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  • Articles  (816)
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  • Articles  (816)
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  • 1
    Electronic Resource
    Electronic Resource
    Safety and tolerance of single oral doses of trandolapril (RU 44.570), a new angiotensin converting enzyme inhibitor (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 17-23 
    Details
    ISSN: 1432-1041
    Keywords: trandolapril ; ACE-inhibition ; safety ; tolerance ; adverse effects ; healthy volunteers ; effect duration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The safety and tolerance of single oral doses of a new angiotensin converting enzyme (ACE) inhibitor, trandolapril have been examined in 90 healthy male volunteers, in a randomised, double blind, placebo-controlled study. The subjects were divided into 10 groups, each of 9 subjects and treatments (6 subjects on trandolapril and 3 on placebo per group) were allocated by unbalanced randomisation. Ten single, increasing oral doses were tested: 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 24 and 32 mg. The assessment criteria were clinical (monitoring of blood pressure, heart and respiratory rate, electrocardiogram, temperature and evaluation of behaviour and side effects) and routine laboratory tests. Blood pressure did not fall except for a slight drop in diastolic pressure during the first 4 h following the 32-mg dose. However, although an effect of the compound cannot be excluded, the reduction in blood pressure may have reflected intersubject variability. No orthostatic hypotension was observed. There was no change in the other vital signs, and in particular no increase in heart rate was observed. No serious adverse effect was encountered. The pharmacological activity of the compound was studied by assaying plasma ACE activity. Inhibition of ACE was linearly dose-dependant from 0 (placebo) to 2 mg, and above that dose, the inhibition was nearly total. ACE activity was markedly reduced within 30 min after administration of trandolapril, and maximal inhibition was observed from 2–4 h onwards, lasting for up to 24 h after dosing. For doses above 2 mg, inhibition was still 40% of the basal activity on Day 8 after dosing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561017
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  • 2
    Electronic Resource
    Electronic Resource
    Influence of renal failure, rheumatoid arthritis and old age on the pharmacokinetics of diflunisal (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 165-174 
    Details
    ISSN: 1432-1041
    Keywords: diflunisal ; pharmacokinetics ; healthy volunteers ; kidney failure ; rheumatoid arthritis ; aged subjects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The single-dose plasma kinetics of diflunisal was studied in healthy young and old subjects, in patients with rheumatoid arthritis, and in patients with renal failure. The plasma and urine kinetics of the glucuronidated metabolites of diflunisal were studied in the healthy elderly subjects and in the patients with renal failure. In addition, the multiple-dose plasma kinetics of diflunisal was assessed in healthy volunteers and in patients with rheumatoid arthritis. After a single dose of diflunisal the terminal plasma half-life, mean residence time and apparent volume of distribution were higher in elderly subjects than in young adults. No difference was observed in any pharmacokinetic parameter between age-matched healthy subjects and patients with rheumatoid arthritis. The elimination half-life of unchanged diflunisal was correlated with the creatinine clearance (r=+0.89) and its apparent total body clearance exhibited linear dependence on creatinine clearance (r=+0.78). In patients with renal failure, the terminal plasma half-life and mean residence time of diflunisal were prolonged. The renal and apparent total body clearances were lower, the mean apparent volume of distribution was higher and the mean area under the concentration-time curve extrapolated to infinity (AUC) was greater in the renal failure patients than in controls. The plasma concentration of the glucuronidated metabolites rapidly rose to levels above those of unchanged drug in renal patients, whereas they were lower than those of unchanged diflunisal in controls. The AUC (0–96 h) of diflunisal glucuronides in the patients was four-times that in controls, and the terminal elimination half-life of the glucuronides was prolonged in them. The renal excretion and clearance of diflunisal glucuronides were reduced when renal function was impaired. After multiple dosing, the pre-dose steady-state plasma-concentration increased with decreasing creatinine clearance (r=-0.79). When the plasma concentration exceeded 200 µmol·1−1, the elimination half-life was doubled, due to partial saturation of diflunisal conjugation. This finding suggests that lower doses could be used in long-term treatment. Thus, old age and arthritic disease appear to have little influence on the kinetics of diflunisal in the absence of renal functional impairment. Ordinary doses can be given for short term treatment of elderly patients with or without RA. In patients with renal failure, however, reduced doses of diflunisal are recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00609190
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  • 3
    Electronic Resource
    Electronic Resource
    Effects on cimetidine bioavailability of metoclopramide and antacids given two hours apart (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 409-410 
    Details
    ISSN: 1432-1041
    Keywords: cimetidine ; metoclopramide ; antacids ; absorption ; bioavailability ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma cimetidine levels were determined in 9 normal subjects after a single oral dose of cimetidine 400 mg under control conditions, 2 h before metoclopramide 20 mg and 2 h after a potent antacid. The bioavailability of cimetidine was not significantly affected by metoclopramide and it was marginally reduced by the antacid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558511
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  • 4
    Electronic Resource
    Electronic Resource
    Bioavailability of suckable tablets of oral N-acetylcysteine in man (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 419-421 
    Details
    ISSN: 1432-1041
    Keywords: N-Acetylcysteine ; oral administration ; bioavailability ; healthy subjects ; suckable formulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and bioavailability of suckable tablets and granules of N-acetylcysteine (NAC) have been compared after oral administration of 400 mg doses to 10 healthy volunteers. The oral bioavailability of the NAC tablets was 103%. In a multiple dosing study of the same tablets in the same subjects, a high maintenance plasma level of NAC was revealed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558514
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of food on the absorption and pharmacokinetics of prednisolone from enteric-coated tablets (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 423-426 
    Details
    ISSN: 1432-1041
    Keywords: prednisolone ; food intake ; enteric-coated tablets ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Prednisolone absorption and bioavailability of 10 mg enteric-coated (EC) and plain (uncoated) tablets were investigated after fasting and heavy meals (EC only) consumed to satiety in normal healthy volunteers. The same volunteers had also received 16 mg of prednisolone intravenously. In fasted subjects, the absolute bioavailability fraction, as normalised for intravenous doses, of prednisolone from plain tablets was 1.055 and from EC tablets was 0.996. The peak concentrations after plain and EC tablets were 309 and 249 ng/ml attained at 0.98 and 5.14 h, respectively. The means plasma elimination half-lives following the plain, EC tablets and intravenous administration in fasting conditions were 3.73, 3.89 and 3.78 h, respectively. Food interfered with both the absorption and the pharmacokinetics of prednisolone after EC tablets resulting in variability in its plasma levels. In some cases absorption of prednisolone was delayed for 12 h and remained at a measurable level for 24 h. In other cases, a normal absorption pattern was observed. This inter- and intrasubject variability of the effect of food appears to be related to its quantity, constituents and also the subjects physiological characteristics. It is concluded that enteric-coated prednisolone tablets should be administered at least 2 h between meals. However, for more predictable corticosteroid absorption (perhaps thus avoiding the therapeutic failure), plain prednisolone tablets are preferable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558515
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  • 6
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and tolerance of a new penem antibiotic, FCE 22101, in healthy volunteers after a single intravenous dose (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 633-635 
    Details
    ISSN: 1432-1041
    Keywords: FCE 22101 ; penem antibiotic ; pharmacokinetics ; single dose ; healthy volunteers ; adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The clinical tolerance and pharmacokinetics of FCE 22101 (sodium (5R, 6S)-6-[(1R)-hydroxyethyl]-2-carbamoyloxymethyl-2-penem-3-carboxylate), a new penem antibiotic, have been studied after giving a single i.v. dose of 4 mg·kg−1 to ten healthy male volunteers. The pharmacokinetics was estimated according to a two-compartment open model. The peak plasma concentration (Cmax) was 15.5 (1.08) µg·ml−1, mean (SEM). FCE 22101 was rapidly cleared from the systemic circulation [ $$t_{1/2\lambda _z } $$ =44.2 (4.2) min; CL=7.21 (0.47) ml·kg−1·min−1]. The mean apparent volume of distribution at steady-state was 246 (16.9) ml·kg−1. The mean residence time relative to the 10 min infusion was 39.4 (1.5)min. Urinary recovery of FCE 22101 showed wide inter-subject variation, ranging from 10.2 to 53.6% of the dose. No subject complained of adverse effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00637750
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  • 7
    Electronic Resource
    Electronic Resource
    The pharmacokinetics of clotiazepam after oral and sublingual administration to volunteers (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 617-619 
    Details
    ISSN: 1432-1041
    Keywords: clotiazepam ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary We have studied the single dose pharmacokinetics of 5 mg clotiazepam drops, oral tablets, and sublingual tablets in a cross-over study in 6 healthy volunteers (median age 28 years). The formulations had similar systemic availability. Compared with oral tablets the sublingual route gave a lower peak concentration and a delayed peak time, while drops gave a greater maximum concentration with a similar peak time. The use of drops is suggested for a more marked initial effect and the sublingual route for easier administration, especially in the elderly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562556
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  • 8
    Electronic Resource
    Electronic Resource
    Field trial of the efficacy of a simplified and standard metrifonate treatments ofSchistosoma haematobium (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 371-374 
    Details
    ISSN: 1432-1041
    Keywords: metrifonate ; Schistosoma haematobium ; therapeutic regimen ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a randomized double-blind study, the percentage egg reduction and cure rate after the standard schedule of metrifonate treatment ofSchistosoma haematobium (3 doses of 7.5 mg·kg−1 at two-weekly intervals; A) and an abbreviated regimen (3 doses of 5 mg·kg−1 in one day; B) were compared in five villages in Somalia. 300 patients who were excreting 20 or more eggs ofS. haematobium in 10 ml urine were recruited. The patients were classified according to their home villages and were then, randomly allocated to treatment A or B. They had similar ages, weights and egg output. Each patient received 3 doses of metrifonate and 2 doses of identical appearing placebo. Group A received metrifonate on the 1st, 4th and 5th dosing occasions and placebo on the 2nd and 3rd times. Group B received metrifonate on the 1st, 2nd and 3rd dosing times and placebo on the 4th and 5th times. Two hundred and one patients were followed up from 1 to 6 months. The remaining 99 (33%) patients either did not complete treatment or were lost during follow up. Egg reduction in the groups 1, 2, 3 and 6 months after treatment were 97, 97, 95 and 93% in Group A and 96, 96, 94 and 92% in Group B (NS). Corresponding cure rates for Group A were 52, 50, 48 and 44%, and in Group B they were 47, 48, 43 and 40% (NS). Seven patients from Group A and 9 from Group B complained of minor side-effects. Thus, under field conditions abbreviated regimen of metrifonate 5 mg·kg−1 3-times in one day could have as much efficacy and safety as the standard schedule of 3 doses of 7.5 mg·kg−1 at two-weekly intervals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558502
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  • 9
    Electronic Resource
    Electronic Resource
    Enalapril and hydrochlorothiazide in hypertensive Africans (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 229-234 
    Details
    ISSN: 1432-1041
    Keywords: enalapril ; hydrochlorothiazide ; hypertension ; side-effects ; Africans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The antihypertensive efficacy both of angiotensin converting enzyme (ACE) inhibitors and thiazide diuretics has been claimed to be influenced by plasma renin activity, which declines with age and is low in blacks. In a double-blind, placebo-controlled, double-dummy, randomized, parallel-group preliminary study, the antihypertensive efficacy and tolerability of the ACE inhibitor enalapril (20 mg day−1) and hydrochlorothiazide (50 mg day−1) were evaluated and compared for 4 weeks in 20 African patients with essential hypertension. The two groups had similar baseline clinical features and serum Na+ and K+ levels. Hydrochlorothiazide caused a significant and sustained fall in erect blood pressure with a reflex tachycardia. Enalapril exerted only a modest antihypertensive action, but significantly reduced erect heart rate. Direct comparison of hydrochlorothiazide — and enalapril — induced hypotension suggested a greater fall in subjects on the thiazide. The 95% confidence limits for the thiazide-enalapril difference in antihypertensive action at the end of the study was 39.5 to −7.5 mm Hg systolic and 22.0 to −6.6 mm Hg diastolic. The maximal blood pressure fall after hydrochlorothiazide was positively correlated with age (r=0.50;p〈0.05), whilst that of enalapril was inversely related age to (r=−0.57,p〈0.05). The results are compatible with the notion that ACE inhibitor monotherapy may be less effective than thiazide diuretic treatment in African and black patients with essential hypertension. The findings also support the concept that age and racial factors may influence the response to antihypertensive treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558152
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  • 10
    Electronic Resource
    Electronic Resource
    Felodipine reduces the absorption of theophylline in man (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 481-485 
    Details
    ISSN: 1432-1041
    Keywords: felodipine ; theophylline ; absorption ; metabolism ; pharmacokinetics ; blood pressure ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ten healthy male volunteers (mean age 26 years) received 200 mg theophylline aminopropanol orally 8-hourly for 4 days, followed by 5 mg felodipine 8-hourly for 6 days, and then the combination of oral felodipine and theophylline for a further 4 days. Plasma concentrations of theophylline and felodipine were determined, and theophylline and its metabolites in urine were also measured. Felodipine led to a reduction in the plasma AUC of theophylline of 18.3%. The metabolic and renal clearances of theophylline remained unchanged, but the total recovery of theophylline-derived products was significantly reduced during felodipine treatment. No change in felodipine pharmacokinetics was observed during simultaneous treatment with theophylline. Compared to theophylline treatment alone, the diastolic blood pressure was significantly reduced during felodipine treatment alone and in combination with theophylline. It is concluded that felodipine slightly but significantly lowered the plasma theophylline concentration by interfering with its absorption. The interaction in most instances would probably be of minor clinical consequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558073
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  • 11
    Electronic Resource
    Electronic Resource
    Tolerability and steady-state pharmacokinetics of terodiline and its main metabolites in elderly patients with urinary incontinence (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 487-493 
    Details
    ISSN: 1432-1041
    Keywords: terodiline ; elderly patients ; metabolites ; pharmacokinetics ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The elderly form an important target group for the treatment of urinary urge incontinence with drugs such as terodiline (Mictrol, Terolin). In order to evaluate its steady-state pharmacokinetics and tolerability in geriatric patients terodiline 12.5 mg b.d. was given to 28 hospitalized patients with urinary incontinence (mean age 85 years) for six weeks. The patients were monitored during the study and for 6 weeks afterwards, blood samples being taken at regular intervals. In addition to these multi-diseased and polymedicated patients, a small, homogenous group of healthy volunteers (mean age 40 years) was studied as a reference group, being given terodiline 12.5 mg b.d. for 2 weeks. Terodiline was generally well tolerated by the patients and no significant change in blood pressure or heart rate were found. One patient was withdrawn due to adverse effects. The mean terminal half-life of terodiline was 131 h and the clearance after oral administration (clearance/systemic availability) was 39 ml·min−1. The corresponding figures for the healthy volunteers were 57 h and 75 ml·min−1. The average steady-state serum concentration was 518 µg·l−1 in the geriatric patients and 238 µg·l−1 in the healthy volunteers. Steady-state was reached within 3 weeks in 20 of the 28 patients and within 5 weeks in 7 patients. In the geriatric patients the steady-state serum concentration of the main metabolite p-hydroxyterodiline, during the last three weeks on terodiline was 45 µg·l−1, 57 µg·l−1, and 45 µg·l−1, respectively, and a similar value was found in the healthy volunteers, 47 µg·l−1. The serum concentration of p-hydroxy-m-methoxyterodiline was 〈15 µg·l−1 both in the geriatric patients and in the healthy volunteers. Thus, terodiline 25 mg/day given to fragile elderly patients was well tolerated. It produced serum concentrations similar to those found after the standard dose of 37.5–50 mg given to younger, healthier patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558074
