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Sample records for intracranial ring enhancing

  1. Intracranial hypertension as the primary symptom of gastric signet-ring cell carcinoma

    PubMed Central

    Pu, Jiali; Xu, Lingjia; Yin, Xinzhen; Zhang, Baorong

    2016-01-01

    Abstract Background: Intracranial hypertension (IH) is a neurological disorder characterized by increased intracranial pressure. It is a poorly understood syndrome that most commonly manifests nonspecific symptoms such as stroke-like headache, vision changes, nausea, vomiting, and papilledema. IH has been reported in young cancer patients but never in association with gastric signet-ring cell carcinoma. Methods: Here, we discuss the case of an 18-year-old girl with gastric signet-ring cell carcinoma in which IH was the primary symptom accompanied by the even rarer symptom of cutaneous metastases. We also present a review of the relevant literature. The patient experienced frequent headaches, vomiting, and blurred vision but showed no abnormal findings on cranial imaging studies. Further examination showed multiple skin nodules on the abdomen. Then pathological and immunohistochemical examination of gastroscopic specimens and the biopsied subcutaneous nodules were done. Results: Pathological and immunohistochemical examination of gastroscopic specimens and the biopsied subcutaneous nodules confirmed gastric signet-ring cell carcinoma with skin metastases. Conclusion: To our knowledge, this is the first reported case of gastric signet-ring cell carcinoma primarily presenting IH and accompanied by subcutaneous metastases. This case emphasizes the importance of excluding malignancy from the differential diagnosis of IH. PMID:27583897

  2. Spinal Cord Ring Enhancement in Multiple Sclerosis

    PubMed Central

    Klawiter, Eric C; Benzinger, Tammie; Roy, Abhik; Naismith, Robert T; Parks, Becky J; Cross, Anne H

    2010-01-01

    Objective Describe the clinical and imaging characteristics of spinal cord ring enhancement in multiple sclerosis (MS). Design Clinical case series. Setting Academic referral center. Patients Twenty MS subjects with spinal cord ring enhancement were retrospectively identified from 322 cervical and thoracic spinal cord MRI studies over a 3 year period. Main Outcome Measures Demographics, disability, pattern of enhancement on spinal cord imaging, and concomitant brain magnetic resonance imaging (MRI) were determined. Results Ring enhancement was seen in 20 subjects with spinal cord enhancement, most commonly in the cervical cord. Incomplete or ‘open’ ring enhancement was the dominant pattern in 19 of 20 (95%) subjects. Concurrent ring enhancing brain lesions were present in 40% of subjects. At the time of the MRI, the Expanded Disability Status Scale (EDSS) ranged from 1.0–7.0 (median 3.0). Conclusion Ring enhancement is not an uncommon pattern for MS spinal cord lesions, occurring with a prevalence of 6.2% (20/322). The most common pattern was incomplete ring enhancement in the cervical spinal cord. Recognition of this pattern may improve and expedite the diagnosis of MS and preclude need for invasive diagnostic interventions. PMID:21060017

  3. Importance of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Various Intracranial Pathologic Conditions

    PubMed Central

    Lee, Eun Kyoung; Kim, Sungwon; Lee, Yong Seok

    2016-01-01

    Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions. PMID:26798225

  4. Intracranial Hypertension as an Acute Complication of Aseptic Meningoencephalitis with Leptomeningeal Contrast Enhancement on FLAIR MRI

    PubMed Central

    Wolf, Marc E.; Eisele, Philipp; Schweizer, Yvonne; Alonso, Angelika; Gass, Achim; Hennerici, Michael G.; Szabo, Kristina

    2016-01-01

    We report a case of a 19-year-old woman who developed intracranial hypertension as an unusual clinical complication of severe aseptic meningoencephalitis probably due to a diminished cerebrospinal fluid reabsorption capacity or leptomeningeal transudation as a consequence of blood-brain barrier dysfunction. These severe inflammatory changes were accompanied by prominent leptomeningeal contrast enhancement best visualized on fluid-attenuated inversion recovery magnetic resonance imaging. In such a prolonged course, a continuous lumbar drainage might be a temporary option to provide rapid symptom relief to the patient. PMID:26889150

  5. Intracranial Hypertension as an Acute Complication of Aseptic Meningoencephalitis with Leptomeningeal Contrast Enhancement on FLAIR MRI.

    PubMed

    Wolf, Marc E; Eisele, Philipp; Schweizer, Yvonne; Alonso, Angelika; Gass, Achim; Hennerici, Michael G; Szabo, Kristina

    2016-01-01

    We report a case of a 19-year-old woman who developed intracranial hypertension as an unusual clinical complication of severe aseptic meningoencephalitis probably due to a diminished cerebrospinal fluid reabsorption capacity or leptomeningeal transudation as a consequence of blood-brain barrier dysfunction. These severe inflammatory changes were accompanied by prominent leptomeningeal contrast enhancement best visualized on fluid-attenuated inversion recovery magnetic resonance imaging. In such a prolonged course, a continuous lumbar drainage might be a temporary option to provide rapid symptom relief to the patient. PMID:26889150

  6. Estradiol lowers intracranial self-stimulation thresholds and enhances cocaine facilitation of intracranial self-stimulation in rats.

    PubMed

    Galankin, Timofey; Shekunova, Elena; Zvartau, Edwin

    2010-11-01

    Women initiate cocaine use at a younger age and have more complications (e.g., higher rates of major or minor depression) related to cocaine use than men. It has been proposed that estrogens play an important role in these sex differences. The addictive potential of psychoactive drugs can be measured in rats via a rewarding intracranial self-stimulation (ICSS) procedure. The rate-independent method of ICSS allows researchers to assess the "pure" rewarding effect of cocaine without influence of nonspecific motor reactions. The present study aimed to estimate effects of estradiol and a combination of estradiol and cocaine on ICSS in ovariectomized female rats. 17-β-estradiol (5μg/animal/day, 2 days) produced a long-lasting gradual lowering of the thresholds for ICSS. The ability of estradiol to decrease thresholds for ICSS has never been shown previously. Combination of 17-β-estradiol and cocaine (5.0mg/kg, 5 days) produced a greater effect on ICSS thresholds than the effect of either compound alone. No tolerance or sensitization to cocaine developed during the study. Present findings suggest estradiol increases sensitivity of the brain reward system in rats, which may have an important implication in understanding sex differences in cocaine effects. PMID:20736014

  7. Convection-enhanced delivery of camptothecin-loaded polymer nanoparticles for treatment of intracranial tumors

    PubMed Central

    Sawyer, Andrew J.; Saucier-Sawyer, Jennifer K.; Booth, Carmen J.; Liu, Jie; Patel, Toral; Piepmeier, Joseph M.

    2011-01-01

    Direct delivery of chemotherapy agents to the brain via degradable polymer delivery systems—such as Gliadel®—is a clinically proven method for treatment of glioblastoma multiforme, but there are important limitations with the current technology—including the requirement for surgery, profound local tissue toxicity, and limitations in diffusional penetration of agents—that limit its application and effectiveness. Here, we demonstrate another technique for direct, controlled delivery of chemotherapy to the brain that provides therapeutic benefit with fewer limitations. In our new approach, camptothecin (CPT)-loaded poly(lacticco-glycolic acid) (PLGA) nanoparticles are infused via convection-enhanced delivery (CED) to a stereotactically defined location in the brain, allowing simultaneous control of location, spread, and duration of drug release. To test this approach, CPT-PLGA nanoparticles (~100 nm in diameter) were synthesized with 25% drug loading. When these nanoparticles were incubated in culture with 9L gliosarcoma cells, the IC50 of CPT-PLGA nanoparticles was 0.04 µM, compared to 0.3 µM for CPT alone. CPT-PLGA nanoparticles stereotactically delivered by CED improved survival in rats with intracranial 9L tumors: the median survival for rats treated with CPT-PLGA nanoparticles (22 days) was significantly longer than unloaded nanoparticles (15 days) and free CPT infusion (17 days). CPT-PLGA nanoparticle treatment also produced significantly more long-term survivors (30% of animals were free of disease at 60 days) than any other treatment. CPT was present in tissues harvested up to 53 days post-infusion, indicating prolonged residence at the local site of administration. These are the first results to demonstrate the effectiveness of combining polymer-controlled release nanoparticles with CED in treating fatal intracranial tumors. PMID:21691426

  8. Assessment of reinforcement enhancing effects of toluene vapor and nitrous oxide in intracranial self-stimulation

    PubMed Central

    Tracy, Matthew E.; Slavova-Hernandez, Galina G.; Shelton, Keith L.

    2013-01-01

    Rationale Despite widespread abuse there are few validated methods to study the rewarding effects of inhalants. One model that that may have utility for this purpose is intracranial self-stimulation (ICSS). Objectives We wished to compare and contrast the ICSS reward-facilitating effects of abused inhalants to other classes of abused drugs. Compounds were examined using two different ICSS procedures in mice to determine the generality of each drug's effects on ICSS and the sensitivity of the procedures. Methods Male C57BL/6J mice with electrodes implanted in the medial forebrain bundle were trained under a three component rate-frequency as well as a progressive ratio (PR) ICSS procedure. The effects of nitrous oxide, toluene vapor, cocaine and diazepam on ICSS were then examined. Results Concentrations of 1360-2900 ppm inhaled toluene vapor significantly facilitated ICSS in the rate frequency procedure and 1360 ppm increased PR breakpoint. A concentration of 40% nitrous oxide facilitated ICSS in the rate-frequency procedure but reduced PR breakpoint. Doses of 3-18 mg/kg cocaine facilitated ICSS in the rate frequency procedure and 10 and 18 mg/kg increased PR breakpoint. Doses of 1 and 3 mg/kg diazepam facilitated ICSS in the rate frequency procedure and 3 mg/kg increased PR breakpoint. Conclusions The reinforcement facilitating effect of toluene in ICSS is at least as great as diazepam. In contrast, nitrous oxide weakly enhances ICSS in only the rate frequency procedure. The data suggest that the rate frequency procedure may be more sensitive than the PR schedule to the reward facilitating effects of abused inhalants. PMID:24186077

  9. Loop 2 of Ophiophagus hannah toxin b binds with neuronal nicotinic acetylcholine receptors and enhances intracranial drug delivery.

    PubMed

    Zhan, Changyou; Yan, Zhiqiang; Xie, Cao; Lu, Weiyue

    2010-12-01

    Three-finger snake neurotoxins have been widely investigated for their high binding affinities with nicotinic acetylcholine receptors (nAChRs), which are widely expressed in the central nervous system including the blood-brain barrier and thus mediate intracranial drug delivery. The loop 2 segments of three-finger snake neurotoxins are considered as the binding domain with nAChRs, and thus, they may have the potential to enhance drug or drug delivery system intracranial transport. In the present work, binding of the synthetic peptides to the neuronal nAChRs was assessed by measuring their ability to inhibit the binding of (125)I-α-bungarotoxin to the receptor. The loop 2 segment of Ophiophagus hannah toxin b (KC2S) showed high binding affinity, and the competitive binding IC(50) value was 32.51 nM. Furthermore, the brain targeting efficiency of KC2S had been investigated in vitro and in vivo. The specific uptake by brain capillary endothelial cells (BCECs) demonstrated that KC2S could be endocytosized after binding with nAChRs. In vivo, the qualitative and quantitative biodistribution results of fluorescent dyes (DiR or coumarin-6) indicated that KC2S modified poly(ethylene glycol)-poly(lactic acid) micelles (KC2S-PEG-PLA micelles) could enhance intracranial drug delivery. Furthermore, intravenous treatment with paclitaxel-encapsulated KC2S-PEG-PLA micelles (KC2S-PEG-PLA-PTX micelles) afforded robust inhibition of intracranial glioblastoma. The median survival time of KC2S-PEG-PLA-PTX-micelle-treated mice (47.5 days) was significantly longer than that of mice treated by mPEG-PLA-PTX micelles (41.5 days), Taxol (38.5 days), or saline (34 days). Compared with the short peptide derived from rabies virus glycoprotein (RVG29) that has been previously reported as an excellent brain targeting ligand, KC2S has a similar binding affinity with neuronal nAChRs but fewer amino acid residues. Thus, we concluded that the loop 2 segment of Ophiophagus hannah toxin b could bind

  10. Enhanced Discharge Performance in a Ring Cusp Plasma Source

    NASA Technical Reports Server (NTRS)

    Foster, John E.; Patterson, Michael J.

    2000-01-01

    There is a need for a lightweight, low power ion thruster for space science missions. Such an ion thruster is under development at NASA Glenn Research Center. In an effort to better understand the discharge performance of this thruster, a thruster discharge chamber with an anode containing electrically isolated electrodes at the cusps was fabricated and tested. Characteristics of this ring cusp ion discharge were measured without ion beam extraction. Discharge current was measured at collection electrodes located at the magnetic cusps and at the anode body itself. Discharge performance and plasma properties were measured as a function of power, which was varied between 20 and 50 W. It was found that ion production costs decreased by as much as 20 percent when the two most downstream cusp electrodes were allowed to float. Floating the electrodes did not give rise to a significant increase in discharge power even though the plasma density increased markedly. The improved performance is attributed to enhanced electron containment.

  11. Why a standard contrast-enhanced MRI might be useful in intracranial internal carotid artery stenosis.

    PubMed

    Oeinck, Maximilian; Rozeik, Christoph; Wattchow, Jens; Meckel, Stephan; Schlageter, Manuel; Beeskow, Christel; Reinhard, Matthias

    2016-06-01

    In patients with ischemic stroke of unknown cause cerebral vasculitis is a rare but relevant differential diagnosis, especially when signs of intracranial artery stenosis are found and laboratory findings show systemic inflammation. In such cases, high-resolution T1w vessel wall magnetic resonance imaging (MRI; 'black blood' technique) at 3 T is preferentially performed, but may not be available in every hospital. We report a case of an 84-year-old man with right hemispheric transient ischemic attack and signs of distal occlusion in the right internal carotid artery (ICA) in duplex sonography. Standard MRI with contrast agent pointed the way to the correct diagnosis since it showed an intramural contrast uptake in the right ICA and both vertebral arteries. Temporal artery biopsy confirmed the suspected diagnosis of a giant cell arteritis and dedicated vessel wall MRI performed later supported the suspected intracranial large artery inflammation. Our case also shows that early diagnosis and immunosuppressive therapy may not always prevent disease progression, as our patient suffered several infarcts in the left middle cerebral artery (MCA) territory with consecutive high-grade hemiparesis of the right side within the following four months. PMID:26988083

  12. Enhanced Intracranial Microdialysis by Reduction of Traumatic Penetration Injury at the Probe Track.

    PubMed

    Varner, Erika L; Jaquins-Gerstl, Andrea; Michael, Adrian C

    2016-06-15

    Microdialysis provides deep insight into chemical neuroscience by enabling in vivo intracranial chemical monitoring. Nevertheless, implanting a microdialysis probe causes a traumatic penetration injury (TPI) of brain tissue at the probe track. The TPI, which is clearly documented by voltammetry and histochemical imaging, is a drawback because it perturbs the exact tissue from which the brain dialysate samples are derived. Our goal is to reduce, if not eventually eliminate, the TPI and its detrimental effects on neurochemical monitoring. Here, we demonstrate that combining a 5-day wait period after probe implantation with the continuous retrodialysis of a low-micromolar concentration of dexamethasone vastly reduces the TPI. Our approach to reducing the TPI reinstates normal evoked dopamine release activity in the tissue adjacent to the microdialysis probe, brings evoked dopamine release at the probe outlet into quantitative agreement with evoked dopamine release next to the probe, reinstates normal immunoreactivity for tyrosine hydroxylase and the dopamine transporter near the probe track, and greatly suppresses glial activation and scaring near the probe track. This reduction of the TPI and reinstatement of normal evoked dopamine release activity adjacent to the probe track appears to be due to dexamethasone's anti-inflammatory actions. PMID:27003503

  13. Quasi-isochronous storage ring for enhanced FEL performance

    SciTech Connect

    Ohgaki, H.; Robin, D.; Yamazaki, Y.

    1995-08-01

    A compact storage ring is designed to be used as a driver for an FEL. This ring can be operated very close to zero momentum compaction factor ({alpha}) to increase the electron density and thus the gain of the FEL. In order to control {alpha} with zero dispersion in the straight sections the authors use an inverted dipole located between the bending magnets and 4-families of quadrupoles. By using 3-families of sextupoles they can control the 2 transverse chromaticities and 2nd order momentum compaction. They find that the ring has sufficient dynamic aperture for good performance.

  14. Primary Intracranial Leptomeningeal Melanomatosis

    PubMed Central

    Kim, Do-Hyoung; Lee, Chae-Heuck; Joo, Mee

    2015-01-01

    Primary intracranial malignant melanoma is a very rare and highly aggressive tumor with poor prognosis. A 66-year-old female patient presented a headache that had been slowly progressing for several months. A large benign pigmented skin lesion was found on her back. A brain MRI showed multiple linear signal changes with branching pattern and strong enhancement in the temporal lobe. The cytological and immunohiostochemical cerebrospinal fluid examination confirmed malignant melanoma. A biopsy confirmed that the pigmented skin lesion on the back and the conjunctiva were benign nevi. We report a case of primary intracranial malignant melanoma and review relevant literatures. PMID:26819692

  15. Super defect inside photonic crystal ring resonator to enhance Q factor

    NASA Astrophysics Data System (ADS)

    Sreenivasulu, Tupakula; Kolli, Venkateswara Rao; Tarimala, Badrinarayana; Hegde, Gopalkrishna; Sangineni, Mohan; Talabattula, Srinivas

    2016-03-01

    A design is proposed to enhance the quality factor of a photonic crystal ring resonator. A super defect is employed inside the ring resonator, which consists of variation of hole dimensions inside the ring resonator in such a way that the radiation field components of the resonant nanocavity are forced to get cancelled in order to reduce radiation loss. After this forced cancellation, the improved Q factor is calculated as 18,000. This photonic crystal ring resonator can be used for sensing applications like force sensing, pressure sensing, biochemical sensing, and communication applications like demultiplexing.

  16. Rings

    SciTech Connect

    Davis, R.L.

    1989-01-01

    The essence of vortex physics is that at certain low-energy scales elementary excitations of a point particle theory can behave like strings rather than particles. Vortices are the resulting string-like solutions; their thickness sets the distance scale beyond which physics is string-like rather than particle-like. String degrees of freedom are massless in the sense that excitations on a string can have an arbitrarily low frequency. Non-string degrees of freedom correspond to massive particles and are absent from the low energy spectrum. This article considers only field theories with vortices at low energies. The possible existence of a class of solitons in these vortex theories will be discussed. They are vortex rings: they are localized and finite in energy, and able to carry the quantum numbers of point particles. Rings are thus particle-like solutions of a vortex theory, which is itself a limit of a point particle field theory.

  17. Enhanced ring lasers: a new measurement tool for Earth sciences

    SciTech Connect

    Schreiber, K U; Kluegel, T; Wells, J.-P.; Holdaway, J; Gebauer, A; Velikoseltsev, A

    2012-11-30

    We report the progress in the technology of fabrication of large ring lasers that has resulted in an increase in instrumental rotation sensitivity by as much as a factor of 3, to {delta}{Omega} = 1.2 Multiplication-Sign 10{sup -11} rad s{sup -1} Hz{sup -1/2}, which makes the domain of changes in the angular velocity of Earth's rotation, {Delta}{Omega}/{Omega} Almost-Equal-To 10{sup -9}, accessible to a local rotation sensor. New studies show that the largest contribution to the observed deviation in sensor performance with respect to the computed shot noise limit is caused by the micro-seismic background activity of the Earth. Our efforts have been concentrated on the improvement of sensor stability, including correction of drift effects, which are caused by the aging of the laser gas, fixing scale factor instabilities induced by atmospheric pressure variations, and minimising the temperature variations resulting from corresponding adiabatic expansion and compression of the local air around the instrument. To achieve this, we have recently introduced a pressure-stabilising vessel with dimensions slightly larger than the ring laser apparatus, such that it encloses the entire structure. By monitoring the optical frequency in the ring laser cavity continuously and stabilising the scale factor in a closed loop system with the pressure-stabilising vessel, it has become possible to extend the range of sensor stability from the short term (1 - 3 days) to well into the mid-term regime (>40 days), and possibly even well beyond that. Once a sufficiently long timeseries of the ring laser data has been recorded, we will be able to define the range of temporal stability in more detail. The extension of the regime of stability gives access to geophysical signals at frequencies substantially lower than previously observable with ring lasers. (laser applications and other topics in quantum electronics)

  18. Intracranial germinoma

    PubMed Central

    Reddy, Manoj P.; Doughty, Kyle E.; Armstrong, Danielle; Melguizo-Gavilanes, Isaac; Cheek, Brennen S.; Opatowsky, Michael J.

    2015-01-01

    Pineal region tumors make up less than 1% of all intracranial neoplasms, with the majority being of germ cell origin. We describe the diagnostic evaluation and treatment of a patient presenting with neurological deficits who was found to have a germinoma of the pineal gland. PMID:25552796

  19. Optical Peaking Enhancement in High-Speed Ring Modulators

    PubMed Central

    Müller, J.; Merget, F.; Azadeh, S. Sharif; Hauck, J.; García, S. Romero; Shen, B.; Witzens, J.

    2014-01-01

    Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments. PMID:25209255

  20. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances.

    PubMed

    Zhou, Yong Jin; Xiao, Qian Xun; Yang, Bao Jia

    2015-01-01

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform. PMID:26420668

  1. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances

    PubMed Central

    Zhou, Yong Jin; Xiao, Qian Xun; Jia Yang, Bao

    2015-01-01

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform. PMID:26420668

  2. Thermo-optical tuning of cascaded double micro-ring resonators for dynamic range enhancement

    NASA Astrophysics Data System (ADS)

    Prasad, Prashanth R.; Selvaraja, Shankar K.; Varma, Manoj M.

    2016-03-01

    We report on a silicon-photonic cascaded microring sensor with thermo-optic tuning for extension of detection range. Cascaded microring resonators have been used to realize refractive index sensors with high sensitivity in the intensity detection mode. In this configuration, one ring is used to probe analyte while the other ring (called filter) is used for spectrum overlap measurement. A significant drawback of this configuration is decreased range of detection. We overcome this problem by thermo-optically tuning the spectrum the filter ring to track the position of maximum overlap, as the spectrum of the probing ring undergoes shift. Using this peak tracking method, we have experimentally demonstrated range enhancement by a factor of 7.8, compared to the intensity detection scheme. This method can use a broadband source for operation, and has a potential for development of low cost, point of care biomedical applications.

  3. Vessel-selective, non-contrast enhanced, time-resolved MR angiography with vessel-selective arterial spin labeling technique (CINEMA-SELECT) in intracranial arteries.

    PubMed

    Nakamura, Masanobu; Yoneyama, Masami; Tabuchi, Takashi; Takemura, Atsushi; Obara, Makoto; Tatsuno, Satoshi; Sawano, Seishi

    2013-07-01

    We demonstrate the feasibility of the vessel-selective, non-contrast, time-resolved magnetic resonance angiography (MRA) technique, "contrast inherent inflow enhanced multi-phase angiography combining vessel-selective arterial spin labeling technique (CINEMA-SELECT)". This sequence consists of two major techniques: pulsed star labeling of arterial regions (PULSAR) and Look-Locker sampling. We hypothesize that this technique allows selective labeling of single intracranial arteries, consisting of high-resolution four-dimensional data with a wide coverage of the brain. In this study, a new vessel-selective, time-resolved angiographic technique is demonstrated that can produce individual angiograms non-invasively by labeling the principal arterial vessels proximal to the circle of Willis. Clear vessel delineation is achieved, and the separation of the three vessels is evident in healthy volunteers. This technique could play an important role in the assessment of the structure and hemodynamics of intracranial arteries without the use of contrast agents. PMID:23475783

  4. Enhancing the Expressiveness of Fingers: Multi-touch Ring Menus for Everyday Applications

    NASA Astrophysics Data System (ADS)

    Kammer, Dietrich; Lamack, Frank; Groh, Rainer

    In the future, environments equipped with interaction surfaces sensitive to touch input will be a key factor to enable ambient intelligence. The user's fingers become input devices, allowing simple and intuitive interaction, like the manipulation of digital objects. However, people are used to everyday applications offering a wide variety of menu choices. We evaluate ring menus to enhance the expressiveness of finger interaction on multi-touch devices. Applicability and limits of ring menus are discussed with regard to our implementation by means of a preliminary user study.

  5. The Plasma Physics Processes that Drive Ring Current Enhancements during Geomagnetic Storms and Substorms

    NASA Astrophysics Data System (ADS)

    Cash, Michele Diane

    Geomagnetic storms result when energetic particles of solar and ionospheric origin fill Earth's inner magnetosphere and create a strong westward current, known as the ring current. This dissertation presents results from investigating the plasma dynamics that contribute to the development of Earth's ring current from ionospheric outflow of H+ and O+ ions, and the role of ring current enhancements in the generation of geomagnetic storms and substorms. Modeling was carried via a combined multifluid and particle approach, which enables us to resolve the small-scale dynamics that are key to particle energization within the context of the global magnetosphere. The results presented in this dissertation substantially contribute to our understanding of the development and composition of the ring current during geomagnetic storms and substorms, and offer insight into the ionospheric sources regions for ring current ions, as well as the processes through which these particles are energized, injected, and trapped within the inner magnetosphere. This thesis presents results that show how small-scale particle dynamics within the current sheet, boundary layers, and reconnection regions drive the acceleration of ring current particles within the larger global context of the magnetosphere. Small-scale structures within the magnetotail are shown to be more important in determining when particles are accelerated than the time after particles are initialized in the ionosphere. It is also found that after a period of southward IMF, in which particle energization is observed, a northerly turning of the IMF is necessary in order to trap energetic particles in orbit around the Earth and form a symmetric ring current. Asymmetries in the acceleration mechanisms between ionospheric H+ and O + ions were observed with oxygen ions convecting duskward according to the cross-tail current and gaining more energy than protons, which moved earthward on reconnecting field lines and were accelerated

  6. Increased intracranial pressure

    MedlinePlus

    Increased intracranial pressure is a rise in the pressure inside the skull that can result from or cause brain injury. ... Increased intracranial pressure can be due to a rise in pressure of the cerebrospinal fluid. This is ...

  7. Intracranial Vascular Treatments

    MedlinePlus

    ... most commonly used in the treatment of intracranial aneurysms. Mechanical retrievers/aspiration systems: used to remove clots ... passageway between an artery and a vein. intracranial aneurysms, a ballooning out of the wall of an ...

  8. On-chip tunable dispersion in a ring laser gyroscope for enhanced rotation sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Liu, Jiaming; Lin, Jian; Li, Wenxiu; Xue, Xia; Huang, Anping; Xiao, Zhisong

    2016-05-01

    A gyroscope structure with tailored local dispersion profile to enhance sensitivity is proposed, which uses lithium niobate (LiNbO3) thin film as the on-chip material of gyroscope's resonator. A Mach-Zehnder interferometer (MZI) structure as a coupler, which induces a different reference phase shift in each arm, is inserted into the position between ring resonator and output bus waveguide. Through modulating reference phase shift in MZI, theoretical rotation sensitivity enhancement as large as one order of magnitude is presented.

  9. A Case Report of Listeria monocytogenes Abscesses Presenting as Cortically Predominant Ring-Enhancing Lesions

    PubMed Central

    DeJesus-Alvelo, Indira; Merenda, Amedeo

    2015-01-01

    Introduction Listeria monocytogenes, a common cause of bacterial meningitis, rarely involves the central nervous system (CNS) in the form of multiple cerebral ring-enhancing lesions. Methods An 81-year-old woman with rapidly progressive decline in her mental status in the setting of multiple cortically predominant ring-enhancing lesions was transferred to our institution. A mild upper respiratory tract infection and diarrhea symptoms preceded the mental status deterioration. Her past medical history is significant for type 2 diabetes mellitus. In light of the patient's age, the presence of hyponatremia and the history of diabetes mellitus, the empiric antimicrobial treatment was modified to include ampicillin, meropenem, vancomycin, voriconazole and pyrimethamine/sulfadiazine to prevent opportunistic infections. Intravenous dexamethasone was added due to significant perilesional vasogenic edema. Results The patient presented with stupor, but neither fever nor leukocytosis. CSF results were significant only for a mildly elevated protein level. The report of a repeat brain MRI was as follows: large areas of high FLAIR signals and tubular/lobulated/ring enhacement in bifrontal regions with a smaller focus in the left anterior midbrain, indicating for underlying multicentric glioma or multicentric primary CNS lymphoma. A brain biopsy, however, revealed an early abscess formation caused by a L. monocytogenes infection. Conclusion A high index of suspicion in patients with risk factors for this infection is key to ensure the timely initiation of appropriate empirical antibiotic therapy in the setting of cerebral ring-enhancing lesions. Intravenous ampicillin is the treatment of choice, but meropenem represents a valid alternative. PMID:26034484

  10. Access of energetic particles to storm time ring current through enhanced radial diffusion

    SciTech Connect

    Lyons, L.R.; Schulz, M. )

    1989-05-01

    Magnetic storms are distinguishable from other periods of geomagnetic activity by the injection of trapped electrons and ions to the 2{approx lt} L {approx lt} 4 region. It has been proposed previously that this injection results from an inward displacement of the preexisting trapped-particle population by enhanced storm time electric fields. However, high-energy ({approx gt} 40 keV) ring-current particles have drift periods that are typically shorter than the time of the main-phase development, and so the direct radial transport of these particles is restricted. The authors propose here that the transport of {approx gt} 40 keV particles into the storm time ring current can result from enhanced stochastic radial transport driven by fluctuating electric fields during a storm's main phase. They estimate the effects of such electric fields by applying radial-diffusion theory, assuming a preexisting trapped-particle population as the initial conditions, and they demonstrate the feasibility of explaining observed flux increases of {approx gt} 40-keV particles at L{approx lt} 4 by enhanced radial diffusion. It is necessary that new particles be injected near the outer boundary of the trapping region so as to maintain the fluxes there as an outer boundary condition, and they estimate that the {approx gt} 40-keV portion of the storm time ring current at L {approximately} 3 consists of about 50% preexisting and about 50% new particles. They thus find that formation of the storm time ring current may be explainable via a combination of direct radial transport at energies {approx lt} 40 keV and diffusive radial transport at higher energies.

