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Biomedical subjects

T J Littlewood

Publications and source records attributed to T J Littlewood.

At least 19 recordsLinked to original sources
PubMed2006

hTERT, the catalytic component of telomerase, is downregulated in the haematopoietic stem cells of patients with chronic myeloid leukaemia.

Telomere shortening is associated with disease progression in chronic myeloid leukaemia (CML). To investigate the biology and regulation of telomerase in CML, we evaluated expression of the telomerase components, its regulators and several telomeric-associated proteins. Quantitative real-time-polymerase chain reaction (PCR) was used to compare gene expression in the CD34+/leukaemic blast cells of 22 CML patient samples to the CD34+ cell population of healthy individuals. hTERT, the catalytic component of telomerase, was downregulated in eight of 12 chronic phase (CP) patients (P = 0.0387). Furthermore, hTERT was significantly downregulated in two of three patients in accelerated phase (AP) and seven of seven patients in blast crisis (BC), P = 0.0017. Expression of hTR and telomeric-associated proteins TEP1, TRF1, TRF2, tankyrase and PinX1 was high in the majority of CP and AP patients. With the exceptions of TEP1 and hTR, expression of these factors was highest in CP and decreased during disease progression. Expression of c-Myc, a positive regulator of hTERT transcription, correlated with hTERT expression and decreased with disease progression, falling below control levels in BC. hTERT levels were increased in CP patients following successful treatment with imatinib, relative to untreated CP patients. We suggest that reduced hTERT expression directly causes the shortened telomeres observed in CML.

Adolescent↗
PubMed2004

Efficacy and safety of oral fludarabine phosphate in previously untreated patients with chronic lymphocytic leukemia.

PURPOSE: A prospective, multicenter, open-label, phase II clinical trial to assess oral fludarabine phosphate treatment in terms of safety, efficacy, and quality of life. Reference to a historical group of patients treated with the intravenous (IV) formulation allowed the two formulations to be compared. PATIENTS AND METHODS: Patients with previously untreated B-cell chronic lymphocytic leukemia received 10-mg tablets of fludarabine phosphate to a dose of 40 mg/m(2)/d for 5 days, repeated every 4 weeks, for a total of six to eight cycles. Efficacy was assessed using International Workshop on Chronic Lymphocytic Leukemia and National Cancer Institute criteria for response. Safety monitoring included WHO toxicity grading for adverse events. Quality of life was also assessed. RESULTS: Eighty-one patients received treatment. According to International Workshop on Chronic Lymphocytic Leukemia criteria, the overall response rate was 71.6% (complete remission, 37.0%; partial remission, 34.6%). The response rate using National Cancer Institute criteria was 80.2% (complete remission, 12.3%; partial remission, 67.9%). Median time to progression was 841 days (range, 28 to 1,146 days). The most frequently reported grade 3/4 toxicity was myelosuppression. WHO grade 3/4 hematological toxicities included granulocytopenia (32.1%), anemia (9.9%), and thrombocytopenia (4.9%). Gastrointestinal toxicity was more common with the oral formulation than with IV fludarabine phosphate, but was generally mild to moderate and did not require treatment. Statistically significant improvements in mean emotional and insomnia quality-of-life scores were seen after treatment. CONCLUSION: This study demonstrates that oral fludarabine phosphate is clinically effective and generally well tolerated by patients with previously untreated B-cell chronic lymphocytic leukemia. Oral fludarabine phosphate has a similar clinical efficacy and safety profile to the IV formulation. Oral fludarabine phosphate does not adversely affect quality of life and may improve emotional and insomnia scores.

Administration, Oral↗
PubMed2004

Favourable outcome for patients with myeloid disorders treated with fludarabine-melphalan reduced-intensity conditioning and allogeneic bone marrow stem cell transplantation without the use of T-lymphocyte-depleting antibodies.

