Publications

TitleAbstractYear
Filter
PMID
Filter
plasmodium berghei - infected red cells sorted according to dna content.a cell-sorting method is described for the analysis and separation of red blood cells in plasmodium berghei-infected mouse blood based on their dna content. this method involves a selective uptake of the bis-benzimidazole dye 33258 hoechst, a dna-binding dye, by red blood cells containing parasites. infected blood is incubated at 37 degrees c with the dye then washed at 4 degrees c to remove unbound dye. uninfected cells are then non-fluorescent at the characteristic wavelengths for 33258 hoechs ...197990356
particulate beta 1-3 glucan and casual prophylaxis of mouse malaria (plasmodium berghei). 1979121199
splenic mediated erythrocyte cytotoxicity in malaria.cell-mediated cytotoxicity in virulent rodent malaria has been demonstrated in vitro, whereby splenic cells effected specific lysis of 51cr-labelled erythrocytes from parasitized animals. more than one cellular cytolytic effector system appeared to be operative in the mouse. one effector system involved splenic macrophages, from normal or immune animals, which were increasingly cytotoxic to target cells in the presence of antibody. a second effector system involved nylonpurified immune spleen ce ...19751095474
thiosemicarbazones and hydrazones of alpha-methylchalkone as potential chemotherapeutic agents.the effectiveness of chalkones and derivatives as antibacterial and antifungal agents stimulated our interest in the possibility of coupling this type of compound with certain hydrazines and thiosemicarbazides to determine the potential chemotherapeutic activity of these combinations as anticancer and antimalarial agents. accordingly, 18 hydrazine and thiosemicarbazide derivatives of alpha-methylchalkone (dypnone) have been synthesized for study as potential antitumor agents in animal tumor syst ...19751099024
alterations in the permeability of mouse erythrocytes infected with the malaria parasite, plasmodium berghei. 19751099038
development of a model ribosomal rna hybridization assay for the detection of sarcocystis and other coccidia.two regions of the primary structure of the small subunit rrna of sarcocystis muris bradyzoites were compared with nucleotide sequences of s. gigantea, toxoplasma gondii, plasmodium berghei and mus musculus and used to design genus- and species-specific probes for the detection and identification of coccidia. total cellular rna of purified s. muris, s. cruzi, t. gondii and eimeria nieschulzi and coccidia-infected tissues of mouse, ox, sheep and pig, were assayed using twenty-base oligomers label ...19921423056
the chemotherapy of rodent malaria.xliii. indolo (3,2-c) quinoline-n-oxides.a number of novel indolo (3,2-c) quinoline-n-oxides possess antimalarial activity. one of the series, compound cm 6606, has a superior blood schizontocidal action against drug-sensitive plasmodium berghei in the mouse to that of chloroquine, although it is not fully active against strains highly resistant to chloroquine or mefloquine. it also shows some tissue schizontocidal (causal prophylactic) and gametocytocidal action in mice infected with p. yoelii nigeriensis. the structure activity of th ...19883077021
biochemical studies on mouse liver following plasmodium berghei infection.the lipid composition of mouse liver following infection with p. berghei was investigated. the liver lipid contents of infected animals were greatly increased mainly due to the accumulation of triacylglycerides. there was enhanced lipid concentration (85.29%). significantly (23.7%) depleted liver cholesterol was also found in the mice. similarly, phospholipid contents of liver were also decreased by 19.90 per cent. the liver from p. berghei infected mouse produced more lipid peroxide, as compare ...19921601476
failure to protect mus musculus against plasmodium berghei with footpad injections of killed parasites incorporated in complete freund's adjuvant.the stimulation of cell-mediated immunity by the injection of antigen from killed parasites incorporated in complete freund's adjuvant did not protect mus musculus from the erythrocytic stages of plasmodium berghei. agglutinating antibodies could not be detected, but delayed hypersensitivity was demonstrable. apparently thymocyte sensitization alone was not sufficient to afford protection.19751102649
[chemotherapeutically active nitro compounds. 2nd communication: nitrodiphenyl sulfones (author's transl)].a number of new 4-nitro-4'-amino-diphenyl sulfones and related compounds were prepared and investigated as to their therapeutic activity. they showed a good systemic activity against tubercle bacilli (m. bovis, nmri mouse) and plasmodia (p. berghei, nmri mouse). the test results reveal that the 4-nitro-4'-amino-diphenyl sulfones possess a spectrum of activity similar to that of diamino-diphenyl sulfone (dds). it is assumed that 4-nitro-4'-amino-diphenyl sulfones in vivo are converted into dds de ...1976795435
[determination of the activity of globinase from plasmodium berghei by radiometry with mouse [3h]globin as a substrate]. 19873328465
[antimalarial activity of various isoquinoline alkaloids in the mouse]. 19873331070
the plasmodium berghei-infection in isogenic f1 (c57bl x dba)-mice. i. the course of the infection and immunization experiments.the malarial infection caused by plasmodium berghei (strain k 173) was observed in the isogenic mouse strains c3h, c57bl, dba, and the f1 (c57bl x dba)-hybrids. in addition immunization experiments were carried out by intermittent suppression of the parasite multiplication through maintaining the infected animals on a milk diet for various length of time. the f1-hybrids were the most resistant mice and immunization was most effective in these animals, too. but if the course of the infection was ...1975766337
