Elastic domains regulate growth and organogenesis in the plant shoot apical meristem     

Kierzkowski D  Nakayama N  Routier-Kierzkowska AL  Weber A  Bayer E  Schorderet M  Reinhardt D  Kuhlemeier C  Smith RS 《Science (New York, N.Y.)》2012,335(6072):1096-1099

Although genetic control of morphogenesis is well established, elaboration of complex shapes requires changes in the mechanical properties of cells. In plants, the first visible sign of leaf formation is a bulge on the flank of the shoot apical meristem. Bulging results from local relaxation of cell walls, which causes them to yield to internal hydrostatic pressure. By manipulation of tissue tension in combination with quantitative live imaging and finite-element modeling, we found that the slow-growing area at the shoot tip is substantially strain-stiffened compared with surrounding fast-growing tissue. We propose that strain stiffening limits growth, restricts organ bulging, and contributes to the meristem's functional zonation. Thus, mechanical signals are not just passive readouts of gene action but feed back on morphogenesis.  相似文献   

Prevalence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in food-producing animals     

Hiroi M  Yamazaki F  Harada T  Takahashi N  Iida N  Noda Y  Yagi M  Nishio T  Kanda T  Kawamori F  Sugiyama K  Masuda T  Hara-Kudo Y  Ohashi N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(2):189-195

To evaluate the diversity of extended-spectrum β-lactamases (ESBL) genes among food-producing animals, 48 isolates of ESBL-producing Escherichia coli isolates were obtained from rectal samples of broilers, layers, beef cattle and pigs, at the slaughterhouse level. ESBL-carrying E. coli were isolated from 60.0% of individual broiler rectal samples, 5.9% of layers, 12.5% of beef cattle and 3% of pigs. One ESBL-producing Klebsiella pneumoniae was isolated from a broiler. The ESBL-positive E. coli isolates from broilers harbored various ESBL genes: bla (SHV-12), bla(CTX-M-2), bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-44). The plasmid DNAs were analyzed by restriction patterns. Homogeneous band patterns were yielded in those of K. pneumoniae and E. coli isolates harboring the bla(CTX-M-2) gene from different farms. No genetic relation between the 2 CTX-M-14 ESBL-producing strains was found by pulsed-field gel electrophoresis, although 2 plasmids in these strains, obtained from different broiler farms, were similar to each other. This study provides evidence that the proliferation of CTX-M-producing E. coli is due to the growth of indigenous CTX-M-producing strains and the possible emergence of strains that acquired CTX-M genes by horizontal transfer in different broiler farms. CTX-M-producing coliforms in broilers should be controlled due to the critical importance of cephalosporins and the zoonotic potential of ESBL-producing bacteria.  相似文献   

Choroidal melanoma in a dog     

Miwa Y  Matsunaga S  Kato K  Ogawa H  Nakayama H  Tsujimoto S  Sasaki N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(8):821-823

A 7-year-old intact female golden Retriever was referred for evaluation of an intraorbital mass of the left eye. Based on ophthalmoscopy, ultrasonography and magnetic resonance imaging (MRI), the tentative diagnosis was made as an intraocular neoplasia, especially choroidal melanoma. The orbital exenteration of the affected eye was performed. The mass was histologically diagnosed as malignant choroidal melanoma. No signs of recurrence and metastasis were detected by thoracic radiographs, blood examinations and MR images, and the dog was clinically healthy for 23 months after operation.  相似文献   

Usefulness of hemilaminectomy for cervical intervertebral disk disease in small dogs   总被引：1，自引：0，他引：1  

Tanaka H  Nakayama M  Takase K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(7):679-683

Hemilaminectomy was performed to treat cervical disc disease in 18 small dogs. Cervical spinal cord compression was characterized by ventral and/or lateral compression on myelograms. The duration of follow-up examinations ranged from 2 to 72 months. The optimal response time after surgery ranged from 2 days to 3 months. The outcome was determined to be excellent if clinical signs resolved and the dog had completely improved. The outcome was determined to be good if the dog improved, but was not clinically normal or if the degree of the owner's satisfaction was insufficient. Fourteen dogs achieved complete neurologic recovery without complications. One dog was initially neurologically worse after surgery, but ultimately improved to normal neurologic status. These outcomes were judged to be excellent. In the remaining 3 dogs, 2 dogs had relapse of neck pain and one dog remained mildly ataxic. These outcomes were judged to be good. These results suggest that hemilaminectomy is an effective option for surgical treatment of spinal cord compression secondary to cervical disc disease in small dogs.  相似文献   

