| intrasplenic immunization with infected hepatocytes: a mouse model for studying protective immunity against malaria pre-erythrocytic stage. | malaria liver forms are the target of antibody or t-cell-mediated immune mechanisms induced by previous or subsequent developmental stages of the parasite. the potential for vaccine development of antigens expressed exclusively in the liver stages has not been fully explored partly because of the lack of an experimental animal model. here we show that protective immunity against sporozoite-induced infection with plasmodium yoelii and p. berghei can be obtained by intrasplenic injection of a smal ... | 1994 | 7913914 |
| the immunomodulating effect of a new polyamine (the map-1987) administered with chloroquine in plasmodia infected mice. | the biological activity of a new synthetic polypeptide, the map-1987 was proved in the rodent malaria system. the administration of 4 micrograms/kg of map-1987 prevents the haemolysis of the plasmodium berghei infected erythrocytes but not the plasmodium vinckei infected ones. the map-1987 given alone changes neither the survival time of the infected mice nor the rate of parasitaemia. the chloroquine given alone increases the survival time of the mice infected with p. berghei under the standardi ... | 1994 | 7921853 |
| picroliv affects gamma-glutamyl cycle in liver and brain of mastomys natalensis infected with plasmodium berghei. | picroliv, the standardized preparation of iridoid glycosides from picrorhiza kurrooa, at the dose of 6 mg/kg, po for two weeks provided significant protection against depletion of reduced glutathione levels in liver and brain of plasmodium berghei infected mastomys natalensis. the activation of gamma-glutamyl transpeptidase enzyme and decreased levels of cysteine, sulphydryl groups as well as glutathione synthesis in both tissues due to p. berghei infection were reversed by picroliv. enzymatic a ... | 1994 | 7927525 |
| susceptibility of different strains of mice to hepatic infection with plasmodium berghei. | despite the low susceptibility of balb/c mice to hepatic infection by plasmodium berghei, this animal model is routinely used to investigate the basic biology of the malaria parasite and to test vaccines and the immune response against exoerythrocytic (ee) stages derived from sporozoites. a murine model in which a large number of ee parasites are established would be useful for furthering such investigations. therefore, we assayed six mouse strains for susceptibility to erythrocytic and hepatic ... | 1994 | 7927764 |
| effect of plasmodium berghei infection and antimalarial treatment on heme synthesis in mice. | plasmodium berghei infection impaired the hepatic heme synthesizing machinery of mice. key enzymes, viz. s-aminolevulinic acid synthase, s-aminolevulinic acid dehydrase and ferrochelatase were found to be decreased. in contrast, tryptophane pyrrolase noticeably increased during parasitic infection. oral feeding of chloroquine [16 mg (kg body weight)-1 x 4 days] cleared the parasitaemia from infected mice within 72 h and returned the altered levels of enzymes almost to normal a week after cessati ... | 1994 | 7928069 |
| [a comparative restriction analysis of the dna of strains of the malarial parasite sensitive and resistant to chloroquine]. | a comparative restriction analysis was made for dna in malaria parasites, strain h sensitive to chloroquinone, strain lnk-65 with spontaneously occurred resistance to the agent, and breeding strain lnk-65 chlr highly resistant to it. dna hydrolysis with ecor1, hindiii, and bamh1 endonucleases revealed permanent differences in the dna restriction pattern of malaria parasites. there were additional restriction bands as part of dna restricts in the strain lnk-65 chl bred from lnk-65 for high resist ... | 1994 | 7935181 |
| in vitro development of infectious liver stages of p. yoelii and p. berghei malaria in human cell lines. | the preerythrocytic stages of the malaria parasite are the focus of intense efforts to identify new immunological and pharmacological methods for the control of the malaria parasite. the study of the malaria hepatic stages requires an in vitro system to facilitate the analysis of parasite/host cell interactions and the characterization of exoerythrocytic form (eef) antigens. at the present time, only the rodent malaria, plasmodium berghei, and the human malaria, plasmodium vivax, develop into ma ... | 1994 | 7957756 |
| effect of malaria infection on the pharmacokinetics of paracetamol in rat. | 1. paracetamol (p; 50 and 300 mg/kg i.v.) was administered to the control and malaria-infected (mi) male wistar rat in order to assess the effect of mi on the metabolism of paracetamol to its glucuronide (pg) and sulphate (ps) conjugates and their excretion in urine. 2. at a dose of 50 mg/kg, neither total clearance (clt) (controls, 20.3 +/- 0.5; mi, 19.9 +/- 0.9, ml/min/kg; mean +/- sd, p > 0.05) nor the renal clearance of p (clr) were affected by mi. although the formation clearance of pg (clf ... | 1994 | 7975718 |
| [synthesis and biological activities of 2,4-diamino-5-fluoro-6-substituted benzylamino quinazolines]. | the title compounds were synthesized by condensation of 5-fluoro- 2, 4, 6-triaminoquinazoline (6a) with various substituted benzaldehydes to produce the corresponding schiff bases, followed by reduction. ii and iii were obtained by formylation and nitrosation of i, respectively, iv were obtained by reduction of ii. primary screening for suppressive therapeutic effects against p. berghei in mice showed that six of the twenty-two compounds produced 100% suppression when administered orally at a do ... | 1994 | 7976341 |
| [synthesis of 4-methyl-5-substituted phenoxy-primaquine analogues and preliminary evaluation on their antimalarial activity]. | on basis of our previous work, seven 4-methyl-5-substituted phenoxy-6-methoxy-8-(1-methyl-4-amino-butylamino)-quinolines (ii2-8) were synthesized and their antimalarial activities were preliminarily evaluated. the target compounds were prepared from 2-nitro-4-methoxy-5-bromo-acetanilide as previously described. the structures of ii2-8 and all of the unknown intermediates were confirmed by elementary and spectral analyses. preliminary biological evaluation revealed that all of ii2-8 exhibited sig ... | 1994 | 7976342 |
| sexual development of malaria parasites is inhibited in vitro by the neem extract azadirachtin, and its semi-synthetic analogues. | we have shown that azadirachtin, a compound from the neem tree, azadirachta indica, and selected semi-synthetic derivatives, block the development of the motile male malarial gamete in vitro. changes in the hemiacetal group at position c11 in the molecule result in a loss of activity in this assay. the motility of fully formed male gametes, and other selected flagellated cells, is unaffected by azadirachtin in vitro. these findings raise the possibility of developing azadirachtin-based compounds ... | 1994 | 7980823 |
