bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Holocene fire–climate relationships of the western San Juan Mountains, Colorado
Authors: Bigio Erica R. , Swetnam Thomas W. , Pearthree Philip A.
Published: October 2017

In recent decades, warming temperatures and severe drought have contributed to large and severe wildfires in the south-western United States. To put current wildfires in a long-term context, we reconstructed fire events with alluvial stratigraphy methods in south-western Colorado, and compared with paleoclimate records over the late Holocene. The chronology of 32 fire-related sedimentation events from six tributary basins was established using 48 radiocarbon dates. Based on deposit characteristics, we found episodes of increased high-severity fire for 2750–2350 cal yr BP (800–400 BCE); 1400–1175 cal yr BP (550–775 CE); 1050–700 cal yr BP (900–1250 CE); and 525–250 cal yr BP (1425–1700 CE). There were peaks in low-severity fires in 2350–2000 cal yr BP (400–50 BCE) and 300–70 cal yr BP (1650–1880 CE). Two of the four episodes of high-severity fire corresponded with multi-decadal droughts, including clusters of extreme drought years. The most recent fire episode was preceded by wetter conditions and decreased frequency of extreme drought years, which facilitated the build-up of fuel loads. However, previous high-severity episodes were not consistently preceded by wetter conditions. Steep slopes and overall rugged terrain were also likely contributing factors to fuel accumulation and high-severity fires. A recent wildfire followed a fire-free interval of greater than 120 years and likely contained more extensive areas of high-severity burned area than fire events over the late Holocene.
Using neurostimulation to understand the impact of pre-morbid individual differences on post-lesion outcomes
Authors: Woollams Anna M. , Madrid Gaston , Lambon Ralph Matthew A.
Published: October 2017

Significance

Data from patients with brain damage have provided unique insights into the neural bases of cognitive function. Yet interpretation of patient data is complicated by the possible influence of pre-morbid individual differences on performance. We addressed this issue by considering the impact of transcranial magnetic stimulation (TMS)-induced “virtual lesions” of the left anterior temporal lobe upon reading performance in healthy individuals who vary in their degree of semantic reliance during reading. TMS only disrupted performance in higher semantic reliance readers. These results establish a direct link between pre-morbid individual differences and post-damage outcomes. Our virtual lesion approach provides a methodology through which the impact of pre-morbid individual differences can be examined and their theoretical implications understood.
Coexpression of NOS2 and COX2 accelerates tumor growth and reduces survival in estrogen receptor-negative breast cancer
Authors: Basudhar Debashree , Glynn Sharon A. , Greer Madison , Somasundaram Veena , No Jae Hong , Scheiblin David A. , Garrido Pablo , Heinz William F. , Ryan Aideen E. , Weiss Jonathan M. , Cheng Robert Y. S. , Ridnour Lisa A. , Lockett Stephen J. , McVicar Daniel W. , Ambs Stefan , Wink David A.
Published: October 2017

Significance

Nitric oxide synthase-2 (NOS2) and cyclooxygenase-2 (COX2) are inflammation-associated enzymes with oncogenic function in breast cancer. We show that crosstalk between NOS2/COX2 promotes aggressive phenotypes and that elevated coexpression of NOS2/COX2 in tumors predict significantly reduced patient survival (33%) when compared with 95% survival of estrogen receptor-negative patients with low NOS2/COX2 tumor expression. In addition, we have identified a tumor subtype-specific mechanism showing involvement of TNFα and/or endoplasmic reticulum stress as key players in this autocrine loop. Importantly, the simultaneous inhibition of NOS2/COX2 significantly reduced tumor growth in a xenograft murine model, suggesting that targeted inhibition of NOS2/COX2 may be therapeutically beneficial.
Assembly of silver Trigons into a buckyball-like Ag
180
nanocage
Authors: Wang Zhi , Su Hai-Feng , Tan Yuan-Zhi , Schein Stan , Lin Shui-Chao , Liu Wei , Wang Shu-Ao , Wang Wen-Guang , Tung Chen-Ho , Sun Di , Zheng Lan-Sun
Published: October 2017

Significance

Here we present a striking outcome from the alliance between chemistry and mathematics in the design, synthesis, and characterization of a silver cage, Ag
180
. In principle, the design replaces each carbon atom of C
60
with a triplet of argentophilicity-bonded silver atoms to produce a 3.4.6.4 (1,1) polyhedron with sixty 3-gons, ninety 4-gons, twelve 5-gons, and twenty 6-gons. Results from mass spectroscopy suggest an assembly mechanism in solution based on such triplets––the Silver-Trigon Assembly Road (STAR). Indeed, the STAR mechanism may be a general synthetic pathway toward even larger silver polyhedral cages. Besides its fundamental appeal, this synthetic cage may be considered for use as a molecular luminescent thermometer.
Gut health in poultry.
Authors: Kogut M. H. , Yin XiaoNan Yin XiaoNan , Yuan JianMin Yuan JianMin , Broom L.
Published: October 2017

