510 research outputs found

    Markov model and markers of small cell lung cancer: assessing the influence of reversible serum NSE, CYFRA 21-1 and TPS levels on prognosis

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    High serum NSE and advanced tumour stage are well-known negative prognostic determinants of small cell lung cancer (SCLC) when observed at presentation. However, such variables are reversible disease indicators as they can change during the course of therapy. The relationship between risk of death and marker level and disease state during treatment of SCLC chemotherapy is not known. A total of 52 patients with SCLC were followed during cisplatin-based chemotherapy (the median number of tumour status and marker level assessments was 4). The time-homogeneous Markov model was used in order to analyse separately the prognostic significance of change in the state of the serum marker level (NSE, CYFRA 21-1, TPS) or the change in tumour status. In this model, transition rate intensities were analysed according to three different states: alive with low marker level (state 0), alive with high marker level (state 1) and dead (absorbing state). The model analysing NSE levels showed that the mean time to move out of state ‘high marker level’ was short (123 days). There was a 44% probability of the opposite reversible state ‘low marker level’ being reached, which demonstrated the reversible property of the state ‘high marker level’. The relative risk of death from this state ‘high marker level’ was about 2.24 times greater in comparison with that of state 0 ‘low marker level’ (Wald's test; P < 0.01). For patients in state ‘high marker level’ at time of sampling, the probability of death increased dramatically, a transition explaining the rapid decrease in the probability of remaining stationary at this state. However, a non-nil probability to change from state 1 ‘high marker level’ to the opposite transient level, state 0 ‘low marker level’, was observed suggesting that, however infrequently, patients in state 1 ‘high marker level’ might still return to state 0 ‘low marker level’. Almost similar conclusions can be drawn regarding the three-state model constructed using the tumour response status. For the two cytokeratin markers, the Markov model suggests the lack of a true reversible property of these variables as there was only a very weak probability of a patient returning to state ‘low marker level’ once having entered state ‘high marker level’. In conclusion, The Markov model suggests that the observation of an increase in serum NSE level or a lack of response of the disease at any time during follow-up (according to the homogeneous assumption) was strongly associated with a worse prognosis but that the reversion to a low mortality risk state remains possible. © 1999 Cancer Research Campaig

    CYFRA 21-1 level predicts survival in non-small-cell lung cancer patients receiving gefitinib as third-line therapy

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    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) as gefitinib emerged as an accepted treatment in second- or third-line setting in NSCLC. However, clinical surrogate markers of EGFR-TKI activity in NSCLC patients remain to be identified and we studied the prognostic value of CYFRA 21-1 in this setting. Serum samples from 53 patients with NSCLC receiving gefitinib after failure of at least a platinum-containing regimen were prospectively collected from January 2002 to December 2003. Multivariate analysis demonstrated an independent negative impact on survival for a level of CYFRA 21-1 higher than 3.5 ng ml−1 (HR=2.45, 95% CI 1.13–5.29; P=0.02). In conclusion, CYFRA 21-1 is a tool available to predict the survival of NSCLC patients receiving gefitinib as third-line therapy in an independent manner. In case of a CYFRA 21-1 level higher than 3.5 ng ml−1, treatment with gefitinib needs further evaluation giving its relative poor effect on survival

    Secondary contact and admixture between independently invading populations of the Western corn rootworm, diabrotica virgifera virgifera in Europe

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    The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show that i) genetic variation is greater in the contact zone than in the parental outbreaks; ii) several signs of admixture were detected in some Venetian samples, in a Bayesian analysis of the population structure and in an approximate Bayesian computation analysis of historical scenarios and, finally, iii) allelic frequency clines were observed at microsatellite loci. The contact between the invasive outbreaks in North-West Italy and Central and South-Eastern Europe resulted in a zone of admixture, with particular characteristics. The evolutionary implications of the existence of a zone of admixture in Northern Italy and their possible impact on the invasion success of the western corn rootworm are discussed

    Prognostic role of serum cytokeratin 19 fragments in advanced non-small-cell lung cancer: association of marker changes after two chemotherapy cycles with different measures of clinical response and survival

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    Prognostic implication of serum cytokeratin 19 fragments (CYFRA 21-1) was explored in 60 advanced NSCLC patients, whereas in 45 patients assessable for serological response a ⩾35% CYFRA 21-1 decline after two chemotherapy cycles was strongly associated with non-progression (NP), defined as a sum of objective response (OR)+stable disease (P<0.0001) and survival (P=0.0002). Association of OR with survival was not significant. In multivariate survival analysis, ⩾35% marker decline and radiological NP status were found as major determinants of prolonged survival with RR: 0.37 (P=0.01) and 0.63 (P=0.01), respectively. In advanced NSCLC patients, NP reflects therapeutic efficacy better than traditional OR. CYFRA 21-1 ⩾35% decline seems to be a reliable surrogate marker of treatment efficacy in terms of survival

