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I Luque

Publications and source records attributed to I Luque.

49 records · Page 3Linked to original sources
PubMed1995

Serological survey for avian paramyxoviruses from wildfowl in aquatic habitats in Andalusia.

A serological survey for a range of avian paramyxoviruses (PMV) was carried out among wildfowl from southern Spain, 1990 to 1992, using the hemagglutination inhibition technique. We collected 579 sera from 24 avian families (18 aquatic and six non-aquatic). Antibodies were detected to all paramyxoviruses in waterfowl, with a notable prevalence of antibodies to PMV-8 (43%) and to a lesser extent PMV-6 (21%). By contrast, in non-aquatic species high antibody prevalences were detected only to PMV-2 (60%), particularly in sparrows (68%), while antibody prevalences to other PMV's were moderate or low.

Animals↗
PubMed1994

Molecular mechanism for the operation of nitrogen control in cyanobacteria.

In cyanobacteria, ammonium exerts a negative regulation of the expression of proteins involved in the assimilation of nitrogen sources alternative to ammonium. In Synechococcus, mRNA levels of genes encoding proteins for nitrate and ammonium assimilation were observed to be negatively regulated by ammonium, and ammonium-regulated transcription start points were identified for those genes. The NtcA protein is a positive regulator of genes subjected to nitrogen control by ammonium. Mutants lacking NtcA exhibited only basal mRNA levels of the regulated genes, even in the absence of ammonium, indicating that NtcA exerts its regulatory action by positively influencing mRNA levels of the nitrogen-regulated genes. NtcA was observed to bind directly to the promoters of nitrogen-regulated genes, and the palindromic DNA sequence GTAN8TAC was identified as a sequence signature for NtcA-target sites. The structure of the nitrogen-, NtcA-regulated promoters of Synechococcus was determined to be constituted by a -10, Pribnow-like box in the form TAN3T, and an NtcA-binding site that substituted for the canonical -35 box.

Amino Acid Sequence↗
PubMed1994

Prevalence of antibodies to different Leptospira interrogans serovars in pigs on large farms.

A seroepidemiological survey was carried out in the province of Badajoz (south-western Spain) in order to determine the presence and spread of Leptospira interrogans. The 521 sera tested were drawn from breeding sows on 28 large farms (15 with fewer than 60 and 13 with over 60 breeders). Immunological testing was performed using the Martin-Pettit micro-agglutination technique. Pigs with titres equal to or greater than 1:100 were considered positive. Haemolysed and/or contaminated test sera were reprocessed following filter-paper treatment. A total of 10.56% of pigs tested proved positive, 39.28% of farms being affected. The following L. interrogans serovars were detected: pomona (6.53%), castellonis (1.15%), sejroe (1.15%), grippotyphosa (0.96%), australis (0.38%), hebdomadis (0.19%) and icterohaemorrhagiae (0.19%).

Animals↗
PubMed1994

Identification of Streptococcus suis isolated from swine: proposal for biochemical parameters.

A study was made of the biochemical profiles of 59 strains serotyped as Streptococcus suis, isolated from diseased and clinically healthy pigs. The following parameters are proposed for the identification of the species: Voges-Proskauer negativity, hydrolysis of esculin positivity, trehalose positivity, negativity for growth in 6.5% NaCl, and absence of beta-hemolysis on sheep blood agar. S. suis serotype 2 is negative for hippurate, pyrrolidonylarylamidase, and mannose.

Animals↗
PubMed1993

Nitrite reductase gene from Synechococcus sp. PCC 7942: homology between cyanobacterial and higher-plant nitrite reductases.

The gene encoding nitrite reductase (nir) from the cyanobacterium Synechococcus sp. PCC 7942 has been identified and sequenced. This gene comprises 1536 nucleotides and would encode a polypeptide of 56,506 Da that shows similarity to nitrite reductase from higher plants and to the sulfite reductase hemoprotein from enteric bacteria. Identities found at positions corresponding to those amino acids which in the above-mentioned proteins hold the Fe4S4-siroheme active center suggest that nitrite reductase from Synechococcus bears an active site much alike that present in those reductases. The fact that the Synechococcus and higher-plant nitrite reductases are homologous proteins gives support to the endosymbiont theory for the origin of chloroplasts.

Amino Acid Sequence↗
PubMed1992

Clustering of genes involved in nitrate assimilation in the cyanobacterium Synechococcus.

A region of the genome of the cyanobacterium Synechococcus R2, that bears a cluster of genes involved in nitrate assimilation, has been cloned and the relative positions of some of the genes in the region have been determined. Mutations generated by insertion of an antibiotic-resistance gene cassette into the gene encoding nitrite reductase are associated with reduced expression of nitrate reductase; cotranscription of nitrate assimilation genes in the cluster is inferred from this finding.

