Biomedical subjects

E Sánchez

Publications and source records attributed to E Sánchez.

At least 19 recordsLinked to original sources

PubMed2006

Biodegradable implantable fluconazole delivery rods designed for the treatment of fungal osteomyelitis: influence of gamma sterilization.

Fluconazole poly(D,L-lactic) acid (PLA) and poly(L-lactic) acid (L-PLA) implantable delivery rods were studied, in vitro and in vivo, as an alternative treatment of fungal osteomyelitis. Implantable rods loaded with 5% fluconazole (FLU) were prepared by the injection-molding method and sterilized by gamma-irradiation at a dose of 25 kGy. Loading efficiency, physical chemistry (high performance liquid chromatography, X-ray diffraction, gel permeation chromatography), and in vitro and in vivo release assays were performed to evaluate the novel delivery systems and the sterilization effect on implant characteristics. In spite of polymer degradation after gamma-irradiation, the loading efficiency, chemical stability, and crystallographic structure of FLU were not affected. In vivo studies were carried out in femoral bone marrow of rabbits. Approximately 85 and 80% of the total dose were released within 12 and 4 weeks from PLA and L-PLA rods, respectively. This showed a faster release rate of FLU in vivo than in vitro, showing almost zero-order kinetics from PLA rods.

Animals↗

PubMed2006

Evidence of association of macrophage migration inhibitory factor gene polymorphisms with systemic lupus erythematosus.

The aim of this study was to evaluate the potential association of functional polymorphisms of macrophage migration inhibitory factor with systemic lupus erythematosus. Our study includes 711 systemic lupus erythematosus (SLE) patients and 755 healthy controls. We genotyped the migration inhibitory factor (MIF) -173G/C using a polymerase chain reaction (PCR) system with predeveloped TaqMan allelic discrimination assay and the MIF -794 CATT(n) microsatellite polymorphism using a PCR-fluorescent method. A statistically significant difference in the distribution of the MIF -173(*)C allele between SLE patients and controls (P=0.004, OR=1.34, 95% CI=1.05-1.27) was observed. In addition, the frequency of the MIF -173(*)C/C genotype was higher in SLE patient (P=0.002, OR=2.58, 95% CI=1.32-5.10). No differences in the distribution of CATT(n) were found. However, the haplotypes analyses showed that only the CATT(7)-MIF -173(*)C haplotype was associated with a higher susceptibility to SLE (P=0.001, OR 1.84, 95% CI 1.35-2.79). No association with clinical features was detected in any case. These results suggest that both, MIF -173(*)C allele and CATT(7)-MIF -173(*)C haplotype, confer susceptibility to SLE in our population.

Adult↗

PubMed2006

Spontaneous bursting and rhythmic activity in the cuneate nucleus of anaesthetized rats.

Spontaneous and rhythmic neuronal activity in dorsal column nuclei has long been identified in anesthetized cats. Here, we have studied the spontaneous behavior of cuneate cells in anesthetized rats through extracellular recording, showing that most cuneate neurones recorded (155 of 185) fired spontaneously. Overall, 74% of these spontaneously firing neurones were single-spiking and 26% were bursting. Cells were considered "bursting" when more than 50% of the spontaneous spikes belonged to bursts. Nevertheless, occasional bursts were seen in 33% of spontaneous cuneate cells which were classified as single-spiking. Rhythmic firing was observed in about 14% of both spontaneously bursting and single-spiking cells, and these cells were located close to the obex (+/-0.5 mm). Although the spike-frequency was mostly in the range 0-15 spikes/s, spontaneous rhythmic activity was circumscribed mainly to the alpha/beta-like range, both in single-spiking (26.1+/-3.6 Hz, n=16) and bursting cells (19.5+/-4.1 Hz, n=6). Lemniscal stimulation often activated several antidromic units with the same latency. About 65% of cuneolemniscal cells were spontaneously active and of these, 83% were single-spiking and 11% rhythmic (all single-spiking). In cells that were not antidromically activated from the medial lemniscus, short latency orthodromic responses consistent with excitation by recurrent lemniscal collaterals were often observed following lemniscal activation. Interestingly, only cells completely unresponsive to lemniscal stimulation showed rhythmic bursting. Most spontaneous cells responded with a burst to natural receptive field stimulation, while rhythmic cells became temporally arrhythmic. These results demonstrate, for the first time, that rat cuneate neurones can fire bursts spontaneously. Besides, this bursting activity can be rhythmic. These two properties, and the fact that groups of cuneolemniscal cells share the same conduction velocity, probably imply the reinforcement of temporal and spatial summation at their targets when they are synchronously recruited by the stimulation of overlapping receptive fields.

