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differential effect of immunoglobulin on the in vitro growth of several isolates of plasmodium falciparum.immunoglobulin isolated from the sera of individuals living in a malarious area of papua new guinea was tested for an effect on the growth in vitro of four isolates of plasmodium falciparum, three from papua new guinea and one from thailand. the papua new guinea isolates were inhibited to the same degree by individual immunoglobulin preparations, and inhibition varied from 0 to 98% (assessed by a radioisotopic readout). immunoglobulin preparations which inhibited the papua new guinea isolates ca ...19836188695
quinine and quinidine: a comparison of ekg effects during the treatment of malaria.we recorded electrocardiograms from 31 patients receiving quinine and 14 patients receiving quinidine for the treatment of plasmodium falciparum malaria. despite plasma quinine concentrations of up to 20 mg/l, there was no evidence of cardiotoxicity. qt prolongation was considerably greater in the quinidine-treated patients. the mean ratio of change in corrected qt interval to change in plasma concentration (delta qtc%/delta cq) was 3.2% . mg-1 . l-1 for quinidine, compared to 0.74% . mg-1 . l-1 ...19836188885
circumsporozoite proteins of malaria parasites contain a single immunodominant region with two or more identical epitopes.we have used panels of monoclonal antibodies to circumsporozoite (cs) proteins of plasmodium falciparium, p. vivax, and p. knowlesi to determine the number of topographically independent epitopes of these antigens. the results of competition binding assays indicated that single regions of the cs molecules were recognized by the homologous monoclonal antibodies. competition binding assays were also used to study the specificity of antibodies contained in the sera of humans and monkeys that had de ...19836189951
immunological cross-reactivity of the histidine-rich protein of plasmodium lophurae and the knob protein of plasmodium falciparum.rabbits were immunized with the histidine-rich protein (hrp) of the avian malaria parasite, plasmodium lophurae. the anti-hrp immunoprecipitated the knob protein (kp) from extracts of the human parasite, plasmodium falciparum. the anti-hrp did not react with any antigens of a laboratory-derived strain of p. falciparum (k-) that does not form knobs. antisera raised against a membrane-enriched fraction of p. falciparum-infected erythrocytes as well as sera from humans exposed to p. falciparum infe ...19836189987
platelet secretory activities in acute malaria (plasmodium falciparum) infection.during acute plasmodium falciparum infection in man, plasma concentrations of platelet-specific proteins, beta-thromboglobulin (beta tg) and platelet factor 4 (pf4) were significantly elevated. for beta tg, the mean concentration was 136.24 +/- 71.58 ng/ml in patients, and 50.53 +/- 25.42 ng/ml in control subjects (t = 5.3794; p = 0.0001), while for pf4 mean values were, respectively, 75.35 +/- 23.09 and 18.64 +/- 13.42 ng/ml (t = -6.0897; p less than 0.0001). platelet ldh loss in vitro in respo ...19836192658
regulation of the immune response in plasmodium falciparum malaria. ii. antigen specific proliferative responses in vitro.the antigen-induced dna synthesis in vitro in lymphocytes from patients with acute plasmodium falciparum malaria was investigated. the patients and healthy controls from sweden or colombia were the same as those studied in the accompanying paper (troye-blomberg et al., 1983). the malarial antigens used were sonicated membrane preparations or purified and concentrated supernatants from in vitro cultures of p. falciparum; similar preparations derived from normal human erythrocytes served as contro ...19836192953
role of internal domains of glycophorin in plasmodium falciparum invasion of human erythrocytes.human erythrocyte glycophorin, a putative receptor to plasmodium falciparum malaria parasites, was studied in terms of its structural domains involved in mediating invasion. these domains were isolated from purified glycophorin a and from supernatants and membranes obtained from protease-treated erythrocytes. they were tested for invasion blocking capacity by using an in vitro assay system. the role of carbohydrate-rich domains was assessed with the following compounds: (i) sialoglycopeptides re ...19836194114
characterization of an s antigen synthesized by several isolates of plasmodium falciparum.the s antigen of a papua new guinean isolate of plasmodium falciparum was identified by immunoblotting as the dominant antigen in culture supernatants. an antigen identical in molecular weight (mr 220,000), isoelectric point (pi 4.2), and immunoreactivity with sera from individuals exposed to malaria was expressed by four papua new guinean isolates and one isolate of unknown origin. the mr 220,000 antigen was not detected in culture supernatants derived from two isolates from thailand and one fr ...19836195663
serum alpha-1 antichymotrypsin is a possible growth inhibitor of plasmodium falciparum.serum protease inhibitors were determined in paired sera from 7 patients with cerebral malaria and 2 patients with acute malaria showing high and low growth inhibition activity in the initial and follow-up sera respectively. alpha-1 antichymotrypsin and alpha-1 antitrypsin but not alpha-2 macroglobulin showed direct correlation with the growth inhibition activity. when alpha-1 antitrypsin was deliberately added to the malarial culture no growth inhibition occurred indicating that the alpha-1 ant ...19836197759
reactions of toxoplasma antibodies against three malarial antigens. 19836198408
stage-dependent effects of chloroquine on plasmodium falciparum in vitro.the erythrocytic developmental cycle of plasmodium falciparum can be conveniently divided into the ring, trophozoite, and schizont stages based on morphology and metabolism. using highly synchronous cultures of p. falciparum, considerable variation was demonstrated among these stages in sensitivity to chloroquine. the effects of timed, sequential exposure to several clinically relevant concentrations of chloroquine were monitored by three techniques: morphological analysis, changes in the rate o ...19836198514
