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Sample records for experimental functional neurosurgery

  1. Neurosurgery

    PubMed Central

    Marshall, Lawrence F.

    1988-01-01

    The Scientific Board of the California Medical Association presents the following inventory of items of progress in neurosurgery. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, research workers, or scholars to stay abreast of these items of progress in neurosurgery that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on Neurosurgery of the California Medical Association and the summaries were prepared under its direction. PMID:18750466

  2. Neurosurgery

    PubMed Central

    Giller, Cole A.; Dewey, Richard B.

    1995-01-01

    The Council on Scientific Affairs of the California Medical Association presents the following epitomes of progress in neurosurgery. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and clinical importance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of progress in medicine, whether in their own field of special interest or another. The epitomes included here were selected by the Advisory Panel to the Section on Neurosurgery of the California Medical Association, and the summaries were prepared under the direction of John H. Neal, MD, and the panel. PMID:7725709

  3. Functional neurosurgery. The modulation of neural and mind circuits.

    PubMed

    Al-Otaibi, Faisal; Al-Khairallah, Thamer

    2012-01-01

    Different complex neuroanatomical and neurochemical circuits regulate a variety of neuronal behaviors and brain functions. Any disturbance in these circuits can generate functional disorders such as movement disorders, epilepsy, pain, memory disorders, and psychiatric disorders. Functional neurosurgery aims to restore these functions, either by removing or isolating the abnormally behaving neurons or by modulating the disturbed circuits. Neuromodulation is a fast-growing field, powered by the recent advances in neuroimaging and technology. Here, we discuss recent advances and new horizons in functional neurosurgery.

  4. Experimental and clinical standards, and evolution of lasers in neurosurgery.

    PubMed

    Devaux, B C; Roux, F X

    1996-01-01

    From initial experiments of ruby, argon and CO2 lasers on the nervous system so far, dramatic progress was made in delivery systems technology as well as in knowledge of laser-tissue interaction effects and hazards through various animal experiments and clinical experience. Most surgical effects of laser light on neural tissue and the central nervous system (CNS) are thermal lesions. Haemostasis, cutting and vaporization depend on laser emission parameters--wavelength, fluence and mode--and on the exposed tissues optical and thermal properties--water and haemoglobin content, thermal conductivity and specific heat. CO2 and Nd-YAG lasers have today a large place in the neurosurgical armamentarium, while new laser sources such as high power diode lasers will have one in the near future. Current applications of these lasers derive from their respective characteristics, and include CNS tumour and vascular malformation surgery, and stereotactic neurosurgery. Intracranial, spinal cord and intra-orbital meningiomas are the best lesions for laser use for haemostasis, dissection and tissue vaporization. Resection of acoustic neuromas, pituitary tumours, spinal cord neuromas, intracerebral gliomas and metastases may also benefit from lasers as accurate, haemostatic, non-contact instruments which reduce surgical trauma to the brain and eloquent structures such as brain stem and cranial nerves. Coagulative lasers (1.06 microns and 1.32 microns Nd-YAG, argon, or diode laser) will find an application for arteriovenous malformations and cavernomas. Any fiberoptic-guided laser will find a use during stereotactic neurosurgical procedures, including image-guided resection of tumours and vascular malformations and endoscopic tumour resection and cysts or entry into a ventricle. Besides these routine applications of lasers, laser interstitial thermotherapy (LITT) and photodynamic therapy (PDT) of brain tumours are still in the experimental stage. The choice of a laser in a

  5. Functional neurosurgery for movement disorders: a historical perspective.

    PubMed

    Benabid, Alim Louis; Chabardes, Stephan; Torres, Napoleon; Piallat, Brigitte; Krack, Paul; Fraix, Valerie; Pollak, Pierre

    2009-01-01

    clear that STN stimulation is not efficient on the nondopaminergic symptoms such as freezing of gait. Based on experimental data obtained in MPTP-treated parkinsonian monkeys, the pedunculopontine nucleus has been used as a new target, and as suggested by the animal research results, its use indeed improves walking and stability when stimulation is performed at low frequency (25 Hz). The concept of simultaneous stimulation of multiple targets eventually at low or high frequency, and that of several electrodes in one target, is being accepted to increase the efficiency. This leads to and is being facilitated by the development of new hardware (multiple-channel IPGs, specific electrodes, rechargeable batteries). Still additional efforts are needed at the level of the stimulation paradigm and in the waveform. The recent development of nanotechnologies allows the design of totally new systems expanding the field of deep brain stimulation. These new techniques will make it possible to not only inhibit or excite deep brain structures to alleviate abnormal symptoms but also open the field for the use of recording cortical activities to drive neuroprostheses through brain-computer interfaces. The new field of compensation of deficits will then become part of the field of functional neurosurgery.

  6. Pediatric Epilepsy: Neurology, Functional Imaging, and Neurosurgery.

    PubMed

    Mountz, James M; Patterson, Christina M; Tamber, Mandeep S

    2017-03-01

    In this chapter we provide a comprehensive review of the current role that functional imaging can have in the care of the pediatric epilepsy patient from the perspective of the epilepsy neurologist and the epilepsy neurosurgeon. In the neurology section, the diagnosis and classification of epilepsy adapted by the International League Against Epilepsy as well as the etiology and incidence of the disease is presented. The neuroimaging section describes how advanced nuclear medicine imaging methods can be synergized to provide a maximum opportunity to localize an epileptogenic focus. This section described the value of FDG-PET and regional cerebral blood flow SPECT in the identification of an epileptogenic focus. The imaging section also emphasizes the importance on developing a dedicated epilepsy management team, comprised of an epilepsy imaging specialist, epilepsy neurologist and epilepsy neurosurgeon, to provide the maximum benefit to each child with epilepsy. An emphasis is placed on preparation for ictal SPECT injection procedures, including the critical role of an automated injector well as the use of state-of-the-art dedicated nuclear medicine imaging and analysis protocols to correctly localize the epileptogenic focus location. In the final section, surgical options, approaches and expected outcomes for the different classes of epilepsy is presented.

  7. Experimental new automatic tools for robotic stereotactic neurosurgery: towards "no hands" procedure of leads implantation into a brain target.

    PubMed

    Mazzone, P; Arena, P; Cantelli, L; Spampinato, G; Sposato, S; Cozzolino, S; Demarinis, P; Muscato, G

    2016-07-01

    The use of robotics in neurosurgery and, particularly, in stereotactic neurosurgery, is becoming more and more adopted because of the great advantages that it offers. Robotic manipulators easily allow to achieve great precision, reliability, and rapidity in the positioning of surgical instruments or devices in the brain. The aim of this work was to experimentally verify a fully automatic "no hands" surgical procedure. The integration of neuroimaging to data for planning the surgery, followed by application of new specific surgical tools, permitted the realization of a fully automated robotic implantation of leads in brain targets. An anthropomorphic commercial manipulator was utilized. In a preliminary phase, a software to plan surgery was developed, and the surgical tools were tested first during a simulation and then on a skull mock-up. In such a way, several tools were developed and tested, and the basis for an innovative surgical procedure arose. The final experimentation was carried out on anesthetized "large white" pigs. The determination of stereotactic parameters for the correct planning to reach the intended target was performed with the same technique currently employed in human stereotactic neurosurgery, and the robotic system revealed to be reliable and precise in reaching the target. The results of this work strengthen the possibility that a neurosurgeon may be substituted by a machine, and may represent the beginning of a new approach in the current clinical practice. Moreover, this possibility may have a great impact not only on stereotactic functional procedures but also on the entire domain of neurosurgery.

  8. What Have We Learned About Movement Disorders from Functional Neurosurgery?

    PubMed

    Lozano, Andres M; Hutchison, William D; Kalia, Suneil K

    2017-07-25

    Modern functional neurosurgery for movement disorders such as Parkinson's disease, tremor, and dystonia involves the placement of focal lesions or the application of deep brain stimulation (DBS) within circuits that modulate motor function. Precise targeting of these motor structures can be further refined by the use of electrophysiological approaches. In particular, microelectrode recordings enable the delineation of neuroanatomic structures. In the course of these operations, there is an opportunity not only to map basal ganglia structures but also to gain insights into how disturbances in neural activity produce movement disorders. In this review, we aim to highlight what the field has uncovered thus far about movement disorders through DBS. The work to date lays the foundation for future studies that will shed further light on dysfunctional circuits mediating diseases of the nervous system and how we might modulate these circuits therapeutically.

  9. [Computerized atlas for image-guided stereotactic functional neurosurgery].

    PubMed

    Carballo-Barreda, M; RodríGuez-Rojas, R; Torres-Montoya, A; LóPez-Flores, G

    2007-12-01

    A computerized version of the Schaltenbrand and Wahren's stereotactic brain atlas for image-guided functional neurosurgery planning has been developed and integrated into our PC-based planning system. The SW atlas plates were digitized, contoured and labeled for both hemispheres. The computerized atlas may be interactively registered with patient's data using linear and non-linear transformation. The implemented computational tools and applications are presented. Our computer system permits navigation through original or reconstructed slices, multiple-views synchronization and zoom to improve the localization of the commisures and the surgical targets, likewise the optimum path selection. Atlas position in the target's region can be interactively actualized and lesion's position and volume may be simulated. Its benefits of this approach include increased accuracy of target definition, decreased the number of electrode tracts and for instance the time of the surgery, and reduced surgical complications.

  10. Numerical simulations of clinical focused ultrasound functional neurosurgery

    PubMed Central

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-01-01

    A computational model utilizing grid and finite difference methods was developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13 % lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13 % smaller in the anterior–posterior direction and 22 ± 14% smaller in the inferior–superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  11. Numerical simulations of clinical focused ultrasound functional neurosurgery

    NASA Astrophysics Data System (ADS)

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  12. Some recent trends and further promising directions in functional neurosurgery.

    PubMed

    Tierney, Travis S; Sankar, Tejas; Lozano, Andres M

    2013-01-01

    The field of functional neurosurgery has developed a number of recent innovative neuromodulatory approaches to treat disease that remains resistant to the best medical therapy. These include novel surgical techniques to intervene in motor and cognitive sequelae of refractory epilepsy, neurodegenerative disease, and certain psychiatric conditions. To a large extent, much of the innovation in our field continues to be driven by a systems-level understanding of the impact of disease on the brain. For example, several groups have exploited findings from neuroimaging work to identify a number of new potential neuromodulatory targets for the treatment of refractory depression. Ongoing discoveries at the cellular and molecular level promise targeted gene or drug delivery aimed at curing disease. Neurosurgeons will certainly remain at the forefront of translating these strategies into practical clinical applications. Several randomized trials are now underway to assess the safety and efficacy of a number of new approaches, and we will continue to acquire better knowledge of optimal patient selection, identification of the most effective neuromodulatory targets, and recognition of adverse effects as these studies progress.

  13. Trends and importance of radiosurgery for the development of functional neurosurgery

    PubMed Central

    Kondziolka, Douglas; Flickinger, John C.; Niranjan, Ajay; Lunsford, L. Dade

    2012-01-01

    Functional neurosurgery includes surgery conducted to ablate, augment, or modulate targets that lead to improvement in neurological function or behavior. Surgical approaches for this purpose include destructive lesioning with different mechanical or biologic agents or energy sources, non-destructive electrical modulation, and cellular or chemical augmentation. Our purpose was to review the role of stereotactic radiosurgery used for functional indications and to discuss future applications and potential techniques. Imaging and neurophysiological research will enable surgeons to consider new targets and circuits that may be clinically important. Radiosurgery is one minimal access approach to those targets. PMID:22826808

  14. Functional connectivity networks for preoperative brain mapping in neurosurgery.

    PubMed

    Hart, Michael G; Price, Stephen J; Suckling, John

    2016-08-26

    OBJECTIVE Resection of focal brain lesions involves maximizing the resection while preserving brain function. Mapping brain function has entered a new era focusing on distributed connectivity networks at "rest," that is, in the absence of a specific task or stimulus, requiring minimal participant engagement. Central to this frame shift has been the development of methods for the rapid assessment of whole-brain connectivity with functional MRI (fMRI) involving blood oxygenation level-dependent imaging. The authors appraised the feasibility of fMRI-based mapping of a repertoire of functional connectivity networks in neurosurgical patients with focal lesions and the potential benefits of resting-state connectivity mapping for surgical planning. METHODS Resting-state fMRI sequences with a 3-T scanner and multiecho echo-planar imaging coupled to independent component analysis were acquired preoperatively from 5 study participants who had a right temporoparietooccipital glioblastoma. Seed-based functional connectivity analysis was performed with InstaCorr. Network identification focused on 7 major functional connectivity networks described in the literature and a putative language network centered on Broca's area. RESULTS All 8 functional connectivity networks were identified in each participant. Tumor-related topological changes to the default mode network were observed in all participants. In addition, each participant had at least 1 other abnormal network, and each network was abnormal in at least 1 participant. Individual patterns of network irregularities were identified with a qualitative approach and included local displacement due to mass effect, loss of a functional network component, and recruitment of new regions. CONCLUSIONS Resting-state fMRI can reliably and rapidly detect common functional connectivity networks in patients with glioblastoma and also has sufficient sensitivity for identifying patterns of network alterations. Mapping of functional

  15. From Structure to Circuits: The Contribution of MEG Connectivity Studies to Functional Neurosurgery

    PubMed Central

    Pang, Elizabeth W.; Snead III, O. C.

    2016-01-01

    New advances in structural neuroimaging have revealed the intricate and extensive connections within the brain, data which have informed a number of ambitious projects such as the mapping of the human connectome. Elucidation of the structural connections of the brain, at both the macro and micro levels, promises new perspectives on brain structure and function that could translate into improved outcomes in functional neurosurgery. The understanding of neuronal structural connectivity afforded by these data now offers a vista on the brain, in both healthy and diseased states, that could not be seen with traditional neuroimaging. Concurrent with these developments in structural imaging, a complementary modality called magnetoencephalography (MEG) has been garnering great attention because it too holds promise for being able to shed light on the intricacies of functional brain connectivity. MEG is based upon the elemental principle of physics that an electrical current generates a magnetic field. Hence, MEG uses highly sensitive biomagnetometers to measure extracranial magnetic fields produced by intracellular neuronal currents. Put simply then, MEG is a measure of neurophysiological activity, which captures the magnetic fields generated by synchronized intraneuronal electrical activity. As such, MEG recordings offer exquisite resolution in the time and oscillatory domain and, as well, when co-registered with magnetic resonance imaging (MRI), offer excellent resolution in the spatial domain. Recent advances in MEG computational and graph theoretical methods have led to studies of connectivity in the time-frequency domain. As such, MEG can elucidate a neurophysiological-based functional circuitry that may enhance what is seen with MRI connectivity studies. In particular, MEG may offer additional insight not possible by MRI when used to study complex eloquent function, where the precise timing and coordination of brain areas is critical. This article will review the

  16. [Magnetoencephalography: a method for the study of brain function in neurosurgery].

    PubMed

    Braun, Christoph

    2007-01-01

    Magnetoencephalography (MEG) is a non-invasive method for the study of electro-magnetic brain activity. Using multi-channel recordings the topography of the magnetic field can be recorded above the scalp with a temporal resolution of less than one millisecond. The method is suitable for the description and localization of cortical brain functions. The magnetic field strength that can be measured at up to 300 sensors is in the range of a few femto Tesla (10(-15) T) to somepico Tesla (10(-12) T). In order to measure these low magnetic fields highly sensitive SQUID-detectors are used on the one hand. On the other hand appropriate shielding equipment is employed to reduce effects of noise. Besides brain responses evoked by internal and external events (event-related magnetic fields), state-dependant oscillatory brain activity MEG can be recorded (spontaneous activity). Slow cortical oscillations in the range of 1 to 4 Hz are generated by damage of brain tissue and in the surrounding of brain tumors. In neurosurgery these activities can be used to monitor therapeutic success. Furthermore, oscillatory activities provide information about cortical regions involved in motor control. The measurement of motor related activities allows for the identification of recovery processes and reorganization after brain injury. Event-related magnetic brain responses are used in pre-surgical diagnosis and planning of treatment in epilepsy. In addition, they can be utilized to assess alterations in the functional organization of the cortex following injuries, tumor growth and neurosurgical interventions.

  17. Actualities and Perspectives in Neurosurgery

    PubMed Central

    Iencean, SM; Brehar, FM

    2008-01-01

    In the field of neurosurgery, like in other surgical specialties, the last decades have brought major achievements. The series of revolutionary discoveries has started during the last century in the fifties, with stereotactic radiosurgery, then continued with the implementation of operative microscope (during the seventies), the endovascular embolisation in the nineties and finally with the major improvement in robotic neurosurgery and molecular neurosurgery at the beginning of this century. The major innovation has been brought not only in the field of therapeutical measures but also in the field of neuro– imaging. Thus, the modern MRI with more than 3 Tesla, can reveal to the neurosurgeon the most intimate structures of the nervous system. Several important areas in neurosurgery like: vascular neurosurgery, functional neurosurgery and brain tumors pathology, benefit from the modern technology and from the latest discoveries from genetic and molecular biology. In conclusion, summarizing the discoveries of the last decade, we emphasize that the related areas like genetics, molecular biology, computer technology become more and more important in the future progress of the neurosurgery. PMID:20108475

  18. A fantastic voyage: a personal perspective on involvement in the development of modern stereotactic and functional neurosurgery (1974-2004).

    PubMed

    Apuzzo, Michael L J

    2005-05-01

    Stressing environments, individuals, ideas, and global events, this historical stereotactic and functional neurosurgical vignette initially presents a review of factors in the genesis of personal interest and the foundations of involvement in the discipline of neurological surgery. The vignette then traces the development of concepts and instrumentation and their ultimate practical utilization in patient care on the neurosurgical services at the Keck School of Medicine at the University of Southern California over the course of a 3-decade period (1974-2004). The article summarizes and elaborates details of contributions to the literature and complex involvement on the national and international levels as the refinements and capabilities of stereotactic and functional neurosurgery have been reinvented over a generation through the emergence of new technology, ideas, individual ingenuity, and active collegial exchange.

  19. Computer-assisted neurosurgery.

    PubMed

    Maciunas, Robert J

    2006-01-01

    Computer-assisted neurosurgery has become so successful that it is rapidly becoming indistinguishable from, quite simply, neurosurgery. This trend promises to accelerate over the next several decades, bringing considerable benefit to the patients we care for. From a pragmatic point of view, can we identify specific instances in which clinical practice has been altered by computer assistance? During craniotomies for the resection of brain tumors, this technology has led to a greater standardization within and among practitioners for the expected degree of resection and the risk of morbidity and mortality. Minimally invasive approaches are transforming the practice of cranial base surgery. This technological trend has made craniotomy for biopsy virtually obsolete in the face of frameless stereotactic techniques. Functional neurosurgery has benefited from these technologies, as deep brain stimulation surgery has become the standard of care for most cases of movement disorder surgery. Extratemporal epilepsy due to cortical dysplasia has proven especially amenable to image-guided surgical techniques that integrate electrophysiological monitoring to refine the target of resection. New surgical procedures made possible by computer assistance include minimally invasive spine surgery, endovascular procedures, resections of low-grade nonenhancing gliomas, and stereotactic radiosurgery. A program for future research and development in this field would include: Electronic patient medical records. Automatic dynamic and elastic registration Novel surgical instrumentation guided by augmented reality Real-time feedback using anatomic and functional information Active robotic servo control systems to amplify neurosurgical capabilities Outcomes analysis-driven refinement of neurosurgical interventions. It is apparent that using computer assistance in neurosurgery has begun a process that will irrevocably transform all of neurosurgical practice itself. It must be neurosurgeons

  20. Photolasertherapy for the treatment of infections in neurosurgery: experimental and clinical study

    NASA Astrophysics Data System (ADS)

    Lombard, Gian F.

    1996-12-01

    At the first time, the CO2 laser was utilised in infective neurosurgical pathology as a surgical cutting instrument to remove inflammatory pseudomembranes in chronic osteomyelitis, and as a vaporising instmment on the dura mater surface. Successively, the instrument, defocused and at a low power, was used for prolonged and diffuse photo coagulation ofthe surgical cavity, particularly, ofthe dural surface and ofthe osteomyelitic bone edges, with the aim to sterilise tissues. So, we saw a shortening of the average time of wound healing and a lack of recurrence of the septic pathology. Then, we have treated, with CO2 laser, intracranial infective pathology: i.e. primary abscesses, capsulated or not, circumscribed purulent encephalitis, secondary abscesses in surgical cavities (patients operated for intracranial hematomas and tumors). In these cases we have obtained a lack of septic recurrences and an improvement ofneurological post-operative course. Thank to these results, we have continued to use laser in infective pathology; for giving an experimental support to these results we have carried on researches in vivo (on the experimental animal) to see the interaction between the laser and inflammatory tissue, and in vitro (on bacterial culture: in solid and liquid media) to see the laser effect on the bacterial cell. The bacterial cell has been also sensibiized to the photo dynamic effect of the laser (Argon, He-Ne), with hematoporphyrin. The goal of these experiments is to understand the role of thermal, photochemical, and mechanic resonance laser effects in the interaction between laser radiation and bacterial cell.

  1. Water jet dissection in neurosurgery: experimental results in the porcine cadaveric brain.

    PubMed

    Oertel, Joachim; Gaab, Michael Robert; Knapp, Andreas; Essig, Harald; Warzok, Rolf; Piek, Juergen

    2003-01-01

    Water jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing. In this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80-150 in microm diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1-40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically. The best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-microm Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure. The results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet's characteristics may make this device a useful addition to the neurosurgical armamentarium.

  2. Discovering neurosurgery: new frontiers.

    PubMed

    Rutka, James T

    2011-12-01

    Over the centuries, discoveries of lands unknown, treasures lost and buried, and formulas to delineate physicochemical processes have led to advancements in our understanding of how the world is structured and governed. In science and medicine, discoveries are frequently made following deliberate periods of observation and experimentation to test hypotheses. However, in some instances, discoveries may arise either following a "eureka moment" that transcends rigorous scientific experimentation or following a serendipitous observation. In many instances, scientific discoveries will lead to new inventions that are aimed at improving the manner in which tasks or operations are performed. In this address, some of the key discoveries in science and medicine that have impacted significantly on the field of neurosurgery are described. Some of these include discoveries in neuroanatomy, anesthesiology, infectious diseases, antisepsis, and radiology. Discoveries in the field of molecular science, from the discovery of DNA to next-generation DNA sequencing, which have helped improve the diagnosis and prognosis of neurosurgical patients with conditions such as brain tumors, are also described. In the end, these discoveries have led us to new frontiers in the subspecialty practice of neurosurgery. Navigating our way through these new frontiers will undoubtedly lead to additional discoveries that are unimaginable at present but bound to improve the future care of neurosurgical patients.

  3. Functional Neurosurgery in the Human Thalamus by Transcranial Magnetic Resonance Guided Focused Ultrasound

    NASA Astrophysics Data System (ADS)

    Werner, Beat; Morel, Anne; Jeanmonod, Daniel; Martin, Ernst

    2009-04-01

    Potential applications of Transcranial Magnetic Resonance guided Focused Ultrasound (TcMRgFUS) include treatment of functional brain disorders, such as Parkinson's disease, dystonia and tremor, neurogenic pain and tinnitus, neuropsychiatric disorders and epilepsy. In this study we demonstrate the feasibility of non-invasive TcMRgFUS ablation of clinically well established targets in the human thalamus that are currently accessed stereotactically by interventional strategies based on the concept of the thalamocortical dysrhythmia (TCD). Thermal hotspots suitable for clinical intervention were created successfully in anatomical preparations of human ex-vivo heads under pseudo clinical conditions. The hotspots could be positioned at the target locations as needed and local energy deposition was sufficient to create tissue ablation. Numerical simulations based on these experimental data predict that the acoustic energy needed to create ablative lesions in-vivo will be within limits that can safely applied.

  4. [Deep brain recording and length of surgery in stereotactic and functional neurosurgery for movement disorders].

    PubMed

    Teijeiro, Juan; Macías, Raúl J; Maragoto, Carlos; García, Iván; Alvarez, Mario; Quintanal, Nelson E

    2014-01-01

    Our objectives were to study the length of multi-unit recordings (MURs) of brain activity in 20 years of movement disorder neurosurgeries and to determine the number of times in which it was necessary for the teams using single-unit recording (SUR) to explore all the electrode tracks in the simultaneously recorded sites (SRS). This was a retrospective descriptive statistical analysis of MUR length on 4,296 tracks in 952 surgeries. The exclusion criteria were: tracks with fewer than 5 recorded signals, tracks that had a signal length different from the habitual 2s, or there being unusual situations not related to the MUR, as well as the first 20 surgeries of each surgical target. This yielded a total of 3,448 tracks in 805 surgeries. We also determined the number of the total 952 surgeries in which all the tracks in the SURs of the SRS were explored. The mean and its confidence interval (P=.05) of time per MUR track were 5.49±0.16min in subthalamic nucleus surgery, 8.82±0.24min in the medial or internal globus pallidus) and 18.51±1.31min in the ventral intermediate nucleus of the thalamus. For the total sum of tracks per surgery, in 75% of cases the total time was less than 39min in subthalamic nucleus, almost 42min in the medial or internal globus pallidus and less than 1h and 17min in ventral intermediate nucleus of the thalamus. All the tracks in the SUR SRS were explored in only 4.2% of the surgeries. The impact of MUR on surgical time is acceptable for this guide in objective localization for surgical targets, without having to use several simultaneous electrodes (not all indispensable in most of the cases). Consequently, there is less risk for the patient. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  5. [Automatic anatomic-physiologic correspondence of deep structures of the central nervous system in stereotaxic functional neurosurgery].

    PubMed

    Teijeiro Amador, J; Macías González, R J; Ohye, C; Muñoz Aguilar, J L; Alvarez González, L M; Ochoa Zaldívar, L; Soler Alayón, W; Antelo, J M; Guerra Figueredo, E; López Flores, G

    1996-11-01

    This work describes in detail the graphic facilities of a neurosurgical deep recording system for the anatomic-physiologic analysis of central nervous system deep structures in stereotaxic function neurosurgery guided by deep semi-microrecordings of the brain, as developed by the International Center of Neurologic Restoration in Cuba. This system for digitization of electrical activity in the brain uses an IBM-compatible 80386/80486 microprocessor in place of analog equipment for the visualization and recording of signals, thereby providing easier manipulation of recorded data and greater flexibility of analysis. The system automatically integrates each pulse recorded and quantifies its average amplitude. For each brain region explored, the behavior of the integrated activity recorded can be displayed on the corresponding sagittal view from the cerebral atlas of Schaltenbrand-Wahren, and then automatically scaled to the anatomic dimensions of each patient. The picture, with its different options, Facilitates analysis of anatomic correspondence of deep electrophysiologic signals so the various structures, nuclei and specific neuronal groups can be precisely located in the patient's brain. To date the system has been used successfully in over 110 neurosurgical procedures ventral intermedios (vim)-thalamotomy, pallidotomy, subthalotomy and neurotransplantation, providing more certain location of lesions or grafting sites for managing symptoms in Parkinson's disease and other movement disorders.

  6. Laser applications in neurosurgery

    NASA Astrophysics Data System (ADS)

    Cerullo, Leonard J.

    1985-09-01

    The "false start" of the laser in neurosurgery should not be misconstrued as a denial of the inherent advantages of precision and gentleness in dealing with neural tissue. Rather, early investigators were frustrated by unrealistic expectations, cumbersome equipment, and a general ignorance of microtechnique. By the early 70s, microneurosurgery was well established, surgical laser equipment for free hand and microlinked application had been developed, and a more realistic view of the limitations of the laser had been established. Consequently, the late 70s really heralded the renaissance of the laser in neurosurgery. Since then, there has been an overwhelming acceptance of the tool in a variety of clinical situations, broadly categorized in five groups. 1)|Perhaps the most generally accepted area is in the removal of extra-axial tumors of the brain and spinal cord. These tumors, benign by histology but treacherous by location, do not present until a significant amount of neurological compensation has already occurred. The application of additional trauma to the neural tissue, whether by further tumor growth or surgical manipulation, frequently results in irreversible damage. Here, the ability of the laser to vaporize tissue, in a fairly hemostatic fashion, without mechanical or thermal damage to sensitive surrounding tissues, is essential. 2)|The ability to incise delicate neural tissue with minimal spread of thermal destruction to adjacent functioning tissue makes the laser the ideal instrument when tumors deep under the surface are encountered in the brain or spinal cord. Thus, the second group of applications is in the transgression of normal neural structures to arrive at deeper pathological tissue. 3)|The third area of benefit for the laser in neurosurgery has been in the performance of neuroablative procedures, calling for deliberate destruction of functioning neural tissue in a controlled fashion. Again, the precision and shape confinement of the destructive

  7. History of Korean Neurosurgery.

    PubMed

    Hwang, Sung-nam

    2015-08-01

    The year 2012 was the 50th anniversary of the Korean Neurosurgical Society, and in 2013, the 15th World Congress of Neurosurgery took place in Seoul, Korea. Thus, it is an appropriate occasion to introduce the world to the history of the Korean Neurosurgical Society and the foundation, development, and growth of Korean neurosurgery. Historical materials and pictures were collected and reviewed from the history book and photo albums of the Korean Neurosurgical Society. During the last 50 years, the Korean Neurosurgical Society and Korean neurosurgery have developed and grown enormously not only in quantity but also in quality. In every aspect, the turning point from the old to the new era of the Korean Neurosurgical Society and Korean neurosurgery was the year 1980. Copyright © 2015. Published by Elsevier Inc.

  8. Computers and neurosurgery.

    PubMed

    Shaikhouni, Ammar; Elder, J Bradley

    2012-11-01

    At the turn of the twentieth century, the only computational device used in neurosurgical procedures was the brain of the surgeon. Today, most neurosurgical procedures rely at least in part on the use of a computer to help perform surgeries accurately and safely. The techniques that revolutionized neurosurgery were mostly developed after the 1950s. Just before that era, the transistor was invented in the late 1940s, and the integrated circuit was invented in the late 1950s. During this time, the first automated, programmable computational machines were introduced. The rapid progress in the field of neurosurgery not only occurred hand in hand with the development of modern computers, but one also can state that modern neurosurgery would not exist without computers. The focus of this article is the impact modern computers have had on the practice of neurosurgery. Neuroimaging, neuronavigation, and neuromodulation are examples of tools in the armamentarium of the modern neurosurgeon that owe each step in their evolution to progress made in computer technology. Advances in computer technology central to innovations in these fields are highlighted, with particular attention to neuroimaging. Developments over the last 10 years in areas of sensors and robotics that promise to transform the practice of neurosurgery further are discussed. Potential impacts of advances in computers related to neurosurgery in developing countries and underserved regions are also discussed. As this article illustrates, the computer, with its underlying and related technologies, is central to advances in neurosurgery over the last half century. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Endovascular Neurosurgery: Personal Experience and Future Perspectives.

    PubMed

    Raymond, Jean

    2016-09-01

    From Luessenhop's early clinical experience until the present day, experimental methods have been introduced to make progress in endovascular neurosurgery. A personal historical narrative, spanning the 1980s to 2010s, with a review of past opportunities, current problems, and future perspectives. Although the technology has significantly improved, our clinical culture remains a barrier to methodologically sound and safe innovative care and progress. We must learn how to safely practice endovascular neurosurgery in the presence of uncertainty and verify patient outcomes in real time. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. [Neurosurgery in the elderly patient: Geriatric neurosurgery].

    PubMed

    González-Bonet, Luis Germán; Tarazona-Santabalbina, Francisco-José; Lizán Tudela, Luis

    2016-01-01

    Between 2000 and 2050, the proportion of the world's population over 60 years will double, and the number of people aged 80 and older will quadruple. Health professional training does not include instructions about specific care for older people. The World Health Organization maintains that all health providers should be trained on ageing issues. Thus, it is proposed to analyse the effect of ageing on Neurosurgery in our country. A retrospective historical cohort study was performed on individuals age 70 years or older admitted to the Neurosurgery or the Intensive Care Unit of our hospital, with neurosurgical disease, between two periods: 1999-2000 and 2010-2011. An analysis was made on variables such as: age, pathology, length of stay, comorbidity, performance status, re-admissions and mortality. Similar numbers of patients were admitted during the two periods: 409 and 413. However, there was an increase of 77.5% in patients older than 70 years: 80 versus 142. Statistically significant differences were observed in the Charlson Comorbidity Index, the admission Glasgow Coma Scale (GCS) score, length of stay, and re-admissions. Comorbidity and admission GCS score were particularly worse in the second period. Nevertheless, the mean length of stay was lower in that period, but showing more hospital re-admissions. After multivariate analysis, it was observed that re-admissions were associated with comorbidity, but not with early hospital discharge. No differences were found in performance status or mortality. A very considerable increase in percentage of patients older than 70 years old was found. There were no differences in performance status or mortality, which was probably due to the multidisciplinary management of these patients. The results of this study support the development of an interdisciplinary work group dedicated to Geriatric Neurosurgery. Copyright © 2015 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  11. Feasibility of Diffusion Tractography for the Reconstruction of Intra-Thalamic and Cerebello-Thalamic Targets for Functional Neurosurgery: A Multi-Vendor Pilot Study in Four Subjects

    PubMed Central

    Jakab, András; Werner, Beat; Piccirelli, Marco; Kovács, Kázmér; Martin, Ernst; Thornton, John S.; Yousry, Tarek; Szekely, Gabor; O‘Gorman Tuura, Ruth

    2016-01-01

    Functional stereotactic neurosurgery by means of deep brain stimulation or ablation provides an effective treatment for movement disorders, but the outcome of surgical interventions depends on the accuracy by which the target structures are reached. The purpose of this pilot study was to evaluate the feasibility of diffusion tensor imaging (DTI) based probabilistic tractography of deep brain structures that are commonly used for pre- and perioperative targeting for functional neurosurgery. Three targets were reconstructed based on their significance as intervention sites or as a no-go area to avoid adverse side effects: the connections propagating from the thalamus to (1) primary and supplementary motor areas, (2) to somatosensory areas and the cerebello-thalamic tract (CTT). We evaluated the overlap of the reconstructed connectivity based targets with corresponding atlas based data, and tested the inter-subject and inter-scanner variability by acquiring repeated DTI from four volunteers, and on three MRI scanners with similar sequence parameters. Compared to a 3D histological atlas of the human thalamus, moderate overlaps of 35-50% were measured between connectivity- and atlas based volumes, while the minimal distance between the centerpoints of atlas and connectivity targets was 2.5 mm. The variability caused by the MRI scanner was similar to the inter-subject variability, except for connections with the postcentral gyrus where it was higher. While CTT resolved the anatomically correct trajectory of the tract individually, high volumetric variability was found across subjects and between scanners. DTI can be applied in the clinical, preoperative setting to reconstruct the CTT and to localize subdivisions within the lateral thalamus. In our pilot study, such subdivisions moderately matched the borders of the ventrolateral-posteroventral (VLpv) nucleus and the ventral-posterolateral (VPL) nucleus. Limitations of the currently used standard DTI protocols were

  12. Nanotechnology and vascular neurosurgery: an in vivo experimental study on microvessels repair using laser photoactivation of a nanostructured hyaluronan solder.

    PubMed

    Esposito, G; Rossi, F; Matteini, P; Ratto, F; Sabatino, G; Puca, A; Albanese, A; Rossi, G; Marchese, E; Maira, G; Pini, R

    2012-01-01

    Sealing tissues by laser in neurosurgical procedures may overcome problems related to the use of conventional suturing methods which can be associated with various degrees of vascular wall damage. Despite the significant experimental and clinical achievements of the past, a standardized clinical application of laser-welding technology has not yet been implemented. The main problem is related to the use of common organic chromophores. A substantial breakthrough in the laser welding of biological tissues may come from the advent of nanotechnologies. In this paper we describe an experimental study, to confirm the feasibility of an innovative laser-assisted vascular repair (LAVR) technique based on diode laser irradiation and subsequent photoactivation of a hyaluronan solder embedded with near infrared (NIR) absorbing gold nanorods (GNRs), and to analyze the induced closuring effect in a follow-up study performed in animal model. Twenty New Zealand rabbits underwent closure of a 3-mm longitudinal incision performed on the common carotid artery (CCA) by means of 810 nm diode laser irradiation, in conjunction with the topical application of an optimized GNR composite. Effective closure of the arterial wound was accomplished by using very low laser intensity (30 W/cm2). The average CCA occlusion time was as low as 50 sec. Animals underwent different follow-up periods (2, 8, 30 days). After follow-up, they were re-anesthetized, the patency of the treated vessels was tested (Doppler analysis) and then the irradiated vessels were excised and subjected to histological evaluations. Morphological examinations of the samples documented the integrity of the vascular wall. No host reaction to nanoparticles occurred. Collagen and elastic fibers returned to their normal architecture 30 days after treatment. A Scanning Electron Microscopy (SEM) examination and immuno-histochemical analysis demonstrated a full re-endothelization of the vessel walls. We thus confirmed that a laser

  13. Pediatric neurosurgery: pride and prejudice.

    PubMed

    Winston, K R

    2000-02-01

    Pediatric neurosurgery now exists as a member of the family of neurosurgery with its own training programs, process of accreditation, national and international conferences and scientific journals. The relentless expansion of science relevant to the practice of neurosurgery and the changing patterns of neurosurgical practice have driven and continue to drive the juggernaut of evolutionary process which sometimes necessitates the birth of new specialties of practice. The history and the development of neurosurgery as they relate to children are presented. There is no more reason to think that the established specialty of pediatric neurosurgery or the patients under the care of pediatric neurosurgeons would benefit from the collapsing of pediatric neurosurgery back into the general neurosurgical fold than to think that all of neurosurgery, and hence all patients cared for by neurosurgeons, would benefit from the return of organized neurosurgery to its general surgical parent. Just as mankind benefits from the steady advancement of all aspects of neurosurgery, children benefit from the existence and steady advancement of pediatric neurosurgery.

  14. Evidence-based neurosurgery

    PubMed Central

    Esene, Ignatius N.; Baeesa, Saleh S.; Ammar, Ahmed

    2016-01-01

    Medical evidence is obtainable from approaches, which might be descriptive, analytic and integrative and ranked into levels of evidence, graded according to quality and summarized into strengths of recommendation. Sources of evidence range from expert opinions through well-randomized control trials to meta-analyses. The conscientious, explicit, and judicious use of current best evidence in making decisions related to the care of individual patients defines the concept of evidence-based neurosurgery (EBN). We reviewed reference books of clinical epidemiology, evidence-based practice and other previously related articles addressing principles of evidence-based practice in neurosurgery. Based on existing theories and models and our cumulative years of experience and expertise conducting research and promoting EBN, we have synthesized and presented a holistic overview of the concept of EBN. We have also underscored the importance of clinical research and its relationship to EBN. Useful electronic resources are provided. The concept of critical appraisal is introduced. PMID:27356649

  15. Lasers in neurosurgery.

    PubMed

    Krishnamurthy, S; Powers, S K

    1994-01-01

    Lasers have been used in neurosurgery for the past 25 years, undergoing modifications to suit the specific needs of this medical discipline. The present report reviews the current use of lasers in neurosurgical practice and examines the pros and cons of lasers in specific neurosurgical applications. In spite of their advantages, laser use is still not widespread in neurosurgery. One reason is the continued lack of complete control over real-time laser interactions with neural tissue. A greater acceptance and use of lasers by neurosurgeons will depend upon automated control over defined specific parameters for laser applications based upon the type of tissue, the desired effect on tissue, and application to the clinical situation without loss of precision and a lot of expense. This will require the integration of newer lasers, computers, robotics, stereotaxy, and concepts of minimally invasive surgery into the routine management of neurosurgical problems.

  16. Simulating tumour removal in neurosurgery.

    PubMed

    Radetzky, A; Rudolph, M

    2001-12-01

    In this article the software system ROBO-SIM is described. ROBO-SIM is a planning and simulation tool for minimally invasive neurosurgery. Different to the most other simulation tools, ROBO-SIM is able to use actual patient's datasets for simulation. Same as in real neurosurgery a planning step, which provides more functionality as up-to-date planning systems on the market, is performed before undergoing the simulated operation. The planning steps include the definition of the trepanation point for entry into the skull and the target point within the depth of the brain, checking the surgical track and doing virtual trepanations (virtual craniotomy). For use with an intra-operative active manipulator, which is guided by the surgeon during real surgery (robotic surgery), go- and non-go-areas can be defined. During operation, the robot restricts the surgeon from leaving these go-areas. After planning, an additional simulation system, which is understood as an extension to the planning step, is used to simulate whole surgical interventions directly on the patient's anatomy basing on the planning data and by using the same instruments as for the real intervention. First tests with ROBO-SIM are performed on a phantom developed for this purpose and on actual patient's datasets with ventricular tumours.

  17. NASA Robotic Neurosurgery Testbed

    NASA Technical Reports Server (NTRS)

    Mah, Robert

    1997-01-01

    The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations. In neurosurgery, the needle used in the standard stereotactic CT (Computational Tomography) or MRI (Magnetic Resonance Imaging) guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled 'Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification' is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

  18. NASA Robotic Neurosurgery Testbed

    NASA Technical Reports Server (NTRS)

    Mah, Robert

    1997-01-01

    The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations, In neurosurgery, the needle used in the standard stereotactic CT or MRI guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled "Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification" is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

  19. Robotics in neurosurgery.

    PubMed

    McBeth, Paul B; Louw, Deon F; Rizun, Peter R; Sutherland, Garnette R

    2004-10-01

    Technological developments in imaging guidance, intraoperative imaging, and microscopy have pushed neurosurgeons to the limits of their dexterity and stamina. The introduction of robotically assisted surgery has provided surgeons with improved ergonomics and enhanced visualization, dexterity, and haptic capabilities. This article provides a historical perspective on neurosurgical robots, including image-guided stereotactic and microsurgery systems. The future of robot-assisted neurosurgery, including the use of surgical simulation tools and methods to evaluate surgeon performance, is discussed.

  20. NASA Robotic Neurosurgery Testbed

    NASA Technical Reports Server (NTRS)

    Mah, Robert

    1997-01-01

    The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations. In neurosurgery, the needle used in the standard stereotactic CT (Computational Tomography) or MRI (Magnetic Resonance Imaging) guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled 'Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification' is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

  1. NASA Robotic Neurosurgery Testbed

    NASA Technical Reports Server (NTRS)

    Mah, Robert

    1997-01-01

    The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations, In neurosurgery, the needle used in the standard stereotactic CT or MRI guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled "Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification" is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

  2. Neurosurgery in Siberia.

    PubMed

    Krivoshapkin, Alexey L; Zelman, Vladimir L

    2012-02-01

    There is archaeological evidence that the first neurosurgical procedure in what is now known as Siberia was performed in 8005 ± 100 B.C. According to signs of bone growth, perhaps more than half of the individuals who received the ancient trepanations survived. In Siberia, the first operations on the human brain and spinal cord were performed in 1909 at Tomsk University Hospital by the outstanding Russian surgeon and professor Vladimir M. Mysh. Professor Mysh initially moved from Saint Petersburg to Tomsk and later to Novosibirsk. Nicolay N. Burdenko, the founder of Russian neurosurgery and the Moscow Neurosurgical Institution, began his medical education at the Tomsk Imperial University. In the 1950s, Professor Ksenia I. Kharitonova exerted her great influence upon the development of neurosurgery in Siberia. Since 1955, and for 30 years thereafter, Professor Kharitonova was recognized as a principal leader of Siberian neurosurgery. She applied every effort to spread neurosurgical knowledge, and she popularized best practices around Siberia and the Far East. Perestroika deconstructed and ultimately eliminated the orderly system of neurosurgical service in the Soviet Union. From another perspective, the process opened the window to the world. Fully equipped centers and clinics with state-of-the-art techniques for neuro-oncology, cerebrovascular diseases, neurotrauma, and spinal pathology management in Novosibirsk, Barnaul, Kemerovo, and Irkutsk were enabled. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. The role of simulation in neurosurgery.

    PubMed

    Rehder, Roberta; Abd-El-Barr, Muhammad; Hooten, Kristopher; Weinstock, Peter; Madsen, Joseph R; Cohen, Alan R

    2016-01-01

    In an era of residency duty-hour restrictions, there has been a recent effort to implement simulation-based training methods in neurosurgery teaching institutions. Several surgical simulators have been developed, ranging from physical models to sophisticated virtual reality systems. To date, there is a paucity of information describing the clinical benefits of existing simulators and the assessment strategies to help implement them into neurosurgical curricula. Here, we present a systematic review of the current models of simulation and discuss the state-of-the-art and future directions for simulation in neurosurgery. Retrospective literature review. Multiple simulators have been developed for neurosurgical training, including those for minimally invasive procedures, vascular, skull base, pediatric, tumor resection, functional neurosurgery, and spine surgery. The pros and cons of existing systems are reviewed. Advances in imaging and computer technology have led to the development of different simulation models to complement traditional surgical training. Sophisticated virtual reality (VR) simulators with haptic feedback and impressive imaging technology have provided novel options for training in neurosurgery. Breakthrough training simulation using 3D printing technology holds promise for future simulation practice, proving high-fidelity patient-specific models to complement residency surgical learning.

  4. [Neurosurgery in antique medicine].

    PubMed

    Lindekleiv, Haakon

    2005-12-15

    Trepanation and craniotomy are two of the oldest surgical procedures known, and extensive archaeological evidence of trepanation exists in ancient cultures. However, the first descriptions of the surgical techniques are from Greek and Roman medicine, where cranial surgery was used to treat head trauma. This article concerns neurosurgery in ancient medicine, with an emphasis on "De Medicina" by Aulus Cornelius Celsus (25 BC-50 AD) and the Corpus Hippocraticum (about 400 BC). These texts are further considered in the light of excavated surgical instruments from Pompeii.

  5. [Surgical robotics in neurosurgery].

    PubMed

    Haidegger, Tamás; Benyó, Zoltán

    2009-09-06

    Surgical robotics is one of the most dynamically advancing areas of biomedical engineering. In the past few decades, computer-integrated interventional medicine has gained significance internationally in the field of surgical procedures. More recently, mechatronic devices have been used for nephrectomy, cholecystectomy, as well as in orthopedics and radiosurgery. Estimates show that 70% of the radical prostatectomies were performed with the da Vinci robot in the United States last year. Robot-aided procedures offer remarkable advantages in neurosurgery both for the patient and the surgeon, making microsurgery and Minimally Invasive Surgery a reality, and even complete teleoperation accessible. This paper introduces surgical robotic systems developed primarily for brain and spine applications, besides, it focuses on the different research strategies applied to provide smarter, better and more advanced tools to surgeons. A new system is discussed in details that we have developed together with the Johns Hopkins University in Baltimore. This cooperatively-controlled system can assist with skull base drilling to improve the safety and quality of neurosurgery while reducing the operating time. The paper presents the entire system, the preliminary results of phantom and cadaver tests and our efforts to improve the accuracy of the components. An effective optical tracking based patient motion compensation method has been implemented and tested. The results verify the effectiveness of the system and allow for further research.

  6. Neurosurgery and industry.

    PubMed

    Robertson, Jon H

    2008-12-01

    The primary purpose of the relationship between neurosurgery and industry must be to improve patient care and advance medical knowledge. This relationship is desirable and can be mutually beneficial. Strict adherence to established ethical and legal guidelines is necessary to avoid financial conflicts of interest that may occur between neurosurgery and industry. The Code of Ethics established by the American Association of Neurological Surgeons (AANS) in 1986 emphasizes the physician's responsibility to always act in the best interest of his or her patients. The AANS Guidelines for Corporate Relations were developed in 2004 to address the concern of the potential growing influence of industry in the activities of our neurosurgical organization. Recognizing a need to clarify the proper relationships between neurosurgeons and industry, Guidelines on Neurosurgeon-Industry Conflicts of Interest were recently established. The AANS is committed to the highest ethical and legal standards in future relations with our industry partners. Members of the AANS are encouraged to adhere to the voluntary guidelines established by our organization.

  7. 3D printing in neurosurgery: A systematic review.

    PubMed

    Randazzo, Michael; Pisapia, Jared M; Singh, Nickpreet; Thawani, Jayesh P

    2016-01-01

    The recent expansion of three-dimensional (3D) printing technology into the field of neurosurgery has prompted a widespread investigation of its utility. In this article, we review the current body of literature describing rapid prototyping techniques with applications to the practice of neurosurgery. An extensive and systematic search of the Compendex, Scopus, and PubMed medical databases was conducted using keywords relating to 3D printing and neurosurgery. Results were manually screened for relevance to applications within the field. Of the search results, 36 articles were identified and included in this review. The articles spanned the various subspecialties of the field including cerebrovascular, neuro-oncologic, spinal, functional, and endoscopic neurosurgery. We conclude that 3D printing techniques are practical and anatomically accurate methods of producing patient-specific models for surgical planning, simulation and training, tissue-engineered implants, and secondary devices. Expansion of this technology may, therefore, contribute to advancing the neurosurgical field from several standpoints.

  8. History of Neurosurgery in Palestine.

    PubMed

    Darwazeh, Rami; Darwazeh, Mazhar; Sun, Xiaochuan

    2017-08-01

    Palestinian neurosurgery started with Dr. Antone Tarazi as the first Palestinian neurosurgeon. Before that, there was no organized neurosurgery specialty, and general surgeons performed neurosurgical procedures. Here we review the history of neurosurgery and neurosurgical applications in Palestine, evaluate some limitations of the current system, and discuss major challenges to improving this system. We collected information from various sources in either English or Arabic. The development of neurosurgery and neurosurgical training in Palestine began in 1960 with the first center established in Jerusalem, which provided much-needed neurosurgical services and training in the fields of neurosurgery and neurology. Palestine has produced a number of its own neurosurgeons and has promoted further progress by establishing the Palestinian Neurosurgical Society in 2014. Today, there are 34 neurosurgeons (including 1 female neurosurgeon) and 17 residents providing expert care in 17 centers across Palestine, along with 1 neurosurgical residency program. Neurosurgery in Palestine has faced many challenges, some of which have been overcome. However, there remain many challenges, which will require much time and effort to surmount. Political stabilization is a significant factor in the progress of neurosurgery in Palestine. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The roles of functional MRI in MR-guided neurosurgery in a combined 1.5 Tesla MR-operating room.

    PubMed

    Liu, H; Hall, W A; Truwit, C L

    2003-01-01

    During MR-guided neurosurgical procedures performed in a combined 1.5 Tesla MR-operating room (MR-OR), we have successfully implemented and validated a functional MRI (fMRI) scheme for efficiently localizing eloquent functional areas and assessing their proximity to a lesion volume immediately prior to the craniotomy. The fMRI examination consists of a dynamical blood oxygenation level dependent (BOLD) MR imaging technique and a task paradigm that is designed to activate the brain area of interest. The functional imaging technique was based on gradient-echo (GE) echo-planar imaging (EPI) (TR/TE = 2000-3000/40-50 msec). The motor task paradigm involves a periodic movement task, such as alternating between thumb and the other four fingers as a finger-tapping task, while the language involved a covert repeat of a series of words given as a task stimulus. While patient is performing the task, a dynamical fMRI was performed concurrently covering the volume of interest every 2 or 3 sec. Also, we have used a temporal series averaging (TSA) method for correcting the background drift in the raw fMRI signal, and developed a scheme for presenting fMRI results to neurosurgeons in an intuitive 3-dimensional volume-rendered display format. By using the fMRI scheme, we have successfully performed sixteen fMRI examinations immediately prior to neurosurgery in the combined MR-OR on the same surgical table to localize various eloquent functional areas of interests. TSA was successful in reducing the background drift in the fMRI time course data, and the 3-dimensional volume-rendered display was proven effective in presenting the resulting brain activations to neurosurgeons. More importantly, in three representative cases (one biopsy and two tumor resections) presented, the information provided by fMRI have indeed contributed significantly in making the optimal surgical decisions prior to craniotomy. Intra-operative fMRI can be an indispensable tool for determining the location of a

  10. Use of the Radionics Image Fusiontrade mark and Stereoplantrade mark programs for target localization in functional neurosurgery.

    PubMed

    Papanastassiou, V; Rowe, J; Scott, R; Silburn, P; Davies, L; Aziz, T

    1998-01-01

    We describe the use of Radionics Image Fusiontrade mark and Stereoplantrade mark in defining the target for thalamotomy and pallidotomy in functional surgery for parkinsonism and tremor. Using this to fuse and spatially correct magnetic resonance imaging (MRI) to computed tomography (CT) images our calculated targets were a mean of 0.6 +/- 1.5 mm from the end target determined physiologically by stimulation. This is significantly better than the values of 2.6 +/- 1.6 mm for thalamic targets and 7.1 +/- 3.7 mm for pallidal targets using CT alone. As a consequence, determination of the target and the lesion making are routinely performed in one pass of the electrode allowing for faster, more accurate and, we believe, safer functional procedures.

  11. Neurosurgery and clinical engineering.

    PubMed

    Salcman, M; Samaras, G M

    1978-01-01

    Modern technology has profoundly altered the clinical practice of neurosurgery. For a wide variety of conditions, patients are being implanted with active and passive devices or treated with advanced microsurgical instrumentation. After surgery, such patients are sent to modern intensive-care units employing the latest advances in patient monitoring and computer technology. We contend that the responsibilities of the Clinical Engineer extend beyond simple installation and maintenance of equipment and systems. It is essential that he take part in the continuing education of non-technical personnel who must make use of the equipment in ways that are meaningful in the care of the patient and to the progress of clinical science. This point is illustrated by our experience with a neurosurgical intensive-care unit. It is also the thesis of this paper that the design and maintenance of increasingly sophisticated biomedical systems will benefit from the use of an interdisciplinary approach at the very inception of a project. This approach is illustrated by our current development of a multibeam microwave hyperthermia system for possible use in the treatment of brain tumors.

  12. Mythology and Neurosurgery.

    PubMed

    Ökten, Ali İhsan

    2016-06-01

    Myths are the keystone of mythology. They are interpretations of events that have been told as stories and legends for thousands of years, inherited from generation to generation, and have reached the present day. Although most myths are considered figments of the imagination or fictitious legends, all of them contain references to facts from the time they occurred. Mythology, which is a collection of figments of imagination concerning nature and human beings, is a product of human effort to perceive, explain, and interpret the universe and the world, much like science. The interaction between mythology and science dates back to the early days of civilization. Mythology, a reflection of human creativity, is extensively used in modern science, particularly in a terminological context. This article aims to reveal the texture of mythology in neurosurgery, by analyzing the birth of medicine in mythology; heroes such as Apollo and Asklepios, the gods of healing and medicine, as well as Hygieia, the goddess of health and hygiene; and mythological terms and phrases such as Achilles tendon, atlas vertebra, gigantism, priapism syndrome, hippocampus, lethargy, syrinx, and arachnoid. Through the use of symbols, mythology has attempted to explain several subjects, such as human nature, disease, birth, and death. In this respect, mythology and medicine dance arm in arm, and this dance has been going on for centuries. As a result, mythology has manifested itself in many fields within medicine, either anatomically or by giving names to various diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. [African neurosurgery. 1: Historical outline].

    PubMed

    el Khamlichi, A

    1996-01-01

    This outline of the history of African Neurosurgery explains the role that North Africa has played in the Middle Ages in the development of Neurosurgery, the origins of the development of the latter in twentieth century, and the delay that African Neurosurgery still shows at the present time in the majority of African countries. On the papyrus of the pharaonic era, we have found the description of some neurosurgical procedures such as trephination and brain aspiration by a transphenoidal approach used before mummification. It is particularly trephination which summarizes the ancient history of African neurosurgery, as it was widely used throughout the continent, practised and taught by healers in African tribes. The technical concepts of trephination are based, to a great extent, on the descriptions of Arab physicians of the Middle Ages. It was at that time (Middle Ages) that several Arab physicians such as Avicenne, Rhazes, and Avenzhoer described many types of nervous system diseases and the techniques to treat them. But it was mainly Abulkassim Al Zahraoui (Abulkassis) who was the pioneer of neurosurgery as he devoted one volume of his treatise (made up of 30 volumes) to neurosurgery, a precise description of many aspects of neurosurgical pathology, its treatment, instruments and neurosurgical techniques. We have reported in this article five original extracts in Arabic which deal with skull fractures and their treatment, vertebro-medullary traumas and their treatment, hydrocephalus and its treatment, tumors of the skull vault and their treatment, and finally the basic knowledge of anatomy which is of great interest for a surgeon. The medical knowledge of that time which gave birth to medical schools and hospitals was transmitted progressively to Europe and played an important role in the development of medicine during the European Renaissance in the fifteenth and sixteenth centuries. During colonization, neurosurgical practice started and developed in many

  14. History of Neurosurgery in Malaysia.

    PubMed

    Raffiq, Azman; Abdullah, Jafri Malin; Haspani, Saffari; Adnan, Johari Siregar

    2015-12-01

    The development of neurosurgical services and training in Malaysia began in 1963, with the first centre established in its capital city at Hospital Kuala Lumpur, aimed to provide much needed neurosurgical services and training in the field of neurology and neurosurgery. This center subsequently expanded in 1975 with the establishment of the Tunku Abdul Rahman Neuroscience Institute (IKTAR); which integrated the three allied interdependent disciplines of neurosurgery, neurology and psychiatry. The establishment of this institute catalysed the rapid expansion of neurosurgical services in Malaysia and paved the way for development of comprehensive training for doctors, nurses, and paramedics. This culminated in the establishments of a local comprehensive neurosurgery training program for doctors in 2001; followed by a training program for nurses and paramedics in 2006. To date, there are more than 60 neurosurgeons providing expert care in 11 centers across Malaysia, along with trained personnel in the field of neurosciences.

  15. Progress of women in neurosurgery.

    PubMed

    Spetzler, Robert F

    2011-01-01

    Despite advances in issues related to gender equity, barriers to recruiting and retaining women in neurosurgery continue to exist. At the same time, the overall projected shortage of neurosurgeons suggests that women will be vital to the long-term success of the field. Attracting women to neurosurgery can capitalize on strategies, such as mentoring, teaching leadership and negotiating skills, and job sharing or dual training tracks to name a few, that would benefit both men and women passionate about pursuing neurosurgery. Ultimately, personal and institutional accountability must be evaluated to ensure that the best and brightest candidates, regardless of gender, are recruited to neurosurgical programs to promote the health of our challenging but most satisfying profession.

  16. [New simulation technologies in neurosurgery].

    PubMed

    Byvaltsev, V A; Belykh, E G; Konovalov, N A

    2016-01-01

    The article presents a literature review on the current state of simulation technologies in neurosurgery, a brief description of the basic technology and the classification of simulation models, and examples of simulation models and skills simulators used in neurosurgery. Basic models for the development of physical skills, the spectrum of available computer virtual simulators, and their main characteristics are described. It would be instructive to include microneurosurgical training and a cadaver course of neurosurgical approaches in neurosurgery training programs and to extend the use of three-dimensional imaging. Technologies for producing three-dimensional anatomical models and patient-specific computer simulators as well as improvement of tactile feedback systems and display quality of virtual models are promising areas. Continued professional education necessitates further research for assessing the validity and practical use of simulators and physical models.

  17. History of Neurosurgery in Malaysia

    PubMed Central

    RAFFIQ, Azman; ABDULLAH, Jafri Malin; HASPANI, Saffari; ADNAN, Johari Siregar

    2015-01-01

    The development of neurosurgical services and training in Malaysia began in 1963, with the first centre established in its capital city at Hospital Kuala Lumpur, aimed to provide much needed neurosurgical services and training in the field of neurology and neurosurgery. This center subsequently expanded in 1975 with the establishment of the Tunku Abdul Rahman Neuroscience Institute (IKTAR); which integrated the three allied interdependent disciplines of neurosurgery, neurology and psychiatry. The establishment of this institute catalysed the rapid expansion of neurosurgical services in Malaysia and paved the way for development of comprehensive training for doctors, nurses, and paramedics. This culminated in the establishments of a local comprehensive neurosurgery training program for doctors in 2001; followed by a training program for nurses and paramedics in 2006. To date, there are more than 60 neurosurgeons providing expert care in 11 centers across Malaysia, along with trained personnel in the field of neurosciences. PMID:27006632

  18. Progress of women in neurosurgery

    PubMed Central

    Spetzler, Robert F.

    2011-01-01

    Despite advances in issues related to gender equity, barriers to recruiting and retaining women in neurosurgery continue to exist. At the same time, the overall projected shortage of neurosurgeons suggests that women will be vital to the long-term success of the field. Attracting women to neurosurgery can capitalize on strategies, such as mentoring, teaching leadership and negotiating skills, and job sharing or dual training tracks to name a few, that would benefit both men and women passionate about pursuing neurosurgery. Ultimately, personal and institutional accountability must be evaluated to ensure that the best and brightest candidates, regardless of gender, are recruited to neurosurgical programs to promote the health of our challenging but most satisfying profession. PMID:22059098

  19. Neurosurgery and Music; Effect of Wolfgang Amadeus Mozart.

    PubMed

    Gasenzer, Elena Romana; Kanat, Ayhan; Neugebauer, Edmund

    2017-06-01

    The nervous system works like a great orchestra. Specifically, the music of Mozart with its "Mozart effect" is appropriate to use in neurosurgery. We investigated the relationship between Mozart's music and neurosurgery. We used digital catalogs like "PubMed" and the libraries of universities. Key words were "Wolfgang Amadeus Mozart" and "neurosurgery and music." In the first half of the 20th century, performing neurosurgery on some musicians, such as Maurice Ravel, Josef Hassid, and George Gershwin, resulted in a fatal outcome. The cause of this is probably that neurosurgery had not been developed yet in the first half of the 20th century. In the past 3 decades, the neurosurgical operations of musicians show that musicians have rich associations among auditory, somatic, and sensorial systems. It is clear that we have much to learn from studies about music and brain function that derive from our surgical experiences with patients. The neuronal plasticity of musicians' brains may be different from that of nonmusicians' brains. Musicians with enhanced motor skills have greater capacity for plasticity because of enriched interhemispheric connections. Listening to music and the effect of Mozart in neurosurgical practice, intensive care, or rehabilitation were documented in many studies. As authors, we mean something different: Its effectiveness should be studied. We concluded that in current neurosurgical practice, Mozart has an effect. More research and clinical studies are needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. [Evolution of Egyptian neurosurgery: an overview].

    PubMed

    Orief, Tamer

    2010-02-01

    This article describes the evolution of Egyptian neurosurgery. It highlights the experiences of the ancient Egyptians in treatment of the central nervous system diseases. These experiences were documented through their papyrus writings and their drawings over the walls in ancient temples. The aim of this article is not only to search for the roots of neurosurgery in Egypt but also to showcase the present and future status of neurosurgery. Neurosurgery developed as a specialty earlier in Egypt and has led the development of this specialty in Africa and the Middle East. It is worthwhile tracing the history of neurosurgery of past civilizations, ancient medicine, and the work of pioneers.

  1. Development of a new microsurgical robot for stereotactic neurosurgery.

    PubMed

    Koyama, H; Uchida, T; Funakubo, H; Takakura, K; Fankhauser, H

    1990-01-01

    The robot technology was introduced into a new stereotactic neurosurgery system for applications to biopsy, blind surgery, and functional neurosurgery. The authors have developed a newly designed prototype microsurgical robot, designed to allow a biopsy needle to reach the target such as a cerebral tumor within a brain automatically on the basis of the X, Y, and Z coordinates obtained by CT scanner. This robot is so small that it can be driven in a CT scanner gantry. It consists mainly of the link mechanism and the insertion mechanism. We constructed the link mechanism and investigated its working space.

  2. Stereotactic neurosurgery for Parkinson's disease.

    PubMed

    Giller, C A; Dewey, R B

    1995-03-01

    The Council on Scientific Affairs of the California Medical Association presents the following epitomes of progress in neurosurgery. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and clinical importance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of progress in medicine, whether in their own field of special interest or another. The epitomes included here were selected by the Advisory Panel to the Section on Neurosurgery of the California Medical Association, and the summaries were prepared under the direction of John H. Neal, MD, and the panel.

  3. Artificial neural networks in neurosurgery.

    PubMed

    Azimi, Parisa; Mohammadi, Hasan Reza; Benzel, Edward C; Shahzadi, Sohrab; Azhari, Shirzad; Montazeri, Ali

    2015-03-01

    Artificial neural networks (ANNs) effectively analyze non-linear data sets. The aimed was A review of the relevant published articles that focused on the application of ANNs as a tool for assisting clinical decision-making in neurosurgery. A literature review of all full publications in English biomedical journals (1993-2013) was undertaken. The strategy included a combination of key words 'artificial neural networks', 'prognostic', 'brain', 'tumor tracking', 'head', 'tumor', 'spine', 'classification' and 'back pain' in the title and abstract of the manuscripts using the PubMed search engine. The major findings are summarized, with a focus on the application of ANNs for diagnostic and prognostic purposes. Finally, the future of ANNs in neurosurgery is explored. A total of 1093 citations were identified and screened. In all, 57 citations were found to be relevant. Of these, 50 articles were eligible for inclusion in this review. The synthesis of the data showed several applications of ANN in neurosurgery, including: (1) diagnosis and assessment of disease progression in low back pain, brain tumours and primary epilepsy; (2) enhancing clinically relevant information extraction from radiographic images, intracranial pressure processing, low back pain and real-time tumour tracking; (3) outcome prediction in epilepsy, brain metastases, lumbar spinal stenosis, lumbar disc herniation, childhood hydrocephalus, trauma mortality, and the occurrence of symptomatic cerebral vasospasm in patients with aneurysmal subarachnoid haemorrhage; (4) the use in the biomechanical assessments of spinal disease. ANNs can be effectively employed for diagnosis, prognosis and outcome prediction in neurosurgery. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Assessing the Relevancy of "Citation Classics" in Neurosurgery. Part II: Foundational Papers in Neurosurgery.

    PubMed

    Bohl, Michael A; Turner, Jay D; Little, Andrew S; Nakaji, Peter; Ponce, Francisco A

    2017-08-01

    The second part of this study reanalyzes Ponce and Lozano's (2010) list of classics to create a new list of "foundational" articles in neurosurgery. Ponce and Lozano (2010) previously published a list of 106 neurosurgery classics, as defined by Garfield and his 400 citation criterion. We used the Web of Science citation reports to create graphs for each study showing the total citations it received as a function of time. Each graph was subjectively analyzed independently and scored as "foundational" or "classic only," based on whether the trend of citations received per year was uptrending, neutral, or downtrending. Of the 101 evaluated classics, 53 qualified as foundational. Over half of these studies were published in Journal of Neurosurgery (13), New England Journal of Medicine (12), or Lancet (5). Grading systems, randomized trials, and prospective studies were most likely to achieve foundational status. Only 30% of functional and 17% of endovascular classics qualified as foundational (compared with 100% of spine classics), suggesting that these fields are rapidly changing or less mature subspecialties still developing a foundational literature base. By assessing citation counts as a function of time, we are able to differentiate classic neurosurgical studies that are critical to modern-day practice from those that are primarily of historic interest. Given the exponential growth of literature in our field, analyses such as these will become increasingly important to both trainees and senior neurosurgeons who strive to educate themselves on the data that drive modern-day clinical decision making. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. 3D printing in neurosurgery: A systematic review

    PubMed Central

    Randazzo, Michael; Pisapia, Jared M.; Singh, Nickpreet; Thawani, Jayesh P.

    2016-01-01

    Background: The recent expansion of three-dimensional (3D) printing technology into the field of neurosurgery has prompted a widespread investigation of its utility. In this article, we review the current body of literature describing rapid prototyping techniques with applications to the practice of neurosurgery. Methods: An extensive and systematic search of the Compendex, Scopus, and PubMed medical databases was conducted using keywords relating to 3D printing and neurosurgery. Results were manually screened for relevance to applications within the field. Results: Of the search results, 36 articles were identified and included in this review. The articles spanned the various subspecialties of the field including cerebrovascular, neuro-oncologic, spinal, functional, and endoscopic neurosurgery. Conclusions: We conclude that 3D printing techniques are practical and anatomically accurate methods of producing patient-specific models for surgical planning, simulation and training, tissue-engineered implants, and secondary devices. Expansion of this technology may, therefore, contribute to advancing the neurosurgical field from several standpoints. PMID:27920940

  6. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery

    PubMed Central

    Dyster, Timothy G.; Mikell, Charles B.; Sheth, Sameer A.

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field’s history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine. PMID:27445706

  7. Functional Neurosurgery in the Treatment of Severe Obsessive Compulsive Disorder and Major Depression: Overview of Disease Circuits and Therapeutic Targeting for the Clinician

    PubMed Central

    Shah, Dhwani B.; Pesiridou, Angeliki; Baltuch, Gordon H.; Malone, Donald A.; O’Reardon, John P.