    The influence of semantic and phonological factors on syntactic decisions: An event-related brain potential study

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    During language production and comprehension, information about a word's syntactic properties is sometimes needed. While the decision about the grammatical gender of a word requires access to syntactic knowledge, it has also been hypothesized that semantic (i.e., biological gender) or phonological information (i.e., sound regularities) may influence this decision. Event-related potentials (ERPs) were measured while native speakers of German processed written words that were or were not semantically and/or phonologically marked for gender. Behavioral and ERP results showed that participants were faster in making a gender decision when words were semantically and/or phonologically gender marked than when this was not the case, although the phonological effects were less clear. In conclusion, our data provide evidence that even though participants performed a grammatical gender decision, this task can be influenced by semantic and phonological factors

    Darbepoetin alfa for treating chemotherapy-induced anemia in patients with a baseline hemoglobin level < 10 g/dL versus ≥10 g/dL: an exploratory analysis from a randomized, double-blind, active-controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Several studies have shown that darbepoetin alfa, an erythropoiesis-stimulating agent (ESA), can reduce transfusions and increase hemoglobin (Hb) levels in patients with chemotherapy-induced anemia (CIA). Recent safety concerns, however, have prompted changes to ESA product information. In the European Union and United States, ESA therapy initiation for CIA is now recommended at a Hb level ≤10 g/dL. The present exploratory analysis examined how ESA initiation at this Hb level may impact patient care.</p> <p>Methods</p> <p>Data from a phase 3 randomized trial were retrospectively reanalyzed. CIA patients with nonmyeloid malignancies were randomized 1:1 to 500 mcg darbepoetin alfa every three weeks (Q3W) or 2.25 mcg/kg darbepoetin alfa weekly (QW) for 15 weeks. A previously published report from this trial showed Q3W dosing was non-inferior to QW dosing for reducing transfusions from week 5 to end-of-the-treatment period (EOTP). In the present analysis, outcomes were reanalyzed by baseline Hb <10 g/dL and ≥10 g/dL. Endpoints included transfusion rates, Hb outcomes, and safety profiles.</p> <p>Results</p> <p>This study reanalyzed 351 and 354 patients who initiated ESA therapy at a baseline Hb of <10 g/dL or ≥10 g/dL, respectively. From week 5 to EOTP, the estimated Kaplan-Meier transfusion incidence (Q3W vs QW) was lower in the ≥10 g/dL baseline-Hb group (14% vs 21%) compared with the <10 g/dL baseline-Hb group (36% vs 41%). By week 5, the ≥10 g/dL baseline-Hb group, but not the <10 g/dL baseline-Hb group, achieved a mean Hb ≥11 g/dL. The Kaplan-Meier estimate of percentage of patients (Q3W vs QW) who achieved Hb ≥11 g/dL from week 1 to EOTP was 90% vs 85% in the ≥10 g/dL baseline-Hb group and 54% vs 57% in the <10 g/dL baseline-Hb group. Both baseline-Hb groups maintained mean Hb levels <12 g/dL and had similar safety profiles, though more patients in the ≥10 g/dL baseline-Hb group reached the threshold Hb of ≥13 g/dL.</p> <p>Conclusion</p> <p>In this exploratory analysis, darbepoetin alfa Q3W and QW raised Hb levels and maintained mean Hb at <12 g/dL in both baseline-Hb groups. The ≥10 g/dL baseline-Hb group had fewer transfusions and faster anemia correction. Additional studies should prospectively evaluate the relationship between Hb levels at ESA initiation and outcomes.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier NCT00118638.</p

    Social features of online networks: the strength of intermediary ties in online social media

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    An increasing fraction of today social interactions occur using online social media as communication channels. Recent worldwide events, such as social movements in Spain or revolts in the Middle East, highlight their capacity to boost people coordination. Online networks display in general a rich internal structure where users can choose among different types and intensity of interactions. Despite of this, there are still open questions regarding the social value of online interactions. For example, the existence of users with millions of online friends sheds doubts on the relevance of these relations. In this work, we focus on Twitter, one of the most popular online social networks, and find that the network formed by the basic type of connections is organized in groups. The activity of the users conforms to the landscape determined by such groups. Furthermore, Twitter's distinction between different types of interactions allows us to establish a parallelism between online and offline social networks: personal interactions are more likely to occur on internal links to the groups (the weakness of strong ties), events transmitting new information go preferentially through links connecting different groups (the strength of weak ties) or even more through links connecting to users belonging to several groups that act as brokers (the strength of intermediary ties).Comment: 14 pages, 18 figure
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