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R Rodríguez

Publications and source records attributed to R Rodríguez.

At least 127 records · Page 7Linked to original sources
PubMed1998

[Aneurysms of the left ventricle. Surgical treatment].

Left ventricular aneurysm as a complication of myocardial infarction is observed in 10% of patients. In recent years, all surgical teams have observed a significant decrease of this complication. There is no doubt that this is due to the current medical treatment in the acute phase of myocardial infarction. Surgical treatment is considered only when the ventricular aneurysm presents complications such as congestive heart failure, thromboembolism, malignant ventricular arrhythmias or angina. In this review, we comment on the principle surgical procedures reported up to now. The indication of surgery is based on good functional results and long-term survival.

Heart Aneurysm↗
PubMed1997

Involvement of the C-terminal domain of an ATP-binding subunit in the regulation of the ABC-type nitrate/nitrite transporter of the Cyanobacterium synechococcus sp. strain PCC 7942.

In Synechococcus sp. strain PCC 7942, an ATP-binding cassette transporter encoded by the genes nrtA, nrtB, nrtC, and nrtD mediates active transport of nitrate and nitrite, which is inhibited by ammonium, a preferred source of nitrogen for the cyanobacterium. One of the ATP-binding subunits of the transporter, NrtC, has a distinct C-terminal domain of 380 amino acid residues. A mutant NC2, constructed by removal of this domain using genetic engineering techniques, assimilated low concentrations of nitrate and nitrite and accumulated nitrate intracellularly, showing that the domain is not essential for the transporter activities. Assimilation of low concentrations of nitrite was only partially inhibited by ammonium in NC2 but was completely inhibited in the wild-type cells. Cells of NC2 and its derivative (nitrate reductase-less strain NC4) carrying the truncated NrtC but not the cells with the wild-type NrtC accumulated nitrate intracellularly in the presence of ammonium in medium. These findings indicated that the C-terminal domain of NrtC is involved in the ammonium-promoted inhibition of the nitrate/nitrite transporter. In the presence of ammonium, NC2 could not assimilate nitrate despite its ability to accumulate nitrate intracellularly, which suggested that reduction of intracellular nitrate by nitrate reductase is also subject to inhibition by ammonium.

ATP-Binding Cassette Transporters↗
PubMed1997

Actions of compounds manipulating the nitric oxide system in the cat primary visual cortex.

1. We iontophoretically applied NG-nitro-L-arginine (L-NOArg), an inhibitor of nitric oxide synthase (NOS), to cells (n = 77) in area 17 of anaesthetized and paralysed cats while recording single-unit activity extracellularly. In twenty-nine out of seventy-seven cells (38%), compounds altering NO levels affected visual responses. 2. In twenty-five out of twenty-nine cells, L-NOArg non-selectively reduced visually elicited responses and spontaneous activity. These effects were reversed by co-application of L-arginine (L-Arg), which was without effect when applied alone. Application of the NO donor diethylamine-nitric oxide (DEA-NO) produced excitation in three out of eleven cells, all three cells showing suppression by L-NOArg. In ten cells the effect of the soluble analogue of cGMP, 8-bromo-cGMP, was tested. In three of those in which L-NOArg application reduced firing, 8-bromo-cGMP had an excitatory effect. In six out of fifteen cells tested, L-NOArg non-selectively reduced responses to NMDA and alpha-amino-3-hydroxy-5-methylisoxasole-4-propionic acid (AMPA). Again, co-application of L-Arg reversed this effect, without enhancing activity beyond control values. 3. In a further subpopulation of ten cells, L-NOArg decreased responses to ACh in five. 4. In four out of twenty-nine cells L-NOArg produced the opposite effect and increased visual responses. This was reversed by co-application of L-Arg. Some cells were also affected by 8-bromo-cGMP and DEA-NO in ways opposite to those described above. It is possible that the variety of effects seen here could also reflect trans-synaptic activation, or changes in local circuit activity. However, the most parsimonious explanation for our data is that NO differentially affects the activity of two populations of cortical cells, in the main causing a non-specific excitation.

Acetylcholine↗
PubMed1997

Purification, amino acid sequence and immunological characterization of Ole e 6, a cysteine-enriched allergen from olive tree pollen.

The Ole e 6 allergen from olive tree pollen has been isolated by combining gel permeation and reverse-phase chromatographies. It is a single and highly acidic (pI 4.2) polypeptide chain protein. Its NH2-terminal amino acid sequence has been determined by Edman degradation. Total RNA from the olive tree pollen was isolated, and a specific cDNA was amplified by the polymerase chain reaction using a degenerate oligonucleotide primer designed according to the NH2-terminal sequence of the protein. The nucleotide sequencing of the cDNA rendered an open reading frame encoding a 50 amino acid polypeptide chain, in which two sets of the sequential motif Cys-X3-Cys-X3-Cys are present. No sequence similarity has been found between this protein and other previously described polypeptides.

