RESUMO
The classification of the Tabanidae had remained stable over the last 60 years after Mackerras proposed a great revolution in the arrangement of the family. Recently, some new proposals based on molecular data have once again changed the classification of the family, mainly with a focus on the tribe Scionini. The present paper introduces a critical analysis based on the taxonomical view of the recent proposed classification of Scionini. Three genera are discussed: Lepmia Fairchild, Parosca Enderlein, and Pseudoscione Lutz. Lepmia atra (Philippi), L. grisea (Jaennicke), and L. leucothorax (Ricardo) are transferred to a new genus, Sixtomyiagen.n., based on its morphological differences from Lepmia. Other three species receive a new combination: Parosca subulipalpis (Enderlein) n. comb., Pseudoscione albifrons (Macquart) n. comb., Ps. hibernus (Wilkerson & Coscarón) n. comb. A key to species of Sixtomyia is provided and diagnostic characters are illustrated.
Assuntos
Dípteros/classificação , Animais , Dípteros/anatomia & histologia , Feminino , Masculino , Clima TropicalRESUMO
The terrestrial larva of the austral horsefly, Parosca latipalpis (Macquart), identified by molecular techniques, is described. The larva of P. latipalpis resembles Scaptia auriflua (Donovan), Copidapha vicina (Taylor), Myioscaptia muscula (English), and Osca lata (Guérin-Meneville) in many morphological characters, as well as in their terrestrial habitats. Some characters that are shared between these species are unique among Tabanidae and provide evidence of their monophyletic origin, suggesting a typical Gondwanaland group. Larvae of P. latipalpis were found 2-3 cm below of the soil surface and associated with larvae of Coleoptera, Lepidoptera, and Diptera in southern Chile.
Assuntos
Dípteros , Animais , Chile , Dípteros/anatomia & histologia , Dípteros/classificação , Larva , SoloRESUMO
As part of a multi-site research program on the eco-epidemiology and control of Chagas disease in northern Chile, we sought to identify the Trypanosoma cruzi discrete typing units (DTUs) infecting rural and peridomestic dogs, using direct methods without grown of the parasite in the laboratory and thus to assess the use of this species as a sentinel of the disease in well-defined endemic areas of T. cruzi in Chile. Infected dogs (35) from three villages were included in the study. The studied villages were Caleta Río Seco and Caleta San Marcos, both in the Tarapacá Region, and La Serena in the Coquimbo Region. These villages were selected based on previous evidence of Mepraia infection reports of the Chilean Ministry of Health. Amplicons from nested-PCR positive samples were used as targets to determine the infective T. cruzi DTUs circulating in blood using PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). Results of hybridization with dog samples from Caleta Rio Seco showed single infections in 2 out of 16 and mixed infections in 14 out of 16. TcVI was the most frequent DTU found in this area. A highlight is that for the first time the presence of TcIII is reported in this area. Samples from Caleta San Marcos showed single infections in 5 out of 9 and mixed infections in 4 out of 9. TcVI was the most frequent DTU found in this area. Samples from La Serena showed single infections in 5 out of 10 and mixed infections in 2 out of 10; we were unable to genotype the other 3 samples. Our results indicate that infection by T. cruzi DTUs in dogs is not homogeneously distributed but rather specific to each region of our country, as demonstrated by the differences in the T. cruzi DTU distribution in some localities.
RESUMO
Four species of triatomines are known from Chile: Triatoma infestans Klug, Mepraia spinolai Porter, M. gajardoi Frías, Henry & González, and M. parapatrica Frías (Hemiptera: Reduviidae), the last three are endemic. The geographical distribution of M. gajardoi includes the coastal areas in the north of Chile between 18° and 21°S, an area with both a resident workforce and summer-season visitors. A study was developed to assess the risk of vectorial transmission of Chagas disease by M. gajardoi in hut settlements on the coast of the Tarapacá Region, in particular in Caleta San Marcos and Caleta Río Seco. The study comprised fingerstick sampling of 95 persons, venous samples from 29 domestic dogs and capture of 52 triatomines, from both fishing coves. The samples were analysed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. The results show that, of the total number of persons studied, 100% were negative for Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae) antibodies, 10.34% of canids were positive for the antibody and 5.8% of M. gajardoi were infected to the PCR technique. The presence of this species in areas close to human settlements constitutes a risk to human populations established on the coast of northern Chile.
Assuntos
Doença de Chagas/transmissão , Insetos Vetores/fisiologia , Triatominae/fisiologia , Trypanosoma cruzi/fisiologia , Animais , Anticorpos Antiprotozoários/sangue , Doença de Chagas/parasitologia , Chile , Cães , Ensaio de Imunoadsorção Enzimática , Habitação , Humanos , Reação em Cadeia da Polimerase , Risco , Estudos SoroepidemiológicosRESUMO
Transforming growth factor ß1 (TGF-ß1) is a pleiotropic cytokine that modulates cell homeostasis. In Leydig cells, TGF-ß1 exerts stimulatory and inhibitory effect depending on the type I receptor involved in the signaling pathway. The aim of the present work was to study the signaling mechanisms and the intermediates involved in the action of TGF-ß1 on TM3 Leydig cell proliferation in the presence or absence of progesterone. The MTT assay showed that the presence of progesterone in the culture media lead to a proliferative effect that was blocked by Ru 486, an inhibitor of progesterone receptor; and ALK-5 did not participate in this effect. TGF-ß1 (1 ng/ml) increased the expression of p15 (an inhibitor of cell cycle) in TM3 Leydig cells, and this effect was blocked by progesterone (1µM). The expression of PCNA presented a higher increase in the cell cultured with TGF-ß1 plus progesterone than in cells cultured only with TGF-ß1. Progesterone induced the gene expression of endoglin, a cofactor of TGF-ß1 receptor that leads to a stimulatory signaling pathway, despite of the absence of progesterone response element in endoglin gene. In addition, the presence of progesterone induced the gene expression of egr-1 and also KLF14, indicating that this steroid channels the signaling pathway into a non-canonical mechanism. In conclusion, these findings suggest that the proliferative action of TGF-ß1 involves endoglin. This co-receptor might be induced by KLF14 which is probably activated by progesterone.
