The combined utility of extended focused assessment with sonography for trauma and chest x-ray in blunt thoracic trauma.

BACKGROUND: Portable chest x-ray (CXR) and extended focused assessment with sonography for trauma (EFAST) screen patients for thoracic injury in the trauma bay. It is unclear if one test alone is sufficient, if both are required, or if the two investigations are complementary. Study objectives were to define the combined diagnostic yield of EFAST and CXR among stable blunt thoracic trauma patients and to determine if a normal EFAST and CXR might obviate the need for computed tomography (CT) scan of the chest. METHODS: All blunt trauma patients 15 years or older presenting to LAC+USC Medical Center in 2016 were screened. Only patients who underwent CT thorax were included. Patients were excluded if they presented more than 24 hours after injury, were transferred, or if they did not undergo EFAST and CXR. Demographics, physical examination (PEx) of the thorax, injury data, investigations, procedures, and outcomes were collected. The EFAST, CXR, and PEx findings were compared to the gold standard CT thorax to calculate the diagnostic yield of each investigation and combinations thereof in the assessment for clinically significant thoracic injury. RESULTS: One thousand three hundred eleven patients met inclusion/exclusion criteria. Most common mechanisms of injury were motor vehicle collision (n = 385, 29%) and auto versus pedestrian trauma (n = 379, 29%). Mean Injury Severity Score was 11 (1-75), with mean Abbreviated Injury Scale chest score of 1.6 (1-6). The sensitivities of EFAST, CXR, and PEx, either individually or in combination, were less than 0.73 in the detection of clinically significant thoracic injury. The most common missed clinically significant injuries were sternal fractures, scapular fractures, clavicular fractures, and pneumothoraces. Motorcycle collisions and auto versus pedestrian traumas resulted in the highest rates of missed injury. CONCLUSION: Even in conjunction with the physical examination, the sensitivity of EFAST+CXR in the detection of clinically significant thoracic injury is low. Therefore, if clinical suspicion for injury exists after blunt thoracic trauma, a normal EFAST+CXR is insufficient to exclude injury and CT scan of the chest should be performed. LEVEL OF EVIDENCE: Diagnostic tests/criteria, level III.

A molecular cascade modulates MAP1B and confers resistance to mTOR inhibition in human glioblastoma.

Background: Clinical trials of therapies directed against nodes of the signaling axis of phosphatidylinositol-3 kinase/Akt/mammalian target of rapamycin (mTOR) in glioblastoma (GBM) have had disappointing results. Resistance to mTOR inhibitors limits their efficacy. Methods: To determine mechanisms of resistance to chronic mTOR inhibition, we performed tandem screens on patient-derived GBM cultures. Results: An unbiased phosphoproteomic screen quantified phosphorylation changes associated with chronic exposure to the mTOR inhibitor rapamycin, and our analysis implicated a role for glycogen synthase kinase (GSK)3B attenuation in mediating resistance that was confirmed by functional studies. A targeted short hairpin RNA screen and further functional studies both in vitro and in vivo demonstrated that microtubule-associated protein (MAP)1B, previously associated predominantly with neurons, is a downstream effector of GSK3B-mediated resistance. Furthermore, we provide evidence that chronic rapamycin induces microtubule stability in a MAP1B-dependent manner in GBM cells. Additional experiments explicate a signaling pathway wherein combinatorial extracellular signal-regulated kinase (ERK)/mTOR targeting abrogates inhibitory phosphorylation of GSK3B, leads to phosphorylation of MAP1B, and confers sensitization. Conclusions: These data portray a compensatory molecular signaling network that imparts resistance to chronic mTOR inhibition in primary, human GBM cell cultures and points toward new therapeutic strategies.

Validity and reliability of the Internalized Stigma of Smoking Inventory: An exploration of shame, isolation, and discrimination in smokers with mental health diagnoses.

