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Antonio Delgado

Publications and source records attributed to Antonio Delgado.

29 records · Page 2Linked to original sources
PubMed2004

The PROMISE study: PROphylaxis of MIgraine with SEglor (dihydroergotamine mesilate) in French primary care.

INTRODUCTION: Seglor capsules, a unique modified-release formulation of dihydroergotamine mesilate, have long been in clinical use in France for migraine prophylaxis. The aim of the PROMISE (PROphylaxis of MIgraine with SEglor) study was to establish the efficacy and tolerability of Seglor in the prevention of migraine in a general practice setting. METHODS: The PROMISE study was a double blind, placebo-controlled, parallel-group study carried out in primary care practice. It included 363 migraine patients treated with Seglor or placebo for 5 months after a 1-month placebo run-in phase. RESULTS: Migraine attack frequency (primary efficacy criterion) decreased markedly in the two treatment groups so that the difference in favour of Seglor did not reach statistical significance. However, most secondary outcome measures (duration of single attack, total duration of attacks over 1 month, consumption of mild opiate analgesics, subjective improvement) improved to a significantly greater degree in patients receiving Seglor than in those receiving placebo. In the 84.5% of patients who had impaired quality of life at entry, the percentage of reduction in attack frequency and most other efficacy measures showed significant improvement with Seglor. The safety profile for Seglor was comparable to that of placebo. CONCLUSION: These results support the effectiveness of Seglor in patients with migraine-related quality-of-life impairment. The findings of the PROMISE study also suggest that patients' quality of life should be assessed systematically before initiating a preventive treatment for migraine.

Adolescent↗
PubMed2003

Stereoselective aldol additions catalyzed by dihydroxyacetone phosphate-dependent aldolases in emulsion systems: preparation and structural characterization of linear and cyclic iminopolyols from aminoaldehydes.

The potential of dihydroxyacetone phosphate (DHAP)-dependent aldolases to catalyze stereoselective aldol additions is, in many instances, limited by the solubility of the acceptor aldehyde in aqueous/co-solvent mixtures. Herein, we demonstrate the efficiency of emulsion systems as reaction media for the class I fructose-1,6-bisphosphate aldolase (RAMA) and class II recombinant rhamnulose-1-phosphate aldolase from E. coli (RhuA)-catalyzed aldol addition between DHAP and N-benzyloxycarbonyl (N-Cbz) aminoaldehydes. The use of emulsions improved the RAMA-catalyzed aldol conversions by three to tenfold relative to those in conventional DMF/water mixtures. RhuA was more reactive than RAMA towards the N-Cbz aminoaldehydes regardless of the reaction medium. With (S)- or (R)-Cbz-alaninal, RAMA exhibited preference for the R enantiomer, while RhuA had no enantiomeric discrimination. The linear N-Cbz aminopolyols thus obtained were submitted to catalytic intramolecular reductive amination to afford the corresponding iminocyclitols. This reaction was diastereoselective in all cases examined; the face selectivity was controlled by the stereochemistry of the newly formed hydroxyl group originating from the aldehyde. Characterization of the resulting iminocyclitols allowed the assessment of the diastereoselectivity of the enzymatic aldol reactions with respect to the N-protected aminoaldehyde. RAMA formed single diastereoisomers from N-Cbz-glycinal and from both enantiomers of N-Cbz-alaninal, while 14 % of the epimeric product was observed from N-Cbz-3-aminopropanal. Diastereoselectivity from RhuA was lower than that observed from RAMA. Interestingly, a single diastereoisomer was formed from (S)-Cbz-alaninal, whereas only a 34 % diastereomeric excess was observed from its enantiomer (i.e., (R)-Cbz-alaninal).

Journal Article↗
PubMed2003

Three-dimensional numerical approach to investigate the substrate transport and conversion in an immobilized enzyme reactor.

This numerical study evaluates the momentum and mass transfer in an immobilized enzyme reactor. The simulation is based on the solution of the three-dimensional Navier-Stokes equation and a scalar transport equation with a sink term for the transport and the conversion of substrate to product. The reactor consists of a container filled with 20 spherical enzyme carriers. Each of these carriers is covered with an active enzyme layer where the conversion takes place. To account for the biochemical activity, the sink term in the scalar transport equation is represented by a standard Michaelis-Menten approach. The simulation gives detailed information of the local substrate and product concentrations with respect to external and internal transport limitations. A major focus is set on the influence of the substrate transport velocity on the catalytic process. For reactor performance analysis the overall and the local transport processes are described by a complete set of dimensionless variables. The interaction between substrate concentration, velocity, and efficiency of the process can be studied with the help of these variables. The effect of different substrate inflow concentrations on the process can be seen in relation to velocity variations. The flow field characterization of the system makes it possible to understand fluid mechanical properties and its importance to transport processes. The distribution of fluid motion through the void volume has different properties in different parts of the reactor. This phenomenon has strong effects on the arrangement of significantly different mass transport areas as well as on process effectiveness. With the given data it is also possible to detect zones of high, low, and latent enzymatic activity and to determine whether the conversion is limited due to mass transfer or reaction resistances.

