Novel nuclear translocation of inositol polyphosphate 4-phosphatase is associated with cell cycle, proliferation and survival.

Inositol polyphosphate 4 phosphatase type I enzyme (INPP4A) has a well-documented function in the cytoplasm where it terminates the phosphatidylinositol 3-kinase (PI 3-K) pathway by acting as a negative regulator. In this study, we demonstrate for the first time that INPP4A shuttles between the cytoplasm and the nucleus. Nuclear INPP4A is enzymatically active and in dynamic equilibrium between the nucleus and cytoplasm depending on the cell cycle stage, with highest amounts detected in the nucleus during the G0/G1 phase. Moreover, nuclear INPP4A is found to have direct proliferation suppressive activity. Cells constitutively overexpressing nuclear INPP4A exhibit massive apoptosis. In human tissues as well as cell lines, lower nuclear localization of INPP4A correlate with cancerous growth. Together, our findings suggest that nuclear compartmentalization of INPP4A may be a mechanism to regulate cell cycle progression, proliferation and apoptosis. Our results imply a role for nuclear-localized INPP4A in tumor suppression in humans.

Utility of contemporaneous dual read in the setting of emergency teleradiology reporting.

PURPOSE: Emergency radiology requires rapid and accurate interpretation of imaging examinations. Missed findings may lead to adverse outcomes. Double reporting may be used to minimize errors. Limited contemporaneous double reporting may be most efficient and cost-effective, but no data exists. This study is intended to examine the benefits of double reading and identify examinations where this would be most useful. METHODS: In this study, dual reporting was conducted in a parallel reading environment in a teleradiology practice for 3779 radiological procedures performed at two radiology centers in the USA over a period of 4 months. Discrepancies between reads were scored using the ACR peer review scoring system and grouped by modality and body part. Errors were tabulated across the study types, followed by identification of statistically significant differences. The interaction between image number and odds of an error was ascertained. RESULTS: In 145 instances (3.8%; 95 % CI, 3.2-4.4%), double reporting identified errors, leading to report modification. Study type was significantly related to error frequency (p = 0.0001), with higher than average frequencies of error seen for CT abdomen and pelvis and MRI head or spine, but lower than average for CT head, CT spine, and ultrasound. Image number was positively associated with error odds, but was not independently significant in a joint logistic regression model that included study type. CONCLUSION: Dual reporting identifies missed findings in about 1 of 25 emergency studies. This benefit varies substantially across study types and limited double reporting, merits further investigation as a cost-effective practice improvement strategy.