  11. Contrast-Enhanced and Time-of-Flight MR Angiographic Assessment of Endovascular Coiled Intracranial Aneurysms at 1.5 T

    PubMed Central

    Levent, Akin; Yuce, Ihsan; Eren, Suat; Ozyigit, Omer; Kantarci, Mecit

    2014-01-01

    Summary This study evaluated contrast-enhanced magnetic resonance angiography (CE-MRA) and three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) through comparisons with digital subtraction angiography (DSA) for the follow-up of intracranial aneurysms treated with detachable coils. Sixty-seven patients with 79 aneurysms underwent 3D-TOF-MRA, CE-MRA, and catheter angiography one year after coiling. Two independent observers classified recanalization status on images as neck or body remnant or no recanalization. For 3D-TOF-MRA and CE-MRA, the intermodality agreement, interobserver agreement, and correlation with angiography were assessed. Sixty-seven patients with 79 coiled aneurysms agreed to participate in the study. Three aneurysms could not be detected on 3D-TOF-MRA, so they were excluded from this study. Interobserver agreement was very good for 3D-TOF-MRA and CE-MRA (kappa (κ): 0.87, 0.94, respectively). Correlation of TOF-MRA with angiography was good (κ: 0.76). Correlation of CE-MRA with angiography was excellent (κ: 0.91). The sensitivity and specificity of TOF-MRA were 92% and 98%, respectively. The sensitivity and specificity of CE-MRA were 96% and 98%, respectively. After selective embolization of intracranial aneurysms, CE-MRA is useful and comparable to DSA in the assessment of aneurysmal recanalization. Agreement with the gold standard is stronger with CE-MRA than with 3D-TOF-MRA. PMID:25496678

  12. Ectopic intracranial germinoma.

    PubMed

    Shankar, Samantha; Wu, Xiao; Kalra, Vivek B; Huttner, Anita J; Malhotra, Ajay

    2016-09-01

    Intracranial ectopic germinomas are often associated with synchronous midline disease. Germinomas involving the corpus callosum are exceedingly rare. The reported imaging appearance is not as varied as one might expect and a review of the literature reveals a few common imaging features amongst most ectopic lesions, including cyst formation. We report a 24-year-old man with panhypopituitarism. Neuroimaging revealed three enhancing lesions involving the pituitary infundibulum, the pineal region, and a parenchymal lesion involving the genu of the corpus callosum. The described ectopic mass, a parenchymal lesion, was associated with small peripheral cysts. Stereotactic biopsy and histopathological evaluation revealed this mass to be a germinoma. Following chemotherapy and radiation therapy, there was near-total resolution of the intracranial disease. Preoperative imaging plays an important role, not only in delineating the extent of disease, but also in assisting in generating an appropriate differential diagnosis. Germinomas in the corpus callosum are exceedingly rare but should be considered in the differential of any young patient with a characteristic cystic and solid intra-axial mass. PMID:27050919

  13. Transmission enhancement through deep subwavelength apertures using connected split ring resonators.

    PubMed

    Ates, Damla; Cakmak, Atilla Ozgur; Colak, Evrim; Zhao, Rongkuo; Soukoulis, C M; Ozbay, Ekmel

    2010-02-15

    We report astonishingly high transmission enhancement factors through a subwavelength aperture at microwave frequencies by placing connected split ring resonators in the vicinity of the aperture. We carried out numerical simulations that are consistent with our experimental conclusions. We experimentally show higher than 70,000-fold extraordinary transmission through a deep subwavelength aperture with an electrical size of lambda/31 x lambda/12 (width x length), in terms of the operational wavelength. We discuss the physical origins of the phenomenon. Our numerical results predict that even more improvements of the enhancement factors are attainable. Theoretically, the approach opens up the possibility for achieving very large enhancement factors by overcoming the physical limitations and thereby minimizes the dependence on the aperture geometries. PMID:20389408

  14. The Serotonin 2C Receptor Agonist Lorcaserin Attenuates Intracranial Self-Stimulation and Blocks the Reward-Enhancing Effects of Nicotine.

    PubMed

    Zeeb, Fiona D; Higgins, Guy A; Fletcher, Paul J

    2015-07-15

    Lorcaserin, a serotonin (5-hydroxytryptamine, 5-HT) 2C receptor agonist, was recently approved for the treatment of obesity. We previously suggested that 5-HT2C receptor agonists affect reward processes and reduce the rewarding effects of drugs of abuse. Here, we determined whether lorcaserin (1) decreases responding for brain stimulation reward (BSR) and (2) prevents nicotine from enhancing the efficacy of BSR. Rats were trained on the intracranial self-stimulation (ICSS) paradigm to nosepoke for BSR of either the dorsal raphé nucleus or left medial forebrain bundle. In Experiment 1, lorcaserin (0.3-1.0 mg/kg) dose-dependently reduced the efficacy of BSR. This effect was blocked by prior administration of the 5-HT2C receptor antagonist SB242084. In Experiment 2, separate groups of rats received saline or nicotine (0.4 mg/kg) for eight sessions prior to testing. Although thresholds were unaltered in saline-treated rats, nicotine reduced reward thresholds. An injection of lorcaserin (0.3 mg/kg) prior to nicotine prevented the reward-enhancing effect of nicotine across multiple test sessions. These results demonstrated that lorcaserin reduces the rewarding value of BSR and also prevents nicotine from facilitating ICSS. Hence, lorcaserin may be effective in treating psychiatric disorders, including obesity and nicotine addiction, by reducing the value of food or drug rewards. PMID:25781911

  15. Gemini-Monoceros X-ray enhancement: A giant X-ray ring

    SciTech Connect

    Nousek, J.A.; Cowie, L.L.; Hu, E.; Lindblad, C.J.; Garmire, G.P.

    1981-08-15

    A 1/sup 0/.5 spatial resolution map of the 1/4 keV diffuse X-ray background enhancement in the Gemini and Monoceros constellations shows a striking, circular, ring-shaped emission feature with a diameter of about 20/sup 0/. At a distance of 300 pc, the region has a radius of 50 pc and, for a spectral temperature of 3 x 10/sup 6/ K, an emitting electron density of 0.01 cm/sup -3/. We discuss this feature and, also, the possible X-ray contribution from the Mon OB1 association and neighboring supernova remnants.

  16. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

    MedlinePlus

    ... Asked Questions Español Condiciones Chinese Conditions Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) En Español Read in Chinese What is idiopathic intracranial hypertension? Idiopathic intracranial hypertension (IIH) is a disorder that ...

  17. Intracranial capillary hemangioma in an elderly patient

    PubMed Central

    Okamoto, Ai; Nakagawa, Ichiro; Matsuda, Ryosuke; Nishimura, Fumihiko; Motoyama, Yasushi; Park, Young-Su; Nakamura, Mitsutoshi; Nakase, Hiroyuki

    2015-01-01

    Background: Capillary hemangiomas are neoplasms involving skin and soft tissue in infants. These lesions rarely involved an intracranial space and reported age distribution ranges from infancy to middle age. We report an extremely rare case of rapidly rising intracranial capillary hemangioma in an elderly woman. Case Description: The 82-year-old woman presented with vomiting, reduced level of consciousness, and worsening mental state. Computed tomography showed a contrast-enhanced extra-axial lesion in the left frontal operculum, although no intracranial mass lesion was identifiable from magnetic resonance imaging taken 2 years earlier. Complete surgical excision was performed and histopathological examination diagnosed benign capillary hemangioma consisting of a variety of dilated capillary blood vessels lined by endothelial cells. Conclusion: This is the first description of rapid growth of an intracranial capillary hemangioma in an elderly woman. These lesions are exceedingly rare in the elderly population, but still show the capacity for rapid growth. Complete excision would prevent further recurrence. PMID:26664868

  18. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect

    Mukai, Y.; Hirori, H.; Yamamoto, T.; Kageyama, H.; Tanaka, K.

    2014-07-14

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  19. Primary Intracranial Choriocarcinoma Located in the Suprasellar Region

    PubMed Central

    Li, Xiuli; Murayama, Kazuhiro; Watanabe, Ayumi; Abe, Masato; Toyama, Hiroshi

    2016-01-01

    A 10 year old girl was admitted to our hospital due to headache, nausea, and weight loss for about half a year. She also had visual field disorders. Suprasellar tumor was found by X-ray computed tomography, and magnetic resonance imaging showed a ring-like lobulated enhanced mass with hemorrhage and necrosis. Biopsy of this lesion showed primary intracranial choriocarcinoma on histopathological examination. The serum human chorionic gonadotropin (hCG) level was measured after the biopsy and was elevated at 71,298.2 IU/L. The patient died due to hydrocephalus caused by an increase in the size of the tumor with a larger amount of hemorrhage than the preoperative features. If young patients present with a suprasellar lobulated mass with hemorrhage, the serum hCG level should be measured before operation. PMID:27499824

  20. SpyRings Declassified: A Blueprint for Using Isopeptide-Mediated Cyclization to Enhance Enzyme Thermal Resilience.

    PubMed

    Schoene, C; Bennett, S P; Howarth, M

    2016-01-01

    Enzymes often have marginal stability, with unfolding typically leading to irreversible denaturation. This sensitivity is a major barrier, both for de novo enzyme development and for expanding enzyme impact beyond the laboratory. Seeking an approach to enhance resilience to denaturation that could be applied to a range of different enzymes, we developed SpyRing cyclization. SpyRings contain genetically encoded SpyTag (13 amino acids) on the N-terminus and SpyCatcher (12kDa) on the C-terminus of the enzyme, so that the Spy partners spontaneously react together through an irreversible isopeptide bond. SpyRing cyclization gave major increases in thermal resilience, including on a model for enzyme evolution, β-lactamase, and an industrially important enzyme in agriculture and nutrition, phytase. We outline the SpyRing rationale, including comparison of SpyRing cyclization to other cyclization strategies. The cloning strategy is presented for the simple insertion of enzyme genes for recombinant expression. We discuss structure-based approaches to select suitable enzyme cyclization targets. Approaches to evaluate the cyclization reaction and its effect on enzyme resilience are described. We also highlight the use of differential scanning calorimetry to understand how SpyRing cyclization promotes enzyme refolding. Efficiently searching sequence space will continue to be important for enzyme improvement, but the SpyRing platform may be a valuable rational adjunct for conferring resilience. PMID:27586332

  1. Convection-enhanced delivery of a synthetic retinoid Am80, loaded into polymeric micelles, prolongs the survival of rats bearing intracranial glioblastoma xenografts.

    PubMed

    Yokosawa, Michiko; Sonoda, Yukihiko; Sugiyama, Shin-ichiro; Saito, Ryuta; Yamashita, Yoji; Nishihara, Masamichi; Satoh, Taku; Kumabe, Toshihiro; Yokoyama, Masayuki; Tominaga, Teiji

    2010-08-01

    Prognosis for the patients with glioblastoma, the most common malignant brain tumor, remains dismal. A major barrier to progress in treatment of glioblastoma is the relative inaccessibility of tumors to chemotherapeutic agents. Convection-enhanced delivery (CED) is a direct intracranial drug infusion technique to deliver chemotherapeutic agents to the central nervous system, circumventing the blood-brain barrier and reducing systemic side effects. CED can provide wider distribution of infused agents compared to simple diffusion. We have reported that CED of a polymeric micelle carrier system could yield a clinically relevant distribution of encapsulated agents in the rat brain. Our aim was to evaluate the efficacy of CED of polymeric micellar Am80, a synthetic agonist with high affinity to nuclear retinoic acid receptor, in a rat model of glioblastoma xenografts. We also used systemic administration of temozolomide, a DNA-alkylating agent, which has been established as the standard of care for newly diagnosed malignant glioma. U87MG human glioma cells were injected into the cerebral hemisphere of nude rats. Rats bearing U87MG xenografts were treated with CED of micellar Am80 (2.4 mg/m(2)) on day 7 after tumor implantation. Temozolomide (200 mg/m(2)/day) was intraperitoneally administered daily for 5 days, starting on day 7 after tumor implantation. CED of micellar Am80 provided significantly longer survival than the control. The combination of CED of micellar Am80 and systemic administration of temozolomide provided significantly longer survival than single treatment. In conclusion, temozolomide combined with CED of micellar Am80 may be a promising method for the treatment of malignant gliomas. PMID:20622491

  2. Quantum enhanced measurement of rotations with a spin-1 Bose-Einstein condensate in a ring trap

    NASA Astrophysics Data System (ADS)

    Nolan, Samuel P.; Sabbatini, Jacopo; Bromley, Michael W. J.; Davis, Matthew J.; Haine, Simon A.

    2016-02-01

    We present a model of a spin-squeezed rotation sensor utilizing the Sagnac effect in a spin-1 Bose-Einstein condensate in a ring trap. The two input states for the interferometer are seeded using Raman pulses with Laguerre-Gauss beams and are amplified by the bosonic enhancement of spin-exchange collisions, resulting in spin-squeezing and potential quantum enhancement of the interferometry. The ring geometry has an advantage over separated beam path atomic rotation sensors due to the uniform condensate density. We model the interferometer both analytically and numerically for realistic experimental parameters and find that significant quantum enhancement is possible, but this enhancement is partially degraded when working in a regime with strong atomic interactions.

  3. Intracranial pressure monitoring

    MedlinePlus

    ICP monitoring; CSF pressure monitoring ... There are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

  4. Intracranial pressure monitoring

    MedlinePlus

    ... head. The monitor senses the pressure inside the skull and sends measurements to a recording device. ... are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is ...

  5. Enhancement of persistent current in mesoscopic rings and cylinders: shortest and next possible shortest higher-order hopping

    NASA Astrophysics Data System (ADS)

    Maiti, Santanu K.; Chowdhury, J.; Karmakar, S. N.

    2006-06-01

    We present a detailed study of persistent current and low-field magnetic susceptibility in single isolated normal metal mesoscopic rings and cylinders in the tight-binding model with higher-order hopping integral in the Hamiltonian. Our exact calculations show that order of magnitude enhancement of persistent current takes place even in the presence of disorder if we include the higher-order hopping integral in the Hamiltonian. In strictly one-channel mesoscopic rings the sign of the low-field currents can be predicted exactly even in the presence of impurity. We observe that perfect rings with both odd and even numbers of electrons support only diamagnetic currents. On the other hand in the disordered rings, irrespective of realization of the disordered configurations of the ring, we always get diamagnetic currents with odd numbers of electrons and paramagnetic currents with even numbers of electrons. In mesoscopic cylinders the sign of the low-field currents cannot be predicted exactly since it strongly depends on the total number of electrons, Ne, and also on the disordered configurations of the system. From the variation of persistent current amplitude with system size for constant electron density, we conclude that the enhancement of persistent current due to additional higher-order hopping integrals is visible only in the mesoscopic regime.

  6. Enhanced spin figure of merit in an Aharonov-Bohm ring with a double quantum dot

    SciTech Connect

    Zhou, Xingfei; Qi, Fenghua; Jin, Guojun

    2014-04-21

    We theoretically investigate the thermoelectric effects in an Aharonov-Bohm ring with a serially coupled double quantum dot embedded in one arm. An external magnetic field is perpendicularly applied to the two dots. Using the nonequilibrium Green's function method in the linear-response regime, we calculate the charge and spin figures of merit. When the energy levels of the two quantum dots are equal and the system is connected to two normal leads, a large spin figure of merit (Z{sub s}T ≈ 4.5) accompanying with a small charge figure of merit (Z{sub c}T ≈ 0) can be generated due to the remarkable bipolar effect. Further, when the system is connected to two ferromagnetic leads, the spin figure of merit can reach even a higher value about 9. Afterwards, we find that Z{sub s}T is enhanced while Z{sub c}T is reduced in the coaction of the Aharonov-Bohm flux and Rashba spin-orbit coupling. It is argued that the bipolar effect is positive (negative) to spin (charge) figure of merit in the presence of level detuning of the two quantum dots and intradot Coulomb interactions, respectively. Also, we propose a possible experiment to verify our results.

  7. Effect of linewidth enhancement factor in actively mode-locked ring laser

    NASA Astrophysics Data System (ADS)

    Takada, Akira; Saika, Makoto; Nagano, Shigenori

    2014-03-01

    Fundamental performance of the swept-source optical coherence tomography (SS-OCT) system is defined by its wavelength-swept laser. Especially narrower instantaneous spectral linewidth of the laser has the advantage in deeprange tomography. We have demonstrated narrow-linewidth actively mode-locked ring lasers (AMLL), employing anomalous dispersion configuration. The linewidth of an AMLL is determined by anomalous dispersion and self-phase modulation (SPM) in the semiconductor optical amplifier (SOA). For such soliton-like phenomenon of AMLLs, numerical calculation predicts that both of large dispersion and small SPM make the linewidth narrower. Since the dispersion restricts wavelength sweeping range of AMLLs, too large dispersion cannot be used. To weaken the SPM effect, low linewidth enhancement factor α of SOA is desirable. Quantum-dot(QD)-based SOA offers low α-factor in comparison with quantum-well SOA (QWSOA). In this study, we employ a QDSOA as a gain medium in an AMLL and also use a QWSOA for comparison. The wavelength band of the QWSOA-AMLL is 1.5 μm and that of QDSOA-AMLL is 1.0 μm. Since we employed the 10 ps/nm of net dispersion in both configurations, the dispersion parameter β2 for the QDSOA-AMLL is approximately half of that for the QWSOA-AMLL. The measured full-width half-maximum (FWHM) linewidths in a static state were 0.08 nm for the QWSOA-AMLL and 0.04nm for the QDSOA-AMLL. In spite of the small β2 the QDSOA-AMLL achieves narrower spectral than the QWSOA-AMLL. We also confirmed that the interference signal was improved by adopting the QDSOA.

  8. Combined 3 Tesla MRI Biomarkers Improve the Differentiation between Benign vs Malignant Single Ring Enhancing Brain Masses

    PubMed Central

    Salice, Simone; Esposito, Roberto; Ciavardelli, Domenico; delli Pizzi, Stefano; di Bastiano, Rossella; Tartaro, Armando

    2016-01-01

    Purpose To evaluate whether the combination of imaging biomarkers obtained by means of different 3 Tesla (3T) Magnetic Resonance Imaging (MRI) advanced techniques can improve the diagnostic accuracy in the differentiation between benign and malignant single ring-enhancing brain masses. Materials and Methods 14 patients presenting at conventional 3T MRI single brain mass with similar appearance as regard ring enhancement, presence of peri-lesional edema and absence of hemorrhage signs were included in the study. All lesions were histologically proven: 5 pyogenic abscesses, 6 glioblastomas, and 3 metastases. MRI was performed at 3 Tesla and included Diffusion Weighted Imaging (DWI), Dynamic Susceptibility Contrast -Perfusion Weighted Imaging (DSC-PWI), Magnetic Resonance Spectroscopy (MRS), and Diffusion Tensor Imaging (DTI). Imaging biomarkers derived by those advanced techniques [Cerebral Blood Flow (CBF), relative Cerebral Blood Volume (rCBV), relative Main Transit Time (rMTT), Choline (Cho), Creatine (Cr), Succinate, N-Acetyl Aspartate (NAA), Lactate (Lac), Lipids, relative Apparent Diffusion Coefficient (rADC), and Fractional Anisotropy (FA)] were detected by two experienced neuroradiologists in joint session in 4 areas: Internal Cavity (IC), Ring Enhancement (RE), Peri-Lesional edema (PL), and Contralateral Normal Appearing White Matter (CNAWM). Significant differences between benign (n = 5) and malignant (n = 9) ring enhancing lesions were tested with Mann-Withney U test. The diagnostic accuracy of MRI biomarkers taken alone and MRI biomarkers ratios were tested with Receiver Operating Characteristic (ROC) analysis with an Area Under the Curve (AUC) ≥ 0.9 indicating a very good diagnostic accuracy of the variable. Results Five MRI biomarker ratios achieved excellent accuracy: IC-rADC/PL-NAA (AUC = 1), IC-rADC/IC-FA (AUC = 0.978), RE-rCBV/RE-FA (AUC = 0.933), IC-rADC/RE-FA (AUC = 0.911), and IC-rADC/PL-FA (AUC = 0.911). Only IC-rADC achieved a very good

  9. Primary Intracranial Synovial Sarcoma.

    PubMed

    Patel, Mohit; Li, Luyuan; Nguyen, Ha Son; Doan, Ninh; Sinson, Grant; Mueller, Wade

    2016-01-01

    Background. Synovial sarcoma is an aggressive soft tissue sarcoma with uncertain histological origin. The pathology frequently presents as a localized disease, especially near large joints around the knee and thigh. Intracranial disease, which is rare, has been reported as metastasis from synovial sarcoma. We report a case with no obvious primary extracranial pathology, suggesting primary intracranial disease; this has not been reported in the literature. Case Description. A 21-year-old male, with a prior right skull lesion resection for atypical spindle cell neoplasm, presented with headaches, gait instability, left arm weakness, and left homonymous hemianopsia. CT of head demonstrated a right parietal hemorrhagic lesion with mass effect, requiring surgical decompression. Histopathology revealed synovial sarcoma. FISH analysis noted the existence of the t(X;18)(p11.2;q11.2) chromosomal translocation. PET scan did not show other metastatic disease. He underwent stereotactic radiotherapy and adjuvant chemotherapy. At 2-year follow-up, he remained nonfocal without recurrence. Conclusion. We report the first known case of primary intracranial synovial sarcoma. Moreover, we stress that intracranial lesions may have a tendency for hemorrhage, requiring urgent lifesaving decompression. PMID:27247811

  10. Primary Intracranial Synovial Sarcoma

    PubMed Central

    Li, Luyuan; Sinson, Grant; Mueller, Wade

    2016-01-01

    Background. Synovial sarcoma is an aggressive soft tissue sarcoma with uncertain histological origin. The pathology frequently presents as a localized disease, especially near large joints around the knee and thigh. Intracranial disease, which is rare, has been reported as metastasis from synovial sarcoma. We report a case with no obvious primary extracranial pathology, suggesting primary intracranial disease; this has not been reported in the literature. Case Description. A 21-year-old male, with a prior right skull lesion resection for atypical spindle cell neoplasm, presented with headaches, gait instability, left arm weakness, and left homonymous hemianopsia. CT of head demonstrated a right parietal hemorrhagic lesion with mass effect, requiring surgical decompression. Histopathology revealed synovial sarcoma. FISH analysis noted the existence of the t(X;18)(p11.2;q11.2) chromosomal translocation. PET scan did not show other metastatic disease. He underwent stereotactic radiotherapy and adjuvant chemotherapy. At 2-year follow-up, he remained nonfocal without recurrence. Conclusion. We report the first known case of primary intracranial synovial sarcoma. Moreover, we stress that intracranial lesions may have a tendency for hemorrhage, requiring urgent lifesaving decompression. PMID:27247811

  11. Intracranial atherosclerosis following radiotherapy

    SciTech Connect

    Werner, M.H.; Burger, P.C.; Heinz, E.R.; Friedman, A.H.; Halperin, E.C.; Schold, S.C. Jr.

    1988-07-01

    We describe a case of severe intracranial atherosclerosis in a young man who had received therapeutic radiation for a presumed brain neoplasm. Since there was no evidence of vascular disease outside the radiation ports, we speculate that accelerated atherosclerosis was induced by radiation and that hyperlipidemia may have predisposed him to this effect.

  12. Noncontrast-enhanced three-dimensional (3D) intracranial MR angiography using pseudocontinuous arterial spin labeling and accelerated 3D radial acquisition.

    PubMed

    Wu, Huimin; Block, Walter F; Turski, Patrick A; Mistretta, Charles A; Johnson, Kevin M

    2013-03-01

    Pseudocontinuous arterial spin labeling (PCASL) can be used to generate noncontrast magnetic resonance angiograms of the cerebrovascular structures. Previously described PCASL-based angiography techniques were limited to two-dimensional projection images or relatively low-resolution three-dimensional (3D) imaging due to long acquisition time. This work proposes a new PCASL-based 3D magnetic resonance angiography method that uses an accelerated 3D radial acquisition technique (VIPR, spoiled gradient echo) as the readout. Benefiting from the sparsity provided by PCASL and noise-like artifacts of VIPR, this new method is able to obtain submillimeter 3D isotropic resolution and whole head coverage with a 8-min scan. Intracranial angiography feasibility studies in healthy (N = 5) and diseased (N = 5) subjects show reduced saturation artifacts in PCASL-VIPR compared with a standard time-of-flight protocol. These initial results show great promise for PCASL-VIPR for static, dynamic, and vessel selective 3D intracranial angiography. PMID:22532423

  13. Enhancement of performance by blade optimization in two-stage ring blower

    NASA Astrophysics Data System (ADS)

    Jang, Choon-Man; Han, Gi-Young

    2010-10-01

    This paper describes the shape optimization of an impeller used for two-stage high pressure ring blower. Two shape variables, which are used to define an impeller shape, are introduced to increase the blower performance. The pressure of a blower is selected as an object function, and the blade optimization is performed by a response surface method. Three-dimensional Navier-Stokes equations are introduced to analyze the internal flow of the blower and to find the value of object function for the training data. Relatively good agreement between experimental measurements and numerical simulation is obtained in the present study. Throughout the shape optimization, it is found that a hub height is effective to increase pressure in the ring blower. The pressure rise for the optimal two-stage ring blower is successfully increased up to 1.86% compared with that of reference at the design flow rate. Local recirculation flow having low velocity is formed in both sides of the impeller outlet by different flow direction of the inlet and outlet of the impeller. Detailed flow field inside the ring blower is also analyzed and discussed.

  14. When Evaluating a New Thyroid Mass and a Ring-Enhancing Brain Lesion (When Two Presentations Collide).

    PubMed

    Nicholas, Zachary; Sughrue, Michael; Battiste, James; Algan, Ozer

    2016-01-01

    We aimed to evaluate the clinical and pathologic features of two common medical illnesses and their appropriate workup and pathognomonic findings. A 57-year-old white male presented with a new onset expressive aphasia while traveling abroad. He was evaluated at an outside facility and underwent workup for a stroke. The evaluation included a CT and MRI of the brain demonstrating three new enhancing lesions, the largest of which was a 2.5 cm ring-enhancing cystic lesion. A CT of the chest noted a 4-cm cystic thyroid lesion that was diagnosed as a thyroid cancer with brain metastases. The patient was told that he had cancer and needed therapy. The patient elected to be treated closer to home and presented to our institution with a referral for brain irradiation. The patient was evaluated and his case was reviewed in a neuro/oncology tumor board, where several other possible diagnoses were considered. A complete workup was performed, including two separate FNAs of the thyroid mass along with a PET scan, CEA test, CBC test, CMP, CRP, sed rate, and SLE testing, along with a spinal tap (cytology, protein, and serology). The MRI on further review showed that one of the lesions was a periventricular enhancing area and the largest lesion was an open ring with T2 and DWI enhancement. The fine needle aspiration (FNA) samples of the thyroid both showed benign histology. The laboratory evaluation was negative except for a mildly elevated CRP with no tumor markers identified and the spinal tap was positive for elevated protein and particularly oligoclonal bands. The PET scan showed no sites of fluorodeoxyglucose (FDG) avid masses including the thyroid. Multiple sclerosis (MS) represents 400,000 cases in the US and benign thyroid nodules noted on imaging range from 19-35% of the population. One pathognomonic finding of MS that is less common is the open rings called tumefactive lesions versus the closed rings seen with metastases. A cystic thyroid lesion can range from a

  15. When Evaluating a New Thyroid Mass and a Ring-Enhancing Brain Lesion (When Two Presentations Collide)

    PubMed Central

    Sughrue, Michael; Battiste, James; Algan, Ozer

    2016-01-01

    We aimed to evaluate the clinical and pathologic features of two common medical illnesses and their appropriate workup and pathognomonic findings. A 57-year-old white male presented with a new onset expressive aphasia while traveling abroad. He was evaluated at an outside facility and underwent workup for a stroke. The evaluation included a CT and MRI of the brain demonstrating three new enhancing lesions, the largest of which was a 2.5 cm ring-enhancing cystic lesion. A CT of the chest noted a 4-cm cystic thyroid lesion that was diagnosed as a thyroid cancer with brain metastases. The patient was told that he had cancer and needed therapy. The patient elected to be treated closer to home and presented to our institution with a referral for brain irradiation. The patient was evaluated and his case was reviewed in a neuro/oncology tumor board, where several other possible diagnoses were considered. A complete workup was performed, including two separate FNAs of the thyroid mass along with a PET scan, CEA test, CBC test, CMP, CRP, sed rate, and SLE testing, along with a spinal tap (cytology, protein, and serology). The MRI on further review showed that one of the lesions was a periventricular enhancing area and the largest lesion was an open ring with T2 and DWI enhancement. The fine needle aspiration (FNA) samples of the thyroid both showed benign histology. The laboratory evaluation was negative except for a mildly elevated CRP with no tumor markers identified and the spinal tap was positive for elevated protein and particularly oligoclonal bands. The PET scan showed no sites of fluorodeoxyglucose (FDG) avid masses including the thyroid. Multiple sclerosis (MS) represents 400,000 cases in the US and benign thyroid nodules noted on imaging range from 19-35% of the population. One pathognomonic finding of MS that is less common is the open rings called tumefactive lesions versus the closed rings seen with metastases. A cystic thyroid lesion can range from a

  16. Intracranial chondroma: a rare entity

    PubMed Central

    Maheshwari, Veena; Mehdi, Ghazala; Varshney, Manoranjan; Jain, Anshu; Vashishtha, Sonal; Gaur, Kavita; Srivastava, Vinod Kumar

    2011-01-01

    Intracranial chondroma is a rare benign cartilaginous tumour with an incidence of less than 1% of all primary intracranial tumours. The authors are reporting here a case of intracranial chondroma in a 40-year-old man who presented with 5-month history of headache and gradual diminution of vision. A tentative diagnosis of chondroma was made on imprint cytology which was confirmed on histopathological examination. PMID:22696735

  17. Van Allen Probes based investigation of storm time enhancements in the duskward electric field to lower L shells and its effect on ring current formation and plasmasphere erosion.

    NASA Astrophysics Data System (ADS)

    Thaller, S. A.; Wygant, J. R.; Dai, L.; Breneman, A. W.; Kersten, K.; Kletzing, C.; Kurth, W. S.; De Pascuale, S.; Bonnell, J. W.; Hospodarsky, G. B.; Gkioulidou, M.; Fennell, J. F.

    2014-12-01

    The large scale convection electric field plays a central role in the dynamics of the inner magnetosphere; among which processes are ring current particle injection and plasmasphere erosion. Both of these are important for radiation belt dynamics. The ring current affects magnetic field geometry which in turn affects particle drift paths and plasmasphere erosion shrinks the region characterized by plasmaspheric hiss which would otherwise be present to scatter population of radiation belt seed electrons. Using the Van Allen Probes we investigate enhancements in the duskward electric field to lower L shells (L < 4 RE) and its role in ring current particle energization and erosion of the plasmasphere during two major storms; June 1, 2013 and February 19, 2014. During these storms, the electric field enhanced to low L shells with magnitudes ~1-2 mV/m in the co-rotating frame. The corresponding storm time ring current enhancements and plasmasphere erosions are examined in the context of these electric fields. The intensification in the duskward electric field is of long enough duration to transport particles from locations characteristic of the earthward edge of the plasma sheet (L shells ~ 8-10 RE) to the observed location of the ring current while energizing them though conservation of the first adiabatic invariant to energies typical of the ring current. It is also observed that the range in L shell over which the most intense nightside, duskward, electric field is observed is also that over which the higher pressure region of the ring current is located.

