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Biomedical subjects

K Sertl

Publications and source records attributed to K Sertl.

At least 37 records · Page 2Linked to original sources

Risk factors for sensitization to furred pets.

The risk factors for sensitization to pets was investigated in 169 male pupils. A recent or former contact with cats, dogs, and guinea pigs in own home was reported in 52 (30.8%), 42 (24.9%), and 20 (11.8%) study subjects, respectively. Clinically manifested allergy was found in two probands to cats and in two others to guinea pigs, three of them had formerly had pets and one proband with allergic rhinitis to cats had never had any pet. Sensitization to animals and aeroallergens was investigated with Phadezym-RAST. Only owners of cats had a higher incidence of cat sensitization than probands without direct contact (26.9% versus 10.3%, P less than 0.01). No statistically significant difference in sensitization to dogs and guinea pigs was found in groups with and without these pets. A strong correlation existed between sensitization to pets and other aeroallergens (house dust mite: P less than 0.025, birch pollen: P less than 0.0001, mugwort: P less than 0.0001, and grass pollens: P less than 0.0001). No association was found between sensitization to pets and smoking history, bronchial hyperreactivity to methacholine or radiological findings of the paranasal sinus.

Adolescent↗

Invasive pulmonary aspergillosis: evaluation with MR imaging.

Eleven patients with suspected invasive pulmonary aspergillosis underwent magnetic resonance (MR) imaging. Images were obtained with standard spin-echo sequences and electrocardiographic triggering before and after intravenous administration of gadolinium diethylenetriaminepentaacetic acid. Thirty-seven of 48 lesions seen on MR images were nodular infiltrates; 34 of these had a targetlike appearance, with hypointense centers and iso- or hyperintense rims. Twenty-three of 37 nodular lesions contained areas of hyperintensity on T1-weighted images. All 37 had enhanced rims on postcontrast MR images. The remaining 11 lesions were segmental infiltrates, seven of which were predominantly hyperintense on T1-weighted images. In one patient with nodular lesions, MR imaging findings were correlated with those from pathologic analysis of a resected upper lobe. Areas of hyperintensity corresponded to subacute hemorrhage permeated by Aspergillus organisms. The authors believe that the typical targetlike appearance of nodular lesions on MR images and the potential that MR imaging has to reveal hemorrhagic content will prove useful in the early diagnosis of invasive pulmonary aspergillosis.

Aspergillosis↗

Vasoactive intestinal peptide receptors in rat spleen and brain: a shared communication network.

The binding sites for [125I]-vasoactive intestinal polypeptide (125I-VIP) in rat spleen and brain were localized using autoradiography. High affinity VIP receptors are present in rat spleen, and competition studies reflect structure-activity relationship typical of VIP receptors elsewhere. In spleen, specific binding of 125I-VIP occurs on red pulp and, most abundantly, on the periarteriolar lymphoid sheath (PALS) of white pulp. Unlabeled VIP competes for binding to both red pulp and white pulp, whereas secretin displaces binding to PALS more potently than to red pulp. This indicates that expression of VIP and/or secretin type receptors is limited to T lymphocytes of white pulp. In red pulp, VIP receptor bearing cells probably are monocytes/macrophages since this is the most abundant red pulp cell type. In the brain, VIP receptors are widely distributed with the highest densities occurring in "sensory" areas. Receptors are abundant in the olfactory bulb, thalamic nuclei, several cranial nuclei and the area postrema. High levels of 125I-VIP binding occurred on inner walls of blood vessels of the brain and spleen. The distribution patterns of receptors for "VIP-ergic signals" in brain and lymphoid tissue indicate interrelatedness of the two organ systems. This may serve as one biochemical rationale for a bio-psycho-social view of health and disease.

Animals↗

Substance P: the relationship between receptor distribution in rat lung and the capacity of substance P to stimulate vascular permeability.

