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Biomedical subjects

X Baur

Publications and source records attributed to X Baur.

At least 289 records · Page 16Linked to original sources
PubMed1984

[Right ventricular hemodynamics and lung function following amrinone injection].

UNLABELLED: Amrinone is a positive inotropic agent which has been widely used for treatment of left heart failure. As this drug has a relaxing effect on smooth muscle cells, we considered that hemodynamics and ventilatory mechanics could be simultaneously improved in patients with right heart failure caused by obstructive lung disease. Swan-Ganz catheters were used in 11 patients. Following injection of 1.5 mg/kg Amrinone, cardiac output increased from 6.1 to 6.9 l/min (p less than 0.05). Stroke volume showed only a slight increase; pulmonary vascular resistance was reduced from 407 to 308 dynes . s . cm-5 (p less than 0.01). Body plethysmographic examination revealed a decrease of specific airway resistance from 33 to 24 cm H2O . s (p less than 0.01). CONCLUSION: In patients with right heart failure due to obstructive lung disease Amrinone application can result in an improvement in both hemodynamics and ventilatory mechanics.

Airway Resistance↗
PubMed1984

Acute airway obstruction followed by hypersensitivity pneumonitis in an isocyanate (MDI) worker.

A rare combination of an acute asthmatic reaction followed by hypersensitivity pneumonitis after exposure to diphenylmethane diisocyanate (MDI) is described. The patient, who was nonatopic and did not show bronchial hyperreactivity to metacholine, was occasionally engaged at the workplace in spraying a mixture of MDI and polyol to produce a polyurethane foam for use as a packing material. Challenge testing by MDI resulted first in a significant immediate bronchial obstruction indicated by decreases in specific airway conductance and forced expiratory volume at 1 s, and then in a significant decrease in vital capacity and diffusing capacity, associated with systemic reactions such as anorexia, malaise, fever, and leukocytosis three to eight hours after challenge. Challenge testing by toluene diisocyanate produced a mild systemic reaction. This finding, as well as the detection of specific IgG antibodies to various isocyanate-human serum albumin conjugates, suggests immunologic cross-reactivity between different isocyanates. Neither skin testing nor the radioallergosorbent test indicated a type I sensitization. After contact with isocyanates was terminated, the disease did not recur.

Acute Disease↗
PubMed1983

Inhibition of acetylcholinesterase by diisocyanates and its spontaneous reactivation.

The inhibition of human acetylcholinesterase (AchE) by 4,4'-diphenylmethane diisocyanate (MDI) is determined and compared with the previously described inhibition of this enzyme by two other industrially used diisocyanates: toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI). The inhibition potency of these three diisocyanates is found to be in the oder HDI greater than TDI greater than MDI. The spontaneous reactivation of inhibited AchE is reanalysed with the help of a computer program designed to fit the reactivation data to the exponential rate equation Vt = Vinf (1 - e-Kobs X (t - to) ). The enzyme inhibited by HDI and MDI undergoes very slow and limited spontaneous reactivation. The rate of delivery of diisocyanates into the respiratory tract of an exposed worker may be faster than the rate of spontaneous reactivation of the inhibited enzyme. These results are discussed in connection with the obstructive lung disease observed in approximately 5% of the workers employed in the isocyanate industry.

Acetylcholinesterase↗
PubMed1983

Immunologic cross-reactivity between different albumin-bound isocyanates.

Sera of six workers with conclusive evidence for IgE-mediated sensitization to isocyanates were used for evaluation of immunologic cross-reactivities among eight different isocyanate-protein conjugates. In all cases RAST and/or skin-test investigations revealed the presence of IgE antibodies reacting specifically with HSA conjugated with those isocyanates to which workers were exposed as well as with other isocyanates with which they had not been in contact. By the RAST inhibition technique, moderate to strong mutual cross-reactivities between all tested isocyanate-HSA conjugates--even between aromatic and aliphatic ones--could be demonstrated in tests with five sera. The magnitudes of cross-reactivities differed, however, from one patient to another. One serum contained IgE antibodies that were almost completely specific to TDI-HSA; with this serum only weak cross-reactivities with other isocyanate conjugates could be demonstrated. These results indicate the predominance of closely related antigenic determinants in HSA conjugated with different isocyanates. The common antibody-binding regions are obviously recognized to different extents by antibodies of clinically sensitized workers, indicating individual differences in specificities and avidities of antibody populations. Nearly complete lack of IgE binding of ovalbumin-bound TDI in RAST and RAST inhibition indicates carrier-specific antigenicity of isocyanate-protein conjugates. In addition, since unmodified HSA did not bind IgE, antigenic determinants of the conjugates studied should be predominantly formed by the isocyanate-protein bond regions and concurrently by neighboring amino acid residues of the HSA molecule.

Adult↗
PubMed1983

Common antigenic determinants of haemoglobin as basis of immunological cross-reactivity between chironomid species (Diptera, Chironomidae): studies with human and animal sera.

