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

We studied the effects of artesunate on rhesus monkeys infected with Plasmodium coatneyi. Sixteen rhesus monkeys were divided in four groups. Group I consisted of three monkeys that were splenectomized and were treated with three doses (loading dose: 3.3 mg/kg, maintenance doses: 1.7 mg/kg) of artesunate, group II consisted of three monkeys that were treated with three doses of artesunate (same as group I), group III consisted of two monkeys that were treated with one dose (3.3 mg/kg) of artesunate, and group IV consisted of five untreated monkeys. Parasitemias of these groups ranged from 13.3% to 19.5% before treatment. Twenty-four hours after administration, the parasitemia was reduced to 2.2% in group I and to < 0.1% in group II; parasitemia was lowered to 10.6% in group III only 3 hr after drug administration. The rate of sequestration in the cerebral microvessels, which was 29.4% in untreated animals, was < 0.1% in groups I and II (24 hr after treatment), and 2.0% in group III (3 hr after treatment). These data clearly indicate that artesunate not only reduced parasitemia, but also reduced the rate of parasitized red blood cell (PRBC) sequestration in cerebral microvessels. In an immunohistologic study, endothelial-leukocyte adhesion molecule-1 (ELAM-1) was not detected in group I after treatment with artesunate, although the presence of CD36, thrombospondin, intercellular adhesion molecule-1, IgG, and C3 in the cerebral microvessels was not altered. This is the first in vivo study to show that artesunate interferes with continued PRBC sequestration in the cerebral microvessels in cerebral malaria.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A nonhuman primate model for human cerebral malaria: effects of artesunate (qinghaosu derivative) on rhesus monkeys experimentally infected with Plasmodium coatneyi. 750 97

Proteose-peptone is a known powerful stimulator of macrophages. This stimulation was studied in an experimental malaria infection model, using Plasmodium berghei in mice. Parasitemia and mortality did not change in stimulated animals, and macrophage mobilization, contrary to other published papers, was not effective to increase either parasite levels in the blood or mortality.
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PMID:[Casual influence of the stimulation of macrophage production by proteose-peptone, in the experimental infection of mice by Plasmodium berghei]. 761 Mar 36

In a retrospective study we analyzed the clinical and blood chemical data of 12 patients with severe tropical malaria in the intensive care units of the University Hospital Zurich and the Stadtspital Triemli, Zurich, between 1991 and 1994. None of the 12 patients had been exposed to malaria before or had taken drugs for chemoprophylaxis. 7 patients survived, 5 died from complications of malaria. According to the criteria of severe tropical malaria defined by the WHO, the following pathological clinical and blood chemical parameters were noted on admission: cerebral coma (2/12); blood hemoglobin < 5 g/dl (0/12), < 8 g/dl (2/12); serum creatinine > 265 mumol/l (3/12); blood glucose < 2.2 mmol/l (0.12); circulatory collapse/shock (0/12); bleeding/signs of disseminated intravascular coagulation in laboratory tests (4/12); acidosis with pH < 7.25 (1/12). Further signs of severe tropical malaria were: hyperparasitemia > 5% (9/12); qualitative and quantitative disturbances of consciousness (6/12); thrombocytopenia < 30 x 10(9)/l (9/12); hyponatremia 125-135 mmol/l (9/12), < 125 mmol/l (2/12); rhabdomyolysis with creatine kinase > 1000 U/l (4/12). The basic treatment consisted of parenteral quinine hydrochloride in all patients; doxycycline was added in 8 cases, clindamycin in 3. Adjuvant therapy with desferrioxamin was given in 3 cases. 6 patients had exchange transfusions. Parasitemia cleared in all patients within 5 to 6 days. Later in the course, 5 patients developed acute respiratory distress syndrome, 6 required hemofiltration due to oliguria, and one became comatose.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Intensive care aspects in severe tropical malaria: clinical aspects, therapy and prognostic factors]. 777 Jul 59

