519 results match your criteria: "Institute of Tropical Medicine NEKKEN[Affiliation]"

The roles of BST-2 in murine B cell development and on virus propagation.

Microbiol Immunol

March 2023

Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.

The bone marrow (BM) stromal cell antigen-2 (BST-2), also known as tetherin, CD317, PDCA-1, or HM1.24, is a membrane protein overexpressed in several types of tumors and may act as a promising target for cancer treatment via antibody-dependent cellular cytotoxicity. BST-2 is also expressed in human BM stromal cells (BMSC), which support B cell development.

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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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Background: Dietary Diversity (DD) is an important component of Infant and Young Child Nutrition (IYCN). Globally, it is recommended that children aged 6-23 months be fed on diverse diets as a public health measure in curbing malnutrition. In Kenya, stunting rates among children below the age of five years is 26% and diversifying of diets is still sub-optimal.

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Development of a Novel Positive Pressure Protective Suit for a Biosafety Level 4 Laboratory in Japan.

Jpn J Infect Dis

March 2023

National Research Center for the Control and Prevention of Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Japan.

Biosafety level 4 (BSL-4) laboratories are necessary to study microorganisms that are highly pathogenic to humans and have no prevention or therapeutic measures. Currently, most BSL-4 facilities have suit-type laboratories to conduct experiments on highly pathogenic microorganisms. In 2021, the first Japanese suit-type BSL-4 laboratory was constructed at Nagasaki University.

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Effect of geranylated dihydrochalcone from Artocarpus altilis leaves extract on Plasmodium falciparum ultrastructural changes and mitochondrial malate: Quinone oxidoreductase.

Int J Parasitol Drugs Drug Resist

April 2023

Center of Natural Product Medicine Research and Development, Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia; Department of Pharmaceutical Sciences, Faculty of Pharmacy, Universitas Airlangga, Surabaya, Indonesia. Electronic address:

Article Synopsis
  • * Extracts from the leaves of the Artocarpus altilis plant show promising antimalarial activity, and researchers have identified a specific compound, 2-geranyl-2',4',3,4-tetrahydroxy-dihydrochalcone, as the active ingredient responsible for this effect.
  • * This compound disrupts the parasite's development inside red blood cells and inhibits certain enzymes in the mitochondria, suggesting it operates through a dual mechanism targeting the food vacuole and mitochondrial pathways.
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Long-term trends in mortality risk associated with short-term exposure to air pollution in 10 Japanese cities between 1977 and 2015.

Environ Res

February 2023

Department of Global Health, School of Tropical Medicine and Global Health, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan; Department of Global Health Policy, School of International Health, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.

Background And Aim: Short-term associations between air pollution and mortality have been well reported in Japan, but the historical changes in mortality risk remain unknown. We examined temporal changes in the mortality risks associated with short-term exposure to four criteria air pollutants in selected Japanese cities.

Methods: We collected daily mortality data for non-accidental causes (n = 5,748,206), cardiovascular (n = 1,938,743) and respiratory diseases (n = 777,266), and air pollutants (sulfur dioxide [SO], nitrogen dioxide [NO], suspended particulate matter [SPM], and oxidants [Ox]) in 10 cities from 1977 to 2015.

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Centrin-deficient Leishmania mexicana confers protection against Old World visceral leishmaniasis.

NPJ Vaccines

December 2022

Divsion of Emerging and Transfusion Transmitted Diseases, CBER, FDA, Silver Spring, MD, USA.

Leishmaniasis is one of the top neglected tropical diseases with significant morbidity and mortality in low and middle-income countries (LMIC). However, this disease is also spreading in the developed world. Currently, there is a lack of effective strategies to control this disease.

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Background: Despite the development of several methods for diagnosing COVID-19, long-term validation of such methods remains limited. In the early phase of the COVID-19 pandemic, we developed a rapid and sensitive diagnostic method based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) methodology, which is suitable for point-of-care application or for use in resource-limited settings to detect SARS-CoV-2. To assess the applicability of the RT-LAMP assay technique to resource-limited regions, such as rural areas in Africa, and to verify the usability of the method against various SARS-CoV-2 variants, the method was validated using clinical samples collected longitudinally during the pandemic.

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Data on the combined effect of atovaquone, mefloquine, and 3-bromopyruvic acid against protoscoleces.

