ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Lifetime data analysis 3 (1997), S. 337-351 
    ISSN: 1572-9249
    Keywords: Accelerated life test ; EM algorithm ; factorial model ; identifiability ; likelihood ratio test ; maximum likelihood estimation ; multivariate exponential distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract This paper examines modeling and inference questions for experiments in which different subsets of a set of k possibly dependent components are tested in r different environments. In each environment, the failure times of the set of components on test is assumed to be governed by a particular type of multivariate exponential (MVE) distribution. For any given component tested in several environments, it is assumed that its marginal failure rate varies from one environment to another via a change of scale between the environments, resulting in a joint MVE model which links in a natural way the applicable MVE distributions describing component behavior in each fixed environment. This study thus extends the work of Proschan and Sullo (1976) to multiple environments and the work of Kvam and Samaniego (1993) to dependent data. The problem of estimating model parameters via the method of maximum likelihood is examined in detail. First, necessary and sufficient conditions for the identifiability of model parameters are established. We then treat the derivation of the MLE via a numerically-augmented application of the EM algorithm. The feasibility of the estimation method is demonstrated in an example in which the likelihood ratio test of the hypothesis of equal component failure rates within any given environment is carried out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
  • 3
    Publication Date: 1992-10-01
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2005-11-16
    Description: Optimal therapy for patients (pt) with B-cell RIL remains controversial, and many treatment options include rituximab (R). Based on phase I–II studies of FND (fludarabine 25 mg/m2, d1–3; mitoxantrone 10 mg/m2, d1; dexamethasone 20 mg d1–5) treatment for RIL in which we observed a 48% CR rate, we studied the combination of R (375 mg/m2 d1) and FND for pt with RIL. Pt could not have received prior fludarabine, and were eligible if they had not previoiusly received R or had a response lasting at least 6 months (mo) to prior treament with R. Cycles were repeated every 4 weeks, and required an absolute neutrophil count of 1,000 and a platelet count of 100,000 to administer each cycle. Forty-two pt were entered onto this trial; however, one never received therapy after signing consent, and two were deemed ineligible after signing consent because of low cardiac ejection fractions (EF). All pt underwent biopsy prior to therapy; histologies included follicular gr1–3 in 30 pt, small lymphocytic in 7, marginal zone in 2. The median age was 58 (range 39–84) and median prior therapies 1 (range 1–3). The median number of cycles of R-FND delivered per patient was 6 (range 1–8). Of the 39 eligible and evaluable pt, 19 entered CR and 9 CRu for a CR/CRu rate of 72%, and 9 entered PR (23%) for an overall response rate of 95%. One had stable disease (SD), and one progression (PD). Eight underwent high dose therapy followed by autologous stem cell transplant (SCT) following a response to R-FND therapy. Five of these had achieved CR/CRu with R-FND after 1–6 cycles, and 3 PR after 2–6 cycles. In all, 14 of the 37 responders to R-FND (37%) have had progression; however, none of the 8 who underwent SCT has had progression, nor has the one with SD. In, 24 (62%) still remain free of progression with a median follow-up for living pt of 32 mo. In all, 6 pt have died of PD, including 4 who were ineligible for or refused SCT. The 2-year failure-free survival (FFS) and overall survival (OS) results for all pt are 66% and 90%. The 2-year FFS for responders is 66%, and the 2-year OS for all pt, with pt undergoing SCT censored at time of SCT is 81%. As expected, the main toxicity following R-FND was hematologic: gr 4 neutropenia occurred in 15 pt and in 15 of 130 cycles for which information is available, and gr 3–4 thrombocytopenia in 5 pt and in 6 cycles. In all, 13 of the 28 responders received less than 6 cycles of therapy; reasons included prolonged thrombocytopenia in 4, early SCT in 6, asymptomatic decrease in EF in one, and physician’s choice in 2. No patients died of acute toxicity while receiving R-FND. We conclude that 1) R-FND is a very active and well tolerated regimen for relapsed indolent lymphomas 2) Results appear very favorable compared to prior studies with FND 3) In this population, patients receiving R-FND were able to undergo SCT, and had very favorable outcomes.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...