human serum proteins indicative for the nutritional status and serum proteinase inhibitors in uncomplicated falciparum malaria.the serum proteins supposed to be indicative of the nutritional status, albumin, prealbumin and transferrin, as well as the serum proteinase inhibitors alpha 1-protease inhibitor (alpha 1-antichymotrypsin (ach) and alpha 2-macroglobulin (alpha 2m) were measured in 14 thai males suffering from uncomplicated falciparum malaria on the day of admission and after treatment with mefloquin on the 2nd, 28th and 63rd day. the same serum proteins had been determined from 31 healthy thai males. upon admiss ...19836198795
susceptibility to invasion by plasmodium falciparum of some human erythrocytes carrying rare blood group antigens.tn and cad erythrocytes which carry unusual carbohydrate moieties attached to glycophorin a and b, the main red cell membrane sialoglycoproteins, resist invasion by the malarial parasite plasmodium falciparum. tn red cells are defective in sialic acid and galactose whereas cad erythrocytes are characterized by a normal sialic acid content but the presence of an additional n-acetylgalactosamine residue attached to each sialotetrasaccharide chain o-glycosidically linked to glycophorin a and b. hom ...19836200133
fulminant plasmodium falciparum infection treated with exchange blood transfusion.a 48-year-old physician, who was not undergoing malaria chemoprophylaxis, contracted plasmodium falciparum while working in eastern thailand. in the hospital, he had a peak parasitemia of 72% rbcs infected, associated with cns dysfunction. as an adjunct to chemotherapy, a double-volume whole-blood exchange transfusion was performed on the first hospital day, dropping the parasitemia to less than 1% within 32 hours. the patient's clinical condition improved, with a prompt reversal of cns, hepatic ...19836336796
malaria and iron. 19836336947
plasmodium falciparum: assessment of in vitro growth by [3h]hypoxanthine incorporation.to evaluate rapidly plasmodium falciparum growth in vitro, [3h]hypoxanthine was added to parasite microcultures and radioisotope incorporation was measured. when culture parameters were carefully controlled, [3h]hypoxanthine incorporation was proportional to the number of parasitized erythrocytes present. factors affecting [3h]hypoxanthine incorporation included initial parasitemia, duration of culture, duration of radioisotope pulse, parasite stage, concentration of uninfected erythrocytes, the ...19836337059
plasmodium falciparum: one-step growth in a semi-defined medium and the stimulatory effect of human seric lipoproteins and liposomes.the ring stages of plasmodium falciparum within red blood cells cultured with complete medium stop growing when transferred to a basic medium containing rpmi plus fatty acid-free bovine serum albumin and dialyzable factors from human serum. growth and multiplication can be partially restored by the addition of lipoprotein fractions prepared from human serum. no specificity was observed with subclasses of lipoproteins. synthetic liposomes containing lecithin, oleic acid, and cholesterol mimic the ...19836337060
permselectivity changes in malaria (plasmodium falciparum) infected human red blood cell membranes.the development of the malaria parasite plasmodium falciparum in human red blood cells induces parasite-dependent perturbations in the permselectivity properties of the host cell membrane. the changes appear as parasites develop from ring to the trophozoite stage and persist during schizogony. in the present work we assessed the permeability changes of the infected cells to anionic substances by the use of radioactive and fluorescent probes. our data show that i) covalent binding probes, such as ...19836337170
glucose-6-phosphate dehydrogenase deficiency inhibits in vitro growth of plasmodium falciparum.glucose-6-phosphate dehydrogenase (g6pd; ec 1.1.1.49)-deficient red blood cells from male hemizygotes and female heterozygotes from the island of sardinia were studied for their ability to support growth in vitro of the malaria-causing organism plasmodium falciparum. parasite growth was approximately one-third of normal in both hemi- and heterozygotes for g6pd deficiency. in sardinians with the beta 0-thalassemia trait, parasite growth was normal except when g6pd deficiency occurred together wit ...19836337374
quinine loading dose in cerebral malaria.in cerebral malaria, the use of currently recommended doses of intravenous quinine may result in subtherapeutic plasma concentrations during the critical first 24 hours of treatment. a loading dose of quinine (20 mg/kg quinine dihydrochloride, equivalent to 16.7 mg/kg base, infused over 4 hours) proved a rapid and safe method of achieving plasma concentrations above the high minimum inhibitory concentrations for plasmodium falciparum prevalent in eastern thailand.19836337514
preliminary field trial of a radioimmunoassay for the diagnosis of malaria.a radioimmunoassay (ria) has been developed for the detection of plasmodium falciparum in infected blood. the assay is based on the ability of solubilized, infected red blood cells (rbc) (p. falciparum "antigen") to combine with anti-p. falciparum antibodies and thus prevent the subsequent interaction of the latter with "antigen"-coated microtiter plates. a preliminary trial was carried out in thailand to determine the usefulness of the ria for the immunodiagnosis of malaria. blood samples from ...19836337515
a microassay for detecting merozoite inhibition suitable for routine laboratory use.a micro semiautomative assay of merozoite inhibition antibody has been developed, based on incorporation of radiolabeled isoleucine into parasite protein. the assay has been validated using 44 sera from healthy blood donors in madang. inhibition of uptake of label occurred in 43.2% of tests, while an enhancement of uptake was demonstrated in 4.7%. this assay has 'potential' for both seroepidemiological studies, and for providing a mechanism of biotyping wild isolates.19836337519
