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)

The protective association between the human leukocyte antigen HLA-B53 and severe malaria was investigated by sequencing of peptides eluted from this molecule followed by screening of candidate epitopes from pre-erythrocytic-stage antigens of Plasmodium falciparum in biochemical and cellular assays. Among malaria-immune Africans, HLA-B53-restricted cytotoxic T lymphocytes recognized a conserved nonamer peptide from liver-stage-specific antigen-1 (LSA-1), but no HLA-B53-restricted epitopes were identified in other antigens. These findings indicate a possible molecular basis for this HLA-disease association and support the candidacy of liver-stage-specific antigen-1 as a malaria vaccine component.
Nature 1992 Dec 03
PMID:Molecular analysis of the association of HLA-B53 and resistance to severe malaria. 136 Jan 49

To determine the nature and extent of variation in the T cell sites of the Plasmodium falciparum circumsporozoite (CS) protein, a candidate antigen in the development of a malaria vaccine, we cloned and sequenced 69 recombinant clones of the CS protein gene representing 18 and 17 P. falciparum isolates from infected individuals from Madang, Papua New Guinea (PNG), a holoendemic malaria region, and Paragaminos and Jacunda, Brazil, relatively low endemic regions, respectively. As previously known, the amino acid sequence polymorphism was restricted to the three immunodominant regions of the protein, Th1R-N1, Th2R, and Th3R. While some of the observed nonsilent mutations in the T cell determinants of the CS protein were similar to those previously identified, we have found new amino acid changes in each of the polymorphic sequences in parasites from PNG and Brazil. A comparison of the CS epitope sequences of parasites from PNG and Brazil with the previously known CS epitope sequences of parasites from Brazil and The Gambia showed the following: 1) polymorphism was found in the Th1R-N1, Th2R, and Th3R region; however, while amino acid substitutions in the Th1R-N1 and Th2R region tended to be conservative, the substitutions found in the Th3R region were not, suggesting that the Th3R epitope may be rapidly evolving to allow parasites to escape host antiparasite cytotoxic T cell-enforced immune responses, and 2) the CS proteins of P. falciparum from high malaria-transmission regions (PNG and The Gambia) appear more polymorphic than the CS proteins of parasites from relatively low malaria-endemic regions in Brazil, where P. falciparum infection has been recently established.
Am J Trop Med Hyg 1992 Dec
PMID:Diversity in the immunodominant determinants of the circumsporozoite protein of Plasmodium falciparum parasites from malaria-endemic regions of Papua New Guinea and Brazil. 128 68

It takes a number of years to develop clinical immunity to malaria and malaria pathology is also most evident a number of years after birth. T cells are known to play an important role in defence from malaria parasites but may also contribute to the disease symptoms associated with malaria. T cells which react against malaria parasites have arisen through stimulation with organisms which cross-react with malaria or through exposure to the malaria parasites themselves and express a memory phenotype (CD45Ro+, CD45Ra-, CD4+). T clones which have arisen through exposure to cross-reactive organisms may be expected to home to the tissues where initial exposure occurred as determined by tissue-specific adhesion molecules on the lymphocyte surface. Such tissues may not be appropriate to parasite killing and localization of T cells in such sites may contribute to the immunopathology of malaria. The sharp increase in immunity and decline in pathology observed in later childhood in malaria endemic areas may result from an increase in the number of T cells induced by the parasite itself (as opposed to cross-reactive organisms). Such T cells may not have a preferential trafficking to other organs and may be more likely to circulate through the spleen. Splenic changes may also allow more malaria-specific T cells to concentrate in the spleen and may facilitate interactions between T cells, monocytes, neutrophils and parasites resulting in parasite death. Whereas cytokines secreted by parasite-reactive T cells in all locations may contribute to cerebral malaria and other forms of pathology, cytokines in the spleen at least, should directly contribute to parasite death.
Immunol Cell Biol 1992 Dec
PMID:The importance of T cell homing and the spleen in reaching a balance between malaria immunity and immunopathology: the moulding of immunity by early exposure to cross-reactive organisms. 128 42

In a malaria-endemic area of Orissa, wherein chloroquine has been in use for over thirty years, 58.3% (14/24) P. falciparum cases did not respond to single dose chloroquine (10 mg base/kg) in in-vivo test. With standard dose (25 mg base/kg) 31.2% cases (10/32) showed resistance, i.e. at RI (15.6%), RII (9.4%) and RIII (6.2%) levels. Standard dose was superior in response to the single dose therapy [p < 0.05; chi 2 (df 1) = 4.11]. Out of eight isolates tested in vitro, two showed resistance to chloroquine, five to sulfadoxine/pyrimethamine (SP) but all were sensitive to amodiaquine, quinine and mefloquine. Whereas the standard dose of chloroquine would be a better option in general, in resistant cases, SP, quinine and mefloquine offer an alternative drug choice. The implications of drug resistance in a malaria-control programme and the need to revise drug policy in India are discussed.
Indian J Malariol 1992 Dec
PMID:Sensitivity status of Plasmodium falciparum to chloroquine, amodiaquine, quinine, mefloquine and sulfadoxine/pyrimethamine in a tribal population of District Sundargarh, Orissa. 129 42

