Patterns of shoot mortality in Betula platyphylla in northern Japan     

Umeki K  Seino T  Lim EM  Honjo T 《Tree physiology》2006,26(5):623-632

To understand the development of crown structure in Betula platyphylla Sukatch., mortality patterns of long shoots were analyzed quantitatively. We selected 25 saplings growing under various light conditions and measured the relative photosynthetically active radiation (rPAR) at, and the three-dimensional position of, first-order branches. A long shoot was assigned "no buds" (NB) status if it lacked buds at the end of the growing season, including at the tips of short shoots. A long shoot was classified as dead if it was NB and all the offspring long shoots issuing from it were NB. The probability that a leafy long shoot (a current-year long shoot with leaves or an older long shoot with short shoots with leaves) would become NB by the end of the season was positively dependent on shoot age and branch age, and negatively dependent on shoot length, centripetal shoot order, branch height and rPAR at the branch. Randomization tests revealed that shoots became NB and dead in clusters of connected shoots. In particular, shoot clusters originating from 3-year-old shoots were more likely to die than expected if each shoot was assumed to become NB regardless of the connection. Stepwise logistic regression revealed that the maximum rPAR within the crown of an individual tree had a significant effect on the mortality rate of 3-year-old shoot clusters, together with the rPAR at the level of the branch and other structural entities. Correlative inhibition is an important mechanism for determining shoot mortality patterns.  相似文献   

Identification of small molecule activators of cryptochrome   总被引：1，自引：0，他引：1  

T Hirota  JW Lee  PC St John  M Sawa  K Iwaisako  T Noguchi  PY Pongsawakul  T Sonntag  DK Welsh  DA Brenner  FJ Doyle  PG Schultz  SA Kay 《Science (New York, N.Y.)》2012,337(6098):1094-1097

Impairment of the circadian clock has been associated with numerous disorders, including metabolic disease. Although small molecules that modulate clock function might offer therapeutic approaches to such diseases, only a few compounds have been identified that selectively target core clock proteins. From an unbiased cell-based circadian phenotypic screen, we identified KL001, a small molecule that specifically interacts with cryptochrome (CRY). KL001 prevented ubiquitin-dependent degradation of CRY, resulting in lengthening of the circadian period. In combination with mathematical modeling, our studies using KL001 revealed that CRY1 and CRY2 share a similar functional role in the period regulation. Furthermore, KL001-mediated CRY stabilization inhibited glucagon-induced gluconeogenesis in primary hepatocytes. KL001 thus provides a tool to study the regulation of CRY-dependent physiology and aid development of clock-based therapeutics of diabetes.  相似文献   

Reference values of hematological and biochemical parameters for the world smallest microminipigs     

Kawaguchi H  Yamada T  Miura N  Takahashi Y  Yoshikawa T  Izumi H  Kawarasaki T  Miyoshi N  Tanimoto A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(7):933-936

In this study, we demonstrated growth curves and reference values for hematological and serum biochemical parameters of Microminipigs, the world smallest experimental minipigs. In both male and female animals, the body weights (BWs) at 3 and 6 months of age were <5 kg and <10 kg, respectively, and growth curve revealed almost plateau (approximately 20 kg BW) after 18 months of age. Major hematological and serum biochemical parameters showed no gender differences and the values were very similar to those in G?ttingen and Yukatan minipigs. The values obtained in this study can serve as fundamental reference, and thereby facilitate the use of Microminipig in life science research.  相似文献   

Pathological classification of canine mammary tumor based on quantifying mRNA levels of hormonal receptors, SATB1, and snail in tissue and fine needle biopsy samples     

Komatsu T  Iwano H  Ebisawa M  Watabe A  Endo Y  Hirayama K  Taniyama H  Kadosawa T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(6):719-726

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Spironolactone, but not Eplerenone, Impairs Glucose Tolerance in a Rat Model of Metabolic Syndrome     

