[Airway metaplasia related to smoking and environmental pollution through sputum]. / Metaplasia de vías aéreas asociada a tabaquismo y contaminación ambiental mediante esputo.

BACKGROUND: Both environmental pollution and smoking affect the respiratory epithelium, causing cellular adaptation changes. Therefore, this work explores the presence of metaplasia in smokers compared with non-smokers from Mexico City. METHODS: A prospective cohort study was performed. The sample was performed through a home interview covering the five Mexico City zones delimited to the study and monitoring of air quality. We searched metaplastic cells and inflammation in sputum cytology stained with Papanicolaou technique, and we assessed the air quality in Mexico City. We calculated relative risk (RR) and attributable risk (AR) in relation to the presence of metaplasia and smoking. RESULTS: We performed 1897 home interviews obtaining a final sample of 30 participants. There were no significant differences between smokers and non-smokers with the presence of metaplastic cells (p = 0.269), although the association of metaplastic cells and inflammation showed a significant difference in the non-smokers group (p = 0.010). The RR in association with the presence of metaplasia in sputum cytology and smoking was 1.6, and the RA was 0.2. CONCLUSIONS: The air quality in this city has led the population to undergo changes of cellular adaptation in the respiratory epithelium by the simple fact of being exposed to environmental pollution. Metaplastic changes in non-smokers suggest strongly that pollution causes the same effect as smoking.

INTRODUCCIÓN: la contaminación ambiental y el tabaquismo afectan el epitelio respiratorio y provocan cambios de adaptación celular. Se buscó explorar la presencia de metaplasias en sujetos fumadores y no fumadores, residentes de la Ciudad de México (CDMX) y expuestos desde su nacimiento a la contaminación ambiental de esta ciudad. MÉTODOS: estudio de cohorte prospectivo cuya muestra se seleccionó con base en entrevistas a domicilio que cubrieron las cinco zonas de la CDMX en las que se monitorea la calidad del aire. Se buscaron células con cambios metaplásicos e inflamatorios en citologías de esputo teñidas con la técnica Papanicolaou, además de valorar la calidad del aire de la CDMX. Se calculó riesgo relativo (RR) y riesgo atribuible (RA) en relación con la presencia de metaplasias y tabaquismo. RESULTADOS: se realizaron 1897 entrevistas; se obtuvo una muestra final de 30 personas en las que no hubo diferencias significativas entre sujetos con hábito tabáquico y no fumadores en cuanto a presencia de células metaplásicas (p = 0.269); la relación de células metaplásicas e inflamación tuvo una diferencia significativa en el grupo de no fumadores (p = 0.010). El RR en relación con la presencia de metaplasias en las citologías de esputo y tabaquismo fue de 1.6, y el RA fue de 0.2. CONCLUSIONES: la calidad del aire en la CDMX ha llevado a la población a sufrir cambios de adaptación celular en el epitelio respiratorio solo por estar expuestos a la contaminación ambiental. Los cambios metaplásicos en los no fumadores indican que la contaminación causa el mismo efecto que fumar.

Mexneurin is a novel precursor of peptides in the central nervous system of rodents.

Endomorphins (EMs) have been proposed as the endogenous ligand agonists of the µ-opioid receptor; however, no propeptide precursor protein for EMs has been identified. Here, to identify the presumed precursor of EMs, we designed an immunoscreening assay using specific affinity-purified rabbit antisera raised against synthetic EMs in a whole-mouse brain cDNA library. Following this approach, we identify a DNA sequence encoding a protein precursor, which we name proMexneurin, that contains three different peptide sequences: Mexneurin-1 (an EM-like peptide), Mexneurin-2, and Mexneurin-3, a peptide which appears to be unrelated to EMs. RT-PCR analysis and in situ hybridization reveal a widespread distribution of proMexneurin mRNA throughout the mouse brain. Both Mexneurin-1 and Mexneurin-3 peptides display biological activities in the mouse CNS.