Although the gastrointestinal tract is frequently described simply as 'the gut', it is actually made up of: (1) an epithelium; (2) a diverse and robust immune arm, which contains most of the immune cells in the body; and (3) the commensal bacteria, which contain more cells than are present in the entire host organism. Understanding of the crosstalk between ALL of these interrelated components of the gut is what cumulatively makes the gut the basis for the well-being of animals and the motor that drives their performance. Optimal gut health is of vital importance to the performance of production animals and is synonymous in animal production industries with animal health. There does appear to be a direct relationship between animal performance and a 'healthy' gut, there is no clear definition that includes all the physiological functions of the intestinal tract, including nutrient digestion and absorption, host metabolism and energy generation, a stable microbiome, mucus layer development, barrier function and mucosal immune responses. The most basic function of the gut is regulating physiological homeostasis that provides the host the ability to withstand infectious and non-infectious stressors. This review updates our understanding of the interactions between the diverse physiological features of the gut and emphasizes the extent of areas encompassed by gut health and the ability to regulate animal production.
The self-defeating game: how state capacity and policy choice affect political survival
Authors: Gilbreath Dustin , Turmanidze Koba
Published: October 2017

Political science has dedicated extensive attention to the determinants of regime change as well as its relation to state capacity. Less work has focused on incumbent political survival and state capacity. Building on selectorate theory [Bueno De Mesquita et al. 2005. The Logic of Political Survival. Cambridge, MA: MIT Press], we suggest that the chance of the party of the incumbent remaining in office is partially a function of the capacity of the state they hold power over. However, we also hypothesize that state capacity volatility decreases an incumbent’s chances of winning elections. To empirically test these hypotheses, the article uses a cross country statistical analysis complemented by illustrative case studies of policy making from Armenia and Georgia. The analyses support the above two hypotheses, showing that if the incumbent increases state capacity, it increases their chances of staying in office. However, capacity volatility decreases their chances of survival. While Georgian state capacity developed in fits, jumps, and starts, in Armenia state capacity developed at a slow and steady pace for most of its independence. As the aphorism goes, slow and steady wins the race with politicians being thrown out of office in Georgia and the incumbent in Armenia maintaining its power. Based on the article’s analyses, we suggest that a self-defeating game is at work for reformers.
A common mechanism for CFTR potentiators
Authors: Yeh Han-I , Sohma Yoshiro , Conrath Katja , Hwang Tzyh-Chang
Published: October 2017

Cystic fibrosis (CF) is a channelopathy caused by loss-of-function mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a phosphorylation-activated and adenosine triphosphate (ATP)–gated chloride channel. In the past few years, high-throughput drug screening has successfully realized the first US Food and Drug Administration–approved therapy for CF, called ivacaftor (or VX-770). A more recent CFTR potentiator, GLPG1837 (N-(3-carbamoyl-5,5,7,7-tetramethyl-4,7-dihydro-5H-thieno[2,3-c]pyran-2-yl)-1H-pyrazole-3-carboxamide), has been shown to exhibit a higher efficacy than ivacaftor for the G551D mutation, yet the underlying mechanism of GLPG1837 remains unclear. Here we find that despite their differences in potency and efficacy, GLPG1837 and VX-770 potentiate CFTR gating in a remarkably similar manner. Specifically, they share similar effects on single-channel kinetics of wild-type CFTR. Their actions are independent of nucleotide-binding domain (NBD) dimerization and ATP hydrolysis, critical steps controlling CFTR’s gate opening and closing, respectively. By applying the two reagents together, we provide evidence that GLPG1837 and VX-770 likely compete for the same site, whereas GLPG1837 and the high-affinity ATP analogue 2′-deoxy-N6-(2-phenylethyl)-adenosine-5′-O-triphosphate (dPATP) work synergistically through two different sites. We also find that the apparent affinity for GLPG1837 is dependent on the open probability of the channel, suggesting a state-dependent binding of the drug to CFTR (higher binding affinity for the open state than the closed state), which is consistent with the classic mechanism for allosteric modulation. We propose a simple four-state kinetic model featuring an energetic coupling between CFTR gating and potentiator binding to explain our experimental results.
DIEGO: detection of differential alternative splicing using Aitchison’s geometry
Authors: Doose Gero , Bernhart Stephan H , Wagener Rabea , Hoffmann Steve
Published: October 2017

Motivation

Alternative splicing is a biological process of fundamental importance in most eukaryotes. It plays a pivotal role in cell differentiation and gene regulation and has been associated with a number of different diseases. The widespread availability of RNA-Sequencing capacities allows an ever closer investigation of differentially expressed isoforms. However, most tools for differential alternative splicing (DAS) analysis do not take split reads, i.e. the most direct evidence for a splice event, into account. Here, we present DIEGO, a compositional data analysis method able to detect DAS between two sets of RNA-Seq samples based on split reads.

Results

The python tool DIEGO works without isoform annotations and is fast enough to analyze large experiments while being robust and accurate. We provide python and perl parsers for common formats.

Availability and implementation

The software is available at: www.bioinf.uni-leipzig.de/Software/DIEGO.

Supplementary information

Supplementary data are available at Bioinformatics online.
GRASS: semi-automated NMR-based structure elucidation of saccharides
Authors: Kapaev Roman R , Toukach Philip V
Published: October 2017

Motivation

Carbohydrates play crucial roles in various biochemical processes and are useful for developing drugs and vaccines. However, in case of carbohydrates, the primary structure elucidation is usually a sophisticated task. Therefore, they remain the least structurally characterized class of biomolecules, and it hampers the progress in glycochemistry and glycobiology. Creating a usable instrument designed to assist researchers in natural carbohydrate structure determination would advance glycochemistry in biomedical and pharmaceutical applications.

