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S Bajo

Publications and source records attributed to S Bajo.

16 recordsLinked to original sources
PubMed2002

Transcriptional activation of the human insulin receptor gene by 1,25-dihydroxyvitamin D(3).

Treatment with 10(-8) M 1,25-dihydroxyvitamin D(3) for 24 h causes transcriptional activation of the human insulin receptor gene in U-937 human promonocytic cells. The activation seems to potentiate the response to insulin in terms of glucose oxidation. Wortmannin, a phosphatidylinositol 3-kinase inhibitor, causes a greater inhibition of insulin-stimulated glucose oxidation in 1,25-dihydroxyvitamin D(3)-treated cells than in untreated cells. This suggests a stimulation of phosphatidylinositol 3-kinase activity by 1,25-dihydroxyvitamin D(3), which could mediate, at least in part, the potentiation of the insulin response.

Androstadienes↗
PubMed2001

Determination of 228Ra, 226Ra and 224Ra in natural water via adsorption on MnO2-coated discs.

A fast procedure based on sorption of Ra on MnO2 coated polyamide discs is presented for determination of radium isotopes (i.e. 228Ra, 226Ra, 224Ra) in aqueous samples. The sample discs can be used directly for low-level alpha-spectrometry without the need for further separation and preparation methods to produce planar sample sources. While the activity of alpha-emitting 224Ra and 226Ra can be determined during a first measurement, beta-emitting 228Ra is obtained via ingrowth of the progeny 228Th on the same sample disc after a standing time of about six months. Calculations are presented for optimizing the analytical accuracy as well as for predicting the sorption yield or chemical recovery of radium on the sample disc as a function of exposure time because the sorption uptake proceeds with first-order kinetics. The analyses can be carried out on small samples of 0.5-11 and, for long counting times of one week and use of high-purity silicon surface barrier detectors, a detection limit of 0.15 mBq l-1 is obtained for 226Ra. Since the half-life of 224Ra is only 3.7 d and since 228Th (as a measure for 228Ra) is built up only partially on the sample disc, a slightly higher detection limit of 0.24 mBq l-1 results for the latter isotopes. The procedure is therefore sufficiently sensitive to allow the investigation of Ra isotope relationships in aquifers at typical environmental levels.

Adsorption↗
PubMed2001

228Ra/226Ra/224Ra and 87Sr/86Sr isotope relationships for determining interactions between ground and river water in the upper Rhine valley.

Ground and river waters of the upper Rhine valley (Alsace, France) were investigated for chemical composition of the major elements, Sr isotopes and radionuclides from the U and Th series. In particular, the isotope ratios and concentrations of Ra and Sr were used as geochemical tracers to distinguish between different types of water and their interactions. The bulk chemical analyses suggest that the surface waters in the Rhine valley can be described as mixtures between Ca-Na-HCO3-rich ground water and less mineralized slightly acidic river waters which have migrated through crystalline (mainly granitic) basement rocks of the Vosges mountains. Mixing of these waters yields positive correlation between bulk Sr, U, Ca and HCO3, indicating that carbonate-rich sediments are the main source of U and (non-radiogenic) Sr in the Rhine valley aquifers. The combination of the Ra and Sr isotope systems (228Ra/226Ra, 87Sr/86Sr) shows, however, that probably three sources contribute to the surface river waters in the upper Rhine valley, i.e. (i) a highly radiogenic crystalline component, (ii) a ground water source and, (iii) a third component from infiltrating Rhine water along the flow path of the parallel running river Ill in the northerly direction. The Sr and Ra isotope systems were also used to calculate small-scale mixing fractions of tributaries along the flow path of the Ill. Mixing ratios of non-pure end-member waters were determined using three isotope diagrams (i.e. 224Ra/226Ra vs. 228Ra/226Ra) and the results obtained with the Ra isotope system were found to be consistent with the data using Sr isotope relationships (i.e. 87Sr/86Sr vs. 1/Sr).

