| toward the elucidation of the mechanism of attachment and entry of malaria sporozoites into cells: synthetic polypeptides from the circumsporozoite protein of plasmodium falciparum bind ca2+ and interact with model phospholipid membranes. | through the joint use of cd, fourier transform ir (ftir), and attenuated total reflectance ftir we have found that synthetic polypeptide models of the plasmodium falciparum circumsporozoite (cs) protein repeat domain bind calcium ions in helicogenic environments. ca(2+)-(nanp)n complexes (n greater than or equal to 20) interact vectorially with model phospholipid membranes orienting their polypeptide axes preferentially along those of the lipid acyl chains. it is proposed that the p. falciparum ... | 1991 | 1932559 |
| reduction of the surface-volume ratio: a physical mechanism contributing to the loss of red cell deformability in malaria. | plasmodia and other intraerythrocytic parasites reduce the deformability of the red cells they infect. one mechanism potentially responsible for this reduction in deformability is the decrease in the surface:volume (s/v) ratio of the red cell which occurs with parasite growth. to examine this hypothesis, normal red cells were allowed to phagocytize polylysine-coated latex spheres 1.0 to 2.9 microns in diameter. deformability decreased progressively with spheres of increasing size, consistent wit ... | 1991 | 1932714 |
| [development of a campaign strategy against malaria in a rice-growing region of burundi]. | epidemiological studies undertaken in an area of low altitude in burundi, revealed microgeographic variations of malaria endemicity, naturally unstable in the area. however transmission is relatively high near rice fields. the transmission increases at the end of the rainy season, period of natural decrease of the vector population combined with an increase of their longevity. indoor spraying with short acting insecticides during that period of the year, reduced considerably the transmission and ... | 1991 | 1933066 |
| f-actin bundling protein from physarum polycephalum: purification and its capacity for co-bundling of actin filaments and microtubules. | an f-actin bundling protein was isolated and purified from plasmodium of physarum polycephalum. the f-actin bundling protein in physarum extract was passed through a deae-cellulose column. after the protein in the fraction was treated with 6 m urea, it was purified by gel filtration on sephacryl s-300 hr followed by chromatography on cm-toyopearl (cation exchange) in the presence of 6 m urea. the purified protein gave a single band on sds-page, and the molecular weight was estimated to be 52,000 ... | 1991 | 1934085 |
| susceptibility of plasmodium falciparum to different doses of quinine in vivo and to quinine and quinidine in vitro in relation to chloroquine in liberia. | chloroquine-resistant plasmodium falciparum has been spreading rapidly after its emergence in 1988 in yekepa. the in vivo and in vitro susceptibilities to quinine and quinidine, compared to chloroquine, were studied by investigating the number of treatment days required for radical cure and estimating the quinine concentrations concomitantly. the minimal inhibitory concentrations (mic) for schizont maturation in all successful in vitro tests were 5.12 x 10(-6) mol/l for quinine and 1.28 x 10(-6) ... | 1991 | 1934240 |
| in vivo response of multi-resistant plasmodium falciparum infections to mefloquine and its combination with sulfadoxine/pyrimethamine in cambodia. | | 1991 | 1937278 |
| antibody recognition and isoelectrofocusing of antigens of the malaria parasite plasmodium yoelii. | inbred balb/c mice were either immunized with triton x-100-extracted antigens of blood-stage plasmodium yoelii or infected with p. yoelii and cured in three successive schedules. whereas the immunized balb/c became only partially protected from subsequent challenge infection with blood-stage p. yoelii, the convalescent mice acquired total immunity. when total p. yoelii antigen extract was resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and im ... | 1991 | 1937750 |
| antibodies and dna probes used to analyze variant populations of the indochina-1 strain of plasmodium falciparum. | ten variant populations derived from the indochina-1 strain of plasmodium falciparum were analyzed by using (i) hyperimmune serum raised against some of these populations in squirrel monkeys and (ii) an oligonucleotide probe based on the rep-20 sequence, which had previously been shown to be a useful marker of diversity. although all 10 subpopulations had an identical fingerprint pattern on southern blots probed with the oligonucleotide, thus demonstrating a homogeneous genetic makeup, they all ... | 1991 | 1937756 |
| testosterone-induced abrogation of self-healing of plasmodium chabaudi malaria in b10 mice: mediation by spleen cells. | this study investigates the suppressive effect of testosterone (te) on the self-healing of plasmodium chabaudi malaria in female mice of the strain c57bl/10, and, in particular, the possible role of spleen cells in mediating this te effect. our data show the following. (i) about 80% of b10 mice infected with 10(6) p. chabaudi-infected erythrocytes are capable of self-healing the infections. this capability is progressively impaired and finally abrogated after pretreating the b10 mice with te for ... | 1991 | 1937807 |
| antimalarial effects of peptide inhibitors of a plasmodium falciparum cysteine proteinase. | we previously identified a plasmodium falciparum trophozoite cysteine proteinase (tcp) and hypothesized that it is required for the degradation of host hemoglobin by intraerythrocytic malaria parasites. to test this hypothesis and to evaluate tcp as a chemotherapeutic target, we examined the antimalarial effects of a panel of peptide fluoromethyl ketone proteinase inhibitors. for each inhibitor, effectiveness at inhibiting the activity of tcp correlated with effectiveness at both blocking hemogl ... | 1991 | 1939639 |