We report the use of reduced-intensity conditioning (RIC)-matched sibling allogeneic bone marrow stem cell transplantation as a method of establishing a graft-vs.-leukaemia (GvL) effect against myeloid disorders using a fludarabine-melphalan protocol without the use of T-lymphocyte-depleting antibodies. The 16 patients in this group had predominantly poor-risk acute myeloid leukaemia (AML) (n=10), AML/myelodysplasia (MDS) (n=2) and MDS (n=4). All but one patient achieved full haematopoietic engraftment. Thirteen of 16 patients are alive and in continued complete remission on completion of this study with a median follow-up of 426 d (range 83-1524). The actuarial 4 yr disease-free and overall survival is 79% for both. Only one patient relapsed following transplant, giving a relapse rate of 6% during the study period. The treatment-related mortality was 13% (n= 2). Overall, acute graft-vs.-host disease (GvHD) occurred in 53% (8/15), with acute GvHD grade II or above occurring in 47% (7/15). In the 13 evaluable patients, chronic GvHD occurred in 46% (6/13), with this being extensive in three patients. These results suggest that a GvL effect can be delivered against poor-risk myeloid disorders with a low non-relapse mortality using this fludarabine-melphalan RIC protocol.

Acute Disease↗
PubMed2002

Multivariate regression analyses of data from a randomised, double-blind, placebo-controlled study confirm quality of life benefit of epoetin alfa in patients receiving non-platinum chemotherapy.

Cancer-related anaemia is associated with a wide spectrum of symptoms that can negatively affect quality of life. Because epoetin alfa has demonstrated efficacy in correcting cancer-related anaemia, the impact of this treatment on quality of life was evaluated in a multinational, randomised, double-blind, placebo-controlled trial in 375 anaemic cancer patients receiving non-platinum-based chemotherapy. The cancer-specific measures of quality of life included the general scale (FACT-G Total) and fatigue subscale (FACT-An Fatigue subscale) of the Functional Assessment of Cancer Therapy-Anaemia and the Cancer Linear Analogue Scales measuring energy, ability to do daily activities, and overall quality of life. These measures were also used to examine the relationship between haemoglobin levels and quality of life. Both univariate and multiple linear regression analyses of quality of life data were performed. Results of the univariate analysis have been reported previously. The a priori-planned multiple linear regression analysis, which accounted for the effects of disease progression and several other possibly confounding variables on quality of life, showed a significant advantage for epoetin alfa over placebo for the five scales (all, P<0.05), and confirmed the results of the univariate analysis. For cancer-specific measures, significant correlations were demonstrated between baseline haemoglobin and quality of life (r, range: 0.14-0.26, all P<0.05) and between change in haemoglobin and change in quality of life (r, range: 0.26-0.34, all P<0.01). These findings provide evidence that increasing haemoglobin levels by epoetin alfa administration can significantly improve cancer patients' quality of life.

Activities of Daily Living↗
PubMed2002

Lymphoplasmacytoid lymphoma presenting as severe osteoporosis.

We report four cases presenting with severe osteoporosis which on further investigation were found to have an underlying lymphoplasmacytoid lymphoma (LPL). Common secondary causes of osteoporosis were excluded in each case. Three of the cases responded to treatment with a biphosphonate. As these lymphomas share some common pathological and clinical features with multiple myeloma (MM) an association with osteoporosis is likely to represent more than a coincidental finding. The incidence of osteoporosis occurring with LPL will become clearer if routine imaging is carried out in patients at presentation. Issues relating to the treatment of the osteoporosis as well as the lymphoma arise in patients that present in this way. Based on the model of bone disease in MM, correlating serum levels of osteoclast activating cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumour necrosis factor (TNF) with the actual finding of bone disease provides a basis for future research into the pathogenesis and management of bone disease in these rare forms of low grade non-Hodgkin's lymphoma.

Aged↗
PubMed2002

Treatment of myelodysplasia with oral cyclosporin.

Recent studies have shown a good response to immunosuppressive treatment with cyclosporin A (CSA) in patients with the myelodysplastic syndrome (MDS). We have treated six transfusion-dependent MDS patients with CSA for a minimum of 3 months. None of these patients showed a significant response, while the drug was withdrawn in 3/6 patients because of intolerable side-effects. Two reasons for the failure of this treatment in our patients can be advanced. Firstly, the hypoplastic variant of MDS predominated in previous studies in contrast to ours. Secondly, the concomitant use of other immunosuppressive agents in previous studies might have enhanced the effect of CSA. We suggest further therapeutic trials of CSA in MDS, selecting patients on the basis of in vitro studies that predict an immunological basis for their disease, to assess its efficacy in prolonging survival.