    2008-01-01

    Over the past 20 years, there has been a concerted effort to expand our understanding of the neural circuitry involved in the pathogenesis of psychiatric disorders. Distinct neuronal circuits and networks have been implicated in obsessive compulsive disorder (OCD) and major depressive disorder (MDD) involving feedback loops between the cortex, striatum, and thalamus. When neurosurgery is used as a therapeutic tool in severe OCD and MDD, the goal is to modulate specific targets or nodes within these networks in an effort to produce symptom relief. Currently, four lesioning neurosurgical procedures are utilized for treatment refractory OCD and MDD: cingulotomy, capsulotomy, subcaudate tractotomy, and limbic leucotomy. Deep brain stimulation (DBS) is a novel neurosurgical approach that has some distinct advantages over lesioning procedures. With DBS, the desired clinical effect can be achieved by reversible, high frequency stimulation in a nucleus or at a node in the circuit without the need to produce an irreversible lesion. Recent trials of deep brain stimulation in both OCD and MDD at several neuroanatomical targets have reported promising early results in highly refractory patients and with a good safety profile. Future definitive trials in MDD and OCD are envisaged. PMID:19727257

  8. Anaesthesia for elective neurosurgery.

    PubMed

    Dinsmore, J

    2007-07-01

    Neuroanaesthesia continues to develop and expand. It is a speciality where the knowledge and expertise of the anaesthetist can directly influence patient outcome. Evolution of neurosurgical practice is accompanied by new challenges for the anaesthetist. Increasingly, we must think not only as an anaesthetist but also as a neurosurgeon and neurologist. With the focus on functional and minimally invasive procedures, there is an increased emphasis on the provision of optimal operative conditions, preservation of neurocognitive function, minimizing interference with electrophysiological monitoring, and a rapid, high-quality recovery. Small craniotomies, intraoperative imaging, stereotactic interventions, and endoscopic procedures increase surgical precision and minimize trauma to normal tissues. The result should be quicker recovery, minimal perioperative morbidity, and reduced hospital stay. One of the peculiarities of neuroanaesthesia has always been that as much importance is attached to wakening the patient as sending them to sleep. With the increasing popularity of awake craniotomies, there is even more emphasis on this skill. However, despite high-quality anaesthetic research and advances in drugs and monitoring modalities, many controversies remain regarding best clinical practice. This review will discuss some of the current controversies in elective neurosurgical practice, future perspectives, and the place of awake craniotomies in the armamentarium of the neuroanaesthetist.

  9. Virtual neurosurgery, training for the future.

    PubMed

    Vloeberghs, M; Glover, A; Benford, S; Jones, A; Wang, P; Becker, Adib

    2007-06-01

    Virtual reality (VR) simulators have been created for various surgical specialties. The common theme is extensive use of graphics, confined spaces, limited functionality and limited tactile feedback. A development team at the University of Nottingham, UK, consisting of computer scientists, mechanical engineers, graphic designers and a neurosurgeon, set out to develop a haptic, e.g. tactile simulator for neurosurgery making use of boundary elements (BE). The relative homogeneity of the brain, allows boundary elements, e.g. 'surface only' rendering, to simulate the brain structure. A boundary element simplifies the computing equations saves computing time, by assuming the properties of the surface equal the properties of the body. A limited audit was done by neurosurgical users confirming the potential of the simulator as a training tool. This paper focuses on the application of the computational method and refers to the underlying mathematical structure. Full references are included regarding the mathematical methodology.

  10. Dynamic hub load predicts cognitive decline after resective neurosurgery.

    PubMed

    Carbo, Ellen W S; Hillebrand, Arjan; van Dellen, Edwin; Tewarie, Prejaas; de Witt Hamer, Philip C; Baayen, Johannes C; Klein, Martin; Geurts, Jeroen J G; Reijneveld, Jaap C; Stam, Cornelis J; Douw, Linda

    2017-02-07

    Resective neurosurgery carries the risk of postoperative cognitive deterioration. The concept of 'hub (over)load', caused by (over)use of the most important brain regions, has been theoretically postulated in relation to symptomatology and neurological disease course, but lacks experimental confirmation. We investigated functional hub load and postsurgical cognitive deterioration in patients undergoing lesion resection. Patients (n = 28) underwent resting-state magnetoencephalography and neuropsychological assessments preoperatively and 1-year after lesion resection. We calculated stationary hub load score (SHub) indicating to what extent brain regions linked different subsystems; high SHub indicates larger processing pressure on hub regions. Dynamic hub load score (DHub) assessed its variability over time; low values, particularly in combination with high SHub values, indicate increased load, because of consistently high usage of hub regions. Hypothetically, increased SHub and decreased DHub relate to hub overload and thus poorer/deteriorating cognition. Between time points, deteriorating verbal memory performance correlated with decreasing upper alpha DHub. Moreover, preoperatively low DHub values accurately predicted declining verbal memory performance. In summary, dynamic hub load relates to cognitive functioning in patients undergoing lesion resection: postoperative cognitive decline can be tracked and even predicted using dynamic hub load, suggesting it may be used as a prognostic marker for tailored treatment planning.

  11. Dynamic hub load predicts cognitive decline after resective neurosurgery

    PubMed Central

    Carbo, Ellen W. S.; Hillebrand, Arjan; van Dellen, Edwin; Tewarie, Prejaas; de Witt Hamer, Philip C.; Baayen, Johannes C.; Klein, Martin; Geurts, Jeroen J. G.; Reijneveld, Jaap C.; Stam, Cornelis J.; Douw, Linda

    2017-01-01

    Resective neurosurgery carries the risk of postoperative cognitive deterioration. The concept of ‘hub (over)load’, caused by (over)use of the most important brain regions, has been theoretically postulated in relation to symptomatology and neurological disease course, but lacks experimental confirmation. We investigated functional hub load and postsurgical cognitive deterioration in patients undergoing lesion resection. Patients (n = 28) underwent resting-state magnetoencephalography and neuropsychological assessments preoperatively and 1-year after lesion resection. We calculated stationary hub load score (SHub) indicating to what extent brain regions linked different subsystems; high SHub indicates larger processing pressure on hub regions. Dynamic hub load score (DHub) assessed its variability over time; low values, particularly in combination with high SHub values, indicate increased load, because of consistently high usage of hub regions. Hypothetically, increased SHub and decreased DHub relate to hub overload and thus poorer/deteriorating cognition. Between time points, deteriorating verbal memory performance correlated with decreasing upper alpha DHub. Moreover, preoperatively low DHub values accurately predicted declining verbal memory performance. In summary, dynamic hub load relates to cognitive functioning in patients undergoing lesion resection: postoperative cognitive decline can be tracked and even predicted using dynamic hub load, suggesting it may be used as a prognostic marker for tailored treatment planning. PMID:28169349

  12. Challenges in contemporary academic neurosurgery.

    PubMed

    Black, Peter M

    2006-03-01

    Traditionally, the ideal academic neurosurgeon has been a "quadruple threat," with excellence in clinical work, teaching, research, and administration. This tradition was best exemplified in Harvey Cushing, who developed the field of neurosurgery 90 years ago. This paradigm will probably have to change as academic neurosurgeons face major challenges. In patient care, these include increasing regulatory control, increasing malpractice costs, consolidation of expensive care in academic centers, and decreasing reimbursement; in resident teaching, work hour limitations and a changing resident culture; in research, the increasing dominance of basic scientists in governmental funding decisions and decreased involvement of neurosurgeons in scientific review committees; and in administration, problems of relationships in the workplace, patient safety, and employment compliance in an increasingly bureaucratic system. To meet these challenges, the new academic neurosurgeon will probably not be a quadruple threat personally but will be part of a quadruple threat in a department and institution. Neurosurgeons in such a setting will have to work with hospital, medical school, and national and international groups to address malpractice, reimbursement, subspecialization, and training problems; find supplemental sources of income through grants, development funds, and hospital support; lead in the development of multidisciplinary centers for neuroscience, brain tumor, spine, and other initiatives; and focus on training leaders for hospital, regional, and national groups to reconfigure neurosurgery. Collaboration, flexibility, and leadership will be characteristic of the academic neurosurgeon in this new era.

  13. Renaissance Neurosurgery: Italy's Iconic Contributions.

    PubMed

    Nanda, Anil; Khan, Imad Saeed; Apuzzo, Michael L

    2016-03-01

    Various changes in the sociopolitical milieu of Italy led to the increasing tolerance of the study of cadavers in the late Middle Ages. The efforts of Mondino de Liuzzi (1276-1326) and Guido da Vigevano (1280-1349) led to an explosion of cadaver-centric studies in centers such as Bologna, Florence, and Padua during the Renaissance period. Legendary scientists from this era, including Leonardo Da Vinci, Andreas Vesalius, Bartolomeo Eustachio, and Costanzo Varolio, furthered the study of neuroanatomy. The various texts produced during this period not only helped increase the understanding of neuroanatomy and neurophysiology but also led to the formalization of medical education. With increased understanding came new techniques to address various neurosurgical problems from skull fractures to severed peripheral nerves. The present study aims to review the major developments in Italy during the vibrant Renaissance period that led to major progress in the field of neurosurgery.

  14. Registration in neurosurgery and neuroradiotherapy applications.

    PubMed

    Cuchet, E; Knoplioch, J; Dormont, D; Marsault, C

    1995-01-01

    Because of the high level of accuracy needed in neurosurgery, many computer-assisted surgery (CAS) and augmented reality techniques have been developed in this field. A common issue with all of these techniques is registration between preoperative three-dimensional images (computed tomography and magnetic resonance imaging) and the patient in the operating room. We present, in the first part of this paper, a survey of the latest CAS technologies, using fully automatic registration without fiducial landmarks. All of the registration algorithms described are based on minimization of a cost function. We then describe our approach. Our cost function is simply the mean square error (MSE), minimized by the iterative closest point algorithm (ICP). Because the weak point of the ICP algorithm is the closest point computational cost, we precalculate it by a "closest point map," inspired from classical distance map. We finally perturb the found solution to eliminate local minima close to the global minimum. This paper summarizes the various methods presented. We study the shape of the different cost functions and show that there is no need for a complex cost function. MSE has sufficiently good convergence properties to reach a position very close to the global minimum. We also demonstrate the influence of a final perturbation of the found solution to improve registration. Finally, we test the registration on different regions of the patient's head.

  15. Impact of Neurosurgery Medical Student Research Grants on Neurosurgery Residency Choice.

    PubMed

    Awad, Ahmed J; Sarkiss, Christopher A; Kellner, Christopher P; Steinberger, Jeremy; Mascitelli, Justin R; Oermann, Eric K; Pain, Margaret; De Leacy, Reade; Shrivastava, Raj; Bederson, Joshua B; Mocco, J

    2016-08-01

    Recent decades have seen a rapid expansion of involvement of medical students in biomedical research during medical school training. Research within medical school has been shown to influence medical students with regard to medical knowledge, career development, and residency specialty choice. The objective of this study was to evaluate the impact of neurosurgery medical student research grants on neurosurgery residency choice and provide an insight on the demographics of grant awardees. In this retrospective study, a search of award recipients was performed using data available on the American Association of Neurological Surgeons, Congress of Neurological Surgeons, and Neurosurgery Research and Education Foundation websites. Searched years included the first cycle of American Association of Neurological Surgeons/Neurosurgery Research and Education Foundation (2007) and Council of State Neurosurgical Societies/Congress of Neurological Surgeons (2008-2009) grant awards until the 2015-2016 cycle, which is the latest award cycle to date. The initial search yielded 163 research grants that were awarded to 158 students between the years of 2007 and 2016. Among the 163 grant recipients, 126 (77.3%) were men. Among the 88 recipients who entered postgraduate residency programs, 51% (45 of 88) matched into neurosurgery residency. When considering both neurosurgery and neurology residency programs, the percentage increased to 59.1% (52 of 88). Neurosurgery grants for medical students are highly successful in producing future neurosurgeons with >50% of grant recipients matched into neurosurgery. Women are underrepresented in neurosurgery grants and neurosurgery residency programs. This situation can be improved by providing insight about the field early in medical school, perhaps through increased use of neurosurgery medical student grants. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Experimental Evolution and Heart Function in Drosophila.

    PubMed

    Shahrestani, Parvin; Burke, Molly K; Birse, Ryan; Kezos, James N; Ocorr, Karen; Mueller, Laurence D; Rose, Michael R; Bodmer, Rolf

    Drosophila melanogaster is a good model species for the study of heart function. However, most previous work on D. melanogaster heart function has focused on the effects of large-effect genetic variants. We compare heart function among 18 D. melanogaster populations that have been selected for altered development time, aging, or stress resistance. We find that populations with faster development and faster aging have increased heart dysfunction, measured as percentage heart failure after electrical pacing. Experimental evolution of different triglyceride levels, by contrast, has little effect on heart function. Evolved differences in heart function correlate with allele frequency changes at many loci of small effect. Genomic analysis of these populations produces a list of candidate loci that might affect cardiac function at the intersection of development, aging, and metabolic control mechanisms.

  17. [Changing the teaching of neurosurgery with information technology].

    PubMed

    Moreau, Jean-Jacques; Caire, François; Kalamarides, Michel; Mireau, Etienne; Dauger, Frédéric; Coignac, Marie-Jo; Charlin, Bernard

    2009-10-01

    A digital campus is a distance learning site that uses the potential of information and communication technologies to disseminate and improve educational services. This website, with open and free access, is built from free software with Web 2.0 technology. It is hosted at the University of Limoges. It functions as a digital library, containing scanned books, slide shows, more than 200 hours of recorded courses and round tables accessible by streaming video. The site is indexed according to the users' needs, by level of knowledge, specialty, keywords, and supplementary MeSH terms. The campus is organized as the College of Neurosurgery (http://college.neurochirurgie.fr). The durability of this type of training (in existence for 9 years now) is made possible by a powerful and committed consortium: the French Society of Neurosurgery, which has created high-quality intellectual and scientific resources, the University of Limoges, the Dupuytren University Hospital Center in Limoges, the region of Limousin, and the French-language Virtual Medical University, which have provided logistic and financial support. To target appropriate levels at various users, we distinguished four groups: medical students, neurosurgery students, neurosurgeons (continuing medical education), and students in allied health fields. All areas of neurosurgery are concerned. All the courses, including tests for self-evaluation and scientific meetings (organized with information and communication technologies) are digitally recorded for the site. The principles that make it possible for a medical discipline to organize around an online project are: a pedagogical conception of projects built in the form of models reusable by other health specialties; a stronghold within professional societies of the relevant specialties able to create high-quality intellectual and scientific resources; an organization by educational levels that can be extended transversally to other health disciplines; and free

  18. Clovis Vincent (1879-1947): founder of French neurosurgery and promoter of oncologic neurosurgery.

    PubMed

    Karamanou, M; Androutsos, G; Lymperi, M; Stamboulis, E; Liappas, I; Lykouras, E

    2012-01-01

    The eminent neurologist Clovis Vincent decided to become neurosurgeon at an advanced age. His is considered the founder of French neurosurgery and the Europe's first neurosurgeon. He was mainly interested in pituitary tumors and his work on oncologic neurosurgery remains valuable.

  19. [Sepsis and antibiotic prophylaxis in stereotaxic neurosurgery].

    PubMed

    Padrón-Sánchez, A; Ochoa-Zaldivar, L; López-Flores, G; García-Maeso, I; Barnés-Domínguez, J A; Reconde-Suárez, D

    Stereotaxic surgery is becoming increasingly important because of the possibility of approaching the deep zones of the brain with less risk. It is in daily use in cerebral tumours and in the functional surgery of Parkinson's disease. The use of antibiotic prophylaxis in neurosurgery is controversial, although in many centres, including ours, all patients receive it. To study the pre-operative clinical characteristics analysing the antibiotic prophylaxis used, septic complications seen and their management. In this study we included 93 patients with neurosurgical disorders operated on using a stereotaxic approach in the Neurosurgical Department of the Centro Internacional de Restauración Neurologica (Cuba) during 1997 and 1998, in which antibiotic prophylaxis was used and septic patients detected. The variables studied included age, sex, neurological disorders, surgical operations done and the antibiotic used for prophylaxis. We analysed the test of clinical criteria for sepsis in all patients. We found that a greater number of patients operated on had had functional surgery, which showed its importance as an alternative surgical method in Parkinson's disease. There was satisfactory use of antibiotic prophylaxis with a reduction in the rate of nosocomial infection; most infections were seen in the lower respiratory tract. These results support the hypothesis of use of antibiotic prophylaxis in stereotaxic surgery to achieve a reduction in intra-hospital infections in surgical patients.

  20. Global Neurosurgery: The Unmet Need.

    PubMed

    Park, Kee B; Johnson, Walter D; Dempsey, Robert J

    2016-04-01

    Globally, the lack of access to basic surgical care causes 3 times as much deaths as HIV/AIDS, tuberculosis, and malaria combined. The magnitude of this unmet need has been described recently, and the numbers are startling. Major shifts in global health agenda have highlighted access to essential and emergency surgery as a high priority. A broad examination of the current global neurosurgical efforts to improve access has revealed some strengths, particularly in the realm of training; however, the demand grossly outstrips the supply; most people in low-income countries do not have access to basic surgical care, either due to lack of availability or affordability. Projects that help create a robust and resilient health system within low- and middle-income countries require urgent implementation. In this context, concurrent scale-up of human resources, investments in capacity building, local data collection, and analysis for accurate assessment are essential. In addition, through process of collaboration and consensus building within the neurosurgical community, a unified voice of neurosurgery is necessary to effectively advocate for all those who need neurosurgical care wherever, whenever. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Technological innovation in neurosurgery: a quantitative study.

    PubMed

    Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

    2015-07-01

    Technological innovation within health care may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technology-intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical techniques. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation, respectively. The authors searched a patent database for articles published between 1960 and 2010 using the Boolean search term "neurosurgeon OR neurosurgical OR neurosurgery." The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top-performing technology cluster was then selected as an exemplar for a more detailed analysis of individual patents. In all, 11,672 patents and 208,203 publications related to neurosurgery were identified. The top-performing technology clusters during these 50 years were image-guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes, and endoscopes. In relation to image-guidance and neuromodulation devices, the authors found a highly correlated rapid rise in the numbers of patents and publications, which suggests that these are areas of technology expansion. An in-depth analysis of neuromodulation-device patents revealed that the majority of well-performing patents were related to deep brain stimulation. Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery.

  2. Magnetic resonance susceptibility weighted imaging in neurosurgery: current applications and future perspectives.

    PubMed

    Di Ieva, Antonio; Lam, Timothy; Alcaide-Leon, Paula; Bharatha, Aditya; Montanera, Walter; Cusimano, Michael D

    2015-12-01

    Susceptibility weighted imaging (SWI) is a relatively new imaging technique. Its high sensitivity to hemorrhagic components and ability to depict microvasculature by means of susceptibility effects within the veins allow for the accurate detection, grading, and monitoring of brain tumors. This imaging modality can also detect changes in blood flow to monitor stroke recovery and reveal specific subtypes of vascular malformations. In addition, small punctate lesions can be demonstrated with SWI, suggesting diffuse axonal injury, and the location of these lesions can help predict neurological outcome in patients. This imaging technique is also beneficial for applications in functional neurosurgery given its ability to clearly depict and differentiate deep midbrain nuclei and close submillimeter veins, both of which are necessary for presurgical planning of deep brain stimulation. By exploiting the magnetic susceptibilities of substances within the body, such as deoxyhemoglobin, calcium, and iron, SWI can clearly visualize the vasculature and hemorrhagic components even without the use of contrast agents. The high sensitivity of SWI relative to other imaging techniques in showing tumor vasculature and microhemorrhages suggests that it is an effective imaging modality that provides additional information not shown using conventional MRI. Despite SWI's clinical advantages, its implementation in MRI protocols is still far from consistent in clinical usage. To develop a deeper appreciation for SWI, the authors here review the clinical applications in 4 major fields of neurosurgery: neurooncology, vascular neurosurgery, neurotraumatology, and functional neurosurgery. Finally, they address the limitations of and future perspectives on SWI in neurosurgery.

  3. Simulation and resident education in spinal neurosurgery.

    PubMed

    Bohm, Parker E; Arnold, Paul M

    2015-01-01

    A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery. We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use. A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported. The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education.

  4. Simulation and resident education in spinal neurosurgery

    PubMed Central

    Bohm, Parker E.; Arnold, Paul M.

    2015-01-01

    Background: A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery. Methods: We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use. Results: A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported. Conclusion: The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education. PMID:25745588

  5. Landmark papers in cerebrovascular neurosurgery 2015.

    PubMed

    Moore, Justin M; Griessenauer, Christoph J; Gupta, Raghav; Adeeb, Nimer; Patel, Apar S; Ogilvy, Christopher S; Thomas, Ajith J

    2016-09-01

    The management of cerebrovascular disease has advanced considerably in 2015. Five randomized control trials have firmly established the role of endovascular thrombectomy for ischemic strokes due to large vessel occlusion. The randomized trial of intraarterial treatment for acute ischemic stroke (MR CLEAN) (Berkhemer et al. NEJM 2015;372:11-20) was the first of a series on the topic. There was a total of 5 randomized controlled trials published showing benefit in terms of functional outcomes at 90days for mechanical thrombectomy including the Endovascular Therapy for Ischemic stroke with perfusion-imaging selection (EXTEND IA) (Campbell et al. NEJM 2015;372:1009-18), the Randomized assessment of rapid endovascular treatment of ischemic stroke (ESCAPE) (Goyal et al. NEJM 2015;372:1019-30) trials, the stent-retriever thrombectomy after IV t-PA is t-PA alone in stroke (SWIFT-PRIME) (Saver et al. NEJM 2015;372:2285-95), and the thrombectomy within 8h after symptom onset in Ischemic stroke (REVASCAT) trial (Jovin et al. NEJM 2015; 372:2296-306). Six-year results from randomized controlled Barrow Ruptured Aneurysm Trial (BRAT) found no significant difference in functional outcomes in patients ruptured aneurysms treated surgically clippings versus endovascular treatment (Spetzler et al. JNS 2015;123:609-17. The 10-year results of the International Subarachnoid Aneurysm trial (ISAT) reported similar mortality rates and good functional outcomes between clipped and coiled patients (Molyneux et al. Lancet 2015;385:691-7). We also discuss the impact of genome wide sequencing studies in familial aneurysms, the largest publication on stent assisted coiling and flow diverter for aneurysms and noteworthy papers relevant to Moyamoya and cavernous malformations (Yang et al. Neurosurgery 2015;77:241-7). Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Fetal neurosurgery: current state of the art

    PubMed Central

    Saadai, Payam; Runyon, Timothy; Farmer, Diana L

    2011-01-01

    Congenital CNS abnormalities have been targets for prenatal intervention since the founding of fetal surgery 30 years ago, but with historically variable results. Open fetal neurosurgery for myelomenigocele has demonstrated the most promising results of any CNS malformation. Improvements in the understanding of congenital diseases and in fetal surgical techniques have reopened the door to applying fetal surgery to other congenital CNS abnormalities. Advances in gene therapy, bioengineering and neonatal neuroprotection will aid in the future expansion of fetal neurosurgery to other CNS disorders. PMID:21709818

  7. From atom to brain: applications of molecular imaging to neurosurgery.

    PubMed

    Taghva, Alexander; Khalessi, Alexander A; Kim, Paul E; Liu, Charles Y; Apuzzo, Michael L J

    2010-05-01

    Molecular imaging is a field born out of the happy marriage of molecular biology and radiology. The first installment of this two-part series on molecular imaging demonstrated basic principles for practitioners in the field of the neurosciences. This installment seeks to provide some illustrative examples, insights, and specific applications to the neurosciences. The fields of functional neurosurgery including the treatment of neuropsychiatric disorders, novel treatments and imaging of tumors, neuroregenerative medicine, and nanotechnology in vascular disorders are covered. Finally, we give some parting thoughts on the future of molecular imaging, including advances in the imaging of neurodegenerative disorders. Published by Elsevier Inc.

  8. [From stone trephine to robots, 5000 years of neurosurgery].

    PubMed

    Reinhardt, H F

    1990-01-16

    Only a century has elapsed since the first serious surgical interventions on the human brain were undertaken; man has however sought to understand its structure and function for several thousand years in order to reach therapeutic consequences. A few highlights of brain research and neurosurgery from the neolithic to current times are described along with the prevailing views and technologies. Parallels are drawn with examples from clock making. An outlook to computer aided surgery (CAS) combining modern imaging techniques with data processing and technical operative innovation is given.

  9. Quantum computing: a prime modality in neurosurgery's future.

    PubMed

    Lee, Brian; Liu, Charles Y; Apuzzo, Michael L J

    2012-11-01

    With each significant development in the field of neurosurgery, our dependence on computers, small and large, has continuously increased. From something as mundane as bipolar cautery to sophisticated intraoperative navigation with real-time magnetic resonance imaging-assisted surgical guidance, both technologies, however simple or complex, require computational processing power to function. The next frontier for neurosurgery involves developing a greater understanding of the brain and furthering our capabilities as surgeons to directly affect brain circuitry and function. This has come in the form of implantable devices that can electronically and nondestructively influence the cortex and nuclei with the purpose of restoring neuronal function and improving quality of life. We are now transitioning from devices that are turned on and left alone, such as vagus nerve stimulators and deep brain stimulators, to "smart" devices that can listen and react to the body as the situation may dictate. The development of quantum computers and their potential to be thousands, if not millions, of times faster than current "classical" computers, will significantly affect the neurosciences, especially the field of neurorehabilitation and neuromodulation. Quantum computers may advance our understanding of the neural code and, in turn, better develop and program implantable neural devices. When quantum computers reach the point where we can actually implant such devices in patients, the possibilities of what can be done to interface and restore neural function will be limitless. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. TECHNOLOGICAL INNOVATION IN NEUROSURGERY: A QUANTITATIVE STUDY

    PubMed Central

    Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

    2015-01-01

    Object Technological innovation within healthcare may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technologically intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical technique. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation respectively. Methods A patent database was searched between 1960 and 2010 using the search terms “neurosurgeon” OR “neurosurgical” OR “neurosurgery”. The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top performing technology cluster was then selected as an exemplar for more detailed analysis of individual patents. Results In all, 11,672 patents and 208,203 publications relating to neurosurgery were identified. The top performing technology clusters over the 50 years were: image guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes and endoscopes. Image guidance and neuromodulation devices demonstrated a highly correlated rapid rise in patents and publications, suggesting they are areas of technology expansion. In-depth analysis of neuromodulation patents revealed that the majority of high performing patents were related to Deep Brain Stimulation (DBS). Conclusions Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery. PMID:25699414

  11. Neurosurgery, "neurospine," and neuroscience: a vital synergy?

    PubMed

    Nowitzke, Adrian

    2008-10-01

    A fundamental dilemma that faces both neurosurgery in general and the subspecialty field of spine surgery is the question of whether those who trained in the former and now work in the latter should maintain their links with their origins and remain under the broader umbrella of neurosurgery, or whether they should develop their own organizational structure and identity separate from organized neurosurgery. This challenge raises many questions with respect to future potential for growth and development, professional identity, and collegiality. This paper is an edited version of an invited speech to the 2007 Annual Meeting of the Joint Section on Disorders of the Spine and Peripheral Nerves. It uses the concept of synergy to review relevant history and explore possible future options for neurosurgery, neurospine, and neuroscience. An example from medical politics is used to illustrate the importance of perspective in approaching these questions, and examples of current therapeutic cutting-edge endeavors highlight the need for team-based behavior that takes a broad view. The premise of the paper is that while individual and specialty aspirations need to be acknowledged, considered, and managed, the results from truly working together will be greater than the sum of the individual efforts-synergy.

  12. Modernity and the emerging futurism in neurosurgery.

    PubMed

    Apuzzo, M L

    2000-03-01

    This article discusses the emergence of neurosurgery in its 'modern' form during the second half of the 20th century and presents the apertures to the 21st century that are apparent in establishing an evolving futurism in the field. Factors of primary positive impetus and challenges are discussed. Copyright 2000 Harcourt Publishers Ltd.

  13. Use of ADCON in neurosurgery: preclinical review.

    PubMed

    Lo, H; Frederickson, R C

    1999-01-01

    ADCON-L and ADCON-T/N are two bioabsorbable adhesion barrier gels designed to inhibit post-operative fibrosis around the dura and nerve structure. Two ADCON products were evaluated in animal models emulating their use in neurosurgery. In all studies ADCON-L and ADCON-T/N were safe and effective barriers to post-operative peridural and perineural fibrosis.

  14. Experimental measurement of the Melnikov function

    NASA Astrophysics Data System (ADS)

    Meunier, Patrice; Huck, Peter; Nobili, Clément; Villermaux, Emmanuel

    2015-07-01

    We study the transport properties of a genuine two-dimensional flow with a large mean velocity perturbed periodically in time by means of an original experimental technique. The flow generated by the co-rotation of two cylinders is both stratified with a linear density gradient using salted water and viscous in order to prevent Ekman pumping and centrifugal instabilities. Thus, the mean flow contains a hyperbolic point with a homoclinic streamline, which we perturb periodically by an extra oscillation. A blob of scalar injected close to the stagnation point contracts on the stable manifold and stretches in the unstable direction. The distance between the stable and the unstable manifolds is measured as the distance between the maximum and the minimum of the dye undulating pattern and is recorded as a function of the perturbation frequency. This distance, also called the Melnikov function, presents a maximum when the residence time of a fluid particle in the mean flow is about half a perturbation period. This resonance criterion is recovered with good quantitative agreement by the theoretical prediction of the Melnikov function computed for this flow.

  15. A relational database in neurosurgery.

    PubMed

    Sicurello, F; Marchetti, M R; Cazzaniga, P

    1995-01-01

    This paper describes teh automatic procedure for a clinical record management in a Neurosurgery ward. The automated record allows the storage, querying and effective management of clinical data. This is useful during the patient stay and also for data processing and analysis aiming at clinical research and statistical studies. The clinical record is problem-oriented. It contains a minimum data set regarding every patient and a data set which is defined by a classification nomenclature (using an inner protocol). The main parts of the clinical record are the following tables: PERSONAL DATA: contains the fields relating to personal and admission data of the patient. The compilation of some fields is compulsory because they serve as input for the automated discharge letter. This table is used as an identifier for patient retrieval. composed of five different tables according to the kind of data. They are: familiar anamnesis, physiological anamnesis, past and next pathology anamnesis, and trauma anamnesis. GENERAL OBJECTIVITY: contains the general physical information of a patient. The field hold default values, which quickens the compilation and assures the recording of normal values. NEUROLOGICAL EXAMINATION: contains information about the neurological status of the patient. Also in this table, ther are default values in the fields. COMA: contains standardized ata and classifications. The multiple choices are automated and driven and belong to homogeneous classes. SURGICAL OPERATIONS: the information recording is made defining the general kind of operation and then defining the peculiar kind of operation. INSTRUMENTAL EXAMINATIONS: some examination results are recorded in a free structure, while other ones (TAC, etc.) follow codified structure. In order to identify a pathology by means of TAC, it is enough to record three values corresponding to three variables. THis classification fully describes a lot of neurosurgical pathologies. DISCHARGE: contains conclusions

  16. Infrared lidar overlap function: an experimental determination.

    PubMed

    Guerrero-Rascado, Juan Luis; Costa, Maria João; Bortoli, Daniele; Silva, Ana Maria; Lyamani, Hassan; Alados-Arboledas, Lucas

    2010-09-13

    The most recent works demonstrate that the lidar overlap function, which describes the overlap between the laser beam and the receiver field of view, can be determined experimentally for the 355 and 532 nm channels using Raman signals. Nevertheless, the Raman channels cannot be used to determine the lidar overlap for the infrared channel (1064 nm) because of their low intensity. In addition, many Raman lidar systems only provide inelastic signals with reasonable signal-to-noise ratio at nighttime. In view of this fact, this work presents a modification of that method, based on the comparison of attenuated backscatter profiles derived from lidar and ceilometer, to retrieve the overlap function for the lidar infrared channel. Similarly to the Raman overlap method, the approach presented here allows to derive the overlap correction without an explicit knowledge of all system parameters. The application of the proposed methodology will improve the potential of Raman lidars to investigate the aerosol microphysical properties in the planetary boundary layer, extending the information of 1064 nm backscatter profiles to the ground and allowing the retrieval of microphysical properties practically close to the surface.

  17. Neuromuscular Functions on Experimental Acute Methanol Intoxication

    PubMed Central

    Moral, Ali Reşat; Çankayalı, İlkin; Sergin, Demet; Boyacılar, Özden

    2015-01-01

    Objective The incidence of accidental or suicidal ingestion of methyl alcohol is high and methyl alcohol intoxication has high mortality. Methyl alcohol intoxication causes severe neurological sequelae and appears to be a significant problem. Methyl alcohol causes acute metabolic acidosis, optic neuropathy leading to permanent blindness, respiratory failure, circulatory failure and death. It is metabolised in the liver, and its metabolite formic acid has direct toxic effects, causing oxidative stress, mitochondrial damage and increased lipid peroxidation associated with the mechanism of neurotoxicity. Methanol is known to cause acute toxicity of the central nervous system; however, the effects on peripheral neuromuscular transmission are unknown. In our study, we aimed to investigate the electrophysiological effects of experimentally induced acute methanol intoxication on neuromuscular transmission in the early period (first 24 h). Methods After approval by the Animal Experiment Ethics Committee of Ege University, the study was carried out on 10 Wistar rats, each weighing about 200 g. During electrophysiological recordings and orogastric tube insertion, the rats were anaesthetised using intra-peritoneal (IP) injection of ketamine 100 mg kg−1 and IP injection of xylazine 10 mg kg−1. The rats were given 3 g kg−1 methyl alcohol by the orogastric tube. Electrophysiological measurements from the gastrocnemius muscle were compared with baseline. Results Latency measurements before and 24 h after methanol injection were 0.81±0.11 ms and 0.76±0.12 ms, respectively. CMAP amplitude measurements before and 24 h after methanol injection were 9.85±0.98 mV and 9.99±0.40 mV, respectively. CMAP duration measurements before and 24 h after methanol injection were 9.86±0.03 ms and 9.86±0.045 ms, respectively. Conclusion It was concluded that experimental methanol intoxication in the acute phase (first 24 h) did not affect neuromuscular function. PMID:27366524

  18. Experimental Fracture Measurements of Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Carpenter, Ray Douglas

    The primary objective of this research was to extend established fracture toughness testing methods to a new class of engineering materials known as functionally graded materials (FGMs). Secondary goals were to compare experimental results to those predicted by finite element models and to provide fracture test results as feedback toward optimizing processing parameters for the in-house synthesis of a MoSi2/SiC FGM. Preliminary experiments were performed on commercially pure (CP) Ti and uniform axial tensile tests resulted in mechanical property data including yield strength, 268 MPa, ultimate tensile strength, 470 MPa and Young's modulus, 110 GPa. Results from 3-point bending fracture experiments on CP Ti demonstrated rising R-curve behavior and experimentally determined JQ fracture toughness values ranged between 153 N/mm and 254 N/mm. Similar experimental protocols were used for fracture experiments on a 7- layered Ti/TiB FGM material obtained from Cercom in Vista, California. A novel technique for pre-cracking in reverse 4-point bending was developed for this ductile/brittle FGM material. Fracture test results exhibited rising R-curve behavior and estimated JQ fracture toughness values ranged from 0.49 N/mm to 2.63 N/mm. A 5- layered MoSi2/SiC FGM was synthesized using spark plasma sintering (SPS). Samples of this material were fracture tested and the results again exhibited a rising R-curve with KIC fracture toughness values ranging from 2.7 MPa-m1/2 to 6.0 MPa-m1/2. Finite Element Models predicted rising R-curve behavior for both of the FGM materials tested. Model results were in close agreement for the brittle MoSi2/SiC FGM. For the relatively more ductile Ti/TiB material, results were in close agreement at short crack lengths but diverged at longer crack lengths because the models accounted for fracture toughening mechanisms at the crack tip but not those acting in the crack wake.

  19. The history of neurosurgery in Bolivia and pediatric neurosurgery in Santa Cruz de la Sierra.

    PubMed

    Dabdoub, Carlos F; Dabdoub, Carlos B

    2013-09-25

    The practice of neurosurgery in Bolivia began thousands of years ago with skull trepanation. This procedure dates from the earliest period of the Tiwanaku culture, a preInca civilization. Neurosurgical development in Bolivia has its origins in the late 19(th) century and can be divided in two stages. At the beginning, before the advent of neurosurgery as a discipline, some general surgeons performed procedures on the skull and brain. Formal neurosurgery in Bolivia was developed with the arrival of neurosurgeons trained in the United States and some countries of South America. The Bolivian Neurosurgical Society was created in 1975. Nowadays, our national society has 74 members. It is affiliated with the World Federation of Neurosurgical Societies and the Latin American Federation of Neurosurgical Societies. Presently, neurosurgery in Bolivia is similar to that seen in developed countries. In this sense, government programs should dedicate more financial support to establish specialized healthcare centers where the management of complex central nervous system lesions could be offered. In contrast, we believe that encouraging the local training of young neurosurgeons is one of the most important factors in the development of neurosurgery in Bolivia or any other country.

  20. The history of neurosurgery in Bolivia and pediatric neurosurgery in Santa Cruz de la Sierra

    PubMed Central

    Dabdoub, Carlos F.; Dabdoub, Carlos B.

    2013-01-01

    The practice of neurosurgery in Bolivia began thousands of years ago with skull trepanation. This procedure dates from the earliest period of the Tiwanaku culture, a preInca civilization. Neurosurgical development in Bolivia has its origins in the late 19th century and can be divided in two stages. At the beginning, before the advent of neurosurgery as a discipline, some general surgeons performed procedures on the skull and brain. Formal neurosurgery in Bolivia was developed with the arrival of neurosurgeons trained in the United States and some countries of South America. The Bolivian Neurosurgical Society was created in 1975. Nowadays, our national society has 74 members. It is affiliated with the World Federation of Neurosurgical Societies and the Latin American Federation of Neurosurgical Societies. Presently, neurosurgery in Bolivia is similar to that seen in developed countries. In this sense, government programs should dedicate more financial support to establish specialized healthcare centers where the management of complex central nervous system lesions could be offered. In contrast, we believe that encouraging the local training of young neurosurgeons is one of the most important factors in the development of neurosurgery in Bolivia or any other country. PMID:24232440

  1. Socioeconomic issues of United States military neurosurgery.

    PubMed

    Moquin, Ross R; Ecklund, James M

    2002-04-15

    Although the practice of neurosurgery in the United States (US) Armed Forces is in many ways similar to the civilian practice of neurosurgery, there are many differences as well. The unique challenges, duties, and opportunities US military neurosurgeons are given, both in peacetime and in times of conflict, are discussed, as are pathways for entering into service. The advantages of military service for neurosurgeons include sponsored training, decreased direct exposure to tort actions, little involvement with third-party payers, significant opportunities for travel, and military specific experiences. The most appealing aspect of military practice is serving fellow members of the US Armed Forces. Disadvantages include the extreme gap between the military and civilian pay scales, lack of support personnel, and in some areas low surgery-related case volume. The greatest concern faced by the military neurosurgical community is the failure to retain experienced neurosurgeons after their obligated service time has been completed, for which several possible solutions are described. It is hoped that future changes will make the practice of military neurosurgery attractive enough so that it will be seen as a career in itself and not an obligation to endure before starting practice in the "real world."

  2. Neurosurgery: A profession or a technical trade?

    PubMed

    Watts, Clark

    2014-01-01

    The American Association of Neurological Surgeons (AANS), 11 years ago converted its Internal Revenue Code (IRC) tax status from a 501 (c) (3) to a 501 (c) (6) entity. By doing so, the professional medical association, now a trade association, was able to more aggressively lobby, support political campaigns, and pursue business opportunities for its members. In the following decade, major changes were seen in the practice of neurosurgery, especially as it relates to spine surgery. With the majority of neurosurgeons limiting themselves to a spine practice, an increased number of spinal procedures, most noted in the Medicare population, was recorded. For example, a 15-fold increase in complex spinal fusions for spinal stenosis was seen between 2002 and 2007. While the basis for this increase was not readily apparent, it was associated with a reduction in reimbursement per case of about 50%, fueling the belief that the increase in complexity of surgery permitted recovery of fees in complex cases to off-set the loss of reimbursement for simpler cases. Considering the growth of spinal surgery within neurosurgery, and decrease funding for spine surgery, in the future there may be too many surgeons chasing too few dollars. There appears to be within neurosurgery a crisis developing where future manpower projections do not realistically match future anticipated specialty funding.

  3. Molecular neurosurgery: vectors and vector delivery strategies.

    PubMed

    White, Edward

    2012-12-01

    Molecular neurosurgery involves the use of vector-mediated gene therapy and gene knockdown to manipulate in vivo gene expression for the treatment of neurological diseases. These techniques have the potential to revolutionise the practice of neurosurgery. However, significant challenges remain to be overcome before these techniques enter routine clinical practice. These challenges have been the subject of intensive research in recent years and include the development of strategies to facilitate effective vector delivery to the brain and the development of both viral and non-viral vectors that are capable of efficient cell transduction without excessive toxicity. This review provides an update on the practice of molecular neurosurgery with particular focus on the practical neurosurgical aspects of vector delivery to the brain. In addition, an introduction to the key vectors employed in clinical trials and a brief overview of previous gene therapy clinical trials is provided. Finally, key areas for future research aimed at increasing the likelihood of the successful translation of gene therapy into clinical trials are highlighted.

  4. Photodynamic application in neurosurgery: present and future

    NASA Astrophysics Data System (ADS)

    Kostron, Herwig

    2009-06-01

    Photodynamic techniques such as photodynamic diagnosis (PDD), fluorescence guided tumor resection (FGR) and photodynamic therapy (PDT) are currently undergoing intensive clinical investigations as adjunctive treatment for malignant brain tumours. This review provides an overview on the current clinical data and trials as well as on photosensitisers, technical developments and indications for photodynamic application in Neurosurgery. Furthermore new developments and clinical significance of FGR for neurosurgery will be discussed. Over 1000 patients were enrolled in various clinical phase I/II trials for PDT for malignant brain tumours. Despite various treatment protocols, variation of photosensitisers and light dose there is a clear trend towards prolonging median survival after one single PDT as compared to conventional therapeutic modalities. The median survival after PDT for primary glioblastoma multiforme WHO IV was 19 months and for recurrent GBM 9 months as compared to standard convential treatment which is 15 months and 3 months, respectively. FGR in combination with adjunctive radiation was significantly superior to standard surgical resection followed by radiation. The combination of FGR/PDD and intraoperative PDT increased significantly survival in recurrent glioblastoma patients. The combination of PDD/ FGR and PDT offers an exciting approach to the treatment of malignant brain tumours "to see and to treat." PDT was generally well tolerated and side effects consisted of occasionally increased intracranial pressure and prolonged skin sensitivity against direct sunlight. This review covers the current available data and draws the future potential of PDD and PDT for its application in neurosurgery.

  5. [The origins of the French neurosurgery].

    PubMed

    Brunon, J

    2016-06-01

    Modern French neurosurgery starts at the beginning of the XXth century under the motivation of Joseph Babinski. He submitted his patients to Thierry de Martel who had learned this new specialized area of medicine with H. Cushing in the États-Unis and V. Horsey in Great Britain. His first successfully treated case of an intracranial tumor was published in 1909. But the true founding father was Clovis Vincent, initially a neurologist and collaborator of de Martel, who became the first chairman in 1933 of the neurosurgical department at the Pitié hospital of Paris and the first professor of neurosurgery in 1938. After the Second World War, many departments were created outside of Paris. Neurosurgery was definitively recognized as a specialized area in medicine in 1948. Currently, more than 400 neurosurgeons work in France. Because I had the very great privilege to be present at the birth of this society in 1970 and to still be in contact with some of the second and third generation of French neurosurgeons who led it to its high international recognition, the Chairman of the French Neurosurgical Society asked me to write this short historical vignette.

  6. Neurosurgery: A profession or a technical trade?

    PubMed Central

    Watts, Clark

    2014-01-01

    The American Association of Neurological Surgeons (AANS), 11 years ago converted its Internal Revenue Code (IRC) tax status from a 501 (c) (3) to a 501 (c) (6) entity. By doing so, the professional medical association, now a trade association, was able to more aggressively lobby, support political campaigns, and pursue business opportunities for its members. In the following decade, major changes were seen in the practice of neurosurgery, especially as it relates to spine surgery. With the majority of neurosurgeons limiting themselves to a spine practice, an increased number of spinal procedures, most noted in the Medicare population, was recorded. For example, a 15-fold increase in complex spinal fusions for spinal stenosis was seen between 2002 and 2007. While the basis for this increase was not readily apparent, it was associated with a reduction in reimbursement per case of about 50%, fueling the belief that the increase in complexity of surgery permitted recovery of fees in complex cases to off-set the loss of reimbursement for simpler cases. Considering the growth of spinal surgery within neurosurgery, and decrease funding for spine surgery, in the future there may be too many surgeons chasing too few dollars. There appears to be within neurosurgery a crisis developing where future manpower projections do not realistically match future anticipated specialty funding. PMID:25558426

  7. Neurosurgery in Lebanon: History, Development, and Future Challenges.

    PubMed

    Fares, Youssef; Fares, Jawad

    2017-03-01

    Lebanon stands out as the one of the first countries in the Middle East and the Arab world to practice the medical specialty of neurosurgery. In addition, Lebanon has one of the best reputations for neurosurgery in this region. This article documents the history and current status of Lebanese neurosurgery. Residency and fellowship trainings are also highlighted, and political, socioeconomic, and academic challenges for the future of the profession are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Art, passion, and neurosurgery: the role of the Society of Neurological Surgeons in academic neurosurgery.

    PubMed

    Dempsey, Robert J

    2011-11-01

    Neurosurgery is at a crossroads in a time of economic uncertainty. It is also a time of remarkable potential for innovation resulting in dramatic improvement in the way neurosurgeons care for patients and the quality of outcomes. Analysis of this key time point of neurosurgical history is drawn from reflections for a presidential address to the Society of Neurological Surgeons. It is the author's opinion that the best of academic neurosurgery must and will accept this challenge by developing not only the research but also the creativity and art of what neurosurgeons do for maximal patient benefit in research, educational, and clinical missions.

  9. Laser Nano-Neurosurgery from Gentle Manipulation to Nano-Incision of Neuronal Cells and Scaffolds: An Advanced Neurotechnology Tool.

    PubMed

    Soloperto, Alessandro; Palazzolo, Gemma; Tsushima, Hanako; Chieregatti, Evelina; Vassalli, Massimo; Difato, Francesco

    2016-01-01

    Current optical approaches are progressing far beyond the scope of monitoring the structure and function of living matter, and they are becoming widely recognized as extremely precise, minimally-invasive, contact-free handling tools. Laser manipulation of living tissues, single cells, or even single-molecules is becoming a well-established methodology, thus founding the onset of new experimental paradigms and research fields. Indeed, a tightly focused pulsed laser source permits complex tasks such as developing engineered bioscaffolds, applying calibrated forces, transfecting, stimulating, or even ablating single cells with subcellular precision, and operating intracellular surgical protocols at the level of single organelles. In the present review, we report the state of the art of laser manipulation in neuroscience, to inspire future applications of light-assisted tools in nano-neurosurgery.

  10. Laser Nano-Neurosurgery from Gentle Manipulation to Nano-Incision of Neuronal Cells and Scaffolds: An Advanced Neurotechnology Tool

    PubMed Central

    Soloperto, Alessandro; Palazzolo, Gemma; Tsushima, Hanako; Chieregatti, Evelina; Vassalli, Massimo; Difato, Francesco

    2016-01-01

    Current optical approaches are progressing far beyond the scope of monitoring the structure and function of living matter, and they are becoming widely recognized as extremely precise, minimally-invasive, contact-free handling tools. Laser manipulation of living tissues, single cells, or even single-molecules is becoming a well-established methodology, thus founding the onset of new experimental paradigms and research fields. Indeed, a tightly focused pulsed laser source permits complex tasks such as developing engineered bioscaffolds, applying calibrated forces, transfecting, stimulating, or even ablating single cells with subcellular precision, and operating intracellular surgical protocols at the level of single organelles. In the present review, we report the state of the art of laser manipulation in neuroscience, to inspire future applications of light-assisted tools in nano-neurosurgery. PMID:27013962

  11. [Perceived quality in hospitals of the Andalusia Healthcare System. The case of neurosurgery departments].

    PubMed

    Cordero Tous, N; Horcajadas Almansa, Á; Bermúdez González, G J; Tous Zamora, D

    2014-01-01

    To analyse the characteristics of the perceived quality in hospitals of the Andalusia healthcare system and compare this with that in Andalusian Neurosurgery departments. Randomised surveys, adjusted for working age, were performed in Andalusia using a telephone questionnaire based on the SERVQUAL model with the appropriate modification, with the subsequent selection of a subgroup associated with neurosurgery. Perceived quality was classified as; technical, functional and infrastructure quality. The overall satisfaction was 76.3%. Frequency analysis found that variables related to the technical quality (good doctors, successful operations, trained staff, etc.) obtained more favourable outcomes. Those related to time (wait, consulting, organizing schedules) obtained worse outcomes. The care of families variables obtained poor results. There was no difference between the overall Andalusian healthcare system and neurosurgery departments. In the mean analysis, women and older people gave more favourable responses, especially for variables related to infrastructure quality. In the "cluster" analysis, there were more favourable responses by elderly people, with no differences in gender (P<.009). There is no difference in perceived quality between the Andalusian healthcare system overall and neurosurgery departments. The perceived quality of the Andalusian healthcare system is higher in the elderly people. The analysis of perceived quality is useful for promoting projects to improve clinical management. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

  12. Application of Predictive Nursing Reduces Psychiatric Complications in ICU Patients after Neurosurgery

    PubMed Central

    LIU, Qiong; ZHU, Hui

    2016-01-01

    Background: Our aim was to investigate the effects of clinical application of perioperative predictive nursing on reducing psychiatric complications in Intensive Care Unit (ICU) patients after neurosurgery. Methods: A total of 129 patients who underwent neurosurgery and received intensive care were enrolled in our study from February 2013 to February 2014. These patients were divided into two groups: the experimental group (n=68) receiving predictive nursing before and after operation, and the control group (n=61) with general nursing. Clinical data including length of ICU stay, duration of the patients’ psychiatric symptoms, form and incidence of adverse events, and patient satisfaction ratings were recorded, and their differences between the two groups were analyzed. Results: The duration of psychiatric symptoms and the length of ICU stay for patients in the experimental group were significantly shorter than those in the control group (P<0.05). The incidence of adverse events and psychiatric symptoms, such as sensory and intuition disturbance, thought disturbance, emotional disorder, and consciousness disorder, in the experimental group was significantly lower than that in the control group (P<0.05). Patient satisfaction ratings were significantly higher in the experimental group than those in the control group (P<0.05). Conclusion: Application of predictive nursing on ICU patients who undergo neurosurgery could effectively reduce the incidence of psychiatric symptoms as well as other adverse events. Our study provided clinical evidences to encourage predictive nursing in routine settings for patients in critical conditions. PMID:27252916

  13. Graph theory analysis of complex brain networks: new concepts in brain mapping applied to neurosurgery.

    PubMed

    Hart, Michael G; Ypma, Rolf J F; Romero-Garcia, Rafael; Price, Stephen J; Suckling, John

    2016-06-01

    Neuroanatomy has entered a new era, culminating in the search for the connectome, otherwise known as the brain's wiring diagram. While this approach has led to landmark discoveries in neuroscience, potential neurosurgical applications and collaborations have been lagging. In this article, the authors describe the ideas and concepts behind the connectome and its analysis with graph theory. Following this they then describe how to form a connectome using resting state functional MRI data as an example. Next they highlight selected insights into healthy brain function that have been derived from connectome analysis and illustrate how studies into normal development, cognitive function, and the effects of synthetic lesioning can be relevant to neurosurgery. Finally, they provide a précis of early applications of the connectome and related techniques to traumatic brain injury, functional neurosurgery, and neurooncology.

  14. Smartphone use in neurosurgery? APP-solutely!

    PubMed Central

    Zaki, Michael; Drazin, Doniel

    2014-01-01

    Background: A number of smartphone medical apps have recently emerged that may be helpful for the neurosurgical patient, practitioner, and trainee. This study aims to review the current neurosurgery-focused apps available for the iPhone, iPad, and Android platforms as of December 2013. Methods: Two of the most popular smartphone app stores (Apple Store and Android Google Play Store) were surveyed for neurosurgery-focused apps in December 2013. Search results were categorized based on their description page. Data were collected on price, rating, app release date, target audience, and medical professional involvement in app design. A review of the top apps in each category was performed. Results: The search resulted in 111 unique apps, divided into these 7 categories: 16 (14%) clinical tools, 17 (15%) conference adjunct, 27 (24%) education, 18 (16%) literature, 15 (14%) marketing, 10 (9%) patient information, and 8 (7%) reference. The average cost of paid apps was $23.06 (range: $0.99-89.99). Out of the 111 apps, 71 (64%) were free, 48 (43%) had reviews, and 14 (13%) had more than 10 reviews. Seventy-three (66%) apps showed evidence of medical professional involvement. The number of apps being released every year has been increasing since 2009. Conclusions: There are a number of neurosurgery-themed apps available to all audiences. There was a lack of patient information apps for nonspinal procedures. Most apps did not have enough reviews to evaluate their quality. There was also a lack of oversight to validate the accuracy of medical information provided in these apps. PMID:25101208

  15. Smartphone use in neurosurgery? APP-solutely!

    PubMed

    Zaki, Michael; Drazin, Doniel

    2014-01-01

    A number of smartphone medical apps have recently emerged that may be helpful for the neurosurgical patient, practitioner, and trainee. This study aims to review the current neurosurgery-focused apps available for the iPhone, iPad, and Android platforms as of December 2013. Two of the most popular smartphone app stores (Apple Store and Android Google Play Store) were surveyed for neurosurgery-focused apps in December 2013. Search results were categorized based on their description page. Data were collected on price, rating, app release date, target audience, and medical professional involvement in app design. A review of the top apps in each category was performed. The search resulted in 111 unique apps, divided into these 7 categories: 16 (14%) clinical tools, 17 (15%) conference adjunct, 27 (24%) education, 18 (16%) literature, 15 (14%) marketing, 10 (9%) patient information, and 8 (7%) reference. The average cost of paid apps was $23.06 (range: $0.99-89.99). Out of the 111 apps, 71 (64%) were free, 48 (43%) had reviews, and 14 (13%) had more than 10 reviews. Seventy-three (66%) apps showed evidence of medical professional involvement. The number of apps being released every year has been increasing since 2009. There are a number of neurosurgery-themed apps available to all audiences. There was a lack of patient information apps for nonspinal procedures. Most apps did not have enough reviews to evaluate their quality. There was also a lack of oversight to validate the accuracy of medical information provided in these apps.

  16. Mythological and Prehistorical Origins of Neurosurgery.

    PubMed

    Nanda, Anil; Filis, Andreas; Kalakoti, Piyush

    2016-05-01

    Mythology has a cultural appeal, and the description of some neurosurgical procedures in the Hindu, Greek, Egyptian, and Chinese mythology has a bearing to the origins of our professions. The traces to some of our modern-day practices also can be linked back to the ancient prehistoric eras of the Siberian, Persian, and the Andean region. In this historical perspective, we briefly dwell into individual accounts through the prism of different cultures to highlight the development of neurosurgery in mythology and prehistoric era.

  17. Genealogy of training in vascular neurosurgery.

    PubMed

    Chowdhry, Shakeel A; Spetzler, Robert F

    2014-02-01

    Remarkable advances and changes in the landscape of neurovascular disease have occurred recently. Concurrently, a paradigm shift in training and resident education is underway. This crossroad of unique opportunities and pressures necessitates creative change in the training of future vascular neurosurgeons to allow incorporation of surgical advances, new technology, and supplementary treatment modalities in a setting of reduced work hours and increased public scrutiny. This article discusses the changing landscape in neurovascular disease treatment, followed by the recent changes in resident training, and concludes with our view of the future of training in vascular neurosurgery.

  18. Current Status and Future Prospect of Endovascular Neurosurgery

    PubMed Central

    Jeon, Young Il

    2008-01-01

    Recently, due to the evolution of technology, the field of neurosurgery is receiving spotlight. In particular endovascular neurosurgery has gained a great interest along with the advancement of the modern neurosurgery. The most remarkable advances were made in embolization of the cerebral aneurysms, arteriovenous malformations and intracranial stenosis during the past 10 years. These advances will further change the role of neurosurgeons in treating cerebrovascular disease. Because interventional neuroradiologists have performed most of procedures in the past, neurosurgeons have been deprived of chances to learn endovascular procedure. This article discusses the development of technological aspect of endovascular neurosurgery in chronological order. By understanding the history and current status of the endovascular surgery, the future of neurosurgery will be promising. PMID:19096608

  19. The functions of language: an experimental study.

    PubMed

    Redhead, Gina; Dunbar, R I M

    2013-08-14

    We test between four separate hypotheses (social gossip, social contracts, mate advertising and factual information exchange) for the function(s) of language using a recall paradigm. Subjects recalled the social content of stories (irrespective of whether this concerned social behavior, defection or romantic events) significantly better than they did ecological information. Recall rates were no better on ecological stories if they involved flamboyant language, suggesting that, if true, Miller's "Scheherazade effect" may not be independent of content. One interpretation of these results might be that language evolved as an all-purpose social tool, and perhaps acquired specialist functions (sexual advertising, contract formation, information exchange) at a later date through conventional evolutionary windows of opportunity.

  20. Minimalism in Art, Medical Science and Neurosurgery.

    PubMed

    Ökten, Ali İhsan

    2016-12-21

    The word ''minimalism'' is a word derived from French the word ''minimum''. Whereas the lexical meaning of minimum is ''the least or the smallest quantity necessary for something'', its expression in mathematics can be described as ''the lowest step a variable number can descend, least, minimal''. Minimalism, which advocates an extreme simplicity of the artistic form, is a current in modern art and music whose origins go to 1960s and which features simplicity and objectivity. Although art, science and philosophy are different disciplines, they support each other from time to time, sometimes they intertwine and sometimes they copy each other. A periodic schools or teaching in one of them can take the others into itself, so, they proceed on their ways empowering each other. It is also true for the minimalism in art and the minimal invasive surgical approaches in science. Concepts like doing with less, avoiding unnecessary materials and reducing the number of the elements in order to increase the effect in the expression which are the main elements of the minimalism in art found their equivalents in medicine and neurosurgery. Their equivalents in medicine or neurosurgery have been to protect the physical integrity of the patient with less iatrogenic injury, minimum damage and the same therapeutic effect in the most effective way and to enable the patient to regain his health in the shortest span of time.

  1. Virtual endoscopy in neurosurgery: a review.

    PubMed

    Neubauer, André; Wolfsberger, Stefan

    2013-01-01

    Virtual endoscopy is the computerized creation of images depicting the inside of patient anatomy reconstructed in a virtual reality environment. It permits interactive, noninvasive, 3-dimensional visual inspection of anatomical cavities or vessels. This can aid in diagnostics, potentially replacing an actual endoscopic procedure, and help in the preparation of a surgical intervention by bridging the gap between plain 2-dimensional radiologic images and the 3-dimensional depiction of anatomy during actual endoscopy. If not only the endoscopic vision but also endoscopic handling, including realistic haptic feedback, is simulated, virtual endoscopy can be an effective training tool for novice surgeons. In neurosurgery, the main fields of the application of virtual endoscopy are third ventriculostomy, endonasal surgery, and the evaluation of pathologies in cerebral blood vessels. Progress in this very active field of research is achieved through cooperation between the technical and the medical communities. While the technology advances and new methods for modeling, reconstruction, and simulation are being developed, clinicians evaluate existing simulators, steer the development of new ones, and explore new fields of application. This review introduces some of the most interesting virtual reality systems for endoscopic neurosurgery developed in recent years and presents clinical studies conducted either on areas of application or specific systems. In addition, benefits and limitations of single products and simulated neuroendoscopy in general are pointed out.

  2. Case-control studies in neurosurgery.

    PubMed

    Nesvick, Cody L; Thompson, Clinton J; Boop, Frederick A; Klimo, Paul

    2014-08-01

    Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting. The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure

  3. Development and Evaluation of a Registration Methodology for Information-Guided Precision Robotic Laser Neurosurgery System

    NASA Astrophysics Data System (ADS)

    Nakamura, Ryoichi; Hara, Mikiko; Omori, Shigeru; Uematsu, Miyuki; Umezu, Mitsuo; Muragaki, Yoshihiro; Iseki, Hiroshi

    To establish safe, precise, and minimally invasive surgery, Computer Aided Surgery (CAS) systems, such as intra-operative imaging and navigation system to detect the location of the target of therapy, and surgical robot system, are very powerful tools. There is strong need to combine these CAS systems for fusion of advanced diagnosis and treatment technologies. In this paper, we introduce our new method to register the intraoperative imaging information, robotic surgery system, and patient using surgical navigation system. Using our Open-MRI navigation system and laser surgery system for neurosurgery, we can make registration between these system and patient precisely. The experimental result shows that the error on the registration between image data and the laser surgery system is low enough to fulfill the requirement of laser surgery system in the use of high-resolution image data. This system realizes the safe, precise and minimally invasive neurosurgery by the combination of intra-operative diagnosis and advanced therapeutic device.

  4. Pharmacologic modulation of experimental postischemic hepatic function.

    PubMed Central

    Ontell, S J; Makowka, L; Trager, J; Mazzaferro, V; Ove, P; Starzl, T E

    1989-01-01

    The present study evaluated and compared the effects of SRI 63-441, a potent platelet activating factor antagonist, superoxide dismutase (SOD), an oxygen free radical scavenger, and ibuprofen, a cyclooxygenase inhibitor on hepatic function after 90 minutes of warm ischemia. After warm ischemia, livers were harvested and underwent 90 minutes of warm, oxygenated, sanguinous perfusion on an isolated liver perfusion apparatus. Pretreatment of donor animals with 20 mg/kg intravenous (I.V.) SRI 63-441 5 minutes before induction of total hepatic ischemia resulted in significantly increased bile production, a significant decrease in transaminase release, and a higher tissue adenosine triphosphate (ATP) content when compared with ischemic nontreated controls. SOD resulted in improved bile production and decreased transaminase liberation only when present in the perfusate at the time of in vitro reperfusion. Ibuprofen did not improve postischemic hepatic function in this model. Electron microscopy revealed patchy hepatocellular vacuolization with an intact sinusoidal endothelium in all ischemic livers. However, the degree of damage was less severe in the livers from those rats pretreated with 20 mg/kg SRI 63-441. This study demonstrates that SRI 63-441 pretreatment significantly reduces hepatic warm ischemic injury, and in the present model, appears superior to two other agents that have been advanced in the treatment of ischemic injury. The use of such agents singly or in combinations have important implications as regards gaining a better understanding of the basic mechanisms in organ ischemia, and moreover, for therapeutic applications in organ ischemia and preservation. Images Fig. 3. Figs. 6A-C. Figs. 6A-C. Fig. 7. Figs. 8A-C. Figs. 8A-C. PMID:2916864

  5. Options for perioperative pain management in neurosurgery

    PubMed Central

    Vadivelu, Nalini; Kai, Alice M; Tran, Daniel; Kodumudi, Gopal; Legler, Aron; Ayrian, Eugenia

    2016-01-01

    Moderate-to-severe pain following neurosurgery is common but often does not get attention and is therefore underdiagnosed and undertreated. Compounding this problem is the traditional belief that neurosurgical pain is inconsequential and even dangerous to treat. Concerns about problematic effects associated with opioid analgesics such as nausea, vomiting, oversedation, and increased intracranial pressure secondary to elevated carbon dioxide tension from respiratory depression have often led to suboptimal postoperative analgesic strategies in caring for neurosurgical patients. Neurosurgical patients may have difficulty or be incapable of communicating their need for analgesics due to neurologic deficits, which poses an additional challenge. Postoperative pain control should be a priority, because pain adversely affects recovery and patient outcomes. Inconsistent practices and the quality of current analgesic strategies for neurosurgical patients still leave room for improvement. Given the complexity of postoperative pain management for these patients, multimodal strategies are often required to optimize pain control and at the same time limit undesired side effects. PMID:26929661

  6. Life and Medical Ethics in Pediatric Neurosurgery

    PubMed Central

    YAMASAKI, Mami

    2017-01-01

    Ethical issues in the field of pediatric neurosurgery, including prenatal diagnosis, palliative care for children with an intractable serious disease, and medical neglect, are discussed. An important role of medicine is to offer every possible treatment to a patient. However, it also is the responsibility of medicine to be conscious of its limitations, and to help parents love and respect a child who suffers from an incurable disease. When dealing with cases of medical neglect and palliative care for an incurable disease, it is critical to diagnose the child’s condition accurately and evaluate the outcome. However, to treat or not to treat also depends on the medical resources and social-economic status of the community, the parents’ religion and philosophy, the policies of the institutions involved, and the limits of medical science. Moral dilemmas will continue to be addressed as medical progress yields treatments for untreatable diseases in the future. PMID:28025426

  7. Comprehensive review on rhino-neurosurgery

    PubMed Central

    Hosemann, Werner; Schroeder, Henry W.S.

    2015-01-01

    In the past 2 decades, an innovative and active field of surgical collaboration has been evolved and established combining the expertise of neurosurgery and rhinosurgery in the endonasal treatment of different lesions affecting the anterior skull base together with the adjacent intranasal and intradural areas. Important prerequisites for this development were improvements of technical devices, definitions of transnasal surgical corridors, and approvements in endonasal reconstructions, e.g. by use of pedicled nasal mucosal flaps. Due to these improvements, the rate of perioperative infectious complications remained acceptable. Interdisciplinary surgical teams (4-hands-2-minds) have been established constituting specialized centers of “rhino-neurosurgery”. With growing expertise of these groups, it could be shown that oncological results and perioperative complications were comparable to traditional surgery while at the same time the patients’ morbidity could be reduced. The present review encompasses the recent literature focusing on the development, technical details, results, and complications of “rhino-neurosurgery”. PMID:26770276

  8. Advanced 3-dimensional planning in neurosurgery.

    PubMed

    Ferroli, Paolo; Tringali, Giovanni; Acerbi, Francesco; Schiariti, Marco; Broggi, Morgan; Aquino, Domenico; Broggi, Giovanni

    2013-01-01

    During the past decades, medical applications of virtual reality technology have been developing rapidly, ranging from a research curiosity to a commercially and clinically important area of medical informatics and technology. With the aid of new technologies, the user is able to process large amounts of data sets to create accurate and almost realistic reconstructions of anatomic structures and related pathologies. As a result, a 3-diensional (3-D) representation is obtained, and surgeons can explore the brain for planning or training. Further improvement such as a feedback system increases the interaction between users and models by creating a virtual environment. Its use for advanced 3-D planning in neurosurgery is described. Different systems of medical image volume rendering have been used and analyzed for advanced 3-D planning: 1 is a commercial "ready-to-go" system (Dextroscope, Bracco, Volume Interaction, Singapore), whereas the others are open-source-based software (3-D Slicer, FSL, and FreesSurfer). Different neurosurgeons at our institution experienced how advanced 3-D planning before surgery allowed them to facilitate and increase their understanding of the complex anatomic and pathological relationships of the lesion. They all agreed that the preoperative experience of virtually planning the approach was helpful during the operative procedure. Virtual reality for advanced 3-D planning in neurosurgery has achieved considerable realism as a result of the available processing power of modern computers. Although it has been found useful to facilitate the understanding of complex anatomic relationships, further effort is needed to increase the quality of the interaction between the user and the model.

  9. Evolving virtual reality simulation in neurosurgery.

    PubMed

    Schirmer, Clemens M; Mocco, J; Elder, J Bradley

    2013-10-01

    Virtual reality (VR) applications promise the safe, efficacious, and valid replication of scenarios encountered in modern neurosurgery, and a number of navigation- or dissection-related and endovascular simulators have been successfully deployed in the last 2 decades. Concurrently, neurosurgical training is changing, and VR simulations are expected to play a part in future training. To give an overview of currently available neurosurgical VR applications in the spectrum of desired applications and the outlook of the requirements to be met by future applications. The available literature was analyzed using structured Medline and PubMed searches. Relevant articles were retrieved and reviewed. When quantitative results were available, effect sizes were collated or estimated to check for publication bias. There has been a significant increase in publications concerning the use of VR in neurosurgery in the last 22 years (P < .001). Thirty-eight of 117 publications (32%) identified reported data regarding the use of a simulator by practitioners; 35 of these were reported as positive trials (92%). Twenty-two of 38 studies (58%) reported quantitative data with mostly small positive effect sizes (median, 1.41; interquartile range, 1.08-2). The use of VR simulators in endovascular surgery has the most robust basis, with 65% of studies reporting quantitative outcomes. Current neurosurgical VR applications focus on basic procedural skill acquisition and are valid and efficacious adjuncts to neurosurgical training. In the future, the development of complex procedural simulators, teamwork, and focus on validated measures will lead to robust framework of the use of VR over the entire career of a neurosurgeon.

  10. Recent Trends in Conducting School-Based Experimental Functional Analyses

    ERIC Educational Resources Information Center

    Carter, Stacy L.

