Search PubMed⌕ Search

Biomedical subjects

N G Testa

Publications and source records attributed to N G Testa.

At least 73 records · Page 4Linked to original sources
PubMed1994

Dose-escalating induction chemotherapy supported by lenograstim preceding high-dose consolidation chemotherapy for advanced breast cancer. Selection of the most acceptable regimen to induce maximal tumor response and investigation of the optimal time to collect peripheral blood progenitor cells for haematological rescue after high-dose consolidation chemotherapy.

BACKGROUND: In advanced breast cancer high-dose consolidation chemotherapy with haematological rescue has resulted in prolonged disease free and overall survival in a small percentage of patients. Maximal reduction of the tumor burden by intensive induction treatment preceding the high-dose chemotherapy may favor that outcome. The aims of this study were to find a rapid highly effective induction regimen with acceptable toxicity and to examine the optimal time for peripheral blood progenitor cell (PBPC) collection for haematological rescue. SUBJECTS AND METHODS: Twenty-four patients received 4 cycles of FAC chemotherapy (5-FU, adriamycin, cyclosphamide), each followed by 10 micrograms/kg/d of lenograstim (glycosylated rHuG-CSF) s.c. day 2 to 11. Chemotherapy was administered at 4 dose intensity levels with 6 patients including at each level (level 1: 500(F)/50(A)/500(C) mg/m2/3wk, level 2: 500/50/500 mg/m2/2wk, level 3: 500/75/500 mg/m2/2wk, m2/2wk, level 4: 500/75/1000 mg/m2/2wk d1 i.v.). In addition lenograstim (10 micrograms/kg/d s.c.) was administered for a period of 10 days before (period X) and after (period Y) chemotherapy. In 16 patients (4 at each dose intensity level) assessment of PBPC was performed during period X and Y as well as during cycle 1 and 4. A single apheresis to collect PBPC was planned during chemotherapy cycle 1. RESULTS: The best response was obtained at dose intensity level 3 (all 6 patients responded, 3 of them achieved CR) with acceptable toxicity. Peak circulating numbers of total CFC/ml blood were median 5819 (period X), 4635 (cycle 1), 3807 (cycle 4) and 3519 (period Y) and occurred concurrently with peak circulating numbers of CD34+ cells. The and median 3.76 x 10(6)/kg CD34+ cells. Three patients received high-dose consolidation chemotherapy with PBPC support. Recovery of ANC > 0.5 x 10(9)/l occurred on median day 11 and of platelets > 20 x 10(9)/l on median day 10. CONCLUSION: Dose intensity level 3 is the best usable induction regimen in this study. The optimal time for apheresis is either during lenograstim before chemotherapy treatment or during the first cycle of chemotherapy. Rapid haematological recovery was obtained by reinfusion of PBPC as sole source of support in the patients receiving high-dose consolidation chemotherapy.

Adult↗
PubMed1994

Viability of haemopoietic progenitors from whole blood, bone marrow and leukapheresis product: effects of storage media, temperature and time.

High-dose cytotoxic chemotherapy can be supported with autologous haemopoietic cells. Cryopreserved bone marrow has conventionally been used for this but blood stem cells are now in common use. We have examined different storage conditions for haemopoietic cells from bone marrow, leukapheresis product and whole blood primed with chemotherapy and filgrastim. The mean number of GM-CFC surviving cryopreservation was 80% in leukapheresis product (95% CI 66-96). At 4 degrees C, GM-CFC viability in all three sources of haemopoietic progenitors declined at the same rate, with mean recovery at 24 h of 90% (95% CI 82-98), at 48 h of 68% (95% CI 61-75) and at 72 h of 47% (95% CI 40-53). Progenitors remained viable for longer in autologous serum and citrate phosphate dextrose or Iscove's medium than in phosphate buffered saline. There was no significant difference in GM-CFC recovery from whole blood or whole blood buffy layer at 4 degrees C. The capacity to generate and sustain haemopoiesis in long-term culture is a feature of the more primitive progenitor cells. This capacity was similar in cryopreserved bone marrow and leukapheresis product, cryopreserved or stored for up to 5 days at 4 degrees C, suggesting that long-term culture-initiating cells are more resilient than colony-forming cells when cryopreserved or stored at 4 degrees C. These data indicate that primed whole blood, in addition to leukapheresis product and bone marrow, could be stored at 4 degrees C and used to support multicyclic high-dose chemotherapy.

