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1.
Phys Rev Lett ; 125(14): 142701, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064503

RESUMO

The neutron capture cross sections of several unstable nuclides acting as branching points in the s process are crucial for stellar nucleosynthesis studies. The unstable ^{171}Tm (t_{1/2}=1.92 yr) is part of the branching around mass A∼170 but its neutron capture cross section as a function of the neutron energy is not known to date. In this work, following the production for the first time of more than 5 mg of ^{171}Tm at the high-flux reactor Institut Laue-Langevin in France, a sample was produced at the Paul Scherrer Institute in Switzerland. Two complementary experiments were carried out at the neutron time-of-flight facility (n_TOF) at CERN in Switzerland and at the SARAF liquid lithium target facility at Soreq Nuclear Research Center in Israel by time of flight and activation, respectively. The result of the time-of-flight experiment consists of the first ever set of resonance parameters and the corresponding average resonance parameters, allowing us to make an estimation of the Maxwellian-averaged cross sections (MACS) by extrapolation. The activation measurement provides a direct and more precise measurement of the MACS at 30 keV: 384(40) mb, with which the estimation from the n_TOF data agree at the limit of 1 standard deviation. This value is 2.6 times lower than the JEFF-3.3 and ENDF/B-VIII evaluations, 25% lower than that of the Bao et al. compilation, and 1.6 times larger than the value recommended in the KADoNiS (v1) database, based on the only previous experiment. Our result affects the nucleosynthesis at the A∼170 branching, namely, the ^{171}Yb abundance increases in the material lost by asymptotic giant branch stars, providing a better match to the available pre-solar SiC grain measurements compared to the calculations based on the current JEFF-3.3 model-based evaluation.

2.
Neurologia ; 29(2): 76-85, 2014 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-23601757

RESUMO

INTRODUCTION: Numerous regions of the brain, such as the medial frontal cortex, orbitofrontal cortex, insula, and amygdala, participate in the autonomic control of cardiovascular functions such as heart rate. The degenerative process in frontotemporal dementia (FTD) involves the listed anatomical structures and may therefore produce dysautonomic cardiovascular symptoms. AIM: To observe whether or not non-cardiogenic bradycardia was more frequent in a group of patients with FTD than in subjects with mild cognitive impairment or dementia of a different aetiology. PATIENTS AND METHOD: Once patients with primary cardiac arrhythmia were excluded, we registered the heart rates of 258 patients with cognitive symptoms (36 with FTD, 22 with Alzheimer disease, 23 with vascular dementia, 10 with other dementias, and 167 with non-dementia cognitive impairment). RESULTS: Bradycardia (<60 beats/minute) was significantly more frequent in patients with FTD. This difference remained significant after excluding subjects undergoing treatment with a potentially bradycardic effect. Bradycardia was more prevalent in behavioural FTD cases than in cases of the aphasic variant, and we detected a trend toward higher frequency among patients with more pronounced right hemisphere atrophy. Moreover, mean systolic blood pressure in FTD patients was lower than in other participants, and systolic hypotension (<120 and <100mm Hg) was more prevalent. CONCLUSION: Bradycardia was more frequent in the FTD sample than in other patients with cognitive symptoms. Further investigations will be necessary before we may consider bradycardia to be a sign supporting diagnosis of FTD or its behavioural variant.


Assuntos
Bradicardia/etiologia , Demência Frontotemporal/complicações , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Disfunção Cognitiva/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Allergol Immunopathol (Madr) ; 41(1): 37-44, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-21940094