    2009-01-01

    Demonstrations of school-based experimental functional analyses have received limited attention within the literature. School settings present unique practical and ethical concerns related to the implementation of experimental analyses which were originally developed within clinical settings. Recent examples have made definite contributions toward…

  11. Medieval neurosurgery: contributions from the Middle East, Spain, and Persia.

    PubMed

    Rahimi, Scott Y; McDonnell, Dennis E; Ahmadian, Amir; Vender, John R

    2007-01-01

    Modern neurological and spinal surgical techniques have been developed on the foundations established by predecessors. Modern 21st century neurosurgery begins in the Babylonian period, with the Edwin Smith papyrus. Throughout history, periods of enlightenment have resulted in advances in knowledge and understanding that have served as stepping stones for generations to come. As in other fields, in neurosurgery these periods of "enlightenment" have occurred in a variety of civilizations and time periods.

  12. The evolution of military neurosurgery in the Turkish army.

    PubMed

    Izci, Yusuf

    2010-05-01

    The history of neurosurgery in the Turkish army is not long and complex. Neurosurgery was first practiced in the Ottoman army by Cemil Pasha, who was a general surgeon. After the fall of the Ottoman Empire, the Republic of Turkey was established and modern neurosurgical procedures were applied at the Gulhane Military Medical Academy (GMMA). Maj. Zinnur Rollas, M.D., was the founder of the Department of Neurosurgery at GMMA in 1957. A modern neurosurgical program and school was established in 1965 by Col. Hamit Ziya Gokalp, M.D., who completed his residency training in the US. Today, 26 military neurosurgeons are on active duty in 11 military hospitals in Turkey. All of these neurosurgeons work in modern clinics and operating theaters. In this paper, military neurosurgery in the Turkish army is reported in 3 parts: 1) the history of neurosurgery in the Turkish military, 2) the Department of Neurosurgery at the GMMA, and 3) the duties of a military neurosurgeon in the Turkish army.

  13. Language outcomes following neurosurgery for brain tumours: a systematic review.

    PubMed

    Finch, Emma; Copland, David A

    2014-01-01

    Language function is susceptible to the effects of brain tumours during both the tumour growth phase and during neurosurgical resection. This paper aimed to systematically review existing literature to determine the current status of knowledge about language outcomes following neurosurgery. A systematic review was conducted involving a detailed literature search using online databases, quality assessment of relevant articles and data extraction. Of the 1449 articles retrieved, nine articles satisfied the study criteria. Overall, these studies reported variable patterns of language function post-surgery, however, there was a trend towards an early post-surgical decline in language function that greatly improved by 3 months. The likelihood of developing post-surgical communication impairments was influenced by a number of factors including pre-operative aphasia and the identification of sub-cortical language tracts inside the tumour margin, however, further research is required to fully elucidate pertinent predictors. These findings have implications for rehabilitation programs following brain tumour surgery and suggest that there are a number of key gaps warranting further investigation.

  14. Studying Behaviors Among Neurosurgery Residents Using Web 2.0 Analytic Tools.

    PubMed

    Davidson, Benjamin; Alotaibi, Naif M; Guha, Daipayan; Amaral, Sandi; Kulkarni, Abhaya V; Lozano, Andres M

    2017-06-02

    Web 2.0 technologies (e.g., blogs, social networks, and wikis) are increasingly being used by medical schools and postgraduate training programs as tools for information dissemination. These technologies offer the unique opportunity to track metrics of user engagement and interaction. Here, we employ Web 2.0 tools to assess academic behaviors among neurosurgery residents. We performed a retrospective review of all educational lectures, part of the core Neurosurgery Residency curriculum at the University of Toronto, posted on our teaching website (www.TheBrainSchool.net). Our website was developed using publicly available Web 2.0 platforms. Lecture usage was assessed by the number of clicks, and associations were explored with lecturer academic position, timing of examinations, and lecture/subspecialty topic. The overall number of clicks on 77 lectures was 1079. Most of these clicks were occurring during the in-training examination month (43%). Click numbers were significantly higher on lectures presented by faculty (mean = 18.6, standard deviation ± 4.1) compared to those delivered by residents (mean = 8.4, standard deviation ± 2.1) (p = 0.031). Lectures covering topics in functional neurosurgery received the most clicks (47%), followed by pediatric neurosurgery (22%). This study demonstrates the value of Web 2.0 analytic tools in examining resident study behavior. Residents tend to "cram" by downloading lectures in the same month of training examinations and display a preference for faculty-delivered lectures. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  15. Aura of technology and the cutting edge: a history of lasers in neurosurgery.

    PubMed

    Ryan, Robert W; Spetzler, Robert F; Preul, Mark C

    2009-09-01

    In this historical review the authors examine the important developments that have led to the availability of laser energy to neurosurgeons as a unique and sometimes invaluable tool. They review the physical science behind the function of lasers, as well as how and when various lasers based on different lasing mediums were discovered. They also follow the close association between advances in laser technology and their application in biomedicine, from early laboratory experiments to the first clinical experiences. Because opinions on the appropriate role of lasers in neurosurgery vary widely, the historical basis for some of these views is explored. Initial enthusiasm for a technology that appears to have innate advantages for safe resections has often given way to the strict limitations and demands of the neurosurgical operating theater. However, numerous creative solutions to improve laser delivery, power, safety, and ergonomics demonstrate the important role that technological advances in related scientific fields continue to offer neurosurgery. Benefiting from the most recent developments in materials science, current CO(2) laser delivery systems provide a useful addition to the neurosurgical armamentarium when applied in the correct circumstances and reflect the important historical advances that come about from the interplay between neurosurgery and technology.

  16. Bulgarian military neurosurgery: from Warsaw Pact to the North Atlantic Treaty Organization.

    PubMed

    Enchev, Yavor; Eftimov, Tihomir

    2010-05-01

    After 45 years as a closest ally of the Soviet Union in the Warsaw Pact, founded mainly against the US and the Western Europe countries, and 15 years of democratic changes, since 2004 Bulgaria has been a full member of NATO and an equal and trusted partner of its former enemies. The unprecedented transformation has affected all aspects of the Bulgarian society. As a function of the Bulgarian Armed Forces, Bulgarian military medicine and in particular Bulgarian military neurosurgery is indivisibly connected with their development. The history of Bulgarian military neurosurgery is the history of the transition from the Union of Soviet Socialist Republics military system and military medicine to NATO standards in every aspect. The career of the military neurosurgeon in Bulgaria is in many ways similar to that of the civilian neurosurgeon, but there are also many peculiarities. The purpose of this study was to outline the background and the history of Bulgarian military neurosurgery as well as its future trends in the conditions of world globalization.

  17. Evolution in Practice: How has British Neurosurgery Changed in the Last 10 Years?

    PubMed Central

    Tarnaris, A; Arvin, B; Ashkan, K

    2008-01-01

    INTRODUCTION Neurosurgery is a fast-evolving surgical subspecialty driven by technological advances, socio-economic factors and patient expectations. In this study, we have compared the work-load volume in a single institution in the years of 1994 and 2004 and commented on the possible reasons for the changes and the impacts they may have for the future. PATIENTS AND METHODS A retrospective, log-book review of all operations performed in the years 1994 and 2004 in a single, tertiary, neurosurgical centre was performed. RESULTS Neurosurgical practice has evolved over this period. Current practice has moved away from clipping of aneurysms and towards coil embolisation performed by interventional radiologists. Electrode stimulation of deep brain regions for movement disorders is the current practice, whereas 10 years ago the same disorders were dealt with by lesioning of the relevant regions. In spinal neurosurgery, instrumentation is increasingly favoured currently. In the field of neuro-oncology, current practice favours minimal access to the target area by the use of stereotactic localisation. CONCLUSIONS Changes were most pronounced in the subspecialties of vascular, functional and spinal neurosurgery within this 10-year period. Knowledge of such dynamics is valuable in health resource management as well as planning for neurosurgical training programmes. PMID:18765031

  18. The Preferred Learning Styles of Neurosurgeons, Neurosurgery Residents, and Neurology Residents: Implications in the Neurosurgical Field.

    PubMed

    Lai, Hung-Yi; Lee, Ching-Yi; Chiu, Angela; Lee, Shih-Tseng

    2014-01-01

    To delineate the learning style that best defines a successful practitioner in the field of neurosurgery by using a validated learning style inventory. The Kolb Learning Style Inventory, a validated assessment tool, was administered to all practicing neurosurgeons, neurosurgical residents, and neurology residents employed at Chang Gung Memorial Hospital, an institution that provides primary and tertiary clinical care in 3 locations, Linkou, Kaohsiung, and Chiayi. There were 81 participants who entered the study, and all completed the study. Neurosurgeons preferred the assimilating learning style (52%), followed by the diverging learning style (39%). Neurosurgery residents were slightly more evenly distributed across the learning styles; however, they still favored assimilating (32%) and diverging (41%). Neurology residents had the most clearly defined preferred learning style with assimilating (76%) obtaining the large majority and diverging (12%) being a distant second. The assimilating and diverging learning styles are the preferred learning styles among neurosurgeons, neurosurgery residents, and neurology residents. The assimilating learning style typically is the primary learning style for neurosurgeons and neurology residents. Neurosurgical residents start off with a diverging learning style and progress toward an assimilating learning style as they work toward becoming practicing neurosurgeons. The field of neurosurgery has limited opportunities for active experimentation, which may explain why individuals who prefer reflective observation are more likely to succeed in this field. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. [Competency-based Neurosurgery Residency Programme].

    PubMed

    Lobato, Ramiro D; Jiménez Roldan, Luis; Alen, José F; Castaño, Ana M; Munarriz, Pablo M; Cepeda, Santiago; Lagares, Alfonso

    2016-01-01

    A programme proposal for competency-based Neurosurgery training adapted to the specialization project is presented. This proposal has been developed by a group of neurosurgeons commissioned by the SENEC (Spanish Society of Neurosurgery) and could be modified to generate a final version that could come into force coinciding with the implementation of the specialization programme. This document aims to facilitate the test of the new programme included in the online version of our journal. Total training period is 6 years; initial 2 years belong to the surgery specialization and remaining 4 years belong to core specialty period. It is a competency-based programmed based on the map used by the US Accreditation Council for Graduate Medical Education (ACGME) including the following domains of clinical competency: Medical knowledge, patient care, communication skills, professionalism, practice-based learning and improvement, health systems, interprofessional collaboration and professional and personal development. Subcompetencies map in the domains of Knowledge and Patient care (including surgical competencies) was adapted to the one proposed by AANS and CNS (annex 1 of the programme). A subcompetency map was also used for the specialization rotations. Resident's training is based on personal study (self-learning) supported by efficient use of information sources and supervised clinical practice, including bioethical instruction, clinical management, research and learning techniques. Resident evaluation proposal includes, among other instruments, theoretical knowledge tests, objective and structured evaluation of the level of clinical competency with real or standardised patients, global competency scales, 360-degree evaluation, clinical record audits, milestones for residents progress and self-assessment (annex 2). Besides, residents periodically assess the teaching commitment of the department's neurosurgeons and other professors participating in rotations, and annually

  20. Introduction: military neurosurgery, past and present.

    PubMed

    Klimo, Paul; Ragel, Brian T

    2010-05-01

    For a physician has the worth of many other warriors, both for the excision of arrows and for the administration of soothing drugs. Homer, Iliad XI.514-515 Ever since armed conflict has been used as a means to settle disputes among men, there have been those who have been tasked to mend the wounds that ravage a soldier's body from the weapons of war. The Iliad portrays the pivotal 10th year of the legendary Trojan War, during which a schism in the Greek leadership prolongs the extended siege of the city of Troy. In the midst of this martial epic come the lines quoted above, quietly attesting to the value of the military physician, even under the crude conditions of the Greek Dark Age. They are uttered by Idomeneus, one of the foremost Greeks, when he is enjoining one of his comrades, Nestor, to rescue the injured Greek physician Machaon and take him back from the line to treat his wounds. He is afraid that Machaon will be captured by the Trojans, a loss far greater than that of any other single warrior. Duty to country has helped shape the careers of many neurosurgeons, including iconic US figures such as Harvey Cushing and Donald Matson. This issue of Neurosurgical Focus celebrates the rich history of military neurosurgery from the wars of yesterday to the conflicts of today. We have been humbled by the tremendous response to this topic. The 25 articles within this issue will provide the reader with both a broad and an in-depth look at the many facets of military neurosurgery. We have attempted to group articles based on their predominant topic. We also encourage our audience to read other recently published articles. The first 8 articles relate to the current conflicts in Afghanistan and Iraq. The lead article, written by Randy Bell and colleagues from the National Naval Medical Center and Walter Reed Army Medical Center, discusses what is arguably one of the most important contributions by military neurosurgeons from these 2 conflicts: the rapid and aggressive

  1. Experimental generation of Bessel-Gauss coherence functions

    NASA Astrophysics Data System (ADS)

    Reddy, Salla Gangi; Singh, R. P.; Miyamoto, Yoko

    2017-04-01

    We experimentally generate the Bessel-Gauss coherence functions using the cross-correlations between the two speckle patterns obtained using the perfect optical vortices (POV) of different orders. POV beams are generated using the Fourier transform of Bessel-Gauss beams by displaying the axicon hologram on spatial light modulator. A ground glass plate is used for scattering POV beams and the speckles are recorded. The cross-correlation function of two speckle patterns is Bessel-Gauss functions whose order is given by the difference in the orders of two POV beams used for scattering. The auto-correlation function of these speckles is Bessel-Gauss function of order zero.

  2. Characterization of SMA actuator for applications in robotic neurosurgery.

    PubMed

    Ho, Mingyen; Desai, Jaydev P

    2009-01-01

    Shape memory alloy has been proven to be MRI compatible and due to its unique microstructure and molecular characteristics, it possesses many unique properties. Additionally, internal resistive heating of the wires eliminates the need for bulky external heating mechanisms. These advantages make SMA actuators good candidates for a wide range of applications in robotic surgical systems when compared to conventional actuators. In this paper, we present our preliminary work towards the development of a SMA based miniature robot for neurosurgery which can be operated under MRI. In this robot, we use two antagonistic SMA wires as actuators for each joint, so that each joint can be operated separately. We also designed an experimental setup to test the SMA wires. The goal of this experiment is to develop a systematic test especially for this robot and to collect sufficient data to estimate the performance of the robot. This setup can also be used to test SMA wires themselves. The data from this experiment will be used to determine important material parameters that are required for analytical models, and then use those models to develop a control strategy to manipulate the SMA actuators.

  3. Nonlinear optical imaging: toward chemical imaging during neurosurgery

    NASA Astrophysics Data System (ADS)

    Meyer, Tobias; Dietzek, Benjamin; Krafft, Christoph; Romeike, Bernd F. M.; Reichart, Rupert; Kalff, Rolf; Popp, Jürgen

    2011-03-01

    Tumor recognition and precise tumor margin detection presents a central challenge during neurosurgery. In this contribution we present our recent all-optical approach to tackle this problem. We introduce various nonlinear optical techniques, such as coherent anti-Stokes Raman scattering (CARS), second-harmonic generation (SHG) and two-photon fluorescence (TPEF), to study the morphology and chemical composition of (ex vivo) brain tissue. As the experimental techniques presented are contact-free all-optical techniques, which do not rely on the administration of external (fluorescence) labels, we anticipate that their implementation into surgical microscopes will provide significant advantages of intraoperative tumor diagnosis. In this contribution an introduction to the different optical spectroscopic methods will be presented and their implementation into a multimodal microscopic setup will be discussed. Furthermore, we will exemplify their application to brain tissue, i.e. both pig brain as a model for healthy brain tissue and human brain samples taken from surgical procedures. The data to be discussed show the capability of a joint CARS/SHG/TPEF multimodal imaging approach in highlighting various aspects of tissue morphochemistry. The consequences of this microspectroscopic potential, when combined with the existing technology of surgical microscopes, will be discussed.

  4. Neurosurgery of the future: Deep brain stimulations and manipulations.

    PubMed

    Nicolaidis, Stylianos

    2017-04-01

    Important advances are afoot in the field of neurosurgery-particularly in the realms of deep brain stimulation (DBS), deep brain manipulation (DBM), and the newly introduced refinement "closed-loop" deep brain stimulation (CLDBS). Use of closed-loop technology will make both DBS and DBM more precise as procedures and will broaden their indications. CLDBS utilizes as feedback a variety of sources of electrophysiological and neurochemical afferent information about the function of the brain structures to be treated or studied. The efferent actions will be either electric, i.e. the classic excitatory or inhibitory ones, or micro-injection of such things as neural proteins and transmitters, neural grafts, implants of pluripotent stem cells or mesenchymal stem cells, and some variants of gene therapy. The pathologies to be treated, beside Parkinson's disease and movement disorders, include repair of neural tissues, neurodegenerative pathologies, psychiatric and behavioral dysfunctions, i.e. schizophrenia in its various guises, bipolar disorders, obesity, anorexia, drug addiction, and alcoholism. The possibility of using these new modalities to treat a number of cognitive dysfunctions is also under consideration. Because the DBS-CLDBS technology brings about a cross-fertilization between scientific investigation and surgical practice, it will also contribute to an enhanced understanding of brain function.

  5. Novel multipurpose bipolar instrument for endoscopic neurosurgery.

    PubMed

    Riegel, Thomas; Freudenstein, Dirk; Alberti, Olaf; Duffner, Frank; Hellwig, Dieter; Bartel, Volker; Bertalanffy, Helmut

    2002-07-01

    Hemorrhage control in endoscopic neurosurgery is critical because of the lack of suitable instruments for coagulation. One reason for this problem is that miniaturization of the instruments is still a technical problem. In this article, we present a solution: the use of bipolar microforceps with a small diameter of 1.5 mm. With the use of modern synthetic and metallic materials, the construction of the bipolar microforceps was designed without the use of mechanical joints. All movable elements are integrated within the instrument shaft. This design provides optimal visibility of the operating field because the sheath has a diameter of only 1.5 mm along its entire length. Therefore, this instrument is compatible with most working channels of neuroendoscopes. The new, joint-free design of the forceps and the electric insulation of the branches were the technical innovations that led to the development of this novel, multipurpose instrument. This new instrument may enhance endoscopic resection and shrinkage of cystic lesions and may offer new possibilities in endoscopic tumor resection and the treatment of hemorrhage.

  6. Neurosurgery in rural Nigeria: A prospective study

    PubMed Central

    Rabiu, Taopheeq Bamidele; Komolafe, Edward Oluwole

    2016-01-01

    Background: Africa has very few neurosurgeons. These are almost exclusively in urban centers. Consequently, people in rural areas, most of the African population, have poor or no access to neurosurgical care. We have recently pioneered rural neurosurgery in Nigeria. Objectives: This report details our initial experiences and the profile of neurosurgical admissions in our center. Methods: A prospective observational study of all neurosurgical patients managed at a rural tertiary health institution in Nigeria from December 2010 to May 2012 was done. Simple descriptive data analysis was performed. Results: A total of 249 males (75.2%) and 82 females (24.8%) were managed. The median age was 37 years (range: Day of birth – 94 years). Trauma was the leading cause of presentation with 225 (68.0%) and 35 (10.6%) having sustained head and spinal injuries, respectively. Operative intervention was performed in 54 (16.3%). Twenty-four (7.2%) patients discharged against medical advice, mostly for economic reasons. Most patients (208, 63.4%) had satisfactory outcome while 30 (9.1%) died. Conclusion: Trauma is the leading cause of rural neurosurgical presentations. There is an urgent need to improve access to adequate neurosurgical care in the rural communities. PMID:27695224

  7. Prophylactic antibiotics and anticonvulsants in neurosurgery.

    PubMed

    Ratilal, B; Sampaio, C

    2011-01-01

    The prophylactic administration of antibiotics to prevent infection and the prophylactic administration of anticonvulsants to prevent first seizure episodes are common practice in neurosurgery. If prophylactic medication therapy is not indicated, the patient not only incurs the discomfort and the inconvenience resulting from drug treatment but is also unnecessarily exposed to adverse drug reactions, and incurs extra costs. The main situations in which prophylactic anticonvulsants and antibiotics are used are described and those situations we found controversial in the literature and lack further investigation are identified: anticonvulsants for preventing seizures in patients with chronic subdural hematomas, antiepileptic drugs for preventing seizures in those suffering from brain tumors, antibiotic prophylaxis for preventing meningitis in patients with basilar skull fractures, and antibiotic prophylaxis for the surgical introduction of intracranial ventricular shunts.In the following we present systematic reviews of the literature in accordance with the standard protocol of The Cochrane Collaboration to evaluate the effectiveness of the use of these prophylactic medications in the situations mentioned. Our goal was to efficiently integrate valid information and provide a basis for rational decision-making.

  8. YouTube as a Source of Information on Neurosurgery.

    PubMed

    Samuel, Nardin; Alotaibi, Naif M; Lozano, Andres M

    2017-09-01

    The importance of videos in social media communications in the context of health care and neurosurgery is becoming increasingly recognized. However, there has not yet been a systematic analysis of these neurosurgery-related communications. Accordingly, this study was aimed at characterizing the online video content pertaining to neurosurgery. Neurosurgery-related videos uploaded on YouTube were collected using a comprehensive search strategy. The following metrics were extracted for each video: number of views, likes, dislikes, comments, shares, date of upload, and geographic region of origin where specified. A quantitative and qualitative evaluation was performed on all videos included in the study. A total of 713 nonduplicate videos met the inclusion criteria. The overall number of views for all videos was 90,545,164. Videos were most frequently uploaded in 2016 (n = 348), with a 200% increase in uploads compared with the previous year. Of the videos that were directly relevant to clinical neurosurgery, the most frequent video categories were "educational videos" (25%), followed by "surgical and procedure overview" (20%), "promotional videos" (17%), and "patient experience" (16%). The remainder of the videos consisted primarily of unrealistic simulations of cranial surgery for entertainment purposes (20%). The findings from this study highlight the increasing use of video communications related to neurosurgery and show that institutions, neurosurgeons, and patients are using YouTube as an educational and promotional platform. As online communications continue to evolve, it will be important to harness this tool to advance patient-oriented communication and knowledge dissemination in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part I-prehistory to 2003.

    PubMed

    Liu, Charles Y; Apuzzo, Michael L J

    2003-01-01

    Despite its singular importance, little attention has been given to the neurosurgical operative environment in the scientific and medical literature. This article focuses attention on the development of neurosurgery and the parallel emergence of its operative setting. The operative environment has, to a large extent, defined the "state of the art and science" of neurosurgery, which is now undergoing rapid reinvention. During the course of its initial invention, major milestones in the development of neurosurgery have included the definition of anatomy, consolidation of a scientific basis, and incorporation of the practicalities of anesthesia and antisepsis and later operative technical adjuvants for further refinement of action and minimalism. The progress, previously long and laborious in emergence, is currently undergoing rapid evolution. Throughout its evolution, the discipline has assimilated the most effective tools of modernity into the operative environment, leading eventually to the entity known as the operating room. In the decades leading to the present, progressive minimalization of manipulation and the emergence of more refined operative definition with increasing precision are evident, with concurrent miniaturization of attendant computerized support systems, sensors, robotic interfaces, and imaging devices. These developments over time have led to the invention of neurosurgery and the establishment of the current state-of-the-art neurosurgical operating room as we understand it, and indeed, to a broader definition of the entity itself. To remain current, each neurosurgeon should periodically reconsider his or her personal operative environment and its functional design with reference to modernity of practice as currently defined.

  10. Shining light on neurosurgery diagnostics using Raman spectroscopy.

    PubMed

    Broadbent, Brandy; Tseng, James; Kast, Rachel; Noh, Thomas; Brusatori, Michelle; Kalkanis, Steven N; Auner, Gregory W

    2016-10-01

    Surgical excision of brain tumors provides a means of cytoreduction and diagnosis while minimizing neurologic deficit and improving overall survival. Despite advances in functional and three-dimensional stereotactic navigation and intraoperative magnetic resonance imaging, delineating tissue in real time with physiological confirmation is challenging. Raman spectroscopy is a promising investigative and diagnostic tool for neurosurgery, which provides rapid, non-destructive molecular characterization in vivo or in vitro for biopsy, margin assessment, or laboratory uses. The Raman Effect occurs when light temporarily changes a bond's polarizability, causing change in the vibrational frequency, with a corresponding change in energy/wavelength of the scattered photon. The recorded inelastic scattering results in a "fingerprint" or Raman spectrum of the constituent under investigation. The amount, location, and intensity of peaks in the fingerprint vary based on the amount of vibrational bonds in a molecule and their ensemble interactions with each other. Distinct differences between various pathologic conditions are shown as different intensities of the same peak, or shifting of a peak based on the binding conformation. Raman spectroscopy has potential for integration into clinical practice, particularly in distinguishing normal and diseased tissue as an adjunct to standard pathologic diagnosis. Further, development of fiber-optic Raman probes that fit through the instrument port of a standard endoscope now allows researchers and clinicians to utilize spectroscopic information for evaluation of in vivo tissue. This review highlights the need for such an instrument, summarizes neurosurgical Raman work performed to date, and discusses the future applications of neurosurgical Raman spectroscopy.

  11. Sub-specialisation in neurosurgery: perspective from a small specialty.

    PubMed

    Ashkan, Keyoumars; Guy, Nicola; Norris, John

    2003-05-01

    There is an increasing tendency towards sub-specialisation in the larger surgical specialties. The feasibility and effectiveness of this is less clear in the smaller specialties with limited manpower such as neurosurgery. To evaluate this, we carried out an audit comparing the throughput and outcome of patients treated for intracranial aneurysms in our unit before and after a period of neurovascular sub-specialisation. In the period before sub-specialisation, 68 aneurysms were treated compared to 69 after sub-specialisation. The epidemiological profile of patients, their clinical condition at presentation and the location of aneurysms were not significantly different in the two periods. There was less morbidity and mortality and better long-term functional outcome (P = 0.05) following sub-specialisation. More investigations including cerebral angiograms were performed after sub-specialisation. The added cost, however, was offset against savings made by the shorter length of patient's hospital stay (P = 0.002). Sub-specialisation appears to confer benefits both in terms of patient outcome and socio-economic gain.

  12. Advanced registered nurse practitioners and physician assistants in the practice of pediatric neurosurgery: a clinical report.

    PubMed

    James, Hector E; MacGregor, Teresa L; Postlethwait, Richard A; Hofrichter, Paul B; Aldana, Phillip R

    2011-01-01

    research projects. They have presented posters in a total of 9 national and 2 international meetings, and have co-authored 8 manuscripts published in peer review journals. The ARNP/PA members have been active participants in all functions of the Division of Pediatric Neurosurgery. They have facilitated the work of the faculty in day-to-day activities and enhanced the scope of divisional activities, providing a team approach for the care of the patients, families, and caretakers. Copyright © 2012 S. Karger AG, Basel.

  13. Clinical and experimental results of photodynamic therapy in neurosurgery

    NASA Astrophysics Data System (ADS)

    Kostron, Herwig; Hochleitner, B. W.; Obwegeser, Alois; Seiwald, M.

    1995-03-01

    Since 1984, 58 patients bearing malignant brain tumors were treated 70 times with photodynamic treatment (PDT). The patient population consisted of 11 primary glioblastoma WHO grade IV, 39 recurrent glioblastomas, 3 malignant meningiomas, 3 recurrent melanomas, and 2 metastasis of carcinomas. The patients were sensitized with hematoporphyrin derivative (HPD) 2.5 mg/bodyweight 24 - 48 hours prior to craniotomy and tumor resection. The light-irradiation was performed by an Argon pumped dye laser (Aurora M) superficially and/or interstitially at a dose ranging up to 250 J/cm2. The median survival of primary glioblastomas was 19 months and for recurrent glioblastomas 7 months, respectively. Malignant meningiomas, as well as melanomas, did not benefit from PDT, whereas one patient with a metastasis of an adenocarcinoma is still recurrence free since 18 months, the other recurred after 6 months. HPD extractions of the tumor revealed significantly different concentrations among the various tumors, but also between identical histologies. The survival, however, did not correlate with the HPD concentration in the tumor. PDT prolongs median survival of primary glioblastomas significantly, and doubles the survival of recurrent high grade gliomas. Furthermore the treatment of recurrent low grade gliomas and metastasis to the brain are promising indications for PDT.

  14. Micromanipulator: effectiveness in minimally invasive neurosurgery.

    PubMed

    Jain, R; Kato, Y; Sano, H; Imizu, S; Watanabe, S; Yamaguchi, S; Shinya, N; Jindal, V; Kanno, T

    2003-08-01

    Minimally invasive surgeries by innovative approaches are practiced in all fields. The evolution of microneurosurgery has revolutionized the results in neurosurgery. Use of endoscopes and navigation has made microsurgery less invasive. Another development to make minimally invasive microneurosurgery further lesser invasive is the use of micromanipulator. The use and effectiveness of manually controlled micromanipulator system is presented. The manually controlled micromanipulator system consists of three parts, i.e., a basic micromanipulator, manipulator supporting device and the manual control. The micromanipulator fitted in supporting device is arranged before the start of surgery. The supporting device used is pneumatically driven powered endoscopic holding device (Mitaka Kohki Co., Tokyo) In maximum number of times we used the system for endoscopic assisted cerebrovascular microneurosurgery. In a span of two months we used it in thirty aneurysm clipping surgeries. The endoscope fitted in system has three ranges of motions (forward/backward, upside/down and sideways). We use MACHIDA rigid endoscope with internal diameter of 2.7 mm (smallest diameter endoscope available). Special features of this endoscope are accurate visualization at a deeper plane, stable movements and availability of single focus point for long time. All these features are valuable during pre- and postoperative clipping observation. The aim of development of micromanipulator system was to further reduce invasiveness. A significant improvement in manual dexterity is possible when working through the micromanipulator interface, which dampens human physiological tremor. The physiological tremor would render the manual dexterity unsafe at the end of lever arm of long instruments. Thus, the use endoscope becomes practical. The minimally invasive microneurosurgery can be further made lesser invasive by use of micromanipulator and we are convinced that this will facilitate more accurate and

  15. Highly cited works in skull base neurosurgery.

    PubMed

    Khan, Nickalus R; Lee, Siang Liao; Brown, Matthew; Reding, Jonathan; Angotti, Jonathan; Lepard, Jacob; Gabrick, Kyle; Klimo, Paul; Michael, L Madison

    2015-04-01

    Citation analysis can be used to evaluate an article's impact on its discipline. This study characterizes the most-cited articles related to skull base surgery. The 100 most-cited skull base neurosurgery articles in all journals were examined. A separate listing of the top 100 most-cited articles in dedicated skull base journals was also examined. The following information was recorded for each article: number of authors, country of origin, citation-count adjusted for number of years in print, topic, and level of evidence. The 100 overall most-cited articles appeared in 25 journals. The top 100 most-cited articles in dedicated skull base journals appeared in 3 journals. Publication dates ranged from 1965-2006 for the overall list and 1993-2010 for the dedicated skull base list. Citations ranged from 11-59 (mean, 19) for the dedicated skull base list and 115-487 for the overall list (mean, 175). The average time-adjusted citation count was 8.4 for the overall list and 2 for the dedicated skull base journal list. An original article in a nondedicated skull base journal related to the subspecialty of skull base with a citation count of 150 or more and time-adjusted citation count of 10 can be considered a high-impact publication. An original article in a dedicated skull base periodical having a total citation count of 20 or more and an average citation count of 2 per year or more can be considered a high impact publication. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Linac radiosurgery as a tool in neurosurgery.

    PubMed

    Deinsberger, R; Tidstrand, J

    2005-04-01

    Stereotactic radiosurgery is a radiation technique that uses a high radiation dose focused on a stereotactic defined intracranial target in single fraction with high precision. In the 1980s, linear accelerators were introduced as a tool for radiosurgery beneath the already accepted gamma unit. Technique and mechanical precision of LINACs have become equal to the gamma unit and LINAC radiosurgery became more and more used recently. From January 1996 to August 2003 we have treated 237 patients with LINAC radiosurgery. A combination of the University of Florida system and the X Knife System, developed by Radionics, was used in all patients. A number of 110 patients had 161 brain metastases treated, whereas the local tumor control rate was 89.4%. The 1-year survival rate was 54.9% with a median survival of 54 weeks. In 55 patients we have treated 57 meningiomas, mostly located at the skull base (37 out of 55 patients). Local tumor control rate in our patients with skull base meningiomas at 5-year follow up was 97.2%. In this time period, we have also treated acoustic schwannoma, glioma, pituitary adenoma, arteriovenous malformations and patients with trigeminal neuralgia. LINAC radiosurgery has become a daily tool in neurosurgery and changed treatment strategies especially in the treatment of brain metastases and skull base meningiomas towards a less aggressive and multimodality approach. It is not only an alternative to open surgery, but also a very effective adjuvant treatment modality in many neuro-oncological patients, which helps us to enhance tumor control rate, minimize morbidity and increase postoperative quality of life.

  17. Augmented reality in neurosurgery: a systematic review.

    PubMed

    Meola, Antonio; Cutolo, Fabrizio; Carbone, Marina; Cagnazzo, Federico; Ferrari, Mauro; Ferrari, Vincenzo

    2016-05-07

    Neuronavigation has become an essential neurosurgical tool in pursuing minimal invasiveness and maximal safety, even though it has several technical limitations. Augmented reality (AR) neuronavigation is a significant advance, providing a real-time updated 3D virtual model of anatomical details, overlaid on the real surgical field. Currently, only a few AR systems have been tested in a clinical setting. The aim is to review such devices. We performed a PubMed search of reports restricted to human studies of in vivo applications of AR in any neurosurgical procedure using the search terms "Augmented reality" and "Neurosurgery." Eligibility assessment was performed independently by two reviewers in an unblinded standardized manner. The systems were qualitatively evaluated on the basis of the following: neurosurgical subspecialty of application, pathology of treated lesions and lesion locations, real data source, virtual data source, tracking modality, registration technique, visualization processing, display type, and perception location. Eighteen studies were included during the period 1996 to September 30, 2015. The AR systems were grouped by the real data source: microscope (8), hand- or head-held cameras (4), direct patient view (2), endoscope (1), and X-ray fluoroscopy (1) head-mounted display (1). A total of 195 lesions were treated: 75 (38.46 %) were neoplastic, 77 (39.48 %) neurovascular, and 1 (0.51 %) hydrocephalus, and 42 (21.53 %) were undetermined. Current literature confirms that AR is a reliable and versatile tool when performing minimally invasive approaches in a wide range of neurosurgical diseases, although prospective randomized studies are not yet available and technical improvements are needed.

  18. Silent pulmonary thromboembolism in neurosurgery patients

    PubMed Central

    Tian, Rui; Gao, Jun; Chen, Alof; Bao, Xinjie; Guan, Jian; Feng, Ming; Li, Yongning; Ma, Wenbin; Ren, Zuyuan; Wang, Renzhi; Wei, Junji

    2016-01-01

    Abstract Background: The requirement of postoperative bedridden and immobilization renders neurosurgical patients with higher risk of deep vein thrombosis (DVT), then more vulnerable for pulmonary thromboembolism (PTE). But silent pulmonary thromboembolism (SPTE) can be the very early stage of any typical form of PTE, its diagnosis and management is therefore critical in neurosurgical departments. However, to date, perioperative SPTE has not been attached with enough attention. Methods: Here, we report 2 cases of perioperative SPTE in the Department of Neurosurgery, Peking Union Medical College Hospital, Beijing, China. Clinical data of 2 cases was collected and analyzed. Both patients were screened by quantitative D-dimer assay and lower limbs ultrasonography, while diagnoses were made according to computed tomographic pulmonary angiography (CTPA). Therapeutic medications include heparin, low molecular weight heparin, followed by long-term anticoagulation with oral warfarin. Both cases showed significantly elevated D-dimer before and after onset of SPTE. But in 1 case, ultrasonography reported negative venous thromboembolism. CTPA confirmed all diagnosis of SPTE. Repeated CTPA after anticoagulant therapy identified therapeutic efficacy. And during the follow-up period of 5 or 6 years, both patients acquired full recovery without clinical complications. Results: Significant decline of D-dimer was observed after the comprehensive management of SPTE (case 1: preop vs postop 573 vs 50 μg/L; case 2: preop vs postop 246 vs 50 μg/L). Ultrasonography was used for suspicious of DVT, while CTPA was used for confirming SPTE diagnosis. Conclusion: Clinicians should be aware of the importance of early recognition of SPTE. Effective management of risk factors of hyper-coagulation state should be the key to prophylaxis. And routine monitor of D-dimer as well as regular check of lower limbs ultrasonography should be standardized and included in guidelines of neurosurgical

  19. Neurosurgery and elderly: analysis through the years.

    PubMed

    Chibbaro, Salvatore; Di Rocco, F; Makiese, O; Mirone, G; Marsella, M; Lukaszewicz, A C; Vicaut, E; Turner, B; Hamdi, S; Spiriev, T; Di Emidio, P; Pirracchio, R; Payen, D; George, B; Bresson, D

    2010-04-01

    The aging of the population in westernized countries constitutes an important issue for the health systems struggling with limited resources and increasing costs. Morbidity and mortality rates reported for neurosurgical procedures in the elderly vary widely. The lack of data on risk benefit ratios may result in challenging clinical decisions in this expanding group of patients. The aim of this paper is to analyze the elderly patients cohort undergoing neurosurgical procedures and any trend variations over time. The medical records of elderly patients (defined as an individual of 70 years of age and over) admitted to the Neurosurgical and Neuro-ICU Departments of a major University Hospital in Paris over a 25-year period were retrospectively reviewed. The analysis included: (1) number of admissions, (2) percentage of surgically treated patients, (3) type of procedures performed, (4) length of hospital stay, and (5) mortality. The analysis showed a progressive and significant increase in the proportion of elderly presenting for neurosurgical elective and/or emergency procedures over the last 25 years. The number of procedures on patients over 70 years of age increased significantly whereas the mortality dropped. Though the length of hospital stay was reduced, it remained significantly higher than the average stay. The types of procedures also changed over time with more craniotomies and endovascular procedures being performed. Age should not be considered as a contraindication for complex procedures in neurosurgery. However, downstream structures for postoperative elderly patients must be further developed to reduce the mean hospital stay in neurosurgical departments because this trend is likely to continue to grow.

  20. Neurosurgery in the realm of 10(-9), Part 2: applications of nanotechnology to neurosurgery--present and future.

    PubMed

    Elder, James B; Liu, Charles Y; Apuzzo, Michael L J

    2008-02-01

    Neurosurgery in the future will witness an increasing influx of novel technologies, many of which will be based on developments in the emerging science of nanotechnology. Additionally, the continued trend in medicine toward minimally invasive diagnostic and surgical techniques will be aided by incorporation of applications of nanotechnology. Neurosurgeons of the future must facilitate the development of nanotechnology and nanomedicine in their clinical practice and research efforts to optimize patient benefit and facilitate scientific advancement. The fields of nanotechnology and nanomedicine remain in their infancy. Recently, however, the literature regarding nanoscience has rapidly expanded. This article is the second of two and provides a review of recent nanotechnology research relevant to clinical neurosurgery and neurology. The first article reviewed recent developments and issues in nanotechnology with a particular focus on applications to the neurosciences. This article also discusses current developments in nanotechnology and nanomedicine that may yield applications in neurosurgery in the future. Additional attention is given to other emerging technologies that are not truly nanotechnology, such as microelectromechanical systems, which will influence the future of medicine and neurosurgery. The goal is to provide the reader with a brief outline and description of some of the new developments in nanotechnology that may affect the clinical practice or operative experience of neurosurgeons. Continued innovation in nanotechnology presents novel opportunities for translation to the clinical arena. Neuroscience, neurology, and neurosurgery will be greatly affected by the influx of nanoscience and its applications. Through continued collaboration, physicians, scientists, and engineers will shape the futures of nanomedicine and nanoneurosurgery.

  1. History of Neurosurgery in Democratic People's Republic of Korea.

    PubMed

    Park, Kee B; Roh, Young Han; Lee-Park, Owen; Park, Sophie

    2015-09-01

    Neurosurgery in Democratic People's Republic of Korea (DPRK) has undergone remarkable progress since its beginning in the 1950s. With the initial support from socialist countries of the Soviet bloc, especially Professor Constantin Arseni of Romania, the nation has consistently produced a number of its own neurosurgeons each year and fostered further advancement by establishing the Korean Neurosurgery Association (DPRK). Despite the recent international collaborative activity for North Korean neurosurgery-namely with Foundation for International Education in Neurological Surgery, World Federation of Neurological Surgeons, and Korean American Medical Association-the sparse exchange of information, knowledge, and surgical skills still remains largely inadequate. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Appraisal of the Quality of Neurosurgery Clinical Practice Guidelines.

    PubMed

    Ducis, Katrina; Florman, Jeffrey E; Rughani, Anand I

    2016-06-01

    The rate of neurosurgery guidelines publications was compared over time with all other specialties. Neurosurgical guidelines and quality of supporting evidence were then analyzed and compared by subspecialty. The authors first performed a PubMed search for "Neurosurgery" and "Guidelines." This was then compared against searches performed for each specialty of the American Board of Medical Specialties. The second analysis was an inventory of all neurosurgery guidelines published by the Agency for Healthcare Research and Quality Guidelines clearinghouse. All Class I evidence and Level 1 recommendations were compared for different subspecialty topics. When examined from 1970-2010, the rate of increase in publication of neurosurgery guidelines was about one third of all specialties combined (P < 0.0001). However, when only looking at the past 5 years the publication rate of neurosurgery guidelines has converged upon that for all specialties. The second analysis identified 49 published guidelines for assessment. There were 2733 studies cited as supporting evidence, with only 243 of these papers considered the highest class of evidence (8.9%). These papers were used to generate 697 recommendations, of which 170 (24.4%) were considered "Level 1" recommendations. Although initially lagging, the publication of neurosurgical guidelines has recently increased at a rate comparable with that of other specialties. However, the quality of the evidence cited consists of a relatively low number of high-quality studies from which guidelines are created. Wider implications of this must be considered when defining and measuring quality of clinical performance in neurosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Fast forwarding: the evolution of neurosurgery. The 2005 presidential address.

    PubMed

    Ratcheson, Robert A

    2005-10-01

    Despite the major social and economic reorganization of medical practice that has taken place during the past 40 years, neurosurgery-the most fascinating specialty in all of clinical medicine-has grown and prospered. Today, this specialty is poised for an era of spectacular advancement and improvement in care; however, significant problems with the potential to retard this growth face neurosurgery. Among these problems is the medical liability situation, which has the potential to destabilize neurosurgical practices and the current health care delivery system. Other issues facing neurosurgery include the potential for loss of the unique nature of the specialty through a conversion to shift-worker surgeons and increasing reliance on profit-seeking institutions for financial stability and liability protection. Lifestyle choices are of growing importance and currently discourage women from entering the field. With a growing knowledge base, there is the recognition that it may not be possible for most individuals to master all aspects of the specialty. There is continued confusion about manpower needs. In addition, some neurosurgeons are choosing to practice in ways that fail to meet the neurosurgeon's obligations to society. There is a growing number of neurosurgeons who dislike providing trauma coverage and there is the potential for some neurosurgeons to give up intracranial neurosurgery. The author believes that it is not competition that will improve the delivery of neurosurgical care and allow for continued growth, but cooperation, and that it will be possible to alleviate many of our problems through increased regionalization of neurosurgical care delivery. This proposal has the potential to promote the formation of neurosurgical teams, ameliorate the problem of physician fatigue, allow greater development of subspecialty skills, and ease the burden of trauma call. It should allow satisfactory solutions to lifestyle considerations and encourage more women to

  4. Using experimental evolution to probe molecular mechanisms of protein function.

    PubMed

    Fischer, Marlies; Kang, Mandeep; Brindle, Nicholas Pj

    2016-02-01

    Directed evolution is a powerful tool for engineering protein function. The process of directed evolution involves iterative rounds of sequence diversification followed by assaying activity of variants and selection. The range of sequence variants and linked activities generated in the course of an evolution are a rich information source for investigating relationships between sequence and function. Key residue positions determining protein function, combinatorial contributors to activity and even potential functional mechanisms have been revealed in directed evolutions. The recent application of high throughput sequencing substantially increases the information that can be retrieved from directed evolution experiments. Combined with computational analysis this additional sequence information has allowed high-resolution analysis of individual residue contributions to activity. These developments promise to significantly enhance the depth of insight that experimental evolution provides into mechanisms of protein function.

  5. Government Medical College Trivandrum - Fifty years of Neurosurgery in Kerala state.

    PubMed

    Peethambaran, Anil Kumar; Chandran, Raj S

    2017-01-01

    The Department of Neurosurgery founded in the Trivandrum Medical College, Kerala, the first teaching hospital in Kerala state, is celebrating its 50th anniversary. The history of Neurosurgery in this Institute is synonymous with the history of Neurosurgery in the state as this was the first medical college to start a Neurosurgery department within the state.The students after undergoing their rigorous training in the department, went on to establish advanced neurosurgical centres throughout Kerala and in several other parts of the country. This article traces the illustrious history of the Department of Neurosurgery, Trivandrum Medical College and also of the eminent faculty members and residents, who helped in advancing the standards of Neurosurgery in the region as well as the rest of India. The Department of Neurosurgery was founded in the Trivandrum Medical College, Kerala, the first teaching hospital in Kerala state, in the year 1951, and is celebrating its 50th anniversary. The history of Neurosurgery in this Institute is synonymous with the history of Neurosurgery in the state as this was the first medical college to start a Neurosurgery department within the state.The students after undergoing their rigorous training in the department, went on to establish advanced neurosurgical centres throughout Kerala and in several other parts of the country. This article traces the illustrious history of the Department of Neurosurgery, Trivandrum Medical College and also of the eminent faculty members and residents, who helped in advancing the standards of Neurosurgery in the region as well as the rest of India.

  6. Mobile pediatric neurosurgery: rapid response neurosurgery for remote or urgent pediatric patients.

    PubMed

    Owler, Brian K; Carmo, Kathryn A Browning; Bladwell, Wendy; Fa'asalele, T Arieta; Roxburgh, Jane; Kendrick, Tina; Berry, Andrew

    2015-09-01

    Time-critical neurosurgical conditions require urgent operative treatment to prevent death or neurological deficits. In New South Wales/Australian Capital Territory patients' distance from neurosurgical care is often great, presenting a challenge in achieving timely care for patients with acute neurosurgical conditions. A protocol was developed to facilitate consultant neurosurgery locally. Children with acute, time-critical neurosurgical emergencies underwent operations in hospitals that do not normally offer neurosurgery. The authors describe the developed protocol, the outcome of its use, and the lessons learned in the 9 initial cases where the protocol has been used. Three cases are discussed in detail. Nine children were treated by a neurosurgeon at 5 rural hospitals, and 2 children were treated at a smaller metropolitan hospital. Road ambulance, fixed wing aircraft, and medical helicopters were used to transport the Newborn and Paediatric Emergency Transport Service (NETS) team, neurosurgeon, and patients. In each case, the time to definitive neurosurgical intervention was significantly reduced. The median interval from triage at the initial hospital to surgical start time was 3:55 hours, (interquartile range [IQR] 03:29-05:20 hours). The median distance traveled to reach a patient was 232 km (range 23-637 km). The median interval from the initial NETS call requesting patient retrieval to surgical start time was 3:15 hours (IQR 00:47-03:37 hours). The estimated median "time saved" was approximately 3:00 hours (IQR 1:44-3:15 hours) compared with the travel time to retrieve the child to the tertiary center: 8:31 hours (IQR 6:56-10:08 hours). Remote urgent neurosurgical interventions can be performed safely and effectively. This practice is relevant to countries where distance limits urgent access for patients to tertiary pediatric care. This practice is lifesaving for some children with head injuries and other acute neurosurgical conditions.

  7. Spinal neurosurgery with the head-mounted "Varioscope" microscope.

    PubMed

    Kuchta, J; Simons, P

    2009-05-01

    We present a preliminary report on the intra-operative use of a head-mounted microscope ("Varioscope" Leica HM500) in spinal neurosurgery. The Varioscope is a dynamic microscope mounted on a head-set. It weights 297 g and measures 73 x 120 x 63 mm (length x width x height). It offers an infinitely variable range of magnification from 3.6x to 7.2x. The working distance ranges from 300 to 600 mm. The field of view varies between 30-144 mm, depending on the selected enlargement factor and the working distance. In addition to the zoom function, the device offers a focus function (automatic or on demand). The optical elements for focus and zoom are located in two separate tubes which are mounted on a middle section containing the mechanical components as well as the receiver unit for the focussing elements. The lenses are adjusted by means of motor-driven push/pull cables. The autofocus works well in larger operative fields and a working distance between 30 and 60 cm. Nevertheless, when used in today's "keyhole" approaches, the autofocus is not helpful when operating in deep structures. Based on the satisfactory results achieved in our series, we can recommend the Varioscope, especially when no stationary microscope is available. The portable device can be packed in a suitcase and can travel with the consultant microsurgeon to different hospitals and distant units. The built-in video camera is ideal for patients, staff, assistant surgeons, and student education with real-time video monitoring of procedures from the microsurgeon's perspective. For daily microsurgery, we felt more comfortable with fixed, stationary operating microscopes.

  8. Optimizing Experimental Design for Comparing Models of Brain Function

    PubMed Central

    Daunizeau, Jean; Preuschoff, Kerstin; Friston, Karl; Stephan, Klaas

    2011-01-01

    This article presents the first attempt to formalize the optimization of experimental design with the aim of comparing models of brain function based on neuroimaging data. We demonstrate our approach in the context of Dynamic Causal Modelling (DCM), which relates experimental manipulations to observed network dynamics (via hidden neuronal states) and provides an inference framework for selecting among candidate models. Here, we show how to optimize the sensitivity of model selection by choosing among experimental designs according to their respective model selection accuracy. Using Bayesian decision theory, we (i) derive the Laplace-Chernoff risk for model selection, (ii) disclose its relationship with classical design optimality criteria and (iii) assess its sensitivity to basic modelling assumptions. We then evaluate the approach when identifying brain networks using DCM. Monte-Carlo simulations and empirical analyses of fMRI data from a simple bimanual motor task in humans serve to demonstrate the relationship between network identification and the optimal experimental design. For example, we show that deciding whether there is a feedback connection requires shorter epoch durations, relative to asking whether there is experimentally induced change in a connection that is known to be present. Finally, we discuss limitations and potential extensions of this work. PMID:22125485

  9. History of Neurosurgery at Postgraduate Institute of Medical Education and Research, Chandigarh.

    PubMed

    Gupta, Sunil K; Mukherjee, Kanchan K; Chhabra, Rajesh; Tripathi, Manjul

    2017-01-01

    The Department of Neurosurgery started functioning at the Postgraduate Institute of Medical Education and Research, Chandigarh in 1962 with the joining of Dr. Gulati. The department provides neurosurgical services primarily to the people of Chandigarh, Punjab, Haryana, Himachal Pradesh, Jammu and Kashmir as well as the neighbouring areas of Rajasthan, Uttar Pradesh and Uttarakhand. The infrastructure and subspecialties have been developed over the last 5 decades by the dedicated and tireless efforts of the faculty and residents. We attempt to chronicle the contributions of those who have served the department in the past.

  10. Localization accuracy of AC-PC line and functional pallidal target using BRW stereotactic implementation system and axial CT scanning. An experimental study.

    PubMed

    Rampini, P; Egidi, M; Zavanone, M; Orsi, M; Farabola, M; Sina, C

    1998-12-01

    Ventriculography is still considered an unavoidable step for functional target localization, even though this method is invasive and requires stereotactic rooms, orthogonal frames, and parallax-free X-ray equipment. In this experimental study, the authors investigated the feasibility of performing stereotactic lesions using a conventional, widely employed frame, such as the Brown-Roberts-Wells (BRW) apparatus, and computerized axial tomography (CAT) imaging. Five ex vivo models consisting of cadaveric brains enclose in a plastic shell were fixed in a BRW frame. A simple BRW implementation was used to ensure more symmetrical placement of the basal ring. Two-millimeter plastic balls were inserted at the level of the anterior (AC) and posterior commissures (PC) and at the target in the pallidus. Their final position was measured on the anatomical specimens and compared with Schaltenbrand Atlas maps. The error in estimating the length of the intercommissural line ranged from 0.5 mm to 2.0 mm, with a maximum backward angulation of four degrees in predicting the AC-PC plane. Upon dissection, in four out of five cases, the balls were found within the area of the pallidus defined by Laitinen for posteroventral pallidotomy. The authors conclude that anatomical identification of the AC-PC line and the pallidus target, using the BRW stereotactic system and CAT axial images alone offers sufficient accuracy. They suggest that functional neurosurgery for movement disorders could be safely and successfully carried out without ventriculography if neurophysiological monitoring is also employed.

  11. An assessment of academic productivity in pediatric neurosurgery.

    PubMed

    Kalra, Ricky R; Kestle, John R W

    2013-09-01

    Various bibliometric indices are now commonly used to assess academic productivity in medicine. Some evidence suggests that these measures are specific to subspecialty areas. The authors' goal was to measure the h index of academic pediatric neurosurgeons and compare it with previously reported results for academic neurosurgeons in general. Programs with an Accreditation Council for Pediatric Neurosurgery Fellowships-approved fellowship were identified, and the h and g indices of each of their surgeons were calculated. These were correlated with academic rank and compared with published literature on academic neurosurgical departments. Seventy-two pediatric neurosurgeons had a mean h index of 16.6 and a mean g index of 29.5. Both indices increased with progressive academic rank. The rank-specific mean index for academic pediatric neurosurgeons was similar to that of neurosurgeons from academic departments in general. Overall, the authors conclude that the h index metric is a reasonable measure of academic productivity in the pediatric neurosurgery arena that provides a robust measure of an individual's contribution to the pediatric neurosurgery literature. Like its counterpart in neurosurgery in general, the h index for pediatric neurosurgeons correlates with institutional rank. The h index calculation also reveals the productivity of the pediatric neurosurgeons to be on par with the productivity of neurosurgeons in general.

  12. In touch with robotics: neurosurgery for the future.

    PubMed

    Nathoo, Narendra; Cavuşoğlu, M Cenk; Vogelbaum, Michael A; Barnett, Gene H

    2005-03-01

    The introduction of multiple front-end technologies during the past quarter century has generated an emerging futurism for the discipline of neurological surgery. Driven primarily by synergistic developments in science and engineering, neurosurgery has always managed to harness the potential of the latest technical developments. Robotics represents one such technology. Progress in development of this technology has resulted in new uses for robotic devices in our discipline, which are accompanied by new potential dangers and inherent risks. The recent surge in robot-assisted interventions in other disciplines suggests that this technology may be considered one of a spectrum of frontier technologies poised to fuel the development of neurosurgery and consolidate the era of minimalism. On a more practical level, if the introduction of robotics in neurosurgery proves beneficial, neurosurgeons will need to become facile with this technology and learn to harness its potential so that the best surgical results may be achieved in the least invasive manner. This article reviews the role of robotic technology in the context of neurosurgery.

  13. Ottoman surgical treatises and their influences on modern neurosurgery in Turkey.

    PubMed

    Er, Uygur; Pamir, M Necmettin

    2013-12-01

    To introduce the authors of 6 prominent Ottoman surgical treatises, to present the chapters that relate to present-day neurosurgery, and to discuss their influence on the establishment of modern Turkish neurosurgery. Neurosurgery-related chapters of 6 prominent Ottoman surgical treatises and their role i the establishment of modern neurosurgery in Turkey are discussed. Neurosurgery-related chapters of "Hulasa-i Tıbb" by Surgeon Mesud (Summary of Medicine), "Cerrahhiyet-al Haniyye" by Şerefeddin Sabuncuoğlu (Imperial Surgery), "Cerrahname" by an unknown author (Surgical Treatise), "Ala'im-i Cerrahin" by Surgeon Ibrahim (Wonders of Surgeons) "Cerrahname" by Ali Munşi of Bursa (Surgical Treatise), and "The law of surgeons" by Şanizade Ataullah Mehmed Efendi (Kanun-al Cerrahin) were analyzed. These treatises, including sections on neurosurgery-related topics, were important influences on the establishment of contemporary neurosurgery in modern Turkey. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Experimental Phase Functions of Millimeter-sized Cosmic Dust Grains

    NASA Astrophysics Data System (ADS)

    Muñoz, O.; Moreno, F.; Vargas-Martín, F.; Guirado, D.; Escobar-Cerezo, J.; Min, M.; Hovenier, J. W.

    2017-09-01

    We present the experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz, and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing properties. The measurements are performed at 527 nm covering the scattering angle range from 3° to 170°. The measured phase functions show two well-defined regions: (i) soft forward peaks and (ii) a continuous increase with the scattering angle at side- and back-scattering regions. This behavior at side- and back-scattering regions is in agreement with the observed phase functions of the Fomalhaut and HR 4796A dust rings. Further computations and measurements (including polarization) for millimeter-sized grains are needed to draw some conclusions about the fluffy or compact structure of the dust grains.

  15. Experimental design for functional MRI of scene memory encoding.

    PubMed

    Narayan, Veena M; Kimberg, Daniel Y; Tang, Kathy Z; Detre, John A

    2005-03-01

    The use of functional imaging to identify encoding-related areas in the medial temporal lobe has previously been explored for presurgical evaluation in patients with temporal lobe epilepsy. Optimizing sensitivity in such paradigms is critical for the reliable detection of regions most closely engaged in memory encoding. A variety of experimental designs have been used to detect encoding-related activity, including blocked, sparse event-related, and rapid event-related designs. Although blocked designs are generally more sensitive than event-related designs, design and analysis advantages could potentially overcome this difference. In the present study, we directly contrast different experimental designs in terms of the intensity, extent, and lateralization of activation detected in healthy subjects. Our results suggest that although improved design augments the sensitivity of event-related designs, these benefits are not sufficient to overcome the sensitivity advantages of traditional blocked designs.

  16. Randomized controlled trials and neurosurgery: the ideal fit or should alternative methodologies be considered?

    PubMed

    Mansouri, Alireza; Cooper, Benjamin; Shin, Samuel M; Kondziolka, Douglas

    2016-02-01

    Randomized-controlled trials (RCTs) are advocated to provide high-level medical evidence. However, in neurosurgery, there are barriers to conducting RCTs. The authors of this study sought to analyze the quality of neurosurgical RCTs since 2000 to determine the adequacy of their design and reporting. A search of the MEDLINE and EMBASE databases (2000-2014) was conducted. The medical subject heading (MeSH) terms used in the search included: "neurosurgery" OR "neurosurgical procedure," "brain neoplasms," "infarction" and "decompression," "carotid stenosis," "cerebral hemorrhage," and "spinal fusion." These studies were limited to RCTs, in humans, and in the English language. The Consolidated Standards for Reporting of Trials (CONSORT) and Jadad scales were used to assess the quality of RCT design and reporting. The standardized median times cited (median citations divided by years since publication) were used to assess impact. A pragmatic-explanatory continuum indicator summary-based scale was used to assess the design of the studies as primarily pragmatic or explanatory. Sixty-one articles were identified, and the following subspecialties were the most common: vascular (23, 37%), followed by functional neurosurgery and neurooncology (both 13, 21%). The following nations were the primary leaders in RCTs: US (25 studies, 41%), Germany (8 studies, 13%), and the United Kingdom (7 studies, 11%). Median sample size was 100 (interquartile range [IQR] 41.5-279). The majority of the studies (40, 66%) had pragmatic objectives. The median number of times cited overall was 69 (IQR 20.5-193). The combined median CONSORT score was 36 (IQR 27.5-39). Blinding was most deficiently reported. Other areas with a relatively low quality of reporting were sample size calculation (34.2% of surgical, 38.5% of drug, and 20% of device studies), allocation concealment (28.9% of surgical, 23.1% of drug, and 50% of device studies), and protocol implementation (18.4% of surgical, 23% of drug, and

  17. Thin-film electroencephalographic electrodes using multi-walled carbon nanotubes are effective for neurosurgery.

    PubMed

    Awara, Kousuke; Kitai, Ryuhei; Isozaki, Makoto; Neishi, Hiroyuki; Kikuta, Kenichiro; Fushisato, Naoki; Kawamoto, Akira

    2014-12-15

    Intraoperative morphological and functional monitoring is essential for safe neurosurgery. Functional monitoring is based on electroencephalography (EEG), which uses silver electrodes. However, these electrodes generate metal artifacts as silver blocks X-rays, creating white radial lines on computed tomography (CT) images during surgery. Thick electrodes interfere with surgical procedures. Thus, thinner and lighter electrodes are ideal for intraoperative use. The authors developed thin brain electrodes using carbon nanotubes that were formed into thin sheets and connected to electrical wires. The nanotube sheets were soft and fitted the curve of the head very well. When attached to the head using paste, the impedance of the newly developed electrodes was 5 kΩ or lower, which was similar to that of conventional metal electrodes. These electrodes can be used in combination with intraoperative CT, magnetic resonance imaging (MRI), or cerebral angiography. Somatosensory-evoked potentials, auditory brainstem responses, and visually evoked potentials were clearly identified in ten volunteers. The electrodes, without any artifacts that distort images, did not interfere with X-rays, CT, or MR images. They also did not cause skin damage. Carbon nanotube electrodes may be ideal for neurosurgery.

  18. Experimental functional analysis of aggression in children with Angelman syndrome.

    PubMed

    Strachan, Rachel; Shaw, Rebecca; Burrow, Caroline; Horsler, Kate; Allen, Debbie; Oliver, Chris

    2009-01-01

    Kinship theory suggests that genomic imprinting could account for phenotypic behaviors that increase (in the case of Angelman syndrome) or decrease (for Prader-Willi syndrome) the drive to access social resources (adult contact) depending on the imprinting parent-of-origin. Difficult to manage behaviors, such as aggression that is common in Angelman syndrome, could serve the function of increasing social interaction. We hypothesise that the commonly reported aggressive behavior in children with Angelman syndrome will be attention maintained. Experimental functional analysis was carried out with twelve children with Angelman syndrome caused by either a deletion (n=10) or uniparental disomy (n=2). The relative increase and decrease of aggressive behaviors was observed in response to experimentally manipulated levels of adult attention and demand. Laughing and smiling, crying and frowning, and physical initiation with an adult were also measured. Aggression was seen in ten of the twelve children. One child evidenced a pattern of aggression across conditions consistent with maintenance by attention, three children showed higher levels of aggression during social interaction and two children showed escape motivated aggression. With the exception of one child the results did not confirm the hypothesis. However, the pattern of increased aggression in the high social contact condition combined with evidence of positive affect during this condition suggests aggression may serve to both maintain and initiate social contact and this interpretation is consistent with previous research. The negative results may also have been influenced by the age of the children and the low levels of observed aggression.

  19. Impairment of cardiac function and energetics in experimental renal failure.

    PubMed Central

    Raine, A E; Seymour, A M; Roberts, A F; Radda, G K; Ledingham, J G

    1993-01-01

    Cardiac function and energetics in experimental renal failure in the rat (5/6 nephrectomy) have been investigated by means of an isolated perfused working heart preparation and an isometric Langendorff preparation using 31P nuclear magnetic resonance (31P NMR). 4 wk after nephrectomy cardiac output of isolated hearts perfused with Krebs-Henseleit buffer was significantly lower (P < 0.0001) at all levels of preload and afterload in the renal failure groups than in the pair-fed sham operated control group. In control hearts, cardiac output increased with increases in perfusate calcium from 0.73 to 5.61 mmol/liter whereas uremic hearts failed in high calcium perfusate. Collection of 31P NMR spectra from hearts of renal failure and control animals during 30 min normoxic Langendorff perfusion showed that basal phosphocreatine was reduced by 32% to 4.7 mumol/g wet wt (P < 0.01) and the phosphocreatine to ATP ratio was reduced by 32% (P < 0.01) in uremic hearts. During low flow ischemia, there was a substantial decrease in phosphocreatine in the uremic hearts and an accompanying marked increase in release of inosine into the coronary effluent (14.9 vs 6.1 microM, P < 0.01). We conclude that cardiac function is impaired in experimental renal failure, in association with abnormal cardiac energetics and increased susceptibility to ischemic damage. Disordered myocardial calcium utilization may contribute to these derangements. PMID:8254048

  20. Experimental hydrodynamics of fish locomotion: functional insights from wake visualization.

    PubMed

    Drucker, Eliot G; Lauder, George V

    2002-04-01

    Despite enormous progress during the last twenty years in understanding the mechanistic basis of aquatic animal propulsion-a task involving the construction of a substantial data base on patterns of fin and body kinematics and locomotor muscle function-there remains a key area in which biologists have little information: the relationship between propulsor activity and water movement in the wake. How is internal muscular force translated into external force exerted on the water? What is the pattern of fluid force production by different fish fins (e.g., pectoral, caudal, dorsal) and how does swimming force vary with speed and among species? These types of questions have received considerable attention in analyses of terrestrial locomotion where force output by limbs can be measured directly with force plates. But how can forces exerted by animals moving through fluid be measured? The advent of digital particle image velocimetry (DPIV) has provided an experimental hydrodynamic approach for quantifying the locomotor forces of freely moving animals in fluids, and has resulted in significant new insights into the mechanisms of fish propulsion. In this paper we present ten "lessons learned" from the application of DPIV to problems of fish locomotion over the last five years. (1) Three-dimensional DPIV analysis is critical for reconstructing wake geometry. (2) DPIV analysis reveals the orientation of locomotor reaction forces. (3) DPIV analysis allows calculation of the magnitude of locomotor forces. (4) Swimming speed can have a major impact on wake structure. (5) DPIV can reveal interspecific differences in vortex wake morphology. (6) DPIV analysis can provide new insights into the limits to locomotor performance. (7) DPIV demonstrates the functional versatility of fish fins. (8) DPIV reveals hydrodynamic force partitioning among fins. (9) DPIV shows that wake interaction among fins may enhance thrust production. (10) Experimental hydrodynamic analysis can provide

  1. [Operative neurosurgery: personal view and historical backgrounds (2) acoustic neurinoma].

    PubMed

    Yonekawa, Yasuhiro

    2006-12-01

    Microsurgical removal of acoustic neurinoma is still one of the challenging topics in neurosurgery in spite of the development of Gamma-knife or radiosurgery, with which small and moderate sized tumors can be treated. Surgical technique necessitates more expertise in dealing with larger tumors. In this report ongoing microsurgical standard technique for removal of acoustic neurinomas of approx. 3 cm (extrameatal) in diameter is presented along with its historical backgrounds and literature review with reported techniques used by experienced neurosurgeons. 1) Standard sitting position with head turned (30) and flexed (20) head, and not semisitting position. 2) retromastoid retrosigmoid osteoplastic craniotomy following a linear incision. Special mention is made on how to manage the air embolism inherent to the sitting position in which the use of fibrin glue to seal the air entrance is presented along with early detection. 3) Intracapsular enucleation after the dural incision and retraction of the biventer lobule with special emphasis on the infrequent anatomical course of the facial and vestibulocochlear nerves on the posterior wall of neurinomas. 4) Localizing the facial nerve and vestibulocochlear nerve at the pontine side, so that decision of preserving or sacrificing the latter in the course of surgery can be made from the viewpoint of hearing preservation and concentrate on facial nerve function. 5) Drilling away of the posterior meatal lip in which sufficient drilling away should be performed to minimize opening of the posterior semicircular canal and that of mastoid cells. Complete sealing of either is necessary to prevent hearing loss or CSF rhinorrhoe. 6) Reduction of remaining tumor-capsule volume by sharp dissection or bipolar cutting, using intraoperative EMG-stimulation which identifies the presence of flattened facial nerve fibers on the capsule. Presence tiny remnant of the tumor capsule attached to the nerve bundles just before the entrance of

  2. The legacy of nanotechnology: revolution and prospects in neurosurgery.

    PubMed

    Khawaja, Ayaz Mahmood

    2011-01-01

    Nanotechnology has been an ever-growing field since the discovery of carbon fullerenes, and is being assimilated progressively into a variety of other disciplines including medical science. The association with neurosurgery had initially been less well characterized compared to other organ systems, but has recently offered promising future potential for a wide range of utilities including new therapeutic options for Glioblastoma Multiforme, neurprotection against oxidative stress, nerve nanorepair, nanodiagnosis of Alzheimer's disease, nanoimaging with nanoparticles and quantum dots, nanomanipulation of CNS with surgical nanobots, and nanoneuromodulation with nanofibres & nanowires. This article examines such potentials as well as others, of the utility of nanotechnology in Neurosurgery. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  3. A Bosphorus submarine passage and the reinvention of neurosurgery.

    PubMed

    Apuzzo, Michael L J; Pagán, Veronica M; Faccio, Rodrick; Liu, Charles Y

    2013-01-01

    One of the major themes characterizing the emergence of modern neurosurgery has been the concept of technology transfer and the application of a broad spectrum of revolutionary elements of technology from both physical and biological science. These transference applications are now apparent in modern neurosurgery as it is practiced on all continents of the globe. More than 3 decades ago, these ideas that now have come to fruition were in states of formulation. This article describes and further documents one such fertile cauldron of ideas and practical realities--the United States Navy Nuclear Submarine Service and its role and affect on the life and professional career of an academic neurosurgeon who was active in areas of progress as modernity was established for the early 21st century.

