Influence of motor activities on the release of transmitter quanta from motor nerve terminals in mice.     

Y Taquahashi  K Yonezawa  M Nishimura 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(5):513-516

We investigated the effects of motor activities on transmitter release in mouse nerve-muscle preparations of the diaphragm muscle (DPH), extensor digitorum longus muscle (EDL), and soleus muscle (SOL). Mice were divided into a control group, a motor-restricted (RST) group, and a motor-compelled (CMP) group. The quantal content (m) of endplate potentials was measured intracellularly. In DPH the motor activity was unaffected. In the CMP group the m value of the EDL group increased with increases in the cooperativity of Ca2+ in transmitter release. Compared with the CMP group, the SOL of the RST group had a smaller m value with increases in the cooperativity of Ca2+ in transmitter release. These results suggest that motor activities can influence neuromuscular activity specific to different systems, however, the motor compulsion specifically activated the function of EDL and the motor restriction activated the function of SOL, and these effects might lead to altered activity of the release of transmitter quanta in motor nerve terminals of mice.  相似文献   

1,25-Dihydroxyvitamin D3, recombinant human transforming growth factor-beta 1, and recombinant human bone morphogenetic protein-2 induce in vitro differentiation of canine osteosarcoma cells.   总被引：2，自引：0，他引：2  

K Nozaki  T Kadosawa  R Nishimura  M Mochizuki  K Takahashi  N Sasaki 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(6):649-656

Effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), recombinant human transforming growth factor (rhTGF)-beta 1 and recombinant human bone morphogenetic protein (rhBMP)-2 on differentiation in four different canine osteosarcoma cell lines (POS53B, 53C, 53D and 14A) were examined using markers specifically expressed by phenotypic osteoblasts. 1,25(OH)2D3 increased alkaline phosphatase (ALP) activity in one cell line, osteocalcin production in two lines and type I collagen production in three lines. RhTGF-beta 1 increased ALP activity in one clonal cell, osteocalcin production in one clonal cell and type I collagen production in two clonal cells. RhBMP-2 increased ALP activity in all clonal cells, osteocalcin production in two clonal cells and type I collagen production in three clonal cells. Thus, these agents induced differentiation in osteosarcoma cells at different efficacies. Electron microscopic study revealed that these agents increased cellular activity in all cell lines with no evidence of degeneration of cell organelle by drug cytotoxicity. In some cultures treated with either 1,25(OH)2D3 or rhBMP-2, apoptotic cells were observed. Based on the change in markers, rhBMP-2 and 1,25(OH)2D3 seemed to be more effective than rhTGF-beta 1. These agents are potential inducers of apoptosis.  相似文献   

Cadmium-binding protein in tissues of male rats and Japanese quail.     

M Nishimura  H Tanaka  N Urakawa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1976,38(6):619-628

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Quantitative structure-activity studies of substituted benzyl chrysanthemates: 2. Physicochemical substituent effects and neurophysiological and symptomatic activities against American cockroaches     

Shoji Nakagawa  Nobuyuki Okajima  Keiichiro Nishimura  Toshio Fujita  Minoru Nakajima 《Pesticide biochemistry and physiology》1982,17(3):259-270

The substituent effects on the symptomatic and neurophysiological activities of a number of substituted benzyl (1R)-trans-chrysanthemates against American cockroaches were quantitatively analyzed using electronic, hydrophobic, and steric parameters. The effects were shown to be highly specific to substituent positions except for those on the neuroblocking activity. Steric effect of substituents represented by van der Waals volume was found to play the most significant role in determining the variation in each activity. Peculiar substituent effects depending upon the bulkiness and position of substituents, which had been observed in the toxicity of this class of compounds, can be rationalized by the present analysis indicating that the optimum van der Waals volume of substituents is largest at the ortho and smallest at the para position.  相似文献   

Catabolism of tryptamine by cockroach head enzyme preparation     

Keiichiro Nishimura  Toshio Fujita  Minoru Nakajima 《Pesticide biochemistry and physiology》1975,5(6):557-565

