Acanthamoeba : Observations on Animal Pathogenicity

Abstract

the percentage retention of Ca45 about twofold, while having no significant effect on Sr90 retention.The last column of Table 1 shows the total calcium derived from the diet, which is deposited and retained during the course of the experiment. These figures are calculated from the measured Ca45 concentration in the bone and the known ratio of Ca45 to stable calcium in the diet. While rather close physiological control of dietary calcium utilization is evidenced at the two lower dietary levels, this control is no longer very effective at the 2-percent calcium level.Blood levels of Sr90 and Ca45 at different times of sacrifice were reasonably constant within a given dietary group. Between dietary groups, the blood levels of Sr90 and Ca45 varied in essentially the same manner as their concentrations in the femur. In general, for a given group of animals, the ratio of Sr90/Ca45 in the blood was not significantly different from the ratio of Sr90/Ca45 in the bone; this suggests, as others have pointed out (2), that the major discrimination between dietary calcium and strontium does not occur in the specific processes of deposition on the bone. Because total calcium analyses on blood were not obtained, and in view of the limited time period studied, closer intercomparison of the blood and bone data with a view toward elucidating discrimination mechanisms would not seem to be justified.Wasserman et al. have recently described an experiment in which Sr90 and Ca45 were chronically administered with diets varying in total calcium content from 0.5 to 2.0 percent (4). The skeletal deposition of both Sr90 and Ca45 in their experiment was inversely proportional to

Ceratite bilateral por Acanthamoeba: relato de caso

“…O uso de lentes de contato na população geral é muito alto e cresce continuamente (mais de 20 milhões de usuários apenas nos Estados Unidos), bem como o seu uso incorreto (8) . A Acanthamoeba pode ser encontrada na água doce, água salgada, solo e ar (31) , em quase todas as regiões do globo (32) , indicando uma maior incidência de ceratite por este parasita. Uma explicação para tal fato, seria a transformação da Acanthamoeba de uma forma saprófita inócua, em um patóge-no virulento, com a contribuição de alguns fatores, como o uso indevido de esteróides ou infecções oftalmológicas concomitantes (33) .…”

Granulomatous Amoebic Encephalitis: Clinical Diagnosis and Management

“…However, in the late 1950s, they were discovered as tissue culture contaminants [14,15] . Later, Culbertson et al [14,16] demonstrated, for the first time, the pathogenic potential of these organisms by exhibiting their ability to produce cytopathic effects on monkey kidney cells in vitro and to kill laboratory animals, i.e., monkeys in vivo. The first clearly identified GAE due to Acanthamoeba was observed in 1972 [17] .…”

Autoimmunity in the Mediation of Granulomatous Amoebic Encephalitis: Implications for Therapy

“…can cause choriomeningitis and destructive encephalomyelitis in mice and monkeys (Culbertson, et al, 1958, Culbertson, et al, 1959. The mouse model is widely used to study the pathogenesis of GAE (Kim, et al, 1990, Janitschke, et al, 1996, MarcianoCabral, et al, 2001, Gornik & Kuzna-Grygiel, 2005, Khan, 2009.…”