| an in vivo chloroquine sensitivity study in relation to low transmission potential and imported malaria in kerala. | the study highlights the presence of chloroquine resistant plasmodium falciparum strains in kerala state, india for the first time. the emergence of chloroquine resistant p. falciparum in a low transmission area is dependent on the imported cases while build up of resistance is mainly due to persistence of resistant parasites which have more opportunities for transmission. | 1991 | 1940213 |
| changing response of plasmodium falciparum to chloroquine in west bengal during 1980-1988. | a total of 314 cases of plasmodium falciparum malaria studied during 1980-88 in nine times monitoring revealed three riii foci i.e. two in jalpaiguri and one in purulia districts. the studies showed a parasite clearance of 40 per cent and 32 per cent of p. falciparum cases within seventh day in purulia and jalpaiguri districts respectively, with a dosage of 25 mg per kg body weight, spread over three days in divided doses. increase in transmission potential and prolonged drug pressure with singl ... | 1991 | 1940214 |
| influence of adjuvants on the antibody specificity to the plasmodium falciparum major merozoite surface protein, gp195. | the effect of adjuvants on the specificity of immune responses to the plasmodium falciparum gp195 protein was investigated using adjuvant formulations based on synthetic muramyl dipeptide and monophosphoryl lipid a derivatives, in parallel with cfa and alum. although these immunomodulators were as effective as cfa in inducing an antibody response to gp195, there were distinct differences in the recognition of b cell epitopes by these antibody populations. we have also demonstrated that mhc contr ... | 1991 | 1940375 |
| preparation of clinical grade proteins produced by recombinant dna technologies. | methods were developed for the production of clinical grade malaria vaccine candidates expressed in e. coli by recombinant dna technologies. the essential features of the purification protocol consist of (1) mechanical breakage of host cells and solubilization of the recombinant proteins in 6 m guanidine hydrochloride; (2) ammonium sulfate fractionation; (3) affinity chromatography on a ni(2+)-chelate gel in the presence of 6 m guanidine hydrochloride; and (4) ion exchange chromatograph on a pho ... | 1991 | 1940392 |
| development of immunity against plasmodium falciparum malaria: clinical and parasitologic immunity cannot be separated. | a total of 1622 individuals of all ages living under conditions of continuous malarial transmission in liberia were enrolled in a cross-sectional study of parasite rates, positive parasite densities, and body temperatures. the age-specific plasmodium falciparum-positive parasite densities were greatest at ages 0.5-1.0 year, then slowly declined into adulthood. the age-specific mean body temperature at parasite isodensity showed a steady decline even in the oldest age group. the results do not su ... | 1991 | 1940474 |
| lysozyme is an inducible marker of macrophage activation in murine tissues as demonstrated by in situ hybridization. | this study demonstrates the induction of lysozyme mrna expression in situ in tissue macrophages (m phi) of mice following in vivo stimulation. the resting resident tissue m phi of most tissues do not contain enough lysozyme mrna to be detected by in situ hybridization using 35s-labeled rna probes. following bacille calmette guerin or plasmodium yoelli infection, however, m phi recruited to liver and spleen hybridize strongly to the lysozyme probe. within 24 h of infection, cells found in the mar ... | 1991 | 1940787 |
| recombinant pfs25 protein of plasmodium falciparum elicits malaria transmission-blocking immunity in experimental animals. | pfs25 is a sexual stage antigen of plasmodium falciparum that is expressed on the surface of zygote and ookinete forms of the parasite. monoclonal antibodies directed against native pfs25 can block completely the development of p. falciparum oocysts in the midgut of the mosquito vector. thus, this 25-kd protein is a potential vaccine candidate for eliciting transmission-blocking immunity in inhabitants of malaria endemic regions. we have synthesized, by secretion from yeast, a polypeptide analog ... | 1991 | 1940798 |
| plasmodium species identification by elisa for sporozoites removed from dried dissection slides. | this study tested the feasibility of identifying salavary gland sporozoites to species by plasmodium falciparum elisa by drying them on slides or in vials. the glands were dissected from anopheles gambiae giles s.l. and an. funestus giles collected in western kenya. in 119 gland infections containing a geometric mean of 1,222 sporozoites, a mean of 72.5% of sporozoites were removed in 60 microliters saline from slides at the time of dissection. each of the 119 samples was divided into three 18 m ... | 1991 | 1941915 |
| a new laboratory technique for malaria diagnosis. | | 1991 | 1942489 |
| antimalarial activity of some plant remedies in use in marracuene, southern mozambique. | two plants, spirostachys africana and bridelia cathartica, were selected for investigation on the basis of a clinical study of four herbal antimalarial remedies used in southern mozambique. petroleum ether, ethanol and aqueous extracts were tested for activity in vitro against plasmodium falciparum. crude ethanolic and aqueous extracts of the root and the ethanolic extract of the stem of b. cathartica caused a 50% inhibition of parasite growth at an incubation concentration of 0.05 microgram/ml. | 1991 | 1943178 |
| studies on the antimalarial mode of action of quinoline-containing drugs: time-dependence and irreversibility of drug action, and interactions with compounds that alter the function of the parasite's food vacuole. | the quinoline-containing antimalarial drugs chloroquine, quinine and mefloquine exert an irreversible inhibitory effect on erythrocytic stages of plasmodium falciparum grown in culture. inhibition is time- and concentration-dependent and the full effect is observed after 2-6 hours of exposure to the drug. washing of infected cells after drug exposure in the presence of nh4cl to accelerate drug efflux, intensifies the inhibitory effect of chloroquine, probably due to the ph-dependent release of h ... | 1991 | 1943436 |