inhibitory effect of a fava bean component on the in vitro development of plasmodium falciparum in normal and glucose-6-phosphate dehydrogenase deficient erythrocytes.we examined the hypothesis that g-6-pd deficiency associated with fava bean ingestion confers resistance to malaria by studying the in vitro interactions between malaria parasites (plasmodium falciparum), human erythrocytes with varying degrees of g-6-pd deficiency, and isouramil (iu), a fava bean extract that is known to cause oxidant stress and hemolysis of g-6-pd-deficient erythrocytes. untreated g-6-pd-deficient and normal erythrocytes supported the in vitro growth of p. falciparum equally w ...19836337653
comparative clinical and experimental study on the pathogenesis of cerebral malaria. 19836337773
[falciparum malaria in east african tourists in spite of fansidar prevention. a contribution on increased chloroquine and pyrimethamine-sulfadoxine resistance in areas of east africa].a decreased chloroquine (resochin) sensitivity of strains of plasmodium falciparum in certain areas of east africa has given rise to an inappropriate change of chemoprophylaxis to pyrimethamine-sulfadoxine (fansidar). falciparum malaria occurred in five tourists during or after fansidar prophylaxis. a therapeutic chloroquine-r2-resistance was observed in one seriously ill patient. in some patients the course of disease was prolonged to such an extent that the diagnosis could be established only ...19836337809
[drug-resistant malaria in east africa].two tourists from kenya with falciparum malaria had an r1-resistance against chloroquine (who-extended field test, no in-vitro test). in addition, one of them was resistant against pyrimethamine-sulfadoxine (fansidar), however sensitive against quinine and mefloquine. in a third tourist, from tanzania, a diagnosis of chloroquine-resistance had been made too early and drug medication had been changed. these observations document the necessity of early species diagnosis. it is recommended to consi ...19836337810
orotidylate-metabolizing enzymes of the human malarial parasite, plasmodium falciparum, differ from host cell enzymes.orotate phosphoribosyltransferase and orotidylate decarboxylase from mammalian sources reside on a bifunctional protein. in such a system, orotidylate, the product of orotate phosphoribosyltransferase is preferentially channeled to orotidylate decarboxylase and does not equilibrate with the assay medium. in contrast, we found that orotidylate was released into the medium during the conversion of orotate to uridylate by cell-free extract of plasmodium falciparum. furthermore, orotate phosphoribos ...19836338005
structural similarities among the protective antigens of sporozoites from different species of malaria parasites. 19836338017
resistance of melanesian elliptocytes (ovalocytes) to invasion by plasmodium knowlesi and plasmodium falciparum malaria parasites in vitro.erythrocytes from humans with melanesian elliptocytosis are resistant to invasion by plasmodium falciparum in vitro and epidemiological evidence suggests they may be resistant to p. vivax and p. malariae. we have examined the ability of p. knowlesi merozoites to invade melanesian elliptocytes in vitro as a definitive means of examining these cells for resistance to invasion by malarial species with different receptor requirements. the melanesian elliptocytes were highly resistant to invasion by ...19836338046
storage requirements for erythrocytes used to culture plasmodium falciparum.erythrocytes stored for up to 84 days in citrate-phosphate-dextrose (cpd), cpd-adenine, saline-glucose, saline-glucose-adenine, or as packed cells were tested after varying lengths of time for suitability to support cultures of plasmodium falciparum using the petri dish-candle jar technique. all storage protocols were adequate for 21 to 28 days with those media containing adenine being generally better and packed cells poorer than cpd. erythrocyte atp contents generally correlated well with the ...19836338189
studies on the indochina i/cdc strain of plasmodium falciparum in colombian and bolivian aotus monkeys and different anophelines.the indochina i/cdc strain of plasmodium falciparum was isolated from a physician returning to the united states after working in the refugee camps along the thailand-kampuchean border. the strain was established in splenectomized aotus monkeys from colombia after being grown in vitro for 50 days. during the first three passages in colombian monkeys, the parasites were not infective to bolivian aotus monkeys. after six intervening passages in saimiri sciureus monkeys, the parasites produced high ...19836338191
phagocytosis of plasmodium falciparum-parasitized erythrocytes by human polymorphonuclear leukocytes.polymorphonuclear leukocytes (pmn) from normal blood donors phagocytosed p. falciparum-infected red blood cells (irbc) to a greater extent than normal rbc under in vitro culture condition. the phagocytic activity of pmn was greatly increased by the addition of sera from individuals living in areas endemic for malaria (immune sera) but not by sera from individuals recovering from a first acute p. falciparum infection. the enhancement of the phagocytic activity was associated with the purified igg ...19836338199
lack of cross-resistance to 4-aminoquinolines in chloroquine-resistant plasmodium falciparum in vitro.the potencies of 10 quinoline-containing antimalarials, including chloroquine, amodiaquine, cm-2,999-2k, quinine, mefloquine, sn-6911, sn-11875, sn-12108, sn-12308, and sn-12309, were determined in vitro against five strains of plasmodium falciparum characterized in vivo and in vitro by various degrees of sensitivity to chloroquine. these strains included the chloroquine-sensitive strains honduras and fcc1, and r1-resistant line fcr3tc, and the r3-resistant strains fcr1 and viet nam smith (vns). ...19836338201
