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Biomedical subjects

R Storb

Publications and source records attributed to R Storb.

At least 451 records · Page 25Linked to original sources
PubMed1987

Monoclonal antibodies to canine differentiation antigens.

A limited panel of mAbs directed at canine cell populations is available. The number of antibodies is growing, permitting us to learn more about functional properties of the respective cell populations both in vitro and in vivo. Studies such as those dealing with facilitation of engraftment or positive selection of stem cells will be of great importance in clinical marrow transplantation. Consequently, further studies in this canine model are desirable.

Animals↗
PubMed1987

Engraftment of dogs with Ia-positive marrow cells isolated by avidin-biotin immunoadsorption.

Previous work has shown failure of engraftment in lethally irradiated dogs when autologous marrow was depleted of Ia-positive cells with an anti-Ia antibody and complement before infusion. In the current study, we have utilized an avidin-biotin immunoadsorption procedure to obtain a population of highly enriched Ia-positive cells for autologous bone marrow transplantation in dogs given lethal irradiation. Dog marrow cells (2.4 to 7.0 X 10(9) cells) that contained 8.6% to 19.9% Ia-positive cells were treated successively with monoclonal antibody 7.2, which reacts with a framework determinant of Ia-antigen, and biotin-conjugated goat antimouse immunoglobulin. These treated cells were passed over a column of avidin-Biogel (polyacrylamide) and the adherent cells removed by mechanical agitation. Seven lethally irradiated dogs were transplanted with 5.9 to 33.4 X 10(6) recovered adherent cells per kilogram of which 69.0% to 88.0% were Ia-positive. All dogs had hematologic recovery; six are alive and well with durable engraftment and one died on day 15 posttransplant. They are immunologically normal as determined by lymph node and bone marrow biopsies, lymphocyte function, and immunophenotyping of peripheral blood and bone marrow cells. These data provide further evidence that canine hematopoietic stem cells express Ia-like antigens and that these cells are capable of complete hematopoietic and immunologic reconstitution in an autologous model.

Animals↗
PubMed1987

Two monoclonal antibodies recognizing subpopulations of canine T lymphocytes with or without suppressor/cytotoxic functions.

Two monoclonal antibodies (mAb) were studied in regards to their ability to differentiate functionally distinct subsets of canine lymphocytes. MAb DT-2 (IgG2a) reacts with 33-55% of canine peripheral blood mononuclear cells (PBMC), which are also surface immunoglobulin (SIg) negative. Cytolytic treatment with DT-2 eliminates the ability of PBMC to respond to allogeneic cells and mitogens but does not affect alloantigen-primed cytotoxic or suppressor cells. MAb E11 (IgG3) reacts with 15-40% of PBMC which are also SIg negative. Cytolytic treatment with E11 affects responses of PBMC to allogeneic cells or mitogens to a lesser extent than DT-2 but eliminates cytotoxic and suppressor cells among alloantigen-primed lymphocytes. Thus, canine helper cells appear to be Thy 1+, 7.2+, DT-2+, DLy 6+, DLy 1+, E11-, SIg-, and cytotoxic/suppressor cells Thy 1+, 7.2+, E11+, DT-2+, DLy 6-, DLy 1-, SIg-.

Animals↗
PubMed1987

Gamma-interferon in aplastic anemia: inability to detect significant levels in sera or demonstrate hematopoietic suppressing activity.

A radioimmunoassay (RIA) was used to quantitate biologically active gamma interferon (INF-gamma) in sera and in supernatants of cultured mononuclear cells obtained from 50 patients with aplastic anemia. Only five of the 50 serum samples had INF-gamma levels above background (greater than 0 less than 0.5 units per mL). Detectable levels of spontaneous INF-gamma (0.3 to 868 U/mL) were found in 18 of the 50 mononuclear cell supernatants tested. The addition of patient sera or INF-gamma positive supernatants to cultures of normal hematopoietic colonies did not result in reduced colony growth. Flow cytofluorimetric analysis of mononuclear cells failed to establish a correlation between the presence of INF-gamma in supernatants and the number of activated T cells or natural killer (NK) cells in the mononuclear cell population. However, a significant correlation did exist between the presence of monocytes and the production of INF-gamma. Contrary to previous reports, our data suggest that patients with aplastic anemia do not have high circulating levels of INF-gamma. Unstimulated mononuclear cells from some patients will produce significant levels of INF-gamma, but this does not result in decreased in vitro hematopoiesis.

