Biomedical subjects
Publications and source records attributed to R J Jones.
There are many causes of a low serum caeruloplasmin. Not only may this be a feature of Wilson's disease, but a low level may be found in association with chronic liver disease of any cause. We report here a case where undetectable serum caeruloplasmin was found during routine investigation of a woman with hepatitis C viral infection.
Many institutions worldwide are conducting clinical studies using immunoablative therapy followed by hematopoietic stem cell transplantation for the treatment of SLE. Interpretation of these studies will be complicated by the differences in patient selection, conditioning regimens, and the method of stem cell collection. A major concern with this approach is that autoreactive effector cells will be re-infused with the autologous graft. The recent demonstration that immunoablative therapy (cyclophosphamide 200 mg/kg) can be safely delivered without the need for stem cell rescue offers a potential way to circumvent this problem. Early results employing immunoablative therapy, with or without stem cell rescue, are encouraging; however, longer follow-up and additional patients are necessary to validate this approach.
Our understanding of the complex signal transduction pathways involved in signalling within cancer cells, between cancer cells and between cancer cells and their environment has increased dramatically in recent years. Here we concentrate on three non-receptor kinases: Src, focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI 3-kinase). These form part of a complex network of intracellular signals which is thought to be important in regulating cancer cells.
BACKGROUND: Benign ureteral strictures are a potentially difficult problem that typically has been solved by open surgery. However, minimally invasive methods would be preferable. PATIENTS AND METHODS: Three patients with benign ureteral strictures were treated with endoscopic placement of self-expanding permanent indwelling stents (Wallstents). The etiologies of the obstruction were multifactorial and included retroperitoneal fibrosis, stones, traumatic ureteroscopy, ureteral ischemia, and previous open surgery. RESULTS: One patient died with a functioning stent 1 year, 7 months after placement. The other two patients are doing well 5 years, 2 months and 5 years, 11 months afterward (mean 51 months). CONCLUSION: Insertion of a permanent indwelling self-expanding ureteral stent is relatively easy, and long-term successes are documented. Placement of Wallstents for benign ureteral strictures should be considered as a treatment alternative.
Despite increasing evidence of benefit from adjuvant chemotherapy, older women with breast cancer are commonly given less aggressive treatment than younger patients. Conflicting prior data regarding age-related toxicity prompted this prospective study. Forty-four women (aged 35-79 years) with early-stage breast cancer were treated with four cycles of adjuvant therapy with doxorubicin 60 mg/m2 i.v. and cyclophosphamide 600 mg/m2 i.v. every 21 days. They were monitored for myelosuppression, cardiotoxicity, and decrease in quality of life. Pharmacokinetics were analyzed using cycle 1 plasma samples. Bone marrow granulocyte and macrophage colony-forming units (CFU-GM) were assayed in vitro for dose response to 4-hydroperoxycyclophosphamide and doxorubicin before cycle 1. There was moderate evidence of age-related decrease in nadir absolute neutrophil count (ANC) when age was viewed as a continuous variable. On average there was a 10/microliter drop in cycle 1 nadir ANC for every year increase in age (p = 0.02). However, when age was viewed as a categorical variable (age < 65 vs. > or = 65 years), a similar proportion of women in each group reached an ANC < 100 (18% vs. 19%). Neither neutropenic complications, alteration in cardiac function, nor change in quality of life scores were significantly age related (p > 0.12). Pharmacokinetic analyses did not demonstrate age-related differences in the clearance of either doxorubicin or cyclophosphamide (p > 0.8). Pharmacodynamic analysis of individual patient bone marrow progenitor cell sensitivity did not reveal any correlation with age (p > 0.48). In women undergoing adjuvant therapy for breast cancer, no clinically significant age-related trends in toxicity were observed. These data suggest that older age alone should not exclude patients from receiving adjuvant therapy with doxorubicin and cyclophosphamide.
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Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal stem cell disorder caused by a somatic mutation of the PIGA gene. The product of this gene is required for the biosynthesis of glycosylphosphatidylinositol (GPI) anchors; therefore, the phenotypic hallmark of PNH cells is an absence or marked deficiency of all GPI-anchored proteins. Aerolysin is a toxin secreted by the bacterial pathogen Aeromonas hydrophila and is capable of killing target cells by forming channels in their membranes after binding to GPI-anchored receptors. We found that PNH blood cells (erythrocytes, lymphocytes, and granulocytes), but not blood cells from normals or other hematologic disorders, are resistant to the cytotoxic effects of aerolysin. The percentage of lysis of PNH cells after aerolysin exposure paralleled the percentage of CD59(+) cells in the samples measured by flow cytometry. The kinetics of red blood cell lysis correlated with the type of PNH erythrocytes. PNH type III cells were completely resistant to aerolysin, whereas PNH type II cells displayed intermediate sensitivity. Importantly, the use of aerolysin allowed us to detect PNH populations that could not be detected by standard flow cytometry. Resistance of PNH cells to aerolysin allows for a simple, inexpensive assay for PNH that is sensitive and specific. Aerolysin should also be useful in studying PNH biology.
