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Biomedical subjects

J Sanz

Publications and source records attributed to J Sanz.

At least 55 records · Page 3Linked to original sources
PubMed2002

MultiSimplex optimisation of the solid-phase microextraction-gas chromatographic-mass spectrometric determination of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and phthalates from water samples.

Solid-phase microextraction coupled to GC-MS was optimised for the determination of polycyclic aromatic hydrocarbons (PAHs), phthalate esters and polychlorinated biphenyls (PCBs) in water samples. A 30-microm polydimethylsiloxane fiber was immersed in a 30-ml water sample that contained the analytes of interest (PAHs, PCBs and phthalate esters) and the variables studied were extraction time (15-60 min), extraction temperature (30-90 degrees C), desorption time (1-5 min), desorption temperature (220-270 degrees C) and the addition of sodium chloride (0-9 g). The MultiSimplex programme based on the simplex algorithm was used to establish the optimal conditions. MultiSimplex allowed the simultaneous study of the variables mentioned above and considered the answers of all types of compounds studied in this work. Thus, the optimal conditions obtained allowed the simultaneous determination of PAHs, phthalate esters and PCBs. Furthermore, the accuracy and repeatability of the developed method were calculated from water samples spiked at known concentrations of the analytes. Finally, the optimised method was used to analyse water samples from different sampling points of the Urdaibai and Nerbioi-Ibaizabal estuaries (Biscay, Spain).

Gas Chromatography-Mass Spectrometry↗
PubMed2002

Nonlinear theory of the ablative Rayleigh-Taylor instability.

A fully nonlinear sharp-boundary model of the ablative Rayleigh-Taylor instability is derived and closed in a similar way to the self-consistent closure of the linear theory. It contains the stabilizing effect of ablation and accurately reproduces the results of 2D DRACO simulations. The single-mode saturation amplitude, bubble and spike evolutions in the nonlinear regimes, and the seeding of long-wavelength modes via mode coupling are determined and compared with the classical theory without ablation. Nonlinear stability above the linear cutoff is also predicted.

Journal Article↗
PubMed2002

Ecstasy-induced psychotic disorder: six-month follow-up study.

OBJECTIVE: To describe the psychiatric symptoms manifested by persons diagnosed for the first time as having ecstasy-induced psychotic disorder and to explore the evolution of their symptoms over a 6-month period. DESIGN: Observational study with a 6-month follow-up. METHOD: The subjects studied were 32 ecstasy consumers who were treated at two drug-dependency outpatient centers for hallucinatory-delusive manifestations and who were diagnosed as having ecstasy-induced psychotic disorder according to DSM-IV criteria. For the assessment of the intensity of the syndrome and its follow-up, the Brief Psychiatric Rating Scale (BPRS), the Hamilton Depression Rating Scale (HDRS) and the Clinical Global Impression (CGI) were used at the outset and after 1, 3 and 6 months. All subjects received treatment with olanzapine. RESULTS: The treatment program was completed by 96.9% of the patients. At the baseline assessment, a high incidence of symptoms of a severe psychiatric disorder was observed. From the first month the psychotic symptoms (BPRS) were considerably reduced with treatment, with the most severe positive symptoms remitting in the first 3 months. The three assessment indicators (BPRS, HDRS and CGI) showed a statistically significant clinical reduction over the 6 months of the assessment period. Furthermore, no relevant side effects were noted. CONCLUSIONS: In its initial manifestations, a drug-induced psychotic syndrome includes marked symptoms meeting the criteria of a severe psychotic disorder, with the presence of considerable positive and negative symptoms. Olanzapine has been shown to be very effective in these situations and its use is suggested as first-choice therapy.

Adolescent↗
PubMed2001

Failure of a short-term prednisone regimen to prevent nevirapine-associated rash: a double-blind placebo-controlled trial: the GESIDA 09/99 study.

