| the crystal structure of p. knowlesi dbpalpha dbl domain and its implications for immune evasion. | plasmodium vivax invasion of human erythrocytes requires that the ligand domain of the duffy-binding protein (dbp) recognize its cognate erythrocyte receptor, making dbp a potential target for therapy. the recently determined crystal structure of the orthologous dbp ligand domain of the closely related simian malaria parasite plasmodium knowlesi provides insight into the molecular basis for receptor recognition and raises important questions about the mechanism of immune evasion employed by the ... | 2006 | 16876418 |
| [molecular identification of naturally acquired plasmodium knowlesi infection in a human case]. | to confirm the diagnosis of a human case with atypical vivax-malaria from yunnan province by molecular technique. | 2006 | 17094597 |
| stage-specific expression of 14-3-3 in asexual blood-stage plasmodium. | this paper reports the identification of 14-3-3 in plasmodium. 14-3-3 is an evolutionarily conserved protein that is most noted as a mediator in signal transduction events and cell cycle regulation. the complete cdna (approximately 2.6 kb) and gdna (approximately 3.4 kb) of a plasmodium knowlesi 14-3-3 (pk14-3-3) is reported. the gene has three introns; two near the beginning and one close to the end of the coding sequence. also reported, is the gdna of the plasmodium falciparum homologue (pf14- ... | 1999 | 10477181 |
| cross-reactivity studies of an anti-plasmodium vivax apical membrane antigen 1 monoclonal antibody: binding and structural characterisation. | apical membrane antigen 1 (ama1) has an important, but as yet uncharacterised, role in host cell invasion by the malaria parasite, plasmodium. the protein, which is quite conserved between plasmodium species, comprises an ectoplasmic region, a single transmembrane segment and a small cytoplasmic domain. the ectoplasmic region, which can induce protective immunity in animal models of human malaria, is a leading vaccine candidate that has entered clinical trials. the monoclonal antibody f8.12.19, ... | 2007 | 17229439 |
| variant antigen expression in malaria infections: posttranscriptional gene silencing, virulence and severe pathology. | | 2004 | 14747139 |
| factors shaping genetic variation in the mhc of natural non-human primate populations. | across a large distribution range, population-specific factors as well as pathogen-mediated selection may shape species genetic diversity in the major histocompatibility complex (mhc). we have studied genetic diversity and population differentiation in the mhc region of the southeast asian cynomolgus macaque (macaca fascicularis fascicularis), a species with large and discontinuous range, in order to investigate the role of demography vs selection. genetic variation was assessed at seven mhc mic ... | 2007 | 17854428 |
| protection of rhesus monkeys by a dna prime/poxvirus boost malaria vaccine depends on optimal dna priming and inclusion of blood stage antigens. | we have previously described a four antigen malaria vaccine consisting of dna plasmids boosted by recombinant poxviruses which protects a high percentage of rhesus monkeys against plasmodium knowlesi (pk) malaria. this is a multi-stage vaccine that includes two pre-erythrocytic antigens, pkcsp and pkssp2(trap), and two erythrocytic antigens, pkama-1 and pkmsp-1(42kd). the present study reports three further experiments where we investigate the effects of dna dose, timing, and formulation. we als ... | 2007 | 17957247 |
| evaluation of some adamantane-based synthetic trioxanes against plasmodium knowlesi in rhesus monkeys. | in our search for synthetic substitutes for artemisinin and its derivatives we had earlier prepared a series of adamantane-based 1, 2, 4-trioxanes 5a-c which had shown promising activity against p. berghei in swiss mice. we have further evaluated these and two new compounds (5d-e) against plasmodium knowlesi w1, a virulent malaria parasite in rhesus monkeys, in the dose range of 40-80 mg/kg x 5 days by intramuscular route. trioxanes 5b and 5c showed 100% protection and cure at 80 mg/kg x 5 days, ... | 2007 | 17976659 |
| meeting report: the molecular background of severe and complicated malaria. | | 2004 | 14747141 |
| alterations in some constituents of the monkey erythrocyte infected with plasmodium knowlesi as related to pigment formation. | | 1948 | 18109260 |
| [not available]. | | 1949 | 18129509 |
| asexual reproduction of plasmodium knowlesi in rhesus monkeys. | | 1949 | 18137136 |
| plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening. | until recently, plasmodium knowlesi malaria in humans was misdiagnosed as plasmodium malariae malaria. the objectives of the present study were to determine the geographic distribution of p. knowlesi malaria in the human population in malaysia and to investigate 4 suspected fatal cases. | 2008 | 18171245 |
| plasmodium knowlesi: the fifth human malaria parasite. | | 2008 | 18171246 |
| new selectable markers and single crossover integration for the highly versatile plasmodium knowlesi transfection system. | plasmodium knowlesi provides a highly versatile transfection system for malaria, since it enables rapid genetic modification of the parasite both in vivo as well as in vitro. however, it is not possible to perform multiple genetic manipulations within one parasite line because of a lack of selectable markers. in an effort to develop additional selectable markers for this parasite, positive and negative selectable markers that have recently been successfully used in plasmodium falciparum were tes ... | 2004 | 14747147 |