  18. Intracranial Hypertension in Children without Papilledema.

    PubMed

    Chelse, Ana B; Epstein, Leon G

    2015-08-01

    Researchers at Nationwide Children's Hospital studied the frequency of intracranial hypertension without papilledema in children followed in a multispecialty pediatric intracranial hypertension clinic. PMID:26933598

  19. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry

    2014-03-01

    Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

  20. Intracranial haemorrhage in pregnancy

    PubMed Central

    Fairhall, Jacob M; Stoodley, Marcus A

    2009-01-01

    Intracranial haemorrhage (ICH) is a rare, yet potentially devastating event in pregnancy. There is a risk of maternal mortality or morbidity and a significant risk to the unborn child. The risk of haemorrhage increases during the third trimester and is greatest during parturition and the puerperium. ICH can be extradural, subdural, subarachnoid or intraparenchymal. Causes of bleeding include trauma, arteriovenous malformations, aneurysms, preeclampsia/eclampsia and venous thrombosis. Urgent neurosurgical conditions generally outweigh obstetric considerations in management decisions, although anaesthetic and surgical modifications can be made to minimize adverse effects to the fetus.

  1. Intracranial hypotension after syringopleural shunting in posttraumatic syringomyelia: Case report and review of the literature.

    PubMed

    Summers, Johanne C; Vellore, Yagnesh; Chan, Patrick C H; Rosenfeld, Jeffrey V

    2015-01-01

    We report a case of a 45-year-old male with a syringopleural shunt who developed intracranial hypotension. The patient presented with 2 weeks history of worsening headache and back pain, on a background of having had a syringopleural shunt inserted for a thoracic posttraumatic syrinx. Computerized tomography imaging of the brain revealed bilateral subdural fluid collections. Magnetic resonance imaging appearances of spinal and intracranial pachymeningeal enhancement confirmed intracranial hypotension. We present a rare case of intracranial hypotension secondary to syringopleural shunting in a patient with posttraumatic syringomyelia. PMID:25972956

  2. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    DOE PAGESBeta

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fsmore » of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.« less

  3. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    SciTech Connect

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fs of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.

  4. Giant electric field enhancement in split ring resonators featuring nanometer-sized gaps.

    PubMed

    Bagiante, S; Enderli, F; Fabiańska, J; Sigg, H; Feurer, T

    2015-01-01

    Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales. Driven by standard laser sources THz electric field strengths of up to several MVm(-1) have been reported and in order to reach even higher electric field strengths the use of dedicated electric field enhancement structures has been proposed. Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz. These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations. PMID:25623373

  5. An impact of the ring substitution in nicorandil on its adsorption on silver nanoparticles. Surface-enhanced Raman spectroscopy studies.

    PubMed

    Jaworska, Aleksandra; Malek, Kamilla; Marzec, Katarzyna M; Baranska, Malgorzata

    2014-08-14

    The substituent effect on structure and surface activity of biologically active nicorandil was investigated by means of surface-enhanced Raman spectroscopy (SERS). Vibrational characterization was a basis for investigation of the adsorption profile of nicorandil and 1-methylnicorandil on silver nanoparticles. An assignment of SERS bands was performed by the comparison of the Raman spectra of both compounds in the solid state and in solutions, complemented by DFT calculations. Even though the nitro group was found to be the most attractive to the silver surface, the strong impact of the methyl substituent changed this preferable adsorption mechanism in 1-methylnicorandil. Protonation of the nitrogen atom in the pyridinium ring was also found to have an impact on absorption mechanism. PMID:24759187

  6. Gold Nanoparticle Coated Carbon Nanotube Ring with Enhanced Raman Scattering and Photothermal Conversion Property for Theranostic Applications.

    PubMed

    Song, Jibin; Wang, Feng; Yang, Xiangyu; Ning, Bo; Harp, Mary G; Culp, Stephen H; Hu, Song; Huang, Peng; Nie, Liming; Chen, Jingyi; Chen, Xiaoyuan

    2016-06-01

    We report a new type of carbon nanotube ring (CNTR) coated with gold nanoparticles (CNTR@AuNPs) using CNTR as a template and surface attached redox-active polymer as a reducing agent. This nanostructure of CNTR bundle embedded in the gap of closely attached AuNPs can play multiple roles as a Raman probe to detect cancer cells and a photoacoustic (PA) contrast agent for imaging-guided cancer therapy. The CNTR@AuNP exhibits substantially higher Raman and optical signals than CNTR coated with a complete Au shell (CNTR@AuNS) and straight CNT@AuNP. The extinction intensity of CNTR@AuNP is about 120-fold higher than that of CNTR at 808 nm, and the surface enhanced Raman scattering (SERS) signal of CNTR@AuNP is about 110 times stronger than that of CNTR, presumably due to the combined effects of enhanced coupling between the embedded CNTR and the plasmon mode of the closely attached AuNPs, and the strong electromagnetic field in the cavity of the AuNP shell originated from the intercoupling of AuNPs. The greatly enhanced PA signal and photothermal conversion property of CNTR@AuNP were successfully employed for imaging and imaging-guided cancer therapy in two tumor xenograft models. Experimental observations were further supported by numerical simulations and perturbation theory analysis. PMID:27193381

  7. Role of dynamic CT perfusion study in evaluating various intracranial space-occupying lesions

    PubMed Central

    Kamble, Ravindra B; Jayakumar, Peruvumba N; Shivashankar, Ravishankar

    2015-01-01

    Aims: Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL), differentiate benign and malignant lesions, and differentiate between grades of gliomas. Materials and Methods: We performed CT perfusion (CTP) in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV). Results: We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Conclusion: Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible. PMID:25969639

  8. Network connectivity enhancement by exploiting all optical multicast in semiconductor ring laser

    NASA Astrophysics Data System (ADS)

    Siraj, M.; Memon, M. I.; Shoaib, M.; Alshebeili, S.

    2015-03-01

    The use of smart phone and tablet applications will provide the troops for executing, controlling and analyzing sophisticated operations with the commanders providing crucial documents directly to troops wherever and whenever needed. Wireless mesh networks (WMNs) is a cutting edge networking technology which is capable of supporting Joint Tactical radio System (JTRS).WMNs are capable of providing the much needed bandwidth for applications like hand held radios and communication for airborne and ground vehicles. Routing management tasks can be efficiently handled through WMNs through a central command control center. As the spectrum space is congested, cognitive radios are a much welcome technology that will provide much needed bandwidth. They can self-configure themselves, can adapt themselves to the user requirement, provide dynamic spectrum access for minimizing interference and also deliver optimal power output. Sometimes in the indoor environment, there are poor signal issues and reduced coverage. In this paper, a solution utilizing (CR WMNs) over optical network is presented by creating nanocells (PCs) inside the indoor environment. The phenomenon of four-wave mixing (FWM) is exploited to generate all-optical multicast using semiconductor ring laser (SRL). As a result same signal is transmitted at different wavelengths. Every PC is assigned a unique wavelength. By using CR technology in conjunction with PC will not only solve network coverage issue but will provide a good bandwidth to the secondary users.

  9. Rings of saturn-like” nanoarrays with high number density of hot spots for surface-enhanced Raman scattering

    SciTech Connect

    Dai, Zhigao; Liao, Lei; Wu, Wei; Guo, Shishang; Zhao, Xinyue; Li, Wei; Ren, Feng; Jiang, Changzhong E-mail: czjiang@whu.edu.cn; Mei, Fei; Xiao, Xiangheng E-mail: czjiang@whu.edu.cn; Fu, Lei; Wang, Jiao

    2014-07-21

    The Ag nanoparticles (NPs) surrounding triangular nanoarrays (TNAs) with high number density of surface-enhanced Raman scattering (SERS) hot spots (SERS hot spots ring) are prepared by a combination of NPs deposition and subsequent colloid lithography processing. Owing to the SERS hot spots ring, the Ag NPs surrounding TNAs have been proved an excellent candidate for ultrasensitive molecular sensing for their high SERS signal enhancing capacity in experiments and theories. The Ag NPs surrounding TNAs can be readily used for the quick detection of low concentrations of molecules related to food safety; herein, detection of melamine is discussed.

  10. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry W.

    2011-07-01

    Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

  11. Intracranial aneurysm and sildenafil

    PubMed Central

    Edriss, Hawa; Nugent, Kenneth

    2016-01-01

    Sildenafil is one of the most commonly used drugs for the treatment of erectile dysfunction. To date, we found five reported cases of intracerebral bleeding and two reported cases of subarachnoid hemorrhage related to sildenafil use. We report a 49-year-old hypertensive and diabetic patient who presented with acute pulmonary edema and loss of consciousness following ingestion of 100 mg of sildenafil prior to sexual intercourse. He was not previously aware of the presence of an aneurysm and had no family history of it. Computed tomography of his head revealed a subarachnoid hemorrhage due to rupture of a saccular aneurysm with subsequent repeat hemorrhage within a few hours of presentation. A sudden increase in blood pressure led to pulmonary edema. Studies have shown that sildenafil acts on phosphodiesterase-1, -2 and -5 receptors and leads to a secondary increase in intracerebral circulation and vasodilatory effects, leading to sympathetic overactivity which increases the risk for intracranial bleeding. PMID:27034561

  12. Performance Enhancement of Space-Time Adaptive Processing for GPS and Microstrip Antenna Design Using Ferrite Rings

    NASA Astrophysics Data System (ADS)

    Rivera-Albino, Alix

    Global Positioning System (GPS) is a navigation system widely used in civilian and military application, but its accuracy is highly impacted with consequential fading, and possible loss of communication due to multipath propagation and high power interferences. This dissertation proposes alternatives to improve the performance of the GPS receivers to obtain a system that can be reliable in critical situations. The basic performance of the GPS receiver consists of receiving the signal with an antenna array, delaying the signal at each antenna element, weighting the delayed replicas, and finally, combining the weighted replicas to estimate the desired signal. Based on these, three modifications are proposed to improve the performance of the system. The first proposed modification is the use of the Least Mean Squares (LMS) algorithm with two variations to decrease the convergence time of the classic LMS while achieving good system stability. The results obtained by the proposed LMS demonstrate that the algorithm can achieve the same stability as the classic LMS using a small step size, and its convergence rate is better than the classic LMS using a large step size. The second proposed modification is to replace the uniform distribution of the time delays (or taps) by an exponential distribution that decreases the bit-error rate (BER) of the system without impacting the computational efficiency of the uniform taps. The results show that, for a BER of 0.001, the system can operate with a 1 to 2 dB lower signal-to-noise ratio (SNR) when an exponential distribution is used rather than a uniform distribution. Finally, the third modification is implemented in the design of the antenna array. In this case, the gain of each microstrip element is enhanced by embedding ferrite rings in the substrate, creating a hybrid substrate. The ferrite rings generates constructive interference between the incident and reflected fields; consequently, the gain of a single microstrip element

  13. Effect of parametric variation on generation and enhancement of chaos in erbium-doped fiber-ring lasers

    NASA Astrophysics Data System (ADS)

    Ali, Syed Zafar; Islam, Muhammad Khawar; Zafrullah, Muhammad

    2010-10-01

    The simulation and numerical analysis of erbium-doped fiber-ring lasers for generation and enhancement of chaos is presented. The degree of chaos determines the level of security in chaotic optical communication systems. Various parameters such as pump power, modulation index, modulation frequency, decay rate, and cavity gain can be varied as a control in producing higher degree optical chaos. The effect of each pertinent model parameter is analyzed in time-expanded mode using a phase plot direct-observation method and time series analysis of the time domain wave form by calculating its Lyapunov exponents. The mathematical and numerical analysis of the generated chaos helps in generalizing the trend through variation of cavity parameters and driving conditions in achieving a relatively higher degree of chaos. These trends help in optimizing various parameters for generation of new sequences of optical chaos in realizing better security. To gain an insight into chaotic signatures, the width and height of individual pulses, relationship of their time periods, gain quenching, shape, formation of bunches, and humps of the chaotic wave forms are also analyzed. The study of individual and cumulative behavior of all the parameters in enhancing optical chaos leads toward a reliable development in designing secure communication systems.

  14. Modeling of Intracranial Pressure Dynamics

    PubMed Central

    Griffith, Richard L.; Sullivan, Humbert G.; Miller, J. Douglas

    1978-01-01

    Digital computer simulation is utilized to test hypotheses regarding poorly understood mechanisms of intracranial pressure change. The simulation produces graphic output similar to records from polygraph recorders used in patient monitoring and in animal experimentation. The structure of the model is discussed. The mathematic model perfected by the comparison between simulation and experiment will constitute a formulation of medical information applicable to automated clinical monitoring and treatment of intracranial hypertension.

  15. Coil Embolization for Intracranial Aneurysms

    PubMed Central

    2006-01-01

    Executive Summary Objective To determine the effectiveness and cost-effectiveness of coil embolization compared with surgical clipping to treat intracranial aneurysms. The Technology Endovascular coil embolization is a percutaneous approach to treat an intracranial aneurysm from within the blood vessel without the need of a craniotomy. In this procedure, a microcatheter is inserted into the femoral artery near the groin and navigated to the site of the aneurysm. Small helical platinum coils are deployed through the microcatheter to fill the aneurysm, and prevent it from further expansion and rupture. Health Canada has approved numerous types of coils and coil delivery systems to treat intracranial aneurysms. The most favoured are controlled detachable coils. Coil embolization may be used with other adjunct endovascular devices such as stents and balloons. Background Intracranial Aneurysms Intracranial aneurysms are the dilation or ballooning of part of a blood vessel in the brain. Intracranial aneurysms range in size from small (<12 mm in diameter) to large (12–25 mm), and to giant (>25 mm). There are 3 main types of aneurysms. Fusiform aneurysms involve the entire circumference of the artery; saccular aneurysms have outpouchings; and dissecting aneurysms have tears in the arterial wall. Berry aneurysms are saccular aneurysms with well-defined necks. Intracranial aneurysms may occur in any blood vessel of the brain; however, they are most commonly found at the branch points of large arteries that form the circle of Willis at the base of the brain. In 85% to 95% of patients, they are found in the anterior circulation. Aneurysms in the posterior circulation are less frequent, and are more difficult to treat surgically due to inaccessibility. Most intracranial aneurysms are small and asymptomatic. Large aneurysms may have a mass effect, causing compression on the brain and cranial nerves and neurological deficits. When an intracranial aneurysm ruptures and bleeds

  16. A fluorometric microarray with ZnO substrate-enhanced fluorescence and suppressed ``coffee-ring'' effects for fluorescence immunoassays

    NASA Astrophysics Data System (ADS)

    Li, Shuying; Dong, Minmin; Li, Rui; Zhang, Liyan; Qiao, Yuchun; Jiang, Yao; Qi, Wei; Wang, Hua

    2015-11-01

    A glass slide was first patterned with hydrophobic hexadecyltrimethoxysilane (HDS) and then microspotted with hydrophilic ZnO nanoparticles in an aminopropyltriethoxysilane (APS) matrix. The resulting HDS-ZnO-APS microarray could present the capability of suppressing the undesirable ``coffee-ring'' effects through its hydrophobic pattern so as to allow the fabrication of ZnO-APS testing microspots with a highly dense and uniform distribution. The lotus-like ``self-cleaning'' function could also be expected to effectively curb the cross contamination of multiple sample droplets. More importantly, the introduction of ZnO nanoparticles could endow the testing microspots with substrate-enhanced fluorescence leading to signal-amplification microarray fluorometry. The practical application of the developed HDS-ZnO-APS microarray was investigated by the sandwiched fluorometric immunoassays of human IgG, showing a linear detection range from 0.010 to 10.0 ng mL-1. Such a throughput-improved fluorometric microarray could be tailored for probing multiple biomarkers in complicated media like serum or blood.A glass slide was first patterned with hydrophobic hexadecyltrimethoxysilane (HDS) and then microspotted with hydrophilic ZnO nanoparticles in an aminopropyltriethoxysilane (APS) matrix. The resulting HDS-ZnO-APS microarray could present the capability of suppressing the undesirable ``coffee-ring'' effects through its hydrophobic pattern so as to allow the fabrication of ZnO-APS testing microspots with a highly dense and uniform distribution. The lotus-like ``self-cleaning'' function could also be expected to effectively curb the cross contamination of multiple sample droplets. More importantly, the introduction of ZnO nanoparticles could endow the testing microspots with substrate-enhanced fluorescence leading to signal-amplification microarray fluorometry. The practical application of the developed HDS-ZnO-APS microarray was investigated by the sandwiched fluorometric

  17. O2.04TREATMENT WITH OMX-4.80, A TUMOR-PENETRATING TUNABLE OXYGEN CARRIER, REDUCES TUMOR HYPOXIA AND DRAMATICALLY ENHANCES RADIATION THERAPY IN INTRACRANIAL MODELS OF GLIOBLASTOMA

    PubMed Central

    Krtolica, A.; Le Moan, N.; Serwer, L.; Yoshida, Y.; Ozawa, T.; Butowski, N.; James, D.; Cary, S.

    2014-01-01

    We have developed OMX-4.80, a tunable oxygen carrier from the H-NOX protein family, that preferentially accumulates in tumor tissue, reduces hypoxia and enhances radiotherapy (RT). Tumor hypoxia is associated with poor patient outcomes in multiple solid tumors including glioblastoma (GB) and is thought to be a major contributor to poor cancer responses to chemo and radiation therapy. Here, we show that OMX-4.80 administered i.v. into the tail vein of mice bearing orthotopic GB passes the blood-tumor barrier, penetrates deep into intracranial tumors, and significantly reduces tumor hypoxia in a dose-dependent manner. Hypoxia reduction is demonstrated by a significant decrease in levels of hypoxia inducible factor, HIF1α, and the external hypoxia marker pimonidazole as assessed by IHC and image analysis. Furthermore, hypoxia before and after treatment is compared in the individual tumors by concurrent immunostaining of tumors with a long-term hypoxia marker, Glut1, and short-lived HIF-1α. These data reveal >50% reduction in hypoxic tumor area after OMX-4.80 treatment confirming the effectiveness of OMX-4.80 in reducing hypoxia in individual tumors. When OMX-4.80 treatment was coupled with a single high dose of RT, we observed a 2.7-fold increase in tumor growth delay and 2.9-fold longer survival (p < 0.05, by logrank). Toxicology studies in rodents and dogs with single and multiple supratherapeutic doses of OMX-4.80 revealed a good safety profile affirming its suitability for clinical development. In conclusion, our results indicate that OMX-4.80 is an effective and promising RT enhancer that warrants clinical development in GB patients.

  18. Intracranial complications following mastoidectomy.

    PubMed

    Migirov, Lela; Eyal, Ana; Kronenberg, Jona

    2004-01-01

    Mastoidectomy is a common surgical procedure in otology. However, postoperative complications of various degrees of severity may occur. We present 4 children who underwent mastoidectomy for middle ear and mastoid disease and developed postoperative intracranial complications. One child was operated on for brain abscess 1 week after the initial mastoidectomy. Another child appeared with seizures 5 days after the initial mastoidectomy and a subdural empyema was drained during revision surgery. Large bone defects with exposed middle cranial fossa dura were found at revision surgery in both cases and Proteus vulgaris and methicillin-resistant Staphylococcus aureus were isolated from the mastoid and abscess cavities in these children. A small epidural collection was diagnosed in the third patient 2 days after initial mastoid surgery and was managed with intravenous antibiotics only. The other child was found to have sigmoid sinus thrombosis the day after mastoidectomy that was performed for nonresponsive acute mastoiditis. This child received both intravenous antibiotics and anticoagulants. Timely revision surgery, combinations of third- or fourth-generation cephalosporins with vancomycin or metronidazole and the addition of anticoagulants in cases of sinus thrombosis can lead to full recovery. PMID:15689642

  19. Nonlocal Intracranial Cavity Extraction

    PubMed Central

    Manjón, José V.; Eskildsen, Simon F.; Coupé, Pierrick; Romero, José E.; Collins, D. Louis; Robles, Montserrat

    2014-01-01

    Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV) is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden. PMID:25328511

  20. Expression of a gene encoding a rice RING zinc-finger protein, OsRZFP34, enhances stomata opening.

    PubMed

    Hsu, Kuo-Hsuan; Liu, Chia-Chin; Wu, Shaw-Jye; Kuo, Ying-Yu; Lu, Chung-An; Wu, Ching-Rong; Lian, Pei-Jyun; Hong, Chwan-Yang; Ke, Yi-Ting; Huang, Juin-Hua; Yeh, Ching-Hui

    2014-09-01

    By oligo microarray expression profiling, we identified a rice RING zinc-finger protein (RZFP), OsRZFP34, whose gene expression increased with high temperature or abscisic acid (ABA) treatment. As compared with the wild type, rice and Arabidopsis with OsRZFP34 overexpression showed increased relative stomata opening even with ABA treatment. Furthermore, loss-of-function mutation of OsRZFP34 and AtRZFP34 (At5g22920), an OsRZFP34 homolog in Arabidopsis, decreased relative stomata aperture under nonstress control conditions. Expressing OsRZFP34 in atrzfp34 reverted the mutant phenotype to normal, which indicates a conserved molecular function between OsRZFP34 and AtRZFP34. Analysis of water loss and leaf temperature under stress conditions revealed a higher evaporation rate and cooling effect in OsRZFP34-overexpressing Arabidopsis and rice than the wild type, atrzfp34 and osrzfp34. Thus, stomata opening, enhanced leaf cooling, and ABA insensitivity was conserved with OsRZFP34 expression. Transcription profiling of transgenic rice overexpressing OsRZFP34 revealed many genes involved in OsRZFP34-mediated stomatal movement. Several genes upregulated or downregulated in OsRZFP34-overexpressing plants were previously implicated in Ca(2+) sensing, K(+) regulator, and ABA response. We suggest that OsRZFP34 may modulate these genes to control stomata opening. PMID:25002225

  1. Intramedullary Spinal Cord and Leptomeningeal Metastases from Intracranial Low-grade Oligodendroglioma

    PubMed Central

    Verma, Nipun; Nolan, Craig; Hirano, Miki; Young, Robert J

    2015-01-01

    We present an unusual case of a patient with an intracranial low-grade oligodendroglioma who developed recurrence with an intramedullary spinal cord metastasis and multiple spinal leptomeningeal metastases. The intramedullary spinal cord metastasis showed mild enhancement similar to the original intracranial primary, while the multiple spinal leptomeningeal metastases revealed no enhancement. This is the seventh reported case of symptomatic intramedullary spinal cord metastasis from a low-grade oligodendroglioma. PMID:24667044

  2. Management of Symptomatic Intracranial Stenosis.

    PubMed

    Hoak, David A; Lutsep, Helmi L

    2016-09-01

    Intracranial atherosclerotic disease is a common cause of stroke worldwide, causing approximately 10 % of strokes in the USA and up to 50 % in Asian populations. Recurrent stroke risks are particularly high in those with a stenosis of 70 % or more and a recent transient ischemic attack or stroke. Warfarin has been associated with higher major hemorrhage rates and no reduction of recurrent stroke compared to aspirin in patients with symptomatic intracranial stenosis. After early trials showed the feasibility of stenting, two randomized trials compared stenting plus medical management to medical management alone in symptomatic intracranial stenosis. Stenting was linked with increased risk and showed no benefit in any subpopulation of patients. Aggressive medical management in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial was associated with half the risk of stroke compared to that in similar patients in a previous symptomatic intracranial stenosis trial after adjustment of confounding characteristics. Aggressive medical management comprises risk factor control, including a target systolic blood pressure <140 mmHg, a low density lipoprotein <70 mg/dL, hemoglobin A1C <7.0 %, and lifestyle management that incorporates exercise, smoking cessation and weight management, and the use of antithrombotics. PMID:27443379

  3. Endovascular treatment of intracranial aneurysms.

    PubMed

    Diaz, Orlando; Rangel-Castilla, Leonardo

    2016-01-01

    Intracranial aneurysms are abnormal dilations of the intracranial vessels, in which all the layers of the vascular wall are affected by degenerative changes that lead to distension of the vessel. Intracranial aneurysms can be classified based on their anatomic location, size, and morphology. Subarachnoid hemorrhage is the most devastating clinical presentation. The goal of preventing hemorrhage or rehemorrhage can only be achieved by excluding the aneurysm from the cerebral circulation. Endovascular or surgical clipping can achieve this goal. Multiple surgical and endovascular approaches have been described for treatment of intracranial aneurysm. Surgical approaches for anterior-circulation intracranial aneurysms include: pterional, orbitozygomatic, and lateral supraorbital craniotomies. Modern microsurgical techniques involve skull base dissection to achieve adequate exposure with minimal brain retraction. Endovascular techniques can be divided into: parent artery reconstruction with coil deposition (primary coil, balloon-assisted coiling, stent-assisted coiling, and other new techniques such as neck reconstruction devices and intraluminal occlusion devices); reconstruction with flow diversion; and deconstructive techniques with involving parent artery sacrifice with or without bypass. PMID:27430470

  4. Children With Intracranial Arachnoid Cysts

    PubMed Central

    Tan, Zhen; Li, Yongxin; Zhu, Fengjun; Zang, Dongdong; Zhao, Cailei; Li, Cong; Tong, Dan; Zhang, Heye; Chen, Qian

    2015-01-01

    Abstract We performed a dynamic study of arachnoid cysts (ACs) using magnetic resonance cisternography (MRC) and proposed a classification of ACs. Twenty-three suitable patients in our hospital entered into this study according to our inclusion criteria. MRC images were collected in all the subjects at 1 and 24 hours after the administration of intrathecal gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA). We allocate the enrolled patients into 2 groups, MRC group and surgery group. The MRC results were considered before treatment in 1 group (MRC group, 13 patients), whereas another group was surgically treated without considering the MRC results (surgery group, 10 patients). We calculated the enhanced area of cyst using modified MacDonald Criteria from the images and measured the surrounding subarachnoid area as the reference. We found that it was practically useful to quantify 3 types of ACs, complete communicating, incomplete communicating, and noncommunicating, according to MRC results in this study. All the subjects in both groups are closely observed before the treatment and the follow-up using the MRI examination. In the surgery group, 5 patients were found that the area of cysts shrank in the follow-up stage. However, there was no significant difference in the percentage shrinkage area between the 2 groups. We concluded that MRC with Gd-DTPA as a contrast agent is of significant clinical value for the diagnosis and treatment of children with intracranial ACs. This classification based on dynamic MRC is useful for making surgical recommendations. PMID:26554773

  5. Primary intracranial lymphomas

    PubMed Central

    Mufti, Shagufta T.; Baeesa, Saleh S.; Al-Maghrabi, Jaudah A.

    2016-01-01

    Background: Primary CNS lymphoma (PCNSL), a rare form of aggressive extranodal non-Hodgkin's lymphoma (NHL), has increased in incidence during the last three decades and occurs in both immune compromised and immune competent hosts. It has an overall poor prognosis. Objective: This study attempts to further delineate the clinico-pathological, immunohistochemical and radiological profile of PCNSL at Jeddah to King Faisal Hospital and Research Center. Methods: Computerized search through the archives of King Faisal Hospital and Research Centre between July 2000- December 2012 identified 15 patients with pathologically confirmed PCNSL. These were analyzed retrospectively. Their clinico-pathological, immunohistochemical and radiological data were analyzed. Results: Of the 15 PCNSL patients, 8 (53.3%) were females and 7 (46.6%) were males. There was female predilection especially in the age group of 40-59 years. Mean age at diagnosis for all patients was 50.4 years. There was no patient in the pediatric age group. The most common location in the brain was the frontal region in 7 patients (46.6%), 7 (46.6%) had multiple intracranial masses; all 15 (100%) were Non Hodgkin B-cell lymphomas, among which 13 (86.6%) were diffuse large B-cell lymphomas. All 15 (100%) cases showed diffuse and strong positivity for CD 45, and CD 20. Fourteen patients were immune competent while one was immune compromised. Conclusions: PCNSL often occurs in middle-aged and aged patients. There is female predilection especially in the middle age. Frontal region is the most common location with diffuse large B-cell lymphoma being the predominant subtype. PMID:27366250

  6. Time Resolved Contrast Enhanced Intracranial MRA Using a Single Dose Delivered as Sequential Injections and Highly Constrained Projection Reconstruction (HYPR CE)

    PubMed Central

    Wu, Yijing; Johnson, Kevin; Kecskemeti, Steven R.; Wang, Kang; Wieben, Oliver; Aagaard-Kienitz, Beverly L.; Rowley, Howard; Korosec, Frank R.; Mistretta, Charles; Turski, Patrick

    2011-01-01

    Time-resolved contrast-enhanced magnetic resonance angiography of the brain is challenging due to the need for rapid imaging and high spatial resolution. Moreover, the significant dispersion of the intravenous contrast bolus as it passes through the heart and lungs increases the overlap between arterial and venous structures, regardless of the acquisition speed and reconstruction window. An innovative technique is presented that divides a single dose contrast into two injections. Initially a small volume of contrast material (2–3 mL) is used to acquiring time-resolved weighting images with a high frame rate (2 frames/s) during the first pass of the contrast agent. The remaining contrast material is used to obtain a high resolution whole brain contrast-enhanced (CE) magnetic resonance angiography (0.57 × 0.57 × 1 mm3) that is used as the spatial constraint for Local Highly Constrained Projection Reconstruction (HYPR LR) reconstruction. After HYPR reconstruction, the final dynamic images (HYPR CE) have both high temporal and spatial resolution. Furthermore, studies of contrast kinetics demonstrate that the shorter bolus length from the reduced contrast volume used for the first injection significantly improves the arterial and venous separation. PMID:21413059

  7. Treatment of intracranial foreign body.

    PubMed

    Karadas, Sevdegul; Dursun, Recep; Kiymaz, Nejmi

    2014-07-01

    Craniospinal penetrating foreign body (FB) injuries are interesting, but rarely observed, cases. They are important in terms of the complications that they may cause. The etiologies of craniospinal penetrating injuries and intracranial FB are also different. Though a sewing needle is more rarely seen in an intracranial FB, it may occur as atttempted infanticide or as a result of an accident especially in early childhood before the closure of fontanels. We detected an intracranial sewing needle in the head radiograph of a case admitted to the emergency department for another reason. We present this case since this is a rare injury and the etiologies of craniospinal penetrating foreign body have different characteristics. PMID:25255596

  8. Management of Unruptured Intracranial Aneurysms.

    PubMed

    Nasr, Deena M; Brown, Robert D

    2016-09-01

    Unruptured intracranial aneurysms (UIA) occur in approximately 2-3 % of the population. Most of these lesions are incidentally found, asymptomatic and typically carry a benign course. Although the risk of aneurysmal subarachnoid hemorrhage is low, this complication can result in significant morbidity and mortality, making assessment of this risk the cornerstone of UIA management. This article reviews important factors to consider when managing unruptured intracranial aneurysms including patient demographics, comorbidities, family history, symptom status, and aneurysm characteristics. It also addresses screening, monitoring, medical management and current surgical and endovascular therapies. PMID:27443382

  9. Chemical Sensing Using Infrared Cavity Enhanced Spectroscopy: Short Wave Infrared Cavity Ring Down Spectroscopy (SWIR CRDS) Sensor

    SciTech Connect

    Williams, Richard M.; Harper, Warren W.; Aker, Pam M.; Thompson, Jason S.; Stewart, Timothy L.

