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Biomedical subjects

U Lösch

Publications and source records attributed to U Lösch.

At least 73 records · Page 4Linked to original sources
PubMed1981

Course of serum-Ig concentrations in B12 chickens of the UM line.

The University of Munich chicken line ("UM") is isogenic in respect to the MHC and divides into normogammaglobulinemic, permanent and transient dysgammaglobulinemic individuals. Hence the immune defect is independent of the MHC. Continual analysis of the immunoglobulins until the 50th week of life revealed: one group of dysgammaglobulinemic individuals showed an initial IgG peak between the third and sixth week of life. Unusually high IgM and IgA levels occur in permanent and transient dysgammaglobulinemic individuals previous to the appearance of the IgG deficit and previous to a possible initial IgG peak. These high levels remain throughout the life of the chicken, possibly due to a missing negative feedback mechanism. Transient dysgammaglobulinemic chickens also exhibited increased IgM and IgA values after IgG normalization. Based upon our results, we postulate that the dysgammaglobulinemia defect is already preprogrammed during late embryonic development. The prevalence of a B or T-cell defect is still under discussion.

Animals↗
PubMed1981

Kinetics of delayed-type hypersensitivity (DTH) reactions and Ig levels in FCA-induced dysgammaglobulinemic B 12 chickens.

Kinetic studies on delayed-type hypersensitivity (DTH) to Freund's complete adjuvant (FCA) have been done in spontaneous dysgammaglobulinemic chickens, which have drastically reduced serum IgG levels and highly elevated IgM and IgA levels - in comparison to chickens with normal immunoglobulin (Ig) levels. For a period of five weeks, serum Ig levels, leukocyte migration inhibition (LMIT), and wattle reaction were examined once a week. In normal chickens, FCA treatment resulted in stimulation of IgG, but did not affect IgM synthesis, whereas in spontaneous dysgammaglobulinemic chickens, FCA stimulated only IgM synthesis. Spontaneous dysgammaglobulinemic chickens could produce LMIT and wattle reactions as well as normal birds. Whereas in normal birds, both types of DTH reactions declined continuously about the third or fourth week, in immunodeficient chickens, further increments of LMIT and wattle reactions up to the fifth week persisted as evidenced by LMIT and wattle reactions even 15 weeks after sensitization. In contrast, only minimal signs of reactivity were seen in normal birds. Spontaneous dysgammaglobulinemic chickens, nearly unable to synthesize IgG even after FCA stimulation in vivo, lack suppressive mechanisms regulating the course of DTH reaction to FCA. The possible B-cell nature of the regulatory cell population is discussed.

Animals↗
PubMed1980

Establishment of a B-compatible chicken line with normogammaglobulinaemia and dysgammaglobulinaemia (IgM/IgG).

A dysgammaglobulinaemic line of chickens homozygous at the major histocompatibility complex has been established. In these chickens the IgG levels are decreased 10 to 100 times and IgM levels are increased 2 to 10 times when compared to those of normal birds. Dysgammaglobulinaemia is genetically determined. No linkage with the major histocompatibility complex of the chicken has been found.

ABO Blood-Group System↗
PubMed1977

Recovery of the bursa of Fabricius in chickens after cyclophosphamide treatment: a histological study.

Chickens were injected posthatching with cyclophosphamide in three different doses (total 8, 10, 11 mg). Histomorphological analysis of bursal tissue was performed up to 11 weeks of age. A probable biphasic recovery was observed in the majority of the chickens. The first phase of recovery is characterized by the appearance of solitary thioninophilic cells in reticuloepithelial follicles, followed in a few follicles by a redevelopment similar to embryonal follicular genesis. The late phase of recovery starts from week 7 on by infiltration of reticuloepithelial follicles with mature plasma cells in the manner of a peripheral lymphoid organ followed by thioninophilic lymphoid cells. The latter cells populate the follicles successively. Different transitions to normal follicles then take place. These investigations confirm observations of a reconstitution of bursal compartments starting some weeks later than the recovery of thymus, which takes place 2 weeks after cyclophosphamide treatment.

Animals↗