bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of ventilation inhomogeneity during mechanical ventilation using a rapid-response oxygen sensor-based oxygen washout method
Authors: Bikker Ido G , Holland Wim , Specht Patricia , Ince Can , Gommers Diederik
Published: April 2014

Purpose

Ventilatory inhomogeneity indexes in critically ill mechanically ventilated patients could be of importance to optimize ventilator settings in order to reduce additional lung injury. The present study compared six inhomogeneity indexes calculated from the oxygen washout curves provided by the rapid oxygen sensor of the LUFU end-expiratory lung volume measurement system.

Methods

Inhomogeneity was tested in a porcine model before and after induction of acute lung injury (ALI) at four different levels of positive end-expiratory pressure (PEEP; 15, 10, 5 and 0 cm H2O). The following indexes were assessed: lung clearance index (LCI), mixing ratio, Becklake index, multiple breath alveolar mixing inefficiency, moment ratio and pulmonary clearance delay.

Results

LCI, mixing ratio, Becklake index and moment ratio were comparable with previous reported values and showed acceptable variation coefficients at baseline with and without ALI. Moment ratio had the highest precision, as calculated by the variation coefficients. LCI, Becklake index and moment ratio showed comparable increases in inhomogeneity during decremental PEEP steps before and after ALI.

Conclusions

The advantage of the method we introduce is the combined measurement of end-expiratory lung volume (EELV) and inhomogeneity of lung ventilation with the LUFU fast-response medical-grade oxygen sensor, without the need for external tracer gases. This can be combined with conventional breathing systems. The moment ratio and LCI index appeared to be the most favourable for integration with oxygen washout curves as judged by high precision and agreement with previous reported findings. Studies are under way to evaluate the indexes in critically ill patients.
A systematic review of therapeutic hypothermia for adult patients following traumatic brain injury
Authors: Crossley Samantha , Reid Jenny , McLatchie Rachel , Hayton Judith , Clark Clair , MacDougall Margaret , Andrews Peter JD
Published: April 2014

Introduction

Research into therapeutic hypothermia following traumatic brain injury has been characterised by small trials of poor methodological quality, producing variable results. The Cochrane review, published in 2009, now requires updating. The aim of this systematic review is to assess the effectiveness of the application of therapeutic hypothermia to reduce death and disability when administered to adult patients who have been admitted to hospital following traumatic brain injury.

Methods

Two authors extracted data from each trial. Unless stated in the trial report, relative risks and 95% confidence intervals (CIs) were calculated for each trial. We considered P < 0 · 05 to be statistically significant. We combined data from all trials to estimate the pooled risk ratio (RR) with 95% confidence intervals for death, unfavourable outcome, and pneumonia. All statistical analyses were performed using RevMan 5.1 (Cochrane IMS, Oxford, UK) and Stata (Intercooled Version 12.0, StataCorp LP). Pooled RRs were calculated using the Mantel-Haenszel estimator. The random effects model of DerSimonian and Laird was used to estimate variances for the Mantel-Haenszel and inverse variance estimators.

Results

Twenty studies are included in the review, while 18 provided mortality data. When the results of 18 trials that evaluated mortality as one of the outcomes were statistically aggregated, therapeutic hypothermia was associated with a significant reduction in mortality and a significant reduction in poor outcome. There was a lack of statistical evidence for an association between use of therapeutic hypothermia and increased onset of new pneumonia.

Conclusions

In contrast to previous reviews, this systematic review found some evidence to suggest that therapeutic hypothermia may be of benefit in the treatment of traumatic brain injury. The majority of trials were of low quality, with unclear allocation concealment. Low quality trials may overestimate the effectiveness of hypothermia treatment versus standard care. There remains a need for more, high quality, randomised control trials of therapeutic hypothermia after traumatic brain injury.

PROSPERO Systematic Review Registration Number 2012:CRD42012002449.
Nonmyocytic Androgen Receptor Regulates the Sexually Dimorphic Development of the Embryonic Bulbocavernosus Muscle
Authors: Ipulan Lerrie Ann , Suzuki Kentaro , Sakamoto Yuki , Murashima Aki , Imai Yuuki , Omori Akiko , Nakagata Naomi , Nishinakamura Ryuichi , Valasek Petr , Yamada Gen
Published: April 2014

The bulbocavernosus (BC) is a sexually dimorphic muscle observed only in males. Androgen receptor knockout mouse studies show the loss of BC formation. This suggests that androgen signaling plays a vital role in its development. Androgen has been known to induce muscle hypertrophy through satellite cell activation and myonuclei accretion during muscle regeneration and growth. Whether the same mechanism is present during embryonic development is not yet elucidated. To identify the mechanism of sexual dimorphism during BC development, the timing of morphological differences was first established. It was revealed that the BC was morphologically different between male and female mice at embryonic day (E) 16.5. Differences in the myogenic process were detected at E15.5. The male BC possesses a higher number of proliferating undifferentiated myoblasts. To identify the role of androgen signaling in this process, muscle-specific androgen receptor (AR) mutation was introduced, which resulted in no observable phenotypes. Hence, the expression of AR in the BC was examined and found that the AR did not colocalize with any muscle markers such as Myogenic differentiation 1, Myogenin, and paired box transcription factor 7. It was revealed that the mesenchyme surrounding the BC expressed AR and the BC started to express AR at E15.5. AR mutation on the nonmyocytic cells using spalt-like transcription factor 1 (Sall1) Cre driver mouse was performed, which resulted in defective BC formation. It was revealed that the number of proliferating undifferentiated myoblasts was reduced in the Sall1 Cre:ARL−/Y mutant embryos, and the adult mutants were devoid of BC. The transition of myoblasts from proliferation to differentiation is mediated by cyclin-dependent kinase inhibitors. An increased expression of p21 was observed in the BC myoblast of the Sall1 Cre:ARL−/Y mutant and wild-type female. Altogether this study suggests that the nonmyocytic AR may paracrinely regulate the proliferation of myoblast possibly through inhibiting p21 expression in myoblasts of the BC.
S. pombe TOR complex 1 activates the ubiquitin-proteasomal degradation of the meiotic regulator Mei2 in cooperation with Pat1 kinase
Authors: Otsubo Yoko , Yamashita Akira , Ohno Hayao , Yamamoto Masayuki
Published: April 2014

