研究者業績

加藤 卓也

カトウ タクヤ  (Takuya Kato)

基本情報

所属
日本獣医生命科学大学 獣医学部 獣医学科 野生動物学研究室 准教授
学位
博士(獣医学)(2011年3月 日本獣医生命科学大学大学院)

J-GLOBAL ID
201501001433175568
researchmap会員ID
B000249758

論文

 43
  • Kandai Doi, Takuya Kato, Minori Kono, Fumiaki Yamasaki, Shin-ich Hayama
    Mammal Study 49(3) 2024年6月6日  査読有り
  • Ayaka Kitajima, Toshihiro Tokiwa, Kandai Doi, Kaito Kotani, Hiroko Otsubo, Chinatsu Kamei, Hiromitsu Hitani, Toshiaki Yamamoto, Takuya Kato
    Parasitology International 102913-102913 2024年6月  査読有り
  • Shin-Ichi Hayama, Setsuko Nakanishi, Aki Tanaka, Takuya Kato, Chinatsu Watanabe, Nobutaka Kikuchi, Risa Danjo, Ayano Matsuda, Wakako Mori, Yuki Kawabata, Hikari Akiba, Fumiharu Konno, Yoshi Kawamoto, Toshinori Omi
    Archives of environmental contamination and toxicology 2024年4月25日  査読有り
    We examined the conception rate of wild Japanese monkeys (Macaca fuscata) in Fukushima City that were exposed to radiation as a result of the Fukushima Daiichi Nuclear Power Plant accident in March 2011. The conception rate in the year of delivery from 2009 to 2022 was estimated by dissecting individuals that were euthanized by the government for population control as a countermeasure against crop damage. To evaluate the effects of exposure, the cumulative exposure dose for each individual was calculated using the concentration of radiocesium deposited in the soil at the capture site and the concentration of radiocesium in muscle estimated from the aggregated transfer factor. There were no significant differences in conception rates across all age classes over time. In terms of conception rates by age class, there was a significant decrease post-exposure compared with pre-exposure in the age class ≥ 8 years, but no significant differences in the age class 5-7 years. The non-ovulation rate did not significantly differ between the pre- and post-exposure periods for any age class. Body fat index, which can affect fertility, was compared between the pre- and post-exposure periods, and no significant differences were found in either age class. In contrast, the median total cumulative exposure (cumulative internal exposure + cumulative external exposure) was significantly higher in the age class ≥ 8 years compared with the age class 5-7 years. These results suggest that the total cumulative exposure dose may be one of the reasons for the lower conception rate in the post-exposure period among the age class ≥ 8 years.
  • Nana Ushine, Makoto Ozawa, Shouta M. M. Nakayama, Mayumi Ishizuka, Takuya Kato, Shin-ichi Hayama
    Animals 13(14) 2338-2338 2023年7月  査読有り
    Lead (Pb), an environmental pollutant, has been widely reported to have contaminated mammals, including humans and birds. This study focuses on the effects of Pb pollution on avian influenza virus (AIV) antibody production. A total of 170 black-headed gulls (Chroicocephalus ridibundus) were captured in Tokyo Bay (TBP) from January 2019 to April 2020 and in Mikawa Bay (MBP) from November 2019 to April 2021. The gulls were weighed, subjected to blood sampling, and released with a ring band on their tarsus. The samples were used to measure blood Pb levels (BLL) and AIV-specific antibodies. The BLL were compared using the Wilcoxon two-sample test between the period when black-headed gulls arrived and the wintering period, defined by the number of gulls counted in each area. A significant increase was found in the TBP. A decrease in BLL significantly increased antibody titer during wintering in TBP and MBP. Pb pollution had a negative effect on the production of AIV antibodies. These findings suggest that wild birds that were contaminated by Pb in the environment may facilitate the spread of zoonotic diseases, further increasing the possibility that environmental pollutants may threaten human health.
