Bone marrow adipose tissue (BMAT) is associated with low bone mass, although the functional consequences for skeletal maintenance of increased BMAT are currently unclear. BMAT might have a role in systemic energy metabolism, and could be an energy source as well as an endocrine organ for neighboring bone cells, releasing cytokines, adipokines and free fatty acids into the bone marrow microenvironment. The aim of the present report was to compare the fatty acid composition in the bone marrow supernatant fluid (BMSF) and blood plasma of postmenopausal women women (65 to 80 years old). BMSF was obtained after spinning the aspirated bone marrow samples; donors were classified as control, osteopenic or osteoporotic after dual-energy X-ray absorptiometry. Total lipids from human bone marrow fluid and plasma were extracted, converted to the corresponding methyl esters, and finally analyzed by a gas chromatographer coupled with a mass spectrometer. Results showed that fatty acid composition in BMSF was dynamic and distinct from blood plasma, implying significance in the locally produced lipids. The fatty acid composition in the BMSF was enriched in saturated fatty acid and decreased in unsaturated fatty acids as compared to blood plasma, but this relationship switched in women who suffered a hip fracture. On the other hand, there was no relationship between BMSF and bone mineral density. In conclusion, lipid composition of BMSF is distinct from the circulatory compartment, most likely reflecting the energy needs of the marrow compartment.

The function of marrow adipocytes and their origin has not been defined although considerable research has centered on their presence in certain conditions, such as osteoporosis. Less work has focused on the qualitative aspects of marrow fat. Bone marrow serum is composed of multiple nutrients that almost certainly relate to functional aspects of the niche. Previous studies using non-invasive techniques have shown that osteoporotic individuals have more marrow fat and that the ratio of saturated: unsaturated fatty acid is high. We recently reported that bone marrow sera from osteoporotic patients with fracture showed a switch toward decreased content of total saturated versus unsaturated fatty acids, compared to patients without fracture highlighting a dynamic relationship between the composition of fatty acids in the bone microenvironment and the metabolic requirements of cells. The relative distribution of fatty acids differed considerably from that in the serum providing further evidence that energy utilization is high and that marrow adipocytes may contribute to this pool. Whether these lipids can affect osteoblast function in a positive or negative manner is still not certain but will require further investigation.

Use of oral contraceptives is a recognised but infrequent cause of chorea. This type of chorea has usually been considered a reactivation of Sydenham's chorea by an unknown mechanism. A patient developed a chorea triggered by the use of oral contraceptives with no definite evidence of previous Sydenham's chorea or recent streptoccocal infections. However, the patient had positive anti-basal ganglia antibodies, which supports an immunological basis for the pathophysiology of this chorea.

No abstract

Este trabajo fue recibido el 21 de Julio de 2015 y aceptado para ser publicado el 23 de Octubre de 2015. Prevalencia de anemia y estado nutricional de escolares del área periurbana de Sucre, BoliviaAnemia prevalence and nutritional status in children of a suburban area of Sucre, Bolivia Rev Chil Nutr Vol. 42, Nº4, Diciembre 2015 INTRODUCCIÓN El hierro es un oligoelemento mineral indispensable para el humano, participa en procesos biológicos, tales como el transporte y almacenamiento de oxígeno, y en la síntesis de hemoglobina (1). Además, es fundamental para el funcionamiento apropiado de numerosas enzimas, por lo que su defi ciencia puede afectar múltiples funciones metabólicas incluida la respuesta inmunológica (2).La anemia por defi ciencia de hierro es una enfermedad nutricional de alta prevalencia en todo el mundo, especialmente en países en vías de desarrollo (3). La OMS estima que son anémicos alrededor de 39% de niños menores de 5 años, 48% de niños de 5 a 14 años, 42% de todas las mujeres y 52% de las mujeres embarazadas de los países en desarrollo (3-4). En Bolivia, la defi ciencia de hierro constituye el trastorno nutricional más común y la principal causa de anemia, con una prevalencia general de anemia del 56% (5), alcanzando un 86,6% de niños entre 6 a 23 meses de edad (6) y 34.7% en escolares (7). Actualmente, Bolivia se encuentra entre los países con los porcentajes más elevados de desnutrición crónica (8), tres de cada diez niños menores de 5 años tienen talla baja para la edad, tasa nacional que enmascara