Hiroyuki Matsuoka

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Malaria, which is caused by Plasmodium parasites, is transmitted by anopheline mosquitoes. When gametocytes, the precursor cells of Plasmodium gametes, are transferred to a mosquito, they fertilize and proliferate, which render the mosquito infectious to the next vertebrate host. Although the fertilization of malaria parasites has been considered as a(More)
We conducted a survey for glucose-6-phosphate dehydrogenase (G6PD) deficiency using blood samples from male outpatients of a local hospital in southern Vietnam. Most of the samples were from the Kinh (88.9%), the largest ethnic group in Vietnam, with a small number (11.1%) coming from the K'Ho, Chauma, Nung, and Tay minorities. We detected 25 G6PD-deficient(More)
BACKGROUND In the context of the development of a successful malaria vaccine, understanding the polymorphisms exhibited by malaria antigens in natural parasite populations is crucial for proper vaccine design. Recent observations have indicated that sequence polymorphisms in the C-terminal T-cell epitopes of the Plasmodium falciparum circumsporozoite(More)
BACKGROUND Two current leading malaria blood-stage vaccine candidate antigens for Plasmodium falciparum, the C-terminal region of merozoite surface protein 1 (MSP1(19)) and apical membrane antigen 1 (AMA1), have been prioritized because of outstanding protective efficacies achieved in a rodent malaria Plasmodium yoelii model. However, P. falciparum vaccines(More)
BACKGROUND Chromobacterium violaceum is a Gram negative facultative anaerobic bacillus, found in soil and stagnant water, that usually has a violet pigmented appearance on agar culture. It is rarely described as a human pathogen, mostly from tropical and subtropical areas. CASE PRESENTATION A 53 year-old farmer died with Chromobacterium violaceum(More)
A novel bispecific single-chain antibody fragment (biscFv) has been constructed to address the possibility of a new approach to malaria therapeutic drug development. The biscFv consists of 2 different single-chain antibody fragments linked by a flexible peptide linker (Gly(4)-Ser)(3). Of the 2 scFv fragments, one is directed against a conserved epitope of(More)
Drug resistance compromises control of malaria. Here, we show that resistance to a commonly used antimalarial medication, atovaquone, is apparently unable to spread. Atovaquone pressure selects parasites with mutations in cytochrome b, a respiratory protein with low but essential activity in the mammalian blood phase of the parasite life cycle. Resistance(More)
We conducted a field survey of glucose-6-phosphate dehydrogenese (G6PD) deficiency in the eastern Indonesian islands, and analyzed G6PD variants molecularly. The incidence of G6PD deficiency in 5 ethnic groups (Manggarai, Bajawa, Nage-Keo, Larantuka, and Palue) on the Flores and Palue Islands was lower than that of another native group, Sikka, or a(More)
We produced a transgenic rodent malaria parasite (Plasmodium berghei) that contained the luciferase gene under a promoter region of elongation factor-1α. These transgenic (TG) parasites expressed luciferase in all stages of their life cycle, as previously reported. However, we were the first to succeed in observing sporozoites as a mass in mouse skin(More)
Plasmodium falciparum malaria imposes a serious public health concern throughout the tropics. Although genetic tools are principally important to fully investigate malaria parasites, currently available forward and reverse tools are fairly limited. It is expected that parasites with a high mutation rate can readily acquire novel phenotypes/traits; however,(More)