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Biomedical subjects

M J Watts

Publications and source records attributed to M J Watts.

At least 37 records · Page 2Linked to original sources
PubMed1997

Crossover study of the haematological effects and pharmacokinetics of glycosylated and non-glycosylated G-CSF in healthy volunteers.

A cross-over study of glycosylated and non-glycosylated G-CSF was performed in 20 healthy male volunteers to compare the effects of the different forms of G-CSF, the extent of inter-individual progenitor cell mobilization and to determine whether any differences observed were related to the serum concentrations of G-CSF attained. The peak WBC achieved during 6 d of G-CSF administration at a dose of 5 microg/kg/d was significantly higher with the glycosylated than the non-glycosylated product (P = 0.02) as was the peak level of granulocyte-monocyte colony forming cells (GM-CFC) (P=0.03). The average GM-CFC count on days 5, 6 and 7 was 28% higher with the glycosylated product (P=0.003). Serum concentrations of G-CSF achieved were significantly higher with the non-glycosylated G-CSF, however, suggesting that the difference in bio-efficacy was not due to a difference in G-CSF stability. Marked inter-individual variation in progenitor mobilization was observed, but this was not related to serum G-CSF levels. The G-CSF concentrations on day 6 were approximately one third of those on day 1, with both forms of G-CSF.

Adjuvants, Immunologic↗
PubMed1997

Peripheral blood stem cell transplantation.

High dose chemo/radiotherapy requiring autologous haemopoietic stem cell support is increasingly used in a variety of malignant disorders. Mobilised peripheral blood stem cells (PBSC) have largely replaced the use of autologous bone marrow due to more rapid haemopoietic reconstitution with less resource use including blood and platelet transfusion requirements. PBSC graft adequacy is monitored by CD34+ cell and granulocyte-monocyte-colony-forming-cell measurements, and thresholds for rapid engraftment have been determined. Studies are in progress to determine the optimal mobilisation regimens that will permit the achievement of the necessary progenitor thresholds with only one or two aphereses. This will facilitate the use of multiple cycles of high dose therapy and possibly the use of PBSC collected by venesection rather than apheresis. PBSC are also increasingly used in the allogeneic setting where specific mobilisation protocols not using cytotoxic drugs are employed. These technical advances will aid the execution of large trials to determine the efficacy of high dose therapy.

Blood Specimen Collection↗
PubMed1997

The leukotriene receptor antagonist zafirlukast inhibits sulfur dioxide-induced bronchoconstriction in patients with asthma.

Inhalation of sulfur dioxide (SO2) causes bronchoconstriction in most people with asthma. To examine the role of leukotrienes in this response, the antagonism of SO2-induced bronchoconstriction by a single oral dose of the leukotriene receptor antagonist zafirlukast was assessed in a double-blind, placebo-controlled, two-period crossover trial in 12 subjects with mild-to-moderate asthma. Subjects had bronchial hyperresponsiveness, an FEV1 < or = 70% of predicted, and a positive response to inhaled SO2 (an 8-unit increase in specific airway resistance on inhaling an SO2 concentration of < or = 4 ppm (PC8SRaw). Subjects were treated with zafirlukast (20 mg) or placebo on two treatment days 5 to 14 d apart. Two and 10 hours after treatment, subjects inhaled SO2 (0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 ppm) during eucapnic hyperventilation at 20 L/min. PC8SRaw was determined after each challenge. Blood samples were collected to assess zafirlukast plasma concentrations versus effect. PC8SRaw was significantly higher 2 h after zafirlukast compared with placebo (3.1 versus 1.5 ppm; p = 0.02) and remained higher 10 h after treatment with zafirlukast (2.7 versus 1.9 ppm; p = 0.09). An association was found between zafirlukast plasma concentrations and increases in PC8SRaw 10 h after treatment (p = 0.001). The safety profile of zafirlukast was not clinically different from placebo. A single 20-mg dose of zafirlukast attenuated SO2-induced bronchoconstriction. We conclude that S02-induced bronchoconstriction involves release of leukotrienes and that treatment with zafirlukast attenuates the bronchoconstrictor response.

Adult↗
PubMed1997

Progenitor-cell mobilization after low-dose cyclophosphamide and granulocyte colony-stimulating factor: an analysis of progenitor-cell quantity and quality and factors predicting for these parameters in 101 pretreated patients with malignant lymphoma.

