| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| [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 |
| 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 |
| [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 |
| 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 |
| exchange transfusion in falciparum malaria. | | 1990 | 1967774 |
| 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 |
| runway malaria. | | 1990 | 1968192 |
| controlled trial of exchange transfusion in falciparum malaria. | | 1990 | 1968572 |
| 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 |
| the effects of plasmodium falciparum malaria on immune control of b lymphocytes in gambian children. | children living in hyperendemic malarious regions have high immunoglobulin levels and an increased frequency of burkitt's lymphoma. in a study of gambian children which endeavours to explain these findings we showed that acute p. falciparum malaria caused spontaneous activation and growth of their b lymphocytes in vitro. a high proportion of these cells contained epstein-barr nuclear antigen (ebna). in ancillary experiments aimed at explaining these findings. cd4 helper cells from adult donors w ... | 1990 | 1972671 |
| defective in vitro production of anti-plasmodium falciparum antibodies in some malaria-immune subjects. | the cell requirements for immunoglobulin (ig) and plasmodium falciparum-specific antibody production in the presence of schizont-enriched malaria antigen (m.ag) were studied in vitro. cell donors were healthy immune adult africans and europeans who had experienced single p. falciparum acute infection. in the presence of m.ag a dose-dependent increase in polyclonal igm and igg levels was observed with t/b cell cultures from 4/4 european and from 4/14 african donors (high-ig producers). in 10/14 a ... | 1990 | 1973078 |
| emergence of mefloquine-resistant malaria in africa without drug pressure. | | 1990 | 1973246 |
| field study of cyproheptadine/chloroquine synergism in falciparum malaria. | | 1990 | 1973247 |
| efficacy of pyrimethamine/sulfadoxine in uncomplicated severe falciparum malaria in kenya. | | 1990 | 1973506 |
| reversal of drug-resistant falciparum malaria by calcium antagonists: potential for host cell toxicity. | agents capable of reversing multidrug resistance (mdr) in falciparum malaria were investigated for potentiation of chloroquine accumulation and toxicity in a cell culture system. verapamil, its analog ro11-2933, and desipramine caused a dose-dependent increase in the accumulation of chloroquine (cq) within human and mouse hepatocytes but not human lung cells. only those cells in which drug accumulation was enhanced by reversing agents reacted positively for p-glycoprotein (pgp)--the putative med ... | 1990 | 1975136 |
| treatment of malaria with sulfadoxine/pyrimethamine: note of caution. | | 1990 | 1975290 |
| halofantrine to prevent falciparum malaria on return from malarious areas. | | 1990 | 1975358 |
| malaria chemoprophylaxis: why mefloquine? | | 1990 | 1976167 |
| hypoglycaemia and cerebral malaria. | | 1990 | 1976969 |
| neurological sequelae of cerebral malaria in children. | out of 604 gambian children admitted with falciparum malaria to one hospital between september and december, 1988, 308 had cerebral malaria and 203 were severely anaemic (haemoglobin less than 60 g/l). 14% of those with cerebral malaria died, as did 7.8% of those with severe anaemia. 32 (12%) of children surviving cerebral malaria had residual neurological deficit. 69 other children were admitted with clinical features strongly suggestive of cerebral malaria but with negative blood films; 16 of ... | 1990 | 1977027 |
| tnf concentration in fatal cerebral, non-fatal cerebral, and uncomplicated plasmodium falciparum malaria. | plasma levels of tumour necrosis factor (tnf) were significantly higher in 178 gambian children with uncomplicated malaria due to plasmodium falciparum than in 178 children with other illnesses. 110 children with cerebral malaria were studied shortly after admission to hospital; 28 subsequently died. compared with the children with uncomplicated malaria, mean plasma tnf levels were twice as high in cerebral malaria survivors and ten times as high in the fatal cases. although high tnf levels were ... | 1990 | 1978068 |
| cross-resistance between mefloquine and halofantrine. | | 1990 | 1978108 |