Blood Cells↗
PubMed1994

Effects of erythropoietin on mobilisation of haemopoietic progenitor cells.

Peripheral blood progenitor cell (PBPC) mobilising regimens that do not include cytotoxic drugs are needed if PBPC are to be used for allogeneic transplantation. We have studied the effects of erythropoietin on bone marrow and circulating haemopoietic progenitors. Eleven patients with untreated lymphoma received epoetin-alpha 300 or 450 iu/kg subcutaneously (sc) thrice weekly for 2 weeks. Their bone marrows and peripheral bloods were normal at entry. There were no differences between dose levels. Peripheral blood colony-forming cell (CFC) numbers increased fivefold over baseline (p = 0.003) including a sevenfold increase in GM-CFC (p = 0.003). CD34-positive cell numbers increased 4.6-fold (P < 0.01). Maximal CFC release was seen at days 5-8. No consistent change in megakaryocyte numbers was seen. The increase in numbers of cells capable of long-term haemopoiesis was not significant. The ratio of myeloid:erythroid cells in bone marrow reduced from 2.7 to 0.86 after erythropoietin treatment (p = 0.047). In bone marrow the only significant rise in CFCs was in erythroid progenitors. Erythropoietin alone resulted in a modest increase in PBPC that is unlikely to be useful for transplantation. The effects of erythropoietin in combination with other cytokines or with cytotoxic drugs remain to be explored.

Adult↗
PubMed1993

Peripheral blood progenitor cell transplantation in lymphoma and leukemia using a single apheresis.

Myeloablative treatment and peripheral blood progenitor cell (PBPC) transplantation are increasingly used for lymphomas and leukemias. We have sought to optimize conditions for priming, collection, and engraftment of the leukapheresis product. Fifty-four consecutive adult patients were eligible, 31 with high-grade non-Hodgkin's lymphoma of poor prognosis, 12 with Hodgkin's disease in chemosensitive relapse, and 11 with poor prognosis acute lymphoblastic leukemia. Filgrastim was administered after routine chemotherapy with VAPEC-B or HiCCOM to mobilize PBPC. A rapidly increasing white blood cell count was used to predict the time of peak PBPC release and plan leukapheresis. Forty-five patients underwent leukapheresis. A median of 14 L of blood was processed at a single apheresis. A median of 2.4 x 10(8)/kg mononuclear cells (MNCs), 1.04 x 10(6)/kg granulocyte-macrophage colony-forming cells (GM-CFCs), and 10.6 x 10(6)/kg CD34+ cells were obtained. Slightly fewer MNCs were obtained from the heavily pretreated Hodgkin's disease group. There were no other significant differences in the size or composition of the leukapheresis harvest in the three patient groups. Forty patients underwent high-dose therapy and PBPC transplantation. Filgrastim was administered by daily subcutaneous injection until the absolute neutrophil count was > or = 1 x 10(9)/L for 2 consecutive days. Rapid and sustained hematopoietic engraftment occurred in all patients. The median time to achieve a neutrophil count > or = 0.5 x 10(9)/L was 9 days (range, 8 to 16 days); to achieve a platelet count > or = 20 x 10(9)/L was 10 days (range, 6 to 88 days); and to achieve a platelet count > or = 50 x 10(9)/L was 15.5 days (range, 10 to 100 days). Neutrophil recovery was faster than that of a historical control group treated with autologous bone marrow transplantation and filgrastim, but platelet recovery times were halved in the PBPC group. There was no secondary engraftment failure. Requirements for blood and platelet transfusions, antibiotic use, and parenteral nutrition were similar in the three patient groups. The median number of days in the hospital was 13 (range, 10 to 55) in the PBPC patients, compared with 19 (range, 14 to 51) in the historical controls. Leukapheresis yields (MNC, GM-CFC, and CD34+ cell numbers) were not useful for predicting the times to engraftment. We have shown that sufficient PBPC for transplantation can be obtained at a single leukapheresis after mobilization with routine chemotherapy and filgrastim in patients with non-Hodgkin's lymphoma, Hodgkin's disease, and acute lymphoblastic leukemia, even those heavily pretreated.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1993