  • Nana Ushine, Shouta MM Nakayama, Mayumi Ishizuka, Takuya Kato, Shin-ichi Hayama
    Japanese Journal of Environmental Toxicology 26 25-37 2023年6月  査読有り
  • Yurika Tokunaga, Hiroshi Okochi, Yuto Tani, Yasuhiro Niida, Toshio Tachibana, Kazuo Saigawa, Kinya Katayama, Sachiko Moriguchi, Takuya Kato, Shin-ichi Hayama
    Chemosphere 321 138032-138032 2023年4月  査読有り
  • Kandai Doi, Toshihiro Tokiwa, Miyu Imoto, Shyun Chou, Fumiaki Yamasaki, Takuya Kato, Shin-ichi Hayama
    Parasites & Vectors 16(1) 2023年3月30日  査読有り
    Abstract Background The oriental eyeworm Thelazia callipaeda (Spirurida: Thelaziidae) is an emerging parasitic ocular nematode of carnivores and humans. In domestic animals and humans, the infection causes varying degrees of inflammation and lacrimation, and wild carnivores represent an important reservoir. In this study we examined the infection status and molecular characterization of T. callipaeda in two urban carnivores, raccoons Procyon lotor and wild Japanese raccoon dogs Nyctereutes viverrinus, in the Kanto region of Japan. Methods From January 2020 to December 2021, 193 carcasses including 178 raccoons and 15 raccoon dogs were examined for the presence of worms in the eye. The worms from infected animals (one worm per host) were morphologically identified as T. callipaeda. Worms (1–5 worms per host) were subjected to genetic analysis using mitochondrial cytochrome c oxidase subunit I gene sequences. Results The prevalence of T. callipaeda in raccoons and Japanese raccoon dogs was 20.2% (36/178) and 13.3% (2/15), respectively. The cox1 sequences from 56 worms from 38 animals revealed three haplotypes (h9, h10, and h12). Analysis of multiple worms for five raccoons showed co-infection of two different haplotypes (h9 and h10) in a single host. Comparing our data with published sequences, three sequences obtained from raccoons and raccoon dogs shared the same haplotypes as those reported in humans, dogs, and cats in Japan. Conclusions Our findings show a high prevalence of T. callipaeda in raccoons, suggesting that this invasive carnivore species serves as an important natural reservoir of T. callipaeda in the Kanto region of Japan, an area with the highest human population of the country. Graphical Abstract
  • Nana Ushine, Masaki Michishita, Yukino Machida, Tatsuya Enomoto, Takaaki Sakai, Takuya Kato, Shin-ichi Hayama
    Journal of Veterinary Medical Science 85(1) 88-91 2023年1月  査読有り
  • Kaito Kotani, Kandai Doi, Nana Ushine, Takuya Kato, Tatsuo Sato, Masaki Nonagase, Shin-ichi Hayama
    Medical Entomology and Zoology 73(4) 157-159 2022年12月25日  査読有り
  • Takuya Kato, Fumiaki Yamasaki, Kandai Doi, Mieko Kawamichi, Shin-ichi Hayama
    Animals 13(1) 55-55 2022年12月23日  査読有り筆頭著者責任著者
    Although the genetic distribution of introduced raccoons (Procyon lotor) in recent years is well known, few studies have examined their morphometrics, especially the relationships between sex and age in the introduced populations. The aim of this study was to describe the morphological characteristics of raccoons from parts of eastern and western Japan during their early invasion stages, focusing on the relationships between body length and the principal component of craniometrics, with region, sex, age class, body length, and body mass index using a regression model. The body length increased more in males than females and in the older age class, supporting the association with intrasexual selection and competition for food resources. Positive relationships for body length and body mass index were found in craniometric analyses, particularly regarding cranial size components, in addition to age class for both sexes, while cranial size also differed between regions for females. The relationship between body length and craniometrics was inconsistent with that of subspecies originating in North America. Given the sympatric distribution of haplotypes of multiple subspecies without reproductive-isolating barriers in North America and in several introduced areas, hybridization must have occurred prior to the introduction or naturalization of this species.
  • Kazuki Kiuno, Takuya Kato, Hiroko Otsubo, Ryoko Kibe, Yasushi Kataoka, Shin-ichi Hayama
    Animals 13(1) 21-21 2022年12月21日  査読有り責任著者
    Leptospirosis is a zoonosis that affects humans and animals worldwide. Raccoons (Procyon lotor), adopted in urban environments, may act as potential reservoirs of Leptospira. We investigated the prevalence of pathogenic Leptospira in the kidney and urine samples of raccoons living in Tokyo, as well as anti-leptospiral antibodies in their serum, and aimed to examine the factors that expose raccoons to Leptospira. Polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect leptospiral DNA and anti-leptospiral antibodies, respectively. Thirty-six of 156 raccoons (23.1%) were positive by PCR, and 16 of 165 raccoons (9.7%) were positive by ELISA. The prevalence and seroprevalence rates differed depending on the raccoon dispersal period. We used univariable logistic regression to estimate the environmental factors associated with pathogenic Leptospira and anti-leptospiral antibodies in raccoons. Significant differences were observed in the PCR results for the seasons (spring–summer) (p = 0.01), average monthly temperature (p < 0.01), and average monthly rainfall (p < 0.01). No significant difference was seen in the ELISA results, but raccoons in larger urban areas tended to have higher seroprevalence rates (p = 0.06). We identified a pattern of leptospiral spread in raccoon dispersal and environmental factors that expose raccoons to Leptospira.