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  • 12
    Electronic Resource
    Electronic Resource
    Effects of diltiazem and isosorbide-5-mononitrate, alone and in combination, on patients with stable angina pectoris (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 561-566 
    Details
    ISSN: 1432-1041
    Keywords: angina pectoris ; diltiazem ; isosorbide-5-mononitrate ; combination therapy ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The anti-anginal effect of sustained release diltiazem, isosorbide-5-mononitrate (IS-5-MN) and their combination has been evaluated in 25 patients in 4 blinded treatment periods of 2 weeks each. The number of anginal attacks during each treatment period was reduced from a mean of 23 during placebo to 15 during diltiazem and 15 during combination therapy, but it was not significantly changed after IS-5-MN-20. A similar pattern was seen for nitroglycerin consumption and number of anginafree days. Maximal exercise capacity was also significantly improved following diltiazem and the drug combination, and it was not changed after IS-5-MN. ST segment depression was less pronounced after diltiazem and the combination compared to IS-5-MN. There was no difference in exercise capacity or ST segment change between diltiazem and the combination. The PR interval was slightly prolonged after diltiazem, but this was of no clinical importance. Adverse effects of diltiazem treatment were rare. Headache was common following IS-5-MN (13 patients) and the combination (11 patients). Thus, sustained-release diltiazem was of value in the treatment of chronic stable angina pectoris, whereas IS-5-MN was not effective, either as a single therapy or in combination with diltiazem. The reason for the inefficacy of IS-5-MN is not known, but the development of tolerance and an inadequate dose are possible explanations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00637736
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  • 13
    Electronic Resource
    Electronic Resource
    Effects of prolonged administration of the angiotensin converting enzyme inhibitor CGS 16617 in normotensive volunteers (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 587-591 
    Details
    ISSN: 1432-1041
    Keywords: angiotensin converting enzyme (ACE) inhibitor ; CGS 16617 ; blood pressure response ; healthy volunteers ; prolonged administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A new, orally active angiotensin converting enzyme (ACE) inhibitor, CGS 16617, has been evaluated in normotensive subjects during acute and prolonged administration. Single ascending doses of CGS 16617 20 to 100 mg were given to 9 normotensive volunteers at one week intervals and the changes in blood pressure, plasma ACE and renin activity were examined up to 72 h after drug intake. Also, CGS 16617 50 mg/day or placebo were given for 30 days to 8 and 6 normotensive subjects, respectively, maintained on an unrestricted salt diet. Blood pressure was measured daily in the office and ambulatory blood pressure profiles were also obtained before, during and after therapy, using the Remler M 2000 blood pressure recording system. CGS 16617 was an effective and long lasting ACE inhibitor. It did not induce a consistant change in blood pressure, but, the individual responses were very variable and several subjects experienced a clear decrease in the average of the blood pressures recorded during the daytime.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00637741
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  • 14
    Electronic Resource
    Electronic Resource
    Ambulatory blood pressure monitoring during sustained treatment with conventional and extended-release felodipine in mild-to-moderate hypertension (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 555-557 
    Details
    ISSN: 1432-1041
    Keywords: felodipine ; hypertension ; ambulatory blood pressure monitoring ; slow-release formulation ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To assess the duration of the antihypertensive effect of the dihydropiridine calcium antagonist felodipine in conventional (C-F) and slow-release (ER-F) formulations, 12 patients with essential hypertension underwent ambulatory blood pressure monitoring (ABPM) at the end of a 2-week treatment period with C-F 5 mg b.d., ER-F 10 mg once daily (o.d.) and placebo. C-F, ER-F and placebo were given in a double-blind 3×3 latin square design 4 times replicated. There was no systematic change in the ABP profile over the three study periods regardless of the treatment. In comparison to placebo, the mean 24-h systolic and diastolic blood pressures showed a significant and similar reduction after both formulations of F. Compared to placebo, C-F and ER-F induced a significant reduction in systolic blood pressure for 15 and 21 h, respectively, and of diastolic blood pressure for 16 and 21 h, respectively. Three patients complained of headache (mild in 2, moderately severe in 1), and two patients of nocturia, with either formulation of F.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562543
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  • 15
    Electronic Resource
    Electronic Resource
    Non-linear kinetics of 4-methylpyrazole in healthy human subjects (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 599-604 
    Details
    ISSN: 1432-1041
    Keywords: 4-methylpyrazole ; alcohol dehydrogenase inhibitor ; healthy volunteers ; pharmacokinetics ; saturable kinetics ; zero order elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In order to evaluate the pharmacokinetic profile of the alcohol dehydrogenase inhibitor 4-methylpyrazole 4-MP, a placebo-controlled, double-blind, single-dose, randomized, sequential, ascending-dose “Phase-I study” was performed in healthy male volunteers at dose levels of 10 (n=4), 20 (n=4), 50 (n=4) and 100 mg·kg−1 (n=3). In the 10 and 20 mg·kg−1 group, the elimination of 4-MP from the plasma followed non-linear kinetics with mean rates of concentration decline of 3.66 and 5.05 µmol·1−1·h−1, respectively. In the two highest dose groups, the elimination also appeared to be non-linear although the patterns were not followed long enough to confirm this, The mean rates of concentration decline at the higher doses were significantly increased, up to 14.9 µmol·l−1·h−1 at 100 mg·kg−1. The average renal clearance of 4-MP was low, 0.016 ml·min−1·kg−1, and only 3% of the administered dose was excreted unchanged in the urine, indicating metabolism as the major route of elimination. Because of the apparently unusual kinetics following single dose treatment, thorough multiple dose studies need to be carried out to determine a safe dosage regimen for 4-MP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562552
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  • 16
    Electronic Resource
    Electronic Resource
    Effects of low-dose atenolol on postural and postprandial changes in heart rate, blood pressure, venous plasma catecholamines, and plasma renin activity (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 121-125 
    Details
    ISSN: 1432-1041
    Keywords: atenolol ; food intake ; catecholamines ; plasma renin activity ; blood pressure ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The administration of a single dose of atenolol 50 mg 1 h before a standard 3100 kJ cold meal in fasting healthy subjects reduced the supine preprandial heart rate and systolic blood pressure, and blunted the postural and postprandial rises in mean heart rate and systolic blood pressure relative to placebo. It did not affect the preprandial supine diastolic blood pressure, nor the postural rise and postprandial drop in diastolic blood pressure. Preprandial administration of atenolol blunted the postural and postprandial rises in mean plasma renin activity, and it enhanced the rise in plasma noradrenaline during eating in the sitting position, and the postprandial concentrations of noradrenaline. The findings do not permit the conclusion that beta1-adrenergic stimulation was the predminant cause of these atenolol-responsive changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558218
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  • 17
    Electronic Resource
    Electronic Resource
    Effect of short-term omeprazole administration of serum pepsinogens in relation to fasting serum gastrin and gastric acid secretion (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 345-349 
    Details
    ISSN: 1432-1041
    Keywords: omeprazole ; pepsinogen A ; pepsinogen C ; fasting serum gastrin ; pentagastrin ; gastric-acid ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A study has been done in 10 male healthy volunteers of the effect of oral omeprazole 20 mg daily for 3 days on the serum concentrations of Pepsinogens A and C in relation to changes in fasting serum gastrin and basal and pentagastrin stimulated gastric acid output. The concentrations of Pepsinogens A and C showed concomitant and variable but significant increases, and the Pepsinogen A, C ratio did not change during the 3-day course of omeprazole. The increments were also significantly correlated with the increase in fasting serum gastrin and with the reduction in pentagastrin stimulated acid output. The correlations were mainly due to the marked inhibition of gastric acid secretion and the corresponding increases in serum gastrin and Pepsinogens A and C in two subjects, as in the other 8 subjects the changes were only modest. There appears to be a relationship, therefore, between the degree of inhibition of acid by omeprazole and the parallel increases in both serum pepsinogens and fasting gastrin.
    Type of Medium: Electronic Resource
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    Effect of urinary pH on the plasma and urinary kinetics of remoxipride in man (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 359-363 
    Details
    ISSN: 1432-1041
    Keywords: neuroleptics ; remoxipride ; pharmacokinetics ; urinary pH ; healthy volunteers ; overdose ; plasma prolactin ; adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of urinary pH on the plasma and urinary kinetics of remoxipride in man has been studied in an open crossover trial in ten healthy male volunteers. Ammonium chloride (urinary pH 5.2) and sodium hydrogen carbonate (urinary pH 7.8) were used as pretreatments on two occasions in randomized order. On each occasion remoxipride 50 mg solution was administered orally and plasma and urinary concentrations of the drug were determined by HPLC and plasma prolactin concentrations by RIA. Remoxipride was rapidly distributed in the body according to a one-compartment model. The mean plasma elimination half-life (t1/2) was 3.6 h in the ammonium chloride experiment and 6.2 h in the sodium hydrogen carbonate experiment. The mean plasma clearance of remoxipride was 141 and 89.9 ml·min−1 in the acidic and alkaline conditions, respectively, and the corresponding mean renal clearances were 58.5 ml·min−1 and 11.7 ml·min−1. The urinary excretion of remoxipride up to 72 h after drug administration was 43.1% and 12.3% following acidification and alkalinization, respectively. Remoxipride induced a similar rapid, transient elevation of plasma prolactin under both conditions. Thus, the urinary pH has a marked effect on the elimination kinetics of remoxipride. After an overdose, treatment with ammonium chloride might be valuable in hastening elimination of remoxipride from the body.
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    URL: http://dx.doi.org/10.1007/BF00558500
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  • 19
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    Urinary excretion of 6β-hydroxycortisol and the time course measurement of enzyme induction in man (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 39-46 
    Details
    ISSN: 1432-1041
    Keywords: 6-beta-hydroxycortisol ; enzyme induction ; cytochrome P 450 ; urinary excretion ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of enzyme induction by antipyrine, phenobarbitone and rifampicin on the time-course of urinary 6β-hydroxycortisol (6β-OHC) excretion was investigated in healthy volunteers. The drugs were given chronically for either seven or 14 days. Significant increases in 6β-OHC excretion were observed after 4 days administration of antipyrine (1.2 g), 13 days administration of phenobarbitone (100 mg), and only 2 days administration of rifampicin (0.6 or 1.2 g). During 14 days rifampicin administration (1.2 g) 6β-OHC excretion, for individual subjects, reached a maximum on Days 11–14 when excretion was significantly greater than on day 7. On stopping rifampicin, in a 7-day study, excretion decreased over the next six days, but still remained significantly elevated compared to the original control values. These studies show that measurement of urinary 6β-hydroxycortisol provides a simple non-invasive method with which to monitor the time-course of enzyme induction by drugs in man. However, the method cannot be used to predict clinically important drug interactions until the cytochrome P-450 enzyme responsible for cortisol 6β-hydroxylation has been fully characterized.
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  • 20
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    The effects of alcohol on psychological funtions in normal volunteers after 8 days' treatment with pipequaline (PK 8165), diazepam or placebo (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 47-52 
    Details
    ISSN: 1432-1041
    Keywords: pipequaline (PK 8165) ; diazepam ; alcohol ; psychomotor performance ; adverse effects ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of daily administration for 8 days of 50 mg pipequaline, 10 mg diazepam and placebo were assessed in a double-blind cross-over study with 12 healthy volunteers. This study also tested for an interaction between the drugs and alcohol on the eighth day. Subjective ratings, psychomotor and memory performance were evaluated. Diazepam produced the typical pattern of changes, namely impairments in psychomotor performance and reductions in the retention of newly memorised information. In contrast, the effects of pipequaline were relatively minor. In general, neither drug potentiated the effects of alcohol on performance, only isolated instances of non-additive interactions occurring. Subjective reports revealed that whereas both active drugs increased feelings of calmness, this result was accomplished by pipequaline with considerably less drowsiness, no euphoria and a general absence of the adverse side effects of diazepam.
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    URL: http://dx.doi.org/10.1007/BF00561022
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  • 21
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    Effect of diltiazem on the pharmacokinetics of propranolol, metoprolol and atenolol (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 67-70 
    Details
    ISSN: 1432-1041
    Keywords: diltiazem ; propranolol ; metoprolol ; atenolol ; pharmacokinetics ; drug interaction ; beta-adrenoceptor blockade ; healthy volunteers ; pharmacodynamic effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetic interaction between diltiazem and three β-adrenoceptor blockers propranolol, metoprolol and atenolol was investigated in healthy volunteers given diltiazem 30 mg or placebo t.d.s. for 3 days, followed by a single dose of propranolol 20 mg, metoprolol 40 mg or atenolol 50 mg. The AUCs of propranolol and metoprolol were significantly increased after diltiazem and it significantly prolonged the elimination half-life of metoprolol. In contrast, it did not significantly affect the pharmacokinetics of atenolol. Propranolol significantly decreased the resting pulse rate after diltiazem pretreatment as compared to placebo. The results indicate that diltiazem impaired the clearance of propranolol and metoprolol, which are principally metabolized by an oxidative pathway, and that the kinetic interaction between diltiazem and propranolol may partly be related to the significant reduction in the pulse rate produced by the latter.
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    URL: http://dx.doi.org/10.1007/BF00561026
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  • 22
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    Cardiovascular regulation and lipoprotein profile during administration of co-dergocrine in essential hypertension (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 119-125 
    Details
    ISSN: 1432-1041
    Keywords: co-dergocrine ; hypertension ; presynaptic dopamine2-receptors ; norepinephrine ; haemodynamic effects ; side-effects ; renin-angiotensin-aldosterone system ; lipoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Co-dergocrine has recently been demonstrated acutely to lower plasma norepinephrine (NE) and blood pressure (BP) in patients with essential hypertension, and similar results have been obtained during chronic administration of co-dergocrine to healthy men. The present study investigated the effect of 3 weeks of treatment with co-dergocrine 4 mg/day on BP, plasma catecholamines, certain other BP-regulating factors and serum lipoproteins in patients with essential hypertension. Compared to placebo conditions, co-dergocrine decreased supine BP and heart rate by −7% and the upright plasma NE level by −24%. Supine plasma NE also fell (−24%). Total cholesterol and the LDL + VLDL-cholesterol lipoprotein fraction were lowered by −6%. No significant change was observed in plasma renin activity, angiotensin II, aldosterone and epinephrine levels, whole blood and plasma volume, exchangeable sodium, and the cardiovascular responsiveness to NE, angiotensin II and isoproterenol. The findings suggest that in patients with essential hypertension, chronic treatment with co-dergocrine may slightly decrease sympathetic outflow and, at least in the short-term, lower the potentially atherogenic serum LDL + VLDL − cholesterol fraction.
