Search PubMed⌕ Search

Biomedical subjects

H W Baenkler

Publications and source records attributed to H W Baenkler.

At least 19 recordsLinked to original sources
PubMed1999

Dynamics of eicosanoids in peripheral blood cells during bronchial provocation in aspirin-intolerant asthmatics.

The underlying mechanisms of bronchoconstriction in aspirin-intolerant asthmatics (AIAs) are still unknown, but the hypothesis of an altered metabolism of arachidonic acid is generally accepted. So far, no in vitro test for aspirin intolerance is available. The hypothesis that the profile of eicosanoid mediators is changed in AIA-even before aspirin challenge was tested. The release of prostaglandin E2 (PGE2), peptidoleukotrienes and histamine was measured using competitive enzyme immunoassays in 10 asthmatics with a history of aspirin intolerance, 10 controls and eight aspirin-tolerant asthmatics (ATAs) before and after bronchial provocation with lysine-aspirin. Comparing basal release of eicosanoids before challenge, peptidoleukotrienes were significantly elevated and PGE2 was vastly reduced in AIAs, whereas ATAs had elevated basal peptidoleukotrienes but only slightly reduced basal PGE2. The decrease in forced expiratory volume in one second (FEV1) was not associated with changes in histamine release. After aspirin challenge, there was a massive increase of already elevated peptidoleukotrienes in AIAs, but not in ATAs. Arachidonic acid-induced PGE2 release in AIAs was not significantly changed, whereas it was significantly reduced in ATAs and healthy controls. Histamine release was unaffected by aspirin challenge in all three groups. There is a typically altered profile of eicosanoids in aspirin-intolerant asthmatics which could make in vitro diagnosis of aspirin intolerance possible.

Adult↗
PubMed1996

Effect of prostaglandin E2 on eicosanoid release by human bronchial biopsy specimens from normal and inflamed mucosa.

BACKGROUND: Eicosanoids such as prostaglandin E2 (PGE2), thromboxane A2 (TXA2), and peptidoleukotrienes (pLT) are known to be biologically highly active lipid mediators, especially in human lung epithelium. PGE2 is thought to have mostly bronchoprotective effects, whereas pLT and TXA2 are bronchoconstrictive. This study was undertaken to assess the release and interaction of eicosanoids in human bronchial biopsy specimens of normal and inflamed mucosa. METHODS: Bronchial biopsy specimens were obtained from 16 patients, seven controls without signs of inflammation and nine patients with severe inflammatory processes in the epithelium. The release of pLT, TXA2 (measured as TXB2), and PGE2 was investigated using a "functional in vitro test" and the addition of several stimuli. RESULTS: Specimens incubated with arachidonic acid released higher amounts of pLT, TXB2, and PGE2 than unstimulated specimens. Preincubation with PGE2 revealed significant inhibition of arachidonic acid-induced release of pLT and TXB2 (> 50%). The inhibitory effect was higher in normal than in inflamed epithelium. CONCLUSIONS: Exogenous PGE2 has inhibitory effects on the release of pLT and TXB2 in human bronchial biopsy specimens. This finding could explain the bronchoprotective effect of inhaled PGE2 in normal subjects and asthmatic subjects as direct eicosanoid interactions. It also supports the concept of PGE2 as a bronchoprotective endogenous substance. The complex effects of PGE2 as a modulating mediator in inflammation may be worth investigating.

Adult↗
PubMed1996

Eicosanoids from biopsy of normal and polypous nasal mucosa.

In order to clarify the influence of inflammatory mediators of the arachidonic acid cascade in the mechanism of nasal polyp growth, peptido-leukotriene (pLT), prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) synthesis was investigated. In addition to several stimuli, functionally intact human biopsy specimens of polypous and normal tissue were incubated. Especially remarkable was the significantly increased release of pLT by polypous tissue upon arachidonic acid stimulation, in contrast to only slightly elevated PGE2 release compared to normal tissue. Basic release of pLT and PGE2 was similar for polypous and normal tissue. Examining TXB2 release, no significant difference was observed with regard to the origin of tissues. These data support an altered pattern of the lipoxygenase and cyclo-oxygenase pathways when tissue becomes irritated and suggest their involvement in the aetiopathogenesis of nasal polyps.

Biopsy↗
PubMed1995

Mucosal histamine content and histamine secretion in Crohn's disease, ulcerative colitis and allergic enteropathy.