| in vivo and in vitro derived palo alto lines of plasmodium falciparum are genetically unrelated. | the uganda palo alto strain of plasmodium falciparum (fup) is routinely used as a reference isolate in a number of laboratories. it is one of the few p. falciparum strains that can both be propagated in vivo in monkeys and maintained in culture. the palo alto parasites have been characterized for several biochemical and molecular markers, but many of the data reported so far are contradictory. we have analyzed and compared by southern blotting, pcr and dna sequencing, several dna preparations ob ... | 1991 | 1944415 |
| genetic and structural relationships between components of a protective rhoptry antigen complex from plasmodium falciparum. | | 1991 | 1944420 |
| nucleotide sequence variation in the beta-tubulin genes from plasmodium berghei and plasmodium falciparum. | | 1991 | 1944421 |
| [exchange transfusion in cases of falciparum malaria]. | malaria is diagnosed in 50-70 patients each year in norway. severe malarial infection with cerebral involvement as well as hypoglycaemia, circulatory collapse and renal failure is often difficult to diagnose since the condition is only rarely seen in scandinavia. this report describes a 49 year old seaman, who was admitted to hospital with a clinical picture of sepsis with multiorgan involvement including cerebral affection. subsequently, it turned out that the patient had a severe infection wit ... | 1991 | 1945797 |
| a 5-year surveillance of sensitivity in vivo of plasmodium falciparum to pyronaridine/sulfadoxine/pyrimethamine in diaoluo area, hainan province. | the surveillance of sensitivity of p. falciparum to pyronaridine/sulfadoxine/pyrimethamine has been carried out in diaoluo area in hainan province where chloroquine-resistant falciparum malaria is endemic, covering an area of 406 square kilometers, with a population of 3745 in 1986. from 1986 all outpatients diagnosed as falciparum malaria were administered with pnd/s/p as the only antimalarial. in vivo sensitivity of p. falciparum was measured in some patients who were treated in hospital. it w ... | 1991 | 1948261 |
| pharmacokinetics of prophylactic mefloquine in thai healthy volunteers. | malaria constitutes one of the most serious public health problems in thailand. the disease undermines the health of the people and threatens the economy and security of the country as it is most prevalent in the rural region in forested mountain areas along the border where government officials (border police) have to perform their duties. a safe and effective prophylactic drug for use by these government officials is needed. nine healthy border police volunteers who were working on the thai-ca ... | 1991 | 1948262 |
| plasma quinine levels in patients with falciparum malaria when given alone or in combination with tetracycline with or without primaquine. | quinine has been an effective drug for severe chloroquine-resistant falciparum malaria. however, there has been a decline in the sensitivity of plasmodium falciparum to quinine. in 1978-1979 the cure rate was 94% compared to 86% in 1979-1980 and 76% in 1980-1981. the combination of quinine and tetracycline has improved the cure rate to 95-100%. however, the mechanism responsible for this has not been identified. we have compared plasma quinine levels on day 2, day 5 and day 7 (before and at 2 ho ... | 1991 | 1948263 |
| proguanil/sulfamethoxazole malaria chemoprophy-laxis on the thai-cambodian border. | 383 thai soldiers on the thai-cambodian border were entered into a randomized malaria chemoprophylactic trial. proguanil (200 mg/day) combined with sulfamethoxazole (1000 or 1500 mg/day) were compared to a standard combination of weekly pyrimethamine/dapsone (maloprim). men receiving proguanil/sulfamethoxazole had a significantly lower malaria attack rate than those taking pyrimethamine/dapsone. this was true of both the first five-week phase in which 1000 mg of sulfamethoxazole was used (0.11 v ... | 1991 | 1948264 |
| tissue schizontocidal effect of trifluoroacetyl primaquine in plasmodium yoelii infected mice and plasmodium cynomolgi infected monkeys. | trifluoroacetyl primaquine oxalate (m8506) was compared with primaquine phosphate for tissue schizontocidal action in rodent and simian malaria. in plasmodium yoelii sporozoites infected mice, the causal prophylactic effects of m8506 at 5, 10 and 20 mg(base)/kg were 56.7%, 87.2% and 100%, respectively, comparable to those of primaquine (54.4%, 90.8% and 100%). in p. cynomolgi sporozoites infected rhesus monkeys 4 dosage regimens of the two agents were compared for radical curative effect. on the ... | 1991 | 1948265 |
| safety and immunogenicity of a plasmodium falciparum sporozoite vaccine: boosting of antibody response in a population with prior natural exposure to malaria. | recombinant sporozoite vaccine or placebo were administered once to 25 volunteers from an area endemic for malaria. antibody to r32tet32 rose in 9 of 15 receiving vaccine and remained elevated in 6 for 6 months. mean absorbance increase was 0.43 +/- 0.40 with vaccine, 0.01 +/- 0.23 with placebo, and 0.72 +/- 0.19 in responders. six non-responders had significantly lower pre-immunization levels (0.07 +/- 0.05) than responders (0.39 +/- 0.25). there was an association between an increase in immuno ... | 1991 | 1949134 |
| comparison of intramuscular sulfadoxine-pyrimethamine and intramuscular quinine for the treatment of falciparum malaria in children. | the efficacy of intramuscular (i.m.) sulfadoxine-pyrimethamine (sulfadoxine 25 mg/kg plus pyrimethamine 1.25 mg/kg in a single dose; n = 48) was compared with that of i.m. quinine (10 mg/kg 8-hourly for at least 3 d followed by oral quinine to complete 7 d; n = 54) in children with severe malaria without life-threatening complications in maputo central hospital, mozambique, in 1989. mean parasite clearance time and mean fever clearance time were 55.4 h and 48.1 h, respectively, in the sulfadozin ... | 1991 | 1949135 |
