Publications

stable transfection of malaria parasite blood stages.	genetic manipulation of malaria parasites would revolutionize the study of this group of pathogens and have implications for vaccine and drug development. this report describes the stable, drug-selectable genetic transformation of the clinically relevant intracellular blood stages of a malaria parasite. a plasmid transfection vector carrying the gene locus that encodes a drug-resistant form of the bifunctional enzyme dihydrofolate reductase-thymidylate synthase from the rodent malaria parasite p ...	1995	7761856
plasmodium berghei infection: dichloroacetate improves survival in rats with lactic acidosis.	the kinetics of plasmodium berghei infection and the development of lactic acidosis, hypoglycemia, and anemia were defined in young wistar rats. this model of metabolic dysfunction, which is similar to that of severe human malaria, was used to test the hypothesis that dichloroacetate, a treatment for lactic acidosis, prolonged survival in rats receiving a single antimalarial dose of quinine (20 mg/kg). rats with hyperlactatemia (lactate > 5 mmol/liter, n = 183) were randomized to receive either ...	1995	7758543
effect of a cecropin-like synthetic peptide (shiva-3) on the sporogonic development of plasmodium berghei.	the effect of a synthetic cecropin-like peptide, shiva-3, on in vitro ookinete development and on the early sporogonic stages of plasmodium berghei in the midgut of anopheles albimanus was investigated. peptide concentrations of 75 and 100 microm were effective (p < 0.05) in reducing ookinete production and the number of infected mosquitoes in almost all experiments. these peptide concentrations in the midgut were not toxic for the survival of the mosquitoes. complete inhibition was obtained if ...	1995	7758540
use of synthetic peptide libraries for the h-2kd binding motif identification.	to identify kd-binding peptides, an approach based on small peptide libraries has been developed. these peptide libraries correspond to all possible single-amino acid variants of a particular kd-binding peptide, syipsaeyi, an analog of the plasmodium berghei 252-260 antigenic peptide syipsaeki. in the parent sequence, each position is replaced by all the genetically encoded amino acids (except cysteine). the multiple analog syntheses are performed either by the divide couple and recombine method ...	1995	7756754
enhanced depletion of glutathione and increased liver oxidative damage in aflatoxin-fed mice infected with plasmodium berghei.	the effect of dietary aflatoxins b1 and g1 and plasmodium berghei infection on glutathione (gsh) levels and liver status in mice was investigated. three days after intraperitoneal injection of 0.1 x 10(6) parasitized red blood cells into the mice, there was a significant fall in blood glutathione levels accompanied by a significant increase in serum cholinesterase and liver malonic dialdehyde levels in the mice fed aflatoxin compared with those in the control group. the results suggested that ma ...	1995	7747309
conserved location of genes on polymorphic chromosomes of four species of malaria parasites.	the number of chromosomes and the chromosomal location and linkage of more than 50 probes, mainly of genes, have been established in four species of plasmodium which infect african murine rodents. we expected that the location and linkage of genes would not be conserved between these species of malaria parasites since extensive inter- and intraspecific size differences of the chromosomes existed and large scale internal rearrangements and chromosome translocations in parasites from laboratory li ...	1994	7739674
differential expression in blood stages of the gene coding for the 21-kilodalton surface protein of ookinetes of plasmodium berghei as detected by rna in situ hybridisation.	the developmentally regulated transcription of the gene encoding the ookinete surface protein, pbs21, has been investigated in the rodent malaria parasite, plasmodium berghei, by rna in situ hybridisation using fluorescently labelled dna probes. we used a procedure that will allow the visualisation of cytoplasmic mrna in the parasite and of high copy dna repeats in the nucleus. specific hybridisation to pbs21 mrna occurred in the cytoplasm of female gametocytes, zygotes and ookinetes, while asex ...	1994	7739671
in situ detection of pbs21 mrna during sexual development of plasmodium berghei.	the patterns of expression of ribosomal rna and mrna encoding the parasite surface antigen pbs21 have been investigated during the sexual stages of development of the malaria parasite, plasmodium berghei, using the technique of non-radioactive in situ rna hybridisation. an rna probe complementary to a region of the small subunit of p. berghei ribosomal rna hybridised to parasites at all stages of development in a smear of blood taken from mice infected with p. berghei. messenger rna encoding pbs ...	1994	7739665
cure with cisplatin (ii) or murine malaria infection and in vitro inhibition of a chloroquine-resistant plasmodium falciparum isolate.	antiplasmodium properties of cisplatin [cis-platinum (ii) diamine dichloride], a neoplastic drug, have been assessed in in vivo and in vitro model systems of malarial parasite. a well-tolerated dose of 6 mg/kg body weight of the compound cured the mice infected with plasmodium berghei and the amount of cisplatin required for in vitro inhibition (ic50) of a chloroquine-resistant plasmodium falciparum isolate was smaller than either chloroquine or quinine. the minimum inhibitory concentration (mic ...	1994	7739147
maintenance of protective immunity against malaria by persistent hepatic parasites derived from irradiated sporozoites.	immunization of rodents and humans with irradiation-attenuated malaria sporozoites confers preerythrocytic stage-specific protective immunity to challenge infection. this immunity is directed against intrahepatic parasites and involves t cells and interferon gamma, which prevent development of exoerythrocytic stages and subsequent blood infection. the present study was undertaken to determine how protective immunity is achieved after immunization of rodent hosts with irradiated plasmodium berghe ...	1995	7732032
long-term survival of plasmodium sporozoites in vitro.		1995	7731930
chaperonin-like repeats in a 34-kda plasmodium berghei phosphoprotein.		1995	7731926
