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Biomedical subjects

A Ferrando

Publications and source records attributed to A Ferrando.

At least 19 recordsLinked to original sources
PubMed2001

Effect of chronic ethanol ingestion and exercise training on skeletal muscle in rat.

The aim of this study was to investigate the interactive effects of exercise training and chronic ethanol consumption on metabolism, capillarity, and myofibrillar composition in rat limb muscles. Male Wistar rats were treated in separate groups as follows: non exercised-control; ethanol (15%) in animals' drinking water for 12 weeks; exercise training in treadmill and ethanol administration plus exercise for 12 weeks. Ethanol administration decreased capillarity and increased piruvate kinase and lactate dehydrogenase activities in white gastrocnemius; in plantaris muscle, ethanol increased citrate synthase activity and decreased cross-sectional area of type I, IIa, and IIb fibres. Exercise increased capillarity in all four limb muscles and decreased type I fibre area in plantaris. The decreased capillarity effect induced by ethanol in some muscles, was ameliorated when alcohol was combined with exercise. While alcoholic myopathy affects predominantly type IIb fibres, ethanol administration and aerobic exercise in some cases can affect type I and type IIa fibre areas. The exercise can decrease some harmful effects produced by ethanol in the muscle, including the decrease in the fibre area and capillary density.

Analysis of Variance↗
PubMed2001

Detection of in vivo protein interactions between Snf1-related kinase subunits with intron-tagged epitope-labelling in plants cells.

Plant orthologs of the yeast sucrose non-fermenting (Snf1) kinase and mammalian AMP-activated protein kinase (AMPK) represent an emerging class of important regulators of metabolic and stress signalling. The catalytic alpha-subunits of plant Snf1-related kinases (SnRKs) interact in the yeast two-hybrid system with different proteins that share conserved domains with the beta- and gamma-subunits of Snf1 and AMPKs. However, due to the lack of a robust technique allowing the detection of protein interactions in plant cells, it is unknown whether these proteins indeed occur in SnRK complexes in vivo. Here we describe a double-labelling technique, using intron-tagged hemagglutinin (HA) and c-Myc epitope sequences, which provides a simple tool for co-immunopurification of interacting proteins expressed in Agrobacterium-transformed Arabidopsis cells. This generally applicable plant protein interaction assay was used to demonstrate that AKINbeta2, a plant ortholog of conserved Snf1/AMPK beta-subunits, forms different complexes with the catalytic alpha-subunits of Arabidopsis SnRK protein kinases AKIN10 and AKIN11 in vivo.

Arabidopsis↗
PubMed2001

SKP1-SnRK protein kinase interactions mediate proteasomal binding of a plant SCF ubiquitin ligase.

Arabidopsis Snf1-related protein kinases (SnRKs) are implicated in pleiotropic regulation of metabolic, hormonal and stress responses through their interaction with the kinase inhibitor PRL1 WD-protein. Here we show that SKP1/ASK1, a conserved SCF (Skp1-cullin-F-box) ubiquitin ligase subunit, which suppresses the skp1-4 mitotic defect in yeast, interacts with the PRL1-binding C-terminal domains of SnRKs. The same SnRK domains recruit an SKP1/ASK1-binding proteasomal protein, alpha4/PAD1, which enhances the formation of a trimeric SnRK complex with SKP1/ASK1 in vitro. By contrast, PRL1 reduces the interaction of SKP1/ASK1 with SnRKs. SKP1/ASK1 is co-immunoprecipitated with a cullin SCF subunit (AtCUL1) and an SnRK kinase, but not with PRL1 from Arabidopsis cell extracts. SKP1/ASK1, cullin and proteasomal alpha-subunits show nuclear co-localization in differentiated Arabidopsis cells, and are observed in association with mitotic spindles and phragmoplasts during cell division. Detection of SnRK in purified 26S proteasomes and co-purification of epitope- tagged SKP1/ASK1 with SnRK, cullin and proteasomal alpha-subunits indicate that the observed protein interactions between SnRK, SKP1/ASK1 and alpha4/PAD1 are involved in proteasomal binding of an SCF ubiquitin ligase in Arabidopsis.

Amino Acid Sequence↗
PubMed2000

Intron-tagged epitope: a tool for facile detection and purification of proteins expressed in Agrobacterium-transformed plant cells.

Epitope tagging provides a useful tool for immunological detection and cellular localization of proteins in vivo. Using T-DNA-mediated transformation, the detection of epitope-tagged proteins in planta is currently feasible only in transgenic plants, because an artificial expression of cDNA and gene constructs driven by plant promoters in bacteria obscures an early detection of epitope-tagged proteins in Agrobacterium-infected plant cells. We have developed a method for labelling plant coding sequences with intron-tagged epitope-coding domains that are not processed in Agrobacterium. Here we show that the expression of HA-epitope-tagged constructs encoding beta-glucuronidase and S-phase kinase-associated (AtSKP1/ASK1) proteins can be specifically and exclusively detected in cultured Arabidopsis cells as early as five days after Agrobacterium infection. This epitope-tagging approach offers an unlimited source of transformed material for purification and localization of proteins expressed individually or simultaneously in Agrobacterium-transformed plant cells.

