Preliminary experiments on mechanical stretch-induced activation of skeletal muscle satellite cells in vivo     

Tomowa SAKATA  Ryuichi TATSUMI  Michiko YAMADA  Sei-Ichi SHIRATSUCHI  Shinpei OKAMOTO  Wataru MIZUNOYA  Akihito HATTORI  Yoshihide IKEUCHI 《Animal Science Journal》2006,77(5):518-525

We have shown in vitro that mechanical stretch triggers activation of quiescent satellite cells of skeletal muscle to enter the cell cycle through an intracellular cascade of events including nitric oxide (NO) synthesis that results in the release of hepatocyte growth factor (HGF) from its extracellular association and its subsequent presentation to signaling receptors. In order to explore the activation mechanism in vivo, stretch experiments were conducted in the living animal using our suspension model developed. This system used the weight of the hind portion of rats to stretch the inside muscles of the left hind limb suspended for a period of 0.5–2.0 h. At the end of the stretch period, the rats received an intraperitoneal injection of bromodeoxyuridine followed by immunocytochemistry for its incorporation as an index of satellite cell activation in vivo. Depending on the period of stretch, bromodeoxyuridine labeling was increased significantly over the contralateral unstretched leg or control muscle from untreated rats. A stretched muscle extract prepared from the 2 h stretched tissue by incubating it in PBS, showed the active form of HGF as revealed by immunoblotting and it could stimulate the activation of unstretched satellite cells. Also, administering NO synthase inhibitor L‐NAME prior to muscle stretch abolished the stretch activation of satellite cells. Therefore, the results from these experiments demonstrate that stretching muscle triggers NO synthesis and HGF release, which could activate satellite cells in vivo.  相似文献   

Recreational tree-climbing programs in a rural Japanese community forest: Social impacts and “fun factors”     

John Gathright  Yozo Yamada  Miyako Morita 《Urban Forestry & Urban Greening》2007,6(3):169-179

We examined whether recreational tree climbing (TC) activities would have positive social impacts and rejuvenate an outdoor activity center and surrounding community forest in central Japan. Our case study comprised 3800 adults and children participating in TC activities at the Jyokoji Outdoor Activity Center (JOAC) in Seto, Japan. We focused on 1393 adult participants whom we considered to be the decision makers regarding family recreation, and we explored both the social impacts of TC and various factors that contributed to and distracted from the overall experience. Qualitative and quantitative data indicated that elements such as age, gender, tree preferences, tree appreciation, tree education, and technical instruction influenced the enjoyment of recreational TC and the positive effects on tree climbers. Overall, the climbing program had positive social impacts for the community forest and contributed to local conservation initiatives. Our case study suggests that other areas can benefit from incorporating TC programs into community forest planning to complement aesthetic, ecological, and restoration benefits and provide a new venue for recreation and conservation awareness.  相似文献   

Calcium ion promotes successful penetration of powdery mildew fungi into barley cells     

Issei Kobayashi  Masako Yamada  Yuhko Kobayashi 《Journal of General Plant Pathology》2007,73(6):399-404

To determine whether Ca²⁺ promotes powdery mildew penetration, Ca²⁺-treated barley coleoptiles were inoculated with conidia of pathogenic and nonpathogenic fungi. Penetration efficiency of the pathogenic powdery mildew Blumeria graminis was enhanced by Ca²⁺ treatment, but that of the necrotrophic pathogen Helminthosporium sp. remained unaffected. Similarly, when actin-dependent penetration resistance is suppressed with cytochalasin A, Ca²⁺ treatment specifically enhanced penetration of the nonpathogenic powdery mildew Erysiphe pisi but not that of other nonpathogens. Calmodulin inhibitors suppressed the promotive effect of Ca²⁺ on B. graminis penetration. These results suggest that barley powdery mildew specifically requires Ca²⁺ and calmodulin for penetration.  相似文献   

Histochemistry of Complex Carbohydrate in the Major Salivary Glands of Hoary Bamboo Rats (Rhizomys purinosus)     

J. Kimura  I. Habata  H. Endo  W. Rerkamnuaychoke  M. Kurohmaru  J. Yamada  T. Nishida  A. Tsukise 《Anatomia, histologia, embryologia》1998,27(3):147-153

The major salivary glands (parotid glands, monostomatic sublingual glands and submandibular glands) were obtained from hoary bamboo rats (Rhizomys purinosus) and fixed in Bouin's solution. Paraffin sections were subjected to a battery of staining methods including lectin staining for demonstration of complex carbohydrates. Among the three major salivary glands, unique histochemical features were observed in the submandibular gland. Different from most myomorpha species, submandibular glands of the hoary bamboo rats have two types of secretory cells in the secretory endpieces. One type of cells showed positive reactions with Alcian blue (AB)(pH2.5), periodic acid-Schiff (PAS) and some lectins (peanuts agglutinin, Griffonia simplicifolia I. Machura pomifera agglutinin). The granular ducts, which exist in animals belonging to suborder myomorpha, were not observed in the submandibular glands of this animal.  相似文献   