chloroquine-resistant falciparum malaria. 19836338393
lectin-like polypeptides of p. falciparum bind to red cell sialoglycoproteins.attempts to control human malaria by immunological means could be compromised by antigenic variability within and between different strains of malarial parasites1. a useful alternative approach might be to block parasite antigens which are important in the mechanisms of invasion of red cells. as the major human parasite plasmodium falciparum is highly specific for human red cells, isolation of the proteins involved in the recognition of red cells by this parasite might be of particular value. re ...19836338394
uptake of l-tryptophan by erythrocytes infected with malaria parasites (plasmodium falciparum).the initial rates of uptake of l-tryptophan into normal human red blood cells and into cells infected by the malarial parasite plasmodium falciparum in vitro, were investigated. we find that transport in non-infected cells, which is mediated by the specific saturable t system and the apparently non-saturable l system (rosenberg, young and ellory (1980) biochim. biophys. acta 598, 375-384) is considerably enhanced by blood preservation and culture conditions. this increase is mostly due to an inc ...19836338923
an assay of malaria parasite invasion into human erythrocytes. the effects of chemical and enzymatic modification of erythrocyte membrane components.invasion of erythrocytes by malaria parasites is known to be blocked by proteolytic digestion of merozoite receptors allegedly present in red cell membranes. this information was used in the present work to develop a simple and convenient assay for parasite invasion into red blood cells and for evaluating the role played by red cell membrane components in this process. synchronized in vitro cultures of plasmodium falciparum containing only ring stages were subjected to either trypsin or pronase ...19836338931
deficient spontaneous cell-mediated cytotoxicity and lectin-induced cellular cytotoxicity by peripheral blood mononuclear cells from thai adults naturally infected with malaria.to assess general cytotoxic effector cell capabilities by peripheral blood mononuclear cells from patients with active malaria infections, we examined antibody-dependent cellular cytotoxicity, spontaneous cell-mediated cytotoxicity, and lectin-induced cellular cytotoxicity by using human and chicken erythrocyte, chang cell line, and k562 cell line targets. by using human erythrocyte and change cell line targets, we found that thai adults naturally infected with malaria had significantly impaired ...19836339549
drug-resistant malaria raises concern, controversy. 19836339767
malaria--resurgence, resistance, and research. (first of two parts). 19836339920
malaria--resurgence, resistance, and research (second of two parts). 19836339925
[the anti-arrhythmia drug quinidine as an alternative in the treatment of severe falciparum malaria].parenteral quinine is the most effective treatment for severe falciparum malaria. it is not easily available in switzerland and so dangerous delays treating patients may occur. the antiarrhythmic drug quinidine, usually stocked by hospitals, is an alternative drug for malaria treatment. we report the cases of two patients with severe malaria imported from kenya. they were treated first with intravenous quinidine sulfate over 3 days and for another 4 days with peroral quinidine sulfate. the thera ...19836340187
[a case of chloroquine-resistant tropical malaria from eastern africa (kenya)].a case of chloroquine-resistant falciparum malaria in a non-immune swiss tourist is described. the infection was acquired in kenya in spite of regular chloroquine prophylaxis with therapeutic serum levels. the isolated plasmodia showed marked in vitro resistance to chloroquine and sensitivity to mefloquine and pyrimethamine.19836340188
malaria eradication in venezuela: doctrine, practice, and achievements after twenty years. 19836340536
malaria at san lazaro hospital, manila, philippines, 1979-1981.results are presented from the 1,000 slide-confirmed malaria cases seen during the period august 1979-september 1981 at san lazaro hospital, in manila, philippines; 56% were caused by plasmodium falciparum, 38% by p. vivax, 6% were mixed infections, and 0.1% by p. malariae. the overall case fatality rate was 1%, all due to p. falciparum. cerebral involvement occurred in 7% and the case fatality rate was 20% compared to a case fatality rate of 0.2% among p. falciparum cases without cerebral invol ...19836340537
combined chloroquine/fansidar-resistant falciparum malaria appears in east africa.the first two cases from east africa of rii chloroquine- and fansidar-resistant falciparum malaria are described. the first case occurred in a non-immune swedish expatriate 2 weeks after arrival in tanzania, and the second in a semi-immune tanzanian soldier. fansidar has not yet been marketed in tanzania. the significance and etiology of the occurrence of combined chloroquine/fansidar resistance in east africa are discussed.19836340538
effects of antibiotics on plasmodium falciparum in vitro.evidence from in vivo experiments and clinical reports in humans has indicated that some antibiotics demonstrate antimalarial activity. twelve antibiotics have been tested against plasmodium falciparum in vitro, including cycloheximide, streptomycin, erythromycin, tetracycline, chloramphenicol, clindamycin, actinomycin d, rifampin, nalidixic acid, penicillin g, chlorhexidine, and isoniazid. inhibitory effects obtained at various drug concentrations in vitro were compared to drug levels reported ...19836340539
plasmodium falciparum: comparison of in vitro growth of knobby and knobless isolates.variants (k-) of three strains of plasmodium falciparum which do not produce the erythrocyte surface alterations that have been called knobs have been compared with their wildtype knobby (k+) parents. the k- variants achieve higher parasitemias, incorporate radiolabeled isoleucine more rapidly, and produce a higher percentage of multiply-infected cells than do their k+ parents. nevertheless, immune owl monkey sera cause approximately the same percentage inhibition of growth of both k+ and k- org ...19836340540