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    URL: http://dx.doi.org/10.1007/BF00609182
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  • 23
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    Plasma atrial natriuretic peptide and the renin-aldosterone system during long-term administration of the diuretic xipamide in man (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 111-117 
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    ISSN: 1432-1041
    Keywords: alpha-atrial natriuretic peptide ; xipamide ; plasma renin activity ; plasma aldosterone ; urinary kallikrein excretion ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary We have studied the effect of xipamide on plasma α-atrial natriuretic peptide and the reninaldosterone-kallikrein system in twelve healthy men, using a double-blind cross-over design. After a run-in period on placebo for 1 week the subjects were treated with either placebo (n=6) or xipamide 20 mg once daily (n=6) for 16 weeks and were then switched to the alternative medication for another 16 weeks. The plasma concentration of α-atrial natriuretic peptide fell after 1 week of xipamide administration and increased during prolonged xipamide administration but remained suppressed. The changes in plasma α-ANP observed after 1 week of xipamide were negatively correlated with the changes in haematocrit and haemoglobin. Plasma renin activity (PRA), aldosterone concentration (PAC), and urinary excretion of aldosterone and kallikrein increased after 1 week of xipamide administration, levelled off during the second and fourth weeks, but remained elevated during further prolonged xipamide administration for 16 weeks. The xipamide-induced changes in PRA and PAC were positively correlated with the changes in the haematocrit and haemoglobin. Our data suggest that the changes in plasma renin, aldosterone, and α-atrial natriuretic peptide during xipamide administration may be related to diuretic-induced volume contraction.
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    Effect of N-acetylcysteine on plasma cysteine and glutathione following paracetamol administration (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 127-131 
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    ISSN: 1432-1041
    Keywords: N-acetyl-L-cysteine ; paracetamol ; plasma glutathione ; circulating cysteine ; healthy volunteers ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of oral N-acetyl-L-cysteine (NAC) on plasma sulphhydryls has been studied in healthy volunteers. Following NAC 30 mg·kg−1, total NAC in plasma (i.e. free NAC and NAC as disulphides) reached a median peak concentration of 67 nmol·ml−1 within 45 to 60 min, and disappeared with an apparent half-life of 1.3 h. Only a fraction of total NAC (AUC 163 nmol·ml−1·h) was in the form of free NAC (AUC 12 nmol·ml−1·h, peak concentration 9 nmol·ml−1). Free cysteine was markedly increased (peak increment 49 nmol·ml−1; AUC 80 nmol·ml−1·h). Total cysteine and free and total glutathione in plasma were unchanged. Following the administration of 2 g paracetamol plasma cysteine and glutathione decreased (median decrement in AUC over 3 h was 5.1 nmol·ml−1·h and 3.8 nmol·ml−1·h, respectively). In contrast, the administration of 2 g NAC together with paracetamol resulted in an increase in the AUC of cysteine (+29.2 nmol·ml−1·h) and glutathione (+4.6 nmol·ml−1·h). The data show that NAC leads to a marked increase in circulating cysteine, in part by reacting with cystine and thereby forming mixed disulphides with cysteine and releasing free cysteine as shown in vitro. NAC had no effect on plasma glutathione in the absence of increased stress on the glutathione pools. However, NAC supports glutathione synthesis when the demand for glutathione is increased, as during the metabolism of paracetamol.
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    Use of dimethicone to reduce the fall in gastric potential difference induced by bile salts (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 379-381 
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    ISSN: 1432-1041
    Keywords: dimethicone ; cytoprotection ; gastric lesions ; potential difference ; bile salts ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The gastric potential difference (PD) was measured in ten healthy volunteers after sodium taurocholate intake. This bile salt was given after treatment with dimethicone or placebo in a cross-over design study. With dimethicone the fall in PD was lower (16.1 vs. 24.8 mV,) and shorter (32.5 vs. 51.0 min) than with the placebo. Our result suggests that the silicone can prevent the formation of the gastric lesions induced by bile salts.
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    Pharmacokinetic properties and clinical efficacy of once-daily sustained-release naproxen (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 383-388 
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    ISSN: 1432-1041
    Keywords: naproxen ; sustained-release formulation ; pharmacokinetics ; bioavailability ; efficacy ; tolerability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and clinical efficacy of a once-daily sustained-release formulation of naproxen (sodium salt) have been compared with those of conventional-release agents. In a single dose pharmacokinetic study, the rate of absorption of the sustained-release preparation was less than that of a conventional-release preparation but the extent of absorption was the same. As is the case with conventional-release naproxen, food decreased the rate but not the extent of absorption of the sustained-release formulation. On multiple dose administration for 7 days, the AUC and average concentrations of the sustained release preparation (1 g daily) were the same as those for conventional release preparations of naproxen sodium (250 mg four times daily) and naproxen free acid (500 mg daily). The conventional-release sodium salt was absorbed more quickly with no differences in bioavailability. A double-blind clinical comparison in patients with osteoarthritis showed the sustained-release preparation (1 g daily) to be equivalent in efficacy to conventional naproxen capsules (500 mg twice daily) but to have a significantly lower incidence of gastrointestinal side-effects. The results suggest that sustained-release naproxen sodium has potential for use as a once-daily treatment for inflammatory disease.
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    Comparison of the gastroduodenal tolerance of tenoxicam and diclofenac Na (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 419-421 
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    ISSN: 1432-1041
    Keywords: Tenoxicam ; Diclofenac Na ; NSAID ; gastroduodenal damage ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The gastroduodenal tolerance of Tenoxicam and Diclofenac Na has been evaluated in a double-blind, parallel group study in 36 healthy male volunteers. The doses used were 20 mg Tenoxicam and 100 mg Diclofenac Na daily in a retard formulation for 14 days. Gastric tolerance was assessed by endoscopy, which was performed at base-line, after the 14 day dosing period and after a 14 day follow-up period without treatment. The mucosal lesions were scored using modified Lanza criteria. Tenoxicam was significantly better tolerated at the end of the 14 day dosing period (mean gastric score: Tenoxicam 1.3; Diclofenac Na 2.2). The two treatment groups had comparable scores at the base-line and post study assessments. Tenoxicam and Diclofenac Na were generally well tolerated. Only two volunteers reported intermittant lack of appetite, heartburn and a feeling of pressure in the stomach.
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    Comparative effects of simvastatin and cholestyramine in treatment of patients with hypercholesterolaemia (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 455-460 
    Details
    ISSN: 1432-1041
    Keywords: simvastatin, cholestyramine ; hypercholesterolaemia ; HMG CoA reductase inhibitor ; lipoproteins ; alipoproteins ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The efficacy and safety of 20 mg simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) and of 16 g cholestyramine daily in the treatment of 34 hypercholesterolaemic patients have been compared after dietary treatment and stratified randomization. The effect of combined treatment with the two drugs was studied in 5 patients with severe hypercholesterolaemia. After 6 weeks of treatment the simvastatin group showed a significantly greater (p〈0.05) decrease in the mean total plasma cholesterol concentration from 7.88 to 5.48 mmol/l than in the cholestyramine group in whom there was a fall from 7.82 to 6.73 mmol/l. Simvastatin decreased the mean plasma LDL cholesterol concentration from 6.07 to 3.76 mml/l and cholestyramine decreased it from 6.16 to 4.46 mmol/l. Simvastatin also reduced the mean plasma total triglycerides by 24%, VLDL triglycerides by 20% and VLDL cholesterol by 36%, while cholestyramine led to increases in these parameters by 64%, 85% and 63%, respectively. Mean plasma HDL cholesterol concentration and the subfractions HDL2 and HDL3 cholesterol were significantly increased by simvastatin. Simvastatin and cholestyramine reduced the mean plasma apolipoprotein B concentration by 28% and 13%, respectively. The mean plasma apolipoprotein A–I concentration was significantly higher only on simvastatin treatment. Simvastatin did not cause any subjective or objective side effects, while cholestyramine caused gastrointestinal problems in 31% of patients. Small increases in serum alanine aminotransferase (S-ALT) activity were seen with both drugs. Cholestyramine significantly raised the serum alkaline phosphatase (S-ALP) although to a level still within the normal range. It is concluded that 20 mg simvastatin was more effective than 16 g cholestyramine in the treatment of hypercholesterolaemia. Simvastatin was also better tolerated and it is more convenient for patients to take.
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    Effect of zolpidem on sleep in insomniac patients (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 461-466 
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    ISSN: 1432-1041
    Keywords: zolpidem ; insomnia ; sleep ; hypnotic ; imidazopyridine ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of zolpidem 10 mg p.o. on sleep in patients with persistent psychophysiological insomnia was assessed by polysomnographic recordings. An improvement in sleep with no rebound insomnia was observed during treatment for two weeks. Time awake after the onset of sleep was reduced after one week and increased after two weeks, whereas sleep latency remained reduced. Zolpidem markedly increased the duration of Stage 2 sleep without affecting either slow wave sleep or REM sleep. Subjective evaluation of improvement in sleep was well correlated with sleep laboratory findings. Zolpidem did not impair the immediate memory or psychomotor performance of patients on the morning after its administration. Side-effects during the period of drug administration included drowsiness, fatigue, headache, anxiety and irritability. They were mild or moderate and wore off soon after awakening.
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    Pharmacokinetic characterization of the antiarrhythmic drug diprafenone in man (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 313-316 
    Details
    ISSN: 1432-1041
    Keywords: diprafenone ; pharmacokinetics ; bioavailability ; first-pass metabolism ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of the antiarrhythmic drug diprafenone have been investigated in 6 healthy volunteers following single intravenous (50 mg) and oral doses (50 and 150 mg). Diprafenone was mainly eliminated by metabolism in the liver. Following i.v. infusion of 50 mg diprafenone, the terminal half-life of elimination was 1.50 h, the volume of distribution at steady-state was 1.23 l·kg−1, and the free fraction in plasma was 1.68%. Mean total plasma clearance was 741 ml·min−1·70 kg−1, which approaches normal liver blood flow after correction for the blood/plasma concentration ratio. Thus, diprafenone can be classified as a high extraction drug. Following oral administration, a dose-dependent increase in bioavailability from 10.9 (50 mg dose) to 32.5% (150 mg dose) was observed. The data suggest that diprafenone is subject to saturable hepatic first-pass metabolism.
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    Suppression of histamine-induced skin reactions by loratadine and cetirizine diHCl (1989)
    Springer
    European journal of clinical pharmacology 36 (1989), S. 617-619 
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    ISSN: 1432-1041
    Keywords: cetirizine ; loratadine ; histamine skin reactivity ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The skin reactivity to histamine was measured in 10 healthy and 10 atopic subjects after the ingestion of single doses of loratadine 10 mg, cetirizine diHCl 10 mg and placebo, in a double-blind cross-over randomized study. The anti-H1 effect of cetirizine diHCl proved to be significantly more rapid, more pronounced and longer lasting than that of loratadine.
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    Reduction of postprandial blood glucose by theα-glucosidase inhibitor Miglitol (BAY m 1099) in Type II diabetes (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 33-36 
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    ISSN: 1432-1041
    Keywords: diabetes mellitus ; Miglitol ; Type II diabetes ; alpha-glucosidase inhibitor ; blood glucose ; glucose absorption ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The dose-dependency of the effects of the α-glucosidase inhibitor Miglitol (BAY m 1099) was investigated in 8 Type II diabetic patients. Administration of increasing doses of Miglitol once daily in the morning on four consecutive days concomitantly with a standardized meal containing 50 g starch led to a dose-dependent reduction in the maximal increase in the postprandial blood glucose level and in postprandial incremental AUC of blood glucose. The latter was significant for 50, 100, 75 and 200 mg Miglitol. Bay m 1099 also markedly retarded the appearance of the peak postprandial blood glucose concentration, which indicates delayed carbohydrate absorption. Serum insulin levels, documented as incremental AUCs of the serum insulin excursions, were not reduced dose dependently, because of the impaired insulin secretory capacity of the patients.
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    Nifedipine and alpha-adrenoceptor function in human finger skin vessels (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 107-110 
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    ISSN: 1432-1041
    Keywords: nifedipine ; skin vessel contraction ; alpha-adrenoceptor activation ; cooling ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Experiments were designed to study the effect of the calcium entry blocker nifedipine on contractions evoked by alpha-adrenoceptor activation in human finger skin vessels and to show whether nifedipine could prevent the vasoconstriction induced by local cooling. Vasoconstriction of finger skin vessels was evoked with phenylephrine (a preferential alpha1-adrenoceptor agonist), BHT 933 (a preferential alpha2-adrenoceptor agonist) and by local cooling. The alpha-adrenoceptor agonists were administered into the skin by iontophoresis and local cooling was produced with a Peltier element. Nifedipine significantly attenuated the vasoconstrictor responses both to alpha1- and alpha2-adrenoceptor stimulation, the effect on alpha2-mediated responses being more pronounced. It had no effect on the vasoconstriction induced by local cooling of finger skin.
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    Effect of one month of lactitol treatment on calcium metabolism in man (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 205-207 
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    ISSN: 1432-1041
    Keywords: lactitol ; calcium homeostasis ; osteocalcin ; parathormone ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The chronic use of lactitol as a food additive or laxative might adversely affect calcium homeostasis. Its effect on calcium metabolism has been examined in an open cross-over study in 12 volunteers given 20–40 g lactitol per day for one month. Compared to a control period without lactitol, the disaccharide did not alter the urinary excretion of calcium, inorganic phosphate or hydroxyproline, nor did it alter the circulating levels of calcium, phosphate, alkaline phosphatase, parathormone and osteocalcin. Chronic treatment with lactitol in laxative doses had no measurable effect on calcium metabolism in man.
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    Application of a radioreceptor assay in a pharmacokinetic study of oxitropium bromide in healthy volunteers after single i.v., oral and inhalation doses (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 507-512 
    Details
    ISSN: 1432-1041
    Keywords: oxitropium bromide ; pharmacokinetics ; radioreceptor assay ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Oxitropium bromide (OXBR) is a new anticholinergic drug, which is expected to be useful in the treatment of nocturnal asthma. The only pharmacokinetic data were obtained with the14C-labelled compound. A sensitive radioreceptor assay for the determination of unlabelled OXBR in plasma was developed, based on competition between OXBR and3H-N-methylscopolamine for binding to muscarinic receptors. OXBR was isolated from plasma by ion-pair extraction and re-extraction. Active metabolites present in significant amounts might interfere in the assay, but this was not the case for OXBR metabolites. Detection limits were 300 pg·ml−1 and 3 ng·ml−1 for plasma and urine, respectively. For the latter no extraction step was required. The single dose pharmacokinetics of OXBR was studied following inhalation (3 mg), oral (2 mg) and i.v. (1 mg) administration to 12 men, following an open, cross-over design. After i.v. administration the kinetic parameters were: Vc 38.4 l; t1/2α 5.3 min; t1/2β 142 min; AUC 8.9 h·ng·ml−1; renal excretion 50.2%, k10 3.5 l·h−1 and total clearance 1874 ml/min. The apparent bioavailabilities were 0.48% and 12.4% by the oral and inhalation routes, respectively, based on the cumulative renal excretion. There were moderate adverse reactions due to the anticholinergic properties of the drug.
