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William H H Reece

Publications and source records attributed to William H H Reece.

7 recordsLinked to original sources
PubMed2006

Gemcitabine and split-dose paclitaxel or docetaxel in metastatic breast cancer: a randomised phase II study.

PURPOSE: The purpose was to evaluate the activity and toxicity of split-dose paclitaxel or docetaxel in combination with gemcitabine in patients with metastatic breast cancer (MBC) who had previously received anthracyclines. PATIENTS AND METHODS: A total of 210 patients were randomly assigned to one of three treatment arms: gemcitabine 1,250 mg/m(2) Days 1 and 8 and paclitaxel 175 mg/m(2) as a 3-h infusion on Day 1 (GP1); gemcitabine 1,000 mg/m(2) Days 1 and 8 and paclitaxel 100 mg/m(2) as a 1-h infusion on Days 1 and 8 (GP2); gemcitabine 1,000 mg/m(2) Days 1 and 8 and docetaxel 40 mg/m(2) as a 1-h infusion on Days 1 and 8 (GD). Cycles were repeated every 3 weeks. RESULTS: For the 204 patients evaluable for response assessment, the response rates were 48.6% for GP1, 52.2% for GP2, and 52.3% for GD. Median response duration, time to treatment failure, and time to progression (TTP) were similar in each arm. Median TTP for GP1, GP2 and GD was 7.5, 7.0 and 7.4 months, respectively. For the 208 patients evaluable for safety, the most common grade 3/4 toxicity for each regimen was neutropaenia, with 64%, 57%, and 68% for GP1, GP2, and GD, respectively. Grade 4 neutropaenia, grade 3/4 anaemia, febrile neutropaenia, and diarrhoea were more common in the docetaxel arm, as was the use of intravenous antibiotics and blood transfusions. CONCLUSION: The study confirmed the high activity of gemcitabine-taxane combinations in MBC. Split-dose paclitaxel had similar activity and toxicity to the 3-weekly administration. The split-dose docetaxel regimen had similar activity to the paclitaxel combinations though associated with higher toxicity.

Adolescent↗
PubMed2006

Dimorphic Plasmodium falciparum merozoite surface protein-1 epitopes turn off memory T cells and interfere with T cell priming.

The leading blood-stage malaria vaccine candidate antigen, Plasmodium falciparum merozoite surface protein-1 (MSP-1) occurs in two major allelic types worldwide. The molecular basis promoting this stable dimorphism is unknown. In this study, we have shown that allelic altered peptide ligand (APL) T cell epitopes of MSP-1 mutually inhibited IFN-gamma secretion as well as proliferation of CD4+ T cells in 27/34 malaria exposed Gambian volunteers. Besides this inhibition of malaria-specific immunity, the same variant epitopes were also able to impair the priming of human T cells in malaria naive individuals. Epitope variants capable of interfering with T cell priming as well as inhibiting memory T cell effector functions offer a uniquely potent combination for immune evasion. Indeed, enhanced co-habitation of parasites bearing such antagonistic allelic epitope regions was observed in a study of 321 West African children, indicating a survival advantage for parasites able to engage this inhibitory immune interference mechanism.

Adolescent↗
PubMed2004

A CD4(+) T-cell immune response to a conserved epitope in the circumsporozoite protein correlates with protection from natural Plasmodium falciparum infection and disease.

Many human T-cell responses specific for epitopes in Plasmodium falciparum have been described, but none has yet been shown to be predictive of protection against natural malaria infection. Here we report a peptide-specific T-cell assay that is strongly associated with protection of humans in The Gambia, West Africa, from both malaria infection and disease. The assay detects interferon-gamma-secreting CD4(+) T cells specific for a conserved sequence from the circumsporozoite protein, which binds to many human leukocyte antigen (HLA)-DR types. The correlation was observed using a cultured, rather than an ex vivo, ELISPOT assay that measures central memory-'type T cells rather than activated effector T cells. These findings provide direct evidence for a protective role for CD4(+) T cells in humans, and a precise target for the design of improved vaccines against P. falciparum.

Adolescent↗
PubMed2003

Safety and immunogenicity of DNA/modified vaccinia virus ankara malaria vaccination in African adults.

The present study is an investigation of the safety and immunogenicity of DNA and modified vaccinia virus Ankara (MVA) candidate vaccines, each encoding the malaria DNA sequence multiple epitope-thrombospondin related adhesion protein (ME-TRAP), against Plasmodium falciparum. DNA ME-TRAP and MVA ME-TRAP are safe and immunogenic for effector and memory T cell induction. MVA ME-TRAP, with or without prior DNA ME-TRAP immunization, was more immunogenic and more cross-reactive in malaria-exposed individuals than in malaria-naive individuals, a finding suggesting that recombinant MVA vaccines are particularly promising for the development of a malaria vaccine for exposed populations. Both CD4(+) and CD8(+) T cells were induced by these vaccines.

Adult↗
PubMed2003

Enhanced T-cell immunogenicity of plasmid DNA vaccines boosted by recombinant modified vaccinia virus Ankara in humans.

In animals, effective immune responses against malignancies and against several infectious pathogens, including malaria, are mediated by T cells. Here we show that a heterologous prime-boost vaccination regime of DNA either intramuscularly or epidermally, followed by intradermal recombinant modified vaccinia virus Ankara (MVA), induces high frequencies of interferon (IFN)-gamma-secreting, antigen-specific T-cell responses in humans to a pre-erythrocytic malaria antigen, thrombospondin-related adhesion protein (TRAP). These responses are five- to tenfold higher than the T-cell responses induced by the DNA vaccine or recombinant MVA vaccine alone, and produce partial protection manifest as delayed parasitemia after sporozoite challenge with a different strain of Plasmodium falciparum. Such heterologous prime-boost immunization approaches may provide a basis for preventative and therapeutic vaccination in humans.

Animals↗
PubMed2002

Induction of T helper type 1 and 2 responses to 19-kilodalton merozoite surface protein 1 in vaccinated healthy volunteers and adults naturally exposed to malaria.

Plasmodium falciparum malaria is a major cause of death in the tropics. The 19-kDa subunit of P. falciparum merozoite surface protein 1 (MSP-1(19)), a major blood stage vaccine candidate, is the target of cellular and humoral immune responses in animals and humans. In this phase I trial of MSP-1(19), immunization of nonexposed human volunteers with either of the two allelic forms of recombinant MSP-1(19) induced high levels of antigen-specific Th1 (gamma interferon) and Th2 (interleukin 4 [IL-4] and IL-10) type lymphokines. The adjustment of the antigen dose and number of immunizations regulated the level of specificity of immune responses and Th1/Th2 bias of responses induced by vaccination. Novel conserved and allelic T-cell epitopes which induced cross-strain immune responses were identified. Importantly, responses to many of these novel epitopes were also present in adults exposed to malaria, both in east (Kenya) and west Africa (The Gambia). These data suggest that epitope-specific naturally acquired MSP-1(19) immune responses in endemic populations can be boosted by vaccination.

Adolescent↗