scholarly journals Optical Identification of Plasmodium falciparum Malarial Byproduct for Parasite Density Estimation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Jerry Opoku-Ansah ◽  
Moses Jojo Eghan ◽  
Benjamin Anderson ◽  
Johnson Nyarko Boampong ◽  
Raymond Edziah ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Optical Absorption ◽  
Red Blood Cells ◽  
Parasite Density ◽  
Blood Cells ◽  
Classification Model ◽  
Linear Classification ◽  
Absorption Bands ◽  
Optical Techniques ◽  
Blood Samples

Plasmodium falciparum (P. falciparum) malarial degree of infection, termed as parasite density (PD), estimation is vital for point-of-care diagnosis and treatment of the disease. In this work, we present application of optical techniques: optical absorption and multispectral imaging for P. falciparum malarial byproduct (hemozoin) detection in human‐infected blood samples to estimate PD. The blood samples were collected from volunteers who were tested positive for P. falciparum infections (i-blood), and after treatment, another set of blood samples (u-blood) were also taken. The i-blood samples were grouped based on PD (+, ++, +++, and ++++). Optical densities (ODs) of u-blood samples and i-blood samples at blood absorption bands of 405 nm, 541 nm, and 577 nm showed different optical absorption characteristics. Empirical computation of ratio of the ODs for the blood absorption bands revealed reduction in the ODs with increasing PD. Multispectral images containing uninfected red blood cells (u-RBCs) and P. falciparum‐infected red blood cells (i-RBCs) on unstained blood smear slides exhibited spectrally determined decrease in both reflected and scattered pixel intensities and increase in transmitted pixel intensities with increasing PD. We further propose a linear classification model based on Fisher’s approach using reflected, scattered, and transmitted pixel intensities for easy and inexpensive estimation of PD as an alternative to manual estimation of PD, currently, the widely used technique. Application of the optical techniques and the proposed linear classification model are therefore recommended for improved malaria diagnosis and therapy.

Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

1990 ◽  
Vol 48 (3) ◽  
pp. 914-915
Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
Amelanotic Melanoma ◽  
Cytoplasmic Process ◽  
Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

Endothelin-1 production by a microvascular endothelial cell line treated with Plasmodium falciparum parasitized red blood cells

2002 ◽  
Vol 103 (s2002) ◽  
pp. 464S-466S ◽  
Author(s):  
Nicoletta BASILICO ◽  
Livianna SPECIALE ◽  
Silvia PARAPINI ◽  
Pasquale FERRANTE ◽  
Donatella TARAMELLI
Keyword(s):  
Plasmodium Falciparum ◽  
Endothelial Cell ◽  
Red Blood Cells ◽  
Cell Line ◽  
Blood Cells ◽  
Microvascular Endothelial Cell ◽  
Microvascular Endothelium ◽  
Endothelial Cell Line ◽  
Endothelin 1 ◽  
Microvascular Endothelial

In this study, we investigated the production of endothelin 1 (ET-1) by a human microvascular endothelial cell line, HMEC-1, co-cultured with Plasmodium falciparum-parasitized red blood cells (pRBCs). The results indicate that hypoxia increased the basal level of ET-1 production by HMEC-1 cells after 24 or 48h of treatment. However, the co-incubation of HMEC-1 cells with pRBCs, but not with uninfected RBCs, induced a dose-dependent decrease of both constitutive and hypoxia-induced ET-1 production. The inhibition was not due to a decrease in cell viability, as lactate dehydrogenase release remained constant. These results indicate that pRBCs are able to interfere with both the constitutive and stimulated ET-1 release from the microvascular endothelium, thus inducing local modifications of the vascular tone and of the inflammatory response. This could be of relevance in the pathogenesis of the most severe forms of P. falciparum infections, such as cerebral malaria or malaria during pregnancy.

scholarly journals Dielectric characterization of Plasmodium falciparum -infected red blood cells using microfluidic impedance cytometry

2018 ◽  
Vol 15 (147) ◽  
pp. 20180416 ◽  
Author(s):  
C. Honrado ◽  
L. Ciuffreda ◽  
D. Spencer ◽  
L. Ranford-Cartwright ◽  
H. Morgan
Keyword(s):  
Plasmodium Falciparum ◽  
Dielectric Properties ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Time Course ◽  
Fluorescent Protein ◽  
Clear Understanding ◽  
Infection Cycle ◽  
Dielectric Characterization ◽  
Impedance Cytometry

Although malaria is the world's most life-threatening parasitic disease, there is no clear understanding of how certain biophysical properties of infected cells change during the malaria infection cycle. In this article, we use microfluidic impedance cytometry to measure the dielectric properties of Plasmodium falciparum -infected red blood cells ( i- RBCs) at specific time points during the infection cycle. Individual parasites were identified within i- RBCs using green fluorescent protein (GFP) emission. The dielectric properties of cell sub-populations were determined using the multi-shell model. Analysis showed that the membrane capacitance and cytoplasmic conductivity of i- RBCs increased along the infection time course, due to membrane alterations caused by parasite infection. The volume ratio occupied by the parasite was estimated to vary from less than 10% at earlier stages, to approximately 90% at later stages. This knowledge could be used to develop new label-free cell sorting techniques for sample pre-enrichment, improving diagnosis.