| monkey malaria in man. | | 2004 | 15464180 |
| phylogenetic and structural analysis of translationally controlled tumor proteins. | the translationally controlled tumor protein (tctp) is conserved in all eukaryotes studied thus far. recent evidence points to an important role for tctp in the induction of cell proliferation in animals through an interaction with g proteins. tctp may also constitute an intercellular secreted signal that modulates the immune response in the vertebrates. because of its sequence conservation and ubiquity, the analysis of its amino acid sequence divergence between different taxa may provide insigh ... | 2008 | 18392759 |
| human infections with plasmodium knowlesi, the philippines. | five human cases of infection with the simian malaria parasite plasmodium knowlesi from palawan, the philippines, were confirmed by nested pcr. this study suggests that this zoonotic infection is found across a relatively wide area in palawan and documents autochthonous cases in the country. | 2008 | 18439369 |
| naturally acquired human plasmodium knowlesi infection, singapore. | we report a case of naturally acquired plasmodium knowlesi in singapore, a malaria-free country. diagnosis was confirmed by pcr with validated species-specific primers. in industrialized countries, free-ranging primates are a potential source of p. knowlesi human infection. p. knowlesi infection is a differential diagnosis of febrile illness acquired in singapore. | 2008 | 18439370 |
| knowlesi malaria: newly emergent and of public health importance? | several questions on public health impact have arisen from the discovery of a large focus of the simian malaria parasite, plasmodium knowlesi, in the human population. p. knowlesi malaria is not newly emergent and was overlooked until molecular tools to distinguish between p. knowlesi and the morphologically similar plasmodium malariae became available. knowlesi malaria is a zoonosis that is widely distributed in southeast asia and can be fatal. information on knowlesi malaria should be included ... | 2008 | 18678527 |
| plasmodium knowlesi in humans, macaques and mosquitoes in peninsular malaysia. | abstract: | 2008 | 18710577 |
| monkey malaria in a european traveler returning from malaysia. | in 2007, a finnish traveler was infected in peninsular malaysia with plasmodium knowlesi, a parasite that usually causes malaria in monkeys. p. knowlesi has established itself as the fifth plasmodium species that can cause human malaria. the disease is potentially life-threatening in humans; clinicians and laboratory personnel should become more aware of this pathogen in travelers. | 2008 | 18760013 |
| a sicavar switching event in plasmodium knowlesi is associated with the dna rearrangement of conserved 3' non-coding sequences. | plasmodium knowlesi variant antigens are expressed at the surface of infected erythrocytes and are encoded by the schizont infected cell agglutination variant antigen (sicavar) multigene family. the 3' region of the sicavar gene locus encoding the 205 kda variant antigen expressed in the pk1(b+)1+ parasites was found to be altered compared to the pk1(a+) parental clone. here we report that this alteration is the result of a dna rearrangement and that the original and altered 205 sicavar alleles ... | 2004 | 15500914 |
| the genome of the simian and human malaria parasite plasmodium knowlesi. | plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast asia. plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). ... | 2008 | 18843368 |
| effect of blood and oxygen on plasmodium knowlesi infection in monkeys. | | 1948 | 18885740 |
| antibodies raised against receptor-binding domain of plasmodium knowlesi duffy binding protein inhibit erythrocyte invasion. | erythrocyte invasion by malaria parasites requires specific receptor-ligand interactions. plasmodium vivax and plasmodium knowlesi are completely dependent on binding the duffy blood group antigen to invade human erythrocytes. p. knowlesi invades rhesus erythrocytes by multiple pathways using the duffy antigen as well as alternative receptors. plasmodium falciparum binds sialic acid residues on glycophorin a as well as other sialic acid-independent receptors to invade human erythrocytes. parasit ... | 2002 | 11985860 |
| complement fixation with soluble antigens of plasmodium knowlesi and plasmodium lophurae. | | 1948 | 18932536 |
| methionine in the growth of the malarial parasite, plasmodium knowlesi. | | 1948 | 18938425 |
| identification and characterisation of rama homologues in rodent, simian and human malaria species. | | 2004 | 15555735 |
| use of malaria rapid diagnostic test to identify plasmodium knowlesi infection. | reports of human infection with plasmodium knowlesi, a monkey malaria, suggest that it and other nonhuman malaria species may be an emerging health problem. we report the use of a rapid test to supplement microscopic analysis in distinguishing the 5 malaria species that infect humans. | 2008 | 18976561 |