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    Effects of rhein on renal arachidonic acid metabolism and renal function in patients with congestive heart failure (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 1-5 
    Details
    ISSN: 1432-1041
    Keywords: congestive heart failure ; rhein ; non-steroidal antiinflammatory drugs (NSAIDs) ; renal prostaglandins ; renal function ; serum thromboxane ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a randomized double-blind cross-over study the effects of rhein (administered as diacetylrhein 50 mg b.d. for 5 days) and placebo on renal arachidonic acid metabolism and renal function have been compared in 12 elderly patients (mean age 75.2 years) with congestive heart failure, whose renal function was known to be dependent on the integrity of the renal prostaglandin system. Rhein like placebo, did not induce any change in the urinary excretion of prostaglandin (PG) E2, 6-keto-PGF1α and thromboxane (TX) B2, nor did it affect creatinine clearance, blood urea, urine output, natriuresis, body weight, plasma renin activity or plasma aldosterone concentration. Separate analysis of the results obtained in the 5 patients receiving diuretic treatment did not show any significant effect of rhein as compared with placebo on the parameters investigated. Serum TXB2 concentration during whole blood clotting, as an index of platelet arachidonic acid metabolism, also showed no significant difference when DAR and placebo were compared. It is concluded that in patients with congestive heart failure rhein does not inhibit renal or platelet eicosanoid metabolism, nor does it modify renal function, sodium excretion or the renal response to diuretics.
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    Haemodynamic and pharmacokinetic evaluation of alfuzosin in man. A dose ranging study and comparison with prazosin (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 53-58 
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    ISSN: 1432-1041
    Keywords: alfuzosin ; prazosin ; alpha1-adrenoceptor antagonist ; noradrenaline ; pharmacokinetics ; pharmacodynamics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In an open dose ranging study with random inclusion of placebo, alfuzosin (α1-adrenoceptor antagonist) 1, 2.5 and 5 mg was administered to 6 healthy volunteers, 3 of the volunteers received 10 mg alfuzosin. Supine systolic blood (SBP) pressure was not reduced by alfuzosin although significant increases occurred in supine heart rate (HR) after 2.5 and 5 mg. In the standing position, SBP was reduced at 2 and 4 h with 5 mg alfuzosin; significant increases in HR occurred following 1, 2.5 and 5 mg at 2, 4, 6 and 8 h after administration. Exercise SBP was not reduced; diastolic blood pressure was significantly reduced at 4 and 6 h with 5 mg alfuzosin. More marked effects were seen in the 3 subjects who received 10 mg alfuzosin. After 1 and 5 mg, tmax ranged from 1–2 h; Cmax (4.1 to 20.8 ng · ml−1; AUC (0–24) 20 to 132 ng · ml−1 · h (1 and 5 mg respectively) increased progressively with dose indicating dose dependent kinetics; no significant changes occurred in the visual analogue scale for sedation. A comparison of alfuzosin 5 mg, prazosin 1 mg and placebo each administered for 4 days, indicated that alfuzosin did not significantly reduce standing SBP on either Day 1 or Day 4; prazosin reduced SBP at 2 and 4 h on Day 1 and 6 h on Day 4 compared to placebo. Standing HR was increased by alfuzosin at 2 h on Day 1 and Day 4; increases occurred with prazosin at 2, 4, 6 and 8 h on Day 1 and 6 h on Day 4. Supine plasma noradrenaline increased with alfuzosin and prazosin at 2 and 4 h on Days 1 and 4; the increases were not significantly different. The plasma elimination half-life (t1/2) for alfuzosin was 3.4 h and 3.1 h after acute and chronic administration; (t1/2) for prazosin was 2.6 and 2.9 h. In conclusion alfuzosin causes small reductions in systolic blood pressure, accompanied by a dose dependent increase in heart rate in the supine and standing position and following exercise.
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    Metabolism and disposition of intravenously administered acetyl-L-carnitine in healthy volunteers (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 59-63 
    Details
    ISSN: 1432-1041
    Keywords: acetyl-L-carnitine ; renal clearance ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of acetyl-L-carnitine hydrochloride were investigated in 6 healthy volunteers of both sexes after i.v. injection of 500 mg of the drug, expressed as inner salt. Plasma concentrations and urinary excretion of acetyl-L-carnitine (A), L-carnitine (B) and total acid soluble L-carnitine fraction were evaluated over a period lasting from 24 h before to 48 h after the administration. Plasma concentrations of A increased quickly after administration and then declined reaching base values within 12 h. Conversely, plasma concentrations of B rose more slowly, reaching a peak in 30–60 min, and then declined to base values within 24 h. Most of the injected dose of acetyl-L-carnitine was recovered in the urine during the first 24 h after administration as B and A. Mean renal clearance of both A and B during the first 12 h after injection was higher than the base values, suggesting the presence of a saturable tubular reabsorption process which may counterbalance major changes occurring in plasma concentrations of L-carnitine pattern.
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    Zero-order absorption and linear disposition of oral colchicine in healthy volunteers (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 79-84 
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    ISSN: 1432-1041
    Keywords: colchicine ; pharmacokinetics ; oral administration ; zero-order absorption ; systemic availability ; dose dependency ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of colchicine has been studied in nine healthy male volunteers after oral doses of 0.5, 1, and 1.5 mg as tablets. Plasma and urine samples were collected over 48 h and analysed for colchicine by radioimmunoassay. Individual colchicine concentration profiles in plasma and urine were well described by a two-compartment open model with zero-order input. Considering the absorption variables as specific to each experiment, the lag time (0–0.35 h) and duration (0.39–2.38 h) of absorption were found to be independent of dose, while the zero-order rate constant of absorption (k0) increased linearly with dose. Disposition variables were taken as common to the three experiments, except in six subjects in whom renal excretion varied significantly across experiments in a dose-independent manner. For seven subjects the terminal half-life was 19.4 h, the oral apparent volume of distribution at steady-state (Vss/f) was 691 l, and the oral systemic clearance (CL/f) was 33.1 l·h−1. In the two other subjects, the values were unreliable, but the estimated terminal half-life was greater than 48 h, Vss/f ranged from 1690 to 3480 l, and CL/f was in the range of the other subjects in 1 subject, and it was about 15l·h−1 in the other. In the latter subject, these estimates, together with the observation that plasma concentration reached a plateau at 2 to 5 h after ingestion, suggest enterohepatic cycling of colchicine. Overall, the disposition of colchicine was linear in the dose range 0.5–1.5 mg, with a long terminal half-life, and absorption obeyed zero-order kinetics, with k0 proportional to dose.
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    Influence of hyperlipidic food on the kinetics of slow-release formulations of theophylline (1989)
    Springer
    European journal of clinical pharmacology 37 (1989), S. 85-90 
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    ISSN: 1432-1041
    Keywords: theophylline ; sustained-release formulation ; bioavailability ; fatty food ; dumping effect ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A cross-over study of kinetics has been undertaken in 12 healthy adults volunteers using two sustained-release theophylline products that allow once a day dosing (Theo-Dur tablets and Dilatrane A.P. bead filled capsules) to compare the i.v. pharmacokinetic profiles when taken with an hyperlipidic meal and a balanced standard meal. Each subject took part in four phases in randomised order, corresponding to all possible combinations of the products and the types of meal. Each phase involved a single dose of 9 to 11 mg·kg−1 theophylline administered at 20.00 h, at the beginning of the meal, with 100 ml water. The two formulations were found to be bioequivalent with both types of meal. Taken with a balanced meal, the mean parameters were similar; for Theo-Dur and Dilatrane A.P. they were respectively: Cmax: 11.32 mg·l−1 which plateaued from 8 to 10 h after dosing and 10.9 mg·l−1, which plateaued after 6 to 10 h; AUC 230 mg·h·l−1 and 220 mg·h·l−1; and MRT 18.2 h and 17.7 h. After the hyperlipidic meal the values for Theo-Dur and Dilatrane A.P. respectively, were: Cmax 10.9 mg·l−1 at 12 h and 11.3 mg·l−1 at 10 h; AUC 237 mg·h·l−1 and 227 mg·h·l−1; and MRT 19.2 h and 18.9 h. In spite of a decrease in the absorption rate, which led to a shift to the right of about 2 h of the plasma concentration-time curve, the bioavailability of both formulations were not significantly modified by a hyperlipidic meal as compared to a balanced meal. The shift of the curve with fatty food was not clinically important, as there was no dumping effect. The main difference between the two formulations was seen during the absorption phase, which was linear and less variable with Dilatrane A.P. and sigmoidal with Theo-Dur. This was observed with both types of meal.
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    Calcium movements during each heart beat (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 103-108 
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    ISSN: 1573-4919
    Keywords: heart ; relaxation ; calcium ; sodium-calcium exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Transsarcolemmal calcium movements are closely related to force generation in the heart. It is important to understand the transport pathways that control these movements of calcium across the sarcolemmal membrane. In the normal, beating heart, sodium-calcium exchange appears to be an important mechanism for the extrusion of calcium from the cell. The kinetics of this exchange are dependent upon the characteristics of the cell action potential. Calcium efflux via sodium-calcium exchange may be sufficient to balance calcium entry through calcium channels during the action potential.
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    Sodium-calcium exchange in mammalian heart: current-voltage relation and intracellular calcium concentration (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 97-102 
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    ISSN: 1573-4919
    Keywords: calcium ; sodium ; fura-2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Membrane currents and changes in intracellular calcium ion concentration ([Ca2+]i) have been recorded that can be attributed to the operation of an electrogenic, voltage-dependent sodium-calcium (Na-Ca) exchanger in mammalian heart cells. Single guinea-pig ventricular myocytes under voltage clamp were perfused internally with the fluorescent Ca2+-indicator, fura-2, and changes in [Ca2+]i and membrane current that resulted from Na-Ca exchange were isolated through the use of various organic channel blockers (verapamil, TTX), impermeant ions (Cs+, Ni2+), and inhibitors of sarcoplasmic reticulum (ryanodine). The I-V relation of Na-Ca exchange was obtained from the Ni2+-sensitive current elicited by ramp repolarization from +90 mV to −80 mV. Ramps were sufficiently rapid that little change in [Ca2+]i occured during the ramp. The (constant) [Ca2+]i during the ramp was varied over the range 100 nM to 1000 nM by varying the amplitude and duration of a pre-pulse to the ramp. The reversal potential of the Ni2+-sensitive ramp current varied linearly with 1n([Ca2+])i. The I-V relations at different [Ca2+]i over the range −60 mV to +140 mV were in reasonable accord with the predictions of a simple, simultaneous scheme of Na-Ca exchange, on the basis that only [Ca2+]i had changed. The relationship between [Ca2+]i and current at a constant membrane voltage was also in accord with this scheme. We suggest that Ca2+-fluxes through the exchanger during the cardiac action potential can be understood quantitatively by considering the binding of Ca2+ to the exchanger during the [Ca2+]i-transient and the effects of membrane voltage on the exchanger.
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    Appraisal of the physiological relevance of two hypotheses for the mechanism of calcium release from the mammalian cardiac sarcoplasmic reticulum: calcium-induced release versus charge-coupled release (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 135-140 
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    ISSN: 1573-4919
    Keywords: calcium ; heart ; sarcoplasmic reticulum ; excitation-contraction coupling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Recent studies correlating the calcium current with, respectively, the clamp-imposed voltage and the calcium current in intact isolated mammalian cardiac myocytes are reviewed. The major findings are the following: [1] With the exception of one group, all investigators agree that a calcium transient is never observed in the absence of a calcium current. In addition, there is a good correlation between voltage dependence of the calcium current and that of the calcium transient, although this correlation may vary among the cardiac tissues from different animal species. [2] Repolarization clamp pulses from highly positive potentials produce a ‘tail current’ which is associated with a ‘tail calcium transient’. [3] The calcium transient is inhibited when the calcium current is blocked by calcium deprivation or substitution, or by the addition of calcium current antagonists, despite the fact that sarcoplasmic reticulum still contains calcium that can be released by caffeine (with inhibition of this release by ryanodine). These three findings are strongly in favor of a calcium-induced release of calcium and against the hypothesis of charge-movement-coupled release of calcium from the sarcoplasmic reticulum. [4] The only finding that would be more in favor of the latter hypothesis (although till reconciliable with the former) is that repolarization occurring before the rapid rise of calcium transient is complete curtails the calcium transient. Thus, the possibility that charge movement might somehow regulate calcium-induced release of calcium cannot be excluded.
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    The effect of acidosis on excitation-contraction coupling in isolated ferret heart muscle (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 169-173 
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    ISSN: 1573-4919
    Keywords: pH ; calcium ; heart muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The contractile response to acidosis is the final product of a number of different changes in the excitation-contraction coupling pathway: (i) Cai increases and subsequently decreases during acidosis; (ii) the action potential becomes longer; (iii) the sensitivity of the contractile proteins to Ca2+ decreases. The increase of Cai and the lengthening of the action potential may help to maintain contractile function, although this advantage may be offset if spontaneous Ca2− release from the s.r. occurs, secondary to the increase of Cai. The recovery of force shown in figure 1 occurs at a time when the calcium transient is decreasing, and therefore represents an increasing sensitivity of the contractile proteins to Cai, probably due to a recovery of intracellular pH(6), although it is also possible that a disappearance of spontaneous Ca2+ releases from the s.r. may be contributing [2].
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    The contribution of mitochondrial calcium ion exchange to relaxation of tension in cardiac muscle (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 127-133 
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    ISSN: 1573-4919
    Keywords: mitochondria ; sarcoplasmic reticulum ; calcium ; myocytes ; caffeine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The possible contribution of mitochondrial Ca2+ accumulation and release to contractile phenomena has been investigated. Two intracellular fractions of Ca2+ sequestration can be identified in cardiac myocytes, one ascribed to mitochondria. Two modes of Ca2+ transport exist within the mitochondrial fraction, one dependent upon mitochondrial respiration and the other upon extramitochondrial [Na+]. Experiments with trabeculae show that under appropriate conditions, the rate of relaxation and the amount of tension developed is dependent on these two modes of Ca2+ transport. A model is presented quantifying the contribution of the mitochondria to relaxation.
