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D Förster

Publications and source records attributed to D Förster.

At least 19 recordsLinked to original sources
PubMed1990

N-6 and N-3 PUFA in liver lipids, thromboxane formation and blood pressure from SHR during diets supplemented with evening primrose, sunflowerseed or fish oil.

Spontaneously hypertensive rats (SHR) after weaning (at 4 weeks of age) were fed diets supplemented with either sunflowerseed oil (SO), evening primrose oil (EPO), fish oil (FO) or EPO + FO (50%: 50%, v/v) for 22 weeks. A diet with commercially available pellets served as control. Systolic blood pressure was significantly lower in the dietary groups receiving FO, EPO and FO + EPO, the former being most effective. In liver triglycerides (TG) EPO resulted in a markedly increased percentage of linoleic acid (LA; C 18:2, n-6), alpha-linolenic acid (alpha-LNA; C 18:3, n-6) and especially of arachidonic acid (AA; C 20:4, n-6), whereas the long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA; C 20:5, n-3) and docosahexaenoic acid (DHA; C 22:6 n-3), were depressed to undetectable and significantly lower levels, respectively. In liver phosphatidylcholine (PC) and phosphatidylethanolamine (PE) only slight changes of LA and AA were observed. Feeding of FO led to a significant rise of EPA and DHA in liver TG, PC and PE at the expense of n-6 PUFA (except LA in PC and PE). With a combination of both EPO and FO a significant increase of EPA and DHA, but on lower levels as compared to FO alone, was associated with a significant rise of LA, but with a slight decline of AA as compared to the control animals. Nevertheless, the levels of AA in the group fed EPO + FO were still higher than in the FO-group. In the SO-group the increase of LA was even higher when compared with the EPO-group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Bactericidal activity of ciprofloxacin, norfloxacin and ofloxacin in serum and urine after oral administration to healthy volunteers.

A 200 mg oral dose of ciprofloxacin, norfloxacin or ofloxacin was administered to six healthy male volunteers in a three way cross-over study in order to examine the kinetics in humans in relation to the bactericidal activity in serum and urine. Serum concentrations for ciprofloxacin were similar to norfloxacin and lower than ofloxacin. Despite this fact, ciprofloxacin showed the highest serum bactericidal titers compared to norfloxacin and ofloxacin when serum-resistant Escherichia coli C14 was used as a test organism. These results correlate with observations from timekill curve studies in human whole blood, where ciprofloxacin showed superior bactericidal activity compared to norfloxacin or ofloxacin. The amounts of unchanged drug excreted in urine (48 h period) were found to be 35%, 24% and 77% for ciprofloxacin, norfloxacin and ofloxacin respectively, indicating different excretion kinetics. The volumes of urine excreted in the different collection periods were comparable for the three drugs tested. Mean urine concentrations for ciprofloxacin were higher during the 0 to 4 h collection periods, whereas ofloxacin was excreted into the urine over a longer time period. Measurements of urine bactericidal activity showed that ciprofloxacin had the highest titers during the early collection periods, whereas the prolonged excretion of ofloxacin did not result in higher urine bactericidal titers, compared to ciprofloxacin.

Administration, Oral↗
PubMed1987

Changes of N-6 and N-3 fatty acids in liver from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with alpha-linolenic or eicosapentaenoic acids.

