PubMed Health⌕ Search

Biomedical subjects

H Staudinger

Publications and source records attributed to H Staudinger.

At least 19 recordsLinked to original sources

A 12-week, placebo-controlled study of the efficacy and safety of ebastine, 10 and 20 mg once daily, in the treatment of perennial allergic rhinitis. Multicentre Study Group.

This double-blind, placebo-controlled, multicentre study investigated the ability of ebastine, 10 and 20 mg once daily, to control symptoms of perennial allergic rhinitis (PAR) over a 12-week period, and assessed additional benefits of the 20-mg dose. Following a 2-week baseline period, patients (12-63 years) were randomized to treatment with ebastine 10 mg (n=88) or 20 mg (n=102), or placebo (n=100). Patients scored symptom severity (0-3) twice daily, and mean changes from baseline scores showed ebastine to be significantly effective in week 1. Control of symptoms persisted over the 12 weeks, the average daily total nasal symptom score for nasal stuffiness plus nasal discharge plus sneezing plus itchy nose being reduced by both doses, with statistical significance at 20 mg (P=0.015 vs placebo) despite decreased usage of sodium cromoglycate rescue medications. Patient and clinician final opinions of treatment also significantly favoured ebastine, both 10 and 20 mg, over placebo. No serious adverse events occurred, and study treatments were well tolerated with a low incidence of central nervous system-related adverse events and headache. In conclusion, ebastine 10 or 20 mg once daily was rapidly effective in relieving symptoms of PAR in adult and adolescent patients; additional benefits of the 20-mg dose became apparent in the longer term.

Adolescent↗

An M1-selective muscarinic receptor antagonist telenzepine improves lung function in patients with chronic obstructive bronchitis.

The effect of an M1-selective muscarinic receptor antagonist telenzepine on lung function was investigated in 18 patients with chronic obstructive bronchitis in a double blind, placebo-controlled, randomized crossover study. FEV1, FEF50, PEF and FVC were measured every 0.5 h up to 2 h, then every 1 h up to 6 h after administration of a single, oral dose of 5 mg in the morning. Compared with placebo, telenzepine increased (time average over 6 hours; median and 68%-range): 1) FEV1 from 1.46 (0.81, 2.06) to 1.67 (1.06, 2.40) l, p less than 0.01; 2) PEF from 3.58 (2.33, 4.55) to 3.88 (3.10, 5.07) l/s, p less than 0.01; 3) FEF50 from 0.93 (0.45, 1.58) to 1.17 (0.67, 1.90) l/s, p less than 0.001. Whereas the median increase in FEV1 15 min after 2 puffs of salbutamol was 20% (range 15 to 74%), FEV1 improved by 32% (range -15 to 130%) at the time of maximum difference between placebo and telenzepine. The heart rate did not change. We conclude that in patients with chronic obstructive bronchitis substantial improvement of lung function parameters can be achieved by an M1-receptor antagonist. It is possible that with the dose administered direct actions on muscarinic receptors on the smooth muscle (M3) contribute to the observed bronchodilatation. The unchanged heart rate indicates little effect on cardiac M2-receptors.

Administration, Oral↗

Twenty-four hour lung function in adult patients with asthma. Chronoptimized theophylline therapy once-daily dosing in the evening versus conventional twice-daily dosing.

Many patients with asthma experience a worsening of symptoms at night and in the early morning, resulting in sleep disruption and possibly altered daily performance. A bronchodilator agent that exerts its maximal effect overnight to control nocturnal symptoms, without a worsening of the disease during the daytime, should improve the treatment of asthma. This investigation examined the efficacy and kinetics of a new chronotherapeutically optimized, sustained-release theophylline formulation administered once daily (OD) in the evening at 8:00 P.M. in comparison with a conventional sustained-release theophylline administered twice daily (TD) at 8:00 A.M. and at 8:00 P.M. in the same dose. After a theophylline clearance study to substantiate normal or slow metabolism of the drug, a dose-titration period, and a 24-h baseline spirometric study of patients not receiving any medication, participants were randomized to 7-day treatment phases with either OD or TD. Each outpatient segment of 6 days of OD and TD was followed by a 24-h inpatient study on Day 7 when serum drug level and spirometric (PEF, FEV1, and FEF25-75) parameters were obtained every 2 h. The conventional TD treatment was associated with a constant serum theophylline level over the 24 h. In contrast, the OD treatment was associated with larger peak-to-trough drug level fluctuation, with higher levels produced overnight and lower ones in the evening at the end of the dosing interval. Compared with the baseline references, both OD and TD significantly improved airflow over the entire 24 h and to a comparable extent. However, between 2:00 and 6:00 A.M., PEF and FEV1 were significantly greater with OD than with TD. The improvement in PEF and FEV1 at this time, because of OD, was correlated with the serum theophylline level. This was not the case for TD. The improvement in airflow over baseline values between 2:00 and 6:00 P.M. was not correlated with theophylline level with either treatment regime. Overall, the chronotherapeutically conceptualized OD treatment administered in the evening resulted in better airflow levels overnight than did the TD regime without loss of airflow in the afternoon.