BACKGROUND AND OBJECTIVES: De-normalization of smoking as a public health strategy may create shame and isolation in vulnerable groups unable to quit. To examine the nature and impact of smoking stigma, we developed the Internalized Stigma of Smoking Inventory (ISSI), tested its validity and reliability, and explored factors that may contribute to smoking stigma. METHODS: We evaluated the ISSI in a sample of smokers with mental health diagnoses (N = 956), using exploratory and confirmatory factor analysis, and assessed construct validity. RESULTS: Results reduced the ISSI to eight items with three subscales: smoking self-stigma related to shame, felt stigma related to social isolation, and discrimination experiences. Discrimination was the most commonly endorsed of the three subscales. A multivariate generalized linear model predicted 21-30% of the variance in the smoking stigma subscales. Self-stigma was greatest among those intending to quit; felt stigma was highest among those experiencing stigma in other domains, namely ethnicity and mental illness-based; and smoking-related discrimination was highest among women, Caucasians, and those with more education. DISCUSSION AND CONCLUSION: Smoking stigma may compound stigma experiences in other areas. Aspects of smoking stigma in the domains of shame, isolation, and discrimination were related to modeled stigma responses, particularly readiness to quit and cigarette addiction, and were found to be more salient for groups where tobacco use is least prevalent. SCIENTIFIC SIGNIFICANCE: The ISSI measure is useful for quantifying smoking-related stigma in multiple domains.

Medical Student Usage of the American College of Radiology Appropriateness Criteria.

RATIONALE AND OBJECTIVES: Educating medical students on appropriate imaging utilization has been increasingly recognized as important for patient care. The American College of Radiology Appropriateness Criteria (ACR-AC) is designed to support evidence-based imaging examination selection. We sought to assess whether medical students order imaging studies independently, what resources they use for guidance, and whether they use the ACR-AC in clinical practice. A secondary aim was to determine whether increasing familiarity with the ACR-AC could impact student usage. MATERIALS AND METHODS: We surveyed third year medical students at a single institution on their imaging practices, familiarity with the ACR-AC, and preferences among available resources to guide proper examination selection. The survey was performed in person before a lecture. We also designed a brief intervention to improve familiarity with the ACR-AC and then reassessed students to determine any effect on utilization. RESULTS: The response rate for the initial survey was 103 of 109 (94%) and the response rate for the second survey was 99 of 109 (91%).Our initial survey found students initiated imaging orders independently (74 of 100, 74.8%) and consulted resources to assist in examination selection (50 of 74, 67.6%). Students expressed a preference for non-ACR-AC resources, notably Up to Date via its online mobile application.Few students (8 of 71, 11.3%) were familiar with the ACR-AC. After an intervention to increase familiarity with the ACR-AC, student awareness of the ACR-AC increased to 61 of 74 (82.4%). However, usage among those familiar with the resource remained low, 13 of 61(21.3%) versus 3 of 8 (37.5%). CONCLUSIONS: Use of the ACR-AC was low among third year medical students. After increasing students' familiarity with the ACR-AC, their usage in a clinical setting did not increase. The largest barrier to use may be the lack of a quick, easy to use online mobile application-based interface.

Maximizing retention with high risk participants in a clinical trial.

PURPOSE: To describe effective retention strategies in a clinical trial with a high risk, low-income, and vulnerable patient population with serious mental illness. DESIGN: Follow-up assessments were conducted for a randomized clinical tobacco treatment trial at 3, 6, and 12 months postbaseline. Initial follow-up rates of <40% at 3 months led to implementation of proactive retention strategies including obtaining extensive contact information; building relationships with case managers and social workers; contacting jails and prisons; text messaging, e-mailing, and messaging via social networking sites; identifying appointments via electronic medical record; and field outreach to treatment facilities, residences, and parks. SETTING: Large urban public hospital. SUBJECTS: Participants were current smokers recruited from 100% smoke-free locked psychiatry units. MEASURES: Assessments covered demographics, substance use, and mental health functioning. ANALYSIS: Retention rates were plotted over time in relation to key retention strategies. Chi-square and t-tests were used to examine participant predictors of retention at each follow-up. At the 12-month follow-up, the retention strategies that most frequently led to assessment completion were identified. RESULTS: The sample (N = 100) was 65% male; age x = 39.5 years (SD = 11.3); 44% non-Hispanic white; 46% on Medicaid and 34% uninsured; 79% unemployed; and 48% unstably housed. Proactive retention strategies dramatically increased follow-up rates, concluding at 3 months = 82.65%, 6 months = 89.69%, and 12 months = 92.78%. Married and divorced/separated/widowed participants, those with higher income, and participants with alcohol or illicit drug problems had increased retention from 3- to 12-month follow-up. CONCLUSION: Follow-up rates improved as proactive methods to contact participants were implemented. Dedicated research staff, multiple methods, community networking, and outreach within drug treatment settings improved retention.

