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)

Starting from ancient reports that rare samples of methylene blue were apparently sufficiently contaminated with azures to give red plasmodial and red purple nuclear chromatin in Chenzinsky type methylene blue eosin stains, it was decided to determine how little azure B would suffice for such staining in methylene blue eosin stains. The traditional 1902 Giemsa had an azure : methylene blue : eosin ratio of about 6 : 3 : 6.3 : 10; Lillie's 1943 formula had a 5 : 7 : 10 ratio. In the current series of tests 5 : 7 : 10 (I), 4 : 8 : 10 (II), 3 : 9 : 10 (III), 2 : 10 : 10 (IV), 1 : 11 : 10 (V), and 0 : 12 : 10 (VI) were used. Malaria and blood stains were better than the standard 5 : 7 : 10 (I) in III, IV and II in that order. Normal and leukemic human blood, mouse blood with Plasmodium berghei, and monkey blood with the CDC strain of Pl. falciparum were used as test materials. The staining mixtures were made from highly purified samples of azure B and methylene blue. Staining mixtures contained 12 ml 0.1% thiazin dye, 10 ml 0.1% eosin, 2 ml each of glycerol, methanol and 0.1 M phosphate buffer pH 6.5, 3 ml acetone as accelerator, and distilled water to make 40 ml; staining times of 10--30 min were used.
 ...
PMID:Lower azure B methylene blue ratios in Giemsa type blood and malaria stains. 66 46

Quinine was compared with a 9-phenanthrene methanol (WR33063) and a 4-quinoline methanol (WR30090) for the treatment of 207 patients with falciparum malaria in Southeast Thailand. Quinine eradicated parasitaemia (average 70 hours) more rapidly than either WR30090 (72 hours) or WR33063 (77 hours). But WR33063 had a higher cure rate (92%) than WR30090 (86%) or quinine (85%). The mean duration of fever and of parasitaemia were combined with the failure rate to form an arbitrary efficacy index. Using this concept WR33063 was the most effective drug. The recrudescence rate correlated with the degree and duration of parasitaemia and with the duration of fever. WR33063 was the least toxic drug. Side effects associated with WR30090 appeared to be headache, backache and urticaria. Quinine was the most toxic drug. All 3 drugs were inconvenient in having to be administered every 8 hours for 6 days. One patient did not respond to oral quinine but did respond to an intravenous quinine infusion (IVQ). A "Medication Ward Round" was perfected during the study and comprised sequential history, drug administration, physical examination, dose notation and patient observation. Falciparum nephrosis was diagnosed in one patient.
 ...
PMID:Comparison of a 9-phenanthrene methanol (WR33063), a 4-quinoline methanol (WR30090), and quinine for falciparum malaria in Thailand. 110 64

Paludism can occur quite easily in pregnant women in endemic zones, above all those who are primiparous or in their 2nd or 3rd terms. The onset of paludal attacks can be serious for both the mother and the child. That is to say, besides the obviously imperative therapeutic action, a prophylaxis is also a necessity. The use of antipaludial substances at our disposal has been complicated during the last few years as a result of chloroquine-resistance extension. Besides a few nuances of kinetic nature observed in pregnant women, a good knowledge of teratogenous or embryotoxic effects is necessary. But this remains fragmentary. Among the principal antipaludial medications is quinine (Q), reported to be abortifacient but in reality it is not: it is often poorly tolerated by the mother (hypoglycemia), but is not responsible for abnormalities in children, except under large doses. Chloroquine (CQ), considered to be without harmful effects, can be used in women without large restrictions, even if toxic effects have been observed in animals. The pyrimethamine-sulfanilamide (P-S) combination contains two substances which are a potential risk. Nevertheless, experiments have never showed harmful effects in pregnant women, particularly when under cover of a joint prescription of folinic acid. Proguanil is without doubt the only molecule which can be used without restriction. Two new medications, quinoline methanol, Mefloquine (MQ) and Halofantrine (HF) are contra-indicated for lack of experimentation and because of some abnormalities observed at high doses in animals. Artemisinine and amino-8-quinoline are contra-indicated, and cyclines are strongly inadvised. From the practical point of view, the present use of antipaludial medication in pregnancy should take into account the surrounding risk, namely that of paludism and of treatments. Curatively, Q remains a serious treatment in any form. In CQ-sensitive zones CQ is usable unreservedly in simple attacks. In CQ resistance zones the use of Q seems preferable to that of Fansidar proposed by certain people. MQ and HF, although contra-indicated, have already been employed without inconvenience. By way of prevention, it is important first of all to avoid all leisure stays in endemic zones. If travel is unavoidable or for indigenous people, a chemoprophylaxis, judged according to the local risk of impaludation, is desirable: CQ in sensitive zones, PG+CQ in resistant zones, P-S, as proposed by some people, is normally contra-indicated; MQ and HF are contra-indicated. Protection against nocturnal mosquito bites is still strongly applied (Mosquito net, repellents, insecticides).
 ...
PMID:[Antimalarials and pregnancy]. 181 22

