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"Estudo comparativo do padrão respiratório, movimentação toracoabdominal e ventilação em pacientes portadores de doença pulmonar obstrutiva crônica de graus moderado, grave e indivíduos sadios" ; A comparative study of respiratory pattern, thoracoabdominal motion and ventilation in patients with chronic obstructive pulmonary disease modarate, severe and healthy subjectes

Fernandes, Marcelo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/08/2004 PT
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Avaliamos as mudanças no padrão respiratório, movimento toracoabdominal e ventilação em portadores de DPOC e indivíduos sadios. Estudou-se 45 indivíduos entre 45 e 75 anos conforme o VEF1. Utilizou-se sistemas de pletismografia respiratória por indutância, análise metabólica de gases em posição semi-sentada ao repouso e radiografia de tórax para a mobilidade diafragmática. Os grupos DPOC apresentaram redução do TI, TTOT, aumento do VC/TI, f, VE, das relações VEM/VC, VE/VO2, VE/VCO2 e diminuição da SpO2. Redução da mobilidade do diafragma e aumento da VEM/VC associaram-se à ineficiência da ventilação e a alterações no modelo ventilatório utilizado, sem alterações no movimento toracoabdominal.; We assessed changes in breathing patterns, thoracoabdominal movement and ventilation in COPD sufferers and healthy individuals. Forty-five individuals between 45 and 75 were grouped by FEV1. Inductive plethysmographic equipment, respiratory metabolism measuring (with subject at rest in semi-recumbent position), and radiographic measurement of diaphragm mobility were used. The COPD groups presented reduction in TI and TTOT and increased VT/TI, f, VE, and VD/VT, VE/VO2, VE/VCO2 and decreased SpO2. Reduction in diaphragm mobility and increase of VEM/VC were associated with ventilatory inefficiency and alterations in the ventilatory model used. No alterations in thoracoabdominal movement

Respiratory metabolism of Camponotus rufipes ants: Brood and adults

Takahashi-Del-Bianco, M.; Hebling, MJA; Bueno, O. C.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 529-532
ENG
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The respiratory metabolism of immature forms (eggs, larvae, prepupae and pupae) of Camponotus rufipes (Hymenoptera: Formicidae) was studied at 25 degrees C, using a Warburg respirometer. Mean respiratory rates (mu l O gamma mg(-1) live weight.hr(-1)) for eggs, first instars, second instars, third instars, fourth instars, prepupae, and pupae were respectively: 2.53, 5.07, 1.23, 0.32, 0.22, 0.19 and 0.13. Adult workers with body mass between 20 and 30 mg had a mean respiratory rate of 0.43. The high respiratory rate in first instars probably reflects, besides the size influence, the metabolic costs of differentiation that occurs in this phase. (C) 1998 Published by Elsevier B.V.

Effects of deltamethrin pyrethroid on the respiratory metabolism of the neotropical spirostreptid millipedes Gymnostreptus olivaceus and Plusioporus setiger

Boccardo, Lilian; Fernandes, Marisa N.; Penteado, Carlos H.S.; Jucá-Chagas, Ricardo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 25-28
ENG
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The effects of deltamethrin on the respiratory metabolism of Gymnostreptus olivaceus and Plusioporus setiger were investigated. Acetone solutions corresponding to half the LD50 values, i.e., 20 μg.g-1g for G. olivaceus and 4.40 μg.g-1 for P. setiger, were used. Metabolism was determined with a Warburg respirometer at 25°C. Respirometric measurements were performed 1, 3 and 6 hours after administration of the pyrethroid to the same groups of millipedes. After 24 hours, daily respirometric measurements lasting 1 hour each were made on different millipede groups for a period of 10 days. Significant differences were detected only between the groups treated with the pyrethroid and the two control groups. In G. olivaceus, respiratory rates increased by about 1.65-fold compared to normal immediately after administration of the pyrethroid, followed by a gradual decrease up to 72 hours and a return to normal levels thereafter. In P. setiger the increase was about 1.1-fold compared to normal, with a decrease up to 96 hours and a return to normal thereafter. Although increased oxygen consumption was observed, a detoxification process occurred in both species, so that the possible metabolism of the pyrethroid may justify the low toxicity of deltamethrin for G. olivaceus and P. setiger.