CD44v6 regulates growth of brain tumor stem cells partially through the AKT-mediated pathway.

Identification of stem cell-like brain tumor cells (brain tumor stem-like cells; BTSC) has gained substantial attention by scientists and physicians. However, the mechanism of tumor initiation and proliferation is still poorly understood. CD44 is a cell surface protein linked to tumorigenesis in various cancers. In particular, one of its variant isoforms, CD44v6, is associated with several cancer types. To date its expression and function in BTSC is yet to be identified. Here, we demonstrate the presence and function of the variant form 6 of CD44 (CD44v6) in BTSC of a subset of glioblastoma multiforme (GBM). Patients with CD44(high) GBM exhibited significantly poorer prognoses. Among various variant forms, CD44v6 was the only isoform that was detected in BTSC and its knockdown inhibited in vitro growth of BTSC from CD44(high) GBM but not from CD44(low) GBM. In contrast, this siRNA-mediated growth inhibition was not apparent in the matched GBM sample that does not possess stem-like properties. Stimulation with a CD44v6 ligand, osteopontin (OPN), increased expression of phosphorylated AKT in CD44(high) GBM, but not in CD44(low) GBM. Lastly, in a mouse spontaneous intracranial tumor model, CD44v6 was abundantly expressed by tumor precursors, in contrast to no detectable CD44v6 expression in normal neural precursors. Furthermore, overexpression of mouse CD44v6 or OPN, but not its dominant negative form, resulted in enhanced growth of the mouse tumor stem-like cells in vitro. Collectively, these data indicate that a subset of GBM expresses high CD44 in BTSC, and its growth may depend on CD44v6/AKT pathway.

Identification of differentially expressed proteins in murine embryonic and postnatal cortical neural progenitors.

BACKGROUND: The central nervous system (CNS) develops from a heterogeneous pool of neural stem and progenitor cells (NSPC), the underlying differences among which are poorly understood. The study of NSPC would be greatly facilitated by the identification of additional proteins that mediate their function and that would distinguish amongst different progenitor populations. METHODOLOGY/PRINCIPAL FINDINGS: To identify membrane and membrane-associated proteins expressed by NSPC, we used a proteomics approach to profile NSPC cultured as neurospheres (NS) isolated from the murine cortex during a period of neurogenesis (embryonic day 11.5, E11.5), as compared to NSPC isolated at a peak of gliogenesis (postnatal day 1, P0) and to differentiated E11.5 NS. 54 proteins were identified with high expression in E11.5 NS, including the TrkC receptor, several heterotrimeric G proteins, and the Neogenin receptor. 24 proteins were identified with similar expression in E11.5 and P0 NS over differentiated E11.5 NS, and 13 proteins were identified with high expression specifically in P0 NS compared to E11.5 NS. To illustrate the potential relevance of these identified proteins to neural stem cell biology, the function of Neogenin was further studied. Using Fluorescence Activated Cell Sorting (FACS) analysis, expression of Neogenin was associated with a self-renewing population present in both E11.5 and adult subventricular zone (SVZ) NS but not in P0 NS. E11.5 NS expressed a putative Neogenin ligand, RGMa, and underwent apoptosis when exposed to a ligand-blocking antibody. CONCLUSIONS/SIGNIFICANCE: There are fundamental differences between the continuously self-renewing and more limited progenitors of the developing cortex. We identified a subset of differentially expressed proteins that serve not only as a set of functionally important proteins, but as a useful set of markers for the subsequent analysis of NSPC. Neogenin is associated with the continuously self-renewing and neurogenic cells present in E11.5 cortical and adult SVZ NS, and the Neogenin/RGMa receptor/ligand pair may regulate cell survival during development.

