A gene-environment interaction analysis of plasma selenium with prevalent and incident diabetes: The Hortega study.

BACKGROUND: Selenium and single-nucleotide-polymorphisms in selenoprotein genes have been associated to diabetes. However, the interaction of selenium with genetic variation in diabetes and oxidative stress-related genes has not been evaluated as a potential determinant of diabetes risk. METHODS: We evaluated the cross-sectional and prospective associations of plasma selenium concentrations with type 2 diabetes, and the interaction of selenium concentrations with genetic variation in candidate polymorphisms, in a representative sample of 1452 men and women aged 18-85 years from Spain. RESULTS: The geometric mean of plasma selenium levels in the study sample was 84.2µg/L. 120 participants had diabetes at baseline. Among diabetes-free participants who were not lost during the follow-up (N=1234), 75 developed diabetes over time. The multivariable adjusted odds ratios (95% confidence interval) for diabetes prevalence comparing the second and third to the first tertiles of plasma selenium levels were 1.80 (1.03, 3.14) and 1.97 (1.14, 3.41), respectively. The corresponding hazard ratios (95% CI) for diabetes incidence were 1.76 (0.96, 3.22) and 1.80 (0.98, 3.31), respectively. In addition, we observed significant interactions between selenium and polymorphisms in PPARGC1A, and in genes encoding mitochondrial proteins, such as BCS1L and SDHA, and suggestive interactions of selenium with other genes related to selenoproteins and redox metabolism. CONCLUSIONS: Plasma selenium was positively associated with prevalent and incident diabetes. While the statistical interactions of selenium with polymorphisms involved in regulation of redox and insulin signaling pathways provide biological plausibility to the positive associations of selenium with diabetes, further research is needed to elucidate the causal pathways underlying these associations.

Correlation of zinc with oxidative stress biomarkers.

Hypertension and smoking are related with oxidative stress (OS), which in turn reports on cellular aging. Zinc is an essential element involved in an individual's physiology. The aim of this study was to evaluate the relation of zinc levels in serum and urine with OS and cellular aging and its effect on the development of hypertension. In a Spanish sample with 1500 individuals, subjects aged 20-59 years were selected, whose zinc intake levels fell within the recommended limits. These individuals were classified according to their smoking habits and hypertensive condition. A positive correlation was found (Pearson's C=0.639; p=0.01) between Zn serum/urine quotient and oxidized glutathione levels (GSSG). Finally, risk of hypertension significantly increased when the GSSG levels exceeded the 75 percentile; OR=2.80 (95%CI=1.09-7.18) and AOR=3.06 (95%CI=0.96-9.71). Low zinc levels in serum were related with OS and cellular aging and were, in turn, to be a risk factor for hypertension.

Do genes modify the association of selenium and lipid levels?

The interaction of selenium, a component of antioxidant selenoproteins, with genetic variation in lipid-related pathways has not been evaluated earlier as a potential determinant of blood lipid levels. We aimed at evaluating the effects of gene-environment interactions between plasma levels of selenium and polymorphisms in lipid metabolic pathways on plasma lipid levels in a study population from Spain (N=1,315). We observed statistically significant associations between plasma selenium and lipid levels (differences in total, low-density lipoprotein [LDL]-cholesterol, and triglycerides comparing the 80th with the 20th percentiles of plasma selenium levels were, respectively, 12.0 (95% confidence interval 6.3, 17.8), 8.9 (3.7, 14.2), and 9.0 (2.9, 15.2) mg/dl). We also found statistically significant interactions at the Bonferroni-corrected significance level (p=0.0008) between selenium and rs2290201 in FABP4 for total and LDL cholesterol levels and rs1800774 in CETP for elevated LDL cholesterol. Other polymorphisms showed statistically significant differential associations of plasma selenium levels and lipids biomarkers at the nominal p-value of 0.05. Reported statistical interactions with genes involved in lipid transport and transfer provide biological support to the positive associations of selenium with lipids shown in cross-sectional studies and lead to the hypothesis that selenium and lipid levels share common biological pathways that need to be elucidated in mechanistic studies.

Zinc and smoking habits in the setting of hypertension in a Spanish populations.

