Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biology, veterinary importance and control of certain Nematocera are described and discussed. Culicoides spp. (family Ceratopogonidae) transmit the arboviruses of bluetongue (BT), African horse sickness (AHS), bovine ephemeral fever (BEF) and Akabane. Some other arboviruses have been isolated from these species, while fowl pox has been transmitted experimentally by Culicoides. These insects are vectors of the parasitic protozoans Leucocytozoon caulleryi and Haemoproteus nettionis, and the parasitic nematodes Onchocerca gutturosa, O. gibsoni and O. cervicalis. They also cause recurrent summer hypersensitivity in horses, ponies, donkeys, cattle and sheep. Farm animals can die as a result of mass attack by Simulium spp., which are also vectors of Leucocytozoon simondi, L. smithi and the filariae O. gutturosa, O. linealis and O. ochengi. Venezuelan equine encephalomyelitis (VEE) and Rift Valley fever (RVF) have been isolated from simuliids, and vesicular stomatitis virus New Jersey strain has been replicated in Simulium vittatum. Simuliids are well known as vectors of O. volvulus, the cause of human onchocercosis (river blindness). The family Psychodidae includes the genera Phlebotomus and Lutzomyia (subfamily Phlebotominae), vectors of Leishmania spp. in humans, dogs and other mammals. Vesicular stomatitis virus Indiana strain has been regularly isolated from phlebotomine sandflies. Mass attack by mosquitoes can also prove fatal to farm animals. Mosquitoes are vectors of the viruses of Akabane, BEF, RVF, Japanese encephalitis, VEE, western equine encephalomyelitis, eastern equine encephalomyelitis and west Nile meningoencephalitis, secondary vectors of AHS and suspected vectors of Israel turkey meningoencephalitis. The viruses of hog cholera, fowl pox and reticuloendotheliosis, the rickettsiae Eperythrozoon ovis and E. suis, and the bacterium Borrelia anserina are mechanically transmitted by mosquitoes. These insects also induce allergic dermatitis in horses. They transmit several filarial worms of both animals and humans, and are of great medical importance as vectors of major human diseases, including malaria, yellow fever, dengue fever and many more diseases caused by arboviruses.
 ...
PMID:Nematocera (Ceratopogonidae, Psychodidae, Simuliidae and Culicidae) and control methods. 771 9

The induction and characterization of immune peptides in two groups of medically important insects, the mosquitoes and blackflies, is currently an important research area. Mosquitoes transmit a variety of viral and parasitic diseases including yellow fever, dengue, malaria and lymphatic filariasis. Simuliid black flies are vectors of river blindness. The diseases are together responsible for death and morbidity in millions of people each year. The relationship between inducible peptides and bacterial and parasitic infections in these insects is proving to be a complex one. The identification of an insect defensin (4 kDa) in Aedes aegypti, the yellow fever mosquito, has proved to be the first peptide characterized in a vector of human disease. This inducible molecule appears in the haemolymph in response to bacterial and to a lesser extent filarial infection. The characterization of inducible blackfly peptides has revealed potent inducible anti-Gram-positive as well as anti-Gram-negative activity. In addition, non-self recognition molecules such as phenoloxidase may play a part in differentiating one species of eukaryotic pathogen from another of the same genus. The interactions between the peptides and these other proteins are likely to be important in the establishment of a successful immune response against a parasitic pathogen, particularly as we now know these peptides to have anti-eukaryotic activity (against a range of parasite species). As well as being of fundamental interest in our understanding of host-parasite relationships, the indication that antibacterial peptides are toxic to parasitic organisms has implications for their possible use in the disease vector control strategies of the future. It may also mean that a revision in our understanding of their mode of action, loose as it is, has to take place.
 ...
PMID:Antibacterial peptides in insect vectors of tropical parasitic disease. 776 49