  • Nana Ushine, Osamu Kurata, Yoshikazu Tanaka, Shouta M.M Nakayama, Mayumi Ishizuka, Takuya Kato, Shin-Ichi Hayama
    Avian Conservation and Ecology 17(2) 2022年11月  査読有り
  • Kandai Doi, Takuya Kato, Iori Tabata, Shin-Ichi Hayama
    Insects 12(12) 2021年12月7日  査読有り
    BACKGROUND: Tick distributions have changed rapidly with changes in human activity, land-use patterns, climate, and wildlife distributions over the last few decades. METHODS: To estimate potential distributions of ticks, we conducted a tick survey at 134 locations in western Kanto, Japan. We estimated the potential distributions of six tick species (Amblyomma testudinarium Koch, 1844; Haemaphysalis flava Neumann, 1897; Haemaphysalis kitaokai Hoogstraal, 1969; Haemaphysalis longicornis Neumann, 1901; Haemaphysalis megaspinosa Saito, 1969; and Ixodes ovatus Neumann, 1899) using MaxEnt modeling based on climate patterns, land-use patterns, and the distributions of five common wildlife species: sika deer (Cervus nippon Temminck, 1838), wild boar (Sus scrofa Linnaeus, 1758), raccoon (Procyon lotor Linnaeus, 1758), Japanese raccoon dog (Nyctereutes procyonoides Gray, 1834), and masked palm civet (Paguma larvata C.E.H. Smith, 1827)). RESULTS: We collected 24,546 individuals of four genera and 16 tick species. Our models indicated that forest connectivity contributed to the distributions of six tick species and that raccoon distribution contributed to five tick species. Other than that, sika deer distribution contributed to H. kitaokai, and wild boar distribution, bamboo forest, and warm winter climate contributed specifically to A. testudinarium. CONCLUSIONS: Based on these results, the dispersal of some tick species toward residential areas and expanded distributions can be explained by the distribution of raccoons and by forest connectivity.
  • Kandai Doi, Fumiaki Yamasaki, Takuya Kato, Shin-ichi Hayama
    Acta Arachnologica 70(1) 47-48 2021年6月28日  査読有り
    A pseudoscorpion was found in the underfur of a feral raccoon (Procyon lotor) captured in western Tokyo in December 2019. Based on the morphological features, we identified the specimen as Haplochernes sp. This arboreal pseudoscorpion rides other arthropods and small mammals for dispersion, but little is known that the species rides medium-sized mammals such as raccoons. To our knowledge, this is the first case report of Haplochernes sp. riding a feral raccoon. Given that raccoons are an invasive species in Japan, further records of pseudoscorpions riding feral raccoons may elucidate the relationship between feral raccoons and pseudoscorpions.
  • Kandai Doi, Minori Kono, Takuya Kato, Shin-Ichi Hayama
    Ticks and tick-borne diseases 12(3) 101687-101687 2021年5月  査読有り
    The raccoon (Procyon lotor) and masked palm civet (Paguma larvata) are introduced species in Japan and have become abundant in human-inhabited environments. We surveyed tick infestations and tick ingestion by introduced raccoons and masked palm civets captured in Hayama, Kanagawa Prefecture, Japan between November 2018 and January 2020. We collected ticks from the body surface of animals and tick capitula from the gastrointestinal contents. We collected 18,357 ticks identified as Haemaphysalis flava, Haemaphysalis megaspinosa, Haemaphysalis longicornis, Ixodes ovatus, Ixodes tanuki, and Amblyomma testudinarium from 58 of 60 raccoons and 152 ticks, identified as H. flava and I. tanuki, from 16 of 41 masked palm civets. Furthermore, we obtained 16 capitula from 12 % of raccoons and 106 capitula from 63 % of masked palm civets. Raccoons harbored a greater number of ticks (all stages of H. flava and adult I. tanuki) compared with masked palmed civets, whereas the latter species ingested a greater number of nymphal and larval ticks. The results of this study extend our understanding of the ecological roles of two introduced wildlife species. The raccoon may act as an ecological booster, thereby increasing the success rate of bloodmeals and reproduction in ticks. In contrast, the masked palm civet may act as an ecological trap by effectively grooming to remove ticks and prevent bloodmeals.
  • Sachiko Moriguchi, Rin Hosoda, Nana Ushine, Takuya Kato, Shin-Ichi Hayama
    Preventive veterinary medicine 187 105234-105234 2021年2月  査読有り
    Since the re-emergence of a highly pathogenic avian influenza (HPAI) in 2004, outbreaks of the viral subtypes HPAI, H5N1, H5N8, and H5N6 in wild birds, poultry, and zoo birds have occurred in Japan. In 2008, a nation-wide avian influenza (AI) surveillance program was started for the early detection of the HPAI virus (HPAIV) and for the assessment of HPAIV infection among wild birds. In this study, we aimed to conduct an overview of the AI surveillance system of wild birds in Japan, including those in the regions and prefectures, to assess its overall performance and develop insights on its improvement. We analyzed past surveillance data in Japan and conducted questionnaire surveys for the officers in 11 regional branches of the Ministry of Environment and the nature conservation divisions of 47 prefectures to acquire details regarding those AI surveillance. We found that the early detection of HPAIV in wild birds was successfully achieved in only one of the five outbreak seasons during the 2008-2019 period in Japan, and the assessment of HPAIV infection had possibly not been adequate in the national surveillance system. In the winter season, AI surveillance in most prefectures were mainly conducted by means of passive surveillance through reported dead birds and active surveillance through collected waterbird feces. Conversely, less than half of the prefectures conducted bird monitoring, patrolling in migratory bird habitats, and AI antigen testing in rescued birds. In areas surrounding HPAI occurrence sites (<10 km), bird monitoring and patrolling efforts were enhanced. However, AI testing efforts in waterbird feces and rescued birds were decreased. The AI surveillance for endangered bird species and in national wildlife protection areas was conducted by the branches of the Ministry of Environment and by the prefectures. Based on our results, we concluded that for maximum efficiency, legislation which specialized in wildlife pathogens should be necessary to prepare adequate national budget and testing capacity for appropriate surveillance system with periodical assessment for surveillance results and the system.
