bluuebunny/crossref_metadata_2025 huggingface dataset:
International Diversification and Forecast Optimism: The Effects of Reg FD
Authors: Herrmann Donald R. , Hope Ole-Kristian , Thomas Wayne B.
Published: June 2008

SYNOPSIS: Research shows that analysts following companies with a higher portion of foreign operations provide more optimistic forecasts, presumably to maintain favorable relations with management and thereby obtain improved access to information. We examine the effect of the introduction of Regulation Fair Disclosure (Reg FD) on analyst forecast bias for internationally diversified firms. We hypothesize that analysts’ incentives to issue optimistic forecasts for such firms should be reduced in the post-Reg FD era, because Reg FD prohibits firms from selectively disclosing management information to analysts. First, we demonstrate that average forecast bias decreases for our full sample of multinational firms. Second, we show that the positive relation between forecast optimism and international diversification significantly declines (and even disappears) in the post-Reg FD period. Reg FD appears to have been successful in reducing analysts’ optimistic bias and in reducing the effect of forecasting complexity on forecast bias for our sample of multinational firms. In a sensitivity test, we also find that the relation between international operations and forecast accuracy improves in the post-Reg FD period.
The Pricing of Realized Tax Benefits from NOL Carryforwards: Effect of Income Statement Presentation
Authors: Atwood T. J. , Reynolds J. Kenneth
Published: June 2008

ABSTRACT: We examine the pricing of realized tax benefits from net operating loss (NOL) carryforwards across income statement presentations. During the period 1987 through 1992, firms adopting SFAS No. 96 reported these tax benefits as part of income before extraordinary items (via a reduced provision for income tax expense), while non-adopting firms reported these benefits as extraordinary income items under APB No. 11. We provide evidence that NOL tax benefits were priced rationally when reported as extraordinary income items under APB No. 11; however, NOL tax benefits were overpriced, relative to their one-year-ahead persistence, when included in income before extraordinary items under SFAS No. 96. Our results suggest that the rational pricing of income tax information is affected by its presentation in the income statement, despite the clear reporting of sufficient additional details in the footnotes. Our findings provide support for the Financial Accounting Standards Board’s tentative decision to report income taxes in a separate section of the income statement.
Resisting Framing Effects: The Importance of Prior Attitude on Estate Tax Preferences
Authors: Fatemi Darius J. , Hasseldine D. John , Hite Peggy A.
Published: June 2008

ABSTRACT: Understanding tax preferences toward the estate tax could help resolve the continuing debate on whether the tax should be repealed. Gathering public opinion, however, is not a simple task as differing frames can alter the solicited preferences. For example, the framing literature has shown that equivalent but countervailing frames can produce dissimilar responses. That is, providing positive descriptors of an attribute tends to lead to a more favorable evaluative response than does using negative descriptors (Levin et al. 1998). In contrast, the resistance literature has found that when respondents possess a prior counter attitude that conflicts with the descriptors, exposure to the descriptors can strengthen the original counter attitude. The estate tax, a contentious issue that is typically viewed negatively by taxpayers, provides an issue in which predictions from framing and resistance literatures are in direct contrast. Our study demonstrates that prior counter attitude reverses the expected framing effects. In sum, when respondents do not initially approve of an estate tax, favorable frames lead to more negative responses than do unfavorable frames.
Assessing the Combined Impact of 18 Common Genetic Variants of Modest Effect Sizes on Type 2 Diabetes Risk
Authors: Lango Hana ,   the U.K. Type 2 Diabetes Genetics Consortium, Palmer Colin N.A. , Morris Andrew D. , Zeggini Eleftheria , Hattersley Andrew T. , McCarthy Mark I. , Frayling Timothy M. , Weedon Michael N.
Published: June 2008

OBJECTIVES—Genome-wide association studies have dramatically increased the number of common genetic variants that are robustly associated with type 2 diabetes. A possible clinical use of this information is to identify individuals at high risk of developing the disease, so that preventative measures may be more effectively targeted. Here, we assess the ability of 18 confirmed type 2 diabetes variants to differentiate between type 2 diabetic case and control subjects.

