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941.
The silkworm, Bombyx mori, was reared aseptically on a synthetic diet with and without β-carotene and the effects of carotenoid and vitamin A deficiency on photosensitivities in larval phototaxis, visual function and adult eclosion were studied.β-Carotene or vitamin A acted as a growth-promoting factor in continuous darkness and under photoperiodic conditions. The deficiency of β-carotene decreased the larval phototactic response as growth proceeded. The offspring larvae from eggs laid by β-carotene-deficient moths also lost the phototactic response, but successive rearing with dietary β-carotene or vitamin A re-established the response. The deficiency of β-carotene caused the loss of the electric response by light stimuli in the ocelli of fifth instar larvae and the compound eyes of adult moths. These results indicate that vitamin A is essential for visual function in the silkworm, as reported in other insects. The lack of carotenoid did not affect the development of the pupae or the specific time of eclosion which is regulated by a photoperiodic condition of pupal stage. This observation suggests that the carotenoid and its derivative are not involved in photoreception for the entrainment of the adult eclosion of the silkworm. 相似文献
942.
943.
Shigeo Katsumura Seiji Iwama Takeshi Matsuda Takeshi Tani Shinobu Fuji Kiyoshi Ikeda 《Bioorganic & medicinal chemistry letters》1993,3(12):2703-2706
(S)- and (R)-3-dodecanoyl-4-phosphatidylcholinohydroxymethyl-2-oxazolidinone (1), which are cyclic analogues of the amide phospholipid 7, were synthesized. The inhibitory activities of these analogues toward phospholipase A2 were compared with that of the amide analogue 7. 相似文献
944.
Bo Li Jingya Li Yi Fan Zhihe Zhao Longjiang Li Hideyuki Okano Takehito Ouchi 《Biological reviews of the Cambridge Philosophical Society》2023,98(5):1749-1767
Cranial bones constitute a protective shield for the vulnerable brain tissue, bound together as a rigid entity by unique immovable joints known as sutures. Cranial sutures serve as major growth centres for calvarial morphogenesis and have been identified as a niche for mesenchymal stem cells (MSCs) and/or skeletal stem cells (SSCs) in the craniofacial skeleton. Despite the established dogma of cranial bone and suture biology, technological advancements now allow us to investigate these tissues and structures at unprecedented resolution and embrace multiple novel biological insights. For instance, a decrease or imbalance of representation of SSCs within sutures might underlie craniosynostosis; dural sinuses enable neuroimmune crosstalk and are newly defined as immune hubs; skull bone marrow acts as a myeloid cell reservoir for the meninges and central nervous system (CNS) parenchyma in mediating immune surveillance, etc. In this review, we revisit a growing body of recent studies that explored cranial bone and suture biology using cutting-edge techniques and have expanded our current understanding of this research field, especially from the perspective of development, homeostasis, injury repair, resident MSCs/SSCs, immunosurveillance at the brain's border, and beyond. 相似文献
945.
Amino acid sequence of heat-labile enterotoxin from chicken enterotoxigenic Escherichia coli is identical to that of human strain H 10407 总被引:2,自引:0,他引:2
Takashi Inoue Takao Tsuji Michio Koto Seiji Imamura Akio Miyama 《FEMS microbiology letters》1993,108(2):157-161
Abstract The DNA sequence of heat-labile enterotoxin from the chicken enterotoxigenic Escherichia coli 21d strain was determined by direct dideoxy sequencing of polymerase chain reaction (PCR)-amplified DNA and was compared with those of heat-labile enterotoxins from porcine and human enterotoxigenic E. coli strains EWD 299 and H 10407. The structural genes of the A and B subunits of chicken heat-labile enterotoxin were identical to those of human heat-labile enterotoxin from the human H 10407 strain. Moreover, 67 base pairs of the upstream and 60 base pairs of the downstream region of the chicken heat-labile enterotoxin gene were also identical to those of the human heat-labile enterotoxin from strain H 10407. However, the patterns of plasmids from the 21d and H 10407 strains were different. The 21d strain had no band corresponding to the 42-MDa plasmid of the H10407 strain encoding the heat-labile enterotoxin gene but it had a smaller plasmid. These data suggest that although the DNA sequence of chicken heat-labile enterotoxin is identical to that of human heat-labile enterotoxin, the plasmid encoding the chicken heat-labile enterotoxin gene in the chicken might be different from that encoding the human heat-labile enterotoxin gene in the H10407 strain. 相似文献
946.