| antimalarial activity of wr 243251, a dihydroacridinedione. | wr 243251 is a dihydroacridinedione that was evaluated for antimalarial blood schizonticidal activity in vitro and in vivo. the in vitro doses calculated to kill 50% of organisms were 11 nm for a chloroquine-susceptible, mefloquine-resistant standard strain and 25 nm for a chloroquine- and pyrimethamine-resistant standard strain. the total dose needed to cure 100% of mice infected with a drug-susceptible strain of plasmodium berghei was 12 to 20 mg/kg of body weight for both oral and subcutaneou ... | 1994 | 7986005 |
| enzymatic amplification of lactate dehydrogenase-elevating virus. | to improve the detection of lactate dehydrogenase-elevating virus (ldv), we developed a pcr assay. primers were selected from orf7, encoding nucleocapsid protein vp1. no specific amplification was observed with any other common murine virus or with rnas from the closely related lelystad virus and equine arteritis virus. in experimentally infected mice, ldv could be detected in plasma in both the acute and the persistent phases. ldv was also detected by the pcr in contaminated pools of plasmodium ... | 1994 | 7989557 |
| the small ribosomal subunit rna isoforms in plasmodium cynomolgi. | we report the isolation, characterization and analysis of the small subunit rrna genes in plasmodium cynomolgi (ceylon). as in other plasmodium species, these genes are present in low copy number, are unlinked and form two types that are distinct in sequence and are expressed stage specifically. the asexually expressed (type a) genes are present in four copies in the ceylon- and in five copies in the berok-strain. surprisingly, the sexually expressed (type b) gene is present in a single copy. th ... | 1994 | 8005440 |
| 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 ... | 1993 | 8005626 |
| regular initiation of translation of plasmodium berghei aldolase-2 after pre-mrna splicing. | in plasmodium falciparum aldolase a uag or a regular aug codon has been proposed for the initiation of ribosomal protein synthesis. a uag codon present at the beginning of the coding sequence of the aldolase 2 gene (aldo-2) of plasmodium berghei is not recognised in vitro as an initiation codon, which suggests addition of a regular aug codon by mrna splicing. sequence analysis of cdna amplified by the reversed polymerase chain reaction reveals addition of an atg codon with a splice donor consens ... | 1994 | 8008025 |
| inhibitory action of the anti-malarial compound atovaquone (566c80) against plasmodium berghei anka in the mosquito, anopheles stephensi. | the activity of atovaquone against plasmodium berghei anka during sporogonic development has been examined. anopheles stephensi mosquitoes were fed on gametocyte infected mice which had been treated 8 h previously with atovaquone or diluent alone. mosquito midguts were examined for oocysts, and salivary gland infections were estimated using an elisa for the circumsporozoite protein (csp). the number of oocysts per midgut fell by at least 97% when mosquitoes were fed on mice dosed with 0.1-10 mg ... | 1994 | 8008451 |
| [effect of spermidine on uptake of chloroquine by plasmodium berghei]. | to probe into the effect of spermidine on chloroquine (chl) uptake by p berghei and its role of chl-resistance, mice infected with chl sensitive strain (cs) of p berghei were given chl 20 mg.kg-1 ig combined with spermidine (spe) 42 mg.kg-1 ip. it was found that 3 and 16 h after combined administration, chl quantity uptaken by the parasites was reduced respectively by 59.6% and 53.8% in comparison with that in the chl group. however, there was no difference in parasitaemia between chl group (2.3 ... | 1993 | 8010037 |
| antimalarial activity of dihydroartemisinin derivatives by transdermal application. | in addition to artelinic acid, which was demonstrated previously to possess good prophylactic as well as curative antimalarial activity against plasmodium berghei by transdermal administration, seven artemisinin derivatives in a gel formulation were assessed for their antimalarial activities in this study. artemisinin, the parent compound of the series, showed moderate prophylactic but poor curative activity. although methyl artelinate was more active against p. berghei than artelinic acid and s ... | 1994 | 8024074 |
| hemoglobins from plasmodium-infected rat erythrocytes: functional and molecular characteristics. | aiming to evaluate the mechanisms responsible for altered o2-transporting properties in blood of plasmodium-infected animals, stripped (cofactor-free) hemoglobin (hb) solutions were prepared from infected erythrocytes (ie) and noninfected erythrocytes (nie) of rats inoculated with plasmodium berghei bergei for functional and structural characterization. at normal intraerythrocytic ph (+/- 7.2), hb from ie showed a higher affinity, a larger bohr effect, and lower sensitivities to 2,3-diphosphogly ... | 1994 | 8025289 |
| remarkable activation of polyamine biosynthesis in hematopoiesis and hyperplasia of spleen in mice with hemolytic anemia caused by infection with plasmodium berghei. | ornithine decarboxylase (odc) activity was markedly induced in the spleen of mice infected with plasmodium berghei, showing maximal activity at 8 days after the infection. the increase of spleen weight, on the other hand, reached its peak after 14 days of infection. in the blood of p. berghei-infected mice, no increase of odc activity was observed. this indicated that odc was induced in the spleen cells, but not in the parasites themselves which existed in the blood. polyamines (putrescine, sper ... | 1994 | 8026898 |
| characterization of the effector mechanisms of a transmission-blocking antibody upon differentiation of plasmodium berghei gametocytes into ookinetes in vitro. | the transmission-blocking monoclonal antibody 13.1, which recognizes the ookinete surface antigen pbs21 of plasmodium berghei, and an igg2a isotype control antibody 26.37 were purified by caprylic acid and ammonium sulphate precipitation. fab fragments were prepared by papain digestion. igg but not fab from antibody 13.1 reduced ookinete formation by p. berghei in culture by as much as 94% at a concentration of 100 micrograms/ml. there was little difference in antibody efficacy in the range 6.25 ... | 1994 | 8058360 |
| murine aids protects mice against experimental cerebral malaria: down-regulation by interleukin 10 of a t-helper type 1 cd4+ cell-mediated pathology. | the retrovirus lp-bm5 murine leukemia virus induces murine aids in c57bl/6 mice that has many similarities with human aids; plasmodium berghei anka causes experimental cerebral malaria in the same strain of mice. the outcome of malaria infection was studied in mice concurrently infected with the two pathogens. the retrovirus significantly reduced the gravity of the neurological manifestations associated with plasmodium berghei anka infection. the protection against experimental cerebral malaria ... | 1994 | 8058763 |
