Natural history of papillary lesions of the urinary bladder in schistosomiasis. (1/9074)

Variable epithelial hyperplasia was observed in urinary bladder of nine capuchin monkeys (Cebus apella) when examined at cystotomy 94 to 164 weeks after infection with Schistosoma haematobium. These hosts were followed for 24 to 136 weeks postcystotomy to determine the status of bladder lesions in relation to duration of infection and to ascertain whether lesion samples removed at cystotomy reestablished themselves in autologous and heterologous transfers. There was involution of urothelial hyperplasia in eight of nine animals and no evidence for establishment of transplanted bladder lesions.  (+info)

Donor MHC and adhesion molecules in transplant arteriosclerosis. (2/9074)

Transplant-associated arteriosclerosis remains an obstacle to long-term graft survival. To determine the contribution to transplant arteriosclerosis of MHC and adhesion molecules from cells of the donor vasculature, we allografted carotid artery loops from six mutant mouse strains into immunocompetent CBA/CaJ recipients. The donor mice were deficient in either MHC I molecules or MHC II molecules, both MHC I and MHC II molecules, the adhesion molecule P-selectin, intercellular adhesion molecule (ICAM)-1, or both P-selectin and ICAM-1. Donor arteries in which ICAM-1, MHC II, or both MHC I and MHC II were absent showed reductions in neointima formation of 52%, 33%, and 38%, respectively, due primarily to a reduction in smooth muscle cell (SMC) accumulation. In P-selectin-deficient donor arteries, neointima formation did not differ from that in controls. In donor arteries lacking both P-selectin and ICAM-1, the size of the neointima was similar to that in those lacking ICAM-1 alone. In contrast, neointima formation increased by 52% in MHC I-deficient donor arteries. The number of CD4-positive T cells increased by 2.8-fold in MHC I-deficient arteries, and that of alpha-actin-positive SMCs by twofold. These observations indicate that ICAM-1 and MHC II molecules expressed in the donor vessel wall may promote transplant-associated arteriosclerosis. MHC I molecules expressed in the donor may have a protective effect.  (+info)

Organ-selective homing defines engraftment kinetics of murine hematopoietic stem cells and is compromised by Ex vivo expansion. (3/9074)

Hematopoietic reconstitution of ablated recipients requires that intravenously (IV) transplanted stem and progenitor cells "home" to organs that support their proliferation and differentiation. To examine the possible relationship between homing properties and subsequent engraftment potential, murine bone marrow (BM) cells were labeled with fluorescent PKH26 dye and injected into lethally irradiated hosts. PKH26(+) cells homing to marrow or spleen were then isolated by fluorescence-activated cell sorting and assayed for in vitro colony-forming cells (CFCs). Progenitors accumulated rapidly in the spleen, but declined to only 6% of input numbers after 24 hours. Although egress from this organ was accompanied by a simultaneous accumulation of CFCs in the BM (plateauing at 6% to 8% of input after 3 hours), spleen cells remained enriched in donor CFCs compared with marrow during this time. To determine whether this differential homing of clonogenic cells to the marrow and spleen influenced their contribution to short-term or long-term hematopoiesis in vivo, PKH26(+) cells were sorted from each organ 3 hours after transplantation and injected into lethally irradiated Ly-5 congenic mice. Cells that had homed initially to the spleen regenerated circulating leukocytes (20% of normal counts) approximately 2 weeks faster than cells that had homed to the marrow, or PKH26-labeled cells that had not been selected by a prior homing step. Both primary (17 weeks) and secondary (10 weeks) recipients of "spleen-homed" cells also contained approximately 50% higher numbers of CFCs per femur than recipients of "BM-homed" cells. To examine whether progenitor homing was altered upon ex vivo expansion, highly enriched Sca-1(+)c-kit+Lin- cells were cultured for 9 days in serum-free medium containing interleukin (IL)-6, IL-11, granulocyte colony-stimulating factor, stem cell factor, flk-2/flt3 ligand, and thrombopoietin. Expanded cells were then stained with PKH26 and assayed as above. Strikingly, CFCs generated in vitro exhibited a 10-fold reduction in homing capacity compared with fresh progenitors. These studies demonstrate that clonogenic cells with differential homing properties contribute variably to early and late hematopoiesis in vivo. The dramatic decline in the homing capacity of progenitors generated in vitro underscores critical qualitative changes that may compromise their biologic function and potential clinical utility, despite their efficient numerical expansion.  (+info)

Soluble HLA class I, HLA class II, and Fas ligand in blood components: a possible key to explain the immunomodulatory effects of allogeneic blood transfusions. (4/9074)

The immunomodulatory effect of allogeneic blood transfusions (ABT) has been known for many years. However, a complete understanding of the effects of ABT on the recipient's immune system has remained elusive. Soluble HLA class I (sHLA-I), HLA class II (sHLA-II), and Fas ligand (sFasL) molecules may play immunoregulatory roles. We determined by double-determinant immunoenzymatic assay (DDIA) sHLA-I, sHLA-II, and sFasL concentrations in different blood components. sHLA-I and sFasL levels in red blood cells (RBCs) stored for up to 30 days and in random-donor platelets are significantly (P <.001) higher than in other blood components and their amount is proportionate to the number of residual donor leukocytes and to the length of storage. Blood components with high sHLA-I and sFasL levels play immunoregulatory roles in vitro as in allogeneic mixed lymphocyte responses (MLR) and antigen-specific cytotoxic T-cell (CTL) activity, and induce apoptosis in Fas-positive cells. These data suggest that soluble molecules in blood components are functional. If these results are paralleled in vivo, they should be taken into account in transfusion practice. Blood components that can cause immunosuppression should be chosen to induce transplantation tolerance, whereas blood components that lack immunosuppressive effects should be preferred to reduce the risk of postoperative complications and cancer recurrence.  (+info)

