Development of a vibration haptic simulator for shoulder arthroplasty

Abstract

Purpose

Glenoid reaming is a technically challenging step during shoulder arthroplasty that could possibly be learned during simulation training. Creation of a realistic simulation using vibration feedback in this context is innovative. Our study focused on the development and internal validation of a novel glenoid reaming simulator for potential use as a training tool.

Methods

Vibration and force profiles associated with glenoid reaming were quantified during a cadaveric experiment. Subsequently, a simulator was fabricated utilizing a haptic vibration transducer with high- and low-fidelity amplifiers; system calibration was performed matching vibration peak–peak values for both amplifiers. Eight experts performed simulated reaming trials. The experts were asked to identify isolated layer profiles produced by the simulator. Additionally, experts' efficiency to successfully perform a simulated glenoid ream based solely on vibration feedback was recorded.

Results

Cadaveric experimental cartilage reaming produced lower vibrations compared to subchondral and cancellous bones ( \(p\le 0.03\) ). Gain calibration of a lower-fidelity (3.5  \({g}_{\mathrm{pk-pk}}, 0.36\,{g}_{\mathrm{rms}})\) and higher-fidelity (3.4  \({g}_{\mathrm{pk-pk}}, 0.33\,{g}_{\mathrm{rms}})\) amplifier resulted in values similar to the cadaveric experimental benchmark (3.5  \({g}_{\mathrm{pk-pk}}, 0.30\,{g}_{\mathrm{rms}})\) . When identifying random tissue layer samples, experts were correct \(52\pm 9\%\) of the time and success rate varied with tissue type ( \(p=0.003\) ). During simulated reaming, the experts stopped at the targeted subchondral bone with a success rate of \(78\pm 24\%\) . The fidelity of the simulation did not have an effect on accuracy, applied force, or reaming time ( \(p>0.05\) ). However, the applied force tended to increase with trial number ( \(p=0.047\) ).

Conclusions

Development of the glenoid reaming simulator, coupled with expert evaluation furthered our understanding of the role of haptic vibration feedback during glenoid reaming. This study was the first to (1) propose, develop and examine simulated glenoid reaming, and (2) explore the use of haptic vibration feedback in the realm of shoulder arthroplasty.

IMHOTEP: virtual reality framework for surgical applications

Abstract

Purpose

The data which is available to surgeons before, during and after surgery is steadily increasing in quantity as well as diversity. When planning a patient's treatment, this large amount of information can be difficult to interpret. To aid in processing the information, new methods need to be found to present multimodal patient data, ideally combining textual, imagery, temporal and 3D data in a holistic and context-aware system.

Methods

We present an open-source framework which allows handling of patient data in a virtual reality (VR) environment. By using VR technology, the workspace available to the surgeon is maximized and 3D patient data is rendered in stereo, which increases depth perception. The framework organizes the data into workspaces and contains tools which allow users to control, manipulate and enhance the data. Due to the framework's modular design, it can easily be adapted and extended for various clinical applications.

Results

The framework was evaluated by clinical personnel (77 participants). The majority of the group stated that a complex surgical situation is easier to comprehend by using the framework, and that it is very well suited for education. Furthermore, the application to various clinical scenarios—including the simulation of excitation propagation in the human atrium—demonstrated the framework's adaptability. As a feasibility study, the framework was used during the planning phase of the surgical removal of a large central carcinoma from a patient's liver.

Conclusion

The clinical evaluation showed a large potential and high acceptance for the VR environment in a medical context. The various applications confirmed that the framework is easily extended and can be used in real-time simulation as well as for the manipulation of complex anatomical structures.

A hybrid image fusion system for endovascular interventions of peripheral artery disease

Abstract

Purpose

Interventional endovascular treatment has become the first line of management in the treatment of peripheral artery disease (PAD). However, contrast and radiation exposure continue to limit the feasibility of these procedures. This paper presents a novel hybrid image fusion system for endovascular intervention of PAD. We present two different roadmapping methods from intra- and pre-interventional imaging that can be used either simultaneously or independently, constituting the navigation system.

Methods

The navigation system is decomposed into several steps that can be entirely integrated within the procedure workflow without modifying it to benefit from the roadmapping. First, a 2D panorama of the entire peripheral artery system is automatically created based on a sequence of stepping fluoroscopic images acquired during the intra-interventional diagnosis phase. During the interventional phase, the live image can be synchronized on the panorama to form the basis of the image fusion system. Two types of augmented information are then integrated. First, an angiography panorama is proposed to avoid contrast media re-injection. Information exploiting the pre-interventional computed tomography angiography (CTA) is also brought to the surgeon by means of semiautomatic 3D/2D registration on the 2D panorama. Each step of the workflow was independently validated.

Results

Experiments for both the 2D panorama creation and the synchronization processes showed very accurate results (errors of 1.24 and \(2.6 \pm 1.4\)  mm, respectively), similarly to the registration on the 3D CTA (errors of \(1.5 \pm 0.7\)  mm), with minimal user interaction and very low computation time. First results of an on-going clinical study highlighted its major clinical added value on intraoperative parameters.

Conclusion

No image fusion system has been proposed yet for endovascular procedures of PAD in lower extremities. More globally, such a navigation system, combining image fusion from different 2D and 3D image sources, is novel in the field of endovascular procedures.

Automated surgical skill assessment in RMIS training

Abstract

Purpose

Manual feedback in basic robot-assisted minimally invasive surgery (RMIS) training can consume a significant amount of time from expert surgeons' schedule and is prone to subjectivity. In this paper, we explore the usage of different holistic features for automated skill assessment using only robot kinematic data and propose a weighted feature fusion technique for improving score prediction performance. Moreover, we also propose a method for generating 'task highlights' which can give surgeons a more directed feedback regarding which segments had the most effect on the final skill score.

Methods

We perform our experiments on the publicly available JHU-ISI Gesture and Skill Assessment Working Set (JIGSAWS) and evaluate four different types of holistic features from robot kinematic data—sequential motion texture (SMT), discrete Fourier transform (DFT), discrete cosine transform (DCT) and approximate entropy (ApEn). The features are then used for skill classification and exact skill score prediction. Along with using these features individually, we also evaluate the performance using our proposed weighted combination technique. The task highlights are produced using DCT features.

Results

Our results demonstrate that these holistic features outperform all previous Hidden Markov Model (HMM)-based state-of-the-art methods for skill classification on the JIGSAWS dataset. Also, our proposed feature fusion strategy significantly improves performance for skill score predictions achieving up to 0.61 average spearman correlation coefficient. Moreover, we provide an analysis on how the proposed task highlights can relate to different surgical gestures within a task.

Conclusions

Holistic features capturing global information from robot kinematic data can successfully be used for evaluating surgeon skill in basic surgical tasks on the da Vinci robot. Using the framework presented can potentially allow for real-time score feedback in RMIS training and help surgical trainees have more focused training.

High dynamic range ultrasound imaging

Abstract

Purpose

High dynamic range (HDR) imaging is a popular computational photography technique that has found its way into every modern smartphone and camera. In HDR imaging, images acquired at different exposures are combined to increase the luminance range of the final image, thereby extending the limited dynamic range of the camera. Ultrasound imaging suffers from limited dynamic range as well; at higher power levels, the hyperechogenic tissue is overexposed, whereas at lower power levels, hypoechogenic tissue details are not visible. In this work, we apply HDR techniques to ultrasound imaging, where we combine ultrasound images acquired at different power levels to improve the level of detail visible in the final image.

Methods

Ultrasound images of ex vivo and in vivo tissue are acquired at different acoustic power levels and then combined to generate HDR ultrasound (HDR-US) images. The performance of five tone mapping operators is quantitatively evaluated using a similarity metric to determine the most suitable mapping for HDR-US imaging.

Results

The ex vivo and in vivo results demonstrated that HDR-US imaging enables visualizing both hyper- and hypoechogenic tissue at once in a single image. The Durand tone mapping operator preserved the most amount of detail across the dynamic range.

Conclusions

Our results strongly suggest that HDR-US imaging can improve the utility of ultrasound in image-based diagnosis and procedure guidance.

Fully automatic detection of renal cysts in abdominal CT scans

Abstract

Purpose

Simple renal cysts are a common benign finding in abdominal CT scans. However, since they may evolve in time, simple cysts need to be reported. With an ever-growing number of slices per CT scan, cysts are easily overlooked by the overloaded radiologist. In this paper, we address the detection of simple renal cysts as an incidental finding in a real clinical setting.

Methods

We propose a fully automatic framework for renal cyst detection, supported by a robust segmentation of the kidneys performed by a fully convolutional neural network. A combined 3D distance map of the kidneys and surrounding fluids provides initial candidates for cysts. Eventually, a second convolutional neural network classifies the candidates as cysts or non-cyst objects.

Results

Performance was evaluated on 52 abdominal CT scans selected at random in a real radiological workflow and containing over 70 cysts annotated by an experienced radiologist. Setting the minimal cyst diameter to 10 mm, the algorithm detected 59/70 cysts (true-positive rate = 84.3%) while producing an average of 1.6 false-positive per case.

Conclusions

The obtained results suggest the proposed framework is a promising approach for the automatic detection of renal cysts as incidental findings of abdominal CT scans.

Retrieval and registration of long-range overlapping frames for scalable mosaicking of in vivo fetoscopy

Abstract

Purpose

The standard clinical treatment of Twin-to-Twin transfusion syndrome consists in the photo-coagulation of undesired anastomoses located on the placenta which are responsible to a blood transfer between the two twins. While being the standard of care procedure, fetoscopy suffers from a limited field-of-view of the placenta resulting in missed anastomoses. To facilitate the task of the clinician, building a global map of the placenta providing a larger overview of the vascular network is highly desired.

Methods

To overcome the challenging visual conditions inherent to in vivo sequences (low contrast, obstructions or presence of artifacts, among others), we propose the following contributions: (1) robust pairwise registration is achieved by aligning the orientation of the image gradients, and (2) difficulties regarding long-range consistency (e.g. due to the presence of outliers) is tackled via a bag-of-word strategy, which identifies overlapping frames of the sequence to be registered regardless of their respective location in time.

