scholarly journals Mechanisms Involved in the Persistence of Babesia canis Infection in Dogs

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 94 ◽  
Author(s):  
Schetters
Keyword(s):  
Endothelial Cells ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Infected Erythrocyte ◽  
Clinical Signs ◽  
Coagulation System ◽  
Blood Capillary ◽  
Babesia Canis ◽  
Large Numbers ◽  
Erythrocyte Surface

Dogs that are infected with Babesia canis parasites usually show severe clinical signs, yet often very few parasites are detectable in the blood circulation. The results showed that large numbers of B. canis-infected red blood cells accumulate in the microvasculature of infected subjects. The initial process leading to the attachment of infected erythrocytes to the endothelial cells of small capillaries (sequestration) appears to involve the interaction of parasite molecules at the erythrocyte surface with ligands on the endothelial cells. Since parasites continue to develop in the sequestered erythrocyte, it would be expected that the infected erythrocyte is destroyed when the mature parasites escape the host cell, which would make it hard to explain accumulation of infected erythrocytes at the initial site of attachment. Apparently, additional processes are triggered that lead to consolidation of parasite sequestration. One possible explanation is that after initial attachment of an infected erythrocyte to the wall of a blood capillary, the coagulation system is involved in the trapping of infected and uninfected erythrocytes. The data further suggest that newly formed parasites subsequently infect normal red blood cells that are also trapped in the capillary, which finally leads to capillaries that appear to be loaded with infected erythrocytes.

scholarly journals In Vivo Removal of Malaria Parasites From Red Blood Cells Without Their Destruction in Acute Falciparum Malaria

Blood ◽  
1997 ◽  
Vol 90 (5) ◽  
pp. 2037-2040 ◽  
Author(s):  
Brian J. Angus ◽  
Kesinee Chotivanich ◽  
Rachanee Udomsangpetch ◽  
Nicholas J. White
Keyword(s):  
Red Blood Cells ◽  
Falciparum Malaria ◽  
Surface Antigen ◽  
Blood Cells ◽  
Malaria Infection ◽  
Infected Erythrocyte ◽  
Intracellular Parasites ◽  
Erythrocyte Surface

Abstract During acute falciparum malaria infection, red blood cells (RBC) containing abundant ring-infected erythrocyte surface antigen (Pf 155 or RESA), but no intracellular parasites, are present in the circulation. These RESA-positive parasite negative RBC are not seen in parasite cultures in vitro. This indicates that in acute falciparum malaria there is active removal of intraerythrocytic parasites by a host mechanism in vivo (probably the spleen) without destruction of the parasitized RBC. This may explain the observed disparity between the drop in hematocrit and decrease in parasite count in some hyperparasitemic patients. The fate of these “once-parasitized” RBC in vivo is not known.

Pathologic Mechanobiological Interactions Between Red Blood Cells and Endothelial Cells Directly Induce Vasculopathy in Iron Deficiency Anemia

2021 ◽  
Author(s):  
Christina Caruso ◽  
Meredith E. Fay ◽  
Xiaopo Cheng ◽  
Alan Y. Liu ◽  
Sunita I. Park ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Iron Deficiency ◽  
Red Blood Cells ◽  
Iron Deficiency Anemia ◽  
Blood Cells ◽  
Deficiency Anemia

scholarly journals Cytoadherence between endothelial cells andP. falciparum infected and noninfected normal and thalassemic red blood cells

2006 ◽  
Vol 70B (6) ◽  
pp. 432-442 ◽  
Author(s):  
P. Butthep ◽  
S. Wanram ◽  
K. Pattanapanyasat ◽  
P. Vattanaviboon ◽  
S. Fucharoen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Red Blood Cells ◽  
Blood Cells

Phagocytosis of Foreign Red Blood Cells by the Reticulo-Endothelial System

1957 ◽  
Vol 189 (3) ◽  
pp. 520-526 ◽  
Author(s):  
Bernard N. Halpern ◽  
G. Biozzi ◽  
B. Benacerraf ◽  
C. Stiffel
Keyword(s):  
Endothelial Cells ◽  
Red Blood Cells ◽  
Clearance Rate ◽  
Blood Cells ◽  
Red Cell ◽  
Histological Evidence ◽  
Specific Antibodies ◽  
Cell Counts ◽  
India Ink ◽  
Reticulo Endothelial System

