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Biomedical subjects

B C Millar

Publications and source records attributed to B C Millar.

At least 91 records · Page 5Linked to original sources
PubMed1996

Lymphocyte recovery and clinical response in multiple myeloma patients receiving interferon alpha 2 beta after intensive therapy.

The recovery of immunoregulatory cells in the peripheral blood of patients with multiple myeloma receiving maintenance therapy with interferon alpha 2 beta (IFN-alpha 2 beta) after intensive therapy with high-dose melphalan and autologous bone marrow or peripheral blood stem cell rescue was studied. IFN-alpha 2 beta significantly inhibited the recovery of CD3+, CD4+, CD8+, CD56+/CD3- and CD16+/CD3- lymphocytes compared with numbers found in patients who had no further post-transplant treatment, but had no effect on the recovery of CD19+ cells. Among patients who did not receive IFN-alpha 2 beta, the number of CD8+, CD56+/CD3- and CD16+CD3- lymphocytes recovered to values similar to normal volunteers with increasing time after intensive therapy, however the number of CD4+ cells remained significantly below levels found in normal volunteers. Although CD16+/CD3- and CD56+/CD3- cell numbers were reduced in patients receiving IFN-alpha 2 beta, natural killer (NK) activity was not affected. The levels of soluble interleukin 2 receptor (sIL-2R) were similar in all patients and IL-2 was not detected in any patient. At the time of writing, of the total of 69 patients, seven have relapsed, of whom three were receiving IFN-alpha 2 beta, however there was no correlation between the absolute numbers of any lymphocyte subset with imminent relapse. The data suggest that the recovery of a specific lymphocyte subset(s) in peripheral blood is unlikely to be associated with the maintenance of response after intensive therapy.

Antineoplastic Agents, Alkylating↗
PubMed1996

Role of CD34+ cells in engraftment after high-dose melphalan in multiple myeloma patients given peripheral blood stem cell rescue.

During the period December 1992 to June 1995, 95 patients were treated with high-dose melphalan (HDM) with peripheral blood stem cell rescue (PBSCR). Sixty-five had received previous treatment and 28 had relapsed. Among patients who had relapsed 21/28 had received HDM previously including one who received HDM twice during the course of the study. Seventy-five patients were given HDM/PBSCR for the first time. Comparisons have been made between engraftment times for platelets and neutrophils among patients who received less than or greater than 2 x 10(6) CD34+ cells at rescue. Analyses have also been done to evaluate the effect of previous HDM on recovery. Mobilization of progenitor cells was done with granulocyte colony-stimulating factor (G-CSF). Patients received only PBSCR. No growth factors were given to the PBSCR recipients during the recovery period. The percentage of patients from whom the number of CD34+ cells mobilized was > 2 x 10(6)/kg was similar in patients who received HDM for the first time (23%) compared with those who had had it previously (19%). The yield of CD34+ cells correlated with the number of granulocyte-macrophage colony forming units (CFU-GM). Although the number of CD34+ cells infused was < 2 x 10(6)/kg in 77% of patients, all engrafted for neutrophils to > 0.5 x 10(9)/l. This was delayed in patients who had had previous HDM (P < 0.02). Platelet recovery to > 25, 50 and 100 x 10(9)/l was delayed in all patients who received < 2 x 10(6) CD34+ cells/kg infused (P < 0.02). In patients who had had previous HDM both neutrophil (P < 0.05) and platelet recovery (P < 0.007) were delayed compared with recovery in patients who had not had HDM. In patients who had had previous HDM and received < 2 x 10(6) CD34+ cells/kg infused only 3/17 regained platelets to > 100 x 10(9)/l compared with 3/4 who had > 2 x 10(6) CD34+ cells/kg infused (P < 0.05 Fisher's exact test). There was no evidence that low numbers of CD34+ cells in the PBSCR were associated with early death. The data show that previous treatment with HDM had adverse effects on the subsequent engraftment of platelets among patients given HDM/PBSCR. The data suggest that additional measures are needed to achieve platelet reconstitution in these heavily pre-treated patients.

Antigens, CD34↗
PubMed1995

The proliferation of multiple myeloma colonies (MY-CFUc) in vitro is independent of prognosis and is not associated with mutated N- or K-ras alleles in human bone marrow aspirates.