    2003-10-01

    The principal goal of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project is to explore and develop the science and technology behind point and stand off infrared (IR) spectroscopic chemical sensors that are needed for detecting weapons proliferation activity and countering terrorism. Missions addressed include detecting chemical, biological, and nuclear weapons and their production; counter terrorism measures that involve screening luggage, personnel, and shipping containers for explosives, firearms, narcotics, chemical weapons and/or their residues; and mapping of contaminated areas. The science and technology developed in this program is dual use in that it additionally supports progress in a diverse set of agendas that include chemical weapons defense programs, air operations activities, emissions monitoring, law enforcement, and medical diagnostics. Sensors for these missions require extremely low limits of detection because many of the targeted signature species are either present in low concentrations or have extremely low vapor pressures. The sensors also need to be highly selective as the environments that they will be operated in will contain a variety of interferent species and false positive detection is not an option. PNNL has been working on developing a class of sensors that draw vapor into optical cavities and use laser-based spectroscopy to identify and quantify the vapor chemical content. The cavity enhanced spectroscopies (CES) afford extreme sensitivity, excellent selectivity, noise immunity, and rapid, real-time, in-situ chemical characterization. PNNL's CES program is currently focused on developing two types of sensors. The first one, which is based on cavity ring down spectroscopy (CRDS), uses short wave infrared (SWIR) lasers to interrogate species. The second sensor, which is based on noise immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE OHMS), uses long wave infrared (LWIR) quantum cascade

  10. Smart multifunctional core-shell nanospheres with drug and gene co-loaded for enhancing the therapeutic effect in a rat intracranial tumor model.

    PubMed

    Wang, HanJie; Su, Wenya; Wang, Sheng; Wang, Xiaomin; Liao, Zhenyu; Kang, Chunsheng; Han, Lei; Chang, Jin; Wang, Guangxiu; Pu, Peiyu

    2012-10-21

    Glioblastoma with high mortality has been one of the most serious cancers threatening human health. Because of the present treatment limitations, there is an urgent need to construct a multifunctional vesicle for enhancing the treatment of in situ malignant glioblastoma. In our study, drug and gene co-loaded magnetic PLGA/multifunctional polymeric liposome (magnetic PLGA/MPLs) core-shell nanospheres were constructed. They were mainly self-assembled from two parts: hydrophobic PLGA cores that can load drugs and magnetic nanocrystals; and polymeric lipid shells anchored with functional molecules such as PEG chains, TAT peptides and RGD peptides that can help the vectors to condense the gene, prolong the circulation time, cross the blood brain barrier and target delivery to the cancer tissue. The results showed that the magnetic PLGA/MPLs nanosphere has a nanosized core-shell structure, can achieve sustained drug release and has good DNA binding abilities. Importantly, compared with the control group and other groups with single functionality, it can co-deliver the drug and gene into the same cell in vitro and show the strongest inhibiting effect on the growth of the in situ malignant glioblastoma in vivo. All of these results indicated that the different functional components of magnetic PLGA/MPLs, can form an organic whole and none of them can be dispensed with. The magnetic PLGA/MPLs nanosphere may be another option for treatment of glioblastoma. PMID:22961067

  11. Unruptured Intracranial Aneurysms:

    PubMed Central

    Raymond, J.; Nguyen, T.; Chagnon, M.; Gevry, G.

    2007-01-01

    'if a man will begin with certainties, he shall end in doubts; 'but if he will be content to begin with doubts he shall end in certainties'. Sir Francis Bacon, The Advancement of Learning Summary In the absence of level one evidence, the treatment of unruptured intracranial aneurysms is grounded on opinions. Results of the largest registry available, ISUIA (the International Study on Unruptured Intraacranial Aneurysms) suggest that surgical or endovascular treatments are rarely justified. Yet the unruptured aneurysm is the most frequent indication for treatment in many endovascular centres. In preparation for the initiation of a randomized trial, we aimed at a better knowledge of endovascular expert opinions on unruptured aneurysms. We administered a standard questionnaire to 175 endovascular experts gathered at the WFITN meeting in Val d'lsère in 2007. Four paradigm unruptured aneurysms were used to poll opinions on risks of treatment or observation, as well as on their willingness to treat, observe or propose to the patient participation in a randomized trial, using six questions for each aneurysm. Opinions varied widely among lesions and among participants. Most participants (92.5%) were consistent, as they would offer treatment only if their estimate of the ten-year risk of spontaneous hemorrhage would exceed risks of treatment. Estimates of the natural history were consistently higher than that reported by ISUIA. Conversely, treatment risks were underestimated compared to those reported in ISUIA, but within the range reported in a recent French registry (ATENA). Participants were more confident in their evaluation of treatment risks and in their skills at treating aneurysms than in their estimates of risks of rupture entailed by the presence of the lesion, the latter being anchored at or close to 1% /year. The gulf between expert opinions, clinical practices and available data from registries persist. Expert opinions are compatible with the primary hypothesis

  12. Smart multifunctional core-shell nanospheres with drug and gene co-loaded for enhancing the therapeutic effect in a rat intracranial tumor model

    NASA Astrophysics Data System (ADS)

    Wang, Hanjie; Su, Wenya; Wang, Sheng; Wang, Xiaomin; Liao, Zhenyu; Kang, Chunsheng; Han, Lei; Chang, Jin; Wang, Guangxiu; Pu, Peiyu

    2012-09-01

    Glioblastoma with high mortality has been one of the most serious cancers threatening human health. Because of the present treatment limitations, there is an urgent need to construct a multifunctional vesicle for enhancing the treatment of in situ malignant glioblastoma. In our study, drug and gene co-loaded magnetic PLGA/multifunctional polymeric liposome (magnetic PLGA/MPLs) core-shell nanospheres were constructed. They were mainly self-assembled from two parts: hydrophobic PLGA cores that can load drugs and magnetic nanocrystals; and polymeric lipid shells anchored with functional molecules such as PEG chains, TAT peptides and RGD peptides that can help the vectors to condense the gene, prolong the circulation time, cross the blood brain barrier and target delivery to the cancer tissue. The results showed that the magnetic PLGA/MPLs nanosphere has a nanosized core-shell structure, can achieve sustained drug release and has good DNA binding abilities. Importantly, compared with the control group and other groups with single functionality, it can co-deliver the drug and gene into the same cell in vitro and show the strongest inhibiting effect on the growth of the in situ malignant glioblastoma in vivo. All of these results indicated that the different functional components of magnetic PLGA/MPLs, can form an organic whole and none of them can be dispensed with. The magnetic PLGA/MPLs nanosphere may be another option for treatment of glioblastoma.Glioblastoma with high mortality has been one of the most serious cancers threatening human health. Because of the present treatment limitations, there is an urgent need to construct a multifunctional vesicle for enhancing the treatment of in situ malignant glioblastoma. In our study, drug and gene co-loaded magnetic PLGA/multifunctional polymeric liposome (magnetic PLGA/MPLs) core-shell nanospheres were constructed. They were mainly self-assembled from two parts: hydrophobic PLGA cores that can load drugs and magnetic

  13. Planetary rings

    SciTech Connect

    Greenberg, R.; Brahic, A.

    1984-01-01

    Among the topics discussed are the development history of planetary ring research, the view of planetary rings in astronomy and cosmology over the period 1600-1900, the characteristics of the ring systems of Saturn and Uranus, the ethereal rings of Jupiter and Saturn, dust-magnetosphere interactions, the effects of radiation forces on dust particles, the collisional interactions and physical nature of ring particles, transport effects due to particle erosion mechanisms, and collision-induced transport processes in planetary rings. Also discussed are planetary ring waves, ring particle dynamics in resonances, the dynamics of narrow rings, the origin and evolution of planetary rings, the solar nebula and planetary disk, future studies of the planetary rings by space probes, ground-based observatories and earth-orbiting satellites, and unsolved problems in planetary ring dynamics.

  14. The mathematical basis of adjunctive techniques for enhancement of vessel caliber to maximize coupler ring size for microanastomoses.

    PubMed

    Hallock, Geoffrey G

    2010-09-01

    The use of ring-pin devices as a nonsuture alternative for microanastomoses is expedient and highly practical, with excellent patency rates. A frequently encountered problem, though, is a significant discrepancy between the donor and recipient vessel lumen size. Rather than accepting the choice of a smaller ring size corresponding to the caliber of the smaller vessel, it may be preferable to instead increase the latter's circumference for potential eversion on the pins by either beveling or "fish-mouthing" the end of the vessel. Arithmetical calculations suggest that a 25% increase in dimensions can thereby be possible at least for thin-walled venous structures. Not only does the capability for selection of a size larger ring simplify drawing the vessel wall through the ring orifice prior to pin impalement, but the resulting larger anastomotic lumen should theoretically increase the potential flow rate across the microanastomosis. PMID:20464652

  15. Intracranial cholesterol granuloma in a cat.

    PubMed

    Ricci, Emanuele; Abbiati, Gianluca; Cantile, Carlo

    2010-11-01

    A case of intracranial cholesterol granuloma is described in a 4-year-old neutered European male cat presented with a 5-month history of progressive weakness, ataxia and depression. On clinical evaluation, haematological and biochemical profiles revealed only mild hypercholesterolemia and magnetic resonance imaging showed a large space-occupying extra-axial mass in the area of the falx, not homogeneous after contrast enhancement. At post-mortem examination, an orange-yellowish mass of 22 mm in diameter extended from the right frontal lobe to the temporo-parietal region, causing atrophy of the prosencephalic region of the brain. The site of origin of the mass was within the subarachnoid space of the supracallosum sulcus of the right cerebral hemisphere. Histological examination of the lesion revealed abundant deposits of cholesterol clefts, surrounded by clusters of macrophages and multinucleated giant cells. Neither inflammatory lesions, nor cholesterol deposits were detected in other areas of the brain and in other organs. On the basis of the histological examination, a diagnosis of intracranial cholesterol granuloma was made. PMID:20543528

  16. Surface-enhanced Raman spectra of medicines with large-scale self-assembled silver nanoparticle films based on the modified coffee ring effect

    NASA Astrophysics Data System (ADS)

    Zhou, Weiping; Hu, Anming; Bai, Shi; Ma, Ying; Su, Quanshuang

    2014-02-01

    We report here a simple and innovative method to prepare large-scale silver nanoparticle films based on the controlled coffee ring effect. It is demonstrated that the films can be used as surface-enhanced Raman scattering probes to detect low-concentration medicines. Silver nanoparticles with the average size about 70 nm were prepared by reduction of silver nitride. In our experiment, the coffee ring effect was controlled by tilting the substrates during the deposition of silver nanoparticle films. Silver nanoparticle films were spontaneously formed on the surface of silicon substrates at the temperatures about 50°C based on the solvent evaporation and the coffee ring effect. The microstructure of the films was investigated using the scanning electron microscope and atomic force microscope. The surface roughness of the films is found as small as 20 nm. Then, the films were exposed to aqueous solutions of medicine at different concentrations. A comparison with a Raman spectra measured with a conventional Raman spectrometer showed that the Raman signal can be detected in the solution with concentrations as low as 1 × 10-5 M, and the enhancement factor achieved by the silver nanoparticle film can at least reach to 1.08 × 104. Our experimental results indicate that this technique is promising in the production of large-scale silver nanoparticle films for the surface-enhanced Raman scattering. These may be utilized in biochemical and trace analytical applications.

  17. Amphetamine abuse and intracranial haemorrhage.

    PubMed Central

    Buxton, N; McConachie, N S

    2000-01-01

    Amphetamines taken by any route can cause cerebral vasculitis and intracranial haemorrhage. 8 cases were seen in a neurosurgical unit over 3.5 years. The published work indicates that those who experience these complications, mainly young adults, have poor outcomes. PMID:11089483

  18. Intracranial pressure and skull remodeling

    PubMed Central

    McCulley, Timothy J.; Jordan Piluek, W.; Chang, Jessica

    2014-01-01

    In this article we review bony changes resulting from alterations in intracranial pressure (ICP) and the implications for ophthalmologists and the patients for whom we care. Before addressing ophthalmic implications, we will begin with a brief overview of bone remodeling. Bony changes seen with chronic intracranial hypotension and hypertension will be discussed. The primary objective of this review was to bring attention to bony changes seen with chronic intracranial hypotension. Intracranial hypotension skull remodeling can result in enophthalmos. In advanced disease enophthalmos develops to a degree that is truly disfiguring. The most common finding for which subjects are referred is ocular surface disease, related to loss of contact between the eyelids and the cornea. Other abnormalities seen include abnormal ocular motility and optic atrophy. Recognition of such changes is important to allow for diagnosis and treatment prior to advanced clinical deterioration. Routine radiographic assessment of bony changes may allow for the identification of patient with abnormal ICP prior to the development of clinically significant disease. PMID:25859141

  19. Intracranial haemorrhage and child abuse.

    PubMed

    Cheah, I G; Kasim, M S; Shafie, H M; Khoo, T H

    1994-01-01

    Intracranial haemorrhage is a major cause of severe morbidity and mortality in child abuse cases in developed countries. However, similar data are not available in most developing countries. This study therefore aimed to determine the incidence of intracranial haemorrhage amongst all cases of child physical abuse, the nature of the injuries incurred, and the morbidity and mortality resulting therefrom. Among 369 cases of physical abuse seen over a 4-year period, 41 (11.4%) had intracranial haemorrhage, of whom 37 (90%) were 2 years old or less. A history of trauma was present in only eight (20%), of which only two were compatible with the injuries incurred. Subdural haemorrhages accounted for 80% of the cases, with skull fractures present in only nine cases. Fifty-four per cent of the 37 children aged 2 years of age or less had no external signs of trauma, but 11 of them had retinal haemorrhages. This is in contrast to the children older than 2 years of age who all had external signs of trauma. The overall prognosis was dismal with an early mortality of almost 30% (13 cases) and at least seven cases with severe neurological sequelae. These findings are comparable with studies from developed countries which have established that non-accidental injury must be considered as a cause of intracranial haemorrhage in any young child, despite the absence of external signs of trauma. PMID:7880096

  20. Intracranial Schwannoma in a Cow

    PubMed Central

    Mitcham, S. A.; Kasari, T. R.; Parent, J. M.; Naylor, J. M.

    1984-01-01

    A nine year old Hereford crossbred cow with a history of progressive neurological signs was referred to the Western College of Veterinary Medicine, Saskatoon. A large intracranial mass, histologically identified as a schwannoma, was found to be compressing the left brain stem and appeared to have arisen from the left fifth cranial nerve. ImagesFigure 1.Figure 2.Figure 3. PMID:17422375

  1. Intracranial hypertension: classification and patterns of evolution

    PubMed Central

    Iencean, SM

    2008-01-01

    Intracranial hypertension (ICH) was systematized in four categories according to its aetiology and pathogenic mechanisms: parenchymatous ICH with an intrinsic cerebral cause; vascular ICH, which has its aetiology in disorders of cerebral blood circulation; ICH caused by disorders of cerebro–spinal fluid dynamics and idiopathic ICH. The increase of intracranial pressure is the first to happen and then intracranial hypertension develops from this initial effect becoming symptomatic; it then acquires its individuality, surpassing the initial disease. The intracranial hypertension syndrome corresponds to the stage at which the increased intracranial pressure can be compensated and the acute form of intracranial hypertension is equivalent to a decompensated ICH syndrome. The decompensation of intracranial hypertension is a condition of instability and appears when the normal intrinsic ratio of intracranial pressure – time fluctuation is changed. The essential conditions for decompensation of intracranial hypertension are: the speed of intracranial pressure increase over normal values, the highest value of abnormal intracranial pressure and the duration of high ICP values. Medical objectives are preventing ICP from exceeding 20 mm Hg and maintaining a normal cerebral blood flow. The emergency therapy is the same for the acute form but each of the four forms of ICH has a specific therapy, according to the pathogenic mechanism and if possible to aetiology. PMID:20108456

  2. Magnetic resonance imaging features of intracranial astrocytomas and oligodendrogliomas in dogs.

    PubMed

    Young, Benjamin D; Levine, Jonathan M; Porter, Brian F; Chen-Allen, Annie V; Rossmeisl, John H; Platt, Simon R; Kent, Marc; Fosgate, Geoffrey T; Schatzberg, Scott J

    2011-01-01

    Astrocytomas and oligodendrogliomas represent one third of histologically confirmed canine brain tumors. Our purpose was to describe the magnetic resonance (MR) imaging features of histologically confirmed canine intracranial astrocytomas and oligodendrogliomas and to examine for MR features that differentiate these tumor types. Thirty animals with confirmed astrocytoma (14) or oligodendroglioma (16) were studied. All oligodendrogliomas and 12 astrocytomas were located in the cerebrum or thalamus, with the remainder of astrocytomas in the cerebellum or caudal brainstem. Most (27/30) tumors were associated with both gray and white matter. The signal characteristics of both tumor types were hypointense on T1-weighted images (12 each) and hyperintense on T2-weighted images (11/14 astrocytomas, 12/16 oligodendrogliomas). For astrocytomas and oligodendrogliomas, respectively, common findings were contrast enhancement (10/13, 11/15), ring-like contrast enhancement (6/10, 9/11), cystic regions within the mass (7/14, 12/16), and hemorrhage (4/14, 6/16). Oligodendrogliomas were significantly more likely to contact the brain surface (meninges) than astrocytomas (14/16, 7/14, respectively, P=0.046). Contact with the lateral ventricle was the most common finding, occurring in 13/14 astrocytomas and 14/16 oligodendrogliomas. No MR features were identified that reliably distinguished between these two tumor types. Contrast enhancement was more common in high-grade tumors (III or IV) than low-grade tumors (II, P=0.008). PMID:21388463

  3. Enhancement of strong-field multiple ionization in the vicinity of the conical intersection in 1,3-cyclohexadiene ring opening

    SciTech Connect

    Petrovic, Vladimir S. Kim, Jaehee; Schorb, Sebastian; White, James; Cryan, James P.; Zipp, Lucas; Glownia, J. Michael; Broege, Douglas; Miyabe, Shungo; Tao, Hongli; Martinez, Todd; Bucksbaum, Philip H.

    2013-11-14

    Nonradiative energy dissipation in electronically excited polyatomic molecules proceeds through conical intersections, loci of degeneracy between electronic states. We observe a marked enhancement of laser-induced double ionization in the vicinity of a conical intersection during a non-radiative transition. We measured double ionization by detecting the kinetic energy of ions released by laser-induced strong-field fragmentation during the ring-opening transition between 1,3-cyclohexadiene and 1,3,5-hexatriene. The enhancement of the double ionization correlates with the conical intersection between the HOMO and LUMO orbitals.

  4. Understanding idiopathic intracranial hypertension: mechanisms, management, and future directions.

    PubMed

    Markey, Keira A; Mollan, Susan P; Jensen, Rigmor H; Sinclair, Alexandra J

    2016-01-01

    Idiopathic intracranial hypertension is a disorder characterised by raised intracranial pressure that predominantly affects young, obese women. Pathogenesis has not been fully elucidated, but several causal factors have been proposed. Symptoms can include headaches, visual loss, pulsatile tinnitus, and back and neck pain, but the clinical presentation is highly variable. Although few studies have been done to support evidence-based management, several recent advances have the potential to enhance understanding of the causes of the disease and to guide treatment decisions. Investigators of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) reported beneficial effects of acetazolamide in patients with mild visual loss. Studies have also established weight loss as an effective disease-modifying treatment, and further clinical trials to investigate new treatments are underway. The incidence of idiopathic intracranial hypertension is expected to increase as rates of obesity increase; efforts to reduce diagnostic delays and identify new, effective approaches to treatment will be key to meeting the needs of a growing number of patients. PMID:26700907

  5. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension. PMID:27621920

  6. Saturn's rings

    NASA Technical Reports Server (NTRS)

    2000-01-01

    When seen from the unlit side, the rings of Saturn present a much different appearance from that familiar to telescopic observers. Relatively opaque areas like the B Ring turn black, while lightly populated zones, such as the C Ring and the Cassini Division, prove to excellent diffuse transmitters of sunlight. The A Ring, with intermediate opacity, is at an intermediate level of brightness.

  7. High-resolution Magnetic Resonance Vessel Wall Imaging for Intracranial Arterial Stenosis

    PubMed Central

    Zhu, Xian-Jin; Wang, Wu; Liu, Zun-Jing

    2016-01-01

    Objective: To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis. Date Sources: We retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis. Study Selection: We reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application. Results: VWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy. Conclusions: This review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management. PMID:27231176

  8. Primary intracranial choriocarcinoma: MR imaging findings.

    PubMed

    Lv, X-F; Qiu, Y-W; Zhang, X-L; Han, L-J; Qiu, S-J; Xiong, W; Wen, G; Zhang, Y-Z; Zhang, J

    2010-11-01

    PICCC is the rarest, most malignant primary intracranial GCT. The purpose of this study was to describe and characterize the MR imaging findings in a series of 7 patients (6 males and 1 female; mean age, 11.9 years) with pathologically proved PICCC in our institution from 2004 to 2009. All tumors were located within the pineal (n = 6) or suprasellar (n = 1) regions. On T2-weighted MR imaging, the lesions appeared markedly heterogeneous with areas of both hypointensity and hyperintensity reflecting the histologic heterogeneity, including hemorrhage, fibrosis, cysts, or necrosis. Heterogeneous (n = 7), ringlike (n = 4), and/or intratumoral nodular (n = 3) enhancement was noted on T1-weighted images with gadolinium. These MR imaging findings, combined with patient age and serum β-HCG levels, may prove helpful in distinguishing PICCC from the more common primary brain tumors, thereby avoiding biopsy of this highly vascular tumor. PMID:20616180

  9. Rapid virtual stenting for intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Chen, Danyang; Chen, Zihe; Wang, Xiangyu; Paliwal, Nikhil; Xiang, Jianping; Meng, Hui; Corso, Jason J.; Xu, Jinhui

    2016-03-01

    The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient.

  10. Computed tomography in intracranial supratentorial osteochondroma

    SciTech Connect

    Matz, S.; Israeli, Y.; Shalit, M.N.; Cohen, M.L.

    1981-02-01

    A case of a huge intracranial frontoparietal osteochondroma in a 20-year-old man is reported. The presenting symptoms were headache, vomiting, and blurred vision. Apart from papilledema, no other abnormal neurological signs were present. A specific preoperative diagnosis could not be reached from the information provided by plain skull films, angiography, and radionuclide scan. The findings on computed tomography were those of a high density mass interspersed with small foci of lower densities, producing a honeycomb appearance, and surrounded by deposits of nodular calcification. The postcontrast scan showed a moderate degree of enhancement with preservation of the precontrast honeycomb pattern. These particular features may enable a correct preoperative histological diagnosis to be offered with a high degree of probability.

  11. Rapid Virtual Stenting for Intracranial Aneurysms

    PubMed Central

    Zhao, Liang; Chen, Danyang; Chen, Zihe; Wang, Xiangyu; Paliwal, Nikhil; Xiang, Jianping; Meng, Hui; Corso, Jason J.; Xu, Jinhui

    2016-01-01

    The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient. PMID:27346910

  12. Enhancing the robustness of the equipotential ring of edge termination for 4.5KV IGBT by introducing a Partial N layer

    NASA Astrophysics Data System (ADS)

    Chen, Weizhong; Li, Zehong; Liu, Yong; Zhang, Bo; Liao, Pengfei; Li, Zhaoji

    2014-01-01

    A novel insulated-gate bipolar transistor IGBT featuring a Partial N-Layer is proposed. The static and dynamic processes of the reverse blocking property at room temperature and high temperature for 4.5KV IGBT are investigated. It is discovered that the leakage current crowding in the equipotential ring induced the temperature filament and eventually lead the thermal destruction of the devices. Then a well-designed Partial N-Layer in the active and transition region is introduced to diminish the leakage current and relax electric field in the equipotential ring of edge termination. Simulated and measured results show that the IGBT with Partial N-Layer can enhance the robustness of the edge termination towards reverse voltage biasing not only at room temperature but also at the high temperature comparing with the conventional IGBT.

  13. Intracranial Rosai-Dorfman disease.

    PubMed

    Huang, Bo Yuan; Zong, Miao; Zong, Wen Jing; Sun, Yan Hui; Zhang, Hua; Zhang, Hong Bo

    2016-10-01

    Rosai-Dorfman disease (RDD) is a rare histioproliferative disorder that only occasionally involves the central nervous system. We present the diagnosis and treatment of five patients with intracranial RDD. The patients were preoperatively misdiagnosed as meningioma or eosinophilic granuloma. All five patients were treated by total or subtotal surgical resection and none of them experienced recurrence. Histopathological examination showed a characteristic emperipolesis, the lymphocytes were engulfed in the S-100 protein and CD68 positive histiocytes, with negative expression of CD1a. Preoperative diagnosis of intracranial RDD is still challenging because the lesion is usually a dural-based lesion that mimics a meningioma. Surgical resection is an effective treatment and radiotherapy, steroid and chemotherapy has not demonstrated reliable therapeutic efficiency. PMID:27561856

  14. Isolated sixth nerve palsy secondary to spontaneous intracranial hypotension.

    PubMed

    Khemka, S; Mearza, A A

    2006-11-01

    We report the case of a 43-year-old gentleman who presented with an isolated left sixth nerve palsy in association with postural headache. Magnetic resonance imaging showed dural enhancement with downward displacement of the brainstem. This, in association with the signs, symptoms and findings on lumbar puncture, confirmed the diagnosis of spontaneous intracranial hypotension. Treatment was successful with epidural blood patching. The case is discussed and the relevant literature reviewed. PMID:17038044

  15. Clinical Analysis of Intracranial Hemangiopericytoma

    PubMed Central

    Park, Byoung-Joo; Hong, Yong-Kil; Jeun, Sin-Soo; Lee, Kwan-Sung; Lee, Youn-Soo

    2013-01-01

    Objective Intracranial hemangiopericytomas (HPCs) are rare tumors with aggressive behavior, including local recurrence and distant metastasis. We conducted this retrospective study to evaluate the efficacy of grossly total resection and adjuvant radiotherapy (RT) for these tumors. Methods A total of 13 patients treated for intracranial HPC from January 1995 through May 2013 were included in this retrospective study. We analyzed the clinical presentations, radiologic appearances, treatment results, and follow-up outcomes, as well as reviewed other studies. Results The ages of the patients at the time of diagnosis ranged from 26 to 73 years (mean : 48 years). The majority of the patients were male (92.3%), and the majority of the tumors were located in the parasagittal and falx. The ratio of intracranial HPCs to meningiomas was 13 : 598 in same period, or 2.2%. Seven patients (53.8%) had anaplastic HPCs. Nine patients (69.2%) underwent gross total tumor resection in the first operation without mortality. Eleven patients (84.6%) underwent postoperative adjuvant RT. Follow-up period ranged from 13 to 185 months (mean : 54.3 months). The local recurrence rate was 46.2% (6/13), and there were no distant metastases. The 10-year survival rate after initial surgery was 83.9%. The initial mean Karnofsky performance scale (KPS) was 70.8 and the final mean KPS was 64.6. Conclusion Gross total tumor resection upon initial surgery is very important. We believe that adjuvant RT is helpful even with maximal tumor resection. Molecular biologic analyses and chemotherapy studies are required to achieve better outcomes in recurrent intracranial HPCs. PMID:24294454

  16. Intracranial ependymoma: factors affecting outcome.

    PubMed

    Massimino, Maura; Buttarelli, Francesca R; Antonelli, Manila; Gandola, Lorenza; Modena, Piergiorgio; Giangaspero, Felice

    2009-03-01

    Ependymomas account for 2-9% of all neuroepithelial tumors, amounting to 6-12% of all intracranial tumors in children and up to 30% of those in children younger than 3 years. Recent findings provide evidence that intracranial and spinal ependymomas share similar molecular profiles with the radial glia of their corresponding locations. The management of intracranial ependymoma is still not optimal. The 5-year progression-free survival for children with ependymoma ranges between 30 and 50% with a worse prognosis for patients with residual disease after surgery. The prognostic relevance of most factors are still being debated. Recent studies, in which the current WHO classification criteria were applied, reported the relationship between histological grade and outcome. Biomolecular studies have identified that gain of 1q25 and EGFR overexpression correlate to poor prognosis, whereas low expression of nucleolin correlated with a favorable outcome. Ependymomas have been considered a 'surgical disease', where completeness of excision can be reached in approximately half of the cases. At present the standard treatment is radiation therapy for all patients after gross-total or near-total resection. For high-risk patients, with residual tumor, an interesting, although experimental, approach could be chemotherapy followed by secondary surgery and postoperative conformal irradiation. PMID:19284379

  17. Exploitation of the coffee-ring effect to realize mechanically enhanced inkjet-printed microelectromechanical relays with U-bar-shaped cantilevers

    NASA Astrophysics Data System (ADS)

    Chung, Seungjun; Ul Karim, Muhammed Ahosan; Spencer, Matthew; Kwon, Hyuk-Jun; Grigoropoulos, Costas P.; Alon, Elad; Subramanian, Vivek

    2014-12-01

    We report a mechanically enhanced inkjet-printed microelectromechanical (MEM) relay with a U-bar-shaped cantilever by exploiting the coffee-ring effect. The printed cantilever shape, especially the effective thickness caused by the elevated walls, can be controlled during the drying process by outward convective flow of silver nanoparticles. This enhances mechanical stiffness to efficiently produce a strongly suspended cantilever that is immune to collapse- and curling-related failures. This approach to enhancing cantilever stiffness is unique to printing-based processes using metal-nanoparticle inks and is not feasible for conventional photolithography processes. The resulting printed MEM relays show a pull-in voltage of only 6.6 V and an on/off ratio of 108 with extremely low on-state resistance (˜14.3 Ω) and off-state leakage that is comparable to those of conventional silicon-based MEM relays.

  18. Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  19. Surface-enhanced Raman spectra of medicines with large-scale self-assembled silver nanoparticle films based on the modified coffee ring effect

    PubMed Central

    2014-01-01

    We report here a simple and innovative method to prepare large-scale silver nanoparticle films based on the controlled coffee ring effect. It is demonstrated that the films can be used as surface-enhanced Raman scattering probes to detect low-concentration medicines. Silver nanoparticles with the average size about 70 nm were prepared by reduction of silver nitride. In our experiment, the coffee ring effect was controlled by tilting the substrates during the deposition of silver nanoparticle films. Silver nanoparticle films were spontaneously formed on the surface of silicon substrates at the temperatures about 50°C based on the solvent evaporation and the coffee ring effect. The microstructure of the films was investigated using the scanning electron microscope and atomic force microscope. The surface roughness of the films is found as small as 20 nm. Then, the films were exposed to aqueous solutions of medicine at different concentrations. A comparison with a Raman spectra measured with a conventional Raman spectrometer showed that the Raman signal can be detected in the solution with concentrations as low as 1 × 10−5 M, and the enhancement factor achieved by the silver nanoparticle film can at least reach to 1.08 × 104. Our experimental results indicate that this technique is promising in the production of large-scale silver nanoparticle films for the surface-enhanced Raman scattering. These may be utilized in biochemical and trace analytical applications. PMID:24548639

  20. Enhancement of non-invasive recording of electroenterogram by means of a flexible array of concentric ring electrodes.

