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Biomedical subjects

R Urbanek

Publications and source records attributed to R Urbanek.

At least 91 records · Page 5Linked to original sources
PubMed1990

Determination of N-methylhistamine in urine as an indicator of histamine release in immediate allergic reactions.

The use of the urine histamine metabolite, N-methylhistamine (N-MH), as a parameter of histamine release in immediate allergic reactions was investigated. Baseline levels were determined in 34 normal control subjects and 29 atopic patients. Increases of urine N-MH values were measured during histamine infusions and in venom-allergic patients receiving bee-sting challenges. N-MH was determined by a newly developed radioimmunoassay. Baseline levels in control subjects and atopic patients demonstrated no significant differences. With regard to challenge tests, fluctuation of N-MH levels during a 6-hour period was measured. Random 6-hour increases in healthy and atopic subjects ranged from 5% to 41%. Before infusion of histamine (0.25 micrograms/kg/min for 30 minutes), baseline values were 137 +/- 11.4 micrograms N-MH per gram of creatinine and 9 +/- 1.1 micrograms N-MH per hour (n = 9). Levels peaked 1 hour after infusion at 275 +/- 45 micrograms/gm of creatinine and 44 +/- 5.6 micrograms/hr and decreased to resting levels after 2 hours. Metabolization by N-MH accounted for 9.5% +/- 4.9% (range, 2.4% to 18.4%) of infused histamine in the urine of the nine subjects. Bee-sting challenges were performed in 12 patients and three control subjects. Only in three patients experiencing generalized urticaria, nausea, dyspnea, and hypotension were significant increases of urine N-MH levels (138%, 144%, and 238%) observed. All other patients and three normal control subjects demonstrated normal local reactions without increase of N-MH values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Antigenicity and allergenicity of hypoallergenic hydrolysate for infant nutrition].

The antigenicity/allergenicity of protein components in hypoallergenic formulae is altered by hydrolysis. Two different hydrolysate formulae, hydrolysate 1 = cow milk based; hydrolysate 2 = soya/beef collagen based, were investigated with respect to their specific IgG/IgE binding capacities using the sera of 41 healthy controls, 40 atopic and 12 cow milk allergic subjects. Furthermore, histamine liberation from basophils on incubation with milk proteins and the hydrolysates was measured in 5 healthy and 3 cow milk allergic individuals. Nearly all probands demonstrated specific IgG binding with hypoallergenic formulae. Anti-hydrolysate 1 IgG titres were higher than titres against hydrolysate 2 in the cow milk allergic and healthy populations. Nonhydrolyzed cow milk elicited IgE binding in all cow milk allergic sera. IgE-antibody for hydrolysate 2 could only be demonstrated in one atopic subject. Hydrolysate 1 showed binding capacity for the IgE-antibody of one atopic and 3/12 cow milk allergic patients. Histamine liberation followed in-vitro incubation with both hydrolysates in one out of 3 cow milk allergic subjects and two out of these cases following incubation to unprocessed cow milk protein. A decreased antigenicity/allergenicity can be demonstrated for the two hydrolysates investigated, however antigenic/allergenic reactivity is still present to some degree. Therefore, the therapeutic application of hypoallergenic formulae in patients with specific sensitization to cow milk should be based on the results of the above-mentioned in-vitro parameters and if necessary skin tests and oral challenges.

Adolescent↗
PubMed1990

[Hyposensitization: indications and expectations].

Allergy is the most frequent immunologic disorder in childhood. The prevalence of allergic complaints among children is estimated as about 10%. The diagnosis of an allergy takes the following factors into account: The patient's history, skin test, determination of total and specific IgE antibodies and a provocation test to a diseased organ. Hyposensitization is recommended for allergic patients without any significant improvement in spite of avoidance of allergen and in spite of pharmacologic therapy. Modified allergens/allergoids demonstrate a comparable efficacy as a conventional subcutaneous allergen immunotherapy. Measurement of specific IgE- and IgG-antibodies permits an evaluation of degree of sensitization and/or immune response to hyposensitization treatment.

Allergens↗
PubMed1990

[Sensitization to 10 important air-borne allergens in school children].

Sensitization patterns and frequencies for 10 important aeroallergens were tested in a cross-sectional study with 704 schoolchildren (7-16 years) using a standardized skin prick-test method and highly purified immunochemically characterized test-solutions. A ratio of allergen and histamine wheal diameter of 0.5 or more was classified as a positive skin test result. We found a positive skin prick-test to at least one of the aeroallergens in 242 (34.4%) of the children. Among these 39.6% showed monosensitization and 9.8% polysensitization to at least 6 allergens. The most common allergens were grasspollen (19.2%), birchpollen (14.8%), house-dust mite (13.4%), catdander (10.5%) and hazelpollen (9.7%). Monosensitized children reacted mainly to grasspollen and house-dust mite, whereas positive reactions to animal dander and moulds only occurred in polysensitized children more frequently. Reactivity of the tested allergens, measured by the wheal size, was strongest for grasspollen and house-dust mite and the weakest for cladosporium and alternaria. The high prevalence of sensitization to inhalant allergens is an important risk-factor for allergic disease in childhood.