Action Potentials↗

PubMed2006

Role of turbulence on edge momentum redistribution in the TJ-II stellarator.

Radial profiles of the parallel-radial Reynolds stress component, proportional to the cross correlation between parallel and radial fluctuating velocities, have been measured in the plasma boundary region of the TJ-II stellarator. Experimental results show the existence of significant parallel turbulent forces at plasma densities above the threshold value to trigger perpendicular sheared flows. This finding provides the first experimental evidence of the role of parallel turbulence forces on edge momentum redistribution in fusion devices.

Journal Article↗

PubMed2006

Evaluation of municipal wastewater treatment plants with different technologies at Las Rozas, Madrid (Spain).

Eight small-scale municipal wastewater treatment plants were evaluated over a period of 19 months in the suburb of Las Rozas in Madrid (Spain). Four plants used compact extended aeration, two used conventional activated sludge, two used conventional extended aeration, one used a rotary biodisc reactor and the other used a peat bed reactor. The best results were obtained from the plants that used conventional technologies and the biodisc. Conventional activated sludge and extended aeration had higher removal efficiencies for ammonia, TSS, COD and BOD(5) and produced good quality final effluents for final disposal in accordance with the discharge standard. Empirical equations that correlated the concentration of dissolved oxygen in the effluents with the efficiencies of TSS, ammonia, COD and BOD(5) removals for all plants evaluated were obtained. The performance of the plants using compact extended aeration was affected more than those using conventional technologies or rotary biodisc when the capacity exceeded that of its initial design.

Evaluation Studies as Topic↗

PubMed2006

No primary association of MICA polymorphism with systemic lupus erythematosus.

OBJECTIVE: To replicate the described association between MHC class I chain-related A (MICA) gene polymorphism and susceptibility to systemic lupus erythematosus (SLE). METHODS: MICA transmembrane microsatellite polymorphism was genotyped using a polymerase chain reaction (PCR)-based method. Genotyping of HLA-B* and DRB1* was performed using PCR and detection with a reverse sequence-specific oligonucleotide (SSO) probe system. Combined data for these three loci (HLA-B*, DRB1* and MICA) were obtained from a total of 333 patients and 361 healthy controls. RESULTS: Significant association with B*08 [P < 10(-7), odds ratio (OR) 3.17, 95% confidence interval (CI) 2.02-5.00], DRB1*0301 (P < 10(-7), OR 2.07, 95% CI 1.59-2.68) and MICA5.1 (P = 0.01, OR 1.23, 95% CI 1.04-1.46) was observed. The combinations DRB1*0301-MICA5.1-B8 and HLA-DRB1*0301-B*08-positive and MICA5-1-negative were more frequent among SLE patients (11.4 vs 3.3% in healthy controls, P = 3.9 x 10(-5), OR 3.76, 95% CI 1.85-7.73, and 6.9 vs 1.7%, P = 0.0007, OR 4.32, 95% CI 1.68-13.10, respectively). Additionally, individuals who were HLA-DRB1*0301-B*08-negative and MICA5-1-positive were less frequent among patients (22.2 vs 31.3% in healthy controls, P = 0.007, OR 0.63, 95% CI 0.44-0.89) and the magnitude of the OR was similar to that obtained in individuals negative for all the three factors (OR 0.69, 95% CI 050-0.94). Further analysis performed to detect independent association strongly suggested that the association between MICA5.1 and SLE is secondary to the linkage disequilibrium of this allele with B*08. CONCLUSIONS: Our results do not support an independent association of MICA gene polymorphism with susceptibility to SLE.

