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Biomedical subjects

H J Deeg

Publications and source records attributed to H J Deeg.

At least 127 records · Page 7Linked to original sources
PubMed1995

DLA-identical bone marrow grafts after low-dose total body irradiation: effects of high-dose corticosteroids and cyclosporine on engraftment.

Previous studies found that marrow allografts from DLA-identical littermates resulted in survival of 60% of recipient dogs after an otherwise lethal dose of 450 cGy of total body irradiation (TBI), either because of successful allografts or autologous recovery after rejection of the allografts. Forty percent of dogs died with marrow aplasia after allograft rejection. The current study asked whether allogeneic engraftment could be enhanced and survival improved by treating allograft recipients with high doses of corticosteroids or with cyclosporine (CSP), administered either before or after transplantation. Five dogs in group 1 received corticosteroids beginning on day -5 and ending on day 32 after transplant. The starting dose was 12.5 mg of prednisone per kilogram orally twice daily. All five dogs rejected their allografts; three died early with marrow aplasia and two showed endogenous marrow recovery. Nine dogs received CSP from day -6 to day -1 before transplantation at a dose of 20 mg/kg/d intravenously administered in divided doses. All nine dogs rejected the marrow allograft; six died with marrow aplasia and three survived with endogenous marrow recovery. Seven dogs received CSP after transplantation at a dose of 30 mg/kg/d orally from day -1 to day 35. All seven had sustained allografts (two mixed chimeras and five complete donor-type chimeras) and became healthy long-term survivors without graft-versus-host disease. These results extend previous observations and confirm that grafts of marrow from DLA-identical littermates improved survival of dogs exposed to low but otherwise lethal doses of TBI. Additional therapy with high-dose corticosteroids administered peritransplantation and posttransplantation or CSP administered before transplantation neither enhanced the rate of allogeneic engraftment nor improved survival; however, CSP administered after transplantation resulted in successful allografts and event-free survival in all cases.

Adrenal Cortex Hormones↗
PubMed1995

Major histocompatibility complex class II-mediated inhibition of hematopoiesis in long-term marrow cultures involves apoptosis and is prevented by c-kit ligand.

Expression of major histocompatibility complex (MHC) class II molecules is developmentally regulated and lineage dependent. Their role in hematopoiesis is not well defined. Previous studies in a canine model showed that dogs given 920 cGy of total body irradiation, transplanted with autologous marrow, and treated with anti-MHC class II monoclonal antibody (MoAb) immediately posttransplant experienced only a transient granulocyte recovery that was followed by graft failure. In the present study, the effect of anti-MHC class II MoAbs on canine in vitro hematopoiesis was investigated. Anti-MHC class II MoAb H81.9 or B1F6 (both recognizing nonpolymorphic determinants) had no inhibitory effect when added directly to colony-forming unit-granulocyte-macrophage (CFU-GM) grown in agar. However, the addition of intact MoAb or as F(ab')2 fragments to long-term marrow cultures (LTMCs) resulted in a dose-dependent inhibition of the generation of CFU-GM among nonadherent cells. Inhibition was most profound with MoAb added at the time of initiation of culture. However, even if MoAb was added 3 weeks after recharging LTMCs, CFU-GM generation rapidly decreased. In addition, the number of adherent cells in LTMCs decreased; predominantly fibroblast-like cells with prominent cytoplasmic vesiculation remained. Acridine orange/ethidium bromide staining and TdT-mediated deoxyuridine triphosphate-digoxigenin nick end labeling (TUNEL) tests showed an increase in the proportion of apoptotic cells in both the nonadherent and adherent compartments. Binding of anti-MHC class II MoAb to unfractionated marrow cells resulted in an increase in free (Ca2+)i; no changes in tyrosine phosphorylation pattern were observed. The addition of stem cell factor (SCF), but not granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor, to LTMCs prevented apoptosis, and the generation of CFU-GM was indistinguishable from controls. Similarly, a supportive adherent layer was maintained. Thus, anti-MHC class II MoAbs interfere with hematopoiesis both in vitro and in vivo. The mechanism involves programmed cell death in subpopulations of adherent and nonadherent cells. Inhibition of hematopoiesis is abrogated by exogenous SCF.

Animals↗
PubMed1995

Thrombocytopenia in dogs induced by granulocyte-macrophage colony-stimulating factor: increased destruction of circulating platelets.

