ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • pharmacokinetics  (182)
  • Chromatographie, Dünnschicht  (90)
  • Scanning electron microscopy  (77)
  • Springer  (349)
  • American Institute of Physics (AIP)
  • Cambridge University Press
  • 2020-2023
  • 1975-1979  (349)
  • 1935-1939
Collection
Keywords
Publisher
  • Springer  (349)
  • American Institute of Physics (AIP)
  • Cambridge University Press
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 27 (1979), S. 33-40 
    ISSN: 1432-0827
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Planta 146 (1979), S. 203-210 
    ISSN: 1432-2048
    Keywords: Cellulose ; Microfibrils ; Negative staining ; Nicotiana ; Protoplasts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A study has been made of the wall fibrils produced by tobacco protoplasts, using scanning electron microscopy in conjunction with negative staining. It has been shown that the fibres seen in scanning electron microscopy correspond to aggregates of microfibrils. These aggregates are only visible where they are lifted clear of the protoplast surface. Negative staining of fixed protoplasts shows that the aggregation of microfibrils into the fibres visible in scanning electron microscopy is probably produced by air-drying. Gentle disruption of microfibrils produces both random broken fragments and bundles of short pieces of fibrillar material about 60 nm in length. This material is present in undisrupted young walls, but not in undisrupted older walls. The microfibrils in young walls seem much more fragile and liable to breakage than those in older walls. These results are discussed in terms of the interpretation of scanning electron microscope images and the mechanism of cellulose microfibril formation by higher plants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 203-209 
    ISSN: 1432-1041
    Keywords: dantrolene sodium ; spasticity ; twitch tension ; dose response ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Dantrolen sodium is a muscle relaxant, which is used in the treatment of spasticity. Although it is given chronically, little is known about its pharmacokinetic behaviour. The relationship between the effect of a single oral dose of dantrolene sodium and its plasma concentration in healthy volunteers was studied by measuring the effect on the twitch tension, and in spastic patients on the decrease in muscle hypertonia. On the twitch tension dantrolene gave a depression of 49.1±9.4% (±SD) within 1.15 and 3.45 h after ingestion of 100 mg. The mean maximal plasma concentration was 1.24±0.32 µg/ml (±SD). The effect and the plasma concentration were correlated. No relationship between the plasma concentration of dantrolene sodium and its effect could be established in patients, although definite activity in 6 out of 7 patients was observed after a single oral dose of 100 mg, and plasma concentration of dantrolene sodium greater than 0.3 µg/ml were consistently associated with better results than placebo treatment in 6 out of 7 patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 287-293 
    ISSN: 1432-1041
    Keywords: linear system theory ; perfusion model ; cardiac output ; pulmonary extraction ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Assessment of pharmacokinetics in terms of circulatory drug transport is proposed using the methods of linear system theory. In this model-independent approach drug distribution and disposition are characterized by the total extraction ratio, the mean residence time in the body and the volume of distribution at steady state. In analyzing concentration(c)-time(t) data, the procedure requires calculation only of the areas under the c(t)-and c(t)×t-curves to estimate kinetic parameters, and for prediction of the steady state concentration following continuous infusion or multiple doses. Pulmonary clearance of drugs is included in the theory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 275-280 
    ISSN: 1432-1041
    Keywords: Parkinson's disease ; bromocriptine ; pharmacokinetics ; plasma concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma kinetics of bromocriptine (BCT), a long-acting dopamine agonist, was studied in twelve patients with Parkinson's disease, using a newly developed gas chromatographic method of analysis. Each patient received BCT for at least three weeks in a constant but different dose regimen. Concomitant treatment with 1-DOPA was not allowed. During a 6-day hospitalization period, a blood sample was taken immediately before the afternoon dose at 14.00 h (Cmin) to determine the steady-state level. On the 6th day blood samples were collected every hour during two 8 h dose intervals. The results showed a significant correlation between the mean values of the AUC and the Cmin. First order elimination kinetics appeared to be followed by BCT, at least for the plasma concentrations commonly found. Considerable inter-individual variation was demonstrated both for the dose/plasma concentration ratio and for calculated plasma clearances. No serious side-effects were observed during the investigation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1041
    Keywords: indobufen ; platelet aggregation ; food effect on bioavailability ; repeated administration ; pharmacodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of food on bioavailability of indobufen tablets was investigated in 6 healthy volunteers. Subsequently, the same subjects took 100 mg b.i.d. for 7 days. Plasma levels and urinary excretion of indobufen were determined by GLC. Platelet aggregation induced by several concentrations of adrenaline was determined turbidimetrically at various times after the first and last doses. The absorption of indobufen tablets was not substantially impaired by the presence of food in the GI tract, although peak plasma levels and AUCs were slightly reduced after food. Pharmacokinetic analysis of plasma and urinary levels of indobufen did not indicate any change in drug disposition after repeated dosing. Adrenaline-induced platelet aggregation was markedly inhibited for up to 12 h after the first dose and the intensity and duration of this effect did not change after repeated administration. A twice-daily dosing appears suitable for clinical trials.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 341-347 
    ISSN: 1432-1041
    Keywords: clofibrate ; chlorophenoxyisobutyric acid ; disposition ; hepatitis ; cirrhosis ; renal failure ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition of clofibrate over 96 hours was observed following single oral dose in six patients with acute viral hepatitis, six patients with liver cirrhosis, seven patients with renal insufficiency, and six control subjects. No parameter of the disposition of CPIB (active form of clofibrate) was significantly altered in acute hepatitis. In liver cirrhosis, the mean plasma half-life was unchanged compared to controls (20.9 vs. 17.5 h), but plasma clearance of the non-protein bound drug was reduced (115 vs. 243 ml×min−1), plasma protein binding was reduced (92.8 vs. 97.2 percent), and the apparent volume of distribution was increased (0.20 vs. 0.141×kg−1). In renal insufficiency plasma half-life was prolonged 2 to 6-fold, depending on the degree of renal impairment. Total plasma clearance (3.4 vs. 7.1 ml×min−1) and plasma clearance of the unbound drug (81 vs. 243 ml×min−1 were reduced in patients with renal failure, the clearance of the unbound drug being inversely correlated with the serum creatinine concentration. Renal failure was also associated with decreased protein binding and an increased volume of distribution of CPIB, and with reduced urinary excretion of CPIB and its glucuronide metabolite. The dose of clofibrate should be halved in patients with cirrhosis. In renal insufficiency, the dose should be adjusted according to the individual serum creatinine level: only 10 to 15% of the usual weekly dose should be given in complete renal failure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 363-366 
    ISSN: 1432-1041
    Keywords: methotrexate ; protein binding ; ultrafiltration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The protein binding of methotrexate by serum from eight normal volunteers was assessed by continuous ultrafiltration at pH 7.4 and 37°C. Methotrexate concentrations were measured by radioimmunoassay and the data analysed by the method of Scatchard. The major binding protein was albumin which bound 87.3% of the drug in serum. Analysis of the Scatchard plots indicated two distinct groups of binding sites. Class I was found to have 0.16±0.05 (S D) binding sites with an intrinsic association constant of 71.15±35.98 (S D)×104 M−1: Class II had 2.01±0.93 (S D) binding sites and an affinity of 0.18±0.15×104 M−1. No great change in the percentage of methotrexate bound occurred until the total concentration of the drug exceeded 50 µMol 1−1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 243-249 
    ISSN: 1432-1041
    Keywords: timolol ; beta blockade ; pharmacokinetics ; pharmcodynamics ; acute administration ; chronic administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and effects of various oral doses of timolol administered either acutely or after chronic medication for 7 days were studied in healthy volunteers. After acute administration of timolol maximum plasma concentrations were attained within 1–2 h and thereafter declined exponentially with time. The mean apparent half-life of elimination from plasma was 2.5 h and was independent of dose. Area under the plasma concentration-time curve (AUC) was proportional to the orally administered dose. Plasma concentrations, apparent elimination half-life and AUC were not altered after one week of chronic administration. The effect of timolol on heart rate and blood pressure response to three sequentially increasing ‘steady state’ work loads were studied. After acute administration of timolol maximum reduction of systolic blood pressure, resting heart rate, and the different parameters of the work-heart rate (or blood pressure) relationships were produced by 5 mg timolol. Increasing the dose prolonged the duration over which these variables were reduced. The relationship between timolol plasma concentration and inhibition of different parameters of the exercise response was hyperbolic with half maximum inhibition at concentrations of about 3–4 ng/ml of timolol and maximum inhibition above 30 ng/ml. Maximum drug effects and duration of action of timolol on the different variables were similar after acute and chronic administration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 263-270 
    ISSN: 1432-1041
    Keywords: diazepam ; alcoholic beverages ; plasma level ; pharmacokinetics ; co-ordination skills ; red wine ; white wine ; whisky
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twenty paid healthy students ingested diazepam 10 mg 30 min after the administration of ethanol 0.8 g/kg. The alcoholic beverage used was varied in randomized double-blind experiments, which were repeated at one-month intervals. Psychomotor performance, plasma diazepam, and alcohol concentration in breath were measured 30, 60, 90 min and 2, 3, 4, 6 and 24 h after the ingestion of diazepam. Beer and white wine elevated the plasma level of diazepam and the effect lasted for up to 2 h. Whisky elevated the diazepam level for 90 min. Red wine did not affect it significantly. The alcohol-diazepam combination impaired tracking skills and oculomotor co-ordination and enhanced nystagmus, more than diazepam alone. Red wine produced a breath alcohol concentration higher than after white wine. More nystagmus was recorded after red wine and diazepam, although white wine led to a higher plasma diazepam concentration. It appears that simultaneous ingestion of alcohol and diazepam accelerates the absorption of diazepam. This pharmacokinetic alteration may not contribute much to the combined psychomotor effects of diazepam and alcohol, which were mainly due to pharmacodynamic interaction at receptor level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 271-277 
    ISSN: 1432-1041
    Keywords: lithium ; litarex ; single dose ; multiple dose ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary An analysis of the single and multiple dose pharmacokinetics of lithium in 7 healthy volunteers is presented. A solution of lithium chloride was administered in single dose experiments and the same solution and a sustained release preparation were employed in multiple dose experiments, which were carried out at steady state. A fixed dose of 24 mmol was used in the single dose experiments and in the subsequent multiple dose experiments in the same subjects the same dose was administered once daily for a week. Distinct two-compartment characteristics were found, with a mean disposition rate constant (β) of 0.035 h−1±0.010 SD, corresponding to a mean biological half-life of about 19.8 h. The mean half-time of the distributory α-phase was about 1.15 h. The absorption of lithium from an orally administered solution took place with a half-time of about 0.15 h in the single dose experiments. The apparent volume of distribution of the central compartment (Vc) was 0.307 1 kg−1±0.046 SD, less than half that of Vde at equilibrium. Vdβ (Vdarea) was 0.8291 kg−1±0.184 SD and mean total body clearance was 27.6 ml kg−1 h−1±4.7 SD.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 255-262 
    ISSN: 1432-1041
    Keywords: spironolactone ; canrenone ; fluorimetry ; high performance liquid chromatography ; linear kinetics ; saturation kinetics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In Study I 20 normal volunteers received a single oral dose of spironolactone 100 mg. In Study II a further 20 normal volunteers were given first spironolactone 100 mg b.i.d. and subsequently spironolactone 100 mg once a day for a further 4 days. In Study III 5 normal subjects were given a single dose of spironolactone 500 mg. The concentration of canrenone in serum was determined both by fluorimetry and HPLC for 0–48 h in Study I, 120–168 h in Study II and 0–36 h in Study III. The total AUCs after the single 100 mg dose did not differ from the AUCs within the dosing interval during steady state. The half-lives of the terminal log-linear phases were almost identical (14.99±0.80 h and 15.69±0,80 h) when determined by fluorimetry, and were sligthly, but significantly (p〈0.01), longer when determined by HPLC — 20.14±1.62 and 18.71±1.04. The mean ratio of the specific AUC determined by HPLC and the fluorimetrically determined AUC was 0.3 after the single 100 mg dose. It did not differ from the corresponding value during steady state (0.34). In contrast, the ratio after the single 500 mg dose was approximately 50% higher. Fluorimetrically determined AUCs after 100 and 500 mg doses did not show dose-proportionality in contrast to the HPLC-determined AUCs. It was concluded that Canrenone contributes much less to the conventional fluorimetric determination than was previously assumed. It may not provide more than 1/10 and 1/4 of the antimineralocorticoid activity of spironolactone after single dose and multiple doses, respectively. Whereas linear kinetics apply after single and multiple 100 mg doses of spironolactone, after 500 mg saturation kinetics must be assumed with respect to metabolism. Thus, in bioavailability studies high doses of spironolactone should be avoided. For such studies the fluorimetric assay seems to be the appropriate bioanalytical method in spite of its lower specificity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 187-192 