Arabidopsis↗
PubMed2000

Influence of glucose kinetics on plasma lactate concentration and energy expenditure in severely burned patients.

BACKGROUND: In critically ill patients, elevation in the plasma lactate concentration has traditionally been interpreted as indicating a deficiency in oxygen availability and is often an impetus to increase oxygen delivery clinically. However, another possible basis for increased lactate concentrations may be simply a mass effect from increased pyruvate availability (i.e., accelerated glycolysis). METHODS: In six hypermetabolic burned patients, the rates of glucose production and oxidation were quantified using a tracer infusion of 6,6 d2 glucose combined with indirect calorimetry. Measurements were obtained after a 9-hour fast and after a 3-hour infusion of unlabeled glucose at 30 micromol/kg/min. No patient was overtly septic, hypoxic, or hypovolemic. RESULTS: The infusion of glucose significantly increased the arterial glucose concentration and rate of glucose oxidation, with a corresponding increase in the arterial plasma concentration of lactate and pyruvate. Resting energy expenditure and oxygen consumption were not affected by the infusion of glucose. CONCLUSIONS: These findings show that elevations in plasma lactate in severely injured patients may, in part, be related to increases in glucose flux and not entirely a reflection of any deficit in oxygen availability. Such findings highlight a potential pitfall for interpreting plasma lactate concentrations as an index of tissue oxygen availability in hypermetabolic patients.

Adult↗
PubMed2000

Ansatz-independent solution of a soliton in a strong dispersion-management system

We introduce a theoretical approach to the study of propagation in systems with periodic strong-management dispersion. Our approach does not assume any ansatz about the form of the solution nor does it make use of any average procedure. We find an explicit solution for the pulse evolution in the fast dynamics regime (distances smaller than the dispersion period). We also establish the equation of motion governing the slow dynamics of an arbitrary pulse and prove that the pulse evolution is nonlinear and Hamiltonian. We solve this equation and find that a nonlinear solitonlike solution occurs self-consistently in the form of an asymptotic stationary eigenfunction of the Hamiltonian.

Journal Article↗
PubMed2000

Vector description of higher-order modes in photonic crystal fibers

We extensively study the propagation features of higher-order modes in a photonic crystal fiber (PCF). Our analysis is based on a full-vector modal technique specially adapted to accurately describe light propagation in PCF's. Unlike conventional fibers, PCF's exhibit a somewhat unusual mechanism for the generation of higher-order modes. Accordingly, PCF's are characterized by the constancy of the number of modes below a wavelength threshold. An explicit verification of this property is given through a complete analysis of the dispersion relations of higher-order modes in terms of the structural parameters of this kind of fiber. The transverse irradiance distributions for some of these higher-order modes are also presented, showing an excellent agreement with recent experimental measurements. In the same way, the full-vector nature of our approach allows us to analyze the rich polarization structure of the PCF mode spectrum.

Journal Article↗
PubMed2000

Testosterone and muscle protein metabolism.

This presentation discusses recent investigations into testosterone's effects on muscle protein metabolism. Protein synthesis is the principal end point, but protein breakdown and the availability of an amino acid pool are important to the process of net muscle protein synthesis. The effects of other hormones--including growth hormone, oxoandrolone (a synthetically derived testosterone), and androstenedione--on muscle protein synthesis also are discussed. Effects in both normal and elderly men are considered.

Aged↗
PubMed1999

Effects of administration of the standardized Panax ginseng extract G115 on hepatic antioxidant function after exhaustive exercise.

The effect of prolonged treatment with the standardized Panax ginseng extract G115 on the antioxidant capacity of the liver was investigated. For this purpose, rats that had received G115 orally at different doses for 3 months and untreated control rats were subjected to exhaustive exercise on a treadmill. A bell-shaped dose response on running time was obtained. The results showed that the administration of G115 significantly increases the hepatic glutathione peroxidase activity (GPX) and the reduced glutathione (GSH) levels in the liver, with a dose-dependent reduction of the thiobarbituric acid reactant substances (TBARS). After the exercise, there is reduced hepatic lipid peroxidation, as evidenced by the TBARS levels in both the controls and the treated animals. The GPX (glutathione peroxidase) and SOD (superoxide dismutase) activity are also significantly increased in the groups receiving G115, compared with the controls. The hepatic transaminase levels, ALT (Alanine-amino-transferase) and AST (Aspartate-amino-transferase), in the recuperation phase 48 h after the exercise, indicate a clear hepatoprotective effect related to the administration of the standardized Panax ginseng extract G115. At hepatic level, G115 increases the antioxidant capacity, with a marked reduction of the effects of the oxidative stress induced by the exhaustive exercise.