Administration of recombinant canine granulocyte-macrophage colony-stimulating factor (rcGM-CSF) to normal dogs in previous studies induced an increase in peripheral blood neutrophils and a dose-dependent decrease in platelet counts. In six dogs that received the highest tested dose of rcGM-CSF (50 micrograms/kg/d) for a minimum of 12 days, the mean nadir of the platelet count was 46,000/microL (range, 4,000 to 91,000/microL) on day 9 +/- 1.1 after starting therapy, compared with a mean baseline platelet count of 398,000/microL (range, 240,000 to 555,000/microL). In three dogs, survival of autologous 111In-labeled platelets was reduced from a mean of 4.9 days to 1.3 days during the administration of rcGM-CSF. Biodistribution studies with gamma camera imaging indicated that there was an increase in mean hepatic uptake during the administration of rcGM-CSF, from 15% to 44% of the total injected 111In-labeled platelets at 2 hours, whereas splenic uptake was not significantly changed. In contrast, in two evaluable dogs who were recipients of 111In-labeled platelets from matched allogeneic donors receiving rcGM-CSF, platelet survival was not reduced and no increased hepatic uptake was noted. A third dog became alloimmunized to the matched donor platelets and was not evaluable. Immunohistologic studies of liver and spleen were performed with monoclonal antibodies specific for canine gpIIb/IIIa and P-selectin in dogs treated with rcGM-CSF and compared with untreated controls. On treatment, a marked reduction of platelets in the red pulp of the spleen was evident, and in general, the presence of platelet antigen in the liver was unchanged. Therefore, platelets were not being sequestered, but destroyed in the liver and spleen. The platelet antigens, P-selectin and gpIIb/IIIa, were identified in association with Kupffer cells in the liver, but no difference in the number of distribution of these Kupffer cells was found between controls and rcGM-CSF-treated dogs. In the spleen during rcGM-CSF treatment, most platelet antigens were associated with large mononuclear cells in the marginal zone. During administration of rcGM-CSF, CD1c and CD11c expression was increased on Kupffer cells. Platelet P-selectin expression and binding of leukocytes to circulating platelets were unchanged from baseline studies with rcGM-CSF treatment. In conclusion, during the administration of rcGM-CSF to dogs, a local process in the liver and spleen is induced resulting in thrombocytopenia.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Allogeneic marrow transplantation following cyclophosphamide and escalating doses of hyperfractionated total body irradiation in patients with advanced lymphoid malignancies: a Phase I/II trial.

PURPOSE: To define the maximum tolerated dose (MTD) of unshielded total body irradiation (TBI) delivered from dual 60C sources at an exposure rate of 0.08 Gy/min and given in thrice daily fractions of 1.2 Gy in patients with advanced lymphoid malignancies. METHODS AND MATERIALS: Forty-four patients with a median age of 28 (range 6-48) years were entered into a Phase I/II study. All patients received cyclophosphamide (CY), 120 mg/kg administered over 2 days before TBI. Marrow from human leukocyte antigen (HLA) identical siblings was infused following the last dose of TBI. An escalation-deescalation schema designed to not exceed an incidence of 25% of Grade 3-4 regimen-related toxicities (RRTs) was used. The first dose level tested was 13.2 Gy followed by 14.4 Gy. RESULTS: None of the four patients at the dose level of 13.2 Gy developed Grade 3-4 RRT. Two of the first eight patients receiving 14.4 Gy developed Grade 3-4 RRT, establishing this as the MTD. An additional 32 patients were evaluated at the 14.4 Gy level to confirm these initial observations. Of 40 patients receiving 14.4 Gy, 13 (32.5%) developed Grade 3-4 RRTs; 46% in adults and 12% in children. The primary dose limiting toxicity was Grade 3-4 hepatic toxicity, which occurred in 12.5% of patients. Noninfectious Grade 3-4 interstitial pneumonia syndrome occurred in 5% of patients. The actuarial probabilities of event-free survival, relapse, and nonrelapse mortality at 2 years were 0.10, 0.81, and 0.47, respectively, for patients who received 14.4 Gy of TBI. CONCLUSIONS: The outcome for patients receiving 14.4 Gy of TBI was not different from previous studies of other CY and TBI regimens in patients with advanced lymphoid malignancies. These data showed that the incidence of Grade 3-4 RRTs in adults was greater than the 25% maximum set as the goal of this study, suggesting that 13.2 Gy is a more appropriate dose of TBI for adults, while 14.4 Gy is an appropriate dose for children.

Adolescent↗
PubMed1995

A toxicity study of trimetrexate used in combination with cyclosporine as acute graft-versus-host disease prophylaxis in HLA-mismatched, related donor bone marrow transplants.