| plasmodium sporozoites possess both positively and negatively charged sites accessible on their surface. | studies were conducted on the distribution of anionic and cationic sites on the surface of intact plasmodium berghei and p. yoelii sporozoites. anionic and cationic ferritins were used as probes for electron microscope studies and fluorescein conjugates of the same charged ferritins were used for correlative studies by fluorescence light microscopy. we found that the surfaces of mature sporozoites from mosquito salivary glands possess both negatively and positively charged sites that are accessi ... | 1994 | 8064519 |
| 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 ... | 1994 | 8070956 |
| experiments on the possible role of leeches as vectors of animal and human pathogens: a light and electron microscopy study. | the presence and survival of pathogens inside the gut of leeches were studied by means of light and electron microscopy. in african leeches from cameroon, blood was serologically positive for human immunodeficiency virus (hiv) and hepatitis b; blood of hirudo medicinalis bought in german pharmacies contained up to 11 different species of bacteria. in experiments done at low (3 degrees c) and high (22 degrees, 32 degrees c) temperatures, it was shown that ingested red and white blood cells surviv ... | 1994 | 8073013 |
| [purification and isolation of different stages of plasmodium vivax, p. falciparum and p. berghei]. | the present paper reported the results of purification and isolation of different stages of p. vivax, p. falciparum and p. berghei by percoll gradient centrifugation after removal of leukocytes (wbcs) by passing the blood suspension through cf-11 cellulose columns. 94.7% and 75.4% of wbcs from the patients' blood of vivax malaria and the mice blood infected with p. berghei respectively were removed with no alteration of the parasite density and the malaria stage ratio after the cellulose filtrat ... | 1993 | 8082264 |
| comparison of in vivo and in vitro antimalarial activity of artemisinin, dihydroartemisinin and sodium artesunate in the plasmodium berghei-rodent model. | the in vitro and in vivo antimalarial activity of artemisinin, artesunate and dihydroartemisinin has been compared using the plasmodium berghei-rodent model. drugs were added to synchronized short-term in vitro cultures of the erythrocytic stages and inhibition of parasite development was determined by measuring dna synthesis by flow cytometry. dihydroartemisinin was the most effective drug. ic50 values of artemisinin, artesunate and dihydroartemisinin were 1.9, 1.1 and 0.3 x 10(-8) m, respectiv ... | 1994 | 8082988 |
| possible isozyme-specific effects of experimental malaria infection with plasmodium berghei on cytochrome p450 activity in rat liver microsomes. | we have investigated the effect of experimental malaria infection on rat cytochrome p450-mediated drug metabolism using ethoxyresorufin and metoprolol as probe compounds. malaria infection caused a significant reduction in total intrinsic clearance of ethoxyresorufin in both low and high parasitaemia malaria compared with control (control 18.7 +/- 7.2; low parasitaemia 10.5 +/- 4.1; high parasitaemia 4.3 +/- 1.4 ml min-1). however, clearance of metoprolol was unchanged in malaria infection compa ... | 1994 | 8083805 |
| picosecond fluorescence spectroscopy of a single-chain class i major histocompatibility complex encoded protein in its peptide loaded and unloaded states. | the tryptophan fluorescence properties of two different peptide complexes of the single-chain h-2kd (sc-kd) were studied by means of the single-photon counting technique. the latter enables time-resolved measurements of fluorescence intensity and anisotropy decay parameters relevant to structural and dynamic properties of proteins. while the isolated sc-kd molecules in their 'original' purified form represent the unloaded state, i.e., containing endogenous low-affinity peptides, the loaded sc-kd ... | 1994 | 8088870 |
| the transcript encoding the circumsporozoite antigen of plasmodium berghei utilizes heterogeneous polyadenylation sites. | we have employed polymerase chain reaction-based techniques to examine the transcript encoding the circumsporozoite (cs) antigen, the immunodominant coat protein of the infectious stage of the murine parasite plasmodium berghei. earlier studies suggested that the 3' terminus of the cs message might be determined by transcription termination rather than by cleavage and polyadenylation, as in most eukaryotes. here we report that a subset of cs messages are polyadenylated. moreover, the poly(a) tai ... | 1993 | 8093973 |
| detection of polymorphisms among theileria parva stocks using repetitive, telomeric and ribosomal dna probes and anti-schizont monoclonal antibodies. | a total of 21 theileria parva stocks from 6 countries were characterized using t. parva repetitive and ribosomal dna probes, a plasmodium berghei telomeric oligonucleotide and a panel of anti-schizont monoclonal antibodies (mabs). hybridization of the repetitive dna probe to southern blots of ecori-digested t. parva dna revealed 20 different restriction fragment patterns among dna samples isolated from infections initiated using 16 parasite stocks. the panel of anti-schizont mabs defined 8 diffe ... | 1993 | 8102796 |
| effect of nifedipine on calcium status and chemiluminescence response of phagocytes during plasmodium berghei infection in mice. | the macrophages and neutrophils from nifedipine-treated mice, both plasmodium berghei-infected and uninfected, showed suppressed capacity to generate oxygen free radicals as compared with untreated controls. nifedipine treatment did not affect resting state free calcium levels in these cells. but the rise in intracellular calcium levels of macrophages and neutrophils following p. berghei infection was significantly less (p < 0.05) in nifedipine-treated mice as compared with untreated groups at v ... | 1993 | 8103102 |
| does antiarrhythmic magnesium therapy enhance malarial infection? | | 1993 | 8105332 |
| effect of pyrimethamine resistance on sporogony in a plasmodium berghei/anopheles stephensi model. | a pyrimethamine-resistant line of plasmodium berghei was derived by treating infected mice with high doses of pyrimethamine and selecting for recrudescence. this resistant line was compared with the parental pyrimethamine-sensitive line in order to ascertain whether drug resistance is associated with a biological advantage. overall, the pyrimethamine-resistant line is quite similar to the sensitive line, except that it proceeds through sporogonic development more slowly than the pyrimethamine-se ... | 1994 | 8119374 |
| photoaffinity labeling of the t cell receptor on cloned cytotoxic t lymphocytes by covalent photoreactive ligand. | the interaction of the t cell antigen receptor with a photoreactive antigenic peptide derivative bound covalently to the h-2kd (kd) molecule was studied by photoaffinity labeling on cloned, cd8 positive cytotoxic t lymphocytes. the kd-restricted plasmodium berghei circumsporozoite peptide 253-260 (yips-aeki) was conjugated with iodo-4-azidosalicylic acid at the n terminus and with 4-azidobenzoic acid at the t cell receptor residue lys-259. cell-associated or soluble kd molecules were photoaffini ... | 1994 | 8119892 |
