Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Malaria, Falciparum: 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.Malaria: 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.Protozoan Proteins: Proteins found in any species of protozoan.Antimalarials: Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585)Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Drug Resistance: 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.Parasites: Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Artemisinins: A group of SESQUITERPENES and their analogs that contain a peroxide group (PEROXIDES) within an oxepin ring (OXEPINS).Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Plasmodium: 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.Parasitemia: The presence of parasites (especially malarial parasites) in the blood. (Dorland, 27th ed)Chloroquine: The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses.Malaria, Vivax: Malaria caused by PLASMODIUM VIVAX. This form of malaria is less severe than MALARIA, FALCIPARUM, but there is a higher probability for relapses to occur. Febrile paroxysms often occur every other day.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.DNA, Protozoan: Deoxyribonucleic acid that makes up the genetic material of protozoa.Malaria Vaccines: Vaccines made from antigens arising from any of the four strains of Plasmodium which cause malaria in humans, or from P. berghei which causes malaria in rodents.Malaria, Cerebral: 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)Pyrimethamine: One of the FOLIC ACID ANTAGONISTS that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis.SesquiterpenesAntibodies, Protozoan: Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.Quinine: 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.Plasmodium berghei: A protozoan parasite of rodents transmitted by the mosquito Anopheles dureni.Mefloquine: A phospholipid-interacting antimalarial drug (ANTIMALARIALS). It is very effective against PLASMODIUM FALCIPARUM with very few side effects.Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.Plasmodium vivax: A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.Sulfadoxine: A long acting sulfonamide that is used, usually in combination with other drugs, for respiratory, urinary tract, and malarial infections.Genes, Protozoan: The functional hereditary units of protozoa.Fluorenes: A family of diphenylenemethane derivatives.Parasite Load: Measure of the number of the PARASITES present in a host organism.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Antigens: Substances that are recognized by the immune system and induce an immune reaction.Amodiaquine: A 4-aminoquinoline compound with anti-inflammatory properties.Protozoan Infections: Infections with unicellular organisms formerly members of the subkingdom Protozoa.Parasitic Sensitivity Tests: Tests that demonstrate the relative effectiveness of chemotherapeutic agents against specific parasites.Plasmodium yoelii: A species of PLASMODIUM causing malaria in rodents.Genome, Protozoan: The complete genetic complement contained in a set of CHROMOSOMES in a protozoan.Life Cycle Stages: The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.Sporozoites: The product of meiotic division of zygotes in parasitic protozoa comprising haploid cells. These infective cells invade the host and undergo asexual reproduction producing MEROZOITES (or other forms) and ultimately gametocytes.Ethanolamines: AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.Immunity: Nonsusceptibility to the invasive or pathogenic effects of foreign microorganisms or to the toxic effect of antigenic substances.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.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.Proguanil: A biguanide compound which metabolizes in the body to form cycloguanil, an anti-malaria agent.Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Gabon: A republic in west equatorial Africa, south of CAMEROON and west of the CONGO. Its capital is Libreville.Mice, Inbred BALB CAntigens, Surface: Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Travel: Aspects of health and disease related to travel.Atovaquone: A hydroxynaphthoquinone that has antimicrobial activity and is being used in antimalarial protocols.Parasitology: The study of parasites and PARASITIC DISEASES.Pregnancy Complications, Parasitic: The co-occurrence of pregnancy and parasitic diseases. The parasitic infection may precede or follow FERTILIZATION.Apicomplexa: A phylum of unicellular parasitic EUKARYOTES characterized by the presence of complex apical organelles generally consisting of a conoid that aids in penetrating host cells, rhoptries that possibly secrete a proteolytic enzyme, and subpellicular microtubules that may be related to motility.Endemic Diseases: 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)Plasmodium chabaudi: A protozoan parasite of rodents transmitted by the mosquito Anopheles stephensi.Plasmodium malariae: A protozoan parasite that occurs primarily in subtropical and temperate areas. It is the causal agent of quartan malaria. As the parasite grows it exhibits little ameboid activity.Schizonts: Multinucleate cells or a stage in the development of sporozoan protozoa. It is exemplified by the life cycle of PLASMODIUM FALCIPARUM in the MALARIA infection cycle.RNA, Protozoan: Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.Kenya: A republic in eastern Africa, south of ETHIOPIA, west of SOMALIA with TANZANIA to its south, and coastline on the Indian Ocean. Its capital is Nairobi.Primaquine: 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)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Malaria, Avian: Any of a group of infections of fowl caused by protozoa of the genera PLASMODIUM, Leucocytozoon, and Haemoproteus. The life cycles of these parasites and the disease produced bears strong resemblance to those observed in human malaria.Merozoites: Uninuclear cells or a stage in the life cycle of sporozoan protozoa. Merozoites, released from ruptured multinucleate SCHIZONTS, enter the blood stream and infect the ERYTHROCYTES.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Senegal: A republic in western Africa, southwest of MAURITANIA and east of MALI. Its capital is Dakar.Trophozoites: Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the MEROZOITE and then splits into the SCHIZONT. Trophozoites that are left over from cell division can go on to form gametocytes.Microscopy: 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.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.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.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.AfricaProtozoan Vaccines: Suspensions of attenuated or killed protozoa administered for the prevention or treatment of infectious protozoan disease.Myanmar: 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)Mali: 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.Merozoite Surface Protein 1: A surface protein found on Plasmodium species which induces a T-cell response. The antigen is polymorphic, sharing amino acid sequence homology among PLASMODIUM FALCIPARUM; PLASMODIUM CHABAUDI; PLASMODIUM VIVAX; and PLASMODIUM YOELII.Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Toxoplasma: A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.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.Plasmodium knowlesi: A protozoan parasite from Southeast Asia that causes monkey malaria. It is naturally acquired by man in Malaysia and can also be transmitted experimentally to humans.CambodiaAntigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Mice, Inbred C57BLImmunization: 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).Blood: The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.Parasite Egg Count: Determination of parasite eggs in feces.Oocysts: Zygote-containing cysts of sporozoan protozoa. Further development in an oocyst produces small individual infective organisms called SPOROZOITES. Then, depending on the genus, the entire oocyst is called a sporocyst or the oocyst contains multiple sporocysts encapsulating the sporozoites.Plasmodium gallinaceum: A protozoan parasite that causes avian malaria (MALARIA, AVIAN), primarily in chickens, and is transmitted by the Aedes mosquito.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Tanzania: A republic in eastern Africa, south of UGANDA and north of MOZAMBIQUE. Its capital is Dar es Salaam. It was formed in 1964 by a merger of the countries of TANGANYIKA and ZANZIBAR.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.Ghana: A republic in western Africa, south of BURKINA FASO and west of TOGO. Its capital is Accra.Gambia: A republic in western Africa, constituting an enclave within SENEGAL extending on both sides of the Gambia River. Its capital is Banjul, formerly Bathurst.Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Cameroon: A republic in central Africa lying east of CHAD and the CENTRAL AFRICAN REPUBLIC and west of NIGERIA. The capital is Yaounde.Trypanosoma cruzi: The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.Eukaryota: One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.Anopheles gambiae: A species of mosquito in the genus Anopheles and the principle vector of MALARIA in Africa.Plasmodium ovale: A species of protozoan parasite causing MALARIA. It is the rarest of the four species of PLASMODIUM infecting humans, but is common in West African countries and neighboring areas.Tetrahydrofolate Dehydrogenase: 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 1.5.1.3.Mosquito Control: The reduction or regulation of the population of mosquitoes through chemical, biological, or other means.Antigens, Helminth: Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.Intestinal Diseases, Parasitic: Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.Sulfanilamides: Compounds based on 4-aminobenzenesulfonamide. The '-anil-' part of the name refers to aniline.Protozoan Infections, Animal: Infections with unicellular organisms formerly members of the subkingdom Protozoa. The infections may be experimental or veterinary.Dihydropteroate Synthase: An enzyme that catalyzes the formation of dihydropteroate from p-aminobenzoic acid and dihydropteridine-hydroxymethyl-pyrophosphate. EC 2.5.1.15.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Leishmania major: A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) of the Old World. Transmission is by Phlebotomus sandflies.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Burkina Faso: A republic in western Africa, south and east of MALI and west of NIGER. Its capital is Ouagadougou. It was formerly called Upper Volta until 1984.Sudan: A country in northeastern Africa. The capital is Khartoum.Leishmania: A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.Vaccines, DNA: Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.Anemia: A reduction in the number of circulating ERYTHROCYTES or in the quantity of HEMOGLOBIN.Insect Bites and Stings: Bites and stings inflicted by insects.Haemosporida: An order of heteroxenous protozoa in which the macrogamete and microgamont develop independently. A conoid is usually absent.Parasitic Diseases, Animal: Infections or infestations with parasitic organisms. The infestation may be experimental or veterinary.Epitopes: Sites on an antigen that interact with specific antibodies.QuinolinesParasitic Diseases: Infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure.Antiprotozoal Agents: Substances that are destructive to protozoans.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Spleen: An encapsulated lymphatic organ through which venous blood filters.Aotus trivirgatus: A species in the family AOTIDAE, inhabiting the forested regions of Central and South America (from Panama to the Amazon). Vocalizations occur primarily at night when they are active, thus they are also known as Northern night monkeys.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Indonesia: 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.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Vaccines, Attenuated: Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Immunity, Mucosal: Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.Uganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Sulfalene: Long-acting plasma-bound sulfonamide used for respiratory and urinary tract infections and also for malaria.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Inhibitory Concentration 50: The concentration of a compound needed to reduce population growth of organisms, including eukaryotic cells, by 50% in vitro. Though often expressed to denote in vitro antibacterial activity, it is also used as a benchmark for cytotoxicity to eukaryotic cells in culture.Gametogenesis: The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).Adaptive Immunity: Protection from an infectious disease agent that is mediated by B- and T- LYMPHOCYTES following exposure to specific antigen, and characterized by IMMUNOLOGIC MEMORY. It can result from either previous infection with that agent or vaccination (IMMUNITY, ACTIVE), or transfer of antibody or lymphocytes from an immune donor (IMMUNIZATION, PASSIVE).Bacterial Vaccines: Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Antibodies, Helminth: Immunoglobulins produced in a response to HELMINTH ANTIGENS.Immunity, Humoral: Antibody-mediated immune response. Humoral immunity is brought about by ANTIBODY FORMATION, resulting from TH2 CELLS activating B-LYMPHOCYTES, followed by COMPLEMENT ACTIVATION.Species Specificity: 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.Mozambique: A republic in southern Africa, south of TANZANIA, east of ZAMBIA and ZIMBABWE, bordered on the west by the Indian Ocean. Its capital is Maputo. It was formerly called Portuguese East Africa.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Ciliophora: A phylum of EUKARYOTES characterized by the presence of cilia at some time during the life cycle. It comprises three classes: KINETOFRAGMINOPHOREA; OLIGOHYMENOPHOREA; and POLYMENOPHOREA.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Hemeproteins: Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Sickle Cell Trait: The condition of being heterozygous for hemoglobin S.Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.Vaccines: Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases.Leishmania donovani: A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). The sandfly genera Phlebotomus and Lutzomyia are the vectors.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Leishmaniasis, Cutaneous: An endemic disease that is characterized by the development of single or multiple localized lesions on exposed areas of skin that typically ulcerate. The disease has been divided into Old and New World forms. Old World leishmaniasis is separated into three distinct types according to epidemiology and clinical manifestations and is caused by species of the L. tropica and L. aethiopica complexes as well as by species of the L. major genus. New World leishmaniasis, also called American leishmaniasis, occurs in South and Central America and is caused by species of the L. mexicana or L. braziliensis complexes.Erythrocyte Membrane: The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.Eimeria: A genus of protozoan parasites of the subclass COCCIDIA. Various species are parasitic in the epithelial cells of the liver and intestines of man and other animals.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Entamoeba histolytica: A species of parasitic protozoa causing ENTAMOEBIASIS and amebic dysentery (DYSENTERY, AMEBIC). Characteristics include a single nucleus containing a small central karyosome and peripheral chromatin that is finely and regularly beaded.Nigeria: A republic in western Africa, south of NIGER between BENIN and CAMEROON. Its capital is Abuja.Helminths: Commonly known as parasitic worms, this group includes the ACANTHOCEPHALA; NEMATODA; and PLATYHELMINTHS. Some authors consider certain species of LEECHES that can become temporarily parasitic as helminths.Antigens, CD: Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.Coccidiosis: Protozoan infection found in animals and man. It is caused by several different genera of COCCIDIA.LaosImmunity, Active: Resistance to a disease agent resulting from the production of specific antibodies by the host, either after exposure to the disease or after vaccination.Leishmaniasis: A disease caused by any of a number of species of protozoa in the genus LEISHMANIA. There are four major clinical types of this infection: cutaneous (Old and New World) (LEISHMANIASIS, CUTANEOUS), diffuse cutaneous (LEISHMANIASIS, DIFFUSE CUTANEOUS), mucocutaneous (LEISHMANIASIS, MUCOCUTANEOUS), and visceral (LEISHMANIASIS, VISCERAL).Fever: An abnormal elevation of body temperature, usually as a result of a pathologic process.Genetic Variation: Genotypic differences observed among individuals in a population.Malawi: A republic in southern Africa east of ZAMBIA and MOZAMBIQUE. Its capital is Lilongwe. It was formerly called Nyasaland.VietnamSequence Alignment: 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.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Naphthoquinones: Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Antigenic Variation: 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)Giardia lamblia: A species of parasitic EUKARYOTES that attaches itself to the intestinal mucosa and feeds on mucous secretions. The organism is roughly pear-shaped and motility is somewhat erratic, with a slow oscillation about the long axis.Schistosoma mansoni: A species of trematode blood flukes of the family Schistosomatidae. It is common in the Nile delta. The intermediate host is the planorbid snail. This parasite causes schistosomiasis mansoni and intestinal bilharziasis.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Diagnostic Tests, Routine: Diagnostic procedures, such as laboratory tests and x-rays, routinely performed on all individuals or specified categories of individuals in a specified situation, e.g., patients being admitted to the hospital. These include routine tests administered to neonates.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.IndiaTreatment Failure: A measure of the quality of health care by assessment of unsuccessful results of management and procedures used in combating disease, in individual cases or series.Trypanosoma brucei brucei: A hemoflagellate subspecies of parasitic protozoa that causes nagana in domestic and game animals in Africa. It apparently does not infect humans. It is transmitted by bites of tsetse flies (Glossina).Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Administration, Intranasal: Delivery of medications through the nasal mucosa.Infant, Newborn: An infant during the first month after birth.Polymorphism, Genetic: 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.