RESEARCH DESIGN AND METHODS—We assessed index single nucleotide polymorphisms (SNPs) for the 18 independent loci in 2,598 control subjects and 2,309 case subjects from the Genetics of Diabetes Audit and Research Tayside Study. The discriminatory ability of the combined SNP information was assessed by grouping individuals based on number of risk alleles carried and determining relative odds of type 2 diabetes and by calculating the area under the receiver-operator characteristic curve (AUC).

RESULTS—Individuals carrying more risk alleles had a higher risk of type 2 diabetes. For example, 1.2% of individuals with >24 risk alleles had an odds ratio of 4.2 (95% CI 2.11–8.56) against the 1.8% with 10–12 risk alleles. The AUC (a measure of discriminative accuracy) for these variants was 0.60. The AUC for age, BMI, and sex was 0.78, and adding the genetic risk variants only marginally increased this to 0.80.

CONCLUSIONS—Currently, common risk variants for type 2 diabetes do not provide strong predictive value at a population level. However, the joint effect of risk variants identified subgroups of the population at substantially different risk of disease. Further studies are needed to assess whether individuals with extreme numbers of risk alleles may benefit from genetic testing.
Structural and optical properties of layers of pentacene formed by PLD method
Authors: Potera Piotr , Sagan Piotr , Virt Ihor , Kuzma Marian , Wisz Grzegorz , Rudyj Ihor , Frugynski Marian
Published: June 2008

Organic films fabrication offers the possibility of producing electronic devices of low weight, mechanical flexibility and low cost. One suitable material for organic film fabrigation which is the subject of the great interest is pentacene, because it is characterized by the large carrier mobility (∼1 cm2/Vs).

In this work, the growth of pentacene layers using pulse laser deposition (PLD) on different substrates (glass/ITO, Si) is described and various processing parameters are investigated. Two pulsed YAG:Nd3+ laser wavelengths were used for the ablation of the PLD target: the first harmonic at 1064 nm aGn:dNdth3+e second at 532 nm. The structure of the layers formed was examined using SEM and RHEED methods. The results were compared with results of optical spectroscopy studies. It will be shown that layers deposed using second harmonics have a higher quality than those for first harmonic. The other PLD parametersalso have a strong influence on the structure quality of layers.
Comparison of different technologies for alginate beads production
Authors: Prüsse Ulf , Bilancetti Luca , Bučko Marek , Bugarski Branko , Bukowski Jozef , Gemeiner Peter , Lewińska Dorota , Manojlovic Verica , Massart Benjamin , Nastruzzi Claudio , Nedovic Viktor , Poncelet Denis , Siebenhaar Swen , Tobler Lucien , Tosi Azzurra , Vikartovská Alica , Vorlop Klaus-Dieter
Published: June 2008

This paper describes the results of the round robin experiment “Bead production technologies” carried out during the COST 840 action “Bioencapsulation Innovation and Technologies” within the 5th Framework Program of the European Community. In this round robin experiment, calcium alginate hydrogel beads with the diameter of (800 ± 100) μm were produced by the most common bead production technologies using 0.5–4 mass % sodium alginate solutions as starting material. Dynamic viscosity of the alginate solutions ranged from less than 50 mPa s up to more than 10000 mPa s. With the coaxial air-flow and electrostatic enhanced dropping technologies as well as with the JetCutter technology in the soft-landing mode, beads were produced from all alginate solutions, whereas the vibration technology was not capable to process the high-viscosity 3 % and 4 % alginate solutions. Spherical beads were generated by the electrostatic and the JetCutter technologies. Slightly deformed beads were obtained from high-viscosity alginate solutions using the coaxial airflow and from the 0.5 % and 2 % alginate solutions using the vibration technology. The rate of bead production using the JetCutter was about 10 times higher than with the vibration technology and more than 10000 times higher than with the coaxial air-flow and electrostatic technology.
Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation
Authors: Abdel-Razik Hamada
Published: June 2008

Synthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.
Alkalimetric determination of hydrophobic pharmaceuticals using stabilized o/w emulsions
Authors: Shevchenko Ganna , Kulichenko Sergey
Published: June 2008

Protolytic properties of (+)-(S)-2-(6-methoxynaphthalen-2-yl)propanoic acid (naproxen), 2-(3-benzoylphenyl)propionic acid (ketoprofen), 4-chloro-N-(2-furylmethyl)-5-sulfamoylanthranilic acid (furosemide), and N-(2,3-dimethylphenyl)anthranilic acid (mefenamic acid) in “oil-in-water” emulsions stabilized by surfactants were studied. The procedures for alkalimetric determination of naproxen, ketoprofen, furosemide, and mefenamic acid in emulsion media with indication of the equivalence point pH-metrically and with the use of indicators were proposed.
Preparation of nanocrystalline anatase TiO2 using basic sol-gel method
Authors: Bi-Tao Xiong , Bao-Xue Zhou , Long-Hai Li , Jun Cai , Yan-Biao Liu , Wei-Min Cai
Published: June 2008

Nanocrystalline titanium dioxide particles with anatase structure and high thermal stability have been synthesized using the basic sol-gel method. The particle size and morphology were refined under hydrothermal conditions in the presence of different concentrations of tetramethylammonium hydroxide (TMAH) at 210°C and 230°C. XRD and TEM analysis showed that the TiO2 particles obtained were homogeneous and monodispersive at low contents of TMAH. All intense peaks, clearly observed in the XRD patterns, were assigned to the anatase phase and no rutile phase was observed. At high contents of TMAH, nanoscale small (10–30 nm) and larger (>100 nm) TiO2 particles were one-pot synthesized. The nanocrystalline TiO2 particles synthesized by this method have good thermal stability. With the sintering temperature of up to 650°C, all the XRD peaks maintained good agreement with the anatase reference data.
Extraction and analysis of ellagic acid from novel complex sources
Authors: Aguilera-Carbo Antonio , Augur Christopher , Prado-Barragan Lilia , Aguilar Cristóbal , Favela-Torres Ernesto
Published: June 2008

Ellagic acid (EA) was quantified by reversed-phase high-performance liquid chromatography (RPHPLC) coupled with photodiode array detection (DAD) in five fine-powdered plants collected from the semiarid region of Mexico. Samples analysed included Jatropha dioica branches (Dragon’s blood), Euphorbia antisyphyllitica branches (Candelilla), Turnera diffusa Willd leaves (Damiana), Flourensia cernua leaves (hojasén) and Punica granatum husk (pomegranate) at two maturity stages (“turning” or intermediate and maturated fruit, considered as positive controls). The results demonstrated high EA concentrations in all tested samples which are novel sources of this natural antioxidant. The method developed for the EA analysis is fast and it showed an excellent linearity range, repeatability, intra-and inter-day precision and accuracy with respect to the methods reported for the EA analysis.
3,5-Bis(2-hydroxyphenyl)-1H-1,2,4-triazole based ligands — protonation and metal complex formation
Authors: Stucky Stefan , Koch Nadine , Heinz Uwe , Hegetschweiler Kaspar
Published: June 2008

