bluuebunny/crossref_metadata_2025 huggingface dataset:
Obesity and steatosis promotes mitochondrial remodeling that enhances respiratory capacity in the liver of ob/ob mice
Authors: Garcia Jerome , Decker Carl W. , Sanchez Silvestre J. , Ouk Jeffrey M. , Siu Krysta M. , Han Derick
Published: February 2018

We investigated if obesity/steatosis promotes mitochondrial remodeling in the liver of ob/ob mice (an obesity model). Liver mitochondria from ob/ob mice (21 weeks with significant steatosis) had ~ 2‐fold increases in state III respiration compared with control (C57BL/6J, C57BL/6NJ) for all respiratory substrates examined (glutamate/malate, succinate, octanoate, and glycerol 3‐phosphate). A corresponding 2‐fold increase in the expression of respiratory complexes (I, IV, and V) and other respiratory proteins (glycerol phosphate dehydrogenase‐2 and medium‐chain acyl‐coenzyme A dehydrogenase) occur in liver mitochondria of mature ob/ob mice. Conversely, respiration in liver mitochondria from young ob/ob mice (6 weeks) does not differ from control with any respiratory substrates examined. Overall, mitochondrial remodeling that enhances respiration increases with obesity/steatosis in the liver of ob/ob mice.
The heme auxotroph Caenorhabditis elegans can cleave the thioether bonds of c‐type cytochromes
Authors: Murphey Annie C. , Mavridou Despoina A. I. , Hodgkin Jonathan , Ferguson Stuart J.
Published: February 2018

Heme is essential and synthesized via highly regulated processes. For this reason, most organisms strive to recycle it or acquire it from their environment. When heme is bound to proteins noncovalently, degradation of the polypeptide is sufficient to release it. However, in some hemoproteins, such as c‐type cytochromes, heme is covalently bound to the protein backbone. We use the heme auxotroph Caenorhabditis elegans to investigate if cytochromes c can be a heme source, and we show that this organism must encode a novel system which specifically cleaves the thioether bonds of c‐type cytochromes. We also find that at limiting heme concentrations, while somatic tissues develop normally the germline fails to proliferate, suggesting the presence of a heme‐sensing checkpoint in C. elegans.
The Role of the New Zealand Plateau in the Tasman Sea Circulation and Separation of the East Australian Current
Authors: Bull Christopher Y. S. , Kiss Andrew E. , van Sebille Erik , Jourdain Nicolas C. , England Matthew H.
Published: February 2018

The East Australian Current (EAC) plays a major role in regional climate, circulation, and ecosystems, but predicting future changes is hampered by limited understanding of the factors controlling EAC separation. While there has been speculation that the presence of New Zealand may be important for the EAC separation, the prevailing view is that the time‐mean partial separation is set by the ocean's response to gradients in the wind stress curl. This study focuses on the role of New Zealand, and the associated adjacent bathymetry, in the partial separation of the EAC and ocean circulation in the Tasman Sea. Here utilizing an eddy‐permitting ocean model (NEMO), we find that the complete removal of the New Zealand plateau leads to a smaller fraction of EAC transport heading east and more heading south, with the mean separation latitude shifting >100 km southward. To examine the underlying dynamics, we remove New Zealand with two linear models: the Sverdrup/Godfrey Island Rule and NEMO in linear mode. We find that linear processes and deep bathymetry play a major role in the mean Tasman Front position, whereas nonlinear processes are crucial for the extent of the EAC retroflection. Contrary to past work, we find that meridional gradients in the basin‐wide wind stress curl are not the sole factor determining the latitude of EAC separation. We suggest that the Tasman Front location is set by either the maximum meridional gradient in the wind stress curl or the northern tip of New Zealand, whichever is furthest north.
Isotopic Evidence for the Evolution of Subsurface Nitrate in the Western Equatorial Pacific
Authors: Lehmann Nadine , Granger Julie , Kienast Markus , Brown Kevin S. , Rafter Patrick A. , Martínez‐Méndez Gema , Mohtadi Mahyar
Published: February 2018

Subsurface waters from both hemispheres converge in the Western Equatorial Pacific (WEP), some of which form the Equatorial Undercurrent (EUC) that influences equatorial Pacific productivity across the basin. Measurements of nitrogen (N) and oxygen (O) isotope ratios in nitrate (δ15NNO3 and δ18ONO3), the isotope ratios of dissolved inorganic carbon (δ13CDIC), and complementary biogeochemical tracers reveal that northern and southern WEP waters have distinct biogeochemical histories. Organic matter remineralization plays an important role in setting the nutrient characteristics on both sides of the WEP. However, remineralization in the northern WEP contributes a larger concentration of the nutrients, consistent with the older “age” of northern thermocline‐depth and intermediate‐depth waters. Remineralization introduces a relatively low δ15NNO3 to northern waters, suggesting the production of sinking organic matter by N2 fixation at the surface—consistent with the notion that N2 fixation is quantitatively important in the North Pacific. In contrast, remineralization contributes elevated δ15NNO3 to the southern WEP thermocline, which we hypothesize to derive from the vertical flux of high‐δ15N material at the southern edge of the equatorial upwelling. This signal potentially masks any imprint of N2 fixation from South Pacific waters. The observations further suggest that the intrusion of high δ15NNO3 and δ18ONO3 waters from the eastern margins is more prominent in the northern than southern WEP. Together, these north‐south differences enable the examination of the hemispheric inputs to the EUC, which appear to derive predominantly from southern hemisphere waters.
Variability in Benthic Exchange Rate, Depth, and Residence Time Beneath a Shallow Coastal Estuary
Authors: Russoniello Christopher J. , Heiss James W. , Michael Holly A.
Published: February 2018