Biological Transport↗
PubMed2003

Influence of stent treatment strategies in the long-term outcome of patients with long diffuse coronary lesions.

Diffuse coronary lesions (length > 20 mm) are still considered high risk for percutaneous intervention even in the current stent era. We compared the 2-year outcome of patients with long diffuse stenosis treated by three different stent strategies. In addition, we also analyzed the possible factors influencing a favorable late outcome. Our series is constituted by 232 patients with 247 long lesions treated between May 1994 and April 1999; 82 patients received one single long stent (group 1), 71 patients were treated by overlapped multiple stents (group 2), and 79 with multiple nonoverlapped stents (group 3). The mean age was 59 +/- 11 years. There were not significant differences between groups in terms of age, risk factors, clinical presentation, type of lesion, or adjunctive medical therapy. Patients from group 1 had shorter lesions (29 +/- 10 mm) than patients from groups 2 (41 +/- 15 mm) and 3 (36 +/- 14; P < 0.05). Major cardiac events (death, acute myocardial infarction, or repeat revascularization) at 24 +/- 12 months follow-up took place in 39 patients (17%). The probabilities of being free of major events at follow-up were 71%, 78%, and 80% for group 1, 2, and 3 respectively (P = NS). Only three variables were identified as significant predictors of these late events: smaller vessel size, smaller minimal lumen diameter after stenting, and the type of lesion being restenotic as compared with native stenosis. Patients with diffuse lesions treated by single long stents did not have a better late outcome than those who received multiple stents. The best late outcome was observed in those patients who had bigger vessel size, larger poststent lumen dimensions and native lesions, regardless of the stent deployment strategy used.

Aged↗
PubMed2002

Barbier-type diastereoselective allylation of alpha-amino aldehydes with an enantiopure 2-sulfinylallyl building block.

An optimized procedure for the diastereoselective allylation under aqueous Barbier conditions of a series of alpha-amino aldehydes with our new chiral building block (S(s))-3-chloro-2-(p-tolylsulfinyl)-1-propene [(S(s))-1a] to afford enantiomerically pure sulfinylamino alcohols in good yields and diastereoselectivites is reported. High levels of diastereoinduction can be achieved from alpha-amino aldehydes configurationally related to natural alpha-amino acids.

Journal Article↗
PubMed2002

State detection and control of overloads in the anaerobic wastewater treatment using fuzzy logic.

The two-stage anaerobic wastewater pre-treatment was modelled and controlled. The biological state of the reactors could be predicted using a fuzzy logic system and based upon this, proper control actions were taken automatically in order to avoid an overload. The system was designed to handle very strong fluctuations in the concentration of the substrate and the volumetric loading rate. Hydrogen concentration together with methane concentration, gas production rate. pH and the filling level of the acidification buffer tank were used as input variables for the fuzzy logic system. The manipulated variables were the flow rate from the acidification buffer tank into the methane reactor, the temperature and pH of both reactors, the circulation rate of the fixed bed reactor, back flow from the methane reactor into the acidification, and the control of the feed into the acidification buffer tank. The developed control system was successfully tested on a fully automated lab scale two-stage anaerobic digester. Different types of wastewater from food processing industries were successfully applied. Even a restart of feeding with very high COD concentrations (100 gl(-1) after several days of stand by was handled successfully. Effluent concentrations could be kept low without using TOC, COD or equivalent measurements.

Bacteria, Anaerobic↗
PubMed2002

Effectiveness of percutaneous device occlusion for atrial septal defect in adult patients with pulmonary hypertension.

BACKGROUND: Adult patients with atrial septal defect (ASD) and pulmonary hypertension have a more advanced degree of disease, frequently having functional class deterioration and atrial arrhythmias when they are aged >40 years. Surgery at this age prolongs life expectancy and limits functional deterioration. Although percutaneous ASD device occlusion is an accepted alternative to surgery, there is limited information on the immediate and long-term effects of device occlusion in middle-aged and elderly patients with ASD and pulmonary hypertension. METHODS: From a total of 101 patients with secundum ASD who were receiving treatment with percutaneous device occlusion, we selected for analysis 29 adult patients (mean age 56 +/- 14 years) with a baseline peak pulmonary pressure of >40 mm Hg (mean 65 +/- 23 mm Hg). Three of the patients had suprasystemic pulmonary pressure and a bidirectional shunt. Six patients were asymptomatic at treatment. The remaining 23 had different degrees of dyspnea; 14 of them had an advanced New York Heart Association functional class (III-IV). Twelve patients had chronic atrial fibrillation. At cardiac catheterization, the mean ratio of pulmonary to systemic flow was 1.8 +/- 0.5, and the pulmonary-to-systemic pressure ratio was 0.66 +/- 0.22. The mean diameter of the defect, as evaluated by the stretching balloon method, was 26 +/- 7 mm. All patients received an Amplatzer septal occluder (Golden Valley, Minn). Seven patients had combined therapeutic procedures for associated anomalies before the implant: mitral balloon valvuloplasty (n = 1), stent coronary revascularization (n = 1), stent in pulmonary vein stenosis (n = 1), and internal catheter defibrillation (n = 4). After treatment, patients were followed up by clinical and echocardiographic Doppler studies every 6 months. RESULTS: Immediately after the implantation, the peak systolic pulmonary pressure significantly decreased to 54 +/- 21 mm Hg (P <.001). A clear improvement in functional status was observed after the treatment in all symptomatic patients, especially in those with refractory heart failure. There were no major complications. Six patients who had atrial fibrillation at baseline study recovered to a stable sinus rhythm after treatment, and it was maintained at discharge. Complete ASD occlusion by echocardiographic Doppler at discharge was observed in 28 patients (97%). After a mean follow up of 21 +/- 14 months, clinical improvement persisted in all previously symptomatic patients, and the peak systolic pulmonary pressure, obtained by echocardiographic Doppler, further decreased to 31 +/- 11 mm Hg (P <.001) compared with baseline and immediately after hemodynamic measurements. CONCLUSIONS: Our findings suggest that percutaneous device occlusion of ASD in adult patients with pulmonary hypertension is safe and effective and provides significant and prolonged relief.