Many deaths were recorded in village Baniyani of Talgram PHC of District Farrukhabad, U.P. during August to November 1991, which is the malaria transmission season in this area. Integrated measures, like one-round spraying of DDT and HCH, six-round fogging of malathion and six-time application of Baytex in mosquito breeding sites, were adopted by the Health Department of the U.P. government to avert an epidemic. Investigations carried out by the Malaria Research Centre during November and December 1991 showed low mosquito densities and larval positivity but very high incidence of malaria in the village. No malaria case was recorded by the surveillance worker of the Health Department of the state government before the outbreak of the disease. However, high slide falciparum rate (51.57), child parasite rate (40.0), infant parasite rate (66.66) and spleen rate (82.90) in the village clearly indicated hyperendemic conditions in the area and hence deaths recorded in the village during the malaria transmission period could be due to malaria only. Major factors responsible for the deaths due to malaria in the village were poor surveillance, faulty diagnosis, and low literacy and socio-economic status of the villagers.
Indian J Malariol 1992 Dec
PMID:Malaria epidemic in Baniyani village, District Farrukhabad (U.P.). 129 43

Frequency of sickle cell in Scheduled Caste and Scheduled Tribe populations was found to be 1.5 and 14.9% respectively, whereas G-6-PD deficiency was 5.9 and 4.2% respectively. Blood group B was dominant in both the communities. A significantly lower frequency of P. falciparum malaria was observed among sicklers.
Indian J Malariol 1992 Dec
PMID:Frequency of ABO blood groups, sickle-cell haemoglobin, G-6-PD deficiency and their relation with malaria in scheduled castes and scheduled tribes of Kheda District, Gujarat. 129 44

Subjects from Muria gond tribal community (n = 258) as well as from Delhi (n = 100) were classified according to ABO blood groups, and were also assayed for malarial antibodies by ELISA technique. The distribution of ABO blood groups did not differ significantly in Muria gonds and Delhi subjects. Within Muria gonds the observed frequency of ABO blood groups did not differ significantly from the expected values. No significant difference was observed in the rate of seropositivity for malarial antibodies among subjects with different blood groups. Malarial parasitaemia, although observed more in individuals with blood group A, did not differ significantly as compared with other blood groups. We conclude that ABO blood groups do not show differential susceptibility to malaria.
Indian J Malariol 1992 Dec
PMID:Malaria and ABO blood groups. 129 45

We carried out in 1989 a non randomized comparative study in French army units which had been in Central Africa (Central African Republic and Gabon) for 4 months, in order to compare in 758 men on return from malaria areas the usual strategy of chemoprophylaxis with chloroquine and a radical cure by halofantrine (Halfan). Chloroquine was taken by 278 men (100 mg daily for 6 weeks after their return to France); the other 480 men were given two doses of 1,500 mg halofantrine on the third and on the tenth day after their return to France. In Africa both of the units were on chloroquine prophylaxis (100 mg daily for 4 months). The Plasmodium falciparum attack rates were, during a period of 5 months after the return to France, 0.2% in the halofantrine group (1/480) and 4.7% (13/228) in the chloroquine group (P < 10(-4)). The radical cure by halofantrine was more effective than chloroquine prophylaxis in preventing falciparum malaria on return from malaria areas.
Ann Soc Belg Med Trop 1992 Dec
PMID:[Efficacy of radical treatment with halofantrine on the prevention of imported Plasmodium falciparum malaria]. 129 22

A sample of 120 individuals--representative of the Malawian population in terms of gender and age distribution--were interviewed regarding their perceptions of the diseases malaria and schistosomiasis. Particular attention was paid to judgements regarding the level, seriousness, predictability and controllability of these health risks. Sample sites were lowland marshland areas where both diseases were highly prevalent. Individuals were also asked about their adherence to recommended malaria and schistosomiasis control and prevention procedures. Respondents commonly rated malaria and schistosomiasis both unpredictable and uncontrollable. For malaria, no risk judgements predicted level of adherence to prevention guidelines. That is, individuals' perception of malaria risk bore no influence on whether or not they engaged in recommended behaviour. For schistosomiasis, seriousness of infection (at one sample site) and the predictability and controllability of infection (at the other sample site) predicted such adherence. Analysis of the influence of factors such as age, gender and level of education confirmed distinct patterning or responses for the two health risks. Whilst adherence to preventative guidelines for schistosomiasis is influenced by personal perceptions of risk, it appears that social factors may exert more influence on the extent of compliance with malaria control and prevention procedures. Distinct approaches to health education regarding malaria and schistosomiasis may, therefore, be warranted, with the former emphasising community responsibility and participation, and the latter individual actions which may reduce risk.
Trop Med Parasitol 1992 Dec
PMID:Perception of risk for malaria and schistosomiasis in rural Malawi. 129 27

The authors report on three cases of severe P. falciparum malaria successfully treated by iv quinine and exchange transfusion. Serum concentrations of Tumor Necrosis Factor (TNF) were determined before and during treatment. After an initial decrease, serum levels of TNF remained markedly elevated during the first 48 hours despite exchange transfusion. Though exchange transfusion accelerates the elimination of parasites from the blood, it seems to have no immediate effects on reducing serum levels of cytokines such as TNF.
Trop Med Parasitol 1992 Dec
PMID:Serum TNF in patients with severe malaria treated by exchange transfusion. 129 36


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