TOR kinase regulates cell metabolism and growth, composing two multi-protein complexes TORC1 and TORC2. Known TORC substrates are either kinases or general factors involved in growth control. Here we show that fission yeast TORC1, which promotes vegetative growth and suppresses sexual development, can phosphorylate Mei2 in vitro, which is a specific factor switching the cell fate. Alanine substitutions at the nine phosphorylation sites stabilize Mei2 and promote mating and meiosis in vivo. Mei2 was found to be poly-ubiquitylated in vivo in a TORC1-dependent manner. Taken together, we propose that TORC1 contributes to the suppression of sexual development by phosphorylating Mei2, in addition to controlling the cellular metabolic status.
Spontaneous unraveling of hagfish slime thread skeins is mediated by a seawater-soluble protein adhesive
Authors: Bernards Mark A. , Oke Isdin , Heyland Andreas , Fudge Douglas S.
Published: April 2014

Hagfishes are known for their ability to rapidly produce vast quantities of slime when provoked. The slime is formed via the interaction between seawater and two components released by the slime glands: mucin vesicles from gland mucous cells, which swell and rupture in seawater to form a network of mucus strands, and intermediate filament-rich threads, which are produced within gland thread cells as tightly coiled bundles called skeins. A previous study showed that the unraveling of skeins from Atlantic hagfish (Myxine glutinosa) requires both the presence of mucins and hydrodynamic mixing. In contrast, skeins from Pacific hagfish (Eptatretus stoutii) unravel in the absence of both mucins and mixing. We tested the hypothesis that spontaneous unraveling of E. stoutii skeins is triggered by the dissolution of a seawater-soluble protein adhesive and the release of stored strain energy within the coiled thread. Here we show that, as predicted by this hypothesis, unraveling can be initiated by a protease under conditions in which unraveling does not normally occur. We also demonstrate, using high resolution scanning electron microscopy, that the treatment of skeins with solutions that cause unraveling also leads to the disappearance of surface and inter-thread features that remain when skeins are washed with stabilizing solutions. Our study provides a mechanism for the deployment of thread skeins in Pacific hagfish slime, and raises the possibility of producing novel biomimetic protein adhesives that are salt, temperature and kosmotrope sensitive.
Characterisation of putative oxygen chemoreceptors in bowfin (Amia calva)
Authors: Porteus Cosima S. , Wright Patricia A. , Milsom William K.
Published: April 2014

Serotonin containing neuroepithelial cells (NECs) are putative oxygen sensing cells found in different locations within the gills of fish. In this study we wished to determine the effect of sustained internal (blood) hypoxaemia versus external (aquatic) hypoxia on the size and density of NECs in the first gill arch of bowfin (Amia calva), a facultative air breather. We identified five different populations of serotonergic NECs in this species (Types I–V) based on location, presence of synaptic vesicles (SV) that stain for the antibody SV2, innervation and labelling with the neural crest marker HNK-1. Cell Types I–III were innervated, and these cells, which participate in central O2 chemoreflexes, were studied further. Although there was no change in the density of any cell type in bowfin after exposure to sustained hypoxia (6.0 kPa for 7 days) without access to air, all three of these cell types increased in size. In contrast, only Type II and III cells increased in size in bowfin exposed to sustained hypoxia with access to air. These data support the suggestion that NECs are putative oxygen-sensing cells, that they occur in several locations, and that Type I cells monitor only hypoxaemia, whereas both other cell types monitor hypoxia and hypoxaemia.
Social attraction mediated by fruit flies' microbiome
Authors: Venu Isvarya , Durisko Zachary , Xu Jianping , Dukas Reuven
Published: April 2014