The clearance rate of nucleated pigeon erythrocytes injected intravenously into mice and rats has been calculated either by routine differential red cell counts or by measuring the radioactivity of the erythrocytes tagged with P32. Histological evidence is given that the foreign erythrocytes are phagocytized by the reticulo-endothelial cells of the liver and spleen. The clearance rate of the foreign erythrocytes, which measures the speed of the phagocytosis, follows in mice a regular exponential function similar to this previously established for other colloids. No spontaneous antibodies to pigeon erythrocytes could be detected in mice. The rapid and complex clearance rate of pigeon erythrocytes observed in rats is related to the existence of spontaneous specific antibodies. The simultaneous injection of pigeon erythrocytes and of India ink into mice, both phagocytized by the RE cells, results in a competition between the two substances in favor of the smaller particles of carbon.

scholarly journals Fine Structure of the Red Pulp of the Spleen in Hereditary Spherocytosis

Blood ◽  
1972 ◽  
Vol 39 (1) ◽  
pp. 81-98 ◽  
Author(s):  
ZELMA MOLNAR ◽  
HENRY RAPPAPORT
Keyword(s):  
Endothelial Cells ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Hereditary Spherocytosis ◽  
Probable Mechanism ◽  
Hemoglobin Content ◽  
Sinus Endothelial Cells ◽  
In Transit ◽  
Conventional Light Microscopy ◽  
Red Pulp

Abstract The spleens from two children and one adult with hereditary spherocytosis were studied in the electron microscope. Stagnation of the erythrocytes within the splenic cords is attributable to their lack of plasticity as evidenced by the absence of bilobed, tailed, or squeezed forms in transit through the walls of the sinuses. In contrast to the sections studied by conventional light microscopy, the splenic sinuses in hereditary spherocytosis were not "empty," but contained red blood cells, the majority of which had lost their hemoglobin content. Cordal macrophages were increased in all three cases and were abundant in the splenic cords of the adult patient, causing a further impediment to the rapid passage of erythrocytes. Macrophages, and, to a lesser degree, sinus endothelial cells contained the products of hemoglobin breakdown. The macrophages showed active erythrophagocytosis. Sinus endothelial cells rarely contained intact red blood cells, but showed pronounced pinocytotic activity, a probable mechanism of hemoglobin incorporation. Platelets within the endothelial cells of the sinuses were much more frequently seen in the three cases of hereditary spherocytosis than in control spleens. The presence of ferritin in platelets suggests that they too may play a role in clearing the end products of hemolysis from the spleen.

The development and pathogenesis of Leucocytozoon simondi in Canada and domestic geese in Algonquin Park, Ontario

1976 ◽  
Vol 54 (5) ◽  
pp. 634-643 ◽  
Author(s):  
Sherwin S. Desser ◽  
Andrée K. Ryckman
Keyword(s):  
Red Blood Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Primary Infection ◽  
Clinical Signs ◽  
Peripheral Circulation ◽  
Branta Canadensis ◽  
Canada Geese ◽  
Severe Anemia ◽  
Branta Canadensis Interior

The development of Leucocytozoon simondi was studied in naturally and experimentally infected Branta canadensis maxima, Branta canadensis interior, and Anser domesticus. The number of mature round gametocytes in the peripheral blood of the Canada geese increased between days 9 and 15 post exposure (PE) and decreased rapidly thereafter. Mean peak parasitemias recorded on day 13 PE were (per 1000 red blood cells (RBC)): 8 gametocytes in B.c. maxima, 16 gametocytes in B.c. interior, and 17 gametocytes in A. domesticus. About 3 weeks PE, gametocytes disappeared from the peripheral circulation and were not observed again during the autumn, winter, and spring in birds kept in the laboratory.Haematocrit determinations in the Canada geese revealed a low fluctuating anemia during the primary infection which subsided by day 21 PE. A more severe anemia was recorded in A. domesticus with a mean low packed RBC value of about 18% on day 11 PE. Immature and mature hepatic schizonts were observed in the Canada and domestic geese between days 3 and 8 PE. Neither megaloschizonts nor elongate gametocytes were seen. Clinical signs, pathology, and mortality commonly associated with L. simondi infection in ducks were not observed. Hypotheses are advanced to explain reports of severe pathogenesis associated with L. simondi infections in Canada geese in other localities.

