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Biomedical subjects

F H Bach

Publications and source records attributed to F H Bach.

At least 469 records · Page 26Linked to original sources
PubMed1975

Secondary responses of human lymphocytes to alloantigens in vitro.

The secondary response of human lymphocytes following restimulation with alloantigens has been studied. If fresh stimulating cells are added to a mixed leukocyte culture (MLC) at a time when the peak of proliferative and cytotoxic activity has passed, a rapid reactivation occurs. The secondary response in MLC demonstrates specificity such that restimulation with the original sensitizing cell (or one presumably sharing the LD genetic determinants responsible for triggering MLC) induces a greater proliferative response than a third-party cell. On the other hand, the secondary cytotoxic response is directed towards the SD antigens of the original sensitizing cell regardless of which cell is used for restimulation. Possible mechanisms of cellular interactions are considered to explain these results.

Animals↗
PubMed1975

Predictive value of mixed leukocyte culture testing on allograft survival in unrelated dogs.

This study evaluated the mixed leukocyte culture (MLC) technique to quantitate differences in kidney allograft survival between unrelated animals. Each of five beagles received two heterotopic kidney allografts, one from a mongrel dog showing high MLC stimulation and one from a second mongrel dog showing a low MLC stimulation. Low or high stimulators were defined by the amount of radioactive thymidine incorporated by lymphocytes when the recipient was tested against a number of potential donors in one way MLC TESTS. Low and high stimulators usually differed by a factor of up to ten in the stimulation index. Recipients were given a standard treatment of asathioprine and prednisone. No special treatment was given for rejection episodes. Creatine clearances and periodic biopsies were used to determine rejection. Creatine clearances and biopsies showed the high stimulating kidneys to be rejected completely by the end of 2 weeks in all animals. All of the low stimulating kidneys maintained normal function for 3 weeks and then developed progressive deterioration and rejection over the next 3 to 6 weeks. These studies suggest that quantitation of the MLC may be predictive of kidney allograft survival in unrelated dogs.

Animals↗
PubMed1975

Genetic and cellular control of in vitro models of allograft reactivity.

In each species sufficently studied, a single genetic region, the major histocompatibility complex (MHC), controls the strong transplantation antigens. Recent evidence suggests that the genetic control of differences important in allograft phenomenon is more complex than previously realized. In addition to the two loci, alleles of which control serologically defined (SD) antigens, there are other loci the phenotypic products of which lead to T-lymphocyte activation in mixed leukocyte culture. These latter loci have been referred to as LD (or lymphocyte defined). There appears to be a physiologic interaction between these two loci in that the LD differences seem to be important in the initial recognitive phases of the allograft reaction; the SD differences (or products of genes very closely linked to those determining the SD antigens) are important as a target for cytotoxicity as studied by the cell-mediated lympholysis test.

Animals↗
PubMed1974

Genetic control of cell-mediated lympholysis in mouse.

H-2 congenic mouse strains were tested in vitro to investigate the genetic control of cell-mediated lympholysis (CML). Combinations were selected such that differences in various segments of H-2 could be examined for their ability to stimulate production of effector cells and to serve as targets for lysis. Particular emphasis was directed towards understanding the roles of LD and SD. SD-region differences are important in the sensitization of effector cells and they also function as strong targets for lysis, or as markers for the CML targets. LD differences are also important for sensitization of cytotoxic effector cells, but they serve only as very weak targets for lysis. Collaboration occurs between LD and SD in generation of CML. The nature of this interaction can be of two types: together LD and SD can produce CML which neither difference alone can stimulate; LD can enhance a CML response stimulated by SD-region differences alone.

Animals↗
PubMed1974

Role of H-2 lymphocyte-defined and serologically-defined components in the generation of cytotoxic lymphocytes.

The cell-mediated lympholytic capability of mouse spleen cells stimulated in mixed lymphocyte culture is determined by lymphocyte-defined (LD) and serologically-defined (SD) antigenic differences present during sensitization. Cells which are activated by LD differences alone are markedly less effective in causing lysis of target cells. This lack of cytotoxicity is shown to be, at least in part, due to the inability of LD differences to allow the efficient generation of cytotoxic lymphocytes. SD antigens not only serve as good targets for CML but are also shown to be important for the generation of cytotoxic lymphocytes during the mixed lymphocyte culture.

Animals↗
PubMed1973

Cell-mediated lympholysis. Importance of serologically defined H-2 regions.

The cell-mediated lympholytic capability of mouse spleen cells stimulated in mixed lymphocyte culture is related to the major histocompatibility complex genotype on target lymphocytes. The strain combinations AQR-B10. T(6R) and B10.A(4R)-B10.A(2R) that result in significant mixed lymphocyte culture activation do not mediate cell-mediated lympholysis on sensitizing target lymphocytes; serologically defined regions (H-2K and H-2D) are identical within each combination. H-2K or H-2D region disparity alone does not cause cell-mediated lympholysis. However after mixed lymphocyte culture activation as seen with B10.A-B10.T(6R), a target cell bearing only an H-2K region difference from the effector cell is sensitive to cell-mediated lympholysis. Likewise an H-2D region difference is an adequate target after mixed lymphocyte culture activation of the effector cell in the combination B10.A(2R)-B10.D2.

Animals↗
PubMed1973

Cell mediated immunity: separation of cells involved in recognitive and destructive phases.

The mixed leukocyte culture (MLC) and the cell mediated lympholysis (CML) assays are used as in vitro models of the afferent, or recognitive, and efferent, or destructive, phases of the homograft reaction. Activity in both of these tests has been related to differences at the major histocompatibility complex, HL-A in man and H-2 in mouse. Recent evidence suggests that the presumed cell surface differences which lead to cell proliferation in MLC are different from those which act as a target for CML. Data are presented providing further support for this hypothesis; in addition separate cell populations may respond to the differences which activate cells in MLC and to the differences which serve as targets for CML. There thus appears to be a dichotomy both for genetic control of, and cell populations involved in, the recognitive and destructive phases of cell mediated immunity.

Animals↗