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Biomedical subjects

M Aguilar

Publications and source records attributed to M Aguilar.

At least 19 recordsLinked to original sources
PubMed2006

Removal of cadmium from aqueous solutions by adsorption onto orange waste.

The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated. The material was characterized by Fourier transform infrared spectroscopy and batch experiments were conducted to determine the adsorption capacity of the biomass. A strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose. Kinetics and adsorption equilibrium were studied at different pH values (4-6). The adsorption process was quick and the equilibrium was attained within 3h. The maximum adsorption capacity of orange waste was found to be 0.40, 0.41 and 0.43 mmol/g at pH 4-6, respectively. The kinetic data were analysed using various kinetic models - pseudo-first order equation, pseudo-second order equation, Elovich equation and intraparticle diffusion equation - and the equilibrium data were tested using four isotherm models - Langmuir, Freundlich, Sips and Redlich-Peterson. The data were fitted by non-linear regression and five error analysis methods were used to evaluate the goodness of the fit. The Elovich equation provides the greatest accuracy for the kinetic data and the Sips model the closest fit for the equilibrium data.

Adsorption↗
PubMed2006

NARP-MILS syndrome caused by 8993 T>G mitochondrial DNA mutation: a clinical, genetic and neuropathological study.

The 8993 T>G mutation in mitochondrial DNA has been associated with variable syndromes of differing severity ranging from maternally inherited Leigh's syndrome (MILS) to neuropathy, ataxia, retinitis pigmentosa (NARP), depending on the mutation loads in affected patients. We report a kindred with several members in the same generation suffering NARP or Leigh's syndrome due to a 8993 T>G mutation. Post-mortem studies of the brain in one affected member clinically presenting with a neurological disorder intermediate between adult Leigh's syndrome and NARP showed symmetrical lesions of the basal ganglia and brainstem closely resembling those usually described in typical Leigh's syndrome. Analysis of mtDNA in different tissues showed a high proportion of mutant genome in brainstem, cerebral cortex, putamen, cerebellum and thalamus. These observations illustrate the continuum of clinical and neuropathological manifestations associated with the 8993 T>G mutation of the mtDNA.

Adenosine Triphosphatases↗
PubMed2005

Influence of synthesis methods on tungsten dispersion, structural deformation, and surface acidity in binary WO3-ZrO2 system.

WO3-ZrO2 catalysts were synthesized by precipitating the aqueous solutions of zirconium oxynitrate and ammonium metatungstate with ammonium hydroxide. The white slurry precipitate was treated under three different conditions. In the as-made materials, the amorphous phase was formed in the aged and refluxed samples, while well-crystallized tetragonal and monoclinic phases were obtained in the hydrothermally treated sample. The real amount of tungsten loaded in the samples was similar for the three samples, independently of the treatments; however, the tungsten surface atomic density in the annealed WO3-ZrO2 samples varied between 6 and 9 W atoms/nm2. Two different contrast types of aggregates were determined by scanning electron microscopy, the white particles which are rich in W, and the gray ones which are rich in zirconium; both of them were formed in the calcined solids prepared under aging or reflux condition. A very high dispersion of tungsten species on the zirconia surface was achieved in the hydrothermally treated sample. The degree of the interaction between WO(x) and ZrO2 surface strongly modified the Zr-O bond lengths and bond angles in the structure of tetragonal zirconia as proved by X-ray diffraction analysis and the Rietveld refinement. The catalyst obtained under hydrothermal condition exhibited the highest dispersion of tungsten species in the zirconia, which in turn causes strong structural deformation of the tetragonal ZrO2 phase responsible of the strongest surface acidity and, consequently, the optimum catalytic activity for n-hexane isomerization.

Journal Article↗
PubMed2005

Antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks.