... the vaccine gave protective immunity to 7 out of 8 volunteers when challenged with P. falciparum. RTS,S/AS01 (commercial name ... Unlike other antigens of the malaria parasite which are often genetically diverse, the PfRH5 antigen appears to have little ... By their very nature, protozoa are more complex organisms than bacteria and viruses, with more complicated structures and life ... Researchers from Rhode Island Hospital identified Plasmodium falciparum PfSEA-1, a 244 kd malaria antigen expressed in the ...
Adhesion of P. falciparum-infected red blood cells to CD36 is enhanced by the cerebral malaria-protective SAO trait . Higher ... Microscopic parasites (like viruses, protozoans that cause malaria, and others) cannot replicate on their own. They replicate ... In malaria, as in other diseases, innate immunity leads into, and stimulates, adaptive immunity. One of the key reasons for the ... Rare mutations of glycophorin A and B proteins are also known to mediate resistance to P. falciparum. Human leucocyte antigen ( ...
Development of genetic resistance to malaria[edit]. Microscopic parasites, like viruses, protozoans that cause malaria, and ... a balanced polymorphism protective against high parasitemias and thus severe P. falciparum malaria". Blood. 100 (4): 1172-6. ... Gerbich antigen receptor negativity[edit]. Main article: Gerbich antigen system. The Gerbich antigen system is an integral ... In malaria, as in other diseases, innate immunity leads into, and stimulates, adaptive immunity. ...
... and Plasmodium falciparum are some of the most well studied examples of protozoan parasites that exhibit antigenic variation. ... The T. brucei parasite has evolved an elegant mechanism to display a completely new coat of VSG antigen, rendering it once ... Plasmodium falciparum, the major etiologic agent of human malaria, has a very complex life cycle that occurs in both humans and ... In individuals who express a protective HLA B*27 allele, the first mutation that occurs in the Gag epitope KK10 is at position ...
2002). "Genome sequence of the human malaria parasite Plasmodium falciparum". Nature. 370 (6906): 1543. doi:10.1038/nature01097 ... Nussenzweig R, Vanderberg J, Most H, Orton C (1967). "Protective immunity produced by the injection of x-irradiated sporozoites ... 2005). "Towards an RTS,S-based, multi-stage, multi-antigen vaccine against falciparum malaria: progress at the Walter Reed Army ... Infectious diseases - Parasitic disease: protozoan infection: Excavata (A06-A07, B55-B57, 007, 085-086) ...
... (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 parasite's 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, ...
Plasmodium falciparum võib osadel inimestel osade emaste hallasääskede vereimemise (toidukorra) ajal süljepiiskadega ühelt inimeselt teisele kanduda ja Plasmodium falciparum-malaariat põhjustada. Enne ülekannet asub Plasmodium falciparum nakatunud emaste sääskede süljenäärmetes - sporozoiidi staadiumis. Sääse vereimemise ('vereeine') ajal püüab ta pistekohta pisut sülge pritsida, sülg sisaldab verejooksu tõkestavaid ja põletikuvastaseid ensüüme, mis takistavad vere hüübimist ja püüavad valu vaigistada. Pikka aega arvati ,et sääsepiste võib sisaldada 5-200 sporozoiiti, mis pääsevad inimese vereringesse - ringlevad mõne minuti ja jõuavad hepatotsüütidesse. Hiljutised uuringud aga näitavad, et moskiito saadab plasmoodumi sporozoiidid naha sisse, kus need võivad olla ligi 6 tundi ja ligi 1/3 neist kes lahkuvad pistekohast sisenevadlümfiringesse ja pääsevad kohalikesse lümfisõlmedesse, teised aga liigutavad end ussitaoliselt vereringesse ja liiguvad ka ...
Plasmodium falciparum is a protozoan parasite, one of the species of Plasmodium which cause malaria in humans. It is transmitted by the female Anopheles mosquito. P. falciparum is the most dangerous of these infections as P. falciparum (or malignant) malaria has the highest rates of complications and mortality. There are about 200 species in the genus Plasmodium, divided into 15 sub-genera. The parasites are partners in a complex co-evolution with mosquitos and land vertebrate species.[1] ...
The genus Plasmodium consists of all eukaryotes in the phylum Apicomplexa that both undergo the asexual replication process of merogony inside host red blood cells and produce the crystalline pigment hemozoin as a byproduct of digesting host hemoglobin.[2] Plasmodium species contain many features that are common to other eukaryotes, and some that are unique to their phylum or genus. The Plasmodium genome is separated into 14 chromosomes contained in the nucleus. Plasmodium parasites maintain a single copy of their genome through much of the life cycle, doubling the genome only for a brief sexual exchange within the midgut of the insect host.[3] Attached to the nucleus is the endoplasmic reticulum (ER), which functions similarly to the ER in other eukaryotes. Proteins are trafficked from the ER to the Golgi apparatus which generally consists of a single membrane-bound compartment in Apicomplexans.[4] From here proteins are trafficked to various cellular compartments or to the ...
Evolutionary relationships of species within the genus Plasmodium have been controversial.[6] Plasmodium species were originally divided by morphology, life-cycle characteristics, and host species. However, modern molecular approaches for determining evolutionary relationships have given results which conflict with older classification methods.[6] Many attempts to clarify Plasmodium taxonomy with molecular methods have also run into technical challenges. Ribosomal RNA sequencing, which is often used in other organisms to determine evolutionary relationships, is challenging to interpret from Plasmodium species as they maintain several different copies of ribosomal RNA which are expressed at different stages of the life cycle and which may be able to recombine with one another.[6] Another commonly used marker for evolutionary studies has been the circumsporozoite protein (CSP) which is present in all Plasmodium species.[6] However, analyses of CSP sequences are complicated by the fact that the ...