ineffective erythropoiesis in acute human p. falciparum malaria.an analysis of erythroblast cell kinetics utilizing quantitative 14c-autoradiography has been performed in five cases of acute plasmodium falciparum malaria prior to and, in four patients, 3 or 6 days after the onset of antimalarial therapy. associated with no or only moderate anemia were changes of erythroblast morphology, a considerable shift in the frequency of red and white blood cell precursors in the bone marrow, and a reduced rate of erythroblast proliferation. there was a marked loss of ...19836340761
[congenital plasmodium falciparum malaria. apropos of a case in paris].a 28 years old parturient woman, coming back from cameroon, was admitted with fever. blood smear for malaria revealed trophozoïtes of plasmodium falciparum. because of fetal troubles, the infant was born by a caesarean. physical examination of the new-born revealed an hepatomegaly. cord blood film showed trophozoïtes of plasmodium falciparum. with treatment with chloroquine, the child looked healthy in a few days. so, congenital malaria is not seldom in areas of high malaria endemicity, but we m ...19836340844
[use of purified antigens in the serodiagnosis and epidemiologic studies of human malaria. importance of the elisa technic for determining specific igg and igm].a purified antigen was isolated from the red blood cells of saimiri sciureus which was experimentally infected by plasmodium falciparum. an enzyme immunoassay (elisa) was carried out thanks to this antigen. the results obtained with the test were evaluated from two series of sera: one coming from an endemic area, the other taken out of it. the results were compared with those obtained with indirect fluorescent antibody test (ifat) which is considerated as reference test. there is a good correlat ...19836340845
plasmodium falciparum polypeptides released during in vitro cultivation.synchronous cultures of plasmodium falciparum were successively labelled with ((35)s)-methionine and both the supernatants and the pellets of infected red blood cells were collected. the release of tca-precipitable material in the culture supernatants was low during the development of ring forms and trophozoites, increased during schizogony, and was maximum at the time of schizont rupture and merozoite reinvasion. analysis of the supernatants by sds - page and autoradiography showed that both po ...19836340846
development of malaria vaccines: memorandum from a usaid/who meeting.the fifth meeting of the scientific working group on the immunology of malaria evaluated studies of the production and analysis of defined malarial antigens. rapid progress has been made in the study of protective antigens on the surface of sporozoites and it is likely that a family of analogous polypeptides occurs in several species of plasmodium. new assays have been developed for the detection of these antigens and for the detection of infected mosquitos. exoerythrocytic stages of several par ...19836340848
characterization of cold reactive lymphocytotoxic antibodies in malaria.characterization of cold reactive lymphocytotoxic antibodies present in sera from thai adults with malaria revealed that the antibodies are predominantly 19s (igm), directed against both autologous and allogeneic mononuclear cells, complement-dependent, present in titres ranging from 1:2 to 1:16, and exhibit greater lymphocytotoxic activity during the acute stage of malarial infection than during the convalescent stage. the lymphocytotoxic antibodies were primarily directed against b cell target ...19836340870
influence of the spleen on the expression of surface antigens on parasitized erythrocytes.two malaria parasites, plasmodium knowlesi and p. falciparum, when passaged in splenectomized hosts alter or fail to express parasite-dependent antigens on the surface membrane of erythrocytes infected with mature parasites. experiments with cloned populations of p.knowlesi show this change to be phenotypic and to be modulated by the spleen of the host. in addition, the induction of antigen variation in p. knowlesi malaria apparently requires two factors: specific antibody and the spleen. along ...19836340998
genetic variation in the host and adaptive phenomena in plasmodium falciparum infection.the in vitro culture of plasmodium falciparum, after synchronization, lends itself well to an analysis of the asexual schizogonic cycle. we have found in this system that dna synthesis and rna synthesis are associated mainly with the trophozoite stage, with the latter peaking slightly ahead of the former. distinctive patterns of protein synthesis are seen at serial times along the cycle, with a number of 'stage-specific' bands identifiable on sds gels. the fate of the infection can be influenced ...19836341000
glycophorins and red cell invasion by plasmodium falciparum.the major red cell sialoglycoproteins, the glycophorins, play a central role in the invasion of human red cells by plasmodium falciparum. en(a-) cells deficient in glycophorin a (alpha) and s-s-u- cells deficient in glycophorin b (delta) are relatively resistant to invasion, while trypsin treatment of s-s-u- cells, which removes most of the remaining sialoglycoprotein, renders these cells almost totally resistant to invasion. parasites inside these glycophorin-deficient cells develop normally. i ...19836341001
expression of inherited resistance to malaria in culture. 19836341002
mode of action of antimalarial drugs.chloroquine, quinine, quinacrine and related drugs are effective antimalarial agents only against parasites that degrade haemoglobin. this fact prompted an examination of the role of ferriprotoporphyrin ix (fp), a product of haemoglobin degradation, in the mode of action of chloroquine. fp was identified as a high affinity drug receptor of malaria parasites by showing that it has the appropriate affinity for chloroquine, with a dissociation constant on the order of 10(-8) m, and specificity for ...19836341003
