Seroprevalence of Bartonella infection in American free-ranging and captive pumas (Felis concolor) and bobcats (Lynx rufus)     

Chomel BB  Kikuchi Y  Martenson JS  Roelke-Parker ME  Chang CC  Kasten RW  Foley JE  Laudre J  Murphy K  Swift PK  Kramer VL  O'brien SJ 《Veterinary research》2004,35(2):233-241

Bartonella henselae is the main agent of cat scratch disease in humans and domestic cats are the main reservoir of this bacterium. We conducted a serosurvey to investigate the role of American wild felids as a potential reservoir of Bartonella species. A total of 479 samples (439 serum samples and 40 Nobuto strips) collected between 1984 and 1999 from pumas (Felis concolor) and 91 samples (58 serum samples and 33 Nobuto strips) collected from bobcats (Lynx rufus) in North America, Central America and South America were screened for B. henselae antibodies. The overall prevalence of B. henselae antibodies was respectively 19.4% in pumas and 23.1% in bobcats, with regional variations. In the USA, pumas from the southwestern states were more likely to be seropositive for B. henselae (prevalence ratio (PR) = 2.82, 95% confidence interval (CI) = 1.55, 5.11) than pumas from the Northwest and Mountain states. Similarly, adults were more likely to be B. henselae seropositive than juveniles and kittens (PR = 1.77, 95% CI = 1.07, 2.93). Adult pumas were more likely to have higher B. henselae antibody titers than juveniles and kittens (p = 0.026). B. henselae antibody prevalence was 22.4% (19/85) in bobcats from the USA and 33.3% (2/6) in the Mexican bobcats. In the USA, antibody prevalence varied depending on the geographical origin of the bobcats. In California, the highest prevalence was in bobcats from the coastal range (37.5%). These results suggest a potential role of wild felids in the epidemiological cycle of Bartonella henselae or closely related Bartonella species.  相似文献   

In vitro and in vivo developmental ability of oocytes derived from porcine primordial follicles xenografted into nude mice     

Kikuchi K  Kaneko H  Nakai M  Noguchi J  Ozawa M  Ohnuma K  Kashiwazaki N 《The Journal of reproduction and development》2006,52(1):51-57

We evaluated the developmental ability of oocytes in porcine primordial follicles xenografted into nude mice. Ovarian tissues from 20-day-old piglets, in which most of the follicles were primordial, were transplanted under the kidney capsules of ovariectomized nude mice. Forty-nine to 89 days after grafting (mean +/- SEM, 66.9 +/- 1.9 days; n = 64), the host mice showed the presence of cornified epithelial cells in their vaginal smears for the first time. The mice were then treated with 4 IU of equine chorionic gonadotropin (eCG) 60 days after first detection of vaginal cornification. Oocytes were collected from the host mice 48 h after treatment with eCG, and then matured. The maturation rates, based on the incidence of first polar body, ranged from 25.1% to 42.5%. They were then fertilized in vitro and cultured in vitro for 6 days, or transferred into estrous-synchronized recipients and recovered after 6 days. On Day 6 of culture, 15.4% of the matured oocytes had cleaved to the 2- to 8-cell stage. However, neither the embryos cultured in vitro nor those transferred and recovered developed to advanced embryonic stages, such as morulae or blastocysts. This result suggests that the developmental ability of xenografted oocytes is insufficient, even after in vitro maturation. Further strategies, such as improvement of hormonal treatment for host mice, are required to enable oocytes in xenografted ovarian tissues to acquire the cytoplasmic maturation necessary for embryonic development.  相似文献   

Comparing the osteogenic potential of canine mesenchymal stem cells derived from adipose tissues, bone marrow, umbilical cord blood, and Wharton's jelly for treating bone defects     

Byung-Jae Kang  Hak-Hyun Ryu  Sung Su Park  Yoshihisa Koyama  Masanori Kikuchi  Heung-Myong Woo  Wan Hee Kim  Oh-Kyeong Kweon 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(3):299-310