Results

We present GRASS (Generation, Ranking and Assignment of Saccharide Structures), a novel method for semi-automated elucidation of carbohydrate and derivative structures which uses unassigned 13C NMR spectra and information obtained from chromatography, optical, chemical and other methods. This approach is based on new methods of carbohydrate NMR simulation recently reported as the most accurate. It combines a broad diversity of supported structural features, high accuracy and performance.

Availability and implementation

GRASS is implemented in a free web tool available at http://csdb.glycoscience.ru/grass.html.

Supplementary information

Supplementary data are available at Bioinformatics online.
Dealing with time: a career in fish and fisheries
Authors: Morales-Nin Beatriz
Published: October 2017

In this essay, I review my career in fish and fisheries, describing my work in the context of the ideas of the period and how they have changed with time. My experience may be interesting especially for other women from social backgrounds that do not promote competitive careers. The main lessons that I have learned are that to be persistent and ambitious, to associate with top scientist, and good persons too! is rewarding at several levels. Not to try to be the one in the spotlight but to recognize other people merits gives good results in the long run. Moreover, to take risks from time to time and explore new territories, like science administration in my case, helps to reinvent yourself and keep the intellectual interest alive. I would like to encourage young scientists to persevere, be resilient and take, from time to time, risky decisions. Maybe one does not become rich, but the mental challenges, the networking, the travel and the exceptional places and life experiences make you rich in many worthy ways! One does never get bored.
Cranial Chordoma: A New Preoperative Grading System
Authors: Brito da Silva Harley , Straus David , Barber Jason K , Rostomily Robert C , Ferreira Manuel , Sekhar Laligam N
Published: October 2017

BACKGROUND

Chordomas are rare but challenging neoplasms involving the skull base. A preoperative grading system will be useful to identify both areas for treatment and risk factors, and correlate to the degree of resection, complications, and recurrence.

OBJECTIVE

To propose a new grading system for cranial chordomas designed by the senior author. Its purpose is to enable comparison of different tumors with a similar pathology to clivus chordoma, and statistically correlate with postoperative outcomes.

METHODS

The numerical grading system included tumor size, site of the tumor, vascular encasement, intradural extension, brainstem invasion, and recurrence of the tumor either after surgery or radiotherapy with a range of 2 to 25 points; it was used in 42 patients with cranial chordoma. The grading system was correlated with number of operations for resection, degree of resection, number and type of complications, recurrence, and survival.

RESULTS

We found 3 groups: low-risk 0 to 7 points, intermediate-risk 8 to 12 points, and high-risk ≥13 points in the grading system. The 3 groups were correlated with the following: extent of resection (partial, subtotal, or complete; P < .002); number of operative stages to achieve removal (P < .014); tumor recurrence (P = .03); postoperative Karnofsky Performance Status (P < .001); and with successful outcome (P = .005). The grading system itself correlated with the outcome (P = .005).

CONCLUSION

The proposed chordoma grading system can help surgeons to predict the difficulty of the case and know which areas of the skull base will need attention to plan further therapy.
Conventional and Advanced Imaging of Spine Oncologic Disease, Nonoperative Post-treatment Effects, and Unique Spinal Conditions
Authors: Chokshi Falgun H , Law Meng , Gibbs Wende N
Published: October 2017

In this review, we discuss the imaging features of diseases and conditions ranging from neoplastic to nonoperative post-treatment effects to unique conditions of the spine. Additionally, advanced imaging may increase diagnostic certainty in cases where conventional imaging characteristics of benign lesions and malignant pathology are variable.
Vertebral Compression Fracture After Spine Stereotactic Body Radiation Therapy: A Review of the Pathophysiology and Risk Factors
Authors: Faruqi Salman , Tseng Chia-Lin , Whyne Cari , Alghamdi Majed , Wilson Jefferson , Myrehaug Sten , Soliman Hany , Lee Young , Maralani Pejman , Yang Victor , Fisher Charles , Sahgal Arjun
Published: October 2017

BACKGROUND

Vertebral compression fracture (VCF) is a challenging and not infrequent complication observed following spine stereotactic body radiation therapy (SBRT).

OBJECTIVE

To summarize the data from the multiple studies that have been published, addressing the risk and predictive factors for VCF post-SBRT.

METHODS

A systematic literature review was conducted. Studies were selected if they specifically addressed risk factors for post-SBRT VCF in their analyses.

RESULTS

A total of 11 studies were identified, reporting both the risk of VCF post-SBRT and an analysis of risk factors based on univariate and multivariate analysis. A total of 2911 spinal segments were treated with a crude VCF rate of 13.9%. The most frequently identified risk factors on multivariate analysis were: lytic disease (hazard ratio [HR] range, 2.76-12.2), baseline VCF prior to SBRT (HR range, 1.69-9.25), higher dose per fraction SBRT (HR range, 5.03-6.82), spinal deformity (HR range, 2.99-11.1), older age (HR range, 2.15-5.67), and more than 40% to 50% of vertebral body involved by tumor (HR range, 3.9-4.46). In the 9 studies that specifically reported on the use of post-SBRT surgical procedures, 37% of VCF had undergone an intervention (range, 11%-60%).

