Abstract
Prochlorococcus and Synechococcus are the two most abundant photosynthetic organisms on Earth, with a strong influence on the biogeochemical carbon and nitrogen cycles. Early reports ...demonstrated the streamlining of regulatory mechanisms in nitrogen metabolism and the removal of genes not strictly essential. The availability of a large series of genomes, and the utilization of latest generation molecular techniques have allowed elucidating the main mechanisms developed by marine picocyanobacteria to adapt to the environments where they thrive, with a particular interest in the strains inhabiting oligotrophic oceans. Given that nitrogen is often limited in those environments, a series of studies have explored the strategies utilized by Prochlorococcus and Synechococcus to exploit the low concentrations of nitrogen-containing molecules available in large areas of the oceans. These strategies include the reduction in the GC and the cellular protein contents; the utilization of truncated proteins; a reduced average amount of N in the proteome; the development of metabolic mechanisms to perceive and utilize nanomolar nitrate concentrations; and the reduced responsiveness of key molecular regulatory systems such as NtcA to 2-oxoglutarate. These findings are in sharp contrast with the large body of knowledge obtained in freshwater cyanobacteria. We will outline the main discoveries, stressing their relevance to the ecological success of these important microorganisms.
Adaptations of N metabolism in marine picocyanobacteria.
Marine picocyanobacteria of the Prochlorococcus and Synechococcus genera have been longtime considered as autotrophic organisms. However, compelling evidence published over the last 15 years shows ...that these organisms can use different organic compounds containing key elements to survive in oligotrophic oceans, such as N (amino acids, amino sugars), S (dimethylsulfoniopropionate, DMSP), or P (ATP). Furthermore, marine picocyanobacteria can also take up glucose and use it as a source of carbon and energy, despite the fact that this compound is devoid of limiting elements and can also be synthesized by using standard metabolic pathways. This review will outline the main findings suggesting mixotrophy in the marine picocyanobacteria Prochlorococcus and Synechococcus, and its ecological relevance for these important primary producers.
Coronary heart disease prevention in the primary care setting, where time is extremely limited, requires valid instruments that efficiently screen for unhealthy lifestyle habits. Identification of ...the individuals who would most benefit from dietary intervention is particularly important in this context. We used dietary intake data derived from a full-length food frequency questionnaire to simulate responses to our previously validated short dietary quality screener. We determined the prospective association of the resulting diet-quality index (DQI) with changes in anthropometric and cardiometabolic risk variables in 2181 men and women in a 10-year follow-up. Multiple linear regression analyses revealed that a higher DQI score at baseline related directly (P=0.002) to high-density lipoprotein cholesterol (HDL-C) and inversely (P<0.016) to waist circumference (WC), triacylglycerides (TG), the TG to HDL-C ratio and the total cholesterol to HDL-C ratio at follow-up. A low DQI score is predictive for an increase in WC and the development of an unfavourable cardiometabolic profile.
We study the aerodynamics of a blunt-based body with rear flexibly-hinged rigid flaps, subject to a turbulent flow of Reynolds number Re=12000, under aligned and cross flow conditions with yaw angle ...β=0° and β=4°. To that aim, different values of the equivalent torsional stiffness are considered, to cover the range of reduced velocity U∗=(0,3.48 in water tank experiments. The effect of the angular deflection of plates on the drag and near wake flow is analyzed, experimentally and numerically. The results show that, in the range of U∗ herein considered, the plates undergo an inwards quasi-static, self-adaptive deflection, which is symmetric for yaw angles β=0° and asymmetric for β=4°. In particular, the plates feature small mean deformation angles for values of U∗<1, whereas a sharp and monotonic increase of such deflection occurs for U∗>1, i.e. for lower values of the hinge’s stiffness, with an asymptotic trend towards the larger values of U∗. A critical value of reduced velocity of U∗≃0.96 is obtained as the instability threshold above which plates depart from their initial equilibrium position. The progressive streamlining of the trailing edge translates into significant reductions of the associated mean drag coefficients. Thus, reductions close to 19% with respect to reference static plates configurations are obtained for the most flexible case of U∗=3.48 for both β=0° and β=4°. A close inspection of the near wake reveals that the inwards progressive mean displacement of the plates yields a reduction in the recirculation bubble size. A symmetric evolution of the recirculating bubble is observed for β=0°, whereas the bubble becomes asymmetric for β=4°, with a larger leeward clockwise vortex. In both cases, the drag coefficient is shown to vary linearly with the global aspect ratio of the recirculating bubble. The analysis of the numerical results shows that the reduced extension of the recirculating bubble significantly alters the formation length and intensity of the eddies size and associated pressure. It is observed that despite the local pressure decrease in the vortices shed from the trailing edges, the plates self adaption reduces their size and prevents the eddies from entering the cavity, thus, creating a dead flow region with a consequent pressure increase at the body base.