    PubMed

    Garcia-Casado, J; Zena-Gimenez, V; Prats-Boluda, G; Ye-Lin, Y

    2014-03-01

    Monitoring intestinal myoelectrical activity by electroenterogram (EEnG) would be of great clinical interest for diagnosing gastrointestinal pathologies and disorders. However, surface EEnG recordings are of very low amplitude and can be severely affected by baseline drifts and respiratory and electrocardiographic (ECG) interference. In this work, a flexible array of concentric ring electrodes was developed and tested to determine whether it can provide surface EEnG signals of better quality than bipolar recordings from conventional disc electrodes. With this aim, sixteen healthy subjects in a fasting state (>8 h) underwent recording. The capability of detecting intestinal pacemaker activity (slow wave) and the influence of physiological interferences were studied. The signals obtained from the concentric ring electrodes proved to be more robust to ECG and respiratory interference than those from conventional disc electrodes. The results also show that intestinal EEnG components such as the slow wave can be more easily identified by the proposed system based on a flexible array of concentric ring electrodes. The developed active electrode array could be a very valuable tool for non-invasive diagnosis of disease states such as ischemia and motility disorders of the small bowel which are known to alter the normal enteric slow wave activity. PMID:24232692

  1. Vascular ring

    MedlinePlus

    ... with aberrant subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... accounts for less than 1% of all congenital heart problems. The condition occurs as often in males ...

  2. Neptune's rings

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  3. Second generation bisheteroarylpiperazine (BHAP) HIV-1 reverse transcriptasae inhibitors: Enhancement of antiviral activity and aqueous solubility via 5- and 6-substitution of the indole ring

    SciTech Connect

    Poel, T.; Thomas, R.C.; Romero, D.L.; Hosley, M.J.; Morge, R.A.; Biles, C.; Reusser, F.; Althaus, I.W.; Schinzer, W.C.; Platzer, D.J.

    1993-12-31

    U-87201E, a potent HIV-1 reverse transcriptase inhibitor (RTI) discovered at Upjohn, is currently in Phase II clinical trials. Additional structure-activity studies have identified second-generation BHAPs with enhanced antiviral activity and improved pharmaceutical properties, notably increased aqueous solubility. Capitalizing on initial SAR studies which demonstrated a tolerance for substitution in the indole ring, a series of BHAPs bearing 5- and 6-substituted indoles was evaluated. Substituents such as ethers, sulfonamides, ureas, and sulfamides containing water-solubilizing groups such as polyethers or basic amines provided highly potent BHAPs with greatly enhanced solubility, such as U-93923. The synthesis, antiviral evaluation and solubility properties of these potent HIV-1 RTIs will be detailed.

  4. Ring finger protein 166 potentiates RNA virus-induced interferon-β production via enhancing the ubiquitination of TRAF3 and TRAF6

    PubMed Central

    Chen, Hai-Wei; Yang, Yong-Kang; Xu, Hao; Yang, Wei-Wei; Zhai, Zhong-He; Chen, Dan-Ying

    2015-01-01

    Host cells orchestrate the production of IFN-β upon detecting invading viral pathogens. Here, we report that Ring finger protein 166 (RNF166) potentiates RNA virus-triggered IFN-β production. Overexpression of RNF166 rather than its homologous proteins RNF114, RNF125, and RNF138, enhanced Sendai virus (SeV)-induced activation of the IFN-β promoter. Knockdown of endogenous RNF166, but not other RNFs, inhibited the IFN-β production induced by SeV and encephalomyocarditis virus. RNF166 interacted with TRAF3 and TRAF6. SeV-induced ubiquitination of TRAF3 and TRAF6 was suppressed when endogenous RNF166 rather than RNF114/138 was knocked down. These findings suggest that RNF166 positively regulates RNA virus-triggered IFN-β production by enhancing the ubiquitination of TRAF3 and TRAF6. PMID:26456228

  5. Intracranial volume in craniosynostotic rabbits.

    PubMed

    Mooney, M P; Burrows, A M; Wigginton, W; Singhal, V K; Losken, H W; Smith, T D; Dechant, J; Towbin, A; Cooper, G M; Towbin, R; Siegel, M I

    1998-05-01

    Although craniosynostosis alters brain growth direction resulting in compensatory changes in the neurocranium, it has been suggested that such compensations occur with little reduction in intracranial volume (ICV). This hypothesis was tested in a rabbit model with nonsyndromic, familial coronal suture synostosis. Cross-sectional three-dimensional computed tomographic head scans were obtained from 79 rabbits (25 normal, 28 with delayed-onset synostosis, and 26 with early-onset synostosis) at 25, 42, and 126 days of age. Intracranial contents were reconstructed and indirect ICV was calculated. Results revealed that by 25 days of age the intracranial contents from early-onset synostosed rabbit skulls showed rostral (anterior) constrictions and a "beaten copper" morphology in the parietal and temporal regions compared with the other two groups. These deformities increased in severity with age. Quantitatively, ICV was significantly reduced (P < 0.05) by 7% in rabbits with early-onset synostosis compared with both control rabbits and rabbits with delayed-onset synostosis at 25 days of age. By 126 days of age, ICV in rabbits with synostosis was significantly reduced (p < 0.05) by 11% in early-onset synostosis and by 8% in delayed-onset synostosis compared with normal rabbits. Results suggest that in rabbits with uncorrected craniosynostosis, compensatory changes in the neurocranium were not adequate to allow normal expansion of the neurocapsular matrix. Further research is needed to determine if ICV reduction is correlated with cerebral atrophy or cerebral spinal fluid (i.e., ventricular or subarachnoid) space compression in this model. PMID:9693554

  6. Transnasal, intracranial penetrating injury treated endoscopically.

    PubMed

    Cetinkaya, Erdem Atalay; Okan, Cinemre; Pelin, Kesapli

    2006-04-01

    Intracranial penetrating injury through the nose is uncommon. We present the case of a four-year-old girl who sustained a transnasal, intracranial penetrating injury with a sharp wooden object. We performed endoscopic removal of the foreign body and repair of the associated cerebrospinal fluid fistula. PMID:16623978

  7. Acute surgical management in idiopathic intracranial hypertension

    PubMed Central

    Zakaria, Zaitun; Fenton, Eoin; Sattar, Muhammad Taufiq

    2012-01-01

    Idiopathic intracranial hypertension is a headache syndrome with progressive symptoms of raised intracranial pressure. Most commonly, it is a slow process where surveillance and medical management are the main treatment modalities. We describe herein an acute presentation with bilateral sixth nerve palsies, papilloedema and visual deterioration, where acute surgical intervention was a vision-saving operation. PMID:23239783

  8. Megadolicho vascular malformation of the intracranial arteries.

    PubMed

    Lodder, J; Janevski, B; van der Lugt, P J

    1981-01-01

    A patient is presented suffering a hemiparesis. Megadolicho-vascular malformation of the intracranial part of the internal carotid arteries and some of its branches and of the basilar artery was suggested by CT and confirmed by angiography. The value of CT compared with angiography in relation to intracranial megadolicho vascular malformations is discussed. PMID:6273040

  9. CO2 Effects in Space: Relationship to Intracranial Hypertension

    NASA Technical Reports Server (NTRS)

    Alexander, David J.

    2011-01-01

    This slide presentation reviews the effects of enhanced exposure to CO2 on Earth and in space. The effects of enhanced exposure to CO2 are experienced in almost all bodily systems. In space some of the effects are heightened due to the fluid shifts to the thorax and head. This fluid shift results in increased intracranial pressure, congested cerebral circulation, increased Cerebral Blood Flow (CBF) and Intravenous dilatation. The mechanism of the effect of CO2 on CBF is diagrammed, as is the Cerebrospinal Fluid (CSF) production. A listing of Neuroendocrine targets is included.

  10. Dabigatran-Associated Intracranial Hemorrhage

    PubMed Central

    Szarlej, Dorota K.; Rincon, Fred

    2015-01-01

    Dabigatran etexilate is an oral direct thrombin inhibitor approved for prevention of stroke and systemic embolization in patients with nonvalvular atrial fibrillation and for the treatment of venous thromboembolism. Although dabigatran has a favorable safety profile, predictable pharmacokinetics, fewer drug interactions than warfarin, and does not require monitoring, clinical data regarding dabigatran reversal are limited. In addition, currently available laboratory assays allow measurement of the presence, but not extent, of dabigatran-associated anticoagulation. Patient age, renal function, weight, concurrent drug therapy, adherence, and concomitant disease states can affect dabigatran’s efficacy and safety. Management of dabigatran-related intracranial hemorrhage must be approached on a case-by-case basis and include assessment of degree of anticoagulation, severity of hemorrhage, renal function, timing of last dabigatran dose, and risk of thromboembolic events. Initial management includes dabigatran discontinuation and general supportive measures. Oral activated charcoal should be administered in those who ingested dabigatran within 2 hours. Four-factor prothrombin complex concentrates (4PCCs), activated PCC, or recombinant activated factor VII use may be reasonable but is not evidence based. Reserve fresh frozen plasma for patients with dilutional coagulopathy. If readily available, hemodialysis should be considered, particularly in patients with advanced kidney injury or excessive risk of thromboembolic events. More clinical studies are needed to determine a standardized approach to treating dabigatran-associated intracranial hemorrhage. Institutional protocol development will facilitate safe, efficacious, and timely use of the limited management options. PMID:26425251

  11. Desmopressin Acetate in Intracranial Haemorrhage

    PubMed Central

    Kapapa, Thomas; Röhrer, Stefan; Struve, Sabine; Petscher, Matthias; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

    2014-01-01

    Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients. PMID:25610644

  12. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Gordon, M. K.; Araki, S.; Black, G. J.; Bosh, A. S.; Brahic, A.; Brooks, S. M.; Charnoz, S.; Colwell, J. E.; Cuzzi, J. N.; Dones, L.; Durisen, R. H.; Esposito, L. W.; Ferrari, C.; Festou, M.; French, R. G.; Giuliatti-Winter, S. M.; Graps, A. L.; Hamilton, D. P.; Horanyi, M.; Karjalainen, R. M.; Krivov, A. V.; Krueger, H.; Larson, S. M.; Levison, H. F.; Lewis, M. C.; Lissauer, J. J.; Murray, C. D.; Namouni, F.; Nicholson, P. D.; Olkin, C. B.; Poulet, F.; Rappaport, N. J.; Salo, H. J.; Schmidt, J.; Showalter, M. R.; Spahn, F.; Spilker, L. J.; Srama, R.; Stewart, G. R.; Yanamandra-Fisher, P.

    2002-08-01

    The past two decades have witnessed dramatic changes in our view and understanding of planetary rings. We now know that each of the giant planets in the Solar System possesses a complex and unique ring system. Recent studies have identified complex gravitational interactions between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto, or collisions between, parent bodies. Yet, as far as we have come, our understanding is far from complete. The fundamental questions confronting ring scientists at the beginning of the twenty-first century are those regarding the origin, age and evolution of the various ring systems, in the broadest context. Understanding the origin and age requires us to know the current ring properties, and to understand the dominant evolutionary processes and how they influence ring properties. Here we discuss a prioritized list of the key questions, the answers to which would provide the greatest improvement in our understanding of planetary rings. We then outline the initiatives, missions, and other supporting activities needed to address those questions, and recommend priorities for the coming decade in planetary ring science.

  13. Evanescent-wave cavity ring-down spectroscopy for enhanced detection of surface binding under flow injection analysis conditions.

    PubMed

    van der Sneppen, L; Buijs, J B; Gooijer, C; Ubachs, W; Ariese, F

    2008-06-01

    The feasibility of liquid-phase evanescent-wave cavity ring-down spectroscopy (EW-CRDS) for surface-binding studies under flow-injection analysis (FIA) conditions is demonstrated. The EW-CRDS setup consists of an anti-reflection coated Dove prism inside a linear cavity (with standard or super-polishing of the total internal reflective (TIR) surface). A teflon spacer with an elliptical hole clamped on this surface acts as a 20 muL sized flow cell. The baseline noise of this system is of the order of 10(-4) absorbance units; the baseline remains stable over a prolonged time and the prism surface does not become contaminated during repeated injections of the reversibly adsorbing test dyes Crystal Violet (CV) and Direct Red 10 (DR10). At typical FIA or liquid chromatography (LC) flow rates, the system has sufficient specificity to discriminate between species with different surface affinities. For CV a much stronger decrease in ring-down time is observed than calculated based on its bulk concentration and the effective depth probed by the evanescent wave, indicating binding of this positively charged dye to the negatively charged prism surface. The amount of adsorption can be influenced by adjusting the flow rate or the eluent composition. At a flow rate of 0.5 mL/min, an enrichment factor of 60 was calculated for CV; for the poorly adsorbing dye DR10 it is 5. Super-polishing of the already polished TIR surface works counter-productively. The adsorbing dye Crystal Violet has a detection limit of 3 muM for the standard polished surface; less binding occurs on the super-polished surface and the detection limit is 5 muM. Possible applications of EW-CRDS for studying surface binding or the development of bio-assays are discussed. PMID:18559152

  14. Sensitivity of Quantified Intracranial Aneurysm Geometry to Imaging Modality

    PubMed Central

    Ramachandran, Manasi; Retarekar, Rohini; Harbaugh, Robert E.; Hasan, David; Policeni, Bruno; Rosenwasser, Robert; Ogilvy, Christopher; Raghavan, Madhavan L.

    2013-01-01

    The objective of this study is to assess the sensitivity of intracranial aneurysm geometry to the modality of imaging. Four imaging modalities—3D rotational angiography (3DRA), computed tomography angiography (CTA), contrast enhanced magnetic resonance angiography (CE-MRA), and time-of-flight magnetic resonance angiography (TOF-MRA)—were assessed using data from a flow phantom and human subjects. A silicone flow phantom of the head and neck arteries with a 10 mm ACOM aneurysm was imaged using all four modalities under steady flow conditions. Three human subjects with mid to large sized intracranial aneurysm who had a 3DRA scan and one of CTA, CE-MRA, or TOF-MRA performed within a day were also studied. The aneurysm and contiguous vasculature were segmented for all available scans and geometric measures of their size (5 indices) and shape (6 indices) were estimated and compared. Visually, the size and shape of segmented 3D models of the aneurysms were similar across scan modalities for both the human subjects and the flow phantom. Consequently, the computed indices were consistent across modalities in the key morphometric indices. In conclusion, quantified indices of 3D geometry of the mid to large sized intracranial aneurysms investigated in this small study population are not sensitive to scanning modality. PMID:24151529

  15. Tuning the voices of a choir: Introducing a new tool to enhance the signals that are stored in tree-ring archives

    NASA Astrophysics Data System (ADS)

    Buras, Allan; van der Maaten, Ernst; Scharnweber, Tobias; Simard, Sonia; Heinrich, Ingo; Helle, Gerd; van der Maaten-Theunissen, Marieke; Eusemann, Pascal; Schnittler, Martin; Wilmking, Martin

    2015-04-01

    Tree-ring based archives, such as ring-width or density, are frequently used proxies for the reconstruction of past environmental parameters at annual resolution (e.g. Fritts, 1976). In terms of tree-ring width based reconstructions, ring-width measurements are usually acquired from several (often at least 20) trees growing under similar conditions (the 'choir') which are then averaged to a so-called master chronology (the 'voice'). Theoretically, this averaging evens out the individual-specific noises that act upon single trees. A statistical measure which frequently has been assumed to reflect the quality of tree-ring based reconstructions is the so-called expressed population signal (EPS, Wigley et al., 1984). Investigators have often sought to maximize EPS independent of individual tree reactions, but rather aiming at large sample sizes, which increase the value of EPS. Although studies have shown that the environmental signal of master chronologies may be enhanced in comparison with single trees (e.g. Carrer, 2011), ecological theory suggests that depending on particular site conditions (e.g. dry vs. wet sites) different trees within populations may react on different environmental drivers. In this context, recent studies have aimed at an individual selection of trees to form groups of similar growth responses (e.g. Piovesan et al., 2008, Walker and Johnstone, 2014). Grouping may help to lower the noise in the resulting averaged chronologies and therefore potentially enhance the strength of the targeted signal further. As a contribution to this particular topic, we present a new methodological approach - the Weighted Principal Component Analysis (WPCA), designed to identify variable growth responses in tree populations. To test its performance, we applied WPCA to various datasets which express different gradients of individual growth responses and compared WPCA to three other statistical approaches which have earlier been used in this context. For all tested

  16. Spontaneous intracranial hypotension: diagnosis to management.

    PubMed

    Limaye, Kaustubh; Samant, Rohan; Lee, Ricky W

    2016-06-01

    Spontaneous Intracranial Hypotension typically occurs from spontaneous CSF leak. CSF volume depletion rather than decrease in CSF pressure is thought to be the main causative feature for intracranial hypotension. More and more cases of intracranial hypotension are getting diagnosed with the advances in the imaging. The advances in the imaging have also led to the better understanding of the dynamic changes that occur with intracranial hypotension. The old theories of CSF overproduction or CSF underproduction have not been substantially associated with intracranial hypotension. It has also led to the fore different atypical clinical features and presentations. Although, it has been known for a long time, the diagnosis is still challenging and dilemma persists over one diagnostic modality over other and the subsequent management. Spontaneous CSF leaks occur at the spinal level and the skull base and other locations are rare. The anatomy of spontaneous intracranial hypotension is a very complex process with significant overlap in connective tissue disorders, previous dural weakness or meningeal diverticula. To localize the location of the CSF leak-CT myelography is the modality of choice. CSF cysternography may provide additional confirmation in uncertain cases and also MRI spine imaging may be of significant help in some cases. Spontaneous intracranial hypotension continues to be a diagnostic dilemma and our effort was to consolidate available information on the clinical features, diagnostics, and management for a practicing neurologist for a "15-20 min quick update of the topic". PMID:26661291

  17. PTFOS: Flexible and Absorbable Intracranial Electrodes for Magnetic Resonance Imaging

    PubMed Central

    Bonmassar, Giorgio; Fujimoto, Kyoko; Golby, Alexandra J.

    2012-01-01

    electrode/trace ink and had similar electrical properties to a standard subdural electrode set. The enhanced image quality could enable routine MRI exams of patients with intracranial electrode implantation and could also lead to chronic implantation solutions. PMID:22984396

  18. Pharmacological management of pain after intracranial surgery.

    PubMed

    Leith, B

    1998-08-01

    Some healthcare professionals continue to believe that patients experience minimal pain and discomfort after intracranial surgery. However, clinical experience indicates that many patients experience significant pain after craniotomy. Despite research which supports the use of morphine as a method of pain control after intracranial surgery, some healthcare professionals continue to administer only codeine, which may be ineffective. Inadequate pain control can be associated with a variety of negative physiological and psychological consequences. Neuroscience nurses are challenged to re-evaluate their current beliefs and practices related to pain and pain control after intracranial surgery. PMID:9791776

  19. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects. PMID:27523417

  20. Intracranial ROSAI-DORFMAN Disease

    PubMed Central

    Mahzoni, Parvin; Zavareh, Mohsen Hani Tabaei; Bagheri, Marzie; Hani, Neda; Moqtader, Babak

    2012-01-01

    Rosai-Dorfman disease is a benign lymphohistiocytosis that often involve lymph nodes and present as massive lymphadenopathy with sinus histiocytosis. The disease is rarely associated with intracranial involvement. Herein, we report a 33-years-old man with recent onset of unconsciousness. According to his past medical history, he was suffering from frontal headache, ataxia and dizziness with no sensory or motor defect since August 2010. At initial work up, MRI showed infiltrating mass in the left parietal region. Microscopically, the mass consisted of infiltration of abundant lymphoplasma cells, neutrophils and some histiocytes scattered in fibrotic background. Emperipolesis (lymphocytophagocytosis) of histiocytic cells made the diagnosis of Rosai-Dorfman disease. Rosai-Dorfman disease should be added in the list of differential diagnosis for a dural mass mimicking meningioma or cerebral mass mimicking glioma, therefore, immunohistochemical staining for EMA, S100 and CD1a should be performed to rule out the differential diagnosis. PMID:23267385

  1. NERF encodes a RING E3 ligase important for drought resistance and enhances the expression of its antisense gene NFYA5 in Arabidopsis

    PubMed Central

    Gao, Wei; Liu, Wenwen; Zhao, Meng; Li, Wen-Xue

    2015-01-01

    NFYA5 is an important drought-stress inducible transcription factor gene that is targeted by miR169 in Arabidopsis. We show here that the cis-natural antisense transcript gene of NFYA5, NFYA5 Enhancing RING FINGER (NERF), can produce siRNAs from their overlapping region (OR) and affect NFYA5 transcripts by functioning together with miR169. The NERF protein functions as an E3 ligase for ubiquitination. Overexpression of NERF or OR cDNA leads to siRNANERF accumulation, miR169 repression, and NFYA5 transcript enhancement; knock-down of NERF transcripts by an artificial miRNA enhances miR169 abundance and reduces NFYA5 transcripts. Overexpression of NFYA5 does not affect the NERF mRNA level. Deep sequencing of the small RNA library from 35S::OR plants identifies 960 sequences representing 323 unique siRNAs that originate from OR; the sequences of some siRNANERF are similar/complementary to those of miR169. Overexpression of the 195- to 280-bp OR cDNA-containing siRNAs similar/complementary to miR169 also leads to the accumulation of NFYA5 transcripts. Analysis of NERF knock-down plants and NERF overexpression lines showed that, like NFYA5, NERF is important for controlling stomatal aperture and drought resistance. This regulatory model might apply to other natural antisense transcripts with positively correlated expression patterns. PMID:25514924

  2. Management of raised intracranial pressure.

    PubMed Central

    Pickard, J D; Czosnyka, M

    1993-01-01

    This review has been written at an unfortunate time. Novel questions are being asked of the old therapies and there is an abundance of new strategies both to lower ICP and protect the brain against cerebral ischaemia. In the United Kingdom, the problem is to ensure that appropriate patients continue to be referred to centres where clinical trials of high quality can be undertaken. One of the success stories of the past decade has been the decline in the number of road accidents as a result of seat belt legislation, improvements in car design and the drink/driving laws. Hence, fortunately there are fewer patients with head injuries to treat and it is even more important that patients are appropriately referred if studies to assess efficacy of the new strategies are not to be thwarted. The nihilistic concept that intensive investigation with ICP monitoring for patients with diffuse head injury or brain swelling following evacuation of a haematoma or a contusion has no proven beneficial effect on outcome, requires revision. A cocktail of therapies may be required that can be created only when patients are monitored in sufficient detail to reveal the mechanisms underlying their individual ICP problem. Ethical problems may arise over how aggressively therapy for intracranial hypertension should be pursued and for how long. There has always been the concern that cranial decompression or prolonged barbiturate coma may preserve patients but with unacceptably severe disability. Some patients may be salvaged from herniating with massive cerebral infarction with the use of osmotherapy but is the outcome acceptable? Similar considerations apply to some children with metabolic encephalopathies. Where such considerations have been scrutinised in patients with severe head injury, the whole spectrum of outcomes appears to be shifted so that the number of severe disabilities and persistent vegetative states are not increased. However, it is important to be sensitive to such issues

  3. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  4. Enhancing production of a 24-membered ring macrolide compound by a marine bacterium using response surface methodology*

    PubMed Central

    Chen, Hua; Wu, Mian-bin; Chen, Zheng-jie; Wang, Ming-lu; Lin, Jian-ping; Yang, Li-rong

    2013-01-01

    A 24-membered ring macrolide compound, macrolactin A has potential applications in pharmaceuticals for its anti-infectious and antiviral activity. In this study, macrolactin A was produced by a marine bacterium, which was identified as Bacillus subtilis by 16S ribosomal RNA (rRNA) sequence analysis. Electrospray ionization mass spectrometry (ESI/MS) and nuclear magnetic resonance (NMR) spectroscopy analyses were used to characterize this compound. To improve the production, response surface methodology (RSM) involving Box-Behnken design (BBD) was employed. Faeces bombycis, the main by-product in sericulture, was used as a nitrogen source in fermentation. The interactions between three significant factors, F. bombycis, soluble starch, and (NH4)2SO4 were investigated. A quadratic model was constructed to fit the production and the factors. Optimum medium composition was obtained by analysis of the model. When cultivated in the optimum medium, the production of macrolactin A was increased to 851 mg/L, 2.7 times as compared to the original. This study is also useful to find another way in utilizing F. bombycis. PMID:23549852

  5. Modification of a commercial cavity ring-down spectroscopy NO{sub 2} detector for enhanced sensitivity

    SciTech Connect

    Castellanos, Patricia; Ehrman, Sheryl H.; Luke, Winston T.; Kelley, Paul; Stehr, Jeffrey W.; Dickerson, Russell R.

    2009-11-15

    Nitrogen dioxide (NO{sub 2}) plays a central role in atmospheric chemistry, air pollution, and biogeochemical cycles. Many analytical techniques have been developed to detect NO{sub 2}, but only chemiluminescence-based instruments are commonly, commercially available. There remains a need for a fast, light, and simple method to directly measure NO{sub 2}. In this work we describe the modification and characterization of a small, commercially available cavity ring-down spectroscopy (CRDS) NO{sub 2} detector suitable for surface and aircraft monitoring. A metal oxide scrubber was added to remove NO{sub 2}, and provide a chemical zero, improving the detection limit (3{sigma} of the background noise) from several parts per billion by volume (ppbv) to 0.06 ppbv, integrated over 60 s. Known interferences by water and particles were removed using Nafion tubing and a 1 {mu}m Teflon filter, respectively. A 95% response time of 18{+-}1 s was observed for a step change in concentration. The CRDS detector was run in parallel to an ozone chemiluminescence device with photolytic conversion of NO{sub 2} to NO. The two instruments measured ambient air in suburban Maryland. A least-squares fit to the comparison data resulted a slope of 0.960{+-}0.002 and R of 0.995, showing agreement within experimental uncertainty.

  6. [Intracranial pressure changes during xenon anesthesia in neurosurgical patients without intracranial hypertention].

    PubMed

    Rylova, A V; Lubnin, A Iu

    2011-01-01

    Xenon assures rapid awakening and stable hemodynamics, it also has some neuroprotective effect. This is the reason why it may become an anesthetic of choice in neurosurgery. Still there is little and controversial data on its impact upon ICP. This is the first study of xenon effect upon intracranial pressure, cerebral perfusion pressure and cerebrovascular reactivity during xenon anesthesia in neurosurgical patients without intracranial hypertension. We report a slight increase in intracranial and a slight decrease in cerebral perfusion pressure during xenon anesthesia and show that cerebrovascular reactivity is preserved. Thus we conclude that xenon anesthesia is safe for neurosurgical patients without intracranial hypertension. PMID:21957614

  7. Remotely-powered intracranial pressure monitor

    NASA Technical Reports Server (NTRS)

    Fryer, T. B.

    1979-01-01

    Implantable RF powered monitor uses capacitive transducer and stiff metal diaphragm that gives high stability for long term intracranial pressure monitoring. Design of monitor reduces risk of infection while improving patient comfort and mobility.

  8. Intracranial complications of transorbital stab wounds.

    PubMed Central

    De Villiers, J C; Sevel, D

    1975-01-01

    Oscular and orbital injuries due to stab wounds may mask underlying serious intracranial damage. The correct clinical assessment and treatment of such cases require the attention of a team comprising a neurosurgeon, ophthalmologist, otolaryngologist, and plastic surgeon. Images PMID:1125159

  9. Intracranial aneurysms: analysis of results of microneurosurgery.

    PubMed Central

    Adams, C B; Loach, A B; O'laoire, S A

    1976-01-01

    Subarachnoid haemorrhage from intracranial aneurysms has a poor prognosis. Operative management of intracranial aneurysms was once considered ineffective. The first 100 cases treated by micorsurgery were analysed to see whether mortality and morbidity were reduced. Modern surgical techniques halved the total mortality but the morbidity was unaltered. Results can be improved by delaying surgery seven days and by treating any hypertension before surgery. PMID:963461

  10. Perspective: Update on Idiopathic Intracranial Hypertension

    PubMed Central

    Bruce, Beau B.; Biousse, Valérie; Newman, Nancy J.

    2011-01-01

    Purpose Provide an update on various features of idiopathic intracranial hypertension. Design Perspective. Methods Selected articles on the epidemiology, clinical and imaging features, natural history, pathophysiology, and treatment of idiopathic intracranial hypertension were reviewed and interpreted in the context of the authors’ clinical and research experience. Results Idiopathic intracranial hypertension is primarily a disease of obese women of childbearing age, but it can affect patients of any weight, sex, and age. Although a relatively rare disorder, idiopathic intracranial hypertension’s associated costs in the U.S. entail hundreds of millions of dollars. Even following treatment, headaches are frequently persistent and may require the continued involvement of a neurologist. Quality of life reductions and depression are common among idiopathic intracranial hypertension patients. However, visual dysfunction, especially visual field abnormalities, represents the major morbidity of this disorder, and serial automated perimetry remains the primary mode of patient monitoring. Patients who are men, black, very obese, or anemic are at higher risk of visual loss. Vitamin A metabolism, adipose tissue as an actively secreting endocrine tissue, and cerebral venous abnormalities are areas of active study regarding idiopathic intracranial hypertension’s pathophysiology. Treatment studies show that lumbar puncture is a valuable treatment (in addition to its crucial diagnostic role) and that weight management is critical. However, open questions remain regarding the efficacy of acetazolamide, CSF diversion procedures, and cerebral venous stenting. Conclusions Many questions remain unanswered about idiopathic intracranial hypertension. Ongoing studies, especially an ongoing NIH-funded clinical trial of acetazolamide, should provide more insight into this important, yet poorly understood syndrome of isolated intracranial hypertension. PMID:21696699

  11. Evaluation of Image-Guided Positioning for Frameless Intracranial Radiosurgery

    SciTech Connect

    Lamba, Michael Breneman, John C.; Warnick, Ronald E.

    2009-07-01

    Purpose: The standard for target alignment and immobilization in intracranial radiosurgery is frame-based alignment and rigid immobilization using a stereotactic head ring. Recent improvements in image-guidance systems have introduced the possibility of image-guided radiosurgery with nonrigid immobilization. We present data on the alignment accuracy and patient stability of a frameless image-guided system. Methods and Materials: Isocenter alignment errors were measured for in vitro studies in an anthropomorphic phantom for both frame-based stereotactic and frameless image-guided alignment. Subsequently, in vivo studies assessed differences between frame-based and image-guided alignment in patients who underwent frame-based intracranial radiosurgery. Finally, intratreatment target stability was determined by image-guided alignment performed before and after image-guided mask immobilized radiosurgery. Results: In vitro hidden target localization errors were comparable for the framed (0.7 {+-} 0.5 mm) and image-guided (0.6 {+-} 0.2 mm) techniques. The in vivo differences in alignment were 0.9 {+-} 0.5 mm (anteroposterior), -0.2 {+-} 0.4 mm (superoinferior), and 0.3 {+-} 0.5 mm (lateral). For in vivo stability tests, the mean distance differed between the pre- and post-treatment positions with mask-immobilized radiosurgery by 0.5 {+-} 0.3 mm. Conclusion: Frame-based and image-guided alignment accuracy in vitro was comparable for the system tested. In vivo tests showed a consistent trend in the difference of alignment in the anteroposterior direction, possibly due to torque to the ring and mounting system with frame-based localization. The mask system as used appeared adequate for patient immobilization.

  12. [Dynamic MRA in the evaluation of intracranial vascular diseases].

