Evidence for involvement of Saccharomyces cerevisiae protein kinase C in glucose induction of HXT genes and derepression of SUC2

The PKC1 gene in the yeast Saccharomyces cerevisiae encodes protein kinase C that is known to control a mitogen-activated protein (MAP) kinase cascade consisting of Bck1, Mkk1 and Mkk2, and Mpk1. This cascade affects the cell wall integrity but the phenotype of Pkc1 mutants suggests additional targets which have not yet been identified. We show that a pkc1Δ mutant, as opposed to mutants in the MAP kinase cascade, displays two major defects in the control of carbon metabolism. It shows a delay in the initiation of fermentation upon addition of glucose and a defect in derepression of SUC2 gene after exhaustion of glucose from the medium. After addition of glucose the production of both ethanol and glycerol started very slowly. The V max of glucose transport dropped considerably and Northern blot analysis showed that induction of the HXT1, HXT2 and HXT4 genes was strongly reduced. Growth of the pkc1Δ mutant was absent on glycerol and poor on galactose and raffinose. Oxygen uptake was barely present. Derepression of invertase activity and SUC2 transcription upon transfer of cells from glucose to raffinose was deficient in the pkc1Δ mutant as opposed to the wild-type. Our results suggest an involvement of Pkc1p in the control of carbon metabolism which is not shared by the downstream MAP kinase cascade. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

Hypochlorous acid inhibition by acetoacetate: Implications on neutrophil functions

Type-1 diabetic patients experience hyperketonemia caused by an increase in fatty acid metabolism. Thus, the aim of this study was to measure the effect of ketone bodies as suppressors of oxidizing species produced by stimulated neutrophils. Both acetoacetate and 3-hydroxybutyrate have suppressive effect on the respiratory burst measured by luminol-enhanced chemiluminescence. Through measurements of hypochlorous acid production, using neutrophils or the myeloperoxidase/H2O2/Cl- system, it was found that acetoacetate but not 3-hydroxybutyrate is able to inhibit the generation of this antimicrobial oxidant. The superoxide anion scavenging properties were confirmed by ferricytochrome C reduction and lucigenin-enhanced chemiluminescence assays. However, ketone bodies did not alter the rate of oxygen uptake by stimulated neutrophils, measured with an oxygen electrode. A strong inhibition of the expression of the cytokine IL-8 by cultured neutrophils was also observed; this is discussed with reference to the antioxidant-like property of acetoacetate. © 2004 Pharmaceutical Society of Japan.

Componente lento do V̇O2 em crianças durante exercício pesado de corrida: Análise com base em diferentes modelos matemáticos

The purpose of this study was to identify and quantify the magnitude of the slow component of VO2 (SC) in children during running exercise, performed at heavy intensity domain (75%Δ), using two different mathematical models: a) three-exponential model and; b) ΔVO2 6-3 min. Eight healthy male children (11.92 ± 0.63 years; 44.06 ± 13.01 kg; 146.63 ± 7.25 cm; and sexual maturity levels 1 and 2), not trained, performed in different days the following tests: 1) incremental running treadmill test to determine the peak oxygen uptake (VO2peak) and the lactate threshold (LT); and 2) two transitions from baseline to 75%Δ [75%Δ = LT + 0.75 x (VO2 peak - LT)] for six minutes on treadmill. The SC was determined by two models: a) three-exponential model (Exp3); and b) the VO2 difference between the sixth and the third exercise minute (ΔVO2 6-3min). The SC was expressed as the absolute (ml/min) and percent contribution (%) to the total change in VO 2. The SC values determined by model Exp3 (129.69 ± 75.71 ml/min and 8.4 ± 2.92%) and ΔVO2 6-3 min (68.69 ± 102.54 ml/min and 3.6 ± 7.34%) were significantly different. So, the SC values in children during running exercise performed at heavy intensity domain (75%Δ) are dependent of the analysis model (Exp3 x ΔVO2 6-3 min).