Paraneoplastic pemphigus (PNP) is a refractory and life-threatening autoimmune mucocutaneous disease. We have recently reported the effectiveness and safety of ablative intravenous cyclophosphamide (200 mg/kg daily over 4 days) without stem cell rescue in patients with refractory autoimmune diseases including systemic lupus erythematosus, autoimmune cytopenias, chronic inflammatory demyelinating polyneuropathy, and aplastic anemia. We report chronic lymphocytic leukemia-associated PNP in a patient who presented with extensive and debilitating painful oral ulcerations and received ablative therapy. The patient tolerated the regimen well and showed a slow but sustained improvement despite persistence of the underlying neoplasm. Eighteen months after therapy, the oral ulcerations were almost completely healed and the circulating autoantibodies became negative. Currently, the patient remains on cyclosporine and a low dose of prednisone. This provides further evidence for the efficacy and safety of this regimen in the management of severe autoimmune diseases including PNP.
Autologous bone marrow transplantation (BMT) has not been curative in chronic myeloid leukemia (CML), because of the inability to purge CML from the autograft and the absence of the allogeneic T cell-mediated antileukemic activity. However, recent advances demonstrate that normal progenitors can be selected from CML marrows by a variety of techniques, including isolation by their small size. Furthermore, we found that myeloid growth factors have a potent antileukemic effect against CML progenitors in vitro by inducing their terminal differentiation. Based on these data, we initiated a trial of autologous BMT in patients with high-risk CML. Autografts were processed in an attempt to enrich for normal progenitors, first by isolating small cells by counterflow centrifugal elutriation and then incubating them in granulocyte-macrophage colony-stimulating factor (GM-CSF) for 72 hours. After a conditioning regimen of busulfan and cyclophosphamide, all patients received GM-CSF daily for 2 months. The median age of the 13 patients in the trial was 45 years (range 17-56 years). The median duration of disease before BMT was 24 months (range 13-72 months). Eight patients were in chronic phase (CP), and five were in accelerated phase (AP). All patients failed to achieve a cytogenetic response to interferon-alpha and were 100% Philadelphia chromosome (Ph)+ before BMT. There were three transplant-related deaths, all AP patients. All of the remaining 10 patients engrafted with some degree of Ph- hematopoiesis; despite high-risk features, nine patients engrafted 100% Ph-. All patients relapsed cytogenetically at a median of 6 months (range 4-22 months). These results demonstrate that autologous BMT can consistently induce complete Ph- engraftment in CP patients. GM-CSF appears to produce a clinical antileukemic effect against CML after autologous BMT.
PURPOSE: The chemical, enzymatic, and biological stabilities and physical properties of a series of salicylate and aryl ester prodrugs of the antiviral agent, cyclic HPMPC, were evaluated to support the selection of a lead compound for clinical development. METHODS: Chemical stabilities of the prodrugs in buffered solutions at 37 degrees C were determined. Stability was also studied in the presence of porcine liver carboxyesterases (PLCE) at pH 7.4 and 25 degrees C. Tissue stabilities were examined in both human and dog intestinal homogenates, plasmas and liver homogenates. Prodrug and product concentrations were determined by reverse phase HPLC. RESULTS: Chemical degradation of the prodrugs resulted in the formation of both cyclic HPMPC and the corresponding HPMPC monoester. Chemical stability was dependent on the orientation of the exo-cyclic ligand; the equatorial isomers were 5.4- to 9.4-fold more reactive than the axial isomers. In the presence of PLCE, the salicylate prodrugs cleaved exclusively to give cyclic HPMPC and not the HPMPC monoester. In plasma, but not intestinal or liver homogenates, the salicylate esters of cyclic HPMPC cleaved readily with a rate dependent on the chain length of the alkyl ester substituent. CONCLUSIONS: The carboxylate function on the salicylate prodrugs of cyclic HPMPC provides an additional handle to chemically modify the lipophilicity, solubility and the biological reactivity of the prodrug. In tissue and enzymatic studies, the major degradation product is cyclic HPMPC. The salicylate ester prodrugs are attractive drug candidates for further in vivo evaluation.