Assuntos
Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Receptores de Activinas Tipo II , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p15/metabolismo , DNA Complementar/genética , Endoglina , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Progesterona/farmacologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Elementos de Resposta/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
Cell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH.
Assuntos
Diferenciação Celular , Proliferação de Células , Células Germinativas/citologia , Roedores/embriologia , Testículo/crescimento & desenvolvimento , Animais , Células Germinativas/metabolismo , Marcação In Situ das Extremidades Cortadas , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/metabolismo , Masculino , Fator 3 de Transcrição de Octâmero/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Roedores/metabolismo , Células de Sertoli/citologia , Células de Sertoli/metabolismo , Testículo/citologia , Testículo/metabolismoRESUMO
The female of Dasybasis elquiensis, new species, is described and illustrated from specimens collected in Paso La Ternera, Elqui Province, north Chile. Its relationships to other Dasybasis species are discussed.
Assuntos
Dípteros/anatomia & histologia , Animais , Chile , Dípteros/classificação , FemininoRESUMO
Helicobacter pylori infection remains one of the most common in humans, but the route of transmission of the bacterium is still uncertain. This study was designed to elucidate possible sources of infection in an isolated, rural population in Guatemala. A total of 242 subjects in family units participated in the study. A medical history, including a history of dyspepsia, was taken by a physician and immunoglobulin G antibodies to H. pylori were detected with the QuickVue (Quidel, San Diego, Calif.) onsite serology test. Overall, 58% of subjects were seropositive, with a positive relationship between mother and child (P = 0.02) and a positive correlation between the serostatuses of siblings (intraclass correlation coefficient = 0.63). There was no association between serostatus and gastric symptoms. Oral H. pylori was detected from periodontal pockets of various depths and the dorsum of the tongue by nested PCR. Eighty-seven percent of subjects had at least one oral site positive for H. pylori, with the majority of subjects having multiple positive sites. There was no association between periodontal pocket depth and the detection of H. pylori. Nested PCR was also used to detect H. pylori from beneath the nail of the index finger of each subject's dominant hand. Overall, 58% of subjects had a positive fingernail result, with a significant positive relationship between fingernail and tongue positivity (P = 0.002). In conclusion, the results of this study suggest that oral carriage of H. pylori may play a role in the transmission of infection and that the hand may be instrumental in transmission.
Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Adolescente , Adulto , Idoso , América Central/epidemiologia , Feminino , Infecções por Helicobacter/sangue , Infecções por Helicobacter/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Boca/microbiologia , Unhas/microbiologia , Estudos Soroepidemiológicos , Testes SorológicosRESUMO
Attenuated Salmonella typhi are attractive for use as live vector vaccines to express protozoal antigens and deliver them to the human immune system. The gene encoding the mature form of Leishmania mexicana mexicana gp63 under control of tac promoter was integrated into the delta aroC locus of the chromosome of attenuated delta aroC, delta aroD S. typhi strain CVD 908. After oral immunization of BALB/c mice with two 1 x 10(9) colony forming unit doses given 21 days apart, CVD 908 omega (delta aroC::Ptac-gp63) elicited a broad T cell-mediated immune response against L. m. mexicana gp63 as demonstrated by: (1) lymphoproliferative response to fixed whole L. m. mexicana promastigotes; (2) activation of IL-2 (but not IL-4)-producing lymphocytes; (3) appearance of cytotoxic T cells against mouse mastocytoma cells expressing gp63. This T-cell mediated immune response was associated with significant protection in F1 (BALB/cXC57Bl/6) mice challenged in their footpads with a wild type strain of L. m. mexicana.
Assuntos
Antígenos de Protozoários/genética , Leishmania mexicana/genética , Leishmania mexicana/imunologia , Metaloendopeptidases/genética , Metaloendopeptidases/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Salmonella typhi/genética , Salmonella typhi/imunologia , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Administração Oral , Animais , Sequência de Bases , Citotoxicidade Imunológica , Primers do DNA/genética , Genes de Protozoários , Vetores Genéticos , Humanos , Técnicas In Vitro , Interleucina-2/biossíntese , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/prevenção & controle , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Vacinas Protozoárias/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Linfócitos T/imunologia , Vacinas Sintéticas/administração & dosagemRESUMO
The female and male of Dasybasis (Agelanius) cortesi, new species, is described and illustrated from specimens collected in the National Reserve of Río Clarillo, Cordillera Province, Central Chile. Its relationships to other Dasybasis species are discussed.