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71.
72.
de Lima RS Daher RF Gonçalves LS Rossi DA do Amaral Júnior AT Pereira MG Lédo FJ 《Genetics and molecular research : GMR》2011,10(3):1304-1313
Considering the expected genetic variability of elephant grass (Pennisetum purpureum), due to its cultivation in different continents, we characterized and estimated the genetic divergences between 46 accessions of elephant grass with different edaphoclimatic adaptations, using RAPD and ISSR markers. We evaluated, comparatively, the consistency of the information achieved with these markers. Twenty-six RAPD and 25 ISSR primers were employed. The RAPD markers produced 185 bands, 72% of which were polymorphic, with a mean of 5.11 polymorphic bands per primer. The 25 ISSR starters produced 216 bands; 76% were polymorphic, with a mean of 6.56 polymorphic bands per primer. The correlation between the genetic distances achieved by the RAPD and ISSR markers was 0.76, which is highly significant by the Mantel test. Based on UPGMA grouping, considering the point of sudden change, five and six groups were formed for the data from the RAPD and ISSR markers, respectively. These markers provided partially concordant groups, indicating that these techniques can provide consistent information and consequently could be used in studies of genetic diversity among accessions. 相似文献
73.
Marinho CD Martins FJ Amaral SC Amaral Júnior AT Gonçalves LS de Mello MP 《Genetics and molecular research : GMR》2011,10(2):792-809
During the last 20 years, the national production of grains has increased 156.1%; productivity increased 93.8% and there has been an increase of 29.1% in cultivated area. Currently, agribusiness is responsible for 40% of Brazilian exports. Nevertheless, there is little quantitative information on the main plant species of economic interest that have been registered and protected in the Agriculture, Fisheries and Food Supply Ministry (MAPA) by public and private companies, as well as by public-private partnerships. Consequently, we investigated the registry and protection of 27 species of economic interest, including the 15 that are the basis of the Brazilian diet, based on the information available on the site CultivarWeb, of MAPA, for the period from 1998 to August 30, 2010. We also examined the legislation that regulates registration and protection procedures and its implications for plant breeding and plant product development. It was found that the private sector controls 73.1% of the registrations and 53.56% of the protections, while 10.73% of the protections were of material developed overseas. Public-private partnerships contributed little to the development of new cultivars, with 0.5% of the registries and 3.61% of the protections. We conclude that plant protection directed private investment to development of wheat and rice varieties, with the greatest public investments directed to corn and sorghum. After the Cultivar Protection Law was implemented, there was restriction of access to germplasm banks, which could inhibit advances in Brazilian plant breeding programs, indicating a need for revision of this legal barrier. 相似文献
74.
Background and Aims
Schistosomiasis is an intravascular parasitic disease associated with inflammation. Endothelial cells control leukocyte transmigration and vascular permeability being modulated by pro-inflammatory mediators. Recent data have shown that endothelial cells primed in vivo in the course of a disease keep the information in culture. Herein, we evaluated the impact of schistosomiasis on endothelial cell-regulated events in vivo and in vitro.Methodology and Principal Findings
The experimental groups consisted of Schistosoma mansoni-infected and age-matched control mice. In vivo infection caused a marked influx of leukocytes and an increased protein leakage in the peritoneal cavity, characterizing an inflamed vascular and cellular profile. In vitro leukocyte-mesenteric endothelial cell adhesion was higher in cultured cells from infected mice as compared to controls, either in the basal condition or after treatment with the pro-inflammatory cytokine tumor necrosis factor (TNF). Nitric oxide (NO) donation reduced leukocyte adhesion to endothelial cells from control and infected groups; however, in the later group the effect was more pronounced, probably due to a reduced NO production. Inhibition of control endothelial NO synthase (eNOS) increased leukocyte adhesion to a level similar to the one observed in the infected group. Besides, the adhesion of control leukocytes to endothelial cells from infected animals is similar to the result of infected animals, confirming that schistosomiasis alters endothelial cells function. Furthermore, NO production as well as the expression of eNOS were reduced in cultured endothelial cells from infected animals. On the other hand, the expression of its repressor protein, namely caveolin-1, was similar in both control and infected groups.Conclusion/Significance
Schistosomiasis increases vascular permeability and endothelial cell-leukocyte interaction in vivo and in vitro. These effects are partially explained by a reduced eNOS expression. In addition, our data show that the disease primes endothelial cells in vivo, which keep the acquired phenotype in culture. 相似文献75.