To date, 16 in utero hematopoietic stem cell (HSC) transplants for diseases other than immunodeficiency disorders have been reported. No therapeutic level of engraftment was detected in 15 of these transplants. To overcome engraftment failure, we transplanted a very large number (5 billion paternal CD34+ cells/kg) of HSCs to a fetus with leukodystrophy during the first trimester of gestation. As reported previously, the fetus died in utero 7 weeks after the procedure and the cause of death appeared to be overwhelming donor engraftment. In the present investigation, we developed a human-murine chimera model to test for the optimal donor cell dose for human in utero transplantation. We found a strong correlation between the level of donor engraftment in three human fetuses transplanted for leukodystrophy during the first trimester of gestation and the results of parallel xenotransplants of the same human donor cells using the NOD/SCID mouse model. This small animal model appears to predict both extremes of hyperengraftment (seen in the first human fetus transplanted) and engraftment failure (seen in the second and third human fetuses transplanted in utero). These and future correlated clinical and laboratory assay results may be useful for the development of in utero transplants for a variety of congenital disorders.
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BACKGROUND: Immunoablative high-dose cyclophosphamide without stem-cell rescue induces durable, complete remission in most patients with aplastic anemia. OBJECTIVE: To determine the efficacy of high-dose cyclophosphamide in various refractory, severe autoimmune diseases. DESIGN: Prospective phase II study. SETTING: Johns Hopkins University (Baltimore, Maryland) and Hahnemann University (Philadelphia, Pennsylvania). PATIENTS: Eight patients with refractory, severe autoimmune disease. INTERVENTION: Immunoablative high-dose cyclophosphamide (50 mg/kg of body weight per day) for 4 consecutive days. MEASUREMENTS: Clinical and laboratory variables of autoimmune disease. RESULTS: Seven patients improved markedly: Five achieved complete remission and two achieved partial remission. Four patients have remained in continuous complete remission for 3 to 21 months, and two patients in partial remission continue to improve after 14 and 19 months of follow-up. High-dose cyclophosphamide was well tolerated; median times to a neutrophil count of 0.5 x 10(9) cells/L and platelet transfusion independence were 17 and 16 days, respectively. CONCLUSIONS: Immunoablative high-dose cyclophosphamide without stem-cell rescue can induce complete remission in patients with refractory, severe autoimmune disease. Reemergence of marrow function is similar to that seen after autologous transplantation and does not carry the risk for reinfusion of autoaggressive lymphocytes with the autograft.
Acute bleeding after bone marrow transplantation (BMT) was investigated in 1,402 patients receiving transplants at Johns Hopkins Hospital between January 1, 1986 and June 30, 1995. Bleeding categorization was based on daily scores of intensity used by the blood transfusion service. Moderate and severe episodes were analyzed for bleeding sites. Analysis of the cause of death and the interval of the bleeding episode to outcome endpoints was recorded. Survival estimates were computed for 1,353 BMT patients. The overall incidence was 34%. Minor bleeding was seen in 10.6%, moderate bleeding was seen in 11.3%, and severe bleeding was seen in 12% of all patients. Fourteen percent of patients had moderate or severe gastrointestinal hemorrhage, 6.4% had moderate or severe hemorrhagic cystitis, 2.8% had pulmonary hemorrhage, and 2% had intracranial hemorrhage. Sixty-one percent had 1 bleeding site and 34.4% had more than 1 site. Moderate and severe bleeding was more prevalent in allogeneic (31%) and unrelated patients (62.5%) compared with autologous patients (18.5%). Significant distribution of incidence was found among the different diagnoses, but not by disease status in acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, Hodgkin's disease, and non-Hodgkin's lymphoma. Bleeding was associated with significantly reduced survival in allogeneic, autologous, and unrelated BMT and in each disease category except multiple myeloma. Survival was correlated with the bleeding intensity, bleeding site, and the number of sites. Although close temporal association was evident to mortality, bleeding was recorded as the cause of death in only the minority of cases compared with other toxicities after BMT (graft-versus-host disease, infections, and preparative regimen toxicity). Acute bleeding is a common complication after BMT that is profoundly associated with morbidity and mortality. Although bleeding was not a direct cause of death in the majority of cases, it has a potential prognostic implication as a predictor of poor outcome in clinical assessment of patients after BMT.