| the chemotherapy of rodent malaria. li. studies on a new 8-aminoquinoline, wr 238,605. | wr 238,605, a novel 3-phenoxy-substituted 8-aminoquinoline, possesses causal prophylactic, blood schizontocidal and gametocytocidal activity against rodent malaria parasites. against the asexual, intra-erythrocytic stages of drug-sensitive plasmodium berghei n strain, it is about nine times as active as primaquine (pq). it is from four to 100 times as active as pq against lines of p. berghei or p. yoelii that are resistant to currently used antimalarials. wr 238,605 is three times as active as p ... | 1993 | 8122915 |
| screening of coptis teeta wall. for antimalarial effect: a preliminary report. | | 1993 | 8131885 |
| role of polymorphonuclear neutrophil leukocytes and their integrin cd11a (lfa-1) in the pathogenesis of severe murine malaria. | infection of cba mice with plasmodium berghei anka results in severe malaria, which is characterized by mortality 6 to 10 days after infection and is associated with alterations of the brain microcirculation. these alterations consist of (i) intravascular sequestration of monocytes, (ii) an increase in vascular permeability as documented by evans blue diffusion, and (iii) microhemorrhages. this syndrome may be due to an increase of production of tumor necrosis factor alpha which upregulates the ... | 1994 | 8132319 |
| metabolism of caffeine and theophylline in rats with malaria and endotoxin-induced fever. | 1. the effects of malaria infection due to plasmodium berghei and escherichia coli endotoxin-induced fever on the metabolism of orally-administered caffeine (ca: 10 mg/kg) to its primary metabolites (theobromine (tb), paraxanthine (px) and theophylline (th)) were studied in 5-week-old male wistar rats (n = 5 for each treatment). in separate experiments, the effects of malaria and endotoxin-induced fever on the clearance of i.v.-administered theophylline (th; 15 mg/kg) were studied in another gro ... | 1993 | 8135041 |
| effect of dietary iron on the course of plasmodium berghei malaria in young rats. | clinical and experimental evidence suggests that iron-deficient hosts are less susceptible to severe malaria and that iron supplementation aggravates infection. in the present study, 60 weanling wistar rats were fed standard diets with different iron concentrations: 21 mg/kg (group 1), 45 mg/kg (group 2) and 113 mg/kg (group 3). ferrous sulfate (feso4 x 7h2o) was added to the normal-iron and iron-supplemented diets (groups 2 and 3, respectively). data are reported as mean +/- sem. after 16 days ... | 1993 | 8136731 |
| studies on the immunogenicity of a recombinant ookinete surface antigen pbs21 from plasmodium berghei expressed in escherichia coli. | plasmodium berghei ookinete surface antigen (pbs21), was produced as a fusion product with maltose binding protein (mbp) in escherichia coli and used to induce transmission-blocking immunity in mice. specificity of induced antibody was confirmed by western blotting with native ookinete pbs21, and by the indirect immunofluorescent antibody test on ookinete bloodfilms. immunized mice were infected with p. berghei and transmission to anopheles stephensi mosquitoes determined by both the intensity a ... | 1994 | 8152832 |
| demonstration of heat-shock protein 70 in the sporozoite stage of malaria parasites. | three monoclonal antibodies generated by immunization of mice with plasmodium berghei-infected red blood cells were found to react with the 75-kda heat-shock protein (hsp70) present in liver stages and erythrocytic forms of the parasites. these antibodies were shown to react with a recombinant protein encoding the carboxyl terminal half of pfhsp70 (aa 365-681). differently from earlier results, we clearly demonstrated that hsp70 was also expressed in the sporozoite stage, using these monoclonal ... | 1994 | 8153120 |
| plasmodium berghei: the use of discontinuous urografin density gradients for the separation of exoerythrocytic malaria parasites. | urografin was used in the lower cushion of discontinuous density gradient systems, for the separation of human hepatoma cells (hep g2) infected with exoerythrocytic p. berghei forms from uninfected cells. the hepatoma cells exhibited a rather heterogeneous density distribution, masking the possible density differences between infected and uninfected cells and hindering the efficient separation of both cell types. purely osmotic damage caused by urografin on human erythrocytes and hepatoma cells ... | 1993 | 8154784 |
| requirements for glycosylphosphatidylinositol attachment are similar but not identical in mammalian cells and parasitic protozoa. | the general features of the glycosylphosphatidylinositol (gpi) signal have been conserved in evolution. to test whether the requirements for gpi attachment are indeed the same in mammalian cells and parasitic protozoa, we expressed the prototype gpi-linked protein of trypanosoma brucei, the variant surface glycoprotein (vsg), in cos cells. although large amounts of vsg were produced, only a small fraction became gpi linked. this impaired processing is not caused by the vsg ectodomain, since repl ... | 1994 | 8163550 |
| new, antimalarial, tricyclic 1,2,4-trioxanes: evaluations in mice and monkeys. | we have concluded initial preclinical studies with synthetic trioxanes numbered 3-9 and have compared them with artemisinin (numbered 1) using cd-1 mice infected with plasmodium berghei. based on their antimalarial effectiveness in mice, two of these synthetic trioxanes were selected for evaluation in aotus monkeys infected with multidrug-resistant (mdr) p. falciparum. trioxane numbered 8 (12 and 48 mg/kg), trioxane numbered 9 (12 and 48 mg/kg) and arteether (numbered 2, 48 mg/kg) were administe ... | 1994 | 8166360 |
| aminopeptidases from plasmodium falciparum, plasmodium chabaudi chabaudi and plasmodium berghei. | using fluorogenic substrates and polyacrylamide gels we detected in cell-free extracts of plasmodium falciparum, plasmodium chabaudi chabaudi and plasmodium berghei only a single aminopeptidase. a comparative study of the aminopeptidase activity in each extract revealed that the enzymes have similar specificities and kinetics, a near-neutral ph optima of 7.2 and are moderately thermophilic. each has an apparent molecular weight of 80,000 +/- 10,000, determined by high performance liquid chromato ... | 1994 | 8167617 |
| [studies on residual antimalarial activity of tripynadine in mice and monkeys]. | this paper reports the experiments in which tripynadine free base at a dose 4.5 times that of ed50 was given to mice by intragastric administration. on the 20th day following the administration the mice were inoculated with 1 x 10(7) rbc infected with plasmodium berghei anka strain. the infection rate was zero, implying that all mice had acquired protection. although the residual activity time of tripynadine phosphate was longer than that of tripynadine free base or piperaquine phosphate, but tr ... | 1993 | 8168241 |
