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P Santamaría

Publications and source records attributed to P Santamaría.

At least 19 recordsLinked to original sources
PubMed2006

Effect of the addition of inert cellulose substrates to grape must on Saccharomyces cerevisiae diversity and the evolution of alcoholic fermentation.

AIMS: To study the addition of cellulose-based adjuvant as a resource to offset the negative effects produced by grape juice clarification during alcoholic fermentations. METHODS AND RESULTS: The effect of the addition of two kinds of inert cellulose substrates in white wine vinification was investigated in two different musts. In one of these musts, stuck fermentations were detected. One of the types of cellulose examined had a fining effect, which caused a decrease in the number of viable yeasts in the medium and altered the distribution and frequency of the clones, which performed the fermentation. The other cellulose substrate made the medium cloudier but did not alter the distribution of yeasts in comparison with the control. CONCLUSIONS: The behaviour of the inert cellulose substrates on vinification depends on its physical characteristics and its capacity for making the must cloudy. SIGNIFICANCE AND IMPACT OF THE STUDY: The addition of inert cellulose substrates in white wine vinification improves the fermentation process and the quality of wines obtained. This effect is more noticeable in difficult fermentations. One variety of cellulose showed an inhibitory effect on Torulaspora delbrueckii yeasts.

Acids↗
PubMed2000

Effects of inhaled glaucine on pulmonary responses to antigen in sensitized guinea pigs.

The alkaloid (S)-(+)-1,2,9,10-tetramethoxyaporphine (glaucine) is a phosphodiesterase 4 inhibitor with bronchodilator and anti-inflammatory activity in vitro. In this study, we examined the in vivo effects of glaucine on an animal model of asthma. In ovalbumin sensitized guinea pigs, inhaled glaucine (10 mg ml(-1), 3 min) inhibited the acute bronchoconstriction produced by aerosol antigen (antigen response was 256+/-42 and 95+/-14 cm H(2)O l(-1) s(-1) in control and glaucine-treated animals, respectively; P<0.05). Pretreatment with glaucine (10 mg ml(-1), 10 min inhalation, 30 min pre- and 3 h post-antigen exposure) markedly reduced airway hyperreactivity to histamine, eosinophil lung accumulation, and increased eosinophil peroxidase activity in bronchoalveolar lavage fluid 24 h after exposure of conscious guinea pigs to aerosol antigen. In addition, inhaled glaucine (5-10 mg ml(-1), 3 min) inhibited the microvascular leakage produced after inhaled antigen at all airway levels. These data support the potential interest of phosphodiesterase 4 inhibitors in asthma treatment.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

Genesis versus epigenesis: the odd jobs of the Polycomb group of genes.

Cells need the products of the Polycomb Group of genes (PcG) to keep, through development, the memory of their genetic determination. The pleiotropic mutant phenotypes of PcG genes strikingly resemble morphological traits, considered as taxonomic characters with phylogenetic meaning, used in Dipteran classification. I argue that spatial modulation of the multimeric complexes formed by PcG products has played a role or escorted the genesis of species.

Animals↗
PubMed1995

Characterization of a region of the X chromosome of Drosophila including multi sex combs (mxc), a Polycomb group gene which also functions as a tumour suppressor.

Genetic analysis of the 8D3;8D8-9 segment of the Drosophila melanogaster X chromosome has assigned seven complementation groups to this region, three of which are new. A Polycomb group (Pc-G) gene, multi sex combs (mxc), is characterized and mutant alleles are described. Besides common homeotic transformations characteristic of Pc-G mutants that mimic the ectopic gain of function of BX-C and ANT-C genes, mxc mutants show other phenotypes: they zygotically mimic, in males and females, the characteristic lack of germ line seen in progeny of some maternal effect mutants of the so-called posterior group (the grandchildless phenotype). Loss of normal mxc function can promote uncontrolled malignant growth which indicates a possible relationship between Pc-G genes and tumour suppressor genes. We propose that gain-of-function of genes normally repressed by the wild-type mxc product could, in mxc mutants, give rise to an incoherent signal which would be devoid of meaning in normal development. Such a signal could divert somatic and germ line development pathways, provoke the loss of cell affinities, but allow or promote growth.

Alleles↗
PubMed1993

Effects of vanadate on responses of guinea-pig isolated trachea to spasmogens.