    ISSN: 1432-1041
    Keywords: quinidine ; plasma protein binding ; pharmacokinetics ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition and plasma protein binding of quinidine after intravenous administration were studied in 13 healthy subjects. Plasma protein binding, expressed as the fraction of quinidine unbound ranged from 0.134–0.303 (mean 0.221). Elimination rate constant (β) varied from 0.071 to 0.146 h−1 (mean 0.113), and apparent volume of distribution (Vβ) varied from 1.39–3.20 l · kg−1β (mean 2.27). Total body clearance was 2.32–6.49 ml min−1 · kg−1. There was a positive linear correlation between the plasma fraction of unbound quinidine and both Vβ (r=0.885, p〈0.01) and total body clearance (r=0.668, p〈0.05). No significant correlation existed between the fraction of unbound quinidine in plasma and the elimination rate constant. The results show that both the apparent volume of distribution and total body clearance of quinidine are proportional to the unbound fraction in plasma. This implies that the total plasma concentration of quinidine at steady state will change with alterations in plasma binding, whilst the concentration of unbound compund and its elimination rate will remain unaffected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 153-157 
    ISSN: 1432-1041
    Keywords: cimetidine ; renal failure ; elimination half life ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma concentration curve after a single oral dose of cimetidine 200 mg was followed in 27 patients with varying degrees of chronic renal failure (creatinine clearance 1–52 ml/min) and in 46 patients with normal serum creatinine. Compared to the latter patients, the plasma concentration was higher and the elimination rate was slower in all uraemic subjects, including a group with moderate renal impairment. The preliminary recommendations of dosage for patients with a creatinine clearance below 5 ml/min, and for patients on regular haemodialysis, is cimetidine 200 mg every 12 h, 5–15 ml/min 200 mg every 12 to 8 h, 15–30 ml/min 200 mg every 8 h and 30–52 ml/min 200 mg every 6 h.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-1041
    Keywords: nitrazepam ; epilepsy ; age ; disease ; plasma concentration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma concentrations of nitrazepam were measured by gas-liquid chromatography in: young healthy volunteers, in geriatric and psychiatric patients and in epileptic children. The disposition of nitrazepam was described in terms of a two-compartment open model. After a single oral dose of nitrazepam 5 mg the most prominent differences between the experimental groups were in the β-phase half-life-mean 29 h in the young volunteers and 40 h in geriatric patients, and in the apparent volume of distribution during the β-phase of 2.4 vs 4.8 l/kg. Total plasma clearance and the average steady state concentration in both groups were equal. The plasma level rose at a rate proportional to the β-phase half-life, and so, they were achieved more rapidly in the young than in the old subjects (3.5 vs 7.5 d). No change in steady-state level or in the half-life of nitrazepam were found during long term treatment, which indicates lack of enzyme induction or inhibition. In 95% of the epileptic children with a good to fair clinical response, the plasma concentration of nitrazepam was 40–180 ng/ml (mean 114 ng/ml). As all of the patients were on combined antiepileptic therapy, no attempt was made to correlate plasma level with therapeutic response.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 175-180 
    ISSN: 1432-1041
    Keywords: clorazepate ; nordiazepam ; pregnancy ; pharmacokinetics ; intramuscular injection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A single dose of clorazepate 20 mg was injected i.m. in 7 pregnant and 7 non-pregnant women. Blood samples were collected for one week, and urine was collected for 24 h after the dose. The concentrations of clorazepate and its metabolite nordiazepam were determined by electron capture gas liquid chromatography. There was no difference between the two groups on physical examinations. Clorazepate was rapidly absorbed and the peak concentration was reached within 2h. Mean pharmacokinetic parameters for clorazepate were absorption half life 0.77h in pregnant women and 0.56h in non-pregnant women; elimination half life 1.3h in pregnant women and 2.0h in non-pregnant women; volume of distribution: 0.43 l · kg−1 in the pregnant women and 0.33 l · kg−1 in non-pregnant women. Nordiazepam reached its peak concentration within 12h after dosing; its mean half life of elimination was 180h in pregnant women and 60h in non-pregnant women. Within 24h, 1.3% of the clorazepate was recovered in urine from pregnant women and 7% in urine from the non-pregnant women.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 257-261 
    ISSN: 1432-1041
    Keywords: cimetidine ; H2-receptor antagonist ; aging ; single dose ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The blood level versus time curve for unchanged cimetidine after a 200 mg oral dose has been determined in 20 apparently healthy subjects, ranging from 22 to 84 years of age. A significant relationship between the area under the curve (AUC) and age was found (r=0.81; P〈0.001). The peak concentrations of cimetidine were significantly inversely related to body weight (r=−0.71; P〈0.001). The age-related increase in bioavailability of oral cimetidine, as measured by AUC, was probably due to decreased total clearance of the drug, which resulted from the opposed changes (by themselves not significant) of distribution volume towards a decrease and of half-life towards an increase with age. Reduction in the standard oral dose of cimetidine by one third to one half should be feasible in the elderly without loss of efficacy, and it may be advisable in order to obviate extreme individual responses that may occur in this population.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    ISSN: 1432-1041
    Keywords: chlorthalidone ; pharmacokinetics ; oral and i.v. doses ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Seven normal human volunteers each received a constant-rate infusion of chlorthalidone for 2 h, and the same (commonly 50 mg) single oral dose on separate occasions. The concentration of unchanged chlorthalidone was analyzed over a 100 to 220 h period in plasma, red blood cells, urine and faeces after both dosage forms. A three compartment model was required to describe the intravenous plasma concentrations in five of the subjects. A two compartment model sufficed to account for the decay of the oral plasma concentrations in all seven subjects. The mean plasma t1/2 after i.v. dosing was 36.5 h (±10.5 SD), and the mean plasma t1/2 after oral doses was 44.1 h (±9.6 SD). The mean red blood cell concentration t1/2 after i.v. doses was 46.4 h (±9.9 SD), and the mean red blood cell t1/2 after the oral doses was 52.7 h (±9.0 SD). The shorter i.v. half-live was not equally manifest in all subjects, being mainly apparent in three of them. In all cases the urinary excretion rate plots were parallel to the plasma concentration curves. As the faster decay after i.v. administration was not accompanied by increased renal clearance, the difference must have been due to non-renal mechanism. The mean total of 65.4 (±8.6 SD) % of the intravenous dose was excreted in urine over infinite time, whereas the mean total excretion after the oral dose was 43.8 (±8.5 SD) %. Faecal excretion ranged from 1.3–8.5% of dose in the i.v. study to 17.5–31.2% of dose in the oral study. The sum of the amounts present in urine plus faeces pointed strongly to an important metabolic route of elimination of chlorthalidone. Bioavailability estimates (F) from three sets of data were — a mean F of 0.61 from plasma concentrations, 0.67 from urinary excretion measurements and 0.72 from the erythrocyte concentrations. Simulations with a non-linear model indicated lesser validity of the estimate from erythrocyte concentrations. It was concluded that the average of plasma and urine data, F=0.64, yielded the best estimate of the oral availability of chlorthalidone 50 mg in man.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 121-125 
    ISSN: 1432-1041
    Keywords: guanethidine ; chronic therapy ; urinary excretion ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma level and urinary excretion rate of guanethidine have been measured in 30 patients during oral maintenance therapy, and in 5 patients following discontinuation of therapy. A significant correlation was found between the daily average urinary excretion and the maintenance dose, although wide interindividual variation was noted among patients maintained on the same dose. A statistically significant correlation was also observed between the area under the plasma level curve during the dose interval and the oral maintenance dose. After discontinuation of chronic therapy, the half-life of 1.5 days of the initial phase of elimination was essentially in agreement with the half-life of almost 2 days determined in acute studies. In addition, a second phase of elimination with a half-life of 4 to 8 days was observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1432-1041
    Keywords: clorazepate ; nordiazepam ; pregnancy ; placental transfer ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Clorazepate 20mg was given i. m. to 49 mothers during the first stage of labour. The elimination of the drug was studied in 27 newborns produced by these mothers. The same dose was given to 13 women who underwent amniocentesis and to 7 women who were breast-feeding. “Total nordiazepam”, i.e. the sum of clorazepate and its metabolite nordiazepam, was determined by gas-liquid chromatography in maternal blood, umbilical cord blood (both arterial and venous), amniotic fluid and in milk. Clorazepate was found to cross the placental barrier slowly, but nordiazepam was transferred more rapidly. Nordiazepam was found in the milk and in the blood of neonates after breast-feeding had started.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 31-38 
    ISSN: 1432-1041
    Keywords: bezafibrate ; hyperlipoproteinemia ; bioavailability ; pharmacokinetics ; GC-MS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition kinetics of bezafibrate, a newly developed drug of great lipid-lowering potency, were investigated in normal male subjects. Five male volunteers received14C-labelled bezafibrate orally in solution, and a further 10 were given the same dose (300 mg) of un-labelled drug as tablets. The concentration of bezafibrate in serum and urine from the latter was determined by GC, and in the former total radioactivity in serum, urine and feces was followed for 48 h, and urinary excretion products were analysed by TLC and GC-MS. Rapid absorption from the gastrointestinal tract led to peak serum levels 30 min and 2 h after administration of solution and tablets, respectively. Since approximately 95% of the administered14C-bezafibrate was excreted in urine within 48 h, and almost all the remainder was detected in feces, absorption can be regarded as complete after administration in solution. The relative optimal bioavailability from the tablets was also complete, since in both cases approximately 50% of the administered dose was detected as unchanged bezafibrate in urine within 24 h by GC in the tablet study, and by TLC in the solution study. Of the decomposition products, more than 20% of the dose was present as glucuronides and the remainder consisted of several more polar compounds, one of which was identified as a hydroxyderivative of bezafibrate. Since the apparent halflife of bezafibrate in serum was 2.1 h, this new drug possesses favourable pharmacokinetic features: rapid and complete absorption, even from tablets, combined with a conveniently short half-life, and clearance which is half renal (56 ml/min) and half metabolic (43 ml/min), giving a total clearance of 99 ml/min.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    ISSN: 1432-1041
    Keywords: indobufen ; platelet aggregation ; single dose ; bioavailability ; pharmacodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six healthy volunteers received single iv and oral doses of 2-[p-(1-oxo-2-isoindolinyl)phenyl] butyric acid 100 mg (indobufen; K 3920), an inhibitor of platelet aggregation. Plasma levels and urinary excretion of the drug were determined by GLC. Collagen-induced platelet aggregation was assessed turbidimetrically at various intervals after administration. The plasma half-life of the drug was 7–8 h and more than 70% of the administered dose was recovered within 48 h in urine, as unchanged drug and as the glucuronide of indobufen. After oral administration of tablets of two different formulations, the drug was completely absorbed, but one formulation showed faster absorption. The maximal inhibitory effect on platelet aggregation was observed 1 to 4 h after iv administration, and it had decreased by 8 h. After tablets, peak effect and the time of the peak were similar, but activity was significantly prolonged, in accordance with the higher plasma levels found at 8 h. The data suggest that the effect of indobufen on platelets is reversible, and that for this drug platelets behave as a compartment that slowly equilibrates with plasma.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 433-441 
    ISSN: 1432-1041
    Keywords: cyclobarbital ; barbiturates ; pharmacokinetics ; drug interaction ; volunteers ; patients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disappearance of cyclobarbital from plasma has been followed in healthy volunteers and in neurological and psychiatric patients after oral administration of one tablet of Phanodorm®, containing cyclobarbital calcium 200 mg. Plasma levels were measured by a thin-layer chromatographic method with in situ densitometry. The average t1/2 in healthy female and male volunteers was 13.3 h, and with the assumption of complete availability a mean distribution coefficient of 0.69 l/kg−1 and a clearance of 40.4 ml/min−1 were calculated. Repeated experiments in seven volunteers revealed good reproducibility of all values. When the healthy volunteers were combined with a group of untreated epileptics, a dependence of t1/2 and of the apparent volume of distribution on age was found, while clearance did not change with increasing age (range 17–54 years). Long half-lives caused by low clearance values were observed in several individuals with moderate obesity. No consistent change in cyclobarbital kinetics followed acute exposure of volunteers to alcohol or on treatment of neurological patients with carbamazepine. Patients under treatment with perazine exhibited more or less normal kinetic values. In terms of drug interaction, cyclobarbital differs from phenazone in several respects, and so it may prove a useful additional substance for measurement of the rate of drug oxidation in humans.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 1-6 