Anemia, Aplastic↗
PubMed1987

Induction of hepatic veno-occlusive disease in dogs.

The authors attempted to induce hepatic veno-occlusive disease (VOD) in 64 dogs. Preparative treatments included combinations of total-body irradiation (TBI) or localized hepatic irradiation (LI) or both and chemotherapy consisting of dimethylbusulfan (DMB), L-phenylalanine mustard (L-PAM), methotrexate, or monocrotaline. VOD occurred infrequently in those dogs given 9.2 Gy TBI and DMB (1/10), TBI and/or LI (9.2-27 Gy) with L-PAM (2/36) or high dose methotrexate and LI (0/2). Specifically, VOD occurred in the dogs with a shorter interval between TBI and DMB or in the dog that received the glutathione reductase inhibitor, buthionine sulfoximide (BSO) before L-PAM. In contrast, among 17 dogs given monocrotaline, 8 developed VOD, particularly when used with L-PAM +/- irradiation (7/13). The major cause of death, early gastrointestinal toxicity, was further augmented by higher doses of irradiation, by shortening the interval between LI and L-PAM administration to less than 4 weeks, and administering BSO or monocrotaline before L-PAM. Gastrointestinal toxicity was lessened by giving low dose cyclophosphamide given before L-PAM. VOD can be produced in dogs especially with monocrotaline or BSO given before and L-PAM +/- irradiation. However, gastrointestinal toxicity renders the study of VOD beyond the acute phase difficult. Nevertheless, this approach appears useful for the study of VOD in other animals and for developing agents aimed at preventing VOD.

Animals↗
PubMed1987

Second marrow transplants in patients with aplastic anemia rejecting the first graft: use of a conditioning regimen including cyclophosphamide and antithymocyte globulin.

Sixteen (11%) of 146 consecutive patients with severe aplastic anemia prepared for engraftment with cyclophosphamide (200 mg/kg) rejected marrow grafts from their HLA-identical siblings. They were given a second marrow transplant from either the same (n = 13) or a second (n = 3) HLA-identical sibling between 23 and 743 (median 86) days after the first transplant. The preparation for the second transplant included cyclophosphamide, 50 mg/kg, on each of four successive days. Twelve hours after each of the first three doses of cyclophosphamide, antithymocyte globulin, 30 mg/kg/dose, was infused. One of the 16 patients died from infection too early after the second transplant to be evaluated, two had failure of engraftment and died with infection, one rejected the second graft and is surviving almost 5 years later with full autologous marrow recovery, and 12 had successful and sustained second grafts. Of these 12, six are surviving between 11 months and 7 3/4 years. Four of the six have no graft-v-host disease (GVHD), while two have chronic GVHD requiring treatment. Five have Karnofsky scores of 100% and one of 90%. Six of the 12 patients with sustained grafts died between 63 days and 38 months after transplantation, four with infections (related in two patients to chronic GVHD), one with acute GVHD, and one with hemorrhage. The average interval from first to second transplant was 308 days during the past five years, compared to 61 days in earlier patients. Five of seven recent patients are surviving, compared to two of nine earlier patients. In conclusion, successful second transplants after cyclophosphamide and antithymocyte globulin are possible in most patients with aplastic anemia who have rejected their first marrow grafts; however, mortality remains high, with only 40% of the patients becoming long-term survivors.

Adolescent↗
PubMed1987

Graft-versus-leukemia in man: relationship of acute and chronic graft-versus-host disease to relapse of acute leukemia following allogeneic bone marrow transplantation.

