880 research outputs found
Cisplatin and fluorouracil with or without panitumumab in patients with recurrent or metastatic squamous-cell carcinoma of the head and neck (SPECTRUM): an open-label phase 3 randomised trial
Background: Previous trials have shown that anti-EGFR monoclonal antibodies can improve clinical outcomes of patients with recurrent or metastatic squamous-cell carcinoma of the head and neck (SCCHN). We assessed the efficacy and safety of panitumumab combined with cisplatin and fluorouracil as first-line treatment for these patients.
Methods: This open-label phase 3 randomised trial was done at 126 sites in 26 countries. Eligible patients were aged at least 18 years; had histologically or cytologically confi rmed SCCHN; had distant metastatic or locoregionally recurrent disease, or both, that was deemed to be incurable by surgery or radiotherapy; had an Eastern Cooperative Oncology Group performance status of 1 or less; and had adequate haematological, renal, hepatic, and cardiac function. Patients were randomly assigned according to a computer-generated randomisation sequence (1:1; stratifi ed by previous treatment, primary tumour site, and performance status) to one of two groups. Patients in both groups received up to six 3-week cycles of intravenous cisplatin (100 mg/m(2) on day 1 of each cycle) and fl uorouracil (1000 mg/m(2) on days 1-4 of each cycle); those in the experimental group also received intravenous panitumumab (9 mg/kg on day 1 of each cycle). Patients in the experimental group could choose to continue maintenance panitumumab every 3 weeks. The primary endpoint was overall survival and was analysed by intention to treat. In a prospectively defi ned retrospective analysis, we assessed tumour human papillomavirus (HPV) status as a potential predictive biomarker of outcomes with a validated p16-INK4A (henceforth, p16) immunohistochemical assay. Patients and investigators were aware of group assignment; study statisticians were masked until primary analysis; and the central laboratory assessing p16 status was masked to identifi cation of patients and treatment. This trial is registered with ClinicalTrials. gov, number NCT00460265.
Findings: Between May 15, 2007, and March 10, 2009, we randomly assigned 657 patients: 327 to the panitumumab group and 330 to the control group. Median overall survival was 11.1 months (95% CI 9.8-12.2) in the panitumumab group and 9.0 months (8.1-11.2) in the control group (hazard ratio [HR] 0.873, 95% CI 0.729-1.046; p = 0.1403). Median progression-free survival was 5.8 months (95% CI 5.6-6.6) in the panitumumab group and 4.6 months (4.1-5.4) in the control group (HR 0.780, 95% CI 0.659-0.922; p = 0.0036). Several grade 3 or 4 adverse events were more frequent in the panitumumab group than in the control group: skin or eye toxicity (62 [19%] of 325 included in safety analyses vs six [2%] of 325), diarrhoea (15 [5%] vs four [1%]), hypomagnesaemia (40 [12%] vs 12 [4%]), hypokalaemia (33 [10%] vs 23 [7%]), and dehydration (16 [5%] vs seven [2%]). Treatment-related deaths occurred in 14 patients (4%) in the panitumumab group and eight (2%) in the control group. Five (2%) of the fatal adverse events in the panitumumab group were attributed to the experimental agent. We had appropriate samples to assess p16 status for 443 (67%) patients, of whom 99 (22%) were p16 positive. Median overall survival in patients with p16-negative tumours was longer in the panitumumab group than in the control group (11.7 months [95% CI 9.7-13.7] vs 8.6 months [6.9-11.1]; HR 0.73 [95% CI 0.58-0.93]; p = 0.0115), but this difference was not shown for p16-positive patients (11.0 months [7.3-12.9] vs 12.6 months [7.7-17.4]; 1.00 [0.62-1.61]; p = 0.998). In the control group, p16-positive patients had numerically, but not statistically, longer overall survival than did p16-negative patients (HR 0.70 [95% CI 0.47-1.04]).
Interpretation: Although the addition of panitumumab to chemotherapy did not improve overall survival in an unselected population of patients with recurrent or metastatic SCCHN, it improved progression-free survival and had an acceptable toxicity profile. p16 status could be a prognostic and predictive marker in patients treated with panitumumab and chemotherapy. Prospective assessment will be necessary to validate our biomarker findings
Traditional and Health-Related Philanthropy: The Role of Resources and Personality
I study the relationships of resources and personality characteristics to charitable giving, postmortem organ donation, and blood donation in a nationwide sample of persons in households in the Netherlands. I find that specific personality characteristics are related to specific types of giving: agreeableness to blood donation, empathic concern to charitable giving, and prosocial value orientation to postmortem organ donation. I find that giving has a consistently stronger relation to human and social capital than to personality. Human capital increases giving; social capital increases giving only when it is approved by others. Effects of prosocial personality characteristics decline at higher levels of these characteristics. Effects of empathic concern, helpfulness, and social value orientations on generosity are mediated by verbal proficiency and church attendance.