| characterization and pathological significance of monoclonal dna-binding antibodies from mice with experimental malaria infection. | malaria infection is accompanied by the production of a number of autoantibodies, including some that react with dna. epidemiological evidence implicates these in the nephritides that arise in human quartan malaria and in experimental malaria infections in mice. through parallels with the involvement of dna-reactive antibodies in the autoimmune syndrome systemic lupus erythematosus, a role for dna-reactive antibodies in forming phlogistic immune deposits in the kidneys is implied. to more fully ... | 1994 | 8168966 |
| [immunoelectron-microscopic localization of a 54-kda protein overexpressed by chloroquine-resistant plasmodium berghei anka strain]. | a 54-kda protein overexpressed by chloroquine-resistant plasmodium berghei anka strain was first reported by us. in this paper, the localization of this protein by immunoelectron microscopy is presented. the results showed that the protein was mainly scattered inside the cytoplasm of the early, late trophozoites and schizonts of erythrocytic stage of p. berghei anka strain, and some of it was also found in cytoplasm of erythrocytes infected with parasites. the protein content was much higher in ... | 1993 | 8174210 |
| [fluidity of red blood cell membrane from mouse infected with malaria parasite]. | the fluidity of membrane lipid regions of plasmodium berghei- or plasmodium yoelii-infected red blood cells has been determined by the fluorescence polarization technique using 1,6-diphenyl-1,3,5-hexatriene (dph) as a probe. the results showed that the fluidity of plasmodium (berghei or yoelii)-infected red blood cell membranes was increased significantly as compared with that of normal controls judging from the degree of polarization and the microviscosity. its mechanism was discussed briefly. | 1993 | 8174215 |
| efficient in vivo induction of ctl by cell-associated covalent h-2kd-peptide complexes. | a novel procedure is presented describing the induction of antigen-specific cytolytic t lymphocytes (ctl) in vivo, that uses as immunogen syngeneic concanavalin a stimulated spleen cells expressing h-2kd (kd) molecules photocrosslinked with a photoreactive peptide derivative. the kd restricted plasmodium berghei circumsporozoite (pbcs) peptide 253-260 (yipsaeki) was conjugated with photoreactive iodo-4-azidosalicylic acid (iasa) at the nh2-terminus and with 4-azidobenzoic acid (aba) at the tcr c ... | 1994 | 8176239 |
| synthesis and in vitro evaluation of 9-anilino-3,6-diaminoacridines active against a multidrug-resistant strain of the malaria parasite plasmodium falciparum. | a series of 9-anilinoacridines have been prepared and evaluated for their activity against a multidrug-resistant k1 strain of the malaria parasite plasmodium falciparum in erythrocyte suspensions. 3,6-diamino substitution on the acridine ring resulted in lower mammalian cell cytotoxicity and higher antiparasitic activity than other substitution patterns, providing compounds with the highest in vitro therapeutic indices. a new synthesis of 3,6-diamino-9-anilinoacridines, via reduction of the corr ... | 1994 | 8182707 |
| in vivo activity of ajoene against rodent malaria. | ajoene (4,5,9-trithiadodeca-1,6,11-triene 9-oxide), a product initially isolated from extracts of garlic (allium sativum), was tested for its antimalarial activity in vivo in a well-characterized murine model. a single ajoene dose of 50 mg/kg, on the day of infection, suppressed the development of parasitemia; there were no obvious acute toxic effects from the tested dose. the combination of ajoene (50 mg/kg) and chloroquine (4.5 mg/kg), given as a single dose on the day of the infection, comple ... | 1994 | 8192460 |
| t lymphocyte-dependent development of cerebral symptoms in wm/ms rats infected with plasmodium berghei. | | 1994 | 8192520 |
| effects of hormones and cysteine protease modulators on infection of hepg2 cells by plasmodium berghei sporozoites in vitro determined by elisa immunoassay. | an enzyme-linked immunosorbent assay (elisa) detecting a plasmodium berghei liver-stage-specific protein pbl-1 is described. the quantitative detection limits ranged from 0.01 to 0.05 microgram of parasite protein. qualitatively the assay detected as little as 0.001 microgram pbl-1 per well. using the elisa dexamethasone and insulin together was shown to promote higher parasite infections in hepg2 cells compared to unsupplemented medium. anti-cowpea-protease cysteine inhibitor significantly incr ... | 1994 | 8195943 |
| prevention of sporogony of plasmodium falciparum and p. berghei in anopheles stephensi mosquitoes by transmission-blocking antimalarials. | the sporontocidal activity of three 8-aminoquinolines, a 1,4-naphthoquinone, and three dihydroacridine-diones was determined against the anka clone of plasmodium berghei and both chloroquine-sensitive (nf54) and chloroquine-resistant (7g8) p. falciparum. anopheles stephensi mosquitoes previously fed on p. berghei--infected mice or p. falciparum--infected cultures were refed on uninfected mice treated previously with a given drug. sporontocidal activity was determined by assessing both oocyst and ... | 1994 | 8203716 |
| oxygen transport properties in malaria-infected rodents--a comparison between infected and noninfected erythrocytes. | this study was performed to investigate oxygen transport properties in whole blood (wb) of malaria-infected rats as well as in infected erythrocytes (ie) and noninfected erythrocytes (nie) separated by density centrifugation. one week after inoculation with plasmodium berghei, mean parasitemia was 26.5% and high correlations were found between parasitemia and hemoglobin concentration ([hb]; r = -.902), mean cellular hb concentration (mchc; r = -.712), methb (r = .923), and base excess (r = -.922 ... | 1994 | 8204895 |
| the effect of transmission-blocking antibody ingested in primary and secondary bloodfeeds, upon the development of plasmodium berghei in the mosquito vector. | the effects of purified monoclonal immunoglobulins from control, or transmission-blocking anti-pbs21 antibodies, upon the infection of anopheles stephensi by ookinetes of plasmodium berghei are compared. anti-pbs21 antibody reduced mean intensity and prevalence of infection by 94.7 and 58.7% respectively if added to the infectious bloodfeed at a concentration of 100 micrograms/ml. fab fragments were of similar efficacy. no transmission enhancement was detected with declining antibody concentrati ... | 1993 | 8233585 |
| the design of original antimalarial drugs. an example of phospholipid metabolism. | the aim of our program was to find an original chemotherapeutical treatment (and eventually a preventive treatment) of malaria, an illness largely predominant in developing countries, by interfering on an essential metabolism developed by plasmodium during its erythrocytic phase. apart from what has been learnt about metabolism and the pharmacological target, a crucial step has been taken during this contract by passing from micromolar in vitro active concentrations (during 1986-1990) to nanomol ... | 1993 | 8233602 |