BACKGROUND: Non-valvular atrial fibrillation (AF) carries an increased risk of stroke. Antiplatelet therapy (APT) is proven effective for stroke prevention in most patients at high-risk for vascular events, but its value for primary stroke prevention in patients with non-valvular AF merits separate consideration because of the suspected cardioembolic mechanism of most strokes in AF patients. OBJECTIVES: To assess the efficacy and safety of long-term APT for primary prevention of stroke in patients with chronic non-valvular AF. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (searched August 2004). In addition, we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to June 2004), and the reference lists of recent review articles. We also contacted experts working in the field to identify unpublished and ongoing trials. SELECTION CRITERIA: Randomized trials comparing long-term APT with placebo or control in patients with non-valvular AF and no history of transient ischemic attack (TIA) or stroke. A sensitivity analysis included one additional randomized trial involving primary prevention with aspirin plus very low dose warfarin. DATA COLLECTION AND ANALYSIS: Two authors independently selected trials for inclusion and extracted data for each outcome. Unpublished data were obtained from trial investigators. MAIN RESULTS: Three trials tested aspirin in dosages ranging from 75 mg to 325 mg per day and 125 mg every other day to placebo (in two trials) or control (in one trial) in 1965 AF patients without prior stroke or TIA. The mean duration of follow up averaged 1.3 years per participant. Aspirin was associated with non-significant lower risks of all stroke (odds ratio (OR) 0.70, 95% confidence interval (CI) 0.47 to 1.07), ischemic stroke (OR 0.70, 95% CI 0.46 to 1.07), all disabling or fatal stroke (OR 0.86, 95% CI 0.50 to 1.49) and all-cause death (OR 0.75, 95% CI 0.54 to 1.04). The combination of stroke, myocardial infarction or vascular death was significantly reduced (OR 0.71, 95% CI 0.51 to 0.97 ). No increase in intracranial hemorrhage or major extracranial hemorrhage was observed. AUTHORS' CONCLUSIONS: Aspirin appears to reduce stroke and major vascular events in patients with non-valvular AF similar to its effect in other high-risk patients (ie by about 25%). For primary prevention among AF patients with an average stroke rate of 4% per year, about 10 strokes would likely be prevented yearly for every 1000 AF patients given aspirin.

Aspirin↗
PubMed2005

Multiple pulmonary neoplasia positive for thyroglobulin.

We present, for the first time, a case of carcinoid metastatic pulmonary tumor positive for thyroglobulin. A 73-yr-old woman diagnosed with metastases of probable thyroid carcinoma, manifested by a mediastinic mass and multiple pulmonary nodules positive for radioiodine (I131). Histological analysis showed typical findings of carcinoid tumor with positive immunohistochemistry for neuron-specific enolase, synaptophysin and thyroglobulin, and negative for chromogranin and calcitonin. We underline the exceptional finding of positive reaction for thyroglobulin, and discuss difficulties in differential diagnosis between metastatic differentiated thyroid and carcinoid neoplasms.

Aged↗
PubMed2005

[Diagnostic value and test-retest reliability of the Blessed Dementia Rating Scale for Alzheimer's disease: data from the NORMACODEM project].

INTRODUCTION: This study aims to discover the criterion validity of the Blessed Dementia Rating Scale (BDRS) for the diagnosis of Alzheimer's disease. Different cut-off scores and corresponding diagnostic sensitivities and specificities were established. Test-retest reliability and internal consistency of the BDRS were also analyzed. METHODS SAMPLE: 451 subjects were studied (254 controls, 86 subjects with mild cognitive impairment and 111 patients with Alzheimer's disease). INSTRUMENTS: scores from different sections of the Blessed score were obtained. The global score (BBRS-Total) is the result of the sum of the three sections, A (changes in every day activities), B (changes in habits) and C (changes in personality). The sum of parts A and B (BDRS-Mod) were also quantified. STATISTICS: ROC curves, intraclass correlation coefficient and Cronbach's alpha. RESULTS: The best cut-off score for the BDRS-Total was 3.5 (sensitivity: 87.39%, and specificity: 90%). For the BDRS-Mod, the best cut-off score was 1.5 (sensitivity: 90%, and specificity: 89%). Area under the ROC curve was 0.964 and 0.963 respectively. Intraclass correlation coefficient was 0.98 and Cronbach's alpha was 0.925. CONCLUSIONS: The BDRS has good discriminative validity in terms of sensitivity, specificity and predictive value. It also has good test-retest reliability and internal consistency.

Adult↗
PubMed2004

Vigabatrin-induced modification of Ki-67 expression in gingival epithelium: immunohistochemical study of a short series.

OBJECTIVE: To study the expression and role in vigabatrin (VGB)-induced gingival enlargement of Ki-67 antigen and p27KIP1, p21WAF1, and p53, proteins that activate or inhibit cell-cycle progression. MATERIALS AND METHODS: Six patients treated with VGB for partial epileptic seizures refractory to classic anticonvulsant treatment were studied. Gingival biopsies were taken from four of these patients for immunohistochemical studies; 10 control biopsies from individuals with healthy gingiva and 10 from patients with periodontal disease were also evaluated. RESULTS: Four of the six patients presented some degree of gingival enlargement (mild or moderate). Nuclear expression of Ki-67 was elevated (mean of 894 positive cells/mm2 in VGB-induced gingival enlargement vs. 391 cells/mm2 in controls with healthy gingiva and 425 cells/mm2 in controls with periodontal disease) (p < 0.01, analysis of variance: anova), and nuclear expression of cyclin-dependent kinase (cdk) inhibitors p27KIP1 and p21WAF1 was reduced. The patients with gingival enlargement presented inflammatory infiltrate in lamina propria, mainly composed of T lymphocytes (CD3+) and plasma cells (CD38+), which was even more intense than in the biopsies of patients with periodontal disease. CONCLUSION: The overexpression of antigen Ki-67 and slight underexpression of cdk-inhibitors p27KIP1 and p21WAF1 suggest that VGB induced an increase in cell proliferation and contributed, together with concomitant periodontal disease, to the gingival enlargement.