Blotting, Southern↗
PubMed1990

A comparison of repair and replacement for mitral stenosis with partially calcified valve.

From January 1978 to December 1987 we operated on 135 patients with calcified mitral stenosis. In 60 patients a conservative operation was performed (group I). Nine patients required mitral annuloplasty associated with the commissurotomy. The other 75 patients underwent mitral valve replacement (group II). In 37 patients a mechanical prosthesis was used and in 38 a biologic one. The patients given mitral valve replacement had a more heavily calcified valve than those undergoing a conservative procedure. Twenty-one patients (12 from group I and 13 from group II) required associated tricuspid annuloplasty. The mean follow-up time was 69.1 months (1 months to 10 years). There were no significant differences between the two groups in terms of operative death (0% and 4%, respectively), postoperative functional class, actuarial survival rate at 10 years (84% and 96%, respectively), and probability of freedom from thromboemboli at 10 years (98% and 96%, respectively). However, the probability of freedom from reoperation at 10 years significantly favored the conservative surgery group (84% and 69%, respectively, p less than 0.01). Finally, the probability of freedom from complications at 10 years was also significantly higher in the conservative surgery group (82% and 64%, respectively, p less than 0.005). Because of these results we believe that conservative surgery is, at present, a better alternative than mitral valve replacement for patients with partially calcified mitral stenosis.

Actuarial Analysis↗
PubMed1988

Conservative operation for mitral stenosis. Independent determinants of late results.

A retrospective study was designed to define the independent determinants of late results in 282 consecutive patients operated on for mitral stenosis between 1978 and 1985. A total of 25 variables were investigated by multivariate discriminant analysis for their possible influence on symptomatic outcome, subsequent reoperation, postoperative thromboembolism, and death. All the patients underwent a conservative mitral valve operation. In addition, 25 patients required concomitant tricuspid annuloplasty. The surgical mortality rate was 1.4% and the late mortality, reoperation, and thromboembolism rates were, respectively, 0.14%, 0.80%, and 0.95%/pt-yr. Actuarial probability of complication-free survival at 8 years was 83% +/- 3.7%. Left atrial size on the M-mode echocardiograms, tricuspid annuloplasty, mitral annuloplasty, presence of left atrial thrombus, male gender, and separation of subvalvular apparatus portended a significantly higher likelihood of poor postoperative symptomatic status (p less than 0.0005). Preoperative mild mitral regurgitation, E to F slope on the M-mode echocardiogram, and tricuspid annuloplasty had significant influence on the need for late reoperation (p less than 0.05). Postoperative atrial fibrillation, mitral valve amplitude on the M-mode echocardiogram, preoperative embolism, and residual mitral incompetence had an independent predictive power for postoperative thromboembolism (p less than 0.05). Finally, preoperative atrial fibrillation, preoperative cardiothoracic ratio, postoperative left atrial size, and postoperative atrial fibrillation all influenced the probability of long-term complications. These results suggest that earlier operation should be considered in patients with mitral stenosis, to increase the complication-free survival rate.

Actuarial Analysis↗
PubMed1988

Mitral and aortic valve decalcification by ultrasonic energy. Experimental report.

In this investigation we used ultrasonic energy to decalcify 10 mitral and six aortic valves after they had been surgically removed. The calcium was disintegrated in all cases and normal valvular tissue was preserved. The fragments of disintegrated calcium were collected in a suction bottle, which prevented peripheral embolism. The ultrasonic urologic probe is an unwieldy instrument for cardiac surgery, and we suggest the manufacture of a new probe for clinical use in our specialty.

Aortic Valve↗
PubMed1987

Conservative operation for mitral stenosis with densely fibrosed or partially calcified valves. An eight-year evaluation.

Of 284 patients undergoing open mitral commissurotomy for mitral stenosis from January 1978 to December 1985, 81 patients had a densely scarred or partly calcified valve. In this study, we evaluated the postoperative results in these 81 patients. There were no operative or late deaths. Seventy-seven patients (95%) are in Functional Class I or II. Three patients required reoperation 3, 30, and 50 months after the initial procedure because of moderate or severe residual mitral regurgitation. After valvotomy there were four episodes of embolism. The actuarial rate of freedom from any complication (mortality, reoperation, congestive heart failure, and thromboembolic events) was 89.3% +/- 3.9% (mean +/- standard error of the mean) 8 years after operation. We conclude that for a follow-up period of 8 years, the stenotic mitral valve with anatomical deformities can be salvaged with satisfactory results. Therefore, we believe that this approach, at present, is a better alternative than prosthetic replacement with any type of valve presently available.

Adult↗