Publications

"one-pot" synthesis and antimalarial activity of formamidine derivatives of 4-anilinoquinoline.	amodiaquine (aq) is an antimalarial which is effective against chloroquino-resistant strains of plasmodium falciparum but whose clinical use is severely restricted because of associated hepatotoxicity and agranulocytosis. "one-pot" synthesis of formamidines likely to be transformed into aq derivatives is reported. compared with aq, the new compounds were devoid of in vitro cytotoxicity upon human embryonic lung cells and mouse peritoneal macrophages. one showed a potent in vivo activity in mice ...	2001	11515580
superoxide-dependent and -independent pathways are involved in the transmission blocking of malaria.	superoxide plays a crucial role in innate immunity to various pathogens. we examined the role of superoxides in the transmission of malaria using gp91phox knockout (x-cgd) mice that lack the ability to produce superoxide. mosquitoes that fed on x-cgd mice infected intraperitoneally with plasmodium berghei nk65 anka formed more oocysts than did those that fed on control mice at any day after infection. the number of oocysts peaked on day 5 post-infection in x-cgd and control mice and then decreas ...	2001	11510994
synthesis and in vitro and in vivo antimalarial activity of new 4-anilinoquinolines.	a new series of 4-anilinoquinolines with two proton-accepting side chains has been synthesized. antimalarial activity and levels of cytotoxicity upon both mrc-5 cells and macrophages were found to be highly dependent upon the features of these side chains. several compounds were found to be active in the low nanomolar range, against both chloroquine-sensitive and -resistant strains of plasmodium falciparum in vitro. from among them, a morpholino derivative cured mice infected by plasmodium bergh ...	2001	11495593
role of cd40-cvd40l in mouse severe malaria.	we explored the role of cd40-cd40l (cd154) in the severe malaria elicited by plasmodium berghei anka infection in mice. mortality was >90% by day 8 after infection in +/+ mice, but markedly decreased in cd40-/- or in cd40l-/- mice, as well as in +/+ mice treated with anti-cd40l monoclonal antibody. parasitemia was similar in the different conditions. breakdown of the blood-brain barrier was evident in infected +/+, but not in cd40-/- mice. thrombocytopenia was less severe in cd40-/- mice than in ...	2001	11485931
p25 and p28 proteins of the malaria ookinete surface have multiple and partially redundant functions.	the ookinete surface proteins (p25 and p28) are proven antimalarial transmission-blocking vaccine targets, yet their biological functions are unknown. by using single (sko) and double gene knock-out (dko) plasmodium berghei parasites, we show that p25 and p28 share multiple functions during ookinete/oocyst development. in the midgut of mosquitoes, the formation of ookinetes lacking both proteins (dko parasites) is significantly inhibited due to decreased protection against lethal factors, includ ...	2001	11483501
a search for natural bioactive compounds in bolivia through a multidisciplinary approach. part v. evaluation of the antimalarial activity of plants used by the tacana indians.	one hundred and twenty-five extracts of 122 different plant species traditionally used by the tacana, a native community living in lowland forest at the base of the last foothills of the cordillera oriental of the bolivian andes, were screened for antimalarial activity in vitro on plasmodium falciparum chloroquine resistant (d2) and sensitive strains (f32), and were evaluated in vivo on rodent malaria plasmodium berghei. five ethanolic stembark extracts showed marked activity either in vitro or ...	2001	11483383
antimalarial in-vivo activity of bis(9-amino-6-chloro-2-methoxyacridines).	in the fight against malaria, chemotherapy using bisacridines may represent an alternative method to overcoming chloroquine-resistance. eight bis(9-amino-6-chloro-2-methoxyacridines), in which acridine moieties were linked by polyamines substituted with a side chain, were tested for their in-vivo activity upon mice infected by plasmodium berghei. three of the compounds revealed antimalarial activity but no relationship could be deduced from a comparison of in-vitro and in-vivo activities. n-alky ...	2001	11480542
flow cytometric enumeration of micronucleated reticulocytes: high transferability among 14 laboratories.	this laboratory previously described a single-laser flow cytometric method, which effectively resolves micronucleated erythrocyte populations in rodent peripheral blood samples. even so, the rarity and variable size of micronuclei make it difficult to configure instrument settings consistently and define analysis regions rationally to enumerate the cell populations of interest. murine erythrocytes from animals infected with the malaria parasite plasmodium berghei contain a high prevalence of ery ...	2001	11473389
ctl activation is induced by cross-linking of tcr/mhc-peptide-cd8/p56lck adducts in rafts.	to investigate the role of the coreceptor cd8 and lipid rafts in cytotoxic t lymphocyte (ctl) activation, we used soluble mono-and multimeric h-2kd-peptide complexes and cloned s14 ctl specific for a photoreactive derivative of the plasmodium berghei circumsporozoite (pbcs) peptide 252-260 [pbcs(aba)]. we report that activation of ctl in suspension requires multimeric kd-pbcs(aba) complexes co-engaging tcr and cd8. using tcr ligand photo-cross-linking, we find that monomeric kd-pbcs(aba) complex ...	2001	11465114
von willebrand factor a domain-related protein, a novel microneme protein of the malaria ookinete highly conserved throughout plasmodium parasites.	the mosquito-invasive form of the malarial parasite, the ookinete, develops numerous secretory organelles, called micronemes, in the apical cytoplasm. micronemal proteins are thought to be secreted during midgut invasion and to play a crucial role in attachment and motility of the ookinete. we found a novel ookinete micronemal protein of rodent malarial parasite plasmodium berghei, named p. berghei von willebrand factor a domain-related protein (pbwarp), and report it here as a putative soluble ...	2001	11463467
potentiation by a novel alkaloid glycoside adjuvant of a protective cytotoxic t cell immune response specific for a preerythrocytic malaria vaccine candidate antigen.	we have recently demonstrated that the novel glycoalkaloid tomatine, derived from leaves of the wild tomato lycopersicon pimpinellifolium, can act as a powerful adjuvant for the elicitation of antigen-specific cd8+ t cell responses. here, we have extended our previous investigation with the model antigen ovalbumin to an established malaria infection system in mice and evaluated the cellular immune response to a major preerythrocytic stage malaria vaccine candidate antigen when administered with ...	2001	11457540
interaction between host complement and mosquito-midgut-stage plasmodium berghei.	after ingestion by mosquitoes, gametocytes of malaria parasites become activated and form extracellular gametes that are no longer protected by the red blood cell membrane against immune effectors of host blood. we have studied the action of complement on plasmodium developmental stages in the mosquito blood meal using the rodent malaria parasite plasmodium berghei and rat complement as a model. we have shown that in the mosquito midgut, rat complement components necessary to initiate the altern ...	2001	11447187
