Citations

Hyperoxia can cause substantial reductions in peripheral and coronary blood flow at rest and during exercise, which may be caused by reactive oxygen species (ROS) generated during hyperoxia. The aim of this study was to investigate the role of ROS in hyperoxia-induced reductions in skeletal muscle blood flow during forearm exercise. We hypothesized that infusion of vitamin C would abolish the effects of hyperoxia on the forearm blood flow (FBF) responses to exercise. Twelve young healthy adults performed rhythmic forearm handgrip exercise (10% of maximum voluntary contraction for 5 min) during normoxia and hyperoxia. For each condition, two trials were conducted with intra-arterial administration of saline or vitamin C. FBF was measured using Doppler ultrasound. During hyperoxia with saline, FBF and forearm vascular conductance (FVC) were 86.3 ± 5.1 and 86.8 ± 5.2%, respectively, of the normoxic values (100%) ( P < 0.05). During vitamin C, hyperoxic FBF and FVC responses were 90.9 ± 4.2 and 90.9 ± 4.1%, respectively, of the normoxic values ( P = 0.57 and 0.59). Subjects were then divided into three subgroups based on their percent decrease in FBF (>20, 10–20, and <10%) during hyperoxia. In the subgroup that demonstrated the greatest hyperoxia-induced changes (>20%), FBF and FVC during hyperoxia were 67.1 ± 4.0 and 66.8 ± 3.6%, respectively, of the normoxic values. Vitamin C abolished these effects on FBF and FVC with values that were 102.0 ± 5.2 and 100.8 ± 6.1%, respectively. However, vitamin C had no effect in the other two subgroups. This analysis is consistent with the idea that ROS generation blunts the FBF responses to exercise in the subjects most affected by hyperoxia.

Objective— Endothelial dysfunction is an early manifestation of atherosclerosis. Inflammation and vasa vasorum play a pivotal role in the pathophysiology of plaque initiation, development, and complications. Optical coherence tomography allows high-resolution imaging of tissue microstructure. Therefore, the aim of this study was to test the hypothesis that segments with endothelial dysfunction show macrophages and vasa vasorum in patients with early coronary artery disease. Approach and Results— Optical coherence tomography images were obtained from 40 patients with mild coronary atherosclerosis who underwent coronary endothelial function assessment. Optical coherence tomography findings, including macrophages and microchannels, were evaluated in 76 coronary segments corresponding to those in endothelial response to acetylcholine. Coronary artery diameter change in response to acetylcholine was more severe in segments showing macrophages (−17.7±14.7% versus −6.3±13.9%; P <0.01) and microchannels (−15.9±15.9% versus −6.4±13.5%; P <0.01) than those without. There were increasing trends of the prevalence of macrophages and microchannels with endothelial dysfunction as stratified by quartiles of coronary artery diameter change ( P <0.01 and P =0.02 for trend, respectively). In particular, segments with both macrophages and microchannels (n=12) tended to have worse endothelial function than those with macrophages alone (n=15) and microchannels alone (n=15; −22.1±14.6% versus −10.9±15.6% and −10.9±15.6%; P =0.07 and P =0.06, respectively). Conclusions— Epicardial endothelial dysfunction was associated with optical coherence tomography –identified macrophages and microchannels in mild coronary atherosclerosis. The current study further supports the role of inflammation and vasa vasorum proliferation in the early stage of coronary atherosclerosis.

Key PointsHCT recipients have increased susceptibility to herpes zoster, but live-attenuated vaccines are not appropriate for highly immunocompromised people. An adjuvanted subunit vaccine against herpes zoster elicits strong immune responses with an acceptable safety profile in adult autologous HCT recipients.

AbstractBackgroundAdenosine signaling has been implicated in several neurological and psychiatric disorders. Previously, we found that astrocytic excitatory amino acid transporter 2 (EAAT2) and aquaporin 4 (AQP4) are downregulated in the striatum of mice lacking type 1 equilibrative nucleoside transporter (ENT1).MethodsTo further investigate the gene expression profile in the striatum, we preformed Illumina Mouse Whole Genome BeadChip microarray analysis of the caudate–putamen (CPu) and nucleus accumbens (NAc) inENT1 null mice. Gene expression was validated byRT‐PCR, Western blot, and immunofluorescence. Using transgenic mice expressing enhanced green fluorescence protein (EGFP) under the control of the glial fibrillary acidic protein (GFAP) promoter, we examinedEGFPexpression in anENT1 null background.ResultsGlial fibrillary acidic protein was identified as a top candidate gene that was reduced in ENT1 null mice compared to wild‐type littermates. Furthermore, EGFP expression was significantly reduced in GFAP‐EGFP transgenic mice in an ENT1 null background in both the CPu and NAc. Finally, pharmacological inhibition or siRNA knockdown of ENT1 in cultured astrocytes also reduced GFAPmRNAlevels.ConclusionsOverall, our findings demonstrate thatENT1 regulatesGFAPexpression and possibly astrocyte function.

