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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The susceptibility of the chloroquine-resistant malaria parasite Plasmodium falciparum (FCR-3) to a pyridoxal-based iron chelator was tested. 10 microM of the chelator 1[N-ethoxycarbonylmethyl-pyridoxy-lidenium]-2-[2'-pyri dyl] hydrazine bromide (code name L2-9) effectively inhibited growth in vitro of the parasites. Presaturation of the chelator with either ferric or ferrous iron partially blocked the inhibitory effect. Two hours' exposure of parasites to 20 microM L2-9 was sufficient to inhibit their growth irreversibly. Desferrioxamine blocked the inhibitory effect of L2-9. It is suggested that the chelator may be acting by generating free radicals in complexing intracellular iron.
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PMID:Inhibition of Plasmodium falciparum growth by a synthetic iron chelator. 220 2

Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.
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PMID:Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro. 220 10

Prenatal care, the most important factor determining the outcome of pregnancy, is limiting in developing countries either because of no or inadequate facilities or underutilization. WHO estimated that only 29-36% of African, 20-61% of Asian and 69-89% of South American births have maternity care. Existing services and underutilized because of illiteracy, the most important factor, cultural practices, religious practices, and the subordinate status of women. Care in developing countries is exemplified by describing prenatal care in urban University College Hospital, Ibadan, Nigeria, in a rural town of 30,000 in Western Nigeria and in the Ibarapa District in 1989, and care by TBAs. Routine care provided in the rural clinics included Talqvist hemoglobin count, history to determine Sickling, iron, folic acid and antimalarials if available, and referral to the weekly consultant clinic if the woman is under 5 ft in height, primigravid and 36 weeks gestation, uncertain of dates, has discrepancy in fundal height for dates, is ill or has history suggestive of abnormal pregnancy. Pregnant women usually used the clinic for antenatal care, but only 45% delivered in maternities. The review ends with brief discussions of management of malaria, anemia, hemoglobinopathy, malnutrition and teenage pregnancy. Anemia, common to all, is managed by transfusion of packed cells with administration of a loop diuretic to prevent hear failure.
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PMID:Antenatal care in developing countries. 220 29

This overview of health programs and conditions in India reveals that health is related to economic development antipoverty measures, food production and distribution, drinking water supply, sanitation, housing, environmental protection, and education. There are urgent requirements for effective intersectorial coordination. Unprecedented growth of 1 million a year has resulted in slums and shanties--a place of epidemics; urbanization has contributed to environmental pollution impacting on health, and water pollution to water-born diseases. Health services are still insufficient to meet the needs. Sanitation practices contribute to cholera, dysentery, diarrhea, enteric fevers, and malaria. Indian Systems of Medicine and Homeopathy must be active in preventive and health care. Accomplishments include in 1987/8 a decline in leprosy cases attributed to the existence of leprosy control units. 40 AIDS Surveillance Units are actively treating and screening. The Naval Goitre Control Programme's goal is replacement of iodized salt for edible salt by 1992, thereby reducing mental retardation and low birth weight babies. The Family Welfare Programme, targets a New Production Rate of Unity before 2000. A National Technology Mission on immunization and the Universal Immunization Programme plans to be operational in all districts by 1990. Oral rehydration therapy programs dispense free packets to fill the needs of 1 million children under 5 who suffer from diarrhea 3 times a year with 3 million facing death. The Primary Health Care Programme provides iron and folic acid to women with nutritional anemia and Vitamin A to children. Health service developments have been increased.
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PMID:Status of health in India and its future prospects. 226 69

Plasma from mice heavily parasitized by Plasmodium vinckei vinckei was found to contain micromolar levels of iron as detected by the 'bleomycin assay' (slightly modified) of Gutteridge et al. [(1981) Biochem. J. 199, 263-265]. Uninfected mouse plasma contained little or no bleomycin-detectable iron. Plasma ultrafiltrate from infected mice contained no bleomycin-detectable iron, indicating that such iron was associated with the protein/macromolecule fraction. We speculate that this iron could catalyse reduction of peroxides in vivo and thus play a role in malaria pathology.
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PMID:Bleomycin-detectable iron in plasma from Plasmodium vinckei vinckei-infected mice. 241 84

In order to determine whether giving iron to iron-deficient children increases their susceptibility to malaria, 213 Gambian children aged between 6 months and 5 years with iron-deficiency anaemia were randomized to receive either oral iron or placebo during the rainy season when malaria transmission is maximal. Haematological and iron measurements improved significantly in the group given iron. Regular morbidity surveys showed that fever associated with parasitaemia occurred more frequently in the iron-treated group than in the placebo group. This difference was not significant for all parasitaemias grouped together, but became significant and progressively larger for parasitaemias of ten or more positive fields per 100 high power fields (P less than 0.025), and for parasitaemias of 50 or more positive fields per 100 high power fields (P less than 0.01). Three children in the iron-treated group but none in the placebo group had more than one episode of fever and parasitaemia. Splenomegaly rates rose appreciably during the study in both groups, but in children at age 2 years the splenomegaly rate at the end of the study was significantly greater in the iron-treated group. We concluded that there is a significantly increased risk of fever associated with severe malarial parasitaemia for children with iron-deficiency anaemia given iron during the season of maximal malaria transmission in this part of The Gambia.
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PMID:The effects on malaria of treatment of iron-deficiency anaemia with oral iron in Gambian children. 247 38