Results

In addition to visual difficulties, in vivo sequences are characterised by the intrinsic absence of gold standard. We present mosaics motivating qualitatively our methodological choices and demonstrating their promising aspect. We also demonstrate semi-quantitatively, via visual inspection of registration results, the efficacy of our registration approach in comparison with two standard baselines.

Conclusion

This paper proposes the first approach for the construction of mosaics of placenta in in vivo fetoscopy sequences. Robustness to visual challenges during registration and long-range temporal consistency are proposed, offering first positive results on in vivo data for which standard mosaicking techniques are not applicable.

Trackerless panoramic optoacoustic imaging: a first feasibility evaluation

Abstract

Purpose

Optoacoustic imaging provides high spatial resolution and the possibility to image specific functional parameters in real-time, therefore positioning itself as a promising modality for various applications. However, despite these advantages, the applicability of real-time optoacoustic imaging is generally limited due to a relatively small field of view.

Methods

With this work, we aim at presenting a path towards panoramic optoacoustic tomographic imaging without requiring additional sensors or position trackers. We propose a two-step seamless stitching method for the compounding of multiple datasets acquired with a real-time 3D optoacoustic imaging system within a panoramic scan. The employed workflow is specifically tailored to the image properties and respective challenges.

Results

A comparison of the presented alignment on in-vivo data shows a mean error of \(628 \pm 512\,\upmu \hbox {m}\) compared to ground truth tracking data. The presented compounding scheme integrates the physical resolution of optoacoustic data and hence can provide improved contrast in comparison with other compounding approaches based on addition or averaging.

Conclusion

The proposed method can produce optoacoustic volumes with an enlarged field of view and improved quality compared to current methods in optoacoustic imaging. However, our study also shows challenges for panoramic scans. In this view, we discuss relevant properties, challenges, and opportunities and present an evaluation of the performance of the presented approach with different input data.

Automatic intraoperative estimation of blood flow direction during neurosurgical interventions

Abstract

Purpose

In neurosurgery, reliable information about blood vessel anatomy and flow direction is important to identify, characterize, and avoid damage to the vasculature. Due to ultrasound Doppler angle dependencies and the complexity of the vascular architecture, clinically valuable 3-D flow direction information is currently not available. In this paper, we aim to clinically validate and demonstrate the intraoperative use of a fully automatic method for estimation of 3-D blood flow direction from freehand 2-D Doppler ultrasound.

Methods

A 3-D vessel model is reconstructed from 2-D Doppler ultrasound and used to determine the vessel architecture. The blood flow direction is then estimated automatically using the model in combination with Doppler velocity data. To enable testing and validation during surgery, the method was implemented as part of the open-source navigation system CustusX (www.custusx.org).

Results

Ten patients were included prospectively. Data from four patients were processed postoperatively, and data from six patients were processed intraoperatively. In total, the blood flow direction was estimated for 48 different blood vessels with a success rate of 98%.

Conclusions

In this work, we have shown that the proposed method is suitable for fully automatic estimation of the blood flow direction in intracranial vessels during neurosurgical interventions. The method has the potential to make the understanding of the complex vascular anatomy and flow pattern more intuitive for the surgeon. The method is compatible with intraoperative use, and results can be presented within the limited time frame where they still are of clinical interest.

Reliability and correlation analysis of computed methods to convert conventional 2D radiological hindfoot measurements to a 3D setting using weightbearing CT

Abstract

Purpose

The exact radiographic assessment of the hindfoot alignment remains challenging. This is reflected in the different measurement methods available. Weightbearing CT (WBCT) has been demonstrated to be more accurate in hindfoot measurements. However, current measurements are still performed in 2D. This study wants to assess the use of computed methods to convert the former uniplanar hindfoot measurements obtained after WBCT towards a 3D setting.

Methods

Forty-eight patients, mean age of 39.6 ± 13.2 years, with absence of hindfoot pathology were included. A WBCT was obtained, and images were subsequently segmented and analyzed using computer-aided design operations. In addition to the hindfoot angle (HA), other ankle and hindfoot parameters such as the anatomical tibia axis, talocalcaneal axis (TCA), talocrural angle, tibial inclination (TI), talar tilt, and subtalar vertical angle were determined in 2D and 3D.

Results

The mean \(\hbox {HA}_{2\mathrm{D}}\) was \(0.79^{\circ }\) of valgus ± 3.2 and the \(\hbox {HA}_{\mathrm{3D}}\) was \(8.08^{\circ }\) of valgus ± 6.5. These angles differed significantly from each other with a \(P<0.001\) . The correlation between both showed to be good by \(\hbox {a}\) Pearson correlation coefficient (r) of 0.72 ( \(P < 0.001\) ). The \(\hbox {ICC}_{\mathrm{3D}}\) showed to be excellent when compared to the \(\hbox {ICC}_{\mathrm{2D}}\) , which was good. Similar findings were obtained in other angles. The highest correlation was seen between the \(\hbox {TI}_{\mathrm{2D}}\) and \(\hbox {TI}_{\mathrm{3D}}\) (r = 0.83, \(P < 0.001\) ) and an almost perfect agreement in the \(\hbox {TCA}_\mathrm{3D}\) ( \(\hbox {ICC}_{\mathrm{3D}}=0.99\) ).

Conclusion

This study shows a good and reliable correlation between the \(\hbox {HA}_{\mathrm{2D}}\) and \(\hbox {HA}_{\mathrm{3D}}\) . However, the \(\hbox {HA}_{\mathrm{3D}}\) overcomes the shortcomings of inaccuracy and provides valuable spatial data that could be incorporated during computer-assisted surgery to assess the multiplanar correction of a hindfoot deformity.

Motion-invariant SRT treatment detection from direct M-scan OCT imaging

Abstract

Purpose

Selective retina therapy (SRT) is a laser treatment targeting specific posterior retinal layers. It is focused on inducing damage to the retinal pigment epithelium (RPE), while sparing other retinal tissue compared to traditional photocoagulation. However, the targeted RPE layer is invisible with most imaging modalities and induced SRT lesions cannot be monitored. In this work, imaging scans acquired from an experimental setup that couples the SRT laser beam with an optical coherence tomography (OCT) beam are analyzed in order to evaluate the treatment as they occur.

Methods

We isolated a small part of the time-resolved scan corresponding to the end of the treatment, for which we have microscopic evidence of the SRT outcome. We then use a convolutional neural network to correspond each scan to the treatment result. We explore which aspects of the scan convey more valuable information for a robust therapy evaluation. By only using this adequately small part, we can achieve an online estimation, while being resilient to eye movement.

Results

The available dataset consists of time- resolved OCT scans of 98 ex vivo porcine eyes, treated with different energy levels. The proposed method yields high performance in the task of predicting whether the applied energy was adequate for SRT treatment, by focusing on the immediate OCT signal acquired during treatment time.

Conclusions

We propose a strategy toward online noninvasive SRT treatment assessment, able to provide a satisfying evaluation of a treatment status, that therefore could be used for the planning of the treatment continuation.

A linear stepping endovascular intervention robot with variable stiffness and force sensing

Abstract

Background/purpose

Robotic-assisted endovascular intervention surgery has attracted significant attention and interest in recent years. However, limited designs have focused on the variable stiffness mechanism of the catheter shaft. Flexible catheter needs to be partially switched to a rigid state that can hold its shape against external force to achieve a stable and effective insertion procedure. Furthermore, driving catheter in a similar way with manual procedures has the potential to make full use of the extensive experience from conventional catheter navigation. Besides driving method, force sensing is another significant factor for endovascular intervention.

Methods

This paper presents a variable stiffness catheterization system that can provide stable and accurate endovascular intervention procedure with a linear stepping mechanism that has a similar operation mode to the conventional catheter navigation. A specially designed shape-memory polymer tube with water cooling structure is used to achieve variable stiffness of the catheter. Hence, four FBG sensors are attached to the catheter tip in order to monitor the tip contact force situation with temperature compensation.

Results

Experimental results show that the actuation unit is able to deliver linear and rotational motions. We have shown the feasibility of FBG force sensing to reduce the effect of temperature and detect the tip contact force. The designed catheter can change its stiffness partially, and the stiffness of the catheter can be remarkably increased in rigid state. Hence, in the rigid state, the catheter can hold its shape against a \(1.8 \, \hbox {N} \,\hbox {cm}\) load. The prototype has also been validated with a vascular phantom, demonstrating the potential clinical value of the system.

Conclusion

The proposed system provides important insights into the design of compact robotic-assisted catheter incorporating effective variable stiffness mechanism and real-time force sensing for intraoperative endovascular intervention.

A cable-driven parallel manipulator with force sensing capabilities for high-accuracy tissue endomicroscopy

Abstract

Purpose

Endomicroscopy (EM) provides high resolution, non-invasive histological tissue information and can be used for scanning of large areas of tissue to assess cancerous and pre-cancerous lesions and their margins. However, current robotic solutions do not provide the accuracy and force sensitivity required to perform safe and accurate tissue scanning.

Methods

A new surgical instrument has been developed that uses a cable-driven parallel mechanism (CPDM) to manipulate an EM probe. End-effector forces are determined by measuring the tensions in each cable. As a result, the instrument allows to accurately apply a contact force on a tissue, while at the same time offering high resolution and highly repeatable probe movement.

Results

0.2 and 0.6 N force sensitivities were found for 1 and 2 DoF image acquisition methods, respectively. A back-stepping technique can be used when a higher force sensitivity is required for the acquisition of high quality tissue images. This method was successful in acquiring images on ex vivo liver tissue.

Conclusion

The proposed approach offers high force sensitivity and precise control, which is essential for robotic EM. The technical benefits of the current system can also be used for other surgical robotic applications, including safe autonomous control, haptic feedback and palpation.

Convolution neural networks for real-time needle detection and localization in 2D ultrasound

Abstract

Purpose

We propose a framework for automatic and accurate detection of steeply inserted needles in 2D ultrasound data using convolution neural networks. We demonstrate its application in needle trajectory estimation and tip localization.

Methods

Our approach consists of a unified network, comprising a fully convolutional network (FCN) and a fast region-based convolutional neural network (R-CNN). The FCN proposes candidate regions, which are then fed to a fast R-CNN for finer needle detection. We leverage a transfer learning paradigm, where the network weights are initialized by training with non-medical images, and fine-tuned with ex vivo ultrasound scans collected during insertion of a 17G epidural needle into freshly excised porcine and bovine tissue at depth settings up to 9 cm and \(40^{\circ }\) – \(75^{\circ }\) insertion angles. Needle detection results are used to accurately estimate needle trajectory from intensity invariant needle features and perform needle tip localization from an intensity search along the needle trajectory.

