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971.
Penatti EM Barina AE Raju S Li A Kinney HC Commons KG Nattie EE 《Journal of applied physiology (Bethesda, Md. : 1985)》2011,110(2):318-328
Malnutrition during pregnancy adversely affects postnatal forebrain development; its effect upon brain stem development is less certain. To evaluate the role of tryptophan [critical for serotonin (5-HT) synthesis] on brain stem 5-HT and the development of cardiorespiratory function, we fed dams a diet ~45% deficient in tryptophan during gestation and early postnatal life and studied cardiorespiratory variables in the developing pups. Deficient pups were of normal weight at postnatal day (P)5 but weighed less than control pups at P15 and P25 (P < 0.001) and had lower body temperatures at P15 (P < 0.001) and P25 (P < 0.05; females only). Oxygen consumption (Vo(2)) was unaffected. At P15, deficient pups had an altered breathing pattern and slower heart rates. At P25, they had significantly lower ventilation (Ve) and Ve-to-Vo(2) ratios in both air and 7% CO(2). The ventilatory response to CO(2) (% increase in Ve/Vo(2)) was significantly increased at P5 (males) and reduced at P15 and P25 (males and females). Deficient pups had 41-56% less medullary 5-HT (P < 0.01) compared with control pups, without a difference in 5-HT neuronal number. These data indicate important interactions between nutrition, brain stem physiology, and age that are potentially relevant to understanding 5-HT deficiency in the sudden infant death syndrome. 相似文献
972.
Carmen Eliana Peralta Vargas Jesús Mora FernándezJavier Pérez Álvarez 《Revista espa?ola de geriatría y gerontología》2011,46(1):46
A case is presented of an 84 year-old woman who was admitted to the Emergency Department due to an episode of non-calculous acute pancreatitis. In the aetiological study, the presence of a splenic lymphoma was documented, which had a compressive effect on the pancreas. After resolving the symptoms, she was scheduled for a splenectomy with a good technical result. At six months after admission the patient was in an excellent clinical and functional condition. This case highlights the unusual clinical presentation of this haematological disease, and the need to evaluate all the available therapeutic options in selected elderly patients. 相似文献
973.
Pasture soils in the Amazon become unsustainable after a short period of use, typically being replaced by emergent secondary
vegetation (capoeira). The aim of this research was to investigate the photosynthetic capacity and water use in the most common
tree species (Vismia japurensis, Vismia cayennensis, Bellucia grossularioides, Laetia procera, and Goupia glabra) in successional chronosequence. This study was carried out in secondary vegetation area with ages that vary between 1 and
19 years. Responses of gas exchange were determined during different periods of precipitation. The gas exchange decreased
with advancing age of the vegetation (1–19 years), except for G. glabra. Negative relationships of P
Nmax as a function of aging observed for V. japurensis, V. cayennensis, B. grossularioides, and L. procera exhibited r
2 equal to 0.59, 0.42, 0.33, and 0.58, respectively. The species of Vismia showed higher values for photosynthetic parameters in relation to other species across the chronosequence. Overall, there
were differences in gas exchange only for some species between the different periods of precipitation. Therefore, our results
suggest a distinct pattern of photosynthetic responses to species in early succession. Light decrease can exert a decisive
role to reduce the photosynthetic rates in secondary succession species. On the other hand, the results of WUE showed weak
evidence of changes for the species during dry and rainy periods in the abandoned pasture in central Amazonia. 相似文献
974.
Düsman E Berti AP Mariucci RG Lopes NB Vicentini VE 《Radiation and environmental biophysics》2011,50(4):579-584
Iodine-131 (131I) is a radioisotope used for the diagnosis and treatment of thyroidal disorders such as hyperthyroidism and cancer. During
its decay, 131I emits beta particles and gamma rays; its physical half-life is 8 days, and it is accumulated preferentially in the thyroid
tissue. This study aimed to evaluate the cytotoxicity and mutagenicity of diagnostic and therapeutic doses of 131I using bone marrow cells of rats treated in vivo in a test system with a single dose by gavage. Concentrations of 5, 25,
50 and 250 μCi in 1 ml of water were used, and after 24 h, the animals were killed. Also, a concentration of 25 μCi/ml of
water was used, and the animals were killed after 5 days. The results showed that no concentration of 131I was cytotoxic and that all concentrations were mutagenic. As a result, there was no statistically significant difference
detected by the χ2 test in the induction of chromosomal aberrations between the different doses. Thus, the present study demonstrated a significant
increase in chromosomal aberration in bone marrow cells exposed to 131I regardless of the dose or the treatment time. 相似文献
975.
Gonçalves P Gregório I Martel F 《American journal of physiology. Cell physiology》2011,301(5):C984-C994
Colorectal cancer is one of the most common cancers worldwide. Butyrate (BT) plays a key role in colonic epithelium homeostasis. The aim of this work was to investigate the possibility of BT being transported by P-glycoprotein (MDR1), multidrug resistance proteins (MRPs), or breast cancer resistance protein (BCRP). Uptake and efflux of (14)C-BT and (3)H-folic acid were measured in Caco-2, IEC-6, and MDA-MB-231 cell lines. mRNA expression of BCRP was detected by RT-PCR. Cell viability, proliferation, and differentiation were quantified with the lactate dehydrogenase, sulforhodamine B, and alkaline phosphatase activity assays, respectively. In both IEC-6 cells and Caco-2 cells, no evidence was found for the involvement of either MDR1 or MRPs in (14)C-BT efflux from the cells. In contrast, several lines of evidence support the conclusion that BT is a substrate of both rat and human BCRP. Indeed, BCRP inhibitors reduced (14)C-BT efflux in IEC-6 cells, both BT and BCRP inhibitors significantly decreased the efflux of the known BCRP substrate (3)H-folic acid in IEC-6 cells, and BCRP inhibitors reduced (14)C-BT efflux in the BCRP-expressing MDA-MB-231 cell line. In IEC-6 cells, combination of BT with a BCRP inhibitor significantly potentiated the effect of BT on cell proliferation. The results of this study, showing for the first time that BT is a BCRP substrate, are very important in the context of the high levels of BCRP expression in the human colon and the anticarcinogenic and anti-inflammatory role of BT at that level. So, interaction of BT with BCRP and with other BCRP substrates/inhibitors is clearly of major importance. 相似文献
976.
