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Sample records for experimental functional neurosurgery

  1. Atlas-based system for functional neurosurgery

    NASA Astrophysics Data System (ADS)

    Nowinski, Wieslaw L.; Yeo, Tseng T.; Yang, Guo L.; Dow, Douglas E.

    1997-05-01

    This paper addresses the development of an atlas-based system for preoperative functional neurosurgery planning and training, intraoperative support and postoperative analysis. The system is based on Atlas of Stereotaxy of the Human Brain by Schaltenbrand and Wahren used for interactive segmentation and labeling of clinical data in 2D/3D, and for assisting stereotactic targeting. The atlas microseries are digitized, enhanced, segmented, labeled, aligned and organized into mutually preregistered atlas volumes 3D models of the structures are also constructed. The atlas may be interactively registered with the actual patient's data. Several other features are also provided including data reformatting, visualization, navigation, mensuration, and stereotactic path display and editing in 2D/3D. The system increases the accuracy of target definition, reduces the time of planning and time of the procedure itself. It also constitutes a research platform for the construction of more advanced neurosurgery supporting tools and brain atlases.

  2. 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

  3. Eloquent Brain, Ethical Challenges: Functional Brain Mapping in Neurosurgery.

    PubMed

    Klein, Eran

    2015-06-01

    Functional brain mapping is an increasingly relied upon tool in presurgical planning and intraoperative decision making. Mapping allows personalization of structure-function relationships when surgical or other treatment of pathology puts eloquent functioning like language or vision at risk. As an innovative technology, functional brain mapping holds great promise but also raises important ethical questions. In this article, recent work in neuroethics on functional imaging and functional neurosurgery is explored and applied to functional brain mapping. Specific topics discussed in this article are incidental findings, responsible innovation, and informed consent.

  4. 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.

  5. Neurosurgery: Functional regeneration after laser axotomy

    NASA Astrophysics Data System (ADS)

    Yanik, Mehmet Fatih; Cinar, Hulusi; Cinar, Hediye Nese; Chisholm, Andrew D.; Jin, Yishi; Ben-Yakar, Adela

    2004-12-01

    Understanding how nerves regenerate is an important step towards developing treatments for human neurological disease, but investigation has so far been limited to complex organisms (mouse and zebrafish) in the absence of precision techniques for severing axons (axotomy). Here we use femtosecond laser surgery for axotomy in the roundworm Caenorhabditis elegans and show that these axons functionally regenerate after the operation. Application of this precise surgical technique should enable nerve regeneration to be studied in vivo in its most evolutionarily simple form.

  6. 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. PMID:27194228

  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. Intra-operative micro-electrode recording in functional neurosurgery: Past, present, future.

    PubMed

    Maiti, Tanmoy K; Konar, Subhas; Bir, Shyamal; Kalakoti, Piyush; Nanda, Anil

    2016-10-01

    The field of functional neurosurgery has experienced a rise, fall and lastly a renaissance over the past 75years. Micro-electrode recording (MER) played a key role during this eventful journey. However, as the intra-operative MRI continues to evolve, a pertinent question about the utility of MER has been raised in recent years. In this article, we critically review these current controversies. The English literature is reviewed and the complex technique of MER is discussed in a simplified manner. The improvement of neuroimaging and its application in functional neurosurgery, especially in deep brain stimulation, is discussed. Finally, the current controversies and technical advances which can direct the future are reviewed. The results of existing meta-analyses addressing the controversies are summarized. Wide variations of pre-operative and intra-operative targeting methods have been described in the literature. Though functional neurosurgery is generally safe, complications do occur and multiple passes during MER can certainly add to the risk of inadvertent hemorrhage and infection. Additionally, the recent introduction of newer MRI modalities has ensured better delineation of the target. However, MER is still useful to address brain shift, for mapping of newer targets, for ablative surgeries and in centers without an intra-operative imaging facility. In the current scenario, it is nearly impossible to conduct a prospective study to decide the utility of MER. The importance of MER may further diminish in the future as a routine procedure, but its role as a gold standard procedure may still persist.

  9. Intra-operative micro-electrode recording in functional neurosurgery: Past, present, future.

    PubMed

    Maiti, Tanmoy K; Konar, Subhas; Bir, Shyamal; Kalakoti, Piyush; Nanda, Anil

    2016-10-01

    The field of functional neurosurgery has experienced a rise, fall and lastly a renaissance over the past 75years. Micro-electrode recording (MER) played a key role during this eventful journey. However, as the intra-operative MRI continues to evolve, a pertinent question about the utility of MER has been raised in recent years. In this article, we critically review these current controversies. The English literature is reviewed and the complex technique of MER is discussed in a simplified manner. The improvement of neuroimaging and its application in functional neurosurgery, especially in deep brain stimulation, is discussed. Finally, the current controversies and technical advances which can direct the future are reviewed. The results of existing meta-analyses addressing the controversies are summarized. Wide variations of pre-operative and intra-operative targeting methods have been described in the literature. Though functional neurosurgery is generally safe, complications do occur and multiple passes during MER can certainly add to the risk of inadvertent hemorrhage and infection. Additionally, the recent introduction of newer MRI modalities has ensured better delineation of the target. However, MER is still useful to address brain shift, for mapping of newer targets, for ablative surgeries and in centers without an intra-operative imaging facility. In the current scenario, it is nearly impossible to conduct a prospective study to decide the utility of MER. The importance of MER may further diminish in the future as a routine procedure, but its role as a gold standard procedure may still persist. PMID:27396672

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

    PubMed

    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

  11. 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

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

    PubMed

    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

  13. Development of computer-aided functions in clinical neurosurgery with PACS

    NASA Astrophysics Data System (ADS)

    Mukasa, Minoru; Aoki, Makoto; Satoh, Minoru; Kowada, Masayoshi; Kikuchi, K.

    1991-07-01

    The introduction of the "Picture Archiving and Communications System (known as PACS)," provides many benefits, including the application of C.A.D., (Computer Aided Diagnosis). Clinically, this allows for the measurement and design of an operation to be easily completed with the CRT monitors of PACS rather than with film, as has been customary in the past. Under the leadership of the Department of Neurosurgery, Akita University School of Medicine, and Southern Tohoku Research Institute for Neuroscience, Koriyama, new computer aided functions with EFPACS (Fuji Electric's PACS) have been developed for use in clinical neurosurgery. This image processing is composed of three parts as follows: (1) Automatic mapping of small lesions depicted on Magnetic Resonance (or MR) images on the brain atlas. (2) Superimposition of two angiographic films onto a single synthesized image. (3) Automatic mapping of the lesion's position (as shown on the. CT images) on the processing image referred to in the foregoing clause 2. The processing in the clause (1) provides a reference for anatomical estimation. The processing in the clause (2) is used for general analysis of the condition of a disease. The processing in the clause (3) is used to design the operation. This image processing is currently being used with good results.

  14. 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

  15. The status quo of neurosurgery in China.

    PubMed

    Zhao, Ji-Zong; Zhou, Liang-Fu; Zhou, Ding-Biao; Tang, Jie; Zhang, Dong

    2008-02-01

    With the application of great effort, much progress has been made to date in each specialty of neurosurgery in mainland China. In this article, we briefly review the present status of neurosurgery in China. The components and function of the Chinese Neurosurgical Society, the national organization for neurosurgery in China, are discussed. Neurosurgeons' acceptance of the concept of minimally invasive procedures has marked the start of an era of minimally invasive neurosurgery in China. Progress is evident in clinics, basic research, infrastructure, resident training, and multidisciplinary collaboration. Some weaknesses that need improvement are also mentioned. The current program offers a good basic foundation for development to meet future demands.

  16. 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.

  17. 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. PMID:22132699

  18. 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.

  19. 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

  20. 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.

  1. 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. PMID:22985531

  2. Interactive 3D visualization tools for stereotactic atlas-based functional neurosurgery

    NASA Astrophysics Data System (ADS)

    St. Jean, Philippe; Kasrai, Reza; Clonda, Diego; Sadikot, Abbas F.; Evans, Alan C.; Peters, Terence M.

    1998-06-01

    Many of the critical basal ganglia structures are not distinguishable on anatomical magnetic resonance imaging (MRI) scans, even though they differ in functionality. In order to provide the neurosurgeon with this missing information, a deformable volumetric atlas of the basal ganglia has been created from the Shaltenbrand and Wahren atlas of cryogenic slices. The volumetric atlas can be non-linearly deformed to an individual patient's MRI. To facilitate the clinical use of the atlas, a visualization platform has been developed for pre- and intra-operative use which permits manipulation of the merged atlas and MRI data sets in two- and three-dimensional views. The platform includes graphical tools which allow the visualization of projections of the leukotome and other surgical tools with respect to the atlas data, as well as pre- registered images from any other imaging modality. In addition, a graphical interface has been designed to create custom virtual lesions using computer models of neurosurgical tools for intra-operative planning. To date 17 clinical cases have been successfully performed using the described system.

  3. 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.

  4. 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

    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

  5. 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

  6. 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

    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

  7. Chronic Pain in Neurosurgery.

    PubMed

    Grodofsky, Samuel

    2016-09-01

    This review includes a summary of contemporary theories of pain processing and advocates a multimodal analgesia approach for providing perioperative care. A summary of various medication classes and anesthetic techniques is provided that highlights evidence emerging from neurosurgical literature. This summary covers opioid management, acetaminophen, nonsteroidal antiinflammatories, ketamine, lidocaine, dexmedetomidine, corticosteroids, gabapentin, and regional anesthesia for neurosurgery. At present, there is not enough investigation into these areas to describe best practices for treating or preventing chronic pain in neurosurgery; but providers can identify a wider range of options available to personalize perioperative care strategies. PMID:27521193

  8. 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

  9. Neurosurgery in India: an overview.

    PubMed

    Ganapathy, Krishnan

    2013-01-01

    This overview of neurosurgery in India during the last six decades gives a holistic perspective of the phenomenal advances made. Neurosurgical education, the change in clinical spectrum of diseases and their presentation, evolution of various subspecialties and societies, the state of research, the issues peculiar to India, including the urban-rural health divide, the increasing role of information and communication technology in neurosurgery, and the gradual but definite global recognition of Indian neurosurgery will be addressed.

  10. 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.

  11. 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.

  12. 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.

  13. Robotics in child neurosurgery.

    PubMed

    Giorgi, C; Sala, R; Riva, D; Cossu, A; Eisenberg, H

    2000-11-01

    We felt there was a need for a new device with "minimal invasive" tracking hardware, to be used in image-guided neurosurgery, and the system we designed to fill this need is now presented. It combines precision of movement, stability and self-positioning capabilities together with optically tracked registration and procedural control within the structure of a surgical microscope. The results are reduced setup time and minimal "distraction" from the procedure itself, factors of special relevance in child neurosurgery. The system is composed of a six-axis industrial robot suitable for use in the operating room, carrying a surgical microscope. Three progressive scan-synchronized infrared cameras mounted around the lenses of the scope are used to register the patient's position and track surgical instruments with reference to the registered space. Orientation of the microscope during surgery is obtained with a six-axis joystick used as a microscope handle. The system has been clinically used in 14 cases, and it has proven itself to be reliable, providing the expected performance advantages. The implementation of a tracked ultrasound or endoscope intraoperative imaging source is also described.

  14. Single Case Study: Neuropsychological Functioning in a Patient Diagnosed with Intermittent Explosive Disorder Pre and Post Neurosurgery.

    PubMed

    Alvarez-Alonso, María José; Morales-Muñoz, Isabel; Castaño-León, Ana María; Lagares, Alfonso; Rubio, Gabriel; Jurado-Barba, Rosa

    2016-05-10

    Intermittent explosive disorder (IED) is characterized by a difficulty to resist the urge to carry out a recognized harmful behavior. The central symptom is aggressiveness, expressed in isolated episodes. Executive function impairments are habitually found in impulse control disorders. Neuropsychology of impulsivity is related to dysfunctions in the orbito-frontal cortex, dorsolateral cortex and anterior-cingulated regions, being consequently involved in cognitive mechanisms of inhibition. Lesions in those areas are common in IED. In the most severe cases of IED, surgical procedures are required for treatment. In this study, we examined JML; a patient suffering from a severe case of IED. He experienced frequent episodes of auto and heteroaggression and multiple psychiatric admissions, and thus stereotactic surgery was the recommended treatment. The procedure consisted of an electrode situated lateral to the lateral ventricle, targeting the projections between frontal and subcortical affected regions. We aimed to study the neuropsychological functioning of JML, before and after electrode implantation. Our results suggested that surgery in IED improves cognitive performance at some levels. JML significantly improved his cognitive flexibility, measured with WCST, and alternate attention assessed with CPT and TMT-B tests, after electrode implantation. Cognitive flexibility deficits may be also related to increased aggressiveness. Therefore, improvements at this level may involve a reduction of impulsivity and aggressive behavior.

  15. 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.

  16. 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. PMID:26970479

  17. Neurosurgery: A legacy of excellence.

    PubMed

    Rajshekhar, Vedantam

    2015-01-01

    Neurosurgeons are often identified with traits such as arrogance and hubris. However, the true legacy of neurosurgeons is excellence. Harvey Cushing, the pioneering neurosurgeon of the United States, is largely responsible for this legacy of excellence. Eminent personalities have agreed that sincere and hard work is necessary to achieve excellence. Excellence in neurosurgery in the domains of surgical work and research will be discussed in the article. Excellence in surgical work should be measured comprehensively and over long follow-up periods using tools such as functional outcomes and quality of life instruments besides morbidity and mortality. For excellence in neurosurgical research, one can use the help of indices such as the h-index and i10 index. No single measure, whether for surgical excellence or excellence in research, however, incorporates a measure of qualities such as empathy, integrity and mentorship. These intangible qualities should be an integral part of the assessment of a neurosurgeon and his/her work. Cushing's attributes of meticulous record keeping, attention to detail, and maximal utilization of opportunities should guide us in our pursuit of excellence. In recent years, it has been suggested that excellence is not the result of an innate talent but can be aspired to by anyone willing to adopt a work ethic that involves several hours of "deliberate practice," feedback and passion. Neurosurgeons should continue to pursue the legacy of Cushing especially in present times when medical professionals are frequently depicted as being driven more by avarice than by Hippocratic principles. PMID:26238874

  18. Neurosurgery: A legacy of excellence.

    PubMed

    Rajshekhar, Vedantam

    2015-01-01

    Neurosurgeons are often identified with traits such as arrogance and hubris. However, the true legacy of neurosurgeons is excellence. Harvey Cushing, the pioneering neurosurgeon of the United States, is largely responsible for this legacy of excellence. Eminent personalities have agreed that sincere and hard work is necessary to achieve excellence. Excellence in neurosurgery in the domains of surgical work and research will be discussed in the article. Excellence in surgical work should be measured comprehensively and over long follow-up periods using tools such as functional outcomes and quality of life instruments besides morbidity and mortality. For excellence in neurosurgical research, one can use the help of indices such as the h-index and i10 index. No single measure, whether for surgical excellence or excellence in research, however, incorporates a measure of qualities such as empathy, integrity and mentorship. These intangible qualities should be an integral part of the assessment of a neurosurgeon and his/her work. Cushing's attributes of meticulous record keeping, attention to detail, and maximal utilization of opportunities should guide us in our pursuit of excellence. In recent years, it has been suggested that excellence is not the result of an innate talent but can be aspired to by anyone willing to adopt a work ethic that involves several hours of "deliberate practice," feedback and passion. Neurosurgeons should continue to pursue the legacy of Cushing especially in present times when medical professionals are frequently depicted as being driven more by avarice than by Hippocratic principles.

  19. 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. PMID:22059098

  20. 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

  1. 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. PMID:27006632

  2. 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.

  3. 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

  4. [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. PMID:27331235

  5. Defining excellence in vascular neurosurgery.

    PubMed

    Sanai, Nader; Spetzler, Robert F

    2010-01-01

    Success as a vascular neurosurgeon almost always begins with passion, an inherent love for the work that drives an insatiable desire for personal improvement. A personal definition of excellence in vascular neurosurgery includes several fundamental qualities: mastery of the basics, refinement of technique, advancement of technology, investigative study, advanced decision making, microsurgical innovation, a well-rounded surgical armamentarium, and a lifelong commitment to teaching. Ultimately, the reward for these efforts is the ability to influence generations to come, particularly as one follows the rising careers of former trainees, each redefining the term "excellence" in vascular neurosurgery.

  6. [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. PMID:20166531

  7. 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.

  8. Depression and neurosurgery: past, present, and future.

    PubMed

    Nicolaidis, Stylianos

    2005-05-01

    Neurosurgery has been used to treat depression since 1935, when open surgery was first used to isolate relatively large areas of the limbic system from the rest of the brain. Soon thereafter, more selective leucotomies were performed based on a growing knowledge of the role played by brain limbic circuitry in processing the emotions. Subsequent discovery of the effectiveness in depression of both electroconvulsive therapy and various pharmacotherapies raised serious doubts about "psychosurgical" treatments, but the introduction of stereotactic techniques revived interest in the selective-lesion, neurobiology-based approach. However, neurosurgery has only come to be regarded as an appropriate treatment of severe depression since Benabid introduced the frequency-dependent chronic electric stimulation technique. Because of its nondestructive nature, this procedure will undoubtedly be favored in the future. One can anticipate that, eventually, frequency-dependent chronic electric stimulation will be complemented by newer techniques such as microdialysis and reverse dialysis, with concomitant functional magnetic resonance imaging and/or positron emission tomography scanning, and the use of chemodes for microinfusion or for in situ insertion of reactivated-stem cells. To optimize success, these modern methods will require a new taxonomy of "depressions" based on up-to-date neurobiological criteria.

  9. 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.

  10. [A short history of endoscopic neurosurgery].

    PubMed

    Wang, Long; Song, Zhi-Bin; Gao, Jian-Wei; Li, Xu-Guangl

    2013-11-01

    Since 1910, rigid cystoscopy was first applied in the lateral ventricular choroid plexus cauterization for the treatment of congenital hydrocephalus, thus, opening up a new window in the endoscopic neurosurgery, but poor surgical outcome and high mortality made the application of endoscopic neurosurgery in question. Latterly, because of the appearance of new microscope and optical fiber endoscope, neuroendoscopy has been applied adequately in neurosurgery, with the increase of its clinical indications. Along with it, the concept of neuroendoscopy in surgery has changed, as well as the expansion of clinical indications. At present, neuroendoscopy technology has become a significant branch of modern neurosurgery. PMID:24524639

  11. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

    PubMed

    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

  12. 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

  13. Interstitial laser thermotherapy in neurosurgery: a review.

    PubMed

    Menovsky, T; Beek, J F; van Gemert, M J; Roux, F X; Bown, S G

    1996-01-01

    One of the most recent laser treatment modalities in neurosurgery is interstitial laser thermotherapy (ILTT). In this review, experimental and clinical studies concerning intracranial ILTT are discussed. Two methods for intra-operative control of the laser induced lesions are described; i.e., computer-controlled power delivery, using a thermocouple that is positioned interstitially at the periphery of the tumour to maintain the desired temperature at that point, and MRI, to visualise the extent of the thermal lesions induced by ILTT. The results show that ILTT using a Nd: YAG laser is easy and relatively effective in the treatment of small deep-seated brain tumours with minimal risk and complications. This review is concluded with suggestions for further improvement of this treatment modality.

  14. [Intraoperative neurophysiological monitoring improves outcome in neurosurgery].

    PubMed

    Sarnthein, J; Krayenbühl, N; Actor, B; Bozinov, O; Bernays, R

    2012-01-18

    Intraoperative Neurophysiological Mo-nitoring (IONM) identifies eloquent areas or nerves fibers during neurosurgical interventions and monitors their function. For several interventions IONM has become mandatory in neurosurgery. IONM increases patient safety during surgery as the risk of neurological deficits is reduced. Safer surgery reduces the time needed for the intervention and thereby reduces risk. IONM contributes to complete resection of tumors, which in turn prolongs patients' survival. Complicated surgical interventions associated with an elevated risk of neurological deficits have only become possible due to IONM. IONM comprises a variety of procedures that are selected for a particular intervention. With appropriate selection of the procedures IONM has been shown to improve neurological and functional outcome after neurosurgical interventions. PMID:22252591

  15. 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.

  16. 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.

  17. Experimental model updating using frequency response functions

    NASA Astrophysics Data System (ADS)

    Hong, Yu; Liu, Xi; Dong, Xinjun; Wang, Yang; Pu, Qianhui

    2016-04-01

    In order to obtain a finite element (FE) model that can more accurately describe structural behaviors, experimental data measured from the actual structure can be used to update the FE model. The process is known as FE model updating. In this paper, a frequency response function (FRF)-based model updating approach is presented. The approach attempts to minimize the difference between analytical and experimental FRFs, while the experimental FRFs are calculated using simultaneously measured dynamic excitation and corresponding structural responses. In this study, the FRF-based model updating method is validated through laboratory experiments on a four-story shear-frame structure. To obtain the experimental FRFs, shake table tests and impact hammer tests are performed. The FRF-based model updating method is shown to successfully update the stiffness, mass and damping parameters of the four-story structure, so that the analytical and experimental FRFs match well with each other.

  18. 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.

  19. 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. PMID:26585723

  20. A history of neurosurgery in Canada.

    PubMed

    Weir, Bryce

    2011-03-01

    Canada existed for more than half a century before there were glimmerings of modern neurosurgical activity. Neurosurgery had advanced significantly in Europe and the United States prior to its being brought to Toronto and Montreal from American centers. The pioneers responsible for the rapid evolution in practice, teaching and research are described. The interplay of scientific, professional, demographic and economic forces with general historical trends has produced dramatic changes in the way that neurosurgery is now practiced.

  1. [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

  2. Navigation system for neurosurgery with PC platform.

    PubMed

    Akatsuka, Y; Shibasaki, T; Saito, A; Kosaka, A; Matsuzaki, H; Asano, T; Furuhashi, Y

    2000-01-01

    This paper presents a navigation system for a surgical microscope and an endoscope which can be used for neurosurgery. In this system, a wireframe model of a target tumor and other significant anatomical landmarks are superimposed in real-time onto live video images taken from the microscope and the endoscope. The wireframe model is generated from a CT/MRI slice images. Overlaid images are simultaneously displayed in the same monitor using the picture-in-picture function so that the surgeon can concentrate on the single monitor during the surgery. The system measures the position and orientation of the patient using specially designed non-contact sensing devices mounted on the microscope and the endoscope. Based on this real-time measurement, the system displays other useful information about the navigation as well as the rendered wireframe. The accuracy of registration between the wireframe model and the actual live view is less than 2 mm. We tested this system in actual surgery several times, and verified its performance and effectiveness.

  3. Intraoperative Image Guidance in Neurosurgery: Development, Current Indications, and Future Trends

    PubMed Central

    Schulz, Chris; Waldeck, Stephan; Mauer, Uwe Max

    2012-01-01

    Introduction. As minimally invasive surgery becomes the standard of care in neurosurgery, it is imperative that surgeons become skilled in the use of image-guided techniques. The development of image-guided neurosurgery represents a substantial improvement in the microsurgical treatment of tumors, vascular malformations, and other intracranial lesions. Objective. There have been numerous advances in neurosurgery which have aided the neurosurgeon to achieve accurate removal of pathological tissue with minimal disruption of surrounding healthy neuronal matter including the development of microsurgical, endoscopic, and endovascular techniques. Neuronavigation systems and intraoperative imaging should improve success in cranial neurosurgery. Additional functional imaging modalities such as PET, SPECT, DTI (for fiber tracking), and fMRI can now be used in order to reduce neurological deficits resulting from surgery; however the positive long-term effect remains questionable for many indications. Method. PubMed database search using the search term “image guided neurosurgery.” More than 1400 articles were published during the last 25 years. The abstracts were scanned for prospective comparative trials. Results and Conclusion. 14 comparative trials are published. To date significant data amount show advantages in intraoperative accuracy influencing the perioperative morbidity and long-term outcome only for cerebral glioma surgery. PMID:22655196

  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). PMID:27366977

  6. Review of Robotic Technology for Stereotactic Neurosurgery.

    PubMed

    Faria, Carlos; Erlhagen, Wolfram; Rito, Manuel; De Momi, Elena; Ferrigno, Giancarlo; Bicho, Estela

    2015-01-01

    The research of stereotactic apparatus to guide surgical devices began in 1908, yet a major part of today's stereotactic neurosurgeries still rely on stereotactic frames developed almost half a century ago. Robots excel at handling spatial information, and are, thus, obvious candidates in the guidance of instrumentation along precisely planned trajectories. In this review, we introduce the concept of stereotaxy and describe a standard stereotactic neurosurgery. Neurosurgeons' expectations and demands regarding the role of robots as assistive tools are also addressed. We list the most successful robotic systems developed specifically for or capable of executing stereotactic neurosurgery. A critical review is presented for each robotic system, emphasizing the differences between them and detailing positive features and drawbacks. An analysis of the listed robotic system features is also undertaken, in the context of robotic application in stereotactic neurosurgery. Finally, we discuss the current perspective, and future directions of a robotic technology in this field. All robotic systems follow a very similar and structured workflow despite the technical differences that set them apart. No system unequivocally stands out as an absolute best. The trend of technological progress is pointing toward the development of miniaturized cost-effective solutions with more intuitive interfaces. PMID:25955851

  7. Review of Robotic Technology for Stereotactic Neurosurgery.

    PubMed

    Faria, Carlos; Erlhagen, Wolfram; Rito, Manuel; De Momi, Elena; Ferrigno, Giancarlo; Bicho, Estela

    2015-01-01

    The research of stereotactic apparatus to guide surgical devices began in 1908, yet a major part of today's stereotactic neurosurgeries still rely on stereotactic frames developed almost half a century ago. Robots excel at handling spatial information, and are, thus, obvious candidates in the guidance of instrumentation along precisely planned trajectories. In this review, we introduce the concept of stereotaxy and describe a standard stereotactic neurosurgery. Neurosurgeons' expectations and demands regarding the role of robots as assistive tools are also addressed. We list the most successful robotic systems developed specifically for or capable of executing stereotactic neurosurgery. A critical review is presented for each robotic system, emphasizing the differences between them and detailing positive features and drawbacks. An analysis of the listed robotic system features is also undertaken, in the context of robotic application in stereotactic neurosurgery. Finally, we discuss the current perspective, and future directions of a robotic technology in this field. All robotic systems follow a very similar and structured workflow despite the technical differences that set them apart. No system unequivocally stands out as an absolute best. The trend of technological progress is pointing toward the development of miniaturized cost-effective solutions with more intuitive interfaces.

  8. 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.

  9. Susceptibility artefact correction using dynamic graph cuts: application to neurosurgery.

    PubMed

    Daga, Pankaj; Pendse, Tejas; Modat, Marc; White, Mark; Mancini, Laura; Winston, Gavin P; McEvoy, Andrew W; Thornton, John; Yousry, Tarek; Drobnjak, Ivana; Duncan, John S; Ourselin, Sebastien

    2014-10-01

    Echo Planar Imaging (EPI) is routinely used in diffusion and functional MR imaging due to its rapid acquisition time. However, the long readout period makes it prone to susceptibility artefacts which results in geometric and intensity distortions of the acquired image. The use of these distorted images for neuronavigation hampers the effectiveness of image-guided surgery systems as critical white matter tracts and functionally eloquent brain areas cannot be accurately localised. In this paper, we present a novel method for correction of distortions arising from susceptibility artefacts in EPI images. The proposed method combines fieldmap and image registration based correction techniques in a unified framework. A phase unwrapping algorithm is presented that can efficiently compute the B0 magnetic field inhomogeneity map as well as the uncertainty associated with the estimated solution through the use of dynamic graph cuts. This information is fed to a subsequent image registration step to further refine the results in areas with high uncertainty. This work has been integrated into the surgical workflow at the National Hospital for Neurology and Neurosurgery and its effectiveness in correcting for geometric distortions due to susceptibility artefacts is demonstrated on EPI images acquired with an interventional MRI scanner during neurosurgery.

  10. 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

  11. 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.

  12. The 2012 AANS Presidential Address. We are neurosurgery.

    PubMed

    McCormick, Paul C

    2012-12-01

    The theme of the 80th Annual Meeting of the American Association of Neurological Surgeons and the title of this presidential address, "We are neurosurgery," is a simple 3-word affirmation of who neurosurgeons are, what they have achieved, and how much there is yet to accomplish. Recent advances in neurobiology and the clinical neurosciences have brought an unprecedented understanding of the human nervous system in both health and disease. As a specialty, neurosurgery has translated knowledge, expanded techniques, and incorporated technology to exponentially expand the science and scope of neurosurgical practice. However, the rapidly advancing, divergently evolving growth of neurosurgery has had profound effects on all aspects of neurosurgery. In this address, the author examines the contemporary meaning of the annual meeting's theme as it relates to the science, practice, specialty, and profession of neurosurgery, as well as the neurosurgeon. In doing so, the author reveals his interpretation of "We are neurosurgery," which he hopes will have an effect on others.

  13. 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

  14. Advances in neurosurgery: The Fujita Health University experience

    PubMed Central

    Kumar, Ashish

    2011-01-01

    In a world with rapidly changing technologies in the field of neurosurgery, Japan leads the world in many subspecialities like vascular neurosurgery. Apart from this, neuro-oncology and spinal surgeries are also among the premium quality operations performed in the region. I would like to share my experience of spending 3 months at the Fujita Health University, Nagoya, Japan, and the rich expertise and technologies encountered during the period, which made me understand Neurosurgery in a better way. PMID:22059102

  15. 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

  16. 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

  17. [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. PMID:27234912

  18. [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.

  19. 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.

  20. Neurosurgery and the dawning age of Brain-Machine Interfaces

    PubMed Central

    Rowland, Nathan C.; Breshears, Jonathan; Chang, Edward F.

    2013-01-01

    Brain–machine interfaces (BMIs) are on the horizon for clinical neurosurgery. Electrocorticography-based platforms are less invasive than implanted microelectrodes, however, the latter are unmatched in their ability to achieve fine motor control of a robotic prosthesis capable of natural human behaviors. These technologies will be crucial to restoring neural function to a large population of patients with severe neurologic impairment – including those with spinal cord injury, stroke, limb amputation, and disabling neuromuscular disorders such as amyotrophic lateral sclerosis. On the opposite end of the spectrum are neural enhancement technologies for specialized applications such as combat. An ongoing ethical dialogue is imminent as we prepare for BMI platforms to enter the neurosurgical realm of clinical management. PMID:23653884

  1. Neurosurgery and the dawning age of Brain-Machine Interfaces.

    PubMed

    Rowland, Nathan C; Breshears, Jonathan; Chang, Edward F

    2013-01-01

    Brain-machine interfaces (BMIs) are on the horizon for clinical neurosurgery. Electrocorticography-based platforms are less invasive than implanted microelectrodes, however, the latter are unmatched in their ability to achieve fine motor control of a robotic prosthesis capable of natural human behaviors. These technologies will be crucial to restoring neural function to a large population of patients with severe neurologic impairment - including those with spinal cord injury, stroke, limb amputation, and disabling neuromuscular disorders such as amyotrophic lateral sclerosis. On the opposite end of the spectrum are neural enhancement technologies for specialized applications such as combat. An ongoing ethical dialogue is imminent as we prepare for BMI platforms to enter the neurosurgical realm of clinical management. PMID:23653884

  2. The functions of language: an experimental study.

    PubMed

    Redhead, Gina; Dunbar, R I M

    2013-01-01

    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.

  3. Herbert Olivecrona: founder of Swedish neurosurgery.

    PubMed

    Ljunggren, B

    1993-01-01

    Herbert Olivecrona (1891-1980) singlehandedly founded Swedish neurosurgery. At the International Congress in Neurology in Bern in August, 1931, Harvey Cushing invited the cream of the world's medical society to a private banquet. Among the 28 specially invited guests was Herbert Olivecrona. At 40 years old, Olivecrona took his seat with pioneers such as Otfrid Foerster, Percival Bailey, Hugh Cairns, Geoffrey Jefferson, and Sir Charles Sherrington. This suggests that Cushing was impressed by the Swedish aristocrat's didactic deeds when he visited the Serafimer Hospital in Stockholm 2 years earlier. During the mid-1920's, the radiologist Erik Lysholm greatly improved the technique of ventriculography and, challenged by Olivecrona, his diagnostic neuroradiology became of superior quality. In the early 1930's, utilizing technical innovations of his own, Lysholm became a master at demonstrating and localizing posterior fossa tumors, which Olivecrona then operated on. Olivecrona's clinic became the mecca to which many scholars, thirsting for more knowledge, went on a pilgrimage. The international reputation of the clinic was founded, not on epoch-making discoveries, but by the resolute and practical application of methods already launched elsewhere and the exemplary organization that Olivecrona had established in collaboration with Lysholm. In spite of hardships and primitive working conditions, the clinic at the Serafimer Hospital gradually developed into the ideal prototype for a modern neurosurgical department. Olivecrona trained many colorful personalities who later were to lay the foundation for neurosurgery in their home countries; these included Wilhelm Tönnis of Germany, Edvard Busch of Denmark, and Aarno Snellman of Finland. Olivecrona was a true pioneer who made major contributions in practically all fields of conventional neurosurgery.

  4. Neurosurgery for mental disorders: a review.

    PubMed

    Heeramun-Aubeeluck, A; Lu, Z

    2013-05-01

    Neurosurgical interventions date back to ancient civilization, 5100 BC through a practice known as trephination. Due to past abuse and ethical considerations, neurosurgical interventions in psychiatry remain a controversial issue. This article aims to review the different surgical techniques and their current application in the treatment of psychiatric disorders. The U.S Food and Drug Administration (FDA) gave its approval for vagal nerve stimulation (VNS) for the management of treatment-resistant depression in 2005 and deep brain stimulation (DBS) for refractory obsessive-compulsive disorders (OCD) in 2009. These invasive but non destructive techniques represent the future of neurosurgery for mental disorder. PMID:23739819

  5. 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.

  6. Harvey Cushing: a founding father of neurosurgery.

    PubMed

    Ellis, Harold

    2009-10-01

    Harvey Cushing died 70 years ago, on 7 October, 1939, in his 71st year, of a myocardial infarction. He founded a school of neurosurgery whose disciples spread throughout the world, introduced the meticulous documentation of the clinical and pathological details of cerebral tumours, developed techniques of operative surgery which are now standard practice, has an endocrine disease which bears his name and even produced one of the best known medical biographies, the two-volume Life of Sir William Osler, which won the Pulitzer Prize for 1926. PMID:19966711

  7. 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. PMID:26947728

  8. Harvey Cushing: a founding father of neurosurgery.

    PubMed

    Ellis, Harold

    2009-10-01

    Harvey Cushing died 70 years ago, on 7 October, 1939, in his 71st year, of a myocardial infarction. He founded a school of neurosurgery whose disciples spread throughout the world, introduced the meticulous documentation of the clinical and pathological details of cerebral tumours, developed techniques of operative surgery which are now standard practice, has an endocrine disease which bears his name and even produced one of the best known medical biographies, the two-volume Life of Sir William Osler, which won the Pulitzer Prize for 1926.

  9. First experimental measurement of the Melnikov function

    NASA Astrophysics Data System (ADS)

    Meunier, Patrice; Huck, Peter; Villermaux, Emmanuel

    2014-11-01

    The problem of scalar mixing in a 2D flow has been extensively studied numerically by following Lagrangian tracers or theoretically using the tools of dynamical systems (KAM tori, quasi-periodic orbits, chaotic attractors...). However, in all these modelisations, the diffusion of the scalar is usually neglected for the purposes of the numerical/theoretical tools. We present here an experiment with an exactly 2D flow, which allows to study properly the diffusive and mixing problem at very large Peclet number. To avoid any 3D flow, the fluid is stratified with a linear density gradient using salted water. Moreover, the viscosity of the water is decreased of an order of magnitude by adding 10% ucon oil in the water. The flow under study is created by the co-rotation of two vertical cylinders, leading to a homoclinc point at the center. This base flow is perturbed periodically by a third oscillating cylinder. The dye injected at the center settles on the stable manifold of the homoclinic point. The distance between the stable and the unstable manifold is measured as half the distance between the maximum and the minimum of the dye's undulation. The results are in good quantitative agreement with the theoretical prediction of the Melnikov function for this flow.

  10. 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.

  11. 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

  12. 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

  13. The 2015 AANS Presidential Address: Neurosurgery's founding principles.

    PubMed

    Harbaugh, Robert E

    2015-12-01

    These are turbulent times for American neurosurgery. It is important to look ahead and prepare for the future but it is also important to look back-for it is memory and tradition that prevent the tyranny of the present. It is impossible to know where we are going if we don't remember where we were. In this paper I want to discuss the founding principles of neurosurgery-the principles that have allowed neurosurgery to prosper in its first century-and to stress the importance of adhering to these principles in times of change. I also want to talk to you about how the American Association of Neurological Surgeons (AANS) is helping neurosurgeons honor our founding principles, while preparing neurosurgery for its second century. PMID:26620322

  14. Simulation in neurosurgery: Past, present, and future.

    PubMed

    Suri, Ashish; Patra, Devi Prasad; Meena, Rajesh Kumar

    2016-01-01

    Neurosurgery is one of the most technically demanding medical professions that warrants a high level of expertise. In the present context of competitive medical practice, high societal expectations regarding quality of patient care and medicolegal and financial constraints, there are fewer opportunities for a trainee to achieve competency in standard neurosurgical, microsurgical, and operative techniques. Practice on simulation models like cadavers has been a trend since antiquity; however, recent development of newer models with their strategic modifications has given simulation education a new dimension. It has allowed trainees to acquire and improve surgical skills and knowledge in specifically fabricated and controlled settings with no risk to real patients. Simulation also offers the opportunity for deliberate practice and repetition unlimited number of times so that psychomotor skills can be automated. There is ever-growing evidence showing the positive impact of simulation on resident training in various areas of health care. Advances in computer technology and imaging, development of sophisticated virtual reality simulators with haptic feedback and the recent addition of three-dimensional printing technology, have opened a wide arena for the development of high-fidelity patient-specific models to complement current neurosurgical training. Simulation training in neurosurgery in India is still elementary since its inception at the All India Institute of Medical Sciences, New Delhi. A structured modular training program has been developed which is yet to be implemented at a multi-institutional level. Stringent efforts are needed to establish a uniform resident training curriculum where simulators can be used to complement current neurosurgical training. PMID:27147144

  15. 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. PMID:17961054

  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. 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.

  18. The 2012 AANS Presidential Address. We are neurosurgery.

    PubMed

    McCormick, Paul C

    2012-12-01

    The theme of the 80th Annual Meeting of the American Association of Neurological Surgeons and the title of this presidential address, "We are neurosurgery," is a simple 3-word affirmation of who neurosurgeons are, what they have achieved, and how much there is yet to accomplish. Recent advances in neurobiology and the clinical neurosciences have brought an unprecedented understanding of the human nervous system in both health and disease. As a specialty, neurosurgery has translated knowledge, expanded techniques, and incorporated technology to exponentially expand the science and scope of neurosurgical practice. However, the rapidly advancing, divergently evolving growth of neurosurgery has had profound effects on all aspects of neurosurgery. In this address, the author examines the contemporary meaning of the annual meeting's theme as it relates to the science, practice, specialty, and profession of neurosurgery, as well as the neurosurgeon. In doing so, the author reveals his interpretation of "We are neurosurgery," which he hopes will have an effect on others. PMID:23198859

  19. 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

  20. 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.

  1. Surveillance and management of ventriculitis following neurosurgery.

    PubMed

    Humphreys, H; Jenks, P J

    2015-04-01

    Ventriculitis is an important complication following neurosurgery and is often associated with the use of an external ventricular drain (EVD). The incidence varies from <5% to 20%, partly due to variations in the definitions used for diagnosis. Staphylococci are the most important causes but the isolation of coagulase-negative staphylococci from a cerebrospinal fluid (CSF) sample needs to be interpreted with caution as it may represent contamination. Risk factors for ventriculitis include advanced age, the duration of EVD placement, the number of manipulations and the presence of intraventricular haemorrhage. Prevention strategies increasingly focus on the implementation of a care bundle that includes aseptic technique at the time of insertion and during any manipulations, skin preparation, prophylactic antibiotics, and appropriate dressings at the site of the EVD. The use of EVDs impregnated with antimicrobial agents is increasing but, whereas some studies show that these are effective, it is not clear whether they provide added benefit when there is compliance with other measures. Antimicrobial treatment is challenging as many widely used agents do not penetrate into the CSF and causative bacteria are increasingly multidrug resistant. Often a combination of high-dose intravenous and intraventricular agents is required, especially for Gram-negative infections. Large trials in this area are challenging to conduct; therefore, to better inform preventive strategies and to optimize management of this important condition, ongoing national surveillance and pooling of data on treatment approaches and outcomes are needed. PMID:25687249

  2. 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

  3. Role of computer technology in neurosurgery.

    PubMed

    Abdelwahab, M G; Cavalcanti, D D; Preul, M C

    2010-08-01

    In the clinical office, during surgical planning, or in the operating room, neurosurgeons have been surrounded by the digital world either recreating old tools or introducing new ones. Technological refinements, chiefly based on the use of computer systems, have altered the modus operandi for neurosurgery. In the emergency room or in the office, patient data are entered, digitally dictated, or gathered from electronic medical records. Images from every modality can be examined on a Picture Archiving and Communication System (PACS) or can be seen remotely on cell phones. Surgical planning is based on high-resolution reconstructions, and microsurgical or radiosurgical approaches can be assessed precisely using stereotaxy. Tumor resection, abscess or hematoma evacuation, or the management of vascular lesions can be assisted intraoperatively by new imaging resources integrated into the surgical microscope. Mathematical models can dictate how a lesion may recur as well as how often a particular patient should be followed. Finally, virtual reality is being developed as a training tool for residents and surgeons by preoperatively simulating complex surgical scenarios. Altogether, computerization at each level of patient care has been affected by digital technology to help enhance the safety of procedures and thereby improve outcomes of patients undergoing neurosurgical procedures.

  4. The history of neurosurgery at the University of Rochester.

    PubMed

    Kimmell, Kristopher T; Petraglia, Anthony L; Bakos, Robert; Rodenhouse, Thomas; Maurer, Paul K; Pilcher, Webster H

    2014-10-01

    The Department of Neurosurgery at the University of Rochester has a long legacy of excellent patient care and innovation in the neurosciences. The department's founder, Dr. William Van Wagenen, was a direct pupil of Harvey Cushing and the first president of the Harvey Cushing Society. His successor, Dr. Frank P. Smith, was also a leader in organized neurosurgery and helped to permanently memorialize his mentor with an endowed fellowship that today is one of the most prestigious training awards in neurosurgery. The first 2 chiefs are honored every year by the department with memorial invited lectureships in their names. The department is home to a thriving multidisciplinary research program that fulfills the lifelong vision of its founder, Dr. Van Wagenen. PMID:25105700

  5. MINOP: development of a miniaturized endoscopic operation system for neurosurgery

    NASA Astrophysics Data System (ADS)

    Guber, Andreas E.; Wieneke, Paul

    1996-04-01

    Within the framework of R&D activities in the field of microsystems technology, the Institute for Microstructure Technology of Karlsruhe Research Center among others has started to improve the functionality of existing medicotechnical instruments by increased integration of microtechnical components. On the basis of microsystems fabrication techniques, completely novel medical endoscope systems have become feasible. In cooperation with clinical, technical and industrial partners, a novel endoscopic operation system based on microsystems technology is being developed by the Institute for Microstructure Technology and the Aesculap AG company, Tuttlingen within the framework of the MINOP joint project. This new system shall be applied above all in the field of neurosurgery. This newly conceived endosystem is characterized by a multitude of novelties. It can perform a number of both sensor and actor functions. Due to its extremely small outer diameter, it can be applied through minute openings. As a result of the integrated microfluidic control system, the flexible endoscope can be moved to the actual site of operation on a previously specified path. This will allow future bi- and triportal neuro-endoscopic interventions for critical operations in the brain area. The different lumina of the flexible endoscope fulfill various functions. Via the optical fibers, laser radiation may be led to the distal end of the endoscope. Using microtechnical fabrication methods, special plastic microlenses have been produced. The working channel can be applied for rinsing and removal. Furthermore, the cleaning of the optics or the taking of tissue samples are possible. If required, another laser fiber can be driven forward through the working channel for selective therapy. For the first time, high-performance microinstruments have been developed on the basis of novel materials. These instruments can be applied either through the working channel or through an additional trocar.

  6. 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.

  7. The functional mechanism of simvastatin in experimental osteoporosis.

    PubMed

    Dai, Lifen; Xu, Ming; Wu, Haiying; Xue, Lanjie; Yuan, Dekai; Wang, Yuan; Shen, Zhiqiang; Zhao, Hongbin; Hu, Min

    2016-01-01

    Osteoporosis is a systemic and metabolic bone disease. New drugs with good curative effect, fewer side effects, and high safety need to be developed urgently. Recently, simvastatin has been used to treat osteoporosis more frequently; however, its clinical effect and treatment mechanism are still unknown. With the use of animal models, the treatment effectiveness of simvastatin on experimental osteoporosis was investigated and the functional mechanism was preliminarily explored. The results show that simvastatin significantly increased the mechanical parameters such as maximum load, stiffness, and energy-absorbing capacity, and improved the microarchitecture. They indicated that the antiosteoporosis activity of simvastatin may be due to the promotion of proliferation and differentiation of osteoblasts. Simvastatin was effective in treating experimental osteoporosis. This study provides necessary experimental evidence for the clinical application of simvastatin in osteoporosis treatment.