Onchocerciasis is commonly known as River Blindness and affects about 18 million people around the world. It is transmitted by black flies that breed in river and stream rapids and transmit the parasitic microfilariae, Onchocerca volvulus, to people who live and work near such rivers. Infection with the microfilariae results in blindness or visual impairment for 1 or 2 million people. The microfilariae migrate to superficial tissues and may invade any part of the eye and ocular structure. Living worms cause little damage, however, their death triggers a localized inflammation which can lead to blindness. Sclerosing keratitis, a severe corneal involvement, is the major cause of blindness from the disease. The World Health Organization (WHO) Expert Committee on Onchocerciasis has estimated that 9% of the disease is found in Africa, the rest occur in Yemen and Latin America. Treatment with ivermectin is contraindicated for pregnant and lactating women, children under 5 years of age, asthmatics, and people with other diseases. The WHO Onchocerciasis Control Program in 11 countries of West Africa has eliminated the risk of onchocerciasis by aerial spraying of black fly breeding sites only from 1 country. A single annual oral dose (150 mg/kg) of ivermectin can reverse early lesions in the cornea. Ivermectin must be taken annually to sustain protection against blindness, thus its incorporation into primary health care along with malaria, AIDS, trachoma, xerophthalmia, and cataract is most cost effective. Nigeria and Tanzania have optometry schools, and optometrists can play a significant role in onchocerciasis control and blindness prevention programs by training local health care workers to distribute invermectin in vision screening programs.
 ...
PMID:Onchocerciasis and other eye problems in developing countries: a challenge for optometrists. 824 90

Globally, there have been improvements in the world's health, but in many countries the infant mortality rate is rising. Widespread disease is present in many developing countries. 250 million people suffer from filariasis and 30 million more have onchocerciasis or river blindness. 200 million are infected with schistosomiasis and each year 150 million new cases of malaria are registered. Over 5 million children die from diarrheal diseases in developing countries. Many health experts now believe that there is a way to rectify this situation by transforming the medical technostructure. The challenge for the "Health for All" movement is to find a health service that people can afford and in which people can play a major role. Community participation is an important part of this movement. Lower costs for health care, better distribution of funds for health, and more equitable distribution of resources are necessary. The concept of "Health for All" challenges the prevailing concept of development in which human communities are considered passive.
 ...
PMID:A call for justice. 1226 52

In 1964, at independence, Zambia's economic future looked brighter than that of most other developing countries. Its copper production accounted for 8% of total world production, and only neighboring Zaire outpaced it in the production of cobalt. Its Central Province around Kabwe held rich deposits of both zinc and lead; uranium deposits also had been found, but their projected yield remained undetermined. Since 1974, the decline in the price of copper and the increase in the price of oil have played havoc with Zambia's balance of payments. Copper, which accounted for 40% of the gross national product (GNP) and 98% of all foreign exchange in 1964, shrank to 12% of the GNP in 1978 while still generating most of the foreign exchange. As a result, imports were cut back markedly from $1.5 billion in 1973 to $690 million in 1983. Although this trend is beginning to make a U-turn, Zambia's economic situation is grave. In 1984 the GNP continued to register negative growth and inflation stood at 25%. With its urbanization rate doubling from 21% in 1964 to 43% in 1985, Zambia is now the most urbanized country south of the Sahara. Zambia's 1985 population is estimated to be 6.8 million. Between 1963 and 1969, the average annual population growth rate was 2.5: it was 3.1% between 1969-80. The current birthrate of about 48/1000 is expected to decline only marginally in the next 15 years, but the death rate is declining more rapidly -- from 19/1000 in the late 1960s to 15/1000 in 1985. Life expectancy is expected to rise from the current 51 years to about 58 years. As a result of the high growth rate, Zambia's population is young, with a median age of about 16.3 years. Traditional African values stress the importance of large families. Zambia's total fertility rate was 6.9 in 1985. According to the World Bank, only 1% of married women of childbearing age in 1982 used contraceptives. Although tribal links are weakening, Zambia still counts 73 officially recognized tribes. Together, they speak about 40 different dialects. Zambia now apportions over 15% of its national budget to education. Despite some noticeable progress, the public health structure remains deficient. Principal health problems include malaria, tuberculosis, and, in Northern Province and Luapula Province, sleeping sickness and river blindness. About 2/3 of the labor force, an estimated 2.2 million persons in 1982, still work in agriculture. Female labor force participation is lower in Zambia than in many African nations.
 ...
PMID:The Republic of Zambia. 1226 4