... s are a class of at least 10 enzymes (EC 3.4.23.38 and EC 3.4.23.39) produced by the Plasmodium falciparum parasite. There are ten different isoforms of these proteins and ten genes coding them respectively in Plasmodium (Plm I, II, III, IV, V, VI, VII, IX, X and HAP). It has been suggested that the plasmpesin family is smaller in other human Plasmodium species. Expression of Plm I, II, IV, V, IX, X and HAP occurs in the erythrocytic cycle, and expression of Plm VI, VII, VIII, occurs in the exoerythrocytic cycle. Through their haemoglobin-degrading activity, they are an important cause of symptoms in malaria sufferers. Consequently, this family of enzymes is a potential target for antimalarial drugs. Plasmepsins are aspartic acid proteases, meaning their active site contains two aspartic acid residues. These two aspartic acid residue act respectively as proton donor and proton acceptor, catalysing the hydrolysis of ...
... s are cellular organs, or organelles, possessed by Apicomplexa protozoans that are restricted to the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron microscopy they have an electron-dense matrix due to the high protein content. They are specialized secretory organelles important for gliding motility and host cell invasion. These organelles secrete several proteins such as the Plasmodium falciparum apical membrane antigen-1, or PfAMA1, and Erythrocyte family antigen, or EBA, family proteins. These proteins specialize in binding to erythrocyte surface receptors and facilitating erythrocyte entry. Only by this initial chemical exchange can the parasite enter into the erythrocyte via actin-myosin motor complex. It has been posited that this organelle works cooperatively with its counterpart organelle, the rhoptry, which also is a secretory organelle. It is possible that, while ...
... (GYPC; CD236/CD236R; glycoprotein beta; glycoconnectin; PAS-2') plays a functionally important role in maintaining erythrocyte shape and regulating membrane material properties, possibly through its interaction with protein 4.1. Moreover, it has previously been shown that membranes deficient in protein 4.1 exhibit decreased content of glycophorin C. It is also an integral membrane protein of the erythrocyte and acts as the receptor for the Plasmodium falciparum protein PfEBP-2 (erythrocyte binding protein 2; baebl; EBA-140). The antigen was discovered in 1960 when three women who lacked the antigen made anti-Gea in response to pregnancy. The antigen is named after one of the patients - a Mrs Gerbich. The following year a new but related antigen was discovered in a Mrs Yus for whom an antigen in this system is also named. In 1972 a numerical system for the antigens in this blood group was introduced. Despite the similar names glycophorin C and D are unrelated to the ...
Some protists reproduce sexually using gametes, while others reproduce asexually by binary fission.. Some species, for example Plasmodium falciparum, have extremely complex life cycles that involve multiple forms of the organism, some of which reproduce sexually and others asexually.[37] However, it is unclear how frequently sexual reproduction causes genetic exchange between different strains of Plasmodium in nature and most populations of parasitic protists may be clonal lines that rarely exchange genes with other members of their species.[38]. Eukaryotes emerged in evolution more than 1.5 billion years ago.[39] The earliest eukaryotes were likely protists. Although sexual reproduction is widespread among extant eukaryotes, it seemed unlikely until recently, that sex could be a primordial and fundamental characteristic of eukaryotes. A principal reason for this view was that sex appeared to be lacking in certain pathogenic protists whose ancestors branched off early from the eukaryotic ...
Some protists reproduce sexually using gametes, while others reproduce asexually by binary fission. Some species, for example Plasmodium falciparum, have extremely complex life cycles that involve multiple forms of the organism, some of which reproduce sexually and others asexually.[37] However, it is unclear how frequently sexual reproduction causes genetic exchange between different strains of Plasmodium in nature and most populations of parasitic protists may be clonal lines that rarely exchange genes with other members of their species.[38]. Eukaryotes emerged in evolution more than 1.5 billion years ago.[39] The earliest eukaryotes were likely protists. Although sexual reproduction is widespread among extant eukaryotes, it seemed unlikely until recently, that sex could be a primordial and fundamental characteristic of eukaryotes. A principal reason for this view was that sex appeared to be lacking in certain pathogenic protists whose ancestors branched off early from the eukaryotic ...
Some protists reproduce sexually using gametes, while others reproduce asexually by binary fission. Some species, for example Plasmodium falciparum, have extremely complex life cycles that involve multiple forms of the organism, some of which reproduce sexually and others asexually.[42] However, it is unclear how frequently sexual reproduction causes genetic exchange between different strains of Plasmodium in nature and most populations of parasitic protists may be clonal lines that rarely exchange genes with other members of their species.[43]. Eukaryotes emerged in evolution more than 1.5 billion years ago.[44] The earliest eukaryotes were likely protists. Although sexual reproduction is widespread among extant eukaryotes, it seemed unlikely until recently, that sex could be a primordial and fundamental characteristic of eukaryotes. A principal reason for this view was that sex appeared to be lacking in certain pathogenic protists whose ancestors branched off early from the eukaryotic ...
CD36 - мембранный белок, экспрессированный на поверхности клеток нескольких типов, особенно макрофагах; относится к классу B скэвенджер-рецепторов, компонент системы врождённого иммунитета. Связывает эритроциты, заражённые паразитическим Plasmodium falciparum, окисленные липопротеины низкой плотности, фосфолипиды и жирные кислоты. Кроме этого, CD36, экспрессированный на поверхности эпителия вкусовых сосочков языка, является рецептором, связывающим жирные кислоты пищи и участвующим в формировании «вкуса жира». ...
Plasmodium är ett släkte protister som sprids med myggor till olika värddjur. Här återfinns bland annat de arter som hos människan ger upphov till malaria.. Plasmodierna sprids genom blodsugande myggor.. ...
The results emphasize the importance of spleen function in protective immunity to the polymorphic malaria parasite. ... Adolescent, Adult, Aged, Animals, Antigens; Protozoan/genetics, Child, Child; Preschool, Cross-Cultural Comparison, Cross- ... Falciparum/*ethnology/parasitology, Mali, Middle Aged, Plasmodium falciparum/*genetics, Protozoan Proteins/genetics, ... Spleen enlargement and genetic diversity of Plasmodium falciparum infection in two ethnic groups with different malaria ...
... we have made far fewer advances in using this information to identify targets of protective immunity. Epidemiological models ... We apply this concept to the AMA-1 protein of the malaria parasite Plasmodium falciparum and find evidence of epitopes among ... Antigens, Protozoan / genetics* * Antigens, Protozoan / immunology* * Epitopes / genetics* * Epitopes / immunology* * Genetics ... Reverse immunodynamics: a new method for identifying targets of protective immunity Sci Rep. 2019 Feb 15;9(1):2164. doi: ...
