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Biomedical subjects

H Ambrosius

Publications and source records attributed to H Ambrosius.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Characterization of a series of monoclonal antibodies against human T cells].

A set of 6 monoclonal antibodies is characterized reacting only with human T-cells but not with B lymphocytes. The antibody BL-T1 binds to the E receptor, being there on all mature T cells and on the majority of thymocytes. All respectively the majority of peripheral T cells but only subpopulations of thymocytes are recognized by the monoclonals BL-T2, BL-T3, BL-T4 and BL-T5. For identification and quantification of mature human T cells especially the antibody BL-T2 is suitable. The antigen recognized by BL-E1 is missing on peripheral B lymphocytes but expressed not only on T cells but also on erythrocytes, monocytes and a fraction of granulocytes. The monoclonals discussed are compared with the monoclonals for identification of leucocyte differentiation antigens (cluster of differentiation) characterized on the 1st Int. Workshop on Human Leucocyte Differentiation Antigens (Paris, 1982).

Animals↗
PubMed1984

[Antigen-specific rosette inhibition test with autologous serum--a possibility for the detection of blocking factors in chronic rejection of allogeneic orthotopic kidney transplants].

After allogeneic renal transplantation in 26 female pigs the kinetics of the immunological reactivity have been investigated in order to diagnose a rejection crisis. The animals were not treated with immunosuppressive substances. The antigen specific rosette test is an useful parameter for estimation of immune reactions against a graft. Moreover, the inhibition of this test by autologous serum taken in the course of a chronic graft rejection is caused by blocking factors. Therefore this inhibition test would be suitable for an exact determination of specific immune reaction against the graft. By exclusion of false positive results by means of the rosette reaction test a high significant correlation between the antigen specific rosette formation and the clinical symptoms of the rejection could be observed. As long as blocking factors are protecting the graft against activities of immunocompetent cells respectively their effector molecules, recipient serum is able to inhibit the rosette formation. On the other hand a strong increase of rosette forming cells in a pig whose serum does not show an inhibitory activity is correlated with clinical symptoms of a rejection.

Animals↗
PubMed1983

Evolution of low molecular weight immunoglobulins--III. The immunoglobulin of chicken bile--not an IgA.

Studies on comparison of antigenic relationships between the immunoglobulin of chicken bile--the so-called chicken IgA--and human, porcine, as well as murine IgA were performed by a series of double-antibody and solid-phase RIA systems using H chain-specific anti-chicken biliary Ig sera and alpha chain-specific anti-human IgA sera produced in rabbits and in carp. It was not possible to demonstrate a significant immunological cross-reactivity of the Ig of chicken bile to the Ig's of IgA class. Besides, we could not find an Ig type similar to this chicken biliary Ig in pooled normal sera or in the crude Ig fractions precipitated by (NH4)2SO4 of several vertebrate species (man, swine, buzzard, duck, goose, kestrel, kite, three tortoise species, frog, carp and perch); or in the bile of duck, goose, two snake species and frog. Only pooled chicken normal serum contained this biliary Ig type. Accordingly, the chicken biliary Ig can no longer be considered a precursor of mammalian IgA. This Ig of chicken bile represents a unique Ig class of birds and is to be called IgB (dominant biliary Ig of some birds).

Animals↗
PubMed1983

Kinetics and drug sensitivity of the anti-hapten and anti-carrier IgG1 and IgG2 antibody production in guinea pigs.

The influence of the hapten-protein ratio on the induction and kinetics of specific IgG1 and IgG2 anti-hapten and anti-carrier antibody synthesis, and the sensitivity of these reactions to cyclophosphamide (CY) and 6-mercaptopurine (6-MP), were studied following immunization with two different dinitrophenylated bovine gamma-globulin (DNP20-BGG and DNP47-BGG) conjugates in Freund's complete adjuvant (FCA) and drug treatment over the first 7 days after antigen injection. The DNP- and BGG-specific IgG1 and IgG2 serum antibody concentrations were determined weekly. Treatment by CY resulted in a complete suppression of the primary IgG1 and IgG2 anti-BGG antibody response, both in the DNP20-BGG and DNP47-BGG immunized guinea pigs. The anti-DNP response was completely suppressed only up to day 14 (DNP20-BGG immunized group) or day 21. This was followed by an increase that was significantly greater in the DNP20-BGG than in the DNP47-BGG immunized animals. The secondary IgG1 anti-BGG immune response induced by an injection of 1 mg BGG on day 86, was uninfluenced in animals immunized with DNP20-BGG but stimulated in the other group treated with DNP47-BGG. The IgG2 was completely suppressed in both groups. 6-MP, known to be less immunosuppressive in guinea pigs, led to very similar results. The finding that in animals immunized with DNP47-BGG the primary anti-BGG IgG2 antibody synthesis was uninfluenced by 6-MP, but the development of a memory was suppressed, would suggest that the primary antibody response and immunological memory are either separate mechanisms or have different sensitivities to 6-MP.