Allergens↗
PubMed1997

Testing topographic differences between event related brain potentials by using non-parametric combinations of permutation tests.

MANOVA and repeated measures ANOVA approaches have provided evidence of a number of limitations in several event-related potential (ERP) studies due to violations of their statistical assumptions and the typically moderate size of the available sample. Alternative, computer-intensive methods based on permutation principles have recently been developed. Up to now this methodology has focused mostly on magnitude differences between scalp distributions as measured by t statistics. In this paper the scope of permutation techniques in ERP analysis was widened. A new statistic (D statistic) is introduced to compare the shapes of scalp distributions of ERPs. Additionally a general non-parametric combinatory technique is introduced to evaluate, by means of multivariate permutation tests, several time points and/or recording sites in ERP data. The methodology described here was used to test if two ERP components elicited during word-pair matching tasks to semantic or phonological incongruences had different scalp distributions.

Adolescent↗
PubMed1997

Platanus pollen as an important cause of pollinosis.

OBJECTIVE: The existence of Platanus pollinosis is not generally accepted despite the production of very large quantities of airborne Platanus pollen in many cities of the United States and Europe. The aim of this study was to investigate if Platanus pollen really contributes to the symptoms of the patients with pollinosis in the Madrid area. METHODS: We carried out systematic skin prick testing with Platanus pollen extract on 47 patients seen in our allergy center with spring-summer pollinosis symptoms. Each patient maintained symptom score diaries before, during, and after the Platanus pollination season. The average symptom scores were calculated and compared with the Platanus pollen counts. Measurements of specific IgE by ELISA and immunoblotting also were performed in each patient. RESULTS: The Platanus skin tests were positive in 33 of the 39 patients first seen with seasonal symptoms during Platanus pollen season and only in three of the eight patients without symptoms during Platanus exposure (Fisher's exact test; p < 0.05). Twenty-two of the 33 Platanus-positive skin test patients also had a positive ELISA result. Furthermore, the average 24-hour rhinitis symptom scores of the 39 patients first seen with seasonal symptoms during March through April showed significant correlation with Platanus pollen counts (r(s) = 0.57, p < 0.05). The immunoblot results suggest that a 17 kd pollen protein could be a major allergen in patients with Platanus pollinosis. CONCLUSIONS: Platanus pollen is an important cause of pollinosis in Madrid. A protein with a molecular weight of 17 kd appeared to be its major allergen.

Adolescent↗
PubMed1997

Dental enamel defects in celiac patients.

OBJECTIVE: The incidence and distribution of enamel defects among patients with celiac disease were examined. STUDY DESIGN: The oral cavity was explored in 137 patients with celiac disease (mean age 16.2 years; age range 5 to 68 years) and in 52 control patients (mean age 19.8 years; age range 5 to 64 years). Permanent dentition enamel defects were recorded, along with their number and locations. The decayed, missing, and filled teeth index rates were also established, and an investigation was made of the human leukocyte antigens among the patients with celiac disease. The results obtained were analyzed with the chi-squared test, statistical significance being regarded for p < or = 0.05. RESULTS: Enamel defects were observed in 72 (52.5%) of the patients with celiac disease (52 patients had systematic defects) and in 22 (42.3%) of the control patients (9 patients had systematic defects). Systematic defects were significantly more common in the celiac disease group. In the patients with celiac disease, 72.2% were symmetrical, compared with 40.9% of the defects in the control patients. The incisors were the most frequently affected teeth, the extent of involvement being significantly greater in the celiac disease group. In patients with celiac disease, DR7, DR3, and DQ2 were the most commonly observed human leukocyte antigens. The mean decayed, missing, and filled teeth index rates were 4.8 and 6.2 in the celiac disease group and the control group, respectively. CONCLUSIONS: Enamel defects are common among patients with celiac disease. They tend to be bilateral and symmetrical, and they are chronologically distributed. The lesions affect mainly the incisors and the molars. Patients with such characteristics should be evaluated for possible celiac disease.

Adolescent↗
PubMed1997

Detection, isolation and complete amino acid sequence of an aeroallergenic protein from rapeseed flour.

