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Biomedical subjects

A Oehling

Publications and source records attributed to A Oehling.

At least 19 recordsLinked to original sources
PubMed2002

Flow cytometric basophil activation test: a review.

Flow cytometry is a technique enabling the analysis of physical and biological characteristics of cells or other biological particles when labeled with antibodies coupled to fluorochromes or other dyes. The basophil activation test (BAT), also called flow-cytometric allergen stimulation test (FAST) [commercially available under the name of Flow CAST (Bühlmann Laboratories) or BASOTEST (Beckton-Dickinson)] is based on the in vitro allergen-induced specific activation of basophils. This assay rests on the demonstration of some membrane protein markers that appear after exposure to the allergen. This paper reviews some of the literature about the use of this technique in the investigation of immediate-type allergies to inhalant allergens, drugs, and foods, as well as our own experience with this diagnostic technique. Flow cytometry is a reliable method for the quantification of basophil activation after allergenic stimulus in vitro and in vivo. It also enables us to detect allergic and pseudoallergic reactions because of other mechanisms than allergen-specific IgE antibodies. Further clinical evaluation of this technique will allow validation and better establishment of its diagnostic value in allergy.

Adult↗
PubMed1999

Identification of a 36-kDa olive-pollen allergen by in vitro and in vivo studies.

BACKGROUND: Ole e 1 has been considered the major allergen of olive (Olea europaea) pollen. Some other relevant allergens (Ole e 2, 3, 4, and 6) have been recently described. This work aimed to study the IgE-binding frequency of a 36-kDa protein from O. europaea pollen in a large population of olive-allergic patients, its allergenic reactivity in vivo, and its presence in olive pollens of different origin, as well as in other relevant allergenic pollens. METHODS: Identification of IgE-binding components from O. europaea pollen extracts was elucidated by inhibition of SDS-PAGE immunoblotting using recombinant profilin (Ole e 2) and Ole e 1 molecules. The IgE-binding frequency of the 36-kDa protein was estimated by Western blot in a sample of 120 sera from olive-allergic patients. The cutaneous test with the 36-kDa protein was performed by intradermoreaction in allergic patients and control subjects. RESULTS: Exactly 83% of the sera from O. europaea-allergic patients recognized a protein with an apparent molecular weight of 36 kDa, under reducing conditions. It was detected by sera from monosensitized and polysensitized patients, showing a higher IgE frequency than the major allergen Ole e 1 (59%) and the minor profilin (Ole e 2) allergen (27%). Similar reactivity rates (79%) was found by intradermal test. Extracts from olive pollens collected in California presented a much higher amount (around 16-fold on average) of the 36-kDa protein than those from pollens of Spanish origin. The presence of similar allergens was detected only in closely related species (Syringa, Fraxinus, Ligustrum), and not in other common allergenic pollens. CONCLUSIONS: The 36-kDa protein constitutes a major allergen for olive-sensitized patients, but it is not equally represented in O. europaea pollens of different origins.

Allergens↗
PubMed1998

In vitro antigen-specific sulphidoleukotriene production in patients allergic to Dermatophagoides pteronyssinus.

BACKGROUND: Sulphidoleukotrienes (slt) are important mediators in allergic diseases that are synthesized after allergen-specific stimulation. OBJECTIVES: The aim of this study is to determine in vitro slt production after allergen-specific (Dermatophagoides pteronyssinus) stimulus of peripheral blood leucocytes and to observe whether histamine release in whole blood with the same allergen correlates with slt production. We also wanted to evaluate whether a correlation exists between the release of slt and histamine and other diagnostic procedures as well as various clinical situations. METHODS: We studied 62 patients sensitive to Dermatophagoides pteronyssinus (Der p), 30 atopic controls and 12 healthy donors. We determined slt production using the CAST-ELISA technique and histamine release using two concentrations of Der p extract (20 and 2 ng/mL). We also carried out quantification of specific and total IgE levels, skin tests and pulmonary function test on each patient. RESULTS: We observed a significantly increased slt release after in vitro stimulation with Der p. There was a significant difference in the slt release between controls and sensitive patients (P < 0.001) and between atopic controls and sensitive patients (P < 0.001). The data are similar to those obtained with histamine release. We noted a positive correlation (P < 0.001) between slt and histamine release (r = 0.71, at 2 ng/mL and r = 0.83 at 20 ng/mL). We also found a positive (P<0.001), although weak (r=0.4 with at 2ng/mL, and r = 0.34 with P = 0.003 at 20 ng/mL) correlation between slt release and specific IgE levels as well as between slt release and skin-test reactivity (r = 0.49 at 2 ng/mL and r = 0.45 at 20 ng/mL; P < 0.001). No significant correlation between slt release and asthma severity was observed, although a trend toward higher slt production in severe and moderate asthma was detected. We found a significant (P<0.001) but weak (r=-0.3) negative correlation between age and slt release. With respect to sex-related differences, we found significant differences (P < 0.05) in slt release between the sexes with a higher slt release in men than in women. CONCLUSION: We conclude that CAST-ELISA for quantification of slt production is a useful in vitro method for diagnosing sensitization to Der p. There also exists a close correlation between slt release and other parameters of allergic sensitization in vitro as well as in vivo.

