Masaru Okuda

The First Identification and Retrospective Study of Severe Fever With Thrombocytopenia Syndrome in Japan

Abstract Background. Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan. Methods. Virologic and pathologic examinations were performed on the patients samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS. Results. A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis. Conclusions. SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.

Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs

Partial sequences of the 18S rRNA gene (625 bp) from a Hepatozoon detected in two canine hepatozoonosis cases, one clinical and one subclinical, in Japan were analyzed. Both sequences were identical to each other and they were closely related to the Hepatozoon canis strain found in Israel with 99% (617/625) nucleotide identity. Both Hepatozoon americanum and Hepatozoon catasbianae were distantly related to the Japanese Hepatozoon with 94% (586/625) and 91% (566/625) identities, respectively. In a phylogenetic tree, the Japanese Hepatozoon was most closely related to H. canis from Israel but was significantly different than H. americanum and H. catasbianae. These results suggest that the Hepatozoon detected in the Japanese dogs might be a strain variant of H. canis, but is apparently a different species than H. americanum.

Detection of Babesia canis rossi, B. canis vogeli, and Hepatozoon canis in dogs in a village of eastern Sudan by using a screening PCR and sequencing methodologies.

ABSTRACT Babesia and Hepatozoon infections of dogs in a village of eastern Sudan were analyzed by using a single PCR and sequencing. Among 78 dogs, 5 were infected with Babesia canis rossi and 2 others were infected with B. canis vogeli. Thirty-three dogs were positive for Hepatozoon. Hepatozoon canis was detected by sequence analysis.

Centrosome Hyperamplification Predicts Progression and Tumor Recurrence in Bladder Cancer

Purpose: Recent studies have reported that centrosome hyperamplification (CH) is closely related to chromosomal instability in bladder cancer. In this study, we investigated whether CH could be used as a prognostic biomarker for patients with bladder cancer. Experimental Design: CH was evaluated by immunohistochemistry in 50 bladder cancers (≤pT1: 43; ≥pT2: 7). In addition, numerical aberrations of chromosomes 7, 9, and 17 and gain of 20q13, on which the Aurora-A gene is located, were evaluated by fluorescence in situ hybridization, and DNA ploidy was assessed. Preliminary experiments on eight bladder cancer cell lines found that six had over 5% of CH cells associated with a gain of 20q13 and overexpression of Aurora-A; therefore, CH-positive cases (CH+) were defined as those having over 5% of cells with ≥3 centrosomes per cell. Results: CH+, 20q13 gain, chromosomal instability, and DNA aneuploidy were detected in 30 (60%), 18 (36%), 22 (44%), and 19 (38%) patients, respectively. There were significant differences in tumor number, grade, recurrence, and progression between the CH+ and CH− groups. The later had significantly higher recurrence-free and progression-free survivals than the former (P = 0.0028 and P = 0.0070, respectively, log-rank test). Multivariate analysis revealed that CH+ was the strongest predictor for tumor recurrence in nonmuscle invasive (pTa and pT1) bladder cancer (hazard ratio, 1.882; 95% confidence interval, 1.161–3.325; P = 0.0094). Conclusions: Detection of CH may provide crucial prognostic information about tumor recurrence in bladder cancer.

Ixodid tick species recovered from domestic dogs in Japan

The species of ixodid ticks (Acari: Ixodidae) recovered from domestic dogs in Japan between September to November 2000 and April to June 2001 were identified. A total of 4122 ticks, including 1624 larvae, 1200 nymphs, 1016 females and 282 males were removed from 1221 dogs during these periods. Haemaphysalis longicornis (Neumann) was the most frequently found (40.3% of dogs), followed by H. flava (Neumann) (16.1% of dogs), Rhipicephalus sanguineus (Latreille) (4.8% of dogs) and Ixodes ovatus (Neumann) (4.1% of dogs). Small numbers of H. hystricis (Supino), H. campanulata (Warburton), H. japonica (Warburton), H. ias (Nakamura and Yajima), I. persulcatus (Schulze), I. nipponensis (Kitaoka and Saito) and Amblyomma testudinarium (Koch) were also recovered. In the spring sample, a total of 1408 ticks (78 larvae, 411 nymphs, 792 adult females and 127 adult males) were recovered from 570 dogs. The autumn sample included a larger proportion of larval stage and fewer adult ticks (1546 larvae, 789 nymphs, 224 adult females and 155 adult males). Haemaphysalis longicornis, H. flava and I. ovatus showed a wide geographical distribution from northern to southern Japan, whereas R. sanguineus were mainly distributed in the subtropical Okinawa prefecture with a few exceptions. Dogs in rural areas more frequently carried H. longicornis, H. flava and I. ovatus than dogs in urban or suburban areas, whereas R. sanguineus was more associated with the dogs in urban/suburban areas. Exposure to a garden was significantly associated with R. sanguineus and exposure to woodland was significantly associated with H. flava and I. ovatus. This is the first systematic survey of canine ticks in Japan.