The interaction of substance P (SP) with specific receptors in intact lung tissue was autoradiographically visualized, using slide-mounted tissue sections of rat lung tissue. SP receptors are highly concentrated in the central airways and are not detectable in peripheral bronchi, vessels, and alveoli. Within central airways, receptor distribution is most concentrated in the epithelium and small vessels in the lamina propria. Smooth muscle in airway or blood vessel walls expressed no detectable SP receptors. Immunohistochemical staining for SP revealed SP-containing nerves in the same areas where the receptors are localized. Displacement curves of SP bound to rat lung indicated that the C-terminal fragment was much more effective than the N-terminal fragment at competing for SP binding. Injection of 0.3 to 30 nmol/kg SP dramatically increased vascular permeability in the trachea and to a lesser extent in the hilus. Peripheral lung failed to respond to SP with increased vascular permeability unless toxic concentrations of SP were employed. SP increased the transudation of protein into the trachea within 5 min of injection, and the extravasated protein persisted through at least 2 h. Both SP and SP(3-11) were capable of stimulating increased vascular permeability, but SP(1-4) was inactive. SP caused mast cell degranulation as reflected in increased plasma histamine levels after SP or SP(3-11) injection, but SP(1-4) had no effect. In order to determine if histamine release caused by SP contributed to the vascular permeability response, the effects of H1 and H2 antihistamine treatment were studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Passive sensitization and antigen challenge increase vascular permeability in rat airways.

Activation of mast cells in all organs in which this phenomenon has been studied leads to increased vascular permeability. Mucosal edema is thought to be an important component of the airflow obstruction of asthma. In order to develop a model to study IgE-mediated vascular permeability in lung, rats were passively sensitized with a murine monoclonal IgE-anti-dinitrophenyl (DNP). Forty-eight hours later, the animals were challenged intravenously with mouse serum albumin conjugated to DNP (1 to 25 micrograms) and received 125I-labeled bovine albumin at the same time to permit assessment of leakage of vascular proteins into the lungs. The animals became cyanotic, but they did not die. Control animals were challenged with mouse serum albumin alone and experienced no systemic reactions. The trachea, the hilum, and peripheral lung were removed and the radioactivity determined. Compared to control animals, vascular permeability was increased most impressively in the trachea and to a lesser extent in the hilum. No increased vascular permeability was found in the peripheral lung. In dose-response experiments (1 to 25 micrograms MSA-DNP injected), the peak effect in the trachea occurred at 25 micrograms MSA-DNP (+450 +/- 119% above control values, p less than or equal to 0.05), while the response in the bronchus was less dose dependent; maximal increase above control was at 12.5 micrograms DNP-MSA (+50 +/- 8%, p less than or equal to 0.05). The increased plasma exudation in the trachea and bronchi peaked within 5 min of antigen challenge and remained significantly increased for at least 2 h. After 8 h, no increased radioactivity could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Prevention of stress hemorrhage in an internal medicine intensive care station: sucralfate versus ranitidine].

Stress ulcer bleeding is a serious complication of critical illness and is associated with increased morbidity and mortality. For the prophylaxis of stress ulcers, antacids, H2-blockers, or sucralfate are prescribed. While H2-blockers inhibit the secretion of gastric acid, sucralfate appears to provide protection without reducing levels of gastric acid. Inhibition of acid secretion increases gastric pH, allowing bacterial overgrowth of the stomach by Gram negative bacteria, which colonize the pharynx and trachea and increase the risk of nosocomial pneumonia. For this reason, H2 blockers appear disadvantageous, though they offer adequate prophylaxis for stress ulcer bleeding. As it does not increase gastric pH, sucralfate provides adequate protection against Gram negative gastric overgrowth, however its prophylactic efficacy is not generally accepted. Therefore, we compared the H2-blocker ranitidine to sucralfate in the prophylactic treatment of stress ulcer bleeding and studied the incidence of positive bacteriological findings in the blood and bronchial secretions of the two groups. In a randomized study, 84 patients undergoing general intensive care received either ranitidine (6 x 50 to 6 x 100 mg daily i.v.) or sucralfate (6 x 1 g via gastric tube or per os). Both groups were comparable with respect to age, underlying disorders, and factors predisposing to the development of stress ulcers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

High-affinity substance P binding sites in rat esophagus plexus submucosus.