... venular endothelium or uninfected red cells is strongly implicated in the pathogenesis of severe Plasmodium falciparum malaria ... Here we use sequential cloning of P. falciparum by micromanipulation to investigate the ability of a parasite to switch ... Antigens, Protozoan / genetics * Cell Adhesion * Endothelium, Vascular / physiology * Erythrocytes / immunology * Erythrocytes ... demonstrate serological diversity in field isolates and may also be a target of the host-protective immune response. ...
Thus, cell-mediated immune responses appear to play a dual role in malaria: mediating protective immunity on the one hand, and ... falciparum antigens in PBMCs from Mossi individuals, Treg cell depletion did not alter parasite-specific proliferation rates of ... is transmitted to vertebrate hosts by the bite of female Anopheles mosquitos that are infected with protozoan parasites of the ... which is characterised by low parasite burdens rather than sterilising immunity. The reason why malaria parasites persist under ...
A specific, balanced and, to an extent, protective immunity will develop over time in response to repeated parasite encounters ... The cellular production of pro-inflammatory and regulatory cytokines and chemokines in response to helminth, protozoan antigens ... Cytokine and chemokine production was distinctively inducible by parasite antigens; pro-inflammatory Th2-type cytokine IL-19 ... Mansonella perstans filariasis was only present in adults (24%) and the elderly (25%). Two or more parasite infections were ...
214 blood samples were collected from Bioko Island patients with P. falciparum malaria between 2011 and 2017. A fragment ... These results may provide significant value in the design of a malaria vaccine based on this antigen. ... is a promising candidate antigen for a blood-stage malaria vaccine. However, antigenic variation and diversity of PfAMA-1 are ... still major problems to design a universal malaria vaccine based on this antigen, especially against domain I (DI). Detail ...
Microbial Immunity and Vaccines. Generation of Cross-Protective Antibodies against Plasmodium falciparum Sequestration by ... Invasion Pathways and Malaria Severity in Kenyan Plasmodium falciparum Clinical Isolates Anne-Marie Deans, Susana Nery, David J ... Proteolytic Processing of the Cryptosporidium Glycoprotein gp40/15 by Human Furin and by a Parasite-Derived Furin-Like Protease ... Mimotopes of Apical Membrane Antigen 1: Structures of Phage-Derived Peptides Recognized by the Inhibitory Monoclonal Antibody ...
Moreover, malaria control and elimination is hampered by rapid development of resistance by the parasite and the vector to ... We conclude with our views on some important future directions of research into P. falciparum sexual stage immunity relevant to ... Moreover, malaria control and elimination is hampered by rapid development of resistance by the parasite and the vector to ... We conclude with our views on some important future directions of research into P. falciparum sexual stage immunity relevant to ...
... human viruses to bacteria to fungi and unicellular protozoan parasites, passively evade immune surveillance ... in the malarial parasites mediate epigenetic regulation in the malaria parasite Plasmodium falciparum. ... long protective immunity against several pathogens. Key Concepts:. * Antigenic variation is a major mechanism of passively ... 2011) Plasmodium falciparum serine repeat antigen 5 (SE36) as a malaria vaccine candidate. Vaccine 29(35): 5837-5845. ...
In the present research, the surface antigen gene of E. maxima (EmSAG) was cloned, and the ability of EmSAG to stimulate ... stoichiometry of glycosylphosphatidylinositol-anchored membrane proteins of the human malaria parasite Plasmodium falciparum. ... The genome of the protozoan parasite Cystoisospora suis and a reverse vaccinology approach to identify vaccine candidates. Int ... Protective immunity against Eimeria maxima induced by vaccines of Em14-3-3 antigen. Vet Parasitol. 2018;253:79-86.View Article ...
As expected, two thirds of the papers are focused on protozoan parasites, 50% of which are on Toxoplasma gondii as a model ... host-parasite responses and interactions, and up-to-date control measures. Such an accomplishment is unattainable without the ... where malarial parasites, soil-transmitted helminths, bacteria and viruses are the causes for chronic infections in a large ... advances in immunoparasitology and has been concluded with more than 30 high quality papers encompassing aspects of parasite ...
... the vaccine gave protective immunity to 7 out of 8 volunteers when challenged with P. falciparum. RTS,S/AS01 (commercial name ... Unlike other antigens of the malaria parasite which are often genetically diverse, the PfRH5 antigen appears to have little ... By their very nature, protozoa are more complex organisms than bacteria and viruses, with more complicated structures and life ... Researchers from Rhode Island Hospital identified Plasmodium falciparum PfSEA-1, a 244 kd malaria antigen expressed in the ...
... does not exclude a protective role for antigens normally expressed by hepatic stage parasites. The nature of the antigens ... Clyde DF (1975) Immunization of man against falciparum and vivax malaria by use of attenuated sporozoites. Am J Trop Med Hyg 24 ... 1 contributes to resistance against experimental infection with the protozoan parasite Trypanosoma cruzi. Vaccine 30: 2882‐ ... Scheller LF, Azad AF (1995) Maintenance of protective immunity against malaria by persistent hepatic parasites derived from ...
... coli and other species prompts a potent immune response against malaria-causing parasites in mice. ... A carbohydrate antigen found on cells of E. ... falciparum, which causes malaria in humans. Mice with gut flora ... Gut Microbes Trigger Malaria-Fighting Antibodies. A carbohydrate antigen found on cells of E. coli and other species prompts a ... B. Yilmaz et al., "Gut microbiota elicits a protective immune response against malaria transmission," Cell, doi:10.1016/j.cell. ...
... falciparum erythrocyte membrane protein 1 (P f EMP1) variant VAR2CSA, that are targets for protective immunity has strengthened ... DNA Vaccines against Protozoan Parasites: Advances and Challenges.. J Biomed Biotechnol. 2007;2007(6):90520.. Over the past 15 ... In this paper, we review the molecular basis of malaria pathogenesis attributable to the erythrocyte stages of the parasites, ... Demonstrating that parasites causing PAM express specific variant surface antigens (VSA(PAM)), including the P. ...
Adhesion of P. falciparum-infected red blood cells to CD36 is enhanced by the cerebral malaria-protective SAO trait . Higher ... Microscopic parasites (like viruses, protozoans that cause malaria, and others) cannot replicate on their own. They replicate ... In malaria, as in other diseases, innate immunity leads into, and stimulates, adaptive immunity. One of the key reasons for the ... Rare mutations of glycophorin A and B proteins are also known to mediate resistance to P. falciparum. Human leucocyte antigen ( ...
Plasmodium falciparum malaria transmission-blocking immunity under conditions of low endemicity as in Sri Lanka. Parasite ... Malaria transmission-blocking antigen, Pfs230, mediates human red blood cell binding to exflagellating male parasites and ... Apoptosis in the malaria protozoan, Plasmodium berghei: a possible mechanism for limiting intensity of infection in the ... protective responses, which could be used to design malaria vaccines (Alonso et al. 2011a). Several of the candidate genes have ...