| mobile repeat units in plasmodium berghei. | | 1993 | 8233609 |
| the role of the host during the development of plasmodium berghei hepatic schizonts. | immature exoerythrocytic stages of plasmodium berghei are immunogenic and produce antigens with protective capacities. immunization experiments show a strong dependency of the responses on the host species and strain. to study this dependency a potential natural host of plasmodium berghei, thamnomys gazellae, was introduced, a species which is very susceptible for infection. young liver stages were produced in different hosts after inoculation with irradiated sporozoites or after treatment with ... | 1993 | 8233610 |
| genome organization, chromosome translocation and size polymorphism in rodent malaria parasites. | in our laboratory, rodent malaria models are used to investigate processes that underlie cell differentiation with specific emphasis on sexual development. the rodent parasite plasmodium berghei is particularly suited for this research since the different sexual stages (from young gametocytes to mature ookinetes) can be obtained pure and in large numbers. | 1993 | 8233613 |
| chromosomal polymorphism and sexual differentiation in plasmodium. | the correlation observed in several instances between the loss of ability to produce gametocytes and chromosomal rearrangements, prompted us to investigate in further detail the molecular bases of chromosomal polymorphism in plasmodium. generation of polymorphic karyotypes in plasmodium involves important rearrangements, mostly occurring in subtelomeric position. detailed analysis on the organisation of these regions have been carried out on the rodent malaria p. berghei and the human malaria p. ... | 1993 | 8233621 |
| altered course of plasmodium berghei infection by nifedipine treatment. | the effect of nifedipine (a calcium channel blocker) on the course of p. berghei infection was examined. it was observed that mice receiving a daily dose of 0.015 mg/kg of nifedipine had significantly shorter prepatent, patent and survival periods as compared to untreated p. berghei-infected animals (p < 0.001). this shows that the calcium channel blockers, in addition to possessing the property of reversing drug resistance during combined therapy with chloroquine, may also alter the pathophysio ... | 1993 | 8240785 |
| activity of doxycycline against preerythrocytic malaria. | | 1993 | 8245561 |
| antimalarial activity from 'mhekara' (uapaca nitida müll-arg.), a tanzanian tree. | an aqueous decoction of the root bark of uapaca nitida müll-arg. is currently used locally at the benedictine mission at peramiho in tanzania to treat malaria. we have now demonstrated that extracts of root bark and leaves of this tree are active against the multidrug-resistant k1 strain of plasmodium falciparum in vitro. an ethanolic extract of root bark showed activity against p. berghei in mice but at a dose which also showed toxic effects. the use of this plant in treating malaria appears to ... | 1993 | 8246530 |
| [effect of quinolones on mice experimental infection by plasmodium berghei and their possible therapeutic usefulness]. | the search for new antimalarial drugs is important for many reasons, specially because of the resistance of plasmodia. some clinical and laboratory studies have recently indicated that quinolones, currently in use for treatment of bacterial infections, have antimalarial activity. so, we evaluated the possible action of ciprofloxacin, norfloxacin, ofloxacin and pefloxacin in mice experimentally infected by plasmodium berghei, by the oral route. taking into account parasitemia and mortality, we ca ... | 1993 | 8248700 |
| inhibition of malaria parasite development in mosquitoes by anti-mosquito-midgut antibodies. | the mosquito midgut plays a central role in the development and subsequent transmission of malaria parasites. using a rodent malaria parasite, plasmodium berghei, and the mosquito vector anopheles stephensi, we investigated the effect of anti-mosquito-midgut antibodies on the development of malaria parasites in the mosquito. in agreement with previous studies, we found that mosquitoes that ingested antimidgut antibodies along with infectious parasites had significantly fewer oocysts than mosquit ... | 1994 | 8262645 |
| phagocytosis of malaria-infected erythrocytes in rodent malaria. | | 1993 | 8266248 |
| accessibility and distribution of intraerythrocytic antigens of plasmodium-infected erythrocytes following mild glutaraldehyde fixation and detergent extraction. | malarial antigens on the surface of infected erythrocytes have been described by many investigators. however, few of these antigens have been unambiguously demonstrated to be exposed on the surface of erythrocytes. this study demonstrates that mild glutaraldehyde fixation results in the cytoplasmic face of the host membrane becoming accessible to antibody under conditions that normally do not expose the cytoplasmic face of uninfected erythrocytes. these results indicate that caution should be us ... | 1993 | 8278340 |
| dissociation of the peptide/mhc class i complex: ph dependence and effect of endogenous peptides on the activation energy. | dansylated peptides were used to characterize the dissociation of peptides from a recombinant class i major histocompatibility complex protein. dissociation of endogenous, low-affinity peptides from the class i molecule kd had an activation energy of 6.78 +/- 0.64 kcal/mol in the 14 to 26 degrees c temperature range, but there was a break in the arrhenius plot between 12 and 14 degrees c. dissociation of a dansylated, high-affinity peptide had an activation energy of 20.24 +/- 1.69 kcal/mol, and ... | 1993 | 8280136 |
| [synthesis of pyronaridine related compounds and comparison of antimalarial activities]. | the paper reports the synthesis of pyronaridine (i) related compounds ii-v for exploring whether the antimalarial activity of pyronaridine is by virtue of a nitrogen atom at position 1 in the ring and a pair of pyrrolidinyl mannich base side chains in its structure. the condensation of 2-methoxy-6,9-dichloroacridine or 4,7-dichloro-1,5-naphthyridine with 4-hydroxy-3,5-bis-(pyrrolidinyl-1'-methyl) aniline yielded the related compound ii, 1-deazapyronaridine, or v, 5-azabispyroquine, respectively. ... | 1993 | 8285067 |
| 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 ... | 1994 | 8289594 |
| amelioration of murine cerebral malaria by dietary restriction. | cba/t6 strain mice infected with plasmodium berghei anka develop cerebral symptoms and die, with mononuclear cell attachment to the cerebral microvascular endothelium, petechial haemorrhages and breakdown of the blood-brain barrier, some 6-7 days post-inoculation. the effects of dietary restriction on this process were examined. mice were fed ab libitum (group 1) or their food was restricted to produce body weight loss of 1.0-2.0% (group 2), 2.5-3.5% (group 3), 4.0-6.5% (group 4) or 7.0-9.5% (gr ... | 1993 | 8295786 |