CONCLUSION

VCF is an important adverse effect following SBRT. Risk factors have been identified to guide the selection of high-risk patients. Evidence-based algorithms with respect to patient selection and intervention are needed.
Treatment Outcomes of A Randomized Trial of Unruptured Brain Arteriovenous Malformation-Eligible Unruptured Brain Arteriovenous Malformation Patients
Authors: Lang Min , Moore Nina Z , Rasmussen Peter A , Bain Mark D
Published: October 2017

BACKGROUND

The guideline for treating unruptured brain arteriovenous malformations (ubAVMs) remains controversial. A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) reported lower risk of stroke or death with conservative management compared to interventional treatment. There were numerous limitations to the study, including short follow-up period and disproportionate number of patients treated with surgery and embolization.

OBJECTIVE

To evaluate whether treatment of ARUBA-eligible patients have acceptable outcomes at our institution.

METHODS

Retrospective analysis was performed on 673 patients with brain AVMs treated at our institution between 2001 and 2014. One hundred five patients were ARUBA eligible and included in the study. Patients were divided into the microsurgery or Gamma Knife Radiosurgery (GKS; Elekta, Stockholm, Sweden) arm depending on their final treatment. Mean follow-up period was 43 mo (range 4-136 mo). Primary outcome was stroke or death.

RESULTS

A total of 8 (7.6%) patients had a stroke or died. The overall risk of stroke or death was 11.4% (5 of 44 patients) for the microsurgery arm and 4.9% (3 of 61 patients) for the GKS arm. The annual rates of stroke or death were 2.1%, 4.0%, and 1.2% for the entire patient cohort, microsurgery arm, and GKS arm, respectively. AVM obliteration rates at the end of the follow-up period were 95.5% and 47.5% for the microsurgery and GKS arms, respectively.

CONCLUSION

We report a lower overall risk of stroke or death in our ARUBA-eligible patients following treatment than ARUBA. Our results suggest that microsurgery and GKS may be appropriate treatments for patients with ubAVM.
Phase I Trial of DNX-2401 for Diffuse Intrinsic Pontine Glioma Newly Diagnosed in Pediatric Patients
Authors: Tejada Sonia , Alonso Marta , Patiño Ana , Fueyo Juan , Gomez-Manzano Candelaria , Diez-Valle Ricardo
Published: October 2017

BACKGROUND

There are no effective treatments for diffuse intrinsic pontine gliomas (DIPGs); these tumors cannot be surgical resected, and diagnosis is based on magnetic resonance imaging. As a result, tumor tissues for molecular studies and pathologic diagnosis are infrequent. New clinical trials are investigating novel medications and therapeutic techniques in an effort to improve treatment of patients with DIPGs.

OBJECTIVE

To determine the safety, tolerability, and toxicity of an oncolytic adenovirus, DNX-2401, injected into the cerebellar peduncle in pediatric subjects with DIPG and to collect tumor samples of this type of tumor.

METHODS

Phase I, single-center, uncontrolled trial. A tumor biopsy will be performed through the cerebellar peduncle, and DNX-2401 will be injected immediately after the biopsy. Standard therapy consisting of radiotherapy and chemotherapy will follow in 2 to 6 wk.

EXPECTED OUTCOMES

Improvement of overall survival and quality of life in patients with DIPG and collection of tumor specimens to study the molecular profiling of these tumors.

DISCUSSION

The aims of this trial are to contribute to the sample collection of DIPG and to offer treatment during the tumor tissue biopsy using the virus. If this virus works as expected, it could kill the tumor cells with no damage to healthy tissue, functioning as a targeted therapy. It is important to note that edema has not been observed with this virus in all trials performed to date. The information obtained through this and other similar studies may be useful for developing or improving new therapies in the battle against DIPG.
Stereotactic Radiosurgery in the Management of Limited (1-4) Brain Metasteses: Systematic Review and International Stereotactic Radiosurgery Society Practice Guideline
Authors: Chao Samuel T , De Salles Antonio , Hayashi Motohiro , Levivier Marc , Ma Lijun , Martinez Roberto , Paddick Ian , Régis Jean , Ryu Samuel , Slotman Ben J , Sahgal Arjun
Published: October 2017

BACKGROUND

Guidelines regarding stereotactic radiosurgery (SRS) for brain metastases are missing recently published evidence.

OBJECTIVE

To conduct a systematic review and provide an objective summary of publications regarding SRS in managing patients with 1 to 4 brain metastases.

METHODS

Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was conducted using PubMed and Medline up to November 2016. A separate search was conducted for SRS for larger brain metastases.

RESULTS

Twenty-seven prospective studies, critical reviews, meta-analyses, and published consensus guidelines were reviewed. Four key points came from these studies. First, there is no detriment to survival by withholding whole brain radiation (WBRT) in the upfront management of brain metastases with SRS. Second, while SRS on its own provides a high rate of local control (LC), WBRT may provide further increase in LC. Next, WBRT does provide distant brain control with less need for salvage therapy. Finally, the addition of WBRT does affect neurocognitive function and quality of life more than SRS alone.