Immunohistochemical Colocalization of Serotonin, Substance P and Met-enkephalin-Arg⁶-Gly⁷-Leu⁸ in the Endocrine Cells of the Ruminant Duodenum     

T. Mimoda  N. Kitamura  E. Hondo  J. Yamada 《Anatomia, histologia, embryologia》1998,27(1):65-69

The duodenum of various ruminants was examined by immunohistochetnical staining for serotonin, substance P and Metenkephalin-Arg⁶-Gly⁷-Leu⁸ (MENK8). Serotonin- and substance P-immunoreactive endocrine cells were detected in samples from cow, calf, sheep, goat, and barbary sheep. MENK8-immunoreactive endocrine cells were detected exclusively in samples from cow and calf. Substance P and MENK8 immunoreactivity was found in serotonin-immunoreactive endocrine cells of cattle. Substance P- and MENK8-immunoreactive nervous elements were detected in all ruminants examined. The present results suggest that the expression and/or the mechanism that controls the expression of each peptide might differ between endocrine cells and nerve cells and might also depend on animal species.  相似文献   

Histologic and immunocytochemical study of endocrine cells in the gastrointestinal tract of the cow and calf   总被引：3，自引：0，他引：3  

N Kitamura  J Yamada  N Y Calingasan  T Yamashita 《American journal of veterinary research》1985,46(6):1381-1386

The regional distribution and relative frequency of argyrophil cells, and of cells immunoreactive for 5-hydroxytryptamine (5-HT), substance P (SP), somatostatin, glicentin, glucagon, bovine pancreatic polypeptide (BPP), gastrin, leucine-enkephalin, gastric inhibitory polypeptide (GIP), cholecystokinin, secretin, motilin, and neurotensin were studied in 9 segments from the gastrointestinal tract of cows (greater than 1 year old) and calves (less than 3 months old). Argyrophil cells, 5-HT-immunoreactive cells, and somatostatin-immunoreactive cells were distributed throughout the gastrointestinal tract, whereas the other immunoreactive cells were more restricted in distribution. Most endocrine cells were more numerous in the calf than in the cow. This feature was most conspicuous in the abomasum. In the abomasum, argyrophil cells in the cow and calf and 5-HT-immunoreactive cells in the calf were found predominantly in the fundic region, whereas somatostatin-immunoreactive cells and gastrin-immunoreactive cells in the cow and calf and 5-HT-immunoreactive cells in the cow were most numerous in the pyloric region. Substance P-, glucagon-, BPP-, and leucine-enkephalin-immunoreactive cells were rarely detected. In the small intestine, argyrophil cells, 5-HT-, SP-, somatostatin-, gastrin-, GIP-, cholecystokinin-, secretin-, and motilin-immunoreactive cells were most numerous in the duodenum. Neurotensin-, glicentin-, glucagon-, and BPP-immunoreactive cells were detected with the highest frequency in the ileum. In the large intestine, argyrophil cells and 5-HT-, glicentin-, BPP-, somatostatin-, glucagon-, and SP-immunoreactive cells occurred with the highest frequency in the rectum.  相似文献   

Medication control of flunixin in racing horses: Possible detection times using Monte Carlo simulations     

Taisuke Kuroda  Yohei Minamijima  Motoi Nomura  Shozo Yamashita  Masayuki Yamada  Shunichi Nagata  Hiroshi Mita  Norihisa Tamura  Kentaro Fukuda  Atsutoshi Kuwano  Kanichi Kusano  Pierre-Louis Toutain  Fumio Sato 《Equine veterinary journal》2022,54(5):979-988

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Protective effect of floor cover against soil erosion on steep slopes forested with <Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis> (hinoki) and other species     

