Mitochondria are tailored to meet the metabolic and signaling needs of each cell. To explore its molecular composition, we performed a proteomic survey of mitochondria from mouse brain, heart, kidney, and liver and combined the results with existing gene annotations to produce a list of 591 mitochondrial proteins, including 163 proteins not previously associated with this organelle. The protein expression data were largely concordant with large-scale surveys of RNA abundance and both measures indicate tissue-specific differences in organelle composition. RNA expression profiles across tissues revealed networks of mitochondrial genes that share functional and regulatory mechanisms. We also determined a larger "neighborhood" of genes whose expression is closely correlated to the mitochondrial genes. The combined analysis identifies specific genes of biological interest, such as candidates for mtDNA repair enzymes, offers new insights into the biogenesis and ancestry of mammalian mitochondria, and provides a framework for understanding the organelle's contribution to human disease.

No abstract

Purpose:To assess the relationship between parameters measured on dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in primary invasive breast cancer. Materials and Methods:This HIPAA-compliant study was a retrospective review of medical records and therefore approved by the institutional review board without the requirement for informed consent. Patients with a diagnosis of invasive breast cancer from January 2005 through December 2009 who underwent both DCE MR imaging and FDG PET/CT before treatment initiation were retrospectively identified. Fractional volumes were measured for ranges of signal enhancement ratio (SER) values from DCE MR imaging data and compared with maximum standardized uptake values (SUV max ) from FDG PET/CT data. Linear regression analysis was performed to clarify the relationship between SER and SUV max , adjusting for tumor size, pathologic grade, and receptor status. Results:Analyzed were 117 invasive breast cancers in 117 patients. Overall, a higher percentage of high washout kinetics was positively associated with SUV max (1.57% increase in SUV max per 1% increase in high washout; P = .020), and a higher percentage of low plateau kinetics was negatively associated with SUV max (1.19% decrease in SUV max per 1% increase in low plateau; P = .003). These relationships were strongest among triple-negative (TN) tumors (4.34% increase in SUV max per 1% increase in high washout and 2.65% decrease in SUV max per 1% increase in low plateau; P = .018 and .004, respectively). Conclusion:In invasive breast carcinoma, there is a positive relationship between the percentage of high washout and SUV max and a negative relationship between the percentage of low plateau and SUV max . These results are stronger in TN tumors.q RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup /suppl

No abstract