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Biomedical subjects

A Rodríguez

Publications and source records attributed to A Rodríguez.

At least 55 records · Page 3Linked to original sources
PubMed2004

Free ion yield observed in liquid isooctane irradiated by gamma rays. Comparison with the Onsager theory.

We have analysed data on the free ion yield observed in liquid isooctane irradiated by 60Co gamma rays within the framework of the Onsager theory about initial recombination. Several distribution functions describing the electron thermalization distance have been used and compared with the experimental results: a delta function, a Gaussian-type function and an exponential function. A linear dependence between the free ion yield and the external electric field has been found at low-electric-field values (E < or = 1.2 x 10(3) V mm(-1)) in excellent agreement with the Onsager theory. At higher electric field values, we obtain a solution in power series of the external field using the Onsager theory.

Cobalt Radioisotopes↗
PubMed2004

The designer drug situation in Ibiza.

A total of 137 urine samples and 46 serum samples, corresponding to 154 self-confessed designer drugs consumers in Ibiza island, were analyzed for the presence of designer drugs: amphetamine and amphetamine derivatives (methamphetamine, methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), methylenedioxyamphetamine (MDA), p-methoxymethylamphetamine (PMMA), p-methoxyamphetamine (PMA), etc.), ketamine and gamma-hydroxybutyric acid. Among this population, coming both from the forensic clinic and from the emergency room of a hospital, a total of 99 cases were found positive for some designer drug. This study shows the prevalence of methylenedioxymethamphetamine (MDMA) among designer drug users, sole or in association with other drugs. Also, the mixture of MDMA with other designer drugs, ethanol and/or cocaine is shown to be more likely to produce toxic symptoms requiring clinical attendance in a hospital emergency room. These findings along with the consumption history, the concentrations of drugs and metabolites in urine and serum and the toxicological significance for the interpretation of some MDMA metabolites such as 4-hydroxy-3-methoxymethamphetamine (HMMA) are discussed in this study.

Designer Drugs↗
PubMed2004

Characterization of allergens secreted by Anisakis simplex parasite: clinical relevance in comparison with somatic allergens.

BACKGROUND: Diagnostic methods for the study of allergic reactions to Anisakis simplex (A.s.) based on whole-body extracts of the larva are clearly insufficient. OBJECTIVES: To study the allergenicity of the proteins secreted by the parasite. Comparison with somatic antigens and determination of their clinical importance in allergic patients were also addressed. METHODS: An excretory/secretory (E/S) extract was produced by culturing third-stage A.s. larvae. It was used to perform immediate skin tests and to determine specific IgE in 10 patients diagnosed with allergy to A.s. Both tests were compared with the results obtained with the whole-body extract (somatic (S)). The molecular weight (MW) of their allergens was determined by immunoblotting, and a single-blind placebo-controlled oral challenge with E/S proteins was performed. Finally, allergens' resistance to gastric pepsin and acid pH was explored. RESULTS: A.s. larvae secreted allergens more potent than those present in the S extract. The skin prick test wheal area produced by E/S molecules and the absorbance obtained in the determination of specific IgE with these allergens (ELISA) were 5.8 times bigger than those obtained with S extract. MW allergens of 72 and 56 kDa in E/S extracts and those of 56, 48 and 43 kDa in S extract were recognized by more than 50% of the patients. Partial cross-reactivity between them was revealed by immunoblotting inhibition studies. Oral challenge with E/S extract (up to 479 microg) was negative in all the patients. Treatment of E/S proteins with gastric pepsin inhibited the binding of the E/S allergens for specific IgE. The acid pH did not affect the overall binding of IgE to E/S extract. It decreased by 15.23% and 19.96% at pH 4 and 2, but the difference was not statistically significant. CONCLUSION: A.s. secretes allergens more potent than somatic antigens and should be used in the diagnostic procedures. These allergens are inactivated by the pepsin, which supports the theory that live larva is necessary to induce an allergic reaction in most of the patients.

Adult↗
PubMed2004

Safety and efficacy of antimicrobial peptides against naturally acquired leishmaniasis.