Data Brief

December 2022

Laboratory of Parasitology, Department of Disease Control, Graduate School of Infectious Diseases, Faculty of Veterinary Medicine, Hokkaido University, N18 W9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan.

Article Synopsis
  • * Both aerobic and anaerobic tests revealed that mefloquine, alone or with atovaquone, quickly eliminated protoscoleces, but the combination with 3-bromopyruvic acid only showed synergy under anaerobic conditions.
  • * The findings suggest that these drug combinations could effectively target respiration pathways in vivo, potentially aiding the development of improved treatment methods for alveolar echinococcosis.
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Development of an imaging system for visualization of Ebola virus glycoprotein throughout the viral lifecycle.

Front Microbiol

November 2022

Department of Virus Infection Dynamics, National Research Center for the Control and Prevention of Infectious Diseases, Nagasaki University, Nagasaki, Japan.

Ebola virus (EBOV) causes severe EBOV disease (EVD) in humans and non-human primates. Currently, limited countermeasures are available, and the virus must be studied in biosafety level-4 (BSL-4) laboratories. EBOV glycoprotein (GP) is a single transmembrane protein responsible for entry into host cells and is the target of multiple approved drugs.

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Background: Voice messages have been employed as an effective and efficient approach for increasing health service utilization and health promotion in low- and middle-income countries. However, unlike SMS, voice message services require their users to pick up a phone call at its delivery time. Furthermore, voice messages are difficult for the users to review their contents afterward.

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Identification of novel orthonairoviruses from rodents and shrews in Gabon, Central Africa.

J Gen Virol

October 2022

Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki 852-8523, Japan.

Article Synopsis
  • Emerging zoonotic viruses in Africa are transmitted from small mammals like rodents and shrews to humans, with concerns about unrecognized diseases in Central Africa.
  • Researchers in Gabon identified new orthonairoviruses in 24.6% of small mammals, specifically two novel viruses: Lamusara virus (LMSV) and Lamgora virus.
  • The study indicates that LMSV could potentially pose health risks to humans due to its ability to suppress critical immune responses in human cells.
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Re-emergence of dengue, chikungunya, and Zika viruses in 2021 after a 10-year gap in Gabon.

IJID Reg

December 2022

Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.

Mosquito-borne viral infections are a major concern in endemic areas, such as Africa. Although outbreaks have been reported throughout Africa, only a few surveillance studies have been conducted in Gabon since the outbreaks of dengue virus (DENV) and chikungunya virus (CHIKV) in 2010. Therefore, the current situation is unknown.

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Infection of C57BL/6 wild-type mice with Leishmania major 5-ASKH or Friedlin strains results in relatively similar pathogenicity with self-healing lesions within weeks. Parasite clearance depends on nitric oxide production by activated macrophages in response to cytokines produced mainly by CD4 Th1 cells. In contrast, C57BL/6 Rag2 knockout mice, which lack T and B lymphocytes, show distinct pathologies during infection with these strains.

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Facile preparation of FeO@Pt nanoparticles as peroxidase mimics for sensitive glucose detection by a paper-based colorimetric assay.

R Soc Open Sci

September 2022

Department of Health Inspection and Quarantine, School of Public Health, Fujian Medical University, Fuzhou, Fujian, People's Republic of China.

A simple strategy to rapidly detect glucose was developed by utilizing core (FeO)-shell (Pt) magnetic nanoparticles (FeO@Pt NPs) as a nanoenzyme and a paper-based colorimetric sensor. In the presence of HO, FeO@Pt NPs catalyze the redox reaction of 3,3',5,5'-tetramethylbenzidine (TMB) and generate a colour change from colourless to blue. On this basis, a colorimetric glucose sensing method assisted by glucose oxidase (GOx) was developed.

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Dyke-davidoff-masson syndrome: A case report of an adolescent boy at a tertiary hospital in Adamawa, North-Eastern Nigeria.

Niger J Clin Pract

September 2022

Program for Nurturing Global leaders in Tropical and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University; Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.

Dyke-Davidoff-Masson Syndrome (DDMS) is a rare clinical condition in which atrophy or hypoplasia of one cerebral hemisphere occurs secondary to brain insult during fetal or early childhood, which results in variable clinical manifestations like hemiparesis, seizures, expressive aphasia, and mental retardation. This rare entity mainly presents in childhood and is unusual in adults. DDMS is a rare cause of epilepsy and should be considered and excluded in cases of refractory seizures.