Adolescent↗
PubMed1994

Pulmonary function, activated T cells, peripheral blood eosinophilia, and serum activity for eosinophil survival in vitro: a longitudinal study in bronchial asthma.

A close correlation among the number of activated, peripheral blood T helper cells, eosinophilia, and airflow obstruction has been reported in patients with asthma. To test these cross-sectional data we performed a prospective, longitudinal study investigating the relationships among T-cell activation in peripheral blood, eosinophilia, forced expiratory volume in 1 second (FEV1), and serum activity toward eosinophil survival in 20 individuals with asthma over a period of 21 days after admission to a clinic located 1560 m above sea level. During the study, maintenance treatment with inhaled beta 2-agonists and theophylline was unchanged. Five patients had also been taking inhaled corticosteroids, and this was also not changed during the study period. According to the changes in pulmonary function observed at the end of the study, patients were divided into three groups: twelve patients whose pulmonary function improved by more than 10% from baseline (group I), four patients whose pulmonary function deteriorated by more than 10% from baseline necessitating therapeutic intervention (group II), and four patients with no change in FEV1 (< 10% from baseline) (group III). Activation of T cells as determined by interleukin-2 receptor expression, number of eosinophils, and serum activity toward eosinophil survival in vitro declined in group I; whereas FEV1 increased. The decrease in FEV1 in group II was associated with an increase in interleukin-2 receptor-positive T cells, number of eosinophils, and serum activity. In group III FEV1, interleukin-2 receptor expression on T cells, the number of peripheral blood eosinophils, and the measured serum activity for eosinophil survival in vitro did not change significantly from baseline.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Beta-receptor decrease in bronchial asthma.

Sinesterases that intervene in cAMP and oGMP equilibrium in the cytoplasm of mast cells are activated by the adrenergic system through beta-receptors. A study was made on 96 atopic patients with mono sensitization to Dermatophagoides pteronissinus, in 3 groups. Radioligands were used to quantitate the number of beta receptors. In the control group mean no/cell was 541, bronchial symptomatic patients had 327 and nasal symptomatics 348. Asymptomatic patients were similar to controls. The results were similar with pollen-sensitive patients. Beta receptor decrease is a consequence of clinical allergy in atopic patients and is secondary to the immunological events that follow antigen-antibody reactions and cell membrane changes.

Adenylyl Cyclases↗
PubMed1991

Mechanism of ketotifen action in hypersensitivity reactions. Its effect on cellular enzymatic activities.

In this study we observed that asthmatics had less methyltransferase activity and greater phosphodiesterase activity than healthy individuals. These enzymatic activities were nearer to values obtained in healthy individuals when we preincubated cells with ketotifen. The modulator effect of this drug on these two enzymes permits, on the one hand, to re-establish the beta-receptor numbers expressed on the membrane, and on the other hand, to inhibit mediator secretion provoked by antigenic stimulus. With its action on adenylate cyclase and phosphodiesterase activities, it allows cAMP intracellular accumulation and hinders the secretory process. Through its action on methyltransferase activity, it is responsible for the normalization of beta-receptor expression observed in asthmatic patients treated with ketotifen.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

In vitro ketotifen protection in bronchial hyperreactivity.

