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  • 1
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In the rat pineal gland noradrenaline is released in large quantities from sympathetic nerve endings at the onset of darkness, thereby driving rhythmic melatonin synthesis with elevated levels at night-time. Upon release, noradrenaline interacts with postsynaptic β1-adrenergic receptors to activate the cyclic AMP signalling pathway. Well characterized third messengers of this signalling cascade affect cyclic AMP-inducible genes that are crucially involved in initiation, maintenance and termination of hormone production. Among these third messengers are CREB (cyclic AMP responsive element binding protein) as an activating and ICER (inducible cyclic AMP early repressor) as an inhibitory transcription factor. Because a cyclic AMP-inducible promoter element is present on the β1-adrenergic receptor gene, the expression of the receptor itself may be under control of the cyclic AMP-signalling pathway. By in situ hybridization, Northern blot analysis and RT-PCR we demonstrate a day/night rhythm in β1-adrenergic receptor mRNA in the rat pineal gland with elevated levels during the dark period. As this rhythm persists, under constant darkness but is abolished upon removal of the sympathetic innervation, it is truly circadian. A marked day/night difference in the levels of β1-adrenergic receptor mRNA becomes evident only after postnatal day 10, coinciding with the appearance of a functional cyclic AMP signalling pathway in the rat pineal gland. Furthermore, targeting ICER expression by transfection of pinealocytes with an antisense ICER construct, clearly indicates that the levels of the β1-adrenergic receptor mRNA are regulated by the cyclic AMP-signalling pathway in a feedback mechanism.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-0423
    Keywords: Key words Deep lamellar keratoplasty • Penetrating keratoplasty • Guided trephine system • Microkeratome ; Schlüsselwörter Tiefe lamelläre Keratoplastik • Perforierende Keratoplastik • Geführtes Trepan-System • Mikrokeratom
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Fragestellung: Obwohl die tiefe lamelläre Keratoplastik (TLKP) im Vergleich zur perforierenden Keratoplastik (PKP) weniger invasiv ist, ist diese Technik kaum verbreitet. Wir untersuchten, ob die von uns durchgeführte Technik der TLKP eine stabile Visusverbesserung ermöglicht. Patienten und Methode: Bei 33 Augen mit superfizieller Hornhautpathologie oder fortgeschrittenem Keratokonus wurde eine 8,0 mm TLKP durchgeführt. Das Spendergewebe war geeignet für eine PKP. Die Spenderscheibe wurde auf der Vorderkammerbank des geführten Trepan-Systems (GTS) gewonnen. Die Empfängerhornhaut wurde auf eine Tiefe von 680 μm vortrepaniert und das Empfängerbett wurde manuell präpariert. Nach Entfernung des Endothels wurde das Transplantat in ganzer Dicke übertragen und mit einer 10 × 0 doppelten anti-torque-Naht eingenäht. Postoperativ wurden Kortison-Antibiotika-Augentropfen gegeben. Ergebnisse: Der postoperative Verlauf war in der gesamten Serie ohne Komplikationen. Der mittlere bestkorrigierte Brillenvisus (BSCVA) lag präoperativ bei 0,29 ( ± 0,21), 0,1 ( ± 0,11) nach 1 Woche, 0,33 ( ± 0,14) nach einem Monat, 0,5 ( ± 0,13) nach 6 Monaten, 0,61 ( ± 0,16) nach einem Jahr und 0,63 ( ± 0,16) nach 2 Jahren. Es wurden 2 Untergruppen beobachtet: in einer Gruppe (87 %) verbesserte sich der BSCVA auf einen durchschnittlichen Wert von 0,67 ( ± 0.07) nach 6 Monaten. In der zweiten Gruppe (BSCVA ≤ 0,25 nach 6 Monaten) verblieb der mittlere BSCVA auf 0,2 ( ± 0.04) nach einem Jahr. Der mittlere Astigmatismus betrug präoperativ 2,93 ( ± 1,62) Dpt, 2,69 ( ± 1,18) dpt nach 1 Monat, 2,09 ( ± 1,07) dpt nach 1 Jahr und 2,22 ( ± 1,11) dpt nach 2 Jahren. Es traten keine Abstoßungsreaktionen auf. Schlußfolgerung: Die hier vorgestellte Technik gewährleistet eine optimale Paßform von Spenderscheibe und Transplantatbett. Die Trennung von Empfänger- und Spenderstroma verhindert eine Heilung im Interface. Die TLKP ist ein sicheres Verfahren und eröffnet bei superfizieller Hornhautpathologie eine echte Alternative zur PKP.