    ISSN: 1432-1041
    Keywords: lorcainide ; ventricular premature beats ; plasma levels ; pharmacokinetics ; side effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma level and antiarrhythmic effect of lorcainide (R 15889) have been investigated in 15 patients with ventricular premature beats (VPB). Therapy was initiated with an intravenous dose of 1.9 mg/kg given over 10 min, followed by a constant infusion of 0.18 mg/kg/h for 24 h. In 8 patients the corresponding doses were increased to 2 mg/kg and 0.27 mg/kg/h. After the intravenous doses patients were treated orally with 100 mg tid for 6–7 days. The two dosage regimens were selected so as to achieve theoretical steady-state plasma levels (css) of 200 and 300 ng/ml, respectively. The combined intravenous treatment approached (181 ± 6.8 ng/ml and 273±28.5 ng/ml, respectively) the desired css within 2 to 4 h. During the oral administration, the minimal plasma concentrations following the lower intravenous dose (184±18 ng/ml) were significantly (p=0.0001) lower than after the higher intravenous dose (264±20.5 ng/ml). The dealkylated metabolite of lorcainide was not detectable after the intravenous doses, but it accumulated during oral treatment, when its concentration exceeded that of the parent compound. In 5 of the 7 patients receiving the lower dose VPB were effectively reduced. However, in only 4 of the 8 patients on the higher dosage schedule could a significant antiarrhythmic effect be demonstrated. In addition, side effects were observed in 6 of the subjects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 23-29 
    ISSN: 1432-1041
    Keywords: valproate ; epilepsy ; pharmacokinetics ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In four refractory epileptic patients, peak plasma levels of sodium valproate occurred within 1.5 to 3 h after a single oral dose of valproate and the decline in plasma levels followed a monoexponential course with a t1/2 of 11.4 ± 0.1 h. The mean value for apparent volume of distribution was 0.176 ± 0.013 l/kg and for total plasma clearance 0.0106 ± 0.0009 l/h/kg. Steady state plasma levels were predicted using the method of superposition utilizing pharmacokinetic parameters determined following a single dose of valproate and were 78–123% of the predicted values for two patients receiving valproate alone, and 37–64% of the predicted values for the two patients receiving carbamazepine in addition to valproate. In a further group of 20 patients the mean daily doses of valproate for 8 patients receiving valproate alone (25.4 ± 4.9 mg/kg) was significantly less than those for the 12 patients receiving concomitant anticonvulsant therapy (41.6 ± 12.3 mg/kg) (p〈0.005). In addition, the steady state predose plasma levels of valproate were significantly higher in the valproate alone patients (90.3 ± 8.7 µg/ml) compared to the patients receiving additional anticonvulsants (75.3 ± 13.8 µg/ml) (p〈0.01). The higher dose requirements of valproate and lower predose and steady state plasma levels for those patients on multiple anticonvulsants indicate an interaction between valproate and other anticonvulsants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 45-48 
    ISSN: 1432-1041
    Keywords: quinidine ; slow release formulation ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The bioavailability of quinidine in two sustained release preparations A and B has been compared in three females and three males with i.v. administration of quinidine. The initial rate of oral absorption did not differ between the two drug preparations; the peak concentration was observed after 4 h both for A and B, but was significantly higher after B. A slower decrease in plasma concentration was observed after preparation A than B. Absolute bioavailability did not differ significantly between A (median value 78.4%) and B (median 87.1%). Drug absorption in vivo was in good agreement with the results of in vitro dissolution tests on both preparations. The slower decrease in plasma concentration found for the new sustained release form of quinidine should be of clinical advantage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 49-52 
    ISSN: 1432-1041
    Keywords: cephacetrile ; haemodialysis ; pharmacokinetics ; renal failure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of cephacetrile were studied after its administration as a single i.v. bolus injection of 15 mg/kg body weight to 11 patients with terminal renal inpairment undergoing haemodialysis for 6 h. A two-compartment kinetic model was used to describe the biphasic decrease in plasma concentration. The quantities of antibiotic in the central and peripheral compartments, and the amounts eliminated, were calculated for different times. During haemodialysis sessions, the average pharmacokinetic parameters of cephacetrile determined at the dialyser input were: α=5.03 h−1,β=0.458 h−1, K12=2.337 h−1, K21=1.996 h−1 K13=1.154 h−1, Vc=5.508 l, Vp=6.448 l, Vdss=11.956 l. As a function of the pharmacokinetic parameters of cephacetrile, a regimen of multiple doses was established for patients with terminal renal impairment, which will guarantee safe and effective concentrations of the antibiotic.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1432-1041
    Keywords: methadone ; mass fragmentography ; pulse labeling ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A technique is presented for study of steady state kinetics of methadone using pulse labeling with deuterated methadone (d3) and mass fragmentography to measure both unlabeled and labeled methadone in blood. Seven subjects maintained on methadone for at least 10 months were admitted to a closed metabolic ward. The daily dose of unlabeled methadone (d0) was substituted by one dose of methadone-d3 and plasma levels of methadone-d0 and methadone-d3 were followed for 48 h using a precise (SD±5%) and sensitive (30 pmol/ml) mass fragmentographic technique. Plasma half-lives (t1/2) for both methadone-d0 and metadone-d3 were calculated from samples obtained 8–24 h following the dose of methadone-d3. The t1/2 of oral methadone-d3 was shorter (22±2 h) than that of methadone-d0 (52±20 h). The same pattern was observed after intravenous administration. The results indicate multiple pools of methadone in the body.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 177-181 
    ISSN: 1432-1041
    Keywords: prazosin ; alpha receptor blockade ; blood pressure ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and effects of prazosin have been studied after intravenous and oral dosing (1 mg) to 6 normal male volunteers. The mean terminal (β) half-life was 2.9 h after intravenous and oral routes. Oral bioavailability was 56.9%. The effects of prazosin on blood pressure were more pronounced after intravenous than oral administration, and the hypotensive effect greater on erect blood pressure. There was a significant correlation (P〈0.02) between the fall in blood pressure and the plasma drug concentration after intravenous prazosin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 189-194 
    ISSN: 1432-1041
    Keywords: sparteine ; pharmacogenetic defect ; defective metabolism ; pharmacokinetics ; renal excretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Sparteine is metabolized by N1-oxidation, which in some subjects is defective. The defect has a pronounced effect on the kinetics of the drug. In non-metabolisers elimination of sparteine proceeds entirely via renal excretion by a capacity-limited process, 99,9% of the dose being excreted as unchanged drug. In metabolisers the drug is mainly eliminated by metabolic degradation. Pronounced differences in β-phase half-life and total plasma clearance were observed between metabolisers (156 min; 535 ml · min−1) and nonmetabolisers (409 min; 180 ml · min−1).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 195-202 
    ISSN: 1432-1041
    Keywords: metformin ; biguanides ; pharmacokinetics ; absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The kinetics of14C-metformin have been studied in five healthy subjects after oral and intravenous administration. The intravenous dose was distributed to a small central compartment of 9.9±1.61 ( $$\bar X$$ ±SE), from which its elimination could be described using three-compartment open model. The elimination half-life from plasma was 1.7±0.1 h. Urinary excretion data revealed a quantitatively minor terminal elimination phase with a half-life of 8.9±0.7 h. After the intravenous dose, metformin was completely excreted unchanged in urine with a renal clearance of 454±47 ml/min. Metformin was not bound to plasma proteins. The concentration of metformin in saliva was considerably lower than in plasma and declined more slowly. The bioavailability of metformin tablets averaged 50–60%. The rate of absorption was slower than that of elimination, which resulted in a plasma concentration profile of “flip-flop” type for oral metformin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 327-330 
    ISSN: 1432-1041
    Keywords: atenolol ; food intake ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of food intake on the bioavailability of the beta-adrenoceptor blocker atenolol was assessed by measurement of its single-dose kinetics in ten healthy volunteers, who took 100 mg both in the fasting state and together with a standardized breakfast. Food intake significantly shortened the time to reach peak concentration (2.7 h vs 1.5 h), but caused a significant reduction in AUC values, the mean decrease being 20%. The elimination half-life was unaffected. Atenolol, which is relatively hydrophilic, is incompletely absorbed in the fasting state, and escapes first-pass metabolism. The present findings indicate that food intake causes further impairment of its absorption, even though the absorption rate may initially be enhanced. This contrasts with previous observations on the more lipophilic beta-adrenoceptor blockers propranolol and metoprolol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 331-334 
    ISSN: 1432-1041
    Keywords: netilmicin ; radioenzymatic assay ; drug accumulation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of a single dose of netilmicin (NM) was studied in 6 healthy volunteers. Elimination of the drug was followed in serum and urine for 24 h and 72 h, respectively. NM concentrations were measured with a modified radioenzymatic assay. A three compartment open model was employed to calculate the pharmacokinetic parameters. Following the rapid initial distribution, biphasic elimination with half lives of 1.99 h (t1/2β) and 36.89 h (t1/2γ) was demonstrated. Measurable amounts of NM were excreted in the urine for up to 72 h. The volume of distribution at steady-state (Vdss) of 0.68 l/kg was 3 to 4 times larger than previously reported for this antibiotic. NM plasma clearance was 91 ml/min and the renal clearance was 67 ml/min. The data indicate that on repetitive dosing the amount of drug in the body would be considerably underestimated if the prolonged terminal elimination phase were not taken into account. During prolonged treatment, accumulation of NM in renal and other tissues is likely to occur, as has been described for other aminoglycosides. The possible consequences of this pharmacokinetic behaviour are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 335-340 
    ISSN: 1432-1041
    Keywords: cimetidine ; enterohepatic circulation ; irregular absorption ; bioavailability ; pharmacokinetics ; volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The bioavailability and pharmacokinetics of cimetidine have been studied in healthy volunteers after administration of single intravenous (100 mg) and oral doses (100, 400 and 800 mg). After i.v. administration, the kinetics of cimetidine could be described by a linear, two compartment open model. Substantial variation in half-life was observed between subjects, with a mean value of 2.1 h (range 0.9–4.7). Cimetidine had a low hepatic extraction ratio and a high total plasma clearance, due to extensive urinary excretion of unchanged drug. After oral administration, the plasma concentration vs time curves in most subjects exhibited two marked peaks, an observation that seemed to be constant within individuals and was independent of dose. Bioavailability, estimated as the area under the plasma concentration vs time curves (AUC), after oral doses as compared to the intravenous dose, in most cases exceeded 100%. There was no correlation between bioavailability estimated as AUC and as urinary excretion of unchanged drug. These observations may indicate an enterohepatic circulatory mechanism, predominantly after oral administration. Both unchanged drug and its sulphoxide metabolite appear to be excreted in bile. The latter was shown in vitro to be reduced to cimetidine by fecal bacteria.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1432-1041
    Keywords: prenalterol ; metoprolol ; haemodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The haemodynamic effects of the selectiveβ 1-adrenoceptor agonist prenalterol were studied in healthy subjects before and after therapeutic doses of the selectiveβ 1-adrenoceptor blocker metoprolol. Plasma levels of the drugs were also determined in order to calculate certain pharmacokinetic variables. Intravenous infusion of prenalterol 0.13, 0.25 and 0.50 mg induced a dose-dependent decrease in total electromechanical systole (QA2) and pre-ejection period (PEP). The effect on left ventricular ejection time (LVET) was not significant. Increases in systolic blood pressure and heart rate were dose-dependent. Diastolic blood pressure did not change significantly. When metoprolol had been administered in a cumulative dose of 150 mg (mean maximal plasma level, 284 nmol/1) prenalterol had to be administered in doses that were twelve times higher than before theβ-blocker in order to induce the same haemodynamic effects. Prenalterol was rapidly distributed with an average half life of 8 min. This indicates that distribution equilibrium will be achieved within 30 min after intravenous administration. The overall elimination rate in the post-distributive phase corresponded to an average half life of 2.0 h.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 269-274 
    ISSN: 1432-1041
    Keywords: phenytoin ; food-intake ; bioavailability ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of food intake on the absorption of phenytoin was examined in eight healthy volunteers, by study of single-dose kinetics following ingestion of phenytoin 300 mg either with a standardized breakfast or on an empty stomach. Blood samples were collected at regular intervals from 0 to 48 h, and serum concentrations of unmetabolized phenytoin were determined by gas chromatography. Serum concentrations of the major metabolite of phenytoin, 4-hydroxyphenytoin, were measured by mass fragmentography. Concurrent intake of food and phenytoin appeared to accelerate absorption of the drug from the formulation used, and the peak concentrations were significantly higher (mean increase 40%) in the postprandial than in the preprandial state. As reflected by the AUC (area under the curve), the amount of drug absorbed was increased during postprandial conditions, although the difference only reached borderline significance. It is suggested that phenytoin should always be taken in a defined relation to meals.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 1432-1041
