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)

A group of 300 young European adults visiting Gabon for relatively short periods was surveyed monthly for malaria from a parasitological, clinical, immunological, hematological point of view. The regular increase of fevers due to malaria from 1984 to 1988 and the multiplication of cases of amino-4-quinoline resistance in the plasmodial parasites call for new prophylactic considerations for this group residing in this heavily malaria infested area.
 ...
PMID:[Malaria in Gabon. Bioclinical survey of non immune Europeans during short stay and prophylactic attitude]. 267 Feb 88

Prevention and treatment of malaria are endangered by the appearance of chemoresistance against the common anti-malarial drugs by Plasmodium falciparum. Today, only a quinoline derivative, mefloquine, is a safe and effective agent against P. falciparum. An in vitro antiplasmodial activity having been found for the quassinoid glaucarubinone we tested its in vivo therapeutic action on mice infected with a P. berghei strain. At low doses, glaucarubinone retarded mortality by exerting a partial, temporary, inhibition of parasitaemia; its toxicity, however, precludes, further applications at the present time.
 ...
PMID:[Therapeutic trials of experimental murine malaria with the quassinoid, glaucarubinone]. 310 80

2-Methoxy-6-chloroacridine-9-yl- and 2-ethoxy-6-nitroacridine-9-yl-hydrazides of glycine, alpha- and beta-alanines, gamma-aminobutiric acid, epsilon-aminocaproic acid have been synthesized and their antimalarial activity has been investigated. The compounds were found to inhibit the growth of malaria parasite P. falciparum in in vitro cultures. Fifty per cent inhibitory concentrations ranged from 2 x 10(-7) to 6 x 10(-7) M and corresponded to therapeutic concentrations of known quinoline and acridine antimalarial drugs. The beta-alanine and gamma-aminobutiric acid derivatives were the most active and showed high activity against a chloroquine resistant strain of P. falciparum.
 ...
PMID:[Synthesis of acridine derivatives of amino acid hydrazines and their antimalarial activity]. 324 Mar 28

The toxicities of antimalarial drugs vary because of the differences in the chemical structures of these compounds. Quinine, the oldest antimalarial, has been used for 300 years. Of the 200 to 300 compounds synthesised since the first synthetic antimalarial, primaquine in 1926, 15 to 20 are currently used for malaria treatment, most of which are quinoline derivatives. Quinoline derivatives, particularly quinine and chloroquine, are highly toxic in overdose. The toxic effects are related to their quinidine-like actions on the heart and include circulatory arrest, cardiogenic shock, conduction disturbances and ventricular arrhythmias. Additional clinical features are obnubilation, coma, convulsions, respiratory depression. Blindness is a frequent complication in quinine overdose. Hypokalaemia is consistently present, although apparently self-correcting, in severe chloroquine poisoning and is a good index of severity. Recent toxicokinetic studies of quinine and chloroquine showed good correlations between dose ingested, serum concentrations and clinical features, and confirmed the inefficacy of haemodialysis, haemoperfusion and peritoneal dialysis for enhancing drug removal. The other quinoline derivatives appear to be less toxic. Amodiaquine may induce side effects such as gastrointestinal symptoms, agranulocytosis and hepatitis. The main feature of primaquine overdose is methaemoglobinaemia. No cases of mefloquine and piperaquine overdose have been reported. Overdose with quinacrine, an acridine derivative, may result in nausea, vomiting, confusion, convulsion and acute psychosis. The dehydrofolate reductase inhibitors used in malaria treatment are sulfadoxine, dapsone, proguanil (chloroguanide), trimethoprim and pyrimethamine. Most of these drugs are given in combination. Proguanil is one of the safest antimalarials. Convulsion, coma and blindness have been reported in pyrimethamine overdose. Sulfadoxine can induce Lyell and Stevens-Johnson syndromes. The main feature of dapsone poisoning is severe methaemoglobinaemia which is related to dapsone and to its metabolites. Recent toxicokinetic studies confirmed the efficacy of oral activated charcoal, haemodialysis and haemoperfusion in enhancing removal of dapsone and its metabolites. No overdose has been reported with artemesinine, a new antimalarial tested in the People's Republic of China. The general management of antimalarial overdose include gastric lavage and symptomatic treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Clinical features and management of poisoning due to antimalarial drugs. 330 66

Intraerythrocytic malaria parasites feed on their host cell cytosol. We show that human red blood cells infected with the malaria parasite Plasmodium falciparum, produce free amino acids the composition of which resembles that of globin, the most abundant red blood cell protein. The rate of amino acid production is almost equal to the rate of efflux of these acids from the infected cell. Production of amino acids increases with parasite age: the rates of production at the young ring and the mature trophozoite stages were 3.3 and 13.5 nmol/10(8) infected cells per min at 37 degrees, respectively, compared with 0.04 nmol/10(8) cells per min in uninfected cells. The quinoline-containing antimalarial drugs, chloroquine, quinine and mefloquine, inhibit amino acid production at the same concentrations at which they inhibit parasite growth, but have no effect on the endogenous parasite protein degradation. We suggest that parasite feeding on host cell cytosol is the primary target for the antimalarial action of these drugs. Chloroquine accumulation, the rate of amino acid production by infected cells and the inhibitory effect of the drug, were determined simultaneously at the different stages of parasite development. At all stages the rate of amino acid production and chloroquine accumulation were directly related and both were inversely related to the inhibitory efficiency of the drug. The lysosomotropic agents methylamine and NH4Cl at millimolar concentrations also inhibit amino acid production, suggesting that the process is pH dependent and localized in the vacuole. Host cytosol degradation and drug accumulation both take place in the parasite food vacuole. Our observations imply that the metabolically dependent acidification of this parasite organelle is involved in both processes.
 ...
PMID:Digestion of the host erythrocyte by malaria parasites is the primary target for quinoline-containing antimalarials. 352 76

