N -ethyl- N -nitrosourea induces retinal photoreceptor damage in adult rats     

Yoshizawa K  Sasaki T  Uehara N  Kuro M  Kimura A  Kinoshita Y  Miki H  Yuri T  Tsubura A 《Journal of toxicologic pathology》2012,25(1):27-35

Seven-week-old male Lewis rats received a single intraperitoneal injection of N-ethyl-N-nitrosourea (ENU) (100, 200, 400 or 600 mg/kg), and retinal damage was evaluated 7 days after the treatment. Sequential morphological features of the retina and retinal DNA damage, as determined by a TUNEL assay and phospho-histone H2A.X (γ-H2AX), were analyzed 3, 6, 12, 24 and 72 hr, 7 days, and/or 30 days after 400 mg/kg ENU treatment. Activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) was analyzed immunohistochemically by poly (ADP-ribose) (PAR) expression in response to DNA damage of the retina. All rats that received ≥ 400 mg/kg of ENU developed retinal degeneration characterized by the loss of photoreceptor cells in both the central and peripheral retina within 7 days. In the 400 mg/kg ENU-treated rats, TUNEL-positive signals were only located in the photoreceptor cells and peaked 24 hr after ENU treatment. The γ-H2AX signals in inner retinal cells appeared at 24 hr and peaked at 72 hr after ENU treatment, and the PAR signals selectively located in the photoreceptor cell nuclei appeared at 12 hr and peaked at 24 hr after ENU treatment. However, degeneration was restricted to photoreceptor cells, and no degenerative changes in inner retinal cells were seen at any time points. Retinal thickness and the photoreceptor cell ratio in the central and peripheral retina were significantly decreased, and the retinal damage ratio was significantly increased 7 days after ENU treatment. In conclusion, ENU induced retinal degeneration in adult rats that was characterized by photoreceptor cell apoptosis through PARP activity.  相似文献   

Effects of coumestrol administration to maternal mice during pregnancy and lactation on renal Ca metabolism in neonatal mice     

Michihisa UEDA  Yoshihiro HORIGUCHI  Miki SUGIMOTO  Shuntaro IKEDA  Shinichi KUME 《Animal Science Journal》2012,83(6):469-473

The present study was conducted to clarify the effects of coumestrol administration to maternal mice during pregnancy and lactation on serum Ca and Ca metabolism in their neonatal mice. From 6.5 to 16.5 days post coitus and from 3 to 10 days after parturition, maternal mice were administered at 200 µg/kg body weight/day of coumestrol. Coumestrol administration did not affect weight gains, serum Ca and the expression of vitamin D receptor (VDR) protein in the kidney of neonatal mice, but weight gains of maternal mice were decreased by coumestrol administration. Coumestrol administration increased the messenger RNA (mRNA) expressions of epithelial Ca channels 1 (ECaC1) and VDR in the kidney of neonatal mice, and also increased the mRNA expressions of ECaC2 in the kidney and small intestine of male neonatal mice. The mRNA expressions of ECaC1, ECaC2, calbindin‐D_9k (CaBP‐9k) and estrogen receptor (ER)α in the kidney and VDR in the small intestine of male neonatal mice were higher than those of female mice. Thus, coumestrol administration to maternal mice during pregnancy and lactation may affect renal Ca metabolism in neonatal mice, especially male neonatal mice via maternal milk.  相似文献   

Co-culture of carp (Cyprinus carpio) kidney haematopoietic cells with feeder cells resulting in long-term proliferation of T-cell lineages     

Fumihiko Katakura  Fumio Takizawa  Miyuki Yoshida  Takuya Yamaguchi  Kyosuke Araki  Mitsuru Tomana  Miki Nakao  Tadaaki Moritomo  Teruyuki Nakanishi 《Veterinary immunology and immunopathology》2009,131(1-2):127-136

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Implantation of permanent transvenous endocardial pacemaker in a dog with atrioventricular block     

Kobayashi M  Hoshi K  Hirao H  Shimizu M  Shimamura S  Akiyama M  Tanaka R  Maruo K  Yamane Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(10):1131-1134

A 10-year old male mongrel dog was presented to the University Veterinary Teaching Hospital with a two-month history of episodic syncope. Twenty-four hr Holter electrocardiographic (ECG) recording revealed frequent episodes of advanced atrioventriculer block with long periods of ventricular asystole. The cause of syncope was determined to be Adams-Stokes syndrome exhibited bradyarrhythmia. After the animal failed to respond to medical therapy, permanent transvenous pacemaker implantation was performed. Postoperative Holter ECG showed 100 beat per min programmed pacemaker rhythm, which indicated successful capture of the artificial pacing. The dog recovered smoothly from the operation and syncopal episodes completely disappeared. Six months after the surgery, no complications were observed and the dog's quality of life has dramatically improved.  相似文献   

Tree mortality rates and tree population projections in Baltimore, Maryland, USA     

David J. Nowak  Miki Kuroda  Daniel E. Crane 《Urban Forestry & Urban Greening》2004,2(3):139-147