  8. What can functional neuroimaging tell the experimental psychologist?

    PubMed

    Henson, Richard

    2005-02-01

    I argue here that functional neuroimaging data--which I restrict to the haemodynamic techniques of fMRI and PET--can inform psychological theorizing, provided one assumes a "systematic" function-structure mapping in the brain. In this case, imaging data simply comprise another dependent variable, along with behavioural data, that can be used to test competing theories. In particular, I distinguish two types of inference: function-to-structure deduction and structure-to-function induction. With the former inference, a qualitatively different pattern of activity over the brain under two experimental conditions implies at least one different function associated with changes in the independent variable. With the second type of inference, activity of the same brain region(s) under two conditions implies a common function, possibly not predicted a priori. I illustrate these inferences with imaging studies of recognition memory, short-term memory, and repetition priming. I then consider in greater detail what is meant by a "systematic" function-structure mapping and argue that, particularly for structure-to-function induction, this entails a one-to-one mapping between functional and structural units, although the structural unit may be a network of interacting regions and care must be taken over the appropriate level of functional/structural abstraction. Nonetheless, the assumption of a systematic function-structure mapping is a "working hypothesis" that, in common with other scientific fields, cannot be proved on independent grounds and is probably best evaluated by the success of the enterprise as a whole. I also consider statistical issues such as the definition of a qualitative difference and methodological issues such as the relationship between imaging and behavioural data. I finish by reviewing various objections to neuroimaging, including neophrenology, functionalism, and equipotentiality, and by observing some criticisms of current practice in the imaging

  9. Emergence and early development of Russian neurosurgery (1890s-1930s).

    PubMed

    Lichterman, Boleslav

    2007-01-01

    This paper is a case study of specialization in clinical medicine - it is a story of the difficult and complicated birth of a neurosurgery clinic in Russia and the Soviet Union. It demonstrates the futile attempt to institute a new specialty as surgical neurology advocated by neuro(patho)logist V.M. Bekhterev (1857-1927) and implemented by his pupils L.M. Pussep (1875-1942) and A.G. Molotkov (1874-1950). However, surgical neurology was gradually replaced by neurological surgery performed by general surgeons N.N. Burdenko (1875-1946), A.L. Polenov (1871-1947), and V.N. Shamov (1882-1962). Part of my paper is dedicated to the institutional history (emergence of the Institute of Surgical Neurology in Leningrad (in 1926) and the Central Institute of Neurosurgery in Moscow (in 1934). The Moscow Neurosurgical School was focused on lesions of the central nervous system whereas the Leningrad neurosurgical school dealt primarily with peripheral nerve surgery. In the 1930s neurosurgical clinics were established beyond the two capitals - in Rostov-on-Don, Kharkov, and Gorky. Similar to the centralized five-year planning in the Soviet economy, a new discipline of neurosurgery was also centralized and planned from Moscow in the 1930s. It was characterized by kompleksnost' - concentration of several auxiliary disciplines (neuroradiology, neuroophthalmology, neurophysiology, etc.) within neurosurgical research institutions in Leningrad and Moscow. Particular stress was made on the experimental nature of a new discipline, which was viewed as a sort of applied neurophysiology.

  10. Franc D. Ingraham and the genesis of pediatric neurosurgery.

    PubMed

    Lohani, Subash; Cohen, Alan R

    2013-06-01

    In 1929, Franc D. Ingraham, Harvey Cushing's protégé, established the first pediatric neurosurgical unit in the world at Boston Children's Hospital and dedicated his career to the neurosurgical care of children. He trained with both Cushing and Dandy and spent 1 year working in Oxford with Sherrington, who considered Ingraham to be the finest operative surgeon ever to work in his laboratory. Ingraham was instrumental in developing novel treatments, which he compiled in his classic book, Neurosurgery of Infancy and Childhood. Although he was modest and shy, Ingraham loved to entertain children with magic and enjoyed photography in and out of the operating room. Unfortunately, his career was plagued by personal illness, and he died young in 1965 at the age of 67. Despite his prolific 36-year neurosurgical career, Ingraham remained an associate professor at Harvard at his retirement. To recognize his remarkable contributions, Harvard established an endowed chair in his name in 1967. Ingraham was a pioneer and a leader in the development of pediatric neurosurgery by virtue of his imagination, intelligence, and ability to lead and inspire others. Cushing has come to be regarded as the founder of neurosurgery. It is fair to conclude that Ingraham, his disciple, is the founder of pediatric neurosurgery. PMID:23601016

  11. Battling blood loss in neurosurgery: Harvey Cushing's embrace of electrosurgery.

    PubMed

    Voorhees, Jennifer R; Cohen-Gadol, Aaron A; Laws, Edward R; Spencer, Dennis D

    2005-04-01

    For his pioneering spirit, definitive work, and unparalleled devotion to conquering neurosurgery's toughest obstacles, Harvey Williams Cushing inarguably has earned the title, "The Father of Neurosurgery." His revolutionary incorporation of electrosurgical techniques in neurosurgery was not exceptional, but part of a pattern of recognizing, embracing, and establishing the use of medical technologies with great potential. Until 1910, Cushing had systematically reduced neurosurgery's primary complications--infection and the effects of intracranial pressure--to decrease mortality rates. Hemostasis had always been a concern of William Halsted's surgical protégé, but only after 1910 could Cushing primarily focus on it. In fact, Cushing's crucial collaboration with William T. Bovie and his electrosurgical apparatus conquered this major obstacle in 1926. The nature of their collaboration--two experts in their respective fields who were passionate about their work, working side by side in the operating room--resulted in progress that surpassed all predecessors in the field. Cushing never did learn the physics behind one of the most important advances of his career. Nonetheless, he did know that by greatly reducing blood loss, electrosurgery allowed him to operate in patients whose tumors had been previously deemed inoperable and on the entire spectrum of neurosurgical patients more safely.

  12. 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

  13. Experimental moments of the nucleon structure function F2

    SciTech Connect

    Mikhail Osipenko; W. Melnitchouk; Silvano Simula; Sergey Kulagin; Giovanni Ricco

    2007-12-01

    Experimental data on the F2 structure functions of the proton and deuteron, including recent results from CLAS at Jefferson Lab, have been used to construct their n<=12 moments. A comprehensive analysis of the moments in terms of the operator product expansion has been performed to separate the moments into leading and higher twist contributions. Particular attention was paid to the issue of nuclear corrections in the deuteron, when extracting the neutron moments from data. The difference between the proton and neutron moments was compared directly with lattice QCD simulations. Combining leading twist moments of the neutron and proton we found the d/u ratio at x->1 approaching 0, although the precision of the data did not allow to exclude the 1/5 value. The higher twist components of the proton and neutron moments suggest that multi-parton correlations are isospin independent.

  14. Compact multi-spectral imaging system for dermatology and neurosurgery

    NASA Astrophysics Data System (ADS)

    Noordmans, Herke Jan; de Roode, Rowland; Verdaasdonk, Rudolf

    2007-03-01

    A compact multi-spectral imaging system is presented as diagnostic tool in dermatology and neurosurgery. Using an electronically tunable filter, a sensitive high resolution digital camera, 140 spectral images from 400 nm up to 720 nm are acquired in 40 s. Advanced image processing algorithms are used to enable interactive acquisition, viewing, image registration and image analysis. Experiments in the department of dermatology and neurosurgery show that multispectral imaging reveals much more detail than conventional medical photography or a surgical microscope, as images can be reprocessed to enhance the view on e.g. tumor boundaries. Using a hardware-based interactive registration algorithm, multi-spectral images can be aligned to correct for motion occurred during image acquisition or to compare acquisitions from different moments in time. The system shows to be a powerful diagnostics tool for medical imaging in the visual and near IR range.

  15. Opportunities and dangers for neurosurgery in the current NHS.

    PubMed

    Bell, B Anthony

    2015-01-01

    The NHS is entering a third decade of administrative turbulence and cost pressures and many view the new NHS structure and systems as complex and confusing. Health and social care budgets are being merged in some geographical areas and large efficiency savings are needed by 2020. There are risks that lie ahead for neurosurgery and our patients if the specialty becomes further fragmented and opportunities for positive change are missed. One of the new care models proposed in the NHS five year plan is specialist care provided across multiple hospital sites by a single overarching specialist trust, mirroring ophthalmology where the Moorfields trust provides specialist eye services in over 20 locations in London and the South East. This model lends itself to adoption by neurosurgery and has the potential to increase standards, efficiency, training and research. PMID:26488224

  16. 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.

  17. 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.

  18. The influence of war on the development of neurosurgery.

    PubMed

    Dowdy, Justin; Pait, T Glenn

    2014-01-01

    The treatment of craniospinal war wounds proved to be a significant driving force in the early growth of neurosurgery as a specialty. This publication explores the historical relationship between the evolution of combat methodology from antiquity through modern conflicts as it dovetails with and drives corresponding advancements in the field of neurosurgery. Whether it's the basic management principles for intracranial projectile wounds derived from World War I experiences, the drastic improvement in the outcomes and management of spinal cord injuries observed in World War II, or the fact that both of these wars played a crucial role in the development of a training system that is the origin of modern residency programs, the influence of wartime experiences is pervasive.

  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. PMID:27070016

  20. Historical perspective on neurosurgery in Germany after World War II.

    PubMed

    Collmann, Hartmut; Vitzthum, Hans-Ekkehart

    2008-11-01

    AFTER THE COLLAPSE of the Third Reich, the specialty of neurosurgery in Germany, although well developed in the late 1930s, had to start anew, and for decades to come, had to deal with the physical and political consequences of World War II. Because of the division of the country, neurosurgery developed separately in the two independent states. In West Germany, the evolution was promoted by a few personalities who represented different schools according to their own training: these "surgical neurologists" emphasized the neurological basis of neurosurgery and were represented by Traugott Riechert and the students of Otfrid Foerster, such as Arist Stender and Hans Kuhlendahl. In contrast, the "neurological surgeons" stressed their origins in general surgery. Their main proponent was Wilhelm Tönnis, who gained particular merit for promoting neurosurgical teaching, the development of new neurosurgical units, and the recognition of neurosurgery as an autonomous specialty. In East Germany, progress was delayed by a weak economy and a repressive political system. Yet several excellent neurosurgeons won international recognition, predominantly Georg Merrem, who came from the school of Fedor Krause. Following a worldwide trend, the number of neurosurgical units in West Germany increased dramatically from 18 in 1950 to 85 in 1988. In 2006, in the unified nation, 1200 certified neurosurgeons in 138 hospital departments and 75 private practices served 82 million people. Since its founding in 1949, the German Neurosurgical Society has promoted the idea of reconciliation and has focused on international collaboration in both science and education. This idea, shared by other European nations, eventually gave rise to the European Association of Neurosurgical Societies. At present, escalating costs in the health sector pose a problem to neurosurgical services and have led to reconsiderations about their structure and financing.

  1. Neurosurgery at the Radcliffe Infirmary, Oxford: a history.

    PubMed

    Aziz, T Z; Adams, C B

    1995-09-01

    Neurosurgery started in Oxford in 1938. In this article, we commence the story of Oxford neurosurgery with Thomas Willis and trace the historical thread through William Osler, Charles Sherrington, John Fulton, and Harvey Cushing to Hugh Cairns. The department in Oxford is renowned for the training of neurosurgeons. The initial stimulus for this was the abundance of neurosurgical and neurological expertise in Oxford during World War II with Cairns, and this tradition continued with Joe Pennybacker and his successors. The large and ever increasing work load ensures trainees a wide exposure to challenging neurosurgical problems. An increasing emphasis placed on research has resulted in the creation of two posts; each consists of half-time clinical neurosurgery and half-time research. Hugh Cairns organized the department along "Cushing lines." This organization still exists, allowing us to treat a large number of patients with relatively few beds and an average length of patient stay less than 6 days. We look to the future with confidence.

  2. The role of imaging in the development of neurosurgery.

    PubMed

    Kirkman, Matthew A

    2015-01-01

    The development of modern neurosurgery was, and remains, intimately associated with developments in radiology. Neuroimaging advances have been instrumental in improving patient care and reducing both morbidity and mortality for neurosurgical patients. The purpose of this narrative review is to provide the contemporary neurosurgeon with an overview of the history of the development of radiology as applied to neurosurgery. The focus is on cranial imaging but the spine is also discussed. This article demonstrates the remarkable advancements that have shaped our modern surgical specialty. Today, almost 120 years after the discovery of the X-ray, the neurosurgeon has a wide array of neuroimaging tools at their disposal, that have led to better knowledge to inform diagnosis and management, selection of appropriate patients and surgical targets, as well as optimal surgical approaches. Modern neurosurgery is based on the appropriate use of these investigations. The pace of neuroimaging and neurosurgical advances continues and the future promises to be as, if not more, exciting as the past and present described in this paper. PMID:25150767

  3. Topical antibiotics and neurosurgery: Have we forgotten to study it?

    PubMed Central

    Alves, Raphael Vicente; Godoy, Roberto

    2010-01-01

    Background: For neurosurgery, the last decades have been a time of incredible improvement in areas such as imaging, microscopy, endoscopy, stereotactic guidance, navigation, radiosurgery and endovascular techniques. However, the efficacy of topical antibiotic prophylaxis in neurological operations remains to be established by neurosurgeons. Methods: The authors did an historical review of the literature regarding the utilization of topical antibiotic prophylaxis in neurological operations. The Pub Med database of the U.S. National Library of Medicine / National Institutes of Health was utilized as the primary source of the literature. The authors performed the search by using the following Mesh terms: “neurosurgery” or “neurosurgical procedures” and “administration, topical” and “antibiotic prophylaxis”; “neurosurgery” or “neurosurgical procedures” and “administration, topical” and “antibacterial agents.” Results: In the last 70 years, we have poorly studied the use of topical antibiotics in neurosurgery. All the papers reported were Class III evidence. Conclusion: To the best of our knowledge, there is no publication that provided Class I or II evidence about topical antibiotic prophylaxis in neurosurgery. PMID:20882106

  4. 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

  5. Macular Structure and Function in Nonhuman Primate Experimental Glaucoma

    PubMed Central

    Wilsey, Laura J.; Reynaud, Juan; Cull, Grant; Burgoyne, Claude F.; Fortune, Brad

    2016-01-01

    Purpose To evaluate structure and function of macular retinal layers in nonhuman primate (NHP) experimental glaucoma (EG). Methods Twenty-one NHP had longitudinal imaging of macular structure by SDOCT, 16 also had recordings of function by multifocal ERG. The average thickness over 15° was derived for seven individual SDOCT layers: macular nerve fiber layer (m-NFL), retinal ganglion cell layer (RGCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer+inner segments combined (ONL+IS), and outer segments (OS). Peripapillary RNFL thickness (ppRNFLT) was measured from a single circular B-scan with 12° diameter. Responses to a slow-sequence multifocal ERG (mfERG) stimulus (7F) were filtered (at 75 Hz) into low- and high-frequency components (LFC, HFC). Results At final follow-up, significant structural loss occurred only in EG eyes and only for ppRNFLT (−29 ± 23%), m-NFL (−17 ± 16%), RGCL (−22 ± 15%), and IPL (−19 ± 14%); though there was also a small increase in OPL (+6 ± 7%) and ONL+IS (4 ± 4%) and a similar tendency for INL. Macular structural loss was correlated with ppRNFLT only for the NFL, RGCL and IPL (R = 0.95, 0.93 and 0.95, respectively, P < 0.0001). Significant functional loss occurred only for HFC and N2 in EG eyes. Significant longitudinal structure–function correlations (P < 0.01) were observed only in EG eyes and only for mfERG HFC and N2: HFC was correlated with ppRNFLT (R = 0.69), macular NFL (R = 0.67), RGCL (R = 0.74), and IPL (R = 0.72); N2 was correlated with RGCL (R = 0.54) and IPL (R = 0.48). High-frequency components amplitude change was inversely correlated with outer retinal thickness change (= −0.66). Conclusions Macular structural and functional losses are correlated and specific to ganglion cells over a wide range of EG severity. Outer retinal changes are likely due to inner retinal loss. PMID:27082305

  6. 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. PMID:26411987

  7. 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.

  8. 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.

  9. 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 Self-retaining retractor for neurosurgery....

  10. Intraoperative monitoring of the motor function: experimental and clinical study.

    PubMed

    Kaneko, M; Fukamachi, A; Sasaki, H; Miyazawa, N; Yagishita, T; Nukui, H

    1988-01-01

    Manipulation of the lesions adjacent to the primary motor area or the motor pathway is troublesome for neurosurgeons because they lack an effective method to determine the primary motor area or to monitor motor function in the operative room. It will be of great value to establish a monitoring method of the corticospinal tract under general anaesthesia. We recorded the motor evoked potential (MEP) from direct motor cortex stimulation in cats and showed that it derives almost purely from the corticospinal tract. Then we used this technique during the operation of the resection of tumours near the primary motor area or the motor pathway. 1. Experimental study: Twenty adult cats were used in this study. Recording electrodes were flexible bipolar catheter electrodes inserted into the spinal epidural space. Stimulating electrodes were silver ball electrode on the cortex (anode) and needle electrode in the temporal muscle (cathode). Stimulation of 4-24 V, 5-10 Hz and 0.2 msec in duration were done and evoked potentials signals were averaged 60 to 512 times. MEP with multiple peaks was obtained that had a 112 msec conduction velocity in the spinal cord. We found the same signals from the stimulation of ipsilateral cerebral peduncle. Radiofrequency lesioning of ipsilateral cerebral peduncle produced a loss of MEP. These results show that MEP derives from the corticospinal tract. Significant wave form change, with components of short latency, was noted by the excessively intense stimuli. We supposed that superimposition of the signals from the extrapyramidal pathways, excited in the brain stem, results in this change.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Laserthermia And New PDT In Neurosurgery

    NASA Astrophysics Data System (ADS)

    Sakai, Tsuneo; Fujishima, Ichiro; Sugiyama, Kenji

    1989-09-01

    The usefulness of laserthermia using Nd:YAG laser was studied experimentally and clinically to treat deep seated brain tumor. Histological changes, temperature profile, modification of blood-brain barrier (BBB) were studied. Five patients with brain tumors were treated with laserthermia. Laserthermia using Nd:YAG laser is easy and safe to use and it is beneficial to treat deep seated brain tumor. Photodynamic therapy (PDT) was also evaluated using the photosensitizing agent pheophorbide-a (Ph-a) and an acoustic Q switched Nd:YAG laser. In xitro survival of T98G human glioma cells pretreated with Ph-a (1x10-3 mole/1 in albumin) and irradiated with a pulsed Nd:YAG laser for 5 minutes at 37.0°C was 0.4%. The present study suggested that PDT using an acoustic Q switched Nd:YAG laser and Ph-a was useful in treating experimental human glioma.

  12. Robot-assisted microscope for neurosurgery.

    PubMed

    Giorgi, C; Eisenberg, H; Costi, G; Gallo, E; Garibotto, G; Casolino, D S

    1995-01-01

    We describe the implementation of a robotic arm connected to a neurosurgical operative microscope. A force feedback sensor drives the motors of the arm in response to the positioning of the microscope by the surgeon. Computer graphic techniques allow tracking of the current position of the microscope within the volumetric reconstruction of the brain. The integration of the prototype into the neurosurgical operating room is currently being evaluated. Preliminary comments on this experimental phase are offered.

  13. Robot-assisted microscope for neurosurgery.

    PubMed

    Giorgi, C; Eisenberg, H; Costi, G; Gallo, E; Garibotto, G; Casolino, D S

    1995-01-01

    We describe the implementation of a robotic arm connected to a neurosurgical operative microscope. A force feedback sensor drives the motors of the arm in response to the positioning of the microscope by the surgeon. Computer graphic techniques allow tracking of the current position of the microscope within the volumetric reconstruction of the brain. The integration of the prototype into the neurosurgical operating room is currently being evaluated. Preliminary comments on this experimental phase are offered. PMID:9079441

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. A frameless stereotaxic operating microscope for neurosurgery

    SciTech Connect

    Friets, E.M.; Strohbehn, J.W.; Hatch, J.F. ); Roberts, D.W. )

    1989-06-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given.

  19. A frameless stereotaxic operating microscope for neurosurgery.

    PubMed

    Friets, E M; Strohbehn, J W; Hatch, J F; Roberts, D W

    1989-06-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given. PMID:2659493

  20. 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. PMID:26621420

  1. 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. PMID:23254804

  2. [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.

  3. 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.

  4. Alzheimer's disease: The role for neurosurgery

    PubMed Central

    Pereira, Julio Leonardo Barbosa; Downes, Angela; Gorgulho, Alessandra; Patel, Vishal; Malkasian, Dennis; De Salles, Antonio

    2014-01-01

    Dementia, most commonly caused by Alzheimer's disease (AD), affects approximately 35 million people worldwide, with the incidence expected to increase as the population ages. After decades of investigation, AD is now understood to be a complex disease that affects behavior and cognition through several mechanisms: Disrupted neuronal communication, abnormal regional tissue metabolism, and impaired cellular repair. Existing therapies have demonstrated limited efficacy, which has spurred the search for specific disease markers and predictors as well as innovative therapeutic options. Deep brain stimulation (DBS) of the memory circuits is one such option, with early studies suggesting that modulation of neural activity in these networks may improve cognitive function. Encapsulated cell biodelivery (ECB) is a device that delivers nerve growth factor to the cholinergic basal forebrain to potentially improve cognitive decline in AD patients. This review discusses the pathogenesis of AD, novel neuroimaging and biochemical markers, and the emerging role for neurosurgical applications such as DBS and ECB. PMID:25289167

  5. Alzheimer's disease: The role for neurosurgery.

    PubMed

    Pereira, Julio Leonardo Barbosa; Downes, Angela; Gorgulho, Alessandra; Patel, Vishal; Malkasian, Dennis; De Salles, Antonio

    2014-01-01

    Dementia, most commonly caused by Alzheimer's disease (AD), affects approximately 35 million people worldwide, with the incidence expected to increase as the population ages. After decades of investigation, AD is now understood to be a complex disease that affects behavior and cognition through several mechanisms: Disrupted neuronal communication, abnormal regional tissue metabolism, and impaired cellular repair. Existing therapies have demonstrated limited efficacy, which has spurred the search for specific disease markers and predictors as well as innovative therapeutic options. Deep brain stimulation (DBS) of the memory circuits is one such option, with early studies suggesting that modulation of neural activity in these networks may improve cognitive function. Encapsulated cell biodelivery (ECB) is a device that delivers nerve growth factor to the cholinergic basal forebrain to potentially improve cognitive decline in AD patients. This review discusses the pathogenesis of AD, novel neuroimaging and biochemical markers, and the emerging role for neurosurgical applications such as DBS and ECB.

  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. 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…

  8. 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…

  9. 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…

  10. Perfluorocarbons: recent developments and implications for neurosurgery.

    PubMed

    Sakas, D E; Whittaker, K W; Crowell, R M; Zervas, N T

    1996-08-01

    Over the last 30 years, perfluorocarbons (PFCs) have been extensively investigated as oxygen carriers. Early studies indicated that these compounds could be used as blood substitutes or protective agents against ischemia. Adverse characteristics such as instability, short intravascular half-life, and uncertainties concerning possible toxicity precluded wide clinical application. However, advances in PFC technology have led to the development of improved second-generation oxygen carriers that incorporate well-tolerated emulsifiers (egg-yolk phospholipids). The authors review recent developments in this field and consider the potential role of PFCs in future neurosurgical practice. Diagnostic applications could include their use to assess cerebral blood flow, local oxygen tension, and brain metabolism or to achieve enhanced imaging and precise staging of inflammatory, neoplastic, or vascular disease processes by means of computerized tomography, ultrasonography, and magnetic resonance studies. Therapeutic applications could include cerebral protection, an adjunctive role in radiotherapy of malignant brain tumors, protection against air embolism, the preservation of organs for transplantation, and ventilatory support in head-injured patients with compromised lung function. In addition, PFCs have been used successfully as a tool in ophthalmic microsurgery and potentially they could fulfill a similar role in microneurosurgery. PMID:8755753

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. [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. PMID:24934513

  19. Challenges to neurosurgery service delivery. Who moved my cheese?

    PubMed

    Palmer, J D

    2007-04-01

    The change programme in the National Health Service has moved the Acute Trusts providing neurosurgical services to very different ways of delivering healthcare. The process of reform has been supported by investment but the next few years will see far less additional money, and success and failure of services will be dependent upon the approach to those reforms. The 'payment by results' system of funding through tariff, the 'plurality of providers' policy of forcing commissioners to purchase activity from independent providers, the 'patient choice' process of encouraging patients to select treatment from a number of providers, and the '18-week wait' target of bringing down referral to treatment times are all major shifts in the way services are delivered and developed. The reforms have not been made with neurosurgery in mind, how will they affect the way this small specialty is delivered? PMID:17453785

  20. 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.

  1. Harvey Cushing and "birth hemorrhage": early pediatric neurosurgery at The Johns Hopkins Hospital.

    PubMed

    Mehta, Vivek A; Wijesekera, Olindi; Pendleton, Courtney; Quiñones-Hinojosa, Alfredo; Jallo, George I; Ahn, Edward S

    2011-12-01

    Of Harvey Cushing's many contributions to neurosurgery, one of the least documented is his early surgical intervention in children and his pioneering efforts to establish pediatric neurosurgery as a subspecialty. Between 1896 and 1912 Cushing conducted nearly 200 operations in children at The Johns Hopkins Hospital. A review of his records suggests that the advances he made in neurosurgery were significantly influenced by his experience with children. In this historical article, the authors describe Cushing's treatment of 6 children, in all of whom Cushing established a diagnosis of "birth hemorrhage." By reviewing Cushing's operative indications, techniques, and outcomes, the authors aim to understand the philosophy of his pediatric neurosurgical management and how this informed his development of neurosurgery as a new specialty. PMID:22132925

  2. 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.

  3. [FRACTIONATED STEREOTACTIC RADIOSURGERY: A GAME CHANGER FOR NEUROSURGERY].

    PubMed

    Nissim, Ouzi; Spiegelmann, Roberto

    2016-05-01

    The article by Dr. Cohen-Inbar published in this issue of Harefuah is a timely review that brings to the general medical community the recent important developments in the field of radiosurgery--the evolution of multi-session radiosurgery [or "FSR", standing for Fractionated Stereotactic Radiation]. Radiosurgery and FSR continue to have a tremendous impact on modern neurosurgery. Sharing sub-millimetric accuracy in radiation delivery made possible by real-time-imaging positioning, frameless single and multisession radiosurgery have become two faces of a therapeutic technique with wide application in the field of intracranial pathology. Blending dose fractionation with delivery precision, FSR is a hybrid tool that can be implemented safely and effectively for practically any intra-cranial pathology without restrictions of volume or location. Dr. Cohen Inbar reviews the available data regarding doses, fractionation schemes, and results for the different pathologies in which FSR is being increasingly applied. FSR, as single-dose radiosurgery since the late 1980s, has changed the practice of neurosurgery. Radical microsorgical tumor removal at any cost in demanding intracranial locations has been replaced by upfront conservative volume-reduction surgery, leaving the more complicated part of those tumors to safer elimination by precise irradiation in single or multiple sessions. In Israel, further to the first unit operative since 1993 at the Sheba Medical Center, 3 new active LINAC based treatment sites have been added in recent years, with facilities either planned or under construction in the remaining major medical centers with neurosurgical and radiotherapy resources. They are evidence of the central role this modality has captured in the management of intracranial pathology. PMID:27526561

  4. Experimental investigation of Lagrangian structure functions in turbulence.

    PubMed

    Berg, Jacob; Ott, Søren; Mann, Jakob; Lüthi, Beat

    2009-08-01

    Lagrangian properties obtained from a particle tracking velocimetry experiment in a turbulent flow at intermediate Reynolds number are presented. Accurate sampling of particle trajectories is essential in order to obtain the Lagrangian structure functions and to measure intermittency at small temporal scales. The finiteness of the measurement volume can bias the results significantly. We present a robust way to overcome this obstacle. Despite no fully developed inertial range, we observe strong intermittency at the scale of dissipation. The multifractal model is only partially able to reproduce the results. PMID:19792258

  5. 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).

  6. 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. PMID:26885021

  7. 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

  8. Functional abnormalities of experimental autogenous vein graft neoendothelium.

    PubMed Central

    Cross, K S; el-Sanadiki, M N; Murray, J J; Mikat, E M; McCann, R L; Hagen, P O

    1988-01-01

    When a vein is grafted into the arterial circulation, the endothelium of the graft is damaged. Regeneration of an intact neoendothelium occurs, but the functional properties of this surface have not been clarified. In this study, the functional integrity of the neoendothelium of veins grafted into the carotid artery of the rabbit was assessed through the use of acetylcholine and histamine to stimulate the production of the important endothelium-derived relaxing factor (EDRF). Control veins, precontracted with norepinephrine [10(-5) M], relaxed after exposure to acetylcholine [( 10(-7) M], 42.4% +/- 6.4%, p = 0.008) and histamine [( 10(-6) M], 30.6% +/- 4.3%, p = 0.03). This relaxation response was abolished after mechanical removal of the endothelium. By contrast, neither acetylcholine nor histamine caused an endothelium-dependent relaxation in the vein grafts, even though scanning electron microscopy demonstrated the presence of a morphologically intact endothelium. However, addition of stabilized EDRF purified from cultured endothelial cells induced relaxation of the vein grafts (35.8% +/- 3.6%, p = 0.002). These data indicate that vein graft endothelium is unable to produce EDRF in response to exposure to acetylcholine or histamine. The inability to produce this potent smooth muscle cell relaxing factor and anti-aggregatory substance may be a predisposition to vein graft failure. Images Figs. 4A-C. Fig. 4. (Continued) Fig. 4. (Continued) Figs. 5A-C. Fig. 5. (Continued) Fig. 5. (Continued) Fig. 6. PMID:3263843

  9. 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.

  10. 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.

  11. [Structural and functional findings in experimental blind loop syndrome].

    PubMed

    Riecken, E O

    1984-01-01

    Proximal and distal the blindsack a villus and crypt prolongation connected with a decreasing absorption of octanoate could be pointed out. The structural changes are very likely a hyperplasia of the mucosa. Within the blindsack a hyperplasia in connection with an accelerated proliferation of cells and an almost three and a halffold enlargement of the surface of the villi could be found. Simultaneously, the mucosa was damaged. An artificial bile duct as well as a neomycin therapy caused a decrease of the structural and functional changes but did not prevent the mucosal hyperplasia. These results are explained with adaptive processes of the small intestinal mucosa in a sense of hyperregeneration alterations of sprue typus.

  12. Neutrophil function in an experimental model of hemolytic uremic syndrome.

    PubMed

    Vedanarayanan, V V; Kaplan, B S; Fong, J S

    1987-03-01

    To understand the role of neutrophil leukocytosis in hemolytic uremic syndrome, we studied the changes in neutrophil function in the modified generalized Shwartzman reaction in rabbits. This model resembles hemolytic uremic syndrome associated with endotoxemia. At the end of an endotoxin infusion, we observed leukopenia, thrombocytopenia, and a decrease in hematocrit associated with schistocytosis. Plasma B-glucuronidase levels increased and this was associated with a decrease in neutrophil content of the enzyme. The chemotactic index and neutrophil aggregation to zymosan-activated serum were impaired compared to controls. The neutrophil procoagulant content increased after endotoxin infusion. The serum creatinine concentration and proteinuria increased in the endotoxin-treated animals. The changes returned to normal by 48 h. Renal cortical malondialdehyde, a reflection of lipid peroxidation, was higher in the endotoxin-treated animals than in the controls. We have shown enzyme release by neutrophils, impairment of chemotaxis and aggregation, increased procoagulant content in neutrophils, and evidence of lipid peroxidation in renal cortical tissue in this model. These observations raise the possibility that leukocytes may have a role in the pathogenesis of the hemolytic uremic syndrome. PMID:3550673

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

    PubMed Central

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

    2013-01-01

    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. PMID:23619340

  14. Conjugating the "Tenses" of Function: Discordance among Hypothetical, Experimental, and Enacted Function in Older Adults.

    ERIC Educational Resources Information Center

    Glass, Thomas A.

    1998-01-01

    Proposes a conceptual model to describe and understand differences between functional capability and actual functional performance in the home. Results indicate that many older people appear to be both overachieving and underachieving in their functional performance relative to self-reports of functional capacity.(MKA)

  15. Thermal Model to Investigate the Temperature in Bone Grinding for Skull Base Neurosurgery

    PubMed Central

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

    2013-01-01

    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 3 mm in the traverse direction, and 3 mm 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. PMID:23683875

  16. Complex haemostatic abnormalities as a cause of bleeding after neurosurgery in a patient with Gaucher disease.

    PubMed

    Mitrovic, Mirjana; Elezovic, Ivo; Grujicic, Danica; Miljic, Predrag; Suvajdzic, Nada

    2015-01-01

    We report a treatment-naïve patient with Gaucher disease (GD) who experienced repeated bleeding after three neurosurgeries for a brain tumour, identified as an oligoastrocytoma. The patient had normal values on basic haemostatic tests: prothrombin time, 75-105%; activated partial thromboplastin time, 30.3-34 s; and mild thrombocytopaenia, 96-115 × 10(9 )cells/l. However, additional tests showed mild von Willebrand factor (vWF) deficiency (vWF antigen, 56%; vWF ristocetin cofactor, 49%; factor VIII [FVIII], 54%) and abnormal collagen-mediated platelet aggregation (0.45-0.55). Bleeding control was achieved after vWF/FVIII concentrate and platelet transfusions. This case raises questions about the safe platelet count and basic haemostatic tests for assessing bleeding risk in patients with GD prior to surgery. In patients with GD, a minimum haemostatic evaluation should include platelet count and basic haemostatic tests such as fibrinogen, prothrombin time, activated partial thromboplastin time as well as platelet function tests and assessing vWF and FVIII levels. Specific coagulation factors or platelet function deficiencies should be corrected with factor concentrates or platelet transfusions.

  17. History and current state of neurosurgery at the Medical University of South Carolina.

    PubMed

    Krishna, Vibhor; Rauf, Yasmeen; Patel, Sunil; Glazier, Steve; Perot, Phanor; Ellegala, Dilantha B

    2011-07-01

    We review the development of neurosurgery at the Medical University of South Carolina (MUSC) and the emergence of MUSC as a leading academic neurosurgical center in South Carolina. Historical records from the Waring Historical Library were studied, former and current faculty members were interviewed, and the personal records of Dr Phanor J Perot were examined. Dr Frederick E Kredel was the first to perform cerebral revascularization in stroke patients using omental flaps and the first to culture glioma cells in artificial media. The MUSC Neurosurgery residency program was established in 1964 by its first formally trained neurosurgeon, Julian Youmans, MD. The first graduate of the program, Dr Russell Travis, went on to become the President of the American Association of Neurological Surgeons. In 1968, the longest serving chairman, Dr Perot, joined the department and conducted significant research in spinal cord injury, receiving a continuous, 20-year award from the National Institute of Neurological Disorders and Stroke. A major change in the neurosurgery program occurred in 2004 when Dr Sunil Patel accepted the chairmanship. He integrated neurosurgery, neurology, and basic neuroscience departments into a comprehensive Department of Neurosciences to provide integrated clinical care. This department now ranks second in the country in National Institutes of Health research funding. Recently, the Center for Global Health and Global Neurosurgery was established with a vision of caring for patients beyond national borders. Neurosurgery at MUSC has been influenced by Drs Kredel and Perot and the current leadership is moving forward with a uniquely integrated department with novel areas such as global neurosurgery. PMID:21368698

  18. 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.

  19. The future of practice science: challenges and opportunities for neurosurgery.

    PubMed

    Selden, Nathan R; Ghogawala, Zoher; Harbaugh, Robert E; Litvack, Zachary N; McGirt, Matthew J; Asher, Anthony L

    2013-01-01

    Outcomes-directed approaches to quality improvement have been adopted by diverse industries and are increasingly the focus of government-mandated reforms to health care education and delivery. The authors identify and review current reform initiatives originating from agencies regulating and funding graduate medical education and health care delivery. These reforms use outcomes-based methodologies and incorporate principles of lifelong learning and patient centeredness. Important new initiatives include the Accreditation Council for Graduate Medical Education Milestones; the pending adoption by the American Board of Neurological Surgery of new requirements for Maintenance of Certification that are in part outcomes based; initiation by health care systems and consortia of public reporting of patient outcomes data; institution by the Centers for Medicare & Medicaid Services of requirements for comparative effectiveness research and the physician quality reporting system; and linking of health care reimbursement in part to patient outcomes data and quality measures. Opportunities exist to coordinate and unify patient outcomes measurement throughout neurosurgical training and practice, enabling effective patient-centered improvements in care delivery as well as efficient compliance with regulatory mandates. Coordination will likely require the development of a new science of practice based in the daily clinical environment and utilizing clinical data registries. A generation of outcomes science and quality experts within neurosurgery should be trained to facilitate attainment of these goals.

  20. 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

  1. Stereotactic Neurosurgery Planning On A PC Based Workstation.

    NASA Astrophysics Data System (ADS)

    Peters, Terence M.; Clark, John A.; Pike, Gordon; Henri, Christopher J.; Collins, D. L.; Leksell, Dan; Jeppsson, Ola

    1989-05-01

    Stereotactic surgery requires knowledge of cerebral structures derived from more than one image source. We have developed a PC-AT based workstation which accepts patient images, made with the stereotactic frame in place, from CT, MRI and DSA modalities. Reference markers on the frame are identified in the images to establish the coordinate geometry for each modality. Target points may be identified on each image type and trajectories of probe paths to these points defined. Targets identified on one set of images may be transferred automatically to other images of the same patient, in order, for example, to guarantee a vascular free path of approach to a target point deep within the brain. To date several hundred patients have had stereotactic surgery performed on the basis of plans using this system. Procedures included biopsy and aspiration of lesions, implantation of electrodes for the recording of deep EEG signals, and radiosurgical techniques based on the use of a high energy linear accelerator. We present clinical examples of the use of this system in typical stereotactic neurosurgery procedures, address stereoscopic applications, and discuss the results of inter-modality tests to establish the accuracy of the technique.

  2. 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.

  3. [Antiphospholipid antibody syndrome in pediatric neurosurgery: a hemostasis problem].

    PubMed

    Bocquet, R; Blanot, S; Dautzenberg, M D; Pierre-Kahn, A; Carli, P

    1999-11-01

    The case of a 11-year-old boy under anticoagulant therapy for a familial antiphospholipid antibody syndrome (SAAPF), who underwent surgery for a cerebrovascular malformation responsible for an intracerebral haematoma, is reported. Antivitamins K (AVK) were changed for unfractioned heparin (HNF), three days before. Heparin was discontinued two hours prior to surgery to obtain a normal peroperative coagulation. A vascular dural fistula was removed without any haemostatic problem. The neurological status rapidly returned to normal and tomodensitometry at day 1 showed a normal intracranial status. Heparin was readministered at h 16. Thrombocytopenia occurred at day 4 of heparin treatment. The change for a low weight molecular heparinoid, danaparoid (Orgaran), normalized the platelet count. The platelets aggregation tests were negative during thrombopenia. However, the test for antibodies against the PF4-heparin complex with the Elisa technique, was in favour of a heparin induced thrombocytopenia (TIH). In spite of its anecdotic occurrence due to cumulative thrombotic risks from the association of immunologic disorders (TIH and SAAPF), this case report underlines the value but also the risks of anticoagulant therapy in neurosurgery, when patients are at high risk for thrombosis.

  4. 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…

  5. 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…

  6. 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.

  7. 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.

  8. 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. PMID:26621419

  9. 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. PMID:22364441

  10. 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). PMID:26037173

  11. Central trigeminocardiac reflex in pediatric neurosurgery: a case report and review of the literature

    PubMed Central

    2012-01-01

    Introduction Trigeminocardiac reflex is a well-known phenomenon in neurosurgery, craniofacial surgery, ophthalmology and interventional neuroradiology. Even though the trigeminocardiac reflex has become an important factor in skull base surgery and neurosurgery, the central form of trigeminocardiac reflex has only been described in adult subpopulations until now. Case presentation We present a clear form of repetitive trigeminocardiac reflex expressed during revision surgery of a giant (110×61mm) right temporoparietal meningioma in an 18-month-old male Caucasian patient. After cessation of the surgical stimulus, his heart rate and mean arterial blood pressure returned to normal physiological levels. The further follow-up was uneventful. Conclusion Our case demonstrates that the central trigeminocardiac reflex also exists in pediatric patients, especially if manipulating trigeminal innervated structures or around the nerve itself. Whether the incidence and the behavior of the trigeminocardiac reflex is similar in pediatric neurosurgery compared with adult patients has to be shown in further studies. PMID:23110862

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Constantin N. Arseni (1912-1994) centenary: the birth of modern neurosurgery in Romania.

    PubMed

    Dinca, Eduard B; Banu, Matei; Ciurea, Alexandru V

    2014-01-01

    Prof. Dr. Constantin N. Arseni and his mentor, Prof. Dr. D. Bagdasar, are revered by later generations of doctors as the forefathers of Romanian neurosurgery. In 2012, we have celebrated 100 years since Prof. Arseni's birth in a small village within a deprived area of the country. Through his talents and perseveration, he rose to be a neurosurgical school creator and one of the most prominent figures in 20th-century Eastern European neurosurgery. This historical vignette is a modest tribute to his legacy and tells the story of his titanic endeavor.

  19. Experimental Measurement of the Four-Dimensional Coherence Function for an Undulator X-Ray Source

    NASA Astrophysics Data System (ADS)

    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.

  20. 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. PMID:22104742

  1. 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.

  2. 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. PMID:22015369

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

    PubMed

    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.

  4. The sitting position in neurosurgery: a critical appraisal.

    PubMed

    Porter, J M; Pidgeon, C; Cunningham, A J

    1999-01-01

    The potential for serious complications after venous air embolism and successful malpractice liability claims are the principle reasons for the dramatic decline in the use of the sitting position in neurosurgical practice. Although there have been several studies substantiating the relative safety compared with the prone or park bench positions, its use will continue to decline as neurosurgeons abandon its application and trainees in neurosurgery are not exposed to its relative merits. How can individual surgeons continue to use this position? Will individual, difficult surgical access cases be denied the obvious technical advantages of the sitting position? Limited use of the sitting position should remain in the neurosurgeon's armamentarium. However, several caveats must be emphasized. Assessment of the relative risk-benefit, based on the individual patient's physical status and surgical implications for the particular intracranial pathology, is of paramount importance. The patient should be informed of the specific risks of venous air embolism, quadriparesis and peripheral nerve palsies. Appropriate charting of patient information provided and special consent issues are essential. An anaesthetic input into the decision to use the sitting position is a sine qua non. The presence of a patient foramen ovale is an absolute contraindication. Preoperative contrast echocardiography should be used as a screening technique to detect the population at risk of paradoxical air embolism caused by the presence of a patent foramen ovale. The technique involves i.v. injection of saline agitated with air and a Valsalva manoeuvre is applied and released. Use of this position necessitates supplementary monitoring to promptly detect and treat venous air embolism. Doppler ultrasonography is the most sensitive of the generally available monitors to detect intracardiac air. The use of a central venous catheter is recommended, with the tip positioned close to the superior vena cava

  5. 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.

  6. The Mathematics of Three N-Localizers Used Together for Stereotactic Neurosurgery

    PubMed Central

    2015-01-01

    The N-localizer enjoys widespread use in image-guided stereotactic neurosurgery and radiosurgery. This article derives the mathematical equations that are used with three N-localizers and provides analogies, explanations, and appendices in order to promote a deeper understanding of the mathematical principles that govern the N-localizer. PMID:26594605

  7. 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.

  8. 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

  9. 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

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

    PubMed Central

    Lenn, Tchern; Leake, Mark C.

    2012-01-01

    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. PMID:22773951

  11. 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

  12. 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

  13. 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.

  14. Modeling of relay helix functional dynamics and feasibility of experimental verification by neutron scattering

    NASA Astrophysics Data System (ADS)

    Satarić, Miljko V.; Zdravković, Slobodan; Tuszyński, Jack A.

    2011-12-01

    Cellular long-range transport involves motor proteins (MPs) (especially, kinesin and myosin) which contain a so-called relay helix. Its motion is of crucial importance to the conversion of chemical energy released in ATP hydrolysis into the coordinated mechanical movement of the entire motor protein. In this paper, we propose two combined nonlinear mechanisms for this particular functional activity and suggest the application of neutron scattering assays to experimentally determine the incoherent dynamic structure factor S(q ,ω). We argue that this type of experiment is not only feasible but it could offer significant insights into the mechanism of MP function at a molecular level.

  15. Localization and socialization: Experimental insights into the functional architecture of IP3 receptors

    NASA Astrophysics Data System (ADS)

    Diambra, Luis; Marchant, Jonathan S.

    2009-09-01

    Inositol 1,4,5-trisphosphate (IP3)-evoked Ca2+ signals display great spatiotemporal malleability. This malleability depends on diversity in both the cellular organization and in situ functionality of IP3 receptors (IP3Rs) that regulate Ca2+ release from the endoplasmic reticulum (ER). Recent experimental data imply that these considerations are not independent, such that—as with other ion channels—the local organization of IP3Rs impacts their functionality, and reciprocally IP3R activity impacts their organization within native ER membranes. Here, we (i) review experimental data that lead to our understanding of the "functional architecture" of IP3Rs within the ER, (ii) propose an updated terminology to span the organizational hierarchy of IP3Rs observed in intact cells, and (iii) speculate on the physiological significance of IP3R socialization in Ca2+ dynamics, and consequently the emerging need for modeling studies to move beyond gridded, planar, and static simulations of IP3R clustering even over short experimental timescales.

  16. 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

  17. 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…

  18. Alfvénic oscillations of the electron distribution function: Linear theory and experimental measurements

    NASA Astrophysics Data System (ADS)

    Schroeder, J. W. R.; Skiff, F.; Howes, G. G.; Kletzing, C. A.; Carter, T. A.; Dorfman, S.

    2015-12-01

    Wave propagation can be an accurate method for determining material properties. High frequency whistler mode waves (0.7 < ω/|Ωce| < 1) in an overdense plasma (ωpe > |Ωce|) 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 - 10vte) 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.

  19. 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.

  20. Experimental evidence validating the computational inference of functional associations from gene fusion events: a critical survey

    PubMed Central

    Promponas, Vasilis J.; Ouzounis, Christos A.; Iliopoulos, Ioannis

    2014-01-01

    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. PMID:23220349

  1. 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.

  2. Numerical and experimental studies of enhanced electron emission from functionalized carbon nanotube emitters

    NASA Astrophysics Data System (ADS)

    Jin, Feng; Little, Scott; Alzubi, Feras

    2007-03-01

    Vertically aligned carbon nanotubes (CNTs) were grown using plasma enhanced chemical vapor deposition (PECVD) method. The CNTs were further functionalized by coating their surface with a thin layer of low work function oxide emissive materials. The electron emission capability of the coated CNT emitters was greatly improved with the low work function emissive layer, particularly at high temperature. Thermionic emission current three orders magnitude higher was observed. The emission properties of the oxide coated CNTs were measured and characterized over a wide temperature and field ranges. It was found that neither the Fowler-Nordheim theory for field emission nor the Richardson theory for thermionic emission were adequate to describe the electron emission characteristics of these emitters in certain range of temperature and field. However, by adopting a general electron emission formulism developed by Murphy and Good, we were able to simulate the electron emission from the coated CNTs over the whole temperature and field range and fit the experimental data.

  3. 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.

  4. Functional trade-offs increase species diversity in experimental plant communities.

    PubMed

    Ben-Hur, Eyal; Fragman-Sapir, Ori; Hadas, Rivka; Singer, Alon; Kadmon, Ronen

    2012-11-01

    Functional trade-offs have long been recognised as important mechanisms of species coexistence, but direct experimental evidence for such mechanisms is extremely rare. Here, we test the effect of one classical trade-off - a negative correlation between seed size and seed number - by establishing microcosm plant communities with positive, negative and no correlation between seed size and seed number and analysing the effect of the seed size/number correlation on species richness. Consistent with theory, a negative correlation between seed size and seed number led to a higher number of species in the communities and a corresponding wider range of seed size (a measure of functional richness) by promoting coexistence of large- and small-seeded species. Our study provides the first direct evidence that a seed size/number trade-off may contribute to species coexistence, and at a wider context, demonstrates the potential role of functional trade-offs in maintaining species diversity.

  5. 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. PMID:19522575

  6. An abrupt reduction in end-tidal carbon-dioxide during neurosurgery is not always due to venous air embolism: a capnograph artefact.