the effect of chemical substitution on the metabolic activation, metabolic detoxication, and pharmacological activity of amodiaquine in the mouse.	the adverse reactions associated with the antimalarial amodiaquine (aq), agranulocytosis and hepatotoxicity, have been attributed to the bioactivation of the drug to a quinone imine metabolite. therefore the effect of chemical modification on the metabolism of aq was studied, with particular reference to the prevention of bioactivation and the introduction of glucuronidation. glutathione conjugates of aq and desethylaq were eliminated in bile after intraportal administration of [3h]aq (54 mumol/ ...	1995	7714794
chloroquine encapsulated in malaria-infected erythrocyte-specific antibody-bearing liposomes effectively controls chloroquine-resistant plasmodium berghei infections in mice.	the suitability of liposomes as drug carriers in the treatment of drug-resistant rodent malaria was examined after covalently attaching f(ab')2 fragments of a mouse monoclonal antibody (mab), mab f10, raised against the host cell membranes isolated from the plasmodium berghei-infected mouse erythrocytes, to the liposome surface. the antibody-bearing liposomes thus formed specifically recognized the p. berghei-infected mouse erythrocytes under both in vitro and in vivo conditions. no such specifi ...	1995	7695303
factors regulating natural transmission of plasmodium berghei to the mosquito vector, and the cloning of a transmission-blocking immunogen.	naturally occurring factors that regulate the infectivity of p. berghei infected rodent hosts to the mosquito vector in vivo have been compared in t.o., balb/c and immunodeficient scid mice. no detectable differences in infectivity were observed suggesting b and t cell mediated factors are not involved. further studies investigated roles for macrophage colony stimulating factors, the cytokines ifn gamma and tnf alpha, of neutrophils, and of nitric oxide in the scid mouse, but have failed to demo ...	1993	7694225
analysis of micronucleated cells by flow cytometry. 2. evaluating the accuracy of high-speed scoring.	micronucleated blood cells--whether generated spontaneously or by clastogen treatment--are present in the blood and bone marrow as rare events. historically they have been scored manually by microscopic inspection which is labor-intensive and tedious. it has been recognized by investigators that a need exists for an automated method which can accurately, objectively and quantitatively score rare micronucleated cells. in order to improve assay statistics more cells must be processed, making high- ...	1993	7692250
analysis of micronucleated cells by flow cytometry. 1. achieving high resolution with a malaria model.	micronucleated cells (mn cells) are present in the blood as rare events (i.e. about 2 mn cells/1000 total). scoring mn cells by hand is both time-consuming and tedious, which is the primary reason why only 1000-2000 total cells (pces) are routinely scored for each sample. it is generally recognized that scoring larger numbers of cells would improve assay statistics and is desirable, but impractical with hand-scoring. in contrast, automated scoring methods can process large numbers of cells, thus ...	1993	7692249
morphological changes of clefts in plasmodium-infected erythrocytes under adverse conditions.	blood infected with human or rodent malaria parasites, plasmodium falciparum or plasmodium berghei, was exposed to higher ph, higher po2, and lower temperature than those used in standard cultivation conditions. parasitized blood was incubated for 20, 25, and 30 min with rpmi 1640 medium, 10% (vol/vol) serum, ph 8.0, at 20 degrees c in the air, conditions which are ultimately lethal to the asexual stages of malarial parasites. markedly dilated clefts were observed in the cytoplasm of the malaria ...	1993	7684707
flow cytometric screening of blood samples for malaria parasites.	an automated method for the detection and estimation of malaria parasites in blood samples using flow cytometry is presented. in a single-step procedure 50 microliters of blood sample was collected in 1 ml of lysis solution containing formaldehyde, causing red blood cells to lyse while parasites and white blood cells are preserved. thus prepared, samples could be transported and remained stored in lysis solution until flow cytometric analysis was performed. the cells were stained for dna with th ...	1993	7682494
common epitopes in the circumsporozoite proteins of plasmodium berghei and plasmodium gallinaceum identified by monoclonal antibodies to the p. gallinaceum circumsporozoite protein.	monoclonal antibodies that react with the circumsporozoite protein of the avian malaria plasmodium gallinaceum sporozoites also reacted with circumsporozoite protein of the rodent malaria plasmodium berghei. two types of reactivity were identified: 1) two monoclonal antibodies reacted with p. berghei sporozoite protein by enzyme-linked immunosorbent assay, western blot and indirect immunofluorescence antibody, 2) six other monoclonal antibodies reacted with p. berghei sporozoites by elisa and we ...	1993	7681341
malaria vaccine: immunization of mice with a synthetic t cell helper epitope alone leads to protective immunity.	the immunogenicity of the non-repetitive sequences of the plasmodium berghei circumsporozoite (cs) protein was studied using synthetic peptides. two cs sequences (residues 20-39 and 57-70) exhibiting t cell helper activity were identified. immunization of balb/c mice with a branched peptide containing either the 20-39 or the 57-70 sequence and two repeats (b epitope) in a linear sequence induced high titers of anti-repeat and anti-sporozoite antibodies. mice immunized with the t-b construct (hig ...	1993	7679652
inhibition of plasmodium berghei liver schizont development and reduction of cytokine production capacity in rats by dietary fish oil supplementation.	experimental primary infection with plasmodium berghei in rats is known to be influenced by several cytokines. dietary supplementation of n-3 fatty acids has been shown to influence cytokine production capacity and to protect mice from cerebral malaria. we investigated the effect of dietary fish oil (fo) supplementation on cytokine and nitric oxide production and liver schizont development in male brown norway rats. control groups were fed either a corn oil-supplemented diet (co) or standard lab ...	1995	7677226
