Lassa virus: A species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), and the etiologic agent of LASSA FEVER. LASSA VIRUS is a common infective agent in humans in West Africa. Its natural host is the multimammate mouse Mastomys natalensis.Lassa Fever: An acute febrile human disease caused by the LASSA VIRUS.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.Arenaviridae: A family of RNA viruses naturally infecting rodents and consisting of one genus (ARENAVIRUS) with two groups: Old World Arenaviruses (ARENAVIRUSES, OLD WORLD) and New World Arenaviruses (ARENAVIRUSES, NEW WORLD). Infection in rodents is persistent and silent. Vertical transmission is through milk-, saliva-, or urine-borne routes. Horizontal transmission to humans, monkeys, and other animals is important.Guinea: A republic in western Africa, south of SENEGAL and MALI, east of GUINEA-BISSAU. Its capital is Conakry.Arenaviruses, Old World: One of two groups of viruses in the ARENAVIRUS genus and considered part of the Old World complex. It includes LASSA VIRUS and LYMPHOCYTIC CHORIOMENINGITIS VIRUS, although the latter has worldwide distribution now.Arenavirus: The only genus in the family ARENAVIRIDAE. It contains two groups ARENAVIRUSES, OLD WORLD and ARENAVIRUSES, NEW WORLD, which are distinguished by antigenic relationships and geographic distribution.Sierra Leone: A republic in western Africa, south of GUINEA and west of LIBERIA. Its capital is Freetown.RING Finger Domains: A zinc-binding domain defined by the sequence Cysteine-X2-Cysteine-X(9-39)-Cysteine-X(l-3)-His-X(2-3)-Cysteine-X2-Cysteine -X(4-48)-Cysteine-X2-Cysteine, where X is any amino acid. The RING finger motif binds two atoms of zinc, with each zinc atom ligated tetrahedrally by either four cysteines or three cysteines and a histidine. The motif also forms into a unitary structure with a central cross-brace region and is found in many proteins that are involved in protein-protein interactions. The acronym RING stands for Really Interesting New Gene.Vacuoles: Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.Vesicular Transport Proteins: A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.Viral Proteins: Proteins found in any species of virus.Tropical Medicine: The branch of medicine concerned with diseases, mainly of parasitic origin, common in tropical and subtropical regions.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Aedes: A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Murinae: A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.Muridae: A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.Nigeria: A republic in western Africa, south of NIGER between BENIN and CAMEROON. Its capital is Abuja.Rivers: Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).Ejaculatory Ducts: Paired ducts in the human male through which semen is ejaculated into the urethra.Termitomyces: A paleotropical genus of fungi in the family Tricholomataceae. They are obligate symbionts of termites.Aliivibrio salmonicida: A species of gram-negative bacteria in the genus ALIIVIBRIO. Aliivibrio salmonicida is the causative agent of cold water vibriosis, a HEMORRHAGIC SEPTICEMIA of ATLANTIC SALMON.Students, Nursing: Individuals enrolled in a school of nursing or a formal educational program leading to a degree in nursing.Missions and Missionaries: To be used for articles pertaining to medical activities carried out by personnel in institutions which are administered by a religious organization.Virus Diseases: A general term for diseases produced by viruses.Arenaviridae Infections: Virus diseases caused by the ARENAVIRIDAE.Writing: The act or practice of literary composition, the occupation of writer, or producing or engaging in literary work as a profession.Peer Review, Research: The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Hemorrhagic Fevers, Viral: A group of viral diseases of diverse etiology but having many similar clinical characteristics; increased capillary permeability, leukopenia, and thrombocytopenia are common to all. Hemorrhagic fevers are characterized by sudden onset, fever, headache, generalized myalgia, backache, conjunctivitis, and severe prostration, followed by various hemorrhagic symptoms. Hemorrhagic fever with kidney involvement is HEMORRHAGIC FEVER WITH RENAL SYNDROME.Marburg Virus Disease: An RNA virus infection of rhesus, vervet, and squirrel monkeys transmissible to man.Marburgvirus: A genus in the family FILOVIRIDAE consisting of one species (Lake Victoria marburgvirus) with several strains. The genus shows no antigenic cross-reactivity with EBOLAVIRUS.Hemorrhagic Fever, Ebola: A highly fatal, acute hemorrhagic fever, clinically very similar to MARBURG VIRUS DISEASE, caused by EBOLAVIRUS, first occurring in the Sudan and adjacent northwestern (what was then) Zaire.Hemorrhagic Fever, Crimean: A severe, often fatal disease in humans caused by the Crimean-Congo hemorrhagic fever virus (HEMORRHAGIC FEVER VIRUS, CRIMEAN-CONGO).RNA Viruses: Viruses whose genetic material is RNA.Sickle Cell Trait: The condition of being heterozygous for hemoglobin S.Anemia, Sickle Cell: A disease characterized by chronic hemolytic anemia, episodic painful crises, and pathologic involvement of many organs. It is the clinical expression of homozygosity for hemoglobin S.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Hemoglobin, Sickle: An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia.Biological Science Disciplines: All of the divisions of the natural sciences dealing with the various aspects of the phenomena of life and vital processes. The concept includes anatomy and physiology, biochemistry and biophysics, and the biology of animals, plants, and microorganisms. It should be differentiated from BIOLOGY, one of its subdivisions, concerned specifically with the origin and life processes of living organisms.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.Hemorrhagic Fever, American: Diseases caused by American hemorrhagic fever viruses (ARENAVIRUSES, NEW WORLD).Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Junin virus: A species of ARENAVIRUS, part of the New World Arenaviruses (ARENAVIRUSES, NEW WORLD), causing Argentinian hemorrhagic fever. The disease is characterized by congestion, edema, generalized lymphadenopathy and hemorrhagic necrosis and is sometimes fatal.Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Conflict (Psychology): The internal individual struggle resulting from incompatible or opposing needs, drives, or external and internal demands. In group interactions, competitive or opposing action of incompatibles: antagonistic state or action (as of divergent ideas, interests, or persons). (from Merriam-Webster's Collegiate Dictionary, 10th ed)Receptors, Transferrin: Membrane glycoproteins found in high concentrations on iron-utilizing cells. They specifically bind iron-bearing transferrin, are endocytosed with its ligand and then returned to the cell surface where transferrin without its iron is released.Toxoplasma: A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.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.Transferrin: An iron-binding beta1-globulin that is synthesized in the LIVER and secreted into the blood. It plays a central role in the transport of IRON throughout the circulation. A variety of transferrin isoforms exist in humans, including some that are considered markers for specific disease states.