BACKGROUND: Seed proteins have been found to cause hypersensitivity by ingestion or inhalation. Rapeseed flour was responsible for allergic symptoms in a patient, who develops into allergy to mustard spice. OBJECTIVE: To determine the presence of allergenic proteins in rapeseed flour, and analyse the structure of the main component and its crossreactivity with the mustard allergen. METHODS: SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and subsequent immunoblotting with a serum from a rapeseed allergic patient were performed to detect IgE-binding proteins. Proteolytic digestions and high performance liquid chromatography were used to obtain the peptides from the allergenic BnIII napin from rapeseed flour. Automatic Edman degradations were carried out to determine their amino acid sequences, which were compared with other sequences in nucleotide and amino acid sequence databases. Crossreactivity assays were carried out by ELISA inhibition using sera from a rapeseed allergic patient and from patients allergic to mustard. RESULTS: The 2S albumins of rapeseed were recognized by the serum from a patient allergic to this seed. The most abundant isoform of the allergenic napins, BnIII, was used for structural and immunological analysis. The protein consists of two different chains of 9.5 and 4.5 kDa. Their complete amino acid sequences were determined. The protein exhibited structural relationships with other napin-like storage proteins from seeds. IgE and IgG crossreactivity between rapeseed and mustard allergens was also demonstrated. Considering the structural and immunological data, certain polypeptide regions are suggested to be involved in the allergenicity of these proteins. CONCLUSIONS: Rapeseed contains 2S storage proteins which may cause allergy in hypersensitive individuals. These proteins exhibit great sequence similarity with 2S albumins from different seeds. Crossreactivity between mustard and rapeseed flours can be explained by sequence homology.

2S Albumins, Plant↗
PubMed1997

Influence of chronic prenatal and postnatal administration of naltrexone in locomotor activity induced by morphine in mice.

The influence of chronic pre- and postnatal naltrexone exposure on the sensitivity of offspring to the locomotor effects of morphine was investigated in C-57 Black mice. Pregnant mice were injected subcutaneously (sc) with either saline (0.1 ml/10 g) or naltrexone (10 mg/kg) twice daily during gestation and throughout lactation, 21 days postpartum. One, three and seven weeks after birth, male offspring were tested for locomotor activity. At 7 weeks of age, dose-response curves were obtained with morphine (10, 31.6, and 100 mg/kg) and amphetamine (0.31, 10 and 31.6 mg/kg) in naltrexone-pretreated and in saline-treated animals. Naltrexone exposure during gestation and lactation resulted in an augmented sensitivity of offspring to the locomotor activity-increasing effects of morphine. In these animals, the dose-response relationship for the effect of morphine on locomotor activity was displaced to the left about threefold. In contrast, naltrexone exposure did not alter the sensitivity of offspring to amphetamine. It was also found that offspring of naltrexone-treated animals have significantly greater spontaneous locomotor activity than that of the offspring of saline-treated mothers. The increased locomotor activity persisted for at least 4 weeks after the last injection of naltrexone. These findings indicate that chronic opioid receptor blockade during gestation and early postnatal development induces supersensitivity to the locomotor effects of morphine and is associated with long-lasting behavioral alterations.

Amphetamine↗
PubMed1997

[Severe syndrome of ovarian hyperstimulation. Incidence, value of criteria of risk factors and preventive methods].

Statistical analysis; square Chi test, Pearson, were practiced, from 1994 to 1996. There were 368 hyperstimulated cycles; three SHOS cases without risk factors and 28 cases with risk factors without SHOS. Risk factors presented were: average seric estradiol 6643.59 +/- 2320 pg/ ml; average follicles: 26.6 +/- 6.9; ovules recuperated by aspiration: 19.32 +/- 9.1. There were five groups according to preventive methods: albumin (13 patients, coasting (one patient); albumin-coasting (11 pacientes); albumin-embryo freezing (3 patients); embryo freezing (one patient). None of the patients presented SHOS.

Analysis of Variance↗
PubMed1997

Viral isolation from cases of epidemic neuropathy in Cuba.

OBJECTIVE: To investigate the possibility of a viral agent in the central nervous system of patients with epidemic neuropathy. DESIGN: Virus isolation attempts, in cell cultures and suckling mice, from cerebrospinal fluid (CSF) of neuropathy patients and controls undergoing lumbar puncture for unrelated reasons. Serologic studies in patients, contacts, and controls. SETTING: An epidemic of optic and peripheral neuropathy affected more than 50,000 people in Cuba in 1991 through 1993. Illness was associated with dietary limitations and increased physical demands accompanying the shortages of food and fuel experienced in Cuba since 1989. Most patients responded to parenteral vitamin therapy, and the epidemic began to subside when oral vitamin supplementation was begun for the entire Cuban population. RESULTS: Coxsackievirus A9 (five isolates) and a similar, less cytopathic virus (100 isolates) were recovered from 105 (84%) of 125 CSF specimens from neuropathy patients. The strains with light cytopathic effect were antigenically related to Coxsackieviruses A9 and B4 by cross-neutralization and immunoblotting assays. Virus persisted in CSF of some patients for 1 to 12 months. Cerebrospinal fluid from patients and both types of virus from cell culture produced illness, including complete posterior flaccid paralysis, in newborn mice, and virus was reisolated from the mice. Mouse tissues and sural nerve biopsy specimens from patients were stained by immunoperoxidase and colloidal gold techniques using hyperimmune rabbit antisera against the virus with light cytopathic effect. CONCLUSIONS: Coxsackievirus A9 or an antigenically related agent with a light cytopathic effect was present in CSF of 84% of 125 patients with epidemic neuropathy. The role of these agents, probably in combination with nutritional factors, in the pathophysiology of the disease requires further investigation.

