Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (3)
  • drug interaction  (3)
  • Gene flow  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 50 (1996), S. 203-208 
    ISSN: 1432-1041
    Keywords: Key words Cyclosporine ; Felodipine; dehydrofelodi-pine ; pharmacokinetics ; blood pressure ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: In a double blind, randomised, placebo-controlled, cross-over study 12 healthy male volunteers were allocated to receive felodipine + placebo, cyclosporine + placebo, and felodipine + cyclosporine in order to investigate the interaction between the calcium channel blocker felodipine and cyclosporine as it affects the pharmacokinetics of felodipine, dehydrofelodipine, and cyclosporine, and 24-hour blood pressure measurements. Methods: Single doses of cyclosporine (capsules, 5 mg/kg body weight) and of felodipine (extended release (ER) tablets 10 mg) were given at a 1–2 week interval. Plasma drug concentrations were followed for 2 days after drug intake. Results: For cyclosporine, Cmax was increased after combined treatment (16%) compared to cyclosporine alone, but felodipine did not influence other kinetic parameters of cyclosporine. For felodipine, combined treatment with cyclosporine and felodipine increased AUC and Cmax (58% and 151%, respectively) and lowered mean residence time (24%) significantly compared to felodipine alone. For the metabolite dehydrofelodipine, too, AUC and Cmax were increased after the combined treatment (43% and 94%, respectively). Mean 24-hour systolic and diastolic blood pressures were significantly lower after felodipine, both when felodipine was given alone (121/68 mmHg) and in combination with cyclosporine (122/68 mmHg) compared to cyclosporine alone (127/73 mmHg). Conclusion: A combined single dose of cyclosporine and felodipine in healthy subjects increased the AUC and Cmax of felodipine suggesting a cyclosporine-induced decrease in the first-pass metabolism of felodipine, whereas the AUC of cyclosporine was only slightly increased by felodipine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1041
    Keywords: Propranolol ; ethanol ; drug interaction ; lipid metabolism ; carbohydrate metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of adrenergic beta receptor blockade on the elimination rate of ethanol was studied in seven healthy young men. The studies were performed before and after 14 days of propranolol 240 mg/day: the ethanol was given perorally — 0.8 mg/kg b.w. The blood concentration of ethanol, glucose, lactate and glycerol, and the plasma concentration of free fatty acids and triglycerides were followed in samples from the superior vena cava taken every 20 min for four hours. The splanchnic hepatic blood flow was estimated with a single i.v. injection of indocyanine green. The absorption rate, absorption fraction and elimination rate of ethanol were not changed by propranolol. The splanchnic hepatic blood flow was significantly reduced (mean 19 per cent) during beta receptor blockade. The ethanol-induced change in the concentration of glucose, lactate and free fatty acids was affected by propranolol, the time-concentration curves for glucose and lactate being significantly elevated and that for free fatty acids being significantly reduced. The time-concentration curves for glycerol and triglycerides did not differ in the two studies.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 37 (1989), S. 231-233 
    ISSN: 1432-1041
    Keywords: antipyrine ; terbinafine ; drug metabolism ; drug interaction ; enzyme induction/inhibition ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The potential to inhibit drug metabolism of the new antifungal agent terbinafine has been studied using antipyrine (single oral dose of 10 mg/kg) as a probe drug. In a cross-over study in 8 healthy volunteers, antipyrine was administered prior to, during and after 8 days of oral terbinafine 125 mg b.d. Antipyrine, its major metabolites 4-hydroxyantipyrine (4-OH-AP), 3-hydroxymethylantipyrine (3-OH-CH3-AP) and norantipyrine (Nor-AP) were analyzed by specific HPLC assays in multiple plasma and urine samples. During all three parts of the study, the pharmacokinetics of antipyrine viz. t1/2 (11.7 h), total plasma (38.5 ml·h−1·kg−1) and renal clearance (1.6 ml·h−1·kg−1), and its clearance rates to metabolites (CLM), eg. CLM for 4-OH-AP (12.3 ml·h−1·kg−1), CLM for 3-OH-CH3-AP (4.2 ml·h−1·kg−1) and CLM for Nor-AP (6.7 ml·h−1·kg−1) did not differ from the control values. Thus, all the cytochrome P-450-dependent isozymes involved in the metabolism of antipyrine and many other drugs should not be affected by therapeutic doses of terbinafine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 92 (1996), S. 492-497 
    ISSN: 1432-2242
    Keywords: Key words  Interspecific hybridisation ; Introgression ; Gene flow ; Risk assessment ; Transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract   Different cultivars/transgenic lines of oilseed rape (Brassica napus) were crossed (as females) with different cultivars/populations of Brassica campestris. All cross combinations produced seed, with an average seed set per pollination of 9.8. Backcrossing of selected interspecific hybrids (as females) to B. campestris resulted in a much lower seed set, average 0.7 seed per pollination. In the single backcross progeny where a large enough population (92 plants) was obtained for analysis, 33 B. napus-specific RAPD markers were investigated to determine the extent of transfer of oilseed rape genetic material into this population. Markers were transferred to the backcross generation with frequencies ranging from 26% to 91%. Almost all of the markers (30/33) were transferred in a frequency not significantly different from 50%. Analysis of the pairwise segregation of markers revealed that 23 markers could be assigned to six linkage groups, most probably reflecting six B. napus C-chromosomes. The presence of backcross plants with recombinant genotypes suggests that complex genetic processes can take place during interspecific hybridisation and backcrossing in these Brassica species. The implications of our results for the possible choice of integration sites of transgenes in oilseed rape are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 92 (1996), S. 492-497 