For larger brain metastases, surgical resection should be considered, especially when factoring lower LC with single-session radiosurgery. There is emerging data showing good LC and/or decreased toxicity with multisession radiosurgery.

CONCLUSION

A number of well-conducted prospective and meta-analyses studies demonstrate good LC, without compromising survival, using SRS alone for patients with a limited number of brain metastases. Some also demonstrated less impact on neurocognitive function with SRS alone. Practice guidelines were developed using these data with International Stereotactic Radiosurgery Society consensus.
Esthesioneuroblastoma: A Patterns-of-Care and Outcomes Analysis of the National Cancer Database
Authors: Orton Andrew , Boothe Dustin , Evans Daniel , Lloyd Shane , Monroe Marcus M , Jensen Randy , Shrieve Dennis C , Hitchcock Ying J
Published: October 2017

BACKGROUND

The available literature to guide treatment decision making in esthesioneuroblastoma (ENB) is limited.

OBJECTIVE

To define treatment patterns and outcomes in ENB according to treatment modality using a large national cancer registry.

METHODS

This study is a retrospective cohort analysis of 931 patients with a diagnosis of ENB who were treated with surgery, radiation therapy, and/or chemotherapy in the United States between the years of 2004 and 2012. Log-rank statistics were used to compare overall survival by primary treatment modality. Logistic regression modeling was used to identify predictors of receipt of postoperative radiotherapy (PORT). Cox proportional hazards modeling was used to determine the survival benefit of PORT. Subgroup analyses identified subgroups that derived the greatest benefit of PORT.

RESULTS

Primary surgery was the most common treatment modality (90%) and resulted in superior survival compared to radiation (P < .01) or chemotherapy (P < .01). On multivariate analysis, PORT was associated with decreased risk of death (hazard ratio [HR] 0.53, P < .01). PORT showed a survival benefit in Kadish stage C (HR 0.42, P < .01) and D (HR 0.09, P = .01), but not Kadish A (HR 1.17, P = .74) and B (HR 1.37, P = .80). Patients who received chemotherapy derived greater benefit from PORT (HR 0.22, P < .01) compared with those who did not (HR 0.68, P = .13). Predictors of PORT included stage, grade, extent of resection, and chemotherapy use.

CONCLUSION

Best outcomes were obtained in patients undergoing primary surgery. The benefit of PORT was driven by patients with stages C and D disease, and by those also receiving chemotherapy.
Military Neurosurgery Socioeconomic Data: Benefits, Challenges, and Opportunities
Authors: Menger Richard , Robbins J Will , Bell Randy
Published: October 2017

Military conflict and neurosurgery date back to antiquity. Neurosurgery's development is intimately linked with Harvey Cushing's military experience. Previous papers highlighted unique opportunities and socioeconomic challenges facing military neurosurgeons. Here, we provide objective data from military neurosurgeons surrounding these issues.

Internet survey responses were solicited from current, separated, and retired military neurosurgeons regarding workforce issues and their perception of military neurosurgery.

A total of 80.9% (98/121) of respondents enjoyed their military experience, 63.6% (77/121) were very pleased with their service; 97.4% (114/117) enjoyed treating military patients, and 78.2% (93/119) would recommend military service. Positives included feelings of patriotism (87.4%), development of camaraderie (71.4%), and deployment experience (93.8%).

However, 76.5% of respondents noted concerns regarding military and civilian pay disparity. 37.5% were overwhelmed with administrative responsibilities, and over 50% desired higher case volume.

Multivariate analysis showed those who failed to develop a sense of camaraderie were more likely to be dissatisfied (P = .02). Those still currently serving trended towards dissatisfaction (P = .08), and current military neurosurgeons were only 0.29 times as likely to recommend military service to another neurosurgeon as compared to those who were retired or separated (P < .024).

Service as a military neurosurgeon is an overwhelmingly positive experience but opportunities exist for mechanisms to increase operative case load, reduce administrative responsibilities, and reduce military–civilian income disparity. Addressing these issues is important as current military neurosurgeons were more likely to be dissatisfied with their military experience and less likely to recommend military service to another neurosurgeon.
Thrombolysis is an Independent Risk Factor for Poor Outcome After Carotid Revascularization
Authors: Vellimana Ananth K , Washington Chad W , Yarbrough Chester K , Pilgram Thomas K , Hoh Brian L , Derdeyn Colin P , Zipfel Gregory J
Published: October 2017

BACKGROUND

Thrombolysis is the standard of care for acute ischemic stroke patients presenting in the appropriate time window. Studies suggest that the risk of recurrent ischemia is lower if carotid revascularization is performed early after the index event. The safety of early carotid revascularization in this patient population is unclear.

OBJECTIVE

To evaluate the safety of carotid revascularization in patients who received thrombolysis for acute ischemic stroke.

METHODS

The Nationwide Inpatient Sample database was queried for patients admitted through the emergency room with a primary diagnosis of carotid stenosis and/or occlusion. Each patient was reviewed for administration of thrombolysis, carotid endarterectomy, (CEA) or carotid angioplasty and stenting (CAS). Primary endpoints were intracerebral hemorrhage (ICH), postprocedural stroke (PPS), poor outcome, and in-hospital mortality. Potential risk factors were examined using univariate and multivariate analyses.