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    The control of calcium influx by cytoplasmic calcium in mammalian heart muscle (1989)
    Springer
    Molecular and cellular biochemistry 89 (1989), S. 109-113 
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    ISSN: 1573-4919
    Keywords: heart muscle ; calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The role of Ca2+ in the initiation and maintenance of contraction has been extensively studies. Many of these studies have focused on how Ca2+ influx and efflux affect cytoplasmic Ca2+ (Cai) and, therefore, contraction in cardiac muscle. However, it has recently become apparent that Cai itself may play a major role in the control of Ca2+ influx and efflux from cardiac muscle. Here we review current ideas on the mechanisms underlying Ca2+ homeostasis in cardiac muscle, with specific attention to how Cai may control Ca2+ influx, both under normal and pathological conditions.
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    Redistribution of subcellular calcium in rat liver on administration of vanadate (1989)
    Springer
    Molecular and cellular biochemistry 90 (1989), S. 155-164 
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    ISSN: 1573-4919
    Keywords: polyvanadate ; mitochondria ; calcium ; pyruvate dehydrogenase ; receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Mitochondria isolated from the livers of rats administered with sodium meta-, ortho-, or polyvanadate, but not vanadyl sulphate, exhibited enhanced Ca2+ — stimulated respiration and uptake of calcium. These effects were shown also by mitochondria isolated from livers perfused with polyvanadate. The concentration of acid-soluble calcium decreased significantly in the mitochondrial fraction on vanadate treatment, while that in the cytosol showed a corresponding increase. Phenoxybenzamine, an antagonist to a-adrenergic receptors, effectively inhibited vanadate-induced Ca2+ mobilization, but surgical sympathectomy was without effect. This is the first demonstration of vanadate mimicking α-adrenergic agonists in vivo.
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    Attraction of adult sweet potato weevils,Cylas formicarius elegantulus (Summers), (Coleoptera: Curculionidae), to sweet potato leaf and root volatiles (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1095-1106 
    Details
    ISSN: 1573-1561
    Keywords: Sweet potato weevil ; Cylas formicarius elegantulus ; Coleoptera ; Curculionidae ; Ipomoea batatas ; sweet potato volatiles ; sesquiterpenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A dual-choice olfactometer was developed to study the responses of sweet potato weevils,Cylas formicarius elegantulus (Summers), to volatiles from the sweet potato,Ipomoea batatas (L.) Lam. Both males and females were attracted by volatiles from sweet potato leaves and a methylene chloride leaf extract. Females, but not males, responded to volatiles from storage roots and a methylene chloride root extract. Leaves and storage roots from four sweet potato cultivars (Centennial, Jewel, Resisto, and Regal) were attractive to female weevils; however, the attractant response varied with cultivar. GC profiles from leaf and root extracts, and GC-MS analysis of leaf extract, for Jewel cultivar enabled the volatile peaks to be identified as sesquiterpenes.
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    Field responses of certain forest Coleoptera to conifer monoterpenes and ethanol (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1729-1745 
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    ISSN: 1573-1561
    Keywords: Kairomones ; host attraction ; monoterpenes ; ethanol synergism ; turpentine ; trapping ; Cerambycidae ; Scolytidae ; Curculionidae ; Cleridae ; Buprestidae ; Dryocetes autographus ; Monochamus scutellatus ; Hylobius pales ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Field experiments using baited sticky stovepipe traps and Lindgren multiple funnel traps were done near Chalk River, Ontario, Canada, to determine the effects of conifer monoterpenes (α-pinene, β-pinene, myrcene, limonene, camphene and carene) and ethanol on the number of beetles captured. Several species of conifer-feeding beetles were attracted to the monoterpenes or to monoterpenes and ethanol, including species in the families Cerambycidae (Asemum striatum, Acmaeops proteus, Xylotrechus undulatus, Monochamus scutellatus), Curculionidae (Pissodes strobi, Hylobius pales), and Scolytidae (Dryocetes autographus, Ips grandicollis). Species of Buprestidae generally did not respond to the monoterpenes or to ethanol. Species of Cleridae (Thanasimus dubius, Enoclerus nigripes rufiventris, Enoclerus nigrifrons gerhardi) which are predators of conifer bark beetles were attracted to the monoterpenes. Synergism between monoterpenes and ethanol was evident forM. scutellatus, H. pales, andD. autographus. While α-pinene was the most potent attractant for most beetle species, monoterpenes other than α-pinene synergized attraction to ethanol forD. autographus. Attraction of beetles to commercial turpentine and ethanol did not differ significantly from attraction to a pure monoterpene blend and ethanol.
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    Pygidial secretions ofPasimachus subsulcatus (Coleoptera: Carabidae) deter predation byEumeces inexpectatus (Squamata: Scincidae) (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1033-1044 
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    ISSN: 1573-1561
    Keywords: Defensive mechanism ; avoidance response ; Eumeces inexpectatus ; Pasimachus subsulcatus ; Coleoptera ; Carabidae ; lizard ecology ; lizard predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The carabid beetlePasimachus subsulcatus is an abundant ground-dwelling insect in west central Florida that exudes a powerful mucous membrane irritant when disturbed. This secretion can be sprayed over 10 cm from the abdominal tip. The southeastern five-lined skink,Eumeces inexpectatus, is an abundant insectivorous lizard sympatric withPasimachus. We assessed the availability ofPasimachus toEumeces and found it to be within the foraging microenvironment of the lizard. Analysis ofEumeces gut contents and field feeding trials indicate thatPasimachus are not ingested by the lizard, yet arthropods of comparable size and exoskeletal thickness are ingested. The movement response ofEumeces to isolatedPasimachus secretion constituents, conducted in a modified Y-maze laboratory experiment, was used to assess the repellent capabilities of the secretion.Eumeces are consistently repelled byPasimachus secretion constituents, indicating that the beetle is protected chemically from the lizard.
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    Structure-activity studies on aggregation pheromone components ofPityogenes chalcographus (Coleoptera: Scolytidae) (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 685-695 
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    ISSN: 1573-1561
    Keywords: Synergism ; aggregation pheromone ; Pityogenes chalcographus ; Coleoptera ; Scolytidae ; chalcogran ; methyl (2E,4Z)-2,4-decadienoate ; enantiomers ; isomers ; stereoisomers ; synthesis ; bioassay ; structure-activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Syntheses of all four Stereoisomers (2S,5S; 2S,5R;2R,5R; and2R,5S) of chalcogran, a major component of the aggregation pheromone ofPityogenes chalcographus, and of all four isomers (2Z,4Z; 2Z,4E; 2E,4E; and 2E,4Z) of methyl 2,4-decadienoate (MD), the second major pheromone component, are briefly described. Attraction responses of walking beetles of both sexes were tested to mixtures of the synergistic pheromone components or analogs. These bioassays showed that theE,Z isomer of MD is the most active when tested with chalcogran. When tested with (E,Z)-MD, (2S,5R)-chalcogran was the most active stereoisomer, while 2R,5R and 2R,5S isomers had intermediate activities, and the 2S,5S isomer was inactive. There was no evidence that the relatively less active Stereoisomers of chalcogran inhibited or promoted attraction to (2S,5R)-chalcogran with (E,Z)-MD. Male beetles only produce the activeE,Z isomer of MD (inactive alone) and their hindguts contain the most active (2S,5R)- and least active (2S,5S)-chalcogran. A mixture of all MD isomers with racemic chalcogran was not significantly different in attractivity compared to (E,Z)-MD with racemic chalcogran, indicating no synergistic or inhibitory effects of the inactive isomers of MD.
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    Host plant iridoid-based chemical defense of an aphid,Acyrthosiphon nipponicus, against ladybird beetles (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1837-1845 
    Details
    ISSN: 1573-1561
    Keywords: Defense ; deterrent ; sequestration ; iridoid glycoside ; paederoside ; Acyrthosiphon nipponicus ; Homoptera ; aphid ; Aphididae ; Harmonia axyridis ; Coleoptera ; Coccinellidae ; Paederia scandens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A Rubiaceae-feeding aphid,Acyrthosiphon nipponicus, is seldom attacked by the ladybird beetle,Harmonia axyridis. A potent deterrent against the beetle was isolated from the aphid and identified as paederoside, an iridoid glycoside originating in the aphid's host,Paederia scandens. The iridoid content was as high as 2% of the intact body weight, and a large portion was found in the cornicle secretion.
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    Saw-toothed grain beetleOryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1015-1031 
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    ISSN: 1573-1561
    Keywords: Saw-toothed grain beetle ; Oryzaephilus surinamensis ; Coleoptera ; Silvanidae ; aggregation pheromone ; electroantennogram ; behavioral bioassay ; blend ratio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The antennal and behavioral responses of the saw-toothed grain beetle,Oryzaephilus surinamensis, to the three components of its male-produced aggregation pheromone were investigated. EAG recordings showed no differences between the responses of the two sexes to the synthetic pheromone components. In contrast, laboratory behavioral assays demonstrated marked differences between the sexes. More females than males were consistently attracted to mixtures of the synthetic components, and this bias appeared to be caused by one component in the blend. Altering the blend ratio resulted in changes in the ratio of the sexes attracted. Thus, if, as suggested by preliminary work, males vary the blend produced, this should alter the relative response of the sexes to the aggregation pheromone.
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    URL: http://dx.doi.org/10.1007/BF01015196
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    Oviposition stimulants for the beetle,Monochamus alternatus hope, in inner bark of pine (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 507-516 
    Details
    ISSN: 1573-1561
    Keywords: Monochamus alternatus Hope ; Coleoptera ; Cerambycidae ; pine inner bark ; methanol extracts ; water extracts ; oviposition stimulants ; lightwood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Field and laboratory ovipositional responses ofMonochamus alternatus Hope, respectively, to methanol and water extracts from pine inner bark were examined in comparison with those to pine inner bark, especially using a laboratory-built apparatus for the latter bioassay. Irrespective of the existence of volatiles from paraquat-induced lightwood, pine inner bark and its methanol and water extracts stimulated ovipositional response only in the presence of free moisture.
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    URL: http://dx.doi.org/10.1007/BF01014696
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    Olfactory orientation responses by walking femaleIps paraconfusus bark beetles (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1147-1159 
    Details
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; bark beetles ; Coleoptera ; Scolytidae ; olfaction ; orientation ; anemotaxis ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Synthetic pheromone was released from a dispenser stretched across the width of a wind tunnel. Beetles in pheromone-free wind wandered in all directions and did not appear to orient to the wind. A dosage series showed that pheromone decreased the walking rate and deviations from the upwind direction, and it increased the turning rate. The tracks were composed of relatively straight or gently curving sections interspersed with more infrequent, larger course adjustments. Although pheromone clearly affected the average heading of beetles within a treatment, any given individual exposed to pheromone did not necessarily head directly upwind or maintain a fixed absolute angle with respect to the wind direction. The response appeared to be an inaccurate anemotaxis, rather than an anemomenotaxis.
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    ATP inhibits onset of exocytosis in permeabilised mast cells (1989)
    Springer
    Bioscience reports 9 (1989), S. 99-109 
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    ISSN: 1573-4935
    Keywords: mast cells ; exocytosis ; G-protein ; GE ; calcium ; ATP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract ATP is not required for exocytosis from permeabilised mast cells, and therefore there is no direct role for protein phosphorylation in the late stages of the activation pathway. We have measured the timecourse of exocytosis from permeabilised cells triggered to release hexosaminidase following addition of Ca2+ to cells equilibrated for 2 min with GTP-γ-S. If ATP is included at the time of permeabilisation, then exocytosis commences after a delay, the duration of which depends on the square root of the product [Ca2+][GTP-γ-S], and which may extend to beyond 3 min. When ATP is excluded then the maximal rate of exocytosis is established within 3 secs of completing the effector combination. These results suggest that the achievement of a new steady-state, induced by Ca2+ and GTP-γ-S, and required for exocytosis is inhibited by ATP. From this we conclude that dephosphorylation of an unknown regulator protein may comprise a step in the exocytotic pathway.
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    URL: http://dx.doi.org/10.1007/BF01117516
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    A comparison of bradykinin, angiotensin II and muscarinic stimulation of cultured bovine adrenal chromaffin cells (1989)
    Springer
    Bioscience reports 9 (1989), S. 243-252 
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    ISSN: 1573-4935
    Keywords: secretion ; exocytosis ; chromaffin cell ; calcium ; bradykinin ; angiotensin II, muscarinic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bradykinin, angiotensin II and a mascarnic agonist, acetyl-B-methacholine (methacholine) were all found to elict catecholamine release from cultured bovine adrenal chromaffin cells. Bradykinin was the most potent of these secretagogues and methacholine the weakest, with angiotenin II intermediate in efficacy. All three secretagogues were much less effective than nicotinic stimulation. The three secretagogues all produced a rise in cytoplasmic free calcium concentration ([Ca2+]i), measured with the fluorescent indicator fura2, which was partially independent of external calcium. In the case of bradykinin the full rise in ([Ca2+]i) may involve a component of calcium entry in addition to release of calcium from an internal store. Secretion was also found to be partially independent of external calcium. The different efficacies of the three secretagogues in elicting secretion were correlated with the rise in ([Ca2+]i) produced. The differeing efficacies of the three secretagogues may be due to the extent of release of calcium from an intracellular store which itself is less effective in eliciting secretion than a rise in [Ca2+]i following calcium entry due to nicotine. Bradykinin also stimulates calcium entry, and this may increase the efficacy of the initial rise in [Ca2+]i. Treatment with pertussis toxin resulted in an enhancement of secretion in response to all of the secretagogues.
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    A nonselective cation channel activated by membrane deformation in oocytes of the ascidianBoltenia villosa (1989)
    Springer
    The journal of membrane biology 107 (1989), S. 179-188 
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    ISSN: 1432-1424
    Keywords: stretch-activated channel ; calcium ; oocyte ; development ; patch clamp ; tunicate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Cell-attached patch clamp recordings from unfertilized oocytes of the ascidianBoltenia villosa reveal an ion channel which is activated by mechanical deformation of the membrane. These channels are seen when suction is applied to the patch pipette, but not in the absence of suction or during voltage steps. The estimated density of these stretch-activated channels is about 1.5/μm2, a figure equal to or greater than the density of known voltage-dependent channels in the oocyte. Ion substitution experiments done with combined whole-cell and attached patch recording, so absolute potentials are known, indicate that the channel passes Na+, Ca2+ and K+, but not Cl−. The channel has at least two open and two closed states, with the rate constant that leaves the longer-lived closed state being the primary site of stretch sensitivity. External Ca2+ concentration affects channel kinetics: at low calcium levels, long openings predominate, whereas at high calcium virtually all openings are to the short-lived open state. In multiple channel patches, the response to a step change in suction is highly phasic, with channel open probability decreasing over several hundred milliseconds to a nonzero steady-state level after an initial rapid increase. This channel may play a role in the physiological response of cells of the early embryo to the membrane strains associated with morphogenetic events.