Larval and adult fruit flies are attracted to volatiles emanating from food substrates that have been occupied by larvae. We tested whether such volatiles are emitted by the larval gut bacteria by conducting tests under bacteria-free (axenic) conditions. We also tested attraction to two bacteria species, Lactobacillus brevis, which we cultured from larvae in our lab, and L. plantarum, a common constituent of fruit flies' microbiome in other laboratory populations and in wild fruit flies. Neither larvae nor adults showed attraction to axenic food that had been occupied by axenic larvae, but both showed the previously reported attraction to standard food that had been occupied by larvae with an intact microbiome. Larvae also showed significant attraction to volatiles from axenic food and larvae to which we added only either L. brevis or L. plantarum, and volatiles from L. brevis reared on its optimal growth medium. Controlled learning experiments indicated that larvae experienced with both standard and axenic used food do not perceive either as superior, while focal larvae experienced with simulated used food, which contains burrows, perceive it as superior to unused food. Our results suggest that flies rely on microbiome-derived volatiles for long-distance attraction to suitable food patches. Under natural settings, fruits often contain harmful fungi and bacteria, and both L. brevis and L. plantarum produce compounds that suppress the growth of some antagonistic fungi and bacteria. The larval microbiome volatiles may therefore lead prospective fruit flies towards substrates with a hospitable microbial environment.
Optic flow and sea - land orientation in the sandhopper Talitrus saltator (Montagu)
Authors: Ugolini Alberto
Published: April 2014

The problem sandhoppers face when they find themselves on the dry sand is to reach as quickly as possible the belt of moist sand near the water. Alongside many other orienting factors, here we ask whether sandhoppers use the optic flow they experience to maintain their bearing relative to the sea - land axis. Adult individuals of Talitrus saltator (Montagu) were released in a transparent Plexiglas bowl, horizontally placed between four walls carrying a pattern of vertical black and white stripes. The orientation of one pair of opposite walls was South - North, orthogonal to the sea - land axis of the home beach, whilst the second pair of walls was oriented East - West. The black and white stripes pattern of opposite walls could be moved in pairs and in the same direction (speed = 4.8 cm sec-1). The results demonstrate that the optic flow sandhoppers experience when moving on the sea - land axis of their home beach influences their direction of travel and could help sandhoppers in maintaining a straight path to reach favourable ground by the shortest route.
Novel underwater soundscape: acoustic repertoire of plainfin midshipman fish
Authors: McIver Eileen L. , Marchaterre Margaret A. , Rice Aaron N. , Bass Andrew H.
Published: April 2014

Toadfishes are among the best-known groups of sound producing (vocal) fishes and include species commonly known as toadfish and midshipman. Although midshipman have been the subject of extensive investigation of the neural mechanisms of vocalization, this is the first comprehensive, quantitative analysis of the spectro-temporal characters of their acoustic signals and one of the few for fishes in general. Field recordings of territorial, nest-guarding male midshipman during the breeding season identified a diverse vocal repertoire comprised of three basic sound types that varied widely in duration, harmonic structure, and degree of amplitude modulation (AM) - "hum", "grunt", and "growl". Hum duration varied nearly 1000 fold, lasting for minutes at a time, with stable harmonic stacks and little envelope modulation throughout the sound. By contrast, grunts were brief, ~30-140 ms, broadband signals produced both in isolation and repetitively as a train of up to 200 at intervals of ~0.5-1.0 s. Growls were also produced alone or repetitively, but at variable intervals on the order of seconds with durations between that of grunts and hums, ranging 60 fold from ~200 ms - 12 s. Growls exhibited prominent harmonics with sudden shifts in pulse repetition rate and highly variable AM patterns, unlike the nearly constant AM of grunt trains and flat envelope of hums. Behavioral and neurophysiological studies support the hypothesis that each sound type's unique acoustic signature contributes to signal recognition mechanisms. Nocturnal production of these sounds against a background chorus dominated constantly for hours by a single sound type, the multi-harmonic hum, reveals a novel underwater soundscape for fish.
Substituent Effects on the Geometries and Energies of the Antimony–Silicon Multiple Bond
Authors: Wen Xiang-Ting , Li Yu-Chi , Su Ming-Der
Published: April 2014

Substituent effects on the potential energy surface of XSiSb (X = H, Li, Na, BeH, MgH, BH2, AlH2, CH3, SiH3, NH2, PH2, OH, SH, F, and Cl) were investigated by using B3LYP/Def2-TZVP, B3PW91/Def2-TZVPP, and CCSD(T) methods. The isomers include structures with formal double (Si=SbX) and triple (XSi≡Sb) bonds to silicon–antimony, so a direct comparison of these types of species is possible. Our model calculations indicate that electropositively substituted Si=SbX species are thermodynamically and kinetically more stable than their isomeric XSi≡Sb molecules. Moreover, the theoretical findings suggest that F, OH, NH2, and CH3 substitutions prefer to shift the double bond (Si=SbX) by forming a triple bond (XSi≡Sb).
Energy Transition in Austria: Designing Mitigation Wedges
Authors: Köppl Angela , Kettner Claudia , Kletzan-Slamanig Daniela , Schleicher Stefan , Damm Andrea , Steininger Karl , Wolkinger Brigitte , Schnitzer Hans , Titz Michaela , Artner Heidemarie , Karner Andreas
Published: April 2014

EU climate and energy policy defines ambitious objectives for the Member States, requiring a fundamental change in energy systems. In an interdisciplinary approach, starting with welfare-generating energy services instead of energy flows, we analyse restructuring options for the Austrian energy system. We extend the concept of stabilization wedges by Pacala and Socolow and integrate technological and behavioural options into a structural energy model, complemented by an economic evaluation in an input-output analysis. We apply the energy service based approach to a transformation of the Austrian energy system that meets the EU 2020 emission targets. We estimate that this would require on average additional investment of about 6 billion € p.a. over a twelve year period. This investment allows to tap savings in operating costs (predominantly energy costs) of up to 4.3 billion € at the end of the period, when using a conservative assumption of non-rising energy prices.
Comparing the Use of Diesel and Wind Power in Pumping Water in Saudi Arabia
Authors: Rehman Shafiqur , Sahin Ahmet Z.
Published: April 2014