Alternative sources of mesenchymal stem cells (MSCs) for replacing bone marrow (BM) have been extensively investigated in the field of bone tissue engineering. The purpose of this study was to compare the osteogenic potential of canine MSCs derived from adipose tissue (AT), BM, umbilical cord blood (UCB), and Wharton''s jelly (WJ) using in vitro culture techniques and in vivo orthotopic implantation assays. After canine MSCs were isolated from various tissues, the proliferation and osteogenic potential along with vascular endothelial growth factor (VEGF) production were measured and compared in vitro. For the in vivo assay, MSCs derived from each type of tissue were mixed with β-tricalcium phosphate and implanted into segmental bone defects in dogs. Among the different types of MSCs, AT-MSCs had a higher proliferation potential and BM-MSCs produced the most VEGF. AT-MSCs and UCB-MSCs showed greater in vitro osteogenic potential compared to the other cells. Radiographic and histological analyses showed that all tested MSCs had similar osteogenic capacities, and the level of new bone formation was much higher with implants containing MSCs than cell-free implants. These results indicate that AT-MSCs, UCB-MSCs, and WJ-MSCs can potentially be used in place of BM-MSCs for clinical bone engineering procedures.  相似文献   

Abundance and use of cavity trees at the tree- and stand-levels in natural and plantation forests in Hokkaido, Japan     

Kokoro Kikuchi  Takumi Akasaka  Yuichi Yamaura  Futoshi Nakamura 《Journal of Forest Research》2013,18(5):389-397

The conservation of cavity trees in plantations is important for maintaining biodiversity because cavity trees are one of the forest attributes most strongly affected by forestry operations. We surveyed the occurrence of cavities at the tree-level and the abundance of cavity trees and the number of uses by secondary cavity users at the stand-level in natural and conifer plantation forests in Hokkaido, Japan. We classified cavities into two types by their formation processes: excavated and non-excavated. Excavated cavities were more common in dead trees than in live trees. Non-excavated cavities showed high occurrence in dead and live broad-leaved trees. The abundance of non-excavated cavity trees was two times greater than that of excavated cavity trees in natural forests, but, in plantations, excavated cavity trees were dominant. The abundance of non-excavated cavity trees was lower in thinned plantations than in not-thinned plantations. The number of cavity uses increased with the number of cavity trees, indicating the importance of maintaining cavity trees. Conifer plantations are established by removing native broad-leaved trees, which results in a lower abundance of non-excavated cavity trees in these locations. The conservation of broad-leaved trees is important for maintaining the current and future resource of non-excavated cavity trees in plantation forests, as is the conservation of dead trees, which showed a high occurrence of excavated cavities.  相似文献   

Evaluation of genetic diversity of bread wheat landraces from Pakistan by AFLP and implications for a future collection strategy   总被引：1，自引：0，他引：1  

Ryoko Hirano  Akira Kikuchi  Makoto Kawase  Kazuo N. Watanabe 《Genetic Resources and Crop Evolution》2008,55(7):1007-1015

We used amplified-fragment-length polymorphism (AFLP) markers to evaluate genetic variation in a set of bread wheat (Triticum aestivum L.) landraces and improved materials. Landraces collected from different geographic and agro-ecological zones in Pakistan in 1987, 1989 and 1991 were separated into two groups based on their geographic origins: northern (Himalaya) and south-western (Balochistan) Pakistan. Six AFLP primer combinations detected 453 AFLP markers in the 43 landrace accessions and four high-yield varieties (HYVs). Of these, 225 (49.67%) were rare (shared with < 5% of all accessions). Among these rare alleles, 23 (10.22%) were common in the Himalaya (shared with > 10% of accessions collected there) but were not found in Balochistan. We conclude that there is a higher probability of collecting rare alleles at overall, but which are in contrast locally common ones in the Himalayan region. Gene diversity was 0.17 in the Himalayan group and 0.15 in the Balochistan group. Considerable genetic variability was found in both groups. Accessions from different agro-ecological zones were indistinguishable by cluster analysis, indicating intensive seed trading within the country. Cluster analysis indicated that the landraces and the HYVs are genetically distinct; suggesting that genetic erosion of wheat landraces has been unlikely taken in place. This study provides an example of how analysis of existing materials and data, can serve as a basis for future collection planning and conservation policies.  相似文献   