  4. The evolving role of the nurse practitioner in neurosurgery.

    PubMed

    Rimel, R W; Langfitt, T W

    1980-12-01

    The authors examine the many important roles for the nurse practitioner in neurosurgery, including patient care in academic departments and private practice, and research and scholarship. The responsibilities of nurse practitioners in a hospital can be varied: they may take some responsibility for all patients on the neurosurgery service, or their assignment may be more specific, such as to the intensive care unit; or they may be assigned to all patients with a specified neurosurgical disorder, such as head injury of intractable pain. Nurse practitioners can become coordinators of clinical research programs, with responsibility for collecting and collating the data and assisting in data analysis and manuscript preparation. Detailed clinical protocols must be developed for nurse practitioners, and those protocols then become the basis for their employment and legal status. Licensure requirements vary greatly among states, and are continuing to change.

  5. Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello Enrico; Schiariti, Marco P.; Grana, Chiara M.; Ferrari, Mahila; Cremonesi, Marta; Boschi, Federico

    2016-05-01

    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of Y90-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f/0.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery.

  6. Development of an MRI-compatible needle insertion manipulator for stereotactic neurosurgery.

    PubMed

    Masamune, K; Kobayashi, E; Masutani, Y; Suzuki, M; Dohi, T; Iseki, H; Takakura, K

    1995-01-01

    A variety of medical robots for stereotactic neurosurgery has been developed in recent years. Almost of all these robots use computed tomography (CT) to scan the brain of the patient before and during surgery. Currently, we are developing a needle insertion manipulator for magnetic resonance imaging (MRI)-guided neurosurgery. MRI techniques, including MRI angiography and functional MRI, are attractive for the development of interventional MRI therapies and operations. If a robot were available, these therapies would be minimally invasive, with more accurate guidance than is possible with current CT-guided systems. Actuation of a robot in an MRI environment is difficult because of the presence of strong magnetic fields. Therefore, the robot must be constructed of nonmagnetic materials. The system frame was manufactured using polyethylene terephthalate (PET) and was actuated using ultrasonic motors. Accuracy-evaluation procedures and phantom tests have been performed. The total accuracy of the system was approximately 3.0 mm. No artifacts caused by the manipulator were observed in the images.

  7. [The history of Spanish neurosurgery: the Valencian school: J.J. Barcia Goyanes].

    PubMed

    Barcia-Mariño, Carlos; Rodríguez-Mena, Ruben

    2013-01-01

    Professor Juan José Barcia-Goyanes started neurosurgical practice from anatomy and neuropsychiatry in response to a vacancy at a department known as "Nervous diseases", in 1931 at Hospital General in Valencia, Spain. Since the first intervention, based on the methods and surgical instruments already used in Europe and the U.S.A., the neurosurgical practice became the mainstay of the department, from which other auxiliary specialties emerged, such as neuroradiology, neurophysiology, neuropathology and also new techniques such as stereotactic surgery, functional neurosurgery and palencephalography. This year, the department celebrates its 80th anniversary. The broad spectrum of Prof. Barcia's scientific work included fields like neurology, neurosurgery and psychiatry, as well as anthropology, medical thought, history of medicine, morphology and history of anatomical language in his work "Onomatologica anatomica nova", in addition to an interesting poetic work. He was a founding member of the Luso-Spanish Neurosurgical Society and the Neurosurgical Society of Levante. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  8. Straight trajectory planning for keyhole neurosurgery in sheep with automatic brain structures segmentation

    NASA Astrophysics Data System (ADS)

    Favaro, Alberto; Lad, Akash; Formenti, Davide; Zani, Davide Danilo; De Momi, Elena

    2017-03-01

    In a translational neuroscience/neurosurgery perspective, sheep are considered good candidates to study because of the similarity between their brain and the human one. Automatic planning systems for safe keyhole neurosurgery maximize the probe/catheter distance from vessels and risky structures. This work consists in the development of a trajectories planner for straight catheters placement intended to be used for investigating the drug diffusivity mechanisms in sheep brain. Automatic brain segmentation of gray matter, white matter and cerebrospinal fluid is achieved using an online available sheep atlas. Ventricles, midbrain and cerebellum segmentation have been also carried out. The veterinary surgeon is asked to select a target point within the white matter to be reached by the probe and to define an entry area on the brain cortex. To mitigate the risk of hemorrhage during the insertion process, which can prevent the success of the insertion procedure, the trajectory planner performs a curvature analysis of the brain cortex and wipes out from the poll of possible entry points the sulci, as part of brain cortex where superficial blood vessels are naturally located. A limited set of trajectories is then computed and presented to the surgeon, satisfying an optimality criteria based on a cost function which considers the distance from critical brain areas and the whole trajectory length. The planner proved to be effective in defining rectilinear trajectories accounting for the safety constraints determined by the brain morphology. It also demonstrated a short computational time and good capability in segmenting gyri and sulci surfaces.

  9. Josef Klingler's models of white matter tracts: influences on neuroanatomy, neurosurgery, and neuroimaging.

    PubMed

    Agrawal, Abhishek; Kapfhammer, Josef P; Kress, Annetrudi; Wichers, Hermann; Deep, Aman; Feindel, William; Sonntag, Volker K H; Spetzler, Robert F; Preul, Mark C

    2011-08-01

    During the 1930s, white matter tracts began to assume relevance for neurosurgery, especially after Cajal's work. In many reviews of white matter neurobiology, the seminal contributions of Josef Klingler (1888-1963) and their neurological applications have been overlooked. In 1934 at the University of Basel under Eugen Ludwig, Klingler developed a new method of dissection based on a freezing technique for brain tissue that eloquently revealed the white matter tracts. Klingler worked with anatomists, surgeons, and other scientists, and his models and dissections of white matter tracts remain arguably the most elegant ever created. He stressed 3-dimensional anatomic relationships and laid the foundation for defining mesial temporal, limbic, insular, and thalamic fiber and functional relationships and contributed to the potential of stereotactic neurosurgery. Around 1947, Klingler was part of a Swiss-German group that independently performed the first stereotactic thalamotomies, basing their targeting and logic on Klingler's white matter studies, describing various applications of stereotaxy and showing Klingler's work integrated into a craniocerebral topographic system for targeting with external localization of eloquent brain structures and stimulation of deep thalamic nuclei. Klingler's work has received renewed interest because it is applicable for correlating the results of the fiber-mapping paradigms from diffusion tensor imaging to actual anatomic evidence. Although others have described white matter tracts, none have had as much practical impact on neuroscience as Klinger's work. More importantly, Josef Klingler was an encouraging mentor, influencing neurosurgeons, neuroscientists, and brain imaging for more than three quarters of a century.

  10. Crystal structure solution from experimentally determined atomic pair distribution functions

    SciTech Connect

    Juhas, P.; Granlund, L.; Gujarathi, S.R.; Duxbury, P.M.; Billinge, S.J.L.

    2010-05-25

    An extension of the Liga algorithm for structure solution from atomic pair distribution functions (PDFs), to handle periodic crystal structures with multiple elements in the unit cell, is described. The procedure is performed in three separate steps. First, pair distances are extracted from the experimental PDF. In the second step the Liga algorithm is used to find unit-cell sites consistent with these pair distances. Finally, the atom species are assigned over the cell sites by minimizing the overlap of their empirical atomic radii. The procedure has been demonstrated on synchrotron X-ray PDF data from 16 test samples. The structure solution was successful for 14 samples, including cases with enlarged supercells. The algorithm success rate and the reasons for the failed cases are discussed, together with enhancements that should improve its convergence and usability.

  11. Neurosurgery simulation in residency training: feasibility, cost, and educational benefit.

    PubMed

    Gasco, Jaime; Holbrook, Thomas J; Patel, Achal; Smith, Adrian; Paulson, David; Muns, Alan; Desai, Sohum; Moisi, Marc; Kuo, Yong-Fan; Macdonald, Bart; Ortega-Barnett, Juan; Patterson, Joel T

    2013-10-01

    The effort required to introduce simulation in neurosurgery academic programs and the benefits perceived by residents have not been systematically assessed. To create a neurosurgery simulation curriculum encompassing basic and advanced skills, cadaveric dissection, cranial and spine surgery simulation, and endovascular and computerized haptic training. A curriculum with 68 core exercises per academic year was distributed in individualized sets of 30 simulations to 6 neurosurgery residents. The total number of procedures completed during the academic year was set to 180. The curriculum includes 79 simulations with physical models, 57 cadaver dissections, and 44 haptic/computerized sessions. Likert-type evaluations regarding self-perceived performance were completed after each exercise. Subject identification was blinded to junior (postgraduate years 1-3) or senior resident (postgraduate years 4-6). Wilcoxon rank testing was used to detect differences within and between groups. One hundred eighty procedures and surveys were analyzed. Junior residents reported proficiency improvements in 82% of simulations performed (P < .001). Senior residents reported improvement in 42.5% of simulations (P < .001). Cadaver simulations accrued the highest reported benefit (71.5%; P < .001), followed by physical simulators (63.8%; P < .001) and haptic/computerized (59.1; P < .001). Initial cost is $341,978.00, with $27,876.36 for annual operational expenses. The systematic implementation of a simulation curriculum in a neurosurgery training program is feasible, is favorably regarded, and has a positive impact on trainees of all levels, particularly in junior years. All simulation forms, cadaver, physical, and haptic/computerized, have a role in different stages of learning and should be considered in the development of an educational simulation program.

  12. Application of the Chick Embryo Chorioallantoic Membrane in Neurosurgery Disease

    PubMed Central

    Yuan, Yong-Jie; Xu, Kan; Wu, Wei; Luo, Qi; Yu, Jin-Lu

    2014-01-01

    The chick embryo chorioallantoic membrane (CAM) is a highly vascularized extraembryonic membrane. Because of its ease of accessibility, extensive vascularization and immunodeficient environment, the CAM has been broadly used in the oncology, biology, pharmacy, and tissue regeneration research. The present review summarizes the application of the CAM in neurosurgery disease research. We focused on the use of the CAM as an assay for the research of glioma, vascular anomalies, Moyamoya Disease, and the blood-brain barrier. PMID:25419173

  13. Experimental investigations of the functional morphology of dragonfly wings

    NASA Astrophysics Data System (ADS)

    Rajabi, H.; Darvizeh, A.

    2013-08-01

    Nowadays, the importance of identifying the flight mechanisms of the dragonfly, as an inspiration for designing flapping wing vehicles, is well known. An experimental approach to understanding the complexities of insect wings as organs of flight could provide significant outcomes for design purposes. In this paper, a comprehensive investigation is carried out on the morphological and microstructural features of dragonfly wings. Scanning electron microscopy (SEM) and tensile testing are used to experimentally verify the functional roles of different parts of the wings. A number of SEM images of the elements of the wings, such as the nodus, leading edge, trailing edge, and vein sections, which play dominant roles in strengthening the whole structure, are presented. The results from the tensile tests indicate that the nodus might be the critical region of the wing that is subjected to high tensile stresses. Considering the patterns of the longitudinal corrugations of the wings obtained in this paper, it can be supposed that they increase the load-bearing capacity, giving the wings an ability to tolerate dynamic loading conditions. In addition, it is suggested that the longitudinal veins, along with the leading and trailing edges, are structural mechanisms that further improve fatigue resistance by providing higher fracture toughness, preventing crack propagation, and allowing the wings to sustain a significant amount of damage without loss of strength.

  14. Rigid, Variable-View Endoscope in Neurosurgery: First Intraoperative Experience.

    PubMed

    Ebner, Florian H; Roser, Florian; Roder, Constantin; Tatagiba, Marcos; Schuhmann, Martin U

    2015-08-01

    The endoscope became a highly valued visualization tool in neurosurgery. However, technical limitations caused by the rigidity of current standard endoscopes significantly decrease ergonomy in transcranial neurosurgery. Further technological developments will aid enlarging the surgical applicability. To evaluate the intraoperative features of a rigid variable-view endoscope in neurosurgery. We assessed a 4 mm rigid rod lens endoscope (EndoCAMeleon, Karl Storz, Tuttlingen, Germany) in the intraoperative setting. The device offers a variable angle of view from 15° to 90° in one plane. The endoscope was used in 3 cases (aneurysm clipping, vestibular schwannoma surgery, endoscopic third ventriculostomy) for inspection. Direct insertion of the device through the craniotomy/burr hole with the lowest angled view (15°) was always possible. Neurovascular structures crossing the access route could be visualized and avoided. This allowed a targeted positioning of the endoscope's tip in the operating field. Once the target point was reached, viewing direction was changed in one plane from 15° to 90° according to anatomic demands. As the endoscope's tip does not move while the lens is rotated, surrounding neurovascular structures are not at risk to be injured. However, turning of the lens-controlling wheel in proximity to delicate structures may be inconvenient. The rigid, variable-view endoscope has the potential to become an appreciated visualization tool in neuroendoscopy. The steerable lens enables a tremendous expansion of the visual field, resulting in higher efficiency for surgeons and increased safety for patients. © The Author(s) 2014.

  15. The history of neurosurgery at the University of Alabama at Birmingham.

    PubMed

    Foreman, Paul M; Markert, James M; Diethelm, Arnold G; Hadley, Mark N

    2014-10-01

    : The Division of Neurosurgery at the University of Alabama at Birmingham was formally founded in 1954 under the leadership of James Garber Galbraith. The following 60 years would see neurosurgery at the forefront of the development of a nationally recognized medical center in the heart of Birmingham, Alabama. The Department of Neurosurgery now employs 14 faculty members, performs more than 4500 neurosurgical procedures annually, is active in clinical and laboratory research, and boasts a contemporary, comprehensive residency training program.

  16. A technique to identify core journals for neurosurgery using citation scatter analysis and the Bradford distribution across neurosurgery journals.

    PubMed

    Madhugiri, Venkatesh S; Ambekar, Sudheer; Strom, Shane F; Nanda, Anil

    2013-11-01

    The volume of scientific literature doubles approximately every 7 years. The coverage of this literature provided by online compendia is variable and incomplete. It would hence be useful to identify "core" journals in any field and validate whether the h index and impact factor truly identify the core journals in every subject. The core journals in every medical specialty would be those that provide a current and comprehensive coverage of the science in that specialty. Identifying these journals would make it possible for individual physicians to keep abreast of research and clinical progress. The top 10 neurosurgical journals (on the basis of impact factor and h index) were selected. A database of all articles cited in the reference lists of papers published in issues of these journals published in the first quarter of 2012 was generated. The journals were ranked based on the number of papers cited from each. This citation rank list was compared with the h index and impact factor rank lists. The rank list was also examined to see if the concept of core journals could be validated for neurosurgical literature using Bradford's law. A total of 22,850 papers spread across 2522 journals were cited in neurosurgical literature over 3 months. Although the top 10 journals were the same, irrespective of ranking criterion (h index, impact factor, citation ranking), the 3 rank lists were not congruent. The top 25% of cited articles obeyed the Bradford distribution; beyond this, there was a zone of increased scatter. Six core journals were identified for neurosurgery. The core journals for neurosurgery were identified to be Journal of Neurosurgery, Neurosurgery, Spine, Acta Neurochirurgica, Stroke, and Journal of Neurotrauma. A list of core journals could similarly be generated for every subject. This would facilitate a focused reading to keep abreast of current knowledge. Collated across specialties, these journals could depict the current status of medical science.

  17. Network inference from functional experimental data (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Desrosiers, Patrick; Labrecque, Simon; Tremblay, Maxime; Bélanger, Mathieu; De Dorlodot, Bertrand; Côté, Daniel C.

    2016-03-01

    Functional connectivity maps of neuronal networks are critical tools to understand how neurons form circuits, how information is encoded and processed by neurons, how memory is shaped, and how these basic processes are altered under pathological conditions. Current light microscopy allows to observe calcium or electrical activity of thousands of neurons simultaneously, yet assessing comprehensive connectivity maps directly from such data remains a non-trivial analytical task. There exist simple statistical methods, such as cross-correlation and Granger causality, but they only detect linear interactions between neurons. Other more involved inference methods inspired by information theory, such as mutual information and transfer entropy, identify more accurately connections between neurons but also require more computational resources. We carried out a comparative study of common connectivity inference methods. The relative accuracy and computational cost of each method was determined via simulated fluorescence traces generated with realistic computational models of interacting neurons in networks of different topologies (clustered or non-clustered) and sizes (10-1000 neurons). To bridge the computational and experimental works, we observed the intracellular calcium activity of live hippocampal neuronal cultures infected with the fluorescent calcium marker GCaMP6f. The spontaneous activity of the networks, consisting of 50-100 neurons per field of view, was recorded from 20 to 50 Hz on a microscope controlled by a homemade software. We implemented all connectivity inference methods in the software, which rapidly loads calcium fluorescence movies, segments the images, extracts the fluorescence traces, and assesses the functional connections (with strengths and directions) between each pair of neurons. We used this software to assess, in real time, the functional connectivity from real calcium imaging data in basal conditions, under plasticity protocols, and epileptic

  18. Experimental nonalcoholic steatohepatitis compromises ureagenesis, an essential hepatic metabolic function.

    PubMed

    Thomsen, Karen Louise; Grønbæk, Henning; Glavind, Emilie; Hebbard, Lionel; Jessen, Niels; Clouston, Andrew; George, Jacob; Vilstrup, Hendrik

    2014-08-01

    Nonalcoholic steatohepatitis (NASH) is increasing in prevalence, yet its consequences for liver function are unknown. We studied ureagenesis, an essential metabolic liver function of importance for whole body nitrogen homeostasis, in a rodent model of diet-induced NASH. Rats were fed a high-fat, high-cholesterol diet for 4 and 16 wk, resulting in early and advanced experimental NASH, respectively. We examined the urea cycle enzyme mRNAs in liver tissue, the hepatocyte urea cycle enzyme proteins, and the in vivo capacity of urea-nitrogen synthesis (CUNS). Early NASH decreased all of the urea cycle mRNAs to an average of 60% and the ornithine transcarbamylase protein to 10%, whereas the CUNS remained unchanged. Advanced NASH further decreased the carbamoyl phosphate synthetase protein to 63% and, in addition, decreased the CUNS by 20% [from 5.65 ± 0.23 to 4.58 ± 0.30 μmol × (min × 100 g)(-1); P = 0.01]. Early NASH compromised the genes and enzyme proteins involved in ureagenesis, whereas advanced NASH resulted in a functional reduction in the capacity for ureagenesis. The pattern of urea cycle perturbations suggests a prevailing mitochondrial impairment by NASH. The decrease in CUNS has consequences for the ability of the body to adjust to changes in the requirements for nitrogen homeostasis e.g., at stressful events. NASH, thus, in terms of metabolic consequences, is not an innocuous lesion, and the manifestations of the damage seem to be a continuum with increasing disease severity.

  19. Multitrophic functional diversity predicts ecosystem functioning in experimental assemblages of estuarine consumers.

    PubMed

    Lefcheck, Jonathan S; Duffy, J Emmett

    2015-11-01

    The use of functional traits to explain how biodiversity affects ecosystem functioning has attracted intense interest, yet few studies have a priori altered functional diversity, especially in multitrophic communities. Here, we manipulated multivariate functional diversity of estuarine grazers and predators within multiple levels of species richness to test how species richness and functional diversity predicted ecosystem functioning in a multitrophic food web. Community functional diversity was a better predictor than species richness for the majority of ecosystem properties, based on generalized linear mixed-effects models. Combining inferences from eight traits into a single multivariate index increased prediction accuracy of these models relative to any individual trait. Structural equation modeling revealed that functional diversity of both grazers and predators was important in driving final biomass within trophic levels, with stronger effects observed for predators. We also show that different species drove different ecosystem responses, with evidence for both sampling effects and complementarity. Our study extends experimental investigations of functional trait diversity to a multilevel food web, and demonstrates that functional diversity can be more accurate and effective than species richness in predicting community biomass in a food web context.

  20. Bradford's law: identification of the core journals for neurosurgery and its subspecialties.

    PubMed

    Venable, Garrett T; Shepherd, Brandon A; Loftis, Christopher M; McClatchy, S Gray; Roberts, Mallory L; Fillinger, Meghan E; Tansey, James B; Klimo, Paul

    2016-02-01

    Bradford's law describes the scatter of citations for a given subject or field. It can be used to identify the most highly cited journals for a field or subject. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of neurosurgery and neurosurgical subspecialties. All original research publications from 2009 to 2013 were analyzed for the top 25 North American academic neurosurgeons from each subspecialty. The top 25 were chosen from a ranked career h-index list identified from previous studies. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals for each subspecialty. The databases were then combined to identify the core journals for all of academic neurosurgery. Using Bradford's verbal law with 4 zone models, the authors were able to identify the core journals of neurosurgery and its subspecialties. The journals found in the most highly cited first zone are presented here as the core journals. For neurosurgery as a whole, the core included the following journals: Journal of Neurosurgery, Neurosurgery, Spine, Stroke, Neurology, American Journal of Neuroradiology, International Journal of Radiation Oncology Biology Physics, and New England Journal of Medicine. The core journals for each subspecialty are presented in the manuscript. Bradford's law can be used to identify the core journals of neurosurgery and its subspecialties. The core journals vary for each neurosurgical subspecialty, but Journal of Neurosurgery and Neurosurgery are among the core journals for each neurosurgical subspecialty.

  1. Platelet Function During Hypothermia in Experimental Mock Circulation.

    PubMed

    Van Poucke, Sven; Stevens, Kris; Kicken, Cécile; Simons, Antoine; Marcus, Abraham; Lancé, Marcus

    2016-03-01

    for platelet stimulation using COL, this trend continues during temperature drop from 37°C to 32°C. LTA values using AA and TRAP demonstrate a considerable decline in platelet function throughout the experiment that was most pronounced after 24 h of circulation at 32°C. LTA values using ADP and COL further decline after rewarming. MEA ADP, ASPI, and COL identify platelet dysfunction patterns analogous with LTA, between the start of the mock circulation and the start of cooling. Except for MEA TRAP, this trend continues during temperature drop from 37°C to 32°C. MEA ASPI and ADP demonstrate a considerable decline in platelet function throughout the experiment, which was most pronounced after 24 h of circulation at 32°C. For MEA COL and TRAP, further decline in platelet function is observed after rewarming. This study quantitatively assessed the effect of temperature changes on platelet function during experimental mock circulation demonstrating a considerable decline in platelet function during hypothermia without uniform recovery of platelet function observed after rewarming.

  2. Experimental determination of wave function spread in Si inversion layers

    NASA Astrophysics Data System (ADS)

    Majumdar, Amlan

    2010-08-01

    We have experimentally determined the extent of wave function spread TQM in Si inversion layers on (100)-oriented surface in metal-oxide-semiconductor field-effect transistors (MOSFETs) using the back gate bias sensitivity of front gate threshold voltage of planar fully depleted silicon-on-insulator (SOI) MOSFETs. We show that the sum of TQM for large positive and negative F is an electrically determined value of the SOI thickness TSI. We find that the electric field dependence of TQM for electrons and holes is given by TQM˜F-0.4 and F-0.6, respectively, at high electric fields with TQM being larger for holes at a given F. Larger TQM for holes can be explained by the fact that holes have a smaller effective mass along the confinement direction than electrons in (100) Si. The field dependences of TQM are, however, not consistent with the results of variational calculations that assume single-subband occupancy and predict TQM˜F-1/3. The discrepancy likely indicates that the effects of multiple-subband occupation are significant at room temperature, especially for holes.

  3. Plumbagin suppresses dendritic cell functions and alleviates experimental autoimmune encephalomyelitis.

    PubMed

    Zhang, Kai; Ge, Zhenzhen; Da, Yurong; Wang, Dong; Liu, Ying; Xue, Zhenyi; Li, Yan; Li, Wen; Zhang, Lijuan; Wang, Huafeng; Zhang, Huan; Peng, Meiyu; Hao, Junwei; Yao, Zhi; Zhang, Rongxin

    2014-08-15

    Plumbagin (PL, 5-hydroxy-2-methyl-1,4-naphthoquinone) is a herbal compound derived from medicinal plants of the Droseraceae, Plumbaginaceae, Dioncophyllaceae, and Ancistrocladaceae families. Reports have shown that PL exerts immunomodulatory activity and may be a novel drug candidate for immune-related disease therapy. However, its effects on dendritic cells (DCs), the most potent antigen-presenting cells (APCs), remain unclear. In this study, we demonstrate that PL inhibits the differentiation, maturation, and function of human monocyte-derived DCs. PL can also restrict the expression of Th1- and Th17-polarizing cytokines in mDC. In addition, PL suppresses DCs both in vitro and in vivo, as demonstrated by its effects on the mouse DC line DC2.4 and mice with experimental autoimmune encephalomyelitis (EAE), respectively. Notably, PL ameliorated the clinical symptoms of EAE, including central nervous system (CNS) inflammation and demyelination. Our results demonstrate the immune suppressive and anti-inflammatory properties of PL via its effects on DCs and suggest that PL could be a potential treatment for DC-related autoimmune and inflammatory diseases.

  4. Critical Zone Experimental Design to Assess Soil Processes and Function

    NASA Astrophysics Data System (ADS)

    Banwart, Steve

    2010-05-01

    experimental design studies soil processes across the temporal evolution of the soil profile, from its formation on bare bedrock, through managed use as productive land to its degradation under longstanding pressures from intensive land use. To understand this conceptual life cycle of soil, we have selected 4 European field sites as Critical Zone Observatories. These are to provide data sets of soil parameters, processes and functions which will be incorporated into the mathematical models. The field sites are 1) the BigLink field station which is located in the chronosequence of the Damma Glacier forefield in alpine Switzerland and is established to study the initial stages of soil development on bedrock; 2) the Lysina Catchment in the Czech Republic which is representative of productive soils managed for intensive forestry, 3) the Fuchsenbigl Field Station in Austria which is an agricultural research site that is representative of productive soils managed as arable land and 4) the Koiliaris Catchment in Crete, Greece which represents degraded Mediterranean region soils, heavily impacted by centuries of intensive grazing and farming, under severe risk of desertification.

  5. The historical origin of the term "meningioma" and the rise of nationalistic neurosurgery.

    PubMed

    Barthélemy, Ernest Joseph; Sarkiss, Christopher A; Lee, James; Shrivastava, Raj K

    2016-11-01

    "tumeurs cancéreuses de la duremère," and the work of histopathologists, such as Hermann Lebert, who were influenced by Pasteur's germ theory and by Bernard's experimental medicine. The final development of the meningioma nomenclature corresponded to the rise of American neurosurgery as a formal academic discipline. This historical period of growth is chronicled in Cushing's text Meningiomas, and it set the scientific stage for the modern developments in meningioma research and surgery that are conducted and employed today.

  6. Highly cited publications in pediatric neurosurgery: part 2

    PubMed Central

    Khan, Nickalus R.; Auschwitz, Tyler; McAbee, Joseph H.; Boop, Frederick A.; Klimo, Paul

    2015-01-01

    Purpose Citation counting can be used to evaluate the impact an article has made on its discipline. This study characterizes the most cited articles related to clinical pediatric neurosurgery as of July 2013. Methods A list of search terms was computed using Thomson Reuters Web of Science® (WOS) to capture the 100 most cited articles in the overall literature and the top 50 articles from 2002 to 2012 related to clinical pediatric neurosurgery from non-dedicated pediatric neurosurgical journals. The following information was recorded for each article: number of authors, country of origin, citation count adjusted for number of years in print, topic, and level of evidence. Results The 100 most cited articles appeared in 44 journals. Publication dates ranged from 1986 to 2008; two were class 1 evidence, nine class 2, 26 class 3, and 52 class 4. Citations ranged from 90 to 321 (mean=131); average time-adjusted citation count was 10. The 50 most cited articles from 2002 to 2012 appeared in 31 journals; four were class 2 evidence, 15 class 3, and 21 class 4. Citations ranged from 68 to 245 (mean=103); average time-adjusted citation count was 13. Conclusion Overall, papers from non-pediatric neurosurgical journals had higher citation counts and improved level of evidence grades compared to articles from pediatric neurosurgical periodicals. An original paper related to clinical pediatric neurosurgery in a non-pediatric neurosurgical journal having a total citation count of 100–150 or more and an average citation count of 10–15 per year or more can be considered a high-impact publication. PMID:24113776

  7. Checklists in Neurosurgery to Decrease Preventable Medical Errors: A Review

    PubMed Central

    Enchev, Yavor

    2015-01-01

    Neurosurgery represents a zero tolerance environment for medical errors, especially preventable ones like all types of wrong site surgery, complications due to the incorrect positioning of patients for neurosurgical interventions and complications due to failure of the devices required for the specific procedure. Following the excellent and encouraging results of the safety checklists in intensive care medicine and in other surgical areas, the checklist was naturally introduced in neurosurgery. To date, the reported world experience with neurosurgical checklists is limited to 15 series with fewer than 20,000 cases in various neurosurgical areas. The purpose of this review was to study the reported neurosurgical checklists according to the following parameters: year of publication; country of origin; area of neurosurgery; type of neurosurgical procedure-elective or emergency; person in charge of the checklist completion; participants involved in completion; whether they prevented incorrect site surgery; whether they prevented complications due to incorrect positioning of the patients for neurosurgical interventions; whether they prevented complications due to failure of the devices required for the specific procedure; their specific aims; educational preparation and training; the time needed for checklist completion; study duration and phases; number of cases included; barriers to implementation; efforts to implementation; team appreciation; and safety outcomes. Based on this analysis, it could be concluded that neurosurgical checklists represent an efficient, reliable, cost-effective and time-saving tool for increasing patient safety and elevating the neurosurgeons’ self-confidence. Every neurosurgical department must develop its own neurosurgical checklist or adopt and modify an existing one according to its specific features and needs in an attempt to establish or develop its safety culture. The world, continental, regional and national neurosurgical societies

  8. Planning and Executing the Neurosurgery Boot Camp: The Bolivia Experience.

    PubMed

    Ament, Jared D; Kim, Timothy; Gold-Markel, Judah; Germano, Isabelle M; Dempsey, Robert; Weaver, John P; DiPatri, Arthur J; Andrews, Russell J; Sanchez, Mary; Hinojosa, Juan; Moser, Richard P; Glick, Roberta

    2017-08-01

    The neurosurgical boot camp has been fully incorporated into U.S. postgraduate education. This is the first implementation of the neurosurgical boot in a developing country. To advance neurosurgical education, we developed a similar boot camp program, in collaboration with Bolivian neurosurgeons, to determine its feasibility and effectiveness in an international setting. In a collective effort, the Bolivian Society for Neurosurgery, Foundation for International Education in Neurological Surgery, Solidarity Bridge, and University of Massachusetts organized and executed the first South American neurosurgical boot camp in Bolivia in 2015. Both U.S. and Bolivian faculty led didactic lectures followed by a practicum day using mannequins and simulators. South American residents and faculty were surveyed after the course to determine levels of enthusiasm and their perceived improvement in fund of knowledge and course effectiveness. Twenty-four neurosurgery residents from 5 South American countries participated. Average survey scores ranged between 4.2 and 4.9 out of 5. Five Bolivian neurosurgeons completed the survey with average scores of 4.5-5. This event allowed for Bolivian leaders in the field to unify around education, resulting in the formation of an institute to continue similar initiatives. Total cost was estimated at $40 000 USD; however, significant faculty, industry, and donor support helped offset this amount. The first South American neurosurgical boot camp had significant value and was well received in Bolivia. This humanitarian model provides a sustainable solution to education needs and should be expanded to other regions as a means for standardizing the core competencies in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Naval aviation and neurosurgery: traditions, commonalities, and lessons learned. The 2007 presidential address.

    PubMed

    Quest, Donald O

    2007-12-01

    In his presidential address to the American Association of Neurological Surgeons, the author recounts lessons he learned while training to be a Naval Aviator and later a neurosurgeon. He describes his life as an aviator and neurosurgeon, compares naval aviation and neurosurgery, and points out lessons that neurosurgery can learn from naval aviation.

  10. Publication misrepresentation among neurosurgery residency applicants: an increasing problem.

    PubMed

    Kistka, Heather M; Nayeri, Arash; Wang, Li; Dow, Jamie; Chandrasekhar, Rameela; Chambless, Lola B

    2016-01-01

    OBJECT Misrepresentation of scholarly achievements is a recognized phenomenon, well documented in numerous fields, yet the accuracy of reporting remains dependent on the honor principle. Therefore, honest self-reporting is of paramount importance to maintain scientific integrity in neurosurgery. The authors had observed a trend toward increasing numbers of publications among applicants for neurosurgery residency at Vanderbilt University and undertook this study to determine whether this change was a result of increased academic productivity, inflated reporting, or both. They also aimed to identify application variables associated with inaccurate citations. METHODS The authors retrospectively reviewed the residency applications submitted to their neurosurgery department in 2006 (n = 148) and 2012 (n = 194). The applications from 2006 were made via SF Match and those from 2012 were made using the Electronic Residency Application Service. Publications reported as "accepted" or "in press" were verified via online search of Google Scholar, PubMed, journal websites, and direct journal contact. Works were considered misrepresented if they did not exist, incorrectly listed the applicant as first author, or were incorrectly listed as peer reviewed or published in a printed journal rather than an online only or non-peer-reviewed publication. Demographic data were collected, including applicant sex, medical school ranking and country, advanced degrees, Alpha Omega Alpha membership, and USMLE Step 1 score. Zero-inflated negative binomial regression was used to identify predictors of misrepresentation. RESULTS Using univariate analysis, between 2006 and 2012 the percentage of applicants reporting published works increased significantly (47% vs 97%, p < 0.001). However, the percentage of applicants with misrepresentations (33% vs 45%) also increased. In 2012, applicants with a greater total of reported works (p < 0.001) and applicants from unranked US medical schools (those not

  11. 3D localization of ferromagnetic probes for small animal neurosurgery.

    PubMed

    Heinig, Maximilian; Schlaefer, Alexander; Schweikard, Achim

    2010-01-01

    We present the design, setup and results for a magnetic navigation system for small animal stereotactic neurosurgery. Our system tracks the position of thin (diameter 0.5 mm), magnetized ferromagnetic probes inserted into brains of small animals, e.g. rats, for electrophysiological recordings. It is used in combination with the spherical assistant for stereotactic surgery (SASSU) robot to obtain online feedback of the probe's position. Navigation is based only on the static magnetic field generated by the probes thus no external excitation or wires are needed.

  12. Automatic trajectory planning of DBS neurosurgery from multi-modal MRI datasets.

    PubMed

    Bériault, Silvain; Al Subaie, Fahd; Mok, Kelvin; Sadikot, Abbas F; Pike, G Bruce

    2011-01-01

    We propose an automated method for preoperative trajectory planning of deep brain stimulation image-guided neurosurgery. Our framework integrates multi-modal MRI analysis (T1w, SWI, TOF-MRA) to determine an optimal trajectory to DBS targets (subthalamic nuclei and globus pallidus interna) while avoiding critical brain structures for prevention of hemorrhages, loss of function and other complications. Results show that our method is well suited to aggregate many surgical constraints and allows the analysis of thousands of trajectories in less than 1/10th of the time for manual planning. Finally, a qualitative evaluation of computed trajectories resulted in the identification of potential new constraints, which are not addressed in the current literature, to better mimic the decision-making of the neurosurgeon during DBS planning.

  13. Dr. Lenke Horvath (1917-1991): Creator of Pediatric Neurosurgery in Romania.

    PubMed

    Mohan, Dumitru; Moisa, Horatiu Alexandru; Nica, Dan Aurel; Ciurea, Alexandru Vlad

    2016-04-01

    The development of neurosurgery as an independent specialty took place with great difficulty in Romania. In this respect, the most revered personalities are those of Professor Alexandru Moruzzi (1900-1957) (in Iasi) and Professor Dimitrie Bagdasar (1893-1946) (in Bucharest), who are the fathers of modern neurosurgery in Romania. Professor Bagdasar was schooled in Professor Harvey Cushing's clinic in Boston and is credited with creating the first completely independent neurosurgical unit in Romania. His legacy was carried on with honor by Professor Constantin Arseni (1912-1994), who, in 1975, tasked Dr. Lenke Horvath (1917-1991) with creating the first autonomous pediatric neurosurgery unit in Bucharest. This article is a small tribute to the founder of pediatric neurosurgery in Romania and one of the female pioneer neurosurgeons, who, by personal example of dedication and hard work, radically changed medical thinking and neurosurgery in Romania.

  14. Neurosurgery Education and Development program to treat hydrocephalus and to develop neurosurgery in Africa using mobile neuroendoscopic training.

    PubMed

    Piquer, José; Qureshi, Mubashir Mahmood; Young, Paul H; Dempsey, Robert J

    2015-06-01

    OBJECT A shortage of neurosurgeons and a lack of knowledge of neuroendoscopic management of hydrocephalus limits modern care in sub-Saharan Africa. Hence, a mobile teaching project for endoscopic third ventriculostomy (ETV) procedures and a subsequent program to develop neurosurgery as a permanent specialty in Kenya and Zanzibar were created and sponsored by the Neurosurgery Education and Development (NED) Foundation and the Foundation for International Education in Neurological Surgery. The objective of this work was to evaluate the results of surgical training and medical care in both projects from 2006 to 2013. METHODS Two portable neuroendoscopy systems were purchased and a total of 38 ETV workshops were organized in 21 hospitals in 7 different countries. Additionally, 49 medical expeditions were dispatched to the Coast General Hospital in Mombasa, Kenya, and to the Mnazi Moja Hospital in Zanzibar. RESULTS From the first project, a total of 376 infants with hydrocephalus received surgery. Six-month follow-up was achieved in 22%. In those who received follow-up, ETV efficacy was 51%. The best success rates were achieved with patients 1 year of age or older with aqueductal stenosis (73%). The main causes of hydrocephalus were infection (56%) and spina bifida (23%). The mobile education program interacted with 72 local surgeons and 122 nurses who were trained in ETV procedures. The second project involved 49 volunteer neurosurgeons who performed a total of 360 nonhydrocephalus neurosurgical operations since 2009. Furthermore, an agreement with the local government was signed to create the Mnazi Mmoja NED Institute in Zanzibar. CONCLUSIONS Mobile endoscopic treatment of hydrocephalus in East Africa results in reasonable success rates and has also led to major developments in medicine, particularly in the development of neurosurgery specialty care sites.

  15. Construction of spline functions in spreadsheets to smooth experimental data

    USDA-ARS?s Scientific Manuscript database

    A previous manuscript detailed how spreadsheet software can be programmed to smooth experimental data via cubic splines. This addendum corrects a few errors in the previous manuscript and provides additional necessary programming steps. ...

  16. Informed consent in neurosurgery--translating ethical theory into action.

    PubMed

    Schmitz, Dagmar; Reinacher, Peter C

    2006-09-01

    Although a main principle of medical ethics and law since the 1970s, standards of informed consent are regarded with great scepticism by many clinicans. By reviewing the reactions to and adoption of this principle of medical ethics in neurosurgery, the characteristic conflicts that emerge between theory and everyday clinical experience are emphasised and a modified conception of informed consent is proposed. The adoption and debate of informed consent in neurosurgery took place in two steps. Firstly, respect for patient autonomy was included into the ethical codes of the professional organisations. Secondly, the legal demands of the principle were questioned by clinicians. Informed consent is mainly interpreted in terms of freedom from interference and absolute autonomy. It lacks a constructive notion of physician-patient interaction in its effort to promote the best interest of the patient, which, however, potentially emerges from a reconsideration of the principle of beneficence. To avoid insufficient legal interpretations, informed consent should be understood in terms of autonomy and beneficence. A continuous interaction between the patient and the given physician is considered as an essential prerequisite for the realisation of the standards of informed consent.

  17. Interrupted time-series analysis: studying trends in neurosurgery.

    PubMed

    Wong, Ricky H; Smieliauskas, Fabrice; Pan, I-Wen; Lam, Sandi K

    2015-12-01

    OBJECT Neurosurgery studies traditionally have evaluated the effects of interventions on health care outcomes by studying overall changes in measured outcomes over time. Yet, this type of linear analysis is limited due to lack of consideration of the trend's effects both pre- and postintervention and the potential for confounding influences. The aim of this study was to illustrate interrupted time-series analysis (ITSA) as applied to an example in the neurosurgical literature and highlight ITSA's potential for future applications. METHODS The methods used in previous neurosurgical studies were analyzed and then compared with the methodology of ITSA. RESULTS The ITSA method was identified in the neurosurgical literature as an important technique for isolating the effect of an intervention (such as a policy change or a quality and safety initiative) on a health outcome independent of other factors driving trends in the outcome. The authors determined that ITSA allows for analysis of the intervention's immediate impact on outcome level and on subsequent trends and enables a more careful measure of the causal effects of interventions on health care outcomes. CONCLUSIONS ITSA represents a significant improvement over traditional observational study designs in quantifying the impact of an intervention. ITSA is a useful statistical procedure to understand, consider, and implement as the field of neurosurgery evolves in sophistication in big-data analytics, economics, and health services research.

  18. The Current Use of Social Media in Neurosurgery.

    PubMed

    Alotaibi, Naif M; Badhiwala, Jetan H; Nassiri, Farshad; Guha, Daipayan; Ibrahim, George M; Shamji, Mohammed F; Lozano, Andres M

    2016-04-01

    To measure the presence and popularity of neurosurgical departments, journals, and nonprofit organizations on 3 major social networks. A systematic 2-pronged search strategy was used in June 2015 to identify all accounts on Facebook, Twitter, and YouTube that were relevant to neurosurgery. Online search was conducted by 2 independent authors. All accounts were ranked according to their popularity data. Our search yielded 158 social media accounts (86 Facebook, 59 Twitter, and 13 YouTube) of neurosurgical private and academic practice departments. Of the 158 accounts we retrieved, 117 were for private practice centers (74%). Accounts of academic and private departments had a similar median number of "likes" and "followers" on Facebook and Twitter, respectively. Seven neurosurgical journals only had active Facebook and Twitter accounts (of 20 screened journals). When compared with studies of social media in other medical subspecialties, the use of these networks in neurosurgery followed a similar pattern in their presence and popularity. The current study shows different uses of social media platforms and numbers of users of the online neurosurgical community. Content optimization, advanced metrics of user engagement, and their subsequent effects on academic impact remain unanswered queries and require further prospective study. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Neurosurgery in Tanzania: a discussion of culture, socioeconomics, and humanitarians.

    PubMed

    Kinasha, Abednego; Kucia, Elisa J; Vargas, Jan; Kavolus, Joseph; Magarik, Jordan; Ellegala, Dilantha B; Nicholas, Joyce

    2012-07-01

    To elucidate the progress of neurosurgical practices in Tanzania, taking into account humanitarian, socioeconomic, and geographic influences. Articles, records, and historical texts were consulted to establish a timeline and history of neurosurgery in Tanzania. Reulen, a German neurosurgeon, was integral to the development of sustainable neurosurgical services in Tanzania. By training Tanzanians who returned to their country to practice, Reulen helped to establish a continuity of care and legacy on which future Tanzanian surgeons could build. Subsequently, as neurosurgical services were integrated into the Muhimbili Orthopedic Institute, surgeons found a hospital to call home and a place to focus their efforts. Neurosurgical services have now been offered to the Tanzanian people for >40 years, a direct consequence of international influences coupled with certain extraordinary Tanzanian physicians. Neurosurgery in Tanzania and Africa more generally has a long history; however, it was not until more recent efforts of certain local pioneers and educational advisors abroad that modernization occurred. The progress of the past 50 years is substantial and with continued efforts advances will continue to be made. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Virtual reality simulation in neurosurgery: technologies and evolution.

    PubMed

    Chan, Sonny; Conti, François; Salisbury, Kenneth; Blevins, Nikolas H

    2013-01-01

    Neurosurgeons are faced with the challenge of learning, planning, and performing increasingly complex surgical procedures in which there is little room for error. With improvements in computational power and advances in visual and haptic display technologies, virtual surgical environments can now offer potential benefits for surgical training, planning, and rehearsal in a safe, simulated setting. This article introduces the various classes of surgical simulators and their respective purposes through a brief survey of representative simulation systems in the context of neurosurgery. Many technical challenges currently limit the application of virtual surgical environments. Although we cannot yet expect a digital patient to be indistinguishable from reality, new developments in computational methods and related technology bring us closer every day. We recognize that the design and implementation of an immersive virtual reality surgical simulator require expert knowledge from many disciplines. This article highlights a selection of recent developments in research areas related to virtual reality simulation, including anatomic modeling, computer graphics and visualization, haptics, and physics simulation, and discusses their implication for the simulation of neurosurgery.

  1. [Robotics in neurosurgery: current status and future prospects].

    PubMed

    Benabid, A L; Hoffmann, D; Ashraf, A; Koudsie, A; Esteve, F; Le Bas, J F

    1998-02-01

    Neurosurgery is in essence a field of application development for robots, based on multimodal image guidance. Specific motorized tools have already been developed and routinely applied in stereotaxy to position a probe holder or in conventional neurosurgery to hold a microscope oriented towards a given target. The potentialities of these approaches have triggered industrial developments which are now commercially available. These systems use databases, primarily coming from multimodal numerical images from X-ray radiology to magnetic resonance imaging. These spatially encoded data are transferred through digital networks to workstations where images can be processed and surgical procedures are pre-planned, then transferred to the robotic systems to which they are connected. We have been using a stereotaxic robot since 1989 and a microscope robot since 1995 in various surgical routine procedures. The future of these applications rely mainly on the technical progress in informatics, about image recognition to adapt the pre-planning to the actual surgical situation, to correct brain shifts (for instance), about image fusion, integrated knowledge such as brain atlases, as well as virtual reality. The future developments, covering surgical procedure, research and teaching, are sure to be far beyond our wildest expectations.

  2. Experimental Economics for Teaching the Functioning of Electricity Markets

    ERIC Educational Resources Information Center

    Guevara-Cedeno, J. Y.; Palma-Behnke, R.; Uribe, R.

    2012-01-01

    In the field of electricity markets, the development of training tools for engineers has been extremely useful. A novel experimental economics approach based on a computational Web platform of an electricity market is proposed here for the practical teaching of electrical engineering students. The approach is designed to diminish the gap that…

  3. Experimental Economics for Teaching the Functioning of Electricity Markets

    ERIC Educational Resources Information Center

    Guevara-Cedeno, J. Y.; Palma-Behnke, R.; Uribe, R.

    2012-01-01

    In the field of electricity markets, the development of training tools for engineers has been extremely useful. A novel experimental economics approach based on a computational Web platform of an electricity market is proposed here for the practical teaching of electrical engineering students. The approach is designed to diminish the gap that…

  4. The Motivational Function of Private Speech: An Experimental Approach.

    ERIC Educational Resources Information Center

    de Dios, M. J.; Montero, I.

    Recently, some works have been published exploring the role of private speech as a tool for motivation, reaching beyond the classical research on its regulatory function for cognitive processes such as attention or executive function. In fact, the authors' own previous research has shown that a moderate account of spontaneous private speech of…

  5. Animal Structures and Functions, Science (Experimental): 5314.13.

    ERIC Educational Resources Information Center

    Silver, Barbara A.

    This unit of instruction was designed to introduce the student to the relationship between structure and function in the animal kingdom, with emphasis given to: (1) the evolution of physiological systems in the major animal phyla, (2) the complementarity of structure and function, and (3) the concept of homeostasis. The booklet lists the relevant…

  6. A critical analysis of the current state of neurosurgery training in Pakistan

    PubMed Central

    Shamim, M. Shahzad; Tahir, M. Zubair; Godil, Saniya Siraj; Kumar, Rajesh; Siddiqui, Arshad Ali

    2011-01-01

    Objective: To observe interdepartmental variation in the availability of resources and academic activities within the various neurosurgery programs of Pakistan. Methods: This was a proforma-based survey of neurosurgery trainees and young neurosurgeons of Pakistan, looking at the academic infrastructure and output of their programs. The proforma was filled by 36 respondents from 11 neurosurgery centers of the country. All these centers were accredited for neurosurgery training in Pakistan. Results: Out of the 36 respondents, 30 were completing a Fellowship training (FCPS) and six were enrolled for a Master in Surgery (MS) program. About 80% of the participants used the Youman's Textbook of Neurosurgery as a reference book. Only 40% of the candidates had access to more than one indexed neurosurgery journal. Structured academic sessions (e.g., journal clubs and neuropathology meetings) were lacking in a majority of the training institutes, 95% of the trainees had no microsurgical laboratory experience, and modern neurosurgical tools (frameless neuronavigation system, neuroendoscopy) were in use at a few centers only. Conclusion: Neurosurgery training in Pakistan is not uniform and wide variations exist between the programs at the centers evaluated. We recommend exchange programs between centers at national and international levels, to allow trainees to gain first-hand exposure to training components not available in their own center. PMID:22276237

  7. A critical analysis of the current state of neurosurgery training in Pakistan.

    PubMed

    Shamim, M Shahzad; Tahir, M Zubair; Godil, Saniya Siraj; Kumar, Rajesh; Siddiqui, Arshad Ali

    2011-01-01

    To observe interdepartmental variation in the availability of resources and academic activities within the various neurosurgery programs of Pakistan. This was a proforma-based survey of neurosurgery trainees and young neurosurgeons of Pakistan, looking at the academic infrastructure and output of their programs. The proforma was filled by 36 respondents from 11 neurosurgery centers of the country. All these centers were accredited for neurosurgery training in Pakistan. Out of the 36 respondents, 30 were completing a Fellowship training (FCPS) and six were enrolled for a Master in Surgery (MS) program. About 80% of the participants used the Youman's Textbook of Neurosurgery as a reference book. Only 40% of the candidates had access to more than one indexed neurosurgery journal. Structured academic sessions (e.g., journal clubs and neuropathology meetings) were lacking in a majority of the training institutes, 95% of the trainees had no microsurgical laboratory experience, and modern neurosurgical tools (frameless neuronavigation system, neuroendoscopy) were in use at a few centers only. Neurosurgery training in Pakistan is not uniform and wide variations exist between the programs at the centers evaluated. We recommend exchange programs between centers at national and international levels, to allow trainees to gain first-hand exposure to training components not available in their own center.

  8. Experimental studies on spinal cord function using evoked action potentials.

    PubMed

    Soeda, S; Satomi, K; Hirabayashi, K

    1990-01-01

    Experiments were carried out on cats to determine the use of conductive evoked spinal cord action potentials in diagnosing motor function of the spinal cord. Direct stimulation from the dura produced three negative wave potentials, N1, N2 and N3. The intraspinal pathway of N2 and N3 was the dorsal column. The pathways of N1, determined by dorsal and ventral epidural recording, were the dorsilateral funicle and the extrapyramidal tracts. A collision experiment between potential N1 and pyramidal tract action potential did not reflect the function of the tract as the amplitude of the action potential was too small. Nevertheless, it is considered that conductive evoked spinal cord action potentials could become a valuable method of assessing spinal cord function as they reflect the function of the extrapyramidal tracts, as well as of the dorsilateral funicle and the dorsal column.

  9. The g2 Structure Function: An Experimental Overview

    SciTech Connect

    Slifer, Karl

    2009-08-01

    We will discuss recent results for the spin structure functions, with an emphasis on g2 . High precision g2 data allows for tests of the Burkhardt-Cottingham sum rule, and is needed to consistently evaluate higher twist effects.

  10. Influence of experimental hypokinesia on gastric secretory function

    NASA Technical Reports Server (NTRS)

    Markova, O. O.; Vavryshchuk, V. I.; Rozvodovskyy, V. I.; Proshcheruk, V. A.

    1980-01-01

    The gastric secretory function of rats was studied in 4, 8, 16 and 30 day hypokinesia. Inhibition of both the gastric juice secretory and acid producing functions was found. The greatest inhibition was observed on day 8 of limited mobility. By days 16 and 30 of the experiment, a tendency of the gastric secretory activity to return to normal was observed, although it remained reduced.

  11. The development of neurosurgery at the University of Utah, 1955-2009.

    PubMed

    House, Paul A; Heilbrun, M Peter; Apfelbaum, Ronald I; Kraus, Kristin L; Couldwell, William T

    2010-09-01

    Located in the geographic Intermountain West, the Department of Neurosurgery at the University of Utah has undergone remarkable growth and transformation since the appointment of the first full-time clinical faculty member in 1955. The Department has provided broad neurosurgical services to an expanding community while fulfilling its academic mission of pushing the frontiers within neurosurgical subspecialties. The history of neurosurgery in the Salt Lake Valley and the achievements of the Department of Neurosurgery, including the seminal development of early cranial stereotactic devices, are reviewed in this article.

  12. [Intraoperative monitoring of oxygen tissue pressure: Applications in vascular neurosurgery].

    PubMed

    Arikan, Fuat; Vilalta, Jordi; Torne, Ramon; Chocron, Ivette; Rodriguez-Tesouro, Ana; Sahuquillo, Juan

    2014-01-01

    Ischemic lesions related to surgical procedures are a major cause of postoperative morbidity in patients with cerebral vascular disease. There are different systems of neuromonitoring to detect intraoperative ischemic events, including intraoperative monitoring of oxygen tissue pressure (PtiO2). The aim of this article was to describe, through the discussion of 4 cases, the usefulness of intraoperative PtiO2 monitoring during vascular neurosurgery. In presenting these cases, we demonstrate that monitoring PtiO2 is a reliable way to detect early ischemic events during surgical procedures. Continuous monitoring of PtiO2 in an area at risk allows the surgeon to resolve the cause of the ischemic event before it evolves to an established cerebral infarction. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  13. Balloons in endovascular neurosurgery: history and current applications.

    PubMed

    Alaraj, Ali; Wallace, Adam; Dashti, Reza; Patel, Prasad; Aletich, Victor

    2014-02-01

    The use of balloons in the field of neurosurgery is currently an essential part of our clinical practice. The field has evolved over the last 40 years since Serbinenko used balloons to test the feasibility of occluding cervical vessels for intracranial pathologies. Since that time, indications have expanded to include sacrificing cervical and intracranial vessels with detachable balloons, supporting the coil mass in wide-necked aneurysms (balloon remodeling technique), and performing intracranial and cervical angioplasty for atherosclerotic disease, as well as an adjunct to treat arteriovenous malformations. With the rapid expansion of endovascular technologies, it appears that the indications and uses for balloons will continue to expand. In this article, we review the history of balloons, the initial applications, the types of balloons available, and the current applications available for endovascular neurosurgeons.

  14. The incidentaloma of the pituitary gland: Is neurosurgery required

    SciTech Connect

    Reincke, M.; Allolio, B.; Saeger, W.; Menzel, J.; Winkelmann, W. )

    1990-05-23

    The authors describe a series of 18 patients with an intrasellar mass incidentally discovered by computed tomography or magnetic resonance imaging. The average size of the mass was 13 mm, with a range from 5 to 25 mm. Initial ophthalmologic examination revealed bitemporal hemianopia in 2 patients. Results of routine endocrine testing showed partial hypopituitarism in 5 patients and growth hormone hypersecretion without signs and symptoms of acromegaly in 1 patient. Four patients underwent neurosurgery. Histologically, one chondroid chordoma and three pituitary adenomas were found. In the remaining 14 patients treated conservatively, repeated computed tomography and magnetic resonance imaging revealed no significant change in tumor size at the time of follow-up. The results suggest that the incidentaloma of the pituitary gland is a benign condition that does not necessarily require neurosurgical intervention.

  15. Simulation and augmented reality in endovascular neurosurgery: lessons from aviation.

    PubMed

    Mitha, Alim P; Almekhlafi, Mohammed A; Janjua, Major Jameel J; Albuquerque, Felipe C; McDougall, Cameron G

    2013-01-01

    Endovascular neurosurgery is a discipline strongly dependent on imaging. Therefore, technology that improves how much useful information we can garner from a single image has the potential to dramatically assist decision making during endovascular procedures. Furthermore, education in an image-enhanced environment, especially with the incorporation of simulation, can improve the safety of the procedures and give interventionalists and trainees the opportunity to study or perform simulated procedures before the intervention, much like what is practiced in the field of aviation. Here, we examine the use of simulators in the training of fighter pilots and discuss how similar benefits can compensate for current deficiencies in endovascular training. We describe the types of simulation used for endovascular procedures, including virtual reality, and discuss the relevant data on its utility in training. Finally, the benefit of augmented reality during endovascular procedures is discussed, along with future computerized image enhancement techniques.

  16. Neurosurgery in Würzburg until World War II.

    PubMed

    Arnold, H; Collmann, H

    2012-01-01

    The institution of German neurosurgery as an autonomous surgical specialty, starting in Würzburg in 1934, is closely linked to the names of Fritz König and Wilhelm Tönnis. They were acting at a time when the global economic crisis and a consolidating Nazi dictatorship caused a cascade of alarming changes in political and social life. On the one hand it is fascinating to see how the restless work and energy of Tönnis managed to build up the first independent neurosurgical unit in Germany and to tighten efficient international connections all over the world within a few years. On the other hand-from a present-day perspective-it is difficult to understand how his strive towards a specialist's success, in contrast to that of Otfrid Foerster, was barely affected by the threatening political development, until the Second World War stopped his plans and ideas for many years.

  17. Force detecting gripper and flexible micro manipulator for neurosurgery.

    PubMed

    Yoneyama, T; Watanabe, T; Kagawa, H; Hamada, J; Hayashi, Y; Nakada, M

    2011-01-01

    In order to realize a less invasive robotic neurosurgery for the deeply seated tumor, a force detecting gripper with a flexible micro manipulator has been developed. Gripping force applied on the gripper is detected by strain gages fit on the gripper clip. Signal is conducted to the amplifier by the cables through the inner pipe of the manipulator. In order to approach to the deeply seated tumor through a narrow hole, a micro manipulator which can flex at the end part to face the gripper for the target and can rotate the closing direction of the gripper at the end of the manipulator has been developed. Some operation test showed that the developed manipulator can approach flexibly to the target, and the taking out force of a target on the soft material was detected clearly.

  18. New laser technologies in the clinic of neurosurgery

    NASA Astrophysics Data System (ADS)

    Stupak, V. V.; Fomichev, N. G.; Tsvetovsky, S. B.; Dmitriev, A. B.; Kobosev, V. V.; Bagaev, S. N.; Mayorov, A. P.; Struts, S. G.

    2005-08-01

    In report summarized more then 10 experience of authors in Novosibirsk Traumatology and orthopedics research institute Neurosurgery clinic on usage of laser technologies in treatment of central nervous system tumors. On the basis of ND-YAG laser application original technologies have been developed and used in surgical treatment of patients with various neurosurgical pathology and protected by 8 Patents of the Russian Federation. 427 patients were operated on with the use of YAG:Nd3+ laser. Out of them 152 patients had extracerebral tumors of various volume and localization, 135 patients - spinal cord tumors, 74 patients - a pathology of cerebrospinal transition (Amold-Chiari syndrome of 1-2 types), and 66 patients - intramedullary tumors of deep localization. Results showed good results of laser technologies usage for central nervous system tumors removal.

  19. Experimental Manipulation of the Microbial Functional Amyloid Called Curli

    PubMed Central

    Zhou, Yizhou; Smith, Daniel R.; Hufnagel, David A.; Chapman, Matthew R.

    2013-01-01

    Curli are proteinaceous fibrous structures produced on the surface of many gram-negative bacteria. As a major constituent of the extracellular matrix, curli mediate interactions between the bacteria and its environment, and as such, curli play a critical role in bio film formation. Curli fibers share biophysical properties with a growing number of remarkably stable and ordered protein aggregates called amyloid. Here we describe experimental methods to study the biogenesis and assembly of curli by exploiting their amyloid properties. We also present methods to analyze curli-mediated biofilm formation. These approaches are straightforward and can easily be adapted to study other bacterially produced amyloids. PMID:23299728

  20. Emergency neurosurgery in Darwin: still the generalist surgeons' responsibility.

    PubMed

    Luck, Tara; Treacy, Peter John; Mathieson, Matthew; Sandilands, Jessica; Weidlich, Stephanie; Read, David

    2015-09-01

    Royal Darwin Hospital (RDH) is the only major hospital for the 'Top End' of Northern Territory and Western Australia. As retrieval distances exceed 2600 km, resident generalist surgeons undertake all emergency neurosurgery. Retrospective clinical study from RDH records and review of prospectively collected datasets from RDH Intensive Care Unit and National Critical Care Trauma Response Centre for all emergency neurosurgery patients between 2008 and 2013. Data were obtained from 161 patients with 167 admissions (73% male, 39% indigenous) who underwent 195 procedures (33 per year), including burr hole, craniotomy, cerebral and posterior fossa craniectomy, elevation fracture and ventricular drain. Trauma accounted for 68%, with alcohol as a known factor in 57%. Subdural haematoma (SDH) accounted for 53%. Severity of head injury at presentation correlated with outcome (R(2) = 0.12, P < 0.001). Factors associated with death included injury at remote location (P = 0.022), time injury to operation >24 h (P = 0.023) and specific diagnoses of acute SDH (P = 0.006), acute-on-chronic SDH (P = 0.053) and infection (P = 0.052). Indigenous patients were younger (40 versus 55 years, P < 0.001) and more likely to have alcohol as a factor in trauma cases (71% versus 49%, P = 0.027). Time from injury to hospital was high for accidents at a remote location (12.9 versus 1.3 h, P < 0.001); however, Glasgow Outcome Scales (P = 0.13) were no different to accident at metropolitan Darwin. General surgeons at RDH perform a wide range of emergency neurosurgical procedures primarily for trauma. Factors contributing to poor outcomes included remote location of trauma and delay in reaching the hospital. Outcomes at 3 months appear acceptable. © 2015 Royal Australasian College of Surgeons.

  1. In vivo porcine training model for cranial neurosurgery.

    PubMed

    Regelsberger, Jan; Eicker, Sven; Siasios, Ioannis; Hänggi, Daniel; Kirsch, Matthias; Horn, Peter; Winkler, Peter; Signoretti, Stefano; Fountas, Kostas; Dufour, Henry; Barcia, Juan A; Sakowitz, Oliver; Westermaier, Thomas; Sabel, Michael; Heese, Oliver

    2015-01-01

    Supplemental education is desirable for neurosurgical training, and the use of human cadaver specimen and virtual reality models is routine. An in vivo porcine training model for cranial neurosurgery was introduced in 2005, and our recent experience with this unique model is outlined here. For the first time, porcine anatomy is illustrated with particular respect to neurosurgical procedures. The pros and cons of this model are described. The aim of the course was to set up a laboratory scenery imitating an almost realistic operating room in which anatomy of the brain and neurosurgical techniques in a mentored environment free from time constraints could be trained. Learning objectives of the course were to learn about the microsurgical techniques in cranial neurosurgery and the management of complications. Participants were asked to evaluate the quality and utility of the programme via standardized questionnaires by a grading scale from A (best) to E (worst). In total, 154 residents have been trained on the porcine model to date. None of the participants regarded his own residency programme as structured. The bleeding and complication management (97%), the realistic laboratory set-up (89%) and the working environment (94%) were favoured by the vast majority of trainees and confirmed our previous findings. After finishing the course, the participants graded that their skills in bone drilling, dissecting the brain and preserving cerebral vessels under microscopic magnification had improved to level A and B. In vivo hands-on courses, fully equipped with microsurgical instruments, offer an outstanding training opportunity in which bleeding management on a pulsating, vital brain represents a unique training approach. Our results have shown that education programmes still lack practical training facilities in which in vivo models may act as a complementary approach in surgical training.

  2. Review of 3-Dimensional Printing on Cranial Neurosurgery Simulation Training.

    PubMed

    Vakharia, Vejay N; Vakharia, Nilesh N; Hill, Ciaran S

    2016-04-01

    Shorter working times, reduced operative exposure to complex procedures, and increased subspecialization have resulted in training constraints within most surgical fields. Simulation has been suggested as a possible means of acquiring new surgical skills without exposing patients to the surgeon's operative "learning curve." Here we review the potential impact of 3-dimensional printing on simulation and training within cranial neurosurgery and its implications for the future. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search of PubMed, OVID MEDLINE, Embase, and the Cochrane Database of Systematic Reviews was performed. In total, 31 studies relating to the use of 3-dimensional (3D) printing within neurosurgery, of which 16 were specifically related to simulation and training, were identified. The main impact of 3D printing on neurosurgical simulation training was within vascular surgery, where patient-specific replication of vascular anatomy and pathologies can aid surgeons in operative planning and clip placement for reconstruction of vascular anatomy. Models containing replicas of brain tumors have also been reconstructed and used for training purposes, with some providing realistic representations of skin, subcutaneous tissue, bone, dura, normal brain, and tumor tissue. 3D printing provides a unique means of directly replicating patient-specific pathologies. It can identify anatomic variation and provide a medium in which training models can be generated rapidly, allowing the trainee and experienced neurosurgeon to practice parts of operations preoperatively. Future studies are required to validate this technology in comparison with current simulators and show improved patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Patients' views on priority setting in neurosurgery: A qualitative study.

    PubMed

    Gunaratnam, Caroline; Bernstein, Mark

    2016-01-01

    Accountability for Reasonableness is an ethical framework which has been implemented in various health care systems to improve and evaluate the fairness of priority setting. This framework is grounded on four mandatory conditions: relevance, publicity, appeals, and enforcement. There have been few studies which have evaluated the patient stakeholders' acceptance of this framework; certainly no studies have been done on patients' views on the prioritization system for allocating patients for operating time in a system with pressure on the resource of inpatient beds. The aim of this study is to examine neurosurgical patients' views on the prioritization of patients for operating theater (OT) time on a daily basis at a tertiary and quaternary referral neurosurgery center. Semi-structured face-to-face interviews were conducted with thirty-seven patients, recruited from the neurosurgery clinic at Toronto Western Hospital. Family members and friends who accompanied the patient to their clinic visit were encouraged to contribute to the discussion. Interviews were audio recorded, transcribed verbatim, and subjected to thematic analysis using open and axial coding. Overall, patients are supportive of the concept of a priority-setting system based on fairness, but felt that a few changes would help to improve the fairness of the current system. These changes include lowering the level of priority given to volume-funded cases and providing scheduled surgeries that were previously canceled a higher level of prioritization. Good communication, early notification, and rescheduling canceled surgeries as soon as possible were important factors that directly reflected the patients' confidence level in their doctor, the hospital, and the health care system. This study is the first clinical qualitative study of patients' perspective on a prioritization system used for allocating neurosurgical patients for OT time on a daily basis in a socialized not-for-profit health care system with

  4. Functional capacity of the thyroid autograft: an experimental study.

    PubMed

    Papaziogas, B; Antoniadis, A; Lazaridis, Ch; Makris, J; Kotakidou, R; Paraskevas, G; Papaziogas, T

    2002-04-01

    The aim of this study was to investigate the functional capacity of thyroid autografts after total thyroidectomy in a rabbit model. Thirty-eight rabbits underwent total thyroidetomy. One of the two thyroid lobes was cut into 1-mm pieces and was introduced intramuscularly into the right quadriceps muscle (group A, n = 10), the right rectus abdominalis muscle (group B, n = 10), and the right sacrodorsalis muscle (group C, n = 10). Another group of 8 rabbits underwent total thyroidectomy without autologous implantation and served as the control group (group D). The animals were observed for 8 weeks with weekly measurements of thyroid hormones. At the end of the 8th week, a scintigram was performed. The autografts were removed 2 days later. The thyroid hormone levels showed a gradual decrease until the 2nd-5th week after implantation, followed by a gradual increase and establishment of euthyroid levels between the 5th and 8th weeks. Respectively, an increase of thyreotropin hormone was noted with maximal values in the 4th week, followed by a gradual decrease until the end of the 8th week. The scintigram at the end of the 8th week revealed the presence of functional thyroid tissue in all cases. Functional thyroid follicles were found in all animals who survived. In 35.7% of the autografts, we noted the development of fibrous tissue and gigantocytic granulomas in the periphery, which could be interpretated as a "foreign body" reaction. Thyroid autografts can completely substitute thyroid function after total thyroidectomy.

  5. Academic Productivity of US Neurosurgery Residents as Measured by H-Index: Program Ranking with Correlation to Faculty Productivity.

    PubMed

    Sarkiss, Christopher A; Riley, Kyle J; Hernandez, Christopher M; Oermann, Eric K; Ladner, Travis R; Bederson, Joshua B; Shrivastava, Raj K

    2017-03-29

    Engagement in research and academic productivity are crucial components in the training of a neurosurgeon. This process typically begins in residency training. In this study, we analyzed individual resident productivity as it correlated to publications across all Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery training programs in an attempt to identify how programs have developed and fostered a research culture and environment. We obtained a list of current neurosurgery residents in ACGME-accredited programs from the American Association of Neurological Surgeons database. An expanded PubMed and Scopus search was conducted for each resident through the present time. We tabulated all articles attributed to each resident. We then categorized the publications based on each neurosurgical subspecialty while in residency. A spreadsheet-based statistical analysis was performed. This formulated the average number of resident articles, h-indices, and most common subspecialty categories by training program. We analyzed 1352 current neurosurgery residents in 105 programs. There were a total of 10 645 publications, of which 3985 were resident first-author publications during the period of study. The most common subspecialties among all resident publications were vascular (24.9%), spine (16.9%), oncology (16.1%), pediatric (5.6%), functional (4.9%), and trauma (3.8%). The average resident published 2.9 first-author papers with average of 38.0 first-author publications by total residents at each program (range 0-241). The average h-index per resident is 2.47 ± 3.25. When comparing previously published faculty h-index program rankings against our resident h-index rankings, there is a strong correlation between the 2 datasets with a clear delineation between Top-20 productivity and that of other programs (average h-index 4.2 vs 1.7, respectively, P < .001). Increasing program size leads to a clear increase in academic productivity on both the

  6. Histamine H3 activation depresses cardiac function in experimental sepsis.

    PubMed

    Li, X; Eschun, G; Bose, D; Jacobs, H; Yang, J J; Light, R B; Mink, S N

    1998-11-01

    In the heart, histamine (H3) receptors may function as inhibitory presynaptic receptors that decrease adrenergic norepinephrine release in conditions of enhanced sympathetic neural activity. We hypothesized that H3-receptor blockade might improve cardiovascular function in sepsis. In a canine model of Escherichia coli sepsis, we found that H3-receptor blockade increased cardiac output (3.6 to 5.3 l/min, P < 0.05), systemic blood pressure (mean 76 to 96 mmHg, P < 0.05), and left ventricular contractility compared with pretreatment values. Plasma histamine concentrations increased modestly in the H3-blocker-sepsis group compared with values obtained in a nonsepsis-time-control group. In an in vitro preparation, histamine H3 activation could be identified under conditions of septic plasma. We conclude that activation of H3 receptors may contribute to cardiovascular collapse in sepsis.

