Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.
A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.
A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.
Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.
Parasitic Sensitivity Tests
An alkaloid derived from the bark of the cinchona tree. It is used as an antimalarial drug, and is the active ingredient in extracts of the cinchona that have been used for that purpose since before 1633. Quinine is also a mild antipyretic and analgesic and has been used in common cold preparations for that purpose. It was used commonly and as a bitter and flavoring agent, and is still useful for the treatment of babesiosis. Quinine is also useful in some muscular disorders, especially nocturnal leg cramps and myotonia congenita, because of its direct effects on muscle membrane and sodium channels. The mechanisms of its antimalarial effects are not well understood.
Merozoite Surface Protein 1
Papua New Guinea
A country consisting of the eastern half of the island of New Guinea and adjacent islands, including New Britain, New Ireland, the Admiralty Islands, and New Hanover in the Bismarck Archipelago; Bougainville and Buka in the northern Solomon Islands; the D'Entrecasteaux and Trobriand Islands; Woodlark (Murua) Island; and the Louisiade Archipelago. It became independent on September 16, 1975. Formerly, the southern part was the Australian Territory of Papua, and the northern part was the UN Trust Territory of New Guinea, administered by Australia. They were administratively merged in 1949 and named Papua and New Guinea, and renamed Papua New Guinea in 1971.
Pregnancy Complications, Parasitic
A condition characterized by somnolence or coma in the presence of an acute infection with PLASMODIUM FALCIPARUM (and rarely other Plasmodium species). Initial clinical manifestations include HEADACHES; SEIZURES; and alterations of mentation followed by a rapid progression to COMA. Pathologic features include cerebral capillaries filled with parasitized erythrocytes and multiple small foci of cortical and subcortical necrosis. (From Adams et al., Principles of Neurology, 6th ed, p136)
Life Cycle Stages
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 126.96.36.199.
The constant presence of diseases or infectious agents within a given geographic area or population group. It may also refer to the usual prevalence of a given disease with such area or group. It includes holoendemic and hyperendemic diseases. A holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). A hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. (Last, A Dictionary of Epidemiology, 3d ed, p53, 78, 80)
Inhibitory Concentration 50
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A republic of southeast Asia, northwest of Thailand, long familiar as Burma. Its capital is Yangon, formerly Rangoon. Inhabited by people of Mongolian stock and probably of Tibetan origin, by the 3d century A.D. it was settled by Hindus. The modern Burmese state was founded in the 18th century but was in conflict with the British during the 19th century. Made a crown colony of Great Britain in 1937, it was granted independence in 1947. In 1989 it became Myanmar. The name comes from myanma, meaning the strong, as applied to the Burmese people themselves. (From Webster's New Geographical Dictionary, 1988, p192 & Room, Brewer's Dictionary of Names, 1992, p367)
An aminoquinoline that is given by mouth to produce a radical cure and prevent relapse of vivax and ovale malarias following treatment with a blood schizontocide. It has also been used to prevent transmission of falciparum malaria by those returning to areas where there is a potential for re-introduction of malaria. Adverse effects include anemias and GI disturbances. (From Martindale, The Extra Pharmacopeia, 30th ed, p404)
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Amino Acid Sequence
The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.
A country in western Africa, east of MAURITANIA and south of ALGERIA. Its capital is Bamako. From 1904-1920 it was known as Upper Senegal-Niger; prior to 1958, as French Sudan; 1958-1960 as the Sudanese Republic and 1959-1960 it joined Senegal in the Mali Federation. It became an independent republic in 1960.
A republic stretching from the Indian Ocean east to New Guinea, comprising six main islands: Java, Sumatra, Bali, Kalimantan (the Indonesian portion of the island of Borneo), Sulawesi (formerly known as the Celebes) and Irian Jaya (the western part of New Guinea). Its capital is Djakarta. The ethnic groups living there are largely Chinese, Arab, Eurasian, Indian, and Pakistani; 85% of the peoples are of the Islamic faith.
Membrane Transport Proteins
Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)
Folic Acid Antagonists
Multidrug Resistance-Associated Proteins
A sequence-related subfamily of ATP-BINDING CASSETTE TRANSPORTERS that actively transport organic substrates. Although considered organic anion transporters, a subset of proteins in this family have also been shown to convey drug resistance to neutral organic drugs. Their cellular function may have clinical significance for CHEMOTHERAPY in that they transport a variety of ANTINEOPLASTIC AGENTS. Overexpression of proteins in this class by NEOPLASMS is considered a possible mechanism in the development of multidrug resistance (DRUG RESISTANCE, MULTIPLE). Although similar in function to P-GLYCOPROTEINS, the proteins in this class share little sequence homology to the p-glycoprotein family of proteins.
The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.
Enzyme-Linked Immunosorbent Assay
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Drug Therapy, Combination
A French overseas department on the northeast coast of South America. Its capital is Cayenne. It was first settled by the French in 1604. Early development was hindered because of the presence of a penal colony. The name of the country and the capital are variants of Guyana, possibly from the native Indian Guarani guai (born) + ana (kin), implying a united and interrelated race of people. (From Webster's New Geographical Dictionary, 1988, p418 & Room, Brewer's Dictionary of Names, 1992, p195)
Sequence Analysis, DNA
One of the Indian Ocean Islands off the southeast coast of Africa. Its capital is Antananarivo. It was formerly called the Malagasy Republic. Discovered by the Portuguese in 1500, its history has been tied predominantly to the French, becoming a French protectorate in 1882, a French colony in 1896, and a territory within the French union in 1946. The Malagasy Republic was established in the French Community in 1958 but it achieved independence in 1960. Its name was changed to Madagascar in 1975. (From Webster's New Geographical Dictionary, 1988, p714)
Drug Resistance, Multiple
Duffy Blood-Group System
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Sequence Homology, Amino Acid
A republic in western Africa, south of NIGER and between TOGO and NIGERIA. Its capital is Porto-Novo. It was formerly called Dahomey. In the 17th century it was a kingdom in the southern area of Africa. Coastal footholds were established by the French who deposed the ruler by 1892. It was made a French colony in 1894 and gained independence in 1960. Benin comes from the name of the indigenous inhabitants, the Bini, now more closely linked with southern Nigeria (Benin City, a town there). Bini may be related to the Arabic bani, sons. (From Webster's New Geographical Dictionary, 1988, p136, 310 & Room, Brewer's Dictionary of Names, 1992, p60)
Derivatives of chondroitin which have a sulfate moiety esterified to the galactosamine moiety of chondroitin. Chondroitin sulfate A, or chondroitin 4-sulfate, and chondroitin sulfate C, or chondroitin 6-sulfate, have the sulfate esterified in the 4- and 6-positions, respectively. Chondroitin sulfate B (beta heparin; DERMATAN SULFATE) is a misnomer and this compound is not a true chondroitin sulfate.
The collective name for the islands of the Pacific Ocean northeast of Australia, including NEW CALEDONIA; VANUATU; New Hebrides, Solomon Islands, Admiralty Islands, Bismarck Archipelago, FIJI, etc. Melanesia (from the Greek melas, black + nesos, island) is so called from the black color of the natives who are generally considered to be descended originally from the Negroid Papuans and the Polynesians or Malays. (From Webster's New Geographical Dictionary, 1988, p748 & Room, Brewer's Dictionary of Names, 1992, p344)
Sensitivity and Specificity
A group of Indian Ocean Islands, the islands of Great Comoro, Anjouan, Mayotte, and Moheli, lying between northeast Mozambique and northwest Madagascar. The capital is Moroni. In 1914 they became a colony attached to Madagascar administratively and were made a French overseas territory in 1947. Except for Mayotte which remained French, Comoros became an independent republic in 1975. Comoros represents the Arabic qamar, moon, said by some scholars to be linked with the mystical Mountains of the Moon said to be somewhere in equatorial Africa. (From Webster's New Geographical Dictionary, 1988, p283 & Room, Brewer's Dictionary of Names, 1992, p122)
A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).
A sulfone active against a wide range of bacteria but mainly employed for its actions against MYCOBACTERIUM LEPRAE. Its mechanism of action is probably similar to that of the SULFONAMIDES which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with PYRIMETHAMINE in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)
Glucosephosphate Dehydrogenase Deficiency
Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.
Protein Structure, Tertiary
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing Fc receptors. Rosette formation can be used to identify specific populations of these cells.
Polymorphism, Restriction Fragment Length
Diagnostic Tests, Routine
RNA, Ribosomal, 18S
Organisms, Genetically Modified
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Democratic Republic of the Congo
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
Reagent Kits, Diagnostic
Optical mapping of Plasmodium falciparum chromosome 2. (1/7602)Detailed restriction maps of microbial genomes are a valuable resource in genome sequencing studies but are toilsome to construct by contig construction of maps derived from cloned DNA. Analysis of genomic DNA enables large stretches of the genome to be mapped and circumvents library construction and associated cloning artifacts. We used pulsed-field gel electrophoresis purified Plasmodium falciparum chromosome 2 DNA as the starting material for optical mapping, a system for making ordered restriction maps from ensembles of individual DNA molecules. DNA molecules were bound to derivatized glass surfaces, cleaved with NheI or BamHI, and imaged by digital fluorescence microscopy. Large pieces of the chromosome containing ordered DNA restriction fragments were mapped. Maps were assembled from 50 molecules producing an average contig depth of 15 molecules and high-resolution restriction maps covering the entire chromosome. Chromosome 2 was found to be 976 kb by optical mapping with NheI, and 946 kb with BamHI, which compares closely to the published size of 947 kb from large-scale sequencing. The maps were used to further verify assemblies from the plasmid library used for sequencing. Maps generated in silico from the sequence data were compared to the optical mapping data, and good correspondence was found. Such high-resolution restriction maps may become an indispensable resource for large-scale genome sequencing projects. (+info)
8-Aminoquinolines active against blood stage Plasmodium falciparum in vitro inhibit hematin polymerization. (2/7602)From the Walter Reed Army Institute of Research (WRAIR) inventory, thirteen 8-aminoquinoline analogs of primaquine were selected for screening against a panel of seven Plasmodium falciparum clones and isolates. Six of the 13 8-aminoquinolines had average 50% inhibitory concentrations between 50 and 100 nM against these P. falciparum clones and were thus an order of magnitude more potent than primaquine. However, excluding chloroquine-resistant clones and isolates, these 8-aminoquinolines were all an order of magnitude less potent than chloroquine. None of the 8-aminoquinolines was cross resistant with either chloroquine or mefloquine. In contrast to the inactive primaquine prototype, 8 of the 13 8-aminoquinolines inhibited hematin polymerization more efficiently than did chloroquine. Although alkoxy or aryloxy substituents at position 5 uniquely endowed these 13 8-aminoquinolines with impressive schizontocidal activity, the structural specificity of inhibition of both parasite growth and hematin polymerization was low. (+info)
Alternative oxidase inhibitors potentiate the activity of atovaquone against Plasmodium falciparum. (3/7602)Recent evidence suggests that the malaria parasite Plasmodium falciparum utilizes a branched respiratory pathway including both a cytochrome chain and an alternative oxidase. This branched respiratory pathway model has been used as a basis for examining the mechanism of action of two antimalarial agents, atovaquone and proguanil. In polarographic assays, atovaquone immediately reduced the parasite oxygen consumption rate in a concentration-dependent manner. This is consistent with its previously described role as an inhibitor of the cytochrome bc1 complex. Atovaquone maximally inhibited the rate of P. falciparum oxygen consumption by 73% +/- 10%. At all atovaquone concentrations tested, the addition of the alternative oxidase inhibitor, salicylhydroxamic acid, resulted in a further decrease in the rate of parasite oxygen consumption. At the highest concentrations of atovaquone tested, the activities of salicylhydroxamic acid and atovaquone appear to overlap, suggesting that at these concentrations, atovaquone partially inhibits the alternative oxidase as well as the cytochrome chain. Drug interaction studies with atovaquone and salicylhydroxamic acid indicate atovaquone's activity against P. falciparum in vitro is potentiated by this alternative oxidase inhibitor, with a sum fractional inhibitory concentration of 0.6. Propyl gallate, another alternative oxidase inhibitor, also potentiated atovaquone's activity, with a sum fractional inhibitory concentration of 0.7. Proguanil, which potentiates atovaquone activity in vitro and in vivo, had a small effect on parasite oxygen consumption in polarographic assays when used alone or in the presence of atovaquone or salicylhydroxamic acid. This suggests that proguanil does not potentiate atovaquone by direct inhibition of either branch of the parasite respiratory chain. (+info)
Comparison of in vivo and in vitro tests of resistance in patients treated with chloroquine in Yaounde, Cameroon. (4/7602)The usefulness of an isotopic in vitro assay in the field was evaluated by comparing its results with the therapeutic response determined by the simplified WHO in vivo test in symptomatic Cameroonian patients treated with chloroquine. Of the 117 enrolled patients, 102 (87%) completed the 14-day follow-up, and 95 isolates obtained from these patients (46 children, 49 adults) yielded an interpretable in vitro test. A total of 57 of 95 patients (60%; 28 children and 29 adults) had an adequate clinical response with negative smears (n = 46) or with an asymptomatic parasitaemia (n = 11) on day 7 and/or day 14. The geometric mean 50% inhibitory concentration of the isolates obtained from these patients was 63.3 nmol/l. Late and early treatment failure was observed in 29 (30.5%) and 9 (9.5%) patients, respectively. The geometric mean 50% inhibitory concentrations of the corresponding isolates were 173 nmol/l and 302 nmol/l. Among the patients responding with late and early treatment failure, five isolates and one isolate, respectively, yielded a discordant result (in vivo resistance and in vitro sensitivity). The sensitivity, specificity, and predictive value of the in vitro test to detect chloroquine-sensitive cases was 67%, 84% and 86%, respectively. There was moderate concordance between the in vitro and in vivo tests (kappa value = 0.48). The in vitro assay agrees relatively well with the therapeutic response and excludes several host factors that influence the results of the in vivo test. However, in view of some discordant results, the in vitro test cannot substitute for in vivo data on therapeutic efficacy. The only reliable definition of "resistance" in malaria parasites is based on clinical and parasitological response in symptomatic patients, and the in vivo test provides the standard method to determine drug sensitivity or resistance as well as to guide national drug policies. (+info)
Intraerythrocytic Plasmodium falciparum expresses a high affinity facilitative hexose transporter. (5/7602)Asexual stages of Plasmodium falciparum cause severe malaria and are dependent upon host glucose for energy. We have identified a glucose transporter of P. falciparum (PfHT1) and studied its function and expression during parasite development in vitro. PfHT1 is a saturable, sodium-independent, and stereospecific transporter, which is inhibited by cytochalasin B, and has a relatively high affinity for glucose (Km = 0.48 mM) when expressed in Xenopus laevis oocytes. Competition experiments with glucose analogues show that hydroxyl groups at positions C-3 and C-4 are important for ligand binding. mRNA levels for PfHT1, assessed by the quantitative technique of tandem competitive polymerase chain reaction, are highest during the small ring stages of infection and lowest in gametocytes. Confocal immunofluorescence microscopy localizes PfHT1 to the region of the parasite plasma membrane and not to host structures. These findings have implications for development of new drug targets in malaria as well as for understanding of the pathophysiology of severe infection. When hypoglycemia complicates malaria, modeling studies suggest that the high affinity of PfHT1 is likely to increase the relative proportion of glucose taken up by parasites and thereby worsen the clinical condition. (+info)
Complexity of Plasmodium falciparum infections is consistent over time and protects against clinical disease in Tanzanian children. (6/7602)The complexity of Plasmodium falciparum populations in 21 children was studied in repetitive samples over 4 years in an area of Tanzania where the organism is holoendemic. Genotyping was done by a polymerase chain reaction method that targets three highly polymorphic regions of the merozoite surface protein (MSP) 1 block 2, MSP 2, and the glutamine-rich protein. Eight children were repeatedly parasitemic, 5 had scanty parasitemias, and 8 were consistently nonparasitemic. Varying numbers of genotypes were detected in the parasitemic children, but the multiplicity of infection was significantly constant within each child. The children with frequent parasitemias experienced fewer clinical episodes during the study period than those without parasitemias. There was also a tendency for children with more complex infections to experience fewer episodes. The children had consistent parasitologic profiles over the 4 years. Although few subjects were studied and the results will require confirmation, the results suggest that asymptomatic (especially polyclonal) P. falciparum infection protects against clinical disease from new infections. (+info)
HLA class II factors associated with Plasmodium falciparum merozoite surface antigen allele families. (7/7602)In Plasmodium falciparum malaria, certain human leukocyte antigens (HLA) and the parasite's merozoite surface antigens 1 and 2 (MSA-1, MSA-2) have been shown to influence the course of the infection. This report is on associations of distinct HLA factors with the occurrence of particular MSA families in a group of patients with either severe or mild P. falciparum malaria in Gabon. Different distributions of HLA-DPB1 alleles were found in the 2 groups. DR *04 alleles were observed more frequently among patients with severe malaria. Several alleles of different loci were associated with distinct MSA allele families. In addition, carriers of the amino acid methionine at position 11 of the DPA1 allele were more often infected by MSA-1 K1 parasites and less frequently by MSA-1 RO33 parasites. Furthermore, associations of HLA factors with polyclonal infections were found. (+info)
Comparison of a parasite lactate dehydrogenase-based immunochromatographic antigen detection assay (OptiMAL) with microscopy for the detection of malaria parasites in human blood samples. (8/7602)Microscopic examination of blood smears remains the gold standard for malaria diagnosis, but is labor-intensive and requires skilled operators. Rapid dipstick technology provides a potential alternative. A study was conducted in The Gambia to compare the performance of OptiMAL, an immunochromatographic antigen detection assay for the diagnosis of malaria using parasite lactate dehydrogenase, against standard microscopy in patients with suspected malaria. For initial diagnosis of Plasmodium falciparum, irrespective of stage, this assay had a sensitivity of 91.3%, a specificity of 92%, a positive predictive value of 87.2%, and a negative predictive value of 94.7%. The sensitivity of the test decreased markedly at parasitemias < 0.01%. This assay can be used for the diagnosis of malaria in areas where microscopy is not available and for urgent malaria diagnosis at night and at weekends, when routine laboratories are closed and when relatively inexperienced microscopists may be on duty. (+info)
Plasmodium falciparum erythrocyte membrane protein 1 - Wikipedia
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a family of proteins present on the membrane surface of red blood cells (RBCs or erythrocytes) that are infected by the malarial parasite Plasmodium falciparum. PfEMP1 is synthesized during the parasites blood stage (erythrocytic schizogony) inside the RBC, during which the clinical symptoms of falciparum malaria are manifested. Acting as both an antigen and adhesion protein, it is thought to play a key role in the high level of virulence associated with P. falciparum. It was discovered in 1984 when it was reported that infected RBCs had unusually large-sized cell membrane proteins, and these proteins had antibody-binding (antigenic) properties. An elusive protein, its chemical structure and molecular properties were revealed only after a decade, in 1995. It is now established that there is not one but a large family of PfEMP1 proteins, genetically regulated (encoded) by a group of about 60 genes called var. Each P. falciparum is ...
