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Biomedical subjects

A Keating

Publications and source records attributed to A Keating.

At least 19 recordsLinked to original sources
PubMed2006

Irradiated KHYG-1 retains cytotoxicity: potential for adoptive immunotherapy with a natural killer cell line.

PURPOSE: To evaluate gamma-irradiation on KHYG-1, a highly cytotoxic natural killer (NK) cell line and potential candidate for cancer immunotherapy. METHODS AND MATERIALS: The NK cell line KHYG-1 was irradiated at 1 gray (Gy) to 50 Gy with gamma-irradiation, and evaluated for cell proliferation, cell survival, and cytotoxicity against tumor targets. RESULTS: We showed that a dose of at least 10 Gy was sufficient to inhibit proliferation of KHYG-1 within the first day but not its cytolytic activity. While 50 Gy had an apoptotic effect in the first hours after irradiation, the killing of K562 and HL60 targets was not different from non-irradiated cells but was reduced for the Ph + myeloid leukemia lines, EM-2 and EM-3. CONCLUSIONS: gamma-irradiation (at least 10 Gy) of KHYG-1 inhibits cell proliferation but does not diminish its enhanced cytolytic activity against several tumor targets. This study suggests that KHYG-1 may be a feasible immunotherapeutic agent in the treatment of cancers.

Cell Line↗
PubMed2006

Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for Cellular Therapy position statement.

The considerable therapeutic potential of human multipotent mesenchymal stromal cells (MSC) has generated markedly increasing interest in a wide variety of biomedical disciplines. However, investigators report studies of MSC using different methods of isolation and expansion, and different approaches to characterizing the cells. Thus it is increasingly difficult to compare and contrast study outcomes, which hinders progress in the field. To begin to address this issue, the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy proposes minimal criteria to define human MSC. First, MSC must be plastic-adherent when maintained in standard culture conditions. Second, MSC must express CD105, CD73 and CD90, and lack expression of CD45, CD34, CD14 or CD11b, CD79alpha or CD19 and HLA-DR surface molecules. Third, MSC must differentiate to osteoblasts, adipocytes and chondroblasts in vitro. While these criteria will probably require modification as new knowledge unfolds, we believe this minimal set of standard criteria will foster a more uniform characterization of MSC and facilitate the exchange of data among investigators.

Antigens, CD↗
PubMed2005

Clarification of the nomenclature for MSC: The International Society for Cellular Therapy position statement.

The plastic-adherent cells isolated from BM and other sources have come to be widely known as mesenchymal stem cells (MSC). However, the recognized biologic properties of the unfractionated population of cells do not seem to meet generally accepted criteria for stem cell activity, rendering the name scientifically inaccurate and potentially misleading to the lay public. Nonetheless, a bona fide MSC most certainly exists. To address this inconsistency between nomenclature and biologic properties, and to clarify the terminology, we suggest that the fibroblast-like plastic-adherent cells, regardless of the tissue from which they are isolated, be termed multipotent mesenchymal stromal cells, while the term mesenchymal stem cells is used only for cells that meet specified stem cell criteria. The widely recognized acronym, MSC, may be used for both cell populations, as is the current practice; thus, investigators must clearly define the more scientifically correct designation in their reports. The International Society for Cellular Therapy (ISCT) encourages the scientific community to adopt this uniform nomenclature in all written and oral communications.

Mesenchymal Stem Cells↗
PubMed2004

Long-term outcome after intensive therapy with etoposide, melphalan, total body irradiation and autotransplant for acute myeloid leukemia.