Adult↗
PubMed1997

Neonatal lupus erythematosus.

This is a case of an infant with neonatal lupus erythematosus who presented the characteristic cutaneous lesions without evidence of systemic involvement. NLE is a rare condition which affects newborn infants from mothers who may me asymptomatic or have a connective tissue disease, with or without autoantibodies to extractable nuclear antigens Ro (SS-A), LA (SS-B) or ribonucleoproteins. The skin lesions are usually annular in configuration and resemble those of subacute cutaneous lupus erythematosus. Congenital complete heart block (CHB) may be present in addition to the cutaneous lesions. This is a review of NLE focusing on its clinical manifestations, serologic markers, pathogenesis and treatment.

Female↗
PubMed1997

[Virological diagnosis of an outbreak of fever and rashes caused by parvovirus B19, Cuba, 1995].

The results obtained in the study of an a outbreak of fever and rash occurred in Havana City in March, 1995, are reported. Dengue, measles, rubella, herpes simplex, and Epstein Barr were discarded as causal agents of the outbreak in the samples of 35 patients. Parvovirus B19 was identified as the causing agent of the outbreak by the detection of IgM antibodies and the polymerase chain reaction technique (PCR). The infection produced by this agent was confirmed in 14/18 samples (77.7%) by some of the techniques used. This study makes reference to the first outbreak of Parvovirus B19 that was proved in Cuba.

Adult↗
PubMed1996

1H NMR assignment and global fold of napin BnIb, a representative 2S albumin seed protein.

Napin BnIb is a representative member of the 2S albumin seed proteins, which consists of two polypeptide chains of 3.8 and 8.4 kDa linked by two disulfide bridges. In this work, a complete assignment of the 1H spectra of napin BnIb has been carried out by two-dimensional NMR sequence-specific methods and its secondary structure determined on the basis of spectral data. A calculation of the tertiary structure has been performed using approximately 500 distance constraints derived from unambiguously assigned NOE cross-correlations and distance geometry methods. The resulting global fold consists of five helices and a C-terminal loop arranged in a right-handed spiral. The folded protein is stabilized by two interchain disulfide bridges and two additional ones between cysteine residues in the large chain. The structure of napin BnIb represents a third example of a new and distinctive folding pattern first described for the hydrophobic protein from soybean and nonspecific lipid transfer proteins from wheat and maize. The presence of an internal cavity is not at all evident, which rules out in principle the napin BnIb as a carrier of lipids. The determined structure is compatible with activities attributed to these proteins such as phospholipid vesicle interaction, allergenicity, and calmodulin antagonism. Given the sequence homology of BnIb with other napins and napin-type 2S albumin seed proteins from different species, it is likely that all these proteins share a common architecture. The determined structure will be crucial to establish structure-function relationships and to explore the mechanisms of folding, processing, and deposition of these proteins. It will also provide a firm basis for a rational use of genetic engineering in order to develop improved transgenic plants.

2S Albumins, Plant↗
PubMed1996

Ole e 3, an olive-tree allergen, belongs to a widespread family of pollen proteins.

An allergen has been isolated from a saline extract of olive tree (Olea europaea) pollen. The protein consists of a single polypeptide chain of 9.2-kDa, as determined by mass spectrometry. It contains neither tryptophan nor tyrosine residues, and displays an acidic isoelectric point. The secondary structure of the protein, estimated from the analysis of the circular-dichroism spectrum in the peptide-bond region, is composed of 52% alpha-helix, 10% beta-strand, 29% beta-turn and 9% non-regular conformation. The N-terminal end of the protein is blocked. Amino-acid-sequence data have been obtained from peptides produced by CNBr treatment of the native allergen. A partial sequence of 36 amino acids has thus been elucidated. The protein exhibits sequence similarity with pollen allergens from Brassica species and contains a Ca(2+)-binding motif. The isolated protein displays IgE-binding activity against sera of patients allergic to olive-tree pollen. It has been named Ole e 3, according to the recommendations of the IUIS Nomenclature Committee. IgG ELISA inhibition assays with polyclonal antibodies specific for Ole e 3 reveal the presence of proteins similar to Ole e 3 in the pollen from non-related plant species, which may explain allergic cross-reactivity processes.

Allergens↗