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1.
Animal ; 15(2): 100088, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33712207

RESUMEN

Crude glycerin (CG) is a biodiesel byproduct that has been tested as an alternative feed additive for use in beef production. After being absorbed, it is used in the liver to produce glucose, an important precursor of intramuscular fat in ruminants. This study aimed to evaluate the effect of CG (439 g/kg glycerol) on the performance and meat quality of crossbred heifers finished in Urochloa brizantha cv. Marandu. Thirty-six heifers with an initial BW of 301.5 ±â€¯23.02 kg were used. They were supplemented for 154 days with the following levels of CG: mineral mixture (without CG), 33.3, 66.6 and 99.9 g/kg CG in the DM of the supplement. Supplement or pasture DM intakes, slaughter BW and carcass traits were not influenced (P > 0.05) by increasing levels of CG. The total fat content of the meat, the vaccenic (18:1 n-7t) and conjugated linoleic acid (18:2 c9-t11) increased with the addition of CG in the diet (P < 0.05). Crude glycerin can be included up to 99.9 g/kg of the total diet without changing the performance of crossbred heifers finished in the tropical pasture.


Asunto(s)
Alimentación Animal , Glicerol , Alimentación Animal/análisis , Animales , Bovinos , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Carne/análisis
2.
Curr Top Microbiol Immunol ; 422: 101-120, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30406867

RESUMEN

Cryptococcus neoformans is a human pathogenic yeast that causes hundreds of thousands of deaths worldwide among susceptible individuals, in particular, HIV+ patients. This yeast has developed several adaptation mechanisms that allow replication within the host. During decades, this yeast has been well known for a very peculiar and unique structure that contributes to virulence, a complex polysaccharide capsule that surrounds the cell wall. In contrast to other fungal pathogens, such as Candida albicans or Aspergillus fumigatus, the role of morphological transitions has not been studied in the virulence of Cryptococcus neoformans since this yeast does not form hyphae during infection. However, in the last years, different groups have described the ability of this fungus to change its size during infection. In particular, Cryptococcus can form "titan cells," which are blastoconidia of an abnormal large size. Since their discovery, there is increasing evidence that these cells contribute, not only to long-term persistence in the host, but they can also actively participate in the development of the disease. Recently, several groups have simultaneously described different media that induce the appearance of titan cells in laboratory conditions. Using these conditions, new inducing factors and signaling pathways involved in this transition have been described. In this article, we will review the main phenotypic features of these cells, factors, and transduction pathways that induce cell growth, and how titan cells contribute to the disease caused by this pathogen.


Asunto(s)
Criptococosis/microbiología , Cryptococcus neoformans/citología , Cryptococcus neoformans/patogenicidad , Pared Celular/metabolismo , Cryptococcus neoformans/crecimiento & desarrollo , Cryptococcus neoformans/metabolismo , Interacciones Huésped-Patógeno , Humanos , Virulencia
3.
Plant Biol (Stuttg) ; 20(5): 870-878, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29762883

RESUMEN

Despite the great diversity of plant growth-promoting bacteria (PGPB) with potential to partially replace the use of N fertilisers in agriculture, few PGPB have been explored for the production of commercial inoculants, reinforcing the importance of identifying positive plant-bacteria interactions. Aiming to better understand the influence of PGPB inoculation in plant development, two PGPB species with distant phylogenetic relationship were inoculated in maize. Maize seeds were inoculated with Bacillus sp. or Azospirillum brasilense. After germination, the plants were subjected to two N treatments: full (N+) and limiting (N-) N supply. Then, anatomical, biometric and physiological analyses were performed. Both PGPB species modified the anatomical pattern of roots, as verified by the higher metaxylem vessel element (MVE) number. Bacillus sp. also increased the MVE area in maize roots. Under N+ conditions, both PGPB decreased leaf protein content and led to development of shorter roots; however, Bacillus sp. increased root and shoot dry weight, whereas A. brasilense increased photosynthesis rate and leaf nitrate content. In plants subjected to N limitation (N-), photosynthesis rate and photosystem II efficiency increased in maize inoculated with Bacillus sp., whilst A. brasilense contained higher ammonium, amino acids and total soluble sugars in leaves, compared to the control. Plant developmental and metabolical patterns were switched by the inoculation, regardless of the inoculant bacterium used, producing similar as well as distinct modifications to the parameters studied. These results indicate that even non-diazotrophic inoculant strains can improve the plant N status as result of the morpho-anatomical and physiological modifications produced by the PGPB.