    PubMed

    Gauvrit, J Y; Oppenheim, C; Savage, J; Nataf, F; Reyns, N; Pruvo, J P; Meder, J F; Leclerc, X

    2005-01-01

    Conventional catheter angiography (CCA) remains the gold standard for the evaluation of most intracranial vascular malformations. MRA techniques such as Time of Flight, Phase Contrast or 3D contrast-enhanced MRA, provide anatomic evaluation but without hemodynamic information. Recently developed, dynamic MRA is based on dynamic acquisition of images and image subtraction; these two principal characteristics produce images comparable to those obtained by CCA. The purpose of this review is to explain the principles, advantages and drawbacks of this technique in the evaluation of arteriovenous malformations, arteriovenous fistulas, aneurysms and venous thrombosis. PMID:15798609

  13. Intracranial Rhabdomyoma: Case Report and Review of the Literature

    PubMed Central

    Santiago-Dieppa, David R; Zhou, Tianzan; Jones, Karra A; Chen, James Y; Hansen, Lawrence; U, Hoi Sang

    2016-01-01

    A 24-year-old male presented with eight months of increasingly severe frontal headaches, decreased right facial sensation, and periodic vertigo. Magnetic resonance imaging demonstrated a heterogeneously contrast-enhancing mass involving and expanding the right foramen ovale.  A biopsy of the lesion was performed, and the final pathologic diagnosis revealed a neoplastic rhabdomyoma. To date, only five cases of intracranial rhabdomyoma have been reported, and a rhabdomyoma involving the trigeminal nerve has never been described in an adult. This manuscript reviews the available literature and highlights the clinical, imaging, pathologic characteristics, and surgical management of these exceedingly rare lesions. PMID:27335706

  14. Computed tomographic spectrum of intracranial mycosis: correlation with histopathology

    SciTech Connect

    Whelan, M.A.; Stern, J.; deNapoli, R.A.

    1981-12-01

    Four cases of intracerebral fungal infection are reviewed. The clinical course is outlined, and the computed tomographic (CT) characteristics are analyzed in light of known pathological data. The CT appearance of intracranial mycosis is dependent on the type of fungus as well as the dominant infecting form, i.e., yeast or hyphae. The hyphal form leads predominantly to a CT pattern consistent with vascular occlusion and secondary abscess formation; the yeast form generally results in noncaseating granulomas, which appear on CT scan as nodular enhancing lesions. If the patient survives the acute infective process, these fungal lesions undergo a prolonged subacute phase, and may eventually calcify.

  15. Uranus rings and two moons

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Voyager 2 has discovered two 'shepherd' satellites associated with the rings of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon ring appears surrounded by a dark halo as a result of this processing; occasional blips seen on the ring are also artifacts. Lying inward from the epsilon ring are the delta, gamma and eta rings; then the beta and alpha rings; and finally the barely visible 4, 5 and 6 rings. The rings have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine rings in reflected sunlight. They range in width from about 100 km (60 mi) at the widest part of the epsilon ring to only a few kilometers for most of the others. The discovery of the two ring moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian rings and is in good agreement with theoretical predictions of how these narrow rings are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  16. Vascular rings.

    PubMed

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K

    2016-06-01

    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. PMID:27301603

  17. Petrous apex cephalocoele: contribution of coexisting intracranial pathologies to the aetiopathogenesis

    PubMed Central

    Duran, S; Hatipoglu, H G; Cılız, D S; Elverici, E; Sakman, B

    2015-01-01

    Objective: The aim of this study was to show the MRI findings of petrous apex cephalocoele (PAC) and the other intracranial pathologies that coexist with PAC, and to discuss the contribution of the co-existing pathologies to aetiopathogenesis. Methods: A retrospective analysis of our imaging archive for the period from January 2012 to October 2013 revealed 13 patients with PAC (12 females and 1 male; age range, 26–69 years). 11 patients underwent MRI examination of the cranium, and 2 patients underwent MRI examination of the sellar region. We evaluated the lesions for content, signal intensity, enhancement, relation to petrous apex and Meckel's cave. Images were also evaluated for coexisting pathologies. Results: The presenting symptoms included headache, vertigo, cerebrospinal fluid (CSF) leak and trigeminal neuropathy. All patients had PAC. All lesions were located posterolateral to the Meckel's cave and were isointense with CSF signal on all pulse sequences. All lesions were continuous with Meckel's cave. Coexisting pathologies included intracranial aneurysmal dilatation, empty sella, mass in hypophysis, arachnoid cyst, inferior herniation of parahippocampal gyrus and optic nerve sheath CSF distension. Conclusion: Coexistence with other intracranial pathologies supports the possibility of CSF imbalance and/or intracranial hypertension in the aetiopathogenesis of PAC. Advances in knowledge: This study examined the contribution of the co-existing intracranial pathologies to the aetiopathogenesis of PAC. PMID:25651410

  18. Cortical astrogliosis and increased perivascular aquaporin-4 in idiopathic intracranial hypertension.

    PubMed

    Eide, Per Kristian; Eidsvaag, Vigdis Andersen; Nagelhus, Erlend A; Hansson, Hans-Arne

    2016-08-01

    The syndrome idiopathic intracranial hypertension (IIH) includes symptoms and signs of raised intracranial pressure (ICP) and impaired vision, usually in overweight persons. The pathogenesis is unknown. In the present prospective observational study, we characterized the histopathological changes in biopsies from the frontal brain cortical parenchyma obtained from 18 IIH patients. Reference specimens were sampled from 13 patients who underwent brain surgery for epilepsy, tumors or acute vascular diseases. Overnight ICP monitoring revealed abnormal intracranial pressure wave amplitudes in 14/18 IIH patients, who underwent shunt surgery and all responded favorably. A remarkable histopathological observation in IIH patients was patchy astrogliosis defined as clusters of hypertrophic astrocytes enclosing a nest of nerve cells. Distinct astrocyte domains (i.e. no overlap between astrocyte processes) were lacking in most IIH biopsy specimens, in contrast to their prevalence in reference specimens. Evidence of astrogliosis in IIH was accompanied with significantly increased aquaporin-4 (AQP4) immunoreactivity over perivascular astrocytic endfeet, compared to the reference specimens, measured with densitometry. Scattered CD68 immunoreactive cells (activated microglia and macrophages) were recognized, indicative of some inflammation. No apoptotic cells were demonstrable. We conclude that the patchy astrogliosis is a major finding in patients with IIH. We propose that the astrogliosis impairs intracranial pressure-volume reserve capacity, i.e. intracranial compliance, and contributes to the IIH by restricting the outflow of fluid from the cranium. The increased perivascular AQP4 in IIH may represent a compensatory mechanism to enhance brain fluid drainage. PMID:27188961

  19. Intracranial Vasospasm without Intracranial Hemorrhage due to Acute Spontaneous Spinal Subdural Hematoma

    PubMed Central

    Oh, Jung-Hwan; Jwa, Seung-Joo; Yang, Tae Ki; Lee, Chang Sub; Oh, Kyungmi

    2015-01-01

    Spontaneous spinal subdural hematoma (SDH) is very rare. Furthermore, intracranial vasospasm (ICVS) associated with spinal hemorrhage has been very rarely reported. We present an ICVS case without intracranial hemorrhage following SDH. A 41-year-old woman was admitted to our hospital with a complaint of severe headache. Multiple intracranial vasospasms were noted on a brain CT angiogram and transfemoral cerebral angiography. However, intracranial hemorrhage was not revealed by brain MRI or CT. On day 3 after admission, weakness of both legs and urinary incontinence developed. Spine MRI showed C7~T6 spinal cord compression due to hyperacute stage of SDH. After hematoma evacuation, her symptoms gradually improved. We suggest that spinal cord evaluation should be considered in patients with headache who have ICVS, although intracranial hemorrhage would not be visible in brain images. PMID:26713084

  20. Simultaneous Spinal and Intracranial Chronic Subdural Hematoma Cured by Craniotomy and Laminectomy: A Video Case Report

    PubMed Central

    Kanamaru, Hideki; Kanamaru, Kenji; Araki, Tomohiro; Hamada, Kazuhide

    2016-01-01

    Simultaneous spinal and intracranial chronic subdural hematoma (CSDH) is a rare entity. A 67-year-old man visited our hospital due to headache after diving into a river 2 weeks before. Non-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed bilateral intracranial CSDH. The bilateral CSDH was evacuated and his symptoms improved. Three days after craniotomy, he complained of sensory disturbance on his buttocks. Lumbar MRI showed a space-occupying lesion behind the thecal sac at L5. CT with myelography showed a subdural mass lesion; there was no communication with the subarachnoid space. Fourteen days after craniotomy, L5 laminectomy was performed and the dura mater was incised carefully. The video shows that a liquid hematoma similar to the intracranial CSDH flowed out, followed by cerebrospinal fluid. His symptoms improved after the operation and the hematoma did not recur. This is a rare condition of spinal CSDH demonstrated by neuroimaging and intraoperative video. PMID:27194987

  1. Simultaneous Spinal and Intracranial Chronic Subdural Hematoma Cured by Craniotomy and Laminectomy: A Video Case Report.

    PubMed

    Kanamaru, Hideki; Kanamaru, Kenji; Araki, Tomohiro; Hamada, Kazuhide

    2016-01-01

    Simultaneous spinal and intracranial chronic subdural hematoma (CSDH) is a rare entity. A 67-year-old man visited our hospital due to headache after diving into a river 2 weeks before. Non-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed bilateral intracranial CSDH. The bilateral CSDH was evacuated and his symptoms improved. Three days after craniotomy, he complained of sensory disturbance on his buttocks. Lumbar MRI showed a space-occupying lesion behind the thecal sac at L5. CT with myelography showed a subdural mass lesion; there was no communication with the subarachnoid space. Fourteen days after craniotomy, L5 laminectomy was performed and the dura mater was incised carefully. The video shows that a liquid hematoma similar to the intracranial CSDH flowed out, followed by cerebrospinal fluid. His symptoms improved after the operation and the hematoma did not recur. This is a rare condition of spinal CSDH demonstrated by neuroimaging and intraoperative video. PMID:27194987

  2. [Case of intracranial hypotension responsive to oral prednisolone].

    PubMed

    Sakajiri, Kenichi; Ohtaki, Michiyo; Yoshinaga, Tomofumi; Uchiyama, Shinji

    2006-06-01

    A 31-year-old female patient with headache and nausea was admitted to our hospital, although there were no apparent neurological abnormalities except headache. Cerebrospinal fluid (CSF) pressure was 40 mmH2O on the first lumbar puncture and CT showed some fluid in the left maxillary sinus. She gradually developed orthostatic headache despite antibiotics, hydration and analgesics. MRI showed diffuse meningeal thickening and enhancement. CSF pressure was 0 mmH2O on the second lumbar puncture and RI cisternography demonstrated early excretion to the kidneys. She was diagnosed with intracranial hypotension due to CSF leakage. An autologous 10ml blood patch on the lumbar epidural space did not relieve the orthostatic headache. However, headache disappeared one day after oral intake of 40mg prednisolone. During the next three months, oral prednisolone was tapered off. Three months after the onset of the illness, MRI did not show either meningeal thickening or enhancement. We concluded that oral prednisolone was effective in a case of intracranial hypotension. PMID:16986700

  3. Hyperprolactinemia due to spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Nuño, Miriam; Rozen, Todd D; Maya, M Marcel; Mamelak, Adam N; Carmichael, John; Bonert, Vivien S

    2015-05-01

    OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia. PMID:25380110

  4. Primary Stenting of Intracranial Atherosclerotic Stenoses

    SciTech Connect

    Straube, T. Stingele, Robert; Jansen, Olav

    2005-04-15

    Purpose: To determine the feasibility and safety of stenting intracranial atherosclerotic stenoses.Methods: In 12 patients the results of primary intracranial stenting were evaluated retrospectively. Patient ages ranged from 49 to 79 years (mean 64 years). Six patients presented with stenoses in the anterior circulation, and six had stenosis in the posterior circulation. One patient presented with extra- and intracranial tandem stenosis of the left internal carotid artery. Three patients presented with acute basilar thrombosis, caused by high-grade basilar stenoses.Results: Intracranial stenoses were successfully stented in 11 of 12 patients. In one patient the stent could not be advanced over the carotid siphon to reach the stenosis of the ophthalmic internal carotid artery. Follow-up digital subtraction angiographic studies were obtained in two patients who had presented with new neurologic signs or symptoms. In both cases the angiogram did not show any relevant stenotic endothelial hyperplasia. In one patient, after local thrombolysis the stenosis turned out to be so narrow that balloon angioplasty had to be performed before stent deployment. All three patients treated for stenosis-related basilar thrombosis died due to brainstem infarction that had ensued before the intervention.Conclusions: Prophylactic primary stenting of intracranial stenoses of the anterior or posterior cerebral circulation can be performed with a low complication rate; technical problems such as stent flexibility must still be solved. Local thrombolysis followed by stenting in stenosis-related thrombotic occlusion is technically possible.

  5. Storage Rings

    SciTech Connect

    Fischer, W.

    2011-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10{sup -6} eV to 3.5 x 10{sup 12} eV (LHC, 7 x 10{sup 12} eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or

  6. [Suppurative intracranial infections in Africa].

    PubMed

    Loembe, P M; Okome-Kouakou, M; Alliez, B

    1997-01-01

    The purpose of this study was to review recent African literature on suppurative intracranial infection and its implications for neurosurgery. In order of decreasing frequency the main lesions are brain abscess, subdural empyema, and epidural abscess. Despite progress in diagnostic imaging and availability of antibiotic therapy, these lesions still cause disturbingly high morbidity and mortality especially in sub-Saharan Africa where diagnosis is often delayed. The male-to-female ratio was 3.6:1 and 70 to 80% of patients were under the age of 20 years. Spread from the paranasal sinus or ear was the most common mechanism of infection. Hematogenous processes accounted for 22% of cases and the origin was undetermined in 11% to 26% of cases. Staphylococcus aureus and enteric gram-negative bacilli were the most common bacteria identified but cultures were reported as sterile in 30% to 50% of cases. While ultrasonography can be useful in newborns with an open fontanelle, arteriography is often the only feasible procedure for diagnosis in Black Africa. The diagnostic modality of choice is computed tomography which allows precise mapping prior to neurosurgery. Introduction of computed tomography in some African cities has led to a decrease in mortality ranging from 4.7% to 43%. The most effective treatment is a combination of appropriate antimicrobial therapy and surgical decompression of expanding lesions. The main procedures are aspiration through burr holes and craniotomy. Use of this combined strategy requires close cooperation between the neurosurgeon, infectious disease specialist, and microbiologist. Therapeutic indications are discussed within the context of Black Africa. PMID:9304016

  7. Novel nitrogen-enriched oridonin analogues with thiazole-fused A-ring: protecting group-free synthesis, enhanced anticancer profile, and improved aqueous solubility.

    PubMed

    Ding, Chunyong; Zhang, Yusong; Chen, Haijun; Yang, Zhengduo; Wild, Christopher; Chu, Lili; Liu, Huiling; Shen, Qiang; Zhou, Jia

    2013-06-27

    Oridonin (1), a complex ent-kaurane diterpenoid isolated from the traditional Chinese herb Isodon rubescens , has demonstrated great potential in the treatment of various human cancers due to its unique and safe anticancer pharmacological profile. Nevertheless, the clinical development of oridonin for cancer therapy has been hampered by its relatively moderate potency, limited aqueous solubility, and poor bioavailability. Herein, we report the concise synthesis of a series of novel nitrogen-enriched oridonin derivatives with thiazole-fused A-ring through an efficient protecting group-free synthetic strategy. Most of them, including compounds 7-11, 13, and 14, exhibited potent antiproliferative effects against breast, pancreatic, and prostate cancer cells with low micromolar to submicromolar IC50 values as well as markedly enhanced aqueous solubility. These new analogues obtained by rationally modifying the natural product have been demonstrated not only to significantly induce the apoptosis and suppress growth of triple-negative MDA-MB-231 breast cancer both in vitro and in vivo but also effective against drug-resistant ER-positive MCF-7 clones. PMID:23746196

  8. Amino-Functionalized Multiwalled Carbon Nanotubes Lead to Successful Ring-Opening Polymerization of Poly(ε-caprolactone): Enhanced Interfacial Bonding and Optimized Mechanical Properties.

    PubMed

    Roumeli, Eleftheria; Papageorgiou, Dimitrios G; Tsanaktsis, Vasilios; Terzopoulou, Zoe; Chrissafis, Konstantinos; Avgeropoulos, Apostolos; Bikiaris, Dimitrios N

    2015-06-01

    In this work, the synthesis, structural characteristics, interfacial bonding, and mechanical properties of poly(ε-caprolactone) (PCL) nanocomposites with small amounts (0.5, 1.0, and 2.5 wt %) of amino-functionalized multiwalled carbon nanotubes (f-MWCNTs) prepared by ring-opening polymerization (ROP) are reported. This method allows the creation of a covalent-bonding zone on the surface of nanotubes, which leads to efficient debundling and therefore satisfactory dispersion and effective load transfer in the nanocomposites. The high covalent grafting extent combined with the higher crystallinity provide the basis for a significant enhancement of the mechanical properties, which was detected in the composites with up to 1 wt % f-MWCNTs. Increasing filler concentration encourages intrinsic aggregation forces, which allow only minor grafting efficiency and poorer dispersion and hence inferior mechanical performance. f-MWCNTs also cause a significant improvement on the polymerization reaction of PCL. Indeed, the in situ polymerization kinetics studies reveal a significant decrease in the reaction temperature, by a factor of 30-40 °C, combined with accelerated the reaction kinetics during initiation and propagation and a drastically reduced effective activation energy. PMID:25950403

  9. The RING Finger Ubiquitin E3 Ligase OsHTAS Enhances Heat Tolerance by Promoting H2O2-Induced Stomatal Closure in Rice.

    PubMed

    Liu, Jianping; Zhang, Cuicui; Wei, Chuchu; Liu, Xin; Wang, Mugui; Yu, Feifei; Xie, Qi; Tu, Jumin

    2016-01-01

    Heat stress often results in the generation of reactive oxygen species, such as hydrogen peroxide, which plays a vital role as a secondary messenger in the process of abscisic acid (ABA)-mediated stomatal closure. Here, we characterized the rice (Oryza sativa) HEAT TOLERANCE AT SEEDLING STAGE (OsHTAS) gene, which plays a positive role in heat tolerance at the seedling stage. OsHTAS encodes a ubiquitin ligase localized to the nucleus and cytoplasm. OsHTAS expression was detected in all tissues surveyed and peaked in leaf blade, in which the expression was concentrated in mesophyll cells. OsHTAS was responsive to multiple stresses and was strongly induced by exogenous ABA. In yeast two-hybrid assays, OsHTAS interacted with components of the ubiquitin/26S proteasome system and an isoform of rice ascorbate peroxidase. OsHTAS modulated hydrogen peroxide accumulation in shoots, altered the stomatal aperture status of rice leaves, and promoted ABA biosynthesis. The results suggested that the RING finger ubiquitin E3 ligase OsHTAS functions in leaf blade to enhance heat tolerance through modulation of hydrogen peroxide-induced stomatal closure and is involved in both ABA-dependent and DROUGHT AND SALT TOLERANCE-mediated pathways. PMID:26564152

  10. Monitoring intracranial pressure based on F-P

    NASA Astrophysics Data System (ADS)

    Cai, Ting; Tong, Xinglin; Chen, Guangxi

    2013-09-01

    Intracranial pressure is an important monitoring indicator of neurosurgery. In this paper we adopt all-fiber FP fiber optic sensor, using a minimally invasive operation to realize real-time dynamic monitoring intracranial pressure of the hemorrhage rats, and observe their intracranial pressure regularity of dynamic changes. Preliminary results verify the effectiveness of applications and feasibility, providing some basis for human brain minimally invasive intracranial pressure measurement.

  11. Intracranial Hypertension Without Papilledema in Children.

    PubMed

    Aylward, Shawn C; Aronowitz, Catherine; Roach, E Steve

    2016-02-01

    This study aims to determine the frequency of intracranial hypertension without papilledema in children. Charts of patients evaluated in a pediatric intracranial hypertension clinic at our institution were retrospectively reviewed. The patients were divided into 2 groups depending on whether they had presence or absence of optic nerve edema at the time of presentation. Age, body mass index, and opening cerebrospinal fluid pressures were considered continuous variables and compared by Wilcoxon rank sum test because of non-normality. A P-value of 0.05 was considered significant. A total of 228 charts were reviewed; 152 patients met the criteria for intracranial hypertension, and 27 patients (17.8%) met the criteria of headache without optic nerve edema. There was no clinically significant difference in age, body mass index, opening pressure, and modified opening pressure between the 2 groups. PMID:26012507

  12. An Update on Idiopathic Intracranial Hypertension

    PubMed Central

    Thurtell, Matthew J.; Bruce, Beau B.; Newman, Nancy J.; Biousse, Valérie

    2013-01-01

    Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology often encountered in neurologic practice. It produces non-localizing symptoms and signs of raised intracranial pressure and, when left untreated, can result in severe irreversible visual loss. It most commonly occurs in obese women of childbearing age, but it can also occur in children, men, non-obese adults, and older adults. While it is frequently associated with obesity, it can be associated with other conditions, such as obstructive sleep apnea and transverse cerebral venous sinus stenoses. Recent identification of subgroups at high risk for irreversible visual loss, including black patients, men, and patients with fulminant forms of IIH, help guide the optimal management and follow-up. Ongoing studies of venous anatomy and physiology in IIH patients, as well as a recently begun randomized clinical treatment trial, should provide more insights into this common yet poorly understood syndrome of isolated intracranial hypertension. PMID:20944524

  13. Spectral Imaging for Intracranial Stents and Stent Lumen

    PubMed Central

    Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

    2016-01-01

    Introduction Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. Materials and Methods In vitro, we scanned Enterprise stent phantom and a stent–cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. Results In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P < .05) and showed the highest mean grading score (2.94 ± 0.94; P < .05) and contrast/noise ratio of in-stent lumen (160.03 ±37.79; P < .05) among all the modes. Conclusion Iodine (water) images can help reduce stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis. PMID:26731534

  14. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets. PMID:10325220

  15. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  16. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  17. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  18. Spontaneous intracranial hypotension syndrome treated with fludrocortisone.

    PubMed

    Rizk, Marwan; El Khatib, Mohammad; Yamout, Bassem; Hujeily, Elissar; Ayoub, Sophie; Ayoub, Chakib; Skaf, Ghassan

    2015-01-01

    Spontaneous intracranial hypotension is a rare syndrome characterized by orthostatic headache not associated with trauma or dural puncture. In most cases, it is caused by a spontaneous spinal cerebrospinal fluid leakage as demonstrated by neuroradiological studies. The standard of care consists of conservative treatment including bed rest, hydration, and administration of caffeine or glucocorticoids. When such conservative therapy fails, an epidural blood patch is recommended. In this report, we describe the treatment of 2 patients with spontaneous intracranial hypotension who failed conservative treatment and went on to have complete and sustained resolution of their symptoms after the administration of oral fludrocortisone. PMID:25612272

  19. Measuring Intracranial Pressure And Volume Noninvasively

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.; Yost, William T.

    1994-01-01

    Ultrasonic technique eliminates need to drill into brain cavity. Intracranial dynamics instrument probes cranium ultrasonically to obtain data for determination of intracranial pressure (ICP) and pressure-volume index (PVI). Instrument determines sensitivity of skull to changes in pressure and by use of mechanical device to exert external calibrated pressure on skull. By monitoring volume of blood flowing into jugular vein, one determines change of volume of blood in cranial system. By measuring response of skull to increasing pressure (where pressure increased by tilting patient known amount) and by using cranial blood pressure, one determines intial pressure in cerebrospinal fluid. Once PVI determined, ICP determined.

  20. Simulation of the human intracranial arterial tree.

    PubMed

    Grinberg, Leopold; Anor, Tomer; Cheever, Elizabeth; Madsen, Joseph R; Karniadakis, George Em

    2009-06-13

    High-resolution unsteady three-dimensional flow simulations in large intracranial arterial networks of a healthy subject and a patient with hydrocephalus have been performed. The large size of the computational domains requires the use of thousands of computer processors and solution of the flow equations with approximately one billion degrees of freedom. We have developed and implemented a two-level domain decomposition method, and a new type of outflow boundary condition to control flow rates at tens of terminal vessels of the arterial network. In this paper, we demonstrate the flow patterns in the normal and abnormal intracranial arterial networks using patient-specific data. PMID:19414460

  1. Ring Galaxies

    NASA Astrophysics Data System (ADS)

    Dennefeld, M.; Materne, J.

    1980-09-01

    Among the 338 exotic, intriguing and/or fascinating objects contained in Arp's catalogue of peculiar galaxies, two, Arp 146 and 147, are calling special attention as a presumably separate class of objects displaying closed rings with almost empty interior. It is difficult to find out when, historically speaking, attention was called first to this type of object as a peculiar class, but certainly ga1axies with rings were widely found and recognized in the early sixties, ul}der others by Vorontsov-Velyaminov (1960), Sandage (1961) in the Hubble Atlas or de Vaucouleurs (1964) in the first reference catalogue of ga1axies. The most recent estimates by Arp and Madore (1977) from a search on about 200 Schmidt plates covering 7,000 square degrees give 3.6 per cent of ring galaxies among 2,784 peculiar galaxies found. However, despite the mythological perfection associated with a circle, some ordering is necessary before trying to understand the nature of such objects. This is particularly true because a large fraction of those galaxies with rings are probably normal spiral galaxies of type RS or S(r) as defined by de Vaucouleurs, where the spiral arms are simply "closing the circle". A good example of such "ordinary" galaxy is NGC 3081 in the Hubble Atlas .

  2. Deployable Fresnel Rings

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  3. [Factor VII deficiency revealed by intracranial hemorrhage].

    PubMed

    Sfaihi Ben Mansour, L; Thabet, A; Aloulou, H; Turki, H; Chabchoub, I; Mhiri, F; Mnif, Z; Ben Ali, H; Kammoun, T; Hachicha, M

    2009-07-01

    Constitutional factor VII deficiency is a hereditary disease with recessive autosomic transmission. Its incidence is estimated to be 1/1,000,000 in the general population. We report a case of severe factor VII deficiency in infancy revealed by an intracranial hemorrhage in a 2-month-old infant. We describe the clinical, biological and therapeutic characteristics of this disease. PMID:19409767

  4. CSF imaging in benign intracranial hypertension

    PubMed Central

    James, A. Everette; Harbert, J. C.; Hoffer, P. B.; DeLand, F. H.

    1974-01-01

    The cisternographic images in 10 patients with benign intracranial hypertension were reviewed. Nine were normal. Transfer of labelled tracer from the subarachnoid space was measured in five patients and was found to be abnormal in only two. The relation of these findings to the proposed pathophysiological alterations is discussed. Images

  5. Ringing wormholes

    SciTech Connect

    Konoplya, R.A.; Molina, C.

    2005-06-15

    We investigate the response of traversable wormholes to external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar field. The evolution of perturbations of a wormhole is similar to that of a black hole and represents damped oscillations (ringing) at intermediately late times, which are suppressed by power-law tails (proportional to t{sup -2} for monopole perturbations) at asymptotically late times.

  6. A rabbit model of human familial, nonsyndromic unicoronal suture synostosis. II. Intracranial contents, intracranial volume, and intracranial pressure.

    PubMed

    Mooney, M P; Siegel, M I; Burrows, A M; Smith, T D; Losken, H W; Dechant, J; Cooper, G; Fellows-Mayle, W; Kapucu, M R; Kapucu, L O

    1998-06-01

    This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis, and this second part presents neuropathological findings and age-related changes in intracranial volume (ICV) and intracranial pressure (ICP) in 106 normal rabbits and 56 craniosynostotic rabbits from this colony. Brain morphology and anteroposterior length were described in 44 rabbit fetuses and perinates (27 normal; 17 synostosed). Middle meningeal artery patterns were qualitatively assessed from 2-D PCC MRI VENC scans and endocranial tracings from 15, 126-day-old rabbits (8 normal, 7 rabbits with unicoronal synostosis). Brain metabolism was evaluated by assessing 18F-FDG uptake with high-resolution PET scanning in 7, 25-day-old rabbits (3 normal, 4 with unicoronal or bicoronal synostosis). Intracranial contents and ICV were assessed using 3-D CT scanning of the skulls of 30 rabbits (20 normal,10 with unicoronal synostosis) at 42 and 126 days of age. Serial ICP data were collected from 66 rabbits (49 normal; 17 with unicoronal synostosis) at 25 and 42 days of age. ICP was assessed in the epidural space using a Codman NeuroMonitor microsensor transducer. Results revealed that cerebral cortex morphology was similar between normal and synostosed fetuses around the time of synostosis. Significantly (P<0.05) decreased A-P cerebral hemisphere growth rates and asymmetrical cortical remodeling were noted with increasing age in synostotic rabbits. In addition, rabbits with unicoronal suture synostosis exhibited asymmetrical middle meningeal artery patterns, decreased and asymmetrical brain metabolism, a "beaten-copper" intracranial appearance, significantly (P<0.05) decreased ICV, and significantly (P<0.01) elevated ICP compared with normal control rabbits. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light

  7. [Spontaneous cerebrospinal fluid leak may cause intracranial hypotension].

    PubMed

    Christiansen, Ingelise

    2015-01-01

    Spontaneous intracranial hypotension (SIH) is often misinterpreted as migraine or tension headache. This type of headache is, however, orthostatic and resolves in supine position. CT scan/MRI of the brain has characteristic findings, enhancement of the pachymeninges and bilateral hygroma. An extreme situation of a 70-year-old woman with sagging midbrain is described in this case report. Although this type of headache may be caused by a dural fistula with spinal fluid leak it is not necessary to locate the lesion with myelografi/MR. Timely treatment with an epidural blood patch at any lumbal level could prevent potentially life-threatening complications and the headache resolved within hours/few days. PMID:25557447

  8. Intraoperative fluorescent imaging of intracranial tumors: a review.

    PubMed

    Behbahaninia, Milad; Martirosyan, Nikolay L; Georges, Joseph; Udovich, Joshua A; Kalani, M Yashar S; Feuerstein, Burt G; Nakaji, Peter; Spetzler, Robert F; Preul, Mark C

    2013-05-01

    A review of fluorescent imaging for intracranial neoplasms is presented. Complete resection of brain cancer is seldom possible because of the goal to preserve brain tissue and the inability to visualize individual infiltrative tumor cells. Verification of histology and identification of tumor invasion in macroscopically normal-appearing brain tissue determine prognosis after resection of malignant gliomas. Therefore, imaging modalities aim to facilitate intraoperative decision-making. Intraoperative fluorescent imaging techniques have the potential to enable precise histopathologic diagnosis and to detect tumor remnants in the operative field. Macroscopic fluorescence imaging is effective for gross tumor detection. Microscopic imaging techniques enhance the sensitivity of the macroscopic observations and provide real-time histological information. Further development of clinical grade fluorescent agents specifically targeting tumor cells could improve the diagnostic and prognostic yield of intraoperative imaging. PMID:23523009

  9. CBL Linker Region and RING Finger Mutations Lead to Enhanced Granulocyte-Macrophage Colony-stimulating Factor (GM-CSF) Signaling via Elevated Levels of JAK2 and LYN*

    PubMed Central

    Javadi, Mojib; Richmond, Terri D.; Huang, Kai; Barber, Dwayne L.