| analysis of structure and function of the giant protein pf332 in plasmodium falciparum. | virulence of plasmodium falciparum, the most lethal parasitic disease in humans, results in part from adhesiveness and increased rigidity of infected erythrocytes. pf332 is trafficked to the parasite-infected erythrocyte via maurer's clefts, structures for protein sorting and export in the host erythrocyte. this protein has a domain similar to the duffy-binding-like (dbl) domain, which functions by binding to receptors for adherence and invasion. to address structure of the pf332 dbl domain, we ... | 2009 | 19007413 |
| identification and bioinformatic characterization of a multidrug resistance associated protein (abcc) gene in plasmodium berghei. | the atp-binding cassette (abc) superfamily is one of the largest evolutionarily conserved families of proteins. abc proteins play key roles in cellular detoxification of endobiotics and xenobiotics. overexpression of certain abc proteins, among them the multidrug resistance associated protein (mrp), contributes to drug resistance in organisms ranging from human neoplastic cells to parasitic protozoa. in the present study, the plasmodium berghei mrp gene (pbmrp) was partially characterized and th ... | 2009 | 19118502 |
| swedish traveller with plasmodium knowlesi malaria after visiting malaysian borneo. | plasmodium knowlesi is typically found in nature in macaques and has recently been recognized as the fifth species of plasmodium causing malaria in human populations in south-east asia. a case of knowlesi malaria is described in a swedish man, who became ill after returning from a short visit to malaysian borneo in october 2006. his p. knowlesi infection was not detected using a rapid diagnostic test for malaria, but was confirmed by pcr and molecular characterization. he responded rapidly to tr ... | 2009 | 19146706 |
| [infectious diseases]. | in 2008, several publications have highlighted the role of climate change and globalization on the epidemiology of infectious diseases. studies have shown the extension towards europe of diseases such as crimea-congo fever (kosovo, turkey and bulgaria), leismaniosis (cyprus) and chikungunya virus infection (italy). the article also contains comments on plasmodium knowlesi, a newly identified cause of severe malaria in humans, as well as an update on human transmission of the h5ni avian influenza ... | 2009 | 19216322 |
| diagnosis of malaria by detection of plasmodial lactate dehydrogenase with an immunodot enzyme assay. | we have previously demonstrated, using polyclonal and monoclonal antibodies, that the lactate dehydrogenase (ldh) of malaria parasites is immunologically distinct from the host enzyme. the polyclonal antibodies, produced against the affinity purified plasmodial ldh (pldh) in rabbits, showed specificity to ldh of malaria parasites. in the present study, these anti-pldh polyclonal antibodies were used to develop an immunodiagnostic test (immunodot enzyme assay of plasmodial ldh) based on the detec ... | 2002 | 12148951 |
| sulphated tyrosines mediate association of chemokines and plasmodium vivax duffy binding protein with the duffy antigen/receptor for chemokines (darc). | plasmodium vivax is one of four plasmodium species that cause human malaria. p. vivax and a related simian malaria parasite, plasmodium knowlesi, invade erythrocytes by binding the duffy antigen/receptor for chemokines (darc) through their respective duffy binding proteins. here we show that tyrosines 30 and 41 of darc are modified by addition of sulphate groups, and that the sulphated tyrosine 41 is essential for association of the duffy binding proteins of p. vivax (pvdbp) and p. knowlesi (pkd ... | 2005 | 15720550 |
| differential prevalence of plasmodium infections and cryptic plasmodium knowlesi malaria in humans in thailand. | a case of human infection with plasmodium knowlesi has been recently discovered in thailand. to investigate the prevalence of this malaria species, a molecular-based survey was performed. | 2009 | 19284284 |
| plasmodium knowlesi: finally being recognized. | | 2009 | 19284287 |
| [therapeutic efficacy of naphthoquine phosphate combined with artemisinine against plasmodium knowlesi]. | to study the antimalarial activity of naphthoquine phosphate combined with artemisinine against plasmodium knowlesi in rhesus monkey. | 2008 | 19288919 |
| monkey malaria kills four humans. | four human deaths caused by plasmodium knowlesi, a simian malaria species, are stimulating a surge of public health interest and clinical vigilance in vulnerable areas of southeast asia. we, and other colleagues, emphasize that these cases, identified in malaysia, are a clear warning that health facilities and clinicians must rethink the diagnosis and treatment of malaria cases presumed to be caused by a less virulent human malaria species, plasmodium malariae. | 2009 | 19345613 |
| plasmodium knowlesi from archival blood films: further evidence that human infections are widely distributed and not newly emergent in malaysian borneo. | human infections with plasmodium knowlesi have been misdiagnosed by microscopy as plasmodium malariae due to their morphological similarities. although microscopy-identified p. malariae cases have been reported in the state of sarawak (malaysian borneo) as early as 1952, recent epidemiological studies suggest the absence of indigenous p. malariae infections. the present study aimed to determine the past incidence and distribution of p. knowlesi infections in the state of sarawak based on archiva ... | 2009 | 19358848 |