Results

Our needle detection model was trained and validated on 2500 ex vivo ultrasound scans. The detection system has a frame rate of 25 fps on a GPU and achieves 99.6% precision, 99.78% recall rate and an \({F}_{1}\) score of 0.99. Validation for needle localization was performed on 400 scans collected using a different imaging platform, over a bovine/porcine lumbosacral spine phantom. Shaft localization error of \(0.82^{\circ }\pm 0.4^{\circ }\) , tip localization error of \(0.23\pm 0.05\) mm, and a total processing time of 0.58 s were achieved.

Conclusion

The proposed method is fully automatic and provides robust needle localization results in challenging scanning conditions. The accurate and robust results coupled with real-time detection and sub-second total processing make the proposed method promising in applications for needle detection and localization during challenging minimally invasive ultrasound-guided procedures.

Planning nonlinear access paths for temporal bone surgery

Abstract

Purpose

Interventions at the otobasis operate in the narrow region of the temporal bone where several highly sensitive organs define obstacles with minimal clearance for surgical instruments. Nonlinear trajectories for potential minimally invasive interventions can provide larger distances to risk structures and optimized orientations of surgical instruments, thus improving clinical outcomes when compared to existing linear approaches. In this paper, we present fast and accurate planning methods for such nonlinear access paths.

Methods

We define a specific motion planning problem in \(\mathrm{SE}(3)=\mathbb {R}^3\times \mathrm{SO(3)}\)  with notable constraints in computation time and goal pose that reflect the requirements of temporal bone surgery. We then present \(\kappa \) -RRT-Connect: two suitable motion planners based on bidirectional Rapidly exploring Random Tree (RRT) to solve this problem efficiently.

Results

The benefits of \(\kappa \) -RRT-Connect are demonstrated on real CT data of patients. Their general performance is shown on a large set of realistic synthetic anatomies. We also show that these new algorithms outperform state-of-the-art methods based on circular arcs or Bézier–Splines when applied to this specific problem.

Conclusion

With this work, we demonstrate that preoperative and intra-operative planning of nonlinear access paths is possible for minimally invasive surgeries at the otobasis.

Surgical skills: Can learning curves be computed from recordings of surgical activities?

Abstract

Purpose

Surgery is one of the riskiest and most important medical acts that are performed today. The need to improve patient outcomes and surgeon training, and to reduce the costs of surgery, has motivated the equipment of operating rooms with sensors that record surgical interventions. The richness and complexity of the data that are collected call for new methods to support computer-assisted surgery. The aim of this paper is to support the monitoring of junior surgeons learning their surgical skill sets.

Methods

Our method is fully automatic and takes as input a series of surgical interventions each represented by a low-level recording of all activities performed by the surgeon during the intervention (e.g., cut the skin with a scalpel). Our method produces a curve describing the process of standardization of the behavior of junior surgeons. Given the fact that junior surgeons receive constant feedback from senior surgeons during surgery, these curves can be directly interpreted as learning curves.

Results

Our method is assessed using the behavior of a junior surgeon in anterior cervical discectomy and fusion surgery over his first three years after residency. They revealed the ability of the method to accurately represent the surgical skill evolution. We also showed that the learning curves can be computed by phases allowing a finer evaluation of the skill progression.

Conclusion

Preliminary results suggest that our approach constitutes a useful addition to surgical training monitoring.

In vitro assessment of the accuracy of digital impressions prepared using a single system for full-arch restorations on implants

Abstract

Purpose

This study describes a method for measuring the accuracy of the virtual impression.

Methods

In vitro measurements according to a metrological approach were based on (1) use of an opto-mechanical coordinate measuring machine to acquire 3D points from a master model, (2) the mathematical reconstruction of regular geometric features (planes, cylinders, points) from 3D points or an STL file, and (3) consistent definition and evaluation of position and distance errors describing scanning inaccuracies. Two expert and two inexpert operators each made five impressions. The 3D position error, with its relevant X, Y, and Z components, the mean 3D position error of each scanbody, and the intra-scanbody distance error were measured using the analysis of variance and the Sheffe's test for multiple comparison.

Results

Statistically significant differences in the accuracy of the impression were observed among the operators for each scanbody, despite the good reliability (Cronbach's \(\alpha \) = 0.897). The mean 3D position error of the digital impression was between 0.041 ± 0.023 mm and 0.082 ± 0.030 mm.

Conclusions

Within the limitations of this in vitro study, which was performed using a single commercial system for preparing digital impressions and one test configuration, the data showed that the digital impressions had a level of accuracy comparable to that reported in other studies, and which was acceptable for clinical and technological applications. The distance between the individual positions (#36 to #46) of the scanbody influenced the magnitude of the error. The position error generated by the intraoral scanner was dependent on the length of the arch scanned. Operator skill and experience may influence the accuracy of the impression.

Use the force: deformation correction in robotic 3D ultrasound

Abstract

Purpose

Ultrasound acquisitions are typically affected by deformations due to the pressure applied onto the contact surface. While a certain amount of pressure is necessary to ensure good acoustic coupling and visibility of the anatomy under examination, the caused deformations hinder accurate localization and geometric analysis of anatomical structures. These complications have even greater impact in case of 3D ultrasound scans as they limit the correct reconstruction of acquired volumes.

Methods

In this work, we propose a method to estimate and correct the induced deformation based solely on the tracked ultrasound images and information about the applied force. This is achieved by modeling estimated displacement fields of individual image sequences using the measured force information. By representing the computed displacement fields using a graph-based approach, we are able to recover a deformation-less 3D volume.

Results

Validation is performed on 30 in vivo human datasets acquired using a robotic ultrasound framework. Compared to ground truth, the presented deformation correction shows errors of \(3.39 \, \pm \, 1.86\,\hbox {mm}\) for an applied force of 5 N at a penetration depth of 55 mm.

Conclusion

The proposed technique allows for the correction of deformations induced by the transducer pressure in entire 3D ultrasound volumes. Our technique does not require biomechanical models, patient-specific assumptions or information about the tissue properties; it can be employed based on the information from readily available robotic ultrasound platforms.

Correction to: Nonlinear deformation of tractography in ultrasound-guided low-grade gliomas resection

Abstract

The author would like to include grant number of NSERC Discovery grant in the acknowledgement section of the original article.

Cutaneous posttransplantation lymphoma: clinical features and survival outcomes

The Effect of Psoriatic Arthritis on Ixekizumab Clinical Outcomes in Moderate-to-Severe Psoriasis Patients: A Post Hoc Analysis

Demographics and Outcomes of Microcystic Adnexal Carcinoma

Hair wax for preservation of eyebrows during laser tattoo removal

Ustekinumab treatment is associated with decreased systemic and vascular inflammation in patients with moderate to severe psoriasis: Feasibility study using 18F-fluorodeoxyglucose positron emission tomography-computed tomography

Psoriasis may be associated with metabolic syndrome and an increased risk of cardiovascular disease.; Patients with psoriasis had increased hepatic, splenic, and arterial inflammation, which decreased with ustekinumab therapy.; Ustekinumab treatment was significantly associated with decreased systemic and vascular inflammation related to metabolic syndrome and cardiovascular disease among patients with psoriasis.

Mycoplasma pneumoniae-related erythema multiforme: clinical and histological features. A single center series of 33 cases compared to 100 cases induced by other causes

Clinical aspects of Mycoplasma pneumoniae-related erythema multiforme (MP-EM) have been poorly described, MP-EM has a distinctive presentation compared with non-MP EM with diffuse atypical targets, and severe and extensive mucositis. Histology is similar to toxic epidermal necrolysis. Mucosal involvement management is essential in MP-EM to prevent possible sequelae.

The Timing and Distribution of Non-Scalp Hair Loss in Patients with Lichen Planopilaris and Frontal Fibrosing Alopecia: A Survey-Based Study

Acute effects of PM 2.5 on lung function parameters in schoolchildren in Nanjing, China: a panel study

Abstract

The association between exposure to ambient particulate matter (PM) and reduced lung function parameters has been reported in many works. However, few studies have been conducted in developing countries with high levels of air pollution like China, and little attention has been paid to the acute effects of short-term exposure to air pollution on lung function. The study design consisted of a panel comprising 86 children from the same school in Nanjing, China. Four measurements of lung function were performed. A mixed-effects regression model with study participant as a random effect was used to investigate the relationship between PM_2.5 and lung function. An increase in the current day, 1-day and 2-day moving average PM_2.5 concentration was associated with decreases in lung function indicators. The greatest effect of PM_2.5 on lung function was detected at 1-day moving average PM_2.5 exposure. An increase of 10 μg/m³ in the 1-day moving average PM_2.5 concentration was associated with a 23.22 mL decrease (95% CI: 13.19, 33.25) in Forced Vital Capacity (FVC), a 18.93 mL decrease (95% CI: 9.34, 28.52) in 1-s Forced Expiratory Volume (FEV₁), a 29.38 mL/s decrease (95% CI: -0.40, 59.15) in Peak Expiratory Flow (PEF), and a 27.21 mL/s decrease (95% CI: 8.38, 46.04) in forced expiratory flow 25–75% (FEF_25–75%). The effects of PM_2.5 on lung function had significant lag effects. After an air pollution event, the health effects last for several days and we still need to pay attention to health protection.

Heavy metal accumulation by Corchorus olitorius L. irrigated with wastewater

Abstract

Many agricultural soils in Egypt irrigated with untreated wastewater. Herein, we investigated the effect of untreated industrial wastewater irrigation on the soil and fodder plant Corchorus olittorius (Jew mallow). It also aimed to assess its effect on the growth measurements as well as analyses of soils, irrigation waters, and plants for heavy metal and nutrient concentrations. Significant differences between irrigation waters and soil irrigated with fresh and wastewater were recognized. Wastewater irrigation leads to remarkable reduction in the growth parameters and reduced its vegetative biomass. The concentration of Pb, Cd, Cr, Cu, Fe, and Zn were high significant and above phytotoxic concentrations in leaves (edible part) and roots of wastewater-irrigated plant. The present study indicated that Jew mallow plant tends to phytostabilize (Cd, Ni, and Mn) in its root and had the ability to translocate (Pb, Cu, Cr, Fe, and Zn) to its leaves. Higher concentrations of Cd, Cu, Cr, Pb, Fe, Mn, Ni, and Zn in the roots than leaves indicate that the roots are hyper-accumulators for Pb, Cr, Cu, Fe, and Zn more than the leaves. The research study recommended that there is a need to protect the soil from contamination through regular monitoring and not to cultivate Jew mallow in wastewater-irrigated soil and that it had a high capacity to accumulate heavy metals in its edible part and causes several harmful health effects for consumers.