Leishmaniases, which are important causes of morbidity and mortality in humans and dogs, are extremely difficult to treat. Antimicrobial peptides are rarely used as alternative treatments for naturally acquired parasitic diseases. Here we report that the acylated synthetic antimicrobial peptide Oct-CA(1-7)M(2-9) is safe and effective for treating naturally acquired canine leishmaniasis.

Animals↗
PubMed2004

Morbid obesity and gastric bypass surgery: biochemical profile.

BACKGROUND: Morbid obesity (MO) and the pathologies associated with it constitute an important public health problem, accounting for 7% of the health expenditure in industrialized countries. An important percentage of this expense is attributed to the different biochemical tests performed in these patients, who suffer from several metabolic derangements. We evaluated the basic biochemical abnormalities in MO patients and their reversibility by weight loss after gastric bypass, to standardize the surveillance of the different metabolic abnormalities in obese patients. METHODS: By a retrospective analysis on 125 patients operated in our hospital, we evaluated anthropometric and biochemical data before and 1, 3, 6, 12 and 24 months after gastric bypass. RESULTS: Preoperatively hyperinsulinemia, hyperglycemia, dyslipidemia and hypertensive disease were present, and began to improve 1 and 3 months after surgery (although not significantly) and significantly at 6, 12 and 24 months after it. We also observed deficient protein nutrition and a deficiency of micronutrients both before bypass and during the follow-up. CONCLUSION: After gastric bypass, a marked decrease in insulin occurred, with normalization of blood pressure and the biochemical parameters associated with the metabolic syndrome. We propose a biochemical follow-up protocol for MO patients.

Adolescent↗
PubMed2004

Epidemiology of urticaria in Spain.

BACKGROUND: In spite of the frequency of chronic urticaria there are very few epidemiological studies of its prevalence and distribution. OBJECTIVE: We wanted to approach the real prevalence of chronic urticaria in a population-based study and to depict demographic distribution and personal perception of the disease. We also wanted to describe the frequency of acute urticaria episodes in the population studied. METHODS: We conducted a population-based study among adults in Spain. We questioned 5003 individuals after calculating a sample size for a maximum variability (conservative approach p=q=0.5). RESULTS: We found a 0.6% (95% CI: 0.4-0.8) prevalence of chronic urticaria. The prevalence is significantly higher in women than in men with a OR=3.82 (95%CI 1.56-9.37). Chronic urticaria is a self-limited disease, yet in 8.7% of cases chronic urticaria lasts from one to 5 years and in 11.3%, for more than 5 years. The average age of onset is 40 years. CONCLUSIONS: We offer large epidemiology study data on the prevalence of chronic urticaria. The prevalence of chronic urticaria has not yet been defined in an adult population-based study. With this work we offer such data to describe the prevalence and features of this disease.

Adolescent↗
PubMed2003

Immunostimulant properties of a cell wall-modified whole Saccharomyces cerevisiae strain administered by diet to seabream (Sparus aurata L.).

The possible differences in the immunostimulant effects between whole wild Saccharomyces cerevisiae and a mutant strain (fks-1) administered in the diet to gilthead seabream (Sparus aurata L.) were studied. Fish were fed diets containing 0 (control) or 10 g whole wild yeast or fks-1 strain per kilogram feed for 2, 4 or 6 weeks. After each sampling, the innate humoral (complement, lysozyme and peroxidases) and cellular (intracellular peroxidases, phagocytosis, respiratory burst activity and cytotoxicity) responses were determined. Among the humoral responses, serum peroxidases and complement activity were significantly decreased after 6 weeks of feeding with the fks-1 strain-supplemented diet, while lysozyme activity increased after 2 and 4 weeks of feeding the fks-1 strain. Of the cellular responses studied, phagocytosis was increased to a significant degree at all the assayed times but only by the fks-1 strain-supplemented diet, while respiratory burst activity (after 4 weeks) and natural cytotoxicity (after 4 and 6 weeks) increased with either yeast strain. The intracellular peroxidase content was not affected by the dietary supplementation of either yeast strain. These results are discussed with a view to assessing the possible use of wild and/or mutant yeast strains for immunostimulant purposes in aquaculture.

Adjuvants, Immunologic↗
PubMed2003

Combination of low-dose cisplatin and gemcitabine for treatment of elderly patients with advanced non-small-cell lung cancer.