Understanding how protective immunity can be induced, as well as knowing the mechanisms used by these intracellular parasites ... Acquired immunity to malaria is frequently described as being either antiparasite immunity, encompassing effector mechanisms ... This chapter investigates the acquired immune responses important in the control of four intracellular protozoans: Plasmodium, ... immunity. It is widely believed that acquired immunity to malaria rapidly wanes in the absence of frequent reinfection. A ...
... structural properties and antigens capable of activating the immunological mechanisms for the induction of protective immunity ... It was identified immunogenic proteins essential for parasite survival in the host, two of which (RAP-2 and RAP-3) are already ... The determination of anti-P. falciparum IgG antibodies was performed by an ELISA validated and optimized for this study. Sera ... The study was conducted in 227 individuals with imported malaria and 23 healthy individuals who had never been in areas endemic ...
Malaria is a common protozoan infection that is responsible for enormous worldwide mortality and economic burden on the society ... Episodes of Plasmodium falciparum (Pf) caused CM may be lethal, while survivors are likely to suffer from persistent ... We have also emphasized how pathogenesis of the disease is effected by the parasite and host responses including blood brain ... Based on a few recent studies carried out in experimental mouse malaria models, we propose a basis for the neurological ...
Development of genetic resistance to malaria[edit]. Microscopic parasites, like viruses, protozoans that cause malaria, and ... a balanced polymorphism protective against high parasitemias and thus severe P. falciparum malaria". Blood. 100 (4): 1172-6. ... Gerbich antigen receptor negativity[edit]. Main article: Gerbich antigen system. The Gerbich antigen system is an integral ... In malaria, as in other diseases, innate immunity leads into, and stimulates, adaptive immunity. ...
The concept that hypnozoites give rise to relapses in Plasmodium vivax and Plasmodium ovale malaria has become dogma. However, ... contemporary research findings that hypnozoites are not necessarily the origin of all relapse-like recurrences of malaria... ... Do hypnozoites cause relapse in malaria? Trends Parasitol. 2015 Mar 25; Authors: Markus MB Abstract ... The N-Terminal Region of Plasmodium falciparum MSP10 Is a Target of Protective Antibodies in Malaria and Is Important for ...
Along with antigens of particular importance in the life cycles of parasites, the vector ligands that interact with pathogens ... Článek Tailored Immune Responses: Novel Effector Helper T Cell Subsets in Protective Immunity ... 2007) Disruption of Plasmodium falciparum development by antibodies against a conservedmosquito midgut antigen. Proc Natl Acad ... Malaria Journal 6: 107.. 38. ChowdhuryDR, AngovE, KariukiT, KumarN (2009) A potent malaria transmission blocking vaccine based ...
... where no Plasmodium falciparum malaria case had been reported since 2006. To identify the source of the parasite causing this ... Protective Antibodies against Placental Malaria and Poor Outcomes during Pregnancy, Benin [PDF - 1.07 MB - 11 pages] N. Ndam et ... Antibody-mediated immunity to placental malaria is acquired during successive pregnancies, but the target of VAR2CSA-specific ... Binding is mediated by VAR2CSA, a parasite antigen coded by the var gene, which interacts with chondroitin sulfate A (CSA). ...
Malaria transmission occurs in large areas of Central and South America, Africa, Asia, Eastern Europe, and the South Pacific. ... Malaria is caused by Plasmodium parasites. Transmission requires an intermediate mosquito (anopheles) host, which is found ... Malaria is caused by Plasmodium parasites. Four Plasmodium species (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale ... which determines the degree of protective immunity acquired and, in turn, the clinical disease profile. ...
  • Such immunity, the researchers showed, requires the activation of complement, a set of signaling proteins that recruits neutrophils to attack and kill invading pathogens. (the-scientist.com)
  • Since malaria infects red blood cells, these genetic changes are most commonly alterations to molecules essential for red blood cell function (and therefore parasite survival), such as hemoglobin or other cellular proteins or enzymes of red blood cells. (wikipedia.org)
  • Therefore, the objective of this study is to evaluate the serological reactivity of sera from individuals with imported malaria and identify major immunogenic proteins. (biomedcentral.com)
  • Sera showing higher reactivity to anti- P. falciparum by ELISA were analysed by immunoblotting and immunogenic proteins were identified by mass spectroscopy. (biomedcentral.com)
  • It was identified immunogenic proteins essential for parasite survival in the host, two of which (RAP-2 and RAP-3) are already described in the literature as proteins that play an important role in the invasion of erythrocytes by extracellular merozoites. (biomedcentral.com)
  • Small molecule-based inhibition of MEK1/2 proteins dampens inflammatory responses to malaria, reduces parasite load, and mitigates pathogenic outcomes. (semanticscholar.org)
  • This multi-step progression involves interactions between parasite and human host proteins. (medworm.com)
  • The CD4 T cell response to the exon 2 and duffy binding-like domain proteins was significantly greater in malaria-exposed donors than in unexposed Europeans, which suggests that these regions contain peptides recognized by T cells, which thus may be useful as components of a vaccine. (ox.ac.uk)
  • The survival and development of the parasite within the host's intracellular and extracellular environments, is made possible by a toolkit of more than 5,000 genes and their specialized proteins" (Malaria Site). (wordpress.com)
  • We discuss here how this burden has driven the natural selection of numerous polymorphisms in the genes encoding hemoglobin and other erythrocyte proteins and some effectors of immunity. (jci.org)
  • Assigning function to orphan membrane transport proteins and prioritizing candidates for detailed biochemical characterization remain fundamental challenges and are particularly important for medically relevant pathogens, such as malaria parasites. (nature.com)
  • Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan , bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host immune response . (wikipedia.org)
  • As a result of its mainly intracellular niche, parasitized host cells which display parasite proteins must be modified to prevent destruction by the host immune defenses. (wikipedia.org)
  • The increasing challenges posed by the emergence of resistance to antimalarials by malaria parasites and to insecticides by mosquitoes ( 2 , 3 ) suggest the need for additional interventions aiming at transmission reduction such as vaccines. (frontiersin.org)
  • Antigenic variation has serious public health consequences, for example, the current human immunodeficiency virus pandemic and the looming influenza pandemic, as well as a significant challenge to developing vaccines capable of eliciting long‐lasting or life‐long protective immunity against several pathogens. (els.net)
  • These less virulant viruses may serve as antigens for the candidate vaccines. (els.net)
  • The difficulty in developing protective vaccines stems from the ability of parasites to evolve and evade host immune surveillance by genetic exchange among the parasites, acquisition of resistant genotypes in the insect vector, and plasticity in adaptation in new environments ( Radwanska et al. ). (frontiersin.org)
