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Biomedical subjects

V Im Hof

Publications and source records attributed to V Im Hof.

12 recordsLinked to original sources
PubMed1992

[Catheter embolization of the solitary pulmonary arteriovenous aneurysm].

Catheter embolization with coils was performed as a method of treatment in 3 patients with solitary pulmonary arteriovenous aneurysms (PAVA). This led to permanent occlusion of the PAVA in all cases. There were no complications following embolization. Bearing in mind that other workers also achieved good results by this method, embolization of a solitary PAVA by coils should be preferred to balloon embolization. Surgical treatment should only be carried out for a malformation which is not accessible to embolization or as part of a more complex procedure.

Adult↗
PubMed1992

[New aspects of asthma therapy].

Until recently, optimal bronchodilatation and in particular the inhalation of beta-agonists was considered the mainstay of asthma therapy. Steroids were added only in case of an unsatisfactory treatment effect. Recent epidemiological surveys, revealing an association between asthma mortality and the use of beta-agonists, and well controlled treatment studies suggest a change of concepts. Considering the long-term course of asthma, early suppression of asthmatic airway inflammation appears to be at least as important as an effective bronchodilatation. A prerequisite for a success of an individually taylored pharmacologic treatment is a comprehensive management of the disease, inclusive a continuous patient education.

Anti-Inflammatory Agents↗
PubMed1992

[Chronic cough].

Cough is a powerful physiological reflex mechanism that causes central airways to be cleared of foreign material and excess secretions. Chronic cough is a very common presenting symptom in general practice with a prevalence in the population of about 5%. As a general rule, persistent cough represents organic disease of the upper and lower airways, the lung parenchyma, the pulmonary circulation, the pleural space, the mediastinum and the upper gastro-intestinal tract. The most common cause is cigarette smoking, but virtually any chronic lung disease may be occasionally associated with cough. Complications of coughing are tussive syncopes, rib fractures, rupture of respiratory muscles and eventually hernias. Based on a detailed clinical history and physical examination, the investigation includes a chest radiograph, spirometry, and sputum smears. Radiography of the sinuses, bronchoscopy and upper gastro-intestinal endoscopy may be added. If the treatment of an underlying disease is successful, chronic cough may disappear. There are few 'antitussive' drugs with proven suppression of the cough reflex.

Antitussive Agents↗
PubMed1992

[Chronic bronchitis: rare etiology].

Chronic bronchitis is defined for epidemiologic and clinical purposes as the presence of productive cough for three months in each of two successive years. Based on symptoms, the term 'chronic bronchitis', therefore, does not describe one distinct disease. It is rather a collective name for the clinical manifestation of numerous different congenital or acquired chronic diseases of the trachea, the bronchi and the bronchioli. Cigarette smoking is the most consistently important (and preventable) determinant of chronic bronchitis. There are, however, other rare etiologic factors, including malformations, tumors, recurrent aspirations and bronchiectasis. The latter often occur in association with systemic disorders such as cystic fibrosis, immotile cilia syndrome, immunodeficiency, alpha 1-antitrypsin deficiency and others.

Bronchitis↗
PubMed1992

[Chronic asthmatic bronchitis].

Many patients with chronic obstructive pulmonary disease (COPD) episodically or continuously have asthmatic signs with a degree of reversibility in response to bronchodilators. In such cases, the diagnosis 'chronic asthmatic bronchitis' is often used, although the cause-effect relationship between COPD and asthmatic manifestations is not established. Hence, the 'chronic asthmatic bronchitis' is not a pathogenetic diagnosis, but rather a working diagnosis which implies a specific treatment of the reversible component of chronic airway obstruction. Certainly, the most important measure to avoid a rapid progression of COPD is the elimination of damaging agents by inhalation (smoking). In addition, it was a widely accepted belief that these patients require a continuous inhalation therapy with beta-agonists or anticholinergics. However, there is new evidence, indicating that a continuous treatment might accelerate the decline in ventilatory function and that a better long-term outcome might be achieved by on-demand inhalations.

Aged↗
PubMed1991

[Tuberculous pleuritis in pre-existent sarcoidosis].

The coexistence of the two granulomatous diseases sarcoidosis and tuberculosis in the same patient is rare and can raise diagnostic problems. We report a case of this kind in a 31-year-old man and discuss the diagnostic investigations, some of which can be misleading. In a patient with sarcoidosis and pleural effusion the possibility of tuberculosis must be ruled out, if necessary invasively.

Adult↗
PubMed1990

[Particle retention in the intrapulmonary conducting airways in hamsters].

