary endarterectomy (PTE) that can lead to pulmonary edema and persistent pulmonary hypertension. We hypothesized that endothelial dysfunction is related to increased endothelial-cell (EC) death.</p> <p>Methods</p> <p>In piglets, the left pulmonary artery (PA) was ligated to induce lung ischemia then reimplanted into the main PA to reperfuse the lung. Animals sacrificed 5 weeks after ligation (n = 5), 2 days after reperfusion (n = 5), or 5 weeks after reperfusion (n = 5) were compared to a sham-operated group (n = 5). PA vasoreactivity was studied and eNOS assayed. EC apoptosis was assessed by TUNEL in the proximal and distal PA and by caspase-3 activity assay in the proximal PA. Gene expression of pro-apoptotic factors (thrombospondin-1 (Thsp-1) and plasminogen activator inhibitor 1 (PAI-1)) and anti-apoptotic factors vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) was investigated by QRT-PCR.</p> <p>Results</p> <p>Endothelium-dependent relaxation was altered 5 weeks after ligation (<it>p </it>= 0.04). The alterations were exacerbated 2 days after reperfusion (p = 0.002) but recovered within 5 weeks after reperfusion. EC apoptosis was increased 5 weeks after PA ligation (<it>p </it>= 0.02), increased further within 2 days after reperfusion (<it>p </it>< 0.0001), and returned to normal within 5 weeks after reperfusion. Whereas VEGF and bFGF expressions remained unchanged, TSP and PAI-1 expressions peaked 5 weeks after ligation (<it>p </it>= 0.001) and returned to normal within 2 days after reperfusion.</p> <p>Conclusion</p> <p>Chronic lung ischemia induces over-expression of pro-apoptotic factors. Lung reperfusion is followed by a dramatic transient increase in EC death that may explain the development of endothelial dysfunction after PE. Anti-apoptotic agents may hold considerable potential for preventing postoperative complications.</p
Dislocation Driven Chromium Precipitation in Fe-9Cr Binary Alloy: A Positron Lifetime Study
The influence of initial heat treatment on anomalous Cr precipitation within
high temperature solubility region in Fe-9Cr alloy has been investigated using
positron lifetime studies. Air-quenched samples with pre-existing dislocations
exhibited a distinct annealing stage in positron lifetime between 800 and 1100
K corresponding to Cr-precipitation. During this stage, Transmission Electron
Microscopy showed fine precipitates of average size 4 nm, dispersed throughout
the sample and from EDS analysis they are found to be Cr-enriched. The
existence of dislocations is found to be responsible for Cr precipitation.Comment: Revised version Submitted to Phys. Rev.
Sigma-phase in Fe-Cr and Fe-V alloy systems and its physical properties
A review is presented on physical properties of the sigma-phase in Fe-Cr and
Fe-V alloy systems as revealed both with experimental -- mostly with the
Mossbauer spectroscopy -- and theoretical methods. In particular, the following
questions relevant to the issue have been addressed: identification of sigma
and determination of its structural properties, kinetics of alpha-to-sigma and
sigma-to-alpha phase transformations, Debye temperature and Fe-partial phonon
density of states, Curie temperature and magnetization, hyperfine fields,
isomer shifts and electric field gradients.Comment: 26 pages, 23 figures and 83 reference
High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor
The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. © 2014 Bill et al
HIPK2 and extrachromosomal histone H2B are separately recruited by Aurora-B for cytokinesis
Cytokinesis, the final phase of cell division, is necessary to form two distinct daughter cells with correct distribution of genomic and cytoplasmic materials. Its failure provokes genetically unstable states, such as tetraploidization and polyploidization, which can contribute to tumorigenesis. Aurora-B kinase controls multiple cytokinetic events, from chromosome condensation to abscission when the midbody is severed. We have previously shown that HIPK2, a kinase involved in DNA damage response and development, localizes at the midbody and contributes to abscission by phosphorylating extrachromosomal histone H2B at Ser14. Of relevance, HIPK2-defective cells do not phosphorylate H2B and do not successfully complete cytokinesis leading to accumulation of binucleated cells, chromosomal instability, and increased tumorigenicity. However, how HIPK2 and H2B are recruited to the midbody