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This study examines the effect of asthma severity of children aged 7-17 years and sociodemographic characteristics on the caregiver's quality of life. For parents of asthmatic children, there was a negative correlation between overall asthma severity and quality-of-life score. Measuring parental quality of life enables the development of effective asthma programs.

This paper presents the methodology applied in a research project that studied the global standards of information exchange within the area of power transmission and distribution, allowing for the definition of the state of the art of the theme as well as its application considering technologies already applied by the company AES-Eletropaulo. The specifications needed for the generation of a data integration model, adaptable to radial overhead network at company concession area were researched and defined. The project developed an intermediary connectivity layer, based on the CIM, which enables corporative systems to communicate in a standard way, through the use of integrating technologies. It, therefore, enabled modeling all main subjects of an electrical network in an open way, extensible and non-proprietary in a model that contains classes and attributes of such subjects as well as their relationships. Calculation and planning products adopted by the company were integrated to the technological layer implemented.

The malate-aspartate NADH shuttle in mammalian cells requires the activity of the mitochondrial aspartate-glutamate carrier (AGC). Recently, we identified in man two AGC isoforms, aralar1 and citrin, which are regulated by calcium on the external face of the inner mitochondrial membrane. We have now identified Agc1p as the yeast counterpart of the human AGC. The corresponding gene was overexpressed in bacteria and yeast mitochondria, and the protein was reconstituted in liposomes where it was identified as an aspartate-glutamate transporter from its transport properties. Furthermore, yeast cells lacking Agc1p were unable to grow on acetate and oleic acid, and had reduced levels of valine, ornithine and citrulline; in contrast they grew on ethanol. Expression of the human AGC isoforms can replace the function of Agc1p. However, unlike its human orthologues, yeast Agc1p catalyses both aspartate-glutamate exchange and substrate uniport activities. We conclude that Agc1p performs two metabolic roles in Saccharomyces cerevisiae. On the one hand, it functions as a uniporter to supply the mitochondria with glutamate for nitrogen metabolism and ornithine synthesis. On the other, the Agc1p, as an aspartate-glutamate exchanger, plays a role within the malate-aspartate NADH shuttle which is critical for the growth of yeast on acetate and fatty acids as carbon sources. These results provide strong evidence of the existence of a malate-aspartate NADH shuttle in yeast.

1H and 31P NMR spectra of a variety of phosphorylated myo-inositols have been analyzed using a Bruker WH-360 spectrometer. Proton and phosphorus chemical shifts and coupling constants are reported for myo-inositol 1-phosphate, myo-inositol 2-phosphate, myo-inositol 5-phosphate, myo-inositol 1,2-cyclic phosphate, myo-inositol 1,4-bisphosphate, myo-inositol 1,4,5-trisphosphate, and myo-inositol 1,3,4,5-tetrakisphosphate. These data provide the basis for the chemical identification and characterization of biologically relevant inositol phosphates.

The mechanism of Ca2+ inhibition of carbamylphosphate synthetase I has been investigated using purified enzyme obtained from livers of rats fed a high protein diet. Binding of Mn2+ to the enzyme was measured by EPR techniques at pH 7.8, and Scatchard plots of the data indicated one Mn2+-binding site with a K'd of 13 microM. From competition studies between Mn2+ and Ca2+ or Mg2+ binding, values of 180 microM were obtained for K'd (Mg) and 193 microM for K'd (Ca). A nonlinear least squares curve fitting program was used to calculate the K'm for MgATP2- at the metal-nucleotide binding sites using a simplified rate equation of the enzyme reaction mechanism. Values of 140 and 2420 microM were obtained for K'm (MgATP) at the first and second sites, respectively, at pH 7.8, with a free Mg2+ of 1 mM and other substrates and activators present at saturating concentrations. Variations of the bicarbonate, N-acetylglutamate, and ammonia concentrations in the absence and presence of different amounts of total calcium, from which free Ca2+, free Mg2+, MgATP2-, and CaATP2- concentrations were calculated, permitted values for K'i (CaATP) to be obtained by graphic procedures. Mean values of 375 and 120 microM were obtained for K'i (CaATP) at the first and second sites, respectively. Using the above kinetic constants, a computer model of the enzyme reaction was constructed and tested using two further sets of kinetic data obtained by varying the concentrations of Mg2+, Ca2+, MgATP2-, and CaATP2-. Poor fits were obtained unless the formation of a mixed complex involving CaATP2- competition with MgATP2- at the second metal-nucleotide-binding site was incorporated into the rate equation. Nonlinear least squares curve fitting of both sets of experimental data gave a well determined value of 124 microM for this final CaATP2- inhibitory constant. Sensitivity tests for variation of the primary kinetic constants with the computer model showed that the inhibitory effect of free Ca2+ was weak and that the observed calcium inhibition of carbamylphosphate synthetase can be accounted for primarily by competitive interaction of CaATP2- at the second MgATP2- binding site. With 1 mM free Mg2+ and 5 mM MgATP2-, half-maximal inhibition of enzyme activity was obtained with 0.2 mM CaATP2-.