synthesis of 2-benzyloxy and 2-benzylthio analogues of primaquine as potential antimalarials.a series of 2-benzyloxy and 2-benzylthio analogues of primaquine has been synthesized and evaluated against plasmodium berghei in the mouse and plasmodium cynomolgi in the rhesus monkey. 8-aminoquinoline toxicity, as measured in the rane mouse screen, was reduced, and these compounds showed significant blood schizonticidal antimalarial activity in mice. in monkeys, significant tissue-schizonticidal activity was observed.1977409843
pathology of anopheles stephensi after infection with plasmodium berghei berghei. ii. changes in amino acid contents.infection with plasmodium berghei results in the disease of a relatively high percentage of mosquitoes depending on the experimental conditions. the damage caused by the parasites may be so severe that the host dies. it can also become manifest for instance in a change in the amino acid content of the mosquito homogenate. the amino acid content of mosquitoes fed on a glucose solution, normal mouse blood, or the blood of infected mice was analysed qualitatively and quantitatively over a period of ...1979396730
isolation of plasmodium berghei by hemolysin lysis of infected erythrocytes and evidence for a parasite hexokinase.a rapid and simple procedure has been developed for the isolation of plasmodium berghei parasites from infected-mouse erythrocytes employing the heat stable hemolysin produced by pseudomonas aeruginosa. using parasites isolated by this method, the presence of a parasite specific hexokinase has been demonstrated, providing an explanation for the increased glucose consumption observed with infected cells. enzyme assays and serology were employed in determining the purity and yield of purified para ...1979376819
resolution of antimalarial agents via complex formation with alpha-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy) propionic acid.the resolution of several antimalarial agents via pi-complex formation with alpha-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy) propionic acid (tapa) is reported. since this represents the first use of this agent for the resolution of amines, some details of the separations are presented. the method proved successful for resolving weakly alkaline amines that did not form stable salts with common resolving acids, highly insoluble amines that did not form soluble salts with usual resolving acids, ...1978349156
in vitro infectivity of cryopreserved plasmodium berghei sporozoites to cultured cells.plasmodium berghei sporozoites frozen in mem (eagle) medium supplemented with 10% hydroxyethyl starch and 50% normal mouse serum retained 0.5% infectivity to cultured hepatoma cells, compared to 6.8% before freezing. this demonstrates that frozen-thawed sporozoites can be used in in vitro investigations of the exoerythrocytic malarial parasite and means that when large numbers of sporozoites are available, they may be frozen and preserved for later use.19853890283
fading of malaria immunity in mice.fading of immunity in swiss and c3h/stz mice was progressive, and related to both, the interval elapsed since the last challenge infection and survival of parasites. in both mouse strains the proportion of mice that remained immune to challenge decreased with increasing fading periods. moreover, a shift from delayed mortality to a normal course of infection as seen in non-immune controls was observed in c3h/stz mice. early parameters of fading were increasing peak parasitaemias after challenge i ...1978347653
plasmodium berghei: folic acid levels in mouse erythrocytes. 19734197972
separation of parasitized erythrocytes from plasmodium berghei infected mouse blood. 1977329491
[preparation of an anti-plasmodium berghei serum using the mouse and the rabbit]. 19734594318
time-dependent loss of invasive ability of plasmodium berghei merozoites in vitro.the invasive ability of plasmodium berghei merozoites in vivo was studied following their artificial removal from parasitized mouse red cells using complement-mediated immune lysis in vitro and in vivo. time-course experiments revealed that lysed preparations contained two components contributing to the parasites' infectivity in mice. one component, presumed to be free merozoites released from mature schizont-infected cells, rapidly lost infectivity with time at 1 to 2 c. a second minor componen ...1977325188
propagation of plasmodium berghei and p. vinckei in mouse erythrocytes injected into chick embryos. 19704919090
low-temperature preservation of sporozoites of plasmodium berghei.large numbers of biologically active sporozoites are needed as a source of potential antigen in the development of a malaria vaccine and the most practical method of accumulating sufficient numbers of these forms would be to freeze and store them at low temperature. the purpose of this work was to determine the feasibility of preserving the infectivity of frozen and thawed sporozoites. the results indicate that sporozoites of plasmodium berghei exhibit a typical response to freezing over a wide ...1979120776
the development of a "high volume tissue schizonticidal drug screen" based upon mortality of mice inoculated with sporozoites of plasmodium berghei.a biological test system has been developed to assess the prophylactic activity of compounds against sporozoite-induced plasmodium berghei malaria in mice. the procedure was designed to serve as the foundation of an effort to develop tissue schizonticidal drugs in a manner parallel to that of a previous system employed in the u.s. arym antimalarial drug development program to screen compounds for blood schizonticidal activity. in tests with 35 known antimalarial compounds, the new screen was fou ...1979116556
