Publications by authors named "Osamu Kaneko"

Background: The study of rodent malaria parasites has significantly advanced our understanding of malaria parasite biology and host responses to parasite infections. There are four well-characterized rodent malaria parasite species (Plasmodium yoelii, P. chabaudi, P.

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Malaria remains a key health and economic problem, particularly in sub-Saharan Africa. The emergence of artemisinin drug resistance (ART-R) parasite strains poses a serious threat to the control and elimination of this scourge. This is because artemisinin-based combination therapies (ACTs) remain the first-line treatment in the majority of malaria-endemic regions in Sub-Saharan Africa.

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Testing antimicrobial sensitivity is limited to schizont maturation assays, which preclude determining the IC50s of delayed action antimalarials such as doxycycline. Using as a model for , we determined the physiologically significant delayed death effect induced by doxycycline [IC, 1,401 ± 607 nM]. As expected, IC to chloroquine (20.

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  • Recent inhibitors targeting the KRAS G12C mutant protein have shown effectiveness in treating solid tumors, challenging the notion of KRAS as an undruggable target.
  • A specific compound, 1, was identified as a KRAS G12C inhibitor that works by covalently binding to the protein and demonstrated significant antitumor effects in cell lines and mouse models.
  • Further modifications to the compound led to the development of ASP6918, which displayed enhanced potency and successfully induced tumor regression in animal studies after oral administration.
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In recent phylogenetic studies, bat Polychromophilus and ungulate Plasmodium, two relatively understudied haemosporidian parasites within the Apicomplexa phylum, have often been overlooked. Instead, the focus has been primarily on haemosporidian parasites in primates, rodents, and birds. Several phylogenetic analyses of bat Polychromophilus have relied on limited datasets and short informative DNA sequences.

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The Asteraceae family is a promising source of bioactive compounds, such as the famous Asteraceae plants (pyrethrin) and (artemisinin). As a result of our series of phytochemical studies of the subtropical plants, two novel sesquiterpenes, named crossoseamines A and B in this study ( and , respectively), one undescribed coumarin-glucoside (), and eighteen known compounds (-) were isolated from the aerial part of (Asteraceae). The structures of isolated compounds were elucidated by spectroscopic methods, including 1D and 2D NMR experiments (H, C, DEPT, COSY, HSQC, HMBC, and NOESY), IR spectrum, circular dichroism spectrum (CD), and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS).

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malaria parasites use erythrocyte-binding-like (EBL) ligands to invade erythrocytes in their vertebrate host. EBLs are released from micronemes, which are secretory organelles located at the merozoite apical end and bind to erythrocyte surface receptors. Because of their essential nature, EBLs have been studied as vaccine candidates, such as the Duffy binding protein.

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  • - The study analyzed P. falciparum diversity and transmission in school-age children from Kinshasa, DRC, focusing on asymptomatic and symptomatic cases to inform malaria control efforts.
  • - Researchers characterized 438 DNA samples and found that certain alleles, like K1 in pfmsp1 and 3D7 in pfmsp2, were quite prevalent, with polyclonal infections occurring in 63% of samples.
  • - The results indicated low allelic diversity and a moderate intensity of malaria transmission, with higher multiplicity of infection linked to symptomatic cases and increased parasite levels. Further research in various transmission zones is suggested.
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  • Visceral leishmaniasis (VL) is a neglected tropical disease that has been increasing in Nepal, despite efforts to eliminate it since 2005.
  • A study analyzed 34,564 VL cases from 1980 to 2019, noting a rise in cases until 2006, with significant variations based on age, sex, and location.
  • The spread of VL to hilly and mountainous areas poses challenges for elimination efforts, highlighting the need for urgent control measures.
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Unlike malaria parasites in humans, non-human primates, rodents, and birds, ungulate malaria parasites and their vectors have received little attention. As a result, understanding of the hosts, vectors, and biology of ungulate malaria parasites has remained limited. In this study, we aimed to identify the vectors of the goat malaria parasite Plasmodium caprae.

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The lack of a long-term in vitro culture method has severely restricted the study of Plasmodium vivax, in part because it limits genetic manipulation and reverse genetics. We used the recently optimized Plasmodium cynomolgi Berok in vitro culture model to investigate the putative P. vivax drug resistance marker MDR1 Y976F.

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Zoonotic malaria due to Plasmodium knowlesi infection in Southeast Asia is sometimes life-threatening. Post-mortem examination of human knowlesi malaria cases showed sequestration of P. knowlesi-infected red blood cells (iRBCs) in blood vessels, which has been proposed to be linked to disease severity.