Homma T  Fujisawa M  Arai K  Ishii M  Sada T  Ikeda M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(8):1015-1022

Although some clinical studies have suggested that spironolactone (SPL), a mineralocorticoid receptor (MR) antagonist, appears to increase the blood glucose levels, experimental studies have not supported this notion. Here, we investigated the effect of SPL on blood glucose levels in SHR/NDmcr-cp(cp/cp) (ND) rats, an animal model of metabolic syndrome, in comparison with that of eplerenone (EPL), another MR antagonist. At the same dose of 100 mg/kg, SPL and EPL increased the urinary sodium-to-potassium ratio to a comparable extent, indicating that both agents have similar renal MR antagonistic efficacy in ND rats. Interestingly, SPL but not EPL significantly increased the level of blood glucose. The oral glucose tolerance test revealed that treatment with SPL led to glucose intolerance. The levels of serum insulin and adiponectin, regulators of the blood glucose level, were virtually unaffected by treatment with SPL. On the other hand, SPL induced a marked increase in the blood level of aldosterone, known to be a risk factor for insulin resistance. These results demonstrate that in comparison with EPL, SPL characteristically impairs glucose tolerance in an animal model of metabolic syndrome, in association with a higher blood level of aldosterone.  相似文献   

CONTRAST AGENT Gd‐EOB‐DTPA (EOB·Primovist®) FOR LOW‐FIELD MAGNETIC RESONANCE IMAGING OF CANINE FOCAL LIVER LESIONS     

Yonetomi D  Kadosawa T  Miyoshi K  Nakao Y  Homma E  Hanazono K  Yamada E  Nakamura K  Ijiri A  Minegishi N  Maetani S  Hirayama K  Taniyama H  Nakade T 《Veterinary radiology & ultrasound》2012,53(4):371-380

Contrast‐enhanced magnetic resonance (MR) imaging with a new liver‐specific contrast agent gadolinium‐ethoxybenzyl‐diethylenetriamine penta‐acetic acid (Gd‐EOB‐DTPA; EOB·Primovist®) was studied in 14 normal beagles and 9 dogs with focal liver lesions. Gd‐EOB‐DTPA accumulates in normally functioning hepatocytes 20 min after injection. As with Gd‐DTPA, it is also possible to perform a dynamic multiphasic examination of the liver with Gd‐EOB‐DTPA, including an arterial phase and a portal venous phase. First, a reliable protocol was developed and the appropriate timings for the dynamic study and the parenchymal phase in normal dogs using Gd‐EOB‐DTPA were determined. Second, the patterns of these images were evaluated in patient dogs with hepatic masses. The optimal time of arterial imaging was from 15 s after injection, and the optimal time for portal venous imaging was from 40 s after injection. Meanwhile, the optimal time to observe changes during the hepatobiliary phase was from 20 min after injection. In patient dogs, 11 lesions were diagnosed as malignant tumors; all were hypointense to the surrounding normal liver parenchyma during the hepatobiliary phase. Even with a low‐field MR imaging unit, the sequences afforded images adequate to visualize the liver parenchyma and to detect tumors within an appropriate scan time. Contrast‐enhanced MR imaging with Gd‐EOB‐DTPA provides good demarcation on low‐field MR imaging for diagnosing canine focal liver lesions.  相似文献   

Decreased gene expression of insulin signaling genes in insulin sensitive tissues of obese cats     

Mori A  Lee P  Takemitsu H  Iwasaki E  Kimura N  Yagishita M  Hayasaka M  Arai T 《Veterinary research communications》2009,33(4):315-329