during cytokinesis is still unknown. Here, we show that regardless of their direct (H2B) and indirect (HIPK2) binding of chromosomal DNA, both H2B and HIPK2 localize at the midbody independently of nucleic acids. Instead, by using mitotic kinase-specific inhibitors in a spatio-temporal regulated manner, we found that Aurora-B kinase activity is required to recruit both HIPK2 and H2B to the midbody. Molecular characterization showed that Aurora-B directly binds and phosphorylates H2B at Ser32 while indirectly recruits HIPK2 through the central spindle components MgcRacGAP and PRC1. Thus, among different cytokinetic functions, Aurora-B separately recruits HIPK2 and H2B to the midbody and these activities contribute to faithful cytokinesis
Successful Surgical Treatment of a Spontaneous Rupture of the Esophagus Diagnosed Two Days after Onset
Esophageal perforation is a relatively uncommon disease with a high rate of mortality and morbidity. Delay in the diagnosis and treatment occurs in more than 50% of cases, leading to a mortality rate of 40–60%. Primary repair is generally considered the gold standard for patients who present within the first 24 h following perforation of the esophagus. In this paper, we present a case of successful surgical treatment of spontaneous rupture of the esophagus that was diagnosed 2 days after onset. The patient was a 42-year-old man admitted to internal medicine with a diagnosis of pleuritis and complaining of chest and back pain. The next day, computed tomography revealed left-sided pleural effusion and mediastinal emphysema. An esophagogram revealed extravasation of the contrast medium from the lower left esophagus to the mediastinal cavity. These results confirmed a rupture of the esophagus, and an emergency left thoracotomy was performed. The perforation was repaired with a single-layered closure and was covered with elevated great omentum obtained by laparotomy. The patient was discharged 23 days after the first surgery. In conclusion, primary repair surgery must be selected as the best treatment beyond 24 h if the patient's general state was stable and there was no evidence of clinical sepsis
Preferential Amplification of CD8 Effector-T Cells after Transcutaneous Application of an Inactivated Influenza Vaccine: A Randomized Phase I Trial
Background: Current conventional vaccination approaches do not induce potent CD8 T-cell responses for fighting mostly variable viral diseases such as influenza, avian influenza viruses or HIV. Following our recent study on vaccine penetration by targeting of vaccine to human hair follicular ducts surrounded by Langerhans cells, we tested in the first randomized Phase-Ia trial based on hair follicle penetration (namely transcutaneous route) the induction of virus-specific CD8 T cell responses. Methods and Findings: We chose the inactivated influenza vaccine – a conventional licensed tetanus/influenza (TETAGRIP®) vaccine – to compare the safety and immunogenicity of transcutaneous (TC) versus IM immunization in two randomized controlled, multi-center Phase I trials including 24 healthy-volunteers and 12 HIV-infected patients. Vaccination was performed by application of inactivated influenza vaccine according to a standard protocol allowing the opening of the hair duct for the TC route or needle-injection for the IM route. We demonstrated that the safety of the two routes was similar. We showed the superiority of TC application, but not the IM route, to induce a significant increase in influenza-specific CD8 cytokine-producing cells in healthy-volunteers and in HIV-infected patients. However, these routes did not differ significantly for the induction of influenza-specific CD4 responses, and neutralizing antibodies were induced only by the IM route. The CD8 cell response is thus the major immune response observed after TC vaccination. Conclusions: This Phase Ia clinical trial (Manon05) testing an anti-influenza vaccine demonstrated that vaccines designed for antibody induction by the IM route, generate vaccine-specific CD8 T cells when administered transcutaneously. These results underline the necessity of adapting vaccination strategies to control complex infectious diseases when CD8 cellular responses are crucial. Our work opens up a key area for the development of preventive and therapeutic vaccines for diseases in which CD8 cells play a crucial role
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