Mecanismo de centralização: Da insuficiência placentária à adaptação circulatória fetal

The application and development of obstetric Dopplervelocimetry provide a basis for the investigation of placental insuf ciency and demonstrate the dynamic behavior of fetal circulation during hypoxia. In clinical practice, assessing hemodynamics in three vascular regions involved in pregnancy, namely the uterine, umbilical and middle cerebral arteries, has become routine. Roughly, the cerebral artery expresses the balance between uterine artery oxygen supply and umbilical artery oxygen uptake. Currently, when such balance is unfavorable, the fetal cardiac reserve is investigated by assessing the venous duct. However, determining and interpreting vascular resistance indexes is not an easy task. The starting point is to know the physiopathology of placental insuf ciency and fetal circulatory adaptation through which Doppler con rmed its role in the assessment of fetal well-being.

Aplicação da espirometria durante teste padrão de exercício progressivo em esteira para avaliação da troca gasosa respiratória de equinos da raça árabe

The current study evaluated equine gas exchange responses through spirometry, by measuring oxygen uptake (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (R) and maximum oxygen uptake (VO2max) of Arabian horses during a standard incremental exercise test performed on a high-speed treadmill. Six clinically healthy Arabian horses were submitted to a standard incremental exercise test, performed on a high-speed treadmill at a 6% slope, and initial speed of 1,8 m.s-1 for 5 minutes, then 4,0 m.s-1 for 3 minutes, 6,0 m.s-1 for 2 minutes and 8,0 m.s-1, 9,0 m.s-1, 10,0 m.s-1 and 11,0 m.s-1 for one minute for each of these speed. The end of the exercise test was defined as the point in which the horse was no longer able to keep pace with the treadmill. Gas exchange was measured through respiratory analyses horse mask on the last 10 seconds at the end of each speed transition and at 1, 2 and 3 minutes after the end of the exercise, defined as experiment moments. During exercise, it was noticed an increase on both VO2 and VCO2 with linear relationship between exercise and speed. Arabian horses VO2max was 114,9 mL.kg-1.min-1. The respiratory exchange ratio increased over 1,0 by the speed of 9,0 m.s-1, indicating the preponderance of the anaerobic metabolism, and remains at a high level on the post-exercise period.

Effects of 12-week overground walking training at ventilatory threshold velocity in type 2 diabetic women

This study analyzed the effects of overground walking training at ventilatory threshold (VT) velocity on glycaemic control, body composition, physical fitness and lipid profile in DM2 women. Nineteen sedentary patients were randomly assigned to a control group (CG; n=10, 55.9±2.2 years) or a trained group (TG; n=9, 53.4±2.3 years). Both groups were subjected to anthropometric measures, a 12-h fasting blood sampling and a graded treadmill exercise test at baseline and after a 12-week period, during which TG followed a training program involving overground walking at VT velocity for 20-60min/session three times/week. Significant group×time interactions (P<0.05) in glycated hemoglobin (HbA1c), body mass, body mass index (BMI), peak oxygen uptake (VO 2peak) and exercise duration were observed as effects of training exercise, whereas intervention did not induced significant changes (P>0.05) in fasting blood glucose, submaximal fitness parameters and lipid profile. Our results suggest that overground walking training at VT velocity improves long term glycaemic control, body composition and exercise capacity, attesting for the relevance of this parameter as an effective strategy for the exercise intensity prescription in DM2 population. © 2011 Elsevier B.V.

Características aeróbias e anaeróbias de mesatenistas brasileiros treinados

O objetivo deste estudo foi determinar, em mesatenistas bem treinados, as aptidões aeróbia e anaeróbia. Participaram do presente estudo oito mesatenistas brasileiros treinados do sexo masculino (18±2 anos). Os sujeitos foram submetidos a um teste incremental específico para determinação do consumo pico de oxigênio (VO2PICO), intensidade associada ao VO2PICO (iVO2PICO) e do ponto de compensação respiratório (PCR) e a dois testes de esforço repetitivo, sendo o teste de RAST e o índice anaeróbio alático (IAA), para determinação dos índices anaeróbios. O VO2PICO correspondeu a 50,5±4,4ml kg-1 min-1 , a iVO2PICO a 52,1±9,6 bolas min-1 e o PCR a 44,9±8,0 bolas min-1. No RAST, a potência pico (PP) e a potência média (PM) relativa corresponderam a 9,0±1,3W kg-1 e 7,0±0,9W kg-1, respectivamente, enquanto que o IAA foi 1,14±0,51 mM/m s-1 . Esses valores de VO2PICO e dos parâmetros anaeróbios quando comparados a valores de outros esportes com raquetes caracterizaram que mesatenistas brasileiros treinados apresentam potência aeróbia moderada e potência anaeróbia é baixa.