Metabolismo respiratório de bradirrizóbios em processos “in vitro” e simbióticos analisado por PCR quantitativo em tempo real

Moreira, Wellington Marcelo Queixas
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: xv, 81 f. : il.
POR
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Pós-graduação em Microbiologia Agropecuária - FCAV; O Brasil é o segundo maior produtor de soja no mundo, cuja cultura requer o elemento nitrogênio em quantidades elevadas para manutenção do alto teor protéico dos grãos. A entrada de nitrogênio nos sistemas agrícolas pode ocorrer pela adição de fertilizantes nitrogenados ou por processos naturais como a Fixação Biológica do Nitrogênio, que se constitui como supridor de nitrogênio mais viável para a cultura da soja, tanto economicamente como ecologicamente. Este processo ocorre graças à simbiose que ocorre entre esta leguminosa e as bactérias do gênero Bradyrhizobium, resultando na formação de nódulos radiculares onde se dá a obtenção de todo o nitrogênio que a cultura necessita para alta produtividade. A introdução destas bactérias no solo se dá através da utilização de inoculantes comerciais, que incluem as bactérias Bradyrhizobium elkanii e Bradyrhizobium japonicum em sua composição. Aspectos relacionados à formulação e fabricação dos inoculantes comerciais reúnem os fatores mais importantes para a obtenção de um produto de qualidade, obedecendo à legislação vigente. Tendo em vista a análise de qualidade de inoculantes comerciais para soja em diferentes períodos de armazenamento...

Ecophysiology and respiratory metabolism during the germination of Inga sessilis (Vell.) Mart. (Mimosaceae) seeds subjected to hypoxia and anoxia

OKAMOTO,JANETE MAYUMI; JOLY,CARLOS ALFREDO
Fonte: Sociedade Botânica de São Paulo Publicador: Sociedade Botânica de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2000 EN
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This paper presents a study on the respiratory metabolism of germinating seeds of Inga sessilis subjected to normoxia, hypoxia and anoxia. Although it is typical of environments where waterlogging seldom occurs, 40% of its seeds are able to germinate under hypoxia; yet, anoxia periods over 96 h are lethal to the seeds. Ethanol is the main product of the seeds anaerobic metabolism, but the steep increase in lactate after 24 h anoxia or 48 h hypoxia may explain the drop in seed viability.

Involvement of glutamate in the respiratory metabolism of Bradyrhizobium japonicum bacteroids.

Salminen, S O; Streeter, J G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1987 EN
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Bradyrhizobium japonicum bacteroids were isolated anaerobically and supplied with 14C-labeled succinate, malate, aspartate, or glutamate for periods of up to 60 min in the presence of myoglobin to control the O2 concentration. Succinate and malate were absorbed about twice as rapidly as glutamate and aspartate. Conversion of substrate to CO2 was most rapid for malate, followed by succinate, glutamate, and aspartate. When CO2 production was expressed as a proportion of total carbon taken up, malate was still the most rapidly respired substrate, with 68% of the label absorbed converted to CO2. The comparable values for succinate, glutamate, and aspartate were 37, 50, and 38%, respectively. Considering the fate of labeled substrate not respired, greater than 95% of absorbed glutamate remained as glutamate in the bacteroids. In contrast, from 39 to 66% of the absorbed succinate, malate, or aspartate was converted to glutamate. An increase in the rate of CO2 formation from labeled substrates after 20 min appeared to coincide with a maximum accumulation of label in glutamate. The results indicate the presence of a substantial glutamate pool in bacteroids and the involvement of glutamate in the respiratory metabolism of bacteroids.