Influence of laser therapy on the dynamic formation of extracellular matrix in standard second degree burns treated with bacterial cellulose membrane

Publication date: Available online 16 March 2018
Source:Journal of Photochemistry and Photobiology B: Biology
Author(s): Patricia Keler Freitas Machado Vasconcellos, Manuela Pimentel Nóia, Isabele Cardoso Vieira De Castro, Jean Nunes dos Santos, Antonio Luiz B. Pinheiro, Aparecida Maria Cordeiro Marques, Eduardo Antonio Gonçalves Ramos, Clarissa Gurgel Rocha
The present study aims to assess the influence of Aluminum-Gallium-Indium-Phosphide laser (AlGaInP laser, λ = 660 nm), whether or not in association with the application of a membrane of bacterial cellulose (Nexfill™), during recovery from induced second-degree burns at the dorsum of Wistar rats. (Rattus norvegicus, Wistar). Forty-eight animals have been distributed into four groups: Control (burns remained untreated), Group I (laser-treated), Group II (treated with Nexfill), and Group III (laser + Nexfill™). In addition to a morphological analysis, immunohistochemical analysis has been performed for type I collagen, type III collagen, fibronectin, and laminin. The Fisher's Test was used to assess differences among groups (p < 0,05). A larger amount of collagen type III was observed in Control, Group II and Group III when compared with Group I (p < 0,05). Group I and Group III have shown a greater collagen deposition when compared with Group II (p < 0,05), but the amount of collagen was similar in Group I, Group III, and Control. Group III has shown larger fibronectin amounts in comparison with Group II (p < 0,05). As regards laminin, Group I has shown a predominant discontinuity pattern on the basal lamina in comparison with Control, Group II, and Group III (p < 0,05). It is concluded that in this current study the laser when used alone (Group I) hasn't influenced collagen deposition neither has it acted on fiber pattern (fibril and/or reticular). Moreover, laser application hasn't accelerated the repair of wounds caused by inflicted second-degree burns.

Correction to: The Effect of What We Think may Happen on our Judgments of Responsibility

Abstract

On pages 263, 265, and 266, incorrect degrees of freedom and t values were reported. The statistical conclusions are not affected by these reporting errors, but the corrected values are shown below.

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 1-1, March 2018....

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 1-1, March 2018.

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 31-31, March 2018....

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 31-31, March 2018.

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 2-30, March 2018....

JDDG: Journal der Deutschen Dermatologischen Gesellschaft, Volume 16, Issue S1, Page 2-30, March 2018.

Aquatic plants for phytostabilization of cadmium and zinc in hydroponic experiments

Abstract

Cadmium (Cd) may be toxic to aquatic plants even at modest concentrations, and excessive quantities of zinc (Zn) decrease plant performance. The Cd and Zn phytoremediation potential of several aquatic plant species (Thalia geniculate, Cyperus alternifolius, Canna indica, Eichhornia crassipes, Pistia stratiotes) and one grass species (Vetiveria zizanioides) was evaluated in hydroponic experiments. Vetiveria zizanioides, E. crassipes, and P. stratiotes experienced reduced growth performance in the presence of Cd as determined from biomass production, survival rate, and crown root number (CN); however, they accumulated high quantities of metals in their tissues, particularly in roots. Root accumulation is considered a key characteristic of so-called excluder species. In this study, only E. crassipes and P. stratiotes had bioconcentration factors and translocation factors (> 1000 and < 1, respectively) suitable for high phytostabilization of Cd. Furthermore, V. zizanioides and P. stratiotes showed the highest percent metal uptake from solution and removal capacity for Zn (~70% and ~2 mg d⁻¹ g⁻¹, respectively). Emergent aquatic species (particularly C. alternifolius and T. geniculate) adapted and lived well in Cd- and Zn-contaminated solution and took up high quantities of Cd and Zn in roots, and are therefore considered strong excluders. Beneficial uses of such species in contaminated wetlands include stabilizing toxic metals and limiting erosion. Plant tissue can be applied to other uses, including as a biomass fuel. In field situations, the candidate species may work best when grown together, since each plant genotype possesses a different potential to control Cd and Zn.

Polyvinyl alcohol-based nanocomposite hydrogels containing magnetic laponite RD to remove cadmium

Abstract

In this study, magnetic nanocomposite hydrogels based on polyvinyl alcohol were synthesized. Magnetic polyvinyl alcohol/laponite RD (PVA-mLap) nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The results indicated that PVA-mLap had desirable magnetic-sorption properties and magnetic-laponite nanoparticles were successfully synthesized and added to polyvinyl alcohol. The present nanocomposites were applied to remove Cd²⁺ from aqueous solution. The influence of initial Cd²⁺ concentration, magnetic-laponite concentration, pH, and ionic strength on adsorption isotherm was investigated. Heterogeneity of adsorption sites was intensified by increasing magnetic concentration of adsorbents and by rising pH value. Results of ionic strength studies indicated that by increasing ionic strength more than four times, the adsorption of Cd²⁺ has only decreased around 15%. According to the results, the dominant mechanism of Cd²⁺ sorption by the present adsorbents was determined chemical and specific sorption. Therefore, the use of the present nanocomposites as a powerful adsorbent of Cd²⁺ in the wastewater treatment is suggested. Isotherm data were described by using Freundlich and Langmuir models, and better fitting was introduced Langmuir model.

Grounding and metaphysical explanation: it’s complicated

Abstract

Grounding theorists insist that grounding and explanation are intimately related. This claim could be understood as saying either that grounding 'inherits' its properties from (metaphysical) explanation (and that, therefore, contemplating the nature of explanation informs us about the nature of grounding) or it could be interpreted as saying that grounding plays an important—possibly an indispensable—role in metaphysical explanation (and that, therefore, that there are these explanations justifies positing grounding). Or both. I argue that saying that grounding 'inherits' its properties from explanation can only be justified if grounding is explanatory by nature (if so-called 'unionism' is true), but that this view is untenable. We ought therefore to be 'separatists' and view grounding and explanation as distinct. As it turns out, though, once grounding has been in this sense distinguished from the explanation it backs, the view that the role grounding plays in explanation justifies its introduction ends up in serious trouble. I conclude that the role grounding plays in explanation (if any) does not justify attributing to grounding whatever nature we think it has, and it most likely does not give us any special reason to think grounding exists.

Regulation of expression of a select group of Bacillus anthracis spore coat proteins

Abstract

The spore coat of Bacilli is a relatively complex structure comprised of about 70 species of proteins in 2 or 3 layers. While some are involved in assembly or protection, the regulation of many are not well defined so lacZ transcriptional fusions were constructed to six Bacillus anthracis spore coat genes in order to gain insight into their possible functions. The genes were selected on the basis of the location of the encoded proteins within the coat and distribution among spore forming species. Conditions tested were temperature and media either as solid or liquid. The most extensive differences were for the relatively well expressed fusions to the cotH and cotM genes which were greatest at 30°C on plates of a nutrient rich medium. The cotJ operon was moderately expressed under all conditions although somewhat higher on enriched plates at 30°C. Cot S was low under all conditions except for a substantial increase in biofilm medium. Cot$\infty $ and cotF were essentially invariant with a somewhat greater expression in the more enriched medium. The capacity of a subset of coat genes to respond to various conditions reflects a flexibility in spore coat structure which may be necessary for adaptation to environmental challenges. This could account, atleast in part, for the complexity of this structure.

On not getting out of bed

Abstract

This morning I intended to get out of bed when my alarm went off. Hearing my alarm, I formed the intention to get up now. Yet, for a time, I remained in bed, irrationally lazy. It seems I irrationally failed to execute my intention. Such cases of execution failure (as I call it) pose a challenge for Mentalists about rationality, who believe that facts about rationality supervene on facts about the mind. For, this morning, my mind was in order; it was my (in)action that apparently made me irrational. What, then, should Mentalists say about the phenomenon of execution failure? The phenomenon of execution failure, and the puzzle it raises for Mentalists, have rarely been discussed. This paper addresses the puzzle in two parts. First, it argues (against John Broome) that execution failure is a real phenomenon. It is possible for agents to irrationally fail to act on their present-directed intentions. It follows that Mentalists in the philosophy of action must solve the puzzle of explaining what is irrational about cases of execution failure. Second, this paper begins the search for such a solution. It considers six possible resolutions to the puzzle, arguing that none is obviously the most attractive. These resolutions include a requirement of overall conative consistency, an appeal to the norm of intention consistency, a form of Volitionalism, an appeal to factive mental states, and a proposal due to Garrett Cullity, and a novel requirement of proper functioning.

Improvements in Modelling Bystander and Resident Exposure to Pesticide Spray Drift: Investigations into New Approaches for Characterizing the ‘Collection Efficiency’ of the Human Body

Abstract

The BREAM (Bystander and Resident Exposure Assessment Model) (Kennedy et al. in BREAM: A probabilistic bystander and resident exposure assessment model of spray drift from an agricultural boom sprayer. Comput Electron Agric 2012;88:63–71) for bystander and resident exposure to spray drift from boom sprayers has recently been incorporated into the European Food Safety Authority (EFSA) guidance for determining non-dietary exposures of humans to plant protection products. The component of BREAM, which relates airborne spray concentrations to bystander and resident dermal exposure, has been reviewed to identify whether it is possible to improve this and its description of variability captured in the model. Two approaches have been explored: a more rigorous statistical analysis of the empirical data and a semi-mechanistic model based on established studies combined with new data obtained in a wind tunnel. A statistical comparison between field data and model outputs was used to determine which approach gave the better prediction of exposures. The semi-mechanistic approach gave the better prediction of experimental data and resulted in a reduction in the proposed regulatory values for the 75th and 95th percentiles of the exposure distribution.

