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Biomedical subjects

H A Messner

Publications and source records attributed to H A Messner.

At least 37 records · Page 2Linked to original sources
PubMed2001

Differences in cell cycle kinetics of candidate engrafting cells in human bone marrow and mobilized peripheral blood.

Patients undergoing hematopoietic stem cell transplantation (HSCT) with mobilized peripheral blood (MPB) engraft quicker than those receiving bone marrow (BM). Our objective was to determine whether candidate engrafting cells--primitive hematopoietic progenitors (PHPs)--from MPB and BM exhibit different responses to cytokines that could explain this observation. We compared the cell cycle kinetics and ex vivo expansion of PHP-enriched cells obtained from MPB (n = 12) and BM (n = 10) by fluorescence-activated sorting of CD90+, AC133+ or CD38(dull) subsets of pre-selected CD34(+) cells. Cell cycle status, before and after 40 hours of serum-free culture with a cytokine cocktail, was assessed by multiparameter flow cytometry following incubation with Hoechst 33342 and pyronin Y. We found that 0.2% +/- 0.3% of MPB CD34(+)CD90(+) cells were in S/G(2)/M phases at hour 0, compared with 5% +/- 2.5% of those from BM (p = 0.0001), and 86.3% +/- 9.7% were in G(0), compared with 65.3% +/- 10% of those in BM (p = 0.0001). After 40 hours of culture, CD34(+)CD90(+) cells from MPB were more mitotically active than those from BM, with 29% +/- 4.9% in S/G(2)/M and 20% +/- 11.4% in G(0), compared to 19% +/- 6.5% (p = 0.001) and 39.2% +/- 22% (p = 0.027) of cells from BM. There was greater expansion of both total CD34(+) cells and the CD90(+) subset from MPB samples (p = 0.001 and 0.0001, respectively). Results from PHPs defined on the basis of AC133 expression correlated well with results obtained in CD90(+) subsets (r(2) = 0.81; p = 0.014).MPB PHPs appear to be primed for a greater acceleration in mitotic activity upon cytokine exposure. This qualitative difference may contribute to the earlier engraftment seen after HSCT using MPB grafts.

AC133 Antigen↗
PubMed2000

Bone marrow mobilized with granulocyte colony-stimulating factor in related allogeneic transplant recipients: a study of 29 patients.

We studied whether a short course of granulocyte colony-stimulating factor (G-CSF) administered to normal donors immediately before bone marrow (BM) harvest would shorten time to neutrophil and platelet engraftment in matched related allogeneic BM recipients. Twenty-nine normal donors received 4 consecutive daily subcutaneous injections of G-CSF (median dose, 12.1 microg/kg per day; range, 9.6-15.7 microg/kg per day) immediately before BM harvest. Donors tolerated G-CSF well, with only mild myalgias and arthralgias, and BM was easy to aspirate. The BM harvest contained a median of 5.3 x 10(8) white blood cells (WBCs)/kg (range, 3.1-11.1 x 10(8) WBCs/kg) and 2.5 x 10(6) CD34+ cells per kg (range, 1.5-7.3 x 10(6) CD34+ cells per kg). Median times to neutrophil (18 days [range, 11-30 days] versus 22 days [range, 16-36 days]; P = .05) and platelet (22 days [range, 15-55 days] versus 27 days [range, 18-46 days]; P = .04) engraftment were statistically shorter than those of historical control subjects whose donors had not received G-CSF before BM harvest. However, secondary engraftment-dependent outcomes including red blood cell and platelet transfusions, febrile days, days on antibiotics, days from transplant to hospital discharge, and days in hospital during the first 60 days after transplant were not statistically different from historical control subjects. We conclude that G-CSF administered to normal donors immediately before harvest facilitates BM aspiration, increases the WBC content of the harvest, and hastens neutrophil and platelet engraftment compared with historical control subjects.

Adolescent↗
PubMed2000

Accumulation of sestamibi in lymphoma cell lines in vitro.