| in vitro antimalarial activity of nucleic acid precursor analogues in the simian malaria plasmodium knowlesi. | analogues of nucleic acid precursors were screened for antimalarial activity in plasmodium knowlesi by using an in vitro culture system. activity was assessed by the degree of inhibition of incorporation of l-[methyl-(14)c]methionine into protein and of [8-(14)c]adenosine and [6-(14)c]orotic acid into ribonucleic acid and deoxyribonucleic acid. the incorporation of adenosine or orotic acid was effectively inhibited by many of the compounds, including 3' analogues of purine nucleosides, many of t ... | 1974 | 15828165 |
| the reticulocyte binding-like proteins of p. knowlesi locate to the micronemes of merozoites and define two new members of this invasion ligand family. | members of the reticulocyte binding-like protein (rbl) family are merozoite-expressed proteins hypothesized to be essential for effective invasion of host erythrocytes. proteins of the rbl family were first defined as merozoite invasion ligands in plasmodium vivax, and subsequently in plasmodium falciparum and other malaria parasite species. comparative studies are providing insights regarding the complexity and evolution of this family and the existence of possible functionally alternative memb ... | 2009 | 19428658 |
| monkey malaria in humans: a diagnostic dilemma with conflicting laboratory data. | plasmodium knowlesi has recently been recognized as the fifth plasmodium species causing malaria in humans. diagnosis is difficult morphologically, and currently, available rapid tests have not been comprehensively evaluated with this pathogen. we report a case of p. knowlesi malaria that was confirmed after the initial clue of discordant microscopy and immunochromatographic results, highlighting the importance of molecular diagnostics in cases with the relevant clinical and epidemiologic histor ... | 2009 | 19478250 |
| a structural model of a seven-transmembrane helix receptor: the duffy antigen/receptor for chemokine (darc). | the duffy antigen/receptor for chemokine (darc) is an erythrocyte receptor for malaria parasites (plasmodium vivax and plasmodium knowlesi) and for chemokines. in contrast to other chemokine receptors, darc is a promiscuous receptor that binds chemokines of both cc and cxc classes. the four extracellular domains (ecds) of darc are essential for its interaction with chemokines, whilst the first (ecd1) is sufficient for the interaction with malaria erythrocyte-binding protein. in this study, we el ... | 2005 | 16046070 |
| cross-reactivity in rapid diagnostic tests between human malaria and zoonotic simian malaria parasite plasmodium knowlesi infections. | plasmodium knowlesi has a relatively broad host range extending to humans, in whom it causes zoonotic malaria. recent studies have shown that human infection with p. knowlesi is widely distributed in forested areas of southeast asia. in the present study, we evaluated commercial rapid diagnostic tests (rdts) for human malaria to assess their reactivity and sensitivity in detecting p. knowlesi parasites using blood samples obtained from infected monkeys. the blood samples were assayed using two c ... | 2009 | 19527797 |
| the novel plasmodium gallinaceum sporozoite protein, pg93, is preferentially expressed in the nucleus of oocyst sporozoites. | to study gene expression differences between oocyst and salivary gland sporozoites, cdna libraries previously constructed from the two sporozoite populations of the avian malaria parasite, plasmodium gallinaceum, were used in a subtractive hybridization protocol to isolate pg93, a novel oocyst sporozoite gene. pg93 encodes a putative approximately 76 kda translated protein that was predicted to localize to the nucleus. transcriptional analysis indicates that pg93 is preferentially expressed in o ... | 2005 | 16172495 |
| [plasmodium knowlesi--the fifth malaria. potentially lethal infection which can also affect tourists]. | | 2009 | 19579434 |
| clinical and laboratory features of human plasmodium knowlesi infection. | plasmodium knowlesi is increasingly recognized as a cause of human malaria in southeast asia but there are no detailed prospective clinical studies of naturally acquired infections. | 2009 | 19635025 |
| structural basis for duffy recognition by the malaria parasite duffy-binding-like domain. | molecular processes that govern pathogenic features of erythrocyte invasion and cytoadherence in malaria are reliant on plasmodium-specific duffy-binding-like domains (dbls). these cysteine-rich modules recognize diverse host cell-surface receptors during pathogenesis. dbls of parasite erythrocyte-binding proteins mediate invasion, and those from the antigenically variant p. falciparum erythrocyte membrane protein 1 (pfemp1) have been implicated in cytoadherence. the simian and human malarial pa ... | 2006 | 16372020 |
| disguising itself--insights into plasmodium falciparum binding and immune evasion from the dbl crystal structure. | duffy-binding like (dbl) domains are common to two different families of malaria proteins that are involved in parasite invasion of erythrocytes or cytoadhesion of infected erythrocytes. dbl domain crystal structures have recently been solved for two different erythrocyte binding ligands, eba-175 and the plasmodium knowlesi alpha duffy binding protein. these structures reveal different mechanisms for dbl binding and erythrocyte invasion. this review summarizes recent work on dbl domain binding a ... | 2006 | 16621067 |