| sensitivity of plasmodium falciparum in the gambia to co-trimoxazole. | in the gambia co-trimoxazole is used widely to treat children with an acute respiratory infection (ari). because malaria may sometimes be mistaken for ari, some children with malaria are treated with co-trimoxazole. therefore, we investigated the sensitivity of gambian isolates of plasmodium falciparum to this drug. six days after the start of treatment with co-trimoxazole 3.3% of blood films of 65 asymptomatic subjects were positive, and 7.7% were positive after 21 d. one of 10 patients with ar ... | 1991 | 1949136 |
| an enzyme-linked immunosorbent assay using detergent-soluble plasmodium vivax antigen for seroepidemiological surveys. | an enzyme-linked immunosorbent assay (elisa) to detect antibodies to plasmodium vivax parasites in human sera was developed using p. vivax-infected erythrocytes from local malarious patients in southern mexico. infected cells were concentrated using a discontinuous percoll gradient and detergent-soluble antigens obtained using triton x100. the use of detergent and the addition of protease inhibitors to the antigen preparation ensured high sensitivity and reproducibility of the assay. no cross re ... | 1991 | 1949138 |
| [malaria vaccination: status of development and prospects]. | the development of an active immunization against malaria is a major goal of scientific research for the last 10 years. while basic information about immunologic relevant epitopes for vaccine development are already available it must be conceded that there is a far way to a clinically available vaccine which is effective, well tolerated and--cheap. this review deals with the present difficulties for vaccine development and their approach to reality. it is tempting to speculate that control and e ... | 1991 | 1949823 |
| surface expression of malarial antigens in salmonella typhimurium: induction of serum antibody response upon oral vaccination of mice. | the escherichia coli ompa protein can serve as a carrier for the expression of foreign antigens on the surface of gram-negative bacteria. employing ompa vectors, immunogenic moieties of the plasmodium falciparum blood stage antigens serp and hrpii have been expressed in the attenuated salmonella typhimurium sr-11 strain. upon induction, the malaria specific sequences of 189 (hrpii) and 451 (serp) amino acids, fused into the ompa protein, have been expressed. by indirect immunofluorescence studie ... | 1991 | 1950099 |
| detection of antigens in urine of patients with acute falciparum and vivax malaria infections. | using an antigen-capture, dot-blot assay, antigens were detected in the urine of 50 patients infected with plasmodium falciparum. antigens were also detected in 12/15 patients who had no detectable parasitemias 1-2 weeks after chemotherapy. by western blotting and immunoprecipitation, four predominant antigens were identified with the following molecular masses (mr) and isoelectric points (pi): antigen 1, 200 kda, pi 6.4-6.27; antigen 2, 180 kda, pi 5.2-4.8; antigen 3, 150 kda, pi 5.5; antigen 4 ... | 1991 | 1951853 |
| comparative susceptibility of anopheline mosquitoes in rondonia, brazil to infection by plasmodium vivax. | seven anopheline species from costa marques, rondonia, brazil were compared with anopheles darlingi for susceptibility to infection by plasmodium vivax. laboratory-reared f1 progeny of field-collected an. darlingi and the test anopheline species were fed at the same time on the same patients, all of whom had gametocytes in peripheral blood before treatment. mosquitoes were dissected on day 8 after infection for oocysts and on days 14-16 after infection for sporozoites. the mean numbers of p. viv ... | 1991 | 1951854 |
| infection of anopheles darlingi fed on patients infected with plasmodium vivax before and during treatment with chloroquine in costa marques, rondonia, brazil. | patients with asexual and sexual parasites of plasmodium vivax were treated orally with 600 mg of chloroquine diphosphate at hour zero, followed by 300 mg at 8, 24 and 48 hr. anopheles darlingi were fed before the first dose (-0.5 hr) and at 0.5, 1, 2, 4, 6, 8, 9, 10, 11, 12, 20, 24, 36, 48, 60, and 72 hr later. mosquitoes were examined for oocysts on day 8 and sporozoites on day 15 after infection. the frequency of infected mosquitoes and the mean number of oocysts were lower in mosquitoes that ... | 1991 | 1951855 |
| infectious reservoir of plasmodium vivax and plasmodium falciparum malaria in an endemic region of sri lanka. | the infectious reservoir of plasmodium vivax and p. falciparum in a malaria endemic region in sri lanka was defined in a population of 3,625 by directly feeding mosquitoes on a sample of infected individuals during a period of 17 months. the malaria case incidence in this population was concurrently monitored. p. vivax gametocyte densities were highest in the youngest age groups, and decreased steadily with increasing age. however, the infectivity per gametocyte appeared to be lower in the young ... | 1991 | 1951856 |
| halofantrine for the treatment of mefloquine chemoprophylaxis failures in plasmodium falciparum infections. | thai soldiers who became slide-positive for malaria while receiving mefloquine chemoprophylaxis were treated with halofantrine to study its efficacy against mefloquine-resistant falciparum malaria. thirty-two patients received three doses of 500 mg (1,500 mg total) of halofantrine at six-hr intervals, and were then observed for four weeks. parasite recrudescence following treatment (median 21 days) occurred in seven of 23 patients (30%) who had mefloquine serum concentrations indicative of regul ... | 1991 | 1951857 |
