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Biomedical subjects

P Rodríguez

Publications and source records attributed to P Rodríguez.

At least 19 recordsLinked to original sources
PubMed2006

Tellurium adatoms as an in-situ surface probe of (111) two-dimensional domains at platinum surfaces.

Irreversibly adsorbed tellurium has been studied as a probe to quantify ordered domains in platinum electrodes. The surface redox process of adsorbed tellurium on the Pt(111) electrode and Pt(111) stepped surfaces takes place around 0.85 V in a well-defined peak. The behavior of this redox process on the Pt(111) vicinal surfaces indicates that the tellurium atoms involved in the redox process are only those deposited on the (111) terrace sites. Moreover, the corresponding charge density is proportional to the number of sites on (111) ordered domains (terraces) that are, at least, three atoms wide. Hence, this charge density can be used to measure the number of (111) terrace sites on any given platinum sample. Structural information about tellurium adsorption is obtained from atomic-resolution STM images for the Pt(111) and Pt(10, 10, 9) electrodes. A rectangular structure (2 x radical 3) and a compact hexagonal structure (11 x 8) were identified. However, the redox peak for adsorbed tellurium on (100) domains at 1.03 V overlaps with peaks arising from steps and (110) sites. Therefore, it cannot be used without problems for the determination of (100) sites on a platinum sample. On the (100) terraces, the surface structure of the adsorbed tellurium is c(2 x 2), as revealed by STM. Finally, tellurium irreversible adsorption has been used to estimate the number of (111) ordered domains terrace sites on different polycrystalline platinum samples, and the results are compared to those obtained with bismuth irreversible adsorption.

Journal Article↗
PubMed2006

[Evaluation of the efficacy of a comprehensive programme of secondary prevention of cardiovascular disease in primary care: the PREseAP Study].

OBJECTIVES: To assess the efficacy of a comprehensive secondary prevention programme to reduce morbidity and mortality in patients who have suffered a cardiovascular (CV) event; to control CV risk factors and prophylactic treatment in order to prevent recurrence; and to improve the quality of life of patients with cardiovascular disease. DESIGN: Randomised, pragmatic, open clinical trial in primary care. SETTING: A total of 42 primary care centres of 8 different areas in Spain. PARTICIPANTS: Men and women below 86 years old, diagnosed with coronary disease and/or stroke and/or peripheral vascular disease in the preceding year, and who have no serious or terminal disease. INTERVENTION: Primary care centres will be randomised to following usual care (control group), or to following a comprehensive programme of secondary prevention (intervention group). MAIN MEASUREMENTS: Cardiovascular fatal events, cardiovascular non-fatal events, total mortality and health-related quality of life (SF-36).

Adult↗
PubMed2006

Air pollution and cardiovascular admissions association in Spain: results within the EMECAS project.

OBJECTIVE: To evaluate the short term effect of air pollution on cardiovascular admissions in 14 Spanish cities METHODS: The period under study was from 1995 to 1999. Daily emergency admissions for all cardiovascular diseases (CVD) and heart diseases (HD) were obtained from hospital records, and the corresponding daily levels of particulates, SO2, NO2, CO, and ozone were recorded. The magnitude of association was estimated using Poisson generalised additive models controlling for confounding and overdispersion. For each cause, lagged effects, up to three days, of each pollutant were examined and combined estimates were obtained. For ozone the analyses were restricted to the warm period. One and two pollutant models were performed. RESULTS: Associations were more consistent in lag 0 (concurrent day) and 1 (lag 0-1), except in the case of ozone where there was a more delayed relation (lag 2-3). For combined estimates an increase of 10 microg/m3 in the PM10 levels in lag 0-1 was associated with an increase of 0.9% (95% CI: 0.4 to 1.5%) in the number of hospital admissions for CVD, and 1.6% (0.8 to 2.3%) for HD. For ozone the corresponding estimates for lag 2-3 were 0.7% (0.3 to 1.0) for CVD, and 0.7% (0.1 to 1.2) for HD. An increase of 1 mg/m3 in CO levels was associated with an increase of 2.1% (0.7 to 3.5%) in CVD admissions, and 4.2% (1.3 to 7.1%) in HD admissions. SO2 and NO2 estimates were more sensitive in two pollutant models CONCLUSIONS: A short term association between increases in daily levels of air pollutants and the number of daily admissions for cardiovascular diseases, with specificity for heart diseases, has been described in Spanish cities.