Histamine exhibits various biological effects in inflammatory and immunological reactions. To further define its potential role in allergic enteropathy and inflammatory bowel disease, both gut mucosal histamine levels and histamine release from endoscopic biopsy samples were measured. Tissue histamine content resulted from addition of the released amount of histamine and the remaining part of tissue histamine. The results demonstrate highly elevated mucosal histamine levels of the large intestine in allergic enteropathy. In inflammatory bowel disease histamine content and secretion were found to be significantly increased particularly in affected mucosa of Crohn's disease and ulcerative colitis than in unaffected tissue or in healthy controls. These findings give strong evidence that mast cell mediators like histamine play a role in the pathogenesis of these diseases. Mucosal histamine is thus concluded to contribute to the immuno-inflammatory reactions of the intestine found in these disease states and to reflect the degree of colonic inflammation in Crohn's disease and ulcerative colitis.

Biopsy↗
PubMed1991

[Allergic enteropathy. Intestinally-mediated fungus allergy].

This article reports on a 53-year-old woman suffering from recurrent diarrhea since 1980 who, in November 1988, was admitted to the Medical Department of the University of Erlangen-Nuremberg with four to eight loose to liquid stools a day. Since January 1988, in addition to abdominal symptoms, including meteorism and recurrent abdominal pain, intermittent bouts of fever of up to 40 degrees C lasting six to eight hours and frequently occurring in the evening, had been noted. The patient's symptoms improved at weekends and during the holidays. Since 1977, she had been employed at a cheese counter, selling cheese. Noteworthy findings were an eosinophilia of 6% and, with the prick skin test, weakly positive reactions induced by two moulds with no increased total IgE and negative IgE RAST for diverse foods and moulds. An in vitro histamine-releasing test performed on colonic mucosal particles obtained at colonoscopy, a sensitization of the mucosa to moulds was demonstrated, and the patient was then given the mast cell stabilizing agent DNCG. This treatment cleared the symptoms, and she put on weight. In vitro tests on colonic biopsy material repeated in 1989 revealed a significant reduction in the release of histamine in response to the anti-allergic treatment.

Cladosporium↗
PubMed1990

ASA-induced release of histamine from nasal mucous membranes in analgesic intolerance and polyposis nasi.

Tissue samples from the polypous mucous membrane and the inferior nasal concha were taken from 13 patients with polyposis nasi and from 12 other patients with an additional intolerance to analgesics. The tissue of the inferior nasal concha from patients without polyposis nasi served as a control. The relative histamine content of the samples (in ng/mg dry weight) and the relative histamine release (in %) after addition of acetylsalicylic acid (ASA) were determined. A significantly higher relative histamine content in the tissue samples of polyp patients without an intolerance to analgesics was seen in comparison to the other two groups. The relative histamine release of both patient groups with nasal polyposis was comparable. The control group exhibited both an increased spontaneous release of histamine as well as a higher relative histamine release from the tissue of the inferior nasal concha.

Adult↗
PubMed1989

[Functional classification of allergic diseases].

Allergology is the oldest branch of clinical immunology. Allergic reactions are subject to the laws of all immune reactions from the antigen presentation to the effector mechanisms. Coombs' and Gell's classical four types of allergy should and could therefore now be expanded by a functional classification oriented towards the T- or B-lymphocytes and the immunoglobulins involved in the pathogenesis.

Allergens↗
PubMed1989

Kinetics of histamine released from rectal mucosa.

This kinetic study was performed to investigate the different tissue-influencing histamine amounts in Crohn's Disease (CD), Ulcerative Colitis (UC), patients with polyps and cancers (P.a.C.Gr) and in a Control Group (CG). For this purpose the endoscopically obtained specimens from rectal mucosa were immediately placed into 1000 microliters of Hank's incubation medium in order to determine the spontaneously released histamine amounts at the time points of 5, 10, 15, 20 and 30 minutes. Each time a volume of 100 microliters was removed from the incubation medium and the kinetic value (KV) was detected by using the single isotope radioenzymatic method. Influencing of natural histamine catabolism and the comparison of the tissue histamine release with or without air oxygen in the incubation medium using four kinetic programmes (KP1-4) provides clearly different KVs, not only between the KPs but also within the same KP. The P.a.C.Gr. shows higher kinetic values (KVs) compared with the CG. In KP1-3 the kinetic courses (KCs) of the Inflammatory Bowel Diseases (IBDs), CD and UC-both not yet divided in active (a.) or not active (n.a.) disease stages-cross the KCs of the CG several times. Only the differentiation of the IBDs in active and not active disease stages in KP4 reveals that CDa. and UCa. stand out from the CG by higher KVs, and in contrast, CDn.a. and UCn.a. have lower KVs than the CG. The released amounts of histamine in CDa. and UCa. are significantly higher than in CDn.a. and UCn.a.