| prevalence of the dihydrofolate reductase asn-108 mutation as the basis for pyrimethamine-resistant falciparum malaria in the brazilian amazon. | pyrimethamine resistance in cultivated laboratory isolates of plasmodium falciparum is linked to the dihydrofolate reductase mutation asn-108, a mutation that acts by interrupting drug binding within the active site of the enzyme. to determine the prevalence of this mutation in endemic regions harboring pyrimethamine-resistant malaria, we used a mutation-specific polymerase chain reaction assay to survey p. falciparum strains from a wide section of the brazilian amazon. mutations were identified ... | 1991 | 1951858 |
| successful immunization of humans with irradiated malaria sporozoites: humoral and cellular responses of the protected individuals. | two groups of volunteers were vaccinated by repeated exposure to the bites of plasmodium falciparum-infected, x-irradiated mosquitoes in order to characterize the humoral and cellular immune responses of sporozoite-immunized, protected individuals. one of the two volunteers in the first immunization trial, when challenged by the bite of p. falciparum-infected mosquitoes, developed an infection only after a prolonged prepatent period. a second group of three volunteers who were exposed more frequ ... | 1991 | 1951863 |
| lymphoproliferative responses to synthetic peptides from merozoite ring-infected erythrocyte surface antigen and circumsporozoite protein: a longitudinal study during a falciparum malaria episode. | proliferative responses of peripheral blood lymphocytes to synthetic peptides representing major epitopes of two malaria antigens (the merozoite ring-infected erythrocyte surface antigen and the sporozoite circumsporozoite protein) were investigated in madagascar during a clinical plasmodium falciparum episode. thirty-seven patients greater than 10 years of age were enrolled at the beginning of the malaria transmission season and followed for four weeks. at enrollment, when the subjects presente ... | 1991 | 1951864 |
| characterization of naturally acquired antibody responses to a recombinant fragment from the n-terminus of plasmodium falciparum glycoprotein 195. | antibody responses to the glycoprotein precursor of the major merozoite surface antigens of plasmodium falciparum (gp195) were investigated in acutely infected thai adults. specific igg antibody was assayed by enzyme-linked immunosorbent assay using a recombinant fragment derived from the n-terminal region of gp195 as the capture antigen. two control groups were found to be without significant cross-reacting antibody. among occupationally exposed soldiers, 84 of 85 men developed positive antibod ... | 1991 | 1951865 |
| the number of sporozoites produced by individual malaria oocysts. | mature oocysts of plasmodium falciparum and p. vivax from western thailand were separated from the midguts of anopheles dirus by collagenase digestion, and the number of sporozoites contained in each was counted. for 26 p. vivax oocysts, the mean count was 3, 688 (range 1, 954-5, 577) and for 14 p. falciparum, the mean count was 3, 385 (range 1, 359-4, 554); a single p. cynomolgi oocyst contained 7, 521. counts were not significantly correlated with oocyst density, oocyst age, or identity of the ... | 1991 | 1951866 |
| cytoadherence of plasmodium falciparum-infected erythrocytes to human umbilical vein and human dermal microvascular endothelial cells under shear conditions. | to investigate the role of hemodynamics in the adherence of plasmodium falciparum-infected erythrocytes to cerebral endothelium in vivo, we investigated cytoadherence of parasitized erythrocytes to human umbilical vein endothelial cells (huvec) under shear conditions in vitro. at 1.0 dyne/cm2 shear stress, parasitized red blood cell (rbc) adherence to huvec ranged from 9.9 +/- 1.0 (+/- sem) to 75.2 +/- 4.8 rbc/mm2 (mean +/- sem: 35.1 +/- 2.8 rbc/mm2) and was 13-fold greater than uninfected eryth ... | 1991 | 1951867 |
| congenital malaria in a hyperendemic area. | the prevalence of plasmodium falciparum malaria was evaluated in all near-term pregnant women and their newborns at the macha hospital in the southern province of zambia during part of the rainy season, when malaria prevalence is at its peak. peripheral parasitemia was noted in 19 (29%) of 65 newborns and in 40 (63%) of 63 mothers. all but one of the infected neonates had an infected mother, and 17 of 40 infected mothers gave birth to infected newborns. the parasite densities measured were unifo ... | 1991 | 1951868 |
| stage-specific ultrastructural effects of desferrioxamine on plasmodium falciparum in vitro. | desferrioxamine (dfo) is an iron chelator that inhibits the in vitro and in vivo growth of rodent and human malarial parasites. previous studies with this chelator have suggested that it might interfere with the intraerythrocytic growth of plasmodium sp. by withholding iron from any of several essential iron-dependent parasite enzymes, including those involved in co2 fixation, mitochondrial electron transport, pyrimidine synthesis, and the reduction of ribonucleotides for dna synthesis. we studi ... | 1991 | 1951869 |
| transdermal artelinic acid: an effective treatment for plasmodium berghei-infected mice. | artelinic acid, a derivative of the naturally occurring antimalarial artemisinin, has been incorporated into a gel suitable for transdermal administration. the formulation was tested for efficacy in plasmodium berghei-infected mice for both curative and prophylactic properties by application to their partially denuded backs, beginning on days 3 and 0, respectively, after injection of parasitized erythrocytes. in the curative experiments, rapid elimination of the parasitemia and 60-day survival o ... | 1991 | 1951870 |