Respiratory Metabolism of a “Petite Negative” Yeast Schizosaccharomyces pombe 972h−1

Heslot, H.; Goffeau, A.; Louis, C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1970 EN
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56.12%
The respiratory metabolism of Schizosaccharomyces pombe 972h−, a fission, haplontic, “petite negative” yeast, was studied. Glucose and glycerol are good growth substrates and are oxidized under appropriate conditions. l-Lactate, ethanol, malate, and succinate are oxidized but are poor substrates for growth. d-Lactate and pyruvate are neither oxidized nor used for growth. Limited growth was observed under anaerobic conditions. The addition of 0.3% KNO3 to a rich medium relieves the oxygen requirement. A continuous increase of cell respiration during growth on repressive concentration of glucose was observed, suggesting the presence of glucose repression of respiration. Reduced nicotinamide adenine dinucleotide (NADH), succinate, α-glycerophosphate, and ascorbate plus tetramethyl-p-phenylenediamine are oxidized by a mitochondrial fraction. NADH and succinate oxidations are inhibited by antimycin A and NaCN but not by rotenone, suggesting the absence of the phosphorylation site I and the presence of sites II and III. The effects of several mitochondrial inhibitors on growth and respiration indicate that the requirement of an oxidant for growth is related neither to the functioning of the respiratory electron transport chain nor to the formation of respiratory energy. The previously suggested correlations between the nonviability of vegetative “petites” mutants...

AEROBIC RESPIRATORY METABOLISM OF STAPHYLOCOCCUS AUREUS FROM AN INFECTED ANIMAL

Gellenbeck, S. Mercy
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1962 EN
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Gellenbeck, S. Mercy (Catholic University, Washington, D. C.). Aerobic respiratory metabolism of Staphylococcus aureus from an infected animal. J. Bacteriol. 83:450–455. 1962.—The separation of Staphylococcus aureus from the tissue fluids of an infected guinea pig has allowed a comparison of cells (GPR) separated in this manner with the same strain (PR847) grown on an artificial medium.

Fructose 2,6-Bisphosphate and Plant Carbohydrate Metabolism

Stitt, Mark
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1987 EN
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The control of the fructose 2,6-bisphosphate (Fru2,6P2) concentration and its possible role in controlling carbohydrate synthesis and degradation are discussed. This regulator metabolite is involved in the fine tuning of photosynthetic metabolism, and in controlling photosynthetic partitioning, and may also be involved in the response to hormones, wounding, and changing water relations. Study of the mechanisms controlling Fru2,6P2 concentrations could reveal insights into how these responses are mediated. However, the detailed action of Fru2,6P2 requires more attention, especially in respiratory metabolism where the background information about the compartmentation of metabolism between the plastid and cytosol is still inadequate, and the potential role of pyrophosphate has to be clarified.

Experimental Identification and Quantification of Glucose Metabolism in Seven Bacterial Species†

Fuhrer, Tobias; Fischer, Eliane; Sauer, Uwe
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2005 EN
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The structurally conserved and ubiquitous pathways of central carbon metabolism provide building blocks and cofactors for the biosynthesis of cellular macromolecules. The relative uses of pathways and reactions, however, vary widely among species and depend upon conditions, and some are not used at all. Here we identify the network topology of glucose metabolism and its in vivo operation by quantification of intracellular carbon fluxes from 13C tracer experiments. Specifically, we investigated Agrobacterium tumefaciens, two pseudomonads, Sinorhizobium meliloti, Rhodobacter sphaeroides, Zymomonas mobilis, and Paracoccus versutus, which grow on glucose as the sole carbon source, represent fundamentally different metabolic lifestyles (aerobic, anaerobic, photoheterotrophic, and chemoheterotrophic), and are phylogenetically distinct (firmicutes, γ-proteobacteria, and α-proteobacteria). Compared to those of the model bacteria Escherichia coli and Bacillus subtilis, metabolisms of the investigated species differed significantly in several respects: (i) the Entner-Doudoroff pathway was the almost exclusive catabolic route; (ii) the pentose phosphate pathway exhibited exclusively biosynthetic functions, in many cases also requiring flux through the nonoxidative branch; (iii) all aerobes exhibited fully respiratory metabolism without significant overflow metabolism; and (iv) all aerobes used the pyruvate bypass of the malate dehydrogenase reaction to a significant extent. Exclusively...

