204 research outputs found

    Diagnostics for generalized linear models

    Get PDF
    The analysis of residuals can capture departures from a parametrized model. In this thesis we look at how the generalized linear model has become one of the most important developments in statistics in the last thirty years, and on the adequacy of regression model diagnostics that are meaningful and significant in a generalized linear model context. Some asymptotic properties are discussed and numerical examples are provided to illustrate the techniques for binomial, Poisson, and gamma distributed random variables

    Palmar-plantar erythrodysesthesia secondary to docetaxel chemotherapy: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Docetaxel is a chemotherapeutic agent used alone or in combination for the management of many neoplastic conditions. Numerous side effects are well described as a consequence. Palmar-plantar erythrodysesthesia, although a relatively common side effect of some types of chemotherapy, occurs infrequently with docetaxel and is often attributed to other drug agents.</p> <p>Case Presentation</p> <p>We report the case of a 66-year-old Caucasian woman who received adjuvant docetaxel monotherapy for invasive breast cancer. She developed palmar-plantar erythrodysesthesia following her first cycle of treatment, which necessitated a change in management.</p> <p>Conclusion</p> <p>Palmar-plantar erythrodysesthesia is a relatively common side effect of cytotoxic chemotherapy, particularly with drugs such as 5-fluorouracil, capecitabine and liposomal doxorubicin. Docetaxel is commonly used both alone and in combination with a number of these agents for the management of various malignant conditions. We would like to highlight the occurrence of palmar-plantar erythrodysesthesia as a result of docetaxel monotherapy so that it can be considered as a potential cause in patients receiving combination treatment with chemotherapeutic agents better known to cause this toxicity.</p

    Revised Modelling of the Addition of Synchronous Chemotherapy to Radiotherapy in Squamous Cell Carcinoma of the Head and Neck-A Low ?

    Get PDF
    Background: The effect of synchronous chemotherapy in squamous cell carcinoma of the head and neck (SCCHN) has been modelled as additional Biologically Effective Dose (BED) or as a prolonged tumour cell turnover time during accelerated repopulation. Such models may not accurately predict the local control seen when hypofractionated accelerated radiotherapy is used with synchronous chemotherapy. Methods: For the purposes of this study three isoeffect relationships were assumed: Firstly, from the RTOG 0129 trial, synchronous cisplatin chemotherapy with 70 Gy in 35 fractions over 46 days results in equivalent local control to synchronous cisplatin chemotherapy with 36 Gy in 18# followed by 36 Gy in 24# (2# per day) over a total of 39 days. Secondly, in line with primary local control outcomes from the PET-Neck study, synchronous cisplatin chemotherapy with 70 Gy in 35# over 46 days results in equivalent local control to synchronous cisplatin chemotherapy delivered with 65 Gy in 30# over 39 days. Thirdly, from meta-analysis data, 70 Gy in 35# over 46 days with synchronous cisplatin results in equivalent local control to 84 Gy in 70# over 46 days delivered without synchronous chemotherapy. Using the linear quadratic equation the above isoeffect relationships were expressed algebraically to determine values of &alpha;, &alpha;/&beta;, and k for SCCHN when treated with synchronous cisplatin using standard parameters for the radiotherapy alone schedule (&alpha; = 0.3 Gy&minus;1, &alpha;/&beta; = 10 Gy, and k = 0.42 Gy10day&minus;1). Results: The values derived for &alpha;/&beta;, &alpha; and k were 2 Gy, 0.20 and 0.21 Gy&minus;1, and 0.65 and 0.71 Gy2day&minus;1. Conclusions: Within the limitations of the assumptions made, this model suggests that accelerated repopulation may remain a significant factor when synchronous chemotherapy is delivered with radiotherapy in SCCHN. The finding of a low &alpha;/&beta; for SCCHN treated with cisplatin suggests a greater tumour susceptibility to increasing dose per fraction and underlines the importance of the completion of randomized trials examining the role of hypofractionated acceleration in SCCHN

    Practical management of Chronic Myeloid Leukemia in Belgium

    Full text link
    peer reviewedImatinib has drastically changed the outcome of patients with chronic myeloid leukemia (CML), with the majority of them showing a normal life span. Recently, the development of second and third generation tyrosine kinase inhibitors (TKIs) and the possibility of treatment discontinuation made the management of these patients more challenging. In this review, practical management guidelines of CML are presented, adapted to the Belgian situation in 2014. In first line chronic phase patients, imatinib, nilotinib and dasatinib can be prescribed. While second generation TKIs give faster and deeper responses, their impact on long-term survival remain to be determined. The choice of the TKI depends on CML risk score, priority for a deep response to allow a treatment-free remission protocol, age, presence of comorbid conditions, side effect profile, drug interactions, compliance concerns and price. Monitoring the response has to be made according the 2013 ELN criteria, and is based on the bone-marrow cytogenetic response during the first months and on the blood molecular response. Molecular follow-up is sufficient in patients with a complete cytogenetic response. For patients who fail frontline therapy, nilotinib, dasatinib, bosutinib and ponatinib are an option depending of the type of intolerance or resistance. T315I patients are only sensitive to ponatinib, which has to be carefully handled due to cardiovascular toxicity. Advanced phase diseases are more difficult to handle, with treatments including allogeneic stem cell transplantation, which is also an option for patients failing at least two TKIs. The possibility of treatment-free remission and pregnancy are also discussed

