Quantitative structure-activity studies of substituted benzyl chrysanthemates: 7. Relationship between induction of repetitive discharges and effects on the action potential     

Masato Omatsu  Keiichiro Nishimura  Toshio Fujita 《Pesticide biochemistry and physiology》1985,24(2):192-199

The effects of substituted benzyl (1R)-trans-chrysanthemates and related compounds on the action potential of the crayfish giant axon were investigated using an intracellular microelectrode. The effects are broadly classified into three types: deceleration of the falling-phase of the action potential (type A), elevation of the depolarizing after-potential (type B), and the combination type (type C). The potency of the type A compounds to decelerate the rate of the falling-phase was determined in terms of the concentration required for reducing the rate to a specified degree. This potency was shown to correlate with the potency to induce repetitive discharges in the cockroach central nerve cord in terms of minimum effective concentration, which was determined previously. The potency of the types B and C compounds to elevate the after-potential was, however, not related directly with the cockroach nerve repetitive activity. The elevation of the after-potential is one of the critical factors but other effects such as a depolarization of the resting potential may be involved in determining the repetitive activity.  相似文献   

The effect of additional arginine in the high defatted soybean meal diet on the growth of giant gouramy Osphronemus gouramy Lac.     

M. Agus Suprayudi  Toshio Takeuchi  Ing Mokoginta and  Atri T. Kartikasari 《Fisheries Science》2000,66(5):807-811

  相似文献   

Metabolism of fenitrothion by organophosphorus-resistant and -susceptible house flies, Musca domestica L     

Masashi Ugaki  Toshio Shono  Jun-ichi Fukami 《Pesticide biochemistry and physiology》1985,23(1):33-40

The metabolism of fenitrothion was investigated in highly resistant (Akita-f) and susceptible (SRS) strains of the house fly, Musca domestica L. The Akita-f strain was 3500 times more resistant to fenitrothion than the SRS strain. Fenitrothion, topically applied to the flies, was metabolized in vivo far faster in the Akita-f strain than in the SRS strain. In vitro studies revealed that fenitrothion was metabolized by a cytochrome P-450-dependent monooxygenase system and glutathione S-transferases. The former oxidase system metabolized fenitrothion in vitro into fenitrooxon and 3-methyl-4-nitrophenol as major metabolites, and into 3-hydroxymethyl-fenitrothion and 3-hydroxymethyl-fenitrooxon as minor metabolites. Glutathione S-transferases metabolized fenitrothion into desmethylfenitrothion. The cytochrome P-450-dependent monooxygenase system and glutathione S-transferases of the resistant Akita-f strain had 1.4 to 2.2 times and 9.7 times, respectively, as great activities as those of the susceptible SRS strain. These results suggest the importance of glutathione S-transferases in fenitrothion resistance in the Akita-f strain.  相似文献   

Mangrove Habitat Formation and Response to Holocene Sea-level Changes on Kosrae Island,Micronesia     

Fujimoto  Kiyoshi  Miyagi  Toyohiko  Kikuchi  Takao  Kawana  Toshio 《Mangroves and Salt Marshes》1996,1(1):47-57

Mangrove habitats on Kosrae are divided into three types, i.e., an estuary or delta type, a backmarsh or lagoon type and a coral reef or tidal-flat type. Most of the mangrove forests of Kosrae have been developed during the last 2000 years by accumulating mangrove peat with the gradual sea-level rise of 1 to 2 mm/yr except the landward part of the estuary or delta type. On the other hand, during the period of rapid sea-level rise of about 10 mm/yr between 4100 and 3700 yr B.P., the mangrove forests ceased peat accumulation and retreated landward. Until 3500 yr B.P., mangrove forests were distributed only in narrow bands in the inlets. Therefore, the critical rate of mangrove peat accretion with sea-level rise is estimated at more than 2 mm/yr and less than 10 mm/yr. If the anticipated sea-level rise exceeds this critical rate, all of the mangrove forests of Kosrae will retreat landward and reduce rapidly.  相似文献   

Energy and carbon dioxide (CO2) balance of logging residues as alternative energy resources: system analysis based on the method of a life cycle inventory (LCI) analysis   总被引：1，自引：0，他引：1  

Takuyuki Yoshioka  Kazuhiro Aruga  Toshio Nitami  Hiroshi Kobayashi  Hideo Sakai 《Journal of Forest Research》2005,10(2):125-134

