A comprehensive sensitivity analysis of microarray breast cancer classification under feature variability

Background  

Large discrepancies in signature composition and outcome concordance have been observed between different microarray breast cancer expression profiling studies. This is often ascribed to differences in array platform as well as biological variability. We conjecture that other reasons for the observed discrepancies are the measurement error associated with each feature and the choice of preprocessing method. Microarray data are known to be subject to technical variation and the confidence intervals around individual point estimates of expression levels can be wide. Furthermore, the estimated expression values also vary depending on the selected preprocessing scheme. In microarray breast cancer classification studies, however, these two forms of feature variability are almost always ignored and hence their exact role is unclear.     

Longitudinal proxy measurements in multiple sclerosis: patient-proxy agreement on the impact of MS on daily life over a period of two years

Background  

The use of self-report measurements in clinical settings is increasing. However, in patients with limitations that interfere with reliable self-assessment such as cognitive impairment or mood disturbances, as may be the case in multiple sclerosis (MS), data collection might be problematic. In these situations, information obtained from proxy respondents (e.g. partners) may replace self-ratings. The aim of this study was to examine the value of proxy ratings at separate points in time and to assess patient-proxy agreement on possible changes in disease impact of MS.     

Successful Outcome of Disseminated Fusarium musae Fungemia with Skin Localization Treated with Liposomal Amphotericin B and Voriconazole in a Patient with Acute Myeloid Leukemia

Fusarium spp. may cause invasive disseminated infections in immunocompromised patients, associated with significant morbidity and mortality. We describe a case of disseminated fusariosis with fungemia and skin localization caused by Fusarium musae in a patient with acute myeloid leukemia successfully treated using liposomal amphotericin B and voriconazole.

     

Towards a reporter system to identify regulators of cross-talk between salicylate and jasmonate signaling pathways in Arabidopsis

The plant signaling hormones salicylic acid (SA) and jasmonic acid (JA) are regulators of inducible defenses that are activated upon pathogen or insect attack. Cross-talk between SA- and JA-dependent signaling pathways allows a plant to finely tune its response to the attacker encountered. In Arabidopsis, pharmacological experiments revealed that SA exerts a strong antagonistic effect on JA-responsive genes, such as PDF1.2, indicating that the SA pathway can be prioritized over the JA pathway. SA-mediated suppression of the JA-responsive PDF1.2 promoter was exploited for setting up a genetic screen aiming at the isolation of signal transduction mutants that are impaired in this cross-talk mechanism. The PDF1.2 promoter was fused to the herbicide resistance gene BAR to allow for life/death screening of a population of mutagenized transgenic plants. Non-mutant plants should survive herbicide treatment when methyl jasmonate (MeJA) is applied, but suppression of the JA response by SA should be lethal in combination with the herbicide. Conversely, crucial SA/JA cross-talk mutants should survive the combination treatment. SA effectively suppressed the expression of the PDF1.2::BAR transgene. However, suppression of the BAR gene did not result in suppression of herbicide resistance. Hence, a screening method based on quantitative differences in the expression of a reporter gene may be better suited to identify SA/JA cross-talk mutants. Here, we demonstrate that the PDF1.2::GUS reporter will be excellently suited in this respect.Key words: plant defense, salicylic acid, jasmonic acid, cross-talk, mutant screen, Arabidopsis     

Mitochondrial mismatch analysis is insensitive to the mutational process

Mismatch distributions are histograms showing the pattern of nucleotide (or restriction) site differences between pairs of individuals in a sample. They can be used to test hypotheses about the history of population size and subdivision (if selective neutrality is assumed) or about selection (if a constant population size is assumed). Previous work has assumed that mutations never strike the same site twice, an assumption that is called the model of infinite sites. Fortunately, the results are surprisingly robust even when this assumption is violated. We show here that (1) confidence regions inferred using the infinite- sites model differ little from those inferred using a model of finite sites with uniform site-specific mutation rates, and (2) even when site- specific mutation rates follow a gamma distribution, confidence regions are little changed until the gamma shape parameter falls well below its plausible range, to roughly 0.01. In addition, we evaluate and reject the proposition that mismatch waves are produced by pooling data from several subdivisions of a structured population.      

Topography, purification and characterization of thyroidal 5'-nucleotidase

1. Subcellular studies of bovine thyroid indicate that 5'-nucleotidase is predominantly associated with plasma membranes, although a considerable part of this ectoenzyme is also found internalized. 2. The enzyme displaying the features of a glycoprotein has been purified 1400 times by detergent solubilization and two subsequent affinity chromatographic steps. 3. Thyroidal 5'-nucleotidase can be classified as an unspecific metallo-dependent 5'-ribonucleotide phosphohydrolase. The native enzyme exists as a dimer (MW 150 kDalton), composed of two similar or identical subunits.     

Psychosocial functioning, self-perception and body image and their auxologic correlates in growth hormone and oestrogen-treated young adult women with Turner syndrome

BACKGROUND: Few data are available on the psychosocial status of growth hormone (GH) and oestrogen treated women with Turner syndrome (TS). In this study, we evaluated psychosocial functioning, self-concept and body image in GH and oestrogen treated young adult women with TS and we studied the relationship with auxological parameters. PATIENTS AND METHODS: Thirty women with TS (mean +/- SD age: 22.1 +/- 2.4 years), all treated with GH and oestrogens if indicated, and an age-matched reference group of 44 non-Turner female students (age: 20.5 +/- 2.1 years) completed 3 questionnaires evaluating, respectively, behavioural and emotional problems (Young Adult Self Report), self-concept (Self Perception Profile for College Students) and body-image (Body Attitude Scale). RESULTS: TS patients did not report more behavioural and emotional problems compared to the non-TS females except for attention problems; they even reported fewer problems on some subscales (somatic complaints, thought problems, delinquent behaviour). TS patients did not differ from the non-TS female group in their bodily satisfaction. TS patients, particularly patients with a 45,X karyotype, perceived themselves as less socially competent. BMI was significantly related to the appraisal score of the Body Attitude Scale, whereas height was not related to any of the evaluated psychosocial parameters. CONCLUSION: The psychosocial adaptation of young adult women with TS, diagnosed at an early age and treated during childhood with GH and oestrogens if indicated, appears to be quite satisfactory. Follow-up of adult TS patients should not neglect the problem of overweight and associated psychosocial consequences.