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)

Cytoplasmic polyribosomes were isolated from the avian malaria parasite Plasmodium lophurae by lysis with 0.15% Triton X-100 followed by high speed centrifugation through a discontinuous sucrose gradient. Polyribosomes were protected from nuclease degradation using 100 mug/ml heparin or 50 mug/ml dextran sulfate. Cell-free incorporation of radioisotope-labeled amino acids required a pH 5 fraction (duck reticulocyte), Mg2+, and an energy-generating system. The protein synthesizing system was stimulated by the addition of polyuridylic acid. Optimum conditions for protein synthesis by the plasmodial system are described. The effects of drugs on the cell-free protein synthesizing system using duck reticulocyte and plasmodial ribosomes are reported.
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PMID:Protein synthesis by a cell-free preparation from the bird malaria, Plasmodium lophurae. 0 95

Radioisotope red-cell survival studies were carried out in 20 patients with falciparum malaria following quinine therapy. The mean parasite clearance time of the patients receiving quinine sulfate was 49 hours and those of the patients receiving quinine sulfate and prednisolone was 46 hours. The red-cell survival was correlated with the initial hematocrit level in both groups but the daily dose of 40 mg prednisolone did not mitigate the red cell survival.
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PMID:The effect of prednisolone on red cell survival in patients with falciparum malaria. 38 43

Chloroquine is considered essentially nontoxic when used for the chemosuppression of malaria, but gastrointestinal upsets, headache, blurring of vision, pruritus, and uritcaria may occur during chloroquine therapy. Recently, Bhargava et al. and Eronini and Eronini have reported the extrapyramidal syndrome (EPS) following chloroquine therapy in adults. The clinical manifestations included upward rolling of the eyeballs, retraction of neck and back, trismus with marked difficulty in speech, and coarse tremors. Observations of 4 instances of EPS in children following chloroquine therapy for malaria are reported. A 2-1/2 year old girl was admitted to the All India Institute of Medical Sciences Hospital with a 4 day history of intermittent high grade pyrexia with chills and rigors. Following treatment with oral chloroquine in the recommended therapeutic dosage, the fever responded, but the child became drowsy and developed paroxysms of involuntary movements of the tongue, torticollis, torsion dystonia of the limbs, and parosysms of tonic muscular spasms. She completely recovered spontaneously within 48 hours. The 2nd case was that of a 12-year old female brought to the hospital with a 15-day history of intermittent high grade fever with chills and rigors. The patient was started on chloroquine sulfate in the recommended therapeutic dose. After an interval of 4 days she developed coarse tremors of the hands, upward rolling of the eyeballs, episodic deviation of the angle of the mouth towards the left, and trismus. These symptoms disappeared spontaneously within 8 hours. A 6-year old girl, the 3rd case, developed episodes of opisthotonous, upward rolling of the eyeballs, protrusions of the tongue, intermittent writhing movements of the upper limbs, and drowsiness following the ingestion of 6 tablets of chloroquine sulfate for suspected diagnosis of malaria. She spontaneously recovered from EPS over a period of about 48 hours. The 4th case, a 7-year old boy, gave a history of high grade fever with chills and rigors of 1 day's duration. He developed drowsiness, tonic spasms of the neck, upward rolling of the eyeballs, and writhing contortions of all limbs about 2 hours following intravenous administration of 100 mg of chloroquine. 8 hours later an additional 100 mg chloroquine was given intravenously for the mistaken diagnosis of cerebral malaria. On examination the child was drowsy, had generalized stiffness, torticollis, and trismus. He recovered gradually over a 48-hour period without any specific therapy. The exact mechanism of production of EPS remains uncertain.
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PMID:Extrapyramidal syndrome following chloroquine therapy. 45 22

Imported malaria has been increasing in the United States. Locally acquired cases are reported in drug addicts. Extended incubation periods can be misleading. Pyrexia is the most common manifestation, but it may not follow a regular pattern. A high index of suspicion and examination of peripheral blood smears establish the diagnosis. Chloroquine and primaquine are the drugs of choice for uncomplicated malaria; quinine sulfate is preferred in the treatment of chloroquine-resistant malaria. Malarial prophylaxis should include travelers' education and chemoprophylactic agents such as chloroquine, chloroguanide, pyrimethamine and amodiaquine.
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PMID:Malaria--a red alert. 46 29