Hydrodynamically driven benthic exchange of water between the water column and shallow seabed aquifer is a significant and dynamic component of coastal and estuarine fluid budgets. Associated exchange of solutes promotes ecologically important chemical reactions, so quantifying benthic exchange rates, depths, and residence times constrains coastal chemical cycling estimates. We present the first combined field, numerical, and analytical modeling investigation of wave‐induced exchange. Temporal variability of exchange was calculated with data collected by instruments deployed in a shallow estuary for 11 days. Differential pressure sensors recorded pressure gradients across the seabed, and up‐ and down‐looking ADCPs recorded currents and pressures to determine wave parameters, surface‐water currents, and water depth. Wave‐induced exchange was calculated (1) directly from differential pressure measurements, and indirectly with an analytical model based on wave parameters from (2) ADCP and (3) wind data. Wave‐induced exchange from pressure measurements and ADCP‐measured wave parameters matched well, but both exceeded wind‐based values. Exchange induced by tidal pumping and current‐bed form interaction—the other primary drivers in shallow coastal waters were calculated from tidal stage variation and ADCP‐measured currents. Exchange from waves (mean = 20.0 cm/d; range = 1.75–92.3 cm/d) greatly exceeded exchange due to tides (mean = 3.7 cm/d) and current‐bed form interaction (mean = 6.5 × 10−2 cm/d). Groundwater flow models showed aquifer properties affect wave‐driven benthic exchange: residence time and depth increased and exchange rates decreased with increasing hydraulic diffusivity (ratio of aquifer permeability to compressibility). This new understanding of benthic exchange will help managers assess its control over chemical fluxes to marine systems.
A new algorithm on the automatic TFT‐LCD mura defects inspection based on an effective background reconstruction
Authors: Ngo Chinh , Park Yong Jin , Jung Jeehyun , Hassan Rizwan Ul , Seok Jongwon
Published: February 2018

In this study, an automatic detection method for mura defects is developed based on an accurate reconstruction of the background and precise evaluation of the mura index level. To achieve this, an effective background reconstruction method is first developed to represent the brightness intensity of the display panel. As a result, any nonuniform brightness of the background can be removed effectively. Furthermore, the associated mura level is quantified based on the sensitivity of the human eye in order to alternatively grade the liquid‐crystal display panels. The main focus of this study is on the reconstruction of the background from the display under test image. The proposed method takes full advantage of the following three existing methods: low‐pass filtering, discrete cosine transform, and polynomial surface fitting. By applying the method to several case studies, we have shown that it is more effective compared with other existing methods in detecting various types of mura defects.
Bidding coordination algorithm with CFC and an emotion switch
Authors: Yao Zhifeng , Ye Xiufen , Dai Xuefeng
Published: February 2018

Exploration is a fundamental problem in robotics, and multi-robot systems exploration has been extensively studied in this field. In order to overcome the problem of a non-optimal target being selected in the exploration process, a revised single linkage clustering frontier cell (CFC) algorithm is proposed to calculate the exploration benefit of all available frontier cells. Moreover, there exist unexplored islands for most of the bidding-based multi-robot coordination algorithms in the exploration of unknown environments. To deal with this problem, some rules switched by emotion states are proposed. So, the proposed bidding coordination algorithm with CFC and an emotion switch has a hierarchical architecture. The upper level is modeled as an automaton, which is used to represent emotion status, and the emotion variables decide whether a robot will participate in a bid and explore an unknown area abiding by the walking rules. In the lower level, the robots perform bidding activities with CFC and the walking rules according to the emotion variables. We tested and evaluated our approach by means of experiments both in a simulated environment and with real robots. The experiments results demonstrate that the exploration efficiency is improved, and our algorithm has a greater coverage rate than classic bidding-based coordination algorithms.
An extremely rare clinical entity: congenitally corrected transposition with situs ınversus and single coronary artery presented with complete atrioventricular block in a young man
Authors: Cirakoglu Omer Faruk , Bayraktar Ali , Sayin Muhammet Rasit
Published: February 2018

Congenitally corrected transposition of the great arteries is a rare form of CHD. Situs inversus is a much less common variant of a congenitally corrected transposition of the great arteries. In rare cases, transposition events may be accompanied by various cardiac anomalies. However, situs inversus patients with congenitally corrected transposition, single coronary artery anomaly, and atrioventricular block together have not been reported previously. This combination of abnormalities is presented as a first in the literature.
GICs: The Bane of Technology-Dependent Societies
Authors: Knipp Delores
Published: February 2018

Geomagnetically Induced Currents can cause voltage swings, transformer heating, and reactive power loss in high-voltage power transmission systems.
Insights into the Ongoing California Drought
Authors: Diffenbaugh Noah
Published: February 2018

