Production of transparent exopolymer particles by four diatom species     

Tsuyoshi Fukao  Katsunori Kimoto  Yuichi Kotani 《Fisheries Science》2010,76(5):755-760

The production of transparent exopolymer particles (TEP) by four diatoms, Coscinodiscus granii, Eucampia zodiacus, Rhizosolenia setigera, and Skeletonema sp., was examined. Most of the TEP in C. granii (74% of the maximum) were produced during the growth phase. In contrast, most of the TEP in E. zodiacus (73%), R. setigera (74%), and Skeletonema sp. (70%) were produced during the stationary and declining phases. The C. granii TEP production rate was highest in the growth phase, whereas those in E. zodiacus, R. setigera, and Skeletonema sp. were highest in the stationary–decline phase. The TEP concentrations per cell and the cell volume of C. granii were 34.97 ± 4.114 (mean ± SD) ng Xeq./cell (xanthan gum equivalents per cell) and 341.6 ± 56.33 fg Xeq./μm³, and were 23.01 and 4.32 times higher than the values obtained from the other three diatoms, respectively. The results suggest that the mechanisms of TEP production differ with growth stage and diatom species. Therefore, it is likely that the differences in TEP production among the diatom species influence the complexity of TEP dynamics in aquatic environments.  相似文献   

Ultrasonographic observations of experimental traumatic reticuloperitonitis in cattle     

T Kurosawa  K Yagisawa  K Yamaguchi  K Takahashi  T Kotani  Y Ando  M Sonoda 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(1):143-145

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Electroretinography using contact lens electrode with built-in light source in dogs     

Maehara S  Itoh N  Itoh Y  Wakaiki S  Tsuzuki K  Seno T  Kushiro T  Yamashita K  Izumisawa Y  Kotani T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(5):509-514

Electroretinography (ERG) is an effective method for the diagnosis of retinal disease. In the dog, dependable ERG recording is difficult without the use of an expensive device like a Ganzfeld full-field stimulator. The International Society for Clinical Electrophysiology of Vision has defined the standard flash stimulus condition (SF) and evaluation of the retina using the b/a ratio in humans. In dogs, evaluation using the b/a ratio has not been reported, whereas the intensity of SF has been defined. In this study, we performed a convenient ERG recording method using a contact lens electrode with a built-in light source (LED-electrode), and confirmed SF as reported previously. ERG recordings were performed on 15 healthy beagle dogs under sedation. We performed bilateral ERG at 12 different intensities after 30 min dark adaptation. After 10 min light adaptation, we recorded single flash cone and flicker cone response using the SF determined in this study. In this study, SF of 3.0 cd/m(2)/sec (6,000 cd/m(2), 0.5 msec) resulted in b/a=2. The intensity for rod response that recorded only the b-wave was 0.0096 cd/m(2)/sec (80 cd/m(2), 0.12 msec). We could achieve ERG for each response easily and smoothly under sedation, and without general anesthesia. Using an LED-electrode, we could perform more quantitative and reproducible ERG examinations than with traditional methods. We propose that the b/a ratio is the most useful parameter in ERG reporting for evaluating retinal function.  相似文献   

Morphologic changes of the anterior corneal epithelium caused by third eyelid removal in dogs     

Saito A  Watanabe Y  Kotani T 《Veterinary ophthalmology》2004,7(2):113-119

Morphologic changes of corneal epithelium after third eyelid removal were observed in six normal Beagle dogs. The observation was conducted on the 17th, 35th and 72nd week after the removal. Morphologic changes were observed on corneal epithelium layers at 17 and 35 weeks post excision of the third eyelid but they were limited to minor changes including abnormal intercellular adhesion and further exfoliation of superficial cells at 72 weeks. The reduced BUT and evidence of vital positive staining correspond with these morphologic changes. Therefore, these changes are thought to be important findings from a morphologic view point in identifying pathologic symptoms of the cornea using clinical evaluation methods such as BUT and vital staining method. Grossly, no clinical indication of ocular disease was indicated by slit-lamp biomicroscopic observation; however, the BUT shortage and positive finding of vital staining indicated that the corneal epithelium layers after third eyelid removal lacked the essential barrier function. Thus, it would seem appropriate to consider that such a condition of the ocular surface would worsen with excessive exposure of the ocular surface, palpebration disorders and other exogenous factors.  相似文献   