This study compares a diesel only power system with wind only power system for pumping water in some cities of Saudi Arabia. Cost of Energy (COE) is found to be very sensitive with respect to annual mean wind speed. For 10% annual capacity shortage, for example, the COE decreases by 11.5, 21.8, 22.3 and 13.5% at Dhahran, Riyadh, Jeddah, and Guriat, respectively for an increase in annual mean wind speed of only 0.4m/s. On the other hand, COE for zero capacity shortage is found to be 0.224, 0.455, 0.294, 0.334, and 1.379$/kWh at Dhahran, Riyadh, Jeddah, Guriat, and Nejran, respectively. The cost of pumping water from a well of 50 m total dynamic head (TDH) is studied for both the wind energy and diesel only systems. Cost of water when using wind energy system is found to be 5.35, 10.4, 6.94, 7.71, and 30.56US¢/m3 for Dhahran, Riyadh, Jeddah, Guriat and Nejran, respectively. Cost of water when using diesel only system is found to vary from 7 to 16.5US¢/m3 depending on the fuel price. Furthermore, the wind based system becomes more cost effective when the diesel fuel cost is more than 0.4$/L for all sites except for Nejran. Last but not the least, the utilization of wind power for water pumping in Saudi Arabia will result into avoidance of addition of around 24,000 tons of CO2 equivalent greenhouse gases from entering into the local atmosphere annually.
Design of water shock tube for testing shell materials
Authors: Ji H. , Mustafa M. , Khawaja H. , Ewan B. , Moatamedi M.
Published: April 2014

This paper presents design considerations for a shock tube experimental rig used to investigate the dynamic failure mechanisms of shell geometries subjected to water shock impact loading. In such setup, it is desirable that the drive pressure used within the tube can provide a wide range of impulsive loads on the test structures and some flexibility can be achieved on the applied pulse durations. With this aim a review of various existing shock tube experimental setup is presented and choices are made based on scientific merits. Finally design parameters are drawn for right set of conditions required for the experiments.
The mathematical model of crown height in hedgerow orchard on southern hill slope
Authors: Liu Yongchao , Ma Baoguo
Published: April 2014

In the hedgerow orchard of hilly land, the crown height changes with ground slope so as to meet the condition of the sun light. Using astronomical trigonometric formulas, this paper calculates solar position of the 40° north latitude in vernal equinox and autumnal equinox. At the same time, it calculates the shadow length of tree body, determines the shadow length coefficient y and drafts the chart of shadow top contour based on the solar azimuth angle A and the coefficient of shadow length γ. According to the design of the north-south direction, we take two lines of the hedge with the changing figure of the top contour of shadow and crown cross-section to get mathematical models which determine the crown height of different sections in different ground slope.
Generalized Inverse Multiobjective Optimization with Application to Cancer Therapy
Authors: Chan Timothy C. Y. , Craig Tim , Lee Taewoo , Sharpe Michael B.
Published: April 2014

We generalize the standard method of solving inverse optimization problems to allow for the solution of inverse problems that would otherwise be ill posed or infeasible. In multiobjective linear optimization, given a solution that is not a weakly efficient solution to the forward problem, our method generates objective function weights that make the given solution a near-weakly efficient solution. Our generalized inverse optimization model specializes to the standard model when the given solution is weakly efficient and retains the complexity of the underlying forward problem. We provide a novel interpretation of our inverse formulation as the dual of the well-known Benson's method and by doing so develop a new connection between inverse optimization and Pareto surface approximation techniques. We apply our method to prostate cancer data obtained from Princess Margaret Cancer Centre in Toronto, Canada. We demonstrate that clinically acceptable treatments can be generated using a small number of objective functions and inversely optimized weights—current treatments are designed using a complex formulation with a large parameter space in a trial-and-error reoptimization process. We also show that our method can identify objective functions that are most influential in treatment plan optimization.
Systemic effects of polymethylmethycrylate in total knee replacement
Authors: Cheng K. , Giebaly D. , Campbell A. , Rumley A. , Lowe G.
Published: April 2014

Objective

Mortality rates reported by the National Joint Registry for England and Wales (NJR) were higher following cemented total knee replacement (TKR) compared with uncemented procedures. The aim of this study is to examine and compare the effects of cemented and uncemented TKR on the activation of selected markers of inflammation, endothelium, and coagulation, and on the activation of selected cytokines involved in the various aspects of the systemic response following surgery.

Methods

This was a single centre, prospective, case-control study. Following enrolment, blood samples were taken pre-operatively, and further samples were collected at day one and day seven post-operatively. One patient in the cemented group developed a deep-vein thrombosis confirmed on ultrasonography and was excluded, leaving 19 patients in this cohort (mean age 67.4, (sd 10.62)), and one patient in the uncemented group developed a post-operative wound infection and was excluded, leaving 19 patients (mean age 66.5, (sd 7.82)).