  • Natsuko Sugiura, Aki Tanaka, Kazuhiko Ochiai, Toshiaki Yamamoto, Tatsushi Morita, Takuya Kato, Yoshi Kawamoto, Toshinori Omi, Shin-Ichi Hayama
    The Journal of veterinary medical science 82(9) 1306-1311 2020年9月24日  査読有り
    Although kinship (parent-offspring or siblings) contact has been suggested as a driving factor for sarcoptic mange epizootic in raccoon dogs (Nyctereutes procyonoides), no effect has been reported. In contrast, habitat fragmentation caused by urbanization may result in a high occurrence of sarcoptic mange, because habitat fragmentation may promote contact infection by increasing the population density of raccoon dogs. The habitat distribution of raccoon dogs may therefore influence epizootic sarcoptic mange. The genetic relationship between raccoon dogs was analyzed to examine Sarcoptes scabiei transmission between kin. The relationship between S. scabiei infection and the habitat of raccoon dogs was also investigated. Seventy-five raccoon dogs from Takasaki, Gunma prefecture, were examined from 2012 to 2018; 23 were infested with S. scabiei. The genotypes were determined using 17 microsatellite loci, and the relationships were categorized into four patterns by the ML-Relate software. There was no significant difference between infested pairs and other two pairs (Chi- squared test: χ2=0.034, df=1, P=0.85). Although it was difficult to predicate because the mortality rate was unclear in this study, kinship contact does not seem to be an important factor for sarcoptic mange epizootic. S. scabiei infection rates were significantly associated with the location of village sections (OR=1.55, 95% CI=1.11-2.17, P=0.011). It is suggested that direct/indirect contact between individuals living closely together is an important factor for the transmission of S. scabiei.
  • Natsuko Sugiura, Kazuhiko Ochiai, Toshiaki Yamamoto, Takuya Kato, Yoshi Kawamoto, Toshinori Omi, Shin-Ichi Hayama
    The Journal of veterinary medical science 82(4) 479-482 2020年4月9日  査読有り
    We analyzed the genotypes of three pregnant females and their litters to investigate the phenomenon of multiple paternity in wild raccoon dogs (Nyctereutes procyonoides) using 17 microsatellite markers. If a female has mated with only one male during estrus, then the maximum number of paternal alleles will not exceed two among littermates with the same father. The results revealed two out of three litters had three or four paternal alleles at one or five microsatellite loci. Therefore, the female had mated with more than one male during estrus. To the best of our knowledge, the present study is the first to report the possibility of multiple paternity in wild raccoon dogs.
  • Kandai Doi, Katsunori Nishida, Takuya Kato, Shin-Ichi Hayama
    International journal for parasitology. Parasites and wildlife 11 302-307 2020年4月  査読有り
    The effects of introduced mammal species on the ecology of parasites are often under investigated. The sika deeer, Cervus nippon, is host species of many hard ticks. We collected 8348 ticks on an island where sika deer were introduced. The most representative species was Haemaphysalis megaspinosa (n = 4198; 50.3%), followed by H. longicornis (n = 1945; 23.3%), H. cornigera (n = 1179; 14.1%), H. flava (n = 713; 8.5%), Ixodes turdus (n = 289; 3.7%), I. granulatus (n = 22; 0.3%), and H. hystricis (n = 2; <0.1%) on an island where sika deer were introduced. H. megaspinosa and H. hystricis have not previously been recorded on the Izu islands. The high abundance of H. megaspinosa indicated that the tick species may have been introduced with the sika deer. Furthermore, H. megaspinosa larvae were more abundant at collection sites 21-40 days after sika deer were caught by foot snare traps indicate that engorged female of this tick species were forced to drop off in a very limited area near the foot snare trap. This represented a risk for hunters and people associated with wildlife control visiting the area.
