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Biomedical subjects

D Linch

Publications and source records attributed to D Linch.

At least 19 recordsLinked to original sources
PubMed2006

A phase III trial comparing CHOP to PMitCEBO with or without G-CSF in patients aged 60 plus with aggressive non-Hodgkin's lymphoma.

The management of older patients with aggressive non-Hodgkin's lymphoma presents a challenge to the physician. Age is a poor prognostic indicator, due to reduced ability to tolerate and maintain dose-intensive chemotherapy. Generally, older patients demonstrate a lower response rate, reduced survival and increased toxicity, although the majority of large randomised trials exclude older patients. This randomised trial was conducted in patients 60 years or over to compare CHOP (cyclophosphamide 750 mg m(-2), doxorubicin 50 mg m(-2), vincristine 1.4 mg m(-2), prednisolone 100 mg) with PMitCEBO (mitoxantrone 7 mg m(-2), cyclophosphamide 300 mg m(-2), etoposide 150 mg m(-2), vincristine 1.4 mg m(-2), bleomycin 10 mg m(-2) and prednisolone 50 mg). Due to the myelosuppressive nature of these regimens, patients were also randomised to the addition of G-CSF. The formal results of this trial with long-term follow-up are now reported. Data were analysed to assess efficacy and toxicity. Overall response rate was 84% in the CHOP arm and 83% in the PMitCEBO arm, with overall response rates of 83% for the use of G-CSF and 84% for no G-CSF. At median 44 months follow-up, there was no significant difference in failure-free, progression-free or overall survival between the CHOP and PMitCEBO arms. At 3 years, the actuarial failure-free survival was 44% in CHOP recipients and 42% in PMitCEBO recipients and the 3-year actuarial overall survival was 46% and 45% respectively. There was no significant difference in the failure-free, progression-free or overall survival with the addition of G-CSF.

Age Factors↗
PubMed2005

Comparison of CHOP versus CIOP in good prognosis younger patients with histologically aggressive non-Hodgkin lymphoma.

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) has been the standard chemotherapy regimen used for diffuse large cell lymphomas for over 30 years. Idarubicin is a 4-demethoxy-anthracycline analogue of daunorubicin that has proven activity in non-Hodgkin lymphoma, and has been reported to cause less cardiotoxicity. We therefore initiated a randomised trial of standard dose CHOP versus CIOP (cyclophosphamide, idarubicin, vincristine and prednisolone), in which doxorubicin 50 mg/m2 was substituted by idarubicin 10 mg/m2, a dose thought to have equivalent anti-lymphoma activity. This trial was closed prematurely after 211 patients had completed therapy when a lower complete remission (CR) rate was noted in the CIOP arm. The formal results with long-term follow up are now reported. Overall response rate was 84% in the CHOP arm and 78% in the CIOP arm, CR rates were 70% and 52% respectively in all patients (P=0.013) and 73% and 52% respectively for the eligible patients (P=0.0084). At a median of 8 years follow-up, 4-year progression-free survival for all patients was 56% in the CHOP arm and 40% in the CIOP arm (P=0.0096). Overall survival for all patients was 65% in the CHOP arm and 56% in the CIOP arm (P=0.14). Results for eligible patients were comparable. CIOP containing idarubicin at a dose of 10 mg/m2 is clearly inferior to standard CHOP.

Adult↗
PubMed2004

Fludarabine, adriamycin and dexamethasone (FAD) in newly diagnosed advanced follicular lymphoma: a phase II study by the British National Lymphoma Investigation (BNLI).

The optimal first-line treatment for symptomatic patients with advanced stage follicular lymphoma remains unclear. Fludarabine-based combination regimens have been extensively used in relapsed disease and merit consideration as first-line therapy. We here report the results of a phase II study of FAD (fludarabine, adriamycin, dexamethasone) regimen in 30 patients with advanced stage follicular lymphoma requiring treatment. The response rate was in excess of 90% with 39% achieving a complete remission. The major toxicity was myelosuppression, but only 3% of cycles were associated with grade IV leucopenia. The high response rate has not translated into major improvements in failure-free survival and consideration must be given to alternative treatment modalities to consolidate the high rate of initial responses.

Administration, Oral↗
PubMed2004

Long-term follow-up of patients treated with radiotherapy alone for early-stage histologically aggressive non-Hodgkin's lymphoma.