Transplantation potential of hematopoietic cells released into the circulation during routine chemotherapy for non-Hodgkin's lymphoma.

Primitive hematopoietic cells released into the peripheral blood (PB) were studied in 50 patients with high-grade non-Hodgkin's lymphoma enrolled in a phase III trial of intensive weekly chemotherapy (VAPEC-B) alone or with granulocyte colony-stimulating factor (G-CSF). Mononuclear cells numbers were monitored and their in vitro growth potential assessed in clonogenic progenitor cell assays and in long-term culture. Total colony-forming cells (granulocyte-macrophage [GM], burst-forming unit, erythroid [BFU-E], Mix-CFC) were increased 40-fold (median) over baseline with chemotherapy alone and 106-fold with chemotherapy and G-CSF after the final dose. CD34+ cells were increased to a median of 4%, equivalent to that in normal bone marrow (BM) controls. Circulating colony-forming cell levels were maximal when the recovering total white blood cell (WBC) count reached 5 to 10 x 10(9)/L. The timing of the maximum was reproducible in individual patients. Therefore the WBC count can be used as a guide to the timing of leukapheresis. PB cells from normal controls' and patients' prechemotherapy were unable to sustain hemopoiesis in two-stage long-term cultures. In contrast, PB cells collected from patients primed with chemotherapy alone or chemotherapy with G-CSF at the time of predicted maximal colony-forming cell release were able to generate and sustain hematopoiesis in long-term cultures at a level comparable or superior to normal BM. These findings indicate that the use of G-CSF after routine outpatient chemotherapy stimulates maximal release of primitive hemopoietic cells into the circulation, including colony-forming cells and long-term culture-initiating cells. Their numbers are comparable with those in normal BM and are such that a single leukapheresis will usually yield enough cells for hemopoietic reconstitution after myeloablative chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Residual Ph- cells in chronic myeloid leukemia: detection and usefulness.

Bone marrow cells from patients with chronic myeloid leukemia (CML) in in vitro long-term bone marrow culture (LTBMC) show an impaired survival of Philadelphia (Ph) positive cells and, in a proportion of patients, the emergence of Philadelphia negative hemopoiesis. The standard conditions of in vitro cultures provide optimal purging effect. Selected patients can now have autologous bone marrow transplants (ABMT) with in vitro purged cells.

Bone Marrow Transplantation↗
PubMed1992

Growth of human umbilical-cord blood in longterm haemopoietic cultures.

Cryopreserved human umbilical-cord (HUC) blood is an alternative to bone marrow as a source of haemopoietic "stem" cells for HLA-identical transplantation of children with leukaemia or Fanconi's anaemia. We have studied the in-vitro growth potential of HUC blood in clonogenic assays and in longterm haemopoietic cultures. Clonogenic assays showed that HUC blood produced as many haemopoietic-cell colonies as normal adult bone marrow and a higher proportion of primitive-cell colonies. In longterm culture on preformed irradiated marrow stroma, both progenitor-cell production and lifespan of cultures were significantly greater in HUC blood than in normal bone marrow (p = 0.0007). Our findings indicate that the quality and quantity of HUC-blood-derived haemopoietic "stem" cells are better than those of normal bone marrow. Therefore, single HUC-blood donations are probably sufficient for adults requiring transplantation for leukaemia and other haemopoietic disorders. Banking of HLA-typed HUC blood to facilitate transplantation of patients who lack a family donor should be considered.