| 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 ... | 1993 | 8295787 |
| plasmodium berghei: serum-mediated inhibition of infectivity of infected mice to anopheles stephensi mosquitoes. | the transmission of plasmodium berghei-infected mice to anopheles stephensi mosquitoes showed a peak number of oocysts early in the infection prior to the peak of gametocytaemia. this was followed by a precipitous decline on days 4 and 5 (see also dearsley et al., parasitology, 100, 359-368, 1990). by measuring percentage relative infectivity (using membrane feeds with viable gametocytes), we have shown that serum collected daily during the course of a blood-induced infection blocked infectivity ... | 1994 | 8299757 |
| role of macrophages in experimental malaria: i. development of immunobioassay indicators. | the role of macrophages in immunogenic mechanisms of malaria was studied. the first part of the study aimed at development of indicators for assessing immunobioassay. accordingly, data on the natural course of lethal plasmodium berghei infection in mice were collected, and baseline estimates of a set of indicators were made. the indicators along with their estimated means are: prepatent period (pp), 2.57 +/- 0.06 days; survival period (sp), 17.63 +/- 0.29 days; median survival day (msd), 17.20 d ... | 1993 | 8319812 |
| enhancement of drug susceptibility in plasmodium falciparum in vitro and plasmodium berghei in vivo by mixed-function oxidase inhibitors. | a number of compounds, as exemplified by verapamil and desipramine, have been shown to enhance the susceptibility of resistant malaria parasites to chloroquine. the mechanism by which these agents reverse resistance is still controversial but is though to involve alterations in drug transport causing an increase in steady-state drug concentrations. we have proposed that an alternative resistance mechanism may involve the metabolic deactivation of the drug in some resistant parasites via cytochro ... | 1993 | 8328780 |
| molecular cloning and localization of an abundant novel protein of plasmodium berghei. | screening of plasmodium berghei genomic libraries using dna insert corresponding to the 3' half of p. falciparum 70-kda heat shock protein gene identified several abundant clones which represent a novel gene in the parasite. the complete sequence was obtained using an approach based on inverse polymerase chain reaction. analysis of the deduced amino acid sequence revealed the presence of 19 imperfect repeats of the sequence gly-gly-met-pro toward the carboxy terminus. except for the similar sequ ... | 1993 | 8341321 |
| structure and expression of a post-transcriptionally regulated malaria gene encoding a surface protein from the sexual stages of plasmodium berghei. | the sexual stage-specific protein pbs21 of the rodent malaria parasite plasmodium berghei, expressed on the surface of zygotes and ookinetes, has been shown to induce an effective and long-lasting transmission blocking immunity. the gene encoding pbs21 was cloned by screening a cdna library prepared from enriched zygotes and ookinetes using the monoclonal antibody 13.1.15, which is capable of blocking subsequent parasite sexual development in the mosquito vector. the pbs21 gene encoded a protein ... | 1993 | 8341324 |
| isolation from a plasmodium chabaudi chromosome 7 specific library of a novel gene encoding a protein with multiple ggmp repeats homologous to hsp70. | | 1993 | 8341330 |
| heterogeneity in patterns of malarial oocyst infections in the mosquito vector. | oocyst prevalence and intensity have been recorded in 349 laboratory infections of anopheles stephensi with plasmodium berghei. intensity and prevalence of infection are shown to be predictably related. the structure and heterogeneity in the infections has been analysed with the objective of describing the biological mechanisms by which the observed negative binomial oocyst distributions are generated. the analysis has revealed that the most likely processes lie within the population dynamic eve ... | 1993 | 8341579 |
| 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 ... | 1993 | 8344400 |
| the chemotherapy of rodent malaria. xlviii. the activities of some synthetic 1,2,4-trioxanes against chloroquine-sensitive and chloroquine-resistant parasites. part 1: studies leading to the development of novel cis-fused cyclopenteno derivatives. | the new chinese antimalarial blood schizontocide, artemisinin, derived from the plant artemisia annua, displays a high level of activity against polyresistant plasmodium falciparum. several synthetic 1,2,4-trioxanes were examined in a search for compounds that exhibit a similar type of action against drug-resistant parasites. this paper, the first of a series, describes the examination of these trioxanes against drug-sensitive and drug-resistant malaria parasites in a rodent model, using artemis ... | 1993 | 8346987 |
| the chemotherapy of rodent malaria. xlix. the activities of some synthetic 1,2,4-trioxanes against chloroquine-sensitive and chloroquine-resistant parasites. part 2: structure-activity studies on cis-fused cyclopenteno-1,2,4-trioxanes (fenozans) against drug-sensitive and drug-resistant lines of plasmodium berghei and p. yoelii ssp. ns in vivo. | the activity of 51 synthetic cis-fused cyclopenteno-1,2,4-trioxanes has been examined against drug-sensitive and chloroquine-resistant malaria parasites in vivo. some of them display high levels of blood schizontocidal activity when administered orally or subcutaneously. they retain their activity against lines of parasites that are resistant to widely differing antimalarials such as 4-aminoquinolines, aminoalcohols, dihydrofolate reductase inhibitors and artemisinin. the most potent compound of ... | 1993 | 8346994 |
| control of heme polymerase by chloroquine and other quinoline derivatives. | to evaluate the response of heme polymerase to treatment of malaria with chloroquine, we used mice infected with plasmodium berghei. six hours after treatment with 3 mumoles of chloroquine intraperitoneally per mouse, heme polymerase activity in parasitized erythrocytes decreased from 238 to 37 nanomoles of ferriprotoporphyrin ix polymerized per hour per mumole of ferriprotoporphyrin ix in preformed hemozoin, and nonhemozoin ferriprotoporphyrin ix increased in vivo from 40 to 123 nanomoles per m ... | 1993 | 8363618 |
| plasmodium berghei-specific t cells respond to non-processed sporozoites presented by b cells. | the mechanism of malaria protective immunity induced by immunization with radiation-attenuated plasmodium sporozoites (spz) is only partially understood. for example, b and t cell responses specific for the circumsporozoite (cs) protein, a 46 kda spz surface protein, have been characterized; however, events leading to spz-specific t cell activation, i.e., processing and presentation of spz by antigen-presenting cells have not been investigated. in the present study we describe the in vitro analy ... | 1993 | 8370405 |