Historically localised aggressive non-Hodgkin's lymphoma (NHL) has been treated with involved field radiotherapy (RT), chemotherapy, or a combination of both modalities. The current weight of evidence supports a preference for combined modality treatment (CMT). Increased patient age at diagnosis is well recognised as a poor prognostic indicator in NHL, but despite this some perceive CMT as too toxic for use in the elderly. As a result, some older patients continue to be offered RT alone. Here, we present long-term follow-up of 377 adults of all ages treated with RT alone for early-stage diffuse large-cell lymphoma on British National Lymphoma Investigation trials between 1974 and 1997. 10-year cause-specific survival in patients older than 60 years was poor and significantly inferior to that in younger patients (47 and 75% respectively; P<0.001). There is growing evidence that short-course chemotherapy, with or without RT, is superior to RT alone in early-stage aggressive NHL, in elderly as well as in younger patients. Increased age alone should not exclude patients from systemic treatment for early-stage aggressive NHL.

Adolescent↗
PubMed2004

Neurological complications following alemtuzumab-based reduced-intensity allogeneic transplantation.

We report the incidence, characteristics and outcome of neurological complications occurring following reduced-intensity conditioning (RIC) in 85 patients who received a related/unrelated donor stem cell transplantation following therapy with alemtuzumab, fludarabine and melphalan. Six patients (probability 8.9%) developed severe neurological complications at a median of 151 days (24-334 days). Five of them presented with progressive peripheral sensori-motor radiculo-neuropathy and/or myelitis, preceded by one or more viral reactivation/infection. Despite treatment with immunoglobulins/plasmapheresis/steroids, four died of respiratory failure due to progressive peripheral neurophathy. Viral infection was identified as the only risk factor for the development of neurological complications. Patients who are treated with alemtuzumab-based RIC may have a lower risk of developing regimen-related neurological complications, but are more susceptible to develop peripheral radiculo-neuropathy or myelitis. This phenomenon may be possibly related to viral infection associated with delayed immunological recovery or immunological dysregulation caused by alemtuzumab-induced T-cell depletion.

Adolescent↗
PubMed2001

Mitoxantrone is superior to doxorubicin in a multiagent weekly regimen for patients older than 60 with high-grade lymphoma: results of a BNLI randomized trial of PAdriaCEBO versus PMitCEBO.

A prospective, multicenter, randomized trial was undertaken to compare the efficacy and toxicity of adriamycin with mitoxantrone within a 6-drug combination chemotherapy regimen for elderly patients (older than 60 years) with high-grade non-Hodgkin lymphoma (HGL) given for a minimum of 8 weeks. A total of 516 previously untreated patients aged older than 60 years were randomized to receive 1 of 2 anthracycline-containing regimens: adriamycin, 35 mg/m(2) intravenously (IV) on day 1 (n = 259), or mitoxantrone, 7 mg/m(2) IV on day 1 (n = 257); with prednisolone, 50 mg orally on days 1 to 14; cyclophosphamide, 300 mg/m(2) IV on day 1; etoposide, 150 mg/m(2) IV on day 1; vincristine, 1.4 mg/m(2) IV on day 8; and bleomycin, 10 mg/m(2) IV on day 8. Each 2-week cycle was administered for a minimum of 8 weeks in the absence of progression. Forty-three patients were ineligible for analysis. The overall and complete remission rates were 78% and 60% for patients receiving PMitCEBO and 69% and 52% for patients receiving PAdriaCEBO (P =.05, P =.12, respectively). Overall survival was significantly better with PMitCEBO than PAdriaCEBO (P =.0067). However, relapse-free survival was not significantly different (P =.16). At 4 years, 28% of PAdriaCEBO patients and 50% of PMitCEBO patients were alive (P =.0001). Ann Arbor stage III/IV, World Health Organization performance status 2-4, and elevated lactate dehydrogenase negatively influenced overall survival from diagnosis. In conclusion, the PMitCEBO 8-week combination chemotherapy regimen offers high response rates, durable remissions, and acceptable toxicity in elderly patients with HGL.

Aged↗
PubMed2001

Autologous stem cell transplantation for paediatric-onset polyarteritis nodosa: changes in autoimmune phenotype in the context of reduced diversity of the T- and B-cell repertoires, and evidence for reversion from the CD45RO(+) to RA(+) phenotype.

