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At least 235 records · Page 13Linked to original sources
PubMed2005

A mutant of the major apple allergen, Mal d 1, demonstrating hypo-allergenicity in the target organ by double-blind placebo-controlled food challenge.

BACKGROUND: Allergen-specific immunotherapy for food allergy has been hindered by severe side-effects in the past. Well-characterized hypo-allergenic recombinant food allergens potentially offer a safe solution. OBJECTIVE: To demonstrate hypo-allergenicity of a mutated major food allergen from apple, Mal d 1, in vitro and in vivo. METHODS: A mutant of the major apple allergen, Mal d 1, was obtained by site-directed mutagenesis exchanging five amino acid residues. Fourteen patients with combined birch pollen-related apple allergy were included in the study. Hypo-allergenicity of the mutant rMal d 1 (rMal d 1mut) compared with rMal d 1 was assessed by in vitro methods, i.e. RAST (inhibition), immunoblotting and basophil histamine release (BHR) and in vivo by skin prick test and double-blind placebo-controlled food challenge (DBPCFC). RESULTS: RAST analysis (n = 14) revealed that IgE reactivity to rMal d 1mut was twofold lower than that of the wild-type molecule (95% confidence interval (CI): 1.7-2.4). RAST inhibition (n = 6) showed a 7.8-fold decrease in IgE-binding potency (95% CI: 3.0-12.6). In contrast to this moderate decrease in IgE-binding potency, the biological activity of rMal d 1mut assessed by SPT and BHR decreased 10-200-fold. Hypo-allergenicity was confirmed by DBPCFC (n = 2) with both recombinant molecules. CONCLUSION: A moderate decrease in IgE-binding potency translates into a potent inhibition of biological activity. This is the first study that confirms by DBPCFC that a mutated recombinant major food allergen is clinically hypo-allergenic. This paves the way towards safer immunotherapy for the treatment of food-allergic patients.

Adolescent↗
PubMed1986

[Radioimmunologic detection of IgE and IgG antibodies against drugs. Conclusions after experience with over 1200 patients].

Based on the radioallergosorbent test (RAST), the authors have developed a series of assays to detect IgE and IgG antibodies against a number of frequently used drugs. In this system drugs bound covalently to cellulose paper are incubated with serum and washed; the hapten-specific IgE and IgG antibodies are then qualified and quantified by means of 125I-labelled anti-human IgE and IgG respectively. Thus far the sera of 1,228 patients have been analyzed following therapy with betalactam antibiotics, co-trimoxazole, salicylates, pyrazolones, flavonoids and tetrahydroisoquinoline. The induction of IgG antibodies is a frequent occurrence and that of IgE rare. Isolated high titers of IgE are associated mainly with anaphylactic reactions; in the presence of simultaneously raised IgG titers such side reactions are often absent. Highest IgG titers were found in patients with immune hemolysis after betalactam antibiotics, flavonoids and tetrahydroisoquinoline. In the other types of side reaction specific IgG titers were not significantly higher than in patients without side reactions. The estimation of circulating antibodies against drugs cannot yet be utilized diagnostically except in the rare cases of anaphylactic side reactions. However, the method described permits specific and sensitive detection of sensitization and is suited for scientific purposes.

Clinical Trials as Topic↗
PubMed1979

[Determination of the IgE serum level: RIST or PRIST? Results of a ring test in Switzerland].