RESULTS

A total of 310 257 patients were analyzed. Patients who received tissue plasminogen activator (tPA) and underwent either CEA or CAS had a significantly higher risk of developing an ICH or PPS than patients who underwent either CEA or CAS without tPA administration. The increased risk of ICH or PPS in tPA-treated patients who underwent carotid revascularization diminished with time, and became similar to patients who underwent carotid revascularization without tPA administration by 7 d after thrombolysis. Patients who received tPA and underwent CEA or CAS also had higher odds of poor outcome and in-hospital mortality.

CONCLUSION

Thrombolysis is a strong risk factor for ICH, PPS, poor outcome, and in-hospital mortality in patients with carotid stenosis/occlusion who undergo carotid revascularization. The increased risk of ICH or PPS due to tPA declines with time after thrombolysis. Delaying carotid revascularization in these patients may therefore be appropriate. This delay, however, will expose these patients to the risk of recurrent stroke. Future studies are needed to determine the relative risks of these 2 adverse events.
Topical Vancomycin Reduces Surgical-Site Infections After Craniotomy: A Prospective, Controlled Study
Authors: Mallela Arka N , Abdullah Kalil G , Brandon Cameron , Richardson Andrew G , Lucas Timothy H
Published: October 2017

BACKGROUND

Surgical-site infections (SSIs) are an important cause of morbidity and mortality in neurosurgical patients. Topical antibiotics are one potential method to reduce the incidence of these infections.

OBJECTIVE

To examine the efficacy of topical vancomycin applied within the wound during craniotomy in a large prospective cohort study at a major academic center.

METHODS

Three hundred fifty-five patients were studied prospectively in this cohort study; 205 patients received 1 g of topical vancomycin powder in the subgaleal space while 150 matched control patients did not. Patients otherwise received identical care. The primary outcome variable was SSI rate factored by cohort. Secondary analysis examined cost savings from vancomycin usage estimated from hospital costs associated with SSI in craniotomy patients.

RESULTS

The addition of topical vancomycin was associated with a significantly lower rate of SSI than standard of care alone (0.49% [1/205] vs 6% [9/150], P = .002). Based on the costs of revision surgery for infections, topical vancomycin usage was estimated to save $1367 446 per 1000 craniotomy patients. No adverse reactions occurred.

CONCLUSION

Topical vancomycin is a safe, effective, and cost-saving measure to prevent SSIs following craniotomy. These results have broad implications for standard of care in craniotomy.
Endovascular Treatment of Posterior Cerebral Artery Aneurysms With Flow Diversion: Case Series and Systematic Review
Authors: Wallace Adam N , Grossberg Jonathan A , Almandoz Josser E Delgado , Kamran Mudassar , Roy Anil K , Kayan Yasha , Austin Matthew J , Howard Brian M , Moran Christopher J , Cawley C Michael , Cross DeWitte T , Dion Jacques E , Kansagra Akash P , Osbun Joshua W
Published: October 2017

BACKGROUND

Flow diversion of posterior cerebral artery (PCA) aneurysms has not been widely reported, possibly owing to concerns regarding parent vessel size and branch vessel coverage.

OBJECTIVE

To examine the safety and effectiveness of PCA aneurysm flow diverter treatment.

METHODS

Retrospective review of PCA aneurysms treated with the Pipeline Embolization Device (PED; Medtronic Inc, Dublin, Ireland) at 3 neurovascular centers, including periprocedural complications and clinical and angiographic outcomes. Systematic review of the literature identified published reports of PCA aneurysms treated with flow diversion. Rates of aneurysm occlusion and complications were calculated, and outcomes of saccular and fusiform aneurysm treatments were compared.

RESULTS

Ten PCA aneurysms in 9 patients were treated with the PED. There were 2 intraprocedural thromboembolic events (20%), including 1 symptomatic infarction and 1 delayed PED thrombosis. Eight of 10 patients returned to or improved from their baseline functional status. Complete aneurysm occlusion with parent vessel preservation was achieved in 75% (6/8) of cases at mean follow-up of 16.7 mo. Eleven of 12 (92%) major branch vessels covered by a PED remained patent. Including the present study, systematic review of 15 studies found a complete aneurysm occlusion rate of 88% (30/34) and complication rate of 26% (10/38), including 5 symptomatic ischemic strokes (13%; 5/38). Fusiform aneurysms more frequently completely occluded compared with saccular aneurysms (100% vs 70%; P = .03) but were associated with a higher complication rate (43% vs 9%; P = .06).

CONCLUSION

The safety and effectiveness profile of flow diverter treatment of PCA aneurysms may be acceptable in select cases.
Long-Term Outcome Following Stereotactic Radiosurgery for Glomus Jugulare Tumors: A Single Institution Experience of 20 Years
Authors: Sharma Mayur , Meola Antonio , Bellamkonda Sushma , Jia Xuefei , Montgomery Joshua , Chao Samuel T , Suh John H , Angelov Lilyana , Barnett Gene H
Published: October 2017

BACKGROUND

Glomus jugulare tumors (GJTs) are rare benign tumors, which pose significant treatment challenges due to proximity to critical structures.