Results

Both groups had a similar response with regards to the levels of C-reactive protein (CRP), interleukin 6 (IL-6) and tumour necrosis factor-alpha (TNFα). CD40 levels rose significantly on the cemented group over day one to day seven compared with that of the uncemented group, which occurred over the first 24 hours. The CD14/42a levels demonstrated a statistically significant increase in the cemented group (p < 0.001 first 24 hours and p = 0.02 between days one and seven).

Conclusions

The uncemented and cemented groups demonstrated significant changes in the various parameters measured at various time points but apart from CD14/42a levels, there was no significant difference in the serum markers of inflammation, coagulation and endothelial dysfunction following cemented TKR. Cite this article: Bone Joint Res 2014;3:108–16.
Combining Percutaneous Pedicular and Extrapedicular Access for Tumor Ablation in a Thoracic Vertebral Body
Authors: Cianfoni Alessandro , Massari Francesco , Ewing Stacey , Persenaire Maarten , Rumboldt Zoran , Bonaldi Giuseppe
Published: April 2014

We present a percutaneous modified technique to access large thoracic vertebral body lytic lesions, to increase the volume of tumor accessible to ablation, prior to cement augmentation.

Tumor ablation and cavity creation-assisted percutaneous vertebroplasty was considered a palliative measure for structural stabilization in plasmocytoma involvement of the entire T8 vertebral body. Given the extent of osteolysis bilateral combined transpedicular and extrapedicular access to the vertebral body was undertaken to maximize the volume of cavity creation within the tumor.

The combined transpedicular and extrapedicular access was feasible, uncomplicated, and successful in reaching all the quadrants of the anterior two thirds of the vertebral body. Slow, fluoroscopically monitored injection of high-viscosity cement resulted in a successful, desired cement distribution into the anterior two thirds of the vertebral body, spanning superior to inferior endplates, providing structural stability, in the absence of venous or epidural leakage.

The technical modification described in this case yielded positive results while overcoming some of the limitations of the existing coblation device. This approach may offer an option for cement augmentation of extensive vertebral body lytic lesions, at increased risk for tumor displacement and extra-vertebral cement leakage.
Intra-Operative Vertebroplasty Combined with Posterior Cord Decompression
Authors: Allegretti Luca , Mavilio Nicola , Fiaschi Pietro , Bragazzi Roberto , Pacetti Mattia , Castelletti Lara , Saitta Laura , Castellan Lucio
Published: April 2014

Percutaneous vertebroplasty (VP) is a minimally invasive technique for the treatment of vertebral pathology providing early vertebral stabilization and pain relief. In cases of vertebral pathology complicated by spinal cord compression with associated neurological deficits, VP alone cannot be performed free of risks. We describe a combined approach in which decompressive laminectomy and intra-operative vertebroplasty (IVP) are performed during a single session. Among the 252 VP performed in our centre in the past three years, 12 patients (12 vertebral levels) with different pathologies (six symptomatic haemangiomas, two metastatic fractures, four osteoporotic fractures) were treated with an open procedure combined with surgery. All cases were treated with decompressive laminectomy and IVP (mono/bipeduncular or median-posterior trans-somatic access). Five patients with symptomatic haemangiomas were treated with endovascular embolization prior to the combined approach. A visual analogue scale (VAS) was applied to assess pain intensity before and after surgery. The neurological deficits were evaluated with an ASIA impairment scale. In all cases benefit from pain and neurological deficits was observed. The mean VAS score decreased from 7.8 to 2.5 after surgery. The ASIA score improved in all cases (five cases from D to E and five cases from C to D). No clinical complications were observed. In one case a CT scan performed after the procedure showed a foraminal accumulation of PMMA, but the patient referred no symptoms. IVP can be successfully applied in different pathologies affecting the vertebrae. In our limited series this approach proved safe and efficient to provide decompression of spinal cord and dural sac and vertebral body stabilization in a single session.
Acute Vertebral Artery Origin Occlusion Leading to Basilar Artery Thrombosis Successfully Treated by Angioplasty with Stenting and Thrombectomy
Authors: Abe Arata , Okubo Seiji , Onozawa Shiro , Nakajima Masataka , Suzuki Kentaro , Harada-Abe Mina , Ueda Masayuki , Katsura Ken-Ichiro , Katayama Yasuo
Published: April 2014

Few reports have described the successful treatment of stroke caused by acute vertebral artery (VA) origin occlusion by endovascular surgery. We describe the case of a 68-year-old man who experienced stroke due to left acute VA origin occlusion. Cerebral angiography showed that the left VA was occluded at its origin, the right VA had hypoplastic and origin stenosis, and the basilar artery was occluded by a thrombus. The VA origin occlusion was initially passed through with a 0.035-inch guide wire. An angioplasty was performed, and a coronary stent was appropriately placed. The VA origin was successfully recanalized. A balloon-assisted guiding catheter was navigated through the stent and a thrombectomy was performed using the Penumbra system. The patient's symptoms gradually improved postoperatively. Balloon-assisted catheter guidance through a vertebral artery stent permitted a successful thrombectomy using the Penumbra system and may be useful for treating stroke due to VA origin occlusion.
Fatal Avulsion of Choroidal or Perforating Arteries by Guidewires
Authors: Darsaut Tim E. , Costalat Vincent , Salazkin Igor , Jamali Sara , Berthelet France , Gevry Guylaine , Roy Daniel , Raymond Jean
Published: April 2014

Innovations in endovascular tools have permitted an increasingly broad range of neurovascular lesions to be treated via minimally invasive methods. However, some device modifications may carry additional risks, not immediately apparent to operators.

