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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 34 (1976), S. 101-107 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Digitonin extracts from retinas of the marine fish Porichthys notatus, from California and Puget Sound (USA), contain a single photopigment with maximum absorbance at 498 nm. In the presence of hydroxylamine the final product of bleaching absorbs maximally at 367 nm, indicating that the photopigment is based on retinal. Spectral sensitivity measurements performed on intact eyes and eye-cup preparations in darkadapted and selectively light-adapted states yield curves which suggest that the retina of P. notatus contains at least 3 different types of receptors. In the darkadapted state, the spectral sensitivity curve has a broad peak, with a maximum between 480 and 500 nm. In the blue and red light-adapted states, in addition to depressing the sensitivity, the shape of the sensitivity curve also changes. Under these conditions new peaks appear which suggest the presence of at least two different types of cones, with sensitivity maxima in the blue and the green regions of the spectrum, respectively. Comparison of the spectral sensitivity curves with the in vivo bioluminescence emission spectrum of the fish gives an especially good correspondence and suggests that the fish is able to perceive the bioluminescence of its own species.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0090-6980
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Specimens of Porichthys notatus were obtained by trawling near Santa Monica Bay, California, and at Puget Sound, Washington. Eggs and early embryonic stages were collected inter and sub-tidally near Santa Barbara, California. Since only adult males of P. notatus, but not P. myriaster, were ...
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 207 (1965), S. 497-500 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] THERE is substantial evidence that ribosomal particles are connected with protein synthesis. According to this concept, an unstable fraction of ribo-nucleic acid (UNA), formed through a deoxyribonucleic acid (DNA)-dependent synthesis1 and acting as a messenger2-6, provides the code for protein ...
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1420-908X
    Keywords: Key words: Diflorasone diacetate — Betamethasone dipropionate — Beclomethasone dipropionate — Endotoxin-induced uveitis — Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: We investigated the anti-inflammatory effects of 16β-methyl-17α,21-diesterified glucocorticoids which are well known as potent topical glucocorticoids in man on endotoxin-induced uveitis (EIU) in rats.¶Material: Female Lewis rats were used.¶Treatment: Glucocorticoids were instilled (0.01% - 1.0%) or subcutaneously injected (0.1 - 10 mg/kg) to rats.¶Methods: To elicit EIU, LPS (500 μg/kg) was injected into the footpad of rats. Twelve hours after LPS injection, cell number in aqueous humor was counted by flow cytometry. Endotoxin-induced in vivo tumor necrosis factor-α (TNF-α) production was also examined.¶Results: 16β-methyl-17α,21-diesterified glucocorticoids showed no effects or some enhancement of cell infiltration into the aqueous humor in EIU by topical instillation. Systemic injection of these glucocorticoids showed only weak inhibition of cell infiltration and TNF-α production. On the other hand, betamethasone phosphate strongly inhibited the cell infiltration and TNF-α production. Combined systemic injection of 16β-methyl-17α,21-diesterified glucocorticoids and betamethasone phosphate reduced the inhibitory effects of the latter.¶Conclusions: These results suggest that 16β-methyl-17α,21-diesterified glucocorticoids might act as partial agonists of glucocorticoid in rats.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Inflammation research 46 (1997), S. 486-490 
    ISSN: 1420-908X
    Keywords: Key words: Betamethasone — Betamethasone dipropionate — Endotoxin-induced uveitis — Prostaglandin E2— Guinea pigs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: We reported previously that the betamethasone derivative betamethasone dipropionate behaves as an anti-glucocorticoid in rat endotoxin-induced uveitis (EIU). In the present study, we produced EIU in guinea pigs and investigated the effects of betamethasone dipropionate on the EIU.¶Material: Male Hartley guinea pigs were used.¶Treatment: Glucocorticoids were instilled into the eye.¶Method: To elicit EIU, lipopolysaccharide (LPS) was injected into the anterior chamber of the eye. Cell numbers in the aqueous humor after LPS injection were determined by flow cytometry. Prostaglandin E2 (PGE2) production after LPS injection into the anterior chamber was also examined.¶Results: Intracameral injection of LPS (1 μg/eye) induced cell infiltration into the anterior chamber and PGE2 production. Betamethasone dipropionate inhibited cell infiltration and PGE2 production more strongly than betamethasone. These results suggest that betamethasone dipropionate is a potent glucocorticoid in guinea pigs.