Adolescent↗
PubMed2004

[Freezing of gait or freezing of quadruped gait].

Parkinson's disease (PD) is frequently associated with freezing of gait. Patients with advanced PD learn to use tricks to relieve freezing of gait. Recently one of our patients informed us that he could overcome freezing of gait by crawling. Since crawling is a sort of quadruped gait that humans develop transiently, we wondered whether quadruped gait is preserved in PD. We recruited 16 patients with PD who had frequent and disabling freezing of gait. Under experimental conditions, after 12 hours without medication, seven patients developed biped freezing of gait. Of these seven patients, only two patients (the patients with the most severe freezing) also developed quadruped freezing of gait. This experiment suggests that bipedal gait is affected early in PD, while quadruped gait is preserved until late in this disease.

Aged↗
PubMed2003

Depression in Parkinson's disease: clinical correlates and outcome.

Depression has been shown to be more common in Parkinson's disease (PD) than in other chronic and disabling disorders. Neurochemical and functional disturbances are important etiopathogenic factors. The prevalence and clinical features associated with depression in PD remain controversial. The purpose of this study is to estimate the prevalence of depressive symptoms in our patients, as related to other clinical data, and to assess clinical outcomes of these symptoms. A series of PD patients were evaluated over a 9-year period, using the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn and Yahr stage (HY), Schwab and England Scale (SE), Mini-Mental State Examination (MMSE), and Yesavage Geriatric Depression Scale (GDS). Presence of depressive symptoms was considered if GDS score was higher than 10: mild-moderate (MD) for GDS scores between 11 and 20 and moderate-severe (SD) for GDS scores greater than 20. Three hundred and fifty-three patients were included in this study and additional follow up information was obtained for 184 patients. MD and SD were found in 40.2 and 16.7% of PD patients, respectively. Female gender, high HY, high UPDRS total and subtotal, and low MMSE and SE scores were significantly associated with depressive symptoms. According to changes in GDS score, 34% of patients remained stable, 35% showed an improvement, and 30.9% worsened in the follow up study. Gender, age, age of onset, HY, UPDRS, and PD duration are not related to depression outcome.

Aged↗
PubMed2003

[Management of human resources in neurology].

Neurology human resources comprise of the persons who make up the staff. Management tries to make the team both effective and efficient; consequently clear and quantifiable objectives together with resources according to real care needs, teaching, research and management are required. To calculate human resources, the suitability parameters recommended by scientific organisations must be used. To cover global care, 3.7 neurologists are needed for every 100,000 inhabitants. Management is the planning and selecting of staff and their incorporation into the dynamic of the team. It is also work performance training, job evaluation and the offering of opportunities to correct and improve. Personal competence is not a sufficient guarantee to ensure adequate performance. Motivation, team member encouragement to favour promotion, and support for professional career development are needed. Management is fomenting team work and stimulating staff participation in management organs, committees and hospital commissions.

Efficiency, Organizational↗
PubMed2002

[Determination of insulin, leptin and neuropeptide y by radioimmunoanalysis in patients with morbid obesity and anorexia nervosa after therapeutic intervention].

