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Hemoglobin consumption by P. falciparum in individual erythrocytes imaged via quantitative phase spectroscopy.

Rinehart MT, Park HS, Walzer KA, Chi JT, Wax A - Sci Rep (2016)

Bottom Line: QPS captures hyperspectral holograms of individual RBCs to measure spectroscopic changes across the visible wavelength range (475-700 nm), providing complex information, i.e. amplitude and phase, about the light field which has interacted with the cell.Hb content progressively decreases with parasite life cycle, with an average 72.2% reduction observed for RBCs infected by schizont-stage P. falciparum compared to uninfected cells.The unique ability of QPS to discriminate individual healthy and infected cells using spectroscopic changes indicates that the approach can be used to detect disease.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Biomedical Engineering, Duke University, Durham, NC 27708, US.

ABSTRACT
Plasmodium falciparum infection causes structural and biochemical changes in red blood cells (RBCs). To quantify these changes, we apply a novel optical technique, quantitative phase spectroscopy (QPS) to characterize individual red blood cells (RBCs) during the intraerythrocytic life cycle of P. falciparum. QPS captures hyperspectral holograms of individual RBCs to measure spectroscopic changes across the visible wavelength range (475-700 nm), providing complex information, i.e. amplitude and phase, about the light field which has interacted with the cell. The complex field provides complimentary information on hemoglobin content and cell mass, which are both found to dramatically change upon infection by P. falciparum. Hb content progressively decreases with parasite life cycle, with an average 72.2% reduction observed for RBCs infected by schizont-stage P. falciparum compared to uninfected cells. Infection also resulted in a 33.1% reduction in RBC's optical volume, a measure of the cells' non-aqueous components. Notably, optical volume is only partially correlated with hemoglobin content, suggesting that changes in other dry mass components such as parasite mass may also be assessed using this technique. The unique ability of QPS to discriminate individual healthy and infected cells using spectroscopic changes indicates that the approach can be used to detect disease.

No MeSH data available.


Related in: MedlinePlus

(a) Stage-separated OV spectra. (b) Spectrally-averaged OV across cell groups examined in this study. Cells infected by ring-stage and early trophozoite parasites show no significant OV changes. Late Trophozoite, Early Schizont, and Late Schizont infected RBCs show a progressive decrease in OV with highly statistically significant differences compared to uninfected and ring stage.
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f4: (a) Stage-separated OV spectra. (b) Spectrally-averaged OV across cell groups examined in this study. Cells infected by ring-stage and early trophozoite parasites show no significant OV changes. Late Trophozoite, Early Schizont, and Late Schizont infected RBCs show a progressive decrease in OV with highly statistically significant differences compared to uninfected and ring stage.

Mentions: As noted above, both the amplitude and phase of the transmitted light field can be used to determine the total mass of hemoglobin within each cell. The OV spectrum is calculated from the phase of transmitted light for each cell and the average for each population is shown in Fig. 4 (a). The spectrally-averaged OV of uninfected RBCs was found to be significantly higher than that of the infected cells (Fig. 4(b)), even though RBC’s infected with P. falciparum may exhibit a larger maximum OPL, as seen in Fig. 2. Cells infected with P. falciparum also display a wider range of volumes, potentially indicating variation in the dynamics of parasite growth and hemoglobin consumption. Table 1 summarizes the OV measurements for each of the populations. Significant decreases in OV were seen for all infection stages except for the ring and early trophozoite stages. In addition to differences in the averaged OV, Fig. 4(a) also shows that the nonlinear spectral features associated with oxy-hemoglobin (520–600 nm) are more prominent in the uninfected RBC population.


Hemoglobin consumption by P. falciparum in individual erythrocytes imaged via quantitative phase spectroscopy.

Rinehart MT, Park HS, Walzer KA, Chi JT, Wax A - Sci Rep (2016)

(a) Stage-separated OV spectra. (b) Spectrally-averaged OV across cell groups examined in this study. Cells infected by ring-stage and early trophozoite parasites show no significant OV changes. Late Trophozoite, Early Schizont, and Late Schizont infected RBCs show a progressive decrease in OV with highly statistically significant differences compared to uninfected and ring stage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834482&req=5

f4: (a) Stage-separated OV spectra. (b) Spectrally-averaged OV across cell groups examined in this study. Cells infected by ring-stage and early trophozoite parasites show no significant OV changes. Late Trophozoite, Early Schizont, and Late Schizont infected RBCs show a progressive decrease in OV with highly statistically significant differences compared to uninfected and ring stage.
Mentions: As noted above, both the amplitude and phase of the transmitted light field can be used to determine the total mass of hemoglobin within each cell. The OV spectrum is calculated from the phase of transmitted light for each cell and the average for each population is shown in Fig. 4 (a). The spectrally-averaged OV of uninfected RBCs was found to be significantly higher than that of the infected cells (Fig. 4(b)), even though RBC’s infected with P. falciparum may exhibit a larger maximum OPL, as seen in Fig. 2. Cells infected with P. falciparum also display a wider range of volumes, potentially indicating variation in the dynamics of parasite growth and hemoglobin consumption. Table 1 summarizes the OV measurements for each of the populations. Significant decreases in OV were seen for all infection stages except for the ring and early trophozoite stages. In addition to differences in the averaged OV, Fig. 4(a) also shows that the nonlinear spectral features associated with oxy-hemoglobin (520–600 nm) are more prominent in the uninfected RBC population.

Bottom Line: QPS captures hyperspectral holograms of individual RBCs to measure spectroscopic changes across the visible wavelength range (475-700 nm), providing complex information, i.e. amplitude and phase, about the light field which has interacted with the cell.Hb content progressively decreases with parasite life cycle, with an average 72.2% reduction observed for RBCs infected by schizont-stage P. falciparum compared to uninfected cells.The unique ability of QPS to discriminate individual healthy and infected cells using spectroscopic changes indicates that the approach can be used to detect disease.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Biomedical Engineering, Duke University, Durham, NC 27708, US.

ABSTRACT
Plasmodium falciparum infection causes structural and biochemical changes in red blood cells (RBCs). To quantify these changes, we apply a novel optical technique, quantitative phase spectroscopy (QPS) to characterize individual red blood cells (RBCs) during the intraerythrocytic life cycle of P. falciparum. QPS captures hyperspectral holograms of individual RBCs to measure spectroscopic changes across the visible wavelength range (475-700 nm), providing complex information, i.e. amplitude and phase, about the light field which has interacted with the cell. The complex field provides complimentary information on hemoglobin content and cell mass, which are both found to dramatically change upon infection by P. falciparum. Hb content progressively decreases with parasite life cycle, with an average 72.2% reduction observed for RBCs infected by schizont-stage P. falciparum compared to uninfected cells. Infection also resulted in a 33.1% reduction in RBC's optical volume, a measure of the cells' non-aqueous components. Notably, optical volume is only partially correlated with hemoglobin content, suggesting that changes in other dry mass components such as parasite mass may also be assessed using this technique. The unique ability of QPS to discriminate individual healthy and infected cells using spectroscopic changes indicates that the approach can be used to detect disease.

No MeSH data available.


Related in: MedlinePlus