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Biomedical subjects

R Kraemer

Publications and source records attributed to R Kraemer.

At least 127 records · Page 7Linked to original sources
PubMed1984

[How useful is the ultrastructural study of the cilia of the respiratory tract in the diagnosis of an immotile cilia syndrome?].

The immotile cilia syndrome (ICS) comprises a range of congenital defects of the ciliary apparatus most probably transmitted by autosomal recessive inheritance. Because cilia occur mainly in the respiratory and genital tract, the clinical symptoms of ICS are most commonly chronic sinusitis, bronchitis, bronchiectasis and male sterility. The syndrome can be associated with a situs inversus and is then called Kartagener's syndrome. We studied the ciliary ultrastructure in airway biopsies of 5 patients suffering from chronic upper and lower respiratory tract infections. With the single exception of one female patient with confirmed ICS diagnosis (Kartagener's syndrome) the etiology of the recurrent infections was unknown. The following ciliary defects were observed: missing dynein arms, radial spoke defects, missing nexin links, microtubular transpositions, compound cilia, supernumerary, absent, or incomplete microtubules, lack of ciliary orientation and various abnormal patterns of microtubular arrangement. In no instance did a patient show only a single anomaly; defects were always combined. Missing dynein arms, radial spoke defects and microtubular transpositions have frequently been described as lesions specific for ICS. Whenever these lesions were found simultaneously in both the respiratory and genital tracts, their genetic origin cannot be doubted. In our confirmed ICS patient the outer dynein arms were not missing but were reduced in number and length in a large number of cilia. The biopsy was, however, obtained from the heavily infected maxillary sinus and it is known that inflammation can lead to a loss of dynein arms. In the light of our investigations and of a review of the published cases of ciliary anomalies, it is concluded that none of the above defects in itself is specific for ICS. They may all occur as secondary lesions or sporadically as varieties in otherwise healthy subjects. It therefore appears questionable whether ICS can be diagnosed from the ciliary ultrastructure of a single airway biopsy. Assessment of ICS cannot be based simply on the ultrastructural demonstration of a particular ciliary defect, but necessitates additional considerations particularly regarding the origin of the biopsy, the sampling procedures and quantitation of defects. It appears necessary to investigate samples from different parts of the airways and quantitatively analyze the prominent lesions.

Abnormalities, Multiple↗
PubMed1984

Early diagnosis of cystic fibrosis by means of sweat microosmometry.

A modified sweat test procedure was studied to evaluate its practicability in the diagnosis of cystic fibrosis in newborn infants. By means of vapor pressure osmometry, we measured sweat osmolality in 131 healthy children and 63 patients with CF. Reference values were determined according to age: healthy infants 4 to 9 days of age; 121 +/- 23 mmol/kg (mean +/- SD); healthy infants 10 days to 2 months, 109 +/- 13 mmol/kg; healthy infants 2 to 12 months, 86 +/- 13 mmol/kg; and healthy children and adults 2 to 23 years, 105 +/- 14 mmol/kg. The mean of corresponding values for the 63 patients with CF was 267 +/- 34 mmol/kg. There was no overlap of values in any age group, even when the 2 SD limit was taken into account. Thus the diagnosis of CF can be made by means of this approach in newborn infants 8 days of age or older.

Adolescent↗
PubMed1984

Lung distensibility and airway function in asthmatic children.

Lung distensibility and airway mechanics were evaluated in 24 asthmatic children and adolescents, ages between 7 and 21 years, by quasi-static pressure-volume curves and by the static recoil-lung conductance relationship. The measurements were obtained by the step-wise inflation technique and the pressure-volume curves were analyzed by a new sigmoid exponential curve-fitting model of the form: VL = Vm + [VM/(1 + be-K . PstL)], where VL is lung volume, PstL is static recoil pressure, VM and Vm are the upper and lower asymptotes, and K and b are shape constants. The shape constant K serves as index for lung distensibility, whereas the slope of theta of the static recoil-lung conductance plot represents the flow-resistive behavior of the airways. The combined evaluation of these two parameters (K and theta) shows that some asthmatic children have a very high lung distensibility and normal airway function, whereas others have nearly normal lung elasticity but grossly reduced airway distensibility. Sigmoid exponential analysis of static pressure-volume curves and an evaluation of the static recoil-lung conductance relationship in asthmatic children enable a distinction of these two types of functional derangements. Increased pulmonary distensibility consistent with an increase of alveolar air space seems to indicate an involvement of tissue elements. In contrast, decreased airway distensibility indicates a defect in the conducting airways. Sympathomimetics not only have a positive effect on airway mechanics, but seem to increase lung distensibility both in patients with hyperinflation and to an even greater degree in patients whose lungs are already too compliant.