PURPOSE: To evaluate the feasibility, toxicity and efficacy of the combination of low-dose cisplatin (CDDP) and gemcitabine (GEM) in elderly patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This phase II trial included 46 patients aged 70 years or older with previously untreated advanced NSCLC. All patients were evaluable for response and toxicity. Treatment consisted of CDDP 50 mg/m(2) on day 1 plus GEM 1000 mg/m(2) on days 1 and 8. The regimen was repeated every 21 days. Patients received a minimum of three courses unless progressive disease was detected. RESULTS: A total of 190 GEM-CDDP courses were administered (median 4.1 courses per patient). The chemotherapy regimen was well tolerated. No patients developed grade 4 toxicity. Grade 3 toxicities were as follows: neutropenia in six patients (13%), and anemia, thrombopenia and nausea/vomiting in one (2%) each. Two patients (4%) had mild nephrotoxicity. Of the 46 patients, 16 had a partial response (35%, 95% confidence interval, CI, 28-52%), 17 (37%) remained stable and 13 (28%) had disease progression. Eastern Cooperative Oncology Group performance status improved in 17 patients (37%), whereas 25 (54%, 95% CI 44-74%) showed a clinical benefit. Median time to progression was 20 weeks. Overall median survival was 44 weeks, with a 1-year actuarial survival rate of 35%. CONCLUSIONS: The combination of low-dose CDDP and GEM for elderly patients with advanced NSCLC is an effective and well-tolerated chemotherapeutic approach.

Aged↗
PubMed2003

Intoxication due to 1,4-butanediol.

We report a case of intoxication resulting from the ingestion of a liquid, sold in the illicit market as "liquid ecstasy," which was found to contain 1,4-butanediol, a metabolic precursor of gamma-hydroxybutiric acid (GHB). Identification of the substance in the liquid was performed by gas chromatography-mass spectrometry (GC-MS). The toxicological analysis of blood, urine and gastric content of the victim was performed by immunoassay and gas chromatography with nitrogen-phosphorus detection as screening techniques and by means of GC-MS for confirmation and quantitation of 1,4-butanediol and GHB. The following drug concentrations were found: 82 microg/ml (blood), 401 microg/ml (urine) and 7.4 microg/ml (gastric content) for 1,4-butanediol and 103 microg/ml (blood), 430.0 microg/ml (urine) for GHB. In addition to these, other drugs detected and their blood concentration found in this case were methylenedioxymethylamphetamine (MDMA) 0.23 microg/ml and its metabolite methylenedioxyphenylamphetamine (MDA) 0.10 microg/ml. In the urine, a concentration of 0.10 microg/ml of benzoylecgonine was also found.

Butylene Glycols↗
PubMed2003

Anderson transition in low-dimensional disordered systems driven by long-range nonrandom hopping.

The single-parameter scaling hypothesis predicts the absence of delocalized states for noninteracting quasiparticles in low-dimensional disordered systems. We show analytically, using a supersymmetric method combined with a renormalization group analysis, as well as numerically that extended states may occur in the one- and two-dimensional Anderson model with a nonrandom hopping falling off as some power of the distance between sites. The different size scaling of the bare level spacing and the renormalized magnitude of the disorder seen by the quasiparticles finally results in the delocalization of states at one of the band edges of the quasiparticle energy spectrum.

Journal Article↗
PubMed2003

A mannose-receptor is possibly involved in the phagocytosis of Saccharomyces cerevisiae by seabream (Sparus aurata L.) leucocytes.