transgenic mice expressing high levels of soluble tnf-r1 fusion protein are protected from lethal septic shock and cerebral malaria, and are highly sensitive to listeria monocytogenes and leishmania major infections.	mice bearing a transgene coding for a soluble tumor necrosis factor receptor type 1 (tnfr1)-fcigg3 fusion protein and placed under the control of the alpha-1-antitrypsin gene promoter were generated. depending on the mouse line, blood levels of the protein ranged from 25 ng/ml to over 100 micrograms/ml; this level of expression was most often transmitted to the transgene-bearing progeny as a relatively stable feature. high-expressor mice were completely resistant to lipopolysaccharide-induced sh ...	1995	7664802
activities of extracts and naphthylisoquinoline alkaloids from triphyophyllum peltatum, ancistrocladus abbreviatus and ancistrocladus barteri against plasmodium berghei (anka strain) in vitro.	extracts from three tropical medicinal plant species belonging to the dioncophyllaceae (triphyophyllum peltatum) and the ancistrocladaceae (ancistrocladus abbreviatus and ancistrocladus barteri), and pure naphthylisoquinoline alkaloids derived from these species have been examined for the first time for their activity against asexual blood forms of plasmodium berghei (anka strain) in vitro. these activities were considerable and comparable with those earlier found against erythrocytic forms of p ...	1995	7650949
plasmodium berghei: selection of mefloquine-resistant parasites through drug pressure in mosquitoes.	mefloquine is an antimalarial drug with schizonticidal activity on blood-stage parasites. studies of the role of mefloquine on the development of plasmodium berghei anka in anopheles stephensi have been carried out that showed a dose-dependent effect on the sporogonic cycle of these parasites, with changes in the numbers of oocysts and the extent of sporozoite invasion of salivary glands. in this study, we show that mefloquine-resistant p. berghei anka blood stage parasites could be selected thr ...	1995	7628567
plasmodium berghei: implication of intracellular glutathione and its related enzyme in chloroquine resistance in vivo.	glutathione (gsh) plays a critical role in the detoxication and the protection of cells against oxidative stress. in the present study we examined the relationship between the intracellular gsh levels as well as glutathione s-transferase (gst), glutathione reductase (gr), and glutathione peroxidase (gpx) activities and how they relate to plasmodium berghei resistance to chloroquine. resistant strains (cqr30 and cqr60) were selected in vivo from a sensitive strain (nk65). marked increases in gsh ...	1995	7628559
expression of the plasmodium berghei ookinete protein pbs21 in a baculovirus-insect cell system produces an efficient transmission blocking immunogen.	a surface protein of plasmodium berghei ookinetes, pbs21, was expressed in a baculovirus-insect cell system in cell culture and in heliothis virescens larvae. groups of balb/c mice received two intraperitoneal inoculations of either i) tris-buffer or homogenized h. virescens larvae infected with wild-type baculovirus; ii) enriched, homogenized ookinetes, or iii) homogenized h. virescens larvae expressing recombinant pbs21 (rpbs21). all animals immunized with ookinetes or with rpbs21 had high tit ...	1995	7624157
status of hepatic glutathione-s-transferase(s) during plasmodium berghei infection and chloroquine treatment in mastomys natalensis.	plasmodium berghei infection in mastomys natalensis impaired the hepatic mitochondrial, microsomal and cytosolic glutathione-s-transferase(s) activity with 1-chloro-2,4-dinitrobenzene as substrate. the enzyme activity was concomitantly decreased with rise in parasitaemia. the decreased enzyme activity due to infection was almost normalized with oral treatment of 16 mg (kg body wt)-1 of chloroquine for 4 days.	1995	7622326
[casual influence of the stimulation of macrophage production by proteose-peptone, in the experimental infection of mice by plasmodium berghei].	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.	1994	7610336
efficient binding of reduced peptide bond pseudopeptides to major histocompatibility complex class i molecule.	reduced peptide bond pseudopeptide analogues have been examined for their ability to bind murine class i molecules of the major histocompatibility complex (mhc). eight pseudopeptide analogues of an antigenic peptide derived from plasmodium berghei (h-ser252-tyr-ile-pro-ser-ala-glu-lys-ile260-oh) were obtained by systematically replacing one peptide bond at a time by a reduced peptide bond psi (ch2-nh). the resulting analogues were then tested for their binding to a recombinant single chain sc-kd ...	1995	7592803
a conserved peptide sequence of the plasmodium falciparum circumsporozoite protein and antipeptide antibodies inhibit plasmodium berghei sporozoite invasion of hep-g2 cells and protect immunized mice against p. berghei sporozoite challenge.	minutes after injection into the circulation, malaria sporozoites enter hepatocytes. the speed and specificity of the invasion process suggest that it is receptor mediated. the region ii sequence of plasmodium falciparum circumsporozoite (cs) protein includes a nonapeptide (wspcsvtcg) which is highly conserved in all of the cs proteins sequenced to data, including the one from plasmodium berghei. we have found that two peptides based on the p. falciparum region ii sequence, p18 (ewspcsvtcgngiqvr ...	1995	7591073
cd8+ t-cell protective immunity induced by immunization with plasmodium berghei cs protein-derived synthetic peptides: evidence that localization of peptide-specific ctls is crucial for protection against malaria.	immunization of balb/c mice (h-2d) with a mixture of major histocompatibility complex (mhc) class i- and mhc class ii-restricted synthetic peptides emulsified in incomplete freund's adjuvant (ifa) induced a high level of specific cytotoxic t lymphocyte (ctl) activity. peptides 249-260 or 252-260, derived from the circumsporozoite protein of plasmodium berghei and representing a h-2kd-restricted ctl epitope, were injected twice subcutaneously or intraperitoneally in balb/c mice in combination wit ...	1995	7590920