    PubMed

    Vinay, Byrappa; Sriganesh, Kamath; Gopala Krishna, Kadarapura Nanjundaiah

    2014-04-01

    Venous air embolism (VAE) is a well recognized complication during neurosurgery. Pre-cordial doppler and trans-esophageal echocardiography are sensitive monitors for the detection of VAE. A sudden, abrupt reduction in the end-tidal carbondioxide (ETCO2) pressure with associated hypotension during neurosurgery might suggest VAE, when more sensitive monitors are not available. We describe an unusual cause for sudden reduction in ETCO2 during neurosurgery and discuss the mechanism for such presentation. PMID:23996497

  7. Microelectromechanical systems and neurosurgery: a new era in a new millennium.

    PubMed

    Roy, S; Ferrara, L A; Fleischman, A J; Benzel, E C

    2001-10-01

    MICROMACHINES AND MICROELECTROMECHANICAL SYSTEMS (MEMS) are terms that are new to neurosurgeons but certain to become "household terms" in neurosurgery in the near future. These new terms serve as an introduction to a new world of sensors, actuators, and "smart systems" that will change the ways in which neurosurgeons interact with their environment. Through the use of microelectronics and micromachining technologies, MEMS will allow neurosurgeons to perform familiar tasks with greater precision, perform tasks that previously were not done at all, and monitor physiological and biochemical parameters more accurately and with greater safety. This review provides the information necessary to understand the fundamental concepts of MEMS and their application to the neurosurgical arena. It defines the relevant terms and describes the history behind the "micromachine revolution," the capabilities and limitations of MEMS technology, and how this revolution is germane to neurosurgery and to neurosurgeons.

  8. Impact of 20th Century Wars on the Development of Neurosurgery.

    PubMed

    Dowdy, Justin; Pait, T Glenn

    2016-01-01

    The treatment of neurosurgical casualties suffered during the wars of the 20th century had a significant impact on the formation and early growth of neurosurgery as a specialty. This chapter explores how the evolution of military tactics and weaponry along with the circumstances surrounding the wars themselves profoundly influenced the field. From the crystallization of intracranial projectile wound management and the formal recognition of the specialty itself arising from World War I experiences to the radical progress made in the outcomes of spinal-cord-injured soldiers in World War II or the fact that the neurosurgical training courses commissioned for these wars proved to be the precursors to modern neurosurgical training programs, the impact of the 20th century wars on the development of the field of neurosurgery is considerable.

  9. 100 Years of British military neurosurgery: on the shoulders of giants.

    PubMed

    Roberts, S A G

    2015-01-01

    Death from head injuries has been a feature of conflicts throughout the world for centuries. The burden of mortality has been variously affected by the evolution in weaponry from war-hammers to explosive ordnance, the influence of armour on survivability and the changing likelihood of infection as a complicating factor. Surgery evolved from haphazard trephination to valiant, yet disjointed, neurosurgery by a variety of great historical surgeons until the Crimean War of 1853-1856. However, it was events initiated by the Great War of 1914-1918 that not only marked the development of modern neurosurgical techniques, but our approach to military surgery as a whole. Here the author describes how 100 years of conflict and the input and intertwining relationships between the 20th century's great neurosurgeons established neurosurgery in the United Kingdom and beyond. PMID:26292388

  10. 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. PMID:26999913

  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. 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

  13. 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

  14. Diabetes insipidus following neurosurgery at a university hospital in Western Saudi Arabia

    PubMed Central

    Qari, Faiza A.; AbuDaood, Elaff A.; Nasser, Tariq A.

    2016-01-01

    Objectives: To review the incidence, spectrum of clinical manifestation, course, risk factors, as well as treatment of diabetes insipidus (DI) following neurosurgery of the pituitary gland. Methods: The files of 24 patients that underwent neurosurgery for sellar lesions, or tumor near the hypothalamus or pituitary gland at the Department of Neurosurgery, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia were retrospectively reviewed between January 2011 to December 2014. A total of 24 patients were studied, and were divided into 2 groups namely; DI and non-DI. Patient characteristics were studied using descriptive statistics. The differences in proportion between the 2 groups were found out using Z-test for proportion in 2 populations. The mean differences in the hormonal abnormalities for the 2 groups were assessed using independent t-test. All statistics are considered statistically significant when p<0.05. Results: During hospitalization, 13 (54.2%) out of 24 patient that underwent neurosurgery had manifestations of DI, which was transient in 5 (38.8%) and permanent in 8 (61.2%). The DI subgroup contained higher prevalence of prolactinoma, craniopharyngioma, pre-operative panhypopituitarism, and macroadenoma in MRI imaging and transphenoidal surgery. Furthermore, urine osmolality was significantly lower in the DI group post-operatively with a significant p=0.023. It was recognized that the permanent DI documented more significant numbers than other studies. Conclusion: In our study group, it was recognized that permanent DI meant that our patients needed desmopressin for more than 3 months, which documented a more significant number than other studies. PMID:26837398

  15. 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

  16. DIANA-miRPath v3.0: deciphering microRNA function with experimental support

    PubMed Central

    Vlachos, Ioannis S.; Zagganas, Konstantinos; Paraskevopoulou, Maria D.; Georgakilas, Georgios; Karagkouni, Dimitra; Vergoulis, Thanasis; Dalamagas, Theodore; Hatzigeorgiou, Artemis G.

    2015-01-01

    The functional characterization of miRNAs is still an open challenge. Here, we present DIANA-miRPath v3.0 (http://www.microrna.gr/miRPathv3) an online software suite dedicated to the assessment of miRNA regulatory roles and the identification of controlled pathways. The new miRPath web server renders possible the functional annotation of one or more miRNAs using standard (hypergeometric distributions), unbiased empirical distributions and/or meta-analysis statistics. DIANA-miRPath v3.0 database and functionality have been significantly extended to support all analyses for KEGG molecular pathways, as well as multiple slices of Gene Ontology (GO) in seven species (Homo sapiens, Mus musculus, Rattus norvegicus, Drosophila melanogaster, Caenorhabditis elegans, Gallus gallus and Danio rerio). Importantly, more than 600 000 experimentally supported miRNA targets from DIANA-TarBase v7.0 have been incorporated into the new schema. Users of DIANA-miRPath v3.0 can harness this wealth of information and substitute or combine the available in silico predicted targets from DIANA-microT-CDS and/or TargetScan v6.2 with high quality experimentally supported interactions. A unique feature of DIANA-miRPath v3.0 is its redesigned Reverse Search module, which enables users to identify and visualize miRNAs significantly controlling selected pathways or belonging to specific GO categories based on in silico or experimental data. DIANA-miRPath v3.0 is freely available to all users without any login requirement. PMID:25977294

  17. Neurosurgery at All India Institute of Medical Sciences, a center of excellence: A success story.

    PubMed

    Singh, Manmohan; Sawarkar, Dattaraj; Sharma, Bhawani S

    2015-01-01

    The department of neurosurgery at All India Institute of Medical Sciences (AIIMS) started its humble beginning in 1965. With the untiring and selfless hard work of Prof. P N Tandon and Prof. A K Banerji, the department progressed over time to become a center of excellence in the subcontinent. To establish a neurosciences center at AIIMS was an uphill task, which was accomplished with great efforts. The department has established itself as one of the highest centers of learning in the country with its vast infrastructure and diversity in all fields of neurosurgery. AIIMS, New Delhi was established by an act of the parliament in 1956. It was started with a grant from the Government of New Zealand under the "Colombo Plan." It was the vision of Rajkumari Amrita Kaur, the first Health Minister of India, that led to the establishment of a medical institute of international repute in India. AIIMS, New Delhi is an autonomous institute and is governed by the AIIMS Act, 1956. The department of neurosurgery at AIIMS was started in March 1965 with Prof. P.N. Tandon as the Head of the Department. Prof. A.K. Banerji joined him a few months later. The Department celebrated its golden jubilee in the year 2015, and has tremendously grown in stature from its humble beginnings to being a center of excellence with world-wide recognition. PMID:26238896

  18. Atrial natriuretic factor: is it responsible for hyponatremia and natriuresis in neurosurgery?

    PubMed Central

    Gasparotto, Ana Paula Devite Cardoso; Falcão, Antonio Luis Eiras; Kosour, Carolina; Araújo, Sebastião; Cintra, Eliane Araújo; de Oliveira, Rosmari Aparecida Rosa Almeida; Martins, Luiz Claudio; Dragosavac, Desanka

    2016-01-01

    Objective To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved. PMID:27410411

  19. The legacy of Prof. Constantin Arseni. The medical architect behind the Romanian School of Neurosurgery.

    PubMed

    Mohan, D; Husti, I Luca; Moisa, H; Ciurea, Av; Mult, H C

    2014-01-01

    The personality of Prof. Dr. Constantin Arseni (1912-1994) is without any doubt a key point in any discussion regarding the history of the Romanian School of Neurosurgery. Now at two decades since the regretted passing-away of Prof. Arseni the authors present several pieces of data regarding the early beginnings of neurosurgery in Romania and how this discipline has evolved over time in our country. Driven by an incredible tenacity Professor Constantin Arseni managed not only to create the first completely independent clinic of neurosurgery in Romania, but also to keep it continuously updated with the latest bibliographic and technological resources available at the time. Professor Arseni's masterpiece, the largest neurosurgical hospital in Europe (at the time of its construction)was supposed to be a completely autonomous institute dedicated to surgery on the human central nervous system. As the Iron Curtain fell and Europe was marked by continuous reforms, the idea of an institute dedicated to the brain was abandoned by the authorities and a multidisciplinary hospital dedicated to neurosurgical emergencies and trauma was born. PMID:25375064

  20. 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.

  1. 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. PMID:26621418

  2. Neurosurgery at All India Institute of Medical Sciences, a center of excellence: A success story.

    PubMed

    Singh, Manmohan; Sawarkar, Dattaraj; Sharma, Bhawani S

    2015-01-01

    The department of neurosurgery at All India Institute of Medical Sciences (AIIMS) started its humble beginning in 1965. With the untiring and selfless hard work of Prof. P N Tandon and Prof. A K Banerji, the department progressed over time to become a center of excellence in the subcontinent. To establish a neurosciences center at AIIMS was an uphill task, which was accomplished with great efforts. The department has established itself as one of the highest centers of learning in the country with its vast infrastructure and diversity in all fields of neurosurgery. AIIMS, New Delhi was established by an act of the parliament in 1956. It was started with a grant from the Government of New Zealand under the "Colombo Plan." It was the vision of Rajkumari Amrita Kaur, the first Health Minister of India, that led to the establishment of a medical institute of international repute in India. AIIMS, New Delhi is an autonomous institute and is governed by the AIIMS Act, 1956. The department of neurosurgery at AIIMS was started in March 1965 with Prof. P.N. Tandon as the Head of the Department. Prof. A.K. Banerji joined him a few months later. The Department celebrated its golden jubilee in the year 2015, and has tremendously grown in stature from its humble beginnings to being a center of excellence with world-wide recognition.

  3. 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

  4. Effects of experimental unilateral condylectomy followed by altered mandibular function on the maxilla and zygoma.

    PubMed

    Spyropoulos, M N; Tsolakis, A I; Katsavrias, E; Alexandridis, K

    1997-04-01

    The effect of protruded mandibular function on the maxilla and zygoma was studied in young unilaterally condylectomized growing rats. Forty-eight-4-week-old rats were divided into two experimental and two control groups as follows: group A, 12 animals unilaterally condylectomized on the right side; the mandible was allowed to function normally; group B, 12 animals unilaterally condylectomized on the right side; the mandible was protracted forwards immediately by means of an appliance; group C, 12 animals sham-operated on the right side; no condylectomy or mandibular protraction; and group d, 12 control animals not subjected to any operation or mandibular protraction. The mandibular protraction was achieved by an appliance consisting of an acrylic collar brace fitted to the animal's neck and supporting rubber bands pulling on an intraoral part cemented on the animal's lower incisors. Twenty-five grams of pulling force and protrusion to a clinically and radiographically testes anterior crossbite was exercised for 12 hours per day. The experimental period was 30 days. Lateral and dorsoventral radiographs were taken on days 1 and 30 following condylectomies and mandibular protraction. Cephalometric analysis was performed for each animal with measurements evaluating the maxilla and zygoma. Statistical analysis and comparison of the findings in the four groups of animals can be summarized as follows: (i) condylectomy and altered mandibular function may produce remote skeletal reactions in other parts of the cranial complex; and (ii) the ipsilateral maxilla is affected by condylectomy of the mandible, but altered mandibular function by protraction compensates for the results of condylectomy. PMID:9183070

  5. 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. PMID:21391432

  6. Imaging samples in silica aerogel using an experimental point spread function.

    PubMed

    White, Amanda J; Ebel, Denton S

    2015-02-01

    Light microscopy is a powerful tool that allows for many types of samples to be examined in a rapid, easy, and nondestructive manner. Subsequent image analysis, however, is compromised by distortion of signal by instrument optics. Deconvolution of images prior to analysis allows for the recovery of lost information by procedures that utilize either a theoretically or experimentally calculated point spread function (PSF). Using a laser scanning confocal microscope (LSCM), we have imaged whole impact tracks of comet particles captured in silica aerogel, a low density, porous SiO2 solid, by the NASA Stardust mission. In order to understand the dynamical interactions between the particles and the aerogel, precise grain location and track volume measurement are required. We report a method for measuring an experimental PSF suitable for three-dimensional deconvolution of imaged particles in aerogel. Using fluorescent beads manufactured into Stardust flight-grade aerogel, we have applied a deconvolution technique standard in the biological sciences to confocal images of whole Stardust tracks. The incorporation of an experimentally measured PSF allows for better quantitative measurements of the size and location of single grains in aerogel and more accurate measurements of track morphology.

  7. Imaging samples in silica aerogel using an experimental point spread function.

    PubMed

    White, Amanda J; Ebel, Denton S

    2015-02-01

    Light microscopy is a powerful tool that allows for many types of samples to be examined in a rapid, easy, and nondestructive manner. Subsequent image analysis, however, is compromised by distortion of signal by instrument optics. Deconvolution of images prior to analysis allows for the recovery of lost information by procedures that utilize either a theoretically or experimentally calculated point spread function (PSF). Using a laser scanning confocal microscope (LSCM), we have imaged whole impact tracks of comet particles captured in silica aerogel, a low density, porous SiO2 solid, by the NASA Stardust mission. In order to understand the dynamical interactions between the particles and the aerogel, precise grain location and track volume measurement are required. We report a method for measuring an experimental PSF suitable for three-dimensional deconvolution of imaged particles in aerogel. Using fluorescent beads manufactured into Stardust flight-grade aerogel, we have applied a deconvolution technique standard in the biological sciences to confocal images of whole Stardust tracks. The incorporation of an experimentally measured PSF allows for better quantitative measurements of the size and location of single grains in aerogel and more accurate measurements of track morphology. PMID:25517515

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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. PMID:26050707

  14. Effects of experimental cardiac volume loading on left atrial phasic function in healthy dogs.

    PubMed

    Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Nisa, Khoirun; Yokoyama, Nozomu; Sasaki, Noboru; Morishita, Keitaro; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

    2016-09-01

    OBJECTIVE To elucidate the relationship between acute volume overload and left atrial phasic function in healthy dogs. ANIMALS 6 healthy Beagles. PROCEDURES Dogs were anesthetized. A Swan-Ganz catheter was placed to measure mean pulmonary capillary wedge pressure (PCWP). Cardiac preload was increased by IV infusion with lactated Ringer solution at 150 mL/kg/h for 90 minutes. Transthoracic echocardiography was performed before (baseline) and at 15, 30, 45, 60, 75, and 90 minutes after volume loading began. At each echocardiographic assessment point, apical 4-chamber images were recorded and analyzed to derive time-left atrial area curves. Left atrial total (for reservoir function), passive (for conduit function), and active (for booster-pump function) fractional area changes were calculated from the curves. RESULTS Volume overload resulted in a significant increase from baseline in PCWP from 15 to 90 minutes after volume loading began. All fractional area changes at 15 to 90 minutes were significantly increased from baseline. In multiple regression analysis, quadratic regression models were better fitted to the relationships between PCWP and each of the total and active fractional area changes than were linear regression models. A linear regression model was better fitted to the relationship between PCWP and passive fractional area change. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that left atrial phasic function assessed on the basis of left atrial phasic areas was enhanced during experimental cardiac volume loading in healthy dogs. The effect of volume load should be considered when evaluating left atrial phasic function by indices derived from left atrial phasic sizes. PMID:27580106

  15. Sparing of muscle mass and function by passive loading in an experimental intensive care unit model.

    PubMed

    Renaud, Guillaume; Llano-Diez, Monica; Ravara, Barbara; Gorza, Luisa; Feng, Han-Zhong; Jin, Jian-Ping; Cacciani, Nicola; Gustafson, Ann-Marie; Ochala, Julien; Corpeno, Rebeca; Li, Meishan; Hedström, Yvette; Ford, G Charles; Nair, K Sreekumaran; Larsson, Lars

    2013-03-01

    The response to mechanical stimuli, i.e., tensegrity, plays an important role in regulating cell physiological and pathophysiological function, and the mechanical silencing observed in intensive care unit (ICU) patients leads to a severe and specific muscle wasting condition. This study aims to unravel the underlying mechanisms and the effects of passive mechanical loading on skeletal muscle mass and function at the gene, protein and cellular levels. A unique experimental rat ICU model has been used allowing long-term (weeks) time-resolved analyses of the effects of standardized unilateral passive mechanical loading on skeletal muscle size and function and underlying mechanisms. Results show that passive mechanical loading alleviated the muscle wasting and the loss of force-generation associated with the ICU intervention, resulting in a doubling of the functional capacity of the loaded versus the unloaded muscles after a 2-week ICU intervention. We demonstrate that the improved maintenance of muscle mass and function is probably a consequence of a reduced oxidative stress revealed by lower levels of carbonylated proteins, and a reduced loss of the molecular motor protein myosin. A complex temporal gene expression pattern, delineated by microarray analysis, was observed with loading-induced changes in transcript levels of sarcomeric proteins, muscle developmental processes, stress response, extracellular matrix/cell adhesion proteins and metabolism. Thus, the results from this study show that passive mechanical loading alleviates the severe negative consequences on muscle size and function associated with the mechanical silencing in ICU patients, strongly supporting early and intense physical therapy in immobilized ICU patients. PMID:23266938

  16. Acidity of the amidoxime functional group in aqueous solution. A combined experimental and computational study

    DOE PAGESBeta

    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 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

  17. 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.

  18. 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

  19. An experimental study of the accuracy in measurement of modulation transfer function using an edge method

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hoon; Kim, Ye-seul; Park, Hye-Suk; Lee, Young-Jin; Kim, Hee-Joung

    2015-03-01

    Image evaluation is necessary in digital radiography (DR) which is widely used in medical imaging. Among parameters of image evaluation, modulation transfer function (MTF) is the important factor in the field of medical imaging and necessary to obtain detective quantum efficiency (DQE) which represents overall performance of the detector signal-to-noise ratio. However, the accurate measurement of MTF is still not easy because of geometric effect, electric noise, quantum noise, and truncation error. Therefore, in order to improve accuracy of MTF, four experimental methods were tested in this study such as changing the tube current, applying smoothing method in edge spread function (ESF), adjusting line spread function (LSF) range, and changing tube angle. Our results showed that MTF's fluctuation was decreased by high tube current and smoothing method. However, tube current should not exceed detector saturation and smoothing in ESF causes a distortion in ESF and MTF. In addition, decreasing LSF range diminished fluctuation and the number of sampling in MTF and high tube angle generates degradation in MTF. Based on these results, excessively low tube current and the smoothing method should be avoided. Also, optimal range of LSF considering reduction of fluctuation and the number of sampling in MTF was necessary and precise tube angle is essential to obtain an accurate MTF. In conclusion, our results demonstrated that accurate MTF can be acquired.

  20. 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.

  1. Wild jujube polysaccharides protect against experimental inflammatory bowel disease by enabling enhanced intestinal barrier function.

    PubMed

    Yue, Yuan; Wu, Shuangchan; Li, Zhike; Li, Jian; Li, Xiaofei; Xiang, Jin; Ding, Hong

    2015-08-01

    Dietary polysaccharides provide various beneficial effects for our health. We investigated the protective effects of wild jujube (Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou) sarcocarp polysaccharides (WJPs) against experimental inflammatory bowel disease (IBD) by enabling enhanced intestinal barrier function. Colitis was induced in rats by the intrarectal administration of TNBS. We found that WJPs markedly ameliorated the colitis severity, including less weight loss, decreased disease activity index scores, and improved mucosal damage in colitis rats. Moreover, WJPs suppressed the inflammatory response via attenuation of TNF-α, IL-1β, IL-6 and MPO activity in colitis rats. And then, to determine the effect of WJPs on the intestinal barrier, we measured the effect of WJPs on the transepithelial electrical resistance (TER) and FITC-conjugated dextran permeability in Caco-2 cell stimulation with TNF-α. We further demonstrated that the alleviation of WJPs to colon injury was associated with barrier function by assembly of tight junction proteins. Moreover, the effect of WJPs on TER was eliminated by the specific inhibitor of AMPK. AMPK activity was also up-regulated by WJPs in Caco-2 cell stimulation with TNF-α and in colitis rats. This study demonstrates that WJPs protect against IBD by enabling enhanced intestinal barrier function involving the activation of AMPK.

  2. 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

  3. [Influence of prostatilen on smooth muscle organs functional activity in surgical patients (clinical and experimental study)].

    PubMed

    Al'-Shukri, S Kh; Aĭvazian, A I; Barabanov, S V; Barabanova, V V; Bobkov, Iu A; Gorbachev, A G; Parastaeva, M M

    1999-01-01

    The action of prostatilen on contractile activity of smooth muscles of isolated line slices of urine bladder of Wistar rats (myography) and arterial vessels of cat kidneys (resistography) was studied. On the basis of clinical cases effectiveness of prostatilen was analysed as a treatment restorting urine bladder function in acute reflex urinary retention after operations in the area of rectal sphincter, as well as in treatment of patients with chronic prostatitis. It is shown, that prostatilen produces contractile action on smooth muscles of renal blood vessels in cats and urine bladder walls in rats and it raises contractile activity of smooth muscles of human urine bladder. The results of experimental and clinical investigations make it possible to recommend the application of this bioregulating preparation for treatment and prophylaxis of disturbances in urination.

  4. Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function

    NASA Astrophysics Data System (ADS)

    Tung, Ryan C.; Killgore, Jason P.; Hurley, Donna C.

    2014-06-01

    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.

  5. Prediction and experimental confirmation of the response function for neutron detection using superheated drops

    NASA Astrophysics Data System (ADS)

    Lo, Yuan-Chyuan; Apfel, Robert E.

    1988-11-01

    Neutrons can be detected with a suspension of superheated drops in an immiscible and compliant holding medium. The mechanism of this radiation-induced bubble nucleation has been studied. A model to predict the minimum neutron energy required to nucleate a vapor bubble in superheated liquids has previously been reported [R.E. Apfel, S. C. Roy, and Y.-C. Lo, Phys. Rev. A 31, 3194 (1985)]. Now, the energy-dependent response function for the detector has been calculated based on the model and a detailed consideration of the possible interactions of neutrons with superheated materials. The response of the detector has been measured with monoenergetic neutrons (from 0.025 eV to 14 MeV) at facilities of the National Bureau of Standards and the Radiological Research Accelerator Facility at the Nevis Laboratories of Columbia University. The experimental results agree reasonably well with that of the calculations.

  6. Growth hormone and retinal ganglion cell function: QNR/D cells as an experimental model.

    PubMed

    Martínez-Moreno, Carlos; Andres, Alexis; Giterman, Daniel; Karpinski, Edward; Harvey, Steve

    2014-01-01

    Retinal ganglion cells (RGCs) have been shown to be sites of growth hormone (GH) production and GH action in the embryonic (embryo day 7, ED7) chick neural retina. Primary RGC cell cultures were previously used to determine autocrine or paracrine actions of GH in the retina, but the antibody used in their immunopanning (anti-Thy-1) is no longer available. We have therefore characterized an immortalized neural retina (QNR/D) cell line derived from ED7 embryonic quail as a replacement experimental model. These cells express the GH gene and have GH receptor (GHR)-immunoreactivity. They are also immunoreactive for RGC markers (islet-1, calretinin, RA4) and neural fibers (neurofilament, GAP 43, vimentin) and they express the genes for Thy-1, neurotrophin 3 (NTF3), neuritin 1 (NRN1) and brn3 (POU4F). These cells are also electrically active and therefore resemble the RGCs in the neural retina. They are also similarly responsive to exogenous GH, which induces overexpression of the neurotrophin 3 and insulin-like growth factor (IGF) 1 genes and stimulates cell survival, as in the chick embryo neural retina. QNR/D cells are therefore a useful experimental model to assess the actions of GH in retinal function. PMID:24239556

  7. 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.

  8. 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.

  9. 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

  10. Tiny giants of gene regulation: experimental strategies for microRNA functional studies.

    PubMed

    Steinkraus, Bruno R; Toegel, Markus; Fulga, Tudor A

    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. For further resources related to this article, please visit the WIREs website. PMID:26950183

  11. 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).

  12. Current Applications and Future Perspectives of the Use of 3D Printing in Anatomical Training and Neurosurgery

    PubMed Central

    Baskaran, Vivek; Štrkalj, Goran; Štrkalj, Mirjana; Di Ieva, Antonio

    2016-01-01

    3D printing is a form of rapid prototyping technology, which has led to innovative new applications in biomedicine. It facilitates the production of highly accurate three dimensional objects from substrate materials. The inherent accuracy and other properties of 3D printing have allowed it to have exciting applications in anatomy education and surgery, with the specialty of neurosurgery having benefited particularly well. This article presents the findings of a literature review of the Pubmed and Web of Science databases investigating the applications of 3D printing in anatomy and surgical education, and neurosurgery. A number of applications within these fields were found, with many significantly improving the quality of anatomy and surgical education, and the practice of neurosurgery. They also offered advantages over existing approaches and practices. It is envisaged that the number of useful applications will rise in the coming years, particularly as the costs of this technology decrease and its uptake rises. PMID:27445707

  13. Current Applications and Future Perspectives of the Use of 3D Printing in Anatomical Training and Neurosurgery.

    PubMed

    Baskaran, Vivek; Štrkalj, Goran; Štrkalj, Mirjana; Di Ieva, Antonio

    2016-01-01

    3D printing is a form of rapid prototyping technology, which has led to innovative new applications in biomedicine. It facilitates the production of highly accurate three dimensional objects from substrate materials. The inherent accuracy and other properties of 3D printing have allowed it to have exciting applications in anatomy education and surgery, with the specialty of neurosurgery having benefited particularly well. This article presents the findings of a literature review of the Pubmed and Web of Science databases investigating the applications of 3D printing in anatomy and surgical education, and neurosurgery. A number of applications within these fields were found, with many significantly improving the quality of anatomy and surgical education, and the practice of neurosurgery. They also offered advantages over existing approaches and practices. It is envisaged that the number of useful applications will rise in the coming years, particularly as the costs of this technology decrease and its uptake rises.

  14. Current Applications and Future Perspectives of the Use of 3D Printing in Anatomical Training and Neurosurgery.

    PubMed

    Baskaran, Vivek; Štrkalj, Goran; Štrkalj, Mirjana; Di Ieva, Antonio

    2016-01-01

    3D printing is a form of rapid prototyping technology, which has led to innovative new applications in biomedicine. It facilitates the production of highly accurate three dimensional objects from substrate materials. The inherent accuracy and other properties of 3D printing have allowed it to have exciting applications in anatomy education and surgery, with the specialty of neurosurgery having benefited particularly well. This article presents the findings of a literature review of the Pubmed and Web of Science databases investigating the applications of 3D printing in anatomy and surgical education, and neurosurgery. A number of applications within these fields were found, with many significantly improving the quality of anatomy and surgical education, and the practice of neurosurgery. They also offered advantages over existing approaches and practices. It is envisaged that the number of useful applications will rise in the coming years, particularly as the costs of this technology decrease and its uptake rises. PMID:27445707

  15. 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.

  16. 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

    Zeolites are important industrial catalysts with porous three-dimensional structures. The catalytically active sites are located inside the pores, thus rendering them inaccessible for surface science measurements. We synthesized a two-dimensional (2D) zeolite model system, consisting of an (alumino)silicate bilayer weakly bound to a Ru (0001) surface. The 2D zeolite is suitable for surface science studies; it allows a detailed characterization of the atomic structure of the active site and interrogation of the model system during the catalytic reaction. As an initial step, we use Ar adsorption to obtain a better understanding of the atomic structure of the 2D zeolite. In addition, atomic level studies of rare gas adsorption and separation by zeolite are important for its potential application in nuclear waste sequestration. Experimental studies found that Ar atoms can be trapped inside the 2D-zeolite, raising an interesting question on whether Ar atoms are trapped inside the hexagonal prism nano-cages or at the interface between the (alumino)silicate bilayer and Ru(0001), or both. DFT calculations using van der Waals density functionals were carried out to determine the preferred Ar adsorption sites and the corresponding adsorption energies. This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704.

  17. Experimental Removal and Recovery of Subtidal Grazers Highlights the Importance of Functional Redundancy and Temporal Context

    PubMed Central

    Elahi, Robin; Sebens, Kenneth P.

    2013-01-01

    The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus) on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp.) are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75%) relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context. PMID:24250819

  18. Experimental removal and recovery of subtidal grazers highlights the importance of functional redundancy and temporal context.

    PubMed

    Elahi, Robin; Sebens, Kenneth P

    2013-01-01

    The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus) on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp.) are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75%) relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context.

  19. Experimental removal and recovery of subtidal grazers highlights the importance of functional redundancy and temporal context.

    PubMed

    Elahi, Robin; Sebens, Kenneth P

    2013-01-01

    The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus) on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp.) are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75%) relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context. PMID:24250819

  20. The Head Injury Transportation Straight to Neurosurgery (HITS-NS) randomised trial: a feasibility study.

    PubMed Central

    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

    BACKGROUND 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. METHODS 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). PRIMARY OUTCOMES 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. RESULTS 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

  1. Pixel response function experimental techniques and analysis of active pixel sensor star cameras

    NASA Astrophysics Data System (ADS)

    Fumo, Patrick; Waldron, Erik; Laine, Juha-Pekka; Evans, Gary

    2015-04-01

    The pixel response function (PRF) of a pixel within a focal plane is defined as the pixel intensity with respect to the position of a point source within the pixel. One of its main applications is in the field of astrometry, which is a branch of astronomy that deals with positioning data of a celestial body for tracking movement or adjusting the attitude of a spacecraft. Complementary metal oxide semiconductor (CMOS) image sensors generally offer better radiation tolerance to protons and heavy ions than CCDs making them ideal candidates for space applications aboard satellites, but like all image sensors they are limited by their spatial frequency response, better known as the modulation transfer function. Having a well-calibrated PRF allows us to eliminate some of the uncertainty in the spatial response of the system providing better resolution and a more accurate centroid estimation. This paper describes the experimental setup for determining the PRF of a CMOS image sensor and analyzes the effect on the oversampled point spread function (PSF) of an image intensifier, as well as the effects due to the wavelength of light used as a point source. It was found that using electron bombarded active pixel sensor (EBAPS) intensification technology had a significant impact on the PRF of the camera being tested as a result of an increase in the amount of carrier diffusion between collection sites generated by the intensification process. Taking the full width at half maximum (FWHM) of the resulting data, it was found that the intensified version of a CMOS camera exhibited a PSF roughly 16.42% larger than its nonintensified counterpart.

  2. Dose-dependent functionality and toxicity of green tea polyphenols in experimental rodents.

    PubMed

    Murakami, Akira

    2014-09-01

    A large number of physiologically functional foods are comprised of plant polyphenols. Their antioxidative activities have been intensively studied for a long period and proposed to be one of the major mechanisms of action accounting for their health promotional and disease preventive effects. Green tea polyphenols (GTPs) are considered to possess marked anti-oxidative properties and versatile beneficial functions, including anti-inflammation and cancer prevention. On the other hand, some investigators, including us, have uncovered their toxicity at high doses presumably due to pro-oxidative properties. For instance, both experimental animal studies and epidemiological surveys have demonstrated that GTPs may cause hepatotoxicity. We also recently showed that diets containing high doses (0.5-1%) of a GTP deteriorated dextran sodium sulfate (DSS)-induced intestinal inflammation and carcinogenesis. In addition, colitis mode mice fed a 1% GTP exhibited symptoms of nephrotoxicity, as indicated by marked elevation of serum creatinine level. This diet also increased thiobarbituric acid-reactive substances, a reliable marker of oxidative damage, in both kidneys and livers even in normal mice, while the expression levels of antioxidant enzymes and heat shock proteins (HSPs) were diminished in colitis and normal mice. Intriguingly, GTPs at 0.01% and 0.1% showed hepato-protective activities, i.e., they significantly suppressed DSS-increased serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, those diets remarkably restored DSS-down-regulated expressions of heme oxygenase-1 and HSP70 in livers and kidneys. Taken together, while low and medium doses of GTPs are beneficial in colitis model mice, unwanted side-effects occasionally emerge with high doses. This dose-dependent functionality and toxicity of GTPs are in accordance with the concept of hormesis, in which mild, but not severe, stress activates defense systems for adaptation and survival.

  3. Effect of melatonin on the functional recovery from experimental traumatic compression of the spinal cord

    PubMed Central

    Schiaveto-de-Souza, A.; da-Silva, C.A.; Defino, H.L.A.; Bel, E.A.Del

    2013-01-01

    Spinal cord injury is an extremely severe condition with no available effective therapies. We examined the effect of melatonin on traumatic compression of the spinal cord. Sixty male adult Wistar rats were divided into three groups: sham-operated animals and animals with 35 and 50% spinal cord compression with a polycarbonate rod spacer. Each group was divided into two subgroups, each receiving an injection of vehicle or melatonin (2.5 mg/kg, intraperitoneal) 5 min prior to and 1, 2, 3, and 4 h after injury. Functional recovery was monitored weekly by the open-field test, the Basso, Beattie and Bresnahan locomotor scale and the inclined plane test. Histological changes of the spinal cord were examined 35 days after injury. Motor scores were progressively lower as spacer size increased according to the motor scale and inclined plane test evaluation at all times of assessment. The results of the two tests were correlated. The open-field test presented similar results with a less pronounced difference between the 35 and 50% compression groups. The injured groups presented functional recovery that was more evident in the first and second weeks. Animals receiving melatonin treatment presented more pronounced functional recovery than vehicle-treated animals as measured by the motor scale or inclined plane. NADPH-d histochemistry revealed integrity of the spinal cord thoracic segment in sham-operated animals and confirmed the severity of the lesion after spinal cord narrowing. The results obtained after experimental compression of the spinal cord support the hypothesis that melatonin may be considered for use in clinical practice because of its protective effect on the secondary wave of neuronal death following the primary wave after spinal cord injury. PMID:23579633

  4. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust.

    PubMed Central

    Rudell, B; Ledin, M C; Hammarström, U; Stjernberg, N; Lundbäck, B; Sandström, T

    1996-01-01

    OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Exposure to diesel exhaust caused symptoms and bronchoconstriction which were not significantly reduced by a particle trap. PMID:8943829

  5. The functions of self-injurious behavior: an experimental-epidemiological analysis.

    PubMed

    Iwata, B A; Pace, G M; Dorsey, M F; Zarcone, J R; Vollmer, T R; Smith, R G; Rodgers, T A; Lerman, D C; Shore, B A; Mazalesk, J L

    1994-01-01

    Data are summarized from 152 single-subject analyses of the reinforcing functions of self-injurious behavior (SIB). Individuals with developmental disabilities referred for assessment and/or treatment over an 11-year period were exposed to a series of conditions in which the effects of antecedent and consequent events on SIB were examined systematically by way of multielement, reversal, or combined designs. Data were collected during approximately 4,000 experimental sessions (1,000 hr), with the length of assessment for individuals ranging from 8 to 66 sessions (M = 26.2) conducted over 2 to 16.5 hr (M = 6.5). Differential or uniformly high responding was observed in 145 (95.4%) of the cases. Social-negative reinforcement (escape from task demands or other sources of aversive stimulation) accounted for 58 cases, which was the largest proportion of the sample (38.1%). Social-positive reinforcement (either attention or access to food or materials) accounted for 40 (26.3%) of the cases, automatic (sensory) reinforcement accounted for 39 (25.7%), and multiple controlling variables accounted for 8 (5.3%). Seven sets of data (4.6%) showed either cyclical or inconsistent patterns of responding that were uninterpretable. Overall results indicated that functional analysis methodologies are extremely effective in identifying the environmental determinants of SIB on an individual basis and, subsequently, in guiding the process of treatment selection. Furthermore, an accumulation of assessment data from such analyses across a large number of individuals provides perhaps the most rigorous approach to an epidemiological study of behavioral function.

  6. 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

  7. 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

  8. Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery

    PubMed Central

    Miga, Michael I.

    2016-01-01

    With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications. PMID:26354118

  9. Innovation in Neurosurgery: Intellectual Property Strategy and Academia/Industrial Collaboration.

    PubMed

    Murayama, Yuichi

    2016-09-15

    Neurosurgery has tremendous possibilities for development of innovative medical devices. However, most of the neurosurgical devices used in Japan are imported products. Promotion and development of domestic medical devices is highly encouraged and it is one of the pillars of Prime Minister Shinzo Abe's growth strategy of Japanese economy. Innovative "Made in Japan" medical devices can be developed by interdisciplinary collaboration between industries and academic institutions. Proper orientation of medical and engineering education, social and administrative awareness of the need of facilitating the medical devices creative process with corresponding regulatory changes, and appropriate medical and technological infrastructure establishment are needed for stimulating medical device innovation.

  10. [The processing of point clouds for brain deformation existing in image guided neurosurgery system].

    PubMed

    Yao, Xufeng; Lin, Yixun; Song, Zhijian

    2008-08-01

    The finite element method (FEM) plays an important role in solving the brain deformation problem in the image guided neurosurgery system. The position of the brain cortex during the surgery provides the boundary condition for the FEM model. In this paper, the information of brain cortex is represented by the unstructured points and the boundary condition is achieved by the processing of unstructured points. The processing includes the mapping of texture, segmentation, simplification and denoising. The method of k-nearest clustering based on local surface properties is used to simplify and denoise the unstructured point clouds. The results of experiment prove the efficiency of point clouds processing.

  11. Innovation in Neurosurgery: Intellectual Property Strategy and Academia/Industrial Collaboration.

    PubMed

    Murayama, Yuichi

    2016-09-15

    Neurosurgery has tremendous possibilities for development of innovative medical devices. However, most of the neurosurgical devices used in Japan are imported products. Promotion and development of domestic medical devices is highly encouraged and it is one of the pillars of Prime Minister Shinzo Abe's growth strategy of Japanese economy. Innovative "Made in Japan" medical devices can be developed by interdisciplinary collaboration between industries and academic institutions. Proper orientation of medical and engineering education, social and administrative awareness of the need of facilitating the medical devices creative process with corresponding regulatory changes, and appropriate medical and technological infrastructure establishment are needed for stimulating medical device innovation. PMID:27298262

  12. Innovation in Neurosurgery: Intellectual Property Strategy and Academia/Industrial Collaboration

    PubMed Central

    MURAYAMA, Yuichi

    2016-01-01

    Neurosurgery has tremendous possibilities for development of innovative medical devices. However, most of the neurosurgical devices used in Japan are imported products. Promotion and development of domestic medical devices is highly encouraged and it is one of the pillars of Prime Minister Shinzo Abe’s growth strategy of Japanese economy. Innovative “Made in Japan” medical devices can be developed by interdisciplinary collaboration between industries and academic institutions. Proper orientation of medical and engineering education, social and administrative awareness of the need of facilitating the medical devices creative process with corresponding regulatory changes, and appropriate medical and technological infrastructure establishment are needed for stimulating medical device innovation. PMID:27298262

  13. Kenneth Grant Jamieson (1925-1976): his life and contributions to neurosurgery.

    PubMed

    Mortazavi, Martin; Deep, Aman; Tubbs, R Shane; Fisher, Wink S

    2012-02-01

    Manuscript submitted May 23, 2011. Accepted September 25, 2011. Kenneth Grant Jamieson is celebrated as one of Australia's top neurosurgeons. His most notable contributions to neurosurgery included novel treatments of aneurysms and pineal tumors and studies of head injury. Jamieson was also an innovator for the development of new neurosurgical instruments and renowned for his teaching abilities, prolificacy, and mentorship. This preeminent neurosurgeon's life was cut short at the age of 51. Our current understanding and knowledge of treatments of various neurosurgical diseases is based on pioneers such as Kenneth Grant Jamieson.

  14. Intrinsic functional connectivity of insular cortex and symptoms of sickness during acute experimental inflammation.

    PubMed

    Lekander, Mats; Karshikoff, Bianka; Johansson, Emilia; Soop, Anne; Fransson, Peter; Lundström, Johan N; Andreasson, Anna; Ingvar, Martin; Petrovic, Predrag; Axelsson, John; Nilsonne, Gustav

    2016-08-01

    Task-based fMRI has been used to study the effects of experimental inflammation on the human brain, but it remains unknown whether intrinsic connectivity in the brain at rest changes during a sickness response. Here, we investigated the effect of experimental inflammation on connectivity between areas relevant for monitoring of bodily states, motivation, and subjective symptoms of sickness. In a double-blind randomized controlled experiment, 52 healthy volunteers were injected with 0.6ng/kg LPS (lipopolysaccharide) or placebo, and participated in a resting state fMRI experiment after approximately 2h 45min. Resting state fMRI data were available from 48 participants, of which 28 received LPS and 20 received placebo. Bilateral anterior and bilateral posterior insula sections were used as seed regions and connectivity with bilateral orbitofrontal and cingulate (anterior and middle) cortices was investigated. Back pain, headache and global sickness increased significantly after as compared to before LPS, while a non-significant trend was shown for increased nausea. Compared to placebo, LPS was followed by increased connectivity between left anterior insula and left midcingulate cortex. This connectivity was significantly correlated to increase in back pain after LPS and tended to be related to increased global sickness, but was not related to increased headache or nausea. LPS did not affect the connectivity from other insular seeds. In conclusion, the finding of increased functional connectivity between left anterior insula and middle cingulate cortex suggests a potential neurophysiological mechanism that can be further tested to understand the subjective feeling of malaise and discomfort during a sickness response. PMID:26732827

  15. Experimental implementation of the Deutsch-Jozsa algorithm for three-qubit functions using pure coherent molecular superpositions

    SciTech Connect

    Vala, Jiri; Kosloff, Ronnie; Amitay, Zohar; Zhang Bo; Leone, Stephen R.

    2002-12-01

    The Deutsch-Jozsa algorithm is experimentally demonstrated for three-qubit functions using pure coherent superpositions of Li{sub 2} rovibrational eigenstates. The function's character, either constant or balanced, is evaluated by first imprinting the function, using a phase-shaped femtosecond pulse, on a coherent superposition of the molecular states, and then projecting the superposition onto an ionic final state, using a second femtosecond pulse at a specific time delay.

  16. 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.

  17. 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

  18. Gastric vagal motoneuron function is maintained following experimental spinal cord injury

    PubMed Central

    Swartz, Emily M.; Holmes, Gregory M.

    2014-01-01

    Background: Clinical reports indicate that spinal cord injury (SCI) initiates profound gastric dysfunction. Gastric reflexes involve stimulation of sensory vagal fibers, which engage brainstem circuits that modulate efferent output back to the stomach, thereby completing the vago-vagal reflex. Our recent studies in a rodent model of experimental high thoracic (T3-) SCI suggest that reduced vagal afferent sensitivity to gastrointestinal (GI) stimuli may be responsible for diminished gastric function. Nevertheless, derangements in efferent signals from the dorsal motor nucleus of the vagus (DMV) to the stomach may also account for reduced motility. Methods: We assessed the anatomical, neurophysiological and functional integrity of gastric-projecting DMV neurons in T3-SCI rats using: 1) retrograde labeling of gastric-projecting DMV neurons; 2) whole cell recordings from gastric-projecting neurons of the DMV; and, 3) in vivo measurements of gastric contractions following unilateral microinjection of thyrotropin releasing hormone (TRH) into the DMV. Key Results: Immunohistochemical analysis of gastric-projecting DMV neurons demonstrated no difference between control and T3-SCI rats. Whole cell in vitro recordings showed no alteration in DMV membrane properties and the neuronal morphology of these same, neurobiotin-labeled, DMV neurons were unchanged after T3-SCI with regard to cell size and dendritic arborization. Central microinjection of TRH induced a significant facilitation of gastric contractions in both control and T3-SCI rats and there were no significant dose-dependent differences between groups. Conclusions: Our data suggest that the acute, 3 day to 1 week post-SCI, dysfunction of vagally-mediated gastric reflexes do not include derangements in the efferent DMV motoneurons. PMID:25316513

  19. Experimental demonstrations of all-optical networking functions for WDM optical networks

    NASA Astrophysics Data System (ADS)

    Gurkan, Deniz

    The deployment of optical networks will enable high capacity links between users but will introduce the problems associated with transporting and managing more channels. Many network functions should be implemented in optical domain; main reasons are: to avoid electronic processing bottlenecks, to achieve data-format and data-rate independence, to provide reliable and cost efficient control and management information, to simultaneously process multiple wavelength channel operation for wavelength division multiplexed (WDM) optical networks. The following novel experimental demonstrations of network functions in the optical domain are presented: Variable-bit-rate recognition of the header information in a data packet. The technique is reconfigurable for different header sequences and uses optical correlators as look-up tables. The header is processed and a signal is sent to the switch for a series of incoming data packets at 155 Mb/s, 622 Mb/s, and 2.5 Gb/s in a reconfigurable network. Simultaneous optical time-slot-interchange and wavelength conversion of the bits in a 2.5-Gb/s data stream to achieve a reconfigurable time/wavelength switch. The technique uses difference-frequency-generation (DFG) for wavelength conversion and fiber Bragg gratings (FBG) as wavelength-dependent optical time buffers. The WDM header recognition module simultaneously recognizing two header bits on each of two 2.5-Gbit/s WDM packet streams. The module is tunable to enable reconfigurable look-up tables. Simultaneous and independent label swapping and wavelength conversion of two WDM channels for a multi-protocol label switching (MPLS) network. Demonstration of label swapping of distinct 8-bit-long labels for two WDM data channels is presented. Two-dimensional code conversion module for an optical code-division multiple-access (O-CDMA) local area network (LAN) system. Simultaneous wavelength conversion and time shifting is achieved to enable flexible code conversion and increase code re

  20. Quality control and assurance in functional near infrared spectroscopy (fNIRS) experimentation

    NASA Astrophysics Data System (ADS)

    Orihuela-Espina, F.; Leff, D. R.; James, D. R. C.; Darzi, A. W.; Yang, G. Z.

