Search Results - (Author, Cooperation:T. Teranishi)

2018-01-04

American Physical Society (APS)

0556-2813

1089-490X

Physics

Nuclear Astrophysics

2016-03-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Inner retinal cells including dopamine (DA) cells were isolated and fractionated from the carp (Cyprinus carpio) retina by an enzyme cell dissociation and metrizamide gradient centrifugation method. When γ-aminobutyric acid (GABA) antagonists (bicuculline and picrotoxin) were added into the perfusate over such a cell fraction, they stimulated the release of [3H]DA which had been preloaded in the cell fraction. The action of GABA antagonists was dose and Ca2+ dependent. Their minimal effective concentration was very low (0.5 μM). A similar action was elicited by high K+. In the presence of excess GABA, this stimulatory action of GABA antagonists and high K+ on [3H]DA release was completely abolished. To interpret the action of GABA antagonists on DA cells, isolated cell fractions were preincubated with GABAse. After such a treatment, the stimulatory effects of GABA antagonists and high K+ on [3H]DA release were differentiated from each other; the former disappeared whereas the latter remained unchanged. The data strongly suggest that GABA inhibits the DA release from retinal DA cells and thus the GABA antagonists affect [3H]DA release from cell fractions not by a direct membrane action but by a disinhibition mechanism via GABA receptors on the DA cell bodies.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Serotonin (5-hydroxytryptamine, 5-HT; 0.5 μM and above) stimulated the release of [3H]dopamine ([3H]DA) from particulate fractions of the carp (Cyprinus carpio) retina. The 5-HT effect was dose- and Ca2+-dependent, and was structurally specific. A similar response was not elicited by the other indoles (5,6-dihydroxytryptamine, 5,7-dihydroxytryptamine, 5-hydroxytrypto-phan, or 5-hydroxyindoleacetic acid) examined. An increase in [3H]DA release was elicited by addition of 5-HT agonists (5-methoxytryptamine, 5-methoxy-N,N- dimethyltryptamine, and tryptamine), but not antagonized by three 5-HT antagonists (metergolin, methysergide, and spiperone). Either DA alone or noradrenaline (0.5 mM) produced a large increase in [3H]DA release from the particulate fractions, but this action was Ca2+-independent. Further, no significant release of [3H]γ-aminobutyric acid could be evoked by 5-HT (0.5 mM) under similar experimental conditions. Taken together, the present data suggest that 5-HT stimulates [3H]DA release from the fish retina through a specific receptor-mediated mechanism on dopaminergic terminals, but not through an exchange or nonspecific phenomenon.

Electronic Resource

0006-291X

[abr] IL-2; interleukin 2 ; [abr] PHA-M; phytohemagglutinin-M ; [abr] T-cell; thymus-derived cell ; [abr] TPA; 12-o-tetradecanoyl phorbol 13-acetate ; [abr] bp; base pairs ; [abr] cDNA; complementaryDNA ; [abr] kb; kilobase pairs ; [abr] poly(A) ^+RNA; polyadenylated RNA ; [abr] s.d.; standard deviation

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0008-6215

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0378-4347

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0006-291X

[abr] IL-2; interleukin 2 ; [abr] PHA-M; phytohemagglutinin-M ; [abr] T-cell; thymus-derived cell ; [abr] TPA; 12-o-tetradecanoyl phorbol 13-acetate ; [abr] bp; base pairs ; [abr] cDNA; complementaryDNA ; [abr] kb; kilobase pairs ; [abr] poly(A) ^+RNA; polyadenylated RNA ; [abr] s.d.; standard deviation

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0375-9601

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9601

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9601

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0370-2693

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0304-8853

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0304-8853

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1434-601X

PACS: 25.40.Lw Radiative capture – 35.60.-t Reactions induced by unstable nuclei – 25.70.De Coulomb excitation – 25.70.Mn Projectile and target fragmentation – 26.65.+t Solar neutrinos

Springer Online Journal Archives 1860-2000

Physics

Abstract: We have measured the dissociation of 8B in the Coulomb field of 208Pb at Ein=51.9 MeV/nucleon and extracted the cross section of the 7Be(p,γ)8B reaction at 0.4 ≤ Erel≤ 3 MeV, which is of importance for the 8B solar-neutrino production rate. The extracted astrophysical S17 factors are consistent with our earlier Coulomb dissociation measurement, and agree with the values deduced from the direct capture measurements by Filippone et al., Vaughn et al. and Hammache et al. The S factor at zero energy was extracted to be 18.9±1.8 eV-b with the help of theoretical energy-dependence.

