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Biomedical subjects

C Baumgarten

Publications and source records attributed to C Baumgarten.

17 recordsLinked to original sources
PubMed1992

Effects of converting enzyme inhibition on endothelial bradykinin metabolism and endothelium-dependent vascular relaxation.

The effects of ACE-inhibitors on bradykinin metabolism and bradykinin-induced endothelium-dependent relaxation were studied in isolated coronary arteries and endothelial cells in culture. The results suggest that ACE-inhibitors affect coronary vascular tone by at least two endothelium-dependent and bradykinin-mediated mechanisms: First, ACE-inhibitors decrease endothelial bradykinin degredation which is accompanied by an augmented bradykinin mediated endothelium-dependent relaxation. Second, ACE-inhibitors evoke endothelium-dependent relaxations in coronary arteries stimulated with threshold concentrations of bradykinin, which cannot be attributed to an inhibition of bradykinin degradation. The effect appears to represent a new mechanism which may be based on an interaction of the bradykinin receptor and the angiotensin converting enzyme on the cellular level.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Plasma exudation as a first line respiratory mucosal defence.

A great variety of provocations of the airway mucosa produce extravasation of plasma from the abundant subepithelial microvessels. A plasma exudate has important actions through its volume, its specific and unspecific binding proteins, its enzyme systems, and its potent peptides (of kinin, complement, coagulation, fibrinolysis and other systems). If allowed to operate on the surface of an intact mucosa the plasma exudate would have important roles in normal airway defence. Recent observations in guinea-pig tracheobronchial airways and in human nasal airways suggest that the mucosal exudation of plasma into the airway lumen is a non-injurious fully reversible process. Threshold exudative responses thus resulted in the appearance of an 'unfiltered' plasma exudate not only in the lamina propria but also on the surface of an undisrupted mucosa. Even after extensive luminal entry of exudate the epithelial lining was intact, as judged by light, fluorescence and electron microscopy. Hence, the epithelial barrier was reversibly permeable when approached from beneath by the plasma exudate. This was a distinct increase in outward permeability, because even during the exudation of plasma the mucosa remained a barrier to luminal solutes. It is possible that the exudate itself, by a slight compressive action on the basolateral aspect of epithelial cells, creates intercellular pathways for its entry into the lumen. Contrary to current beliefs, we propose that plasma exudation should be considered a first line respiratory defence mechanism operating together with other systems of the mucosal surface.

Absorption↗
PubMed1991

Suppressive effect of loratadine on allergen-induced histamine release in the nose.

It has been speculated whether the recently developed non-sedating antihistamines may possess other properties than merely being antagonists at the H1-receptors. To investigate this suggestion 12 patients with strictly seasonal allergic rhinitis participated in a double-blind placebo controlled randomized cross-over study outside the pollen season. At steady state levels of 10 mg loratadine, a new non-sedating antihistamine, the patients were challenged with methacholine. This was followed by a nasal challenge with increasing doses of allergen. 24 h later the patients were rechallenged nasally with the same methacholine dose as the day before. The volume of the methacholine-induced nasal secretion was measured and the response to allergen was determined by scoring technique. In returned nasal lavage fluid the levels of histamine and TAME-esterase activity were measured. It was found that loratadine significantly reduced the immediate allergic nasal symptoms compared with placebo (P less than 0.01). Loratadine also reduced the allergen-induced release of histamine into the nasal cavity after the strongest allergen dose, from 9.6 +/- 1.5 (mean +/- SEM) to 6.4 +/- 1.4 ng/ml (P less than 0.05). A similar decrease in the TAME-esterase activity after treatment with loratadine was observed. The TAME-esterase activity decreased from 11.6 *10(3) +/- 2.47 *10(3) to 5.60 *10(3) +/- 1.45 *10(3) CMP (P less than 0.05). There were no significant changes between the active and placebo treatments regarding the methacholine-induced secretory response. This was true for the initial methacholine challenge as well as the secretory response 24 h later.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Presence of vasoactive intestinal peptide receptors in nasal mucosa.

In recent years several tachykinins have been identified in the airway sensory nerves. Since the physiological and pathophysiological effects of neuropeptides depend on their functionally relevant concentrations and presence of specific receptors in the target tissue, specimens of enlarged turbinates and nasal polyps were removed in 11 patients and examined for the presence of vasoactive intestinal peptide (VIP) receptors. An intensive color reaction was observed in the cytoplasm of the tubular mucosa cells in polyps and turbinates as well as in the epithelium and submucosal glands. Since both these tissues reacted with VIP receptor antibody, noncross-reacting antibody against dendritic reticular cells (DRC 6-B7), nonspecific binding is possible, however it also must be speculated that the unspecific binding is overlaying specific binding. In addition a large number of cells located diffusely or in close association in the subepithelium and interstitial tissue stained only with VIP-specific antibody, indicating specific receptor binding. The color reaction is limited to the cell membrane and the cytoplasm of these cells was clearly eosinophilic. These cells were located in close proximity of the blood vessels, very indicative for active migration. Since VIP-positive nerves are also located near the blood vessels an activation process of these cells with subsequent release of enzymes and other active proteins is possible, thus influencing the inflammatory response.

Adult↗
PubMed1991

The possible role of substance P in the allergic reaction, based on two different provocation models.