OBJECTIVES: Rash is the most frequent adverse event associated with nevirapine. The use of prednisone has been controversial in this setting. A double-blind placebo-controlled study was performed to evaluate its efficacy in nevirapine-induced rash prevention. DESIGN: Multicentered, randomized, double-blind, placebo-controlled clinical trial with prednisone (30 mg/day x 2 weeks). INCLUSION CRITERIA: HIV-1 infection; CD4 count >200 cells/mm3; plasma viral load (PVL) <5 log10 copies/ml; nevirapine (200 mg/day x 2 weeks, followed by 200 mg twice daily) plus stavudine and didanosine. Clinical follow-up was performed at 15, 30, and 60 days and thereafter every 2 months. RESULTS: In all, 75 evaluable patients were enrolled (39 prednisone/36 placebo). Median baseline CD4 + cell count was 390 cells/mm3 and PVL, 20,200 copies/ml. Overall, nine cases of rash (12.5%) were detected, seven (18%) in the prednisone group and two (5.5%) in the placebo group (odds ratio [OR], 3.85; 95% confidence interval [CI], 0.65-29.3; p =.11). Incidence of moderate-to-severe rashes leading to nevirapine withdrawal was 13.5% (5 of 37) in the prednisone group and 3% (1 of 35) in the placebo group ( p =.2). Median time to rash in both groups was 16 days. Adverse events that motivated withdrawal of therapy appeared in 6 patients from the prednisone group (15.4%) and 3 from the placebo group (8.3%) ( p =.3). CONCLUSION: Short-term prednisone administration does not prevent nevirapine rash, but might even increase its incidence.

Adult↗
PubMed2001

Analysis of the volatile components of Argyranthemum adauctum (Link.) Humphries by gas chromatography-mass spectrometry.

The volatile constituents of the essential oil of Argyranthemum adauctum (Link.) Humphries extracted by steam distillation have been studied by GC-MS. A total of 60 compounds have been identified representing the 89.8% of the oil. The major constituents were found to be beta-pinene (27.4%) and santolinatriene (22.6%). This is the first report on the chemical compounds of the oil of this species.

Asteraceae↗
PubMed2001

Analysis of Origanum vulgare volatiles by direct thermal desorption coupled to gas chromatography-mass spectrometry.

Volatile components of samples of a population of Spanish Origanum vulgare have been analyzed by direct thermal desorption coupled to GC-MS. The method is fast and reliable and requires a low amount of sample, allowing analysis of leaves and flowers from a single individual plant. Volatile yield is highly variable among individual plants and concentration also presents a high variation for most Origanum volatile compounds, linalool being the main component in most samples. Statistical analyses are applied in order to find patterns in composition data.

Adsorption↗
PubMed2001

P300 amplitude as a possible correlate of frontal degeneration in schizophrenia.

The existence of neurodegeneration is a debated issue in schizophrenia research. The P300 component of event-related electrical potentials (ERP) has been related to the different degree of damage to gray and white matter. This study explores the possible relationship between P300 amplitude and/or latency and the existence of degenerative processes in schizophrenia, by assessing its correlation with volume of sulcal CSF and duration of illness, as transversal indicators of neurodegeneration. Nineteen patients (14 males, 5 females) and 13 controls (6 males, 7 females) were studied with MRI and electrophysiological records (P300). The possible influence of sex and age at the time of the exploration was statistically controlled in both groups. The results show a significant negative correlation between P300 amplitude and prefrontal CSF volume in the patient group. A lower though still significant correlation was also found between P300 amplitude and duration of illness, whereas no correlation was found in the control group. These results support the hypothesis that P300 amplitude may be interpreted as a marker of neurodegeneration in schizophrenia.

Adolescent↗
PubMed2001

Origin of constant loss in ionic conductors.

We have analyzed the constant loss contribution to the ac conductivity in the frequency range 10 Hz-1 MHz and temperatures down to 8 K, for two Li ionic conductors, one crystalline (Li(0.18)La(0.61)TiO(3)) and the other glassy (61SiO(2);35Li(2)O.3Al(2)O3.P(2)O(5)). As temperature is increased a crossover is observed from a nearly constant loss to a fractional power law frequency dependence of the ac conductivity. At any fixed frequency omega, this crossover occurs at a temperature T such that omega approximately nu(0)exp(-E(m)/k(B)T), where nu(0) is the attempt frequency and E(m) is identified with the barrier for Li+ ions to leave their wells.

Journal Article↗
PubMed2001

Seasonal variation in chemical constituents of Santolina rosmarinifolia L. ssp. rosmarinifolia.

The seasonal variation of the essential oil extracts from the aerial parts of a Santolina rosmarinifolia population has been studied. Oil yields increased in the months of March, April, May and June. Oil concentration showed significant correlations with both precipitation (positive) and temperature (negative). Essential oil main components were sabinene, beta-pinene, myrcene, beta-phellandrene, limonene, 1,8-cineole, artemisia ketone, terpinen-4-ol, capillene, ar-curcumene and beta-eudesmol. Monoterpenes like beta-phellandrene, limonene and 1,8-cineole showed a significant negative correlation with temperature, while capillene presented a strong positive correlation with precipitation. The rest of the essential oil components did not show any noticeable trend.