Although some authors have suggested that sestamibi imaging is useful in evaluation of patients with lymphoma, others have obtained equivocal results. This discrepancy has been further investigated in vitro using two patient-derived non-Hodgkin's lymphoma cell lines, OCI-Ly3 and OCI-Ly18. Sestamibi (0.2 MBq/ml) was added to a suspension of OCI-Ly3 or OCI-Ly18 cells and aliquots were removed over 1 h and centrifuged to determine cell-associated radioactivity. Further experiments studied the effect of addition of a P-glycoprotein (Pgp) modulator or alteration in plasma and/or mitochondrial membrane potentials. Accumulation of sestamibi reached plateau values within 30 min, but these values were 6-fold higher in OCI-Ly3 than in OCI-Ly18. Inhibition of Pgp function with GG918 or PSC833 did not affect OCI-Ly3 cells but increased accumulation in OCI-Ly18 cells 3-fold, indicating a moderate level of Pgp. However, both cell lines responded similarly to membrane potential alterations: hyperpolarization of the mitochondrial membrane with nigericin had little effect on accumulation: in contrast, depolarization of the plasma membrane with an isotonic high potassium buffer reduced accumulation of sestamibi to 52% of control and additional depolarization of the mitochondrial membrane with valinomycin further reduced accumulation to 12% of control levels. These studies suggest that there can be wide differences in accumulation between cell lines, in part due to Pgp-mediated efflux, but that both of these cell lines have highly polarized mitochondria with little further capacity for hyperpolarization.

Biological Transport↗
PubMed1999

Nontargeted stable integration of recombinant adeno-associated virus into human leukemia and lymphoma cell lines as evaluated by fluorescence in situ hybridization.

A number of studies on human epithelial cells of varying origin have demonstrated integration of recombinant adeno-associated virus (AAV) vectors into a variety of chromosomes compared with the site-specific integration on chromosome 19 predominantly observed for wild-type (wt) AAV. We have constructed a recombinant AAV (rAAV) vector and tested the integration into hematopoietic cells, using the human acute myeloid leukemia cell line AML5 and the human non-Hodgkin's lymphoma cell line OCI-LY18 as targets. The integration sites were visualized by fluorescence in situ hybridization (FISH). Positive signals were observed for chromosomes 1, 2, 3, 8, 14, 15, 19, and Y. The majority of cells demonstrated integration into one specific site. A minority showed simultaneous integration into more than one chromosome. The frequency of observed integrations was not uniformly distributed among chromosomes; for instance, in AML5 chromosome 2 seemed to be favored. Colony-derived AML5 clones bore unique integration patterns indicating successful transduction of clonogenic progenitor cells with high proliferative potential. The integration was stable and observed for more than 12 months after transduction. FISH has been shown to be a powerful tool for detailed analyses of rAAV integration patterns and can be used to evaluate targets and transduction conditions.

Acute Disease↗
PubMed1999

Clonal heterogeneity of dendritic cells derived from patients with chronic myeloid leukemia and enhancement of their T-cells stimulatory activity by IFN-alpha.

Adoptive immunotherapy in form of donor leukocyte infusions is effective in a significant number of patients with chronic myeloid leukemia (CML) that have relapsed after allogeneic bone marrow transplantation (BMT). However, the therapy is associated with clinically significant side effects such as graft-versus-host disease (GVHD) and bone marrow (BM) hypoplasia that may be avoided through the administration of T cells with specific antileukemic activity. Dendritic cells (DC) functioning as potent antigen presenting cells (APC) may play an important role in the generation of T cells with specificity against CML. We examined a subpopulation of CD1a+/CD14- DC generated in vitro from BM of normal subjects and patients with CML using granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4). These DC derived from both the BM of normal subjects and of patients with CML, differentiated and matured in culture in a similar way. However, DC derived from patients with CML, displayed decreased activity when tested with allogeneic T cells in a mixed lymphocyte reaction (MLR). Addition of interferon-alpha (IFN-alpha) to DC cultures significantly upregulated the expression of major histocompatibility complex (MHC) molecules (class I and class II) and costimulatory molecules (B7.1 and B7.2) on DC from normal donors and CML patients. However, DC grown from CML patients required a higher concentration of IFN-alpha. IFN-alpha also significantly improved the capacity of CML DC to stimulate T-lymphocyte responses. Fluorescence in situ hybridization (FISH) showed that only some CD1a+/CD14- DC derived from BM of patients with CML expressed the bcr/abl fusion gene. Incubation with INF-alpha decreased the proportion of bcr/abl positive DC.