cytokine and chemokine mrna expression in neutrophils from cba/nslc mice infected with plasmodium berghei anka that induces experimental cerebral malaria.	to investigate the role of neutrophils in experimental cerebral malaria (ecm), in a previous study we found that early neutrophil depletion prevented the development of ecm and down regulated the expression of th1 cytokines in the brain. to further clarify the mechanisms responsible for these findings, in the present study, using rt-pcr, we examined the expression of cytokine and chemokine mrnas in neutrophils and macrophages after pba infection. we found that, after infection, neutrophils not o ...	2001	11438437
changes in rodent-erythrocyte methemoglobin reductase system produced by two malaria parasites, viz. plasmodium yoelii nigeriensis and plasmodium berghei.	the methemoglobin reductase system plays a vital role in maintaining the equilibrium between hemoglobin and methemoglobin in blood. exposure of red blood cells to oxidative stress (pathological/physiological) may cause impairment to this equilibrium. we studied the status of erythrocytic methemoglobin and the related reductase system during plasmodium yoelii nigeriensis infection in mice and p. berghei infection in mastomys. malaria infection was induced by intraperitoneal inoculation with 10(6) ...	2001	11435127
synthesis and antimalarial activity of novel medium-sized 1,2,4,5-tetraoxacycloalkanes.	csoh- or ag(2)o-mediated cycloalkylation of (alkylidene)bisperoxides 3 and 1,n-dihaloalkanes (n = 3-8) provided the corresponding medium-sized 1,2,4,5-tetraoxacycloalkanes 4-8 in moderate yields. subsequent evaluation of the antimalarial activity of the cyclic peroxides 4-8 in vitro and in vivo revealed that 1,2,6,7-tetraoxaspiro[7.11]nonadecane 4a has considerable potential as a new, inexpensive, and potent antimalarial drug.	2001	11428929
penetration of erythrocytes by merozoites of mammalian and avian malarial parasites. 1969.		2001	11426708
fluorescent plasmodium berghei sporozoites and pre-erythrocytic stages: a new tool to study mosquito and mammalian host interactions with malaria parasites.	to track malaria parasites for biological studies within the mosquito and mammalian hosts, we constructed a stably transformed clonal line of plasmodium berghei, pbfluspo, in which sporogonic and pre-erythrocytic liver-stage parasites are autonomously fluorescent. a cassette containing the structural gene for the facs-adapted green fluorescent protein mutant 2 (gfpmut2), expressed from the 5' and 3' flanking sequences of the circumsporozoite (cs) protein gene, was integrated and expressed at the ...	2001	11422080
16alpha-bromoepiandrosterone, a dehydroepiandrosterone (dhea) analogue, inhibits plasmodium falciparum and plasmodium berghei growth.	dehydroepiandrosterone (dhea) and its analogue, 16alpha-bromoepiandrosterone (alpha-epi-br), may have activity against viral and parasitic infections, including human immunodeficiency virus (hiv) and cryptosporidium parvum. therefore, we evaluated its antimalarial effects on plasmodium falciparum and plasmodium berghei. in vitro, chloroquine (cq)-sensitive and resistant strains of p. falciparum parasitized red blood cells were incubated with escalating doses of alpha-epi-br or cq. in vivo, 62 ra ...	2000	11421378
down-regulation of il-12 p40 gene in plasmodium berghei-infected mice.	we analyzed the mechanism that causes suppression of il-12 p40 gene induction during plasmodium berghei infection. although il-12 together with ifn-gamma plays an important role in protection against pathogenic infection, the il-12 p70 protein production of infected macrophages is lower than that by the uninfected macrophages. we showed in the present study that the induction of il-12 p40 gene but not il-12 p35 gene in macrophages of p. berghei-infected mice was profoundly inhibited. the inhibit ...	2001	11418654
(31)p nmr of apicomplexans and the effects of risedronate on cryptosporidium parvum growth.	high-resolution 303.6 mhz (31)p nmr spectra have been obtained of perchloric acid extracts of plasmodium berghei trophozoites, toxoplasma gondii tachyzoites, and cryptosporidium parvum oocysts. essentially complete resonance assignments have been made based on chemical shifts and by coaddition of authentic reference compounds. signals corresponding to inorganic pyrophosphate were detected in all three species. in t. gondii and c. parvum, additional resonances were observed corresponding to linea ...	2001	11396947
[experimental infection in mice by plasmodium berghei: an evidence of antiparasitic action of azithromycin].	infections of plasmodium berghei in mice was stopped by azithromycin which was administered orally in dosages of 100mg/kg, for 28 days. this antibiotic was given since the same day that the animals were infected. the outcome suggests the necessity of more investigations on this antiparasitic activity.	2001	11391444
short report: failure to select for chloroquine- or mefloquine-resistant plasmodium berghei through drug pressure in anopheles stephensi mosquitoes.	we investigated whether chloroquine- or mefloquine-resistant plasmodium berghei could be selected through drug pressure applied during continuous cyclical transmission in anopheles stephensi mosquitoes. mosquitoes were infected by feeding them on mice previously inoculated with a drug-sensitive clone of p. berghei anka. mosquitoes ingested mefloquine or chloroquine with the infectious blood-meal, or by feeding on a drug-treated (uninfected) mouse 4 or 10 days after the infectious blood-meal. twe ...	2000	11388501
immunomodulatory potential of hydrophobic analogs of rigin and their role in providing protection against plasmodium berghei infection in mice.	here, we report the immunomodulating potential of n-palmitoyl-amino-ethyl-rigin amide (pr) and n-cholestanyl-amino-ethyl-rigin amide (cr), the two new structural analogs of rigin (an igg-derived tetrapeptide). their activity profiles are compared with native tuftsin (nt) and/or n-palmitoyl-amino-ethyl-tuftsin amide (pt) taken as positive control. to explore the possibility of their use as targeting molecules, they are incorporated into the liposome bilayer and, subsequently, interacted with macr ...	2001	11379040
antiplasmodial activities of some ghanaian plants traditionally used for fever/malaria treatment and of some alkaloids isolated from pleiocarpa mutica; in vivo antimalarial activity of pleiocarpine.	fourteen ghanaian plants used in folk medicine to treat fever/malaria were screened for activity against plasmodium falciparum (strain k1) and were tested for general toxicity to the brine shrimp. extracts from three of the plants, pleiocarpa mutica, cleistopholis patens and uvaria chamae were found to have significant antiplasmodial activity. the extract of u. chamae was toxic to brine shrimps. these findings lend support to the use of these plants in traditional medicine. possible toxicity due ...	2001	11378289