cd8+ cell activation to a major mastocytoma rejection antigen, p815ab: requirement for tum- or helper peptides in priming for skin test reactivity to a p815ab-related peptide.	delayed-type hypersensitivity (dth) responses, mediated by cd8+ cells and detected by skin test assay, occur in sensitized mice in response to challenge with class i-restricted antigenic peptides of mutagenized (tum-) p815 mastocytoma cells. in contrast, a nonapeptide related to a tumor rejection antigen, p815ab, failed in this study to elicit dth after sensitization of mice with irradiated tumor cells or adoptive transfer of p815ab-pulsed dendritic cells. unresponsiveness, however, could be ove ...	1995	7589074
attempted isolation of the gene encoding the 21 kd plasmodium berghei ookinete transmission blocking antigen from plasmodium yoelli and plasmodium vivax.	the 21kd ookinete antigen of plasmodium berghei (pbs 21) has been shown to elicit an effective and long lasting transmission blocking immune response in mice. having cloned and sequenced this antigen (paton et al. 1993) the sequence was compared to the genes of the same family previously identified in p. falciparum, p. gallinaceum (kaslow et al. 1989) and p. reichenowi (lal et al. 1990). four conserved areas were identified in this comparison, to which degenerate oligonucleotides were designed. ...	1994	7565129
isolation of a distally located gene possibly correlated with gametocyte production ability.	previous studies were focussed on the attempt to correlate observable variations in the size of plasmodium berghei chromosomes with the loss of ability to produce viable gametocytes. a temporal coincidence between the appearance of a subtelomeric deletion on p. berghei chromosome 5 and the loss of the ability to produce viable gametocytes was observed in a clone (hpe) directly derived from the high gametocyte-producer clone 8417 during mechanical passages. interestingly enough, three p. berghei ...	1994	7565128
subtelomeric structure of plasmodium falciparum chromosomes.	previous studies of subtelomeric regions in plasmodium berghei led to the identification of subtelomeric repeats (2.3kb long) present in a variable number at many chromosomal ends. both loss and increase in 2.3kb-repeat copy number are involved in chromosome-size polymorphisms. subtelomeric losses leading to chromosome-size polymorphisms have been described by several authors in p.falciparum where the structure of subtelomeric regions is not known in detail. we therefore undertook their characte ...	1994	7565127
attenuated immunogenic parasites are essential in the transfer of immunity to virulent plasmodium berghei.	a less virulent parasite of plasmodium berghei k173 was isolated that induced immunity against the more virulent parasite. immunity to this parasite but not to the virulent one, could be transferred by immune spleen cells but not by immune lymph node cells. however, the immune spleen cells did transfer immunity to the virulent strain if accompanied by infection with viable parasites of the less virulent strain, but only if they were allowed to proliferate for a period of 1 week before challenge ...	1995	7558142
[relationship between tumour necrosis factor and anemia of malaria].	in this paper, the relation between the level of the reactive oxygen species (ros) and relevant free radicals in the blood plasma of the balb/c mice infected with plasmodium berghei anka strain and their erythrocytic deformability (ed), and the relation between the ed and the hb indices of these mice were studied by chemiluminescence (cl), induced cl (icl) and laser diffraction method. the results indicated that the ed decreased with the increase of the level of ros and free radicals in blood pl ...	1995	7554164
effect of mosquito age and reproductive status on melanization of sephadex beads in plasmodium-refractory and -susceptible strains of anopheles gambiae.	malaria-refractory and -susceptible strains of the mosquito vector, anopheles gambiae, differ in their response to negatively-charged sephadex cm-25 beads. cm-25 beads elicit a much stronger melanization reaction in refractory mosquitoes than in susceptible mosquitoes. light microscopic and scanning electron microscopic studies documented a progression from early stages with small spots of melanin adhering to cm-25 beads to late stages where spots had grown and coalesced to form a dark dense cap ...	1995	7544819
monopalmitic acid-peptide conjugates induce cytotoxic t cell responses against malarial epitopes: importance of spacer amino acids.	cytolytic t cells (ctl) play a critical role in providing protection against the liver stage of malaria infection. previous investigations have shown that induction of ctl against peptide or proteins can be achieved by attachment of lipids. in the present study, we used the plasmodium berghei circumsporozoite protein ctl epitope (syipsaeki (pl76)). this peptide with cysteine-serine (cs) as spacer amino acids was coupled to palmitic acid (pa). the same ctl epitope containing only an extra serine ...	1995	7540640
nitric oxide: cytokine-regulation of nitric oxide in host resistance to intracellular pathogens.	to discover how nitric oxide (no) synthesis is controlled in different tissues as cells within these tissues combat intracellular pathogens, we examined three distinctively different experimental murine models designed for studying parasite-host interactions: macrophage killing of leishmania major; nonspecific protection against tularemia (francisella tularensis) by mycobacterium bovis (bcg); and specific vaccine-induced protection against hepatic malaria with plasmodium berghei. each model para ...	1994	7537721
developmental changes in the circumsporozoite proteins of plasmodium berghei and p. gallinaceum in their mosquito vectors.	the circumsporozoite (cs) protein covers the surface of the sporozoite of plasmodia. its role in the development of the malaria parasite in mosquito vectors remains unknown. cs-epitope-containing proteins appear on undifferentiated oocysts on day 7 in plasmodium berghei and on day 5 in p. gallinaceum as demonstrated by indirect fluorescence antibody tests using monoclonal antibodies directed against the cs-protein repeats. the three-dimensional distribution of the cs-epitope-containing proteins ...	1995	7536921