    2013-01-01

    Juvenile myelomonocytic leukemia (JMML) is characterized by hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). SHP2, NF-1, KRAS, and NRAS are mutated in JMML patients, leading to aberrant regulation of RAS signaling. A subset of JMML patients harbor CBL mutations associated with 11q acquired uniparental disomy. Many of these mutations are in the linker region and the RING finger of CBL, leading to a loss of E3 ligase activity. We investigated the mechanism by which CBL-Y371H, a linker region mutant, and CBL-C384R, a RING finger mutant, lead to enhanced GM-CSF signaling. Expression of CBL mutants in the TF-1 cell line resulted in enhanced survival in the absence of GM-CSF. Cells expressing CBL mutations displayed increased phosphorylation of GM-CSF receptor βc subunit in response to stimulation, although expression of total GM-CSFR βc was lower. This suggested enhanced kinase activity downstream of GM-CSFR. JAK2 and LYN kinase expression is elevated in CBL-Y371H and CBL-C384R mutant cells, resulting in enhanced phosphorylation of CBL and S6 in response to GM-CSF stimulation. Incubation with the JAK2 inhibitor, TG101348, abolished the increased phosphorylation of GM-CSFR βc in cells expressing CBL mutants, whereas treatment with the SRC kinase inhibitor dasatinib resulted in equalization of GM-CSFR βc phosphorylation signal between wild type CBL and CBL mutant samples. Dasatinib treatment inhibited the elevated phosphorylation of CBL-Y371H and CBL-C384R mutants. Our study indicates that CBL linker and RING finger mutants lead to enhanced GM-CSF signaling due to elevated kinase expression, which can be blocked using small molecule inhibitors targeting specific downstream pathways. PMID:23696637

  10. Idiopathic intracranial hypertension presenting as postpartum headache.

    PubMed

    Mathew, Mariam; Salahuddin, Ayesha; Mathew, Namitha R; Nandhagopal, Ramachandiran

    2016-01-01

    Postpartum headache is described as headache and neck or shoulder pain during the first 6 weeks after delivery. Common causes of headache in the puerperium are migraine headache and tension headache; other causes include pre-eclampsia/eclampsia, post-dural puncture headache, cortical vein thrombosis, subarachnoid hemorrhage, posterior reversible leukoencephalopathy syndrome, brain tumor, cerebral ischemia, meningitis, and so forth. Idiopathic intracranial hypertension (IIH) is a rare cause of postpartum headache. It is usually associated with papilledema, headache, and elevated intracranial pressure without any focal neurologic abnormality in an otherwise healthy person. It is more commonly seen in obese women of reproductive age group, but rare during pregnancy and postpartum. We present a case of IIH who presented to us 18 days after cesarean section with severe headache and was successfully managed. PMID:26818168

  11. Method for noninvasive intracranial pressure measurement

    SciTech Connect

    Sinha, Dipen N.

    2000-01-01

    An ultrasonic-based method for continuous, noninvasive intracranial pressure (ICP) measurement and monitoring is described. The stress level in the skull bone is affected by pressure. This also changes the interfacial conditions between the dura matter and the skull bone. Standing waves may be set up in the skull bone and the layers in contact with the bone. At specific frequencies, there are resonance peaks in the response of the skull which can be readily detected by sweeping the excitation frequency on an excitation transducer in contact with a subject's head, while monitoring the standing wave characteristics from the signal received on a second, receiving transducer similarly in contact with the subject's head. At a chosen frequency, the phase difference between the excitation signal and the received signal can be determined. This difference can be related to the intracranial pressure and changes therein.

  12. Intracranial Artery Calcification and Its Clinical Significance

    PubMed Central

    Wu, Xiao Hong; Wang, Li Juan; Wong, Ka Sing

    2016-01-01

    Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke—through direct arterial stenosis or plaque stability—remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms. PMID:27165425

  13. Giant intracranial aneurysms: rapid sequential computed tomography

    SciTech Connect

    Pinto, R.S.; Cohen, W.A.; Kricheff, I.I.; Redington, R.W.; Berninger, W.H.

    1982-11-01

    Giant intracranial aneurysms often present as mass lesions rather than with subarachnoid hemorrhage. Routine computed tomographic (CT) scans with contrast material will generally detect them, but erroneous diagnosis of basal meningioma is possible. Rapid sequential scanning (dynamic CT) after bolus injection of 40 ml of Renografin-76 can conclusively demonstrate an intracranial aneurysm, differentiating it from other lesions by transit-time analysis of the passage of contrast medium. In five patients, the dynamics of contrast bolus transit in aneurysms were consistently different from the dynamics in pituitary tumors, craniopharyngiomas, and meningiomas, thereby allowing a specific diagnosis. Dynamic CT was also useful after treatment of the aneurysms by carotid artery ligation and may be used as an alternative to angiographic evaluation in determining luminal patency or thrombosis.

  14. Ruptured, Intracranial Dermoid Cyst - A Visual Diagnosis?

    PubMed Central

    Scheer, Fabian; Andresen, Reimer

    2016-01-01

    Dermoid cysts are a very rare entity of intracranial tumours. The traumatic or non-traumatic rupture of the cyst wall is a serious complication that can be treated surgically or conservatively depending on the clinical symptoms. However, more common entities have to be considered as a differential diagnosis. We report on a female patient who was admitted with complaints of significant, prolonged headache and diffuse pain. Analysis of her blood and cerebrospinal fluid indicated no clear pathology. A CT examination of the head revealed a ruptured dermoid cyst adjacent to the left sphenoidal bone. An additional MRI was conducted to confirm the CT findings and rule out an intracranial ischemia or vasospasms. A conservative therapy was scheduled and the patient recovered well. Using current imaging techniques, especially magnetic resonance imaging, it is possible to identify a ruptured dermoid cyst by its pathognomonic signal behavior and rule out potentially life threatening complications. PMID:27190918

  15. [Therapeutic activity of gemcitabine in intracranial tumors].

    PubMed

    Stukov, A N; Filatova, L V; Latipova, D Kh; Bespalov, V G; Belyaeva, O A; Kireeva, G S; Vasilieva, I N; Alexandrov, V A; Maidin, M A; Semenov, A L; Vershinina, S F; Markochev, A B; Abduloeva, N Kh; Chubenko, V A; Semiglazova, T Yu

    2015-01-01

    Gemcitabine is known to exert a therapeutic effect on brain tumors despite the limited permeability of the blood-brain barrier (BBB). In our experimental research single intraperitoneal (i.p.) injection of gemcitabine 25 mg/kg provided increase in median survival of mice with intracranially transplanted Ehrlich carcinoma by 41-89% (p < 0.001). In this experimental model i.p. administration of gemcitabine (permeability of the BBB of less than 10%), carmustine (good permeability of the BBB), cyclophosphamide (poor permeability of the BBB) and cisplatin (doesn't penetrate through the BBB) increased median survival of mice by 88% (p < 0.001), 59% (p = 0.001), 35% (p = 0.005) and 18% (p = 0.302) respectively. Considering strong correlation between antitumor activity of the drugs (carmustine, cyclophosphamide and cisplatin) and their permeability of the BBB, efficacy of gemcitabine in intracranial tumors could be due to its wide range of therapeutic doses. PMID:26087611

  16. Isolated Intracranial Rosai-Dorfman Disease

    PubMed Central

    Taufiq, Md.; Khair, Abul; Begum, Ferdousy; Akhter, Shabnam; Shamim Farooq, Md.; Kamal, Mohammed

    2016-01-01

    Background. Rosai-Dorfman disease (RDD) is a benign histiocytic proliferative disorder of unknown etiology. This rare condition commonly causes massive cervical lymphadenopathy. Intracranial RDD without any nodal involvement is extremely rare. Case Report. A young Bangladeshi male complained of bilateral complete blindness with left sided deafness for about three years. There was no lymphadenopathy. MRI and CT scan of brain suggested an inflammatory/neoplastic (?meningioma) lesion located at left parasellar region which extended frontally to encircle both optic nerves and also to left prepontine area. Histopathologically the lesion was diagnosed as RDD. The patient was treated with steroid and significant clinical improvement observed. Conclusion. The prognosis of intracranial RDD is not poor. It can be treated with surgery with or without corticosteroids, chemotherapy, and so forth. But as the condition is extremely rare and often misdiagnosed, the clinician, radiologist, and histopathologist should have a suspicion in their mind about the possibility of RDD. PMID:26949555

  17. Intracranial Carotid Calcification on Cranial Computed Tomography

    PubMed Central

    Subedi, Deepak; Zishan, Umme Sara; Chappell, Francesca; Gregoriades, Maria-Lena; Sudlow, Cathie; Sellar, Robin

    2015-01-01

    Background and Purpose— Intracranial internal carotid artery calcification is associated with cerebrovascular risk factors and stroke, but few quantification methods are available. We tested the reliability of visual scoring, semiautomated Agatston score, and calcium volume measurement in patients with recent stroke. Methods— We used scans from a prospective hospital stroke registry and included patients with anterior circulation ischemic stroke or transient ischemic stroke whose noncontrast cranial computed tomographic scans were available electronically. Two raters measured semiautomatic quantitative Agatston score, and calcium volume, and performed qualitative visual scoring using the original 4-point Woodcock score and a modified Woodcock score, where each image on which the internal carotid arteries appeared was scored and the slice scores summed. Results— Intra- and interobserver coefficient of variations were 8.8% and 16.5% for Agatston, 8.8% and 15.5% for calcium volume, and 5.7% and 5.4% for the modified Woodcock visual score, respectively. The modified Woodcock visual score correlated strongly with both Agatston and calcium volume quantitative measures (both R2=0.84; P<0.0001); calcium volume increased by 0.47-mm/point increase in modified Woodcock visual score. Intracranial internal carotid artery calcification increased with age by all measures (eg, visual score, Spearman ρ=0.4; P=0.005). Conclusions— Visual scores correlate highly with quantitative intracranial internal carotid artery calcification measures, with excellent observer agreements. Visual intracranial internal carotid artery scores could be a rapid and practical method for epidemiological studies. PMID:26251250

  18. Multiple Intracranial Aneurysms in HIV Infection.

    PubMed

    Dhawan, Sumeet R; Gupta, Anju; Gupta, Vivek; Singhi, Pratibha D

    2016-08-01

    Neurological findings in HIV are common and include cognitive impairment, microcephaly, nonspecific white matter lesions and seizures. Cerebral vasculopathy and stroke are uncommon and may be due to primary HIV vasculopathy or opportunistic infections such as tuberculosis and cryptococcal meningitis. The authors describe a 7-y-old boy who presented with severe headache and was detected to have aneurysmal bleed due to intracranial aneurysm. PMID:27072660

  19. Filum ependymoma mimicking spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Akopov, Sergey E

    2005-05-01

    A 34-year-old man with a 2-week history of orthostatic headaches and a "dry tap" at lumbar puncture was found to have a lumbar intradural mass on magnetic resonance imaging (MRI) examination. A myxopapillary ependymoma was resected and the patient's headache completely resolved. The combination of spontaneous orthostatic headaches and a "dry tap" at the time of lumbar puncture does not always indicate the presence of a spontaneous cerebrospinal fluid (CSF) leak and intracranial hypotension. PMID:15953283

  20. A novel guide catheter enabling intracranial placement.

    PubMed

    Hurley, Michael C; Sherma, Arun K; Surdell, Daniel; Shaibani, Ali; Bendok, Bernard R

    2009-11-15

    We describe use of a novel guide, catheter with a soft and pliable, 6-cm or 12-cm distal segment that enables distal, including intracranial, placement--the Neuron guide catheter (Penumbra, San Leandro, CA)--in the treatment of 11 cases with a range of neuroendovascular lesions. We were able to advance the Neuron guide catheter to the intended level in each case and suffered no complications related to catheter spasm, dissection, thrombosis or thromboembolism. PMID:19670314

  1. Intracranial capillary hemangioma mimicking a dissociative disorder

    PubMed Central

    John, Santosh G.; Pillai, Unnikrishnan; Lacasse, Alexander

    2012-01-01

    Capillary hemangiomas, hamartomatous proliferation of vascular endothelial cells, are rare in the central nervous system (CNS). Intracranial capillary hemangiomas presenting with reversible behavioral abnormalities and focal neurological deficits have rarely been reported. We report a case of CNS capillary hemangioma presenting with transient focal neurological deficits and behavioral abnormalities mimicking Ganser's syndrome. Patient underwent total excision of the vascular malformation, resulting in complete resolution of his symptoms. PMID:24765434

  2. Intracranial hemorrhage in cancer patients treated with anticoagulation.

    PubMed

    Weinstock, Matthew J; Uhlmann, Erik J; Zwicker, Jeffrey I

    2016-04-01

    Both venous thromboembolism and intracranial metastases are common complications in the setting of primary brain tumors and metastatic malignancies. Anticoagulation is indicated in the presence of cancer-associated thrombosis in order to limit the risk of pulmonary embolism; however, there is reluctance to initiate anticoagulation in the setting of intracranial metastatic disease due to potential for intracranial hemorrhage. Recent evidence suggests that therapeutic anticoagulation can be safely administered in the setting of metastatic brain tumors. This review examines the current understanding of the pathophysiology of intracranial hemorrhage in malignancy, describes the incidence of intracranial hemorrhage in the setting of brain tumors with therapeutic anticoagulation, and outlines management strategies relevant to the treatment of intracranial hemorrhage in the setting of anticoagulation. PMID:27067980

  3. Spaceflight-Induced Intracranial Hypertension: An Overview

    NASA Technical Reports Server (NTRS)

    Traver, William J.

    2011-01-01

    This slide presentation is an overview of the some of the known results of spaceflight induced intracranial hypertension. Historical information from Gemini 5, Apollo, and the space shuttle programs indicated that some vision impairment was reported and a comparison between these historical missions and present missions is included. Optic Disc Edema, Globe Flattening, Choroidal Folds, Hyperopic Shifts and Raised Intracranial Pressure has occurred in Astronauts During and After Long Duration Space Flight. Views illustrate the occurrence of Optic Disc Edema, Globe Flattening, and Choroidal Folds. There are views of the Arachnoid Granulations and Venous return, and the question of spinal or venous compliance issues is discussed. The question of increased blood flow and its relation to increased Cerebrospinal fluid (CSF) is raised. Most observed on-orbit papilledema does not progress, and this might be a function of plateau homeostasis for the higher level of intracranial pressure. There are seven cases of astronauts experiencing in flight and post flight symptoms, which are summarized and follow-up is reviewed along with a comparison of the treatment options. The question is "is there other involvement besides vision," and other Clinical implications are raised,

  4. Angioplasty and Stenting for Intracranial Stenosis

    PubMed Central

    IZUMI, Takashi; IMAMURA, Hirotoshi; SAKAI, Nobuyuki; MIYACHI, Shigeru

    2014-01-01

    Of the patients enrolled in the Japanese Registry of Neuroendovascular Therapy (JR-NET), a surveillance study in Japanese, 1133 patients who underwent intracranial percutaneous transluminal angioplasty (PTA)/stenting for intracranial stenosis during the period from 2005 to 2009 were investigated. A technical success was achieved in 98.3% of the patients, and 70.5% and 7.5% had a residual stenosis of < 30% and ≥ 50%, respectively. The incidence of ischemic complications and hemorrhagic complications was as low as 7.7% and 2.5%, respectively, but tended to increase in patients who underwent stenting. While a significant correlation with ischemic complications was observed in previously untreated patients and patients who underwent stenting followed by post-dilatation, a significant correlation with hemorrhagic complications was observed in patients who received emergency treatment and those treated between 24 hours and 14 days of the onset. Flexible intracranial stents are expected to contribute to improvement in the treatment outcome. PMID:24390191

  5. Detection of increased intracranial pressure by ultrasound.

    PubMed

    Hightower, Stephanie; Chin, Eric J; Heiner, Jason D

    2012-01-01

    Increases in intracranial pressure (ICP) may damage the brain by compression of its structures or restriction of its blood flow, and medical providers my encounter elevated ICP in conventional and non-conventional medical settings. Early identification of elevated ICP is critical to ensuring timely and appropriate management. However, few diagnostic methods are available for detecting increased ICP in an acutely ill patient, which can be performed quickly and noninvasively at the bedside. The optic nerve sheath is a continuation of the dura mater of the central nervous system and can be viewed by ocular ultrasound. Pressure changes within the intracranial cavity affect the diameter of the optic nerve sheath. Data acquired from multiple clinical settings suggest that millimetric increases in the optic nerve sheath diameter detected via ocular ultrasound correlate with increasing levels of ICP. In this review, we discuss the use of ocular ultrasound to evaluate for the presence of elevated ICP via assessment of optic nerve sheath diameter, and describe critical aspects of this valuable diagnostic procedure. Ultrasound is increasingly becoming a medical fixture in the modern battlefield where other diagnostic modalities can be unavailable or impractical to employ. As Special Forces and other austere medical providers become increasingly familiar with ultrasound, ocular ultrasound for the assessment of increased intracranial pressure may help optimize their ability to provide the most effective medical management for their patients. PMID:23032316

  6. Intracranial bacterial infections of oral origin.

    PubMed

    Moazzam, Alan A; Rajagopal, Sowmya M; Sedghizadeh, Parish P; Zada, Gabriel; Habibian, Mina

    2015-05-01

    Brain abscesses are rare but potentially deadly complications of odontogenic infections. This phenomenon has been described mainly in the form of case reports, as large-scale studies are difficult to perform. We compiled a total of 60 previously published cases of such a complication to investigate the predisposing factors, microbiology, and clinical outcomes of intracranial abscesses of odontogenic origin. A systematic review of the literature using the PubMed database was performed. Men accounted for 82.1% of cases, and the mean age was 42.1 years. Caries with periapical involvement and periodontitis were the two most common intra-oral sources, and wisdom tooth extraction was the most common preceding dental procedure. In 56.4% of cases, there were obvious signs of dental disease prior to development of intracranial infection. Commonly implicated microorganisms included Streptococcus viridans (especially the anginosus group), Actinomyces, Peptostreptococcus, Prevotella, Fusobacterium, Aggregatibacter actinomycetemcomitans and Eikenella corrodens. There was an 8.3% mortality rate. Intracranial abscesses can form anywhere within the brain, and appear unrelated to the side of dental involvement. This suggests that hematogenous spread is the most likely route of dissemination. PMID:25800939

  7. Gamma Knife radiosurgery for intracranial hemangioblastoma.

    PubMed

    Silva, Danilo; Grabowski, Mathew M; Juthani, Rupa; Sharma, Mayur; Angelov, Lilyana; Vogelbaum, Michael A; Chao, Samuel; Suh, John; Mohammadi, Alireza; Barnett, Gene H

    2016-09-01

    Gamma knife radiosurgery (GKRS) has become a treatment option for intracranial hemangioblastomas, especially in patients with poor clinical status and also high-risk surgical candidates. The objective of this study was to analyze clinical outcome and tumor control rates. Retrospective chart review revealed 12 patients with a total of 20 intracranial hemangioblastomas treated with GKRS from May 1998 until December 2014. Kaplan-Meier plots were used to calculate the actuarial local tumor control rates and rate of recurrence following GKRS. Univariate analysis, including log rank test and Wilcoxon test were used on the Kaplan-Meier plots to evaluate the predictors of tumor progression. Two-tailed p value of <0.05 was considered as significant. Median follow-up was 64months (2-184). Median tumor volume pre-GKRS was 946mm(3) (79-15970), while median tumor volume post-GKRS was 356mm(3) (30-5404). Complications were seen in two patients. Tumor control rates were 100% at 1year, 90% at 3years, and 85% at 5years, using the Kaplan-Meier method. There were no statistically significant univariate predictors of progression identified, although there was a trend towards successful tumor control in solid tumors (p=0.07). GKRS is an effective and safe option for treating intracranial hemangioblastoma with favorable tumor control rates. PMID:27422585

  8. Imaging and interventions in idiopathic intracranial hypertension: A pictorial essay.

    PubMed

    Sivasankar, Rajeev; Pant, Rochan; Indrajit, Inna K; Negi, Raj S; Sahu, Samresh; Hashim, P I; D'Souza, John

    2015-01-01

    Intracranial hypertension is a syndrome of elevated intracranial pressure that can be primary or secondary. The primary form, now termed idiopathic intracranial hypertension (IIH), was in the past a disease of exclusion and imaging played a limited role of excluding organic causes of raised intracranial pressure. However imaging markers have been described with patients with IIH at the orbit, sella and cerebral venous system. We wish to reiterate the characteristic imaging features of this poorly understood disease and also emphasise that stenting of the transverse sinus in select cases of IIH is an efficacious option. PMID:26752823

  9. Imaging and interventions in idiopathic intracranial hypertension: A pictorial essay

    PubMed Central

    Sivasankar, Rajeev; Pant, Rochan; Indrajit, Inna K; Negi, Raj S; Sahu, Samresh; Hashim, PI; D’Souza, John

    2015-01-01

    Intracranial hypertension is a syndrome of elevated intracranial pressure that can be primary or secondary. The primary form, now termed idiopathic intracranial hypertension (IIH), was in the past a disease of exclusion and imaging played a limited role of excluding organic causes of raised intracranial pressure. However imaging markers have been described with patients with IIH at the orbit, sella and cerebral venous system. We wish to reiterate the characteristic imaging features of this poorly understood disease and also emphasise that stenting of the transverse sinus in select cases of IIH is an efficacious option. PMID:26752823

  10. [Intracranial volume reserve assessment based on ICP pulse wave analysis].

    PubMed

    Berdyga, J; Czernicki, Z; Jurkiewicz, J

    1994-01-01

    ICP waves were analysed in the situation of expanding intracranial mass. The aim of the study was to determine how big the intracranial added volume has to be in order to produce significant changes of harmonic disturbances index (HFC) of ICP pulse waves. The diagnostic value of HFC and other parameters was compared. The following other parameters were studied: intracranial pressure (ICP), CSF outflow resistance (R), volume pressure response (VPR) and visual evoked potentials (VEP). It was found that ICP wave analysis very clearly reflects the intracranial volume-pressure relation changes. PMID:8028705

  11. A segmentation algorithm of intracranial hemorrhage CT image

    NASA Astrophysics Data System (ADS)

    Wang, Haibo; Chen, Zhiguo; Wang, Jianzhi

    2011-10-01

    To develop a computer aided detection (CAD) system that improves diagnostic accuracy of intracranial hemorrhage on cerebral CT. A method for CT image segmentation of brain is proposed, with which, several regions that are suspicious of hemorrhage can be segmented rapidly and effectively. Extracting intracranial area algorithm is introduced firstly to extract intracranial area. Secondly, FCM is employed twice, we named it with TFCM. FCM is first employed to identify areas of intracranial hemorrhage. Finally, FCM is employed to segment the lesions. Experimental results on real medical images demonstrate the efficiency and effectiveness.

  12. Time-Resolved 3D Contrast-Enhanced MRA on 3.0T: a Non-Invasive Follow-Up Technique after Stent-Assisted Coil Embolization of the Intracranial Aneurysm

    PubMed Central

    Choi, Jin Woo; Moon, Won-Jin; Kim, Na Ra; Moon, Sung Gyu; Kang, Chung Hwan; Chun, Young Il; Kang, Hyun-Seung

    2011-01-01

    Objective To evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA. Materials and Methods TOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method. Results The quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively. Conclusion 4D MRA provides a higher quality view of the stented parent arteries when compared with TOF. PMID:22043147

  13. Asymmetric dipolar ring

    DOEpatents

    Prosandeev, Sergey A.; Ponomareva, Inna V.; Kornev, Igor A.; Bellaiche, Laurent M.

    2010-11-16

    A device having a dipolar ring surrounding an interior region that is disposed asymmetrically on the ring. The dipolar ring generates a toroidal moment switchable between at least two stable states by a homogeneous field applied to the dipolar ring in the plane of the ring. The ring may be made of ferroelectric or magnetic material. In the former case, the homogeneous field is an electric field and in the latter case, the homogeneous field is a magnetic field.

  14. Spontaneous intracranial hypotension with bilateral subdural hemorrhage: Is conservative management adequate?

    PubMed Central

    Ahmad, Mohammed Tauqeer; Hameed, Shahul; Lin, Kei Pin; Prakash, Kumar M

    2013-01-01

    The aim of this study is to report a case of spontaneous intracranial hypotension complicated by bilateral subdural hemorrhage that resolved with conservative management. A young male presented with severe orthostatic headache associated with dizziness, neck pain and diplopia. Brain imaging revealed characteristic pachymeningeal enhancement and bilateral subdural hemorrhage. Radionuclide cisternography confirmed the Cerebrospinal fluid leak at the cervical 5 and cervical 6 vertebral level. He had clinical and radiological resolution with bed rest, hydration and analgesics and has remained symptom free since then. Spontaneous intracranial hypotension may be complicated by bilateral subdural hemorrhage. A conservative treatment approach is a viable option, as it may help improve the clinical and radiological outcome, especially when interventional facilities are not available. PMID:23661973

  15. B-Ring-Aryl Substituted Luotonin A Analogues with a New Binding Mode to the Topoisomerase 1-DNA Complex Show Enhanced Cytotoxic Activity

    PubMed Central

    González-Ruiz, Víctor; Pascua, Irene; Fernández-Marcelo, Tamara; Ribelles, Pascual; Bianchini, Giulia; Sridharan, Vellaisamy; Iniesta, Pilar; Ramos, M. Teresa; Olives, Ana I.; Martín, M. Antonia; Menéndez, J. Carlos

    2014-01-01

    Topoisomerase 1 inhibition is an important strategy in targeted cancer chemotherapy. The drugs currently in use acting on this enzyme belong to the family of the camptothecins, and suffer severe limitations because of their low stability, which is associated with the hydrolysis of the δ-lactone moiety in their E ring. Luotonin A is a natural camptothecin analogue that lacks this functional group and therefore shows a much-improved stability, but at the cost of a lower activity. Therefore, the development of luotonin A analogues with an increased potency is important for progress in this area. In the present paper, a small library of luotonin A analogues modified at their A and B rings was generated by cerium(IV) ammonium nitrate-catalyzed Friedländer reactions. All analogues showed an activity similar or higher than the natural luotonin A in terms of topoisomerase 1 inhibition and some compounds had an activity comparable to that of camptothecin. Furthermore, most compounds showed a better activity than luotonin A in cell cytotoxicity assays. In order to rationalize these results, the first docking studies of luotonin-topoisomerase 1-DNA ternary complexes were undertaken. Most compounds bound in a manner similar to luotonin A and to standard topoisomerase poisons such as topotecan but, interestingly, the two most promising analogues, bearing a 3,5-dimethylphenyl substituent at ring B, docked in a different orientation. This binding mode allows the hydrophobic moiety to be shielded from the aqueous environment by being buried between the deoxyribose belonging to the G(+1) guanine and Arg364 in the scissile strand and the surface of the protein and a hydrogen bond between the D-ring carbonyl and the basic amino acid. The discovery of this new binding mode and its associated higher inhibitory potency is a significant advance in the design of new topoisomerase 1 inhibitors. PMID:24830682

  16. Platelet interaction within giant intracranial aneurysms

    SciTech Connect

    Sutherland, G.R.; King, M.E.; Peerless, S.J.; Vezina, W.C.; Brown, G.W.; Chamberlain, M.J.

    1982-01-01

    Turbulence within intracranial aneurysms may result in tearing of the aneurysmal wall, exposing the subendothelial matrix to circulating platelets. In this study, platelet interaction in giant intracranial aneurysms was evaluated by a dual-isotope technique employing In-labeled platelets and Tc-labeled red blood cells. The use of two isotopes allows the subtraction of the blood pool and the calculation of the ratio indium deposited:indium blood pool (In(D)/In(BP)). A ratio greater than zero indicates platelet deposition within aneurysm. Thirteen patients were evaluated in this way, with platelet deposition demonstrated in six. In these six patients, the ratio In(D)/In(BP) was found to be significantly elevated, with a mean value of 0.96 +/- 0.65. Three of these six patients has symptoms of recurrent transient neurological deficits; one of these three suffered a complete stroke following documentation of platelet deposition. In this case, the aneurysm was obtained at surgery and was found to contain intraluminal platelet aggregation when viewed by scanning electron microscopy. In the remaining seven patients, the ratio IN(D)/In(BP) was found not to be significantly elevated (mean -0.03 and/- 0.06), indicating the absence of active platelet deposition. Two of these patients had prior symptoms of cerebral ischemia; one of these was found to have an ulcer in the ipsilateral internal carotid artery which was probably responsible for thromboembolic events to the hemisphere. The authors conclude that platelet aggregation occurs more frequently than previously recognized in giant intracranial aneurysms, and their data substantiate the hypothesis that platelet metabolic products or thrombi originating from a large aneurysm may embolize to distal cerebral vessels.

  17. A Practical Approach to the Diagnosis of Spontaneous Intracranial Hypotension.

    PubMed

    Steenerson, Kristen; Halker, Rashmi

    2015-08-01

    Spontaneous intracranial hypotension can be difficult to diagnose as there are a number of tests available and knowing how to appropriately choose amongst them is not always easy. In this article, we will review the available diagnostic options and provide a practical approach to the workup of a patient with suspected intracranial hypotension. PMID:26077206

  18. Intracranial subdural hygroma after Le Fort I osteotomy.

    PubMed

    Thompson, William L; Lee, Michael; MacIntosh, Robert Bruce

    2015-04-01

    Various intra- and postoperative complications have been well-documented after Le Fort I osteotomies; however, an intracranial subdural hygroma has not yet been reported in oral and maxillofacial studies. We report a unique case of an intracranial subdural hygroma requiring neurosurgical intervention after Le Fort I advancement. PMID:25631863

  19. Intracranial hypertension secondary to a skull lesion without mass effect.

    PubMed

    Serlin, Yonatan; Benifla, Mony; Kesler, Anat; Cohen, Avi; Shelef, Ilan

    2016-09-01

    We report and discuss five patients with intracranial hypertension due to a skull lesion reducing cerebral sinus patency with a compressive, non-thrombotic mechanism. We illustrate the importance of a high level of suspicion for this condition in patients presenting with headache, papilledema and increased intracranial pressure in the absence of focal signs or radiological evidence of mass effect. PMID:27283387

  20. Clarithromycin Culprit of Benign Intracranial Hypertension

    PubMed Central

    Khan, Habib Rehman; Mason, Colin; Mulcahy, Riona

    2015-01-01

    Benign intracranial hypertension is characterized with increase in CSF opening pressure with no specific etiology. It is predominantly found in women of child bearing age and particularly in individuals with obesity. Visual disturbances or loss and associated headaches are common and can lead to blindness if left untreated. Diagnosis can be achieved once other causes of visual loss, headaches and high opening pressures are excluded. Management consists of serial optic disc assessments although no specific treatment is available despite recent trials using carbonic anhydrase inhibitors. Diet modification and weight management can help in therapy. PMID:26713029

  1. [Intracranial tumors and epileptic seizures: treatment principles].