| natural transmission of plasmodium knowlesi to humans by anopheles latens in sarawak, malaysia. | four species of malaria parasites are known to infect humans. a fifth species, plasmodium knowlesi, has been reported to infect humans in malaysian borneo. here we report for the first time the incrimination of anopheles latens as the vector of p. knowlesi among humans and monkeys in sarawak, malaysia. | 2006 | 16725166 |
| structure of the c-terminal domains of merozoite surface protein-1 from plasmodium knowlesi reveals a novel histidine binding site. | the protozoan parasite plasmodium causes malaria, with hundreds of millions of cases recorded annually. protection against malaria infection can be conferred by antibodies against merozoite surface protein (msp)-1, making it an attractive vaccine candidate. here we present the structure of the c-terminal domains of msp-1 (known as msp-1(19)) from plasmodium knowlesi. the structure reveals two tightly packed epidermal growth factor-like domains oriented head to tail. in domain 1, the molecule dis ... | 2003 | 12493733 |
| [human natural infection of plasmodium knowlesi]. | a blood film slide taken from a patient previously diagnosed as vivax malaria in mojiang county, yunnan province, showing atypical forms. the ring forms had multinuclei, and the late trophozoites trended to form band. the schizonts and gametocytes were somewhat alike to plasmodium vivax. pcr amplification confirmed that the patient was infected by p. knowlesi. | 2006 | 16866152 |
| identification and characterization of a conserved, stage-specific gene product of plasmodium falciparum recognized by parasite growth inhibitory antibodies. | we have identified a novel conserved protein of plasmodium falciparum, designated d13, that is stage-specifically expressed in asexual blood stages of the parasite. the predicted open reading frame (orf) d13 contains 863 amino acids with a calculated molecular mass of 99.7 kda and displays a repeat region composed of pentapeptide motives. northern blot analysis with lysates of synchronized blood stage parasites showed that d13 is highly expressed at the mrna level during schizogony. the first n' ... | 2003 | 12654839 |
| detection of plasmodium knowlesi by real-time polymerase chain reaction. | we previously developed a real-time polymerase chain reaction (pcr) assay for detection of the four plasmodium species that infect humans. recent studies have shown that natural transmission of the simian parasite plasmodium knowlesi to humans occurs frequently in southeast asia. we have expanded our pcr assay to include detection of p. knowlesi. | 2009 | 19706924 |
| global health surveillance and travelers' health. | monitoring disease trends among travelers can inform both pretravel advice and posttravel management. data from sentinel travelers upon their return to medically sophisticated environments can also benefit local populations in resource-limited countries. | 2009 | 19726984 |
| definition of structural elements in plasmodium vivax and p. knowlesi duffy-binding domains necessary for erythrocyte invasion. | plasmodium vivax and p. knowlesi use the duffy antigen as a receptor to invade human erythrocytes. duffy-binding ligands belong to a family of erythrocyte-binding proteins that bind erythrocyte receptors to mediate invasion. receptor-binding domains in erythrocyte-binding proteins lie in conserved cysteine-rich regions called duffy-binding-like domains. in the present study, we report an analysis of the overall three-dimensional architecture of p. vivax and p. knowlesi duffy-binding domains base ... | 2003 | 12775212 |
| in vivo study of human plasmodium knowlesi in macaca fascicularis. | plasmodium knowlesi is a malaria parasite of old world monkeys and is infectious to humans. in this study macaca fascicularis was used as a model to understand the host response to p. knowlesi using parasitological and haematological parameters. three m. fascicularis of either sex were experimentally infected with p. knowlesi erythrocytic parasites from humans. the pre-patent period for p. knowlesi infection in m. fascicularis ranged from seven to 14 days. the parasitemia observed was 13,686-24, ... | 2010 | 19765587 |
| human plasmodium knowlesi infection detected by rapid diagnostic tests for malaria. | we describe a pcr-confirmed case of plasmodium knowlesi infection with a high parasitemia level and clinical signs of severe malaria in a migrant worker from malaysian borneo in the netherlands. investigations showed that commercially available rapid antigen tests for detection of human plasmodium infections can detect p. knowlesi infections in humans. | 2009 | 19788819 |
| spurious amplification of a plasmodium vivax small-subunit rna gene by use of primers currently used to detect p. knowlesi. | the pcr primers commonly used to detect plasmodium knowlesi infections in humans were found to cross-react stochastically with p. vivax genomic dna. a nested primer set that targets one of the p. knowlesi small-subunit rrna genes was validated for specificity and for sensitivity of detection of <10 parasite genomes. | 2009 | 19812279 |
| emanuel wolinsky award. | | 2009 | 19824861 |
| the development of exoerythrocytic stages of plasmodium inui shortti in new world monkeys. | attempts are being made to adapt old world monkey malarial parasites to new world monkeys for vaccine and molecular studies. several of these (plasmodium cynomolgi berok, plasmodium fragile, and plasmodium knowlesi) grow readily but have failed to produce infective gametocytes. plasmodium gonderi and plasmodium fieldi develop in the liver after sporozoite inoculation but have failed to establish infection in the erythrocyte. anopheles dirus mosquitoes infected with plasmodium inui shortti by fee ... | 2003 | 12880277 |