    Keywords: myasthenia gravis ; neostigmine ; gas chromatography-mass spectrometry ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To permit rational evaluation of the empirical pharmacotherapy of myasthenia with cholinesterase inhibitors, a sensitive and selective method for the determination of neostigmine has been developed. Analysis is based on ion-pair extraction of neostigmine into methylene chloride and determination by gas chromatography-mass spectrometry (chemical ionization). As neostigmine was found to be metabolized in plasma in vitro, deuterated (d6) neostigmine was immediately added to the plasma sample as the internal standard. The limit of quantitation of the method was about 1 ng/ml (∼ 3nmol/l). The kinetics following i. v. administration were studied in four patients, who received neostigmine 2.5–3.0 mg iv to antagonize pancurone administered during anaesthesia. Elimination was rapid with a half-life t1/2 (β-slope) of 0.89±0.05 h (mean ± SE). The volume of distribution was 1.08±0.11 l/kg and plasma clearance was 0.84±0.04 l/kg/h. In three fasting myasthenic patients plasma concentrations of neostigmine were followed for 5 h after a single oral dose of 30 mg. Considerable interindividual differences in absorption were expressed in the peak concentrations, which occurred 1–2 h following drug ingestion. The bioavailability of neostigmine was estimated to be 1–2% of the ingested dose. Neostigmine concentration in plasma was found to differ considerably (up to forty-fold) between myasthenic patients on their ordinary dose-schedules of cholinesterase inhibitors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 101-105 
    ISSN: 1432-1041
    Keywords: dihydroquinidine ; congestive heart failure ; intravenous administration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of dihydroquinidine were studied in 8 patients with congestive heart failure following a 22 min intravenous infusion of a quinidine preparation that contained 5.9% dihydroquinidine as an impurity. Using a thin layer chromatography-fluorometric assay procedure for dihydroquinidine, the post-infusion plasma dihydroquinidine concentrations declined biexponentially. The half-life of the fast and slow dispositional processes was 4.42±1.81 min and 6.52±2.40 h, respectively. The central compartment volume for dihydroquinidine in these patients was 0.44±0.11 l/kg with an overall apparent volume of distribution of 1.14±0.38 l/kg. The computed values of total body plasma clearance of dihydroquinidine ranged from 1.29 to 2.69 ml/min/kg with a mean value of 1.94±0.60 ml/min/kg. In these patients, approximately 16% of the administered dihydroquinidine dose was excreted intact into the urine in 48 h. The estimated value of renal clearance was 0.314±0.129 ml/min/kg. When compared to control cardiac patients, the data showed that the apparent volume of distribution for dihydroquinidine is smaller in patients with congestive heart failure and as a result of this diminished volume, the clearance rate of dihydroquinidine was slower. The net effect of these differences was the production of higher plasma concentrations of dihydroquinidine in the heart failure group.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 119-124 
    ISSN: 1432-1041
    Keywords: cefoxitin ; renal impairment ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of cefoxitin have been determined after a single i.v. injection of 15 mg/kg body weight in 10 patients with normal renal function and 20 patients with varying degrees of renal impairment. The kinetics of the antibiotic followed an open two-compartment model. In patients with normal renal function the following pharmacokinetic parameters were found: $$\begin{gathered} \begin{array}{*{20}c} {\alpha = 8.66 h^{ - 1} } & {\beta = 1.21 h^{ - 1} } & {K_{12} = 3.47 h^{ - 1} } \\ \end{array} \hfill \\ \begin{array}{*{20}c} {K_{21} = 3.17 h^{ - 1} } & {K_{13} = 3.15 h^{ - 1} } & {V_c = 4.24 l.} \\ \end{array} \hfill \\ \begin{array}{*{20}c} {V_p = 4.87 l.} & { Vd_{ss} = 9.11 l.} \\ \end{array} \hfill \\ \end{gathered}$$ In the patients with renal impairment there was a significant decrease in $$\mathop \alpha \limits_, \mathop \beta \limits_, $$ K12, K21 and K13, and an increase in the apparent volume of distribution. The degree of plasma protein binding in patients with normal renal function was 73.6% and this was diminished in patients with renal impairment. A linear relationship between K13 of cefoxitin and creatinine clearance was demonstrated. The dosage regimen for patients with renal impairment should be adjusted by modifying the dosage interval whilst maintaining the amount administered.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 133-139 
    ISSN: 1432-1041
    Keywords: theophylline ; asthma ; pharmacokinetics ; children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six children, aged 2 months – 4 years, received theophylline 5–6 mg/kg intravenously. Its disposition could be described by a two-compartment open model, the mean serum half life (t1/2 β) was 3.75 h, i. e., shorter than in adults, but there was a considerable interindividual variation (1.8–7.0 h, in one patient 13.3 h). Thirteen children (2 months – 4 years) received theophylline suppositories in a dose of 3.8–5.0 mg/kg, and ten (6 months – 4 years) in a dose of 8.4–14.5 mg/kg. Absorption was slow (mean half-time 43 min), incomplete and variable (biological availability 8–100%, mean 80%). Only four of the patients given the higher dose and none given the lower dose reached a therapeutic serum concentration (10–20 µg/ml). Nine children (6 months – 4 years) received rectal enemas of theophylline 4.1–9.2 mg/kg. Absorbtion was rapid (mean half-time 5.5 min) and biological availability averaged 100%. Six patients reached a serum concentration within the therapeutic range. Using the mean values of the calculated pharmacokinetic parameters, rectal enemas providing a dose of theophylline of 6–8 mg/kg t. i. d. were computed to give serum concentrations between 8–20 µg/ml, without producing too high a level during the absorption phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 279-285 
    ISSN: 1432-1041
    Keywords: salicylate ; synovitis ; osteoarthritis ; arthritis ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Samples of blood and joint fluid from 30 patients who had taken buffered acetylsalicylic acid were examined for concentrations of total salicylates (TSA), acetylsalicylate (ASA) and salicylate (SA). The data were arranged in groups according to diagnosis of the joint disease. Analysis of the data did not show significant difference in the kinetics of TSA into blood. In groups the time to first appearance of 0.3 mg/l averaged 6.3 min for TSA; these values averaged 7.7 min for ASA and 10.9 min for SA. Close to maximum concentrations in blood averaged 18.9 mg/l for TSA, 3.3 mg/l for ASA, and 23.3 mg/l for SA. The time for first appearance of 0.3 mg/l of total salicylates in joint fluid ranged from 10 to 34 min with an average of 18.1 min; the values of ASA averaged 19.4 min and those of SA 21.9 min. The maximum concentration in joint fluid averaged 15.7 mg/l for TSA, 2.5 mg/l for ASA, and 14.5 mg/l for SA. Transport of salicylates from blood to joint fluid showed a pattern consistent with the type of joint disease. Support was found for the hypothesis that diffusion was the major factor in the movement of salicylates from blood to joint fluid.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 16 (1979), S. 411-416 
    ISSN: 1432-1041
    Keywords: doxapram ; intravenous infusion regimen ; pharmacokinetics ; data-point weighting ; healthy subjects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of intravenous doxapram in healthy individuals is consistent with a three-compartment open model. Doxapram was administered by bolus injection (1.5 mg · kg−1) and by intravenous infusion (6.5 mg · kg−1 for 2 h) to 5 subjects on separate occasions. There was no significant difference in mean terminal plasma half-lives (355 and 448 min) or in mean total body clearances (5.9 and 5.6 ml · min−1 · kg−1) following i. v. bolus injection or infusion respectively. In 3 subjects plasma doxapram concentrations during and after i. v. infusion agreed with those predicted from pharmacokinetic values obtained from the bolus injection study. Since mean steady-state concentrations (9.9 µg · ml−1) would be reached only after an extended interval (mean 15.2 h), a variable-rate infusion regimen was calculated to produce and maintain a concentration of 2 µg · ml−1 from 15–25 min onwards. A regimen in which the infusion rate is reduced step-wise is recommended to achieve early near-constant plasma doxapram concentrations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 105-108 
    ISSN: 1432-1041
    Keywords: muzolimine ; cardiac failure ; pharmacokinetics ; high ceiling diuretics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of a new “high ceiling” diuretic, muzolimine (Bay g 2821), were investigated after a single oral dose of 40 mg in 7 patients with cardiac failure (Stages I–IV, New York Heart Association classification), and in 2 healthy subjects. Plasma concentrations peaked 1–3 h after administration and declined according to a two-compartment model. The α-phase (distribution phase) lasted until 12–16 h after administration and the mean t1/2α was 3.6 h (range 2.3–4.7) in patients, and 2.6 h (range 2.3–2.9) in healthy subjects. The mean t1/2β was 13.5 h (range 7.4–22.4) in the patients and 14.0 h (range 12.4–14.6) in healthy subjects. T1/2β was not correlated with the degree of heart failure or with the area beneath the plasma concentration curve, which varied three-fold. The renal clearance of muzolimine was in the range 2.7–15.3 ml · min−1 in 5 subjects in whom it was investigated. The pharmacokinetics of muzolimine appear not to be significantly altered by cardiac failure. The prolonged half-lives of the drug are probably responsible for the longer duration of diuretic action reported for muzolimine than for furosemide and bumetamide.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 15 (1979), S. 115-120 
    ISSN: 1432-1041
    Keywords: digoxin ; right heart failure ; absorption ; absolute bioavailability ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The absorption of digoxin has been investigated in 8 patients before and after successful treatment of severe right heart failure.3H-digoxin 0.1 mg as a solution, and un-labelled digoxin 0.25 mg as a tablet, were given to fasted patients. Blood samples were taken at various time intervals up to 120 hours and urine was collected over the same period. The concentrations of labelled digoxin in plasma and urine were measured in a liquid scintillation counter, unlabelled digoxin was estimated by radioimmunoassay, and various pharmacokinetic parameters were calculated. There was no significant difference in the plasma concentration curves in severe right heart failure and after its successful treatment, nor did any of the calculated pharmacokinetic parameters change significantly. Therefore, inhibition of the absorption of digoxin appears unlikely. In an additional study to estimate absolute bioavailability two different groups of patients in severe right heart failure were given3H-digoxin 0.1 mg or unlabelled digoxin 0.25 mg i. v. and the pharmacokinetic parameters were compared with those from the previous study. The bioavailability of the3H-digoxin solution and of the digoxin tablet were in the same range as values previously published for healthy volunteers, and patients both with and without cardiac failure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1432-1041
    Keywords: metoprolol ; tachycardia ; healthy subjects ; conventional tablets ; slow release tablets ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma levels and associated reduction in exercise-induced tachycardia have been examined following the administration of single doses of metoprolol in conventional and slow-release tablets at different times to six healthy male subjects. The study was carried out in two parts. Initially, the tablets were given at 9 a. m. and the subjects were studied up to 14 h and then at 24 h. Subsequently, the same doses were given at 9 p. m. and the subjects were studied 12–24 h after drug administration (i. e. 9 a. m.–9 p. m. the next day). After giving the slow-release tablets the peak plasma levels were significantly lower but the drug persisted in the plasma at higher levels than after the conventional tablet. However, the beta-blocking effect was comparable from the two dosages. The results obtained for the period 12–24 h after the evening dose differed from the corresponding values after morning administration in that the plasma levels were higher and the betablocking effects more marked. Furthermore, the half-life values calculated from these data were significantly longer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1432-1041
    Keywords: triamterene ; pharmacokinetics ; diuretic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma and urinary levels of triamterene and two metabolites were measured using a specific method of analysis. Urinary excretion was completed after 48 h, which permitted a rough estimate of its half-life as longer than two hours. The areas under the curve were 672.5±160.3 and 1.311.3±399.1 µg/ml × h after the triameterene 150 mg and 300 mg p.o., respectively and correspondingly 4.2±1.4% and 3.7±0.6% of the dose were excreted as unchanged drug. The principal metabolite of triamterene found was the sulfate conjugate. The area under the curve of this metabolite amounted to 6.672±2.120 and 11.941±5.005 µg/ml × h after the of 150 mg and 300 mg triamterene doses, respectively. The urinary excretion of the metabolite varied between 25.0±4.0% and 17.5±3.5% of the dose after either dose. In healthy subjects an effect on sodium excretion was observed after a dose of 150 mg, whereas the potassium-retaining effect was observed only after the dose of 300 mg.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 287-287 
    ISSN: 1618-2650
    Keywords: Nachw. von Carbamatpesticiden in biolog. Material ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 361-365 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Informationsgehalt und »Äquivokation«
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A method has been developed for the calculation of information contents of one-channel identification procedures, which is especially applicable in the area of thin-layer chromatography (TLC). The method can be considered as a refinement of the one proposed by Massart and can easily be extended to the combination of one-channel procedures. In addition, the quantity ‘equivocation’, which is complementary to the information content, is introduced. As an example the best TLC-systems and the best combinations of two TLC-systems for the identification of DDT and twelve related compounds are selected by using information contents or equivocations. The results for the individual systems are compared with those obtained by Massart.
