PubMed Health⌕ Search

Biomedical subjects

G P German

Publications and source records attributed to G P German.

At least 19 recordsLinked to original sources
PubMed1992

[The structure of carbohydrate chains of human IgG4-paraproteins differing in the ability to bind cell receptors].

Comparative oligosaccharide analysis by HPLC revealed structural differences in the carbohydrate chains of human IgG4 paraproteins, varying in ability to induce the rhesus monkey's passive skin anaphylaxis. An atypical IgG4 paraprotein, which is inactive in this reaction and also does not bind the IgG4-subclass specific monoclonal antibody IH2, has a much higher proportion of the carbohydrate chains lacking terminal galactose residues than two typical IgG4 paraproteins. This structural feature may be one of the reasons for the atypical IgG4 not to bind by the mast cell Fc gamma receptor.

Animals↗
PubMed1992

[A simple method of isolating monoclonal immunoglobulin M, possessing rheumatoid activity].

A simple procedure for obtaining highly purified preparations of native monoclonal (Waldenström's disease) immunoglobulin M possessing a rheumatoid activity (IgM-RF) has been developed. The method is based on the use of affinity chromatography with a new readily available adsorbent (immunoglobulin G-porous glass) and 3 M LiCl in Tris-buffer pH 8.3-8.4 able to induce the dissociation of the IgM-RF-IgG complex. The IgM-RF preparation thus obtained was characterized in terms of amino acid composition (relative to conventional monoclonal IgM), carbohydrate composition and structure of oligosaccharide moieties of a complex type. It was shown that some dissociation conditions for the IgM-RF-IgG complex routinely used to isolate IgM-RF provoke irreversible denaturation of IgM-RF when applied to a preliminarily purified complex.

Amino Acids↗
PubMed1990

IgG4 antibodies in hay fever patients. Difference in IgG4 response to tree pollen and grass pollen allergens.

Total IgE and IgE and IgG4 antibodies to offending allergens were studied in 118 hay fever patients allergic to tree pollen and grass pollen allergens. No difference in the level of total IgE and IgE antibodies was found between these two groups while the IgG4 antibody level was significantly higher in tree pollen allergic patients. It is suggested that the IgG4 antibodies to tree pollen allergens can be stimulated by structurally related allergens of vegetable food and are probably involved in tree pollen-associated food hypersensitivity.

Adolescent↗
PubMed1990

[IgG4 antibodies to the allergens of grass and tree pollens in pollinosis patients: their diagnostic and prognostic significance].

Total IgE, IgE and IgG4 antibodies to offending allergens were studied in 118 hay fever patients with allergy to tree pollen or to grass pollen. No difference in the level of total IgE and IgE antibodies was found between these groups of patients while the IgG4 antibody level was significantly higher in tree pollen-allergic patients. It has been established that in tree pollen allergy, the determination of IgG4 antibodies is of no less diagnostic value than the assay of IgE antibodies. The authors discuss the problems of the prognostic value of IgG4 antibody increase during the hyposensitization therapy and of a possible relationship between IgG4 antibodies and allergy to vegetable food often associated with tree pollen allergy.

Allergens↗
PubMed1990

[Local immunity in pathology of the IgA system (IgA subclasses in the saliva of patients with A-paraproteinemia)].

In 39 patients with A-paraproteinemia, the local immunity status was estimated according to the level of IgA subclasses in the saliva and antibody activity of secretory IgA to E. coli and S. Sonnei. Local production of normal IgA was undisturbed only in 12 patients with A-paraproteinemia, since in the saliva of those patients, there was a normal correlation of IgA subclasses and the level of antimicrobial IgA antibodies was the same as in healthy persons. The overwhelming majority of the patients with A-paraproteinemia and all the patients suffering from heavy alpha-chain disease manifested deficiency of local production of normal IgA, which consisted in the impairment of the normal correlation of IgA subclasses in the saliva and in the reduction of sIgA function. A-paraprotein was detected in many samples of the saliva using agar electrophoresis followed by immunoblotting. Secretion was shown to be mainly penetrated by the polymeric forms of A-paraprotein.

Antigens, Bacterial↗
PubMed1988

[Determining the level of the rheumatoid factor associated with polyclonal and monoclonal human serum IgA].

The authors studied the activity of the rheumatoid factor (RF) associated with polyclonal and monoclonal IgA contained in the sera of patients with chronic diseases of noninfectious etiology and A-paraproteinemia. IgA-RF-activity was determined by an enzyme immunoassay. In most of the patients' sera IgA had a high level of RF-activity. The frequency of RF-activity detection did not depend on the level of polyclonal IgA but correlated with the level of monoclonal serum IgA. During a study of the chromatographic fractions of sera containing monoclonal IgA, RF-activity was mainly revealed in the fraction of IgA polymers; IgA monomers forming the bulk of serum IgA, demonstrated no RF-activity. The inclination of curves reflecting the correlation between the level of IgA-RF and dilutions of tested sera made it possible to assess function of the affinity of such molecules which was growing with an increase in IgA molecular mass.

Antibodies, Monoclonal↗
PubMed1985

[Isolation of antisera to different IgA determinants and an analysis of the antigenic structure of human monoclonal IgA].