| neither heparin nor acetylsalicylic acid influence the clinical course in human plasmodium falciparum malaria: a prospective randomized study. | procoagulant alterations and thrombocytopenia in falciparum malaria correlate with parasitemia, serum levels of tumor necrosis factor alpha (tnf alpha), and clinical severity. thus, heparin or acetylsalicylic acid (asa), which are used frequently to prevent thrombosis and (in the case of asa) to control fever, could be potentially beneficial. we randomized 97 patients with falciparum malaria into three groups: 33 patients received low-dose heparin subcutaneously, 31 received asa intravenously, a ... | 1991 | 1951871 |
| genetic control of the immune response to a synthetic vaccine against plasmodium falciparum. | two independent vaccination trials using a hybrid synthetic polypeptide containing epitopes from four proteins of plasmodium falciparum were performed. in the first trial 63 and in the second 122 volunteers were vaccinated, using different immunization schedules. the analysis of the humoral response to the vaccine, measured by igg antibody titres to the polypeptide showed a bimodal distribution in both cases suggesting genetic control of the immune response to this protein. there was a small gro ... | 1991 | 1956698 |
| [antimalarial activity of deoxoqinghaosu]. | compound 3 (deoxoqinghaosu) and compound 4 (deoxocarbaqinghaosu) were synthesized from arteannuic acid (2). primary exploration of their antimalarial effect against k173 strain of plasmodium berghei shows that compound 3 is somewhat more effective than the natural compound--qinghaosu. however, the carba-analogue compound 4 is almost ineffective. the enhanced activity of compound 3 is supposedly ascribed to its higher lipophilicity and, hence, higher affinity for plasmodial membrane. further stud ... | 1991 | 1957665 |
| [geographic approach to the epidemiology of chloroquine-resistance of plasmodium falciparum in tropical africa]. | plasmodium falciparum chloroquine-resistance occurred initially in 1978 in east africa. its step by step propagation towards west africa is due to several factors which coincide with a high increase of population migration and urbanization since the seventies. several maps show the dynamics of chloroquine-resistance in africa during that era. | 1991 | 1958104 |
| [current aspects of malarial chemoresistance of subjects autochthonous in the occge countries (west africa)]. | within the context of the monitoring of malaria drug resistance in the countries of the occge, a workshop has been organized in order to sum up the surveys carried out by the national teams. for active or passive monitoring mainly the in vivo tests have been used. the native population, mainly school children, was studied. chloroquine resistance was detected in 1987 in benin, and in the same year in togo and côte d'ivoire. during 1988 it appeared in senegal and burkina faso, in 1989 in niger and ... | 1991 | 1958105 |
| [preliminary studies on the diagnosis of plasmodium falciparum malaria by monoclonal antibody sandwich dot-immunogold silver staining assay]. | in this report, the blood samples from 30 falciparum malaria patients with parasitemia 0.015-0.58% and the blood samples from 30 healthy persons were examined by monoclonal antibody (mcab) sandwich dot-immunogold silver staining assay (dot-igssa). when the mcab 11g5, 13a2 and 13a1 were used for sandwich dot-igssa with mcab 14d9 labeled with colloidal gold respectively, the 0.0001% of parasitemia could be detected and the mcab 11g5, 13a1 and 14d9 labeled with colloidal gold could also be used to ... | 1991 | 1959167 |
| [effect of poly i:c on the sporozoite invasion and the development of exoerythrocytic forms of plasmodium yoelii yoelii in rats]. | when wistar rats were given intravenously with poly i:c 5 mg/kg 18 h before sporozoite inoculation, the density of exoerythrocytic forms (eef) in the rat liver 42 h after inoculation was markedly decreased, the sporozoite viability being only 5-12% of that of the controls. however, the size and maturation rate of eef were all normal. when poly i:c was given 2 h after sporozoite inoculation, the sporozoite viability and the size and the maturation rate of eef were similar to those of the controls ... | 1991 | 1959171 |
| [ultrastructural observation on the oocyst development and sporozoite formation of plasmodium vivax]. | the oocyst development of plasmodium vivax was heralded by the appearance of cytoplasmic vacuoles and membraneous clefts. these clefts broke up oocyst cytoplasm into many sporoblasts. the onset of transformation from oocyst to sporozoite was heralded by forming pellicular complex, at some point of pelliculum of sporoblast dense inner membrane and subpellicular microtubules formed beneath the plasmalemma. the pellicular complex bulged out to form sporozoite buds appearing as small domes. followin ... | 1991 | 1959175 |
| [malaria]. | | 1991 | 1959490 |
| plasmodium falciparum: modulation of surface antigenic expression of infected erythrocytes as revealed by cell fluorescence elisa. | the surface reactivity of heterologous immune sera with erythrocytes infected with plasmodium falciparum has been difficult to assess in quantitative terms because of the restricted accessibility of surface epitopes and the lack of sensitive methodologies. in a previous study we showed that cryptic antigens can become exposed on the surface of intact trophozoites if the sterol content of the membranes is increased by means conservative of cell integrity (d. baruch and z. i. cabantchik, molecular ... | 1991 | 1959571 |
| plasmodium yoelii: oral delivery of 5-fluoroorotate to treat malaria in mice. | | 1991 | 1959576 |
| malarial proteins that interact with the erythrocyte membrane and cytoskeleton. | several distinct classes of plasmodium proteins have been proposed to interact with the submembrane skeleton of the erythrocyte based upon differential solubility and subcellular localization studies. that the parasite affects the erythrocyte membrane by interacting with the submembrane skeleton is an attractive hypothesis since the membrane skeleton likely regulates many aspects of membrane topography and function. the precise interactions between host and parasite proteins at the molecular lev ... | 1991 | 1959577 |