Aged↗
PubMed2005

[Giant thymolipoma].

Thymolipoma is an uncommon benign tumor (accounting for 2% to 9% of thymus tumors). We present the case of a 26-year-old man who sought medical attention for left-sided pleural pain of 3 months duration. Computed tomography showed a mass in the left side of the chest occupying both the anterior mediastinum and the left pleural cavity. This mass caused lung collapse and mediastinal shift. Magnetic resonance imaging revealed a large fatty tumor and transthoracic biopsy with radiological guidance confirmed the diagnosis. The tumor was resected through a left thoracotomy. No postsurgical complications occurred and the histopathological diagnosis was thymolipoma.

Adult↗
PubMed2005

Biological dosimetry in a group of radiologists by the analysis of dicentrics and translocations.

The results of a cytogenetic study carried out in a group of nine radiologists are presented. Chromosome aberrations were detected by fluorescence plus Giemsa staining and fluorescence in situ hybridization. Dose estimates were obtained by extrapolating the yield of dicentrics and translocations to their respective dose-effect curves. In seven individuals, the 95% confidence limits of the doses estimated by dicentrics did not include 0 Gy. The 99 dicentrics observed in 17,626 cells gave a collective estimated dose of 115 mGy (95% confidence limits 73-171). For translocations, five individuals had estimated doses that were clearly higher than the total accumulated recorded dose. The 82 total apparently simple translocations observed in 9722 cells gave a collective estimated dose of 275 mGy (132-496). The mean genomic frequencies (x100 +/- SE) of complete and total apparently simple translocations observed in the group of radiologists (1.91 +/- 0.30 and 2.67 +/- 0.34, respectively) were significantly higher than those observed in a matched control group (0.53 +/- 0.10 and 0.87 +/- 0.13, P < 0.01 in both cases) and in another occupationally exposed matched group (0.79 +/- 0.12 and 1.14 +/-0.14, P < 0.03 and P < 0.01, respectively). The discrepancies observed between the physically recorded doses and the biologically estimated doses indicate that the radiologists did not always wear their dosimeters or that the dosimeters were not always in the radiation field.

Adult↗
PubMed2004

Clinical features of ten cases of osteopoikilosis.

A retrospective study was carried out of the ten cases of osteopoikilosis seen at this Orthopedic Unit over a 15-year period in order to determine the reasons why patients seek consultation, preliminary diagnosis, and associated lesions. Eight patients consulted for problems not related to the locomotor apparatus, and diagnosis was by chance; the other two presented joint pain. The preliminary diagnosis was osteoblastic metastasis in five patients and osteopoikilosis in the other five. None of the patients displayed skin or visceral involvement, but three presented bone alterations. Definitive diagnosis was made by measurement of biochemical markers of bone remodeling, radiography of both hands, and bone scan. Bone biopsy was performed in one case. Although rare, the radiographic symptoms of osteopoikilosis are sufficiently specific to avoid false diagnoses, which may give rise to rigorous and expensive studies for other important disorders.

Adult↗
PubMed2004

Plasma chemistry reference values from captive red-legged partridges (Alectoris rufa).

1. Haematological and plasma biochemical parameters of 66 captive red-legged partridges (Alectoris rufa) of both sexes were analysed in order to determine reference values, taking sex and age into account. 2. There were no statistically significant differences in haematocrit, plasma glucose content or creatine kinase activity either with age or between sexes. 3. Plasma cholesterol concentrations showed differences between sexes, whereas the plasma concentrations of urea, uric acid and creatinine were significantly affected by age. 4. Plasma triglyceride and total protein concentrations were affected by both sex and age. 5. A peak at 6 months old in those parameters related to protein metabolism, such as urea, uric acid and creatinine may be related to the end of the growing period and the start of ovulation after moulting.

Aging↗
PubMed2004

Analysis of translocations in stable cells and their implications in retrospective biological dosimetry.