Loop-mediated isothermal amplification for the rapid, sensitive, and specific detection of the O9 group of Salmonella in chickens     

Okamura M  Ohba Y  Kikuchi S  Suzuki A  Tachizaki H  Takehara K  Ikedo M  Kojima T  Nakamura M 《Veterinary microbiology》2008,132(1-2):197-204

In the present study, the loop-mediated isothermal amplification (LAMP) assay was developed to amplify the fragments of the O9 Salmonella-specific insertion element and evaluated in the laboratory for its potential use in a field situation, such as poultry farms. Among the bacteria tested, a positive reaction was observed only for 128 strains of 6 serovars of the O9 group Salmonella, such as Enteritidis (SE) and Pullorum. The detection limit of the LAMP assay was 10(3)CFU/ml, which was more sensitive than that of the polymerase chain reaction (PCR) assay with the same target gene (10(6)CFU/ml). The final results were obtained within 30 min for the LAMP assay, while the PCR assay needed a total of 120 min. When the LAMP assay was applied to the enrichment broth mixed with cecal dropping samples either spiked with SE in vitro or excreted by SE-inoculated hens, the results were comparable to those of the conventional plating method including 2 separate enrichments. In conclusion, the LAMP assay developed in the present study is an effective method for the specific detection of the O9 group Salmonella serovars, including SE.  相似文献   

Affected homologous chromosome pairing and phosphorylation of testis specific histone, H2AX, in male meiosis under FKBP6 deficiency     

Noguchi J  Ozawa M  Nakai M  Somfai T  Kikuchi K  Kaneko H  Kunieda T 《The Journal of reproduction and development》2008,54(3):203-207

A gene for FK506 binding protein 6 (Fkbp6) expresses during a specific stage of male and female meiosis. Disruption of the gene influences male reproduction, i.e. arrests spermatogenesis, but not female reproduction. Using the mouse model (targeted disruption), the role of the gene in homologous chromosome pairing has been demonstrated in a previous study. For further understanding the function of Fkbp6 in chromosome synapsis, we evaluated chromosome pairings during male meiosis in the as/as rat, a spontaneous null mutation, and compared them with those of the mouse model. Electron microscopy of the pachytene nuclei unveiled several types of abnormal chromosome pairing in the rat model, as shown in the mouse previously. The frequencies of aberrant pairings in the knockout mice and mutant rats were 42 of 67 nuclei (62.7%) and 20 out of 74 nuclei (27.0%), respectively. In order to clarify the mechanism of male specific infertility in Fkbp6 deficiency, the localization of gammaH2AX, a marker protein of XY chromosome inactivation during male meiosis, was examined. Immunostaining of gammaH2AX unveiled normal localization of the molecule to XY chromosomes (XY body) in both models, showing the independency of FKBP6 in sex chromosome inactivation. Besides the XY body, focal localization of gammaH2AX was observed in accordance with the unsynapsed chromosomes in both types of null animal. These results indicate the fundamental role of Fkbp6 in homologous chromosome synapsis during male meiosis. In conclusion, male specific infertility under Fkbp6 deficiency remains unsolved.  相似文献   

Endocrine status and development of porcine testicular tissues in host mice     

Kaneko H  Kikuchi K  Nakai M  Noguchi J 《The Journal of reproduction and development》2008,54(6):480-485