Antigens, CD↗
PubMed1999

Management of allogeneic bone marrow transplant recipients at risk for cytomegalovirus disease using a surveillance bronchoscopy and prolonged pre-emptive ganciclovir therapy.

BACKGROUND: Patients undergoing allogeneic bone marrow transplant (BMT) are considered to be at increased risk of cytomegalovirus (CMV) disease if they and/or their donor are CMV seropositive pre-transplant. Although several pre-emptive strategies have been shown to be effective in preventing early CMV disease, the ability of pre-emptive strategies using prolonged ganciclovir therapy to reduce the incidence of late-onset CMV infection, disease and mortality has not been fully evaluated. OBJECTIVE: To assess the efficacy of 18 weeks of pre-emptive ganciclovir therapy in preventing late-onset (> 100 days post-transplant) CMV disease when administered to asymptomatic BMT patients found to have CMV in bronchoalveolar lavage (BAL) fluid obtained during a surveillance bronchoscopy approximately 35 days post-transplant. To determine whether or not survival of BMT recipients is influenced by pre-transplant donor and recipient CMV serostatus in the context of this pre-emptive ganciclovir strategy. STUDY DESIGN: Consecutive patients undergoing allogeneic BMT were assessed for their risk of developing CMV disease based on their pre-transplant CMV serostatus and that of their donor. Patients who were CMV seropositive and/or received marrow from a CMV seropositive donor underwent a surveillance bronchoscopy and BAL approximately 35 days post-transplant. Patients with positive BAL fluid for CMV received pre-emptive ganciclovir therapy for 18 weeks at decreasing dose levels. Patients considered to be at low risk for the development of CMV disease (donor and recipient CMV seronegative) were followed without intervention. RESULTS: Of 98 consecutive patients, 55 were considered to be at risk for CMV disease and underwent a surveillance bronchoscopy. Sixteen (29%) patients had a positive BAL fluid for CMV and were started on pre-emptive ganciclovir therapy. Two patients progressed and died with CMV-related pneumonia. One additional patient developed CMV-related enteritis on day 42 post-transplant and recovered with continuing ganciclovir treatment. Of the 39 patients with a negative BAL fluid for CMV, one developed a fatal CMV pneumonia 150 days post-transplant and two additional patients developed gastrointestinal CMV disease 28 and 57 days post-BMT, respectively. None of the patients in the low risk group developed CMV disease. CONCLUSIONS: The strategy utilizing a surveillance bronchoscopy for CMV and initiating prolonged (18 weeks) pre-emptive ganciclovir therapy for patients with a positive BAL fluid for CMV resulted in a low incidence of CMV-related post-transplant complications. After a minimum follow-up of 16 months, late CMV reactivations (occurring > 100 days post-transplant) were not observed in the group of individuals pre-emptively treated with ganciclovir. This observation suggests that prolonged therapy with a reduced dose of ganciclovir may be important in the prevention of CMV reactivation. The CMV serostatus of donors and recipients prior to BMT did not correlate with survival.

Adult↗
PubMed1999

Comparative testing of peripheral blood and bone marrow for BCR-ABL transcripts in patients post allogeneic bone marrow transplantation and during interferon treatment for chronic myeloid leukemia.