Asunto(s)
Azospirillum brasilense/metabolismo , Bacillus/metabolismo , Nitrógeno/farmacología , Raíces de Plantas/anatomía & histología , Zea mays/microbiología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Zea mays/crecimiento & desarrollo , Zea mays/metabolismo , Zea mays/fisiología
4.
Braz. j. biol ; 78(2): 289-295, May-Aug. 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-888866

RESUMEN

Abstract This study reports the pathogen Perkinsus beihaiensis in oysters of the genus Crassostrea on the coast of the State of Bahia (Brazil), its prevalence, infection intensity and correlation with salinity. Oysters (n = 240) were collected between October and December 2014 at eight sampling stations between latitudes 13°55'S and 15°42'S. The laboratory procedures included macroscopic analysis, histology, culture in Ray's fluid thioglycollate medium (RFTM), Polymerase Chain Reaction (PCR) and DNA sequencing. PCR and sequencing have been used for the genetic identification of oysters as well. Two species of oysters have been identified: Crassostrea rhizophorae and C. brasiliana. In both oyster species P. beihaiensis was the only Perkinsus species detected. In C. rhizophorae, the average prevalence was 82.8% by histology and 65.2% by RFTM. In C. brasiliana, the prevalences were 70.5% and 35.7%, respectively. The higher prevalence of P. beihaiensis in C. rhizophorae was probably influenced by salinity, with which was positively correlated (r> 0.8). In both oysters, P. beihaiensis was located mainly in the gastric epithelium. The infection was generally mild or moderate, without apparent harm to the hosts, but in cases of severe infection, there was hemocytical reaction and tissue disorganization. The generally high prevalence in the region suggests that oysters should be monitored with respect to this pathogen, especially in growing areas.


Resumo Este estudo relata o patógeno Perkinsus beihaiensis em ostras do gênero Crassostrea no litoral do Estado da Bahia (Brasil), sua prevalência, intensidade de infecção e correlação com a salinidade. As ostras (n = 240) foram coletadas entre outubro e dezembro de 2014 em oito estações amostrais entre as latitudes 13°55'S e 15°42'S. Os procedimentos laboratoriais incluíram análise macroscópica, histologia, cultivo em meio de tioglicolato de Ray (RFTM), reação em cadeia da polimerase (PCR) e sequenciamento de DNA. PCR e sequenciamento foram também utilizados para a identificação genética das ostras. Foram identificadas duas espécies de ostras: Crassostrea rhizophorae e C. brasiliana. Em ambas as espécies, P. beihaiensis foi a única espécie de Perkinsus detectada. Em C. rhizophorae, a prevalência média foi de 82,8% por histologia e de 65,2% por RFTM. Em C. brasiliana, as prevalências foram de 70,5% e 35,7%, respectivamente. A maior prevalência de P. beihaiensis em C. rhizophorae foi provavelmente influenciada pela salinidade, com a qual este apresentou correlação positiva (r>0,8). Em ambas as espécies, P. beihaiensis esteve localizada principalmente no epitélio gástrico. A infecção foi geralmente leve ou moderada, sem danos aparentes aos hospedeiros, mas em casos de infecção severa, houve reação hemocitária e desorganização de tecidos. As prevalências geralmente altas na região sugerem que as ostras devam ser monitoradas com relação a este patógeno, principalmente em áreas de cultivo.


