|
|
|
| Registros recuperados: 992 | |
|
| |
|
|
| NUÑEZ,MARCO T; GARATE,MARCO A; ARREDONDO,MIGUEL; TAPlA,VICTORIA; MUÑOZ,PATRICIA. |
| Cells tightly regulate iron levels through the activity of iron regulatory proteins (IRPs) that bind to RNA motifs called iron responsive elements (IREs). When cells become iron-depleted, IRPs bind to IREs present in the mRNAs of ferritin and the transferrin receptor, resulting in diminished translation of the ferritin mRNA and increased translation of the transferrin receptor mRNA. Similarly, body iron homeostasis is maintained through the control of intestinal iron absorption. Intestinal epithelia cells sense body iron through the basolateral endocytosis of plasma transferrin. Transterrin endocytosis results in enterocytes whose iron content will depend on the iron saturation of plasma transferrin. Cell iron levels, in turn, inversely correlate with... |
| Tipo: Journal article |
Palavras-chave: Metal ions; Intestinal absorption; Ferritin; Transferrin; Homeostasis. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200013 |
| |
|
| |
|
|
| GAMBOA,JORGE; CACEDA,RICARDO; GAMBOA,ALFREDO; MONGE-C,CARLOS. |
| Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p=0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity. |
| Tipo: Journal article |
Palavras-chave: Carbonic anhydrase; Hypoxia; Polycythemia. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300006 |
| |
|
|
| MORIEL,PATRICIA; PLAVNIK,FRIDA L; ZANELLA,MARIA T; BERTOLAMI,MARCELO C; ABDALLA,DULCINEIA SP. |
| Lipid peroxidation and lipid-derived oxidized products have been implicated in the pathogenesis of a variety of human diseases. To clarify the role of oxidative stress in essential hypertension and hypercholesterolemia the in vitro oxidative susceptibility of LDL, the antioxidant status and the lipid peroxide content of blood plasma were examined in hypercholesterolemic (HC), hypertensive (H), hypercholesterolemic/hypertensive (HH) and normolipidemic/normotensive subjects (N). Plasma ascorbate and lipid-soluble antioxidants were lower, while LDL oxidizability, CE-OOH and TL-OOH were higher in H, HC, and HH groups than in the N group. No difference was observed among groups for PL-OOH and isoprostanes. In summary, the results show that: 1) lipid- and... |
| Tipo: Journal article |
Palavras-chave: Lipoprotein oxidation; Lipid peroxides; Isoprostanes; Antioxidants; Atherosclerosis; Oxidative stress. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200010 |
| |
|
| |
|
|
| MONGE,C C; OSTOJIC,H; AGUILAR,R; CIFUENTES,V. |
| Gray gulls, Larus modestus, nest 1500 m above sea level in northern Chile's Atacama Desert, one of the driest in the world. Their eggshell gas permeability, one third of that found in other Larus species, is an adaptation that reduces water loss, but at the expense of oxygen diffusion into the air cell with resultant hypoxia and reduced metabolic rate. This contrasts with characteristics found in birds nesting at very high altitudes where oxygen diffusion across the egg shell is maximized at the expense of water conservation. The oxygen consumption (MO2) of Larus modestus is 66% that of Larus argentatus; the oxygen conductance (GO2) is equivalent to 48% of that obtained in 5 other bird species. The oxygen partial pressure... |
| Tipo: Journal article |
Palavras-chave: Atacama; Eggshell; Oxygen conductance; Oxygen consumption; Gray gull (Larus modestus). |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300007 |
| |
|
| |
|
| |
|
|
| OSTOJIC,HRVOJ; MONGE-C,CARLOS; CIFUENTES,VERONICA. |
| Blood oxygen affinity and red blood cell properties were measured in three subspecies of genus Bufo: Bufo spinulosus limensis, collected at sea level and at an average day temperature of 20ºC; Bufo spinulosus trifolium, from 3100 m, average day temperature of 15ºC; and Bufo spinulosus flavolineatus, from 4100 m, average day temperature of 10ºC. Electrophoresis of the hemoglobin showed the same component in each of the three subspecies. At 20ºC the blood oxygen affinities (P50) showed small differences between Bufo spinulosus limensis and Bufo spinulosus trifolium, whereas the value for Bufo spinulosus flavolineatus was markedly lower. At 10ºC, the ambient temperature of Bufo spinulosus flavolineatus, the P50 was extremely low compared with the other two... |
| Tipo: Journal article |