Real-time research informs real-time decision-making for addressing the California drought.
AGU Editor Suggestions for Navigating the Fall Meeting, Part I
Authors: Hanson Brooks
Published: February 2018

AGU's journal editors provide suggestions and recommendations of sessions and talks of particular interest.
After the Climate Agreement in Paris
Authors: Brasseur Guy
Published: February 2018

The climate agreement in Paris is an essential multilateral commitment to mitigating the effects of climate change, and the scientific community is key in supporting that commitment.
Challenges in Assembling and Managing Environmental Data Sets
Authors: O'Reilly Catherine , Hampton Stephanie , Sharma Sapna , Gray Derek , Read Jordan , Lenters John , Schneider Philipp
Published: February 2018

Pulling together long-term data is increasingly important in assessing environmental changes, whether regionally or globally.
Understanding the Formation and Primordial Evolution of the Earth
Authors: Badro James , Walter Michael
Published: February 2018

The processes that formed the infant Earth set the stage for its subsequent evolution into the dynamic and habitable planet we know today.
AGU Workshops for Authors and Reviewers
Authors: Hanson Brooks
Published: February 2018

AGU and AGU editors led a number of workshops in 2015 on how to be a successful author to worldwide audiences as well as to how to effectively review scientific papers. First, Yusuke Yokoyama (Editor for Geochemistry, Geophysics, Geosystems) convened a workshop at the JPGU meeting in Tokyo, Japan.
The Proof of Our Science Lies in the Telling
Authors: Sahagian Dork
Published: February 2018

Communicating our science for the benefit of society
Watch Your Language
Authors: Norgaard Richard
Published: February 2018

Legacy words and the search of a new human-environment dynamic
New Insights from 60 Years of Crevasse Research
Authors: Florindo Fabio
Published: February 2018

Deep cracks in the ice may provide insight into glacier decay and help predict sea level rise.
What Are Scientists Doing off the Oregon Coast in Winter?
Authors: Goni Miguel
Published: February 2018

Social media and the value of communicating field experiences to the public
Toward an Understanding of Earth-Affecting Solar Eruptions
Authors: Wang Yuming
Published: February 2018

Coronal mass ejection forecasting improves with technological developments and increasing availability of data.
Frontiers in Geosystems: Solving the Puzzles
Authors: Becker Thorsten
Published: February 2018

Putting some publishing action into deep Earth-surface interactions
Tidal River Dynamics
Authors: Moldwin Mark
Published: February 2018

Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology.
Blowin’ in the Wind: Observing Stratospheric Aerosols
Authors: Robock Alan
Published: February 2018

New observations and understanding of stratospheric particles are crucial for evaluating their role in climate change.
Loss of hamster Leydig cells during regression after exposure to a short photoperiod
Authors: Beltrán-Frutos E. , Seco-Rovira V. , Martínez-Hernández J. , Ferrer C. , Pastor L. M.
Published: February 2018

The aim of the present study was to evaluate the changes that occur in hamster Leydig cells during regression. Animals were divided into control, mild regression (MR), strong regression (SR) and total regression (TR) groups. Leydig cells were characterised by light and electron microscopy. Terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL) and proliferating cell nuclear antigen (PCNA) antibodies were used to detect apoptosis and proliferation respectively. Three types of Leydig cells (A, B and C) could be differentiated. Type A cells were small in size compared with Leydig cells from animals exposed to a long photoperiod, which was a result of a decreased cytoplasm and nucleus. Type B cells were even smaller than Type A cells in regression groups. Type C exhibited cytoplasm vacuolisation. The percentage of Type C cells from the control group was much lower than in the MR, SR and TR groups. (P < 0.05). In the SR and TR groups, there was a significant decrease in the percentage of Type B cells compared with the control and MR groups (P < 0.05). The total number of Leydig cells decreased during testicular regression (P < 0.05). The total number of Type A and B cells was significantly lower in the MR, SR and TR groups compared with the control group (P < 0.05). There were no significant differences in the proliferation and apoptosis index in the groups studied. The findings of the present study indicate that there are three types of Leydig cells (A, B and C) in all hamsters studied and that regression causes an increase in the number of Type C cells, so that the reduction in the number Leydig cells during the phases of regression studied must be the result of necrosis and/or necroptosis.
Quality of Life in People With Severe Dementia and Its Association With the Environment in Nursing Homes: An Observational Study
Authors: Palm Rebecca , Trutschel Diana , Sorg Christian G G , Dichter Martin N , Haastert Burkhard , Holle Bernhard
Published: February 2018

Background and Objectives

Theoretical models propose the environment as a factor influencing the quality of life (QoL) of nursing home residents with dementia. This study investigates whether the observed QoL differs depending on the type of care unit.

Research Design and Methods

DemenzMonitor is an exploratory, observational study involving annual data collection in German nursing homes (2012–2014). For this analysis, we selected residents with a recorded diagnosis of dementia and severe cognitive impairment. QoL was measured with the proxy assessment QUALIDEM. Four care unit types were investigated: large integrated, large segregated, small integrated, and small segregated.

Results

We did not find a significant difference between the care units. During the 2 years, the observed QoL was not affected by any of the care unit types in a statistically significant or clinically relevant manner. However, a significant interaction effect between time and care unit types was found.