Asunto(s)
Animales , Crassostrea/parasitología , Alveolados/aislamiento & purificación , Alveolados/genética , Alveolados/patogenicidad , Infecciones Protozoarias en Animales/parasitología , Brasil , Reacción en Cadena de la Polimerasa
5.
Braz J Biol ; 78(2): 289-295, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-28832834

RESUMEN

This study reports the pathogen Perkinsus beihaiensis in oysters of the genus Crassostrea on the coast of the State of Bahia (Brazil), its prevalence, infection intensity and correlation with salinity. Oysters (n = 240) were collected between October and December 2014 at eight sampling stations between latitudes 13°55'S and 15°42'S. The laboratory procedures included macroscopic analysis, histology, culture in Ray's fluid thioglycollate medium (RFTM), Polymerase Chain Reaction (PCR) and DNA sequencing. PCR and sequencing have been used for the genetic identification of oysters as well. Two species of oysters have been identified: Crassostrea rhizophorae and C. brasiliana. In both oyster species P. beihaiensis was the only Perkinsus species detected. In C. rhizophorae, the average prevalence was 82.8% by histology and 65.2% by RFTM. In C. brasiliana, the prevalences were 70.5% and 35.7%, respectively. The higher prevalence of P. beihaiensis in C. rhizophorae was probably influenced by salinity, with which was positively correlated (r> 0.8). In both oysters, P. beihaiensis was located mainly in the gastric epithelium. The infection was generally mild or moderate, without apparent harm to the hosts, but in cases of severe infection, there was hemocytical reaction and tissue disorganization. The generally high prevalence in the region suggests that oysters should be monitored with respect to this pathogen, especially in growing areas.


Asunto(s)
Alveolados , Crassostrea/parasitología , Alveolados/genética , Alveolados/aislamiento & purificación , Alveolados/patogenicidad , Animales , Brasil , Reacción en Cadena de la Polimerasa , Infecciones Protozoarias en Animales/parasitología
6.
Plant Biol (Stuttg) ; 19(5): 720-727, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28637094

RESUMEN

The re-composition of deforested environments requires the prior acclimation of seedlings to full sun in nurseries. Seedlings can overcome excess light either through the acclimation of pre-existing fully expanded leaves or through the development of new leaves that are acclimated to the new light environment. Here, we compared the acclimation capacity of mature (MatL, fully expanded at the time of transfer) and newly expanded (NewL, expanded after the light shift) leaves of Guazuma ulmifolia Lam. (Malvaceae) seedlings to high light. The seedlings were initially grown under shade and then transferred to full sunlight. MatL and NewL were used for chlorophyll fluorescence and gas exchange analyses, pigment extraction and morpho-anatomical measurements. After the transfer of seedlings to full sun, the MatL persisted and acclimated to some extent to the new light condition, since they underwent alterations in some morpho-physiological traits and maintained a functional electron transport chain and positive net photosynthesis rate. However, long-term exposure to high light led to chronic photoinhibition in MatL, which could be related to the limited plasticity of leaf morpho-anatomical attributes. However, the NewL showed a high capacity to use the absorbed energy in photochemistry and dissipate excess energy harmlessly, attributes that were favoured by the high structural plasticity exhibited by these leaves. Both the maintenance of mature, photosynthetically active leaves and the production of new leaves with a high capacity to cope with excess energy were important for acclimation of G. ulmifolia seedlings.


Asunto(s)
Aclimatación/fisiología , Luz , Malvaceae/crecimiento & desarrollo , Clorofila/metabolismo , Malvaceae/metabolismo , Malvaceae/efectos de la radiación , Fotosíntesis , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Bosque Lluvioso
7.
Carbohydr Polym ; 157: 1862-1873, 2017 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-27987906