| the terminal stages of plasmodium knowlesi infection in macaca mulatta. i. the clinical state: resuscitation by l-noradrenaline. | | 1959 | 14419715 |
| the terminal stages of plasmodium knowlesi infection in macaca mulatta. ii. the pharmacological action of l-noradrenaline and adrenaline. | | 1959 | 14419716 |
| plasmepsin 4, the food vacuole aspartic proteinase found in all plasmodium spp. infecting man. | plasmepsins are aspartic proteinases of the malaria parasite, and seven groups of plasmepsins have been identified by comparing genomic sequence data available for the genes encoding these enzymes from plasmodium falciparum, plasmodium vivax, plasmodium knowlesi, plasmodium berghei, and plasmodium yoelii. the food vacuole plasmepsins typified by plasmepsin 4 from p. falciparum (pfpm4) constitute one of these groups. genes encoding the ortholog of pfpm4 have been cloned from plasmodium ovale, pla ... | 2003 | 14550891 |
| targeting the plasmodium vivax duffy-binding protein. | plasmodium vivax requires interaction with the duffy antigen receptor for chemokines (darc) to enable its invasion of human erythrocytes. interaction with darc is mediated by the p. vivax duffy-binding protein (pvdbp) and is essential for junction formation, which is a key step in the invasion process. the receptor-binding domain of pvdbp maps to a conserved cysteine-rich region, referred to as region ii (pvrii). here, we review data on the interaction of pvrii with darc and explore the potentia ... | 2008 | 18023618 |
| is a monkey malaria from borneo an emerging human disease? | | 2008 | 18366329 |
| bionomics of anopheles latens in kapit, sarawak, malaysian borneo in relation to the transmission of zoonotic simian malaria parasite plasmodium knowlesi. | a large focus of human infections with plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques was discovered in the kapit division of sarawak, malaysian borneo. a study was initiated to identify the vectors of malaria, to elucidate where transmission is taking place and to understand the bionomics of the vectors in kapit. | 2008 | 18377652 |
| computational analysis of constraints on noncoding regions, coding regions and gene expression in relation to plasmodium phenotypic diversity. | malaria-causing plasmodium species exhibit marked differences including host choice and preference for invading particular cell types. the genetic bases of phenotypic differences between parasites can be understood, in part, by investigating constraints on gene expression and genic sequences, both coding and regulatory. | 2008 | 18769675 |
| complement fixation with soluble antigens of plasmodium knowlesi and plasmodium lophurae. | | 1948 | 18901426 |
| morphology and kinetics of the three distinct phases of red blood cell invasion by plasmodium falciparum merozoites. | the invasion of red blood cells (rbcs) is an essential event in the life cycle of all malaria-causing plasmodium parasites; however, there are major gaps in our knowledge of this process. here, we use video microscopy to address the kinetics of rbc invasion in the human malaria parasite plasmodium falciparum. under in vitro conditions merozoites generally recognise new target rbcs within 1 min of their release from their host rbc. parasite entry ensues and is complete on average 27.6s after prim ... | 2009 | 18952091 |
| the duration of immunity to plasmodium knowlesi malaria in rhesus monkeys. | rhesus monkeys with experimental plasmodium knowlesi infections of varying duration were treated with sodium sulfathiazole to sterilize the infection and after differing lengths of time were reinoculated intraperitoneally with homologous strains of the plasmodium, for the purpose of determining whether there is any acquired immunity to malaria in hosts from whom all parasites have been removed. two monkeys, one receiving sulfathiazole on the 2nd day of acute infection and the other on the 4th da ... | 1944 | 19871378 |
| plasmodium genomics: latest milestone. | our knowledge on comparative genomics of the malaria parasites has advanced a step forward with the publication of the genomes of two primate-infecting malaria parasites: plasmodium vivax and plasmodium knowlesi. even though the genomes of these organisms are the fifth and sixth plasmodium genomes to be sequenced, respectively, both have revealed previously unknown features, which are discussed in this month's genome watch. | 2009 | 19219050 |
| simian malaria in a u.s. traveler--new york, 2008. | four species of intraerythrocytic protozoa of the genus plasmodium (p. falciparum, p. vivax, p. ovale, and p. malariae) are known to cause malaria in humans. however, recent reports from asia suggest the possibility that a fifth malaria species, plasmodium knowlesi, is emerging as an important zoonotic human pathogen. although more than 20 species of plasmodium can infect nonhuman primates, until recently, naturally acquired human infections of simian malaria were viewed as rare events lacking p ... | 2009 | 19282815 |