Discussion and Implications

Structural and organizational characteristics of care units, which in turn have implications for residents characteristics and the quality of care, may influence the QoL of residents. This may explain the interaction we observed.
Safety of Laser Interstitial Thermal Therapy in Patients With Pacemakers
Authors: Grewal Sanjeet S , Gorny Krzysztof R , Favazza Christopher P , Watson Robert E , Kaufmann Timothy J , Van Gompel Jamie J
Published: February 2018

BACKGROUND AND IMPORTANCE

Laser interstitial thermal therapy (LiTT) has increasingly been used as a treatment option for medically refractory epilepsy, tumors, and radiation necrosis. The use of LiTT requires intraoperative magnetic resonance (MR) thermography. This can become an issue in patients with other implanted therapeutic devices such as pacemakers and vagal nerve stimulators due to concerns regarding increases in the specific absorption rate (SAR). This is a technical case report demonstrating a successfully and safely performed LiTT in a 1.5-T magnetic resonance imaging (MRI) in a patient with a pacemaker for mesial temporal sclerosis.

CLINICAL PRESENTATION

An 83-yr-old gentleman who had an implanted cardiac pacemaker presented with medically intractable epilepsy and was confirmed to have mesial temporal sclerosis on imaging. Video electroencephalography demonstrated concordant ipsilateral seizures and semiology. He underwent LiTT for ablation of the mesial temporal lobe. This was performed with the below described protocol with a cardiology nurse monitoring the patient's cardiac condition and a physicist monitoring SAR, and MR imaging quality without any adverse events.

CONCLUSION

This study reports on a protocol of cardiac and MR SAR to safely perform MR-guided LiTT in the setting of traditional pacemakers in patients who are not pacemaker dependent.
The Utility of Vancomycin Powder in Reducing Surgical Site Infections in Deep Brain Stimulation Surgery
Authors: Kochanski Ryan B , Nazari Pouya , Sani Sepehr
Published: February 2018

BACKGROUND

The impact of vancomycin powder on reducing postoperative surgical site infections (SSIs) in spine surgery has been studied extensively and is considered standard of care at many institutions. More recently, vancomycin powder has been shown to reduce SSI in cranial neurosurgery; however, limited studies have been performed assessing its impact in reducing SSIs in deep brain stimulation (DBS) surgery.

OBJECTIVE

To investigate the use of vancomycin powder as an adjunct to the current antibiotic prophylaxis regimen in DBS surgery in a large cohort of patients.

METHODS

All patients undergoing DBS-lead implantation surgery and chest generator placement or exchange were analyzed prior to and after the implementation of intrawound vancomycin powder, and the impact on infection rate and any complications were subsequently examined.

RESULTS

From 2015 to 2017, a total of 419 consecutive patients (159 in the pretreatment group, 260 in the post-treatment group) were included in the study. The rate of SSI prior to implementation of intrawound vancomycin was 3.1% (n = 5), which was reduced to 0.38% (n = 1) in the post-treatment group. No complications were noted as a direct result of using vancomycin powder.

CONCLUSION

Given its relatively low cost and side effect profile, the use of vancomycin powder may be an effective adjunct in reducing the rate of SSI in DBS surgery.
Nurse Educator Attitudes Toward People With Disabilities
Authors: Lyon Lori , Houser Rick
Published: February 2018

AIM

As educators strongly influence the attitudes of their students, the purpose of this study was to determine nurse educator attitudes toward people with disabilities.

BACKGROUND

Inadequate education of health professionals is a known barrier to care for people with disability. Continuing calls for improved education of health professionals compel an assessment of nurse educator attitudes.

METHOD

This was a cross-sectional, correlational web-based survey of nurse educators (n = 126). Nurse educator attitudes were analyzed using descriptive statistics, analysis of variance, and multiple regression analysis.

RESULTS

Nurse educators held discriminatory attitudes toward people with disabilities, though most preferred a biopsychosocial model of disability. Forty-four percent lacked knowledge of disability-related aims, objectives, or outcomes within the curriculum.

CONCLUSION

To advance equity in health care, nurse educators must confront personal bias and teach competent care of people with disabilities.
Examination of Utricular Response Using oVEMP and Unilateral Centrifugation Rotation Testing
Authors: Zalewski Christopher K. , Ackley R. Steven , McCaslin Devin L. , Clark M. Diane , Hanks Wendy D. , Brewer Carmen C.
Published: February 2018

Objectives:

Significant advancements have been made toward the clinical assessment of utricular function through ocular vestibular-evoked myogenic potentials (oVEMP) and unilateral centrifugation (UCF) testing. To date, no study has examined intrasubject relationships between these measures. The study hypothesis was that intrasubject responses from oVEMP and UCF testing would be correlated inasmuch as both tests have been reported to assess utricular function.

Design:

UCF rotations and oVEMP testing were performed on healthy volunteers, aged 18 to 62 years. A within-subject study design compared and correlated UCF outcome measures of ocular counterroll, subjective visual vertical, and ocular counterroll–gravitational inertial acceleration slope against peak to peak oVEMP N1–P1 amplitude.

Results:

Correlational analyses failed to reveal any significant relationships between oVEMP amplitude and UCF responses suggesting that these tests may be inciting different response properties within the utricular system.

