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

Rhesus monkeys were immunized with a preparation of Plasmodium knowlesi parasites containing principally microgametes with lesser numbers of macrogametes and asexual trophozoites. The antigen mixture was emulsified in Freund's complete adjuvant (FCA) and administered intramuscularly. After one or two inoculations of from 10(5) to 10(7) microgametes in FCA, monkeys showed high levels of circulating anti-gamete antibodies as demonstrated by various in vitro microgamete immobilization or transmission blocking tests. After challenge with P. knowlesi, immunized monkeys developed low level asexual parasitemias and were not infectious to feeding mosquitoes as measured by growth of the parasite on the mosquito gut. Control monkeys developed rapidly rising, usually fatal infections and were highly infectious to mosquitoes. Anti-gamete antibodies appear to neutralize the sexual parasites and prevent mosquito infection within the gut of the recently fed mosquito vector. Suppression of asexual parasitemia in immunized monkeys may be due to the presence of asexual trophozoites in the antigen mixture or to antigens common to both sexual and asexual stages of the parasite. A vaccine effective as a single injection capable of interrupting malaria transmission from man to man whereas reducing the severity of the disease in infected individuals offers a new approach to the control of one of the major diseases affecting man.
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PMID:Malaria immunization in Rhesus monkeys. A vaccine effective against both the sexual and asexual stages of Plasmodium knowlesi. 10 24

Gametocyte infectivity and oocyst development of the avian malaria parasite, Plasmodium gallinaceum, can be reduced or eliminated in mosquitoes by immunizing the chickens on which the mosquitoes feed with infected red blood cells that have been treated with formalin or x-rays. Protection of the mosquito appears to be related to the immobilization of the microgametes in its gut and is associated with the immunoglobulin G fraction of serum.
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PMID:Successful immunization against the sexual stages of Plasmodium gallinaceum. 95 32

A relationship was found between Pseudomonas suppression by phytobacteriomycin (PBM) in the mosquito larval gut and the mosquito vectorial capacity. The suppression of Pseudomonas bacteria in larvae caused a decrease in the vectorial capacity of emerged imagines. The results of the in vivo tests were verified in vitro with the culture of bacteria isolated from mosquito larva in liquid medium with pH 8.4 which is equal to intestinal pH of Ae. aegypti larva inside the peritrophic membrane. The laboratory Ae. aegypti fed on sugar with PBM addition (titer 100 U/ml) were 18.9% lees sensitive to malaria parasite. Without additional blood meal, mosquito sensitivity to malaria parasite sharply decreases at day 14, without substantially changing their intestinal microflora.
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PMID:[The relation between changes in the intestinal microflora of mosquito larvae under the action of phytobacteriomycin and female susceptibility to the causative agent of malaria]. 133 32

Reactivation of latent infection is the principal mechanism relating Toxoplasma gondii and Pneumocystis carinii to HIV. Less common is reactivation in Leishmania donovani, Trypanosoma cruzi, and microsporidian infections. An impaired primary immune response occurs in all these infections, and also with Cryptosporidium and Isospora belli. Association of HIV infection with gut parasites including Giardia lamblia and Entamoeba histolytica, and also with Trichomonas vaginalis infection is likely to be related to sexual modes of contact that favour both HIV and the parasite. The severity of malaria is not definitely associated with HIV, but Plasmodium falciparum infection may favour more rapid evolution of the HIV infection. Both malaria and trichomoniasis favour HIV transmission; the former by necessitating blood transfusion, and the latter by enhancing viral transmission during sexual contact.
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PMID:Protozoan infections and HIV-1 infection: a review. 139 92

The infection of mosquitoes with malaria plasmodia was found to be affected by relative (to full portion) blood amount of the infected donor, which they suck out, i.e. to what extent the engorged portion approximates to the limiting one when mosquitoes cease bloodsucking. The facts obtained show that the survival of plasmodia in a mosquito (most likely, the passing of ookinetes into the outer side of the mid-gut) is associated with the degree of its stretching during bloodsucking. The limit stretching may be also attained during feeding up on a healthy donor.
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PMID:[The relationship between the amount of blood that mosquitoes engorge and their infectivity with the causative agent of malaria]. 209 99

Circulating antigen in sera from acute, chronic and late stages of schistosomiasis patients was detected by direct dot-ELISA with monoclonal antibody 3D8A against schistosome gut-associated cathodic antigen linked with peroxidase, the positive rates being 90.6%, 83.2% and 30.7%, respectively. No positive reactions were found with sera from patients of clonorchiasis, malaria and non-parasitic diseases. The positive rate and the circulating antigen level in EPG greater than 100 group of patients were found to be higher than those in EPG less than 100 group. Circulating antigen became negative one year after praziquantel treatment in 84.0% of patients who showed negative fecal examination, while the other patients remained positive with decreasing titers. The results indicated that the circulating antigen in sera from schistosomiasis patients of various stages can be detected by dot-ELISA with monoclonal antibody 3D8A against circulating schistosome gut-associated cathodic antigen. The authors concluded that the circulating antigen level was correlated with the intensity of infection and the efficacy of treatment.
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PMID:[Detection of circulating antigen in schistosomiasis by dot-ELISA with monoclonal antibody]. 212 22