Patients with CML post allogeneic BMT or during treatment with Interferon were monitored in bone marrow and peripheral blood for BCR-ABL transcripts by RT-PCR and in the majority of cases also by Southern blotting. Bone marrow and peripheral blood samples were obtained simultaneously and tested by RT-PCR with the objective to determine the usefulness to follow CML patients by testing peripheral blood rather than bone marrow samples. For the purpose of this study we have considered the test results obtained from bone marrow samples as the standard. A total of 111 CML patients were examined who underwent either an allogeneic BMT (n=91) or were treated with Interferon (n=20) amounting to a total of 163 assessments for BCR-ABL. Concordance of results was observed in 153 samples (93.9%). 10 samples showed discordance. Seven of these were subjected to repeat testing by RT-PCR. The previously obtained discordant results were confirmed. The sensitivity of peripheral blood assays was calculated to be 96.2% with a specificity of 89.5%. RT-PCR results restricted to Southern blot negative patients showed concordance of bone marrow and peripheral blood in 91.1% of tested samples with a sensitivity of 92.7% and a specificity of 88.6%. The subset of patients in which Southern blot testing was not available showed concordance at a similar level. Complete concordance was seen in all patients that were found to be positive by Southern blotting. We conclude from this study that peripheral blood testing for BCR-ABL transcripts by RT-PCR is a test with high sensitivity and specificity and may potentially replace bone marrow testing. This approach will probably result in a high level of acceptance by patients and may permit more frequent monitoring.

Blotting, Southern↗
PubMed1999

Three decades of allogeneic bone marrow transplants at the Princess Margaret Hospital.

A total of 1,122 patients with various hemopoietic disorders were transplanted at the Princess Margaret Hospital since 1970. The majority suffered from acute or chronic myeloid leukemia. Improvements in support strategies permitted a gradual escalation of the upper age limit for transplant candidates and resulted in better survival. The overall survival at 10 years of all patients transplanted consecutively either before or after 1986 increased from 30 to 50%. This change was observed independent of other transplant related risk factors and is predominantly attributable to the use of cyclosporine and ganciclovir. An improvement of similar magnitude was seen for transplant recipients presenting with good risk features. The 10-year survival of patients with acute and chronic myeloid leukemia transplanted from a fully matched sibling donor in first complete remission or first chronic phase increased from 40 to approximately 70%. The quality of life of surviving patients may not return to normal but appears to improve with time after the transplant.

Bone Marrow Transplantation↗
PubMed1998

Acute intestinal graft-versus-host disease in a syngeneic bone marrow transplant recipient.

BACKGROUND: We report a case of intestinal graft-versus-host disease (GVHD) in a syngeneic bone marrow transplant patient. METHODS: Several days after receiving a bone marrow transplant from his identical twin for treatment of non-Hodgkin's lymphoma, a 47-year-old man developed a skin rash and diarrhea. RESULTS: A colonic biopsy on day +15 revealed characteristic changes of acute intestinal GVHD. Molecular studies (microsatellite DNA and HLA sequence-specific primer polymerase chain reaction analyses) confirmed the genotypic identity of donor and host and the improbability of transfusion-associated GVHD. CONCLUSION: This case illustrates that pathological evidence of GVHD does not absolutely require the presence of genetic differences between host and donor and questions existing concepts about the nature of cyclosporine-induced GVHD.

Acute Disease↗
PubMed1998

Human hematopoietic progenitor in bone marrow and peripheral blood.

The ability to enhance the frequency of progenitors in the peripheral circulation has resulted in peripheral blood progenitor cell collections being the preferred procurement method for autologous transplants and an accepted alternative for allografts. In autografts, peripheral blood-derived progenitor cells appear to have an advantage over conventional marrow transplants in the form of earlier engraftment without compromising sustained marrow function. Studies were performed to evaluate the broad class of CD34+ progenitors and their subtypes in preparations of bone marrow and peripheral blood cells. As a result, peripheral blood appears to contain a larger quantity of more mature progenitors, which is the likely reason for a more rapid return of granulocytes and platelets. However, controveries continue to exist as to whether the measurements derived from these studies can be used to predict time to engraftment and subsequent reestablishment of a marrow reserve. Some of these issues have been addressed in pilot studies where allografts using G-CSF-mobilized peripheral blood progenitor cells were compared to conventionally harvested bone marrow and bone marrow obtained from G-CSF-stimulated donors. The time to engraftment of neutrophils and platelets were shortened when G-CSF-mobilized peripheral blood or marrow progenitor cells were used compared to case-matched grafts of steady-state marrow. The significance of the suggested differences between steady-state bone marrow grafts and mobilized peripheral blood cells remains to be determined. However, preparations of cytokine-mobilized peripheral blood progenitor cell preparations are being used with increasing frequency to replace conventional marrow harvests.