Abstract Advances in surgical procedures and improvements in patient outcomes have resulted from applications of new technologies in the operating room over the past three decades. All surgeons would be excited about the possibilities of improving their resections of tumors for patients with cancer if a new technology were introduced to facilitate this. In this issue of ACS Nano, Karabeber et al. use a hand-held Raman scanner to probe the completeness of resection of glioblastoma multiforme (GBM), the most malignant brain cancer, in a genetically engineered mouse model. They show that the hand-held scanner could accurately detect gold–silica surface-enhanced Raman scattering nanoparticles embedded within the GBM, resulting in a complete tumor resection. In this Perspective, we review potential applications of nanotechnologies to neurosurgery and describe how new systems, such as the one described in this issue, may be brought closer to the operating room through modifications in nanoparticle size, overcoming the obstacles presented by the blood–brain barrier, and functionalizing nanoparticle conjugates so that they reach their target at highest concentrations possible. Finally, with adaptations of the actual hand-held Raman scanner device itself, one can envision the day when “nanosurgical” procedures will be a part of the surgeon’s armamentarium.

ABSTRACTBACKGROUND AND PURPOSERequests for after‐hours emergent spine MR imaging seem to be increasing. We sought to review the trend in after hours spine MRI utilization at our institution and to determine how these results impacted therapeutic intervention.METHODSFollowing Institutional Review Board approval, reports from 179 after hours spinal MRI's performed over the past 13 years were obtained and the relevant electronic medical records were reviewed.RESULTSEmergent after hours spine MRI utilization increased from 7 per year to 23 over 13 years. Fifty‐eight percent (104/179) had significant findings. Twenty‐nine percent (52/179) of all patients imaged underwent surgery to treat pathologies identified on MR. Surgery was performed in only 2% (4/179) of these patients within 3 hours and 6% (10/179) within 6 hours of MRI completion. Five percent (8/179) had findings that were treated with radiation therapy and in 78% of these it was performed within 6–12 hours. Of those in whom steroids or antibiotics were initiated, 41% and 50% were treated within 3 hours of MR scanning, respectively.DISCUSSIONClinical use of emergent after hours spine MRI is steadily increasing at our institution. While MR imaging often discerned significant pathologies, performing these emergent studies rarely resulted in immediate surgical or radiotherapeutic intervention.

Abstract Purpose: To establish the concept of minimum clinically meaningful outcome (mCMO) of treatment in advanced solid tumors, to establish its threshold and evaluate how many superiority trials of new antineoplastic agents pass this threshold. Experimental Design: We chose overall survival as the primary indicator of patient benefit. Four conceptually different types of treatment effect can be identified in OS curves: HR, gains in median OS, proportional, and absolute increases at long-term OS. We postulated threshold levels for these four parameters defining the mCMO and set the bar at three different levels of required benefit: high, medium, and low. The postulated values were then studied by comparing our thresholds with the actual results of the pivotal superiority phase III trials on new drugs reporting on mature OS data. Results: Forty-three trials on 35,419 patients in 12 cancer types on 23 novel agents met these criteria. Only two trials reached the postulated “high” thresholds for HR and median OS. The number of “positive trials” increased to eight and 15 when the bar was lowered to the “medium” and “low” levels, respectively. The same analysis was done for proportional and absolute increases in long-term OS. No trial satisfied the criteria for long-term benefit, whereas only two and nine trials satisfied both parameters for the “medium and low” required benefit levels, respectively. Conclusions: All four OS-related parameters contribute to define the mCMO. If the bar for the mCMO is raised too much, positive trials are exceptional. Clin Cancer Res; 21(5); 1036–43. ©2014 AACR. See related commentary by Schilsky, p. 947