co-localization of inducible-nitric oxide synthase and plasmodium berghei in hepatocytes from rats immunized with irradiated sporozoites.	both cd8+ t cells and ifn-gamma (ifn-gamma) are important components in the regulation of inducible-nitric oxide synthase (inos) which contribute to liver stage anti-malarial activity in rodents immunized with irradiated sporozoites. ifn-gamma, provided by malaria-specific cd8+ t cells, stimulates liver cells to produce nitric oxide (no) for the destruction of infected hepatocytes or the parasite within these cells. to identify the cell source of inos in livers from brown norway rats challenged ...	1995	7534796
flow cytometry in malaria detection.		1994	7533245
antibody-dependent neutrophil-mediated parasite killing in non-lethal rodent malaria.	the effects of administrating recombinant human granulocyte colony-stimulating factor (rhg-csf) and passively transferring immune serum on infection with an attenuated variant of plasmodium berghei xat (pb xat), in severe combined immunodeficiency (scid) mice were examined. in immune competent (c.b-17) mice, the attenuated parasite infection was inevitably self-resolving and degenerating forms inside erythrocytes appeared, coinciding with the drop in parasitaemia, whereas scid mice were unable t ...	1994	7532294
induction of nitric oxide synthase protects against malaria in mice exposed to irradiated plasmodium berghei infected mosquitoes: involvement of interferon gamma and cd8+ t cells.	exposure of balb/c mice to mosquitoes infected with irradiated plasmodium berghei confers protective immunity against subsequent sporozoite challenge. immunized mice challenged with viable sporozoites develop parasitemia when treated orally with substrate inhibitors of nitric oxide synthase (nos). this suggests that the production of nitric oxide (no) prevents the development of exoerythrocytic stages of malaria in liver. liver tissue from immunized mice expressed maximal levels of mrna for indu ...	1994	7516412
murine malaria: anti-erythrocytic antibodies recognize n-acetyl neuraminic acid residues.	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 in ...	1993	7508418
effect of recombinant human colony-stimulating factor on the course of parasitaemia in non-lethal rodent malaria.	the effect of repeated subcutaneous injections of recombinant human granulocyte colony-stimulating factor (rhg-csf) on the attenuated plasmodium berghei xat infection in cba mice was examined. when mice were injected with rhg-csf daily beginning 2 days before infection, the neutrophil count in the peripheral blood increased 5 times higher than that of control mice and the development of parasitaemia was suppressed significantly during the early phase of the infection. this suppressive effect of ...	1993	7507593
mhc class i h-2kd-restricted antigenic peptides: additional constraints for the binding motif.	the previously defined binding motif of mhc class i h-2kd-restricted antigenic peptides consists of a y residue in position p2 and a hydrophobic residue with a large aliphatic side chain (l, i, or v) in position p9/p10 of optimal 9- or 10-mer peptides. we show now that the presence of a charged or a f residue in position p5 reduces the kd-restricted competitor activity of several cytotoxic t lymphocyte (ctl) epitopes and model peptides, at a degree comparable to a substitutions for the p2 or the ...	1993	7505110
synthesis and biological activity of novel metal complexes of 2-acetylpyridine thiosemicarbazones.	2-acetylpyridine-(2-methylthiosemicarbazone), 2-acetylpyridine-(4-methylthiosemicarbazone), 2-acetylpyridine-(4-phenylthiosemicarbazone) and some of their metal complexes of the platinum group have been synthesized, characterized by chemical and spectral methods and studied for their antibacterial, antifungal and amoebicidal activity in vitro. they were studied also for their antimalarial activity and for toxicity in vivo. the platinum metal chelates exhibited significant activity against a wide ...	1995	7495474
decrease in platelet survival and total platelet sialic acid concentration in rats infected with plasmodium bergei bergei.	suckling wistar rats aged 3-5 weeks were infected through their dorsal tail vein with p. berghei berghei passed in swiss albino mice. platelet recovery and platelet survival using 51cr-labelled heterologous platelets obtained from adult wistar rats were determined in the infected animals on different post-infection days and on a group of non-infected rats as controls. total platelet sialic acid was also determined in the same groups of animals. the results showed reduced platelet recovery, short ...	1995	7495199
synthesis of potential inhibitors of hypoxanthine-guaine phosphoribosyltransferase for testing as antiprotozoal agents. 2. 1-substituted hypoxanthines.	evidence incicating that effective in vivo inhibition of hypoxanthine-guanine phosphoribosyltransferase (hgprt, ec 2.4.2.8) should produce antiprotozoal activity without significant toxic effects on mammalian hosts prompted syntheses of 1-substituted hypoxanthines bearing functionalized side chains whose groupings might interact with appropriate groupings of hgprt to form covalent bonds or strong hydrophobic bonds. 3-(fluorosulfonyl)benzoyl, 4-(fluorosulfonyl)benzoyl, 4-chlorobenzoyl, and bromac ...	1980	7420359
folate antagonists. 19. synthesis and antimalarial effects of 6-(arylthio)-2,4-pteridinediamines.	a series of 6-(arylthio)-2,4-pteridinediamines (iiia) was prepared by allowing 6-chloro-2,4-pteridinediamine to react with the requisite benzenethiols in dimethyl sulfone at 190-200 degrees c. attempts at oxidation to the corresponding sulfoxide (iiib) or sulfone (iiic) were unsuccessful. the compounds exhibited a spectrum of antibacterial activity similar to, but below the potency of, the related quinazolinediamines and pteridinediamines. unlike these related types, however, they were devoid of ...	1981	7328591
synthesis and antimalarial activity of 8-[(1-alkyl-4-aminobutyl)amino]-6-methoxy-4-methylquinolines.	three analogues of the causal prophylactic antimalarial primaquine were prepared and their antimalarial activity was evaluated. 8-[(1-ethyl-4-aminobutyl)amino]-6-methoxy-4-methylquinoline (2a) demonstrated activity against plasmodium berghei in mice at 20 mg/kg, with all animals cured at 320 mg/kg, and is without toxicity at 640 mg/kg. it also possessed outstanding causal prophylactic activity against plasmodium cynomolgi in rhesus monkeys at very low dosages.	1981	7205891