    Notes: Background: Despite the fact that deep lamellar keratoplasty (DLKP) is less invasive than to penetrating keratoplasty (PKP), this procedure is rarely performed. We therefore investigated whether or not the DLKP technique we employed can achieve stable improvement of visual acuity. Materials and methods: Thirty-three eyes underwent TLKP for treatment of superficial corneal pathology. The donor tissue transplanted was suitable for PKP. The donor lenticule was obtained on the artificial chamber of the guided trephine system (GTS). The recipient cornea was trephined with the same trephine to a depth of 680 μm. Manual dissection was performed with a bevel-up blade. The donor lenticule with the endothelium peeled off was then sutured in with a 10 × 0 nylon double-running antitorque suture. Cortisone-antibiotic eye drops were administered postoperatively. Results: Throughout the series no complications occurred. The mean best corrected visual acuity (BSCVA) over glasses was 0.29 ( ± 0.21) preoperatively, 0.1 ( ± 0.11) at 1 week, 0.33 ( ± 0.14) at 1 month, 0.5 ( ± 0.13) at 6 months, 0.61 ( ± 0.16) at 1 year and 0.63 ( ± 0.15) at 2 years. Clinically, we observed two subpopulations. In the first group of 87 % of the cases, mean BSCVA was 0.67 ( ± 0.07) at 6 months. The remaining cases (BSCVA ≤ 0.25 at 6 months) achieved a mean BSCVA of only 0.2 ( ± 0.04) at 1 year. Mean corneal astigmatism measured 2.93 D ( ± 1.62) preoperatively, 2.69 D ( ± 1.18) at 1 month, 2.09 D ( ± 1.07) at 1 year, and 2.22 D ( ± 1.11) at 2 years. We did not observe any graft rejection. Conclusion: The technique reported for DLKP provides excellent matching of donor lenticule and recipient bed. Separation of donor and recipient stroma prevents interface healing. DLKP appears to be a safe procedure for the surgical treatment of superficial corneal pathology and may offer a clinically applicable alternative to PKP.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solid state electrochemistry 2 (1998), S. 413-419 
    ISSN: 1433-0768
    Keywords: Key words Abrasive stripping voltammetry ; X-ray powder diffractometry ; Manganates ; Solid state electrochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Abrasive stripping voltammetry is applied in order to characterize barium and strontium manganates-(V) and -(VI) in solid state phases. Voltammetric reduction peak potential values of KBaMnO4, Ba3(MnO4)2, Ba3(MnO4)2− x (BO3) x (x=0.031(1)), Ba5(MnO4)3OH, Ba5(MnO4)3Cl, Sr5(MnO4)3OH and BaMnO4 are shown to be proportional to the corresponding average Mn-O distances, which were determined from X-ray powder diffractometric data through Rietveld refinement analyses.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solid state electrochemistry 3 (1999), S. 117-120 
    ISSN: 1433-0768
    Keywords: Key words Electrochemistry ; Manganates(V) ; Mn oxides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Potential pulse chonoamperometry was applied to immobilized microparticles of manganates(V) and MnO2 in order to compare the nature of the rate determining step in their reduction. Manganates(V) were found to be reduced by an irreversible one-electron surface reaction, whereas MnO2 reduction is controlled by a reversible reaction coupled to solid-state diffusion. The key importance of the coordination preferences of reacting metal ions on the surface layer of the solid particles is also discussed with respect to known mechanisms of electrochemical dissolution of Fe and Cr oxides.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1433-0423