In spontaneously hypertensive (SHR) and normotensive rats (WKY), diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA-C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA-C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. A diet with commercially available pellets served as control. After the LNA-rich diet the augmentation of LNA was most pronounced in liver triglycerides (TG) and free fatty acids (FFA), whereas the increase of EPA was most marked in phosphatidylethanolamine (PE) and phosphatidylcholine (PC) when compared with the controls. Docosahexaenoic acid (DHA) was decreased mainly in neutral lipids. Of the n-6 fatty acids linoleic acid (LA) appeared significantly depressed in TG and FFA, but increased in phospholipids. Arachidonic acid (AA), however, was lower in all lipids. In SHR and WKY fed the EPA-rich diet EPA and DHA were significantly higher as compared to the controls on a pellet diet. On the contrary, LNA was not detectable in all lipid classes. LA and AA were markedly depressed. Docosenoic acids were significantly increased. The p/s-ratio did not reflect the changes in the 20:5/20:4- and n-3/n-6-ratios. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids. Moreover, after an LNA-rich diet divergent alterations of LA in neutral lipids and phospholipids occurred. The results are dissimilar to those obtained in adipose tissue. Blood pressure was not influenced by the diets in either SHR or WKY.

Animals↗
PubMed1986

Different changes of n-6 and n-3 fatty acids in adipose tissue from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with linolenic or eicosapentaenoic acids.

In spontaneously hypertensive (SHR) and normotensive rats of the Wistar-Kyoto (WKY) and Wistar-Schönwalde (WSCHOE) strain, diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA--C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA--C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. After the LNA-rich diet, among the long-chain n-3 fatty acids EPA in epididymal adipose tissue remained unchanged, whereas docosapentaenoic (DPA) and docosahexaenoic acids (DHA) fell. The n-6 fatty acids linoleic (LA) and arachidonic acid (AA) both appeared decreased. After the EPA-rich diet, all n-3 fatty acids, i.e. not only EPA, DPA and DHA, but also LNA were augmented when compared with controls fed commercially available pellets. Among the n-6 fatty acids LA was extremely depressed, whereas AA appeared increased. The p/s-ratio was elevated after the LNA-rich diet, but decreased after the EPA-rich diet. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids, of LA and AA as well as on the p/s-ratio in adipose tissue of rats. Blood pressure was not influenced by either diet in either SHR or in both normotensive strains of rats.

Adipose Tissue↗
PubMed1986

Pharmacokinetics of ciprofloxacin. 1st communication: absorption, concentrations in plasma, metabolism and excretion after a single administration of [14C]ciprofloxacin in albino rats and rhesus monkeys.

The absorption, disposition, metabolism and excretion of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-[U-14C]piperazinyl)-3- quinoline carboxylic acid (ciprofloxacin, Bay o 9867; designated tradename: Ciprobay) were studied following a single intraduodenal (rat), oral and intravenous (rat, monkey) administration, respectively, in the dose range 5 to 30 mg/kg body weight. Ciprofloxacin was absorbed partially (30 to 40%) in both species. Peak plasma concentrations of radioactivity were measured approximately 1 h (rat) or 2 h (monkey) after oral dosing. Terminal half-lives ranging from 26 to 44 h were determined for the elimination of radioactivity from the plasma (observation time up to 48 h after dosing). Nearly identical concentrations of the unchanged drug and total radioactivity were found during the first 7 or 8 h for the monkey after intravenous injection and for the rat also after oral administration, respectively. After reaching maximum concentration of 0.25 microgram/ml after administration of 5 mg/kg to rats and 0.88 microgram/ml after dosing with 30 mg/kg to a rhesus monkey, the unchanged drug was eliminated from plasma corresponding to half-lives ranging from 3 h (rat) and 4.4 h (monkey). The radioactivity was rapidly and completely excreted in both species. After intravenous administration about 51% (rat) and 61% (monkey), respectively, was excreted via the kidney. After oral dosing renal excretion amounted to 6-14% (rat) and 30% (monkey), respectively. Maximum residues in the body (exclusive gastrointestinal tract) of 1% of dose occurred in both species. In urine and feces of rats predominantly the unchanged drug and a conjugate were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Changes of blood pressure in spontaneously hypertensive rats dependent on the quantity and quality of fat intake.