France↗
PubMed2001

Separation and measurement techniques for the determination of 228Th, 230Th and 232Th in various matrices.

Three analytical techniques are presented which are used at PSI for determination of U and Th isotopes (234U, 235U, 238U, 228Th, 230Th, 232Th) in different materials, i.e. environmental samples (soils, minerals) and dental ceramics as well as in urine for in vitro monitoring of potentially exposed workers. Depending on the sample quantity available and/or required detection limits the measurements are performed either directly via gamma spectrometry or via alpha particle counting with preceding separation chemistry. The separation methods applied are based on either extraction chromatography or on sorption of U and Th on actinide selective resin. Following sample digestion, chemical yield spike additions (232U, 225Th or 225Th), chemical purification and electro-depositional source preparation, alpha particle measurement is carried out using low-level alpha spectrometry. This technique allows detection limits of less than 0.2 mBq per counting source if the assay lasts over a few days and is therefore suitable for determination of trace quantities of short-lived 225Th that can be hardly detected by means of mass spectrometric techniques.

Humans↗
PubMed1999

A psychometric-genetic study of schizotypal disorder.

This study aimed to clarify the structure and the etiological constituents of schizotypal disorder (SPD) by directly interviewing pairs of twins. A latent class analysis was applied to each individual's outcome for specified SPD items, such that each subject's phenotype could be redefined in terms of individual probabilities of class membership. Intraclass correlations were then calculated for each twin pair, and a standard univariate twin model applied. The best latent class analysis solution encompassed a model with four latent classes (three latent classes of SPD subjects, one of non-SPD). The intraclass correlations revealed a moderate to high heritability for two out of three SPD classes and for the modal class (a class composed of subjects that possessed a conditional probability of belonging to any of the SPD classes). Model fittings revealed considerable variation in the extent to which the different classes of SPD were influenced by additive genetic constituents or non-genetic factors. Although these data confirm the importance of genetic contributors in determining liability to SPD and the schizophrenia spectrum, they indicate that there is a relationship between psychometric multidimensionality and etiological heterogeneity in SPD.

Adult↗
PubMed1999

First-cycle REM density in never-depressed subjects with borderline personality disorder.

BACKGROUND: There is much interest in the identification of polysomnographic markers of liability to the mood disorders that may predate the onset of illness in high-risk subjects, and/or remain altered after remission. One such putative marker is rapid eye movement (REM) density during the first REM period. METHODS: Never-depressed subjects with borderline personality disorder (BPD) as a group at high risk for the mood disorders were compared by continuous 48-hour ambulatory electroencephalographic monitoring to age- and gender-matched controls. RESULTS: Subjects with BPD had significantly higher REM density during the first REM period. One man with BPD who later committed suicide had REM density values exceeding the mean value of his group by 2 SD. CONCLUSIONS: These data extend the view that REM density in the first REM period can be a marker of liability to the mood disorders, as it is present in a group of young subjects at heightened risk for depression.

Adult↗
PubMed1999

Beta-endorphin levels in peripheral blood mononuclear cells and long-term naltrexone treatment in autistic children.

We assessed the clinical and biological effects of high-dose, long-term Naltrexone (NTX) treatment in 11 children (3-11 years), who had been diagnosed as autistic. The drug was given following an open design, for 12 weeks. Beta-Endorphin (beta-END) was assayed in peripheral blood mononuclear cells after 1 and 3 months of treatment, and 6 months after the completion of the course. Baseline beta-END levels were higher than in healthy age-matched controls. In seven patients treatment reduced beta-END, whose levels rose in four children. Autistic symptoms were considerably attenuated in all cases, with functional improvements involving several areas. There was a close correlation between the reduction in beta-END levels and the decrease of social withdrawal, and an evident--though weak--correlation between increases in beta-END and decreases in stereotypy and abnormal speech. Both effects persisted after treatment stopped.

Autistic Disorder↗
PubMed1998

Anticipation of age at onset in panic disorder.