assay of gamma-glutamylcysteine synthetase activity in plasmodium berghei by liquid chromatography with electrochemical detection.	this work describes a high-performance liquid chromatography (hplc) method to determine gamma-glutamylcysteine (gamma-gc), the intermediate product of glutathione biosynthesis. separation relies on isocratic reversed-phase chromatography using a symmetry c18 hplc column, particle size 5 microm, 4.6 x 250 mm i.d. the mobile phase is methanol-dibasic sodium phosphate (ph 6.6; 2.8 mm) (10:90, v/v) at the flow-rate of 0.5 ml/min and detection is operated electrochemically (+200 and +550 mv) with a p ...	2001	11377058
interspecies conservation of gene order and intron-exon structure in a genomic locus of high gene density and complexity in plasmodium.	a 13.6 kb contig of chromosome 5 of plasmodium berghei, a rodent malaria parasite, has been sequenced and analysed for its coding potential. assembly and comparison of this genomic locus with the orthologous locus on chromosome 10 of the human malaria plasmodium falciparum revealed an unexpectedly high level of conservation of the gene organisation and complexity, only partially predicted by current gene-finder algorithms. adjacent putative genes, transcribed from complementary strands, overlap ...	2001	11353075
knockout of the rodent malaria parasite chitinase pbcht1 reduces infectivity to mosquitoes.	during mosquito transmission, malaria ookinetes must cross a chitin-containing structure known as the peritrophic matrix (pm), which surrounds the infected blood meal in the mosquito midgut. in turn, ookinetes produce multiple chitinase activities presumably aimed at disrupting this physical barrier to allow ookinete invasion of the midgut epithelium. plasmodium chitinase activities are demonstrated targets for human and avian malaria transmission blockade with the chitinase inhibitor allosamidi ...	2001	11349074
human antibodies against plasmodium falciparum liver-stage antigen 3 cross-react with plasmodium yoelii preerythrocytic-stage epitopes and inhibit sporozoite invasion in vitro and in vivo.	the plasmodium falciparum liver-stage antigen 3 (lsa3), a recently identified preerythrocytic antigen, induces protection against malaria in chimpanzees. using antibodies from individuals with hyperimmunity to malaria affinity purified on recombinant or synthetic polypeptides of lsa3, we identified four non-cross-reactive b-cell epitopes in plasmodium yoelii preerythrocytic stages. on sporozoites the p. yoelii protein detected has a molecular mass similar to that of lsa3. t-cell epitopes cross-r ...	2001	11349050
inhibition of the malaria parasite by experimental co-infection of mice by west nile virus and plasmodium berghei.		2000	11344791
malaria sporozoites actively enter and pass through rat kupffer cells prior to hepatocyte invasion.	malaria sporozoites have to cross the layer of sinusoidal liver cells to reach their initial site of multiplication in the mammalian host, the hepatocytes. to determine the sinusoidal cell type sporozoites use for extravasation, endothelia or kupffer cells, we quantified sporozoite adhesion to and invasion of sinusoidal cells isolated from rat liver. in vitro invasion assays reveal that plasmodium berghei and p. yoelii sporozoites attach to and enter kupffer cells, but not sinusoidal endothelia. ...	2001	11343244
a critical role of fc receptor-mediated antibody-dependent phagocytosis in the host resistance to blood-stage plasmodium berghei xat infection.	plasmodium berghei xat is an irradiation-induced attenuated variant derived from the lethal strain p. berghei nk65, and its blood-stage parasites are spontaneously cleared in immune competent mice. in the present study, we studied the mechanism of host resistance to blood-stage malaria infection using p. berghei xat. infection enhanced ab-dependent phagocytosis of prbc by splenic macrophages in wild-type c57bl/6 mice. in contrast, fcr gamma-chain knockout (fcrgamma(-/-)) mice, which lack the abi ...	2001	11342646
effects of dihydroartemisinin on fine structure of erythrocytic stages of plasmodium berghei anka strain.	the fine structural changes of plasmodium berghei anka strain after treatment with the dihydroartemisinin (datm) were observed.	2000	11324422
of mice and malaria mutants: unravelling the genetics of drug resistance using rodent malaria models.	it is well recognized that drug resistance is the most significant obstacle to gaining effective malaria control. despite the enormous advances in the knowledge of the biochemistry and molecular biology of malaria parasites, only a few genes determining resistance to the commonly used drugs have been identified. the idea that rodent malaria parasites should be exploited more widely for such work, in view of the practical problems of studying this subject experimentally in human malaria, is prese ...	2001	11323308
cd1d-restricted nk t cells are dispensable for specific antibody responses and protective immunity against liver stage malaria infection in mice.	immunization with a single dose of irradiated sporozoites is sufficient to induce protection against malaria in wild-type mice. although this protection is classically attributed to conventional cd4+ and cd8+ t cells, several recent reports have suggested an important role for cd1-restricted nk t cells in immunity to malaria. in this study, we directly compared the ability of c57bl/6 wild-type and cd1-deficient mice to mount a protective immune response against plasmodium berghei sporozoites. ou ...	2001	11309137
aldolase genes of plasmodium species.		2001	11295188
gene targeting in the rodent malaria parasite plasmodium yoelii.	it is anticipated that the sequencing of plasmodium falciparum genome will soon be completed. rodent models of malaria infection and stable transformation systems provide powerful means of using this information to study gene function in vivo. to date, gene targeting has only been developed for one rodent malaria species, plasmodium berghei. another rodent species, plasmodium yoelii, however, is favored to study the mechanisms of protective immunity to the pre-erythrocytic stages of infection an ...	2001	11295181
in vitro and in vivo antimalarial activity of ferrochloroquine, a ferrocenyl analogue of chloroquine against chloroquine-resistant malaria parasites.	previous studies have shown that ferrochloroquine (fq) exhibited an antimalarial activity against plasmodium spp. the present work confirmed this activity, described the curative effect on p. vinckei and investigated the fq toxicity in vitro and in vivo. the in vitro and in vivo growth inhibition of p. falciparum and p. berghei n, respectively, showed that fq antimalarial activity was 1.5-10 times more potent than chloroquine. fq completely inhibited the in vivo development of both chloroquine-s ...	2001	11293573
functional equivalence of structurally distinct ribosomes in the malaria parasite, plasmodium berghei.	unlike most eukaryotes, many apicomplexan parasites contain only a few unlinked copies of ribosomal rna (rrna) genes. based on stage-specific expression of these genes and structural differences among the rrna molecules it has been suggested that plasmodium spp. produce functionally different ribosomes in different developmental stages. this hypothesis was investigated through comparison of the structure of the large subunit rrna molecules of the rodent malaria parasite, plasmodium berghei, and ...	2001	11292830