| severe malaria in a provincial hospital in vietnam. | | 1990 | 1978136 |
| cerebral malaria in children. | cerebral malaria is a rapidly progressive encephalopathy with up to 50% mortality. a cardinal feature is the massing of red cells containing mature plasmodium falciparum within the cerebral capillaries. adhesion of these parasitised red cells to endothelium, an event which may initiate cerebral malaria, is being studied at the molecular level. however, the relevance of these studies to the pathophysiology and treatment of human cerebral malaria is uncertain. although chloroquine is still widely ... | 1990 | 1978171 |
| anti-hcv false positivity in malaria. | | 1990 | 1978891 |
| human cerebral malaria: association with erythrocyte rosetting and lack of anti-rosetting antibodies. | plasmodium falciparum isolates from 24 gambian children with cerebral malaria and 57 children with mild forms of the disease were assessed for their ability to form erythrocyte rosettes. all isolates from the children with cerebral malaria were able to form rosettes, whereas those from children with mild forms of the disease did not form rosettes, or had a significantly lower rosetting rate. plasma of children with cerebral malaria lacked anti-rosetting activity, whereas plasma of children with ... | 1990 | 1979090 |
| antibodies to plasmodium falciparum in an indigenous population from a malaria endemic area of malaysia. | indirect fluorescent antibody (ifa) tests and enzyme-linked immunosorbent assays (elisa) were used to measure antibodies to plasmodium falciparum in an indigenous population in an area of malaysia with high malaria prevalence. the results of three surveys were analyzed to examine the relation of these serologic measures with age, parasite rate, and spleen size. for children 0-4 years old, increasing spleen size was associated with an increasing likelihood of malaria parasitemia, while for 5-9 ye ... | 1990 | 1980570 |
| malaria and its treatment in rural villages of aboh mbaise, imo state, nigeria. | we examined the malaria situation among 489 children under 5 years of age in the rural villages of aboh mbaise, nigeria, using a combination of a standard questionnaire technique and laboratory diagnosis to confirm clinical observations. the results show a high prevalence rate of 52.8% for plasmodium falciparum in this area. the geometric mean parasite density (gmpd) was 19,361.4/mm3. the proportion of children with fever and/or parasitaemia was not related to age, although the numbers in the fe ... | 1990 | 1980800 |
| mutations with multiple independent origins in surface antigens mark the targets of biological selective pressure. | this manuscript documents the existence and importance of a small subset of mutations in plasmodium falciparum genes that continually reoccur in separated populations. here we describe how to identify recurrent mutations using a novel application of pre-existing computer programs designed to trace genealogy. perhaps the most striking example of this phenomenon occurs in the cytotoxic t-cell epitope of a malaria surface antigen, the circumsporozoite (cs) protein of p. falciparum, where identical ... | 1990 | 1980908 |
| peptide analysis of the t cell response to the malaria circumsporozoite (cs) protein. | the t cell response to the circumsporozoite (cs) protein is still not well understood. there is still not agreement on the degree of immunological non-responsiveness or even on the basic question of whether the response to native cs protein requires t cells at all. recombinant proteins and synthetic peptides are tools that are helping us learn the basics of the immune response to this protein. here, the human and murine responses to the protein are probed using these valuable research tools. the ... | 1990 | 1980909 |
| hepatic phase of malaria is the target of cellular mechanisms induced by the previous and the subsequent stages. a crucial role for liver nonparenchymal cells. | both the sporozoites and the erythrocytic stages can modulate the hepatic phase by cytokines, notably ifn-gamma, tnf and il-6, either directly or as a result of a cascade of events, and by mhc-restricted and antibody-dependent cell-mediated cytotoxicity. the role played by cd8+ t cells in inducing protective immunity against pre-erythrocytic stages is clearly established. the potential interest of triggering peptide-primed cd4+ t cells has to be considered regarding protection. indeed, cd4+ t ce ... | 1990 | 1980910 |