Intensive therapy and autologous blood and marrow transplantation (ABMT) is an established post-remission treatment for acute myeloid leukemia (AML), although its exact role remains controversial and few data are available regarding longer-term outcomes. We examined the long-term outcome of patients with AML transplanted at a single center using uniform intensive therapy consisting of etoposide, melphalan and TBI. In all, 145 patients with AML underwent ABMT: 117 in first remission, 21 in second remission and seven beyond second remission. EFS and OS were significantly predicted by remission status (P<0.0001). For transplantation in first remission, 8 year EFS and OS were 55% (95% CI, 44-64%) and 62% (95% CI, 50-72%), respectively. By multivariate analysis, only age (P=0.04) and cytogenetic risk group (P=0.006) influenced OS. For patients transplanted in second remission, 8 year EFS and OS were 30% (95% CI, 9-55%) and 36% (95% CI, 13-60%), respectively. No pre-transplant variables significantly predicted outcome. None of the seven patients who underwent ABMT beyond second remission or in early relapse were long-term survivors. ABMT can provide long-term antileukemic control for patients with AML in first remission. For patients in second remission approximately 30% can achieve cure with ABMT, and this option may be preferable to alternate donor allogeneic stem cell transplantation.

Acute Disease↗
PubMed2004

Subdural hematomas during CML therapy with imatinib mesylate.

Seven of one hundred twenty-one patients with chronic myeloid leukemia (CML) treated with imatinib mesylate developed subdural hematomas. All had advanced disease and were treated initially at a dose of 600 mg per day. Three patients had thrombocytopenia (platelet < 10 x 10(9)/l), one had leukocytosis (white blood cell count > 150 x 10(9)/l) and three had neither around the time of diagnosis of the subdural hematomas. Four patients required surgical evacuation. One patient, in blast crisis, died as a consequence of the subdural hematoma. Three patients survived but died of progressive CML. The remaining three patients having recommenced imatinib, are alive and well, and one has achieved a major cytogenetic response. Subdural hematomas must be considered even in mildly symptomatic patients receiving imatinib regardless of their peripheral blood counts. Patients who survive can be cautiously restarted on imatinib. Further studies are required to study the potential relationship between imatinib mesylate and subdural hematomas.

Aged↗
PubMed2003

Myeloablative conditioning regimens for AML allografts: 30 years later.

During the last three decades, several myeloablative conditioning regimens have been used for AML allografts. In this review, we systematically examine the data from studies reporting on myeloablative conditioning regimens for AML allografts. High-dose busulfan combined with cyclophosphamide (BuCy) and cyclophosphamide in combination with total body irradiation (CyTBI) are the two most commonly used conditioning regimens for AML allografts. From the available data, there are no significant differences in survival with these two regimens. A small benefit of decreased relapse rate with CyTBI is counterbalanced by a nonsignificant increase in treatment-related mortality. The incidence of veno-occlusive disease is significantly higher in patients treated with BuCy. Therapeutic monitoring of busulfan was not reported in any of the studies comparing the regimens. Either of the regimens can be used for AML allografts, and the choice may ultimately depend on local availability and expertise. Further improvements may be possible from modifications of the standard regimens. Data from these latter studies seem to be encouraging, but are not based on comparative randomized trials.

Acute Disease↗
PubMed2003

Autologous stem cell transplantation in multiple myeloma patients <60 vs >/=60 years of age.

The role of autologous stem cell transplantation (AuSCT) in older multiple myeloma patients is unclear. Using data from the Autologous Blood and Marrow Transplant Registry, we compared the outcome of 110 patients >/=the age of 60 (median 63; range 60-73) years, undergoing AuSCT with that of 382 patients <60 (median 52; range 30-59) years. The two groups were similar except that older patients had a higher beta(2)-microglobulin level at diagnosis (P=0.016) and fewer had lytic lesions (P=0.007). Day 100 mortality was 6% (95% confidence interval 4-9) and 1-year treatment-related mortality (TRM) was 9% (6-13) in patients <60 years, compared with 5% (2-10) and 8% (4-14), respectively, in patients >/=60 years. The relapse rate, progression-free survival (PFS) and overall survival (OS) in the two groups were also similar. Multivariate analysis of all patients identified only an interval from diagnosis to AuSCT >12 months and the use of two prior chemotherapy regimens within 6 months of AuSCT as adverse prognostic factors. Our results indicate that AuSCT can be safely performed in selected older patients: the best results were observed in patients undergoing AuSCT relatively early in their disease course.

Adult↗
PubMed2002

Cyclophosphamide, etoposide and G-CSF to mobilize peripheral blood stem cells for autologous stem cell transplantation in patients with lymphoma.