| morphological features and differential counts of plasmodium knowlesi parasites in naturally acquired human infections. | human infections with plasmodium knowlesi, a simian malaria parasite, are more common than previously thought. they have been detected by molecular detection methods in various countries in southeast asia, where they were initially diagnosed by microscopy mainly as plasmodium malariae and at times, as plasmodium falciparum. there is a paucity of information on the morphology of p. knowlesi parasites and proportion of each erythrocytic stage in naturally acquired human infections. therefore, deta ... | 2009 | 19383118 |
| in silico studies on darc. | the duffy antigen/receptor for chemokine (darc) is a seven segment transmembrane protein. it was firstly discovered as a blood group antigen and was the first specific gene locus assigned to a specific autosome in man. it became more famous as an erythrocyte receptor for malaria parasites (plasmodium vivax and plasmodium knowlesi), and finally for chemokines. darc is an unorthodox chemokine receptor as (i) it binds chemokines of both cc and cxc classes and (ii) it lacks the asp-arg-tyr consensus ... | 2009 | 19519483 |
| knowlesi malaria in vietnam. | the simian malaria parasite plasmodium knowlesi is transmitted in the forests of southeast asia. symptomatic zoonotic knowlesi malaria in humans is widespread in the region and is associated with a history of spending time in the jungle. however, there are many settings where knowlesi transmission to humans would be expected but is not found. a recent report on the ra-glai population of southern central vietnam is taken as an example to help explain why this may be so. | 2009 | 19941646 |
| severe malaria - a case of fatal plasmodium knowlesi infection with post-mortem findings: a case report. | zoonotic malaria caused by plasmodium knowlesi is an important, but newly recognized, human pathogen. for the first time, post-mortem findings from a fatal case of knowlesi malaria are reported here. | 2010 | 20064229 |
| plasmodium knowlesi malaria in vietnam: some clarifications. | a recently published comment on a report of plasmodium knowlesi infections in vietnam states that this may not accurately represent the situation in the study area because the pcr primers used may cross-hybridize with plasmodium vivax. nevertheless, p. knowlesi infections have been confirmed by sequencing. in addition, a neighbour-joining tree based on the 18s s-type ssurrna gene shows that the vietnamese samples clearly cluster with the p. knowlesi isolates identified in malaysia and are distin ... | 2010 | 20082717 |
| plasmodium knowlesi: an important yet overlooked human malaria parasite. | | 2009 | 19567722 |
| [a fifth plasmodium that can cause malaria]. | since 2004, malaria with a "fifth" plasmodium, plasmodium knowlesi (common in macaque monkeys), has been diagnosed in a number of people in southeast asia. this article gives a short overview of the epidemiology, clinical picture, diagnostics and treatment of p. knowlesi infection. | 2010 | 20160773 |
| the pigment of the malarial parasites plasmodium knowlesi and plasmodium gallinaceum. | | 1947 | 20270803 |
| studies on malarial parasites; effects of ascorbic acid on malaria (plasmodium knowlesi) in monkeys. | | 1946 | 20277733 |
| [malaria and other risks]. | | 2010 | 20334791 |
| plasmodium knowlesi in human, indonesian borneo. | plasmodium knowlesi is now established as the fifth plasmodium species to cause malaria in humans. we describe a case of p. knowlesi infection acquired in indonesian borneo that was imported into australia. clinicians need to consider this diagnosis in a patient who has acquired malaria in forest areas of southeast asia. | 2010 | 20350383 |
| transgenic plasmodium knowlesi: relieving a bottleneck in malaria research? | plasmodium knowlesi is a primate malaria parasite that is phylogenetically close to the major human parasite plasmodium vivax. p. knowlesi causes life-threatening disease in humans, infects a wide range of non-human primates and is one of few malaria parasites amenable to cyclical in vitro propagation. a robust in vivo and in vitro genetic manipulation system has been developed for this parasite, enabling in vitro-in vivo shuttling of transgenes, which (together with recent characterization of i ... | 2009 | 19635679 |
| redefining the expressed prototype sicavar gene involved in plasmodium knowlesi antigenic variation. | the sicavar gene family, expressed at the surface of infected erythrocytes, is critical for antigenic variation in plasmodium knowlesi. when this family was discovered, a prototypic sicavar gene was characterized and defined by a 10-exon structure. the predicted 205-kda protein lacked a convincing signal peptide, but included a series of variable cysteine-rich modules, a transmembrane domain encoded by the penultimate exon, and a cytoplasmic domain encoded by the final highly conserved exon. the ... | 2009 | 19646264 |
| the malaria merozoite, forty years on. | the invasive blood stage of malaria parasites, merozoites, are complex entities specialized for the capture and entry of red blood cells. their potential for vaccination and other anti-malaria strategies have attracted much research attention over the last 40 years, and there is now a considerable body of data relating to their biology. in this article some of the major advances over this period and remaining challenges are reviewed. | 2009 | 19646305 |