There are drugs, such as ketotifen, that inhibit bronchospasm through different mechanisms. In this study, we looked at the changes in the number of sanguineous cells that ketotifen produces, especially in basophil cells, that could explain its prophylactic effects in bronchial hyperreactivity disclosed by exercise, as well as its relation to the variations in basal and total histamine in blood. 22 patients were selected, with a diagnosis of extrinsic bronchial asthma with sensitization against Dermatophagoides, and were compared to a control group. They all underwent an exercise test. Blood samples were taken before and after exercise in order to measure the number of leukocytes and the changes in basal and total histamine. We found that the number of basophils does not increase after exercise in untreated patients, while it does in the control group and in treated patients. This implies that ketotifen stabilizes the basophil cells, hindering their degranulation and the subsequent liberation of mediators that would produce bronchospasm after exercise.

Adolescent↗
PubMed1991

Number of beta-receptors in patients allergic to Dermatophagoides pteronyssinus.

This study was carried out on 96 atopic patients with monosensitization against Dermatophagoides pteronyssinus and 30 control individuals. The patients were divided into 3 subgroups: 27 asymptomatic patients, 27 patients who only presented nasal symptomatology, and 27 patients with marked bronchial symptomatology. Total serum IgE, antigen-specific histamine release, and the number of beta 2-adrenergic receptors in peripheral blood lymphocytes in all patients were determined. The control group presented the highest number of beta-receptors in comparison with the bronchial symptomatic and nasal symptomatic patients. However, asymptomatic patients presented numbers of beta-receptors similar to controls, with no significant differences between both groups. No significant correlation was found between beta-adrenergic receptors and levels of total serum IgE. On the other hand, correlation between beta-receptors and specific histamine release was detected only in symptomatic nasal patients. It can be postulated that the decrease in beta-receptors is a consequence, and not the cause, of atopy.

Adult↗
PubMed1991

Influence of seasonal variations on histamine release and other immunological parameters in pollinosis.

One hundred and fifty-six pollen-sensitive patients with sensitization to grass pollen only were chosen for this study; 65 patients were allergic to Dermatophagoides, while 45 were non-allergic subjects with no atopic history. The following tests were carried out on all patients: histamine release of total blood, basal histamine, total histamine, determination of total IgE and specific IgE (RAST) serum levels, serum hemagglutinating antibodies and skin tests. Seasonal increase of IgE was observed, with post-seasonal fall; 50% of the cases reached normal values. However, RAST as a semiquantitative method did not prove to be useful in the detection of variations in specific IgE levels. During pollination, an increase in titers in pollen-sensitive subjects was seen. This was attributed to a humoral immune response epiphenomenon which was independent of IgE. The histamine release test was significantly greater during pollination in pollen-sensitive subjects. The total of stored histamine increased during the months of allergenic exposure.

Animals↗
PubMed1991

Number of beta-receptors in rhinitic pollinic patients.

The study was carried out on venous blood from 67 patients with seasonal rhinoconjunctivitis caused by sensitization to grass pollen and 30 control individuals. Total IgE determination, antigen-specific histamine release test against two concentrations of Phleum pratense, and quantification of beta 2-adrenergic receptor numbers in lymphocyte membrane of peripheral blood were done on all patients. Those pollinic patients who were asymptomatic at the time of the study had 500.07 +/- 237.27 receptors/cell; no significant differences were established with the control group, with 541.53 +/- 123.63 receptors/cell. However, both the control group and asymptomatic patients had receptor numbers which were significantly higher than those of symptomatic pollinic patients, with 376.81 +/- 158.65 receptors/cell (p < 0.01 and p < 0.05, respectively). The average decrease in number of receptors in symptomatic pollinic patients was 30.42% in relation to controls and 24.65% in relation to asymptomatic patients. Within the subgroup of pollinic patients, studied both in and out of season, the number of beta 2-adrenergic receptors had an average decrease of 13.22% during pollination, with 363.7 receptors/cell. Once the pollination season was over, this figure increased to 419.1 receptors/cell, establishing significant differences with p < 0.025. The number of beta 2-adrenergic receptors did not correlate with total seric IgE figures or with antigen-specific histamine release. These data indicate that the decrease of these receptors does not constitute the causal factor of atopic diseases; it seems more likely to be a consequence of the same.

Adolescent↗
PubMed1991

Study of IgE-dependent basophil releasability in allergic patients.