Mefloquine, a quinoline-methanol antimalarial, is effective single dose therapy for all species of malaria infecting humans, including multi-drug-resistant Plasmodium falciparum. It is used both in prophylaxis and treatment. Mefloquine is available either as the hydrochloride salt alone, or in a combined preparation with sulfadoxine and pyrimethamine. There is no parenteral formulation. Several assay methodologies have been developed, but high performance liquid chromatography has been the most used in recent pharmacokinetic studies. These have shown in healthy volunteers that mefloquine is absorbed with a half-life of 1 to 4 hours and a time to peak concentration of 7 to 24 hours (median 16.7 hours). Mean peak blood concentrations have ranged between 50 and 110 (median 83) ng/ml/mg/kg. Estimates of total apparent volume of distribution (Vd/f) have ranged from 13.3 to 40.9 (median 19.2) L/kg, systemic clearance (CL/f) from 0.022 to 0.073 L/h/kg (median 0.026 L/h/kg), and terminal elimination half-life from 13.8 to 40.9 days (median 20 days). Systemic clearance appears to be increased in late pregnancy. In uncomplicated falciparum malaria, peak blood concentrations are 2 to 3 times higher than those in healthy subjects ranging from 112 to 209 (median 144) ng/ml/mg/kg because of contraction in the total apparent volume of distribution. Systemic clearance is usually reduced but elimination rates are increased (possibly because of reduced enterohepatic recycling). Mefloquine absorption appears to be reduced in severe falciparum malaria; plasma protein binding exceeds 98% in both healthy subjects and patients. No important drug interactions have been identified as yet, but the potential for serious interactions with quinine has not been adequately investigated. More studies are needed on the disposition of mefloquine in children.
 ...
PMID:Clinical pharmacokinetics of mefloquine. 220 97

A rapid and highly sensitive high-performance liquid chromatographic assay for thymidylate synthase activity is described. The assay is based on the separation of the substrate, deoxyuridylate (dUMP), and its product, deoxythymidylate (dTMP), on a LiChrosorb RP-8 reversed-phase column with 44 mM triethylammonium phosphate (pH 7.0) as mobile phase and a flow-rate of 1.0 ml/min. In addition, using a mu Bondapak C18 reversed-phase column with 10 mM potassium phosphate (pH 4.0) and a gradient of 0-28% methanol, dUMP, dTMP and deoxythymidine (dTdR) are well separated within 30 min. The latter system is also applied to assay thymidine kinase activity with dTdR and dTMP as substrate and product, respectively. This method is sensitive enough to measure dTMP at concentrations as low as 25 pmol, and it was used to show that crude extracts of the human malaria parasite Plasmodium falciparum contain thymidylate synthase but not thymidine kinase activity.
 ...
PMID:High-performance liquid chromatographic assay for thymidylate synthase from the human malaria parasite, Plasmodium falciparum. 265 57

Two clinical trials of the phenanthrene methanol compound halofantrine in the treatment of Plasmodium falciparum were conducted in Malawi, in areas where the parasite was known to be chloroquine resistant. In the first trial all 46 patients had symptoms of malaria and parasite densities ranging from 2500/microliter to 212,000/microliter. They were given a single dose of halofantrine hydrochloride, 16 mg/kg body weight. The recrudescence rate on day 14 of follow up was unacceptably high (38%). In the second trial the dose given was 8 mg/kg 6 hourly for three doses. Of the 49 children followed up for 14 days, 47 became aparasitaemic--ie, the cure rate was 96%. In both trials the drug was very well tolerated. Halofantrine hydrochloride seems to be effective against P falciparum chloroquine sensitive and resistant strains in Africa.
 ...
PMID:Clinical trials with halofantrine hydrochloride in Malawi. 289 38