The effect of 3 antimalarial quinoline derivatives, chloroquine, mefloquine and quinine on human blood mononuclear cells in vitro was studied. High concentrations profoundly suppressed the proliferation of mitogen- and antigen-stimulated lymphocytes, as indicated by decreased 14C-thymidine incorporation. On a weight base, the most potent drug was mefloquine. At clinically relevant doses, chloroquine and mefloquine did not affect the response to malaria antigens, but mefloquine decreased the response to phytohaemagglutinin; quinine suppressed the response to all mitogens (with the exception of pokeweed mitogen) and antigens studied, including P. falciparum merozoites. The drugs' potential adverse effect on the immune system is discussed.
 ...
PMID:In vitro effect of chloroquine, mefloquine and quinine on human lymphocyte proliferative responses to malaria antigens and other antigens/mitogens. 353 50

Over the last decade, chloroquine-resistant falciparum malaria has spread to other areas from its original foci in Southeast Asia and South America. Additionally, new knowledge about the life-cycle of the malaria parasite, and about the pharmacokinetic properties of antimalarial drugs, has emerged. It is appropriate to reassess our approach to prevention and management of malaria with these factors in mind. Antimalarial drugs can be classified in two ways: biologically as tissue schizontocides, hypnozoitocides, blood schizontocides, gametocytocides or sporontocides; or by a mixed chemical/biological classification as 8-aminoquinolines, antimetabolites and (again) blood schizontocides. Chloroquine resistance in P. falciparum can now be found in most areas where malaria occurs. Malarial strains moderately resistant to the chloroquine group of drugs (chloroquine and mepacrine) are generally susceptible to the aryl amino alcohols such as quinine. Indeed, quinine is the most widely used drug for treating malaria due to chloroquine-resistant strains, followed by a 7-day course of tetracycline where some resistance to quinine is also found. Alternatively, the course of quinine may be followed by sulfadoxine/pyrimethamine or the newer quinoline derivative, mefloquine. Quinidine has also shown activity against quinine-resistant strains. Prophylaxis of chloroquine-resistant strains is best undertaken with daily proguanil (chloroguanide), and weekly chloroquine. In severe malaria, including cerebral malaria, an intravenous loading dose of quinine should be considered, and plasma concentration monitoring may be advisable to assist with dosage adjustment. In patients with severe renal insufficiency, there is evidence that the elimination of chloroquine is prolonged, and dosage adjustments may be necessary. Other recent findings on the pharmacodynamic properties, mechanisms of action and toxicity of antimalarial drugs are also discussed.
 ...
PMID:Antimalarial drugs. An update. 354 65

Two new investigational antimalarial drugs developed by the U.S. Army Malaria Research Program were tested in patients with multi-drug-resistant falciparum malaria from Vietnam. WR 33063, a phenanthrene methanol, cured 13 patients treated in the United States. All of these patients had suffered multiple recrudescences after treatment with standard antimalarial drugs. In addition, 23 of 25 patients with acute attacks of falciparum malaria treated in Vietnam were cured. The rate of clinical response was prompt. WR 30090, a quinoline methanol, similarly cured eight patients with multiple recrudescences in the United States and 23 of 26 patients in Vietnam. Adverse effects associated with the drugs were not seen. These drugs signify a major advance in the chemotherapy of drug-resistant falciparum malaria.
 ...
PMID:Treatment of falciparum malaria from Vietnam with a phenanthrene methanol (WR 33063) and a quinoline methanol (WR 30090). 459 17

The authors describe a patient with the cerebral form of tropical malaria. The diagnosis was made about one hour after admission to hospital, and owing to this it was possible to start successful treatment with 4-quinoline preparations. The clinical diagnosis was confirmed by examination of stained preparation of peripheral blood. It is stressed that manifestations of acute encephalitis regressed rapidly after administration of 4-quinolines, and that parasitaemia persisted for a long time after regression of the acute phase despite absence of objective and subjective abnormalities.
 ...
PMID:[A case of cerebral form of tropical malaria]. 634 75

The spread of multiresistant strains of Plasmodium falciparum in south-east Asia and South America and the appearance of chloroquine resistance in Africa indicates the urgent need for alternative drugs against these parasites. Mefloquine, a 4-quinoline methanol, is the only new drug that is currently at an advanced stage of development.Studies in animal models and in the clinic have shown that it is highly active as a blood schizontocide against strains that are resistant to many established antimalarials, e.g., chloroquine and pyrimethamine. It is not, however, effective as a causal prophylactic agent. Preclinical toxicological, teratological, and carcinogenicity studies do not indicate any major contraindications to its use.Intensive clinical studies have been carried out in Africa, North and South America, south-east Asia, and Europe. These studies have indicated that the compound is generally well tolerated, safe, and effective in the treatment of malaria, particularly infections with chloroquine-resistant parasites.In order to protect this new and promising drug against the development of resistance to it in endemic areas, it is important that its introduction should be accomplished in a rational and deliberate manner. Appropriate precautionary measures include the development of mefloquine combinations (a combination of mefloquine with pyrimethamine-sulfadoxine is presently under investigation), its use with primaquine as a gametocytocidal drug to prevent transmission, and its deployment primarily for treatment, being used for prophylaxis only in special risk groups.
 ...
PMID:Development of mefloquine as an antimalarial drug. UNDP/World Bank/WHO update. 640 67


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>