WITHDRAWN: Cardiac Troponin T: An Early Molecule Marker of Normalization of Left Ventricular Ejection Fraction in Patients with Peripartum Cardiomyopathy

Psychometric and clinical assessment of the 10-item reduced version of the Fatigue Scale-Child instrument

Fatigue is one of the most debilitating conditions associated with cancer and anticancer therapy. The lack of reliable and valid self-report instruments has prevented accurate assessment of fatigue in pediatric oncology patients. The purpose of this study was to identify the most sensitive and specific score, that is, the "cut score," on the Fatigue Scale-Child (FS-C) to identify those children with high cancer-related fatigue in need of clinical intervention. We first used Rasch methods to identify the items on the FS-C that distinguished children with high cancer-related fatigue from other children; our findings indicated that the FS-C needed to be reduced from 14 items to 10 items. We then assessed the 10-item FS-C for its psychometric properties and applied the receiver operating characteristics curve analysis to the FS-C responses from 221 children (aged 7-12 years) receiving anticancer treatment. The cut score identified with 75% sensitivity and 73.5% specificity was 12; 73 (33%) patients scored 12 or higher. Findings from this validated instrument provide a needed guide for clinicians to interpret fatigue scores and provide clinical interventions for this debilitating condition to their pediatric patients with cancer.

The specific regulation of immune responses by CD8+ T cells restricted by the MHC class Ib molecule, Qa-1

Over the last three decades considerable evidence has accumulated that CD8(+) T cells regulate peripheral immune responses, in part, by specifically controlling the outgrowth of antigen-triggered CD4(+) T cells. This regulatory function of CD8(+) T cells has been shown, in vivo, to control the emergence of autoreactive CD4(+) T cells as well as CD4(+) T cells reactive to conventional antigens, including alloantigens. In this review, we summarize the evidence that this immune suppression mediated by CD8(+) T cells is dependent, in part, on specific cognate interactions between MHC class I-restricted regulatory CD8(+) cells and antigen-activated CD4(+) T cells. Moreover, we review the evidence that regulatory CD8(+) T cells recognize antigen-activated CD4(+) T cells in a TCR specific manner restricted by the MHC class Ib molecule, Qa-1. The Qa-1 molecule may be uniquely qualified to serve this MHC restrictive function because, unlike conventional MHC molecules, it is preferentially and transiently expressed on activated and not resting CD4(+) T cells. This may assure that only recently antigen-activated CD4(+) T cells expressing Qa-1/TCR peptide complexes will induce regulatory CD8(+) T cells and subsequently become susceptible to regulation. Because Qa-1 also binds to self Qdm peptides that trigger NK (CD94/ NKG2) receptors on CD8(+) T cells, the machinery for homeostatic regulation of regulatory CD8(+) T cells can be envisioned. Finally, we propose a model by which these TCR specific, Qa-1-restricted regulatory CD8(+) T cells selectively downregulate antigen-activated T cells expressing TCRs of certain affinities. Ultimately these regulatory CD8(+) T cells control the peripheral TCR repertoire during the course of immune responses to both self and foreign antigens.