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Biomedical subjects

L Berrens

Publications and source records attributed to L Berrens.

At least 73 records · Page 4Linked to original sources
PubMed1979

Precipitating and non-precipitating complement consuming IgG subclass antibodies in pigeon breeders' disease.

The sera of patients with pigeon breeder's disease usually contain precipitating serum factors as well as human complement consuming factors as shown by incubation of the serum with pigeon dropping antigens. Although a single serum factor, possibly an IgG antibody, might account for both phenomena, affinity chromatography experiments revealed that the sera of patients with pigeon breeders' disease contain non-recipitating, human complement consuming, serum factors besides precipitating serum factors which are also capable of complement consumption. The non-precipitating serum factors most likely belong to the IgG3 immunoglobulin subclass, whereas the precipitating antibodies belong to the subclasses IgG1 and IgG2.

Alveolitis, Extrinsic Allergic↗
PubMed1979

Complement consumption in the diagnosis of pigeon breeders' disease.

Two laboratory techniques have been applied for the diagnosis and follow-up of pigeon breeders' disease, viz. detection of precipitins against specific antigens from pigeon droppings and assays of human haemolytic complement (huC) consumption by pigeon dropping antigens. A simple laboratory test of huC consumption by pigeon antigens is described, revealing high huC sensitivity in almost all sera of pigeon breeders with manifest or former disease. False-positive results were seldom observed. Discontinuation of antigen exposure and/or corticosteroid therapy had no effect on the huC consumption level in the test system, despite precipitin titres falling below the level of detection. Titration studies revealed an initial decrease of the huC-consuming serum factors, but titres settled at a definite constant level, even after antigen avoidance for many years. Combined application of both the precipitin test and the huC consumption test appears to be a good procedure for the laboratory diagnosis of pigeon breeders' disease.

Alveolitis, Extrinsic Allergic↗
PubMed1978

Reutilization of 125I-labelled anti-IgE antibody and paper discs in PRIST and RAST IgE determination.

In the paper radioimmunosorbent test (PRIST) anti-human IgE coupled paper discs are used for the estimation of total IgE in blood serum: in the radioallergosorbent test (RAST) allergen-coupled paper discs are used for the estimation of specific IgE in blood serum. The bound IgE or specific IgE is quantified by a 125I-labelled anti-human IgE. The non-bound 125I-labelled anti-human IgE can be collected and used in new assay. By a 4-h incubation of the used paper discs with 1 M glycine-HCl buffer (pH 2.7) the IgE-labelled anti-IgE complex can largely be removed. The paper discs treated in this manner can be used in a new assay.

Antibodies, Anti-Idiotypic↗
PubMed1978

Complement components in blood serum and suction blister fluid in erythropoietic protoporphyria.

Complement factor's C3c, C4, factor B, C3d and the immunoglobulin IgA were determined in suction blister fluid of patients with erythropoietic protoporphyria and in normal controls. The levels increased when the skin of the patients had been previously irradiated with 'white light', but with Kromayer radiation, and were interpreted as being the result of increased vasopermeability.

Adult↗
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

Inactivation of heamolytic complement by house dust allergen in the serum of children with atopic diseases.

Purified house dust allergen has been employed for screening the susceptibility to inactivation of haemolytic complement in the blood serum of atopic children and control subjects. Fluid phase complement in the control group of children was more sensitive to allergen-induced inactivation than observed in a normal adult population. Though the mean complement sensitivity indices in all groups of patients were below the valve for the control group, there was considerable statistical overlap. The serum complement sensitivities were in no way related to the clinical manifestations. The results of the complement test were not correlated to the total IgE levels, the RAST scores nor the skin reactions with house dust allergen. Some evidence for the in vivo involvement of the complement system in childhood atopic allergy was provided: the mean C3 proactivator level was significantly lower in atopic children, than in the control group; the mean C4 level in children with bronchial asthma and in children with atopic dermatitis was significantly depressed. A significant positive correlation between the serum C4 levels and allergen-complement sensitivities in children with both bronchial asthma and atopic dermatitis was observed.

Adolescent↗
PubMed1977

Animal dander allergy.

In a group of twenty-three atopic patients skin tests were performed with the dander allergens of horse, cat and guinea-pig, and with house dust and Timothy pollen allergens. A good agreement was observed between positive skin reactions and the results of RAST with these various allergens. In a number of cases, positive skin reactions were not related to the clinical histories. Likewise, positive RAST scores in several instances proved clinically meaningless. In patients with history-related skin reactions better correlation with RAST was observed. In such patients, skin reactions with photo-inactivated allergens remained strongly positive.

Allergens↗
PubMed1977

Specific and non-specific skin test reactions with animal dander extract.

Intradermal skin tests have been performed in atopic patients with allergenic extracts of different animal danders at uniform concentration. A high incidence of positive test was recorded which could not be related to the clinical histories, especially with the allergens of horse, cow and dog dander (NR). Better correlation was observed with guinea pig and cat allergens (R). The incidence of NR reactions was highest in the house dust allergy group of patients; with the exception of horse dander allergen, the frequency of R reactions was more pronounced in the grass pollen group. It is suggested that both allergen-specific and non-allergen-specific mechanisms may contribute to positive wheal and flare reactions.

Allergens↗
PubMed1977

Longitudinal studies of immunological parameters in Farmer's lung.

A group of patients with serum precipitins against M. faeni culture filtrate antigens and with clinically proven farmer's lung disease was examined. A group of precipitin-negative farmers with comparable antigen exposure and with unrelated forms of pulmonary disease served as control. Immunoglobulins G and A were elevated at first consultation in the majority of the acute cases of farmer's lung. Immunological parameters normalized during corticosteroid medication and antigen avoidance. Autologous complement (C) consumption by M. Faeni antigens proved valuable for diagnostic purposes. Despite normalizing immunological factors and subsiding symptomatology, C-consuming antibody levels remained constant.

Actinomycetaceae↗
PubMed1976

Comparison of serum IgE determination by radioimmunoassay and by single radial immunodiffusion.

Two commercially available methods of total serum IgE determination have been evaluated, viz: the radioimmunosorbent test (RIST) and the assay by single radial immunodiffusion (RID). RIST was found a suitable and rapid method for the wide range of IgE concentrations to be expected in the sera of an allergic population. The RID method has a lower limit of detection of about 1000 I.U./ml; over this value, both techniques provided statistically correlated results. However, for technological reasons RID was considered less suitable for routine application.

Asthma↗