RESUMEN

The growth regulator gibberellic acid (GA3) has several uses in the field, improving germination, plant development, productivity, and the quality of food. This work describes the development of a nanocarrier system for GA3, based on the poly(γ-glutamic acid) (γ-PGA) and chitosan (CS) polymers, Nanoparticles without GA3 (nano-γPGA/CS-GA3) showed colloidal characteristics, with an average size of 117±9nm, PDI of 0.43±0.07, and zeta potential of -29±0.5mV. The encapsulated nanoparticles (nano-γPGA/CS-GA3) presented an average size of 134±9nm, PDI of 0.35±0.05, zeta potential of 27.9±0.5mV, and 61% encapsulation. The images of nanoparticles observed by Transmission and scanning electron microscopy (TEM and SEM) showed a spherical shape of the nanoparticles. The system showed sustained release, with 58% release after 48h. Evaluation of thermal properties using DSC and TGA analyses indicated that there was an interaction between the CS and γ-PGA polymers. In tests using Phaseolus vulgaris seeds, nano-γPGA/CS-GA3 showed high biological activity, enhancing the rate of germination in the first day (50-70%) when compared with free GA3 (10-16%). Encapsulated GA3 was also more efficient than the free hormone in the increase of leaf area and the induction of root development (including the formation of lateral roots). These effects were not observed when seeds were treated with nano-γPGA/CS without GA3. The results demonstrated the considerable potential of nano-γPGA/CS-GA3 for use in agriculture.


Asunto(s)
Quitosano , Portadores de Fármacos , Giberelinas/administración & dosificación , Nanopartículas , Reguladores del Crecimiento de las Plantas/farmacología , Ácido Poliglutámico , Germinación/efectos de los fármacos , Phaseolus/efectos de los fármacos , Semillas/efectos de los fármacos
8.
J Food Prot ; 79(6): 950-5, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27296598

RESUMEN

Poultry products are important in the transmission of zoonotic pathogens, mainly Salmonella. This genus causes millions of foodborne diseases worldwide every year. Cross-contamination by food sources in human cases of salmonellosis and the increase in resistant strains have become important issues. A qualitative and quantitative Salmonella detection method was utilized in a poultry slaughterhouse in São Paulo State, Brazil. We collected 33 samples from different batches of carcasses. Each sample was analyzed at three process points: postbleeding, postdefeathering, and postchilling. A fourth point, retail simulation, was added to simulate retail market storage at 5°C for 72 h. The qualitative methods revealed 100% (33 samples) contamination at postbleeding, 39% (13 samples) contamination at postdefeathering, 58% (19 samples) contamination at postchilling, and 30% (10 samples) contamination at the retail simulation. The quantitative results, determined by the most-probable-number (MPN) technique, ranged from <0.03 to >2,400 MPN/g. We identified 23 Salmonella serovars; the most prevalent were Mbandaka, Senftenberg, and Enteritidis. Resistance to nalidixic acid was significantly more common (P < 0.05) than resistance to other antimicrobial agents. Five multidrug-resistant strains were identified. This study contributes important epidemiological data and demonstrates the need to improve sanitary conditions in slaughterhouses.


Asunto(s)
Pollos , Aves de Corral , Animales , Antibacterianos , Brasil , Contaminación de Alimentos , Humanos , Prevalencia , Salmonella/clasificación
9.
Genet Mol Res ; 14(4): 12062-73, 2015 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-26505353

RESUMEN

Leishmaniasis is an endemic disease present in 98 countries. In Brazil, the northeast region accounts for approximately half of the cases in humans, and has experienced an increased number of positive cases in dogs. In this study, we investigated the epidemiology of canine leishmaniasis in the city of Ilhéus, Bahia, using serological and molecular techniques and evaluated the possible environmental risk factors and associated clinical signs. Blood samples were collected from 560 dogs in urban and peri-urban areas in Ilhéus, northeastern Brazil. Genomic DNA was extracted from the selected animals and subjected to molecular analysis using Leishmania species-specific primers and diagnosis of Trypanosoma cruzi. A total of 54.72% of dogs were positive for Leishmania braziliensis, and animals positive for both Leishmania infantum and T. cruzi were not identified. Hematologic variables were not statistically associated with cases of L. braziliensis. However, the positive animal group showed lower red blood cell and platelet counts and higher levels of urea and serum creatinine. Few dogs presented clinical signs compatible with the presence of Leishmania. Age of more than 2 years and specific hair colors were associated with positive results for L. braziliensis. The geoclimatic characteristics of the region may improve parasite survival, reproduction, and vectors. This may explain the higher rate of dogs identified as positive in this study.