OBJECTIVE

To evaluate the long-term clinical and radiological outcome in patients undergoing stereotactic radiosurgery (SRS) for GJTs through retrospective study.

METHODS

Forty-two patients with 43 GJTs were treated using Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) at our institute from 1997 to 2016. Clinical, imaging, and radiosurgery data were collected from an institutional review board approved database.

RESULTS

Most patients were females (n = 35, 83.3%) and median age was 61 yr (range 23-88 yr). Median tumor volume and diameter were 5 cc and 3 cm, respectively, with a median follow-up of 62.3 mo (3.4-218.6 mo). Overall, 20 patients (47.6%) improved clinically and 14 (33.3%) remained unchanged at last follow-up. New onset or worsening of hearing loss was noted in 6 patients (17.2%) after SRS. The median prescription dose to the tumor margin was 15 Gy (12-18 Gy). Median reduction in tumor volume and maximum tumor diameter at last follow-up was 33.3% and 11.54%, respectively. The 5-yr and 10-yr tumor control rates were 87% ± 6% and 69% ± 13%, respectively. There was no correlation between maximum or mean dose to the internal acoustic canal and post-GK hearing loss (P > .05).

CONCLUSION

SRS is safe and effective in patients with GJTs and results in durable, long-term control. SRS has lower morbidity than that associated with surgical resection, particularly lower cranial nerve dysfunction, and can be a first-line management option in these patients.
State of the Art Treatment of Spinal Metastatic Disease
Authors: Barzilai Ori , Fisher Charles G , Bilsky Mark H
Published: October 2017

Treatment paradigms for patients with spine metastases have evolved significantly over the past decade. Incorporating stereotactic radiosurgery into these paradigms has been particularly transformative, offering precise delivery of tumoricidal radiation doses with sparing of adjacent tissues. Evidence supports the safety and efficacy of radiosurgery as it currently offers durable local tumor control with low complication rates even for tumors previously considered radioresistant to conventional radiation. The role for surgical intervention remains consistent, but a trend has been observed toward less aggressive, often minimally invasive, techniques. Using modern technologies and improved instrumentation, surgical outcomes continue to improve with reduced morbidity. Additionally, targeted agents such as biologics and checkpoint inhibitors have revolutionized cancer care, improving both local control and patient survivals. These advances have brought forth a need for new prognostication tools and a more critical review of long-term outcomes. The complex nature of current treatment schemes necessitates a multidisciplinary approach including surgeons, medical oncologists, radiation oncologists, interventionalists, and pain specialists. This review recapitulates the current state-of-the-art, evidence-based data on the treatment of spinal metastases, integrating these data into a decision framework, NOMS, which integrates the 4 sentinel decision points in metastatic spine tumors: Neurologic, Oncologic, Mechanical stability, and Systemic disease and medical co-morbidities.
Decision Making in the Wait-and-Scan Approach for Vestibular Schwannomas: Is There a Price to Pay in Terms of Hearing, Facial Nerve, and Overall Outcomes?
Authors: Prasad Sampath Chandra , Patnaik Uma , Grinblat Golda , Giannuzzi Annalisa , Piccirillo Enrico , Taibah Abdelkader , Sanna Mario
Published: October 2017

BACKGROUND

The wait-and-scan modality has emerged as an important strategy in the management of vestibular schwannoma (VS) as it has been demonstrated that many tumors grow slowly or do not show any growth over long periods.

OBJECTIVE

To analyze long-term outcomes of wait-and-scan in the treatment of patients with VS, discuss the factors contributing to the decision making, determine the inherent risks of the policy, and compare our results with literature.

METHODS

In total, 576 patients with sporadic unilateral VS who were managed with wait-and-scan were reviewed retrospectively. Of these, a subset of 154 patients with 5-yr follow-up was separately analyzed. The tumor characteristics including patterns of growth, rate of growth, hearing outcomes, and likely factors affecting the above parameters were analyzed.

RESULTS

The mean period of follow-up was 36.9 ± 30.2 mo. The mean age was 59.2 ± 11.6 yr. Thirteen different patterns of tumor growth were observed. Eighty-four (54.5%) of 154 tumors with 5-yr follow-up showed no growth throughout 5 yr. Fifty-six (36.4%) tumors showed mixed growth rates. Only 57 (37%) patients had serviceable hearing at the start of follow-up, but 32 (56.1%) maintained it at the end of follow-up. One hundred fifty (26%) of the 576 patients who failed wait-and-scan had to be taken up for surgery.

CONCLUSION

While there may be no price to pay in wait-and-scan as far as hearing is concerned, this may not be the case for facial nerve outcomes, wherein the results may be better if the patients are taken earlier for surgery.
Adult Craniopharyngioma: Case Series, Systematic Review, and Meta-Analysis
Authors: Dandurand Charlotte , Sepehry Amir Ali , Asadi Lari Mohammad Hossein , Akagami Ryojo , Gooderham Peter
Published: October 2017

BACKGROUND

The optimal therapeutic approach for adult craniopharyngioma remains controversial. Some advocate for gross total resection (GTR), while others advocate for subtotal resection followed by adjuvant radiotherapy (STR + XRT).