Establishment of a murine model of cerebral malaria in KunMing mice infected with Plasmodium berghei ANKA

Parasitology ◽  
2016 ◽  
Vol 143 (12) ◽  
pp. 1672-1680 ◽  
Author(s):  
YAN DING ◽  
WENYUE XU ◽  
TAOLI ZHOU ◽  
TAIPING LIU ◽  
HONG ZHENG ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Cerebral Malaria ◽  
Plasmodium Berghei ◽  
Blood Cells ◽  
Mononuclear Cells ◽  
Clinical Signs ◽  
Necrosis Factor Alpha ◽  
Experimental Cerebral Malaria ◽  
Km Mice

SUMMARYMalaria remains one of the most devastating diseases. Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection resulting in high mortality and morbidity worldwide. Analysis of precise mechanisms of CM in humans is difficult for ethical reasons and animal models of CM have been employed to study malaria pathogenesis. Here, we describe a new experimental cerebral malaria (ECM) model with Plasmodium berghei ANKA infection in KunMing (KM) mice. KM mice developed ECM after blood-stage or sporozoites infection, and the development of ECM in KM mice has a dose-dependent relationship with sporozoites inoculums. Histopathological findings revealed important features associated with ECM, including accumulation of mononuclear cells and red blood cells in brain microvascular, and brain parenchymal haemorrhages. Blood–brain barrier (BBB) examination showed that BBB disruption was present in infected KM mice when displaying clinical signs of CM. In vivo bioluminescent imaging experiment indicated that parasitized red blood cells accumulated in most vital organs including heart, lung, spleen, kidney, liver and brain. The levels of inflammatory cytokines interferon-gamma, tumour necrosis factor-alpha, interleukin (IL)-17, IL-12, IL-6 and IL-10 were all remarkably increased in KM mice infected with P. berghei ANKA. This study indicates that P. berghei ANKA infection in KM mice can be used as ECM model to extend further research on genetic, pharmacological and vaccine studies of CM.

Computational Model of Human Capillary Hydrodynamics

2016 ◽  
Author(s):  
Peter W. Windes ◽  
Danesh K. Tafti ◽  
Bahareh Behkam
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Present Model ◽  
Plasma Layer ◽  
Relative Viscosity ◽  
Cell Deformation ◽  
Analytical Models ◽  
Blood Capillary

The present work lays out an accurate, three-dimensional computational fluid dynamics (CFD) model of a human blood capillary. This model is composed of red blood cells and blood plasma inside a cylindrical section of a capillary. The plasma flow is resolved using an incompressible Navier-Stokes solver. At the level of capillaries, red blood cells must be individually handled to correctly resolve the hydrodynamics in the system. They cannot be lumped in with the plasma and considered as a non-Newtonian suspension because of the relative scale of the capillaries and the blood cells. Red blood cells act as highly deformable, fluid filled vesicles which readily deform from their typical biconcave shape when passing through narrow capillaries. In the present model, the deformed shape of red blood cells is predicted using a combination of analytical models and experimental data on cell deformation. The cell volume, cell surface area, and plasma layer thickness are found to be the key parameters which define red blood cell deformation in capillaries. The red blood cells are imposed in the flow using the immersed boundary method (IBM). To save computational resources while still yielding an accurate model, the deformed shape of each red blood cell is calculated once prior to running the simulation and then held constant throughout the run. In order to validate the model, two parameters — apparent relative viscosity and hematocrit ratio — were examined. The present model shows good comparison to experimental values for both these parameters.

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