During the period September 1987 to March 1993 the proliferation of myeloma cells as colonies (MY-CFUc) in vitro was examined in bone marrow aspirates from 43 patients with multiple myeloma and two patients with Waldenström's macroglobulinaemia. Twenty-four samples from 45 patients, of whom three were at presentation, four were in complete remission (CR), six had achieved a partial response (PR) and 11 had progressive disease (PD), produced MY-CFUc in vitro. The same bone marrow aspirates or one taken within 2 months of that assessed for MY-CFUc were used in the polymerase chain reaction (PCR). Genomic DNA was analysed for mutations in N- and K-ras by slot blotting of the amplified products from the PCR with 32P-labelled probes and by direct sequencing. No mutations were detected in N- or K-ras proto-oncogenes at codons 12, 13 or 61 in any sample. Eleven of the patients from whom MY-CFUc were produced remain alive with a median survival of 73 months (range 15-75 months). MY-CFUc have been cultured from 19 of these 24 patients on subsequent occasions, of whom nine remain alive. Among patients whose cells did not produce MY-CFUc in vitro at the time of sampling for mutated ras alleles, biopsy samples from four patients have produced MY-CFUc in vitro on subsequent occasions, of whom one patient remains alive. The data show that the proliferation of MY-CFUc in vitro occurred independently of disease status and was not indicative of prognosis. The failure to detect mutated N- or K-ras alleles in any sample suggests that if such mutations were present in the cells which form colonies in vitro they represented less than 0.1% of the tumour burden and did not affect the survival of this group of patients.

Alleles↗
PubMed1995

2',5'-Oligoadenylate synthetase levels in patients with multiple myeloma receiving maintenance therapy with interferon alpha 2b do not correlate with clinical response.

In clinical trials with interferon alpha 2b (IFN-alpha 2b) as maintenance therapy for multiple myeloma, the therapeutic benefit is inconclusive. Although the mechanism(s) by which IFN-alpha 2b prolongs remission in some patients is unknown, 2',5'-oligoadenylate synthetase (2,5-A synthetase) has been used as an objective indicator that IFN-alpha 2b is active in vivo. The enzyme was assayed in cytosol preparations of peripheral blood mononuclear cells (MNCs) from 111 patients who were receiving IFN-alpha 2b and 54 patients who were not, using an assay which measures the conversion of [alpha-32P]ATP to triphospho(adenylyl 2',5')adenosine. 2,5-A synthetase activity was compared with response to intensive therapy and with duration of maintenance therapy. Seventy-three per cent of patients had measurable amounts of 2,5-A synthetase during the first 6 months of maintenance therapy. This percentage decreased with longer follow-up but not significantly. There was no difference between the magnitude of enzyme induction amongst patients who were in complete remission, partial response or who had no change in disease status following intensive therapy. Peripheral blood T cells were a major source of 2,5-A synthetase activity in patients receiving the cytokine. However, both T and B cells produced the enzyme following exposure to IFN-alpha in vitro. The data show that the level of 2,5-A synthetase in patients with multiple myeloma is not indicative of clinical response to IFN-alpha 2b.

2',5'-Oligoadenylate Synthetase↗
PubMed1995

Regulation of protein synthesis and degradation in adult ventricular cardiomyocytes.

For studies on the regulation of myocardial protein metabolism, isolated adult cardiomyocytes were introduced as an experimental model about a decade ago. When used shortly after isolation, this model represents a tool for studying the properties of normal and diseased myocardium on the cellular level. The influence of various peptide hormones, neurotransmitters, and mechanical stimulation on protein synthesis and degradation in isolated cardiomyocytes has been studied. It has been demonstrated, for example, that alpha 1-adrenoceptor stimulation increases protein synthesis in newly isolated cardiomyocytes, independently of any mechanical effects. Other potential growth stimuli require appropriate conditions to induce cellular responsiveness. Neuropeptide Y, for example, does not stimulate cellular protein synthesis in newly isolated cells, whereas it does so in cells that have been cultured for a week in the presence of serum. Mechanical stretch also represents a growth stimulant. It seems that its signal transduction involves an autocrine loop. Thus different mechanisms, by which exogenous influences can modify cellular protein synthesis and degradation, have been identified on the cellular level, with the use of isolated adult cardiomyocytes.