Neurosphere formation is an independent predictor of clinical outcome in malignant glioma.

Renewable neurosphere formation in culture is a defining characteristic of certain brain tumor initiating cells. This retrospective study was designed to assess the relationship among neurosphere formation in cultured human glioma, tumorigenic capacity, and patient clinical outcome. Tumor samples were cultured in neurosphere conditions from 32 patients with glioma, including a subpopulation of 15 patients with primary glioblastoma. A subsample of renewable neurosphere cultures was xenografted into mouse brain to determine if they were tumorigenic. Our study shows that both renewable neurosphere formation and tumorigenic capacity are significantly associated with clinical outcome measures. Renewable neurosphere formation in cultured human glioma significantly predicted an increased hazard of patient death and more rapid tumor progression. These results pertained to both the full population of glioma and the subpopulation of primary glioblastoma. Similarly, there was a significant hazard of progression for patients whose glioma had tumorigenic capacity. Multivariate analysis demonstrated that neurosphere formation remained a significant predictor of clinical outcome independent of Ki67 proliferation index. In addition, multivariate analysis of neurosphere formation, tumor grade and patient age, demonstrated that neurosphere formation was a robust, independent predictor of glioma tumor progression. Although the lengthy duration of this assay may preclude direct clinical application, these results exemplify how neurosphere culture serves as a clinically relevant model for the study of malignant glioma. Furthermore, this study suggests that the ability to propagate brain tumor stem cells in vitro is associated with clinical outcome.

G418-mediated ribosomal read-through of a nonsense mutation causing autosomal recessive proximal renal tubular acidosis.

Autosomal recessive proximal renal tubular acidosis is caused by mutations in the SLC4A4 gene encoding the electrogenic sodium bicarbonate cotransporter NBCe1-A. The mutations that have been characterized thus far result in premature truncation, mistargeting, or decreased function of the cotransporter. Despite bicarbonate treatment to correct the metabolic acidosis, extrarenal manifestations persist, including glaucoma, cataracts, corneal opacification, and mental retardation. Currently, there are no known therapeutic approaches that can specifically target mutant NBCe1-A proteins. In the present study, we tested the hypothesis that the NBCe1-A-Q29X mutation can be rescued in vitro by treatment with aminoglycoside antibiotics, which are known for their ability to suppress premature stop codons. As a model system, we cloned the NBCe1-A-Q29X mutant into a vector lacking an aminoglycoside resistance gene and transfected the mutant cotransporter in HEK293-H cells. Cells transfected with the NBCe1-A-Q29X mutant failed to express the cotransporter because of the premature stop codon. Treatment of the cells with G418 significantly increased the expression of the full-length cotransporter, as assessed by immunoblot analysis. Furthermore, immunocytochemical studies demonstrated that G418 treatment induced cotransporter expression on the plasma membrane whereas in the absence of G418, NBCe1-A-Q29X was not expressed. In HEK293-H cells transfected with the NBCe1-A-Q29X mutant not treated with G418, NBCe1-A-mediated flux was not detectable. In contrast, in cells transfected with the NBCe1-A-Q29X mutant, G418 treatment induced Na(+)- and HCO(3)(-)-dependent transport that did not differ from wild-type NBCe1-A function. G418 treatment in mock-transfected cells was without effect. In conclusion, G418 induces ribosomal read-through of the NBCe1-A-Q29X mutation in HEK293-H cells. These findings represent the first evidence that in the presence of the NBCe1-A-Q29X mutation that causes proximal renal tubular acidosis, full-length functional NBCe1-A protein can be produced. Our results provide the first demonstration of a mutation in NBCe1-A that has been treated in a targeted and specific manner.