Malaria Parasites and Life Cycles with Reference to Chemotherapy

1972 ◽  
pp. 5-9
Keyword(s):  
Life Cycles ◽  
Malaria Parasites

Polysaccharides in the different stages of the life-cycles of certain sporozoa

Parasitology ◽  
1960 ◽  
Vol 50 (3-4) ◽  
pp. 509-514 ◽  
Author(s):  
B. Dasgupta
Keyword(s):  
Positive Reaction ◽  
Life Cycles ◽  
Negative Reaction ◽  
Malaria Parasites ◽  
Residual Mass ◽  
Strong Positive Reaction ◽  
Residual Masses

Glycogen proved to be absent in the malaria parasites (Plasmodium and Hepatocystis) by applying cytochemical methods; while in the piroplasms (Theileria and Babesia), and in Hepatozoon glycogen could be demonstrated by using the same methods. A strong positive reaction for polysaccharides was obtained in the residual masses of Hepatozoon sciuri, and H. balfouri; while a negative reaction was obtained in the residual mass of Plasmodium. A positive reaction for polysaccharides was obtained in the following structures: the wall of the oocysts of Plasmodium, the gametocyte capsules of Hepatozoon sciuri and Hepatozoon sp., the sporoblast capsule of H. sciuri, and the polar areas of the gametocyte of H. balfouri.

scholarly journals Activation of Anopheles stephensi Pantothenate Kinase and Coenzyme A Biosynthesis Reduces Infection with Diverse Plasmodium Species in the Mosquito Host

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 807
Author(s):  
Raquel M. Simão-Gurge ◽  
Neha Thakre ◽  
Jessica Strickland ◽  
Jun Isoe ◽  
Lillian R. Delacruz ◽  
...  
Keyword(s):  
Small Molecule ◽  
Malaria Parasite ◽  
Coenzyme A ◽  
Plasmodium Species ◽  
Plasmodium Yoelii ◽  
Life Cycles ◽  
Parasite Infection ◽  
Malaria Parasites ◽  
Pantothenate Kinase ◽  
Parasite Plasmodium

Malaria parasites require pantothenate from both human and mosquito hosts to synthesize coenzyme A (CoA). Specifically, mosquito-stage parasites cannot synthesize pantothenate de novo or take up preformed CoA from the mosquito host, making it essential for the parasite to obtain pantothenate from mosquito stores. This makes pantothenate utilization an attractive target for controlling sexual stage malaria parasites in the mosquito. CoA is synthesized from pantothenate in a multi-step pathway initiated by the enzyme pantothenate kinase (PanK). In this work, we manipulated A. stephensi PanK activity and assessed the impact of mosquito PanK activity on the development of two malaria parasite species with distinct genetics and life cycles: the human parasite Plasmodium falciparum and the mouse parasite Plasmodium yoelii yoelii 17XNL. We identified two putative A. stephensi PanK isoforms encoded by a single gene and expressed in the mosquito midgut. Using both RNAi and small molecules with reported activity against human PanK, we confirmed that A. stephensi PanK manipulation was associated with corresponding changes in midgut CoA levels. Based on these findings, we used two small molecule modulators of human PanK activity (PZ-2891, compound 7) at reported and ten-fold EC50 doses to examine the effects of manipulating A. stephensi PanK on malaria parasite infection success. Our data showed that oral provisioning of 1.3 nM and 13 nM PZ-2891 increased midgut CoA levels and significantly decreased infection success for both Plasmodium species. In contrast, oral provisioning of 62 nM and 620 nM compound 7 decreased CoA levels and significantly increased infection success for both Plasmodium species. This work establishes the A. stephensi CoA biosynthesis pathway as a potential target for broadly blocking malaria parasite development in anopheline hosts. We envision this strategy, with small molecule PanK modulators delivered to mosquitoes via attractive bait stations, working in concert with deployment of parasite-directed novel pantothenamide drugs to block parasite infection in the human host. In mosquitoes, depletion of pantothenate through manipulation to increase CoA biosynthesis is expected to negatively impact Plasmodium survival by starving the parasite of this essential nutrient. This has the potential to kill both wild type parasites and pantothenamide-resistant parasites that could develop under pantothenamide drug pressure if these compounds are used as future therapeutics for human malaria.