Mitochondrial DNA of the human malarial parasite Plasmodium falciparum - Lancaster EPrints
Covalently closed circular DNA molecules were isolated from Plasmodium falciparum total DNA by isopycnic centrifugation in CsCl gradients containing either ethidium bromide or 2,6-diamidino-2-phenylindole. The circular molecules had an average contour length of 11.1 +/- 0.5 micron, similar to the analogous molecules previously isolated from the simian malaria parasite P. knowlesi. Both circular molecules shared considerable sequence homology and conserved restriction sites. The nucleotide sequence of one 936 bp fragment of the P. falciparum molecule was determined and identified, by a data base homology search, as part of a mitochondrial small rRNA subunit, thus confirming the mitochondrial origin of the circular DNAs of both malarial species.. ...
Molecular epidemiology of malaria in Cameroon. XVIII. Polymorphisms of the Plasmodium falciparum merozoite surface antigen-2...
TY - JOUR. T1 - Molecular epidemiology of malaria in Cameroon. XVIII. Polymorphisms of the Plasmodium falciparum merozoite surface antigen-2 gene in isolates from symptomatic patients. AU - Basco, Leonardo K.. AU - Tahar, Rachida. AU - Escalante, Ananias. PY - 2004/3. Y1 - 2004/3. N2 - Merozoite surface antigen-2 (MSA-2) is a polymorphic genetic marker that is highly discriminatory for characterizing Plasmodium falciparum field isolates. Genetic diversity of isolates obtained from symptomatic patients residing in Yaounde, Cameroon was analyzed by an allele-specific polymerase chain reaction and direct sequencing of amplification products. Of 137 isolates, 25 (18%) had only FC27-type alleles, 40 (29%) had only 3D7-type alleles, and 72 (53%) had multiple parasite populations with both alleles. Of 295 fragments, 145 (49.2%) and 150 (50.8%) belonged to FC27 and 3D7 alleles, respectively. There were 23 different MSA-2 alleles (10 FC27-type and 13 3D7-type that yielded 44 different combinations in ...
Recombinant Duffy binding-like-alpha domains of Plasmodium falciparum erythrocyte membrane protein 1 elicit antibodies in rats...
Link to Pubmed [PMID] - 12802682. Parasitol. Res. 2003 Aug;90(6):467-72. Plasmodium falciparum parasites remodel the surface of human erythrocytes on invasion by the insertion of parasite-derived proteins in knob-like protrusions. P. falciparum erythrocyte membrane protein 1 (PfEMP-1), a variant surface antigen, has been shown to be anchored in these knobs and mediates adhesion to various host endothelial receptors. These proteins also undergo clonal antigenic variation as a means of immune evasion. Duffy binding-like-alpha(DBL-alpha) domain together with the cysteine-rich interdomain region form the head structure of the PfEMP1 molecule. In this report, we used ten different recombinant DBL-alpha fusion proteins expressed in Escherichia coli to generate antibodies in experimental animals. Five out of ten recombinant DBL-alpha fusion proteins were immunogenic and induced antibodies that reacted with conserved peptides derived from PfEMP1. Indirect immunofluorescence assay was used to localise ...
DNA cloning of Plasmodium falciparum circumsporozoite gene: amino acid sequence of repetitive epitope | Science
A clone of complementary DNA encoding the circumsporozoite (CS) protein of the human malaria parasite Plasmodium falciparum has been isolated by screening an Escherichia coli complementary DNA library with a monoclonal antibody to the CS protein. The DNA sequence of the complementary DNA insert encodes a four-amino acid sequence: proline-asparagine-alanine-asparagine, tandemly repeated 23 times. The CS beta-lactamase fusion protein specifically binds monoclonal antibodies to the CS protein and inhibits the binding of these antibodies to native Plasmodium falciparum CS protein. These findings provide a basis for the development of a vaccine against Plasmodium falciparum malaria. ...
Chondroitin sulfate proteoglycan but not hyaluronic acid is the receptor for the adherence of Plasmodium falciparum-infected...
TY - JOUR. T1 - Chondroitin sulfate proteoglycan but not hyaluronic acid is the receptor for the adherence of Plasmodium falciparum-infected erythrocytes in human placenta, and infected red blood cell adherence up-regulates the receptor expression. AU - Muthusamy, Arivalagan. AU - Achur, Rajeshwara N.. AU - Valiyaveettil, Manojkumar. AU - Botti, John J.. AU - Taylor, Diane W.. AU - Leke, Rose F.. AU - Gowda, D. Channe. PY - 2007/6. Y1 - 2007/6. N2 - A low-sulfated chondroitin sulfate proteoglycan (CSPG) has been shown to be the receptor for the adherence of Plasmodium falciparum-infected red blood cells (IRBCs) in human placenta. Recently, hyaluronic acid (HA) has been suggested as an additional receptor even though IRBC binding to HA and the presence of HA at locations where IRBCs adhere in the placenta have not been established. In this study, we investigated whether HA is also a receptor for IRBC binding. IRBCs from infected placentas as well as those from different laboratory strains could ...
Development of cultured Plasmodium falciparum blood-stage malaria cell banks for early phase in vivo clinical trial assessment...
The ability to undertake controlled human malaria infection (CHMI) studies for preliminary evaluation of malaria vaccine candidates and anti-malaria drug efficacy has been limited by the need for access to sporozoite infected mosquitoes, aseptic, purified, cryopreserved sporozoites or blood-stage malaria parasites derived ex vivo from malaria infected individuals. Three different strategies are described for the manufacture of clinical grade cultured malaria cell banks suitable for use in CHMI studies. Good Manufacturing Practices (GMP)-grade Plasmodium falciparum NF54, clinically isolated 3D7, and research-grade P. falciparum 7G8 blood-stage malaria parasites were cultured separately in GMP-compliant facilities using screened blood components and then cryopreserved to produce three P. falciparum blood-stage malaria cell banks. These cell banks were evaluated according to specific criteria (parasitaemia, identity, viability, sterility, presence of endotoxin, presence of mycoplasma or other viral agents
anti-Plasmodium falciparum Schizont Infected Rbcs antibody [11B7] | GeneTex
Plasmodium falciparum Schizont Infected Rbcs antibody [11B7] for ICC/IF. Anti-Plasmodium falciparum Schizont Infected Rbcs mAb (GTX39330) is tested in Plasmodium falciparum samples. 100% Ab-Assurance.
Rosette formation in Plasmodium falciparum isolates and anti-rosette activity of sera from Gambians with cerebral or...
The ability of Plasmodium falciparum-infected red blood cells (RBC) to form spontaneous erythrocyte rosettes was studied in 130 fresh isolates from Gambian children with cerebral or uncomplicated malaria from August to November 1990. All isolates (24 of 24) from patients with cerebral malaria formed rosettes, but only 61 of 106 isolates from children with uncomplicated malaria formed rosettes. The mean rate of rosette formation in isolates from children with cerebral malaria (28.3%) was significantly greater than that in isolates from children with uncomplicated malaria (8.5%). Giant rosettes were more frequently formed in isolates from patients with cerebral malaria than in those from patients with uncomplicated malaria. Sera of children with cerebral disease generally lacked anti-rosette activity, while many sera from children with uncomplicated malaria showed strong anti- rosette activity when tested against the patients ow parasites. Some sera that were devoid of autologous rosette-disrupting
Seroepidemiologic Studies of Humoral Immune Response to the Plasmodium falciparum Antigens in Thailand | The American Journal...
Abstract We have investigated seroreactivity against Plasmodium falciparum crude parasite antigens, the P. falciparum ring-infected erythrocyte surface antigen (Pf155/RESA), as well as against two synthetic peptides (EENV)6 and (EENVEHDA)3 that represent important epitopes of Pf155/RESA. The study population consisted of 421 children and adult Thais living in an area with moderate malaria transmission. We related these serologic findings to some important epidemiologic baseline data collected in the study area. The parasite rate in study subjects was 18.76%. Sixty-two percent were seropositive to crude P. falciparum antigens, 30.3% to the Pf155/RESA antigen, 23.05% to (EENV)6, and 20.17% to (EENVEHDA)3. Antibody responses to crude P. falciparum antigens and to Pf155/RESA were age dependent and increased with exposure. There was evidence that Pf155/RESA antibodies might play a role in protective immunity in this population. Since Pf155/RESA is a potential vaccine candidate antigen, the information
PfSETvs methylation of histone H3K36 represses virulence genes in Plasmodium falciparum. - RIIP - Réseau International des...
The variant antigen Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), which is expressed on the surface of P. falciparum-infected red blood cells, is a critical virulence factor for malaria. Each parasite has 60 antigenically distinct var genes that each code for a different PfEMP1 protein. During infection the clonal parasite population expresses only one gene at a time before switching to the expression of a new variant antigen as an immune-evasion mechanism to avoid the host antibody response. The mechanism by which 59 of the 60 var genes are silenced remains largely unknown. Here we show that knocking out the P. falciparum variant-silencing SET gene (here termed PfSETvs), which encodes an orthologue of Drosophila melanogaster ASH1 and controls histone H3 lysine 36 trimethylation (H3K36me3) on var genes, results in the transcription of virtually all var genes in the single parasite nuclei and their expression as proteins on the surface of individual infected red blood cells. PfSETvs
Sporogonic Development of Cultured Plasmodium Falciparum in Six Species of Laboratory-Reared Anopheles Mosquitoes | The...
Abstract Sporogonic development of cultured Plasmodium falciparum was compared in six species of Anopheles mosquitoes. A reference species, A. gambiae, was selected as the standard for comparison. Estimates of absolute densities were determined for each lifestage. From these data, four aspects of parasite population dynamics were analyzed quantitatively: 1) successive losses in abundance as parasites developed from gametocyte to ookinete to oocyst stages, 2) oocyst production of sporozoites, 3) correlation between various lifestage parameters, and 4) parasite distribution. Parasite populations in A. gambiae incurred a 316-fold loss in abundance during the transition from macrogametocyte to ookinete stage, a 100-fold loss from ookinete to oocyst stage, yielding a total loss of approximately 31,600-fold (i.e., losses are multiplicative). Comparative susceptibilities in order were A. freeborni ≫ A. gambiae, A. arabiensis, A. dirus > A. stephensi, A. albimanus. The key transition(s) determining overall
Plasmodium falciparum malaria parasite var gene expression is modified by host antibodies: longitudinal evidence from...
The PfEMP1 family of Plasmodium falciparum antigens play a key role in pathogenesis of severe malaria through their insertion into the surface of parasite infected erythrocytes, and adhesion to host cells. Previous studies have suggested that parasites expressing PfEMP1 subclasses group A and DC8, associated with severe malaria, may have a growth advantage in immunologically naïve individuals. However, this idea has not been tested in longitudinal studies. Here we assessed expression of the var genes encoding PfEMP1, in parasites sampled from volunteers with varying prior exposure to malaria, following experimental infection by sporozoites (PfSPZ). Using qPCR, we tested for associations between the expression of various var subgroups in surviving parasite populations from each volunteer and 1) the levels of participants antibodies to infected erythrocytes before challenge infection and 2) the apparent in vivo parasite multiplication rate. We show that 1) expression of var genes encoding for group A
Allelic variants of the Plasmodium falciparum merozoite surface antigen 2 (MSA-2) in a geographically restricted area of Irian...
Blood samples were collected from 12 residents of 4 villages in the Oksibil area of Irian Jaya. Eleven patients were positive for Plasmodium falciparum infection as evidenced by successful amplification of the MSA-2 gene by the polymerase chain reaction. Two patients showed evidence of infection by 2 strains of Plasmodium falciparum. All MSA-2 genes were completely sequenced and all could be assigned to one of the two major allelic families of MSA-2, however all MSA-2 gene sequences differed from previously described alleles. Five new allelic forms were identified, one of which was present in 8 of the 11 patients. Within small natural populations of P. falciparum, it appears that variation in MSA-2 approximates that seen world-wide. All samples were also analysed by hybridisation of amplified DNA to family specific probes and all samples hybridised to known probes. Our results demonstrate that there is a degree of microheterogeneity of MSA-2 that is undetectable by hybridisation studies alone ...
Erythrocyte-binding antigens of Plasmodium falciparum are targets of human inhibitory antibodies and function to evade...
Abs that inhibit Plasmodium falciparum invasion of erythrocytes form an important component of human immunity against malaria, but key target Ags are largely unknown. Phenotypic variation by P. falciparum mediates the evasion of inhibitory Abs, contributing to the capacity of P. falciparum to cause repeat and chronic infections. However, Ags involved in mediating immune evasion have not been defined, and studies of the function of human Abs are limited. In this study, we used novel approaches to determine the importance of P. falciparum erythrocyte-binding Ags (EBAs), which are important invasion ligands, as targets of human invasion-inhibitory Abs and define their role in contributing to immune evasion through variation in function. We evaluated the invasion-inhibitory activity of acquired Abs from malaria-exposed children and adults from Kenya, using P. falciparum with disruption of genes encoding EBA140, EBA175, and EBA181, either individually or combined as EBA140/EBA175 or EBA175/EBA181 double
Structural insights into chondroitin sulphate A binding Duffy-binding-like domains from Plasmodium falciparum : implications...
Placental malaria is typified by selective clustering of Plasmodium falciparum in the intervillous blood spaces of the placenta. Sequestration of malaria parasite in the human placenta is mediated by interactions between chondroitin sulphate A (CSA) on the syncytiotrophoblasts and proteins expressed on the surface of infected human erythrocytes. Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) encoded by the var2CSA gene is believed to be the main parasite ligand for CSA-mediated placental binding. Extensive sequence and structure comparisons of the various CSA-binding and non-binding DBL domains from the var2CSA gene from A4 and 3D7 strains of P. falciparum were performed. Three-dimensional structural models of various DBL domains were built and analysed with a view to assessing conservation of CSA interaction sites across various DBL domains. Each of the six DBL domains from var2CSA are likely to retain the disulfide linkages evident from previously published DBL domain crystal structures
Controlled Human Malaria Infection by Intradermal Injection of Plasmodium Falciparum Sporozoites in Tanzanian Adults - Tabular...
Controlled human malaria infection (CHMI) is a critical component of malaria vaccine and drug development and is an important element of any strategy for accelerating the development of new tools for malaria control, elimination and eradication. Until now, CHMI has been performed in malaria naïve subjects from countries not endemic for malaria using both infectious mosquitoes and recently, aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ). Results from these studies report significant infection success in all study subjects and an excellent safety profile.. The conduct of CHMI studies in malaria endemic populations will allow early understanding of responses to new vaccines and drugs in endemic country populations and for direct comparisons between previously exposed and non-exposed individuals. Performing CHMI studies in malaria endemic countries will reduce associated costs, speed-up the process of testing and substantially contribute to the acceleration of the ...
New Plasmodium falciparum finding Genes parameters for FGENESH
New Plasmodium falciparum finding Genes parameters for FGENESH the program with parameters for major model organisms, viruses and bacteria is available for on line usage at: http://www.softberry.com/berry.phtml?topic=gfind Method description: A new parameter set for gene prediction Plasmodium falciparum is developed for FGENESH program. Accuracy of prediction of Plasmodium falciparum protein coding genes is about 98% on the nucleotide level. Exact exon prediction accuracy ~80%. The FGENESH algorithm is based on pattern recognition of different types of signals and Markov chain models of coding regions. Optimal combination of these features is then found by dynamic programming and a set of gene models is constructed along given sequence. FGENESH is the fastest and most accurate ab initio gene prediction program available. Fgenesh output: fgenesh Wed Oct 30 23:05:15 EST 2002 FGENESH 1.1 Prediction of potential genes in Plasmodium genomic DNA Time : Wed Oct 30 23:05:15 2002 Seq name: MAL7P1.27 chr7 ...
The Plasmodium falciparum blood stages acquire factor H family proteins to evade destruction by human complement. - Leibniz...
Rosa TF, Flammersfeld A, Ngwa CJ, Kiesow M, Fischer R, Zipfel PF, Skerka C, Pradel G (2016) The Plasmodium falciparum blood stages acquire factor H family proteins to evade destruction by human complement. Cell Microbiol 18(4), 573-590. PubMed ...
Chromosome 2 sequence of the human malaria parasite Plasmodium falciparum. | J. Craig Venter Institute
Chromosome 2 of Plasmodium falciparum was sequenced; this sequence contains 947,103 base pairs and encodes 210 predicted genes. In comparison with the Saccharomyces cerevisiae genome, chromosome 2 has a lower gene density, introns are more frequent, and proteins are markedly enriched in nonglobular domains. A family of surface proteins, rifins, that may play a role in antigenic variation was identified. The complete sequencing of chromosome 2 has shown that sequencing of the A+T-rich P. falciparum genome is technically feasible.. ...
A preliminary evaluation of a recombinant circumsporozoite protein vaccine against Plasmodium falciparum malaria<...
TY - JOUR. T1 - A preliminary evaluation of a recombinant circumsporozoite protein vaccine against Plasmodium falciparum malaria. AU - Stoute, José A.. AU - Slaoui, Moncef. AU - Heppner, D. Gray. AU - Momin, Patricia. AU - Kester, Kent E.. AU - Desmons, Pierre. AU - Wellde, Bruce T.. AU - Garçon, Nathalie. AU - Krzych, Urszula. AU - Marchand, Martine. AU - Ballou, W. Ripley. AU - Cohen, Joe D.. PY - 1997/1/9. Y1 - 1997/1/9. N2 - Background: The candidate vaccines against malaria are poorly immunogenic and thus have been ineffective in preventing infection. We developed a vaccine based on the circumsporozoite protein of Plasmodium falciparum that incorporates adjuvants selected to enhance the immune response. Methods: The antigen consists of a hybrid in which the circumsporozoite protein fused to hepatitis B surface antigen (HBsAg) is expressed together with unfused HBsAg. We evaluated three formulations of this antigen in an unblinded trial in 46 subjects who had never been exposed to malaria. ...
CD4 T cells from malaria-nonexposed individuals respond to the CD36-Binding Domain of Plasmodium falciparum erythrocyte...
We have studied the human CD4 T cell response to a functionally conserved domain of Plasmodium falciparum erythrocyte membrane protein-1, cysteine interdomain region-1alpha (CIDR-1alpha). Responses to CIDR-1alpha were striking in that both exposed and nonexposed donors responded. The IFN-gamma response to CIDR-1alpha in the nonexposed donors was partially independent of TCR engagement of MHC class II and peptide. Contrastingly, CD4 T cell and IFN-gamma responses in malaria-exposed donors were MHC class II restricted, suggesting that the CD4 T cell response to CIDR-1alpha in malaria semi-immune adults also has a TCR-mediated component, which may represent a memory response. Dendritic cells isolated from human peripheral blood were activated by CIDR-1alpha to produce IL-12, IL-10, and IL-18. IL-12 was detectable only between 6 and 12 h of culture, whereas the IL-10 continued to increase throughout the 24-h time course. These data strengthen previous observations that P. falciparum interacts directly with
Characterization of the accessible genome in the human malaria parasite Plasmodium falciparum. | PubFacts
Human malaria is a devastating disease and a major cause of poverty in resource-limited countries. To develop and adapt within hosts Plasmodium falciparum undergoes drastic switches in gene expression. To identify regulatory regions in the parasite genome, we performed genome-wide profiling of chromatin accessibility in two culture-adapted isogenic subclones at four developmental stages during the intraerythrocytic cycle by using the Assay for Transposase-Accessible Chromatin by sequencing (ATAC-seq). Tn5 transposase hypersensitivity sites (THSSs) localize preferentially at transcriptional start sites (TSSs). Chromatin accessibility by ATAC-seq is predictive of active transcription and of the levels of histone marks H3K9ac and H3K4me3. Our assay allows the identification of novel regulatory regions including TSS and enhancer-like elements. We show that the dynamics in the accessible chromatin profile matches temporal transcription during development. Motif analysis of stage-specific ATAC-seq ...