Substance P receptors were investigated in rat esophagus using 125I-Bolton-Hunter substance P as a labeling probe. Autoradiographic studies show that esophageal submucosa contains clusters of high-affinity substance P binding sites [maximum binding (Bmax) 4.2 +/- 0.28 fmol/mg protein; dissociation constant (Kd) 0.1 +/- 0.01 X 10(9) M]. The receptor distribution pattern is typical for submucous neurons. These data suggest that substance P may act as a neurotransmitter in rat esophagus.

Animals↗

Immunohistochemical localization of histamine-stimulated increases in cyclic GMP in guinea pig lung.

A significant number of asthmatic subjects are provoked by allergic reactions. The underlying pathophysiologic event is mast cell degranulation with the release and generation of the mediators of anaphylaxis. Histamine, one of the major mast cell mediators, causes 10- to 50-fold increases in guinea pig lung cyclic 3',5'-guanosine monophosphate (cyclic GMP) through H1 receptor stimulation. Employing monoclonal antibodies directed at cyclic GMP, immunocytochemical techniques were used to identify those specific cells in lung responding to histamine stimulation with increases in cyclic GMP. The most responsive cells were alveolar and parenchymal macrophages, pleural lining cells, and endothelial and epithelial cells. Little or no increases in bronchial or vascular smooth muscle cyclic GMP was noted. At the height of the reaction, a generalized increase in cyclic GMP staining of all alveolar cells was observed. These findings suggest that the lining cells of the lung including macrophages, mesothelial, endothelial, and epithelial cells may be the most responsive cells to histamine released during allergic responses. The absence of muscular staining suggests that cyclic GMP does not participate in histamine-stimulated muscle contraction.

Animals↗

Pirenzepin does not alter the pharmacokinetics of theophylline.

The possible pharmacokinetic interactions between pirenzepin and theophylline were investigated in an open single blind trial. Aminophylline (6.5 mg/kg body weight) was administered intravenously in five healthy male volunteers before and after chronic oral pirenzepin therapy (50 mg twice daily 5 days before to 2 days after giving aminophylline). To study the theophylline pharmacokinetics, serum and urine samples were collected up to 48 hours after aminophylline administration. It was demonstrated, that pirenzepin does not affect theophylline pharmacokinetics. Therefore, pirenzepin may be combined with aminophylline or theophylline without the risk of an interaction, which usually affect the coadministration of other antiulcer drugs, e.g. cimetidine, with theophylline.

Adult↗

Bombesin in human and guinea pig alveolar macrophages.

Bombesin found in neuroepithelial bodies and oat cell carcinoma of the lung, is thought to play an important role in normally developing and malignant lung. Monocytes-macrophages and human small cell lung carcinoma cells share several features, including macrophage-specific surface markers and the expression of functional receptors for bombesin-like neuropeptides and growth factors. Because small cell lung carcinoma cells synthesize immunoreactive bombesin, we investigated the possibility that alveolar macrophages also contain bombesin, a plausible hypothesis considering the many reports of neuropeptide production by immune cells and cells of bone marrow origin. Adherent human peripheral blood mononuclear cells as well as human and guinea pig alveolar macrophages were found to contain bombesin. The peptide was detected by radioimmunoassay, immunohistochemistry, high-pressure liquid chromatography with the use of different monospecific antibodies.

Acquired Immunodeficiency Syndrome↗

Effects of prednisolone on beta-adrenergic desensitization of normal peripheral lymphocytes: an in vitro model for steroid-controlled tachyphylaxis.

