Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

BACKGROUND: Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria. OBJECTIVES: To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence. METHODS: A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review. RESULTS: A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue. CONCLUSIONS: Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients

Implementation of Quantum Gates via Optimal Control

Starting with the basic control system model often employed in NMR pulse design, we derive more realistic control system models taking into account effects such as off-resonant excitation for systems with fixed inter-qubit coupling controlled by globally applied electromagnetic fields, as well as for systems controlled by a combination of a global fields and local control electrodes. For both models optimal control is used to find controls that implement a set of two- and three-qubit gates with fidelity greater than 99.99%. While in some cases the optimal pulses obtained appear to be surprisingly simple and experimentally realistic, the results also show that the "optimal" pulses obtained in other cases are experimentally infeasible, and more sophisticated parametrization of the control fields and numerical algorithms are needed.Comment: 10 pages, 4 figure

Initial Experience with Awake Craniotomy In Sudan

Resection of brain tumours carries a great risk of functional impairment, especially if the tumour is located in the anterior temporal or frontal lobes, near motor, language, or memory areas of the brain. Awake craniotomy has been proposed aiming for maximum resection with minimum impairment of neurological function. The technique should provide adequate sedation, analgesia, respiratory and haemodynamic stability with an awake and cooperative patient for neurological testing. Airway management during a wake craniotomy is a crucial part of the anaesthetic technique, but it remains the subject of debate. In this case, who was the first patient operated upon as awake craniotomy in Sudan; awake craniotomy has been adopted as his cardiac function made surgery under general anaethesia a potential risk. The patient\'s tolerance to the procedure, haemodynamic stability, the incidence of airway obstruction and intraoperative and postoperative neurological status were assessed. The candidate well tolerated the procedure, with haemodynamic stability and a patent airway throughout the procedure. Convenient resection of the tumor was achieved and uneventful post-operative recovery with no neurological deficits was reported. Keywords: awake craniotomy, propofol, fentanyl.Sudan Journal of Medical Sciences Vol. 3 (2) 2008: pp. 171-17

Cholesterol promotes interaction of the protein CLIC1 with phospholipid monolayers at the air–water interface

© 2016 by the authors; licensee MDPI, Basel, Switzerland. CLIC1 is a Chloride Intracellular Ion Channel protein that exists either in a soluble state in the cytoplasm or as a membrane bound protein. Members of the CLIC family are largely soluble proteins that possess the intriguing property of spontaneous insertion into phospholipid bilayers to form integral membrane ion channels. The regulatory role of cholesterol in the ion‐channel activity of CLIC1 in tethered lipid bilayers was previously assessed using impedance spectroscopy. Here we extend this investigation by evaluating the influence of cholesterol on the spontaneous membrane insertion of CLIC1 into Langmuir film monolayers prepared using 1‐palmitoyl‐2‐oleoylphosphatidylcholine, 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phospho‐ethanolamine and 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phospho‐L‐serine alone or in combination with cholesterol. The spontaneous membrane insertion of CLIC1 was shown to be dependent on the presence of cholesterol in the membrane. Furthermore, pre‐incubation of CLIC1 with cholesterol prior to its addition to the Langmuir film, showed no membrane insertion even in monolayers containing cholesterol, suggesting the formation of a CLIC1‐cholesterol pre‐complex. Our results therefore suggest that CLIC1 membrane interaction involves CLIC1 binding to cholesterol located in the membrane for its initial docking followed by insertion. Subsequent structural rearrangements of the protein would likely also be required along with oligomerisation to form functional ion channels

Studies on the chemical composition and physicochemical properties of the seeds of baobab ( Adasonia digitata)

The seeds of baobab used in preparation of local condiments was analysed to establish the proximate composition and the physico-chemical characteristics of the oil and effect of storage on the oil. Results obtained showed that the saponification value (SV), iodine value (IV), peroxide value (PV), acid value (AV), percentage free fatty acid (%FFA) and refractive index of the oil are 196 ± 0.05 mg/KOH, 87 ± 0.02 g/100 g, 4.5 ± 0.06 mEq/kg, 0.33 ± 0.03 mgKOH/g, 0.45 ± 0.08 and 1.459 ± 0.13, respectively. Proximate analysis showed that protein (21.75 ± 0.12 g/100 g), ash (5.01 ± 0.07 g/100 g) and fiber (6.71 ± 0.003 g/100 g) were comparable to Prosopsis africana seeds (20.54 ± 0.18, 6.67 ± 0.08 and 5.51 g/100g), which is used for the same purpose. The crude lipid content (12.72 ± 0.01 g/100 g) was almost equal to that of P. africana seeds (12.74 g/100 g). The major mineral elements present in the seeds included phosphorus,calcium and potassium (6.00 ± 0.02, 58.90 ± 2.34 and 280.00 ± 1.34 mg/100 g, respectively), thereby suggesting that the baobab seeds could contribute partially to the overall daily intake of theseelements. The vitamins (A and C) found present in baobab seeds are higher than that of P. africana seeds. The antinutritional factors including oxalate, phytate, saponin and tannin (10.31 ± 1.00, 2.00 ±0.31, 7.16 ± 0.01, 2.84 ± 0.30%, respectively) are also comparable to that of P. Africana. The storage property of the oil from baobab seeds studied over a period of four weeks under conditions of light(ambient), darkness (ambient), and refrigeration showed that the iodine value of the oil decreased in all cases but much more so on exposure to light. In contrast, the peroxide value of the oil showed verylittle change under conditions of darkness and refrigeration over the same period, thus indicating that the oil can withstand storage