Hurdle in taxonomy: A case of malaria parasites and other Haemosporidia

2021 ◽  
Vol 2 (1) ◽  
pp. 40-54
Author(s):  
Fatik Baran Mandal
Keyword(s):  
Applied Sciences ◽  
Biological Sciences ◽  
Molecular Phylogenetics ◽  
Phylogenetic Analyses ◽  
Molecular Taxonomy ◽  
Life Cycles ◽  
Malaria Parasites ◽  
Holistic View

Abstract A crucial progress in taxonomy matches with the growth of various branches of biological sciences. This validates the taxonomic positions of many organisms. Haemoproteus, Leucocytozoon and Plasmodium, the members of the Haemosporidia, are the well recognized parasitic genera. Revisiting the progress in animal taxonomy appears to be important to evaluate our studies. Haemosporidia being microscopic, their taxonomy specially the morphotaxonomy has sometimes created confusion. Therefore, analysis of progression of the taxonomy of the avian Haemosporidia demands special attention. Modern phylogenetic analyses revealed a wealth of information, which is undoubtedly useful for protozoology and other related sciences. Techniques of molecular taxonomy are applied to draw the phylogeny covering members of Haemosporidia. The study of the life cycles of both hosts and parasites are absorbing. Besides, analysis of their evolution through molecular phylogenetics appears to be vital in studying haemosporidians and to gain insight for basic and applied sciences. This article examines the potential of molecular phylogenetics in refining systematics of avian Haemosporidia and to explain a holistic view of the group.

scholarly journals Roles and Cellular Localization of GBP2 and NAB2 During the Blood Stage of Malaria Parasites

2021 ◽  
Vol 11 ◽  
Author(s):  
Mamoru Niikura ◽  
Toshiyuki Fukutomi ◽  
Jiro Mitobe ◽  
Fumie Kobayashi
Keyword(s):  
Cellular Localization ◽  
Rna Binding ◽  
Binding Protein ◽  
Mrna Export ◽  
Nuclear Periphery ◽  
Adaptor Protein ◽  
Life Cycles ◽  
Asexual Development ◽  
Malaria Parasites ◽  
Female Gametocyte

The quality control and export of mRNA by RNA-binding proteins are necessary for the survival of malaria parasites, which have complex life cycles. Nuclear poly(A) binding protein 2 (NAB2), THO complex subunit 4 (THO4), nucleolar protein 3 (NPL3), G-strand binding protein 2 (GBP2) and serine/arginine-rich splicing factor 1 (SR1) are involved in nuclear mRNA export in malaria parasites. However, their roles in asexual and sexual development, and in cellular localization, are not fully understood. In this study using the rodent malaria parasite, Plasmodium berghei, we found that NAB2 and SR1, but not THO4, NPL3 or GBP2, played essential roles in the asexual development of malaria parasites. By contrast, GBP2 but not NPL3 was involved in male and female gametocyte production. THO4 was involved in female gametocyte production, but had a lower impact than GBP2. In this study, we focused on GBP2 and NAB2, which play important roles in the sexual and asexual development of malaria parasites, respectively, and examined their cellular localization. GBP2 localized to both the nucleus and cytoplasm of malaria parasites. Using immunoprecipitation coupled to mass spectrometry (IP-MS), GBP2 interacted with the proteins ALBA4, DOZI, and CITH, which play roles in translational repression. IP-MS also revealed that phosphorylated adapter RNA export protein (PHAX) domain-containing protein, an adaptor protein for exportin-1, also interacted with GBP2, implying that mRNA export occurs via the PHAX domain-containing protein pathway in malaria parasites. Live-cell fluorescence imaging revealed that NAB2 localized at the nuclear periphery. Moreover, IP-MS indicated that NAB2 interacted with transportin. RNA immunoprecipitation coupled to RNA sequencing revealed that NAB2 bound directly to 143 mRNAs, including those encoding 40S and 60S ribosomal proteins. Our findings imply that malaria parasites use an evolutionarily ancient mechanism conserved throughout eukaryotic evolution.