Clarification of the endocrine status of host mice provides us with basic knowledge with which we can manipulate the growth and function of xenografted testicular tissues. We investigated the hormonal profiles of castrated mice grafted with porcine immature testicular tissues from 30 to 210 or more days after grafting (day 0=castration and grafting). The serum follicle stimulating hormone (FSH) concentrations of the host mice declined (P<0.05) from day 60 compared with those of the castrated, ungrafted mice. The serum inhibin and testosterone levels were higher (P<0.05) than those in the castrated, ungrafted mice from days 30 and 90 days, respectively. The inhibin levels further increased (P<0.05) from day 90, during which time the levels were higher (P<0.05) than those in the intact male mice. In the grafts, formation of lumens occurred in the seminiferous cords on day 90 and spermatozoa appeared in the lumens from day 120. However, spermatogenesis in the grafts did not reach the qualitatively normal levels observed in adult boars. The intensity of the immune reaction to inhibin alpha subunits in the Sertoli cells of the grafts decreased with differentiation of the seminiferous tubules. The present findings indicate that a feedback loop was established between the mouse hypothalamo-pituitary axis and the grafted porcine tissues from 60 days post-grafting. The results also indicate that the serum inhibin levels in the host mice remained high even after the appearance of lumens in the seminiferous tubules of the grafted tissues; this is strikingly different to the situation in normal male animals, in which the serum inhibin levels decline at around the time of tubular differentiation. The lack of efferent ducts in the tubules of the grafted tissues probably caused the accumulation of inhibin to be released into the lumens, resulting in high concentrations of circulating inhibin. These high levels of inhibin may directly affect spermatogenic activity and suppress FSH secretion.  相似文献   

Selected Aspects of Advanced Porcine Reproductive Technology     

K Kikuchi  N Kashiwazaki  T Nagai  M Nakai  T Somfai  J Noguchi  H Kaneko 《Reproduction in domestic animals》2008,43(S2):401-406

In vitro fertilization (IVF) of in vitro matured (IVM) oocytes in pigs has become the most popular method of studying gametogenesis and embryogenesis in this species. Furthermore, because of recent advances in in vitro culture (IVC) of IVM–IVF embryos, in vitro production (IVP) of embryos now enables us to generate viable embryos as successfully as for in vivo -derived embryos and with less cost and in less time. These technologies contribute not only to developments in reproductive physiology and agriculture but also to the conservation of porcine genetic resources and the production of cloned or genetically modified pigs. However, in IVP, there still remains the problem of abnormal ploidy, which is caused by performing procedures under non-physiological conditions. In recent years, unique technologies such as intracytoplasmic sperm injection (ICSI) or xenografting of gonadal tissue into immunodeficient experimental animals have been developed to help conserve gamete resources. These technologies combined with IVP are expected to be useful for the conservation of gametes from important genetic resources. Here, we discuss the developmental ability and normality of porcine IVP embryos and also the utilization of ICSI and xenografting in advancing biotechnology in pigs.  相似文献   

Sucrose assists selection of high‐quality oocytes in pigs          下载免费PDF全文

Thanh Quang Dang‐Nguyen  Hiep Thi Nguyen  Tamas Somfai  David Wells  Nguyen Thi Men  Nguyen Viet‐Linh  Junko Noguchi  Hiroyuki Kaneko  Kazuhiro Kikuchi  Takashi Nagai 《Animal Science Journal》2018,89(6):880-887

We investigated whether high‐quality in vitro matured (IVM) oocytes can be distinguished from poor ones based on the morphological changes after treatment with hyperosmotic medium containing 0.2 mol/L sucrose in pigs. We hypothesize that IVM oocytes maintaining round shape have higher quality than mis‐shapened oocytes following dehydration. Oocyte quality was verified by determining embryonic developmental competence using in vitro fertilization, nuclear transfer and parthenogenetic activation. In all cases, the round oocytes had greater (p < .05) developmental competence than that of mis‐shapened oocytes in terms of blastocyst rate and total cell number in blastocysts obtained after 6 days of in vitro culture. We also confirm that round aged oocytes are higher in quality than mis‐shapened aged oocytes. In an attempt to find out why high‐quality oocytes maintain a round shape whereas poorer oocytes become mis‐shapened following sucrose treatment, we examined the arrangement of actin microfilaments and microtubules. Abnormal organization of these cytoskeletal components was higher (p < .05) in mis‐shapened oocytes compared to round oocytes after 52 hr of IVM. In conclusion, sucrose treatment helps selection of high‐quality oocytes, including aged oocytes, in pigs. Abnormal cytoskeleton arrangements partly explain for low developmental competence of mis‐shapened oocytes.  相似文献