Relationship between maternally derived anti-Plasmodium falciparum antibodies and risk of infection and disease in infants...
In areas where Plasmodium falciparum is endemic, immunoglobulin G is acquired by the fetus in utero, mainly during the third trimester of pregnancy. The potential protective effect of transferred anti-P. falciparum maternal antibodies was examined in a longitudinal study of 100 infants from birth to 1 year of age. The probability of acquiring a P. falciparum infection and developing an episode of clinical malaria was determined in relation to the P. falciparum-specific antibody level of the infant at birth against P. falciparum schizont antigen or recombinant merozoite surface protein MSP1(19) antigen. The risk of acquiring an episode of clinical malaria increased from birth to 6 months of age, after which it decreased. The overall prevalence of P. falciparum parasitemia was highest (48.9%) in the 6-month-old infants. The age-specific hematocrit value showed the lowest mean value (30.2) from 6 to 9 months, and the spleen rate was the highest (69.8%) at the same age. There was a lower risk of ...
Prevalence of K13-propeller gene polymorphisms among Plasmodium falciparum parasites isolated from adult symptomatic patients...
In the absence of an effective vaccine, malaria treatment and eradication is still a challenge in most endemic areas globally. This is especially the case with the current reported emergence of resistance to artemisinin agents in Southeast Asia. This study therefore explored the prevalence of K13-propeller gene polymorphisms among Plasmodium falciparum parasites in northern Uganda. Adult patients (≥18 years) presenting to out-patients department of Lira and Gulu regional referral hospitals in northern Uganda were randomly recruited. Laboratory investigation for presence of plasmodium infection among patients was done using Plasmodium falciparum exclusive rapid diagnostic test, histidine rich protein-2 (HRP2) (Pf). Finger prick capillary blood from patients with a positive malaria test was spotted on a filter paper Whatman no. 903. The parasite DNA was extracted using chelex resin method and sequenced for mutations in K13-propeller gene using Sanger sequencing. PCR DNA sequence products were analyzed
RSpred, a set of Hidden Markov Models to detect and classify the RIFIN and STEVOR proteins of Plasmodium falciparum | BMC...
Many parasites use multicopy protein families to avoid their hosts immune system through a strategy called antigenic variation. RIFIN and STEVOR proteins are variable surface antigens uniquely found in the malaria parasites Plasmodium falciparum and P. reichenowi. Although these two protein families are different, they have more similarity to each other than to any other proteins described to date. As a result, they have been grouped together in one Pfam domain. However, a recent study has described the sub-division of the RIFIN protein family into several functionally distinct groups. These sub-groups require phylogenetic analysis to sort out, which is not practical for large-scale projects, such as the sequencing of patient isolates and meta-genomic analysis. We have manually curated the rif and stevor gene repertoires of two Plasmodium falciparum genomes, isolates DD2 and HB3. We have identified 25% of mis-annotated and ~30 missing rif and stevor genes. Using these data sets, as well as sequences
A Genetic Map and Recombination Parameters of the Human Malaria Parasite Plasmodium falciparum | Science
Genetic investigations of malaria require a genome-wide, high-resolution linkage map of Plasmodium falciparum. A genetic cross was used to construct such a map from 901 markers that fall into 14 inferred linkage groups corresponding to the 14 nuclear chromosomes. Meiotic crossover activity in the genome proved high (17 kilobases per centimorgan) and notably uniform over chromosome length. Gene conversion events and spontaneous microsatellite length changes were evident in the inheritance data. The markers, map, and recombination parameters are facilitating genome sequence assembly, localization of determinants for such traits as virulence and drug resistance, and genetic studies of parasite field populations. ...
Stool microbiota composition is associated with the prospective risk of Plasmodium falciparum infection | MalariaWorld
Background. In humans it is unknown if the composition of the gut microbiota alters the risk of Plasmodium falciparum infection or the risk of developing febrile malaria once P. falciparum infection is established. Here we collected stool samples from a cohort composed of 195 Malian children and adults just prior to an intense P. falciparum transmission season. We assayed these samples using massively parallel sequencing of the 16S ribosomal RNA gene to identify the composition of the gut bacterial communities in these individuals. During the ensuing 6-month P. falciparum transmission season we examined the relationship between the stool microbiota composition of individuals in this cohort and their prospective risk of both P. falciparum infection and febrile malaria.. Results. Consistent with prior studies, stool microbial diversity in the present cohort increased with age, although the overall microbiota profile was distinct from cohorts in other regions of Africa, Asia and North America. ...
Detection of genome-wide polymorphisms in the AT-rich Plasmodium falciparum genome using a high-density microarray | BMC...
Genetic mapping is a powerful method to identify mutations that cause drug resistance and other phenotypic changes in the human malaria parasite Plasmodium falciparum. For efficient mapping of a target gene, it is often necessary to genotype a large number of polymorphic markers. Currently, a community effort is underway to collect single nucleotide polymorphisms (SNP) from the parasite genome. Here we evaluate polymorphism detection accuracy of a high-density tiling microarray with 2.56 million probes by comparing single feature polymorphisms (SFP) calls from the microarray with known SNP among parasite isolates. We found that probe GC content, SNP position in a probe, probe coverage, and signal ratio cutoff values were important factors for accurate detection of SFP in the parasite genome. We established a set of SFP calling parameters that could predict mSFP (SFP called by multiple overlapping probes) with high accuracy (≥ 94%) and identified 121,087 mSFP genome-wide from five parasite isolates
Association of antibodies to Plasmodium falciparum reticulocyte binding protein homolog 5 with protection from clinical malaria...
Emerging evidence suggests that antibodies against merozoite proteins involved in Plasmodium falciparum invasion into the red blood cell (RBC) play an important role in clinical immunity to malaria. The protein family of parasite antigens known as P. falciparum reticulocyte binding protein like homolog (PfRh) is required for RBC invasion. PfRh5 is the only member within the PfRh family that cannot be genetically deleted, suggesting it plays an essential role in parasite survival. This antigen forms a complex with the cysteine-rich P. falciparum Rh5 interacting protein (PfRipr), on the merozoite surface during RBC invasion. The PfRh5 ectodomain sequence and a C-terminal fragment of PfRipr were cloned and expressed in Escherichia coli and baculovirus-infected cells, respectively. Immunization of rabbits with these recombinant proteins induced antibodies able to inhibit growth of various P. falciparum strains. Antibody responses to these proteins were investigated in a treatment re-infection study ...
Early gametocytes of the malaria parasite Plasmodium falciparum specifically remodel the adhesive properties of infected...
In Plasmodium falciparum infections the parasite transmission stages, the gametocytes, mature in 10 days sequestered in internal organs. Recent studies suggest that cell mechanical properties rather than adhesive interactions play a role in sequestration during gametocyte maturation. It remains instead obscure how sequestration is established, and how the earliest sexual stages, morphologically similar to asexual trophozoites, modify the infected erythrocytes and their cytoadhesive properties at the onset of gametocytogenesis. Here, purified P. falciparum early gametocytes were used to ultrastructurally and biochemically analyse parasite-induced modifications on the red blood cell surface and to measure their functional consequences on adhesion to human endothelial cells. This work revealed that stage I gametocytes are able to deform the infected erythrocytes like asexual parasites, but do not modify its surface with adhesive knob structures and associated proteins. Reduced levels of the P. ...
Spread of artemisinin-resistant Plasmodium falciparum in Myanmar: a cross-sectional survey of the K13 molecular marker. |...
BACKGROUND: Emergence of artemisinin resistance in southeast Asia poses a serious threat to the global control of Plasmodium falciparum malaria. Discovery of the K13 marker has transformed approaches to the monitoring of artemisinin resistance, allowing introduction of molecular surveillance in remote areas through analysis of DNA. We aimed to assess the spread of artemisinin-resistant P falciparum in Myanmar by determining the relative prevalence of P falciparum parasites carrying K13-propeller mutations. METHODS: We did this cross-sectional survey at malaria treatment centres at 55 sites in ten administrative regions in Myanmar, and in relevant border regions in Thailand and Bangladesh, between January, 2013, and September, 2014. K13 sequences from P falciparum infections were obtained mainly by passive case detection. We entered data into two geostatistical models to produce predictive maps of the estimated prevalence of mutations of the K13 propeller region across Myanmar. FINDINGS: Overall, ...
Effect of antibodies on the expression of Plasmodium falciparum circumsporozoite protein gene
Antibodies are known to play an important role in the control of malaria infection. Since the early studies demonstrating that antibodies transferred from immune individuals diminish P. falciparum parasitaemia  a lot of effort has been put forward to identify parasite epitopes and mechanisms of action of antibody-mediated immune response to malaria. Besides their role in infection control, antibodies can modulate parasite development in the sporogonic [3 - 5], exoerythrocytic  and erythrocytic  cycle. However, there is almost no information on the effect of antibodies on the expression of Plasmodium immunogenic molecules.. There are evidences that antibodies can interfere with parasite multiplication. An increase on sporozoite number recovered from the salivary glands when mosquitoes were fed on anti-Plasmodium antibodies was observed [3, 4] and IgG isolated from Kenyan immune adults enhanced parasite growth in culture while the serum from which they were isolated had an inhibitory ...
Characterization of yeast artificial chromosomes from Plasmodium falciparum: construction of a stable, representative library...
Molecular genetic studies of the human malaria parasite Plasmodium falciparum have been hampered in part due to difficulties in stably cloning and propagating parasite genomic DNA in bacteria. This is thought to be a result of the unusual A+T bias (|80%) in the parasites DNA. Pulsed-field gel electrophoretic separation of P. falciparum chromosomes has shown that large chromosomal polymorphisms, resulting from the deletion of DNA from chromosome ends, frequently occur. Understanding the biological implications of this chromosomal polymorphism will require the analysis of large regions of genomic, and in particular telomeric, DNA. To overcome the limitations of cloning parasite DNA in bacteria, we have cloned genomic DNA from the P. falciparum strain FCR3 in yeast as artificial chromosomes. A pYAC4 library with an average insert size of approximately 100 kb was established and found to have a three to fourfold redundancy for single-copy genes. Unlike bacterial hosts, yeast stably maintain and propagate
Characterisation of Plasmodium falciparum proteins expressed on infected red blood cell surfaces as potential drug targets for...
The most severe form of malaria in humans is caused by the intracellular parasite Plasmodium falciparum. The African continent bears the greatest burden of malaria with 90% of all malaria deaths occurring in sub-Saharan Africa where the high risk populations include pregnant woman and children under the age of five. Fatal cases of malaria are often a result of the progression of the disease to a life threatening syndrome where intravenous quinine or artesunate are administered as an emergency treatment, however a 15-20% mortality rate is still observed among treated individuals. Pathogenesis of severe malaria is associated with the mature or late trophozoite stage of the parasite s intra-erythrocyte life cycle. At this stage the intracellular parasite expresses parasite derived proteins on the surface of the red blood cell (RBCs) that bind to host endothelial receptors. This cytoadhesion ultimately allows the parasite to multiply unhindered by the host resulting in high parasitaemia levels which ...
Malaria Consortium - Disease control, better health - Containing artemisinin resistant plasmodium falciparum parasite and...
Malaria Consortium - One of the worlds leading non-profit organisations specialising in the prevention, control and treatment of malaria and other communicable diseases among vulnerable populations. - Containing artemisinin resistant plasmodium falciparum parasite and moving toward malaria pre elimination status in cambodia
Plasmodium Falciparum Schizont Infected RBCs Antibody (11B7) [PerCP] (NB100-64491PCP): Novus Biologicals
Mouse Monoclonal Anti-Plasmodium Falciparum Schizont Infected RBCs Antibody (11B7) [PerCP]. Validated: ICC/IF. Tested Reactivity: Protozoa. 100% Guaranteed.
Absence of Antigenic Competition in Aotus Monkeys Immunized With Plasmodium Falciparum DNA Vaccines Delivered as a Mixture
Aotus lemurinus lemurinus monkeys were immunized four times with one of three DNA plasmids expressing important Plasmodium falciparum blood stage vaccine candidate proteins or with a mixture containing all three vaccines. The three vaccines encoded sequences from apical merozoite antigen-1 (AMA-1), …
Plasmodium falciparum Rosette Formation Assay -BIO-PROTOCOL
Rosetting, i.e. the capacity of red blood cells (iRBCs) infected with mature parasite stages to bind two or more uninfected red blood cells (RBCs) is a virulence factor of Plasmodium falciparum. This protocol describes an in vitro assay to monitor rosette formation by P. falciparum-infected red blood cells, including procedures for rosette enrichment, maintenance of rosetting phenotype and assays for rosetting with RBC labeled using lipophilic fluorescent probes.
Identifying Plasmodium falciparum merozoite surface protein 1 variants in children with multiple malaria infections in Kilifi,...
The Plasmodium falciparum Merozoite Surface Protein 1(Pf MSP1), a predominant antigen on the surface of the asexual blood stage of the parasite, plays a role in erythrocyte invasion. It elicits immune responses during exposure to natural P. falciparum infections, hence, it is a potential vaccine candidate. However, its extensive sequence diversity causes antigenic variability. Parasites that express variants other than that targeted by immune protection mounted as a result of a vaccine variant, evade the resultant host immune protection. This compromises the efficacy of allele-specific vaccines formulated to protect against a single variant. Due to this, Pf MSP1 has been extensively studied, including in Kenya. However, the extent of Pf MSP1 diversity in children with multiple infections are unknown in Kilifi which is a moderate to high malaria transmission zone. Parasite genomic DNA was extracted from 421 blood samples in 33 children aged below 5 years who had at least 9 multiple infections. ...
Immunological cross-reactivity of the C-terminal 42-kilodalton fragment of Plasmodium falciparum merozoite surface protein 1...
The roles of allelic and conserved epitopes in vaccine-induced immunity to the C-terminal 42-kDa fragment of the Plasmodium falciparum merozoite surface protein 1 (MSP1) were investigated. The C-terminal fragment of MSP1 was expressed as a baculovirus recombinant protein, BVp42. Rabbits were immunized with BVp42, and antibodies were tested for reactivity to MSP1s of the homologous and heterologous allelic forms, represented by the FUP, FVO, FC27, and Honduras parasite isolates, by enzyme-linked immunosorbent assay and indirect immunofluorescence antibody assay. Despite the fact that allelic sequences accounted for approximately 50% of the BVp42 molecule, anti-BVp42 antibodies cross-reacted extensively with parasites carrying heterologous MSP1 alleles. Enzyme-linked immunosorbent inhibition assays confirmed that an overwhelming majority of the anti-BVp42 antibodies were cross-reactive, suggesting that determinants within conserved block 17 are dominant B-cell epitopes in the anti-BVp42 response. ...
HLA-A alleles differentially associate with severity to Plasmodium falciparum malaria infection in Ibadan, Nigeria |...
Human Leukocyte Antigen (HLA), particularly HLA-B and class II alleles have been differentially associated with disease outcomes in different populations following infection with the malaria Plasmodium falciparum. However, the effect of HLA-A on malaria infection and/or disease is not fully understood. Recently, HLA-A alleles have been suggested to play a role in the outcome of P. falciparum malaria infection in a Malian study. Herein, we investigated the association between HLA-A alleles and the outcome of malaria infection in children in Ibadan southwest Nigeria. HLA-A genotyping was performed on 393 children samples (DNA) using the sequence-based method. We compared genotype and allele frequencies data obtained from these Nigerian children; 176 with asymptomatic malaria infection (controls), 124 with uncomplicated malaria and 93 children with severe malaria (51 severe malarial anaemia and 42 cerebral malaria). We found a high frequency of HLA-A*36:01 (13.5%) in the entire studied population ...
Pilot Study to Estimate the Burden and Distribution of Plasmodium Falciparum Malaria in Kalifabougou, Mali in Preparation for a...
Plasmodium falciparum malaria remains a global public health threat. Leading malaria vaccine candidates confer only partial short-lived protection at best. An understanding of the mechanisms by which humans acquire malaria immunity through repeated P. falciparum infections may aid the development of a malaria vaccine. This pilor study is designed to initiate the epidemiological groundwork for a future prospective cohort study of acquired malaria immunity in Kalifabougou, Mali, a rural village of approximately 5 000 individuals who are exposed to seasonal P. falciparum transmission each year from July through December. This study will estimate the age-stratified point prevalence of P. falciparum infection before the malaria season and at the peak of the 6-month malaria season, and it will estimate the age-stratified incidence of symptomatic p. falciparum infection during the 6-month malaria season. The spatial distribution of asymptomatic P. falciparum infections and incident malaria cases within ...
Functional Comparison of Blood-Stage Plasmodium falciparum Malaria Vaccine Candidate Antigens. - Immunology
The malaria genome encodes over 5,000 proteins and many of these have also been proposed to be potential vaccine candidates, although few of these have been tested clinically. RH5 is one of the leading blood-stage Plasmodium falciparum malaria vaccine antigens and Phase I/II clinical trials of vaccines containing this antigen are currently underway. Its likely mechanism of action is to elicit antibodies that can neutralize merozoites by blocking their invasion of red blood cells (RBC). However, many other antigens could also elicit neutralizing antibodies against the merozoite, and most of these have never been compared directly to RH5. The objective of this study was to compare a range of blood-stage antigens to RH5, to identify any antigens that outperform or synergize with anti-RH5 antibodies. We selected 55 gene products, covering 15 candidate antigens that have been described in the literature and 40 genes selected on the basis of bioinformatics functional prediction. We were able to make 20
In vitro activity of pyronaridine against multidrug-resistant Plasmodium falciparum and Plasmodium vivax. - Nuffield Department...
Pyronaridine, a Mannich base antimalarial, has demonstrated high in vivo and in vitro efficacy against chloroquine-resistant Plasmodium falciparum. Although this drug has the potential to become a prominent artemisinin combination therapy, little is known about its efficacy against drug-resistant Plasmodium vivax. The in vitro antimalarial susceptibility of pyronaridine was assessed in multidrug-resistant P. vivax (n = 99) and P. falciparum (n = 90) isolates from Papua, Indonesia, using a schizont maturation assay. The median 50% inhibitory concentration (IC(50)) of pyronaridine was 1.92 nM (range, 0.24 to 13.8 nM) against P. falciparum and 2.58 nM (range, 0.13 to 43.6 nM) against P. vivax, with in vitro susceptibility correlating significantly with chloroquine, amodiaquine, and piperaquine (r(s) [Spearmans rank correlation coefficient] = 0.45 to 0.62; P | 0.001). P. falciparum parasites initially at trophozoite stage had higher IC(50)s of pyronaridine than those exposed at the ring stage (8.9 nM
Immunoglobulin G subclass-specific responses against Plasmodium falciparum merozoite antigens are associated with control of...
Substantial evidence indicates that antibodies to Plasmodium falciparum merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective immunity from malaria is not known and the factors determining subclass responses in vivo are poorly understood. We examined IgG and IgG subclass responses to the merozoite antigens MSP1-19 (the 19-kDa C-terminal region of merozoite surface protein 1), MSP2 (merozoite surface protein 2), and AMA-1 (apical membrane antigen 1), including different polymorphic variants of these antigens, in a longitudinal cohort of children in Papua New Guinea. IgG1 and IgG3 were the predominant subclasses of antibodies to each antigen, and all antibody responses increased in association with age and exposure without evidence of increasing polarization toward one ...
