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)

Sodium concentrations and osmolalities of simultaneously obtained venous blood and urine have been determined in a total of 61 children consisting of 18 children with malaria infection, 18 children with measles infection and 25 age- and sex-matched controls. The mean plasma osmolalities in the malaria and measles groups were significantly lower than in the control group (p less than 0.01). There was no difference between the measles and malaria groups either in their plasma osmolality (p greater than 0.20) or urine osmolality (p greater than 0.10). The u/p ratios for both osmolality and sodium concentrations where significantly higher for both the measles and malaria groups than for the matched controls. There was no difference in the u/p values between the malaria and measles groups (0.02 greater than p greater than 0.10). We conclude from these results that measles and malaria infected children demonstrate inappropriate secretion of ADH. Every child with these conditions should be carefully evaluated for the detection of evidence of SIADH. This is more important for children with measles who are frequently anorexic and may need intravenous infusion for maintenance of hydration.
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PMID:Syndrome of inappropriate antidiuretic hormone (SIADH) in measles and malaria infections. 702 95

Iron in food is classified as belonging to the haem pool, the nonhaem pool, and extraneous sources. Haem iron is derived from vegetable and animal sources with varying bioavailability. Hookworm infestation of the intestinal tract affects 450 million people in the tropics. Schistosoma mansoni caused blood loss in 7 Egyptian patients of 7.5- 25.9 ml/day which is equivalent to a daily loss of iron of .6-7.3 mg daily urinary loss of iron in 9 Egyptian patients. Trichuris trichiura infestation by whipworm is widespread in children with blood loss of 5 ml/day/worm. The etiology of anemia in children besides iron deficiency includes malaria, bacterial or viral infections, folate deficiency and sickle-cell disease. Severe infections cause profound iron-deficiency anemia in children in central American and Malaysia. Plasmodium falciparum malaria-induced anaemia in tropical Africa lowers the mean haemoglobin concentration in the population by 2 g/dI, causing profound anaemia in some. The increased risk of premature delivery, low birthweight, fetal abnormalities, and fetal death is directly related to the degree of maternal anemia. Perinatal mortality was reduced from 38 to 4% in treated anemic mothers. Mental performance was significantly lower in anemic school children and improved after they received iron. Supplements of iron, soy-protein, calcium, and vitamins given to villagers with widespread malnutrition, iron deficiency, and hookworm infestation in Colombia reduced enteric infections in children. Severe iron-deficiency anemia was treated in adults in northern Nigeria by daily in Ferastral 10 ml, which is equivalent to 500 mg of iron per day. Choloroquine, folic acid, rephenium hydroxynaphthoate, and tetrachlorethylene treat adults with severe iron deficiency from hookworm infestation in rural tropical Africa. Blood transfusion is indicated if the patient is dying of anaemia or is pregnant with a haemoglobin concentration 6 gm/dl. In South East Asia, mg per day prevented iron-deficiency anaemia in pregnancy. Field-trials on nutritional iron deficiency include an acidified milk formula plus ferrous sulphate for infants; biscuits with added bovine hemoglobin for children in Chile; sugar plus sodium ferric EDTA in Guatemala; salt with ferric orthophosphate and sodium acid sulphate in India; and Salt with ferrous sulphate plus sodium hexametaphosphate.
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PMID:Iron deficiency in the tropics. 704 57

A cell-ELISA was developed using monolayers of glutaraldehyde-fixed normal as well as Plasmodium berghei-infected mouse erythrocytes for quantification and characterization of anti-erythrocytic autoantibodies in murine malaria. Testing normal (NMS) and peak parasitaemic sera (PPS) on erythrocyte monolayers treated with trypsin, sodium meta periodate, neuraminidase or heat, and competitive inhibition of antibodies with soluble sialic acid, revealed that some anti-erythrocytic antibodies (which increase during the parasitaemic phase of infection) recognize N-acetyl neuraminic acid (NANA) residues on host erythrocytes. High levels of antibodies to NANA covalently conjugated to bovine serum albumin (BSA) were detectable in PPS. Such antibodies could be significantly absorbed out by preincubation of PPS with mouse erythrocytes (MRBC). Antibodies in PPS, when affinity-purified on a column of Fetuin-Agarose, were found to be reactive to normal as well as parasitized erythrocyte monolayers. Immunoglobulin isotyping and IgG subgroup typing revealed that most of the anti-erythrocytic autoantibodies in NMS were IgM and IgA, while in PPS there was an appreciable increase in IgG2a and IgG3. Affinity-purified anti-NANA antibodies reacted with DNA when tested in an ELISA. There was a significant positive correlation between anti-erythrocytic antibody and DNA-binding levels in NMS as well as PPS. The DNA-binding antibodies in PPS could be effectively absorbed out by preincubation of sera with fresh MRBC. Affinity determination of anti-erythrocytic antibodies eluted from MRBC revealed binding characteristics in the following order: MRBC > single-stranded DNA > double-stranded DNA.
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PMID:Murine malaria: anti-erythrocytic antibodies recognize N-acetyl neuraminic acid residues. 750 18