Adrenergic alpha-Agonists↗
PubMed1995

G-CSF is a major component of colony-stimulating activity (CSA) in the plasma of patients with multiple myeloma after treatment with high-dose melphalan (HDM).

Colony-stimulating activity (CSA) was measured by the production of granulocyte-macrophage colony-forming units (GM-CFU) from normal donor bone marrow in the plasma of 29 patients with multiple myeloma (MM) after intensive treatment with high-dose melphalan (HDM) with or without autologous bone marrow rescue (ABMR). Although patients who received ABMR had an earlier recovery of circulating neutrophils compared with those who received HDM alone, the time at which CSA reached a maximum was similar in both groups (10 to 11 days) after therapy. The decline in CSA correlated with the recovery of the neutrophil count. In plasma from patients who received recombinant human granulocyte colony-stimulating factor (rhG-CSF), in addition to an autograft, CSA reached a maximum earlier (7 days). Furthermore, neutrophil recovery was earlier in these patients. Platelet recovery was not increased by rhG-CSF. The time at which CSA was maximum in four patients who were undergoing intensive therapy for the second time occurred 9 days after treatment with HDM. Although the period without neutrophils was longer in three (of four) patients who survived long term, one patient who received rhG-CSF had a shorter period of neutropenia than the two who had not had the cytokine. G-CSF was detected in plasma from seven of seven patients but not at all times after treatment. In plasma samples that contained G-CSF, colony numbers were increased by recombinant interleukin-4 (rIL-4) in vitro. Neither IL-3 nor GM-CSF was detected in plasma; however, antibody to GM-CSF reduced CSA in all samples after intensive therapy. The data suggest that CSA is a consistent physiologic response to intensive therapy, even in previously treated patients, but that hematologic recovery is dependent on the availability of viable progenitor cells.

Bone Marrow Transplantation↗
PubMed1994

Neutralising antibodies in patients with multiple myeloma receiving maintenance therapy with interferon alpha 2b.

In a study of 29 patients who were receiving or had received interferon alpha 2b (IFN-alpha 2b) as maintenance therapy for multiple myeloma, antibodies were detected in 58% (17/29) of patients measured by a solid-phase enzyme-linked immunosorbent assay (ELISA). Only 7/17 patients who were positive for antibody in the ELISA had neutralising antibody to IFN-alpha 2b, measured by virus growth inhibition. These patients comprised six who were receiving IFN-alpha 2b at the time of assessment and one who had finished treatment. Among patients who were receiving the cytokine, four had progressive disease, one was in complete remission and one in partial remission. Neutralising activity was also detected to natural human leucocyte IFN-alpha in the same patients. Two patients who were positive for neutralising antibody remain in remission and are continuing to receive IFN-alpha 2b. These two patients have since lost their neutralising titre. No neutralising antibody to IFN-alpha 2b or natural human leucocyte IFN-alpha was detected in serum from six normal donors. The data suggest that neutralising antibody formation in patients with multiple myeloma is not responsible for relapse in patients receiving IFN-alpha 2b. The transient nature of neutralising antibody production in patients who remain in remission suggests that this response to IFN-alpha 2b is not associated with memory B cells.

Antibodies, Neoplasm↗
PubMed1994

Neuropeptide Y stimulates hypertrophy of adult ventricular cardiomyocytes.

