Publications by authors named "Masatsugu Kimura"

RBM10 is an RNA-binding protein that regulates alternative splicing (AS). It localizes to the extra-nucleolar nucleoplasm and S1-1 nuclear bodies (NBs) in the nucleus. We investigated the biological significance of this localization in relation to its molecular function.

View Article and Find Full Text PDF

Genetic polymorphisms contribute to inter-individual variability in the metabolism of multiple clinical drugs, including warfarin, thiopurines, primaquine, and aminoglycosides. A rapid and sensitive clinical assessment of various genome biomarkers is, therefore, required to predict the individual responsiveness of each patient to these drugs. In this study, we developed a novel genotyping method for the detection of nine pharmacogene variants that are important in the prediction of drug efficiency and toxicity.

View Article and Find Full Text PDF

Background: Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent.

Methods: The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp.

View Article and Find Full Text PDF

Malaria is caused by five species of Plasmodium in humans. Microscopy is currently used for pathogen detection, requiring considerable training and technical expertise as the parasites are often difficult to differentiate morphologically. Rapid diagnostic tests are as reliable as microscopy and offer faster diagnoses but possess lower detection limits and are incapable of distinguishing among the parasitic species.

View Article and Find Full Text PDF

Background: Plasmodium falciparum SURFIN is a putative ligand expressed on the merozoite and likely on the infected red blood cell, whose gene was suggested to be under directional selection in the eastern Kenyan population, but under balancing selection in the Thai population. To understand this difference, surf sequences of western Kenyan P. falciparum isolates were analysed.

View Article and Find Full Text PDF

Kenya is intensifying its national efforts in malaria control to achieve malaria elimination. Detailed characterization of malaria infection among populations living in the areas where the disease is endemic in Kenya is a crucial priority, especially for planning and evaluating future malaria elimination strategy. This study aimed to investigate the distribution and extent of malaria infection on islands in Lake Victoria of Kenya to aid in designing new interventions for malaria elimination.

View Article and Find Full Text PDF

The synthetic thymidine analogue, 5-bromo-2'-deoxy-uridine (BrdU) was encapsulated in cationic liposome composed of dipalmitoylphosphatidylcholine, cholesterol and stearylamine (molar ratio = 1/1/0.2; diameter = 120 nm), and the radiosensitization of cationic liposomal BrdU was assessed on human melanoma cells HMV-II, with comparing to anionic or nonionic liposomal BrdU and free-BrdU. HMV-II cells were pretreated by cationic liposomal BrdU or free-BrdU and then exposed to X-ray, followed by WST-8 assay to examine cell proliferation.

View Article and Find Full Text PDF

Detection of sub-microscopic parasitemia is crucial for all malaria elimination programs. PCR-based methods have proven to be sensitive, but two rounds of amplification (nested PCR) are often needed to detect the presence of Plasmodium DNA. To simplify the detection process, we designed a nested PCR method whereby only the primary PCR is required for the detection of the four major human Plasmodium species.

View Article and Find Full Text PDF

RBM10, originally called S1-1, is a nuclear RNA-binding protein with domains characteristic of RNA processing proteins. It has been reported that RBM10 constitutes spliceosome complexes and that RBM5, a close homologue of RBM10, regulates alternative splicing of apoptosis-related genes, Fas and cFLIP. In this study, we examined whether RBM10 has a regulatory function in splicing similar to RBM5, and determined that it indeed regulates alternative splicing of Fas and Bcl-x genes.

View Article and Find Full Text PDF

Resurgence is a major concern after malaria elimination. After the initiation of the elimination program on Aneityum Island in 1991, microscopy showed that Plasmodium falciparum disappeared immediately, whereas P. vivax disappeared from 1996 onward, until P.

View Article and Find Full Text PDF

Background Information: S1-1, also called RBM10, is an RNA-binding protein of 852 residues. An alteration of its activity causes TARP syndrome, a severe X-linked disorder with pre- or post-natal lethality in affected males. Its molecular function, although still largely unknown, has been suggested to be transcription and alternative splicing.