Bone marrow transplantation in pediatric patients with therapy-related myelodysplasia and leukemia. (5/9074)

Eleven children underwent BMT for therapy-related MDS or leukemia, four from HLA-identical siblings and seven from unrelated donors. Ten of the 11 were conditioned with busulfan and cyclophosphamide as the majority had received prior irradiation to the chest and/or abdomen. All patients engrafted. Regimen-related toxicity was more common when compared to historical controls. Eight patients developed acute GVHD and four of eight who survived 100 days post transplant developed extensive chronic GVHD. Non-relapse related mortality occurred in three patients. Five patients developed recurrent malignancy: one died from recurrence of osteosarcoma, three died of recurrent leukemia or MDS and another developed two subsequent malignancies (duodenal carcinoma and anaplastic astrocytoma). Three survive disease-free at 14+, 22+ and 43+ months for a 2 year actuarial cancer-free survival of 24% (95% confidence interval = 5-53%). Although allogeneic BMT can be curative, regimen-related toxicity is frequent and recurrent malignancy remains the major obstacle.  (+info)

Risk factors for severe hemorrhagic cystitis following BMT. (6/9074)

Hemorrhagic cystitis (HC) is a common toxicity of preparative regimens for bone marrow transplantation (BMT). Severe HC often requires prolonged and expensive hospitalization, and occasionally can result in death. To investigate the risk factors for severe HC, we conducted a retrospective study among 1908 patients who received BMTs at the University of Minnesota during 1974 to 1993. A previous report from our institution reported on 977 of these patients. We identified all patients with genitourinary complication within 100 days post-BMT from the BMT database. Medical charts for these patients were reviewed to determine whether the patient had HC and also the grade of HC. A total of 208 HC cases were identified during the study period. Of them, 92 patients had severe HC, an incidence of 5% (95% CI = 4-6%). We found that grade II-IV graft-versus-host disease (RR = 2.56; 95% CI = 1.43-4.56), use of busulfan (RR = 2.69; 95% CI = 1.35-5.35), and age at transplant (RR = 2.20; 95% CI = 1.27-3.81, for age of 10-30 compared to age of 0-9) were related to an increased risk of HC. In contrast, transplant year was inversely associated with the risk of HC (trend test, P < 0.01). We did not find any significant difference in HC with the use of prophylactic Mesna.  (+info)

The clinical utility of CMV surveillance cultures and antigenemia following bone marrow transplantation. (7/9074)

At our institution, the cytomegalovirus (CMV) prophylaxis protocol for allogeneic bone marrow transplant (BMT) recipients who are CMV-seropositive or receive marrow from a CMV-seropositive donor consists of a surveillance bronchoscopy approximately 35 days posttransplant. Patients with a positive surveillance bronchoscopy for CMV receive pre-emptive ganciclovir. In order to determine the utility of other screening methods for CMV, we prospectively performed weekly CMV antigenemia, and blood, urine and throat cultures from time of engraftment to day 120 post-BMT in 126 consecutive patients. Pre-emptive ganciclovir was given to 11/81 patients (13.6%) because of a positive surveillance bronchoscopy for CMV. Results of CMV blood, urine and throat cultures and the antigenemia assay done prior to or at the time of the surveillance bronchoscopy were analyzed for their ability to predict the bronchoscopy result. The antigenemia test had the highest positive and negative predictive values (72% and 96%, respectively). The ability of these tests to predict CMV disease was evaluated in the 70 patients with a negative surveillance bronchoscopy who did not receive pre-emptive ganciclovir. Of 19 cases of active CMV disease, CMV antigenemia was positive in 15 patients (79%) a mean of 34 days preceding symptoms. Blood cultures were positive in 14/19 patients (74%) a mean of 31 days before onset of disease. CMV antigenemia is useful for predicting the surveillance bronchoscopy result, and also predicts the development of CMV disease in the majority of patients missed by the surveillance bronchoscopy.  (+info)

Disappearance of lupus anticoagulant after allogeneic bone marrow transplantation. (8/9074)

Lupus anticoagulant antibodies have never been reported to disappear after either allogeneic or autologous bone marrow transplantation in humans. We report the first case of disappearance of lupus anticoagulant antibodies in a patient without systemic lupus erythematosus or clinical evidence of other autoimmune disorders, who received an allogeneic bone marrow transplant as treatment for chronic myeloid leukemia. Although marrow transplantation is not a recognized therapy for antiphospholipid syndrome, our observation should be considered another example of the capability of intensive chemo-radiotherapy followed by stem cell transplantation to ablate a pathologic marrow clone resulting in an autoimmune disorder and improve, or even cure, some severe autoimmune diseases.  (+info)