For this study, venous blood from 160 patients with a diagnosis of asthma and/or rhinitis was used. Histamine release test (H.R.T.) with anti-IgE at 1/5 and 1/25 dilutions and with causal antigen in the case of atopic patients (144) was carried out on all patients. Basophils from atopic patients released more histamine than those from nonatopic patients (p < 0.001). Basophils of atopic patients released more histamine with 1/5 anti-IgE dilution (p < 0.01), while non-atopic patients did so with the 1/25 dilution (p < 0.05). On grouping atopic patients according to positive or negative results in Ag-specific histamine release, 14% of patients presented negative Ag-specific H.R.T. and 85.7% of the cases did not respond to anti-IgE stimulus; this was 12% of the total number of atopics. On the other hand, 17% of the patients studied did not show positive histamine release against anti-IgE and 70.6% of them had negative Ag-specific release. As for the effect of age on IgE-dependent histamine release, the group of patients who presented greater releasability corresponded to those older than 6 years of age. The discrepancies observed between the clinical history, skin tests, serum IgE and antigen-dependent histamine release in some patients could be related to the individual basophil ability to release histamine. Therefore, this basophil releasability evaluation has an important practical application in discerning false negatives in antigen-specific H.R.T.

Adolescent↗
PubMed1990

Seasonal influence on serum and receptor-bound IgE in pollinosis.

Analysis of the correlation between bound and free IgE in 32 patients with pollinosis before and during the pollen season disclosed no correlation between bound and free IgE in rhinitic patients before the pollen season, while there was correlation during the season. In the asthmatic patients there was good correlation before the pollen season rather than during it.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Results of the in vitro follow-up of immunotherapy.

With the advances made in allergological diagnosis, thanks to the application of various in vitro immunological techniques, we have also learnt more about the immunological modifications produced during the course of the immunotherapy. Among the techniques which will detect immunological changes is the histamine release test, which will show a decrease in antigen-specific histamine release. On the other hand, both total IgE and IgG4 are modified in the course of this immunotherapeutic treatment.

Follow-Up Studies↗
PubMed1987

The viral factor in childhood asthma.

Independently of the important role the infections bacterial factor plays in childhood asthma, many authors have considered the virus the primary triggering factor of bronchospasm. This latter factor has been so exaggerated that some authors have even conceded it the maximum importance. In studies carried out with a more numerous population than in those works presented so far, controlling the presence of antibodies during the crisis and a week later in serum from asthmatic children, the authors found that only 13.5% presented specific antibodies against one or two of the sixteen viral antigens studied. These children at the same time developed a bacterial infection which remitted with antibiotic therapy, with the consequent disappearance of the asthma. In etiopathological studies realized in 700 children it was equally confirmed that the bacterial factor was involved in 90% of the cases, in the sense of a sinopulmonary syndrome. More profound studies are needed to clarify this point which is held in little consideration by many clinicians.

Antibodies, Viral↗
PubMed1980

[The current problems of food allergy].

Humoral and cellular immune mechanisms take part in the food allergies. In the humoral mechanisms there are anaphylactic, cytotoxic and precipitating antibodies. Therefore and because of uncertain and incomplete remarks of the patient, the diagnosis of food allergies is difficult. At present, the hemagglitination technique is the most reliable diagnostic test; the determination of unspecific and specific IgE is less suitable. In most cases, multiple sensitizations have been found. In food allergies, as the most frequent shock organ, the skin has been found, often combined with the gastrointestinal and respiratory tract (asthma). The participation of neurologic effects is discussed.

Food Hypersensitivity↗
PubMed1980

Kartageners syndrome: a report of six cases with special reference to humoral and cellular immunity.

4 men and 2 women presenting with Kartagener's syndrome were studied. Humoral and cellular immunity were evaluated by measuring immunoglobulin levels, total complement activity, C3, C4 and C5 levels, lymphocyte subpopulations, lymphoproliferative response to PHA, delayed hypersensitivity skin reactions and histocompatibility antigens. The in vitro tests for cellular and humoral immunity showed normal results, or only transitory alterations. However, the in vivo tests clearly showed a decrease in the delayed response in the skin tests using bacterial and mycotic antigens and PPD. In two siblings the HLA typing showed identical haplotypes. The results are presented taking into account the new physiopathogenetic concepts of Karagener's syndrome with respect to dysfunction of the ciliated columnar epithelium and chemotactic defects of the nonciliated blood cells found in these patients.

Adolescent↗