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| Registros recuperados: 992 | |
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| SOTO,CAROLINA R; ARROYO,JORGE; ALCAYAGA,JULIO. |
| Acetylcholine (ACh), adenosine 5'-triphosphate (ATP) and sodium cyanide (NaCN) activate petrosal ganglion (PG) neurons in vitro, and evoke ventilatory reflexes in situ, which are abolished after bilateral chemosensory denervation. Because in our previous experiments we superfused the isolated PG with solutions free of CO2 /HCO3¯ buffer, we studied its effects on the PG responses evoked in vitro. PGs from adult cats were superfused at a constant pH, with HEPES-supplemented (5 mM) saline with or without CO2 /HCO3¯ (5% / 26.2 mM) buffer, and carotid (sinus) nerve frequency discharge (CN) recorded. Increases in CN evoked by ACh, ATP and NaCN in CO2-free saline were significantly reduced (P<0.05, Wilcoxon test) when CO2 / HCO3¯ was present in the... |
| Tipo: Journal article |
Palavras-chave: Petrosal Ganglion; Carotid sinus nerve; Carbon dioxide; Bicarbonate; Acetylcholine; Adenosine 5'- triphosphate; Cyanide. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000300010 |
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| MÜLLER,ILSE; MEDINA-SELBY,ANGELICA; PALACIOS,JOSE LUIS; MARTINEZ,PATRICIO; OPAZO,PATRICIO; BRUCE,ELSA; MANCILLA,MARTA; VALENZUELA,PABLO; YUDELEVICH,ARTURO; VENEGAS,ALEJANDRO. |
| We have cloned and sequenced ten Helicobacter pylori genes from a Chilean strain (CH-CTX1) including: a cytotoxin VacA fragment, a CagA fragment (A17), a species-specific protein (TsaA), urease subunits (UreA, UreB), a flagellin subunit (FlaB), heat shock proteins (HspA and HspB), adhesin (HpaA) and a lipoprotein (Lpp20). We compared their deduced amino acid sequences with the corresponding sequences from three unrelated H. pylori strains, including fully sequenced strains 26695(UK) and J99(USA), and found that eight of them (UreA, UreB, FlaB, HspA, HspB, Lpp20, TsaA and HpaA) presented more than 97.3% identity. In contrast, VacA partial sequence showed lower identity values (93.2 - 94.9%). Moreover, we found major differences in the A17 region respect to... |
| Tipo: Journal article |
Palavras-chave: Chilean H. pylori strain; PCR-cloned genes; HpaA; VacA; CagA sequences. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000100010 |
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| AYBAR,MANUEL J.; GLAVIC,ALVARO; MAYOR,ROBERTO. |
| The neural crest is induced at the border between the neural plate and the epidermis. A complex set of signals is required for the specification of the crest cells between the epidermis and the neural plate. Here we discuss evidence supporting a model for neural crest induction in which different signals contribute in a sequential order. First, a gradient of bone morphogenic proteins (BMPs) is established in the ectoderm that results in segreggation into neural plate, neural folds and epidermis at increasing levels of BMP activity. Thus, the neural folds are induced at a precise threshold concentration of BMP, but this neural fold has an anterior character. In a second step, these anterior neural folds are transformed into prospective neural crest by... |
| Tipo: Journal article |
Palavras-chave: Neural crest induction BMPs Wnts FGF retinoic acid Notch; Delta. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200018 |
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| OSTOJIC,HRVOJ; CIFUENTES,VERONICA; MONGE,CARLOS. |
| Blood hemoglobin oxygen affinity (P50) was measured in three Andean species and in the laboratory rat (control), all raised near sea level. Chinchilla lanigera (Molina, 1792) has an altitudinal habitat range from low Andean slopes up to 3000 m., while Chinchilla brevicaudata (Waterhouse, 1848) has an altitudinal range from 3000 to 5000 m. The laboratory type guinea pig, wild type guinea pig (Cavia porcellus), (Waterhouse, 1748), and laboratory rat (Rattus norvegicus) were also raised at sea level. The Andean species had high hemoglobin oxygen affinities (low P50) compared with the rat. Chinchilla brevicaudata had a higher affinity than Chinchilla lanigera. The wild type guinea pig had a higher affinity than the laboratory type. As has been shown in other... |
| Tipo: Journal article |
Palavras-chave: Hemoglobin affinity; Rodents; High altitude adaptation. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000100005 |
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| ORTEGA,XIMENA; POLANCO,RUBÉN; CASTAÑEDA,PATRICIA; PEREZ,LUZ M. |
| The development of an effective hypersensitive response (HR) in any plant system relies, not only in their gene composition and expression, but also on an effective and rapid signal transduction system. Lemon seedlings induce the phenylpropanoid pathway, which results in the de novo biosynthesis of the phytoalexin scoparone, as part of the hypersensitive response against Alternaria alternata. In order to elucidate some of the signaling elements that participate in the development of HR in lemon seedlings, we used several compounds that are known as activators or inhibitors of signal transduction elements in plants or in animal cells. Lemon seedlings treated either with cholera toxin or with phorbol 12-myristate 13-acetate (PMA), in the absence of A.... |
| Tipo: Journal article |
Palavras-chave: Citrus limon; Hypersensitive response; Signal transduction. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000300012 |
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| LEIVA-SALCEDO,ELIAS; PEREZ,VIVIANA; ACUÑA-CASTILLO,CLAUDIO; WALTER,ROBIN; SIERRA,FELIPE. |