Adolescent↗

PubMed2006

Epistatic interaction between FCRL3 and NFkappaB1 genes in Spanish patients with rheumatoid arthritis.

BACKGROUND: A Japanese study has described a strong association between rheumatoid arthritis and several polymorphisms located in the Fc receptor-like 3 (FCRL3) gene, a member of a family of genes related to Fc receptors located on chromosome 1q21-23. OBJECTIVES: To evaluate the association between rheumatoid arthritis and FCLR3 polymorphisms in a large cohort of Caucasian patients with rheumatoid arthritis and healthy controls of Spanish origin. Owing to the described functional link between the FCRL3 polymorphisms and the transcription factor nuclear factor kappaB (NFkappaB), a functional polymorphism located in the NFkappaB1 gene was included. METHODS: 734 patients with rheumatoid arthritis from Madrid and Granada, Spain, were included in the study, along with 736 healthy controls. Polymorphisms in the FCRL3 gene were studied by TaqMan technology. The -94ins/delATTG NFkappaB1 promoter polymorphism was analysed by fragment analysis after polymerase chain reaction with labelled primers. Genotypes were compared using 3x2 contingency tables and chi2 values. RESULTS: No overall differences were found in any of the FCRL3 polymorphisms and in the NFkappaB1 promoter polymorphism when patients were compared with controls. However, when stratified according to NFkappaB1 genotypes, a susceptibility effect of FCRL3 polymorphisms was observed in patients who were heterozygotes for NFkappaB1 (pc = 0.003). CONCLUSIONS: The FCRL3 polymorphisms associated with rheumatoid arthritis in a Japanese population are not associated per se with rheumatoid arthritis in a Spanish population. A genetic interaction was found between NFkappaB1 and FCRL3 in Spanish patients with rheumatoid arthritis. These findings may provide a general rationale for divergent genetic association results in different populations.

Adult↗

PubMed2006

Attitudes of primary care professionals in Spain toward xenotransplantation.

OBJECTIVE: The deficit in transplantable organs is making it necessary to find alternative sources. One possibility is xenotransplantation. However, the use of animal organs may be rejected by society and among health professionals. Primary Care is fundamental for promoting matters of health; in Spain it has access to nearly 100% of the population. Our objective was to analyze the acceptance of this therapy, although it is experimental, among Primary Care professionals, given that they are the ones most involved in spreading information about this therapy if it was confirmed to be useful. MATERIALS AND METHODS: A random sample was stratified by sex, job category, and geographical location among Primary Care personnel, including 428 professionals in 32 health centers among population of 2851 professionals. Attitudes toward xenotransplantation were evaluated using a questionnaire on psychosocial attitudes validated in our geographical area. Contact was made in each center with the Doctor Coordinator for doctors, the Nursing Coordinator for nurses, and an Administrative Officer for ancillary personnel. The chi-square test and Student t test were applied to evaluate categorical and continuous data, respectively. RESULTS: Attitudes toward xenotransplantation were similar to those obtained in human organs: favorable in 79% (n = 325), whereas 19% (n = 78) had doubts and 2% (n = 10) were against. The attitude was more favorable in men (89% vs 72%; P < .000), those who had cared for transplant patients (84% vs 71%; P = .009), those with previous experience in organ donation and transplantation (84% vs 75%; P = .033), those with an attitude in favor of cadaveric organ donation (83% vs 66%; P < .0001), and those in favor of living donation of the kidney (P < .000) or the liver (P < .000), as well as those who believed that they may need a transplant at some time in the future (84% vs 74%; P = .045). There was a clear difference in attitude according to job category (P = .018): approval rates were 89% for doctors, 76% for nurses, and 70% for ancillary personnel. CONCLUSIONS: Attitudes toward future application of xenotransplantation were quite positive among doctors. However, the attitudes of nursing and ancillary personnel were similar to those of the general population. The main factors related to such an attitude depended mainly on the previous relationship and attitude of the respondent toward human organ donation and transplantation.

