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  • 1990-1994  (7)
  • 1985-1989  (12)
  • 1965-1969  (1)
  • 11
    Digitale Medien
    Digitale Medien
    Phosphoramidon enhances allatostatin-mediated inhibition of juvenile hormone biosynthesis in the corpora allta of the cockroach,Diploptera punctata (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 758-761 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Corpora allata ; juvenile hormone biosynthesis ; allatostatins ; phosphoramidon ; enkephalinase ; cockroach ; Diploptera punctata ; ELISA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Use of the enkephalinase inhibitor phosphoramidon in the in vitro radiochemical assay for juvenile hormone biosynthesis enhanced allatostatin-mediated inhibition of hormone production by corpora allata of the cockroach,Diploptera punctata. Significant increases in inhibition in day 2 virgin female CA by AST 1 (at 10−7 M) and AST 4 (10−8–10−7 M) were observed in the presence of phosphoramidon (10−5M or greater). No significant increases in inhibition were seen in CA from day 6 mated females with AST 4 (10−9–10−7M) and phosphoramidon combined. Phosphoramidon alone had no effect on JH biosynthesis. Analysis of allatostatin content of the CA, as determined by ELISA, revealed that addition of phosphoramidon to the medium increased the endogenous allatostatin conten in CA of virgin and mated females. The similarity in primary structure between allatostatins and enkephalin-like peptides and their similar distribution makes it probable that phosphoramidon acts by preventing breakdown of allatostatins within the CA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02124297
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  • 12
    Digitale Medien
    Digitale Medien
    Petrology and magnetic properties of the Chiang Khan, Thailand, meteorite (1989)
    Springer
    Mineralogy and petrology 40 (1989), S. 173-182 
    Details
    ISSN: 1438-1168
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Summary The Chiang Khan meteorite fell on 18th November, 1981 at Chiang Khan, Thailand. It consists of olivine, orthopyroxene, clinopyroxene, Fe-Ni metal, troilite, chromite, plagioclase, glass, and phosphate in order of abundance. Olivine forms barred or porphyritic chondrules, and its composition is uniform (average Fo80.2), close to the average composition of olivine in equilibrated H chondrites. Orthopyroxene and clinopyroxene also have compositions similar to those in equilibrated H chondrites. Both well-defined chondrules and their broken fragments are present in the recrystallized matrix. Microcrystalline plagioclase and clinopyroxene often occur in the groundmass of chondrules, but clear interstitial plagioclase is absent. Chemical composition of chromite plots in the field of chromites in H chondrites. Chiang Khan meteorite is thus classified as an equilibrated H 5 type chondrite. The equilibrium temperatures estimated by using mineral pairs are as follows: Opx-Cpx 800–900°C; Ol-Chromite 510°C. Water content is 0.24 wt %, and the hydrogen isotopic composition (ΔD) is −89.5‰ In the thermal demagnetization experiment magnetization steadily decreased from 0 to 500°C, whereas the remanent magnetization obtained in the A.C. demagnetization experiment is very unstable, probably owing to the large grain size of the Fe-Ni metal.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01164487
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  • 13
    Digitale Medien
    Digitale Medien
    Expression of the mutant gene for L-gulono-γ-lactone oxidase in scurvy-prone rats (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 126-129 
    Details
    ISSN: 1420-9071
    Schlagwort(e): L-gulono-γ-lactone oxidase ; ascorbic acid deficiency ; enzyme defect ; rat ; nuclei acid hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A mutant strain of Wistar rats with L-gulono-γ-lactone oxidase deficiency has recently been established. To investigate this deficiency by DNA and RNA blot hybridization analyses, a fragment of a previously cloned cDNA encoding rat L-gulono-γ-lactone oxidase was used as a probe. When genomic DNA of the mutant rat was digested with several restriction enzymes, the probe hybridized to fragments of the same sizes as those produced from DNA of normal rats. Poly(A)+RNA from the liver of the mutant rat was found to contain an L-gulono-γ-lactone oxidase-specific mRNA of a normal size at a comparable level to that of normal rats. An in vitro translation experiment revealed that the mRNA programmed the synthesis of an enzyme protein which had the same molecular weight as that of the translational product of the normal mRNA, although the amount synthesized was markedly reduced as compared with that synthesized with the normal mRNA. In accordance with this observation, a very low but definite degree of L-gulono-γ-lactone oxidase activity was detected in the microsomes of the mutant rat by a newly developed, highly sensitive method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01954844
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  • 14
    Digitale Medien
    Digitale Medien
    Differential effects of naloxone on neuroendocrine responses to fear-related emotional stress (1990)
    Springer
