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Mammalian eukaryotic translation initiation factor 3 (eIF3) is the largest complex of the translation initiation factors. The eIF3 complex is comprised of thirteen subunits, which are named eIF3a to eIF3 m in most multicellular organisms. The eIF3e gene locus is one of the most frequent integration sites of mouse mammary tumor virus (MMTV), which induces mammary tumors in mice. MMTV‐integration events result in the expression of C‐terminal‐truncated eIF3e proteins, leading to mammary tumor formation. We have shown that tumor formation can be partly caused by activation of hypoxia‐inducible factor 2α. To investigate the function of eIF3e in mammals, we generated eIF3e‐deficient mice. These eIF3e−/− mice are embryonically lethal, while eIF3e+/− mice are much smaller than wild‐type mice. In addition, eIF3e+/− mouse embryonic fibroblasts (MEFs) contained reduced levels of eIF3a and eIF3c subunits and exhibited reduced cellular proliferation. These results suggest that eIF3e is essential for embryonic development in mice and plays a role in maintaining eIF3 integrity. [ABSTRACT FROM AUTHOR]

Aims: The clinical significance of papillary muscle hypertrophy and its electrocardiography (ECG) findings has not been fully elucidated. This study aimed to investigate the relationship between ECG findings and papillary muscle hypertrophy and to confirm the importance of papillary muscle measurements on transthoracic echocardiography (TTE). Methods and Results: Of the 237 consecutive patients who showed left ventricular hypertrophy (LVH) pattern on a 12‐lead ECG, TTE data were available for 101 patients. The patients were divided into the two groups according to the presence (ECG‐LVH [strain pos] group, n = 60) or absence (ECG‐LVH [strain neg] group, n = 41) of LV strain pattern (study 1). The prevalence of papillary muscle hypertrophy using TTE was significantly higher in the ECG‐LVH (strain neg) group than in the ECG‐LVH (strain pos) group (P = .0002). Of the 42 cases with papillary muscle hypertrophy, 5 cases (12%) showed isolated papillary muscle hypertrophy with normal geometry. ECG data were prospectively analyzed for 36 patients who were diagnosed with papillary muscle hypertrophy by TTE (study 2). The prevalence of LV strain pattern was significantly higher in patients with LV wall hypertrophy than in those without LV wall hypertrophy (P = .04). Of the 25 cases with papillary muscle hypertrophy, 6 cases (24%) showed normal geometry and 4 cases (16%) showed ECG abnormality. Conclusions: Isolated papillary muscle hypertrophy can cause ECG abnormalities such as LV high voltage and LV strain pattern. Particular attention must be paid to the papillary muscle during echocardiographic examinations. [ABSTRACT FROM AUTHOR]