monoclonal antibodies that protect in vivo against plasmodium chabaudi recognize a 250,000-dalton parasite polypeptide.	twenty monoclonal antibodies have been prepared to the erythrocytes from cba/ca mice infected with the rodent malaria plasmodium chabaudi. by immunofluorescence, 15 of these antibodies recognized parasite antigens expressed only during the development of mature trophozoites to schizonts and merozoites, 2 recognized parasite antigens that were expressed throughout most of the intraerythrocytic cycle, and 3 recognized the membranes of all infected and uninfected erythrocytes. by immunoprecipitatio ...	1982	7141700
antimalarials. 14. 5-(aryloxy)-4-methylprimaquine analogues. a highly effective series of blood and tissue schizonticidal agents.	a series of five 5-(aryloxy)-4-methylprimaquine analogues has been prepared and evaluated for antimalarial activity. the compounds were tested for suppressive activity against plasmodium berghei in mice and for radical curative activity against plasmodium cynomolgi in the rhesus monkey. the compounds were not only significantly superior to primaquine as radical curative agents but also were suprisingly highly effective as suppressive agents.	1982	7131488
surface membrane proteins and glycoproteins of red blood cells from normal and anaemic mice.	1. the surface membrane proteins of red blood cells from normal, hyperbled or acetylphenylhydrazine-treated balb/c mice and nzb mice of different ages were labelled by lactoperoxidase-catalyzed radioiodination. sialoglyoproteins were labelled by periodate/nab3h4 or galactose oxidase +/- neuraminidase/na3h4 treatments. 2. anaemia produced several changes in radioiodinated proteins. 3. sialoglycoprotein radiolabelling was unchanged, even with over 90% reticulocytosis. 4. decreased periodate/nab3h4 ...	1982	7083822
metabolism of babesia parasites in vitro. amino acid production by babesia rodhaini compared to plasmodium berghei.	the in vitro amino acid production by babesia rodhaini, plasmodium berghei and uninfected rat erythrocytes was determined following 4 and 18 h of incubation in krebs ringer medium. both parasites produced excess free amino acid. b. rodhaini produced up to 150 times and p. berghei up to 1,100 times as much free amino acid as parasite-free rat erythrocytes. the composition of excess amino acids produced by both parasites had a statistically significant concordance with the amino acid composition o ...	1982	7052039
culture of the exoerythrocytic liver stages of plasmodium berghei sporozoites in rat hepatocytes.		1982	7051460
cerebral malaria in inbred mice. i. a new model and its pathology.	plasmodium berghei anka was tested for its usefulness as a model for cerebral malaria in inbred mouse strains a, a2g, a/j, c57l, sjl/j and swr. a suitable model was obtained in a or a/j strain mice. mortality was 100% after five to eight days with brain haemorrhages occurring terminally. the histopathology is described. the model was stable after six blood passages at 5- to 7-day intervals. chloroquine abolished the haemorrhages and no intercurrent viral or blood protozoal infections were detect ...	1982	7051459
resistance to superinfection with plasmodium berghei in rats fed a protein-free diet.	the development of resistance to reinfection with plasmodium berghei was studied in rats in which the primary infection had been almost totally suppressed by feeding a protein-free diet (peak parasitaemia 0.5%; patent for only the first four days after inoculation) on days 5, 9, 15, 23 and 28 after primary inoculation groups of animals were challenged with the same strain of parasite. at the same time the diet was changed to that of a 17% casein formula. the development of resistance as judged b ...	1982	7051455
mosquito infectivity is directly related to the proportion of repetitive dna in plasmodium berghei.	a strain of plasmodium berghei (nk 65) was followed during syringe transmission in mice for over 120 passages after the last complete cycle, while the following parameters were monitored: (a) capacity to infect mosquitoes, inducing oocyst formation; (b) presence in the peripheral blood of morphologically identifiable gametocytes; (c) presence of a repetitive component in the dna extracted from intraerythrocytic population. the suggestion of a possible role of this component in gametogenesis came ...	1982	7050700
the present status of malaria chemotherapy: mefloquine, a novel antimalarial.		1981	7050565
asynchronous maturation of plasmodium berghei exo-erythrocytic forms in rats.	sporozoites of plasmodium berghei berghei (nk-65 strain) were inoculated intravenously into four-week-old cfn rats. liver biopsies were taken at intervals and the density of exo-erythrocytic forms per mm3 of liver were estimated. results demonstrated asynchronous maturation and the gradual disappearance of exo-erythrocytic forms during the period 48 to 72 hours after infection.	1982	7048651
enhanced resistance to plasmodium berghei in mice previously infected with trichinella spiralis.	infection with trichinella spiralis larvae greatly enhanced the resistance of adult mice against fatal infection with plasmodium berghei given 10 and 30 days after t. spiralis infection. mice infected with t. spiralis had a markedly activated mononuclear phagocytic system and significantly low reticulocyte levels at the time the mice were challenged with p. berghei. therefore, the partially subdued parasitaemia and prolonged survival of trichinella-plasmodium-infected mice may be attributed, in ...	1982	7048209
adoptive transfer of resistance to plasmodium berghei with spleen cells and serum from fansidar-cured mice.	the ability of splenic leukocytes or serum to transfer immunity to plasmodium berghei was studied in c57bl/6 mice. splenic leukocytes or serum was removed from mice which had been inoculated previously 1 to 4 or 5 times with p. berghei and cured 1 to 4 or 5 times with fansidar (pyrimethamine plus sulfadoxine) and transferred to syngeneic recipients 1 or 2 days before parasite challenge. partial protection was observed in recipients of immune serum or unfractionated splenic leukocytes. significan ...	1982	7047391