Paraoxonase 1 activity and genotyping in systemic lupus erythematosus and their relationships with cardiovascular complications

Introduction: Systemic lupus erythematosus (SLE) is characterized by an enhanced risk of atherosclerosis and cardiovascular diseases (CVD). Human serum paraoxonase 1 (PON1), an antioxidant enzyme closely associated with high density lipoprotein (HDL), has been implicated in the prevention of low density lipoprotein (LDL) oxidation, and these may provide HDL-associated protection against atherosclerosis. The Aim: Our objective was to evaluate PON1 activity and genotypes in SLE patients and their relationships to cardiovascular complications and some other risk factors of cardiovascular diseases in those patients. Patient and Methods: Thirty SLE patients, subdivided into patients with CVD and without CVD, and fifteen matched healthy control subjects were studied. Laboratory investigations included lipid profile, lupus anticoagulants (LA), anticardiolipin antibodies (aCL). PON1 activity was determined by paraoxon substrate. PON1 genotyping was conducted by PCR amplification, followed by polymorphism-specific restriction enzyme digestion and gel electrophoresis. Results: Our study revealed that PON1 activity was significantly decreased in SLE patients groups compared to controls and in SLE patients with CVD compared to those without CVD (

Trisomy 9 syndrome in a neonate with unusual features

Aim of the Work: To report a newborn infant with multiple congenital anomalies and apparent complete trisomy 9 in the blood. Review will be included.Methods: Clinical examination, TORCH screening, echocardiography, skeletal survey, ultrasound head and abdomen were done. In addition chromosomal analysis of a peripheral blood sample using GTG, CBG banding and FISH techniques were employed.Results: Multiple congenital anomalies including craniofacial features, centralnervous, cardiovascular, skeletal, gastric and urogenital systems becauseof chromosomal abnormality which indicated: 47, XY, inv (9) (p12;q13) + inv(9) (p12;q13) mat. Conclusion: Our case could be a new case of apparently complete trisomy 9syndrome with unusual findings.Key Words: Trisomy 9, congenital anomalies, karyotype, FIS

The Spin of Holographic Electrons at Nonzero Density and Temperature

We study the Green's function of a gauge invariant fermionic operator in a strongly coupled field theory at nonzero temperature and density using a dual gravity description. The gravity model contains a charged black hole in four dimensional anti-de Sitter space and probe charged fermions. In particular, we consider the effects of the spin of these probe fermions on the properties of the Green's function. There exists a spin-orbit coupling between the spin of an electron and the electric field of a Reissner-Nordstrom black hole. On the field theory side, this coupling leads to a Rashba like dispersion relation. We also study the effects of spin on the damping term in the dispersion relation by considering how the spin affects the placement of the fermionic quasinormal modes in the complex frequency plane in a WKB limit. An appendix contains some exact solutions of the Dirac equation in terms of Heun polynomials.Comment: 27 pages, 11 figures; v2: minor changes, published versio

Accretion disc winds in tidal disruption events: Ultraviolet spectral lines as orientation indicators

ABSTRACT Some tidal disruption events (TDEs) exhibit blueshifted broad absorption lines (BALs) in their rest-frame ultraviolet (UV) spectra, while others display broad emission lines (BELs). Similar phenomenology is observed in quasars and accreting white dwarfs, where it can be interpreted as an orientation effect associated with line formation in an accretion disc wind. We propose and explore a similar unification scheme for TDEs. We present synthetic UV spectra for disc and wind-hosting TDEs, produced by a state-of-the-art Monte Carlo ionization and radiative transfer code. Our models cover a wide range of disc wind geometries and kinematics. Such winds naturally reproduce both BALs and BELs. In general, sightlines looking into the wind cone preferentially produce BALs, while other orientations preferentially produce BELs. We also study the effect of wind clumping and CNO-processed abundances on the observed spectra. Clumpy winds tend to produce stronger UV emission and absorption lines, because clumping increases both the emission measure and the abundances of the relevant ionic species, the latter by reducing the ionization state of the outflow. The main effect of adopting CNO-processed abundances is a weakening of C iv 1550 Å  and an enhancement of N v 1240 Å  in the spectra. We conclude that line formation in an accretion disc wind is a promising mechanism for explaining the diverse UV spectra of TDEs. If this is correct, the relative number of BAL and BEL TDEs can be used to estimate the covering factor of the outflow. The models in this work are publicly available online and upon request.</jats:p