Safety, immunogenicity, and efficacy of a Plasmodium falciparum vaccine comprising a circumsporozoite protein repeat region...
TY - JOUR. T1 - Safety, immunogenicity, and efficacy of a Plasmodium falciparum vaccine comprising a circumsporozoite protein repeat region peptide conjugated to Pseudomonas aeruginosa toxin A. AU - Fries, L. F.. AU - Gordon, D. M.. AU - Schneider, I.. AU - Beier, J. C.. AU - Long, G. W.. AU - Gross, M.. AU - Que, J. U.. AU - Cryz, S. J.. AU - Sadoff, J. C.. N1 - Copyright: Copyright 2004 Elsevier B.V., All rights reserved.. PY - 1992. Y1 - 1992. N2 - Twenty-one malaria-naive volunteers were immunized with a vaccine consisting of a 22-kDa recombinant peptide (R32LR), derived from the repeat region of Plasmodium falciparum circumsporozoite (CS) protein, covalently coupled to detoxified Pseudomonas aeruginosa toxin A. Nineteen volunteers received a second dose of vaccine at 8 weeks, and eighteen received a third dose at 8 to 12 months. The vaccine was well tolerated, with only one volunteer developing local discomfort and induration at the site of injection which limited function for 48 h. The ...
Biochemical and biophysical analysis of recombinant Plasmodium falciparum chloroquine resistance transporter (pfcrt)
Thesis (Ph.D.)--Georgetown University, 2009.; Includes bibliographical references.; Text (Electronic thesis) in PDF format. Malaria caused by the Apicomplexan parasite Plasmodium falciparum is an alarming health problem due to increasing incidence of deaths and growing resistance to antimalarial drugs such as chloroquine. Chloroquine resistance in P. falciparum is primarily determined by PfCRT (P. falciparum chloroquine resistance transporter), a transmembrane protein localized to the digestive vacuolar membrane of the parasite. Bioinformatic studies by Fidock et al. (2000) and Martin & Kirk (2004) suggested that PfCRT belongs to the drug/metabolite transporter superfamily but its mode of action has not yet been fully established. In order to elucidate the role of PfCRT in chloroquine resistance, chloroquine binding and transport were analyzed using membrane preparations from yeast Pichia pastoris expressing PfCRT, as well as proteoliposomes harboring purified protein.; Chloroquine binding was ...
Murine model for assessment of Plasmodium falciparum transmission-blocking vaccine using transgenic Plasmodium berghei...
TY - JOUR. T1 - Murine model for assessment of Plasmodium falciparum transmission-blocking vaccine using transgenic Plasmodium berghei parasites expressing the target antigen Pfs25. AU - Mlambo, Godfree. AU - Maciel, Jorge. AU - Kumar, Nirbhay. PY - 2008/5. Y1 - 2008/5. N2 - Currently, there is no animal model for Plasmodium falciparum challenge to evaluate malaria transmission-blocking vaccines based on the well-established Pfs25 target antigen. The biological activity of transmission-blocking antibodies is typically assessed using an assay known as the membrane feeding assay (MFA). It is an in vitro method that involves mixing antibodies with cultured P. falciparum gametocytes and feeding them to mosquitoes through an artificial membrane followed by assessment of infection in the mosquitoes. We genetically modified Plasmodium berghei to express Pfs25 and demonstrated that the transgenic parasites (TrPfs25Pb) are susceptible to anti-Pfs25 antibodies during mosquito-stage development. The ...
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A glimpse into the clinical proteome of human malaria parasites Plasmodium falciparum and Plasmodium vivax - [email protected]
Malaria causes a worldwide annual mortality of about a million people.Rapidly evolving drug-resistant species of the parasite have created a pressing need for the identification of new drug targets and vaccine candidates. By developing fractionation protocols to enrich parasites from low-parasitemia patient samples, we have carried out the first ever proteomics analysis of clinical isolates of early stages of Plasmodium falciparum (Pf) and P. vivax. Patient-derived malarial parasites were directly processed and analyzed using shotgun proteomics approach using high-sensitivity MS for protein identification. Our study revealed about 100 parasite-coded gene products that included many known drug targets such as Pf hypoxanthine guanine phosphoribosyl transferase, Pf L-lactate dehydrogenase, and Plasmepsins. In addition,our study reports the expression of several parasite proteins in clinical ring stages that have never been reported in the ring stages of the laboratory-cultivated parasite strain. ...
WHO IRIS: Chloroquine-resistant Plasmodium falciparum at the Tanganyika Planting Company sugar estate, Moshi, Tanzania / by T....
Chloroquine-resistant Plasmodium falciparum at the Tanganyika Planting Company sugar estate, Moshi, Tanzania / by T. K. Mutabingwa, V. A. E. G. Kilimali and W. L. ...
Chronic Plasmodium Falciparum Infections in an Area of Low intensity Malaria Transmission in the Sudan
Chronic Plasmodium falciparum malaria infections in a Sudanese village, in an area of seasonal and unstable malaria transmission, were monitored and genetically characterized to study the in¯uence of persistent infection on the immunology and epidemiology of low endemicity malaria. During the October±December malaria season of 1996, 51 individuals out of a population of 420 had con®rmed and treated P. falciparum malaria in the village of Daraweesh in eastern Sudan. In a cross-sectional survey carried out in December 1996, an additional 6 individuals were found to harbour a microscopically negative but polymerase chain reaction (PCR)-positive P. falciparum infection. On 1 January 1997, a cohort of 43 individuals aged from 9 to 53, recruited from this group of recently malaria-infected individuals agreed to donate fortnightly blood samples for the next 9 months, the ®rst 6 of which constitute the long Sudanese dry season when transmission falls to undetectable levels. Each blood sample was ...
ANALYSIS OF PLASMODIUM FALCIPARUM CHLOROQUINE RESISTANCE TRANSPORTER ISOFORMS
Resistance-conferring PfCRT isoforms (which harbor mutation K76T and are distinguished by 3-8 additional mutations) are believed to confer resistance to the 4-amino quinoline drug chloroquine (CQ) by transporting CQ away from the drugs digestive vacuole (DV) - localized heme target. One theory then is that variable CQ transport catalyzed by different mutant PfCRTs are responsible for the range of CQ sensitivities now found for P. falciparum around the globe. Alternatively, additional mutations in drug- selected parasites may complement PfCRT in conferring a range of resistance phenotypes. In this thesis, I further optimize a convenient method for screening for CQ transport mediated by PfCRT, involving heterologous expression in Saccharomyces cerevisiae. I use this method and other techniques to quantify activity for all currently known naturally occurring PfCRT isoforms. My results show that chlorquine resistance (CQR) in isolates expressing certain PfCRT isoforms likely depends upon additional ...
AID 723630 - Antiplasmodial activity against erythrocyte form of chloroquine-resistant Plasmodium falciparum Dd2 by parasite...
BioAssay record AID 723630 submitted by ChEMBL: Antiplasmodial activity against erythrocyte form of chloroquine-resistant Plasmodium falciparum Dd2 by parasite lactate dehydrogenase assay.
The mechanisms of parasite clearance after antimalarial treatment of Plasmodium falciparum malaria. - Radcliffe Department of...
Studies were conducted to determine how malaria parasites are cleared from the blood after antimalarial treatment. Neither artesunate nor quinine decreased parasitized red cell deformability or increased antibody binding. In acute falciparum malaria, ring-infected erythrocyte surface antigen (RESA) was observed in erythrocytes without malaria parasites (RESA-red blood cell [RBC]), indicating prior parasitization. In uncomplicated malaria, RESA-RBC numbers increased significantly (P=.002) within 24 h of starting artesunate but rose much more slowly (7 days) after quinine treatment. In severe malaria, RESA-RBC increased significantly (P=. 001) within hours of starting artesunate but not with quinine treatment (P=.43). RESA-RBCs were not produced after drug treatment of malaria parasite cultures in vitro. Rapid malaria parasite clearance after treatment with artemisinin derivatives results mainly from the extraction of drug-affected parasites from host erythrocytes-presumably by the spleen. This explains
Invasion of mouse erythrocytes by the human malaria parasite, Plasmodium falciparum. | JEM
Plasmodium falciparum malaria merozoites require erythrocyte sialic acid for optimal invasion of human erythrocytes. Since mouse erythrocytes have the form of sialic acid found on human erythrocytes (N-acetyl neuraminic acid), mouse erythrocytes were tested for invasion in vitro. The Camp and 7G8 strains of P. falciparum invaded mouse erythrocytes at 17-45% of the invasion rate of human erythrocytes. Newly invaded mouse erythrocytes morphologically resembled parasitized human erythrocytes as shown on Giemsa-stained blood films and by electron microscopy. The rim of parasitized mouse erythrocytes contained the P. falciparum 155-kD protein, which is on the rim of ring-infected human erythrocytes. Camp but not 7G8 invaded rat erythrocytes, indicating receptor heterogeneity. These data suggest that it may be possible to adapt the asexual erythrocytic stage of P. falciparum to rodents. The development of a rodent model of P. falciparum malaria could facilitate vaccine development. ...
In vivo transcriptional profiling of Plasmodium falciparum<...
TY - JOUR. T1 - In vivo transcriptional profiling of Plasmodium falciparum. AU - Daily, Johanna P.. AU - Le Roch, Karine G.. AU - Sarr, Ousmane. AU - Fang, Xuemin. AU - Zhou, Yingyao. AU - Ndir, Omar. AU - Mboup, Soulyemane. AU - Sultan, Ali. AU - Winzeler, Elizabeth A.. AU - Wirth, Dyann F.. N1 - Copyright: Copyright 2013 Elsevier B.V., All rights reserved.. PY - 2004/8/5. Y1 - 2004/8/5. N2 - Background: Both host and pathogen factors contribute to disease outcome in Plasmodium falciparum infection. The feasibility of studying the P. falciparum in vivo transcriptome to understand parasite transcriptional response while it resides in the human host is presented. Methods: A custom made oligonucleotide array with probes based on the P. falciparum 3D7 laboratory strain chromosome 2 sequence was used to detect in vivo P. falciparum transcripts. This study analyzed transcripts from total RNA derived from small blood samples of P. falciparum infected patients and compared the in vivo expression ...
Molecular dissection of the human antibody response to the structural repeat epitope of Plasmodium falciparum sporozoite from a...
Background: The circumsporozoite surface protein is the primary target of human antibodies against Plasmodium falciparum sporozoites, these antibodies are predominantly directed to the major repetitive epitope (Asn-Pro-Asn-Ala)n, (NPNA)n. In individuals immunized by the bites of. irradiated Anopheles mosquitoes carrying P. falciparum sporozoites in their salivary glands, the antirepeat. response dominates and is thought by many to play a role in protective immunity.. Methods: The antibody repertoire from a protected individual immunized by the bites of irradiated P. falciparum infected Anopheles stephensi was recapitulated in a phage display library. Following affinity based selection against (NPNA)3 antibody fragments that recognized the PfCSP repeat epitope were rescued.. Results: Analysis of selected antibody fragments implied the response was restricted to a single antibody fragment consisting of VH3 and VkI families for heavy and light chain respectively with moderate affinity for the ...
Differences between Plasmodium vivax and Plasmodium falciparum | Difference Between | Online Microbiology Notes
Differences between Plasmodium vivax and Plasmodium falciparum. Plasmodium vivax and Plasmodium falciparum Differences. Plasmodium vivax vs falciparum.
AID 157870 - Growth inhibition of chloroquine-resistant Plasmodium falciparum K1 by [3H]hypoxanthine uptake - PubChem
BioAssay record AID 157870 submitted by ChEMBL: Growth inhibition of chloroquine-resistant Plasmodium falciparum K1 by [3H]hypoxanthine uptake.
The central role of cAMP in regulating Plasmodium falciparum merozoite invasion of human erythrocytes • Research - Institut...
Link to Pubmed [PMID] - 25522250. PLoS Pathog. 2014 Dec;10(12):e1004520. All pathogenesis and death associated with Plasmodium falciparum malaria is due to parasite-infected erythrocytes. Invasion of erythrocytes by P. falciparum merozoites requires specific interactions between host receptors and parasite ligands that are localized in apical organelles called micronemes. Here, we identify cAMP as a key regulator that triggers the timely secretion of microneme proteins enabling receptor-engagement and invasion. We demonstrate that exposure of merozoites to a low K+ environment, typical of blood plasma, activates a bicarbonate-sensitive cytoplasmic adenylyl cyclase to raise cytosolic cAMP levels and activate protein kinase A, which regulates microneme secretion. We also show that cAMP regulates merozoite cytosolic Ca2+ levels via induction of an Epac pathway and demonstrate that increases in both cAMP and Ca2+ are essential to trigger microneme secretion. Our identification of the different ...
소장자료상세 - 연세대학교 의학도서관
Isolation of Non-Parenchymal Cells from the Mouse Liver -- Measurement of the T Cell Response to Pre-Erythrocytic Vaccination in Mice -- Characterization of Liver CD8 T cell Subsets that are Associated with Protection against Pre-Erythrocytic Plasmodium Parasites -- Flow Cytometry-Based Assessment of Antibody Function against Malaria Pre-Erythrocytic Infection -- Assessment of Parasite Liver Stage Burden in Human-Liver Chimeric Mice -- Measurement of Antibody-Mediated Reduction of Plasmodium Yoelii Liver Burden by Bioluminescent Imaging -- Detection of Plasmodium Berghei and Plasmodium Yoelii Liver-Stage Parasite Burden by Quantitative Real Time PCR -- Membrane Feeding Assay to Determine the Infectiousness of Plasmodium Vivax Gametocytes -- The Standard Membrane Feeding Assay: Advances Using Bioluminescence -- Agglutination Assays of the Plasmodium Falciparum Infected Erythrocyte -- Antibody-Dependent Cell-Mediated Inhibition (ADCI) of Plasmodium Falciparum: One and Two-Step ADCI Assays -- A ...
Fetal hemoglobin modifies the disease manifestation of severe Plasmodium falciparum malaria in adult patients with sickle cell...
Fetal hemoglobin modifies the disease manifestation of severe Plasmodium falciparum malaria in adult patients with sickle cell anemia.
Artemisinin resistance in Plasmodium falciparum malaria. - Nuffield Department of Medicine
BACKGROUND: Artemisinin-based combination therapies are the recommended first-line treatments of falciparum malaria in all countries with endemic disease. There are recent concerns that the efficacy of such therapies has declined on the Thai-Cambodian border, historically a site of emerging antimalarial-drug resistance. METHODS: In two open-label, randomized trials, we compared the efficacies of two treatments for uncomplicated falciparum malaria in Pailin, western Cambodia, and Wang Pha, northwestern Thailand: oral artesunate given at a dose of 2 mg per kilogram of body weight per day, for 7 days, and artesunate given at a dose of 4 mg per kilogram per day, for 3 days, followed by mefloquine at two doses totaling 25 mg per kilogram. We assessed in vitro and in vivo Plasmodium falciparum susceptibility, artesunate pharmacokinetics, and molecular markers of resistance. RESULTS: We studied 40 patients in each of the two locations. The overall median parasite clearance times were 84 hours (interquartile
A human phase 1 vaccine clinical trial of the Plasmodium falciparum malaria vaccine candidate apical membrane antigen 1 in...
A dose escalating, placebo-controlled phase 1 trial was conducted to test the safety and immunogenicity of a vaccine containing recombinant Plasmodium falciparum apical membrane antigen 1 (AMA1) formulated in Montanide ISA720. Three groups of volunteers were vaccinated intramuscularly with 5 microg, 20 microg or 80 microg of AMA1, respectively, in 0.5 mL of formulation at 0, 3 and 6 months. Anti-AMA1 antibody levels and T cell stimulation indices were measured before and after each vaccination. No vaccine-related serious adverse events were recorded. Most subjects generated a mild to moderate, transient local reaction after the first vaccination. Three subjects developed a local reaction approximately 10 days following vaccination. Six of the 29 subjects seroconverted. Only one of these developed a high antibody titre. However, the interpretation of this trial was compromised by a loss of potency of the formulated vaccine during the course of the study ...
Naturally acquired antibodies to polymorphic and conserved epitopes of Plasmodium falciparum merozoite surface protein 3. -...
Many studies on the role of merozoite surface protein 3 (MSP3) in immunity against malaria have focused on a conserved section of MSP3. New evidence suggests that polymorphic sequences within MSP3 are under immune selection. We report a detailed analysis of naturally-acquired antibodies to allele-specific and conserved parts of MSP3 in a Kenyan cohort. Indirect and competition ELISA to heterologous recombinant MSP3 proteins were used for antibody assays, and parasites were genotyped for msp3 alleles. Antibody reactivity to allele-specific and conserved epitopes of MSP3 was heterogeneous between individuals. Overall, the prevalence of allele-specific antibody reactivity was significantly higher (3D7-specific 54%, K1-specific 41%) than that to a recombinant protein representing a conserved portion of C-terminal MSP3 (24%, P | 0.01). The most abundant IgG subclass was IgG3, followed by IgG1. Allele-specific reactivity to the K1-type of MSP3 was associated with a lower risk of clinical malaria episodes
Table 1 - Minority-Variant pfcrt K76T Mutations and Chloroquine Resistance, Malawi - Volume 13, Number 6-June 2007 - Emerging...
Genotyping of the chloroquine-resistance biomarker pfcrt (Plasmodium falciparum chloroquine resistance transporter gene) suggests that, in the absence of chloroquine pressure, Plasmodium falciparum parasites in Malawi have reverted to chloroquine sensitivity. However, malaria infections in Africa are commonly polyclonal, and standard PCRs cannot detect minority genotypes if present in <20% of the parasites in an individual host. We have developed a multiple site-specific heteroduplex tracking assay (MSS-HTA) that can detect pfcrt 76T mutant parasites consisting of as little as 1% of the parasite population. In clinical samples, no pfcrt 76T was detected in 87 pregnant Malawian women by standard PCR. However, 22 (25%) contained minority-variant resistant genotypes detected by the MSS-HTA. These results were confirmed by subcloning and sequencing. This finding suggests that the chloroquine-resistant genotype remains common in Malawians and that PCR-undetectable drug-resistant genotypes may be
Mutational analysis of Plasmodium falciparum dihydrofolate reductase: the role of aspartate 54 and phenylalanine 223 on...
The catalytic activity and ability to confer resistance to antifolates of Plasmodium falciparum dihydrofolate reductase (pfDHFR) through single and double mutations at Asp-54 and Phe-223 were investigated. A single Asp54Glu (D54E) mutation in the pfDHFR domain greatly decreased the catalytic activity of the enzyme and affected both the K, values for the substrate dihydrofolate and the K-i values for pyrimethamine, cycloguanil and WR99210. The Phe223Ser (F223S) single mutant had unperturbed kinetics but had very poor affinity with the first two antifolates. The ability to confer high resistance to the antifolates of F223S enzyme was, however, abolished in the D54E + F223S double mutant enzyme. When D54E mutation was present together with the A16V + S108T double mutation, the effects on the Km values for the substrate dihydrofolate and the binding affinity of antifolates were much more pronounced. The severely impaired kinetics and poor activity observed in A16V+S108T+D54E enzyme could, however, ...
Enhancing blockade of Plasmodium falciparum erythrocyte invasion: assessing combinations of antibodies against PfRH5 and other...