The effect of diets rich or deficient in polyunsaturated fatty acids (PUFA) on blood pressure of spontaneously hypertensive rats (SHR) and normotensive Wistar rats (WR) was studied. The diets contained either sunflower oil (PUR-SOL), linseed oil (PUR-LIN), cod-liver oil or hydrogenated palm-kernel oil (PUFA-deficient) amounting to 15 or 3 weight percent of fat. They were started at weaning (4 weeks of age) for 22 weeks or prenatally one week before mating of the parents. During the development of hypertension in SHR, systolic blood pressure was decreased in animals of all dietary groups fed 15% fat when compared to SHR on normal food (pellets), i.e. independent of the various diets loaded, all diets containing 15% fat led to a marked delay in the onset of high blood pressure as compared to SHR on normal pellet food. After manifestation of hypertension, obviously a more differentiated effect on blood pressure could be shown in SHR in dependence on different amounts of PUFA loaded. In normotensive Wistar rats (WR) after feeding linseed oil or sunflower oil also a significant lowering in blood pressure could be observed in comparison to controls fed pellets. But after feeding cod-liver oil there was no decrease in blood pressure of normotensive Wistar rats, whereas palm-kernel oil resulted in a blood pressure lowering effect only at the later age of normotensive Wistar rats. Moreover, in SHR after prenatal feeding of a LA-rich, but also a PUFA-deficient diet the blood pressure lowering effect was more pronounced as compared to postnatal feeding of the diets. SHR fed a 15% fat diet showed a significantly lower body weight in comparison to SHR fed a 3% fat diet. In both dietary groups SHR were significantly smaller than SHR fed pellets. In WKY fed a 3% or a 15% fat diet the same body weight could be confirmed. Food intake in SHR fed a 3% fat diet ad libitum appeared higher than in SHR fed a 15% fat diet ad libitum. However, considering the uptake of energy no differences between the groups could be seen. Therefore, in SHR fed a 15% fat diet, body weight and blood pressure were lowest when compared with the other groups of SHR indicating that body weight in SHR might be nearly connected with blood pressure level.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1984

Pharmacokinetics of ciprofloxacin after oral and intravenous administration in healthy volunteers.

The pharmacokinetics of ciprofloxacin (Bay o 9867) was examined after a single oral dose of 250 mg and a single intravenous dose of 100 mg respectively in six healthy male volunteers in an open, randomized crossover study. Although ciprofloxacin concentrations were measured in serum, plasma and urine by HPLC with fluorimetric detection and by microbiological assay, all pharmacokinetic calculations are based on the highly sensitive HPLC method only. The mean serum concentration of ciprofloxacin peaked approximately 1 h after the oral dose (0.94 mg/l). The elimination half-life was about 4 h and the renal clearance was 4.75 ml/min . kg; both were independent of the route of administration. The total clearance (9.62 ml/min . kg) was about twofold higher than the renal clearance. The volume of distribution of the central compartment was calculated to be 0.161 l/kg and the total volume at steady state was 2.0 l/kg. About 27% of the oral dose was excreted in urine, whereas the urinary recovery of the i.v. dose was 46%. The absolute bioavailability of ciprofloxacin was found to be approximately 60%. Ciprofloxacin appears to follow first-order, three compartment model kinetics.

Administration, Oral↗
PubMed1984

Changes of arachidonic acid in phosphatidylcholine different from other lipids in kidneys of spontaneously hypertensive rats after feeding a linoleic acid-rich diet.

In spontaneously hypertensive rats (SHR) fed a linoleic acid-rich (LAR) diet over 22 weeks blood pressure could not be influenced when compared with SHR on linoleic acid-deficient (LAD) food. On the other hand, normotensive Wistar rats (WR) revealed a significantly lower blood pressure after feeding a LAR diet. The percentages of LA and AA were markedly increased in triglycerides and free fatty acids (FFA) in renal cortex and medulla of LAR-fed SHR and WR in comparison to LAD-fed animals. In renal phosphatidylethanolamine (PE) LA was also increased whereas AA remained unchanged. On the contrary, in phosphatidylcholine (PC) LA was only slightly augmented (in SHR) or even lowered (in WR), AA appearing decreased in SHR but increased in WR. These different changes in PE and PC indicate that individual phospholipids show a dissimilar behavior after dietary interventions, which can be masked by the evaluation of total phospholipids and might be of pathophysiological relevance.