3,5-Bis(2-hydroxyphenyl)-1H-1,2,4-triazole (H2La) and 4-[3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]benzoic acid (H3Lb) have been prepared, and crystal structure of the intermediate 2-(2-hydroxyphenyl)-4H-1,3-benzoxazin-4-one has been determined. Temperature dependent 1H NMR spectroscopic measurements of H2La indicated dynamic behavior with the equilibrium between the two asymmetric tautomers. For H3Lb, pD-dependent 1H NMR spectroscopic measurements showed small but characteristic shifts in the range of 0 ≤ pD ≤ 1, indicative of a triazole nitrogen atom protonation; the corresponding pK a of 0.98 ± 0.04 was determined by spectrophotometric titrations. (H2O, 26°C, 1 M KCl/HCl). Formation of [FeIII(La)]+ (pH 2.5) and [FeIII(La)2]− (pH > 6) was verified by UV-Vis spectroscopy. Complex formation of H3Lb with Al3+ and VO2+ was investigated by 1H NMR spectroscopic titration and cyclic voltammetry, respectively. Single crystals of the phenoxo bridged [VVO(HLb)(EtO)]2·2EtOH were characterized by X-ray structural analysis.
Synthesis, crystal structure, and magnetic properties of a cobalt(II) complex with (3,5-dichloropyridin-4-yl)(pyridin-4-yl)methanol
Authors: Zhu Zhicheng , Mikuriya Masahiro
Published: June 2008

A novel bridging ligand, (3,5-dichloropyridin-4-yl)(pyridin-4-yl)methanol (I), and its cobalt(II) complex, [Co(I)2(NCS)2]n (II), were prepared. The structures of ligand I and complex II were determined by single crystal X-ray analysis. Magnetic susceptibility measurements were performed for cobalt (II) complex II. Compound I crystallised in orthorhombic space group Pbca with a = 7.6585(14) Å, b = 12.209(2) Å, c = 23.207(4) Å, V= 2170.0(7) Å3 and Z=8. Complex II crystallised in monoclinic space group P21/n with a = 13.223(8) Å, b = 16.959(10) Å, c = 13.948(8) Å, β = 115.395(10)°, V= 2826(3) Å3 and Z = 4. Each cobalt(II) ion is surrounded by two NCS− anions and four pyridyl moieties from two bridging ligands. Each bridging ligand connects two neighbouring Co(II) ions to form a 2-dimensional structure. Temperature dependence of the molar magnetic susceptibilities in the temperature range of 2–300 K revealed that magnetic interactions between the cobalt ions are weak.
Preparation and modification of collagen-based porous scaffold for tissue engineering
Authors: Sloviková Alexandra , Vojtová Lucy , Jančař Josef
Published: June 2008

In the effort to generate cartilage tissues using mesenchymal stem cells, porous scaffolds with prescribed biomechanical properties were prepared. Scaffolds with interconnected pores were prepared via lyophilisation of frozen hydrogels made from collagen modified with chitosan nanofibres, hyaluronic acid, copolymers based on poly(ethylene glycol) (PEG), poly(lactic-co-glycolic acid) (PLGA), and itaconic acid (ITA), and hydroxyapatite nanoparticles. The modified collagen compositions were cross-linked using N-(3-dimethylamino propyl)-N′-ethylcarbodiimide hydrochloride (EDC) combined with N-hydroxysuccinimide (NHS) in water solution. Basic physicochemical and mechanical properties were measured and an attempt to relate these properties to the molecular and supermolecular structure of the modified collagen compositions was carried out. Scaffolds containing hydrophilic chitosan nanofibres showed the highest swelling ratio (SR = 20–25) of all the materials investigated, while collagen modified with an amphiphilic PLGA-PEG-PLGA copolymer or functionalised with ITA exhibited the lowest swelling ratio (SR = 5–8). The best resistance to hydrolytic degradation was obtained for hydroxyapatite containing scaffolds. On the other hand, the fastest degradation rate was observed for synthetic copolymer-containing scaffolds. The results showed that the addition of hydroxyapatite or hyaluronic acid to the collagen matrix increases the rigidity in comparison to the collagen-chitosan scaffold. Collagen scaffold modified with hyaluronic acid presented reduced deformation at break while the presence of hydroxypatatite enhanced the scaffold deformation under tensile loading. The tensile elastic modulus of chitosan nanofibre collagen scaffold was the lowest but closest to the articular cartilage; however, the strength and deformation to failure increased up to 200 %.
Synthesis, characterization, fluorescence and redox features of new vic-dioxime ligand bearing pyrene and its metal complexes
Authors: Yilmaz Ismail , Kilic Ahmet , Yalcinkaya Hacer
Published: June 2008

