scholarly journals Quantifying the biophysical characteristics of Plasmodium-falciparum-parasitized red blood cells in microcirculation

2010 ◽  
Vol 108 (1) ◽  
pp. 35-39 ◽  
Author(s):  
D. A. Fedosov ◽  
B. Caswell ◽  
S. Suresh ◽  
G. E. Karniadakis

The pathogenicity of Plasmodium falciparum (Pf) malaria results from the stiffening of red blood cells (RBCs) and its ability to adhere to endothelial cells (cytoadherence). The dynamics of Pf-parasitized RBCs is studied by three-dimensional mesoscopic simulations of flow in cylindrical capillaries in order to predict the flow resistance enhancement at different parasitemia levels. In addition, the adhesive dynamics of Pf-RBCs is explored for various parameters revealing several types of cell dynamics such as firm adhesion, very slow slipping along the wall, and intermittent flipping. The parasite inside the RBC is modeled explicitly in order to capture phenomena such as “hindered tumbling” motion of the RBC and the sudden transition from firm RBC cytoadherence to flipping on the endothelial surface. These predictions are in quantitative agreement with recent experimental observations, and thus the three-dimensional modeling method presented here provides new capabilities for guiding and interpreting future in vitro and in vivo studies of malaria.

Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold

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).


1912 ◽  
Vol 16 (4) ◽  
pp. 567-579 ◽  
Author(s):  
C. C. Bass ◽  
Foster M. Johns

The asexual cycle of Plasmodium vivax and Plasmodium falciparum has been cultivated in vitro in human blood. The parasites have been grown also in red blood cells in the presence of Locke's solution, free of calcium chlorid and in the presence of ascitic fluid. The parasites grow within red blood cells and there is no evidence that they can be grown outside of these cells. The parasites are destroyed in a very few minutes in vitro by normal human serum or by all modifications of serum that we have tested. This fact, together with numerous observations of parasites in all stages of growth apparently within red cells, renders untenable the idea of extracorpuscular development. Leucocytes phagocytize and destroy malarial plasmodia growing in vitro only when the parasites escape from their red blood cell capsule or when the latter is perforated or becomes permeable. Successive generations of Plasmodium vivax and Plasmodium falciparum have been cultivated in vitro by removing the leucocytes from the culture and by transplanting to fresh red blood cells and serum at proper intervals. The asexual cycle of Plasmodium vivax and Plasmodium falciparum cultivated in vitro does not differ from the same cycle growing in vivo. The sexual cycle has not been cultivated, though we have obtained some evidence of the possibility of its accomplishment. There can no longer be any doubt that Plasmodium vivax and Plasmodium falciparum are separate and distinct species. When grown in an identical culture medium and under exactly the same conditions they remain distinct. In twenty-nine cultures of æstivo-autumnal parasites many forms and sizes have been observed, so that evidence is supplied of the occurrence of different varieties of ætivo-autumnal malarial plasmodia. The so called tertian ætivo-autumnal variety may be seen at the proper stage in all cultures grown from merozoites. The form and appearance of the same culture of plasmodia may vary greatly under different conditions which are not necessarily destructive to the parasites. Their generation period may vary from thirty hours (ætivo-autumnal) to four days (tertian), as a result of variation in the temperature at which they were cultivated. Sexual parasites grow in the cultures and are more resistant to unfavorable conditions than schizonts, often living several days after the latter die out. Forms suggesting parthenogenesis have been observed.


1988 ◽  
Vol 74 (3) ◽  
pp. 514 ◽  
Author(s):  
Eliana M. M. Rocha ◽  
Leogenes H. Pereira ◽  
Virgilio E. do Rosario ◽  
Antoniana U. Krettli

2008 ◽  
Vol 76 (12) ◽  
pp. 5565-5580 ◽  
Author(s):  
Inès Vigan-Womas ◽  
Micheline Guillotte ◽  
Cécile Le Scanf ◽  
Sébastien Igonet ◽  
Stéphane Petres ◽  
...  

ABSTRACTIn theSaimiri sciureusmonkey, erythrocytes infected with the varO antigenic variant of thePlasmodium falciparumPalo Alto 89F5 clone bind uninfected red blood cells (rosetting), form autoagglutinates, and have a high multiplication rate, three phenotypic characteristics that are associated with severe malaria in human patients. We report here that varO parasites express avargene having the characteristics of group Avargenes, and we show that the varO Duffy binding-like 1α1(DBL1α1) domain is implicated in the rosetting of bothS. sciureusand human erythrocytes. The soluble varO N-terminal sequence (NTS)-DBL1α1recombinant domain, produced in a baculovirus-insect cell system, induced high titers of antibodies that reacted with varO-infected red blood cells and disrupted varO rosettes. varO parasites were culture adapted in vitro using human erythrocytes. They formed rosettes and autoagglutinates, and they had the same surface serotype and expressed the samevarOgene as the monkey-propagated parasites. To develop an in vitro model with highly homogeneous varO parasites, rosette purification was combined with positive selection by panning with a varO NTS-DBL1α1-specific mouse monoclonal antibody. The single-variant, clonal parasites were used to analyze seroprevalence for varO at the village level in a setting where malaria is holoendemic (Dielmo, Senegal). We found 93.6% (95% confidence interval, 89.7 to 96.4%) seroprevalence for varO surface-reacting antibodies and 86.7% (95% confidence interval, 82.8 to 91.6%) seroprevalence for the recombinant NTS-DBL1α1domain, and virtually all permanent residents had seroconverted by the age of 5 years. These data imply that the varO model is a relevant in vivo and in vitro model for rosetting and autoagglutination that can be used for rational development of vaccine candidates and therapeutic strategies aimed at preventing malaria pathology.


Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Anastasia Maslianitsyna ◽  
Petr Ermolinskiy ◽  
Andrei Lugovtsov ◽  
Alexandra Pigurenko ◽  
Maria Sasonko ◽  
...  

Coronary heart disease (CHD) has serious implications for human health and needs to be diagnosed as early as possible. In this article in vivo and in vitro optical methods are used to study blood properties related to the aggregation of red blood cells in patients with CHD and comorbidities such as type 2 diabetes mellitus (T2DM). The results show not only a significant difference of the aggregation in patients compared to healthy people, but also a correspondence between in vivo and in vitro parameters. Red blood cells aggregate in CHD patients faster and more numerously; in particular the aggregation index increases by 20 ± 7%. The presence of T2DM also significantly elevates aggregation in CHD patients. This work demonstrates multimodal diagnostics and monitoring of patients with socially significant pathologies.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3207
Author(s):  
Kumaresan Sakthiabirami ◽  
Vaiyapuri Soundharrajan ◽  
Jin-Ho Kang ◽  
Yunzhi Peter Yang ◽  
Sang-Won Park

The design of zirconia-based scaffolds using conventional techniques for bone-regeneration applications has been studied extensively. Similar to dental applications, the use of three-dimensional (3D) zirconia-based ceramics for bone tissue engineering (BTE) has recently attracted considerable attention because of their high mechanical strength and biocompatibility. However, techniques to fabricate zirconia-based scaffolds for bone regeneration are in a stage of infancy. Hence, the biological activities of zirconia-based ceramics for bone-regeneration applications have not been fully investigated, in contrast to the well-established calcium phosphate-based ceramics for bone-regeneration applications. This paper outlines recent research developments and challenges concerning numerous three-dimensional (3D) zirconia-based scaffolds and reviews the associated fundamental fabrication techniques, key 3D fabrication developments and practical encounters to identify the optimal 3D fabrication technique for obtaining 3D zirconia-based scaffolds suitable for real-world applications. This review mainly summarized the articles that focused on in vitro and in vivo studies along with the fundamental mechanical characterizations on the 3D zirconia-based scaffolds.


2021 ◽  
Author(s):  
Andrew D. Beale ◽  
Priya Crosby ◽  
Utham K. Valekunja ◽  
Rachel S. Edgar ◽  
Johanna E. Chesham ◽  
...  

AbstractCellular circadian rhythms confer daily temporal organisation upon behaviour and physiology that is fundamental to human health and disease. Rhythms are present in red blood cells (RBCs), the most abundant cell type in the body. Being naturally anucleate, RBC circadian rhythms share key elements of post-translational, but not transcriptional, regulation with other cell types. The physiological function and developmental regulation of RBC circadian rhythms is poorly understood, however, partly due to the small number of appropriate techniques available. Here, we extend the RBC circadian toolkit with a novel biochemical assay for haemoglobin oxidation status, termed “Bloody Blotting”. Our approach relies on a redox-sensitive covalent haem-haemoglobin linkage that forms during cell lysis. Formation of this linkage exhibits daily rhythms in vitro, which are unaffected by mutations that affect the timing of circadian rhythms in nucleated cells. In vivo, haemoglobin oxidation rhythms demonstrate daily variation in the oxygen-carrying and nitrite reductase capacity of the blood, and are seen in human subjects under controlled laboratory conditions as well as in freely-behaving humans. These results extend our molecular understanding of RBC circadian rhythms and suggest they serve an important physiological role in gas transport.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Nika Taghdiri ◽  
Kevin R King ◽  
David Calcagno ◽  
Zhenxing Fu ◽  
Kenneth Huang ◽  
...  

Introduction: Tissue macrophages play diverse roles in the cardiovascular system during health and disease. They have diverse functions within tissues, but our understanding of their dynamics is limited because most macrophage characterization assays are destructive and have low temporal resolution. We asked whether these cells are dynamic and interconnected. Methods: Here, we describe experimental and analytical methods for measuring cell dynamics and inferring communication between cells in vitro and in vivo. We created a mouse (Csf1r-Cre x GCaMP5) expressing the Cre-inducible genetically encoded calcium indicator GCaMP5 under the regulation of the innate immune promoter, Csf1r, to non-destructively quantify high-frequency cell dynamics and differentiated them in culture using m-CSF. We developed custom image analysis routines and parameterization strategies for classifying calcium responses. Results: Our studies revealed that calcium reporter BMDMs display minimal fluctuations at baseline but exhibit a dynamic response to immunogenic DNA sensing. DNA-induced isolated cell injury and death, which precipitated cell communication that spread with a velocity of [9μm/s], consistent with an extracellular diffusion mechanism. We developed quantitative image analysis methods that corrected for random calcium fluctuations and identified statistically significant areas of correlated calcium changes suggestive of communication. An analytical pipeline enabled quantification of calcium spike dynamics and correlations of dynamic calcium profiles of single cell sharing a local microenvironment. This resulted in an “improbable synchrony” metric that allowed localization of communication in time and space. We adapted the pipeline for in vivo studies and tested them in a dorsal window chamber model using intravital microscopy. At 2Hz sampling frequency, we identified 27 potential communication events as they responded to complex microenvironmental cues in vivo. Conclusion: The experimental and analytical methods for inferring cell communication provide a new quantitative toolkit for investigating known as-yet undiscovered cell communication pathways.


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