Palavras-chave: Adaptations; Altitude; Amphibians; Bufo spinulosus limensis; Bufo spinulosus trifolium; Bufo spinulosus flavolineatus; Hemoglobin affinity; Hematocrits; Oxygen binding; Toads. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000100007 |
| |
|
| |
|
| |
|
| |
|
|
| CROZIER,ALAN; BURNS,JENNIFER; AZIZ,AZLINA A; STEWART,AMANDA J; RABIASZ,HELENA S; JENKINS,GARETH I; EDWARDS,CHRISTINE A; LEAN,MICHAEL EJ. |
| Flavonols are polyphenolic secondary plant metabolites that are present in varying levels in commonly consumed fruits, vegetables and beverages. Flavonols have long held an interest for nutritionists, which has increased following a Dutch study in the early 1990s showing that dietary intake of flavonols was inversely correlated with the incidence of coronary heart disease. The main factors that have hindered workers in the field of flavonol research are (i) the accurate measurement of these compounds in foods and biological samples, and (ii) a dearth of information on their absorption and metabolism. This review aims to highlight the work of the authors in attempting to clarify the situation. The sensitive and selective HPLC procedure to identify and... |
| Tipo: Journal article |
Palavras-chave: Bioavailability; Dietary antioxidants; Flavones; Flavonols; HPLC analysis. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200007 |
| |
|
|
| FUENZALIDA,MARCELA; LEMUS,SUSI; ILLANES,JULIO; MONTIEL,ENRIQUE; ACUÑA,OLGA; LEMUS,DAVID. |
| The structural diversity of the many oligosaccharide chains of surface glycoconjugates renders them likely candidates for modulators of cell-interactions, cellular movements, differentiation, and cellular recognition. A selection of different lectins was used to investigate the appearance of cellular distribution and changes in sugar residues during tooth development in the polyphyodont lizard, Liolaemus gravenhorsti. Lectins from three groups were used: (1) N-acetylgalactosamine specificity: BS-1, PNA, RCA-120; (2) N-acetylglucosamine specificity: ECA; and (3) fucose specificity: UEA 1 and LTA.. Digital images were processed using Scion Image. Grayscale graphics in each image were obtained. The lectins used showed a strong, wide distribution of the... |
| Tipo: Journal article |
Palavras-chave: Sugar residues; Teeth lizard HRP-lectins. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300008 |
| |
|
|
| LOTITO,SILVINA B; FRAGA,CESAR G. |
| We evaluated the interaction between ascorbic acid (AA) and (+)-catechin (CTCH) in potassium phosphate solution, pH 7.4 (PPS) and in human plasma. In both systems, the oxidation was started by adding 2,2-azobis-(2-amidinopropane) clorhidrate (AAPH). The concentrations of AA and CTCH were determined by HPLC using electrochemical detection. In PPS, CTCH was oxidized by AAPH (50 muM), in either the absence or presence of different initial concentrations of AA (25-200 muM). In the presence of AA, CTCH depletion was delayed, an effect that was dependent upon the initial concentration of AA. When 100 muM AA was added after the oxidation had begun, CTCH depletion was arrested for 30 min. The kinetics of AA oxidation by AAPH was also characterized in PPS. AA (100... |
| Tipo: Journal article |
Palavras-chave: Catechins; Antioxidants; Free radicals; Procyanidins. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200015 |
| |
|
|
| URQUIAGA,INES; LEIGHTON,FEDERICO. |
| In recent years there has been a remarkable increment in scientific articles dealing with oxidative stress. Several reasons justify this trend: knowledge about reactive oxygen and nitrogen species metabolism; definition of markers for oxidative damage; evidence linking chronic diseases and oxidative stress; identification of flavonoids and other dietary polyphenol antioxidants present in plant foods as bioactive molecules; and data supporting the idea that health benefits associated with fruits, vegetables and red wine in the diet are probably linked to the polyphenol antioxidants they contain.In this review we examine some of the evidence linking chronic diseases and oxidative stress, the distribution and basic structure of plant polyphenol antioxidants,... |
| Tipo: Journal article |
Palavras-chave: Oxidative stress; Antioxidant; Plant polyphenol; Flavonoid; Chronic diseases; Diet. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200004 |
| |
|
| |
| Registros recuperados: 992 | |
|
|
|