Dermalive Facial Filler Granulomas Masquerading as Neurofibromas

A 56-year-old woman presented with periocular nodules that were clinically suspected to be neurofibromas. Histopathologic examination of excised nodules revealed a pronounced granulomatous reaction to a foreign material that was composed of glossy polygonal palely eosinophilic fragments. These fragments were outlined in red with Masson trichrome, stained gray with the elastic stain, and were uniformly red with Gomori methenamine silver staining. The histopathologic appearance was consistent with a granulomatous reaction to Dermalive facial filler. Postoperatively the patient admitted that she had filler injections many years earlier in another country, and that nodules appeared 1 year after injection. Treatment with steroids, intralesional immunosuppressive agents and surgery had been previously attempted to eradicate the nodules. The literature pertaining to granulomatous reactions to Dermalive and related hybrid facial fillers is reviewed and treatment options are discussed. This report is the first to illustrate the unique histopathologic staining characteristics of Dermalive, which may be useful to ophthalmic pathologists in identifying this uncommon foreign material. Accepted for publication January 31, 2018. Heed Fellowship was awarded to N.W. The authors have no conflicts of interest to disclose. Address correspondence and reprint requests to Frederick A. Jakobiec, M.D., D.Sc., David G. Cogan Laboratory of Ophthalmic Pathology, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Suite 328, Boston, MA 02114. E-mail: Fred_Jakobiec@meei.harvard.edu. © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

Frontalis Muscle Contraction and the Role of Visual Deprivation and Eyelid Proprioception

Purpose: To determine if frontalis muscle contraction can be induced by manipulating visual and eyelid proprioceptive inputs through simulating visual deprivation and ptosis. Methods: Volunteers without prior eyelid or forehead pathologic study were recruited for this nonrandomized, prospective study. Baseline and study phase brow positions were documented. The first phase was to simulate visual deprivation and the second to simulate ptosis. The dominant eye was used for each phase. As a proxy to simulate visual field deprivation, a black contact lens was placed on the eye, which reduced vision to light perception. As a proxy to simulate ptosis, an external eyelid weight was placed on the upper eyelid. Brow position ratios were calculated at various points along the brow and statistical analysis was performed. Results: Fifteen subjects participated. The average brow position ratio was 1.00 ± 0.08 for the visual deprivation group, which was not different from baseline (p = 0.86). The average brow position ratio for the external eyelid weight group was 1.13 ± 0.07, which was statistically significant compared with baseline and the visual deprivation group (p

Primary Eyelid Amyloidosis Presenting as a Calcified Plaque: A Rare Presentation

No abstract available

Quantitative Assessment of Dry Eye Parameters After Muller’s Muscle-Conjunctival Resection

Purpose: Muller's muscle-conjunctival resection (MMCR) is a highly effective technique to correct upper eyelid ptosis. However, several authorities have raised concerns about the possibility of postoperative ocular surface dryness. This study was performed to assess the impact of MMCR on clinically meaningful parameters of the ocular surface. Methods: In adult patients, tear break-up time, lipid layer thickness, and osmolarity were measured via direct observation, interferometry, and impedance measurements before surgery and 3 months after surgery in patients who underwent MMCR. Statistical analysis was performed via a dedicated software package. Results: Fifteen eyes of 14 patients were included in the study. Mean pre- and postoperative tear break-up times were 12.71 ± 2.20 and 12.43 ± 2.41 seconds, respectively (p = 0.1648). Preoperatively, the mean lipid layer thickness measurement was 91.00 ± 7.02 nm, whereas the mean postoperative value was 88.86 ± 21.36 nm (p = 0.6613). The mean preoperative tear osmolarity measured 291.4 ± 8.86 mOsm/l, and the mean postoperative measurement was 289.86 ± 9.74 mOsm/l (p = 0.2652). Conclusions: MMCR does not appear to change clinically meaningful ocular surface disease parameters, and postoperative dryness did not result from this procedure. In appropriately selected patients, MMCR can be safely performed without increased concerns regarding postoperative dry eye disease. Accepted for publication February 4, 2018. The research adhered to the tenets of the Declaration of Helsinki as amended in 2008. The abstract of this manuscript has been presented at the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) Annual Meeting, American Academy of Ophthalmology, New Orleans, Louisiana, November 10, 2017 Fall Scientific Symposium. The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to: Sana Ali Bautista, M.D., Department of Ophthalmology, Albany Medical College, 43 New Scotland Avenue, Albany, NY 12208. E-mail: alis4@amc.edu © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

A Simple Quantitative Measure of Orbital Compliance

Purpose: This study evaluates the reliability of a frequently used subjective measurement of orbital compliance (0–3 scale) and describes a simple, quantitative measure with excellent intra- and interrater reliability. Methods: Two examiners performed both measurements on 100 orbits (50 consecutive patients) from the office of 1 oculoplastics surgeon. Each measurement was obtained at 2 different time points, 10 minutes apart. For the subjective measurement, the patient was asked to close their eyes, and the globe was displaced posteriorly with digital pressure until moderate resistance was felt. This was graded on a 0 to 3 scale. For the quantitative measurement (millimeter scale), the difference in axial displacement was measured using a Hertel exophthalmometer. Results: The subjective measurement (scale, 0–3) showed excellent test–retest reliability (average, 0.901) for both examiners at both time points and good interobserver reliability (average, 0.677). The quantitative measurement (millimeter scale) showed excellent test–retest reliability (average, 0.848) and very good interobserver reliability (average, 0.756). Conclusion: This study shows that while both methods have both excellent test–retest reliability, the interobserver reliability is slightly higher with the quantitative measurement. This suggests that the described measurement of orbital compliance is both a reasonable alternative and possibly more accurate measurement without the steep learning curve. Accepted for publication January 31, 2018. A consent was obtained and is on file for the figure used in the paper. Supported by an unrestricted grant from Research to Prevent Blindness to Columbia University School of Medicine. The authors have no financial or conflicts of interest to disclose. This work has not been published or presented at any meeting previously. Address correspondence and reprint requests to: Michael Kazim, M.D., Harkness Eye Institute, Columbia University Medical Center, 635 West 165th Street, New York, NY 10032. E-mail: mk48@cumc.columbia.edu © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

Orbital and Ocular Ischemic Syndrome With Blindness After Facial Filler Injection

The authors herein describe a case of orbital and ocular ischemic syndrome with blindness after cosmetic hyaluronic acid filler injection. Orbital function, but not visual function, returned after treatment with orbital hyaluronidase and corticosteroids. Accepted for publication February 4, 2018. The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to Sathyadeepak Ramesh, M.D., UCLA Stein Eye Institute, 300 Stein Plaza, Los Angeles, CA 90095. E-mail: Sathyadeepak.Ramesh@gmail.com © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

Orbital Plates and Screws Causing Globe Fixation: A Rare and Delayed Complication of Craniomaxillofacial Surgery

A 24-year-old woman presented with a 1-year history of gradually increasing pain on eye movements, worse on the right. She had a significant background of undergoing intracranial correction of orbital hypertelorism with internal fixation of the lateral orbital rims at the age of 6 years. Imaging was consistent with bilateral metallic foreign bodies from both lateral orbital rims protruding into the globes. The patient underwent removal of bilateral plates and screws, with a significant improvement of symptoms and ocular motility postoperatively. This case demonstrates the need to consider orbital screw/plate migration in the setting of reduced ocular motility and painful eye movements. Accepted for publication January 25, 2018. Written consent was gained from the patient for publication and use of photographs The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to: Varun Chandra, M.B.B.S., Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne, VIC, Australia. E-mail: varun.chandra@hotmail.com © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

Validation of reference genes for reverse transcription real-time quantitative PCR analysis in the deep-sea bacterium Shewanella psychrophila WP2

Abstract

Reference genes are critical to obtain reliable results of reverse transcription real-time quantitative PCR (RT-qPCR), which is widely used for relative quantification of gene expression. In this study, we evaluated the validity of seven candidate reference genes for normalization in RT-qPCR analysis in the deep-sea bacterium Shewanella psychrophila WP2 under different environmental conditions. Among the set of genes investigated, gyrA, 16S rRNA and rho were identified as the most suitable reference genes for WP2 at different temperatures, hydrostatic pressures and salinities, respectively. Notably, the rho gene is conserved in Shewanella genus and other deep-sea bacteria, thus, could be used as a versatile reference gene for RT-qPCR analysis of these microorganisms under extreme environmental conditions.

Fatty acid addition and thermotolerance of Kluyveromyces marxianus

Abstract

Membrane fatty acid composition has an important role in yeast stress resistance, particularly in temperature tolerance. Most studies investigating temperature and membrane fatty acids use the yeast Saccharomyces cerevisiae without considering other yeasts, such as Kluyveromyces marxianus, which has physiological differences and industrial advantages with respect to S. cerevisiae. One of the primary traits of K. marxianus is its thermotolerance. The effect of fatty acid addition (oleic acid, linoleic acid, linolenic acid and araquidic acid) on the thermotolerance of the K. marxianus strain SLP1 was evaluated. SLP1 yeast exhibited temperature tolerance of up to 50°C; at 55°C, viability was reduced significantly, probably due to an increase in the generation of reactive oxygen chemical species. Externally added fatty acids were incorporated in the yeast membrane, increasing their proportion to approximately 70%, thereby changing membrane fluidity. SLP1 cells supplemented with polyunsaturated fatty acids decreased cell thermotolerance and increased the degree of lipoperoxidation, while arachidic acid addition exhibited a tendency to increase yeast thermotolerance.

Variable response of nirK and nirS containing denitrifier communities to long-term pH manipulation and cultivation

Abstract

Denitrification is a key process responsible for the majority of soil nitrous oxide (N₂O) emissions but the influences of pH and cultivation on the soil denitrifier community remain poorly understood. We hypothesised that the abundance and community structure of the total bacterial community and bacterial denitrifiers would be pH sensitive and that nirK and nirS containing denitrifiers would differ in their responses to change in pH and cultivation. We investigated the effect of long-term pH-adjusted soils (ranging from pH 4.2 to 6.6) under different lengths of grass cultivation (one, two and three years of ley grass) on the general bacterial and denitrifier functional communities using 16S rRNA, nirK and nirS genes as markers. Denitrifier abundance increased with pH, and at pH below 4.7 there was a greater loss in nirS abundance per unit drop in pH than soils above this threshold pH. All community structures responded to changes in soil pH, while cultivation only influenced the community structure of nirK. These differences in denitrifier responses highlight the importance of considering both nirK and nirS gene markers for estimating denitrifier activity. Identifying such thresholds in response of the microbial community to changes in pH is essential to understanding impacts of management or environmental change.

