17 research outputs found

    Molecular Pathogenesis of EBV Susceptibility in XLP as Revealed by Analysis of Female Carriers with Heterozygous Expression of SAP

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    X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency caused by mutations in SH2D1A which encodes SAP. SAP functions in signalling pathways elicited by the SLAM family of leukocyte receptors. A defining feature of XLP is exquisite sensitivity to infection with EBV, a B-lymphotropic virus, but not other viruses. Although previous studies have identified defects in lymphocytes from XLP patients, the unique role of SAP in controlling EBV infection remains unresolved. We describe a novel approach to this question using female XLP carriers who, due to random X-inactivation, contain both SAP+ and SAP− cells. This represents the human equivalent of a mixed bone marrow chimera in mice. While memory CD8+ T cells specific for CMV and influenza were distributed across SAP+ and SAP− populations, EBV-specific cells were exclusively SAP+. The preferential recruitment of SAP+ cells by EBV reflected the tropism of EBV for B cells, and the requirement for SAP expression in CD8+ T cells for them to respond to Ag-presentation by B cells, but not other cell types. The inability of SAP− clones to respond to Ag-presenting B cells was overcome by blocking the SLAM receptors NTB-A and 2B4, while ectopic expression of NTB-A on fibroblasts inhibited cytotoxicity of SAP− CD8+ T cells, thereby demonstrating that SLAM receptors acquire inhibitory function in the absence of SAP. The innovative XLP carrier model allowed us to unravel the mechanisms underlying the unique susceptibility of XLP patients to EBV infection in the absence of a relevant animal model. We found that this reflected the nature of the Ag-presenting cell, rather than EBV itself. Our data also identified a pathological signalling pathway that could be targeted to treat patients with severe EBV infection. This system may allow the study of other human diseases where heterozygous gene expression from random X-chromosome inactivation can be exploited

    Axial substitution and electron transfer reactions of ferriporphyrins

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    Includes bibliographical references (pages 53-56)Section I: Spectrophotometric titrations were used to determine the composite equilibrium quotient 4 x 104 M-2 in neutral and slightly basic media for axial histidine binding to the water soluble ferriporphyrin, ??, ??, ??, ?? -tetra(4-N-methylpyridyl) porphineiron(III). The coordination number of the axial site of hemin iron was determined to be 2.0, indicating that the resulting major complexes are six-coordinate bis(histidine) hemichromes. The magnetic moment in solution (Evans's method) was found to be 2 .18 ?? 0.04 B. M. at. 34 ??C. The kinetics of the ascorbic acid reduction of the bis(histidine) ferriporphyrin has been studied by stopped-f1ow spectrophotometry. At 25.0??C, ?? = 0.10(NaCl) and pH ranging from 6.6 to 8.8, the reduction of the bis(histidine) ferriporphyrin follows a pseudo-first-order rate expression in excess ascorbic acid. (See more in text.

    Predatory Invitations from Journals: More Than Just a Nuisance?

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    Physicians and academic researchers are frequently targeted with spam invitations to submit manuscripts to predatory journals. This study was conducted to understand the nature and characteristics of these invitations. All spam e‐mails received by an academic medical oncologist over a 3‐month period were collected and categorized. Presumed predatory journal invitations were analyzed and cross‐checked against Beall's list of “potential, probable, or possible predatory” journals and publishers. Invitations to submit to predatory journals were the most common single type of spam received

    Randomised feasibility trial to compare three standard of care chemotherapy regimens for early stage triple-negative breast cancer (REaCT-TNBC trial)