OBJECTIVE: Anticipation (i.e., the decrease in age at onset or the increase in severity of a disorder in successive generations) has recently been reappraised as a key to understanding the genetics of some familial illnesses. The purpose of this study was to search for possible anticipation in panic disorder. METHOD: Thirty-eight unilineal, multigenerational families with multiple directly interviewed members who had panic disorder were compared across two successive generations for 1) age at the first panic attack, 2) age at the onset of panic disorder, and 3) the highest degree of agoraphobia ever experienced, as a tentative index of severity of illness. Intergenerational pairwise comparisons were implemented according to four different sampling schemes: random pairs, random transmitting pairs, all possible pairs, and all possible transmitting pairs. RESULTS: Life table analyses showed a significant decrease in the time before the first episode of panic and onset of panic disorder from the older to the younger generation. Evidence for anticipation was found for both indexes of onset in all four sampling schemes. No evidence of a generational effect on the index of severity of agoraphobia was found. Corrections for possible biases suggested that these results are not likely to be simple artifacts. CONCLUSIONS: Anticipation is supported in this specific set of families and, if it is confirmed by other studies, a role for trinucleotide repeat sequences may be considered to account for the familial aggregation of panic disorder.

Adolescent↗
PubMed1996

Arsenic concentrations in successive needle age classes of Norway spruce ( Picea abies [L.] Karst.).

Arsenic has been determined in needles of Norway spruce by neutron activation analysis. Trees from 8 sites grown under different soil and environmental situations have been sampled. Trees and needle age classes have been treated individually. Endogenous As concentrations in needles <100 ng/g have been detected. Concentrations increased linearly with the needle age class. This biodynamic behaviour is attributed tentatively to a predominant foliar uptake. Concentrations at the various sites differed by a factor of 7. No connection could be found between As concentrations in needles and total As in the soil or pH of the soil. However, the strong correlation between the endogenous and the exogenous concentrations, and differences of As concentrations in needles between different sites are thought to be due mainly to different inputs of As from the atmosphere.

Journal Article↗
PubMed1993

Tubulointerstitial nephropathy persisting 20 months after discontinuation of chronic intake of germanium lactate citrate.

Two young human immunodeficiency virus (HIV)-infected patients, a 25-year-old woman and a 26-year-old man, consumed large amounts of germanium lactate citrate 18% as an "immunostimulant" for 9 months. The woman, who had stage II HIV infection, developed severe renal dysfunction (creatinine clearance, 7 mL/min/1.73 m2) and slight proteinuria (0.28 g/d) after ingesting 260 g germanium lactate citrate 18%. Hepatomegaly with liver dysfunction (SGOT, 102 U/L; gamma-glutamyl transferase (GT), 159 U/L) and lactic acidosis (plasma lactate, 7.3 mmol/L) developed simultaneously. Renal biopsy revealed tubulointerstitial nephropathy with vacuolar cell degeneration and periodic acid-Schiff-positive intracellular deposits mainly in distal tubules. Liver biopsy disclosed severe hepatic steatosis; liver function tests returned to normal within 5 weeks. Since renal failure persisted for 2 years after ingestion of germanium (creatinine clearance, 14 mL/min/1.73 m2; proteinuria, 0.84 g/d), a second renal biopsy was performed, which showed marked but focal distal tubular atrophy and slight interstitial fibrosis. The male patient, who had stage III HIV infection, had ingested the same compound; he presented with a creatinine clearance of 43 mL/min/m2 and proteinuria of 0.36 g/d. Renal biopsy disclosed tubulointerstitial changes similar to those found in the female patient. After 9 months off germanium, creatinine clearance remained unchanged. Neutron activation analysis of all biopsy specimens in both cases documented germanium concentrations 10 to 70 times normal in renal tissue and 140 times normal in liver tissue.

Adult↗
PubMedDate not supplied

Major and trace elements in spruce needles by NAA.