  7. High functional diversity stimulates diversification in experimental microbial communities

    PubMed Central

    Jousset, Alexandre; Eisenhauer, Nico; Merker, Monika; Mouquet, Nicolas; Scheu, Stefan

    2016-01-01

    There is a growing awareness that biodiversity not only drives ecosystem services but also affects evolutionary dynamics. However, different theories predict contrasting outcomes on when do evolutionary processes occur within a context of competition. We tested whether functional diversity can explain diversification patterns. We tracked the survival and diversification of a focal bacterial species (Pseudomonas fluorescens) growing in bacterial communities of variable diversity and composition. We found that high functional diversity reduced the fitness of the focal species and, at the same time, fostered its diversification. This pattern was linked to resource competition: High diversity increased competition on a portion of the resources while leaving most underexploited. The evolved phenotypes of the focal species showed a better use of underexploited resources, albeit at a cost of lower overall growth rates. As a result, diversification alleviated the impact of competition on the fitness of the focal species. We conclude that biodiversity can stimulate evolutionary diversification, provided that sufficient alternative niches are available. PMID:27386573

  8. High functional diversity stimulates diversification in experimental microbial communities.

    PubMed

    Jousset, Alexandre; Eisenhauer, Nico; Merker, Monika; Mouquet, Nicolas; Scheu, Stefan

    2016-06-01

    There is a growing awareness that biodiversity not only drives ecosystem services but also affects evolutionary dynamics. However, different theories predict contrasting outcomes on when do evolutionary processes occur within a context of competition. We tested whether functional diversity can explain diversification patterns. We tracked the survival and diversification of a focal bacterial species (Pseudomonas fluorescens) growing in bacterial communities of variable diversity and composition. We found that high functional diversity reduced the fitness of the focal species and, at the same time, fostered its diversification. This pattern was linked to resource competition: High diversity increased competition on a portion of the resources while leaving most underexploited. The evolved phenotypes of the focal species showed a better use of underexploited resources, albeit at a cost of lower overall growth rates. As a result, diversification alleviated the impact of competition on the fitness of the focal species. We conclude that biodiversity can stimulate evolutionary diversification, provided that sufficient alternative niches are available.

  9. Cognitive eloquence in neurosurgery: Insight from graph theoretical analysis of complex brain networks.

    PubMed

    Lang, Stefan

    2017-01-01

    The structure and function of the brain can be described by complex network models, and the topological properties of these models can be quantified by graph theoretical analysis. This has given insight into brain regions, known as hubs, which are critical for integrative functioning and information transfer, both fundamental aspects of cognition. In this manuscript a hypothesis is put forward for the concept of cognitive eloquence in neurosurgery; that is regions (cortical, subcortical and white matter) of the brain which may not necessarily have readily identifiable neurological function, but if injured may result in disproportionate cognitive morbidity. To this end, the effects of neurosurgical resection on cognition is reviewed and an overview of the role of complex network analysis in the understanding of brain structure and function is provided. The literature describing network, behavioral, and cognitive effects resulting from lesions to, and disconnections of, centralized hub regions will be emphasized as evidence for the espousal of the concept of cognitive eloquence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Functional recovery in aging mice after experimental stroke.

    PubMed

    Manwani, Bharti; Liu, Fudong; Xu, Yan; Persky, Rebecca; Li, Jun; McCullough, Louise D

    2011-11-01

    Aging is a non-modifiable risk factor for stroke. Since not all strokes can be prevented, a major emerging area of research is the development of effective strategies to enhance functional recovery after stroke. However, in the vast majority of pre-clinical stroke studies, the behavioral tests used to assess functional recovery have only been validated for use in young animals, or are designed for rats. Mice are increasingly utilized in stroke models but well validated behavioral tests designed for rats are not necessarily reproducible in mice. We examined a battery of behavioral tests to evaluate functional recovery in an aging murine model of stroke. We found that the vertical pole, hanging wire and open field can accurately assess acute behavioral impairments after stroke in both young and aging male mice, but animals recover rapidly on these tasks. The corner test can accurately and repeatedly differentiate stroke from sham animals up to 30 days post stroke and can be performed reliably in aging mice. Aging male mice had significantly worse behavioral impairment compared to young male mice in the first two weeks after stroke but eventually recovered to the same degree as young mice. In contrast, chronic infarct size, as measured by ipsilateral cerebral atrophy, was significantly lower in aging male mice compared to young male mice. Reactive gliosis, formation of glial scar, and an enhanced innate immune response was seen in the aging brain and may contribute to the delayed behavioral recovery seen in the aging animals. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Hedonic ratings and perceived healthiness in experimental functional food choices.

    PubMed

    Urala, Nina; Lähteenmäki, Liisa

    2006-11-01

    The associations of liking and perceived healthiness ratings between repeated food choices were studied in two experiments. Participants' snack bar (n=41, Experiment I) and beverage (n=60, Experiment II) choices among six product alternatives were monitored for 4 and 3 weeks, respectively. In Experiment I, participants were allowed to familiarise themselves with snack bar alternatives ("familiar assortment") prior to making choices. In Experiment II, the participants started making their beverage choices without familiarising themselves ("unfamiliar assortment"). In both experiments, the participants were divided into three groups according to their choice behaviour for each alternative: non-interested (0 choices), experimenters (1 choice) and potential frequent users (2 or more choices). In Experiment I, the overall difference between non-interested and potential frequent users of a product was 1.3 points in expected liking and 2.6 points in actual liking on a 7-point scale (ANOVA, p<0.001). In Experiment II, the overall differences in blind hedonic ratings between non-interested participants and potential frequent users of a product were within a range of 0.9 points (p<0.001). The difference was wider for expected liking ratings, 1.3 points (p<0.001). Neither the perceived healthiness of the samples nor the background attitudes could be consistently associated with the choices (Pearson's correlation coefficient).

  12. Utilizing virtual and augmented reality for educational and clinical enhancements in neurosurgery.

    PubMed

    Pelargos, Panayiotis E; Nagasawa, Daniel T; Lagman, Carlito; Tenn, Stephen; Demos, Joanna V; Lee, Seung J; Bui, Timothy T; Barnette, Natalie E; Bhatt, Nikhilesh S; Ung, Nolan; Bari, Ausaf; Martin, Neil A; Yang, Isaac

    2017-01-01

    Neurosurgery has undergone a technological revolution over the past several decades, from trephination to image-guided navigation. Advancements in virtual reality (VR) and augmented reality (AR) represent some of the newest modalities being integrated into neurosurgical practice and resident education. In this review, we present a historical perspective of the development of VR and AR technologies, analyze its current uses, and discuss its emerging applications in the field of neurosurgery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Experimental studies on islets isolation, purification and function in rats.

    PubMed

    Pang, Xinlu; Xue, Wujun; Feng, Xinshun; Tian, Xiaohui; Teng, Yan; Ding, Xiaoming; Pan, Xiaoming; Guo, Qi; He, Xiaoli

    2015-01-01

    To develop a simple and effective method of islet isolation and purification in rats. Collagenase P was injected into pancreatic duct followed by incubation in water bath to digest the pancreas and isolate islet, then discontinuous gravity gradient purification was used to purify the islet. The purified islets were identified by dithizone staining. The viability of islets was assessed by fluorescence staining of acridine orange (AO) and propidium iodide (PI). The function of purified islets was determined by glucose-stimulated insulin release test and transplantation of rat with streptozocin-induced diabetes. 738±193 islets were recovered after purification. The average purity was 77±13%, the viability of islets was more than 95%. When inspected by glucose stimulation, the secreted insulin concentration was 24.31±5.47 mIU/L when stimulated by low concentration glucose and 37.62±4.29 mIU/L by high concentration glucose. There was significant difference between the two phases (P<0.05). The blood sugar concentration recovered to normal level after two days in the animals with islet transplantation. In conclusion, islets can be procured with good function and shape by using the method of injecting collagenase into pancreatic duct followed by incubation in water bath and purification using discontinuous gravity gradient.

  14. Experimental studies on islets isolation, purification and function in rats

    PubMed Central

    Pang, Xinlu; Xue, Wujun; Feng, Xinshun; Tian, Xiaohui; Teng, Yan; Ding, Xiaoming; Pan, Xiaoming; Guo, Qi; He, Xiaoli

    2015-01-01

    To develop a simple and effective method of islet isolation and purification in rats. Collagenase P was injected into pancreatic duct followed by incubation in water bath to digest the pancreas and isolate islet, then discontinuous gravity gradient purification was used to purify the islet. The purified islets were identified by dithizone staining. The viability of islets was assessed by fluorescence staining of acridine orange (AO) and propidium iodide (PI). The function of purified islets was determined by glucose-stimulated insulin release test and transplantation of rat with streptozocin-induced diabetes. 738±193 islets were recovered after purification. The average purity was 77±13%, the viability of islets was more than 95%. When inspected by glucose stimulation, the secreted insulin concentration was 24.31±5.47 mIU/L when stimulated by low concentration glucose and 37.62±4.29 mIU/L by high concentration glucose. There was significant difference between the two phases (P<0.05). The blood sugar concentration recovered to normal level after two days in the animals with islet transplantation. In conclusion, islets can be procured with good function and shape by using the method of injecting collagenase into pancreatic duct followed by incubation in water bath and purification using discontinuous gravity gradient. PMID:26885021

  15. The history of neurosurgery in Anatolia and Turkey: the Turkish Neurosurgical Society.

    PubMed

    Solaroglu, Ihsan; Acar, Feridun; Bavbek, Murad; Ture, Ugur; Beskonakli, Ethem

    2013-01-01

    Although the history of neurosurgery in Anatolia goes back ten thousand years, modern surgery began in Turkey in 1890. Neurosurgery in Turkey began in the first half of the 20th century. However, general surgeons began applying neurosurgical techniques back in the late 19th century. Most of these applications included procedures for craniocerebral traumas and infections. Dr. Cemil Topuzlu (1868-1958) is the founder of modern surgery in Turkey. Dr. Abdulkadir Cahit Tuner became the first neurosurgeon with a degree in Turkey in 1923. The first neurosurgery department was established in Istanbul in 1923, and the first training program began in the late 1940s. Currently there are almost 1200 neurosurgeons in Turkey and 75 training clinics at university hospitals and Training and Research Hospitals of the Ministry of Health provide neurosurgery training. The current state of neurosurgery in Turkey is parallel to that of the advanced Western countries. Apart from the application of neurosurgical procedures, there have been many scientific studies from Turkish neurosurgeons contributing to the total body of literature in neurosurgery.

  16. [Leydig cell function in experimental cryptorchism and varicocele in rats].

    PubMed

    Hernández-Yánez, L; Marín-López, G; Vílchez-Martínez, J; Bishop, W

    1999-06-01

    Leydig cells were isolated from testes of normal, cryptorchid and induced- varicocele rats. These cells were counted and coincubated with and without human Chorionic Gonadotropin (hCG) during 3 hours; thereafter, steroids were measured in the incubation media. Cryptorchid animals showed the lowest number of Leydig cells, the highest Progesterone response to hCG, a slight increment of testosterone and a decrease of estradiol. On the contrary, both left and right testes from varicocele induced rats showed a higher cell number (per g of tissue), lower progesterone response, slightly higher response testosterone and lower testosterone response. These results demonstrate that these conditions of testicular hyperthermia do not affect the number and function of Leydig cells to the same degree. This may be due to differences in the testicular temperature reached with each procedure.

  17. Comparison of theoretical and experimental dielectric functions: Electron energy-loss spectroscopy and density-functional calculations on skutterudites

    NASA Astrophysics Data System (ADS)

    Prytz, Ø.; Løvvik, O. M.; Taftø, J.

    2006-12-01

    We explore the possibility of combining density functional theory (DFT) and electron energy loss spectroscopy (EELS) to determine the dielectric function of materials. As model systems we use the skutterudites CoP3 , CoAs3 , and CoSb3 which are prototypes for thermoelectric materials. We achieve qualitative agreement between the theoretically and experimentally obtained low energy-loss spectra and dielectric function. Some of the remaining discrepancies may be caused by the challenge of refining the experimental spectra before Kramers-Kronig analysis. However, contrary to what is the case for some crystals with less complicated electronic structure, the DFT calculated plasmon energies deviate significantly from the experimental values. The great accuracy with which the plasmon energy can be determined by EELS, suggests that this technique may provide valuable inputs in further efforts to improve DFT calculations. The use of EELS as the experimental technique may become particularly powerful in studies of small volumes of materials.

  18. Experimental characterization of high speed centrifugal compressor aerodynamic forcing functions

    NASA Astrophysics Data System (ADS)

    Gallier, Kirk

    The most common and costly unexpected post-development gas turbine engine reliability issue is blade failure due to High Cycle Fatigue (HCF). HCF in centrifugal compressors is a coupled nonlinear fluid-structure problem for which understanding of the phenomenological root causes is incomplete. The complex physics of this problem provides significant challenges for Computational Fluid Dynamics (CFD) techniques. Furthermore, the available literature fails to address the flow field associated with the diffuser potential field, a primary cause of forced impeller vibration. Because of the serious nature of HCF, the inadequacy of current design approaches to predict HCF, and the fundamental lack of benchmark experiments to advance the design practices, there exists a need to build a database of information specific to the nature of the diffuser generated forcing function as a foundation for understanding flow induced blade vibratory failure. The specific aim of this research is to address the fundamental nature of the unsteady aerodynamic interaction phenomena inherent in high-speed centrifugal compressors wherein the impeller exit flow field is dynamically modulated by the vaned diffuser potential field or shock structure. The understanding of this unsteady aerodynamic interaction is fundamental to characterizing the impeller forcing function. Unsteady static pressure measurement at several radial and circumferential locations in the vaneless space offer a depiction of pressure field radial decay, circumferential variation and temporal fluctuation. These pressure measurements are coupled with high density, full field measurement of the velocity field within the diffuser vaneless space at multiple spanwise positions. The velocity field and unsteady pressure field are shown to be intimately linked. A strong momentum gradient exiting the impeller is shown to extend well across the vaneless space and interact with the diffuser vane leading edge. The deterministic unsteady

  19. Multispecies probiotic protects gut barrier function in experimental models.

    PubMed

    Nébot-Vivinus, Mylene; Harkat, Cherryl; Bzioueche, Hanene; Cartier, Christel; Plichon-Dainese, Raffaella; Moussa, Lara; Eutamene, Helene; Pishvaie, Dorsa; Holowacz, Sophie; Seyrig, Christian; Piche, Thierry; Theodorou, Vassilia

    2014-06-14

    To investigate the effect of the probiotic combination Lactibiane Tolerance(®) (LT) on epithelial barrier function in vitro and in vivo. The effect of the multispecies probiotic LT was assessed on several models of epithelial barrier function both in vitro (in basal and inflammatory conditions) and in vivo [visceral hypersensitivity induced by chronic stress or by colonic perfusion of a fecal supernatant (FSN) from patients with irritable bowel syndrome (IBS)]. In vitro, we measured the permeability of confluent T84 cell monolayers incubated with or without LT by evaluating the paracellular flux of macromolecules, in basal conditions and after stimulation with lipopolysaccharide (LPS) or with conditioned medium of colonic biopsies from IBS patients (IBS-CM). In vivo, male C57/Bl6 mice received orally NaCl or LT for 15 d and were submitted to water avoidance stress (WAS) before evaluating visceral sensitivity by measuring the myoelectrical activity of the abdominal muscle and the paracellular permeability with (51)Cr-EDTA. Permeability and sensitivity were also measured after colonic instillation of FSN. Tight-junctions were assessed by immunoblotting and TLR-4 expression was evaluated by immunohistochemistry Incubation of T84 cell monolayers with LT in basal conditions had no significant effect on permeability (P > 0.05 vs culture medium). By contrast, addition of LT bacterial bodies (LT) completely prevented the LPS-induced increase in paracellular permeability (P < 0.01 vs LPS 10 ng/mL (LPS 10); P < 0.01 vs LPS 100 ng/mL (LPS 100), P > 0.05 vs culture medium). The effect was dose dependent as addition of 10(9) LT bacterial bodies induced a stronger decrease in absorbance than 10(6) LT (10(9) LT + LPS 10: -20.1% ± 13.4, P < 0.01 vs LPS 10; 10(6) LT + LPS 10: -11.6% ± 6.2, P < 0.01 vs LPS 10; 10(9) LT + LPS 100: -14.4% ± 5.5, P < 0.01 vs LPS 100; 10(6) LT + LPS 100: -11.6% ± 7.3, P < 0.05 vs LPS 100). Moreover, the increase in paracellular permeability induced

  20. Uterine glands: development, function and experimental model systems.

    PubMed

    Cooke, Paul S; Spencer, Thomas E; Bartol, Frank F; Hayashi, Kanako

    2013-09-01

    Development of uterine glands (adenogenesis) in mammals typically begins during the early post-natal period and involves budding of nascent glands from the luminal epithelium and extensive cell proliferation in these structures as they grow into the surrounding stroma, elongate and mature. Uterine glands are essential for pregnancy, as demonstrated by the infertility that results from inhibiting the development of these glands through gene mutation or epigenetic strategies. Several genes, including forkhead box A2, beta-catenin and members of the Wnt and Hox gene families, are implicated in uterine gland development. Progestins inhibit uterine epithelial proliferation, and this has been employed as a strategy to develop a model in which progestin treatment of ewes for 8 weeks from birth produces infertile adults lacking uterine glands. More recently, mouse models have been developed in which neonatal progestin treatment was used to permanently inhibit adenogenesis and adult fertility. These studies revealed a narrow and well-defined window in which progestin treatments induced permanent infertility by impairing neonatal gland development and establishing endometrial changes that result in implantation defects. These model systems are being utilized to better understand the molecular mechanisms underlying uterine adenogenesis and endometrial function. The ability of neonatal progestin treatment in sheep and mice to produce infertility suggests that an approach of this kind may provide a contraceptive strategy with application in other species. Recent studies have defined the temporal patterns of adenogenesis in uteri of neonatal and juvenile dogs and work is underway to determine whether neonatal progestin or other steroid hormone treatments might be a viable contraceptive approach in this species.

  1. Preoperative anemia increases postoperative morbidity in elective cranial neurosurgery

    PubMed Central

    Bydon, Mohamad; Abt, Nicholas B.; Macki, Mohamed; Brem, Henry; Huang, Judy; Bydon, Ali; Tamargo, Rafael J.

    2014-01-01

    Background: Preoperative anemia may affect postoperative mortality and morbidity following elective cranial operations. Methods: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to identify elective cranial neurosurgical cases (2006-2012). Morbidity was defined as wound infection, systemic infection, cardiac, respiratory, renal, neurologic, and thromboembolic events, and unplanned returns to the operating room. For 30-day postoperative mortality and morbidity, adjusted odds ratios (ORs) were estimated with multivariable logistic regression. Results: Of 8015 patients who underwent elective cranial neurosurgery, 1710 patients (21.4%) were anemic. Anemic patients had an increased 30-day mortality of 4.1% versus 1.3% in non-anemic patients (P < 0.001) and an increased 30-day morbidity rate of 25.9% versus 14.14% in non-anemic patients (P < 0.001). The 30-day morbidity rates for all patients undergoing cranial procedures were stratified by diagnosis: 26.5% aneurysm, 24.7% sellar tumor, 19.7% extra-axial tumor, 14.8% intra-axial tumor, 14.4% arteriovenous malformation, and 5.6% pain. Following multivariable regression, the 30-day mortality in anemic patients was threefold higher than in non-anemic patients (4.1% vs 1.3%; OR = 2.77; 95% CI: 1.65-4.66). The odds of postoperative morbidity in anemic patients were significantly higher than in non-anemic patients (OR = 1.29; 95% CI: 1.03-1.61). There was a significant difference in postoperative morbidity event odds with a hematocrit level above (OR = 1.07; 95% CI: 0.78-1.48) and below (OR = 2.30; 95% CI: 1.55-3.42) 33% [hemoglobin (Hgb) 11 g/dl]. Conclusions: Preoperative anemia in elective cranial neurosurgery was independently associated with an increased risk of 30-day postoperative mortality and morbidity when compared to non-anemic patients. A hematocrit level below 33% (Hgb 11 g/dl) was associated with a significant increase in postoperative morbidity. PMID

  2. Patterns in neurosurgical adverse events: open cerebrovascular neurosurgery.

    PubMed

    Wong, Judith M; Ziewacz, John E; Ho, Allen L; Panchmatia, Jaykar R; Kim, Albert H; Bader, Angela M; Thompson, B Gregory; Du, Rose; Gawande, Atul A

    2012-11-01

    As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice. The authors performed a PubMed search using search terms "cerebral aneurysm", "cerebral arteriovenous malformation", "intracerebral hemorrhage", "intracranial hemorrhage", "subarachnoid hemorrhage", and "complications" or "adverse events." Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events. The review revealed hemorrhage-related hyperglycemia (incidence rates ranging from 27% to 71%) and cerebral salt-wasting syndromes (34%-57%) to be the most common perioperative adverse events related to subarachnoid hemorrhage (SAH). Next in terms of frequency was new cerebral infarction associated with SAH, with a rate estimated at 40%. Many techniques are advocated for use during surgery to minimize risk of this development, including intraoperative neurophysiological monitoring, but are not universally used due to surgeon preference and variable availability of appropriate staffing and equipment. The comparative effectiveness of using or omitting monitoring technologies has not been evaluated. The incidence of perioperative seizure related to vascular neurosurgery is unknown, but reported seizure rates from observational studies range from 4% to 42%. There are no standard guidelines for the use of seizure prophylaxis in these patients, and there remains a need for prospective studies to support such

  3. Lymphatic vessel density and function in experimental bladder cancer

    PubMed Central

    Saban, Marcia R; Towner, Rheal; Smith, Nataliya; Abbott, Andrew; Neeman, Michal; Davis, Carole A; Simpson, Cindy; Maier, Julie; Mémet, Sylvie; Wu, Xue-Ru; Saban, Ricardo

    2007-01-01

    Background The lymphatics form a second circulatory system that drains the extracellular fluid and proteins from the tumor microenvironment, and provides an exclusive environment in which immune cells interact and respond to foreign antigen. Both cancer and inflammation are known to induce lymphangiogenesis. However, little is known about bladder lymphatic vessels and their involvement in cancer formation and progression. Methods A double transgenic mouse model was generated by crossing a bladder cancer-induced transgenic, in which SV40 large T antigen was under the control of uroplakin II promoter, with another transgenic mouse harboring a lacZ reporter gene under the control of an NF-κB-responsive promoter (κB-lacZ) exhibiting constitutive activity of β-galactosidase in lymphatic endothelial cells. In this new mouse model (SV40-lacZ), we examined the lymphatic vessel density (LVD) and function (LVF) during bladder cancer progression. LVD was performed in bladder whole mounts and cross-sections by fluorescent immunohistochemistry (IHC) using LYVE-1 antibody. LVF was assessed by real-time in vivo imaging techniques using a contrast agent (biotin-BSA-Gd-DTPA-Cy5.5; Gd-Cy5.5) suitable for both magnetic resonance imaging (MRI) and near infrared fluorescence (NIRF). In addition, IHC of Cy5.5 was used for time-course analysis of co-localization of Gd-Cy5.5 with LYVE-1-positive lymphatics and CD31-positive blood vessels. Results SV40-lacZ mice develop bladder cancer and permitted visualization of lymphatics. A significant increase in LVD was found concomitantly with bladder cancer progression. Double labeling of the bladder cross-sections with LYVE-1 and Ki-67 antibodies indicated cancer-induced lymphangiogenesis. MRI detected mouse bladder cancer, as early as 4 months, and permitted to follow tumor sizes during cancer progression. Using Gd-Cy5.5 as a contrast agent for MRI-guided lymphangiography, we determined a possible reduction of lymphatic flow within the

  4. Thermal model to investigate the temperature in bone grinding for skull base neurosurgery.

    PubMed

    Zhang, Lihui; Tai, Bruce L; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J

    2013-10-01

    This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50°C as the threshold, the thermal injury can propagate about 3mm in the traverse direction, and 3mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study.

  5. Historical perspective on the Department of Neurosurgery at the Henry Ford Hospital.

    PubMed

    Kole, M K; O'Leary, S T; Malik, G M; Rosenblum, M L

    2001-02-01

    The Henry Ford Hospital (HFH) was founded in 1915 as a philanthropic gift from Henry Ford, the automobile magnate and inventor of the Model T. The hospital and its organizational structure represented a nonsectarian facility that would provide care for all members of society. The system was patterned after the newest and most modern medical centers at the time in Europe, Canada, and the United States, including the German Krankenhauser, the Johns Hopkins Hospital, the Mayo Clinic, and the Peter Bent Brigham Hospital in Boston. The HFH grew into the Henry Ford Health System in the 1970s to 1990s, with the acquisition of other hospitals, the development of a multiple-region-based clinic system through southeastern Michigan, and the development of comprehensive, vertically integrated health care systems. The Division of Neurosurgery at HFH was established by Albert Crawford in 1926. The tradition of training residents in neurosurgery began in 1946, and the residency training program was accredited by the American Board of Neurosurgery in 1954. In 1970, the Division of Neurosurgery of the Department of Surgery was combined with the Division of Neurology to create the joint Department of Neurology and Neurosurgery. A separate Department of Neurosurgery was established in 1981. Four individuals have served as chairmen of the Department of Neurosurgery at HFH, i.e., Albert Crawford (1926-1952), Robert Knighton (1952-1978), James Ausman (1978-1991), and Mark Rosenblum (1992 to the present). During the 1980s and 1990s, HFH evolved into the vertically integrated, regionally distributed Henry Ford Health System. Under the current direction of Dr. Rosenblum, the Department of Neurosurgery at HFH has grown to include 11 full-time neurosurgeons, 2 neuro-oncologists, and 3 investigators with Ph.D. degrees and has recently expanded into three additional hospitals in southeastern Michigan, paralleling the growth of the system. The faculty annually treats more than 2,000 cases in

  6. Augmented-reality integrated robotics in neurosurgery: are we there yet?

    PubMed

    Madhavan, Karthik; Kolcun, John Paul G; Chieng, Lee Onn; Wang, Michael Y

    2017-05-01

    Surgical robots have captured the interest-if not the widespread acceptance-of spinal neurosurgeons. But successful innovation, scientific or commercial, requires the majority to adopt a new practice. "Faster, better, cheaper" products should in theory conquer the market, but often fail. The psychology of change is complex, and the "follow the leader" mentality, common in the field today, lends little trust to the process of disseminating new technology. Beyond product quality, timing has proven to be a key factor in the inception, design, and execution of new technologies. Although the first robotic surgery was performed in 1985, scant progress was seen until the era of minimally invasive surgery. This movement increased neurosurgeons' dependence on navigation and fluoroscopy, intensifying the drive for enhanced precision. Outside the field of medicine, various technology companies have made great progress in popularizing co-robots ("cobots"), augmented reality, and processor chips. This has helped to ease practicing surgeons into familiarity with and acceptance of these technologies. The adoption among neurosurgeons in training is a "follow the leader" phenomenon, wherein new surgeons tend to adopt the technology used during residency. In neurosurgery today, robots are limited to computers functioning between the surgeon and patient. Their functions are confined to establishing a trajectory for navigation, with task execution solely in the surgeon's hands. In this review, the authors discuss significant untapped technologies waiting to be used for more meaningful applications. They explore the history and current manifestations of various modern technologies, and project what innovations may lie ahead.

  7. Biases in the experimental annotations of protein function and their effect on our understanding of protein function space.

    PubMed

    Schnoes, Alexandra M; Ream, David C; Thorman, Alexander W; Babbitt, Patricia C; Friedberg, Iddo

    2013-01-01

    The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the "few articles - many proteins" phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments.

  8. Biases in the Experimental Annotations of Protein Function and Their Effect on Our Understanding of Protein Function Space

    PubMed Central

    Schnoes, Alexandra M.; Ream, David C.; Thorman, Alexander W.; Babbitt, Patricia C.; Friedberg, Iddo

    2013-01-01

    The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the “few articles - many proteins” phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments. PMID:23737737

  9. Investigating the Scope of Resident Patient Care Handoffs within Neurosurgery

    PubMed Central

    Babu, Maya A.; Nahed, Brian V.; Heary, Robert F.

    2012-01-01

    Introduction Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. Methods A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs. Survey results were analyzed using tabulations. Results 449 surveys were completed yielding a 56% response rate. 63% of neurosurgical residents surveyed had not received formal instruction in what constitutes an effective handoff; 24% believe there is high to moderate variability among their co-residents in terms of the quality of the handoff provided; 55% experience three or more interruptions during handoffs on average. 90% of neurosurgical residents surveyed say that handoff most often occurs in a quiet, private area and 56% report a high level of comfort for knowing the potential acute, critical issues affecting a patient when receiving a handoff. Conclusions There needs to be more focused education devoted to learning effective patient-care handoffs in neurosurgical training programs. Increasingly, handing off a patient adequately and safely is becoming a required skill of residency. PMID:22848615

  10. Biomedical publication for neurosurgery residents: a program and guide.

    PubMed

    Eastwood, S; Derish, P A; Berger, M S

    2000-09-01

    One of the most pressing obligations in academic neurosurgery is the publication of clinical and basic science research results. Publication documents intellectual property and communicates findings among researchers working to improve neurosurgical treatment. It documents productivity, justifies funding for research, creates reputations, and builds careers. Nonetheless, the actual writing of reports is a skill often learned by osmosis in academic medicine. To give residents the tools necessary to negotiate the biomedical publication process successfully, we developed a publications program based on the premise that residents seeking an academic career must be prepared to generate publishable reports with maximum efficiency. The program consists of a "publication kit," a series of seminars, and one-on-one tutorials with academic biomedical editors that permit residents individually to improve the quality of their reporting. We describe this program, provide guidelines that can help residents write high-quality papers and publish their work more efficiently, and summarize important content regarding the framework for a successful paper, the elements of a conventional research report, brief guidelines for specific types of papers, reporting standards for clinical trials and meta-analyses, keys to citation in bibliographic indexes, and ethical and legal considerations related to research approval, confidentiality requirements, copyright law, permission to use previously published material, and conflict of interest. Residents who are able to view their work with a sharp critical focus and are educated about the standards of biomedical publication are better prepared to succeed in building a career in academic medicine.

  11. Three-dimensional printing: technologies, applications, and limitations in neurosurgery.

    PubMed

    Pucci, Josephine U; Christophe, Brandon R; Sisti, Jonathan A; Connolly, Edward S

    2017-09-01

    Three-dimensional (3D) printers are a developing technology penetrating a variety of markets, including the medical sector. Since its introduction to the medical field in the late 1980s, 3D printers have constructed a range of devices, such as dentures, hearing aids, and prosthetics. With the ultimate goals of decreasing healthcare costs and improving patient care and outcomes, neurosurgeons are utilizing this dynamic technology, as well. Digital Imaging and Communication in Medicine (DICOM) can be translated into Stereolithography (STL) files, which are then read and methodically built by 3D Printers. Vessels, tumors, and skulls are just a few of the anatomical structures created in a variety of materials, which enable surgeons to conduct research, educate surgeons in training, and improve pre-operative planning without risk to patients. Due to the infancy of the field and a wide range of technologies with varying advantages and disadvantages, there is currently no standard 3D printing process for patient care and medical research. In an effort to enable clinicians to optimize the use of additive manufacturing (AM) technologies, we outline the most suitable 3D printing models and computer-aided design (CAD) software for 3D printing in neurosurgery, their applications, and the limitations that need to be overcome if 3D printers are to become common practice in the neurosurgical field. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Using Electronic Noses to Detect Tumors During Neurosurgery

    NASA Technical Reports Server (NTRS)

    Homer, Margie L.; Ryan, Margaret A.; Lara, Liana M.; Kateb, Babak; Chen, Mike

    2008-01-01

    It has been proposed to develop special-purpose electronic noses and algorithms for processing the digitized outputs of the electronic noses for determining whether tissue exposed during neurosurgery is cancerous. At present, visual inspection by a surgeon is the only available intraoperative technique for detecting cancerous tissue. Implementation of the proposal would help to satisfy a desire, expressed by some neurosurgeons, for an intraoperative technique for determining whether all of a brain tumor has been removed. The electronic-nose technique could complement multimodal imaging techniques, which have also been proposed as means of detecting cancerous tissue. There are also other potential applications of the electronic-nose technique in general diagnosis of abnormal tissue. In preliminary experiments performed to assess the viability of the proposal, the problem of distinguishing between different types of cultured cells was substituted for the problem of distinguishing between normal and abnormal specimens of the same type of tissue. The figure presents data from one experiment, illustrating differences between patterns that could be used to distinguish between two types of cultured cancer cells. Further development can be expected to include studies directed toward answering questions concerning not only the possibility of distinguishing among various types of normal and abnormal tissue but also distinguishing between tissues of interest and other odorous substances that may be present in medical settings.

  13. Turkish Contribution to Journal of Neurosurgery and to Acta Neurochirurgica.

    PubMed

    Altinörs, Nur; Cömert, Serhat; Sönmez, Erkin; Altinel, Faruk

    2016-04-20

    The aim of this study was to evaluate the contribution of Turkish scientists to four journals published by Journal of Neurosurgery Publishing Group and to Acta Neurochirurgica(AN) and to its Supplement (ANS). We reviewed every issue of those journals to December 2015 for the total number of articles , articles produced from studies done entirely in Turkey and for publications overseas coauthored by the Turkish scientists using the websites of these journals. Citations were searched using "Web of Science" and "Google Scholar". Total number of articles published were 19822 for JNS, 3227 for JNS Spine, 2526 for JNS Pediatrics and 2997 for Neurosurgical Focus. Turkish contribution was 556 articles. 337 ( 60.61 %) articles were products of studies performed entirely in Turkey, while 219 ( 39.38 %) articles came from overseas coauthored by Turkish scientists. Overall contribution was 1.94 % . Total of 6469 articles were published in AN. 340 papers were studies performed entirely in Turkey. Turkish scientists working overseas coauthored 37 articles. Total contribution was 377 articles ( 5.82 %) . 4134 papers had been published in ANS. Contribution was 69 articles (1.66 %). Turkish contribution to these journals have started late, the gap has been compensated with publications in the last two decades. Manuscripts of higher scientific level with greater number of citations are needed.

  14. Evaluation of a synergistically controlled semiautomatic trepanation system for neurosurgery.

    PubMed

    Follmann, Axel; Korff, Alexander; Furtjes, Tobias; Lauer, Wolfgang; Kunze, Sandra C; Schmieder, Kirsten; Radermacher, Klaus

    2010-01-01

    One of the most common procedures in neurosurgery is the trepanation of the skull. In this paper, a synergistically controlled handheld tool for trepanation is introduced. This instrument is envisioned to reduce problems of dural tears and wide cutting gaps by combining a soft tissue preserving saw with an automatic regulation of the cutting depth. Since usability and safety of the semi-automatic handheld device are of utmost importance, the complex interaction between the user and the system has been analyzed extensively. Based on prospective usability evaluation the user interaction design and the corresponding user-interface were developed. The compliance with the relevant factors effectiveness, efficiency, error tolerance, learnability and user satisfaction was measured in user-centered experiments to evaluate the usability of the semiautomatic trepanation system. The results confirm the user interaction design of the semiautomatic trepanation system and the corresponding safety strategy. The system seems to integrate itself smoothly into the existing workflow and keeps the surgeon aware of the process.

  15. Clinical Characteristics of Patients with Trigeminal Neuralgia Referred to Neurosurgery

    PubMed Central

    Siqueira, Silvia RDT; Teixeira, Manoel J; Siqueira, José TT

    2009-01-01

    Objectives To investigate the clinical characteristics of patients with trigeminal neuralgia referred to surgery in a center of reference. Methods We evaluated the general characteristics of 395 patients with trigeminal neuralgia referred to neurosurgery as treatment. They corresponded to 2 samples of 1984 and 2004. The EDOF-HC protocol (Orofacial Pain Questionnaire) and the medical profile were used. Results In the first study (1984), with 290 patients, the higher prevalence was: women (57.3%), white (95.5%), with mean age of 62.5. The most affected trigeminal branches were the maxillary and/or mandibular branches (65.5%), and the right side was the most affected (57.6%). From the second study (2004), with 105 patients, 57.1% were women, 75.2% white, with a mean age of 60.8. The maxillary and/or mandibular branches (79.0%) and the right side (69.5%) were the most affected. Both samples had neurological abnormalities and systemic diseases (mainly cardiovascular). Conclusions General characteristics of these patients were similar to other samples of trigeminal neuralgia. Neurological findings were also present in patients with no previous surgical treatment for TN. Hypertension and cardiac diseases were also frequent and make the monitoring of the patients during crises necessary. PMID:19756195

  16. Simulation training in neurosurgery: advances in education and practice

    PubMed Central

    Konakondla, Sanjay; Fong, Reginald; Schirmer, Clemens M

    2017-01-01

    The current simulation technology used for neurosurgical training leaves much to be desired. Significant efforts are thoroughly exhausted in hopes of developing simulations that translate to give learners the “real-life” feel. Though a respectable goal, this may not be necessary as the application for simulation in neurosurgical training may be most useful in early learners. The ultimate uniformly agreeable endpoint of improved outcome and patient safety drives these investments. We explore the development, availability, educational taskforces, cost burdens and the simulation advancements in neurosurgical training. The technologies can be directed at achieving early resident milestones placed by the Accreditation Council for Graduate Medical Education. We discuss various aspects of neurosurgery disciplines with specific technologic advances of simulation software. An overview of the scholarly landscape of the recent publications in the realm of medical simulation and virtual reality pertaining to neurologic surgery is provided. We analyze concurrent concept overlap between PubMed headings and provide a graphical overview of the associations between these terms. PMID:28765716

  17. [Laser acupuncture therapy for pain and vague complaints in neurosurgery].

    PubMed

    Shibuya, M; Ono, R; Fujisawa, K; Katada, K; Sano, H; Kanno, T; Oshiro, T

    1985-06-01

    The value of diode laser acupuncture for pain and other vague neurological complaints has been studied in chronic patients of head trauma and of cerebrovascular disease or neuralgia in head and neck regions. Gallium-Aluminium-Arsenide (Ga-Al-As) diode laser pain attenuator PANALAS-4000 manufactured by Japan Medical Laser Laboratory was used in the following specifications; wave length: 830 nm, power: 20-40 mW, frequency: 5-50 c.p.s., pulse duty: 0.9. The laser acupuncture was applied to some of the representative Chinese meridian points, local pain points and related nerves for 1 to 7 times in a week. It was given in 310 patients in our neurosurgical department. 175 of 227 patients who complained of pain and 12 of 39 patients who complained of numbness showed improvement within 24 hours, another 24 patients with pain and 16 patients with numbness showed improvement after 24 hours. No side effect was noticed. The duration of the effectiveness was about 2 or 3 days. It is very useful to apply the laser acupuncture for pain and vague complaints in neurosurgery.

  18. Difficult conversations: a national course for neurosurgery residents in physician-patient communication.

    PubMed

    Haglund, Michael M; Rudd, Mariah; Nagler, Alisa; Prose, Neil S

    2015-01-01

    To describe the design, content, implementation, and evaluation of a national curriculum for teaching practical skills in empathic communication to residents in neurosurgery. Based on needs assessed through a national survey of neurosurgery program directors, videotaped scenarios using standardized patients illustrating good and bad communication skills were developed. Presurveys and postsurveys were conducted querying participants on their level of competence and the specific behaviors they would attempt to change following participation. A subgroup of residents was evaluated before and after the training based on videotaped role-play exercises. A pilot study was conducted at the authors' institution and later implemented at National Neurosurgery Boot Camps. A total of 14 Duke graduate medical education neurosurgery residents agreed to participate in the pilot study. From across the country, 93 residents (representing 59 institutions) participated in the communication training as part of the Neurosurgery Boot camps, 11 of whom volunteered to participate in a role-playing session before and after the formal teaching session. Most of the neurosurgery program directors responding to the survey indicated that an interactive online communication-training module would be of value (77%). A total of 93 residents participated in communication training as part of the Neurosurgery Boot Camps. Approximately half of the residents reported having no formal physician-patient communication training. Presurvey and postsurvey results showed significant improvement in several of the communication scenarios. Those who participated in role-play showed significant improvement in "asking open-ended questions," "listening," "fire warning shot," "allowing patient to absorb," and "explaining in clear language." Neurosurgeons frequently participate in difficult conversations. Both residents and faculty note that exposure to this content is suboptimal. A hybrid approach to teaching

  19. Experimental evidence for strong stabilizing forces at high functional diversity of aquatic microbial communities.

    PubMed

    Carrara, Francesco; Giometto, Andrea; Seymour, Mathew; Rinaldo, Andrea; Altermatt, Florian

    2015-05-01

    Unveiling the mechanisms that promote coexistence in biological communities is a fundamental problem in ecology. Stable coexistence of many species is commonly observed in natural communities. Most of these natural communities, however, are composed of species from multiple trophic and functional groups, while theory and experiments on coexistence have been focusing on functionally similar species. Here, we investigated how functional diversity affects the stability of species coexistence and productivity in multispecies communities by characterizing experimentally all pairwise species interactions in a pool of 11 species of eukaryotes (10 protists and one rotifer) belonging to three different functional groups. Species within the same functional group showed stronger competitive interactions compared to among-functional group interactions. This often led to competitive exclusion between species that had higher functional relatedness, but only at low levels of species richness. Communities with higher functional diversity resulted in increased species coexistence and community biomass production. Our experimental findings and the results of a stochastic model tailored to the experimental interaction matrix suggest the emergence of strong stabilizing forces when species from different functional groups interact in a homogeneous environment. By combining theoretical analysis with experiments we could also disentangle the relationship between species richness and functional diversity, showing that functional diversity per se is a crucial driver of productivity and stability in multispecies community.

  20. Examining the Function of Problem Behavior in Fragile X Syndrome: Preliminary Experimental Analysis

    ERIC Educational Resources Information Center

    Langthorne, Paul; McGill, Peter; O'Reilly, Mark F.; Lang, Russell; Machalicek, Wendy; Chan, Jeffrey Michael; Rispoli, Mandy

    2011-01-01

    Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis…

  1. Examining the Function of Problem Behavior in Fragile X Syndrome: Preliminary Experimental Analysis

    ERIC Educational Resources Information Center

    Langthorne, Paul; McGill, Peter; O'Reilly, Mark F.; Lang, Russell; Machalicek, Wendy; Chan, Jeffrey Michael; Rispoli, Mandy

    2011-01-01

    Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis…

  2. Effects of Physical Activity on Children's Executive Function: Contributions of Experimental Research on Aerobic Exercise

    ERIC Educational Resources Information Center

    Best, John R.

    2010-01-01

    Executive function refers to the cognitive processes necessary for goal-directed cognition and behavior, which develop across childhood and adolescence. Recent experimental research indicates that both acute and chronic aerobic exercise promote children's executive function. Furthermore, there is tentative evidence that not all forms of aerobic…

  3. Effects of Physical Activity on Children's Executive Function: Contributions of Experimental Research on Aerobic Exercise

    ERIC Educational Resources Information Center

    Best, John R.

    2010-01-01

    Executive function refers to the cognitive processes necessary for goal-directed cognition and behavior, which develop across childhood and adolescence. Recent experimental research indicates that both acute and chronic aerobic exercise promote children's executive function. Furthermore, there is tentative evidence that not all forms of aerobic…

  4. Neurosurgery value and quality in the context of the Affordable Care Act: a policy perspective.

    PubMed

    Menger, Richard P; Guthikonda, Bharat; Storey, Christopher M; Nanda, Anil; McGirt, Matthew; Asher, Anthony

    2015-12-01

    Neurosurgeons provide direct individualized care to patients. However, the majority of regulations affecting the relative value of patient-related care are drafted by policy experts whose focus is typically system- and population-based. A central, prospectively gathered, national outcomes-related database serves as neurosurgery's best opportunity to bring patient-centered outcomes to the policy arena. In this study the authors analyze the impact of the Affordable Care Act (ACA) on the determination of quality and value in neurosurgery care through the scope, language, and terminology of policy experts. The methods by which the ACA came into law and the subsequent quality implications this legislation has for neurosurgery will be discussed. The necessity of neurosurgical patient-oriented clinical registries will be discussed in the context of imminent and dramatic reforms related to medical cost containment. In the policy debate moving forward, the strength of neurosurgery's argument will rest on data, unity, and proactiveness. The National Neurosurgery Quality and Outcomes Database (N(2)QOD) allows neurosurgeons to generate objective data on specialty-specific value and quality determinations; it allows neurosurgeons to bring the patient-physician interaction to the policy debate.

  5. Robotics in neurosurgery: state of the art and future technological challenges.

    PubMed

    Zamorano, L; Li, Q; Jain, S; Kaur, G

    2004-06-01

    The use of robotic technologies to assist surgeons was conceptually described almost thirty years ago but has only recently become feasible. In Neurosurgery, medical robots have been applied to neurosurgery for over 19 years. Nevertheless this field remains unknown to most neurosurgeons. The intrinsic characteristics of robots, such as high precision, repeatability and endurance make them ideal surgeon's assistants. Unfortunately, limitations in the current available systems make its use limited to very few centers in the world. During the last decade, important efforts have been made between academic and industry partnerships to develop robots suitable for use in the operating room environment. Although some applications have been successful in areas of laparoscopic surgery and orthopaedics, Neurosurgery has presented a major challenge due to the eloquence of the surrounding anatomy. This review focuses on the application of medical robotics in neurosurgery. The paper begins with an overview of the development of the medical robotics, followed by the current clinical applications in neurosurgery and an analysis of current limitations. We discuss robotic applications based in our own experience in the field. Next, we discuss the technological challenges and research areas to overcome those limitations, including some of our current research approaches for future progress in the field.

  6. History of the Neurosurgery Department of Pontificia Universidad Catolica, Santiago, Chile.

    PubMed

    Sfeir, Felipe; Villanueva, Pablo; Tagle, Patricio

    2017-01-01

    Pontificia Universidad Católica de Chile's medical school was founded in 1929. An interest in neurosurgical development arose in the minds of the Dean, Dr. Cristobal Espíldora, and the Chief of Surgery, Dr. Rodolfo Rencoret, in 1946. They encouraged and supported Dr. J. Ricardo Olivares to specialize in Neurosurgery with Professor H. Olivecrona in Stockholm, Sweden. The first neurosurgical procedure in the Hospital Clínico de la Universidad Católica was performed in 1950. Since then, intensive efforts have been made to develop neurosurgery and its science. As a result, it is now a center capable of achieving high-quality standards in vascular, oncologic, and endoscopic neurosurgery; stereotactic and radiosurgery; complex spine surgery; pediatric neurosurgery; and epilepsy surgery. This article tells the story of a university hospital neurosurgery service in a country at the southern end of the world and how it became one of the most important neurosurgical centers in Chile and South America.

  7. Reproducibility and variability of the cost functions reconstructed from experimental recordings in multifinger prehension.

    PubMed

    Niu, Xun; Latash, Mark L; Zatsiorsky, Vladimir M

    2012-01-01

    The study examines whether the cost functions reconstructed from experimental recordings are reproducible over time. Participants repeated the trials on three days. By following Analytical Inverse Optimization procedures, the cost functions of finger forces were reconstructed for each day. The cost functions were found to be reproducible over time: application of a cost function C(i) to the data of Day j (i≠j) resulted in smaller deviations from the experimental observations than using other commonly used cost functions. Other findings are: (a) the 2nd order coefficients of the cost function showed negative linear relations with finger force magnitudes; (b) the finger forces were distributed on a 2-dimensional plane in the 4-dimensional finger force space for all subjects and all testing sessions; (c) the data agreed well with the principle of superposition, i.e. the action of object prehension can be decoupled into the control of rotational equilibrium and slipping prevention.

  8. Linking functional group richness and ecosystem functions of dung beetles: an experimental quantification.

    PubMed

    Milotić, Tanja; Quidé, Stijn; Van Loo, Thomas; Hoffmann, Maurice

    2017-01-01

    Dung beetles form an insect group that fulfils important functions in terrestrial ecosystems throughout the world. These include nutrient cycling through dung removal, soil bioturbation, plant growth, secondary seed dispersal and parasite control. We conducted field experiments at two sites in the northern hemisphere temperate region in which dung removal and secondary seed dispersal were assessed. Dung beetles were classified in three functional groups, depending on their size and dung manipulation method: dwellers, large and small tunnelers. Other soil inhabiting fauna were included as a fourth functional group. Dung removal and seed dispersal by each individual functional group and combinations thereof were estimated in exclusion experiments using different dung types. Dwellers were the most diverse and abundant group, but tunnelers were dominant in terms of biomass. All dung beetle functional groups had a clear preference for fresh dung. The ecosystem services in dung removal and secondary seed dispersal provided by dung beetles were significant and differed between functional groups. Although in absolute numbers more dwellers were found, large tunnelers were disproportionally important for dung burial and seed removal. In the absence of dung beetles, other soil inhabiting fauna, such as earthworms, partly took over the dung decomposing role of dung beetles while most dung was processed when all native functional groups were present. Our results, therefore, emphasize the need to conserve functionally complete dung ecosystems to maintain full ecosystem functioning.

  9. National survey on postoperative care and treatment circuits in neurosurgery.

    PubMed

    Valero, R; Carrero, E; Fàbregas, N; Iturri, F; Saiz-Sapena, N; Valencia, L

    2017-10-01

    The analysis of surgical processes should be a standard of health systems. We describe the circuit of care and postoperative treatment for neurosurgical interventions in the centres of our country. From June to October 2014, a survey dealing with perioperative treatments and postoperative circuits after neurosurgical procedures was sent to the chiefs of Anaesthesiology of 73 Spanish hospitals with neurosurgery and members of the Neuroscience Section of SEDAR. We obtained 45 responses from 30 centres (41.09%). Sixty percent of anaesthesiologists perform preventive locoregional analgesic treatment. Pain intensity is systematically assessed by 78%. Paracetamol, non-steroidal anti-inflammatory and morphine combinations are the most commonly used. A percentage of 51.1 are aware of the incidence of postoperative nausea after craniotomy and 86.7% consider multimodal prophylaxis to be necessary. Dexamethasone is given as antiemetic (88.9%) and/or anti-oedema treatment (68.9%). A percentage of 44.4 of anaesthesiologists routinely administer anticonvulsive prophylaxis in patients with supratentorial tumours (levetiracetam, 88.9%), and 73.3% of anaesthesiologists have postoperative surveillance protocols. The anaesthesiologist (73.3%) decides the patient's destination, which is usually ICU (83.3%) or PACU (50%). Postoperative neurological monitoring varied according to the type of intervention, although strength and sensitivity were explored in between 70-80%. There is great variability in the responses, probably attributable to the absence of guidelines, different structures and hospital equipment, type of surgery and qualified personnel. We need consensual protocols to standardize the treatment and the degree of monitoring needed during the postoperative period. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Robotic System for MRI-Guided Stereotactic Neurosurgery

    PubMed Central

    Li, Gang; Cole, Gregory A.; Shang, Weijian; Harrington, Kevin; Camilo, Alex; Pilitsis, Julie G.; Fischer, Gregory S.

    2015-01-01

    Stereotaxy is a neurosurgical technique that can take several hours to reach a specific target, typically utilizing a mechanical frame and guided by preoperative imaging. An error in any one of the numerous steps or deviations of the target anatomy from the preoperative plan such as brain shift (up to 20 mm), may affect the targeting accuracy and thus the treatment effectiveness. Moreover, because the procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization, the intervention is basically “blind” for the operator with limited means of intraoperative confirmation that may result in reduced accuracy and safety. The presented system is intended to address the clinical needs for enhanced efficiency, accuracy, and safety of image-guided stereotactic neurosurgery for Deep Brain Stimulation (DBS) lead placement. The work describes a magnetic resonance imaging (MRI)-guided, robotically actuated stereotactic neural intervention system for deep brain stimulation procedure, which offers the potential of reducing procedure duration while improving targeting accuracy and enhancing safety. This is achieved through simultaneous robotic manipulation of the instrument and interactively updated in situ MRI guidance that enables visualization of the anatomy and interventional instrument. During simultaneous actuation and imaging, the system has demonstrated less than 15% signal-to-noise ratio (SNR) variation and less than 0.20% geometric distortion artifact without affecting the imaging usability to visualize and guide the procedure. Optical tracking and MRI phantom experiments streamline the clinical workflow of the prototype system, corroborating targeting accuracy with 3-axis root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58° in insertion angle. PMID:25376035

  11. Innovation in neurosurgery: less than IDEAL? A systematic review.

    PubMed

    Muskens, I S; Diederen, S J H; Senders, J T; Zamanipoor Najafabadi, A H; van Furth, W R; May, A M; Smith, T R; Bredenoord, A L; Broekman, M L D

    2017-08-06

    Surgical innovation is different from the introduction of novel pharmaceuticals. To help address this, in 2009 the IDEAL Collaboration (Idea, Development, Exploration, Assessment, Long-term follow-up) introduced the five-stage framework for surgical innovation. To evaluate the framework feasibility for novel neurosurgical procedure introduction, two innovative surgical procedures were examined: the endoscopic endonasal approach for skull base meningiomas (EEMS) and the WovenEndobridge (WEB device) for endovascular treatment of intracranial aneurysms. The published literature on EEMS and WEB devices was systematically reviewed. Identified studies were classified according to the IDEAL framework stage. Next, studies were evaluated for possible categorization according to the IDEAL framework. Five hundred seventy-six papers describing EEMS were identified of which 26 papers were included. No prospective studies were identified, and no studies reported on ethical approval or patient informed consent for the innovative procedure. Therefore, no clinical studies could be categorized according to the IDEAL Framework. For WEB devices, 6229 articles were screened of which 21 were included. In contrast to EEMS, two studies were categorized as 2a and two as 2b. The results of this systematic review demonstrate that both EEMS and WEB devices were not introduced according to the (later developed in the case of EEMS) IDEAL framework. Elements of the framework such as informed consent, ethical approval, and rigorous outcomes reporting are important and could serve to improve the quality of neurosurgical research. Alternative study designs and the use of big data could be useful modifications of the IDEAL framework for innovation in neurosurgery.

  12. Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders

    PubMed Central

    Nuttin, Bart; Wu, Hemmings; Mayberg, Helen; Hariz, Marwan; Gabriëls, Loes; Galert, Thorsten; Merkel, Reinhard; Kubu, Cynthia; Vilela-Filho, Osvaldo; Matthews, Keith; Taira, Takaomi; Lozano, Andres M; Schechtmann, Gastón; Doshi, Paresh; Broggi, Giovanni; Régis, Jean; Alkhani, Ahmed; Sun, Bomin; Eljamel, Sam; Schulder, Michael; Kaplitt, Michael; Eskandar, Emad; Rezai, Ali; Krauss, Joachim K; Hilven, Paulien; Schuurman, Rick; Ruiz, Pedro; Chang, Jin Woo; Cosyns, Paul; Lipsman, Nir; Voges, Juergen; Cosgrove, Rees; Li, Yongjie; Schlaepfer, Thomas

    2014-01-01

    Background For patients with psychiatric illnesses remaining refractory to ‘standard’ therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. Methods To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. Findings The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered ‘established’ in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients. Interpretation This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety. PMID:24444853

  13. Operative Duration and Risk of Surgical Site Infection in Neurosurgery.

    PubMed

    Bekelis, Kimon; Coy, Shannon; Simmons, Nathan

    2016-10-01

    The association of surgical duration with the risk of surgical site infection (SSI) has not been quantified in neurosurgery. We investigated the association of operative duration in neurosurgical procedures with the incidence of SSI. We performed a retrospective cohort study involving patients who underwent neurosurgical procedures from 2005 to 2012 and were registered in the American College of Surgeons National Quality Improvement Project registry. To control for confounding, we used multivariable regression models and propensity score conditioning. During the study period there were 94,744 patients who underwent a neurosurgical procedure and met the inclusion criteria. Of these patients, 4.1% developed a postoperative SSI within 30 days. Multivariable logistic regression showed an association between longer operative duration with higher incidence of SSI (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.16-1.20). Compared with procedures of moderate duration (third quintile, 40th-60th percentile), patients undergoing the longest procedures (>80th percentile) had higher odds (OR, 2.07; 95% CI, 1.86-2.31) of developing SSI. The shortest procedures (<20th percentile) were associated with decreased incidence of SSI (OR, 0.72; 95% CI, 0.61-0.83) compared with those of moderate duration. The same associations were present in propensity score adjusted models and models stratified by subgroups of cranial, spinal, peripheral nerve, and carotid procedures. In a cohort of patients from a national prospective surgical registry, longer operative duration was associated with increased incidence of SSI for neurosurgical procedures. These results can be used by neurosurgeons to inform operative management and to stratify patients with regard to SSI risk. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Sensors management in robotic neurosurgery: the ROBOCAST project.

    PubMed

    Vaccarella, Alberto; Comparetti, Mirko Daniele; Enquobahrie, Andinet; Ferrigno, Giancarlo; De Momi, Elena

    2011-01-01

    Robot and computer-aided surgery platforms bring a variety of sensors into the operating room. These sensors generate information to be synchronized and merged for improving the accuracy and the safety of the surgical procedure for both patients and operators. In this paper, we present our work on the development of a sensor management architecture that is used is to gather and fuse data from localization systems, such as optical and electromagnetic trackers and ultrasound imaging devices. The architecture follows a modular client-server approach and was implemented within the EU-funded project ROBOCAST (FP7 ICT 215190). Furthermore it is based on very well-maintained open-source libraries such as OpenCV and Image-Guided Surgery Toolkit (IGSTK), which are supported from a worldwide community of developers and allow a significant reduction of software costs. We conducted experiments to evaluate the performance of the sensor manager module. We computed the response time needed for a client to receive tracking data or video images, and the time lag between synchronous acquisition with an optical tracker and ultrasound machine. Results showed a median delay of 1.9 ms for a client request of tracking data and about 40 ms for US images; these values are compatible with the data generation rate (20-30 Hz for tracking system and 25 fps for PAL video). Simultaneous acquisitions have been performed with an optical tracking system and US imaging device: data was aligned according to the timestamp associated with each sample and the delay was estimated with a cross-correlation study. A median value of 230 ms delay was calculated showing that realtime 3D reconstruction is not feasible (an offline temporal calibration is needed), although a slow exploration is possible. In conclusion, as far as asleep patient neurosurgery is concerned, the proposed setup is indeed useful for registration error correction because the brain shift occurs with a time constant of few tens of minutes.

  15. Strategic design for pediatric neurosurgery missions across the Western Hemisphere

    PubMed Central

    Hambrecht, Amanda; Duenas, Matthew J.; Hahn, Edward J.; Aryan, Henry E.; Hughes, Samuel A.; Waters, Dawn; Levy, Michael L.; Jandial, Rahul

    2013-01-01

    Background: With growing interest in global health, surgeons have created outreach missions to improve health care disparities in less developed countries. These efforts are mainly episodic with visiting surgeons performing the operations and minimal investment in local surgeon education. To create real and durable advancement in surgical services in disciplines that require urgent patient care, such as pediatric neurosurgery, improving the surgical armamentarium of the local surgeons must be the priority. Methods: We propose a strategic design for extending surgical education missions throughout the Western Hemisphere in order to transfer modern surgical skills to local neurosurgeons. A selection criteria and structure for targeted missions is a derivative of logistical and pedagogical lessons ascertained from previous missions by our teams in Peru and Ukraine. Results: Outreach programs should be applied to hospitals in capital cities to serve as a central referral center for maximal impact with fiscal efficiency. The host country should fulfill several criteria, including demonstration of geopolitical stability in combination with lack of modern neurosurgical care and equipment. The mission strategy is outlined as three to four 1-week visits with an initial site evaluation to establish a relationship with the hospital administration and host surgeons. Each visit should be characterized by collaboration between visiting and host surgeons on increasingly complex cases, with progressive transfer of skills over time. Conclusion: A strategic approach for surgical outreach missions should be built on collaboration and camaraderie between visiting and local neurosurgeons, with the mutual objective of cost-effective targeted renovation of their surgical equipment and skill repertoire. PMID:23772332

  16. Acute care in neurosurgery: quantity, quality, and challenges

    PubMed Central

    Schuhmann, M; Rickels, E; Rosahl, S; Schneekloth, C; Samii, M

    2001-01-01

    OBJECTIVE—Part of the daily routine in neurosurgery is the treatment of emergency room admissions, and acute cases from other departments or from outside hospitals. This acute care is not normally included in performance figures or budget management, nor analysed scientifically in respect of quantity and quality of care provided by neurosurgeons.
METHOD—Over a 1 year period, all acute care cases managed by two neurosurgical on call teams in a large northern German city, were recorded prospectively on a day by day basis. A large database of 1819 entries was created and analysed using descriptive statistics.
RESULTS—The minimum incidence of patients requiring neurosurgical acute care was estimated to be 75-115/100 000 inhabitants/year. This corresponds to a mean of about 6/day. Only 30% of patients came directly via the emergency room. The fate of 70% of patients depended initially on the "neurosurgical qualification" of primary care doctors and here deficits existed. Although most intracerebral and subarachnoid haemorrhages were managed with the participation of neurosurgeons, they were not involved in the management of most mild and moderate traumatic brain injuries. Within 1 year the additional workload from acute care amounted to 1000 unplanned admissions, 900 acute imaging procedures, and almost 400 emergency operations.
CONCLUSION—The current policy in public health, which includes cuts in resources, transport facilities, and manpower, is not compatible with the demonstrated extent of acute neurosurgical care. In addition to routine elective work, many extra admissions, evening or night time surgery, and imaging procedures have to be accomplished. An education programme for generalists is required to improve overall patient outcome. These conclusions hold special importance if health authorities wish to not only maintain present standards but aim to improve existing deficits.

 PMID:11459889

  17. Smartphones in remote medicine and daily neurosurgery: The Sabah update

    PubMed Central

    Perumall, Vinodh Vayara; Sellamuthu, Pulivendhan; Harun, Rahmat; Zenian, Mohd Sofan

    2015-01-01

    Introduction: Healthcare costs continue to rise every day as the demand outgrows the supply of surgeons. The application of telephone consultation for immediate management is needed as most neurosurgeons are technology orientated. This enables a specialist at a remote mobile site to receive the necessary information and reduce transmission time, from the second the patient is seen till the management is obtained. Materials and Methods: We conducted a survey on smartphone ownership among doctors and gathered cases that needed neurosurgical input from 1st November 2012 till 30th April 2013 from all 24 district hospitals in Sabah, Malaysia. Results: The percentage of smartphone ownership among doctors surveyed and usage of it for remote and daily medicine at various departments at Queen Elizabeth Hospital, Kota Kinabalu, which shows at least 90% smartphone ownership and proves 100% ownership of cross-platform instant messaging applications and its usage for remote and daily medicine. It also proves to be a more popular mode of referral compared to “teleconsultation” (TC). Discussion: In Sabah, the TC service is used for remote medical consultation and only available at four hospitals. The sender needs direct access to a computer with the TC software, and it causes delay whereas doctors using smartphones will just need to discuss the case on the spot and obtain the appropriate management within minutes. Smartphone usage is also important in daily neurosurgery especially at the department level to promote efficient communication, organization, and interaction between all the staff. As for the department's administrative sector, it is useful to notify if anyone is on leave, attending courses or even meetings as the shortage can be avoided, and redistribution easily done. It also allows us to transfer simple intra-departmental data at any time, and any place whenever required. Conclusion: With all the given fact, it is clear that a day without utilizing this service

  18. Simulation of brain tumor resection in image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

    Fan, Xiaoyao; Ji, Songbai; Fontaine, Kathryn; Hartov, Alex; Roberts, David; Paulsen, Keith

    2011-03-01

    Preoperative magnetic resonance images are typically used for neuronavigation in image-guided neurosurgery. However, intraoperative brain deformation (e.g., as a result of gravitation, loss of cerebrospinal fluid, retraction, resection, etc.) significantly degrades the accuracy in image guidance, and must be compensated for in order to maintain sufficient accuracy for navigation. Biomechanical finite element models are effective techniques that assimilate intraoperative data and compute whole-brain deformation from which to generate model-updated MR images (uMR) to improve accuracy in intraoperative guidance. To date, most studies have focused on early surgical stages (i.e., after craniotomy and durotomy), whereas simulation of more complex events at later surgical stages has remained to be a challenge using biomechanical models. We have developed a method to simulate partial or complete tumor resection that incorporates intraoperative volumetric ultrasound (US) and stereovision (SV), and the resulting whole-brain deformation was used to generate uMR. The 3D ultrasound and stereovision systems are complimentary to each other because they capture features deeper in the brain beneath the craniotomy and at the exposed cortical surface, respectively. In this paper, we illustrate the application of the proposed method to simulate brain tumor resection at three temporally distinct surgical stages throughout a clinical surgery case using sparse displacement data obtained from both the US and SV systems. We demonstrate that our technique is feasible to produce uMR that agrees well with intraoperative US and SV images after dural opening, after partial tumor resection, and after complete tumor resection. Currently, the computational cost to simulate tumor resection can be up to 30 min because of the need for re-meshing and the trial-and-error approach to refine the amount of tissue resection. However, this approach introduces minimal interruption to the surgical workflow

  19. The first lady president of the ISPN: Prof. Dr. Graciela Zuccaro and her journey through pediatric neurosurgery.

    PubMed

    Tovar-Spinoza, Zulma

    2017-06-20

    The International Society for Pediatric Neurosurgery (ISPN) was founded in 1972 in Chicago, IL, USA. It has been 45 years since the creation of the ISPN, but it is not until now that the pediatric neurosurgery community has been led by a female neurosurgeon.

  20. Neurosurgery in Turkish poetry: three poets, two poems and two neurosurgeons.

    PubMed

    Kahilogullari, Gokmen

    2015-01-01

    Poems are essential in art and vital organs in literature. Similarly, surgery (and neurosurgery) is also regarded to be an art in medicine. From Hippocrates to nowadays, there is a debate on whether medicine -especially surgery- is a kind of an art or a field of science or a combination of both. This close relation becomes clearer during the practice of surgery, especially in neurosurgery. Herein, the relation between Turkish poetry and Turkish neurosurgery is being presented by researching the interesting and exciting stories about three poets (Can Yücel, Hasan Hüseyin Korkmazgil, Nazım Hikmet), their poems; and two Turkish neurosurgeons (Gazi Yaşargil, Yücel Kanpolat).

  1. Practical guidelines for setting up neurosurgery skills training cadaver laboratory in India.

    PubMed

    Suri, Ashish; Roy, Tara Sankar; Lalwani, Sanjeev; Deo, Rama Chandra; Tripathi, Manjul; Dhingra, Renu; Bhardwaj, Daya Nand; Sharma, Bhawani Shankar

    2014-01-01

    Though the necessity of cadaver dissection is felt by the medical fraternity, and described as early as 600 BC, in India, there are no practical guidelines available in the world literature for setting up a basic cadaver dissection laboratory for neurosurgery skills training. Hands-on dissection practice on microscopic and endoscopic procedures is essential in technologically demanding modern neurosurgery training where ethical issues, cost constraints, medico-legal pitfalls, and resident duty time restrictions have resulted in lesser opportunities to learn. Collaboration of anatomy, forensic medicine, and neurosurgery is essential for development of a workflow of cadaver procurement, preservation, storage, dissection, and disposal along with setting up the guidelines for ethical and legal concerns.

  2. Perioperative posterior reversible encephalopathy syndrome in 2 pediatric neurosurgery patients with brainstem ependymoma.

