Evolution of the fractal dimension and time correlation of erythrocyte aggregates produced by Ascaris lumbricoides

[摘要] Introduction: Ascaris lumbricoides has been shown to capture erythrocyte sialic acid. Objective: study the evolution of the fractal dimension and the time correlation of erythrocyte aggregates produced by incubation with this helminth. Methods: parasite extracts and larval concentrates were incubated in equal parts with group O erythrocytes in saline and enzymatic media for 90 minutes (treated erythrocytes). Control erythrocytes suspensions were incubated with an equal volume of saline phosphate buffer. Erythrocyte samples were extracted every 10 minutes during incubation. Digital image analysis was used for data collection. The count of isolated cells was estimated a posteriori using box-counting technique. The May & Sugihara method was used for the following comparisons: whole blood control vs. a control sample with the same characteristic; control vs. erythrocytes treated with larval concentrates, and control vs. erythrocytes treated with parasite extracts.Results: fractal dimension analysis of control erythrocytes revealed Brownian motion evolution in both media. Erythrocytes treated with parasite extracts showed deterministic chaotic motion in the saline medium and fractional Brownian motion in the enzymatic medium. The behavior of aggregation kinetics for erythrocytes treated with larval concentrates was intermediate between the two. Time correlation revealed random behavior by the control in both media. It also showed that erythrocytes treated with parasite extracts had deterministic chaotic behavior in the saline medium and weakly self-similar behavior in the enzymatic medium. When compared with samples treated with larval concentrates in both media, the behavior of the control was intermediate between that of the other two processes. Conclusions: the mathematical analyses conducted have allowed characterization of the process of erythrocyte aggregation performed by Ascaris lumbricoides.

[学科分类] 传染病学

[关键词] Ascaris lumbricoides;fractal dimension;time correlation;erythrocyte aggregates