Animals↗
PubMed1984

Decrease of arachidonic acid in phosphatidylcholine from renal medulla of SHR after feeding a linoleic and linolenic acid-rich diet.

Linoleic acid-rich (LAR), linolenic acid-rich (LNAR) and linoleic acid-deficient (LAD) diets in spontaneously hypertensive rats (SHR) and normotensive rats (NR) resulted in various changes in n-6 and n-3 fatty acids of lipids in renal medulla. After LAR diets the percentage of linoleic (LA) and arachidonic acids (AA) was high only in triglycerides (TG) and free fatty acids (FFA). In phosphatidylethanolamine (PE) LA was increased after LAR diet, whereas AA remained unchanged. In phosphatidylcholine (PC) LA was higher, but AA appeared lower as compared to LAD fed SHR. After LNAR diet linolenic (LNA) and eicosapentaenoic acids (EPA) were increased, but AA appeared significantly lower. Consequently, the lowest percentage of AA was found after LNAR diet. Blood pressure could not be influenced by the diets.

Animals↗
PubMed1984

[Metronidazole concentration of the cerebrospinal fluid from slightly inflamed meninges].

The concentrations of metronidazole (Clont i.v.) in the cerebrospinal fluid were measured in 12 patients with viral meningitis or subsiding bacterial meningitis after a single infusion of 500 mg lasting 20 min. 1 h after infusion the CSF-concentrations were between 2,3 micrograms/ml and 7,4 micrograms/ml and 2 h after infusion between 6,5 micrograms/ml and 8,6 micrograms/ml. They attained 45,9% respectively 75,9% of the corresponding serum concentrations. Because the minimal inhibitory concentrations of the most important obligate anaerobic gram-negative bacteria are attained, it appears that metronidazole can be used for the treatment of bacterial meningitis caused by these pathogens.

Adolescent↗
PubMed1983

The pharmacokinetics of furazlocillin in healthy humans.

The pharmacokinetics of the novel acylureidopenicillin furazlocillin, 6-[D-2-(3-furfurylidenamino-2-oxo-imidazolidine-1-carboxamido)-2 -(4-hydroxyphenyl)-acetamido]-penicillanic acid and of its penicilloic acid derivative were investigated in five healthy male volunteers after intravenous administration of 2 and 4 g dosages. The volunteers were either in a lying or sitting position throughout the duration of the studies. The concentrations of the drug in plasma and urine were measured by two different methods in parallel: a microbiological assay and a newly developed high pressure liquid chromatography method. The latter method was also applicable for quantitation of the penicilloic acid derivative in these biological fluids. The drug's plasma protein binding (66%) and apparent red cell-plasma partition coefficient (0.055) were concentration independent. The pharmacokinetics of the drug were first order only at the lower dose level. The apparent half lives of three distinguishable phases were, respectively, 4(t1/21), 18 (t1/22), and 64 (t1/2z) min. The total and renal clearances of the drug were, respectively, 303 and 79 ml/min. The latter value implied tubular secretion of the drug. Graphical and digital computer analyses of the data were performed with a linear three compartment body model. Small but consistent deviations from linear kinetics caused by the nonrenal elimination route were observed after administration of the higher dose (4 g). In contrast, renal elimination showed no such dose dependency and was first order. The disposition kinetics of furazlocillin were body position independent. The penicilloic acid derivative of furazlocillin was found in plasma and urine in all the five subjects tested. The percentage of the dose excreted renally as the derivative amounted, respectively, to 5.2 and 7.0% after the lower and higher dosage of furazlocillin, with significant inter- and intrasubject variability. The renal clearance of the derivative was 41 ml/min.

Adult↗