Animals↗

PubMed2006

Primary care doctors faced with living organ donation.

OBJECTIVE: The attitudes of health care personnel, specifically doctors, have a significant influence on public attitudes toward organ donation and transplantation. The objective herein was to analyze the attitudes of Primary Care (PC) doctors toward living organ donation and to determine the psychosocial factors that condition these attitudes. MATERIALS AND METHODS: A random sample was stratified by geographical location (six health areas in our community) among PC doctors, including 155 respondents from 32 health centers. Attitudes toward donation were evaluated using a psychosocial questionnaire validated in our geographical area. Contact was made with the Doctor Coordinator in each center for distribution of the questionnaires, which were completed anonymously. The chi-square test and Student t test were applied to evaluate the data. RESULTS: When the living donor is not related, only 21% (n = 32) of PC doctors were in favor of living kidney donation, and only 20% (n = 31) for living liver donation (P > .05). In contrast, these percentages were 90% and 89% in favor of kidney and liver related donation, respectively. Upon analysis of the psychosocial variables affecting these attitudes, there was only an association with their partner's opinion (P = .009 for kidney and P = .000 for liver), and the possibility of needing a transplant oneself (P = .000). CONCLUSIONS: PC doctors have favorable attitudes toward related living donation. If living donation is promoted by transplant coordination units, such PC professionals could act as a source of positive information about the matter for the general public.

Attitude of Health Personnel↗

PubMed2006

Multislice CT in graft vascular disease. A pilot study.

INTRODUCTION: Graft vessel disease (GVD) is one of the main long-term complications in heart transplant (HT) patients. At present, the diagnosis of this complication requires invasive procedures. Multislice CT is an emerging technique that allows visualization of the coronary anatomy, including the vascular lumen and wall thickness. Our objective was to establish the value of 16-detector multislice CT in the detection of GVD, compared with angiography and intravascular ultrasound (IVUS). PATIENTS AND METHODS: We studied 32 HT patients, who had a mean follow-up of 2016 days. CT was performed 24 hours prior to angiography, associated with IVUS if the latter proved normal. Comparisons were subsequently made using contingency tables to establish the sensitivity, specificity, and predictive values of the CT. RESULTS: Angiography was not performed on two patients, and eight were excluded from CT assessment due to serum creatinine values >1.5 mg/dL. Comparison of the CT findings with the invasive techniques yielded a sensitivity of 50%, a specificity of 81%, a negative predictive value of 81%, a positive predictive value of 50%, and a precision of 72%. CONCLUSIONS: Our results suggested good performance of the technique in screening for GVD because a high negative predictive value was recorded. We plan to increase the number of patients and use the 64-detector CT system to ensure greater time and spatial resolution.

Follow-Up Studies↗

PubMed2006

Information requested about organ donation in primary health care centers.

UNLABELLED: Information provided by primary care workers about organ donation significantly affects the attitude of the general public. The objective of this study was to evaluate information about donation requested by the general public in health centers in an autonomous community (region) of Spain and to find out how many workers provided relevant information. MATERIALS AND METHODS: A random sample was taken and stratified by sex, job category, and geographical location (six health areas of our autonomous regional community, 45 municipal councils), among primary care health workers in order to obtain a total of 428 respondents in 34 primary care centers. A study was undertaken of information requested and provided about organ donation and transplantation. The chi square test was applied and differences were considered significant at levels of P < .05. RESULTS: Forty-three percent (n=185) of the workers surveyed indicated that information had been requested from them about organ donation and transplantation. This request for information was much greater from physicians than from the other types of workers (P = .015). Furthermore, 54% of primary care health workers (n=229) reported having provided information about donation, especially physicians (64%), with this being mainly favorable. Information had also been provided by nurses (59%) and ancillary staff (34%). CONCLUSION: Information requested from primary care health workers by the general public about organ donation and transplantation is increasing when we compare it to data from previous years. Around half of primary care workers have offered information about transplantation. Therefore, it is fundamental that these workers have adequate and correct information to provide patients and families.