An enzyme preparation from the homogenate of American cockroach heads [Periplaneta americana (L.)] converted tryptamine hydrochloride to a toluene-extractable material. Optimum conditions for the reaction were obtained with 0.3 M sodium phosphate buffer, pH 6.6, at 30°C. The enzyme was very unstable. Its activity was scarcely inhibited by such typical monoamine oxidase inhibitors as iproniazid phosphate and tranylcypromine hydrochloride. Enzyme activity was not affected by the addition of NADPH₂, but was accelerated by acetyl coenzyme A or coenzyme A. A main product of the enzymic reaction was isolated and identified as N-acetyltryptamine by chromatography and spectroscopic analyses, which suggests that the enzyme is a kind of N-acetyltransferase.  相似文献   

Nodulation during vegetative growth of soybean stage does not affect the susceptibility to red crown rot caused by Calonectria ilicicola     

Junko Tazawa  Motoki Takahashi  Kazuei Usuki  Hiroyuki Yamamoto 《Journal of General Plant Pathology》2007,73(3):180-184

Soybean cultivar Enrei and its derivative lines, non-nodulating En1282 and supernodulating Sakukei 4, were grown in an experiment field naturally infested with the red crown rot fungus, Calonectria ilicicola, to determine whether nodulation elicits the disease. Infection frequency by the fungus invariably increased with time and reached about 100% 6 weeks after sowing. Disease severity was invariably slight until 8 weeks after sowing. At harvest, however, disease severity was lowest in En1282 and highest in Sakukei 4. Enrei was intermediately susceptible. Sakukei 4 produced many more nodules than Enrei, while En1282 completely failed to nodulate. For three other pairs of nodulating and non-nodulating isogenic lines, all non-nodulating lines had lower severity than their nodulating counterparts at harvest. Pot experiments with Enrei and its derivatives revealed that inoculation with Bradyrhizobium sp. did not affect disease severity during the vegetative stage of plant growth, i.e., 6 weeks after sowing. These results suggested that the production of nodules in the vegetative stage is not, at least directly, related to susceptibility to the disease, but physiologic changes after anthesis vary depending on the nodulation traits in the respective soybean lines, resulting in different levels of susceptibility to red crown rot.  相似文献   

Measurement of telomerase activity in dog tumors     

Yazawa M  Okuda M  Setoguchi A  Nishimura R  Sasaki N  Hasegawa A  Watari T  Tsujimoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(10):1125-1129

Telomeres are specific structures present at the end of liner chromosomes. DNA polymerase can not synthesize the end of liner DNA and, as a result, the telomeres become progressively shortened by successive cell divisions. To overcome the end replication problem, telomerase adds new telomeric sequences to the end of chromosomal DNA. The enzyme activity is undetectable in most normal human adult somatic cells, in which shortening of the telomere is thought to limit the somatic-cell life span. In contrast to normal somatic cells, many human tumors possess telomerase activity. The present study looked at whether telomerase activity might serve as a marker for canine tumors. Telomerase activity was measured using the telomeric repeat amplification protocol assay. Normal dog somatic tissues showed little or no telomerase activity, while normal testis exhibited a high level of telomerase activity. We measured telomerase activity in tumor samples from 45 dogs; 21 mammary gland tumors, 16 tumors developed in the skin and oral cavity, 7 vascular tumors and 1 Sertoli cell tumor. Greater than 95% of the tumor samples contained telomerase activity (3-924 U/2 micrograms protein). The results obtained in this study indicated that telomerase should be a useful diagnostic marker for a variety of dog tumors, and it may serve as a target for antitumor chemotherapy.  相似文献   

A dog with acute myelomonocytic leukemia     

Hisasue M  Nishimura T  Neo S  Nagashima N  Ishikawa T  Tsuchiya R  Yamada T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(6):619-621

