Search PubMed⌕ Search

Biomedical subjects

F T Rapaport

Publications and source records attributed to F T Rapaport.

At least 145 records · Page 8Linked to original sources
PubMed1981

Long-term study of vascularized free-draining intraperitoneal pancreatic segmental allografts in beagle dogs.

The purpose of the present study was to evaluate the significance of immunogenetic factors on the survival of pancreatic allografts in beagle dogs. Donors and recipients were leukocyte antigen (DLA)-typed and mixed lymphocyte culture (MLC)-tested. Recipients were made diabetic by total pancreatectomy and immediately implanted intraperitoneally with a vascularized, free-draining (duct unligated) pancreatic segmental (FDPS) allograft. Two groups of dogs were studied. In group I consisting of donor-recipient littermates, recipients were immunosuppressed with prednisone and azathioprine (n = 16 dogs), or not immunosuppressed (n = 4). In group II, recipients were made specifically unresponsive by total body radiation, autologous marrow implantation, and kidney transplantation from DLA-MLC identical donors, 1 yr before FDPS transplantation from the corresponding original kidney donors. Survival of the FDPS grafts in group I was inversely related to pretransplant MLC reactivity, irrespective of DLA genotyped match between donor and recipient. Thus, immunosuppressed high MLC reactors (n = 8) rejected FDPS grafts between 7 and 14 d, whereas immunosuppressed low MLC reactors (n = 8) accepted grafts for 25 to 260+ days, and nonimmunosuppressed low MLC reactors (n = 4) accepted grafts for 9-55 d. Rejection (hyperglycemia) of FDPS grafts was sudden, permanent, and unpredictable despite weekly intravenous glucose tolerance tests with measurements of glucose disappearance rates and serum insulin responses. Nevertheless, serial in vitro cell-mediated lymphocytotoxicity (CML) assays revealed increases in CML before graft rejection in low MLC reactors, and decreases in both CML and MLC responses before graft rejection in high MLC reactors. FDPS graft survival was indefinite (>6 mo) in group II dogs, despite low-grade MLC reactivity (2:4 dogs) and CML responses (4:4 dogs). Biopsies of FDPS grafts at 6 mo in normoglycemic dogs showed disappearance of exocrine tissue and coalescence of islets in both groups I and II, but with less fibrosis in group I (immunosuppressed). These results indicate that (a) pancreatic islets in vascularized grafts (FDPS) may survive indefinitely in the presence of a good tissue match best predicted by MLC testing, (b) tissue specific histocompatibility factors appear to be common enough between kidney and pancreas to allow for long-term survival of both organs transplanted from the same donor, at least in appropriate recipients (group II), and (c) immunosuppression is associated with less fibrosis in FDPS allografts.

Animals↗
PubMed1980

Appearance of cytoskeletal components on the surface of leukemia cells and of lymphocytes transformed by mitogens and Epstein-Barr virus.

Lactoperoxidase iodination and two-dimensional electrophoresis of the labeled proteins have demonstrated well-characterized cytoskeletal proteins (actin and tubulins) on the surface of human lymphocytes undergoing blastogenic transformation and of certain malignant human cells. Such proteins could not be detected on the surface of normal resting human lymphocytes. The most prominent cytoskeletal protein identified on the surface membrane of mitogen-transformed T and B lymphocytes was actin. In Epstein-Barr virus genome-positive Burkitt's lymphoma and lymphoblastoid cell lines and in two leukemia cells, the major iodinated membrane protein components were actin and alpha 1-, alpha 2-, and beta-tubulins. These proteins were firmly connected to the cytoplasmic skeleton and could not be removed by Triton X-100. Concurrent immunofluorescence studies with specific antibodies and F(ab')2 fragments confirmed the appearance of cytoskeletal components on the biochemical data, and indicated that such cytoskeletal proteins formed distinctive patterns on the cell surface, ranging from small patches to large projections. Five-hour labeling with [35S]methionine indicates that all such cells released large quantities of labeled actin and tubulins into the culture medium. These materials were not readsorbed to the membrane surfaces of the cells.

Actins↗
PubMed1979

Induction of unresponsiveness to major transplantable organs in adult mammals: a recapitulation of ontogeny by irradiation and bone marrow replacement.