The effects of vanadate on the contractility of the guinea-pig isolated trachea was examined. Vanadate (0.1 mM) produced a sustained contraction that was abolished in Ca(2+)-free EGTA (0.1 mM)-containing physiological salt solution but was resistant to verapamil (1 microM). Vanadate (0.1 mM) depressed tracheal responses to CaCl2 (in Ca(2+)-free depolarizing solution), KCl, acetylcholine, histamine and 5-hydroxytryptamine. For vanadate (10 microM), the inhibition of spasmogenic responses only reached statistical significance for histamine and 5-hydroxytryptamine. Caffeine (1 mM)-induced spasm (trachea at 20 degrees C in the presence of indomethacin (2.8 microM)) was not affected by vanadate (10 microM-0.1 mM). Vanadate (0.1 mM) slightly depressed the responses to KCl (50 mM), acetylcholine (1 mM), histamine (1 mM) or 5-hydroxytryptamine (0.1 mM) observed in Ca(2+)-free EGTA (0.1 mM)-containing physiological salt solution. Vanadate (0.5 mM) depressed Ca2+ (20 microM)-induced contraction of trachea which had been chemically skinned of its plasmalemmal membranes. The mechanism of the inhibitory effect of vanadate on tracheal responses to a variety of spasmogens remains obscure, but, under in-vitro conditions, vanadate clearly does not induce hyper-reactivity of airway smooth muscle to spasmogens.

Acetylcholine↗
PubMed1993

[Malignant melanoma of the nasal cavities. Our experience from two cases].

Malignant Melanoma of the nasal cavity is a rare occurrence. Its clinical manifestations at beginning are non-specific and its macroscopical appearance is variable due to the several pigmentation tonalities which render sometimes difficult the diagnosis. The confirmed diagnosis result from the histopathologic study of the tissue. The treatment is surgery, when the cases are operable, and radiotherapy, chemotherapy and immunotherapy either as adjuvant or as palliative management in inoperable cases.

Adult↗
PubMed1986

[Digestive system duplications].

Fifteen digestive duplications, corresponding to fourteen patients, have been surgically treated in "La Paz" Pediatric Hospital between 1966 and 1984. The most common localization (40%) was the large bowel. The first choice treatment was the complete excision of lesions, with led to cure of all patients. Embryologic theories and clinical forms are also reviewed.

Esophagus↗
PubMed1985

A common precursor for the two subunits of the penicillin acylase from Escherichia coli ATCC11105.

Penicillin acylase (PA) is an industrial enzyme that is used to convert penicillin G into a precursor for semisynthetic penicillins. We have cloned a segment of DNA that codes for the two subunits required for PA activity. We also report the nucleotide sequence of a DNA fragment that codes for (i) the small subunit, (ii) the N-terminal region of the large subunit and (iii) a putative connecting peptide. These results confirm the existence of a common precursor for both peptides.

Amidohydrolases↗
PubMed1980

Chimaeras of Drosophila melanogaster obtained by injection of haploid nuclei.

Since the observation by Bridges of a few mosaics containing haploid tissue in Drosophila, specimens supposedly haploid have rarely been found. A technique for the easy production of haploid animals or tissues could have important applications. We have now successfully designed such a technique by the production of chimaeras obtained by transplantation of haploid nuclei from a maternal effect mutant that produces haploid embryos. We have used this technique to test the proposal of Jack and Judd that the zeste locus of Drosophila melanogaster cannot repress the activity of unpaired alleles at the white locus.

Animals↗
PubMed1980

Distribution of ring-X chromosomes in the blastoderm of gynandromorphic D. melanogaster.

Embryos of the D. melanogaster strain producing gynandromorphs by loss of the ring-X chromosome were treated with vinblastine to obtain blastoderms with all mitoses arrested in metaphase, and with tetracaine to improve the resolution of chromosomes. Ring-X and ringless mitoses were recorded in the major part of the blastoderm in 18 eggs. Limits between females and male areas were very irregular and some embryos had several isolated areas of one type or the other. The proportion of male nuclei varied from 80.8 to 0.4%, indicating that there must have been more than one loss of the ring-X in most of the eggs and that losses occurred as late as the ninth division. When the percentages of male nuclei were compared with theoretical values, all the observed percentages could be accounted for by two losses. In early cleavages the lost ring could be found halfway between ringless mitoses. Examination of chromosomes in the three polar nuclei showed that the ring often remained undivided in meiosis. If the resulting ringless haploid group became a female pronucleus, an XO or YO embryo was produced after fertilization. We propose a hypothesis to explain the two losses.

Animals↗