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Biomedical subjects

D Berdel

Publications and source records attributed to D Berdel.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Impedance of the respiratory tract of healthy newborn infants--studies using the polyfrequency oscillation method].

Resistance and reactance of the respiratory tract of 40 healthy newborn were measured by means of the polyfrequent oscillation method. Mean resistance had frequency-dependent values between 20.91 and 9.63 cm H2O per litre per second and mean reactance between -29.11 and -3.81 cm H2O/1/s. The resistance--but not the reactance--was found to depend on the body length and the body weight of the infants.

Airway Resistance↗
PubMed1989

Monitoring theophylline levels in serum and saliva using fluorescence polarization immunoassay and Seralyzer.

The reliability and predictive value of salivary theophylline levels was investigated in 58 children who were treated with oral sustained-release theophylline preparations for bronchial asthma. Serum and saliva levels were assessed by fluorescence polarization immunoassay (FPIA), and Seralyzer (reagent strip reflectance photometer method). Forty-six paired serum and saliva samples from 28 patients (Group 1) were used to develop a linear regression formula. This formula was tested on 130 paired serum and saliva samples from 32 patients (Group 2). When saliva theophylline levels were assayed using FPIA, 95% of serum levels were predicted within 30% of the measured value. Using Seralyzer, 95% of serum levels were predicted within 45% of the measured value. For patients with three and more paired serum and saliva specimens, individual regression formulas were determined showing considerable variation. This study indicates that salivary theophylline levels provide for an estimation of serum levels if FPIA is used. The Seralyzer technique is only useful for serum theophylline measurements. Using a special device it is now easier to obtain saliva samples than by conventional methods.

Adolescent↗
PubMed1989

Formoterol and salbutamol metered aerosols: comparison of a new and an established beta-2-agonist for their bronchodilating efficacy in the treatment of childhood bronchial asthma.

In this placebo-controlled, double-blind, single-dose study the new beta-2-agonist formoterol (one puff, 12 micrograms) was intraindividually compared with salbutamol (one puff, 100 micrograms) for onset, magnitude, and duration of bronchodilating efficacy in 15 young asthmatics aged 5 to 14 years with mild to severe asthma. All but one had regular antiasthmatic medication before beginning the study, but none was oral steroid dependent. Both medications produced rapid bronchodilatation within 10 minutes, reflected by a decrease in specific airway resistance (sRaw) with maximum effects at 10 minutes (salbutamol, 51%) and 30 minutes (formoterol, 60%). Significant bronchodilation was present at 10 minutes to 2 hours after inhalation of salbutamol and at 30 minutes to 8 hours after formoterol. Mean percent improvement over baseline was higher for formoterol at all measured times from 30 minutes to 12 hours, when 55% mean decrease in sRaw was still present. The effect of salbutamol was a less than 10% mean decrease in sRaw after 6 hours. The differences in sRaw decrease between the two medications were statistically significant at 4 to 10 hours after inhalation. Neither medication administered as an aerosol caused cardiac side effects. Both had a rapid onset of action and a comparable maximal effect. However, at the doses studied, formoterol produced a larger decrease in sRaw from baseline for longer periods after inhalation than did salbutamol.

Administration, Inhalation↗
PubMed1989

Renal clearance of theophylline and its major metabolites: age and urine flow dependency in paediatric patients.

The renal clearance of theophylline (TH) and its metabolites 1,3-dimethyluric acid (1,3-DMU), 3-methylxanthine (3-MX), and 1-methyluric acid (1-MU) has been studied in 10 children aged 8 months to 14 years. Individual renal clearances were calculated from serum levels and amounts excreted in urine after i.v. administration of the parent drug. The clearance of 1,3-DMU was found to depend both upon urine flow rate and age, which are interrelated. An effect of urinary pH was expected, but was not studied. Consistent age-dependent changes in the relative quantities of metabolites excreted were not observed.

