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Biomedical subjects

W Müller-Ruchholtz

Publications and source records attributed to W Müller-Ruchholtz.

At least 181 records · Page 10Linked to original sources
PubMed1979

B cell activity in rat bone marrow and spleen during primary and secondary response: dependence on strength of antigen.

B cell activity was studied in the spleen and the bone marrow of inbred rats after applying xenogeneic erythrocytes of different antigenic strength (mouse or sheep). The hemolytic plaque technique of Cunningham was used. In contrast to the studies of other authors with other species, these experiments showed that in the rat the kinetics of IgM and IgG responses in bone marrow and spleen are principally similar during a primary as well as during a secondary reaction, varying only with the strength of the antigen.

Animals↗
PubMed1979

Comparison of the immunologic reactions of arterial transplants in the arterial system and of venous transplants in the venous system using inbred strains of rats.

(1) Arterial transplants used as arterial replacements induce sensitization of the recipient in the weakly as well as in the strongly allogeneic systems (afferent limb). (2) Venous transplants used as venous replacements induce sensitization of the recipient (afferent limb). (3) Arterial transplants show increasingly severe rejection reactions paralleling the degree of immunogenetic difference (efferent limb). (4) Veins transplanted as venous replacements are tolerated even in the strongly allogeneic systems (efferent limb).

Animals↗
PubMed1978

Allogeneic corneal grafting in inbred strains of rats. Histology of graft reaction.

Histological studies of interlamellar keratoplasty in different inbred strains of rats (CAP, LEW) without additional sensitization--i.e. first-set reactions--are described. The corneas of 65 eyes, after allogeneic or syngeneic grafting, were examined from the 3rd to the 90th day--every 2nd day at the beginning of the reaction and later every 5th day. After syngeneic grafting (LEW leads to LEW) a non-specific healing-reaction (only slight vascularization of the graft bed, edema, granulocytic infiltration) reached its climax on the 6th day and subsided by the 10th day. After allogeneic grafting (CAP leads to LEW; RtH-1-incompatible) the non-specific-healing reaction progressed into a second phase, namely the specific reaction: increasing infiltration of the host cornea and the graft with small lymphocytes, blast cells and macrophages, directly followed by severe vascularization, reaching its climax about the 14th day. A third, phagocytic phase succeeded the infiltration leading to elimination of the donor cells, but leaving the donor stroma undamaged. All these alterations had almost completely disappeared after 35 days. Thus, the corneal allograft reaction is discussed as a typical immunological reaction leading to the destruction of transplantation-antigen-bearing cells and permitting observation of the different reaction phases more clearly than in most other tissues.

Animals↗
PubMed1978

[Evaluation of the antigenicity of heart valve leaflets using inbred rat strain combinations (author's transl)].

Experiments with large, non-inbred animals yield no reliable evidence in the antigenicity of heart valves. With inbred strains of rats, however, it is possible to obtain evidence on the immunological reactions of heart valve leaflet transplants. Our experiments were undertaken on the inbred rat strains (CDR, LEW, CAP and BD5, using combinations as follows: syngeneic strain combination (CDF leads to CDF), weakly allogenic (RtH-1-identical) strain cimbination (LEW leads to CDF), strongly allogeneic (RtH-1-incompatible) strain combination (CAP leads to CDF). Strain BD5 was used for the control skin grafts. Either one or two heart valve leaflets were heterotopically intra-aortally transplanted. Sensitization was verified humorally by transplantation antibody titers and cellularly by subsequent donorspecific skin transplants. The following results were achieved: Allogeneic heart valve leaflets are antigenic. Intravascular grafting of one heart valve leaflet induces the same degree of sensitization as the grafting of two leaflets. In the RtH-1-identical system, sensitization is revealed only by subsequent skin grafting, whereas in the RtH-1-incompatible system, sensitization is humorally demonstrated as well. This indicates that in heart valve leaflet transplantation cellmediated reactivity is a more sensitive indicator than the humoral one. The greater the immunological difference is, the clearer the sensitization will be. In the strongly allogeneic system, the sensitization is even demonstrated humorally; skin grafts are rejected as "white grafts". Improved long-term results may be expected in allogeneic vital heart valve transplants if consideration is given to the HLA compatibility between donor and recipient; the appearance of delayed insufficiency could be greatly lessened or even deferred.

Animals↗
PubMed1978

Studies on the antigenicity of vital allogeneic valve leaflet transplants in immunogenetically controlled strain combinations.