It was shown in two different provocation models (nasal and bronchial provocation) that substance P (SP) may play an important role in the neurogenic inflammatory response in upper and lower airway disease. (1) Pretreatment with SP augments the antigen challenge response of the nasal mucosa. (2) The baseline bronchoalveolar lavage (BAL) concentrations of SP are elevated 8-fold in allergies (pollen asthma) as compared with normals, even outside of season. (3) The SP concentration in BAL increases significantly (p less than 0.05) after bronchial allergen provocation. These findings support a previous hypothesis of an abnormally elevated activity of nonadrenergic-noncholinergic excitatory nerves and are in accordance with the results of a decreased activity of neutral endopeptidase exaggerating neurogenic inflammatory responses in the airways, including bronchomotor tone hyperresponsiveness.

Adult↗
PubMed1978

The significance of nasal protease inhibitor concentrations in house dust allergy.

In 57 patients with house dust allergy and 20 controls protease inhibitor concentrations in nasal secretions were measured before and after antigen challenge. A correlation was found between low inhibitor levels and long duration of disease. Furthermore, significant differences of inhibitor concentrations could be demonstrated between patients with strong or moderate reactions to antigen provocation, and between patients with isolated rhinitis or a combination of rhinitis and bronchial asthma. The clinical significance of the results will be discussed with special regard to different biochemical mechanisms in the pathophysiology of seasonal and perennial immediate-type rhinitis.

Adolescent↗
PubMed1976

Globin synthesis in uraemia.

Globin synthesis was measured by incubating washed packed red cells with a balanced amino acid mixture and 14C-Histidine. After globin had been isolated from the haemolysate the 14C-incorporation rate per 10 mg globin per min was estimated. With regard to globin synthesis no differences existed between patients on chronic intermittent haemodialysis therapy (n equals 41), patitents suffering from secondary anaemia due to chronic infection, rheumatism or malignant diseases (n equals 21) and healthy subjects (n equals 37). Patients with acute bleeding on the other hand, had significant higher 14C-incorporation rates caused by an increase of the reticulocyte count mu1 blood (n equals 13). When substances retained in renal failure were added to the incubation mixture a marked inhibition took place with guanidinosuccinic acid, methylguanidine and fraction containing peptides with a molecular weight between 1200-1400 present in uraemic serum and normal urine, but not in serum from patients without renal failure.

Amino Acids↗
PubMed1975

[Early postoperative diagnostic management by arterial-reobstruction after vascular operations using the ultrasonic flowmeter (author's transl)].

The Doppler ultrasonic method can confirm the success of the operation in the early post-operative phase after reconstructive vascular operations as an essential non-invasive technique or clear a doubtful improvement of the blood flow. Thus an arteriography can be indicated in good time. On the basis of reconstructive cases the usefulness and the advantageous application of the Doppler ultrasonic flowmeter in the operating theater is demonstrated.

Adolescent↗
PubMedDate not supplied

Recovery of pituitary-adrenal axis after withdrawal or reduction of systemic corticosteroids in patients with bronchial asthma.

In 36 patients with bronchial asthma a new inhalable corticosteroid (Fluocortin-butyl-ester) was administered to reduce systemic steroids and especially to study the recovery of pituitary-adrenal function. On the basis of the present results, it can be said that patients with the least degree of emphysema and obstruction and with good coughing dynamics and productive expectoration are most suitable for therapy with inhalable corticosteroids. If the systemic steroid reduction is adequate, the recovery phase of the pituitary-adrenocortical system begins after about 5 months and the response to ACTH appraoches normal values after about 8-9 months. About 4 mg prednisolone-equivalent per day can be assumed to be the systemically effective limiting dose. The reducibility as a percentage of the initial dose-regardless of its absolute value- and the maintenance dose achieved also appear to be of equal importance for the recovery of the functional reserve of the pituitary-adrenocortical system. No relationship to the duration of the disease and the initial steroid dose could be demonstrated. The clinical picture of the corticosteroid withdrawal syndrome is dependent on endogenous cortisol synthesis. The symptoms disappear spontaneously with increasing synthesis.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Semi-depot hyposensitization in severe hay fever: its clinical effectiveness and the therapeutic problems. (A four year study using intranasal challenge testing to monitor success).

Hyposensitization treatment for at least two years using pyridine-extracted alum precipitated (PEAP) extracts was carried out on 332 cases of severe hay fever, some of which were steroid dependent. Subjective self-assessment and weekly average use of additional medication were recorded, nasal challenge tests were conducted before and during treatment and related to the clinical picture. Successful treatment was unrelated to age, though distinctly limited where there was a history of more 15 years illness. It was however related to the pollen count from 1973 to 1976 and to the type and number of the antigens to which there was a clinical response. In spite of specific hyposensitization 4,2% of the pollinosis cases developed additional pollen asthma. In the course of treatment there were several instances of an enlargement of the individual antigen spectrum; sensitization to pollen, mould fungi, house dust and animal epithelia were recorded. In a total of 11,850 injections there were severe local reactions in 16,2% rhinoconjunctivitis in 1,6% asthma in 0,4% and urticaria in 0,4%. One female patient went into anaphylactic shock 12 hours after the administration of the antigen extract. In about 20% of the injections granulomas developed, about the size of a cherry-stone, which persisted for up to six months and which in some instances were reactivated by severe exposure to allergens. There was an unusually high percentage of organ and generalised reactions whenever the treatment was continued using a new antigen solution without reducing the dose.

Administration, Intranasal↗