    Experimental brain research 81 (1990), S. 53-58 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Vasopressin ; Oxytocin ; Adrenocorticotrophic hormone ; Emotional stress ; Opioid ; Prolactin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of an opioid receptor antagonist, naloxone (NAL), were studied on the changes in pituitary hormone secretion induced by emotional stress. Male Wistar rats were trained with tone stimuli paired with electric footshocks and tested with the tone and environmental cue signals for emotional stress of fear acquired by learning as described previously (Onaka et al. 1988). Rats received s.c. injected NAL 30 min before testing at doses of 0, 0.2, 1.0, 5.0 and 25.0 mg/kg b.w. Half the rats were injected with 0.5 M NaCl (20 ml/kg b.w.) together with NAL. In these hypertonic rats plasma vasopressin level was slightly increased after NAL. The increment was statistically significant in control groups but not in experimental groups. However the suppression of vasopressin secretion by emotional stimuli was not changed by NAL. Plasma oxytocin levels were extremely high and not significantly different among experimental, unshocked control and untested control groups. NAL further increased the oxytocin level dose-dependently. NAL did not significantly change plasma adrenocorticotrophic hormone (ACTH) levels and hence did not modify the augmentative response in ACTH secretion to emotional stimuli. Plasma prolactin level was significantly elevated after emotional stimuli and NAL depressed the prolactin level in each of experimental and control groups. After NAL, the magnitude of the facilitatory response in prolactin secretion to emotional stimuli was decreased. Motor activity and its suppressive response to emotional stimuli were not influenced by NAL. In another half of rats under a normal osmotic condition the vasopressin response to emotional stimuli was not affected by NAL. NAL further augmented potentiation of oxytocin secretion after emotional stimuli dose-dependently. Effects of NAL on ACTH level, prolactin level and motor activity were similar to those in rats under hypertonic conditions. These results demonstrate that endogenous opioids are selectively and differentially involved in hypothalamo-hypophysial responses to fear-related emotional stress.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230100
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  • 15
    Digitale Medien
    Digitale Medien
    Synergistic activation of rat supraoptic neurosecretory neurons by noxious and hypovolemic stimuli (1986)
    Springer
    Experimental brain research 62 (1986), S. 572-578 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Vasopressin cell ; Noxious input ; Hypovolemia ; Supraoptic nucleus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of saphenous nerve stimulation on discharge activity of supraoptic neurosecretory (NS) cells were studied in anesthetized rats. Of 112 supraoptic neurosecretory cells, 62 exhibited a ‘phasic’ discharge pattern. The nerve stimulation transiently excited 46 of these 62 ‘phasic’ units, as well as 35 of the 50 remaining ‘non-phasic’ units. No appreciable blood pressure change was noted using PSTHs with 1-ms resolution. Though the nerve stimulation also evoked a flexor reflex of the ipsilateral hind limb, blockage of the hind limb movement with gallamine did not alter the amplitude of the supraoptic cell excitation. The threshold of the nerve stimulation was higher for the excitation than for the flexor reflex. Effects of hypovolemic and hyperosmotic stimuli on discharge activity of ‘phasic’ cells during saphenous nerve stimulation were studied to find a possible interaction between these stimuli. Hemorrhage potentiated the transient excitation evoked by the nerve stimulation in all of the 8 ‘phasic’ cells tested, while no such effect was seen after an injection of hypertonic sodium chloride solution in the 7 ‘phasic’ cells tested. These electrophysiological data suggest that hypovolemic and noxious stimuli potentiate VP secretion in a synergistic manner but that hyperosmotic and noxious stimuli do not.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236036
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  • 16
    Digitale Medien
    Digitale Medien
    Vasopressin secretion: suppression after light and tone stimuli previously paired with footshocks in rats (1988)
    Springer
    Experimental brain research 71 (1988), S. 291-297 
    Details
    ISSN: 1432-1106
    Schlagwort(e): ACTH ; Emotional response ; Motor activity ; Vasopressin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In an attempt to find whether vasopressin (VP) secretion is suppressed by learned emotional stress, we have given rats under a hypertonic condition simultaneously applied light and tone that had been paired previously with footshocks and have quantified immunoreactive VP (ir-VP) in the plasma. In a training session light (60 watt) and tone (2 kz) of 3-s duration which were paired with electric footshocks (50 Hz, 1-s duration) were given to rats 11 times at an interval of 30 s. Various lengths of time after the training, the rats were tested with light and tone, which were unpaired with footshocks and repeatedly applied every 15 s for 3 min in the box used for training. Hypertonic NaCl (0.5 M, 2 ml/ 100 g b. w.) was injected s. c. 30 min before testing to increase the basal level of plasma VP. After testing, plasma ir-VP was significantly less in the experimental group than in the 0-mA control group of rats that were trained without FS. The values for the experimental group were also significantly less than those of untested control rats that had been trained with FS but were not tested. Plasma osmolality and blood haemoglobin concentration were not significantly different between control and experimental groups. Plasma immunoreactive adrenocorticotrophic hormone (ir-ACTH) level was higher and motor activity as expressed by cumulative time period of body movement during testing was lower in the experimental group than in either of the control groups. The difference in plasma ir-VP between experimental and control groups was statistically significant two days but not seven days after training, whereas ACTH and motor activity in experimental groups were still significantly different from those in control groups seven days after training. The suppressive VP and augmentative ACTH responses to testing disappeared in the rats that had received light and tone repeatedly during the intervening period between training and testing. These data support the hypothesis that emotional stimuli suppress VP secretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00247489