Haematological and iron parameters, measured in 907 children aged from 6 months to 5 years in rural Gambia at the start of the rainy season, differed from those in American reference populations as follows: mean haemoglobin levels were much lower at ages 1 and 2 years and mean levels of mean corpuscular volume (MCV) were lower at all ages (at age 1 year mean haemoglobin was 11.2 g/dl and mean MCV 68.2 fl); in a sample of 249 children randomly selected from the whole study population, mean serum iron levels were similar but mean transferrin saturation and mean serum ferritin levels were lower, especially at ages 1-3 years (at age 1 year mean serum iron was 11.1 mumol/l, mean transferrin saturation 16.9%, and geometric mean serum ferritin 8.8 ng/ml. A total of 213 children (23%) whose haemoglobin and mean corpuscular volume were both less than the 3rd percentile of the reference population received oral iron or placebo from their mothers during the rainy season when malaria transmission is maximal. Mean levels of haemoglobin, mean corpuscular volume, serum iron, transferrin saturation and serum ferritin rose in the iron-treated group and fell in the placebo group at all ages, except under 1 year for serum ferritin, to produce significant differences between the groups by the end of the study. Total iron-binding capacity showed no significant changes during the study. We concluded that oral iron given by the mother during the rainy season can be used to treat iron-deficiency anaemia in Gambian children who would otherwise become more anaemic.
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PMID:Iron-deficiency anaemia and its response to oral iron: report of a study in rural Gambian children treated at home by their mothers. 247 48

Iron deficiency is prevalent in childhood in the developed and developing countries. Programs of presumptive therapy, mass supplementation and food fortification have been introduced in many countries. The unresolved debate over the interaction of iron and infection in the clinical setting prompts re-evaluation of these practices. Situations of iron overload are associated with increased susceptibility to certain infections, although the exact mechanisms may vary with the main pathology. Iron treatment has been associated with acute exacerbations of infection, in particular malaria. In most instances parenteral iron was used. In the neonate parenteral iron is associated with serious E. coli sepsis. In one country, with endemic malaria, parenteral iron was associated with increased rates of malaria and increased morbidity due to respiratory disease in infants. In contrast in non-malarious countries studies of oral iron supplementation have if anything shown a reduction in infectious morbidity. Methodological problems in the latter reports indicate the need for further controlled prospective studies with accurate morbidity recording if informed recommendations are to be made.
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PMID:Iron and infection: the clinical evidence. 187 85

Previous studies showed that deferoxamine inhibits malaria by interacting with a labile iron pool within parasitized erythrocytes. Consequently, we studied the antimalarial properties of other iron-chelating drugs such as 2,3-dihydroxybenzoic acid (2,3-DHB) and its methyl ester as well as two polyanionic amines, N.N'-bis (o-hydroxybenzyl) ethylenediamine-N,N'-diacetic acid (HBED) and N,N'-ethylenebis(o-hydroxyphenylglycine) (EHPG) in rats infected with Plasmodium berghei. All drugs were delivered by subcutaneous injection at 8-hour intervals, 40 mg per animal per day. All animals receiving N,N'-ethylenebis(o-hydroxyphenylglycine) died of drug toxicity between days 6 and 11. Peak parasitemia on day 11 of infection was 32.8% in control animals; 25.3% with methyl 2,3-DHB, 15.5% with 2,3-DHB, 8.0% with deferoxamine, and 0.9% with HBED. Subsequent studies of HBED and deferoxamine in P falciparum cultures in human erythrocytes showed a marked suppression of parasite counts by both drugs at concentrations of greater than 5 mumol/L. At all concentrations tested, HBED was four to five times more effective than deferoxamine in suppressing parasite counts. The superior antimalarial activity of HBED is attributed to its increased lipophilicity and higher affinity to ferric iron. These findings indicate that selective iron deprivation by interaction with an intracellular chelator may represent a novel approach to antimalarial drug development, and that systematic screening of available iron-chelating drugs may result in identification of potentially useful antimalarial compounds.
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PMID:Antimalarial effect of HBED and other phenolic and catecholic iron chelators. 250 94

New studies on the suppressive and curative effects of the anti-malarial drug pyrimethamine in pregnant women from Ilorin, Nigeria showed both ineffective prophylaxis and suppression, and parasite resistance. The drug has been used in pregnant women because of its effectiveness in suppression of asexual forms of malaria infections due to Plasmodium falciparum, its long half life and its safety. 1st a group of 88 pregnant women infected with only P falciparum received 25 mg pyrimethamine weekly for 4 weeks and parasites were counted on blood smears. 67% retained parasites by Day 7, and 60% by Day 14. All were treated with curative doses of chloroquine. A 2nd group of 71 pregnant women were first treated for malaria parasites with 2 doses of chloroquine, 25 mg/kg, in 300 mg tablets, followed by weekly pyrimethamine 25 mg for 10 weeks. All subjects and controls were given iron and folic acid supplements to take daily. 24% developed parasitemia during the 10 weeks of the study, compared to 30% of the controls. The mean intervals to development of parasitemia, and the geometric mean parasite density in blood did not differ significantly. In 6 of 10 in vitro tests of parasite resistance to pyrimethamine, parasite growth was uninhibited, compared to 22 of 23 tests for resistance to chloroquine. In vivo and in vitro tests correlated well for pyrimethamine resistance. The results also indicated that primigravidae, who are more likely to harbor malaria parasites, were also more likely to fail in parasite suppression with pyrimethamine treatment. Thus pyrimethamine is not expected to reduce incidence of premature and low birth weight infants due to malaria in this area.
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PMID:Lack of efficacy of pyrimethamine prophylaxis in pregnant Nigerian women. 196 44


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