Seminotti B Fernandes CG Leipnitz G Amaral AU Zanatta A Wajner M 《Neurochemical research》2011,36(2):205-214
Lysine (Lys) accumulation in tissues and biological fluids is the biochemical hallmark of patients affected by familial hyperlysinemia
(FH) and other inherited metabolic disorders. In the present study we investigated the effects of acute administration of
Lys on relevant parameters of energy metabolism and oxidative stress in striatum of young rats. We verified that Lys in vivo
intrastriatal injection did not change the citric acid cycle function and creatine kinase activity, but, in contrast, significantly
inhibited synaptic Na+,K+-ATPase activity in striatum prepared 2 and 12 h after injection. Moreover, Lys induced lipid peroxidation and diminished
the concentrations of glutathione 2 h after injection. These effects were prevented by the antioxidant scavengers melatonin
and the combination of α-tocopherol and ascorbic acid. Lys also inhibited glutathione peroxidase activity 12 h after injection.
Therefore it is assumed that inhibition of synaptic Na+,K+-ATPase and oxidative damage caused by brain Lys accumulation may possibly contribute to the neurological manifestations of
FH and other neurometabolic conditions with high concentrations of this amino acid. 相似文献
977.
Renata Stolf-Moreira Eliana G. M. Lemos L��cia Carareto-Alves Jackson Marcondes Selma S. Pereira Amanda A. P. Rolla Rodrigo M. Pereira Norman Neumaier Eliseu Binneck Ricardo V. Abdelnoor Maria C. N. de Oliveira Francismar C. Marcelino Jos�� R. B. Farias Alexandre L. Nepomuceno 《Plant Molecular Biology Reporter》2011,29(1):19-34
978.
Branco AT Dos Santos Ferreira B Lourenço GF Lopes Marques VC Tavares Machado OL Pereira MG Aquino Almeida JC de Souza Filho GA 《Protein and peptide letters》2011,18(7):651-657
β-1,3-glucanases are found in organisms as diverse as plants, animals, bacteria and fungi. In plants, such enzymes are not only associated with defense mechanisms against pathogens, but also play critical roles in physiological and developmental processes. Here we identified a new β-1,3-glucanase in maize seeds, and named it ZmGlucA. Sequence analysis revealed that ZmGlucA belongs to the class A of β-1,3-glucanase, a class related to defense and physiological processes in plants. mRNA and protein assays showed that zmGlucA is expressed exclusively in seeds, and it is differentially regulated during seed development. Additionally, zmGlucA expression is strongly induced in seeds of the mutant dek 827Kpro1, which is defective for embryo and endosperm development. Our data support the idea that ZmGlucA protein is relevant to seed development. 相似文献
979.
Renato S. Gonçalves Patrícia V. Abdelnur Vanessa G. Santos Rosineide C. Simas Marcos N. Eberlin Alviclér Magalhães Eduardo R. Pérez González 《Amino acids》2011,40(1):197-204
Abstract
Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by SNAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition–elimination SNAr mechanism was confirmed by NMR and MS measurements. 相似文献980.
P. M. Paes de Sousa D. Rodrigues C. G. Timóteo M. L. Simões Gonçalves G. W. Pettigrew I. Moura J. J. G. Moura M. M. Correia dos Santos 《Journal of biological inorganic chemistry》2011,16(6):881-888
The activation mechanism of Pseudomonas stutzeri cytochrome c peroxidase (CCP) was probed through the mediated electrochemical catalysis by its physiological electron donor, P. stutzeri cytochrome c-551. A comparative study was carried out, by performing assays with the enzyme in the resting oxidized state as well as in
the mixed-valence activated form, using cyclic voltammetry and a pyrolytic graphite membrane electrode. In the presence of
both the enzyme and hydrogen peroxide, the peak-like signal of cytochrome c-551 is converted into a sigmoidal wave form characteristic of an
\textE\textr \textC\texti¢ {\text{E}}_{\text{r}} {\text{C}}_{\text{i}}^{\prime } catalytic mechanism. An intermolecular electron transfer rate constant of (4 ± 1) × 105 M−1 s−1 was estimated for both forms of the enzyme, as well as a similar Michaelis–Menten constant. These results show that neither
the intermolecular electron transfer nor the catalytic activity is kinetically controlled by the activation mechanism of CCP
in the case of the P. stutzeri enzyme. Direct enzyme catalysis using protein film voltammetry was unsuccessful for the analysis of the activation mechanism,
since P. stutzeri CCP undergoes an undesirable interaction with the pyrolytic graphite surface. This interaction, previously reported for the
Paracoccus pantotrophus CCP, induces the formation of a non-native conformation state of the electron-transferring haem, which has a redox potential
200 mV lower than that of the native state and maintains peroxidatic activity. 相似文献