The duration of action of the drug Antemal, a combination of Pyrimethamine and Sulfametopyrazine, was eveluated in Bobo-Dioulasso, Upper Volta, West Africa, and endemic zone for Plasmodium falciparum malaria. The study was held during the season of maximum malaria transmission. 79 persons presenting with an acute attack of malaria were studied; 37 persons received a single dose of chloroquine sulfate (Nivaquine), at a dose of 15 mg./kg.; 42 persons received a single dose of Antemal at a dose of one tablet (75 mg. of Pyrimethamine and 25 mg. of Sulfametopyrazine) per 10 kg. Clinical and parasitological studies of all subjects occurred on days one, two, three, 10, 17, 24 and 31. Only one of 37 (2.7%) subjects on Antemal had a reappearance of trophozoites, occurring on day 17. Eight of 42 (19.0%) patients taking nivaquine had reappearance of trophozoites, observed between day 23 and 31. Gametocytes were observed in eight of 37 (21.6 %) persons on Antemal and in only one of 42 (2.3 %) persons on Nivaquine. These observations suggest an extended duration of protection from Antemal in semi-immune individuals. Nivaquine appeared as a potent inhibitor of gametocytogenesis.
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PMID:[Duration of action of the pyrimethamine-sulfametopyrazine combination in a Plasmodium falciparum endemic zone]. 110 Feb 87

Making use of a model pair Aedes aegypti--Plasmodium gallinaceum, the authors assess the susceptibility of mosquito female survivors to malaria agent after treatment of larvae with various bioactive substances. Eight binary combinations of 6 preparations have been tried: dimilin and uvemon, insect development regulators; fundosol and copper sulfate, fungicides; phytobacteriomicin (PBM), a larvicidal antibiotic; bactoculicide, a bacterial agent. Combinations of PBM with compounds differing by their mechanisms of action were found to inhibit the specific effect of PBM on the vector, PBM specific effect consisting in depression of mosquito susceptibility to P. gallinaceum. PBM combinations with some agents may alter other parameters of the vector potential: combinations of copper sulfate or uvemon with low concentrations of PBM potentiated the larvicidal effect, and PBM mixtures with fungicides reduces the activity of female attacks.
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PMID:[The susceptibility of mosquitoes for Plasmodium gallinaceum in the joint use of biologically active substances]. 143 76

Region II of the malaria circumsporozoite (CS) protein is highly conserved between the CS proteins of different species of malaria. Amino acid sequences homologous to that of region II are found in thrombospondin, properdin, von Willebrand factor and a few other proteins. We show here that the native CS protein from the rodent parasite Plasmodium berghei, and recombinant Plasmodium vivax and Plasmodium falciparum CS proteins containing region II, but not recombinant proteins lacking region II, specifically bind to sulfatides and cholesterol-3-sulfate. The binding is abolished following reduction and alkylation of the proteins. Region II contains 2 cysteines separated by only 3 amino acids, S(N), V, T, and these are the only cysteines present in our recombinant proteins. Therefore, our findings strongly suggest that the region II cysteines are linked by a disulfide bond forming a small peptide loop. We also present evidence that the recognition of sulfatides, cholesterol-3-sulfate, or other cross-reactive sulfated macromolecules by region II may be required during sporozoite invasion of liver cells. Antibodies to a peptide representing region II react with live sporozoites and with sporozoites fixed with glutaraldehyde, indicating that this region is exposed on the surface of the parasites. Furthermore, we have found that the sulfatide and cholesterol-3-sulfate recognition by the CS proteins, and the invasion of hepatocytes by P. berghei sporozoites, are specifically inhibited by dextran sulfate.
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PMID:Binding of malarial circumsporozoite protein to sulfatides [Gal(3-SO4)beta 1-Cer] and cholesterol-3-sulfate and its dependence on disulfide bond formation between cysteines in region II. 151 21

To determine the effect of chloroquine chemoprophylaxis during pregnancy on birth weights, a randomized trial was carried out in 1987 and 1988 in Banfora, Burkina Faso (West Africa). Seven hundred forty-five randomly selected women treated with chloroquine sulfate were compared to with 719 controls who received no treatment. In spite of an unquestionable effect of chloroquine in preventing placental infection (4.1% infected placentas in the treated group versus 19.0% in the controls), the mean difference in birth weights between the two groups (6 g) was not significant. The difference in the proportion of low birth weight (LBW) newborn babies in two groups (16.3% versus 16.4%) was also not significant. However, there was a strong relationship between placental infection and birth weight (the mean birth weight difference between infected and uninfected placentas was 113 g, and the proportion of LBW babies was 26.0% in infected placentas versus 14.8% in uninfected placentas). The small difference in birth weights observed between the two groups may be due to the fact that the prevalence rate of placental infection is low and that prophylaxis is effective only on a portion of the subjects in the treated group. It may also indicate that malaria is only one of several risk factors responsible for LBW. The relatively small increase in birth weight, the expected poor acceptance of mass prophylaxis, and the spreading of chloroquine-resistant Plasmodium strains should be considered before extending malaria chemoprophylaxis to all pregnant women. It might be worth considering to limit prophylaxis to primigravidae.
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PMID:Effect of chloroquine chemoprophylaxis during pregnancy on birth weight: results of a randomized trial. 153 79