    2010-07-01

    Functional near infrared spectroscopy (fNIRS) is a rapidly developing neuroimaging modality for exploring cortical brain behaviour. Despite recent advances, the quality of fNIRS experimentation may be compromised in several ways: firstly, by altering the optical properties of the tissues encountered in the path of light; secondly, through adulteration of the recovered biological signals (noise) and finally, by modulating neural activity. Currently, there is no systematic way to guide the researcher regarding these factors when planning fNIRS studies. Conclusions extracted from fNIRS data will only be robust if appropriate methodology and analysis in accordance with the research question under investigation are employed. In order to address these issues and facilitate the quality control process, a taxonomy of factors influencing fNIRS data have been established. For each factor, a detailed description is provided and previous solutions are reviewed. Finally, a series of evidence-based recommendations are made with the aim of improving consistency and quality of fNIRS research.

  1. Experimental Modification of Rat Pituitary Prolactin Cell Function During and After Spaceflight

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.; Salada, T.; Avery, L.; Grindeland, R. E.

    1996-01-01

    Experimental modification of rat pituitary prolactin cell function during and after spaceflight. This study was done to evaluate the effects of microgravity on prolactin (PRL) cells of the male rat pituitary gland. We used the identical passive closed-vial cell culture system that was described for the culture of growth hormone cells (W C. Hymer, R. E. Grindeland, T. Salada, P. Nye, E. Grossman, and R Lane). After an 8-day spaceflight, all flight media (containing released PRL), as well as extracts (containing intracellular PRL), contained significantly lower amounts of immunoreactive PRL than their corresponding ground control samples. On the other hand, these same samples, when assessed for their biological activities by two different in vitro lymphocyte assays, yielded disparate results that may reflect posttranslational modifications to the hormone molecule. Other data showed that: (1) the apparent molecular weights of released PRL molecules were not altered by microgravity; but (2) the region from which the PRL cells came (dorsal or ventral) made a significant difference in the amount and activity of PRL released from the flight cells. Because there is much current interest in the role that PRL may play in the regulation of the immune system and because changes in both cellular and humoral immunity accompany spaceflight, this study could help define future microgravity research in this area.

  2. Laryngeal Adductor Function in Experimental Models of Recurrent Laryngeal Nerve Injury

    PubMed Central

    Paniello, Randal C.; Rich, Jason T.; Debnath, Nick L.

    2014-01-01

    Objectives/Hypothesis Most patients with unilateral vocal fold paralysis experience some degree of spontaneous reinnervation, which depends upon the type and severity of recurrent laryngeal nerve (RLN) injury. After partial recovery, the paretic vocal fold may or may not adduct adequately to allow glottic closure, which in turn affects phonatory and swallowing outcomes. This process was studied in a series of canine laryngeal nerve injury models. Study Design Animal (canine) experiments. Methods Maximum stimulable laryngeal adductor pressure (LAP) was measured pre-treatment (baseline) and at 6 months following experimental RLN injuries (total n=59). The 9 study groups were designed to simulate a range of severities of RLN injury. Results The greatest LAP recovery, at 108% of original baseline, was seen in a 50% transection model; the least recovery was seen when the RLN underwent complete transection with repair, at 56% with precise alignment and 50% with alignment reversed. Intermediate models (partial RLN injuries) gave intermediate results. Crush models recovered 105% of LAP, while a half-transection, half-crush injury recovered 72% and cautery injuries recovered 61%. Controls (complete transection without repair) had no measurable recovery. Conclusions The injured RLN has a strong tendency to recover. Restoration of adductor strength, as determined by the LAP, was predictably related to the severity of RLN injury. The model RLN injuries studied provide a range of expected outcomes that can be used for future experiments exploring interventions that may improve post-injury adductor function. PMID:25283381

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

    PubMed Central

    Best, John R.

    2011-01-01

    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 exercise benefit executive function equally: Cognitively-engaging exercise appears to have a stronger effect than non-engaging exercise on children’s executive function. This review discusses this evidence as well as the mechanisms that may underlie the association between exercise and executive function. Research from a variety of disciplines is covered, including developmental psychology, kinesiology, cognitive neuroscience, and biopsychology. Finally, these experimental findings are placed within the larger context of known links between action and cognition in infancy and early childhood, and the clinical and practical implications of this research are discussed. PMID:21818169

  4. [Suspected case of postoperative malignant hyperthermia treated with dantrolene one week after neurosurgery].

    PubMed

    Itoh, Kazushi; Nishibe, Shinichi; Usuda, Yutaka; Kitamura, Akira

    2014-10-01

    We report the case of a 16-year-old man who presented with hyperthermia (>40°C), an elevated creatine kinase level (>64,000 IU · l-1), and myoglobinuria one week after undergoing two successive neurosurgeries for a brain hemorrhage under sevoflurane anesthesia. After having been diagnosed with suspicious atypical postoperative malignant hyperthermia, he was treated with dantrolene and his symptoms disappeared on the day of dantrolene administration. Central hyperthermia is defined as hyperthermia associated with thermoregulatory dysfunction after brainstem injury. Postoperative malignant hyperthermia can sometimes be difficult to distinguish from central hyperthermia, especially after neurosurgery. We could not eliminate the possibility of central hyperthermia as a cause of hyperthermia in the present patient If marked postoperative hyperthermia must be addressed immediately and managed appropriately in neurosurgical patients and dantrolene having few serious side effects, we were able to control his symptoms immediately after the infusion of dantrolene. Therefore, the administration of dantrolene should be considered when treating unidentified postoperative hyperthermia after a neurosurgical procedure. PMID:25693350

  5. Effects of intraoperative magnetic resonance imaging on the neuromuscular blockade of vecuronium bromide in neurosurgery.

    PubMed

    Guo, Ying; Zhang, Hong; Sun, Li

    2013-01-01

    The effects of intraoperative magnetic resonance (iMR) imaging on the neuromuscular blockade of vecuronium bromide were investigated in neurosurgery. Fifty patients with American Society of Anesthesiologists grades I-II scheduled for craniotomy operation were divided into two groups (n = 25 each) with no difference in demographic data: the iMR imaging group and control group. Train-of-four (TOF) stimulation through an accelerometer was used to monitor onset, maintenance, and recovery of muscle relaxation caused by vecuronium. Vecuronium bromide was intravenously injected after anesthesia induction. The dosage of vecuronium bromide in the iMR imaging group was larger than in the control group, but not significantly. Duration of vecuronium bromide administration and operation time were significantly longer in the iMR imaging group than in the control group. Time from drug discontinuation to operation termination, and to return to neurosurgery intensive care unit were not different. Time taken by first twitch (T1) in response to TOF stimulation to recover by 25%, and muscle relaxant recovery index were significantly greater in the control group than in the iMR imaging group. The body temperature of the patients increased gradually in the iMR imaging group but decreased in the control group. iMR imaging can prolong the operation time, increase the body temperature of the patient, and remarkably shorten the clinical action time and muscle relaxation recovery index of vecuronium.

  6. The beginnings of neurosurgery in California during the pre-Cushing era: 1850-1900.

    PubMed

    Keller, T M

    1998-11-01

    The end of the present millennium marks the centennial of Harvey Cushing's European study year, after the completion of his surgical residency under William Stewart Halsted at the Johns Hopkins Hospital and just before beginning his surgical practice in Baltimore, Maryland. The year 2000 marks the sesquicentennial of California's admission to the Union as the 31st state. This report documents a number of the events and achievements that occurred during this "pre-Cushing era" (1850-1900) that contributed to the ultimate development of neurological surgery in California. The historical milestones of the California gold rush, the completion of the Transcontinental Railroad across the Sierra Nevada Mountains, and the careers of early California physicians and educators, including those of Hugh Toland and Levi Cooper Lane, were instrumental in building a foundation for the modern discipline of neurosurgery in the Golden State. This foundation would serve as a cornerstone for surgeons trained by Harvey Cushing (including Howard Naffziger, Carl Rand, and Edward Towne) who would arrive in California early in the 20th century and would define the specialty of neurosurgery. The legacy left by these physicians enhances the celebration of the closure of the millennium.

  7. da Vinci robot-assisted keyhole neurosurgery: a cadaver study on feasibility and safety.

    PubMed

    Marcus, Hani J; Hughes-Hallett, Archie; Cundy, Thomas P; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar

    2015-04-01

    The goal of this cadaver study was to evaluate the feasibility and safety of da Vinci robot-assisted keyhole neurosurgery. Several keyhole craniotomies were fashioned including supraorbital subfrontal, retrosigmoid and supracerebellar infratentorial. In each case, a simple durotomy was performed, and the flap was retracted. The da Vinci surgical system was then used to perform arachnoid dissection towards the deep-seated intracranial cisterns. It was not possible to simultaneously pass the 12-mm endoscope and instruments through the keyhole craniotomy in any of the approaches performed, limiting visualization. The articulated instruments provided greater dexterity than existing tools, but the instrument arms could not be placed in parallel through the keyhole craniotomy and, therefore, could not be advanced to the deep cisterns without significant clashing. The da Vinci console offered considerable ergonomic advantages over the existing operating room arrangement, allowing the operating surgeon to remain non-sterile and seated comfortably throughout the procedure. However, the lack of haptic feedback was a notable limitation. In conclusion, while robotic platforms have the potential to greatly enhance the performance of transcranial approaches, there is strong justification for research into next-generation robots, better suited to keyhole neurosurgery.

  8. da Vinci robot-assisted keyhole neurosurgery: a cadaver study on feasibility and safety.

    PubMed

    Marcus, Hani J; Hughes-Hallett, Archie; Cundy, Thomas P; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar

    2015-04-01

    The goal of this cadaver study was to evaluate the feasibility and safety of da Vinci robot-assisted keyhole neurosurgery. Several keyhole craniotomies were fashioned including supraorbital subfrontal, retrosigmoid and supracerebellar infratentorial. In each case, a simple durotomy was performed, and the flap was retracted. The da Vinci surgical system was then used to perform arachnoid dissection towards the deep-seated intracranial cisterns. It was not possible to simultaneously pass the 12-mm endoscope and instruments through the keyhole craniotomy in any of the approaches performed, limiting visualization. The articulated instruments provided greater dexterity than existing tools, but the instrument arms could not be placed in parallel through the keyhole craniotomy and, therefore, could not be advanced to the deep cisterns without significant clashing. The da Vinci console offered considerable ergonomic advantages over the existing operating room arrangement, allowing the operating surgeon to remain non-sterile and seated comfortably throughout the procedure. However, the lack of haptic feedback was a notable limitation. In conclusion, while robotic platforms have the potential to greatly enhance the performance of transcranial approaches, there is strong justification for research into next-generation robots, better suited to keyhole neurosurgery. PMID:25516094

  9. [The robotization of neurosurgery: state of the art and future outlook].

    PubMed

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

    1997-11-01

    Neurosurgery is by excellence a field of application for robots, based on multimodal image guidance. Specific motorized tools have been already 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 currently commercially available. These systems use data bases, 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 preplanned, then transferred to the robotic systems to which they are connected. We have been using a stereotactic robot since 1989 and a microscope robot since 1995 in various surgical routine procedures. The future of these applications mainly rely on the technical progress in informatics, about image recognition to adapt the preplanning to the actual surgical situation, to correct brain shifts for instance, about image fusion, integrated knowledge such such as brain atlases, as well as virtual reality. The future developments, covering surgical procedure, research and teaching, will sure be far beyond our wildest expectations.

  10. From the Idea to Its Realization: The Evolution of Minimally Invasive Techniques in Neurosurgery

    PubMed Central

    Grunert, P.

    2013-01-01

    Minimally invasive techniques in neurosurgery evolved in two steps. Many minimally invasive concepts like neuronavigation, endoscopy, or frame based stereotaxy were developed by the pioneers of neurosurgery, but it took decades till further technical developments made the realization and broad clinical application of these early ideas safe and possible. This thesis will be demonstrated by giving examples of the evolution of four minimally invasive techiques: neuronavigation, transsphenoidal pituitary surgery, neuroendoscopy and stereotaxy. The reasons for their early failure and also the crucial steps for the rediscovery of these minimally invasive techniques will be analysed. In the 80th of the 20th century endoscopy became increasingly applied in different surgical fields. The abdominal surgeons coined as first for their endoscopic procedures the term minimally invasive surgery in contrast to open surgery. In neurrosurgery the term minimally invasive surgery stood not in opposiotion to open procedures but was understood as a general concept and philosophy using the modern technology such as neuronavigation, endoscopy and planing computer workstations with the aim to make the procedures less traumatic. PMID:24455231

  11. Sir Victor Horsley (1857-1916) and the birth of English neurosurgery.

    PubMed

    Hughes, J

    2007-02-01

    Modern surgery developed in the second half of the 19th century, at the end of which neurosurgery was established as a profitable region of operative intervention. In the British Isles, the first exponent was Sir William Macewen (1848-1924) in Glasgow. But neuroscience had advanced in London due to the excellence of the neurologists in the several hospitals there. Foremost among English neurosurgeons was Victor Horsley whose career had a worldwide influence on the speciality. Initially, operations were carried out for cranial trauma, the removal of displaced bone or blood clot, and the drainage of abscesses arising from infection of the middle ears and air sinuses. The diagnosis of brain and spinal tumours by neurologists encouraged removal by surgeons, of which Horsley was among the earliest. Horsley performed many operations on animals, experiments opposed by the anti-vivisectionists whose campaigns Horsley countered. Horsley had many other interests, some of which displeased the establishment, and in World War I his experience in neurosurgery was not used. He served as a general surgeon, visiting Egypt, India and Mesopotamia where, in Amara, he died from hyperpyrexia complicating bacillary dysentery. PMID:17356729

  12. Current state-of-the-art and future perspectives of robotic technology in neurosurgery.

    PubMed

    Mattei, Tobias A; Rodriguez, Abraham Hafiz; Sambhara, Deepak; Mendel, Ehud

    2014-07-01

    Neurosurgery is one of the most demanding surgical specialties in terms of precision requirements and surgical field limitations. Recent advancements in robotic technology have generated the possibility of incorporating advanced technological tools to the neurosurgical operating room. Although previous studies have addressed the specific details of new robotic systems, there is very little literature on the strengths and drawbacks of past attempts, currently available platforms and prototypes in development. In this review, the authors present a critical historical analysis of the development of robotic technology in neurosurgery as well as a comprehensive summary of the currently available systems that can be expected to be incorporated to the neurosurgical armamentarium in the near future. Finally, the authors present a critical analysis of the main technical challenges in robotic technology development at the present time (such as the design of improved systems for haptic feedback and the necessity of incorporating intraoperative imaging data) as well as the benefits which robotic technology is expected to bring to specific neurosurgical subspecialties in the near future.

  13. A neurologist in the origin of European and International neurosurgery: Clovis-Julien-Désiré Vincent (1879-1947).

    PubMed

    Androutsos, G; Karamanou, M; Lymberi, M; Zambelis, T; Stamboulis, E

    2011-01-01

    Vincent Clovis began his carrier as a neurologist and finally became neurosurgeon at an advanced age. He is considered the founder of French neurosurgery, and after Harvey Williams Cushing, Europe's first neurosurgeon. He was mainly interested in pituitary tumors, in cerebral abscesses and in cerebral oedema. PMID:22165053

  14. Functional and Pathogenic Differences of Th1 and Th17 Cells in Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Domingues, Helena S.; Mues, Marsilius; Lassmann, Hans; Wekerle, Hartmut; Krishnamoorthy, Gurumoorthy

    2010-01-01

    Background There is consensus that experimental autoimmune encephalomyelitis (EAE) can be mediated by myelin specific T cells of Th1 as well as of Th17 phenotype, but the contribution of either subset to the pathogenic process has remained controversial. In this report, we compare functional differences and pathogenic potential of “monoclonal” T cell lines that recognize myelin oligodendrocyte glycoprotein (MOG) with the same transgenic TCR but are distinguished by an IFN-γ producing Th1-like and IL-17 producing Th17-like cytokine signature. Methods and Findings CD4+ T cell lines were derived from the transgenic mouse strain 2D2, which expresses a TCR recognizing MOG peptide 35–55 in the context of I-Ab. Adoptive transfer of Th1 cells into lymphopenic (Rag2−/−) recipients, predominantly induced “classic” paralytic EAE, whereas Th17 cells mediated “atypical” ataxic EAE in approximately 50% of the recipient animals. Combination of Th1 and Th17 cells potentiated the encephalitogenicity inducing classical EAE exclusively. Th1 and Th17 mediated EAE lesions differed in their composition but not in their localization within the CNS. While Th1 lesions contained IFN-γ, but no IL-17 producing T cells, the T cells in Th17 lesions showed plasticity, substantially converting to IFN-γ producing Th1-like cells. Th1 and Th17 cells differed drastically by their lytic potential. Th1 but not Th17 cells lysed autoantigen presenting astrocytes and fibroblasts in vitro in a contact-dependent manner. In contrast, Th17 cells acquired cytotoxic potential only after antigenic stimulation and conversion to IFN-γ producing Th1 phenotype. Conclusions Our data demonstrate that both Th1 and Th17 lineages possess the ability to induce CNS autoimmunity but can function with complementary as well as differential pathogenic mechanisms. We propose that Th17-like cells producing IL-17 are required for the generation of atypical EAE whereas IFN-γ producing Th1 cells induce

  15. Inhaled Hydrogen Sulfide Improves Graft Function in an Experimental Model of Lung Transplantation

    PubMed Central

    George, Timothy J.; Arnaoutakis, George J.; Beaty, Claude A.; Jandu, Simran K.; Santhanam, Lakshmi; Berkowitz, Dan E.; Shah, Ashish S.

    2014-01-01

    Objectives: Ischemia-reperfusion(IRI) is a common complication of lung transplantation(LTx). Hydrogen sulfide(H2S) is a novel agent previously shown to slow metabolism and scavenge reactive oxygen species, potentially mitigating IRI. We hypothesized that pre-treatment with inhaled H2S would improve graft function in an ex vivo model of LTx. Methods: Rabbits(n=10) were ventilated for 2 hours prior to heart-lung bloc procurement. The treatment group(n=5) inhaled room air(21% O2) supplemented with 150 ppm H2S while the control group(n=5) inhaled room air alone. Both groups were gradually cooled to 34 C. All heart-lung blocs were then recovered and cold-stored in low potassium dextran solution for 18 hours. Following storage, the blocs were reperfused with donor rabbit blood in an ex vivo apparatus. Serial clinical parameters were assessed and serial tissue biochemistry was examined. Results: Prior to heart-lung bloc procurement, rabbits pre-treated with H2S exhibited similar oxygenation(p=0.1), ventilation(p=0.7), and heart rate(p=0.5); however, treated rabbits exhibited consistently higher mean arterial blood pressures(p=0.01). During reperfusion, lungs pre-treated with H2S had better oxygenation(p<0.01) and ventilation(p=0.02) as well as lower pulmonary artery pressures(p<0.01). Reactive oxygen species levels were lower in treated lungs during reperfusion(p=0.01). Additionally, prior to reperfusion, treated lungs demonstrated more preserved mitochondrial cytochrome c oxidase activity(p=0.01). Conclusions: To our knowledge, this study represents the first reported therapeutic use of inhaled H2S in an experimental model of LTx. After prolonged ischemia, lungs pre-treated with inhaled H2S exhibited improved graft function during reperfusion. Donor pre-treatment with inhaled H2S represents a potentially novel adjunct to conventional preservation techniques and merits further exploration. PMID:22771242

  16. CXCR4 Antagonist AMD3100 Modulates Claudin Expression and Intestinal Barrier Function in Experimental Colitis

    PubMed Central

    Xia, Xian-Ming; Wang, Fang-Yu; Zhou, Ju; Hu, Kai-Feng; Li, Su-Wen; Zou, Bing-Bing

    2011-01-01

    Ulcerative colitis is a gastrointestinal disorder characterized by local inflammation and impaired epithelial barrier. Previous studies demonstrated that CXC chemokine receptor 4 (CXCR4) antagonists could reduce colonic inflammation and mucosal damage in dextran sulfate sodium (DSS)-induced colitis. Whether CXCR4 antagonist has action on intestinal barrier and the possible mechanism, is largely undefined. In the present study, the experimental colitis was induced by administration of 5% DSS for 7 days, and CXCR4 antagonist AMD3100 was administered intraperitoneally once daily during the study period. For in vitro study, HT-29/B6 colonic cells were treated with cytokines or AMD3100 for 24 h until assay. DSS-induced colitis was characterized by morphologic changes in mice. In AMD3100-treated mice, epithelial destruction, inflammatory infiltration, and submucosal edema were markedly reduced, and the disease activity index was also significantly decreased. Increased intestinal permeability in DSS-induced colitis was also significantly reduced by AMD3100. The expressions of colonic claudin-1, claudin-3, claudin-5, claudin-7 and claudin-8 were markedly decreased after DSS administration, whereas colonic claudin-2 expression was significantly decreased. Treatment with AMD3100 prevented all these changes. However, AMD3100 had no influence on claudin-3, claudin-5, claudin-7 and claudin-8 expression in HT-29/B6 cells. Cytokines as TNF-α, IL-6, and IFN-γ increased apoptosis and monolayer permeability, inhibited the wound-healing and the claudin-3, claudin-7 and claudin-8 expression in HT-29/B6 cells. We suggest that AMD3100 acted on colonic claudin expression and intestinal barrier function, at least partly, in a cytokine-dependent pathway. PMID:22073304

  17. Experimental Evolution of a New Enzymatic Function. II. Evolution of Multiple Functions for EBG Enzyme in E. COLI

    PubMed Central

    Hall, Barry G.

    1978-01-01

    The evolution of ebgo enzyme of Escherichia coli, an enzyme which is unable to hydrolyze lactose, lactulose, lactobionate, or galactose-arabinoside effectively, has been directed in successive steps so that the evolved enzyme is able to hydrolyze these galactosides effectively. I show that in order for a strain of E. coli with a lacZ deletion to evolve the ability to use lactobionate as a carbon source, a series of mutations must occur in the ebg genes, and that these mutations must be selected in a particular order. The ordered series of mutations constitutes an obligatory evolutionary pathway for the acquisition of a new function for ebgo enzyme. A comparison of newly evolved strains with parental strains shows that when ebg enzyme acquires a new function, its old functions often suffer; but that in several cases old functions are either unaffected or are improved. I conclude that divergence of functions catalyzed by an enzyme need not require gene duplication. PMID:97169

  18. Modeling functional Magnetic Resonance Imaging (fMRI) experimental variables in the Ontology of Experimental Variables and Values (OoEVV).

    PubMed

    Burns, Gully A P C; Turner, Jessica A

    2013-11-15

    Neuroimaging data is raw material for cognitive neuroscience experiments, leading to scientific knowledge about human neurological and psychological disease, language, perception, attention and ultimately, cognition. The structure of the variables used in the experimental design defines the structure of the data gathered in the experiments; this in turn structures the interpretative assertions that may be presented as experimental conclusions. Representing these assertions and the experimental data which support them in a computable way means that they could be used in logical reasoning environments, i.e. for automated meta-analyses, or linking hypotheses and results across different levels of neuroscientific experiments. Therefore, a crucial first step in being able to represent neuroimaging results in a clear, computable way is to develop representations for the scientific variables involved in neuroimaging experiments. These representations should be expressive, computable, valid, extensible, and easy-to-use. They should also leverage existing semantic standards to interoperate easily with other systems. We present an ontology design pattern called the Ontology of Experimental Variables and Values (OoEVV). This is designed to provide a lightweight framework to capture mathematical properties of data, with appropriate 'hooks' to permit linkage to other ontology-driven projects (such as the Ontology of Biomedical Investigations, OBI). We instantiate the OoEVV system with a small number of functional Magnetic Resonance Imaging datasets, to demonstrate the system's ability to describe the variables of a neuroimaging experiment. OoEVV is designed to be compatible with the XCEDE neuroimaging data standard for data collection terminology, and with the Cognitive Paradigm Ontology (CogPO) for specific reasoning elements of neuroimaging experimental designs.

  19. Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats

    PubMed Central

    Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; de Barros Filho, Tarcísio Eloy Pessoa; Ferreira, Ricardo; dos Santos, Gustavo Bispo; da Rocha, Ivan Dias; Marcon, Raphael Martus

    2015-01-01

    OBJECTIVES: To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. METHODS: In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day. RESULTS: The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers. CONCLUSIONS: Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury. PMID:26598084

  20. Measuring the subjective value of risky and ambiguous options using experimental economics and functional MRI methods.

    PubMed

    Levy, Ifat; Rosenberg Belmaker, Lior; Manson, Kirk; Tymula, Agnieszka; Glimcher, Paul W

    2012-09-19

    Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition termed "risky". In other cases when probabilities cannot be estimated, this is a condition described as "ambiguous". While most people are averse to both risk and ambiguity(1,2), the degree of those aversions vary substantially across individuals, such that the subjective value of the same risky or ambiguous option can be very different for different individuals. We combine functional MRI (fMRI) with an experimental economics-based method(3 )to assess the neural representation of the subjective values of risky and ambiguous options(4). This technique can be now used to study these neural representations in different populations, such as different age groups and different patient populations. In our experiment, subjects make consequential choices between two alternatives while their neural activation is tracked using fMRI. On each trial subjects choose between lotteries that vary in their monetary amount and in either the probability of winning that amount or the ambiguity level associated with winning. Our parametric design allows us to use each individual's choice behavior to estimate their attitudes towards risk and ambiguity, and thus to estimate the subjective values that each option held for them. Another important feature of the design is that the outcome of the chosen lottery is not revealed during the experiment, so that no learning can take place, and thus the ambiguous options remain ambiguous and risk attitudes are stable. Instead, at the end of the scanning session one or few trials are randomly selected and played for real money. Since subjects do not know beforehand which trials will be selected, they must treat each and every trial as if it and it alone was the one trial on which they will be paid. This design ensures that we can estimate the true subjective value of each option to each subject. We

  1. Magnetic neurosurgery.

    PubMed

    Howard, M A; Grady, M S; Ritter, R C; Gillies, G T; Broaddus, W C; Dacey, R G

    1996-01-01

    Because of the complex shape of many brain structures, the ideal brain probe would be highly flexible and give the neurosurgeon the ability to independently and precisely control movement of the probe tip. A magnetic surgery system has been developed that implements this concept. Flexible brain probes with small permanent magnetic tips are placed on the brain surface through a small burr hole and then magnetically manipulated within the brain. Drive forces are produced by an array of six superconducting magnets suspended within a cryostatic helmet. They produce a maximum force of 3 times the threshold needed to move the probe through the parenchymal tissues at its normal speed of 1 mm/s. Computer-controlled magnetic impulses precisely direct the probe movement in any direction desired with movement accuracy of 0.47 mm in phantom gels. Probe position is monitored 3 times per second with orthogonally oriented microchannel plate X-ray systems, X-ray dose from a 3-hour simulated procedure is comparable to that of a chest X-ray. In vivo and in vitro feasibility studies have been carried out in dog and pig brains. Preclinical trials are planned for clinical applications including implantation of flexible brachytherapy threads.

  2. Multiple sclerosis in Mexico: hospital cases at the National Institute of Neurology and Neurosurgery, Mexico City.

    PubMed

    Corona, T; Rodrigues, J L; Otero, E; Stopp, L

    1996-05-01

    The frequency and clinical features of multiple sclerosis (MS) at the National Institute of Neurology and Neurosurgery in Mexico City for the period spanning 1984-1993 is presented. Hospital records of patients with clinically diagnosed MS were selected, the frequency and cumulative frequency of this diagnosis were determined and demographic information and clinical features were recorded. It was found that 70% of the patients were women, 25% were professionals, and 95% were of mixed race. The clinical features of our patients and their neuroimages were consistent with those of MS patients in other populations. Importantly, we found that the frequency of MS has almost doubled over the last 10 years. The reason for this phenomenon is discussed as resulting from better health screening, the availability of nuclear magnetic resonance imaging, and the cultural, demographic and dietary changes that have occurred due to the rapid urbanization of our country.

  3. System and methods for wide-field quantitative fluorescence imaging during neurosurgery.

    PubMed

    Valdes, Pablo A; Jacobs, Valerie L; Wilson, Brian C; Leblond, Frederic; Roberts, David W; Paulsen, Keith D

    2013-08-01

    We report an accurate, precise and sensitive method and system for quantitative fluorescence image-guided neurosurgery. With a low-noise, high-dynamic-range CMOS array, we perform rapid (integration times as low as 50 ms per wavelength) hyperspectral fluorescence and diffuse reflectance detection and apply a correction algorithm to compensate for the distorting effects of tissue absorption and scattering. Using this approach, we generated quantitative wide-field images of fluorescence in tissue-simulating phantoms for the fluorophore PpIX, having concentrations and optical absorption and scattering variations over clinically relevant ranges. The imaging system was tested in a rodent model of glioma, detecting quantitative levels down to 20 ng/ml. The resulting performance is a significant advance on existing wide-field quantitative imaging techniques, and provides performance comparable to a point-spectroscopy probe that has previously demonstrated significant potential for improved detection of malignant brain tumors during surgical resection. PMID:23903142

  4. An Intelligent Robotic Hospital Bed for Safe Transportation of Critical Neurosurgery Patients Along Crowded Hospital Corridors.

    PubMed

    Wang, Chao; Savkin, Andrey V; Clout, Ray; Nguyen, Hung T

    2015-09-01

    We present a novel design of an intelligent robotic hospital bed, named Flexbed, with autonomous navigation ability. The robotic bed is developed for fast and safe transportation of critical neurosurgery patients without changing beds. Flexbed is more efficient and safe during the transportation process comparing to the conventional hospital beds. Flexbed is able to avoid en-route obstacles with an efficient easy-to-implement collision avoidance strategy when an obstacle is nearby and to move towards its destination at maximum speed when there is no threat of collision. We present extensive simulation results of navigation of Flexbed in the crowded hospital corridor environments with moving obstacles. Moreover, results of experiments with Flexbed in the real world scenarios are also presented and discussed.

  5. Paediatric day-case neurosurgery in a resource challenged setting: Pattern and practice

    PubMed Central

    Owojuyigbe, Afolabi Muyiwa; Komolafe, Edward O.; Adenekan, Anthony T.; Dada, Muyiwa A.; Onyia, Chiazor U.; Ogunbameru, Ibironke O.; Owagbemi, Oluwafemi F.; Talabi, Ademola O.; Faponle, Fola A.

    2016-01-01

    Background: It has been generally observed that children achieve better convalescence in the home environment especially if discharged same day after surgery. This is probably due to the fact that children generally tend to feel more at ease in the home environment than in the hospital setting. Only few tertiary health institutions provide routine day-case surgery for paediatric neurosurgical patients in our sub-region. Objective: To review the pattern and practice of paediatric neurosurgical day-cases at our hospital. Patients and Methods: A prospective study of all paediatric day-case neurosurgeries carried out between June 2011 and June 2014. Results: A total of 53 patients (34 males and 19 females) with age ranging from 2 days to 14 years were seen. Majority of the patients (77.4%) presented with congenital lesions, and the most common procedure carried out was spina bifida repair (32%) followed by ventriculoperitoneal shunt insertion (26.4%) for hydrocephalus. Sixty-eight percentage belonged to the American Society of Anesthesiologists physical status class 2, whereas the rest (32%) belonged to class 1. General anaesthesia was employed in 83% of cases. Parenteral paracetamol was used for intra-operative analgesia for most of the patients. Two patients had post-operative nausea and vomiting and were successfully managed. There was no case of emergency re-operation, unplanned admission, cancellation or mortality. Conclusion: Paediatric day-case neurosurgery is feasible in our environment. With careful patient selection and adequate pre-operative preparation, good outcome can be achieved. PMID:27251657

  6. A Patient Registry to Improve Patient Safety: Recording General Neurosurgery Complications

    PubMed Central

    Sarnthein, Johannes; Stieglitz, Lennart; Clavien, Pierre-Alain; Regli, Luca

    2016-01-01

    Background To improve the transparency of the local health care system, treatment cost was recently referenced to disease related groups. Treatment quality must be legally documented in a patient registry, in particular for the highly specialized treatments provided by neurosurgery departments. Methods In 2013 we have installed a patient registry focused on cranial neurosurgery. Surgeries are characterized by indication, treatment, location and other specific neurosurgical parameters. Preoperative state and postoperative outcome are recorded prospectively using neurological and sociological scales. Complications are graded by their severity in a therapy-oriented complication score system (Clavien-Dindo-Grading system, CDG). Results are presented at the monthly clinical staff meeting. Results Data acquisition compatible with the clinic workflow permitted to include all eligible patients into the registry. Until December 2015, we have registered 2880 patients that were treated in 3959 surgeries and 8528 consultations. Since the registry is fully operational (August 2014), we have registered 325 complications on 1341 patient discharge forms (24%). In 64% of these complications, no or only pharmacological treatment was required. At discharge, there was a clear correlation of the severity of the complication and the Karnofsky Performance Status (KPS, ρ = -0.3, slope -6 KPS percentage points per increment of CDG) and the length of stay (ρ = 0.4, slope 1.5 days per increment of CDG). Conclusions While the therapy-oriented complication scores correlate reasonably well with outcome and length of stay, they do not account for new deficits that cannot be treated. Outcome grading and complication severity grading thus serve a complimentary purpose. Overall, the registry serves to streamline and to complete information flow in the clinic, to identify complication rates and trends early for the internal quality monitoring and communication with patients. Conversely, the

  7. Integrating risk management data in quality improvement initiatives within an academic neurosurgery department.

    PubMed

    McLaughlin, Nancy; Garrett, Matthew C; Emami, Leila; Foss, Sarah K; Klohn, Johanna L; Martin, Neil A

    2016-01-01

    OBJECT While malpractice litigation has had many negative impacts on health care delivery systems, information extracted from lawsuits could potentially guide toward venues to improve care. The authors present a comprehensive review of lawsuits within a tertiary academic neurosurgical department and report institutional and departmental strategies to mitigate liability by integrating risk management data with quality improvement initiatives. METHODS The Comprehensive Risk Intelligence Tool database was interrogated to extract claims/suits abstracts concerning neurosurgical cases that were closed from January 2008 to December 2012. Variables included demographics of the claimant, type of procedure performed (if any), claim description, insured information, case outcome, clinical summary, contributing factors and subfactors, amount incurred for indemnity and expenses, and independent expert opinion in regard to whether the standard of care was met. RESULTS During the study period, the Department of Neurosurgery received the most lawsuits of all surgical specialties (30 of 172), leading to a total incurred payment of $4,949,867. Of these lawsuits, 21 involved spinal pathologies and 9 cranial pathologies. The largest group of suits was from patients with challenging medical conditions who underwent uneventful surgeries and postoperative courses but filed lawsuits when they did not see the benefits for which they were hoping; 85% of these claims were withdrawn by the plaintiffs. The most commonly cited contributing factors included clinical judgment (20 of 30), technical skill (19 of 30), and communication (6 of 30). CONCLUSIONS While all medical and surgical subspecialties must deal with the issue of malpractice and liability, neurosurgery is most affected both in terms of the number of suits filed as well as monetary amounts awarded. To use the suits as learning tools for the faculty and residents and minimize the associated costs, quality initiatives addressing the

  8. Application of underwater shock wave and laser-induced liquid jet to neurosurgery

    NASA Astrophysics Data System (ADS)

    Tominaga, T.; Nakagawa, A.; Hirano, T.; Sato, J.; Kato, K.; Hosseini, S. H. R.; Takayama, K.

    2006-03-01

    Paper deals with applications of underwater shock waves to medicine. A historical development of underwater shock wave generation by using pulsed Ho:YAG laser beam irradiation in water is briefly described and an overview is given regarding potential applications of shock waves to neuro-surgery. The laser beam irradiation in a liquid-filled catheter produces water vapor bubble and shock waves intermittently produces micro-liquid jets in a controlled fashion from the exit of the catheter. Correlations between shock dynamics and bubble dynamics are emphasized. To optimize the jet motion, results of basic parametric studies are briefly presented. The liquid jet discharged from the catheter exit has an impulse high enough to clearly exhibit effectiveness for various medical purposes. In liquid jets we observed reasonably strong shock waves and hence invented a compact shock generator aiming to apply to microsurgery. We applied it to a rat's bone window and developed an effective method of brain protection against shock loading. The insertion of Gore-Tex® sheet is found to attenuate shock waves drastically even for very short stand off distance and its physical mechanism is clarified. The laser-induced liquid jet (LILJ) is successfully applied to soft tissue dissection. Animal experiments were performed and results of histological observations are presented in details. Results of animal experiments revealed that LILJ can sharply dissect soft tissue with a minimum amount of liquid consumption, while blood vessels larger than 0.2 mm in diameter are preserved. Shock waves and LILJ have a potential to be indispensable tools in neuro-surgery.

  9. An American medical student's experience in global neurosurgery: both in their infancy.

    PubMed

    Magarik, Jordan; Kavolus, Joseph; Louis, Robert

    2012-01-01

    There are only three fully trained neurosurgeons to care for Tanzania's population of more than 41 million people. Madaktari was founded in 2006 to serve as a physician training partnership to establish more self-sufficient health care through education and training. Medical students play a valuable role in Madaktari as they are primarily responsible for collecting postneurosurgical outcome data on operations performed by Tanzanian physicians trained by our organization. In addition, medical students represent the future of global medicine. Thus, it is important to determine the extent that Madaktari has affected student interest in global health. Our purpose in this article is to explore one student's experience working in global neurosurgery while working with Madaktari. In addition we attempted to determine the effect Madaktari may play on the future medical careers of eight medical student volunteers. To determine that effect we conducted a six-question online survey of medical student volunteers. We received responses from four of our eight medical student volunteers, all of whom stated they had a good or excellent experience volunteering with Madaktari and that their experience further increased their desire to incorporate global health into their careers. After working with Madaktari nearly half of the medical student volunteers have pursued or will be pursuing year-long funded global health research during their medical school careers. Madaktari is not only pioneering a path toward increased and more independent neurosurgical capabilities in Tanzania, but it is also helping foster increased interest and participation among U.S. medical students in global neurosurgery. PMID:22079820

  10. Slow angled-descent forepaw grasping (SLAG): an innate behavioral task for identification of individual experimental mice possessing functional vision

    PubMed Central

    2013-01-01

    Background There is significant interest in the generation of improved assays to clearly identify experimental mice possessing functional vision, a property that could qualify mice for inclusion in behavioral and neuroscience studies. Widely employed current methods rely on mouse responses to visual cues in assays of reflexes, depth perception, or cognitive memory. However, commonly assessed mouse reflexes can sometimes be ambiguous in their expression, while depth perception assays are sometimes confounded by variation in anxiety responses and exploratory conduct. Furthermore, in situations where experimental groups vary in their cognitive memory capacity, memory assays may not be ideal for assessing differences in vision. Results We have optimized a non-invasive behavioral assay that relies on an untrained, innate response to identify individual experimental mice possessing functional vision: slow angled-descent forepaw grasping (SLAG). First, we verified that SLAG performance depends on vision and not olfaction. Next, all members of an age-ranged cohort of 158 C57BL/6 mice (57 wild-type, 101 knockout, age range 44–241 days) were assessed for functional vision using the SLAG test without training or conditioning. Subjecting the population to a second innate behavioral test, Dark Chamber preference, corroborated that the functional vision assessment of SLAG was valid. Conclusions We propose that the SLAG assay is immediately useful to quickly and clearly identify experimental mice possessing functional vision. SLAG is based on a behavioral readout with a significant innate component with no requirement for training. This will facilitate the selection of mice of known sighted status in vision-dependent experiments that focus on other types of behavior, neuroscience, and/or cognitive memory. PMID:23971729

  11. Beyond conservatism and the boundaries of a medical discipline: a short history of the department of neurosurgery at kyoto university graduate school of medicine.

    PubMed

    Hashimoto, Nobuo; Handa, Hajime; Kikuchi, Haruhiko

    2002-10-01

    CONSTANT CHANGE AND the occasional fusion of two different entities can result in the creation of masterpieces, not only in art but also in neurosurgery. Chisato Araki is one of the pioneers of neurosurgery in Japan; his 2-year sojourn in the United States and Europe provided him with an extraordinary amount of experience. He traveled throughout the world at a time when it took 30 days to journey from Yokohama to New York, and he visited with most of the leading contemporary neurosurgeons and observed their operations, never abandoning his highly honed critical insights. Driven by passion and a deep sense of duty to pass on his knowledge and perspective, he became a beacon of hope and encouragement for young physicians working in a country devastated by war. His successor, Hajime Handa, established neurosurgery as one of the branches of neuroscience and fostered the collaborations and exchanges among different disciplines that have become a tradition and hallmark of our Department of Neurosurgery. Through anecdotes and glimpses of the evolution of neurosurgery at our institution, we offer insights into the unique nature of Japanese neurosurgery that may illuminate the path toward the resolution of some of the recent and enduring problems encountered in our specialty.

  12. Experimental and Theoretical Analysis of Nanotransport in Oligophenylene Dithiol Junctions as a Function of Molecular Length and Contact Work Function.

    PubMed

    Xie, Zuoti; Bâldea, Ioan; Smith, Christopher E; Wu, Yanfei; Frisbie, C Daniel

    2015-08-25

    We report the results of an extensive investigation of metal-molecule-metal tunnel junctions based on oligophenylene dithiols (OPDs) bound to several types of electrodes (M1-S-(C6H4)n-S-M2, with 1 ≤ n ≤ 4 and M1,2 = Ag, Au, Pt) to examine the impact of molecular length (n) and metal work function (Φ) on junction properties. Our investigation includes (1) measurements by scanning Kelvin probe microscopy of electrode work function changes (ΔΦ = ΦSAM - Φ) caused by chemisorption of OPD self-assembled monolayers (SAMs), (2) measurements of junction current-voltage (I-V) characteristics by conducting probe atomic force microscopy in the linear and nonlinear bias ranges, and (3) direct quantitative analysis of the full I-V curves. Further, we employ transition voltage spectroscopy (TVS) to estimate the energetic alignment εh = EF - EHOMO of the dominant molecular orbital (HOMO) relative to the Fermi energy EF of the junction. Where photoelectron spectroscopy data are available, the εh values agree very well with those determined by TVS. Using a single-level model, which we justify via ab initio quantum chemical calculations at post-density functional theory level and additional UV-visible absorption measurements, we are able to quantitatively reproduce the I-V measurements in the whole bias range investigated (∼1.0-1.5 V) and to understand the behavior of εh and Γ (contact coupling strength) extracted from experiment. We find that Fermi level pinning induced by the strong dipole of the metal-S bond causes a significant shift of the HOMO energy of an adsorbed molecule, resulting in εh exhibiting a weak dependence with the work function Φ. Both of these parameters play a key role in determining the tunneling attenuation factor (β) and junction resistance (R). Correlation among Φ, ΔΦ, R, transition voltage (Vt), and εh and accurate simulation provide a remarkably complete picture of tunneling transport in these prototypical molecular junctions.

  13. Verbal Conditioning of Male and Female Schizophrenics as a Function of Experimenter Proximity

    ERIC Educational Resources Information Center

    Rierdan, Jill; Brooks, Robert

    1978-01-01

    Assess the effects of patient-experimenter proximity on schizophrenics' learning when the social class of the subjects, both schizophrenics and nonschizophrenics, and the verbal and nonverbal components of social reinforcement are controlled. Also tests males and females to determine whether sex of subjects moderates the responses of…

  14. [Uniform model and experimental method of anaerobic inhibition dynamics using table function].

    PubMed

    Yan, Zhong; Wang, Kai-Jun

    2008-05-01

    To figure out the problem, such as disunity of existent form in the model of traditional inhibition dynamic, and difficulty to obtain the parameters, we adopt the way of table function to formulate inhibition kinetics. Through indraught the way of table function to improve on the way of experiment in dynamic mensuration, DYNAMO software was used to process the data and simulate the inhibition phenomena of 2,4 dinitrophenol. The result shows that the table function is possible to simulate the inhibition phenomena. Compared with the traditional inhibition dynamic, the simulation curve of table function is much more close to the data of experiment, the modality is simple and unify, and simultaneously it solves the problem of parameter obtaining. When the complex inhibition phenomena is simulated, the table function shows obvious advantage, and may predigest the structure of model at a certain extent.

  15. Experimental models to investigate the function of dendritic cell subsets: challenges and implications.

    PubMed

    Hancock, D G; Guy, T V; Shklovskaya, E; Fazekas de St Groth, B

    2013-02-01

    The dendritic cell (DC) lineage is remarkably heterogeneous. It has been postulated that specialized DC subsets have evolved in order to select and support the multitude of possible T cell differentiation pathways. However, defining the function of individual DC subsets has proven remarkably difficult, and DC subset control of key T cell fates such as tolerance, T helper cell commitment and regulatory T cell induction is still not well understood. While the difficulty in assigning unique functions to particular DC subsets may be due to sharing of functions, it may also reflect a lack of appropriate physiological in-vivo models for studying DC function. In this paper we review the limitations associated with many of the current DC models and highlight some of the underlying difficulties involved in studying the function of murine DC subsets.

  16. CT10 NLO and NNLO Parton Distribution Functions from the Coordinated Theoretical-Experimental Project on QCD

    DOE Data Explorer

    Huston, Joey [Co-Spokesperson; Ownes, Joseph [Co-Spokesperson

    The Coordinated Theoretical-Experimental Project on QCD is a multi-institutional collaboration devoted to a broad program of research projects and cooperative enterprises in high-energy physics centered on Quantum Chromodynamics (QCD) and its implications in all areas of the Standard Model and beyond. The Collaboration consists of theorists and experimentalists at 18 universities and 5 national laboratories. More than 65 sets of Parton Distribution Functions are available for public access. Links to many online software tools, information about Parton Distribution Functions, papers, and other resources are also available.

  17. The Synthesis of Structural Responses Using Experimentally Measured Frequency Response Functions and Field Test Data

    SciTech Connect

    CAP,JEROME S.; NELSON,CURTIS F.

    2000-11-17

    This paper presents an analysis technique used to generate the structural response at locations not measured during the ejection of a captive-carried store. The ejection shock event is complicated by the fact that forces may be imparted to the store at eight distinct locations. The technique derives forcing functions by combining the initial field test data for a limited number of measurement locations with Frequency Response Functions (FRFs) measured using a traditional modal-type impact (tap) test at the same locations. The derived forcing functions were then used with tap test FRFs measured at additional locations of interest to produce the desired response data.

  18. An experimental method to obtain the elastic strain energy function from torsion-tension tests

    NASA Technical Reports Server (NTRS)

    Peng, S. T. J.; Landel, R. F.

    1976-01-01

    It is shown that by employing a torsion-tension test, it is possible to have a complete mapping near the origin of the two principal strain invariants associated with the rate of change of the strain energy function. However, the mathematical representation of the twist moment and normal forces vs strain and the strain energy function are complex. This problem is solved by using a set of solid cylindrical bars with different diameters such that the difference in diameter of two successive bars is small. The stress-strain equations can be grossly oversimplified by considering differences in twist moment and normal force as a function of difference in radius.

  19. Role of Inhibitors of Apoptosis Proteins in Testicular Function and Male Fertility: Effects of Polydeoxyribonucleotide Administration in Experimental Varicocele.