Two patients with multiple myeloma in relapse after allogeneic BMT received donor lymphocyte infusions (DLI) but later required chemotherapy for treatment of myeloma-related complications. In both patients, recovery from chemotherapy-induced aplasia was accompanied by manifestations of graft-versus-host reactions. The first patient developed grade II acute GVHD and a complete remission which has lasted >22 months. The second patient developed grade III acute GVHD but died with co-existing GVHD and extensive extramedullary myeloma. These results demonstrate that chemotherapy does not nullify the ability of donor lymphocytes to mediate graft-versus-host reactions.
Although T cell depletion of allografts used in BMT has reduced GVHD, it has been associated with inferior engraftment and an increased risk of relapse. We have found that T cell depletion by counterflow centrifugal elutriation (CCE) also results in depletion of CD34+ stem cells. In order to determine if the discarded CD34+ cells would improve engraftment, we undertook a phase II trial of allogeneic BMT in which 110 patients (median age 43) with a variety of hematologic malignancies received CD34+ stem cell augmented, elutriated marrow grafts. The T cell-depleted grafts were tightly controlled and contained a mean of 4.3 x 10(7) mononuclear cells/kg, 3.3 x 10(6) CD34+ cells/kg, 1.5 x 10(5) CFU-GM/kg and 5.5 x 10(5) CD3+ T cells/kg. Median time to engraftment of granulocytes (>500/microl) was 16 days and of platelets (>50000/microl) was 25 days, comparable to that seen with unmanipulated marrow. No mixed hematopoietic chimerism was observed that was not associated with disease relapse. The four patients (3.6%) who failed to engraft were all at high risk because of prior donor transfusions or underlying marrow disorders. The incidence of GVHD was dependent on the duration of cyclosporin A (CsA) immunosuppression. In patients who received CsA for > or = 80 days, the incidence of clinically significant acute GVHD (>stage 1) and extensive, chronic GVHD was 5% and 11%, respectively. Peritransplant (< or = 100 day post-BMT) mortality for this group of patients was 15%. Event-free survival in selected subsets of patients compared favorably to previous studies in which patients received unmanipulated marrow allografts.
Despite extensive investigation into mechanisms of drug resistance in acute myeloid leukaemia (AML), the aetiology of therapeutic resistance is unclear. We found that five leukaemia cell lines (K562, HL-60, CEM. CEM induced to overexpress bcl-2, and REH) displayed parallel sensitivity to four antileukaemia drugs with different mechanisms of action, with K562 generally being the least sensitive and REH being the most sensitive. The amount of spontaneous apoptosis in the cell lines after serum-free culture paralleled their drug sensitivity: K562 cells displayed the least apoptosis at 24h (2.50 +/- 0.24%) and REH the most (24.47 +/- 8.22%). The extent of spontaneous apoptosis of leukaemic blasts from 39 patients with newly diagnosed de novo AML also correlated with the success of the intensive, infusional cytarabine-based induction therapy. There was a median of 19.5% (range 3.6-64%) apoptotic AML cells after 24 h of serum-free culture in patients who entered a complete remission compared with 4.2% (1.8-7.0%) apoptotic AML cells in patients who did not achieve a complete remission (P = 0.0007). Thus, inhibited apoptosis was associated with both in vitro and in vivo pan-resistance to antileukaemic chemotherapy. The cause of inhibited apoptosis in AML is probably a function of interactions among multiple signals that influence apoptosis. Assessment of spontaneous apoptosis may serve as an important prognostic factor for AML.
T cell depletion (TCD) performed by elutriation has decreased the incidence of acute and chronic graft-versus-host disease (GvHD) following bone marrow transplantation (BMT). However, as with all forms of TCD, patients may experience graft failure (10%), delayed engraftment, and mixed chimerism. Because 66%-75% of the CD34+ cells coseparate with the small lymphocytes, which are removed by elutriation, we designed a phase I trial in HLA-identical siblings to determine if the readdition of these previously lost small CD34+ cells would improve elutriation's engraftment kinetics. CD34+ cells were isolated from the small cell fraction of 10 consecutive donor grafts and infused into the recipients along with the TCD graft. The positively selected product had a mean T cell content of 1.2 x 10(5)/kg and was 80% CD34+, doubling the CD34+ content of the graft. All patients engrafted promptly with a median time to 500 neutrophils/mm3, untransfused 50,000 platelets/mm3, and discharge from the hospital of 19 (range 10-25), 24 (14-52), and 24 (18-29) days, respectively. Acute GvHD occurred in 2 patients, and no patient had chronic GvHD. Augmenting stem cell dose may be an efficient and safe alternative for overcoming TCD-associated delayed engraftment and graft failure, rather than increasing immunosuppression.