Based on re-measurements (1999 and 2001) of randomly-distributed permanent plots within the city boundaries of Baltimore, Maryland, trees are estimated to have an annual mortality rate of 6.6% with an overall annual net change in the number of live trees of –4.2%. Tree mortality rates were significantly different based on tree size, condition, species, and land use. Morus alba, Ailanthus altissima, and trees in small diameter classes, poor condition, or in transportation or commercial – industrial land uses exhibited relatively high mortality rates. Trees in medium- to low-density residential areas exhibited low mortality rates. The high mortality rate for A. altissima is an artifact of this species distribution among land use types (24% were in the transportation land use). Based on a new tree population projection model that incorporates Baltimore's existing tree population and annual mortality estimates, along with estimates of annual tree growth, Baltimore's urban forest is projected to decline in both number of trees and canopy area over the next century. Factors affecting urban tree mortality are discussed.  相似文献   

Availability of NMR microscopic observation of mouse embryo disorder: examination in malformations induced by maternal administration of retinoic acid     

Sugimoto M  Manabe N  Morita M  Tanaka T  Okamoto R  Imanishi S  Miyamoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(5):427-433

Nuclear magnetic resonance (NMR) microscopy is a magnetic resonance imaging method with enhanced spatial resolution due to the use of a high static magnetic field and high magnetic field gradients. It is considered to be a useful tool for non-invasive and continuous investigation of tissue and organs at the histological level. In this study, we applied NMR microscopy to assessment of morphology in mouse embryos using a developmental disorder model induced by retinoic acid administration. Pregnant mice were given 50 mg/kg all-trans retinoic acid at 8.5 dpc. Embryos were collected at several time points after treatment and examined by NMR microscopy after fixation. Two-dimensional and three-dimensional spin echo sequences were used. Tissue contrast on two-dimensional images changed according to length of repetition time and echo time, and also to developmental stage of embryos. Two-dimensional and three-dimensional images nondestructively demonstrated defects in development of the skeleton and soft tissue, e.g. hypoplasia of vertebrae in the lumbar and tail regions and dysplasia of the spinal cord, in embryos exposed to retinoic acid. These morphological abnormalities were confirmed by conventional assessment after imaging. Although further improvements are required, NMR microscopy will provide a new approach for multi-parameter assessment of embryonic development under physiological and pathological conditions.  相似文献   

Steroidal but not embryonic regulation of mucin 1 expression in bovine endometrium     

Kaiyu KUBOTA  Masafumi MIWA  Ken-Go HAYASHI  Misa HOSOE  Miki SAKATANI 《The Journal of reproduction and development》2021,67(6):386

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Typing of Rhodococcus equi isolated from submaxillary lymph nodes of pigs in Japan   总被引：1，自引：0，他引：1  

M Katsumi  N Kodama  Y Miki  T Hiramune  N Kikuchi  R Yanagawa  M Nakazawa 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1991,38(4):299-302

Isolation of Rhodococcus equi from the submaxillary lymph nodes of pigs, with or without caseous lymphadenitis, and typing of the isolates by two serological methods were carried out. The rate of isolation of the organisms from the lymph nodes of pigs was 5 times higher in the lymph nodes with caseous lymphadenitis than in those without the lesion. Of 219 isolates, 146 (66.7%) were typable by the method of Prescott, while all the 219 isolates (100%) were typable by the method of Nakazawa et al. The most frequently isolated were serotype 2 of Prescott (identical to serogroup 16 of Nakazawa et al.), and serogroup 3 of Nakazawa et al., which did not correspond with any serotypes of Prescott. Serotypes/serogroups of R. equi from pigs were thus first clarified in Japan.  相似文献   

Vertical movement of a chum salmon Oncorhynchus keta in the western North Pacific Ocean as determined by a depth-recording archival tag     

Yukimasa Ishida  Akira Yano  Masatoshi Ban  Miki Ogura 《Fisheries Science》2001,67(6):1030-1035

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Molecular Monitoring of hrpB-disrupted Mutant of Ralstonia solanacearum in Tomato Plants     

Yoshinori MATSUDA  Hideyoshi TOYODA  Yasunari KATO  Koji KAKUTANI  Takayuki NAKANISHI  Miki BINGO  Teruo NONOMURA  Seiji OUCHI 《Journal of General Plant Pathology》2000,66(1):59-63

A nonpathogenic mutant of Ralstonia solanacearum was produced by the insertion of transposon Tn4431. The mutagenized gene was then cloned from a genomic DNA library by the gene tagging method, using the labeled lux operon located on Tn4431 of pUCD623 as a hybridization probe. From nucleotide sequence analysis of the transposon-inserted genomic clone, the hrpB gene was shown to be disrupted by the inserted transposon. Tomato plants were inoculated with the hrpB-disrupted mutant bacteria, for which multiplication and translocation were then monitored using the colony hybridization method. In addition, the original pathogenic bacteria in which the lux operon had been functionally ligated with the genomic promoter were also used for inoculation and traced by their bioluminescence. Multiplication of the hrpB-disrupted mutant was suppressed initially in the invaded root tissues and then in upper hypocotyl after translocation, suggesting that the pathogenic strain of R. solanacearum overcomes at least two steps of host responses expressed in root and hypocotyl tissues. Thus, our approach for molecular monitoring of the bacteria enabled us to precisely analyze the infection behavior of the pathogenic bacteria in planta. Received 16 April 1999/ Accepted in revised form 10 August 1999  相似文献