Studies on the respiratory metabolism of isolated human adipose cells

Galton, David
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1966 EN
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1. Some metabolic characteristics of fat cells isolated from 50 patients were examined. 2. The respiratory activity of human fat cells was of the same order of magnitude as cells obtained from the rat, whether the comparison was based on the molar triglyceride content of cells or the nitrogen content of tissue. 3. There was no difference in the respiratory metabolism of fat cells isolated from three separate age groups: 20–40, 40–60 and 60–80 years. 4. The respiratory activity of human adipose cells was partially inhibited by malonate (0·1m), arsenite (1mm) and iodoacetate (1mm). 5. Oxygen consumption by human adipose cells could not be stimulated by adding glucose or glucose plus palmitic acid to the medium. However, stimulation of oxygen uptake with these substrates was observed after the tissue had been preincubated for 5hr. in a bicarbonate buffer. 6. After the tissue had been preincubated for 5hr., there was a linear relationship between the oxygen uptake by isolated cells and the amount of oleic acid added to the incubation medium. Stimulation of oxygen uptake by oleic acid (0·95μmole/ml.) was dependent on the presence of glucose (5·6mm) in the incubation medium. 7. Of the total [1-14C]palmitic acid metabolized by human adipose cells...

THE EFFECT OF CHANGES IN THE RESPIRATORY METABOLISM UPON GENOME ACTIVITY : A Correlation between Induced Gene Activity and an Increase in Activity of a Respiratory Enzyme

Leenders, Hans J.; Beckers, Pieter J. A.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/11/1972 EN
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The in vitro regression of experimentally induced chromosome puffs was investigated in explanted salivary gland chromosomes of Drosophila hydei. It was observed that the regression of the puffs 2-32A, 2-36A, 2-48C, and 4-81B is accelerated if substrates for the respiratory metabolism are supplied to the cells. A similar effect can be produced by addition of KCN or oligomycin to medium in which intact salivary glands are incubated. The acceleration of puff regression by these substances occurs not only if the puff-inducing stimulus is removed but as well under conditions in which the stimulus is maintained. Regression of the puffs 2-32A, 2-36A, and 4-81B is inhibited if cycloheximide is present in the incubation medium. Chloramphenicol has no effect on puff regression. Measurements on nicotinamide adenine dinucleotide-dehydrogenase activity in homogenates of salivary glands revealed an increase in enzyme activity of 41 %. Maximum increase is attained at 30 min after the induced puffs have reached their maximum size. The increase in enzyme activity does not occur if the glands are kept in a medium containing either actinomycin D or cycloheximide. Chloramphenicol does not inhibit the increase in enzyme activity. The possible relationship between puff activity and its control as a result of changes in the respiratory metabolism is discussed.

Respiratory metabolism of illuminated leaves depends on CO2 and O2 conditions

Tcherkez, Guillaume; Bligny, Richard; Gout, Elizabeth; Mahé, Aline; Hodges, Michael; Cornic, Gabriel
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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Day respiration is the process by which nonphotorespiratory CO2 is produced by illuminated leaves. The biological function of day respiratory metabolism is a major conundrum of plant photosynthesis research: because the rate of CO2 evolution is partly inhibited in the light, it is viewed as either detrimental to plant carbon balance or necessary for photosynthesis operation (e.g., in providing cytoplasmic ATP for sucrose synthesis). Systematic variations in the rate of day respiration under contrasting environmental conditions have been used to elucidate the metabolic rationale of respiration in the light. Using isotopic techniques, we show that both glycolysis and the tricarboxylic acid cycle activities are inversely related to the ambient CO2/O2 ratio: day respiratory metabolism is enhanced under high photorespiratory (low CO2) conditions. Such a relationship also correlates with the dihydroxyacetone phosphate/Glc-6-P ratio, suggesting that photosynthetic products exert a control on day respiration. Thus, day respiration is normally inhibited by phosphoryl (ATP/ADP) and reductive (NADH/NAD) poise but is up-regulated by photorespiration. Such an effect may be related to the need for NH2 transfers during the recovery of photorespiratory cycle intermediates.