The objective of this study was to evaluate the relationship between trace and toxic amounts of zinc (Zn) in biological samples (blood and urine) and the smoking habits of hypertensive patients and healthy control subjects in Valladolid (Spain). In order to compare biological samples, the concentrations of these samples were measured using inductively coupled plasma mass spectrometry. The limits of detection for Zn in blood plasma ranged between 4.22 and 17.34 µmol l(-1) and were <0.08 µmol g(-1) creatinine in urine. The results of this study indicate that the highest mean values of serum Zn were found in non-hypertensive nonsmokers (13.39±4.35 µmol l(-1)), whereas the highest urine Zn values were observed in hypertensive nonsmokers (2.78±2.13 µmol l(-1)). Higher Zn serum/urine quotient levels were observed in non-hypertensive and nonsmoking women, whereas lower levels were noted in non-hypertensive and smoking women (P=0.012). This study identified a correlation between Zn serum/urine quotients and cotinine levels (a marker of smoking), a correlation that suggests that smoking lowers the Zn serum/urine quotient, which was lower in hypertensive subjects than in control subjects.

Plasma selenium levels and oxidative stress biomarkers: a gene-environment interaction population-based study.

The role of selenium exposure in preventing chronic disease is controversial, especially in selenium-repleted populations. At high concentrations, selenium exposure may increase oxidative stress. Studies evaluating the interaction of genetic variation in genes involved in oxidative stress pathways and selenium are scarce. We evaluated the cross-sectional association of plasma selenium concentrations with oxidative stress levels, measured as oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8-oxo-7,8-dihydroguanine (8-oxo-dG) in urine, and the interacting role of genetic variation in oxidative stress candidate genes, in a representative sample of 1445 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.76 µg/L. In fully adjusted models the geometric mean ratios for oxidative stress biomarker levels comparing the highest to the lowest quintiles of plasma selenium levels were 0.61 (0.50-0.76) for GSSG/GSH, 0.89 (0.79-1.00) for MDA, and 1.06 (0.96-1.18) for 8-oxo-dG. We observed nonlinear dose-responses of selenium exposure and oxidative stress biomarkers, with plasma selenium concentrations above ~110 µg/L being positively associated with 8-oxo-dG, but inversely associated with GSSG/GSH and MDA. In addition, we identified potential risk genotypes associated with increased levels of oxidative stress markers with high selenium levels. Our findings support that high selenium levels increase oxidative stress in some biological processes. More studies are needed to disentangle the complexity of selenium biology and the relevance of potential gene-selenium interactions in relation to health outcomes in human populations.

Effects of similarity on environmental context cueing.

Three experiments examined the prediction that context cues which are similar to study contexts can facilitate episodic recall, even if those cues are never seen before the recall test. Environmental context cueing effects have typically produced such small effect sizes that influences of moderating factors, such as the similarity between encoding and retrieval contexts, would be difficult to observe experimentally. Videos of environmental contexts, however, can be used to produce powerful context-dependent memory effects, particularly when only one memory target is associated with each video context, intentional item-context encoding is encouraged, and free recall tests are used. Experiment 1 showed that a not previously viewed video of the study context provided an effective recall cue, although it was not as effective as the originally viewed video context. Experiments 2 and 3 showed that videos of environments that were conceptually similar to encoding contexts (e.g., both were videos of ball field games) also cued recall, but not as well if the encoding contexts were given specific labels (e.g., "home run") incompatible with test contexts (e.g., a soccer scene). A fourth experiment that used incidental item-context encoding showed that video context reinstatement has a robust effect on paired associate memory, indicating that the video context reinstatement effect does not depend on interactive item-context encoding or free recall testing.

Video context-dependent recall.

In two experiments, we used an effective new method for experimentally manipulating local and global contexts to examine context-dependent recall. The method included video-recorded scenes of real environments, with target words superimposed over the scenes. In Experiment 1, we used a within-subjects manipulation of video contexts and compared the effects of reinstatement of a global context (15 words per context) with effects of less overloaded context cues (1 and 3 words per context) on recall. The size of the reinstatement effects in Experiment 1 show how potently video contexts can cue recall. A strong effect of cue overload was also found; reinstatement effects were smaller, but still quite robust, in the 15 words per context condition. The powerful reinstatement effect was replicated for local contexts in Experiment 2, which included a no-contexts-reinstated group, a control condition used to determine whether reinstatement of half of the cues caused biased output interference for uncued targets. The video context method is a potent way to investigate context-dependent memory.

