RESUMEN
Epidemiological studies report an association between exposure to biomass smoke and cardiopulmonary morbidity. The mechanisms for this association are unclear. The aim of the present study was to characterise the acute pulmonary and systemic inflammatory effects of exposure to forest fire smoke. Seasonal forest firefighters (n = 52) were recruited before and/or after a day of fire-fighting. Exposure was assessed by questionnaires and measurement of carbon monoxide levels (used to estimate respirable particulate matter exposure). The pulmonary response was assessed by questionnaires, spirometry and sputum induction. Peripheral blood cell counts and inflammatory cytokines were measured to define the systemic response. Estimated respirable particulate matter exposure was high (peak levels >2 mg x m(-3)) during fire-fighting activities. Respiratory symptoms were reported by 65% of the firefighters. The percentage sputum granulocytes increased significantly from 6.5 to 10.9% following fire-fighting shifts, with concurrent increases in circulating white blood cells (5.55x10(9) to 7.06x10(9) cells x L(-1)) and band cells (0.11x10(9) to 0.16x10(9) cells x L(-1)). Serum interleukin (IL)-6, IL-8 and monocyte chemotactic protein-1 levels significantly increased following fire-fighting. There were no changes in band cells, IL-6, and IL-8 following strenuous physical exertion without fire-fighting. There was a significant association between changes in sputum macrophages containing phagocytosed particles and circulating band cells. In conclusion, acute exposure to air pollution from forest fire smoke elicits inflammation within the lungs, as well as a systemic inflammatory response.
Asunto(s)
Incendios , Macrófagos Alveolares/inmunología , Exposición Profesional/efectos adversos , Neumonía/inmunología , Humo/efectos adversos , Esputo/citología , Adolescente , Adulto , Monóxido de Carbono/análisis , Estudios de Cohortes , Femenino , Encuestas Epidemiológicas , Humanos , Inflamación/sangre , Macrófagos Alveolares/clasificación , Masculino , Persona de Mediana Edad , Neumonía/etiología , Trastornos Respiratorios/etiología , Trastornos Respiratorios/inmunología , Humo/análisis , Espirometría , Esputo/inmunología , ÁrbolesRESUMEN
BACKGROUND: Pancreatic islet transplantation is limited because of immune rejection of the transplanted tissue. Long-term survival of allogeneic pancreatic islet grafts in the absence of systemic immunosuppressive agents should be possible by transfecting the islets directly with DNA encoding immunoregulatory molecules. Localized production of these molecules should affect only the immune cells that come into the vicinity of the foreign tissue. We investigated whether local expression of human CTLA4-Ig or soluble human Fas ligand from biolistically transfected mouse islets would have a protective effect on allograft survival. METHODS: Isolated CBA (H2k) islets were biolistically transfected using the gene gun. The experimental groups were naked gold particles (n=6), empty vector DNA (n=5), DNA encoding human CTLA4-Ig (n=8), or soluble human Fas ligand (n=5). Secretion of the transfected gene product was confirmed by screening islet culture supernatants for protein production using a sandwich ELISA. The blasted islets were transplanted under the kidney capsule of alloxan-diabetic BALB/c (H2d) recipients. RESULTS: Control grafts survived for 23 days, on average. CTLA4-Ig-transfected islets showed a bimodal distribution: 50% of cases survived > or = 46 days and 50% were similar to the controls. In the soluble human Fas ligand group, 80% of grafts survived > or = 50 days. There was no correlation between graft survival times and pretransplant levels of protein production. CONCLUSION: Our results indicate that local production of human CTLA4-Ig or soluble human Fas ligand by biolistically transfected islets can promote allograft survival. This approach should be valuable as a potential immunoprotective therapeutic strategy in tissue transplantation.
Asunto(s)
Antígenos de Diferenciación/fisiología , Supervivencia de Injerto , Inmunoconjugados , Trasplante de Islotes Pancreáticos , Glicoproteínas de Membrana/fisiología , Abatacept , Animales , Antígenos CD , Antígeno CTLA-4 , Proteína Ligando Fas , Oro/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Transfección , Trasplante HomólogoRESUMEN
Dominant gain-of-function mutations can give unique insights into the study of gene function. In addition, gain-of-function mutations, unlike loss-of-function alleles, are not biased against the identification of genetically redundant loci. To identify novel genetic functions active during Caenorhabditis elegans embryogenesis, we have collected a set of dominant temperature-sensitive maternal-effect embryonic lethal mutations. In a previous screen, we isolated eight such mutations, distributed among six genes. In the present study, we describe eight new dominant mutations that identify only three additional genes, yielding a total of 16 dominant mutations found in nine genes. Therefore, it appears that a limited number of C. elegans genes mutate to this phenotype at appreciable frequencies. Five of the genes that we identified by dominant mutations have loss-of-function alleles. Two of these genes may lack loss-of-function phenotypes, indicating that they are nonessential and so may represent redundant loci. Loss-of-function mutations of three other genes are associated with recessive lethality, indicating nonredundancy.