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101.
Ralph Bültmann Bernd Driessen Jorge Gonçalves Klaus Starke 《Naunyn-Schmiedeberg's archives of pharmacology》1995,351(5):555-560
The effect of Evans blue on nucleotide breakdown, nucleotide-evoked contractions and electrically evoked contractions, overflow of ATP and overflow of tritium (after labelling with [3H]-noradrenaline) was studied in rat vas deferens. Pieces of vas deferens degraded 83 to 85% of added ATP, ADP and 2-methylthio ATP (all 100 M) over 30 min. Evans blue (100 M) reduced this degradation to 22 to 26%. Nucleotides elicited contraction with potency declining in the order , \-methylene ATP > 2-methylthio ATP > ATP > ADP. Evans blue (100 M) shifted the concentration-response curve of , \-methylene ATP to the right and increased the maximum. Concentration-response curves of ATP, ADP and 2-methylthio ATP, in contrast, were shifted to the left and responses were much potentiated. In the presence of Evans blue, the rank order of potency was ATP > 2-methylthio ATP > , \-methylene ATP > ADP. Electrical field stimulation (100 pulses at 10 Hz) elicited contraction and an overflow of tritium and ATP. Evans blue (100 M) did not alter the contraction and the evoked overflow of tritium but increased 24-fold the evoked overflow of ATP. The results indicate that Evans blue may serve as an — albeit impure — ecto-nucleotidase inhibitor in functional experiments. Such experiments demonstrate that the low potency of ATP (and also ADP and 2-methylthio ATP) in eliciting contraction, and the small size of the overflow of ATP upon sympathetic nerve stimulation, are due to rapid breakdown. 相似文献
102.
Astrid Hagelüken Rahel Burde Bernd Nürnberg Rainer Harhammer Armin Buschauer Roland Seifert 《Naunyn-Schmiedeberg's archives of pharmacology》1995,351(3):305-308
Formyl peptides activate superoxide anion (O2
–) formation in human neutrophils and in HL-60 cells via pertussis toxin (PTX)-sensitive guanine nucleotide-binding proteins (G-proteins), and histamine (HA) mediates inhibition of O2
– formation via H2-receptors. We have studied the effects of lipophilic arpromidine-derived guanidines, which are potent, full H2-receptor agonists in the guinea pig atrium, on O2
– formation and on activation of G-proteins in HL-60 membranes and on purified G-proteins. We have also studied the effects of a HA trifluoromethyl-toluidide derivative (HTMT), a cationic-amphiphilic HA derivative which activates O2
– formation in HL-60 cells through a mechanism which is independent of known HA receptor subtypes, on G-protein activation. Guanidines, at concentrations, up to 30 mol/l inhibited and, at concentrations above 30 mol/l, enhanced formyl peptide-induce O2
– formation in neutrophils. In HL-60 cells, guanidines per se activated O2
– formation. The stimulatory effects of guanidines on O2
– formation were not inhibited by H1- or H2-receptor antagonists. In HL-60 membranes, guanidines and HTMT, activated high-affinity GTPase in a PTX-sensitive manner. These substances also increased GTP hydrolysis effected by transducin and Gi/Go-proteins. Our data suggest that lipophilic guanidines and HTMT may act as receptor-independent activators of PTX-sensitive G-proteins, resulting in stimulation of O
2
–
formation. 相似文献
103.