The use of defined inbred strains of rats enables reproducible experimentation on the antigenicity of heart valve leaflet transplantation. The inbred strains CAP, F344, and LEW were used as syngeneic, weakly allogeneic (RT-1-identical) and strongly allogeneic (RT-1-incompatible) strain combinations. After heart valve leaflet transplantation, humoral and cell-mediated immune responses were investigated. The results were: (1) Allogeneic heart valve leaflets are antigenic. (2) Just one heart valve leaflet, applied intravascularly induces sensitization of the recipient. (3) In the weakly allogeneic system, sensitization is only revealed by donor-specific skin transplants, while in the strongly allogeneic group, sensitization is demonstrated humorally as well. (4) The greater the immunogenetical difference, the sooner sensitization appears. In the strongly allogeneic system, skin transplants were rejected as "white grafts".

Animals↗
PubMed1978

Different suppressive effects of combined cyclophosphamide-antigen treatment compared with exclusive cyclophosphamide treatment on primary and secondary humoral immune reactivity.

The immunosuppressive effect of a combined treatment with antigen (C3H erythrocytes - ME) and cyclophosphamide (CY - dosage 65% LD50) has been studied in inbred CAP rats showing different degrees of immunological reactivity. When primary reactivity existed before treatment, this reactivity was not abolished but diminished. When weak secondary reactivity (after one antigen injection) existed before treatment this reactivity was abolished and again diminished primary reactivity was found. When strong secondary reactivity (after 4 antigen injections) existed before treatment selective unresponsiveness was found during the 4 weeks following treatment. 12 weeks after treatment diminished primary reactivity was found again. When the same dose of CY was given without antigen no immunosuppressive effect could be seen - irrespective of whether primary, weak or strong secondary reactivity existed. The results indicate that in this model it is easier to induce selective unresponsiveness in sensitized than in nonsensitized rats and suggest that primed lymphocytes are more susceptible to a combined antigen-CY treatment than unprimed cells.

Animals↗
PubMed1978

[Significance of the hemodynamics for the extent of the rejection. Comparison of immunological reactions in artery transplantation in high pressure and vein transplantation in low pressure systems in matching inbred rat strain combinations].

Systemic sensitization is induced by arterial transplants in the high pressure system and by venous transplants in the low pressure system. In aorta transplantation the severity of the rejection corresponds directly to the immunogenetic differences between donor and recipient; the efferent limb is triggered into action. For application of allogeneic veno-venous transplants this is not the case: despite systemic sensitization, even strongly allogeneic venous transplants are maintained over long periods. A threshold value is not reached unless there is presensitization with strong antigens, after which morphologically comprehensible rejection reactions, i.e. round cell infiltration, are demonstrated even in veno-venous transplants.

Animals↗
PubMed1977

Analysis of the antigenic structure of the thymocyte surface membrane by heterologous anti-thymocyte serum.

The surface membrane of rat thymocytes and lymph node cells was analyzed by comparing the capability of different rat cell types and of solubilized and chromatographically separated rat thymocyte membrane fractions to absorb cytotoxic antibodies on rat thymocytes and lymph node cells from a heterologous anti-rat thymocyte serum. The experiments described cause distinct antigenic specificities of the thymocyte membrane to be brought into relationship to structures of defined physio-chemical properties, and thus are an approach of a thymocyte cell surface mapping in antigenic as well as in molecular terms. Futhermore, the data presented allow conclusions on the distribution pattern of single antigenic determinants on different cells or tissues used as absorbents and target cells.

Animals↗
PubMed1977

Microcytotoxicity test in allograft immunity: specificity and kinetics of effetor T cells.

To obtain further insight into the informatory possibilities of the Takasugi-Klein microcytotoxicity test (MCT), mouse spleen cells were prepared after a single immunization with 5 X 10(7) H-2 incompatible cells and tested for reactivity against mouse fibroblasts. The following three aspects were investigated: (1) Specificity of the reaction: various mixtures of different target cells revealed absence of innocent bystander kill even after 48 h test incubation. (2) Kinetics of the reactivity after short-term (20 h) or long-term (48 h) incubation: the former disappeared rapidly, whereas the latter remained detectable beyond day 60 after immunization. This suggests the activity of different cells: an early killer cell and a later increasingly dominating effector cell which requires long-term incubation with the target. (3) Characterization of the effector cells: anti-theta-serum treatment abolished MCT reactivity completely at early and late stages after immunization. Nylon wool effluent (T-enriched) spleen cells were absolutely more active after short-term but became relatively less effective after long-term incubation as compared to nonseparated spleen cells, suggesting a higher adhesiveness of the cells which operate the 48 h reaction. The findings may demonstrate the usefulness of the MCT for in vitro studies on presence and behavior of different cells involved in allograft immunity in vivo.

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