The mechanism of inhibition of pyruvate carboxylase, pyruvate dehydrogenase, and carbamyl phosphate synthetase induced by alpha-ketoisovalerate metabolism has been investigated in isolated rat hepatocytes incubated with lactate, pyruvate, ammonia, and ornithine as substrates. Half-maximum inhibitions of flux through each of these enzyme steps were obtained with 0.3 mM alpha-ketoisovalerate. The inhibition of pyruvate carboxylase flux by alpha-ketoisovalerate was largely reversed by oleate addition, but pyruvate dehydrogenase flux was inhibited further. Inhibition of flux through pyruvate carboxylase could be attributed mainly to the fall of its allosteric activator, acetyl-CoA, with some additional effect due to inhibition by methylmalonyl-CoA. Tissue acetyl-CoA levels decrease as a result of an inhibition of the active form of pyruvate dehydrogenase. Kinetic studies with the purified pig heart pyruvate dehydrogenase complex showed that methyl-malonyl-CoA, propionyl-CoA, and isobutyryl-CoA were inhibitory, the latter noncompetitive with CoASH with an apparent Ki of 90 microM. The observed inhibition of pyruvate dehydrogenase flux correlated with increases of the acetyl-CoA/CoASH and propionyl-CoA/CoASH ratios and isobutyryl-CoA levels, while increases of the mitochondrial NADH/NAD+ ratio explained differences between the effects of alpha-ketoisovalerate and propionate. Carbamyl phosphate synthetase I purified from rat liver was shown to be inhibited directly by methylmalonyl-CoA (apparent Ki of 5 mM). Inhibition of flux through carbamyl phosphate synthetase during alpha-ketoisovalerate metabolism could be attributed both to a direct inhibitory effect of methyl-malonyl-CoA and to a diminished activation by N-acetylglutamate. Direct effects of various acyl-CoA metabolites on these key enzymes may explain symptoms of hypoglycemia and hyperammonemia observed in patients with inherited disorders of organic acid metabolism.

Carbon-13 (13C) high-resolution magic angle spinning (HR-MAS) spectroscopy was used to investigate the neuroglial coupling mechanisms underlying appetite regulation in the brain of C57BL/6J mice metabolizing [1-13C]glucose. Control fed or overnight fasted mice received [1-13C]glucose (20 μmol/g intraperitoneally [i.p.]), 15 min prior to brain fixation by focused microwaves. The hypothalamic region was dissected from the rest of the brain and 13C HR-MAS spectra were obtained from both biopsies. Fasting resulted in a significant increase in hypothalamic [3-13C]lactate and [2-13C]γ-aminobutyric acid (GABA) relative to the remaining brain. Administration of the orexigenic peptide ghrelin (0.3 nmol/g i.p.) did not increase hypothalamic [3-13C] lactate or [2-13C]GABA, suggesting that ghrelin signaling is not sufficient to elicit all the metabolic consequences of hypothalamic activation by fasting. Our results indicate that the hypothalamic regulation of appetite involves, in addition to the well-known neuropeptide signaling, increased neuroglial lactate shuttling and augmented GABA concentrations. © 2009 Wiley-Liss, Inc., Funded by: Spanish Ministry of Education and Science. Grant Numbers: SAF 2008-01327, SAF 2004-03197, NAN 2004-09125-C07-03; Community of Madrid. Grant Number: S-BIO/0179/2006; Medical Research Council (MRC) UK; Numico Research (Germany) and Fellowships from the Fundação para a Ciência e Tecnologia, Portugal. Grant Numbers: SFRH/BD/41348/2007, SFRH/BPD/26881/2006.

In vivo 1H MRS has been widely used to identify the different metabolites present in brain tumors. However, due to the poor resolution of the in vivo spectra, it only allows the detection and the accurate quantification of very few. The HR-MAS (High Resolution Magie Angle Spinning) Magnetic Resonance Spectroscopy has proved to be a useful tool to overcome this problem. The purpose of this work is the study of the relative contributions of the main choline containing compounds (Cho, PC and GPC) to the total choline (tCho) signal and the evaluation of the potential role of these data in the discrimination betwecn low and high grade glioma. Human biopsies of grade II (low grade) and grades III and IV (high grade) astrocytomas were obtained from the neurosurgery department at "La Paz" Hospital. The HR-MAS spectra of the rumor biopsies were acquired on a 500 MHz Bruker AVANCE Spectrometer, at 4°C and 4 kHz spinning rate. Data were acquired with a classical CPMG with an effective echo time of 144 ms. Metabolite assignments were confirmed by 2D-COSY. The relative contributions of Cho, GPC and PC to the tCho were calculated by fitting lorentzian peaks to the corresponding resonances. The statistical analysis was performed using SPSS (SPSS Inc., Chicago, Illinois). The HR-MAS spectra showed a very high resolution, allowing for the individuai analysis of Cho, PC and GPC. The PC/tCho and the GPC/tCho ratios were significantly different between low grade and high grade gliomas, but did not help to discriminate between grade IH and grade IV (Fig. Ib). Also, the scatter plot of all the data showed that no overlapping at all exists for these two ratios between low and high grade, which implies that no false positives would occur when using this variables as markers for diagnosis. We also calculated the tCho/Cr ratio, which is conventionally used in the in vivo spectra analysis since Cho, PC and GPC cannot be distinguished under these conditions. No statistically significant differences were found for the tCho/Cr ratio between low and high grade gliomas, indicating that the individual contributions of PC and GPC to the tCho, rather than the tCho itself, are the specific markers of tumor malignancy.