We aimed to assess the effectiveness of cyclophosphamide, etoposide and G-CSF (C+E) to mobilize peripheral blood stem cells for autologous stem cell transplantation in patients with lymphoma. A matched cohort study was performed comparing patients mobilized with C+E to patients mobilized with cyclophosphamide and G-CSF (C alone). Patients were matched for disease, prior radiotherapy and a chemotherapy score reflecting the amount and type of prior chemotherapy. Thirty-eight consecutive patients mobilized with C+E were compared with 38 matched controls. C+E was equivalent to C alone in terms of numbers of patients achieving a minimum threshold of > or =2 x 10(6)/kg CD34(+)cells (82% vs 79%, P = 0.74). C+E was superior, however, in terms of total CD34(+) yield (6.35 vs 3.3 x 10(6)/kg, P < 0.01), achieving a target graft of > or =5 x 10(6)/kg (55% vs 34%, P = 0.04) and obtaining both a minimum (61% vs 32%, P < 0.01) and target (45% vs 13%, P < 0.01) graft in one apheresis. This superiority was largely confined to patients with lower chemotherapy scores. There was no difference in neutrophil and platelet recovery or transfusion requirements for those who subsequently received high-dose therapy and stem cell transplantation. Thus, C+E improves the efficiency of peripheral blood stem cell collection, but does not increase the number of patients who can proceed to transplantation. Most of the benefit of the regimen was confined to patients who had not received extensive prior therapy. Novel strategies are required to increase the collection efficiency of 'hard to mobilize' patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

W/Wv marrow stromal cells engraft and enhance early erythropoietic progenitors in unconditioned Sl/Sld murine recipients.

Transplantation of marrow stromal cells may provide a means of modulating hematopoiesis and serve as a form of cell therapy. We employed a murine transplant model using Sl/Sl(d) mice, which have macrocytic anemia due to defective expression of stem cell factor (SCF) on bone marrow stromal cells. Donor cells were derived from the complementary mutant strain W/W(v), which also exhibit anemia, due to mutations in c-kit, the SCF receptor expressed on hematopoietic stem cells. The strength of this model is that any correction of the Sl/Sl(d) anemia from the infusion of W/W(v) stromal cells can be attributed to the effect of the stromal cells and not to contaminating W/W(v) hematopoietic stem cells, a major concern in experiments involving wild-type animals. Cultured stromal cells were infused into unconditioned non-splenectomized Sl/Sl(d) mice. Engraftment of donor stromal cells reached levels of up to 1.0% of total marrow cells 4 months post transplant. However, stromal engraftment was not detectable in the spleen. Recipients of W/W(v) stroma showed a significant increase in the committed erythroid progenitors compared with those receiving Sl/Sl(d) stromal cells: 109 +/- 26 vs 68 +/- 5 CFU-E per 10(5) BMC, P = 0.002; 25 +/- 10 vs 15 +/- 5 BFU-E per 10(5) BMC, P = 0.037, for W/W(v) and Sl/Sl(d) stroma recipients, respectively. Despite this increase in erythroid progenitors, the anemia was not corrected. Our data suggest that in this murine model, splenic erythropoiesis may influence stromal cell therapy, and that higher levels of marrow engraftment may be necessary to obtain a clinically significant effect.

Anemia, Macrocytic↗
PubMed2002

'Relative' chemotherapy sensitivity: the impact of number of salvage regimens prior to autologous stem cell transplant for relapsed and refractory aggressive non-Hodgkin's lymphoma.