    PubMed

    Minutoli, Letteria; Arena, Salvatore; Antonuccio, Pietro; Romeo, Carmelo; Bitto, Alessandra; Magno, Carlo; Rinaldi, Mariagrazia; Micali, Antonio; Irrera, Natasha; Pizzino, Gabriele; Galfo, Federica; Squadrito, Francesco; Altavilla, Domenica; Marini, Herbert

    2015-01-01

    Neuronal apoptosis inhibitory protein (NAIP) and survivin might play an important role in testicular function. We investigated the effect of PDRN, an agonist of adenosine A2A receptor, on testicular NAIP and survivin expression in an experimental model of varicocele. After the creation of experimental varicocele (28 days), adolescent male Sprague-Dawley rats were randomized to one of the following treatments lasting 21 days: vehicle, PDRN (8 mg/kg i.p., daily), PDRN + 3,7-dimethyl-propargylxanthine (DMPX, a specific adenosine A2A-receptor antagonist, 0.1 mg/kg i.p., daily), varicocelectomy, and varicocelectomy + PDRN (8 mg/kg i.p., daily). Sham-operated animals were used as controls. Animals were then euthanized and testis expression of NAIP and survivin was evaluated through qRT-PCR, western blot, and immunohistochemical analysis. Spermatogenetic activity was also assessed. NAIP and survivin expressions were significantly reduced following varicocele induction when compared to sham animals whereas PDRN-treated rats showed an increase in NAIP and survivin levels. Immunohistochemistry revealed an enhanced expression of NAIP and survivin with a characteristic pattern of cellular localization following PDRN treatment. Moreover, administration of PDRN significantly restored spermatogenic function in varicocele rats. PDRN may represent a rational therapeutic option for accelerating recovery from depressed testicular function through a strategic modulation of apoptosis in experimental varicocele. PMID:26347229

  20. Role of Inhibitors of Apoptosis Proteins in Testicular Function and Male Fertility: Effects of Polydeoxyribonucleotide Administration in Experimental Varicocele.

    PubMed

    Minutoli, Letteria; Arena, Salvatore; Antonuccio, Pietro; Romeo, Carmelo; Bitto, Alessandra; Magno, Carlo; Rinaldi, Mariagrazia; Micali, Antonio; Irrera, Natasha; Pizzino, Gabriele; Galfo, Federica; Squadrito, Francesco; Altavilla, Domenica; Marini, Herbert

    2015-01-01

    Neuronal apoptosis inhibitory protein (NAIP) and survivin might play an important role in testicular function. We investigated the effect of PDRN, an agonist of adenosine A2A receptor, on testicular NAIP and survivin expression in an experimental model of varicocele. After the creation of experimental varicocele (28 days), adolescent male Sprague-Dawley rats were randomized to one of the following treatments lasting 21 days: vehicle, PDRN (8 mg/kg i.p., daily), PDRN + 3,7-dimethyl-propargylxanthine (DMPX, a specific adenosine A2A-receptor antagonist, 0.1 mg/kg i.p., daily), varicocelectomy, and varicocelectomy + PDRN (8 mg/kg i.p., daily). Sham-operated animals were used as controls. Animals were then euthanized and testis expression of NAIP and survivin was evaluated through qRT-PCR, western blot, and immunohistochemical analysis. Spermatogenetic activity was also assessed. NAIP and survivin expressions were significantly reduced following varicocele induction when compared to sham animals whereas PDRN-treated rats showed an increase in NAIP and survivin levels. Immunohistochemistry revealed an enhanced expression of NAIP and survivin with a characteristic pattern of cellular localization following PDRN treatment. Moreover, administration of PDRN significantly restored spermatogenic function in varicocele rats. PDRN may represent a rational therapeutic option for accelerating recovery from depressed testicular function through a strategic modulation of apoptosis in experimental varicocele.

  1. Evidence-based neurosurgery. Basic concepts for the appraisal and application of scientific information to patient care (Part II).

    PubMed

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

    2016-07-01

    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

  2. The Krigifier: A Procedure for Generating Pseudorandom Nonlinear Objective Functions for Computational Experimentation

    NASA Technical Reports Server (NTRS)

    Trosset, Michael W.

    1999-01-01

    Comprehensive computational experiments to assess the performance of algorithms for numerical optimization require (among other things) a practical procedure for generating pseudorandom nonlinear objective functions. We propose a procedure that is based on the convenient fiction that objective functions are realizations of stochastic processes. This report details the calculations necessary to implement our procedure for the case of certain stationary Gaussian processes and presents a specific implementation in the statistical programming language S-PLUS.

  3. Functional Analysis and Discovery of Microbial Genes Transforming Metallic and Organic Pollutants: Database and Experimental Tools

    SciTech Connect

    Lawrence P. Wackett; Lynda B.M. Ellis

    2004-12-09

    Microbial functional genomics is faced with a burgeoning list of genes which are denoted as unknown or hypothetical for lack of any knowledge about their function. The majority of microbial genes encode enzymes. Enzymes are the catalysts of metabolism; catabolism, anabolism, stress responses, and many other cell functions. A major problem facing microbial functional genomics is proposed here to derive from the breadth of microbial metabolism, much of which remains undiscovered. The breadth of microbial metabolism has been surveyed by the PIs and represented according to reaction types on the University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD): http://umbbd.ahc.umn.edu/search/FuncGrps.html The database depicts metabolism of 49 chemical functional groups, representing most of current knowledge. Twice that number of chemical groups are proposed here to be metabolized by microbes. Thus, at least 50% of the unique biochemical reactions catalyzed by microbes remain undiscovered. This further suggests that many unknown and hypothetical genes encode functions yet undiscovered. This gap will be partly filled by the current proposal. The UM-BBD will be greatly expanded as a resource for microbial functional genomics. Computational methods will be developed to predict microbial metabolism which is not yet discovered. Moreover, a concentrated effort to discover new microbial metabolism will be conducted. The research will focus on metabolism of direct interest to DOE, dealing with the transformation of metals, metalloids, organometallics and toxic organics. This is precisely the type of metabolism which has been characterized most poorly to date. Moreover, these studies will directly impact functional genomic analysis of DOE-relevant genomes.

  4. Automated genomic context analysis and experimental validation platform for discovery of prokaryote transcriptional regulator functions

    SciTech Connect

    Martí-Arbona, Ricardo; Mu, Fangping; Nowak-Lovato, Kristy L.; Wren, Melinda S.; Unkefer, Clifford J.; Unkefer, Pat J.

    2014-12-18

    The clustering of genes in a pathway and the co-location of functionally related genes is widely recognized in prokaryotes. We used these characteristics to predict the metabolic involvement for a Transcriptional Regulator (TR) of unknown function, identified and confirmed its biological activity. A software tool that identifies the genes encoded within a defined genomic neighborhood for the subject TR and its homologs was developed. The output lists of genes in the genetic neighborhoods, their annotated functions, the reactants/products, and identifies the metabolic pathway in which the encoded-proteins function. When a set of TRs of known function was analyzed, we observed that their homologs frequently had conserved genomic neighborhoods that co-located the metabolically related genes regulated by the subject TR. We postulate that TR effectors are metabolites in the identified pathways; indeed the known effectors were present. We analyzed Bxe_B3018 from Burkholderia xenovorans, a TR of unknown function and predicted that this TR was related to the glycine, threonine and serine degradation. We tested the binding of metabolites in these pathways and for those that bound, their ability to modulate TR binding to its specific DNA operator sequence. Using rtPCR, we confirmed that methylglyoxal was an effector of Bxe_3018.

  5. Automated genomic context analysis and experimental validation platform for discovery of prokaryote transcriptional regulator functions

    DOE PAGESBeta

    Martí-Arbona, Ricardo; Mu, Fangping; Nowak-Lovato, Kristy L.; Wren, Melinda S.; Unkefer, Clifford J.; Unkefer, Pat J.

    2014-12-18

    The clustering of genes in a pathway and the co-location of functionally related genes is widely recognized in prokaryotes. We used these characteristics to predict the metabolic involvement for a Transcriptional Regulator (TR) of unknown function, identified and confirmed its biological activity. A software tool that identifies the genes encoded within a defined genomic neighborhood for the subject TR and its homologs was developed. The output lists of genes in the genetic neighborhoods, their annotated functions, the reactants/products, and identifies the metabolic pathway in which the encoded-proteins function. When a set of TRs of known function was analyzed, we observedmore » that their homologs frequently had conserved genomic neighborhoods that co-located the metabolically related genes regulated by the subject TR. We postulate that TR effectors are metabolites in the identified pathways; indeed the known effectors were present. We analyzed Bxe_B3018 from Burkholderia xenovorans, a TR of unknown function and predicted that this TR was related to the glycine, threonine and serine degradation. We tested the binding of metabolites in these pathways and for those that bound, their ability to modulate TR binding to its specific DNA operator sequence. Using rtPCR, we confirmed that methylglyoxal was an effector of Bxe_3018.« less

  6. Cardiac-Specific YAP Activation Improves Cardiac Function and Survival in an Experimental Murine MI Model

    PubMed Central

    Lin, Zhiqiang; von Gise, Alexander; Zhou, Pingzhu; Gu, Fei; Ma, Qing; Jiang, Jiangming; Yau, Allan L.; Buck, Jessica N.; Gouin, Katryna A.; van Gorp, Pim R. R.; Zhou, Bin; Chen, Jinghai; Seidman, Jonathan G.; Wang, Da-zhi; Pu, William T.

    2014-01-01

    Rationale Yes-Associated Protein (YAP), the terminal effector of the Hippo signaling pathway, is crucial for regulating embryonic cardiomyocyte (CM) proliferation. Objective We hypothesized that YAP activation after myocardial infarction would preserve cardiac function and improve survival. Methods and Results We used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted CM proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the adult murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing CM apoptosis. Rather, AAV9:hYAP stimulated adult CM proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated expression of cell cycle genes and promoted a less mature cardiac gene expression signature. Conclusions Cardiac specific YAP activation after MI mitigated myocardial injury, improved cardiac function, and enhanced survival. These findings suggest that therapeutic activation of YAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI. PMID:24833660

  7. Experimental and theoretical investigations of functionalized boron nitride as electrode materials for Li-ion batteries

    SciTech Connect

    Zhang, Fan; Nemeth, Karoly; Bareño, Javier; Dogan, Fulya; Bloom, Ira D.; Shaw, Leon L.

    2016-01-01

    The feasibility of synthesizing functionalized h-BN (FBN) via the reaction between molten LiOH and solid h-BN is studied for the first time and its first ever application as an electrode material in Li-ion batteries is evaluated. Density functional theory (DFT) calculations are performed to provide mechanistic understanding of the possible electrochemical reactions derived from the FBN. Various materials characterizations reveal that the melt-solid reaction can lead to exfoliation and functionalization of h-BN simultaneously, while electrochemical analysis proves that the FBN can reversibly store charges through surface redox reactions with good cycle stability and coulombic efficiency. DFT calculations have provided physical insights into the observed electrochemical properties derived from the FBN.

  8. [Experimental studies in animals on the bladder function following sacral blockade with alkohol (author's transl)].

    PubMed

    Fischer, D; Gerbershagen, H U; Wenzel, K G; Stockamp, K; Baar, H A

    1975-03-01

    Caudal anesthesia was achieved with Xylocain-R in 13 dogs and with ethanol (99,2 percent) in 8 dogs. Urinary bladder function was studied before and after block. The results obtained are in agreement with the functional changes after rhizotomy of S1--S3: bladder capacity increases after cuadal block and pressures measured at equal volumes decrease. Urinary overflow was observed; 80 percent of the filling volume, however, remains within the bladder. An autonomous bladder contraction induced by smypathetic nerve activity could not be proven within our observation period of 7 days.

  9. Electronic and optical response of Ru(II) complexes functionalized by methyl, carboxylate groups: joint theoretical and experimental study

    SciTech Connect

    Tretiak, Sergei

    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 complex to the surface of a semiconductor, a linking bridge - a carboxyl group - is added to one or two of the 2,2{prime}-bipyridine ligands. Such changes in the ligand structure, indeed, affect electronic and optical properties and consequently, the charge transfer reactivity of Ru-systems. In this study, we apply both theoretical and experimental approaches to 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(II) bipyridine complex. First principle calculations based on density functional theory (DFT) and linear response time dependent density functional theory (TDDFT) are used to simulate the ground and excited-state structures of functionalized Ru-complexes in the gas phase, as well as in acetonitrile solution. In addition, an inelaborate Frenkel exciton model is used to explain the optical activity and splitting patterns of the low-energy excited states. All theoretical results nicely complement experimental absorption spectra of Ru-complexes and contribute to their interpretation. 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 a high probability of deprotonation of the carbboxyl group in the Ru-complexes resulted in a slight blue shift and decrease of intensities of the low energy absorption peaks. Comparison of experimental and theoretical linear response spectra of deprotanated complexes demonstrate strong agreement when acetonitrile solvent is used in simulations. A polar solvent is found to play an important role in calculations of optical spectra: it

  10. [Early and Delayed Effects of Radio Frequency Electromagnetic Fields on the Reproductive Function and Functional Status of the Offspring of Experimental Animals].

    PubMed

    Shibkova, D Z; Shilkova, T V; Ovchinnikova, A V

    2015-01-01

    The aim of our experimental research was to study the impact of radio frequency electromagnetic fields (RF EMF) on the reproductive function of male and female mice of CBA in 2 models of exposure, as well as on the morphofunctional state of progeny of irradiated animals. It was found that RF EMF under conditions of repeated short-term exposures (within 5 days for 10 minutes at PES 1.2 mW/cm2) affects the course of pregnancy in female mice, the number of litters, fertility and preservation of offspring, morphometric characteristics of the offspring of experimental animals at different models of irradiation (exposure of animals to RF EMF prior to mating and during pregnancy). PMID:26863782

  11. [Early and Delayed Effects of Radio Frequency Electromagnetic Fields on the Reproductive Function and Functional Status of the Offspring of Experimental Animals].

    PubMed

    Shibkova, D Z; Shilkova, T V; Ovchinnikova, A V

    2015-01-01

    The aim of our experimental research was to study the impact of radio frequency electromagnetic fields (RF EMF) on the reproductive function of male and female mice of CBA in 2 models of exposure, as well as on the morphofunctional state of progeny of irradiated animals. It was found that RF EMF under conditions of repeated short-term exposures (within 5 days for 10 minutes at PES 1.2 mW/cm2) affects the course of pregnancy in female mice, the number of litters, fertility and preservation of offspring, morphometric characteristics of the offspring of experimental animals at different models of irradiation (exposure of animals to RF EMF prior to mating and during pregnancy).

  12. Experimental and theoretical spectroscopic studies of anticancer drug rosmarinic acid using HF and density functional theory

    NASA Astrophysics Data System (ADS)

    Mariappan, G.; Sundaraganesan, N.; Manoharan, S.

    2012-11-01

    In this work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and NBO analysis of anticancer drug of rosmarinic acid. The optimized molecular structure, atomic charges, vibrational frequencies, natural bond orbital analysis and ultraviolet-visible spectral interpretation of rosmarinic acid have been studied by performing HF and DFT/B3LYP/6-31G(d,p) level of theory. The FT-IR (solid and solution phase), FT-Raman (solid phase) spectra were recorded in the region 4000-400 and 3500-50 cm-1, respectively. The UV-Visible absorption spectra of the compound that dissolved in ethanol were recorded in the range of 200-800 nm. The scaled wavenumbers are compared with the experimental values. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The formation of hydrogen bond was investigated in terms of the charge density by the NBO calculations. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands were carried out. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.

  13. Experimental Analysis of Preschool Playmate Preferences as a Function of Smiles and Sex

    ERIC Educational Resources Information Center

    Schultz, David; Ambike, Archana; Buckingham-Howes, Stacy; Cheah, Charissa S. L.

    2008-01-01

    Differential emotions theory (DET) ("The face of emotion." Appleton-Century-Crofts: East Norwalk, CT, 1971) posits that the smile functions in part to communicate and/or reflect social affiliation and plays an important role in children's social development. While children's positive emotion expressions have received attention from peer relations…

  14. Effects of Tetramethylpyrazine on Functional Recovery and Neuronal Dendritic Plasticity after Experimental Stroke

    PubMed Central

    Lin, Jun-Bin; Zheng, Chan-Juan; Zhang, Xuan; Chen, Juan; Liao, Wei-Jing; Wan, Qi

    2015-01-01

    The 2,3,5,6-tetramethylpyrazine (TMP) has been widely used in the treatment of ischemic stroke by Chinese doctors. Here, we report the effects of TMP on functional recovery and dendritic plasticity after ischemic stroke. A classical model of middle cerebral artery occlusion (MCAO) was established in this study. The rats were assigned into 3 groups: sham group (sham operated rats treated with saline), model group (MCAO rats treated with saline) and TMP group (MCAO rats treated with 20 mg/kg/d TMP). The neurological function test of animals was evaluated using the modified neurological severity score (mNSS) at 3 d, 7 d, and 14 d after MCAO. Animals were euthanized for immunohistochemical labeling to measure MAP-2 levels in the peri-infarct area. Golgi-Cox staining was performed to test effect of TMP on dendritic plasticity at 14 d after MCAO. TMP significantly improved neurological function at 7 d and 14 d after ischemia, increased MAP-2 level at 14 d after ischemia, and enhanced spine density of basilar dendrites. TMP failed to affect the spine density of apical dendrites and the total dendritic length. Data analyses indicate that there was significant negative correlation between mNSS and plasticity measured at 14 d after MCAO. Thus, enhanced dendritic plasticity contributes to TMP-elicited functional recovery after ischemic stroke. PMID:26379744

  15. [Functional alterations of the arterial vessels in experimental models of type 1 diabetes mellitus].

    PubMed

    Boleeva, G S; Mochalov, S V; Tarasova, O S

    2014-01-01

    The review analyzws the literature on the pathological alterations of endothelium, smooth muscle and vasomotor innervation of arterial vessels in animal modes of type 1 diabetes mellitus. Particular attention is paid t the analysis of mechanisms of diabetic abnormalities in the light of modern knowledge on the functioning of the main components of the vascular wall. PMID:25707261

  16. Integrating Formal and Functional Approaches to Language Teaching in French Immersion: An Experimental Study.

    ERIC Educational Resources Information Center

    Day, Elaine M.; Shapson, Stan M.

    2001-01-01

    Evaluated the effect on French language proficiency of an integrated formal, analytic and functional, communicative approach to second language teaching in the immersion classroom. Impetus for the study arises from previous research indicating that immersion children show persistent weaknesses in their grammatical skills despite the fluent,…

  17. Microvascular function at the margins of early experimental myocardial infarcts in isolated rabbit hearts.

    PubMed

    Sage, M D; Gavin, J B

    1986-01-01

    Injection of low-viscosity resin was used to identify in situ functional blood vessels at the margins of developing regional myocardial infarcts. The ventral interventricular branch (VIB) of the left coronary artery was occluded for 0-240 min in 20 isolated perfused rabbit hearts. After perfusion fixation with glutaraldehyde, resin was injected into the coronary arteries--that injected into the VIB contained dispersed lead dioxide and that injected into the remainder of the heart contained Fat Red 7B dye. This allowed macroscopic and microscopic identification of functional blood vessels. Following transmural freeze fracture, left ventricles were examined using back-scattered electron imaging in a scanning electron microscope. Close to 60% of capillaries in nonischemic myocardium allowed the passage of resin. Thirty minutes of ischemia produced a hyperemic increase to 80%-90% in the proportion of filled vessels. After 60 min, however, a severe reperfusion defect corresponding to the "no-reflow" phenomenon had developed, with virtually all vessels collapsed and less than 10% functional. Among the structurally normal myocytes adjacent to the infarct margin there was a significant reduction (to 30%-40%) in the proportion of functional capillaries. This was due to groups of dilated vessels which were not accessible to arterial supply. Although these marginal "low-flow" regions were of small volume at any one point in time, they seem likely to contribute to the progression of ischemic necrosis, and are probably nonfunctional due to the compression of their venous drainage traversing the infarct.

  18. Diffusion Tensor Imaging as a Predictor of Locomotor Function after Experimental Spinal Cord Injury and Recovery

    PubMed Central

    Kelley, Brian J.; Harel, Noam Y.; Kim, Chang-Yeon; Papademetris, Xenophon; Coman, Daniel; Wang, Xingxing; Hasan, Omar; Kaufman, Adam; Globinsky, Ronen; Staib, Lawrence H.; Cafferty, William B.J.; Hyder, Fahmeed

    2014-01-01

    Abstract Traumatic spinal cord injury (SCI) causes long-term disability with limited functional recovery linked to the extent of axonal connectivity. Quantitative diffusion tensor imaging (DTI) of axonal integrity has been suggested as a potential biomarker for prognostic and therapeutic evaluation after trauma, but its correlation with functional outcomes has not been clearly defined. To examine this application, female Sprague-Dawley rats underwent midthoracic laminectomy followed by traumatic spinal cord contusion of differing severities or laminectomy without contusion. Locomotor scores and hindlimb kinematic data were collected for 4 weeks post-injury. Ex vivo DTI was then performed to assess axonal integrity using tractography and fractional anisotropy (FA), a numerical measure of relative white matter integrity, at the injury epicenter and at specific intervals rostral and caudal to the injury site. Immunohistochemistry for tissue sparing was also performed. Statistical correlation between imaging data and functional performance was assessed as the primary outcome. All injured animals showed some recovery of locomotor function, while hindlimb kinematics revealed graded deficits consistent with injury severity. Standard T2 magnetic resonance sequences illustrated conventional spinal cord morphology adjacent to contusions while corresponding FA maps indicated graded white matter pathology within these adjacent regions. Positive correlations between locomotor (Basso, Beattie, and Bresnahan score and gait kinematics) and imaging (FA values) parameters were also observed within these adjacent regions, most strongly within caudal segments beyond the lesion. Evaluation of axonal injury by DTI provides a mechanism for functional recovery assessment in a rodent SCI model. These findings suggest that focused DTI analysis of caudal spinal cord should be studied in human cases in relationship to motor outcome to augment outcome biomarkers for clinical cases. PMID

  19. [Effect of taurine on the functional status of the insular apparatus and adrenal cortex of the rat with experimental diabetes].

    PubMed

    Mizina, T Iu; Dokshina, G A

    1987-01-01

    The effect of taurine on the regulation of function of the insular apparatus and adrenal cortex of rats with experimental alloxan diabetes was studied. The assessment of the state of the endocrine glands was based on the determination of the content of immunoreactive insulin, total, free and protein-bound 11-oxycorticosteroids (11-OCS) in the blood of rats and a study of the secretory ability of the adrenals and pancreatic fragments in vitro. A single administration of taurine (300 mg/kg per os) to the rats with experimental alloxan diabetes was accompanied by the reduction of the content of immunoreactive insulin, total and free 11-OCS in the blood, a secretory ability of the adrenal cortex and insulin excretory function of the pancreas. The ability of the pancreatic islet tissue to produce insulin in vitro in response to the natural stimulator glucose was disturbed in the rats with experimental diabetes. Taurine (12 mumol/ml) added to the incubation medium containing isolated adrenals and fragments of the pancreas from the diabetic animals, caused a decrease in a high secretory ability of the cortical substance of the adrenal glands and a partial reduction of the insulin secretory ability of the pancreatic tissue.

  20. Continuous and noninvasive hemoglobin monitoring reduces red blood cell transfusion during neurosurgery: a prospective cohort study.

    PubMed

    Awada, Wael N; Mohmoued, Maher F; Radwan, Tarek M; Hussien, Gomaa Z; Elkady, Hany W

    2015-12-01

    Continuous, noninvasive hemoglobin (SpHb) monitoring provides clinicians with the trending of changes in hemoglobin, which has the potential to alter red blood cell transfusion decision making. The objective of this study was to evaluate the impact of SpHb monitoring on blood transfusions in high blood loss surgery. In this prospective cohort study, eligible patients scheduled for neurosurgery were enrolled into either a Control Group or an intervention group (SpHb Group). The Control Group received intraoperative hemoglobin monitoring by intermittent blood sampling when there was an estimated 15% blood loss. If the laboratory value indicated a hemoglobin level of ≤10 g/dL, a red blood cell transfusion was started and continued until the estimated blood loss was replaced and a laboratory hemoglobin value was >l0 g/dL. In the SpHb Group patients were monitored with a Radical-7 Pulse CO-Oximeter for continuous noninvasive hemoglobin values. Transfusion was started when the SpHb value fell to ≤l0 g/dL and was continued until the SpHb was ≥l0 g/dL. Blood samples were taken pre and post transfusion. Percent of patients transfused, average amount of blood transfused in those who received transfusions and the delay time from the hemoglobin reading of <10 g/dL to the start of transfusion (transfusion delay) were compared between groups. The trending ability of SpHb, and the bias and precision of SpHb compared to the laboratory hemoglobin were calculated. Compared to the Control Group, the SpHb Group had fewer units of blood transfused (1.0 vs 1.9 units for all patients; p ≤ 0.001, and 2.3 vs 3.9 units in patients receiving transfusions; p ≤ 0.0 l), fewer patients receiving >3 units (32 vs 73%; p ≤ 0.01) and a shorter time to transfusion after the need was established (9.2 ± 1.7 vs 50.2 ± 7.9 min; p ≤ 0.00 l). The absolute accuracy of SpHb was 0.0 ± 0.8 g/dL and trend accuracy yielded a coefficient of determination of 0.93. Adding SpHb monitoring to

  1. Parental Evaluation of a Nurse Practitioner-Developed Pediatric Neurosurgery Website

    PubMed Central

    Vogel, Tina Kovacs; Kleib, Manal; Davidson, Sandra J

    2016-01-01

    Background Parents often turn to the Internet to seek health information about their child’s diagnosis and condition. Information, support, and resources regarding pediatric neurosurgery are scarce, hard to find, and difficult to comprehend. To address this gap, a pediatric nurse practitioner designed a website called the Neurosurgery Kids Fund (NKF). Analyzing the legitimacy of the NKF website for parents seeking health information and fulfilling their social and resource needs is critical to the website’s future development and success. Objective To explore parental usage of the NKF website, track visitor behavior, evaluate usability and design, establish ways to improve user experience, and identify ways to redesign the website. The aim of this study was to assess and evaluate whether a custom-designed health website could meet parents’ health information, support, and resource needs. Methods A multimethod approach was used. Google Analytic usage reports were collected and analyzed for the period of April 23, 2013, to November 30, 2013. Fifty-two online questionnaires that targeted the website’s usability were collected between June 18, 2014, and July 30, 2014. Finally, a focus group was conducted on August 20, 2014, to explore parents’ perceptions and user experiences. Findings were analyzed using an inductive content analysis approach. Results There were a total of 2998 sessions and 8818 page views, with 2.94 pages viewed per session, a 56.20% bounce rate, an average session duration of 2 minutes 24 seconds, and a 56.24% new sessions rate. Results from 52 eligible surveys included that the majority of NKF users were Caucasian (90%), females (92%), aged 36-45 years (48%), with a university or college degree or diploma (69%). Half plan to use the health information. Over half reported turning to the Internet for health information and spending 2 to 4 hours a day online. The most common reasons for using the NKF website were to (1) gather information

  2. Continuous and noninvasive hemoglobin monitoring reduces red blood cell transfusion during neurosurgery: a prospective cohort study.

    PubMed

    Awada, Wael N; Mohmoued, Maher F; Radwan, Tarek M; Hussien, Gomaa Z; Elkady, Hany W

    2015-12-01

    Continuous, noninvasive hemoglobin (SpHb) monitoring provides clinicians with the trending of changes in hemoglobin, which has the potential to alter red blood cell transfusion decision making. The objective of this study was to evaluate the impact of SpHb monitoring on blood transfusions in high blood loss surgery. In this prospective cohort study, eligible patients scheduled for neurosurgery were enrolled into either a Control Group or an intervention group (SpHb Group). The Control Group received intraoperative hemoglobin monitoring by intermittent blood sampling when there was an estimated 15% blood loss. If the laboratory value indicated a hemoglobin level of ≤10 g/dL, a red blood cell transfusion was started and continued until the estimated blood loss was replaced and a laboratory hemoglobin value was >l0 g/dL. In the SpHb Group patients were monitored with a Radical-7 Pulse CO-Oximeter for continuous noninvasive hemoglobin values. Transfusion was started when the SpHb value fell to ≤l0 g/dL and was continued until the SpHb was ≥l0 g/dL. Blood samples were taken pre and post transfusion. Percent of patients transfused, average amount of blood transfused in those who received transfusions and the delay time from the hemoglobin reading of <10 g/dL to the start of transfusion (transfusion delay) were compared between groups. The trending ability of SpHb, and the bias and precision of SpHb compared to the laboratory hemoglobin were calculated. Compared to the Control Group, the SpHb Group had fewer units of blood transfused (1.0 vs 1.9 units for all patients; p ≤ 0.001, and 2.3 vs 3.9 units in patients receiving transfusions; p ≤ 0.0 l), fewer patients receiving >3 units (32 vs 73%; p ≤ 0.01) and a shorter time to transfusion after the need was established (9.2 ± 1.7 vs 50.2 ± 7.9 min; p ≤ 0.00 l). The absolute accuracy of SpHb was 0.0 ± 0.8 g/dL and trend accuracy yielded a coefficient of determination of 0.93. Adding SpHb monitoring to

  3. A curious experiment: the paradigm switch from observation and speculation to experimentation, in the understanding of neuromuscular function and disease.

    PubMed

    Pearn, John

    2002-08-01

    The four-link chain of the motor unit represents the contemporary end-point of some two millennia of evolving knowledge in neuroscience. The paradigm shift in neuromuscular epistemology occurred in the mid-17th century. In 1666, the newly graduated Dutch doctor, Jan Swammerdam (1637-1680) published his former investigations of dissected nerve-muscle preparations. These experiments comprised the quantum leap from observation and speculation, to that of experimentation in the field of neuroanatomy and neurophysiology. In what he termed 'A Curious Experiment' he also described the phenomenon of intrinsic muscle excitability - "I cannot observe that the muscle in the living animal ever absolutely ceases from all motion". Eighty years later (1752), von Haller demonstrated experimentally that irritability (contractility) was an intrinsic property of all muscular tissue; and distinguished between the sensibility of nerve impulses and the irritability of muscular contraction. This experimental progression from Swammerdam to von Haller culminated in 1850, when Claude Bernard's studies in experimental pharmacology confirmed that muscle was a functional unit, independent of any electrical innervation via its supplying nerve. This account comprises an audit of Swammerdam's work in the perspective of neuromuscular knowledge.

  4. The Wave Function as Matter Density: Ontological Assumptions and Experimental Consequences

    NASA Astrophysics Data System (ADS)

    Jääskeläinen, Markku

    2015-06-01

    The wavefunction is the central mathematical entity of quantum mechanics, but it still lacks a universally accepted interpretation. Much effort is spent on attempts to probe its fundamental nature. Here I investigate the consequences of a matter ontology applied to spherical masses of constant bulk density. The governing equation for the center-of-mass wavefunction is derived and solved numerically. The ground state wavefunctions and resulting matter densities are investigated. A lowering of the density from its bulk value is found for low masses due to increased spatial spreading. A discussion of the possibility to experimentally observe these effects is given and the possible consequences for choosing an ontological interpretation for quantum mechanics are commented upon.

  5. Striatal Cholinergic Interneurons Control Motor Behavior and Basal Ganglia Function in Experimental Parkinsonism.

    PubMed

    Maurice, Nicolas; Liberge, Martine; Jaouen, Florence; Ztaou, Samira; Hanini, Marwa; Camon, Jeremy; Deisseroth, Karl; Amalric, Marianne; Kerkerian-Le Goff, Lydia; Beurrier, Corinne

    2015-10-27

    Despite evidence showing that anticholinergic drugs are of clinical relevance in Parkinson's disease (PD), the causal role of striatal cholinergic interneurons (CINs) in PD pathophysiology remains elusive. Here, we show that optogenetic inhibition of CINs alleviates motor deficits in PD mouse models, providing direct demonstration for their implication in parkinsonian motor dysfunctions. As neural correlates, CIN inhibition in parkinsonian mice differentially impacts the excitability of striatal D1 and D2 medium spiny neurons, normalizes pathological bursting activity in the main basal ganglia output structure, and increases the functional weight of the direct striatonigral pathway in cortical information processing. By contrast, CIN inhibition in non-lesioned mice does not affect locomotor activity, equally modulates medium spiny neuron excitability, and does not modify spontaneous or cortically driven activity in the basal ganglia output, suggesting that the role of these interneurons in motor function is highly dependent on dopamine tone. PMID:26489458

  6. Experimental and theoretical advances in functional understanding of flavonoids as anti-tumor agents.

    PubMed

    Babu, Bandarugattu V; Konduru, Naveen K; Nakanishi, Waro; Hayashi, Satoko; Ahmed, Naseem; Mitrasinovic, Petar M

    2013-02-01

    The potential of flavonoids to act as anti-tumor agents has been recognized but not fully understood because flavonoids are acting at several stages in cancer progression with distinct structure-function relationships. A whole family of structurally different flavonoids is herein described by reviewing some critical aspects of their pro-oxidant behavior in vitro/vivo and in cell systems by which they may work as antioxidants. Different classes of flavonoids (chalcones, flavones, isoflavones, flavanols, flavanones and anthocyanins) are synthetically mimicked using natural product structure-antioxidant activity relationships that are relevant for their enhanced function against cancer as well as severe inflammation conditions under which an increased oxidative stress is often implicated. In the context of the common mechanisms of flavonoid action, clinical data on benefits of flavonoids in fighting against cancer are discussed. A structural basis needed to improve antioxidant activity of these agents is elaborated in more detail.

  7. Time constants and feedback transfer functions of EBR-II (Experimental Breeder Reactor) subassembly types

    SciTech Connect

    Grimm, K.N.; Meneghetti, D.

    1986-09-01

    Time constants, feedback reactivity transfer functions and power coefficients are calculated for stereotypical subassemblies in the EBR-II reactor. These quantities are calculated from nodal reactivities obtained from a reactor kinetic code analysis for a step change in power. Due to the multiplicity of eigenvalues, there are several time constants for each nodal position in a subassembly. Compared with these calculated values are analytically derived values for the initial node of a given channel.

  8. Functional heterogeneity and differential priming of circulating neutrophils in human experimental endotoxemia.

    PubMed

    Pillay, Janesh; Ramakers, Bart P; Kamp, Vera M; Loi, Adele Lo Tam; Lam, Siu W; Hietbrink, Falco; Leenen, Luke P; Tool, Anton T; Pickkers, Peter; Koenderman, Leo

    2010-07-01

    Neutrophils play an important role in host defense. However, deregulation of neutrophils contributes to tissue damage in severe systemic inflammation. In contrast to complications mediated by an overactive neutrophil compartment, severe systemic inflammation is a risk factor for development of immune suppression and as a result, infectious complications. The role of neutrophils in this clinical paradox is poorly understood, and in this study, we tested whether this paradox could be explained by distinct neutrophil subsets and their functionality. We studied the circulating neutrophil compartment immediately after induction of systemic inflammation by administering 2 ng/kg Escherichia coli LPS i.v. to healthy volunteers. Neutrophils were phenotyped by expression of membrane receptors visualized by flow cytometry, capacity to interact with fluorescently labeled microbes, and activation of the NADPH-oxidase by oxidation of Amplex Red and dihydrorhodamine. After induction of systemic inflammation, expression of membrane receptors on neutrophils, such as CXCR1 and -2 (IL-8Rs), C5aR, FcgammaRII, and TLR4, was decreased. Neutrophils were also refractory to fMLF-induced up-regulation of membrane receptors, and suppression of antimicrobial function was shown by decreased interaction with Staphylococcus epidermis. Simultaneously, activation of circulating neutrophils was demonstrated by a threefold increase in release of ROS. The paradoxical phenotype can be explained by the selective priming of the respiratory burst. In contrast, newly released, CD16(dim) banded neutrophils display decreased antimicrobial function. We conclude that systemic inflammation leads to a functionally heterogeneous neutrophil compartment, in which newly released refractory neutrophils can cause susceptibility to infections, and activated, differentiated neutrophils can mediate tissue damage. PMID:20400675

  9. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    SciTech Connect

    Viitanen, Matti; Sundström, Erik; Baumann, Marc; Tikka, Saara

    2013-02-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ{sub m}) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  10. Functional data analysis of experimental parameters obtained in PVA doped CdCl2 polymer composites

    NASA Astrophysics Data System (ADS)

    Prakash, M. B. Nanda; Urs, Gopal Krishne; Somashekar, R.

    2016-05-01

    Using solution casting method, PVA based polymer composites films with various concentrations of CdCl2 were prepared. Prepared polymer composites films were investigated using XRD. Crystallite size for different concentrations of CdCl2 are computed here using Williamson and Hall plot (WH plot), an in-house program developed by us. To correlate between two independent physical parameters size and conductivity, we have chosen functional data analysis to estimate the maxima and minima in these polymer composites systems.

  11. Experimental warming alters potential function of the fungal community in boreal forest.

    PubMed

    Treseder, Kathleen K; Marusenko, Yevgeniy; Romero-Olivares, Adriana L; Maltz, Mia R

    2016-10-01

    Fungal community composition often shifts in response to warmer temperatures, which might influence decomposition of recalcitrant carbon (C). We hypothesized that evolutionary trade-offs would enable recalcitrant C-using taxa to respond more positively to warming than would labile C-using taxa. Accordingly, we performed a warming experiment in an Alaskan boreal forest and examined changes in the prevalence of fungal taxa. In a complementary field trial, we characterized the ability of fungal taxa to use labile C (glucose), intermediate C (hemicellulose or cellulose), or recalcitrant C (lignin). We also assigned taxa to functional groups (e.g., free-living filamentous fungi, ectomycorrhizal fungi, and yeasts) based on taxonomic identity. We found that response to warming varied most among taxa at the order level, compared to other taxonomic ranks. Among orders, ability to use lignin was significantly related to increases in prevalence in response to warming. However, the relationship was weak, given that lignin use explained only 9% of the variability in warming responses. Functional groups also differed in warming responses. Specifically, free-living filamentous fungi and ectomycorrhizal fungi responded positively to warming, on average, but yeasts responded negatively. Overall, warming-induced shifts in fungal communities might be accompanied by an increased ability to break down recalcitrant C. This change in potential function may reduce soil C storage under global warming.

  12. Parthenogenetic dopamine neurons from primate embryonic stem cells restore function in experimental Parkinson's disease

    PubMed Central

    Lee, Hyojin; Patterson, Michaela; Reske-Nielsen, Casper; Yoshizaki, Takahito; Sonntag, Kai C.; Studer, Lorenz; Isacson, Ole

    2008-01-01

    The identity and functional potential of dopamine neurons derived in vitro from embryonic stem cells are critical for the development of a stem cell-based replacement therapy for Parkinson's disease. Using a parthenogenetic primate embryonic stem cell line, we have generated dopamine neurons that display persistent expression of midbrain regional and cell-specific transcription factors, which establish their proper identity and allow for their survival. We show here that transplantation of parthenogenetic dopamine neurons restores motor function in hemi-parkinsonian, 6-hydroxy-dopamine-lesioned rats. Exposure to Wnt5a and fibroblast growth factors (FGF) 20 and 2 at the final stage of in vitro differentiation enhanced the survival of dopamine neurons and, correspondingly, the extent of motor recovery of transplanted animals. Importantly for future development of clinical applications, dopamine neurons were post-mitotic at the time of transplantation and there was no tumour formation. These data provide proof for the concept that parthenogenetic stem cells are a suitable source of functional neurons for therapeutic applications. PMID:18669499

  13. Tetradecylthioacetic acid increases fat metabolism and improves cardiac function in experimental heart failure.

    PubMed

    Øie, Erik; Berge, Rolf K; Ueland, Thor; Dahl, Christen P; Edvardsen, Thor; Beitnes, Jan Otto; Bohov, Pavol; Aukrust, Pål; Yndestad, Arne

    2013-02-01

    Changes in myocardial metabolism, including a shift from fatty acid to glucose utilization and changes in fatty acid availability and composition are characteristics of heart failure development. Tetradecylthioacetic acid (TTA) is a fatty acid analogue lacking the ability to undergo mitochondrial β-oxidation. TTA promotes hepatic proliferation of mitochondria and peroxisomes and also decreases serum triglycerides and cholesterol in animals. We investigated the effect of TTA, in combination with a high-fat or regular diet, in a rat model of post-myocardial infarction heart failure. TTA had a beneficial effect on cardiac function in post-myocardial infarction heart failure without affecting myocardial remodeling. These effects of TTA on myocardial function were accompanied by decreased free fatty acids in plasma, increased myocardial proportion of n-3 polyunsaturated fatty acids (PUFA) and a decreased proportion of n-6 PUFA. Myocardial enzyme gene expression during TTA treatment suggested that the increase in n-3 PUFA could reflect increased n-3 PUFA synthesis and inadequately increased n-3 PUFA β-oxidation. Based on our data, it is unlikely that the changes are secondary to alterations in other tissues as plasma and liver showed an opposite pattern with decreased n-3 PUFA during TTA treatment. The present study suggests that TTA may improve myocardial function in heart failure, potentially involving its ability to decrease the availability of FFA and increase the myocardial proportion of n-3 PUFA. PMID:23266898

  14. Experimental warming alters potential function of the fungal community in boreal forest.

    PubMed

    Treseder, Kathleen K; Marusenko, Yevgeniy; Romero-Olivares, Adriana L; Maltz, Mia R

    2016-10-01

    Fungal community composition often shifts in response to warmer temperatures, which might influence decomposition of recalcitrant carbon (C). We hypothesized that evolutionary trade-offs would enable recalcitrant C-using taxa to respond more positively to warming than would labile C-using taxa. Accordingly, we performed a warming experiment in an Alaskan boreal forest and examined changes in the prevalence of fungal taxa. In a complementary field trial, we characterized the ability of fungal taxa to use labile C (glucose), intermediate C (hemicellulose or cellulose), or recalcitrant C (lignin). We also assigned taxa to functional groups (e.g., free-living filamentous fungi, ectomycorrhizal fungi, and yeasts) based on taxonomic identity. We found that response to warming varied most among taxa at the order level, compared to other taxonomic ranks. Among orders, ability to use lignin was significantly related to increases in prevalence in response to warming. However, the relationship was weak, given that lignin use explained only 9% of the variability in warming responses. Functional groups also differed in warming responses. Specifically, free-living filamentous fungi and ectomycorrhizal fungi responded positively to warming, on average, but yeasts responded negatively. Overall, warming-induced shifts in fungal communities might be accompanied by an increased ability to break down recalcitrant C. This change in potential function may reduce soil C storage under global warming. PMID:26836961

  15. Natural dye extracted from karkadah and its application in dye-sensitized solar cells: experimental and density functional theory study.

    PubMed

    Reda, S M; Soliman, K A

    2016-02-01

    This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100  mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed.

  16. Natural dye extracted from karkadah and its application in dye-sensitized solar cells: experimental and density functional theory study.

    PubMed

    Reda, S M; Soliman, K A

    2016-02-01

    This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100  mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed. PMID:26836089

  17. Advances in experimental methods for the elucidation of Pseudomonas syringae effector function with a focus on AvrPtoB

    PubMed Central

    Munkvold, Kathy R.; Martin, Gregory B.

    2010-01-01

    SUMMARY Pseudomonas syringae infects a wide range of plant species through the use of a type III secretion system. The effector proteins injected into the plant cell through this molecular syringe serve as promoters of disease by subverting the plant immune response to the benefit of the bacteria in the intercellular space. The targets and activities of a subset of effectors have been elucidated recently. In this article, we focus on the experimental approaches that have proved most successful in probing the molecular basis of effectors, ranging from loss-of-function to gain-of-function analyses utilizing several techniques for effector delivery into plants. In particular, we highlight how these diverse approaches have been applied to the study of one effector—AvrPtoB—a multifunctional protein with the ability to suppress both effector-triggered immunity and pathogen (or microbe)-associated molecular pattern-triggered immunity. Taken together, advances in this field illustrate the need for multiple experimental approaches when elucidating the function of a single effector. PMID:19849784

  18. Experimental verification of a real-time compensation functionality for dose changes due to target motion in scanned particle therapy

    SciTech Connect

    Luechtenborg, Robert; Saito, Nami; Durante, Marco; Bert, Christoph

    2011-10-15

    Purpose: Implementation and experimental assessment of a real-time dose compensation system for beam tracking in scanned carbon beam therapy of intrafractionally moving targets. Methods: A real-time dose compensation functionality has been developed and implemented at the experimental branch of the beam tracking system at GSI Helmholtzzentrum fuer Schwerionenforschung (GSI). Treatment plans for different target geometries have been optimized. They have been delivered using scanned carbon ions with beam tracking (BT) and real-time dose compensation combined with beam tracking (RDBT), respectively. Target motion was introduced by a rotating table. Dose distributions were assessed by ionization chamber measurements and dose reconstructions. These distributions have been compared to stationary delivery for BT as well as RDBT. Additionally simulations have been performed to investigate the dependence of delivered dose distributions on varying motion starting phases for BT and RDBT, respectively. Results: Average measured dose differences between static delivery and motion influenced delivery could be reduced from 27-68 mGy when BT was used to 12-37 mGy when RDBT was used. Nominal dose was 1000 mGy. Simulated dose deliveries showed improvements in dose delivery and robustness against varying starting motion phases when RDBT was used. Conclusions: A real-time dose compensation functionality extending the existing beam tracking functionality has been implemented and verified by measurements. Measurements and simulated dose deliveries show that real-time dose compensation can substantially improve delivered dose distributions for large rotational target motion compared to beam tracking alone.

  19. DHA protects against experimental colitis in IL-10-deficient mice associated with the modulation of intestinal epithelial barrier function.

    PubMed

    Zhao, Jie; Shi, Peiliang; Sun, Ye; Sun, Jing; Dong, Jian-Ning; Wang, Hong-Gang; Zuo, Lu-Gen; Gong, Jian-Feng; Li, Yi; Gu, Li-Li; Li, Ning; Li, Jie-Shou; Zhu, Wei-Ming

    2015-07-01

    A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10(-/-)) at 16 weeks of age with established colitis were treated with DHA (i.g. 35.5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10(-/-) mice by improving the intestinal epithelial barrier function.

  20. Relationship of dietary iodide and drinking water disinfectants to thyroid function in experimental animals

    SciTech Connect

    Revis, N.W.; McCauley, P.; Holdsworth, G.

    1986-11-01

    The importance of dietary iodide on the reported hypothyroid effect of drinking water disinfectants on thyroid function was investigated. Previous studies have also showed differences in the relative sensitivity of pigeons and rabbits to chlorinated water. Pigeons and rabbits were exposed for 3 months to diets containing high (950 ppb) or low (300 ppb) levels of iodide and to drinking water containing two levels of chlorine. Results showed that the high-iodide diet prevented the hypothyroid effect observed in pigeons given the low-iodide diet and chlorinated drinking water. Similar trends were observed in rabbits exposed to the same treatment; however, significant hypothyroid effects were not observed in this animal model. The factor associated with the observed effect of dietary iodide on the chlorine-induced change in thyroid function is unknown, as is the relative sensitivity of rabbits and pigeons to the effect of chlorine. Several factors may explain the importance of dietary iodide and the relative sensitivity of these species. For example, the iodine formed by the known reaction of chlorine with iodide could result in a decrease in the plasma level of iodide because of the relative absorption rates of iodide and iodine in the intestinal tract, and the various types and concentrations of chloroorganics (metabolites) formed in the diet following the exposure of various dietary constituents to chlorine could affect the thyroid function. The former factor was investigated in the present studies. Results do not confirm a consistent, significant reduction in the plasma level of iodide in rabbits and pigeons exposed to chlorinated water and the low-iodide diet. The latter factor is being investigated.

