PubMed Health⌕ Search

Biomedical subjects

J de Andrés

Publications and source records attributed to J de Andrés.

15 recordsLinked to original sources
PubMed2005

Inelastic electronic excitation and electron transfer processes in collisions between Mg(31S0) atoms and K+(1S0) ions studied by crossed beams in the 0.10-3.80-keV energy range.

Inelastic and charge-transfer excitation processes in collisions between ground-state neutral Mg atoms and K+ ions have been studied by means of a crossed molecular-beam technique. Decay fluorescent emissions from Mg(3 1P1),Mg(4 3S1), and Mg(3s(1)3d(1), 3(3)D3,2,1) as well as the phosphorescent emission due to Mg(3 3P1) have been observed from excited Mg atoms and the charge-transfer emission decays from K(4 2P 3/2,1/2), K(5 2P 3/2, 1/2), K(6 2S 1/2), and K(4 2D 5/2, 3/2) for excited K atoms. The corresponding absolute cross-sections values versus collision energy functions were determined in the 0.10-3.80 keV laboratory energy range. In order to interpret the experimental results, accurate ab initio full configuration-interaction calculations using pseudopotentials have been performed for the (Mg-K)+ system, giving a manifold of adiabatic singlet and triplet potential-energy curves correlating with the different collision channels, which allow a qualitative interpretation of the emission excitation functions measured for the different processes studied. A comparative study with other Mg-alkali ion systems previously studied is also included.

Journal Article↗
PubMed2004

Electronic excitation and charge transfer processes in collisions between Mg(3(1)S0) atoms and Rb+(1S0) ions in the 0.07-4.00 keV energy range.

Inelastic collision processes between neutral Mg atoms and Rb(+) ions, both in their ground states, have been studied by means of a crossed molecular beam technique measuring the decay fluorescence of the excited species formed. Emissions corresponding to Mg(3 (1)P(1)), Mg(3 (3)D(3,2,1)), and Mg(4 (3)S(1)), formed by direct target excitation, Rb(5 (2)P(3/2,1/2)), Rb(6 (2)P(3/2,1/2)) produced by electron capture and also the phosphorescent emission due to decay of Mg(3 (3)P(1)), have been detected and the corresponding absolute cross-section values measured both as total values and resolved into their J states. No polarization measurements could be made. Ab initio calculations using pseudopotentials have been performed and from these a manifold of adiabatic energy curves correlating with the different entry and exit channels have been obtained, allowing to propose a qualitative interpretation of the results, such as the shape of the cross section vs energy for different transitions and the oscillating nature of the branching ratios due to interference effects.

Journal Article↗
PubMed1997

[Influence of paid work on the perceived health state in women].

BACKGROUND: Several studies show that paid work has a positive effect on women's health, although few studies have shown this relationship in Southern-European countries. The aim of this paper was to analyze the self-perceived health status of women of Barcelona, Spain according to their type of work (homemaker or worker). PATIENTS AND METHODS: Cross sectional study using the 1992 Barcelona Health Interview Survey data. SUBJECTS: 1194 women aged 25 to 64 years old. Bivariate analysis of women's perceived health status by all other variables. A logistic regression model was performed with the dependent variable being women's self-perceived health status and the independent variables: type of work (homemaker or worker), age, number of chronic diseases, medical care visits, children under 12 years and elderly over 65 years living at home and social class based on occupation. RESULTS: 15.8% of workers and 31.4% of homemakers reported poor self-perceived health status (p < 0.05). This same distribution was maintained when adjusting for all independent variables. Social class had an important relationship with health, with women from lower social classes reporting poorer self-perceived health status than homemakers from upper social classes. CONCLUSIONS: The 1992 Barcelona Health Interview Survey analysis confirms that in Barcelona as well, paid work has a positive relationship on women's self-perceived health status.

Adult↗
PubMed1995

A novel regulatory pathway of brown fat thermogenesis. Retinoic acid is a transcriptional activator of the mitochondrial uncoupling protein gene.