A patient with a symptomatic, partially thrombosed basilar apex aneurysm was allocated balloon-assisted coiling. Attempts were made to place a microwire across the basilar apex through the posterior communicating artery. Overlapping courses of the posterior cerebral and posterior choroidal arteries on the roadmap images were not recognized and a flanged-tip microwire was inadvertently advanced deep into the choroidal artery. Following the wire with a microcatheter led to binding of arterial tissue within the microcatheter. Removing the wire led to an avulsion of the choroidal artery and a severe hemorrhagic complication which proved fatal. Tissue was identified on the tip of the guidewire. Pathology showed layers of vascular tissue within the laser-cut flanges of the distal wire tip.

A similar complication, also fatal, occurred during balloon angioplasty of a distal vertebral artery, when an exchange wire was accidently introduced into a perforator from a posterior cerebral artery.

Ex vivo catheterization of distal mesenteric arterial branches showed that the wall of small arteries can be entrapped by laser-cut, flanged, but not by smooth guidewire tips.

Microwires with a flanged instead of smooth distal tip, when placed into small caliber vessels, may cause hemorrhagic complications from avulsions.
Outcome Prediction in Acute Stroke Patients Considered for Endovascular Treatment: A Novel Tool
Authors: Grech Reuben , Galvin Patrick Leo , Power Sarah , O'Hare Alan , Looby Seamus , Brennan Paul , Thornton John
Published: April 2014

Functional outcome following emergent intra-arterial thrombectomy is variable and likely reflects the heterogeneous characteristics of acute stroke patients.

The aims of our study were (1) to study which pre-treatment variables correlate with functional outcome and (2) to devise a tool which would reliably predict outcome.

Prospective data of patients treated with intra-arterial mechanical thrombectomy in our institution between 2010 and 2012 were collected. A preliminary univariate analysis of baseline variables was performed and data outliers were identified by constructing scatter and box plots.

Systematic bivariate analysis was then carried out using a linear regression model and the individual contributing weights of the variables to outcome calculated. The B and constant values from the regression were used to construct a predictive formula.

Fifty-seven patients, 35 males (61.4%) and 22 females (38.6%) with a mean age of 62.3 years (range 26–87) were included in the cohort. Statistical correlations of baseline variables and functional outcome showed that age, National Institutes of Health Stroke Scale at presentation and CT leptomeningeal collaterals were strongly correlated (p<0.01), and were later included in the linear regression model. A tool was devised from the regression formula combining weighted inputs of the three variables. Regression statistics and residual analysis were then performed to assess the accuracy and reliability of the proposed tool.

The proposed tool is easy to use and reliably predicts functional outcome prior to endovascular therapy. It may help clinical decision-making in the acute setting and offers ‘tailor-made’ outcome expectations.
Intra-Arterial Therapy as a Rescue Strategy after Clinically Failed Intravenous Thrombolysis May Increase the Likelihood of a Good Outcome in Patients with Severe Ischaemic Stroke
Authors: Menetti Federico , Verganti Luca , Zini Andrea , Vallone Stefano , Carpeggiani Paolo , Andersson Tommy
Published: April 2014

The purpose of this study was to evaluate the efficacy and safety of intra-arterial therapy as a rescue strategy after clinically failed intravenous thrombolysis (IVT) in acute ischaemic stroke patients.

We conducted a retrospective analysis of consecutive acute ischaemic stroke patients treated with rescue therapy. The results from this study group were compared with those obtained from a control group consisting of 260 consecutive patients treated with IVT alone.

The study group consisted of 52 patients with a mean age of 63 years and a median NIHSS score at admission of 17. Recanalization was achieved in 92% with a symptomatic haemorrhage rate of 9.6%. Rescue patients admitted with a severe stroke (NIHSS score >12) had a significantly better outcome at 90 days compared to patients with the same score but treated with IVT alone. No difference was seen for patients with a lower score at admission.

This study indicates that rescue therapy may increase the proportion of patients with independent outcome if presenting with a severe stroke (NIHSS score >12) without increasing the rate of symptomatic haemorrhage.
CT-Guided Transfacet Pedicle Screw Fixation in Facet Joint Syndrome: A Novel Approach
Authors: Manfré Luigi
Published: April 2014

Axial microinstability secondary to disc degeneration and consequent chronic facet joint syndrome (CFJS) is a well-known pathological entity, usually responsible for low back pain (LBP). Although posterior lumbar fixation (PIF) has been widely used for lumbar spine instability and LBP, complications related to wrong screw introduction, perineural scars and extensive muscle dissection leading to muscle dysfunction have been described. Radiofrequency ablation (RFA) of facet joints zygapophyseal nerves conventionally used for pain treatment fails in approximately 21% of patients. We investigated a “covert-surgery” minimal invasive technique to treat local spinal instability and LBP, using a novel fully CT-guided approach in patients with axial instability complicated by CFJS resistant to radioablation, by introducing direct fully or partially threaded transfacet screws (transfacet fixation - TFF), to acquire solid arthrodesis, reducing instability and LBP. The CT-guided procedure was well tolerated by all patients in simple analogue sedation, and mean operative time was approximately 45 minutes. All eight patients treated underwent clinical and CT study follow-up at two months, revealing LBP disappearance in six patients, and a significant reduction of lumbar pain in two. In conclusion, CT-guided TFF is a fast and safe technique when facet posterior fixation is needed.
Mechanical Thrombectomy versus Intrasinus Thrombolysis for Cerebral Venous Sinus Thrombosis: A Non-Randomized Comparison
Authors: Siddiqui Fazeel M. , Banerjee Chirantan , Zuurbier Susanna M. , Hao Qing , Ahn Chul , Pride Glenn L. , Wasay Muhammad , Majoie Charles B.L.M. , Liebeskind David , Johnson Mark , Stam Jan
Published: April 2014