Kirsten Hierholz Wolfgang Baus Klaus Müller-Sievers Bernd Kober 《Strahlentherapie und Onkologie》1999,31(4):616-619
Hintergrund: Ein Multileafkollimator stellt durch die Vielzahl der Lamellen sehr viel höhere Ansprüche an die Konstanzprüfverfahren als ein konventionelles Blendensystem. Zur täglichen Kontrolle der Lamellenpositionierung wird ein Qualitssicherungskonzept vorgestellt. Methode: Zwei Feldkonfigurationen, die bei maximaler Öffnung der Blockblenden sowohl maximale Öffnung als auch "Overtravel" einzelner Lamellen enthalten, werden in täglichem Wechsel online vom Verifikationssystem zum Linearbeschleuniger übertragen. Im Lichtfeld des Linearbeschleunigers erfolgt eine visuelle Kontrolle der Lamellenpositionen mit Hilfe eines speziellen Prüfkörpers. Abschließend wird die Lamellenpositionierung mittels eines Electronic-Portal-Imaging-Systems dokumentiert und nach Überlagerung eines Gitters mit einer Referenzaufnahme verglichen. Ergebnisse: Die Methode stellt eine schnelle und effektive Möglichkeit dar, die Funktionsfähigkeit des gesamten Systems durch Simulation des "Routinebetriebs" zu überprüfen. Schlußfolgerung: Der Arbeits- und Zeitaufwand für die Qualitätssicherung an einem Multileafkollimator unterscheidet sich nur unwesentlich von dem eines konventionellen Blendensystems. Background: In comparison to a conventional collimator, a multileaf collimator demands a great deal of quality assurance procedures due to its large number of leaves. A concept for daily quality assurance is presented, mainly concerning the positioning accuracy of the leaves. Material and Methods: Two leaf configurations including maximal opening as well as overtravel of single leaves, at a maximal opening of the jaws, are transmitted online in daily exchange from our record- and verify system to the linac. Aiming at a special test phantom a visual control of the positioning accuracy is performed. The leaf positioning is documented by an electronic portal imaging system and is compared with a reference shot by superposition of a grid. Results: This method of quality assurance offers a fast and effective possibility to guarantee the proper function of the whole system by simulating the routine treatment situation. Conclusions: Compared to a conventional collimator only a slightly greater workload is needed for quality assurance of a multileaf collimator. 相似文献
104.
Keratinocytes were obtained from three patients with chronic full-thickness ulcers of different aetiologies. The cells were isolated, cultured and then seeded on to a membrane composed of benzylester hyaluronic acid. Once the keratinocytes had become subconfluent, the keratinocyte-containing matrix sheets were then applied as autologous grafts to the patients' ulcers. Results indicate that autologous grafting of keratinocytes cultured on benzylester hyaluronic acid membranes provides improved graft handling, reduces total time required for tissue cultivation and enhances cellular vitality because of the possibility of grafting at a subconfluent non-differentiated stage. 相似文献
105.
This study examined the effect of neurotrophin-3 (NT-3) on neurite outgrowth and apoptosis of chicken neural plate explants prior to neural tube formation. In situ hybridization revealed that mRNA for the full-length (catalytic) NT-3 receptor, TrkC, was present in, and limited to, the neural plate (including the neural folds) coincident with its formation. Neural plate explants were maintained in vitro on a collagen gel under serum-free conditions in the presence or absence of exogenous NT-3 and/or an antibody to NT-3. In the absence of exogenous NT-3, explants exhibited neurite outgrowth after several days in vitro; apoptotic cells were also seen after 2 days in vitro. This does not appear to be due to endogenous NT-3, since the total number of neurites or apoptotic cells was unchanged if explants were exposed to an NT-3 antibody for the entire culture period. In the presence of exogenous NT-3, neural plate explants exhibited a dose-dependent statistically significant increase in the total number of neurites as compared to explants maintained under control conditions, as well as a statistically significant increase in apoptosis. These NT-3 effects were blocked by an NT-3 antibody. In contrast, NT-3 had no effect on the length of neurites. These findings suggest that NT-3 may play a role during early neural development in vivo. 相似文献
106.