assessing vascular permeability during experimental cerebral malaria by a radiolabeled monoclonal antibody technique.	vascular endothelial integrity, assessed by evans blue dye extrusion and radiolabeled monoclonal antibody leakage, was markedly compromised in the brain, lung, kidney, and heart during plasmodium berghei infection, a well-recognized model for human cerebral malaria. the results for vascular permeability from both methods were significantly (p < 0.001) related.	2001	11292776
assessment of the antimalarial potential of tetraoxane wr 148999.	the antimalarial peroxide, dispiro-1,2,4,5-tetraoxane wr 148999, was synergistic with chloroquine, quinine, mefloquine, and artemisinin against both d6 and w2 clones of plasmodium falciparum. in consideration of the contrasting antagonism between artemisinin and chloroquine, these drug combination data imply that wr 148999 and artemisinin may not share a common mechanism of action. for plasmodium berghei-infected mice given oral, subcutaneous, and intraperitoneal doses of wr 148999 ranging from ...	2000	11289666
protective cd8+ t cell responses against the pre-erythrocytic stages of malaria parasites: an overview.	cd8+ t cells have been implicated as critical effector cells in protection against the pre-erythrocytic stage of malaria in mice and humans following irradiated sporozoite immunization. immunization experiments in animal models by several investigators have suggested different strategies for vaccination against malaria and many of the targets from liver stage malaria antigens have been shown to be immunogenic and to protect mice from the sporozoite challenge. several prime/boost protocols with r ...	2001	11285500
biomagnetic separation of contaminating host leukocytes from plasmodium-infected erythrocytes.	carlton, j. m-r., yowell, c. a., sturrock, k. a., and dame, j. b. 2001. biomagnetic separation of contaminating host leukocytes from plasmodium-infected erythrocytes. experimental parasitology 97, 111-114.	2001	11281708
glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase. a novel bifunctional enzyme in malaria parasites.	plasmodium falciparum glucose 6-phosphate dehydrogenase (pf glc6pd), compared to other glc6pds has an additional 300 amino acids at the n-terminus. they are not related to glc6pd but are similar to a family of proteins (devb) of unknown function, some of which are encoded next to glc6pd in certain bacteria. the human devb homologue has recently been shown to have 6-phosphogluconolactonase (6pgl) activity. this suggests pf glc6pd may be a bifunctional enzyme, the evolution of which has involved t ...	2001	11277923
suppressed expression of hypoxanthine-guanine phosphoribosyltransferase (hgprt) in an irradiation-attenuated plasmodium berghei xat strain.	plasmodium berghei xat (xat) is a non-reversible, non-lethal type malaria parasite strain derived from the highly virulent lethal p. berghei nk65 (nk65) by x-irradiation. the difference in polypeptide expression between nk65 and xat was examined in this study. western blot patterns of the parasite polypeptides showed that a 30-kda polypeptide was not detected in xat. in the present paper, we focused the study on the difference in the expression of the 30-kda polypeptide between xat and nk65. alt ...	1999	11269277
complementation of plasmodium berghei trap knockout parasites using human dihydrofolate reductase gene as a selectable marker.	previously we have used the plasmodium dihydrofolate reductase thymidylate synthase (dhfr-ts) selectable marker to generate plasmodium berghei trap null mutant parasites. these trap null mutants do not glide and they showed a great reduction in their ability to infect mosquito salivary glands and the hepatocytes of the vertebrate host. thus far, complementation of these knockout parasites was not possible due to the lack of additional selectable markers. recently, a new selectable marker, based ...	2001	11254963
bacteria expressing single-chain immunotoxin inhibit malaria parasite development in mosquitoes.	single-chain immunotoxins are ideal tools to selectively kill infectious agents. in applying this technology to block transmission of malaria parasites in the mosquito vector, we have constructed a single-chain immunotoxin composed of a single-chain antibody fragment (scfv) directed to pbs2l on the surface of plasmodium berghei ookinetes linked to a lytic peptide, shiva-1. the single-chain immunotoxin was expressed in escherichia coli, and the protein was purified by a ni-nta column. the single- ...	2001	11254957
antibody recognition of rodent malaria parasite antigens exposed at the infected erythrocyte surface: specificity of immunity generated in hyperimmune mice.	in regions where malaria is endemic, inhabitants remain susceptible to repeated reinfection as they develop and maintain clinical immunity. this immunity includes responses to surface-exposed antigens on plasmodium sp.-infected erythrocytes. some of these parasite-encoded antigens may be diverse and phenotypically variable, and the ability to respond to this diversity and variability is an important component of acquired immunity. characterizing the relative specificities of antibody responses d ...	2001	11254617
removal of the circumsporozoite protein (csp) glycosylphosphatidylinositol signal sequence from a csp dna vaccine enhances induction of csp-specific th2 type immune responses and improvesprotection against malaria infection.	the c terminus of the circumsporozoite protein (csp) is anchored to the parasite cell membrane by a glycosylphosphatidylinositol (gpi) glycolipid. this gpi signal sequence functions poorly in heterologous eukaryotic cells, causing csp retention within internal cell organelles during genetic immunization. cellular location of antigen has quantitative and qualitative effects on immune responses induced by genetic immunization. removal of the gpi signal sequence had a profound effect on induction a ...	2001	11241272
in-vivo antimalarial activity of cassia occidentalis, morinda morindoides and phyllanthus niruri.	the ethanolic, dichloromethane and lyophilized aqueous extracts of cassia occidentalis root bark, morinda morindoides leaves and whole plants of phyllanthus niruri were evaluated for their antimalarial actvity in vivo, in 4-day, suppressive assays against plasmodium berghei anka in mice. no toxic effect or mortality was observed in mice treated, orally, with any of the extracts as a single dose, of 500 mg/kg body weight, or as the same dose given twice weekly for 4 weeks (to give a total dose of ...	2001	11235553
potent in vivo antimalarial activity of 3,15-di-o-acetylbruceolide against plasmodium berghei infection in mice.	the antimalarial activity of the o-acylated bruceolide derivative, 3,15-di-o-acetylbruceolide, was evaluated against plasmodium berghei in vivo. the concentration of 3,15-di-o-acetylbruceolide required for 50% suppression (ed50) of p. berghei in mice was 0.46 +/- 0.06 mg/kg/day, whereas bruceolide was only half as effective as 3,15-di-o-acetylbruceolide. two antimalarial drugs used clinically, chloroquine and artemisinin, demonstrated only low activity corresponding to 1/4 and 1/12 of the ed50 v ...	2000	11227768