  • Although these candidates, collectively called TB vaccines (TBV), would not directly stop malaria from infecting individuals, but would stop transmission from infected person to non-infected person. (bioline.org.br)
  • Vaccines are a promising avenue for the future of malaria control, because how cost effective vaccines have proven to be for controlling other pathogens and because they would act as a complement to the current antimalarial arsenal (Richie & Saul 2002, Moorthy et al. (bioline.org.br)
  • Understanding how protective immunity can be induced, as well as knowing the mechanisms used by these intracellular parasites to avoid destruction, is critical for the development of new therapies as well as vaccines. (asmscience.org)
  • While several malaria vaccines are under development, none is available yet. (europa.eu)
  • If IG needs to be administered because of imminent exposure to disease, live virus vaccines may be administered simultaneously with IG recognizing that vaccine-induced immunity may be compromised. (cdc.gov)
  • Elimination of malaria will probably ultimately depend on the development of highly effective vaccines. (pubmedcentralcanada.ca)
  • Prime-boost vectored malaria vaccines: progress and prospects. (ox.ac.uk)
  • Although DNA vectored vaccines used alone were poorly immunogenic and not protective, high levels of parasite clearance in the liver has been achieved with viral vectored vaccines used in heterologous prime-boost regimes. (ox.ac.uk)
  • Field-based malaria vaccine studies are in progress to validate the establishment of this cellular response as a possible in vitro correlate of protective immunity to exo-erythrocytic stage malaria vaccines. (jimmunol.org)
  • Because VK210 and VK247 variants are both globally distributed [ 11 - 16 ], PvCSP-based vaccines need to induce protective immune responses to them both. (beds.ac.uk)
  • The same authors speculated that full-length PvCSP vaccines would enhance the quality, magnitude, and breadth of protective antibody and T cell responses. (beds.ac.uk)
  • However, antigenic variation and diversity of Pf AMA-1 are still major problems to design a universal malaria vaccine based on this antigen, especially against domain I (DI). (biomedcentral.com)
  • Antigenic variation is the means by which a number of highly pathogenic microorganisms, ranging from the electronmicroscopic human viruses to bacteria to fungi and unicellular protozoan parasites, passively evade immune surveillance. (els.net)
  • Antigenic variation is exhibited by a number of highly pathogenic microorganisms including human viruses, bacteria, fungi and unicellular protozoans. (els.net)
  • Conversely, parasites themselves are phylogenetically diverse, target a range of different tissues, and have evolved numerous alternative strategies to evade or inhibit protective immune responses by strategies, such as antigenic variation, molecular mimicry or affecting antigen processing and presentation. (omicsonline.org)
  • Thus, genome architecture may also be a key regulator of antigenic variation, yet the causal links between genome architecture and the expression of antigens have not been studied systematically. (europa.eu)
  • I have adapted both Hi-C and CRISPR-Cas9 technology to the protozoan parasite Trypanosoma brucei, one of the most important model organisms to study antigenic variation. (europa.eu)
  • Antigenic variation is employed by a number of different protozoan parasites. (wikipedia.org)
  • Moreover, splenomegaly was increased in individuals with clinical malaria in the Dogon, odds ratio 3.67 (95% CI 1.65-8.15, P = 0.003), but not found in the Fulani, 1.36 (95% CI 0.53-3.48, P = 0.633). (diva-portal.org)
  • Annually, 300-500 million clinical malaria cases result in approximately 1 million deaths with the primary mortality occurring in children under the age of five in sub-Saharan Africa (Ref. 1 ). (pubmedcentralcanada.ca)
  • In this review we consider the role of innate and adaptive immune responses in terms of (i) protection from clinical malaria (ii) their potential role in immunopathology and (iii) the subsequent development of clinical immunity. (naver.com)
  • It is estimated that 247 million cases of clinical malaria occur every year and nearly 1 million deaths due to malaria are reported each year most of them in children in equatorial Africa (WHO, 2008). (mynursinghomeworks.com)
  • The reason why children from malaria endemic regions have a higher prevalence of endemic Burkitt's lymphoma (eBL) compared to children from regions where malaria is unstable is not fully understood but studies by Moorman et al, (2007), have implicated the elevated viral loads in children having acute clinical malaria and interference in the B cell subset as a possible mechanism for the pathogenesis of eBL. (mynursinghomeworks.com)
  • Later, Jarra (1983) postulated that the acquisition of immunity against blood stage parasites would not be possible without the development of a simultaneous autoimmune response against erythrocytes, even if this resulted in immunopathology. (fiocruz.br)
  • Here, we present a detailed protocol for carrying out the RNA-FISH methodology for analysis of var gene transcription in single-nuclei of P. falciparum infected human erythrocytes. (jove.com)
  • The inhibition of maturation of DC is reversible, parasite-specific and increases with the stage of parasite development, with complete inhibition induced by schizonts (mature infected erythrocytes). (beds.ac.uk)
  • While in the human host, the parasite spends most of its life cycle within hepatic cells and erythrocytes (in contrast to T. brucei which remains extracellular). (wikipedia.org)
  • The World Malaria Report 2018 draws on data from 87 countries and areas with ongoing malaria transmission. (biomedcentral.com)
  • According to the 2011 World Malaria Report, there were an estimated 216 million episodes of malaria and 655,000 worldwide malaria deaths in 2010, 91% of which were in Africa [ 2 ]. (biomedcentral.com)
  • The World Malaria Report 2013 disclosed that approximately 3 million people die of this disease every year, accounting for five percent of all fatalities in the world, while being the leading cause of children's death. (wordpress.com)
  • The Fulani had lower parasite prevalence and densities and more prominent spleen enlargement. (diva-portal.org)
  • Spleen rate increased with parasite prevalence, density and number of co-infecting clones in asymptomatic Dogon. (diva-portal.org)
  • The Bioko Island Malaria Control Project (BIMCP) implemented by the U.S. NGO, Medical Care Development International (MCDI) and the Ministry of Health and Social Welfare of the Government of Equatorial Guinea, has reduced malaria prevalence from 74% (by thick blood smear) in 2003 to 11% (by rapid diagnostic test) in 2017 in children 2 to 14 years of age. (biomedcentral.com)
  • however, the risk of malaria can change rapidly and from year to year (because of changes in local weather conditions, mosquito vector density, and prevalence of infection). (cdc.gov)
  • There were numerous studies on prevalence of intestinal parasites among wild rats in Malaysia but none has reported E. histolytica. (bvsalud.org)
  • The cellular production of pro-inflammatory and regulatory cytokines and chemokines in response to helminth, protozoan antigens and ubiquitous allergens were studied in neonates, children, adults and the elderly. (biomedcentral.com)
  • P. falciparum is particularly troublesome because the infected RBCs are prevented from entering the spleen by 'sequestration' - deformities in the red cell membrane which results in adhesions to capillary walls resulting in hypoxia to downstream tissues and potentially the relapse of increased cytokines. (lifeinthefastlane.com)