Antigens, CD34↗
PubMed1998

Clinical and economic analysis of allogeneic peripheral blood progenitor cell transplants: a Canadian perspective.

Allogeneic peripheral blood progenitor cell (PBPC) transplants are an alternative to BMT, although G-CSF mobilization dose, timing of pheresis and risk of GVHD are not well defined. We compared harvest characteristics, donor and recipient outcomes and costs of two PBPC transplant strategies with historical controls who received BMT. Twenty donors mobilized with four daily s.c. G-CSF doses (5 microg/kg/day) (group 1) and 20 mobilized with 10 microg/kg/day G-CSF (group 2) were compared with 20 BM controls (group 3). G-CSF and phereses were well tolerated. Four of 40 PBPC donors required femoral catheter placement. At least 2.5 x 10(6) CD34+/kg recipient weight were collected with two phereses in 19/20 donors (group 1) and 18/20 donors (group 2). Time to neutrophil (18 vs 20 vs 22 days, P = 0.02) and platelet (21 vs 24 vs 27 days, P = 0.005) engraftment was shorter in the PBPC groups (group 2 vs group 1 vs group 3) but secondary engraftment outcomes were not different. The incidence of grade 2-4 aGVHD was higher in the low-dose G-CSF group (group 1) but there was no difference in cGVHD, 100-day or 1-year survival. The mean PBPC transplant cost (group 1) at first hospital discharge was less than BM (group 3) ($34,643 vs $37,354) but the mean overall cost for both groups was similar at 100 days ($46,334 vs $46,083). Allogeneic PBPC transplant with short course, low-dose G-CSF mobilization is safe, feasible and cost equivalent to allogeneic BMT.

Bone Marrow Transplantation↗
PubMed1997

Quality of life following bone marrow transplantation: a comparison of patient reports with population norms.

All surviving patients who had received an allogeneic bone marrow transplant at the Princess Margaret Hospital were asked to participate in a health-related quality of life (HQL) study using the Medical Outcomes Survey-Short Form 36 (MOS SF-36), the Satisfaction with Life Domains Scale-Bone Marrow Transplantation (SLDS-BMT) and a current symptoms checklist. The main objective was to compare the health status of BMT survivors with age-adjusted population norms. Of the 251 patients contacted, 93% returned questionnaires. The median follow-up after BMT was 40 months, ranging from 1-253 months. On average, survivors had some diminished HQL relative to the health status of the population in general. Time since transplant had a significant influence on HQL; those less than 3 years from transplant experienced considerable impairment while those who had survived beyond this point were indistinguishable from the normal population in most domains and significantly better in certain psychosocial aspects of health. Many patients still reported symptoms months after BMT; some were mildly affected while others experienced more troublesome symptoms. However, 81% of patients were satisfied with the HQL outcome that they had achieved and 94% would recommend a transplant for someone in similar circumstances.

Adult↗
PubMed1996

Intensive remission induction therapy for chronic myeloid leukemia in blast phase with a goal of post-remission bone marrow transplant--a pilot study.

An intensive protocol utilizing mitoxantrone, high-dose cytarabine, vincristine, etoposide and methylprednisolone as induction therapy for chronic myeloid leukemia in blast transformation is described. Fourteen patients were treated, with a remission/second chronic phase achieved in 64%. None of the 3 patients older than 50 yr responded. Complete hematological responses were seen in 9 of the 11 younger patients, 4 of whom also became BCR-ABL negative by Southern Blot analysis. Four patients went on to allogeneic bone marrow transplant. Median remission durations were 4.5 (1-5) and 8.5 (5-16) months in the non-transplanted and transplanted cohorts, respectively. Median survival is 1.5 (0.5-3), 9.5 (7-14) and 17 (14-61+) months in the non-responding, responding non-transplanted and transplanted cohorts, respectively. Toxicity, particularly gastrointestinal, was significant. This represents an aggressive protocol that should be reserved for patients who are potential transplant candidates.