the anaemia of plasmodium falciparum malaria.anemia is an important complication of p. falciparum malaria infection. this paper describes recent studies that have attempted to define some of the pathophysiological mechanisms involved in different forms of infection and at different stages of the illness. after an acute infection there is a steady fall in the haemoglobin level with an inappropriate reticulocyte response. current evidence indicates that this form of anaemia may result from a combination of acute sequestration of iron in the ...19836341004
a lectin-like receptor is involved in invasion of erythrocytes by plasmodium falciparum.glycophorin both in solution and inserted into liposomes blocks invasion of erythrocytes by the malaria parasite plasmodium falciparum. furthermore, one sugar, n-acetyl-d-glucosamine (glcnac), completely blocks invasion of the erythrocyte by this parasite. glcnac coupled to bovine serum albumin to prevent the sugar entering infected erythrocytes was at least 100,000 times more effective than glcnac alone. bovine serum albumin coupled to lactose or bovine serum albumin alone had no effect on inva ...19836341986
isolation and characterization of the plasma membrane of human erythrocytes infected with the malarial parasite plasmodium falciparum.human erythrocytes infected with the malarial parasite plasmodium falciparum were labeled metabolically with a mixture of 15 radioactive amino acids. when synchronously growing parasites were at the schizont stage of development infected cells were concentrated and purified by using a percoll-hypaque gradient. the plasma membrane of the infected erythrocyte, isolated by binding cells to a solid support (affi-gel 731, bio-rad), was less than 1% contaminated with parasite membranes. erythrocyte me ...19836341989
current therapy for plasmodium falciparum malaria in africa. 19836342164
[malaria prevention]. 19836342246
the wrb antigen, a receptor for plasmodium falciparum malaria, is located on a helical region of the major membrane sialoglycoprotein of human red blood cells.1. immunoprecipitation of periodate/nab3h4-labelled human erythrocytes using anti-wrightb (wrb) monoclonal antibodies showed that these antibodies specifically react with the major erythrocyte sialoglycoprotein alpha (glycophorin a). 2. similar experiments on erythrocytes from the only known individual lacking the wrb antigen but with otherwise normal sialoglycoproteins did not result in the immunoprecipitation of any sialoglycoprotein. 3. we suggest that the wrb antigen is located on an alpha-h ...19836342608
plasmodium falciparum: variations in p-aminobenzoic acid requirements as related to sulfadoxine sensitivity.plasmodium falciparum, thai strain fcm-5s sensitive to sulfadoxine, was grown continuously for 1 year in a medium with a low concentration of p-aminobenzoic acid (paba) without the emergence of a sulfadoxine-resistant line. the minimum paba-requirement for growth of sulfadoxine-sensitive thai strains in vitro was found to be 25.0 ng/ml, whereas resistant burmese and gambian strains completed their schizogony in the absence of paba. cultivation in dialyzed and nondialyzed human serum suggested th ...19836343109
continuous cultivation and improved drug responsiveness of plasmodium falciparum in p-aminobenzoic acid-deficient medium.long term cultivation of three culture lines of plasmodium falciparum was achieved in waymouth and rpmi media, both supplemented with 10% heat-inactivated human serum. observations on parasite multiplication over a 6-mo period showed no difference in the rate of parasite population increase. growth of asexual erythrocytic stages in waymouth medium was as good as that in rpmi when measured by the rate of glucose utilization and extent of 3h-isoleucine and 3h-methionine incorporation. responsivene ...19836343575
electron microscopy of knobs in plasmodium falciparum-infected erythrocytes. 19836343577
treatment of chloroquine-resistant malaria during pregnancy.a pregnant 36-year-old vietnamese refugee with chloroquine-resistant plasmodium falciparum infection was treated with pyrimethamine and a sulfonamide. this treatment produced rapid clearance of the patient's parasitemia and was associated with a resumption of normal fetal and uterine growth. because the other drugs effective against chloroquine-resistant p falciparum may produce uterine stimulation (quinine sulfate) or damage the fetal skeleton (tetracyclines), the pyrimethamine-sulfonamide comb ...19836343647
severe hypoglycemia and hyperinsulinemia in falciparum malaria.we studied the occurrence, clinical manifestations, and mechanism of hypoglycemia in patients with falciparum malaria in eastern thailand. hypoglycemia, which was often severe and recurrent, occurred in 17 patients, including 12 in a series of 151 patients with cerebral malaria. thirty episodes were investigated. plasma concentrations of insulin and c peptide were inappropriately high, and lactate and alanine concentrations were significantly higher than in patients with falciparum malaria who w ...19836343877
plasmodium falciparum strain-specific antibody blocks binding of infected erythrocytes to amelanotic melanoma cells.an important feature of plasmodium falciparum malaria which differentiates it from other human malarias is that erythrocytes infected with trophozoites and schizonts are not present in the peripheral blood but are sequestered along capillary and venular endothelium. infected erythrocytes attach via parasite-induced ultrastructural modifications on the surface of the infected cells, called 'knobs'. this sequestration may be important for parasite survival because it prevents infected erythrocytes ...19836343885
[malaria in las palmas. presentation of 20 cases]. 19836344153
chloroquine-resistant malaria. 19836344263
[vaccination against malaria. theoretical principles and practical perspectives]. 19836344307