Braulio M. de Castro Xavier De Jaeger Cristina Martins-Silva Ricardo D. F. Lima Ernani Amaral Cristiane Menezes Patricia Lima Cintia M. L. Neves Rita G. Pires Thomas W. Gould Ian Welch Christopher Kushmerick Cristina Guatimosim Ivan Izquierdo Martin Cammarota R. Jane Rylett Marcus V. Gomez Marc G. Caron Ronald W. Oppenheim Marco A. M. Prado Vania F. Prado 《Molecular and cellular biology》2009,29(19):5238-5250
The vesicular acetylcholine (ACh) transporter (VAChT) mediates ACh storage by synaptic vesicles. However, the VAChT-independent release of ACh is believed to be important during development. Here we generated VAChT knockout mice and tested the physiological relevance of the VAChT-independent release of ACh. Homozygous VAChT knockout mice died shortly after birth, indicating that VAChT-mediated storage of ACh is essential for life. Indeed, synaptosomes obtained from brains of homozygous knockouts were incapable of releasing ACh in response to depolarization. Surprisingly, electrophysiological recordings at the skeletal-neuromuscular junction show that VAChT knockout mice present spontaneous miniature end-plate potentials with reduced amplitude and frequency, which are likely the result of a passive transport of ACh into synaptic vesicles. Interestingly, VAChT knockouts exhibit substantial increases in amounts of choline acetyltransferase, high-affinity choline transporter, and ACh. However, the development of the neuromuscular junction in these mice is severely affected. Mutant VAChT mice show increases in motoneuron and nerve terminal numbers. End plates are large, nerves exhibit abnormal sprouting, and muscle is necrotic. The abnormalities are similar to those of mice that cannot synthesize ACh due to a lack of choline acetyltransferase. Our results indicate that VAChT is essential to the normal development of motor neurons and the release of ACh.Cholinergic neurotransmission has key functions in life, as it regulates several central and peripheral nervous system outputs. Acetylcholine (ACh) is synthesized in the cytoplasm by the enzyme choline acetyltransferase (ChAT) (16). Choline supplied by the high-affinity choline transporter (CHT1) is required to maintain ACh synthesis (52). A lack of ChAT (4, 35) or the high-affinity choline transporter (21) in genetically modified mice is incompatible with life. ACh plays an important role in wiring the neuromuscular junction (NMJ) during development (38, 43). Embryonic synthesis of ACh is fundamental for the development of proper nerve-muscle patterning at the mammalian NMJ, as ChAT-null mice present aberrant nicotinic ACh receptor (nAChR) localization and increased motoneuron (MN) survival, axonal sprouting, and branching (4, 35).The vesicular ACh transporter (VAChT) exchanges cytoplasmic ACh for two vesicular protons (37, 41). Previously reported electrophysiological studies showed that quantal size is decreased by vesamicol, an inhibitor of VAChT, but only in nerve terminals that have been electrically stimulated (19, 59, 60, 63). VAChT overexpression in developing Xenopus MNs increases both the size and frequency of miniature-end-plate currents (54). In Caenorhabditis elegans, mutations in VAChT affect behavior (65). Moreover, a decrease in VAChT expression has functional consequences for mammals, as mutant mice with a 70% reduction in the expression levels of this transporter (VAChT knockdown [KDHOM] mice) are myasthenic and have cognitive deficits (47). Hence, vesicular transport activity is rate limiting for neurotransmission “in vivo” (18, 47).Exocytosis of synaptic vesicle contents is the predominant mechanism for the regulated secretion of neurotransmitters (55). However, alternative mechanisms of secretion have been proposed (20, 56, 61). Quantal ACh release, comparable to that seen in developing nerve terminals, has been detected in myocytes and fibroblasts in culture, which presumably do not express VAChT (14, 24). More recently, it was found that the correct targeting of Drosophila photoreceptor axons is disrupted in flies with null mutations in ChAT (64). Remarkably, the inactivation of VAChT did not produce the same result (64). The result suggests that the release of ACh during development is not dependent on VAChT, perhaps because it is nonvesicular or because vesicular storage can occur without VAChT.To test if the VAChT-independent secretion of ACh has any physiological role in the mammalian nervous system, we generated a mouse line in which the VAChT gene is deleted. These mice lack the stimulated release of ACh from synaptosomes, die after birth, and show several alterations in neuromuscular wiring consistent with a severe decrease in the cholinergic input to muscles during development. These experiments indicate that VAChT has an important role in maintaining activity-dependent ACh release that supports life and the correct patterning of innervation at the NMJ. 相似文献
76.