The aim of the present study was to evaluate the influence of the exclusion of cells with unstable aberrations in the elaboration of dose-effect curves for translocations and their implications in biological dosimetry of past exposures. To establish dose-effect curves, peripheral blood samples were irradiated with 60Co gamma rays at ten different doses and the yield of translocations analyzed by FISH was considered in all cells and in stable cells (those without dicentrics, acentrics or rings). To discriminate transmissible translocations, the dose- effect curve for total apparently simple translocations in stable cells was chosen as the reference. In stable cells, dose- effect curves for apparently simple translocations without pseudosimple and complex-derived one-way patterns, tAbtBa and total translocations were obtained. None of these curves differed from the reference curve. When all cells were considered, only the curve for total translocations was significantly different from the reference curve. From the results obtained it can be concluded that the use of dose-effect curves for apparently simple translocations in stable cells and in all cells will give similar dose estimates in retrospective biological dosimetry studies. However, the use of dose-effect curves for total translocations in all cells will lead to underestimations of the dose mainly at high doses.

Adult↗
PubMed2004

[Intramuscular juvenile xantogranuloma].

Deep or intramuscular juvenile xanthogranuloma (JXG) is very rare. There are, however, some clinical and histological similarities between the case we present and the few cases that have been published in the literature. Although most of them will need histologic confirmation to establish the final diagnosis, surgeons who are operating tumors of infancy should consider it in the differential diagnosis of well circumscribed, rapidly growing dorsal masses in children under 3 years of age. Macroscopic appearance upon excision can help to support the diagnosis. Knowledge of this variant of JXG may avoid aggressive diagnostic or therapeutic procedures.

Female↗
PubMed2003

[Mediastinoscopy in the diagnosis of mediastinal disease. An analysis of 181 explorations].

To validate our experience with standard cervical mediastinoscopy (SCM) and extended cervical mediastinoscopy (ECM) to diagnose mediastinal nodes and masses, we studied 181 patients between January 1992 and February 2001. SCM and ECM were indicated for diagnostic staging of nodes related to bronchogenic carcinoma (Group I) or of mediastinal masses (Group II). An SCM was performed in all cases to explore the paratracheal region (2R, 2L, 4R, 4L, 7, 10R and 10L); in 21 additional cases, an ECM was performed to explore the aortopulmonary window or the subaortic region (area 5) and the para-aortic region (area 6). In Group I, the sensitivity of SCM was 93.6% and specificity was 100%; the positive predictive value (PPV) was 100%, the negative predictive value (NPV) was 82.8%, and the diagnostic yield was 95.1%. The sensitivity of ECM was 91% and specificity was 100%; PPV was 100%, NPV 93.3% and yield was 96%. In Group II, the sensitivity was 93.3%, specificity 100%, PPV 100%, NPV 81.2% and diagnostic yield 94.8%. The sensitivity of ECM in this group was 80%, specificity was 100%, PPV 100%, NPV 66.7% and yield 85.7%. A 2.7% complication rate was observed, with one case of bleeding after injury to the superior vena cava, one tracheal lesion, one recurring paralysis and two cases of surgical wound infection. The mean postoperative stay was 36 hours and mortality was zero. We conclude that SCM is highly specific for the evaluation of mediastinal node involvement in bronchogenic carcinoma and it is the approach of choice when a diagnosis of lesions located in the mid-mediastinal region has not been reached. ECM is a valid, safe alternative to anterior mediastinotomy for staging nodes and masses occupying para-aortic zones or the aortopulmonary window, with good diagnostic yield, low morbidity and absence of mortality.

Adenocarcinoma↗
PubMed2003

Defective regulation of the protective IgE response against intestinal helminth Ascaris lumbricoides in malnourished children.

It is well established that malnutrition affects the immune response and increases the susceptibility to parasitic infection. In the present study we evaluated some aspects of the cellular and cytokine network that regulate the IgE responses, which are important components of host defence mechanisms against helminthic parasites in children infected with the intestinal helminth Ascaris lumbricoides, and with differing degrees of malnutrition. We found a defective T cell response in malnourished children, as indicated by diminished levels of circulating total (CD3+), helper (CD4+), IL-2-receptor-bearing (CD4+CD25+) and memory helper T cell responses (CD4+CD45RO+) in keeping with the decreased specific IgE levels against Ascaris lumbricoides. In contrast, the proportions of total B cells (CD20+), and those bearing the low-affinity IgE receptor (CD23+) were increased in the moderated malnourished children. Moreover, serum IL-4 levels and total IgE were also increased in these children. We suggest that malnutrition can cause an imbalance in T cell subpopulations that may lead to a defective T cell maturation and a decreased specific anti-Ascaris IgE response thus increasing the susceptibility to such infections. The high levels of total IgE observed may be related to a non-specific stimulation of the proliferation of activated B cells, probably caused by helminthic parasites and other infectious agents that are frequent in malnourished children.