Using the method of a life cycle inventory (LCI) analysis, the energy balance and the carbon dioxide (CO₂) emission of logging residues from Japanese conventional forestry as alternative energy resources were analyzed over the entire life cycle of the residues. The fuel consumption for forestry machines was measured in field experiments for harvesting and transporting logging residues at forestry operating sites in Japan. In addition, a total audit of energy consumption was undertaken. It involved an assessment of materials, construction, and the repair and maintenance of forestry machines as well as the costs associated with an energy-conversion plant. As a result, the ratio of energy output to input was calculated to be 5.69, indicating that the system examined in this study could be feasible as an energy production system. The CO₂ emission per MWh_e (e: electricity) of the biomass-fired power generation plant was calculated to be 61.8kgCO₂/MWh_e, while that of coal-fired power generation plants in Japan is 960kgCO₂/MWh_e. Therefore, the reduction in the amount of CO₂ emission that would result from replacing coal with biomass for power generation by as much as 3.0 million dry-t/year of logging residues in Japan was estimated to be 1.66 million tCO₂/year, corresponding to 0.142% of the national CO₂ emission. This study provides evidence that Japan could reduce its domestic CO₂ emission by using logging residues as alternative energy resources.  相似文献   

Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats     

Haney SAMIR  Kazuaki SASAKI  Eman AHMED  Aly KAREN  Kentaro NAGAOKA  Mohamed EL SAYED  Kazuyoshi TAYA  Gen WATANABE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):549-556

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.  相似文献   

Effects of food enriched with egg yolk hydrolysate (bone peptide) on bone metabolism in orchidectomized dogs     

Toyokazu KOBAYASHI  Hiroshi KOIE  Arisa WATANABE  Arisa INO  Kazuya WATABE  Mujo KIM  Kiichi KANAYAMA  Kazuya OTSUJI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(4):503-506

We examined the effects of chicken egg hydrolysate (also known as “bone peptide” or BP) on bone metabolism in 5- to 8-month-old orchidectomized dogs. The bone formation marker serum bone alkaline phosphatase (BAP) and the bone resorption marker urine deoxypyridinoline (DPD) were used as indicators to measure changes in bone metabolism. The following results were observed that Serum BAP was higher in dogs fed BP-enriched food throughout the clinical investigation. Serum BAP was statistically significantly higher in dogs fed BP-enriched food than in dogs fed non-BP-enriched food at 2 months after orchidectomy. This suggests that BP promoted bone formation immediately after orchidectomy.  相似文献   

Detecting endotoxin activity in bovine serum using an automated testing system     

Kazuyuki SUZUKI  Toshio SHIMAMORI  Ayano SATO  Kenji TSUKANO  Masakazu TSUCHIYA  Jeffrey LAKRITZ 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(8):977-979

The aim of the present study was to compare the ability of the commercially available portable test system (PTS^TM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assays. The results using PTS^TM correlated with those using KT (r²=0.963, P<0.001) or KC assays (r²=0.982, P<0.001). Based on these findings, the PTS^TM could be applied as a simplified system to assess endotoxin activity in bovine serum.  相似文献   

Effect of ovarian hormones on maturation of dendritic cells from peripheral blood monocytes in dogs     

Viskam WIJEWARDANA  Kikuya SUGIURA  Daluthgamage Patsy H. WIJESEKERA  Shingo HATOYA  Toshiya NISHIMURA  Ryoji KANEGI  Takahiro USHIGUSA  Toshio INABA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):771-775

Previously, we reported that ovarian hormones affect the immune response against E. coli isolated from the dogs affected with pyometra. In order to investigate mechanisms underlying the immune modulation, we examined the effects of ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC differentiation, progesterone significantly decreased the expression of DC maturation markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen to the cultures increased the expression of CD86, but not other maturation makers. Furthermore, DCs differentiated in the presence of progesterone did not stimulate allogeneic mononuclear cells in PB. Taken together, these results indicate that progesterone diminishes the maturation of DCs, leading to decreased immune responses against invading pathogens.  相似文献   

Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations     

Yojiro YANAGAWA  Yukiko MATSUURA  Masatsugu SUZUKI  Shin-ichi SAGA  Hideto OKUYAMA  Daisuke FUKUI  Gen BANDO  Masashi NAGANO  Seiji KATAGIRI  Yoshiyuki TAKAHASHI  Toshio TSUBOTA 《The Journal of reproduction and development》2015,61(1):61-66

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17β and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17β, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17β after copulation.  相似文献