Effect of novel phosphoramidate on growth and respiratory metabolism of Paramecium aurelia

Houneida, Benbouzid; Berrebah, H.; Berredjem, M.; Djebar, M. R.
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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45.94%
The continuous increase in the number of new chemicals as well as the discharges of solid and liquid wastes triggered the need for simple and inexpensive bioassays for routine testing. In recent years, there has been increasing development of methods (particularly rapid tests) for testing environmental samples. This paper describes the quick toxic evaluation of a novel synthetic compound: Phosphoramidate derivative B at different concentrations (2, 4 and 8 μM) for 72 h on Paramecium aurelia. We showed that B concentrations affect the growth of Paramecium in concentration- dependent manner; also it decreases the growth rate and increases response percentage in concentration- dependent manner. The value of LC50 obtained for these protozoa was estimated at 4.9693 μM after 24 hours of exposure. The respiratory metabolism of protozoan is perturbed at three concentrations, noting that the oxygen consumption was significantly increased at high concentrations after 18 hours of exposure. The results indicate that the Paramecium toxicity assay could be used as a complementary system to rapidly elucidate the cytotoxic potential of insecticides. The major advantages associated with these tests are: inexpensive, simple, rapid and seem to be attractive alternatives to conventional bioassays

The effect of exogenous calcium on mitochondria, respiratory metabolism enzymes and ion transport in cucumber roots under hypoxia

He, Lizhong; Li, Bin; Lu, Xiaomin; Yuan, Lingyun; Yang, Yanjuan; Yuan, Yinghui; Du, Jing; Guo, Shirong
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 25/08/2015 EN
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Hypoxia induces plant stress, particularly in cucumber plants under hydroponic culture. In plants, calcium is involved in stress signal transmission and growth. The ultimate goal of this study was to shed light on the mechanisms underlying the effects of exogenous calcium on the mitochondrial antioxidant system, the activity of respiratory metabolism enzymes, and ion transport in cucumber (Cucumis sativus L. cv. Jinchun No. 2) roots under hypoxic conditions. Our experiments revealed that exogenous calcium reduces the level of reactive oxygen species (ROS) and increases the activity of antioxidant enzymes in mitochondria under hypoxia. Exogenous calcium also enhances the accumulation of enzymes involved in glycolysis and the tricarboxylic acid (TCA) cycle. We utilized fluorescence and ultrastructural cytochemistry methods to observe that exogenous calcium increases the concentrations of Ca2+ and K+ in root cells by increasing the activity of plasma membrane (PM) H+-ATPase and tonoplast H+-ATPase and H+-PPase. Overall, our results suggest that hypoxic stress has an immediate and substantial effect on roots. Exogenous calcium improves metabolism and ion transport in cucumber roots, thereby increasing hypoxia tolerance in cucumber.

The respiratory metabolism of honey-bee colonies at low temperatures

Free, J.B.; Simpson, J.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
EN; GERMAN
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Honigbienenvölker wurden im Winter aus ihren Stöcken genommen und in galvanisierten Eisenbehältern (Tanks) Temperaturen zwischen 20 und —39° C ausgesetzt. Das Kohlendioxyd der aus den Behältern abgesogenen Luft wurde absorbiert und gewogen. Die CO2-Produktion sank, wenn die Temperatur von 20 auf 10° erniedrigt wurde und stieg bei niederen Temperaturen wieder an. Diese Veränderungen verliefen in umgekehrter Richtung, wenn die Temperatur erhöht wurde.

Some experiments concerning thermal adjustment and respiratory metabolism in insects

Agrell, Ivar
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
EN; ENGLISH
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66.33%
The aim of the investigation is to make a contribution to the problem in what degree the thermal reaction of the respiratory metabolism in insects is qualitatively or quantitatively changed when subjected experimentally for some length of time to variations in the thermal environment. The material under investigation consists of imagines of Stauroderus bicolor CHARP. (Orthoptera), Formica rufa L. (Hymenoptera), Stomoxys calcitrans L. (Diptera), Forficula auricularia L. (Dermaptera), larvae of Ephestia kühniella Z. (Lepidoptera) and Byrrhus pilula L. (Coleoptera), as well as pupae of Phalera bucephala L. (Lepidoptera). The test groups of the different species examined are transferred from an originally uniform environment, i.e. the same limited habitat to three different thermal enviromnents, + 5°C, + 30°C and c:a + 18°C. At more or less regular intervals test animals were taken from these groups and their oxygen consumption and carbon dioxide production were determined at + 18°C. The respiratory exchange at + 18°C is thus used as an index of eventual metabolic changes caused by the change in the thermal environment. The measurements are made with the Thunberg-microrespirometer. In a few cases the respiratory measurements have been supplemented by investigation of the possible change in the resistance to cold. The results of the various experiments are discussed in two parts...