Overexpression of the periplasmic nitrate reductase supports anaerobic growth by Ensifer meliloti

Abstract

The alfalfa endosymbiont Ensifer meliloti strain1021 is known to be an incomplete denitrifier due to its inability to grow anoxically using nitrate as respiratory substrate to produce ATP and grow under anoxic conditions. Although this bacterium contains and expresses the complete set of denitrification genes napEFDABC, nirK, norECBQD and nosRZDFYLX encoding the periplasmic nitrate reductase (Nap), Cu-containing nitrite reductase (NirK), c-type nitric oxide (cNor) and nitrous oxide reductase (Nos), respectively, the reasons of its inability to grow under anoxic conditions are still very poorly understood. In the present study, we have constructed an E. meliloti strain overexpressing napEFDABC genes (Nap⁺) and demonstrated that this strain is able to grow through anaerobic nitrate respiration. Furthermore, Nap⁺ showed increased NapC levels as well as Nap, Nir and cNor activities and higher capacity to produce NO and N₂O compared to wild-type cells. These results suggest that the inability of E. meliloti to grow under anaerobic conditions using nitrate as electron acceptor is attributable to a limitation in the expression of the periplasmic nitrate reductase.

Characterization of centriole duplication in human epidermis, Bowen’s disease, and squamous cell carcinoma

The centrosome is the microtubule-organizing center of animal cells. Each cell has one centrosome, comprising a pair of centrioles and the surrounding pericentriolar material (PCM) [1]. Centrosomes are involved in spindle pole assembly, cell polarity, cell migration, and maintenance of cellular stemness [2–4]. Numerical and structural centrosome abnormalities have been observed in many human carcinomas including pre-invasive carcinomas. It remains unclear whether centrosome abnormalities cause, or are a result of, tumorigenesis [5].

Enoxaparin pretreatment effect on local and systemic inflammation biomarkers in the animal burn model

Abstract

Low-molecular weight heparins (LMWH) are anticoagulants that have shown anti-inflammatory activity in several experimental models. Hot water burn inflammatory model accurately simulates human clinical situations allowing its use for nociception test and evaluation of anti-inflammatory drugs. The present study aims to evaluate the enoxaparin pretreatment on local and systemic inflammation biomarkers in the animal burn model. Inflammation was induced by submersing the rat left hind paw in water at 60^o C for 60 s. C-reactive protein (CRP) and thrombin–antithrombin complex (TAT) were estimated by immunosorbent assay, fibrinogen (Fg) by the gravimetric method and paw oedema by orthogonal digital photography. Highest values of paw oedema, CRP and TAT were observed at 4 h post-burn while Fg peak occurs at 12 h post-burn; enoxaparin pretreatment decreased oedema (− 32.1%), and concentration of TAT (− 66.7%), PCR (− 37.9%) and Fg (− 8%). This study shows that enoxaparin has local and systemic anti-inflammatory effects and should be considered as a potential adjuvant drug for the treatment of burns.

Differences between attached and suspended microalgal cells in ssPBR from the perspective of physiological properties

Publication date: Available online 15 March 2018
Source:Journal of Photochemistry and Photobiology B: Biology
Author(s): Zhuang Lin-Lan, Wang Jing-Han, Hu Hong-Ying
Attached microalgae cultivation for the algae-based products is considered as a promising approach to simplify biomass recovery processes and reduce the cost. However, as an incipient research field, biomass accumulation is the mainly index for attached microalgal growth evaluation. To break through such limitations, physiological properties of attached microalgae (e.g. the oxygen evolving activity and the three main organic composition of cells), which are important for microalgal growth evaluation but are still unclear in most studies, were studied using an attached microalgae culture system, i.e. suspended-solid phase photobioreactor (ssPBR) in this paper. As light, nutrients and other environmental conditions of attached microalgae were different from the suspended microalgae, physiological properties of attached microalgae also varied from the suspended ones. Besides the relatively lower biomass accumulation rate, attached microalgae also had a lower oxygen evolving activity (65% on average) comparing to suspended microalgae. The composition of microalgae changed towards accumulating more protein when suspended microalgae turned to attached status. The relative protein content of attached microalgae (50.1% ± 10.1%) was approximately 30% higher than the suspended algae (36.0% ± 16.1%) on average. The discovery of physiological properties of attached microalgae in this paper could help the production of high-protein microalgae-related products and explain some phenomenon during the production of microalgae-related products.

Neo-adjuvant radiotherapy (NART) in breast reconstruction – The future for autologous reconstruction in locally advanced disease?

Publication date: Available online 15 March 2018
Source:Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Pietro G. di Summa, Sherylin K. Tay, Rosemary Stevens, Julie C. Doughty, Russell J. Bramhall

Nanoanalytics: history, concepts, and specificities

Abstract

This article deals with analytical chemistry devoted to nano-objects. A short review presents nano-objects, their singularity in relation to their dimensions, genesis, and possible transformations. The term nano-object is then explained. Nano-object characterization activities are considered and a definition of nanoanalytics is proposed. Parameters and properties for describing nano-objects on an individual scale and on the scale of a population are also presented. They enable the specificities of analytical activities to be highlighted in terms of multi-criteria description strategies and observation scale. Special attention is given to analytical methods, their dimensioning and validation.

Breast cancer brain metastasis: molecular mechanisms and directions for treatment

Abstract

The development of brain metastasis (BM) of breast cancer is usually a late event with deleterious effect on the prognosis. Treatment options for intracerebral seeding of breast cancer are limited and so far, non-specific. Molecular detailing of subsequent events of penetration, seeding and outgrowth in brain is highly relevant for developing therapeutic strategies to treat, or prevent, BM.We scrutinize recent literature for molecules and pathways that are operative in the formation of breast cancer BM. We also summarize current data on therapeutic efforts to specifically address BM of breast cancer. Data on molecular pathways underlying the formation of BM of breast cancer are sketchy and to some extent inconsistent. The molecular make-up of BM differs from that of the primary tumors, and also from metastases at other sites. Current efforts to treat breast cancer BM are limited and drugs used have proven effects on the primary tumors but lack specificity for the intracerebral tumors.More basic research is necessary to better characterize BM of breast cancer. Apart from the identification of drug targets defined by the intracerebral tumors, also targets in the molecular pathways involved in passing the blood-brain-barrier (BBB) and intracerebral tumor cell (TC) growth should be revealed.

Effects of enhanced ultraviolet-B radiation, water deficit, and their combination on UV-absorbing compounds and osmotic adjustment substances in two different moss species

Abstract

A simulation experiment was conducted to explore the influence of enhanced ultraviolet-B (UV-B) radiation, water deficit, and their combination on UV-absorbing compounds and osmotic adjustment substances of mosses Bryum argenteum and Didymodon vinealis isolated from biological soil crusts (BSCs) growing in a revegetated area of the Tengger Desert, China. Four levels of UV-B radiation and two gradients of water regime were employed. Compared with their controls, amounts of total flavonoids, chlorophyll, carotenoids, soluble sugars, and soluble proteins significantly decreased (p < 0.05), but proline content significantly increased (p < 0.05), when exposed to either enhanced UV-B or water deficit. The negative effects of enhanced UV-B were alleviated when water deficit was applied. There were increases in UV-absorbing compounds and osmotic adjustment substances when exposed to a combination of enhanced UV-B and water deficit compared with single stresses, except for the proline content in D. vinealis. In addition, our results also indicated interspecific differences in response to enhanced UV-B, water deficit, and their combination. Compared with B. argenteum, D. vinealis was more resistant to enhanced UV-B and water deficit singly and in combination. These results suggest that the damage of enhanced UV-B on both species might be alleviated by water deficit. This alleviation is important for understanding the response of BSCs to UV-B radiation in future global climate change. This also provides novel insights into assessment damages of UV-B to BSC stability in arid and semiarid regions.

Climate variability and dengue hemorrhagic fever in Southeast Sulawesi Province, Indonesia

Abstract

To determine the association of climatic factors and dengue hemorrhagic fever and to develop the prediction approach of future dengue transmission. The study used totally monthly dengue hemorrhagic fever cases at Health Office Kendari, Southeast Sulawesi, Indonesia. Monthly meteorological data, consisting of temperature, rainfall, and humidity, was obtained from the Meteorology, Climatology and Geophysics Agency in Kendari district. All data analysis, including Spearman and Poisson distribution, was carried out in R Studio (version 3.3.2) utilizing the R statistical language version 2.15. The highest rate of dengue hemorrhagic fever cases was found in January, February, and March. Temperature averages at lag 2 (p = 0.53, p < 0.0001), lag 3 (p = 0.59, p < 0.0001), and lag 4 (p = 0.41, p < 0.01)) correlated with the incident rate of DHF. The average temperature at lag 2 was found to have a positive impact on the incidence of DHF by Poisson function. This study provides preliminary evidence of the influence of climatic factors on dengue transmission.

Site saturation mutagenesis of ribosomal protein L42 at 56th residue and application as a consecutive selection marker for cycloheximide resistance in yeast

Abstract

The 56^th residue of ribosomal protein L42 (Rpl42) determines the sensitivity of yeast cells to the antibiotic cycloheximide (CYH). In this study, we identified the relationship between the 56^th residue of Rpl42 and the function of the ribosome by site saturation mutagenesis. The resulting 20 RPL42 mutants harbouring one of 20 amino acids at the 56^th residue were classified into five groups: sensitive to CYH (RPL42aP); weak resistance (RPL42aA, RPL42aM, RPL42aC, RPL42aN, RPL42aD, RPL42aS, and RPL42aT), moderate resistance (RPL42aL, RPL42aI, RPL42aV, RPL42aG, and RPL42aH), and strong resistance (RPL42aQ, RPL42aE, RPL42aR, and RPL42aK) to CYH; and non-functional (RPL42aF, RPL42aY, and RPL42aW). Three RPL42a mutants from each group, RPL42aA, RPL42aL, and RPL42aQ, were used as CYH-resistant selection marker genes for the sequential transformation of CYH-sensitive yeast. A series of RPL42 mutants conferring different levels of resistance to CYH should be useful for the dose-dependent multiple selection of prototrophic industrial yeasts.