Asunto(s)
Enfermedad de Chagas/veterinaria , Coinfección/veterinaria , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis/veterinaria , Animales , Brasil , Enfermedad de Chagas/epidemiología , Coinfección/epidemiología , Perros , Leishmania braziliensis/genética , Leishmaniasis/epidemiología , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificación
10.
Arq. bras. med. vet. zootec ; 67(1): 181-188, 2/2015. tab
Artículo en Inglés | LILACS | ID: lil-741111

RESUMEN

This experiment was designed to evaluate the effects of the inclusion of detoxified castor bean meal (CM) content on the chemical-bromatological composition, as well as the fermentation characteristics and dry matter losses of sugarcane silage. The treatments consisted of four levels (0, 7, 14 and 21% natural matter) of addition of castor bean meal. The design was completely randomized, with five replicates. The material was ensiled in PVC silos of 50-cm in height and 10-cm in diameter, which were opened after 60 days. The density of fodder maintained in the silos was equal to 750kg of natural matter/m3. In order to quantify the gas and effluent losses, the silos were weighed at the beginning and at the end of the experiment. The addition of castor bean meal has increased the levels of DM and crude protein and reduced the levels of neutral detergent fiber, N-NH3, ethanol, and gas and effluent losses from silages, but did not affect pH values. During ensiling, alcoholic fermentation was controlled with the inclusion of the additive.


O experimento foi desenvolvido para avaliar os efeitos da inclusão de níveis de farelo de mamona destoxificado sobre a composição químico-bromatológica, as características fermentativas e as perdas de matéria seca da silagem de cana-de-açúcar. Os tratamentos consistiam em quatro níveis (0, 7, 14 e 21% da matéria natural) de inclusão do farelo de mamona. O delineamento foi inteiramente ao acaso, com cinco repetições. Foram usados silos de PVC, com 50cm de altura e 10cm de diâmetro, para a produção das silagens, que foram abertos após 60 dias. A densidade de forragem nos silos foi correspondente a 750kg de matéria natural/m3. Os silos foram pesados no início e ao final do período experimental para quantificar as perdas por gases e efluentes. A inclusão de farelo de mamona elevou os teores de MS e proteína bruta e reduziu os teores de fibra em detergente neutro, N-NH3, etanol e as perdas por gases e efluentes das silagens, não ocasionando efeito nos valores de pH. A fermentação alcoólica durante a ensilagem foi controlada com a inclusão do aditivo.


Asunto(s)
Ricinus/química , Saccharum/clasificación , Saccharum/química , Fermentación
11.
Free Radic Res ; 48(12): 1494-504, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25236567

RESUMEN

Beta cell destruction in type 1 diabetes (TID) is associated with cellular oxidative stress and mitochondrial pathway of cell death. The aim of this study was to determine whether oxidative stress and mitochondrial dysfunction are present in T1D model (non-obese diabetic mouse, NOD) and if they are related to the stages of disease development. NOD mice were studied at three stages: non-diabetic, pre-diabetic, and diabetic and compared with age-matched Balb/c mice. Mitochondria respiration rates measured at phosphorylating and resting states in liver and soleus biopsies and in isolated liver mitochondria were similar in NOD and Balb/c mice at the three disease stages. However, NOD liver mitochondria were more susceptible to calcium-induced mitochondrial permeability transition as determined by cyclosporine-A-sensitive swelling and by decreased calcium retention capacity in all three stages of diabetes development. Mitochondria H2O2 production rate was higher in non-diabetic, but unaltered in pre-diabetic and diabetic NOD mice. The global cell reactive oxygen species (ROS), but not specific mitochondria ROS production, was significantly increased in NOD lymphomononuclear and stem cells in all disease stages. In addition, marked elevated rates of 2',7'-dichlorodihydrofluorescein (H2DCF) oxidation were observed in pancreatic islets from non-diabetic NOD mice. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and lipidomic approach, we identified oxidized lipid markers in NOD liver mitochondria for each disease stage, most of them being derivatives of diacylglycerols and phospholipids. These results suggest that the cellular oxidative stress precedes the establishment of diabetes and may be the cause of mitochondrial dysfunction that is involved in beta cell death.