[changes in plasmodium berghei berghei in mice maintained at high temperatures].the study of the evolution of plasmodium berghei berghei is made in mice kept in a high temperature (35 degrees c) throughout the experiment. some of these mouse parasites (less than 30%) show a gigantic atypical morphology. in the parasite growing in animals kept at 35 degrees c, the amount of dna is higher than dna rate of the parasites growing in control mice (20-22 degrees c). there is no evidence of any relation between the increase of dna amount and the morphological modification of these ...197896992
[influence of a hot environmental temperature on the evolution of experimental paludism of the mouse with plasmodium berghei berghei].swiss mice infected with plasmodium berghei berghei and maintained in permanence in a hot environmental temperature undergo a chronic infection whereas controls maintained at the laboratory temperature develop always an acute and lethal infection. the hot environmental temperature does not seem to have any action on the pathogenicity of the parasites. host defences are stimulated.197896968
rapid, large-scale isolation of plasmodium berghei sporozoites from infected mosquitoes.the discontinuous gradient technique for recovery of malarial sporozoites from mosquitoes (beaudoin et al., 1977) has been modified to speed up recovery and prevent sensitization of mice by components of the gradient which contaminate the sporozoites used as antigen. mouse serum was substituted for bsa in the gradient because the latter produced hypersensitivity. best results were obtained with gradients consisting of medium 199, renografin and mouse serum. heavy and light solution of gradient c ...197939127
stage-selective inhibition of rodent malaria by cyclosporine.the relative susceptibility of different developmental stages of plasmodium berghei to cyclosporine was investigated in vivo. within 12 h of receiving a single 25-mg/kg (body weight) dose of cyclosporine, mice with patent p. berghei infections uniformly exhibited a rapid fall in asexual parasite stages. initially, ring forms and mature schizonts disappeared. subsequently, trophozoites disappeared between 21 and 24 h, whereas gametocytes persisted for 36 h. in contrast, when cyclosporine was admi ...19883288113
antilymphocyte autoantibody in lethal mouse malaria and its suppression by non-lethal malaria.mice infected with lethal p. berghei or p. yoelii malaria develop anti-lymphocyte autoantibodies less than a week after infection. the autoantibodies are igm, t-dependent and cytotoxic to a subpopulation of non-t lymphocytes at 37 degrees c in the presence of mouse or guinea-pig complement. non-lethal p. yoelii and p. chabaudi do not induce these autoantibodies. x-irradiated p. berghei parasites induce autoantibodies in normal mice but not in mice infected with non-lethal p. yoelii suggesting an ...19836346230
acidic phosphoproteins associated with the host erythrocyte membrane of erythrocytes infected with plasmodium berghei and p. chabaudi.new phosphoproteins appear on the host erythrocyte membrane during plasmodium berghei and p. chabaudi infection. distinct proteins having similar properties and all distinguished by isoelectric points of less than 4.0 are identified. associated with the erythrocyte membranes of p. berghei infected erythrocytes are two proteins with molecular masses of 65 and 46 kda, whereas 93, 90 and 76 kda proteins are observed during p. chabaudi infection. these new erythrocyte membrane associated proteins ar ...19883278220
plasmodium falciparum: purification, properties, and immunochemical study of ornithine decarboxylase, the key enzyme in polyamine biosynthesis.ornithine decarboxylase, the rate-limiting enzyme in the polyamine biosynthetic pathway has been purified 7,600 fold from plasmodium falciparum by affinity chromatography on a pyridoxamine phosphate column. the partially purified enzyme was specifically tagged with radioactive dl-alpha-difluoromethylornithine and subjected to polyacrylamide gel electrophoresis under denaturing conditions. a major protein band of 49 kilodalton was obtained while with the purified mouse enzyme, a typical 53 kiloda ...19883139441
impaired immune responsiveness in plasmodium berghei immune mice.mice immunized against plasmodium berghei parasites by drug-controlled infection exhibited decreased immunoresponsiveness against rabbit red blood cells (rrbc). increasing rrbc antigen dose increased responsiveness, but agglutinating anti-rrbc antibodies of the igg class remained undetectable. clearance of colloidal carbon from the bloodstream of malaria-immunized mice was not different from controls. removal of all the persistent parasites from immune mice did not restore responsiveness until 1 ...19892531361
[test of cross immunity in 3 strains of plasmodium berghei of different virulence in mus musculus cured of infection using thermal stress (+35 degrees c)]. 19862428277
antimalarial activity of a 4',5'-unsaturated 5'-fluoroadenosine mechanism-based inhibitor of s-adenosyl-l-homocysteine hydrolase.a 4',5'-unsaturated 5'-fluoroadenosine inhibitor of s-adenosyl-l-homocysteine hydrolase (sah hydrolase; ec 3.3.1.1), mdl 28842, was found to inhibit markedly the growth of plasmodium falciparum in vitro and plasmodium berghei in mice. inhibition of p. berghei growth was associated with a large increase in the concentration of s-adenosyl-l-homocysteine (sah) in the erythrocytes of the mice treated with mdl 28842. this increase in sah was due apparently to inhibition of the mouse erythrocyte sah h ...19902200410
differences in susceptibility among mouse strains to infection with plasmodium berghei (anka clone) sporozoites and its relationship to protection by gamma-irradiated sporozoites.three inbred mouse strains, c57bl/6 (h-2b), a/j (h-2a), and balb/c (h-2d), and 1 outbred strain, cd-1, demonstrated differences in susceptibility to iv challenge with the anka clone of plasmodium berghei. mice were challenged with 100, 1,000, or 10,000 sporozoites, then evaluated daily beginning on day 4 for patency. cd-1 mice were further evaluated at challenge doses of 12,500, 25,000, and 50,000 sporozoites. c57bl/6 mice were the easiest to infect, with 90% becoming infected with 100 sporozoit ...19902184689