Kinetics of lymphocytic subsets in chicken tracheal lesions infected with infectious bronchitis virus   总被引：2，自引：0，他引：2  

Kotani T  Wada S  Tsukamoto Y  Kuwamura M  Yamate J  Sakuma S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(4):397-401

The kinetics of T-cells (CD3 positive (+), CD4+ and CD8+ cells) and B-cells (IgG+, IgM+ and IgA+ cells) in chicken trachea were studied immunohistochemically and histopathologically following an intratracheal inoculation of infectious bronchitis virus (IBV). Viral antigen was detected in the cytoplasm of tracheal epithelium from 16 hr to 6 days post-inoculation (p.i.) with a peak on 4 days p.i. A few IgG+, IgM+ and IgA+ cells were detected in the submucosa from 8 hr p.i. Thereafter IgG+ and IgM+ cells were gradually increased in number, and dramatically increased from 3 days p.i., peaked on 4 days p.i., and gradually decreased after 5 days p.i. IgA+ cells were detected in a small number than IgG+ and IgM+ cells during the all experimental period. These B cells mainly existed in the lamina propria, and some cells were recognized in the interepithelial space. After 14 days p.i., small number of IgG+ and IgM+ cells were detected in the germinal center of lymph follicles in the lamina propria. From 24 to 60 hr p.i., a few number of CD3+, CD4+ and CD8+ cells were detected at the perivascular area in the lamina propria. After 3 or 4 days p.i., each positive T-cells increased rapidly in number, and reached on the peak at 5 days p.i. CD3+, CD4+ and CD8+ cells tend to distribute diffusely, perivascular area, and surrounding area of CD4+ cells, respectively. CD4+ cells were dramatically decreased from 7 days p.i., and CD3+ and CD8+ cells were decreased from 14 days p.i. No T-cells were detected in the lymph follicles in the lamina propria.  相似文献   

Replication of porcine cytomegalovirus in the 19-PFT cell line.     

H Kawamura  T Tajima  T Hironao  T Kajikawa  T Kotani 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(6):1209-1211

Replication of porcine cytomegalovirus was examined in fibroblast- and epithelial-like cell lines of the 19-PFT cell line derived from pig fallopian tube. The virus grew well in the fibroblast-like cell line than the epithelial-like cell line. Cytomegalic cytopathic effects of the virus were clearly observed under the microscope after dispersion of the infected cell culture by trypsin-versene and it was demonstrated that cytomegalic cytopathic effects could be used for infectivity titration. Intranuclear inclusions were formed in the infected cells and herpetic virus particles were observed in the nucleus and cytoplasm when infected cells were observed under the transmission electron microscope. Infected cells formed characteristic red plaque.  相似文献   

Method for underwater measurement of the auditory brainstem response of fish   总被引：1，自引：0，他引：1  

Tomohiro?SugaEmail author  Tomonari?Akamatsu  Ryo?Kawabe  Tomonori?Hiraishi  Katsutarou?Yamamoto 《Fisheries Science》2005,71(5):1115-1119

ABSTRACT:   The auditory brainstem response (ABR) of fishes is commonly measured by bringing the heads of the fishes out of the water in a small tank. However, this method is inapplicable to experiments for large fishes that are economically important in large spaces such as the sea or in a large tank. This paper describes a method of recording, the ABR for fishes in water, without exposing the fish heads to air, by using a waterproof, insulated electrode. To evaluate the effectiveness of this method, the goldfish Carassius auratus was investigated, and the ABR waveform and auditory thresholds measured in water were compared with those measured on the surface. Both ABR waveforms and auditory thresholds showed similar trends between the two methods. The underwater ABR method is useful to measure the auditory thresholds of larger fish in natural or on-site environments such as the sea, net enclosures and large aquaria in which precise positioning of the fish is not possible. However, more improvement is needed to apply this method to large fishes.  相似文献   

Maturational factors as indicators of egg quality in Japanese eel, Anguilla japonica     

D.H. Shin  H. Matsubara  S. Kaneko  T. Kotani  M. Yamashita  S. Adachi  K. Yamauchi 《Fish physiology and biochemistry》2003,28(1-4):519-520