| a plasmodium falciparum exo-antigen alters erythrocyte membrane deformability. | here we describe a reduced membrane deformability of human erythrocytes when aspirated into 0.6 microns diameter in polycarbonate sieves, after exposure of uninfected cells to spent parasite-culture supernatant. this, taken in concert with a previous observation that intra-erythrocytic development of the parasite p. falciparum decreases host localised membrane deformability, may indicate a biological role for such parasite-induced changes in the rheological properties of the erythrocyte. | 1991 | 1959636 |
| ineffectiveness of amodiaquine against plasmodium falciparum malaria in symptomatic young children living in an endemic malarious area of papua new guinea. | the standard in vivo 7-day test of drug resistance was conducted on 83 children with symptomatic p. falciparum infection, using a full 3-day course of amodiaquine. all children were living in an endemic malarious area of the east sepik province of papua new guinea. analysis of blood amodiaquine levels by an elisa method showed increased blood amodiaquine concentration with progressive days of treatment. by day 7 of the study period parasites had cleared in 68 (82 per cent) of the children while ... | 1991 | 1960777 |
| [malaria prevention in children]. | | 1991 | 1961220 |
| [right cardiac compromise and acute respiratory insufficiency (ira) caused by pulmonary edema in plasmodium falciparum malaria: description of a case]. | | 1991 | 1961551 |
| progess toward understanding the pathogenesis of sequestration in falciparum malaria. | | 1990 | 1965787 |
| adoptive transfer of cd8+ t cells from immune animals does not transfer immunity to blood stage plasmodium yoelii malaria. | the malaria parasite, plasmodium yoelii 17x, causes a self-limited, nonlethal infection characterized, in the blood stage, by preferential invasion of reticulocytes. previous studies have suggested that immunity to the blood stage infection may be related to enhanced levels of class i mhc ag on the parasitized reticulocyte surface and can be adoptively transferred to immunodeficient mice by immune cd8+ t cells in the absence of cd4+ t cells. to further examine the mechanisms of cd8+ t cell invol ... | 1990 | 1967271 |
| epidemic alert: malaria infections in travellers from west africa. | | 1990 | 1967411 |
| mefloquine failure in child contracting falciparum malaria in west africa. | | 1990 | 1967412 |
| proguanil, chloroquine, and mouth ulcers. | | 1990 | 1967450 |
| desipramine reversal of chloroquine resistance in wild isolates of plasmodium falciparum. | | 1990 | 1967451 |
| evaluation of an elisa kit for epidemiological detection of antibodies to plasmodium falciparum sporozoites in human sera and bloodspot eluates. | antibodies to plasmodium falciparum sporozoites represent a serological transmission indicator, which can be applied in epidemiological studies to estimate the intensity of malaria transmission. an elisa method has been developed as an industrial kit to detect these antibodies, using a chemically synthesized (nanp)40 peptide as antigen. the results obtained with this kit are compared in the present paper with those obtained by an elisa test already applied in epidemiological studies. in testing ... | 1990 | 1967504 |
| an ultrastructural study of the exoerythrocytic schizonts of plasmodium cynomolgi and p. knowlesi in macaca mulatta. | exoerythrocytic schizonts of plasmodium cynomolgi and p. knowlesi were examined by electron microscopy in biopsy samples of primate livers. with maturity the parasitophorous vacuole membrane becomes highly sculptured by the addition of a discontinuous dense thickening, the distribution of which can be a distinguishing character between these two species. the parasitophorous vacuole membrane follows the contours of the parasite faithfully with a minimal surrounding vacuole. the marked destruction ... | 1990 | 1967505 |
| physical relationship between a gene and its origin of replication in physarum polycephalum. | taking advantage of the natural synchrony of the s-phase within the plasmodium of physarum polycephalum, we extracted highly synchronous dna samples at precise time points in early s-phase. we then separated, by electrophoresis under denaturating conditions, the newly synthesized dna strands of the nascent chromosomal replicons from the parental dna template. using the cdna clone of the early-replicating lav1-2 gene as a probe, we could establish by filter hybridization that the elongation rate ... | 1990 | 1967581 |
| comparative susceptibility of culex tarsalis, anopheles franciscanus, and culiseta inornata (diptera: culicidae) to plasmodium relictum (haemosporidia: plasmodiiae). | repeated laboratory attempts failed to infect culiseta inornata (williston) and anopheles franciscanus mccracken with plasmodium relictum as efficiently as culex tarsalis coquillett controls. of 210 an. franciscanus that imbibed a replete meal from a parasitemic canary, two were found with oocysts and none with sporozoites. of 112 cs. inornata similarly fed, seven contained oocysts and one contained sporozoites. in contrast, of 94 cx. tarsalis tested, 80 (85%) were found with oocysts, thus confi ... | 1990 | 1967655 |
| exchange transfusion in falciparum malaria. | | 1990 | 1967774 |
| transmission of plasmodium vivax malaria in san diego county, california, 1986. | between 18 june and 20 september 1986, 28 cases of plasmodium vivax malaria were documented in carlsbad, california, a coastal town north of san diego. malaria occurred in 1 local resident who had no risk factors, a second local resident who had traveled to a malarious area 9 months earlier, and 26 mexican migrant workers (mws). among the 28 cases, 27 lived in a square mile marshy area where anopheles hermsi, a newly described american species of the anopheles maculipennis group, was known to be ... | 1990 | 1967916 |