  • Toshinori Omi, Sachie Nakiri, Setsuko Nakanishi, Naomi Ishii, Taiki Uno, Fumiharu Konno, Takeshi Inagaki, Atsushi Sakamoto, Masayuki Shito, Chihiro Udagawa, Naomi Tada, Kazuhiko Ochiai, Takuya Kato, Yoshi Kawamoto, Shuichi Tsuchida, Shin-Ichi Hayama
    BMC research notes 13(1) 121-121 2020年3月2日  査読有り
    OBJECTIVES: Following the massive earthquake that struck eastern Japan on March 11, 2011, a large amount of radioactive material was released into the environment from the damaged reactor of the Fukushima Daiichi Nuclear Power Plant (FDNPP). After the FDNPP accident, radiocaesium was first detected in muscle samples from wild Japanese monkeys exposed to radioactive materials, and haematologic effects, changes in head size, and delayed body weight gain were also reported, but little is known about the distribution of 137Cs in the organs and tissues of wild Japanese monkeys. RESULTS: We detected the 137Cs in various organ and tissue samples of 10 wild Japanese monkeys inhabiting the forested areas of Fukushima City that were captured between July and August 2012. Among muscle, brain, heart, kidney, liver, lung, and spleen, muscle exhibited the highest and the brain the lowest 137Cs concentration. The concentration (mean ± SD) of 137Cs in muscle, brain, heart, kidney, liver, lung, and spleen was 77 ± 66, 26 ± 22, 41 ± 35, 49 ± 41, 41 ± 38, 53 ± 41, and 53 ± 51 Bq/kg, respectively. These results can help us understand the biological effects of long-term internal radiation exposure in non-human primates.
  • Matsuyama R, Yabusaki T, Senjyu N, Okano T, Baba M, Tsuji-Matsukane T, Yokoyama M, Kido N, Kadosaka T, Kato T, Suzuki M, Asano M
    Parasites & vectors 12(1) 389-389 2019年8月  査読有り
  • Yukino Machida, Masaki Michishita, Hisashi Yoshimura, Takuya Kato, Shin-Ichi Hayama, Kimimasa Takahashi
    The Journal of veterinary medical science 81(7) 975-979 2019年7月11日  査読有り
    A 21-year-old male masked palm civet died after 2 months of continuous abdominal distention and poor appetite. Grossly, both musk glands were markedly swelled. Microscopically, round, polygonal and spindle neoplastic cells proliferated diffusely in the right musk gland and a metastatic focus was observed in the lung. The neoplastic cells had abundant cytoplasm with faintly eosinophilic inclusions that ultrastructurally corresponded to whorl aggregates of intermediate filaments. Immunohistochemically, these cells were positive for vimentin, cytokeratins and glial fibrillary acidic protein and negative for desmin. Based on these findings, the tumor was diagnosed as malignant rhabdoid tumor. Papillary adenoma was seen in the opposite musk gland. T-cell lymphoma of the lymph nodes, small intestine and liver was considered as the cause of death.
  • Kandai Doi, Takuya Kato, Shin-Ichi Hayama
    International journal for parasitology. Parasites and wildlife 7(3) 355-359 2018年12月  査読有り
    Since the raccoon (Procyon lotor) was introduced to Japan, studies have established that they are infested with native Japanese tick species. However, the quantity of ticks infesting raccoons is unknown. We conducted a survey of ticks on invasive raccoons captured on the Miura Peninsula, Kanagawa Prefecture, Japan, from April 2015 through June 2016 to determine the species of ticks and to quantify the intensity of tick infestation in order to obtain basal information related to the ecology of host-parasite relationships among indigenous tick species and an alien mammalian species. We collected and identified 15,931 ticks of two genera and six species, namely, Haemaphysalis flava, H. megaspinosa, H. longicornis, H. japonica, Ixodes ovatus, and I. tanuki, from 100 out of 115 raccoons. The dominant tick species was H. flava (96.8%) and individuals were mainly adults. Seasonal patterns of infestation intensity of adults and nymphs peaked in the autumn and winter and decreasing in the late spring and summer, May to August, while larvae peaked in August. Our results indicated that host-parasite relationships between invasive raccoons and Japanese tick species, especially H. flava, were established in Kanagawa Prefecture. The ticks infest invasive raccoons for their blood-meal and also for overwintering. The results of this study extend our understanding of the ecology of tick-borne diseases.
  • Natsuko Sugiura, Kandai Doi, Takuya Kato, Tatsushi Morita, Shin-ichi Hayama
    Journal of Veterinary Medical Science 80(3) 544-548 2018年3月  査読有り
  • Naomi Ishii, Takuya Kato, Taiki Uno, Ichirou Tanaka, Hiroshi Kajigaya, Shin-ichi Hayama
    International Journal of Primatology 38(6) 1090-1101 2017年12月  査読有り
    During grooming, primates remove harmful ectoparasites, such as ticks and lice, and there is direct evidence for a health benefit of tick removal. Grooming behaviors differ among primates with respect to age and sex. Moreover, the number of ectoparasite may exhibit seasonal variation. Therefore the number of ectoparasites on a host may vary with effects, host age and sex, and season. However, these effects have not been a focus of louse infestation studies of primates. Grooming in Japanese macaques is related to sex and age, with developmental changes in behavior corresponding to the timing of tooth eruption. Moreover, behavioral data for Japanese macaques suggest that lice load may differ with the season. Thus, we examined whether the number of louse eggs varies according to host macaque sex, age, and season, and whether it changes in response to tooth eruption. We counted unhatched and hatched eggs attached to the hair on six 1-cm(2) areas on the left wrist skin of culled macaques, using a stereoscopic microscope. We sampled five winter coats and three summer coats for each age class: infant, juvenile, adolescent, and adult. The number of unhatched and hatched eggs was related to age, but not to sex and season. There were significant differences in the number of unhatched eggs between infants and adults, juveniles and adults, and adolescents and adults. There were also significant differences in the number of hatched eggs between infants and adults, juveniles and adults, adolescents and adults. Tooth eruption did not influence the number of louse eggs. These results suggest that researchers should consider the age of host animals when assessing the relationship between grooming and ectoparasites.