| plasmodium falciparum sporozoite immunization protects against plasmodium berghei sporozoite infection. | irradiated sporozoites are generally thought to elicit protective immune responses that are parasite stage and species specific. but immunization with plasmodium falciparum sporozoites delivered by the bite of infected mosquitoes protects an average of 60% mice from plasmodium berghei sporozoite infection. protection appears to be specific as p. falciparum sporozoite-immunized mice protected against p. berghei remain susceptible to plasmodium yoelii sporozoite infection. passively transferred im ... | 1993 | 8375482 |
| plasmodium berghei: recombinant interferon-gamma and the development of parasitemia and cerebral lesions in malaria-infected mice. | mice infected with plasmodium berghei k173-parasitized erythrocytes develop severe hypothermia followed by death as a consequence of murine cerebral malaria early in the second week after infection. a single intraperitoneal injection of 10(5) units of ifn-gamma given between day 4 and day 6 postinfection results in a transient decrease of body temperature. no effect on parasitemia and cerebral malaria is obtained by this treatment. daily injections of relatively low doses of ifn-gamma delays the ... | 1993 | 8375490 |
| the scid mouse as a laboratory model for development of the exoerythrocytic stages of human and rodent malaria. | | 1993 | 8375494 |
| the roles of ca2+/calmodulin- and cgmp-dependent pathways in gametogenesis of a rodent malaria parasite, plasmodium berghei. | the induction mechanism of gamete formation (gametogenesis) in a rodent malaria parasite, plasmodium berghei, was investigated using ca2+ antagonists, protein kinase inhibitors and amiloride, an inhibitor of monovalent cation/h+ exchange. treatment with 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (tmb-8, a ca2+ release inhibitor) and w-7/w-66 (calmodulin inhibitors) blocked formation of male gametes by inhibiting dna synthesis from 1.5c to 8c level. in contrast, inhibitors of camp/c ... | 1993 | 8385016 |
| kupffer cell elimination enhances development of liver schizonts of plasmodium berghei in rats. | we investigated the development of exoerythrocytic forms (eef) of plasmodium berghei in livers of normal and macrophage-depleted brown norway rats. macrophages were depleted by use of liposome-encapsulated dichloromethylene diphosphonate. upon inoculation of sporozoites, macrophage-depleted rats had significantly larger numbers of eef than untreated rats. we also investigated the effect of macrophage impairment by silica treatment on the development of eef and confirmed that silica induces a sig ... | 1993 | 8386704 |
| antimalarial activity of azithromycin and erythromycin against plasmodium berghei. | several antibiotics that inhibit protein synthesis on 70s ribosomes, including the macrolide erythromycin, and the azalides azithromycin (zithromax) and cp-63,956, demonstrated antimalarial activity against two strains of plasmodium berghei. in a four-day in vivo test, the azalides were 25-fold more potent than erythromycin against the chloroquine-sensitive p. berghei n strain, and displayed additive effects with chloroquine. this effect was not observed with the erythromycin-chloroquine combina ... | 1993 | 8394660 |
| plasmodium berghei: partial purification and characterization of the mitochondrial cytochrome c oxidase. | mitochondria from a rodent malarial parasite (plasmodium berghei) were successfully purified by differential centrifugation and 22% percoll density gradient separation. the purified mitochondria from the erythrocytic stages of the parasite had a density of 1.05 and were found to be heterogeneous by transmission electron microscopy and rhodamine 123 fluorescence microscopy. three marker enzymes, dihydroorotate dehydrogenase, cytochrome c reductase, and cytochrome c oxidase, were assessed during t ... | 1993 | 8397100 |
| kinetics of expression of two major plasmodium berghei antigens in the mosquito vector, anopheles stephensi. | expression of a 21 kda determinant (pbs21), first detected on the surface of ookinetes, and of the circumsporozoite protein (csp) was studied by immunofluorescence and western blots during the developmental cycle of plasmodium berghei in the mosquito anopheles stephensi. the expression of pbs21 was predominantly localised on the ookinete surface one day after the infectious blood meal, and thereafter reactivity declined to a minimum on days 2 and 3, the time of onset of oocyst development. a gra ... | 1993 | 8401470 |
| [early ultrastructural evolution of murine malaria merozoites after entering red cells]. | a tem study of murine malaria parasites, plasmodium berghei and p. yoelii was performed by consecutive sampling in vivo to look into the early sequential changes in the ultrastructure of the merozoites after entering red cells. the results showed that once finishing invasion, the merozoite resided in the peripheral cytoplasm of the red cell, creating a bulge at the invasion site, with an additional unit membrane around it (parasitophorous vacuole); apical structures disappeared; the spherical bo ... | 1993 | 8403273 |
| effect of nifedipine on oxidative damage of erythrocytes in plasmodium berghei-infected mice. | it is known that the calcium channel blocker (ccb), nifedipine, can inhibit phagocyte oxidative burst in plasmodium berghei-infected mice. the extent of immunopathological changes as seen by the course of infection and membrane lipid peroxidation in nifedipine-treated mice was examined in comparison with untreated mice at different parasite loads. the glutathione antioxidant system was also studied in these animals to assess its capacity to neutralize reactive oxygen species (ros) in infected er ... | 1993 | 8403562 |
| profiles of cytokine production in relation with susceptibility to cerebral malaria. | infection with plasmodium berghei anka (pba) leads, in susceptible strains of mice, to the development of cerebral malaria (cm), a lethal syndrome that reproduces some features of human cm. to study a possible relationship between genetic susceptibility to cm and the cytokine expression pattern, we quantitatively evaluated gene expression on rna extracted from various organs of malaria-infected mice, using strains that are susceptible and resistant to cm. northern blot analysis and semi-quantita ... | 1993 | 8409439 |
| analysis of malarial transcripts using cdna-directed polymerase chain reaction. | a polymerase chain reaction (pcr)-based approach is being employed to study rna transcripts in malarial parasites, a system that is not easily amenable to molecular studies. our aim is to compare messages from different life cycle stages to determine whether regulatory information is encoded in the structure of plasmodial transcripts as a result of differential rna processing. in particular, we have analyzed the structure of the message encoding the circumsporozoite (cs) protein of the murine ma ... | 1993 | 8410535 |