The purpose of the study was to assess the impact of number of salvage regimens needed to demonstrate chemotherapy sensitivity on relapse rates, survival, and toxicity following high-dose therapy and autologous bone marrow transplantation (ABMT) in relapsed or refractory non-Hodgkin's lymphoma. We retrospectively reviewed 136 patients with intermediate-grade lymphoma who underwent ABMT. All patients were treated with salvage therapy to maximum tumor reduction. Three quarters (102/136) of the patients received one salvage regimen, while 31 (23%) patients received two or more regimens. When compared to patients requiring >or= two regimens, patients requiring only one salvage regimen to demonstrate chemosensitivity were more likely to have a longer previous CR from initial therapy (CR >or=12 months in 47% vs 26%; P = 0.04) and to have attained CR with salvage (54% vs 16%; P = 0.001). Both median relapse-free survival (RFS) and overall survival (OS) have not yet been reached in patients receiving one salvage regimen (median follow-up 50.6 months). This is superior to the median RFS of 9.1 months (P = 0.004) and OS of 11.1 months in patients requiring >or=two regimens to demonstrate chemosensitivity (P = 0.002). Time to engraftment, toxic deaths and incidence of myelodysplasia were similar in the groups. The survival rate observed in patients requiring >or=two salvage regimens, although inferior to that of patients receiving a single salvage regimen, are still generally superior to results in the literature for patients treated with chemotherapy alone without ABMT. We conclude that high-dose therapy with ABMT is appropriate for lymphoma patients even when disease reduction requires repeated numbers of salvage regimens.

Adult↗
PubMed2001

Illness intrusiveness among survivors of autologous blood and marrow transplantation.

BACKGROUND: Illness-induced disruptions to lifestyles, activities, and interests (i.e., illness intrusiveness) compromise subjective well-being. The authors measured illness intrusiveness in autologous blood and bone marrow transplantation (ABMT) survivors and compared the results with survivors of solid organ transplants. METHODS: Forty-four of 64 consecutive ABMT survivors referred to the University of Toronto ABMT long-term follow-up clinic completed the Illness Intrusiveness Ratings Scale (IIRS), the Affect Balance Scale (ABS), the Atkinson Life Happiness Rating (ATKLH), the Beck Hopelessness Scale (BHS), and the Center for Epidemiologic Studies Depression (CES-D) Scale. Mean time from ABMT to evaluation was 4.6 +/- 2.8 years. All patients were in remission or had stable disease at the time of evaluation. Autologous blood and bone marrow transplantation patients' IIRS scores were compared with scores reported by recipients of kidney (n = 357), liver (n = 150), lung (n = 77), and heart (n = 60) transplants. RESULTS: Mean IIRS score for the 44 ABMT patients was 37.2 +/- 17 (maximum possible score, 91; minimum possible score, 13). Higher IIRS scores correlated with lower scores on the ABS (r = -0.54; P < 0.0001), and ATKLH (r = -0.44; P = 0.004), and with higher scores on the BHS (r = 0.58; P < 0.0001) and CES-D (r = 0.48; P < 0.0001). The authors compared IIRS scores from the ABMT survivors with scores from recipients of solid organ transplants. Scores were corrected for age, gender, and time from transplant to evaluation. Corrected mean IIRS scores for the marrow (37.5), kidney (38.9), heart (40.0), lung (30.1), and liver (32.3) transplant recipients differed significantly (P < 0.0001 by analysis of covariance). Higher scores among marrow, kidney, and heart transplant survivors were caused by increased scores in the instrumental domain of the IIRS that measures disruptions in health, work, financial situation, and active recreation. CONCLUSIONS: Despite achieving a remission after ABMT, patients continue to experience illness intrusiveness compromising subjective well-being.

Activities of Daily Living↗
PubMed2001

Autologous transplantation for diffuse aggressive non-Hodgkin's lymphoma in patients never achieving remission: a report from the Autologous Blood and Marrow Transplant Registry.

PURPOSE: To evaluate the results of high-dose chemotherapy and autologous hematopoietic stem-cell transplantation (autotransplants) in patients with diffuse aggressive non-Hodgkin's lymphoma (NHL) who never achieve a complete remission with conventional chemotherapy. PATIENTS AND METHODS: Detailed records from the Autologous Blood and Marrow Transplant Registry (ABMTR) on 184 patients with diffuse aggressive NHL who never achieved a complete remission with conventional chemotherapy and subsequently received an autotransplant were evaluated. Transplants were performed between 1989 and 1995 and were reported to the ABMTR by 48 centers in North and South America. RESULTS: Seventy-nine (44%) of 184 patients achieved a complete remission or a complete remission with residual imaging abnormalities of unknown significance after autotransplantation. Thirty-four (19%) of 184 had a partial remission and 55 (31%) of 184 had no response or progressive disease. Eleven patients (6%) were not assessable for response because of early death. The probabilities of progression-free and overall survival at 5 years after transplantation were 31% (95% confidence interval [CI], 24% to 38%) and 37% (95% CI, 30% to 45%), respectively. In multivariate analysis, chemotherapy resistance, Karnofsky performance status score less than 80 at transplantation, age > or = 55 years at transplantation, receiving three or more prior chemotherapy regimens, and not receiving pre- or posttransplant involved-field irradiation therapy were adverse prognostic factors for overall survival. CONCLUSION: High-dose chemotherapy and autologous hematopoietic stem-cell transplantation should be considered for patients with diffuse aggressive NHL who never achieve a complete remission but who are still chemotherapy-sensitive and are otherwise transplant candidates.

