Ken Katakura
Gunma University
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Featured researches published by Ken Katakura.
Parasitology | 2004
G. E. Luyo-Acero; Hiroshi Uezato; Minoru Oshiro; Kimiko Takei; Ken-ichi Kariya; Ken Katakura; E. Gomez-Landires; Y. Hashiguchi; Shigeo Nonaka
The Cytochrome b (Cyt b) gene has proved to be useful for identification and classification of many mammals and plants. In order to evaluate the utility of this gene for discrimination of Leishmania parasites as well as for exploring their phylogenetic relationships, we determined the nucleotide sequences of the Cyt b gene from 13 human-infecting Leishmania species (14 strains) from the New and Old Worlds. The Cyt b genes, approximately 1080 base pairs, were found to be A/T rich, and their 5 terminal-editing regions were highly conserved. The nucleotide sequence variation among them was enough to discriminate parasite species; 245 nucleotide positions were polymorphic and 190 positions were parsimony informative. The phylogenetic relationships based on this gene, showed good agreement with the classification of Lainson & Shaw (1987) except for the inclusion of L. (L.) major in the L. (L.) tropica complex and the placement of L. tarentolae in another genus. These data show that the Cyt b gene is useful for phylogenetic study of Leishmania parasites.
Acta Tropica | 2002
Tatsuyuki Mimori; T. Matsumoto; Manuel Calvopiña; Eduardo A. Gomez; H. Saya; Ken Katakura; Shigeo Nonaka; S. M. Shamsuzzaman; Yoshihisa Hashiguchi
In this study, we tested the polymerase chain reaction (PCR)-method to diagnose cutaneous leishmaniasis (CL) by taking exudate materials from lesions with cotton swabs, using our previously tested (PCR) panel comprised of Leishmania (Viannia) panamensis, L. (V.) braziliensis, L. (V.) guyanensis, L. (Leishmania) mexicana and L. (L.) amazonensis. The objectives of the present study were to improve the sampling method convenient for the patients and to test the usefulness of samples taken with cotton swabs. Sixteen patients were clinically diagnosed to have CL including one case of diffuse cutaneous leishmaniasis (DCL) in Ecuador and the causative Leishmania parasites were identified by PCR. All the 12 samples from CL patients of La Mana, positive for Leishmania DNA, were identified as L. (V.) panamensis, while two from CL of Huigra and one from DCL of San Ignacio were L. (L.) mexicana. In the field condition, taking biopsy material is not only painful but sometimes causes iatrogenic bacterial infections. Considering the sensitivity of the test, and convenient sampling procedure, it may be suggested that collection of exudates using cotton swabs may be a better alternative to biopsy sample for PCR-diagnosis of CL.
FEBS Letters | 2002
Qinghua Lin; Ken Katakura; Mamoru Suzuki
We previously reported the superior effect of minocycline against drug‐resistant Plasmodium falciparum in vitro. Here, we report that RT‐PCR for falciparum parasites treated with minocycline revealed reduced levels of RNA transcripts of the mitochondrion‐encoded genes such as the COI and Cyb genes, as well as the plastid‐encoded RNA polymerase subunit (rpoB/C) gene. However, we detected no apparent effects of the antibiotic on the transcription of merozoite surface antigen and small subunit rRNA genes encoded by the nucleus. In addition, treatment with chloroquine and pyrimethamine showed no substantial reduction of any RT‐PCR products. These findings suggest that tetracycline antibiotics selectively inhibit both mitochondrial and plastid activity.
FEBS Letters | 2004
Ken Katakura; Hiroshi Fujise; Keiichi Takeda; Osamu Kaneko; Motomi Torii; Mamoru Suzuki; Kwang Poo Chang; Yoshihisa Hashiguchi
The ATP‐binding cassette (ABC) proteins play an important role in drug resistance and detoxification in various organisms. Here we isolated LaMDR2, a new member of the multidrug resistance (MDR) subfamily of ABC proteins in Leishmania amazonensis. LaMDR2 exhibited 47% amino acid identity to its most closely related protein, LaMDR1, which was previously isolated from the same species. Promastigotes that overexpressed LaMDR2 showed significant resistance to 5‐fluorouracil (5‐FU), but not to LaMDR1 substrates. Expression of LaMDR2 in the transfectants was relatively higher in the log phase than the stationary phase, and a lower accumulation of [3H]5‐FU was observed in the log‐phase cells. These results suggest that LaMDR2 is involved in extrusion of xenobiotics, but functionally different from LaMDR1.
Journal of Dermatology | 2001
Hiroshi Uezato; Kimiko Takei; Motoyoshi Maruno; Noor Mohammad Khaskhely; Shigeo Nonaka; Minoru Oshiro; Ken-ichi Kariya; Ken Katakura; Tatsuyuki Mimori; A L Eduardo Gomez; Masato Furuya; S. M. Shamsuzzaman; Yoshihisa Hashiguchi
In this study, an attempt was made to identify different Leishmania species by polymerase chain reaction (PCR). Fourteen Leishmania strains from stock were tested by PCR and Southern blotting. A pair of primers were employed that anneal to the kinetoplast DNA sequence conserved among subgenus Leishmania. Of the 14 Leishmania strains used in this study, six showed strong bands of approximately 170 bp, and all the positive strains belonged to the species of the subgenus Leishmania viz., Leishmania (Leishmania) garnhami, L. (L.) amazonensis, L. (L.) pifanoi, L. (L.) mexicana, L. (L.) chagasi, and L. (L.) major. All the species belonging to the subgenus Viannia used in this study were negative by PCR. These results suggest that the primer pair may be useful for identification of the species belonging to the subgenus Leishmania of the New World as well as to distinguish subgenus Leishmania from subgenus Viannia.
Journal of Clinical Microbiology | 1998
Ken Katakura; Shin-ichiro Kawazu; Toshimitsu Naya; Koichi Nagakura; Mamoru Ito; Masamichi Aikawa; Jing-Qi Qu; Li-Ren Guan; Xin-Pin Zuo; Jun-Jie Chai; Kwang Poo Chang; Yoshitsugu Matsumoto
Journal of Veterinary Medical Science | 2005
Tri Murnigsih; Subeki; Hideyuki Matsuura; Kosaku Takahashi; Masahiro Yamasaki; Osamu Yamato; Yoshimitsu Maede; Ken Katakura; Mamoru Suzuki; Sumiko Kobayashi; Chairul; Teruhiko Yoshihara
Biochemical and Biophysical Research Communications | 1999
Ken Katakura; Masaki Iwanami; Hiroshi Ohtomo; Hiroshi Fujise; Yoshihisa Hashiguchi
American Journal of Tropical Medicine and Hygiene | 2004
Munehiro Sugiyama; Eiji Ikeda; Satoru Kawai; Tetsuya Higuchi; Hong Zhang; Nasim Khan; Katsumi Tomiyoshi; Tomio Inoue; Haruyasu Yamaguchi; Ken Katakura; Keigo Endo; Mamoru Suzuki
American Journal of Tropical Medicine and Hygiene | 2006
Satoru Kawai; Eiji Ikeda; Munehiro Sugiyama; Jun Matsumoto; Tetsuya Higuchi; Hong Zhang; Nasim Khan; Katsumi Tomiyoshi; Tomio Inoue; Haruyasu Yamaguchi; Ken Katakura; Keigo Endo; Hajime Matsuda; Mamoru Suzuki