Asunto(s)
Enfermedades Autoinmunes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Mitocondrias/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Estrés Oxidativo , Animales , Femenino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Poro de Transición de la Permeabilidad Mitocondrial , Permeabilidad , Especies Reactivas de Oxígeno/metabolismo
12.
Biochim Biophys Acta ; 1831(4): 769-75, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23298460

RESUMEN

AIMS/HYPOTHESIS: Changes in cellular cholesterol level may contribute to beta cell dysfunction. Islets from low density lipoprotein receptor knockout (LDLR(-/-)) mice have higher cholesterol content and secrete less insulin than wild-type (WT) mice. Here, we investigated the association between cholesterol content, insulin secretion and Ca(2+) handling in these islets. METHODS: Isolated islets from both LDLR(-/-) and WT mice were used for measurements of insulin secretion (radioimmunoassay), cholesterol content (fluorimetric assay), cytosolic Ca(2+) level (fura-2AM) and SNARE protein expression (VAMP-2, SNAP-25 and syntaxin-1A). Cholesterol was depleted by incubating the islets with increasing concentrations (0-10mmol/l) of methyl-beta-cyclodextrin (MßCD). RESULTS: The first and second phases of glucose-stimulated insulin secretion (GSIS) were lower in LDLR(-/-) than in WT islets, paralleled by an impairment of Ca(2+) handling in the former. SNAP-25 and VAMP-2, but not syntaxin-1A, were reduced in LDLR(-/-) compared with WT islets. Removal of excess cholesterol from LDLR(-/-) islets normalized glucose- and tolbutamide-induced insulin release. Glucose-stimulated Ca(2+) handling was also normalized in cholesterol-depleted LDLR(-/-) islets. Cholesterol removal from WT islets by 0.1 and 1.0mmol/l MßCD impaired both GSIS and Ca(2+) handling. In addition, at 10mmol/l MßCD WT islet showed a loss of membrane integrity and higher DNA fragmentation. CONCLUSION: Abnormally high (LDLR(-/-) islets) or low cholesterol content (WT islets treated with MßCD) alters both GSIS and Ca(2+) handling. Normalization of cholesterol improves Ca(2+) handling and insulin secretion in LDLR(-/-) islets.


Asunto(s)
Calcio/metabolismo , Colesterol/metabolismo , Glucosa/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Animales , Western Blotting , Técnicas In Vitro , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Ratones , Ratones Noqueados , Receptores de LDL/genética , Receptores de LDL/metabolismo
13.
J Clin Microbiol ; 51(4): 1250-2, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23345296

RESUMEN

CLSI method M27-A3 is not available for use with dimorphic fungi, such as those of the Paracoccidioides genus. In this study, we developed a microdilution method and added the alamarBlue reagent to test the responses of Paracoccidioides brasiliensis and Paracoccidioides lutzii against amphotericin B and itraconazole antifungals. The test proved to be sensitive, practical, and inexpensive and can be used to monitor the activity of low-growth microorganisms and their response to various drugs.