This study evaluated the acute toxicity of trimetrexate (TMTX) used in combination with cyclosporine (CsA) for prevention of acute graft-versus-host disease (GVHD) in patients undergoing allogeneic marrow transplantation from HLA-mismatched, related donors. TMTX has a mechanism of action similar to that of methotrexate (MTX); however, unlike MTX, TMTX is not primarily dependent on renal excretion. Patients were conditioned for transplant with cyclophosphamide, anti-thymocyte globulin, and total body irradiation. TMTX, 10 mg/m2 i.v., was administered on days 1, 3, 6, 11, 18, 25, 32, and 39 after transplant. CsA, 1.5 mg/kg i.v., was administered every 12 hr beginning on day-1. Eleven patients with hematologic malignancies or aplastic anemia (median age = 34 yr) received TMTX. Toxicity assessed included nausea, vomiting, fever, rash, time to myeloid and platelet engraftment, mucositis, and hepatic and renal dysfunction. Toxicity of TMTX was not different from that observed with MTX in a similar patient population. One patient died on day 16 before engraftment. The other 10 patients all engrafted and all developed acute GVHD at a median time of 11 days after transplant. The major manifestation of acute GVHD was in the skin, and all but one patient responded to primary therapy with corticosteroids. Seven patients have survived a median of 447 days after transplant. No significant toxicity from TMTX was observed. Further trials are warranted to define the role of TMTX in marrow transplantation.

Adolescent↗
PubMed1995

Cataracts after bone marrow transplantation: long-term follow-up of adults treated with fractionated total body irradiation.

PURPOSE: To determine the risk of, and risk factors for, developing cataracts after bone marrow transplantation. METHODS AND MATERIALS: Four hundred and ninety-two adults who underwent bone marrow transplantation in Seattle were followed for 2 to 18 (median, 6) years. Before transplantation, patients received a preparative regimen of chemotherapy plus total body irradiation (TBI) (n = 407) or chemotherapy alone, without TBI (n = 85). TBI was administered in a single dose of 10 Gy (n = 74) or in fractionated doses totaling 12-15.75 Gy (n = 333). The risk of cataracts was determined for groups of patients with respect to the type of preparative regimen received and other pretransplant and posttransplant variables. RESULTS: One hundred and fifty-nine patients (32%) developed cataracts between 0.5 to 11 (median, 2.3) years after transplantation. The probability of cataracts at 11 years after transplantation was 85%, 50%, 34%, and 19% for patients receiving 10 Gy of single-dose TBI, > 12 Gy fractionated TBI, 12 Gy fractionated TBI, and no TBI, respectively (p < 0.0001). Among those developing cataracts, the severity was greater in patients after single-dose TBI (59% probability of surgical extraction) than after > 12 Gy fractionated TBI, 12 Gy fractionated TBI, or no TBI (33%, 22% and 23%, respectively). Patients given corticosteroids after transplant had a higher probability of cataracts (45%) than those without steroids (38%) (p < 0.0001). In a proportional hazards regression model, the variables that were correlated with an increased probability of cataracts were single-dose TBI (relative risk (RR) = 2.46) and steroid therapy (RR = 2.34), while a decreased probability of cataracts was correlated with a nonTBI preparative regimen (RR = 0.41). The yearly hazard of developing cataracts in recipients of single-dose TBI was highest during the third year after transplantation, while in recipients of fractionated TBI, the hazard was distributed among years one through seven. The probability of cataracts in all groups reached a plateau at 7 years after transplantation, after which the development of cataracts was extremely unlikely. CONCLUSION: TBI is the major risk factor for developing cataracts after BMT. Single-dose TBI results in the highest risk of cataracts. However, the risk of cataracts in recipients of fractionated-TBI is significantly higher than in patients who receive no TBI. In addition to TBI, steroid therapy is an independent risk factor for cataracts after BMT.

Adolescent↗
PubMed1995

Use of a water-soluble busulfan formulation--pharmacokinetic studies in a canine model.

In a canine model we investigated the toxicity and pharmacokinetics of a water soluble busulfan preparation. Busulfan was dissolved in dimethylsulfoxide (DMSO) and administered either orally or intravenously in a single dose of 1 mg/kg. The application in either preparation was well tolerated. In seven dogs, peak levels in the range of 730 ng/mL to 1,000 ng/mL were measured after intravenous injection with an area under curve (AUC) of 75 ng.h/kg.mL to 146 ng.h/kg.mL. It was of note that even the oral administration of the same busulfan preparation resulted in AUC values in the same range as observed after parenteral application. The absorption rate of busulfan tablets in our model was as unpredictable as documented in clinical trials. On the basis of the present study, clinical trials using busulfan dissolved in DMSO given either intravenously or orally appear warranted. This approach should lead to predictable blood levels, reduced toxicity, and increased efficacy of busulfan-containing regimens.