Blood Transfusion↗
PubMed1992

"Stem cell" origin of the hematopoietic defect in dyskeratosis congenita.

We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse.

Adolescent↗
PubMed1992

Effect of enkephalins on bone marrow cells.

Mouse bone marrow cells were incubated with methionine- or leucine-enkephalin (10(-15)-10(-6) M) before seeding into soft agar cultures. In marrow samples harvested at different times, enkephalins decreased GM colony count on average by 30-40%. In individual experiments, however, the same concentration of enkephalins caused even stimulation, or at other times had effect. In view of the circadian periodicity of neuroendocrine functions and hematopoietic activity, the enkephalin effect on bone marrow cells was tested on marrow samples harvested at fixed time points (6 am, 6 pm), using enkephalin concentrations in the physiological range (10(-12)-10(-9) M). The seeding efficiency of the 6-pm cell population was on average 50% above that of the 6-am population. The 6-pm cell population was also more susceptible to the inhibitory effect of the enkephalins (35% inhibition) than the 6-am population (15% inhibition), and the variability in response was considerably reduced. With progenitor cell-enriched population, obtained by fluorescence-activated cell sorting (FACS) of 6-am bone marrow samples, in 3 out of 6 experiments Met- and Leu-enkephalin showed 30-35% inhibition of GM colony formation over a wide range of concentrations (10(-15)-10(-6)). In the other 3 experiments, suppression as well as stimulation or no alteration in colony count were observed. This variability probably reflected quality (purity) of the progenitor cell population, and may indicate that the enkephalins affected hematopoietic cells via a population of accessory cells.

Analysis of Variance↗
PubMed1992

Colony-stimulating factors in the clinic.

Recombinant purified human haemopoietic growth factors are available for clinical trials and some have been licensed for therapeutic use. Some haemopoietic lineages (erythroid, neutrophilic, monocyte-macrophagic) can be selectively stimulated in order to ameliorate the cytopenias that follow cytotoxic treatment, or that characterize some haematological syndromes, and to stimulate mature cell function. Advances in the knowledge of receptor-ligand interactions and of transduction mechanisms, plus the production of synthetic or mutant molecules that may mimic, potentiate or antagonize the effects of the natural growth factors, should make novel therapeutic approaches possible.

Animals↗
PubMed1992

The capacity of peripheral blood stem cells mobilised with chemotherapy plus G-CSF to repopulate irradiated marrow stroma in vitro is similar to that of bone marrow.

After treatment of patients with intermediate or high grade non-Hodgkin lymphoma with chemotherapy plus G-CSF the numbers of haemopoietic progenitor cells in the circulation increased to a mean of 226-fold for mixed CFC (Mix-CFC), 278-fold for GM-CFC and 29-fold for erythroid burst forming unit (BFU-E). The mean increase was modest (7-12-fold) for patients treated with chemotherapy alone. Peripheral blood mononuclear cells harvested at the time of the peak in the numbers of progenitors, or 2-4 days before the peak, seeded onto irradiated marrow stroma in vitro, repopulated the stroma and generated active haemopoiesis at least as effectively as bone marrow cells on a cell per cell basis. This is in contrast to the poor repopulating capacity of pretreatment blood. The results indicate that not only the progenitor cells, but also the repopulating stem cells migrated into the blood after chemotherapy plus G-CSF in sufficient numbers to allow harvesting and successful grafting without the possible complication of late haemopoietic failure.

Adult↗
PubMed1992

Human cord blood: a source of transplantable stem cells?

In a preliminary study we have shown that optimally collected human umbilical cord (HUC) blood cells grow significantly better in long term cultures (LTC) than normal adult marrow cells (NBM) p = 0.0007. The LTC findings are supported by the observation in clonogenic assay that a similar number of GM-CFC colonies can be grown from HUC blood and NBM mononuclear cells (MNC). Also there is a trend towards a higher proportion of primitive erythroid (BFU-E) and primitive megakaryocyte colonies (MK-CFC containing greater than 20 cells) in HUC blood compared with NBM. We suggest that further work on the feasibility of a HLA typed, cryopreserved HUC blood bank as a source of unrelated haemopoietic 'stem' cells for clinical transplantation is indicated.