ribosomal rna sequences of sarcocystis muris, theileria annulata and crypthecodinium cohnii reveal evolutionary relationships among apicomplexans, dinoflagellates, and ciliates.sarcocystis muris is a coccidium with a two-host life cycle involving the domestic cat and the mouse, mus musculus. s. muris and theileria annulata belong to the phylum apicomplexa, but the latter organism is a tick-borne protozoon in the subclass piroplasmea and causes tropical theileriosis in cattle. the small-subunit ribosomal rna (16s-like rrna) coding regions of these organisms as well as that of the free living dinoflagellate crypthecodinium cohnii were amplified using polymerase chain rea ...19911904987
incorporation of t and b epitopes of the circumsporozoite protein in a chemically defined synthetic vaccine against malaria.we show here an effective and novel approach to engineer peptide-based vaccines using a chemically defined system, known as multiple peptide antigen systems (maps), to protect an inbred mouse strain from infection against rodent malaria. 10 mono- and di-epitope map models containing different arrangements and stoichiometry of functional b and/or t helper cell epitopes from the circumsporozoite protein of plasmodium berghei were used to immunize a/j mice. while these mice did not respond to the m ...19901688609
the relationship of phosphorylation of membrane proteins with the osmotic fragility and filterability of plasmodium berghei-infected mouse erythrocytes.membrane from plasmodium berghei-infected mouse erythrocytes showed a pattern of protein phosphorylation which was substantially altered from the normal pattern, with an increase in the phosphorylation of the protein with an apparent molecular weight of 43,000 (m 43), which increased from undetectable in uninfected cells to a maximum in the mature trophozoite stage. phosphorylation levels of this and other minor bands were strongly correlated with osmotic fragility and filterability. the level o ...19873300785
modulator effect of toxoplasma lysate antigen in mice experimentally infected with plasmodium berghei.normal mice were pretreated twice at an interval of 2 weeks with an emulsion of tla (toxoplasma lysate antigen), pla (plasmodium lysate antigen) or both in lmo (light mineral oil) or with a combination of the emulsion and obioactin or tp-lks (toxoplasma lymphokines) as an immunopotentiator. they were then given obioactin or tp-lks 3 and 25 days after the first treatment and were further given parasitized erythrocytes with 1 x 10(2)-10(4) p. berghei 2 weeks after the second treatment. thirty (3/1 ...19873310463
the establishment of plasmodium berghei in mosquitoes of a refractory and a susceptible line of anopheles atroparvus.the events between the ingestion of plasmodium berghei-infected mouse blood and the establishment of the ookinetes in the epithelium of the midgut in refractory (r) and susceptible (s) anopheles atroparvus are described. simultaneously fed, fully engorged female mosquitoes were randomly assigned to dissection at 22, 28, 32, 48 h and 10 days (controls) after the infective feed (post-infection: p.i.). serial transverse sections of 6 micron were cut. every 10th section was studied. the maturation o ...19863521118
sialic acid analysis and tritium-labelling of sialoglycoproteins of mouse erythrocytes infected with plasmodium berghei.schizont-infected red blood cells (si-rbc) from plasmodium berghei-infected mice contain between 2 and 10 times as much sialic acid as uninfected rbc from the same blood (99-550 micrograms/10(10) rbc versus 33-65 micrograms/10(10) rbc). total rbc samples from infected animals containing up to 63% ring- and trophozoite-infected cells had identical sialic acid contents to purified rbc samples (of less than 3% parasitaemia) from the same blood (52-64 micrograms/10(10) rbc). we conclude that rbc con ...19863526260
[probable loss of chloroquine resistance in plasmodium berghei inoculated in mus musculus previously irradiated with sublethal doses (300 r) of x-rays]. 19863530088
[activity of 2 aminoglycoside antibiotics in plasmodium berghei infection in mus musculus]. 19863530089
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 ...19957695303
identification of distinct accumulation sites of 4-aminoquinoline in chloroquine sensitive and resistant plasmodium berghei strains.we report the synthesis of an analogue of chloroquine (cqa) which can be used as a probe to visualize accumulation of 4-aminoquinoline by electron microscopy. a mouse monoclonal antibody against cqa was raised and used for immunodetection by the protein-a gold method on ultrathin cryosections, of cqa treated parasites. we demonstrate that in a p. berghei chloroquine(cq)-sensitive strain (n strain) the chloroquine analogue used accumulates in the endocytic vacuoles where hemoglobin (hb) degradati ...19863545836
plasmodium berghei: oxidant defense system.glutathione oxidant defense system protects the erythrocyte from oxidative damage. this defense system was studied in mouse erythrocytes infected with plasmodium berghei and in isolated parasites. the efficiency of this system was found to be increased in parasitized erythrocytes compared to the normal erythrocytes. the increase in the components of the oxidant defense system in the parasitized cells could result from parasitic addition to these components. this defense system present in the par ...19853908136
plasmodium berghei infection in mice. an ultrastructural study of immune complex nephritis.renal glomeruli of plasmodium berghei infected mice were studied electron microscopically. the endothelial cell proliferation and endothelial cytoplasmic changes were greatly stimulated on day 7, at the time when there were collections of dense granular aggregates in the glomerular capillary lumens and electron-dense deposits in the mesangial areas. the basement membrane lesion developed with the infiltration of polymorphonuclear leucocytes on day 14 with more electron-dense deposits in the mesa ...19734264779