Adolescent↗
PubMed1989

[Oscillatory impedance measurement of the respiratory tract in children].

The author reports on his own experiences with monofrequent and polyfrequent oscillatory impedance measurements of the respiratory tract in childhood. The monofrequent oscillatory process was tested in a total of 10 trials in respect of its suitability to estimate the complex respiratory resistance in the region of lower and upper respiratory tract in a total of 1071 children most of whom were healthy, some children having a diseased respiratory tract, between 3 and 19 years of age. In 268 children the nasal respiratory resistance was measured, in 803 the bronchial respiratory resistance. The polyfrequent oscillation method was compared in 2 examinations with body plethysmography and spirometry in respect of its discriminatory powers between healthy subjects and children suffering from asthma, and in respect of its suitability to prove bronchial hypersensitivity on carbachol provocation, using 93 healthy and 81 asthmatic children. The results of the 12 examinarions are surveyed and discussed.

Adolescent↗
PubMed1989

[Bronchial provocation in children: a comparison between the polyfrequent oscillation method and body plethysmography].

With the aid of the forced oscillation technique (FOT), parameters of the mechanics of respiration are measured with a minimum requirement of patient cooperation. This means that this technique is particularly suitable for use in children. The resistance (Rrs) established with the FOT correlates well with the airway resistance (Raw) measured with whole-body plethysmography (BP) (2, 4). So far, the blind resistance (Xrs) also simultaneously measurable with FOT, has received but little attention. The objective of this investigation was, in children, to compare all the resistances measurable with FOT with the parameters of BP during bronchial provocations with carbachol.

Adolescent↗
PubMed1987

Total theophylline clearance in childhood: the influence of age-dependent changes in metabolism and elimination.

Theophylline metabolism and elimination during childhood are age-dependent. The total clearance, which is the sum of metabolic and renal clearances is highest in infants and young children. To differentiate between the two pathways, theophylline concentrations were measured in both serum and urine in 16 children aged 2 weeks-16 years using the fluorescence polarization immunoassay. It was found that both partial clearances assume maximal values at about the same age, but the fraction of total clearance attributable to the renal route decreases continuously.

Adolescent↗
PubMed1987

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↗
PubMed1984

[Peculiarities of the pharmacokinetics and pharmacodynamics of theophylline in children].

Pharmacologically relevant factors such as enteral absorption, distribution, metabolism and excretion are age-dependent. The absorption of theophylline given in aqueous solution to prenatal infants with apnoea is markedly reduced when administered along with the infant's feed. The metabolic pathway of theophylline depends on the age group. Newborn and older infants form the pharmacodynamically active metabolite, caffeine. The main metabolites 1.3-dimethyl-uric acid and 3-methylxanthine are detectable, as in adults, but 1-methyl-uric acid remains below the demonstrable serum concentration level in infants of our study. The elimination velocity of theophylline is also dependent on the age. In order to achieve effective theophylline concentrations in the serum with oral preparations the galenic properties of the sustained-release products are decisive. By contrast, there was no difference between intravenous administration as permanent infusion or bolus injection. The data presented underline that in the treatment of apnea in premature infants as well as in the treatment of asthma in older children individual controls of serum concentrations are required to achieve further improvement of therapeutic success.

Adolescent↗
PubMed1984

Spontaneous flow measurements of laryngotracheal resistance in 30 tracheostoma patients.

The airway resistance of 30 patients with stenosis in the region of the larynx and upper trachea was assessed by means of the spontaneous flow method. For this purpose, the measuring head of a spontaneous flow rhinomanometer (A 440 rhinomanometer, Allergopharma, Reinbek, FRG) was adapted to the new conditions. Laryngotracheal airway resistance between 1.8 and 30 mbar/l/s was registered. This method proved to be suitable for measuring the airway resistance of the larynx and upper trachea in tracheostoma patients with varying degrees of stenosis. Thus, a further objective parameter has been added to those of inspection and X-rays for reviewing the indications for tracheostoma closure.