A new vic-dioxime ligand, N,N′-bis(aminopyreneglyoxime) (LH2), and its copper(II), nickel(II) and cobalt(II) metal complexes were synthesized and characterized by elemental analyses, IR, UVVIS and 1H and 13C NMR spectra (for the ligand). Mononuclear complexes were synthesized by a reaction of ligand (LH2) and salts of Co(II), Ni(II), and Cu(II) in ethanol. The complexes have the metal-ligand ratio of 1: 2 and metals are coordinated by N,N′ atoms of vicinal dioximes. The ligand acts in a polydentate fashion bending through nitrogen atoms in the presence of a base, as do most vic-dioximes. Detection of a H-bonding in the Co(II), Ni(II), and Cu(II) complexes by IR revealed the square-planar MN4 coordination of mononuclear complexes. Fluorescent properties of the ligand and its complexes arise from pyrene units conjugated with a vic-dioxime moiety. Fluorescence emission spectra of the ligand showed a drastic decrease in its fluorescence intensity upon metal binding. The electrochemical properties of the complexes were studied by the cyclic voltammetry technique. The nickel complex displayed an irreversible oxidation process while the copper complex exhibited a quasi-reversible oxidation and reduction processes based on the copper Cu(II)/Cu(III) and Cu(II)/Cu(I) couples, respectively.
Sensitive determination of nitrogenous hydrochloride drugs via their reaction with ammonium molybdate
Authors: Feng Suling , Guo Limin
Published: June 2008

In a hydrochloric acid medium, benzhexol hydrochloride, cyproheptadine hydrochloride, and maprotiline hydrochloride, can react with ammonium molybdate to form ion-association complexes by virtue of electrostatic attraction and hydrophobic interaction which result in a significant enhancement of the resonance light scattering intensity. The maximum scattering wavelengths were found at 364 nm, 364 nm, and 381 nm for benzhexol hydrochloride, cyproheptadine hydrochloride, and maprotiline hydrochloride systems, respectively. Spectral characteristics of the three systems, influencing factors, and optimum conditions were investigated. The reason of resonance light-scattering enhancement and the mechanism of interactions between the drugs and ammonium molybdate were also discussed. Based on the linear relationship between the enhanced intensity of resonance light scattering and the concentration of drugs, a highly sensitive method for the determination of the three drugs was developed, the detection limits being 0.0110 μmol L−1, 0.0038 μmol L−1, and 0.0155 μmol L−1 for benzhexol hydrochloride, cyproheptadine hydrochloride, and maprotiline hydrochloride, respectively. The method was successfully applied to the determination of the investigated drugs in pharmaceutical, serum, and urine samples.
Flow injection spectrophotometric determination of iron(III) using diphenylamine-4-sulfonic acid sodium salt
Authors: Asan Adem , Andac Muberra , Isildak Ibrahim , Tinkilic Nihat
Published: June 2008

A highly sensitive and very simple spectrophotometric flow-injection analysis (FIA) method for the determination of iron(III) at low concentration levels is presented. The method is based on the measurement of absorbance intensity of the red complex at 410 nm formed by iron(III) and diphenylamine-4-sulfonic acid sodium salt (DPA-4-SA). It is a simple, highly sensitive, fast, and low cost alternative method using the color developing reagent DPA-4-SA in acetate buffer at pH 5.50 and the flow-rate of 1 mL min−1 with the sample throughput of 60 h−1. The method provided a linear determination range between 5 μg L−1 and 200 μg L−1 with the detection limit (3S) of 1 μg L−1 of iron(III) using the injection volume of 20 μL. FIA variables influencing the system performance were optimized. The amount of iron(III) and total iron in river and seawater samples was successfully determined. Repeatability of the measurements was satisfactory at the relative standard deviation of 3.5 % for 5 determinations of 10 μg L−1 iron(III). The accuracy of the method was evaluated using the standard addition method and checked by the analysis of the certified material Std Zn/Al/Cu 43 XZ3F.
Synthesis and magnetic properties of polymeric complexes containing ruthenium(II)-ruthenium(III) tetracarboxylato units linked by cyanato, thiocyanato, and selenocyanato ligands
Authors: Handa Makoto , Ishida Hideaki , Ito Kayoko , Adachi Toshihiro , Ikeue Takahisa , Hiromitsu Ichiro , Mikuriya Masahiro , Kasuga Kuninobu
Published: June 2008