Adolescent↗
PubMed1984

Calcium binding to the "stone protein" isolated from pancreatic stones of patients with chronic calcified pancreatitis.

Calcium binding to a new secretory protein present in all layers of human pancreatic stones has been studied. This protein with a molecular mass of 13,500 Da has about 4 equivalent binding sites for calcium. Maximum calcium binding was independent of pH and temperature, but the affinity of calcium to this protein increased with decreasing pH and increasing temperature, revealing maximum affinity at pH 7.3 and 37 degrees C. It is concluded that the calcium affinity could explain the presence of the protein in all layers of human pancreatic stones.

Amino Acids↗
PubMed1984

Long-term cimetidine in children with cystic fibrosis: a randomized double-blind study.

A prospective, randomized double-blind study of 38 children with cystic fibrosis (CF) was designed to evaluate the effectiveness of cimetidine in improving fat absorption and clinical condition. The treatment consisted of cimetidine or placebo, 600 mg/m2 body surface/day, over a 4-mo period. Clinical state, weight, height, skinfold thickness, lung function tests, para-aminobenzoic acid (PABA) peptide test, and plasma lipid and lipoprotein determinations were performed before and after the treatment period. Compared with age-matched healthy children, patients showed decreased cholesterol (150.2 +/- 31.2 mg/dl, mean +/- SD), decreased high density lipoprotein cholesterol (44.1 +/- 11.8 mg/dl), and decreased low density lipoprotein cholesterol (84.1 +/- 25.5 mg/dl) whereas the triglycerides and the very low density lipoprotein triglycerides were slightly elevated (118.2 +/- 33.0 mg/dl and 60.5 +/- 17.5 mg/dl, respectively). Apoprotein B and AI were slightly reduced and Apoprotein AII was in the normal range. After the 4-mo treatment no significant change in clinical condition, weight, or lipoprotein patterns could be detected between the two groups. The total PABA recovery in urine also did not change significantly (36.6 +/- 19.4% of the dosage given before versus 28.7 +/- 12.9% after 4 mo in the cimetidine group). Cimetidine gave rise to bronchoconstriction as shown by an increase in airway resistance (mean increase 14.8%) whereas the placebo group had a decreased Raw with a mean of 8.3%. Patients with CF have a dyslipoproteinemia that was not influenced by cimetidine. We conclude that cimetidine does not improve fat absorption and has, therefore, no place and no benefit in the treatment of children with CF.

Adolescent↗
PubMed1983

Elastic behavior of the lungs in healthy children determined by means of an exponential function.

In order to evaluate the elastic properties of the lungs in children, a new exponential sigmoid curve fitting model was developed with the function VL = Vm + (Vm/1 + b X e-K X Pst), where VL is the lung volume, Pst the static recoil pressure, VM and Vm the upper and the lower asymptotes (limits of lung volume) and K and b are specific constants. Pressure-volume (PV) data obtained from tidal breathing cycles at different inflation and deflation levels from functional residual capacity (FRC) up to approximately 90% total lung capacity (TLC) in 16 healthy children have been evaluated by this model. K in relation to age, calculated by the least square nonlinear regression analysis decreased during childhood, whereas in b increased. It seems that K (a volume-independent index of compliance and alveolar distensibility) is influenced by the increasing number of elastic fiber bundles, changes in the surface/volume ratio and finally by changes in the composition of the surfactant. It can be seen that this model is not only restricted to higher lung volumes, the lower limb of the S-shaped curve is also represented.

