RESUMO
The aim of this study was to determine the presence of microplastics (MPs) in the upper respiratory tract of indoor and outdoor workers, to assess the type and the extent of contamination. Sputum and nasal lavage fluid were collected, and plastic particles were quantitatively analyzed by polarizing microscopy and a laser direct infrared chemical imaging system. The polarized light microscopy results showed that suspicious MPs were found in the nasal lavage and sputum of both couriers and office staff, and the abundance of MPs in the nasal lavage of office staff was significantly higher than in couriers (P < 0.0001). The chemical imaging results showed that polycarbonate (24.2%) and polyvinylchloride (PVC) (23.0%) were the predominant plastic materials in the sputum of couriers, while polyamide (PA) (25.3%) and polyethylene (22.9%) were dominant in the nasal lavage fluid. The sputum and nasal lavage fluid of office staff were both dominated by PVC (39.1% and 41.1%, respectively) and PA (24.8% and 31.6%, respectively). Therefore, this study revealed that microplastic pollution was found in the respiratory tract of both indoor and outdoor workers, but the distribution of MP particles differed between the two populations.
Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Nylons , Plásticos , Polietileno , Cloreto de Polivinila , Poluentes Químicos da Água/análiseAssuntos
AMP Cíclico/metabolismo , Fluorometria/métodos , Canais Iônicos/fisiologia , Receptores Adrenérgicos beta/fisiologia , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Linhagem Celular , Colforsina/farmacologia , Canais de Cátion Regulados por Nucleotídeos Cíclicos , Relação Dose-Resposta a Droga , Humanos , Canais Iônicos/agonistas , Canais Iônicos/antagonistas & inibidores , Isoproterenol/farmacologia , Metoprolol/farmacologiaRESUMO
Adenosine-3',5'-cyclic monophosphate (cAMP) conveys the signals from G-protein coupled receptors (GPCRs) and regulates a variety of downstream cellular events. However, there are few robust assays available for measuring cAMP in live cells. Most of the existing cAMP assays require cell lysis and/or have relatively low throughput. We report a live cell-based cAMP assay that has been developed to record the real-time changes in intracellular cAMP. By employing a mutated cyclic-nucleotide-gated ion channel (CNGC) as the cAMP biosensor, the change of cAMP level is coupled to the change of transmembrane potential that is measured through a new fluorescent membrane potential (MP)-sensitive dye, HLB 021-152. We have successfully used HLB 021-152 for homogeneously monitoring cAMP stimulations in live cells under both serum-containing and serum-free environments. Upon stimulating the endogenous or heterogenous GPCRs on CNGC-cloned human embryonic kidney 293 cells with agonists, the fluorescence signal of HLB 021-152 increases rapidly. It has much greater assay dynamic range than DiSBAC2(3), the existing "gold standard" dye for measuring cellular MP. This new MP dye can be readily formulated for high throughput screening of GPCR modulators either with serum or without serum.
Assuntos
Técnicas Biossensoriais/métodos , AMP Cíclico/análise , Corantes Fluorescentes/química , Células 3T3 , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Animais , Barbitúricos/química , Linhagem Celular , AMP Cíclico/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Relação Dose-Resposta a Droga , Fluorescência , Humanos , Canais Iônicos/metabolismo , Isoxazóis/química , Cinética , Potenciais da Membrana/fisiologia , Camundongos , Microscopia de Fluorescência/métodos , Estrutura Molecular , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , Cloreto de Potássio/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Prostaglandina E/metabolismo , Tiobarbitúricos , Fatores de TempoRESUMO
Synthetic approaches that vigorously control the microstructures of water-dispersible gamma-Fe(2)O(3) nanoparticles such as size and size uniformity are of importance to the potential biological applications of these nanomaterials. In the present paper, water-dispersible gamma-Fe(2)O(3) nanocrystals with narrow size distributions (bipy-Fe(2)O(3)) were prepared via a site-exchange reaction. These particular materials are superparamagnetic and stable within a wide range of pH. Introduction of the biotin functionality onto the surfaces of bipy-Fe(2)O(3) enabled the affinity isolation of the protein avidin from its incubation solution magnetically with 96% efficiency.
Assuntos
Avidina/isolamento & purificação , Compostos Férricos/química , Nanotecnologia/métodos , Água/química , Tamanho da PartículaRESUMO
Highly crystalline gamma-Fe(2)O(3) nanoparticles with narrow size distributions that are coated with 1-undecanesulfonic acid were synthesized via two distinct approaches using oxidation and site-exchange reactions. However, similar nanocrystals protected with 1-octanol could only be achieved via the site-exchange method, while the oxidation approach led to Fe(2)O(3) nanoparticles of poor crystallinity and size uniformity. Our magnetization measurements confirmed the superparamagnetic nature of our Fe(2)O(3) nanoparticle products and the effects of the coating materials on magnetization properties.