Administration, Oral↗
PubMed1995

Contact- and growth factor-dependent survival in a canine marrow-derived stromal cell line.

Cell-cell interactions and the presence of growth factors such as stem cell factor (SCF; or c-kit ligand) or interleukin-6 (IL-6) are involved in the proliferation and differentiation of the canine marrow-derived stromal cell line DO64. In the presence of SCF, stromal cells are induced to differentiate, but not to proliferate. In contrast, in the presence of IL-6, stromal cells are induced to proliferate rather than to differentiate in culture. Both SCF and IL-6 are produced by the stromal cells themselves and, thus, act as autocrine factors. In addition, DO64 cells also interact physically with each other in culture when grown under optimal culture conditions (70% to 90% cell confluence and in the presence of serum), thereby supporting proliferation and maintaining viability. Under conditions of lower cell density or low serum or growth factor concentrations in culture, DO64 cells tend to aggregate and form clusters. This increase in local cell concentration is associated with preservation of viability, presumably because of the accumulation of autocrine factors. If no signal, neither intercellular nor soluble, is provided, and DO64 cells are not able to reach a critical cell density or to produce sufficient factors in an autocrine fashion, the cells cease to proliferate and eventually die.

Animals↗
PubMed1995

Hematopoietic stem cell compartment: acute and late effects of radiation therapy and chemotherapy.

The bone marrow is an important dose-limiting cell renewal tissue for chemotherapy, wide-field irradiation, and autologous bone marrow transplantation. Over the past 5-10 years a great deal has been discovered about the hematopoietic stem cell compartment. Although the toxicity associated with prolonged myelosuppression continues to limit the wider use of chemotherapy and irradiation, ways are being discovered to circumvent this toxicity such as with the increasing use of cytokines. This review describes what is known of how chemotherapy and irradiation damage stem cells and the microenvironment, how cytokines protect hematopoietic cells from radiation damage and speed marrow recovery after chemotherapy or marrow transplantation, and how various types of blood marrow cells contribute to engraftment and long-term hematopoiesis after high doses of cytotoxic agents and/or total body irradiation.

Animals↗
PubMed1995

Differentiation of canine bone marrow cells with hemopoietic characteristics from an adherent stromal cell precursor.

Stromal cell lines were established from canine long-term marrow cultures, cloned by limiting dilution, and maintained in stromal cell-conditioned medium. These cells grew adherent, maintained stable growth rate and morphology under standard conditions (in 20-30% conditioned medium; confluency, 70-90%), and supported hemopoiesis in long-term marrow cultures. In the presence of exogenous recombinant canine stem cell factor (rcSCF), round cells developed from the adherent layer, detached, and remained in culture as viable floating cells. Round floating cells also appeared when cultures were grown to > 90% confluency without rcSCF. Round cells were smaller than adherent cells, expressed CD34, showed basophilic plasma, and stained positive for c-kit, MHC-class II markers, and myeloid markers. In standard assays for colony formation, the detached cells produced granulocyte-macrophage colony-forming units (CFU-GM), fibroblast colony-forming units (CFU-F), and less well-defined colony-forming units. In addition, on allogeneic feeder cells in long-term cultures, these cells generated hemopoietic colonies. Strikingly, the differentiation was reversible: when nonadherent cells were resuspended at lower density in serum-containing medium, they reattached and grew to confluence when, once again, round cells detached. Detached cells from this secondary cycle produced mainly CFU-F and few CFU-GM when placed in clonal assays. These results suggest that some fibroblast-like stromal cells have the potential to differentiate into cells with hemopoietic characteristics. These observations provide evidence for the existence of a quiescent precursor of hemopoietic progenitors in the bone marrow stroma of the adult dog.

Animals↗
PubMed1995

Stem cell factor-induced expression of p27kip-1 during hematopoietic differentiation.

The canine marrow stroma-derived CD34- DR- cell line D064 is able to differentiate into cells with characteristics of hematopoietic progenitors. While differentiating, these cells start to express CD34 and DR. Differentiation is induced by stem cell factor (SCF), while interleukin-6 (IL-6) inhibits differentiation, but promotes proliferation. The influence of SCF and IL-6 on differentiation and proliferation is reflected in the expression of p27kip-1. SCF induces a transient expression of p27kip-1, while no p27kip-1 is detectable in the presence of IL-6 or an anti-SCF monoclonal antibody. The accumulation of intracellular p27kip-1 precedes the differentiation of D064 cells. As these cells start to proliferate and more committed progenitors emerge, p27kip-1 is no longer expressed.