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    <div><p>Introduction</p><p>Despite the importance of chemotherapy in the treatment of early stage triple negative breast cancer (TNBC), no one optimal regimen has been identified. We conducted a pilot trial comparing outcomes for the three most commonly used chemotherapy regimens to assess the feasibility of conducting a larger definitive trial.</p><p>Methods</p><p>Using integrated consent, newly diagnosed TNBC patients were randomised to one of three standard regimens: dose-dense doxorubicin-cyclophosphamide then paclitaxel, doxorubicin-cyclophosphamide then weekly paclitaxel or 5-FU-epirubicin-cyclophosphamide then docetaxel. Feasibility endpoints included; physician engagement, accrual rates, physician compliance and patient satisfaction with the integrated consent model. Our anticipated pilot trial sample size was 35 randomised patients in one year.</p><p>Results</p><p>Between August 30<sup>th</sup>, 2016 and January 31<sup>st</sup> 2017, 2 patients met eligibility and were randomised. A survey of 10 participating oncologists was performed to identify potential strategies to enhance accrual. Most investigators (9/10) believed that the best regimen for TNBC was unknown, and 4/10 felt this was a pressing clinical question. Physicians’ responses suggested that poor accrual was due to: a lack of interest in some study arms as oncologists already had a preferred regimen (4/10) and concerns about trial demands in busy clinics (3/10). The pilot feasibility endpoints were not met and the study was closed.</p><p>Conclusions</p><p>Despite initial interest in the trial question and multiple investigators agreeing to approach patients, this trial failed to meet feasibility endpoints. The reasons for poor accrual were multiple and require further evaluation if this important patient-centred question is to be answered.</p><p>Trial registration</p><p>ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02688803" target="_blank">NCT02688803</a>.</p></div

    A Multi-Centre Randomized Study Comparing Two Standard of Care Chemotherapy Regimens for Lower-Risk HER2-Positive Breast Cancer

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    Background: Neither paclitaxel plus trastuzumab (P-H) nor docetaxel-cyclophosphamide plus trastuzumab (TC-H) have been prospectively compared in HER2-positive early-stage breast cancer (EBC). A randomized trial was performed to assess the feasibility of a larger study. Methods: Lower-risk HER2-positive EBC patients were randomized to either P-H or TC-H treatment arms. The co-primary feasibility outcomes were: ≥75% patient acceptability rate, active trial participation of ≥50% of medical oncologists, ≥75% and ≥90% treatment completion, and receipt rate of planned cycles of chemotherapy, respectively. Secondary outcomes: Febrile neutropenia (FN) rate, treatment-related hospitalizations, health-related quality of life (HR-QoL) questionnaires. Analyses were performed by per protocol and intention-to-treat. Results: Between May 2019 and March 2021, 49 of 52 patients agreed to study participation (94% acceptability rate). Fifteen (65%) of 23 medical oncologists approached patients. Rates of FN were higher (8.3% vs. 0%) in the TC-H vs. P-H arm. Median (IQR) changes in scores from baseline in FACT-Taxane Trial Outcome Index at 24 weeks were −4 (−10, −1) vs. −6.5 (−15, −2) for TC-H and P-H arms, respectively. Conclusions: A randomized trial comparing P-H and TC-H was feasible. Expansion to a larger trial would be feasible to explore patient-reported outcomes of these adjuvant HER2 chemotherapy regimens

    Primary Febrile Neutropenia Prophylaxis for Patients Who Receive FEC-D Chemotherapy for Breast Cancer: A Systematic Review

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    Purpose: Despite widespread use of fluorouracil, epirubicin, cyclophosphamide, docetaxel (FEC-D) chemotherapy in breast cancer, the optimal strategy for primary febrile neutropenia (FN) prophylaxis remains unknown. A systematic review was therefore performed. Methods: Embase, Ovid MEDLINE, PubMed, Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials, and conference proceedings were searched from 1946 to April 2016 for trials that reported the effectiveness of primary FN prophylaxis with FEC-D chemotherapy. Outcome measures were incidence of FN; treatment-related hospitalizations; chemotherapy dose delays, reductions, and discontinuations; and adverse events from prophylaxis. Results: Of 2,205 identified citations, eight studies (n = 1,250) met our eligibility criteria. Three additional studies (n = 293) were identified from a prior systematic review. Three randomized controlled trials (n = 576), one phase IV single-arm trial (n = 69), one prospective observational study (n = 37), and six retrospective studies (n = 861) were identified. Agents investigated were pegfilgrastim (n = 108), filgrastim (n = 1,119), and ciprofloxacin (n = 89). The heterogeneity of studies meant that a narrative synthesis of results was performed. Median FN rates for patients who received FEC-D with and without primary prophylaxis were 10.1% (interquartile range [IQR], 3.9% to 22.6%) and 23.9% (IQR, 9.2% to 27.3%), respectively. In the absence of primary prophylaxis, FN was more common during docetaxel than during FEC. Data from six studies showed a median rate of dose reductions and delays of 6.1% (IQR, 3.1% to 14.3%) and 19.3% (IQR, 10.5% to 32.8%), respectively, that occurred as a consequence of FN. Toxicity from prophylaxis itself was rarely reported. Conclusion: Primary FN prophylaxis is effective in patients who receive FEC-D chemotherapy. The paucity of prospective data makes optimal recommendations about the choice and timing of prophylaxis challenging