Epidemiological Survey of Babesia Species in Japan Performed with Specimens from Ticks Collected from Dogs and Detection of New Babesia DNA Closely Related to Babesia odocoilei and Babesia divergens DNA

ABSTRACT Detection and analysis of Babesia species from ticks recovered from dogs in Japan were attempted by PCR and nucleotide sequence analysis based on the 18S rRNA gene, respectively. A total of 1,136 ticks were examined for Babesia DNA by 18S rRNA-based PCR and nucleotide sequencing. Partial sequences of Babesia canis vogeli DNA were detected from six ticks in Aomori, Nara, Hiroshima, Oita, and Okinawa Prefectures; and Babesia gibsoni Asia-1 DNA was also detected in four ticks in Osaka, Hiroshima, Miyazaki, and Okinawa Prefectures. Unique sequences of 1,678 bp were also obtained from Ixodes ovatus ticks in Akita and Fukui Prefectures. The sequences were similar to those of Babesia odocoilei (97.7%) and Babesia divergens (97.6%). This is the first report of the detection of DNA belonging to this group in Japan.

Transcriptional Control of BubR1 by p53 and Suppression of Centrosome Amplification by BubR1

ABSTRACT Elimination of the regulatory mechanism underlying numeral homeostasis of centrosomes, as seen in cells lacking p53, results in abnormal amplification of centrosomes, which increases the frequency of chromosome segregation errors, and thus contributes to the chromosome instability frequently observed in cancer cells. We have previously reported that p53−/− mouse cells in prolonged culture undergo genomic convergence similar to that observed during tumor progression; early-passage p53−/− cells are karyotypically heterogeneous due to extensive chromosome instability associated with centrosome amplification, while late-passage p53−/− cells are aneuploid yet karyotypically homogeneous and chromosomally stable. Moreover, they contain numerically normal centrosomes. Through the microarray analysis of early- and late-passage p53−/− cells, we identified the BubR1 spindle checkpoint protein, which plays a critical role in suppression of centrosome amplification and stabilization of chromosomes in late-passage p53−/− cells. Up-regulation of BubR1 augments the checkpoint function, which effectively senses the spindle/chromosome aberrations associated with centrosome amplification. We further found that BubR1 transcription is largely controlled by p53. In early-passage p53−/− cells, BubR1 expression is low and the checkpoint function in response to microtubule toxin is considerably compromised. In late-passage cells, however, regaining of BubR1 expression restores the checkpoint function to mitotic aberrations caused by microtubule toxin. Our studies demonstrate the molecular aspect of genomic convergence in cultured cells, providing critical information for understanding the stepwise progression of tumors.

Epidemiological survey of Anaplasma platys and Ehrlichia canis using ticks collected from dogs in Japan

Detection of Anaplasma platys and Ehrlichia canis in ticks recovered from dogs in Japan was attempted using a species-specific nested PCR based on the 16S rRNA gene. A total of 1211 ticks recovered from 1211 dogs from all over Japan were examined for A. platys and E. canis. Four tick samples from Fukushima, Miyazaki and Kagoshima Prefectures recovered from four different dogs showed a positive reaction for A. platys. Although the four dogs did not show any clinical signs and no blood examination data were available, it is possible that A. platys has already been spread widely in Japan. No positive reactions were observed in any ticks examined for E. canis.

Determination of the nucleotide sequences of heat shock operon groESL and the citrate synthase gene (gltA) of Anaplasma (Ehrlichia) platys for phylogenetic and diagnostic studies.

ABSTRACT The 1,670-bp nucleotide sequence of the heat shock operon groESL and the 1,236-bp sequence of the citrate synthase gene (gltA) of Anaplasma (Ehrlichia) platys were determined. The topology of the groEL- and gltA-based phylogenetic tree was similar to that derived from 16S rRNA gene analyses with distances. Both groESL- and gltA-based PCRs specific to A. platys were also developed based upon the alignment data.

Demonstration of Anaplasma (Ehrlichia) platys inclusions in peripheral blood platelets of a dog in Japan.

A free-roaming dog in Okinawa island showed Anaplasma (Ehrlichia) platys-like inclusions within the platelets of peripheral blood samples. The inclusions were positive in indirect fluorescence test with anti-A. phagocytophila serum. The platelet count of the dog was 170,000 microl(-1). The sequence analysis of the 16S rRNA, citrate synthase and heat shock protein genes of DNA from the infected platelets confirmed that the inclusions were A. platys. This is the first detection of A. platys inclusions in dogs in Japan.