We used thrombomodulin (TM) to assess the participation of the vascular endothelium in human Plasmodium falciparum (P.F.) malaria. Before therapy TM plasma levels were elevated in P.F. malaria and fell to normal values during therapy. Parasitemia, TNF alpha, elastase and TAT levels correlated directly with TM. Elevated TM levels can not be explained by increased synthesis, since incubating HUVEC with pretherapy serum of patients with P.F. malaria, but not reconvalescence serum, suppressed TM transcription. This was partially prevented by adding a TNF alpha neutralizing antibody to patient serum before incubation with HUVEC. However, TNF alpha does not release TM from cultured HUVEC in vitro. Coincubation of HUVEC with pretherapy serum together with neutrophils resulted in endothelial cell destruction, which could be partly prevented by a TNF alpha neutralizing antibody. Hence the increase of TM during P.F. malaria might reflect the concerted action of cytokines and neutrophils on HUVEC.
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PMID:Elevated thrombomodulin plasma levels as a result of endothelial involvement in plasmodium falciparum malaria. 785 98

Antibody responses to naturally acquired Plasmodium relictum and P. elongatum infections, blood parasitemia, and disease signs were investigated in 23 naive juvenile African black-footed penguins (Spheniscus demersus). Anti-Plasmodium spp. immunoglobulins were detected by enzyme-linked immunosorbent assay (ELISA) using P. falciparum antigens. All birds rapidly developed antibody to P. relictum and P. elongatum. Five penguins showed detectable parasitemia and signs of the disease. Parasitemia was not related to the timing of the maximal antibody response or to the antibody titer. Two of the five parasitemic birds died and gross examination revealed splenomegaly, hepatomegaly, and congested, edematous lungs. Although the other 17 birds were clearly exposed to the disease, none showed signs of infection. No subsequent episode of parasitemia was observed in individual penguins. A comparison of the fate of 1993 penguins with those from other years showed a great variability in the proportion of birds exhibiting signs of malaria.
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PMID:Characteristics of naturally acquired avian malaria infections in naive juvenile African black-footed penguins (Spheniscus demersus). 788 30

Clinical and experimental evidence suggests that iron-deficient hosts are less susceptible to severe malaria and that iron supplementation aggravates infection. In the present study, 60 weanling Wistar rats were fed standard diets with different iron concentrations: 21 mg/kg (group 1), 45 mg/kg (group 2) and 113 mg/kg (group 3). Ferrous sulfate (FeSO4 x 7H2O) was added to the normal-iron and iron-supplemented diets (groups 2 and 3, respectively). Data are reported as mean +/- SEM. After 16 days of regimen, eight rats from each group were killed to measure serum iron concentration (SI) and transferrin saturation capacity (TSC). At this moment, rats from group 1 were underweight and their dietary intake was significantly lower than that of animals from the other groups. Severe iron deficiency (SI = 49.2 +/- 4.5 micrograms/100 ml and TSC = 8.3 +/- 0.7%) was observed in rats from group 1, while the animals from the other groups were iron-sufficient (group 2: SI = 186.5 +/- 28.5 micrograms/100 ml and TSC = 27.3 +/- 3.4%; group 3: SI = 137.3 +/- 18.2 micrograms/100 ml and TSC = 21.3 +/- 2.3%). Nine animals from each group were then infected with the malaria parasite Plasmodium berghei, whereas three animals from each group were used as noninfected controls. Parasitemias (% of infected red blood cells) peaked 7 days post-infection in animals from groups 2 and 3 (mean values of 2.4% and 1.7%, respectively), but in animals from group 1 parasitemias increased until the 9th day post-infection (mean at peak, 2.3%) and parasite clearance was significantly slower than in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of dietary iron on the course of Plasmodium berghei malaria in young rats. 813 31

Fifty subjects with acute uncomplicated falciparum malaria were treated orally with a new micronized formulation of halofantrine. The dose given corresponded to one-half the normal dose for the standard formulation. Parasitemia cleared in all subjects within 78 h. There was recrudescence of falciparum malaria in seven subjects after day 14. The mean +/- standard deviation clearance times of parasitemia and fever were 49.0 +/- 14.2 and 24.3 +/- 13.2 h, respectively. Other clinical symptoms related to malaria cleared within the first 3 days. Pruritus occurred in two subjects, back pain occurred in one subject, and diarrhea occurred in one subject; all of these symptoms were mild. Hematological and biochemical indices were not adversely affected by treatment except in five subjects in whom minor and transitory increases in aspartate aminotransferase and alanine aminotransferase were observed. Micronized halofantrine appears to be a safe, well-tolerated, and effective treatment for acute falciparum malaria in semiimmune patients.
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PMID:Efficacy of micronized halofantrine in semi-immune patients with acute uncomplicated falciparum malaria in Cameroon. 823 11