| recommendations for action and research from a symposium and workshop on the complications, management and prevention of malaria. the roche asian research foundation. | | 1990 | 1981632 |
| metabolism of glutamine in erythrocytes infected with the human malaria parasite: plasmodium falciparum. | the metabolism of glutamine was studied in erythrocytes infected with plasmodium falciparum, comparatively to normal cells, in presence or not of don (6-diazo-5-oxo-l-norleucine) or acivicin, two glutamine antagonists which have been shown to inhibit the growth of p. falciparum in vitro. extracellular glutamine was partially converted into glutamate using two routes corresponding to gamma-glutamyl transpeptidase (ggt) and glutaminase activities. in cells infected with mature trophozoites, the ob ... | 1990 | 1982204 |
| polymorphism of the trap gene of plasmodium falciparum. | natural sequence variation of the thrombospondin related anonymous protein (trap) gene of plasmodium falciparum has been investigated by dna analysis following the polymerase chain reaction amplification, and this shows the gene to be highly polymorphic. the region containing the sequence motif trp-ser-pro-cys-ser-val-thr-cys-gly (wspcsvtcg), common to trap, the circumsporozoite protein, properdin, and thrombospondin, was invariant. elsewhere in the molecule, over 50 amino acid substitutions are ... | 1990 | 1983036 |
| emetine resistant mutants of entamoeba histolytica overexpress mrnas for multidrug resistance. | although drug therapy is critical for control of amoebiasis, little is known about mechanisms of drug resistance by e. histolytica parasites. here we tested the hypothesis that multidrug resistant (mdr) amoeba mutants, similar to mdr tumor cells, are drug resistant based upon overexpression of a p-glycoprotein pump that effluxes drugs from the cells. using primers to conserved regions of the human p-glycoprotein and the polymerase chain reaction (pcr), we identified multiple 344 base par segment ... | 1990 | 1983787 |
| failure of mefloquine prophylaxis in east africa. | | 1991 | 1984183 |
| tumor necrosis factor and severe malaria. | to investigate the relation of tumor necrosis factor-alpha (tnf alpha) to plasmodium falciparum infection, plasma tnf alpha concentrations were measured in zairian children with severe malaria, mild malaria, or other illnesses. the initial geometric mean plasma concentration of tnf alpha among 61 children with p. falciparum infection, (71 pg/ml) was higher than the level in 26 severely ill, aparasitemic children (10 pg/ml; p less than .001). among 29 parasitemic children, initial geometric mean ... | 1991 | 1984482 |
| effectiveness and tolerance of long-term malaria prophylaxis with mefloquine. need for a better dosing regimen. | to measure the effectiveness and tolerance of long-term malaria prophylaxis with mefloquine, the incidence of plasmodium falciparum malaria and of adverse reactions was compared in peace corps volunteers in west africa who took mefloquine every 2 weeks and in volunteers who took chloroquine phosphate weekly. mefloquine was only 63% more effective than chloroquine; the monthly incidence of p falciparum infections was one case per 100 volunteers who took mefloquine and 2.7 cases per 100 volunteers ... | 1991 | 1984534 |
| imported plasmodium falciparum malaria in american travelers to africa. implications for prevention strategies. | data from the us national malaria surveillance system were analyzed to assess characteristics of travelers who acquired plasmodium falciparum infections in africa and evaluate the impact of chloroquine resistance on the incidence of imported malaria. although the number of cases acquired in east africa has stabilized, the number of imported p falciparum infections acquired in west africa increased threefold from 1985 to 1988, and the proportion of travelers who reported failure of chloroquine pr ... | 1991 | 1984539 |
| prevention of malaria. | | 1991 | 1984542 |