Chironomids, of which approximately 10,000 species exist, are reported to cause severe immediate type allergic diseases in man. In the present study, immunological cross-reactivity between 14 chironomid species from different continents was proven by RAST inhibition, double immunodiffusion and a new allergoprint technique, based upon PAGE separation of insect crude extracts. Using isolated chironomid haemoglobins and sera of sensitized persons, as well as rabbit antibodies against larval crude extract or against the haemoglobin fraction of Chironomus thummi, it could be proven that cross-reactivity derives at least predominantly from haemoglobin components with common antigenic determinants in the different species.

Animals↗
PubMed1983

Inhibition of acetylcholinesterase from human erythrocytes by isocyanates.

Four isocyanates, two of which are widely used in industry, were found to be potent inhibitors of acetylcholinesterase from human erythrocytes. Aliphatic isocyanates are stronger inhibitors of the enzyme than are aromatic isocyanates. Incubation at 21 to 23 degrees C for several days leads to slow and limited spontaneous reactivation of the inhibited enzyme. This enzyme inhibition may be a contributing factor in the induction of respiratory disease observed in about 5% of workers exposed to isocyanate vapors.

Acetylcholinesterase↗
PubMed1982

Clinical symptoms and results of skin test, RAST and bronchial provocation test in thirty-three papain workers: evidence for strong immunogenic potency and clinically relevant 'proteolytic effects of airborne papain'.

Seventeen out of thirty-three workers who have been exposed to airborne papain at their place of work regularly developed asthmatic symptoms such as shortness of breath, wheezing, coughing, sneezing, rhinorrhea and conjunctival irritation upon contact with this proteolytic enzyme. Investigations by RAST, skin test and bronchial provocation test proved IgE-mediated hypersensitivity to papain in fourteen symptomatic workers. Ten of these were in a screening investigation involving twenty-nine of the thirty-three workers; i.e. the incidence of IgE-mediated sensitization was 34.5% of this group. Bronchial provocation of as little as 0.001--0.5 mg of papain was shown to elicit immediate or dual asthmatic reactions in all eight tested workers with RAST values greater than 3 u/ml. On the other hand, inhalation of 0.5 mg of papain did not cause any remarkable change in non-exposed asthmatics. Occupation-related blood-stained nasal secretions and/or cutaneous flare reactions in all four heavily-exposed papain workers, of whom three had negative skin test and RAST results, suggest a direct effect of the proteolytically active enzyme on human tissue. There was a significant elevation (P less than 0.001) of serum trypsin inhibitory capacity in papain workers which seems to depend on the degree of exposure. No significant differences between symptomatic and asymptomatic workers in alpha 1-antitrypsin (Pi) phenotype subtypes were found.

Adult↗
PubMed1982

Studies on antigens useful for detection of IgE antibodies in isocyanate-sensitized workers.

Toluene diisocyanate was conjugated by two different methods to human serum albumin. These conjugates were used as antigens in the radio-allergo-sorbent-test (RAST) for detection of IgE antibodies in sera of isocyanate-sensitized persons. Chemical analyses have shown that conjugates containing 18-28 mol of isocyanate residues per mol protein were more potent antigens than those containing greater amounts of isocyanate residues. These results were confirmed by RAST inhibition experiments. The importance of optimization of the immunoradiometric methods for study of immunologic sensitization to isocyanates is discussed.

Antibodies↗
PubMed1981

[Bronchial asthma induced by exercise (author's transl)].

Both anticholinergic drugs and mast-cell stabilizing cromoglycate had a protective effect in 12 patients with exercise-induced bronchial asthma. beta 2-Sympathomimetic drugs provided the most reliable means of prevention and cure. They prevented the asthmatic reaction in all 12 patients, while in a further 23 they provided highly significant decrease in airway resistance after severe bronchial obstruction had set in.

Airway Resistance↗
PubMed1981

Follow-up on angiotensin-converting enzyme in serum of patients with sarcoidosis.

Fluorimetrically measured serum angiotensin-converting enzyme (ACE) activity was found to be significantly elevated (p less than 0.001) in 31 untreated patients with sarcoidosis in comparison to 38 healthy controls, 20 corticosteroid-treated patients with sarcoidosis, 15 subjects with resolved sarcoidosis and 100 patients with other lung diseases. ACE values more than 2 SD above the control mean value were seen in 68% of untreated patients with sarcoidosis, but only in 5% of healthy controls, 7% of patients with tuberculosis, 0% of patients with lung tumors, 9% of patients with bronchial asthma or chronic obstructive pulmonary disease and in 17% of patients with pulmonary fibrosis due to hypersensitivity pneumonitis or diffuse idiopathic fibrosis. Resolution of sarcoidosis, spontaneously or induced by corticosteroid therapy, was accompanied by normalization of serum ACE activity in 18 out of 19 cases. In 7 out of 9 patients without clear-cut clinical improvement, changes of serum activity of ACE were not substantiated. Relapse of sarcoidosis seen in 1 case qas associated with a significant increase in ACE levels. Our results suggest that longitudinal studies of serum ACE activity are valuable in assessing the current activity and the course of sarcoidosis. Furthermore, they may contribute to restriction of necessary operative diagnostic procedures.

Adrenal Cortex Hormones↗