Animals↗
PubMed1995

Cyclosporine-induced apoptosis in CD4+ T lymphocytes and computer-simulated analysis: modeling a treatment scenario for HIV infection.

Cyclosporine A (CsA) is a potent immunosuppressive drug which interferes in vitro and in vivo with T-cell function. CsA has been shown to arrest T-cell maturation intrathymically and to inhibit T-cell proliferation. In this study, we demonstrate that CsA induces apoptosis in the canine CD4+ CD8- T-lymphocyte cell line 401 in a dose- and time-dependent fashion. Similar results could also be obtained from human peripheral blood lymphocytes. Apoptosis is observed within 4 hours after CsA application and is not prevented by excessive addition of ConA supernatant as a source of interleukins. The induction of apoptosis in CD4+ T lymphocytes suggests a possible treatment option for human immunodeficiency virus (HIV) infections, since the major target population for the HIV would be ablated at short term. A computer-simulated analysis with the "Cybermouse" HIV model confirmed that the virus would eventually disappear and HIV-infected macrophages would also be substantially reduced if CsA were given in combination with drugs which block viral replication (3'-azido 3'-deoxythymidine or 2',3'-dideoxycytidine). This treatment scenario could be applied under controlled conditions and with supportive patient care. A further review of the literature also suggests the positive impact of CsA treatment on the progression and outcome of AIDS-related mortality.

Animals↗
PubMed1995

Abnormalities of pulmonary function tests after marrow transplantation predict nonrelapse mortality.

To determine whether pulmonary function test (PFT) results after marrow transplantation were predictive of nonrelapse mortality, a review was made of prospective, nonrandomized PFT results for association with nonrelapse mortality by log-rank test and Cox proportional hazards modeling. The setting was a tertiary referral center. The patients were all marrow recipients who performed PFT between Days 60 and 120 after marrow transplantation between July 1, 1983 and December 31, 1990 (n = 906). At 3 mo after transplantation, the mean values for total lung capacity (TLC) and diffusing capacity decreased, and restrictive ventilatory defects (TLC < 80% of predicted) were noted in 34% of the cohort. Airflow rates (FEV1/FVC) were unchanged. A restrictive lung defect at 3 mo after transplant or a significant decline (> or = 15%) in TLC from baseline despite remaining within the normal range was associated with a twofold increased risk of nonrelapse mortality. Neither airflow obstruction nor impairment in diffusing capacity was associated with an increased risk. Abnormalities of the TLC at 3 mo after transplant were associated with death with respiratory failure, but not with an increased risk of chronic graft-versus-host disease (GVHD). There is an increase in the nonrelapse mortality rate associated with either the presence of a restrictive defect 3 mo after marrow transplantation or a significant decline in lung volume compared with baseline. This effect is most pronounced more than 1 yr after marrow transplant and appears to be a result of an increase in the rate of death with respiratory failure, not chronic GVHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Ultrastructural localization of stem cell factor in canine marrow-derived stromal cells.

Stromal cell lines derived from canine long-term bone marrow cultures (LTBMC) were characterized regarding the expression of growth factors and especially the localization of stem cell factor (SCF) (c-kit ligand). One cell line (DO64) was immortalized by transformation with a retroviral vector containing the open reading frames (ORFs) E6 and E7 of the human papilloma virus type 16 (HPV-16). Transfection did not change cellular characteristics but rendered the cell line more independent from culture conditions. The transformed line DO64 consisted mainly of fibroblast-like cells. In addition, some cells showed endothelial and some smooth-muscle cell features. Stromal cells expressed a broad spectrum of surface markers, including low levels of major histocompatibility-complex (MHC) class-II antigens. A new murine monoclonal antibody (MAb), RG7.6 (IgG1), specific for canine SCF, recognized the majority of fibroblast-like stromal cells. The staining pattern for SCF showed perinuclear and intracytoplasmic dense areas. Immunoelectron microscopy revealed the localization of SCF in secretory vesicles, the perivesicular cytoplasm, and bound to the cytoplasmatic membrane. RNA analysis showed that stromal cells transcribed, in addition to SCF, messages for granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte CSF (GM-CSF), interleukin-6 (IL-6), and transforming growth factor-beta (TGF-beta). In summary, we have established and characterized canine marrow-derived stromal cell lines, and using the new MAb RG7.6, we have localized SCF to cytoplasmatic vesicles as well as the membrane of stromal cells.

Animals↗