RESUMO

BACKGROUND: The diagnosis of anaphylactic reactions due to opiates during anaesthesia can be difficult, since in most cases various drugs may have been administered. Detection of specific IgE to poppy seed might be a marker for sensitisation to opiates in allergic people and heroin-abusers. This study assessed the clinical value of morphine, pholcodine and poppy seed skin-prick and IgE determination in people suffering hypersensitivity reactions during anaesthesia or analgesia and drug-abusers with allergic symptoms. METHODS: We selected heroin abusers and patients who suffered severe reactions during anaesthesia and analgesia from a database of 23,873 patients. The diagnostic yield (sensitivity, specificity and predictive value) of prick and IgE tests in determining opiate allergy was analysed. RESULTS: Overall, 149 patients and 200 controls, mean age 32.9 ± 14.7 years, were included. All patients with positive prick to opiates showed positive prick and IgE to poppy seeds, but not to morphine or pholcodine IgE. Among drug-abusers, 13/42 patients (31%) presented opium hypersensitivity confirmed by challenge tests. Among non-drug abusers, sensitisation to opiates was higher in people allergic to tobacco (25%), P<.001. Prick tests and IgE against poppy seed had a good sensitivity (95.6% and 82.6%, respectively) and specificity (98.5% and 100%, respectively) in the diagnosis of opiate allergy. CONCLUSIONS: Opiates may be significant allergens. Drug-abusers and people sensitised to tobacco are at risk. Both the prick and specific IgE tests efficiently detected sensitisation to opiates. The highest levels were related to more-severe clinical profiles.


Assuntos
Anafilaxia/diagnóstico , Codeína/análogos & derivados , Hipersensibilidade a Drogas/diagnóstico , Imunoglobulina E/sangue , Morfina , Morfolinas , Papaver/imunologia , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/imunologia , Adolescente , Adulto , Idoso , Anafilaxia/complicações , Estudos de Casos e Controles , Criança , Codeína/efeitos adversos , Codeína/imunologia , Hipersensibilidade a Drogas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morfina/efeitos adversos , Morfina/imunologia , Morfolinas/efeitos adversos , Morfolinas/imunologia , Ópio/administração & dosagem , Papaver/efeitos adversos , Valor Preditivo dos Testes , Sementes , Sensibilidade e Especificidade , Testes Cutâneos , Nicotiana/imunologia , Adulto Jovem
4.
Med Phys ; 48(1): 19-56, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32392626

RESUMO

BACKGROUND: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. AIMS: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. MATERIALS AND METHODS: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. RESULTS: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. DISCUSSION: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. CONCLUSION: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application.


Assuntos
Benchmarking , Física , Radiometria , Simulação por Computador , Método de Monte Carlo
5.
J Appl Microbiol ; 106(3): 886-94, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19191961

RESUMO

AIMS: To investigate the genetic diversity of Pseudomonas savastanoi pv. savastanoi strains and to look whether these strains were distributed to geographical location. METHODS AND RESULTS: Random amplification of polymorphic DNA (RAPD) was used to discriminate between 58 Tunisian strains and 21 strains from various other countries of P. savastanoi pv. savastanoi, the causal agent of olive knot disease. Isolates were separated into three groups by cluster analysis and principal coordinate analysis of RAPD fingerprint data obtained with three primers (OPR-12, OPX-7 and OPX-14). Group 1 contained isolates from the southeast of Tunisia and European strains. Group 2 comprised strains isolated from the north of Tunisia exclusively while group 3 encompassed the majority of isolates obtained from five orchards located in the centre of Tunisia. CONCLUSIONS: The results indicated that isolates of P. savastanoi pv. savastanoi were genetically distinct according to geographic regions. RAPD grouped isolates derived from the same orchard as identical. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first application of RAPD in the delineation of P. savastanoi pv. savastanoi strains.


Assuntos
Olea/microbiologia , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase/métodos , Pseudomonas/classificação , Pseudomonas/genética , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , DNA Bacteriano/genética , Dados de Sequência Molecular , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Tunísia
6.
Radiat Prot Dosimetry ; 180(1-4): 342-345, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29036572

RESUMO

33S is a stable isotope of sulphur which is being studied as a potential cooperative target for Boron Neutron Capture Therapy (BNCT) in accelerator-based neutron sources because of its large (n,α) cross section in the epithermal neutron energy range. Previous measurements resolved the resonances with a discrepant description of the lowest-lying and strongest one (at 13.5 keV). However, the evaluations of the major databases do not include resonances, except EAF-2010 which shows smaller values in this range than the experimental data. Furthermore, the glaring lack of data below 10 keV down to thermal (25.3 meV) has motivated a new measurement at n_TOF at CERN in order to cover the whole energy range. The inclusion of this new 33S(n,α) cross section in Monte Carlo simulations provides a more accurate estimation of the deposited kerma rate in tissue due to the presence of 33S. The results of those simulations represent the goal of this work.


Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Isótopos/análise , Nêutrons , Radiometria/métodos , Silício/análise , Radioisótopos de Enxofre/análise , Simulação por Computador , Humanos , Isótopos/química , Método de Monte Carlo , Proteção Radiológica , Radiometria/instrumentação , Dosagem Radioterapêutica , Silício/química , Radioisótopos de Enxofre/química
7.
J Chromatogr A ; 1175(2): 242-8, 2007 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17996879

RESUMO

A method for the rapid and simultaneous determination of ubiquinone-10 (coenzyme Q10, CoQ(10)) and the reduced form ubiquinol-10 (CoQ(10)H(2)) in human serum by LC-MS-MS with electrospray ionization (ESI) in the positive mode is here proposed. High selective identification and sensitive quantitation of both analytes have been carried out by monitoring the transition from the corresponding precursor ion to the product ion. Prior to the chromatographic analysis, serum samples (100 microl) were subject to a conventional pre-treatment based on protein precipitation, liquid-liquid extraction, evaporation to dryness and reconstitution with 95:5 methanol/hexane (v/v). The overall method has enabled to achieve low detection limits--5.49 and 15.8 ng/ml for CoQ(10) and CoQ(10)H(2), respectively--which were estimated with serum. The accuracy and potential matrix effects have been studied with spiked serum resulting recoveries between 92.82 and 106.97%. The proposed method has been applied to serum samples from healthy middle-age women, in which the CoQ(10)H(2)/CoQ(10) ratio has been used as marker of oxidative stress.


Assuntos
Cromatografia Líquida/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Ubiquinona/análogos & derivados , Humanos , Oxirredução , Estresse Oxidativo , Ubiquinona/sangue
8.
Phytopathology ; 96(3): 313-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18944447

RESUMO

ABSTRACT Pseudomonas savastanoi pv. savastanoi causes olive knot disease, which is present in most countries where olive trees are grown. Although the use of cultivars with low susceptibility may be one of the most appropriate methods of disease control, little information is available from inoculation assays, and cultivar susceptibility assessments have been limited to few cultivars. We have evaluated the effects of pathogen virulence, plant age, the dose/response relationship, and the induction of secondary tumors in olive inoculation assays. Most P. savastanoi pv. savastanoi strains evaluated were highly virulent to olive plants, but interactions between cultivars and strains were found. The severity of the disease in a given cultivar was strongly dependent of the pathogen dose applied at the wound sites. Secondary tumors developed in noninoculated wounds following inoculation at another position on the stem, suggesting the migration of the pathogen within olive plants. Proportion and weight of primary knots and the presence of secondary knots were evaluated in 29 olive cultivars inoculated with two pathogen strains at two inoculum doses, allowing us to rate most of the cultivars as having either high, medium, or low susceptibility to olive knot disease. None of the cultivars were immune to the disease.

9.
J Bone Miner Res ; 9(1): 53-7, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8154309

RESUMO

The thyroid calcitonin-producing C cells possess vitamin D receptors and synthesize the vitamin D-dependent calbindin D28K. The present study evaluates the possible direct or indirect influence of vitamin D on calcitonin secretion in the elderly. Serum calcitonin was measured before and after a short calcium infusion (1.5 mg/kg over 10 minutes) in nine normal young adults (30 +/- 4 years, mean +/- SEM) and eight elderly subjects (78 +/- 4 years). The test was repeated 48 h after the last of three intravenous injections of calcitriol (2 micrograms) given every other day. Basal serum calcium did not change, but basal calcitonin of the elderly increased from 7 +/- 1 to 10 +/- 1 pg/ml (p < 0.06), similar to basal values in young adults (11 +/- 1 pg/ml). The increase in calcitonin after calcium infusion increased from 8 +/- 1 to 14 +/- 1 pg/ml (p < 0.001) after calcitriol treatment and approached the increase in young adults (18 +/- 3 pg/ml). These data demonstrate that calcitriol can improve and nearly normalize the impaired calcitonin secretion of the mildly vitamin D-deficient elderly subjects without changes in serum calcium, whereas the inverse situation is observed for parathyroid hormone.


