Efecto regional, de la edad y el sexo en la espectroscopia por resonancia magnética cerebral / Regional effects of age and sex in magnetic resonance spectroscopy

Objetivo. Estudiar con espectroscopia univóxel por resonancia magnética (1,5T) el efecto regional, de la edad y el sexo en las ratios metabólicas del lóbulo temporal medial, la región cerebral posteromedial (RPM) y el lóbulo frontal. Material y métodos. Estudiamos 31 personas sanas mayores de 55 años (grupo 1) y 20 menores de 30 años (grupo 2) con espectroscopia univóxel en el lóbulo frontal izquierdo, el lóbulo temporal medial izquierdo y la RPM, especialmente afectadas por las enfermedades neurodegenerativas. Se calcularon las ratios NAA/Cr, NAA/Cho, NAA/mI, Cho/Cr, y mI/Cr, de cada vóxel. En cada grupo se compararon regionalmente las ratios metabólicas, y se estudió la correlación ratio-edad dentro de sus rangos de edad. Finalmente, se analizaron las diferencias de las ratios metabólicas entre grupos y entre sexos. Resultados. En el grupo 1, las ratios Cho/Cr frontal y NAA/mI temporal se correlacionaron negativamente con la edad. En el grupo 2, las correlaciones con la edad fueron negativas para las ratios temporales mI/Cr y NAA/Cho, y positiva para la NAA/mI temporal. En el lóbulo frontal y la RPM, las ratios NAA/Cr, NAA/Cho y NAA/mI fueron menores en el grupo 1 (P<=0,003). Las ratios Cho/Cr y mI/Cr nunca mostraron diferencias entre grupos. Los valores de las ratios difirieron regionalmente en todos los casos (P<0,001). NAA/Cr y Cho/Cr en el lóbulo temporal medial fueron mayores en las mujeres (P<=0,034). Conclusiones. Cuando se utilice la espectroscopia univóxel por resonancia magnética, en particular en las enfermedades neurodegenerativas, siempre deben considerarse las variaciones inducidas por la región, la edad y el sexo (AU)

Objective. To determine the regional effects of age and sex on the metabolic ratios obtained in the medial temporal lobe, the posteromedial region, and the frontal lobe at 1.5T single-voxel magnetic resonance spectroscopy. Material and methods. We used single-voxel magnetic resonance spectroscopy to study the areas of the brain most affected in neurodegenerative disease (the left frontal lobe, the left medial temporal lobe, and the posteromedial region) in 31 healthy subjects older than 55 years of age (group 1) and in 20 healthy subjects under 30 years of age (group 2). We calculated the following ratios for each voxel: N-acetyl-aspartate/creatine-phosphocreatine (NAA/Cr), N-acetyl-aspartate/choline (NAA/Cho), N-acetyl-aspartate /myoinositol (NAA/mI), choline/creatine-phosphocreatine (Cho/Cr), and myoinositol (mI/Cr). We compared the metabolic ratios in each region in each group and the correlation between age and the ratios within age ranges. Finally, we analyzed the differences in the metabolic ratios between groups and between sexes. Results. In group 1, we found negative correlations between age and Cho/Cr in the frontal region and NAA/mI in the temporal region. In group 2, we found negative correlations between age and mI/Cr and NAA/Cho in the temporal region as well as a positive correlation between age and NAA/mI in the temporal region. In the frontal lobe and the posteromedial region, NAA/Cr, NAA/Cho, and NAA/mI were lower in group 1 (P<=0.003). No differences between groups were seen in Cho/Cr or mI/Cr. The values of the ratios differed regionally in all cases (P<0.001). In the temporal lobe, NAA/Cr and Cho/Cr were higher in women (P<=0.034). Conclusions. When using single-voxel magnetic resonance spectroscopy, especially in patients with neurodegenerative disease, variations due to region, age, and sex should always be taken into account (AU)

[Multicenter study of the variability and adequacy of antimicrobial therapy for community-acquired pneumonia in adults] / Estudio multicéntrico de variabilidad e idoneidad de la prescripción antibiótica en la neumonía adquirida en la comunidad del adulto.

We performed a study to evaluate the variability and adequacy of prescribing antibiotics in community-acquired pneumonia (CAP) in 10 Spanish hospitals. We studied 452 patients with CAP. Initial empirical administration of antibiotics was prescribed in 90.7% of the cases, 82.5% as monotherapy. Macrolides and third and second generation cephalosporins were the most widely used groups of antibiotics. Penicillin and amoxicillin were only prescribed in 1.7% of the patients. A significant variability between hospitals was observed. Reference patterns for the use of antibiotics in CAP were devised by a panel of experts. According to the recommendations of this panel, 29% of the total prescriptions were not adequate, with this percentage reaching 65% in outpatients older than 65 years or with comorbidity. This was mainly due to the fact that monotherapy with erythromycin, which was considered inadequate, was the most widely prescribed treatment.