In vitro culture of human peripheral blood lymphocytes with the beta-adrenergic catecholamine isoproterenol for 24 hours, induced homologous beta-adrenergic desensitization, i.e. a large decrease in the number of beta-adrenergic binding sites and loss of the adenylate cyclase response to isoproterenol, without altering the effectiveness of prostaglandin E1 to stimulate the enzyme. Lymphocyte cultures pulsed for 24 hours with isoproterenol, washed free of the agent and cultured in hormone-free medium for 48 hours still showed marked suppression of the beta-adrenergic adenylate cyclase response and a lack of beta-receptors. When prednisolone was added to the isoproterenol-depleted resuspension medium of desensitized lymphocytes, however, the beta-adrenergic system recovered fully within 48 hours. Treatment of desensitized lymphocytes with prednisolone in the continuous presence of isoproterenol failed to restore beta-adrenergic responsiveness of the cells. The results are discussed with respect to the reconstituting effect of prednisolone on beta-adrenergic responsiveness in bronchial asthma after therapy induced tachyphylaxis.

Adenylyl Cyclases↗

Dendritic cells with antigen-presenting capability reside in airway epithelium, lung parenchyma, and visceral pleura.

In this study, we identified a population of dendritic cells (DC) that exists throughout human and mouse pulmonary tissues, including the trachea, bronchi, alveoli, and visceral pleura. In human tissue, these DC were shown to be positive for HLA-DR and T200 antigens. In the mouse, the DC expressed not only Ia and the T200 antigen, but also Fc-IgG and C3bi receptors. Unlike alveolar macrophages, the DC were negative for nonspecific esterase staining and shared ultrastructural similarities with the DC described by Steinman (1), and with Langerhans' cells, even though they did not contain Birbeck granules. We were able to demonstrate that mouse pulmonary DC function in antigen presentation, as observed with the other DC. Thus, the respiratory tract contains DC that are capable of functioning in antigen presentation and that may be important in pulmonary immune responses.

Animals↗

Substance P receptors in rat spleen: characterization and autoradiographic distribution.

The interaction of substance P with intact lymphatic tissue was quantified and autoradiographically visualized, using slide-mounted tissue sections of rat spleen. Radiolabeled substance P binds rapidly to an apparently single class of noninteracting high affinity sites (Kd = 2.4 nmol/L; Bmax = 9.4 fmol/mg protein). The ligand selectivity pattern suggests that substance P binding sites are similar to substance P receptors found in other tissues, including the brain, T lymphocytes, and macrophages. Substance P receptors are highly concentrated in the antigen-trapping spleen marginal zone, with low densities being found in the red pulp. No specific binding of radiolabel to T cell-dependent immunologic domains of the spleen is seen. The distribution of substance P receptors suggests that substance P is probably involved in the control of sensory functions of the immune system.

Animals↗

Acute effects of pirenzepin on bronchospasm.

The response to pirenzepin, a new acetylcholine receptor blocking agent, was assessed and compared to placebo in patients with reversible bronchoconstriction. A single intravenous injection of 20 mg of pirenzepin induced a significant reduction of airway resistance compared to placebo (p less than 0.05). The anticholinergic substance pirenzepin appears to be useful in the treatment of bronchospasm.

Aged↗

[Blood protein concentrations--are they parameters of disease activity in Crohn's disease?].

Concentrations of 19 different proteins were measured after hospital admission, before hospital discharge and 3 months thereafter in 40 patients suffering from an acute episode of Crohn's disease. Serum levels of acute phase proteins (alpha 1-glycoprotein, alpha 1-antichymotrypsin, alpha 1-antitrypsin, CRP, haptoglobin) and immunoglobulin M corresponded to the severity of inflammatory symptoms and correlated significantly with CDAI (Crohn's disease activity index). Albumin and transferrin were characteristic for nutritional status of the patient under basal conditions and during nutritional therapy. Prealbumin and retinol-binding protein behaved similarly, but results were not significant. The measurement of the proteins mentioned give valuable clues in regard to the course of the disease and therapeutic success in Crohn's disease.

Adolescent↗