  1. Experimental demonstration of using divergence cost-function in SPGD algorithm for coherent beam combining with tip/tilt control.

    PubMed

    Geng, Chao; Luo, Wen; Tan, Yi; Liu, Hongmei; Mu, Jinbo; Li, Xinyang

    2013-10-21

    A novel approach of tip/tilt control by using divergence cost function in stochastic parallel gradient descent (SPGD) algorithm for coherent beam combining (CBC) is proposed and demonstrated experimentally in a seven-channel 2-W fiber amplifier array with both phase-locking and tip/tilt control, for the first time to our best knowledge. Compared with the conventional power-in-the-bucket (PIB) cost function for SPGD optimization, the tip/tilt control using divergence cost function ensures wider correction range, automatic switching control of program, and freedom of camera's intensity-saturation. Homemade piezoelectric-ring phase-modulator (PZT PM) and adaptive fiber-optics collimator (AFOC) are developed to correct piston- and tip/tilt-type aberrations, respectively. The PIB cost function is employed for phase-locking via maximization of SPGD optimization, while the divergence cost function is used for tip/tilt control via minimization. An average of 432-μrad of divergence metrics in open loop has decreased to 89-μrad when tip/tilt control implemented. In CBC, the power in the full width at half maximum (FWHM) of the main lobe increases by 32 times, and the phase residual error is less than λ/15. PMID:24150347

  2. Experimental Gestational Diabetes Mellitus Induces Blunted Vasoconstriction and Functional Changes in the Rat Aorta

    PubMed Central

    Tufiño, Cecilia; Villanueva-López, Cleva; Ibarra-Barajas, Maximiliano; Bracho-Valdés, Ismael; Bobadilla-Lugo, Rosa Amalia

    2014-01-01

    Diabetic conditions increase vascular reactivity to angiotensin II in several studies but there are scarce reports on cardiovascular effects of hypercaloric diet (HD) induced gestational diabetes mellitus (GDM), so the objective of this work was to determine the effects of HD induced GDM on vascular responses. Angiotensin II as well as phenylephrine induced vascular contraction was tested in isolated aorta rings with and without endothelium from rats fed for 7 weeks (4 before and 3 weeks during pregnancy) with standard (SD) or hypercaloric (HD) diet. Also, protein expression of AT1R, AT2R, COX-1, COX-2, NOS-1, and NOS-3 and plasma glucose, insulin, and angiotensin II levels were measured. GDM impaired vasoconstrictor response (P < 0.05 versus SD) in intact (e+) but not in endothelium-free (e−) vessels. Losartan reduced GDM but not SD e− vasoconstriction (P < 0.01 versus SD). AT1R, AT2R, and COX-1 and COX-2 protein expression were significantly increased in GDM vessels (P < 0.05 versus SD). Results suggest an increased participation of endothelium vasodilator mediators, probably prostaglandins, as well as of AT2 vasodilator receptors as a compensatory mechanism for vasoconstrictor changes generated by experimental GDM. Considering the short term of rat pregnancy findings can reflect early stage GDM adaptations. PMID:25610861

  3. Antibacterial functionalization of an experimental self-etching primer by inorganic agents: microbiological and biocompatibility evaluations.

    PubMed

    Fang, Ming; Chai, Feng; Chen, Ji-Hua; Neut, Christel; Jia, Min; Liu, Yi; Zhao, San-Jun; Hildebrand, Hartmut F

    2007-11-01

    Antibacterial activities have been demonstrated on oral bacteria with inorganic antibacterial agents (ABAs) after their incorporations into an experimental self-etching primer (ESP) before curing. This study was to assess their biocompatibility and antibacterial activity after curing. Six ABAs were incorporated respectively into ESP for treating specimens. After curing, their bactericidal activities on Streptococcus mutans and influences to the early bacterial colonization were assessed by direct contact and viable count. Systemic toxicity in rats after short-term oral exposure and direct contact cytotoxicity with NIH3T3 fibroblasts were tested. Incorporation of ZnOw AT-83, Longbei antibiotic, Antim-AMS2 or IONPURE-H significantly enhanced the antibacterial effect of ESP after curing, even after 1 month aging. Specimens treated by ESP with ZnOw AT-83, Longbei antibiotic or Antim-AMS2 showed slightly less bacterial adhesion than control. Animal experiments revealed neither toxic signs nor significant differences in body weight gain between control and other groups. Cell vitality or proliferation rates were ranged from 76% to 100% with respect to controls. Basic magnesium hypochlorite, ZnOw AT-83 and ZnOw AT-88 were less toxic. Toxicity only observed in areas beneath the specimens and/or in the direct vicinity of the specimen edge. From microbiological and biocompatibility aspects, the tested ABAs can be effectively incorporated in ESP to provide antibacterial activity against S. mutans. ZnOw AT-83 was the most promising one.

  4. Combined experimental and density functional theory studies of an organic-inorganic hybrid perovskite.

    PubMed

    Kassou, S; El-Mrabet, R; Kaiba, A; Guionneau, P; Belaaraj, A

    2016-04-14

    Single crystals of [C6H5-C2H4-NH3]2ZnCl4 were obtained by slow evaporation at room temperature. Single-Crystal X-Ray Diffraction (SCXRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and UV-Visible spectroscopy were used to characterize the crystal structure, and thermal and optical properties, respectively. At 293 K, PEA-ZnCl4 crystallizes in a monoclinic unit-cell in the P21/c space group a = 7.449(2) Å, b = 24.670(3) Å, c = 11.187(2) Å and β = 91.762(5)°, V = 2054.8(2) Å(3) and Z = 4. The DSC and TGA analyses show respectively the presence of two first order reversible phase transitions and a sample thermal stability below 541 K. The optical study reveals that the compound undergoes a direct optical transition and an energy gap about of Eg = 4.46 eV. In parallel, ab initio DFT calculations are performed to study the electronic band structure, to examine electronic density and to calculate the gap energy value. The calculated values are in good agreement with the experimental data.

  5. [Experimental studies on effects of excessive iodine intake on morphology and function of kidney in mice].

    PubMed

    Zhou, X; Yin, G

    1996-11-01

    To understand that if excessive iodine can cause damage to tissues other than thyroid gland, mice were fed with iodine-excess water and iodine-excess goiter was caused in them. Hisitomorphology and function of the kidney, in addition to the thyroid gland, in goiter mice were observed. Results showed that two hundred days after being fed with 3,000 micrograms iodine per liter water, in addition to causing iodine-excess goiter characterized with proliferation of large amount of colloid in thyroid follicles, morphology and function of the kidneys in mice were significantly damaged, with prominent pathomorphological changes of crescent formation and metabolic inhibition in microsome membrane Na(+)-K(+)-ATPase activities in their kidneys. Na(+)-K(+)-ATPase activities were 21.95 +/- 7.50 mumolPi/mg Pr.hr in low iodine group, and 17.64 +/- 8.63 mumolPi/mg Pr.hr in excessive iodine group, with significant difference. It suggests that excessive iodine can cause damage not only to thyroid, but to the whole body.

  6. The Function of Gas Vesicles in Halophilic Archaeaand Bacteria: Theories and Experimental Evidence

    PubMed Central

    Oren, Aharon

    2012-01-01

    A few extremely halophilic Archaea (Halobacterium salinarum, Haloquadratum walsbyi, Haloferax mediterranei, Halorubrum vacuolatum, Halogeometricum borinquense, Haloplanus spp.) possess gas vesicles that bestow buoyancy on the cells. Gas vesicles are also produced by the anaerobic endospore-forming halophilic Bacteria Sporohalobacter lortetii and Orenia sivashensis. We have extensive information on the properties of gas vesicles in Hbt. salinarum and Hfx. mediterranei and the regulation of their formation. Different functions were suggested for gas vesicle synthesis: buoying cells towards oxygen-rich surface layers in hypersaline water bodies to prevent oxygen limitation, reaching higher light intensities for the light-driven proton pump bacteriorhodopsin, positioning the cells optimally for light absorption, light shielding, reducing the cytoplasmic volume leading to a higher surface-area-to-volume ratio (for the Archaea) and dispersal of endospores (for the anaerobic spore-forming Bacteria). Except for Hqr. walsbyi which abounds in saltern crystallizer brines, gas-vacuolate halophiles are not among the dominant life forms in hypersaline environments. There only has been little research on gas vesicles in natural communities of halophilic microorganisms, and the few existing studies failed to provide clear evidence for their possible function. This paper summarizes the current status of the different theories why gas vesicles may provide a selective advantage to some halophilic microorganisms. PMID:25371329

  7. Getting the timing right: experimental protocols for investigating time with functional neuroimaging and psychopharmacology.

    PubMed

    Coull, Jennifer T

    2014-01-01

    Functional Magnetic Resonance Imaging (fMRI) is an effective tool for identifying brain areas and networks implicated in human timing. But fMRI is not just a phrenological tool: by careful design, fMRI can be used to disentangle discrete components of a timing task and control for the underlying cognitive processes (e.g. sustained attention and WM updating) that are critical for estimating stimulus duration in the range of hundreds of milliseconds to seconds. Moreover, the use of parametric designs and correlational analyses allows us to better understand not just where, but also how, the brain processes temporal information. In addition, by combining fMRI with psychopharmacological manipulation, we can begin to uncover the complex relationship between cognition, neurochemistry and anatomy in the healthy human brain. This chapter provides an overview of some of the key findings in the functional imaging literature of both duration estimation and temporal prediction, and outlines techniques that can be used to allow timing-related activations to be interpreted more unambiguously. In our own studies, we have found that estimating event duration, whether that estimate is provided by a motor response or a perceptual discrimination, typically recruits basal ganglia, SMA and right inferior frontal cortex, and can be modulated by dopaminergic activity in these areas. By contrast, orienting attention to predictable moments in time in order to optimize behaviour, whether that is to speed motor responding or improve perceptual accuracy, recruits left inferior parietal cortex.

  8. A comparison of rectal and intramuscular codeine phosphate in children following neurosurgery.

    PubMed

    McEwan, A; Sigston, P E; Andrews, K A; Hack, H A; Jenkins, A M; May, L; Llewelyn, N; MacKersie, A

    2000-01-01

    Codeine is frequently used for postoperative analgesia in children. Intramuscular injections are not ideal and the rectal route may be preferable. We compared rectal and intramuscular codeine administered following neurosurgery. 20 children (over 3 months) undergoing elective neurosurgical procedures, were randomized to receive either rectal or intramuscular codeine phospate (1 mg.kg-1) at the end of the procedure. Serum levels of codeine and morphine were assayed at intervals following administration (0, 30, 60, 120, 240 min). Fentanyl was the intraoperative analgesic and postoperative rescue analgesia was paracetamol, diclofenac and intramuscular codeine. The Children's Hospital of Eastern Ontario Pain Scale was used to assess analgesia. Peak codeine levels in both groups were observed at 30 min and morphine levels were consistently low. The plasma codeine levels were significantly greater at 30 and 60 min following intramuscular injection, and were associated with slightly better analgesia scores, but did not reach statistical significance. However, the peak plasma level occurred at similar times in both groups. Codeine is absorbed as rapidly via the rectal route compared with the intramuscular route but the peak levels are lower.

  9. A computational model for tracking subsurface tissue deformation during stereotactic neurosurgery.

    PubMed

    Paulsen, K D; Miga, M I; Kennedy, F E; Hoopes, P J; Hartov, A; Roberts, D W

    1999-02-01

    Recent advances in the field of stereotactic neurosurgery have made it possible to coregister preoperative computed tomography (CT) and magnetic resonance (MR) images with instrument locations in the operating field. However, accounting for intraoperative movement of brain tissue remains a challenging problem. While intraoperative CT and MR scanners record concurrent tissue motion, there is motivation to develop methodologies which would be significantly lower in cost and more widely available. The approach we present is a computational model of brain tissue deformation that could be used in conjunction with a limited amount of concurrently obtained operative data to estimate subsurface tissue motion. Specifically, we report on the initial development of a finite element model of brain tissue adapted from consolidation theory. Validations of the computational mathematics in two and three dimensions are shown with errors of 1%-2% for the discretizations used. Experience with the computational strategy for estimating surgically induced brain tissue motion in vivo is also presented. While the predicted tissue displacements differ from measured values by about 15%, they suggest that exploiting a physics-based computational framework for updating preoperative imaging databases during the course of surgery has considerable merit. However, additional model and computational developments are needed before this approach can become a clinical reality. PMID:9932343

  10. "Extremely minimally invasive": recent advances in nanotechnology research and future applications in neurosurgery.

    PubMed

    Mattei, Tobias A; Rehman, Azeem A

    2015-01-01

    The term "nanotechnology" refers to the development of materials and devices that have been designed with specific properties at the nanometer scale (10(-9) m), usually being less than 100 nm in size. Recent advances in nanotechnology have promised to enable visualization and intervention at the subcellular level, and its incorporation to future medical therapeutics is expected to bring new avenues for molecular imaging, targeted drug delivery, and personalized interventions. Although the central nervous system presents unique challenges to the implementation of new therapeutic strategies involving nanotechnology (such as the heterogeneous molecular environment of different CNS regions, the existence of multiple processing centers with different cytoarchitecture, and the presence of the blood-brain barrier), numerous studies have demonstrated that the incorporation of nanotechnology resources into the armamentarium of neurosurgery may lead to breakthrough advances in the near future. In this article, the authors present a critical review on the current 'state-of-the-art' of basic research in nanotechnology with special attention to those issues which present the greatest potential to generate major therapeutic progresses in the neurosurgical field, including nanoelectromechanical systems, nano-scaffolds for neural regeneration, sutureless anastomosis, molecular imaging, targeted drug delivery, and theranostic strategies.

  11. Automatic identification of various nuclei in the basal ganglia for Parkinson's disease neurosurgery.

    PubMed

    Pinzon-Morales, Ruben-Dario; Garces-Arboleda, Maribel; Orozco-Gutierrez, Alvaro-Angel

    2009-01-01

    Stereotactic neurosurgery for Parkinson's disease (PD) is one of the most used treatments for relief symptoms of this degenerative disorder. Current methods include ablation and deep brain stimulation (DBS) that can be applied to the various nuclei in the basal ganglia (BG), for instance to the Subthalamic nucleus (STN) or the Ventral medial nucleus (Vim). Identification of thus regions must be rigorous and within a minimum position error. Usually, skilled specialist identifies the brain area by comparing and listening to the rhythm created by the temporal and spatial aggregation of action potentials presented in microelectrode recordings (MER). We present a novel system for automatic identification of the various nuclei in the BG which addresses the limitations of the subjectivity and the non-stationary nature of MER signals. This system incorporates the time-frequency analysis using the Hilbert-Huang Transform (HHT), which is a recent tool for processing nonlinear and non-stationary data, with a dynamic classifier based on Hidden Markov Models (HMM). Classification accuracy in two different databases is compared to validate the performance of the proposed method. Results show that system can recognize selected nuclei with a mean accuracy of 90%.

  12. Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

    PubMed

    Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

    2015-06-01

    Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

  13. A meningioma and its consequences for American history and the rise of neurosurgery.

    PubMed

    Ansari, Shaheryar F; Gianaris, Nicholas G; Cohen-Gadol, Aaron A

    2011-12-01

    The case of General Leonard Wood is notable both for its contribution to the field of neurosurgery and its historical significance. As one of Harvey Cushing's first successful brain tumor operations in 1910, Wood's surgery was part of the case series that culminated in Cushing's monograph Meningioma. This case was important to the rise of Cushing's career and his recognition as a member of the next generation of neurosurgeons who did not settle for mere bony decompression to taper intracranial tension but who dared to pursue intradural resections-operations that had been performed by surgeons for decades but were frowned upon because of the attendant risks. Cushing's operation to remove a recurrent brain tumor ended Wood's life in 1927. The authors discuss the effects the tumor may have had on Wood's life and career, explore an alternate explanation for the cause of Wood's death, and provide a brief account of the life of General Wood, highlighting events in his military and administrative career juxtaposed against the progression of his illness. Furthermore, the case history of the General is reviewed, using information drawn from the original patient notes and recently discovered images from the Cushing Brain Tumor Registry that elucidate more details about General Wood's story, from the injury that caused his first tumor to his final surgery, leading to his demise. PMID:21854120

  14. Rivaling paradigms in psychiatric neurosurgery: adjustability versus quick fix versus minimal-invasiveness

    PubMed Central

    Müller, Sabine; Riedmüller, Rita; van Oosterhout, Ansel

    2015-01-01

    In the wake of deep brain stimulation (DBS) development, ablative neurosurgical procedures are seeing a comeback, although they had been discredited and nearly completely abandoned in the 1970s because of their unethical practice. Modern stereotactic ablative procedures as thermal or radiofrequency ablation, and particularly radiosurgery (e.g., Gamma Knife) are much safer than the historical procedures, so that a re-evaluation of this technique is required. The different approaches of modern psychiatric neurosurgery refer to different paradigms: microsurgical ablative procedures is based on the paradigm ‘quick fix,’ radiosurgery on the paradigm ‘minimal-invasiveness,’ and DBS on the paradigm ‘adjustability.’ From a mere medical perspective, none of the procedures is absolutely superior; rather, they have different profiles of advantages and disadvantages. Therefore, individual factors are crucial in decision-making, particularly the patients’ social situation, individual preferences, and individual attitudes. The different approaches are not only rivals, but also enriching mutually. DBS is preferable for exploring new targets, which may become candidates for ablative microsurgery or radiosurgery. PMID:25883557

  15. Cost analysis of a project to digitize classic articles in neurosurgery*

    PubMed Central

    Bauer, Kathleen

    2002-01-01

    In summer 2000, the Cushing/Whitney Medical Library at Yale University began a demonstration project to digitize classic articles in neurosurgery from the late 1800s and early 1900s. The objective of the first phase of the project was to measure the time and costs involved in digitization, and those results are reported here. In the second phase, metadata will be added to the digitized articles, and the project will be publicized. Thirteen articles were scanned using optical character recognition (OCR) software, and the resulting text files were carefully proofread. Time for photocopying, scanning, and proofreading were recorded. This project achieved an average cost per item (total pages plus images) of $4.12, a figure at the high end of average costs found in other studies. This project experienced high costs for two reasons. First, the articles contained many images, which required extra processing. Second, the older fonts and the poor condition of many of these articles complicated the OCR process. The average article cost $84.46 to digitize. Although costs were high, the selection of historically important articles maximized the benefit gained from the investment in digitization. PMID:11999182

  16. Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

    2016-03-01

    Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

  17. Neurosurgery Simulation Using Non-linear Finite Element Modeling and Haptic Interaction.

    PubMed

    Lee, Huai-Ping; Audette, Michel; Joldes, Grand Roman; Enquobahrie, Andinet

    2012-02-23

    Real-time surgical simulation is becoming an important component of surgical training. To meet the real-time requirement, however, the accuracy of the biomechancial modeling of soft tissue is often compromised due to computing resource constraints. Furthermore, haptic integration presents an additional challenge with its requirement for a high update rate. As a result, most real-time surgical simulation systems employ a linear elasticity model, simplified numerical methods such as the boundary element method or spring-particle systems, and coarse volumetric meshes. However, these systems are not clinically realistic. We present here an ongoing work aimed at developing an efficient and physically realistic neurosurgery simulator using a non-linear finite element method (FEM) with haptic interaction. Real-time finite element analysis is achieved by utilizing the total Lagrangian explicit dynamic (TLED) formulation and GPU acceleration of per-node and per-element operations. We employ a virtual coupling method for separating deformable body simulation and collision detection from haptic rendering, which needs to be updated at a much higher rate than the visual simulation. The system provides accurate biomechancial modeling of soft tissue while retaining a real-time performance with haptic interaction. However, our experiments showed that the stability of the simulator depends heavily on the material property of the tissue and the speed of colliding objects. Hence, additional efforts including dynamic relaxation are required to improve the stability of the system.

  18. Experimental design and multiple response optimization. Using the desirability function in analytical methods development.

    PubMed

    Candioti, Luciana Vera; De Zan, María M; Cámara, María S; Goicoechea, Héctor C

    2014-06-01

    A review about the application of response surface methodology (RSM) when several responses have to be simultaneously optimized in the field of analytical methods development is presented. Several critical issues like response transformation, multiple response optimization and modeling with least squares and artificial neural networks are discussed. Most recent analytical applications are presented in the context of analytLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, ArgentinaLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, Argentinaical methods development, especially in multiple response optimization procedures using the desirability function.

  19. Omnivory and grazer functional composition moderate cascading trophic effects in experimental Fucus vesiculosus habitats.

    PubMed

    Eriksson, Britas Klemens; van Sluis, Christiaan; Sieben, Katrin; Kautsky, Lena; Råberg, Sonja

    2011-01-01

    We tested the relative strength of direct versus indirect effects of an aquatic omnivore depending on the functional composition of grazers by manipulating the presence of gastropod and amphipod grazers and omnivorous shrimp in outdoor mesocosms. By selectively preying upon amphipods and reducing their abundance by 70-80%, omnivorous shrimp favoured the dominance of gastropods. While gastropods were the main microalgal grazers, amphipods controlled macroalgal biomass in the experiment. However, strong predation on the amphipod by the shrimp had no significant indirect effects on macroalgal biomass, indicating that when amphipod abundances declined, complementary feeding by the omnivore on macroalgae may have suppressed a trophic cascade. Accordingly, in the absence of amphipods, the shrimp grazed significantly on green algae and thereby suppressed the diversity of the macroalgal community. Our experiment demonstrates direct consumer effects by an omnivore on both the grazer and producer trophic levels in an aquatic food web, regulated by prey availability.

  20. Catechin averts experimental diabetes mellitus-induced vascular endothelial structural and functional abnormalities.

    PubMed

    Bhardwaj, Pooja; Khanna, Deepa; Balakumar, Pitchai

    2014-03-01

    Diabetes mellitus is associated with an induction of vascular endothelial dysfunction (VED), an initial event that could lead to the pathogenesis of atherosclerosis and hypertension. Previous studies showed that catechin, a key component of green tea, possesses vascular beneficial effects. We investigated the effect of catechin hydrate in diabetes mellitus-induced experimental vascular endothelial abnormalities (VEA). Streptozotocin (50 mg/kg, i.p., once) administration to rats produced diabetes mellitus, which subsequently induced VEA in 8 weeks by markedly attenuating acetylcholine-induced endothelium-dependent relaxation in the isolated aortic ring preparation, decreasing aortic and serum nitrite/nitrate concentrations and impairing aortic endothelial integrity. These abnormalities in diabetic rats were accompanied with elevated aortic superoxide anion generation and serum lipid peroxidation in addition to hyperglycemia. Catechin hydrate treatment (50 mg/kg/day p.o., 3 weeks) markedly prevented diabetes mellitus-induced VEA and vascular oxidative stress. Intriguingly, in vitro incubation of L-NAME (100 μM), an inhibitor of nitric oxide synthase, or Wortmannin (100 nM), a selective inhibitor of phosphatidylinositol 3-kinase (PI3K), markedly prevented catechin hydrate-induced improvement in acetylcholine-provoked endothelium-dependent relaxation in the diabetic rat aorta. Moreover, catechin hydrate treatment considerably reduced the elevated level of serum glucose in diabetic rats. In conclusion, catechin hydrate treatment prevents diabetes mellitus-induced VED through the activation of endothelial PI3K signal and subsequent activation of eNOS and generation of nitric oxide. In addition, reduction in high glucose, vascular oxidative stress, and lipid peroxidation might additionally contribute to catechin hydrate-associated prevention of diabetic VEA. PMID:24048981

  1. Elevation of serum sphingosine-1-phosphate attenuates impaired cardiac function in experimental sepsis

    PubMed Central

    Coldewey, Sina M.; Benetti, Elisa; Collino, Massimo; Pfeilschifter, Josef; Sponholz, Christoph; Bauer, Michael; Huwiler, Andrea; Thiemermann, Christoph

    2016-01-01

    Serum levels of the lipid mediator sphingosine-1-phosphate (S1P) are reduced in septic patients and are inversely associated with disease severity. We show that serum S1P is reduced in human sepsis and in murine models of sepsis. We then investigated whether pharmacological or genetic approaches that alter serum S1P may attenuate cardiac dysfunction and whether S1P signaling might serve as a novel theragnostic tool in sepsis. Mice were challenged with lipopolysaccharide and peptidoglycan (LPS/PepG). LPS/PepG resulted in an impaired systolic contractility and reduced serum S1P. Administration of the immunomodulator FTY720 increased serum S1P, improved impaired systolic contractility and activated the phosphoinositide 3-kinase (PI3K)-pathway in the heart. Cardioprotective effects of FTY720 were abolished following administration of a S1P receptor 2 (S1P2) antagonist or a PI3K inhibitor. Sphingosine kinase-2 deficient mice had higher endogenous S1P levels and the LPS/PepG-induced impaired systolic contractility was attenuated in comparison with wild-type mice. Cardioprotective effects of FTY720 were confirmed in polymicrobial sepsis. We show here for the first time that the impaired left ventricular systolic contractility in experimental sepsis is attenuated by FTY720. Mechanistically, our results indicate that activation of S1P2 by increased serum S1P and the subsequent activation of the PI3K-Akt survival pathway significantly contributes to the observed cardioprotective effect of FTY720. PMID:27277195

  2. Protective effect of theophylline on renal functions in experimental pneumoperitoneum model.

    PubMed

    Ozturk, Sefa Alperen; Ceylan, Cavit; Serel, Tekin Ahmet; Doluoglu, Omer Gokhan; Soyupek, Arap Sedat; Guzel, Ahmet; Özorak, Alper; Uz, Efkan; Savas, Hasan Basri; Baspinar, Sirin

    2015-07-01

    Our objective in this experimental study is to research the effect of the intra-abdominal pressure which rises following pneumoperitoneum and whether Theophylline has a possible protective activity on this situation. In our study, 24 Wistar Albino rats were used. Rats were divided into two groups. The first group was set for only pneumoperitoneum model. The second group was given 15 mg/kg of Theophylline intraperitoneally before setting pneumoperitoneum model. Then urea, creatinine, cystatin-C, tissue and serum total antioxidant capacity, total oxidant capacity and oxidative stress index in two groups were measured and compared with each other. Apoptosis and histopathological conditions in the renal tissues were examined. The differences between the groups were analyzed with the Mann-Whitney U test. Results were considered significant at p < 0.05. No statistically significant difference was determined between tissue and serum averages in two groups in terms of TAS, TOS and OSI values (p > 0.05). The mean value of urea were similar in pneumoperitoneum and pneumoperitoneum + theophylline groups (p = 0.12). The mean cystatin-C value was 2.2 ± 0.3 µg/mL in pneumoperitoneum, 1.74 ± 0.33 µg/mL in pneumoperitoneum + theophylline (p = 0.002). According to our study, lower cystatin-C levels in the group, where Theophylline was given, are suggestive of lower renal injury in this group. However, this opinion is interrogated as there is no difference in terms of tissue and serum TAS, TOS, OSI and urea values between the groups. PMID:25959022

  3. Elevation of serum sphingosine-1-phosphate attenuates impaired cardiac function in experimental sepsis.

    PubMed

    Coldewey, Sina M; Benetti, Elisa; Collino, Massimo; Pfeilschifter, Josef; Sponholz, Christoph; Bauer, Michael; Huwiler, Andrea; Thiemermann, Christoph

    2016-01-01

    Serum levels of the lipid mediator sphingosine-1-phosphate (S1P) are reduced in septic patients and are inversely associated with disease severity. We show that serum S1P is reduced in human sepsis and in murine models of sepsis. We then investigated whether pharmacological or genetic approaches that alter serum S1P may attenuate cardiac dysfunction and whether S1P signaling might serve as a novel theragnostic tool in sepsis. Mice were challenged with lipopolysaccharide and peptidoglycan (LPS/PepG). LPS/PepG resulted in an impaired systolic contractility and reduced serum S1P. Administration of the immunomodulator FTY720 increased serum S1P, improved impaired systolic contractility and activated the phosphoinositide 3-kinase (PI3K)-pathway in the heart. Cardioprotective effects of FTY720 were abolished following administration of a S1P receptor 2 (S1P2) antagonist or a PI3K inhibitor. Sphingosine kinase-2 deficient mice had higher endogenous S1P levels and the LPS/PepG-induced impaired systolic contractility was attenuated in comparison with wild-type mice. Cardioprotective effects of FTY720 were confirmed in polymicrobial sepsis. We show here for the first time that the impaired left ventricular systolic contractility in experimental sepsis is attenuated by FTY720. Mechanistically, our results indicate that activation of S1P2 by increased serum S1P and the subsequent activation of the PI3K-Akt survival pathway significantly contributes to the observed cardioprotective effect of FTY720. PMID:27277195

  4. Protective effect of theophylline on renal functions in experimental pneumoperitoneum model.

    PubMed

    Ozturk, Sefa Alperen; Ceylan, Cavit; Serel, Tekin Ahmet; Doluoglu, Omer Gokhan; Soyupek, Arap Sedat; Guzel, Ahmet; Özorak, Alper; Uz, Efkan; Savas, Hasan Basri; Baspinar, Sirin

    2015-07-01

    Our objective in this experimental study is to research the effect of the intra-abdominal pressure which rises following pneumoperitoneum and whether Theophylline has a possible protective activity on this situation. In our study, 24 Wistar Albino rats were used. Rats were divided into two groups. The first group was set for only pneumoperitoneum model. The second group was given 15 mg/kg of Theophylline intraperitoneally before setting pneumoperitoneum model. Then urea, creatinine, cystatin-C, tissue and serum total antioxidant capacity, total oxidant capacity and oxidative stress index in two groups were measured and compared with each other. Apoptosis and histopathological conditions in the renal tissues were examined. The differences between the groups were analyzed with the Mann-Whitney U test. Results were considered significant at p < 0.05. No statistically significant difference was determined between tissue and serum averages in two groups in terms of TAS, TOS and OSI values (p > 0.05). The mean value of urea were similar in pneumoperitoneum and pneumoperitoneum + theophylline groups (p = 0.12). The mean cystatin-C value was 2.2 ± 0.3 µg/mL in pneumoperitoneum, 1.74 ± 0.33 µg/mL in pneumoperitoneum + theophylline (p = 0.002). According to our study, lower cystatin-C levels in the group, where Theophylline was given, are suggestive of lower renal injury in this group. However, this opinion is interrogated as there is no difference in terms of tissue and serum TAS, TOS, OSI and urea values between the groups.

  5. Impact of Cardiopulmonary Bypass on Respiratory Mucociliary Function in an Experimental Porcine Model

    PubMed Central

    Sánchez-Véliz, Rodrigo; Carmona, Maria José; Otsuki, Denise Aya; Freitas, Claudia; Benício, Anderson; Negri, Elnara Marcia; Malbouisson, Luiz Marcelo

    2015-01-01

    Background The impact of cardiac surgery using cardiopulmonary bypass (CPB) on the respiratory mucociliary function is unknown. This study evaluated the effects of CPB and interruption of mechanical ventilation on the respiratory mucociliary system. Methods Twenty-two pigs were randomly assigned to the control (n = 10) or CPB group (n = 12). After the induction of anesthesia, a tracheostomy was performed, and tracheal tissue samples were excised (T0) from both groups. All animals underwent thoracotomy. In the CPB group, an aorto-bicaval CPB was installed and maintained for 90 minutes. During the CPB, mechanical ventilation was interrupted, and the tracheal tube was disconnected. A second tracheal tissue sample was obtained 180 minutes after the tracheostomy (T180). Mucus samples were collected from the trachea using a bronchoscope at T0, T90 and T180. Ciliary beat frequency (CBF) and in situ mucociliary transport (MCT) were studied in ex vivo tracheal epithelium. Mucus viscosity (MV) was assessed using a cone-plate viscometer. Qualitative tracheal histological analysis was performed at T180 tissue samples. Results CBF decreased in the CPB group (13.1 ± 1.9 Hz vs. 11.1 ± 2.1 Hz, p < 0.05) but not in the control group (13.1 ± 1 Hz vs. 13 ± 2.9 Hz). At T90, viscosity was increased in the CPB group compared to the control (p < 0.05). No significant differences were observed in in situ MCT. Tracheal histology in the CPB group showed areas of ciliated epithelium loss, submucosal edema and infiltration of inflammatory cells. Conclusion CPB acutely contributed to alterations in tracheal mucocilliary function. PMID:26288020

  6. Rigid and remodelled: cerebrovascular structure and function after experimental high-thoracic spinal cord transection.

    PubMed

    Phillips, A A; Matin, N; Frias, B; Zheng, M M Z; Jia, M; West, C; Dorrance, A M; Laher, I; Krassioukov, A V

    2016-03-15

    High-thoracic or cervical spinal cord injury (SCI) is associated with several critical clinical conditions related to impaired cerebrovascular health, including: 300-400% increased risk of stroke, cognitive decline and diminished cerebral blood flow regulation. The purpose of this study was to examine the influence of high-thoracic (T3 spinal segment) SCI on cerebrovascular structure and function, as well as molecular markers of profibrosis. Seven weeks after complete T3 spinal cord transection (T3-SCI, n = 15) or sham injury (Sham, n = 10), rats were sacrificed for either middle cerebral artery (MCA) structure and function assessments via ex vivo pressure myography, or immunohistochemical analyses. Myogenic tone was unchanged, but over a range of transmural pressures, inward remodelling occurred after T3-SCI with a 40% reduction in distensibility (both P < 0.05), and a 33% reduction in vasoconstrictive reactivity to 5-HT trending toward significance (P = 0.09). After T3-SCI, the MCA had more collagen I (42%), collagen III (24%), transforming growth factor β (47%) and angiotensin II receptor type 2 (132%), 27% less elastin as well as concurrent increased wall thickness and reduced lumen diameter (all P < 0.05). Sympathetic innervation (tyrosine hydroxylase-positive axon density) and endothelium-dependent dilatation (carbachol) of the MCA were not different between groups. This study demonstrates profibrosis and hypertrophic inward remodelling within the largest cerebral artery after high-thoracic SCI, leading to increased stiffness and possibly impaired reactivity. These deleterious adaptations would substantially undermine the capacity for regulation of cerebral blood flow and probably underlie several cerebrovascular clinical conditions in the SCI population.

  7. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    NASA Astrophysics Data System (ADS)

    De Troch, M.; Roelofs, M.; Riedel, B.; Grego, M.

    2013-02-01

    Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.

  8. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    NASA Astrophysics Data System (ADS)

    De Troch, M.; Roelofs, M.; Riedel, B.; Grego, M.

    2013-06-01

    Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.

  9. Experimental evidence for friction-enhancing integumentary modifications of chameleons and associated functional and evolutionary implications.

    PubMed

    Khannoon, Eraqi R; Endlein, Thomas; Russell, Anthony P; Autumn, Kellar

    2014-01-22

    The striking morphological convergence of hair-like integumentary derivatives of lizards and arthropods (spiders and insects) demonstrates the importance of such features for enhancing purchase on the locomotor substrate. These pilose structures are responsible for the unique tractive abilities of these groups of animals, enabling them to move with seeming ease on overhanging and inverted surfaces, and to traverse inclined smooth substrates. Three groups of lizards are well known for bearing adhesion-promoting setae on their digits: geckos, anoles and skinks. Similar features are also found on the ventral subdigital and distal caudal skin of chameleons. These have only recently been described in any detail, and structurally and functionally are much less well understood than are the setae of geckos and anoles. The seta-like structures of chameleons are not branched (a characteristic of many geckos), nor do they terminate in spatulate tips (which is characteristic of geckos, anoles and skinks). They are densely packed and have attenuated blunt, globose tips or broad, blade-like shafts that are flattened for much of their length. Using a force transducer, we tested the hypothesis that these structures enhance friction and demonstrate that the pilose skin has a greater frictional coefficient than does the smooth skin of these animals. Our results are consistent with friction being generated as a result of side contact of the integumentary filaments. We discuss the evolutionary and functional implications of these seta-like structures in comparison with those typical of other lizard groups and with the properties of seta-mimicking synthetic structures.

  10. Living skin substitutes: survival and function of fibroblasts seeded in a dermal substitute in experimental wounds.

    PubMed

    Lamme, E N; van Leeuwen, R T; Jonker, A; van Marle, J; Middelkoop, E

    1998-12-01

    The healing of full-thickness skin defects requires extensive synthesis and remodeling of dermal and epidermal components. Fibroblasts play an important role in this process and are being incorporated in the latest generation of artificial dermal substitutes. We studied the fate of fibroblasts seeded in our artificial elastin/collagen dermal substitute and the influence of the seeded fibroblasts on cell migration and dermal substitute degradation after transplantation to experimental full-thickness wounds in pigs. Wounds were treated with either dermal substitutes seeded with autologous fibroblasts or acellular substitutes. Seeded fibroblasts, labeled with a PKH-26 fluorescent cell marker, were detected in the wounds with fluorescence microscopy and quantitated with flow cytofluorometric analysis of single-cell suspensions of wound tissue. The cellular infiltrate was characterized for the presence of mesenchymal cells (vimentin), monocytes/macrophages, and vascular cells. Dermal substitute degradation was quantitated by image analysis of wound sections stained with Herovici's staining. In the wounds treated with the seeded dermal substitute, fluorescent PKH-26-labeled cells were detectable up to 6 d and were positive for vimentin but not for the macrophage antibody. After 5 d, flow cytofluorometry showed the presence of 3.1 (+/-0.9) x 10(6) (mean +/- SD, n = 7) PKH-26-positive cells in these wounds, whereas initially only 1 x 10(6) fluorescent fibroblasts had been seeded. In total, the percentage of mesenchymal cells minus the macrophages was similar after 5 d between wounds treated with the seeded and the acellular substitutes. In the wounds treated with the seeded substitute, however, 19.5% of the mesenchymal cells were of seeded origin. Furthermore, the rate of substitute degradation in the seeded wounds was significantly lower at 2-4 wk after wounding than in wounds treated with the acellular substitute. Vascular in-growth and the number of infiltrated

  11. A new functional approach to the surgical management of Pierre Robin syndrome: experimental and clinical report.

    PubMed

    Lapidot, A; Rezvani, F; Terrefe, D; Ben-Hur, N

    1976-07-01

    A functional and simple surgical method for treating the respiratory distress of the neonate affected by Pierre Robin syndrome is described. The base of the tongue is placed in an anterior position via a buried wire suture tied around the body of the hyoid. The method proposed in this paper fulfills the following: 1. It is physiologic since the infant is able to suckle and maintain its nutrition by preserving the function of the mobile portion of the tongue for deglutition. 2. Maintenance of the "pushing" action of the tongue stimulates growth of the mandible. 3. The anchoring wire is not exposed in the oral cavity and the risk of tissue breakdown and infection is eliminated. 4. This technique utilizes the stronger fibrous portion of the mid-tongue rather than muscle which "gives" more readily under pressure. 5. The shortest distance from the base of the tongue to the mid-hyoid provides the best mechanical advantage. 6. The suture, if need be, may be tightened at subsequent periods of time. Under Ketamin (Ketalan) anesthesia the tip of the tongue was held in the forward position. An 18 gauge stainless steel wire was inserted via a large curved needle through the midline of the posterior-most portion at the base of the tongue. The needle was directed anteriorly and inferiorly to emerge below the mid point of the inferior border of the hyoid bone. The opposite end of the wire was then tunneled submucosally to the anterior portion of the base of the tongue at foramen caecum, and directed inferiorly to emerge above the superior border of the mid-portion of the hyoid bone. Through a small skin incision opposite the body of the hyoid bone, both free ends of the wire were tied under tension around the body of the hyoid while pulling the base of the tongue forward. The skin incision was closed with a single nylon suture. A prosthetic obturator was used to close the cleft palate. The outcome was satisfactory with no morbidity.

  12. Central Functions of the Lumenal and Peripheral Thylakoid Proteome of Arabidopsis Determined by Experimentation and Genome-Wide Prediction

    PubMed Central

    Peltier, Jean-Benoît; Emanuelsson, Olof; Kalume, Dário E.; Ytterberg, Jimmy; Friso, Giulia; Rudella, Andrea; Liberles, David A.; Söderberg, Linda; Roepstorff, Peter; von Heijne, Gunnar; van Wijk, Klaas J.

    2002-01-01

    Experimental proteome analysis was combined with a genome-wide prediction screen to characterize the protein content of the thylakoid lumen of Arabidopsis chloroplasts. Soluble thylakoid proteins were separated by two-dimensional electrophoresis and identified by mass spectrometry. The identities of 81 proteins were established, and N termini were sequenced to validate localization prediction. Gene annotation of the identified proteins was corrected by experimental data, and an interesting case of alternative splicing was discovered. Expression of a surprising number of paralogs was detected. Expression of five isomerases of different classes suggests strong (un)folding activity in the thylakoid lumen. These isomerases possibly are connected to a network of peripheral and lumenal proteins involved in antioxidative response, including peroxiredoxins, m-type thioredoxins, and a lumenal ascorbate peroxidase. Characteristics of the experimentally identified lumenal proteins and their orthologs were used for a genome-wide prediction of the lumenal proteome. Lumenal proteins with a typical twin-arginine translocation motif were predicted with good accuracy and sensitivity and included additional isomerases and proteases. Thus, prime functions of the lumenal proteome include assistance in the folding and proteolysis of thylakoid proteins as well as protection against oxidative stress. Many of the predicted lumenal proteins must be present at concentrations at least 10,000-fold lower than proteins of the photosynthetic apparatus. PMID:11826309

  13. Exercise prevents the effects of experimental arthritis on the metabolism and function of immune cells.

    PubMed

    Navarro, Francisco; Bacurau, Aline V N; Almeida, Sandro S; Barros, Carlos C; Moraes, Milton R; Pesquero, Jorge L; Ribeiro, Sandra M L; Araújo, Ronaldo C; Costa Rosa, Luis F B P; Bacurau, Reury F P

    2010-06-01

    Active lymphocytes (LY) and macrophages (MPhi) are involved in the pathophysiology of rheumatoid arthritis (RA). Due to its anti-inflammatory effect, physical exercise may be beneficial in RA by acting on the immune system (IS). Thus, female Wistar rats with type II collagen-induced arthritis (CIA) were submitted to swimming training (6 weeks, 5 days/week, 60 min/day) and some biochemical and immune parameters, such as the metabolism of glucose and glutamine and function of LY and MPhi, were evaluated. In addition, plasma levels of some hormones and of interleukin-2 (IL-2) were also determined. Results demonstrate that CIA increased lymphocyte proliferation (1.9- and 1.7-fold, respectively, in response to concanavalin A (ConA) and lipopolysaccharide (LPS)), as well as macrophage H(2)O(2) production (1.6-fold), in comparison to control. Exercise training prevented the activation of immune cells, induced by CIA, and established a pattern of substrate utilization similar to that described as normal for these cells. Exercise also promoted an elevation of plasma levels of corticosterone (22.2%), progesterone (1.7-fold) and IL-2 (2.6-fold). Our data suggest that chronic exercise is able to counterbalance the effects of CIA on cells of the IS, reinforcing the proposal that the benefits of exercise may not be restricted to aerobic capacity and/or strength improvement. PMID:20517889

  14. Experimental and density functional theory study of Raman and SERS spectra of 5-amino-2-mercaptobenzimidazole

    NASA Astrophysics Data System (ADS)

    Chen, Yufeng; Yang, Jin; Li, Zonglong; Li, Ran; Ruan, Weidong; Zhuang, Zhiping; Zhao, Bing

    2016-01-01

    Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS) and density functional theory (DFT) simulations were employed to study 5-amino-2-mercaptobenzimidazole (5-A-2MBI) molecules. Ag colloids were used as SERS substrates which were prepared by using hydroxylamine hydrochloride as reducing agent. Raman vibration modes and SERS characteristic peaks of 5-A-2MBI were assigned with the aid of DFT calculations. The molecular electrostatic potential (MEP) of 5-A-2MBI was used to discuss the possible adsorption behavior of 5-A-2MBI on Ag colloids. The spectral analysis showed that 5-A-2MBI molecules were slightly titled via the sulfur atoms adhering to the surfaces of Ag substrates. The obtained SERS spectral intensity decreased when lowering the 5-A-2MBI concentrations. A final detection limit on the concentration of 5 × 10- 7 mol · L- 1 was gained. SERS proved to be a simple, fast and reliable method for the detection and characterization of 5-A-2MBI molecules.

  15. Experimental Modification of Rat Pituitary Growth Hormone Cell Function During and After Spaceflight

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.; Salada, T.; Nye, P.; Grossman, E. J.; Lane, P. K.; Grindeland, R. E.

    1996-01-01

    Space-flown rats show a number of flight-induced changes in the structure and function of pituitary Growth Hormone (GH) cells after in vitro postflight testing. To evaluate the possible effects of microgravity on GH cells themselves, freshly dispersed rat anterior pituitary gland cells were seeded into vials containing serum +/- 1 micron HydroCortisone (HC) before flight. Five different cell preparations were used: the entire mixed-cell population of various hormone-producing cell types, cells of density less than 1.071 g/sq cm (band 1), cells of density greater than 1.071 g/sq cm (band 2), and cells prepared from either the dorsal or ventral part of the gland. Relative to ground control samples, bioactive GH released from dense cells during flight was reduced in HC-free medium but was increased in HC-containing medium. Band I and mixed cells usually showed opposite HC-dependent responses. Release of bioactive GH from ventral flight cells was lower; postflight responses to GH-releasing hormone challenge were reduced, and the cytoplasmic area occupied by GH in the dense cells was greater. Collectively, the data show that the chemistry and cellular makeup of the culture system modifies the response of GH cells to microgravity. As such, these cells offer a system to identify gravisensing mechanisms in secretory cells in future microgravity research.

