Citations

AbstractBoth traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) are common problems resulting from military service, and both have been associated with increased risk of cognitive decline and dementia resulting from Alzheimer's disease (AD) or other causes. This study aims to use imaging techniques and biomarker analysis to determine whether traumatic brain injury (TBI) and/or PTSD resulting from combat or other traumas increase the risk for AD and decrease cognitive reserve in Veteran subjects, after accounting for age. Using military and Department of Veterans Affairs records, 65 Vietnam War veterans with a history of moderate or severe TBI with or without PTSD, 65 with ongoing PTSD without TBI, and 65 control subjects are being enrolled in this study at 19 sites. The study aims to select subject groups that are comparable in age, gender, ethnicity, and education. Subjects with mild cognitive impairment (MCI) or dementia are being excluded. However, a new study just beginning, and similar in size, will study subjects with TBI, subjects with PTSD, and control subjects with MCI. Baseline measurements of cognition, function, blood, and cerebrospinal fluid biomarkers; magnetic resonance images (structural, diffusion tensor, and resting state blood‐level oxygen dependent (BOLD) functional magnetic resonance imaging); and amyloid positron emission tomographic (PET) images with florbetapir are being obtained. One‐year follow‐up measurements will be collected for most of the baseline procedures, with the exception of the lumbar puncture, the PET imaging, and apolipoprotein E genotyping. To date, 19 subjects with TBI only, 46 with PTSD only, and 15 with TBI and PTSD have been recruited and referred to 13 clinics to undergo the study protocol. It is expected that cohorts will be fully recruited by October 2014. This study is a first step toward the design and statistical powering of an AD prevention trial using at‐risk veterans as subjects, and provides the basis for a larger, more comprehensive study of dementia risk factors in veterans.

Abstract B7-H3 is a B7 family molecule with T cell costimulatory function in vitro. The in vivo role of B7-H3 in the stimulation of tumor immunity is unclear. We report here that expression of B7-H3 by transfection of the mouse P815 tumor line enhances its immunogenicity, leading to the regression of tumors and amplification of a tumor-specific CD8+ CTL response in syngeneic mice. Tumor cells engineered to express B7-H3 elicit a rapid clonal expansion of P1A tumor Ag-specific CD8+ CTL in lymphoid organs in vivo and acquire the ability to directly stimulate T cell growth, division, and development of cytolytic activity in vitro. Our results thus establish a role for B7-H3 in the costimulation of T cell immune responses in vivo.

Abstract B7-H4 is a recently identified B7 family member that negatively regulates T cell immunity by the inhibition of T cell proliferation, cytokine production, and cell cycle progression. In this study, we report that the genomic DNA of human B7-H4 is mapped on chromosome 1 comprised of six exons and five introns spanning 66 kb, of which exon 6 is used for alternative splicing to generate two different transcripts. Similar B7-H4 structure is also found in mouse genomic DNA in chromosome 3. A human B7-H4 pseudogene is identified in chromosome 20p11.1 with a single exon and two stop codons in the coding region. Immunohistochemistry analysis using B7-H4-specific mAb demonstrates that B7-H4 is not expressed on the majority of normal human tissues. In contrast, up to 85% (22 of 26) of ovarian cancer and 31% (5 of 16) of lung cancer tissues constitutively express B7-H4. Our results indicate a tight regulation of B7-H4 expression in the translational level in normal peripheral tissues and a potential role of B7-H4 in the evasion of tumor immunity.

Abstract Interaction between dendritic cells (DCs) and T cells is a prerequisite for the initiation of a T cell response. The molecular nature of this interaction remains to be fully characterized. We report in this work that freshly isolated mouse splenic DCs and bone marrow-derived DCs express CD137 on the cell surface and in soluble form. Triggering CD137 increased the secretion of IL-6 and IL-12 from DCs. More importantly, infusion of an agonistic mAb to CD137 into naive mice enhanced the ability of DCs to stimulate T cell proliferation in response to both alloantigens and a nominal Ag in vitro. This enhancement of DC function is not mediated through activation of T cells, because the effect was also observed in RAG-1 knockout mice that lack T cells. Our findings implicate CD137 as an important receptor involved in the modulation of DC function.

Abstract Interaction of 4-1BB (CD137) and its ligand (4-1BBL) is thought to positively regulate cell-mediated and humoral immune responses. We have prepared transgenic mouse strains that express 4-1BBL cDNA under the control of MHC class II I-Eα promoter. The 4-1BBL-transgenic mice show progressive splenomegaly and selective depletion of B220+ B cells accompanied with low levels of circulating IgG and defective humoral responses to Ag challenge. In addition, splenocytes from the transgenic mice fail to provide stimulation for allogeneic T cells in both lymphoproliferative and CTL responses in vitro, whereas their T cells remain functionally normal. Our results reveal unexpected functions of 4-1BBL in the regulation of humoral immune responses and Ag presentation.