  • Shin-ichi Hayama, Moe Tsuchiya, Kazuhiko Ochiai, Sachie Nakiri, Setsuko Nakanishi, Naomi Ishii, Takuya Kato, Aki Tanaka, Fumiharu Konno, Yoshi Kawamoto, Toshinori Omi
    Scientific Reports 7(1) 3528 2017年6月  査読有り
    To evaluate the biological effect of the Fukushima Daiichi nuclear disaster, relative differences in the growth of wild Japanese monkeys (Macaca fuscata) were measured before and after the disaster of 2011 in Fukushima City, which is approximately 70 km from the nuclear power plant, by performing external measurements on fetuses collected from 2008 to 2016. Comparing the relative growth of 31 fetuses conceived prior to the disaster and 31 fetuses conceived after the disaster in terms of body weight and head size (product of the occipital frontal diameter and biparietal diameter) to crown-rump length ratio revealed that body weight growth rate and proportional head size were significantly lower in fetuses conceived after the disaster. No significant difference was observed in nutritional indicators for the fetuses' mothers. Accordingly, radiation exposure could be one factor contributed to the observed growth delay in this study.
  • Hisashi Yoshimura, Masami Yamamoto, Maiko Moriya, Tomohiko Endo, Natsuko Sugiura, Takuya Kato, Yoko Matsuda, Toshiyuki Ishiwata, Hiroshi Kajigaya, Shinji Kamiya
    Journal of Zoo and Wildlife Medicine 48(1) 265-268 2017年3月  査読有り
    A young adult, female, free-ranging Japanese raccoon dog (Nyctereutes procyonoides viverrinus) with scabies infection was found dead as a result of traumatic injuries presumed to reflect vehicular trauma. Necropsy showed a large solid mass located on the left ovarian region, occupying a third of the abdominal cavity. Histologically, the mass contained complex tissues derived from three germinal layers, with areas of cuboidal or columnar epithelium, keratinized squamous epithelium, bone, cartilage, and adipose tissue. This paper presents the first morphologic description of ovarian teratoma in a raccoon dog.
  • Nana Ushine, Tatsuo Sato, Takuya Kato, Shin-ichi Hayama
    Journal of Veterinary Medical Science 79(9) 1627-1632 2017年  査読有り
  • 牛根 奈々, 加藤 卓也, 羽山 伸一
    日本鳥類標識協会誌 28(2) 51-70 2016年  査読有り
    鳥類への負担が最小限となるような雌雄の判別方法を確立するため,日本産鳥類11目42種の糞からDNAを抽出し,雌雄の判別を試みた.標的遺伝子として,性判別で有効であると報告されているspindlin,EE0.6,CHD領域を用いて,種ごとにプライマー等の条件を変えてpolymerase chain reaction (PCR)を行った.結果として,一部には増幅が確認できない種や検体が見受けられたものの,10目36種で雌雄に特異的な遺伝子領域の増幅が確認された.増幅が確認できなかった検体に関しては,性判別にもちいる糞を,抽出操作の前で十分に選定する作業が求められる.増幅が確認された検体の内,その内9種においては検体数と増幅した割合から,性判別に本研究の方法が実用的であることが判断できた.幼鳥から採取した糞からも性判別が可能であることからも,鳥類への負担が従来の方法と比較して少ないだけでなく,より判別可能条件が広い方法であることが示唆された.
  • 川道 美枝子, 三宅 慶一, 加藤 卓也, 山本 憲一, 八尋 由佳, 川道 武男
    京都歴史災害研究 = Historical disaster studies in Kyoto 16(16) 11-15 2015年3月  査読有り
  • Taiki Uno, Takuya Kato, Yoshikazu Seki, Eiichi Kawakami, Shin-ichi Hayama
    Journal of Reproduction and Development 60(6) 421-425 2014年12月  査読有り
    Feral raccoons (Procyon lotor) have been growing in number in Japan, and they are becoming a problematic invasive species. Consequently, they are commonly captured and killed in pest control programs. For effective population control of feral raccoons, it is necessary to understand their reproductive physiology and ecology. Although the reproductive traits of female raccoons are well known, those of the males are not well understood because specialized knowledge and facilities are required to study them. In this study, we first used a simple evaluation method to assess spermatogenesis and presence of spermatozoa in the tail of the epididymis of feral male raccoons by histologically examining the testis and epididymis. We then evaluated the possibility of using 7 variables-body weight, body length, body mass index, testicular weight, epididymal weight, testicular size and gonadosomatic index (GSI)-to estimate spermatogenesis and presence of spermatozoa in the tail of the epididymis. GSI and body weight were chosen as criteria for spermatogenesis, and GSI was chosen as the criterion for presence of spermatozoa in the tail of the epididymis. Because GSI is calculated from body weight and testicular weight, this model should be able to be used to estimate the reproductive state of male raccoons regardless of season and age when just these two parameters are known. In this study, GSI was demonstrated to be an index of reproductive state in male raccoons. To our knowledge, this is the first report of such a use for GSI in a member of the Carnivora.