Halofantrine (WR 171.669) is a phenanthrene methanol derivative effective against the multidrug resistant strains of Plasmodium falciparum. One hundred and one patients, 48 men and 53 women, 53 adults and 48 children (less than or equal to 12 years old) aged from 1.5 to 57 years were treated. Fifty-one patients received a single 16 mg/kg dose and 50 patients received 24 mg/kg/day in 3 doses at 6-hour intervals. Parasite counts with examination of both thin and thick smears were performed twice daily for 5 to 6 days following treatment, or until smears were negative for parasites for 24 hours, and then weekly for 4 weeks. Thirteen patients reported clinical side effects. Six treated patients had no parasites. One patient had mixed parasitemia. Eighty three patients had P. falciparum malaria, with mean parasitemias between 26,850 +/- 36,679 and 35,412 +/- 50,527 per cubic millimeter. Halofantrine was very effective in the two doses tested from 87.5 to 100 p. 100. Eleven patients had in vivo resistant strains; ten in vitro tests were successful and nine were resistant to chloroquine. Thirteen patients with P. vivax and a mean parasitemia of 13,858 +/- 10,835 per cubic millimeter were cured but 3 had a relapse 3 to 4 weeks after treatment. At the 2 dosage levels tested halofantrine proved highly effective in the treatment of malaria caused by resistant and sensitive strains to P. falciparum.
 ...
PMID:[Efficacy of halofantrine in Plasmodium falciparum or Plasmodium vivax malaria in a resistance area (French Guiana)]. 296 6

To evaluate the state of ferriprotoporphyrin IX (FP) in malaria pigment, mouse erythrocytes infected with Plasmodium berghei NYU-2 parasites were lysed by hypotonic shock, and hemoglobin and other soluble material were removed by extensive washing. The amount of FP recovered in the insoluble pellet was 2.1 mumol/ml of packed infected erythrocytes, of which approximately 1% was attributable to hemoglobin contamination. This crude preparation then was digested with a nonspecific protease from Streptomyces griseus and extracted with chloroform/methanol. The residue of insoluble dark brown material had the spectral and solubility properties characteristic of the FP of malaria pigment, and various different preparations contained from 82 to 99% of FP by weight. By elemental analysis, highly purified preparations contained no chlorine and had an oxygen content consistent with 1 mol of hydroxyl/mol of FP (oxygen content: calculated, 12.6%; found, 12.5%). In comparison to hematin purchased from Sigma, which had a measured oxygen content of 14.7%, the low oxygen form of hematin purified from malaria pigment was remarkably less soluble in ethanol, 3% sodium bicarbonate, and chloroform.
 ...
PMID:The state of ferriprotoporphyrin IX in malaria pigment. 311 78

A high-performance liquid chromatographic (HPLC) method using fluorescence detection is described for the quantification of hydroxychloroquine (HCQ) and three of its metabolites in blood and urine samples. The method is selective, permitting quantification of analytes without interferences from chloroquine or quinine in the sample. Detection limits for HCQ, desethylhydroxychloroquine, desethylchloroquine, and bisdesethylchloroquine are 10, 30, 5, and 5 ppb, respectively, for a 100-microliters blood or urine sample. The internally standardized method requires only one extraction step and utilizes normal-phase HPLC conditions including an amine modifier in the mobile phase. These conditions facilitate fluorescence detection, selective separation, and acceptable peak shapes. A mobile phase of 0.5% n-butylamine in methanol-hexane-methyl tert. butyl ether (1:1:1) is used in the analysis. Analysis of blood and urine samples from two healthy volunteers given 400 mg of Plaquenil (310 mg of HCQ base) weekly for four weeks provided data on HCQ metabolism for the two persons during the recommended chemoprophylactic regimen for malaria.
 ...
PMID:Analysis of blood and urine samples for hydroxychloroquine and three major metabolites by high-performance liquid chromatography with fluorescence detection. 323 47

Halofantrine is a 9-phenanthrene-methanol effective against multiresistant strains of Plasmodium falciparum. It is extremely effective and well-tolerated in treating cases of malaria imported into France. 1,500 mg in 3 doses at 8 hour intervals produced 100% cure rate in semi-immune patients. This dosage could be repeated after 14 days in order to obtain the same cure rate in non-immune patients. Side-effects are minor and include epigastric pain, nausea and one case of skin rash.
 ...
PMID:[Treatment with halofantrine of Plasmodium falciparum malaria imported into France]. 391 50


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