Journal Article↗
PubMed2001

The decade 1989-1998 in Spanish psychology: an analysis of research in personality, assessment, and psychological treatment (clinical and health psychology).

The aim of this study is to analyze Spanish research published between 1989 and 1998 in clinical psychology and its most directly related psychological disciplines: personality psychology, psychopathology, differential psychology, health psychology, and psychological assessment. A search was performed in the various databases of the works published in that decade by Spanish university professors who investigate in these areas. Their localization was verified by direct correspondence with the professors, to whom was also sent a questionnaire to evaluate their research field and preferred theoretical approach. The 2,079 works located allowed me to identify 85 different research trends. These research trends are characterized by the predominance of applied studies over basic studies, of empirical research over theoretical research, and of the cognitive-behavioral approach over the rest of the theoretical orientations. In addition, various bibliometrical indicators of production, dissemination, and impact were calculated. They revealed that productivity and dissemination of Spanish research in these areas grew considerably during this 1989-98 period.

Bibliometrics↗
PubMed2001

BRCA2 mutation analysis of 87 Spanish breast/ovarian cancer families.

BACKGROUND: It is estimated that about 5% -10% of breast cancer (BC) cases is due to inherited predisposition. Early works reported that 45%-50% of site-specific BC families had BRCA1 mutations and 25%-35% BRCA2 mutations. However, these percentages could have been overestimated and likely vary among the populations studied. PATIENTS AND METHODS: We analysed the BRCA2 gene in 87 Spanish breast/ovarian cancer families in which the BRCA1 mutation screening was negative. RESULTS: We detected 15 (17.2%) disease-causing mutations and 11 polymorphisms and unclassified variants. Four mutations were recurrent, and five were novel. Seven (47%) mutations were found in site-specific female BC families, five (33%) in families with OC cases, and three (20%) mutations in families with male BC cases. There was incomplete penetrance of the mutations in some families, and considerable phenotypic variations with respect to the age of diagnosis and cancer types. CONCLUSIONS: The percentage of mutations detected reinforces the possibility that some of these families have mutations in genes other than BRCA1 or BRCA2 that confer lower BC risks.

Adult↗
PubMed2001

Clinical and pathological findings of BRCA1/2 associated breast cancer.

It is not known if the behaviour of hereditary breast cancer (HBC) differs from that of sporadic breast cancer (BC). The aim of the present study was to analyze clinical-pathological characteristics in patients with BRCA1/2-mutation associated to BC. These data could be useful in the management of HBC. This study includes 17 patients with BC in whom a germ-line BRCA1/2-mutation was diagnosed. The patients were from 10 different families, and four patients had no family history of BC or ovarian cancer (OC). The study of mutations was with the protein truncation test (exon 11 for BRCA1, exons 10 and 11 for BRCA2) and sequencing (the rest of exons). At diagnosis the mean age was 37 years (28-54). Only 3/17 patients presented with involvement of axillary nodes; no patient was diagnosed with metastatic disease. All cases were infiltrating ductal carcinoma; two of them were medullary carcinoma. Histological grade was available in 13/17 cases, with grade III being the most frequent (12/13). Hormonal receptors were negative in 8/10 patients. The mean follow-up was 129 months (23-223). There were three local recurrences at 17, 108 and 151 months; and two distant relapses at 15 months (complete remission) and 92 months. There were three diagnosed contralateral BC. Hereditary breast cancer has malignant pathological features, but the clinical behaviour may be less aggressive than sporadic breast cancer in the same age group.

Journal Article↗
PubMed2001

Direct thermal desorption in the analysis of cheese volatiles by gas chromatography and gas chromatography-mass spectrometry: comparison with simultaneous distillation-extraction and dynamic headspace.

Direct thermal desorption (DTD) has been used as a technique for extracting volatile components of cheese as a preliminary step to their gas chromatographic (GC) analysis. In this study, it is applied to different cheese varieties: Camembert, blue, Chaumes, and La Serena. Volatiles are also extracted using other techniques such as simultaneous distillation-extraction and dynamic headspace. Separation and identification of the cheese components are carried out by GC-mass spectrometry. Approximately 100 compounds are detected in the examined cheeses. The described results show that DTD is fast, simple, and easy to automate; requires only a small amount of sample (approximately 50 mg); and affords quantitative information about the main groups of compounds present in cheeses.

Cheese↗