Animals↗
PubMed1983

[Employment of the antigen-specific rosette test in the diagnosis of rejection following allogeneic orthotopic kidney transplantation in the pig].

Investigations of the course were performed by means of an antigenspecific rosette test using a poolantigen from tissue samples of approximately 100 pigspleens with the help of the model of allogenic renal transplantation in 26 female pigs. The animals received no immunosuppressive treatment. In our study with this test 75% all of the rejection episodes by clinical acute and chronic rejection were predictably. In acute rejection a maximum rosette forming cell response was examined in general 2-3 days before a pathological rise of serum creatinine or in the course of a bad clinical state. Under chronic rejection this reaction can be seen 5-14 days before the kidney function will go poor. In spite of the high individuality of original curves statistical analyses indicate a good correlation of the number of antigenbinding cells toward pathological deviation of serum creatinine, as long as blocking factors not protect the transplant against the attack of persisting immunocompetent cells or their effectors. These blocking factors can be monitored in a rosette inhibition test with autolog serum.

Animals↗
PubMed1982

Glomerular immune complex deposition, circulating immune complexes, and antibodies in experimental insulinopenic diabetes.

Compared with control animals with a normal metabolism, rats with insulinopenic diabetes generally show an increase in glomerular deposition of complement-fixing immune complexes after immunization with bovine albumin and bovine gamma-globulin. Compared with the control group, the serum of the diabetic animals showed a reduction in the titers of IgM-isotype antibodies, which have a lower affinity. The concentration of the circulating immune complexes is the same. The increased frequency of glomular deposits in experimental diabetes can be explained by an increase in capillary permeability and by the formation of qualitatively different immune complexes.

Animals↗
PubMed1982

[Tolerance induction and production of anti-idiotypic antisera in carp].

Tolerance in carps can be induced by intracardial injection of 10-30 mg of ultracentrifuged human gamma globulin (HGGu), with strong individual variation being observable. Out of 21 carps pretreated with 10 mg HGGu, 10 animals showed 14 days after i.p. test immunization with 1 mg HGGu a log2 anti-HGG titre of 1.55 +/- 0.60 (control group - log2 7.33 +/- 1.47), while 11 animals exhibited a log2 titre of 7.45 +/- 2.75. Low doses of HGGu (0.01-1.0 mg) led to stimulation of immune response. If 1-2 mg of a human IgG myeloma protein are applied i.p. after intracardial injection of 10 mg HGGu either simultaneously or after a longer break, then a high-titre anti-idiotypical antiserum with low activity against HGG can be obtained in single cases. The experiments have shown wide individual variation in tolerance induction which may be due also to seasonal factors.

Animals↗
PubMed1982

[Extension of the rosette test in the estimation of TAA-binding cells in breast cancer and mastopathy patients].

The antigen specific rosette test was used for the evaluation of a specific sensibilization of a tumour bearer to TAA. The frequency of the rosettes formed by peripheral blood leucocytes of breast carcinoma patients with antigen-coupled particles is significantly higher than that produced by leucocytes of normal donors. Following operation normally the number of TAA specific rosettes decrease, in 4 cases with recidives we found high numbers of TAA binding cells. In another 11/98 patients following ablatio mammae later than half a year we found positive test results and also in 17/60 patients with mastopathy. The clinical relevance of these results must be proofed in further investigations.

Antigens, Neoplasm↗
PubMed1982

[Pre- and postoperative reactivity of breast cancer patients to tumor associated antigens and HEP in the macrophage electrophoresis mobility (MEM) test].

27 female patients with breast cancer and 23 with benign breast diseases have been investigated with the MEM-test. Antigens used in these experiments were human encephalitogenic protein (HEP) and 3M KC1 tissue extracts from carcinomas of breast and kidney. Preoperative examination of the patients showed an accuracy of the test of 89% (breast cancer extract) and 86% (HEP) respectively. The control persons gave less than 9% false positive tests. The results obtained with the extract from kidney cancer demonstrate the organ specificity (3% positive responses). Follow-up studies were carried out with cancer patients. We found, beginning with a delay, a strong decrease of reactivity 5 to 8 weeks after surgical treatment and later again increased reactivity in some patients. We suppose a relation between this restoration of MEM-reactivity and development of recurrent cancer whereby follow-up studies can get some clinical importance. The investigation of frequency distribution of MEM values obtained shows a division into low values of about 0% and high values of about 10% mobility inhibition without overlapping. The reasons are discussed regarding the levels of the patient and the test principle.