Analysis of Variance↗
PubMed2002

Antiviral susceptibility of Herpes simplex viruses and its clinical correlates: a single center's experience.

The in vitro susceptibility to acyclovir of 204 herpes simplex virus isolates from 165 immunocompromised patients treated at our hospital was determined by the cytopathic effect reduction assay. Approximately 95% of herpes simplex virus 1 and 73% of herpes simplex virus 2 isolates were inhibited by acyclovir at concentrations of <2 microgram/mL. From 8 patients (5%), an isolate with low susceptibility to acyclovir (50% inhibitory dose, >3 microgram/mL) was recovered. Medical records of 83 patients were reviewed. Lesions resolved in most of the patients, independent of treatment. Treatment failures were not always associated with isolation of an in vitro-resistant virus. On the contrary, when a virus with low susceptibility to acyclovir was isolated, resolution of the lesion was the rule. In 9 of 10 patients with subsequent recurrent episodes of disease, the susceptibility of the viruses isolated was similar to that of the first episode. Routine susceptibility testing in our geographic area is not encouraged because of the low incidence of acyclovir-resistant herpes simplex viruses.

Acyclovir↗
PubMed2002

[Quality of life, psychological and social aspects in patients with advanced HIV disease].

OBJECTIVE: The advanced HIV infection carries an important physical, psychological and quality of life deterioration for patients. The introduction of new treatment strategies probably implies a global benefit for HIV patients. We carried out this study in order to know in HIV advanced patients; the clinical situation, the prevalence of psychological alterations (anxiety and depression), the quality of life and the impact of the introduction of new antiretroviral drugs about these variables. METHODS: This is a prospective observational study carried out between January of 1996 and June of 1997 with 52 advanced HIV patients (CD4 cells less than 200/microliter). We carried out 2 clinical interviews with an interval of 12 months being introduced after the first one a change of strategy of antiretroviral treatment. For evaluating the quality of life, the MOS SF-36 was used. The valuation of the anxiety and depression were carried out with the instruments STAI and Beck respectively. RESULTS: An important physical deterioration was found at the beginning of the study with 84.6% of polisymptomatic patients. We found a high prevalence of anxiety (76.9%) and depression (86.6%) that reaches criteria of graveness respectively in 75% and 25% of the cases. The quality of life was severely affected involving most of the dimensions of the SF-36 scale preserving the social function. The introduction of the change of therapeutic strategy produces a reduction of polisymptomtics patients to 54.8% (p = 0.05), of the graveness of the anxiety (p = 0.009) and depression (p = 0.05) and improving in the perception of general health (p = 0.03) and alterations of physical role (p = 0.02). CONCLUSIONS: The advanced HIV infection carries a high symptomatic load with a high prevalence of psychological dysfunctions and deterioration of the quality of life. The new strategies of HIV treatment induce a global improvement to the patients, but it makes necessary a better management of the psychological dysfunctions.

Adaptation, Psychological↗
PubMed2001

Differences in the effects of flooding the soil early and late in the photoperiod on the water relations of pot-grown tomato plants.

The water relations of potted tomato plants (Lycopersicon esculentum Mill. cv INCA 9(1)) submitted to two flooding/recovery cycles imposed at the beginning and at the end of photoperiod were studied under controlled conditions. In both experiments, flooding induced stomatal closure due to leaf dehydration linked to a lowered root hydraulic permeability. Thus, during the early hours of flooding there was an effective negative hydraulic message from O(2) deficient roots. However, when the soil was drained stomata did not re-open until some time after leaf water potential and leaf turgor potential returned to normal, supporting the view that chemical messages predominate. Flooding imposed at the end of photoperiod induced a delay in g(l), Psi(l), and Psi(p,) recovery.

Journal Article↗