Background— Current guidelines recommend coronary artery bypass graft surgery (CABG) when treating significant de novo left main coronary artery (LM) stenosis; however, percutaneous coronary intervention (PCI) has a class IIa indication for unprotected LM disease in selected patients. This analysis compares 5-year clinical outcomes in PCI- and CABG-treated LM patients in the Synergy Between PCI With Taxus and Cardiac Surgery (SYNTAX) trial, the largest trial in this group to date. Methods and Results— The SYNTAX trial randomly assigned 1800 patients with LM or 3-vessel disease to receive either PCI (with TAXUS Express paclitaxel-eluting stents) or CABG. The unprotected LM cohort (N=705) was predefined and powered. Major adverse cardiac and cerebrovascular event rates at 5 years was 36.9% in PCI patients and 31.0% in CABG patients (hazard ratio, 1.23 [95% confidence interval, 0.95–1.59]; P =0.12). Mortality rate was 12.8% and 14.6% in PCI and CABG patients, respectively (hazard ratio, 0.88 [95% confidence interval, 0.58–1.32]; P =0.53). Stroke was significantly increased in the CABG group (PCI 1.5% versus CABG 4.3%; hazard ratio, 0.33 [95% confidence interval, 0.12–0.92]; P =0.03) and repeat revascularization in the PCI arm (26.7% versus 15.5%; hazard ratio, 1.82 [95% confidence interval, 1.28–2.57]; P <0.01). Major adverse cardiac and cerebrovascular events were similar between arms in patients with low/intermediate SYNTAX scores but significantly increased in PCI patients with high scores (≥33). Conclusions— At 5 years, no difference in overall major adverse cardiac and cerebrovascular events was found between treatment groups. PCI-treated patients had a lower stroke but a higher revascularization rate versus CABG. These results suggest that both treatments are valid options for LM patients. The extent of disease should accounted for when choosing between surgery and PCI, because patients with high SYNTAX scores seem to benefit more from surgery compared with those in the lower tertiles. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00114972.

Purpose To evaluate satisfaction with work-life balance (WLB) and career plans of US oncologists. Methods The American Society of Clinical Oncology conducted a survey of US oncologists evaluating satisfaction with WLB and career plans between October 2012 and March 2013. The sample included equal numbers of men and women from all career stages. Results Of 2,998 oncologists contacted, 1,490 (49.7%) returned surveys. From 1,117 oncologists (37.3% of overall sample) completing full-length surveys, we evaluated satisfaction with WLB and career plans among the 1,058 who were not yet retired. The proportion of oncologists satisfied with WLB (n = 345; 33.4%) ranked lower than that reported for all other medical specialties in a recent national study. Regarding career plans, 270 oncologists (26.5%) reported a moderate or higher likelihood of reducing their clinical work hours in the next 12 months, 351 (34.3%) indicated a moderate or higher likelihood of leaving their current position within 24 months, and 273 (28.5%) planned to retire before 65 years of age. Multivariable analyses found women oncologists (odds ratio [OR], 0.458; P < .001) and those who devoted greater time to patient care (OR for each additional hour, 0.977; P < .001) were less likely to be satisfied with WLB. Satisfaction with WLB and burnout were the strongest predictors of intent to reduce clinical work hours and leave current position on multivariable analysis. Conclusion Satisfaction with WLB among US oncologists seems lower than for other medical specialties. Dissatisfaction with WLB shows a strong relationship with plans to reduce hours and leave current practice. Given the pending US oncologist shortage, additional studies exploring interactions among WLB, burnout, and career satisfaction and their impact on career and retirement plans are warranted.

Purpose To evaluate the personal and professional characteristics associated with career satisfaction and burnout among US oncologists. Methods Between October 2012 and March 2013, the American Society of Clinical Oncology conducted a survey of US oncologists evaluating burnout and career satisfaction. The survey sample included equal numbers of men and women and represented all career stages. Results Of 2,998 oncologists contacted, 1,490 (49.7%) returned surveys (median age of respondents, 52 years; 49.6% women). Among the 1,117 oncologists (37.3% of overall sample) who completed full-length surveys, 377 (33.8%) were in academic practice (AP) and 482 (43.2%) in private practice (PP), with the remainder in other settings. Oncologists worked an average of 57.6 hours per week (AP, 58.6 hours per week; PP, 62.9 hours per week) and saw a mean of 52 outpatients per week. Overall, 484 oncologists (44.7%) were burned out on the emotional exhaustion and/or depersonalization domain of Maslach Burnout Inventory (AP, 45.9%; PP, 50.5%; P = .18). Hours per week devoted to direct patient care was the dominant professional predictor of burnout for both PP and AP oncologists on univariable and multivariable analyses. Although a majority of oncologists were satisfied with their career (82.5%) and specialty (80.4%) choices, both measures of career satisfaction were lower for those in PP relative to AP (all P < .006). Conclusion Overall career satisfaction is high among US oncologists, albeit lower for those in PP relative to AP. Burnout rates among oncologists seem similar to those described in recent studies of US physicians in general. Those oncologists who devote the greatest amount of their professional time to patient care seem to be at greatest risk for burnout.