The present study was conducted in order to analyze the relationship existing between leptin, insulin and neuropeptide Y (NPY) levels in massive weight loss and weight recovery. Twenty-three patients with severe obesity, 23 patients with anorexia nervosa and 28 healthy control subjects were studied. Patients with severe obesity underwent a vertical banded gastroplasty followed by an 800 kcal/day diet during 16 weeks, with evaluation taking place before (Body mass index, BMI, 52,1 8 Kg/m2) and after the drastic weight loss (BMI 39,2 6,2 Kg/m2). Patients with anorexia nervosa were treated with nutritional therapy exclusively during 16 weeks, and they were evaluated in the low weight situation (BMI 15,3 1,7 Kg/m2) and after weight recovery (BMI 18,9 2,8 Kg/m2). Normal subjects had a normal BMI from 20 to 27 (average 21,8 2 Kg/m2). BMI, percentage of body fat, and serum levels of leptin, insulin, and NPY, were determined in each patient and normal subjects. In severe obese patients serum leptin and insulin decreased significantly after drastic weight reduction (leptin: from 48,8 19,2 to 24,3 9,8 ng/ml; insulin: from 26,2 10,8 to 18 6 U/ml). In patients with anorexia nervosa serum leptin mean levels were significantly higher after weight recovery (3,7 1,9 vs 9,2 5,1 ng/ml). In subjects with morbid obesity NPY levels decreased after weight loss below those of control group (43,5 16,1 vs 57,3 12,8 pmol/l). On the other hand, patients with anorexia nervosa had NPY levels superior to those of control group. In subjects with anorexia, NPY levels decreased after weight recovery (69,1 16,7 a 59,1 20,3 pmol/l). In the whole population, Leptin and NPY plasma levels were correlated with body fat percentage. Leptin was positively correlated with BMI and body fat percentage in obese and anorectic subjects after weight loss or recovery, respectively. NPY was inversely correlated with body fat percentage in controls and obese subjects before treatment. These data reveal that the concentration of serum leptin and NPY correlates significantly with the total adiposity in subjects with a wide weight range and caloric intake. Leptin plasma levels are proportional to fat stores in patients with severe obesity and anorexia nervosa after drastic weight loss or recovery, respectively. NPY serum levels are negatively correlated with de total body fat in normal weight subjects and obese patients in their initial weight.

Adult↗
PubMed2002

The importance of educational and psychological factors in Parkinson's disease quality of life.

OBJECTIVE: To define the factors correlated with quality of life (QoL) in patients with idiopathic Parkinson's disease (PD). BACKGROUND: PD has a substantial impact on QoL. Although several clinical factors have been associated with QoL in PD, the influence of patient's education still remains controversial. METHODOLOGY: A consecutive series of patients with PD were examined using the unified Parkinson's Disease Rating Scale (UPDRS part I, II, III), Schwab and England (SE), and Hoehn and Yahr stage (H&Y). QoL was rated with the PDQ-39, cognition with the Mini-Mental State examination (MMSE), and the presence of depressive symptoms with the geriatric depression scale (GDS). Patient's characteristics, estimated cumulative levodopa dose (CLD), UPDRS, H&Y, MMSE and GDS were correlated with the PDQ-39 using univariate and multiple regression analysis. RESULTS: A total of one hundred 58 patients (68 men, 90 women) with a mean age of 65.6 +/- 9.3 years, PD duration of 8.1 +/- 10.6 years, and education of 6.6 +/- 3.9 years were included. The mean PDQ-39 was 48.8 +/- 27.8, mean MMSE was 25.7 +/- 4, and mean GDS was 11.7 +/- 6.8. Using stepwise multiple regression analysis, the most important predictive factors were depression, UPDRS part I, UPDRS part II, and educational background, which accounted for a 61% of the variability of the PDQ-39 scores. CONCLUSIONS: In our PD sample, educational, behavioural, and psychological factors influenced life satisfaction more than physical ones.

Aged↗
PubMed2002

Adaptation and standardization of the geriatric evaluation of relative's rating instrument (GERRI) for Spain.

BACKGROUND: The Geriatric Evaluation of Relative's Rating Instrument (GERRI) is a scale that evaluates the frequencies of alterations in behavior and functional capacity over a two-week period prior to exploration. The scale depends on the observations done by a relative o first caregiver of the studied subject. AIM: To adapt and standardize the GERRI for the use in the Spanish population as a part of a general project to standardized cognitive and functional tests. METHOD: The scale was administered to 444 subjects: 249 controls, 85 mild memory-cognitive disorders without dementia subjects (DWD) and 110 patients with Alzheimer-type dementia (ATD). An across-sectional statistical study was conducted in our samples stratified by age, gender and education. We evaluated the reliability of repeatability of the test, the internal reliability and the age, sex and education effects on the score of the different subscales. We also took into account the diagnostical validity in the Alzheimer disease and finally we correlated this test results with Mini mental test. RESULTS: The demographic variables age and schooling were found to affect the GERRI subscales differently. Gender did not reach significance. Internal consistency for the GERRI-Social, -Mood and -Cognitive were 0.8620, 0.7647 and 0.9259, respectively. CONCLUSION: The Spanish version of the GERRI may be applied to Spanish clinical series because of its reliable internal consistency and reproducibility.

Adult↗
PubMed2001

Cloning, characterization and mRNA expression analysis of PVAS1, a type I asparagine synthetase gene from Phaseolus vulgaris.