Following invasion by the malaria parasite there appear in the parasitized erythrocyte new ("induced") permeation pathways that mediate the transport of a wide variety of small solutes. Although anion-selective, these pathways have a significant cation permeability and cause a substantial increase in the basal leak of cations into and out of the infected cell. In this study of human erythrocytes infected in vitro with Plasmodium falciparum it was shown that the transport of monovalent cations (Rb+ and choline), but not that of a nonelectrolyte (sorbitol) or a monovalent anion (lactate), via the malaria-induced pathways is strongly dependent on the nature of the anion in the suspending medium. Substitution of NO3- for Cl- resulted in a 4-6-fold increase in the unidirectional influx and efflux of Rb+, and a 2-3-fold increase in the influx of choline via the induced pathways. By contrast, replacement of Cl- with NO3- caused a slight (although not significant) decrease in the malaria-induced influx of sorbitol and lactate. Hemolysis experiments with a range of K+ salts revealed that the net influx of K+ into infected cells showed the same novel anion dependence as seen for the unidirectional flux of Rb+ and choline, with hemolysis occurring much faster in iso-osmotic KNO3 and KSCN solutions than in KCl, KBr, or KI solutions. Hemolysis in the corresponding Na+ salt solutions was very much slower, consistent with the induced pathways being selective for K+ over Na+, and raising the possibility that the efflux of cell K+ via these pathways may play a role in host cell volume regulation. A number of models that would account for the anion dependence of malaria-induced cation transport are considered.
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PMID:Novel anion dependence of induced cation transport in malaria-infected erythrocytes. 759 35

Lactic acidosis frequently complicates severe malaria in African children, and is a strong independent predictor of mortality. We tested the hypothesis that sodium dichloroacetate (DCA), an activator of pyruvate dehydrogenase, rapidly reduces hyperlactataemia in this patient population. Eighteen children with severe malaria and capillary plasma lactate > or = 5 mM were randomized to receive either intramuscular quinine plus a single 50 mg/kg intravenous infusion of DCA in saline, or quinine plus intravenous saline alone. Two patients in each treatment group died following randomization. Thirty minutes after treatment, the mean plasma lactate was 28% below pretreatment baseline values in the DCA group, but was unchanged in the placebo group. Throughout the first 4 h after treatment, mean plasma lactate in the DCA-treated patients was significantly less than that in controls (p = 0.003). Thereafter, mean plasma lactate declined in both groups and was < 2 mM 10 h after treatment. DCA was well tolerated and did not alter quinine pharmacokinetics. A single intravenous dose of DCA rapidly improved lactic acidosis in African children with severe malaria, suggesting that DCA may be a useful adjunct in the initial treatment of these patients, and may increase their chance of survival by improving a major complication of their illness.
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PMID:Pharmacokinetics and pharmacodynamics of dichloroacetate in children with lactic acidosis due to severe malaria. 779 89

In the district of Sahibganj, Bihar, India, there were 23,670 new cases of kala-azar between 1985 and 1990. The Social Development Centre, Dumka, drafted an emergency plan as a solution. 30 village health workers attended a 3-day training course regarding how to administer sodium stibogluconate intramuscularly, spray DDT, conduct door-to-door surveys, and refer affected persons to health centers. Kala-azar awareness programs in the villages imparted information on the treatment and control of the disease explaining that the disease could not be controlled by witch-doctors. DDT was sprayed during January/February and May/June on the inner walls of houses and covered cowsheds in order to eradicate sandfly prevalence. Persons who had had fever for more than 3 weeks underwent examinations for total and differential counts of white blood cells, haemoglobin concentration, aldehyde test, and thick and thin blood smears for the detection of malaria parasites. Treatment consisted of sodium stibogluconate given intramuscularly at 20 mg per kg body weight daily for 20 days in new cases and for 40 days in relapsed patients, with a maximum of 850 mg. Clinical cure was achieved if patients became afebrile and their spleens returned to normal size. If no relapse occurred in 6 months, the patients were regarded as definitively cured. Of the 1640 treated patients, 1592 were cured, and of the 48 patients who relapsed and were treated again with a 40-day course of sodium stibogluconate, 8 relapsed a second time. 44 patients became unresponsive to sodium stibogluconate and were sent to hospitals for treatment. The spraying performed by the village health workers reduced the incidence of kala-azar and malaria in 3 villages, while increased numbers of cases were recorded in 1 village. Remote tribal areas need educative, preventive, and curative programs backed up by mobile hospitals carrying diagnostic and spraying equipment.
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PMID:A kala-azar control programme for remote tribal communities. 794 51