It was investigated whether neuropeptide Y (NPY) could exert a trophic effect on ventricular myocytes isolated from the adult rat heart. Two different culture models were used: day 1 and 7 cultures of cardiomyocytes. In day 1 and 7 cultures, NPY caused an increase in cellular protein mass. In day 1 cultures, NPY (10 nM) increased the protein-to-DNA ratio within 24 h by 10.1 +/- 2.8% (P < 0.01), but did not stimulate the incorporation of [14C]phenylalanine into cell proteins. The degradation of proteins was retarded in presence of NPY, revealed by pulse-chase experiments. In day 7 cultures, NPY (10 nM) increased the protein-to-DNA ratio within 24 h by 33.9 +/- 5.0% (P < 0.01), increased the RNA-to-DNA ratio by 19.2 +/- 6.4%, and stimulated the incorporation of [14C]phenylalanine by 45.5 +/- 4.5% (P < 0.01). As in day 1 cultures, protein degradation was retarded. The specific activities of cytosolic creatine kinase and lactate dehydrogenase were increased in presence of NPY. This study demonstrates for the first time that NPY is a trophic factor for cardiomyocytes. NPY can cause an increase in cellular mass of protein, i.e., hypertrophy, by two mechanisms: 1) reduction of degradation of protein, found in day 1 and 7 cultures, and 2) stimulation of protein synthesis, observed only in day 7 cultures. The responsiveness of protein synthesis to NPY stimulation is induced during prolonged incubation in culture.

Animals↗
PubMed1994

TGF beta 1 and IL-4 have opposing effects on the proliferation of chronic phase chronic myeloid leukaemic cells stimulated by G-CSF in vitro.

The effects of transforming growth factor beta 1 (TGF beta 1) have been studied in vitro on the clonogenicity of haemopoietic progenitor cells (CFU-CML) from 14 patients with chronic myeloid leukaemia (CML) in chronic phase and 13 normal donors. In 14/14 patients with CML, 5 ng of TGF beta 1/dish decreased CFU-CML-formation in cultures stimulated with 15 ng of granulocyte colony-stimulating factor (G-CSF)/dish (p < 0.0005) and in 13/14 patients TGF beta 1 reduced CFU-CML-formation induced by G-CSF in combination with 5 ng of recombinant human interleukin-4 (rhIL-4)/dish (p < 0.005). In 10/14 samples the number of CFU-CML were reduced to levels lower than in cultures containing G-CSF alone (p < 0.01). In contrast, TGF beta 1 had no significant inhibitory effect on the G-CSF-directed proliferation of normal donor mononuclear cells (MNC) either alone or in combination with rhIL-4. RhIL-4 increased G-CSF-induced colony formation in 13/14 CML samples (p < 0.001), but did not have the same effect in the normal donor samples. The in vitro clonogenicity of CML peripheral blood MNC stimulated with 15 ng of G-CSF could not be correlated with the white cell count or the percentage of CD34+ cells at diagnosis.

Antigens, CD↗
PubMed1993

2'-Chlorodeoxyadenosine: evaluation of a novel predominantly lymphocyte selective agent in lymphoid malignancies.

2'-Chlorodeoxyadenosine (2CDA) is a purine analogue selectively active against both resting and dividing lymphoid cells. Twenty-one patients with a variety of previously treated lymphoid malignancies received a total of 41 courses of 2CDA (0.1-0.15 mg/kg/day over 7 days continuous intravenous infusion) on compassionate grounds. The profile of the patient population was as follows: low grade non-Hodgkin's lymphoma (NHL) = 8, intermediate grade NHL = 2, transformed (intermediate grade NHL) = 6, Hodgkin's disease = 1, lymphoplasmacytoid NHL = 3 and lymphoblastic NHL = 1. The overall response rate was 53%, with three patients attaining complete remission (CR) and eight partial remission (PR). Three of 16 patients with primary resistant or resistant recurrent disease entered either CR (1) or PR (2). Ten patients had no response or progressive disease. The latter group was comprised of patients who had extensively pre-treated lymphoplasmacytoid tumours and/or poor performance status (WHO grades 2-4). The median duration of response is 6 months (range 1 to 12 months). Treatment was well tolerated and the chief toxicities were leucopenia and thrombocytopenia which were most pronounced when there was bone marrow involvement. As a result of dose limiting myelotoxicity, a dose escalation to 0.15 mg/kg/day was possible on just three occasions. These data confirm other reports of the activity of 2CDA in low grade NHL and indicate it may have activity in Hodgkin's disease. There was no demonstrable activity in poor performance status patients or those with extensively pre-treated lymphoplasmacytoid tumours.

Adult↗
PubMed1993

The effect of 1,25-dihydroxyvitamin D3 on lymphoma cell lines and expression of vitamin D receptor in lymphoma.