Asunto(s)
Antifúngicos/farmacología , Oxazinas/metabolismo , Paracoccidioides/efectos de los fármacos , Coloración y Etiquetado/métodos , Xantenos/metabolismo , Anfotericina B/farmacología , Humanos , Itraconazol/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/metabolismo
14.
Plant Cell Physiol ; 53(9): 1607-16, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22833666

RESUMEN

Nitrate reductase (NR) activity is necessary for the synthesis of nitric oxide (NO), a key signaling molecule in plants. Here, we investigated the effect of NR deficiency on NO production and phenylpropanoid metabolism of Arabidopsis thaliana leaves. HPLC-mass spectrometry analysis showed that the NR double mutant (nia1 nia2) is deficient in the synthesis of sinapoylmalate (SM), the main phenylpropanoid end-product in wild-type leaves, resulting in accumulation of its precursor sinapoylglucose (SG). While real-time PCR analysis revealed no significant difference at the transcript level, sinapoylglucose:malate sinapoyltransferase (SMT) activity in leaf extracts was reduced in the mutant compared with the wild type. The low levels of SM in nia1 nia2 leaves do not result from the deficient nitrogen incorporation into amino acids, since the recovery of the amino acid content of nia1 nia2 by irrigating the plants with glutamine did not change the metabolic profile of this mutant. In contrast, an increased supply of nitrate stimulated NR activity and NO production, and enhanced SM and decreased SG levels in both genotypes. Nevertheless, sinapic acid esters in nia1 nia2 were not recovered when compared with those detected in the leaves of the wild-type plant. Mutant plants grown in medium supplemented with malate and an NO donor recovered SM to the levels of wild-type leaves. Overall, the results suggest that SMT activity is dependent on the NR-dependent steady-state levels of NO during plant development.


Asunto(s)
Aciltransferasas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Nitrato-Reductasa/metabolismo , Óxido Nítrico/metabolismo , Hojas de la Planta/enzimología , Arabidopsis/efectos de los fármacos , Biocatálisis/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Cinamatos/metabolismo , Ácidos Cumáricos/metabolismo , Activación Enzimática/efectos de los fármacos , Ésteres/metabolismo , Glucósidos/metabolismo , Malatos/metabolismo , Malatos/farmacología , Mutación/genética , Nitratos/metabolismo , Óxido Nítrico/farmacología , Fenilpropionatos/metabolismo , Hojas de la Planta/efectos de los fármacos
15.
Braz J Med Biol Res ; 43(12): 1135-42, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21140099

RESUMEN

We determined the influence of fasting (FAST) and feeding (FED) on cholesteryl ester (CE) flow between high-density lipoproteins (HDL) and plasma apoB-lipoprotein and triacylglycerol (TG)-rich emulsions (EM) prepared with TG-fatty acids (FAs). TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001) and a negative correlation from EM to HDL (r = -041, P = 0.0088). Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.


Asunto(s)
Ésteres del Colesterol/metabolismo , Grasas de la Dieta/metabolismo , Ayuno/sangre , Lipoproteínas HDL/metabolismo , Triglicéridos/metabolismo , Proteínas Portadoras/sangre , Grasas de la Dieta/administración & dosificación , Humanos , Masculino
16.
Braz. j. med. biol. res ; 43(12): 1135-1142, Dec. 2010. ilus, tab
Artículo en Inglés | LILACS | ID: lil-569002

RESUMEN

We determined the influence of fasting (FAST) and feeding (FED) on cholesteryl ester (CE) flow between high-density lipoproteins (HDL) and plasma apoB-lipoprotein and triacylglycerol (TG)-rich emulsions (EM) prepared with TG-fatty acids (FAs). TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18 percent and 14 percent, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001) and a negative correlation from EM to HDL (r = -041, P = 0.0088). Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7 percent, 20.7 percent, and 20 percent, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7 percent, 51.2 percent, and 46.3 percent, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.


Asunto(s)
Humanos , Masculino , Ésteres del Colesterol/metabolismo , Grasas de la Dieta/metabolismo , Ayuno/sangre , Lipoproteínas HDL/metabolismo , Triglicéridos/metabolismo , Proteínas Portadoras/sangre , Grasas de la Dieta/administración & dosificación
18.
Immunobiology ; 215(3): 215-22, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19457571