No vaccine has yet proven effective against the blood-stages of Plasmodium falciparum, which cause the symptoms and severe manifestations of malaria. We recently found that PfRH5, a P. falciparum-specific protein expressed in merozoites, is efficiently targeted by broadly-neutralizing, vaccine-induced antibodies. Here we show that antibodies against PfRH5 efficiently inhibit the in vitro growth of short-term-adapted parasite isolates from Cambodia, and that the EC(50) values of antigen-specific antibodies against PfRH5 are lower than those against PfAMA1. Since antibody responses elicited by multiple antigens are speculated to improve the efficacy of blood-stage vaccines, we conducted detailed assessments of parasite growth inhibition by antibodies against PfRH5 in combination with antibodies against seven other merozoite antigens. We found that antibodies against PfRH5 act synergistically with antibodies against certain other merozoite antigens, most notably with antibodies against other erythrocyte
Common variation in the ABO glycosyltransferase is associated with susceptibility to severe Plasmodium falciparum malaria -...
There is growing epidemiological and molecular evidence that ABO blood group affects host susceptibility to severe Plasmodium falciparum infection. The high frequency of common ABO alleles means that even modest differences in susceptibility could have a significant impact on the health of people living in malaria endemic regions. We performed an association study, the first to utilize key molecular genetic variation underlying the ABO system, genotyping |9000 individuals across three African populations. Using population- and family-based tests, we demonstrated that alleles producing functional ABO enzymes are associated with greater risk of severe malaria phenotypes (particularly malarial anemia) in comparison with the frameshift deletion underlying blood group O: case-control allelic odds ratio (OR), 1.2; 95% confidence interval (CI), 1.09-1.32; P = 0.0003; family-studies allelic OR, 1.19; 95% CI, 1.08-1.32; P = 0.001; pooled across all studies allelic OR, 1.18; 95% CI, 1.11-1.26; P = 2 x 10(-7). We
Human population, urban settlement patterns and their impact on Plasmodium falciparum malaria endemicity. - Oxford Neuroscience
BACKGROUND: The efficient allocation of financial resources for malaria control and the optimal distribution of appropriate interventions require accurate information on the geographic distribution of malaria risk and of the human populations it affects. Low population densities in rural areas and high population densities in urban areas can influence malaria transmission substantially. Here, the Malaria Atlas Project (MAP) global database of Plasmodium falciparum parasite rate (PfPR) surveys, medical intelligence and contemporary population surfaces are utilized to explore these relationships and other issues involved in combining malaria risk maps with those of human population distribution in order to define populations at risk more accurately. METHODS: First, an existing population surface was examined to determine if it was sufficiently detailed to be used reliably as a mask to identify areas of very low and very high population density as malaria free regions. Second, the potential of
Phylogenetic Analysis and Protein Modeling of Plasmodium falciparum Aspartate Transcarbamoylase (ATCase)<...
TY - JOUR. T1 - Phylogenetic Analysis and Protein Modeling of Plasmodium falciparum Aspartate Transcarbamoylase (ATCase). AU - Depamede, Sulaiman. AU - Menz, Ian. PY - 2011. Y1 - 2011. N2 - Unlike most mammalian cells, Plasmodium sp., are unable to utilize preformed pyrimidine bases and nucleosides hence they are reliant solely on de novo pathway. Aspartate transcarbamoylase (ATCase, EC 188.8.131.52) catalyzes the first committed step in de novo pyrimidine biosynthesis pathway, is a potential target for novel anti-parasitic including antimalarial drugs. P. falciparum ATCase has not been studied extensively. To reveal whether it has a regulatory subunit or no and how its evolution, phylogenetic analysis and protein modeling of ATCase P. falciparum were studied. The structural model can be used to identify the possible differences between active sites of mammalian and Plasmodium enzyme. This is important in a relation with antimalarial drug development. Analogous sequences from P. falciparum were ...
Impact of Hemoglobin S trait on cell surface antibody recognition of plasmodium falciparum-infected erythrocytes in pregnancy...
Background Sickle cell trait (HbAS) confers partial protection against malaria by reducing the adhesion of Plasmodium falciparum-infected erythrocytes to host receptors, but little is known about its potential protection against placental malaria. Methods Using flow cytometry, we assessed the recognition of HbAA and HbAS VAR2CSA-expressing infected erythrocytes, by plasma from 159 Beninese pregnant women with either HbAA (normal) or HbAS. Using multivariate linear models adjusted for gravidity, parasite infection at delivery, glucose-6-phosphate dehydrogenase deficiency, and α-thalassemia carriage, we observed significantly reduced cell surface antibody binding of HbAS-infected erythrocytes by plasma from HbAS compared with HbAA women (P , 10-3). Results The difference in cell surface antibody binding was only observed when infected erythrocytes and plasma were associated according to the same hemoglobin genotype. Similar levels of VAR2CSA-specific antibody were measured by enzyme-linked ...
The biology of some intraerythrocytic parasites of fishes, amphibia and reptiles - CORE
Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan ...
Investigating the efficacy of triple artemisinin-based combination therapies (TACTs) for treating Plasmodium falciparum malaria...
Spiral: Pfhrp2-deleted Plasmodium falciparum parasites in the Democratic Republic of the Congo: a national cross-sectional...
Background. Rapid diagnostic tests (RDTs) account for more than two-thirds of malaria diagnoses in Africa. Deletions of the Plasmodium falciparum hrp2 (pfhrp2) gene cause false-negative RDT results and have never been investigated on a national level. Spread of pfhrp2-deleted P. falciparum mutants, resistant to detection by HRP2-based RDTs, would represent a serious threat to malaria elimination efforts. Methods. Using a nationally representative cross-sectional study of 7,137 children under five years of age from the Democratic Republic of Congo (DRC), we tested 783 subjects with RDT-/PCR+ results using PCR assays to detect and confirm deletions of the pfhrp2 gene. Spatial and population genetic analyses were employed to examine the distribution and evolution of these parasites. Results. We identified 149 pfhrp2-deleted parasites, representing 6.4% of all P. falciparum infections country-wide (95% confidence interval 5.1-8.0%). Bayesian spatial analyses identified statistically significant ...
Uridine monophosphate synthase
In Plasmodium falciparum, the OPRTase-OMPDCase complex increases the kinetic and thermal stability when compared to ... "Leaving group activation and pyrophosphate ionic state at the catalytic site of Plasmodium falciparum orotate ... monophosphate decarboxylase enzyme complex in human malaria parasite Plasmodium falciparum". Biochemical and Biophysical ... P. falciparum ODCase has been successfully inhibited by modifications on cytidine-5'-monophosphate N3 and N4. Click on genes, ...
It has also been used to study the structure of Plasmodium falciparum, a particularly pathogenic form of malaria. In 1986, P. A ... "Interpretation of the ultraviolet-visible spectra of malaria parasite Plasmodium falciparum". Applied Optics. 49 (2): 180-8. ...
Diseases of poverty
March 1999). "The effect of Plasmodium falciparum malaria on HIV-1 RNA blood plasma concentration". AIDS. 13 (4): 487-94. doi: ...
... and Plasmodium falciparum (malaria), however it is also the most toxic to mammalian cells which limits its viability as a ...
The smallest mitochondrial genome sequenced to date is the 5,967 bp mtDNA of the parasite Plasmodium falciparum. Endosymbiotic ... Tyagi S, Pande V, Das A (February 2014). "Whole mitochondrial genome sequence of an Indian Plasmodium falciparum field isolate ...
... an investigation of Plasmodium falciparum malaria in African populations. jisc.ac.uk (DPhil thesis). University of Oxford. OCLC ...
"Compositional constraints in the extremely GC-poor genome of Plasmodium falciparum". Memórias do Instituto Oswaldo Cruz. 92 (6 ...
Plasmodium falciparum and other Plasmodium spp. (parasites causing malaria). Similar to plants, several Apicomplexan species, ... Tan JL, Ward L, Truscott KN, Dougan DA (October 2016). "The N-end rule adaptor protein ClpS from Plasmodium falciparum exhibits ... In vitro data demonstrate that Plasmodium falciparum ClpS is able to recognize a variety of N-terminal primary destabilizing ... November 2005). "A protein interaction network of the malaria parasite Plasmodium falciparum". Nature. 438 (7064): 103-7. ...
The four species infective to humans are P. falciparum, P. malariae, P. vivax and P. ovale. Leishmania, unicellular organisms ... Manson further predicted that the malaria parasite, Plasmodium, had a mosquito vector, and persuaded Ronald Ross to investigate ... These include organisms such as: Plasmodium spp., the protozoan parasite which causes malaria. ...
... antimalarial activity against Plasmodium falciparum, and cytotoxicity to cultured human cancer cell lines. Verspagen, N.; ...
... or both of the malarial parasite Plasmodium falciparum. Carpenter, Stanley J.; LaCasse, Walter J. (1974). Mosquitoes of North ...
Protein function prediction
"Molecular insights into the interaction between Plasmodium falciparum apical membrane antigen 1 and an invasion-inhibitory ...
"DNA cloning of Plasmodium falciparum circumsporozoite gene: amino acid sequence of repetitive epitope". Science. 225 (4662): ... "Binding and Invasion of Liver Cells by Plasmodium falciparum Sporozoites". The Journal of Biological Chemistry. 277 (9): 7092- ... "Transgenic Parasites Stably Expressing Full-Length Plasmodium falciparum Circumsporozoite Protein as a Model for Vaccine Down- ... Circumsporozoite protein (CSP) is a secreted protein of the sporozoite stage of the malaria parasite (Plasmodium sp.) and is ...
Instead, they develop into peculiar lobulated schizonts of less than 100 μm in size, similar to Plasmodium falciparum stages in ... similarly to the stages of Plasmodium falciparum in the liver. The vector of Nycteria has been hard to acquire and identify. ...
Plasmodium falciparum 3D7 (malaria parasite) Rattus norvegicus (Norway rat) Ricinus communis (castor bean) Saccharomyces ...
... an organophosphorus compound Plasmodium falciparum, a species of Plasmodium that causes malaria in humans Polar front, in ...
Plasmodium falciparum, DeRisi's group has developed profoundly promising candidate drugs to cure malaria. In 2004 DeRisi was ... profiling gene expression throughout the lifecycle of the malaria-causing protozoan Plasmodium falciparum, his discovery of the ... "The Transcriptome of the Intraerythrocytic Developmental Cycle of Plasmodium falciparum", PLOS Biology, 1 (1): e5, doi:10.1371/ ... "Comparative whole genome transcriptome analysis of three Plasmodium falciparum strains", Nucleic Acids Research, 34 (4): 1166- ...
"An improved method for undertaking limiting dilution assays for in vitro cloning of Plasmodium falciparum parasites". Malaria ...
"Histone 4 lysine 8 acetylation regulates proliferation and host-pathogen interaction in Plasmodium falciparum". Epigenetics & ...
The work challenges the former belief that G6PD mutations were selected by P. falciparum and highlights the significant effect ... White, NJ (Jan 15, 2008). "Plasmodium knowlesi: the fifth human malaria parasite". Clinical Infectious Diseases. 46 (2): 172-3 ... and its effect on Plasmodium vivax (one of the six species of malaria parasites that commonly infect humans) density. ... "Positively Selected G6PD-Mahidol Mutation Reduces Plasmodium vivax Density in Southeast Asians" (PDF). Science. 326 (5959): ...
"Binding site differences revealed by crystal structures of Plasmodium falciparum and bovine acyl-CoA binding protein". J. Mol. ...
For example in Plasmodium falciparum, many intergenic regions have an AT content of 90%. As intergenic regions are a subset of ... October 2002). "Genome sequence of the human malaria parasite Plasmodium falciparum". Nature. 419 (6906): 498-511. doi:10.1093/ ...
Extracts of T. catappa have shown activity against Plasmodium falciparum chloroquine (CQ)-resistant (FcB1) and CQ-sensitive ( ...
It is primarily active against Plasmodium falciparum, but also against Plasmodium vivax. Due to the emergence of pyrimethamine- ... 2004). "Evolution of resistance to sulfadoxine-pyrimethamine in Plasmodium falciparum". Antimicrob Agents Chemother. 48 (6): ... antimalarial activities and binding affinities to wild type and mutant dihydrofolate reductases from Plasmodium falciparum". J ... resistant strains of P. falciparum, pyrimethamine alone is seldom used now. In combination with a long-acting sulfonamide such ...
GDP-fucose protein O-fucosyltransferase 2
The malaria parasite Plasmodium falciparum requires POFUT2 for efficient transmission to mosquitoes and infection of human ... September 2017). "Protein O-fucosylation in Plasmodium falciparum ensures efficient infection of mosquito and vertebrate hosts ...
Weng H, Guo X, Papoin J, Wang J, Coppel R, Mohandas N, An X (January 2014). "Interaction of Plasmodium falciparum knob- ... KAHRP is a major component of knobs, feature found on Plasmodium falciparum infected erythrocytes. It has been suggested that ... Mayer C, Slater L, Erat MC, Konrat R, Vakonakis I (March 2012). "Structural analysis of the Plasmodium falciparum erythrocyte ... KAHRP (knob-associated histidine-rich protein) is a protein expressed by Plasmodium falciparum infecting erythrocytes. ...
"Identification of Plasmodium falciparum antigens by antigenic analysis of genomic and proteomic data". Proceedings of the ... infection with the malaria pathogen Plasmodium spp.) it is dispersed over a relatively large number of parasite antigens. ...
... is caused by heavy parasitization of red blood cells with Plasmodium falciparum. However, there have been ... other cases attributed to Plasmodium vivax, Plasmodium malariae, Plasmodium knowlesi. Blackwater fever is a serious ... Madhuri, M. S.; Elavarasan, K.; Benjamin, V. P.; Sridhar, M. S.; Natarajan, S.; Chiranjeevi, V. (2018-10-01). "Falciparum ... "Blackwater fever caused by Plasmodium vivax infection in the acquired immune deficiency syndrome". Br Med J (Clin Res Ed). 296 ...
Hemoglobin subunit beta
Malaria due to Plasmodium falciparum is a major selective factor in human evolution. It has influenced mutations in HBB in ... Verra F, Mangano VD, Modiano D (2009). "Genetics of susceptibility to Plasmodium falciparum: from classical malaria resistance ... HbC provides near full protection against Plasmodium falciparum in homozygous (CC) individuals and intermediate protection in ... "Haemoglobin C and S in natural selection against Plasmodium falciparum malaria: a plethora or a single shared adaptive ...
Intermittent preventive therapy
High resistance of Plasmodium falciparum to sulphadoxine/pyrimethamine in northern Tanzania and the emergence of dhps ... 372(9649): p. 1545-54 Gesase, S., et al., High resistance of Plasmodium falciparum to sulphadoxine/pyrimethamine in northern ... Competitive facilitation of drug-resistant Plasmodium falciparum malaria parasites in pregnant women who receive preventive ... for Plasmodium falciparum malaria control in Africa". www.who.int. Archived from the original on 27 May 2010. Retrieved 15 ...
Update: Chloroquine-Resistant Plasmodium falciparum -- Africa
Chloroquine-Resistant Plasmodium falciparum -- Africa The first confirmed cases of chloroquine-resistant Plasmodium falciparum ... Possible sulfadoxine-pyrimethamine resistance in Plasmodium falciparum malaria from Kenya (letter). Trans R Soc Trop Med Hyg ... Response of falciparum malaria to a standard regimen of chloroquine in Khartoum province, Sudan. World Health Organization, WHO ... Plasmodium malaria resistant to chloroquine in a Zambian living in Zambia. Br Med J 1983;286:1315-6. ...
Просмотр по теме "PLASMODIUM FALCIPARUM МАЛЯРИЯ"
Background: Plasmodium falciparum and P. vivax are prevalent in Pakistan. Data on the epidemiology of Plasmodium infec-tions in ... Documento de política acerca de la primaquina en dosis única como gametocitocida en el paludismo por Plasmodium falciparum ... Administración masiva de medicamentos contra el paludismo por plasmodium falciparum: manual práctico ... Drug-resistant falciparum malaria cases imported from Dar Es Salam, United Republic of Tanzania / by E. Stahel, A. Degrémont, ...
Plasmodium falciparum - Wellcome Sanger Institute
Plasmodium falciparum. Plasmodium falciparum is the deadliest of five human malaria species and responsible for the majority of ... Sequence of Plasmodium falciparum chromosomes 1, 3-9 and 13.. Hall N, Pain A, Berriman M, Churcher C, Harris B, Harris D, ... Genome sequence of the human malaria parasite Plasmodium falciparum.. Gardner MJ, Hall N, Fung E, White O, Berriman M, Hyman RW ... Other P. falciparum sequencing projects A draft sequence of P. falciparum IT clone was produced using Sanger sequencing (funded ...
Identification of a Plasmodium falciparum histone 2A gene
Plasmodium falciparum News, Research - Page 2
Malaria, a disease caused mainly by the parasites Plasmodium falciparum and Plasmodium vivax, (P. vivax) is associated with ... Severe forms of malaria such as Plasmodium falciparum may be deadly even after treatment with current parasite-killing drugs. ... New data provide the first clinical evidence that drug-resistant mutations in the malaria parasite Plasmodium falciparum may be ... Sanaria PfSPZ-CVac" is a live vaccine consisting of infectious Plasmodium falciparum (Pf) malaria parasites that are injected ...
A molecular marker of artemisinin-resistant Plasmodium falciparum malaria | Nature
The spread of resistance to artemisinin in isolates of the malaria pathogen Plasmodium falciparum in southeast Asia threatens ... A molecular marker is required to monitor artemisinin-resistant Plasmodium falciparum parasites in southeast Asia; here ... Frédéric Ariey and colleagues have now identified a major determinant of P. falciparum artemisinin resistance that could ... Plasmodium falciparum resistance to artemisinin derivatives in southeast Asia threatens malaria control and elimination ...
Browsing by Subject "Plasmodium falciparum"
Antigenic cross-reactions between Babesia Argentina and Plasmodium vivax and Plasmodium falciparum / by Colin G. Ludford ... [ ... Chloroquine resistance in Plasmodium falciparum malaria on the Pacific Coast of Colombia / by Ralph D. Comer ... [et al.] ... Chloroquine-resistant Plasmodium falciparum from Viet Nam / by Robin D. Powell, George J. Brewer, Alf S. Alving ... Chloroquine resistance of Plasmodium falciparum in Brazil detected by a simple in vitro method / by Karl H. Rieckmann, ...
Notices to Readers Treatment of Severe Plasmodium falciparum Malaria
... with Quinidine Gluconate: Discontinuation of Parenteral ... CDC has recently reviewed data on the reported incidence in the United States of Plasmodium falciparum malaria and has ... Notices to Readers Treatment of Severe Plasmodium falciparum Malaria with Quinidine Gluconate: Discontinuation of Parenteral ... An expanded report on the use of quinidine gluconate for the treatment of P. falciparum malaria will be published in an MMWR ...
4RGJ: Apo crystal structure of CDPK4 from Plasmodium falciparum, PF3D7 0717500
Inhibition of Plasmodium falciparum phenylalanine tRNA synthetase provides opportunity for antimalarial drug development:...
Genome sequence of the human malaria parasite Plasmodium falciparum.. Nature. 2002; 419: 498-511. View in Article *Scopus (3404 ... Inhibition of Plasmodium falciparum phenylalanine tRNA synthetase provides opportunity for antimalarial drug development. *. ... Previous ArticleBasis for drug selectivity of plasmepsin IX and X inhibition in Plasmodium falciparum and vivax ... Extra terminal residues have a profound effect on the folding and solubility of a Plasmodium falciparum sexual stage-specific ...