Lipids in different stages of the life cycles of malaria parasites and some other sporozoa

Parasitology ◽  
1960 ◽  
Vol 50 (3-4) ◽  
pp. 501-508 ◽  
Author(s):  
B. Dasgupta
Keyword(s):  
Life Cycles ◽  
Sudan Dyes ◽  
Malaria Parasites ◽  
Lipid Material ◽  
Vertebrate Hosts ◽  
Eimeria Stiedae

Lipid material occurs in the oocysts of Plasmodium in the form of small Sudano-phil granules, which appear to increase in size with the growth of the parasite. A diffuse Sudanophil material also appears at a later stage.Phospholipid occurs at a certain stage of the oocyst, but later disappears altogether. It appears more quickly in some oocysts than in the others, found in the same infected gut.The pre-erythrocytic schizonts of P. cynomolgi are found to contain abundant lipid material.The erythrocytic stages of Plasmodium and Hepatocystis cannot be stained with the Sudan dyes, but the gametocytes of Hepatozoon infecting the blood corpuscles of the vertebrate hosts are found to contain abundant Sudanophil material.Sudanophil material can be detected in the unsporulated oocysts of Eimeria stiedae, but not in the sporulated ones.

scholarly journals Recurrent bottlenecks in the malaria life cycle obscure signals of positive selection

Parasitology ◽  
2014 ◽  
Vol 142 (S1) ◽  
pp. S98-S107 ◽  
Author(s):  
HSIAO-HAN CHANG ◽  
DANIEL L. HARTL
Keyword(s):  
Life Cycle ◽  
Positive Selection ◽  
Frequency Spectrum ◽  
Population Genetic ◽  
Vaccine Development ◽  
Selective Advantage ◽  
Life Cycles ◽  
Malaria Parasites ◽  
Complex Life Cycles ◽  
Site Frequency Spectrum

SUMMARYDetecting signals of selection in the genome of malaria parasites is a key to identify targets for drug and vaccine development. Malaria parasites have a unique life cycle alternating between vector and host organism with a population bottleneck at each transition. These recurrent bottlenecks could influence the patterns of genetic diversity and the power of existing population genetic tools to identify sites under positive selection. We therefore simulated the site-frequency spectrum of a beneficial mutant allele through time under the malaria life cycle. We investigated the power of current population genetic methods to detect positive selection based on the site-frequency spectrum as well as temporal changes in allele frequency. We found that a within-host selective advantage is difficult to detect using these methods. Although a between-host transmission advantage could be detected, the power is decreased when compared with the classical Wright–Fisher (WF) population model. Using an adjusted null site-frequency spectrum that takes the malaria life cycle into account, the power of tests based on the site-frequency spectrum to detect positive selection is greatly improved. Our study demonstrates the importance of considering the life cycle in genetic analysis, especially in parasites with complex life cycles.

THE CONCEPT OF AUTONOMOUS SYSTEMS IN INDUSTRY 4.0

2019 ◽  
Vol 12 (1) ◽  
pp. 77-87
Author(s):  
György Kovács ◽  
Rabab Benotsmane ◽  
László Dudás
Keyword(s):  
Industry 4.0 ◽  
Intelligent Systems ◽  
Autonomous Systems ◽  
Essential Element ◽  
Industrial Sector ◽  
Life Cycles ◽  
Multi Agent Systems ◽  
New Paradigm ◽  
Intelligent Machines ◽  
Digital Network

Recent tendencies – such as the life-cycles of products are shorter while consumers require more complex and more unique final products – poses many challenges to the production. The industrial sector is going through a paradigm shift. The traditional centrally controlled production processes will be replaced by decentralized control, which is built on the self-regulating ability of intelligent machines, products and workpieces that communicate with each other continuously. This new paradigm known as Industry 4.0. This conception is the introduction of digital network-linked intelligent systems, in which machines and products will communicate to one another in order to establish smart factories in which self-regulating production will be established. In this article, at first the essence, main goals and basic elements of Industry 4.0 conception is described. After it the autonomous systems are introduced which are based on multi agent systems. These systems include the collaborating robots via artificial intelligence which is an essential element of Industry 4.0.

Multiple-source Record Linkage in a Rural Industrial Community, 1680–1820

1994 ◽  
Vol 6 (3) ◽  
pp. 133-142 ◽  
Author(s):  
Steve King
Keyword(s):  
Early Modern ◽  
Large Scale ◽  
Social Economic ◽  
Life Cycles ◽  
Multiple Source ◽  
Demographic Analysis ◽  
Ordinary People ◽  
Industrial Community ◽  
The Social ◽  
Broad Outline

Re-creating the social, economic and demographic life-cycles of ordinary people is one way in which historians might engage with the complex continuities and changes which underlay the development of early modern communities. Little, however, has been written on the ways in which historians might deploy computers, rather than card indexes, to the task of identifying such life cycles from the jumble of the sources generated by local and national administration. This article suggests that multiple-source linkage is central to historical and demographic analysis, and reviews, in broad outline, some of the procedures adopted in a study which aims at large scale life cycle reconstruction.

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