Adolescent↗
PubMed2001

The effect of graft purging with 4-hydroperoxycyclophosphamide in autologous bone marrow transplantation for acute myelogenous leukemia.

BACKGROUND: Autologous bone marrow transplantation is an important therapy for patients with acute myelogenous leukemia (AML). However, leukemia in the graft may contribute to posttransplant relapse. Treatment of the graft with 4-hydroperoxycyclophosphamide (4HC) is sometimes used to decrease numbers of infused leukemia cells (4HC purging). No large controlled trials evaluating efficacy and toxicity of 4HC purging are reported. METHODS: We studied 294 patients reported to the Autologous Blood and Marrow Registry receiving either a 4HC-purged (n = 211) or unpurged (n = 83) autograft for AML in first (n = 209) or second (n = 85) remission. Analyses were restricted to patients transplanted less than 6 months after achieving remission. Using Cox proportional hazards regression, we compared time to treatment failure (death or relapse, inverse of leukemia-free survival) after 4HC-purged vs unpurged transplants while controlling for important prognostic factors. RESULTS: Median duration of posttransplant neutropenia was 40 (range, 10-200) days after 4HC-purged transplants and 29 (9-97) days after unpurged transplants (p < 0.01). Transplant-related mortality was similar in the two groups. In multivariate analysis, patients receiving 4HC-purged transplants had lower risks of treatment failure than those receiving unpurged transplants (relative risk, 0.69, p = 0.12 in the first posttransplant year; relative risk, 0.28, p < 0.0001 thereafter). Adjusted three-year probabilities of leukemia-free survival (95% confidence interval) were 56% (47-64%) and 31% (18-45%) after 4HC-purged and unpurged transplants in first remission, respectively. Corresponding probabilities in second remission were 39% (25-53%) and 10% (1-29%). CONCLUSION: Grafts purged with 4HC are associated with higher leukemia-free survival after autologous bone marrow transplants for AML.

Acute Disease↗
PubMed2001

Radiation-associated pneumonitis following autologous stem cell transplantation: predictive factors, disease characteristics and treatment outcomes.

High-dose therapy followed by autologous stem cell transplantation (ASCT) prolongs survival in patients with multiple myeloma and is relatively safe with treatment-related mortality rates of only 1-5%. Interstitial pneumonitis (IP) is normally an infrequent complication of ASCT with a reported incidence of 0-16%. Between 1992 and 1998, 94 myeloma patients at our center underwent ASCT using a high-dose regimen of etoposide (60 mg/kg), melphalan (160 mg/m2) and fractionated TBI 12 Gy. An unusually high incidence of IP (29/94 (31%)) was noted. Mortality in the IP patients was high at 45%. Patients developing IP were more frequently anemic than those who did not have pulmonary complications (hemoglobin <100 g/l) prior to transplant (P = 0.03) but no other pre-transplant factors were predictive (ie age, gender, smoking history, CMV status, pulmonary function, creatinine, beta2-microglobulin or C-reactive protein, prior cumulative chemotherapy or chest irradiation). A significantly lower IP rate was noted in 32 contemporaneous myeloma control patients conditioned with BU-CY without TBI at our center (3/32 (9%); P=0.03) and in 32 lymphoma control patients conditioned with the same melphalan and etoposide regimen minus the TBI (2/32 (6%); P = 0.003). In contrast, when using the same TBI-containing regimen in 32 concurrently treated lymphoma patients, an increase in IP similar to that seen in our myeloma cohort (7/32 (22%); P = 0.3) was noted. This strongly suggests that TBI is the predominant factor contributing to lung toxicity. We conclude that radiation-associated pneumonitis cannot be easily predicted by pretransplant variables. Therefore surveillance, early recognition and prompt therapy are recommended.