Unrevealing dry season Plasmodium falciparum replication biology | NotToKill-NotToDie Project | Results | H2020 | CORDIS |...
SCOP 1.73: Species: Malarial parasite (Plasmodium falciparum) [TaxId: 5833]
Plasmodium falciparum) [TaxId:5833] from a.45.1.1 Pf GST: *Species Malarial parasite (Plasmodium falciparum) [TaxId:5833] from ... Plasmodium falciparum) [TaxId:5833] from a.45.1.1 Pf GST appears in SCOP 1.71. *Species Malarial parasite (Plasmodium ... PDB entries in Species: Malarial parasite (Plasmodium falciparum) [TaxId: 5833]:. *Domain(s) for 1okt: *. Domain d1okta1: 1okt ... More info for Species Malarial parasite (Plasmodium falciparum) [TaxId:5833] from a.45.1.1 Pf GST. Timeline for Species ...
Difference between revisions of "Chloroquine Resistance in Plasmodium falciparum" - microbewiki
Plasmodium falciparum life cycle. Figure 2. Plasmodium falciparum.[http://www.parasitesinhumans.org/plasmodium-falciparum- ... Legend/credit: Plasmodium falciparum life cycle . Closed double brackets: ]] Other examples: Bold Italic Subscript: H2O ... Plasmodium falciparum. ,/i,. 2010. . PLoS ONE 5(11). : e14064. doi:10.1371/journal.pone.0014064. .] ... 1] Chinappi M, Via A., Marctili P., and Tramontano A. "On the Mechanism of Chloroquine Resistance in Plasmodium falciparum." ...
Chain A, Spermidine synthase (Plasmodium falciparum 3D7) | Protein Target - PubChem
Hematologic parameters in pediatric uncomplicated Plasmodium falciparum malaria in sub-Saharan Africa | DNDi
Risk Factors for Imported Fatal Plasmodium falciparum Malaria, France, 1996-2003 - Volume 13, Number 6-June 2007 - Emerging...
Williams TN, Mwangi TW, Wambua S, Alexander ND, Kortok M, Snow RW, Sickle cell trait and the risk of Plasmodium falciparum ... Modiano D, Luoni G, Sirima BS, Simpore J, Verra F, Konate A, Haemoglobin C protects again clinical Plasmodium falciparum ... Age as a risk factor for severe Plasmodium falciparum malaria in nonimmune patients. Clin Infect Dis. 2001;33:1774-7. DOIPubMed ... Mortality from Plasmodium falciparum malaria in travelers from the United States, 1959 to 1987. Ann Intern Med. 1990;113:326-7. ...
Reduced risk of placental parasitaemia associated with complement fixation on Plasmodium falciparum by antibodies among...
Reduced risk of placental parasitaemia associated with complement fixation on Plasmodium falciparum by antibodies among ... Reduced risk of placental parasitaemia associated with complement fixation on Plasmodium falciparum by antibodies among ... Reduced risk of placental parasitaemia associated with complement fixation on Plasmodium falciparum by antibodies among ... Reduced risk of placental parasitaemia associated with complement fixation on Plasmodium falciparum by antibodies among ...
In silico discovery of transcription regulatory elements in Plasmodium falciparum | BMC Genomics | Full Text
When applied to promoter regions of genes contained within 21 co-expression gene clusters generated from P. falciparum life ... falciparum. The fact that regulatory elements were predicted from a diverse range of functional gene clusters supports the ... falciparum intergenic regions (~90% AT) presents significant challenges to in silico cis-regulatory element discovery. We have ... falciparum genome sequence having revealed few cis-regulatory elements and associated transcription factors. Although it is ...
Effect of HIV Infection and Plasmodium falciparum Parasitemia on Pregnancy Outcomes in Malawi in: The American Journal of...
Plasmodium falciparum and human immunodeficiency virus (HIV) are both risk factors for low birth weight (LBW) and maternal ... Plasmodium falciparum. infection during pregnancy on the risk of low birth weight and maternal anemia. . Trans R Soc Trop Med ... Plasmodium falciparum. infection during pregnancy on the risk of low birth weight and maternal anemia. . Trans R Soc Trop Med ... Diagnosis of Plasmodium falciparum malaria at delivery: comparison of blood film preparation methods and of blood films with ...
Resistencia de plasmodium falciparum a tres fármacos antimaláricos en Turbo: Antioquia, Colombia,1998
... dc.contributor.author. ... Resistencia de plasmodium falciparum a tres fármacos antimaláricos en Turbo: Antioquia, Colombia,1998. es_ES. ... Resistence of plasmodium falciparum to three antimalarials in Turbo Antioquia, Colombia,1998. es_ES. ... Blair, Silvia,Lacharme, Leidy L,Carmona Fonseca, Jaime,Tobón, Alberto (2001) Resistencia de plasmodium falciparum a tres ...
Optimization of Physicochemical Properties for 4‐Anilinoquinoline Inhibitors of Plasmodium falciparum Proliferation | ChemAxon
Plasmodium falciparum). Herein, we report our continuing efforts to optimize this series against P. falciparum. Through the ... Optimization of Physicochemical Properties for 4‐Anilinoquinoline Inhibitors of Plasmodium falciparum Proliferation. Posted by ... falciparum with an improved ADME profile over the previously reported compound. ...
The erythrocyte membrane properties of beta thalassaemia heterozygotes and their consequences for Plasmodium falciparum...
Malaria parasites such as Plasmodium falciparum have exerted formidable selective pressures on the human genome. Of the human ... 2022). The erythrocyte membrane properties of beta thalassaemia heterozygotes and their consequences for Plasmodium falciparum ... The erythrocyte membrane properties of beta thalassaemia heterozygotes and their consequences for Plasmodium falciparum ... falciparum invasion, and calculated the energy required for merozoites to invade them. We found invasion-relevant differences ...
Analysis of erythrocyte signalling pathways during Plasmodium falciparum infection identifies targets for host-directed...
Analysis of erythrocyte signalling pathways during Plasmodium falciparum infection identifies targets for host-directed ... Analysis of erythrocyte signalling pathways during Plasmodium falciparum infection identifies targets for host-directed ... gap through a comprehensive and dynamic assessment of host erythrocyte signaling during infection with Plasmodium falciparum. ...
Identifying the Components of Acidosis in Patients with Severe Plasmodium falciparum Malaria Using Metabolomics<...
Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely ... Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely ... Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely ... Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely ...
Plasmodium falciparum founder populations in western Cambodia have reduced artemisinin sensitivity in vitro - Research -...
Plasmodium falciparum population dynamics in a cohort of pregnant women in Senegal | Malaria Journal | Full Text
The dynamics of P. falciparum genotypes during pregnancy in 32 women in relation to VAR2CSA polymorphism and immunity was ... Pregnant women acquire protective antibodies that cross-react with geographically diverse placental Plasmodium falciparum ... 25 million pregnant women are at risk of Plasmodium falciparum infection every year[1, 2]. Plasmodium falciparum isolates ... Distribution of Birth Weight according to parity and to diversity of Plasmodium falciparum placental infection. Diversity was ...
The Plasmodium falciparum rhoptry protein RhopH3 plays essential roles in host cell invasion and nutrient uptake | Crick
Impact of parasite genomic dynamics on the sensitivity of Plasmodium falciparum isolates to piperaquine and other antimalarial...
VivaxParasiteParasitesInfectionHumansProteinInfectionsAntibodiesSpeciesVitroAntigenGrowth of Plasmodium falciparumSurveillance of Plasmodium falciparumAfricaAbstractGenomesIsolatesPrevalenceErythrocytesMosquitoMosquitoesStrainAntimalarialGenomeSevereSporozoitesUncomplicated falciparum malariaSusceptibility of Plasmodium falciparumEndemicTreatment for uncomplicatedBiologyMerozoitesOrganismGenesSchizontsProtozoaDihydrofolate reductaseGeneticMalariaeArtemisinin-resistantVaccinePopulationsAnophelesMalaria plasmodiumAssayMultidrug-resistantPatientsIncidenceSymptomaticMutationsCharacterization
- Background: Plasmodium falciparum and P. vivax are prevalent in Pakistan. (who.int)
- Diagnosing Malaria Patients with Plasmodium falciparum and vivax Using Deep. (nih.gov)
- Our framework detects whether a patient is infected, and in case of a malarial infection, reports whether the patient is infected by Plasmodium falciparum or Plasmodium vivax. (nih.gov)
- Kassim YM, Yang F, Yu H, Maude RJ, Jaeger S. Diagnosing Malaria Patients with Plasmodium falciparum and vivax Using Deep Learning for Thick Smear Images. (nih.gov)
- However, co-infection with P. vivax was associated with fewer P. falciparum genotypes per infection. (pasteur.fr)
- Plasmodium vivax, and mixed species infections accounted for 56.7%, 41.1%, and 2.2% of malaria cases, respectively. (cdc.gov)
- Identification of cryptic coinfection with Plasmodium falciparum in patients presenting with vivax malaria. (tropmedres.ac)
- This study aims to examine clearance time of P. falciparum and P. vivax parasitemia as well as putative gene mutations associated with residual or recurred parasitemia in Myanmar. (biomedcentral.com)
- A total of 63 P. falciparum and 130 P. vivax samples collected from two internally-displaced populations and one surrounding village were examined for parasitemia changes. (biomedcentral.com)
- Primaquine should be given if Plasmodium vivax or Plasmodium ovale is suspected after checking for the presence of glucose-6-phosphate dehydrogenase (G6PD) deficiency. (medscape.com)
- Plasmodium vivax-specific RDTs target P. vivax-specific parasite lactate dehydrogenase (Pv-pLDH). (itg.be)
- Previous observations of false positive Pv-pLDH test lines in P. falciparum samples incited to the present study, which assessed P. vivax-specific RDTs for the occurrence of false positive Pv-pLDH lines in P. falciparum samples. (itg.be)
- Mixed P. falciparum/P. vivax infections were ruled out by real-time PCR. (itg.be)
- CONCLUSION: False positive Pv-pLDH lines in P. falciparum samples with high parasite density occurred in 6/9 P. vivax-specific RDTs. (itg.be)
- This is of concern as P. falciparum and P. vivax are co-circulating in many regions. (itg.be)
- Plasmodium vivax does occur in Pakistan, where it is found in slightly more than 50% of malaria cases. (cdc.gov)
- More specifically, the summer project involves resolving the nanoparticle nature of a Plasmodium vivax Pvs230D1-EPA conjugated vaccine, an orthologous conjugated vaccine to Pfs230D1-EPA, using biological atomic force microscopy (Bio-AFM) and related analyses. (nih.gov)
- Placental malaria caused by Plasmodium vivax or P. falciparum in Colombia: Histopathology and mediators in placental processes. (amedeo.com)
- The decrease in total counts of malaria cases during the last decade and the increased proportion of cases due to P. falciparum both reflect the reduced numbers of service members exposed to malaria (especially P. vivax ) in Afghanistan. (health.mil)
- 1 The majority of these cases and deaths were due to mosquito-transmitted Plasmodium falciparum and occurred in sub-Saharan Africa among children under 5 years of age, but P. vivax , P. ovale , and P. malariae can also cause severe disease. (health.mil)
- It is caused by parasites such as Plasmodium falciparum and Plasmodium vivax that are injected into the bloodstream by infected mosquitoes. (medindia.net)
- Even a single infection of treated P. falciparum or P. vivax malaria was associated with reduced fetal head diameter, irrespective of whether the woman had shown symptoms or not. (medindia.net)
- In French Guiana as on the Guiana Shield, the prevalence of Plasmodium falciparum is very high (between 30 and 45 %) comparing to the high prevalence of Plasmodium vivax in South America [ 1 , 11 ]. (biomedcentral.com)
- Patients with HMS have high levels of antibody for Plasmodium falciparum, Plasmodium vivax, or Plasmodium ovale . (medscape.com)
- Such cell separations can help for example, in the investigation of the malaria parasite, Plasmodium vivax, as it preferentially invades reticulocyte cells in a process that is poorly understood. (biotechsupportgroup.com)
- Severe forms of malaria such as Plasmodium falciparum may be deadly even after treatment with current parasite-killing drugs. (news-medical.net)
- Exposure to suboptimal doses of the antiparasitic drug artemisinin could increase the sexual conversion rate of the malaria parasite Plasmodium falciparum, thereby increasing the probability of transmission, according to a study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa" Foundation. (news-medical.net)
- However, the effectiveness of chloroquine has been decreasing due to the recent developments of chloroquine resistant plasmodium falciparum parasite. (kenyon.edu)
- Plasmodium falciparum which is a protozoan parasite causes malaria which has claimed a lot of lives in malaria endemic regions (8). (kenyon.edu)
- The ability of Plasmodium parasite that allows it to be transmitted extensively comes from the fact that it develops in the red blood cells and therefore suppressing their function (Figure 2. (kenyon.edu)
- Plasmodium falciparum , an intraerythrocytic parasite that causes the most severe form of human malaria, is endemic to Haiti where it caused 32 739 infections and contributed to an estimated 741 malaria deaths in 2006 [ 1 - 3 ]. (hindawi.com)
- Malaria caused by the parasite Plasmodium falciparum continues to exert a huge burden on global public health, with over 200 million clinical cases annually and approximately half a million deaths. (nature.com)
- PlasmodiumVF-Net first detects candidates for Plasmodium parasites using a Mask Regional-Convolutional Neural Network (Mask R-CNN), filters out false positives using a ResNet50 classifier, and then follows a new approach to recognize parasite species based on a score obtained from the number of detected patches and their aggregated probabilities for all of the patient images. (nih.gov)
- Heterologous (trans-species) expression of the human malaria Plasmodium falciparum AMA-1 (PF83/AMA-1) in the rodent parasite P. berghei was highly immunogenic in mice, resulting in a response against a functionally critical domain of the molecule. (semanticscholar.org)
- Plasmodium falciparum laboratory strain TM267 was incubated for 2 hours (short exposure) or 48 hours (continuous exposure) at different temperatures (32°C, 34°C, 35°C, 38°C, 39°C, and 40°C). The starting parasite developmental stage (ring, trophozoite, or schizont) varied between experiments. (ox.ac.uk)
- Plasmodium falciparum has the morbid characteristic of being the deadliest protozoan parasite of humans. (biomedcentral.com)
- However, before it can succeed sexually in the mosquito host, P. falciparum undergoes a puberty-like process in the human blood: an asexual parasite goes through a series of changes, which will lead to the generation of a sexually competent parasite. (biomedcentral.com)
- In this study, we explored the transmission dynamics of Plasmodium falciparum in mosquitoes fed with anti-AnAPN1 monoclonal antibodies (mAbs) vs. untreated controls, and investigated whether the parasite genetic content affects or is affected by antibody treatment. (pasteur.fr)
- Characterisation of complexes formed by parasite proteins exported into the host cell compartment of Plasmodium falciparum infected red blood cells. (edu.au)
- During its intraerythrocytic life cycle, the human malaria parasite Plasmodium falciparum supplements its nutritional requirements by scavenging substrates from the plasma through the new permeability pathways (NPPs) installed in the red blood cell (RBC) membrane. (edu.au)
- A ) In vitro growth inhibition (GIA) assays were performed to assess the abilities of the monoclonal antibodies raised against recombinant CyRPA to block P. falciparum parasite growth in human erythrocytes. (elifesciences.org)
- These results show that replacement of Pfs47 haplotypes is sufficient to change the compatibility of P. falciparum to evolutionarily diverse anopheline vectors, by allowing the parasite to evade the mosquito complement-like system. (nih.gov)
- Frequency of mutations in various gene codons among samples that showed fast (parasite cleared at day 2 or 3) and delayed (parasite cleared after day 3) clearance of P. falciparum . (biomedcentral.com)
- Homologous lncRNA-TARE loci are coordinately expressed after parasite DNA replication, and are poised to play an important role in P. falciparum telomere maintenance, virulence gene regulation, and potentially other processes of parasite chromosome end biology. (biomedcentral.com)
- The causative agent of the most severe form of human malaria, Plasmodium falciparum , is a unicellular eukaryotic parasite transmitted through the bites of infected mosquitoes. (biomedcentral.com)
- Genetic characterization of Plasmodium falciparum infections in north-western Thailand, a region of low transmission intensity (1 infection/person each year), has found a comparable number of parasite genotypes per infected person to regions with hyperendemic malaria. (pasteur.fr)
- Although an acetyltransferase (PfGCN5) has been shown to preferentially acetylate histone H3 at K9 and K14 in Plasmodium falciparum, the scale of histone acetylation in the parasite genome and its role in transcriptional activation are essentially unknown. (elsevier.com)
- The selective sweep hypothesis requires that populations of P. falciparum be effectively clonal, despite the obligate sexual stage of the parasite life cycle. (escholarship.org)
- We carried out a population-based study to determine the unbiased, age-specific Plasmodium falciparum prevalence, asexual and sexual parasite density, and spatial distribution to establish rates of infection at a site in western Kenya. (cdc.gov)
- The phylum Apicomplexa includes intracellular parasites causing immense global disease burden, the deadliest of them being the human malaria parasite Plasmodium falciparum , which invades and replicates within erythrocytes. (biomedcentral.com)
- Of the two actin genes in P. falciparum, actin-1 ( pfact1 ) is ubiquitously expressed in all life-cycle stages and is thought to be required for erythrocyte invasion, although its functions during parasite development are unknown, and definitive in vivo characterisation during invasion is lacking. (biomedcentral.com)
- Malaria causes almost half a million deaths and immeasurable morbidity every year, with most deaths attributable to Plasmodium falciparum , the deadliest of the five parasite species capable of infecting humans [ 2 ]. (biomedcentral.com)
- Plasmodium falciparum, the protozoan parasite responsible for severe malaria infection, undergoes a complex life cycle. (tropmedres.ac)
- We conclude that P. falciparum iRBC can bind host VEGF-R on the erythrocyte membrane and accumulate host VEGF within the parasitophorous vacuole, which may have a trophic effect on parasite growth. (tropmedres.ac)
- This source appears in the Malaria Atlas Project Plasmodium Falciparum Parasite Rate Database . (healthdata.org)
- This photomicrograph of a blood smear reveals both a macrogametocyte (right), and microgametocyte of the Plasmodium falciparum parasite. (doe.gov)
- The protozoan parasite Plasmodium falciparum is the causal agent of human malaria. (doe.gov)
- Genome sequence of the human malaria parasite Plasmodium falciparum. (doe.gov)
- We have tested the susceptibility of Plasmodium falciparum to iron deprivation by studying the effect of desferrioxamine (DF), a specific iron chelating agent, on parasite growth in an in vitro culture system. (elsevier.com)
- To investigate the possibility that the host fever response in malaria may affect parasite development, we studied the effect of temperature on Plasmodium falciparum in erythrocytic culture in vitro. (ox.ac.uk)
- Plasmodium viridax, a protozoal parasite, is a human pathogen. (microbiologynote.com)
- Plasmodium falciparum, a protozoan parasite that infects humans unicellularly, is the most deadly form of Plasmodium. (microbiologynote.com)
- P. falciparum has been described as the most deadly parasite known to man. (microbiologynote.com)
- Deconstructing the parasite multiplication rate of Plasmodium falciparum. (midasnetwork.us)
- The parasite multiplication rate (PMR) is a widely used indicator for the Plasmodium intraerythrocytic development cycle (IDC), for example, but its relationship to clinical outcomes is complex. (midasnetwork.us)
- Here, we review its calculation and use in P. falciparum malaria research, as well as the parasite and host factors that impact it. (midasnetwork.us)
- Genetic diversity in Plasmodium falciparum populations can be used to describe the resilience and spatial distribution of the parasite in the midst of intensified intervention efforts. (biomedcentral.com)