BACKGROUNDThe effect of primary androgen deprivation therapy (ADT) in patients with localized prostate cancer (PCa) has not been well documented. The objective of the present study was to analyze the ...outcome of tumors treated with ADT as primary therapy in the Spanish Prostate Cancer Registry (19.4% of the series). PATIENTS AND METHODSPatients were classified in three groups: 1) with low/intermediate risk clinically localized tumors; 2) with high risk and locally advanced (T3-4) tumors; 3) with metastatic tumors. Time to castration resistance and overall cancer-specific survival were analyzed. In non-metastatic tumors, survivals in patients treated with ADT were compared with data from patients who underwent local treatments from the Spanish Prostate Cancer Registry. RESULTS703 cases were analyzed. There were significant differences in the time to castration resistance, which was lower in the group of metastatic tumors. During follow-up, there were 179 deaths (25.5%) of which 89 (12.6%) were due to PCa. After 3 years of ADT, only 14.6% of patients in group 1 had died (1% due to PCa), 20.5% in group 2 and 46.8% in group 3 (9.2% and 31.3% due to PCa, respectively). Cancer-specific survival was significantly worse in group 1 using ADT than radical prostatectomy or radiotherapy. In high-risk and locally advanced tumors, ADT also had a lower cancer-specific survival than local treatments. CONCLUSIONA longer time until the castration resistance was observed in patients with well- and intermediate-risk localized tumors treated with ADT. Patients with metastatic tumors showed the shortest time to castration resistance.
Atrial fibrillation (AF) is the most common type of arrhythmia. The purpose of this study was to determine the prevalence of atrial fibrillation and its relationship with cardiovascular risk factors ...in Spain.
Cross-sectional study based on a grouped analysis of 17,291 randomized individuals recruited in 6 population studies.
The prevalence of atrial fibrillation was 1.5% (95% CI:1.3-1.7%). Men had a greater prevalence of the disease than women (1.9 vs. 1.1%, respectively). The prevalence of atrial fibrillation progressively increased with age: 0.05% for patients younger than 45 years, 0.5% for those between 45-59 years of age, 2.3% for those between 60-74 years of age and 6.3% for those older than 75 years. The percentage of individuals who were underwent anticoagulant treatment was 74.3%. The risk factors significantly associated with arrhythmia were an age older than 60 years (odds ratio OR: 7.6; 95% CI: 5.1-11.2), the male sex (OR:1.8; 95% CI: 1.4-2.4), arterial hypertension (OR:1.6; 95% CI: 1.2-2.1), obesity (OR:1.5; 95% CI:1.2-2.1) and a history of coronary artery disease (OR:1.9; 95% CI: 1.3-3.0).
Atrial fibrillation is a common disease in elderly individuals, while its prevalence is low in individuals younger than 60 years. Most individuals with atrial fibrillation were on anticoagulant treatment. The risk factors for this type of arrhythmia are age, the male sex, hypertension, obesity and a history of coronary artery disease.
Resumen Introducción y objetivos Determinar la prevalencia de enfermedad arterial periférica mediante el índice tobillo-brazo y evaluar los factores de riesgo, clínicos y diagnósticos asociados. ...Métodos Estudio transversal realizado entre 2007 y 2009, con muestra aleatoria de 2.833 sujetos entre 25 y 79 años representativa del área de salud de Don Benito (Badajoz). Se consideró diagnóstico de enfermedad arterial periférica un índice tobillo-brazo < 0,90. Se utilizó el cuestionario de Edimburgo para identificar formas sintomáticas. Se evaluaron las recomendaciones actuales de cribado, los cambios del riesgo coronario estimado conseguidos con su uso y la asociación con los factores de riesgo. Resultados La prevalencia de enfermedad arterial periférica fue del 3,7% (intervalo de confianza del 95%, 3,0-4,5%); el 5,0% (3,9-6,3%) en varones y el 2,6% (1,8-3,5%) en mujeres (p = 0,001). Las prevalencias acumuladas a partir de 50, 60 y 70 años fueron del 6,2, el 9,1 y el 13,1% respectivamente. La enfermedad era sintomática en el 13,3% (6,8-19,8%) de los casos. Las recomendaciones actuales de cribado no detectaron al 29,6% de los enfermos asintomáticos. El uso del índice aumentó el 32,7% los casos de riesgo coronario alto. Se halló asociación positiva de la enfermedad con edad, tabaquismo, hipercolesterolemia, sedentarismo, microalbuminuria y enfermedad cardiovascular, y negativa con el consumo de alcohol. Conclusiones El uso del índice tobillo-brazo es aconsejable para el diagnóstico de esta enfermedad, dada la baja prevalencia de formas sintomáticas y su capacidad para cambiar el riesgo coronario estimado. Se debería adaptar los grupos de cribado a la población española. Tabaquismo e hipercolesterolemia son los principales factores de riesgo.
The effect of primary androgen deprivation therapy (ADT) in patients with localized prostate cancer (PCa) has not been well documented. The objective of the present study was to analyze the outcome ...of tumors treated with ADT as primary therapy in the Spanish Prostate Cancer Registry (19.4% of the series).