Adult↗

Pharmacokinetic profile of a new sustained-release theophylline pellet formulation for once-daily evening administration.

Euphylong is a new anhydrous theophylline sustained-release pellet formulation developed for once-daily administration in the evening in normal and slow metabolizers, and unequally divided twice-daily administration in fast metabolizers. Its pharmacokinetics have been investigated with respect to bioavailability, peak-trough fluctuation, nocturnal plateau profile, food effects, predictability and reproducibility between subjects and from day to day. To this end, 7 single-dose and 4 multiple-dose, randomized, cross-over studies were performed in a total of 168 healthy, normal, male volunteers. In order to match the dosage strengths of three reference products, capsules containing different amounts of pellets--also referred to as Euphylong pellets--have been used. Absolute bioavailability of theophylline from Euphylong was 88 and 100%, depending on the rate and the total dose of the intravenous reference infusions. Relative bioavailability ranged between 85 and 112%, depending on the reference formulations. The peak-trough fluctuation was reduced for Euphylong pellets in comparison with other once-daily theophyllines, by more than 30% in the case of a reference tablet. In contrast to another once-daily theophylline capsule, Euphylong pellets seem to be hardly affected by meals. Moreover, in view of the known variability of theophylline pharmacokinetics both between subjects and from day to day, the nocturnal plateau profile, which is characteristic of Euphylong, is extremely reproducible. The nocturnal excess is consistently 30-40% and the plateau time is consistently 11-12 h in normal metabolizers. The long nocturnal plateau profile together with the high reproducibility of Euphylong pharmacokinetics enable an easy and safe adjustment of the dose tailored to the needs of the individual patient. In addition, the time of the evening dose and its relationship to meals is not critical in the case of Euphylong pellets. Particularly patients presenting with nocturnal asthma, which is one of the major areas of theophylline therapy, should have a clinically relevant benefit from Euphylong.

Absorption↗

Theophylline therapeutic drug monitoring in the case of a new sustained-release pellet formulation for once-daily evening administration.

In view of the large interindividual differences in theophylline clearance and the narrow therapeutic range it is essential to individualize the theophylline dose. In order to do so, estimation of minimum and maximum serum theophylline concentrations during one dosing interval from one or two blood samples is desirable, particularly in the case of once-daily administration. Whereas the minimum (trough) concentration can be readily estimated from the pre-dose level, the maximum (peak) concentration occurs at night. For Euphylong, a new sustained-release theophylline pellet formulation, administered once-daily in the evening, for example between 7 p.m. and 8 p.m., the nocturnal maximum concentration can be calculated as 110-120% of the serum theophylline concentration determined from a blood sample taken in the early morning, for example between 7 a.m. and 8 a.m. This procedure works not only for mean data but also on an individual basis. The procedure is based on the extended nocturnal plateau profile of Euphylong with its high reproducibility and cannot be transferred to other formulations.

Delayed-Action Preparations↗

Steady state pharmacokinetics, metabolism and pharmacodynamics of theophylline in children after unequal twice-daily dosing of a new sustained-release formulation.

This was an open-label study in 19 children aged 9-13 years, weighing 27-44 kg, with bronchial asthma. Twenty-four-hour steady-state concentrations of theophylline and its metabolites 1,3-dimethyl uric acid, 3-methyl xanthine and 1-methyl uric acid were assessed after daily dosing of 600 mg (ca 18 mg/kg/day) of the sustained-release theophylline micro-pellet sprinkle system BY158K, for 4 days. The dosing regimen used was an unequal twice-daily dose of 200 mg in the morning after breakfast and 400 mg in the evening after dinner. Twenty-four-hour peak expiratory flow (PEF) profiles were compared before treatment and at steady-state, along with lung function parameters after bronchial provocation. Mean values +/- SD (n = 16) of the steady-state characteristics were Cmin 6.8 +/- 2.1 mg/l, Cmax 14.5 +/- 4.8 mg/l and Cav 10.5 +/- 2.9 mg/l, the plateau time was 11.7 +/- 4.8 hr and peak-trough fluctuation and swing were 72 +/- 21 and 118 +/- 52%, respectively. There was an excellent reproducibility of theophylline pre-dose levels at corresponding time points of the 24-hr sampling period [r = 0.864 (p less than 0.001)]. Mean values +/- SD of the 24 hr average serum metabolite levels were 0.9 +/- 0.2 mg/1 for 1,3-dimethyl uric acid, 0.6 +/- 0.1 mg/1 for 3-methyl xanthine and 0.4 +/- 0.1 mg/1 for l-methyl uric acid. Lung function (n = 17) following bronchial provocation, improved in 10 children after theophylline treatment of 4 days, remained stable in 2 patients and deteriorated in 5 patients. Serum theophylline profiles and PEF profiles ran largely in parallel over the 24-hr period. Six children exhibited typical theophylline induced side-effects, headache (n = 3), nausea (n = 4), dizziness (n = 1), vomiting (n = 4), sleep disturbances (n = 1), pallor (n = 1) and tremor (n = 1), necessitating in 3 children one dose omission/reduction (n = 2) or subsequent dose reduction (n = 1). It has been shown that a twice daily dosing regimen with unequal doses of anhydrous theophylline (BY158K) is well suited to this population of fast metabolisers. The patients were well protected throughout the day, including the critical early morning hours.