Adolescent↗
PubMed1983

Reversibility of lung function abnormalities in children with perennial asthma.

Extrinsic perennial bronchial asthma was studied by whole-body plethysmography in 118 patients to evaluate the degree and character of functional abnormalities during the asymptomatic "interval phase" of the disease. Study patients were divided into three functional subgroups, and the efficacy of albuterol (salbutamol), a beta-2-sympathomimetic drug, on bronchial obstruction of hyperinflation was analyzed. Response to medication was best in the group with predominant bronchial obstruction without hyperinflation. In contrast, patients with hyperinflation in the presence or absence of bronchial obstruction had only partial reversibility of their pathophysiologic alterations. Hyperinflation usually causes only minor clinical symptoms but tends to develop into irreversible lung damage in the form of "loss of elastic recoil." We suggest that early diagnosis and strict medical management in patients with hyperinflation are mandatory.

Adolescent↗
PubMed1982

[Clinical forms and lung physiology changes in children with bronchial asthma].

The clinical findings, allergoimmunological results and lung function data of 208 asthmatic children (aged 4-18 years), admitted to the Pediatric Outpatient Department were investigated. In respect to the case history and the clinical findings the patients were divided into 5 etiopathogenetic groups including infectious asthma (6%), seasonal asthma (29%), exogenous perennial asthma (56%), intrinsic asthma (4%) and exercise-induced asthma (5%). All patients presented with increased airway resistance measured plethysmographically (Raw greater than 120% predicted) as indicator of bronchial hyperreactivity. On a functional basis patients with perennial asthma were subdivided into those with predominant hyperinflation (thoracic gas volume, TGV greater than 120% predicted), those with hyperinflation and airway obstruction (Raw greater than 120%), and those with airway obstruction without overinflation. By the method of circular statistics the influence of salbutamol, a beta-2-mimetic drug inhaled by pressurized aerosol, was studied to evaluate the reversibility of these functional abnormalities in the symptom free interval of disease. Response to therapy was best in the group with predominant airway obstruction without hyperinflation. In contrast, patients with airway obstruction and/or hyperinflation showed only partial reversibility of pathophysiological alterations. Hyperinflation usually causes only minor clinical symptoms but leads to the development of irreversible lung damage in the form of "loss of elastic recoil". Therefore, it is suggested that early diagnosis and strict medical management are mandatory in patients with hyperinflation.

Airway Resistance↗
PubMed1982

[Short term efficacy of inhaler beta2 agonists in childhood asthma (author's transl)].

An attempt was made to assess the relationship between the bronchodilator response of three beta2-agonists (fenoterol salbutamol and terbutaline) administered by a metered aerosol inhaler during 43 lung function measurements on 25 asthmatic children. At constant one minute intervals the changes in total pulmonary flow resistance (R1) and dynamic lung compliance (C1 dyn) were measured. The effect of the three bronchodilators on the mean decrease of R1 was similar and not significantly different. Since R1 may fail to detect peripheral airway obstruction, the efficiency of the three drugs was evaluated on the basis of changes on C1 dyn in two subpopulations, one without signs of overinflation and one with evident overinflation, as judged from the initial values of the functional residual capacities and the C1 dyn's. On the basis of this distinction it is suggested that fenoterol has its predominant effect on patients with overinflation of the lungs and increased C1 dyn probably due to a loss of elastic recoil. Salbutamol is more efficient in patients suffering from a "primary bronchial disease", Terbutaline is equally effective in both.

Adolescent↗
PubMed1981

[Clinical, biochemical and socio-medical problems in cystic fibrosis].

The major thrust of the worldwide effort on the disease entity cystic fibrosis is concerned with genetic, diagnostic and therapeutical questions and detection of the primary defect. The authors summarize new aspects presented at the VIIIth International Congress on Cystic Fibrosis in Toronto, Canada, 1980. Their aim is to inform about present knowledge on prenatal diagnosis and neonatal screening, to review clinical problems in the management of children with cystic fibrosis and, finally, discuss the future problems of adolescent and adult cystic fibrosis patients.

4-Aminobenzoic Acid↗