Patients were classified in three groups: (1) with low/intermediate risk clinically localized tumors; (2) with high risk and locally advanced (T3-4) tumors; (3) with metastatic tumors. Time to castration resistance and overall cancer-specific survival were analyzed. In non-metastatic tumors, survivals in patients treated with ADT were compared with data from patients who underwent local treatments from the Spanish Prostate Cancer Registry.
703 cases were analyzed. There were significant differences in the time to castration resistance, which was lower in the group of metastatic tumors. During follow-up, there were 179 deaths (25.5%) of which 89 (12.6%) were due to PCa. After 3 years of ADT, only 14.6% of patients in group 1 had died (1% due to PCa), 20.5% in group 2 and 46.8% in group 3 (9.2% and 31.3% due to PCa, respectively). Cancer-specific survival was significantly worse in group 1 using ADT than radical prostatectomy or radiotherapy. In high-risk and locally advanced tumors, ADT also had a lower cancer-specific survival than local treatments.
A longer time until the castration resistance was observed in patients with well- and intermediate-risk localized tumors treated with ADT. Patients with metastatic tumors showed the shortest time to castration resistance.
Antecedentes El efecto del tratamiento primario de privación androgénica (TPA) en pacientes con cáncer de próstata (CP) localizado no está bien documentado. El objetivo del presente estudio fue analizar el resultado de los tumores tratados con TPA como terapia primaria en el Registro Español de Cáncer de Próstata (19,4% de la serie).
Los pacientes se clasificaron en tres grupos: 1) con tumores clínicamente localizados de riesgo bajo/intermedio; 2) con tumores de alto riesgo y localmente avanzados (T3-4); 3) con tumores metastásicos. Se analizó el tiempo hasta la resistencia a la castración y la supervivencia general específica del cáncer. En tumores no metastásicos, las supervivencias en pacientes tratados con TPA se compararon con los datos de pacientes que recibieron tratamientos locales del Registro Español de Cáncer de Próstata.
Se analizaron 703 casos. Hubo diferencias significativas en el tiempo de resistencia a la castración, que fue menor en el grupo de tumores metastásicos. Durante el seguimiento hubo 179 muertes (25,5%), de las cuales 89 (12,6%) se debieron a CP. Después de 3 años de TPA, solo el 14,6% de los pacientes en el grupo 1 fallecieron (1% debido a CP), el 20,5% en el grupo 2 y el 46,8% en el grupo 3 (9,2% y 31,3% debido a CP, respectivamente). La supervivencia específica del cáncer fue significativamente peor en el grupo 1 tratado con TPA que en el que recibió prostatectomía radical o radioterapia. En los tumores de alto riesgo y localmente avanzados, la TPA también tuvo una menor supervivencia específica al cáncer que los tratamientos locales.
Se observó un tiempo más largo hasta la resistencia a la castración en pacientes con tumores localizados de riesgo intermedio y bien tratados con TPA. Los pacientes con tumores metastásicos mostraron el menor tiempo hasta la resistencia a la castración.
Prochlorococcus is a marine cyanobacterium responsible for a significant part of global primary production as well as being one of the most abundant organisms on Earth. Protein turnover is an ...essential and poorly understood aspect of the cyanobacterial response to environmental stresses. In the present work, cultures of the SS120 and MIT9313 strains were subjected to several conditions, and quantitative real time RT-PCR was used to measure changes in the expression of genes encoding three representative ATP-dependent proteases. We found common responses to conditions such as aging. However, the expression pattern under nutrient starvation was strikingly different in the two strains, probably reflecting the different regulatory backgrounds of the two ecotypes here studied.
Orthostatic hypotension (OH) is a common disorder, and possibly underdiagnosed. In the elderly, OH has been considered a common cause of falls, fractures, and fear of falling. Its prevalence ...increases with age, probably related to the number of drug treatments, decreased fluid intake, and the progressive dysfunction of the autonomic nervous system.
To evaluate the prevalence of OH in a non-institutionalised population ≥80 years, according to different criteria based on sequential measurements taken at minute 0, 1, 3 and 5 of standing.
A diagnostic accuracy study using an oscillometric device.
Convenience sampling of 176 people ≥80 years attended in an urban Primary Health Care Centre.
Supine and standing blood pressure (BP) measurements, at minutes 0, 1, 3 and 5 using the OMRON 705-CP blood pressure device. OH definition: decrease ≥20mmHg in systolic BP (SBP) and/or ≥10mmHg in diastolic BP (DBP).
Mean age (Standard Deviation) was 85.2 (3.7) years, and 60.2% were women. Prevalence of OH: 30.7% at minute 0; 19.3% at minute 1; 18.2% at minute 3; and 20.5% at minute 5. Age, sedentary life, smoking, diabetes and SBP values were significantly associated with a greater BP decrease at minute 0.
A third of the sample had OH, with a maximum prevalence at minute 0. From a clinical point of view, it is suggested that the definition of OH is prioritized according to the BP at minute 0.
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