Serum IgE concentrations, determined by two commercial kits (Phadebas RIST and PRIST) in 93 adult controls resulted in a geometrical mean value of 47 (RIST) and 35 U/ml (PRIST) respectively within a + 2 SD value of 195 and 331 U/ml respectively. The difference between the separated random samples is statistically significant (t = 3.79; p less than 1%), but the correlation is still fairly satisfactory (r = 0.79). In the lower regions the IgE values with RIST are as a rule a little higher than with the PRIST method. Surprisingly, one patient showed an extremely low IgE value (7 U/ml) with PRIST, but a considerably higher one (530 U/ml) with RIST. Such marked differences are found occasionally in the literature: heterophile antibodies against bovine gammaglobulin are regarded as responsible for the interference in the Sephadex system of RIST. As the reproducibility of the IgE determinations with the PRIST method is excellent (the correlation coefficient for two PRIST determinations was r = 0.93), and as PRIST allows much lower IgE estimates, this procedure should be given preference, particularly in pediatric patients. On the other hand, RIST must be used for the determination of extremely high values, as for instance in patients with severe atopic dermatitis or with parasitic infestations. In fact they can no longer be exactly evaluated by PRIST. Quality control of IgE serum determinations among twelve randomly chosen laboratories in Switzerland in 5 patients was satisfactory, with one exception. In the case of extremely high values, however, only a few laboratories try to determine the exact value. Indications of more than 500 U/ml were considered sufficient, with actual values amounting to 12,500 U/ml. It is also advisable to standardize the serum dilutions, the use of reference serum and the price. Finally, the indications for IgE determination are discussed. It is considered to have an important bearing on the differential diagnosis and prognosis of atopic diseases in infants and children.

Adult↗
PubMed1985

Induction of an auto-anti-IgE response in rats I. Effects on serum IgE concentrations.

With a view to specifically suppressing the IgE isotype, rats of high (BN) and low (PVG.RT1u) IgE-responding phenotypes were immunized with a highly purified rat IgE myeloma (IR2) in an attempt to induce an anto-anti-IgE response. Rat IgE antibodies against epsilon determinants were detected in the serum of IR2-immunized animals using a solid-phase (plate) radioimmunoassay. The auto-anti-IgE antibodies detected were found to bind to IR2, to a second rat IgE myeloma (IR162) and to mouse monoclonal IgE but not rat IgG. The specificity of the anti-epsilon binding was shown by inhibition studies. The raising of an auto-anti-IgE response in PVG.RT1u rats severely depleted the serum level of circulating IgE for at least 8 weeks. In BN rats, immunization with IR2 caused marked fluctuations in serum IgE levels. The rats in both strains remained healthy throughout the experiment. The rate and route of IgE break down was not altered in anti-IgE-producing rats. The relevance of the present model in understanding and possibly controlling allergic disorders is considered.

Animals↗
PubMed1992

Leakage of carbonic anhydrase III from normal and denervated rat skeletal muscle following contractile activity.

Skeletal muscle extracellular carbonic anhydrase III was investigated in anesthetized rats by a microdialysis technique. A small dialysis probe was inserted into the tibialis anterior (TA) muscle and perfused continuously. Perfusates were collected before and during muscle contraction, induced by electrical stimulation of the muscle or of the sciatic nerve. In the perfusate of resting normal and denervated muscle, the concentration of CA III was 10 to 12 ng/mL, as measured by a radioimmunosorbent technique. During contractile activity, the concentrations of CA III increased markedly in the normal and denervated muscle. A TA muscle suspended in physiological saline behaved similarly, even though the leakage before and during contraction was higher than in vivo. The results show that skeletal muscle leaks CA III both in vivo and in vitro, a leakage which was markedly increased by contractile activity. The microdialysis technique should also be useful in humans to study the efflux of various proteins from different kinds of diseased or fatigued muscles.

Animals↗
PubMed1978

Immunoglobulin E in human aqueous humor and corresponding serum. A physiopathological and clinical study.

The analysis of IgE in aqueous humor yielded an average concentration of 3.4 +/- 0.97 U/ml for 22 cataract patients and 5.5 +/- 3.42 U/ml for five uveitis patients. The IgE level in aqueous humor (IgEa.h.) of the cases examined is most probably, beside hematoocular diffusion of serum IgEs, the result of intra-ocular IgE production. In comparison with (mostly normal) IgEs levels, the IgEa.h. concentration appears relatively elevated, not only with uveitis patients, but also with cataract patients, above all when lenticular opacity is accompanied by other ophthalmic diseases (glaucoma, high myopia, diabetes). This "increase" of IgEa.h. concentration in very probably due to the radioimmunosorbent (RIST) technique employed, the most sensitive method available at the time of the present study. Thus, the calculated IgEa.h. value in the cataractous eyes should be regarded simply as approximate to the normal IgEa.h. concentration. These values are of clinical significance however, since a reference IgEa.h. mean-value is indispensable to the interpretation of pathologically high IgEa.h. levels and ethics do not permit of IgEa.h. determination in healthy eyes. The mean IgEa.h. levels of the delayed-type uveitis and cataract patients examined reveal no significant differences. IgEa.h. determination could make a contribution to the etiological clarification of, for example, immediate-type uveitis cases and intra-ocular parasitosis and serve as an appropriate model to study intra-ocular immunomechanisms.