    PubMed

    Gephart, Melanie G Hayden; Taft, Bonnie P; Giese, Anne-Katrin; Guzman, Raphael; Edwards, Michael S B

    2011-03-01

    Posterior reversible encephalopathy syndrome (PRES) has been described in pediatric neurooncology patients, although it has not been documented perioperatively in pediatric neurosurgery patients not actively receiving chemotherapy. Recently at the authors' facility, 2 cases of PRES were diagnosed perioperatively in children with brainstem ependymoma. Both patients had presented with hypertension, altered mental status, and seizures and demonstrated MR imaging features consistent with PRES. The patients were treated with antiseizure and antihypertension medications, leading to improvement in both clinical symptoms and neuroimaging findings. These cases are the first to document PRES in perioperative pediatric neurosurgery patients not actively receiving chemotherapy. Both patients had ependymoma involving the brainstem, which may have led to intra- and perioperative hemodynamic instability (including hypertension) and predisposed them to this syndrome. An awareness of PRES in similar scenarios will aid in the prevention, diagnosis, and treatment of pediatric neurosurgery patients with this syndrome.

  3. From idea to publication: Publication rates of theses in neurosurgery from Turkey.

    PubMed

    Öğrenci, Ahmet; Ekşi, Murat Şakir; Özcan-Ekşi, Emel Ece; Koban, Orkun

    2016-01-01

    Thesis at the end of residency is considered as the complementary component of postgraduate training. In this respect, thesis helps the residents learn how to ask structured questions, set up the most appropriate study design, conduct the study, retrieve study results and write conclusions with clinical implications. To the best of our knowledge, the publication rates of theses in the field of neurosurgery have not been reported before. Our aim was to find out publication rates of theses in neurosurgery specialty, in this descriptive study. The database of Higher Education Council of Turkey, which includes the theses of residents in only university hospitals, was screened between years 2004 and 2013. After retrieving the theses from the database; we used search engines to find out the theses published in any SCI/SCI-E-indexed journals. For this purpose, the title of the theses and the author names were used as keywords for searching. Data was presented in a descriptive form as absolute numbers and percentages. We retrieved 164 theses written by former residents in neurosurgery using the database. Among 164 theses, 18% (national journals: 9; international journals: 21) were published in SCI/SCI-E indexed journals. Publication rates of theses in neurosurgery are low as they are in the other specialties of medicine. Our study is a descriptive research, to give an idea about publication rates of theses in neurosurgery. Further studies are required to understand the underlying factors, which are responsible for the limited success in publication of theses in neurosurgery. Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  4. Mining high-throughput experimental data to link gene and function

    PubMed Central

    Blaby-Haas, Crysten E.; de Crécy-Lagard, Valérie

    2011-01-01

    Nearly 2200 genomes encoding some 6 million proteins have now been sequenced. Around 40% of these proteins are of unknown function even when function is loosely and minimally defined as “belonging to a superfamily”. In addition to in silico methods, the swelling stream of high-throughput experimental data can give valuable clues for linking these “unknowns” with precise biological roles. The goal is to develop integrative data-mining platforms that allow the scientific community at large to access and utilize this rich source of experimental knowledge. To this end, we review recent advances in generating whole-genome experimental datasets, where this data can be accessed, and how it can be used to drive prediction of gene function. PMID:21310501

  5. Experimental Study of Level Density and {gamma}-strength Functions from Compound Nuclear Reactions

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Massey, T. N.; Schiller, A.; Guttormsen, M.; Siem, S.

    2008-04-17

    The current status of experimental study of level density and {gamma}-strength functions is reviewed. Three experimental techniques are used. These are measurements of particle evaporation spectra from compound nuclear reactions, the measurements of particle-{gamma} coincidences from inelastic scattering and pick-up reactions and the method of two-step {gamma}-cascades following neutron/proton radiative capture. Recent experimental data on level densities from neutron evaporation spectra are shown. The first results on the cascade {gamma}-spectrum from the {sup 59}Co(p,2{gamma}){sup 60}Ni reaction are presented.

  6. Clinical Outcomes of Wulingsan Subtraction Decoction Treatment of Postoperative Brain Edema and Fever as a Complication of Glioma Neurosurgery

    PubMed Central

    Jin, Wei-rong; Zhang, Feng-e; Diao, Bao-zhong; Zhang, Yue-ying

    2016-01-01

    Objective. To evaluate the efficacy of Wulingsan subtraction (五苓散加减 WLSS) decoction in the treatment of postoperative brain edema and fever as a complication of glioma neurosurgery. Methods. This retrospective study was conducted at the Department of Neurosurgery of Liaocheng People's Hospital. Patients hospitalized between March 2011 and December 2014 were divided into three groups: Group A received WLSS oral liquid (50 mL), twice a day; Group B received an intravenous infusion of mannitol; and Group C received WLSS combined with mannitol (n = 30 patients per group). All patients were treated for 10 days continuously. Therapeutic efficacy was evaluated by measuring body temperature and indicators of renal function before and 3, 5, and 10 days after treatment. Results. Compared to the other two groups, significantly greater clinical efficacy was observed in the patients treated with mannitol (Group B; P < 0.05), although marked clinical efficacy was also observed over time in patients treated with WLSS (Group A). After 5 days, the quantifiable effects of the WLSS and mannitol combination group (Group C) were substantial (P < 0.05). The renal damage in Group B was more obvious after 5 days and 10 days. Conclusion. Compared with mannitol treatment alone, WLSS combined with mannitol induced a more rapid reduction in body temperature. Our findings suggest that patients should be started on mannitol for 3 days and then switched to WLSS to achieve obvious antipyretic effects and protect renal function. This method of treatment should be considered for clinical applications. PMID:27019661

  7. Evaluation of Sensory and Motor Skills in Neurosurgery Applicants Using a Virtual Reality Neurosurgical Simulator: The Sensory-Motor Quotient.

    PubMed

    Roitberg, Ben Z; Kania, Patrick; Luciano, Cristian; Dharmavaram, Naga; Banerjee, Pat

    2015-01-01

    Manual skill is an important attribute for any surgeon. Current methods to evaluate sensory-motor skills in neurosurgical residency applicants are limited. We aim to develop an objective multifaceted measure of sensory-motor skills using a virtual reality surgical simulator. A set of 3 tests of sensory-motor function was performed using a 3-dimensional surgical simulator with head and arm tracking, collocalization, and haptic feedback. (1) Trajectory planning: virtual reality drilling of a pedicle. Entry point, target point, and trajectory were scored-evaluating spatial memory and orientation. (2) Motor planning: sequence, timing, and precision: hemostasis in a postresection cavity in the brain. (3) Haptic perception: touching virtual spheres to determine which is softest of the group, with progressive difficulty. Results were analyzed individually and for a combined score of all the tasks. The University of Chicago Hospital's tertiary care academic center. A total of 95 consecutive applicants interviewed at a neurosurgery residency program over 2 years were offered anonymous participation in the study; in 2 cohorts, 36 participants in year 1 and 27 participants in year 2 (validation cohort) agreed and completed all the tasks. We also tested 10 first-year medical students and 4 first- and second-year neurosurgery residents. A cumulative score was generated from the 3 tests. The mean score was 14.47 (standard deviation = 4.37), median score was 13.42, best score was 8.41, and worst score was 30.26. Separate analysis of applicants from each of 2 years yielded nearly identical results. Residents tended to cluster on the better performance side, and first-year students were not different from applicants. (1) Our cumulative score measures sensory-motor skills in an objective and reproducible way. (2) Better performance by residents hints at validity for neurosurgery. (3) We were able to demonstrate good psychometric qualities and generate a proposed sensory

  8. Variation in Spine Surgeon Selection Criteria Between Neurosurgery and Orthopedic Surgery Patients.

    PubMed

    Hijji, Fady Y; Narain, Ankur S; Haws, Brittany E; Witiw, Christopher D; Kudaravalli, Krishna T; Yom, Kelly H; Deutsch, Harel; Singh, Kern

    2017-09-22

    A cross-sectional survey study. The objective of this study is to determine if there are any differences in spine surgeon selection criteria between neurosurgery patients and orthopedic patients. The evolution of the health care delivery system has allowed for increased patient autonomy in provider selection. However, the process and criteria by which patients choose particular spine surgeons is not well understood. Furthermore, differences in physician selection criteria used by patients who present either to a neurosurgery or orthopedic spine surgeon has not been previously established. An anonymous questionnaire consisting of 26 questions was administered to 644 patients seeking treatment from either a single neurosurgery-trained or orthopedics-trained spine surgeon at an urban institution. Four questions pertained to demographic variables. Sixteen questions asked patients to rate specific spine surgeon selection criteria in terms of importance (scale, 1-10). Six questions were multiple choice, asking patients to select their preferences towards aspects of a spine surgeon. Patient responses were compared using χ analysis or Fisher exact test for categorical variables. The 3 most important factors for selecting a spine surgeon were the same for neurosurgery and orthopedic surgery patients: board certification (neurosurgery, orthopedic surgery) (9.07±2.35, 9.22±1.79), in-network provider status (8.01±3.15, 8.09±3.03), and surgeon bedside manner (7.88±2.52, 8.07±2.29). When listing their preference regarding surgeon specialty training, 82.74% of neurosurgery patients and 48.81% of orthopedic surgery patients preferred a surgeon who was trained in neurosurgery. The growth in patient autonomy within the current health care system has emphasized the importance of identifying patient preferences in the physician selection process.Board certification, in-network insurance status, and bedside manner may be the most influential factors for patients in spine surgeon

  9. [Characteristics of perioperative period in Xenon-based combined general anaesthesia in neurosurgery].

    PubMed

    Viatkin, A A; Petrosian, L G; Mizikov, V M; Vasil'ev, S A

    2013-01-01

    Neuroprotection could be the aim to use Xenon for general anesthesia. However the experience of Xenon anesthesia in neurosurgery is quite limited. The appraisal of Xenon based anesthesia was accomplished in 12 patients during various brain surgery. Xe in concentration 65% was used to maintenance of anesthesia, other medication was avoided. As a resuIt there were 8 cases of arterial hypertension and 2 cases of superficial hypnotic state. Excitation (n = 3), hyperdynamic reaction (n = 8), PONV (n = 8) were detected in early postoperative period. An analysis of this study suggests a conclusion that studied method of Xenon-based anesthesia is inexpedient for neurosurgery.

  10. Creating a Culture of Collaboration: A Brief History of Academic Neurosurgery in Washington, DC.

    PubMed

    Siu, Alan; Neal, Christopher J; Syed, Hasan R; Felbaum, Daniel R; Nair, M Nathan; McGrail, Kevin M; Caputy, Anthony J; Shields, Donald C

    2017-04-25

    Clinical neurosurgery has been practiced in the US capital for just over 100 years. As former residents and fellows of Drs. Harvey Cushing and Walter Dandy moved to the region, hospitals at Georgetown and George Washington Universities became early adopters of this new surgical discipline. Later academic neurosurgery programs were established at the National Institutes of Health, Walter Reed Medical Center, and Children's National Medical Center. Neurosurgical pioneers at these institutions developed new technologies and diagnostic procedures which continue to inform our current practice. In addition, continued collaboration between the multiple training sites in Washington, DC has uniquely enriched our residents' training experience. Copyright © 2017 by the Congress of Neurological Surgeons.

  11. Statement of Ethics in Neurosurgery of the World Federation of Neurosurgical Societies.

    PubMed

    Umansky, Felix; Black, Peter L; DiRocco, Concenzio; Ferrer, Enrique; Goel, Atul; Malik, Ghaus M; Mathiesen, Tiit; Mendez, Ivar; Palmer, James D; Juanotena, Jorge Rodriguez; Fraifeld, Shifra; Rosenfeld, Jeffrey V

    2011-01-01

    This Statement of Ethics in Neurosurgery was developed by the Committee for Ethics and Medico-Legal Affairs of the World Federation of Neurosurgical Societies to help neurosurgeons resolve problems in the treatment of individual patients and meet obligations to the larger society. This document is intended as a framework rather than a set of rules. It cannot cover every situation and should be used with flexibility. However, it is our intent that the fundamental principles enunciated here should serve as a guide in the day-to-day practice of neurosurgery.

  12. Experimental measurement of the four-dimensional coherence function for an undulator x-ray source.

    PubMed

    Tran, C Q; Williams, G J; Roberts, A; Flewett, S; Peele, A G; Paterson, D; de Jonge, M D; Nugent, K A

    2007-06-01

    A full measurement of the four-dimensional coherence function from an undulator beam line is reported. The analysis is based on the observation that the data are consistent with a coherence function that is mathematically separable. The effective source size can be altered by changing the width of the exit slit, and the complete coherence function is presented for two settings. We find, to within experimental error, that the four-dimensional complex degree of coherence can be described as a real Gaussian function that depends only on the difference of the spatial coordinates.

  13. Reconstruction of the unknown optimization cost functions from experimental recordings during static multi-finger prehension.

    PubMed

    Niu, Xun; Terekhov, Alexander V; Latash, Mark L; Zatsiorsky, Vladimir M

    2012-04-01

    The goal of the research is to reconstruct the unknown cost (objective) function(s) presumably used by the neural controller for sharing the total force among individual fingers in multifinger prehension. The cost function was determined from experimental data by applying the recently developed Analytical Inverse Optimization (ANIO) method (Terekhov et al. 2010). The core of the ANIO method is the Theorem of Uniqueness that specifies conditions for unique (with some restrictions) estimation of the objective functions. In the experiment, subjects (n = 8) grasped an instrumented handle and maintained it at rest in the air with various external torques, loads, and target grasping forces applied to the object. The experimental data recorded from 80 trials showed a tendency to lie on a 2-dimensional hyperplane in the 4-dimensional finger-force space. Because the constraints in each trial were different, such a propensity is a manifestation of a neural mechanism (not the task mechanics). In agreement with the Lagrange principle for the inverse optimization, the plane of experimental observations was close to the plane resulting from the direct optimization. The latter plane was determined using the ANIO method. The unknown cost function was reconstructed successfully for each performer, as well as for the group data. The cost functions were found to be quadratic with nonzero linear terms. The cost functions obtained with the ANIO method yielded more accurate results than other optimization methods. The ANIO method has an evident potential for addressing the problem of optimization in motor control.

  14. Defensive Medicine in U.S. Spine Neurosurgery.

    PubMed

    Din, Ryan S; Yan, Sandra C; Cote, David J; Acosta, Michael A; Smith, Timothy R

    2017-02-01

    Observational cross-sectional survey. To compare defensive practices of U.S. spine and nonspine neurosurgeons in the context of state medical liability risk. Defensive medicine is a commonly reported and costly phenomenon in neurosurgery. Although state liability risk is thought to contribute greatly to defensive practice, variation within neurosurgical specialties has not been well explored. A validated, online survey was sent via email to 3344 members of the American Board of Neurological Surgeons. The instrument contained eight question domains: surgeon characteristics, patient characteristics, practice type, insurance type, surgeon liability profile, basic surgeon reimbursement, surgeon perceptions of medical legal environment, and the practice of defensive medicine. The overall response rate was 30.6% (n = 1026), including 499 neurosurgeons performing mainly spine procedures (48.6%). Spine neurosurgeons had a similar average practice duration as nonspine neurosurgeons (16.6 vs 16.9 years, P = 0.64) and comparable lifetime case volume (4767 vs 4,703, P = 0.71). The average annual malpractice premium for spine neurosurgeons was similar to nonspine neurosurgeons ($104,480.52 vs $101,721.76, P = 0.60). On average, spine neurosurgeons had a significantly higher rate of ordering labs, medications, referrals, procedures, and imaging solely for liability concerns compared with nonspine neurosurgeons (89.2% vs 84.6%, P = 0.031). Multivariate analysis revealed that spine neurosurgeons were roughly 3 times more likely to practice defensively compared with nonspine neurosurgeons (odds ratio, OR = 2.9, P = 0.001) when controlling for high-risk procedures (OR = 7.8, P < 0.001), annual malpractice premium (OR = 3.3, P = 0.01), percentage of patients publicly insured (OR = 1.1, P = 0.80), malpractice claims in the last 3 years (OR = 1.13, P = 0.71), and state medical-legal environment (OR = 1.3, P = 0

  15. Experimental investigations of the scanning functions of galvanometer-based scanners with applications in OCT.

    PubMed

    Duma, Virgil-Florin; Lee, Kye-sung; Meemon, Panomsak; Rolland, Jannick P

    2011-10-10

    We analyze the three most common profiles of scanning functions for galvanometer-based scanners (GSs): the sawtooth, triangular and sinusoidal functions. They are determined experimentally with regard to the scan parameters of the input signal (i.e., frequency and amplitude). We study the differences of the output function of the GS measured as the positional error of the oscillatory mirror from the ideal function given by the input signal of the device. The limits in achieving the different types of scanning functions in terms of duty cycle and linearity are determined experimentally for the possible range of scan parameters. Of particular importance are the preservation of an imposed duty cycle and profile for the sawtooth function, the quantification of the linearity for the sinusoidal function, and the effective duty cycle for the triangular, as well as for the other functions. The range of scan amplitudes for which the stability of the oscillatory regime of the galvo mirror is stable for different frequencies is also highlighted. While the use of the device in certain scanning regimes is studied, certain rules of thumb are deduced to make the best out of the galvoscanner. Finally, the three types of scanning functions are tested with a Fourier domain optical coherence tomography (FD OCT) setup and the conclusions of the study are demonstrated in an imaging application by correlating the determined limits of the scanning regimes with the requirements of OCT. © 2011 Optical Society of America

  16. IL-9 regulates intestinal barrier function in experimental T cell-mediated colitis

    PubMed Central

    Gerlach, Katharina; McKenzie, Andrew N; Neurath, Markus F; Weigmann, Benno

    2015-01-01

    As previous studies suggested that IL-9 may control intestinal barrier function, we tested the role of IL-9 in experimental T cell-mediated colitis induced by the hapten reagent 2,4,6-trinitrobenzenesulfonic acid (TNBS). The deficiency of IL-9 suppressed TNBS-induced colitis and led to lower numbers of PU.1 expressing T cells in the lamia propria, suggesting a regulatory role for Th9 cells in the experimental TNBS colitis model. Since IL-9 is known to functionally alter intestinal barrier function in colonic inflammation, we assessed the expression of tight junction molecules in intestinal epithelial cells of TNBS-inflamed mice. Therefore we made real-time PCR analyses for tight junction molecules in the inflamed colon from wild-type and IL-9 KO mice, immunofluorescent stainings and investigated the expression of junctional proteins directly in intestinal epithelial cells of TNBS-inflamed mice by Western blot studies. The results demonstrated that sealing proteins like occludin were up regulated in the colon of inflamed IL-9 KO mice. In contrast, the tight junction protein Claudin1 showed lower expression levels when IL-9 is absent. Surprisingly, the pore-forming molecule Claudin2 revealed equal expression in TNBS-treated wild-type and IL-9-deficient animals. These results illustrate the pleiotropic functions of IL-9 in changing intestinal permeability in experimental colitis. Thus, modulation of IL-9 function emerges as a new approach for regulating barrier function in intestinal inflammation. PMID:25838986

  17. Versatile utilization of real-time intraoperative contrast-enhanced ultrasound in cranial neurosurgery: technical note and retrospective case series

    PubMed Central

    Lekht, Ilya; Brauner, Noah; Bakhsheshian, Joshua; Chang, Ki-Eun; Gulati, Mittul; Shiroishi, Mark S.; Grant, Edward G.; Christian, Eisha; Zada, Gabriel

    2016-01-01

    OBJECTIVE Intraoperative contrast-enhanced ultrasound (iCEUS) offers dynamic imaging and provides functional data in real time. However, no standardized protocols or validated quantitative data exist to guide its routine use in neurosurgery. The authors aimed to provide further clinical data on the versatile application of iCEUS through a technical note and illustrative case series. METHODS Five patients undergoing craniotomies for suspected tumors were included. iCEUS was performed using a contrast agent composed of lipid shell microspheres enclosing perflutren (octafluoropropane) gas. Perfusion data were acquired through a time-intensity curve analysis protocol obtained using iCEUS prior to biopsy and/or resection of all lesions. RESULTS Three primary tumors (gemistocytic astrocytoma, glioblastoma multiforme, and meningioma), 1 metastatic lesion (melanoma), and 1 tumefactive demyelinating lesion (multiple sclerosis) were assessed using real-time iCEUS. No intraoperative complications occurred following multiple administrations of contrast agent in all cases. In all neoplastic cases, iCEUS replicated enhancement patterns observed on preoperative Gd-enhanced MRI, facilitated safe tumor de-bulking by differentiating neoplastic tissue from normal brain parenchyma, and helped identify arterial feeders and draining veins in and around the surgical cavity. Intraoperative CEUS was also useful in guiding a successful intraoperative needle biopsy of a cerebellar tumefactive demyelinating lesion obtained during real-time perfusion analysis. CONCLUSIONS Intraoperative CEUS has potential for safe, real-time, dynamic contrast-based imaging for routine use in neurooncological surgery and image-guided biopsy. Intraoperative CEUS eliminates the effect of anatomical distortions associated with standard neuronavigation and provides quantitative perfusion data in real time, which may hold major implications for intraoperative diagnosis, tissue differentiation, and quantification of

  18. Early prediction of functional recovery after experimental stroke: functional magnetic resonance imaging, electrophysiology, and behavioral testing in rats.

    PubMed

    Weber, Ralph; Ramos-Cabrer, Pedro; Justicia, Carlos; Wiedermann, Dirk; Strecker, Cordula; Sprenger, Christiane; Hoehn, Mathias

    2008-01-30

    Therapeutic success of treatment of cerebral diseases must be assessed in terms of functional outcome. In experimental stroke studies, this has been limited to behavioral studies combined with morphological evaluations and single time point functional magnetic resonance imaging (fMRI) measurements but lacking the access to understanding underlying mechanisms for alterations in brain activation. Using a recently developed blood oxygenation level-dependent fMRI protocol to study longitudinal and intraindividual profiles of functional brain activation in the somatosensory system, we have demonstrated activation reemergence in the original representation field as the basic principle of functional recovery from experimental stroke. No plastic reorganization has been observed at any time point during 7 weeks after stroke induction. Applying combined recording of fMRI and somatosensory evoked potentials, we observed a tight coupling of electrical brain activity and hemodynamic response at all times, indicating persistent preservation of neurovascular coupling. Identification of functional brain recovery mechanisms has important implications for the understanding of brain plasticity after cerebral lesions, whereas preservation of neurovascular coupling is important for the clinical translation of fMRI.

  19. Fibronectin adsorption on functionalized electrospun polycaprolactone scaffolds: experimental and molecular dynamics studies.

    PubMed

    Regis, Shawn; Youssefian, Sina; Jassal, Manisha; Phaneuf, Matthew D; Rahbar, Nima; Bhowmick, Sankha

    2014-06-01

    Designing scaffolds to modulate protein adsorption is a key to building advanced scaffolds for tissue regeneration. Protein adsorption to tissue engineering scaffolds is critical in early cell attachment, survival, and eventual proliferation. The goal of this study is to examine the effect of functionalization on fibronectin adsorption to electrospun polycaprolactone (PCL) scaffolds through experimentation using fluorescently labeled fibronectin and to couple this experimental data with analysis of interaction energies obtained through molecular dynamics (MD) simulations to develop a better understanding of the adsorption process. This study is the first to analyze and compare experimental and MD simulation results of fibronectin adsorption on functionalized electrospun PCL scaffolds. Electrospun nanofiber PCL scaffolds were treated with either 1 N NaOH (hydrolyzed) or 46% hexamethylenediamine (HMD) (aminated) solution to be compared with untreated (control) scaffolds. We found that aminated PCL scaffolds experimentally adsorbed more fibronectin than control scaffolds, whereas hydrolyzed scaffolds showed decreased adsorption. MD simulations carried out with NVT ensemble at a temperature of 310 K indicated a higher work of adhesion for both functionalized scaffolds over control. Also, the simulations revealed different conformations of fibronectin on each scaffold type after adsorption, with the arginine-glycine-aspartic acid sequence appearing most accessible on the aminated scaffolds. This suggests that functionalization affects not only the quantity of protein that will adsorb on a scaffold but how it attaches as well, which could affect subsequent cell attachment.

  20. Experimental demonstration of linear precompensation of a nonlinear transfer function due to second-harmonic generation.

    PubMed

    Vidal, Sébastien; Luce, Jacques; Penninckx, Denis

    2011-01-01

    We report on what we believe is the first experimental demonstration of the linear precompensation of a nonlinear transfer function due to frequency conversion. As a proof of principle, we show the effective precompensation with an interferometric filter of FM-to-AM conversion due to second-harmonic generation in a potassium titanyl phosphate crystal.

  1. Roots of neuroanatomy, neurology, and neurosurgery as found in the Bible and Talmud.

    PubMed

    Tubbs, R Shane; Loukas, Marios; Shoja, Mohammadali M; Cohen-Gadol, Aaron A; Wellons, John C; Oakes, W Jerry

    2008-07-01

    Historical observations and interpretations regarding the treatment of components of the nervous system can be found in the writings of the Bible and Talmud. A review of topics germane to modern neuroanatomy, neurology, and neurosurgery from these early, rich writings is presented herein. These historic writings provide a glimpse into the early understanding, description, and treatment of pathologies of the nervous system.

  2. Fedor Krause: the first systematic use of X-rays in neurosurgery.

    PubMed

    Elhadi, Ali M; Kalb, Samuel; Martirosyan, Nikolay L; Agrawal, Abhishek; Preul, Mark C

    2012-08-01

    Within a few months of Wilhelm Conrad Röntgen's discovery of x-rays in 1895, Fedor Krause acquired an x-ray apparatus and began to use it in his daily interactions with patients and for diagnosis. He was the first neurosurgeon to use x-rays methodically and systematically. In 1908 Krause published the first volume of text on neurosurgery, Chirurgie des Gehirns und Rückenmarks (Surgery of the Brain and Spinal Cord), which was translated into English in 1909. The second volume followed in 1911. This was the first published multivolume text totally devoted to neurosurgery. Although Krause excelled in and promoted neurosurgery, he believed that surgeons should excel at general surgery. Importantly, Krause was inclined to adopt technology that he believed could be helpful in surgery. His 1908 text was the first neurosurgical text to contain a specific chapter on x-rays ("Radiographie") that showed roentgenograms of neurosurgical procedures and pathology. After the revolutionary discovery of x-rays by Röntgen, many prominent neurosurgeons seemed pessimistic about the use of x-rays for anything more than trauma or fractures. Krause immediately seized on its use to guide and monitor ventricular drainage and especially for the diagnosis of tumors of the skull base. The x-ray images contained in Krause's "Radiographie" chapter provide a seminal view into the adoption of new technology and the development of neurosurgical technique and are part of neurosurgery's heritage.

  3. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Self-retaining retractor for neurosurgery. 882.4800 Section 882.4800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4800...

  4. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Self-retaining retractor for neurosurgery. 882.4800 Section 882.4800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4800...

  5. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Self-retaining retractor for neurosurgery. 882.4800 Section 882.4800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4800...

  6. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Self-retaining retractor for neurosurgery. 882.4800 Section 882.4800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4800...

  7. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Self-retaining retractor for neurosurgery. 882.4800 Section 882.4800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4800...

  8. History of the Department of Neurosurgery at Thomas Jefferson University Hospital.

    PubMed

    Chalouhi, Nohra; Osterholm, Jewell; Jabbour, Pascal; Dumont, Aaron S; Gonzalez, L Fernando; Harrop, James; Sharan, Ashwini; Rosenwasser, Robert; Tjoumakaris, Stavropoula

    2013-10-01

    The neurosurgical tradition at Jefferson Medical College began in the 19th century with Samuel Gross. In his textbook entitled A System of Surgery, Gross revealed his knowledge of the disorders of the nervous system at a time when innovations were practically inexistent. Gross' work paved the way for William Williams Keen, "America's first brain surgeon." In 1887, Keen became the first surgeon in the nation to successfully remove a primary brain tumor. In 1893, Keen operated secretly on President Grover Cleveland for removal of an intraoral sarcoma and later served as a consultant to Franklin Roosevelt after he contracted poliomyelitis. The neurosurgery division was established in 1943 by J. Rudolph Jaeger. It was Philip Gordy who created a distinct Department of Neurosurgery in 1969. Jewell L. Osterholm became chairman of the Department of Neurosurgery in 1974. Since 2004, Robert Rosenwasser has served as chairman, and the Department of Neurosurgery at Jefferson has grown to include 26 faculty members. The residency has expanded to include 3 residents per academic year since 2007.

  9. Current applications and future perspectives of robotics in cerebrovascular and endovascular neurosurgery.

    PubMed

    Menaker, Simon A; Shah, Sumedh S; Snelling, Brian M; Sur, Samir; Starke, Robert M; Peterson, Eric C

    2017-08-18

    Advances in robotic medicine have been adopted by various surgical subspecialties as the benefits of this technology become more readily apparent: precision in narrow operative windows, tremor controlled movements, and modestly improved outcomes, among others. Vascular neurosurgery, in particular, remains open to newer and more cutting edge treatment options for complex pathologies, and robotics may be on the horizon for such advances. We seek to provide a broad overview of these innovations in vascular neurosurgery for both practitioners well acquainted with robotics and those seeking to become more familiar. Technologies under development for cerebrovascular and endovascular neurosurgery include robot assisted angiography, guided operative microscopes, coil insertion systems, and endoscopic clipping devices. Additionally, robotic systems in the fields of interventional cardiology and radiology have potential applications to endovascular neurosurgery but require proper modifications to navigate complex intracerebral vasculature. Robotic technology is not without drawbacks, as broad implementation may lead to increased cost, training time, and potential delays in emergency situations. Further cultivation of current multidisciplinary technologies and investment into newer systems is necessary before robotics can make a sizable impact in clinical practice. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Experiential Learning of Robotics Fundamentals Based on a Case Study of Robot-Assisted Stereotactic Neurosurgery

    ERIC Educational Resources Information Center

    Faria, Carlos; Vale, Carolina; Machado, Toni; Erlhagen, Wolfram; Rito, Manuel; Monteiro, Sérgio; Bicho, Estela

    2016-01-01

    Robotics has been playing an important role in modern surgery, especially in procedures that require extreme precision, such as neurosurgery. This paper addresses the challenge of teaching robotics to undergraduate engineering students, through an experiential learning project of robotics fundamentals based on a case study of robot-assisted…

  11. Preliminary Results on the Experimental Investigation of the Structure Functions of Bound Nucleons

    SciTech Connect

    Bodek, Arie

    2016-08-01

    We present preliminary results on an experimental study of the nuclear modification of the longitudinal ($\\sigma_L$) and transverse ($\\sigma_T$) structure functions of nucleons bound in nuclear targets. The origin of these modifications (commonly referred as as the EMC effect) is not fully understood. Our measurements of R= $\\sigma_L / \\sigma_T$ for nuclei ($R_A$) and for deuterium ($R_D$) indicate that nuclear modifications of the structure functions of bound nucleons are different for the longitudinal and transverse structure functions, and that contrary to expectation from several theoretical models, $R_A< R_D$.

  12. A Monte Carlo investigation of experimental data requirements for fitting polynomial functions

    NASA Technical Reports Server (NTRS)

    Canavos, G. C.

    1974-01-01

    This report examines the extent to which sample size affects the accuracy of a low order polynomial approximation of an experimentally observed quantity and establishes a trend toward improvement in the accuracy of the approximation as a function of sample size. The task is made possible through a simulated analysis carried out by the Monte Carlo method, in which data are generated by using several transcendental or algebraic functions as models. Contaminated data of varying amounts are fitted to linear quadratic or cubic polynomials, and the behavior of the mean-squared error of the residual variance is determined as a function of sample size. Results indicate that the effect of the size of the sample is significant only for relatively small sample sizes and diminishes drastically for moderate and large amounts of experimental data.

  13. Developing a new model for the invention and translation of neurotechnologies in academic neurosurgery.

    PubMed

    Leuthardt, Eric C

    2013-01-01

    There is currently an acceleration of new scientific and technical capabilities that create new opportunities for academic neurosurgery. To engage these changing dynamics, the Center for Innovation in Neuroscience and Technology (CINT) was created on the premise that successful innovation of device-related ideas relies on collaboration between multiple disciplines. The CINT has created a unique model that integrates scientific, medical, engineering, and legal/business experts to participate in the continuum from idea generation to translation. To detail the method by which this model has been implemented in the Department of Neurological Surgery at Washington University in St. Louis and the experience that has been accrued thus far. The workflow is structured to enable cross-disciplinary interaction, both intramurally and extramurally between academia and industry. This involves a structured method for generating, evaluating, and prototyping promising device concepts. The process begins with the "invention session," which consists of a structured exchange between inventors from diverse technical and medical backgrounds. Successful ideas, which pass a separate triage mechanism, are then sent to industry-sponsored multidisciplinary fellowships to create functioning prototypes. After 3 years, the CINT has engaged 32 clinical and nonclinical inventors, resulting in 47 ideas, 16 fellowships, and 12 patents, for which 7 have been licensed to industry. Financial models project that if commercially successful, device sales could have a notable impact on departmental revenue. The CINT is a model that supports an integrated approach from the time an idea is created through its translational development. To date, the approach has been successful in creating numerous concepts that have led to industry licenses. In the long term, this model will create a novel revenue stream to support the academic neurosurgical mission.

  14. Automatic deformable MR-ultrasound registration for image-guided neurosurgery.

    PubMed

    Rivaz, Hassan; Chen, Sean Jy-Shyang; Collins, D Louis

    2015-02-01

    In this work, we present a novel algorithm for registration of 3-D volumetric ultrasound (US) and MR using Robust PaTch-based cOrrelation Ratio (RaPTOR). RaPTOR computes local correlation ratio (CR) values on small patches and adds the CR values to form a global cost function. It is therefore invariant to large amounts of spatial intensity inhomogeneity. We also propose a novel outlier suppression technique based on the orientations of the RaPTOR gradients. Our deformation is modeled with free-form cubic B-splines. We analytically derive the derivatives of RaPTOR with respect to the transformation, i.e., the displacement of the B-spline nodes, and optimize RaPTOR using a stochastic gradient descent approach. RaPTOR is validated on MR and tracked US images of neurosurgery. Deformable registration of the US and MR images acquired, respectively, preoperation and postresection is of significant clinical significance, but challenging due to, among others, the large amount of missing correspondences between the two images. This work is also novel in that it performs automatic registration of this challenging dataset. To validate the results, we manually locate corresponding anatomical landmarks in the US and MR images of tumor resection in brain surgery. Compared to rigid registration based on the tracking system alone, RaPTOR reduces the mean initial mTRE over 13 patients from 5.9 to 2.9 mm, and the maximum initial TRE from 17.0 to 5.9 mm. Each volumetric registration using RaPTOR takes about 30 sec on a single CPU core. An important challenge in the field of medical image analysis is the shortage of publicly available dataset, which can both facilitate the advancement of new algorithms to clinical settings and provide a benchmark for comparison. To address this problem, we will make our manually located landmarks available online.

  15. New technologies in neurosurgery: Effects on the conventional techniques and anaesthesiological considerations

    NASA Astrophysics Data System (ADS)

    Fasano, V. A.; Lombard, G. F.; Urciuoli, R.; Benech, F.; Ponzio, R. M.

    1985-09-01

    New technologies have been recently introduced into neurosurgery: laser sources, ultrasonic aspiration, intraoperative echotomography and intraoperative Doppler flowmeter. The aim of this work, showing the use of these instruments in different neurosurgical operations, is to discuss the effective improvements of the surgical techniques when comparing new and traditional technologies. The laser is able to concentrate high energies in restricted areas allowing a maximum selectivity. Having a superficial destructive effect with associated hemostasis, CO 2 and argon are suitable in dissection maneuvers. Nd:YAG produces a high thermal diffusion, consenting a deeper and extended tissue removal and a considerable reduction of intraoperative blood loss also in vascularized tumors. A promising field of application of the laser is the treatment of cerebral vascular malformations. In arterio-venous malformations the irradiation of the nidus with Nd:YAG produces a rapid obliteration of the pathologic vessels. This technique avoids the isolation of the feeding arteries and reduces the manipulation of the surrounding tissue. In small saccular aneurysms an argon laser is used to produce a shrinkage of the dilatation with consequent occlusion of the malformation. The ultrasonic aspirator is used in the tumoral surgery to obtain a more rapid demolition of the mass by fragmentation and suction. Intraoperative echotomography consents a sharp topographic localization of the lesion, particularly in deeper cerebral areas, providing data on the nature of solid tumors. The intraoperative Doppler flowmeter is useful for identification of the feeding arteries and the shunt of the small deep-seated arterio-venous malformations consenting a dynamic evaluation of the operation. General anaesthesia in neurosurgical procedures is favourably influenced by laser use. Conventional anaesthetic techniques, however, must be modified to avoid the harmful effect of the laser, depending on the movements

  16. Reproducibility and Variability of the Cost Functions Reconstructed from Experimental Recordings in Multi-Finger Prehension

    PubMed Central

    Niu, Xun; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2012-01-01

    The main goal of the study is to examine whether the cost (objective) functions reconstructed from experimental recordings in multi-finger prehension tasks are reproducible over time, i.e., whether the functions reflect stable preferences of the subjects and can be considered personal characteristics of motor coordination. Young, healthy participants grasped an instrumented handle with varied values of external torque, load and target grasping force and repeated the trials on three days: Day 1, Day 2, and Day 7. By following Analytical Inverse Optimization (ANIO) computation procedures, the cost functions for individual subjects were reconstructed from the experimental recordings (individual finger forces) for each day. The cost functions represented second-order polynomials of finger forces with non-zero linear terms. To check whether the obtained cost functions were reproducible over time a cross-validation was performed: a cost function obtained on Day i was applied to experimental data observed on Day j (i≠j). In spite of the observed day-to-day variability of the performance and the cost functions, the ANIO reconstructed cost functions were found to be reproducible over time: application of a cost function Ci to the data of Day j (i≠j) resulted in smaller deviations from the experimental observations than using other commonly used cost functions. Other findings are: (a) The 2nd order coefficients Ki of the cost function showed negative linear relations with finger force magnitudes. This fact may be interpreted as encouraging involvement of stronger fingers in tasks requiring higher total force magnitude production. (b) The finger forces were distributed on a 2-dimensional plane in the 4-dimensional finger force space, which has been confirmed for all subjects and all testing sessions. (c) The discovered principal components in the principal component analysis of the finger forces agreed well with the principle of superposition, i.e. the complex action of

  17. Oro-facial functions in experimental models of cerebral palsy: a systematic review.

    PubMed

    Lacerda, D C; Ferraz-Pereira, K N; Bezerra de Morais, A T; Costa-de-Santana, B J R; Quevedo, O G; Manhães-de-Castro, R; Toscano, A E

    2017-04-01

    Children who suffer from cerebral palsy (CP) often present comorbidities in the form of oro-facial dysfunctions. Studies in animals have contributed to elaborate potential therapies aimed at minimising the chronic disability of the syndrome. To systematically review the scientific literature regarding the possible effects that experimental models of CP can have on oro-facial functions. Two independent authors conducted a systematic review in the electronic databases Medline, Scopus, CINAHL, Web of Science and Lilacs, using Mesh and Decs terms in animal models. The motor and sensory parameters of sucking, chewing and swallowing were considered as primary outcomes; reactivity odour, controlled salivation, postural control, head mobility during feeding and the animal's ability to acquire food were secondary outcomes. Ten studies were included in the present review. Most studies used rabbits as experimental models of CP, which was induced by either hypoxia-ischemia, inflammation or intraventricular haemorrhage. Oro-facial functions were altered in all experimental models of CP. However, we found more modifications in hypoxia-ischemia models overall. On the other hand, the model of inflammation was more effective to reproduce higher damage for coordinating sucking and swallowing. All of the CP experimental models that were assessed modified the oral functions in different animal species. However, further studies should be conducted in order to clarify the mechanisms underlying oro-facial damage in order to optimise treatment strategies for children who suffer from CP.

  18. Integration of patient specific modeling and advanced image processing techniques for image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

    Archip, Neculai; Fedorov, Andriy; Lloyd, Bryn; Chrisochoides, Nikos; Golby, Alexandra; Black, Peter M.; Warfield, Simon K.

    2006-03-01

    A major challenge in neurosurgery oncology is to achieve maximal tumor removal while avoiding postoperative neurological deficits. Therefore, estimation of the brain deformation during the image guided tumor resection process is necessary. While anatomic MRI is highly sensitive for intracranial pathology, its specificity is limited. Different pathologies may have a very similar appearance on anatomic MRI. Moreover, since fMRI and diffusion tensor imaging are not currently available during the surgery, non-rigid registration of preoperative MR with intra-operative MR is necessary. This article presents a translational research effort that aims to integrate a number of state-of-the-art technologies for MRI-guided neurosurgery at the Brigham and Women's Hospital (BWH). Our ultimate goal is to routinely provide the neurosurgeons with accurate information about brain deformation during the surgery. The current system is tested during the weekly neurosurgeries in the open magnet at the BWH. The preoperative data is processed, prior to the surgery, while both rigid and non-rigid registration algorithms are run in the vicinity of the operating room. The system is tested on 9 image datasets from 3 neurosurgery cases. A method based on edge detection is used to quantitatively validate the results. 95% Hausdorff distance between points of the edges is used to estimate the accuracy of the registration. Overall, the minimum error is 1.4 mm, the mean error 2.23 mm, and the maximum error 3.1 mm. The mean ratio between brain deformation estimation and rigid alignment is 2.07. It demonstrates that our results can be 2.07 times more precise then the current technology. The major contribution of the presented work is the rigid and non-rigid alignment of the pre-operative fMRI with intra-operative 0.5T MRI achieved during the neurosurgery.

  19. Virtual reality training in neurosurgery: Review of current status and future applications.

    PubMed

    Alaraj, Ali; Lemole, Michael G; Finkle, Joshua H; Yudkowsky, Rachel; Wallace, Adam; Luciano, Cristian; Banerjee, P Pat; Rizzi, Silvio H; Charbel, Fady T

    2011-01-01

    Over years, surgical training is changing and years of tradition are being challenged by legal and ethical concerns for patient safety, work hour restrictions, and the cost of operating room time. Surgical simulation and skill training offer an opportunity to teach and practice advanced techniques before attempting them on patients. Simulation training can be as straightforward as using real instruments and video equipment to manipulate simulated "tissue" in a box trainer. More advanced virtual reality (VR) simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. A PubMed review of the literature was performed for the MESH words "Virtual reality, "Augmented Reality", "Simulation", "Training", and "Neurosurgery". Relevant articles were retrieved and reviewed. A review of the literature was performed for the history, current status of VR simulation in neurosurgery. Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and credential surgeons as technically competent. The number of published literature discussing the application of VR simulation in neurosurgery training has evolved over the last decade from data visualization, including stereoscopic evaluation to more complex augmented reality models. With the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Recent studies have shown the coloration of proficiency with those simulators and levels of experience in the real world. Fully immersive technology is starting to be applied to the practice of neurosurgery. In the near future, detailed VR neurosurgical modules

  20. Leveraging enzyme structure-function relationships for functional inference and experimental design: the structure-function linkage database.

    PubMed

    Pegg, Scott C-H; Brown, Shoshana D; Ojha, Sunil; Seffernick, Jennifer; Meng, Elaine C; Morris, John H; Chang, Patricia J; Huang, Conrad C; Ferrin, Thomas E; Babbitt, Patricia C

    2006-02-28

    The study of mechanistically diverse enzyme superfamilies-collections of enzymes that perform different overall reactions but share both a common fold and a distinct mechanistic step performed by key conserved residues-helps elucidate the structure-function relationships of enzymes. We have developed a resource, the structure-function linkage database (SFLD), to analyze these structure-function relationships. Unique to the SFLD is its hierarchical classification scheme based on linking the specific partial reactions (or other chemical capabilities) that are conserved at the superfamily, subgroup, and family levels with the conserved structural elements that mediate them. We present the results of analyses using the SFLD in correcting misannotations, guiding protein engineering experiments, and elucidating the function of recently solved enzyme structures from the structural genomics initiative. The SFLD is freely accessible at http://sfld.rbvi.ucsf.edu.

  1. Experimental approaches for addressing fundamental biological questions in living, functioning cells with single molecule precision.

    PubMed

    Lenn, Tchern; Leake, Mark C

    2012-06-01

    In recent years, single molecule experimentation has allowed researchers to observe biological processes at the sensitivity level of single molecules in actual functioning, living cells, thereby allowing us to observe the molecular basis of the key mechanistic processes in question in a very direct way, rather than inferring these from ensemble average data gained from traditional molecular and biochemical techniques. In this short review, we demonstrate the impact that the application of single molecule bioscience experimentation has had on our understanding of various cellular systems and processes, and the potential that this approach has for the future to really address very challenging and fundamental questions in the life sciences.

  2. Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

    PubMed Central

    van de Streek, Jacco; Neumann, Marcus A.

    2010-01-01

    This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 Å either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect. PMID:20841921

  3. Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations.

    PubMed

    van de Streek, Jacco; Neumann, Marcus A

    2010-10-01

    This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 A either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.

  4. Reconstruction of the unknown optimization cost functions from experimental recordings during static multi-finger prehension

    PubMed Central

    Niu, Xun; Terekhov, Alexander V.; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2013-01-01

    The goal of the research is to reconstruct the unknown cost (objective) function(s) presumably used by the neural controller for sharing the total force among individual fingers in multi-finger prehension. The cost function was determined from experimental data by applying the recently developed Analytical Inverse Optimization (ANIO) method (Terekhov et al 2010). The core of the ANIO method is the Theorem of Uniqueness that specifies conditions for unique (with some restrictions) estimation of the objective functions. In the experiment, subjects (n=8) grasped an instrumented handle and maintained it at rest in the air with various external torques, loads, and target grasping forces applied to the object. The experimental data recorded from 80 trials showed a tendency to lie on a 2-dimensional hyperplane in the 4-dimensional finger-force space. Because the constraints in each trial were different, such a propensity is a manifestation of a neural mechanism (not the task mechanics). In agreement with the Lagrange principle for the inverse optimization, the plane of experimental observations was close to the plane resulting from the direct optimization. The latter plane was determined using the ANIO method. The unknown cost function was reconstructed successfully for each performer, as well as for the group data. The cost functions were found to be quadratic with non-zero linear terms. The cost functions obtained with the ANIO method yielded more accurate results than other optimization methods. The ANIO method has an evident potential for addressing the problem of optimization in motor control. PMID:22104742

  5. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for liquid mixtures

    SciTech Connect

    Ploetz, Elizabeth A.; Smith, Paul E.

    2015-03-07

    Kirkwood-Buff or Fluctuation Solution Theory can be used to provide experimental pair fluctuations, and/or integrals over the pair distribution functions, from experimental thermodynamic data on liquid mixtures. Here, this type of approach is used to provide triplet and quadruplet fluctuations, and the corresponding integrals over the triplet and quadruplet distribution functions, in a purely thermodynamic manner that avoids the use of structure factors. The approach is then applied to binary mixtures of water + methanol and benzene + methanol over the full composition range under ambient conditions. The observed correlations between the different species vary significantly with composition. The magnitude of the fluctuations and integrals appears to increase as the number of the most polar molecule involved in the fluctuation or integral also increases. A simple physical picture of the fluctuations is provided to help rationalize some of these variations.

  6. Experimental Approaches for Defining Functional Roles of Microbes in the Human Gut

    PubMed Central

    Dantas, Gautam; Sommer, Morten O.A.; Degnan, Patrick H.; Goodman, Andrew L.

    2016-01-01

    The complex and intimate relationship between humans and their gut microbial communities is becoming less obscure, due in part to large-scale gut microbial genome-sequencing projects and culture-independent surveys of the composition and gene content of these communities. These studies build upon, and are complemented by, experimental efforts to define underlying mechanisms of host-microbe interactions in simplified model systems. This review highlights the intersection of these approaches. Experimental studies now leverage the advances in high-throughput DNA sequencing that have driven the explosion of microbial genome and community profiling projects, and the loss-of-function and gain-of-function strategies long employed in model organisms are now being extended to microbial genes, species, and communities from the human gut. These developments promise to deepen our understanding of human gut host–microbiota relationships and are readily applicable to other host-associated and free-living microbial communities. PMID:24024637

  7. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for liquid mixtures

    PubMed Central

    2015-01-01

    Kirkwood-Buff or Fluctuation Solution Theory can be used to provide experimental pair fluctuations, and/or integrals over the pair distribution functions, from experimental thermodynamic data on liquid mixtures. Here, this type of approach is used to provide triplet and quadruplet fluctuations, and the corresponding integrals over the triplet and quadruplet distribution functions, in a purely thermodynamic manner that avoids the use of structure factors. The approach is then applied to binary mixtures of water + methanol and benzene + methanol over the full composition range under ambient conditions. The observed correlations between the different species vary significantly with composition. The magnitude of the fluctuations and integrals appears to increase as the number of the most polar molecule involved in the fluctuation or integral also increases. A simple physical picture of the fluctuations is provided to help rationalize some of these variations. PMID:25747091

  8. Experimental demonstration of programmable multi-functional spin logic cell based on spin Hall effect

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Wan, C. H.; Yuan, Z. H.; Fang, C.; Kong, W. J.; Wu, H.; Zhang, Q. T.; Tao, B. S.; Han, X. F.

    2017-04-01

    Confronting with the gigantic volume of data produced every day, raising integration density by reducing the size of devices becomes harder and harder to meet the ever-increasing demand for high-performance computers. One feasible path is to actualize more logic functions in one cell. In this respect, we experimentally demonstrate a prototype spin-orbit torque based spin logic cell integrated with five frequently used logic functions (AND, OR, NOT, NAND and NOR). The cell can be easily programmed and reprogrammed to perform desired function. Furthermore, the information stored in cells is symmetry-protected, making it possible to expand into logic gate array where the cell can be manipulated one by one without changing the information of other undesired cells. This work provides a prospective example of multi-functional spin logic cell with reprogrammability and nonvolatility, which will advance the application of spin logic devices.

  9. Validation of MCDS by comparison of predicted with experimental velocity distribution functions in rarefied normal shocks

    NASA Technical Reports Server (NTRS)

    Pham-Van-diep, Gerald C.; Erwin, Daniel A.

    1989-01-01

    Velocity distribution functions in normal shock waves in argon and helium are calculated using Monte Carlo direct simulation. These are compared with experimental results for argon at M = 7.18 and for helium at M = 1.59 and 20. For both argon and helium, the variable-hard-sphere (VHS) model is used for the elastic scattering cross section, with the velocity dependence derived from a viscosity-temperature power-law relationship in the way normally used by Bird (1976).

  10. Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

    NASA Astrophysics Data System (ADS)

    Sison Escaño, Mary Clare; Lacdao Arevalo, Ryan; Gyenge, Elod; Kasai, Hideaki

    2014-09-01

    The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH4- on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements.

  11. A value-based, no-cost-to-patient health model in the developing world: Critical appraisal of a unique patient-centric neurosurgery unit

    PubMed Central

    Thakar, Sumit; Dadlani, Ravi; Sivaraju, Laxminadh; Aryan, Saritha; Mohan, Dilip; Sai Kiran, Narayanam Anantha; Rajarathnam, Ravikiran; Shyam, Maya; Sadanand, Venkatraman; Hegde, Alangar S.

    2015-01-01

    Background: It is well-accepted that the current healthcare scenario worldwide is due for a radical change, given that it is fraught with mounting costs and varying quality. Various modifications in health policies have been instituted toward this end. An alternative model, the low-cost, value-based health model, focuses on maximizing value for patients by moving away from a physician-centered, supply-driven system to a patient-centered system. Methods: The authors discuss the successful inception, functioning, sustainability, and replicability of a novel health model in neurosurgery built and sustained by inspired humanitarianism and that provides all treatment at no cost to the patients irrespective of their socioeconomic strata, color or creed. Results: The Sri Sathya Sai Institute of Higher Medical Sciences (SSSIHMS) at Whitefield, Bengaluru, India, a private charitable hospital established in 2001, functions on the ideals of providing free state-of-the-art healthcare to all in a compassionate and holistic manner. With modern equipment and respectable outcome benchmarks, its neurosurgery unit has operated on around 18,000 patients since its inception, and as such, has contributed INR 5310 million (USD 88.5 million) to society from an economic standpoint. Conclusions: The inception and sustainability of the SSSIHMS model are based on self-perpetuating philanthropy, a cost-conscious culture and the dissemination of human values. Replicated worldwide, at least in the developing nations, this unique healthcare model may well change the face of healthcare economics. PMID:26322241

  12. Downregulation of FoxC2 Increased Susceptibility to Experimental Colitis: Influence of Lymphatic Drainage Function?

    PubMed Central

    Becker, Felix; Potepalov, Sergey; Shehzahdi, Romana; Bernas, Michael; Witte, Marlys; Abreo, Fleurette; Traylor, James; Orr, Wayne A.; Tsunoda, Ikuo

    2015-01-01

    Background: Although inflammation-induced expansion of the intestinal lymphatic vasculature (lymphangiogenesis) is known to be a crucial event in limiting inflammatory processes, through clearance of interstitial fluid and immune cells, considerably less is known about the impact of an impaired lymphatic clearance function (as seen in inflammatory bowel diseases) on this cascade. We aimed to investigate whether the impaired intestinal lymphatic drainage function observed in FoxC2(+/−) mice would influence the course of disease in a model of experimental colitis. Methods: Acute dextran sodium sulfate colitis was induced in wild-type and haploinsufficient FoxC2(+/−) mice, and survival, disease activity, colonic histopathological injury, neutrophil, T-cell, and macrophage infiltration were evaluated. Functional and structural changes in the intestinal lymphatic vessel network were analyzed, including submucosal edema, vessel morphology, and lymphatic vessel density. Results: We found that FoxC2 downregulation in FoxC2(+/−) mice significantly increased the severity and susceptibility to experimental colitis, as displayed by lower survival rates, increased disease activity, greater histopathological injury, and elevated colonic neutrophil, T-cell, and macrophage infiltration. These findings were accompanied by structural (dilated torturous lymphatic vessels) and functional (greater submucosal edema, higher immune cell burden) changes in the intestinal lymphatic vasculature. Conclusions: These results indicate that sufficient lymphatic clearance plays a crucial role in limiting the initiation and perpetuation of experimental colitis and those disturbances in the integrity of the intestinal lymphatic vessel network could intensify intestinal inflammation. Future therapies might be able to exploit these processes to restore and maintain adequate lymphatic clearance function in inflammatory bowel disease. PMID:25822012

  13. Functional Inference of Complex Anatomical Tendinous Networks at a Macroscopic Scale via Sparse Experimentation

    PubMed Central

    Saxena, Anupam; Lipson, Hod; Valero-Cuevas, Francisco J.

    2012-01-01

    In systems and computational biology, much effort is devoted to functional identification of systems and networks at the molecular-or cellular scale. However, similarly important networks exist at anatomical scales such as the tendon network of human fingers: the complex array of collagen fibers that transmits and distributes muscle forces to finger joints. This network is critical to the versatility of the human hand, and its function has been debated since at least the 16th century. Here, we experimentally infer the structure (both topology and parameter values) of this network through sparse interrogation with force inputs. A population of models representing this structure co-evolves in simulation with a population of informative future force inputs via the predator-prey estimation-exploration algorithm. Model fitness depends on their ability to explain experimental data, while the fitness of future force inputs depends on causing maximal functional discrepancy among current models. We validate our approach by inferring two known synthetic Latex networks, and one anatomical tendon network harvested from a cadaver's middle finger. We find that functionally similar but structurally diverse models can exist within a narrow range of the training set and cross-validation errors. For the Latex networks, models with low training set error [<4%] and resembling the known network have the smallest cross-validation errors [∼5%]. The low training set [<4%] and cross validation [<7.2%] errors for models for the cadaveric specimen demonstrate what, to our knowledge, is the first experimental inference of the functional structure of complex anatomical networks. This work expands current bioinformatics inference approaches by demonstrating that sparse, yet informative interrogation of biological specimens holds significant computational advantages in accurate and efficient inference over random testing, or assuming model topology and only inferring parameters values. These

  14. The impact of incomplete knowledge on evaluation: an experimental benchmark for protein function prediction

    PubMed Central

    Huttenhower, Curtis; Hibbs, Matthew A.; Myers, Chad L.; Caudy, Amy A.; Hess, David C.; Troyanskaya, Olga G.

    2009-01-01

    Motivation: Rapidly expanding repositories of highly informative genomic data have generated increasing interest in methods for protein function prediction and inference of biological networks. The successful application of supervised machine learning to these tasks requires a gold standard for protein function: a trusted set of correct examples, which can be used to assess performance through cross-validation or other statistical approaches. Since gene annotation is incomplete for even the best studied model organisms, the biological reliability of such evaluations may be called into question. Results: We address this concern by constructing and analyzing an experimentally based gold standard through comprehensive validation of protein function predictions for mitochondrion biogenesis in Saccharomyces cerevisiae. Specifically, we determine that (i) current machine learning approaches are able to generalize and predict novel biology from an incomplete gold standard and (ii) incomplete functional annotations adversely affect the evaluation of machine learning performance. While computational approaches performed better than predicted in the face of incomplete data, relative comparison of competing approaches—even those employing the same training data—is problematic with a sparse gold standard. Incomplete knowledge causes individual methods' performances to be differentially underestimated, resulting in misleading performance evaluations. We provide a benchmark gold standard for yeast mitochondria to complement current databases and an analysis of our experimental results in the hopes of mitigating these effects in future comparative evaluations. Availability: The mitochondrial benchmark gold standard, as well as experimental results and additional data, is available at http://function.princeton.edu/mitochondria Contact: ogt@cs.princeton.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19561015

  15. The history of neurosurgery in Memphis: the Semmes-Murphey Clinic and the Department of Neurosurgery at the University of Tennessee College of Medicine.

    PubMed

    Canale, Dee J; Watridge, Clarence B; Fuehrer, Tyler S; Robertson, Jon H

    2010-01-01

    Neurological surgery was defined as a separate surgical specialty by Harvey Cushing and a few other surgeons, most of whom were trained and influenced by Cushing. One of these, Raphael Eustace Semmes, became the first neurosurgeon in Memphis, Tennessee, in 1912. After World War II, Semmes and his first associate, Francis Murphey, incorporated the Semmes-Murphey Clinic, which has been primarily responsible for the growth of the Department of Neurosurgery at the University of Tennessee Health Science Center in Memphis, as well as the development of select neurosurgical subspecialties in Memphis area hospitals.

  16. Pre-residency peer-reviewed publications are associated with neurosurgery resident choice of academic compared to private practice careers.

    PubMed

    McClelland, Shearwood

    2010-03-01

    Factors predictive of neurosurgery resident or applicant choice of an academic career compared to private practice are highly desired and difficult to discern. Neither medical school choice, student induction to faculty membership, age nor gender predict academic versus private practice choice among neurosurgery residents. This study was performed to examine the role of pre-residency peer-reviewed publications (PRP) in post-residency career choice. Over five years (2001-05) the number of PRP prior to onset of residency of 422 graduates from 79 neurosurgery residency programs certified by the Accreditation Council for Graduate Medical Education was retrospectively examined. The number of publications until the end of the calendar year prior to the start of residency was determined using PubMed (www.pubmed.org). This number was then correlated with the choice of an academic or private practice neurosurgery career. A minority of graduates (46.2%) chose academic neurosurgery careers, 32.2% of graduates had at least one PRP at the time of application to neurosurgery residency, with 16.4% having more than one. A total of 41.6% of graduates with no PRP chose academic careers, compared to 53.7% with one PRP, and 58.0% with more than one. With regard to choice of academic career, the difference between no PRP and at least one were statistically significant (p<0.01), but not between one PRP and more than one. Graduates with at least one PRP were 1.34 times more likely to choose an academic career than graduates with no PRP. Therefore, peer-reviewed PRP are strongly associated with resident choice of an academic over private practice neurosurgery career. This information might be useful in predicting the career choices of neurosurgery residents and residency applicants. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Alfvénic oscillations of the electron distribution function: Linear theory and experimental measurements

    SciTech Connect

    Schroeder, J. W. R. Skiff, F.; Howes, G. G.; Kletzing, C. A.; Carter, T. A.; Dorfman, S.

    2015-12-10

    Wave propagation can be an accurate method for determining material properties. High frequency whistler mode waves (0.7 < ω/|Ω{sub ce}| < 1) in an overdense plasma (ω{sub pe} > |Ω{sub ce}|) are damped primarily by Doppler-shifted electron cyclotron resonance. A kinetic description of whistler mode propagation parallel to the background magnetic field shows that damping is proportional to the parallel electron distribution function. This property enables an experimental determination of the parallel electron distribution function using a measurement of whistler mode wave absorption. The whistler mode wave absorption diagnostic uses this technique on UCLA’s Large Plasma Device (LaPD) to measure the distribution of high energy electrons (5 − 10v{sub te}) with 0.1% precision. The accuracy is limited by systematic effects that need to be considered carefully. Ongoing research uses this diagnostic to investigate the effect of inertial Alfvén waves on the electron distribution function. Results presented here verify experimentally the linear effects of inertial Alfvén waves on the reduced electron distribution function, a necessary step before nonlinear physics can be tested. Ongoing experiments with the whistler mode wave absorption diagnostic are making progress toward the first direct detection of electrons nonlinearly accelerated by inertial Alfvén waves, a process believed to play an important role in auroral generation.

  18. Experimental evidence validating the computational inference of functional associations from gene fusion events: a critical survey.

    PubMed

    Promponas, Vasilis J; Ouzounis, Christos A; Iliopoulos, Ioannis

    2014-05-01

    More than a decade ago, a number of methods were proposed for the inference of protein interactions, using whole-genome information from gene clusters, gene fusions and phylogenetic profiles. This structural and evolutionary view of entire genomes has provided a valuable approach for the functional characterization of proteins, especially those without sequence similarity to proteins of known function. Furthermore, this view has raised the real possibility to detect functional associations of genes and their corresponding proteins for any entire genome sequence. Yet, despite these exciting developments, there have been relatively few cases of real use of these methods outside the computational biology field, as reflected from citation analysis. These methods have the potential to be used in high-throughput experimental settings in functional genomics and proteomics to validate results with very high accuracy and good coverage. In this critical survey, we provide a comprehensive overview of 30 most prominent examples of single pairwise protein interaction cases in small-scale studies, where protein interactions have either been detected by gene fusion or yielded additional, corroborating evidence from biochemical observations. Our conclusion is that with the derivation of a validated gold-standard corpus and better data integration with big experiments, gene fusion detection can truly become a valuable tool for large-scale experimental biology.

  19. A Comparison of Experimental Functional Analysis and the Questions about Behavioral Function (QABF) in the Assessment of Challenging Behavior of Individuals with Autism

    ERIC Educational Resources Information Center

    Healy, Olive; Brett, Denise; Leader, Geraldine

    2013-01-01

    We compared two functional behavioral assessment methods: the Questions About Behavioral Function (QABF; a standardized test) and experimental functional analysis (EFA) to identify behavioral functions of aggressive/destructive behavior, self-injurious behavior and stereotypy in 32 people diagnosed with autism. Both assessments found that self…

  20. A Comparison of Experimental Functional Analysis and the Questions about Behavioral Function (QABF) in the Assessment of Challenging Behavior of Individuals with Autism

    ERIC Educational Resources Information Center

    Healy, Olive; Brett, Denise; Leader, Geraldine

    2013-01-01

    We compared two functional behavioral assessment methods: the Questions About Behavioral Function (QABF; a standardized test) and experimental functional analysis (EFA) to identify behavioral functions of aggressive/destructive behavior, self-injurious behavior and stereotypy in 32 people diagnosed with autism. Both assessments found that self…

  1. Preliminary Results on the Experimental Investigation of the Structure Functions of Bound Nucleons

    SciTech Connect

    Bodek, Arie

    2015-09-01

    We present preliminary results on an experimental study of the nuclear modification of the longitudinal (σL) and transverse (σT) structure functions of nucleons bound in nuclear targets. The origin of these modifications (commonly referred as as the EMC effect) is not fully understood. Our measurements of R= σLT for nuclei (RA) and for deuterium (RD) indicate that nuclear modifications of the structure functions of bound nucleons are different for the longitudinal and transverse structure functions, and that contrary to expectation from several theoretical models, RA < RD.

  2. Lipopolysaccharide-induced experimental immune activation does not impair memory functions in humans.

    PubMed

    Grigoleit, Jan-Sebastian; Oberbeck, J Reiner; Lichte, Philipp; Kobbe, Philipp; Wolf, Oliver T; Montag, Thomas; del Rey, Adriana; Gizewski, Elke R; Engler, Harald; Schedlowski, Manfred

    2010-11-01

    Systemic immune activation occurring together with release of peripheral cytokines can affect behavior and the functioning of the central nervous system (CNS). However, it remains unknown whether and to what extent cognitive functions like memory and attention are affected during transient immune activation. We employed a human endotoxemia model and standardized neuropsychological tests to assess the cognitive effects of an experimental inflammation in two groups of 12 healthy young men before and after intravenous injection of lipopolysaccharide (LPS, Escherichia coli, 0.4 ng/kg) or physiological saline. Endotoxin administration caused a profound transient physiological response with elevations in body temperature, number of circulating neutrophils, and increases in plasma cytokine levels [interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α], and concentrations of norepinephrine, ACTH and cortisol. However, these changes in immune and neuroendocrine parameters were not associated with alterations of memory performance, selective attention or executive functions. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. A Novel Method for Curvefitting the Stretched Exponential Function to Experimental Data.

    PubMed

    June, Ronald K; Cunningham, John P; Fyhrie, David P

    2013-12-01

    The stretched exponential function has many applications in modeling numerous types of experimental relaxation data. However, problems arise when using standard algorithms to fit this function: we have observed that different initializations result in distinct fitted parameters. To avoid this problem, we developed a novel algorithm for fitting the stretched exponential model to relaxation data. This method is advantageous both because it requires only a single adjustable parameter and because it does not require initialization in the solution space. We tested this method on simulated data and experimental stress-relaxation data from bone and cartilage and found favorable results compared to a commonly-used Quasi-Newton method. For the simulated data, strong correlations were found between the simulated and fitted parameters suggesting that this method can accurately determine stretched exponential parameters. When this method was tested on experimental data, high quality fits were observed for both bone and cartilage stress-relaxation data that were significantly better than those determined with the Quasi-Newton algorithm.

  4. Effect of N-acetylcysteine on neutrophil functions during experimental acute pancreatitis.

    PubMed

    Atayoğlu, Kemal; Gürleyik, Günay; Demirel, Gülderen; Özkara, Selvinaz

    2017-03-01

    Systemic inflammatory responses and extrapancreatic vital organ impairment are mediated by activated neutrophil functions and products, such as oxygen-derived free radicals, in patients with acute pancreatitis (AP). The present study is an examination of effects of an antioxidant, N-acetylcysteine (NAC), on local and systemic histopathological changes and neutrophil functions during AP. This experimental study was performed on 24 Wistar albino rats equally divided into 3 groups: Group 1 comprised sham laparotomy, Group 2 had AP induced with taurocholate infusion, and Group 3 consisted of AP with NAC treatment. Histopathological features in pancreas, kidney, and lung tissues were examined for local and systemic changes during AP. Neutrophil functions were evaluated using flow cytometry. Serum levels of pancreatic enzymes were elevated, and histopathological parameters showed acinar cell damage and pancreatic tissue necrosis in the 2 groups with AP. Severe histopathological changes were found in pulmonary and renal tissues, and flow cytometry results indicated defective neutrophil functions in the group with AP alone. NAC treatment significantly ameliorated phagocytosis, chemotaxis, and opsonization of neutrophils (p<0.05). NAC treatment also ameliorated systemic changes in pulmonary and renal tissue damage in all microscopic parameters (p<0.05). Uncontrolled and defective neutrophil functions could provoke severe systemic inflammatory responses. In addition to local inflammation and necrosis, severe systemic responses and histopathological changes in extrapancreatic vital organs occur during AP. Treatment with antioxidant NAC significantly reverses detrimental systemic responses in extrapancreatic vital organs by significantly ameliorating neutrophil functions despite ongoing AP.

  5. Functional MRI and diffusion tensor imaging of brain reorganization after experimental stroke.

    PubMed

    Dijkhuizen, Rick M; van der Marel, Kajo; Otte, Willem M; Hoff, Erik I; van der Zijden, Jet P; van der Toorn, Annette; van Meer, Maurits P A

    2012-03-01

    The potential of the adult brain to reorganize after ischemic injury is critical for functional recovery and provides a significant target for therapeutic strategies to promote brain repair. Despite the accumulating evidence of brain plasticity, the interaction and significance of morphological and physiological modifications in post-stroke brain tissue remain mostly unclear. Neuroimaging techniques such as functional MRI (fMRI) and diffusion tensor imaging (DTI) enable in vivo assessment of the spatial and temporal pattern of functional and structural changes inside and outside ischemic lesion areas. This can contribute to the elucidation of critical aspects in post-stroke brain remodeling. Task/stimulus-related fMRI, resting-state fMRI, or pharmacological MRI enables direct or indirect measurement of neuronal activation, functional connectivity, or neurotransmitter system responses, respectively. DTI allows estimation of the structural integrity and connectivity of white matter tracts. Together, these MRI methods provide an unprecedented means to (a) measure longitudinal changes in tissue structure and function close by and remote from ischemic lesion areas, (b) evaluate the organizational profile of neural networks after stroke, and (c) identify degenerative and restorative processes that affect post-stroke functional outcome. Besides, the availability of MRI in clinical institutions as well as research laboratories provides an optimal basis for translational research on stroke recovery. This review gives an overview of the current status and perspectives of fMRI and DTI applications to study brain reorganization in experimental stroke models.