Adolescent↗
PubMed1989

The subclass of IgG antibody in allergic disease: II. The IgG subclass of antibodies produced following natural exposure to dust mite and grass pollen in atopic and non-atopic individuals.

In an attempt to understand the role of the different IgG subclasses in allergic disease, we have studied the subclass of IgG antibody to dust mite (HDM) and grass pollen (GP) produced as a result of natural exposure. Studies were carried out on 40 atopic children and 100 atopic adults who had never received immunotherapy. Thirty-two non-atopic adult controls were also studied. The specificity of the assay for IgG antibodies to dust mite was confirmed by inhibition with the homologous extract but not mite culture medium or fetal calf serum. IgG1 antibodies to HDM could be detected in most atopics (94%) and non-atopics (97%), and similar results were obtained for GP (81% and 100%, respectively). IgG4 antibodies to HDM were detected in more atopics (66%) than non-atopics (53%) and the difference was more marked for GP (72% vs. 19%). While the levels of IgG1 antibodies were not significantly different in the two groups, the levels of IgG4 antibodies were much lower in the non-atopics (P less than 0.001, Mann-Whitney U-test). These data show that all subjects were capable of recognizing and mounting an IgG1 antibody response to these inhaled antigens. Atopic individuals differed from normal subjects in the frequency with which they made IgG4 antibodies in response to natural exposure to both dust mites and pollen.

Adult↗
PubMed1989

Combination of parenteral and oral immunotherapy in grass pollen-allergic children. A double-blind controlled study of clinical and immunological efficacy.

Twenty patients with a proven sensitization to grass pollens were treated with parenteral "priming" and subsequently with either oral "booster" (n = 10) or placebo (n = 10) extension course. The study was carried out in a double-blind manner. Cumulative preseasonal parenteral dosage was 3,100 NU (Noon Units), patients in the oral group subsequently received 123.9 mg of grass pollen extract during the pollen season. No side effects were noted after intake of the oral preparation. No significant difference (95% confidence interval) were noted comparing results of in vivo (skin prick test and conjunctival provocation test) and in vitro tests (specific serum IgE- and IgG-antibodies) between the two groups. Analysis of symptom and medication scores as well as subjective assessment of patients revealed no superiority of oral "booster" over placebo. Data obtained in this study does not support the concept of combined parenteral and oral treatment. This is in contrast to work reported previously.

Administration, Oral↗
PubMed1989

Relevance of basophil histamine release changes during venom immunotherapy.

We investigated the effect of rush and long-term venom immunotherapy on histamine release parameters in bee venom allergic patients. Ten patients received rush venom immunotherapy, and histamine release data were obtained immediately before and after treatment. 17 patients were assessed by histamine release 24 to 63 months after termination of long-term venom immunotherapy. A control group of 10 non-allergic subjects was included in this study. Histamine released from whole blood was determined in a sensitive radio-enzymatic assay using a single isotope technique. Bee venom phospholipase A-induced histamine release from whole blood proved to be a test procedure of high specificity and sensitivity. Eight of 10 untreated patients and no control subject showed significant antigen-induced histamine release. Results obtained from patients immediately after successful rush venom immunotherapy showed an important decrease (mean 45.9%) of total histamine content of basophil leukocytes in all patients. Antigen-induced maximum histamine release was found to be increased in one, decreased in two and unchanged in seven patients. In patients who received long-term immunotherapy cell sensitivity to phospholipase A was significantly lower than in a group of untreated patients (P less than or equal to 0.002). These results suggest that even years after discontinuation of immunotherapy, histamine release parameters reflect patients' protection from systemic sting reactions as assessed by sting challenges. Histamine depletion of basophils induced by rush immunotherapy may play an important role in patients' protection immediately after termination of the rush regimen.

Adolescent↗
PubMed1989

Anti-IgE- and complement-induced histamine release from peripheral leukocytes in normals and atopics.

