ABSTRACTLack of an adequate animal model ofPlasmodium falciparumsevere malarial anemia (SMA) has hampered the understanding of this highly lethal condition. We developed a model of SMA by infecting C57BL/6 mice withP. chabaudifollowed after recovery byP. bergheiinfection.P. chabaudi/P. berghei-infected mice had an initial 9- to 10-day phase of relatively low parasitemia and severe anemia, followed by a second phase of hyperparasitemia, more profound anemia, reticulocytosis, and death 14 to 21 days after infection.P. chabaudi/P. berghei-infected animals had more intense splenic hematopoiesis, higher interleukin-10 (IL-10)/tumor necrosis factor alpha and IL-12/gamma interferon (IFN-γ) ratios, and higher antibody levels againstP. bergheiandP. chabaudiantigens thanP. berghei-infected orP. chabaudi-recovered animals. Early treatment with chloroquine or artesunate did not prevent the anemia, suggesting that the bulk of red cell destruction was not due to the parasite. Red cells fromP. chabaudi/P. berghei-infected animals had increased surface IgG and C3 by flow cytometry. However, C3−/−mice still developed anemia. Tracking of red cells labeledex vivoandin vivoand analysis of frozen tissue sections by immunofluorescence microscopy showed that red cells fromP. chabaudi/P. berghei-infected animals were removed at an accelerated rate in the liver by erythrophagocytosis. This model is practical and reproducible, and its similarities withP. falciparumSMA in humans makes it an appealing system with which to study the pathogenesis of this condition and explore potential immunomodulatory interventions.
ABSTRACT. SruDLES ABOUT DIFFLUG/A WBOSTOM.J LEIDY (PROTISTA, RHIZOPODA, TESTACEALOBOSEA). This paper repor!s feeding habitats, mos! commom test constitution, and growing curvature obtained under cultivation conditions, and lhe knowing distribution and most commom DifJlugia lobostoma.KEYWORDS. DifJlugia lobostoma, cultivation, growing curvature, Protista.Atualmente DifJlugia lobostoma é certamente um dos testáceos mais conhecidos em todo o mundo (PROWAZEK 1910;RUA 1912;PINTO 1925; GAUTIERLrEvRE & THOMAS 1958;THOMAS 1959; DroNI 1970; VUCETICH 1970 VUCETICH , 1972 VUCETICH , 1973a VUCETICH ,b, 1976 VUCETICH ,1978GREEN 1975;OGDEN & HEDLEY 1980;CHARDEZ 1967 CHARDEZ , 1975 CHARDEZ , 1987 CHARDEZ ,1990SABRI 1988;CHARDEZ et a!. 1989; TORRES & JEBRAM 1994), apresentando uma testa aglutinada de partículas inorgânicas sobre em substrato orgânico. GAUTIER-LrEvRE & THOMAS (1958) chegam a afirmar que este protista é cosmopolita.Dos trabalhos anteriormente citados, a grandc maioria é de caráter sistemá-tico, como CHARDEZ (1987) que cita três variedades raras ocorrentes na Bélgica porém, os que apresentam uma outra conotação, como CHARDEZ et a!. (1989), que apresenta um aspecto limnológico e SABRl (1988) que faz um estudo ecológico.A importância desta espécie, do ponto de vista sistemático e especialmente ecológico, representa o objetivo e a justificativa para a realização de um estudo específico a respeito da mesma.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.