Ganglioglioma in the thalamus of a puppy     

Uchida K  Nakayama H  Endo Y  Kai C  Tatewaki S  Yamaguchi R  Doi K  Tateyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(1):113-115

A solitary brain mass of a 4-month-old miniature dachshund showing seizure-like neurological signs was examined histopathologically. At necropsy a white tumor mass, replacing the thalamus, approximately 1.5 cm in diameter, was found. There was cystic space filled with yellowish pale fluid in the central area of the tumor mass. Histopathological examination revealed that the mass consisted of irregularly arranged well-differentiated neuronal and glial cells, and multifocal mineral deposits. The neuronal cells had a large clear nucleus and various amount of Nissl substances in the cytoplasm. Some neural cells were bi-nucleated. Neither mitotic figures nor proliferating cell nuclear antigen (PCNA)-positive nuclei was found in the neuronal cells. Immunostaining for glial fibrillary acidic protein (GFAP) revealed diffuse proliferation of GFAP-positive glial cells and their processes, while these glial cells did not show apparent cellular atypism, mitotic activity, or PCNA-immunoreactivity. Accordingly, the present tumor was diagnosed as ganglioglioma, and hamartomatous histogenesis might be possible.  相似文献   

Age-related histological changes in the canine substantia nigra   总被引：2，自引：0，他引：2  

Uchida K  Kihara N  Hashimoto K  Nakayama H  Yamaguchi R  Tateyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):179-185

Age-related changes in the canine substantia nigra, were examined using immunostaining for tyrosine hydroxylase (TH), glial fibrillary acidic protein (GFAP), neurofilament (NF), ubiquitin, single stranded DNA (ssDNA), and alpha-synuclein (alphaSN). Brain sections from 34 necropsied dogs, ranging from 2 months to 18 years old, were used for this study. On general histological examinations, several age-related changes, including lipofuscin deposition, polyglucosan bodies, amorphous basophilic inclusions and eosinophilic crystal inclusions, were found in the aged dogs. Immunohistochemically, TH-positive neurons were located only in the substantia nigra. The number of TH-positive neurons was well preserved in all dogs examined, however, the ratio of TH-positive neurons to GFAP-positive glial cells tended to show slight decrease in aged dogs. By ssDNA immunostaining for apoptotic cells, there were no significant results in the number of ssDNA-positive neurons. The number of ubiquitin- and NF-positive swollen neurites was increased markedly in aged dogs. Ubiquitin immunostaining revealed a small number of basophilic and eosinophilic inclusions, although both types of inclusions were negative for NF. By alphaSN immunostaining, no neurons were immunoreactive and no basophilic or eosinophilic intracytoplasmic inclusions were revealed. These results indicate that in the substantia nigra of aged dogs the dopaminergic neurons are well preserved, but intracytoplasmic inclusions and ubiquitin-positive degenerative neurites are commonly found.  相似文献   

Clinical and clinico-pathologic characteristics of Shiba dogs with a deficiency of lysosomal acid beta-galactosidase: a canine model of human GM1 gangliosidosis     

Yamato O  Masuoka Y  Yonemura M  Hatakeyama A  Satoh H  Kobayashi A  Nakayama M  Asano T  Shoda T  Yamasaki M  Ochiai K  Umemura T  Maede Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):213-217

The present study was conducted to determine the clinical and clinico-pathologic characteristics of Shiba dogs with GM1 gangliosidosis, which is due to an autosomal recessively inherited deficiency of lysosomal acid beta-galactosidase activity. Clinical and clinico-pathological features were investigated in 10 homozygous Shiba dogs with GM1 gangliosidosis. The age at onset was 5 to 6 months and the dogs manifested progressive neurologic signs including loss of balance, intermittent lameness, ataxia, dysmetria and intention tremor of the head. The dogs were unable to stand by 10 months of age due to a progression of ataxia and spasticity in all limbs. Corneal clouding, a visual defect, generalized muscle rigospasticity, emotional disorder and a tendency to be lethargic were observed at 9 to 12 months. The dogs became lethargic from 13 months of age. The survival period seemed to be 14 to 15 months. As a clinico-pathologic feature, lymphocytes with abnormally large vacuoles were observed in peripheral blood (30 to 50% of total lymphocytes) through the lifetime of the dogs. The clinical and clinico-pathologic characteristics of this animal model are useful for not only the development and testing of potential methods of therapy, but also the diagnosis of affected homozygous Shiba dogs in veterinary clinics.  相似文献   