NEW PROPAGATION EFFECTS FOR THE INVERTED STRIP DIELECTRIC WAVEGUIDE FOR MILLIMETER WAVES
The existing theory for the inverted strip dielectric waveguide neglects the presence of additional constituent modes and the coupling between them at the strip sides. An improved theory which accounts for thesefeatures reveals interesting unanticipated physical effects, including leakage, resonances, mode coupling and modifications in transverse field distributions.1978 IEEE MTT-S International Microwave Symposium Digest : Ottawa, Canada, June 27-2
The degradation of p53 and its major E3 ligase Mdm2 is differentially dependent on the proteasomal ubiquitin receptor S5a.
p53 and its major E3 ligase Mdm2 are both ubiquitinated and targeted to the proteasome for degradation. Despite the importance of this in regulating the p53 pathway, little is known about the mechanisms of proteasomal recognition of ubiquitinated p53 and Mdm2. In this study, we show that knockdown of the proteasomal ubiquitin receptor S5a/PSMD4/Rpn10 inhibits p53 protein degradation and results in the accumulation of ubiquitinated p53. Overexpression of a dominant-negative deletion of S5a lacking its ubiquitin-interacting motifs (UIM)s, but which can be incorporated into the proteasome, also causes the stabilization of p53. Furthermore, small-interferring RNA (siRNA) rescue experiments confirm that the UIMs of S5a are required for the maintenance of low p53 levels. These observations indicate that S5a participates in the recognition of ubiquitinated p53 by the proteasome. In contrast, targeting S5a has no effect on the rate of degradation of Mdm2, indicating that proteasomal recognition of Mdm2 can be mediated by an S5a-independent pathway. S5a knockdown results in an increase in the transcriptional activity of p53. The selective stabilization of p53 and not Mdm2 provides a mechanism for p53 activation. Depletion of S5a causes a p53-dependent decrease in cell proliferation, demonstrating that p53 can have a dominant role in the response to targeting S5a. This study provides evidence for alternative pathways of proteasomal recognition of p53 and Mdm2. Differences in recognition by the proteasome could provide a means to modulate the relative stability of p53 and Mdm2 in response to cellular signals. In addition, they could be exploited for p53-activating therapies. This work shows that the degradation of proteins by the proteasome can be selectively dependent on S5a in human cells, and that this selectivity can extend to an E3 ubiquitin ligase and its substrate
Transmission of a global financial crisis shock to an emerging economy
Using a unique dataset consisting of all corporate loans in Pakistan, we study the impact of the global financial crisis (GFC) on the lending ability of its banking sector. We also take into account various bank and loan types along with extensive margins, firm size effects, and impact of information asymmetry. Our findings show that the Pakistani banking sector was indeed affected by the GFC as high exposure banks, who borrow relatively more internationally, reduce lending to local firms and this impact is larger for small firms. We also find differences in the lending ability of various bank types and loan types. By using direct information asymmetry measure, we find that banks reduced lending after the global financial crisis shock. However, the information gathered from the previous relationship of the borrower with relatively low exposure banks can overcome the negative financial shock and increase lending after the shock. These findings are very relevant in the context of the spillover effects of the GFC and have important policy implications for emerging markets
Structural analysis of MDM2 RING separates degradation from regulation of p53 transcription activity
MDM2–MDMX complexes bind the p53 tumor-suppressor protein, inhibiting p53's transcriptional activity and targeting p53 for proteasomal degradation. Inhibitors that disrupt binding between p53 and MDM2 efficiently activate a p53 response, but their use in the treatment of cancers that retain wild-type p53 may be limited by on-target toxicities due to p53 activation in normal tissue. Guided by a novel crystal structure of the MDM2–MDMX–E2(UbcH5B)–ubiquitin complex, we designed MDM2 mutants that prevent E2–ubiquitin binding without altering the RING-domain structure. These mutants lack MDM2's E3 activity but retain the ability to limit p53′s transcriptional activity and allow cell proliferation. Cells expressing these mutants respond more quickly to cellular stress than cells expressing wild-type MDM2, but basal p53 control is maintained. Targeting the MDM2 E3-ligase activity could therefore widen the therapeutic window of p53 activation in tumors
Temporal drag: transdisciplinarity and the 'case' of psychosocial studies
Psychosocial studies is a putatively ‘new’ or emerging field concerned with the irreducible relation between psychic and social life. Genealogically, it attempts to re-suture a tentative relation between mind and social world, individual and mass, internality and externality, norm and subject, and the human and non-human, through gathering up and re-animating largely forgotten debates that have played out across a range of other disciplinary spaces. If, as I argue, the central tenets, concepts and questions for psychosocial studies emerge out of a re-appropriation of what have become anachronistic or ‘useless’ concepts in other fields – ‘the unconscious’, for instance, in the discipline of psychology – then we need to think about transdisciplinarity not just in spatial terms (that is, in terms of the movement across disciplinary borders) but also in temporal terms. This may involve engaging with theoretical ‘embarrassments’, one of which – the notion of ‘psychic reality’ – I explore here
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