the plasmodium falciparum knob-associated pfemp3 antigen is also expressed at pre-erythrocytic stages and induces antibodies which inhibit sporozoite invasion.	the expression of the pfemp3 gene and the corresponding pfemp3 knob-associated protein in the pre-erythrocytic stages of plasmodium falciparum was demonstrated by rt-pcr, western blots, ifat and iem. the antigen was found on the surface of the sporozoite and in the cytoplasm of mature hepatic stage parasites. immunological cross-reactivity was observed with sporozoites from the rodent malaria parasites plasmodium yoelii yoelii and plasmodium berghei and was exploited to assess a potential role o ...	2001	11223132
anopheles gambiae laminin interacts with the p25 surface protein of plasmodium berghei ookinetes.	laminin is a major constituent of the basal lamina surrounding the midgut of the malaria vectors that has been implicated in the development of the plasmodium oocyst. in this report we describe the cloning of the anopheles gambiae gene encoding the laminin gamma 1 polypeptide and follow its expression during mosquito development. to further investigate the putative role of laminin in the transmission of the malaria parasite we studied the potential binding of the p25 surface protein of plasmodiu ...	2001	11223130
[culture of plasmodium berghei with the short life span in mouse erythrocytes: evaluation of chloroquine resistance in three strains of the malaria parasite].	this comparative study was made to examine chroloquine inhibition of c14-hypoxanthine incorporation (preferably nucleic acid precursor for plasmodium) in the short-living red blood cell cultures in mice infected with p. berghei strains differently sensitive to the agent 24 hours after incubation. these included 1) chloroquine-sensitive h strain; 2) lnk-65 strain having a spontaneously 2-3-fold decreased sensitivity to the agent; 3) strain lnk-65 chr selected for high resistance to chloroquine. i ...	1999	11221002
role of macrophages in experimental malaria: vii--studies on adoptive transfer of macrophages.	adoptive transfer of purified macrophages harvested from normal, plasmodium berghei infected and latent/cured mice and also macrophages exposed to parasites in vitro were carried out to see the role of macrophages in transferring immunity against p. berghei infection. macrophages obtained from mice having high parasitaemia at a dose of one million cells/animal showed significant increase in survival period (sp) and k values, compared to controls. macrophages exposed to low parasite density confe ...	2000	11198398
triclosan offers protection against blood stages of malaria by inhibiting enoyl-acp reductase of plasmodium falciparum.	the antimicrobial biocide triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol] potently inhibits the growth of plasmodium falciparum in vitro and, in a mouse model, plasmodium berghei in vivo. inhibition of [14c]acetate and [14c]malonyl-coa incorporation into fatty acids in vivo and in vitro, respectively, by triclosan implicate fabi as its target. here we demonstrate that the enoyl-acp reductase purified from p. falciparum is triclosan sensitive. also, we present the evidence for the existence of ...	2001	11175846
identification of the class xiv myosins pb-myoa and py-myoa and expression in plasmodium sporozoites.		2001	11166399
myosin a expressions in sporogonic stages of plasmodium.		2000	11163454
a central role for p48/45 in malaria parasite male gamete fertility.	fertilization and zygote development are obligate features of the malaria parasite life cycle and occur during parasite transmission to mosquitoes. the surface protein pfs48/45 is expressed by male and female gametes of plasmodium falciparum and pfs48/45 antibodies prevent zygote development and transmission. here, gene disruption was used to show that pfs48/45 and the ortholog pbs48/45 from a rodent malaria parasite p. berghei play a conserved and important role in fertilization. p48/45- parasi ...	2001	11163248
plasmodium yoelii: efficient in vitro invasion and complete development of sporozoites in mouse hepatic cell lines.		2000	11162379
low-complexity regions in plasmodium falciparum proteins.	full-sequence data available for plasmodium falciparum chromosomes 2 and 3 are exploited to perform a statistical analysis of the long tracts of biased amino acid composition that characterize the vast majority of p. falciparum proteins and to make a comparison with similarly defined tracts from other simple eukaryotes. when the relatively minor subset of prevalently hydrophobic segments is discarded from the set of low-complexity segments identified by current segmentation methods in p. falcipa ...	2001	11157785
synthesis, antimalarial activity, biomimetic iron(ii) chemistry, and in vivo metabolism of novel, potent c-10-phenoxy derivatives of dihydroartemisinin.	the combination of tmsotf and agclo(4) promotes the efficient c-10-phenoxylation of dihydroartemisinin (3) in good chemical yield and excellent stereoselectivity. all of the new phenoxy derivatives have potent in vitro antimalarial activity. on the basis of the excellent yield and stereoselectivity obtained for the p-trifluoromethyl derivative 7b, this compound and the parent phenyl-substituted derivative 5b were selected for in vivo biological evaluation against plasmodium berghei in the mouse ...	2001	11141088
scant parasitemia in balb/c mice with congenital malaria infection.	balb/c mice were examined to determine whether or not they transmitted rodent malaria, plasmodium berghei, to their fetuses. on the 15th day of pregnancy, mice were inoculated with approximately 3 x 10(6) p. berghei-infected erythrocytes by peritoneal injection. the blood from 27 adult females and 196 neonates was examined using a sensitive polymerase chain reaction (pcr) method with a detection level of approximately 1 parasite/microl blood. the average parasitemia of females at delivery was 8. ...	2000	11128475
multiple display of peptides and proteins on a macromolecular scaffold derived from a multienzyme complex.	the acyltransferase components (e2) from the family of 2-oxo acid dehydrogenase multienzyme complexes form large protein scaffolds, to which multiple copies of peripheral enzymes bind tightly but non-covalently. sixty copies of the e2 polypeptide from the pyruvate dehydrogenase multienzyme complex of bacillus stearothermophilus assemble to form a pentagonal dodecahedral scaffold with icosahedral symmetry. this protein scaffold can be modified to present foreign peptides and proteins on its surfa ...	2001	11124904
a role for linoleic acid in erythrocytes infected with plasmodium berghei.	unesterified fatty acids were measured in mouse erythrocytes infected either with chloroquine-susceptible (cs) or with chloroquine-resistant (cr) lines of plasmodium berghei. this work was undertaken to identify candidates for the lipid involved in ferriprotoporphyrin ix (fp) polymerization. linoleic, oleic, palmitic, and stearic acids were quantified by gas chromatography/mass spectrometry. in total, they increased 4-fold with cs infections and 6-fold with cr infections. treating infected mice ...	2000	11113630
pfsbp1, a maurer's cleft plasmodium falciparum protein, is associated with the erythrocyte skeleton.	antibodies from hyperimmune monkey sera, selected by absorption to plasmodium falciparum-infected erythrocytes, and elution at acidic ph, allowed us to characterize a novel parasite protein, pfsbp1 (p. falciparum skeleton binding protein 1). pfsbp1 is an integral membrane protein of parasite-induced membranous structures associated with the erythrocyte plasma membrane and referred to as maurer's clefts. the carboxy-terminal domain of pfsbp1, exposed within the cytoplasm of the host cell, interac ...	2000	11087921