Type 2 diabetes mellitus (DM) animal models have provided ample opportunity for investigating pathogenesis, as well as to evaluate novel treatment and prevention options for the disease. Because the domestic cat shares a similar environment with humans, it is also confronted with many similar risk factors for diabetes, such as physical inactivity and obesity. Obesity is a significant risk factor for diabetes in cats, and as such, the domestic cat may serve as an ideal model for investigating obesity induced insulin resistance. This study determined changes in insulin signaling genes within insulin sensitive tissues of obese felines. Quantitative RT-PCR was performed to determine mRNA levels of three important insulin signaling genes which have been implicated with insulin resistance: insulin receptor substrate (IRS)-1, IRS-2, and phosphatidylinositol 3’-kinase (PI3-K) p85α. Obese cats had significantly lower IRS-2 and PI3-K p85α mRNA levels in liver and skeletal muscle as compared to control cats. This down regulation of insulin signaling genes in obese cats mirrors that of obese humans and rodents suffering from insulin resistance. Interestingly, preprandial blood tests indicated that our obese cats were no different from control cats with regards to glucose tolerance and insulin resistance, thus indicating that the obese cats used in our study had a moderate level of obesity. Therefore, insulin signaling gene alterations were occurring in insulin sensitive tissues of moderately obese felines before glucose intolerance was clinically evident. As such, the monitoring of key insulin signaling genes may have some important diagnostic value to determine the risk level and degree of obesity induced insulin resistance.  相似文献   

Hindbrain decompression in a dog with scoliosis associated with syringomyelia     

Takagi S  Kadosawa T  Ohsaki T  Hoshino Y  Okumura M  Fujinaga T 《Journal of the American Veterinary Medical Association》2005,226(8):1359-63, 1347

A 6-month-old female Border Collie was examined because of a 1-month history of progressive curvature of the cervical portion of the vertebral column. Radiography revealed severe cervical and thoracic scoliosis. Cervical syringomyelia and hydrocephalus were observed by means of magnetic resonance imaging. Suboccipital craniotomy and laminectomy of the first cervical vertebra were performed, and substantial improvement in the scoliosis and syringomyelia was observed 3 months after surgery. No recurrences were seen during the first year after surgery.  相似文献   

Dual-subtype vaccine (Fel-O-Vax FIV) protects cats against contact challenge with heterologous subtype B FIV infected cats     

Kusuhara H  Hohdatsu T  Okumura M  Sato K  Suzuki Y  Motokawa K  Gemma T  Watanabe R  Huang C  Arai S  Koyama H 《Veterinary microbiology》2005,108(3-4):155-165

Fel-O-Vax FIV is a dual-subtype vaccine consisting of inactivated whole viruses of subtype A (Petaluma strain) and subtype D (Shizuoka strain). The efficacy of this vaccine against heterologous subtype A strain challenge was demonstrated, but it is unclear whether the result reflects efficacy in the field. In this study, we evaluated the efficacy of this vaccine against contact challenge by exposing both vaccinated and unvaccinated control animals with cats infected with Aomori-2 strain belonging to subtype B, a subtype prevalent in many regions of the world. Nineteen specific-pathogen-free (SPF) cats were divided into a vaccinated group (six cats), an unvaccinated control group (eight cats), and a challenge group (five cats), and maintained in the same room. Cats were monitored for FIV proviral DNA by nested PCR and for FIV-specific antibody levels by ELISA. After 1 year of commingling, each cat in the vaccinated group was given a booster dose. In addition, the original challenge group was removed and replaced with another challenge group of SPF cats, which were inoculated with the Aomori-2 strain. FIV infection was confirmed in four of the eight animals in the unvaccinated control group by the 29th week in the second year of commingling. In contrast, all of the animals were negative in the vaccinated group. These findings confirmed the efficacy of this vaccine against heterologous stains classified as subtype B, and suggested that the vaccine exhibits broad efficacy against genetically diverse FIV.  相似文献   

Matrix metalloproteinase inhibitor RECK expression in canine tumors   总被引：5，自引：0，他引：5  

Takagi S  Kato Y  Asano K  Ohsaki T  Bosnakovski D  Hoshino Y  Okumura M  Kadosawa T  Fujinaga T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(8):761-767

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