Adolescent↗
PubMed1984

[Measurements of airway resistance in stenosis of the laryngo-tracheal region].

The airway resistance of 32 patients with tracheostomies due to tracheal or laryngeal stenoses was measured using the autoflow and the oscillation method. The resistance to flow between the mouth and tracheostomy was determined with the autoflow method. While measuring with the oscillation method the tracheostoma was blocked with stomahaesive . The comparison of both methods resulted in a good correlation (r2 = 0.83). Hence, the oscillation method can be used to determine airway resistance in patients with stenosis of the larynx or trachea, irrespective of whether or not they have a tracheostome .

Airway Resistance↗
PubMed1983

[Comparison of active foreign flow rhinomanometry (oscillation method) and active personal flow rhinomanometry in 17 patients before and after correction of the nasal septum].

The nasal resistance of 17 patients with nasal septum deviation was measured before and after septum correction using two active rhinomanometric methods; the one with external flow (oscillation method), the other with spontaneous flow. Both methods correlated closely (p less than 0.01). The oscillation method proved to be as reliable and sensitive as the spontaneous flow method and less strenuous for the patient. Conventional rhinomanometric methods have failed especially in children because of their great demands on the patient's compliance; thus the oscillation method serves to increase the clinical application of rhinomanometry.

Airway Resistance↗
PubMed1983

A comparison of the multi-test with the prick test and multi-test 2.

Allergy skin testing of infants and small children continues to be time-consuming and nerve-wracking. We hoped to have found the solution to these problems by using the multi-test (MT). The latter consists of an applicator with 8 heads, each head consisting of nine plastic needles on which the allergen solution rests. Thus eight allergens can be tested simultaneously. During routine control skin testing we compared MT with our usual method, the prick test (PT), amongst twenty patients. Twenty-seven per cent of the skin reactions differed by more than 1+. When we compared PT results with the previous PT, the correlation of 16% was better despite several years interval between tests, different persons carrying out the tests, and hyposensitization of patients. We adapted the MT system and produced a model, multi-test 2 (MT-2), which consists of eight sterile disposable needles on a stainless steel base. When we compared the MT-2 with PT, only 6% differed by more than 1+. Thus the MT-2 proves to be a useful alternative to the PT for those children, in whom the PT is too difficult to carry out.

Adolescent↗
PubMed1981

[Significance of measurement of the oscillatory resistance to respiration in children. (author's transl)].

The oscillatory resistance to respiration (Ros) was measured in 218 children and 260 adults using the Siregnost FD5 (Siemens, Erlangen), and compared with whole body plethysmography (Raw) and with spirometry. There was a markedly better correlation between Ros and Raw (r=0.82;n=88) in children than in adults (r=0.53;n=260). Whereas additional recording of the phase angle in children does not yield any substantial additional information, it is of diagnostic importance in adults. Comparison of Ros with the spirometric values yielded the following sequence of decreasing correlation coefficients (linear regression): FEV1.0, PEF, V 75, MMEF, V 50, V 25, whereas in adults these relationships cannot be described by means of a linear correlation. The results enable us to conclude that in paediatric pneumology an alternative use of whole-body plethysmography and of oscillatory method appears justified.

Adolescent↗
PubMed1981

Human antibodies against antigens of the sparrow, blackbird, weaver finch, canary, budgerigar, pigeon and hen using the indirect immunofluorescent technique.

Detection of antibodies against various birds, particularly against exotic birds, can be facilitated using the sensitive immunofluorescent technique on avian fixed-intestine cryostat sections. Different fluorescent patterns corresponding to different human anti-avian antibodies have been observed. Sixty of 100 human sera containing antibodies against one avian species, predominantly pigeon, reacted also with all other avian species intestines; the remaining forty were more specific and reacted with a few species only. Cross reactions with antigens in song bird intestines indicated the presence of a broad spectrum of antibodies in patients with bird fancier's lung.

Animals↗