Anti-IgE- and complement-induced histamine release from isolated basophils was compared in normal and atopic subjects. Activated complement was generated by incubation of a serum pool from normal donors with zymosan. Histamine was measured by a single-isotope radioenzymatic assay. In atopics, the mean histamine release induced by heterologous complement was significantly higher than in normals (p less than or equal to 0.01). Anti-IgE-mediated histamine release showed no differences between atopics and normals. Regarding the histamine release as a function of the age of the donor, we observed significantly higher complement-induced release values in normal children aged 1-10 years compared to those aged 10-20 and greater than 20 years (p less than or equal to 0.05). Anti-IgE-induced histamine release showed no age-related differences in normals or atopic patients. As a high complement-mediated leukocytic histamine release was more commonly found in atopics with heterologous complement, this phenomenon appears not to be due to a higher rate of complement activation in the serum of atopics, but rather to an intrinsic cell abnormality. Moreover, these results suggest that age-related releasability patterns might be considered when studying complement-induced histamine release. Differences between IgE- and complement-mediated histamine release indicated that parameters of releasability must be defined with respect to each stimulus.

Age Factors↗
PubMed1989

[Epidemiologic recording of bronchial asthma in the school child].

Bronchial asthma is the most frequent chronic disease in childhood. Nevertheless, no definition of the disease is known that would enable a satisfactory epidemiological recording of asthma. In 704 schoolchildren, typical signs and symptoms of asthma were recorded within the framework of a standardized interview. The occurrence of asthmatic symptoms was quantified by means of a symptom score. In 555 of the probands, bronchial reactivity was tested by means of an inhalative challenge with carbachol. The information gathered from the interview and the carbachol challenge test was placed in relationship to the family doctor's diagnosis of "bronchial asthma". Lifetime prevalence of asthma diagnosed by the family doctors is 4.97% with a clear male predominance. The asthmatic symptoms showed varying frequencies and validity compared with the family doctor's diagnosis. The occurrence of dyspnoea appears to be particularly sensitive (77%). Dyspnoea coincident with exercise is highly specific (99%). The sensitivity of the combination of carbachol test and symptom score is 92% and the specificity is 75%. The instruments described above offer a reliable possibility for epidemiological field research to record the prevalence of bronchial asthma in schoolchildren.

Adolescent↗
PubMed1989

[Disorders of immune function in children with selective IgA deficiency].

Numerous additional alterations of immune function in patients with selective IgA deficiency (serum IgA less than 0.05 g/l) have been described. In this group of patients we have investigated the connection with allergic diseases and alterations of the other immunoglobulin isotypes. Sera of 44 children from 1 3/12 to 18 years were analysed. In all patients serum IgA was below the nephelometric detection limit of 0.05 g/l). Using a more sensitive ELISA, IgA could be detected in all sera in concentrations ranging from 10 micrograms/l to 0.04 g/l. 25 children (57%) revealed a profound elevation of IgG serum levels, in 27 (61%) IgM was elevated above the upper age related normal value. In 7 patients (16%) with normal IgG serum levels a combined IgG2-IgG4 deficiency was found. In most cases these patients had unusually frequent and severe infections. Total IgE serum levels were determined by a RIA technique. In addition, an IgE-mediated sensitization to the most common food and inhalation antigens was detected by a standardized procedure (Phadiatop, Pharmacia). In 9/44 children (20%) IgE was less than 2 U/ml (lowest detection limit), 27 patients (62%) revealed levels of 6-86 U/ml within the age-related normal range. In 8 patients (18%) total IgE was above 381 U/ml. Four patients demonstrated a sensitization to inhalants, specific IgE antibodies to nutritive antigens were detected in three children.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Allergic reactions to insect bites].

An allergic reaction to stings by insects can occur within minutes and may be fatal. The history serves to assess the severity of the reaction and may aid in the identification of the insect involved. The diagnosis is confirmed by a skin test and the presence of insect venom specific IgE. Minor allergic reactions can be treated with drugs, the more severe forms require hyposensitization therapy with pure insect venom, especially when the risk of life threatening reaction due to reexposure to insect sting is high. A protection against insect stings can be achieved within days. During the venom immunotherapy an antibody rise occurs and is followed by a suppression of specific IgE production later on. Allergy against hymenoptera venom is a suitable model for hyposensitization treatment.

Ant Venoms↗
PubMed1989

[Bronchial asthma and bronchial hyperreactivity].

Bronchial hyperreactivity to allergens and non-allergic stimuli is a feature of most patients with asthma as measured by the response to inhalants as pharmacological agents and physical stimuli. In contrast to adults there is an obvious relation of asthmatic episodes to allergen exposure in childhood. However, the development and persistence of bronchial hyperreactivity is well described by interaction of inflammation cells and their mediators. Not only the severity of asthma is related to the severity of bronchial hyperresponsiveness but also the therapeutic strategies.

Asthma↗
PubMed1988

Immediate hypersensitivity to ovalbumin in children with hen's egg white allergy.