    Keywords: Key words Scanning laser tomography ; Scanning laser ophthalmoscope ; Fundus perimetry ; Optic disc type ; Schlüsselwörter Scanning-Laser-Tomographie ; Scanning-Laser-Ophthalmoskop ; Fundusperimetrie ; Papillentyp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Fragestellung: Wir wollten herausfinden, ob die Form der Papillenoberfläche die Lage der Außengrenzen bzw. die Größe des blinden Flecks beeinflußt. Patienten und Methode: Wir untersuchten 10 Augen mit einem temporalen parapapillaren Konus (und flacher temporaler Exkavation der Papille) und als Kontrollgruppe 6 Augen ohne Konus. Die Kontrollaugen wiesen keine oder eine ,,normale`` zentrale Exkavation auf. Mittels Fundusperimetrie mit dem Scanning-Laser-Ophthalmoskop (SLO) untersuchten wir die Lichtunterschiedsempfindlichkeit (LUE) entlang des horizontalen Meridians der Papillen. Die Oberflächenform der Papillen wurde mit dem Heidelberg-Retinatomographen (HRT) bestimmt. Ergebnisse: Stimuli mit hoher Leuchtdichte (Goldmann IV, 4 dB) wurden in den 10 Augen mit Konus nur bis 0,8° innerhalb des temporalen Rands des Konus, aber bis 1,9° innerhalb des nasalen Papillenrands gesehen. Diese Papillen hatten immer einen prominenten nasalen Papillenrand im Gegensatz zu einer flachen Exkavation temporal. Eine solche nasotemporale Asymmetrie, weder bezüglich der Struktur noch bezüglich der Funktion, konnte bei keinem der 6 Kontrollaugen nachgewiesen werden. Schlußfolgerung: Die Größe eines Skotoms hängt auch von der Oberflächenform des getesteten Gebiets ab. Prominente Anteile der Papille erscheinen weniger blind als flache Anteile, wahrscheinlich weil sie Licht auf empfindliche benachbarte Netzhautanteile streuen.
    Notes: Background: We wanted to find out whether the borders of the blind spot depend on the surface topography of the optic disc and its surrounding area. Patients and methods: We therefore examined ten eyes with parapapillary atrophy adjacent to the temporal side of the disc. Fundus perimetry was performed under direct fundus control using a Rodenstock scanning laser ophthalmoscope. We examined the horizontal meridian of the optic discs in 0.5° steps using Goldmann IV-stimuli with 10 different degrees of brightness and the Goldmann stimulus I, 0 dB (greatest luminance). Six eyes with symmetric, ,,normal`` excavation served as controls. Optic disc topography was measured with the Heidelberg Retina Tomograph (HRT). Results: Stimuli with a large luminance power (Goldmann IV, 4 dB) were seen up to 0.8° centrally (i. e., towards the optic disc center) from the temporal edge of the parapapillary atrophy, but up to 1.9° centrally from the nasal optic disc border (P〈0.01). Horizontal HRT section profiles of the optic disc consistently showed prominent nasal disc borders contrasting with a shallow excavation within the temporal parapapillary atrophy. In all six subjects with a normally shaped disc there was no such ,,naso-temporal asymmetry.`` Conclusions: The size of scotomas depends on the surface topography of the tested area. The prominent nasal part of the optic disc appears less ,,blind`` than the shallow temporal part, probably due to more intensive light scattering by the prominent nasal part of the disc.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2277