PURPOSE: To define parameters that predict for rapid engraftment after peripheral-blood stem-cell (PBSC) transplantation, progenitor thresholds, the proportion of patients who achieve these thresholds with a standardized mobilization regimen, and the factors that predict for mobilization efficiency. PATIENTS AND METHODS: One hundred and one patients with pretreated lymphoma were mobilized with cyclophosphamide 1.5 g/m2 and granulocyte colony-stimulating factor (G-CSF), with the first apheresis performed when the recovery WBC count was > or = 5.0 x 10(9)/L. The relationship between the number of progenitor cells collected and patient age, sex, diagnosis, prior radiotherapy, and time since last chemotherapy was determined by multivariate analysis. The relationship between these factors, progenitor numbers returned, post-PBSC G-CSF, and hematologic recovery was performed in 81 patients following chemotherapy with carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM protocol). RESULTS: No BEAM recipients had delayed neutrophil recovery beyond 28 days. Delayed platelet recovery occurred in 7.4% and minimum and optimum thresholds of 1 x 10(6) and 3.5 x 10(6) CD34+ cells/kg and 1 x 10(5) and 3.5 x 10(5) granulocyte-macrophage colony-forming cells (GM-CFC)/kg were established. Hematologic recovery was adversely affected by prior treatment with mini-BEAM, and neutrophil recovery was accelerated by post-PBSC G-CSF. The minimum GM-CFC threshold was achieved with a single apheresis in 83% of patients and in 90% with two aphereses. The optimal threshold was achieved with two leukaphereses in 69% of patients. Prior radiotherapy adversely affected mobilization. CONCLUSION: Hematopoietic recovery following PBSC is dependent on progenitor-cell number infused and affect of previous chemotherapy on progenitor quality. Progenitor-cell mobilization is adversely affected by prior radiotherapy. The minimum threshold of GM-CFC required is achieved in most patients with a single apheresis, but an optimal collection usually requires at least two harvests.

Adolescent↗
PubMed1997

Staff strategies and explanations for intervening with challenging behaviours: a replication in a community sample.

Carers' beliefs about challenging behaviours may partially determine their behavioural responses to them. The present study replicated previous work on the beliefs of institution staff and their explanations about interventions for challenging behaviours (Hastings 1996) with a sample of 56 community staff. Many immediate intervention strategies, and the staff motivation for these choices, were in conflict with behavioural approaches to challenging behaviour and would be considered counter-habilitative from this perspective. Staff were able to describe appropriate longer-term interventions. These basic findings confirmed those of previous research with institution staff. However, tentative comparisons suggested that community staff were more likely than institution staff (from previous research) to describe interventions involving the building of relationships with service users and the identification of the underlying causes of the behaviours.

Activities of Daily Living↗
PubMed1996

Peripheral blood stem cell support does not accelerate haemopoietic recovery from miniBEAM chemotherapy.

Intermediate-dose salvage therapy is frequently given for relapsed and resistant lymphomas and is usually intensely myelosuppressive. In an attempt to reduce the haematological toxicity of miniBEAM, one of the commonly used salvage regimens, peripheral blood stem cell (PBSC) support was given to 21 consecutive patients who received miniBEAM chemotherapy. The outcome was compared with a non-randomised control group of consecutive patients who were similar to the supported group apart from the fact that it was not possible to collect PBSC before miniBEAM therapy. Apart from a small, marginally significant difference between the supported and unsupported groups in the number of days for which intravenous antibiotics were required, there were no other differences between the two groups in supportive care required and times to haematological recovery. In conclusion, PBSC support does not accelerate haematological recovery from miniBEAM therapy.

Adolescent↗
PubMed1995

Accessory cells do not contribute to G-CSF or IL-6 production nor to rapid haematological recovery following peripheral blood stem cell transplantation.

Haemopoietic recovery is more rapid after peripheral blood stem cell (PBSC) transplantation than after autologous bone marrow transplantation, and the aim of this study was to assess the role of the large number of lymphocytes and monocytes (accessory cells) in a PBSC leukapheresis product in this rapid regeneration. Haematological recovery was therefore assessed in 10 PBSC recipients with lymphoma or myeloma in whom monocytes and T cells were depleted by a median of 2.3 and 3.3 logs by CD34+ cell selection using the CEPRATE SC stem cell concentration system and compared with recovery in 59 recipients who received whole PBSC. After allowing for the number of progenitor cells reinfused, there was no significant delay in engraftment induced by accessory cell depletion. Plasma levels of granulocyte-colony stimulating factor (G-CSF), granulocyte/monocyte-colony stimulating factor (GM-CSF), interleukin-6 (IL-6), stem cell factor (SCF) and macrophage-inhibition factor-alpha (MIP-1-alpha) during the transplant procedure were similar whether or not accessory cells were given. The G-CSF and IL-6 levels rose between days 5 and 14 post transplantation to approximately 1 ng/ml and 50 pg/ml respectively. This study indicates that accessory cells reinfused with PBSC collections are not responsible for the subsequent cytokine profile or rapid haematological recovery.

