RESUMO
In the present study an in vitro bilayer model system of the pulmonary alveolocapillary barrier was established to investigate the role of the microvascular endothelium on re-epithelialization. The model system, confluent monolayer cultures on opposing sides of a porous membrane, consisted of a human microvascular endothelial cell line (HPMEC-ST1.6R) and an alveolar type II like cell line (A549), stably expressing EGFP and mCherry, respectively. These fluorescent proteins allowed the real time assessment of the integrity of the monolayers and the automated analysis of the wound healing process after a scratch injury. The HPMECs significantly attenuated the speed of re-epithelialization, which was associated with the proximity to the A549 layer. Examination of cross-sectional transmission electron micrographs of the model system revealed protrusions through the membrane pores and close contact between the A549 cells and the HPMECs. Immunohistochemical analysis showed that these close contacts consisted of heterocellular gap-, tight- and adherens-junctions. Additional analysis, using a fluorescent probe to assess gap-junctional communication, revealed that the HPMECs and A549 cells were able to exchange the fluorophore, which could be abrogated by disrupting the gap junctions using connexin mimetic peptides. These data suggest that the pulmonary microvascular endothelium may impact the re-epithelialization process.
Assuntos
Lesão Pulmonar Aguda/patologia , Técnicas de Cultura de Células/métodos , Células Endoteliais/citologia , Alvéolos Pulmonares/irrigação sanguínea , Alvéolos Pulmonares/citologia , Mucosa Respiratória/irrigação sanguínea , Lesão Pulmonar Aguda/fisiopatologia , Linhagem Celular Tumoral , Técnicas de Cocultura , Células Endoteliais/patologia , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Alvéolos Pulmonares/patologia , Mucosa Respiratória/citologia , Mucosa Respiratória/patologiaRESUMO
We report a 13-month-old infant who accidentally ingested a tablet of 3, 4-methylenedioxymethamphetamine (MDMA) and was brought to the emergency department with tachycardia, seizures, mydriasis, and altered mental status. The patient received multiple doses of benzodiazepines to treat the seizures and developed respiratory insufficiency needing intubation. After extubation, the patient developed hyperactivity, myoclonic, and choreoathetoid movements which were unresponsive to benzodiazepines. Dexmedetomidine was started with good response. The patient made a full clinical recovery. This is the first case that illustrates the possibility to treat MDMA-induced agitation with dexmedetomidine in a 13-month-old infant.