The nature of electron acceptor (MnIV/NO3) triggers differential expression of genes associated with stress and ammonium limitation responses in Shewanella algae C6G3

Abstract

Shewanella algae C6G3 can reduce dissimilatively nitrate into ammonium and manganese-oxide (MnIV) into MnII. It has the unusual ability to produce anaerobically nitrite from ammonium in the presence of MnIV. To gain insight into their metabolic capabilities, global mRNA expression patterns were investigated by RNA-seq and qRT-PCR in cells growing with lactate and ammonium as carbon and nitrogen sources and with either MnIV or nitrate as electron acceptors. Gene exhibiting higher expression levels in the presence of MnIV belonged to functional categories of carbohydrate, coenzyme, lipid metabolisms and inorganic ion transport. Comparative transcriptomic pattern between MnIV and NO₃ revealed that the strain presented an ammonium limitation status with MnIV, despite the presence of non-limiting concentration of ammonium under both culture conditions. In addition, in presence of MnIV, ntrB/nrtC regulators, ammonium channel, nitrogen regulatory protein P-II, glutamine synthetase and asparagine synthetase glutamine dependent genes were over-represented. Under nitrate condition, the expression of genes involved in the synthesis of several amino acids was increased. Finally, expression level of genes associated with the general stress response was also amplified and among them, katE, a putative catalase/peroxidase present on several Shewanella genomes, was highly expressed with a relative median value higher in MnIV condition.

Involvement of AmpG in mediating a dynamic relationship between serine beta-lactamase induction and biofilm forming ability of Escherichia coli

Abstract

AmpG permease is implicated both in beta-lactamase induction as well as peptidoglycan recycling in enterobacterial isolates. Here, physiological studies using molecular genetics show that deletion of AmpG permease dramatically increases beta-lactam susceptibility even in the presence of AmpC, TEM-1 and OXA beta-lactamases. Also, there is an appreciable decrease in the biofilm forming ability of strains lacking this protein. Expression of this permease in excess probably compromises the integrity of the bacterial cells, leading to cell lysis. Based on these results, we propose that AmpGpermease may be used as a potential antibiotic target and its suppression could efficiently inhibit both beta-lactamase induction and biofilm formation.

Functional characterization of the manganese transporter smf2 homologue gene, PsMnt, of Phanerochaete sordida YK-624 via homologous overexpression

Abstract

A homologue gene of the yeast natural resistance–associated macrophage protein (Nramp) family transporter smf2 was identified in the white-rot fungus Phanerochaete sordida YK-624. Relative expression levels of the homologue, designated PsMnt, were roughly equivalent in cultures containing 0 to 1,000 μM Mn(II), a concentration nontoxic to the fungus. In the PsMnt-overexpressing mutant, cellular Mn accumulation and manganese peroxidase (MnP) activity increased significantly in 4-day cultures containing 10 μM MnSO₄. Compared with the wild-type strain, MnP activity in the overexpressing mutants was higher at lower Mn concentrations (specifically 10–15 times higher). These results suggest that PsMnt is a high-affinity Mn transporter involved in cellular Mn accumulation under Mn-deficient conditions. This is the first report of an smf2 homologue in wood rot fungi.

Electrophoretic mobility of Legionella pneumophila serogroups 1 to 14

Abstract

Legionella pneumophila (Lp) is ubiquitous in the aquatic environment and can persist within drinking water distribution systems (DWDS) enabling these systems to serve as a potential source of human infections. Bacterial surface charge, deduced from electrophoretic mobility (EPM), is a well-recognized contributor to microorganism mobility, adherence, and interactions with their surrounding environment. In this study, the EPM of thirty-two Lp strains representing serogroup (sg) 1 to 14 were measured, in 9.15mM KH₂PO₄ at pH 8, to understand cell surface properties that may influence their occurrence within DWDS. EPM measurements indicated the charge of Lp varied widely between serogroups with five distinct clusters, from least to most negatively charged: (i) sg1 to 3, 5, and 12; (ii) sg6, 8, and 10; (iii) sg9 and 13; (iv) sg7, 11, and 14; and (v) sg4. The EPM of sg1 and 4 strains were pH dependent; however, values were constant between pH 6 to 9, a range typical of drinking water, suggesting that EPM differences between Lp serogroups could impact their survival within DWDS. Understanding the ecological importance of Lp surface properties (e.g. in mobility, colonization, resistance to disinfectants, etc.) within DWDS, would aid in mitigation of health risks associated with this water-based pathogen.

Taking it in the Chin: Vitamin K1 for the Prevention of Acneiform Rash

Optimization and characterization of biosurfactant production from kitchen waste oil using Pseudomonas aeruginosa

Abstract

Kitchen waste oil (KWO) from catering industries or households was used as a low-cost carbon source for producing biosurfactants by self-isolated Pseudomonas aeruginosa. Fermentation performance with KWO was superior to those with four other carbon sources, with higher optical density (OD₆₀₀) of 2.33 and lower interfacial tension of 0.57 mN/m. Culture conditions for biosurfactant production were optimized, with optimal pH of 8.0 and nitrogen source concentration of 2.0 g/L, respectively. The results of infrared spectroscopy and liquid chromatography-mass spectrometry (LC-MS) showed that the biosurfactant was a mixture of six rhamnolipid congeners, among which Rha-Rha-C₁₀-C₁₀ and Rha-C₁₀-C₁₀ were the main components, with mass fraction of approximately 34.20 and 50.86%, respectively. The critical micelle concentration (CMC) obtained was 55.87 mg/L. In addition, the rhamnolipids exhibited excellent tolerance to temperature (20–100 °C), pH (6.0–12.0), and salinity (2–20%; w/v) in a wide range, thereby showing good stability to extreme environmental conditions. The rhamnolipids positively affected oil removal from oil sludge and KWO-contaminated cotton cloth, with removal rate of 34.13 and of 30.92%, respectively. Our results demonstrated that biosurfactant production from KWO was promising, with advantages of good performance, low cost and environmental safety.

Correction to: The influencing factors of CO 2 emission intensity of Chinese agriculture from 1997 to 2014

Abstract

The correct name of the 2nd Author is Yusen Luo. The original article has been corrected.

hsa-let-7b-5p facilitates Mycobacterium tuberculosis survival in THP-1 human macrophages by Fas downregulation

Abstract

Tuberculosis continues to be one of the deadliest infectious diseases worldwide. MicroRNAs (miRNAs) are small non-coding entities that play critical role as post-transcriptional regulators and are transcriptionally deregulated upon mycobacterial infection. In this study, we found significant upregulation of hsa-let-7b-5p in Mycobacterium tuberculosis (MTB) infected THP-1 human macrophages. Concomitantly, we detected the reduced level of Fas protein, one of the targets of hsa-let-7b-5p, in MTB-infected THP-1 macrophages. Using luciferase assay, a direct interaction between hsa-let-7b-5p and the Fas 3΄-untranslated region (3΄-UTR) was established. Inhibition of hsa-let-7b-5p augmented the apoptosis of THP-1 cells enabling enhanced clearance of MTB. Our findings suggest that hsa-let-7b-5p helps intracellular survival of MTB in THP-1 cells by downregulating Fas protein level. This highlights hsa-let-7b-5p as a potential therapeutic target for tuberculosis treatment.

Isolation of marine xylene-utilizing bacteria and characterization of Halioxenophilus aromaticivorans gen. nov., sp. nov. and its xylene degradation gene cluster

Abstract

Seven xylene-utilizing bacterial strains were isolated from seawater collected off the coast of Japan. Analysis of 16S rRNA gene sequences indicated that six isolates were most closely related to the marine bacterial genera Alteromonas, Marinobacter or Aestuariibacter. The sequence of the remaining strain, KU68F^T, showed low similarity to the 16S rRNA gene sequences of known bacteria with validly published names, the most similar species being Maricurvus nonylphenolicus strain KU41E^T (92.6% identity). On the basis of physiological, chemotaxonomic and phylogenetic data, strain KU68F^T is suggested to represent a novel species of a new genus in the family Cellvibrionaceae of the order Cellvibrionales within the Gammaproteobacteria, for which the name Halioxenophilus aromaticivorans gen. nov., sp. nov. is proposed. The type strain of Halioxenophilus aromaticivorans is KU68F^T (=JCM 19134^T = KCTC 32387^T). PCR and sequence analysis revealed that strain KU68F^T possesses an entire set of genes encoding the enzymes for the upper xylene methyl-monooxygenase pathway, xylCMABN, resembling the gene set of the terrestrial Pseudomonas putida strain mt-2.

The Generalized Theory of Evolution, January 31–February 3, 2018, Dusseldorf

Newton, Goethe and the Alleged Underdetermination of Ray Optics

Abstract

Did Goethe devise an empirically viable theory of classical ray optics? Or can we at least make use of his ideas to propose one? And if so, does this confront us with an intriguing case of theory underdetermination? In this paper, which is mainly a comment on the recent work of Olaf Müller, I shall address these three questions and argue for 'no, yes, no'. This is in contrast to Müller, who has recently launched a vivid defense of Goethe-style ray optics (Müller in "Mehr Licht. Goethe mit Newton im Streit um die Farben." Fischer, Frankfurt a.M., 2015a; Z Philos Forsch 69(4):569–573, 2015b; Z Philos Forsch 69(4):588–598, 2015c; Br J Hist Philos 24(2):322–346, 2016). Müller aims to give an almost positive answer to all three questions: 'perhaps, yes, yes'. My overall line of argument will be that the rather restricted regime of classical geometrical optics of spectral colors (or ray optics, for short) allows at best for a weak form of transient theory underdetermination that, in turn and more straightforwardly, also allows for a structuralist reading in terms of two structurally equivalent formulations of one and the same theory. However, extending any of the rivaling models of ray optics other than Newton's beyond the mentioned regime and embedding them into physics in total—especially in view of thermodynamics—leads to a contradiction. Hence, Newton's theory is confirmed as the only consistent theoretical interpretation of ray optics.