Administration, Oral↗
PubMed2001

Effects of epoetin alfa on hematologic parameters and quality of life in cancer patients receiving nonplatinum chemotherapy: results of a randomized, double-blind, placebo-controlled trial.

PURPOSE: This randomized, double-blind, placebo-controlled clinical trial assessed the effects of epoetin alfa on transfusion requirements, hematopoietic parameters, quality of life (QOL), and safety in anemic cancer patients receiving nonplatinum chemotherapy. The study also explored a possible relationship between increased hemoglobin and survival. PATIENTS AND METHODS: Three hundred seventy-five patients with solid or nonmyeloid hematologic malignancies and hemoglobin levels < or = 10.5 g/dL, or greater than 10.5 g/dL but < or = 12.0 g/dL after a hemoglobin decrease of > or = 1.5 g/dL per cycle since starting chemotherapy, were randomized 2:1 to epoetin alfa 150 to 300 IU/kg (n = 251) or placebo (n = 124) three times per week subcutaneously for 12 to 24 weeks. The primary end point was proportion of patients transfused; secondary end points were change in hemoglobin and QOL. The protocol was amended before unblinding to prospectively collect and assess survival data 12 months after the last patient completed the study. RESULTS: Epoetin alfa, compared with placebo, significantly decreased transfusion requirements (P =.0057) and increased hemoglobin (P <.001). Improvement of all primary cancer- and anemia-specific QOL domains, including energy level, ability to do daily activities, and fatigue, was significantly (P <.01) greater for epoetin alfa versus placebo patients. Although the study was not powered for survival as an end point, Kaplan-Meier estimates showed a trend in overall survival favoring epoetin alfa (P =.13, log-rank test), and Cox regression analysis showed an estimated hazards ratio of 1.309 (P =.052) favoring epoetin alfa. Adverse events were comparable between groups. CONCLUSION: Epoetin alfa safely and effectively ameliorates anemia and significantly improves QOL in cancer patients receiving nonplatinum chemotherapy. Encouraging results regarding increased survival warrant another trial designed to confirm these findings.

Activities of Daily Living↗
PubMed2001

Erythropoietin for the treatment of anemia associated with hematological malignancy.

Anemia is common in patients with hematological malignancy. Most patients will have their anemia attributed to the anemia of chronic disease. The anemia of chronic disease is caused by cytokine mediated suppression of erythropoiesis and low serum erythropoietin levels are found in the majority of patients with cancer. Many of these anemic patients will be symptomatic with fatigue. Data from many studies indicates that treatment of anemic patients with erythropoietin will increase their hemoglobin concentration, decrease transfusion need and also improve their quality of life. A recent study also suggests that improving the hemoglobin level may improve the patients' prognosis but this finding needs to be confirmed.

Anemia↗
PubMed2001

The impact of hemoglobin levels on treatment outcomes in patients with cancer.

Clinical trials and surveys have shown that a majority of patients with cancer have low hemoglobin levels as a result of the disease and/or treatment. Clinical trials also have shown that the impact of anemia may be more insidious and far-reaching than generally appreciated. Specifically, studies have shown that low hemoglobin levels have significant impact on treatment outcomes, including survival. The mechanisms by which treatment efficacy and survival are compromised have not been fully elucidated but may include cellular compromise (eg, impaired tumor oxygenation), or more general patient compromise (eg, decreased quality of life and treatment delivery). Recent studies have suggested that increasing hemoglobin levels with recombinant human erythropoietin (r-HuEPO, epoetin alfa) have resulted in better outcomes following radiotherapy, chemotherapy, and the combined-treatment modality.

Anemia↗
PubMed2001

Paraneoplastic pemphigus: an association with fludarabine?

