848 resultados para SCHISTOSOMIASIS
Resumo:
Introduction - This study was designed to determine the presence and identity of potential intermediate snail hosts of schistosomiasis in Bengo, Luanda, Kwanza Norte and Malanje Provinces in NW Angola. This is an area where infection with Schistosoma haematobium, causing urogenital schistosomiasis, is common but little is known about transmission of the disease. Angola has had a varied past with regards to disease control and is revitalising efforts to combat Neglected Tropical Diseases.
Resumo:
This review summarizes the research progress made over the past decade in the field of gastropod immunity resulting from investigations of the interaction between the snail Biomphalaria glabrata and its trematode parasites. A combination of integrated approaches, including cellular, genetic and comparative molecular and proteomic approaches have revealed novel molecular components involved in mediating Biomphalaria immune responses that provide insights into the nature of host-parasite compatibility and the mechanisms involved in parasite recognition and killing. The current overview emphasizes that the interaction between B. glabrata and its trematode parasites involves a complex molecular crosstalk between numerous antigens, immune receptors, effectors and anti-effector systems that are highly diverse structurally and extremely variable in expression between and within host and parasite populations. Ultimately, integration of these molecular signals will determine the outcome of a specific interaction between a B. glabrata individual and its interacting trematodes. Understanding these complex molecular interactions and identifying key factors that may be targeted to impairment of schistosome development in the snail host is crucial to generating new alternative schistosomiasis control strategies.
Resumo:
Schistosomiasis is a parasitic disease which kills a half million people per year, a I I over the world. Praziquantel (PZQ) is the drug-of-choice for schistosomiasis because of its effectiveness, ease of administration, and low cost. However, poor solubility restricts its delivery, especially via the oral route. In this study, we describe beta-cyclodextrin (beta-CD) complexation as an alternative to improve the PZQ bioavailability. Physicochemical analysis were performed to characterize the inclusion complex formed between PZQ and beta-CD. Differential scanning calorimetry (DSC) thermograms and morphological analysis using scanning electronic microscopy (SEM) gave evidences of the complex formation. Diffusion NMR experiments allowed determination of the fraction of PZQ bound to beta-CD (37%) and the association constant (941 +/- 47 M(-1)). The in vivo evaluation of the complexation on the effect of PZQ was performed on mice infected with Schistosoma mansoni (BH strain); after 15 days of treatment with the PZQ:beta-CD complex the efficacy, evaluated by the number of remaining alive worms, was 99%, against 59% elicited by plain PZQ.
Resumo:
A number of infectious diseases amongst travelers and the immigrant populations are a major public health concern. Some have a long incubation period or remain asymptomatic or paucisymptomatic for many years before leading to significant clinical manifestations and/or complications. HIV, hepatitis B and C, tuberculosis or latent syphilis are among the most significant persistent diseases in migrants. Schistosomiasis and strongyloidiasis, for instance, are persistent helminthic infections that may cause significant morbidity, particularly in patients co-infected with HIV, hepatitis B and C. Chagas disease, which was initially confined to Latin America, must also now be considered in immigrants from endemic countries. Visceral leishmaniasis and malaria are other examples of parasitic diseases that must be taken into account by physicians treating incarcerated migrants. The focus of this review article is on the risk of neglected tropical diseases in particularly vulnerable correctional populations and on the risk of infectious diseases that commonly affect migrants but which are often underestimated.
Resumo:
Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-γ, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.
Resumo:
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Nanociência e Nanobiotecnologia, 2016.