Adult↗
PubMed1977

Glucagon levels in normal and diabetic subjects: use of a specific immunoabsorbent for glucagon radioimmunoassay.

Non-specific plasma effects may produce major errors in the estimation of true plasma pancreatic glucagon concentrations by radioimmunoassay. This has been circumvented by the production of glucagon-free plasma for each individual investigated, by means of glucagon antibody, coupled to sepharose beads. True fasting pancreatic glucagon levels (mean+/-SEM) in 18 healthy subjects (24+/-3 pg/ml) were significantly lower (p less than .005) than in 10 non-ketotic non-obese diabetics (38+/-3 pg/ml). It is suggested that, in the presence of decreased insulin-effect in the diabetic, this 55% glucagon elevation in diabetics may be of biological importance and contribute to the fasting hyperglycaemia.

Adult↗
PubMed1980

IgE levels in intestinal juice.

This investigation was performed to determine the possible significance of the IgE levels in intestinal secretions for the recognition of type I food allergy (immediate hypersensitivity). Four groups of individuals were studied and compared with each other: (1) healthy controls and patients with gastrointestinal disorders not affecting the small intestine; (2) patients with small intestinal disease; (3) patients with various manifestations of allergy but without food intolerance; and (4) patients with atopic sensitivity to foods. Despite the presence of proteolysis in the intestinal fluid, a statistically highly significant increase of the intestinal IgE level was observed in patients of group 4 with type I food allergy and in patients of group 3 as compared with normals. This was associated with an increase in the serum IgE level. An increased synthesis of the IgE in the lamina propria of the small intestine is most probable, but not yet adequately established.

Ancylostomiasis↗
PubMed1977

[Ferritin. Radioimmunological determination in serum and clinical significance (author's transl)].

Ferritin is an iron storage protein which has been shown to be present in blood serum only recently. An immunoradiometric determination of ferritin in 324 subjects with different iron stores is reported. In healthy men and women a ferritin concentration of 131 microgram/l (SD: 1,59) and 67 microgram/l (SD: 1,79) was found respectively. In male and female blood donors as well as patients with iron deficiency and iron overload significant differences of serum ferritin concentration could be demonstrated. In clinical practice the determination of serum ferritin is a valuable method for the estimation of body iron stores.

Anemia, Hypochromic↗
PubMed1977

Comparison of serum IgE determination by conventional radioimmunoassay (RIST) and by a modified (sandwich) technique (PRIST).

It has been reported that the sandwich technique (PRIST) is a more accurate method for determining serum IgE levels than the conventional radioimmunoassay (RIST), especially for low IgE levels. By using half the volumes prescribed for RIST and by introducing a 3-h preincubation step at room temperature, IgE values in the range of 30-4000 I.U./ml could accurately be established. It is concluded that the proposed modification may replace the conventional RIST for routine purposes, because it offers comparable accuracy, is more exonomical, and provides better results in the low IgE range. Discordant results between RIST and PRIST cannot be correctly interpreted, because interfering serum factors may cause either exaggerated IgE values with RIST, or falsely low values with PRIST.

Asthma↗
PubMed1977

Serum gastrin determination with a radioimmunosorbent technique.

A low utilization of antiserum has been reported in gastrin radioimmunoassay with a solid-phase procedure. As solid-phase immunoassays possess several advantages over their soluble counterparts for the assay of many hormones, a solid-phase radioimmunoassay for gastrin was examined. The results showed that this technique was suitable for gastrin determination without being wasteful to antibodies. Sensitivity and precision of the method were comparable to other investigations on gastrin immunoassay, as well as serum gastrin levels obtained for persons with no known gastro-intestinal disease, in patients with pernicious anemia and in patients with Zollinger-Ellison syndrome.