¶Conclusions: Structure-activity relationships of glucocorticoids in the guinea pig EIU model may differ from those in the rat EIU model.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 102 (1989), S. 161-165 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Porichthys notatus is a common benthic fish found along the Pacific coast of North America. It possesses more than 700 small dermal photophores on its head and trunk. When P. notatus collected in Monterey Bay, California, is injected subcutaneously with norepinephrine, the photophores emit a long-lasting luminescence that is readily visible to the dark-adapted eye. The light emission is due to the oxidation of luciferin (substrate) by molecular oxygen, catalyzed by luciferase. In contrast, P. notatus collected in Puget Sound, Washington, is nonluminous, even though the photophores do not differ ultrastructurally from those of the California fish. The inability of the Puget Sound fish to luminesce is due to lack of luciferin in its photophores. Luminescence capability, however, may be induced in the Puget Sound fish by the oral or intraperitoneal administration of a small amount of luciferin from the tiny luminescent marine ostracod crustacean, Vargula hilgendorfii, suggesting that the origin of luciferin in P. notatus may be from the diet. In this study, specimens of P. notatus were collected over the entire known range of the species, between November 1981 and September 1987, and the presence of luciferin in the photophores determined. The results indicate that there are two populations of P. notatus: a luciferin-deficient, nonluminescent population located north of northern California and a luciferin-containing, luminescent population extending south of Cape Mendocino, California, to Baja California, Mexico. At the northern end of the southern population, a mixture of luminescent and nonluminescent P. notatus was found.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bioluminescent fish Porichthys notatus (plainfin midshipman), has a discontinuous distribution along the Pacific coast of North America. The fish is present from Cape Mendocino southward to Baja California, Mexico, absent off the coast of Oregon, USA, and abundant, northward, in Puget Sound, Washington. Interestingly, the population in Puget Sound lacks the substrate (luciferin) necessary for the luminescence reaction and, despite possessing an otherwise fully functional photophore system, is nonluminescent. The California population of P. notatus is uniformly luminescent south of Monterey Bay, but 15% of the speciments tested from San Francisco Bay and the Gulf of the Farallons have been reported to be nonluminescent. Explanations for nonluminescent midshipman in both Puget Sound and the San Francisco Bay area have focussed on a dietary requirement for luciferin. To gain further insight into reasons for nonluminescence in the San Francisco Bay region, the distribution of bioluminescence in P. notatus was studied from Monterey Bay to Cape Mendocino during 1985. A complex pattern of bioluminescence was found, in which nonluminescent individuals reflected neither a local anomaly in the San Francisco Bay region nor a simple gradient of decreasing luminescence towards the northern end of the range of the California population. Instead, a distinct size-dependent component in luminescence capability of the fish was observed. Aspects of the life history of P. notatus and related factors which might influence the bioluminescence characteristics of this population are discussed.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-2576
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bacterial lipopolysaccharide (LPS) cause airway hyperreactivity in guinea pigs pretreated with metopirone. LPS inhalation resulted in an increase in airway muscarinic reactivity measured by intravenous acetylcholine injection 1–4 h after the inhalation of LPS. The increase of pulmonary capillary permeability was observed 1–24 h after the inhalation of LPS, whereas the increase of leukocytes in bronchoalveolar lavage fluid (BALF) was observed 2 and 24 h after the inhalation of LPS. Increased cells are mainly neutrophil, eosinophil, and macrophage. From the histopathological study, acute mucosal injury and loss of epithelial cilia were observed 1–24 h after the inhalation of LPS. In order to investigate the phlogistic substance in LPS-induced hypereactivity, the roles of collagenase and elastase were investigated. The activities of both enzymes were elevated 2 h after the inhalation of LPS. The inhalation of collagenase and elastase caused bronchial hyperreactivity and increased pulmonary permeability. The combined administration of prednisolone (10 mg/kg/day) and cyclephosphamide (10 mg/kg/day) for five days decreased LPS-induced hyperreactivity, pulmonary capillary increase, collagenase and elastase activities, and the number of nucleated cells in BALF 2 h after the inhalation of LPS. These results indicate the participation of collagenase and elastase in the onset of LPS-induced airway hyperreactivity in guinea pigs.
    Type of Medium: Electronic Resource
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