toxoplasma gondii homologue of plasmodium apical membrane antigen 1 is involved in invasion of host cells.	proteins with constitutive or transient localization on the surface of apicomplexa parasites are of particular interest for their potential role in the invasion of host cells. we describe the identification and characterization of tgama1, the toxoplasma gondii homolog of the plasmodium apical membrane antigen 1 (ama1), which has been shown to elicit a protective immune response against merozoites dependent on the correct pairing of its numerous disulfide bonds. tgama1 shows between 19% (plasmodi ...	2000	11083833
molecular interactions between anopheles stephensi midgut cells and plasmodium berghei: the time bomb theory of ookinete invasion of mosquitoes.	we present a detailed analysis of the interactions between anopheles stephensi midgut epithelial cells and plasmodium berghei ookinetes during invasion of the mosquito by the parasite. in this mosquito, p. berghei ookinetes invade polarized columnar epithelial cells with microvilli, which do not express high levels of vesicular atpase. the invaded cells are damaged, protrude towards the midgut lumen and suffer other characteristic changes, including induction of nitric oxide synthase (nos) expre ...	2000	11080150
protective immunity against plasmodium berghei malaria after administration of interleukin-12.	interleukin-12 (il-12) has been shown to induce protection in mice against plasmodium cyanomolgi and in rhesus monkey against plasmodium yeolii. this study is to investigate whether recombinant il-12 can induce protection in balb/c mice against plasmodium berghei. five mice were given intraperitoneal injection of 7.5 micrograms/kg body weight recombinant mouse il-12 two days prior to challenge with 5 x 10(4) of p. berghei, while mice in the control group were injected with 0.5 ml of normal salin ...	1999	11068418
anti-malarial activity of leaf-extract of hydrangea macrophylla, a common japanese plant.	to find a new anti-malarial medicine derived from natural resources, we examined the leaves of 13 common japanese plants in vitro. among them, a leaf-extract of hydrangea macrophylla, a common japanese flower, inhibited the parasitic growth of plasmodium falciparum. the ic50 of hydrangea macrophylla leaf extract to plasmodium falciparum was 0.18 microg/ml. the ic50 to nih 3t3-3 cells, from a normal mouse cell line, was 7.2 microg/ml. thus, selective toxicity was 40. for the in vivo test, we inoc ...	2000	11061572
some in vitro invasion inhibition of red cells by in vivo nonprotective anti-ldh antibodies of plasmodium berghei.	in plasmodium berghei, sephadex g-200 purified lactate dehydrogenase (ldh) fraction immunized mice did not exhibit protection when challenged with 1 x 10(6) p. berghei-parasitized erythrocytes. however, ldh immunized mice seroconverted and showed an antibody titre of 1:2048 by indirect haemagglutination (iha) and 1:160 by indirect fluorescent antibody (ifa) assays. fluorescence was distributed evenly on p. berghei-parasitized red cells showing no specific location of parasite ldh. anti-ldh antib ...	2000	11048428
a search for natural bioactive compounds in bolivia through a multidisciplinary approach. part iv. is a new haem polymerisation inhibition test pertinent for the detection of antimalarial natural products?	the search for new antimalarial agents in plant crude extracts using traditional screening tests is time-consuming and expensive. new in vitro alternative techniques, based on specific metabolic or enzymatic process, have recently been developed to circumvent testing of antimalarial activity in parasite culture. the haem polymerisation inhibition test (hpia) was proposed as a possible routine in vitro assay for the detection of antimalarial activity in natural products. a total of 178 plant extr ...	2000	11025165
effects of endotoxin and dexamethasone on cerebral malaria in mice.	cba/t6 and dba/2j mice inoculated with plasmodium berghei anka (pba) develop cerebral involvement 6-8 days post-inoculation, from which the cba mice almost invariably die and the dba mice recover. dexamethasone (dxm; 80 mg/kg) given to inoculated cba mice twice, on day 3 and again within 48 h, reduced the cerebral symptoms and prevented death from cerebral malaria. plasma tumour necrosis factor (tnf) levels, which increased at the time of the cerebral symptoms, were also reduced in these dxm-tre ...	1995	11023408
the roles of the glycosylphosphatidylinositol anchor on the production and immunogenicity of recombinant ookinete surface antigen pbs21 of plasmodium berghei when prepared in a baculovirus expression system.	malarial ookinetes express an immunodominant surface protein (p28) that is a priority candidate for the development of transmission-blocking vaccines. the full length p28 gene from plasmodium berghei [pbs21(1-213)] and a deletion construct [pbs21(1-188)] encoding a protein that lacks the 25 c-terminal amino acids, including the glycosylphosphatidylinositol (gpi) anchor signal, were expressed in insect cells using baculovirus vectors. pbs21(1-213) protein is strongly hydrophobic, found in the cyt ...	2000	11012975
oxygenated chalcones and bischalcones as potential antimalarial agents.	oxygenated chalcones (3a,b) and bischalcones (4a-j) have been synthesized and evaluated for antimalarial activity against chloroquine sensitive and resistant strains of plasmodium berghei in mice. some of the screened compounds, 3a, 4c, 4e, 4f and 4i, have shown significant activity at 100 mg/kg dose against sensitive strain.	2000	11012019
the synthetic, oxidized c-terminal fragment of the plasmodium berghei circumsporozoite protein elicits a high protective response.	a polypeptide of 69 amino acids (pbcs 242-310) encompassing the c-terminal region of the circumsporozoite protein of plasmodium berghei (pbcs) was generated using solid-phase peptide synthesis. the immunological and protective properties of peptide pbcs 242-310 were studied in balb/c mice (h-2d). two subcutaneous injections, in the presence of ifa at the base of the tail, generated (i) high titers of anti-peptide antibodies which also recognized the native p. berghei cs protein, (ii) cytolytic t ...	2000	11009102
[genetic approach to the study of the sporogonic cycle in plasmodium].	the development of transformation and mutagenesis techniques of the two species of plasmodium most studied--plasmodium falciparum (human parasite) and plasmodium berghei (rodent parasite)--opens new perspectives for the molecular study on the parasite sporogonic cycle in the insect vector. the parasite's stages that can be genetically transformed (the asexual erythrocytic stages) and gametocytes. the function of proteins coded by genes present in single copy in the genome can thus be studied aft ...	1999	11000961
genetic vaccination against malaria infection by intradermal and epidermal injections of a plasmid containing the gene encoding the plasmodium berghei circumsporozoite protein.	the circumsporozoite protein (csp) from the surface of sporozoite stage plasmodium sp. malaria parasites is among the most important of the malaria vaccine candidates. gene gun injection of genetic vaccines encoding plasmodium berghei csp induces a significant protective effect against sporozoite challenge; however, intramuscular injection does not. in the present study we compared the immune responses and protective effects induced by p. berghei csp genetic vaccines delivered intradermally with ...	2000	10992502