The mitochondrial uncoupling protein (UCP) is responsible for the thermogenic function of brown fat, and it is a molecular marker of the brown adipocyte cell type. Retinoic acid (RA) increased UCP mRNA levels severalfold in brown adipocytes differentiated in culture. This induction was independent of adrenergic pathways or protein synthesis. RA stimulated ucp gene expression regardless of the stage of brown adipocyte differentiation. In transient transfection experiments RA induced the expression of chloramphenicol acetyltransferase vectors driven by 4.5 kilobases of the 5'-noncoding region of the rat ucp gene, and co-transfection of expression vectors for RA receptors enhanced the action of RA. Retinoic acid receptor alpha was more effective than retinoid X receptor in promoting RA action, whereas a mixture of the two was the most effective. The RA-responsive region in the ucp gene was located at -2469/-2318 and contains three motifs (between -2357 and -2330) of the consensus half-sites characteristic of retinoic acid response elements. This 27-base pair sequence specifically binds purified retinoic acid receptor alpha as well as related proteins from brown fat nuclei. In conclusion, a novel potential regulatory pathway of brown fat development and thermogenic function has been recognized by identifying RA as a transcriptional activator of the ucp gene.

Adipocytes↗
PubMed1995

[Analysis of knowledge about the anesthesiology specialty among a population of medical students].

OBJECTIVES: To analyze the knowledge of anesthesiology possessed by a group of medical students representative of medically trained individuals who have not yet worked in a hospital. MATERIAL AND METHOD: Students in their fifth year of medical studies at the University of Valencia were invited to voluntarily and anonymously answer a questionnaire with dichotomous and multiple choice responses covering general and specific aspects of anesthesiology. The survey also collected personal and epidemiological data. One hundred eighty-five questionnaires were returned. RESULTS: The results obtained were analyzed for correlations with epidemiological and personal data (sex, information received, prior anesthesia); no significant correlations were found between these data and correct response. It was believed by 78.4% that the anesthesiologist's function during surgery does not go beyond warning the surgeon of changes in vital signs. Nevertheless, 76.2% asserted that the anesthesiologist's function is to protect the patient during the perioperative period. CONCLUSION: In comparison with the general population, medical students' training has left them with inadequate understanding of anesthesiology.

Adult↗
PubMed1994

Comparison of continuous spinal anaesthesia using a 32-gauge catheter with anaesthesia using a single-dose 24-gauge atraumatic needle in young patients.

One hundred and twenty-eight ASA I-III patients less than 40 yr of age, undergoing orthopaedic or trauma lower limb surgery, were allocated randomly to receive either continuous spinal anaesthesia (CSA) using a 32-gauge polyimide microcatheter with a permanent stylet (Rusch/TFX Medical, Duluth, GA, USA) or single-dose spinal anaesthesia (SDSA) with a 24-gauge x 103-mm Sprotte spinal needle (Pajunk, Germany). Plain bupivacaine (0.5%) was used as the local anaesthetic. The initial doses were 1 ml (5 mg) of CSA and 3 ml (15 mg) of SDSA, while the re-injection doses were 1 ml (5 mg) in the CSA group. SDSA was quicker to perform: mean 4.4 (SD 1.6) min compared with 6.2 (2.6) min for CSA (P < 0.01). Times to onset and surgical anaesthesia were also significantly greater in the CSA group (P < 0.01). The quality of the block was better in the SDSA group (P < 0.05), but was associated with greater haemodynamic instability (P < 0.05). The segmental level of analgesia was significantly lower in the CSA group (median T10 (range T12-T8)) than in the SDSA group (T9 (T11-T5)) (P < 0.05). There were no significant differences in the incidence of postoperative complications, with two mild spinal headaches in both groups. We conclude that CSA using a microcatheter in young patients is difficult to perform and affords no advantages over SDSA with a small gauge atraumatic needle.

Adult↗
PubMedDate not supplied

[Drugs that alter hemostasis and regional anesthetic techniques: safety guidelines. Consensus conference].