Adolescent↗
PubMed1995

Low immunogenicity of therapeutic rat CD45 antibodies when used for pre-treatment of donor organs for transplantation.

Immunoassays for the measurement of human anti-immunoglobulin responses against the CD45 specific rat monoclonals, YTH 24.5 and YTH 54.12, have been developed. The assays are based on a 'double antigen' ELISA system and are reproducible with coefficients of variation of less than 15%. The assays were used to measure anti-immunoglobulin responses in sera from 40 patients who had received kidneys pre-treated with the pair of anti-CD45 monoclonals YTH 24.5 and YTH 54.12. Only two patients elicited a weak human antimurine antibody (HAMA) response.

Animals↗
PubMed1994

Peripheral blood progenitor cells versus bone marrow.

Transplantation of mobilized peripheral blood progenitor cells has generally produced shortening of the period of posttransplant aplasia that is characteristic of bone marrow grafts. However, there has been no large prospective randomized study to compare these two sources of hematopoietic cells or to determine their relative merits. This issue is explored in this review.

Bone Marrow Transplantation↗
PubMed1994

Development of a simplified single-apheresis approach for peripheral-blood progenitor-cell transplantation in previously treated patients with lymphoma.

PURPOSE: The aims of this study were to develop a simplified, safe, and cost-effective peripheral-blood progenitor-cell (PBPC) mobilization protocol. PATIENTS AND METHODS: Twenty-six patients with relapsed or resistant lymphomas were entered onto a sequential cohort study in which schedules of various granulocyte colony-stimulating factor (G-CSF) were administered after cyclophosphamide 1.5 g/m2. Hematologic recovery after high-dose carmustine (BCNU) etoposide, cytarabine, and melphalan (BEAM) chemotherapy was compared with that of 46 patients who received autologous bone marrow transplantation (ABMT) without growth factors and 28 patients who received ABMT followed by G-CSF. RESULTS: When G-CSF (10 micrograms/kg/d) was administered from the day after the cyclophosphamide, neutropenia developed on day 8 followed by an abrupt increase in the WBC count. The optimal time for PBPC harvesting was the day on which the postnadir WBC count was greater than 8.0 x 10(9)/L, as shown by CD34+ cell counts and granulocytic-macrophage colony-forming cell (GM-CFC) assays. The reproducibility of the response was such that routine monitoring of CD34+ cell counts and GM-CFC was not necessary. A single leukapheresis on this day was adequate for prompt hematologic engraftment, and posttransplant G-CSF made little further impact on the rapid recovery. Compared with both control groups, the use of PBPC led to more rapid neutrophil recovery, markedly accelerated platelet recovery, less use of antimicrobial agents and parenteral nutrition, and more than 10 days earlier discharge from hospital. All of these differences were highly significant (P < .01). CONCLUSION: A simplified mobilization protocol is described that requires only one apheresis to achieve rapid hematologic engraftment.

Adult↗
PubMed1990

Isolation and characterization of a membrane-attack-complex-inhibiting protein present in human serum and other biological fluids.

We have previously reported the isolation of a membrane-attack-complex-inhibiting protein (MIP) from human erythrocyte membranes [Watts, Patel & Morgan (1987) Complement 4, 236] and the production of polyclonal antibodies to this protein. Here we report the identification in plasma, urine, saliva and cerebrospinal fluid of a protein immunochemically identical with the membrane-derived MIP. The protein has been isolated from plasma by immunoaffinity chromatography on an anti-(erythrocyte MIP)-Sepharose column and shown by SDS/polyacrylamide-gel electrophoresis to be of similar molecular mass to the erythrocyte protein (55 kDa non-reduced and 65 kDa under reducing conditions). Monoclonal antibodies have been raised against plasma MIP and used to establish a two-site enzyme-linked immunoadsorbent assay, enabling quantification of MIP in plasma, urine and cerebrospinal fluid. Plasma MIP, though not able to incorporate spontaneously into membranes, was deposited on heterologous and homologous erythrocyte membranes during complement activation in a C8-dependent manner. Depletion of MIP from plasma resulted in enhancement of the lytic capacity of the plasma on heterologous erythrocytes.