hematin polymerization assay as a high-throughput screen for identification of new antimalarial pharmacophores.	hematin polymerization is a parasite-specific process that enables the detoxification of heme following its release in the lysosomal digestive vacuole during hemoglobin degradation, and represents both an essential and a unique pharmacological drug target. we have developed a high-throughput in vitro microassay of hematin polymerization based on the detection of (14)c-labeled hematin incorporated into polymeric hemozoin (malaria pigment). the assay uses 96-well filtration microplates and require ...	2000	10991837
characterisation and expression of pbs25, a sexual and sporogonic stage specific protein of plasmodium berghei.	following gametogenesis and fertilisation in the bloodmeal within the mosquito midgut, the newly formed zygotes of the malaria parasite develop into motile invasive ookinetes. during this development, surface molecules are synthesised de novo including molecules of 21-28 kda from the zygote-ookinete stages. an antiserum recognising a 26 kda protein of plasmodium berghei was used to clone the corresponding gene from a cdna library, which was shown to be identical to the reported pbs25 gene sequen ...	2000	10989152
targeted terminal deletions as a tool for functional genomics studies in plasmodium.	we describe a transfection system that induces terminal deletions at specific chromosome ends in malaria parasites using a linear construct containing telomeric repeats at one end and plasmodial sequences able to drive homologous recombination at the other. a site-specific deletion was generated at one extremity of chromosome 5 of plasmodium berghei, which was stably maintained in the parasite population selected after transfection. the telomeric repeat array introduced with the construct reache ...	2000	10984459
distinct roles for pbs21 and pbs25 in the in vitro ookinete to oocyst transformation of plasmodium berghei.	we have developed an in vitro culture system for early sporogonic stages of plasmodium berghei, which can be used to study developmental events normally taking place in the midgut of an infected mosquito. these include penetration of insect cells by the mature ookinete, transformation into oocysts and the early development of the latter, sustained through several rounds of nuclear division. the system, based upon co-culture of enriched ookinetes with several established insect cell lines, was us ...	2000	10984433
inhibition of the mosquito transmission of plasmodium berghei by malarone (atovaquone-proguanil).	sera from patients treated with atovaquone-proguanil (malarone) have previously been shown to inhibit the mosquito transmission of plasmodium falciparum, though the inhibition was not complete and the effect declined 2 weeks after treatment. in marked contrast, the inhibition of transmission of p. berghei by human sera (fed to mosquitoes, with p. berghei gametocytes, via membrane feeders) from volunteers treated with atovaquone-proguanil was total up to day 28 post-treatment and still very signi ...	2000	10983555
differential interleukin-10 expression in interferon regulatory factor-1 deficient mice during plasmodium berghei blood-stage infection.	mice deficient of functional interferon regulatory factor-1 (irf-1-/-) by targeted gene disruption infected with a lethal murine malaria strain, plasmodium berghei anka survived longer than its wild-type littermates despite the inability to induce appreciable amounts of interferon-gamma (ifn-gamma) and nitric oxide. in addition, infected irf-1-/- mice displayed less organ injury with reduced necrosis and inflammation. both wild-type and irf-1-/- mice treated with exogenous interleukin-12 (il-12) ...	2000	10972849
morphine modulation of plasmodial-antigens-induced colony-stimulating factors production by macrophages.	morphine abuse is known to cause immunosuppression and enhanced host susceptibility to malaria. we studied the effect of morphine on the plasmodium berghei total-parasite-antigens soluble in culture medium (p.b.sa)-induced production of colony-stimulating factors (csfs) by mouse peritoneal macrophages, in vitro. morphine exerted a concentration-dependent biphasic modulatory effect; at 1 x 10(-4)-1 x 10 x 10(-6) m it slightly inhibited, whereas at 1 x 10(-8)-1 x 10(-10) m it augmented the product ...	2000	10954037
immunopathology of cerebral malaria: morphological evidence of parasite sequestration in murine brain microvasculature.	a murine model that closely resembles human cerebral malaria is presented, in which characteristic features of parasite sequestration and inflammation in the brain are clearly demonstrable. "young" (balb/c x c57bl/6)f(1) mice infected with plasmodium berghei (anka) developed typical neurological symptoms 7 to 8 days later and then died, although their parasitemias were below 20%. older animals were less susceptible. immunohistopathology and ultrastructure demonstrated that neurological symptoms ...	2000	10948166
dichloroacetate (dca) reduces brain lactate but increases brain glutamine in experimental cerebral malaria: a 1h-nmr study.	recent findings that levels of brain lactate and alanine were elevated in murine cerebral malaria led us to investigate the effect of dichloroacetate (dca; 60 mg/kg), an activator of pyruvate dehydrogenase, on the levels of brain metabolites, and on the survival of mice infected with plasmodium berghei anka which normally causes lethal cerebral malaria. dca significantly reduced brain lactate and alanine levels when administered to infected mice, had no effect on the tca cycle-related metabolite ...	2000	10939296
tissue distribution of indoleamine 2,3-dioxygenase in normal and malaria-infected tissue.	an immunohistochemical method was developed, using a polyclonal antibody, to detect the enzyme indoleamine 2,3-dioxygenase (ido) in normal and malaria-infected tissue. plasmodium berghei anka, a cerebral malaria (cm) model, and p. berghei k173, a non-cerebral malaria (ncm) model, were used. it was found that vascular endothelial cells were the primary site of ido expression in both models of malaria infection and that this response was systemic, with the vascular endothelium of brain, heart, lun ...	2000	10939286
import of host delta-aminolevulinate dehydratase into the malarial parasite: identification of a new drug target.	the parasite plasmodium berghei imports the enzyme delta-aminolevulinate dehydratase (alad), and perhaps the subsequent enzymes of the pathway from the host red blood cell to sustain heme synthesis. here we have studied the mechanism of this import. a 65-kda protein on the p. berghei membrane specifically bound to mouse red blood cell alad, and a 93-amino-acid fragment (alad-deltanc) of the host erythrocyte alad was able to compete with the full-length enzyme for binding to the p. berghei membra ...	2000	10932227