[interferon and protection of the mouse against experimental infestation transmitted by the erythgrocytic forms of plasmodium berghei injected in massive doses. ii. effects of several immunosuppressive agents on protection patterns by a viral interferon inducer]. 19734771733
the effect of antisera to normal rat and mouse erythrocytes on the infectivity of plasmodium berghei. 19694987046
plasmodium berghei nk65 in the inbred a-j mouse: variations in virulence of p. berghei demes. 19715133123
a statistical evaluation of synergism of folic acid antagonists on experimental plasmodium berghei mouse infection. 19685703765
identification of circumsporozoite proteins in individual malaria-infected mosquitoes by western blot analysis.circumsporozoite (cs) proteins of rodent (plasmodium berghei), simian (p. knowlesi), and human (p. falciparum) malaria parasites extracted from dead and dried mosquitoes have been identified by the western blot (immunoblot) technique. dried mosquitoes which were laboratory-reared and infected with plasmodium or freshly dissected sporozoites were triturated in sample reducing buffer and the extracts electrophoresed in a 10% sds-polyacrylamide gel. after transferring the proteins to nitrocellulose ...19846145742
anti-red blood cell autoantibodies induced in rat by plasmodium berghei infection bind to a cross-reacting determinant present also in other cell types.it has been previously shown that rats injected with red blood cells (rbc) infected with plasmodium berghei make autoantibodies reacting with normal rat rbc as demonstrated by a staphylococcal protein a binding assay. in this study, the serum of the infected rats was found to contain also antibodies to several other types of rat cells (lymphoid, liver, and kidney cells and brain tissue) as well as against rbc and lymphoid cells of mice and sheep, but not of man. rat, mouse, and sheep rbc and rat ...19836191899
enhanced ca2+ uptake by mouse erythrocytes in malarial (plasmodium berghei) infection.erythrocytes from plasmodium berghei-infected mice on incubation either in plasma or artificial isotonic media showed an increase in uptake of 45ca2+ compared with erythrocytes from uninfected mice. infected cells (55% parasitaemia) incubated in plasma from normal or infected mice gave uptake rates of 9.8 and 8.1 nmol h-1 per 10(10) cells, assuming equilibrium between added 45ca2+ and plasma ca2+. uptake rates of erythrocytes from infected mice were increased in the presence of glucose, with a r ...19836350870
[effects of anti-infectious immunomodulators in leprosy and malaria in the mouse].immunomodulators, whether natural (polysaccharides) or industrial (non-hemolytic detergents) proved active by themselves, in preventive or curative schemes of experimental leprosy and malaria. however, their activity was most often increased, through joint administration with chemotherapeutic agents.19836370479
enhancement of phagocytosis of parasitized and nonparasitized red cells in acute plasmodium berghei malaria.the phagocytosis by mouse peritoneal macrophages of parasitized red cells (prcs) and nonparasitized red cells (nonprcs) separated from plasmodium berghei infected blood was studied in vitro. peritoneal macrophages from acutely infected mice and normal mice were cultured on coverslips. prcs and nonprcs were fractionated by ficoll density gradient centrifugation from plasmodium berghei infected blood. prcs were fed in triplicate cultures to normal macrophages in normal serum, normal macrophages in ...19846371136
establishment of ancylostoma ceylanicum adult infection in plasmodium berghei-infected albino mice(mus musculus) 19846380028
blood changes and enhanced thromboxane and 6-keto prostaglandin f1 alpha production in experimental acute plasmodium bergei infection in hamsters.golden hamsters inoculated intraperitoneally with plasmodium bergei infected mouse blood regularly developed p. bergei parasitaemia. this was associated with progressive thrombocytopenia and leucocytosis as the degree of parasitaemia increased with time. when infected whole blood was stimulated with collagen, significantly enhanced thromboxane b2 (txb2) production per platelet was seen. 6-keto prostaglandin (pg) f1 alpha formation in the same system increased from the sixth infection day onwards ...19846388013
2-acetylpyridine thiosemicarbazones. 10. 2-propionyl-, 2-butyryl-, and 2-(2-methylpropionyl)pyridine thiosemicarbazones as potential antimalarial agents.in view of the antimalarial properties observed for many 2-acetylpyridine thiosemicarbazones, a series of n4,n4-disubstituted thiosemicarbazones derived from 2-propionyl-, 2-butyryl-, and 2-(2-methylpropionyl)pyridine was prepared for evaluation against the malaria parasite, plasmodium berghei, in the mouse. the thiosemicarbazones were made by the reaction of methyl hydrazinecarbodithioate with a 2-acylpyridine to give the intermediate methyl 3-[1-2-pyridinyl)alkylidene]hydrazinecarbodithioates. ...19846397197
chemiluminescence response of peritoneal macrophages to parasitized erythrocytes and lysed erythrocytes from plasmodium berghei-infected mice.the chemiluminescence response of normal mouse peritoneal macrophages to parasitized erythrocytes isolated from mice 3 weeks after infection with plasmodium berghei was examined. only 4 of 12 animals showed positive responses, whereas 8 showed negative responses. photomicrographs revealed that only in chemiluminescence-positive animals were parasitized erythrocytes attached to or phagocytized by macrophages. when lysed parasitized-erythrocyte cell suspensions were added to the peritoneal macroph ...19826749686