Human pro-urokinase (pro-UK) gene was engineered for expression in mammalian cells. The stability of recombinant pro-UKs produced by two kinds of cells, Chinese hamster ovary (CHO) and human lymphoblastoid Namalwa KJM-1 cells, were compared. The pro-UK expressed in CHO cells in serum-free medium was degraded by cysteine endopeptidase secreted by CHO cells. This endopeptidase was inhibited by pchloromercuribenzonate (PCMB) and leupeptin more efficiently than by aprotinin. On the other hand, the pro-UK expressed in Namalwa KJM-1 cells was not degraded, resulting in the stable production of pro-UK at a rate of 2–3 g/106 cells/day by use of a gene amplification method with dihydrofolate reductase (DHFR) in serum-free medium. Thus, Namalwa KJM-1 cells showed the desired characteristics as a host cell for the production of recombinant proteins. The stability of recombinant proteins produced in heterologous systems may vary depending on the host cells.Abbreviations ABTS
2,2-azino-di-(3-ethylbenzothiazoline) sulfonic acid diammonium salt
- AMC
7-amino-4-methylcoumarin
- CHO
Chinese hamster ovary
- DFP
diisopropylfluorophosphate
- DHFR
dihydrofolate reductase
- ELISA
enzyme-linked immunosorbent assay
- MCA
4-methylcoumaryl-7-amide
- MTX
methotrexate
- NEAA
non essential amino acid
- NEM
N-ethylmaleimide
- PCMB
p-chloromercuribenzonate
- PMSF
phenylmethanesulfonyl fluoride
- pro-UK
pro-urokinase 相似文献
947.
Hiroshi Hosokawa Seiji Nyu Koichi Nakamura Kumato Mifune Shigeyuki Nakano 《Chronobiology international》1993,10(4):259-270
A once-daily dosage regimen has been recently recommended in the use of aminoglycoside antibiotics since they induce a postantibiotic effect. In choosing this regimen, one must determine the most appropriate time of day for administration of the drug. We investigated the effects of the timing of amikacin (AMK) administration on the kinetics, the efficacy against intraperitoneal infection with Pseudomonas aeruginosa, and the toxicity of AMK in mice with and without immijnosuppression. We found circadian variations in the kinetics, efficacy, and toxicity of the drug in mice. Male and female ICR mice, which were housed under a light-dark (12:12 h) cycle with free food and water intake, were injected subcutaneously with AMK sulfate 50 mg/kg body wt. There was a circadian variation in AMK clearance for both sexes with the maximum value in the dark phase and the minimum in the light phase after a single administration. When AMK 500 mg/kg/day was repeatedly administered once daily for 30 days, higher toxicity was demonstrated in mice injected with the drug at the time of day with lower AMK clearance, although no difference was demonstrated in the toxicity between the two time points with different AMK clearance when AMK 1,500 mg/kg was administered in a single dose. The ED50 of AMK to cure the infected mice in the midlight phase (13:00 h) with lower clearance was significantly lower than that in the middark phase (01:00 h) with higher clearance. In contrast, the ED50 in the early light phase (09:00 h) was significantly lower than that in the early dark phase (21:00 h), although AMK clearance was not different between these two different time points. In mice premedicated with cyclophosphamide to suppress immune functions, the difference in the ED50 of AMK was still demonstrated between 13:00 and 01:00 h, but not between 09:00 and 21:00 h. The present study shows not only that there were circadian variations in both AMK clearance and toxicity after repeated administration, but also that there was a circadian variation in the efficacy of AMK in mice infected with P. aeruginosa. These results suggest that the timing of drug administration should be considered in pharmacotherapy with AMK and that the most appropriate time of administration in mice and nocturnal animals may be in the midlight (resting) phase. They also suggest that the ED50 of AMK. against P. aeniginosa infection may be influenced not only by the circadian variation in pharmacokinetics but also by the variations in immune systems suppressed by cyclophosphamide. 相似文献
948.
