Publications by authors named "Pak Prayoga"
Article Synopsis
- Splenomegaly, or spleen enlargement, is commonly found in patients with malarial anemia caused by Plasmodium falciparum or P. vivax, but the reasons for this connection are not fully understood.
- A study in Papua, Indonesia measured red blood cell (RBC) concentrations in the spleens of 37 patients, discovering that spleen size correlated positively with the amount of red-pulp and negatively with white-pulp, indicating a relationship between spleen composition and size.
- The research revealed that retained RBCs, primarily uninfected, accounted for significant blood loss in P. falciparum infections, and this retention correlated negatively with hemoglobin levels and circulating RBC counts, highlighting the impact
Severe malaria after splenectomy has been reported with infections with Plasmodium falciparum, Plasmodium knowlesi, and Plasmodium malariae, but is less well-characterized with Plasmodium vivax. We describe a case of severe P. vivax malaria with hypotension, prostration, and acute kidney injury occurring 2 months after splenectomy in Papua, Indonesia.
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- Asymptomatic infections of P. falciparum malaria in adults may hinder clinical immunity rather than support it, serving as a reservoir for the parasite and aiding its transmission.
- Researchers used a systems approach involving antibody responses and cell profiling to study the immune responses in individuals with symptomatic and asymptomatic malaria, linking certain immune cell profiles to a lower risk of clinical malaria.
- Findings indicate that while some immune responses exist, asymptomatic infections also promote immunosuppressive mechanisms that could undermine effective immune control and vaccine responsiveness against malaria.
Drug resistant Plasmodium parasites are a major threat to malaria control and elimination. After reports of high levels of multidrug resistant P. falciparum and P.
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- The study explores the complex role of IFN-γ in malaria, particularly its influence on T follicular helper cells and memory B cells, which are crucial for effective antibody responses and immunity.
- Through single-cell mass cytometry, distinct populations of CD4+ T cells with the T-bet factor were identified, showing varying risks for Plasmodium vivax malaria outcomes, indicating that inflammation can sometimes be beneficial.
- Additionally, specific types of memory B cells and T cell subsets were linked to reduced risk of symptomatic malaria, while others contributed to protection against asymptomatic infections, highlighting the need for both antibody and cell-mediated immunity in managing malaria.
Background: A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax. The mechanisms underlying this intense tropism are not clear. We hypothesised that immature reticulocytes, in which P.
View Article and Find Full Text PDFBackground: Neutrophil activation results in Plasmodium parasite killing in vitro, but neutrophil products including neutrophil extracellular traps (NETs) mediate host organ damage and may contribute to severe malaria. The role of NETs in the pathogenesis of severe malaria has not been examined.
Methods: In Papua, Indonesia, we enrolled adults with symptomatic Plasmodium falciparum (n = 47 uncomplicated, n = 8 severe), Plasmodium vivax (n = 37), or Plasmodium malariae (n = 14) malaria; asymptomatic P falciparum (n = 19) or P vivax (n = 21) parasitemia; and healthy adults (n = 23) without parasitemia.
High-grade chloroquine (CQ) resistance has emerged in both and The aim of the present study was to investigate the phenotypic differences of CQ resistance in both of these species and the ability of known CQ resistance reversal agents (CQRRAs) to alter CQ susceptibility. Between April 2015 and April 2016, the potential of verapamil (VP), mibefradil (MF), L703,606 (L7), and primaquine (PQ) to reverse CQ resistance was assessed in 46 and 34 clinical isolates in Papua, Indonesia, where CQ resistance is present in both species, using a modified schizont maturation assay. In , CQ 50% inhibitory concentrations (ICs) were reduced when CQ was combined with VP (1.
View Article and Find Full Text PDFBackground: In vitro drug susceptibility testing of malaria parasites remains an important component of surveillance for anti-malarial drug resistance. The half-maximal inhibition of growth (IC50) is the most commonly reported parameter expressing drug susceptibility, derived by a variety of statistical approaches, each with its own advantages and disadvantages.
Methods: In this study, licensed computer programs WinNonlin and GraphPad Prism 6.
Background: The emergence and spread of multidrug-resistant Plasmodium falciparum and Plasmodium vivax highlights the need for objective measures of ex vivo drug susceptibility. Flow cytometry (FC) has potential to provide a robust and rapid quantification of ex vivo parasite growth.
Methods: Field isolates from Papua, Indonesia, underwent ex vivo drug susceptibility testing against chloroquine, amodiaquine, piperaquine, mefloquine, and artesunate.
The declining efficacy of artemisinin derivatives against Plasmodium falciparum highlights the urgent need to identify alternative highly potent compounds for the treatment of malaria. In Papua Indonesia, where multidrug resistance has been documented against both P. falciparum and P.
View Article and Find Full Text PDFFerroquine (FQ; SSR97193), a ferrocene-containing 4-aminoquinoline derivate, has potent in vitro efficacy against chloroquine (CQ)-resistant Plasmodium falciparum and CQ-sensitive P. vivax. In the current study, ex vivo FQ activity was tested in multidrug-resistant P.
View Article and Find Full Text PDFHistone acetylation plays an important role in regulating gene transcription and silencing in Plasmodium falciparum. Histone deacetylase (HDAC) inhibitors, particularly those of the hydroxamate class, have been shown to have potent in vitro activity against drug-resistant and -sensitive laboratory strains of P. falciparum, raising their potential as a new class of antimalarial compounds.
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