sporozoites of mammalian malaria: attachment to, interiorization and fate within macrophages.sporozoites of plasmodium berghei and plasmodium knowlesi, incubated in normal serum readily interact with peritoneal macrophages of mice or rhesus monkeys, respectively. interiorization of the sporozoite requires that both serum and macrophages be obtained from an animal susceptible to infection by the malaria parasite. serum requirements for sporozoite attachment to the macrophage are less specific. phagocytosis is not essential for the parasites to become intracellular. our findings indicate ...19806772771
[interaction of chloroquine with ferriprotophorphyrin ix. nuclear magnetic resonance study].chloroquine is still the antimalarial drug which is the most utilized. nevertheless the molecular mode of action of this drug is not very well understood. when mouse erythrocytes injected with plasmodium berghei are exposed to chloroquine, the first biochemical event is rapid accumulation of the drug. this process is energy dependent, saturable and competitively inhibited by drugs of the same therapeutic class (quinine, amodiaquine, mefloquine). receptors for chloroquine have been proposed for t ...19826818999
enhanced fusion capacity of malaria (plasmodium berghei)-infected mouse red cells.the capacity of normal and malaria-infected mouse red cells to undergo fusion was investigated by phase contrast microscopy. the fusion of mouse red cells induced by 50% w/w poly(ethylene glycol)-6000 in the presence of ca+2 is enhanced by p. berghei infection. cells carrying parasites in the ring form stage and early trophozoite stage show slightly higher fusion induced by dimethyl sulphoxide and ca+2 than those carrying parasites in trophozoite and schizont stages.19806998573
folate antagonists. 18. synthesis and antimalarial effects of n6-(arylmethyl)-n6-methyl-2,4,6-pteridinetriamines and related n6,n6-disubstituted 2,4,6-pteridinetriamines.n6-(arylmethyl)-n6-methyl-2,4,6-pteridinetriamines (1-15) and related n6-substituted 2,4,6-pteridinetriamines (16-20) were obtained by the condensation of 6-chloro-2,4-pteridinediamine with n-methylarylmethanamine and other selected secondary amines. the requisite n-methylarylmethanamines (21-32) were prepared by the hydrogenation over pt/c of the corresponding arylcarboxaldehyde in the presence of methanamine. several of the n6-(arylmethyl)-n6-methyl-2,4,6-pteridinetriamines exhibited exception ...19817009868
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 ...19817035641
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 ...19937508418
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 ...19957558142
experimental cerebral malaria: possible new mechanisms in the tnf-induced microvascular pathology.in order to contribute to the prevention of malaria morbidity and mortality, especially in endemic zones, we have carried out a series of studies on cytokine interactions in an experimental model of cerebral malaria (cm). this rapidly lethal syndrome develops, in some strains of mice, upon infection with plasmodium berghei anka (pba). a crucial mediator of neurovascular lesions appears to be tnf, found in high amounts in relation with cerebral complications, in both experimental and human cm. in ...19957900436
use of specific polyclonal antibodies for site specific drug targeting to malaria infected erythrocytes in vivo.the possibility of using specific polyclonal antibodies for effective site specific drug targeting to malaria infected erythrocytes has been examined. for this purpose, rabbit polyclonal antiserum was raised against plasmodium berghei infected mouse erythrocytes (irbc) and extensively absorbed with normal erythrocytes (nrbc). absorbed antiserum specifically recognized irbc. f(ab')2-fragments of these antibodies were coupled to chloroquine (chq) laden liposomes. these immunoliposomes when tested ...19938005626
effects of plasmodium berghei (apicomplexa) on nippostrongylus brasiliensis (nematoda) infection in the mouse, mus musculus.ova and free oxygen radical production and relative peripheral eosinophilia during single and concurrent infections in mice with p. berghei and n. brasiliensis were investigated. prolonged helminth patent periods indicate that nippostrongylus self-cure in concurrently infected mice was suppressed. differential white blood cell determinations showed that the relative number of peripheral blood eosinophils steadily increased (p < or = 0.05) during a nippostrongylus infection when compared to nonin ...19948070956
immunomodulation by morphine in plasmodium berghei-infected mice.the effect of morphine on immunomodulation and host defense have been investigated during plasmodium berghei infection in balb/c mice. a single low (5.0 mg/kg) subcutaneous dose of morphine strongly suppressed (sometimes completely eliminated) the parasitaemia, whereas a high dose (80.0 mg/kg) exerted mild potentiating effect. mice treated with the low dose showed a significant (p < 0.05) increase in the total number of circulating leukocytes, the number (pool-size) of peritoneal macrophages, an ...19948289594
comparisons between microvascular changes in cerebral and non-cerebral malaria in mice, using the retinal whole-mount technique.cba/t6 mice inoculated with plasmodium berghei anka strain (pba) exhibited cerebral symptoms and died from cerebral malaria 6-8 days p.i. whereas dba/2j mice developed (around days 6-9) a non-fatal cerebral malaria, with milder cerebral symptoms, and died between days 15 and 22 from other malaria-related complications. when inoculated with p. berghei k173 (pb) these mouse strains did not develop cerebral malaria. these mouse/parasite strain combinations were used, in conjunction with the retinal ...19938295787
plasmodium berghei: is nitric oxide involved in the pathogenesis of mouse cerebral malaria?to analyze whether nitric oxide may be involved in the pathogenesis of the mouse cerebral malaria (cm), nitrate and nitrite were first measured in urines of plasmodium species infected mice. the cm-susceptible cba/j mice were infected with either plasmodium berghei or plasmodium chabaudi, and the cm-resistant balb/c mice were infected with p. berghei. no increased levels of nitrate and nitrite were detected in urine of mice infected with plasmodium whatever the time of monitoring. in contrast, t ...19938344400