We have studied immune reconstitution in a patient with paediatric-onset polyarteritis nodosa treated with high-dose immunosuppressive agents followed by stem cell rescue. The patient developed several new autoimmune phenomena over the 18 months after immunosuppression and stem cell rescue. Flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR) heteroduplex and isotype-specific RT-PCR analysis of immunoglobulin expression showed that the T- and B-cell repertoires were highly restricted in the first few months after treatment. The dominant T-cell clones seen after reconstitution were persistently expanded, were different from those which could be demonstrated before autologous stem cell transplantation, and were in the CD8(+) population. Our data also show that 12 months after treatment these expanded T-cell clones were within the CD45RA(+) population, suggesting that reversion from the CD45RO(+) to the CD45RA(+) phenotype had occurred in vivo.

Adult↗
PubMed2001

Current treatment of follicular and low-grade non-Hodgkin's lymphoma.

Patients with low-grade non-Hodgkin's lymphoma (NHL) have a median survival of 4-8 years from diagnosis and a cause-specific survival of about 10 years. Radiotherapy can be curative in a small proportion of patients with very localized disease, but the majority of patients have advanced disease at diagnosis and it is not clear that any current therapy is curative in this situation. While in many instances patients with high-grade NHL are cured by chemotherapy, those with low-grade NHL, despite impressive response rates, almost invariably relapse. A 'watch-and-wait' strategy can therefore delay the onset of chemotherapy by 2-3 years, without affecting survival. Results with autologous stem cell transplantation have been similarly disappointing to date. Rituximab is a human-mouse chimeric monoclonal antibody that represents a novel approach to treatment of low-grade NHL, targeting malignant cells without the side effects associated with chemotherapy. A pivotal study has demonstrated a response rate of 56% in relapsed or refractory low-grade NHL. The relatively benign side-effect profile means rituximab can be used early in the disease process, and in combination with chemotherapeutic regimens and autologous transplantation. Ongoing and future studies will define the optimal role of rituximab in treatment of low-grade NHL.

Antibodies, Monoclonal↗
PubMed1999

High dose therapy for Hodgkin's disease.

High dose therapy with haemopoietic stem cell support is now the standard approach to patients failing conventional dose chemotherapy for Hodgkin's disease (HD) although there is a lack of data from randomized trials substantiating this practise. There is even less data to justify transplanting patients in first complete remission although this might be appropriate for a small minority of patients. Approximately 40% of patients receiving high dose salvage therapy have achieved prolonged progression free survival with slightly better results in some centres. Of those who relapse after high dose therapy, a significant proportion will have a further good, albeit usually transient, response to conventional dose therapy which contrasts markedly with the situation in non-Hodgkin's lymphoma. As the results of front-line therapy for HD improve, there will be selection of the very worst prognosis patients for high dose therapy, and there will be an increasing need to develop improved salvage strategies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

c-kit proto-oncogene exon 8 in-frame deletion plus insertion mutations in acute myeloid leukaemia.

Genomic DNA from 60 cases of acute myeloid leukaemia (AML) was screened for mutations in the c-kit gene. DNA from all 21 exons was subjected to polymerase chain reaction (PCR) amplification and analysis by conformation sensitive gel electrophoresis (CSGE); exons showing altered CSGE patterns were then sequenced. Mutations were identified only in those patients with inv(16) (3/7 cases) or t(8;21) (1/2 cases) and comprised three in-frame deletion plus insertion mutations (exon 8) and one point mutation (exon 10, GTA --> ATA, Val530Ile). Exons 8 and 10 were then analysed in 31 further cases of inv(16) (n = 14) and t(8;21) (n = 17), revealing four additional exon 8 in-frame deletion plus insertion mutations, all of which were in cases of inv(16). All exon 8 in-frame deletion plus insertion mutations (n = 7) involved the loss or replacement of the codon for Asp419 which is highly conserved cross species and is located in the receptor's extracellular domain. The high frequency of the c-kit proto-oncogene exon 8 deletion plus insertion mutations in AML suggests an essential role for this region of the receptor's extracellular domain. The association with inv(16) invites speculation as to the link between these two changes in the pathogenesis of AML.

Acute Disease↗
PubMed1999

Identification of the t(15;17) in AML FAB types other than M3: evaluation of the role of molecular screening for the PML/RARalpha rearrangement in newly diagnosed AML. The Medical Research Council (MRC) Adult Leukaemia Working Party.