Conclusions:

Various anatomical and physiological differences within the utricle, in addition to the fundamental differences in stimulus properties between the oVEMP and UCF tests, could explain the lack of significant correlations between these measures and suggest that oVEMP and UCF testing may be complimentary in their evaluation of the utricular system. These data reinforce the complexities of the utricular system and provide further insight into the difficulties encountered in its clinical assessment.
Extra-pulmonary diseases related to Mycoplasma pneumoniae in children: recent insights into the pathogenesis
Authors: Poddighe Dimitri
Published: February 2018

Purpose of review

Providing an overview on Mycoplasma pneumoniae-related extra-pulmonary diseases (MpEPDs) in children, who represent the preferred target population by those complications, and discussing the main pathogenic mechanisms implicated or potentially involved.

Recent findings

Recent evidences supported the fact that M. pneumoniae is more than an extra-cellular pathogen colonizing epithelial cells of the respiratory tract. It is able to penetrate the cell membrane of host cells and to invade the respiratory mucosa, leading to pronounced inflammatory responses and also spreading outside the respiratory system, to some extent. Thus, direct and indirect (immune-mediated) mechanisms have been described in M. pneumoniae infections, but the latter ones have been mainly implicated in MpEPDs, as reviewed here. Recently, interesting insights have been provided, especially as concern neurologic complications, and new potential mechanisms of disease have been emerging for autoimmunity.

The awareness of the occurrence of MpEPDs, showing very variable clinical expressions, could promote a correct diagnosis and an appropriate treatment. The knowledge of disease mechanisms in MpEPDs is largely incomplete, but recent advances from clinical studies and murine models might promote and direct future research.
Acute Compartment Syndrome: An Expert Survey of Orthopaedic Trauma Association Members
Authors: Collinge Cory A. , Attum Basem , Lebus George F. , Tornetta Paul , Obremskey William , Ahn Jaimo , Mirick Gudrun , Schmidt Andrew , Spitler Clay , Coles Chad , Krause Peter ,   the Orthopaedic Trauma Association's Evidence-based Quality and Value Committee
Published: February 2018

Objectives:

The goal of this study was to describe current opinions of orthopaedic trauma experts regarding acute compartment syndrome (ACS).

Design:

Web-based survey.

Participants:

Active Orthopaedic Trauma Association (OTA) members.

Methods:

A 25-item web-based questionnaire was advertised to active members of the OTA. Using a cross-sectional survey study design, we evaluated the perceived importance of ACS, as well as preferences in diagnosis and treatment.

Results:

One hundred thirty-nine of 596 active OTA members (23%) completed the survey. ACS was believed to be clinically important and with severe sequelae, if missed. Responses indicated that diagnosis should be based on physical examination in an awake patient, and that intracompartmental pressure testing was valuable in the obtunded or unconscious patient. The diagnosis of ACS with monitoring should be made using the difference between diastolic blood pressure and intracompartmental pressure (ΔP) of ≤30 mm Hg. Once ACS is diagnosed, respondents indicated that fasciotomies should be performed as quickly as is reasonable (within 2 hours). The consensus for wound management was closure or skin grafting within 1–5 days later, and skin grafting was universally recommended if closure was delayed to >7 days.

Conclusions:

ACS is a challenging problem with poor outcomes if missed or inadequately treated. OTA members demonstrated agreement to many diagnostic and treatment choices for ACS.

Level of Evidence:

Therapeutic Level V. See Instructions for Authors for a complete description of the levels of evidence.
Segmental Tibia Fractures: An Analysis of Complication and Healing Rates
Authors: Corey Robert M. , Park Nathan K. , Cannada Lisa K.
Published: February 2018

Objectives:

To determine the most commonly associated injuries, complications, and healing rates of patients sustaining segmental tibial shaft fractures.

Design:

Retrospective review.

Setting:

Two Level I trauma centers.

Patients:

A total of 108 patients with segmental tibial shaft fractures were identified between 2005 and 2013.

Intervention:

None.

Main Outcome Measures:

Demographics, injury characteristics, treatments, and complications. Categories were evaluated and analyzed based on frequency of occurrence. Time to union was assessed based on serial radiographs.

Results:

A total of 108 patients met the inclusion criteria. All fractures were OTA/AO type 42C2. Seventy-three patients (68%) sustained open fractures. There were 34 patients (31%) who had compartment syndrome. The median Injury Severity Score was 27 (range 4–75). Ninety-five patients underwent reamed intramedullary nailing of the tibia, 4 underwent open reduction internal fixation, and 2 patients were definitively treated with external fixation. The median length of hospital stay was 11 days (range 3–48). Outcome data (time to union/delayed union/malunion) was available for 101 patients. The median time to union was 26 weeks (range 14–48). The delayed union rate was 40% (40/101) and the nonunion rate was 10% (10/101).

Conclusion:

Segmental tibial shaft fractures are often associated with severe polytrauma and are most often open fractures. Reamed intramedullary nailing after appropriate resuscitative and stabilization methods can result in excellent alignment and union in these fractures, with low nonunion and infection rates at 1 year.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Pediatric Supracondylar Humerus Fractures: Does After-Hours Treatment Influence Outcomes?
Authors: Paci Gabrielle M. , Tileston Kali R. , Vorhies John S. , Bishop Julius A.
Published: February 2018

Objective:

To compare the outcomes of pediatric supracondylar humerus fractures treated during daytime hours to those treated after-hours.