  6. Stereotactic neurosurgery in the United Kingdom: the hundred years from Horsley to Hariz.

    PubMed

    Pereira, Erlick A C; Green, Alexander L; Nandi, Dipankar; Aziz, Tipu Z

    2008-09-01

    The history of stereotactic neurosurgery in the United Kingdom of Great Britain and Northern Ireland is reviewed. Horsley and Clarke's primate stereotaxy at the turn of the 20th century and events surrounding it are described, including Mussen's development of a human version of the apparatus. Stereotactic surgery after the Second World War is reviewed, with an emphasis on the pioneering work of Gillingham, Hitchcock, Knight, and Watkins and the contributions from Bennett, Gleave, Hughes, Johnson, McKissock, McCaul, and Dutton after the influences of Dott, Cairns, and Jefferson. Forster's introduction of gamma knife radiosurgery is summarized, as is the application of computed tomography by Hounsfield and Ambrose. Contemporary contributions to the present day from Bartlett, Richardson, Miles, Thomas, Gill, Aziz, Hariz, and others are summarized. The current status of British stereotactic neurosurgery is discussed.

  7. Virtual reality simulation: basic concepts and use in endoscopic neurosurgery training.

    PubMed

    Cohen, Alan R; Lohani, Subash; Manjila, Sunil; Natsupakpong, Suriya; Brown, Nathan; Cavusoglu, M Cenk

    2013-08-01

    Virtual reality simulation is a promising alternative to training surgical residents outside the operating room. It is also a useful aide to anatomic study, residency training, surgical rehearsal, credentialing, and recertification. Surgical simulation is based on a virtual reality with varying degrees of immersion and realism. Simulators provide a no-risk environment for harmless and repeatable practice. Virtual reality has three main components of simulation: graphics/volume rendering, model behavior/tissue deformation, and haptic feedback. The challenge of accurately simulating the forces and tactile sensations experienced in neurosurgery limits the sophistication of a virtual simulator. The limited haptic feedback available in minimally invasive neurosurgery makes it a favorable subject for simulation. Virtual simulators with realistic graphics and force feedback have been developed for ventriculostomy, intraventricular surgery, and transsphenoidal pituitary surgery, thus allowing preoperative study of the individual anatomy and increasing the safety of the procedure. The authors also present experiences with their own virtual simulation of endoscopic third ventriculostomy.

  8. Evaluation of the Department of Neurosurgery of the Seoul National University Hospital

    PubMed Central

    2013-01-01

    The Department of Neurosurgery (DNS) of the Seoul National University Hospital (SNUH), belongs to the largest and oldest such institutions in Korea. Because of its growing reputation it is hardly surprising that the DNS draws visitor and scholars for clinical education and academic exchange from far beyond Korea. I myself visited the SNUH in February and March 2013. During this time I composed this evaluation in which I compare the DNS to my home Department at the Johannes Gutenberg-University in Mainz/Germany, as well as the situation of Neurosurgery in Korea and Germany in general. In the first part this evaluation summarizes data concerning equipment, staff and organizational structure, as well as educational and scientific issues of the DNS. In the second part some issues of interest are discussed in special regard to the corresponding practices in Germany. PMID:23908698

  9. Augmented Reality in Neurosurgery: A Review of Current Concepts and Emerging Applications.

    PubMed

    Guha, Daipayan; Alotaibi, Naif M; Nguyen, Nhu; Gupta, Shaurya; McFaul, Christopher; Yang, Victor X D

    2017-05-01

    Augmented reality (AR) superimposes computer-generated virtual objects onto the user's view of the real world. Among medical disciplines, neurosurgery has long been at the forefront of image-guided surgery, and it continues to push the frontiers of AR technology in the operating room. In this systematic review, we explore the history of AR in neurosurgery and examine the literature on current neurosurgical applications of AR. Significant challenges to surgical AR exist, including compounded sources of registration error, impaired depth perception, visual and tactile temporal asynchrony, and operator inattentional blindness. Nevertheless, the ability to accurately display multiple three-dimensional datasets congruently over the area where they are most useful, coupled with future advances in imaging, registration, display technology, and robotic actuation, portend a promising role for AR in the neurosurgical operating room.

  10. [Development of automatic navigation measuring system using template-matching software in image guided neurosurgery].

    PubMed

    Watanabe, Yohei; Hayashi, Yuichiro; Fujii, Masazumi; Kimura, Miyuki; Sugiura, Akihiro; Tsuzaka, Masatoshi; Wakabayashi, Toshihiko

    2010-02-20

    An image-guided neurosurgery and neuronavigation system based on magnetic resonance imaging has been used as an indispensable tool for resection of brain tumors. Therefore, accuracy of the neuronavigation system, provided by periodic quality assurance (QA), is essential for image-guided neurosurgery. Two types of accuracy index, fiducial registration error (FRE) and target registration error (TRE), have been used to evaluate navigation accuracy. FRE shows navigation accuracy on points that have been registered. On the other hand, TRE shows navigation accuracy on points such as tumor, skin, and fiducial markers. This study shows that TRE is more reliable than FRE. However, calculation of TRE is a time-consuming, subjective task. Software for QA was developed to compute TRE. This software calculates TRE automatically by an image processing technique, such as automatic template matching. TRE was calculated by the software and compared with the results obtained by manual calculation. Using the software made it possible to achieve a reliable QA system.

  11. Problems with phenytoin administration in neurology/neurosurgery ITU patients receiving enteral feeding.

    PubMed

    Kitchen, D; Smith, D

    2001-06-01

    Our objective was to investigate the relationship between phenytoin bioavailability, enteral feeding and serum albumin levels in patients admitted to neurology/neurosurgery ITU, via case studies of three patients. The research was performed at the Walton centre for Neurology and Neurosurgery NHS Trust, Liverpool, England, and our subjects consisted of three cases admitted to ITU (1 status epilepticus, 1 post-trauma and 1 post-subarachnoid haemorrhage (SAH)). Phenytoin levels were assessed in relation to the type of feeding and serum albumin levels. We found evidence of a complex relationship between phenytoin levels, enteral feeding and serum albumin in patients in the neuro ITU setting. We conclude that, in this setting the patient's phenytoin needs to be closely monitored and treated aggressively to maintain therapeutic levels. They should also be followed up during rehabilitation to avoid toxicity.

  12. Neurosurgery in Rwanda during a United Nations peace-keeping mission.

    PubMed

    Rosenfeld, J V

    1997-05-01

    An analysis of the neurosurgical component of the medical support provided by a United Nations peace-keeping mission in Rwanda is presented. The Australian Defence Force contingent provided medical support to the United Nations and the civilian population. Eight hundred thirty-eight procedures were performed during 12 months. A wide range of surgery was encompassed, with neurosurgery accounting for 17 (2%) of the total operations: compound depressed fractured skull, 5; intracranial pressure monitor, 2; burr holes for acute head injury and chronic subdural hematoma, 2; skull osteomyelitis debridement, 1; rib-graft cranioplasty, 2; scalp rotation flap, 1; congenital myelomeningocele, 2; occipital meningocele, 1; craniofacial approach to Le Fort III fracture, 1. A broad range of neurosurgical procedures have been performed. The overall numbers of neurosurgical operations were small, but they were successfully performed by general surgeons. Familiarity with neurosurgery is necessary in predeployment training of military surgeons working in a remote location with limited resources.

  13. Propionibacterium Acnes Brain Abscess in an Immunocompetent Man in the Absence of Prior Neurosurgery.

    PubMed

    Odunukan, Olufunso W; Masannat, Fares; Baka, J Jeff

    2016-02-01

    Propionibacterium acnes is a rare, but established, cause of intracranial abscesses. We describe a case of P. acnes brain abscess in an immunocompetent man without prior neurosurgery. A 49-year old man with mild psoriasis presented with a two-week history of gait changes, generalized weakness and a two-day history of headaches, aphasia and confusion. Imaging revealed a left thalamic mass and surgical biopsy suggested a pyogenic abscess. Cultures of biopsy samples of the abscess grew P. acnes alone. MRI and serial neurological exam showed marked clinical improvement with intravenous antibiotics. The significant reduction in the abscess was sustained on MRI obtained at six weeks after completion of antibiotic therapy. In conclusion, P. acnes must be considered as a differential diagnosis in individuals presenting with features suggestive of a brain abscess even in the absence of immunosuppression or previous neurosurgery.

  14. Free-access open-source e-learning in comprehensive neurosurgery skills training.

    PubMed

    Jotwani, Payal; Srivastav, Vinkle; Tripathi, Manjul; Deo, Rama Chandra; Baby, Britty; Damodaran, Natesan; Singh, Ramandeep; Suri, Ashish; Bettag, Martin; Roy, Tara Sankar; Busert, Christoph; Mehlitz, Marcus; Lalwani, Sanjeev; Garg, Kanwaljeet; Paul, Kolin; Prasad, Sanjiva; Banerjee, Subhashis; Kalra, Prem; Kumar, Subodh; Sharma, Bhavani Shankar; Mahapatra, Ashok Kumar

    2014-01-01

    Since the end of last century, technology has taken a front seat in dispersion of medical education. Advancements of technology in neurosurgery and traditional training methods are now being challenged by legal and ethical concerns of patient safety, resident work-hour restriction and cost of operating-room time. To supplement the existing neurosurgery education pattern, various e-learning platforms are introduced as structured, interactive learning system. This study focuses on the concept, formulation, development and impact of web based learning platforms dedicated to neurosurgery discipline to disseminate education, supplement surgical knowledge and improve skills of neurosurgeons. 'Neurosurgery Education and Training School (NETS), e-learning platform' has integration of web-based technologies like 'Content Management System' for organizing the education material and 'Learning Management System' for updating neurosurgeons. NETS discussion forum networks neurosurgeons, neuroscientists and neuro-technologists across the globe facilitating collaborative translational research. Multi-authored neurosurgical e-learning material supplements the deficiencies of regular time-bound education. Interactive open-source, global, free-access e-learning platform of NETS has around 1) 425 visitors/month from 73 countries; ratio of new visitors to returning visitors 42.3; 57.7 (2); 64,380 views from 190 subscribers for surgical videos, 3-D animation, graphics based training modules (3); average 402 views per post. The e-Learning platforms provide updated educational content that make them "quick, surf, find and extract" resources. e-Learning tools like web-based education, social interactive platform and question-answer forum will save unnecessary expenditure of time and travel of neurosurgeons seeking knowledge. The need for free access platforms is more pronounced for the neurosurgeons and patients in developing nations.

  15. The Spectrum of Altmetrics in Neurosurgery: The Top 100 "Trending" Articles in Neurosurgical Journals.

    PubMed

    Wang, Justin; Alotaibi, Naif M; Ibrahim, George M; Kulkarni, Abhaya V; Lozano, Andres M

    2017-07-01

    Social media are increasingly used for the dissemination of scientific publications by most medical journals. The role of social media in increasing awareness of published works in neurosurgery has not been previously explored. Here, we present a qualitative analysis of the highest trending works in neurosurgery along with a correlation analysis with their social media metrics. We performed a comprehensive search for neurosurgical publications using the Altmetric database. The Altmetric database provides a weighted total score of all online mentions for an article received on Facebook, Twitter, blogs, and mainstream media sources. Our search was limited to articles published within the social media era (January 2010-January 2017). Descriptive and correlational statistics were performed for all articles. The top 100 articles in altmetrics were selected for qualitative analysis. A total of 5794 articles were included in this study. The average Altmetric score in neurosurgical articles was 4.7 (standard deviation ±22.4). Journals with a social media account had significantly higher Altmetric scores for their articles compared with those without an account (P < 0.0001). The number of tweets and online mentions in news outlets had the strongest correlation values with Altmetric scores. The top 100 articles in altmetrics belonged primarily to the Journal of Neurosurgery (33%) followed by Neurosurgery (29%). This is the first study that details the spectrum of Altmetric scores among neurosurgical journals. Social media presence for journals is important for greater outreach and engagement. Prediction of traditional citation using altmetrics data requires a future prospective study. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The present and future of quality measures and public reporting in neurosurgery.

    PubMed

    Bekelis, Kimon; McGirt, Matthew J; Parker, Scott L; Holland, Christopher M; Davies, Jason; Devin, Clinton J; Atkins, Tyler; Knightly, Jack; Groman, Rachel; Zyung, Irene; Asher, Anthony L

    2015-12-01

    Quality measurement and public reporting are intended to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. However, regulatory implementation has created a complex network of reporting requirements for physicians and medical practices. These include Medicare's Physician Quality Reporting System, Electronic Health Records Meaningful Use, and Value-Based Payment Modifier programs. The common denominator of all these initiatives is that to avoid penalties, physicians must meet "generic" quality standards that, in the case of neurosurgery and many other specialties, are not pertinent to everyday clinical practice and hold specialists accountable for care decisions outside of their direct control. The Centers for Medicare and Medicaid Services has recently authorized alternative quality reporting mechanisms for the Physician Quality Reporting System, which allow registries to become subspecialty-reporting mechanisms under the Qualified Clinical Data Registry (QCDR) program. These programs further give subspecialties latitude to develop measures of health care quality that are relevant to the care provided. As such, these programs amplify the power of clinical registries by allowing more accurate assessment of practice patterns, patient experiences, and overall health care value. Neurosurgery has been at the forefront of these developments, leveraging the experience of the National Neurosurgery Quality and Outcomes Database to create one of the first specialty-specific QCDRs. Recent legislative reform has continued to change this landscape and has fueled optimism that registries (including QCDRs) and other specialty-driven quality measures will be a prominent feature of federal and private sector quality improvement initiatives. These physician- and patient-driven methods will allow neurosurgery to underscore the value of interventions, contribute to the development of sustainable health care

  17. A virtual reality surgery simulation of cutting and retraction in neurosurgery with force-feedback.

    PubMed

    Wang, P; Becker, A A; Jones, I A; Glover, A T; Benford, S D; Greenhalgh, C M; Vloeberghs, M

    2006-10-01

    A virtual-reality surgical simulator aimed at neurosurgery is presented. The simulator utilises boundary element (BE) technology to develop real-time realistic deformable models of the brain. The simulator incorporates the simulation of surgical prodding, pulling and cutting. Advanced features include the separation the cut surfaces by retractors and post-cutting deformations. The experience of virtual surgery is enhanced by implementing 3D stereo-vision and the use of two hand-held force-feedback devices.

  18. The role of simulation in neurosurgical education: a survey of 99 United States neurosurgery program directors.

    PubMed

    Ganju, Aruna; Aoun, Salah G; Daou, Marc R; El Ahmadieh, Tarek Y; Chang, Alice; Wang, Lucy; Batjer, H Hunt; Bendok, Bernard R

    2013-11-01

    With the reduction of resident work hours and the increasing focus on patient safety, it has become evident that simulation has a growing role to play in surgical education. We surveyed the program directors of 99 U.S. Neurosurgery programs in an effort to better understand how simulation can be implemented in Neurosurgery and to gain insight into key issues that are currently being discussed amongst Neurosurgical educators. A 14-item questionnaire was emailed to 99 Neurosurgery residency program directors. Questions assessed the clinical impact of simulation, the role of simulation in academia, the investments required in time and money, and the model best suited for simulation. The survey response rate was 53.5%. Seventy-two percent of respondents believed that simulation would improve patient outcome, 74% that it could supplement conventional training, but only 25% that it could replace it. The majority strongly believed that it could help preparing complex cases and could be of use to attending faculty. Forty-five percent thought that residents should achieve pre-defined levels of proficiency on simulators before working on patients. Seventy-four percent of respondents declared they would make simulator practice mandatory if available, and the majority was willing to invest daily time and considerable funds on simulators. Cadavers were the least preferred models to use compared to virtual simulation and noncadaveric physical models. Simulation should be integrated in Neurosurgery training curricula. The validation of available tools is the next step that will enable the training, acquisition, and testing of neurosurgical skills. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Neurosurgery in the realm of 10(-9), part 1: stardust and nanotechnology in neuroscience.

    PubMed

    Elder, James B; Liu, Charles Y; Apuzzo, Michael L J

    2008-01-01

    Nanotechnology as a science has evolved from notions and speculation to emerge as a prominent combination of science and engineering that stands to impact innumerable aspects of technology. Medicine in general and neurosurgery in particular will benefit greatly in terms of improved diagnostic and therapeutic capabilities. The recent explosion in nanotechnology products, including diverse applications such as beauty products and medical contrast agents, has been accompanied by an ever increasing volume of literature. Recent articles from our institution provided an historical and scientific background of nanotechnology, with a purposeful focus on nanomedicine. Future applications of nanotechnology to neuroscience and neurosurgery were briefly addressed. The present article is the first of two that will further this discussion by providing specific details of current nanotechnology applications and research related to neuroscience and clinical neurosurgery. This article also provides relevant perspective in scale, history, economics, and toxicology. Topics of specific importance to developments or advances of technologies used by neuroscientists and neurosurgeons are presented. In addition, advances in the field of microelectromechanical systems technology are discussed. Although larger than nanoscale, microelectromechanical systems technologies will play an important role in the future of medicine and neurosurgery. The second article will discuss current nanotechnologies that are being, or will be in the near future, incorporated into the armamentarium of the neurosurgeon. The goal of these articles is to keep the neuroscience community abreast of current developments in nanotechnology, nanomedicine, and, in particular, nanoneurosurgery, and to present possibilities for future applications of nanotechnology. As applications of nanotechnology permeate all forms of scientific and medical research, clinical applications will continue to emerge. Physicians of the

  20. Neurosurgery in Egypt: past, present, and future-from pyramids to radiosurgery.

    PubMed

    El Gindi, Sayed

    2002-09-01

    THE CONTEMPORARY DEVELOPMENT of neurosurgery in Egypt is described, with reference to the ancient past and recent American and European influences. This article traces the steps taken by several leading Egyptian pioneers. Egypt, one of the key countries in the Middle East, has led the development of the specialty in the region and has maintained close ties with the international body of neurological surgeons and surgical societies.

  1. The Establishment and Development of Neurosurgery Services in Papua New Guinea.

    PubMed

    Kaptigau, W Matui; Rosenfeld, Jeffrey V; Kevau, Ikau; Watters, David A

    2016-02-01

    Papua New Guinea (PNG) is a developing Pacific Nation of 7.3 million people. Although neurosurgery training was introduced to PNG in the year 2000, it was in 2003 that a neurosurgery service was established. Prior to this time, neurosurgery in PNG was performed by general surgeons, with some assistance from visiting Australian neurosurgeons. Neurosurgical training was introduced to PNG in 2000. The model involved a further 3 years of training for a surgeon who had already completed 4 years of general surgical training. We aim to review the output, outcomes and impact achieved by training the first national neurosurgeon. The data on activity (output) and outcomes were collected prospectively from 2003–2012. Ongoing mentoring and continuing professional development were provided through annual neurosurgical visits from Australia. There were serious limitations in the provision of equipment, with a lack of computerized tomographic or MR imaging, and adjuvant oncological services. There were 1618 neurosurgery admissions, 1020 neurosurgical procedures with a 5.74 % overall mortality. Seventy percent of cases presented as emergencies. There were improved outcomes, particularly for head injuries, whilst hydrocephalus was managed with an acceptable morbidity and revision rate. The training of a neurosurgeon resulted in PNG patients receiving a better range of surgical services, with a lower mortality. The outcomes able to be delivered were limited by late presentations of patients and lack of resources including imaging. These themes are familiar to all low- and middle-income countries (LMICs) and this may serve as a model for other LMIC neurosurgical services to adopt as they consider whether to establish and develop neurosurgical and other sub-specialist surgical services.

  2. Neurosurgery in the decade of the brain. The 1990 AANS presidential address.

    PubMed

    Rhoton, A L

    1990-10-01

    The decade of the 1990's has provided neurosurgery with multiple challenges and opportunities. Numerous developments hold a promise for making the 1990's the most rewarding decade of the 20th century for neurosurgery. The "Decade of the Brain" resolution, adopted by the United States House and Senate and signed into law by President Bush in 1989, has provided the specialty with staggering opportunities. Neurosurgery and the basic and clinical neurosciences would be strengthened by the development of a major new philanthropic organization called the "American Brain Association" that would carry the activities of the Decade of the Brain into the 21st century. Major efforts are being made to improve organized neurosurgery's responsiveness to member needs. These include the strategic planning project undertaken by the Board of Directors of the American Association of Neurological Surgeons (AANS) and efforts to strengthen the Joint Council of State Neurosurgical Societies. The AANS has been extremely active in representing the specialty in legislative matters in Washington and in multiple other forums. This Association has joined The American Board of Neurological Surgery and the Residency Review Committee in responding to orthopedic surgery's proposal for spine fellowships. It is proposed that the logo of the state, regional, and national neurosurgical societies be changed to depict our involvement in spinal surgery (as well as brain surgery) because spinal surgery represents more than half of the total effort of this specialty. The standards of worth and value that provide the driving force behind our work emphasize the need to grow in compassion as manifested by our kindness, sincerity, and concern as we grow in professional competence as reflected by our training, knowledge, and skill.

  3. Neurosurgical Skills Assessment: Measuring Technical Proficiency in Neurosurgery Residents Through Intraoperative Video Evaluations.

    PubMed

    Sarkiss, Christopher A; Philemond, Steven; Lee, James; Sobotka, Stanislaw; Holloway, Terrell D; Moore, Maximillian M; Costa, Anthony B; Gordon, Errol L; Bederson, Joshua B

    2016-05-01

    Although technical skills are fundamental in neurosurgery, there is little agreement on how to describe, measure, or compare skills among surgeons. The primary goal of this study was to develop a quantitative grading scale for technical surgical performance that distinguishes operator skill when graded by domain experts (residents, attendings, and nonsurgeons). Scores provided by raters should be highly reliable with respect to scores from other observers. Neurosurgery residents were fitted with a head-mounted video camera while performing craniotomies under attending supervision. Seven videos, 1 from each postgraduate year (PGY) level (1-7), were anonymized and scored by 16 attendings, 8 residents, and 7 nonsurgeons using a grading scale. Seven skills were graded: incision, efficiency of instrument use, cauterization, tissue handling, drilling/craniotomy, confidence, and training level. A strong correlation was found between skills score and PGY year (P < 0.001, analysis of variance). Junior residents (PGY 1-3) had significantly lower scores than did senior residents (PGY 4-7, P < 0.001, t test). Significant variation among junior residents was observed, and senior residents' scores were not significantly different from one another. Interrater reliability, measured against other observers, was high (r = 0.581 ± 0.245, Spearman), as was assessment of resident training level (r = 0.583 ± 0.278, Spearman). Both variables were strongly correlated (r = 0.90, Pearson). Attendings, residents, and nonsurgeons did not score differently (P = 0.46, analysis of variance). Technical skills of neurosurgery residents recorded during craniotomy can be measured with high interrater reliability. Surgeons and nonsurgeons alike readily distinguish different skill levels. This type of assessment could be used to coach residents, to track performance over time, and potentially to compare skill levels. Developing an objective tool to evaluate surgical performance would be useful

  4. Virtual reality training in neurosurgery: Review of current status and future applications

    PubMed Central

    Alaraj, Ali; Lemole, Michael G.; Finkle, Joshua H.; Yudkowsky, Rachel; Wallace, Adam; Luciano, Cristian; Banerjee, P. Pat; Rizzi, Silvio H.; Charbel, Fady T.

    2011-01-01

    Background: Over years, surgical training is changing and years of tradition are being challenged by legal and ethical concerns for patient safety, work hour restrictions, and the cost of operating room time. Surgical simulation and skill training offer an opportunity to teach and practice advanced techniques before attempting them on patients. Simulation training can be as straightforward as using real instruments and video equipment to manipulate simulated “tissue” in a box trainer. More advanced virtual reality (VR) simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. Methods: A PubMed review of the literature was performed for the MESH words “Virtual reality, “Augmented Reality”, “Simulation”, “Training”, and “Neurosurgery”. Relevant articles were retrieved and reviewed. A review of the literature was performed for the history, current status of VR simulation in neurosurgery. Results: Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and credential surgeons as technically competent. The number of published literature discussing the application of VR simulation in neurosurgery training has evolved over the last decade from data visualization, including stereoscopic evaluation to more complex augmented reality models. With the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Recent studies have shown the coloration of proficiency with those simulators and levels of experience in the real world. Conclusion: Fully immersive technology is starting to be applied to the practice of

  5. Effects of tacrolimus and erythropoietin in experimental spinal cord lesion in rats: functional and histological evaluation

    PubMed Central

    de Mesquita Coutinho, P R; Cristante, A F; de Barros Filho, T E P; Ferreira, R; dos Santos, G B

    2016-01-01

    Study design: Experimental study with rats. Objective: To evaluate functional and histological effects of tacrolimus (FK 506) and erythropoietin (EPO) after experimental spinal cord contusion injury (SCI). Setting: Brazil. Methods: Wistar rats (n=60) were submitted to SCI with the NYU Impactor system. The control group received saline; the EPO group received EPO; the group EPO+FK 506 received EPO associated with tacrolimus and the group FK 506 received tacrolimus only. The Sham group underwent SCI, but did not receive any drug. Locomotor function was evaluated after SCI by BBB (Basso, Beattie and Bresnahan) weekly and by the motor-evoked potential test in 42 days. The spinal cord was histologically evaluated. Results: There was a significant difference between treated and the control groups from the seventh day on for BBB scores, with no difference between the groups EPO and EPO+FK 506 by the end of the study. There were significant differences between groups for necrosis and bleeding, but not for hiperemia, degeneration and cellular infiltrate. Axon neuron count was different between all groups (P=0.001), between EPO+FK 506 and FK 506 (P=0.011) and between EPO+FK 506 and Sham (P=0.002). Amplitude was significantly different between all groups except between control and sham. For latency, there was no difference. Conclusions: This study did not reveal significant differences in the recovery of locomotor function, or in the histological and electrophysiological analysis in animals treated with EPO and tacrolimus after thoracic SCI. PMID:26481712

  6. Methods for exploring the morpho-functional relations of the aortic depressor nerve in experimental diabetes.

    PubMed

    do Carmo, Jussara Márcia; Júnior, Rubens Fazan; Salgado, Helio Cesar; Fazan, Valéria Paula Sassoli

    2011-01-30

    The present study investigated morpho-functional relations of the aortic depressor nerve (ADN) 5, 15 and 120 days after the onset of streptozotocin-induced diabetes in rats. Time control animals received vehicle. Under pentobarbital anesthesia, ADN activity was recorded simultaneously with arterial pressure. After the recordings, nerves were prepared for light microscopy study and morphometry. ADN function was accessed by means of pressure-nerve activity curve (fitted by sigmoidal regression) and cross-spectral analysis between mean arterial pressure (MAP) and ADN activity. The relation between morphological (myelinated fibers number and density, total myelin area, total fiber area and percentage of occupancy) and functional (gain, signal/noise relation, frequency) parameters were accessed by linear regression analysis and correlation coefficient calculations. Functional parameters obtained by means of the sigmoidal regression curve as well as by cross-spectral analysis were similar in diabetic and control rats. Morphometric parameters of the ADN were similar between groups 5 days after the onset of diabetes. Average myelin area and myelinated fiber area were significantly smaller on diabetic rats 15 and 120 days after the onset of diabetes, being the myelinated fiber and respective axons area and diameter also smaller on 120 days group. Nevertheless, G ratio (ratio between axon and fiber diameter) was nearly 0.6 and not different between groups or experimental times. No significant relationship between morphological and functional parameters was detected in all experimental groups. The present study suggests that ADN diabetic neuropathy was time-dependent, with damage to myelinated fibers to be the primary event, not evidenced by physiological methods.

  7. Laser neurosurgery: A systematic analysis of magnetic resonance-guided laser interstitial thermal therapies.

    PubMed

    Lagman, Carlito; Chung, Lawrance K; Pelargos, Panayiotis E; Ung, Nolan; Bui, Timothy T; Lee, Seung J; Voth, Brittany L; Yang, Isaac

    2017-02-01

    Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a novel minimally invasive modality that uses heat from laser probes to destroy tissue. Advances in probe design, cooling mechanisms, and real-time MR thermography have increased laser utilization in neurosurgery. The authors perform a systematic analysis of two commercially available MRgLITT systems used in neurosurgery: the Visualase® thermal therapy and NeuroBlate® Systems. Data extraction was performed in a blinded fashion. Twenty-two articles were included in the quantitative synthesis. A total of 223 patients were identified with the majority having undergone treatment with Visualase (n=154, 69%). Epilepsy was the most common indication for Visualase therapy (n=8 studies, 47%). Brain mass was the most common indication for NeuroBlate therapy (n=3 studies, 60%). There were no significant differences, except in age, wherein the NeuroBlate group was nearly twice as old as the Visualase group (p<0.001). Frame, total complications, and length-of-stay (LOS) were non-significant when adjusted for age and number of patients. Laser neurosurgery has evolved over recent decades. Clinical indications are currently being defined and will continue to emerge as laser technologies become more sophisticated. Head-to-head comparison of these systems was difficult given the variance in indications (and therefore patient population) and disparate literature.

  8. Third-generation cephalosporins as antibiotic prophylaxis in neurosurgery: what's the evidence?

    PubMed

    Liu, Weiming; Neidert, Marian Christoph; Groen, Rob J M; Woernle, Christoph Michael; Grundmann, Hajo

    2014-01-01

    To analyze the role of third-generation cephalosporins as prophylactic antibiotics in neurosurgery. We reviewed the literature for data from randomized controlled trials (RCTs) on third-generation cephalosporins compared to other antibiotic regimen in neurosurgery. End point of the RCTs was the occurrence of surgical site infections (SSIs)--data were pooled in a fixed-effects meta-analysis. Five randomized controlled trials enrolling a total of 2209 patients were identified. The pooled odds ratio for SSIs (overall) with third-generation cephalosporins prophylaxis in the five RCTs was 0.94 (95% CI, 0.59-1.52; P=0.81). No significant difference between third-generation cephalosporins and alternative regimen was identified. When analyzing organ SSIs (osteomyelitis, meningitis, and others intracranial infections) in data derived from four RCTs (1596 patients), third-generation cephalosporins failed to show superiority (pooled odds ratio 0.88; 95% CI 0.45-1.74; P=0.72). Third-generation cephalosporin antibiotic prophylaxis fails to show superiority over conventional regimens regarding both incisional and organ related SSIs in neurosurgery. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. The National Neurosurgery Quality and Outcomes Database Qualified Clinical Data Registry: 2015 measure specifications and rationale.

    PubMed

    Parker, Scott L; McGirt, Matthew J; Bekelis, Kimon; Holland, Christopher M; Davies, Jason; Devin, Clinton J; Atkins, Tyler; Knightly, Jack; Groman, Rachel; Zyung, Irene; Asher, Anthony L

    2015-12-01

    Meaningful quality measurement and public reporting have the potential to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. Recent developments in national quality reporting programs, such as the Centers for Medicare & Medicaid Services Qualified Clinical Data Registry (QCDR) reporting option, have enhanced the ability of specialty groups to develop relevant quality measures of the care they deliver. QCDRs will complete the collection and submission of Physician Quality Reporting System (PQRS) quality measures data on behalf of individual eligible professionals. The National Neurosurgery Quality and Outcomes Database (N(2)QOD) offers 21 non-PQRS measures, initially focused on spine procedures, which are the first specialty-specific measures for neurosurgery. Securing QCDR status for N(2)QOD is a tremendously important accomplishment for our specialty. This program will ensure that data collected through our registries and used for PQRS is meaningful for neurosurgeons, related spine care practitioners, their patients, and other stakeholders. The 2015 N(2)QOD QCDR is further evidence of neurosurgery's commitment to substantively advancing the health care quality paradigm. The following manuscript outlines the measures now approved for use in the 2015 N(2)QOD QCDR. Measure specifications (measure type and descriptions, related measures, if any, as well as relevant National Quality Strategy domain[s]) along with rationale are provided for each measure.

  10. Laser speckle contrast imaging of cerebral blood flow in humans during neurosurgery: a pilot clinical study

    NASA Astrophysics Data System (ADS)

    Parthasarathy, Ashwin B.; Weber, Erica L.; Richards, Lisa M.; Fox, Douglas J.; Dunn, Andrew K.

    2010-11-01

    Monitoring cerebral blood flow (CBF) during neurosurgery can provide important physiological information for a variety of surgical procedures. CBF measurements are important for assessing whether blood flow has returned to presurgical baseline levels and for assessing postsurgical tissue viability. Existing techniques for intraoperative monitoring of CBF based on magnetic resonance imaging are expensive and often impractical, while techniques such as indocyanine green angiography cannot produce quantitative measures of blood flow. Laser speckle contrast imaging (LSCI) is an optical technique that has been widely used to quantitatively image relative CBF in animal models in vivo. In a pilot clinical study, we adapted an existing neurosurgical operating microscope to obtain LSCI images in humans in real time during neurosurgery under baseline conditions and after bipolar cautery. Simultaneously recorded ECG waveforms from the patient were used to develop a filter that helped reduce measurement variabilities due to motion artifacts. Results from this study demonstrate the feasibility of using LSCI to obtain blood flow images during neurosurgeries and its capability to produce full field CBF image maps with excellent spatial resolution in real-time with minimal disruption to the surgical procedure.

  11. The Richard C. Schneider Lecture. New dimensions of neurosurgery in the realm of high technology: possibilities, practicalities, realities.

    PubMed

    Apuzzo, M L

    1996-04-01

    Fueled by a buoyant economy, popular attitudes and demands, and parallel progress in transferable technical and biological areas, neurosurgery has enjoyed a remarkable quarter of a century of progress. Developmental trends in the discipline have included the following: 1) a refinement of preoperative definition of the structural substrate, 2) miniaturization of operative corridors, 3) reduction of operative trauma, 4) increased effectiveness at the target site, and 5) incorporation of improved technical adjuvants and physical operative tools into treatment protocols. In particular, the computer has become a formidable ally in diagnostic and surgical events. Trends in technical development indicate that we are entering an exciting era of advanced surgery of the human cerebrum, which is heralded by the following: 1) current developments in areas of imaging, sensors, and visualization; 2) new devices for localization and navigation; 3) new capabilities for action at the target point; and 4) innovative concepts related to advanced operative venues. Imaging has provided structurally based surgical maps, which now are being given the new dimension of function in complex and integrated formats for preoperative planning and intraoperative tactical direction. Cerebral localization and navigation based on these advances promise to provide further refinement to the field of stereotactic neurosurgery, as linked systems are superseded by more flexible nonlinked methodologies in functionally defined volume-oriented navigational databases. Target point action now includes not only ablative capabilities through micro-operative methods and the use of stereotactically directed high-energy forms but also the emergence of restorative capabilities through applications of principles of genetic engineering in the areas of molecular and cellular neurosurgery. Complex, dedicated, and self-contained operative venues will be required to optimize the emergence and development of these

  12. Atmospheric channel transfer function estimation from experimental free-space optical communications data

    NASA Astrophysics Data System (ADS)

    Reinhardt, Colin N.; Tsintikidis, Dimitris; Hammel, Stephen; Kuga, Yasuo; Ritcey, James A.; Ishimaru, Akira

    2012-03-01

    Using an 850-nanometer-wavelength free-space optical (FSO)communications system of our own design, we acquired field data for the transmitted and received signals in fog at Point Loma, CA for a range of optical depths within the multiple-scattering regime. Statistical estimators for the atmospheric channel transfer function and the related coherency function were computed directly from the experimental data. We interpret the resulting channel transfer function estimates in terms of the physics of the atmospheric propagation channel and fog aerosol particle distributions. We investigate the behavior of the estimators using both real field-test data and simulated propagation data. We compare the field-data channel transfer function estimates against the outputs from a computationally-intensive radiative-transfer theory model-based approach, which we also developed previously for the FSO multiple-scattering atmospheric channel. Our results show that the data-driven channel transfer function estimates are in close agreement with the radiative transfer modeling, and provide comparable receiver signal detection performance improvements while being significantly less time and computationally-intensive.

  13. Real-time correction scheme for calibration and implementation of microscope-based image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

    Sun, Hai; Farid, Hany; Hartov, Alex; Lunn, Karen E.; Roberts, David W.; Paulsen, Keith D.

    2002-05-01

    Microscope-based image-guided neurosurgery can be divided into three steps: calibration of the microscope optics; registration of the pre-operative images to the operating space; and tracking of the patient and microscope over time. Critical to this overall system is the temporal retention of accurate camera calibration. Classic calibration algorithms are routinely employed to find both intrinsic and extrinsic camera parameters. The accuracy of this calibration, however, is quickly compromised due to the complexity of the operating room, the long duration of a surgical procedure, and the inaccuracies in the tracking system. To compensate for the changing conditions, we have developed an adaptive procedure which responds to accruing registration error. The approach utilizes miniature fiducial markers implanted on the bony rim of the craniotomy site, which remain in the field of view of the operating microscope. A simple error function that enforces the registration of the known fiducial markers is used to update the extrinsic camera parameters. The error function is minimized using a gradient descent. This correction procedure reduces RMS registration errors for cortical features on the surface of the brain by an average of 72%, or 1.5 mm. These errors were reduced to less than 0.6 mm after each correction during the entire surgical procedure.

  14. Comparison between skin-mounted fiducials and bone-implanted fiducials for image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

    Rost, Jennifer; Harris, Steven S.; Stefansic, James D.; Sillay, Karl; Galloway, Robert L., Jr.

    2004-05-01

    Point-based registration for image-guided neurosurgery has become the industry standard. While the use of intrinsic points is appealing because of its retrospective nature, affixing extrinsic objects to the head prior to scanning has been demonstrated to provide much more accurate registrations. Points of reference between image space and physical space are called fiducials. The extrinsic objects which generate those points are fiducial markers. The markers can be broken down into two classifications: skin-mounted and bone-implanted. Each has distinct advantages and disadvantages. Skin-mounted fiducials require simply sticking them on the patient in locations suggested by the manufacturer, however, they can move with tractions placed on the skin, fall off and perhaps the most dangerous problem, they can be replaced by the patient. Bone implanted markers being rigidly affixed to the skull do not present such problems. However, a minor surgical intervention (analogous to dental work) must be performed to implant the markers prior to surgery. Therefore marker type and use has become a decision point for image-guided surgery. We have performed a series of experiments in an attempt to better quantify aspects of the two types of markers so that better informed decisions can be made. We have created a phantom composed of a full-size plastic skull [Wards Scientific Supply] with a 500 ml bag of saline placed in the brain cavity. The skull was then sealed. A skin mimicking material, DragonSkinTM [SmoothOn Company] was painted onto the surface and allowed to dry. Skin mounted fiducials [Medtronic-SNT] and bone-implanted markers [Z-Kat]were placed on the phantom. In addition, three additional bone-implanted markers were placed (two on the base of the skull and one in the eye socket for use as targets). The markers were imaged in CT and 4 MRI sequences (T1-weighted, T2 weighted, SPGR, and a functional series.) The markers were also located in physical space using an Optotrak

  15. Experimental and bioinformatic approaches for interrogating protein-protein interactions to determine protein function.

    PubMed

    Droit, Arnaud; Poirier, Guy G; Hunter, Joanna M

    2005-04-01

    An ambitious goal of proteomics is to elucidate the structure, interactions and functions of all proteins within cells and organisms. One strategy to determine protein function is to identify the protein-protein interactions. The increasing use of high-throughput and large-scale bioinformatics-based studies has generated a massive amount of data stored in a number of different databases. A challenge for bioinformatics is to explore this disparate data and to uncover biologically relevant interactions and pathways. In parallel, there is clearly a need for the development of approaches that can predict novel protein-protein interaction networks in silico. Here, we present an overview of different experimental and bioinformatic methods to elucidate protein-protein interactions.

  16. Topography measurement of freeform specular surfaces using experimental ray tracing and radial basis functions

    NASA Astrophysics Data System (ADS)

    Alinoori, A.; Essameldin, M.; Fleischmann, F.; Henning, T.

    2016-09-01

    Optical deflectometric methods with their inherent potential of high channel capacity with regard to information theory has been of great interest for specular surface topography measurement, where the limited dynamic range needs to be considered in the detection plane. Achieving a final smooth reconstructed surface is the next challenge, because the 2Dintegration methods for the interpolation of the derived data from such sensors are prone to various sources of error such as path dependency, large data sets and secondary reflections. On the other hand, Radial Basis Functions have been studied in this respect for the last years and their characteristics have been widely discussed. In this paper, we introduce our approach for the 3D measurement of specular surfaces by means of Experimental Ray Tracing and Radial Basis Functions integration. We present simulations and discuss the reconstructed surface and the resulting reconstruction error results.

  17. Experimental Design and Interpretation of Functional Neuroimaging Studies of Cognitive Processes

    PubMed Central

    Caplan, David

    2008-01-01

    This article discusses how the relation between experimental and baseline conditions in functional neuroimaging studies affects the conclusions that can be drawn from a study about the neural correlates of components of the cognitive system and about the nature and organization of those components. I argue that certain designs in common use—in particular the contrast of qualitatively different representations that are processed at parallel stages of a functional architecture—can never identify the neural basis of a cognitive operation and have limited use in providing information about the nature of cognitive systems. Other types of designs—such as ones that contrast representations that are computed in immediately sequential processing steps and ones that contrast qualitatively similar representations that are parametrically related within a single processing stage—are more easily interpreted. PMID:17979122

  18. Experimental nuclear level densities and {gamma}-ray strength functions in Sc and V isotopes

    SciTech Connect

    Larsen, A. C.; Guttormsen, M.; Ingebretsen, F.; Messelt, S.; Rekstad, J.; Siem, S.; Syed, N. U. H.; Chankova, R.; Loennroth, T.; Schiller, A.; Voinov, A.

    2008-04-17

    The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract nuclear level density and {gamma}-ray strength function from first-generation {gamma}-ray spectra. This method is applied on the nuclei {sup 44,45}Sc and {sup 50,51}V in this work. The experimental level densities of {sup 44,45}Sc are compared to calculated level densities using a microscopic model based on BCS quasiparticles within the Nilsson level scheme. The {gamma}-ray strength functions are also compared to theoretical expectations, showing an unexpected enhancement of the {gamma}-ray strength for low {gamma} energies (E{sub {gamma}}{<=}3 MeV) in all the isotopes studied here. The physical origin of this enhancement is not yet understood.

  19. Electronic and optical response of functionalized Ru(II) complexes: joint theoretical and experimental study

    SciTech Connect

    Kilina, Svetlana; Tretiak, Sergei; Sykora, Milan; Albert, Victor; Badaeva, Ekaterina; Koposov, Alexey

    2008-01-01

    New photovoltaic and photocatalysis applications have been recently proposed based on the hybrid Ru(II)-bipyridine-complex/semiconductor quantum dot systems. In order to attach the Ru(II) complex to the surface of a semiconductor, a linking bridge -- a carboxyl group -- needs to be added to one or two of the 2,2'-bipyridine (bpy) ligands. Such changes in the ligand structure affect electronic and optical properties and, consequently, the charge transfer reactivity of Ru(II)-systems. In this study, we analyze the effects brought by functionalization of bipyridine ligands with the methyl, carboxyl, and carboxilate groups on the electronic structure and optical response of the [Ru(bpy){sub 3}]{sup 2+} complex. First principle calculations based on density functional theory (DFT) and time dependent DFT (TDDFT) are used to simulate the ground and excited-state properties, respectively, of functionalized Ru-complexes in the gas phase and acetonitrile solution. In addition, an effective Frenkel exciton model is used to explain the optical activity and splitting patterns of the low-energy excited states in all molecules. All theoretical results nicely complement and allow for detailed interpretation of experimental absorption spectra of Ru-complexes that have been done in parallel with our theoretical investigations. We found that the carboxyl group breaks the degeneracy of two low-energy optically bright excited states and red-shifts the absorption spectrum, while leaves ionization and affinity energies of complexes almost unchanged. Experimental studies show that deprotonation of the carboxyl group in the Ru-complexes results in a slight blue shift and decrease of oscillator strengths of the low energy absorption peaks. Comparison of experimental and theoretical linear response spectra of deprotonated complexes demonstrate strong agreement if the theoretical calculations are performed with the addition of a dielectric continuum model. A polar solvent is found to play an

  20. Long-term behavioral assessment of function in an experimental model for ischemic stroke.

    PubMed

    Encarnacion, Angelo; Horie, Nobutaka; Keren-Gill, Hadar; Bliss, Tonya M; Steinberg, Gary K; Shamloo, Mehrdad

    2011-03-30

    Middle cerebral artery occlusion (MCAO) in rats is a well-studied experimental model for ischemic stroke leading to brain infarction and functional deficits. Many preclinical studies have focused on a small time window after the ischemic episode to evaluate functional outcome for screening therapeutic candidates. Short evaluation periods following injury have led to significant setbacks due to lack of information on the delayed effects of treatments, as well as short-lived and reversible neuroprotection, so called false-positive results. In this report, we evaluated long-term functional deficit for 90 days after MCAO in two rat strains with two durations of ischemic insult, in order to identify the best experimental paradigm to assess injury and subsequent recovery. Behavioral outcomes were measured pre-MCAO followed by weekly assessment post-stroke. Behavioral tests included the 18-point composite neurological score, 28-point neuroscore, rearing test, vibrissae-evoked forelimb placing test, foot fault test and the CatWalk. Brain lesions were assessed to correlate injury to behavior outcomes at the end of study. Our results indicate that infarction volume in Sprague-Dawley rats was dependent on occlusion duration. In contrast, the infarction volume in Wistar rats did not correlate with the duration of ischemic episode. Functional outcomes were not dependent on occlusion time in either strain; however, measurable deficits were detectable long-term in limb asymmetry, 18- and 28-point neuroscores, forelimb placing, paw swing speed, and gait coordination. In conclusion, these behavioral assays, in combination with an extended long-term assessment period, can be used for evaluating therapeutic candidates in preclinical models of ischemic stroke. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. The Experimental Tobacco Marketplace I: Substitutability as a Function of the Price of Conventional Cigarettes.

    PubMed

    Quisenberry, Amanda J; Koffarnus, Mikhail N; Hatz, Laura E; Epstein, Leonard H; Bickel, Warren K

    2016-07-01

    Behavioral economic studies of nicotine product consumption have traditionally examined substitution between two products and rarely examined substitution with more products. Increasing numbers of tobacco products available for commercial sale leads to more possible cross-product interactions, indicating a need to examine substitution in more complex arrangements that closely mirror the tobacco marketplace. The experimental tobacco marketplace (ETM) is an experimental online store that displays pictures, information, and prices for several tobacco products. Smokers were endowed with an account balance based on their weekly tobacco purchases. Participants then made potentially real purchases for seven (Experiment 1) or six (Experiment 2) tobacco/nicotine products under four price conditions for conventional cigarettes while prices for other products remained constant. Smokers returned 1 week later to report tobacco/nicotine use and return unused products for a refund. In Experiment 1 (n = 22), cigarette purchasing decreased as a function of price. Substitution was greatest for electronic cigarettes and cigarillos and significant for electronic cigarettes. Experiment 2 (n = 34) was a replication of Experiment 1, but with cigarillos unavailable in the ETM. In Experiment 2, cigarette purchases decreased as a function of price. Substitution was robust and significant for electronic cigarettes and Camel Snus. The ETM is a novel, practical assay that mimics the real-world marketplace, and functions as a simple research tool for both researchers and participants. Across the two experiments the product mix in the ETM altered which products functioned as substitutes suggesting complex interactions between purchasing and product availability. This article adds a novel method of collecting purchasing data that mimics real world purchasing to the existing literature. The ETM is a practical avenue by which to study both hypothetical and potentially real purchasing. © The Author

  2. The Experimental Tobacco Marketplace I: Substitutability as a Function of the Price of Conventional Cigarettes

    PubMed Central

    Quisenberry, Amanda J.; Koffarnus, Mikhail N.; Hatz, Laura E.; Epstein, Leonard H.

    2016-01-01

    Introduction: Behavioral economic studies of nicotine product consumption have traditionally examined substitution between two products and rarely examined substitution with more products. Increasing numbers of tobacco products available for commercial sale leads to more possible cross-product interactions, indicating a need to examine substitution in more complex arrangements that closely mirror the tobacco marketplace. Methods: The experimental tobacco marketplace (ETM) is an experimental online store that displays pictures, information, and prices for several tobacco products. Smokers were endowed with an account balance based on their weekly tobacco purchases. Participants then made potentially real purchases for seven (Experiment 1) or six (Experiment 2) tobacco/nicotine products under four price conditions for conventional cigarettes while prices for other products remained constant. Smokers returned 1 week later to report tobacco/nicotine use and return unused products for a refund. Results: In Experiment 1 (n = 22), cigarette purchasing decreased as a function of price. Substitution was greatest for electronic cigarettes and cigarillos and significant for electronic cigarettes. Experiment 2 (n = 34) was a replication of Experiment 1, but with cigarillos unavailable in the ETM. In Experiment 2, cigarette purchases decreased as a function of price. Substitution was robust and significant for electronic cigarettes and Camel Snus. Conclusions: The ETM is a novel, practical assay that mimics the real-world marketplace, and functions as a simple research tool for both researchers and participants. Across the two experiments the product mix in the ETM altered which products functioned as substitutes suggesting complex interactions between purchasing and product availability. Implications: This article adds a novel method of collecting purchasing data that mimics real world purchasing to the existing literature. The ETM is a practical avenue by which to study both

  3. Experimental design and desirability function approach for development of novel anticancer nanocarrier delivery systems.

    PubMed

    Rafati, H; Mirzajani, F

    2011-01-01

    The therapeutic effects of anticancer drugs would highly improve if problems with low water solubility and toxic adverse reactions could be solved. In this work, a full factorial experimental design was used to develop a polymeric nanoparticulate delivery system as an alternative technique for anticancer drug delivery. Nanoparticles containing tamoxifen citrate were prepared and characterized using an O/W emulsification-solvent evaporation technique and different analytical methods. Scanning Electron Microscopy (SEM), particle size analysis and High Pressure Liquid Chromatography (HPLC) were used for characterization of nanoparticles. Nanoparticles' characteristics including size, size distribution, drug loading and the efficiency of encapsulation were optimized by means of a full factorial experimental design over the influence of four different independent variables and desirability function using Design-Expert software. The resulting tamoxifen loaded nanoparticles showed the best response with particle sizes less than 200 nm, improved encapsulation efficiency of more than 80% and the optimum loading of above 30%. The overall results demonstrate the implication of desirability functionin experimental design as a beneficial approach in nanoparticle drug delivery design.

  4. Vibrational and UV spectroscopic studies of 2-coumaranone by experimental and density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Priya, Y. Sushma; Rao, K. Ramachandra; Chalapathi, P. V.; Satyavani, M.; Veeraiah, A.

    2017-09-01

    The vibrational and electronic properties of 2-coumaranone have been reported in the ground state using experimental techniques (FT-IR, FT-Raman, UV spectra and fluorescence microscopic imaging) and density functional theory (DFT) employing B3LYP correlation with the 6-31G(d, p) basis set. The theoretically reported optimized parameters, vibrational frequencies etc., were compared with the experimental values, which yielded good concurrence between the experimental and calculated values. The assignments of the vibrational spectra were done with the help of normal co-ordinate analysis (NCA) following the Scaled Quantum Mechanical Force Field(SQMFF) methodology. The whole assignments of fundamental modes were based on the potential energy distribution (PED) matrix. The electric dipole moment and the first order hyperpolarizability of the 2-coumaranone have been computed using quantum mechanical calculations. NBO and HOMO, LUMO analyses have been carried out. UV spectrum of 2-coumaranone was recorded in the region 100-300 nm and compared with the theoretical UV spectrum using TD-DFT and SAC-CI methods by which a good agreement is observed. Fluorescence microscopic imaging study reflects that the compound fluoresces in the green-yellow region.

  5. Bi-functionally Graded Electrode Supported SOFC Modeling and Computational Thermal Fluid Analysis for Experimental Design

    SciTech Connect

    Shi, J.; Xue, X.

    2011-01-01

    A comprehensive 3D CFD model is developed for a bi-electrode supported cell (BSC) SOFC. The model includes complicated transport phenomena of mass/heat transfer, charge (electron and ion) migration, and electrochemical reaction. The uniqueness of the modeling study is that functionally graded porous electrode property is taken into account, including not only linear but nonlinear porosity distributions. Extensive numerical analysis is performed to elucidate the effects of both porous microstructure distributions and operating condition on cell performance. Results indicate that cell performance is strongly dependent on both operating conditions and porous microstructure distributions of electrodes. Using the proposed fuel/gas feeding design, the uniform hydrogen distribution within porous anode is achieved; the oxygen distribution within the cathode is dependent on porous microstructure distributions as well as pressure loss conditions. Simulation results show that fairly uniform temperature distribution can be obtained with the proposed fuel/gas feeding design. The modeling results can be employed to guide experimental design of BSC test and provide pre-experimental analysis, as a result, to circumvent high cost associated with try-and-error experimental design and setup.

  6. Molecular alterations of canalicular transport systems in experimental models of cholestasis: possible functional correlations.

    PubMed Central

    Trauner, M.

    1997-01-01

    The discovery of unidirectional, ATP-dependent canalicular transport systems (also termed "export pumps") for bile salts, amphiphilic anionic conjugates, lipophilic cations, and phospholipids has opened new opportunities for understanding biliary physiology and the pathophysiology of cholestasis. In addition, ATP-independent canalicular transport systems for glutathione and bicarbonate contribute to (bile acid-independent) bile formation. Canalicular excretion of bile salts and several non-bile acid organic anions is impaired in various experimental models of cholestasis. Recent cloning of several canalicular transport systems now facilitates studies on their molecular regulation in cholestasis. Although the picture is far from complete, experimental evidence now exists that decreased or even absent expression of canalicular transport proteins may explain impaired transport function resulting in hyperbilirubinemia and cholestasis. With the increasing availability of molecular probes for these transport systems in humans, new information on the molecular regulation of canalicular transport proteins in human cholestatic liver diseases is beginning to emerge and should bring new insights into their pathophysiology and treatment. This article gives an overview on molecular alterations of canalicular transport systems in experimental models of cholestasis and discusses the potential implications of these changes for the pathophysiology of cholestasis. PMID:9626757

  7. Characterizing Molecular Structure by Combining Experimental Measurements with Density Functional Theory Computations

    NASA Astrophysics Data System (ADS)

    Lopez-Encarnacion, Juan M.

    2016-06-01

    In this talk, the power and synergy of combining experimental measurements with density functional theory computations as a single tool to unambiguously characterize the molecular structure of complex atomic systems is shown. Here, we bring three beautiful cases where the interaction between the experiment and theory is in very good agreement for both finite and extended systems: 1) Characterizing Metal Coordination Environments in Porous Organic Polymers: A Joint Density Functional Theory and Experimental Infrared Spectroscopy Study 2) Characterization of Rhenium Compounds Obtained by Electrochemical Synthesis After Aging Process and 3) Infrared Study of H(D)2 + Co4+ Chemical Reaction: Characterizing Molecular Structures. J.M. López-Encarnación, K.K. Tanabe, M.J.A. Johnson, J. Jellinek, Chemistry-A European Journal 19 (41), 13646-13651 A. Vargas-Uscategui, E. Mosquera, J.M. López-Encarnación, B. Chornik, R. S. Katiyar, L. Cifuentes, Journal of Solid State Chemistry 220, 17-21

  8. Experimental modifications imply a stimulatory function for male tsetse fly genitalia, supporting cryptic female choice theory.

    PubMed

    Briceño, R D; Eberhard, William G

    2009-07-01

    One of the most sweeping of all patterns in morphological evolution is that animal genitalia tend to diverge more rapidly than do other structures. Abundant indirect evidence supports the cryptic female choice (CFC) explanation of this pattern, which supposes that male genitalia often function to court females during copulation; but direct experimental demonstrations of a stimulatory function have been lacking. In this study, we altered the form of two male genital structures that squeeze the female's abdomen rhythmically in Glossina pallidipes flies. As predicted by theory, this induced CFC against the male: ovulation and sperm storage decreased, while female remating increased. Further experiments showed that these effects were due to changes in tactile stimuli received by the female from the male's altered genitalia, and were not due to other possible changes in the males due to alteration of their genital form. Stimulation from male genital structures also induces females to permit copulation to occur. Together with previous studies of tsetse reproductive physiology, these data constitute the most complete experimental confirmation that sexual selection (probably by CFC) acts on the stimulatory properties of male genitalia.

  9. Regulation of cellular function via electromagnetic field frequency and extracellular environment: A theoretical- experimental approach

    NASA Astrophysics Data System (ADS)

    Taghian, Toloo; Sheikh, Abdul; Narmoneva, Daria; Kogan, Andrei

    2015-03-01

    Application of external electric field (EF) as a non-pharmacological, non-invasive tool to control cell function is of great therapeutic interest. We developed a theoretical-experimental approach to investigate the biophysical mechanisms of EF interaction with cells in electrode-free physiologically-relevant configuration. Our numerical results demonstrated that EF frequency is the major parameter to control cell response to EF. Non-oscillating or low-frequency EF leads to charge accumulation on the cell surface membrane that may mediate membrane initiated cell responses. In contrast, high-frequency EF penetrates the cell membrane and reaches cell cytoplasm, where it may directly activate intracellular responses. The theoretical predictions were confirmed in our experimental studies of the effects of applied EF on vascular cell function. Results show that non-oscillating EF increases vascular endothelial growth factor (VEGF) expression while field polarity controls cell adhesion rate. High-frequency, but not low frequency, EF provides differential regulation of cytoplasmic focal adhesion kinase and VEGF expression depending on the substrate, with increased expression in cells cultured on RGD-rich synthetic hydrogels, and decreased expression for matrigel culture. The authors acknowledge the financial support from the NSF (DMR-1206784 & DMR-0804199 to AK); the NIH (1R21 DK078814-01A1 to DN) and the University of Cincinnati (Interdisciplinary Faculty Research Support Grant to DN and AK).

  10. Comparison between Theoretical Calculation and Experimental Results of Excitation Functions for Production of Relevant Biomedical Radionuclides

    SciTech Connect

    Menapace, E.; Birattari, C.; Bonardi, M.L.; Groppi, F.; Morzenti, S.; Zona, C.

    2005-05-24

    The radionuclide production for biomedical applications has been brought up in the years, as a special nuclear application, at INFN LASA Laboratory, particularly in co-operation with the JRC-Ispra of EC. Mainly scientific aspects concerning radiation detection and the relevant instruments, the measurements of excitation functions of the involved nuclear reactions, the requested radiochemistry studies and further applications have been investigated. On the side of the nuclear data evaluations, based on nuclear model calculations and critically selected experimental data, the appropriate competence has been developed at ENEA Division for Advanced Physics Technologies. A series of high specific activity accelerator-produced radionuclides in no-carrier-added (NCA) form, for uses in metabolic radiotherapy and for PET radiodiagnostics, are investigated. In this work, last revised measurements and model calculations are reviewed for excitation functions of natZn(d,X)64Cu, 66Ga reactions, referring to irradiation experiments at K=38 variable energy Cyclotron of JRC-Ispra. Concerning the reaction data for producing 186gRe and 211At/211gPo (including significant emission spectra) and 210At, most recent and critically selected experimental results are considered and discussed in comparison with model calculations paying special care to pre-equilibrium effects estimate and to the appropriate overall parameterization. Model calculations are presented for 226Ra(p,2n)225Ac reaction, according to the working program of the ongoing IAEA CRP on the matter.

  11. Experimental Measurements and Density Functional Theory Calculations of Continuum Lowering in Strongly Coupled Plasmas

    NASA Astrophysics Data System (ADS)

    Vinko, Sam

    2014-10-01

    An accurate description of the ionization potential depression (IPD) of ions in plasmas due to their interaction with the environment is a fundamental problem in plasma physics, playing a key role in determining the ionization balance, charge state distribution, opacity and plasma equation of state. Here I present the first experimental investigation of the IPD as a function of ionic charge state in a range of dense Mg, Al and Si plasmas, using the Linac Coherent Light Source X-ray free-electron laser. The measurements show significantly larger IPDs than are predicted by the most commonly used models, such as that of Stewart-Pyatt, or the ion-sphere model of Zimmerman-More. Instead, plasma simulations using finite-temperature density functional theory with excited-state projector augmented-wave potentials show excellent agreement with the experimental results and explain the stronger-than-expected continuum lowering through the electronic structure of the valence states in these strong-coupling conditions, which retain much of their atomic characteristics close to the ion core regions. These results have a profound impact on the understanding and modelling of plasmas over a wide range of warm- and hot-dense matter conditions.

  12. State-dependent alpha peak frequency shifts: Experimental evidence, potential mechanisms and functional implications.

    PubMed

    Mierau, Andreas; Klimesch, Wolfgang; Lefebvre, Jérémie

    2017-09-30

    Neural populations produce complex oscillatory patterns thought to implement brain function. The dominant rhythm in the healthy adult human brain is formed by alpha oscillations with a typical power peak most commonly found between 8 and 12Hz. This alpha peak frequency has been repeatedly discussed as a highly heritable and stable neurophysiological "trait" marker reflecting anatomical properties of the brain, and individuals' general cognitive capacity. However, growing evidence suggests that the alpha peak frequency is highly volatile at shorter time scales, dependent on the individuals' "state". Based on the converging experimental and theoretical results from numerous recent studies, here we propose that alpha frequency variability forms the basis of an adaptive mechanism mirroring the activation level of neural populations which has important functional implications. We here integrate experimental and computational perspectives to shed new light on the potential role played by shifts in alpha peak frequency and discuss resulting implications. We further propose a potential mechanism by which alpha oscillations are regulated in a noisy network of spiking neurons in presence of delayed feedback. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Urban artificial light emission function determined experimentally using night sky images

    NASA Astrophysics Data System (ADS)

    Solano Lamphar, Héctor Antonio; Kocifaj, Miroslav

    2016-09-01

    To date, diverse approximations have been developed to interpret the radiance of a night sky due to light emissions from ground-based light sources. The radiant intensity distribution as a function of zenith angle is one of the most unknown properties because of the collective effects of all artificial, private and public lights. The emission function (EF) is, however, a key property in modeling the skyglow under arbitrary conditions, and thus it is equally required by modelers, light pollution researchers, and also experimentalists who are using specialized devices to study the diffuse light of a night sky. In this paper, we present the second generation of a dedicated measuring system intended for routine monitoring of a night sky in any region. The experimental technology we have developed is used to interpret clear sky radiance data recorded at a set of discrete distances from a town (or city) with the aim to infer the fraction of upwardly emitted light (F), that is a parameter scaling the bulk EF. The retrieval of the direct upward emissions has been improved by introducing a weighting factor that is used to eliminate imperfections of experimental data and thus to make the computation of F more stable when processing the radiance data taken at two adjacent measuring points. The field experiments made in three Mexican cities are analyzed and the differences found are discussed.

  14. Anatomic and Functional Connectivity Relationship in Autistic Children During Three Different Experimental Conditions.

    PubMed

    Machado, Calixto; Rodríguez, Rafael; Estévez, Mario; Leisman, Gerry; Melillo, Robert; Chinchilla, Mauricio; Portela, Liana

    2015-10-01

    A group of 21 autistic children were studied for determining the relationship between the anatomic (AC) versus functional (FC) connectivity, considering short-range and long-range brain networks. AC was assessed by the DW-MRI technique and FC by EEG coherence calculation, in three experimental conditions: basal, watching a popular cartoon with audio (V-A), and with muted audio track (VwA). For short-range connections, basal records, statistical significant correlations were found for all EEG bands in the left hemisphere, but no significant correlations were found for fast EEG frequencies in the right hemisphere. For the V-A condition, significant correlations were mainly diminished for the left hemisphere; for the right hemisphere, no significant correlations were found for the fast EEG frequency bands. For the VwA condition, significant correlations for the rapid EEG frequencies mainly disappeared for the right hemisphere. For long-range connections, basal records showed similar correlations for both hemispheres. For the right hemisphere, significant correlations incremented to all EEG bands for the V-A condition, but these significant correlations disappeared for the fast EEG frequencies in the VwA condition. It appears that in a resting-state condition, AC is better associated with functional connectivity for short-range connections in the left hemisphere. The V-A experimental condition enriches the AC and FC association for long-range connections in the right hemisphere. This might be related to an effective connectivity improvement due to full video stimulation (visual and auditory). An impaired audiovisual interaction in the right hemisphere might explain why significant correlations disappeared for the fast EEG frequencies in the VwA experimental condition.

  15. Evaluation of iris functional capillary density in experimental local and systemic inflammation.

    PubMed

    Arora, N; Islam, S; Wafa, K; Zhou, J; Toguri, J T; Cerny, V; Lehmann, C

    2017-04-01

    The ocular microcirculation represents an important target to treat inflammatory diseases of eye, where impairment of microvascular blood flow plays key role as, for example, in anterior uveitis. To evaluate novel interventions targeting the microcirculation, appropriate and reliable tools to study this particular microvascular bed are needed. Intravital microscopy (IVM) belongs to several methods allowing evaluation of microcirculation experimentally, even in small animals. The aim of our study was to examine the iridial microcirculation (IMIC) in uveitis induced by local or systemic endotoxin administration in rats and mice by IVM and to propose new parameters to quantify the changes within the IMIC. Systemic inflammation was induced in rats by intravenous endotoxin administration, control group received normal saline intravenously. Local inflammation was induced in mice by intravitreal endotoxin administration, the control group received normal saline intravitreally. IVM of IMIC was performed in animals receiving systemic endotoxin prior injection and 1 and 2 h afterwards, respectively, in animals receiving intravitreal endotoxin/saline prior local injection and 5 h afterwards. Obtained video recordings were analyzed off-line. Functional capillary density (FCD) and dysfunctional capillary density (DCD) were evaluated for description of IMIC, and calculation of FCD/DCD ratio was performed. In systemic inflammation, FCD was significantly decreased compared to control animals. In local inflammation, the number of functional capillaries in the IMIC was significantly reduced following the endotoxin challenge. Analysis of the DCD revealed a significant increase in capillaries with reduced perfusion after intravitreal endotoxin administration and right shift of the FCD/DCD ratio was observed after endotoxin local injection. Detecting and quantifying changes in IMIC during systemic or local inflammation in experimental animals by IVM was feasible. Therefore, IVM of the

  16. Notch signalling suppresses regulatory T-cell function in murine experimental autoimmune uveitis.

    PubMed

    Rong, Hua; Shen, Hongjie; Xu, Yueli; Yang, Hai

    2016-12-01

    Autoimmune uveitis is an intraocular inflammatory disorder in developed countries. Understanding the mechanisms underlying the development and modulation of immune reaction in uveitic eyes is critical for designing therapeutic interventions. Here we investigated the role of Notch signalling in regulatory T-cell (Treg cell) function during experimental autoimmune uveitis (EAU). Using the Foxp3-GFP reporter mouse strain, the significance of Notch signalling for the function of infiltrating Treg cells was characterized in an EAU model. We found that infiltrating Treg cells substantially expressed Notch-1, Notch-2, JAG1 and DLL1 in uveitic eyes. Activation of Notch signalling, represented by expression of HES1 and HES5, was enhanced in infiltrating Treg cells. Treatment with JAG1 and DLL1 down-regulated Foxp3 expression and immunosuppressive activity of isolated infiltrating Treg cells in vitro, whereas neutralizing antibodies against JAG1 and DLL1 diminished Notch ligand-mediated negative effects on Treg cells. To investigate the significance of Notch signalling for Treg cell function in vivo, lentivirus-derived Notch short hairpin RNAs were transduced into in vitro expanded Treg cells before adoptive transfer of Treg cells into EAU mice. Transfer of Notch-1-deficient Treg cells remarkably reduced pro-inflammatory cytokine production and inflammatory cell infiltration in uveitic eyes. Taken together, Notch signalling negatively modulates the immunosuppressive function of infiltrating Treg cells in mouse EAU.

  17. Admissions for isolated nonoperative mild head injuries: Sharing the burden among trauma surgery, neurosurgery, and neurology.