    Notes: Zusammenfassung Eine Methode zur Berechnung von Informationsgehalten von Einkanal-Identifizierungsverfahren wurde entwickelt, die besonders gut für das Gebiet der Dünnschicht-Chromatographie (DC) anwendbar ist. Sie kann als eine Verfeinerung der von Massart vorgeschlagenen Methode angesehen werden und kann auf einfache Weise für Kombinationen von Einkanal-Verfahren erweitert werden. Dabei wird der Begriff »Äquivokation«, komplementär zum Informationsgehalt, eingeführt. Als Beispiel wurden die besten DC-Systeme und Kombinationen von zwei DC-Systemen für die Identifizierung von DDT und zwölf verwandten Verbindungen unter Benutzung von Informationsgehalten oder »Äquivokationen« ausgewählt. Die Ergebnisse für die einzelnen Systeme werden mit den nach Massart gefundenen verglichen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 407-407 
    ISSN: 1618-2650
    Keywords: Trenn. von Arylbenzolsulfonylthiocarbamiden ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 398-401 
    ISSN: 1618-2650
    Keywords: Analyse von pharmazeut. Produkten ; Chromatographie, Dünnschicht ; halogenfreie Fließmittelsysteme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Mit 2 sauren, 2 basischen und einem neutralen Fließmittel mit unterschiedlichen Polaritäten und guten Trennleistungen konnten 151 von 157 geprüften Arzneisubstanzen mit hRf-Werten zwischen 10 und 90 chromatographiert werden.
    Notes: Summary Using two acidic, two alkaline and a neutral mobile phase of different polarities and high separation efficiencies 151 of 157 tested drug substances could be chromatographed with hRf-values between 10 and 90.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 24-29 
    ISSN: 1618-2650
    Keywords: Best. von Polycyclen in Wasser ; Chromatographie, Dünnschicht ; Änderung der Fluorescenzintensität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Nach der Verordnung über Trinkwasser und Brauchwasser für Lebensmittelbetriebe (Trinkwasserverordnung) vom 31. Januar 1975 müssen 6 Einzelverbindungen aus der Gruppe der polycyclischen aromatischen Kohlenwasserstoffe nachgewiesen werden. Das empfohlene Analysenverfahren basiert auf der Messung der Fluorescenz nach vorangegangener chromatographischer Trennung auf Adsorberschichten. Sowohl bei dieser Trennung als auch in der anschließenden Zeit verändert sich die Fluorescenzintensität einzelner Verbindungen z.T. beträchtlich. Systematische Untersuchungen an Kieselgel und an Mischschichten aus Aluminiumoxid und Acetylcellulose sollen die kritischen Punkte und die möglichen Fehlerquoten offen legen.
    Notes: Summary According to the regulation on the use of drinking and industrial water in food industry (Drinking Water Regulation) of 31 January, 1975, six individual compounds of the group of polycyclic aromatic hydrocarbons must be traced. The analytical procedure recommended is based on the measurement of fluorescence after preceding Chromatographic separation on adsorber layers. In the course of this separation and during the time that follows, the fluorescence intensity of various compounds changes, in some cases considerably. Systematic studies with silica gel and mixed layers of aluminium oxide and acetyl cellulose are intended to reveal critical points and possible ranges of error.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 138-143 
    ISSN: 1618-2650
    Keywords: Trenn, der Metallchelate von 8-Mercaptochinolin ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 8-Mercaptochinolin (Thiooxin) eignet sich zum Nachweis und zur Trennung von Metallen mit Hilfe der Dünnschicht-Chromatographie. Es bildet Neutralkomplexe definierter Zusammensetzung, die in wäßriger Phase schwerlöslich sind und in Chloroform extrahiert werden können. Fällung und Extraktion sind vom pH-Wert abhängig, wodurch eine Vortrennung der Metalle möglich ist. Beschrieben wird das dünnschicht-chromatographische Verhalten von 17 Metallchelaten. Die intensive Eigenfärbung der Komplexe erübrigt den Gebrauch von Anfärbereagentien. Die visuelle Nachweisgrenze der Metalle liegt zwischen 5 und 20 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um etwa eine Zehnerpotenz erwarten.
    Notes: Summary 8-Mercaptoquinoline (thiooxine) is qualified for the detection and separation of metals by thin-layer chromatography. It forms neutral complexes in definite composition, which are insoluble in aqueous solution, but readily soluble in CHCl3. Precipitation and extraction are dependent on the pH value, whereby pre-separation of metals is possible. The thin-layer chromatographic behaviour of 17 metal chelates is described. No spraying is necessary for detection, since the complexes show different, characteristic colours. The visual detection limits of the metals are between 5 and 20 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 144-147 
    ISSN: 1618-2650
    Keywords: Trenn. der Metallchelate von 1-Hydroxy-2-pyridinthion ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1-Hydroxy-2-pyridinthion (HPT) bildet mit den Metallen der 8. Nebengruppe des Periodensystems intensiv gefärbte Chelatkomplexe. Führt man die Reaktion in wäßriger Phase bei pH 7 aus, so werden alle Elemente der Gruppe erfaßt und als schwerlösliche Neutralkomplexe gefällt. Diese lassen sich mit Chloroform extrahieren und dünnschichtchromatographisch trennen. Die Nachweisgrenze der Metalle liegt zwischen 3 und 40 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um eine Zehnerpotenz erwarten.
    Notes: Summary 1-Hydroxy-2-pyridinethione (HPT) forms highly coloured chelate complexes with the metals of the 8th sub-group. If the reaction is carried out in aqueous solution at pH 7, all elements of the group precipitate as insoluble neutral complexes. They can be extracted with CHCl3 and separated by thin-layer chromatography. The detection limit is between 3 and 40 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 44-44 
    ISSN: 1618-2650
    Keywords: Trenn. von Guanylpyrazolnitraten ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 200 (1979), S. 409-423 
    ISSN: 1432-0878
    Keywords: Human placenta ; Classification of villi ; Histology ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The classification of human placental villi was reviewed on the basis of material prepared by means of special methods. The material from in situ normal-term placentae was biopsied by aspiration into glutaraldehyde. The classification was made on the basis of light-microscopic observations of semithin sections, reconstructions from serial sections, and scanning-electron micrographs. The peripheral villous tree is roughly divided into stem (ramuli), intermediate and terminal villi. The intermediate villi may be further subdivided as mature and immature types, which are found between the stem and terminal villi. Some of the terminal villi possess a local specialization described as the neck region. The histological characteristics and the branching pattern of each type are described, and the basis of the proposed classification is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 204 (1979), S. 147-153 
    ISSN: 1432-0878
    Keywords: Granulocytes ; Lymphocytes ; Monocytes ; Scanning electron microscopy ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Polymorphonuclear leukocytes, e.g., neutrophilic granulocytes, were enriched from heparinized blood by a Ficoll-step-gradient centrifugation procedure. Scanning electron microscopy (SEM) revealed a surface morphology of narrow ridge-like profiles and small ruffles with occasional microprocesses. Mononuclear leukocytes were isolated by centrifugation over a Ficoll-Metrizoat gradient. The lymphocytes showed varying numbers of microvilli of different length, size and shape. B lymphocytes, characterized by their capability of “sheep red blood cell (SRBC)-rosette formation”, displayed a similar surface morphology. Completely smooth lymphocytes, described in the literature as T lymphocytes, could not be detected, although many lymphocytes with few microprocesses were observed. Thus, SEM is not a useful tool for distinguishing between B and T lymphocytes in the peripheral blood of chickens. Monocytes were characterized by prominent membrane-like ruffles, but in some cases they closely resembled granulocytes. An influence of the various separation media on the surface morphology of the isolated cells could not be detected when compared with cells isolated by the buffy-coat method.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 199 (1979), S. 349-352 
    ISSN: 1432-0878
    Keywords: Spermatozoa ; Mitochondria ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary As seen by scanning electron microscopy, the mitochondrial helix in the developing midpiece of mouse testicular spermatozoa is dextral in direction and consists of spherical mitochondrial units arranged in an orderly array of four units per gyre: three appearing in face view and a fourth hidden from view at the back of the gyre. As the spermatozoa mature, the dextral helix is transformed into a sinistral helix. Its constituent spherical mitochondria either change direction abruptly without changing shape; or having first become semilunar or diamond-shaped, they change direction gradually. Mitochondrial division follows the change in helical pitch producing a double sinistral helix. The spherical (or semilunar/diamond-shaped) mitochondria presumably elongate to form the units of the mature midpiece.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 201 (1979), S. 129-135 
    ISSN: 1432-0878
    Keywords: Pineal body ; Freeze-fracturing ; Scanning electron microscopy ; Wistar rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional ultrastructure of the pineal body of the rat is described on the basis of freeze-fractured preparations. The pineal capsule consists of irregular cells with very flat and perforated processes. Through these openings, extremely branched canaliculi, extending to almost every pineal cell, communicate with the tissue compartment outside the organ. The pericapillary spaces contain, in juxtaposition with capillaries of the fenestrated type, nerve fibers as well as a flocculent granular and filamentous material of unknown origin and chemical nature.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 203 (1979), S. 53-64 
    ISSN: 1432-0878
    Keywords: Brain ; Third ventricle ; Rana temporaria ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface specializations of the wall of the third cerebral ventricle of Rana temporaria were investigated with the scanning electron microscope. These specializations can be divided into three types: cilia, large bulbous protrusions, and microvillus-like protrusions. Most parts of the ventricular surface are densely ciliated. In contrast, other regions are either scantily ciliated or devoid of cilia. Four areas of the ventricular surface are studded with numerous large bulbous protrusions. These large protrusions can be divided into two types: One type consists of intraventricular end bulbs of dendrites of secretory neurons. The other type is represented by large cytoplasmic extensions of ependymal cells. In the third ventricle of Rana, microvillus-like surface specializations of ependymal cells are ubiquitous structures. Generally, filiform protrusions of varying length are the predominant type. The microvillus-like specializations are transient structures, the number of which varies according to different physiological states of the ependymal cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 45-45 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Diphenylamin als Detektionsmittel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 369-373 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; vollautomat. Auswertung von Chromatogrammen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es werden vollautomatische DC-Photometer beschrieben, bei denen ein Rechner die optimale Positionierung der DC-Flecke im Meßspalt steuert. Es lassen sich nicht nur die normalen Meßkurven, sondern auch die gemäß der Kubelka-Munk-Funktion transformierten Kurven für die Auswertung heranziehen. Infolge der Steuerung des Wellenlängenantriebes lassen sich auch Zweiwellenlängentechniken simulieren. Für die Auswertung eignet sich auch die 1. Ableitung der Meßkurve. Die Genauigkeit und Reproduzierbarkeit wird gesondert nach Auftragefehler, Meßfehler, Positionierfehler und Fehler der Chromatographie ausgewiesen.