Blood Cell Count↗
PubMed1991

Interactions in recovery and in residual injury from sequential treatments of mouse haemopoietic and stromal marrow cell populations, using X-rays, cyclophosphamide and busulphan.

The acute recovery of populations of day 11 CFU-S, iv-CFC and CFU-F in mouse bone marrow, following a test dose of X-rays, cyclophosphamide (CP) or busulphan (BUS) given to mice previously treated with repeated priming doses of X-rays or CP, was in general predictable from the amount of residual injury after the priming doses. A marked exception was iv-CFC after X-rays, which although amplified to near normal levels during the residual injury phase, recovered after the test irradiation from low levels of CFU-S. The amount of residual injury after sequential treatments of different agents was in general less than expected on the basis of the product of the effects of the individual agents. This was most marked for CP priming treatments, where the long-term recovery of day 11 CFU-S after the test dose remained persistently above control levels. Also, some correlation was found between improved stromal recovery (CFU-F) and the CFU-S content following the sequential treatment protocols.

Animals↗
PubMed1991

The biology of long-term bone marrow cultures and its application to bone marrow transplantation.

Long-term bone marrow cultures have been applied to the study and to the treatment of hemopoietic disease. The incidence of murine primitive (stem) cells with the ability to repopulate irradiated bone morrow stroma is similar to that of cells able to repopulate the hemopoietic system of potentially lethally irradiated mice. In human bone marrow, cells with in vitro repopulating ability have been estimated as 0.5% to 1% of the CD34+ cells. The increase in primitive cells in the circulation seen after administration of growth factors has been exploited by harvesting those cells for use together with bone marrow in autologous transplants. The ability of primitive cells (harvested after granulocyte colony-stimulating factor plus chemotherapy) to reconstitute irradiated marrow stromas indicates that their repopulation capacity in vitro is at least as good as that of bone marrow. This is confirmed by experimental data in mice showing that small volumes of peripheral blood (after granulocyte colony-stimulating factor administration) are capable of long-term repopulation. The regulator capacity of marrow stroma has been exploited to purge bone marrow cultures from patients with acute myeloblastic leukemia in first remission and from treated patients with chronic myelogenous leukemia before using the cultured cells for autologous transplant. The results to date, although preliminary, indicate a role for this methodology in the treatment of leukemia.

Animals↗
PubMed1991

In vitro assessment of marrow 'stem cell' and stromal cell function in aplastic anaemia.

An in vitro model system is described that allows separate assessment of 'stem cell' and stromal cell function in aplastic anaemia (AA). Seven patients with non-severe AA, who had responded to immunosuppressive therapy and had haematological evidence of residual marrow function, were studied. Of these, three with otherwise typical AA had an acquired clonal cytogenetic marker. Purified bone marrow haemopoietic progenitors labelled with CD34 monoclonal antibody were positively selected using the fluorescence activated cell sorter (FACS) from both normal subjects and from patients with AA. The generative capacity of the CD34 positive cells was assessed by monitoring the output of granulocyte/macrophage colony forming cells (CFU-GM) in the non-adherent layer after inoculation onto irradiated performed long-term marrow culture (LTBMC) stromas. Stromal function in AA was assessed by inoculating CD34 positive cells from normal bone marrow onto performed irradiated stromas from patients with AA. Haemopoietic cell ('stem cell') function in AA was assessed by inoculating CD34 positive cells from AA patients onto confluent irradiated normal marrow stromas. Using these crossover/LTBMC experiments, all patients exhibited severe defects in haemopoietic cell function with normal functioning stroma. The proportion of CD34 positive cells present in bone marrow from these patients was reduced compared with controls, they comprised fewer small primitive 'blast-like' cells which in normal bone marrow are known to possess marrow repopulating ability, and demonstrated reduced clonogenic potential in short-term colony assays.

Adult↗