Concentrations of 23 elements in needles of Norway spruce (P. abies) have been determined at 47 sites. It is shown that a thorough removal of the aerosols sitting on the needles surface is necessary in order to get the inherent needle concentrations. Neutron activation was used to determine concentrations from 10(-9) to 10(-2) g/g. Irradiation and counting conditions are given. The essential elements, Ca, Cl, Cu, Fe, K, Mg, Mn, P, Zn, and the nonessential elements, Al, As, Ba, Br, Co, Cs, Hg, La, Na, Rb, Sb, Sc, Sr, and V, could be determined. The concentrations of most elements are about a factor of 6 smaller than the mean concentrations in land plants. Analytical reproducibility was much better than the variation among individual trees, and the variation within sites is smaller than among sites. In general, essential elements have smaller variations than nonessential elements. For some elements, variations between sites are owing to differences in the soil pH or the emission situation.

Neutron Activation Analysis↗
PubMedDate not supplied

Fast methods for determination of antropogenic actinides and U/Th-series isotopes in aqueous samples.

Rapid and simple methods are applied at the PSI radioanalytical laboratory for determining anthropogenic actinides in waste and nuclear reactor waters (U, Pu, Am, Cm) as well as for analysis of naturally occurring alpha-emitters in continental river and ground water. Anion exchange chromatography followed by alpha-spectrometry as well as alpha/beta-LSC is applied for the reactor coolant waters. To avoid alpha-spectrum interference between 238Pu and 241Am at 5.5 MeV, the Pu-fraction is purified using anion exchange resin. Prior to the separation of the Pu-fraction, all actinides (U, Pu, Am, Cm) are adsorbed batch-wise under stirring onto Actinide Resin and subsequent decomposition of the reagent. The residue is then re-dissolved in a sulfate buffer solution for electrolytic deposition. In tabular water samples isotopes of Ra and Po are analyzed additionally via sorption onto manganese coated discs (Ra) and deposition on silver discs (Po). For counting times of 1 day and use of 0.1-1l sample aliquots, detection limits of a few mBql(-1) can be obtained easily.

Actinoid Series Elements↗
PubMedDate not supplied

Physiological and behavioral responses to minor stressors in offspring of patients with panic disorder.

Nineteen children born to patients with panic disorder and a comparison group of 16 children born to unaffected, non-psychiatric patient subjects exposed to novel and mildly stressful situations (visiting an unfamiliar place and watching a movie containing anxiogenic scenes) were assessed for their behaviors, heart rate, respiratory rate and salivary cortisol secretion. At arrival children born to patients with panic disorder had significantly longer latency of first spontaneous verbal comment, fewer prosocial behavior, and increased distress and attachment behavior. During the projection of the movie, children of the two groups differed for attachment, distress, and exploration behaviors. During the anxiogenic scenes children born to patients with panic disorder showed increased behavioral inhibition and higher heart rate. Autonomic modulation, respiratory rates and cortisol secretion were similar in the two groups. Some distinct psychophysiological patterns may constitute early manifestations of the transmitted liability to panic disorder.

Adaptation, Psychological↗
PubMedDate not supplied

An investigation of the co-occurrence of panic and somatization disorders through temperamental variables.

OBJECTIVE: The relation of temperamental dimensions to somatization and panic disorders in women was investigated. METHOD: Eighteen patients with both panic and somatization disorders, 41 patients with panic disorder only, and 22 control subjects were compared on the Tridimensional Personality Questionnaire. RESULTS: The patients with somatization and panic disorders had significantly higher Novelty Seeking values than both the patients with panic only and the control subjects. The only significant correlation was between the number of symptoms of somatization disorder and Novelty Seeking. The presence of other psychiatric conditions, comorbid with panic disorder in the patient group, did not affect significantly the temperamental variables. CONCLUSIONS: A temperamental disposition characterized by extraversion, impulsivity, as well as frequent exploratory activity and pursuit of novel and pleasurable activities may help differentiate women with both somatization and panic disorders from women with panic disorder only.

Adult↗