essential role of cd8 palmitoylation in cd8 coreceptor function.	to investigate the molecular basis that makes heterodimeric cd8alphabeta a more efficient coreceptor than homodimeric cd8alphaalpha, we used various cd8 transfectants of t1.4 t cell hybridomas, which are specific for h-2kd, and a photoreactive derivative of the plasmodium berghei circumsporozoite peptide pbcs 252-260 (syipsaeki). we demonstrate that cd8 is palmitoylated at the cytoplasmic tail of cd8beta and that this allows partitioning of cd8alphabeta, but not of cd8alphaalpha, in lipid rafts. ...	2000	10925291
effects of interruption of apicoplast function on malaria infection, development, and transmission.	a chloroplast-like organelle is present in many species of the apicomplexa phylum. we have previously demonstrated that the plastid organelle of plasmodium faciparum is essential to the survival of the blood-stage malaria parasite in culture. one known function of the plastid organelle in another apicomplexan, toxoplasma gondii, involves the formation of the parasitophorous vacuole. the effects of interruption of plastid function on sporozoites and sexual-stage parasites have not been investigat ...	2000	10924753
antiplasmodial, analgesic, and anti-inflammatory activities of the aqueous extract of the stem bark of erythrina senegalensis.	the in vivo antiplasmodial, analgesic and anti-inflammatory properties of erythrina senegalensis, an ornamental plant commonly used in northern nigeria for the treatment of fevers, was evaluated. aqueous extracts of the stem bark of the plant was used for the study. the in vivo antiplasmodial activity of the aqueous extract against plasmodium berghei was assessed using the suppressive and curative test procedures. analgesic activity was assessed using the acetic acid (0.75%v/v) induced abdominal ...	2000	10904174
alpha -galactosylceramide-activated valpha 14 natural killer t cells mediate protection against murine malaria.	natural killer t (nkt) cells are a unique population of lymphocytes that coexpress a semiinvariant t cell and natural killer cell receptors, which are particularly abundant in the liver. to investigate the possible effect of these cells on the development of the liver stages of malaria parasites, a glycolipid, alpha-galactosylceramide (alpha-galcer), known to selectively activate valpha14 nkt cells in the context of cd1d molecules, was administered to sporozoite-inoculated mice. the administrati ...	2000	10900007
involvement of ifn-gamma receptor-medicated signaling in pathology and anti-malarial immunity induced by plasmodium berghei infection.	ifn-gamma has been implicated in the pathogenesis of experimental cerebral malaria (ecm). we have used mice lacking the alpha chain of the ifn-gamma receptor (ko mice) to define its role in the pathogenesis of ecm. infected ko mice did not develop ecm and showed no leukocyte or parasite sequestration in the brain, and no hemorrhages. the resistance of ko mice to ecm was associated with the absence of any increases of tnf-alpha and icam-1 proteins in the brain, which are both essential for ecm. w ...	2000	10898501
synthesis and antimalarial activity of sixteen dispiro-1,2,4, 5-tetraoxanes: alkyl-substituted 7,8,15,16-tetraoxadispiro[5.2.5. 2]hexadecanes.	sixteen alkyl-substituted dispiro-1,2,4,5-tetraoxanes (7,8,15, 16-tetraoxadispiro[5.2.5.2]hexadecanes) were synthesized to explore dispiro-1,2,4,5-tetraoxane sar and to identify tetraoxanes with better oral antimalarial activity than prototype tetraoxane 1 (wr 148999). the tetraoxanes were prepared either by peroxidation of the corresponding cyclohexanone derivatives in h(2)so(4)/ch(3)cn or by ozonolysis of the corresponding cyclohexanone methyl oximes. those tetraoxanes with alkyl substituents ...	2000	10893313
characterization of a differential immunoscreen epitope of plasmodium falciparum using combinatorial agents.	a differential serological screening of a lambdagt11 cdna expression library has identified several clones, which react exclusively to sera samples from persons clinically immune to malaria but not to acute malaria patient sera. one such clone, ipf9, has a 315-bp cdna insert, which was found to be conserved in different strains of the human and rodent malarial parasite plasmodium falciparum and plasmodium berghei, respectively. the induced expression product of ipf9 was used to generate polyclon ...	2000	10886717
experimental erythrocytic malaria infection induces elevated serum amyloid p production in mice.	experimental blood-stage malaria infection of nih mice was observed to induce an acute phase response (apr). infection of mice with either p. chabaudi, p. vinckei (both non-lethal) or p. berghei (lethal infection) resulted in elevated serum amyloid p (sap) production, the major acute phase protein in mice. peak production occurred at the peak of the parasitaemia (approximately day 10 post infection). sap isolated from the serum of p. chabaudi infected mice was shown to inhibit the growth of intr ...	2000	10880833
determination of mosquito bloodmeal ph in situ by ion-selective microelectrode measurement: implications for the regulation of malarial gametogenesis.	malarial gametocytes circulate in the peripheral blood of the vertebrate host as developmentally arrested intra-erythrocytic cells, which only resume development into gametes when ingested into the bloodmeal of the female mosquito vector. the ensuing development encompasses sexual reproduction and mediates parasite transmission to the insect. in vitro the induction of gametogenesis requires a drop in temperature and either a ph increase from physiological blood ph (ca ph 7.4) to about ph 8.0, or ...	2000	10874717
flow cytometry assay for counting micronucleated erythrocytes: development process.	development of any new assay proceeds in several phases. when an assay is intended for regular use to support regulatory decision-making, there are significant additional stages in the development process beyond the initial description of the method. in this paper we discuss some of the studies related to the development of a flow cytometric method for counting micronuclei in rodent erythrocytes. studies related to fixation methods and conditions, standardization of dna staining, and antibody st ...	2000	10873482
plasmodium berghei: cerebral malaria in cba mice is not clearly related to plasma tnf levels or intensity of histopathological changes.	plasmodium berghei anka infection in cba/j mice leads to the development of cerebral malaria (cm) that kills 80-90% of the animals in 6-9 days. this model has been used to study the pathogenesis of cm, which is a major cause of morbidity and mortality in plasmodium falciparum-infected individuals. the role of cytokines in the induction of cm in the murine model has been well documented, but most studies have been restricted to the peak of neurological manifestations. here we used a sequential ap ...	2000	10864512
delayed mortality and attenuated thrombocytopenia associated with severe malaria in urokinase- and urokinase receptor-deficient mice.	we explored the role of urokinase and tissue-type plasminogen activators (upa and tpa), as well as the upa receptor (upar; cd87) in mouse severe malaria (sm), using genetically deficient (-/-) mice. the mortality resulting from plasmodium berghei anka infection was delayed in upa(-/-) and upar(-/-) mice but was similar to that of the wild type (+/+) in tpa(-/-) mice. parasitemia levels were similar in upa(-/-), upar(-/-), and +/+ mice. production of tumor necrosis factor, as judged from the plas ...	2000	10858190