Distinctive items are salient during encoding: delayed judgements of learning predict the isolation effect.

Three experiments examined the role of salience in predicting superior memory for incongruent or odd items (the isolation effect). We tested the hypothesis that encoding salience emerges over the course of the encoding episode and predicts the isolation effect. In Experiment 1 participants studied lists of unrelated items and lists of categorized items containing an isolated item (from a different semantic category) that was presented either early or late in the list. Participants made delayed judgements of learning (JOLs) for studied items and were then given a free recall test. Results showed that participants had superior recall for the isolated items regardless of their list position and that delayed JOLs predicted this effect for both early and late isolation conditions. Experiment 2 replicated this delayed JOL effect using a different isolation paradigm that used only a single study list. Experiment 3 examined the specific mechanism by which isolated items become salient over the course of encoding and demonstrated that isolated items become salient as knowledge of the list structure unfolds. Results from these studies suggest that isolated items become salient over the course of the study episode, and that this salience predicts the isolation effect in memory.

[Tuberculosis pathology attended in emergency through the analysis of the hospital discharges MBDS in the West Valladolid Area, Spain (2002-2006)]. / Patología tuberculosa atendida en urgencias a través del análisis del CMBD de hospitalización en el área de Valladolid Oeste (2002-2006).

BACKGROUND: Tuberculosis (TB) continues to be an important health problem, in many cases the Hospital Emergency Services (HES) are the first contact of the patients with the sanitary system, there is not known the impact of this disease in the above mentioned services. The objectives of this study are to know the importance of TB in HES and to describe hospital discharges (MBDS) with TB diagnosis and if they had already been diagnosed in the HES. METHODS: A retrospective descriptive study of discharges with TB diagnosis in the hospital ward and in the HES of a tertiary care university hospital from 2002 to 2006. The Diagnostic concordance study and analysis of variables according to two groups: Coincidents (discharge with TB diagnosis in the HES and in the MBDS) and Only in the MBDS. Calculate statisticals of central tendency and dispersal for the quantitative variables and proportions and tables of contingency with application of the test chi(2) for the qualitative ones. RESULTS: Of the 172 (0.26%) emergencies admitted which were hospital discharges with Tb diagnosis, 61(35.5%) came in HES. The diagnostic concordance was 0.43(43.66%). The hospital discharges with Tb diagnosis (coincidents) changed from 47 (17) in 2002 to 21(5) in 2006. The 65.1% (68.9% in coincidents) were males. As regards age groups (coincidents%): 0-14: 6 (33.3%), 15-45: 81(47%), 46-65: 46(28.7%), 65: 39(19.7%); excluding group 0-14, p=0.009. Respiratory location (coincidents): 110 (50) and positive direct examination of smears for acid-fast bacilli (coincidents): 87 (43). Between well-known risk factors immigration stands out (p=0.001). CONCLUSIONS: The discharges with TB diagnosis declined during the period studied. The diagnostic concordance in the HES was moderate. We would have to insist more on seniors, and in people with well-known risk factors. In the HES the respiratory TB is also the most frequent being the direct examination of smears for acid-fast bacilli the principal diagnostic method.

Patología tuberculosa atendida en urgencias a través del análisis del CMBD de hospitalización en el área de Valladolid Oeste (2002-2006) / Tuberculosis pathology attended in emergency through the analysis of the hospital discharges MBDS in the West Valladolid Area, Spain (2002-2006)