Neurocisticercose experimental: efeito do tratamento anti-helmíntico no metabolismo energético e respiratório de cisticercos

Leandro, Letícia de Almeida
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Medicina Tropical e Saúde Publica (IPTSP); Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Medicina Tropical e Saúde Publica (IPTSP); Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG)
Tipo: Dissertação Formato: application/pdf
POR
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The analysis of the energetic and respiratory metabolism of Taenia crassiceps cysticerci innoculated into the encefalum of female BALB/c mice was performed. After 30 days of infection the mice were treated with low dosages (3.0 and 6.0 mg/kg) of albendazole and praziquantel aiming the observation of the alterations caused by a hostile environment on the parasite's metabolism. The aim of this study was to detect the influence of low dosages of anti-helminthic drugs on the production of organic acids related to the intermediary metabolism (oxaloacetate, malate, fumarate, succinate, citrate and α-ketoglutarate), carbohydrates metabolism (pyruvate, lactate, propionate, oxaloacetate and malate) and fatty acids and proteins catabolism (β-hydroxibutyrate, acetoacetate, acetate, α-ketoglutarate and oxalate) by T. crassiceps cysticerci innoculated into the CNS of BALB/c mice. Regarding the glycolisis, it was possible to detect lactate in all samples which shows that this parasite performs a lactic fermentation. As to the intermediary metabolism it was possible to detect oxaloacetate, citrate, malate, succinate, fumarate and α-ketoglutarate which indicates that the cysticerci may have used the tricarboxilic acid cycle (TCA) to produce energy. However facing the results found the evidences show that the cysticerci used a metabolic pathway denominated reversion of the TCA for energy production which presents as main end products propionate and acetate. There were no significant differences between the groups treated with the anti-helminthic and the control one except that the group treated with 6.0 mg/kg of albendazole presented acetate as main end product of the TCA reversion while the other groups presented propionate. In the groups treated with praziquantel...

NQR1 controls lifespan by regulating the promotion of respiratory metabolism in yeast

Jiménez-Hidalgo, María; Santos-Ocaña, Carlos; Padilla, Sergio; Villalba, José M.; Lopez-Lluch, Guillermo; Martín-Montalvo, Alejandro; Minor, Robin K.; Sinclair, David A.; de Cabo, Rafael; Navas, Plácido
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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The activity and expression of plasma membrane NADH coenzyme Q reductase is increased by calorie restriction (CR) in rodents. Although this effect is well established and is necessary for CR's ability to delay aging, the mechanism is unknown. Here we show that the Saccharomyces cerevisiae homolog, NQR1, resides at the plasma membrane and when overexpressed extends both replicative and chronological lifespan. We show that NQR1 extends replicative lifespan in a SIR2-dependent manner by shifting cells towards respiratory metabolism. Chronological lifespan extension, in contrast, occurs via a SIR2-independent decrease in ethanol production. We conclude that NQR1 is a key mediator of lifespan extension by CR through its effects on yeast metabolism and discuss how these findings could suggest a function for this protein in lifespan extension in mammals.

Temperature-dependent changes in respiration rates and redox poise of the ubiquinone pool in protoplasts and isolated mitochondria of potato leaves

Covey-Crump, Elizabeth M.; Bykova, Natalia V.; Affourtit, Charles; Hoefnagel, Marcel H. N.; Gardestrom, Per; Atkin, Owen
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
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46.12%
In many environments, leaves experience large diurnal variations in temperature. Such short-term changes in temperature are likely to have important implications for respiratory metabolism in leaves. Here, we used intact leaf, protoplasts and isolated mit