Small retrospective studies have shown the benefit of endovascular treatment with intrasinus thrombolysis (IST) or mechanical thrombectomy (MT) with/without IST (MT+/−IST) in cases of multifocal cerebral venous thrombosis (CVT).

Our study compares the mortality, functional outcome and periprocedural complications among patients treated with MT +/– IST versus IST alone.

We reviewed clinical and angiographic findings of 63 patients with CVT who received endovascular treatment at three tertiary care centers. Primary outcome variables were discharge mortality and neurological dysfunction, and intermediate (three months) and long-term (>six months) morbidity. The modified Rankin scale (mRS) was used to assess morbidity. mRS ≤1 was considered a good recovery. Neurological dysfunction was rated as neuroscore: 0, normal; 1, mild (ambulatory, communicative); 2, moderate (non-ambulatory, communicative); and 3, severe (non-ambulatory, non-communicative/comatose).

In patients who received IST alone, presenting neurological deficits were comparatively minor (p<0.001). When the two groups were adjusted for admission neuroscore, there was no statistical significance between discharge mortality [7(21%) versus 4(14%), p=0.228], neurological dysfunction (p=0.442), intermediate (p=0.336) and long-term morbidity (p=0.988). Patients who received MT +/- IST had a higher percentage of periprocedural complications without reaching statistical significance.

Compared to IST, MT was performed in severe cases with extensive sinus involvement. When adjusted for admission neurological dysfunction, both groups had similar mortality and discharge neurological dysfunction and similar intermediate and long-term morbidity.
MR-Guided Focused Ultrasound: A New Generation Treatment of Parkinson's Disease, Essential Tremor and Neuropathic Pain
Authors: Dobrakowski Pawel Piotr , Machowska-Majchrzak Agnieszka Kamila , Łabuz-Roszak Beata , Majchrzak Krzysztof Grzegorz , Kluczewska Ewa , Pierzchała Krystyna Barbara
Published: April 2014

The application of high intense focused ultrasound (HIFU) is currently the subject of many experimental and clinical trials. The combination of HIFU with MRI guidance known as MR-guided focused ultrasound (MRgFUS) appears to be particularly promising to ablate tissues located deep in the brain. The method can be the beginning of interventional neurology and an important alternative to neurosurgery. Studies conducted to date show the effectiveness of the method both in chronic diseases and in emergency cases. The safety and effectiveness of this method have been observed in parkinsonian and essential tremor as well as in neuropathic pain. The procedure does not require anaesthesia. Ionizing radiation is not used and there is no risk of cumulative dose. Such advantages may result in low complication rates and medical justification for further development of MRgFUS.
Brainstem Hemorrhage Caused by Direct Carotid-Cavernous Fistula
Authors: Chan Fook-How , Shen Chao-Yu , Liu Jung-Tung , Li Cho-Shun
Published: April 2014

A 34-year-old woman presented with a history of persisting headache for years, and a newly developed dizziness, left facial palsy and right hemiparesis two days prior to this admission. Initial computed tomographic angiography of the head demonstrated an area of increased density in the left middle and posterior fossae. Multiple aneurysmally dilated venous ectasias with contrast enhancement at the left pre-pontine cistern causing a massive mass effect to the brainstem were also noted, suggesting a huge vascular abnormality. Digital subtraction angiography revealed an abnormal vascular lesion surrounding the brainstem, which indicated a left direct carotid-cavernous fistula with posterior drainage. As her consciousness deteriorated the next day, a follow-up computed tomography scan was done which revealed a pontine hemorrhage. Subsequently, endovascular closure of the fistula with sacrifice of the left ICA was performed, which successfully eliminated the imaging abnormalities.
Use of Intermediate Guide Catheters as an Adjunct in Extracranial Embolization to Avoid Onyx Reflux into the Anastomotic Vasculature
Authors: Puri Ajit S. , Kühn Anna L. , Hou Samuel Y. , Wakhloo Ajay K.
Published: April 2014

Onyx is a non-adhesive polymer used for embolization of arteriovenous malformations and dural arteriovenous fistulas (DAVFs). The limiting factor for Onyx embolization is usually the amount of microcatheter reflux, which can be safely tolerated. The dual microcatheter technique, compliant balloon use proximally and the use of the dual lumen Scepter balloon have been described to prevent and limit proximal Onyx reflux. We describe the use the Navien 058 intermediate guide catheter to accept the Onyx reflux in its lumen and possibly also serve as a mechanical barrier to avoid reflux into the anastomotic channel connecting the occipital artery to the vertebral artery during DAVF embolization via the occipital artery. Complete embolization of the DAVF was achieved using the lumen of the Navien catheter to accept aggressive Onyx reflux. Complete cure of the DAVF was obtained with Onyx cast filling the entire venous pouch. Besides providing distal access support, intermediate guide catheters can also prevent embolic material reflux by accepting reflux into the lumen and providing a mechanical barrier.
Selective and Superselective Angiography of Pediatric Moyamoya Disease Angioarchitecture in the Posterior Circulation
Authors: Baltsavias Gerasimos , Khan Nadia , Filipce Venko , Valavanis Anton
Published: April 2014

The anastomotic network of the posterior circulation in children with moyamoya disease has not been analyzed. We aimed to investigate the angiographic anatomy of this unique vascular network in patients with childhood moyamoya disease.