scholarly journals Red blood cells release microparticles containing human argonaute 2 and miRNAs to target genes of Plasmodium falciparum

2017 ◽  
Vol 6 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Zhensheng Wang ◽  
Juemin Xi ◽  
Xiao Hao ◽  
Weiwei Deng ◽  
Juan Liu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Target Genes ◽  
Argonaute 2

scholarly journals Acetylsalicylic acid and morphology of red blood cells

2010 ◽  
Vol 53 (3) ◽  
pp. 575-582 ◽  
Author(s):  
Jacques Natan Grinapel Frydman ◽  
Adenilson de Souza da Fonseca ◽  
Vanessa Câmara da Rocha ◽  
Monica Oliveira Benarroz ◽  
Gabrielle de Souza Rocha ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Control Group ◽  
Blood Samples ◽  
Morphological Alterations ◽  
Blood Smears ◽  
In Vivo Treatment ◽  
Microscopy Data

This work evaluated the effect of in vitro and in vivo treatment with ASA on the morphology of the red blood cells. Blood samples or Wistar rats were treated with ASA for one hour. Blood samples or animals treated with saline were used as control group. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphology of red blood cells were evaluated under optical microscopy. Data showed that the in vitro treatment for one hour with ASA at higher dose used significantly (p<0.05) modified the perimeter/area ratio of the red blood cells. No morphological alterations were obtained with the in vivo treatment. ASA use at highest doses could interfere on shape of red blood cells.

scholarly journals A Profound Membrane Reorganization Defines Susceptibility of Plasmodium falciparum Infected Red Blood Cells to Lysis by Granulysin and Perforin

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria Andrea Hernández-Castañeda ◽  
Marilyne Lavergne ◽  
Pierina Casanova ◽  
Bryan Nydegger ◽  
Carla Merten ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Molecular Mechanisms ◽  
Γδ T Cells ◽  
Parasite Growth ◽  
Complex Life Cycle ◽  
Cholesterol Depletion ◽  
Host Cell Membrane ◽  
Pore Forming Proteins

Malaria remains one of the most serious health problems in developing countries. The causative agent of malaria, Plasmodium spp., have a complex life cycle involving multiple developmental stages as well as different morphological, biochemical and metabolic requirements. We recently found that γδ T cells control parasite growth using pore-forming proteins to deliver their cytotoxic proteases, the granzymes, into blood residing parasites. Here, we follow up on the molecular mechanisms of parasite growth inhibition by human pore-forming proteins. We confirm that Plasmodium falciparum infection efficiently depletes the red blood cells of cholesterol, which renders the parasite surrounding membranes susceptible to lysis by prokaryotic membrane disrupting proteins, such as lymphocytic granulysin or the human cathelicidin LL-37. Interestingly, not the cholesterol depletion but rather the simultaneous exposure of phosphatidylserine, a negatively charged phospholipid, triggers resistance of late stage parasitized red blood cells towards the eukaryotic pore forming protein perforin. Overall, by revealing the molecular events we establish here a pathogen-host interaction that involves host cell membrane remodeling that defines the susceptibility towards cytolytic molecules.

scholarly journals Merocyanine 540-sensitized photoinactivation of human erythrocytes parasitized by Plasmodium falciparum

Blood ◽  
1992 ◽  
Vol 80 (1) ◽  
pp. 21-24 ◽  
Author(s):  
OM Smith ◽  
SA Dolan ◽  
JA Dvorak ◽  
TE Wellems ◽  
F Sieber
Keyword(s):  
Stem Cells ◽  
Plasmodium Falciparum ◽  
Hematopoietic Stem Cells ◽  
Red Blood Cells ◽  
Human Blood ◽  
Blood Cells ◽  
Potential Usefulness ◽  
Hematopoietic Stem ◽  
Infected Blood ◽  
Merocyanine 540

The purpose of this study was to evaluate the photosensitizing dye merocyanine 540 (MC540) as a means for extracorporeal purging of Plasmodium falciparum-infected erythrocytes from human blood. Parasitized red blood cells bound more dye than nonparasitized cells, and exposure to MC540 and light under conditions that are relatively well tolerated by normal erythrocytes and normal pluripotent hematopoietic stem cells reduced the concentration of parasitized cells by as much as 1,000-fold. Cells parasitized by the chloroquine- sensitive HB3 clone and the chloroquine-resistant Dd2 clone of P falciparum were equally susceptible to MC540-sensitized photolysis. These data suggest the potential usefulness of MC540 in the purging of P falciparum-infected blood.

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