Circumsporozoite (CS) proteins, which densely coat malaria (Plasmodia) sporozoites, contain an amino acid sequence that is homologous to segments in other proteins which bind specifically to sulfated glycoconjugates. The presence of this homology suggests that sporozoites and CS proteins may also bind sulfated glycoconjugates. To test this hypothesis, recombinant P. yoelii CS protein was examined for binding to sulfated glycoconjugate-Sepharoses. CS protein bound avidly to heparin-, fucoidan-, and dextran sulfate-Sepharose, but bound comparatively poorly to chondroitin sulfate A- or C-Sepharose. CS protein also bound with significantly lower affinity to a heparan sulfate biosynthesis-deficient mutant cell line compared with the wild-type line, consistent with the possibility that the protein also binds to sulfated glycoconjugates on the surfaces of cells. This possibility is consistent with the observation that CS protein binding to hepatocytes, cells invaded by sporozoites during the primary stage of malaria infection, was inhibited by fucoidan, pentosan polysulfate, and heparin. The effects of sulfated glycoconjugates on sporozoite infectivity were also determined. P. berghei sporozoites bound specifically to sulfatide (galactosyl[3-sulfate]beta 1-1ceramide), but not to comparable levels of cholesterol-3-sulfate, or several examples of neutral glycosphingolipids, gangliosides, or phospholipids. Sporozoite invasion into hepatocytes was inhibited by fucoidan, heparin, and dextran sulfate, paralleling the observed binding of CS protein to the corresponding Sepharose derivatives. These sulfated glycoconjugates blocked invasion by inhibiting an event occurring within 3 h of combining sporozoites and hepatocytes. Sporozoite infectivity in mice was significantly inhibited by dextran sulfate 500,000 and fucoidan. Taken together, these data indicate that CS proteins bind selectively to certain sulfated glycoconjugates, that sporozoite infectivity can be inhibited by such compounds, and that invasion of host hepatocytes by sporozoites may involve interactions with these types of compounds.
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PMID:Malaria sporozoites and circumsporozoite proteins bind specifically to sulfated glycoconjugates. 160 93

Dihydroorotate dehydrogenase (DHODase) has been purified 400-fold from the rodent malaria parasite Plasmodium berghei to apparent homogeneity by Triton X-100 solubilization followed by anion-exchange, Cibacron Blue F3GA-agarose affinity, and gel filtration chromatography. The purified enzyme has a molecular mass of 52 +/- 2 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and of 55 +/- 6 kDa by gel filtration chromatography, and it has a pI of 8.2. It is active in monomeric form, contains 2.022 mol of iron and 1.602 acid-labile sulfurs per mole of enzyme, and does not contain a flavin cofactor. The purified DHODase exhibits optimal activity at pH 8.0 in the presence of the ubiquinone coenzyme CoQ6, CoQ7, CoQ9, or CoQ10. The Km values for L-DHO and CoQ6 are 7.9 +/- 2.5 microM and 21.6 +/- 5.5 microM, respectively. The kcat values for both substrates are 11.44 min-1 and 11.70 min-1, respectively. The reaction product orotate and an orotate analogue, 5-fluoroorotate, are competitive inhibitors of the enzyme-catalyzed reaction with Ki values of 30.5 microM and 34.9 microM, respectively. The requirement of the long-chain ubiquinones for activity supports the hypothesis of the linkage of pyrimidine biosynthesis to the electron transport system and oxygen utilization in malaria by DHODase via ubiquinones [Gutteridge, W. E., Dave, D., & Richards, W. H. G. (1979) Biochim. Biophys. Acta 582, 390-401].
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PMID:Purification and characterization of dihydroorotate dehydrogenase from the rodent malaria parasite Plasmodium berghei. 184 78


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