    Notes: Summary Automated photometers for evaluating TLC plates by an optimized positioning of the spots in respect to the centre of the light beam are described. The evaluation can be performed by using the original measuring curve or a transformed one in respect to the Kubelka-Munk function. Two-wavelength techniques can be simulated, for the monochromator is controlled by the computer. This method has an advantage in measuring not well separated spots. In this case also an evaluation of the first derivative is often successful. The accuracy and reproducibility is given in respect to the different sources of errors: spotting, measurement, positioning and chromatography.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    ISSN: 1573-8744
    Keywords: lorazepam ; benzodiazepines ; pharmacokinetics ; drug accumulation ; antipyrine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Six healthy volunteers participated in single- and multiple-dose pharmacokinetic studies of oral lorazepam. Following single 4-mg oral doses, peak plasma lorazepam concentrations ranging from 40 to 70 ng/ml were reached within 3 hr of the dose. Values of absorption half-life averaged 25min (range 10.3–42.7min), and elimination half-life (t 1/2β ) averaged 14.2 hr (range 8.4–23.9 hr). During 15 consecutive days of 3 mg per day administered in divided doses, accumulation to the steady-state condition was complete within several days of the initiation of therapy. Values of accumulation half-life (mean 21.1 hr) were slightly longer than t 1/2β , and the two were not well correlated. Observed accumulation ratios (mean 1.88) were very close to those predicted from the single-dose study (mean 1.77), but the correlation between the two (r=0.51) was not significant in the small sample size. “Washout” half-life values (mean 14.9 hr) were highly correlated with t 1/2β (r=0.92). Clearance of a single intravenous dose of antipyrine determined prior to the multiple- dose lorazepam study (mean 0.86 ml/min/kg) was essentially identical to that determined after the study (mean 0.87 ml/min/kg). Overall, the rate and extent of lorazepam accumulation during multiple dosage were reasonably well predicted by the single-dose kinetic study. However, accurate prediction for any specific individual was not always achieved. Stimulation or inhibition by lorazepam of its own clearance probably does not explain imprecise prediction, since single-dose t 1/2β .
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    ISSN: 1573-8744
    Keywords: procainamide ; pharmacokinetics ; constant-rate infusion ; acetylator phenotype ; pharmacogenetics ; renal impairment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of procainamide was determined in 21 lidocaine-resistant patients who received the drug according to a pharmacokinetically designed double-infusion technique. Thirteen patients were phenotyped as slow acetylators, seven as fast, and one as intermediate. The total body clearances (ClT) of PA in slow and fast acetylators were 22.6 and 34.8 liters/hr, respectively. The fraction of PA cleared by the formation of NAPA in the corresponding acetylator group was 0.2 and 0.4. Renal impairment affected the pharmacokinetics of PA more profoundly as the ClTs of PA in patients with and without renal impairment were 17.9 and 31.2 liters/hr, respectively. None of the calculated volumes of distribution was affected by acetylator phenotype or renal impairment. These data identify the contribution of at least two of the major factors accounting for variability in PA disposition in patients undergoing therapy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 249-264 
    ISSN: 1573-8744
    Keywords: dexamethasone ; pharmacokinetics ; renal excretion ; high-performance liquid chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of dexamethasone alcohol is described in six male and six female healthy adult volunteers who each received 8 mg of dexamethasone phosphate by bolus intravenous injection. Quantitation of the alcohol was done using a high-performance liquid Chromatographic method with improved specificity. Statistical evaluation of the results generated by nonlinear least-squares regression analysis of the plasma concentration-time data shows that the phosphate ester is very rapidly hydrolyzed to the alcohol and a biexponential equation is the simplest poly exponential equation that is consistent with the data. The terminal phase half-lifet 1/2β was significantly greater (p〈0.05) in males (mean 201.5 min) than in females (mean 142.3 min). The prolongedt 1/2β in males did not appear to be caused by an impaired capacity to eliminate dexamethasone since the total plasma clearance did not differ between males (mean 247.5ml/min) and females (mean 242.9 ml/min). There was, however, a high positive correlation betweent 1/2β and $$V_{d_{ss} } $$ among the 12 adults (r=0.92, p〈0.001). There were also significant correlations between $$V_{d_{ss} } $$ and body weight (r=0.67, p〈0.05) andt 1/2β (r=0.80, p〈0.01).The difference in body weight between the sexes seems to be the main factor contributing to the difference observed in t 1/2β. An average of only 2.6% of the dose was found unchanged in a 24-hr urine sample, and hence it appears that dexamethasone is primarily eliminated by extrarenal, probably hepatic, mechanisms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 383-396 
    ISSN: 1573-8744
    Keywords: chlorpheniramine ; pharmacokinetics ; oral absorption ; first-pass effect ; saturation kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of chlorpheniramine has been studied in six dogs by following the time course of plasma concentration of the drug after intravenous and oral administration of its maleate salt in solution form. After intravenous dosing the decline in chlorpheniramine plasma concentration was typically biexponential. The drug distributed rapidly and extensively to the extravascular tissues. The mean distribution phase halflife was 12.5 min, and the mean apparent volume of distribution, Vdβ, was 525% ofthe body weight in four dogs with normal hematocrits. The mean half-life of elimination was 1.7hr. The percent absolute availability following oral administration of the drug in the aqueous solution form was found to be dose dependent. At 100-mg dose, in six dogs, an average of 36% of the orally administered dose was found to be systemically available. At 50-mg dose, in one of the four dogs studied, no measurable plasma levels of chlorpheniramine were obtained, and the average bioavailability was only 9.4%. The average availability in four dogs at 200-mg dose was 39.4%. Even at 200-mg oral dose, the dogs did not show any signs of sedation and remained alert all through the experiment. Saturable first-pass gut and/or hepatic elimination has been postulated. The possible implications of these findings on the therapeutic effectiveness of the usual dosing regimen of chlorpheniramine in dogs are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 481-494 
    ISSN: 1573-8744
    Keywords: clonidine ; pharmacokinetics ; blood and brain levels ; liver clearance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract To investigate the pharmacokinetic behavior of clonidine, rats were given clonidine intravenously at 125, 250, and 500μg/kg and blood clonidine concentrations were followed for 6 hr. The disposition of clonidine in two brain regions was studied in rats after an i. v. dose of 500 μg/kg. The liver clearance in rats was investigated by liver perfusion techniques. The results obtained indicate that the disposition characteristics of clonidine can be described by a two-compartment open model in both rats and cats. The penetration of clonidine into tissues is rapid, and brain levels in rats were about 1.7 times higher than blood levels. Brain tissues were found to be an indistinguisible part of the central (blood) compartment. Dose-dependent pharmacokinetic behavior was found for clonidine in rats at the doses used. This was demonstrated by a decrease of both the rate constant of distribution to the peripheral compartment and the overall elimination rate constant from the body, with increase in dose. As a consequence, the volume of distribution and the clearance both decreased with increasing dose. Possible explanations for the dose-dependent behavior of clonidine are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 527-536 
    ISSN: 1573-8744
    Keywords: instantaneous distribution ; pharmacokinetics ; pulmonary first-pass effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The classical concept of assuming that an i.v. dose instantaneously distributes into the central or plasma compartment is reviewed, as is the potential for pulmonary first-pass effect. Based on available literature, the concept is shown to lead to serious errors in estimating pharmacokinetic parameters, particularly for drugs with high clearance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1573-8744
    Keywords: clonidine ; pharmacokinetics ; analgesia ; blood pressure effects ; smooth muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The time course of an observed pharmacological effect is affected not only by the kinetics of the drug levels at the site of action but also by parameters such as the slope and maximum effect of the functional relationship between drug level and response. Using clonidine as a test drug, it was found that the kinetics of its effects on blood pressure and pain responses cannot be described by the time course of clonidine levels in the blood, brain, or the hypothetical tissue compartment of the two-compartment characteristics of this drug. However, the results can be explained assuming that the observed pharmacological effects of a drug are composed of the sum of responses from at least two receptor sites with different slopes and maximal effects. The effect of intravenously administered clonidine on blood pressure in the rat was found to be related to the blood concentrations at least at two receptor sites with opposite effects, one leading to a hypertensive and the other to a hypotensive response. Predictions indicate that a maximum decrease of arterial blood pressure is obtained when the steady-state blood concentration of clonidine is about 1 ng/ml and that no effect is seen at 10 ng/ml. Higher levels will produce an increase of the pressure. The kinetics of the analgesic effect of clonidine in the rat could best be related to the brain levels if the observed effect was considered to be derived from the sum of activity at two receptor sites each producing analgesia. The kinetics of the effects of clonidine on the nictitating membrane of the cat was found to be determined by the kinetics of the drug in the peripheral compartment of the two-compartment open model. Consideration of multiple receptor responses is suggested for future studies on the relationship between the kinetics of drug levels and pharmacological responses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    ISSN: 1573-8744
    Keywords: digoxin ; pharmacokinetics ; response kinetics ; three-compartment model ; serum digoxin kinetics ; systolic time intervals ; radioimmunoassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A study designed to investigate the relationship between the pharmacokinetics of digoxin and a measure of its pharmacological effect has been conducted. Serum digoxin concentrations and systolic time intervals were measured concurrently in 12 normal male volunteers following a 1.0 mg i.v. bolus injection. The averaged serum digoxin concentration- time and response-time data were analyzed pharmacokinetically using a three-compartment open model and nonlinear least- squares fitting. When only the serum level-time data were analyzed, a close relationship was found between calculated digoxin levels in the slowly distributing (deep) peripheral compartment and response of the heart to digoxin, as measured by changes in the QS2 index δQS2I. Although it was not possible to distinguish clearly a linear from a nonlinear relationship between digoxin levels in the deep compartment and δQS2I, the nonlinear relationship gave the best overall fit when both serum digoxin and δQS2I data were fitted simultaneously. The simultaneous fityielded a total body clearance of digoxin of 3.6 ml/min/kg and a terminal t1/2 of 42 hr.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 87-95 
    ISSN: 1573-8744
    Keywords: clonazepam ; in vivo biotransformation ; 7-amino metabolite ; pharmacokinetics ; monkeys ; anticonvulsants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetic behavior of the 7-amino metabolite of clonazepam administered exogenously and formed endogenously from the parent drug was studied in a group of rhesus monkeys using constant rate intravenous infusions. Plasma levels of the 7-amino metabolite and/or clonazepam were determined with a GC-CI-MS method. The biological half-life of the 7-amino metabolite (2.2 ± 1.0 hr) was shorter than that of clonazepam (4.9 ± 0.2 hr). Total body clearance of the metabolite (0.83 ± 0.16 liters/hr/kg) was larger than that of the parent drug (0.55 ± 0.09 liters/hr/kg). The kinetics of in vivo biotransformation were described by a two- compartment model in which formation and disposition of the metabolite follow first-order processes. The fraction of a dose of clonazepam appearing in the systemic circulation as 7-amino metabolite was 0.70 ± 0.30. This value may underestimate the actual fraction formed, if the metabolite is susceptible to first- pass metabolism following in situ formation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 265-274 
    ISSN: 1573-8744