  16. Functional MMP-10 is required for efficient tissue repair after experimental hind limb ischemia.

    PubMed

    Gomez-Rodriguez, Violeta; Orbe, Josune; Martinez-Aguilar, Esther; Rodriguez, Jose A; Fernandez-Alonso, Leopoldo; Serneels, Jens; Bobadilla, Miriam; Perez-Ruiz, Ana; Collantes, Maria; Mazzone, Massimiliano; Paramo, Jose A; Roncal, Carmen

    2015-03-01

    We studied the role of matrix metalloproteinase-10 (MMP-10) during skeletal muscle repair after ischemia using a model of femoral artery excision in wild-type (WT) and MMP-10 deficient (Mmp10(-/-)) mice. Functional changes were analyzed by small animal positron emission tomography and tissue morphology by immunohistochemistry. Gene expression and protein analysis were used to study the molecular mechanisms governed by MMP-10 in hypoxia. Early after ischemia, MMP-10 deficiency resulted in delayed tissue reperfusion (10%, P < 0.01) and in increased necrosis (2-fold, P < 0.01), neutrophil (4-fold, P < 0.01), and macrophage (1.5-fold, P < 0.01) infiltration. These differences at early time points resulted in delayed myotube regeneration in Mmp10(-/-) soleus at later stages (regenerating myofibers: 30 ± 9% WT vs. 68 ± 10% Mmp10(-/-), P < 0.01). The injection of MMP-10 into Mmp10(-/-) mice rescued the observed phenotype. A molecular analysis revealed higher levels of Cxcl1 mRNA (10-fold, P < 0.05) and protein (30%) in the ischemic Mmp10(-/-) muscle resulting from a lack of transcriptional inhibition by MMP-10. This was further confirmed using siRNA against MMP-10 in vivo. Our results demonstrate an important role of MMP-10 for proper muscle repair after ischemia, and suggest that chemokine regulation such as Cxcl1 by MMP-10 is involved in muscle regeneration. PMID:25414484

  17. Effects of thyroid function on the course of experimental chronic renal failure in rats.

    PubMed

    Sanai, Toru; Hirano, Tadashi; Nagata, Masaharu; Okuda, Seiya

    2005-01-01

    Thyroid hormone has been reported to affect renal function. To investigate the effects of thyroid hormone on the progression of renal deterioration, thyroid hormone (dried thyroid) and an antithyroid drug (thiamazole) were administered to adriamycin (ADR)-induced renal failure rats. The rats were divided into four groups, including 1) ADR-DT, given dried thyroid and thiamazole; 2) ADR-T, given thiamazole; 3) ADR; and 4) control. The survival rate at the end of the study (22 weeks) was 62.5% in ADR-DT group and 100% in ADR-T, ADR, and control groups, respectively. There was a significant difference in the body weight and pulse rate between ADR-DT and ADR-T or ADR groups, except for the pulse rate at week 6 (P<0.05). The creatinine clearance was greater in the ADR-T group than in the ADR or ADR-DT groups at week 22, and was significantly different between the ADR-T and the ADR-DT groups (P<0.05). The fractional kidney weight and tubular changes were significantly greater in the ADR-DT group than in the ADR-T or ADR groups (P<0.05). The interstitial volume was significantly greater in the ADR-DT group than in the ADR-T group (P<0.05). We therefore conclude that a dried thyroid has an aggravative effect in the tubular changes and relative interstitial volume induced by ADR.

  18. Experimental Determination of Contaminant Metal Mobility as a Function of Temperature, Time and Solution Chemistry

    SciTech Connect

    Carroll, S A; O'Day, P A

    2000-03-01

    During the FY96-FY99 funding cycle we examined the uptake of aqueous strontium onto goethite, kaolinite, and amorphous silica surfaces as a function of pH, total strontium, and temperature. Our overall goal was to produce a mechanistic sorption model that can be used in reaction-transport calculations to predict the mobility and attenuation of radioactive strontium ({sup 90}Sr)in the environment. Our approach was to combine structural information derived from EXAFS analysis together with macroscopic uptake data and surface complexation models to clarify the physical and chemical structure of sorbed complexes. We chose to study these solids because of the prevalence of clays and iron hydroxides in natural systems, and because silica colloids probably form beneath leaking tanks at Hanford as caustic waste is neutralized. We have published the spectroscopic work in two papers in the Journal of Colloid and Interface Science [1, 2], and will soon submit at third manuscript to Geochemical Transactions [3] combining the sorption and spectroscopic data with a mechanistic complexation model. Early in the study we learned that strontium sorption was independent of temperature (25 to 80 C). All subsequent work was conducted at room temperature.

  19. Effect of Additives on Green Sand Molding Properties using Design of Experiments and Taguchi's Quality Loss Function - An Experimental Study

    NASA Astrophysics Data System (ADS)

    Desai, Bhagyashree; Mokashi, Pavani; Anand, R. L.; Burli, S. B.; Khandal, S. V.

    2016-09-01

    The experimental study aims to underseek the effect of various additives on the green sand molding properties as a particular combination of additives could yield desired sand properties. The input parameters (factors) selected were water and powder (Fly ash, Coconut shell and Tamarind) in three levels. Experiments were planned using design of experiments (DOE). On the basis of plans, experiments were conducted to understand the behavior of sand mould properties such as compression strength, shear strength, permeability number with various additives. From the experimental results it could be concluded that the factors have significant effect on the sand properties as P-value found to be less than 0.05 for all the cases studied. The optimization based on quality loss function was also performed. The study revealed that the quality loss associated with the tamarind powder was lesser compared to other additives selected for the study. The optimization based on quality loss function and the parametric analysis using ANOVA suggested that the tamarind powder of 8 gm per Kg of molding sand and moisture content of 7% yield better properties to obtain sound castings.

  20. An experimental and density functional study on conformational and spectroscopic analysis of 5-methoxyindole-2-carboxylic acid.

    PubMed

    Cinar, Mehmet; Karabacak, Mehmet; Asiri, Abdullah M

    2015-02-25

    In this article, a brief conformational and spectroscopic characterization of 5-methoxyindole-2-carboxylic acid (5-MeOICA) via experimental techniques and applications of quantum chemical methods is presented. The conformational analysis of the studied molecule was determined theoretically using density functional computations for ground state, and compared with previously reported experimental findings. The vibrational transitions were examined by measured FT-IR and FT-Raman spectroscopic data, and also results obtained from B3LYP and CAM-B3LYP functionals in combination with 6-311++G(d,p) basis set. The recorded proton and carbon NMR spectra in DMSO solution were analyzed to obtain the exact conformation. Due to intermolecular hydrogen bondings, NMR calculations were performed for the dimeric form of 5-MeOICA and so chemical shifts of those protons were predicted more accurately. Finally, electronic properties of steady compound were identified by a comparative study of UV absorption spectra in ethanol and water solution and TD-DFT calculations. PMID:25255480

  1. Different Assembly Processes Drive Shifts in Species and Functional Composition in Experimental Grasslands Varying in Sown Diversity and Community History

    PubMed Central

    Roscher, Christiane; Schumacher, Jens; Gerighausen, Uta; Schmid, Bernhard

    2014-01-01

    Background The prevalence of different biotic processes (limiting similarity, weaker competitor exclusion) and historical contingency due to priority effects are in the focus of ongoing discussions about community assembly and non-random functional trait distributions. Methodology/Principal Findings We experimentally manipulated assembly history in a grassland biodiversity experiment (Jena Experiment) by applying two factorially crossed split-plot treatments to all communities: (i) duration of weeding (never weeded since sowing or cessation of weeding after 3 or 6 years); (ii) seed addition (control vs. seed addition 4 years after sowing). Spontaneous colonization of new species in the control treatment without seed addition increased realized species richness and functional richness (FRic), indicating continuously denser packing of niches. Seed addition resulted in forced colonization and increased realized species richness, FRic, functional evenness (FEve) and functional divergence (FDiv), i.e. higher abundances of species with extreme trait values. Furthermore, the colonization of new species led to a decline in FEve through time, suggesting that weaker competitors were reduced in abundance or excluded. Communities with higher initial species richness or with longer time since cessation of weeding were more restricted in the entry of new species and showed smaller increases in FRic after seed addition than other communities. The two assembly-history treatments caused a divergence of species compositions within communities originally established with the same species. Communities originally established with different species converged in species richness and functional trait composition over time, but remained more distinct in species composition. Conclusions/Significance Contrasting biotic processes (limiting similarity, weaker competitor exclusion) increase functional convergence between communities initially established with different species. Historical

  2. An experimental study of permeability development as a function of crystal-free melt viscosity

    NASA Astrophysics Data System (ADS)

    Lindoo, A.; Larsen, J. F.; Cashman, K. V.; Dunn, A. L.; Neill, O. K.

    2016-02-01

    Permeability development in magmas controls gas escape and, as a consequence, modulates eruptive activity. To date, there are few experimental controls on bubble growth and permeability development, particularly in low viscosity melts. To address this knowledge gap, we have run controlled decompression experiments on crystal-free rhyolite (76 wt.% SiO2), rhyodacite (70 wt.% SiO2), K-phonolite (55 wt.% SiO2) and basaltic andesite (54 wt.% SiO2) melts. This suite of experiments allows us to examine controls on the critical porosity at which vesiculating melts become permeable. As starting materials we used both fine powders and solid slabs of pumice, obsidian and annealed starting materials with viscosities of ˜102 to ˜106 Pas. We saturated the experiments with water at 900° (rhyolite, rhyodacite, and phonolite) and 1025 °C (basaltic andesite) at 150 MPa for 2-72 hrs and decompressed samples isothermally to final pressures of 125 to 10 MPa at rates of 0.25-4.11 MPa/s. Sample porosity was calculated from reflected light images of polished charges and permeability was measured using a bench-top gas permeameter and application of the Forchheimer equation to estimate both viscous (k1) and inertial (k2) permeabilities. Degassing conditions were assessed by measuring dissolved water contents using micro-Fourier-Transform Infrared (μ-FTIR) techniques. All experiment charges are impermeable below a critical porosity (ϕc) that varies among melt compositions. For experiments decompressed at 0.25 MPa/s, we find the percolation threshold for rhyolite is 68.3 ± 2.2 vol.%; for rhyodacite is 77.3 ± 3.8 vol.%; and for K-phonolite is 75.6 ± 1.9 vol.%. Rhyolite decompressed at 3-4 MPa/s has a percolation threshold of 74 ± 1.8 vol.%. These results are similar to previous experiments on silicic melts and to high permeability thresholds inferred for silicic pumice. All basaltic andesite melts decompressed at 0.25 MPa/s, in contrast, have permeabilities below the detection limit

  3. Using experimental manipulation to assess the roles of leaf litter in the functioning of forest ecosystems.

    PubMed

    Sayer, Emma J

    2006-02-01

    The widespread use of forest litter as animal bedding in central Europe for many centuries gave rise to the first litter manipulation studies, and their results demonstrated that litter and its decomposition are a vital part of ecosystem function. Litter plays two major roles in forest ecosystems: firstly, litterfall is an inherent part of nutrient and carbon cycling, and secondly, litter forms a protective layer on the soil surface that also regulates microclimatic conditions. By reviewing 152 years of litter manipulation experiments, I show that the effects of manipulating litter stem from changes in one, or both, of these two functions, and interactions between the variables influenced by the accumulation of litter can result in feedback mechanisms that may intensify treatment effects or mask responses, making the interpretation of results difficult.Long-term litter removal increased soil bulk density, overland flow, erosion, and temperature fluctuations and upset the soil water balance, causing lower soil water content during dry periods. Soil pH increased or decreased in response to manipulation treatments depending on forest type and initial soil pH, but it is unclear why there was no uniform response. Long-term litter harvesting severely depleted the forests of nutrients. Decreases in the concentrations of available P, Ca, Mg, and K in the soil occurred after only three to five years. The decline in soil N occurred over longer periods of time, and the relative loss was greater in soils with high initial nitrogen concentration. Tree growth declined with long-term litter removal, probably due to lower nutrient availability. Litter manipulation also added or removed large amounts of carbon thereby affecting microbial communities and altering soil respiration rates. Litter manipulation experiments have shown that litter cover acts as a physical barrier to the shoot emergence of small-seeded species; further, the microclimate maintained by the litter layer may be

  4. Experimental Study of the Convergence of Two-Point Cross-Correlation Toward the Green's Function

    NASA Astrophysics Data System (ADS)

    Gouedard, P.; Roux, P.; Campillo, M.; Verdel, A.; Campman, X.

    2007-12-01

    It has been shown theoretically by several authors that cross-correlation of the seismic motion recorded at two points could yield the Green's Function (GF) between these points. Convergence of cross-correlations toward the GF depends on sources positions and/or the nature of the wavefield. Direct waves from an even distribution of sources can be used to retrieve the GF. On the other hand, in an inhomogeneous medium, recording the diffuse field (coda) is theoretically sufficient to retrieve the GF whatever the sources distribution is. Since none of these two conditions (even distribution of sources or a perfectly diffuse field) is satisfied in practice, the question of convergence toward the GF has to be investigated with real data. A 3D exploration survey with sources and receivers on a dense grid offers such an opportunity. We used a high- resolution survey recorded by Petroleum Development Oman in North Oman. The data have been obtained in a 1x1~km area covered with 1600 geophones located on a 25x25~m-cell grid. Records are 4-seconds long. A unique feature of this survey is that vibrators (working in the [8-120~Hz] frequency band), were located on a similar grid shifted with respect to the receiver grid by half a cell (12.5~m) in both directions. This allows us to compare estimated GF's with measured direct waves (GF's) between the geophones. The shallow subsurface is highly heterogeneous and records include seismic coda. From this dataset, we selected two receiver locations (Ra and Rb) distant from d=158~m. We used both different sets of source locations and time windows to compute the cross-correlation between these two receivers. Then we compared the derivatives of correlation functions with the actual GF measured in Rb (resp.~Ra) for a source close to Ra (resp.~Rb). By doing so, we show the actual influence of source locations and scattering (governed by the records' selected time window) on the Signal-to-Noise Ratio (SNR) of the reconstructed GF. When using

  5. Functioning of a Shallow-Water Sediment System during Experimental Warming and Nutrient Enrichment

    PubMed Central

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment–water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID

  6. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment.

    PubMed

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment-water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment.

  7. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment.

    PubMed

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment-water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID:23240032

  8. Stylus: A System for Evolutionary Experimentation Based on a Protein/Proteome Model with Non-Arbitrary Functional Constraints

    PubMed Central

    Axe, Douglas D.; Dixon, Brendan W.; Lu, Philip

    2008-01-01

    The study of protein evolution is complicated by the vast size of protein sequence space, the huge number of possible protein folds, and the extraordinary complexity of the causal relationships between protein sequence, structure, and function. Much simpler model constructs may therefore provide an attractive complement to experimental studies in this area. Lattice models, which have long been useful in studies of protein folding, have found increasing use here. However, while these models incorporate actual sequences and structures (albeit non-biological ones), they incorporate no actual functions—relying instead on largely arbitrary structural criteria as a proxy for function. In view of the central importance of function to evolution, and the impossibility of incorporating real functional constraints without real function, it is important that protein-like models be developed around real structure–function relationships. Here we describe such a model and introduce open-source software that implements it. The model is based on the structure–function relationship in written language, where structures are two-dimensional ink paths and functions are the meanings that result when these paths form legible characters. To capture something like the hierarchical complexity of protein structure, we use the traditional characters of Chinese origin. Twenty coplanar vectors, encoded by base triplets, act like amino acids in building the character forms. This vector-world model captures many aspects of real proteins, including life-size sequences, a life-size structural repertoire, a realistic genetic code, secondary, tertiary, and quaternary structure, structural domains and motifs, operon-like genetic structures, and layered functional complexity up to a level resembling bacterial genomes and proteomes. Stylus is a full-featured implementation of the vector world for Unix systems. To demonstrate the utility of Stylus, we generated a sample set of homologous vector

  9. Prenatal Intestinal Obstruction Affects the Myenteric Plexus and Causes Functional Bowel Impairment in Fetal Rat Experimental Model of Intestinal Atresia

    PubMed Central

    Khen-Dunlop, Naziha; Sarnacki, Sabine; Victor, Anais; Grosos, Celine; Menard, Sandrine; Soret, Rodolphe; Goudin, Nicolas; Pousset, Maud; Sauvat, Frederique; Revillon, Yann; Cerf-Bensussan, Nadine; Neunlist, Michel

    2013-01-01

    Background Intestinal atresia is a rare congenital disorder with an incidence of 3/10 000 birth. About one-third of patients have severe intestinal dysfunction after surgical repair. We examined whether prenatal gastrointestinal obstruction might effect on the myenteric plexus and account for subsequent functional disorders. Methodology/Principal Findings We studied a rat model of surgically induced antenatal atresia, comparing intestinal samples from both sides of the obstruction and with healthy rat pups controls. Whole-mount preparations of the myenteric plexus were stained for choline acetyltransferase (ChAT) and nitric oxide synthase (nNOS). Quantitative reverse transcription PCR was used to analyze mRNAs for inflammatory markers. Functional motility and permeability analyses were performed in vitro. Phenotypic studies were also performed in 8 newborns with intestinal atresia. In the experimental model, the proportion of nNOS-immunoreactive neurons was similar in proximal and distal segments (6.7±4.6% vs 5.6±4.2%, p = 0.25), but proximal segments contained a higher proportion of ChAT-immunoreactive neurons (13.2±6.2% vs 7.5±4.3%, p = 0.005). Phenotypic changes were associated with a 100-fold lower concentration-dependent contractile response to carbachol and a 1.6-fold higher EFS-induced contractile response in proximal compared to distal segments. Transcellular (p = 0.002) but not paracellular permeability was increased. Comparison with controls showed that modifications involved not only proximal but also distal segments. Phenotypic studies in human atresia confirmed the changes in ChAT expression. Conclusion Experimental atresia in fetal rat induces differential myenteric plexus phenotypical as well as functional changes (motility and permeability) between the two sides of the obstruction. Delineating these changes might help to identify markers predictive of motility dysfunction and to define guidelines for post-surgical care. PMID:23667464

  10. A comparative cost analysis of polytrauma and neurosurgery Intensive Care Units at an apex trauma care facility in India

    PubMed Central

    Kumar, Parmeshwar; Jithesh, V.; Gupta, Shakti Kumar

    2016-01-01

    Context: Although Intensive Care Units (ICUs) only account for 10% of the hospital beds, they consume nearly 22% of the hospital resources. Few definitive costing studies have been conducted in Indian settings that would help determine appropriate resource allocation. Aim: The aim of this study was to evaluate and compare the cost of intensive care delivery between multispecialty and neurosurgery ICUs at an apex trauma care facility in India. Materials and Methods: The study was conducted in a polytrauma and neurosurgery ICU at a 203-bedded Level IV trauma care facility in New Delhi, India, from May 1, 2012 to June 30, 2012. The study was cross-sectional, retrospective, and record-based. Traditional costing was used to arrive at the cost for both direct and indirect cost estimates. The cost centers included in the study were building cost, equipment cost, human resources, materials and supplies, clinical and nonclinical support services, engineering maintenance cost, and biomedical waste management. Statistical Analysis: Statistical analysis was performed by Fisher's two tailed t-test. Results: Total cost/bed/day for the multispecialty ICU was Rs. 14,976.9/- and for the neurosurgery ICU, it was Rs. 14,306.7/-, workforce constituting nearly half of the expenditure in both ICUs. The cost center wise and overall difference in the cost among the ICUs were statistically significant. Conclusions: Quantification of expenditure in running an ICU in a trauma center would assist health-care decision makers in better allocation of resources. Although multispecialty ICUs are more cost-effective, other factors will also play a role in defining the kind of ICU that needs to be designed. PMID:27555693

  11. Experimental and theoretical studies on compositions, structures, and IR and NMR spectra of functionalized protic ionic liquids.

    PubMed

    Cui, Yingna; Yin, Jingmei; Li, Changping; Li, Shenmin; Wang, Ailing; Yang, Guang; Jia, Yingping

    2016-07-20

    The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and (1)H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. (1)H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and (1)H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs. PMID:27385035

  12. Genetic linkage of soil carbon pools and microbial functions in subtropical freshwater wetlands in response to experimental warming.

    PubMed

    Wang, Hang; He, Zhili; Lu, Zhenmei; Zhou, Jizhong; Van Nostrand, Joy D; Xu, Xinhua; Zhang, Zhijian

    2012-11-01

    Rising climate temperatures in the future are predicted to accelerate the microbial decomposition of soil organic matter. A field microcosm experiment was carried out to examine the impact of soil warming in freshwater wetlands on different organic carbon (C) pools and associated microbial functional responses. GeoChip 4.0, a functional gene microarray, was used to determine microbial gene diversity and functional potential for C degradation. Experimental warming significantly increased soil pore water dissolved organic C and phosphorus (P) concentrations, leading to a higher potential for C emission and P export. Such losses of total organic C stored in soil could be traced back to the decomposition of recalcitrant organic C. Warming preferentially stimulated genes for degrading recalcitrant C over labile C. This was especially true for genes encoding cellobiase and mnp for cellulose and lignin degradation, respectively. We confirmed this with warming-enhanced polyphenol oxidase and peroxidase activities for recalcitrant C acquisition and greater increases in recalcitrant C use efficiency than in labile C use efficiency (average percentage increases of 48% versus 28%, respectively). The relative abundance of lignin-degrading genes increased by 15% under warming; meanwhile, soil fungi, as the primary decomposers of lignin, were greater in abundance by 27%. This work suggests that future warming may enhance the potential for accelerated fungal decomposition of lignin-like compounds, leading to greater microbially mediated C losses than previously estimated in freshwater wetlands.

  13. Theoretical and Experimental Investigation of Random Gust Loads Part I : Aerodynamic Transfer Function of a Simple Wing Configuration in Incompressible Flow

    NASA Technical Reports Server (NTRS)

    Hakkinen, Raimo J; Richardson, A S , Jr

    1957-01-01

    Sinusoidally oscillating downwash and lift produced on a simple rigid airfoil were measured and compared with calculated values. Statistically stationary random downwash and the corresponding lift on a simple rigid airfoil were also measured and the transfer functions between their power spectra determined. The random experimental values are compared with theoretically approximated values. Limitations of the experimental technique and the need for more extensive experimental data are discussed.

  14. Impressions of neurology and neurosurgery in the People's Republic of China.

    PubMed

    Tower, D B; Feindel, W

    1980-05-01

    During July, 1979, the authors visited the neurological and neurosurgical services of eight major hospitals and associated medical schools in Peking, Tientsin, and Shanghai, and viewed many of their teaching and research facilities. From these visits and our discussions with the staffs of these units, we came away with the impressions reported here. In the People's Republic of China today there are more than 2,000 neurologists and 1,300 neurosurgeons. At present there are two major clinical centers: the Peking Institute of Neurosurgery, directed by Prof Wang Chung-Cheng and located in the Xuan Wu Hospital affiliated with the Peking First Medical College; and the Shanghai Institute of Neurology, directed by Prof Chang Yuan-Cheng and located in the Hua San Hospital affiliated with the Shanghai First Medical College. In every hospital, patient loads are formidable (e.g., several thousand outpatients weekly), but the variety of clinical problems does not differ from those seen elsewhere in the world. The most common problems are head injuries, brain tumors, cerebrovascular disorders, infections, and epilepsy. Each of the centers is heavily engaged in undergraduate and postgraduate training, and research has been resumed after the major disruptions of the 1966-76 "Cultural Revolution." Research continues on acupuncture, but present emphasis is directed toward pain mechanisms, notably at the Shanghai Institute of Physiology, directed by Prof Feng De-Pei. We were most impressed by this, the principal neurophysiology and neuroscience research center in the country. Clearly, the People's Republic of China has a wealth of clinical material and many competent neurologists and neurosurgeons with stimulating research ideas-characteristics which offer real potentials for collaborative research.

  15. Towards the development of a spring-based continuum robot for neurosurgery

    NASA Astrophysics Data System (ADS)

    Kim, Yeongjin; Cheng, Shing Shin; Desai, Jaydev P.

    2015-03-01

    Brain tumor is usually life threatening due to the uncontrolled growth of abnormal cells native to the brain or the spread of tumor cells from outside the central nervous system to the brain. The risks involved in carrying out surgery within such a complex organ can cause severe anxiety in cancer patients. However, neurosurgery, which remains one of the more effective ways of treating brain tumors focused in a confined volume, can have a tremendously increased success rate if the appropriate imaging modality is used for complete tumor removal. Magnetic resonance imaging (MRI) provides excellent soft-tissue contrast and is the imaging modality of choice for brain tumor imaging. MRI combined with continuum soft robotics has immense potential to be the revolutionary treatment technique in the field of brain cancer. It eliminates the concern of hand tremor and guarantees a more precise procedure. One of the prototypes of Minimally Invasive Neurosurgical Intracranial Robot (MINIR-II), which can be classified as a continuum soft robot, consists of a snake-like body made of three segments of rapid prototyped plastic springs. It provides improved dexterity with higher degrees of freedom and independent joint control. It is MRI-compatible, allowing surgeons to track and determine the real-time location of the robot relative to the brain tumor target. The robot was manufactured in a single piece using rapid prototyping technology at a low cost, allowing it to disposable after each use. MINIR-II has two DOFs at each segment with both joints controlled by two pairs of MRI-compatible SMA spring actuators. Preliminary motion tests have been carried out using vision-tracking method and the robot was able to move to different positions based on user commands.

  16. Laser range scanning for image-guided neurosurgery: investigation of image-to-physical space registrations.

    PubMed

    Cao, Aize; Thompson, R C; Dumpuri, P; Dawant, B M; Galloway, R L; Ding, S; Miga, M I

    2008-04-01

    In this article a comprehensive set of registration methods is utilized to provide image-to-physical space registration for image-guided neurosurgery in a clinical study. Central to all methods is the use of textured point clouds as provided by laser range scanning technology. The objective is to perform a systematic comparison of registration methods that include both extracranial (skin marker point-based registration (PBR), and face-based surface registration) and intracranial methods (feature PBR, cortical vessel-contour registration, a combined geometry/intensity surface registration method, and a constrained form of that method to improve robustness). The platform facilitates the selection of discrete soft-tissue landmarks that appear on the patient's intraoperative cortical surface and the preoperative gadolinium-enhanced magnetic resonance (MR) image volume, i.e., true corresponding novel targets. In an 11 patient study, data were taken to allow statistical comparison among registration methods within the context of registration error. The results indicate that intraoperative face-based surface registration is statistically equivalent to traditional skin marker registration. The four intracranial registration methods were investigated and the results demonstrated a target registration error of 1.6 +/- 0.5 mm, 1.7 +/- 0.5 mm, 3.9 +/- 3.4 mm, and 2.0 +/- 0.9 mm, for feature PBR, cortical vessel-contour registration, unconstrained geometric/intensity registration, and constrained geometric/intensity registration, respectively. When analyzing the results on a per case basis, the constrained geometric/intensity registration performed best, followed by feature PBR, and finally cortical vessel-contour registration. Interestingly, the best target registration errors are similar to targeting errors reported using bone-implanted markers within the context of rigid targets. The experience in this study as with others is that brain shift can compromise extracranial

  17. The DTI Challenge: Towards Standardized Evaluation of Diffusion Tensor Imaging Tractography for Neurosurgery

    PubMed Central

    Pujol, Sonia; Wells, William; Pierpaoli, Carlo; Brun, Caroline; Gee, James; Cheng, Guang; Vemuri, Baba; Commowick, Olivier; Prima, Sylvain; Stamm, Aymeric; Goubran, Maged; Khan, Ali; Peters, Terry; Neher, Peter; Maier-Hein, Klaus H.; Shi, Yundi; Tristan-Vega, Antonio; Veni, Gopalkrishna; Whitaker, Ross; Styner, Martin; Westin, Carl-Fredrik; Gouttard, Sylvain; Norton, Isaiah; Chauvin, Laurent; Mamata, Hatsuho; Gerig, Guido; Nabavi, Arya; Golby, Alexandra; Kikinis, Ron

    2015-01-01

    Background and Purpose Diffusion tensor imaging tractography reconstruction of white matter pathways can help guide brain tumor resection. However, DTI tracts are complex mathematical objects and the validity of tractography-derived information in clinical settings has yet to be fully established. To address this issue, we initiated the DTI Challenge, an international working group of clinicians and scientists whose goal was to provide standardized evaluation of tractography methods for neurosurgery. The purpose of this empirical study was to evaluate different tractography techniques in the first DTI Challenge workshop. Methods Eight international teams from leading institutions reconstructed the pyramidal tract in four neurosurgical cases presenting with a glioma near the motor cortex. Tractography methods included deterministic, probabilistic, filtered, and global approaches. Standardized evaluation of the tracts consisted in the qualitative review of the pyramidal pathways by a panel of neurosurgeons and DTI experts and the quantitative evaluation of the degree of agreement among methods. Results The evaluation of tractography reconstructions showed a great inter-algorithm variability. Although most methods found projections of the pyramidal tract from the medial portion of the motor strip, only a few algorithms could trace the lateral projections from the hand, face, and tongue area. In addition, the structure of disagreement among methods was similar across hemispheres despite the anatomical distortions caused by pathological tissues. Conclusions The DTI Challenge provides a benchmark for the standardized evaluation of tractography methods on neurosurgical data. This study suggests that there are still limitations to the clinical use of tractography for neurosurgical decision-making. PMID:26259925

  18. The impact of a patient education bundle on neurosurgery patient satisfaction

    PubMed Central

    Kliot, Tamara; Zygourakis, Corinna C.; Imershein, Sarah; Lau, Catherine; Kliot, Michel

    2015-01-01

    Background: As reimbursements and hospital/physician performance become ever more reliant on Hospital Consumer Assessment of Health Care Providers and Systems (HCAHPS) and other quality metrics, physicians are increasingly incentivized to improve patient satisfaction. Methods: A faculty and resident team at the University of California, San Francisco (UCSF) Department of Neurological Surgery developed and implemented a Patient Education Bundle. This consisted of two parts: The first was preoperative expectation letters (designed to inform patients of what to expect before, during, and after their hospitalization for a neurosurgical procedure); the second was a trifold brochure with names, photographs, and specialty/training information about the attending surgeons, resident physicians, and nurse practitioners on the neurosurgical service. We assessed patient satisfaction, as measured by HCAHPS scores and a brief survey tailored to our specific intervention, both before and after our Patient Education Bundle intervention. Results: Prior to our intervention, 74.6% of patients responded that the MD always explained information in a way that was easy to understand. After our intervention, 78.7% of patients responded that the MD always explained information in a way that was easy to understand. “Neurosurgery Patient Satisfaction survey” results showed that 83% remembered receiving the preoperative letter; of those received the letter, 93% found the letter helpful; and 100% thought that the letter should be continued. Conclusion: Although effects were modest, we believe that patient education strategies, as modeled in our bundle, can improve patients’ hospital experiences and have a positive impact on physician performance scores and hospital ratings. PMID:26664909

  19. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    NASA Astrophysics Data System (ADS)

    Alva-Sánchez, Héctor; Reynoso-Mejía, Alberto; Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús

    2014-11-01

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  20. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    SciTech Connect

    Alva-Sánchez, Héctor

    2014-11-07

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  1. Position statement from the Italian Society of Neurosurgery on the ARUBA Study.

    PubMed

    Cenzato, Marco; Delitala, Alberto; Delfini, Roberto; Pasqualin, Alberto; Maira, Giulio; Esposito, Vincenzo; Tomasello, Francesco; Boccardi, Edoardo

    2016-03-01

    As the conclusions of the ARUBA Study are strongly oriented towards therapeutic abstention, we think it is appropriate to express the concern of the Italian Society of Neurosurgery for the impact that this study might have on the health of patients, if not properly evaluated. The vast majority of patients (76-81%) included in the study was treated with endovascular or radiotherapy treatments, alone or in combination. Only 18 patients (19%) had surgery. It is well known that a partial treatment of arteriovenous malformations (AVMs), as is often the case with endovascular therapy, may increase the risk of bleeding. The primary endpoint (death or symptomatic stroke) in the treated group was reached in 30.7%, i.e. almost one-third of the subjects. This has no comparison in the current surgical literature. Considering permanent and transient neurological deficits along with headaches and seizures all together in the same outcome evaluation parameter may be inappropriate and misleading. The graph with all results from the ARUBA Study, which claims to be the demonstration that natural history is better that treatment, clearly shows that what is assumed to be treated has not actually been treated. If death or stroke occur a few years from treatment, it only means that the disease was not cured and patients received a partial - therefore ineffective, if not dangerous - treatment. An effective treatment, as surgery is, must have a flat follow-up curve. The ARUBA Study shows that incomplete treatment leads to negative outcome, confirming that an integrated multidisciplinary strategy has to be plotted out before starting any treatment and that a complete exclusion of the AVM must be achieved.

  2. Intracranial meningiomas managed at Memfys hospital for neurosurgery in Enugu, Nigeria

    PubMed Central

    Mezue, Wilfred C; Ohaegbulam, Samuel C; Ndubuisi, Chika C; Chikani, Mark C; Achebe, David S

    2012-01-01

    Introduction: The epidemiology and pathology of meningioma in Nigeria are still evolving and little has been published about this tumor in Nigeria, especially in the southeast region. The aim of this paper is to compare the characteristics of intracranial meningioma managed in our center with the pattern reported in the literature worldwide. Materials and Methods: Retrospective analysis of prospectively recorded data of patients managed for intracranial meningioma between January 2002 and December 2010 at a Private neurosurgery Hospital in Enugu, Nigeria. We excluded patients whose histology results were inconclusive. Results: Meningiomas constituted 23.8% of all intracranial tumors seen in the period. The male to female ratio was 1:1.1. The peak age range for males and females were in the fifth and sixth decades, respectively. The most common location is the Olfactory groove in 26.5% of patients followed by convexity in 23.5%. Presentation varied with anatomical location of tumor. Patients with olfactory groove meningioma (OGM) mostly presented late with personality changes and evidence of raised ICP. Tuberculum sellar and sphenoid region tumors presented earlier with visual impairment with or without hormonal abnormalities. Seizures occurred in 30.9% of all patients and in 45% of those with convexity meningiomas. Only 57.4% of the patients were managed surgically and there was no gender difference in this group. WHO grade1 tumors were the most common histological types occurring in 84.6%. One patient had atypical meningioma and two had anaplastic tumors. Conclusion: The pattern of meningioma in our area may have geographical differences in location and histology. Childhood meningioma was rare. PMID:23188985

  3. A low-cost PCI-bus-based ultrasound system for use in image-guided neurosurgery.

    PubMed

    Richard, W D; Zar, D M; LaPresto, E L; Steiner, C P

    1999-01-01

    A low-cost PCI-bus-based ultrasound sub-system has been developed and integrated into the image-guided neurosurgery system currently in use at the Cleveland Clinic. Two software applications have been developed that integrate real-time ultrasound images with preoperative MR and CT data sets. By tracking the position of the ultrasound probe during surgery, it is possible to display a real time ultrasound image and the corresponding (preoperative) oblique CT or MR slice. This provides immediate positional feedback to the neurosurgeon during the surgical procedure.

  4. First Experiences in Intensity Modulated Radiation Surgery at the National Institute of Neurology and Neurosurgery: A Dosimetric Point of View

    NASA Astrophysics Data System (ADS)

    Lárraga-Gutiérrez, José M.; Celis-López, Miguel A.

    2003-09-01

    The National Institute of Neurology and Neurosurgery in Mexico City has acquired a Novalis® shaped beam radiosurgery unit. The institute is pioneer in the use of new technologies for neuroscience. The Novalis® unit allows the use of conformal beam radiosurgery/therapy and the more advanced modality of conformal therapy: Intensity Modulated Radiation Therapy (IMRT). In the present work we present the first cases of treatments that use the IMRT technique and show its ability to protect organs at risk, such as brainstem and optical vias.

  5. Compressibility and hardness of Co-based bulk metallic glass: A combined experimental and density functional theory study

    SciTech Connect

    Wang Jianfeng; Li Ran; Xu Tao; Li Yan; Liu Zengqian; Huang Lu; Hua Nengbin; Zhang Tao; Xiao Ruijuan; Li Gong; Li Yanchun

    2011-10-10

    An incompressible Co{sub 54}Ta{sub 11}B{sub 35} bulk metallic glass (BMG) was investigated using in situ high-pressure synchrotron diffraction and nanoindendation. The elastic constants were deduced from the experiments based on the isotropic model. The Vickers hardness was measured to be 17.1 GPa. The elastic moduli and hardness are the highest values known in BMGs. The theoretically calculated elastic properties by density-functional study were well consistent with experimental measurements. The analysis of charge density and bonding character indicates the covalent character of Co-B and B-B bonds, underlying the unusually high elastic modulus and hardness in this material.

  6. Use of Modern Chemical Protein Synthesis and Advanced Fluorescent Assay Techniques to Experimentally Validate the Functional Annotation of Microbial Genomes

    SciTech Connect

    Kent, Stephen

    2012-07-20

    The objective of this research program was to prototype methods for the chemical synthesis of predicted protein molecules in annotated microbial genomes. High throughput chemical methods were to be used to make large numbers of predicted proteins and protein domains, based on microbial genome sequences. Microscale chemical synthesis methods for the parallel preparation of peptide-thioester building blocks were developed; these peptide segments are used for the parallel chemical synthesis of proteins and protein domains. Ultimately, it is envisaged that these synthetic molecules would be ‘printed’ in spatially addressable arrays. The unique ability of total synthesis to precision label protein molecules with dyes and with chemical or biochemical ‘tags’ can be used to facilitate novel assay technologies adapted from state-of-the art single molecule fluorescence detection techniques. In the future, in conjunction with modern laboratory automation this integrated set of techniques will enable high throughput experimental validation of the functional annotation of microbial genomes.

  7. Exocrine and endocrine testicular function during the treatment of experimental orchitis and nonspecific orchoepididymitis by low-energy laser radiation

    NASA Astrophysics Data System (ADS)

    Reznikov, Leonid L.; Pupkova, Ludmila S.; Bell, H.; Murzin, Alexander G.

    1995-05-01

    Investigations into the biological effects of low-energy laser radiation (LLR) are characterized by a score of challenges, which are due primarily to a cascade of laser-induced and sometimes antagonistic processes. To investigate these processes on various biologic levels, we analyzed local and general effects of LLR on the exocrine and endocrine functions of the accessory sex glands in experimentally induced orchitis and orchoepididymitis in rabbits, and in clinical studies on male patients. The results indicate that LLR may alter the inflammatory response, including the exudative reaction, macrophage migration, and fibroblast activity. Furthermore, LLR may result in changes in serum concentrations of LH, FSH, and ACTH, prolactin, testosterone, cortisol and aldosterone. Some of these changes may be at least partially responsible for the well-known anti-inflammatory effects of LLR.

  8. Subcortical ischemic vascular disease: Roles of oligodendrocyte function in experimental models of subcortical white-matter injury.

    PubMed

    Shindo, Akihiro; Liang, Anna C; Maki, Takakuni; Miyamoto, Nobukazu; Tomimoto, Hidekazu; Lo, Eng H; Arai, Ken

    2016-01-01

    Oligodendrocytes are one of the major cell types in cerebral white matter. Under normal conditions, they form myelin sheaths that encircle axons to support fast nerve conduction. Under conditions of cerebral ischemia, oligodendrocytes tend to die, resulting in white-matter dysfunction. Repair of white matter involves the ability of oligodendrocyte precursors to proliferate and mature. However, replacement of lost oligodendrocytes may not be the only mechanism for white-matter recovery. Emerging data now suggest that coordinated signaling between neural, glial, and vascular cells in the entire neurovascular unit may be required. In this mini-review, we discuss how oligodendrocyte lineage cells participate in signaling and crosstalk with other cell types to underlie function and recovery in various experimental models of subcortical white-matter injury.

  9. Morpho-functional patterns of kidney injury in the experimental leptospirosis of the guinea-pig (L. icterohaemorrhagiae).

    PubMed

    Dávila de Arriaga, A J; Rocha, A S; Yasuda, P H; De Brito, T

    1982-10-01

    Thirty-seven guinea-pigs experimentally infected with a virulent strain of L. icterohaemorrhagiae, were submitted to a renal function study as evaluated through the maximal urinary concentration (MUC) test, blood urea nitrogen (BUN) and afterwards had their kidneys examined by light and electron microscopy. Vascular changes were also studied after the administration of colloidal carbon as a marker. Through the MUC test and BUN determination, two groups of tubulo-interstitial lesions can be visualised, one in animals without renal sufficiency, manifested chiefly by cell edema with RE dilation and another, in animals with renal insufficiency, characterised not only by marked cell edema and mitochondrial changes, but also by proximal tubule regenerative aspects without overt tubular necrosis. Interstitial edema and focal nephritis was prominent in both groups, a finding which minimises their role in the pathogenesis of renal failure in experimental leptospirosis. Vascular injury, affecting the vessels of the renal microcirculation chiefly at the cortico-medular junction, was observed in both groups. Its severity and extension ran parallel to the intensity of the tubular injury. This suggests a simultaneous action of a noxious agent liberated by the leptospires over both structures, tubular damage being accentuated by the local circulatory changes. PMID:7131130

  10. Structural and optical properties of Cu doped SnO2 nanoparticles: An experimental and density functional study

    NASA Astrophysics Data System (ADS)

    Chetri, Pawan; Saikia, Bhamyarswa; Choudhury, Amarjyoti

    2013-06-01

    The paper investigates, both theoretically and experimentally, the structural and optical changes in SnO2 system brought about by introduction of Cu in a SnO2 system. On the experimental front, a cost effective sol-gel technique is used to prepare hexagonal shaped Cu doped SnO2 nanoparticles. The prepared pristine SnO2 nanoparticle is found to be of random shape by transmission electron microscope (TEM) studies. A structural and morphological study is carried out using X-ray diffraction and TEM techniques. The different phonon interaction in the system is observed by Raman spectroscopy while electron paramagnetic resonance and UV-Visible spectroscopy confirms the presence of Cu in 2+ state. First principle calculations have been performed using "density functional theory"-based MedeA Vienna Ab Initio Simulation package on a SnO2 system where Cu is introduced. The introduction of Cu in the SnO2 system brings distortion which is corroborated by the variation in the corresponding bond lengths. The Density of State calculation of Sn16O32 and CuSn15O32 is also performed. Finally, a correlation is established between the experiment and the theory.

  11. Experimental Determination of the Dynamic Hydraulic Transfer Function for the J-2X Oxidizer Turbopump. Part One; Methodology

    NASA Technical Reports Server (NTRS)

    Zoladz, Tom; Patel, Sandeep; Lee, Erik; Karon, Dave

    2011-01-01

    An advanced methodology for extracting the hydraulic dynamic pump transfer matrix (Yp) for a cavitating liquid rocket engine turbopump inducer+impeller has been developed. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Laboratory pulsed subscale waterflow test of the J-2X oxygen turbo pump is introduced and our new extraction method applied to the data collected. From accurate measures of pump inlet and discharge perturbational mass flows and pressures, and one-dimensional flow models that represents complete waterflow loop physics, we are able to derive Yp and hence extract the characteristic pump parameters: compliance, pump gain, impedance, mass flow gain. Detailed modeling is necessary to accurately translate instrument plane measurements to the pump inlet and discharge and extract Yp. We present the MSFC Dynamic Lump Parameter Fluid Model Framework and describe critical dynamic component details. We report on fit minimization techniques, cost (fitness) function derivation, and resulting model fits to our experimental data are presented. Comparisons are made to alternate techniques for spatially translating measurement stations to actual pump inlet and discharge.

  12. Experimental warming alters spring phenology of certain plant functional groups in an early-successional forest community.

    PubMed

    Rollinson, C R; Kaye, M W

    2012-01-01

    Experimental study of the effects of projected climate change on plant phenology allows us to isolate effects of warming on life history events such as leaf out. We simulated a 2°C temperature increase and 20% precipitation increase in a recently harvested temperate deciduous forest community in central Pennsylvania, USA, and observed the leaf out phenology of all species in 2009 and 2010. Over 130 plant species were monitored weekly in study plots, but due to high variability in species composition among plots, species were grouped into five functional groups: short forbs, tall forbs, shrubs, small trees, and large trees. Tall forbs and large trees, which usually emerge in the late spring, advanced leaf out 14-18 days in response to warming. Short forbs, shrubs, and small trees emerge early in spring and did not alter their phenology in response to warming or increased precipitation treatments. Earlier leaf out of tall forbs and large trees coincided with almost three weeks of increased community-level leaf area index (LAI), indicating greater competition and a condensed spring green-up period. While phenology of large trees and tall forbs appears to be strongly influenced by temperature-based growth cues, our results suggest that photoperiod and chilling cues more strongly influence the leaf out of other functional groups. Reduced freeze events and warmer temperatures from predicted climate change will interact with non-temperature growth cues to have cascading consequences throughout the ecosystem.

  13. Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury

    PubMed Central

    West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

    2014-01-01

    Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day−1, 5 days week−1 for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI. PMID:24535438

  14. Thiol Functionalized Silica-Mixed Matrix Membranes for Silver Capture from Aqueous Solutions: Experimental Results and Modeling

    PubMed Central

    Ladhe, A. R.; Frailie, P.; Hua, D.; Darsillo, M.; Bhattacharyya, D.

    2009-01-01

    The study deals with an aqueous phase application of Mixed Matrix Membranes (MMMs) for silver ion (Ag+) capture. Silica particles were functionalized with 3-mercaptopropyltrimethoxy silane (MPTMS) to introduce free thiol (-SH) groups on the surface. The particles were used as the dispersed phase in the polysulfone or cellulose acetate polymer matrix. The membranes were prepared by the phase inversion method to create more open and interconnected porous structures suitable for liquid phase applications. The effects of the silica properties such as particle size, specific surface area, and porous/nonporous morphology on the silver ion capture capacity were studied. It was demonstrated that the membranes are capable of selectively capturing silver from a solution containing significant concentrations of other metal ions like Ca2+. The membranes were studied to quantify the dynamic capacity for silver ion capture and its dependence on residence time through the adjustment of transmembrane pressure. The thiol-Ag+ interaction was quantified with Quartz Crystal Microbalance in a continuous flow mode experiment and the observations were compared with the membrane results. One dimensional unsteady state model with overall volumetric mass transfer coefficient was developed and solved to predict the silver concentration in the liquid phase and the solid silica phase along the membrane thickness at varying time. The breakthrough data predicted using the model is comparable with the experimental observations. The study demonstrates successful application of the functionalized silica-mixed matrix membranes for selective aqueous phase Ag+ capture with high capacity at low transmembrane pressures. The technique can be easily extended to other applications by altering the functionalized groups on the silica particles. PMID:20098490

  15. In situ synthesis and surface functionalization of gold nanoparticles with curcumin and their antioxidant properties: an experimental and density functional theory investigation

    NASA Astrophysics Data System (ADS)

    Singh, Dheeraj K.; Jagannathan, Ramya; Khandelwal, Puneet; Abraham, Priya Mary; Poddar, Pankaj

    2013-02-01

    Curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is an active component of turmeric; it is responsible for its characteristic yellow color and therapeutic potential, but its poor bioavailability remains a major challenge. In order to improve the bioavailability of curcumin, various approaches have been used. One of the possible approaches to increase the bioavailability of curcumin is its conjugation on the surface of metal nanoparticles. Therefore, in the present study, we report the binding of curcumin on the surface of gold nanoparticles (AuNPs). The AuNPs were synthesized by the direct reduction of HAuCl4 using curcumin in the aqueous phase, without the use of any other reducing agents. We found that curcumin acts both as a reducing and capping agent, stabilizing the gold sol for many months. Moreover, these curcumin-capped AuNPs also show good antioxidant activity which was confirmed by the DPPH (2,2-diphenyl-l-picrylhydrazyl) radical test. Thus, the surface functionalization of AuNPs with curcumin may pave a new way of using the curcuminoids towards possible drug delivery and therapeutics. Apart from the experimental study, a detailed quantum chemical calculation using density functional theory (DFT) has been performed, in order to investigate the formation of a complex of curcumin with Au3+ ions in different possible conformational isomeric forms. Our theoretical calculations indicate the evidence of electron transfer from curcumin into the Au center and essentially indicate that as a consequence of complexation, Au3+ ions are reduced to Au0. Our theoretical results also propose that it is the breakage of intramolecular H-bonding that probably leads to the increased availability of curcumin in the presence of gold ions and water molecules.Curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is an active component of turmeric; it is responsible for its characteristic yellow color and therapeutic

  16. Generating information-rich high-throughput experimental materials genomes using functional clustering via multitree genetic programming and information theory.