Design:

Retrospective.

Setting:

Academic Level I trauma center.

Patients/Participants:

Two hundred ninety-eight pediatric patients treated with surgical reduction and fixation of closed supracondylar fractures were included.

Intervention:

Seventy-seven patients underwent surgery during daytime hours (06:00–15:59 on weekdays). One hundred eighty-six patients underwent surgery after-hours (16:00–05:59 on weekdays and any surgery on weekends or holidays).

Main Outcome Measures:

Surgeon subspecialty, operative duration, and radiographic and clinical outcomes, including range of motion and carrying angle, were extracted from the patient medical records.

Results:

There were no patient-related demographic differences between the daytime hours and after-hours groups. Daytime surgery was more likely to be performed by a pediatric orthopaedic surgeon than after-hours surgery. Fractures treated after-hours had more severe injury patterns. After-hours surgery was not independently associated with rate of open reduction, operative times, complications, achievement of functional range of motion, or radiographic alignment. A late-night surgery subgroup analysis demonstrated an increased rate of malunion in patients undergoing surgery between the hours of 23:00 and 05:59.

Conclusions:

There is no difference in the operative duration or outcomes after surgical treatment of pediatric supracondylar humerus fractures performed after-hours when compared with daytime surgery. However, late-night surgery performed between 23:00 and 05:59 may be associated with a higher rate of malunion. Surgeons can use these data to make better-informed decisions about the timing of surgery in this patient population.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Helical Blade or the Integrated Lag Screws: A Matched Pair Analysis of 100 Patients With Unstable Trochanteric Fractures
Authors: Gavaskar Ashok S. , Tummala Naveen C. , Srinivasan Parthasarathy , Gopalan Hitesh , Karthik Bhupesh , S Santosh
Published: February 2018

Objectives:

To compare the radiological and clinical results with PFNA-II and InterTan in the treatment of unstable trochanteric fractures in the elderly.

Design:

Retrospective, multicenter, matched pair.

Setting:

Three tertiary level trauma centers.

Patients:

Hundred elderly patients who underwent intramedullary stabilization with either the PFNA-II or the InterTan for osteoporotic unstable trochanteric fractures.

Interventions:

Fifty matched pairs consisting of OTA/AO–A2 and A3 fractures were created from a cohort of 290 patients who underwent internal fixation for unstable trochanteric fractures with the PFNA-II or InterTan nails.

Outcome Measurements:

Radiological assessment was performed to compare union rates, varus collapse, medial or lateral screw/blade migration, and cut-out. Functional outcome at 1 year was assessed and compared using Harris hip score, Timed Up and Go test, and the mobility score.

Results:

Union rates, fracture reduction, neck shaft angle, and tip–apex distance were similar in both groups. The PFNA-II group had a significantly higher degree of lateral sliding of the helical blade (P < 0.001). The InterTan group had a better Harris hip score, mobility score, Timed Up and Go test scores, and abductor strength (P < 0.05) at 1 year. The incidence of varus collapse and medial blade migration were higher in the PFNA-II group (P > 0.05). The need for repeat surgery to address surgery-related complications were significantly high in the PFNA-II group (P = 0.045).

Conclusions:

The InterTan may provide superior functional outcome and reduced complications than does the Proximal Femur Nail - Antirotation in elderly patients with unstable trochanteric fractures.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Are Variable-Angle Locking Screws Stable Enough to Prevent Calcaneal Articular Surface Collapse? A Biomechanical Study
Authors: Jordan Martin C. , Fuchs Konrad , Heintel Timo M. , Jansen Hendrik , Hoelscher-Doht Stefanie , Meffert Rainer H.
Published: February 2018

Purpose:

To compare fixed- or variable-angle locking screws in calcaneal fracture plates using a sawbones biomechanical model.

Methods:

Intra-articular calcaneal fractures were created in synthetic bones. Reduction and stabilization was performed with 3 different plates. In group A, a fixed-angle locking plate was used with screws fastened perpendicularly to the plate (3.5 LCP, DePuySynthes). In groups B and C (2.7 VA-LCP, DePuySynthes and 3.5 Aptus, Medartis, respectively), fracture fixation was performed using variable-angle locking plates. Biomechanical testing was conducted. Displacement of the subtalar articular surface, stiffness, maximum displacement, change in the angle of Gissane, and mode of failure under cyclic loading at 200 N, 600 N, and 1000 N (500 cycles each) were determined.

Results:

No statistically significant difference of articular surface dislocation under cyclic loading was detected. The stiffness and maximum displacement did not reveal any disparity as well. The change in the angle of Gissane showed only minor displacement of the articular surface.

Conclusion:

In our study, the resistance of variable-angle locking plates against articular surface displacement was similar to fixed-angle locking screws.
Predicting Likelihood of Surgery Before First Visit in Patients With Back and Lower Extremity Symptoms
Authors: Boden Lauren M. , Boden Stephanie A. , Premkumar Ajay , Gottschalk Michael B. , Boden Scott D.
Published: February 2018

Study Design.

Retrospective analysis of prospectively collected data.

Objective.