View Article and Find Full Text PDF

Wild isolates of malaria parasites were preserved in wet ice for 2-12 days and cultivated by a candle jar method. In four isolates of Plasmodium falciparum collected from Myanmar and preserved for 12 days, all failed to grow. In 31 isolates preserved for 5-10 days, nine were transformed to young gametocytes, but 22 isolates grew well.

View Article and Find Full Text PDF

The nitroimidazole-related hypoxic radiosensitizer, pimonidazole (Pmz) was encapsulated in liposome composed of dipalmitoylphosphatidylcholine, cholesterol and dipalmitoylphosphatidylglycerol (molar ratio = 1:1:0.2; diameter = 112.9 nm), and the radiosensitization was evaluated in human melanoma cells HMV-II.

View Article and Find Full Text PDF

In order to erase reactive oxygen species (ROS) related with the proliferation of tumor cells by reducing activity of hydrogen, we developed functional water containing nano-bubbles (diameters: <900 nm for 71%/population) hydrogen of 1.1-1.5 ppm (the theoretical maximum: 1.

View Article and Find Full Text PDF

Background Information: The RNA-binding protein S1-1, also called RBM10 (RNA-binding motif 10), is a paralogue of putative tumour suppressor RBM5 and has been correlated with cancer proliferation and apoptosis. In the present study, we have investigated the cell biology of S1-1.

Results: In the extranucleolar nucleoplasm, S1-1 occurred in hundreds of punctate and irregular domains.

View Article and Find Full Text PDF

Objective: To examine the effect of a low concentration of DHEAS on the expression of the androgen receptor, estrogen receptor alpha and beta, progesterone receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2 in human preovulatory granulosa cells, and to measure their production of steroid hormones (estrone, estradiol, progesterone, androstenedione, and testosterone).

Design: Analysis of cultured primary human preovulatory granulosa cells by real-time reverse-transcriptase polymerase chain reaction and assays of hormone production.

Setting: Osaka City University Postgraduate School of Medicine.

View Article and Find Full Text PDF

Complete DNA sequences of the small subunit ribosomal RNA (SSUrRNA) gene and partial sequences of three other loci were obtained from three variant-type and three classic-type Plasmodium ovale isolates from Southeast Asia and compared with GenBank-available data. Three different SSUrRNA sequences (Pov 1-3) were found in each variant-type isolate, and two different SSUrRNA sequences (Poc 1-2) in each classic-type isolate. Pov 1-3 were closer to sequences previously found in the Cameroon and MAL/MAI isolates, whereas Poc 1-2 were closer to sequences previously found in two clones of the Nigerian I/CDC strain.

View Article and Find Full Text PDF

The mechanisms producing the genetic polymorphism at Plasmodium falciparum merozoite surface antigen-1 locus (pfmsp1) include the insertion and deletion of the different type of dimorphic Block 2 9-nucleotide repeat units as well as the intragenic recombination. To study relative occurrence frequencies of these two distinct mechanisms, we have developed a sensitive PCR strategy to identify both 5' recombinant types and the number of Block 2 repeats from the same sample. This method can specifically detect the target 5' recombinant type (Blocks 2-6) at the sensitivity of 1-4 copies of the pfmsp1.

View Article and Find Full Text PDF

Molecular analysis of the alpha-N-acetylglucosaminidase gene in seven Japanese patients with Sanfilippo syndrome type B from six unrelated families was carried out, and six disease-causing mutations were found. The parents of Patient 2 had a consanguinous marriage, but other families did not have any record of consanguinity. Two families were from Okinawa Island, where more patients with Sanfilippo syndrome were found than in other areas in Japan.

View Article and Find Full Text PDF

We determined the nucleotide sequence of the fusion (F) gene of three strains (Osaka-1, -2, and -3) of nonproductive variants of measles virus (MV). These viral strains were isolated in Osaka, Japan, from brain tissues of patients with subacute sclerosing panencephalitis (SSPE). Phylogenetic analysis revealed a close relationship among the three strains of SSPE virus.

View Article and Find Full Text PDF

During malaria surveys in Myanmar, 2 peculiar forms of Plasmodium malariae-like parasites were found. The morphologies of their early trophozoite stages were distinct from that of the typical P. malariae, resembling instead that of Plasmodium vivax, var.

View Article and Find Full Text PDF