heterogeneity in filterability of erythrocytes from malaria (plasmodium berghei)-infected blood.	erythrocytes from plasmodium berghei-infected blood show a decrease in deformability with increasing parasitaemia, as measured by filterability through polycarbonate sieves. a major fraction of cells carrying mature parasites and a smaller fraction carrying ring-stage parasites account for the obstruction of filtration, while the remaining infected cells do not contribute to the decrease in filterability. the relation of filterability to metabolic status in infected cells is discussed.	1982	7047205
the course of plasmodium berghei infection in mice latently infected with toxoplasma gondii.	the course of infection with 2 different virulent strains of plasmodium berghei was investigated in mice latently infected with toxoplasma gondii. when given the highly virulent anka strain of p. berghei all toxoplasma-infected mice died but the survival time was prolonged. after infection with the less virulent strain k 173 mice could survive the subsequent infection. in these cases levels of parasitemia depended upon the duration of the t. gondii infection. mice infected for about 6 weeks with ...	1982	7047202
cross-reactivity and cross-protection in murine malaria.		1982	7046657
[inflammation and resistance of mice against "plasmodium berghei" (author's transl)].	an inflammatory reaction induced in mice by a subcutaneous injection of magnesium silicate embedded in a calcium phosphate gel is followed by an increased resistance against plasmodium berghei. the occurrence of this increased resistance against plasmodium berghei. the occurrence of this increased resistance is related to the time elapsed between the induction of the inflammatory process and the infection. the delayed mortality is correlated with a slowed development of parasitemia. it is hypoth ...	1982	7046621
[malaria in the municipality of humaitá, state of amazonas. v - serological aspects of plasmodium falciparum and plasmodium berghei antigens].		1981	7046014
[malaria in the municipality of humaitá, state of amazonas, iv - seroepidemiological aspects of plasmodium berghei antigen].		1981	7046013
effects of malaria (plasmodium berghei) on the maternal-fetal relationship in mice.	plasmodium berghei infection was more severe in pregnant than in nonpregnant mice. infection initiated on gestation day 7 resulted in rapidly increasing parasitemia and deaths of all pregnant mice within 12 days, while some nonpregnant mice survived until day 21 postinfection. when mice were infected on gestation day 12 or 14, a proportion of mice died before parturition; but some animals survived to deliver living pups. reduced birthweights and increased spleen weight to body weight ratios were ...	1982	7045348
corticosterone regulation of the effector function of malarial immunity during pregnancy.	in the experimental plasmodium berghei mouse model, as in human malaria, reduced maternal responsiveness and even loss of immunity were observed during pregnancy. loss of immunity in the second half of pregnancy occurred during a period of elevated plasma corticoid levels. further analysis showed that plasma corticoid levels were significantly higher in immunodepressed mice than in mice that remained immune throughout pregnancy. plasma corticosterone levels differed increasingly from those in mi ...	1982	7044972
plasmodium berghei: isolation and maintenance of an irradiation attenuated strain in the nude mouse.		1982	7044811
[immunostimulating properties of an extract isolated from aloe vahombe. 2. protection in mice by fraction f1 against infections by listeria monocytogenes, yersinia pestis, candida albicans and plasmodium berghei].	a partially purified extract of leaves of aloe vahombe, a plant endemic in the south of madagascar, administered intravenously to mice, protects them against infection of bacteria (listeria monocytogenes, yersinia pestis), parasites (plasmodium berghei) and fungus (candida albicans). the protective fraction must be administered two days before inoculation of the pathogenic agent. these results significantly confirm those we obtained in earlier study on mice infection by klebsiella pneumoniae. cu ...	1981	7044327
the antimalarial activity of n-benzyl-oxydihydrotriazines. iv. the development of resistance to brl 6231 (4,6-diamino-1,2-dihyydro-2-,2-dimethyl-1-(2,4,5-trichloropropyloxy)-1,3,5 triazine hydrochloride) by plasmodium berghei.		1982	7044325
the antimalarial activity of n-benzyl-oxydihydrotriazines. iii. the activity of 4,6-diamino-1,2-dihydro-2,2-dimethyl-1-(2,4,5,-trichloropropyloxy)-1,3,5-triazine hydrobromide (brl 51084) and hydrochloride (brl 6231).		1982	7044322
aspects of immunosuppression during plasmodium berghei infection in rats.	depression in immunological responsiveness was manifested in phase with parasitaemia in rats infected with plasmodium berghei. the spleen was the most affected organ. the response of spleen cells to phytohaemagglutinin (pha) and the number of plaque forming cells among spleen cells of rats injected with sheep red blood cells (srbc), were reduced especially at peak parasitaemia. at the onset of the disease the spleen was activated and the responses were amplified. antibody titres in the serum rev ...	1981	7043823
comparative studies on the immunogenicity of infective and attenuated sporozoites of plasmodium berghei.		1982	7043807
correlation between susceptibility to malaria and babesia parasites and to endotoxicity.	adult (185g) rats are about twice as sensitive to the harmful effects of injected endotoxin as are younger (65g) rats. this relationship correlates with an earlier report on the densities of plasmodium berghei at which deaths occur in rats of these two age groups. similarly lizards, which withstand very high parasitaemias of malaria parasites, are refractory to very large doses of endotoxin. this correlation appears to hold for malaria and babesiosis in all host species for which information is ...	1982	7043806
superoxide dismutase (sod) in mouse red blood cells infected with plasmodium berghei.		1982	7042950
infectivity of in vitro-formed plasmodium berghei ookinetes to mosquitoes.		1982	7042949