To create a data-driven triage system stratifying patients by likelihood of undergoing spinal surgery within 1 year of presentation.

Summary of Background Data.

Low back pain (LBP) and radicular lower extremity (LE) symptoms are common musculoskeletal problems. There is currently no standard data-derived triage process based on information that can be obtained before the initial physician-patient encounter to direct patients to the optimal physician type.

Methods.

We analyzed patient-reported data from 8006 patients with a chief complaint of low back pain and/or LE radicular symptoms who presented to surgeons at a large multidisciplinary spine center between September 1, 2005 and June 30, 2016. Univariate and multivariate analysis identified independent risk factors for undergoing spinal surgery within 1 year of initial visit. A model incorporating these risk factors was created using a random sample of 80% of the total patients in our cohort, and validated on the remaining 20%.

Results.

The baseline 1-year surgery rate within our cohort was 39% for all patients and 42% for patients with LE symptoms. Those identified as high likelihood by the center's existing triage process had a surgery rate of 45%. The new triage scoring system proposed in this study was able to identify a high likelihood group in which 58% underwent surgery, which is a 46% higher surgery rate than in nontriaged patients and a 29% improvement from our institution's existing triage system.

Conclusion.

The data-driven triage model and scoring system derived and validated in this study (Spine Surgery Likelihood-11), significantly improved existing processes in predicting the likelihood of undergoing spinal surgery within 1 year of initial presentation. This triage system will allow centers to more selectively screen for surgical candidates and more effectively direct patients to surgeons or nonoperative spine specialists.

Level of Evidence: 4
Utility of Supine Lateral Radiographs for Assessment of Lumbar Segmental Instability in Degenerative Lumbar Spondylolisthesis
Authors: Tarpada Sandip P. , Cho Woojin , Chen Foster , Amorosa Louis F.
Published: February 2018

Study Design.

Retrospective chart review

Objective.

To determine whether supine lateral radiographs increase the amount of segmental instability visualized in single-level lumbar degenerative spondylolisthesis, when compared to traditional lateral flexion-extension radiographs. We hypothesized that supine radiographs increase the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to flexion-extension.

Summary of Background Data.

Accurate evaluation of segmental instability is critical to the management of lumbar spondylolisthesis. Standing flexion-extension lateral radiographs are routinely obtained, as it is believed to precipitate the forward-backward motion of the segment; however, recent studies with magnetic resonance imaging and computed tomography have shown that the relaxed supine position can facilitate the reduction of the anterolisthesed segment. Here, we show that inclusion of supine lateral radiographs increases the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to traditional lateral radiographs.

Methods.

Supine lateral radiographs were added to the routine evaluation (standing neutral/flexion/extension lateral radiographs) of symptomatic degenerative spondylolisthesis at our institution. In this retrospective study, 59 patients were included. The amount of listhesis was measured and compared on each radiograph: standing neutral lateral (“neutral”), standing flexion lateral (“flexion”), standing extension lateral (“extension”), and supine lateral (“supine”).

Results.

A total of 59 patients (51 women, 8 men), with a mean age of 63.0 years (±9.85 yr) were included. The mean mobility seen with flexion-extension was 5.53 ± 4.11. The mean mobility seen with flexion-supine was 7.83% ± 4.67%. This difference was significant in paired t test (P = 0.00133), and independent of age and body mass index. Maximal mobility was seen between flexion and supine radiographs in 37 patients, between neutral and supine radiographs in 11 cases, and between traditional flexion-extension studies in 11 cases.

Conclusion.

Supine radiograph demonstrates more reduction in anterolisthesis than the extension radiograph. Incorporation of a supine lateral radiograph in place of extension radiograph can improve our understanding of segmental mobility when evaluating degenerative spondylolisthesis.

Level of Evidence: 3
Outcomes Reported After Surgery for Cauda Equina Syndrome
Authors: Srikandarajah Nisaharan , Wilby Martin , Clark Simon , Noble Adam , Williamson Paula , Marson Tony
Published: February 2018

Study Design.

This is a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

Objective.

To assess the outcomes reported in trials and observational studies of surgery for cauda equina syndrome (CES), and to inform the development of a core outcome set.

Summary of Background Data.

Scoping searches revealed that there were inconsistencies in which outcomes were reported and how they were measured in research studies for patients who had undergone surgery for CES.

Methods.

Ovid Medline, Embase, CINAHL Plus, and trial registries were searched from January 1, 1990 to September 30, 2016 with the term “cauda equina syndrome.” Inclusion and exclusion criteria were applied according to study design, diagnosis, procedure, publication date, language, and patient age. Data extracted included demographics, study design, the outcomes reported, and their definition. We also assessed variation in the use of terminology for each outcome domain.

Results.

A total of 1873 articles were identified, of which 61 met the inclusion criteria. Of these, 737 outcomes reported verbatim were categorized into 20 core outcome domains and 12 subdomains with a range of 1 to 141 outcomes per outcome domain or subdomain. The most commonly reported outcomes were bladder function (70.5%), motor function (63.9%), and sensation (50.8%). Significant variation in the terms used for each outcome was documented, for example, bladder function outcome domain had 141 different terms.

Conclusion.

There is significant heterogeneity in outcomes reported for studies after surgery for CES patients. This indicates a clear need for the development of a core outcome set, which has been registered as number 824 on the COMET (Core Outcome Measure in Effectiveness Trials) database.