| assessment of the protective value of antibodies to the plasmodium falciparum ring-infected erythrocyte surface antigen (resa): an epidemiologic study in madagascar. | the ring-infected erythrocyte surface antigen (resa), a plasmodium falciparum merozoite antigen, is a major vaccine candidate against falciparum malaria. to investigate the protective role of antibodies to resa and its 4-mer, 8-mer, and 11-mer repeated amino acid sequences under conditions of natural exposure, a case-control and a cohort study were carried out in 1988 in a rural community in madagascar where malaria reappeared recently. fifty cases with greater than 1,000 p. falciparum per micro ... | 1991 | 1985446 |
| long-term chloroquine-proguanil malaria prophylaxis in a nonimmune pediatric population. | | 1991 | 1986083 |
| initial extracellular forms of plasmodium falciparum: their ultrastructure and their definition with monoclonal antibodies. | merozoites of the erythrocytic stage of the human malaria parasite plasmodium falciparum, when placed under appropriate conditions in a culture medium with erythrocyte extract, differentiate into early trophic forms. these forms have much the same ultrastructure as rings of the same age that have developed intracellularly and have then been freed from their host cells by immune lysis. however, these forms differ in two respects: the extracellular forms have only their single plasma membrane, whe ... | 1991 | 1986385 |
| lipid traffic between high density lipoproteins and plasmodium falciparum-infected red blood cells. | several intraerythrocytic growth cycles of plasmodium falciparum could be achieved in vitro using a serum free medium supplemented only with a human high density lipoprotein (hdl) fraction (d = 1.063-1.210). the parasitemia obtained was similar to that in standard culture medium containing human serum. the parasite development was incomplete with the low density lipoprotein (ldl) fraction and did not occur with the vldl fraction. the lipid traffic from hdl to the infected erythrocytes was demons ... | 1991 | 1988461 |
| trat: a powerful carrier molecule for the stimulation of immune responses to protein and peptide antigens. | a number of integral membrane proteins (imps) isolated from escherichia coli have been examined for their ability to generate serum antibody responses in the absence of adjuvant. these proteins were found to stimulate high titers of serum antibody when injected into rabbits or mice in saline. the antibody titers elicited were not significantly increased by the addition of a powerful adjuvant such as ifa. covalent conjugation of bsa, of the dnp group, and of a peptide ag from plasmodium falciparu ... | 1991 | 1988496 |
| antibodies to human t lymphotropic virus type i in a population from the philippines: evidence for cross-reactivity with plasmodium falciparum. | residents of two areas in the philippines were tested for human t lymphotropic virus type i (htlv-i): napsan, a site endemic for malaria, and a nonmalarious site, bacolod. by elisa, 30% of the 1743 napsan residents were positive. western blot immunoreactivity with two or more htlv-i proteins was present in 81% of the elisa positives; however, there was no reactivity with the env proteins. the frequency of this indeterminate immunoreactivity increased with the malaria antibody titer. none of the ... | 1991 | 1988510 |
| an iron-carboxylate bond links the heme units of malaria pigment. | the intraerythrocytic malaria parasite uses hemoglobin as a major nutrient source. digestion of hemoglobin releases heme, which the parasite converts into an insoluble microcrystalline material called hemozoin or malaria pigment. we have purified hemozoin from the human malaria organism plasmodium falciparum and have used infrared spectroscopy, x-ray absorption spectroscopy, and chemical synthesis to determine its structure. the molecule consists of an unusual polymer of hemes linked between the ... | 1991 | 1988933 |
| structural and antigenic polymorphism of the 35- to 48-kilodalton merozoite surface antigen (msa-2) of the malaria parasite plasmodium falciparum. | merozoite surface antigen msa-2 of the human parasite plasmodium falciparum is being considered for the development of a malaria vaccine. the antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of msa-2 among 25 parasite isolates. the variants are grouped into two major serogroups, a and b. genes encoding two different variants from serogroup a have been sequenced, and their dna together with deduced amino acid sequences were compared with sequences ... | 1991 | 1990294 |