inhibition of antibody-binding as a radioimmunoassay for plasmodium berghei infection in rats.	sonicated red blood cells of rats infected with plasmodium berghei (pb) were used to coat plastic tubes, which were subsequently tested for capacity to bind anti-p, berghei antibodies. binding was detected using radioiodinated staphylococcus protein a. two antigenic preparations were used to make the solid-phase adsorbent (and also as inhibitors in the inhibition tests): sonicated red blood cells (sirc), and a supernate of frozen-thawed, infected red blood cells (fte). treatment of the antigen-c ...	1982	7042946
lymphocyte traffic and lymphocyte destruction in murine malaria.	normal lymphocytes labelled with 51cr were injected into mice at various stages of lethal and non-lethal malaria infections. marked alterations were seen in the uptake into spleen and liver, which correlated with the outcome of the infection. non-lethal infections and lethal infections in mice protected by vaccination caused increased uptakes, especially in the liver. in lethal infections, particularly plasmodium berghei, uptakes were below normal values at certain times: this was apparently due ...	1982	7042547
antimalarial activity of cyclosporin a.	cyclosporin a has been shown to possess antimalarial activity in mice infected with plasmodium berghei nk 65 or plasmodium chabaudi. significant antimalarial effects were obtained with five daily oral doses of 25 mg/kg. cyclosporin a treatment started concurrently with the inoculation of parasites was less effective than treatment started when parasitaemia was already established. evidence so far suggests that the antimalarial action results from a direct toxic effect on the parasite. combined t ...	1981	7041571
chronic, patent plasmodium berghei malaria in splenectomized mice.	it was shown that splenectomized mice could develop a certain resistance to plasmodium berghei but usually no real immunity, since the infection became chronic, often with high parasitemias. a patent infection lasting at least 2 weeks was necessary for the development of this degree of protection. prolonged suppression to subpatent levels (sulfonamide treatment), rather than radical cure (chloroquine), after 2 weeks of patency yielded a higher proportion of mice resistant to superinfection. an i ...	1982	7040249
cellular and humoral immune responses in rats experimentally infected with plasmodium berghei.		1981	7040220
identification of a schizont- and species-specific surface glycoprotein on erythrocytes infected with rodent malarias.	erythrocytes infected with mature trophozoites of plasmodium chabaudi and reticulocytes infected with p. berghei were labelled metabolically in vitro with [35s]methionine. the labelled cells were incubated with normal and immune serum and washed to remove unbound antibody. solubilisation of the antibody-coated cells in detergent was followed by co-precipitation of antibody/antigen complexes and analysis of the immunoprecipitates by sds-page and fluorography. one major parasite polypeptide of 250 ...	1982	7038481
isolation and characterisation of ribosomal rna from the human malaria parasite plasmodium falciparum.	ribosomal rna isolated from the malaria parasite plasmodium falciparum consists of two species with molecular weight of 1.49 +/- 0.09 x 10(6) and 0.78 +/- 0.02 x 10(6) present in equimolar quantities. their molecular weights are comparable with those of other protozoa but quite distinct from those of the human host. the overall base composition of the rrna (40% g+c) is close to that of the rodent parasite plasmodium berghei, unlike the latter, however, p. falciparum has no nick in the rna from i ...	1981	7038480
mesangial disposal of glomerular immune deposits in acute malarial glomerulonephritis of rats.	the disposal of immune complexes by the glomerulus and the participation of infiltrating monocytes were studied in acute malaria-associated glomerulonephritis. young sprague-dawley rats were infected with plasmodium berghei. parasitemia reached a maximum after 8 to 12 days, ending by day 20. in all infected rats, renal immunofluorescence microscopy showed in all glomeruli granular deposition of rat igg, igm, and c3 in a mesangial distribution. the staining was strongest from days 8 to 12, then d ...	1982	7038293
antibodies to the protective antigen of plasmodium berghei sporozoites prevent entry into cultured cells.		1982	7037957
plasmodium berghei: architectural analysis by freeze-fracturing of the intraoocyst sporozoite's pellicular system.		1982	7037440
intraerythrocytic plasmodial calcium metabolism.		1981	7036992
plasmodium berghei exoerythrocytic forms develop only in the liver.		1981	7036442
the binding of antibodies from plasmodium berghei-infected rats to isoantigenic and parasite-specific antigenic sites on the surfaces of infected reticulocytes.	ferritin-labelling techniques at the ultrastructural level have shown that antiserum from august rats immune to p. berghei infection contains antibodies which bind to the surfaces of parasitized reticulocytes but not to uninfected cells. two antibody specificities have been demonstrated by comparing antisera i absorbed with infected reticulocytes, ii absorbed with uninfected reticulocytes, and iii unabsorbed. ferritin labeling was much increased with antiserum preabsorbed with uninfected reticul ...	1982	7036051
syntheses of 9-acridine- and 2-phenanthridinemethanols as potential antimalarials.	alpha-(1-piperidinylmethyl)-9-acridinemethanol (3), alpha-[(dibutylamino)ethyl]-9-acridanmethanol (4a), and alpha-[(dibutylamino)methyl]-2-phenanthridinemethanol (5) have been made and all are ineffective as antimalarials against plasmodium berghei in mice. 9-acridinyloxirane showed no significant mutagenicity for strains ta 98 or ta 100 of salmonella typhimurium.	1981	7035667
role of a serum factor in enhancement of in vitro interactions between plasmodium berghei sporozoites and hamster peritoneal macrophages.	interactions between plasmodium berghei sporozoites and hamster peritoneal macrophages were studied. hamster serum was shown to enhance the percentage of sporozoites tha attached to macrophages, thus confirming previous studies by other workers using mouse macrophages and mouse serum. the enhancement factor within hamster serum was concentrated by a fractionation procedure consisting of ammonium sulfate precipitation followed by concanavalin a-sepharose affinity chromatography. this serum fracti ...	1981	7035641
[morphological incidences of plasmodium berghei preference for reticulocytes (author's transl)].		1981	7034621
dietary suppression of rodent malaria.		1981	7034320