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  • 17
    Digitale Medien
    Digitale Medien
    Epidemiological studies of hemorrhagic fever with renal syndrome (HFRS) related virus infection among urban rats in Hokkaido, Japan (1986)
    Springer
    Archives of virology 88 (1986), S. 231-240 
    Details
    ISSN: 1432-8798
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Seroepidemiological studies of hemorrhagic fever with renal syndrome (HFRS) virus infection were carried out among urban rats(Rattus norvegicus andRattus rattus) and small field rodents in Hokkaido, Japan. An urban rat colony that was seropositive to SR-11 strain of HFRS virus (laboratory rat origin) was demonstrated in February 1983 at a dumping ground area of Kami-iso Town near Hakodate port. An HFRS-related virus, named KI-262 strain, was isolated from the lung tissue of a seropositive rat using Vero-E6 cell culture. Antigenicity of the isolate was closely related to Hantaan 76–118 and SR-11 strains by the indirect immunofluorescent antibody (IFA) test. No seropositive rat was found among the 861 rats captured in 38 other regions. It is unclear whether or not the infected rats in the positive area were introduced from abroad, though the area is located near Hakodate International Port. Furthermore, higher positive rates of urban rats in the Kami-iso area were observed in the spring and winter than in the summer and fall. Significantly high proportion of positive cases was observed among adult rats (six months or older) than among younger animals. The seasonal and age distribution of postive cases suggested that the virus was not readily transmitted from one infected rat to another. One seropostive case of a small field mouse(Clethrionomys rufocanus bedfordiae) was detected around the Kami-iso area.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01310877
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  • 18
    Digitale Medien
    Digitale Medien
    Distribution of glycosylglycerols and oligosaccharides in the marine environment and their ecological significance in the deep sea (1990)
    Springer
    Marine biology 106 (1990), S. 309-313 
    Details
    ISSN: 1432-1793
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Determination of low molecular weight carbohydrates in marine environments indicated that 1-O-β-D-galactosylglycerol, 6-O-α-D-galactosyl-1-O-β-D-galacto-sylglycerol, sucrose, laminaribiose and laminaritriose are widely distributed in seawaters, suspended and sinking particles, and sediments in coastal as well as in deep-sea waters [e.g. Mikawa Bay and Sagami Bay, Kumano Nada (offshore Japan), and northwest North Pacific Ocean, Bering Sea and Antarctic Ocean: collections during 1978–1984]. Identification of these glycosylglycerols and oligosaccharides in algal cells such as a flagellate (Olisthodisus luteus), blue-green algae (e.g.Trichodesmium sp.) and a diatom (Reptocylindrus denicus) strongly suggests that these sugars are photosynthetically produced by algae in the euphotic zone and are then rapidly transported to the deep sea as sinking particles which can be collected by sediment-trap experiments. The rapid decay rate of low molecular weight carbohydrates by microorganisms suggests that the transported sugars provide energy substrates for microorganisms living in the deep sea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01314815
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  • 19
    Digitale Medien
    Digitale Medien
    S15.11 Lipid peroxide level of cultured endothelial cells of artery is increased by glycated protein and an iron chelate (1993)
    Springer
    Glycoconjugate journal 10 (1993), S. 315-315 
    Details
    ISSN: 1573-4986
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01210097
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  • 20
    Digitale Medien
    Digitale Medien
    The effects of octopamine on juvenile hormone biosynthesis, electrophysiology, and cAMP content of the corpora allata of the cockroach Diploptera punctata (1990)
    Springer
    Journal of comparative physiology 160 (1990), S. 241-249 
    Details
    ISSN: 1432-136X
    Schlagwort(e): Octopamine ; Juvenile hormone ; cAMP ; Cockroach ; Electrophysiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Juvenile hormone production by the corpora allata of the adult female cockroach, Diploptera punctata, can be modulated by treatment with the biogenic amine, octopamine. Endogenous octopamine has been identified within the CA, using HPLC and electrochemical detection. Treatment with octopamine results in a sinusoidal, dose-dependent inhibition of JH biosynthesis by CA from day 2 virgin females, with maximal inhibition occurring at 10-10 M and 10-4 M. In day 4 and day 8 mated female corpora allata octopamine inhibited JH biosynthesis at 5·10-5 M. Although the elevation of either cAMP or cGMP within the CA is known to be associated with an inhibition of JH biosynthesis, treatment with high concentrations of octopamine results in an increase in the level of cAMP but not cGMP. This effect is both dose- and time-dependent. Octopamine treatment also initiates changes in the passive membrane responses of the CA. Superfusion of CA with octopamine results in a pronounced hyperpolarization of CA cells and an increase in the electrotonic potential (indicative of the degree of electrical coupling between CA cells). This effect could be blocked by the octopamine receptor blocker phentolamine. Treatment with octopamine or phentolamine also blocked the hyperpolarization of CA cells normally associated with electrical stimulation of the axon tracts innervating the CA. We hypothesize that octopamine may be a natural neuromodulator of JH production by CA, regulating ion channels in CA cells themselves as well as release of the inhibitory neuropeptide, allatostatin, from the terminals within the CA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302589
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