Thybusch-Bernhardt A Schmidt C Küchler T Schmid A Henne-Bruns D Kremer B 《World journal of surgery》1999,23(5):503-508
Quality of life (QOL) in patients with gastric cancer who underwent total gastrectomy has so far not been studied using the
EORTC QLQ-C30 (Quality of Life Core Questionnaire of the European Organization for Research and Treatment of Cancer) as a
standardized European QOL instrument. The aim of this study was to evaluate the effect of radical procedures such as extensive
lymph node resection and combined resection of adjacent organs on patients' QOL. From 1992 to 1996, 152 patients underwent
total gastrectomy. All patients alive on July 1, 1996 were included in the study (77/152). For assessing QOL, the EORTC QOL
questionnaire QLQ-C30 version 2.0 and a validated gastric cancer module were sent home to the patients for self-completion.
The response rate was 91%. It was possible to evaluate the questionnaires of 62 patients who had undergone resection with
curative intent including 13 extended gastrectomies (21%). Of the 62 resections, 50 were combined with D2 lymphadenectomy
(80.6%). The global health status was not negatively influenced by D2 lymphadenectomy and extended gastrectomy. Patients with
splenectomy were more affected by treatment than patients without splenectomy. Radical gastrectomy combined with D2 lymphadenectomy
is the treatment of choice for gastric cancer patients, concerning not just survival but QOL as well. 相似文献
107.
Penetration of ciprofloxacin, norfloxacin and ofloxacin into the aqueous humor using different topical application modes 总被引:3,自引:0,他引:3
R. Beck Jan van Keyserlingk Ulrike Fischer Rudolf Guthoff Bernd Drewelow 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1999,237(2):89-92
· Background: A prospective study was undertaken to determine the transcorneal penetration of three topically applied fluoroquinolones
into aqueous humor. · Methods: Cataract patients (n=224) preoperatively received topically applied gyrase inhibitors (0.3% ciprofloxacin, 0.3% norfloxacin, 0.3% ofloxacin) in
two different application modes. In application mode I, patients received on the day before operation 3×1 eye drop at 2-h
intervals, and on the day of operation 3 drops at 1-h intervals. In application mode II, patients received 9 drops at 15-min
intervals on the day of operation only. Just before cataract surgery 50–100 μl aqueous humor was aspirated and stored at –80
°C. The HPLC method was used for measuring the concentration. · Results: The highest concentrations of all tested antibiotics
were measured after the mode of application in which one drop was given every 15 min between 06:00 and 08:00 hours before
operation. In this mode, ciprofloxacin achieved a mean aqueous level of 379.8±327.8 μg/l (range 33–1388 μg/l), norfloxacin
182.1±118.1 μg/l (range 38–480 μg/l) and ofloxacin 563.9±372.1 μg/l (range 64–1455 μg/l). These mean concentration are all
above the MIC90 of gram-negative bacteria like Proteus mirabilis and Escherichia coli. In some cases the concentrations of ciprofloxacin and ofloxacin, but never norfloxacin, reached therapeutic values above
the MIC90 of Staphylococcus aureus and Staphylococcus epidermidis · Conclusions: The mean concentration value of 0.3% ciprofloxacin and of 0.3% ofloxacin in the aqueous humor reached the MIC90 values of the frequently occurring gram-positive and gram-negative bacteria. Of the currently available topical fluoroquinolones,
ofloxacin achieved the highest aqueous humor concentration. Considering the higher antimicrobial activity of ciprofloxacin,
both ciprofloxacin and ofloxacin may be useful ophthalmic agents in antibacterial management, but they are not efficient against
Streptococcus pneumoniae and Pseudomonas aeruginosa.
Received: 8 September 1997 Revised version received: 19 March 1998 Accepted: 8 April 1998 相似文献
108.
Dr. Rolando Grave de Peralta Menendez Sara L. Gonzalez Andino Bernd Lütkenhöner 《Brain topography》1996,9(2):117-124
Summary This paper introduces the concept of the resolution matrix as the basis for an objective theoretical comparison of distributed linear inverse solutions to the neuroelectromagnetic inverse problem. In particular, we describe how figures of merit derived from the resolution matrices can be represented graphically to evaluate merits and shortcomings of the different solutions. The use of the figures of merit is illustrated with two solutions that consider minimal a priori information about the generators: Classical Minimum Norm and Backus Gilbert. We recommend to start any analysis with the individual exploration of the resolution kernel for each grid point or at least for those points where the activity is likely to occur. This analysis might help in selecting the optimal inverse for the sources that are supposed to be active in the process under study.This work was supported by a grant from the Deutsche Forschungsgemeinschaft (Klinische Forschergruppe Biomagnetismus and Biosignalanalyse). Partial support was received from Swiss National Foundation grant 4038-044081/1. 相似文献
109.
Frank Rösch Hans Herzog Cornelius Plag Bernd Neumaier Ulrike Braun Hans-Willhelm Müller-Gärtnere Gerhard Stöcklin 《European journal of nuclear medicine and molecular imaging》1996,23(8):958-966
Yttrium-90 is used for palliative therapy for the treatment of skeletal metastases, but because it is a pure - emitter, data on the pharmacokinetics and radiation doses to metastases and unaffected organs are lacking. To obtain such data, the present study employed yttrium-86 as a substitute for90Y, with detection by positron emission tomography (PET). The study compared the properties of two different86Y complexes —86y-citrate and86Y -ethylene diamine tetramethylene phosphonate (EDTMP) — in ten patients with prostatic cancer who had developed multiple bone metastases (the ten patients being divided into two groups of five). Early dynamics were measured up to 1 h post injection (p.i.) over the liver region, followed by subsequent whole-body PET scans up to 3 days p.i. Absolute uptake data were determined for normal bone, bone metastases, liver and kidney. Radiation doses were calculated according to the MIRD recommendations. Based on the pharmacokinetic measurements of the distribution of the86Y complexes, it was possible to calculate radiation doses for the bone metastases and the red bone marrow delivered by complexes containing90Y. In 1 cm3 of bone metastasis, doses of 26±11 mGy/MBq and 18±2 mGy/MBq were determined per MBq of injected90Y- citrate and90Y- EDTMP, respectively. The doses to the bone marrow were 2.5±0.4 mGy/MBq for90Y- citrate and 1.8±0.6 mGy/MBq for90Y-EDTMP.86Y and PET provide quantitative information applicable to the clinical use of90Y. This method may also be useful for the design of other90Y radiopharmaceuticals and for planning radiotherapy dosages. 相似文献
110.
Florian Guthmann Bernd Mayer Doris Koesling Walter R. Kukovetz Eycke Böhme 《Naunyn-Schmiedeberg's archives of pharmacology》1992,346(5):537-541
Summary Soluble guanylyl cyclase partially purified from bovine and human platelets was characterized with antibodies raised against synthetic peptides corresponding to different sequences of the 1- and 1-subunits of the bovine lung enzyme. On immunoblots, the platelet guanylyl cyclase was recognized by the four antisera used, with the exception of an antiserum against the C-terminus of the 1-subunit which did not react with the human platelet but with the bovine platelet 1-subunit. Furthermore the human platelet 1-subunit exhibited a slightly lower molecular mass than the bovine protein. The C-terminal antibodies precipitated native platelet and lung guanylyl cyclase activity. In contrast an antibody against a peptide out of the putative catalytic domain, which is highly conserved between all guanylyl cyclases sequenced so far, did not precipitate native guanylyl cyclase, although it recognized both subunits on immunoblots, suggesting that the respective amino acid sequence is located in an inner site of the protein.Abbreviations GCpep2
YGPEVWEDIKKEA (one letter code)
- GCpep3
SRKNTGTEETEQDEN
- GCpep5
VYKVETVGDKYMTVSGLP
- GCpep8
KKDVEEANANFLGKASGID
- TBS-T
Tris-buffered saline, containing 0.0501o Tween 20
Correspondence to E. Böhme at the above address 相似文献