| t lymphocyte interferon-gamma production induced by plasmodium falciparum antigen is high in recently infected non-immune and low in immune subjects. | interferon (ifn) alpha and gamma were measured by radio-immunoassays in supernatants from cultures of peripheral blood mononuclear cells (pbmc) or purified t cell subsets incubated with either plasmodium falciparum schizont-enriched malaria antigen (mag), uninfected red blood cells (rbc) or pokeweed mitogen (pwm). cell donors were 24 clinically immune, healthy african adult native residents of a p. falciparum-endemic region, haut-ogooué, gabon, and seven non-immune, european temporary residents ... | 1990 | 1967995 |
| reduced in vitro susceptibility to halofantrine of plasmodium falciparum in west africa. | | 1990 | 1968157 |
| desipramine or cyproheptadine for reversing chloroquine resistance? | | 1990 | 1968158 |
| diagnosis of malaria. | | 1990 | 1968191 |
| runway malaria. | | 1990 | 1968192 |
| controlled trial of exchange transfusion in falciparum malaria. | | 1990 | 1968572 |
| cd4+ t cells play a major role for igm and igg anti-dna production in mice infected with plasmodium yoelii. | the infection by a non-lethal strain of plasmodium yoelii induces the formation of autoantibodies such as anti-dna and anti-sm antibodies in mice. the extent of the relative increase in serum levels of igm and igg anti-dna and anti-sm antibodies and their kinetics were found to be similar to those of anti-hapten antibodies and of total igm and igg levels. this strongly suggested that anti-dna and anti-sm autoantibody responses observed in malaria-infected mice are a result of polyclonal activati ... | 1990 | 1968798 |
| alterations caused by the intraerythrocytic malaria parasite in the permeability of its host cell membrane. | | 1990 | 1968813 |
| protection against malaria induced by irradiated sporozoites. | | 1990 | 1969073 |
| delphi survey of malaria mortality and drug resistance in africa. | | 1990 | 1969074 |
| exchange transfusion for malaria. | | 1990 | 1969531 |
| activation of phagocyte oxidative metabolism by opsonized plasmodium falciparum merozoites. | a luminol-dependent chemiluminescence (cl) method was used to measure the oxidative burst of phagocytes triggered by antimalarial antibodies and plasmodium falciparum merozoites. a specific antibody-dependent increase in chemiluminescence response was obtained using both polymorphonuclear leukocytes and monocytes as effector cells. using various sera from malaria infected subjects it was observed that antibodies involved in the increased chemiluminescence responses were encountered at higher lev ... | 1990 | 1969702 |
| mefloquine prophylaxis. | | 1990 | 1970042 |
| exchange transfusion in falciparum malaria. | | 1990 | 1970083 |
| emetine-resistant mutants of entamoeba histolytica overexpress mrnas for multidrug resistance. | we report here the identification of multiple 344-bp segments of amoeba dna similar to the human multidrug resistance (mdr) gene using primers to conserved regions of the p-glycoprotein and the polymerase chain reaction (pcr). the amino acid sequences of amoeba mdr-like pcr products were 46-97% identical to each other, 46-51% identical to human mdr1 sequences, and 30-35% identical with plasmodium falciparum mdr-like sequences. on northern blots, the mdr-like pcr products identified amoeba mrnas ... | 1990 | 1970121 |
| chloroquine resistance not linked to mdr-like genes in a plasmodium falciparum cross. | chloroquine is thought to act against falciparum malaria by accumulating in the acid vesicles of the parasite and interfering with their function. parasites resistant to chloroquine expel the drug rapidly in an unaltered form, thereby reducing levels of accumulation in the vesicles. the discovery that verapamil partially reverses chloroquine resistance in vitro led to the proposal that efflux may involve an atp-driven p-glycoprotein pump similar to that in mammalian multidrug-resistant (mdr) tum ... | 1990 | 1970614 |
| modern vaccines. parasitic diseases. | | 1990 | 1971332 |
| interleukin-2 reverses t cell unresponsiveness to plasmodium falciparum-antigen in malaria immune subjects. | peripheral blood mononuclear cells (pbmc) from a large proportion of 34 healthy adult native residents in a malaria endemic area showed null or marginal proliferative response (low-responders) to schizont-enriched plasmodium falciparum malaria antigen (m.ag) but good response to pokeweed mitogen. in contrast, substantial proliferative response to m.ag was observed in 8/8 adult temporary residents with a history of one to three acute malaria episodes. purified cd4+ t cells preferentially responde ... | 1990 | 1971525 |
| reversal of chloroquine-resistant falciparum malaria. | | 1990 | 1971885 |
| chromosome 9 from independent clones and isolates of plasmodium falciparum undergoes subtelomeric deletions with similar breakpoints in vitro. | we show that chromosome 9 in all isolates and clones of plasmodium falciparum examined so far exists as one of two distinctly different forms, a large form about 1.9 megabases long or a smaller form about 25% shorter. physical maps of chromosome 9 from independent clones with large and small forms of chromosome 9, and from an isolate with the large form and 3 derived clones with the small form reveal the underlying structural basis of this size polymorphism. the small form differs from the large ... | 1990 | 1971913 |
| specific killing of cytotoxic t cells and antigen-presenting cells by cd4+ cytotoxic t cell clones. a novel potentially immunoregulatory t-t cell interaction in man. | mycobacterial antigens not only stimulate th cells that produce macrophage-activating factors, but also cd4+ and cd8+ ctl that lyse human macrophages. the mycobacterial recombinant 65-kd hsp was previously found to be an important target antigen for polyclonal cd4+ ctl. because of the major role of 65-kd hsp in the immune response to mycobacterial as well as autoantigens, we have studied ctl activity to this protein at the clonal level. hla-dr or hla-dq restricted, cd4+cd8- t cell clones that re ... | 1990 | 1972178 |
| runway malaria. | | 1990 | 1972476 |