The study evaluated six Plasmodium falciparum antigen extracts to be used in the IgG and IgM enzyme-linked immunosorbent assays (ELISA), for malaria diagnosis and epidemiological studies. Results obtained with eighteen positive and nine negative control sera indicated that there were statistically significant differences among these antigen extracts (Multifactor ANOVA, p < 0.0001). Urea, sodium deoxycholate and Zwittergent antigen extracts performed better than did the three others, their features being very similar for the detection of IgG antibodies. Urea, alkaline and sodium deoxycholate antigen extracts proved to be better than the others for the detection of IgM antibodies. A straight line relationship was found between the optical densities (or their respective log10) and the log10 of antibody dilutions, with a very constant slope. Thus serum titers could be determined by direct titration and by two different equations, needing only one serum dilution. For IgM antibody detections, log10 expression gave results that better correlated with direct titration (95% Bonferroni). For IgG antibody detections, the titer differences were not significant. The reproducibility of antibody titers and antigen batches was also evaluated, giving satisfactory results.
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PMID:Malaria serology: performance of six Plasmodium falciparum antigen extracts and of three ways of determining serum titers in IgG and IgM-ELISA. 799 52

The preparation of artemether from artemisinin is reviewed. Firstly, the extraction of artemisinin from Artemisia annua is described and an estimation of the yield per hectare based on literature data is given. Artemisinin is reduced with sodium borohydride to produce dihydroartemisinin as a mixture of epimers. The mixture is treated with methanol and an acid catalyst to provide artemether. Increasing demand for use of artemether places pressure on the supply of artemisinin, and an alternative means of preparing the drug from artemisinic acid, an abundant constituent of A. annua, which could triple current yields, is described. In anticipation of problems of drug resistance emerging with the continued use of artemether and artesunate to treat malaria, development of new derivatives of artemisinin which have enhanced stability is required. Examples of such derivatives which have been prepared in our laboratories, or proposed, are described.
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PMID:Extraction of artemisinin and artemisinic acid: preparation of artemether and new analogues. 805 18

Overhydration can contribute to fatal complications of falciparum malaria, even though renal function may be normal. In this context, the role of inappropriate secretion of antidiuretic hormone (ADH) has been controversial. Therefore, we have analyzed ADH serum concentrations together with serum osmolality and sodium levels in serum and urine of 17 consecutively studied patients with severe falciparum malaria. Serum sodium levels were low in 13 of 17 patients upon admission and returned to normal levels during antiparasitic therapy. Urine sodium levels were low in seven of 13 patients before treatment and increased during therapy. Urine sodium concentrations were high, however, in the remaining six patients. Serum osmolality was lower in these six patients than in the other seven hyponatremic patients (P < 0.002). In relation to serum osmolality, ADH levels were inappropriately high in these six patients, which confirms the presence of inappropriate secretion of ADH. Serum creatinine levels were not higher in these six patients than in those without inappropriate secretion of ADH. Inappropriate secretion of ADH seemed to be a major cause of hyponatremia, since other factors that could lead to this condition were not found in these six patients. In conclusion, we have shown, that human falciparum malaria can be associated with inappropriate secretion of ADH.
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PMID:Inappropriate secretion of antidiuretic hormone and hyponatremia in severe falciparum malaria. 820 10

WR 242511 (or I) is a new compound of the 8-aminoquinoline class designed to replace primaquine for the treatment of malaria. In order to perform preclinical and clinical testing, an assay was needed to determine drug levels in plasma samples. A simple and reliable reversed-phase high-performance liquid chromatographic (HPLC) method for the measurement of I in plasma using oxidative electrochemical detection is described. A 250-microliters plasma sample containing WR 256408 (or II) as internal standard was extracted with tert.-butyl methyl ether-2-propanol. A 25-microliters aliquot of the extractant was used for HPLC analysis. The mobile phase was 50:50 acetonitrile-sodium acetate (50 mM, pH 6) with 1 mM EDTA. Compounds I and II were separated within 10 min. The limit of detection for I was 10 ng/ml (plasma) with a recovery around 72%. The method was validated in a dog experiment where levels were followed for 48 h. The method is sensitive and robust and can be used for routine drug analysis during pharmacokinetic studies.
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PMID:High-performance liquid chromatographic method for the determination of a candidate 8-aminoquinoline antimalarial drug (WR 242511) using oxidative electrochemical detection. 837 17


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