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  • RAS proteins are essential for cell growth and differentiation, but mutations can lead to cancer; RAS inhibitors are promising therapies yet considered hard to target.
  • Recent studies reveal that a new covalent inhibitor targeting the KRAS G12C mutation has shown effective results against solid tumors, offering hope for treatment.
  • A specific compound, identified as 7b, demonstrated strong anti-tumor effects and stability in metabolic tests, making it a promising candidate for cancer therapy.
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The absence of a routine continuous in vitro cultivation method for Plasmodium vivax, an important globally distributed parasite species causing malaria in humans, has restricted investigations to field and clinical sampling. Such a method has recently been developed for the Berok strain of P. cynomolgi, a parasite of macaques that has long been used as a model for P.

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Ungulate malaria parasites and their vectors are among the least studied when compared to other medically important species. As a result, a thorough understanding of ungulate malaria parasites, hosts, and mosquito vectors has been lacking, necessitating additional research efforts. This study aimed to identify the vector(s) of Plasmodium bubalis.

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Background: The emergence and spread of Plasmodium falciparum parasites resistant to antimalarial drugs constitutes an obstacle to malaria control and elimination. This study aimed to identify the prevalence of polymorphisms in pfk13, pfmdr1, pfdhfr, pfdhps and pfcrt genes in isolates from asymptomatic and symptomatic school-age children in Kinshasa.

Methods: Nested-PCR followed by sequencing was performed for the detection of pfk13, pfmdr1, pfdhfr, pfdhps and pfcrt polymorphisms.

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malaria parasites are obligate intracellular protozoans that use a unique form of locomotion, termed gliding motility, to move through host tissues and invade cells. The process is substrate dependent and powered by an actomyosin motor that drives the posterior translocation of extracellular adhesins which, in turn, propel the parasite forward. Gliding motility is essential for tissue translocation in the sporozoite and ookinete stages; however, the short-lived erythrocyte-invading merozoite stage has never been observed to undergo gliding movement.

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Plasmodium, the causative agents of malaria, are obligate intracellular organisms. In humans, pathogenesis is caused by the blood stage parasite, which multiplies within erythrocytes, thus erythrocyte invasion is an essential developmental step. Merozoite form parasites released into the blood stream coordinately secrets a panel of proteins from the microneme secretory organelles for gliding motility, establishment of a tight junction with a target naive erythrocyte, and subsequent internalization.

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Characterising the genomic variation and population dynamics of Plasmodium falciparum parasites in high transmission regions of Sub-Saharan Africa is crucial to the long-term efficacy of regional malaria elimination campaigns and eradication. Whole-genome sequencing (WGS) technologies can contribute towards understanding the epidemiology and structural variation landscape of P. falciparum populations, including those within the Lake Victoria basin, a region of intense transmission.

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Malaria remains a heavy global burden on human health, and it is important to understand the molecular and cellular biology of the parasite to find targets for drug and vaccine development. The mouse malaria model is an essential tool to characterize the function of identified molecules; however, robust technologies for targeted gene deletions are still poorly developed for the widely used rodent malaria parasite, Plasmodium yoelii. To overcome this problem, we established a DiCre-loxP inducible knockout (iKO) system in P.

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Lipid rafts, sterol-rich and sphingolipid-rich microdomains on the plasma membrane are important in processes like cell signaling, adhesion, and protein and lipid transport. The virulence of many eukaryotic parasites is related to raft microdomains on the cell membrane. In the malaria parasite Plasmodium falciparum, glycosylphosphatidylinositol-anchored proteins, which are important for invasion and are possible targets for vaccine development, are localized in the raft.

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Background: Plasmodium knowlesi is now the major cause of human malaria in Malaysia, complicating malaria control efforts that must attend to the elimination of multiple Plasmodium species. Recent advances in the cultivation of P. knowlesi erythrocytic-stage parasites in vitro, transformation with exogenous DNA, and infection of mosquitoes with gametocytes from culture have opened up studies of this pathogen without the need for resource-intensive and costly non-human primate (NHP) models.

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The Fukushima-Daiichi Nuclear Power Plant (FNPP) accident in March of 2011 released substantial amounts of radionuclides into the environment. We collected 4,957 deciduous teeth formed in children before the Fukushima accident to obtain precise control data for teeth formed after the accident. Radioactivity was measured using imaging plates (IP) and epidemiologically assessed using multivariate regression analysis.

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Plasmodium falciparum malaria parasites export several hundred proteins to the cytoplasm of infected red blood cells (RBCs) to modify the cell environment suitable for their growth. A Plasmodium translocon of exported proteins (PTEX) is necessary for both soluble and integral membrane proteins to cross the parasitophorous vacuole (PV) membrane surrounding the parasite inside the RBC. However, the molecular composition of the translocation complex for integral membrane proteins is not fully characterized, especially at the parasite plasma membrane.

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