- Asymptomatic malaria parasite carriage was determined using microscopy and PCR, whilst fragment analysis of 6 microsatellite loci was used to determine the diversity and population structure of P. falciparum parasites. (biomedcentral.com)
- P. falciparum infections from the border regions in China were genetically similar to Myanmar and parasite gene flow was not constrained by geographical distance. (elsevier.com)
- Although malaria is an ancient disease caused by Plasmodium parasite, it remains important to public health to present era. (parasitol.kr)
- To date, a large amount of genetic data has been accumulated both for humans and Plasmodium falciparum , which causes the most severe forms of malaria, including the genomes of various strains and isolates of the parasite. (biomedcentral.com)
- The project aimed at exploring the biology of asymptomatic P. falciparum parasites and its interactions with the human host during the dry season that ensure that the parasite is not cleared and can be transmitted in the next transmission season. (uni-heidelberg.de)
- When applied to image the most virulent human malaria parasite, Plasmodium falciparum , the first approach, using live time-lapse wide-field microscopy, allows the capture of transient events during invasion and postinvasion intra-erythrocytic development, while the second, using immunofluorescence assay (IFA) of fixed samples, allows high-definition exploration of parasite architecture on multiple platforms. (springernature.com)
- Evaluation of a parasite-density based pooled targeted amplicon deep sequencing (TADS) method for molecular surveillance of Plasmodium falciparum drug resistance genes in Haiti. (amedeo.com)
- Genomic miscellany and allelic frequencies of Plasmodium falciparum msp-1, msp-2 and glurp in parasite isolates. (amedeo.com)
- RDT positive rate was 20.8%, 8.8% and 22.0% and Plasmodium falciparum parasite (blood film) prevalence rate was 5.3%, 2.1% and 4.9% respectively. (mcdconsortium.org)
- This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM . (bvsalud.org)
- The usage of quantitative qRT-PCR assays for detection and quantification of late gametocyte phases has revealed the excessive transmission capability of the human malaria parasite, Plasmodium falciparum. (genzymediagnostics.com)
- This form of movement is unique to parasites from the phylum Apicomplexa, such as Plasmodium and Toxoplasma. (news-medical.net)
- Although the preva- malaria and pregnant women are more like- lence and density of P. falciparum parasites ly to develop clinical attacks of malaria and are higher in pregnant women than in non- serious complications than non-pregnant pregnant women, most infections remain women of the same age. (who.int)
- Although this approach may appear attractive, the fact that in Plasmodium falciparum (P. f.) malaria, the severity of which should give it the highest diagnostic priority, the fact that most circulating intra-erythrocytic P. f. parasites contain little or no Hz raises some concern. (nih.gov)
- The P. falciparum parasites expressed haemagglutinin-tagged CyRPA protein. (elifesciences.org)
- Malaria is a life-threatening disease caused by Plasmodium falciparum parasites that are transmitted to people through the bites of infected anopheline mosquitoes. (nih.gov)
- A systematic bioactivity-guided fractionation of this plant was conducted involving the determination of the effect of its various extracts and their chemical constituents on the lactate dehydrogenase activity of in vitro chloroquine-resistant Gombak A isolate and chloroquine-sensitive D10 strain of Plasmodium falciparum parasites. (globinmed.com)
- The recent origin of the world-wide P. falciparum populations may account for its virulence, as the most malignant of human malarial parasites. (escholarship.org)
- Sequencing of 2 fragments in the P. falciparum prevalent, which suggests that parasites may be resistant chloroquine resistance transporter ( pfcrt ) gene covering to multiple commonly used antimalarial drugs. (cdc.gov)
- It is more virulent than Plasmodium falciparum (the most deadly of the five human malaria parasites), but it can be fatal. (microbiologynote.com)
- This study used microsatellite analysis to evaluate the genetic diversity and population dynamics of P. falciparum parasites circulating in three ecological zones of Ghana. (biomedcentral.com)
- Genetic diversity in P. falciparum parasites primarily results from recombination between different clones in addition to within clone polymorphisms including chromosomal deletions, gene duplication, number of repeat sequences and point mutations at various genetic loci [ 5 ]. (biomedcentral.com)
- Exploring Plasmodium falciparum Var Gene Expression to Assess Host Selection Pressure on Parasites During Infancy. (ox.ac.uk)
- We hypothesized that producing tambjamine-resistant P. falciparum parasites would result in one or more mutations in the DNA sequence of those resistant lines, revealing the molecular target(s) of the tambjamines. (dominican.edu)
- It is possible that tambjamines have multiple or nonspecific targets when inhibiting the growth of P. falciparum parasites. (dominican.edu)
- The malaria pathogens, parasites of the genus Plasmodium, need the Anopheles mosquito to get into humans. (uni-heidelberg.de)
- Also developed by Sanaria Inc. with support from NIAID, this vaccine introduces live P. falciparum parasites into the bloodstream. (nih.gov)
- The saliva test detects a novel biomarker for Plasmodium falciparum parasites. (ufl.edu)
- The vector-borne infectious disease, malaria can be caused by one of four types of Plasmodium parasites that can infect humans, with Plasmodium falciparum causing the most dangerous infection. (kenyon.edu)
- On November 3rd he visited a local hospital in Côtes des Arcadins and was diagnosed with P. falciparum infection by peripheral blood smear. (hindawi.com)
- Eisele TP , Keating J , Bennett A , Londono B , Johnson D , Lafontant C , Prevalence of Plasmodium falciparum infection in rainy season, Artibonite Valley, Haiti, 2006. (cdc.gov)
- Plasmodium falciparum infection causes febrile illness and severe disease with multiple organ failure and death when treatment is delayed. (ox.ac.uk)
- Genetic analysis revealed a significant sib-mating within P. falciparum infra-populations infecting one host, as measured by the strong correlation between Wright's FIS and multiplicity of infection. (pasteur.fr)
- The mosquito immune system can greatly limit infection and P. falciparum evolved a strategy to evade these responses mediated by Pfs47. (nih.gov)
- The entomological inoculation rate and Plasmodium falciparum infection in African children. (ox.ac.uk)
- The 2015 WHO guidelines for the treatment of malaria state that, if the species cannot be confirmed, the patient should be managed as if the infection is caused by P falciparum. (medscape.com)
- Plasmodium falciparum infection causes variable clinical symptoms ranging from asymptomatic to severe manifestations. (parasitol.kr)
- The problems of Plasmodium falciparum infection in pregnant women have been described in numerous sub-Saharan African countries, but the frequency of parasitemia at the first antenatal visit and risk factors for infection have not been fully investigated. (ajtmh.org)
- Because P. falciparum has a complex lifecycle during human infection, most advanced malaria vaccine candidates and current chemoprophylaxis drugs can confer only partial, short-term protection in malaria-endemic areas. (nih.gov)
- Increased circulation time of Plasmodium falciparum underlies persistent asymptomatic infection in the dry season. (uni-heidelberg.de)
- A Systematic Review Protocol to Establish Plasmodium Falciparum Genetic Diversity, Multiplicity of Infection, Genotyping Approaches, and Methods of Reporting It in Africa. (uncst.go.ug)
- Little efforts have been made to systematically establish P. falciparum genetic diversity and multiplicity of infection (MOI) in African settings. (uncst.go.ug)
- Malaria is a potentially life-threatening parasitic disease caused by infection with Plasmodium protozoa transmitted by an infective female Anopheles mosquito. (medscape.com)
- Plasmodium falciparum infection carries a poor prognosis with a high mortality if untreated, but it has an excellent prognosis if diagnosed early and treated appropriately. (medscape.com)
- In the United States, patients with P falciparum infection are often treated on an inpatient basis to allow observation for complications. (medscape.com)
- Progress towards the development of highly effective vaccines for malaria has been frustratingly slow, but a distinctive bright spot for malaria vaccine and immunology researchers is the availability of human experimental models of P. falciparum -infection and malaria immunity. (jcvi.org)
- Remarkably, investigators at the Radboud University Nijmegen Medical Centre (RUNMC) in The Netherlands have shown that long-term sterile immunity (at least 28 months) to experimental P. falciparum -infection can be induced by exposing malaria-naïve volunteers to the bites of 15 P. falciparum-infected mosquitoes monthly for three months while on chloroquine prophylaxis (CPS immunization). (jcvi.org)
- We are currently carrying out genome-wide transcriptomic analysis of a cohort undergoing experimental P. falciparum -infection to identify transcriptional 'signatures' of CPS efficacy. (jcvi.org)
- Owing to the differential rate of acquiring immunity to malaria after experimental and natural P. falciparum -infection, this information could provide critical insights into development strategies for novel malaria vaccines. (jcvi.org)
- 70% (n = 1,138) had PCR-positive Plasmodium falciparum infection at least once over the course of pregnancy and/or positive placental histology. (duke.edu)
- It is the most widespread species of Plasmodium that causes malaria in humans. (microbiologynote.com)
- We found MSP1 already characterized protein and Pf4.4.13 and the basic transcription factor 3B (PfBTF3B), which have not yet been characterized in P. falciparum as effectors. (usp.br)
- Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is a leading asexual blood-stage vaccine candidate for malaria. (nature.com)
- 2 The most advanced of these candidates is the P. falciparum reticulocyte-binding protein homolog 5 (PfRH5). (nature.com)
- Plasmodium falciparum 3D7 conserved Plasmodium protein, unknown function (PF3D7_0520200), partial mRNA. (genscript.com)
- Over-expression of a GFP-PfRab1A fusion protein in Plasmodium falciparum schizonts produces a punctate pattern of fluorescence typical of rhoptries, secretory organelles involved in host cell invasion. (inserm.fr)
- We identified 872 protein-coding genes and 60 putative P. falciparum lncRNAs under developmental regulation during the parasite's pathogenic human blood stage. (biomedcentral.com)
- Stability of interferon-gamma and interleukin-10 responses to Plasmodium falciparum liver stage antigen 1 and thrombospondin-related adhesive protein immunodominant epitopes in a highland population from Western Kenya. (umassmed.edu)
- Moormann AM, Sumba PO, Tisch DJ, Embury P, King CH, Kazura JW, John CC. Stability of interferon-gamma and interleukin-10 responses to Plasmodium falciparum liver stage antigen 1 and thrombospondin-related adhesive protein immunodominant epitopes in a highland population from Western Kenya. (umassmed.edu)
- We report a method for typing polymorphisms at the T-cell epitopes within the Th2R and Th3R regions of the Plasmodium falciparum circumsporozoite protein (CSP). (unl.pt)
- This method has been developed specifically for the assessment of the protective efficacy of RTS,S/SBAS2 vaccine against the 3D7 strain of P. falciparum (RTS,S/SBAS2 vaccine contains a part of the 3D7 CSP protein) in a phase IIb trial in Gambia which has been completed recently. (unl.pt)
- Greenwood, Brian M. / High-throughput sequence typing of T-cell epitope polymorphisms in Plasmodium falciparum circumsporozoite protein . (unl.pt)
- It presents the unprecedented, 3D atomic-resolution structure of a protein made by P. falciparum that's been a major source of its resistance: the chloroquine-resistance transporter protein, or PfCRT. (nih.gov)
- PfCRT is a transport protein embedded in the surface membrane of what passes for the gut of P. falciparum . (nih.gov)
- A VLP for validation of the Plasmodium falciparum circumsporozoite protein junctional epitope for vaccine development. (jenner.ac.uk)
- MAD2-6 binds to a unique epitope overlapping with region I, a functionally important region of the Plasmodium falciparum circumsporozoite protein (PfCSP). (nih.gov)
- This adhesion phenomenon has been linked to the DBL1alpha domain of P. falciparum erythrocyte membrane protein 1 (PfEMP1) in three laboratory clones: FCR3S1.2, IT4R29 and Palo Alto varO. (pasteur.fr)
- Targeting protein translation, RNA splicing, and degradation by morpholino-based conjugates in Plasmodium falciparum. (cornell.edu)
- The kinetics of the disposition of P. falciparum parasitaemia in children with drug-sensitive infections are linear. (medscape.com)
- Plasmodium falciparum infections, a major cause of childhood morbidity and mortality in developing countries, are usually treated with chloroquine, pyrimethamine-sulfadoxine, halofantrine or artemether, an artemisinin derivative. (medscape.com)
- Conventional evaluation of the responses of P. falciparum infections to antimalarial agents has used the World Health Organization (WHO) extended field test and the various time intervals required to clear specified proportions of patent peripheral parasitaemia. (medscape.com)
- Because of its rapid schizontocidal action, quinine has been the drug of choice in treating severe Plasmodium falciparum infections. (cdc.gov)
- Quinidine gluconate is an attractive alternative to quinine dihydrochloride in the treatment of P. falciparum infections when intravenous therapy is indicated because of its ready availability in most U.S. acute-care facilities. (cdc.gov)
- CDC has recently reviewed data on the reported incidence in the United States of Plasmodium falciparum malaria and has evaluated information on the effective management of severe life-threatening infections. (cdc.gov)
- As a result of this review, CDC has concluded that the drug of choice in the United States for treatment of complicated P. falciparum infections is parenteral quinidine gluconate. (cdc.gov)
- When a patient presents with P. falciparum and shock and is unresponsive to malaria treatment, secondary infections should be suspected to initiate appropriate treatment. (hindawi.com)
- Multiple Plasmodium falciparum infections in symptomatic patients. (ajtmh.org)
- Further studies in different epidemiological settings are required to understand the role of multiclonal Plasmodium falciparum infections in influencing malaria transmission. (ajtmh.org)
- Plasmodium falciparum gametocyte kinetics and infectivity may differ between chronic and incident infections. (datadryad.org)
- Co-infections (generally P falciparum and other species) should be actively ruled out in patients from areas where co-infections are known to occur. (medscape.com)
- In sub-Saharan Africa, children below 5 years bear the greatest burden of severe malaria because they lack naturally acquired immunity that develops following repeated exposure to infections by Plasmodium falciparum. (ox.ac.uk)
- Genotypic structure of P. falciparum was compared over the past three years from the same area and the demographic history was inferred to determine the source of recent infections. (elsevier.com)
- In addition, we examined if border migration is a factor of P. falciparum infections in China by determining gene flow patterns across borders. (elsevier.com)
- In 2019, the majority of the 229 million cases resulted from P. falciparum infections. (nih.gov)
- Of the 41 people who received the PfSPZ Vaccine, 27 (66%) developed P. falciparum malaria infections, compared to 37 of 40 (93%) who received the placebo. (nih.gov)
- The distribution of diverse and multiple P. falciparum infections is a major setback to the control and eventual elimination of malaria globally. (uncst.go.ug)
- To assist the Peruvian Ministry of Health in modifying the malaria treatment policy for their north Pacific coastal region, we conducted an in vivo efficacy trial of sulfadoxine-pyrimethamine (SP) and SP plus artesunate (SP-AS) for the treatment for uncomplicated Plasmodium falcipamm infections. (edu.pe)
- Subsequent immunization of mice confirmed the RH5.1/AS01 B vaccine was immunogenic and could induce functional growth inhibitory antibodies against blood-stage P. falciparum in vitro. (nature.com)
- High prevalence of natural antibodies against Plasmodium falciparum 83-kilodalton apical membrane antigen (PF83/AMA-1) as detected by capture-enzyme-linked immunosorbent assay using full-length baculovirus recombinant PF83/AMA-1. (semanticscholar.org)
- Antibodies acquired naturally through repeated exposure to Plasmodium falciparum are essential in the control of blood-stage malaria. (elifesciences.org)
- Human antibodies to P. falciparum antigens PfEMP1 and RIFIN were sufficient to promote NK-dependent growth inhibition. (elifesciences.org)
- Anti-CyRPA monoclonal antibodies inhibit P. falciparum growth and interaction of PfRh5. (elifesciences.org)
- B ) Immunoblot of inhibitory (8A7) and non-inhibitory (7A6) monoclonal antibodies against proteins from CyRPA-HA tagged transgenic P. falciparum schizonts in reduced (R) and non-reduced (NR) condition. (elifesciences.org)
- Meta-analyses of most-studied antigens were conducted to obtain summary estimates of the association between antibodies and incidence of P. falciparum malaria. (monash.edu)
- An indirect fluorescent antibody assay (IFA) using monoclonal antibodies to the 25-kDa Plasmodium falciparum ookinete surface antigen was developed to detect and quantify preoocyst stages of P. falciparum in mosquito blood meals. (elsevier.com)
- Antibodies to the surface of P. falciparum infected erythrocytes (IE) play an important role in this immunity. (ox.ac.uk)
- The production of gametocytes directly from hepatic merozoites, which has been described in other species, does not occur in P. falciparum [ 11 ]. (biomedcentral.com)
- Several antibody-based rapid diagnostic tests (RDTs) are available for diagnosing malaria, but they cover only four of the five species that cause human malaria (all except Plasmodium knowlesi). (medscape.com)
- If the patient meets the criteria for severe malaria and treatment must be initiated before the species is known, treat for P falciparum. (medscape.com)
- BACKGROUND: Most malaria rapid diagnostic tests (RDTs) detect Plasmodium falciparum and an antigen common to the four species. (itg.be)
- P. falciparum is the most important Plasmodium species that causes high malaria morbidity and mortality. (uncst.go.ug)
- In some parts of Africa, for example in Nigeria, chloroquine plus chlorphenamine (chlorpheniramine), a histamine H 1 receptor antagonist that modulates chloroquine resistance in P. falciparum in vitro and in vivo , is also used, and in Uganda, cotrimoxazole (trimethoprim-sulfamethoxazole) is often used. (medscape.com)
- Novel phenotypic assays for the detection of artemisinin-resistant Plasmodium falciparum malaria in Cambodia: in-vitro and ex-vivo drug-response studies. (nih.gov)
- To provide future opportunities for development, we aimed to identify the phenotypic difference(s) between a novel irradiated P. falciparum long-lived merozoite line and its parental line that displays up to a 20 fold increase in erythrocyte invasion rates, in vitro. (nih.gov)
- Access to liver forms of Plasmodium falciparum has been improved by the development of in vivo and in vitro propagation methods, but the yield of mature schizonts remains limited and does not allow a detailed antigenic analysis. (dtic.mil)
- Nagel, R. L. / Plasmodium falciparum : Inhibition of in vitro growth by desferrioxamine . (elsevier.com)
- Febrile temperatures can synchronize the growth of Plasmodium falciparum in vitro. (ox.ac.uk)
- Tambjamines have shown promising in vitro activity against P. falciparum , however, their molecular target is still unknown. (dominican.edu)
- Over the course of one year, the chloroquine-resistant Dd2 strain of P. falciparum was cultured in vitro and exposed to continuous pressure of fully synthetic tambjamine analog KAR457, using concentrations up to 50 nM. (dominican.edu)