    Optimising weight-loss interventions in cancer patients-A systematic review and network meta-analysis.

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    BackgroundExcess weight has been associated with increased morbidity and a worse prognosis in adult patients with early-stage cancer. The optimal lifestyle interventions to optimize anthropometric measures amongst cancer patients and survivors remain inconsistent.ObjectiveTo conduct a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the effects of exercise and dietary interventions alone or in combination on anthropometric measures of adult cancer patients and survivors.MethodsA systematic search of Medline, Embase and the Cochrane Trials Registry was performed. Outcomes of interest included changes in weight, body mass index (BMI), and waist circumference. Screening and data collection were performed by two reviewers. Bayesian NMAs were performed.ResultsOverall, 98 RCTs were included; 75 were incorporated in NMAs (n = 12,199). Groups of intervention strategies included: 3 exercise interventions, 8 dietary interventions, 7 combination interventions of diet and exercise and standard care. Median intervention duration was 26 weeks. NMA suggested that diet alone (mean difference [MD] -2.25kg, 95% CrI -3.43 to -0.91kg) and combination strategies (MD -2.52kg, 95% CrI -3.54 to -1.62kg) were associated with more weight loss compared to standard care. All dietary interventions achieved a similar magnitude of weight loss (MD range from -2.03kg to -2.52kg). Both diet alone and combination strategies demonstrated greater BMI reductions versus standard care, and each of diet alone, exercise alone and combination strategies demonstrated greater reductions in waist circumference than standard care.ConclusionDiet and exercise alone or in combination are effective lifestyle interventions to improve anthropometric measures in cancer patients and survivors. All reputable diets appear to be similarly effective to achieve weight loss

    A Randomized Trial Comparing 3- versus 4-Monthly Cardiac Monitoring in Patients Receiving Trastuzumab-Based Chemotherapy for Early Breast Cancer

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    Purpose: The optimal frequency for cardiac monitoring of left ventricular ejection fraction (LVEF) in patients receiving trastuzumab-based therapy for early breast cancer (EBC) is unknown. We conducted a randomized controlled trial comparing 3- versus 4-monthly cardiac monitoring. Patients and Method: Patients scheduled to receive trastuzumab-containing cancer therapy for EBC with normal (&gt;53%) baseline LVEF were randomized to undergo LVEF assessments every 3 or 4 months. The primary outcome was the change in LVEF from baseline. Secondary outcomes included the rate of cardiac dysfunction (defined as a decrease in the LVEF of &ge;10 percentage points, to a value &lt;53%), delays in or discontinuation of trastuzumab therapy, and cardiology referral. Results: Of the 200 eligible and enrolled patients, 100 (50%) were randomized to 3-monthly and 100 (50%) to 4-monthly cardiac monitoring. Of these patients, 98 and 97 respectively underwent at least one cardiac scan. The estimated mean difference in LVEF from baseline was &minus;0.94% (one-sided 95% lower bound: &minus;2.14), which exceeded the pre-defined non-inferiority margin of &minus;4%. There were also no significant differences between the two study arms for any of the secondary endpoints. The rate of detection of cardiac dysfunction was 16.3% (16/98) and 12.4% (12/97) in the 3- and 4-monthly arms, respectively (95% CI: 4.0 [&minus;5.9, 13.8]). Conclusions: Cardiac monitoring every 4 months was deemed non-inferior to that every 3 months in patients with HER2-positive EBC being treated with trastuzumab-based therapy. Given its costs and inconvenience, cardiac monitoring every 4 months should be considered standard practice. Registration: NCT02696707, 18 February 2016
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