Serum concentrations of IgE, IgG1 and IgG4 antibodies to ovalbumin and basophil sensitivity to ovalbumin were compared with the results of a titrated oral provocation test with ovalbumin in 27 children sensitive to hen's egg white, of whom 17 responded with an immediate hypersensitivity reaction. Neither the serum level of IgE, IgG1 and IgG4 antibodies to ovalbumin nor a positive histamine release test predicted the clinical relevance of ovalbumin sensitivity. The children with a positive challenge test had a significantly higher IgE/IgE4 ratio and tended to be younger and to have higher serum IgE levels and a higher IgG1/IgG4 ratio than those with a negative challenge test. We conclude that an oral provocation test is necessary to confirm the diagnosis of food allergy.

Child↗
PubMed1988

[Status of determining the transepithelial potential difference (PD) of the respiratory epithelium in the diagnosis of mucoviscidosis].

Patients with cystic fibrosis (CF) have an increased transepithelial electrical potential difference (PD) on the respiratory mucosa. In an attempt to investigate the diagnostic value of this measurement 12 patients with CF, 15 first degree relatives and 38 controls were studied. A nasal recording electrode and a reference electrode placed subcutaneously in the left upper arm were used. The recorded values of nasal PD were significantly (p less than 0.0001) higher (-61 mV +/- 7) than in subjects without cystic fibrosis (-21 mV +/- 6) and in CF relatives (-25 mV +/- 8). There was an overlap in values measured on the lip and on the tongue of subjects with and without cystic fibrosis. No differences in nasal PD were noted between male or female subjects. Transepithelial potential difference declined slightly with age. In addition, a superfusion with amiloride as inhibitor of sodium transport induced a 62% reduction in nasal PD in a cystic fibrosis patient as compared to a healthy subject (31%). These results as well as the good reproducibility (r = 0.99) demonstrate that the measurement of transepithelial potential difference on the nasal mucosa could be an additional diagnostic tool in cystic fibrosis.

Adolescent↗
PubMed1987

Development of a semi-quantitative enzyme-linked immunosorbent assay (ELISA) for detection of human IgG subclass antibodies.

We have developed a sensitive enzyme-linked immunosorbent assay (ELISA) which measures antibodies to bee venom phospholipase A2 (PLA2) and hyaluronidase (HYAL), horse IgG, bovine casein, and the bacterium Streptococcus mutans in each of the four human IgG subclasses. For this purpose, we have used mouse monoclonal antibodies (McAb) specific for each subclass and one which showed 'pan-IgG' reactivity. Binding to human IgG was similar for all the McAb and dilution of human IgG resulted in similar dilution curves for each subclass. Results were expressed as arbitrary U ml-1 by comparing the optical density obtained with each subclass-specific McAb to a reference curve for total IgG antibody constructed using the 'pan-IgG' McAb. Close agreement was found between the total amount of IgG antibody and the sum of the antibody in each of the four subclasses (PLA2 r = 0.90, horse IgG r = 0.98, bovine casein r = 0.84, S. mutans r = 0.85), confirming that these assays provide semi-quantitative measurements of the amount of subclass-specific antibody.

Antibodies, Monoclonal↗
PubMed1987

Immunotherapy with Hymenoptera venoms. Position paper of the Working Group on Immunotherapy of the European Academy of Allergy and Clinical Immunology.

Immunotherapy with Hymenoptera venoms is widely used throughout the world and is accepted as an effective treatment for most patients with Hymenoptera venom allergy. There are, however, still some unresolved problems with this form of treatment. At present there is no definite test which makes it possible to identify patients at risk - and thus candidates for immunotherapy - unequivocally. On the basis of prospective studies on the natural history of Hymenoptera allergy, venom immunotherapy is indicated in adults with severe systemic anaphylaxis. It is usually not necessary in patients with large local reactions only. Children with mild systemic reactions, e.g. urticaria, will need immunotherapy only in case of repeated reactions and/or a high risk of re-exposure. The selection of venoms for immunotherapy may lead to some confusion owing to common antigenic determinants shared by venoms of various Hymenoptera species. Many different regimens for immunotherapy have been proposed. At present, the three main are: rush, stepwise or clustered and classical. The maintenance dose of 100 micrograms usually protects from life-threatening reactions. However, in some patients 200 micrograms are necessary for complete protection. The usual interval between maintenance injections is 4 to 6 weeks. In many patients a strong increase of venom specific serum IgG-antibodies usually parallels clinical protection induced by venom immunotherapy, although many exceptions have been reported. Allergic side effects of venom immunotherapy are not rare, especially with honey bee venom and during the initial phase of dose increase. The question of the duration of venom immunotherapy is handled differently: although some authors recommend treatment for life, most suggest treating patients until skin tests and RAST become negative.

Adult↗