Adult↗
PubMed2002

In situ determination of the intracellular pH of Lactococcus lactis and Lactobacillus plantarum during pressure treatment.

Hydrostatic pressure may affect the intracellular pH of microorganisms by (i) enhancing the dissociation of weak organic acids and (ii) increasing the permeability of the cytoplasmic membrane and inactivation of enzymes required for pH homeostasis. The internal pHs of Lactococcus lactis and Lactobacillus plantarum during and after pressure treatment at 200 and 300 MPa and at pH values ranging from 4.0 to 6.5 were determined. Pressure treatment at 200 MPa for up to 20 min did not reduce the viability of either strain at pH 6.5. Pressure treatment at pH 6.5 and 300 MPa reduced viable cell counts of Lactococcus lactis and Lactobacillus plantarum by 5 log after 20 and 120 min, respectively. Pressure inactivation was faster at pH 5 or 4. At ambient pressure, both strains maintained a transmembrane pH gradient of 1 pH unit at neutral pH and about 2 pH units at pH 4.0. During pressure treatment at 200 and 300 MPa, the internal pH of L. lactis was decreased to the value of the extracellular pH during compression. The same result was observed during treatment of Lactobacillus plantarum at 300 MPa. Lactobacillus plantarum was unable to restore the internal pH after a compression-decompression cycle at 300 MPa and pH 6.5. Lactococcus lactis lost the ability to restore its internal pH after 20 and 4 min of pressure treatment at 200 and 300 MPa, respectively. As a consequence, pressure-mediated stress reactions and cell death may be considered secondary effects promoted by pH and other environmental conditions.

Animals↗
PubMedDate not supplied

Combinatorial approach to N-substituted aminocyclitol libraries by solution-phase parallel synthesis and preliminary evaluation as glucocerebrosidase inhibitors.

Libraries of N-substituted aminocyclitol derivatives of the scyllo and racemic chiro series by means of parallel solution-phase methodology with the help of robotic technology are described. Chemical diversity has been introduced by reaction of selected scaffolds with a set of aldehydes, acyl chlorides, sulfonyl chlorides, chloroformates, and amines to afford the corresponding amines, amides, sulfonamides, carbamates and ureas, respectively. The optimized methodology has proven excellent, in terms of overall purities of the resulting libraries, for the production of amides. Sulfonamides and carbamates have been obtained in slightly lower purities, while amines afforded modest results. Selected library members have been evaluated as inhibitors of recombinant glucocerebrosidase with K(i) values ranging in the low micromolar scale for the most active members.

Alcohols↗
PubMedDate not supplied

Phosphogypsum amendment effect on radionuclide content in drainage water and marsh soils from southwestern Spain.

Phosphogypsum (PG) is a residue of the phosphate fertilizer industry that has relatively high concentrations of 226Ra and other radionuclides. Thus, it is interesting to study the effect of PG applied as a Ca amendment on the levels and behavior of radionuclides in agricultural soils. A study involving treatments with 13 and 26 Mg ha(-1) of PG and 30 Mg ha(-1) of manure was performed, measuring 226Ra and U isotopes in drainage water, soil, and plant samples. The PG used in the treatment had 510 +/- 40 Bq kg(-1) of 226Ra. The 226Ra concentrations in drainage waters from PG-amended plots were similar (between 2.6 and 7.2 mBq L(-1)) to that reported for noncontaminated waters. Although no significant effect due to PG was observed, the U concentrations in drainage waters (200 mBq L(-1) for 238U) were one order of magnitude higher than those described in noncontaminated waters. This high content in U can be ascribed to desorption processes mainly related to the natural adsorbed pool in soil (25 Bq kg(-1) of 238U). This is supported by the 234U to 238U isotopic ratio of 1.16 in drainage waters versus secular equilibrium in PG and P fertilizers. The progressive enrichment in 226Ra concentration in soils due to PG treatment cannot be concluded from our present data. This PG treatment does not determine any significant difference in 226Ra concentration in drainage waters or in plant material [cotton (Gossipium hirsutum L.) leaves]. No significant levels of radionuclides except 40K were found in the vegetal tissues.

Agriculture↗