In this paper the possible involvement of the mannose-receptor on the non-specific recognition and phagocytosis of heat killed yeast cells (Saccharomyces cerevisiae) by gilthead seabream (Sparus aurata L.) head-kidney leucocytes was established by studying the ability of different sugars to inhibit the uptake of the yeast cells by leucocytes. Leucocytes were preincubated for 30min with different concentrations of sugar (alpha-mannan, d-mannose, d-fucose, l-fucose, d-glucose, d-glucosamine and n-acetyl-glucosamine, all of them described as specific ligands of the vertebrate mannose-receptor) and afterwards incubated with FITC-labelled yeast cells for phagocytosis assays. The phagocytic ability (percentage of cells with one or more ingested yeast cells within the total cell population) and capacity (number of ingested yeast cells per cell) of leucocytes was analysed by flow cytometry. The results demonstrate the potential existence of a specific receptor-sugar or receptor-yeast cell binding process, which was saturable, specific and dose-dependent. More specifically, when leucocytes were preincubated with appropriate doses of d-mannose, d- or l-fucose, d-glucose or n-acetyl-glucosamine the phagocytosis of yeast cells by head-kidney leucocytes was partially blocked. Seabream leucocytes were also preincubated with chloroquine, a lysosomotropic drug which downregulates (in a nonspecific manner) the expression of mannose-receptors in mammals, before phagocytosis assays were performed. The results demonstrated that the phagocytosis of yeast was completely blocked by this substance. The overall results seem to corroborate the presence of the mannose-receptor in seabream phagocytes, which is involved in the non-specific binding and phagocytosis of yeast cells by head-kidney leucocytes.

Agglutination↗
PubMed2003

Adipose tissue as an endocrine organ: role of leptin and adiponectin in the pathogenesis of cardiovascular diseases.

Obesity, the most common nutritional disorder in industrial countries, is associated with increased cardiovascular mortality and morbidity. Nevertheless, the molecular basis linking obesity with cardiovascular disturbances have not yet been fully clarified. Recent advances in the biology of adipose tissue indicate that it is not simply an energy storage organ, but also a secretory organ, producing a variety of bioactive substances, including leptin and adiponectin, that may influence the function as well as the structural integrity of the cardiovascular system. Leptin, besides being a satiety signal for the central nervous system and to be related to insulin and glucose metabolism, may also play an important role in regulating vascular tone because of the widespread distribution of functional receptors in the vascular cells. On the other hand, the more recently discovered protein, adiponectin, seems to play a protective role in experimental models of vascular injury, in probable relation to its ability to suppress the attachment of monocytes to endothelial cells, which is an early event in the atherosclerotic process. There is already considerable evidence linking altered production of some adipocyte hormones with the cardiovascular complications of obesity. Therefore, the knowledge of alterations in the endocrine function of adipose tissue may help to further understand the high cardiovascular risk associated with obesity.

Adiponectin↗
PubMed2003

[Gastrointestinal bleeding after endoscopic treatment of polypoid hamartoma (adenoma of Brunner's glands)].

The incidence of polypoidal tumors in the duodenum is scarce and Brunner's gland tumors represent 11% of these proliferations. Brunner's gland polypoid hamartoma or adenoma is a highly infrequent benign polypoid proliferation of Brunner's glands that is usually asymptomatic, although gastrointestinal bleeding or intestinal obstruction may sometimes occur. We present the case of a woman with an incidental diagnosis of duodenal polypoid hamartoma. The lesion was resected with polypectomy loop and at 48 h, the patient presented gastrointestinal bleeding as a complication. We describe the endoscopic treatment of the lesion and this complication.

Adult↗
PubMed2003

Optimization of hydrogen peroxide in totally chlorine free bleaching of cellulose pulp from olive tree residues.

The influence of the operating conditions used in the bleaching of olive wood trimmings pulp (viz. hydrogen peroxide concentration and time) on the yield, kappa index and viscosity of the resulting pulp and on strength-related properties of paper sheets was studied to determine the optimal bleaching conditions of this pulp. Hydrogen peroxide bleached pulps at different sequences (oxygen, ozone, chlorine dioxide and alkaline extractions) were compared. Hydrogen peroxide bleaching proved to be suitable for this pulp. Considerable improvements in viscosity were obtained with respect to other bleaching sequences such as oxygen, ozone and chlorine dioxide. Hydrogen peroxide bleaching decreased the kappa index 51.3% less than ozone bleaching, 25.0% less than chlorine dioxide (D) and 6.3% less combined chlorine dioxide-alkaline extraction (DE). To obtain kappa indices 50.9% and 37.9% lower than the index achieved by hydrogen peroxide, oxygen (LaO(p)) and ozone (LaO(LaZ)R) sequences respectively were needed. Lower-medium levels of hydrogen peroxide concentrations (1-3%) and high reaction times (210 min) proved to be suitable for bleaching of pulp olive trimming residues. This approach could be used on this residue to produce adequately bleached pulp.

Cellulose↗