In order to identify maturational factors that can serve as indicators of egg quality in artificially matured Japanese eel, Anguilla japonica, maturation-promoting factor (MPF; consists of cdc2 and cyclin B) related proteins and chromosomes were examined. Mitogen-activated protein kinase (MAPK; 44 kDa band) and cdc2 (35 kDa and 34 kDa band) were detected. Chromosomes aligned on a vertical spindle appeared normal; however, chromosomes on a horizontal spindle and dispersed chromosomes seemed unusual.  相似文献   

Coastal development threatens Datan area supporting greatest fish diversity at Taoyuan Algal Reef,northwestern Taiwan     

Joseph Heard  Wei-Chen Tung  Yu-De Pei  Tzu-Hao Lin  Chien-Hsiang Lin  Tomonari Akamatsu  Colin K. C. Wen 《水产资源保护:海洋与淡水生态系统》2021,31(3):590-604

1. Taoyuan Algal Reef is a biodiverse coralline algal reef in north-west Taiwan, that is currently threatened by coastal development and industrial waste runoff.
2. As the reef lies in an exposed area that is frequently disturbed by monsoons, it is difficult to survey using traditional methods. Knowledge of the reef is therefore limited, and has until recently, long been regarded as a barren environment.
3. However, recent studies have revealed that the reef is inhabited by a diverse array of organisms, particularly at Datan, where a natural gas receiving terminal is planned for construction. Due to challenging environmental conditions, otolith assemblage and soundscape analyses were used to supplement traditional sampling methods including clove oil, netting, and pole-and-line fishing in order to assess the diversity of the fish community at Taoyuan Algal Reef.
4. Several fish species that had not been recorded by previous surveys were observed. Fish diversity and the average size of commercially targeted species were greatest at Datan G2. Predatory reef fishes such as groupers (Serranidae) and snappers (Lutjanidae), as well as several small endangered scalloped hammerhead sharks Sphyrna lewini were recorded at G2, where otolith assemblage analysis also indicated increased predatory activity. However, fewer individuals and species were recorded from tidal pools across all sites compared to previous surveys, suggesting a loss of biodiversity.
5. If construction work resumes at Datan, it will be likely to have adverse consequences for the reef itself, the species that inhabit it, and by extension, the local fishermen that rely upon it. Halting additional coastal development, reducing industrial and domestic pollution, as well as improving the management of traditional fisheries is recommended to protect this unique reef ecosystem from further degradation.

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Availability of a Microglia and Macrophage Marker,Iba-1, for Differential Diagnosis of Spontaneous Malignant Reticuloses from Astrocytomas in Rats     

Ryuichi Nakamura  Tomonari Nishimura  Taehito Ochiai  Satomi Nakada  Mariko Nagatani  Hiroyuki Ogasawara 《Journal of toxicologic pathology》2013,26(1):55-60

In rats, it is sometimes difficult to distinguish malignant reticuloses from astrocytomas in routine histopathological assessment. In the present study, four spontaneous brain neoplasms developing in the cerebrum of one Wistar Hannover rat and three Sprague-Dawley rats were immunohistochemically examined using microglia and macrophage markers. Histopathologically, these neoplasms were localized mainly in the cerebral cortex, hypothalamus or piriform lobe, and the portions showing solid growth did not show characteristic cellular arrangement but had an indistinct boundary with the surrounding brain parenchyma. Neoplastic cells had oval or pleomorphic small nuclei with abundant eosinophilic cytoplasm. Two cases showed neoplastic cell infiltration into the meninges and perivascular spaces. Silver staining showed lack of reticulin fiber production in the stroma of the neoplasms. Immunohistochemically, the neoplastic cells were strongly positive for Iba-1 and sporadically positive for CD68 in all four cases. On the basis of these results, all the neoplasms examined here could be distinguished from astrocytomas and diagnosed as malignant reticuloses. Thus, immunohistochemical demonstration of microglia/macrophage characters, such as using Iba-1, is considered to be helpful for differential diagnosis of malignant reticuloses from astrocytomas among spontaneously occurring primary brain neoplasms in rats.  相似文献