Adolescent↗
PubMed1977

Measurement of DNA-binding immunoglobulins in systemic lupus erythematosus.

A radioimmunoadsorbant assay for quantitating DNA antibody in the IgM, IgG, and IgA classes is described. The method was standardized allowing expression of results in absolute terms. Effects of rheumatoid factor on the results were investigated. The new assay was found to correlate well with the Farr assay for DNA antibody. Serum levels of DNA antibody in all three immunoglobulin classes reflected the degree of clinical activity of SLE.

Antibodies, Antinuclear↗
PubMed1982

A solid-phase fluoroimmunoassay for human IgE.

A fluoroimmunoassay (FIA) for the measurement of immunoglobulin E (IgE) is described. The method involves a sandwich technique in which antiserum to human IgE is adsorbed on a cellulose acetate/nitrate disc which is attached to a plastic StiQTM sampler. The prepared sampler is reacted with serum and antigen is bound specifically. After buffer wash and treatment with goat serum to block non-specific binding, the samplers are reacted with monospecific fluorescein conjugated antisera to human IgE. Two buffer washes remove unbound material and the fluorescence which is directly proportional to the IgE concentration is measured in a FIAX fluorometer. Assay standards range from 2 to 400 IU/ml. The method gives within run coefficients of variation (CV) from 3.3 to 8.4% and between run CV from 6.2 to 16.1% being less precise at low analyte concentrations. IgE concentrations of a group of 74 sera determined by FIA using StiQsTM prepared with antisera from 2 sources correlated well with results found by radioimmunoassay.

Animals↗
PubMed1994

Characterization of metabolically labelled antigen following immunoprecipitation with antibody bound on ELISA plates.

Immunoprecipitation is a powerful technique for the immunochemical characterization of antigens. In combination with sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) a number of features, e.g., presence of antigen, rate of synthesis, relative molecular weight of the polypeptide chain or post-translational modifications can be determined. Four different steps are basically involved in the immunoprecipitation procedure: (1) metabolic labelling of the antigen by incubation of viable cells with a radioactive precursor, (2) harvesting of the labelled antigen from the cells by lysis or in the case of secretory proteins from the supernatant, (3) formation and (4) purification of antibody-antigen complexes. The last step relies on secondary agents which bind to the antibody.

Animals↗
PubMed1977

Prostaglandin E in the secretions of allergic rhinitis.

Prostaglandin (PG) was extracted from nasal secretions of individuals with hay fever and from nasal washings of normal subjects. The extract was chromatographed in a silicic acid column and the purified PGE fraction was converted to PGB by alkaline dehydration. The PGB was then measured by a competitive radioimmunoassay with tritiated PGB1 and anti-PGB1 antibody, employing the double antibody technique. PGE was detected in the secretions of 6 of 12 hay fever patients and in the pooled normal nasal washings.

Adolescent↗
PubMed1981

Pharmacokinetics and pharmacodynamic effects of vaginal oestradiol administration from silastic rings in post-menopausal women.

Silastic rings releasing approximately 200 microgram of 17beta-oestradiol per day were inserted into the vaginas of 4 post-menopausal women for one to three 21-day periods. Plasma concentrations of oestrone and oestradiol were analysed by radioimmunoassay. The effect of circulating oestrogens on FSH, LH and sex-hormone binding globulin (SHBG) levels as the well as on the endometrium was studied. During the first 24 h of treatment the plasma oestradiol levels were higher than the oestrone levels. But during the following days of the 21-day periods, the levels of the two oestrogens were almost equal, varying between about 100 and 200 pg/ml plasma, a pattern similar to that seen in fertile women. the release of oestradiol from the ring gave stable plasma oestrogen levels. The FSH and LH levels were clearly depressed while the SHBG levels did not change. Characteristics of oestrogen influence were found in endometrial biopsies. The rings were well accepted and could be inserted and removed easily by the women. Absorption of oestradiol from the vagina is good and more complete than after oral administration allowing lower doses to be used for treatment.

Estradiol↗