Seiji Kawamoto Masahiro Shoji Yuko Setoguchi Masatoshi Kato Shuichi Hashizume Akira Ichikawa Kazuhiro Osada Yoshinori Katakura Hirofumi Tachibana Hiroki Murakami 《Cytotechnology》1995,17(2):103-108
The human monoclonal antibody AE6F4 specifically reacts with human lung cancer tissues but does not with normal tissues. This monoclonal antibody recognizes a cytosolic 31 kDa antigen in the cancer cells. In a previous study, we elucidated that the 31 kDa antigen belonged to a family of proteins collectively designated as 14-3-3 proteins, which were known as protein kinase-dependent activators of tyrosine/trytophan hydroxylases, or protein kinase C inhibitor proteins. Here we report molecular cloning of the 31 kDa antigen from the human lung adenocarcinoma cell line, A549. Sequencing analysis indicates that the cloned cDNA is identical to that of previously reported human placental cytosolic phospholipase A2 (cPLA2), which is also a member of the 14-3-3 protein family. Western analysis demonstrated that a 31 kDa recombinant cPLA2 expressed in monkey COS cells was recognized by the AE6F4 monoclonal antibody. Binding of the monoclonal antibody to the recombinant cPLA2 was abolished when treated with sodium periodate, suggesting that not only are carbohydrate chains associated with the cPLA2, but they also play a crucial role in antigen recognition by the monoclonal antibody. 相似文献
949.
Shinji Hosoi Mitsuo Satoh Katsuya Higo Seiji Sugimoto Hiromasa Miyaji Akira Karasawa Kazuo Yamaguchi Mamoru Hasegawa Tatsuya Tamaoki 《Cytotechnology》1995,19(2):125-135
Pro-UKGS1 was designed as a long-life and thrombin-resistant derivative of pro-urokinase (pro-UK) by deleting the growth factor domain of pro-UK and introducing a glycosylation site near the thrombin cleaving site for thrombin-resistance using site-directed mutagenesis. An expression plasmid for pro-UKDGS1, pIH1UKGS1SEd1–5 was constructed and introduced into Namalwa KJM-1, a lymphoblastoid cell line adapted to serum-free medium, and cells resistant to G418 and Methotrexate (MTX) were obtained. Amongst them, the highest pro-UKGS1 producer (resistant to 200 nM of MTX), clone 2–9, was selected and used for further studies.Under the conventional conditions, i.e. at 37°C in serum-free ITPSGF medium (based on RPMI-1640 medium), the oligosaccharide structure of pro-UKGS1 produced by clone 2–9 mainly consisted of fucose (Fuc)-containing biantennary complex-type oligosaccharide. Addition of dexamethasone (Dex), changed the carbohydrate contents in the media, and a shift down of incubation temperature caused a change in oligosaccharide structure of pro-UKGS1 from mainly Fuc-containing biantennary to mainly Fuc-containing tri-and tetraantennary complex-type oligosaccharide. The modulated pro-UKGS1 showed superiorin vivo activity for a canine femoral thrombosis formed by inserting a copper-coil.Abbreviations Dex
Dexamethasone
- dhfr
dihydrofolate reductase
- DO
dissolved oxygen
- EPO
erythropoietin
- Fruc
fructose
- Fuc
fucose
- Gal
galactose
- Glu
glucose
- GlcN
glucosamine
- Hepes
4-(2-hydroxyethyl)-1 piperazineethanesulfonic acid
- kb
kilobase pairs
- kDa
kilodalton
- Man
mannose
- MTX
methotrexate
- pro-UK
pro-urokinase
- RA
retinoic acid
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- T3
tri-iodothyronine 相似文献
950.
Yokota Etsuo; Sonobe Seiji; Igarashi Hisako; Shimmen Teruo 《Plant & cell physiology》1995,36(8):1563-1569
The latent ability of plant microtubules to translocate or slidein the presence of motor proteinwas examined in a motility assayin vitro. Plant microtubules isolated from tobacco BY-2 cellsmoved over a glass surface covered with outer arm 21S dyneinfrom flagella of sea urchinsperm with an average velocity of3.7 µm s-1. This velocity was similar to that of microtubulesisolated from bovine brain under the same conditions (averagevelocity, about 4.1 µm s-1). These results suggest thatplant microtubules have an intrinsic ability to interact withand to be translocated by dynein. It is postulated that microtubule-basedmotor proteins, including dynein ATP-ase,are involved in thefunctioning of microtubules in plant cells. (Received May 20, 1995; Accepted September 18, 1995) 相似文献