Fundamento: La Tuberculosis (TB) sigue siendo un problema de salud importante, en muchos casos los servicios de urgencias hospitalarios (SUH) constituyen el primer contacto de los pacientes con el sistema sanitario. Se desconoce el impacto de esta enfermedad en dichos servicios. Los objetivos de este estudio son conocer la importancia de la TB en los SUH y describir las altas hospitalarias (CMBD) con diagnóstico de TB, y cuáles ya habían sido diagnosticadas en el SUH. Métodos: Estudio descriptivo retrospectivo de las altas con TB en hospitalización y en el SUH de un hospital terciario universitario entre 2002-2006. Estudio de concordancia diagnóstica y análisis de variables según dos grupos: Coincidentes (Alta con TB en el SUH y en el CMBD) y Sólo en el CMBD. Se calculan estadísticos de tendencia central y dispersión para las variables cuantitativas, y proporciones y elaboración de tablas de contingencia con aplicación del test chi2 para las cualitativas. Resultados: De las 172 (0,26%) urgencias ingresadas que fueron altas hospitalarias con TB, 61 (35,5%) procedían del SUH. La concordancia diagnóstica fue 0,43 (43,46%). Las altas hospitalarias con TB (coincidentes) pasaron de 47 (17) en 2002 a 21 (5) en 2006. El 65,1% (68,9% en coincidentes) fueron varones. Por grupos de edad (coincidentes%): 0-14: 6(33,3%), 15- 45: 81(47%), 46-65: 46(28,7%), >65: 39(19,7%); excluyendo de 0-14, p=0,009. Localización respiratoria (coincidentes): 110 (50) y baciloscopia positiva (coincidentes): 87 (43). Entre los factores de riesgo conocidos destaca la inmigración (p=0,001). Conclusiones: Las altas con TB descendieron durante el periodo estudiado. La concordancia diagnostica en el SUH fue moderada. Habría que incidir más en personas de mayor edad, y en aquéllas con factores de riesgo conocidos. En el SUH la TB respiratoria es también la más frecuente siendo la baciloscopia el método diagnóstico principal (AU)

Background: Tuberculosis (TB) continues to be an important health problem, in many cases the Hospital Emergency Services (HES) are the first contact of the patients with the sanitary system, there is not known the impact of this disease in the above mentioned services. The objectives of this study are to know the importance of TB in HES and to describe hospital discharges (MBDS) with TB diagnosis and if they had already been diagnosed in the HES. Methods: A retrospective descriptive study of discharges with TB diagnosis in the hospital ward and in the HES of a tertiary care university hospital from 2002 to 2006. The Diagnostic concordance study and analysis of variables according to two groups: Coincidents (discharge with TB diagnosis in the HES and in the MBDS) and Only in the MBDS. Calculate statisticals of central tendency and dispersal for the quantitative variables and proportions and tables of contingency with application of the test chi2 for the qualitative ones. Results: Of the 172 (0.26%) emergencies admitted which were hospital discharges with Tb diagnosis, 61(35.5%) came in HES. The diagnostic concordance was 0.43(43.66%). The hospital discharges with Tb diagnosis (coincidents) changed from 47 (17) in 2002 to 21(5) in 2006. The 65.1% (68.9% in coincidents) were males. As regards age groups (coincidents%): 0-14: 6 (33.3%), 15-45: 81(47%), 46-65: 46(28.7%), >65: 39(19.7%); excluding group 0-14, p=0.009. Respiratory location (coincidents): 110 (50) and positive direct examination of smears for acid-fast bacilli (coincidents): 87 (43). Between well-known risk factors immigration stands out (p=0.001). Conclusions: The discharges with TB diagnosis declined during the period studied. The diagnostic concordance in the HES was moderate. We would have to insist more on seniors, and in people with well-known risk factors. In the HES the respiratory TB is also the most frequent being the direct examination of smears for acid-fast bacilli the principal diagnostic method (AU)

The influence of age on memory for distinctive events.

We examined whether memory for distinctive events is influenced by aging. To do so, we used a semantic isolation paradigm in which people show superior memory for a word when it is presented in a list of items from a different semantic category (e.g., the word table is presented in a list of all bird exemplars) as compared with when the same word (table) is presented in a list of unrelated words. Results showed that both younger and older adults demonstrated an isolation effect in memory, although older adults showed a numerically smaller isolation effect than did younger adults. Results suggest that in contrast with previous findings (Cimbalo & Brink, 1982), older adults can take advantage of this type of distinctiveness to aid memory performance.