| Serum levels of T-kininogen increase dramatically as rats approach the end of their lifespan. Stable expression of the protein in Balb/c 3T3 fibroblasts leads to a dramatic inhibition of cell proliferation, as well as inhibition of the ERK signaling pathway. T-kininogen is a potent inhibitor of cysteine proteinases, and we have described that the inhibition of ERK activity occurs, at least in part, via stabilization of the MAP kinase phosphatase, MKP-1. Since fibroblasts are not a physiological target of T-kininogen, we have now purified the protein from rat serum, and used it to assess the effect of T-kininogen on endothelial cells. Adding purified T-kininogen to EAhy 926 hybridoma cells resulted in inhibition of basal ERK activity levels, as estimated... |
| Tipo: Journal article |
Palavras-chave: Aging; Endothelial cells; ERK pathway; Kininogen; Kinins. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200020 |
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| FELIPE BARROS,LUIS; CASTRO,JOEL; BITTNER,CARLA X.. |
| Cell death is preceded by severe disruption of inorganic ion homeostasis. Seconds to minutes after an injury, calcium, protons, sodium, potassium and chloride are exchanged between the cell and its environment. Simultaneously, ions are shifted between membrane compartments inside the cell, whereby mitochondria and endoplasmic reticulum play a crucial role. Depending of the type and severity of injury, two mutually exclusive metastable states can be reached, which predict the final outcome. Cells characterized by large increases in cytosolic [Ca2+], [Na+]; and [Mg2+] swell and die by necrosis; alternatively, cells characterized by high [H+]and low [K+], with normal [Na+] and normal to moderate [Ca2+] increases die by apoptosis. The levels of these ions... |
| Tipo: Journal article |
Palavras-chave: Cell death; Membrane channels; Apoptosis; Necrosis. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200012 |
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| BENDER,FLORENT; MONTOYA,MARGARITA; MONARDES,VIRGINIA; LEYTON,LISETTE; QUEST,ANDREW F.G.. |
| Caveolae are small, flask-shaped invaginations of the plasma membrane present on a large number of mammalian cells. Recent results obtained with knock-out mice for the gene caveolin-1 demonstrate that expression of caveolin-1 protein is essential for caveolae formation in vivo. Caveolae are implicated in a wide variety of cellular events including transcytosis, cholesterol trafficking and as cellular centers important in coordinating signalling events. Caveolae share this role and the property of detergent insolubility with plasma membrane assemblies rich in glycosphingolipids and cholesterol, often called lipid rafts, but preferably referred to here as caveolae-like membrane domains. Due to such widespread presence and usage in cellular function, caveolae... |
| Tipo: Journal article |
Palavras-chave: Caveolae; Caveolae-like domains; Lipid rafts; Caveolin-1; Tumor suppressor; Colon carcinoma cells; Microarray analysis. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200006 |
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| MEDINA,RODOLFO A.; OWEN,GARETH I.. |
| Mammalian cells depend on glucose as a major substrate for energy production. Glucose is transported into the cell via facilitative glucose transporters (GLUT) present in all cell types. Many GLUT isoforms have been described and their expression is cell-specific and subject to hormonal and environmental control. The kinetic properties and substrate specificities of the different isoforms are specifically suited to the energy requirements of the particular cell types. Due to the ubiquitousness of these transporters, their differential expression is involved in various disease states such as diabetes, ischemia and cancer. The majority of cancers and isolated cancer cell lines over-express the GLUT family members which are present in the respective tissue of... |
| Tipo: Journal article |
Palavras-chave: GLUT; Glucose transporters; Expression; Cancer; Estrogen; Progesterone; Cell lines. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000100004 |
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| NAIR,MADHAVAN P; KANDASWAMI,CHITHAN; MAHAJAN,SUPRIYA; NAIR,HARIKRISHNA N; CHAWDA,RAM; SHANAHAN,THOMAS; SCHWARTZ,STANLEY A. |
| Flavonoids and related polyphenols, in addition to their cardioprotective, anti-tumor, anti-inflammatory, anti-carcinogenic and anti-allergic activities, also possess promising anti-HIV effects. Recent studies documented that the ß-chemokine receptors, CCR2b, CCR3 and CCR5, and the alpha-chemokine receptors, CXCR1, CXCR2 and CXCR4 serve as entry coreceptors for HIV-1. Although flavonoids and polyphenolic compounds elicit anti-HIV effects such as inhibition of HIV-1 expression and virus replication, the molecular mechanisms underlying these effects remain to be clearly elucidated. We hypothesize that flavonoids exert their anti-HIV effects, possibly by interfering at the HIV co-receptor level. We investigated the effect of flavonoid constituents of a... |
| Tipo: Journal article |
Palavras-chave: PBMC; Peripheral blood mononuclear cells RT- PCR - reverse transcriptase polymerase chain reaction HIV-1; Human immunodeficiency virus-1 GSE; - Grape Seed Extract. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000300016 |
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| Registros recuperados: 992 | |
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