Antigens, Neoplasm↗
PubMed1982

Induction of immunological tolerance against sheep red blood cells in A/J mice by maternal immunization.

Female A/J mice were immunized with sheep red blood cells (SRBC) before mating and boosted a few days before delivery. The progeny of these mothers was immunologically tolerant against SRBC at the level of plaque forming cells (PFC). The state of unresponsiveness was antigen specific. Exchange of the newborn mice between control mothers and immunized ones shows clearly that the tolerance is induced by factors present in the milk or the colostrum, respectively. Some others findings suggest that antibodies of the mothers and not small amounts of the injected antigen are responsible for the nearly complete suppression of the immune response of the offspring.

Animals↗
PubMed1982

[Structural and functional characteristics of IgG1- and IgG2-antibody subclasses in the guinea pig. 2. Production and testing of specific antisera against IgG1 and IgG2-antibody subclasses and against Fc-, Fc'- and Fab-papain fragments of IgG2-antibodies in guinea pigs].

Rabbit antisera against specifically purified guinea pig IgG1 and IgG2 antibodies and against several papain-fragments of IgG2 were produced. These antisera were made specific by absorption with purified immunoglobulin of the other subclass and assayed for monospecificity by two immunological tests. In the macrophage rosette inhibition test, only the anti-IgG2 and the anti-Fab (IgG2) sera were effective. Inhibition of the rosette formation could be obtained at dilutions up to 1:100 or higher. Attempts to induce passive cutaneous anaphylaxis in the guinea pig skin after sensibilization with homocytotropic antibodies were evidently positive only with rabbit anti-guinea pig IgG1 serum. Anti-IgG2 and anti-IgG2 Fab sera revealed a positive reaction in higher concentrated forms (1:2 or 1:5 diluted) only.

Animals↗
PubMed1981

Comparison of the haemocytometer and tube modifications of the leucocyte adherence inhibition assay.

The haemocytometer and the tube modifications of the leucocyte adherence inhibition assay were compared in guinea pigs immunized with bovine gamma globulin or bovine serum albumin. In the direct test, both modifications yielded positive results. In the indirect test, which is dependent on a cell-free mediator of the lymphokine nature, the haemocytometer LAI assay only gave positive results. The factor produced by immune guinea pig lymphocytes and responsible for LAI reactions in the haemocytometer modification was also able to inhibit adherence of human and rat leucocytes, but not of mouse leucocytes. The results confirm the earlier suggestion that the tube and haemocytometer LAI assays have a different mechanism.

Animals↗
PubMed1981

The influence of cyclophosphamide and 6-mercaptopurine on the IgG1 and IgG2 immune response in guinea-pigs.

The purpose of this study was to investigate the effect of cyclophosphamide (CY) and 6-mercaptopurine (6-MP) on the production of the two IgG antibody subclasses in guinea-pigs. Following the intradermal application of dinitrophenylated bovine gamma globulin (DNP20-BGG) emulsified in Freund's incomplete adjuvant (FIA) each animal was given CY or 6-MP, 10 mg per kg of body weight per day on days 1--7, and the DNP- and BGG-specific anaphylactic (IgG1) and lytic (IgG2) antibodies were determined. Only treatment with CY resulted in a significantly-depressed IgG2 anti-DNP immune response; 6-MP was not suppressive and caused a prolonged IgG2 anti-DNP production. Both substances showed a stimulatory effect on IgG1 anti-DNP antibody formation. The carrier-specific IgG1 and IgG2 antibody levels were suppressed completely by CY but unaffected by 6-MP. After a booster injection of 1 mg BGG on day 86 the animals in the CY-treated group were not able to mount a secondary IgG2 anti-BGG immune response. In contrast, IgG1 anti-BGG production was strong and uninfluenced by CY treatment.

Animals↗
PubMed1981

[Immunological and immunotherapeutic studies on the model of mice following thermic injury ].

A burn toxin, which is discussed as reason of the burn disease by Schoenenberger et al., was isolated from burned skin of mice and the immunological reactions to this antigen were evaluated in burned mice longitudinally at several intervals after the trauma. We determined the specific antibodies against the burn toxin by means of the passive hemagglutination test, the burn toxin binding cells by means of the antigen specific rosette technique and the cell-mediated immunity using the macrophage electrophoretic mobility test (MEM-test). A rise of the burn toxin-specific cells could be observed with maximum at day 4 and a cell-mediated immunity between day 11 and day 13. Antibody titre was on the background about an interval of 3 weeks. Pretreatment with burn toxin or posttraumatic i. p. application of antibodies against burn toxin from rabbits eliminated primary death of mice with lethal burns. No correlation seemed to exist between the effect of treatment with antibodies and the antibody titre in the first days following burns.

Animals↗