RESUMEN

Wound healing is a complex phenomenon whose mechanisms are not fully understood. Although inflammatory cells are recruited to the site of the lesion there are no reports concerning the participation of B lymphocytes in tissue repair. As demonstrated in our laboratory, B-1 cells migrate to a non-specific inflammatory focus and differentiate into a phagocyte. It has been reported that BALB/Xid mice are deficient in B-1 cells. Using this model, here we report that BALB/Xid mice have an increased inflammatory response, a delayed wound-healing process, a prominent neutrophilic infiltration of the lesion, and an increased neovascularization of the lesion as compared with BALB/c and BALB/Xid reconstituted with B-1 cells. The infiltration of B-1 cells into the wound was demonstrated. As B-1 cells secret and use interleukin 10 (IL-10) as an autocrine growth factor, the possible participation of this interleukin in the kinetics of wound healing was investigated. Results show that C57/BL6 IL-10 KO mice had an increased inflammatory response when compared with C57/BL6 and C57/BL6 IL-10 KO mice reconstituted with B-1 cells, thus suggesting that the observed effects of B-1 cells in the healing process is mediated by this interleukin. However, the mechanisms by which IL-10 influence these phenomena remain to be uncovered.


Asunto(s)
Subgrupos de Linfocitos B/inmunología , Linfocitos B/inmunología , Cicatrización de Heridas/inmunología , Traslado Adoptivo , Animales , Separación Celular , Citometría de Flujo , Inmunohistoquímica , Inflamación/genética , Inflamación/inmunología , Interleucina-10/genética , Interleucina-10/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Neovascularización Fisiológica/inmunología , Cicatrización de Heridas/genética
19.
J Phys Chem A ; 113(52): 14691-8, 2009 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-20028167

RESUMEN

The main purpose of this paper is to report results of quantum mechanical calculation of the H(2) system using the q-Integral method with correlation corrections to the SCF (Self Consistent Field) wave functions included through the Møller-Plesset second-order perturbation (MP(2)) and Coupled-Cluster (CC) theory. Using the q-Integral method, we evaluated potential energy curves, rovibrational spectroscopy constants, rovibrational spectra, interatomic equilibrium distance and longitudinal static hyper(polarizability). All calculations were carried out through the STO-3G, STO-6G, and double-zeta (DZV) atomic basis set. The q-Integral method was implemented in the source code of the general ab initio quantum chemistry package GAMESS.

20.
Plant Cell Physiol ; 49(7): 1112-21, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18540030

RESUMEN

The nitrate reductase (NR)-defective double mutant of Arabidopsis thaliana (nia1 nia2) has previously been shown to present a low endogenous content of NO in its leaves compared with the wild-type plants. In the present study, we analyzed the effect of NR mutation on floral induction and development of A. thaliana, as NO was recently described as one of the signals involved in the flowering process. The NO fluorescent probes diaminofluorescein-2 diacetate (DAF-2DA) and 1,2-diaminoanthraquinone (1,2-DAA) were used to localize NO production in situ by fluorescence microscopy in the floral structures of A. thaliana during floral development. Data were validated by incubating the intact tissues with DAF-2 and quantifying the DAF-2 triazole by fluorescence spectrometry. The results showed that NO is synthesized in specific cells and tissues in the floral structure and its production increases with floral development until anthesis. In the gynoecium, NO synthesis occurs only in differentiated stigmatic papillae of the floral bud, and, in the stamen, only anthers that are producing pollen grains synthesize NO. Sepals and petals do not show NO production. NR-deficient plants emitted less NO, although they showed the same pattern of NO emission in their floral organs. This mutant blossomed precociously when compared with wild-type plants, as measured by the increased caulinar/rosette leaf number and the decrease in the number of days to bolting and anthesis, and this phenotype seems to result from the markedly reduced NO levels in roots and leaves during vegetative growth. Overall, the results reveal a role for NR in the flowering process.


Asunto(s)
Arabidopsis/enzimología , Arabidopsis/crecimiento & desarrollo , Flores/enzimología , Flores/crecimiento & desarrollo , Nitrato-Reductasa/deficiencia , Óxido Nítrico/biosíntesis , Antraquinonas/metabolismo , Fluoresceína/metabolismo , Mutación/genética , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo
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