Assuntos
Calcitonina/metabolismo , Calcitriol/farmacologia , Deficiência de Vitamina D/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Calcitonina/sangue , Calcitriol/administração & dosagem , Calcitriol/uso terapêutico , Cálcio/sangue , Feminino , Humanos , Injeções Intravenosas , Masculino , Deficiência de Vitamina D/tratamento farmacológico
10.
J Clin Endocrinol Metab ; 75(2): 494-501, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1639950

RESUMO

UNLABELLED: The effect of age and vitamin D status on parathyroid function was studied in 129 healthy subjects between 20 and 89 yr old, with normal serum creatinine (less than 0.11 mmol/L), and living in Cordoba, Spain. Serum calcium and phosphorus as well as 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25-(OH)2D] decreased, whereas serum alkaline phosphatase increased, with age. Serum PTH also increased significantly with age when measured with either a carboxyl-terminal (cPTH) or an intact [PTH(1-84)] assay. The increase in cPTH, however, exceeded largely the increase in PTH(1-84) (+120% and +30% in subjects above 80 yr vs. young adults, respectively). Serum PTH(1-84) was negatively correlated with serum (ionized) calcium, 25OHD, and insulin-like growth factor I (IGF-I) but not with serum 1,25-(OH)2D. Serum 1,25-(OH)2D decreased with age and was highly correlated with serum 25OHD, cPTH, and IGF-I. In multiple regression analysis 50-60% of the variation of total and free 1,25-(OH)2D could be explained by serum 25OHD, PTH(1-84), and especially IGF-I, suggesting a possible role of decreasing GH and IGF-I concentrations in the mineral homeostasis of the elderly. Calcium infusion (1.5 mg/kg body weight over 10 min) decreased serum PTH(1-84) to below normal concentrations in young adults (nadir 14% of basal concentration), whereas the nadir in elderly subjects with secondary hyperparathyroidism was only 32% of basal concentration. The relative decrease was, however, identical in both age groups when simultaneous changes in ionized calcium were taken into account. Basal serum PTH(1-84) in selected elderly subjects (50 +/- 10 ng/L or 5 +/- 1 pmol/L, n = 10) decreased significantly (2.7 +/- 0.9 pmol/L, P less than 0.01) after 3 iv injections of 1,25-(OH)2D during 1 week without changes in serum (ionized) calcium. The PTH suppressibility after calcium infusion did not further improve. IN CONCLUSION: elderly patients with normal serum creatinine had a small (+30%) but significant increase in intact serum PTH concentration but the mean concentration still remained within the normal range. The PTH secretion remained normally suppressible by acute calcium infusion. Treatment with 1,25-(OH)2D decreased basal calcium-PTH setpoint without further additional effects during calcium infusion.


Assuntos
Envelhecimento/fisiologia , Glândulas Paratireoides/efeitos dos fármacos , Vitamina D/farmacologia , Adulto , Idoso , Cálcio/farmacologia , Estudos Transversais , Di-Hidroxicolecalciferóis/sangue , Feminino , Humanos , Hidroxicolecalciferóis/sangue , Fator de Crescimento Insulin-Like I/análise , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/fisiologia , Hormônio Paratireóideo/sangue
11.
Mech Ageing Dev ; 102(2-3): 293-8, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9720659