Level of Evidence: 1
Trends of Incidence and Risk Factors of Ventilator-Associated Pneumonia in Elderly Patients Admitted to French ICUs Between 2007 and 2014*
Authors: Dananché Cédric , Vanhems Philippe , Machut Anaïs , Aupée Martine , Bervas Caroline , L’Hériteau François , Lepape Alain , Lucet Jean-Christophe , Stoeckel Vincent , Timsit Jean-François , Berger-Carbonne Anne , Savey Anne , Bénet Thomas
Published: February 2018

Objectives:

To assess trends and risk factors of ventilator-associated pneumonia according to age, particularly in the elderly admitted to French ICUs between 2007 and 2014.

Design:

Multicenter, prospective French national Healthcare-Associated Infection surveillance network of ICUs (“Réseau REA-Raisin”).

Settings:

Two-hundred fifty six ICUs in 246 settings in France.

Patients:

Included were all adult patients hospitalized greater than or equal to 48 hours in ICUs participating in the network.

Interventions:

Ventilator-associated pneumonia surveillance over time.

Measurements and Main Results:

Overall and multidrug-resistant organism–related ventilator-associated pneumonia incidence rates were expressed per 1,000 intubation days at risk. Age was stratified into three groups: young (18–64 yr old), old (65–74 yr old), and very old (75+ yr old). Age-stratified multivariate mixed-effects Poisson regressions were undertaken to assess trends of ventilator-associated pneumonia incidence over time, with center as the random effect. Ventilator-associated pneumonia risk factors were also evaluated. Of 206,223 patients, 134,510 were intubated: 47.8% were young, 22.3% were old, and 29.9% were very old. Ventilator-associated pneumonia incidence was lower in the very old group compared with the young group (14.51; 95% CI, 16.95–17.70 vs 17.32; 95% CI, 16.95–17.70, respectively, p < 0.001). Methicillin-resistant Staphylococcus aureus and third-generation cephalosporin-resistant Enterobacteriaceae were identified more frequently in very old patients (p < 0.001 and 0.014, respectively). Age-stratified models disclosed that adjusted ventilator-associated pneumonia incidence decreased selectively in the young and old groups over time (adjusted incidence rate ratios, 0.88; 95% CI, 0.82–0.94; p < 0.001 and adjusted incidence rate ratios, 0.95; 95% CI, 0.86–1.04; p = 0.28, respectively). Male gender and trauma were independently associated with ventilator-associated pneumonia in the three age groups, whereas antibiotics at admission was a protective factor. Scheduled surgical ICU and immunodeficiency were risk factors of ventilator-associated pneumonia in the old group (p = 0.003).

Conclusions:

Ventilator-associated pneumonia incidence is lower but did not decrease over time in very old patients compared with young patients.
An Exploratory Reanalysis of the Randomized Trial on Efficacy of Corticosteroids as Rescue Therapy for the Late Phase of Acute Respiratory Distress Syndrome*
Authors: Meduri G. Umberto , Bridges Lisa , Siemieniuk Reed A. C. , Kocak Mehmet
Published: February 2018

Objectives:

In the Acute Respiratory Distress Syndrome Network randomized controlled trial, methylprednisolone treatment was associated with increased return to mechanical ventilation with partial loss of early improvements. We hypothesize a causal relationship between protocol-driven rapid discontinuation of methylprednisolone post extubation and return to mechanical ventilation. To explore this possibility, we investigated the timing that events occurred in each treatment arm during active treatment intervention (efficacy) and after stopping therapy.

Design and Settings:

Retrospective intention-to-treat analysis of multicenter randomized controlled trial.

Patients and Interventions:

Patients were randomized to methylprednisolone (2 mg/kg/d) or placebo (89 vs 91). The target sample size was reduced post hoc and provided 80% power for an optimistic 50% mortality reduction.

Measurements and Main Results:

Findings are reported as methylprednisolone versus placebo. By day 28, fewer patients died before achieving extubation (15.7% vs 25.3% and risk ratio, 0.62; 95% CI, 0.34–1.13), more achieved successful extubation (71.9% vs 49.5% and risk ratio, 1.45; CI, 1.14–1.85), time to successful extubation was shorter (hazard ratio, 2.05; CI, 1.42–2.96), and more were discharged alive from the ICU (65.2% vs 48.3%; risk ratio, 1.35; CI, 1.04–1.75). After treatment discontinuation, more methylprednisolone-treated patients returned to mechanical ventilation (26.6% vs 6.7%; risk ratio, 3.98; CI, 1.24–12.79)—consistent with reconstituted systemic inflammation in the presence of adrenal suppression. Participants returning to mechanical ventilation without reinstitution of methylprednisolone had increased risk of ventilator dependence and mortality. Despite loss of early benefits, methylprednisolone was associated with sizable and significant improvements in all secondary outcomes and reduction in serious complications (shock and severe infections).

Conclusions:

During active intervention, methylprednisolone was safe and effective in achieving disease resolution. Our findings support rapid glucocorticoid discontinuation post extubation as likely cause of disease relapse. Gradual tapering might be necessary to preserve the significant improvements achieved during methylprednisolone administration.