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Biomedical subjects

L Berrens

Publications and source records attributed to L Berrens.

At least 91 records · Page 5Linked to original sources
PubMed1976

Complement component profiles in urticaria, dermatitis herpetiformis, and alopecia areata.

Insignificant variation was noted in the mean levels of the complement components CIQ, C4, C2, C3, C5 and C3PA between various groups of sera from patients with urticaria, angio-oedema, dermatitis herpetiformis, alopecia areata, or hay fever. No deficiencies were found. Elevated C9 levels in chronic urticaria and angio-oedema reflected its nature as an acute phase protein. The assessment of C components in single or sequential serum samples revealed only marginal variations. Similar results were recorded for plasminogen the immunoglobulins, G, A and M. Some evidence is provided for the primary involvement of the kallikrein-kinin system in urticaria.

Alopecia Areata↗
PubMed1976

Inactivation of hemolytic complement in human serum by an acylated polysaccharide from a gram-positive rod: possible significance in pigeon-breeder's disease.

In an attempt to identify the major complement-consuming heteropolysaccharides in pigeon excreta, a number of teichoic acids and lipoteichoic acids from gram-positive bacteria were examined as possible substitutes. Teichoic acids from the cell wall and membrane of Lactobacillus buchnerii were found suitable. Samples of freshly voided pigeon droppings were cultured under anaerobic conditions and the bacteria were identified, subcultured, and extracted with phenol-water. Cell wall and membrane antigens from isolated Lactobacillus species could replace pigeon excreta antigens in diagnostic complement consumption tests. Purification and chemical characterization indicated the major antigen from Lactobacillus in this respect to be an acylated heteropolysaccharide.

Animals↗
PubMed1976

The atopen: a rehabilitation.

Consideration of the physicochemical and biological properties of the common inhalant, food and nematode allergens has led the author to propose reintroduction of the term atopen. Atopens are nonspecific activators of physiological enzyme systems in man and are indicators of the atopic status. Allergens are considered to be those substances, not necessarily immunogenic by themselves, capable of deliberately directing the immune response into IgE production. Ongoing IgE synthesis may eventually produce IgE antibodies reacting with nonallergenic antigens.

Allergens↗
PubMed1975

[Allergy to house-dust as a model of nonspecific hypersensitivity].

A general survey is given of the chemistry and properties of the allergens causing bronchial asthma, eczema, and hay fever in "atopic" patients. The carrier molecules of, for example, the ubiquitous house-dust allergens are chemically unrelated structurally, though various allergens incorporate common structural sites of lysine--sugar conjugation. These sites probably activate a multi-enzyme system mediating allergic reactions and involving components of human complement. This process is non-immunological; the proposal is made that this mediator system is intrinsically more sensitive to nonspecific stimulation in allergic persons.

Allergens↗
PubMed1975

Laboratory diagnosis of the atopic condition: evaluation of a possible method based on human serum complement consumption.

Purified house dust allergen has been employed for screening the susceptibility to inactivation of haemolytic complement in the blood serum of atopic individuals and control subjects. Though the atopic sera displayed a tendency to higher susceptibility, no practical distinction was possible from the sera of patients with various forms of chronic pulmonary disease, extrinsic allergic alveolitis, or urticaria. CH50 and C4 levels were unrelated to allergen-sensitivity of haemolytic complement, nor was there a correlation with the titers of naturally-occurring sheep red cell haemolysins. Although blood group specificity within the ABO system was distributed over the patients as expected for the normal population, the titers of A- and B-type antibodies displayed a trend to correlate with the allergen-sensitivity of fluid phase complement.

ABO Blood-Group System↗
PubMed1975

Blood group activity of allergenic preparations.

Haemagglutination-inhibition studies showed that several different allergenic preparations exhibit A and B blood group activity. Most products displayed A-specificity, less often B-specificity; the inhibition titers were usually low. No correlation was evident between isoagglutination-inhibition titers and the complement-consuming capacity or skin-reactivity of the allergens. Absorption of A- and B-isoagglutinins from human serum did not affect the complement consumption by house dust allergens. Hapten-inhibition studies confirmed the non-participation of blood group antibodies in allergen-induced complement consumption. The observed inhibition by D-glucosamine is attributed to a partial structural homology with the lysine-sugar site on house dust allergens.

ABO Blood-Group System↗
PubMed1975

A controlled study of allergen production in cultures of Dermatophadoides pteronyssinus.

Allergenic substances have been isolated from cultures of Dermatophagoides pteronyssinus on wheat germ flakes and powdered yeast; as controls, non-sterile nutrient medium containing no mites, as well as sterile medium, were maintained and extracted under identical conditions. Chemical purification and analyses indicated the occurrence of skin-active allergens in all three preparations. This was confirmed by the assay of skin-reactivity in vivo and complement-inactivating capacity in vitro. Quantitatively, the medium containing bacteria and fungi contained more allergen than the sterile control, but less than the mite-infected medium. The evidence indicates that degradation reactions of nutrient components proceed faster in the non-sterile media than in the sterile control. The results of immunochemical analyses demonstrate that degradation reactions, give rise to the introduction of lysine-sugar structures inot high-molecular weight components from the medium. It is concluded that mites and micro-organisms have a role in allergen formation by promoting degradation reactions among nutrient constituents.

Allergens↗
PubMed1975

Value of fluid phase complement consumption as a means of 'in vitro' allergen standardization.

Atopic allergens can readily be shown to inactivate hemolytic complement in human serum. This property has been explored as a means of in vitro allergen quantitation and standardization. The purification of house dust allergen, guided by skin tests and complement inactivation, demonstrates that the in vitro technique is clinically relevant. Since human sera differ in their sensitivity to complement inactivation by allergens, it is desirable to prepare a purified house dust allergen as a standard. By referring to this standard, other house dust extracts may then be standardized by using any given serum sample of human origin, provided that such extracts have undergone some degree of purification. Kinetic studies demonstrate that other allergens of the house dust group may be standardized in similar fashion; it was noted that the ratio of the complement inactivating powers of these respective allergens remains constant whatever the serum used. The method is not suited for the quantitation of pollen allergens.

Allergens↗
PubMed1975

Enzyme activation and inhibition induced by cold provocation in a patient with cold urticaria.

A 33-year-old female patient with acquired cold urticaria, together with her 8-year-old healthy daughter, was subjected to a brief period of cold exposure. The effect of this treatment upon a number of key factors of the plasma coagulation, kallikrein and complement systems was investigated. Cold air provocation caused increased fibrinolysis, together with a measurable consumption of the protease inhibitors alpha1-antitrypsin (alpha1AT), alpha2-macroglobulin (alpha2M) and C1Inactivator (C1INA). Kaolin activation of the patient's plasma elaborated exceptionally high levels of esterolytic activity, both before and after cold exposure, indicating pre-enzyme lability. Both subjects had abnormally high serum ratios alpha2M/alpha AT. Impressive leucocytosis was observed in the symptomless child.

Adult↗
PubMed1975

Physicochemical and immunochemical quantitation of house dust allergens.

House dust extracts for clinical use must be purified in order to free them from indesirable irritants and pyrogens. A discussion is given of practical and simple methods for the standardized production of purified house dust allergens, which can be quantitated on the basis of relatively simple analytical and physicochemical parameters. Immunoelectrophoretic analysis may help in the controlled production of safe and potent preparations. In contrast, elaborate standardization by quantitative single radial immunodiffusion with anti house dust sera may lead to completely erroneous results.

Allergens↗