RESUMO

Beta-2 microglobulin (beta2m), the water soluble extrinsic light chain of class I MHC, has been recently isolated from the adult bone culture medium. Serum beta2m plays a role as a bone-derived growth factor regulating both osteoblast and osteoclast cell activity. Serum beta2m has been proposed as a bone remodeling biological marker in high bone turnover conditions. The purpose of our study was to determine the relationship between beta2m and vitamin D status in post-menopausal women. We have studied 44 healthy women from 20 to 80 years with normal hepatic and renal function, without diabetes mellitus and/or inflammatory, tumoral or infectious diseases. We measured the serum levels of calcium, phosphorus, parathyroid hormone (PTH), vitamin D binding protein (DBP), 25-OHD3 (calcidiol), 1,25(OH)2D3 (calcitriol) and beta2m. Serum beta2m levels increased with age (r = 0.54, P < 0.001). Post-menopausal women had higher serum levels than pre-menopausal women of beta2m (1.76 +/- 0.22 mg/l vs. 1.35 +/- 0.2 mg/l, P < 0.01); PTH (61.5 +/- 7.5 ng/ml vs. 39 +/- 6 ng/ml, P < 0.001) and lower serum levels of 25-OHD3 (7.5 +/- 2.3 ng/ml vs. 18.2 +/- 2.5 ng/ml, P < 0.001). Moreover, serum levels of beta2m were negatively correlated with 25-OHD3 (r = -0.34, P < 0.05) and with ionized calcium (r = -0.45, P < 0.01) and positively with PTH (r = 0.48, P < 0.01). These results support the role of beta2m as a regulator of bone metabolism and its potential use as a marker of high bone turnover in post-menopausal women, specially in elderly women with vitamin D deficiency and secondary hyperparathyroidism.


Assuntos
Envelhecimento/fisiologia , Remodelação Óssea/fisiologia , Microglobulina beta-2/metabolismo , Adulto , Idoso , Envelhecimento/sangue , Biomarcadores , Feminino , Humanos , Pessoa de Meia-Idade
12.
J Steroid Biochem Mol Biol ; 89-90(1-5): 209-14, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15225773

RESUMO

The vdr gene is a candidate for osteoporosis susceptibility, with conflicting results in association studies. We have designed and optimized an individual allele-specific and DNA pooling PCR-based methodology to quantitate BsmI and FokI polymorphisms of the vdr gene and studied single-nucleotide polymorphisms (SNPs) from pooled DNA samples. The allele frequency in DNA pooling experiments has been analyzed by kinetic PCR: quantitative real-time PCR (QRT-PCR). A Spanish cohort of 225 healthy postmenopausal women was studied. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA) and quantitative ultrasound calcaneous densitometry. Allele-specific PCR amplification of BsmI and FokI genes showed full concordance with the PCR-RFLP approach. The prevalence of the three BsmI VDR genotypes was 19.1, 44.9 and 36.0% for BB, Bb and bb, respectively. In the case of the FokI locus, the prevalence of genotypes was 40.4, 48.0 and 11.6% for FF, Ff and ff, respectively. No positive correlation was found between polymorphism and BMD. The DNA pooling procedure was validated. No differences were found in allele frequencies and T-score data obtained using the high throughput DNA pooling approach, as compared to known individual frequencies. In our hands, this is a very useful approach to study quantitative (thus polygenic) traits like osteoporosis susceptibility.


Assuntos
Alelos , DNA/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Frequência do Gene , Polimorfismo Genético , Receptores de Calcitriol/genética , Absorciometria de Fóton , Sequência de Bases , Estudos de Coortes , Primers do DNA , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Steroid Biochem Mol Biol ; 89-90(1-5): 473-7, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15225823

RESUMO

A new fully automated high-performance liquid chromatography (HPLC) method using 1 ml of serum has been developed for the determination of retinol (Vitamin A), alpha-tocopherol (Vitamin E), 25-hydroxyvitamin D(3) and 24 R,25-hydroxyvitamin D(3). The eluate was monitored with a photodiode-array detector at three wavelengths-namely: 265 nm for Vitamin D(3), 291 nm for Vitamin E and 325 nm for Vitamin A. The detection limits were equal to or lower than 1 ng ml(-1) for all vitamins. The linearity obtained with serum samples (standard addition method) gives correlation coefficients (r(2)) ranging between 0.999 and 0.996 in all cases, with standard deviation of the slope between 3.2 and 1.6%. The repeatability was between 4.0 and 6.0% and the within-laboratory reproducibility was lower than 10% in all cases. The most outstanding features of the present method are its ease of use, its rapidity and fully automation, which enables its use for routine analysis. The time required per sample was 30 min, because the overlapped development of the steps. This method was used for the determination of normality range of these vitamins in healthy people in the 18-80-year-old interval.