    Keywords: furosemide ; indomethacin ; prostaglandin ; pharmacokinetics ; pharma-codynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics and pharmacodynamics of intravenous furosemide, 40 mg, were studied in four normal males in a crossover fashion with and without indomethacin pretreatment. In each study 16 plasma and 10 urine samples were collected over 24 hr. Fluid and electrolyte urinary losses were replaced orally throughout the study. Unchanged furosemide and indomethacin were measured using HPLC; urinary sodium was measured by flame photometry. Pretreatment with indomethacin resulted in increased and prolonged furosemide plasma levels, increased area under the curve, decreased plasma clearance, decreased renal clearance, increased half-life, no change in volume of distribution, and decreased sodium excretion and urine volume. Analysis of sodium excretion rate with time shows that the inhibiting effect of indomethacin was greater during the first 2 hr than at later times.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 453-462 
    ISSN: 1573-8744
    Keywords: pheneturide ; antiepileptics ; pharmacokinetics ; TLC-UV densitometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of pheneturide (a decarboxylation product of phenobarbital), used to prevent psychomotor seizures for many years, was studied in normal human volunteers. To measure the drug in plasma and urine, a highly sensitive and reproducible thin-layer chromatography-reflectance spectrophotometric assay was developed. The results show that pheneturide follows first-order kinetics in the dose range studied. Its half-life after single doses is 54 hr (range 31–90), and its total body clearance (100% nonrenal) is 2.6 liters/hr (range 1.73–3.59). After repetitive administration, half-life is 40 hr (but clearance remains unchanged because of a lower volume of distribution). Because of the long half-life, repetitive administration results in a continuous steady-state level and makes this drug (kinetically) ideal for long-term use.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 7 (1979), S. 471-479 
    ISSN: 1573-8744
    Keywords: metoprolol ; α-OH-metoprolol ; active metabolites ; pharmacokinetics ; β- blocking effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The plasma levels and the β- blocking effect of metoprolol and its active metabolite α- hydroxymetoprolol have been studied after i.v. bolus injections of the substances to dogs. For both substances the β- blockade increased with the dose, and there was a linear relationship between percent reduction in exercise heart rate and the logarithm of plasma concentration. The dose of the metabolite, however, had to be 5 times higher than that of metoprolol to induce the same degree of β- blockade. Because of differences in the volume of distribution, 2.0 liters/kg for α- OH-metoprolol and 3.5 liters/kg for metoprolol, the 5 times higher dose of α- OH-metoprolol resulted in 10 times higher plasma levels of the metabolite than of metoprolol. α- OH-Metoprolol was more slowly eliminated (t1/2∼7.0 hr, total body clearance ∼3.5 ml-kg−1-min−1) than metoprolol (t1/2∼2.0 hr, total body clearance ∼20.0 ml-kg−1-min−1). Approximately 5% of an i.v. dose of metoprolol was metabolized to α- OH-metoprolol. The half-life of the endogenously formed metabolite was the same as after an i.v. dose of the compound.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 197 (1979), S. 169-173 
    ISSN: 1432-0878
    Keywords: Fourth ventricle ; Ependyma ; Scanning electron microscopy ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface features of the ependymal linings of the fourth ventricle in the fowl were analyzed employing the scanning electron microscope (SEM). On the floor of the median sulcus, each ependymal cell has a solitary cilium, whereas on both sides of the sulcus, cilia are so densely distributed that the details of the underlying cell surface are usually obscured. On the roof of the fourth ventricle, except for the surface of the ciliated groove where numerous cilia are present, the ependymal cells are polygonal in shape, and the center of each cell possesses an aggregate of ten to twenty cilia. Cell surfaces of the choroid tela are entirely covered with delicate microvilli and possess clumped cilia. The ependymal cell surfaces of the area postrema are dome-like in shape. Each ependymal cell has a solitary cilium and shows a smooth surface free of microvilli.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 203 (1979), S. 283-289 
    ISSN: 1432-0878
    Keywords: Radula ; Tooth formation ; Pulmonates ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The radular teeth are secreted at the posterior end of the radular gland and move slowly towards the buccal cavity where they start to function. Helix pomatia and Limax flavus were examined to determine whether the newly formed teeth already show their definite species specific shape, or whether they are gradually finished and moulded in the radular gland. Scanning electron micrographs of Helix pomatia show that teeth are secreted in the odontoblast region in their final form. Their surface is still uneven at the outset; the same is true for the newest teeth of Limax flavus. Older teeth ready for use have a smooth surface. This change seems to be brought about by secretory activity of the superior epithelium of the radular sac. Air-dried radulae, previously isolated by KOH maceration, show considerable artefacts at their posterior end. Maceration leads to shrinking of the newest teeth, but does not change their contours. The newly secreted but as yet unhardened teeth become greatly deformed during the drying process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    ISSN: 1432-0878
    Keywords: Fish thrombocyte ; Open canalicular system ; Three-dimensional architecture ; High voltage electron microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence and the three dimensional distribution of the surface connected canalicular system (SCCS) in thrombocytes of a teleost, Cyprinus carpio, were studied using a transmission electron microscope, a high voltage electron microscope and a scanning electron microscope. When the specimens were fixed routinely in glutaraldehyde followed by osmium tetroxide, numerous electron lucent vesicles and canaliculi were distributed throughout the cytoplasm. As ruthenium red-positive reaction product was observed on the inner surface of the vesicles and canaliculi, these are defined as the SCCS of carp thrombocytes. In the stereo-pair of the photographs of thick sectioned specimens and the plastic reconstruction of serially sectioned thrombocytes, we succeeded in finding the whole structure of the SCCS which is composed of numerous anastomosing canaliculi. Scanning electron micrographs revealed many crater-like depressions throughout the cell surface which seem to be the openings of the SCCS.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1432-0878
    Keywords: Salamander skin ; Skin capillaries ; Poison gland capillaries ; Microcorrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microcorrosion casts of blood vessels in the skin of the spotted salamander, Salamandra salamandra L., were studied using scanning electron microscopy. The investigated vessels include a subepidermal network of respiratory capillaries and the vessels of poison glands. A hypothesis is proposed, according to which both types of vascular beds possess a common origin. Probable factors involved in the differentiation of the primary netword of the subepidermal vessels in larvae are indicated and speculation concerning the supposed mosaic type of circulation in the capillaries of the subepidermal respiratory bed is presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 198 (1979), S. 129-136 
    ISSN: 1432-0878
    Keywords: Cerebral ventricles ; Ependyma ; Pores ; Subarachnoid space ; Scanning electron microscopy ; Amphibia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Scanning electron microscopy of the caudal end of the roof of the fourth cerebral ventricle in four amphibian species shows that numerous pores occur between the ependymal cells. These pores have diameters ranging from 5–100 μm; they permit bulk flow of cerebrospinal fluid out of the ventricular system into the subarachnoid space.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 196 (1979), S. 23-38 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mammals ; Three-dimensional organization ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenal cortex of different mammals was studied by SEM in order to demonstrate its actual three-dimensional organization. In the rat, as well as in the cat and pig, the adrenal cortex appeared as a “tunnelled continuum” of polyhedral cells arranged in plate-like structures (laminae). This laminar arrangement was more evident in the inner fasciculate and reticular zones where the cortex revealed a striking similarity to liver tissue. The polyhedral cells of all cortical zones possessed regular facets populated by small pits, larger invaginations and numerous microvilli with the exception of very short and smooth areas probably corresponding to attachment zones and/or gap junctions. This cellular architecture produced a labyrinthic system of intercellular channels or lacunae in which the capillaries were suspended. The pericapillary areas of this labyrinth contained microvilli, amorphous material, a delicate net of fibrils and occasional cells. The intercellular compartment of this lacunar system was mainly bordered by numerous microvilli arising from endocrine cells. The luminal surface of the capillary wall showed not only irregularly protruding margins (interpretable as endothelial junctions) but also clearly overlapping and flattened endothelial extensions. In all the animals and areas of the adrenal cortex examined, the endothelial wall was provided with abundant clusters of small fenestrations (about 50 nm in diameter) generally arranged in sieve plates. Larger fenestrations were noted mainly in the fasciculate and reticular zones of the cat and pig and occasionally in the rat. A final point related to the nature and significance of sinusoidal fenestrations was the occurrence of irregularly shaped and intracapillary located cells mainly noted in the deeper zones of the fasciculate and reticular zones of the gland. These elements — possessing the surface characteristics of macrophages — were observed, with their irregular and slender evaginations, in close proximity to the large fenestrations in a manner reminiscent of Kupffer cells within the lumen of liver sinusoids.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 197 (1979), S. 539-543 
    ISSN: 1432-0878
    Keywords: Ventricular surface ; Paraventricular organ ; Domestic fowl ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ventricular surface of the paraventricular organ in the domestic fowl is covered with supraependymal fiber elements. These fibers form a dense network having a web-like appearance and a coarse network of fibers running over the ventricular surface. The dense, web-like networks are mainly distributed throughout the caudal region of this organ, whereas the coarse networks are observed in the rostral region. In addition to these structures, spherical bodies with diameters approximately 2.5 to 6 μm are also encountered.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 135-139 
    ISSN: 1618-2650
    Keywords: Trenn. von Benzodiazepinen ; Chromatographie, Dünnschicht ; Metaboliten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die DC-Trennung von 14 1,4- bzw. 1,5-Benzodiazepinen und 17 Hauptmetaboliten sowie die Detektion mit Bratton-Marshall-, Dragendorff- und Jodoplateat-Reagens werden beschrieben. Rf-Werte sowie die Reaktionen mit den Reagentien sind tabellarisch zusammengestellt und Biotransformationsschemata angegeben.
    Notes: Summary Experimental details for the separation are described and data are compiled for Rf-values and reactions with Bratton-Marshall, Dragendorff and iodoplateate-reagents. Biotransformation schemes for the individual benzodiazepines are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 288-288 
    ISSN: 1618-2650
    Keywords: Nachw. von Ioxynil in Biolog. Material ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 263-265 
    ISSN: 1618-2650
    Keywords: Trenn. von Alkoholen ; Chromatographie, Dünnschicht ; C1-C20, 6 Trennsysteme, Dinitrobenzoate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary Thin-layer chromatography on rice starch, maize starch, cellulose and talc makes possible the separation of the homologous series of 3,5-dinitrobenzoates of aliphatic alcohols C1 to C20. Six different solvent systems have been employed. Dependence of R f-values on the number of C-atoms on various supports is discussed.
    Notes: Zusammenfassung Mit Hilfe der Dünnschicht-Chromatographie auf Reisstärke, Maisstärke, Cellulose und Talk wurde die homologe Reihe der 3,5-Dinitrobenzoate von aliphatischen Alkoholen C1 bis C20 getrennt. Sechs verschiedene Fließmittel wurden benutzt. Die Abhängigkeit der R f-Werte von der Zahl der C-Atome auf verschiedene Schichten wird diskutiert.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 272-272 
    ISSN: 1618-2650
    Keywords: Trenn. von Arylazopyraolen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 36-41 
    ISSN: 1618-2650
    Keywords: Trenn. von Antimikrobiellen Verbindungen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Trennung und Identifizierung von halogenierten, vorwiegend aliphatischen antimikrobiellen Verbindungen, von Formaldehyd abgebenden Substanzen und von Sulfonsäure-Derivaten auf dünnschicht-chromatographischem Wege wird beschrieben. Die Trennung erfolgt auf einer Kieselgel-Cellulose-Mischschicht mit Äthylacetat/Methanol/10% Ammoniak (65+30+5) als Laufmittel. Zur Sichtbarmachung und zur Identifizierung sind mehrere Sprühmittel notwendig: äthanolischeMethylgelb-Lösung mit anschließender UV-Bestrahlung, Phenylhydrazinsulfonat und Natronlauge sowie Hydroxylamin/Eisen(III)-chlorid und Nitroprussidnatrium-Kaliumhexacyanoferrat (III) u. a. Anhand der verschiedenen Rf-Werte und der Anfärbungen lassen sich die antimikrobiellen Verbindungen rasch und einfach identifizieren.