To study the effect of acute and chronic graft-versus-host disease (GVHD) on recurrent leukemia, we analysed data on patients with acute leukemia receiving allogeneic marrow transplants in Seattle between 1970 and 1986. Four hundred fifty-four patients survived in remission 150 days after HLA-identical transplant and 114 currently survive five to fifteen years after marrow grafting. At the time of transplant, 252 patients had acute nonlymphocytic leukemia in remission or relapse and 202 had acute lymphocytic leukemia in remission or relapse. According to Kaplan-Meier estimates, recurrence of leukemia following transplantation was observed in 28% of patients developing moderate to severe (grade II-IV) acute GVHD and 48% of patients with no or mild (grade O-I) acute GVHD (p = 0.0028). Relapse was observed in 34% of patients developing clinical extensive chronic GVHD and 45% of patients free of chronic GVHD (p = 0.0001). The incidence of recurrent leukemia was 28% in recipients developing both acute and chronic GVHD and 52% in patients free of both acute and chronic GVHD (p = 0.0001). These data confirm an apparent graft-versus-leukemia effect in patients developing GVHD after allogeneic marrow grafting. Current studies are aimed at determining the influence of such apparent adoptive immunotherapy within the different categories of leukemia and methods to manipulate and augment the clinical benefit of this observation.

Acute Disease↗
PubMed1987

Graft versus leukemia effect in man: the relapse rate of acute leukemia is lower after allogeneic than after syngeneic marrow transplantation.

To determine whether allogeneic bone marrow transplantation (BMT) is associated with a graft vs leukemia (GVL) effect in man, the relapse rate of acute leukemia after allogeneic BMT was compared with that occurring after syngeneic (genetically identical twin) BMT. The patients had ALL or ANL in second or subsequent complete remission (CR) or in relapse. The allogeneic and syngeneic marrow recipients were comparable in diagnosis, age, and interval from diagnosis to BMT and received comparable chemoradiotherapy regimens. Allogeneic marrow recipients, however, received, in addition, GVH disease prophylaxis, most often methotrexate and, more recently, cyclosporine or both. All patients treated by the Seattle team from 1970-1986 are included. Leukemic recurrence was observed in 62% of 785 allogeneic recipients and 75% of 53 syngeneic recipients (p less than 0.0001). The results confirm the circumstantial evidence for a GVL effect exerted by allogeneic marrow. Analyses are in progress to determine whether a GVL effect exists in subsets of patients as a function of their particular diagnosis or status at the time of BMT.

Bone Marrow Transplantation↗
PubMed1987

Pathology of the thymus after allogeneic bone marrow transplantation in man. A histologic immunohistochemical study of 36 patients.

A major hypothesis to explain the immunodeficiency associated with bone marrow transplantation states that thymic epithelial damage due to graft-versus-host disease (GVHD) abrogates or delays the recovery of normal immunologic function. This study evaluated the thymus glands of 36 human bone marrow transplant recipients dying between 4 and 1742 days after transplant using histology, histochemistry, and immunohistology. The observations lead to a model of thymic damage by irradiation, chemotherapy, and GVHD in which early injury by all three of these agents results in profound thymic atrophy followed by long-delayed restitution. Patients undergoing total body irradiation showed more severe damage to thymic cortical and medullary epithelium than did patients undergoing chemotherapy alone as preparation for transplantation. Patients with GVHD showed additional damage in the form of individual thymic epithelial cell death and showed HLA-DR surface protein expression on thymic epithelium during GVHD. Longer-term survivors showed a profoundly delayed restitution of normal thymic epithelium and delayed evidence of restored lymphopoiesis. A few patients dying late after transplant showed evidence of reconstitution of normal thymic structure or nodules of lymphopoiesis in focal areas of epithelial-cell reconstitution. Evidence of such lymphopoiesis was seen at times ranging between 90 and 1742 days after grafting. The data are consistent with a model of long-standing thymic damage caused by GVHD which is reversible after the development of tolerance.

Adolescent↗
PubMed1987

Clonal cytogenetic abnormalities in patients with otherwise typical aplastic anemia.