    ISSN: 1432-2242
    Keywords: Interspecific hybridisation ; Introgression ; Gene flow ; Risk assessment ; Transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Different cultivars/transgenic lines of oilseed rape (Brassica napus) were crossed (as females) with different cultivars/populations of Brassica campestris. All cross combinations produced seed, with an average seed set per pollination of 9.8. Backcrossing of selected interspecific hybrids (as females) to B. campestris resulted in a much lower seed set, average 0.7 seed per pollination. In the single backcross progeny where a large enough population (92 plants) was obtained for analysis, 33 B. napus specific RAPD markers were investigated to determine the extent of transfer of oilseed rape genetic material into this population. Markers were transferred to the backcross generation with frequencies ranging from 26% to 91%. Almost all of the markers (30/33) were transferred in a frequency not significantly different from 50%. Analysis of the pairwise segregation of markers revealed that 23 markers could be assigned to six linkage groups, most probably reflecting six B. napus C-chromosomes. The presence of backcross plants with recombinant genotypes suggests that complex genetic processes can take place during interspecific hybridisation and backcrossing in these Brassica species. The implications of our results for the possible choice of integration sites of transgenes in oilseed rape are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Secondary and tertiary hindered amines of the piperidyl type and many other piperidyl compounds can protect various polymers against oxidations initiated by light, heat and ionizing radiation. These amines stabilize by being converted to a series of products which can scavenge with high stoichiometry the main radicals responsible for the oxidative chain. This high stoichiometry results from the cyclical regeneration of the scavenging piperidyl species. The efficiency of the hindered amines as antioxidants in polyolefins is enhanced by their ability to associate with the unstable oxidized domains in which photo- and thermal oxidations will eventually reinitiate. Secondary amines can also slowly decompose intramolecularly hydrogen bonded hydroperoxide groups of the type found in polypropylene. This process may destroy the unstable oxidation product before the hydroperoxide can re-initiate oxidation and also generates another powerful antioxidant, a hydroxylamine. Despite the cyclical regeneration of active piperidyl radical scavengers, side reactions can produce non-scavenging products or even photo-initiators which will progressively accumulate and strangle the antioxidant activities.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2737-2746 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Blends of polystyrene and poly(2,6-dimethyl-1,4-phenylene oxide) that cover the entire compositional range have been subjected to the action of singlet oxygen from microwave discharge, dye-sensitized reaction, and photochemical oxidation. With the applied analytical technique, which consisted of infrared (IR) analysis, including ATR technique and a spectroscopic method combined with chemical analysis for hydroperoxide groups, it was not possible to detect any effect of the singlet oxygen treatment. For that reason singlet oxygen does not appear to be important to the initiation of the photooxidation of these blends. In connection with photochemical oxidation the interaction observed between the two components probably involves energy transfer from PS to PPO. This interaction results in the enhancement of reactions in PPO that lead to greater carbonyl group formation and crosslinking. Simultaneously, the probability of chain scission in the PS is lowered with increased PPO content, found by determining the changes in the molecular weights.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 2765-2771 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By fluorescence spectroscopy it is possible to investigate some of the photophysical processes, particularly the energy transfer, that occur during the photo-oxidative degradation of polystyrene (PS), poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), and homogeneous blends of these. In connection with the irradiation, a part of the absorbed energy is transferred from excited phenyl groups in PS to PPO. The decrease in PS excimer fluorescence at 319 nm by admixture of PPO is greater than expected from the absorption of PPO at the excitation wavelength. A radiative energy transfer is suggested from PS to PPO which absorbs at 319 nm. Energy transfer also occurs to groups formed during photo-oxidation. The quenching of PS excimer fluorescence during the process has been studied for both the homopolymer and the blends, and in all cases the reactions occurring during photo-oxidation result in marked quenching at 319 nm.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...