1,25(OH)2D3 promotes differentiation and has an antiproliferative effect in a variety of cell lines derived from the immunohaematopoetic system. alpha-Calcidol which is metabolised to 1,25(OH)2D3 has been shown to produce tumour regression in follicular low grade non-Hodgkin's lymphoma (NHL) and the dose limiting toxicity is hypercalcaemia. The cellular action of 1,25(OH)2D3 is mediated by binding to an intracellular protein, the vitamin D receptor (VDR). We have evaluated the activity of 1,25(OH)2D3 and its non-calcaemogenic analogue MC903 in the SU-DHL4 and SU-DUL5 B cell lines which carry the 14;18 translocation characteristic of follicular NHL, and also the expression of the VDR in a range of B cell NHLs. Both agents induced differentiation and had an antiproliferative effect on the SU-DHL4 and SU-DUL5 cell lines. However this occurred at a relatively high concentration (10(-7) M) which exceeds the physiological concentration of 1,25(OH)2D3 by approximately 10(3)-10(4)-fold. Expression of the VDR was low in each cell line and in the low grade lymphoma tumour samples. To account for the observed clinical response to 1 alpha OHD3 (alpha-calcidol) in follicular NHL a network is suggested whereby 1,25(OH)2D3 modulates the activity of CD4+T cells which have previously been shown to promote follicle centre cell proliferation. Vitamin D3 analogues may enable serum levels to be achieved which produce a direct action on follicular lymphoma cells without disturbing calcium metabolism.

Biopsy↗
PubMed1992

Influence of collection and separation of blood samples on plasma IL-1, IL-6 and TNF-alpha concentrations.

The anticoagulant used for the collection of blood was found to influence in vitro cytokine production in whole blood. Lithium heparin in certain collection tubes was found to contain endotoxin and induced cytokine synthesis in a time-dependent manner whereas endotoxin-free lithium heparin did not. No induction of cytokine occurred in the presence of EDTA which was also able to inhibit endotoxin-induced cytokine synthesis. Synthesis or absence of cytokine correlated with the induction of messenger RNA. Investigation of the kinetics of cytokine induction in whole blood revealed that tumour necrosis factor alpha (TNF) was detectable after 2 h of incubation at 37 degrees C and interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) after 3 h. In certain samples IL-1 and IL-6 were detectable in plasma separated immediately from blood collected into endotoxin-free lithium heparin, presumably reflecting in vivo synthesis, and similar concentrations were detected after 3 h of incubation of whole blood at 37 degrees C. These data indicate that as long as blood is collected into endotoxin-free anticoagulant then cytokine measurements will reflect the in vivo status.

Base Sequence↗
PubMed1992

Colony-stimulating activity in the serum of patients with hemopoietic malignancies after intensive chemotherapy/radiotherapy: its augmentation by GM-CSF in vivo and interleukin 4 in vitro.

Colony-stimulating activity (CSA) in the serum of patients with hematological malignancies increased substantially after intensive therapy with cyclophosphamide/busulfan, cyclophosphamide/total body irradiation, or melphalan/total body irradiation. This was not dependent on patients receiving allogeneic bone marrow transplantation (ABMT) or autologous bone marrow rescue (ABMR). In 44 of 62 patients CSA was maximum approximately 7 days after chemotherapy/radiotherapy, whereas in 18 of 62 patients CSA was maximum between 9 and 20 days after therapy and decreased thereafter. The time course of CSA was not dependent on disease and was not affected by recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) given as a continuous infusion for 14 days after therapy; however, serum from patients receiving rhGM-CSF produced significantly more colonies from donor bone marrow than serum from patients who did not receive the cytokine (p = 0.013). Despite the early peak in CSA in the majority of patients, there was no correlation between the time at which CSA was maximum and the return of patients' neutrophils to 500/microliters. Recombinant human interleukin 4 (IL-4) increased the number of granulocyte-macrophage colony-forming unit colonies, principally granulocyte colony-forming unit colonies, from normal bone marrow exposed to patients' serum after intensive therapy and antibody to GM-CSF reduced colony numbers. The results suggest that after intensive therapy granulocyte colony-stimulating factor (G-CSF) as well as GM-CSF is released into the serum and, in addition to acting directly with G-CSF, IL-4 may stimulate mononuclear cells to produce and/or release G-CSF.