Adult↗
PubMed1989

Histamine release from human colonic mucosa in response to anti-IgE.

Testing of tissue particles for mediator release may be very useful for the diagnosis of localized immunological abnormalities or allergies. The aim of this study was to set up a general procedure to test the reaction of large bowel mucosa to stimuli via the IgE-mediated pathway. Therefore, tissue particles from normal subjects and from patients suffering from different diseases (Crohn's disease, ulcerative colitis, intestinal polyps) obtained at routine coloscopy were exposed to either Hanks or anti-IgE solution to determine the spontaneous or the anti-IgE-induced histamine release, expressed as the percentage of the total histamine content of the biopsy. Histamine was measured using the single isotope radioenzymatic assay. In general, whereas anti-IgE interestingly reduced the histamine release compared to the spontaneous in most of the patients within the polyps group, there was a stimulating effect of anti-IgE throughout all other groups. Thus, the study confirms the possibility of performing functional tests using biopsy particles from the colon.

Antibodies, Anti-Idiotypic↗
PubMed1989

Antigen-induced histamine-release from duodenal biopsy in gastrointestinal food allergy.

Twenty-four patients allergic to food, which was demonstrated by oral provocation, were investigated. Six particles from duodenal mucosa were obtained during endoscopic examination and incubated with different foods. Specimens challenged by anti-human-IgE or without any stimulus served as control values. Also, skin tests and assays of specific IgE were performed. The spontaneous histamine release varied from 19% to 36%. Anti-IgE caused an increase up to 26% until 65%. Incubation with allergenic food induced a histamine release from 41% to 81%, demonstrating positive results in 27 out of 30 separate experiments. Antigen-induced histamine release from biopsy specimens turned out superior to skin tests and specific IgE. It is the most reliable tool for diagnosis of gastrointestinal food allergy besides oral provocation.

Adult↗
PubMed1988

Constant isotype pattern of anti-dsDNA antibodies in patients with systemic lupus erythematosus.

The isotype profile, particularly emphasizing IgG subclass distribution, of dsDNA antibodies in patients with systemic lupus erythematosus was evaluated using an especially adapted ELISA technique. Anti-dsDNA antibodies were quantified with class-specific antisera and subclass-specific monoclonal antibodies. IgG subclass specificity was proven with 20 myeloma proteins differing in light chains and allotypes. The standardization with myeloma proteins proved to be useful and reliable. Results from more than 100 anti-dsDNA positive sera from SLE patients showed specific antibodies within the three subclasses (IgG1: 52-100%, IgG2: 0-39%, IgG3: 0-48%). IgG4 was not detected in significant amounts. No correlation to the subclass distribution of total IgG was found. Each patients' serum displayed an individual isotype pattern that remained constant in longitudinal studies, independent of anti-dsDNA titre fluctuations. These results suggest a stable population of autoreactive clones in the progress of the disease.

Antibodies, Antinuclear↗
PubMed1987

Biopsy histamine in ulcerative colitis and Crohn's disease.

The histamine content of biopsy specimens obtained from patients with ulcerative colitis (UC), Crohn's disease (CD), or polyps was measured in vitro. This was done using colonic and rectal mucosa taken from affected and healthy tissue. In general, the results demonstrate a significantly higher histamine content in patients with UC. This was true with respect to colonic as well as rectal mucosa. Moreover, affected mucosa contained significantly more histamine than normal in UC and in CD. The histamine content of colonic and rectal mucosa was similar within each patient group. However, specimens from patients with UC again contained significantly more histamine than did those of patients with CD. The data underscore a distinct pathomechanism in UC and in CD. Therefore, determination of the histamine content of biopsy specimens may be an adjuvant criterion for the discrimination of different inflammatory bowel diseases.

Adult↗