ABSTRACT
ABSTRACT Objective: Silicosis is a pneumoconiosis characterized by fibrosis of the lung parenchyma caused by inhalation of silica particles. Genetic factors might play a role in the severity silicosis. We sought to evaluate the influence of polymorphisms in the ACE, FAS, FASLG, NOS2, IL1RN, FAM13A, TGFB1, and TNF genes on the severity of silicosis. Methods: Nine polymorphisms were genotyped by PCR in a sample of 143 patients with silicosis in the state of Rio de Janeiro, Brazil. Results: Fifty-seven patients (40%) were classified as having simple silicosis and 86 (60%) were classified as having complicated silicosis. The TT genotype of rs1800469 in the TGFB1 gene showed a protective effect for complicated silicosis (OR = 0.35; 95% CI, 0.14-0.92; p = 0.028) when compared with the other two genotypes (CC+CT). The polymorphic T allele of rs763110 in the FASLG gene (OR = 0.56; 95% CI, 0.31-0.99; p = 0.047), as well as a dominant model for the T allele (TT+CT: OR = 0.37; 95% CI, 0.15-0.96; p = 0.037), also showed a protective effect. When patients with simple silicosis despite having been exposed to silica for a longer time (> 44,229 hours) were compared with patients with complicated silicosis despite having been exposed to silica for a shorter time, the T allele of rs763110 in the FASLG gene (OR = 0.20; 95% CI, 0.08-0.48; p < 0.0001), as well as dominant and recessive models (OR = 0.06; 95% CI, 0.00-0.49; p = 0.01 and OR = 0.22; 95% CI, 0.06-0.77; p = 0.014, respectively), showed a protective effect against the severity of silicosis. Conclusions: It appears that rs1800469 polymorphisms in the TGFB1 gene and rs763110 polymorphisms in the FASLG gene are involved in the severity of silicosis. Given the lack of studies relating genetic polymorphisms to the severity of silicosis, these results should be replicated in other populations.
RESUMO Objetivo: A silicose é uma pneumoconiose caracterizada por fibrose do parênquima pulmonar causada por inalação de partículas de sílica. Fatores genéticos podem desempenhar um papel na gravidade da silicose. Nosso objetivo foi avaliar a influência de polimorfismos dos genes ACE, FAS, FASLG, NOS2, IL1RN, FAM13A, TGFB1 e TNF na gravidade da silicose. Métodos: Nove polimorfismos foram genotipados por meio de PCR em uma amostra composta por 143 pacientes com silicose no estado do Rio de Janeiro, Brasil. Resultados: A silicose foi classificada em simples em 57 (40%) dos pacientes e em complicada, em 86 (60%). O genótipo TT do polimorfismo rs1800469 do gene TGFB1 teve efeito protetor contra a silicose complicada (OR = 0,35; IC95%: 0,14-0,92; p = 0,028) em comparação com os outros dois genótipos (CC+CT). O alelo T polimórfico do polimorfismo rs763110 do gene FASLG (OR = 0,56; IC95%: 0,31-0,99; p = 0,047) e um modelo dominante do alelo T (TT+CT: OR = 0,37; IC95%: 0,15-0,96; p = 0,037) também tiveram efeito protetor. Quando se compararam os pacientes que tinham silicose simples com um tempo maior de exposição à sílica (> 44.229 horas) àqueles que tinham silicose complicada com um tempo menor de exposição à sílica, o alelo T do polimorfismo rs763110 do gene FASLG (OR = 0,20; IC95%: 0,08-0,48; p < 0,0001) e modelos dominantes e recessivos (OR = 0,06; IC95%: 0,00-0,49; p = 0,01 e OR = 0,22; IC95%: 0,06-0,77; p = 0,014, respectivamente) tiveram efeito protetor contra a gravidade da silicose. Conclusões: Polimorfismos rs1800469 do gene TGFB1 e polimorfismos rs763110 do gene FASLG parecem estar envolvidos na gravidade da silicose. Como há poucos estudos que tenham estabelecido relações entre polimorfismos genéticos e a gravidade da silicose, esses resultados devem ser replicados em outras populações.
ABSTRACT
Several Brazilian Aedes aegypti populations are resistant to the larvicidae temephos. Methoprene, that inhibits adult emergence, is one of the alternatives envisaged by the Brazilian Dengue Control Program (PNCD). However, at Brazil vector infestation rates are measured through larvae indexes and it has been claimed that methoprene use in the field could face operational problems. In order to define a standardized protocol, methoprene effect was evaluated in laboratory conditions after continuous exposure of larvae (Rockefeller strain) to a methoprene formulation available to the PNCD. Methoprene-derived mortality occurs mainly at the pupa stage and pupa development is inversely proportional to methoprene concentration. Number and viability of eggs laid by treated and control females are equivalent. A methoprene dose-dependent delay in the development was noted; however, b correlations were found for total mortality or adult emergence inhibition if data obtained when all control mosquitoes have emerged are compared to data obtained when methoprene-treated groups finish development. The cumulative record of total methoprene-induced mortality at the time control adults emerge is proposed for routine evaluation of field populations. Mortality of all specimens, but not of larva, could account for adult emergence inhibition, confirming the inadequacy of larvae indexes to evaluate methoprene effect.