Recombinant rat interferon-gamma (rrIFN-gamma) was tested for its antimalarial activity in three different models of Plasmodium chabaudi-blood stage malaria. Doses ranging from 1 x 10(4) to 1 x 10(5) U of rrIFN-gamma were used in each model. In BALB/c mice (lethal infection), prophylactic treatment with daily intraperitoneal (i.p.) injections reduced parasitemia and delayed mortality. In contrast, subcutaneous administration of rrIFN-gamma was inefficient, as was curative schedule of i.p. administration. Euthymic Fischer rats, which develop an acute and resolutive infection, were partly protected by i.p. prophylactic administration of rrIFN-gamma. Parasitemia was reduced without being lengthened, resulting in a marked decrease in parasite burden. Subcutaneous administration was less efficient whereas curative schedule was not. Athymic (nude) Fischer rats which present a longlasting and stable infection were treated with prophylactic and curative schedules of i.p. administration of rrIFN-gamma. In each case, rrIFN-gamma-treated nude rats, as control nude rats, were unable to resolve their chronic infection. The conditions required to obtain a beneficial effect are thus restrictive for a therapeutic use in humans. Moreover, these results show that, despite the fact that IFN-gamma is considered as a major component of the immune response, this cytokine alone is not sufficient to induce the totality of the effector mechanisms necessary to cure malarial infections.
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PMID:IFN-gamma treatment of rodents infected with erythrocytic stages of Plasmodium chabaudi: differential effects according to the immunological status. 850 41

In a region of Africa (Nord-Kivu, Zaire) where malaria is endemic, circulating malaria parasites, malaria-associated placental lesions, and a low hemoglobin level (< 10 g/dl) were observed, either singly or in combination, in 73.1% of women (n = 461) delivering at the maternity hospital. These pathologic findings were associated with low birthweight in 18.1% of the newborns, whereas the prevalence of low birthweight was 6.4% among cases without these findings (P < 0.05). Parasitemia was observed in 17.4% of all mothers and was associated with a significant decrease in birthweight. Malaria-associated lesions were found in 52.5% of all placentas and were associated with a decrease in birthweight, head circumference, and ponderal index of the newborns. Such lesions were more frequently observed among primiparae (60.5%) than among multiparae (49.5%; P < 0.05). Lastly, a low hemoglobin level, found in 38.6% of the mothers, was associated with a decrease in birthweight, length, and head circumference. The differences in the physical effects associated with each of the pathologic conditions suggest that parasitemia, placental lesions, and anemia result in acute, subacute, and chronic impairment of fetal growth, respectively. Moreover, their deleterious effects may be cumulative, since the most dramatically affected physical patterns were found when the pathologic findings were associated in the same patient. Frequent antenatal monitoring of maternal hemoglobin and parasitemia, accompanied, when necessary, with curative treatments, may help to reduce the prevalence of intrauterine growth retardation and its procession of perinatal complications.
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PMID:Gestational malaria: assessment of its consequences on fetal growth. 851 79

A triple-blind, randomized, clinical trial was undertaken in a Brazilian Amazon region to compare the effectiveness of oral artesunate (seven days, total dose = 0.75 g) plus tetracycline (seven days, total dose = 10.5 g) (AT) and oral quinine (three days, total dose = 6 g) plus tetracycline (seven days, total dose = 10.5 g) (QT) against uncomplicated Plasmodium falciparum malaria. Effectiveness was assessed by cure rates (World Health Organization [WHO]) and parasite clearance at day 2. Patients were randomized, 88 to each group. The groups had similar baseline clinical characteristics. The incidence of side effects was much higher in the QT group (82%) than in the AT group (50%) (P < 0.001). Cure rates were similar: 80% in the AT group and 77% in the QT group (P = 0.68). Parasitemia (by day 2) cleared faster in the AT group than in the QT group (98.5% versus 47.6%, respectively; P < 0.001). These results indicate that the combination of artesunate plus tetracycline is effective in the treatment of uncomplicated falciparum malaria and may provide a useful alternative to other treatment regimens.
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PMID:Randomized controlled trial of artesunate plus tetracycline versus standard treatment (quinine plus tetracycline) for uncomplicated Plasmodium falciparum malaria in Brazil. 861 47


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