Transplantation of renal allografts obtained from prospectively selected genotypically DLA-identical donors into supralethally irradiated dogs reconstituted with their own stored bone marrow has produced a state of unresponsiveness to these kidneys in the recipients. Eleven of 18 kidneys transplanted at 12 hours after marrow replacement currently survive with normal function and maintain life in the recipients for 757, 800, 825, 978, 1062, 1092, 1136, 1282, 1373, 1380, and 1381 days, respectively. Similar results occurred in eight of 13 allografts transplanted at 28 hours after marrow replacement, which currently survive for 349, 363, 377, 407,436,470, 485, and 513 days, respectively, and in eight of 13 kidneys grafted at 36 hours after marrow replacement, which are surviving for 197, 247, 298, 324, 337, 396, 443, and 472 days, respectively. Achievement of optimal results is dependent on the specific timing and sequence of each procedure. Only four of 16 recipients of kidneys transplanted at the time of marrow replacement were unresponsive to their allografts. Similarly, only five of 19 recipients of kidneys placed in irradiated dogs at 40 hours before marrow replacement accepted such allografts. When kidney transplants were placed into the recipients 20 hours before removal of marrow, irradiation, and reconstitution with stored marrow, only three of 21 dogs became unresponsive to such ailografts. In five of 12 instances, the recipients were also unresponsive to skin allografts obtained from their respective kidney donors. Such skin grafts currently survive for 606, 673, 687, 701, and 708 days, respectively. The remaining seven skin grafts were rejected at 28, 39,42, 84, 90, 92, and 115 days, respectively. Second- and third-set skin grafts from the same kidney donor were rejected by six of these dogs at 19, 20, 21, 29, 29, and 30 days, and at 21, 22, 23, 24, 27, and 27 days, respectively. Rejection of these skin grafts had no detectable effect on the function and survival of kidney allografts from the same source. Seven of eight skin grafts obtained from other DLA-identical donors were rejected at 13,14,16,25,28,38, and 84 days, respectively; one allograft continues to survive for 708 days. Eleven DLA-incompatible skin allografts placed on the recipients at the same time were rejected within 11-20 days. Supralethal total body irradiation and bone marrow replacement can establish in the adult canine host a privileged phase of immunological reactivity during which exposure to alloantigens produces specific long-term unresponsiveness rather than sensitization. The use of stored autologous rather than allogeneic bone marrow for reconstitution of the irradiated recipient eliminates the hazards of GVH complication usually associated with this procedure. This consideration and the apparent capacity of the tolerant host to maintain a long-term state of unresponsiveness without any further immunosuppressive therapy point to the potential relevance of the results to human transplantation.

Animals↗
PubMed1979

The major histocompatibility complex (HLA) as a genetic marker in human craniofacial anomalies.

Study of the incidence and segregation of the serologically detectable A and B products of the HLA complex in 140 family units in which one or more offspring was afflicted with a developmental craniofacial anomaly has uncovered no evidence of an association between HLA-A or B antigens or haplotypes and the malformations under study. Further analysis of HLA-D products in the same family units by the mixed leukocyte culture (MLC) technique has, however, uncovered a relatively high incidence of non-reactivity between the cells of one (or both) parent(s) and cells of some offspring in 41 of the 140 families included in this study. The parent couples involved in this finding were unrelated and generally did not share any HLA-SD haplotypes. When this finding was studied further by Primed LD Typing techniques, the results in six families suggested that such MLC non-reactivity is a consequence of the sharing of LD alleles by each pair of parents in these families. The known polymorphism of the HLA-D locus (or loci) and the low incidence of comparable findings in the normal population suggest that LD allele sharing in this particular population may be related to the selection of certain particular HLA-D products in families afflicted with developmental craniofacial anomalies. This result may be relevant to the possible existence in man of an analogue of the murine T/t complex which may occur in linkage with the HLA complex, in the same manner as the linkage disequilibrium which is been documented between the t complex and H-2 in chromosome 17 of the mouse.

Adult↗
PubMed1979

Role of Ia-like products of the main histocompatibility complex in conditioning skin allograft survival in man.

This report correlates the survival time of 93 intrafamilial skin allografts performed under conditions of main histocompatibility complex (HLA) haploidentity with donor-recipient compatibility for products of the HLA-A, -B, -C, and -DR, as well as C3 proactivator, Glyoxalase I, and P loci located on the human 6th chromosome. Incompatibilities for HLA-A and -B (and to a lesser extent for HLA-C) and(or) for HLA-DR products exerted a strong influence upon the fate of skin allografts. When HLA-A and -B were considered alone, the most compatible group of grafts had a mean survival time of 15.8 d, as compared with 11.3 d for the most incompatible transplants. HLA-DR compatibility alone was associated with a mean survival time of 15.3 d, whereas HLA-DR-incompatible grafts had a mean survival time of 11.5 d. Incompatibilities for C3 proactivator, Glyoxalase I, and P did not have a significant effect upon graft survival. There was no evidence of an association between donor-recipient incompatibility at HLA-A, -B, or -C or at HLA-DR; such incompatibilities occurred independently of each other, in spite of the state of linkage disequilibrium known to exist between HLA-B and -DR. Incompatibilities for HLA-A, -B, and for HLA-DR exerted a potent additive effect upon graft survival. Skin grafts bearing one, two, or three incompatibilities had a mean survival time of 16.2, 13.7, and 10.7 d, respectively (P <0.0005).The results point to the important role played by the Ia-like products of the HLA complex (HLA-DR) in conditioning skin allograft survival in man. This consideration may be of direct relevance to the potential clinical usefulness of in vitro serological techniques for the detection of donor-recipient compatibility for HLA-DR.

Female↗