Acute promyelocytic leukaemia (APL) is characterized by the t(15;17) leading to the formation of PML-RARalpha and RARalpha-PML fusion genes; this rearrangement has been considered both diagnostic for, and restricted to, this subtype of acute myeloid leukaemia (AML FAB M3). We describe two cases of AML with the t(15;17) associated with a PML/RARalpha rearrangement which lacked typical APL morphology, classified as FAB M1 and M2 respectively. In both cases morphological review revealed small populations of cells which exhibited some features associated with APL. In the case classified as M1, PML immunofluorescence studies revealed the classic microparticulate nuclear staining pattern as observed in typical cases of APL with the t(15;17). Similarly, blasts from this case were found to be sensitive to ATRA in vitro as determined by NBT reduction test and by normalization of the PML nuclear body staining pattern. To determine the frequency of PML/RARalpha rearrangements in FAB subtypes other than M3, 530 patients from the MRC AML trials were screened using nested RT-PCR. Only one individual, initially classified as M5 with a normal karyotype, was found to have a PML/RARalpha rearrangement. The diagnosis was revised to M3 variant on subsequent morphological review. In conclusion, this study demonstrates that, in rare cases, the t(15;17) is not restricted to patients with M3 morphology as defined by current FAB criteria. Therefore, although we consider cytogenetic analysis of newly diagnosed cases of AML to be mandatory, our data suggests that routine molecular screening for PML/RARalpha rearrangements is not justified and should be reserved for those cases displaying features which may be suspicious of APL even if such cells comprise only a minority of the total population.

Adolescent↗
PubMed1997

Imprecision of counting CFU-GM colonies and CD34-expressing cells.

Determinations of committed haemopoietic progenitor cells, namely CFU-GM (colony-forming unit-granulocyte/macrophage) and of CD34-expression haemopoietic cells as assessed by multiparameter flow cytometry are routine diagnostic tools in haemopoietic cell therapy. Generally, the tests are used to optimise the timing and management of cytapheresis and to assess the engraftment potential of the harvested cells. Both measurements, however, are at best surrogate markers, as an adequate routine test which effectively assesses the short- and long-term repopulating haemopoietic cell is not available. Nonetheless, cell threshold doses have been established. Above these thresholds rapid engraftment is almost invariable but below these thresholds the outcome is variable. In this study we have focussed on the imprecision in counting haemopoietic cells, as assessed as CFU-GM and as CD34-expressing cells. The data on both tests have been analysed from six European institutions. The coefficient of variation in CFU-GM colony counting was about 30%, whereas the coefficient of variation in flow cytometric counting of CD34-expressing cells was about 10%. These data suggest that the technical imprecision in enumerating progenitor cells, particularly CFU-GM, at low levels, might make a major contribution to the clinical variability observed after transplantation of sub-threshold progenitor cell dose.

Antigens, CD34↗
PubMed1996

In-vitro clonogenicity of mobilized peripheral blood CD34-expressing cells: inverse correlation to both relative and absolute numbers of CD34-expressing cells.

The determination of CD34-expressing cells by multiparameter flow cytometry is now widely used to estimate the reconstitution potential of cells harvested by cytapheresis for peripheral blood stem cell and progenitor cell transplantation. There is a correlation between the number of CD34-expressing cells collected and committed progenitor cells (CFU-GM and BFU-E) capable of forming colonies in vitro, but there is considerable variation in the proportion of CD34-expressing cells capable of clonogenic growth. The data in this study of 782 cytapheresis samples indicates that there is a negative correlation between the clonogenicity of the CD34-expressing cells and the absolute number or the proportion of CD34-expressing cells within the harvest. In 116 samples the proportion of CD34-expressing cells co-expressing the CD45-RA-antigen (a subset of CD34-expressing cells which includes virtually all clonogenic cells in terms of CFU-GM) was determined, but this did not help to identify the clonogenicity of a given sample. These findings may have clinical relevance, particularly when mobilization is judged to be relatively poor or when a good harvest is to be divided for multiple high-dose procedures.

Antigens, CD34↗
PubMed1995

The polymerase chain reaction in the demonstration of monoclonality in T cell lymphomas.