Insects transmit the causative agents for such debilitating diseases as malaria, lymphatic filariases, sleeping sickness, Chagas' disease, leishmaniasis, river blindness, Dengue, and yellow fever. The persistence of these diseases provides testimony to the genetic capacity of parasites to evolve strategies that ensure their successful development in two genetically diverse host species: insects and mammals. Current efforts to address the problems posed by insect-borne diseases benefit from a growing understanding of insect and mammalian immunity. Of considerable interest are recent genomic investigations that show several similarities in the innate immune effector responses and associated regulatory mechanisms manifested by insects and mammals. One notable exception, however, is the nearly universal presence of a brown-black pigment accompanying cellular innate immunity in insects. This response, which is unique to arthropods and certain other invertebrates, has focused attention on the elements involved in pigment synthesis as causing or contributing to the death of the parasite, and has even prompted speculation that the enzyme cascade mediating melanogenesis constitutes an ill-defined recognition mechanism. Experimental evidence defining the role of melanin and its precursors in insect innate immunity is severely lacking. A great deal of what is known about melanogenesis comes from studies of the process occurring in mammalian systems, where the pigment is synthesized by such diverse cells as those comprising portions of the skin, hair, inner ear, brain, and retinal epithelium. Fortunately, many of the components in the metabolic pathways leading to the formation of melanin have been found to be common to both insects and mammals. This review examines some of the factors that influence enzyme-mediated melanogenic responses, and how these responses likely contribute to blood cell-mediated, target-specific cytotoxicity in immune challenged insects.
 ...
PMID:Melanogenesis and associated cytotoxic reactions: applications to insect innate immunity. 1580 78

The control of river blindness (onchocerciasis) has been one of the major public health achievements of recent decades. Initially, vector control was used to stop transmission of the parasite Onchocerca volvulus by blackflies (Simulium) but the introduction of ivermectin (Mectizan) as a means of morbidity control enabled new strategies of distribution to be developed based on community directed treatment. The donation of Mectizan by Merck & Co. Inc. for onchocerciasis control in 1987 'as long as needed' was a public health landmark to be followed by a donation from GlaxoSmithKline of albendazole in 1997 for lymphatic filariasis to which Merck also responded by agreeing to extend their donation to include the coadministration of Mectizan and albendazole. Both the drugs, however, have wider impacts than those specific to filarial parasites and are effective against a range of intestinal parasites, whilst ivermectin has an important effect on ectoparasites. The wider benefits of the annual public health intervention-collateral benefits--therefore include deworming, improved nutritional status, increased growth, improved school performance and attendance, and improved haemoglobin status as a result of the impact of albendazole on hookworm, a major cause of anaemia. More recently, studies suggest that worm-free children have a significantly reduced frequency of malaria specific episodes of fever and Ascaris-infected children have a two-fold higher frequency of cerebral or severe malaria than those without Ascaris. These findings suggest that programmes based on annual interventions to control river blindness and lymphatic filariasis can contribute disproportionately more to a range of public health problems than has been hitherto recognized, thereby assisting in attaining the millennium development goal targets.
 ...
PMID:Public-private partnerships in blindness prevention: reaching beyond the eye. 1630 84