Patients about to undergo surgery are often taking drugs that alter hemostasis and affect anesthesia, particularly when neuroaxial techniques are used for subarachnoid or epidural anesthesia. The aim of this paper is to provide safety guidelines for regional anesthesia in patients receiving hemostasis-altering drugs, in order to reduce the risk of bleeding. We offer a detailed discussion of patients treated with inhibitors of platelet aggregation (emphasizing that such treatment alone is not a contraindication for neuroaxial blockade although certainly guidelines must be followed), unfractionated heparin (anesthesia should be started at least 4 hours after administration of this drug or 30 minutes before, provided pulmonary arterial pressure is normal), low molecular weight heparin (which should be administered 12 hours before or 12 hours after the anesthetic technique), and oral anticoagulants (provision of regional anesthesia depends mainly on International Normalized Ratio monitoring). We also stress that removal of catheters should follow criteria similar to those listed above, that the risk of complications due to bleeding increases considerably in association with these drugs, and that adequate neurological monitoring is essential during postoperative recovery. Overall, the final decision to use regional anesthesia in patients receiving drugs that alter hemostasis must be made on an individual basis after assessment of benefit and risk.

Administration, Oral↗
PubMedDate not supplied

[Localization of lumbar epidural space by loss of resistance and using the Episensor: a comparative study].

Since the existence of negative pressure in the epidural space was reported, its technique of localization has undergone changes directed to improve objectivity, reliability and safety. The aim of the present study was to evaluate a new electronic divide to localize the epidural space, i.e. the Episensor (Palex, Spain). To this end, 71 patients, both males and females, undergoing elective urological surgery and in whom catheterization of the lumbar epidural space had been planned, were prospectively evaluated and randomly assigned to two homogeneous groups. In group I (n = 35) the epidural space was localized by the classical technique of loss of resistance, while in group II the Episensor was used. In both groups several technical parameters, the qualification of the operator and the complications of the procedure were evaluated. There were no significant differences between both groups regarding the quality of epidural blockade or the subjective technical difficulty of the operator. The incidence of complications of the technique of puncture was significantly higher in group II (p less than 0.05); the most common were dura mater puncture in 13 group II patients and in one group I patient (p less than 0.001). There was no correlation between the qualification of the operator and the development of complications. It was concluded that the use of Episensor to localize lumbar epidural space did not improve the effectiveness of blockade but increased the iatrogenic effects of the puncture. Our lack of experience with this new technique and the low negative pressure of lumbar epidural space might have been the causes of the poor results, that we consider as initial in the evaluation of this new method.

Adult↗
PubMedDate not supplied

[Comparative study of propofol and midazolam for sedation in regional anesthesia].

OBJECTIVES: To compare the efficacy of propofol and midazolam as sedatives in non-premedicated patients receiving regional anesthesia. MATERIAL AND METHODS: Parameters measured were quality of sedation, intraoperative changes in hemodynamics, respiration and plasma biochemistry as compared with baseline, preinduction and post-anesthetic recovery levels. Forty patients were distributed randomly into two groups. Group P (n = 20) received an infusion of 1% propofol (10 mg/ml) at an initial rate of 6 mg/kg/h for 10 minutes, later decreased to 3 mg/kg/h. Group M (n = 20) received an infusion of 0.3% midazolam with an initial bolus of 0.06 mg/kg along with simultaneous infusion at a rate of 0.05 mg/kg/h. RESULTS: Adequate sedation that was easily controlled during surgery was attained in both groups. The mean doses used were 336.7 +/- 33.7 mg in group P and 10.1 +/- 1.1 mg in group M. No significant changes in hemodynamic and respiratory parameters were observed. Differences between baseline and preinduction levels were found in some analyses, but significant changes during surgery were recorded only for HCO3-. There were no differences in recovery time from the moment infusion ceased until spontaneous eye opening and recall of date of birth. The degree of amnesia was greater in the midazolam group. The lesser amnesia with propofol meant that psychological measures were higher (p < 0.01). No differences in side effects were found. CONCLUSION: Continuous perfusion of propofol and midazolam for sedation in regional anesthesia are equivalent with respect to efficacy and safety.

Adult↗