Exposición a polvo de harina de trigo en panaderías de la Región Metropolitana / Bakers' exposure to wheat flour dust in Santiago, Chile

Wheat flour is a known sensitizer for humans. Bakers exposed to flour dust may develop occupational rhinitis and asthma. In Chile there is no current permissible limit for occupational exposure to wheat flour. To propose such a limit, 9 bakeries located in 6 districts of Santiago de Chile were evaluated, 6 bakeries were semi-industrial and 3 were small business. Twenty-eight environmental personal samples were obtained by standard sampling methods and they were analyzed at the Institute of Public Health of Chile. No significant differences were found (p = 0,2915, Kruskall-Wallis' test) between air concentrations of flour particles in the working environment of semi-industrial (geometric mean: MG = 0.88 mg/m³,geometric deviation: DEG = 2,68) and small business (MG = 1.39 mg/m³, DEG = 2,31). A permissible limit of wheat flour dust exposure is recommended.

Se conoce que la harina de trigo es un sensibilizador en seres humanos. Los panaderos expuestos a polvo de harina pueden desarrollar rinitis y asma ocupacional. En Chile actualmente no existe un límite permisible para la exposición ocupacional a polvo de harina. Con el objetivo de proponer un límite, fueron evaluadas 9 panaderías de 6 comunas de Santiago de Chile, de las cuales 6 fueron semi-industriales y 3 pequeñas. Un total de veintiocho muestras personales de aire fueron obtenidas según método estándar de muestreo y analizadas en el Instituto de Salud Pública de Chile. No se encontraron diferencias significativas (p = 0,2915, prueba de Kruskall-Wallis) en la concentración de partículas de harina en el ambiente de trabajo semi-industrial (media geométrica: MG = 0,88 mg/m³, desviación geométrica: DEG = 2,68) y en el de panaderías pequeñas (MG = 1,39 mg/m³, DEG = 2,31). En base a las observaciones realizadas se recomienda establecer un límite permisible de exposición para polvo de harina de trigo.

Progreso de la infección viral en mellizos hijos de madre infectada por el virus de la inmunodeficiencia humana / Progress of viral infection in twins borned from a human immunodeficiency virus infected mother

We studied the evolution of HIV-1 infection and immune response during six years in 2 twins born from an infected mother. The children had a continous progression of the infection, proved by CD4+ cell counts, serum anti-HIV antibodies, cultivable virus and proviral load. Now, both children are on antiviral treatment. The analysis of serum antibodies showed a different immune response in both children. One of them, developed higher levels of antibodies directed against viral proteins and synthetic peptides derived from their aminoacid sequence. In this child, the amount of cultivable virus increased less than in his twin. Nucleotide sequencing of a part of viral genoma, showed that the virus belonged to the B subtype, prevalent in America and Europe. The observed differences in viral sequences suggest a different selective pressure in both twins. This phenomenon could be related to the observed differences in immune response