Assuntos
Automação , Cromatografia Líquida de Alta Pressão/métodos , Vitaminas/sangue , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solubilidade
14.
Clin Chim Acta ; 274(2): 139-49, 1998 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-9694582

RESUMO

A method for the determination of hydroxyvitamin D3 metabolites (25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D3 and 1,25-didydroxyvitamin D3) based on a continuous cleanup/ preconcentration procedure coupled with HPLC and UV-detection is reported here. The method exhibits a linear range between 0.05 and 100 ng/ml (r2 = 0.9917) with CV values lower than 6.5%, and has been checked by applying it to plasma samples from a hospital with acceptable recoveries. The results compare well with those obtained by routine radioimmunoassay (y = 2.784+/-1.37 + 0.333+/-0.05 sigma(yx), r = 0.8233, n = 19 for 25-hydroxyvitamin D3). The sampling frequency was 4 h(-1); 12 analytes h(-1).


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Hidroxicolecalciferóis/sangue , Humanos , Radioimunoensaio , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta
15.
Talanta ; 50(1): 57-66, 1999 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-18967694

RESUMO

A new method for the determination of the hydroxymetabolites of vitamin D(3) (24,25-(OH)(2)-D(3), 1,25-(OH)(2)-D(3) and 25-OH-D(3)) in plasma is reported. The method is based on the integration of three subsystems: continuous cleanup/preconcentration, HPL separation and post-column fluorimetric derivatisation. The derivatising subsystem is based on the dehydration reaction undergone by the secosteriod molecules in a strong-acid medium. The calibration graphs were run between 0.1 pg ml(-1) and 100 ng ml(-1) for each analyte with excellent regression coefficients (>/=0.9933) in all cases. The precision at two concentration levels was established with acceptable RSDs (%) in all instances (values between 2.1 and 5.2%). The method was also checked by applying it to human plasma samples spiked with the target analytes and the recoveries ranged between 86 and 106%.

16.
J Pharm Biomed Anal ; 35(3): 575-82, 2004 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-15137982

RESUMO

A new fully automated method for the determination of metabolites of Vitamin D(3) and Vitamins A and E has been developed. A robotic station for liquid-liquid extraction, connected on line with an automatic system for solid-phase extraction (Prospekt) and a liquid chromatograph were used and the complexity of the overall method was overcome by full automation. The eluate from the chromatograph was monitored by a photodiode-array detector at three wavelengths, namely, 265 nm for Vitamin D(3) metabolites, 291 nm for Vitamin E and 325 nm for Vitamin A-which are the maximum absorption wavelengths for the analytes. The time required per sample analysis was 35 min because of the overlapping development of the steps. The linearity obtained for serum samples (standard addition method) gives correlation coefficients (r(2)) ranging between 0.996 and 0.989, with standard deviation of the slope between 4.0 and 4.9%. The repeatability was between 4.0 and 6.0% and the within-laboratory reproducibility was lower than 10.1% in all cases-both expressed as relative standard deviation-for low concentrations of the analytes, namely, 3 ng/ml for 24,25(OH)(2) dihydroxyvitamin D(3), 10 ng/ml for 25(OH) hydroxyvitamin D(3), 100 ng/ml for Vitamin A and 2 microg/ml for Vitamin E. The method has been validated using a CRM (NIST, SRM968c).