Semi-automated recognition of protozoa by image analysis 总被引:2,自引:0,他引:2
A.L. Amaral C. Baptiste M.N. Pons A. Nicolau N. Lima E.C. Ferreira M. Mota H. Vivier 《Biotechnology Techniques》1999,13(2):111-118
A programme was created to semi-automatically analyse protozoal digitised images. Principal Component Analysis technique was used for species identification. After data collection and mathematical treatment, a three-dimensional representation was generated and several protozoa (Opercularia, Colpidium, Tetrahymena, Prorodon, Glaucoma and Trachelophyllum) species could be positively identified. 相似文献
77.
78.
Hugo Teixeira Gomes Patrícia Monah Cunha Bartos Clovis Oliveira Silva Lourdes Isabel Velho do Amaral Jonny Everson Scherwinski-Pereira 《Plant Growth Regulation》2014,74(2):199-208
In this study, the different stages of somatic embryogenesis (SE) of the African oil palm (Elaeis guineensis Jacq.) were characterized biochemically. The total soluble sugars, starch, total free amino acids, and total proteins were extracted, identified and quantified at various stages of embryogenesis: zygotic embryos (initial explants), primary calluses, embryogenic calluses, calluses with pro-embryos, globular embryos, differentiated somatic embryos, and regenerated plants. It was found that at the onset of induction of SE, the level of soluble sugars in the tissues of the explants fell by half. During this period, the total soluble sugars present in the cultures consisted basically of glucose and fructose. In the process of regeneration and maturation, the concentrations of soluble sugars gradually increased, reaching the highest values in the last two stages of development. At this stage, the disaccharide sucrose accounts for more than 80 % of the composition of total soluble sugars in the explants. Compared to starch, we found that the concentrations thereof in developing tissues are inversely proportional to that of soluble sugars virtually throughout embryogenic development. As for free amino acids, we found that after 30 days of induction until formation of the embryogenic calluses, there is an accentuated synthesis of total free amino acids in the explant tissue. In this stage, there was a significant increase in the levels of alanine and serine in the tissues. However, after the formation of the embryogenic calluses, the levels of total free amino acids present in the cultures become stabile and remain constant until the end of cultivation. Similar results were found for total protein, which also showed a significant increase at the onset of induction, undergoing slight changes during the remainder of the cultivation. 相似文献
79.
Renato Sathler-Avelar Danielle Marquete Vitelli-Avelar Armanda Moreira Mattoso-Barbosa Marcelo Perdig?o-de-Oliveira Ronaldo Peres Costa Silvana Maria Elói-Santos Matheus de Souza Gomes Laurence Rodrigues do Amaral Andréa Teixeira-Carvalho Olindo Assis Martins-Filho Edward J. Dick Jr Gene B. Hubbard Jane F. VandeBerg John L. VandeBerg 《PLoS neglected tropical diseases》2016,10(1)
Background
Cynomolgus macaques (Macaca fascicularis) represent a feasible model for research on Chagas disease since natural T. cruzi infection in these primates leads to clinical outcomes similar to those observed in humans. However, it is still unknown whether these clinical similarities are accompanied by equivalent immunological characteristics in the two species. We have performed a detailed immunophenotypic analysis of circulating leukocytes together with systems biology approaches from 15 cynomolgus macaques naturally infected with T. cruzi (CH) presenting the chronic phase of Chagas disease to identify biomarkers that might be useful for clinical investigations.Methods and Findings
Our data established that CH displayed increased expression of CD32+ and CD56+ in monocytes and enhanced frequency of NK Granzyme A+ cells as compared to non-infected controls (NI). Moreover, higher expression of CD54 and HLA-DR by T-cells, especially within the CD8+ subset, was the hallmark of CH. A high level of expression of Granzyme A and Perforin underscored the enhanced cytotoxicity-linked pattern of CD8+ T-lymphocytes from CH. Increased frequency of B-cells with up-regulated expression of Fc-γRII was also observed in CH. Complex and imbricate biomarker networks demonstrated that CH showed a shift towards cross-talk among cells of the adaptive immune system. Systems biology analysis further established monocytes and NK-cell phenotypes and the T-cell activation status, along with the Granzyme A expression by CD8+ T-cells, as the most reliable biomarkers of potential use for clinical applications.Conclusions
Altogether, these findings demonstrated that the similarities in phenotypic features of circulating leukocytes observed in cynomolgus macaques and humans infected with T. cruzi further supports the use of these monkeys in preclinical toxicology and pharmacology studies applied to development and testing of new drugs for Chagas disease. 相似文献80.
Koehler S Cabral JS Whitten WM Williams NH Singer RB Neubig KM Guerra M Souza AP Amaral Mdo C 《Annals of botany》2008,102(4):491-507