ABSTRACT
BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.
ABSTRACT
BACKGROUND In Brazil, Leishmania (Leishmania) infantum is a widely distributed protozoan parasite. The human leishmaniasis caused by this species is often associated with visceral form. Tegumentary leishmaniasis (TL) cases due to L. (L.) infantum in the country are considered rare but may be underestimated. Although probably uncommon, these cases represent a new challenge to the prevention and control of leishmaniasis. OBJECTIVES Here, we describe two distinct cases of TL with atypical clinical presentations caused by L. (L.) infantum. METHODS AND FINDINGS Parasites were isolated from cutaneous lesions of the two patients and typed as L. (L.) infantum after sequencing of the ribosomal DNA internal transcribed spacer. The dermotropic L. (L.) infantum isolates were compared in terms of growth culture patterns, metacyclogenesis and in vitro infectivity in macrophages. MAIN CONCLUSIONS This study addresses the emergence of L. (L.) infantum as a causative agent of cutaneous disease in a visceral leishmaniasis hotspot located in northeast Brazil. The data presented provides novel information about the presence of dermotropic L. (L.) infantum in the country and demonstrates the infectivity potential of theses isolates.
ABSTRACT
Doenças tireoideanas são bastante comuns, sendo sua maioria benigna. A relação entre os diversos tipos de doenças tireoideanas, bem como seus aspectos moleculares, são pouco conhecidos. O bócio (hiperplasia), por exemplo, é descrito por alguns como relacionado com carcinoma (tumor maligno) papilífero, enquanto que outros afirmam não haver relação causal entre as duas doenças. A questão mais desafiante, porém, refere-se à distinção entre adenoma (tumor benigno) e carcinoma folicular, que atualmente é feita apenas após à cirurgia, não permitindo tratamento diferenciado para os dois tipos de tumor. Este trabalho buscou identificar genes diferencialmente expressos entre tecido tireoideano normal, bócio, adenoma e carcinoma papilífero utilizando microarrays...