    PubMed

    Suram, Santosh K; Haber, Joel A; Jin, Jian; Gregoire, John M

    2015-04-13

    High-throughput experimental methodologies are capable of synthesizing, screening and characterizing vast arrays of combinatorial material libraries at a very rapid rate. These methodologies strategically employ tiered screening wherein the number of compositions screened decreases as the complexity, and very often the scientific information obtained from a screening experiment, increases. The algorithm used for down-selection of samples from higher throughput screening experiment to a lower throughput screening experiment is vital in achieving information-rich experimental materials genomes. The fundamental science of material discovery lies in the establishment of composition-structure-property relationships, motivating the development of advanced down-selection algorithms which consider the information value of the selected compositions, as opposed to simply selecting the best performing compositions from a high throughput experiment. Identification of property fields (composition regions with distinct composition-property relationships) in high throughput data enables down-selection algorithms to employ advanced selection strategies, such as the selection of representative compositions from each field or selection of compositions that span the composition space of the highest performing field. Such strategies would greatly enhance the generation of data-driven discoveries. We introduce an informatics-based clustering of composition-property functional relationships using a combination of information theory and multitree genetic programming concepts for identification of property fields in a composition library. We demonstrate our approach using a complex synthetic composition-property map for a 5 at. % step ternary library consisting of four distinct property fields and finally explore the application of this methodology for capturing relationships between composition and catalytic activity for the oxygen evolution reaction for 5429 catalyst compositions in a

  17. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    SciTech Connect

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto; Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela; Gutiérrez, Silvina; Torres, Alicia Inés; De Paul, Ana Lucía

    2013-11-15

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  18. Experimental drought induces short-term changes in soil functionality and microbial community structure after fire in a Mediterranean shrubland

    NASA Astrophysics Data System (ADS)

    Hinojosa, M. B.; Parra, A.; Laudicina, V. A.; Moreno, J. M.

    2014-10-01

    Fire is a major ecosystem driver, causing significant changes in soil nutrients and microbial community structure and functionality. Post-fire soil dynamics can vary depending on rainfall patterns, although variations in response to drought are poorly known. This is particularly important in areas with poor soils and limited rainfall, like arid and semiarid ones. Furthermore, climate change projections in many such areas anticipate reduced precipitation and longer drought, together with an increase in fire severity. The effects of experimental drought and fire were studied on soils in a Mediterranean Cistus-Erica shrubland in Central Spain. A replicated (n = 4) field experiment was carried out in which four levels of rainfall pattern were implemented by means of a rain-out shelters and irrigation system. The treatments were: environmental control (natural rainfall), historical control (long-term average rainfall, 2 months drought), moderate drought (25% reduction of historical control, 5 months drought) and severe drought (45% reduction, 7 months drought). After one growing season, the plots were burned with high fire intensity, except a set of unburned plots that served as control. Soils were collected seasonally during one year and variables related to soil nutrient availability and microbial community structure and functionality were studied. Burned soils increased nutrient availability (P, N, K) with respect to unburned ones, but drought reduced such an increase in P, while it further increased N and K. Such changes in available soil nutrients were short-lived. Drought caused a further decrease of enzyme activities, carbon mineralization rate and microbial biomass. Fire decreased the relative abundance of fungi and actinomycetes. However, fire and drought caused a further reduction in fungi, with bacteria becoming relatively more abundant. Arguably, increasing drought and fires due to climate change will likely shift soil recovery after fire.

  19. The Effect of Oral Morphine on Pain-Related Brain Activation - An Experimental Functional Magnetic Resonance Imaging Study.

    PubMed

    Hansen, Tine Maria; Olesen, Anne Estrup; Graversen, Carina; Drewes, Asbjørn Mohr; Frøkjaer, Jens Brøndum

    2015-11-01

    Knowledge about cerebral mechanisms underlying pain perception and effect of analgesic drugs is important for developing methods for diagnosis and treatment of pain. The aim was to explore altered brain activation before and after morphine treatment using functional magnetic resonance imaging recorded during experimental painful heat stimulation. Functional magnetic resonance imaging data were recorded and analysed in 20 healthy volunteers (13 men and 7 women, 24.9 ± 2.6 years) in a randomized, double-blind, placebo-controlled, cross-over study. Painful stimulations were applied to the right forearm using a contact heat evoked potential stimulator (CHEPS) before and after treatment with 30 mg oral morphine and placebo. CHEPS stimulations before treatment induced activation in the anterior cingulate cortex, secondary somatosensory cortex/insula, thalamus and cerebellum (n = 16, p < 0.05). In response to morphine treatment, the spatial extent of these pain-specific areas decreased (n = 20). Reduced pain-induced activation was seen in the right insula, anterior cingulate cortex and inferior parietal cortex after morphine treatment compared to before treatment (n = 16, p < 0.05), and sensory ratings of pain perception were significantly reduced after morphine treatment (p = 0.02). No effect on pain-induced brain activation was seen after placebo treatment compared to before treatment (n = 12, p > 0.05). In conclusion, heat stimulation activated areas in the 'pain matrix' and a clinically relevant dose of orally administered morphine revealed significant changes in brain areas where opioidergic pathways are predominant. The method may be useful to investigate the mechanisms of analgesics.

  20. Experimentally reduced root–microbe interactions reveal limited plasticity in functional root traits in Acer and Quercus

    PubMed Central

    Lee, Mei-Ho; Comas, Louise H.; Callahan, Hilary S.

    2014-01-01

    Background and Aims Interactions between roots and soil microbes are critical components of below-ground ecology. It is essential to quantify the magnitude of root trait variation both among and within species, including variation due to plasticity. In addition to contextualizing the magnitude of plasticity relative to differences between species, studies of plasticity can ascertain if plasticity is predictable and whether an environmental factor elicits changes in traits that are functionally advantageous. Methods To compare functional traits and trait plasticities in fine root tissues with natural and reduced levels of colonization by microbial symbionts, trimmed and surface-sterilized root segments of 2-year-old Acer rubrum and Quercus rubra seedlings were manipulated. Segments were then replanted into satellite pots filled with control or heat-treated soil, both originally derived from a natural forest. Mycorrhizal colonization was near zero in roots grown in heat-treated soil; roots grown in control soil matched the higher colonization levels observed in unmanipulated root samples collected from field locations. Key Results Between-treatment comparisons revealed negligible plasticity for root diameter, branching intensity and nitrogen concentration across both species. Roots from treated soils had decreased tissue density (approx. 10–20 %) and increased specific root length (approx. 10–30 %). In contrast, species differences were significant and greater than treatment effects in traits other than tissue density. Interspecific trait differences were also significant in field samples, which generally resembled greenhouse samples. Conclusions The combination of experimental and field approaches was useful for contextualizing trait plasticity in comparison with inter- and intra-specific trait variation. Findings that root traits are largely species dependent, with the exception of root tissue density, are discussed in the context of current literature on root

  1. Separation of experimental 2D IR frequency-frequency correlation functions into structural and reorientation-induced contributions

    NASA Astrophysics Data System (ADS)

    Kramer, Patrick L.; Nishida, Jun; Fayer, Michael D.

    2015-09-01

    A vibrational transition frequency can couple to its environment through a directional vector interaction. In such cases, reorientation of the vibrational transition dipole (molecular orientational relaxation) and its frequency fluctuations can be strongly coupled. It was recently shown [Kramer et al., J. Chem. Phys. 142, 184505 (2015)] that differing frequency-frequency correlation function (FFCF) decays, due to reorientation-induced spectral diffusion (RISD), are observed with different two-dimensional infrared polarization configurations when such strong coupling is present. The FFC functional forms were derived for the situation in which all spectral diffusion is due to reorientational motion. We extend the previous theory to include vibrational frequency evolution (spectral diffusion) caused by structural fluctuations of the medium. Model systems with diffusive reorientation and several regimes of structural spectral diffusion rates are analyzed for first order Stark effect interactions. Additionally, the transition dipole reorientational motion in complex environments is frequently not completely diffusive. Several periods of restricted angular motion (wobbling-in-a-cone) may precede the final diffusive orientational randomization. The polarization-weighted FFCF decays are presented in this case of restricted transition dipole wobbling. With these extensions to the polarization-dependent FFCF expressions, the structural spectral diffusion dynamics of methanol in the room temperature ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate can be separated quantitatively from RISD using the experimental center line slope data. In addition, prior results on the spectral diffusion of water, methanol, and ethanol in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide are re-examined to elucidate the influence of reorientation on the data, which were interpreted in terms of structural fluctuations.

  2. Functional adaptation of crustacean exoskeletal elements through structural and compositional diversity: a combined experimental and theoretical study.

    PubMed

    Fabritius, Helge-Otto; Ziegler, Andreas; Friák, Martin; Nikolov, Svetoslav; Huber, Julia; Seidl, Bastian H M; Ruangchai, Sukhum; Alagboso, Francisca I; Karsten, Simone; Lu, Jin; Janus, Anna M; Petrov, Michal; Zhu, Li-Fang; Hemzalová, Pavlína; Hild, Sabine; Raabe, Dierk; Neugebauer, Jörg

    2016-01-01

    The crustacean cuticle is a composite material that covers the whole animal and forms the continuous exoskeleton. Nano-fibers composed of chitin and protein molecules form most of the organic matrix of the cuticle that, at the macroscale, is organized in up to eight hierarchical levels. At least two of them, the exo- and endocuticle, contain a mineral phase of mainly Mg-calcite, amorphous calcium carbonate and phosphate. The high number of hierarchical levels and the compositional diversity provide a high degree of freedom for varying the physical, in particular mechanical, properties of the material. This makes the cuticle a versatile material ideally suited to form a variety of skeletal elements that are adapted to different functions and the eco-physiological strains of individual species. This review presents our recent analytical, experimental and theoretical studies on the cuticle, summarising at which hierarchical levels structure and composition are modified to achieve the required physical properties. We describe our multi-scale hierarchical modeling approach based on the results from these studies, aiming at systematically predicting the structure-composition-property relations of cuticle composites from the molecular level to the macro-scale. This modeling approach provides a tool to facilitate the development of optimized biomimetic materials within a knowledge-based design approach. PMID:27609556

  3. Scaffold microstructure effects on functional and mechanical performance: Integration of theoretical and experimental approaches for bone tissue engineering applications.

    PubMed

    Cavo, Marta; Scaglione, Silvia

    2016-11-01

    The really nontrivial goal of tissue engineering is combining all scaffold micro-architectural features, affecting both fluid-dynamical and mechanical performance, to obtain a fully functional implant. In this work we identified an optimal geometrical pattern for bone tissue engineering applications, best balancing several graft needs which correspond to competing design goals. In particular, we investigated the occurred changes in graft behavior by varying pore size (300μm, 600μm, 900μm), interpore distance (equal to pore size or 300μm fixed) and pores interconnection (absent, 45°-oriented, 90°-oriented). Mathematical considerations and Computational Fluid Dynamics (CFD) tools, here combined in a complete theoretical model, were carried out to this aim. Poly-lactic acid (PLA) based samples were realized by 3D printing, basing on the modeled architectures. A collagen (COL) coating was also realized on grafts surface and the interaction between PLA and COL, besides the protein contribution to graft bioactivity, was evaluated. Scaffolds were extensively characterized; human articular cells were used to test their biocompatibility and to evaluate the theoretical model predictions. Grafts fulfilled both the chemical and physical requirements. Finally, a good agreement was found between the theoretical model predictions and the experimental data, making these prototypes good candidates for bone graft replacements.

  4. Experimental Strategies for Functional Annotation and Metabolism Discovery: Targeted Screening of Solute Binding Proteins and Unbiased Panning of Metabolomes

    PubMed Central

    2015-01-01

    The rate at which genome sequencing data is accruing demands enhanced methods for functional annotation and metabolism discovery. Solute binding proteins (SBPs) facilitate the transport of the first reactant in a metabolic pathway, thereby constraining the regions of chemical space and the chemistries that must be considered for pathway reconstruction. We describe high-throughput protein production and differential scanning fluorimetry platforms, which enabled the screening of 158 SBPs against a 189 component library specifically tailored for this class of proteins. Like all screening efforts, this approach is limited by the practical constraints imposed by construction of the library, i.e., we can study only those metabolites that are known to exist and which can be made in sufficient quantities for experimentation. To move beyond these inherent limitations, we illustrate the promise of crystallographic- and mass spectrometric-based approaches for the unbiased use of entire metabolomes as screening libraries. Together, our approaches identified 40 new SBP ligands, generated experiment-based annotations for 2084 SBPs in 71 isofunctional clusters, and defined numerous metabolic pathways, including novel catabolic pathways for the utilization of ethanolamine as sole nitrogen source and the use of d-Ala-d-Ala as sole carbon source. These efforts begin to define an integrated strategy for realizing the full value of amassing genome sequence data. PMID:25540822

  5. Optimal electron irradiation as a tool for functionalization of MoS{sub 2}: Theoretical and experimental investigation

    SciTech Connect

    Karmakar, Debjani Padma, N.; Ghosh, M.; Kaur, M.; Chandrasekhar Rao, T. V.; Halder, Rumu; Abraham, Geogy; Vaibhav, K.; Bhattacharya, D.

    2015-04-07

    We demonstrate the utility of electron irradiation as a tool to enhance device functionality of graphene-analogous MoS{sub 2}. With the help of first-principles based calculations, vacancy-induced changes of various electronic properties are shown to be a combined result of crystal-field modification and spin-orbital coupling. A comparative theoretical study of various possible vacancy configurations both in bulk and monolayer MoS{sub 2} and related changes in their respective band-structures help us to explain plausible irradiation induced effects. Experimentally, various structural forms of MoS{sub 2} in bulk, few layered flakes, and nanocrystals are observed to exhibit important modification of their magnetic, transport, and vibrational properties, following low doses of electron irradiation. While irradiated single crystals and nanocrystals show an enhanced magnetization, transport properties of few-layered devices show a significant increase in their conductivity, which can be very useful for fabrication of electronic devices. Our theoretical calculations reveal that this increase in n-type conductivity and magnetization can be correlated with the presence of sulfur and molybdenum vacancies.

  6. Novel Function of Extracellular Matrix Protein 1 in Suppressing Th17 Cell Development in Experimental Autoimmune Encephalomyelitis.

    PubMed

    Su, Pan; Chen, Sheng; Zheng, Yu Han; Zhou, Hai Yan; Yan, Cheng Hua; Yu, Fang; Zhang, Ya Guang; He, Lan; Zhang, Yuan; Wang, Yanming; Wu, Lei; Wu, Xiaoai; Yu, Bingke; Ma, Li Yan; Yang, Zhiru; Wang, Jianhua; Zhao, Guixian; Zhu, Jinfang; Wu, Zhi-Ying; Sun, Bing

    2016-08-15

    Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS characterized by demyelination and axonal damage. Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model for human MS. Although Th17 cells are important for disease induction, Th2 cells are inhibitory in this process. In this article, we report the effect of a Th2 cell product, extracellular matrix protein 1 (ECM1), on the differentiation of Th17 cells and the development of EAE. Our results demonstrated that ECM1 administration from day 1 to day 7 following the EAE induction could ameliorate the Th17 cell responses and EAE development in vivo. Further study of the mechanism revealed that ECM1 could interact with αv integrin on dendritic cells and block the αv integrin-mediated activation of latent TGF-β, resulting in an inhibition of Th17 cell differentiation at an early stage of EAE induction. Furthermore, overexpression of ECM1 in vivo significantly inhibited the Th17 cell response and EAE induction in ECM1 transgenic mice. Overall, our work has identified a novel function of ECM1 in inhibiting Th17 cell differentiation in the EAE model, suggesting that ECM1 may have the potential to be used in clinical applications for understanding the pathogenesis of MS and its diagnosis. PMID:27316685

  7. Scaffold microstructure effects on functional and mechanical performance: Integration of theoretical and experimental approaches for bone tissue engineering applications.

    PubMed

    Cavo, Marta; Scaglione, Silvia

    2016-11-01

    The really nontrivial goal of tissue engineering is combining all scaffold micro-architectural features, affecting both fluid-dynamical and mechanical performance, to obtain a fully functional implant. In this work we identified an optimal geometrical pattern for bone tissue engineering applications, best balancing several graft needs which correspond to competing design goals. In particular, we investigated the occurred changes in graft behavior by varying pore size (300μm, 600μm, 900μm), interpore distance (equal to pore size or 300μm fixed) and pores interconnection (absent, 45°-oriented, 90°-oriented). Mathematical considerations and Computational Fluid Dynamics (CFD) tools, here combined in a complete theoretical model, were carried out to this aim. Poly-lactic acid (PLA) based samples were realized by 3D printing, basing on the modeled architectures. A collagen (COL) coating was also realized on grafts surface and the interaction between PLA and COL, besides the protein contribution to graft bioactivity, was evaluated. Scaffolds were extensively characterized; human articular cells were used to test their biocompatibility and to evaluate the theoretical model predictions. Grafts fulfilled both the chemical and physical requirements. Finally, a good agreement was found between the theoretical model predictions and the experimental data, making these prototypes good candidates for bone graft replacements. PMID:27524090

  8. Density functional investigation of photo induced Intramolecular Proton Transfer (IPT) in Indole-7-carboxaldehyde and its experimental verification

    NASA Astrophysics Data System (ADS)

    Singla, Nidhi; Chowdhury, Papia

    2013-08-01

    A detail theoretical study has been performed using Density functional theory (DFT) and Time dependent DFT (TDDFT) to investigate the Intramolecular Proton Transfer (IPT) mechanism in Indole-7-carboxaldehyde (I7C) from its normal (I*) to zwitterion (II*) form. B3LYP/6-311++G (d, p) basis set has been used to obtain structural parameters and relative energies in the ground state (S0) and excited state (S1). Atoms in Molecules (AIMs), Mulliken and Natural bond orbitals (NBOs) analysis proves the existence of intramolecular hydrogen bonding (IHB). The electron density (ρ) at Bond critical points (BCPs) on a hydrogen bridge (N15sbnd H12⋯O18) certify IHB and possibility of IPT from acidic (N15sbnd H12) to basic (lbond2 C16dbnd O18) group and creation of II*. Transition state (TS) with dual minima in the Potential energy surface (PES) confirms the I* → TS → II* transition due to excited state Intramolecular Proton Transfer (ESIPT). Photo-physical pathway from I* → II* agrees well with computed/experimental emission peaks.

  9. Experimental strategies for functional annotation and metabolism discovery: targeted screening of solute binding proteins and unbiased panning of metabolomes.

    PubMed

    Vetting, Matthew W; Al-Obaidi, Nawar; Zhao, Suwen; San Francisco, Brian; Kim, Jungwook; Wichelecki, Daniel J; Bouvier, Jason T; Solbiati, Jose O; Vu, Hoan; Zhang, Xinshuai; Rodionov, Dmitry A; Love, James D; Hillerich, Brandan S; Seidel, Ronald D; Quinn, Ronald J; Osterman, Andrei L; Cronan, John E; Jacobson, Matthew P; Gerlt, John A; Almo, Steven C

    2015-01-27

    The rate at which genome sequencing data is accruing demands enhanced methods for functional annotation and metabolism discovery. Solute binding proteins (SBPs) facilitate the transport of the first reactant in a metabolic pathway, thereby constraining the regions of chemical space and the chemistries that must be considered for pathway reconstruction. We describe high-throughput protein production and differential scanning fluorimetry platforms, which enabled the screening of 158 SBPs against a 189 component library specifically tailored for this class of proteins. Like all screening efforts, this approach is limited by the practical constraints imposed by construction of the library, i.e., we can study only those metabolites that are known to exist and which can be made in sufficient quantities for experimentation. To move beyond these inherent limitations, we illustrate the promise of crystallographic- and mass spectrometric-based approaches for the unbiased use of entire metabolomes as screening libraries. Together, our approaches identified 40 new SBP ligands, generated experiment-based annotations for 2084 SBPs in 71 isofunctional clusters, and defined numerous metabolic pathways, including novel catabolic pathways for the utilization of ethanolamine as sole nitrogen source and the use of d-Ala-d-Ala as sole carbon source. These efforts begin to define an integrated strategy for realizing the full value of amassing genome sequence data.

  10. Determining the Mechanical Constitutive Properties of Metals as Function of Strain Rate and temperature: A Combined Experimental and Modeling Approach

    SciTech Connect

    Ian Robertson

    2007-04-28

    Development and validation of constitutive models for polycrystalline materials subjected to high strain-rate loading over a range of temperatures are needed to predict the response of engineering materials to in-service type conditions. To account accurately for the complex effects that can occur during extreme and variable loading conditions, requires significant and detailed computational and modeling efforts. These efforts must be integrated fully with precise and targeted experimental measurements that not only verify the predictions of the models, but also provide input about the fundamental processes responsible for the macroscopic response. Achieving this coupling between modeling and experiment is the guiding principle of this program. Specifically, this program seeks to bridge the length scale between discrete dislocation interactions with grain boundaries and continuum models for polycrystalline plasticity. Achieving this goal requires incorporating these complex dislocation-interface interactions into the well-defined behavior of single crystals. Despite the widespread study of metal plasticity, this aspect is not well understood for simple loading conditions, let alone extreme ones. Our experimental approach includes determining the high-strain rate response as a function of strain and temperature with post-mortem characterization of the microstructure, quasi-static testing of pre-deformed material, and direct observation of the dislocation behavior during reloading by using the in situ transmission electron microscope deformation technique. These experiments will provide the basis for development and validation of physically-based constitutive models. One aspect of the program involves the direct observation of specific mechanisms of micro-plasticity, as these indicate the boundary value problem that should be addressed. This focus on the pre-yield region in the quasi-static effort (the elasto-plastic transition) is also a tractable one from an

  11. Source Function applied to experimental densities reveals subtle electron-delocalization effects and appraises their transferability properties in crystals.

    PubMed

    Gatti, Carlo; Saleh, Gabriele; Lo Presti, Leonardo

    2016-04-01

    The Source Function (SF), introduced in 1998 by Richard Bader and Carlo Gatti, is succinctly reviewed and a number of paradigmatic applications to in vacuo and crystal systems are illustrated to exemplify how the SF may be used to discuss chemical bonding in both conventional and highly challenging cases. The SF enables the electron density to be seen at a point determined by source contributions from the atoms or a group of atoms of a system, and it is therefore well linked to the chemist's awareness that any local property and chemical behaviour is to some degree influenced by all the remaining parts of a system. The key and captivating feature of the SF is that its evaluation requires only knowledge of the electron density (ED) of a system, thereby enabling a comparison of ab initio and X-ray diffraction derived electron density properties on a common and rigorous basis. The capability of the SF to detect electron-delocalization effects and to quantify their degree of transferability is systematically explored in this paper through the analysis and comparison of experimentally X-ray derived Source Function patterns in benzene, naphthalene and (±)-8'-benzhydrylideneamino-1,1'-binaphthyl-2-ol (BAB) molecular crystals. It is shown that the SF tool recovers the characteristic SF percentage patterns caused by π-electron conjugation in the first two paradigmatic aromatic molecules in almost perfect quantitative agreement with those obtained from ab initio periodic calculations. Moreover, the effect of chemical substitution on the degree of transferability of such patterns to the benzene- and naphthalene-like moieties of BAB is neatly shown and quantified by the observed systematic deviations, relative to benzene and naphthalene, of only those SF contributions from the substituted C atoms. Finally, the capability of the SF to reveal electron-delocalization effects is challenged by using a promolecule density, rather than the proper quantum mechanical density, to

  12. Cancer treatment and gonadal function: experimental and established strategies for fertility preservation in children and young adults.

    PubMed

    Anderson, Richard A; Mitchell, Rod T; Kelsey, Thomas W; Spears, Norah; Telfer, Evelyn E; Wallace, W Hamish B

    2015-07-01

    Preservation of gonadal function is an important priority for the long-term health of cancer survivors of both sexes and all ages at treatment. Loss of opportunity for fertility is a prime concern in both male and female cancer survivors, but endocrine effects of gonadal damage are likewise central to long-term health and wellbeing. Some fertility preservation techniques, such as semen and embryo cryopreservation, are established and successful in adults, and development of oocyte vitrification has greatly improved the potential to cryopreserve unfertilised oocytes. Despite being recommended for all pubertal male patients, sperm banking is not universally practised in paediatric oncology centres, and very few adolescent-friendly facilities exist. All approaches to fertility preservation have specific challenges in children and teenagers, including ethical, practical, and scientific issues. For young women, cryopreservation of ovarian cortical tissue with later replacement has resulted in at least 40 livebirths, but is still regarded as experimental in most countries. For prepubertal boys, testicular biopsy cryopreservation is offered in some centres, but how that tissue might be used in the future is unclear, and so far no evidence suggests that fertility can be restored. For both sexes, these approaches involve an invasive procedure and have an uncertain risk of tissue contamination in haematological and other malignancies. Decision making for all these approaches needs assessment of the individual's risk of fertility loss, and is made at a time of emotional distress. Development of this specialty needs better provision of information for patients and their medical teams, and improvements in service provision, to match technical and scientific advances.

  13. Functional Responses of Bacterioplankton Diversity and Metabolism to Experimental Bottom-Up and Top-Down Forcings.

    PubMed

    Pradeep Ram, A S; Chaibi-Slouma, S; Keshri, J; Colombet, J; Sime-Ngando, T

    2016-08-01

    We conducted an experimental approach using microcosms to simultaneously examine the functional response of natural freshwater bacterial assemblages to the impact of resources (nutrients) and top-down factors (viruses and grazers) on bacterial physiological state and their community structure. Addition of organic and inorganic nutrients led to the proliferation of high nucleic acid content bacterial cells accompanied by high bacterial growth efficiency (considered as proxy of bacterial carbon metabolism) estimates, suggesting that this subgroup represented the most active fraction of bacterial community and had a high capacity to incorporate carbon into its biomass. However, their rapid growth induced the pressure of viral lytic infection which led to their lysis toward the end of the experiment. In microcosms with flagellates plus viruses, and with viruses alone, the selective removal of metabolically active high nucleic acid cells through viral lysis benefitted the less active low nucleic acid content cells, perhaps via the use of lysis products for its growth and survival. Changes in bacterial physiological state in microcosms were reflected in their community structure which was examined using 16S ribosomal RNA (rRNA) gene sequencing by Illumina's Miseq platform. Chao estimator and Shannon diversity index values suggested that bacterial species richness was highest in the presence of both the top-down factors, indicating a tighter control of bacterioplankton dominants within a relatively stable bacterial community. The increase in bacterial metabolism with nutrient addition followed by subsequent lysis of bacterial dominants indicate that both resources and top-down factors work in concert for the sustenance of stable bacterial communities. PMID:27179523

  14. Exogenous connexin43-expressing autologous skeletal myoblasts ameliorate mechanical function and electrical activity of the rabbit heart after experimental infarction.

    PubMed

    Antanavičiūtė, Ieva; Ereminienė, Eglė; Vysockas, Vaidas; Račkauskas, Mindaugas; Skipskis, Vilius; Rysevaitė, Kristina; Treinys, Rimantas; Benetis, Rimantas; Jurevičius, Jonas; Skeberdis, Vytenis A

    2015-02-01

    Acute myocardial infarction is one of the major causes of mortality worldwide. For regeneration of the rabbit heart after experimentally induced infarction we used autologous skeletal myoblasts (SMs) due to their high proliferative potential, resistance to ischaemia and absence of immunological and ethical concerns. The cells were characterized with muscle-specific and myogenic markers. Cell transplantation was performed by injection of cell suspension (0.5 ml) containing approximately 6 million myoblasts into the infarction zone. The animals were divided into four groups: (i) no injection; (ii) sham injected; (iii) injected with wild-type SMs; and (iv) injected with SMs expressing connexin43 fused with green fluorescent protein (Cx43EGFP). Left ventricular ejection fraction (LVEF) was evaluated by 2D echocardiography in vivo before infarction, when myocardium has stabilized after infarction, and 3 months after infarction. Electrical activity in the healthy and infarction zones of the heart was examined ex vivo in Langendorff-perfused hearts by optical mapping using di-4-ANEPPS, a potential sensitive fluorescent dye. We demonstrate that SMs in the coculture can couple electrically not only to abutted but also to remote acutely isolated allogenic cardiac myocytes through membranous tunnelling tubes. The beneficial effect of cellular therapy on LVEF and electrical activity was observed in the group of animals injected with Cx43EGFP-expressing SMs. L-type Ca(2+) current amplitude was approximately fivefold smaller in the isolated SMs compared to healthy myocytes suggesting that limited recovery of LVEF may be related to inadequate expression or function of L-type Ca(2+) channels in transplanted differentiating SMs. PMID:25529770

  15. Functional Responses of Bacterioplankton Diversity and Metabolism to Experimental Bottom-Up and Top-Down Forcings.

    PubMed

    Pradeep Ram, A S; Chaibi-Slouma, S; Keshri, J; Colombet, J; Sime-Ngando, T

    2016-08-01

    We conducted an experimental approach using microcosms to simultaneously examine the functional response of natural freshwater bacterial assemblages to the impact of resources (nutrients) and top-down factors (viruses and grazers) on bacterial physiological state and their community structure. Addition of organic and inorganic nutrients led to the proliferation of high nucleic acid content bacterial cells accompanied by high bacterial growth efficiency (considered as proxy of bacterial carbon metabolism) estimates, suggesting that this subgroup represented the most active fraction of bacterial community and had a high capacity to incorporate carbon into its biomass. However, their rapid growth induced the pressure of viral lytic infection which led to their lysis toward the end of the experiment. In microcosms with flagellates plus viruses, and with viruses alone, the selective removal of metabolically active high nucleic acid cells through viral lysis benefitted the less active low nucleic acid content cells, perhaps via the use of lysis products for its growth and survival. Changes in bacterial physiological state in microcosms were reflected in their community structure which was examined using 16S ribosomal RNA (rRNA) gene sequencing by Illumina's Miseq platform. Chao estimator and Shannon diversity index values suggested that bacterial species richness was highest in the presence of both the top-down factors, indicating a tighter control of bacterioplankton dominants within a relatively stable bacterial community. The increase in bacterial metabolism with nutrient addition followed by subsequent lysis of bacterial dominants indicate that both resources and top-down factors work in concert for the sustenance of stable bacterial communities.

  16. From anesthetic sponge to nonsinking skull perforator, unitary work neurosurgery in the ancient Arabic and Islamic world.

    PubMed

    Najjar, Jalal

    2010-05-01

    During the Middle Ages, the work of Middle Eastern physicians such as Avicenna, Albucasis, and Rhazes was of paramount importance in guarding the knowledge that had been accumulated throughout history, particularly the contributions of Greek and Roman scholars, and it is well known that the Arabic versions of all of the works by Hippocrates and Galen by Islamic and Arabic scholars are the only copies that have survived until now. In addition to preserving this wealth of knowledge, these Middle Eastern scholars made significant contributions of their own to both medicine and neurosurgery. Many points regarding ancient Arabic and Islamic science need to be discussed and clarified, such as cadaver dissections, anatomic studies, neurosurgical practice and instruments, Arabic translations of Hippocratic and other works, and the influence of the Islamic civilization on Western civilization, especially the Renaissance.

  17. Systematic reviews and meta-analyses in spine surgery, neurosurgery and orthopedics: guidelines for the surgeon scientist

    PubMed Central

    Mobbs, Ralph J.

    2015-01-01

    The research evidence in the realm of surgery is expanding at a rapid pace, and thus corresponds with an increasing need to critically appraise and synthesize the available literature. Particularly in fields such as spine surgery, neurosurgery and orthopedics which traditionally have little Class I randomized clinical data, reviews are important to pool the available evidence on clinical questions which are otherwise difficult to answer. Whilst systematic reviews and meta-analyses have the potential to provide critical and updated surgical evidence to guide clinical decisions, poorly performed analyses and misinterpretation of such reviews may have a detrimental effect on patient care and outcomes. We present a summary of the critical steps in performing a systematic review and meta-analysis, allowing the surgeon scientist to better interpret and perform their own systematic reviews and meta-analyses. PMID:27683675

  18. Systematic reviews and meta-analyses in spine surgery, neurosurgery and orthopedics: guidelines for the surgeon scientist.

    PubMed

    Phan, Kevin; Mobbs, Ralph J

    2015-12-01

    The research evidence in the realm of surgery is expanding at a rapid pace, and thus corresponds with an increasing need to critically appraise and synthesize the available literature. Particularly in fields such as spine surgery, neurosurgery and orthopedics which traditionally have little Class I randomized clinical data, reviews are important to pool the available evidence on clinical questions which are otherwise difficult to answer. Whilst systematic reviews and meta-analyses have the potential to provide critical and updated surgical evidence to guide clinical decisions, poorly performed analyses and misinterpretation of such reviews may have a detrimental effect on patient care and outcomes. We present a summary of the critical steps in performing a systematic review and meta-analysis, allowing the surgeon scientist to better interpret and perform their own systematic reviews and meta-analyses. PMID:27683675

  19. From anesthetic sponge to nonsinking skull perforator, unitary work neurosurgery in the ancient Arabic and Islamic world.

    PubMed

    Najjar, Jalal

    2010-05-01

    During the Middle Ages, the work of Middle Eastern physicians such as Avicenna, Albucasis, and Rhazes was of paramount importance in guarding the knowledge that had been accumulated throughout history, particularly the contributions of Greek and Roman scholars, and it is well known that the Arabic versions of all of the works by Hippocrates and Galen by Islamic and Arabic scholars are the only copies that have survived until now. In addition to preserving this wealth of knowledge, these Middle Eastern scholars made significant contributions of their own to both medicine and neurosurgery. Many points regarding ancient Arabic and Islamic science need to be discussed and clarified, such as cadaver dissections, anatomic studies, neurosurgical practice and instruments, Arabic translations of Hippocratic and other works, and the influence of the Islamic civilization on Western civilization, especially the Renaissance. PMID:20920948

  20. What is New and Innovative in Emergency Neurosurgery? Emerging Diagnostic Technologies Provide Better Care and Influence Outcome: A Specialist Review

    PubMed Central

    Zisakis, Athanasios K.; Exadaktylos, Aristomenis

    2013-01-01

    The development of emergency medical services and especially neurosurgical emergencies during recent decades has necessitated the development of novel tools. Although the gadgets that the neurosurgeon uses today in emergencies give him important help in diagnosis and treatment, we still need new technology, which has rapidly developed. This review presents the latest diagnostic tools, which offer precious help in everyday emergency neurosurgery practice. New ultrasound devices make the diagnosis of haematomas easier. In stroke, the introduction of noninvasive new gadgets aims to provide better treatment to the patient. Finally, the entire development of computed tomography and progress in radiology have resulted in innovative CT scans and angiographic devices that advance the diagnosis, treatment, and outcome of the patent. The pressure on physicians to be quick and effective and to avoid any misjudgement of the patient has been transferred to the technology, with the emphasis on developing new systems that will provide our patients with a better outcome and quality of life. PMID:24349786

  1. CALCULATED MOLECULAR STRUCTURES AND POTENTIAL ENERGY FUNCTIONS OF PAHS WITH METHYL CROWDING IN THE BAY REGION AND THEIR METABOLITES: COMPARISON TO EXPERIMENTAL STRUCTURES

    EPA Science Inventory

    Abstract Title: Calculated molecular structures and potential energy functions of P AHs with methyl crowding in the bay region and their metabolites: Comparison to experimental structures.

    Abstract:
    PAHs with methyl group substitution near a bay region represent a cl...

  2. CALCULATED MOLECULAR STRUCTURES AND POTENTIAL ENERGY FUNCTIONS OF PAHS WITH METHYL CROWDING IN THE BAY REGION AND THEIR METABOLITES: COMPARISON TO EXPERIMENTAL STRUCTURES

    EPA Science Inventory

    Calculated molecular structures and potential energy functions ofP AHs with methyl crowding in the bay region and their metabolites: Comparison to experimental structures

    PAHs with methyl group substitution near a bay region represent a class of chemicals associated with ...

  3. Comparison of the various methods for the direct calculation of the transmission functions of the 15-micron CO2 band with experimental data

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Various methods for calculating the transmission functions of the 15 micron CO2 band are described. The results of these methods are compared with laboratory measurements. It is found that program P4 provides the best agreement with experimental results on the average.

  4. Experimental and numerical tribological studies of a boundary lubricant functionalized poro-viscoelastic PVA hydrogel in normal contact and sliding.

    PubMed

    Blum, Michelle M; Ovaert, Timothy C

    2012-10-01

    Hydrogels are a cross-linked network of polymers swollen with liquid and have the potential to be used as a synthetic replacement for local defects in load bearing tissues such as articular cartilage. Hydrogels display viscoelastic time dependent behavior, therefore experimental analysis of stresses at the surface and within the gel is difficult to perform. A three-dimensional model of a hydrogel was developed in the commercial finite element software ABAQUS™, implementing a poro-viscoelastic constitutive model along with a contact-dependent flow state and friction conditions. Water content measurements, sliding, and indentation experiments were performed on neat polyvinyl alcohol (PVA), and on low friction boundary lubricant functionalized (BLF-PVA) hydrogels, both manufactured by freeze-thaw processes. Modulus results from the indentation experiments and coefficient of friction values from the sliding experiments were used as material property inputs to the model, while water content was used to calculate initial flow conditions. Tangential force and normal displacement data from a three-dimensional simulation of sliding were compared with the experiments. The tangential force patterns indicated important similarities with the fabricated hydrogels that included an initially high force value due to time dependent deformation followed by a decrease in a stabile value. A similar trend was observed with the normal displacement. These comparisons rendered the model suitable as a representation and were used to analyze the development and propagation of stresses in the immediate surface region. The results showed that in a three-dimensional stress field during sliding, the maximum stress shifted to the surface and rotated closer to the leading edge of contact. This occurred because the stress field becomes dominated by an amplified compressive stress at the leading edge due to the biphasic viscoelastic response of the material during sliding. Also, the complex multi

  5. Essentials of research methods in neurosurgery and allied sciences for research, appraisal and application of scientific information to patient care (Part I).

    PubMed

    Esene, Ignatius N; El-Shehaby, Amr M; Baeesa, Saleh S

    2016-04-01

    Every neurosurgeon ought to be acquainted with the basics of research methods to enhance the comprehension of the research process and critical appraisal procedures of a scientific write-up. This in turn will ensure the appropriate application of scientific knowledge to patient care. Recent publications reveal that a significant proportion of articles published in neurosurgery are mislabeled with dire consequences on the sorting and indexing of evidence. Furthermore, many clinicians report that they feel unqualified to read the medical literature critically hence, it is for this reason that we conducted this review. Herein, we present a simple algorithm to facilitate the comprehension of research methods, as well as elucidate on the anatomy of common study designs in neurosurgery. Illustrative examples are provided when necessary. Understanding research methods and the critical analysis of published reports of clinical investigation is a fundamental skill of the physician to enable the incorporation of new clinical knowledge to practice. PMID:27094519

  6. Management of Subarachnoid Hemorrhage in Two Important Italian Political Leaders: A Paradigm of Ethical and Technological Evolution of Neurosurgery During the Past Half-Century.

    PubMed

    Longatti, Pierluigi; Giombelli, Ermanno; Pavesi, Giacomo; Carteri, Alessandro; Feletti, Alberto

    2016-08-01

    For a curious and extraordinary coincidence, 5 of the 7 most relevant leaders of the Italian Communist Party (Partito Comunista Italiano, which was established in 1921, has been the biggest Communist Party in Western Countries) suffered a cerebral stroke. Cerebrovascular diseases afflicted also Stalin and Lenin, and a number of Presidents of the United States. We present the stories of 2 important Italian political leaders who shared both the leadership role of the major left Italian Party and the dramatic experience of a subarachnoid hemorrhage. Retracing their medical incidents, separated by 50 years of history, we show how a fatal medical disease has become neurosurgical and successfully cured thanks to the advances of neurosurgery, neuroradiology, and hospital organization. A neurologic disease that was disgraceful 50 years ago has lost any disquieting and embarrassing significance in the present time to the light of evolution of vascular neurosurgery.

  7. Factors Affecting The Experimental Line Spread Function (Lsf) Measurement And Modulation Transfer Function (Mtf) Calculation Including Deviation In Characteristic Curve Shape

    NASA Astrophysics Data System (ADS)

    Dahle, Marcia E.; Haus, Arthur G.

    1980-08-01

    The major potential errors in the slit method measurement of the line spread function (LSF) and the modu-lation transfer function (MTF) of radiographic screen-film systems are reviewed. These errors are compared with the potential error introduced in the LSF due to an erroneous representation of the characteristic curve (sensitometric data). If a deviation in the sensitometric data results in a lower average gradient of the characteristic curve, the MTF will show higher resolution capabilities.

  8. Comparative catfish macrophage function in families expressing high and low survivor phenotype following experimental challenge with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two channel catfish families were identified as displaying a high (>90%) or low (<10%) survival phenotype in repeated experimental challenge with Edwardsiella ictaluri. In order to gain understanding of the biological basis of these phenotypes, primary macrophages were prepared from head kidney tiss...

  9. The effect of experimental low back pain on lumbar muscle activity in people with a history of clinical low back pain: a muscle functional MRI study.

    PubMed

    Danneels, Lieven; Cagnie, Barbara; D'hooge, Roseline; De Deene, Yves; Crombez, Geert; Vanderstraeten, Guy; Parlevliet, Thierry; Van Oosterwijck, Jessica

    2016-02-01

    In people with a history of low back pain (LBP), structural and functional alterations have been observed at several peripheral and central levels of the sensorimotor pathway. These existing alterations might interact with the way the sensorimotor system responds to pain. We examined this assumption by evaluating the lumbar motor responses to experimental nociceptive input of 15 participants during remission of unilateral recurrent LBP. Quantitative T2 images (muscle functional MRI) were taken bilaterally of multifidus, erector spinae, and psoas at several segmental levels (L3 upper and L4 upper and lower endplate) and during several conditions: 1) at rest, 2) upon trunk-extension exercise without pain, and 3) upon trunk-extension exercise with experimental induced pain at the clinical pain-side (1.5-ml intramuscular hypertonic saline injections in erector spinae). Following experimental pain induction, muscle activity levels similarly reduced for all three muscles, on both painful and nonpainful sides, and at multiple segmental levels (P = 0.038). Pain intensity and localization from experimental LBP were similar as during recalled clinical LBP episodes. In conclusion, unilateral and unisegmental experimental LBP exerts a generalized and widespread decrease in lumbar muscle activity during remission of recurrent LBP. This muscle response is consistent with previous observed patterns in healthy people subjected to the same experimental pain paradigm. It is striking that similar inhibitory patterns in response to pain could be observed, despite the presence of preexisting alterations in the lumbar musculature during remission of recurrent LBP. These results suggest that motor output can modify along the course of recurrent LBP.

  10. Correlation of CT-based regional cardiac function (SQUEEZ) with myocardial strain calculated from tagged MRI: an experimental study.

    PubMed

    Pourmorteza, Amir; Chen, Marcus Y; van der Pals, Jesper; Arai, Andrew E; McVeigh, Elliot R

    2016-05-01

    The objective of this study was to investigate the correlation between local myocardial function estimates from CT and myocardial strain from tagged MRI in the same heart. Accurate detection of regional myocardial dysfunction can be an important finding in the diagnosis of functionally significant coronary artery disease. Tagged MRI is currently a reference standard for noninvasive regional myocardial function analysis; however, it has practical drawbacks. We have developed a CT imaging protocol and automated image analysis algorithm for estimating regional cardiac function from a few heartbeats. This method tracks the motion of the left ventricular (LV) endocardial surface to produce local function maps: we call the method Stretch Quantification of Endocardial Engraved Zones (SQUEEZ). Myocardial infarction was created by ligation of the left anterior descending coronary artery for 2 h followed by reperfusion in canine models. Tagged and cine MRI scans were performed during the reperfusion phase and first-pass contrast enhanced CT scans were acquired. The average delay between the CT and MRI scans was <1 h. Circumferential myocardial strain (Ecc) was calculated from the tagged MRI data. The agreement between peak systolic Ecc and SQUEEZ was investigated in 162 segments in the 9 hearts. Linear regression and Bland-Altman analysis was used to assess the correlation between the two metrics of local LV function. The results show good agreement between SQUEEZ and Ecc: (r = 0.71, slope = 0.78, p < 0.001). Furthermore, Bland-Altman showed a small bias of -0.02 with 95 % confidence interval of 0.1, and standard deviation of 0.05 representing ~6.5 % of the dynamic range of LV function. The good agreement between the estimates of local myocardial function obtained from CT SQUEEZ and tagged MRI provides encouragement to investigate the use of SQUEEZ for measuring regional cardiac function at a low clinical dose in humans.

  11. Reconstruction of the experimental autocorrelation function and determination of the parameters of the statistical roughness of a surface from laser radiation scattering in an integrated-optical waveguide

    SciTech Connect

    Egorov, Aleksei A

    2003-04-30

    The possibility of using the waveguide scattering of laser radiation for obtaining information on the statistical properties of irregularities from the noisy data obtained in the far-field zone is shown. A complex algorithm for reconstructing the experimental autocorrelation function of the surface roughness of an integrated-optical waveguide substrate is described. This algorithm is based on a combination of the classical regularisation and quasi-optimal filtering. (waveguides)

  12. [Functional-morphologic aspects of changes of mucosal gingiva microcirculatory bed vessels in experimental gingivitis against the background of hypercholesterolemia].

    PubMed

    Maglakelidze, N; Galogre, A; Tsagareli, Z

    2005-04-01

    The study of mucosal gingiva microcirculatory bed in conditions modeling the change of vascular wall permeability that promotes cell migration and plasmorrhagia. The experiments were made on 3 groups of chinchilla rabbits--body weight 1,7-2,5 kg: I-experimental gingivitis (10 animals); II-experimental hypercholesterolemia--the rabbits received aterogenic diet (0,3 g/kg of cholesterol) (10 animals). Two month after the aterogenic diet, gingivitis was modelled against the background of hypercholesterolemia (control for group II). IV-series--conditionally "normal"--5 rabbits. The light-optic and electron microscopic studies have revealed significant changes in extracellular matrix and gingiva mucous cells as well as in microcirculatory bed components in hypercholesterolemia. Hypercholesterolemia damages endotheliocytes, subendothelial zone, basal membrane abd changes permeability. The contact of lymphocytes and plasmocytes with the vascular wall confirms the trigger role of the vascular factor in damaging of periodontal complex.

  13. Subchronic Toluene Exposure alters Retinal Function in Long Evans Rats: Experimental</