A three-year-old dog with marked leukocytosis, lymphadenopathy, and diarrhea showed an increase in unidentified blasts in the peripheral blood, and they were proliferated in the bone marrow. The dog was diagnosed with myelomonocytic leukemia (M4) because the blast cells were demonstrated by cytochemical staining to be both myeloid and monocytic cells. Although the dog was treated with a multi-combination chemotherapy and induction therapy using vitamin K2, it died on day 47 after the first admission. This case is the first report of M4 in Japan.  相似文献   

A new ENU-induced mutant mouse with defective spermatogenesis caused by a nonsense mutation of the syntaxin 2/epimorphin (Stx2/Epim) gene     

Akiyama K  Akimaru S  Asano Y  Khalaj M  Kiyosu C  Masoudi AA  Takahashi S  Katayama K  Tsuji T  Noguchi J  Kunieda T 《The Journal of reproduction and development》2008,54(2):122-128

Repro34 is an N-ethyl-N-nitrosourea (ENU)-induced mutation in mice showing male-specific infertility caused by defective spermatogenesis. In the present study, we investigated pathogenesis and molecular lesions in relation to spermatogenesis in the repro34/repro34 homozygous mouse. Histological examination of the testis showed that the seminiferous epithelium of the repro34/repro34 mouse contained spermatogonia and spermatocytes but no round and elongating spermatids. Instead of these haploid cells, multinucleated giant cells occupied the niche of the seminiferous tubules. Immunohistochemical staining for Hsc70t, an elongating spermatid specific protein, confirmed the absence of elongating spermatids. Furthermore, RT-PCR showed that there were significantly reduced expressions of the marker genes specifically expressed in the spermatid and that there was no difference in the expressions of the spermatocyte specific marker genes. These findings indicated interruption of the spermatogenesis during transition from the spermatocyte to spermatid in the repro34/repro34 mouse. The repro34 locus has been mapped on a 7.0-Mb region of mouse chromosome 5 containing the Syntaxin 2/Epimorphin (Stx2/Epim) gene, and targeted disruption of this gene has been reported to cause defective spermatogenesis. We therefore sequenced the entire coding region of the Stx2/Epim gene and found a nucleotide substitution that results in a nonsense mutation of this gene. The expression pattern of the Stx2/Epim gene during the first wave of spermatogenesis, increased expression at later stages of spermatogenesis, was in agreement with the affected phase of spermatogenesis in the adult repro34/repro34 testis. We therefore concluded that the male infertility of the repro34/repro34 mouse is caused by the interruption of spermatogenesis during transition from the spermatocyte to spermatid and that the nonsense mutation of the Stx2/Epim gene is responsible for the interruption of spermatogenesis.  相似文献   

Effect of an Introduced Phytoene Synthase Gene Expression on Carotenoid Biosynthesis in the Marine Diatom Phaeodactylum tricornutum     

Takashi Kadono  Nozomu Kira  Kengo Suzuki  Osamu Iwata  Takeshi Ohama  Shigeru Okada  Tomohiro Nishimura  Mai Akakabe  Masashi Tsuda  Masao Adachi 《Marine drugs》2015,13(8):5334-5357

Carotenoids exert beneficial effects on human health through their excellent antioxidant activity. To increase carotenoid productivity in the marine Pennales Phaeodactylum tricornutum, we genetically engineered the phytoene synthase gene (psy) to improve expression because RNA-sequencing analysis has suggested that the expression level of psy is lower than other enzyme-encoding genes that are involved in the carotenoid biosynthetic pathway. We isolated psy from P. tricornutum, and this gene was fused with the enhanced green fluorescent protein gene to detect psy expression. After transformation using the microparticle bombardment technique, we obtained several P. tricornutum transformants and confirmed psy expression in their plastids. We investigated the amounts of PSY mRNA and carotenoids, such as fucoxanthin and β-carotene, at different growth phases. The introduction of psy increased the fucoxanthin content of a transformants by approximately 1.45-fold relative to the levels in the wild-type diatom. However, some transformants failed to show a significant increase in the carotenoid content relative to that of the wild-type diatom. We also found that the amount of PSY mRNA at log phase might contribute to the increase in carotenoids in the transformants at stationary phase.  相似文献