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gametocytes have unique morphology, metabolism, and protein expression profiles in their asexual stages of development. In addition to the striking changes in their appearance, a wide variety of "exo-membrane structures" are newly formed in the gametocyte stage. Little is known about their function, localization, or three-dimensional structural information, and only some structural data, typically two-dimensional, have been reported using conventional electron microscopy or fluorescence microscopy.

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SICA-mediated cytoadhesion of Plasmodium knowlesi-infected red blood cells to human umbilical vein endothelial cells.

Sci Rep

September 2022

Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.

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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Potential application of the haematology analyser XN-31 prototype for field malaria surveillance in Kenya.

Malar J

September 2022

Department of Virology and Parasitology/Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.

Background: Simple and accurate diagnosis is a key component of malaria control programmes. Microscopy is the current gold standard, however it requires extensive training and the results largely rely on the skill of the microscopists. Malaria rapid diagnostic tests (RDT) can be performed with minimal training and offer timely diagnosis, but results are not quantitative.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S protein) is highly N-glycosylated, and a "glycan shield" is formed to limit the access of other molecules; however, a small open area coincides with the interface to the host's receptor and also neutralising antibodies. Most of the variants of concern have mutations in this area, which could reduce the efficacy of existing antibodies. In contrast, N-glycosylation sites are relatively invariant, and some are essential for infection.

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Schistosoma mansoni larvae in vitro cultures using Biomphalaria glabrata extracts.

Acta Trop

November 2022

Department of Pathogen, Infection and Immunity, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan.

Article Synopsis
  • The study tracked the location of S. mansoni larvae within Biomphalaria glabrata snails after infection, noting they initially reside in the head-foot area before moving to the hepatopancreas and ovotestis at later stages.
  • Using extracts from different snail organs for lab culturing revealed that the head-foot extract supports extended larval growth, while combined use with the hepatopancreas extract enhances the larvae's development into sporocysts.
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Pleiotropic Roles of Cholesteryl Sulfate during Encystation: Involvement in Cell Rounding and Development of Membrane Impermeability.

mSphere

August 2022

Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga Universitygrid.412339.e, Saga, Japan.

Entamoeba histolytica, a protozoan parasite, causes amoebiasis, which is a global public health problem. The major route of infection is oral ingestion of cysts, the only form that is able to transmit to a new host. Cysts are produced by cell differentiation from proliferative trophozoites in a process termed "encystation.

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This study aimed to investigate the epidemiological features of reported tuberculosis (TB) infections in a western prefecture (Nagasaki Prefecture) from 2007 to 2018, and to identify the high-risk group for TB infection. The characteristics of 12 years of reported TB infections from the Nagasaki Prefectural Informational Center of Infectious Diseases were summarized by median (interquartile range [IQR]) and proportion; the annual TB infections' notification rate regarding sex/age was calculated accordingly. The diagnosis of TB infection was made according to clinic symptoms and laboratory examination.

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Siccanin Is a Dual-Target Inhibitor of Mitochondrial Complex II and Complex III.

Pharmaceuticals (Basel)

July 2022

Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.

contains several mitochondrial electron transport chain (ETC) dehydrogenases shuttling electrons from the respective substrates to the ubiquinone pool, from which electrons are consecutively transferred to complex III, complex IV, and finally to the molecular oxygen. The antimalarial drug atovaquone inhibits complex III and validates this parasite's ETC as an attractive target for chemotherapy. Among the ETC dehydrogenases from , dihydroorotate dehydrogenase, an essential enzyme used in de novo pyrimidine biosynthesis, and complex III are the two enzymes that have been characterized and validated as drug targets in the blood-stage parasite, while complex II has been shown to be essential for parasite survival in the mosquito stage; therefore, these enzymes and complex II are considered candidate drug targets for blocking parasite transmission.

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Galactose and -acetyl-D-galactosamine-inhibitable lectin of have roles in the pathogenicity of intestinal amoebiasis. Igl1, the intermediate subunit lectin-1 of , has been shown to have both hemolytic and cytotoxic activities that reside in the C-terminus of the protein. To identify the amino acid regions responsible for these activities, recombinant proteins were prepared and used in hemolytic and cytotoxic assays.

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