Asthma↗

[To play God?].

Explore the source record for details and available documents.

Ethics, Professional↗

Chemiluminescence and immune cell activation. I. Early activation of rat thymocytes can be monitored by chemiluminescence measurements.

Immediately after the addition of concanavalin A, rat thymocytes respond, in the presence of luminol, with a burst of chemiluminescence (CL) that can be conveniently monitored in an ordinary liquid scintillation spectrometer. Peak CL is reached after 50 sec. Addition of catalase suppresses 65% of the CL, suggesting that H2O2 generation may be its major source. CL with different kinetic characteristics can also be generated by the calcium ionophore A23187. Our rat thymocytes contain approximately 0.1% endogenous macrophages. Bone marrow-derived rat macrophages also respond to concanavalin A or A23187 stimulation with a burst of CL. However, the kinetic properties of CL as well as the inhibition of CL by catalase in these cells differ markedly from those of thymocyte preparations, suggesting that the major portion of the CL in rat thymocytes actually originates in T lymphocytes. Because CL measurements allow the monitoring of very early events in cell activation and because of the simplicity of the technique, CL measurements may become a useful method for the study of lymphocyte activation, of macrophage-lymphocyte interactions, as well as for the rapid screening for specificity and reactivity of T lymphocyte populations.

Animals↗

A 4-methoxybenzoate O-demethylase from Pseudomonas putida. A new type of monooxygenase system.

A strain of Pseudomonas putida grown on 4-methoxybenzoate as sole carbon source contains an enzyme system for the O-demethylation of this substrate. The enzyme system is purifiable and can be separated into two components: an NADH-dependent reductase and an iron-containing and acid-labile-sulfur-containing monooxygenase. The reductase, of molecular weight 42000 and containing two chromophores, an FMN and an iron-sulfur complex (EPR at g = 1.95), reduces both one-electron and two-electron acceptors (i.e., ferricyanide, 2,6-dichloroindophenol, cytochrome c, and cytochrome b5) at an optimum pH of 8.0. Increasing ionic strength affects these activities differently. The absolute spectrum of the oxidized displays distinct absorption peaks at 409 and 463 nm and a small shoulder between 538 and 554 nm. Treatment with dithionite or NADH reduces the absorbance throughout the visible range, yielding a spectrum with small maxima at 402 and 538 nm. Spectroscopic characteristics of the reductase indicate a tight coupling between its two chromophores. The iron-containing and acid-labile-sulfur-containing monooxygenase, which has a molecular weight of about 120000, contains an iron-sulfur chromophore with an EPR signal at g = 1.90. This protein is a dimer whose subunits each have a molecular weight of about 50000 and are perhaps identical. The optical absorption properties are somewhat unusual. In contrast to other iron-sulfur proteins, there is no significant peak near 415 nm in the absorption spectrum of the oxidized protein, but rather one at 455 nm. The presence of the substrate 4-methoxybenzoate increases both the NADH-dependent reductase. Hydroxylation can be achieved by the monooxygenase also in absence of the reductase with artifical reductants. This enzyme opens a new group of oxygenases within the classification scheme, i.e., iron-containing and labile-sulfur-containing monooxygenases. From the reported data, a scheme for the interaction of the isolated pigments and their relationship to various acceptors is proposed.

Animals↗

[Structure and function of the endoplasmic reticulum].

After a general review of enzyme topology and the molecular architecture of endoplasmic reticulum the latest research results are discussed. Microsomal enzymes do not occur in specialized regions of the endoplasmic reticulum but are uniformly distributed over the entire membrane system. Functionally associated enzymes are also located in the direct vicinity of the membrane. It has been shown that the catalytic activity of integral enzyme proteins depends on phospholipid and membrane structure. These membrane-bound lipoproteid complexes exert specific effects as vectorial enzyme catalysts. The endoplasmic reticulum is active is active in the intracellular transport of metabolites.

Animals↗