scholarly journals STUDIES ON MALARIAL PARASITES

1946 ◽  
Vol 84 (6) ◽  
pp. 583-606 ◽  
Author(s):  
Quentin M. Geiman ◽  
Christian B. Anfinsen ◽  
Ralph W. McKee ◽  
Richard A. Ormsbee ◽  
Eric G. Ball

1. Methods of recovering adequate amounts of Plasmodium knowlesi from the monkey (Macaca, mulatta) for biochemical studies and in vitro cultivation are described. Concentrates of red blood cells parasitized with P. knowlesi can be obtained by differential sedimentation of parasitized blood because of physical and chemical changes produced by the parasites in the host cell and the plasma of the blood. 2. Two different techniques, the rocker-dilution and the rocker-perfusion methods, are described for the cultivation of malarial parasites. Details of the apparatus, assembly, and sterilization are given, as well as methods of counting and evaluating parasites. 3. In a series of 235 control experiments for 20 to 24 hours using three types of apparatus, the average rate of multiplication was 3.9. Each technique has specific value for studying the various aspects of metabolism, nutrition, and the action of antimalarial drugs.

1986 ◽  
Vol 81 (2) ◽  
pp. 165-170 ◽  
Author(s):  
T. Fandeur ◽  
J. P. Dedet

The in vitro growth and multiplication of the erythrocytic stages of Plasmodium falciparum within Saimiri sciureus (squirrel monkey) red blood cells have been studied. Various parameters, such as the origin of the red blood cells and serum supplement, nature of the buffer, influence of the final pH of the medium, role of proteose peptone and glucose addition, were investigated. The selection of the best culture conditions led to the obtention of a reproducible in vitro growth of two parasite cycles in Saimiri erythrocytes, which is an useful achievement for in vitro studies. Our failure to establish a continuous culture line for longer than 19 days, could be explained by a dramatic increasing of osmotic fragility of the Saimiri red blood cells related to their small size.


Nature ◽  
1959 ◽  
Vol 184 (4704) ◽  
pp. 2017-2018 ◽  
Author(s):  
MASAKATSU HORIKAWA ◽  
YUKIAKI KURODA

Author(s):  
Balogun Islamiat D ◽  
Inabo Helen I ◽  
Ella Elijah E

The efficacy of current or any intended antimalarial can only be resolute by cultivation and susceptibility studies. The aim of this research was to cultivate Plasmodium falciparum in vitro and comparing the antiplasmodial effects of standard antimalarial medications including herbaceous preparation. Asymptomatic pupils attending some schools in Zaria, Kaduna state, Nigeria were recruited into this research and blood samples were collected from them. Microscopy was done after thin and thick blood films were prepared and stained. The antiplasmodial activities of antimalarial drugs as well as herbal preparation were determined after the successful culturing of red blood cells in the Jatropha curcas medium.The phytochemical constituents of the herbs that made up the concoction were determined. The incidence of asymptomatic Plasmodium infection amongst school kids was 17.5%. There was no statistical association of location, gender and age with the obtained prevalence. Presence of alkaloids was observed in every plant screened while the same was also observed for tannins except in Enantia chloranta.Steroids and phlobatanins were observed in Citrus aurantifolia while there was presence of saponins in all the plant extracts except Cymbopogbon citratus. All the plants except Enantia chloranta contained flavonoids. There was presence of terpenoids in all screened plants except Azadirachta indica and Cymbopogbon citratus while cardiac glycosides were found in every plant except Magnifera indica and Enantia chloranta. Results obtained from the in vitro cultivation of the Plasmodium falciparum with Athemether/lumefanthrine, amodiaquine and herbal concoction showed average percentage parasite inhibition of 80%, 37.8% and 38.6% respectively. This implies that Arthemether/lumefanthrine was capable of inhibiting the growth of the parasite best. The herbal concoction also inhibited growth (38.6% inhibition). There is need for additional investigation on a wider variety of plants to explore their antiplasmodial activities since there is evidence that it works, and it is quite available and affordable.


2019 ◽  
Author(s):  
Renugah Naidu ◽  
Trang TT Chu ◽  
Jaishree Tripathi ◽  
Yang Hu ◽  
Gowtham Subramanian ◽  
...  

AbstractPlasmodia are host-specific, both at the organism and cellular levels. During asexual development, Plasmodium spp. infect cells of erythroid lineage, with an overall propensity towards reticulocytes. This applies to even Plasmodium (P.) falciparum, the most common causative agent of human malaria, implications of which remain unexplored. Herein, for the first time, we characterize the developmental stages and features of P. falciparum cultured in vitro in young reticulocytes (CD71+) in comparison to standard normocyte (CD71-) cultures. We demonstrate that there are notable differences in the patterns of invasion, development and sensitivity to potent antimalarials (such as artemisinin and dihydroartemisinin) for parasites residing in CD71+ reticulocytes. Through a transcriptomic approach, we report that P. falciparum parasites are able to sense the host cell environment, and calibrate their metabolic and host cell remodelling pathways through differential gene expression. These results form an exciting avenue on which hitherto unexplored interactions between Plasmodium spp and different stages of host red blood cells could be investigated in the broader contexts of drug resistance, host tropism and zoonosis.Author SummaryParasites causing malaria infect red blood cells for development and proliferation during asexual development. This asexual erythrocytic stage determines higher parasite densities and eventual disease manifestation. Although the most virulent species of Plasmodium infecting humans known as Plasmodium falciparum is able to infect red blood cells of all ages, these parasites show a preference for younger blood cells. Of note, the biochemical and biophysical properties of young and adult red blood cells vary significantly. Herein, we undertook a comparative profiling of invasion process, parasite development and drug response of Plasmoddium falciparum in two host cells: young red blood cells (reticulocytes) and mature red blood cells (normocytes). We demonstrate that P. falciparum infects human reticulocytes with higher affinity and demonstrate differential sensitivity to drugs such as artemisinin while they reside within reticulocytes. Furthermore, we show that P. falciparum is able to detect differences in host environment and adapt to it by changing the expression of genes required for host cell remodelling.


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).


1977 ◽  
Vol 37 (01) ◽  
pp. 073-080 ◽  
Author(s):  
Knut Gjesdal ◽  
Duncan S. Pepper

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.


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