Attitude to Death↗

PubMed2006

Is there a correlation between brain naturietic peptide levels and echocardiographic and hemodynamic parameters in heart transplant patients?

BACKGROUND: Brain naturietic peptide (BNP) elevations have been reported in heart transplant patients both at baseline and during rejection. An association between BNP levels and certain echocardiographic and hemodynamic abnormalities has also been found in nontransplanted heart disease patients. We sought to determine whether BNP values were correlated with echocardiographic and hemodynamic parameters among a large cohort of heart transplant patients. MATERIALS AND METHODS: We studied 71 consecutive heart transplant patients, excluding combined grafts, retransplants, and pediatric cases. We performed 488 BNP determinations during catheterization and within 48 hours of echocardiography. Hemodynamic parameters included mean pulmonary artery pressure, right ventricular systolic and diastolic pressures. Doppler echocardiography parameters were wall thickness, ventricular mass, left and right ventricular end-diastolic and end-systolic diameters, isovolumic relaxation time, and mitral flow deceleration time. RESULTS: We observed significant correlations between BNP values and left ventricular size, ventricular mass, and a restrictive filling pattern. BNP levels were also significantly correlated with right ventricular size, mean pulmonary artery pressure, and right ventricular diastolic and end-diastolic pressures. CONCLUSIONS: In heart transplant patients, BNP levels positively correlated with ventricular diameters and a restrictive filling pattern. An increase in right ventricle and pulmonary artery pressures was associated with elevated BNP values.

Biomarkers↗

PubMed2006

Computed tomography perfusion usefulness in early imaging diagnosis of herpes simplex virus encephalitis.

An early diagnosis is crucial in herpes simplex virus encephalitis patients in order to institute acyclovir therapy and reduce mortality rates. Magnetic resonance imaging (MRI) is considered the gold standard for evaluation of these patients, but is frequently not available in the emergency setting. We report the first case of a computed tomography (CT) perfusion study that helped to establish a prompt diagnosis revealing abnormal increase of blood flow in the affected temporoparietal cortex at an early stage.

Encephalitis, Herpes Simplex↗

PubMed2006

An evaluation of variables affecting the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater.

The influence of the most important variables on the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater after primary sedimentation was evaluated at HRT in the range of 1-6 d and influent substrate concentration in the range of 2 to 12 g TCOD l(-1). The effect of HRT was more pronounced compared to that of influent strength. An increase in the HRT increased the process stability and process performance at different influent strengths. TCOD, SCOD, BOD5 TSS, organic nitrogen (N) and Orthophosphate (P) removals increased with the HRT, independently of the initial substrate concentration (S0). The increase in S0 brought about an increase in the attached biomass concentration (X) at the end of the experiment. Two empirical models based on the individual effect of HRT, X and S0 were evaluated and found to be adequate to describe the influence of these variables on the process performance. The first model took all the above-mentioned variables into consideration while the second model was simplified and based on the use of HRT as the only independent variable. The results obtained by using both models were found to be similar. This demonstrated that independently of the characteristics of the operation, the behaviour and performance of the reactors were comparable. The methane yield coefficient was found to be 0.3371 methane g(-1) TCOD removed.

Anaerobiosis↗

PubMed2006

Production of biomass (algae-bacteria) by using a mixture of settled swine and sewage as substrate.