    Notes: Summary The analysis of halogenated, mainly aliphatic compounds, of formaldehyde donors and of derivatives of sulphonic acid is described. The separation is carried out on plates coated with a mixed layer of silica gel and cellulose and a solvent mixture of ethylacetate/methanol/10% ammonia (65+30+5), whereas for the detection and identification several spray reagents have to be used: ethanolic solution of Methyl Yellow with subsequent UV irradiation, phenylhydrazine-4-sulphonic acid and sodium hydroxide, hydroxylamine/iron(III) chloride, sodium nitroprusside/potassium hexacyanoferrate(III) and others. The Rf-values and the colourations of the spots allow to identify the examined compounds rapidly and without further chemical procedures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 42-42 
    ISSN: 1618-2650
    Keywords: Trenn. von anorg. Ionen ; Chromatographie, Dünnschicht ; DCTA-imprägniert
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 414-414 
    ISSN: 1618-2650
    Keywords: Identifizierung von Arylhydrazin-benzylsulfonylmethylpyrazolinonen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 299 (1979), S. 207-207 
    ISSN: 1618-2650
    Keywords: Analyse von Sulfonamiden ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 26 (1978), S. 237-241 
    ISSN: 1432-0827
    Keywords: Epiphyseal chondrocytes ; Freezefracture ; Scanning electron microscopy ; Cell processes ; Membrane particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chondrocytes in epiphyseal cartilage were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using freeze-fracture techniques. Freeze-fracture replicas showed large numbers of fingerlike, 0.11–0.15 μm diameter, projections from the chondrocyte surface, with numerous 95–180 Å diameter intramembranous particles associated with both the cell membrane surface and these projections. With SEM, these cytoplasmic projections were also obvious, but appeared collapsed into clusters of globular-shaped projections on the surface of the chondrocytes. With freeze-fracture techniques, in which shrinkage artifacts were essentially eliminated, the cytoplasmic projections were often seen in intimate contact with the extracapsular matrix. However, with chondrocytes prepared by both SEM and conventional TEM, there was evidence of shrinkage, the cytoplasmic projections having little contact with the extracapsular matrix. These findings show that the cytoplasmic processes are not artifacts of tissue processing and provide morphological evidence in support of the hypothesis that matrix vesicles are of cellular origin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 275-284 
    ISSN: 1432-1041
    Keywords: Diazepam ; pharmacokinetics ; pregnant women ; plasma clearance ; blood/plasma concentration ratio ; placental transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition of diazepam has been studied in pregnant women at parturition. The plasma concentration of diazepam was monitored for at least 3 days in 18 women who received a single intravenous injection of 10 mg during the 10 h-period prior to delivery. Fourteen mothers had uneventful puerperia (Group I) and in 13 of these cases there was a pronounced postnatal increase in the plasma concentration of diazepam. The terminal phase half-life (t1/2) was significantly greater for Group I (mean = 65 h; range = 24–114 h) than for age-matched non-pregnant patients (mean = 29 h; range = 18–44 h from literature). The prolonged t1/2 appeared to be related to changes in the distribution of diazepam and not to a reduction in hepatic elimination since the total plasma clearance (Cltp) in these 14 pregnant patients (mean = 28 ml/min; range = 18–43 ml/min) was not reduced compared to that reported for non-pregnant controls (mean = 30 ml/min; range = 22–45 ml/min). Four mothers underwent postnatal surgery for tubal ligation (Group II) and the plasma concentration-time profiles for this group did not show the same postnatal phenomenon as did the profiles obtained for Group I. The t1/2 for Group II was shorter (mean = 31 h; range = 24–37 h) than for Group I and similar to that for the non-pregnant controls. The Cltp for Group II was greater (mean = 56 ml/min; range = 48–63 ml/min) than for both Group I and non-pregnant controls. These results suggest that delivery alters the disposition of diazepam and is generally associated with a postnatal re-distribution of diazepam into the systemic circulation. The blood/plasma concentration ratio was determined in 9 patients (mean = 0.62; range = 0.54–0.77). There was no difference in the total blood clearance between the pregnant patients of Group I and the non-pregnant controls. In most cases the umbilical venous plasma concentration (Cpuv) of diazepam was greater than the peripheral maternal venous plasma concentration (Cpmv) at delivery. The foetus appears to constitute a slowly equilibrating tissue-group in which diazepam does not reach equilibrium with the maternal systemic circulation for at least 5–10 h at which time the diazepam concentration in maternal and foetal plasma is similar.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1432-1041
    Keywords: p-Chlorophenoxyisobutyric acid ; clofibrate ; steady-state plasma concentrations ; bioavailability ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma concentrations and bioavailability of clofibrinic acid have been estimated under conditions approaching the steady-state during a ten-day period of administration as clofibrate or as a calcium clofibrinate-carbonate combination (1:1 w/w) at a dosage interval of 12 h. Formulation — related differences in bioavailability were not significant, and the 95% confidence limits of these differences were within −2% to +8% of the mean for the reference formulation of clofibrate. The mean steadystate plasma concentrations of clofibrinic acid measured on the tenth day of dosing were 116 µg/ml±22 S.D. and 119 µg/ml±23 S.D. after administration of 885 mg as clofibrate and the calcium clofibrinate-carbonate combination respectively. The peaks of mean plasma concentrations were 70 µg/ml±15 S.D., 119 µg/ml±32 S.D. and 131 µg/ml±26 S.D. on the first, fifth and tenth day of dosing with clofibrate, and 62 µg/ml±13 S.D., 127 µg/ml±S.D. and 143 µg/ml±25 S.D. on the corresponding days of dosing with the calcium clofibrinate-carbonate combination. After the last dose on the tenth day of dosing, the mean apparent half-lives of elimination of clofibrinic acid from plasma were 24.2 h±4.4 S.D. and 25.5 h±3.2 S.D. after administration of clofibrate and the calcium clofibrinate-carbonate combination respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 69-72 
    ISSN: 1432-1041
    Keywords: Phenazone ; pharmacokinetics ; hydrocortisone ; elimination rate ; distribution volume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of a high plasma concentration of hydrocortisone on the metabolism of phenazone in humans has been studied. Two series of experiments were carried out, Group A to demonstrate any enzyme-inducing effect of hydrocortisone, and Group B to study the immediate effect of hydrocortisone on the metabolism of phenazone. 9 subjects (Group A) received a total 250–400 mg hydrocortisone i.m. twice daily for three days and the 24-hour elimination of phenazone was studied before and afterwards. In a further 5 subjects (Group B) the elimination of phenazone was examined during administration of hydrocortisone or placebo. The elimination rate and the apparent volume of distribution of phenazone remained unchanged under both experimental conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 97-101 
    ISSN: 1432-1041
    Keywords: Clonidine ; plasma level ; pharmacokinetics ; steady state ; urinary excretion ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A single oral dose of clonidine 300 µg was administered to 8 healthy, normotensive subjects and the time course of its plasma concentrations was followed for 24 h. The plasma concentration of clonidine rose to a peak of 1.17±0.12 ng/ml at about 2 h: the absorption half-life was 0.6±0.2 h. Elimination followed first order kinetics with a half-life of 7.7±2.0 h. The correlation between the two most common side-effects of clonidine, sedation and dryness of the mouth, with the time course of its plasma concentrations was highly significant, p〈0.01. All the subjects complained of severe sedation. During continuous administration of clonidine (75 µg t.i.d.) for one week a steady state serum level of 0.30–0.35 ng/ml was achieved. One 75 µg tablet of clonidine raised the serum level to about 0.69±0.13 ng/ml in two hours. After cessation of dosing, the serum level declined with a half-life of 7.5±1.5 h. The urinary excretion of unchanged clonidine was found to be about onethird of the administered dose in 24 h during continuous administration and in the first 24 h after the single oral dose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 14 (1978), S. 203-212 
    ISSN: 1432-1041
    Keywords: Mepivacaine ; pharmacokinetics ; neonates ; healthy adults ; metabolism ; renal excretion ; lignocaine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and metabolism of mepivacaine has been studied in premature neonates dosed subcutaneously and in healthy adults dosed intravenously. The pharmacokinetics of mepivacaine in four neonates (N) was compared with that in six adults (A). Newborns had a significantly longer terminal phase half-life than adults (N mean 8.69 h; A mean 3.17 h). Total plasma clearance normalized on body weight was significantly smaller in neonates (mean 2.34 ml/min/kg) than in adults (mean 5.47 ml/min/kg), as was the hepatic blood clearance (N mean 1.37 ml/min/kg; A mean 5.10 ml/min/kg). The renal plasma clearance, however, was significantly greater in neonates (mean 0.76 ml/min/kg) than adults (mean 0.20 ml/min/kg). There was an average six-fold increase in the fraction of the dose excreted unchanged in newborns (mean 43.3%) compared to adults (mean 7.1%) with acidified urine (pH 5.5–6.0). There was significantly more of the mono-N-demethylated metabolite of mepivacaine excreted by newborns (mean 11.4%) than by adults (mean 2.2%), but their capacity to carry out aromatic hydroxylation of mepivacaine was negligible. These results for mepivacaine were compared with those previously reported for lignocaine in premature infants. The immaturity of hepatic function appears to have diminished more profoundly the ability of premature infants to metabolize mepivacaine than lignocaine. These findings are discussed in terms of perfusion theory of hepatic drug elimination.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 14 (1978), S. 143-147 
    ISSN: 1432-1041
    Keywords: Children ; leukemia ; high-dose methotrexate ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of intravenous high-dose methotrexate were studied in two groups of children being treated for malignant diseases, mostly acute lymphatic leukemia. The peak serum level of methotrexate of 2.32·10−5 mol/l was found in children given 500 mg methotrexate/m2 by a 24 h infusion, and another group given 2790 mg/m2 during a 6 h infusion had serum levels as high as 2.16·10−4 mol/l. The decay of serum concentration of methotrexate after completion of the infusion followed a diphasic curve, with an initial serum half-life of 4.8 h, followed by a second half-life of 34.4 h at distribution equilibrium. The apparent volume of distribution was 56.8 litres/m2. Significant levels of methotrexate were found in cerebrospinal fluid, but penetration into cerebrospinal fluid was slow. Urinary excretion of methotrexate was considerable. Four to five days after commencement of the infusion, urinary concentrations of methotrexate still exceeded the serum levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 14 (1978), S. 335-340 
    ISSN: 1432-1041
    Keywords: Drug binding to muscle ; interindividual differences ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Binding of 22 drugs to human muscle tissue has been determined by ultrafiltration. All drugs tested were bound, the bound fraction ranging from 13% (aminophenazone) to 〉98% (desipramine). Both linear and nonlinear binding was observed. For chemically related substances, binding to muscle tissue correlated with plasma binding and lipid solubility. There were significant differences in binding to muscle from different individuals. With respect to pharmacokinetics of drugs, it is suggested that binding to muscle tissue may be at least as important as plasma binding.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 41-48 
    ISSN: 1432-1041
    Keywords: Furosemide ; pharmacokinetics ; anephric patients ; metabolism ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of furosemide 40 mg i.v. were compared in 7 anephric patients and in 7 normal subjects. The average serum clearance was 66 ml/min in the patients and 219 ml/min in the normal subjects, and the corresponding weight corrected clearances were 1.33 ml/min · kg and 2.96 ml/min · kg. Binding to serum proteins was significantly decreased in the anephric subjects, in whom a significant negative correlation was found between the percentage binding and the volume of distribution VDss. In the patients, but not in the normal subjects, there was a significant positive correlation between $$V_{D_{ss} } $$ and serum clearance. Both in normal and anephric individuals 4-chlor-5-sulphamoylanthranilic-acid (CSA) was found, but there was no evidence of special accumulation either of CSA or anthranilic acid in the anephric patients. In the patients the initial increase in serum concentration of sodium and protein followed by a more conspicuous decrease were more pronounced, but none of the changes were statistically significant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 29-33 
    ISSN: 1432-1041
    Keywords: Microcrystalline theophylline ; chronic obstructive airways disease ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma theophylline concentrations have been measured in 9 patients with chronic obstructive airways disease following the oral administration of a microcrystalline theophylline preparation. Some measurements of FEV1 were also made. Four patients were given 375 mg as a single dose and then subsequently 375 mg stat and 125 mg 4 times daily for 3 days, (Group I). A further 5 patients took 250 mg as a single dose and then 250 mg 4 times daily for 3 days, (Group II). In both groups, following the single dose and again after the last dose of chronic administration, blood samples were obtained at frequent intervals up to 24 h for plasma drug estimation. During the 3-day course, blood samples were drawn before and 2 h after each morning dose. In Group I patients, substantial plasma theophylline concentrations were seen only after the loading dose. Thereafter, the mean concentrations before or 2 h after the morning doese were always less than 4.0 µg/ml. Trough concentrations were usually below 2.0 µg/ml. In contrast patients in Group II achieved substantially higher plasma theophylline concentrations, with mean peak concentrations always 10 µg/ml or greater, and trough concentrations greater than 5 µg/ml on at least one occasion in every subject. The elimination half-lives after chronic administration in both groups were not significantly different from those obtained after single doses. Mean drug accumulation, measured as AUCss/AUC1, was 0.87±0.07 in Group I and 0.72±0.14 in Group II, indicating that accumulation had not occurred with either regimen. The mean increase in FEV1 2 h after the administration of a single dose was 19.2% after 375 mg and 16.7% after 250 mg. These results indicate that the recommended dosage regimen for microcrystalline theophylline preparation (375 mg stat and 125 mg 4 times daily) produces inadequate plasma theophylline concentrations: 250 mg 4 times daily would appear to be likely to result in satisfactory theophylline levels in more patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 365-371 
    ISSN: 1432-1041
    Keywords: Etidocaine ; pharmacokinetics ; metabolism ; neonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The urinary elimination of etidocaine and several of its metabolites was investigated in neonates whose mothers had received one or more doses of etidocaine during labour. The urine collection period ranged among the neonates from 21.4 to 47.0 h post-partum. The total amounts of etidocaine and its metabolites recovered in neonatal urine represented a mean of 0.12 per cent of the maternal dose. Some differences in the pattern of urinary metabolites were observed between neonates and adults. Mean half-life of elimination of etidocaine calculated from sigma-minus plots of the neonatal urinary data was 6.42 h. This is greater than that previously reported following intravenous administration of etidocaine to adults (2.6 h). The slower rate of elimination in neonates is probably due to an increased neonatal volume of distribution since there is evidence to show that etidocaine is extensively metabolised by the neonate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...