RESUMO
Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of recent secondary contact between both lineages. We suggest that vector control programs should make a greater effort in the entomological surveillance of those regions with both chromosomal groups to avoid rapid emergence of resistant individuals.
Assuntos
Doença de Chagas/transmissão , Cromossomos de Insetos , Insetos Vetores/genética , Triatoma/genética , Animais , Brasil , Bandeamento Cromossômico , DNA Ribossômico/genética , Feminino , Marcadores Genéticos , Geografia , Humanos , Masculino , RNA Ribossômico , Triatoma/parasitologia , Trypanosoma cruziRESUMO
OBJECTIVE: New endoscopic techniques have been developed as an alternative to surgical treatment of bronchopleural fistula. The objective of this study was to analyze our experience with endoscopic treatment of such fistulas. MATERIAL AND METHODS: We conducted a retrospective study of patients with bronchopleural fistula diagnosed by fiberoptic bronchoscopy. Patient characteristics, underlying disease, fistula size, and outcome of endoscopic treatment were analyzed. The endoscopic technique consisted of injection of fibrin sealants (Histoacryl and/or Tissucol) through the catheter of the fiberoptic bronchoscope. RESULTS: Between 1997 and 2004, 18 patients were diagnosed with bronchopleural fistula by fiberoptic bronchoscopy. All were men with a mean (SD) age of 62 (12) years. Bronchopleural fistula was diagnosed after neoplastic surgery in 16 patients, in the bronchial suture after lung transplantation in 1 patient, and concurrently with pleural effusion due to hydatidosis in the remaining patient. The size of the fistula ranged from 1 mm to 10 mm (mean 3.6 [2.7] mm). Fibrin sealants were applied in 14 patients, 2 underwent direct surgery after diagnosis, and the bronchopleural fistula closed spontaneously in the remaining 2. The fibrin sealant used was Histoacryl in 12 patients and Tissucol in 2. Pleural drainage was employed simultaneously and antibiotic therapy was administered at the discretion of the surgeon. The 4 patients whose bronchopleural fistula was associated with empyema also underwent pleural lavage. In 12 patients the fistulas closed as a result of the endoscopic technique (85.7%), and no complications were observed. For 85.7%, fewer than 3 applications of fibrin sealant were necessary. CONCLUSIONS: The success rate of closure of bronchopleural fistula with fibrin sealants injected under guidance with fiberoptic bronchoscopy is high and there are no complications. This technique can render surgery unnecessary.
Assuntos
Fístula Brônquica/terapia , Broncoscopia , Embucrilato , Doenças Pleurais/terapia , Fístula do Sistema Respiratório/terapia , Adesivos Teciduais , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Objetivo: Se han desarrollado nuevas técnicas endoscópicas como alternativa al tratamiento quirúrgico de las fístulas bronquiales (FB). El objetivo de nuestro trabajo ha sido analizar nuestra experiencia en el tratamiento endoscópico de las FB. Material y métodos: Hemos realizado un estudio retrospectivo de los pacientes con FB diagnosticados por fibrobroncoscopia analizando sus características, enfermedad causal de la fístula, tamaño y resultados del tratamiento endoscópico. La técnica endoscópica consistió en la instilación mediante catéter a través del fibrobroncoscopio de sustancias sellantes (SS) (Histoacryl® y/o Tissucol®). Resultados: Entre 1997 y 2004 diagnosticamos 18 FB a través de fibrobroncoscopia, todas ellas en varones con una edad media (± desviación estándar) de 62 ± 12 años. En 16 pacientes la FB se produjo tras cirugía de neoplasia, en uno apareció en la sutura bronquial de un trasplante pulmonar y en otro fue simultánea a un derrame pleural por hidatidosis. El tamaño osciló entre 1 y 10 mm (media de 3,6 ± 2,7 mm). Aplicamos SS en 14 pacientes, en 2 se realizó cirugía directamente tras el diagnóstico y en otros 2 la FB cerró espontáneamente. Las SS utilizadas fueron Histoacryl® en 12 pacientes y Tissucol® en otros 2. Simultáneamente se empleó drenaje pleural y antibioterapia sistémica según criterio del cirujano. En los 4 casos donde la FB estaba asociada a empiema se aplicaron además lavados pleurales. La técnica endoscópica cerró la FB en 12 pacientes (85,7%) sin complicaciones asociadas. En el 85,7% fueron necesarias menos de 3 aplicaciones de SS. Conclusiones: La utilización de SS, mediante técnicas de fibrobroncoscopia, permite el cierre de las FB con un alto porcentaje de éxito, un número reducido de aplicaciones y nula morbilidad, evitando la cirugía de la fístula
Objective: New endoscopic techniques have been developed as an alternative to surgical treatment of bronchopleural fistula. The objective of this study was to analyze our experience with endoscopic treatment of such fistulas. Material and methods: We conducted a retrospective study of patients with bronchopleural fistula diagnosed by fiberoptic bronchoscopy. Patient characteristics, underlying disease, fistula size, and outcome of endoscopic treatment were analyzed. The endoscopic technique consisted of injection of fibrin sealants (Histoacryl® and/or Tissucol®) through the catheter of the fiberoptic bronchoscope. Results: Between 1997 and 2004, 18 patients were diagnosed with bronchopleural fistula by fiberoptic bronchoscopy. All were men with a mean (SD) age of 62 (12) years. Bronchopleural fistula was diagnosed after neoplastic surgery in 16 patients, in the bronchial suture after lung transplantation in 1 patient, and concurrently with pleural effusion due to hydatidosis in the remaining patient. The size of the fistula ranged from 1 mm to 10 mm (mean 3.6 [2.7] mm). Fibrin sealants were applied in 14 patients, 2 underwent direct surgery after diagnosis, and the bronchopleural fistula closed spontaneously in the remaining 2. The fibrin sealant used was Histoacryl® in 12 patients and Tissucol® in 2. Pleural drainage was employed simultaneously and antibiotic therapy was administered at the discretion of the surgeon. The 4 patients whose bronchopleural fistula was associated with empyema also underwent pleural lavage. In 12 patients the fistulas closed as a result of the endoscopic technique (85.7%), and no complications were observed. For 85.7%, fewer than 3 applications of fibrin sealant were necessary. Conclusions: The success rate of closure of bronchopleural fistula with fibrin sealants injected under guidance with fiberoptic bronchoscopy is high and there are no complications. This technique can render surgery unnecessary