Assuntos
24,25-Di-Hidroxivitamina D 3/sangue , Calcifediol/sangue , Tecnologia Farmacêutica/métodos , Vitamina A/sangue , Vitamina E/sangue , Colecalciferol/metabolismo , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Tecnologia Farmacêutica/instrumentação
17.
J Pharm Biomed Anal ; 20(1-2): 1-17, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10704005

RESUMO

The steps involved in the methods for the determination of vitamin D3 metabolites (namely, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, 24,25-dihydroxyvitamin D3) mainly in clinical samples are critically reviewed. Sample pretreatment (e.g. deproteinization, saponification, liquid liquid and liquid solid extraction, etc.) as a function of both type of sample and detection system, quantitation based on protein saturation and liquid as well as gas chromatography are discussed. The chemical principles on which the methods are based and the derivatization procedures, which facilitate separation and/or detection, are also commented upon. Finally, the future prospects of the research on methods for the determination of these metabolites are outlined.


Assuntos
24,25-Di-Hidroxivitamina D 3/análise , Calcifediol/análise , Calcitriol/análise , 24,25-Di-Hidroxivitamina D 3/química , Animais , Calcifediol/química , Calcitriol/química , Cromatografia Gasosa , Humanos
18.
Rev Esp Enferm Dig ; 93(3): 156-63, 2001 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-11469076

RESUMO

OBJECTIVE: To test the hypothesis that the heterozygous state for HFE gene mutations involved in the pathogenesis of hemochromatosis, that may induce an increase of hepatic iron content, may aggravate the liver damage induced by prolonged and excessive use of ethanol. PATIENTS AND METHODS: C282Y and H63D mutations of HFE gene were identified through polymerase chain reaction (PCR) on leukocyte DNA, in 125 consecutive patients diagnosed of advanced alcoholic liver disease (109 men, mean age 54 years, SD 11) and 181 healthy controls. All subjects were white Spaniards. RESULTS (CASES/CONTROLS): 1. Genotype distribution: a) mutation C282Y: no homozygotes, 10/23 heterozygotes, 115/158 normal (p = 0.60); b) mutation H63D: 9/5 homozygotes, 46/52 heterozygotes, 70/124 normal (Chi square 6.51, p = 0.039). 2. Allele frequencies: a) mutation C282Y: 240/339 normal, 10/23 mutated (p = 0.21); b) mutation H63D: 186/300 normal, 64/62 mutated (odds ratio 1.66, 95% CI 1.10-2.52, p = 0.01). CONCLUSIONS: Our results suggest that H63D mutation of the HFE gene, but not the C282Y mutation, is associated to the risk of developing advanced liver alcoholic disease.


Assuntos
Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Hepatopatias Alcoólicas/genética , Proteínas de Membrana , Mutação/genética , Adulto , Idoso , DNA/genética , Feminino , Frequência do Gene , Proteína da Hemocromatose , Humanos , Hepatopatias Alcoólicas/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
An Med Interna ; 11(12): 591-4, 1994 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-7734666

RESUMO

We present a member of a family with glycogen deposit disease (GDD) type III (Forbes-Cori's disease) confirmed postmortem through enzymatic analysis of the hepatic and muscular tissues, coinciding with a Crohn's disease associated to ankylopoietic spondylitis, with final development of an extended secondary amiloidosis, all of these diagnosis established in life of the patient and verified in necropsy. We comment this rare finding, the absence of similar cases in the bibliography and the fortuitous nature of this association given the impossibility to suggest another relationship.


Assuntos
Amiloidose/etiologia , Doença de Crohn/complicações , Doença de Depósito de Glicogênio Tipo III/complicações , Espondilite Anquilosante/complicações , Adulto , Amiloidose/genética , Doença de Crohn/genética , Doença de Depósito de Glicogênio Tipo III/genética , Doença de Depósito de Glicogênio Tipo III/patologia , Humanos , Masculino , Linhagem , Espondilite Anquilosante/genética
20.
An Med Interna ; 19(5): 234-6, 2002 May.
Artigo em Espanhol | MEDLINE | ID: mdl-12107997

RESUMO

Usually, cytomegalovirus infection dosen't cause symptoms in immunocompetents patients although sometimes can. In alcoholic and cirrhotic subjects can cause several and fatal infections. We describe a case of disseminated cytomegalovirus infection in an alcoholic patient with excellent response to ganciclovir.


Assuntos
Infecções por Citomegalovirus , Imunocompetência , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
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