    PubMed

    Zhao, Ting; Mejaddam, Ali Y; Chang, Yuchiao; DeMoya, Marc A; King, David R; Yeh, Daniel D; Kaafarani, Haytham M A; Alam, Hasan B; Velmahos, George C

    2016-10-01

    Isolated nonoperative mild head injuries (INOMHI) occur with increasing frequency in an aging population. These patients often have multiple social, discharge, and rehabilitation issues, which far exceed the acute component of their care. This study was aimed to compare the outcomes of patients with INOMHI admitted to three services: trauma surgery, neurosurgery, and neurology. Retrospective case series (January 1, 2009 to August 31, 2013) at an academic Level I trauma center. According to an institutional protocol, INOMHI patients with Glasgow Coma Scale (GCS) of 13 to 15 were admitted on a weekly rotational basis to trauma surgery, neurosurgery, and neurology. The three populations were compared, and the primary outcomes were survival rate to discharge, neurological status at hospital discharge as measured by the Glasgow Outcome Score (GOS), and discharge disposition. Four hundred eighty-eight INOMHI patients were admitted (trauma surgery, 172; neurosurgery, 131; neurology, 185). The mean age of the study population was 65.3 years, and 58.8% of patients were male. Seventy-seven percent of patients has a GCS score of 15. Age, sex, mechanism of injury, Charlson Comorbidity Index, Injury Severity Score, Abbreviated Injury Scale in head and neck, and GCS were similar among the three groups. Patients who were admitted to trauma surgery, neurosurgery and neurology services had similar proportions of survivors (98.8% vs 95.7% vs 94.7%), and discharge disposition (home, 57.0% vs 61.6% vs 55.7%). The proportion of patients with GOS of 4 or 5 on discharge was slightly higher among patients admitted to trauma (97.7% vs 93.0% vs 92.4%). In a logistic regression model adjusting for Charlson Comorbidity Index CCI and Abbreviated Injury Scale head and neck scores, patients who were admitted to neurology or neurosurgery had significantly lower odds being discharged with GOS 4 or 5. While the trauma group had the lowest proportion of repeats of brain computed tomography (61

  18. Functional Magnetic Resonance Imaging of Rats with Experimental Autoimmune Encephalomyelitis Reveals Brain Cortex Remodeling

    PubMed Central

    Tambalo, Stefano; Peruzzotti-Jametti, Luca; Rigolio, Roberta; Fiorini, Silvia; Bontempi, Pietro; Mallucci, Giulia; Balzarotti, Beatrice; Marmiroli, Paola; Sbarbati, Andrea; Cavaletti, Guido

    2015-01-01

    Cortical reorganization occurring in multiple sclerosis (MS) patients is thought to play a key role in limiting the effect of structural tissue damage. Conversely, its exhaustion may contribute to the irreversible disability that accumulates with disease progression. Several aspects of MS-related cortical reorganization, including the overall functional effect and likely modulation by therapies, still remain to be elucidated. The aim of this work was to assess the extent of functional cortical reorganization and its brain structural/pathological correlates in Dark Agouti rats with experimental autoimmune encephalomyelitis (EAE), a widely accepted preclinical model of chronic MS. Morphological and functional MRI (fMRI) were performed before disease induction and during the relapsing and chronic phases of EAE. During somatosensory stimulation of the right forepaw, fMRI demonstrated that cortical reorganization occurs in both relapsing and chronic phases of EAE with increased activated volume and decreased laterality index versus baseline values. Voxel-based morphometry demonstrated gray matter (GM) atrophy in the cerebral cortex, and both GM and white matter atrophy were assessed by ex vivo pathology of the sensorimotor cortex and corpus callosum. Neuroinflammation persisted in the relapsing and chronic phases, with dendritic spine density in the layer IV sensory neurons inversely correlating with the number of cluster of differentiation 45-positive inflammatory lesions. Our work provides an innovative experimental platform that may be pivotal for the comprehension of key mechanisms responsible for the accumulation of irreversible brain damage and for the development of innovative therapies to reduce disability in EAE/MS. SIGNIFICANCE STATEMENT Since the early 2000s, functional MRI (fMRI) has demonstrated profound modifications in the recruitment of cortical areas during motor, cognitive, and sensory tasks in multiple sclerosis (MS) patients. Experimental autoimmune

  19. An experimental study of executive function and social impairment in Cornelia de Lange syndrome.

    PubMed

    Nelson, Lisa; Crawford, Hayley; Reid, Donna; Moss, Joanna; Oliver, Chris

    2017-09-11

    Extreme shyness and social anxiety is reported to be characteristic of adolescents and adults with Cornelia de Lange syndrome (CdLS); however, the nature of these characteristics is not well documented. In this study, we develop and apply an experimental assessment of social anxiety in a group of adolescents and adults with CdLS to determine the nature of the social difficulties and whether they are related to impairments in executive functioning. A familiar and unfamiliar examiner separately engaged in socially demanding tasks comprising three experimental conditions with a group of individuals with CdLS (n = 25; % male = 44; mean age = 22.16; SD = 8.81) and a comparable group of individuals with Down syndrome (DS; n = 20; % male = 35; mean age = 24.35; SD = 5.97). Behaviours indicative of social anxiety were coded. The Behavior Rating Inventory of Executive Function-Preschool version, an informant measure of executive function, was completed by participants' caregivers. Significantly less verbalisation was observed in the CdLS group than the DS group in conditions requiring the initiation of speech. In the CdLS group, impairments in verbalisation were not associated with a greater degree of intellectual disability but were significantly correlated with impairments in both planning and working memory. This association was not evident in the DS group. Adolescents and adults with CdLS have a specific difficulty with the initiation of speech when social demands are placed upon them. This impairment in verbalisation may be underpinned by specific cognitive deficits, although further research is needed to investigate this fully.

  20. Acidity of the amidoxime functional group in aqueous solution. A combined experimental and computational study

    SciTech Connect

    Mehio, Nada; Lashely, Mark A.; Nugent, Joseph W.; Tucker, Lyndsay; Correia, Bruna; Do-Thanh, Chi-Linh; Dai, Sheng; Hancock, Robert D.; Bryantsev, Vyacheslav S.

    2015-01-26

    Poly(acrylamidoxime) adsorbents are often invoked in discussions of mining uranium from seawater. It has been demonstrated repeatedly in the literature that the success of these materials is due to the amidoxime functional group. While the amidoxime-uranyl chelation mode has been established, a number of essential binding constants remain unclear. This is largely due to the wide range of conflicting pKa values that have been reported for the amidoxime functional group in the literature. To resolve this existing controversy we investigated the pKa values of the amidoxime functional group using a combination of experimental and computational methods. Experimentally, we used spectroscopic titrations to measure the pKa values of representative amidoximes, acetamidoxime and benzamidoxime. Computationally, we report on the performance of several protocols for predicting the pKa values of aqueous oxoacids. Calculations carried out at the MP2 or M06-2X levels of theory combined with solvent effects calculated using the SMD model provide the best overall performance with a mean absolute error of 0.33 pKa units and 0.35 pKa units, respectively, and a root mean square deviation of 0.46 pKa units and 0.45 pKa units, respectively. Finally, we employ our two best methods to predict the pKa values of promising, uncharacterized amidoxime ligands. Hence, our study provides a convenient means for screening suitable amidoxime monomers for future generations of poly(acrylamidoxime) adsorbents used to mine uranium from seawater.

  1. Acidity of the amidoxime functional group in aqueous solution. A combined experimental and computational study

    DOE PAGES

    Mehio, Nada; Lashely, Mark A.; Nugent, Joseph W.; ...

    2015-01-26

    Poly(acrylamidoxime) adsorbents are often invoked in discussions of mining uranium from seawater. It has been demonstrated repeatedly in the literature that the success of these materials is due to the amidoxime functional group. While the amidoxime-uranyl chelation mode has been established, a number of essential binding constants remain unclear. This is largely due to the wide range of conflicting pKa values that have been reported for the amidoxime functional group in the literature. To resolve this existing controversy we investigated the pKa values of the amidoxime functional group using a combination of experimental and computational methods. Experimentally, we used spectroscopicmore » titrations to measure the pKa values of representative amidoximes, acetamidoxime and benzamidoxime. Computationally, we report on the performance of several protocols for predicting the pKa values of aqueous oxoacids. Calculations carried out at the MP2 or M06-2X levels of theory combined with solvent effects calculated using the SMD model provide the best overall performance with a mean absolute error of 0.33 pKa units and 0.35 pKa units, respectively, and a root mean square deviation of 0.46 pKa units and 0.45 pKa units, respectively. Finally, we employ our two best methods to predict the pKa values of promising, uncharacterized amidoxime ligands. Hence, our study provides a convenient means for screening suitable amidoxime monomers for future generations of poly(acrylamidoxime) adsorbents used to mine uranium from seawater.« less

  2. Annulus fibrosus functional extrafibrillar and fibrous mechanical behaviour: experimental and computational characterisation

    PubMed Central

    Kayode, Oluwasegun; Sikora, Sebastien N. F.; Zapata-Cornelio, Fernando Y.; Gregory, Diane E.; Wilcox, Ruth K.

    2017-01-01

    The development of current surgical treatments for intervertebral disc damage could benefit from virtual environment accounting for population variations. For such models to be reliable, a relevant description of the mechanical properties of the different tissues and their role in the functional mechanics of the disc is of major importance. The aims of this work were first to assess the physiological hoop strain in the annulus fibrosus in fresh conditions (n = 5) in order to extract a functional behaviour of the extrafibrillar matrix; then to reverse-engineer the annulus fibrosus fibrillar behaviour (n = 6). This was achieved by performing both direct and global controlled calibration of material parameters, accounting for the whole process of experimental design and in silico model methodology. Direct-controlled models are specimen-specific models representing controlled experimental conditions that can be replicated and directly comparing measurements. Validation was performed on another six specimens and a sensitivity study was performed. Hoop strains were measured as 17 ± 3% after 10 min relaxation and 21 ± 4% after 20–25 min relaxation, with no significant difference between the two measurements. The extrafibrillar matrix functional moduli were measured as 1.5 ± 0.7 MPa. Fibre-related material parameters showed large variability, with a variance above 0.28. Direct-controlled calibration and validation provides confidence that the model development methodology can capture the measurable variation within the population of tested specimens. PMID:28879014

  3. Annulus fibrosus functional extrafibrillar and fibrous mechanical behaviour: experimental and computational characterisation.

    PubMed

    Mengoni, Marlène; Kayode, Oluwasegun; Sikora, Sebastien N F; Zapata-Cornelio, Fernando Y; Gregory, Diane E; Wilcox, Ruth K

    2017-08-01

    The development of current surgical treatments for intervertebral disc damage could benefit from virtual environment accounting for population variations. For such models to be reliable, a relevant description of the mechanical properties of the different tissues and their role in the functional mechanics of the disc is of major importance. The aims of this work were first to assess the physiological hoop strain in the annulus fibrosus in fresh conditions (n = 5) in order to extract a functional behaviour of the extrafibrillar matrix; then to reverse-engineer the annulus fibrosus fibrillar behaviour (n = 6). This was achieved by performing both direct and global controlled calibration of material parameters, accounting for the whole process of experimental design and in silico model methodology. Direct-controlled models are specimen-specific models representing controlled experimental conditions that can be replicated and directly comparing measurements. Validation was performed on another six specimens and a sensitivity study was performed. Hoop strains were measured as 17 ± 3% after 10 min relaxation and 21 ± 4% after 20-25 min relaxation, with no significant difference between the two measurements. The extrafibrillar matrix functional moduli were measured as 1.5 ± 0.7 MPa. Fibre-related material parameters showed large variability, with a variance above 0.28. Direct-controlled calibration and validation provides confidence that the model development methodology can capture the measurable variation within the population of tested specimens.

  4. Experimental hyperleptinemia in neonatal rats leads to selective leptin responsiveness, hypertension, and altered myocardial function.

    PubMed

    Samuelsson, Anne-Maj; Clark, James; Rudyk, Olena; Shattock, Michael J; Bae, Sung Eun; South, Timothy; Pombo, Joaquim; Redington, Kathrine; Uppal, Esna; Coen, Clive W; Poston, Lucilla; Taylor, Paul D

    2013-09-01

    The prevalence of obesity among pregnant women is increasing. Evidence from human cohort studies and experimental animals suggests that offspring cardiovascular and metabolic function is compromised through early life exposure to maternal obesity. Previously, we reported that juvenile offspring of obese rats develop sympathetically mediated hypertension associated with neonatal hyperleptinemia. We have now addressed the hypothesis that neonatal exposure to raised leptin in the immediate postnatal period plays a causal role. Pups from lean Sprague-Dawley rats were treated either with leptin (3 mg/kg IP) or with saline twice daily from postnatal day 9 to 15 to mimic the exaggerated postnatal leptin surge observed in offspring of obese dams. Cardiovascular function was assessed by radiotelemetry at 30 days, and 2 and 12 months. In juvenile (30 days) leptin-treated rats, hearts were heavier and night-time (active period) systolic blood pressure was raised (mm Hg; mean ± SEM: male leptin-treated, 132 ± 1 versus saline-treated, 119 ± 1, n=6, P<0.05; female leptin-treated, 132 ± 2 versus saline-treated, 119 ± 1, n=6, P<0.01), and the pressor response to restraint stress and leptin challenge increased compared with saline-treated rats. Heart rate variability demonstrated an increased low:high frequency ratio in 30-day leptin-treated animals, indicative of heightened sympathetic efferent tone. Echocardiography showed altered left ventricular structure and systolic function in 30-day female leptin versus saline-treated rats. These disorders persisted to adulthood. In isolated hearts, contractile function was impaired at 5 months in male leptin-treated rats. Exogenously imposed hyperleptinemia in neonatal rats permanently influences blood pressure and cardiac structure and function.

  5. Investment in constitutive immune function by North American elk experimentally maintained at two different population densities.

    PubMed

    Downs, Cynthia J; Stewart, Kelley M; Dick, Brian L

    2015-01-01

    Natural selection favors individuals that respond with effective and appropriate immune responses to macro or microparasites. Animals living in populations close to ecological carrying capacity experience increased intraspecific competition, and as a result are often in poor nutritional condition. Nutritional condition, in turn, affects the amount of endogenous resources that are available for investment in immune function. Our objective was to understand the relationship between immune function and density dependence mediated by trade-offs between immune function, nutritional condition, and reproduction. To determine how immune function relates to density-dependent processes, we quantified bacteria killing ability, hemolytic-complement activity, and nutritional condition of North American elk (Cervus elaphus) from populations maintained at experimentally high- and low-population densities. When compared with elk from the low-density population, those from the high-density population had higher bacteria killing ability and hemolytic-complement activity despite their lower nutritional condition. Similarly, when compared with adults, yearlings had higher bacteria killing ability, higher hemolytic-complement activity, and lower nutritional condition. Pregnancy status and lactational status did not change either measure of constitutive immunity. Density-dependent processes affected both nutritional condition and investment in constitutive immune function. Although the mechanism for how density affects immunity is ambiguous, we hypothesize two possibilities: (i) individuals in higher population densities and in poorer nutritional condition invested more into constitutive immune defenses, or (ii) had higher parasite loads causing higher induced immune responses. Those explanations are not mutually exclusive, and might be synergistic, but overall our results provide stronger support for the hypothesis that animals in poorer nutritional condition invest more in

  6. Investment in Constitutive Immune Function by North American Elk Experimentally Maintained at Two Different Population Densities

    PubMed Central

    Downs, Cynthia J.; Stewart, Kelley M.; Dick, Brian L.

    2015-01-01

    Natural selection favors individuals that respond with effective and appropriate immune responses to macro or microparasites. Animals living in populations close to ecological carrying capacity experience increased intraspecific competition, and as a result are often in poor nutritional condition. Nutritional condition, in turn, affects the amount of endogenous resources that are available for investment in immune function. Our objective was to understand the relationship between immune function and density dependence mediated by trade-offs between immune function, nutritional condition, and reproduction. To determine how immune function relates to density-dependent processes, we quantified bacteria killing ability, hemolytic-complement activity, and nutritional condition of North American elk (Cervus elaphus) from populations maintained at experimentally high- and low-population densities. When compared with elk from the low-density population, those from the high-density population had higher bacteria killing ability and hemolytic-complement activity despite their lower nutritional condition. Similarly, when compared with adults, yearlings had higher bacteria killing ability, higher hemolytic-complement activity, and lower nutritional condition. Pregnancy status and lactational status did not change either measure of constitutive immunity. Density-dependent processes affected both nutritional condition and investment in constitutive immune function. Although the mechanism for how density affects immunity is ambiguous, we hypothesize two possibilities: (i) individuals in higher population densities and in poorer nutritional condition invested more into constitutive immune defenses, or (ii) had higher parasite loads causing higher induced immune responses. Those explanations are not mutually exclusive, and might be synergistic, but overall our results provide stronger support for the hypothesis that animals in poorer nutritional condition invest more in

  7. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust.

    PubMed

    Rudell, B; Ledin, M C; Hammarström, U; Stjernberg, N; Lundbäck, B; Sandström, T

    1996-10-01

    Diesel exhaust is a common air pollutant made up of several gases, hydrocarbons, and particles. An experimental study was carried out which was designed to evaluate if a particle trap on the tail pipe of an idling diesel engine would reduce effects on symptoms and lung function caused by the diesel exhaust, compared with exposure to unfiltered exhaust. Twelve healthy non-smoking volunteers (aged 20-37) were investigated in an exposure chamber for one hour during light work on a bicycle ergometer at 75 W. Each subject underwent three separate double blind exposures in a randomised sequence: to air and to diesel exhaust with the particle trap at the tail pipe and to unfiltered diesel exhaust. Symptoms were recorded according to the Borg scale before, every 10 minutes during, and 30 minutes after the exposure. Lung function was measured with a computerised whole body plethysmograph. The ceramic wall flow particle trap reduced the number of particles by 46%, whereas other compounds were relatively constant. It was shown that the most prominent symptoms during exposure to diesel exhaust were irritation of the eyes and nose and an unpleasant smell increasing during exposure. Both airway resistance (R(aw)) and specific airway resistance (SR(aw)) increased significantly during the exposures to diesel exhaust. Despite the 46% reduction in particle numbers by the trap effects on symptoms and lung function were not significantly attenuated. Exposure to diesel exhaust caused symptoms and bronchoconstriction which were not significantly reduced by a particle trap.

  8. An Experimental Investigation of the Functional Hypothesis and Evolutionary Advantage of Stone-Tipped Spears

    PubMed Central

    Wilkins, Jayne; Schoville, Benjamin J.; Brown, Kyle S.

    2014-01-01

    Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative ‘stopping power’ or ‘killing power’ of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history. PMID:25162397

  9. Transition from wind pollination to insect pollination in sedges: experimental evidence and functional traits.

    PubMed

    Wragg, Peter D; Johnson, Steven D

    2011-09-01

    Transitions from wind pollination to insect pollination were pivotal to the radiation of land plants, yet only a handful are known and the trait shifts required are poorly understood. We tested the hypothesis that a transition to insect pollination took place in the ancestrally wind-pollinated sedges (Cyperaceae) and that floral traits modified during this transition have functional significance. We paired putatively insect-pollinated Cyperus obtusiflorus and Cyperus sphaerocephalus with related, co-flowering, co-occurring wind-pollinated species, and compared pairs in terms of pollination mode and functional roles of floral traits. Experimentally excluding insects reduced seed set by 56-89% in putatively insect-pollinated species but not in intermingled wind-pollinated species. The pollen of putatively insect-pollinated species was less motile in a wind tunnel than that of wind-pollinated species. Bees, beetles and flies preferred inflorescences, and color-matched white or yellow models, of putatively insect-pollinated species over inflorescences, or color-matched brown models, of wind-pollinated species. Floral scents of putatively insect-pollinated species were chemically consistent with those of other insect-pollinated plants, and attracted pollinators; wind-pollinated species were unscented. These results show that a transition from wind pollination to insect pollination occurred in sedges and shed new light on the function of traits involved in this important transition.

  10. Experimental models for the study of female and male sexual function.

    PubMed

    Giuliano, Francois; Pfaus, James; Srilatha, Balasubramanian; Balasubramanian, Srilatha; Hedlund, Petter; Hisasue, Shin-ichi; Marson, Lesley; Wallen, Kim

    2010-09-01

    Significant progress has been made in the understanding of physiological and pharmacological mechanisms of human sexual functioning through preclinical research in animal models. To provide an evidence-based documentation of the experimental models evaluating male and female sexual function for useful clinical translation. Consensus discussion over the past 18 months leading to summarized views of seven experts from six countries. Report was based on the critical analysis of scientific information available in literature and subcommittee presentations, discussions, and exchanges of ideas and feedback. Fundamental research in animal models has led to considerable understanding of the physiological mechanisms underlying desire, arousal, genital, and other sexual responses and the design of rational pharmacological treatments for certain sexual dysfunctions in the male and female. Tissue and cellular in vitro systems have provided critical information on the in vivo interactions and modulations in the presence and absence of chemical, biological, vascular, neurologic, endocrine, and genetic inputs. The animal models seem indispensable for elucidating the biophysiological and etiopathological aspects of male and female sexual disorders. Useful insights into the human experience have been derived from basic research in ways that are far more difficult to obtain in humans, both scientifically and ethically. The animal model with a good predictive value can be used as a successful preclinical tool so long as the functional end points are homologous or analogous. The key issue is whether further evaluations are warranted to extrapolate the results in a clinical setting. © 2010 International Society for Sexual Medicine.

  11. An experimental investigation of the functional hypothesis and evolutionary advantage of stone-tipped spears.

    PubMed

    Wilkins, Jayne; Schoville, Benjamin J; Brown, Kyle S

    2014-01-01

    Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative 'stopping power' or 'killing power' of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history.

  12. Experimental Energy Levels and Partition Function of the 12C2 Molecule

    NASA Astrophysics Data System (ADS)

    Furtenbacher, Tibor; Szabó, István; Császár, Attila G.; Bernath, Peter F.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2016-06-01

    The carbon dimer, the 12C2 molecule, is ubiquitous in astronomical environments. Experimental-quality rovibronic energy levels are reported for 12C2, based on rovibronic transitions measured for and among its singlet, triplet, and quintet electronic states, reported in 42 publications. The determination utilizes the Measured Active Rotational-Vibrational Energy Levels (MARVEL) technique. The 23,343 transitions measured experimentally and validated within this study determine 5699 rovibronic energy levels, 1325, 4309, and 65 levels for the singlet, triplet, and quintet states investigated, respectively. The MARVEL analysis provides rovibronic energies for six singlet, six triplet, and two quintet electronic states. For example, the lowest measurable energy level of the {{a}}{}3{{{\\Pi }}}{{u}} state, corresponding to the J = 2 total angular momentum quantum number and the F 1 spin-multiplet component, is 603.817(5) cm-1. This well-determined energy difference should facilitate observations of singlet-triplet intercombination lines, which are thought to occur in the interstellar medium and comets. The large number of highly accurate and clearly labeled transitions that can be derived by combining MARVEL energy levels with computed temperature-dependent intensities should help a number of astrophysical observations as well as corresponding laboratory measurements. The experimental rovibronic energy levels, augmented, where needed, with ab initio variational ones based on empirically adjusted and spin-orbit coupled potential energy curves obtained using the Duo code, are used to obtain a highly accurate partition function, and related thermodynamic data, for 12C2 up to 4000 K.

  13. Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function

    SciTech Connect

    Tung, Ryan C. Killgore, Jason P.; Hurley, Donna C.

    2014-06-14

    We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.

  14. Experimental verification of modified synthetic discriminant function filters for rotation invariance

    NASA Technical Reports Server (NTRS)

    Reid, Max B.; Ma, Paul W.; Downie, John D.; Ochoa, Ellen

    1990-01-01

    Experimental results are presented which demonstrate that effective binary synthetic discriminant functions (SDFs) can be constructed if the binary nature of the filter modulation is included in SDF synthesis. It is also shown that the iterative procedure needed to produce the SDF is well performed on the optical correlator, as opposed to off-line computation. Binary SDF filters have been demonstrated which produce approximately equal correlation peaks over in-plane rotation ranges up to 75 deg and out-of-plane rotation ranges up to 60 deg. This technique, combined with the translational position invariance of optical filters, allows a single filter to track a Shuttle Orbiter as it moves along a curved path across the input field.

  15. Experimental verification of modified synthetic discriminant function filters for rotation invariance

    NASA Technical Reports Server (NTRS)

    Reid, Max B.; Ma, Paul W.; Downie, John D.; Ochoa, Ellen

    1990-01-01

    Experimental results are presented which demonstrate that effective binary synthetic discriminant functions (SDFs) can be constructed if the binary nature of the filter modulation is included in SDF synthesis. It is also shown that the iterative procedure needed to produce the SDF is well performed on the optical correlator, as opposed to off-line computation. Binary SDF filters have been demonstrated which produce approximately equal correlation peaks over in-plane rotation ranges up to 75 deg and out-of-plane rotation ranges up to 60 deg. This technique, combined with the translational position invariance of optical filters, allows a single filter to track a Shuttle Orbiter as it moves along a curved path across the input field.

  16. An experimental approach to study the function of mitochondria in cardiomyopathy

    PubMed Central

    Chung, Youn Wook; Kang, Seok-Min

    2015-01-01

    Cardiomyopathy is an inherited or acquired disease of the myocardium, which can result in severe ventricular dysfunction. Mitochondrial dysfunction is involved in the pathological process of cardiomyopathy. Many dysfunctions in cardiac mitochondria are consequences of mutations in nuclear or mitochondrial DNA followed by alterations in transcriptional regulation, mitochondrial protein function, and mitochondrial dynamics and energetics, presenting with associated multisystem mitochondrial disorders. To ensure correct diagnosis and optimal management of mitochondrial dysfunction in cardiomyopathy caused by multiple pathogenesis, multidisciplinary approaches are required, and to integrate between clinical and basic sciences, ideal translational models are needed. In this review, we will focus on experimental models to provide insights into basic mitochondrial physiology and detailed underlying mechanisms of cardiomyopathy and current mitochondria-targeted therapies for cardiomyopathy. [BMB Reports 2015; 48(10): 541-548] PMID:26198095

  17. Experimental Level Densities and {gamma}-Strength Functions in rare earth nuclei

    SciTech Connect

    Siem, S.; Guttormsen, M.; Larsen, A. C.; Nyhus, H. T.; Ingebretsen, F.; Messelt, S.; Rekstad, J.; Syed, N. U. H.; Chankova, R.; Schiller, A.; Voinov, A.; Oedegaard, S. W.

    2008-04-17

    The level density and radiative strength function for {sup 146,147}Sm and {sup 163,164}Dy have been extracted from primary {gamma} spectra using the Oslo method. As one approaches the closed N = 82 neutron shell, the structures in the level density become more pronounced due to shell effects. The experimental level densities can be used to explore thermodynamic properties of the nucleus within the microcanonical ensemble. Pygmy resonances, which are based on the scissors mode and seen in deformed rare-earth nuclei, are not observed in near-spherical {sup 146,147}Sm, as expected. Pygmy resonances in {sup 163,164}Dy were studied after {sup 3}He-induced reactions and their width was found to be twice as wide as compared to results reported after neutron-capture reactions.

  18. Reconstruction of Kelvin probe force microscopy image with experimentally calibrated point spread function

    NASA Astrophysics Data System (ADS)

    Lan, Fei; Jiang, Minlin; Tao, Quan; Wei, Fanan; Li, Guangyong

    2017-03-01

    A Kelvin probe force microscopy (KPFM) image is sometimes difficult to interpret because it is a blurred representation of the true surface potential (SP) distribution of the materials under test. The reason for the blurring is that KPFM relies on the detection of electrostatic force, which is a long-range force compared to other surface forces. Usually, KPFM imaging model is described as the convolution of the true SP distribution of the sample with an intrinsic point spread function (PSF) of the measurement system. To restore the true SP signals from the blurred ones, the intrinsic PSF of the system is needed. In this work, we present a way to experimentally calibrate the PSF of the KPFM system. Taking the actual probe shape and experimental parameters into consideration, this calibration method leads to a more accurate PSF than the ones obtained from simulations. Moreover, a nonlinear reconstruction algorithm based on total variation (TV) regularization is applied to KPFM measurement to reverse the blurring caused by PSF during KPFM imaging process; as a result, noises are reduced and the fidelity of SP signals is improved.

  19. Experimental determination of the response functions of a Bonner sphere spectrometer to monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Hu, Z.; Chen, Z.; Peng, X.; Du, T.; Cui, Z.; Ge, L.; Zhu, W.; Wang, Z.; Zhu, X.; Chen, J.; Zhang, G.; Li, X.; Chen, J.; Zhang, H.; Zhong, G.; Hu, L.; Wan, B.; Gorini, G.; Fan, T.

    2017-06-01

    A Bonner sphere spectrometer (BSS) plays an important role in characterizing neutron spectra and determining their neutron dose in a neutron-gamma mixed field. A BSS consisting of a set of nine polyethylene spheres with a 3He proportional counter was developed at Peking University to perform neutron spectrum and dosimetry measurements. Response functions (RFs) of the BSS were calculated with the general Monte Carlo code MCNP5 for the neutron energy range from thermal up to 20 MeV, and were experimentally calibrated with monoenergetic neutron beams from 144 keV to 14 MeV on a 4.5 MV Van de Graaff accelerator. The calculated RFs were corrected with the experimental values, and the whole response matrix was completely established. The spectrum of a 241Am-Be source was obtained after unfolding the measurement data of the BSS to the source and in fair agreement with the expected one. The integral ambient dose equivalent corresponding to the spectrum was 0.95 of the expected value. Results of the unfolded spectrum and the integral dose equivalent measured by the BSS verified that the RFs of the BSS were well established.

  20. What happens inside a fuel cell? Developing an experimental functional map of fuel cell performance.

    PubMed

    Brett, Daniel J L; Kucernak, Anthony R; Aguiar, Patricia; Atkins, Stephen C; Brandon, Nigel P; Clague, Ralph; Cohen, Lesley F; Hinds, Gareth; Kalyvas, Christos; Offer, Gregory J; Ladewig, Bradley; Maher, Robert; Marquis, Andrew; Shearing, Paul; Vasileiadis, Nikos; Vesovic, Velisa

    2010-09-10

    Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an 'experimental functional map' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models.

  1. Experimental Determination of the Electric Dipole Moment Function of the X Pi-2 Hydroxyl Radical

    NASA Technical Reports Server (NTRS)

    Chackerian, C., Jr.; Goorvitch, D.; Abrams, M. C.; Davis, S. P.; Benidar, A.; Farrenq, R.; Guelachvili, G.; Strawa, Anthony W. (Technical Monitor)

    1995-01-01

    Laboratory infrared emission spectra of X 2piOH obtained with the Solar McMath FTS and the U. Paris (Orsay) FTS are used in an inversion procedure to experimentally determine the electric dipole moment function (EDMF) of the hydroxyl radical. The spectra produced at Kitt Peak show vibrational levels up to v = 10 and rotational lines in the range, -25.5 less than or equal to m less than or equal to 12.5. The following vibrational quantum number ranges were observed: for DELTA v = -1, v prime = 1 - 9, for DELTA v = -2, v prime = 2 - 10, and for DELTA v = - 3, v prime = 6 - 10. The spectra produced at Orsay show DELTA v = -1, with v prime = 1 - 4 and -22.5 less than or equal to m less than or equal to 9.5 as well as DELTA v = 0, with v prime= 1 - 3, and 9.5 less than or equal to m less than or equal to 25.5. The OH rovibrational wavefunctions used in the inversion procedure were calculated using a procedure which reproduces observed rotational constants with a high level of accuracy. Comparisons of our EDMF are made with previous experimental and theoretical work.

  2. An experimental investigation of the functional relationship between social phobia and cigarette smoking.

    PubMed

    Dahne, Jennifer; Hise, Leanne; Brenner, Misha; Lejuez, C W; MacPherson, Laura

    2015-04-01

    Individuals with social phobia (SP) represent a large group with elevated rates of cigarette smoking and cessation rates lower than that of individuals without psychopathology. For individuals with SP, cigarette smoking may be used to reduce social anxiety in anticipation of and during social situations. However, no study to date has experimentally examined this association. The aim of the current study was to experimentally examine the relationship between cigarette smoking and SP as a function of induced social stress. We recruited daily smokers ages 18-21 who scored in either a clinical or normative range on the Social Interaction Anxiety Scale (SIAS). Participants included 54 smokers (42.6% female, 77.8% White, age M(SD)=19.65(1.18), CPSD M(SD)=7.67(4.36), 46.30% high SP) who attended two sessions: one social stress session and one neutral session. Results indicated that high SP smokers experienced significant decreases in negative affect (NA) following smoking a cigarette when experiencing social stress. This effect was specific to high SP smokers under social stress and was not observed among individuals' average in SP or when examining changes in positive affect. For individuals with SP, cigarette smoking may be maintained due to changes in NA associated with smoking specifically in the context of social stress. These results speak to the importance of targeted cessation interventions that address the nature of smoking for individuals with SP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. [The effect of sulodexide on placental mitochondria function in rats with experimental preeclampsia].

    PubMed

    Popova, T A; Perfilova, V N; Zhakupova, G A; Verovsky, V E; Ostrovskij, O V; Tyurenkov, I N

    2016-07-01

    Substitution of drinking water for 1.8% NaCl in pregnant rats caused a pronounced increase in arterial pressure by 24,3% and urinary protein by 117% to day 21 of pregnancy. State 4 respiration of isolated placental mitochondria in the group of negative control was 3- and 1.5-fold higher with malate/glutamate and succinate as substrates than in placental mitochondria isolated from uncomplicated pregnant animals. This led to a decrease of the respiratory control ratio. These results suggest that development of experimental preeclampsia is accompanied by mitochondrial dysfunction through uncoupling of oxidative phosphorylation. Daily administration of sulodexide to females with experimental preeclampsia (EP) per os at a dose of 30 LE during the whole period of gestation decreased manifestations of the disease as evidenced by a slight increase in blood pressure (by 8,6%) and less pronounces increase in urinary protein (by 58,9%). Sulodexide decreased development of mitochondrial dysfunction in EP rats as shown a decrease of non-stimulated ADP respiration with malate/glutamate and succinate (4.5- and 2.5-fold, respectively) as compared with the negative control group and the corresponding increase in the respiratory control ratio (2.5- and 1.5-fold, respectively). Thus, sulodexide reduces uncoupling of oxidative phosphorylation and enhances the functional activity of mitochondria in EP animals, possibly due to its antioxidant and endotelioprotective effects.

  4. Kinetic energies to analyze the experimental auger electron spectra by density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Endo, Kazunaka

    2016-02-01

    In the Auger electron spectra (AES) simulations, we define theoretical modified kinetic energies of AES in the density functional theory (DFT) calculations. The modified kinetic energies correspond to two final-state holes at the ground state and at the transition-state in DFT calculations, respectively. This method is applied to simulate Auger electron spectra (AES) of 2nd periodic atom (Li, Be, B, C, N, O, F)-involving substances (LiF, beryllium, boron, graphite, GaN, SiO2, PTFE) by deMon DFT calculations using the model molecules of the unit cell. Experimental KVV (valence band electrons can fill K-shell core holes or be emitted during KVV-type transitions) AES of the (Li, O) atoms in the substances agree considerably well with simulation of AES obtained with the maximum kinetic energies of the atoms, while, for AES of LiF, and PTFE substance, the experimental F KVV AES is almost in accordance with the spectra from the transitionstate kinetic energy calculations.

  5. Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

    PubMed Central

    Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

    2012-01-01

    AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). CONCLUSION: L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

  6. Tiny giants of gene regulation: experimental strategies for microRNA functional studies

    PubMed Central

    Steinkraus, Bruno R.; Toegel, Markus

    2016-01-01

    The discovery over two decades ago of short regulatory microRNAs (miRNAs) has led to the inception of a vast biomedical research field dedicated to understanding these powerful orchestrators of gene expression. Here we aim to provide a comprehensive overview of the methods and techniques underpinning the experimental pipeline employed for exploratory miRNA studies in animals. Some of the greatest challenges in this field have been uncovering the identity of miRNA–target interactions and deciphering their significance with regard to particular physiological or pathological processes. These endeavors relied almost exclusively on the development of powerful research tools encompassing novel bioinformatics pipelines, high‐throughput target identification platforms, and functional target validation methodologies. Thus, in an unparalleled manner, the biomedical technology revolution unceasingly enhanced and refined our ability to dissect miRNA regulatory networks and understand their roles in vivo in the context of cells and organisms. Recurring motifs of target recognition have led to the creation of a large number of multifactorial bioinformatics analysis platforms, which have proved instrumental in guiding experimental miRNA studies. Subsequently, the need for discovery of miRNA–target binding events in vivo drove the emergence of a slew of high‐throughput multiplex strategies, which now provide a viable prospect for elucidating genome‐wide miRNA–target binding maps in a variety of cell types and tissues. Finally, deciphering the functional relevance of miRNA post‐transcriptional gene silencing under physiological conditions, prompted the evolution of a host of technologies enabling systemic manipulation of miRNA homeostasis as well as high‐precision interference with their direct, endogenous targets. WIREs Dev Biol 2016, 5:311–362. doi: 10.1002/wdev.223 For further resources related to this article, please visit the WIREs website. PMID:26950183

  7. Dietary sodium modulation of aldosterone activation and renal function during the progression of experimental heart failure.

    PubMed

    Miller, Wayne L; Borgeson, Daniel D; Grantham, J Aaron; Luchner, Andreas; Redfield, Margaret M; Burnett, John C

    2015-02-01

    Aldosterone activation is central to the sodium–fluid retention that marks the progression of heart failure (HF). The actions of dietary sodium restriction, a mainstay in HF management, on cardiorenal and neuroendocrine adaptations during the progression of HF are poorly understood. The study aim was to assess the role of dietary sodium during the progression of experimental HF. Experimental HF was produced in a canine model by rapid right ventricular pacing which evolves from early mild HF to overt, severe HF. Dogs were fed one of three diets: (i) high sodium [250 mEq (5.8 g) per day, n =6]; (ii) standard sodium [58 mEq (1.3 g) per day, n =6]; and (iii) sodium restriction [11 mEq (0.25 g) per day, n =6]. During the 38-day study, haemodynamics, renal function, plasma renin activity (PRA), and aldosterone were measured. Changes in haemodynamics at 38 days were similar in all three groups, as were changes in renal function. Aldosterone activation was demonstrated in all three groups; however, dietary sodium restriction, in contrast to high sodium, resulted in early (10 days) activation of PRA and aldosterone. High sodium demonstrated significant suppression of aldosterone activation over the course of HF progression. Excessive dietary sodium restriction particularly in early stage HF results in early aldosterone activation, while normal and excess sodium intake are associated with delayed or suppressed activation. These findings warrant evaluation in humans to determine if dietary sodium manipulation, particularly during early stage HF, may have a significant impact on neuroendocrine disease progression.

  8. Three-dimensional multimodal image-guidance for neurosurgery

    SciTech Connect

    Peters, T.; Munger, P.; Comeau, R.; Evans, A.; Olivier, A.; Davey, B.

    1996-04-01

    The authors address the use of multimodality imaging as an aid to the planning and guidance of neurosurgical procedures, and discuss the integration of anatomical (CT and MRI), vascular (DSA), and functional (PET) data for presentation to the surgeon during surgery. The workstation is an enhancement of a commercially available system, and in addition to the guidance offered via a hand-held probe, it incorporates the use of multimodality imaging and adds enhanced realism to the surgeon through the use of a stereoscopic three-dimensional (3-D) image display. The probe may be visualized stereoscopically in single or multimodality images. The integration of multimodality data in this manner provides the surgeon with a complete overview of brain structures on which he is performing surgery, or through which he is passing probes or cannulas, enabling him to avoid critical vessels and/or structures of functional significance.

  9. Connectome analysis for pre-operative brain mapping in neurosurgery

    PubMed Central

    Hart, Michael G.; Price, Stephen J.; Suckling, John

    2016-01-01

    Abstract Object: Brain mapping has entered a new era focusing on complex network connectivity. Central to this is the search for the connectome or the brains ‘wiring diagram’. Graph theory analysis of the connectome allows understanding of the importance of regions to network function, and the consequences of their impairment or excision. Our goal was to apply connectome analysis in patients with brain tumours to characterise overall network topology and individual patterns of connectivity alterations. Methods: Resting-state functional MRI data were acquired using multi-echo, echo planar imaging pre-operatively from five participants each with a right temporal–parietal–occipital glioblastoma. Complex networks analysis was initiated by parcellating the brain into anatomically regions amongst which connections were identified by retaining the most significant correlations between the respective wavelet decomposed time-series. Results: Key characteristics of complex networks described in healthy controls were preserved in these patients, including ubiquitous small world organization. An exponentially truncated power law fit to the degree distribution predicted findings of general network robustness to injury but with a core of hubs exhibiting disproportionate vulnerability. Tumours produced a consistent reduction in local and long-range connectivity with distinct patterns of connection loss depending on lesion location. Conclusions: Connectome analysis is a feasible and novel approach to brain mapping in individual patients with brain tumours. Applications to pre-surgical planning include identifying regions critical to network function that should be preserved and visualising connections at risk from tumour resection. In the future one could use such data to model functional plasticity and recovery of cognitive deficits. PMID:27447756

  10. Understanding Brain, Mind and Soul: Contributions from Neurology and Neurosurgery

    PubMed Central

    Pandya, Sunil K.

    2011-01-01

    Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca’s area or the movement of limbs to the contralateral motor cortex. Galen’s localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units–neurones–lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of ‘the cocktail of brain soup and spark’ in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here. PMID:21694966

  11. Understanding brain, mind and soul: contributions from neurology and neurosurgery.

    PubMed

    Pandya, Sunil K

    2011-01-01

    Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca's area or the movement of limbs to the contralateral motor cortex. Galen's localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units-neurones-lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of 'the cocktail of brain soup and spark' in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here.

  12. GOsummaries: an R Package for Visual Functional Annotation of Experimental Data.

    PubMed

    Kolde, Raivo; Vilo, Jaak

    2015-01-01

    Functional characterisation of gene lists using Gene Ontology (GO) enrichment analysis is a common approach in computational biology, since many analysis methods end up with a list of genes as a result. Often there can be hundreds of functional terms that are significantly associated with a single list of genes and proper interpretation of such results can be a challenging endeavour. There are methods to visualise and aid the interpretation of these results, but most of them are limited to the results associated with one list of genes. However, in practice the number of gene lists can be considerably higher and common tools are not effective in such situations. We introduce a novel R package, 'GOsummaries' that visualises the GO enrichment results as concise word clouds that can be combined together if the number of gene lists is larger. By also adding the graphs of corresponding raw experimental data, GOsummaries can create informative summary plots for various analyses such as differential expression or clustering. The case studies show that the GOsummaries plots allow rapid functional characterisation of complex sets of gene lists. The GOsummaries approach is particularly effective for Principal Component Analysis (PCA). By adding functional annotation to the principal components, GOsummaries improves  significantly the interpretability of PCA results. The GOsummaries layout for PCA can be effective even in situations where we cannot directly apply the GO analysis. For example, in case of metabolomics or metagenomics data it is possible to show the features with significant associations to the components instead of GO terms.   The GOsummaries package is available under GPL-2 licence at Bioconductor (http://www.bioconductor.org/packages/release/bioc/html/GOsummaries.html).

  13. The relationship between microbial community structure and functional stability, tested experimentally in an upland pasture soil.

    PubMed

    Griffiths, B S; Kuan, H L; Ritz, K; Glover, L A; McCaig, A E; Fenwick, C

    2004-01-01

    Soil collected from an upland pasture was manipulated experimentally in ways shown previously to alter microbial community structure. One set of soil was subjected to chloroform fumigation for 0, 0.5, 2, or 24 h and the other was sterilised by gamma-irradiation and inoculated with a 10(-2), 10(-4), 10(-6), or 10(-8) dilution of a soil suspension prepared from unsterilized soil. Following incubation for 8 months, to allow for the stabilization of microbial biomass and activity, the resulting microbial community structure (determined by PCR-DGGE of bacterial specific amplification products of total soil DNA) was assessed. In addition, the functional stability (defined here as the resistance and resilience of short-term decomposition of plant residues to a transient heat or a persistent copper perturbation) was determined. Changes in the active bacterial population following perturbation (determined by RT-PCR-DGGE of total soil RNA) were also monitored. The manipulations resulted in distinct shifts in microbial community structure as shown by PCR-DGGE profiles, but no significant decreases in the number of bands. These shifts in microbial community structure were associated with a reduction in functional stability. The clear correlation between altered microbial community structure and functional stability observed in this upland pasture soil was not evident when the same protocols were applied to soils in other studies. RT-PCR-DGGE profiles only detected a shift in the active bacterial population following heat, but not copper, perturbation. We conclude that the functional stability of decomposition is related to specific components of the microbial community.

  14. The Head Injury Transportation Straight to Neurosurgery (HITS-NS) randomised trial: a feasibility study.

    PubMed

    Lecky, Fiona; Russell, Wanda; Fuller, Gordon; McClelland, Graham; Pennington, Elspeth; Goodacre, Steve; Han, Kyee; Curran, Andrew; Holliman, Damien; Freeman, Jennifer; Chapman, Nathan; Stevenson, Matt; Byers, Sonia; Mason, Suzanne; Potter, Hugh; Coats, Tim; Mackway-Jones, Kevin; Peters, Mary; Shewan, Jane; Strong, Mark

    2016-01-01

    Reconfiguration of trauma services, with direct transport of traumatic brain injury (TBI) patients to neuroscience centres (NCs), bypassing non-specialist acute hospitals (NSAHs), could potentially improve outcomes. However, delays in stabilisation of airway, breathing and circulation (ABC) and the difficulties in reliably identifying TBI at scene may make this practice deleterious compared with selective secondary transfer from nearest NSAH to NC. National Institute for Health and Care Excellence guidance and systematic reviews suggested equipoise and poor-quality evidence - with regard to 'early neurosurgery' in this cohort - which we sought to address. Pilot cluster randomised controlled trial of bypass to NC conducted in two ambulance services with the ambulance station (n = 74) as unit of cluster [Lancashire/Cumbria in the North West Ambulance Service (NWAS) and the North East Ambulance Service (NEAS)]. Adult patients with signs of isolated TBI [Glasgow Coma Scale (GCS) score of < 13 in NWAS, GCS score of < 14 in NEAS] and stable ABC, injured nearest to a NSAH were transported either to that hospital (control clusters) or bypassed to the nearest NC (intervention clusters). recruitment rate, protocol compliance, selection bias as a result of non-compliance, accuracy of paramedic TBI identification (overtriage of study inclusion criteria) and pathway acceptability to patients, families and staff. 'Open-label' secondary outcomes: 30-day mortality, 6-month Extended Glasgow Outcome Scale (GOSE) and European Quality of Life-5 Dimensions. Overall, 56 clusters recruited 293 (169 intervention, 124 control) patients in 12 months, demonstrating cluster randomised pre-hospital trials as viable for heath service evaluations. Overall compliance was 62%, but 90% was achieved in the control arm and when face-to-face paramedic training was possible. Non-compliance appeared to be driven by proximity of the nearest hospital and perceptions of injury severity and so

  15. Fundamentals of neurosurgery: virtual reality tasks for training and evaluation of technical skills.

    PubMed

    Choudhury, Nusrat; Gélinas-Phaneuf, Nicholas; Delorme, Sébastien; Del Maestro, Rolando

    2013-11-01

    Technical skills training in neurosurgery is mostly done in the operating room. New educational paradigms are encouraging the development of novel training methods for surgical skills. Simulation could answer some of these needs. This article presents the development of a conceptual training framework for use on a virtual reality neurosurgical simulator. Appropriate tasks were identified by reviewing neurosurgical oncology curricula requirements and performing cognitive task analyses of basic techniques and representative surgeries. The tasks were then elaborated into training modules by including learning objectives, instructions, levels of difficulty, and performance metrics. Surveys and interviews were iteratively conducted with subject matter experts to delimitate, review, discuss, and approve each of the development stages. Five tasks were selected as representative of basic and advanced neurosurgical skill. These tasks were: 1) ventriculostomy, 2) endoscopic nasal navigation, 3) tumor debulking, 4) hemostasis, and 5) microdissection. The complete training modules were structured into easy, intermediate, and advanced settings. Performance metrics were also integrated to provide feedback on outcome, efficiency, and errors. The subject matter experts deemed the proposed modules as pertinent and useful for neurosurgical skills training. The conceptual framework presented here, the Fundamentals of Neurosurgery, represents a first attempt to develop standardized training modules for technical skills acquisition in neurosurgical oncology. The National Research Council Canada is currently developing NeuroTouch, a virtual reality simulator for cranial microneurosurgery. The simulator presently includes the five Fundamentals of Neurosurgery modules at varying stages of completion. A first pilot study has shown that neurosurgical residents obtained higher performance scores on the simulator than medical students. Further work will validate its components and use in a

  16. Hand-tool-tissue interaction forces in neurosurgery for haptic rendering.

    PubMed

    Aggravi, Marco; De Momi, Elena; DiMeco, Francesco; Cardinale, Francesco; Casaceli, Giuseppe; Riva, Marco; Ferrigno, Giancarlo; Prattichizzo, Domenico

    2016-08-01

    Haptics provides sensory stimuli that represent the interaction with a virtual or tele-manipulated object, and it is considered a valuable navigation and manipulation tool during tele-operated surgical procedures. Haptic feedback can be provided to the user via cutaneous information and kinesthetic feedback. Sensory subtraction removes the kinesthetic component of the haptic feedback, having only the cutaneous component provided to the user. Such a technique guarantees a stable haptic feedback loop, while it keeps the transparency of the tele-operation system high, which means that the system faithfully replicates and render back the user's directives. This work focuses on checking whether the interaction forces during a bench model neurosurgery operation can lie in the solely cutaneous perception of the human finger pads. If this assumption is found true, it would be possible to exploit sensory subtraction techniques for providing surgeons with feedback from neurosurgery. We measured the forces exerted to surgical tools by three neurosurgeons performing typical actions on a brain phantom, using contact force sensors, while the forces exerted by the tools to the phantom tissue were recorded using a load cell placed under the brain phantom box. The measured surgeon-tool contact forces were 0.01-3.49 N for the thumb and 0.01-6.6 N for index and middle finger, whereas the measured tool-tissue interaction forces were from six to 11 times smaller than the contact forces, i.e., 0.01-0.59 N. The measurements for the contact forces fit the range of the cutaneous sensitivity for the human finger pad; thus, we can say that, in a tele-operated robotic neurosurgery scenario, it would possible to render forces at the fingertip level by conveying haptic cues solely through the cutaneous channel of the surgeon's finger pads. This approach would allow high transparency and high stability of the haptic feedback loop in a tele-operation system.

  17. Incidence of postoperative hematomas requiring surgical treatment in neurosurgery: a retrospective observational study.

    PubMed

    Lillemäe, Kadri; Järviö, Johanna; Silvasti-Lundell, Marja Kaarina; Antinheimo, Jussi; Hernesniemi, Juha; Niemi, Tomi Tapio

    2017-09-08

    We aimed to characterize the occurrence of postoperative hematoma (POH) after neurosurgery overall and according to procedure type, and describe the prevalence of possible confounders. Patient data between 2010 and 2012 at the Department of Neurosurgery in Helsinki University Hospital were retrospectively analyzed. Data search was performed according to the type of surgery including craniotomies; shunt procedures, spine surgery and spinal cord stimulators (SCS) implantation. We analyzed basic preoperative characteristics, as well as data about the initial intervention, perioperative period, revision operation and neurological recovery (after craniotomy only). The overall incidence of POH requiring reoperation was 0.6% (n= 56/8783) - 0.6% (n=26/4726) after craniotomy, 0% (n=0/928) after shunting procedure, 1.1% (n= 30/2870) after spine surgery and 0% (n=0/259) after implantation of SCS. Craniotomy types with higher POH incidence were: decompressive craniectomy (7.9%, n=7/89), cranioplasty (3.6%, n= 4/112), bypass surgery (1.7%, n= 1/60) and epidural hematoma evacuation (1.6%, n=1/64). After spinal surgery, POH was observed in 1.1% of cervical and 2.1% of thoracolumbar operations, whereas 46.7% were multilevel procedures. 64.3% of POH and 84.6% of craniotomy patients had postoperative hypertension (systolic blood pressure above 160 mmHg or lower if indicated). Poor outcome (Glasgow outcome scale class 1-3), whereas death at 6 months following craniotomy was detected accordingly in 40.9% and 21.7% of craniotomy patients with POH. POH after neurosurgery was rare in this series, but associated with poor outcome. Identification of risk factors of bleeding, and avoiding them, if possible, might decrease the incidence of POH. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. German Emergency Care in Neurosurgery and Military Neurology during World War II, 1939-1945.

    PubMed

    Stahnisch, Frank W

    2016-01-01

    A critical analysis of the historical involvement of neurology and neurosurgery in military emergency care services enables us to better contextualize and appreciate the development of modern neurology at large. Wartime neurosurgery and civil brain science during the German Nazi period tightly coalesced in examining the specific injury types, which military neurosurgeons such as Wilhelm Toennis, Klaus Joachim Zuelch, and Georg Merrem encountered and treated based on their neurophysiological understanding gained from earlier peacetime research. Collaborative associations with Dr. Toennis in particular proved to be highly beneficial to other military neurologists and neurosurgeons during World War II and beyond. This article also discusses the prewar developments and considers the fate of German neurosurgeons and military neurologists after the war. The envisaged dynamic concepts of fast action, reaction, and recycling, which contemporary physicians had intensively studied in the preceding scientific experiments in their neurophysiological laboratories, had already been introduced into neurological surgery during the interwar period. In retrospect, World War II emergency rescue units greatly strengthened military operations through an active process of 'recycling' indispensable army personnel. Neurosurgical emergency chains thereby introduced another decisive step in the modernization of warfare, in that they increased the momentum of military mobility in the field. Notwithstanding the violence of warfare and the often inhumane ways in which such knowledge in the field of emergency neurology was gained, the protagonists among the group of experts in military neurology and neurosurgery strongly contributed to the postwar clinical neuroscience community in Germany. In differing political pretexts, this became visible in both East Germany and West Germany after the war, while the specific military and political conditions under which this knowledge of emergency medicine

  19. A novel augmented reality system of image projection for image-guided neurosurgery.

    PubMed

    Mahvash, Mehran; Besharati Tabrizi, Leila

    2013-05-01

    Augmented reality systems combine virtual images with a real environment. To design and develop an augmented reality system for image-guided surgery of brain tumors using image projection. A virtual image was created in two ways: (1) MRI-based 3D model of the head matched with the segmented lesion of a patient using MRIcro software (version 1.4, freeware, Chris Rorden) and (2) Digital photograph based model in which the tumor region was drawn using image-editing software. The real environment was simulated with a head phantom. For direct projection of the virtual image to the head phantom, a commercially available video projector (PicoPix 1020, Philips) was used. The position and size of the virtual image was adjusted manually for registration, which was performed using anatomical landmarks and fiducial markers position. An augmented reality system for image-guided neurosurgery using direct image projection has been designed successfully and implemented in first evaluation with promising results. The virtual image could be projected to the head phantom and was registered manually. Accurate registration (mean projection error: 0.3 mm) was performed using anatomical landmarks and fiducial markers position. The direct projection of a virtual image to the patients head, skull, or brain surface in real time is an augmented reality system that can be used for image-guided neurosurgery. In this paper, the first evaluation of the system is presented. The encouraging first visualization results indicate that the presented augmented reality system might be an important enhancement of image-guided neurosurgery.

  20. Clinical practice audit concerning antimicrobial prophylaxis in paediatric neurosurgery: results from a German paediatric oncology unit.

    PubMed

    Weiss, Katja; Simon, Arne; Graf, Norbert; Schöpe, Jakob; Oertel, Joachim; Linsler, Stefan

    2017-01-01

    Perioperative antimicrobial prophylaxis (PAP) has been identified as an important target for internal audits, concerning the judicious use of antibiotics. Paediatric oncology patients with brain tumours face an increased risk of surgical site infection (SSI) after neurosurgery and receive routine PAP in this setting. All patients younger than 18 years admitted to the paediatric oncology centre (POC) with a neurosurgical intervention. Systematic audit of routine clinical data is divided in two groups: retrospective (Jan 01, 2012-March 31, 2014) and prospective (April 01, 2014-March 31, 2015) referring to an internal PAP guideline, invented in Jan. 2014). Surveillance of SSI up to 30 days after the operation with standard criteria (Centres for Disease Control and Prevention, USA). In total, 53 neurosurgical operations were analysed in 33 paediatric oncology patients. Twelve patients received more than one operation. The detailed analysis of PAP revealed prophylactic cefuroxim doses about 30 mg/kg instead of 50 mg/kg and no repeated dosing in operations lasting longer than 4 h. In addition, Cefotaxim, which is not indicated as PAP in neurosurgery, was used instead of Cefuroxim (or Ampicillin-Sulbactam) in 23 % of all cases in the retrospective and 18 % of all cases in the prospective audit. PAP for more than 3 doses (>24 h) was administered in 66 % in the retrospective group and in 60 % in the prospective group (p = n.s.). In both groups, no SSI was detected. This first comprehensive audit of PAP in paediatric oncology patients undergoing neurosurgery outlines significant opportunities to improve clinical practice in terms of correct dosing, the correct choice of the antibiotic, a correct timing schedule and a shorter duration of PAP. In addition, our results illustrate in detail the challenges in clinical practice when an evidence-based approach to improve a standard workflow has to be implemented.

  1. IBIS: an OR ready open-source platform for image-guided neurosurgery.

    PubMed

    Drouin, Simon; Kochanowska, Anna; Kersten-Oertel, Marta; Gerard, Ian J; Zelmann, Rina; De Nigris, Dante; Bériault, Silvain; Arbel, Tal; Sirhan, Denis; Sadikot, Abbas F; Hall, Jeffery A; Sinclair, David S; Petrecca, Kevin; DelMaestro, Rolando F; Collins, D Louis

    2017-03-01

    Navigation systems commonly used in neurosurgery suffer from two main drawbacks: (1) their accuracy degrades over the course of the operation and (2) they require the surgeon to mentally map images from the monitor to the patient. In this paper, we introduce the Intraoperative Brain Imaging System (IBIS), an open-source image-guided neurosurgery research platform that implements a novel workflow where navigation accuracy is improved using tracked intraoperative ultrasound (iUS) and the visualization of navigation information is facilitated through the use of augmented reality (AR). The IBIS platform allows a surgeon to capture tracked iUS images and use them to automatically update preoperative patient models and plans through fast GPU-based reconstruction and registration methods. Navigation, resection and iUS-based brain shift correction can all be performed using an AR view. IBIS has an intuitive graphical user interface for the calibration of a US probe, a surgical pointer as well as video devices used for AR (e.g., a surgical microscope). The components of IBIS have been validated in the laboratory and evaluated in the operating room. Image-to-patient registration accuracy is on the order of [Formula: see text] and can be improved with iUS to a median target registration error of 2.54 mm. The accuracy of the US probe calibration is between 0.49 and 0.82 mm. The average reprojection error of the AR system is [Formula: see text]. The system has been used in the operating room for various types of surgery, including brain tumor resection, vascular neurosurgery, spine surgery and DBS electrode implantation. The IBIS platform is a validated system that allows researchers to quickly bring the results of their work into the operating room for evaluation. It is the first open-source navigation system to provide a complete solution for AR visualization.

  2. The practice of cranial neurosurgery and the malpractice liability environment in the United States.

    PubMed

    Bekelis, Kimon; Missios, Symeon; Wong, Kendrew; MacKenzie, Todd A

    2015-01-01

    The potential imbalance between malpractice liability cost and quality of care has been an issue of debate. We investigated the association of malpractice liability with unfavorable outcomes and increased hospitalization charges in cranial neurosurgery. We performed a retrospective cohort study involving patients who underwent cranial neurosurgical procedures from 2005-2010, and were registered in the National Inpatient Sample (NIS) database. We used data from the National Practitioner Data Bank (NPDB) from 2005 to 2010 to create measures of volume and size of malpractice claim payments. The association of the latter with the state-level mortality, length of stay (LOS), unfavorable discharge, and hospitalization charges for cranial neurosurgery was investigated. During the study period, there were 189,103 patients (mean age 46.4 years, with 48.3% females) who underwent cranial neurosurgical procedures, and were registered in NIS. In a multivariable regression, higher number of claims per physician in a state was associated with increased ln-transformed hospitalization charges (beta 0.18; 95% CI, 0.17 to 0.19). On the contrary, there was no association with mortality (OR 1.00; 95% CI, 0.94 to 1.06). We observed a small association with unfavorable discharge (OR 1.09; 95% CI, 1.06 to 1.13), and LOS (beta 0.01; 95% CI, 0.002 to 0.03). The size of the awarded claims demonstrated similar relationships. The average claims payment size (ln-transformed) (Pearson's rho=0.435, P=0.01) demonstrated a positive correlation with the risk-adjusted hospitalization charges but did not demonstrate a correlation with mortality, unfavorable discharge, or LOS. In the present national study, aggressive malpractice environment was not correlated with mortality but was associated with higher hospitalization charges after cranial neurosurgery. In view of the association of malpractice with the economics of healthcare, further research on its impact is necessary.

  3. Simulation in neurosurgery: a review of computer-based simulation environments and their surgical applications.

    PubMed

    Malone, Hani R; Syed, Omar N; Downes, Michael S; D'Ambrosio, Anthony L; Quest, Donald O; Kaiser, Michael G

    2010-10-01

    Computer-based surgical simulators create a no-risk virtual environment where surgeons can develop and refine skills through harmless repetition. These applications may be of particular benefit to neurosurgeons, as the vulnerability of nervous tissue limits the margin for error. The rapid progression of computer-processing capabilities in recent years has led to the development of more sophisticated and realistic neurosurgery simulators. To catalogue the most salient of these advances and characterize our current effort to create a spine surgery simulator. An extensive search of the databases Ovid-MEDLINE, PubMed, and Google Scholar was conducted. Search terms included, but were not limited to: neurosurgery combined with simulation, virtual reality, haptics, and 3-dimensional imaging. A survey of the literature reveals that surgical simulators are evolving from platforms used for preoperative planning and anatomic education into programs that aim to simulate essential components of key neurosurgical procedures. This evolution is predicated upon the advancement of 3 main components of simulation: graphics/volume rendering, model behavior/tissue deformation, and haptic feedback. The computational burden created by the integration of these complex components often limits the fluidity of real-time interactive simulators. Although haptic interfaces have become increasingly sophisticated, the production of realistic tactile sensory feedback remains a formidable and costly challenge. The rate of future progress may be contingent upon international collaboration between research groups and the establishment of common simulation platforms. Given current limitations, the most potential for growth lies in the innovative design of models that expand the procedural applications of neurosurgery simulation environments.

  4. State of global pediatric neurosurgery outreach: survey by the International Education Subcommittee.

    PubMed

    Davis, Matthew C; Rocque, Brandon G; Singhal, Ash; Ridder, Thomas; Pattisapu, Jogi V; Johnston, James M

    2017-08-01

    OBJECTIVE Neurosurgical services are increasingly recognized as essential components of surgical care worldwide. The degree of interest among neurosurgeons regarding international work, and the barriers to involvement in global neurosurgical outreach, are largely unexplored. The authors distributed a survey to members of the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Joint Section on Pediatric Neurosurgery to assess the state of global outreach among its members and to identify barriers to involvement. METHODS An internet-based questionnaire was developed by the International Education Subcommittee of the AANS/CNS Joint Section on Pediatric Neurosurgery and distributed to pediatric neurosurgeons via the AANS/CNS Joint Section email contact list. Participants were surveyed on their involvement in global neurosurgical outreach, geographic location, nature of the participation, and barriers to further involvement. RESULTS A 35.3% response rate was obtained, with 116 respondents completing the survey. Sixty-one percent have performed or taught neurosurgery in a developing country, and 49% travel at least annually. Africa was the most common region (54%), followed by South America (30%), through 29 separate organizing entities. Hydrocephalus was the most commonly treated condition (88%), followed by spinal dysraphism (74%), and tumor (68%). Most respondents obtained follow-up through communications from local surgeons (77%). Seventy-one percent believed the international experience improved their practice, and 74% were very or extremely interested in working elsewhere. Interference with current practice (61%), cost (44%), and difficulty identifying international partners (43%) were the most commonly cited barriers to participation. CONCLUSIONS Any coordinated effort to expand global neurosurgical capacity begins with appreciation for the current state of outreach efforts. Increasing participation in global outreach will

  5. The Practice of Cranial Neurosurgery and the Malpractice Liability Environment in the United States

    PubMed Central

    Wong, Kendrew; MacKenzie, Todd A.

    2015-01-01

    Object The potential imbalance between malpractice liability cost and quality of care has been an issue of debate. We investigated the association of malpractice liability with unfavorable outcomes and increased hospitalization charges in cranial neurosurgery. Methods We performed a retrospective cohort study involving patients who underwent cranial neurosurgical procedures from 2005-2010, and were registered in the National Inpatient Sample (NIS) database. We used data from the National Practitioner Data Bank (NPDB) from 2005 to 2010 to create measures of volume and size of malpractice claim payments. The association of the latter with the state-level mortality, length of stay (LOS), unfavorable discharge, and hospitalization charges for cranial neurosurgery was investigated. Results During the study period, there were 189,103 patients (mean age 46.4 years, with 48.3% females) who underwent cranial neurosurgical procedures, and were registered in NIS. In a multivariable regression, higher number of claims per physician in a state was associated with increased ln-transformed hospitalization charges (beta 0.18; 95% CI, 0.17 to 0.19). On the contrary, there was no association with mortality (OR 1.00; 95% CI, 0.94 to 1.06). We observed a small association with unfavorable discharge (OR 1.09; 95% CI, 1.06 to 1.13), and LOS (beta 0.01; 95% CI, 0.002 to 0.03). The size of the awarded claims demonstrated similar relationships. The average claims payment size (ln-transformed) (Pearson’s rho=0.435, P=0.01) demonstrated a positive correlation with the risk-adjusted hospitalization charges but did not demonstrate a correlation with mortality, unfavorable discharge, or LOS. Conclusions In the present national study, aggressive malpractice environment was not correlated with mortality but was associated with higher hospitalization charges after cranial neurosurgery. In view of the association of malpractice with the economics of healthcare, further research on its impact is

  6. Simulator based angiography education in neurosurgery: results of a pilot educational program.

    PubMed

    Fargen, Kyle Michael; Siddiqui, Adnan H; Veznedaroglu, Erol; Turner, Raymond D; Ringer, Andrew J; Mocco, J

    2012-11-01

    The use of simulators in medical training has been on the rise over the past decade as a means to teach procedural skills to trainees in a risk free environment. The goal of this study was to pilot a simulator based skills course for inexperienced neurosurgical residents to teach the fundamentals of cervicocerebral catheterization and angiography, with the ultimate goal of defining a universal simulator based curriculum that could be incorporated into neurosurgical resident training in the future. Seven neurosurgery residents with no prior angiographic experience served as the pilot participants for this 2 day course. Four neurointerventional trained neurosurgeons served as faculty for instruction and evaluation. The majority of the course focused on hands-on simulator practice with close mentoring by faculty. Participants were evaluated with pre-course and post-course assessments. Post-course written test scores were significantly higher than pre-course scores (p<0.001). Faculty assessments of participants' technical skills with angiography (graded 0-10, with 10 being best) also improved significantly from pre-course to post-course (pre 2.1; post 5.9; p<0.001). Objective simulator recorded assessments demonstrated a significant decrease in the time needed to complete a four vessel angiogram (p<0.001) and total fluoroscopic time (p<0.001). Participant angiography skills, based on both faculty and simulator assessments, as well as participant knowledge, improved after this didactic, hands-on simulator course. Neuroendovascular simulator training appears to be a viable means of training inexperienced neurosurgery residents in the early learning stages of basic endovascular neurosurgery. Further studies evaluating the translation of procedural skills learned on the simulator to actual clinical skills in the angiography suite is necessary.

  7. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids

    PubMed Central

    Karunaweera, Sadish

    2015-01-01

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined. PMID:25637990

  8. Endothelin A-receptor blockade in experimental diabetes improves glucose balance and gastrointestinal function.

    PubMed

    Balsiger, Bruno; Rickenbacher, Andreas; Boden, Penelope Jane; Biecker, Erwin; Tsui, Janice; Dashwood, Michael; Reichen, Jürg; Shaw, Sidney George

    2002-08-01

    Secondary complications of diabetes mellitus often involve gastrointestinal dysfunction. In the experimental Goto Kakizaki rat, a model of Type II diabetes, hyperglycaemia and reduced glucose clearance is associated with elevated plasma endothelin (ET)-1 levels and selective decreases in nitric oxide synthase in circular muscle, longitudinal muscle and neuronal elements of the gastrointestinal tract. Functionally, this is accompanied by decreased nitrergic relaxatory responses of jejunal longitudinal muscle to tetrodotoxin-sensitive electrical field stimulation. Long-term treatment with a selective ET A-type receptor antagonist, markedly reduced hyperglycaemia and restored plasma glucose clearance rates towards normal. This was associated with a restoration of N(G)-nitro-L-arginine methyl ester-sensitive relaxatory responses of jejunal longitudinal muscle to electrical field stimulation. The results indicate that beneficial effects of ETA receptor blockade on gastrointestinal function may result from an improvement in insulin sensitivity with concomitant reduction of the severity of hyperglycaemia. ETA receptor blockade may represent a new therapeutic principle for improving glucose tolerance in Type II diabetes and could be beneficial in alleviating or preventing hyperglycaemia-related secondary complications in this condition.

  9. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids

    SciTech Connect

    Ploetz, Elizabeth A.; Karunaweera, Sadish; Smith, Paul E.

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined.

  10. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids.

    PubMed

    Ploetz, Elizabeth A; Karunaweera, Sadish; Smith, Paul E

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined.

  11. Noble gas adsorption in two-dimensional zeolites: a combined experimental and density functional theory study

    NASA Astrophysics Data System (ADS)

    Wang, Mengen; Zhong, Jianqiang; Boscoboinik, Jorge Anibal; Lu, Deyu