Many infectious diseases of global impact are caused by parasites. This includes diseases with protozoan etiology, such as malaria, African sleeping sickness, Chagas disease, toxoplasmosis, and amoebiasis, as well as diseases caused by metazoa, such as river blindness, schistosomiasis, ecchinococcosis, and ascariasis. Combined, parasitic diseases affect more than half the world's human population and are responsible for decreased gross national products and billions of dollars in lost earnings. Although the magnitude of the problem precludes quick solutions, there is reasonable hope that a better understanding of these organisms, especially the host-parasite interactions that underpin virulence and pathogenicity mechanisms, will provide new opportunities for rational intervention strategies. Yeast artificial chromosomes (YAC) have substantially aided in this endeavor by providing an unlimited access to defined parts of a parasite's genome, which, in turn, has facilitated a broad range of molecular studies. For example, YACs have facilitated positional cloning strategies to identify genes involved in antigenic variation and drug resistance mechanisms. Moreover, YACs have been invaluable tools for the many genome sequencing projects examining parasites. In this chapter, we provide a detailed protocol of how to generate representative YAC libraries from parasite genomes. This protocol can be applied to both protozoa and metazoa, and can even be used for YAC library construction of parasite material isolated from a single infected host.
 ...
PMID:Construction of yeast artificial chromosome libraries from pathogens and nonmodel organisms. 1707 69

Parasite infections in the central nervous system (CNS) are a major cause of morbidity and mortality worldwide, second only to HIV infection. Finding appropriate therapeutic measures to control CNS parasite infections requires an understanding of the tissue-specific host response. CNS parasitic diseases are invariably associated with persistent T-helper 1 (Th1) cytokine-dependent proinflammatory responses. Although type 1 cytokine-dependent proinflammatory responses are essential to control several types of parasite infections, their persistent production contributes to the development of neuropathology with severe consequences. A family of proteins called Toll-like receptors (TLRs) plays a pivotal role in the induction of inflammatory cytokines during infections and tissue injury. Accumulating evidence indicates that in several CNS parasitic infections such as toxoplasmosis and sleeping sickness, host responses mediated through TLRs contribute to parasite clearance and host survival. However, TLR-mediated responses can also contribute to disease severity, as exemplified in cerebral malaria, neurocysticercosis and river blindness. Thus, TLRs influence the immunopathogenesis of CNS parasitic infections by mechanisms that can either benefit the host or further contribute to CNS pathology. This chapter discusses the immunopathogenesis of parasitic infections in the CNS and the role of TLRs in this process.
 ...
PMID:Toll-like receptors in CNS parasitic infections. 1968 29

In 2000, 189 member states of the United Nations (UN) developed a plan for peace and development, which resulted in eight actionable goals known as the Millennium Development Goals (MDGs). Since their inception, the MDGs have been considered the international standard for measuring development progress and have provided a blueprint for global health policy and programming. However, emphasis upon the achievement of priority benchmarks around the "big three" diseases--namely HIV, tuberculosis (TB), and malaria--has influenced global health entities to disproportionately allocate resources. Meanwhile, several tropical diseases that almost exclusively impact the poorest of the poor continue to be neglected, despite the existence of cost-effective and feasible methods of control or elimination. One such Neglected Tropical Disease (NTD), onchocerciasis, more commonly known as river blindness, is a debilitating and stigmatizing disease primarily affecting individuals living in remote and impoverished areas. Onchocerciasis control is considered to be one of the most successful and cost-effective public health campaigns ever launched. In addition to improving the health and well-being of millions of individuals, these programs also lead to improvements in education, agricultural production, and economic development in affected communities. Perhaps most pertinent to the global health community, though, is the demonstrated effectiveness of facilitating community engagement by allowing communities considerable ownership with regard to drug delivery. This paper reviews the contributions that such concentrated efforts to control and eliminate onchocerciasis make to achieving select MDGs. The authors hope to draw the attention of public policymakers and global health funders to the importance of the struggle against onchocerciasis as a model for community-directed interventions to advance health and development, and to advocate for NTDs inclusion in the post 2015 agenda.
 ...
PMID:The Contributions of Onchocerciasis Control and Elimination Programs toward the Achievement of the Millennium Development Goals. 2599 46


1 2 Next >>