Paraneoplastic pemphigus is a relatively recently described immunobullous disease with characteristic features. We report three cases of paraneoplastic pemphigus in adult men with chronic lymphocytic leukaemia arising within a week of completion of treatment with fludarabine. In all cases, withdrawal of fludarabine and treatment of the blistering was associated with marked cutaneous improvement. Fludarabine, a synthetic nucleoside analogue, which has only been available in Britain since 1994, is known to be associated with autoimmune phenomena and may have been involved in the development of paraneoplastic pemphigus in these cases.

Antineoplastic Agents↗
PubMed2001

A multicentre, open, non-comparative phase II study of a combination of fludarabine phosphate, cytarabine and granulocyte colony-stimulating factor in relapsed and refractory acute myeloid leukaemia and de novo refractory anaemia with excess of blasts in transformation.

The primary objective of this study was to determine the complete remission (CR) rate achieved with the FLAG (fludarabine phosphate, cytarabine and granulocyte colony-stimulating factor) regimen in patients with relapsed or refractory acute myeloid leukaemia (AML) or de novo refractory anaemia with excess of blasts in transformation (RAEB-t). Secondary objectives were to evaluate survival and toxicity. Induction treatment consisted of between one and two courses of FLAG. Patients achieving CR received between one and two courses of consolidation treatment. Eighty-three of the 89 patients entering the study were eligible for assessment. CR rates were: 17 out of 21 (81%) in late relapse AML (Group 1), 13 out of 44 (30%) in early relapse/refractory AML (Group 2), and 10 out of 18 (56%) in de novo RAEB-t (Group 3). Thirty-four of the 40 responders (85%) achieved CR after one induction course. Median survival times were 1.4 years, 3 months and 1.6 years in Groups 1, 2 and 3 respectively. Other than myelosuppression, the FLAG regimen was not generally associated with clinically significant toxicity and was well tolerated by most patients including the elderly. The FLAG regimen offers a very effective alternative treatment for CR induction in poor prognosis adult patients with either relapsed or refractory AML or de novo RAEB-t. FLAG delivers high-dose treatment without increasing overall toxicity, an approach which is of particular value in older patients, who constitute the majority in these diseases. It is therefore an important advance in developing new treatment options for these patients.

Acute Disease↗
PubMed2001

Platelet activation via the collagen receptor GPVI is not altered in platelets from chronic myeloid leukaemia patients despite the presence of the constitutively phosphorylated adapter protein CrkL.

In this study, we show that the adapter proteins CrkL and Cbl undergo increases in tyrosine phosphorylation and form an intracellular complex in platelets stimulated with the snake venom toxin convulxin, a selective agonist at the collagen receptor glycoprotein VI (GPVI). Constitutive tyrosine phosphorylation of CrkL has previously been reported in platelets from chronic myeloid leukaemia (CML) patients. This was confirmed in the present study, and shown to result in a weak constitutive association of CrkL with Cbl and a number of other unidentified tyrosine-phosphorylated proteins. There was no further increase in phosphorylation of CrkL in CML platelets in response to GPVI activation, whereas phosphorylation of Cbl and its association with CrkL were potentiated. In addition, this was accompanied by a small increase in p42/ 44 mapkinase (MAPK) activity in CML platelets. The functional consequence of the presence of constitutively phosphorylated proteins in CML platelets was investigated by measurement of aminophospholipid exposure and alpha-granule secretion. This revealed little alteration in the concentration-response curves for either in CML platelets stimulated via GPVI, although maximal levels of P-selectin were depressed. Despite the minimal effect on platelet activation in CML patients, we cannot exclude a role for CrkL or Cbl in signal transduction pathways stimulated via GPVI.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Erythropoietin: a paradigm for the development of practice guidelines.

