ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The repopulation of the thymus was studied in mice after a potentially lethal dose of irradiation and injection of different numbers of syngeneic but chromosomally distinguishable bone marrow cells. The more bone marrow cells were injected, the earlier was the changeover from dividing host cells to dividing donor cells observed. At both 30 and 60 days after irradiation, the number of donor-derived T cells in the peripheral blood responding to phytohemagglutinin was directly proportional to the number of donor bone marrow cells injected, but the number of host-derived T cells was inversely proportional. Experiments in which mixtures of two syngeneic chromosomally distinguishable haematopoietic cell populations were injected after irradiation suggested that relatively small numbers of haematopoietic cells can be responsible for repopulating a single femur. Analysis of the thymus showed that the dividing cell populations within the thymus can also derive from very few precursor cells, possibly as few as one or two.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Peritoneal macrophages of F1hybrid mice injected with parental strain spleen cells 8–14 days previously (“early” graft-versus-host (GVH) macrophages) develop an increased ability to destroy in vitro bystanding target cells of syngeneic, allogeneic, and xenogeneic origin. At later stages of GVH reaction, the nonspecific cytotoxicity of macrophages wanes (“late” GVH macrophages) and does not differ much from that of control macrophages. Trypsinization of early GVH macrophages or iodoacetate treatment significantly reduces their cytotoxicity, whereas anti-&thetas; serum and complement have only a moderate effect. Antimouse IgM antibody significantly enhanced the cytotoxic potential of early GVH macrophages, but had no effect either on normal or late GVH macrophages. In contrast, antimouse IgG antibody enhanced, although slightly, only the cytotoxic activity of late GVH macrophages. Two possible explanations of the increased cytotoxicity of early GVH macrophages are offered: (1) cytophilic antibody of IgM type, directed against host antigens, renders macrophages capable of damaging nonspecifically bystanding target cells upon contact with antigen; (2) IgM alloantibody produced by parental cells changes the surface properties of macrophages and contributes to the cytotoxicity of these cells.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

By means of double diffusion in gel reactions, “heterophile” antibodies were demonstrated in human renal transplantation sera. Of thirty-two recipients of renal allografts, 12 (37%) had antibodies to extract of bovine erythrocyte stromata, and 5 (19%) of 26 recipients produced antibodies to extract of sheep erythrocyte stromata. These antibodies became detectable 1–6 months after transplantation and persisted for several months or years. However, the strength of reactions given by individual serum samples from the same recipient varied considerably. Sera from the same recipient gave a reaction of identity, while sera from two different recipients frequently gave reactions of partial identity or nonidentity. The antibodies reacting with bovine stroma extract were distinct from those reacting with sheep stroma extract. Evidence was also presented that the heterophile antibodies in transplantation sera are different from Paul-Bunnell antibodies in infectious mononucleosis sera. Some of the HL-A typing sera were shown to contain antibodies against bovine stroma extract. The antigen recognized by these sera in the bovine stroma extract was not related to any HL-A specificity. Three of eight rabbits which received skin and renal allografts formed antibodies against bovine stroma extract. Absorption studies clearly demonstrated that these antibodies are directed against antigens present in the donor's, but not in the recipient's tissues.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The Southeastern Regional Organ Procurement Program has developed a computerized system for the selection of organ transplant recipients. This system has proven to be a useful method for the rapid selection of histocompatible recipients for organ transplants from a large pool of potential recipients in a wide geographical area. In addition, the system provides a readily accessible source of data that can be used to analyze the relationship between histocompatibility and transplant survival.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Fifteen dog families were studied in mixed leukocyte culture. In eight families of seven different breeds, one-way nonstimulation in mixed leukocyte culture was observed. This could be explained by lymphocyte-defined (LD) homozygosity in most instances. In one family, an inclusion phenomenon was postulated, and in another, a deletion. LD homozygotes can serve as reference for LD typing and can also help elucidate the relative role of the LD locus for transplantation of organs.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

In confirmation of prior studies, fragments of testicular interstitial (Leydig) cell tumors from BALB/c mice were found to be transplantable to H-2d(BALB/c and DBA/2) or allogeneic H-2q(DBA/1 and BUB/BnJ) recipients after organ culture, whereas noncultured fragments were accepted only in H-2drecipients. Lymphocyte cytotoxicity assays showed that while transplantability was altered by the organ culture process, tissue immunogenicity in vitro was unchanged. Cell suspensions from the same tumor were also found to be transplantable to both H-2dand H-2qrecipients and occasionally even to H-2aand H-2krecipients, irrespective of whether the cells were obtained from fragments previously organ-cultured or from dispersed fresh tissue. We suggest, therefore, that rather than modifying cell surface antigens, it is possible that organ culture explanation serves to (1) allow free dispersal of the tumor cells which leads to progressive tumor growth, and/or (2) raise the ratio of dead to living cells in the transplanted fragments, which has previously been shown to direct host immune responses toward enhancement.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The mixed lymphocyte culture tests between one patient with acute lymphocytic leukemia and her mother and between another patient with aplastic anemia and his mother were found nonreactive, despite a one-haplotype difference for HL-A. Two crossovers in each family at the MLC locus or a specific defect in lymphocyte responsiveness could be possible explanations. The mother of each patient could be considered a potential donor for bone marrow transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Histocompatibility antigens have been solubilised from baboon spleen cell membranes by brief exposure to sodium deoxycholate (DOC). Preparations contained a high molecular weight species (DOCH-Ag) excluded by Sephadex Gr-200, and a low molecular weight species (DOCL-Ag) which eluted in the included fraction (molecular weight 46,000). The low molecular weight antigen was stable and was not sedimented by high speed centrifugation even after dialysis against a low molar salt solution. It elicited a delayed-type hypersensitivity response in sensitised baboons but not in normal animals. DOCL-Ag cultured in vitro with sensitised allogeneic lymphocytes produced a 1.3− to 24.9-fold stimulation, whereas when cultured with normal lymphocytes the maximum stimulation index was 2. Intravenous administration of donor DOCL-Ag (2 mg/kg) at the time of transplantation and without additional immunosuppression significantly prolonged the mean survival time of baboon liver allografts. The same treatment with donor DOCH-Ag did not prolong graft survival.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Mixed breed rabbit recipients of skin allografts from donors given an i.v. injection of cytosine arabinoside (CA) (200 mg) 12 hr before grafting had retarded graft rejection to 16.5 days, compared with a control of 12.5 days. Culture in Medium 199 for 12 hr before grafting slowed skin allograft rejection to 15 days, but the addition of CA to the medium produced no further delay of rejection. Donor pretreatment with CA (500 mg) significantly prolonged the life of renal allograft recipients who had been bilaterally nephrectomized to a mean of 14.7 days, compared with controls who had a mean survival of 11.7 days. The potential for cadaveric and perfused organ treatment with cytotoxic drugs to forestall rejection is supported by the present findings.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID