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Biomedical subjects

P Ellis

Publications and source records attributed to P Ellis.

At least 19 recordsLinked to original sources
PubMed2006

Towards optimal endocrine therapy for hormone-sensitive breast cancer: initial versus sequential adjuvant aromatase inhibition.

Patients with hormone-receptor-positive early breast cancer have a significant risk of recurrence despite the use of adjuvant tamoxifen. The third-generation aromatase inhibitors letrozole, anastrozole, and exemestane offer promise as alternative or additional therapy to tamoxifen. As extended adjuvant therapy following completion of 5 years of tamoxifen, letrozole further decreased the risk of recurrence compared with placebo. Compared with tamoxifen, both letrozole and anastrozole significantly reduced the risk of recurrence when used as initial adjuvant therapy, and in the short term both were better tolerated than tamoxifen. Anastrozole and exemestane both reduced the risk of relapse when started after 2-3 years of tamoxifen compared with continued tamoxifen treatment; the results of letrozole in this setting are expected in 2008. These data establish adjuvant aromatase inhibitors as effective alternatives to tamoxifen. Only limited data are currently available to inform the choice between an aromatase inhibitor as either initial adjuvant therapy or sequentially after tamoxifen. Future results from the Breast International Group (BIG) 1-98 trial will further clarify strategies for the adjuvant use of aromatase inhibitors. Here, we critically review the evidence for adjuvant use of aromatase inhibitors. Comparison is made between initial aromatase inhibition, switching, and extended adjuvant strategies. Practical recommendations are given for the endocrine treatment of post-menopausal breast cancer.

Antineoplastic Agents, Hormonal↗
PubMed2006

Microbiological quality of randomly selected ready-to-eat foods sampled between 2003 and 2005 in Wales, UK.

Since 1995, the publicly funded ready-to-eat food sampling and examination activities in Wales have been coordinated and structured, using a novel approach for the identification of samples and premises. The latest set of data from this surveillance system reports the results from 3391 ready-to-eat foods sampled between November 2003 and March 2005. During this seventeen-month period all samples were examined for aerobic colony count, Escherichia coli, Listeria spp., Bacillus cereus, Salmonella, Staphylococcus aureus and Listeria monocytogenes. The food types with the poorest microbiological quality were cream cakes, custard slices and egg mayonnaise sandwiches. The food type with the best microbiological quality was dried fruit. In conclusion, the results indicate that, in general terms, the ready-to-eat food types sampled and examined in this period posed little bacterial hazard to consumers.

Bacillus cereus↗
PubMed2005

Fast recruiting clinical trials--a utopian dream or logistical nightmare?

Randomised clinical trials that exceed anticipated recruitment rates will by definition have the necessary precision to answer the research question within the expected time, thus ensuring the timely release of data that will inform future clinical practice. In addition, the national or international momentum generated brings with it a collective sense of achievement. Such trials, however, may also identify logistical and scientific problems that researchers should be aware of and for which provision needs to be made. The logistical problems relate to the rapid identification of the extra resources required to allow continued excellence in day-to-day management and monitoring of trial governance (both in participating centres and in coordinating trials units). The scientific/clinical problems include managing issues such as unexpected toxicities and suboptimal compliance, and the lack of time available in a rapidly recruiting trial to address them. A related issue concerns the lack of time available to initiate substudies (e.g. biological substudies), the relevance of which may only become apparent as the trial progresses. Many of these challenges were highlighted by recent experience with the Cancer Research UK Taxotere as Adjuvant Chemotherapy trial.

Clinical Trials as Topic↗
PubMed2005

Multiple risk behaviour and its association with head and neck injuries: a national analysis of young Canadians.

BACKGROUND: Among adolescents, risk behaviors often cluster together and lead to risk behaviour syndromes. Multiple risk behaviors in turn become important determinants of health outcomes, including injuries. METHODS: A national sample (n = 11,415) of Canadian youth aged 11-15 years was examined from the 1997-1998 Health Behaviour in School-Aged Children Survey. Principal components analyses were used to characterize how adolescent risk behaviors cluster together into factors. Associations between these behavioral factors and injury outcomes were explored via multiple logistic regression analyses. RESULTS: Two factors of risk behaviors emerged: lifestyle risks and psychological risks. Strong associations between the lifestyle risk scale and the occurrence of head and neck injuries were identified (P < 0.001 for trend). The relative odds for the highest quintile versus the lowest quintile were 6.96 (95% CI: 3.95-12.26). Similar injury risks were not identified in association with the psychological risk scale. CONCLUSIONS: The findings provide novel information about potential causes of injury to young people and provide a reliable method by which researchers can quantify two determinants of health. These are helpful for injury control research in that they provided a means by which health risk behaviors can be measured and then related to the injury experiences of young people.

Adolescent↗
PubMed2005

Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification.

AIM: To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair. MATERIALS AND METHODS: Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD. RESULTS: Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05). CONCLUSION: This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.

Aged↗
PubMed2004

Seeking informed consent to cancer clinical trials: describing current practice.

Clinical trials have come to be regarded as the gold standard for treatment evaluation. However, many doctors and their patients experience difficulties when discussing trials, leading to poor accrual to trials and questionable quality of informed consent. We have previously developed a typology for ethical communication about Phase II and III clinical trials within four domains: (a) shared decision making, (b) sequencing information, (c) type and clarity of information, and (d) disclosure/coercion. The aim of this study was to compare current clinical practice when seeking informed consent with this typology. Fifty-nine consultations in which 10 participating oncologists sought informed consent were audiotaped. Verbatim transcripts were analysed using a coding system to (a) identify the presence or absence of aspects of the four domains and (b) rate the quality of aspects of two domains: (i) shared decision-making and (ii) type and clarity of information. Oncologists rarely addressed aspects of shared decision-making, other than offering to delay a treatment decision (78%). Moreover, many of these discussions scored poorly with respect to ideal content. The oncologists were rarely consistent with the sequence of information provision. A general rationale for randomising was only described in 46% of consultations. In almost one third of the consultations (28.8%) doctors made implicit statements favouring one option over another, either standard or clinical trial treatment. Doctors complied with some but not other aspects of a standard procedure for discussing clinical trials. This reflects the difficulty inherent in seeking ethical informed consent and the need for communication skills training for oncologists.

Adult↗
PubMed2004

The effect of hemopure on coagulation in clinically relevant concentrations.

Hemopure is a new colloidal blood substitute that may influence coagulation. We designed this study to examine the influence of this product on in vitro coagulation of whole blood by using the thrombelastograph (TEG). Blood samples from 20 volunteers were obtained. Hemopure was added to blood samples to obtain 0.5, 1, and 2 g/dL mixtures of Hemopure in blood. Control consisted of an undiluted sample and, for comparison, two samples diluted with volumes of lactated Ringer's solution (LR) equivalent to the two higher Hemopure dilutions. TEG with Hemopure at a concentration of 2 g/dL showed significantly shorter reaction and clot formation k times and an increased alpha angle compared with control. LR dilution with equivalent volume to 2 g/dL Hemopure solution also resulted in significantly shorter reaction and k times, as well as an increased alpha angle. Coagulation in samples with Hemopure at concentrations of 0.5 and 1 mg/dL did not vary significantly from control. Maximum amplitude did not vary significantly from control in any samples. The effect of Hemopure on TEG measures of coagulation is not significantly different from that of LR at clinically relevant concentrations.

Blood Circulation Time↗
PubMed2002

Comparison of the compact dry TC and 3M petrifilm ACP dry sheet media methods with the spiral plate method for the examination of randomly selected foods for obtaining aerobic colony counts.

Two hundred thirty-six randomly selected food and milk samples were examined to obtain aerobic colony counts by two dry sheet media methods and a standard Public Health Laboratory Service spiral plate method. Results for 40 samples were outside the limits of detection for one or more of the tested methods and were not considered. (The limits of detection for the spiral plate method were 200 to 1 x 10(8) CFU/ml for the spiral plate method and 100 to 3 x 10(6) CFU/ml for the dry sheet media methods.) The remaining 196 sets of results were analyzed further. When the results from the three methods were compared, correlation coefficients were all >0.80 and slopes and intercepts were close to 1.0 and 0.0, respectively. Mean log values and standard deviations were very similar for all three methods. The results were evaluated according to published UK guidelines for ready-to-eat foods sampled at the point of sale, which include a quality acceptability assessment that is based on aerobic colony counts. Eighty-six percent of the comparable results gave the same verdict with regard to acceptability according to the aerobic colony count guidelines. Both dry sheet media methods were comparable to the spiral plate method and can be recommended for the examination of food.

Animals↗
PubMed2001

MAD phasing with krypton.

Experiments demonstrating the feasibility of Kr-edge MAD on frozen crystals as a routine method for structure determination are reported. Approximately 50% of protein crystals can be successfully derivatized by pressurization with the noble gases xenon or krypton. While Xe has produced many useful derivatives for MIR phasing over the last several years, the Xe edges (K edge = 34.6 keV, L(I) = 5.5 keV) are not easily accessible for MAD studies. As the Kr K edge (14.3 keV) is accessible on most MAD beamlines, Kr derivatization provides the additional opportunity to conduct a MAD experiment and obtain phases using only a single crystal. This paper describes the phasing of two proteins using Kr MAD: the 17 kDa Fe protein myoglobin (Mb) from sperm whale (Physeter catodon) and an 18 kDa protein (SP18) from green abalone (Haliotis fulgens). Three-wavelength data were collected at SSRL beamline 9-2 from crystals of Mb and SP18 incubated in 2.76 MPa of Kr gas for 2 min, depressurized and then flash-frozen in a stream of nitrogen gas at 100 K. MAD phases were calculated using the program SHARP and the resulting density improved with wARP. The final maps for both Mb and SP18 were of excellent quality.

Animals↗
PubMed2001

Screening for renal disease: the role of the practice nurse.

Screening tests for renal disease are inexpensive, easy to carry out and simple to interpret. Nurses in general practice can provide screening for high-risk populations and interpret the results of these tests. Practice nurses can also provide patient information about renal disease, which will both improve patients' quality of life and save time and money for the NHS.

Humans↗
PubMed2000

Molecular analysis of phyllodes tumors reveals distinct changes in the epithelial and stromal components.

Phyllodes tumors are fibroepithelial mammary lesions that tend to behave in a benign fashion but may undergo sarcomatous transformation. A study of clonality in these tumors has suggested that the epithelial component is polyclonal, but the stroma is monoclonal, and thus forms the neoplastic component of the lesion. In this study microsatellites on chromosome 1q and chromosome 3p were assessed for allelic imbalance (AI) in 47 phyllodes tumors; in all cases stroma and epithelium were analyzed separately. Ten of 42 (24%) phyllodes tumors showed AI at one or more markers on 3p, and 14 of 46 (30%) showed AI on chromosome 1. Five tumors had changes in both the epithelium and stroma. Eight tumors had changes only detectable in the stroma and eight, changes in the epithelium only. Three tumors exhibited low-level microsatellite instability in the epithelium but not in the stroma. The results show that AI on 3p and 1q does occur in phyllodes tumors and that it can occur in both the stroma and epithelium, sometimes as independent genetic events. These unexpected findings throw into doubt the classical view that phyllodes tumors are simply stromal neoplasms and raise questions about the nature of stromal and epithelial interactions in these tumors.

Alleles↗
PubMed2000

Dendritic cells permit identification of genes encoding MHC class II-restricted epitopes of transplantation antigens.

Minor or histocompatibility (H) antigens are recognized by CD4+ and CD8+ T lymphocytes as short polymorphic peptides associated with MHC molecules. They are the targets of graft versus host and graft versus leukemia responses following bone marrow transplantation between HLA-identical siblings. Several genes encoding class I-restricted minor H epitopes have been identified, but approaches used for these have proved difficult to adapt for cloning class II-restricted minor H genes. We have combined the unique antigen-presenting properties of dendritic cells and high levels of episomal expression following transfection of COS cells to identify a Y chromosome gene encoding two HY peptide epitopes, HYAb and HYEk.

Amino Acid Sequence↗
PubMed2000

Using telephone prompts to improve initial attendance at a community mental health center.

Contacting patients by telephone before their appointment has been shown to increase clinic attendance in various settings. However, no such studies have been conducted in New Zealand, which has a unique mix of publicly funded secondary care and largely privately funded primary care. A controlled prospective study of telephone prompting was carried out in a New Zealand publicly funded community mental health center. One group of 190 patients was phoned the day before their initial appointment, and their attendance rate was compared with that of 496 patients not phoned. Ninety-six percent of the patients who were successfully contacted kept their appointment, compared with 76 percent of those not contacted.

Adolescent↗