This paper presents the use of a mixture of settled swine and sewage as substrate for biomass production, mainly constituted by microalgae Chlorella vulgaris and aerobic bacteria, growing outdoor at different dilution rates in a continuous mode. The experiments were carried out in 16-litre volume laboratory ponds operating at hydraulic retention times (HRT) in a range of 4-14 days equivalent to dilution rates (D) in a range of 0.250-0.071 d(-1). Total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), total biochemical oxygen demand (TBOD(5)), total suspended solids (TSS), volatile suspended solids (VSS), total Chlorophyll (S C), total Kjeldahl nitrogen (TKN), ammonia nitrogen, total phosphorous, orthophosphate and pH were monitored. An empirical relationship between the dilution rate (D) and the removal efficiencies of TCOD, SCOD, TBOD(5), TKN and total phosphorous was found. The occurrence of an inhibition process for TCOD, TBOD(5), TKN and total phosphorous removals was observed. The Andrews kinetic model was successfully applied to these experimental data, while the Monod model was more suitable for studying the variation of the SCOD removal rate with the effluent SCOD concentration. The maximum microalgal biomass productivity was found to be in the range of 93-98 mg VSS(A)/L d (37.2-39.2 g/m(2)d) at dilution rates in the range of 0.167-0.250 d(-1), where VSS(A) is the concentration of microalgae expressed in VSS. In the case of the bacteria, the productivity increased linearly with the dilution rate being maximum at a D value of 0.25 d(-1). It was concluded that the mixture of pre-treated swine and sewage used as substrate, contributed to the obtention of a high biomass (microalgae-bacteria) production, providing a simple technology feasible to be applied in developing countries.

Animals↗

PubMed2006

Study of a functional polymorphism in the p53 gene in systemic lupus erythematosus: lack of replication in a Spanish population.

The aim of this study was to assess the possible association between the p53 suppressor gene codon 72 polymorphism and systemic lupus erythematosus (SLE). Our study population consisted of 513 SLE patients and 567 healthy controls. All the individuals were of Spanish Caucasian origin. Genotyping of the p53 codon 72 polymorphism was performed by allele-specific PCR. No statistically significant differences were observed between SLE patients and healthy controls when p53 codon 72 genotype and allele frequencies were compared. In addition, no evidence for association with clinical subfeatures of SLE was found. In conclusion, the p53 codon 72 polymorphism associated with SLE in a Korean population does not appear to play a major role in the susceptibility or severity of SLE in the Spanish population.

Adult↗

PubMed2005

Study of the role of functional variants of SLC22A4, RUNX1 and SUMO4 in systemic lupus erythematosus.

BACKGROUND: Functional polymorphisms of the solute carrier family 22, member 4 (SLC22A4), runt related transcription factor 1 (RUNX1) and small ubiquitin-like modifier 4 (SUMO4) genes have been shown to be associated with several autoimmune diseases. OBJECTIVE: To test the possible role of these variants in susceptibility to or severity of systemic lupus erythematosus (SLE), on the basis that common genetic bases are shared by autoimmune disorders. METHODS: 597 SLE patients and 987 healthy controls of white Spanish origin were studied. Two additional cohorts of 228 SLE patients from Sweden and 122 SLE patients from Colombia were included. A case-control association study was carried out with six single nucleotide polymorphisms (SNP) spanning the SLC22A4 gene, one SNP in RUNX1 gene, and one additional SNP in SUM04 gene. RESULTS: No significant differences were observed between SLE patients and healthy controls when comparing the distribution of the genotypes or alleles of any of the SLC22A4, RUNX1, or SUMO4 polymorphisms tested. Significant differences were found in the distribution of the SUMO4 genotypes and alleles among SLE patients with and without nephritis, but after multiple testing correction, the significance of the association was lost. The association of SUMO4 with nephritis could not be verified in two independent SLE cohorts from Sweden and Colombia. CONCLUSIONS: These results suggest that the SLC22A4, RUNX1, and SUMO4 polymorphisms analysed do not play a role in the susceptibility to or severity of SLE.

Adult↗

PubMed2005

A model with 'growth retardation' for the kinetic heterogeneity of tumour cell populations.

In the present paper we propose a continuous cell population model based on Shackney's idea of growth retardation. Cells are characterized by two state variables: the cell maturity x, 0 < or = x < or = 1, and a state variable T that identifies the rate of maturation along cell cycle. During their life span, cells can change T at random by jump transitions to T values corresponding to slower maturation rates, while at each jump the maturity x is conserved. Both the time evolution of the population and the exponential stationary solution are numerically computed. The distribution of the cell cycle transit time in asynchronous exponential growth is investigated by Monte Carlo simulation. An approximated formula for the distribution of cell cycle time is also provided.

Algorithms↗