PMC

Demonstration of heparin binding on the surfaces of free merozoites. B. bovis-infected RBCs were preincubated with heparin-FITC, followed by fixation with acetone-methanol, and were then examined under a confocal laser scanning microscope. The heparin-antigen reaction (green) and nucleus (red) were visualized by staining with FITC and PI, respectively. A diffuse fluorescence reaction was detectable only around free merozoites (A) and not on the infected RBCs (B). Bars, 5 μm.

Light micrographs of heparin 1-treated B. bovis in in vitro culture. Micrographs were taken on the first day of no treatment (A), treatment with 20 U of heparin per ml (B), and treatment with 100 U of heparin per ml (C). Note the increase in the numbers of abnormally multidividing forms (B) and free merozoites (C) (arrows) compared to those for the controls (A). Bars, 20 μm.

In vitro growth rates of B. bigemina (A), B. caballi (B), and B. equi (C) in the presence of different concentrations of heparin 1 (in units per milliliter). Parasite viability was monitored in subcultures for 10 days without heparin. +, viable cells; −, dead cells. Each value represents the mean ± standard deviation for three separate trials, carried out in triplicate.

(A) In vitro growth rate of B. bovis in the presence of different concentrations of heparin 1 (in units per milliliter). Parasitic viability was monitored in subcultures for 10 days without heparin. +, viable parasites; −, dead parasites. (B) Percentage of abnormally multidividing forms of heparin-treated B. bovis parasites in cultures. *, significant difference (P < 0.01) between the heparin-treated groups and the control group. Each value represents the mean ± standard deviation for three separate trials, carried out in triplicate.

(A) Inhibitory effects of 500, 250, 100, 20, or 4 U of heparin 1 per mouse on the course of B. microti infection in mice. Each value represents the mean ± standard deviation for observations for 10 mice in each group. *, statistically significant differences (P < 0.01) between the group treated with 100 U of heparin and the control group; #, times of subcutaneous inoculation of heparin or the control reagent (PBS). (B) Localization of heparin-recognizing locus. B. microti-infected blood was preincubated with heparin-FITC, followed by fixation with acetone-methanol, and was then examined under a confocal laser scanning microscope. The heparin-antigen reaction (green) and nucleus (red) were visualized by staining with FITC and PI, respectively. Distinct fluorescence was detectable around free merozoites (arrow) but not the infected RBC. Bar, 5 μm.