    Control of the allogeneic reaction by naturally occuring regulatory T cells

    No full text
    Le polymorphisme et le polygĂ©nisme des complexes majeurs d’histocompatibilitĂ© (CMH) limitent les succĂšs de la transplantation. En effet, les disparitĂ©s, tant d’antigĂšnes mineurs que majeurs, exposent le patient transplantĂ© au risque de rejet et imposent l’administration d’un traitement immunosuppresseur. Ce dernier affecte de façon non spĂ©cifique l’ensemble des rĂ©ponses immunitaires et augmente le risque d’infections mortelles et de cancers. En outre, ce traitement ne semble pas prĂ©venir le rejet chronique. Des dĂ©couvertes rĂ©centes ont confirmĂ© l’existence de lymphocytes appelĂ©s rĂ©gulateurs (Tregs) dont le rĂŽle est de garantir l’homĂ©ostasie des rĂ©ponses immunes afin qu’elles ne deviennent incontrĂŽlĂ©es et pathologiques. Les Tregs classiquement dĂ©crits expriment de maniĂšre constitutive l’antigĂšne CD4+, la chaĂźne alpha du rĂ©cepteur de l’interleukine (IL)-2 (CD25) et le facteur de transcription Foxp3. Ils reprĂ©sentent 5 Ă  10% des lymphocytes CD4+ totaux. Les Tregs sont capables de rĂ©guler des lymphocytes allorĂ©actifs et ont Ă©tĂ© dĂ©crits comme responsables du maintien de la tolĂ©rance d’allogreffe chez la souris. Mais jusqu'alors, les modĂšles employĂ©s pour dĂ©montrer l'importance des Tregs en transplantation utilisaient soit un traitement immunosuppresseur transitoire, soit des transferts de cellules T dans des souris lymphopĂ©niques. Toutefois, ces derniers ne permettent pas de distinguer l'effet des Tregs sur la prolifĂ©ration homĂ©ostatique des lymphocytes effecteurs de leur effet sur la rĂ©ponse allogĂ©nique.Dans notre travail, nous montrons que les Tregs jouent un rĂŽle prĂ©pondĂ©rant dans l’acceptation spontanĂ©e d’allogreffes en l’absence d’immunosuppresseur et en dehors d’un contexte lymphopĂ©nique chez la souris. En effet, la dĂ©plĂ©tion des Tregs du receveur par l’administration d’anticorps anti CD25 amplifie les rĂ©ponses allogĂ©niques de type Th1 et Th2 et, par consĂ©quent, dĂ©clenche le rejet d’allogreffe. Les propriĂ©tĂ©s rĂ©gulatrices des Tregs ne sont cependant pas illimitĂ©es. En effet, dans un second travail, nous dĂ©crivons, d’une part, leur incapacitĂ© Ă  contrĂŽler la production d’IL-17 par des lymphocytes CD4+CD25pos mĂ©moires et, d’autre, part leur implication directe dans la diffĂ©renciation de cellules Th17 au dĂ©part de lymphocytes CD4+CD25neg allorĂ©actifs.Nous concluons donc que si les Tregs naturellement prĂ©sents chez le receveur jouent un rĂŽle primordial dans la protection du greffon contre des rĂ©ponses de type Th1 ou Th2, ils pourraient nĂ©anmoins favoriser une voie alterne du rejet d’allogreffe dĂ©pendante de l’IL 17./Major histocompatibility complex (MHC) polymorphism is a major hindrance to transplantation success. Both minor and major antigen disparities between donor and recipient increase the risk of transplant rejection. This is thwarted by the administration of an immunosuppressive therapy that unspecifically affects all immune responses therefore increasing the risk of infections and cancers. Besides, this treatment does not seem to prevent chronic rejection.Recent studies have confirmed the existence of lymphocytes called regulatory T cells (Tregs), whose role is to maintain the general immune homeostasis and to protect the individual from autoimmune diseases.The classically described Tregs express constitutively the CD4 antigen, the alpha chain of the interleukin (IL)-2 receptor (CD25) and the transcription factor Foxp3. They represent 5 to 10% of total CD4+ T cells. Tregs are able to control alloreactive responses and were described to be responsible for the maintenance of allograft tolerance in mice. So far, the tolerogenic capacities of Tregs have been demonstrated either in mice treated with immunomodulatory antibodies (induced Tregs) or by adoptive co-transfer of Tregs and effector cells into lymphopenic mice. However, the latter has the disadvantage of not being able to distinguish the effect of Treg on lymphopenia-induced homeostatic proliferation from their effect on alloreactive responses. Herein, we show that Tregs play a crucial role in spontaneously accepted allografts in the absence of immunosuppressive therapy and in non-lymphopenic condition. Indeed, the depletion of the recipient’s Tregs through the administration of an anti-CD25 antibody enhances type Th1 and type-Th2 allogeneic responses, consequently triggering allograft rejection. However, the regulatory properties of Tregs are not unlimited. Indeed, we found that Tregs are unable to control allogeneic IL-17 production by memory CD4+ T cells and are even necessary for de novo Th17 differentiation. We conclude, therefore, that Tregs naturally present in the recipient play a critical role in protecting the allograft. Nevertheless, despite this context of regulation, IL-17-producing alloreactive T cells, beyond the control of Tregs, could mediate an alternative pathway of allograft rejection.Doctorat en Sciences mĂ©dicalesinfo:eu-repo/semantics/nonPublishe
    • 

    corecore