Branchial O2 chemoreceptors in Nile tilapia Oreochromis niloticus: Control of cardiorespiratory function in response to hypoxia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energy expenditure during multiple sets of leg press and bench press

The purpose of this study was to quantify energy expenditure (EE) during multiple sets of leg press (LP) and bench press (BP) exercises in 10 males with at least 1 yr of resistance training (RT). The subjects underwent two sessions to determine 1 repetition maximum (1RM) on the BP and LP and one protocol consisting of a warm up and 4 sets for 10 repetitions at 70% 1RM with a 3-min rest period between sets for each exercise. Energy expenditure was calculated as the sum of oxygen uptake (aerobic component), EPOC, and lactate production (anaerobic component). There were no significant differences in EE between exercises for sets 1 to 4 and the total energy expended. However, statistical analysis revealed a significant difference (P<0.05) between exercises in RT economy (BP, 0.0206 ± 0.0044 kcal·kg-1 vs. LP, 0.0051 ± 0.0015 kcal·kg-1). Within exercise comparison showed set 4 was significantly different from sets 1 and 3 for BP, and for LP a significant difference was found between set 4 and sets 1, 2 and 3. Our results point to an increase in EE during multiple sets at 70% 1RM and show that in spite of the difference in muscle mass involved and total work done during each type of exercise, EE was not different due to greater economy during the LP.

Test-retest reliability of a 3-min isokinetic all-out test using two different cadences

Objectives: To investigate the test-retest reliability of mechanical parameters derived from a 3-min isokinetic all-out test, performed at 60 and 100 rpm. Reliability and validity of the peak oxygen uptake derived from 3-min isokinetic all-out test were also tested. Design: 14 healthy male subjects completed an incremental ramp testing and four randomized 3-min isokinetic all-out test (two at 60 rpm and two at 100 rpm). Methods: The absolute and relative reliability of the following parameters were analyzed: peak power, mean power, end power, fatigue index, work performed above end power and peak oxygen uptake. Results: No difference was found between each two sets of data, although there were between-cadence differences for peak power, mean power, end power, and fatigue index. Higher intra-class correlation (ICC) and lower coefficient of variation (CV) were found for end power (ICC = 0.91 and 0.95; CV = 5.6 and 5.7%) and mean power (ICC = 0.97 and 0.98; CV = 2.4 and 3.1%), than for peak power (ICC = 0.81 and 0.84; CV = 8.7 and 10%) and work performed above end power (ICC = 0.79 and 0.84; CV = 7.9 and 10.6%; values reported for 60 rpm and 100 rpm, respectively). High reliability scores were also observed for peak oxygen uptake at both cadences (60 rpm, CV = 3.2%; 100 rpm, CV = 2.3%,) with no difference with the incremental ramp testing peak oxygen uptake. Conclusions: The power profile and peak oxygen uptake of a 3-min isokinetic all-out test are both highly reliable, whether the test is performed at 60 or 100 rpm. Besides, peak oxygen uptake and work performed above end power were not affected by the change in cadence while peak power, mean power, end power, and fatigue index were. © 2013.

Complicações pós-operatórias em cirurgia torácica relacionadas aos índices e testes preditores de risco cirúrgico pré-operatórios

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Papel do polimorfismo da posição -786T>C do gene da sintase do óxido nítrico endotelial (eNOS) na resposta pressórica em mulheres no climatério: efeito do treinamento físico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do treinamento físico e dieta restrita em calorias em mulheres com sobrepeso

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do exercício aeróbio sobre os níveis séricos de leptina em mulheres obesas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da oxidação de covelita (CuS) e molibdenita (MoS2) sintéticas por Acidithiobacillus ferrooxidans

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)