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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 absorbance spectra. (b) Individual cell hemoglobin mass, calculated by least-squares fitting of the hemoglobin-specific absorptive and refractive spectral features (combined average of OV and absorbance measurements for each cell). All stages except for Ring stage show significant changes in intracellular hemoglobin (p < 0.0001 for all significance t-tests).
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f5: (a) Stage-separated absorbance spectra. (b) Individual cell hemoglobin mass, calculated by least-squares fitting of the hemoglobin-specific absorptive and refractive spectral features (combined average of OV and absorbance measurements for each cell). All stages except for Ring stage show significant changes in intracellular hemoglobin (p < 0.0001 for all significance t-tests).

Mentions: The amplitude of transmitted light can also provide a measurement of Hb content. Analysis of the absorbance spectra for the two populations reveals a decrease in the average quantity of hemoglobin present (Fig. 5). The overall absorbance increases with infection, however the characteristic hemoglobin peaks diminish significantly. The absorbance spectra are fit using non-negative linear least-squares regression to the form A(λ) = C1+ −C2· λ + C3εHbO2 (λ) to recover mass-density concentration maps, which are then integrated over the cell area to estimate the mass of hemoglobin contained within each cell. Only oxyHb is included in this fit since deoxyHb and metHb were found to not be substantial contributors to the spectra (~5% for deoxyHb, 0% for metHb) and thus were omitted from the analysis.


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 absorbance spectra. (b) Individual cell hemoglobin mass, calculated by least-squares fitting of the hemoglobin-specific absorptive and refractive spectral features (combined average of OV and absorbance measurements for each cell). All stages except for Ring stage show significant changes in intracellular hemoglobin (p < 0.0001 for all significance t-tests).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: (a) Stage-separated absorbance spectra. (b) Individual cell hemoglobin mass, calculated by least-squares fitting of the hemoglobin-specific absorptive and refractive spectral features (combined average of OV and absorbance measurements for each cell). All stages except for Ring stage show significant changes in intracellular hemoglobin (p < 0.0001 for all significance t-tests).
Mentions: The amplitude of transmitted light can also provide a measurement of Hb content. Analysis of the absorbance spectra for the two populations reveals a decrease in the average quantity of hemoglobin present (Fig. 5). The overall absorbance increases with infection, however the characteristic hemoglobin peaks diminish significantly. The absorbance spectra are fit using non-negative linear least-squares regression to the form A(λ) = C1+ −C2· λ + C3εHbO2 (λ) to recover mass-density concentration maps, which are then integrated over the cell area to estimate the mass of hemoglobin contained within each cell. Only oxyHb is included in this fit since deoxyHb and metHb were found to not be substantial contributors to the spectra (~5% for deoxyHb, 0% for metHb) and thus were omitted from the analysis.

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