OBJECTIVE

To conduct a systematic review and meta-analysis assessing the rate of recurrence in the follow-up of 3 yr in adult craniopharyngioma stratified by extent of resection and presence of adjuvant radiotherapy.

METHODS

MEDLINE (1946-July 1, 2016) and EMBASE (1980-June 30, 2016) were systematically reviewed. From1975 to 2013, 33 patients were treated with initial surgical resection for adult onset craniopharyngioma at our center and were reviewed for inclusion in this study.

RESULTS

Data from 22 patients were available for inclusion as a case series in the systematic review. Eligible studies (n = 21) were identified from the literature in addition to a case series of our institutional experience. Three groups were available for analysis: GTR, STR + XRT, and STR. The rates of recurrence were 17%, 27%, and 45%, respectively. The risk of developing recurrence was significant for GTR vs STR (odds ratio [OR]: 0.24, 95% confidence interval [CI]: 0.15-0.38) and STR + XRT vs STR (OR: 0.20, 95% CI: 0.10-0.41). Risk of recurrence after GTR vs STR + XRT did not reach significance (OR: 0.63, 95% CI: 0.33-1.24, P = .18).

CONCLUSION

This is the first and largest systematic review focusing on the rate of recurrence in adult craniopharyngioma. Although the rates of recurrence are favoring GTR, difference in risk of recurrence did not reach significance. This study provides guidance to clinicians and directions for future research with the need to stratify outcomes per treatment modalities.
Distribution, cycling and impact of water in the Earth's interior
Authors: Ni Huaiwei , Zheng Yong-Fei , Mao Zhu , Wang Qin , Chen Ren-Xu , Zhang Li
Published: October 2017

The Earth's deep interior is a hidden water reservoir on a par with the hydrosphere that is crucial for keeping the Earth as a habitable planet. In particular, nominally anhydrous minerals (NAMs) in the silicate Earth host a significant amount of water by accommodating H point defects in their crystal lattices. Water distribution in the silicate Earth is highly heterogeneous, and the mantle transition zone may contain more water than the upper and lower mantles. Plate subduction transports surface water to various depths, with a series of hydrous minerals and NAMs serving as water carriers. Dehydration of the subducting slab produces liquid phases such as aqueous solutions and hydrous melts as a metasomatic agent of the mantle. Partial melting of the metasomatic mantle domains sparks off arc volcanism, which, along with the volcanism at mid-ocean ridges and hotspots, returns water to the surface and completes the deep water cycle. There appears to have been a steady balance between hydration and dehydration of the mantle at least since the Phanerozoic. Earth's water probably originates from a primordial portion that survived the Moon-forming giant impact, with later delivery by asteroids and comets. Water could play a critical role in initiating plate tectonics. In the modern Earth, the storage and cycling of water profoundly modulates a variety of properties and processes of the Earth's interior, with impacts on surface environments. Notable examples include the hydrolytic weakening effect on mantle convection and plate motion, influences on phase transitions (on the solidus of mantle peridotite in particular) and dehydration embrittlement triggering intermediate- to deep-focus earthquakes. Water can reduce seismic velocity and enhance electrical conductivity, providing remote sensing methods for water distribution in the Earth's interior. Many unresolved issues around the deep water cycle require an integrated approach and concerted efforts from multiple disciplines.
Perceptions of Risk and Safety in the ICU: A Qualitative Study of Cognitive Processes Relating to Staffing*
Authors: D’Lima Danielle M. , Murray Eleanor J. , Brett Stephen J.
Published: October 2017

Objectives:

The aims of this study were to 1) examine individual professionals’ perceptions of staffing risks and safe staffing in intensive care and 2) identify and examine the cognitive processes that underlie these perceptions.

Design:

Qualitative case study methodology with nurses, doctors, and physiotherapists.

Setting:

Three mixed medical and surgical adult ICUs, each on a separate hospital site within a 1,200-bed academic, tertiary London hospital group.

Subjects:

Forty-four ICU team members of diverse professional backgrounds and seniority.

Interventions:

None.

Main Results:

Four themes (individual, team, unit, and organizational) were identified. Individual care provision was influenced by the pragmatist versus perfectionist stance of individuals and team dynamics by the concept of an “A” team and interdisciplinary tensions. Perceptions of safety hinged around the importance of achieving a “dynamic balance” influenced by the burden of prevailing circumstances and the clinical status of patients. Organizationally, professionals’ risk perceptions affected their willingness to take personal responsibility for interactions beyond the unit.

Conclusions:

This study drew on cognitive research, specifically theories of cognitive dissonance, psychological safety, and situational awareness to explain how professionals’ cognitive processes impacted on ICU behaviors. Our results may have implications for relationships, management, and leadership in ICU. First, patient care delivery may be affected by professionals’ perfectionist or pragmatic approach. Perfectionists’ team role may be compromised and they may experience cognitive dissonance and subsequent isolation/stress. Second, psychological safety in a team may be improved within the confines of a perceived “A” team but diminished by interdisciplinary tensions. Third, counter intuitively, higher “situational” awareness for some individuals increased their stress and anxiety. Finally, our results suggest that professionals have varying concepts of where their personal responsibility to minimize risk begins and ends, which we have termed “risk horizons” and that these horizons may affect their behavior both within and beyond the unit.