Electronic Resource

0165-1161

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0392-6737

Optical properties and materials

Springer Online Journal Archives 1860-2000

Physics

Riassunto Gli spettri di riflettanza del dicroismo magnetocircolare di un semiconduttore ferromagnetico CdCr2Se4 sono stati misurati per temperature tra 4.2 K e 157 K. Gli elementi fuori dalla diagonale del tensore dielettrico sono stati calcolati dagli spettri misurati. Si è determinato un certo numero di strutture fini, la cui posizione energetica è stata rappresentata in un grafico rispetto alla temperatura. Si è trovato che ci sono due strutture che si spostano nel rosso: una a 1.1 eV (il ben noto picco di assorbimento) e l'altra a 1.9 eV. Altre strutture mostrano un leggero spostamento nel blu. Queste posizioni di energia sono state confrontate con la struttura di banda calcolata mediante la tecnica autoconsistenteDV-Xα.

Резюме В области температур от 4.2 К до 157 К измеряются спектры отражательной способности ферромагнитного полупроводника CdCr2Se4. Для измеренных спектров вычисляются недиагональные элементы диэлектрического тензора. Разрешается ряд тонких структур, энергетическое положение которых вычерчивается в зависимости от температуры. Обнаружено, что существуют две структуры, обладающие красным смещением; одна при 1.1 эВ (хорошо известный край поглощения) и другая при 1.9 эВ. Другие структуры обладают голубым смещением. Энергетические положения зтих структур сравниваются с зонной структурой, вычисленной с помощьюDV-Xα метода.

Summary Reflectance magnetocircular-dichroism spectra of a ferromagnetic semiconductor CdCr2Se4 were measured for temperatures between 4.2 K and 157 K. Off-diagonal elements of the dielectric tensor were calculated from the measured spectra. A number of fine structures was resolved, the energy position of which was plotted against temperature. It is found that there are two red-shifting structures: one at 1.1 eV (the well-known absorption edge) and the other at 1.9 eV. Other structures show slight blue-shift. These energy positions were compared with the band structure calculated by means of the self-consistentDV-Xα technique.

Electronic Resource

1573-6830

fish retina ; immunohistochemistry ; rod precursor cells ; proliferating cell nuclear antigen (PCNA) ; 6-hydroxydopamine ; regeneration

Springer Online Journal Archives 1860-2000

Biology

Summary 1. The dopaminergic neurotoxin, 6-hydroxydopamine (6-OHDA), was injected intravitreally into the eyes of juvenile (5- to 6-cm) goldfish. 2. Proliferation of rod neuroblasts caused by 6-OHDA (2µg in 2µl saline) was detected in retinal wholemounts by immunofluorescence for proliferating cell nuclear antigen (PCNA) 3, 7, 14, 20, or 30 days after injection. 3. The injected dose of 6-OHDA was sufficient to cause permanent loss of dopaminergic interplexiform and serotonergic amacrine cells in the injected eye but not in the contralateral control eye. 4. 6-OHDA increased the density (mm−2) of PCNA-ir cells in theouter nuclear layer (ONL) of the injected eye to 2.65 times the initial density 20–30 days after injection, and it increased the density of PCNA-ir cells in the ONL of the contralateral, untreated eye, equally but after a delay of ⩽7 days with respect to the injected eye. 5. 6-OHDA also increased the density of PCNA-ir cells in theinner nuclear layer (INL) to 〉20 times the initial density 7 days after injection, followed by a rapid decline almost to control levels by 14 days after injection. 6. The sequence of responses to 6-OHDA, with PCNA-ir cells first scattered in the ONL and then clustered in the INL, suggests that neuroblasts from the ONL migrate to the INL to compensate for toxin-induced cell loss. 7. Double staining for 5-bromodeoxyuridine (BrUdR; a thymidine analogue) and PCNA, carried out on 7 days after intravitreal injection with 6-OHDA, showed that 77% of all PCNA-ir cells in the outer nuclear layer had been in S phase during the previous 24 hr. 8. Immunoreactivity for PCNA was found to be a valid marker for rod neuroblasts which have entered S phase within 1–2 days before sampling and was shown to be especially convenient for investigating the distribution of proliferating cells in whole mounts. 9. In controls injected unilaterally with saline or saline plus 1% dimethyl sulfoxide (DMSO), the differences in densities of PCNA-ir rod precursor nuclei 2–30 days after injection vs. day 0 (uninjected) were statistically insignificant in both injected and uninjected eyes (Negishiet al., 1991). Therefore the local effect of injecting 6-OHDA was due to 6-OHDA itself, not to mechanical damage or nonspecific actions of foreign substances. 10. The proliferative response of rod neuroblasts in the injected eye could be due in part to impairment of dopaminergic regulation of the neuroblasts and also in part to mitogen(s) released from damaged cells. The proliferative response of rod neuroblasts in theuninjected control eye, however, is likely to be caused by diffusible mitogen(s) released from the treated retina.

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