Adolescent↗
PubMed1995

Assessment and characterization of hemopoietic stem cells.

The adequate production of blood cells is sustained by pluripotent hemopoietic progenitors whose behavior is influenced by a permissive hemopoietic microenvironment. Hemopoietic progenitors have in common the expression of CD34 surface molecules, but are heterogeneous with respect to other properties. It is commonly accepted that primitive progenitors, considered to be candidates for marrow repopulating cells, are HLA-DR-, without expressing lineage-specific determinants. They are usually quiescent with respect to their cell cycle status. In addition to CD34, they may display adhesion molecules on their surface and express receptors for ligands such as c-kit, FLT2/FLK3 and various other cytokines. Some of these are expressed constitutively, while others emerge as the cells progress through their regular maturation program. This process appears to include a gradual reduction of their proliferative capabilities as demonstrated by a progressive loss of the length of their telomeric structures.

Hematopoietic Stem Cells↗
PubMed1995

p53 mutations, c-myc and bcl-2 rearrangements in human non-Hodgkin's lymphoma cell lines.

Fourteen Non-Hodgkin's lymphoma cell lines were generated and assessed for the presence of structural p53, c-myc and bcl-2 gene changes. Single or multiple changes were observed in 11 of the lines. Alterations of the p53 gene were most frequent and documented for 10 lines by immunoprecipitation using the antibodies PAb 240 and PAb 1801, sequencing studies and Southern blot analysis. A detailed study was performed in one of the cell lines (OCI-Ly 4) for which material of the original tumor sample was available. Two point mutations identified by sequencing cDNA derived from the cell line were also present in the original tumor specimen. In contrast, DNA prepared from fibroblasts of the same patient did not show the mutations. Six of the 14 lines demonstrated c-myc rearrangements, while bcl-2 changes were observed in 4. The presence of c-myc was associated with shorter survival of this group of patients with aggressive disease. None of the other changes present as single or composite alterations were correlated with clinical outcome measures.

Adult↗
PubMed1994

Radiosensitivity of human clonogenic myeloma cells and normal bone marrow precursors: effect of different dose rates and fractionation.

PURPOSE: Evaluation of radiation dose rate and fractionation effects on clonogenic myeloma cells. METHODS AND MATERIALS: The radiosensitivity of clonogenic myeloma cells was evaluated for seven human myeloma cell lines. The lines were maintained in liquid suspension culture. Following radiation, cells were plated in semisolid medium using methylcellulose as viscous support. Radiation doses up to 12 Gy were delivered at dose rates of 0.05 and 0.5 Gy/min by a 60Co source. Each total dose was administered either as a single dose or in multiple fractions of 2 Gy. The data were analyzed according to the linear quadratic and multi target model of irradiation. RESULTS: Clonogenic progenitors of the seven myeloma cell lines differed in their radiosensitivity as measured by multiple parameters. The differences were mainly observed at low dose. The most effective cytoreduction was seen when radiation was administered in a single fraction at high dose rate. The cytoreductive effect on clonogenic myeloma cells was compared for clinically practiced total body irradiation (TBI) schedules delivered either in a single or in multiple fractions without causing significant pulmonary toxicity. The administration of 12 Gy delivered in six fractions of 2 Gy resulted in a superior reduction of clonogenic cells compared to a single fraction of 5 Gy. CONCLUSION: The preparation of bone marrow transplant recipients with multiple myeloma using fractionated radiation with a total dose of 12 Gy appears to afford better ablation than a single dose of 5 Gy while maintaining a low incidence of pulmonary toxicity.

Bone Marrow↗