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    URL: http://dx.doi.org/10.1007/BF01871723
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    Role of calcium and calmodulin in the regulation of the rabbit ileal brush-border membrane Na+/H+ antiporter (1989)
    Springer
    The journal of membrane biology 108 (1989), S. 207-215 
    Details
    ISSN: 1432-1424
    Keywords: calcium ; calmodulin ; absorption ; ileum ; brush-border vesicle ; phosphorylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In rabbit ileum, Ca2+/calmodulin (CaM) appears to be involved in physiologically inhibiting the linked NaCl absorptive process, since inhibitors of Ca2+/CaM stimulate linked Na+ and Cl− absorption. The role of Ca2+/CaM-dependent phosphorylation in regulation of the brush-border Na+/H+ antiporter, which is believed to be part of the neutral linked NaCl absorptive process, was studied using purified brush-border membrane vesicles, which contain both the Na+/H+ antiporter and Ca2+/CaM-dependent protein kinase(s) and its phosphoprotein substrates. Rabbit ileal villus cell brush-border membrane vesicles were prepared by Mg precipitation and depleted of ATP. Using a freezethaw technique, the ATP-depleted vesicles were loaded with Ca2+, CaM, ATP and an ATP-regenerating system consisting of creatine kinase and creatine phosphate. The combination of Ca2+/CaM and ATP inhibited Na+/H+ exchange by 45±13%. This effect was specific since Ca2+/CaM and ATP did not alter diffusive Na+ uptake, Na+-dependent glucose entry, or Na+ or glucose equilibrium volumes. The inhibition of the Na+/H+ exchanger by Ca2+/CaM/ATP was due to an effect on theV max and not on theK m for Na+. In the presence of CaM and ATP, Ca2+ caused a concentration-dependent inhibition of Na+ uptake, with an effect 50% of maximum occurring at 120nm. This Ca2+ concentration dependence was similar to the Ca2+ concentration dependence of Ca2+/CaM-dependent phosphorylation of specific proteins in the vesicles. The Ca2+/CaM/ATP-inhibition of Na+/H+ exchange was reversed by W13, a Ca2+/CaM antagonist, but not by a hydrophobic control, W12, or by H-7, a protein kinase C antagonist. we conclude that Ca2+, acting through CaM, regulates ileal brush-border Na+/H+ exchange, and that this may be involved in the regulation of neutral linked NaCl absorption.
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    Ca2+-activated K+ channels from cultured renal medullary thick ascending limb cells: Effects of pH (1989)
    Springer
    The journal of membrane biology 110 (1989), S. 49-55 
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    ISSN: 1432-1424
    Keywords: loop of Henle ; potassium secretion ; channels ; acid/base balance ; thick ascending limb ; calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Ca2+-activated K+ channels were studied in cultured medullary thick ascending limb cells (MTAL) using the patch-clamp technique. The purpose was to determine the effect of acidic pH on channel properties in excised patches of apical cell membrane. At pH 7.4, increasing Ca2+ on the intracellular side or applying positive voltages increases channel open probability. Reducing pH to 5.8 on the intracellular face of the channel decreases channel open probability at each voltage and Ca2+ concentration. Channel mean open times display two distributions and mean closed times display three distributions. Increasing Ca2+ or applying depolarizing voltages lengthens each of the mean open times and shortens each of the closed times. Lowering pH to 5.8 decreases the mean open times and increases mean closed times at each Ca2+ and voltage with the greatest effect on the mean closed times. In contrast, both single-channel conductance and channel kinetics are unaffected when pH is reduced to 5.8 on the extracellular face of the membrane. We conclude that protons interfere with Ca2+ binding to the gate of Ca2+-activated K+ channels reducing the probability of channel opening.
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    Ca2+ and cAMP activate K+ channels in the basolateral membrane of crypt cells isolated from rabbit distal colon (1989)
    Springer
    The journal of membrane biology 110 (1989), S. 19-28 
    Details
    ISSN: 1432-1424
    Keywords: colon ; ion transport ; ion channel ; cyclic nucleotides ; calcium ; potassium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Using patch-clamp techniques, we have studied Ca2+-activated K+ channels in the basolateral membrane of freshly isolated epithelial cells from rabbit distal colon. Epithelial cell clusters were obtained from distal colon by gentle mechanical disruption of isolated crypts. Gigaohm seals were obtained on the basolateral surface of the cell clusters. At the resting potential (approximately −45 mV), with NaCl Ringer's bathing the cell, the predominant channels had a conductance of 131±25 pS. Channel activity depended on voltage as depolarization of the membrane increased the open probability. In excised inside-out patches, channels were found to be selective for K+ over Na+. Channel activity correlated directly with bath Ca2+ concentration in the excised patches. Channel currents were blocked by 5mm TEA+ and 1mm Ba2+. In cell-attached patches, after addition of the Ca2+ ionophore A23187, which increases intracellular Ca2+, open probability was markedly increased. Channel activity was also regulated by cAMP as addition of 1mm dibutyryl-cAMP in the bath solution in cell-attached patches increased channel open probability over 20-fold. Channels that had been activated by cAMP were further activated by Ca2+. We conclude that the basolateral membrane of epithelial cells from descending colon contains a class of potassium channels, which are regulated by intracellular Ca2+ and cAMP.
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    RPLC retention of 1,ω-di(alkoxy)-polysulphides (1989)
    Springer
    Chromatographia 27 (1989), S. 27-30 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; 1,ω-Di(alkoxy)-polysulphides ; Retention contributions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The reaction of S2Cl2 with alcohols yields products, the reversed-phase liquid chromatograms of which are similar to those of dialkyl-polysulphides RSnR, i.e., they represent homologous series. Four of the products were identified via GC-MS as 1,ω-di(alkoxy)-polysulphides having the general structure ROSnOR. Retention contributions of alkyl groups R and sulphur atoms in the −Sn — chain are not much different from values observed with polysulphides. The effect of oxygen, however, is only about −100 index units per O atom, while in dialkyl ethers values of −500 units have been reported.
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    A practical description of retention in reversed phase chromatography using four parameters (1989)
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    Chromatographia 27 (1989), S. 5-14 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Retention behaviour ; Column parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Retention of small molecules on reversed phase or other hydrophobic stationary phases can be represented by k′ values of members of a homologous series at varying solvent compositions. The evaluation of simple linear relationships leads to the introduction of a set of four parameters that contain all the information about retention behaviour of this homologous series in the binary solvent system chosen. It is possible to extrapolate to a hypothetical non-hydrophobic molecule and a solvent, the polarity of which equals that of the stationary phase, to characterize the properties of the stationary phase — eluent system. In addition, a chromatographic method for determination of the phase ratio of the column is proposed.
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    Purification of human chorionic gonadotropin hormone by anion-exchange high-performance liquid chromatography (1989)
    Springer
    Chromatographia 27 (1989), S. 601-604 
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    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Anion exchange separation ; Preparative separations ; Human chorionic gonadotropin hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A high-performance liquid chromatography (HPLC) method was developed for the purification of 50mg crude human chorionic gonadotropin (HCG) hormone sample in one chromatographic run on a 250×10 mm SERVA DEAE Poliol-Si-500 column. During the 60-minute linear gradient of 0.05 M sodium sulfate, 0.05 M sodium hydrogen sulfate and 0.05% (v/v) acetonitrile in buffer “B” complete separation was accomplished in 40 min. Identity and purity of the fractions were checked by SDS electrophoretic method. The eluted HCG fractions were dialyzed for 24 hours to remove the buffer salts and liophilized. The activity of the hormone did not decreased significantly during the purification procedure.
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    Ca2+ interaction with phospholipid bilayers studied by multifrequency phase fluorometry (1989)
    Springer
    Bioscience reports 9 (1989), S. 497-502 
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    ISSN: 1573-4935
    Keywords: calcium ; phosphatidate ; DPH ; phase fluorometry ; distributional analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Calcium interaction with phospholipid membranes containing phosphatidic acid is studied by multifrequency phase fluorometry, using DPH as fluorescent molecule. DPH decay is analysed by a continuous distribution of lifetimes. The results suggest an increase of membrane heterogeneity at low calcium concentrations, without changes in the polarity of the environment surrounding the probe.
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    Calcium absorption in man: Some dosing recommendations (1989)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 17 (1989), S. 631-644 
    Details
    ISSN: 1573-8744
    Keywords: calcium ; absorption ; efficiency ; dosing ; regimens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The absorption of calcium involves a saturable (active) and a nonsaturable (passive) component. The work of several investigators indicates that an inverse relationship exists between calcium intake and absorption efficiency. Human calcium absorption data from the literature were analyzed using a model which included both an active and a passive absorption component. Simulations were provided to illustrate the suitability of this model, and another previously reported model, to fit the data and to estimate the absorption efficiency of calcium when using different dosing regimens. Comparisons of the values predicted in this study with some literature values are provided and some assumptions and potential limitations associated with the use of this method are discussed. The division of the daily dose into equal increments taken at equally spaced intervals over the course of the day is recommended as a useful procedure for increasing the absorption efficiency and efficacy of calcium.
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    Presence of long-chain dialkyl ethers in cuticular wax of the Australian chrysomelid beetleMonolepta australis (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 255-263 
    Details
    ISSN: 1573-1561
    Keywords: Monolepta beetle ; red-shouldered leaf beetle ; Monolepta australis ; lipid extract ; unsaturated aliphatic ethers ; 7-octadecenyl alkyl ethers ; gas chromatography-mass spectrometry ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Investigation of the lipid extract of the Australian chrysomelid beetle,Monolepta australis, has revealed a novel homologous series of long-chain, unsaturated-saturated dialkyl ethers in the cuticular wax. Gas chromatography-mass spectrometry, proton magnetic resonance, infrared spectroscopy, and chemical degradation have shown that ethers of formula CH3(CH2)9CH=CH(CH2)6O(CH2)12–16CH3 predominate.
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    Inter- and intrapopulation variation of the pheromone, ipsdienol produced by male pine engravers,Ips pini (Say) (Coleoptera: Scolytidae) (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 233-247 
    Details
    ISSN: 1573-1561
    Keywords: Ips pini ; Coleoptera ; Scolytidae ; aggregation pheromone ; ipsdienol ; geographic variation ; intrapopulation variation ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We determined the chirality of ipsdienol in individual male pine engravers,Ips pini (Say), from New York, California, and two localities in British Columbia (BC). Both quantity and chirality of ipsdienol varied significantly between and within populations ofI. pini. Beetles from California and southeastern BC produced primarily (R)-(−)-ipsdienol with mean ratios of (S)-(+) : (R)-(−) of 9 : 91 and 11 : 89, respectively, while beetles from New York produced primarily (S)-(+)-ipsdienol with a mean (S)-(+) : (R)-(−) ratio of 57 : 43. A population from southwestern BC was unlike any other known western population, producing primarily (S)-(+)-ipsdienol with a mean (S)-(+) : (R)-(−) ratio of 66 : 34. In contrast to the unimodal chirality profiles for ipsdienol production in populations from California and southeastern BC, the profiles of the populations from southwestern BC and New York were bimodal, with a common mode at approximately 44 : 56 (S)-(+) : (R)-(−). Bimodality in the profiles of ipsdienol chirality in two populations ofI. pini and remarkably high levels of intrapopulation variation in pheromone chirality in all four populations suggest that evolutionary change in pheromone channels of communication could occur, possibly in response to artificial selection pressures such as mass trapping.
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    Attraction of scolytids and associated beetles by different absolute amounts and proportions of α-pinene and ethanol (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 807-817 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Tomicus piniperda ; Trypodendron lineatum ; Hylurgops palliatus ; Thanasimus formicarius ; host attraction ; host volatiles ; ethanol ; α-pinene ; synergism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The attraction of bark and ambrosia beetles as well as associated beetles to α-pinene and ethanol was studied in field experiments with flight barrier traps. α-Pinene and ethanol were released individually and as combinations in approximately 1∶1 or 1∶10 ratios and at four different release rates. Ethanol attractedTomicus piniperda (L.),Hylurgops palliatus (Gyll.),Trypodendron lineatum (Oliv.),Hylastes cunicularius Er.,H. brunneus Er.,H. opacus Er., andAnisandrus dispar (F.) (Scolytidae);Glischrochilus quadripunctatus (L.) andEpuraea spp. (Nitidulidae);Thanasimus formicarius (L.) (Cleridae); andRhizophagus depressus (F.) (Rhizophagidae). α-Pinene attracted all these species with the exception ofT. lineatum, H. cunicularius, andA. dispar. Combinations of a-pinene and ethanol resulted in synergistically increased attraction of all species with the exception ofH. opacus andA. dispar. A. dispar, the only hardwood-associated species in the study, was repelled by α-pinene. Both the release rates and the ratio at which the two substances were released influenced the response of the beetles. The differences in response between the beetle species seem to reflect dissimilarities in the release of the two substances among the various types of breeding material to which the species are adapted.
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    Olfactory orientation responses by walking femaleIps paraconfusus bark beetles I. Chemotaxis assay (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 3-24 
    Details
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; Coleoptera ; Scolytidae ; bark beetles ; taxis ; chemotaxis ; orientation ; olfaction ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Gas-liquid chromatography of the air within the arena developed for this assay showed that a concentration gradient was established within 1–2 min of applying the pheromone (ipsenol, ipsdienol,cis-verbenol), and that this gradient was nearly constant for 20–95 min after application. The concentration fell rapidly and approximately exponentially between the source and the center of the arena. Turning rate and the number of beetles that reached the source increased, and heading with respect to the source decreased, in the presence of pheromone. Responses of beetles that did and did not reach the source were significantly different, but within each group there were no significant differences among dosages. Turning rate and heading varied little with distance from the source, while walking rate decreased as distance from the release point of the beetles increased. We hypothesize that dosage exerts its major effect on source location by altering the probability that a beetle will enter into orientation behavior and that beetles orienting to sources have similar behaviors even when orienting to a wide range of dosages.
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    Counterturns initiated by decrease in rate of increase of concentration (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 183-208 
    Details
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; Coleoptera ; Scolytidae ; bark beetles ; olfaction ; orientation ; counterturning ; chemotaxis ; taxis ; pheromones ; tropotaxis ; schemakinesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The position of beetles were marked at 1-sec intervals after they were released in still air 16–18 cm from point sources of pheromone. Characteristics of the tracks were quantified and compared to those that might be produced by counterturning schemakinesis, tropotaxis, klinotaxis, zigzagging, look-and-leap, or steepest-ascent schemakinesis mechanisms. The beetles' movements were highly irregular, but they turned almost continually and never fixed on a heading near 0° (=straight towards the source). Turn angle sizes increased slightly with absolute size of heading but had the opposite sign, thus compensating slightly for heading. Their distribution was centered about 0° and was unimodal. Heading decreased gradually as the source was neared, but the decrease became steeper within 1–5 cm of the source. Histograms showed that the maximum headings between occurrences when the beetle was headed directly towards the source (0°) were centered around 0° and most of them were less than 90°. However, maximum headings between 90° and 180° were not uncommon. Turn radius decreased as the source was neared. The counterturning mechanism was the most consistent with these observations. An analysis of rate of change of concentration with respect to heading and distance to the source further demonstrated that the counterturning mechanism could explain the form of the decrease in heading as the source was neared, if the major cue used to initiate counterturns was a decrease in the rate of increase of concentration. The tropotaxis could not recreate the form of the decrease, under any form of stimulus processing.