AIMS: To evaluate polymerase chain reaction (PCR) amplification of T cell receptor (TCR) beta and gamma chain genes as a means of demonstrating monoclonality in T cell lymphomas using histological samples; to compare the performance of PCR with Southern blot analysis. METHODS: TCR-beta, TCR-gamma and immunoglobulin heavy chain (IGH) genes were analysed using PCR in 55 cases of T cell lymphoma (28 frozen tissue and 27 paraffin wax embedded samples), diagnosed using morphological and immunohistochemical criteria. The 28 frozen samples were subjected to Southern blot analysis using TCR-beta, TCR-gamma and IGH gene probes. Twenty five B cell lymphomas and 21 non-neoplastic lymphoid tissue samples were used as controls. RESULTS: Using TCR-beta PCR, monoclonality was detected in 24 (44%) of 55 T cell lymphomas compared with 43 (78%) of 55 using TCR-gamma PCR and in 82% with both techniques. Five (9%) of 55 T cell lymphomas were IGH PCR positive. None of the non-neoplastic lymphoid control samples were PCR positive. All B cell lymphomas showed a polyclonal pattern with TCR-beta PCR while a single B cell lymphoma was positive using TCR-gamma primers. With TCR-beta PCR, a monoclonal result was seen in 12 (43%) of 28 frozen samples of T cell lymphoma, compared with 23 (82%) of 28 using Southern blot analysis. With TCR-gamma PCR, 19 (68%) of 28 frozen tissue samples were positive, compared with 26 (93%) of 28 using Southern blot analysis. A single case showed IGH rearrangement by Southern blot analysis. CONCLUSION: TCR-gamma PCR should be the method of choice for analysis of clonality in paraffin wax embedded sections of lymphoproliferative lesions, as TCR-beta PCR has a high false negative rate. Southern blot analysis remains the most successful technique when sufficient fresh tissue samples and resources are available.

Base Sequence↗
PubMed1990

Haemopoietic growth factors.

The availability of recombinant haemopoietic growth factors has permitted more precise in vitro experiments and human in vivo studies to be performed. In general, the results have been in accord with expectations from previous in vitro studies. The clinical exploitation of the haemopoietic growth factors offers great promise but careful studies are required to define their value. The effects of some growth factors are multiple and complex, and it cannot be assumed that improvements in blood cell counts are per se beneficial to the patient under all circumstances. Randomized controlled trials with clinical end-points are now essential. In the situation of chemotherapy-induced neutropenia, large studies would be required to show an improvement in mortality although lesser morbidity would be easier to demonstrate. In the field of cancer therapy the major benefit of the haemopoietic growth factors will be if they permit dosage escalation and there is a consequent improvement in response rate and long-term survival. This will require careful patient selection and large, probably multicentre, trials. It is also likely that such studies will be limited by the development of severe thrombocytopenia and an effective means to ameliorate this (perhaps the elusive thrombopoietin) will be required. The possibility of using haemopoietic growth factors as an adjunct to the treatment of severe infections is enticing, but designing a trial to evaluate this possibility is fraught with difficulties. Finally, it must be noted that all the studies reported to date use single factors. This is just the beginning and the use of other factors and synergistic combinations may give greater efficacy without increased toxicity.

Bone Marrow Diseases↗
PubMed1989

The c-myc oncogene is regulated independently of differentiation in myeloid cell lines.

Human myeloid leukaemia (U-937 and HL-60) cells when incubated at low cell densities with human recombinant gamma-interferon underwent functional maturation without any loss of proliferative potential relative to uninduced cells. In addition, the proportion of cells in S,G2/M and levels of c-myc oncogene (mRNA and protein) were maintained at the same level as those of untreated control cells. However, cells grown under similar conditions but with retinoic acid matured to the same extent but became growth inhibited with concomitant reductions in the proportion of cells in S,G2/M and levels of c-myc mRNA and protein. These studies indicate firstly that c-myc levels are regulated independently from differentiation in myeloid (non lymphoid) cells, secondly that gamma-interferon can induce differentiation without growth arrest under conditions of low cell density and thirdly emphasise the close association of c-myc expression with proliferative capacity.

Cell Cycle↗
PubMed1987

The inheritance of a Macaca fascicularis red cell antigen detected by CAMPATH-1 antibody.

CAMPATH-1 monoclonal antibody is reactive with human lymphocytes and monocytes and it has been shown to bind to antigens on the red cells of a number of primate species, including Macaca fascicularis. Our study within a closed colony of breeding M. fascicularis monkeys has confirmed this finding, and shown that the antibody identified a single red cell antigen inherited in Mendelian fashion as a dominant character. We have, further, confirmed that the antigen is present on blood lymphocytes, even in animals whose red cells are negative. This CAMPATH-1 antigen can therefore serve as a useful red cell marker in experiments involving bone marrow transplantation or blood transfusion.

Animals↗