Density patterns of 17 species of anopheline mosquitoes collected between 1980 and 1981 from indoor and outdoor resting places of a highly malarious area of Bastar district, Madhya Pradesh are given. A. culicifacies and A. fluviatilis are the important vector species in the region. The former was highly endophilic and found throughout the year and its man hour density (MHD) ranged from 7.6 to 78 with peaks in February and July. The latter was highly exophilic, also found throughout the year. Its density ranged from 1.6 to 7.0 per 10 man hours with a peak in July/August. A. subpictus was considered as potential vector species, found throughout the year and was endophilic, having MHD ranging from 0.9 to 148 with peaks in February-March and July-August. The MHD variations of other species were; A. aconitus (0.02-1.04), A. annularis (0.02-10.4), A. barbirostris (0.04-1.07), A. hyrcanus (1.30-1.86), A. jamesii (0.01-0.46), A. jeyporiensis (0.01-1.06), A. karwari (0.01-0.04), A. maculatus (0.01-0.03), A. pallidus (0.02-2.4), A. splendidus (0.02-0.32), A. tessellatus (0.02-0.12), A. theobaldi (0.01-0.03), A. vagus (0.01-2.3) and A. varuna (0.03-0.31). Results of gut and gland dissections showed correlation of infection with the occurrence of peak vector densities. The density levels and seasonal activities of vectors as well as potential vector species are favourable for perennial transmission of malaria in Bastar district.
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PMID:Density patterns of anophelines and their relation to malaria in Bastar district, Madhya Pradesh. 229 24

Malarial gametocytes, which are taken up by mosquitoes during a blood meal, develop in the gut of the mosquito into gametes. Gametes and gametocytes contain the target antigens of transmission-blocking immunity. Here, we show that the peripheral blood of nonexposed donors contains Plasmodium falciparum gamete-reactive T cells at frequencies ranging from 1/300 to 1/4000. Studies on long-term clones demonstrated that these cells often recognized antigens shared between gametes and asexual stage parasites or even between heterologous gametes, although it has been possible to derive a P. falciparum gamete-specific T clone. The T clones examined were T3+, T4+, T8-, and either HLA-DR- or HLA-DQ-restricted. They responded to gametes by both proliferation and the secretion of gamma-interferon. The gamete-specific clone and other asexual cross-reactive clones examined could be stimulated in vitro by a preparation of mature gametocytes within RBC, but not by RBC alone, suggesting that gametocytes are immunogenic or can become immunogenic for T cells in vivo. The significance of these observations to mosquito transmission of malaria and development and application of a gamete vaccine are discussed.
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PMID:Human T clones reactive to the sexual stages of Plasmodium falciparum malaria. High frequency of gamete-reactive T cells in peripheral blood from nonexposed donors. 243 Oct 58

A sensitive ELISA was developed to monitor the persistence of a specific antibody, rabbit anti-BSA, in the bloodmeal, haemolymph and tissues of the mosquito Anopheles stephensi Liston. Different concentrations of anti-BSA were fed to female mosquitoes in sheep blood, via a membrane-feeder, and it was found that antibody persisted in the gut as the bloodmeal was digested: concentrations present at 24 h were directly related to those fed. Homogenates of mosquito bodies, from which the intact guts had been removed, were always antibody-positive up to 9 days post-feeding, indicating that undigested antibody had passed through the gut wall into the haemocoele. Haemolymph was extracted from mosquitoes at different times post-feeding, using a microcapillary and manipulator, and antibody was detected in several of the assays. The level of antibodies in the haemolymph 24 h post-feeding was less than half of the level in mosquito heads, indicating removal of antibodies from the haemolymph, perhaps by binding onto haemocoelic tissues. The relevance of these results to the ingestion, survival and fate of antibody against malaria sporozoites is discussed.
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PMID:Uptake and persistence of ingested antibody in the mosquito Anopheles stephensi. 251 68

Gametocytocidal activity of artemisinin (qinghaosu) has been demonstrated against simian malaria parasite Plasmodium cynomolgi B. Colony-bred Anopheles stephensi were allowed to feed on gametocyte-carrying rhesus monkeys and the mosquito infectivity rate and oocyst count of the infected mosquito gut were recorded on day 8-9 postinfection. Control (pretreatment) feedings of mosquito on gametocyte-carrying monkeys showed good infectivity in different batches of the mosquitoes ranging from 57.14 to 95.0%. Administration of single intramuscular injection of 5 mg/kg artemisinin (suspended in neutralised oil) resulted in complete loss of mosquito infectivity within 24 h of drug administration. This is the first report on the possible use of artemisinin to stop malaria transmission. The drug has no sporontocidal action.
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PMID:Artemisinin (qinghaosu)--a new gametocytocidal drug for malaria. 276 60


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