Inhalation and the subsequent deposition, retention and clearance of particles play a pivotal role in pulmonary medicine. It has been widely accepted that inhaled insoluble particles which are deposited in the conducting airways are largely cleared within 24 hours by the mucociliary escalator. Recent reports, however, suggest that this view should be revised. We therefore investigated by light and electron microscopy the number and location of particles retained in the intrapulmonary conducting airways of hamsters as a function of time. The number of retained particles was estimated unbiasedly with a novel stereological method, the fractionator. Seven male Syrian Golden hamsters inhaled an aerosol of 6 microns polystyrene particles under controlled conditions. The lungs of 3 animals were fixed by intravascular perfusion 20 minutes after the inhalation, whereas those of the other 4 animals were fixed 24 hours later. Retained particles were found in all generations of the intrapulmonary conducting airways. They were submerged in the extracellular matrix in close contact with the epithelial cells between the cilia. The particles were coated by a thin layer of osmiophilic material which was interpreted as surfactant. In the lungs fixed immediately after the inhalation, 36% of the retained particles were ingested by macrophages. 24 hours after inhalation we still found 14% of the initially retained particles. 90% of these remaining particles were phagocytized. We conclude that: (1) Surfactant is important for the retention of particles in the intrapulmonary conducting airways of hamsters. (2) There is evidence for the existence of a resident population of very active airway macrophages which play a pivotal role in clearance of the retained particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1990

Surfactant displaces particles toward the epithelium in airways and alveoli.

This study was designed to investigate the early stages of particle deposition on airway and alveolar surfaces. To do this we used morphometric studies of aerosol deposition, in situ measurements of surface tension, and in vitro assays of particle displacement and mathematical modelling. We observed that latex particles, equal or less than 6 microns in diameter deposited in hamster lungs were submerged in the subphase of the alveolar lining layer and became completely coated with an osmiophilic film. Similar results were obtained for particles deposited in the conductive airways which were also covered with a surface active film, having a surface tension of 32 +/- 2 dyn.cm-1. In vitro experiments showed that pulmonary surfactant promotes the displacement of particles from air to the aqueous phase and that the extent of particle immersion depends on the surface tension of the surface active film. The lower the surface tension the greater is the immersion of the particles into the aqueous subphase. Mathematical analysis of the forces acting on a particle deposited on an air-fluid interface show that for small particles (less than 100 microns) the surface tension force is several orders of magnitude greater than forces related to gravity. Thus, even at the relatively high surface tension obtained in the airways (32 +/- 2 dyn.cm-1) particles will still be displaced into the aqueous subphase. Particles in peripheral airways and alveoli likely are below the surfactant film and submerged in the subphase. This may promote clearance by macrophages. In addition, particle displacement into the subphase is likely to increase the contact between the epithelial cell and particle. Toxic or allergenic particles would be available to interact with epithelial cells and this may be important in the pathophysiology of airway disease.

Administration, Inhalation↗
PubMed1990

Assessment of particle retention and clearance in the intrapulmonary conducting airways of hamster lungs with the fractionator.

A modified version of the fractionator was used to estimate the total number of polystyrene microspheres retained in the airways of hamster lungs at two different time points after inhalation. A systematic three-stage subsampling procedure with known sampling fractions was adopted. First, each lung was cut into slices, from which primary disectors were sampled systematically with a known sampling fraction. From each primary disector, smaller sub-disectors were subsampled, and the corresponding sampling fraction was estimated by point counting. Finally, a few particles were counted at the microscopic level in the sub-disectors, and the final estimate of total particle number (which is unbiased irrespective of any tissue deformations) was easily computed as a product of the counted number times the reciprocal of the successive sampling fractions. The error variance of each estimate was assessed from the data using a new estimator. An average of 6% of the deposited particles were retained on the epithelial surface of the intrapulmonary conducting airways shortly after the inhalation, from which at least one-third was already phagocytosed by macrophages. After 24 h, an average of 87% of the particles retained shortly after the inhalation had been cleared. The proportion of particles ingested by macrophages had increased to at least 87% in three out of four animals studied.

Animals↗
PubMed1990

Phagocytic properties and organelle motility of pulmonary macrophages from smokers and nonsmokers estimated in vitro by magnetometric means.

Monolayer cultures of pulmonary macrophages (PM) from 11 smokers (S) and 9 nonsmokers (NS) were incubated with submicrometric ferromagnetic Fe3O4 particles for one hour. After magnetization by an externally applied pulse magnetic field, the aligned Fe3O4 particles, located in the phagosomes and secondary lysosomes of the PM, emanated a remanent magnetic field which decayed with time. The initial field strength, B0, which is proportional to the amount of phagocytosed Fe3O4 particles, was 13.24 nT (SE 0.79 nT) in S and 11.74 nT (SE 1.39 nT) in NS. Ten nT correspond to roughly 4 micrograms Fe3O4. The initial rate of decay of the remanent field (during the first 60 s after magnetization), lambda 0, is proportional to the rate of particle misalignment. Therefore, lambda 0, is hypothesized to be an estimate of organelle motility. It was found to be the same in S and in NS, being 3.14 x 10(-3).s-1 (SE 0.18 x 10(-3).s-1) in S and 3.17 x 10(-3).s-1) (SE 0.22 x 10(-3).s-1) in NS. These results suggest that, in vitro, there is no difference in phagocytic activity and organelle motility in PM from S and NS.

Adult↗