A gene encoding a putative asparagine synthetase (AS; EC 6.3.5.4) has been isolated from common bean (Phaseolus vulgaris L.). A 2-kb cDNA clone of this gene (PVAS1) encodes a protein of 579 amino acids with a predicted molecular mass of 65,265 Da, an isoelectric point of 6.3, and a net charge of -9.3 at pH 7.0. The PVAS1 protein sequence conserves all the amino acid residues that are essential for glutamine-dependent AS, and PVAS1 complemented an Escherichia coli asparagine auxotroph, which demonstrates that it encodes a glutamine-dependent AS. The PVAS1 protein showed the highest similarity to soybean SAS1, and piled up with other legume ASs to form an independent dendritic group of type-I AS enzymes. Northern blot analyses revealed that the expression pattern of PVAS1 resembles that of PVAS2, another AS previously described in the common bean. Unlike PVAS2, however, PVAS1 was not expressed in the nodule and was not repressed by light, suggesting different functions for these two AS genes.

Amino Acid Sequence↗
PubMed2001

Clinical validity of the 'mini-mental state' for Spanish speaking communities.

The Mini-Mental State (MMS) is a brief structured test of cognitive function. The purpose of this study was to adapt and normalise MMS for the Spanish population. The test was administered to 450 subjects (253 control volunteers, 86 mild memory/cognitive impairment without dementia subjects - CIWD and 111 Alzheimer's Disease patients - AD). A cross-sectional statistical study in a population stratified by age and education was conducted. A more accurate diagnosis is provided by scores that have been adjusted for age and level of education. The recommended cut-off in our study was 24/25 (non-demented above 24). The adaptation and normalisation of MMS provides the Spanish population with a highly valuable screening tool.

Adult↗
PubMed2001

Thyroid-infiltrating B lymphocytes in Graves' disease are related to marginal zone and memory B cell compartments.

B lymphocytes that infiltrate the thyroid (Thy-B cells) in Graves' patients appear to be implicated in the pathophysiology of this disorder. The goal of the present study was to examine the nature of these Thy-B cells. To this end, Thy-B lymphocytes were isolated from surgical thyroidal samples, and their phenotype was determined by using mouse monoclonal antibodies (mAb) directed against a wide variety of surface markers, followed by flow cytometry multicolor analysis. The results show that most Thy-B cells (approximately 60%) exhibited IgM(+) IgD(low to -) surface immunoglobulin (Ig) profile, whereas the minor cell fraction (approximately 30%) consisted of switched IgG(+) memory B lymphocytes. Thy-B cells expressed low levels of CD5, CD23, and CD62L, which distinguished them from the resting B-cell pool, the major B-cell subset in the blood. In addition, they lacked CD38, CD10, and CD71, characteristic molecules for the germinal center B lymphocytes. In addition, Thy-B lymphocytes showed peculiar patterns both of adhesion molecules (CD62L(-), CD44(intermediate)), and of activation molecules (CD69(+), CD80(+), and, in part, CD95(+)). Taken together, these results suggest that the Thy-B lymphocyte subset consists of a combination of IgM(+) B cells resembling marginal zone B lymphocytes, and isotype-switched memory B cells.

Adolescent↗
PubMed2001

Urea is a product of ureidoglycolate degradation in chickpea. Purification and characterization of the ureidoglycolate urea-lyase.

A ureidoglycolate-degrading activity was analyzed in different organs of chickpea (Cicer arietinum). Activity was detected in all the tissues analyzed, but highest levels of specific activity were found in pods, from which it has been purified and characterized. This is the first ureidoglycolate-degrading activity that has been purified to homogeneity from any photosynthetic organism. Only one ureidoglycolate-degrading activity was found during the purification. The enzyme was purified 1,500-fold, and specific activity for the pure enzyme was 8.6 units mg(-1), which corresponds with a turnover number of 1,600 min(-1). The native enzyme has a molecular mass of 180 kD and consists of six identical or similar-sized subunits of 31 kD each. The enzyme exhibited hyperbolic, Michaelian kinetics for (-) ureidoglycolate with K(m) values of 6 and 10 microM in the presence or absence of Mn(2+), respectively. Optimum pH was between 7 and 8 and maximum activity was found at temperatures above 70 degrees C, the enzyme being extremely stable and resistant to heat denaturation. The activity was inhibited by EDTA and enhanced by several bivalent cations, thus suggesting that the enzyme is a metalloprotein. This enzyme has been characterized as a ureidoglycolate urea-lyase (EC 4.3.2.3), which catalyzes the degradation of (-) ureidoglycolate to glyoxylate and urea. This is the first time that such an activity is detected in plant tissues. A possible function for this activity and its implications in the context of nitrogen mobilization in legume plants is also discussed.

Amidine-Lyases↗