    Keywords: Key words Chronic anemia ; heart transplantation ; prognosis ; Heart transplantation ; chronic anemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The clinical relevance of mild chronic anemia in patients after heart transplantation (HTX) has not yet been demonstrated. Forty-five outpatients who had undergone HTX 2–99 months prior to investigation and who had not received blood transfusions or erythropoietin (EPO) before data acquisition were observed over a period of 37 months. Anemia was found in 36 of the 45 patients and was normocytic, normochromic, and slightly anisocytotic (coefficient of variation = 16 ± 2, normal 11.5–14.5). Anemic patients showed elevated EPO levels, whereas in nonanemic patients EPO levels were normal. Survival after HTX differed significantly in anemic and nonanemic patients (P 〈 0.02), with 100 % survival in the nonanemic and 85 % in the anemic group. Chronic anemia in patients after HTX shows a typical pattern. Even when mild, anemia in patients after HTX seems to be of prognostic value and thus might be an indicator of chronic disorders.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0878
    Keywords: Key words: Pinealocytes ; Cyclic AMP responsive element binding protein (CREB) ; Phosphorylated CREB ; β-Adrenergic receptor ; S-antigen (arrestin) ; Transcription factors ; Cell culture (Rat ; Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In the present study we investigated whether norepinephrine, which stimulates melatonin biosynthesis in the mammalian pineal organ, causes phosphorylation of the cyclic AMP responsive element binding protein (CREB) in rat pinealocytes. Cells isolated from the pineal organ of adult male rats and cultured on coated coverslips were treated with norepinephrine, β- or α1-adrenergic agonists for 1, 5, 10, 20, 30, 60 or 300 min and then immunocytochemically analyzed with an antibody against phosphorylated CREB (p-CREB). Treatment with norepinephrine or β-adrenergic agonists resulted in a similar, time-dependent induction of p-CREB immunoreactivity, exclusively found in cell nuclei. The α1-adrenergic agonist phenylephrine did not induce p-CREB immunoreactivity at low doses (0.1 μM) or when high doses (10 μM) were applied in combination with a β-antagonist (propranolol, 0.1 μM). This indicates that induction of CREB phosphorylation is elicited by β-adrenergic receptor stimulation. The response was first seen after 10 min and reached a maximum after 30 to 60 min when more than 90% of the cells displayed p-CREB immunoreactivity. The intensity of the p-CREB immunoreactivity showed marked cell-to-cell variation, but nearly all immunoreactive cells were identified as pinealocytes by double-labeling with an antibody against the S-antigen, a pinealocyte-specific marker. The results show that norepinephrine stimulation induces p-CREB immunoreactivity by acting upon β-adrenergic receptors in virtually all rat pinealocytes. The findings support the notion that phosphorylation of CREB is a rather rapid and uniform response of pinealocytes to noradrenergic stimulation and thus is an important link between adrenoreceptor activation and subsequent gene expression in the rat pineal organ.
