PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 8068847

M-estimation in cross-over trials.

E M Chi
View original source ↗Export metadata ↓

Abstract

A robust procedure, combined M-estimation, is proposed for analyzing cross-over data with possible within- and between-subject outliers. The mean squared error properties of these combined M-estimates for direct treatment effect contrasts and carryover treatment effect contrasts are examined through simulation studies. They are found to be superior to those of the generalized least squares estimates when there are possible within- and between-subject outliers.

Explore related subjects

AmantadineAsthmaBiometryClinical Trials as TopicForced Expiratory VolumeHumansLeast-Squares AnalysisParkinson DiseaseComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E M Chi. 1994. M-estimation in cross-over trials.. https://pubmed.ncbi.nlm.nih.gov/8068847/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Enhancing the effect of radionuclide tumor targeting, using lysosomotropic weak bases.

PURPOSE: The aim of the present study was to investigate if treatment with lysosomotropic weak bases could increase the intracellular retention of radiohalogens and thereby increase the therapeutic effect of radionuclide tumor targeting. METHODS AND MATERIALS: Four different lysosomotropic bases, chloroquine, ammonium chloride, amantadine, and thioridazine, were investigated for their ability to increase radiohalogen retention in vitro. The two most promising substances, chloroquine and ammonium chloride, were studied in several cell lines (A431, U343MGaCl2:6, SKOV-3, and SKBR-3) in combination with radiolabeled epidermal growth factor (EGF) or the HER2 binding affibody (Z(HER2:4))(2). RESULTS: The uptake and retention of radionuclides was found to be substantially increased by simultaneous treatment with the lysosomotropic bases. The effect was, however, more pronounced in the epidermal growth factor:epidermal growth factor receptor (EGF:EGFR) system than in the (Z(HER2:4))(2):HER2 system. The therapeutic effect of ammonium chloride treatment combined with (211)At-EGF was also studied. The effect obtained after combined treatment was found to be much better than after (211)At-EGF treatment alone. CONCLUSIONS: The encouraging results from the present study indicate that the use of lysosomotropic weak bases is a promising approach for increasing the therapeutic effect of radionuclide targeting with radiohalogens.

Amantadine↗
PubMed2007

Viral determinants of resistance to treatment in patients with hepatitis C.

Chronic hepatitis C virus (HCV) infection affects more than 170 million persons worldwide and is responsible for the development of liver cirrhosis in many cases. Standard treatment with pegylated alpha interferon (IFN-alpha) in combination with the nucleoside analogue ribavirin leads to a sustained virologic response in approximately half of the patients. IFN-alpha is classified as an indirect treatment, as it interacts with the host's immune response. The mechanism of action of ribavirin is still unknown. The benefit of triple therapy by adding other antiviral agents, e.g., amantadine, is controversial. Currently, new direct antiviral drugs (HCV protease/polymerase inhibitors) are being evaluated in phase 1/phase 2 trials. Phenotypic resistance to antiviral therapy has been attributed to amino acid variations within distinct regions of the HCV polyprotein. While sensitivity to IFN-alpha-based antiviral therapy in vivo is clearly correlated with the number of mutations within the HCV NS5A protein, the underlying functional mechanisms for this association are unknown. In turn, in vitro, several mechanisms to circumvent the host immune defense or to block treatment-induced antiviral activities have been described for different HCV proteins. By the introduction of direct antiviral drugs, hepatitis C therapy now is entering a new era in which the development of resistance may become the most important parameter for treatment success or failure.

Amantadine↗