Animals↗
PubMed1999

Effects of a standardized Panax ginseng extract on the skeletal muscle of the rat: a comparative study in animals at rest and under exercise.

The effect of standardized Panax ginseng extract G115 on enzymatic activities, myotypological composition, capillaries and mitochondrial content was studied in the skeletal muscle of male rats Wistar. Simultaneously to the G115 administration the rats performed exercise. The animals were divided into 4 groups. The dose of the ginseng extract G115 was 50 mg/kg. The length of the experimental period was 12 weeks. After 24 hours of inactivity the muscles of the hindlimb were extracted. With regard to the enzymatic activities of the citrate synthase (CS) and lactate dehydrogenase (LDH), CS increases with exercise, while the LDH undergoes no major variations, either due to the exercise or the treatment. Treatment with G115 increases the capillary density and the mitochondrial content of the red gastrocnemius muscle. The results suggest that prolonged treatment with G115 increases the capillary density and the oxidative capacity of the muscles with greater aerobic potential in a manner similar to the performance of physical exercise. When exercise and treatment are combined, the effects that are obtained separately are not potentiated.

Animals↗
PubMed1999

Effects of ginseng extract on various haematological parameters during aerobic exercise in the rat.

The effects of the Ginseng extract on various biochemical and haematological parameters in male Wistar rats subjected to a treadmill exercise protocol were studied for 12 weeks. The results showed increases in the haematological parameters, these increases being greatest for the animals treated with the extract during the third month of the study. The exercise also led to increases in these parameters, while the combination of both exercise and extract produced smaller increases. This study shows a clear physiological response due to the ginseng extract administration that reproduces many of the effects obtained after long-term exercise. The combination of exercise and treatments seems to support the theory that there is no clear synergic effect when the advantages associated with the ingestion of ginseng are compared with the performance of exercise.

Animals↗
PubMed1997

Mechanisms of salt tolerance conferred by overexpression of the HAL1 gene in Saccharomyces cerevisiae.

Overexpression of the HAL1 gene improves the tolerance of Saccharomyces cerevisiae to NaCl by increasing intracellular K+ and decreasing intracellular Na+. The effect of HAL1 on intracellular Na+ was mediated by the PMR2/ENA1 gene, corresponding to a major Na+ efflux system. The expression level of ENA1 was dependent on the gene dosage of HAL1 and overexpression of HAL1 suppressed the salt sensitivity of null mutants in calcineurin and Hal3p, other known regulators of ENA1 expression. The effect of HAL1 on intracellular K+ was independent of the TRK1 and TOK1 genes, corresponding to a major K+ uptake system and to a K+ efflux system activated by depolarization, respectively. Overexpression of HAL1 reduces K+ loss from the cells upon salt stress, a phenomenon mediated by an unidentified K+ efflux system. Overexpression of HAL1 did not increase NaCl tolerance in galactose medium. NaCl poses two types of stress, osmotic and ionic, counteracted by glycerol synthesis and sodium extrusion, respectively. As compared to glucose, with galactose as carbon source glycerol synthesis is reduced and the expression of ENA1 is increased. As a consequence, osmotic adjustment through glycerolsynthesis, a process not affected by HAL1, is the limiting factor for growth on galactose under NaCl stressed.

Adaptation, Physiological↗
PubMed1996

[Glomus jugulare tumor: perioperative management].

Surgical treatment of glomus jugulare tumors yields high rates of perioperative morbidity and mortality for several reasons, among them neuroendocrine secretory activity, a high degree of vascularization, intracranial extension, duration of surgery and cranial nerve lesion. Secretory activity (e.g. catecholamines and serotonin) should be investigated before surgery and treated appropriately. Carotid arteriography (and ball occlusion) are useful to assess vascularization of the tumor and determine the need to clamp the carotid artery during the procedure. Potential complications such as hemodynamic alterations (bleeding or endocrine response), pulmonary embolism (air or thrombotic), hypothermia, facial nerve lesion, should be monitored for during surgery. After surgery cranial nerve involvement, which can lead to dysphagia and bronchoaspiration, must be looked for; the risk of cerebro-spinal fluid fistula is also high. We report the case of a woman who underwent surgery for a non secreting glomus jugulare tumor with extradural intracranial invasion. The main complications during surgery were bleeding with hemodynamic repercussions, pulmonary embolism, lesions in the VII, VIII and X cranial nerves, and opening of the dura mater (which required insertion of an intradural drain to prevent formation of a fistula). After surgery oral intake was delayed until intestinal function was established and glottic sphincter competence was verified by fiberoptic laryngoscopy. The only complication presenting at this time was cephalea, which disappeared upon removal of the drain on day 4. The patient was released on day 10.

Catheterization↗