  • Kazuhiko Ochiai, Shin-ichi Hayama, Sachie Nakiri, Setsuko Nakanishi, Naomi Ishii, Taiki Uno, Takuya Kato, Fumiharu Konno, Yoshi Kawamoto, Shuichi Tsuchida, Toshinori Omi
    Scientific Reports 4 5793 2014年7月  査読有り
    In April 2012 we carried out a 1-year hematological study on a population of wild Japanese monkeys inhabiting the forest area of Fukushima City. This area is located 70 km from the Fukushima Daiichi Nuclear Power Plant (NPP), which released a large amount of radioactive material into the environment following the Great East Japan Earthquake of 2011. For comparison, we examined monkeys inhabiting the Shimokita Peninsula in Aomori Prefecture, located approximately 400 km from the NPP. Total muscle cesium concentration in Fukushima monkeys was in the range of 78-1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.
  • Shin-ichi Hayama, Sachie Nakiri, Setsuko Nakanishi, Naomi Ishii, Taiki Uno, Takuya Kato, Fumiharu Konno, Yoshi Kawamoto, Shuichi Tsuchida, Kazuhiko Ochiai, Toshinori Omi
    PLOS ONE 8(7) e68530 2013年7月  査読有り
    Following the massive earthquake that struck eastern Japan on March 11, 2011, a nuclear reactor core meltdown occurred at the Fukushima Daiichi Nuclear Power Plant, operated by Tokyo Electric Power Company, and was followed by the release of large amounts of radioactive materials. The objective of this study was to measure the concentration of radiocesium Cs-134 and Cs-137 in the muscle of Japanese monkeys (Macaca fuscata) inhabiting the forest area of Fukushima City and to determine the change in concentration over time as well as the relationship with the level of soil contamination. Cesium concentrations in the muscle of monkeys captured at locations with 100,000-300,000 Bq/m(2) were 6,000-25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000-3,000 Bq/kg in some animals during and after December 2011 before returning to 1,000 Bq/kg in April 2012, after which it remained relatively constant. This pattern of change in muscle radiocesium concentration was similar to that of the change in radiocesium concentration in atmospheric fallout. Moreover, the monkeys feed on winter buds and the cambium layer of tree bark potentially containing higher concentrations of radiocesium than that in the diet during the rest of the year. The muscle radiocesium concentration in the monkeys related significantly with the level of soil contamination at the capture locations.
  • Takuya Kato, Taiki Uno, Yoshiyuki Fujioka, Kai Kobayashi, Erika Takayanagi, Shin-ichi Hayama
    The Journal of Veterinary Medical Science 74(5) 637-640 2012年5月  査読有り筆頭著者責任著者
    Due to the long parturition period of raccoons, we assumed that age at first conception of late born females was later than that of early born females. From March 2005 to September 2008, 201 females estimated to be younger than 24 months were separated into early- and late-born groups on the basis of their estimated birth month (to the nearest 2 months), and parous status and body mass index (BMI) were examined. Age at first conception of late-born females (over 18 months old) was estimated to be later than that of early-born females (over 12 months old). The average BM I in early-born individuals at 12 months old might have affected their ability to conceive because of body fat deposition.
  • Takuya Kato, Taiki Uno, Yoshiyuki Fujioka, Shin-ichi Hayama
    The Journal of Veterinary Medical Science 74(2) 181-188 2012年2月  査読有り筆頭著者責任著者
    We examined the use of external measurements and relative fat deposition of adult feral raccoons (Procyon lotor) to develop relative indices of body fat deposition in post-growth feral raccoons. From March 2006 to March 2010, 288 adult raccoon carcasses (110 males, 178 females) collected in Kanagawa Prefecture, Japan, which were determined to be 24 months old, were subjected to external measurements of body weight (BW), girth measurement (GM), and body mass index (BMI). To assess relative body fat deposition, we visually classified abdominal subcutaneous fat into three grades (Visible Fat Index [VFI]: I-III). Significant differences in the means of BW (both sexes:P &lt; 0.01), GM (females: P &lt; 0.05, males: P &lt; 0.01), and BMI (both sexes: P &lt; 0.01) were detected between seasons. Notably, the means of BW, GM, and BMI (all, both sexes: P &lt; 0.01) differed significantly between VFI grades. However, by discriminant analysis with BW. GM, and BMI as independent variables, we obtained a significant discriminant function (both sexes: P &lt; 0.01) for distinguishing VFI I from higher VFI grades, but no significant equation was obtained for distinguishing between VFI II and VFI III. Based on the obtained structure matrix of discriminant analysis, BMI was the most valuable component for the discrimination of VFI grades. Thus, we conclude that BMI is a suitable complementary index for assessing relative body fat deposition of adult feral raccoons in Kanagawa Prefecture and may be generalizable to populations in other areas.