Adult↗
PubMed2001

Decreased bone mineral density is common after autologous blood or marrow transplantation.

Survivors of autologous blood or marrow transplantation (ABMT) are predisposed to decreased bone mineral density (BMD), but data are lacking on the incidence and risk factors for this condition. Therefore, we measured BMD in 64 of 68 consecutive ABMT survivors (35 men and 29 women) attending the University of Toronto ABMT long-term follow-up clinic. Patients were evaluated a median of 4.2 years (range: 4.9 months-11.4 years) after ABMT. Median age at evaluation was 49.6 years (range: 23.5-68.2 years). At the L1-L4 vertebrae, 17 (26%) patients (eight men and nine women) had osteopenia and one male (2%) had osteoporosis. Mean BMD at L1-L4 did not differ from healthy young adults or age and sex matched controls. At the femoral neck, 30 patients (46%) (18 men and 12 women) had osteopenia and five (8%) (two men and three women) had osteoporosis. Mean BMD at the femoral neck was significantly lower than in healthy young adults and age- and sex-matched controls. By regression analysis, patients with decreased BMD were older than those with normal BMD (P = 0.02). Gender, body mass index, time from BMT to evaluation and presence of hypogonadism were not associated with decreased BMD. Treatment of decreased bone density was instituted and follow-up data were obtained 1 year after treatment in 22 of 39 patients with reduced BMD. Nineteen (86%) patients had stabilization or improvement of their bone density at follow-up. We conclude that, after ABMT, over half of the patients have evidence of osteopenia or osteoporosis. Men and women were equally affected. In our study, only older age at evaluation was predictive for loss of BMD. We recommend the measurement of BMD as an integral component to the follow-up of ABMT patients.

Adult↗
PubMed2001

Autotransplants for histologically transformed follicular non-Hodgkin's lymphoma.

Histological transformation from a follicular non-Hodgkin's lymphoma (NHL) to a higher grade lymphoma carries a poor prognosis despite treatment with aggressive anthracycline-based chemotherapy. We retrospectively analysed 35 patients with histologically transformed NHL who underwent high-dose therapy and autotransplantation at our centre. Patients up to 65 years old were eligible for autotransplant at the time of transformation or with subsequent relapses, provided that chemosensitivity to a salvage regimen could be demonstrated. All patients received high-dose therapy [etoposide 60 mg/kg, melphalan 160 mg/m2 and fractionated total body irradiation (TBI) 12 Gy] followed by unpurged autologous bone marrow or blood stem cell rescue. Most patients (69%) had advanced stage disease (stages 3--4) at transformation and bone marrow involvement was common (49%). Twenty-six (74%) patients were in partial remission (PR) and nine (26%) in complete remission (CR) at the time of transplant. Median duration from transformation to transplant was 10.9 months (range, 5.2 months--4.6 years). At a median follow up of 52 months after autotransplant, 19 (54%) patients had died. Causes of death were progressive lymphoma in nine patients (26%), treatment-related mortality (TRM) in seven (20%) and myelodysplasia in three (8%). Only five patients in our cohort were > 60 years old, but all died as a result of treatment-related causes (mostly pulmonary infections). Five-year overall survival and progression-free survival from time of transplant were 37% and 36% respectively. Using multivariate analysis of factors including gender, age, stage, extranodal disease, disease bulk, B symptoms, number of prior therapies, relapse status and CR/PR status at transplant, only advanced age significantly predicted for survival from autotransplant (P = 0.002). Our survival data are comparable to previous reports of autotransplantation for transformed NHL and suggest a benefit over standard chemotherapy alone in selected patients. However, our high TRM cautions the use of aggressive therapy, including TBI, in patients over 60 years old.

Adult↗