end-tidal exhaled air for the in vitro maintenance of plasmodium falciparum. 19836344353
multiple drug resistance in falciparum malaria from brazil. 19836344356
the malumfashi project--an epidemiological, clinical and laboratory study. 19836344359
the activity of pyrimethamine and sulphadoxine against plasmodium falciparum determined by the in vitro microtechnique.the reported increase of infections of plasmodium falciparum which are no longer susceptible to a combination of pyrimethamine and sulphadoxine--fansidar--emphasizes the need for an in vitro test to determine the presence and prevalence of drug-resistant parasites. studies with the pyrimethamine-sensitive fcb strain and the pyrimethamine-resistant fta strain showed that the in vitro microtechnique can be used to determine differences in the susceptibility of these two strains to pyrimethamine an ...19836344364
the coombs direct antiglobulin test in kenyans.the direct antiglobulin test (dat) was performed on 243 subjects in kenya. a high incidence of positive dat was found in children with malaria of whom 70% had rbcs coated with igg, c3 and c4 either separately or together. only 12% of paediatric patients with conditions other than malaria had a positive dat. most positive dats in association with malaria occurred in children between 18 months and five years of age. there was a lower incidence of positive dat in kikuyu children from an area of low ...19836344365
[unsuccessful effect of sulfadoxine-pyrimethamine in the treatment of falciparum malaria in tanzania]. 19836344376
in vitro study of drug sensitivity of plasmodium falciparum: evaluation of a new semi-micro test.a modification of rieckmann's microtechnique was used to determine the drug sensitivity of plasmodium falciparum. the technique was found to be reliable and adequately sensitive with either blood from a malarial patient or strains of p. falciparum from in vitro continuous culture, with a success rate of 50%. minor variations in the method had little influence on the results. inhibition of maturation of parasites was compared with the inhibition of increase in parasitemia.19836344668
a simple field kit for the determination of drug susceptibility in plasmodium falciparum.a field kit has been developed which greatly simplifies the performance of the 48-hour in vitro test for drug resistance in plasmodium falciparum. the kit uses an easily reconstituted lyophilized culture medium, and requires only a fingerprick blood sample. in parallel tests with 13 isolates of p. falciparum in haiti, the new technique had a success rate equal to that of the previously described method, with comparable results in terms of parasite susceptibility in vitro to chloroquine and pyrim ...19836344669
red cell quinine concentrations in falciparum malaria.red cell concentrations of quinine were measured in cerebral malaria and in uncomplicated falciparum malaria both in the acute stage and 1 month after recovery. red cell quinine elimination half times were significantly shorter than the corresponding plasma half times in cerebral malaria and convalescent uncomplicated cases (p less than 0.001), but not in acute uncomplicated cases (p = 0.12). the ratio of red cell:plasma concentration fell progressively from the 2nd day (0.49) to the 6th day (0. ...19836344670
saimiri sciureus (karyotype 14-7): an alternative experimental model of plasmodium falciparum infection.in an earlier manuscript, we described the first phase of adaptation of the palo alto i strain of plasmodium falciparum to saimiri sciureus (squirrel monkeys). now, after more than 50 p. falciparum blood transfers in splenectomized saimiri, the parasite has become fully adapted to this experimental host. a highly reproducible pattern of infection is evident in these splenectomized animals, which is characterized by a rapidly rising parasitemia and a lethal outcome. in intact animals, the course ...19836344671
treatment of an acute case of plasmodium malariae malaria with mefloquine.mefloquine, a new antimalarial which has been effective in curing malaria due to plasmodium falciparum and p. vivax, was used for the first time in a patient infected with p. malariae. treatment was successful, and the relatively long parasite clearance time and fever clearance time were probably characteristic of p. malariae rather than true drug resistance.19836344673
[hemiplegia in pernicious attacks of plasmodium falciparum in children]. 19836344729
falciparum malaria: the urgent need for safe and effective drugs.the spread of multidrug-resistant strains of plasmodium falciparum poses an increasing threat to the effective treatment and prophylaxis of malaria. recent advances in determining the drug sensitivity of malaria parasites should promote the more rational use of standard or alternative antimalarials in areas with emerging or well-established drug resistance. the use of currently available alternative drugs is usually associated with more problems than that of the standard, synthetic antimalarials ...19836344762
a phase ii clinical trial of mefloquine in patients with chloroquine-resistant falciparum malaria in thailand.a double-blind, randomized, dose-finding, phase ii mefloquine trial was carried out in 147 adult male patients suffering from acute, uncomplicated, falciparum malaria and admitted to the hospital for tropical diseases, bangkok, between january 1980 and april 1981. mefloquine was administered as a single oral dose of 500, 750, or 1000 mg (base) in the form of the hydrochloride. the clinical and parasitological responses were satisfactory with all three dosage regimens. the cure rates for the 1000 ...19836345013
cooperation between antibodies and monocytes that inhibit in vitro proliferation of plasmodium falciparum.the cooperative effect between nonsensitized monocytes from normal individuals and malarial antibody in depressing parasite multiplication was investigated in an in vitro assay. the addition of purified normal monocytes to plasmodium falciparum cultures in the presence of serum from immune individuals markedly inhibited the proliferation of the parasite in vitro: the parasitemia observed was about 22 times lower than that in the presence of immune serum alone. this cooperative effect was found t ...19836345391