  • 金田 正人, 加藤 卓也
    爬虫両棲類学会報 2011(2) 148-154 2011年9月  査読有り
  • K. Lee, T. Iwata, A. Nakadai, T. Kato, S. Hayama, T. Taniguchi, H. Hayashidani
    Zoonoses and Public Health 58(6) 424-431 2011年9月  査読有り
  • Kazumi Tei, Takuya Kato, Kenzo Hamamoto, Shin-ichi Hayama, Eiichi Kawakami
    The Journal of Veterinary Medical Science 73(2) 231-233 2011年2月  査読有り
    Reproduction of the masked palm civet (Paguma larvata) has not been well investigated in Japan. We examined 361 female masked palm civets harvested as nuisance animals between April 2007 and March 2009 in Kanagawa Prefecture and Tokyo Metropolis. Pregnant animals and placental scars-bearing animals were found only in 12 months old and over. In these animals, the observed rate of pregnant animals was 13.7% (29/212) and that of placental scar-bearing animals was 29.2% (62/212). The number of fetuses ranged from 1-4 (average 2.8), and the principal months of parturition estimated from the crown-rump lengths of fetuses were from March to November.
  • 三根 恵, 松本 淳, 加藤 卓也, 羽山 伸一, 野上 貞雄
    Japanese journal of zoo and wildlife medicine = 日本野生動物医学会誌 15(2) 101-104 2010年9月1日  査読有り
    2006年~2007年に,神奈川県逗子市および葉山町で捕獲されたアライグマProcyon lotorから直腸便と消化管内容を採取し,消化管内寄生蠕虫相を調査した。検出された寄生蠕虫種は合計8種で,その内訳は,不明線虫が2種,棘口吸虫科の吸虫類が2種,鉤頭虫類がSouthwellina hispidaPorrorchis otiSphaerirostris lanceoides,不明鉤頭虫の4種であった。調査地域のアライグマの寄生虫相は比較的単純であり,アライグマの原産地(北アメリカ)で認められる寄生虫種は確認されなかった。
  • 川道美枝子, 川道武男, 金田正人, 加藤卓也
    京都歴史災害研究 11(11) 31-40 2010年3月  査読有り
  • Takuya Kato, Yayoi Ichida, Kazumi Tei, Makoto Asano, Shin-ichi Hayama
    The Journal of Veterinary Medical Science 71(11) 1473-1478 2009年11月  査読有り筆頭著者責任著者
    In order to examine reproductive characteristics of feral raccoons in Kamakura, 335 raccoons were collected from March 2005 to March 2007. Raccoons were classified into five age classes: Class I, less than 5 months old; Class II, 5-11 months; Class III, 12-17 months; Class IV, 18-23 months; and Class V, over 23 months old. Females were examined for their age specific pregnancy rate and litter size. To determine when raccoon births occur in the region, birth Months of fetuses were estimated by the fetal growth rate, and birth months of Class I individuals were examined by tooth eruption. From fetuses of 18 pregnant females and 47 Class I individuals, it was found that the raccoon births occur from February to October. Of 163 females examined, all of Class I-II females were nulliparous. Pregnancy rate was 47.6% in Class III females, which was significantly lower than 75.0% in Class IV and 78.1% in Class V. The litter size of fetuses ranged from 2 to 5, and 3.9 on average; and that of placental scars ranged from I to 7, 3.8 on average. Our findings suggest that parturition of raccoons is a bimodal distribution and age at first parturition may Occur between 12 and 17 months old. In order to reduce the raccoon population Successfully, females of all ages should be captured throughout the year.
  • Takema Fukatsu, Takahiro Hosokawa, Ryuichi Koga, Naruo Nikoh, Takuya Kato, Shin-ichi Hayama, Haruo Takefushi, Ichirou Tanaka
    Applied and Environmental Microbiology 75(11) 3796-3799 2009年6月  査読有り
    A symbiotic bacterium of the macaque louse, Pedicinus obtusus, was characterized. The symbiont constituted a gammaproteobacterial lineage distinct from the symbionts of anthropoid primate lice, localized in the midgut epithelium and the ovaries and exhibiting AT-biased genes and accelerated molecular evolution. The designation "Candidatus Puchtella pedicinophila" was proposed for it.

MISC

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書籍等出版物

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講演・口頭発表等

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担当経験のある科目(授業)

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共同研究・競争的資金等の研究課題

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