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  • 8
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Cyclic AMP responsive element binding protein (CREB) ; Phosphorylated CREB ; β-Adrenergic receptor ; S-antigen (arrestin) ; Transcription factors ; Cell culture (Rat, Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the present study we investigated whether norepinephrine, which stimulates melatonin biosynthesis in the mammalian pineal organ, causes phosphorylation of the cyclic AMP responsive element binding protein (CREB) in rat pinealocytes. Cells isolated from the pineal organ of adult male rats and cultured on coated coverslips were treated with norepinephrine, β- or α1 agonists for 1, 5, 10, 20, 30, 60 or 300 min and then immunocytochemically analyzed with an antibody against phosphorylated CREB (p-CREB). Treatment with norepinephrine or β-adrenergic agonists resulted in a similar, time-dependent induction of p-CREB immunoreactivity, exclusively found in cell nuclei. The α1 agonist phenylephrine did not induce p-CREB immunoreactivity at low doses (0.1 μM) or when high doses (10 μM) were applied in combination with a β-antagonist (propranolol, 0.1 μM). This indicates that induction of CREB phosphorylation is elicited by β-adrenergic receptor stimulation. The response was first seen after 10 min and reached a maximum after 30 to 60 min when more than 90% of the cells displayed p-CREB immunoreactivity. The intensity of the p-CREB immunoreactivity showed marked cell-to-cell variation, but nearly all immunoreactive cells were identified as pinealocytes by double-labeling with an antibody against the S-antigen, a pinealocyte-specific marker. The results show that norepinephrine stimulation induces p-CREB immunoreactivity by acting upon β-adrenergic receptors in virtually all rat pinealocytes. The findings support the notion that phosphorylation of CREB is a rather rapid and uniform response of pinealocytes to noradrenergic stimulation and thus is an important link between adrenoreceptor activation and subsequent gene expression in the rat pineal organ.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of clinical monitoring and computing 12 (1995), S. 141-145 
    ISSN: 1573-2614
    Keywords: coding medical concepts ; diagnoses ; electronic patient record ; ICD-9 ; quality of documentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Medicine
    Notes: Abstract In clinical routine there is a growing need to encode medical concepts with available standard coding systems. The coding process can be time consuming and may significantly add to daily paperwork, particularly regarding patients with multiple diagnoses and in busy clinical environments with a high turnover of patients. We have developed a generic computerised encoding tool — the PADS encoder — to ensure rapid, correct and complete coding of diagnoses in daily routine. The tool is integrated into an electronic patient record system (PADS, Patient Archiving & Documentation System) and takes full advantage of the user friendly Macintosh interface. The tool was tested in a controlled experiment by 18 clinicians who encoded a total of 666 medical concepts in each protocol (study protocol vs. control). The following positive findings were significantly associated with the use of the computerised coding tool: - the number of correctly encoded medical concepts was higher (99.55% vs. 86.1%) - coding errors were lower (0% vs. 10.81%) - more modifier codes were encoded correctly (increase by up to 43%) - less coding errors were made (decrease by up to 43%) - the overall rate of correctly encoded and complete main and modifier codes was increased by 31.27% (97.29% vs. 66.02%) - coding time was reduced by 50% This paper presents data to suggest that a computerised coding tool can produce more complete data of higher quality and can save time compared with the traditional approach to encode medical concepts.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    International ophthalmology 20 (1996), S. 263-268 
    ISSN: 1573-2630
    Keywords: myelinated nerve fibers ; leukocoria ; myopia ; papilla leporina ; development of myopia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: To find correlations between the extent of myelinated nerve fibers with refraction anomalies. Method: Searching for myelinated nerve fibers in the slide collection of the University Eye Hospital Freiburg we found 13 patients. We distinguished between eyes with wide-spread myelinated nerve fibers located on and around the optic disc which extended to the midperiphery of the retina (6 patients; Group A) and eyes with circumscribed myelinated nerve fibers, localized merely around the optic disc (7 patients, Group B). In Group A myelinated nerve fibers spared the macula area, but were localized very close to the macula. Color fundus photographs were taken by the Zeiss Fundus camera SK50 (30 ° and 50 ° picture size) and by the Olympus Fundus camera GRC-W (same picture size). Results: The myelinated nerve fibers were found to be unilateral in all 13 patients. In all 6 patients of Group A, a strabismus was present. The affected eye had a severe amblyopia and a unilateral myopia (- 5.75 to - 25.0 D.). The nonaffected fellow eye showed a normal visual acuity with no or only a slight refractive error. In the 7 patients of the Group B, no strabismus was present and a normal or a slightly decreased visual acuity of the affected eye was found. No distinct refractive error was present in the affected and non-affected eyes of this group. Conclusions: Myopia only occurred in eyes with wide-spread myelinated nerve fibers but not in eyes with circumscribed myelinated nerve fibers. We assume that myelinated nerve fibers, if wide-spread, cause myopia.
    Type of Medium: Electronic Resource
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