Animals↗
PubMed1988

The use of the H*1 in predicting marrow recovery following ablative chemotherapy in leukaemia and lymphoma.

Twenty-three cytopenic episodes in 18 patients undergoing ablative chemotherapy for the treatment of leukaemia or lymphoma were monitored from commencement of treatment until recovery, by automated differential counts using the Technicon H*1 Autoanalyser, with particular reference to abnormal white cell flags and large unstained cell (LUC) percentage. The blast flag was indicated in this recovery phase in 100% of patients and in 85% this preceded bone marrow recovery (defined as neutrophil count greater than 0.5 X 10(9)/l) by a mean of 10 days. On average the blast flag was indicated for 8 days in total. Bone marrow function continued to improve in all patients with no evidence of relapse. An increase in the LUC percentage on the differential count reached a maximum at 18 days, 6 days prior to marrow recovery. The ability to detect impending marrow recovery by means of the positive blast flag, may be of great value when patients have been cytopenic for many days.

Autoanalysis↗
PubMed1988

Accurate automated leucocyte differential counts despite profound leucopenia.

The differential white cell counts produced by the Technicon H*1 Autoanalyser in profoundly leucopenic specimens were compared with those carried out by manual differential counting by light microscopy of peripheral blood smears stained with May-Grünwald-Giemsa stain. The correlation achieved allowed the H*1 derived differential count to be reported with confidence.

Blood Cell Count↗
PubMed1988

In vivo and in vitro evidence of cell recovery from complement attack in rheumatoid synovium.

In the previous article we have demonstrated, by quantifying terminal complement complexes in synovial fluid, that membrane attack complex activation occurs in the joint in rheumatoid arthritis. Here we describe evidence of synoviocyte resistance to complement attack in vivo and in vitro. Gel filtration of terminal complement complex positive synovial fluid on Sepharose 2B revealed two forms of terminal complement complex: one form, eluting coincident with the column void, did not react with antibody to the fluid-phase inhibitor of complement membrane attack, the S-protein, suggesting that it was composed of membrane attack complexes, the other form, eluting in the included volume, did react with the anti-S-protein antibody, suggesting that it was composed of functionally inactive SC5b-9 complexes. The high molecular weight membrane attack complex peak was demonstrated by electron microscopy to be composed of membrane vesicles bearing many lesions having the typical appearance of complement membrane attack complexes. No discernible structures were present in the lower molecular weight peak. The effects of non-lethal complement membrane attack on human synoviocytes in culture were also investigated. Synoviocytes were relatively resistant to killing by autologous complement, end-point lysis of optimally antibody-sensitized cells never exceeding 60% even at a serum dilution of 1:2. At serum dilutions of 1:20 or less, no significant cell killing occurred despite a high degree of membrane attack pathway activation, suggesting the existence of resistance and recovery mechanisms. Non-lethal complement membrane attack stimulated the release of toxic reactive oxygen metabolites from synoviocytes. These, and other reactive species released during non-lethal complement attack in vivo, may play a significant role in the pathogenesis of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1980

The effect of rifampicin on the pharmacokinetics of ethynylestradiol in women.

A single dose of Minovlar (50 microgram ethynylestradiol (EE) and 1 mg norethindrone acetate) was given to seven women during treatment with rifampicin (450-600 mg/day) and again one month after stopping rifampicin. Blood samples were taken at intervals over a 24-hour period. The area under the plasma EE versus time curve increased significantly on stopping rifampicin from 1014 +/- 317 pg/ml x h (mean +/- SE) to 1747 +/- 218 pg/ml x h (p less than 0.01). The terminal plasma half-life increased from 2.9 +/- 0.8 h to 6.3 +/- 1.4 h (p less than 0.005). The sex hormone binding globulin (S.H.B.G.) capacity was also reduced from 213.4 +/- 11.5 nmoles to 129.0 +/- 7.7 nmoles/1 after stopping rifampicin. In one patient starting rifampicin who was taking Minovlar as a long-term oral contraceptive, a fall in the plasma EE concentration was associated with a rise in the plasma follicle stimulating hormone concentration. These effects of rifampicin on EE pharmacokinetics are consistent with induction of the microsomal enzymes that metabolise EE.

Adolescent↗