Selective and superselective injections of the posterior circulation were performed in six children with newly diagnosed moyamoya disease. The arterial branches feeding the moyamoya anastomotic network, their connections and the recipient vessels were demonstrated.

Depending on the level of the steno-occlusive lesion, the feeding vessels were the thalamoperforators, the posterior choroidals, the splenic artery, parietoccipital artery, other cortical posterior cerebral artery (PCA) branches, the dural branch of the PCA, the premamillary artery and other posterior communicating artery perforators. Through connections, which are described, the recipient vessels were the striate and medullary arteries, other thalamic arteries with or without medullary extensions, the pericallosal artery, medial parietoccipital cortical branches of the PCA and the anterior choroidal artery.

High quality selective and superselective angiography helped in demonstrating the angiographic anatomy of the moyamoya posterior anastomotic network previously either vaguely or incompletely described, as well as connections within the posterior circulation but also its relevance as a collateral to the anterior circulation.
Use of the Pipeline Embolization Device to Treat Recently Ruptured Dissecting Cerebral Aneurysms
Authors: Chan Robert S.K. , Mak Calvin H.K. , Wong Alain K.S. , Chan Kwong Yau , Leung Kar Ming
Published: April 2014

The Pipeline embolization device (PED) is one of the flow-diverting stents approved for the treatment of unruptured large or wide-necked cerebral aneurysms in 2011. Its use has now been extended to the treatment of recently ruptured dissecting cerebral aneurysm, carotid pseudoaneurysm from radiation injury, and blister aneurysms. We aimed to evaluate the effectiveness of utilizing the PED as a primary treatment for ruptured dissecting intracranial aneurysms.

A single center retrospective review was conducted for all patients primarily treated with PED for acute subarachnoid hemorrhage (SAH) from ruptured dissecting cerebral aneurysms between December 2010 and February 2013. Patients were followed up with CT angiogram (CTA) or digital subtraction angiogram (DSA).

Eight patients with a total of eight dissecting aneurysms were identified. The mean duration from SAH to treatment was 2.5 days. Six of the aneurysms arose from vertebral arteries and two from the basilar artery. Immediate check-DSA confirmed satisfactory contrast stasis in all eight cases, and complete aneurysmal obliteration was achieved at six months. There were two (25%) procedure-related complications, but no major procedure-related complications, such as thromboembolic events or rebleeding from aneurysm were encountered.

The PED is a feasible treatment option for ruptured dissecting cerebral aneurysms in acute phase. According to our experience, using PED as flow-diverters in acute SAH does not significantly increase the complication risks or mortality rate if the antiplatelet regime is carefully monitored. Future studies shall evaluate the optimal antiplatelet regimen for using the PED in the acute phase.
Chromogranin A predicts outcome in prostate cancer patients treated with abiraterone
Authors: Burgio Salvatore Luca , Conteduca Vincenza , Menna Cecilia , Carretta Elisa , Rossi Lorena , Bianchi Emanuela , Kopf Barbara , Fabbri Francesca , Amadori Dino , De Giorgi Ugo
Published: April 2014

In this retrospective study, we evaluated the chromogranin A (CgA) baseline value as a predictor of clinical outcome in patients with metastatic castration-resistant prostate cancer (CRPC) treated with abiraterone 1000 mg per day, whose disease progressed after docetaxel chemotherapy. In the 48 evaluable patients, serum CgA level was normal when <120 ng/ml (group A, n=16), within three times the upper normal value (UNV) when between 120 and 360 (group B, n=16), more than three times the UNV when ≥360 ng/ml (group C, n=16). Decline in PSA level ≥50% or more (PSA RR) was observed in 26 of 48 (54%) patients. PSA response rate did not correlate with the CgA groups. CgA levels more than three times the UNV predicted an early radiological progressive disease in eight of 11 cases (73%). The median progression-free survival (PFS) among the CgA groups A, B, and C was 9.2, 9.2, and 4.8 months respectively, P=0.0459. The median overall survival (OS) among the CgA groups was 19.0, 18.8, and 10.8 months respectively, P=0.2092. In the multivariate analysis, PSA RR (nonresponsive vs responsive) and CgA levels (group 3 vs groups 1+2) were predictors of PFS (P=0.0002 and P=0.0047 respectively), whereas PSA RR only was significantly associated with OS (P=0.0024), while CgA levels remained of borderline significance (P=0.0919). A serum CGA level more than three times the UNV predicted PFS and showed a trend vs OS prediction, independently from PSA response, in CRPC patients treated with abiraterone.