Erythropoietin (EPO) is an endogenous hormone produced in the kidney that regulates red blood cell production within the body. Since the cloning and first clinical introduction of recombinant erythropoietin (epoetin) in the late 1980s indications and usage of epoetin have expanded significantly. It is estimated that as many as one third of patients with substantial anemia (hemoglobin less than 10.0 g/dL) resulting from chemotherapy for cancer are treated with epoetin. Though use of epoetin may avoid the inconvenience and infectious risk of blood transfusions, it is expensive and its benefit in some clinical scenarios has been modest. Like many new technologies, strong evidence suggesting situations where the benefit is high has lagged behind its adoption by patients and practitioners. As well, epoetin is expensive and third party payers do not always reimburse it. Research suggests there is considerable variation in epoetin usage in practice. To provide guidance to hematology/oncology specialists regarding use of epoetin, the American Society of Hematology (ASH) and the American Society of Clinical Oncology (ASCO) proposed that the Agency for Healthcare Research and Quality (AHRQ) fund an evidence review by one of the Evidence-based Practice Centers (EPC) that would be used to develop evidence-based guidelines for members of the society. This review highlights principles of evidence-based medicine, distills and appraises the evidence in the published literature that supports the use of epoetin, and presents evidence-based recommendations for use of epoetin in situations where benefit is substantiated by high-quality studies. As well, this review addresses some of the difficulties of performing clinical research in this area, provocative research findings that will require further study, and suggestions regarding epoetin in those areas where further strong evidence has yet to be developed.

Anemia↗
PubMed2000

Telomere length shortening in chronic myelogenous leukemia is associated with reduced time to accelerated phase.

Telomere shortening is associated with disease evolution in chronic myelogenous leukemia (CML). We have examined the relationship between diagnostic telomere length and outcome in 59 patients with CML who entered into the MRC CMLIII Trial by Southern blot hybridization using the (TTAGGG)(4) probe. Age-adjusted telomere repeat array (TRA) reduction was found to significantly correlate with time from diagnosis to acceleration, such that patients with a larger TRA reduction entered the accelerated phase more rapidly (r = -0.50; P =.008). Cox-regression analysis for this group was suggestive of a relationship between a greater TRA-reduction and a shorter time to acceleration (P =.054). Age-adjusted TRA reduction did not significantly affect either the time to blast crisis or overall survival. Our results show that telomere shortening observed at the time of diagnosis in CML significantly influences the time to progress to the accelerated phase. The measurement of diagnostic TRA may prove to be clinically important in the selection of patients at high risk of disease transformation in CML.

Age Factors↗
PubMed2000

CCNU (lomustine), idarubicin and dexamethasone (CIDEX): an effective oral regimen for the treatment of refractory or relapsed myeloma.

We report the results of a non-randomized pilot study of an oral regimen comprising CCNU (lomustine; 25 or 50 mg/m2 on day 1), idarubicin (4-demethoxydaunorubicin) (10 mg/m2 on days 1-3) and dexamethasone (10 mg b.d. on days 1-4) in patients with relapsed or refractory myeloma. Treatment was given every 28 d for a maximum of six courses. Sixty patients were entered of whom 57 were evaluable. Overall response rate (partial or minor response) was 49% with 30% of patients achieving a partial response (50% tumour reduction). Response rates were higher in patients with untested relapse than in those with refractory disease (overall response rates 56% vs. 31%). The major toxicity was neutropenia and the regimen was otherwise well tolerated. The median survival from entry of all patients was 15 months, with 30% of patients alive at 2 years. This regimen represents a useful addition to available treatment options.

Adult↗
PubMed2000

Severe haemolysis after an ABO unmatched kidney transplant - a nonsecretor transplanted from a donor with high anti-A titre.

A case of severe haemolysis following an ABO unmatched renal transplant is reported in a group A nonsecretor who received a kidney from a group O living related donor. Following the haemolytic episode, group A donor units were incompatible and the patient was transfused with group O blood. Serological investigation of the recipient revealed anti-A present in the serum and on the red cells. Investigation of the donor revealed the presence of high-titre anti-A. The association of such high-titre donor antibody with haemolysis in ABO unmatched grafts has not been reported before. We discuss the risk factors for developing haemolysis in an ABO unmatched organ transplant and explore the possible relevance of such high donor antibody titre to recipients who are nonsecretors.

ABO Blood-Group System↗
PubMed2000

Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer.

BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg(-1) over 1 h, followed by a maintenance infusion of 4 mg kg(-1) h(-1) for 5 h. MMC 6 mg m(-2) was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1-4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities--nausea/vomiting and vein pain--were mild and did not exceed CTC grade 2. Liver 31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity.

Adult↗