plasmodium berghei: sensitivity of chloroquine-resistant and chloroquine-sensitive strains to irradiation and the effect of irradiated malaria parasites on cytochrome p450-dependent monooxygenases.differences in sensitivities of chloroquine-sensitive and chloroquine-resistant strains of plasmodium berghei were observed following irradiation of the parasites. a dose of 15 kilorads from a cobalt-60 source killed the erythrocytic stages of the chloroquine-sensitive strain and no parasitemias were observed when mice were injected with these irradiated parasites. in contrast, when the chloroquine-resistant strain was irradiated with the same dose of cobalt-60 and injected into mice, an infecti ...19958581351
mitochondrial nadh dehydrogenase from plasmodium falciparum and plasmodium berghei.the mitochondrial electron transport system is necessary for growth and survival of malarial parasites in mammalian host cells. nadh dehydrogenase of respiratory complex i was demonstrated in isolated mitochondrial organelles of the human parasite plasmodium falciparum and the mouse parasite plasmodium berghei by using the specific inhibitor rotenone on oxygen consumption and enzyme activity. it was partially purified by two sequential steps of fast protein liquid chromatographic techniques from ...200211971654
trafficking of plasmodium chabaudi adami-infected erythrocytes within the mouse spleen.plasmodium chabaudi adami causes a nonlethal infection in mice. we found that crisis, the time of rapidly dropping parasitemia, was abrogated by splenectomy, indicating the role of spleen in parasite killing. the factors that mediate spleen-dependent immunity are not known. an earlier study in plasmodium berghei-infected rats showed an association between increased clearance of heat-treated erythrocytes and the onset of crisis [wyler, d. j., quinn, t. c. & chen, l.-t. (1982) j. clin. invest. 67, ...19968643449
[effect of formate on mouse erythrocytes in vivo and in vitro].the effect of formiat was tested in erythrocytes of mice damaged by oxidisation. decrease of heinz's bodies, stabilisation of reduced glutathion, and increase of enzyme activities by referring to an example of superoxidismutase could be identified as a positive effect. possibilities of formiat reactions in the metabolism of red blood cells are discussed.19836200395
plasmodium berghei: infectivity of mice to anopheles stephensi mosquitoes.the infectivity of p. berghei-infected to mice to mosquitoes declines rapidly 2 to 5 days after blood inoculation, in spite of rising numbers of gametocytes in the blood. this pattern is typical of many malaria infections and various factors, particularly specific and nonspecific immune responses, have previously been implicated in the decline. here we report that (1) simple physiological changes in the mouse blood, namely, falling ph and bicarbonate levels induced by high parasitaemias, are res ...19968948326
early activation of microglia in the pathogenesis of fatal murine cerebral malaria.microglia are pluripotent members of the macrophage/monocyte lineage that can respond in several ways to pathological changes in the central nervous system. to determine their role in the pathogenesis of fatal murine cerebral malaria (fmcm) we have conducted a detailed study of the changes in morphology and distribution of retinal microglia during the progression of the disease. adult cba/t6 mice were inoculated with plasmodium berghei anka. these mice died 7 days post inoculation (p.i.) with th ...19979034826
the roles of temperature, ph and mosquito factors as triggers of male and female gametogenesis of plasmodium berghei in vitro.developmentally arrested malarial gametocytes undergo gamete formation in the mosquito midgut immediately after ingestion of the infected bloodmeal. in the rodent malaria parasite plasmodium berghei male gametogenesis (exflagellation) can be induced in vitro by a temperature decrease (from 39 degrees c in the vertebrate host to 20 degrees c) and a concomitant ph increase (from 7.3 in mouse blood to 8.0). we report the presence of additional gametocyte activating factor(s) (gaf) present in anophe ...19979280891
partial purification and characterization of a murine malaria parasite, plasmodium berghei specific aldolase.cell-free p. berghei contains 26.1 times more aldolase activity as compared to normal mouse erythrocytes. subcellular fractionation of cell-free parasite showed maximum enzyme activity in the soluble fraction. the parasite enzyme was active in a narrow ph range of 7.8-8.0. of the enzyme activity 90% was lost within 2 weeks at 4 degrees c. slight inhibition was observed with specific inhibitors atp, pyrophosphate (ppi) and pep. the f1, 6dp km was 0.025 mm.19979394614
reduced t helper 1 responses in il-12 p40 transgenic mice.to investigate the antagonistic effect of il-12 p40 on il-12 activity in vivo, we generated transgenic (tg) mice in which p40 gene was regulated by a liver-specific promoter. three tg mouse lines were generated, and they expressed the p40 transgene predominantly in liver. serum p40 level was extremely high, and it consisted of mainly monomer and homodimer and also of higher m.w. complexes. these tg mice did not show any apparent phenotypic difference from control littermates in lymphoid cells. e ...19989551892
cloned lines of plasmodium berghei anka differ in their abilities to induce experimental cerebral malaria.infection with plasmodium berghei anka is usually lethal. the parasite causes in some mouse strains a neurovascular syndrome, experimental cerebral malaria (ecm), involving immunopathological reactions. the effects on the development of ecm of the mouse genetic background have been clearly demonstrated, but nothing is known about the effects of the clonal diversity of the parasite. we showed that various cloned lines derived from a polyclonal line of p. berghei anka caused ecm but that the exten ...19989712753