S. Miura  S. Yoshinaga  T. Yamada 《Journal of Forest Research》2003,8(1):0027-0035

 We evaluated the protective effects of floor cover against soil erosion in three types of forest located on steep slopes under a humid climate: 22- and 34-year-old Chamaecyparis obtusa (hinoki), 34-year-old Cryptomeria japonica (sugi), and 62-year-old Pinus densiflora (red pine) stands. We measured sediment transport rates (sediment mass passing through one meter of contour width per millimeter of rainfall), using sediment traps, before and after removing floor cover. Raindrop splash erosion was dominant in the experimental stands. Floor cover percentage (FCP) during the preremoval stage varied from 50% to 100% among the four stands, and sediment transport rates ranged from 0.0079 to 1.7 g m⁻¹ mm⁻¹. The rates increased to 1.5–5.6 g m⁻¹ mm⁻¹ immediately after removing floor cover, and remained high throughout the experiment. The presence of physical cover near the ground has a crucial effect on sediment transport on forested slopes. The protective effect ratio (the ratio of the sediment transport rate in a control plot to that in the removal plot) in a young hinoki stand, in which the FCP decreased markedly, was 0.3 at most, which is close to the rate for bare ground. The protective effect ratio in the red pine stand was ≤0.003. We concluded that the protective effect of floor cover in undisturbed forests in Japan differs by over two orders of magnitude, based on comparisons with previous studies. Received: March 11, 2002 / Accepted: August 16, 2002 Present address: Department of Forest Site Environment, Forestry and Forest Products Research Institute, Ibaraki 305-8687 Japan Tel. +81-298-73-3211; Fax +81-298-74-3720 e-mail: miura@affrc.go.jp Present address: Department of Forest Site Environment, Forestry and Forest Products Research Institute, Ibaraki 305-8687 Japan Tel. +81-298-73-3211; Fax +81-298-74-3720 e-mail: miura@affrc.go.jp Acknowledgments This study was supported by the Research Council of the Ministry of Agriculture, Forestry, and Fisheries, of Japan. We thank H. Ujihara, S. Ujihara, and M. Ogasawara in Otoyo, Kochi, who provided the experimental stands used in this study. We also thank K. Hirai, S. Kuramoto, E. Kodani, and the rest of the staff at the Shikoku Research Center, Forestry and Forest Products Research Institute, for their help in conducting the experiments. Correspondence to:S. Miura  相似文献   

Characterization of the products resulting from ethylene glycol liquefaction of cellulose   总被引：9，自引：0，他引：9  

Tatsuhiko Yamada  Hirokuni Ono 《Journal of Wood Science》2001,47(6):458-464

The composition of liquefied cellulose in the presence of ethylene glycol (EG) was studied. The liquefied products were fractionated and analyzed with highperformance liquid chromatography and nuclear magnetic resonance. EG-glucosides were detected as the only saccharides and 2-hydroxyethyl levulinate as the highly decomposed compound derived from cellulose. Quantitative analysis of the EG-glucosides and levulinic acid that comes from the levulinate shows the presence of the following mechanism in the EG-liquefaction of cellulose. First, cellulose is degraded and produces considerable amounts of EG-glucosides during the early stage of liquefaction. Then, when liquefaction is prolonged, the glucosides are decomposed, leading to a large quantity of levulinates.  相似文献   

Absolute configuration of arylglycerol-β-aryl ethers obtained by asymmetric reduction of the correspondingα-ketonic compound with intactFusarium solani cells     

Takeshi Katayama  Jyoji Tsutsui  Kazuo Tsueda  Takao Miki  Yasuhiro Yamada  Murao Sogo 《Journal of Wood Science》2000,46(6):458-465

When (±)--oxo-guaiacylglycerol--(vanillic acid) ether (1) is degraded byFusarium solani M-13-1, the-ketone is initially reduced to giveerythro andthreo guaiacylglycerol--(vanillic acid) ethers (2), arylglycerol--aryl ethers, both of which are enantiomerically pure. The absolute configuration in each2 was determined by Mosher's method; the products were converted to,-di-(R)--methoxy--trifluoromethylphenylacetates (MTPA esters) (3) oferythro (-)- andthreo (+)-veratrylglycerol--(methyl vanillate) ethers (3), whose¹H nuclear magnetic resonance (NMR) spectra were examined and compared with those of four di-(R)-MTPA ester (3) diastereomers from chemically synthesizederythro (±)-3 andthreo (±)-3. To assign the- and-MTPA-OCH₃ peaks, the¹H NMR scans of several compounds that have substructures of 3 and their 3,4,5-trimethoxyphenyl analogues were examined. When a racemic alcohol reacts with (R)-MTPA to give a pair of (R)-MTPA ester diastereomers, the value was defined as the absolute value of the difference in the¹H chemical shifts of the peak between the diastereomers. It was found that the values of-MTPA-OCH₃ were larger than those of-MTPA-OCH₃ owing to a shielding effect of the veratryl ring located on the-MTPA-OCH₃, and that the-MTPA-OCH₃ peaks in the 3,4,5-trimethoxyphenyl compounds shifted downfield relative to those in the veratryl compounds. On the basis of the¹h NMR data of (R)-MTPA esters, the absolute configuration of the four chemically prepared diastereomers (3) were determined. The catabolicerythro 3 [fromerythro (-)-3] andthreo 3 [fromthreo (+)-3] were identical to (R, S, R)-erythro 3 and (R, S, S)- threo 3, respectively. An hydrogen species in the fungal reduction would attack the-ketone fromre-face of both (R)-1 and (S)-1, givingerythro (S, R)-2 andthreo (S, S)-2, respectively.Part of this paper was presented at the 33rd Lignin Symposium, Tsukuba, November 1988  相似文献