A comparative pathological study on granulomatous meningoencephalomyelitis and central malignant histiocytosis in dogs     

Suzuki M  Uchida K  Morozumi M  Yanai T  Nakayama H  Yamaguchi R  Tateyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(12):1319-1324

Histiocytic proliferative disorders in canine central nervous system (CNS) including granulomatous meningoencephalomyelitis (GME) and malignant histiocytosis were compared pathologically. Lesions of GME mainly existed in the white matter of the cerebrum, brainstem and cerebellum and consisted of characteristic perivascular cuffing, parenchymal granuloma and leptomeningeal infiltrates of mononuclear cells. In malignant histiocytosis, there were two histological patterns, diffuse proliferation of neoplastic histiocytes through the leptomeninges and neoplastic nodule formation in the parenchyma. Neoplastic histiocytes exhibited mild to severe cellular atypia and high ability of invasion into the brain parenchyma. Mitotic and phagocytic figures were also observed. Several histiocytic markers, including lysozyme, alpha1-antitrypsin and lectin RCA-1, revealed histiocytic origin of both inflammatory and neoplastic cells, however, those were not determinative for the discrimination between GME and malignant histiocytosis. CD3- and PCNA-positive cells existed in the lesions of both diseases. The number of CD3-positive cells in GME tended to be greater than in malignant histiocytosis, while the difference was not statistically significant.  相似文献   

TRAIL-decoy receptor 1 plays inhibitory role in apoptosis of granulosa cells from pig ovarian follicles     

Wada S  Manabe N  Nakayama M  Inou N  Matsui T  Miyamoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(5):435-439

Previously, we histochemically examined the localization of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptors in porcine ovarian follicles, and demonstrated a marked reduction in the expression of TRAIL-decoy receptor-1 (DcRI) in granulosa cells of atretic follicles. In the present study, to confirm the inhibitory activity of DcR1 in granulosa cells, granulosa cells prepared from healthy follicles were treated with phosphatidylinositol-specific phospholipase C (PI-PLC) to cleave glycophospholipid anchor of DcR1 and to remove DcR1 from the cell surface, and then incubated with TRAIL. PI-PLC treatment increased the number of apoptotic cells induced by TRAIL. The present finding indicated the possibility that TRAIL and its receptors were involved in induction of apoptosis in granulosa cells during atresia, and that DcR1 plays an inhibitory role in granulosa cell apoptosis.  相似文献   

Effects of chronic oral amiodarone on left ventricular function,ECGs, serum chemistries,and exercise tolerance in healthy dogs     

Bicer S  Nakayama T  Hamlin RL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):247-254

Amiodarone, a class III antiarrhythmic with beta-adrenergic blocking and antimuscarinic properties, has a wide spectrum of clinical use in humans. This study was conducted to establish the effects of a 25 mg/kg q12h loading dose and a 30 mg/kg q24h maintenance dose of amiodarone, each given PO for 3.5 weeks, on systemic arterial pressure, echocardiographic (ECHO) indices of left ventricular function, ECGs, exercise tolerance, and serum biochemistries in adult, clinically normal dogs. Means were calculated and were compared by analysis of variance with repeated measures. When a significant F statistic was identified, specific means were compared by Bonferroni's post hoc test. Body weight and heart rate (HR) decreased, and PQ, QT, and corrected QT (QTc) increased significantly (P < .05) for the weeks that the dogs received the loading dose, but all parameters returned to values the same as those in the pretest for the weeks when dogs received the maintenance dose. Serum activity of hepatic enzyme activities and cholesterol concentrations increased, and serum concentrations of thyroid hormones (triiodothyronine [T3] and thyroxine [T4]), phosphorous, and total carbon dioxide decreased. The changes in PQ, QT, and QTc are similar to those obtained previously, but the detailed ECG and ECHO observations have not been reported. A dose of 25 mg/kg q12h, but not 30 mg/kg q24h, is an appetite suppressant, and the lower dose produces neither ECG nor ECHO changes of clinical or toxicological significance in normal dogs.  相似文献