Between June 1981 and August 1986, 183 patients with the referring diagnosis of aplastic anemia were evaluated with cytogenetic studies and marrow biopsies. Seven patients (4%) on biopsy were found to have myelodysplasia. Seven of the 176 patients (4%) with marrow biopsies that confirmed the pathologic diagnosis of severe aplastic anemia were found to have clonal cytogenetic abnormalities in unstimulated marrow samples. Among the 169 patients with typical aplastic anemia and no cytogenetic abnormalities, 5 (3%) subsequently developed either myelodysplasia or leukemia. Two of three patients with pathologically confirmed aplastic anemia and clonal cytogenetic abnormalities, who were not transplanted, developed myelodysplasia. These results demonstrate that approximately 4% of patients with aplastic anemia have clonal cytogenetic abnormalities of marrow cells, and that while all patients with aplastic anemia may have some risk of developing leukemia, those with a cytogenetic abnormality have an especially high risk.

Adolescent↗
PubMed1987

Allogeneic and syngeneic marrow transplantation following high dose dimethylbusulfan, cyclophosphamide and total body irradiation.

Fifty-eight patients received an allogeneic or syngeneic marrow transplant following conditioning with high doses of dimethylbusulfan (DMB), cyclophosphamide (CY) and total body irradiation (TBI). Thirty-two patients had either chronic myeloid leukemia (CML) in accelerated phase or blast transformation, or acute leukemia after first relapse. The actuarial survival of these 32 patients at 3 years was 12% compared with 25% for a group of 206 patients with similar diagnoses prepared for transplantation with CY and TBI alone. This reduced survival was associated with a greater incidence of early non-leukemic deaths, in particular as a result of severe hepatic veno-occlusive disease. The incidence of leukemic relapse was not different in the two groups. Of 13 patients with CML in chronic phase who received syngeneic transplants following DMB, CY and TBI, nine are alive in hematologic and cytogenetic remission from 3.9 to 9.4 (median 6.2) years post-transplant.

Adolescent↗
PubMed1987

Treatment of marrow graft recipients with thymopentin.

Four adult patients with acute non-lymphocytic leukemia were given marrow grafts from HLA-identical siblings following 120 mg/kg cyclophosphamide and 10-12 Gy total body irradiation. All received intermittent intravenous methotrexate as prophylaxis against graft-versus-disease (GVHD). In an attempt to accelerate immune recovery and prevent GVHD, each patient received thymopentin (TP5) for 100 days after grafting. No adverse effects were seen with TP5 administration. All four patients developed acute GVHD (one grade I, one grade II, and two grade III). Two patients died of late infections: one at 6 months from Pneumocystis carinii pneumonia and one at 11 months from disseminate Pseudomonas, Candida and cytomegalovirus infection. Two patients survive more than 3.9 years after transplantation with Karnofsky scores of 100%. One required treatment for chronic GVHD and recovered. Delayed-type hypersensitivity, antibody production to specific antigen in vivo, and results of in vitro immunologic studies were not altered by TP5 treatment. We conclude that while the administration of TP5 in these patients as described was not harmful, it did not prevent opportunistic infection, improve immunologic reconstitution or lower the incidences of acute or chronic GVHD from that of our previous experiences without thymopentin.

Adult↗
PubMed1987

Study of a human minor alloantigen in relation to clinical graft-versus-host disease.

Sixty-seven pairs of HLA matched siblings, each comprising marrow donor and recipient in the Seattle marrow transplant program, were analyzed to establish phenotype for a newly described minor H antigen, W1. The test for phenotype entailed cold target inhibition of cytotoxicity, directed at this antigen and mediated by specifically stimulated T cell lines. There were 58 compatible and six W1 incompatible pairs. The low frequency of W1 mismatch is due to the strong preponderance of W1-positive individuals in the general population. Severe graft-versus-host disease (GVHD), both acute and chronic, was observed among the 58 recipients of marrow from W1 matched donors. These results do not reveal any particular importance for W1 incompatibility in human GVHD and indeed indicate that other systems are involved. Even if some cases are triggered by incompatibility at W1, the maximum frequency with which this could occur would be about 10%, due to the limited polymorphism of this alloantigenic system.

Acute Disease↗