| sterile protection against plasmodium knowlesi in rhesus monkeys from a malaria vaccine: comparison of heterologous prime boost strategies. | using newer vaccine platforms which have been effective against malaria in rodent models, we tested five immunization regimens against plasmodium knowlesi in rhesus monkeys. all vaccines included the same four p. knowlesi antigens: the pre-erythrocytic antigens csp, ssp2, and erythrocytic antigens ama1, msp1. we used four vaccine platforms for prime or boost vaccinations: plasmids (dna), alphavirus replicons (vrp), attenuated adenovirus serotype 5 (ad), or attenuated poxvirus (pox). these four p ... | 2009 | 19668343 |
| plasmodium knowlesi infections in a small number of non-immune natural hosts (macaca fascicularis) and in rhesus monkeys (m. mulatta). | the natural host of plasmodium knowlesi is the kra monkey, macaca fascicularis, but this parasite, initially mistaken for p. malariae, is now infecting humans in some areas of southeast asia. here we present data from experiments performed in the 1970s in which sera from a few naive m. fascicularis, taken in the course of a first infection, exhibited rapidly rising inhibition of in vitro replication of p. knowlesi. the results were compared with sera from p. knowlesi-infected rhesus monkeys that ... | 2010 | 19699500 |
| anopheles dirus co-infection with human and monkey malaria parasites in vietnam. | the feasibility of identifying parasite dna and specific mrnas from wild-caught anopheles dirus mosquitoes was assessed using dried mosquito salivary glands preserved on filter paper. we were able to detect plasmodium falciparum, plasmodium vivax, plasmodium malariae and plasmodium knowlesi dna by conventional pcr and, furthermore, detected p. falciparum gametocyte-specific genes, pfg377 and pfs16 mrna, p. knowlesi circumsporozoite protein (csp) and sporozoite surface protein 2 (ssp2) mrna by re ... | 2009 | 19703460 |
| evaluation of a loop-mediated isothermal amplification method as a tool for diagnosis of infection by the zoonotic simian malaria parasite plasmodium knowlesi. | loop-mediated isothermal amplification (lamp) is a novel method that rapidly amplifies target dna with high specificity under isothermal conditions. it has been applied as a diagnostic tool for several infectious diseases, including viral, bacterial, and parasitic diseases. in the present study, we developed a lamp method for the molecular diagnosis of plasmodium knowlesi infection (pklamp) and evaluated its sensitivity, specificity, and clinical applicability. we designed three sets of pklamp p ... | 2010 | 20444968 |
| characterisation of the phosphatidylinositol synthase gene of plasmodium species. | phosphatidylinositol (pi) is a versatile lipid that not only serves as a structural component of cellular membranes, but also plays important roles in membrane anchorage of proteins and in signal transduction through distinct phosphorylated derivatives of the inositol head group. pi is synthesised by pi synthase from cdp-diacylglycerol and myo-inositol. the enzymatic activity in plasmodium falciparum and p. knowlesi has previously been characterised at the biochemical level. here we characterise ... | 2007 | 17223316 |
| [plasmodium knowlesi--the fifth species causing human malaria]. | four species have been known to bring on human malaria, the most severe disease being caused by plasmodium falciparum. in 2007, after returning from malaysia, a finnish tourist was found to be infected with a fifth plasmodium species, p. knowlesi which usually infects macaques. over the past few years, hundreds of human cases have been found in malaysia. the clinical disease caused by p. knowlesi appears less severe than p. falciparum infection, but more severe than infection with other malaria- ... | 2010 | 20486493 |
| diagnostic difficulties with plasmodium knowlesi infection in humans. | | 2010 | 20507769 |
| plasmodium knowlesi in humans: a review on the role of its vectors in malaysia. | plasmodium knowlesi in humans is life threatening, is on the increase and has been reported from most states in malaysia. anopheles latens and anopheles cracens have been incriminated as vectors. malaria is now a zoonoses and is occurring in malaria free areas of malaysia. it is also a threat to eco-tourism. the importance of the vectors and possible control measures is reviewed here. | 2010 | 20562807 |
| management of plasmodium knowlesi malaria without pcr confirmation. | plasmodium knowlesi morphologically resembles p. malariae; pcr assays are able to differentiate between the 2 species correctly. however, pcr is not available in many hospitals in p. knowlesi endemic areas, particularly in southeast asia. in places where pcr is not available, anti-malarial drugs for p. malariae or other non-p. falciparum or p. falciparum species are effective against p. knowlesi. even with a wrong diagnosis of another malaria species by light microscopy instead of p. knowlesi, t ... | 2010 | 20578477 |
| molecular epidemiological investigation of plasmodium knowlesi in humans and macaques in singapore. | singapore reported its first locally acquired human plasmodium knowlesi infection in 2007, involving a soldier who had undergone training in a forested area where long-tailed macaques are frequently seen. comprehensive disease surveillance and monitoring system that was set up after the initial case detected four additional human p. knowlesi cases in 2007 and one in 2008. all involved military personnel who had undergone training in the forested area, and none had traveled out of singapore 1 mon ... | 2011 | 20586605 |
| in vitro growth and multiplication of the malaria parasite, plasmodium knowlesi. | | 1945 | 17799502 |