spirogermanium: a new drug with antimalarial activity against chloroquine-resistant plasmodium falciparum.spirogermanium, a new investigational drug of novel structure currently under clinical studies in various neoplastic diseases, has revealed significant in vitro activity against chloroquine-resistant (fcb, fta, fvo) and sensitive (fsl, fui, fh) strains of plasmodium falciparum. inhibition of the growth and maturation of parasites after 36-h exposures to spirogermanium started at concentrations ranging from 2.48 to 9.9 nm/ml. these concentrations appear to be within the range of spirogermanium pl ...19836345410
anion transport inhibitors as suppressors of plasmodium falciparum growth in in vitro cultures. 19836346050
malaria. cloning genes for antigens of plasmodium falciparum. 19836346103
immunization of owl monkeys to plasmodium falciparum with merozoites from cultures of a knobless clone.summary aotus trivirgatus monkeys of karyotype 2 were treated as follows. three received two injections of purified merozoites of a knobless (k-) clone of plasmodium falciparum with muramyl dipeptide as adjuvant; three received similar injections but with merozoites of a wild-type knobby (k+) strain; three controls received mdp with human erythrocytes in the amounts estimated to be present as contaminants in the merozoite preparations. a month after the second injection all nine monkeys were ino ...19836346229
specificity of auto-antibodies in malaria and the role of polyclonal activation.sera of 173 individuals living in a malaria endemic region in upper volta (donsé village) were screened for the presence of 14 auto-antibodies by the indirect immunofluorescent and/or passive haemagglutination techniques. at least one auto-antibody (aab) was detected in sera of 72% (124 out of 173) subjects. no differences in the aab frequency was observed in the sex or age groups. conversely, a significant relationship between a high frequency of auto-antibodies, high malaria antibody titres an ...19836346590
susceptibility of plasmodium falciparum to five drugs: an in vitro study of isolates mainly from thailand.this paper describes the results of testing the susceptibility of 60 isolates of the human malaria parasite plasmodium falciparum from thailand, and single isolates from five other countries, to five drugs: chloroquine, pyrimethamine, quinine, mefloquine and amodiaquine. the thai isolates were obtained from patients in three different regions of the country (chantaburi, songkhla and mae sod), and were first grown in culture by the trager-jensen candle-jar technique. samples were then exposed to ...19836346591
malaria infection of the placenta in the gambia, west africa; its incidence and relationship to stillbirth, birthweight and placental weight.the incidence of placental malaria at parturition and its effects on the conceptus have been investigated in the gambia, west africa. malarious placentae occurred in 1300 (20.2%) of 6427 singleton births, in 32 (18.6%) of 172 sets of twins and in none of six sets of triplets. plasmodium falciparum infections predominated; p. malariae or p. ovale infections were found in only nine instances. in the large group of single births placental malaria occurred less frequently (12.0%) in residents of urb ...19836346592
quantitation of red cell membrane associated immunoglobulin in children with plasmodium falciparum parasitaemia.erythrocyte-associated igg was measured on washed red cells from 26 children with p. falciparum parasitaemia using an immunoradiometric assay. the values obtained were compared with 15 age-matched controls living in the same area who did not have malaria. the amount of red cell-associated igg was related to the haemoglobin concentration, degree of parasitaemia and serum immunoglobulin level. the mean red cell-associated immunoglobulin for patients with malaria was 629 molecules per red cell (ran ...19836347242
[chloroquine resistance of plasmodium falciparum in africa: current status and proposals for surveillance methods].34 case-reports of type ri resistance of p. falciparum to chloroquine published between 1975 and 1982 are reviewed. the patients were non-immune travellers infected in east africa and in the neighbouring islands, especially tanzania, kenya and madagascar. the increase in number and level of resistance might be a problem in africa. a monitoring system of the patient and in the field is proposed and the possibilities of prevention and control are discussed.19836347413
[activity of monocytes of subjects sensitized to plasmodium falciparum: adherence and phagocytosis of merozoites in vitro. role of cytophylic antibodies].peripheral blood monocytes from subjects immune to malaria are able to ingest more efficiently p. falciparum merozoites under in vitro conditions than those from non-immune subjects. similar results were recorded when using monocytes from healthy controls preincubated with sera from immune individuals or igg prepared from these sera. the phagocytic process does not seem to be strain specific. in the conditions of our assay, no phagocytosis of parasitized erythrocytes was observed. the main targe ...19836347414
impaired cell-mediated immunity in plasmodium falciparum-infected patients with high-parasitemia and cerebral malaria.several cell-mediated functions were studied in vivo and in vitro in 63 thai patients with acute falciparum malaria, including 21 cases with cerebral manifestations and 10 cases with initial parasitemia over 10%. initial delayed cutaneous reactions to phytohemagglutinin and soluble protein antigens were negative in most cerebral malaria cases. in other patients, skin reactions were impaired or abolished as a direct function of parasitemia. no major alteration in the numbers of blood t and b lymp ...19836347486
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