Interaction Should Guide Management Decisions [LETTERS]

Reply: [LETTERS]

Anatomic Malformations of the Middle and Inner Ear in 22q11.2 Deletion Syndrome: Case Series and Literature Review [HEAD & NECK]

BACKGROUND AND PURPOSE:

The 22q11.2 deletion syndrome is characterized by a heterogenic phenotype, including hearing loss. The underlying cause of hearing loss, especially sensorineural hearing loss, is not yet clear. Therefore, our objective was to describe anatomic malformations in the middle and inner ear in patients with 22q11.2 deletion syndrome.

MATERIALS AND METHODS:

A retrospective case series was conducted in 2 tertiary referral centers. All patients with 22q11.2 deletion syndrome who had undergone CT or MR imaging of the temporal bones were included. Radiologic images were evaluated on predetermined parameters, including abnormalities of the ossicular chain, cochlea, semicircular canals, and vestibule.

RESULTS:

There were 26 patients (52 ears) with a CT or MR imaging scan available. A dense stapes superstructure was found in 18 ears (36%), an incomplete partition type II was suspected in 12 cochleas (23%), the lateral semicircular canal was malformed with a small bony island in 17 ears (33%), and the lateral semicircular canal and vestibule were fused to a single cavity in 15 ears (29%).

CONCLUSIONS:

Middle and inner ear abnormalities were frequently encountered in our cohort, including malformations of the lateral semicircular canal.

Brain Diffusion Abnormalities in Children with Tension-Type and Migraine-Type Headaches [PEDIATRICS]

BACKGROUND AND PURPOSE:

Tension-type and migraine-type headaches are the most common chronic paroxysmal disorders of childhood. The goal of this study was to compare regional cerebral volumes and diffusion in tension-type and migraine-type headaches against published controls.

MATERIALS AND METHODS:

Patients evaluated for tension-type or migraine-type headache without aura from May 2014 to July 2016 in a single center were retrospectively reviewed. Thirty-two patients with tension-type headache and 23 with migraine-type headache at an average of 4 months after diagnosis were enrolled. All patients underwent DWI at 3T before the start of pharmacotherapy. Using atlas-based DWI analysis, we determined regional volumetric and diffusion properties in the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, brain stem, and cerebral white matter. Multivariate analysis of covariance was used to test for differences between controls and patients with tension-type and migraine-type headaches.

RESULTS:

There were no significant differences in regional brain volumes between the groups. Patients with tension-type and migraine-type headaches showed significantly increased ADC in the hippocampus and brain stem compared with controls. Additionally, only patients with migraine-type headache showed significantly increased ADC in the thalamus and a trend toward increased ADC in the amygdala compared with controls.

CONCLUSIONS:

This study identifies early cerebral diffusion changes in patients with tension-type and migraine-type headaches compared with controls. The hypothesized mechanisms of nociception in migraine-type and tension-type headaches may explain the findings as a precursor to structural changes seen in adult patients with chronic headache.

Randomized Assessment of the Safety and Efficacy of Intra-Arterial Infusion of Autologous Stem Cells in Subacute Ischemic Stroke [INTERVENTIONAL]

BACKGROUND AND PURPOSE:

Stroke is a debilitating illness for which treatment window is limited. Most patients present to the healthcare facility beyond that window. Autologous stem cells have shown some promise for this group of patients. This study was performed to evaluate the safety and the efficacy of intra-arterial infusion of bone marrow–derived mononuclear cells in patients with middle cerebral artery ischemic stroke.

MATERIALS AND METHODS:

A prospective, randomized, open-label, blinded–end point study was performed from July 2015 to June 2016. Of 229 patients with acute stroke who presented to the hospital during this period, 20 patients who satisfied the inclusion/exclusion criteria were included and randomized into the control and intervention groups. Intra-arterial stem cell infusion into the ipsilateral MCA was performed in the patients in the intervention group at 8–15 days post-stroke ictus. Final analysis at 6 months was performed for primary (safety) and secondary outcomes (efficacy).

RESULTS:

When we compared the primary end point of the study, no procedure-related mortality, complication, new infarct, or symptomatic intracranial hemorrhage was seen in the intervention group. When we compared the secondary end point of good clinical outcome, 8 (80%) patients in the intervention group showed good clinical outcome (modified Rankin Scale score < 2) with 4 (40%) patients in the control group achieving this (95% confidence interval for good outcome in patients with stem cell infusion, 49.03–94.3, and without stem cell infusion, 16.82–68.73; P = .068).

CONCLUSIONS:

Intra-arterial infusion of stem cells can be carried out safely in the subacute stage of ischemic stroke. Improved clinical outcomes were observed with intra-arterial stem cell therapy; however, studies with larger cohorts are needed to validate the results.

Endovascular Treatment of Very Large and Giant Intracranial Aneurysms: Comparison between Reconstructive and Deconstructive Techniques--A Meta-Analysis [INTERVENTIONAL]

BACKGROUND:

The safety and efficacy of reconstructive and deconstructive endovascular treatments of very large/giant intracranial aneurysms are not completely clear.

PURPOSE:

Our aim was to compare treatment-related outcomes between these 2 techniques.

DATA SOURCES:

A systematic search of 3 data bases was performed for studies published from 1990 to 2017.

STUDY SELECTION:

We selected series of reconstructive and deconstructive treatments with >10 patients.

DATA ANALYSIS:

Random-effects meta-analysis was used to analyze occlusion rates, complications, and neurologic outcomes.

DATA SYNTHESIS:

Thirty-nine studies evaluating 894 very large/giant aneurysms were included. Long-term occlusion of unruptured aneurysms was 71% and 93% after reconstructive and deconstructive treatments, respectively (P = .003). Among unruptured aneurysms, complications were lower after parent artery occlusion (16% versus 30%, P = .05), whereas among ruptured lesions, complications were lower after reconstructive techniques (34% versus 38%). Parent artery occlusion in the posterior circulation had higher complications compared with in the anterior circulation (36% versus 15%, P = .001). Overall, coiling yielded lower complication and occlusion rates compared with flow diverters and stent-assisted coiling. Complication rates of flow diversion were lower in the anterior circulation (17% versus 41%, P < .01). Among unruptured lesions, early aneurysm rupture (within 30 days) was slightly higher after reconstructive treatment (5% versus 0%, P = .08) and after flow diversion alone compared with flow diversion plus coiling (7% versus 0%).

LIMITATIONS:

Limitations were selection and publication biases.

CONCLUSIONS:

Parent artery occlusion allowed high rates of occlusion with an acceptable rate of complications for unruptured, anterior circulation aneurysms. Coiling should be preferred for posterior circulation and ruptured lesions, whereas flow diversion is relatively safe and effective for unruptured anterior circulation aneurysms.

Evaluation of the Normal Cochlear Second Interscalar Ridge Angle and Depth on 3D T2-Weighted Images: A Tool for the Diagnosis of Scala Communis and Incomplete Partition Type II [HEAD & NECK]

BACKGROUND AND PURPOSE:

Cochlear malformations may be be subtle on imaging studies. The purpose of this study was to evaluate the angle and depth of the lateral second interscalar ridge or notch in ears without sensorineural hearing loss (normal ears) and compare them with ears that have a documented incomplete type II partition malformation.

MATERIALS AND METHODS:

The second interscalar ridge notch angle and depth were measured on MR imaging in normal ears by a single experienced neuroradiologist. The images of normal and incomplete partition II malformation ears were then randomly mixed for 2 novice evaluators to measure both the second interscalar ridge notch angle and depth in a blinded manner. For the mixed group, interobserver agreement was calculated, normal and abnormal ear measurements were compared, and receiver operating characteristic curves were generated.

RESULTS:

The 94 normal ears had a mean second interscalar ridge angle of 80.86° ± 11.4° and depth of 0.54 ± 0.14 mm with the 98th percentile for an angle of 101° and a depth of 0.3 mm. In the mixed group, agreement between the 2 readers was excellent, with significant differences for angle and depth found between normal and incomplete partition type II ears for angle and depth on average (P < .001). Receiver operating characteristic cutoffs for delineating normal from abnormal ears were similar for both readers (depth, 0.31/0.34 mm; angle, 114°/104°).

CONCLUSIONS:

A measured angle of >114° and a depth of the second interscalar ridge notch of ≤0.31 mm suggest the diagnosis of incomplete partition type II malformation and scala communis. These measurements can be accurately made by novice readers.

European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study [INTERVENTIONAL]

BACKGROUND AND PURPOSE:

Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system.

MATERIALS AND METHODS:

Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated.

RESULTS:

During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13–86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1–36.6 mm), and the median neck size 4.5 mm (range, 1–30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%.

CONCLUSIONS:

This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.

The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements [SPINE]

BACKGROUND AND PURPOSE:

Hirayama disease is a benign focal amyotrophy of the distal upper limbs involving C7, C8, and T1 segmental myotomes with sparing of the brachioradialis and proximal muscles of the upper limb innervated by C5–6 myotomes. The objective of the present study was to study the utility of MR imaging in young patients presenting with weakness and wasting of the distal upper extremity and to evaluate the importance of the laminodural space during flexion cervical MR imaging.

MATERIALS AND METHODS:

This was a prospective cross-sectional study conducted from January 2014 to July 2017 in a tertiary care center from Northeast India. Forty-five patients with clinically definite Hirayama disease underwent electrophysiologic evaluation followed by MR imaging of the cervical spine.

RESULTS:

The mean age at recruitment was 22.8 ± 5.5 years. Forty patients (88.9%) had unilateral and 5 (11.1%) had bilateral upper extremity involvement. Cervical cord T2-weighted hyperintensities were demonstrated in 16 patients (35.6%), of which 15 (33.3%) had anterior horn cell hyperintensities. Flexion MR imaging showed loss of the posterior dural attachment, forward shifting of the posterior dural sac with postcontrast enhancement, and prominent posterior epidural venous plexus in all patients. The laminodural space at maximum forward shifting of the posterior dural sac ranged from 3 to 9.8 mm, with a mean distance of 5.99 mm (95% confidence interval, 5.42–6.57 mm).

CONCLUSIONS:

Flexion cervical MR imaging is a very useful investigation in diagnosing Hirayama disease. The increase in the laminodural space and the presence of cervical cord flattening during flexion are essential for diagnosis.