treatment with recombinant human tumour necrosis factor-alpha reduces parasitaemia and prevents plasmodium berghei k173-induced experimental cerebral malaria in mice.the present study shows that treatment with recombinant human tumour necrosis factor-alpha (rhtnf-alpha) can suppress parasitaemia and prevents development of experimental cerebral malaria (ecm) in plasmodium berghei k173-infected mice. mice received rhtnf-alpha treatment either by subcutaneous injection of free or liposome-encapsulated rhtnf-alpha or sustained intraperitoneal administration of rhtnf-alpha given via mini-osmotic pumps. low-dose treatment with a subcutaneous bolus injection of rh ...199910070656
gamma interferon production is critical for protective immunity to infection with blood-stage plasmodium berghei xat but neither no production nor nk cell activation is critical.we have examined the roles of gamma interferon (ifn-gamma), nitric oxide (no), and natural killer (nk) cells in the host resistance to infection with the blood-stage malarial parasite plasmodium berghei xat, an irradiation-induced attenuated variant of the lethal strain p. berghei nk65. although the infection with p. berghei xat enhanced nk cell lytic activity of splenocytes, depletion of nk1.1(+) cells caused by the treatment of mice with anti-nk1.1 antibody affected neither parasitemia nor ifn ...199910225894
role of eicosanoids in the pathogenesis of murine cerebral malaria.because microvascular damage is a common feature of cerebral malaria, we have examined the role eicosanoid metabolites (prostaglandins and leukotrienes) in experimental cerebral malaria. eighty icr mice were infected with plasmodium berghei anka, with 40 uninfected mice as controls. half of the infected mice were treated on days 4 and 5 with aspirin, a prostaglandin synthesis inhibitor. infected mice started to die of cerebral malaria on day 6, and by day 17, all infected mice died. in contrast, ...199910348246
an alternate pathway for type 1 t cell differentiation.ifn-regulatory factor-1 (irf-1) gene-disrupted mice are defective in il-12 and il-18 gene expression at the transcriptional and post-translational level respectively. the mutant mouse mounts a type 2 t cell response upon bacterial infection because of the impaired induction of the il-12 p40 gene and ifn-gamma-producing type 1 t cells are not induced. we showed here, however, that different pathogens activate a novel pathway for inducing ifn-gamma-producing type 1 t cells even in an irf-1-deficie ...199910421776
novel, potent, semisynthetic antimalarial carba analogues of the first-generation 1,2,4-trioxane artemether.ten novel, second-generation, fluorinated ether and ester analogues of the potent first-generation analogues artemether (4a) and arteether (4b) have been designed and synthesized. all of the compounds demonstrate high antimalarial potency in vitro against the chloroquine-sensitive hb3 and -resistant k1 strains of plasmodium falciparum. the most potent derivative 8 was 15 times more potent than artemisinin (2) against the hb3 strain of p. falciparum. in vivo, versus plasmodium berghei in the mous ...199910639291
enumeration of micronucleated reticulocytes in rat peripheral blood: a flow cytometric study.micronuclei (mn) are routinely enumerated in mouse peripheral blood to index genotoxicity. recent data from the collaborative study group for the micronucleus test (csgmt) [csgmt (the collaborative study group for the micronucleus test), evaluation of the rat micronucleus test with bone marrow and peripheral blood: summary of the 9th collaborative study by csgmt/jems mms, environ. mol. mutagen. 32 (1998) 84-100] suggest that rat peripheral blood may also be appropriate for the enumeration of mn, ...200010708974
direct immunization of malaria dna vaccine into the liver by gene gun protects against lethal challenge of plasmodium berghei sporozoite.the liver is the first target organ for malaria parasites immediately after the bite of an infected mosquito. we studied local immunization of malaria dna vaccines at the site of the liver using a gene gun as a useful tool for in vivo transfection of foreign genes. a malaria dna vaccine consisting of the plasmodium berghei circumsporozoite protein (pbcsp) gene plus the mouse il-12 gene was bombarded directly by a gene gun into mouse liver once or into the skin twice. a marked protective effect w ...200010777689
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 ...200010932227
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 ...200111349050
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 ...200111379040
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 ...200011388501
competitive relationship between eperythrozoon coccoides and plasmodium berghei in the mouse. 196514281212
[dietetic influence on malaria (plasmodium berghei) in the mouse]. 196414340331
[effect of various diets on the development of plasmodium berghei in the white mouse]. 195514393134
plasmodium berghei infection in mice induces liver injury by an il-12- and toll-like receptor/myeloid differentiation factor 88-dependent mechanism.malaria, caused by infection with plasmodium spp., is a life cycle-specific disease that includes liver injury at the erythrocyte stage of the parasite. in this study, we have investigated the mechanisms underlying plasmodium berghei-induced liver injury, which is characterized by the presence of apoptotic and necrotic hepatocytes and dense infiltration of lymphocytes. although both il-12 and il-18 serum levels were elevated after infection, il-12-deficient, but not il-18-deficient, mice were re ...200111698470
Displaying items 1 - 100 of 177