Bone Marrow Cells↗
PubMed1991

Positive and negative contractile effects of neuropeptide Y on ventricular cardiomyocytes.

The potency of neuropeptide Y (NPY) to cause negative and positive contractile responses in rat ventricular cardiomyocytes was investigated. In these cells, NPY was found to activate the transient outward K+ current (Ito) and the slow inward Ca2+ current (Isi). As reported before (H. M. Piper, B. C. Millar, and J. R. McDermott, Naunyn Schmiedeberg's Arch. Pharmacol. 340: 333-337, 1989), NPY attenuated the increase in the contractile response induced by isoprenaline (10(-7) M). This effect of NPY could be abolished by 1) the presence of the inhibitor of Ito, 4-aminopyridine (4-AP, 0.5 mM); 2) pretreatment of the cells with pertussis toxin (1 microgram/ml for 6 h); and 3) the presence of the 19-amino acid COOH-terminal fragment of NPY, NPY-(18-36) (10(-6) M). In the absence of isoprenaline, but in the presence of 4-AP, NPY exerted a stimulatory effect on the cardiomyocytes. This effect could be abolished 1) by using the inhibitor of the Isi, verapamil (10(-8) M), but not 2) by pretreatment with pertussis toxin, nor 3) by coincubation with NPY-(18-36). The results indicate that in the rat the antiadrenergic negative contractile effect of NPY results from its action on the Ito. Blockade of this current by 4-AP unmasks a positive contractile effect of NPY that is related to activation of the Isi.

4-Aminopyridine↗
PubMed1991

Comparison of interleukin-6 levels in the bone marrow of multiple myeloma patients with disease severity and clonogenicity in vitro.

Fifteen of 25 bone marrow aspirates from 23 patients who presented or had been treated for multiple myeloma at the Royal Marsden Hospital produced myeloma colonies (MY-CFUc) in vitro. There was no correlation between disease severity and the level of interleukin-6 (IL-6) in bone marrow plasma nor was there any evidence that the level of IL-6 was higher in bone marrow aspirates from patients whose tumour produced MY-CFUc in vitro compared with those who did not. The mean level of IL-6 in the whole group of patients was 0.41 ng/ml (range 0.1-0.66 ng/ml), a value similar to that found in plasma from normal donor bone marrow, 0.42 ng/ml (range 0.14-0.62 ng/ml). Separation of peripheral blood cells from serum 24 h after collection, compared with 2 h after collection, resulted in a substantial increase of IL-6 in the serum. The results suggest that levels of IL-6 in bone marrow plasma is not a monitor of disease severity in multiple myeloma (MM) and that the collection and separation of blood and/or bone marrow samples into the cellular and aqueous components should be performed using standardized conditions to minimize inter-sample variation resulting from the release of IL-6 from the cellular components.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Enhanced anti-tumour activity of carmustine (BCNU) with tumour necrosis factor in vitro and in vivo.

The effects on experimental melanoma of a combination of recombinant human tumour necrosis factor alpha (rhTNF alpha) and carmustine (BCNU) were studied in vitro and in vivo. In vitro, BCNU alone was cytotoxic to murine B16 melanoma cells, and at all concentrations of BCNU this toxicity was increased by the addition of TNF. In vivo, BCNU and TNF, when given separately, caused tumour growth delay of B16 melanoma and of human melanoma xenografts in immune-deprived mice. The combination of TNF at low dose 2.5 x 10(5) U kg-1 = 122 ng kg-1) with BCNU (35 mg kg-1) resulted in significant growth delay (compared with either drug alone) in B16 melanoma (P = 0.005). There was no significant increase in toxicity as assessed by weight loss and peripheral blood counts. Experiments with human melanoma xenografts yielded similar results (P = 0.001) but only at higher doses of TNF (1 x 10(6) U kg-1 = 489 ng kg-1). The enhancement of BCNU cytotoxicity by TNF may be important if it can be translated into patients with melanoma. A randomised study is now underway to investigate the clinical potential of this observation.

Animals↗