- Compounds 1?10 were tested in vitro for antiplasmodial activity against a Plasmodium falciparum chloroquine-resistant strain and for cytotoxicity against a human breast cancer cell line (MCF-7). (archives-ouvertes.fr)
- Ion-exchange-immunoaffinity purification of a recombinant baculovirus Plasmodium falciparum apical membrane antigen, PF83/AMA-1. (semanticscholar.org)
- Differential localization of full-length and processed forms of PF83/AMA-1 an apical membrane antigen of Plasmodium falciparum merozoites. (semanticscholar.org)
- Induction of anti-malarial transmission blocking immunity with a recombinant ookinete surface antigen of Plasmodium berghei produced in silkworm larvae using the baculovirus expression vector system. (semanticscholar.org)
- We describe here the isolation of a DNA sequence coding for a P. falciparum liver-stage-specific antigen composed of repeats of 17 amino-acids, which is immunogenic in man. (dtic.mil)
- The RDTs included two-band (detecting Pv-pLDH), three-band (detecting P. falciparum-antigen and Pv-pLDH) and four-band RDTs (detecting P. falciparum, Pv-pLDH and pan-pLDH). (itg.be)
Growth of Plasmodium falciparum2
- Invasion and growth of Plasmodium falciparum is inhibited in fractionated thalassaemic erythrocytes. (ox.ac.uk)
- Sodium cyanate at concentrations as low as 0.5 mM inhibited the growth of Plasmodium falciparum (FCR-3 Strain) utilizing the Trager-Jensen continuous culture system. (elsevier.com)
Surveillance of Plasmodium falciparum1
- Molecular surveillance of Plasmodium falciparum resistance to artemisinin-based combination therapies in the Democratic Republic of Congo. (sciensano.be)
- In Africa each year around 24 million wom- women have acquired substantial protec- en become pregnant in malaria-endemic ar- tive immunity to malaria through repeated eas. (who.int)
- Chloroquine is used extensively in malaria endemic areas in Africa to treat uncomplicated form of Plasmodium falciparum malaria. (kenyon.edu)
- Over 75 % of the malaria cases reported in sub-Saharan Africa are caused by Plasmodium falciparum (9). (kenyon.edu)
- P. falciparum dispersed from Africa as a result of human migration which required them to adapt to several different indigenous mosquitoes. (nih.gov)
- Military personnel returning from peacekeeping missions in sub-Saharan Africa could import chloroquine-resistant Plasmodium falciparum, posing a threat to elimination and to the continued efficacy of first-line chloroquine (CQ) treatment in these countries. (cdc.gov)
- Nearly 100% of the cases in Sub-Saharan Africa were caused by P. falciparum. (microbiologynote.com)
- We report here the first case of an artemisinin resistant strain of P. falciparum from Africa. (edu.sa)
- The continuous surveillance of polymorphisms in the kelch propeller domain of Plasmodium falciparum from Africa is important for the discovery of the actual markers of artemisinin resistance in the region. (edu.gh)
- The review aims to establish P. falciparum genetic diversity MOI, genotyping approaches, and methods of reporting it in Africa. (uncst.go.ug)
- Therapeutic efficacy of artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine in the treatment of uncomplicated Plasmodium falciparum malaria in Sub-Saharan Africa: A systematic review and meta-analysis. (amedeo.com)
- The persistent threat from P. falciparum associated with duty in Africa underscores the importance of preventive measures effective against this most dangerous strain of malaria. (health.mil)
- Thirty-two cases of Plasmodium falciparum were detected in 534 irregular migrants returning to Sri Lanka via failed human smuggling routes from West Africa in 2012, contributing to the largest burden of imported cases in Sri Lanka as it entered elimination phase. (iom.int)
- The studies tested this ACT in more than 2,700 patients in Africa (Burkina Faso, Zambia, Kenya, Mozambique and Uganda) and in Asia (Thailand, India and Laos), in around 1,036 African children aged 6 months to 10 years, all affected by uncomplicated P. falciparum malaria. (mmv.org)
- abstract = "This work reports a high throughput and label-free cell deformability microfluidic sensor for quantitative parasitemia measurement and stage determination for Plasmodium falciparum-infected red blood cells (Pf-iRBCs). (elsevier.com)
- GIB (Genome Information Broker for Microbial Genomes) provides a comprehensive view of the complete microbial genome sequences.Because the genome sequence data of Guillardia theta , Leishmania major Friedlin and Plasmodium falciparum 3D7 were released, we incorporated it to GIB, and now you can search those data. (nig.ac.jp)
- Using bioinformatics methods we have analysed genomes of 15 P. falciparum isolates for sequences homological to these microRNAs. (biomedcentral.com)
- Thus, the analysis of the P. falciparum genome is required in order to identify potential interactions of its mRNAs with regulatory microRNAs, as well as to compare the genomes of its various strains to determine the level of their pathogenicity due to the differences in these interactions. (biomedcentral.com)
- Despite coding for four centrins, the Plasmodium genomes lack many conserved components of the basal body except SAS6, SAS4/CPAP and CEP135. (pberghei.eu)
- Progressive increase in point mutations associated with chloroquine resistance in Plasmodium falciparum isolates from India. (cdc.gov)
- Since the arrival of genetic typing methods in the late 1960's, researchers have puzzled at the clinical consequence of observed strain mixtures within clinical isolates of Plasmodium falciparum. (arxiv.org)
- Despite the fact that the numbers of homological intervals vary significantly between isolates, the hsa-miR-451a and hsa-miR-223-3p microRNAs are expected to make the most notable contribution to the pathogenesis of P. falciparum malaria. (biomedcentral.com)
- At day 3, the P. falciparum prevalence by qPCR was 2.5 times higher than that by microscopy. (edu.au)
- Prevalence of Plasmodium spp. (biomedcentral.com)
- This prospective study, conducted in 2015, aimed to estimate the prevalence of Plasmodium spp. (biomedcentral.com)
- Progression to severe illness from initial symptoms of fever, headache, chills, and myalgia occurs rapidly through the phenomenon of sequestration, in which P. falciparum -infected erythrocytes attach to blood vessels and impede normal blood flow, particularly in the brain [ 5 ]. (hindawi.com)
- This particular project, is to develop novel models to visualise and analyse how P. falciparum infected erythrocytes (IE) might be targeted to bind preferentially to microvessels in the brain and the impact of this on the host and clinical outcome. (malariaworld.org)
- Rosetting of erythrocytes infected with Plasmodium falciparum is frequently observed in children with severe malaria. (pasteur.fr)
- The protozoan Plasmodium falciparum has a complex life cycle in which asexual multiplication in the vertebrate host alternates with an obligate sexual reproduction in the anopheline mosquito. (biomedcentral.com)
- Among the most clever is the mosquito-borne protozoan Plasmodium falciparum , which is the cause of the most common-and most lethal-form of malaria. (nih.gov)
- It is transmitted by the bite of female Anopheles mosquitoes and causes falciparum malaria, the most severe form of the disease. (microbiologynote.com)
- We used a high-resolution DNA tiling microarray to survey transcriptional activity across 22.6% of the P. falciparum strain 3D7 genome. (biomedcentral.com)
- The recent origin of the P. falciparum populations could have resulted from either a demographic sweep (P. falciparum has only recently spread throughout the world from a small geographically confined population) or a selective sweep (one strain favored by natural selection has recently replaced all others). (escholarship.org)
- Another study of the PfSPZ Vaccine, conducted at the NIH Clinical Center, showed that the vaccine protected many recipients not only from the same strain of P. falciparum used to make the vaccine, but also from a different strain. (nih.gov)
- To examine the kinetics of the disposition of Plasmodium falciparum during treatment with antimalarial drugs in 565 children presenting with acute, symptomatic, uncomplicated malaria. (medscape.com)
- In the present study, we investigated the kinetics of the disposition of P. falciparum during treatment with antimalarial drugs in children presenting with acute, symptomatic, uncomplicated falciparum malaria, and assessed the relationship between the derived kinetic parameters and the conventional indices of therapeutic responses. (medscape.com)
- Atovaquone-proguanil is a recent antimalarial drug licensed in France for the uncomplicated P. falciparum malaria in adults. (unboundmedicine.com)
- Atovaquone-proguanil is an efficient and well-tolerated antimalarial treatment for uncomplicated P. falciparum malaria in children. (unboundmedicine.com)
- For decades, doctors have used antimalarial drugs against P. falciparum . (nih.gov)
- For this reason, we propose to characterize the P. falciparum genomic and phenotypic variations that occurred after the large-scale implementation of ACTs to identify novel genetic mechanisms of antimalarial drug resistance. (malariagen.net)
- The emergence of resistance of P. falciparum to the available antimalarial drugs is an important factor for malaria control [ 1 ]. (parasitol.kr)
- Despite recent research advances [ 1 - 6 ], the mechanisms P. falciparum utilizes to regulate mutually exclusive expression of multi-gene virulence families and stage-specific expression of approximately 80% of its genome during pathogenic blood stage development remain elusive. (biomedcentral.com)
- Using chromatin immunoprecipitation (ChIP) and DNA microarray, we mapped the global distribution of PfGCN5, histone H3K9 acetylation (H3K9ac) and trimethylation (H3K9m3) in the P. falciparum genome. (elsevier.com)
- While new drugs are being developed to thwart P. falciparum , some researchers are busy developing tools to predict what mutations are likely to occur next in the parasite's genome. (nih.gov)
- The genome sequence and gene models of Plasmodium falciparum were not determined by the Joint Genome Institute (JGI), but were downloaded from NCBI on May 28, 2018. (doe.gov)
- To our knowledge, this will be the first attempt of retrospective genome scanning to identify genome-wide signatures of directional selection in a natural P. falciparum population following ACT implementation. (malariagen.net)
- Genome-wide profiling of chromosome interactions in Plasmodium falciparum characterizes nuclear architecture and reconfigurations associated with antigenic variation. (ox.ac.uk)
- In the present work we address the problem of possibility of the existence in the P. falciparum genome of the nucleotide sequences such that mRNAs transcribed from genes containing these sequences could form duplexes with human microRNAs. (biomedcentral.com)
- Because it is an unlabeled use of the drug, the Malaria Branch, Division of Parasitic Diseases, Center for Infectious Diseases, CDC, has filed an Investigational New Drug notice (IND) with the U.S. Food and Drug Administration for the treatment of severe P. falciparum malaria with intravenous quinidine gluconate. (cdc.gov)
- Phillips RE, Warrell DA, White NJ, Looareesuwan S, Karbwang J. Intravenous quinidine for the treatment of severe falciparum malaria: clinical and pharmacokinetic studies. (cdc.gov)
- Development of a malaria vaccine, as well as, new drugs is crucial for the future control of Plasmodium falciparum, the most severe form of human malaria causing nearly a million deaths each year. (nih.gov)
- Complications of Plasmodium falciparum malaria include impaired consciousness, seizures, severe anemia, renal failure, pulmonary edema or acute respiratory distress syndrome (ARDS), refractory hypotension, and disseminated intravascular coagulation (DIC). (medscape.com)
- Oxidative stress and erythrocyte damage in Kenyan children with severe Plasmodium falciparum malaria. (ox.ac.uk)
- This study measured the concentrations of alpha-tocopherol in plasma and erythrocyte membranes, and the percentage polyunsaturated fatty acid composition (%PUFA) (an indirect marker of ROS damage) in erythrocyte membranes in children with severe P. falciparum malaria from Kilifi, Kenya, and asymptomatic children from the same district. (ox.ac.uk)
- Association of CD40L gene polymorphism with severe Plasmodium falciparum malaria in Indian population. (aiph.ac.in)
- Comparative study of clinical presentation and hematological indices in hospitalized sickle cell patients with severe Plasmodium falciparum malaria. (aiph.ac.in)
- We will administer 3,200 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ Challenge) by direct venous inoculation. (ox.ac.uk)
- Scientists at NIAID have isolated MAD2-6, an IgA antibody active against Plasmodium falciparum sporozoites, the infectious agent of malaria. (nih.gov)
Uncomplicated falciparum malaria1
- In 1973, SP replaced CQ as the first-line treatment for uncomplicated falciparum malaria due to widespread resistance [ 1 , 6 ], but after 10 years, SP was ineffective [ 1 , 7 ]. (parasitol.kr)
Susceptibility of Plasmodium falciparum2
- We looked for human sera with restricted specificity to the pre-erythrocytic stages of development of P. falciparum by screening individuals living in a malaria endemic area and undergoing continuous drug prophylaxis. (dtic.mil)
- Additionally, the choice of an effective P. falciparum genotyping approach for a specific endemic setting remains a challenge. (uncst.go.ug)
Treatment for uncomplicated1
- These results have contributed to a National Malaria Control Program decision to change to SP-AS combination therapy as the first-line treatment for uncomplicated P. falciparum malaria in northern coastal Peru in November 2001, making Peru the first country in the Americas to recommend this combination therapy. (edu.pe)
- Glycolytic enzymes play important roles in Plasmodium biology. (fapesp.br)
- Apart from the apparent recombination advantages conferred by sex, P. falciparum has evolved a remarkable biology and adaptive phenotypes to insure its transmission despite the dangers of sex. (biomedcentral.com)
- The present review focuses on specific points of commitment to sexual development - gametocytogenesis and gametocyte biology-especially those relevant to transmission and evolution of P. falciparum transmission strategies. (biomedcentral.com)
- In particular, the possibility of regulation of P. falciparum gene expression through human microRNAs is of great importance both for fundamental biology and for medicine. (biomedcentral.com)
- Gilson PR, Crabb BS (2009) Morphology and kinetics of the three distinct phases of red blood cell invasion by Plasmodium falciparum merozoites. (springernature.com)
- Even though the existence of this phenomenon in Plasmodium falciparum has long been rejected, several recent works pose hypotheses and provide direct and indirect evidence of the existence of mechanisms similar to RNA interference in this organism. (biomedcentral.com)
- Molecular surveillance of mutations in dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum in Ethiopia. (cdc.gov)
- Collectively, these results suggest that PfGCN5 is recruited to the promoter regions of genes to mediate histone acetylation and activate gene expression in P. falciparum. (elsevier.com)
- We performed a molecular epidemiologic survey drug-resistance genes (online Technical Appendix Table, of mutations associated with drug-resistance genes in www.cdc.gov/eid/content/17/3/498-Techapp.pdf), some of Plasmodium falciparum in northeastern Myanmar. (cdc.gov)
- In Plasmodium falciparum, the repositioning of chromosomes has been implicated in the regulation of the expression of genes responsible for antigenic variation, and the formation of a single, peri-nuclear nucleolus results in the clustering of rDNA. (ox.ac.uk)
- Point mutations in Plasmodium falciparum dihydrofolate reductase ( Pfdhfr ) and dihydropteroate synthase ( Pfdhps ) genes confer resistance to antifolate drug, sulfadoxine-pyrimethamine (SP) while P. falciparum chloroquine-resistant transporter ( Pfcrt ) genes caused resistance to chloroquine (CQ). (parasitol.kr)
- Mutations in the P. falciparum dihydrofolate reductase ( Pfdhfr ) and P. falciparum dihydropteroate synthase ( Pfdhps ) genes (at codons 51, 59, 108, and 164 of Pfdhfr and 437, 540, and 581 of Pfdhps ) are associated with SP treatment failures [ 10 , 11 ]. (parasitol.kr)
- Plasmodium falciparum Rab1A Localizes to Rhoptries in Schizonts. (inserm.fr)
- Plasmodium falciparum adalah protozoa parasit , salah satu spesies Plasmodium yang menyebabkan penyakit malaria pada manusia. (wikipedia.org)
- BIOTEC-NSTDA selects Key Organics BIONET Fragment Library to identify new non-pyrimidine Plasmodium falciparum dihydrofolate reductase (PfDHFR) inhibitors. (prlog.org)
- Reduced genetic diversity of P. falciparum suggested intense malaria control within the IDP settlement. (elsevier.com)
- Lindo JF , Bryce JH , Ducasse MB , Howitt C , Barrett DM , Lorenzo Morales J , Plasmodium malariae in Haitian refugees, Jamaica. (cdc.gov)
- Recent emergence of artemisinin-resistant P. falciparum has posed a serious hindrance to the elimination of malaria in the Greater Mekong Subregion. (biomedcentral.com)
- Malaria epidemiologic and entomologic studies were performed during both the high transmission and low transmission seasons to characterize the Plasmodium falciparum malaria transmission at a proposed malaria vaccine trial site in Irian Jaya, Indonesia. (ajtmh.org)
- The experimental vaccine is made of live but weakened P. falciparum . (nih.gov)
- Safety and efficacy of PfSPZ Vaccine against Plasmodium falciparum via direct venous inoculation in healthy malaria-exposed adults in Mali: a randomised, double-blind phase 1 trial. (nih.gov)
- Malaria's Eve: evidence of a recent population bottleneck throughout the world populations of Plasmodium falciparum. (escholarship.org)
- Therefore, this setting offers a unique opportunity to understand the evolution of the natural variation of Plasmodium falciparum populations and the potential for the emergence of ART resistance. (malariagen.net)
- Immunodetection of Plasmodium falciparum zygotes and ookinetes in Anopheles blood meals. (elsevier.com)
- Dive into the research topics of 'Immunodetection of Plasmodium falciparum zygotes and ookinetes in Anopheles blood meals. (elsevier.com)
- En esta secuencia se incluyen las etapas de desarrollo de apicomplejos, como ocurre con el parásito de la malaria, PLASMODIUM FALCIPARUM. (bvsalud.org)
- The lead compounds were discovered by screening the "Malaria Box" collection against P. falciparum enolase (Pfeno) enzyme in a standardized target-based assay. (fapesp.br)
- The GMS has been the breeding ground of N86Y, Y184F, and N1042D mutations making up 5 multidrug-resistant Plasmodium falciparum , and resistance haplotypes (Figure 2). (cdc.gov)
- This study revealed that CGP 56697 is effective against multidrug-resistant Plasmodium falciparum malaria in Thailand, but higher doses will probably be needed to improve the cure rate. (ajtmh.org)
- Based on a study of patients with P. falciparum treated in the United States (1), continuous infusion of quinidine gluconate is recommended. (cdc.gov)
- Of note are Plasmodium, the aetiological agent of malaria, and Toxoplasma gondii , an opportunistic pathogen that leads to fatal disease in immunocompromised patients [ 1 ]. (biomedcentral.com)
- Patients with non- P falciparum malaria who are well can usually be treated on an outpatient basis. (medscape.com)
- Methods and Findings:We performed a systematic review with meta-analysis of prospective cohort studies examining the association between anti-merozoite immunoglobin (Ig) G responses and incidence of Plasmodium falciparum malaria. (monash.edu)
- While P. falciparum does occur in Pakistan (slightly less than 50% of malaria cases), this patient reportedly did not develop symptoms until 10 months after departure from the exposure area: most cases of P. falciparum would have become symptomatic earlier. (cdc.gov)
- 2016) Mutations in the Plasmodium falciparum Cyclic Amine Resistance Locus (PfCARL) Confer Multidrug Resistance. (guidetopharmacology.org)
- But recent reports show that P. falciparum has acquired resistance to piperaquine, driven by mutations in PfCRT that are spreading rapidly across Southeast Asia . (nih.gov)
- Similar to withdrawal of SP for P. falciparum treatment, Pfdhfr and Pfdhps gene mutations also decreased in some countries [ 18 - 21 ]. (parasitol.kr)
- Characterization of Hsp90 domains of Plasmodium falciparum and mapping of the interaction. (usp.br)