Different molecular forms and subclasses of monoclonal IgA, identified by the method of electrophoresis in acrylamide gel with sodium dodecyl sulfate, were used as antigens for immunization and as adsorbents for the production of antisera to various IgA subclasses and to Fc alpha, Fab alpha and P-determinant of IgA. The antisera thus prepared were used for the analysis of the antigenic structure of monoclonal IgA. True IgA polymers and monomers were detected in the precipitation test with antiserum to P-determinant; in some cases monoclonal IgA synthesized by a single clone of plasmatic cells consisted of IgA monomers and polymers, equally capable of binding free SC in vitro. The results of the determination of IgA sub-classes with the use of antisera to IgA1 and IgA2 coincided with the distribution of subclasses established by the study of these proteins in polyacrylamide gel with sodium dodecyl sulfate. The antisera obtained in these investigations made it possible to detect three cases of heavy alpha-chain disease and to characterize the antigenic structure of protein occurring in this disease.

Antibodies, Monoclonal↗
PubMed1985

[IgA protease activity of microbes in the genus Bordetella].

Monoclonal IgA paraproteins of subclasses 1 and 2, isolated from the sera of myeloma patients, were incubated for 4, 24, 48 and 72 hours with B. pertussis, B. parapertussis, B. bronchiseptica cultures, as well as Haemophilus influenzae strain. The fragmentation of IgA was studied by immunielectrophoresis with antisera to alpha-chain, to Fab alpha + Fc alpha, to Fab alpha and with antisera to light chains corresponding to the type of paraprotein. B. pertussis and B. parapertussis were found to have subclass-unspecific IgA protease which splitted off a cathode fragment, similar to Fab-fragment and, probably, corresponding to the variable domain of alpha-chain (Fv), after 48-hour incubation. Similar IgA protease was detected in H. influenzae, found to have classical IgA1 protease as well. All Bordetella species under study splitted off anode components from IgA paraproteins of both subclasses. These components, containing the determinants of heavy and light IgA chains, were either IgA - alpha I-antitrypsin complexes or some IgA fragments with high electrophoretic motility. None of the strains under study splitted monoclonal IgG.

Antibodies, Monoclonal↗
PubMed1985

[Serum and secretory immunoglobulins in allergic diseases].

A total of 158 patients with pollinosis, bronchial asthma, urticaria and Quincke's edema were examined. The immunoglobulin and C3 levels in sera and the immunoglobulin and albumin levels in saliva were determined by the method of single radial immunodiffusion with the corresponding monospecific antisera. In all the groups of patients subjected to examination the presence of polyclonal hypergammaglobulinemia was detected, which was manifested by a rise in the levels of IgG, IgA and especially IgM; the level of IgD was low. A decrease in the level of C3 was detected in pollinosis patients in the absence of the exacerbation of the disease. No circulating immune complexes were detected. An essential increase in the level of IgG in saliva was revealed, which was due to the local synthesis of this immunoglobulin. In winter the level of salivary IgA in pollinosis patients was found to be essentially below normal, but at the period of exacerbation it increased twofold, probably in response to local stimulation with antigen-allergen. Patients with bronchial asthma and pollinosis were found to have a high level of free secretory component (SC); in pollinosis the level of free SC sharply increased during the stage of exacerbation, which was due to the increase of its synthesis and secretion by the epithelial cells of the mucous membranes. The importance of these data for the pathogenesis of allergic diseases are discussed.

Adolescent↗
PubMed1984

[IgD/kappa myeloma].

The authors provide a description of clinical, immunological and immunochemical studies in a patient with IgD/kappa myeloma which is a rare immunochemical disease pattern. Based on the available reported data and the case report it is concluded that this immunochemical disease pattern has a more favourable course than IgD/lambda myeloma.

Adult↗
PubMed1984

[Comparative analysis of systemic and local immunity in selective IgA deficiency].

The levels of serum and salivary immunoglobulins and serum antibodies to 5 different antigens (diphtheria toxoid, Escherichia coli and Shigella sonnei O-antigens, bovine serum albumin and ovalbumin), as well as heterohemagglutinins , were studied in 29 persons with complete or partial IgA deficiency. In 27% of cases an increase in the level of serum IgA was observed, such increase occurring more frequently in complete than in partial IgA deficiency. A rise in the level of serum antibodies, especially those to alimentary and enterobacterial antigens, was established; the degree of this rise was not correlated with the degree of disturbances in the systemic synthesis of IgA. In complete IgA deficiency not only serum, but also salivary IgA was absent; in some cases saliva contained no secretory component as well. In partial IgA deficiency the level of salivary IgA was normal. The characteristic features of systemic and local immunity in a varying degree of disturbances in the synthesis of IgA are discussed.

Adolescent↗
PubMed1983

[Immunochemical determination of human lactoferrin].

The immunochemically pure preparation of lactoferrin was isolated from human colostrum and used for the immunization of animals with a view of obtaining antiserum, and also as a reference preparation for the determination of the content of lactoferrin in the standard. The monospecific antiserum to lactoferrin, obtained as the result of this procedure, was used for the determination of the content of lactoferrin in samples of human milk by the method of radial immunodiffusion. Through the content of lactoferrin in human milk showed considerable fluctuations, its level essentially decreased on the second week of lactation. In cases of the microbial contamination of milk the tendency towards an increase in the content of lactoferrin was observed irrespective of the time of lactation.

Animals↗
PubMed1981

Immunodiagnosis of IgD multiple myeloma. A report of 17 cases.

The present report summarizes the main clinical and immunochemical features of 17 patients with IgD myeloma and compares than with the evidence reported in the literature. The difficulties inherent in the immunodiagnosis of this disease, particularly in detection of the M-component, typing of IgD and demonstrating its monoclonal nature, are discussed on the basis of personal observations and those of other investigations. Special emphasis is placed on clinical and immunochemical characteristics of IgD kappa myeloma. Immunoquantitation of serum IgD is considered to be the most reliable method of immunodiagnosis.

Bence Jones Protein↗