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    Volatiles released from individual spruce bark beetle entrance holes Quantitative variations during the first week of attack (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 2465-2483 
    Details
    ISSN: 1573-1561
    Keywords: Ips typographus ; Coleoptera ; Scolytidae ; Picea abies ; aggregation pheromones ; host tree resistance ; tree-switching ; GC-MS ; monoterpenes ; 2-methyl-3-buten-2-ol ; cis-verbenol, verbenone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Volatiles released from individual entrance holes of eight spruce bark beetles (Ips typographus) were collected during the first week of attack on a resistant host tree. In order to quantify the release of the highly volatile 2-methyl-3-buten-2-ol (MB) from attacking males, a new method was developed with deuterated quantification standard released at the time of collection. The amounts of collected volatiles, as analyzed by GC and GC-MS, showed a large variation between individual holes and also between subsequent entrainments from the same hole. Most of the quantified compounds on the average have two maxima, with a pronounced intervening depression. The amounts of releasedcis-verbenol (cV) increased five times during the first two days, while the amounts of MB were consistently high. The attacked spruce tree was not taken by the beetles, and the average amounts of the two aggregation pheromone components, MB and cV, increased again after the first maxima. The first peak of oxygenated monoterpene, released in the beginning of the attack containing α-terpineol, terpinen-4-ol, bornyl acetate,trans-pinocarveol, and verbenone, was possibly due to spontaneous oxidation of monoterpene hydrocarbons from the tree. Microorganisms established in the gallery wall phloem probably participated in the production of oxygenated monoterpenes during the second increase.
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    URL: http://dx.doi.org/10.1007/BF01020377
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    Receptor chirality and behavioral specificity of the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae), for its pheromone, (+)-grandisol (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 517-528 
    Details
    ISSN: 1573-1561
    Keywords: Boll weevil ; olfaction ; receptor cell ; Anthonomus grandis ; Coleoptera ; Curculionidae ; enantiomer ; grandisol ; chirality ; electroantennogram ; aggregation pheromone ; neurobiology ; structure-activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electrophysiological recordings from antennal olfactory receptors and field behavioral experiments showed both male and female boll weevils,Anthonomus grandis Boh. (Coleoptera: Curculionidae), to respond specifically to (+)-grandisol, an enantiomer of compound I of the boll weevil aggregation pheromone. Single-cell recordings revealed antennal olfactory neurons in both male and female weevils keyed to (+)-grandisol. Electroantennograms in response to serial dilutions of the grandisol enaniiomers showed a threshold 100 to 1000 times lower for (+)-grandisol relative to its antipode. In field behavioral experiments, both sexes were significantly more attracted to (+)-grandisol in combination with the three other pheromone components than the combination with (−)-grandisol. When (−)-grandisol was placed with the (+)-enantiomer at equal dosages, a slight although statistically insignificant inhibition occurred. Subsequent field tests showed that the low level of attraction exhibited by (−)-grandisol in combination with the other three pheromone components could be attributed to the other three components alone. These results are in contrast with an earlier study, which found (−)-grandisol to be as attractive as the (+)-enantiomer.
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    URL: http://dx.doi.org/10.1007/BF01014697
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    Collection of pheromone from atmosphere surrounding boll weevils,Anthonomus grandis (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 767-777 
    Details
    ISSN: 1573-1561
    Keywords: Anthonomus grandis ; behavior ; boll weevil ; Coleoptera ; cotton ; cultivar ; Curculionidae ; effluvial method ; grandlure ; pheromone ; Pora-pak Q ; pheromone collection ; aeration collection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An effluvial method was developed to collect the pheromone, grandlure from actively calling male boll weevils,Anthonomus grandis Boheman. The adsorbant, Porapak Q (ethylvinylbenzene-divinylbenzene), was utilized to trap and concentrate the pheromone. Captured pheromone was desorbed from columns packed with Porapak Q by elution withn-pentane and quantified by capillary column gas-liquid chromatography. In recovery studies with known amounts of synthetic grandlure, we found that the amount of each pheromone component collected was a function of collection duration, elution volume, and initial concentration. This effluvial method was capable of recovering as much as 94.9% of a known quantity (80 μg) of grandlure. The chromatograms were free of extraneous peaks. In studies of insect-produced pheromone, the effluvial method was used to collect pheromone from the air space surrounding male boll weevils as they fed on flower buds from CAMD-E cotton. The quantity and quality of boll-weevil-produced pheromone was determined for days 6, 8, 10, 11, 12, 13, and 14 of boll weevil adulthood. The maximum quantity of natural pheromone was produced on day 13 (4.2 μg/weevil) with a pheromone component ratio of 2.41∶2.29∶0.95∶1 for components I, II, III, and IV, respectively. The effluvial method described in this report is an efficient method to collect and quantify boll weevil pheromone from the atmosphere surrounding actively calling insects. Other applications of this method are suggested.
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    URL: http://dx.doi.org/10.1007/BF01014717
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    Differential recognition of geometric isomers by the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Evidence for only three essential components in aggregation pheromone (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 529-540 
    Details
    ISSN: 1573-1561
    Keywords: Boll weevil ; Anthonomus grandis ; aggregation pheromone ; multicomponent ; behavior ; electroantennogram ; neurobiology ; structureactivity ; geometric isomers ; cotton ; Coleoptera ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract For two decades, the aggregation pheromone of the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae), was thought to consist of four compounds: I [(+)-(Z)-2-isopropenyl-1-methylcyclobutane ethanol]; II [(Z)-3,3-dimethyl-ΔI,β-cyclohexane ethanol]; III [(Z)-3,3-dimethyl-Δ1,α-cyclohexane acetaldehyde); and IV [(E)-3,3-dimethyl-Δ1,α-cyclohexane acetaldehyde). Evidence is presented from behavioral and electrophysiological studies to show that only three of these components, I, II, and IV, are essential for attraction. Competitive field tests, in which each possible three-component blend was tested against the four-component mixture, demonstrated that omission of I, II. or IV resulted in decreased trap captures (P 〈 0.01). Trap captures by these blends lacking I, II, or IV resembled those by the hexane solvent alone in a similar experiment. However, omission of III did not significantly alter field attractiveness of the blend. Dosage-response curves constructed from electroantennogram responses of both males and females to serial dilutions of III, IV, and a 50∶50 mixture of the geometric isomers III and IV showed both sexes to be 10- to 100-fold more sensitive to IV than III. Data from the electrophysiological studies were consistent with a single acceptor type for the (E)-cyclohexylidene aldehyde, IV, for males, and possibly one or two acceptor types for III and IV for females. Possible roles for the (Z)-cyclohexylidene aldehyde, III, and implications for the pheromonal attractant currently used in boll weevil eradication/suppression programs are discussed.
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    URL: http://dx.doi.org/10.1007/BF01014698
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    Inhibition of attraction to aggregation pheromone by verbenone and ipsenol (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 2263-2277 
    Details
    ISSN: 1573-1561
    Keywords: Aggregation pheromone ; Ips typogmphus ; Coleoptera ; Scolytidae ; density regulation ; inhibitor ; verbenone ; ipsenol ; ipsdienol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The semiochemicals verbenone (Vn), ipsenol (Ie), and ipsdienol (Id), present in late phases of host colonization, have been implicated as qualitative “shut-off” signals regulating attack density. Combinations of the three chemicals were released in pipe traps together with the aggregation pheromone components 2-methyl-3-buten-2-ol (MB) andcis-verbenol (cV) at different levels and in different ratios to MB + cV, and with two spacings of traps to test for possible effects on reducing catch at traps baited with aggregation pheromone. When they were released with the attractants Vn and Ie (alone or together) decreased the mean catch significantly at the higher release rates used (1 mg/day). Id alone or together with Vn at low release rates (0.1 mg/day), with the attractants, increased catch somewhat. A dose-response test of Vn, with the attractants held constant, showed a decline in catches, down to about 〈 10% of the control, at ratios of Vn to cV between 1∶1 and 150∶ 1. A larger spacing (25 m) of traps gave a stronger response to change in doses of Vn and MB + cV than a smaller (6 m) spacing. The sex ratio was more skewed towards females when two or three inhibitors were present and at higher doses of Vn. It is suggested that Vn could be the most important density-regulating signal in the natural system, as release of Vn from galleries is larger and starts earlier than that of Id and Ie.
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    URL: http://dx.doi.org/10.1007/BF01014114
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    Terpene alcohol pheromone production byDendroctonus ponderosae andIps paraconfusus (Coleoptera: Scolytidae) in the absence of readily culturable microorganisms (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1433-1463 
    Details
    ISSN: 1573-1561
    Keywords: Dendroctonus ponderosae ; Ips paraconfusus ; Coleoptera ; Scolytidae ; pheromones ; terpene alcohols ; axenic-rearing ; bark beetles ; microorganisms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Dendroctonus ponderosae Hopkins andIps paraconfusus Lanier of both sexes produced most of their complement of terpene alcohols at normal to elevated levels in the absence of readily culturable microorganisms. However, there was some evidence that microbial involvement may be required by maleI. paraconfusus to produce ipsenol and ipsdienol at normal levels. Increased levels of certain terpene alcohols found in axenically reared or streptomycin-fed beetles suggest that symbiotic microorganisms may be responsible for breaking down pheromones and other terpene alcohols. There was also evidence for microbial involvement in the production of the antiaggregation pheromone verbenone inD. ponderosae. This compound was not produced in quantifiable levels by axenically reared or streptomycin-fed beetles exposed to α-pinene as vapors or through feeding, but was found in wildD. ponderosae exposed to α-pinene through feeding on bolts of lodgepole pine,Pinus contorta var.latifolia Engelmann.
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    Secondary attraction and field activity of beetle-produced volatiles inDendroctonus terebrans (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 1513-1533 
    Details
    ISSN: 1573-1561
    Keywords: Dendroctonus terebrans ; Coleoptera ; Scolytidae ; bark beetles ; pheromones ; primary attraction ; secondary attraction ; host selection ; frontalin ; exo-brevicomin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Controlled infestation ofDendroctonus terebrans (Olivier) on bolts of slash pine,Pinus ellionii Engelm. var.elliottii, elicited greater attraction of wild conspecifics than uninfested bolts. Secondary attraction was not apparent, however, to standing slash pines that had received volunteer attacks, when compared with attraction to unattacked but susceptible trees. Hindguts from in-flight or attacking femaleD. terebrans contained frontalin, and those from in-flight or attacking males containedexo-brevicomin.Trans-pinocarveol,cis-verbenol,trans-verbenol, myrtenal, verbenone, myrtenol, and other compounds were produced by both sexes during gallery construction in host trees. Synthetic frontalin, when deployed with a standard host odor mixture of turpentine and ethanol, was very attractive to maleD. terebrans in field-trapping experiments. The addition of eitherexo-brevicomin orendo-brevicomin to the frontalin-turpentine combination negated the attractive effect of frontalin for males.Trans-verbenol, myrtenol, and verbenone had little effect onD. terebrans behavior. Responses of females did not differ among treatments in any of the 11 field experiments.
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    Electroantennograms by mountain pine beetles,Dendroctonus ponderosae Hopkins, exposed to selected chiral semiochemicals (1989)
    Springer
    Journal of chemical ecology 15 (1989), S. 2089-2099 
    Details
    ISSN: 1573-1561
    Keywords: Olfaction ; chirality ; pheromone ; semiochemical ; enantiomer ; bark beetle ; electrophysiology ; electroantennogram ; mountain pine beetle ; Dendroctonus ponderosae ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennograms (EAGs) were recorded fromD. ponderosae to the enantiomers of the terpenoid bark-beetle pheromonestrans-verbenol,cis-verbenol, verbenone, and the bicyclic ketals frontalin,exo-brevicomin, andendo-brevicomin. Male and female responses to enantiomers of the terpenoids differed significantly only at the two highest concentrations. No sex differences were seen in response to the bicyclic ketals. Significantly different responses to the enantiomers of all the chemicals, except frontalin, were noted over at least part of the dosage-response ranges tested. The negative antipode for all of the terpenoids elicited higher responses, while for the bicyclic ketals, the positive antipode effected the largest responses except for the two highest concentrations ofexo-brevicomin.
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    URL: http://dx.doi.org/10.1007/BF01207440
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    Energy calculations and computer modeling of chromatographic separations on microcrystalline cellulose triacetate (1989)
    Springer
    Chromatographia 27 (1989), S. 77-81 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Microcrystalline cellulose triacetate ; Molecular modeling ; Computer graphics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Molecular modeling and energy calculations have been used to study the chromatographic separation of aromatic compounds on microcrystalline cellubose triacetate. A linear relationship has been found between the logarithms of the capacity factors and the energy values of the interaction of these compounds with this stationary phase. The interaction energies have been calculated for two different spatial dispositions of the solutes in relation to the sorbent.
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    URL: http://dx.doi.org/10.1007/BF02290410
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    A chemically bonded liquid crystal as a stationary phase for high performance liquid chromatography. Synthesis on silica via an organochlorosilane pathway (1989)
    Springer
    Chromatographia 27 (1989), S. 559-564 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Liquid crystals ; Synthesis of new bonded phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A compound which becomes a liquid crystal when bonded to a polysiloxane was reacted with dimethylchlorosilane to produce a reagent suitable for bonding to a silica surface. After the silanization reaction was complete, the product was characterized by elemental analysis, diffuse reflectance Fourier transform Infrared Spectroscopy (DRIFT), CP/MAS carbon-13 NMR and differential scanning calorimetry (DSC). Preliminary chromatographic testing was done by retention index measurements using the alkylarylketone homologous series and by measuring the separation factor, α, for anthracene/phenanthrene at two different mobile phase compositions.
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    Physico-chemical applications of HPLC (1989)
    Springer
    Chromatographia 27 (1989), S. 633-638 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Adsorption isotherms ; Equilibria criteria ; Silica and carbon adsorbents ; Aromatic compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Examples of high-performance liquid chromatography (HPLC) are given for the determination of adsorption equilibrium and distribution coefficients, calculation of excess adsorption isotherms from solutions ranging from 10−7 to 10−1 mole fraction, changes in activity coefficient of the component predominantly adsorbed from solution and substitution enthalpy. These examples stem from studies of HPLC and the static adsorption of benzene, anisole and benzaldehyde from solutions in n-heptane on macroporous silica and active carbon at various temperatures. A criterion is suggested for evaluating equilibrium in the HPLC process. The potential of size-exclusion chromatography (SEC) for evaluating the volume and predominant diameter of adsorbed pores as well as pore diffraction are discussed. Prospects for HPLC application to molecularstructural analysis and other purposes are discussed briefly.