    PubMed

    Rossetti, Andrea O; Vulliémoz, Serge

    2016-04-27

    Epileptic seizures represent a relatively frequent issue in patients with intracranial neoplasms, and very frequently imply the start of an antiepileptic treatment as secondary prophylaxis. Even if the current level of evidence is relatively low, compounds with a limited risk of pharmacokinetic interactions are clearly preferred. Levetiracetam is probably the most prescribed agent in this setting, while pregabalin, valproate, lacosamide and lamotrigine are valuable alternatives. The treatment choice has to consider the different profiles of side effects and should be tailored to each patient. In this setting, a multidisciplinary approach including general practicioner, oncologist and neurologist is strongly advocated. PMID:27281943

  2. Intracranial Extramedullary Hematopoiesis in Beta-Thalassemia

    PubMed Central

    Karki, Bivek; Tamrakar, Karuna; Wu, Yuan-Kui

    2012-01-01

    Extramedullary hematopoiesis (EMH) represents tumor-like proliferation of hemopoietic tissue which complicates chronic hemoglobinopathy. Intracranial EMH is an extremely rare occurrence. Magnetic resonance imaging (MRI) offers a precise diagnosis. It is essential to distinguish EMH from other extradural central nervous system tumors, because treatment and prognosis are totally different. Herein, we report the imaging findings of beta-thalassemia in a 13-year-old boy complaining of weakness of left side of the body and gait disturbance; CT and MRI revealed an extradural mass in the right temporoparietal region. PMID:22438693

  3. Ultrasonic Apparatus and Technique to Measure Changes in Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

  4. Whole-body mathematical model for simulating intracranial pressure dynamics

    NASA Technical Reports Server (NTRS)

    Lakin, William D. (Inventor); Penar, Paul L. (Inventor); Stevens, Scott A. (Inventor); Tranmer, Bruce I. (Inventor)

    2007-01-01

    A whole-body mathematical model (10) for simulating intracranial pressure dynamics. In one embodiment, model (10) includes 17 interacting compartments, of which nine lie entirely outside of intracranial vault (14). Compartments (F) and (T) are defined to distinguish ventricular from extraventricular CSF. The vasculature of the intracranial system within cranial vault (14) is also subdivided into five compartments (A, C, P, V, and S, respectively) representing the intracranial arteries, capillaries, choroid plexus, veins, and venous sinus. The body's extracranial systemic vasculature is divided into six compartments (I, J, O, Z, D, and X, respectively) representing the arteries, capillaries, and veins of the central body and the lower body. Compartments (G) and (B) include tissue and the associated interstitial fluid in the intracranial and lower regions. Compartment (Y) is a composite involving the tissues, organs, and pulmonary circulation of the central body and compartment (M) represents the external environment.

  5. Ultrasonic Apparatus and Technique to Measure Changes in Intracranial Pressure

    NASA Astrophysics Data System (ADS)

    Yost, William T.; Cantrell, John H.

    2002-11-01

    Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

  6. Spontaneous intracranial hypo and hypertensions: an imaging review.

    PubMed

    Vaghela, Viratsinh; Hingwala, Divyata Rajendra; Kapilamoorthy, Tirur Raman; Kesavadas, Chandrasekharan; Thomas, Bejoy

    2011-01-01

    Cerebrospinal fluid (CSF) pressure changes can manifest as either intracranial hypertension or hypotension. The idiopathic forms are largely under or misdiagnosed. Spontaneous intracranial hypotension occurs due to reduced CSF pressure usually as a result of a spontaneous dural tear. Idiopathic intracranial hypertension (IIH) is a syndrome of elevated intracranial tension without hydrocephalus or mass lesions and with normal CSF composition. Neuroimaging plays an important role in excluding secondary causes of raised intracranial tension. As the clinical presentation is varied, imaging may also help the clinician in arriving at the diagnosis of IIH with the help of a few specific signs. In this review, we attempt to compile the salient magnetic resonance imaging findings in these two conditions. Careful observation of these findings may help in early accurate diagnosis and to provide appropriate early treatment. PMID:21891924

  7. Saturn's Spectacular Ring System

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Saturn's beautiful rings have fascinated astronomers since they were first observed by Galileo in 1610. The main rings consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The ring disk is exceptionally thin - the typical local thickness of the bright rings is tens of meters, whereas the diameter of the main rings is 250,000 km! The main rings exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main rings lie tenuous dust rings, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of ring-moon interactions, recent advances in our understanding of various aspects of the rings obtained from observations taken during 1995 when the rings appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.

  8. The contemporary management of intracranial atherosclerotic disease.

    PubMed

    Leng, Xinyi; Wong, Ka Sing; Leung, Thomas W

    2016-06-01

    Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies. PMID:27082149

  9. Neuroblastoma with intracranial involvement: an ENSG Study.

    PubMed

    Shaw, P J; Eden, T

    1992-01-01

    We report the experience of the European Neuroblastoma Study Group (ENSG) with central nervous system (CNS) involvement of neuroblastoma. Among this series of intensively treated patients, CNS neuroblastoma was diagnosed by computerised tomography (CT) scanning, rather than by autopsy. Cranial disease occurred in 5% of ENSG patients. Of 11 patients with intracranial disease, 4 had disease in the posterior fossa, a site rarely reported previously. Furthermore, 5 cases had CNS metastases at a time when there was no detectable disease elsewhere, rather than as part of extensive relapse. The pattern of disease we observed, at least for those with parenchymal disease, is in keeping with arterial spread. Although CT scanning is the optimal modality for identifying CNS disease, 2 cases had normal head CT scans prior to the onset of CNS disease. As most patients had symptoms of raised intracranial pressure (RICP) at the time the CNS disease was diagnosed, there does not seem to be any indication for routine CT scanning of the head at diagnosis, but this should be performed as soon as any symptoms or signs appear. With patients living longer with their disease, vigilance must be maintained during follow-up. PMID:1734220

  10. Multiple intracranial abscesses: Heralding asymptomatic venosus ASD.

    PubMed

    Gupta, Praveen K; Marzook, Rehab Ali; Sulaibeekh, Leena

    2013-10-01

    A case of multiple intracranial abscesses in an immune-competent young girl is reported. She had chicken pox. Two weeks later, she presented with multiple intracranial abscesses. No significant cardiac abnormality was detected on transthoracic echocardiogram (TTE). The condition was treated medically. However, one of the abscesses adjacent to the CSF pathways enlarged on treatment and caused obstructive hydrocephalus that required stereotactic aspiration. Gram stain showed gram positive cocci in chain. Pus was sterile on culture. She was treated with broad spectrum IV antibiotics based on Gram staining report for 6 weeks followed by another 8 weeks of oral antibiotics. She made good recovery and had been leading a normal life. The abscess capsules took 30 months to resolve completely on MRI. A repeat TTE done in the follow up showed enlarged right heart chambers with a suggestion of a venosus ASD. A trans-esophageal echocardiogram (TEE) confirmed the presence of sinus venosus ASD from the SVC side with mainly left to right shunt. There was also partial anomalous drainage of the pulmonary veins. The patient underwent correction of the defect and has been doing well. PMID:24551007

  11. Spontaneous thrombosis in giant intracranial aneurysms.

    PubMed Central

    Whittle, I R; Dorsch, N W; Besser, M

    1982-01-01

    Twelve patients in a series of 22 with giant intracranial aneurysms demonstrated neuroradiological features of partial or total spontaneous intra-aneurysmal thrombosis. The presence of this intra-aneurysmal clot significantly altered the computed tomographic appearance of the giant aneurysm. Massive intra-aneurysmal thrombosis did not protect against subarachnoid haemorrhage and the likelihood of rupture of a clot containing giant aneurysm was not significantly different from that of a non-thrombosed giant aneurysm. Although parent artery occlusion from a thrombosed giant aneurysm, and massive aneurysmal thrombosis leading to the formation of giant serpentine aneurysm were documented, these are rare epiphenomena. The risk of embolisation from a partially thrombosed giant aneurysm, which was documented in one case, would appear to be greater than that from a non-thrombosed giant aneurysm. The findings in this series, and a review of literature, suggest that the presence of intra-aneurysmal clot in giant intracranial aneurysms has little prognostic significance and does not alter the management or outcome after treatment. Images PMID:7175528

  12. [Intracranial arteriovenous malformations in pregnant women].

    PubMed

    Perquin, D A; Kloet, A; Tans, J T; Witte, G N; Dörr, P J

    1999-03-01

    Three women, aged 27, 32 and 30 years, respectively, suffered from headache, nausea and neurological abnormalities and were found to have an intracranial arteriovenous malformation (AVM). One of them after diagnosis had two pregnancies, both ended by caesarean section with good results. Another woman was 32 weeks pregnant when the AVM manifested itself with a haemorrhage; she recovered well and was delivered by caesarean section. After the AVM proved radiologically to have been obliterated, she delivered after her subsequent pregnancy by the vaginal route with vacuum extraction. The third woman was 15 weeks pregnant when major abnormalities developed. There was a large intracerebral haematoma with break-through to the ventricular system; this patient died. Intracranial haemorrhage during pregnancy is rate. It can result in maternal and foetal morbidity and mortality. It appears that pregnancy does not increase the rate of first cerebral haemorrhage from an AVM. The management of AVM rupture during pregnancy should be based primarily on neurosurgical rather than on obstetric considerations. Close collaboration with a team of neurologists, neurosurgeons, obstetricians and anaesthesiologists is mandatory. PMID:10321255

  13. Carcinoembryonic antigen in patients with intracranial tumors.

    PubMed

    Suzuki, Y; Tanaka, R

    1980-09-01

    Carcinoembryonic antigen (CEA) in plasma, cerebrospinal fluid (CSF), and tumor cyst fluid obtained from patients with a variety of intracranial tumors was determined by radioimmunoassay Slightly elevated levels of plasma CEA, ranging from 2.6 to 3.8 ng/ml, were noted in six (4%) of 161 patients with primary brain tumors: in three gliomas, two pineal tumors, and one acoustic neurinoma, respectively. On the other hand, 17 (37%) of 46 patients with metastatic brain tumors showed a definite elevation, and most of them had values higher than 5.0 ng/ml. Of 37 patients with primary brain tumors, only one with a pineal germinoma showed a significant elevation of CEA in CSF, whereas eight (44%) of 18 patients with metastatic brain tumors showed high values of CEA in CSF. All six patients with leptomeningeal carcinomatosis showed elevated CEA in CSF. Levels of CEA in tumor cyst fluid were determined in 17 patients with intracranial tumors, including 12 gliomas, two craniopharyngiomas, two metastatic tumors, and one meningioma; elevation of CEA in tumor fluid was noted in two craniopharyngiomas and one metastatic tumor. Sequential determination of CEA of plasma or CSF revealed that the CEA levels were well correlated with the activity of brain tumors. Consequently, the determination of CEA in plasma or CSF is valuable for the differential diagnosis between primary and metastatic brain tumors and for the management of CEA-producing tumors. PMID:7420150

  14. The spectrum of intracranial aneurysms in pediatrics.

    PubMed

    Kanaan, I; Lasjaunias, P; Coates, R

    1995-03-01

    Intracranial aneurysms are rare in children, accounting for merely 0.5-4.6% of all aneurysms. Several characteristics distinguish them from aneurysms in adults: male predominance; higher incidence of unusual location, such as peripheral or posterior circulation; and a greater number of large and giant aneurysms. These unique features can be attributed to the higher incidence of traumatic, infectious, developmental, and congenital lesions. Subarachnoid hemorrhage is not the exclusive mode of presentation; neuro-compressive signs and symptoms are also frequently seen. The treatment of intracranial aneurysms in pediatrics is dictated by their unusual pathology and liability to rehemorrhage. Although direct clipping has been the standard surgical technique, certain obsolete or innovative procedures should also be considered, such as entrapment, proximal occlusion, and endovascular embolisation, or even, in some cases, the non-invasive treatment of "watch and wait" for a spontaneous thrombosis. Six representative cases from King Faisal Specialist Hospital and Research Centre are reviewed. They reflect the diversity of the problem and the multi-disciplinary approach to the treatment. PMID:7627578

  15. A Histoenzymatic Study of Human Intracranial Atherosclerosis

    PubMed Central

    Hoff, Henry F.

    1972-01-01

    A light microscopy study on the localization of enzyme activity within atherosclerotic human intracranial arteries was performed on autopsy material obtained within 4 hours of death. The data suggests that the atherosclerotic process first goes through a proliferative phase and then a degenerative phase culminating in the formation of a plaque. In the proliferative phase, smooth muscle cell proliferation has formed a thickened intima. Tetrazolium reductase, adenosine triphosphatase (ATPase) and adenosine monophosphatase (AMPase) activities are present in these cells, while all dehydrogenases and acid phosphatase activities were weak or not present. As the degenerative phase commences, an area of necrosis, lipid and macrophage accumulation is formed on the lumen side of the elastica. This area increases in size until a plaque is formed. Unsaturated polar and nonpolar lipid, cholesterol, α-glycerophosphate dehydrogenase, acid phosphatase, and AMPase activities are associated with these areas and in foam cells, which are often found in the thickened intima of the proliferative phase. Tetrazolium reductase and ATPase activities decrease in the thickened intima as the area of necrosis increases in size, while dehydrogenase activity, except that for α-glycerophosphate, remains low or not present. Patterns of enzyme alterations for various stages of the disease process in intracranial arteries, the aorta and coronary arteries suggest a similar, if not identical, progression of the atherosclerotic process, irrespective of known differences in the prevalence of atherosclerosis. ImagesFig 2Fig 3Fig 5Fig 1Fig 4 PMID:4260721

  16. Molecular MRI of intracranial thrombus in a rat ischemic stroke model

    PubMed Central

    Uppal, Ritika; Ay, Ilknur; Dai, Guangping; Kim, Young Ro; Sorensen, A. Gregory; Caravan, Peter

    2010-01-01

    Background and Purpose Intracranial thrombus is a principal feature in most ischemic stroke, and thrombus location and size may correlate with outcome and response to thrombolytic therapy. EP-2104R, a fibrin-specific molecular MR agent, was previously shown to enhance extracranial thrombi in animal models and recently, in clinical trials. The purpose of this work was to determine if a fibrin-specific molecular MR probe could noninvasively characterize intracranial thrombi. Methods Embolic stroke was induced in adult rats by occlusion of the right internal carotid artery with an aged thrombus. Diffusion weighted imaging, time of flight angiography, and high resolution three dimensional T1-weighted MRI were performed at 4.7T prior to and following contrast agents EP-2104R (10 µmol/kg, n=6) or Gd-DTPA (200 µmol/kg, control, n=5). Gd levels in thrombus, brain, and blood were determined by ex vivo elemental analysis. Results In all animals, MR angiography revealed a flow deficit and diffusion-weighted imaging showed a hyperintensity consistent with ischemia. EP-2104R-enhanced MRI resulted in visualization of all occlusive thrombi (6/6) as well as vessel wall enhancement in all 6 animals with high contrast to noise relative to blood (10.7 post EP-2104R vs. 0.54 pre, p<0.0001). Gd-DTPA injected animals showed no occlusive thrombus or vessel wall enhancement (0/5). The concentration of Gd in the thrombus post-EP2104 was 18 times that in the blood pool. Conclusions EP-2104R enhanced MRI successfully identifies intracranial thrombus in a rat embolic stroke model. PMID:20395615

  17. Stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  18. Actin Rings of Power.

    PubMed

    Schwayer, Cornelia; Sikora, Mateusz; Slováková, Jana; Kardos, Roland; Heisenberg, Carl-Philipp

    2016-06-20

    Circular or ring-like actin structures play important roles in various developmental and physiological processes. Commonly, these rings are composed of actin filaments and myosin motors (actomyosin) that, upon activation, trigger ring constriction. Actomyosin ring constriction, in turn, has been implicated in key cellular processes ranging from cytokinesis to wound closure. Non-constricting actin ring-like structures also form at cell-cell contacts, where they exert a stabilizing function. Here, we review recent studies on the formation and function of actin ring-like structures in various morphogenetic processes, shedding light on how those different rings have been adapted to fulfill their specific roles. PMID:27326928

  19. New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring

    SciTech Connect

    de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R

    2006-02-02

    We compare near-infrared observations of the recently discovered outer rings of Uranus with HST results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G ring.

  20. A dimensionless parameter for classifying hemodynamics in intracranial

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the most important factors correlated to the IA rupture are hemodynamic factors such as wall shear stress (WSS) and oscillatory shear index (OSI) which are affected by the IA flows. Here, we carry out three-dimensional high resolution simulations on representative IA models with simple geometries to test a dimensionless number (first proposed by Le et al., ASME J Biomech Eng, 2010), denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports across the IA neck to the time required for vortex ring formation. Based on the definition, the flow mode is vortex if An>1 and it is cavity if An<1. We show that the specific definition of Le et al. works for sidewall but needs to be modified for bifurcation aneurysms. In addition, we show that this classification works on three-dimensional geometries reconstructed from three-dimensional rotational angiography of human subjects. Furthermore, we verify the correlation of IA flow mode and WSS/OSI on the human subject IA. This work was supported partly by the NIH grant R03EB014860, and the computational resources were partly provided by CCR at UB. We thank Prof. Hui Meng and Dr. Jianping Xiang for providing us the database of aneurysms and helpful discussions.

  1. The rice RING finger E3 ligase, OsHCI1, drives nuclear export of multiple substrate proteins and its heterogeneous overexpression enhances acquired thermotolerance

    PubMed Central

    Lim, Sung Don; Cho, Hyun Yong; Park, Yong Chan; Ham, Deok Jae; Lee, Ju Kyong; Jang, Cheol Seong

    2013-01-01

    Thermotolerance is very important for plant survival when plants are subjected to lethally high temperature. However, thus far little is known about the functions of RING E3 ligase in response to heat shock in plants. This study found that one rice gene encoding the RING finger protein was specifically induced by heat and cold stress treatments but not by salinity or dehydration and named it OsHCI1 (Oryza sativa heat and cold induced 1). Subcellular localization results showed that OsHCI1 was mainly associated with the Golgi apparatus and moved rapidly and extensively along the cytoskeleton. In contrast, OsHCI1 may have accumulated in the nucleus under high temperatures. OsHCI1 physically interacted with nuclear substrate proteins including a basic helix-loop-helix transcription factor. Transient co-overexpression of OsHCI1 and each of three nuclear proteins showed that their fluorescent signals moved into the cytoplasm as punctuate formations. Heterogeneous overexpression of OsHCI1 in Arabidopsis highly increased survival rate through acquired thermotolerance. It is proposed that OsHCI1 mediates nuclear–cytoplasmic trafficking of nuclear substrate proteins via monoubiquitination and drives an inactivation device for the nuclear proteins under heat shock. PMID:23698632

  2. Multiple hemorrhagic intraparenchymal tumors presenting with fatal intracranial hypertension: A rare manifestation of systemic epithelioid hemangioendothelioma

    PubMed Central

    Tsuchiya, Tsukasa; Oya, Soichi; Mori, Harushi; Matsui, Toru

    2015-01-01

    Background: Epithelioid hemangioendotheliomas (EHE) is an extremely rare tumor that can arise not only intracranially but also systemically. Its radiological characteristics and the mechanism underlying the multiple organ involvement in EHE are poorly understood. Case Description: A 24-year-old woman with a 7-month history of coughing and blood-stained sputum complained of visual disturbance in the right eye that had persisted for 1-month. Magnetic resonance (MR) imaging revealed multiple intraparenchymal masses with low-intensity on MR susceptibility-weighted images with minimal enhancement with gadolinium. Systemic computed tomography revealed multiple nodules in both lungs and the liver. Because her neurological status rapidly deteriorated, brain biopsy of the right frontal mass was performed. The pathological diagnosis was EHE. Over the following 3 months, the patient gradually developed disturbance of consciousness. She died at 4 months after admission because of significant intracranial hypertension. Conclusion: Although intracranial EHEs are extremely rare, they should be included in the differential diagnoses of multiple small-sized masses with low-intensity on MR susceptibility-weighted images. We also emphasize that the systemic involvement of this tumor was more compatible with multicentric development than metastasis. PMID:26539307

  3. High Agatston Calcium Score of Intracranial Carotid Artery

    PubMed Central

    Kao, Hung-Wen; Liou, Michelle; Chung, Hsiao-Wen; Liu, Hua-Shan; Tsai, Ping-Huei; Chiang, Shih-Wei; Chou, Ming-Chung; Peng, Giia-Sheun; Huang, Guo-Shu; Hsu, Hsian-He; Chen, Cheng-Yu

    2015-01-01

    Abstract The effect of intracranial internal carotid artery (ICA) calcification on cognitive impairment is uncertain. Our objective was to investigate whether intracranial ICA calcification is a significant cognitive predictor for cognitive impairment. Global cognition and degrees of intracranial ICA calcification of 579 subjects were assessed with Mini-Mental State Examination (MMSE) and Agatston calcium scoring method, respectively. Other risk factors for cognitive impairment, including age, education level, hypertension, diabetes mellitus, smoking, hyperlipidemia, and body mass index, were documented and analyzed for their associations with cognitive function. In univariate analyses, older age, lower education level, hypertension, diabetes mellitus, and higher intracranial ICA Agatston scores were significantly associated with cognitive impairment. In ordinal logistic regression, only age and total intracranial ICA Agatston score were significant risk factors for cognitive impairment. After adjustment for the other documented risk factors, subjects were 7% (95% CI: 5–10; P < 0.001) and 6% (95% CI: 0–13; P = 0.04) more likely to have lower cognitive category with every year increment of age and every 100-point increment of the total intracranial ICA Agatston score respectively. These results suggest an important role of the intracranial ICA calcification on cognitive impairment. PMID:26426620

  4. Postural Effects on Intracranial Pressure as Assessed Noninvasively

    NASA Technical Reports Server (NTRS)

    Ueno, Toshiaki; Hargens, Alan R.; Ballard, R. E.; Shuer, L. M.; Cantrell, J. H.; Yost, W. T.; Holton, Emily M. (Technical Monitor)

    1997-01-01

    This study was designed to investigate effects of whole body tilting on intracranial compliance and pressure in six healthy volunteers by using a noninvasive ultrasonic device. Subjects were randomly tilted up or down sequentially at 60 degree, 30 degree head-up, supine, and 15 degree head-down position for one minute at each angle. We measured arterial blood pressure with a finger pressure cuff and changes in intracranial distance with an ultrasonic device. The device measures skull movement on the order of micro-meter. Our ultrasound technique demonstrates that skull movement is highly correlated (r$(circumflex){2}$=0.77) with intracranial pressure variations due to cerebral arterial pulsation. The amplitudes of arterial pressure (r$(circumflex){2}$=0.99 and those of intracranial distance changes (r$(circumflex){2}$=0.87) associated with one cardiac cycle were inversely correlated with the angle of tilt. The ratio of pulsation amplitudes for intracranial distance over arterial pressure also showed a significant increase as the angle of tilt was lowered (p=0.003). Thus, postural changes alter intracranial compliance in healthy volunteers and intracranial volume-buffering capacity is reduced in head-down position.

  5. Molecular basis and genetic predisposition to intracranial aneurysm

    PubMed Central

    Weinsheimer, Shantel; Ronkainen, Antti; Kuivaniemi, Helena

    2014-01-01

    Intracranial aneurysms, also called cerebral aneurysms, are dilatations in the arteries that supply blood to the brain. Rupture of an intracranial aneurysm leads to a subarachnoid hemorrhage, which is fatal in about 50% of the cases. Intracranial aneurysms can be repaired surgically or endovascularly, or by combining these two treatment modalities. They are relatively common with an estimated prevalence of unruptured aneurysms of 2%–6% in the adult population, and are considered a complex disease with both genetic and environmental risk factors. Known risk factors include smoking, hypertension, increasing age, and positive family history for intracranial aneurysms. Identifying the molecular mechanisms underlying the pathogenesis of intracranial aneurysms is complex. Genome-wide approaches such as DNA linkage and genetic association studies, as well as microarray-based mRNA expression studies, provide unbiased approaches to identify genetic risk factors and dissecting the molecular pathobiology of intracranial aneurysms. The ultimate goal of these studies is to use the information in clinical practice to predict an individual's risk for developing an aneurysm or monitor its growth or rupture risk. Another important goal is to design new therapies based on the information on mechanisms of disease processes to prevent the development or halt the progression of intracranial aneurysms. PMID:25117779

  6. Seven patients diagnosed as intracranial hemorrhage combined with intracranial tumor: case description and literature review

    PubMed Central

    Zeng, Chun; Tang, Shuang; Jiang, Yongming; Xiong, Xuehua; Zhou, Shuai

    2015-01-01

    In the present study, 7 patients with brain hemorrhage combined with intracranial tumor were investigated for about 3 years. Furthermore, the previous reports related with such cases were also reviewed. In all of these patients, hemorrhage was a main characteristic of the diagnosed neoplasm. The clinical data were identified by computed tomography (CT) scanning in the present study. CT scanning results demonstrated that there was a neoplastic core with high or low density and multifocal clots generally at the borders of the tumors. Increase of tumor tissues with intravenous injection of approximate 70% hypaque was analyzed in all the 7 patients with brain hemorrhage. The parts that were increased showed peripheral distributions corresponding to the hemorrhage sites. In conclusion, the intracranial brain hemorrhage related with the several types of tumors, including hemangiopericytoma, metastatic carcinomas, oligodendroglioma, and glioblastoma multiforme, which may be helpful to these patients. PMID:26770623

  7. CT Perfusion Dynamics of Intracranial Tuberculomas

    PubMed Central

    N., Jayakumar Peruvumba; Shivashankar, Ravishankar

    2015-01-01

    Aims To study perfusion characteristics of intracranial tuberculomas and analyze changes with anti tubercular treatment. Materials and Methods Nineteen patients of histologically proven intracranial tuberculomas were included in the study of which 9 were not on antitubercular treatment and ten were on antitubercular treatment (6 patients on treatment for less than 2 months and 4 were more than 6 months). All patients underwent CT perfusion (CTP) and CTP parameters like rCBV and rCBF were obtained from entire lesion, center and capsule of lesions and compared. Results CTP parameters like rCBF and rCBV were significantly low in all the three ROIs in the group not on treatment compared to that of on treatment ; rCBF and rCBV of entire lesion (p=0.018 and p=0.005 respectively), capsule (p=0.045 and p=0.010 respectively) and center of the lesion (p=0.020 and p=0.009) respectively). Tuberculomas on antitubercular treatment of more than six months showed reduced rCBF and rCBV in entire lesion (p=0.01 & p=0.01 respectively), capsule (p=0.04 & p=0.03 respectively) and center (p=0.08 & p=0.05 respectively) compared to those on treatment for less than two months. Similarly tuberculomas on treatment for six months did not show significant difference in rCBF and rCBV compared to tuberculomas who were not on treatment. Tuberculomas on treatment for less than two months showed statistically increased rCBF and rCBV in entire lesion (p=0.01 & p=0.04 respectively), capsule (p=0.03 & p=0.01 respectively) and center (p= 0.03 &=0.01) compared to those not on treatment. Conclusion Intracranial tuberculomas not on treatment and those on treatment for around six months show low perfusion and tuberculomas on treatment for less than two months show high perfusion. These findings suggest that serial perfusion profiles of tuberculomas on treatment could possibly be seen as surrogate markers of response to treatment. PMID:26155528

  8. The Idiopathic Intracranial Hypertension Treatment Trial

    PubMed Central

    Wall, Michael; Kupersmith, Mark J.; Kieburtz, Karl D.; Corbett, James J.; Feldon, Steven E.; Friedman, Deborah I.; Katz, David M.; Keltner, John L.; Schron, Eleanor B.; McDermott, Michael P.

    2015-01-01

    IMPORTANCE To our knowledge, there are no large prospective cohorts of untreated patients with idiopathic intracranial hypertension (IIH) to characterize the disease. OBJECTIVE To report the baseline clinical and laboratory features of patients enrolled in the Idiopathic Intracranial Hypertension Treatment Trial. DESIGN, SETTING, AND PARTICIPANTS We collected data at baseline from questionnaires, examinations, automated perimetry, and fundus photography grading. Patients (n = 165) were enrolled from March 17, 2010, to November 27, 2012, at 38 academic and private practice sites in North America. All participants met the modified Dandy criteria for IIH and had a perimetric mean deviation between −2 dB and −7 dB. All but 4 participants were women. MAIN OUTCOMES AND MEASURES Baseline and laboratory characteristics. RESULTS The mean (SD) age of our patients was 29.0 (7.4) years and 4 (2.4%) were men. The average (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 39.9 (8.3). Headache was the most common symptom (84%). Transient visual obscurations occurred in 68% of patients, back pain in 53%, and pulse synchronous tinnitus in 52%. Only 32% reported visual loss. The average (SD) perimetric mean deviation in the worst eye was −3.5 (1.1) dB, (range, −2.0 to −6.4 dB) and in the best eye was −2.3 (1.1) dB (range, −5.2 to 0.8 dB). A partial arcuate visual field defect with an enlarged blind spot was the most common perimetric finding. Visual acuity was 85 letters or better (20/20) in 71% of the worst eyes and 77% of the best eyes. Quality of life measures, including the National Eye Institute Visual Function Questionnaire–25 and the Short Form–36 physical and mental health summary scales, were lower compared with population norms. CONCLUSIONS AND RELEVANCE The Idiopathic Intracranial Hypertension Treatment Trial represents the largest prospectively analyzed cohort of untreated patients with IIH. Our data show

  9. Capecitabine-related intracranial hypotension syndrome mimicking dural metastasis in a breast cancer patient: case report and review of the literature.

    PubMed

    Cosar-Alas, Rusen; Alas, Aykan; Ozen, Alaattin; Denizli, Bengu; Saynak, Mert; Uzunoglu, Sernaz; Aydogdu, Nurettin; Karagol, Hakan; Uzal, Cem; Kocak, Zafer

    2010-01-01

    Spontaneous intracranial hypotension (SICH) is an entity, which is secondary to iatrogenic manipulation and breaching of dura. Postural headache in patients should be suspected, cranial magnetic resonance imaging (MRI) is essential for precise diagnosis. Hallmark of MRI is regular shape of pachymeningeal gadolinium enhancement and subdural effusion. It may mimic central nervous system (CNS) metastasis. Prevention of such cases from receiving cranial radiotherapy by misinterpretation of the gadolinium enhancement as CNS metastasis is an important issue. Capecitabine is an antineoplastic agent, of which metabolites can cross blood-brain barrier in CNS via epithelial tissue. It may cause decrease in CSF production. SICH might be the clinical reflection of this decrease in CSF production. Review of the English literature revealed limited data because of the very little experience with oncologic patients suffering from intracranial hypotension. We report a case of spontaneous intracranial hypotension during capecitabine treatment. Patient was completely well following drug discontinuation and supportive treatment. PMID:21358101

  10. Intravenous digital subtraction angiography in the investigation of intracranial disease

    SciTech Connect

    DeFilipp, G.J.; Pinto, R.S.; Lin, J.P.; Kricheff, I.I.

    1983-07-01

    Eighty-six patients who presented with a variety of intracranial lesions were examined with intravenous digital subtraction angiogrphy (IV-DSA). A grading system was used to evaluate the ability IV-DSA to answer specific diagnostic questions regarding intracranial tumors, vasospasm following subarachnoid hemorrhage, lesions of the sella, dural sinus occlusion, and post-therapeutic embolization. Eighty-four percent of the examinations provided clinically useful information. In 15% of the cases limited but useful information was obtained; only 1% of the examinations provided no useful information. We conclude that IV-DSA can routinely provide useful information in the evaluation of the variety of intracranial lesions described above.