  • The presentation of autoantigens by antigen-presenting cells (APCs), such as macrophages and dendritic cells, to T cells leads to the maturation and release of proinflammatory cytokines. (kjim.org)
  • We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites' replication. (blogspot.com)
  • Recently, the mutually exclusive transcription paradigm has been called into doubt by transcription assays based on individual P. falciparum transcript identification in single infected erythrocytic cells using RNA fluorescent in situ hybridization (FISH) analysis of var gene transcription by the parasite in individual nuclei of P. falciparum IE 1 . (jove.com)
  • citation needed] The parasite induces two main response types from the human immune system. (wikipedia.org)
  • It's harder for children to mount reactions against carbohydrate antigens for some reason," said Ajit Varki of the University of California, San Diego, who studies another non-human carbohydrate, the Neu5Gc form of sialic acid. (the-scientist.com)
  • Malaria has placed the strongest known selective pressure on the human genome since the origination of agriculture within the past 10,000 years. (wikipedia.org)
  • If the change is in the gamete, that is, the sperm or egg that join to form a zygote that grows into a human being, the protective mutation will be inherited. (wikipedia.org)
  • The parasite induces two main response types from the human immune system. (worldheritage.org)
  • In the case of human malaria, the definitive host is often referred to as the vector. (wordpress.com)
  • Consequently, the Anopheles will transmit the infective form of the parasite into the human blood stream through a bite with its saliva. (wordpress.com)
  • The immune system 1 acts like a protective physical and biochemical bubble around the human body, protecting against everyday germs (Fig. 1). (answersingenesis.org)
  • The recently growing support from international organizations and governments of some endemic countries is warmly welcome, and should be optimally exploited in the various approaches to drug and insecticide research and development to overcome the burden of these prevalent diseases, especially malaria, leishmaniasis, Human African Trypanosomiasis (HAT), and Chagas disease. (biomedcentral.com)
  • Diseases caused by Plasmodia (malaria), and three major trypanosomatid diseases [leishmaniasis, African Human Trypanosomiasis (HAT) and Chagas disease] represent a major public health concern in the tropics. (biomedcentral.com)
  • Comparison of the RMP genomes with the genome of the human malaria parasite P. falciparum and RNA-seq mapping permitted gene annotation at base-pair resolution. (biomedcentral.com)
  • Such vectored vaccination regimes represent one of only two approaches that have induced repeatable partial efficacy in human P. falciparum subunit vaccine trials. (ox.ac.uk)
  • Human pregnancy-associated malaria-specific B cells target polymorphic, conformational epitopes in VAR2CSA. (nih.gov)
  • Flow cytometry analysis of human VSA-specific plasma IgG reactivity with the surface of P. falciparum -IEs. (nih.gov)
  • Malaria is a major disease in the tropics where chemotherapy remains the main mode of treatment and as such the rise and spread of drug-resistant malaria can lead to human tragedy. (usda.gov)
  • SUMMARY Throughout history malaria has proved to be a significant threat to human health. (naver.com)
  • Our data show that antigens at the parasitized cell surface undergo clonal variation in vitro in the absence of immune pressure at the rate of 2% per generation with concomitant modulations of the adhesive phenotype. (nih.gov)
  • In vitro stimulation was performed using irradiated parasites (220 krads). (asm.org)
  • METHODS: A total of 674 filter paper blood samples were collected from the National Malaria Diagnosis Reference Laboratory of China in 2012 and 2018. (bvsalud.org)
  • RESULTS: Among the 674 imported P. falciparum malaria cases in China in 2012 and 2018, 99.5% (644/674) were from Africa, which were predominantly from western and central Africa (80.4%, 518/644), and 4.5% (30/674) from Southeast Asia and Oceania (Papua New Guinea). (bvsalud.org)
  • In rural sub-Saharan Africa, endemic populations are often infected concurrently with several intestinal and intravascular helminth and protozoan parasites. (biomedcentral.com)
  • Malaria is endemic in Equatorial Guinea, a country in Central West Africa with a population of around 1 million inhabitants. (biomedcentral.com)
  • 2008). P. falciparum is responsible for 80% of the 300-500 million malaria cases reported every year, most of which (80%) occur in Africa. (bioline.org.br)
  • Malaria is currently endemic in the tropical zones with extensions into the subtropical regions of Asia, Africa, South and Central America. (biomedcentral.com)
  • Malaria transmission occurs in large areas of Central and South America, Africa, Asia, Eastern Europe, and the South Pacific. (europa.eu)
  • In endemic areas such as tropical Africa, the incidence of malaria is higher in children younger than five years, due to low acquired immunity. (europa.eu)
  • Today, nearly half of the world's population is at risk from malaria - it kills more than 400,000 people a year, most of them in Africa, where a child dies every two minutes from the disease. (earthinfonow.com)
  • Malaria transmission occurs in large areas of Africa, Latin America, parts of the Caribbean, Asia (including South Asia, Southeast Asia, and the Middle East), Eastern Europe, and the South Pacific ( Maps 4-08 and 4-09 ). (cdc.gov)
  • Malaria is a deadly infectious disease and one of the main health problems facing developing countries in Sub-Saharan Africa (SSA) and Asia. (biomedcentral.com)
  • malaria does not occur in the United States, many people in Africa, Asia, and South America do get malaria. (bioportfolio.com)
  • In such situations, which prevail in much of sub-Saharan Africa and parts of Oceania, the acute clinical disease described above is almost always confined to young children who suffer high parasite densities and acute clinical disease. (wordpress.com)
  • The Roll Back Malaria Programme, for example, emphasizes the use of insecticide treated bednets in Africa and targets a 30-fold increase in treated bednet use by 2007. (who.int)
  • Malaria remains one of the most serious public health problems not only in endemic countries but also in non-endemic areas where the increasing number of imported malaria cases is worrying [ 3 ]. (biomedcentral.com)
  • In non-endemic countries for malaria, the diagnosis and adequate treatment is delayed due to the fact that malaria is infrequent in these countries, which can make these cases fatal to patients. (biomedcentral.com)
  • Malaria diagnosis: still a challenge in non-endemic countries. (semanticscholar.org)
  • In Europe, malaria chemoprophylaxis is only for travellers to malaria endemic countries, which are classified in three (or four) groups, to determine which drug is recommended for chemoprophylaxis. (europa.eu)
  • Optimism is justified for several reasons, the first of these being that individuals who are exposed to the parasite in endemic countries develop acquired immunity against disease and death. (worldheritage.org)
  • Travelers going to malaria-endemic countries are at risk for contracting the disease, and almost all of the approximately 1,700 cases per year of malaria in the United States are imported. (cdc.gov)
  • Goa, India) and OptiMAL method for the health infrastructure coupled with political detection of pLDH (DiaMed, Cressier sur instability in malaria endemic countries, Morat, Switzerland) [ 10,12 ]. (who.int)