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    The use of large polycyclic aromatic hydrocarbons to study retention in non-aqueous reversed-phase HPLC (1989)
    Springer
    Chromatographia 27 (1989), S. 118-122 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Reversed-phase chromatography ; Non-aqueous reversed-phase chromatography ; Polycyclic aromatic hydrocarbons ; Solvent strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Elution strengths of 11 common HPLC solvents on a polymeric C18 phase were compared using a marker set of polycyclic aromatic hydrocarbons. Naphthalene, pyrene, benzo[ghi]perylene, and three larger naphthologues of 8, 10, and 12 rings (constituting a “naphthalene zigzag” series) were chosen because they span the solvent strength range up to and including the strongest solvents, tetrahydrofuran (THF) and chlorobenzene. Four pairs of similarly shaped isomers were used to probe solvent selectivity. With the exception of THF, HPLC solvent strength correlated with observed red shifts of fluorescence band maxima in each solvent. For THF, the pure solvent and blended mixtures behaved quite differently.
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    The case of the elusive tm values in HPLC (1989)
    Springer
    Chromatographia 27 (1989), S. 156-158 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Mobile phase retention time ; Capacity factor ; Negative capacity factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Numerous ideas and procedures have been suggested in the literature for the determination of tm, the retention time of a non-retained species, in high-performance liquid chromatography. In some cases chromatograms have been obtained showing sample components eluting prior to the assumed non-retained species. This phenomenon results in apparent negative capacity factors for the species in question. We have proposed a method employing small inorganic anions which results in a limiting value for tm and eliminates apparent negative capacity factors.
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    URL: http://dx.doi.org/10.1007/BF02265868
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    Equilibrium structures of the Arg-aldehyde moiety upon HPLC of peptides (1989)
    Springer
    Chromatographia 27 (1989), S. 228-232 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Reversed-phase ; 13C n.m.r. ; Arginine-aldehyde peptides ; GYKI-14166
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary High-performance liquid chromatographic and13C n.m.r. spectrometry methods were used for the investigation of peptides containing arginine-aldehyde moiety. Investigation of a model compound, N-benzoyl-Arg-H, showed that in an acidic mobile phase peptides containing the arginine-aldehyde group elute in three characteristic peaks. The components of the peaks were found to be constituents of an equilibrium mixture. The structures of the two components were identified, one as the aldehyde hydrate, the other as the cyclanol derivative. The reactivity of TRIS (HCl) buffer at pH 8.5 with the arginine aldehyde moiety was used for the assignment of the equilibrium structures.
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    Ion-pair reversed phase HPLC determination of nucleotides, nucleosides and nucleobases — Application to nucleotide metabolism in hepatocytes (1989)
    Springer
    Chromatographia 27 (1989), S. 639-643 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Reversed-phase ; Ion-pair ; Recoveries ; Hepatocytes ; Purine compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Three groups of metabolites were analyzed in extracts of rat hepatocytes by an HPLC method: (i) nucleotides (ATP, ADP, AMP, GTP, GDP, UTP, UDP, IMP, UMP), (ii) nucleosides and nucleobases (adenosine, adenine, guanosine, inosine, xanthine, hypoxanthine, uridine) and (iii) inhibitors of xanthine oxidoreductase (oxypurinol, allopurinol). Perchloric acid extracts were neutralized with K2CO3/triethanolamine and analyzed at 254 nm by reversed-phase ion-pair high-performance liquid chromatography. The nucleotides and their derivatives were separated with a gradient elution using 10 mM NH4H2PO4/2 mM t-butylammonium-phosphate and acetonitrile. Recovery values were estimated for the extraction procedure used. The method was applied to the investigation of nucleotide metabolism of hepatocytes of starved rats at anoxia and reoxygenation.
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    Preparation of silica-based cation-exchangers for use in ion chromatography (1989)
    Springer
    Chromatographia 27 (1989), S. 316-320 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Ion chromatography ; Silica-based cation-exchanger ; Trimethylsilyl chlorosulfonate ; Lanthanides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A low exchange-capacity, silica-based cation-exchanger for use in ion chromatography has been synthesized. (p-Trimethylsilyl)benzyl-dimethylchlorosilane (TBDCS) reacts with trimethylsilyl chlorosulfonate (TMCS) to produce a compound sulfonated in the para position of the type ArSO2OSi (CH3)3, which is bonded to 5 μm porous silica beads and hydrolysed to the corresponding arylsulfonic acid. The product is hydrophilic and has a high degree of sulfonation, efficiencies of packed columns reaching about 40,000–50,000 plates per meter for the separation of the Mn2+ ion. The new stationary phase has been applied to the ion chromatography of some organic and inorganic ions. It is notable that 14 lanthanides can be separated by isocratic elution about one hour on a 150×4·6 mm column, with 4 mM ethylenediamine and 6 mM α-hydroxyl-isobutanoic acid (pH 3.67) as mobile phase.
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    Enhanced chemiluminescence detection of some dansyl amino acids in liquid chromatography (1989)
    Springer
    Chromatographia 27 (1989), S. 191-193 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Dansyl amino acids ; Chemiluminescence ; Bis(2,4,6-Trichlorophenyl)oxalate, (TCPO) ; Enhancement of luminescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The dansylated amino acids alanine, glutamic acid, methionine and norleucine were separated by reversedphase HPLC and detected via chemical excitation using the post-column, TCPO-peroxyoxalate reaction system. Enhancement of the chemiluminescence emission was achieved by including the surfactant Triton X-100 in the eluent.
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    Measurement of elastin hydrolysis by reverse-phase HPLC with on-line post-colum derivatization (1989)
    Springer
    Chromatographia 27 (1989), S. 225-227 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Reverse-phase chromatography ; Elastin Hydrolysis measurement ; On-line post-column derivatization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Excessive breakdown of elastin, a structural protein, may be related to aortic disease and emphysema. Since L-valyl-L-proline occurs in high concentrations in elastin, a rapid and sensitive method using HPLC with post-column on-line derivatization was used to measure the dipeptide from swine aortic tissue, and the amount of elastin present was determined. Elastin was extracted by alkaline hydrolysis. After neutralization and filtration, the sample was injected onto a ODS-2 gel column, and the dipeptide was eluted by a linear gradient of 0 to 10% of 1-propanol in 50 mM heptafluorobutyrate, pH 3, at a flow rate of 1 ml/min. The eluent was reacted with fluorescamine at pH 8.6, and fluorescence was detected at an excitation wavelength of 395 nm and a 455 nm cutoff emission filter.
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    Separation and purification of porcine pancreatic enzymes by serial operation of ion-exchange and affinity columns (1989)
    Springer
    Chromatographia 27 (1989), S. 449-454 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Ion exchange and affinity columns in series ; Porcine pancreatic enzymes ; Trypsin and elastase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In order to separate and purify some of the enzymes contained in porcine pancreas, operation of an ion-exchange column in series with an affinity column has been used. The enzymes dealt with possess very similar molecular weights, isoelectric points and active sites. Hence they are difficult to separate and purify by traditional separation and/or purification methods. CM-Sepharose anion-exchange resin adsorbs elastase and trypsin at low pH (4.5) and desorbs them at high pH (9.0) and high ionic strength. Chitin-CHOM affinity adsorbent adsorbs trypsin at high pH (8.0) and desorbs it at low pH (2.5). By virtue of this complementary relationship two chromatographic columns were connected in series for facilitating the separation and purification of elastase and trypsin from porcine pancreas. The result showed that the specific activities of elastase and trypsin had been increased 16 and 22 fold respectively.
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    Anion exchange behaviour of hydrous titanium oxide and its use for column separations (1989)
    Springer
    Chromatographia 27 (1989), S. 472-474 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Hydrous titanium oxide ; Anion exchange ; Polyvalent anions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Hydrous titanium oxide (HTiO), prepared under varying conditions of precipitation, has been studied for its anion exchange behaviour. Its chemical and thermal stability has been examined. The stoichiometry of uptake for Cl− has been investigated using a36Cl radiotracer and the regeneration power of the exchanger checked. Distribution coefficients for halides and polyvalent anions have been determined and on the basis of sorption data some polyvalent anions have been separated using HTiO columns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02319568
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  • 92
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    An improved HPLC determination of flavonoids in medicinal plant extracts (1989)
    Springer
    Chromatographia 27 (1989), S. 509-512 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Flavonoids ; Crataegus ; Passiflora ; Matricaria ; Ginkgo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Flavonoids of Crataegus monogyna, Passiflora incarnata, Matricaria chamomilla and Ginkgo biloba extracts have been separated by isocratic elution on C18 columns using eluents based on C3 alcohols, tetrahydrofuran or dioxane. Satisfactory results have been obtained at compared to the low resolution achieved with the customary system acetonitrile-water-acetic acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02319574
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  • 93
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    Polymer coated stationary phases for liquid chromatography (1989)
    Springer
    Chromatographia 28 (1989), S. 19-23 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Preparation of stationary phases ; Polymer coated stationary phases ; Polymer-octyl bonded phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Polymethyloctylsiloxane-coated stationary phases have been prepared for liquid chromatography, by thermal reaction. The influence of the reaction conditions on retention and efficiency of test substances with different structures has been discussed. The materials have good stability in both acidic and basic eluents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290376
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  • 94
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    Chromatography based on membrane separation with vesicular packing material (1989)
    Springer
    Chromatographia 28 (1989), S. 561-564 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Size exclusion ; Vesicular packing material ; Proteins and polymers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new vesicular packing material — prepared from plant cell clusters by purification of the intact cell wall framework —is suitable for chromatography, giving high performance at low pressure gradients. The separation is achieved by dialysis through the cell wall, which is an ultrafilter membrane with an extremely sharp size limit of separation. Almost the whole of the stationary liquid phase is located within the vesicle (empty cell) lumina. In contrast to gel filtration vesicle chromatography gives a practically ideal separation of two size groups with an extremely short fractionation range. The size limit of separation was investigated by chromatography of proteins and other polymers. Group separation of molecules of a polydisperse dextran standard preparation showed that the critical Stokes' diameter for dextran permeation into the stationary liquid phase of the vesicular packing is 5 to 6 nm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02260677
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  • 95
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    Semi-preparative high-performance liquid chromatographic separation of four 1.1-dimethylethyl 4- and 5-bromo-trans-2-methylcyclohexane-1-carboxylate isomers (1989)
    Springer
    Chromatographia 28 (1989), S. 585-587 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Preparative scale separation ; 1,1-Dimethylethyl 4- and 5-bromo-trans-2-methylcyclohexane-1-carboxylate ; Trimedlure-related isomers ; Ceratitis capitata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A semi-preparative high-performance liquid chromatographic procedure on 5-μm silica was developed for the isolation of gram quantities of four 1,1-dimethylethyl 4- and 5-bromo-trans-2-methylcyclohexane-1-carboxylate isomers (trimedlure-related) for NMR studies and comparative biological evaluation as male medfly,Ceratitis capitata, attractants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02260682
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  • 96
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    Simultaneous determination of pseudouridine and creatinine in urine by HPLC with polarographic detection (1989)
    Springer
    Chromatographia 28 (1989), S. 605-609 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Electrochemical detection ; Pseudouridine ; Creatinine ; Urine analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The anodic behaviour of pseudouridine a modified nucleoside proposed as tumoral marker, has been studied at a mercury electrode. A method for its determination in urine samples by liquid chromatography with indirect anodic polarographic detection has been developed. The method is simple, highly selective and permits the direct injection of urine after dilution (1∶20) with mobile phase. Creatinine, which also gave an anodic response on mercury, could be simultaneously determined and used as an “internal standard” for Psi. This allowed the pseudouridine/creatinine ratio determination in a single run on the same specimen and the use of urine samples collected randomly instead of the 24h collection. The within-day RSD% for pseudouridine/ creatinine peak areas ratio was 3.4%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02260686
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  • 97
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    Investigations into the chromatographic behaviour of silica gels produced from ester silicates (1989)
    Springer
    Chromatographia 28 (1989), S. 9-14 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Ester silicate silica gels ; Behaviour with organic bases ; Silanol groups ; Acidic centres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Silica gels produced from ester silicates (ES-gels) are excellent chromatographic supports. In comparison with other silica gels the RP-materials obtained from them show little peak tailing even with polar, and, in particular, with basic compounds. Gels produced by various manufacturing processes have been classified by adsorption with methyl pyridinium chloride. ES-gels yield very low methyl pyridinium chloride values and small asymmetry parameters. The results indicate that there are strongly acidic, structurally-related surface centres which cause peak tailing on most commercial gels. It was shown that surface silanols on silica gels do not, in themselves, lead to peak tailing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290374
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  • 98
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    Analysis of preservatives in cosmetics—Methylisothiazolones (1989)
    Springer
    Chromatographia 28 (1989), S. 34-38 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Methylisothiazolones ; Preservatives ; Analysis of cosmetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Antimicrobially active formulations based on 2-methyl-3(2H)-isothiazolone and 5-chloro-2-methyl-3(2H)-isothiazolone (Kathon CG, Euxyl K 100) are incorporated into manufactured cosmetics as preservatives. In this paper we report on the analysis of these active components by means of liquid chromatography. It is conventional for the original methylisothiazolone components in cosmetics to be analyzed by reversed phase high-performance liquid chromatography after column chromatographic separation and flash chromatographic purification. In our new analytical method the methylisothiazolones are converted into the respective β-thiosubstituted acrylamide derivatives, which are ionic substances, with the help of the nucleophilic reagent hydrogensulfite. An ion pair high-performance liquid chromatographic method has been developed for the separation and quantification of these derivatives.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290380
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  • 99
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    Nucleotide and aldehyde analysis by HPLC for determination of radical induced damage (1989)
    Springer
    Chromatographia 28 (1989), S. 65-68 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Oxygen radicals ; Nucleotides ; Aldehydes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The analysis of two metabolite groups, nucleotides and aldehydes, is necessary for assessment of oxygen radical metabolism during hypoxia and reoxygenation. Nucleotides and their derivatives were determined by HPLC using gradient elution with 10 mM NH4H2PO4 buffer containing 2 mM t-butylammoniumphosphate and acetonitrile. Aldehydes occuring after lipid peroxidation were analyzed by derivatisation to dinitrophenylhydrazones followed by TLC and HPLC separation with methanol/water on an ODS column.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290385
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  • 100
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    High-performance-liquid chromatographic separation of 1,3,5-trizine herbicides (1989)
    Springer
    Chromatographia 28 (1989), S. 209-211 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Triazine herbicides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A number of 11 triazine herbicides and 7 of their corresponding metabolites were separated in a single HPLC run. The separation was achieved on a reversed-phase column using gradient elution with acetonitrile/buffer. Detection was by UV absorption at a wave-length of 220 nm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02319649
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