Polymeric complexes of ruthenium(II)-ruthenium(III) tetracarboxylato units linked by cyanato, thiocyanato, and selenocyanato ligands [Ru2{O2C(CH2)mCH3}4(L)]n (m = 0, 4–7; L = OCN−, SCN−, and SeCN−) were prepared and characterized based on the elemental analyses, IR, and diffuse reflectance spectra. Magnetic susceptibilities were measured at the temperature range of 4.5 K to 300 K, where the interdimer antiferromagnetic interactions were revealed. The strongest interaction was exhibited in case of m = 7 and L = OCN−. 1H-NMR spectra of [Ru{O2C(CH2)7CH3}4(SCN)]n in CD2Cl2 showed broad signals which can be ascribed to polymeric species, as the addition of tetrabutylammonium thiocyanate caused sharper signals due to the formation of [Ru2{O2C(CH2)7CH3}4(SCN)2]− adduct as the main species in the solution.
Student and Non-Student Perceptions and Awareness of Identity Theft
Authors: Winterdyk John , Thompson Nikki
Published: July 2008

Several recent reports have recognized identity theft as a major concern to law-enforcement agencies and the judicial system in Canada. While there is considerable descriptive information on identity theft and identity fraud in Canada, there is a dearth of information about peoples’ knowledge and awareness of identity theft and their potential risk to becoming a victim. This study measured the self-reported perception and awareness about the nature, extent, risk, and effects of identity theft and a variety of fraudulent behaviours among 360 college/university students and 106 non-students using a 5-point Likert scale survey. The findings indicate that students are perhaps slightly more at risk but are also somewhat better informed than adult non-students about identity theft. Based on the findings, some general policy implications and educational strategies are offered to better combat identity theft in Canada. A number of suggestions for future research are also proposed.
Physiological, Sensory, and Functional Measures in a Model of Wrist Muscle Injury and Recovery
Authors: Tiidus Peter M. , Brown Lindsay , Brant Aron , Enns Deborah , Bryden Pamela J.
Published: July 2008

Purpose: To evaluate the effectiveness of muscle rehabilitation modalities, it is first necessary to develop a model to test measures that would assess physiological, sensory, and functional muscle recovery. This study attempted to develop such a model for wrist injury.

Subjects: Healthy male and female adults (n = 25).

Methods: Subjects performed wrist muscle damage assessment, soreness, discomfort, difficulty, and functional motor task tests before and 1, 2, and 7 days after eccentric wrist muscle contractions. Wrist-related motor task tests, including the perception of discomfort and difficulty during performance, were also conducted.

Results: At 24 hours post–eccentric exercises, wrist extension and flexion force declined (p < 0.05) and soreness (p < 0.05) and circumference (p < 0.05) increased; all returned to normal by 7 days post-exercise. At 24 and 48 hours post-exercise, perception of discomfort and difficulty was elevated during performance of motor tasks (p < 0.05). The completion speed of motor tasks was unaffected at any time post–eccentric exercise (p > 0.05).

Conclusions: Loss of wrist muscle force, increased soreness, task discomfort, and difficulty were noted following eccentric exercise. However, subjects appeared able to compensate, such that the speed of completion of motor tasks was not slowed. Longer or more specific motor tasks may be necessary to mimic real work performance decrement and recovery.
From prefrontal leukotomy to deep brain stimulation: the historical transformation of psychosurgery and the emergence of neuroethics
Authors: Wind Joshua J. , Anderson Douglas E.
Published: June 2008

The history of psychosurgery is described and analyzed. This historical perspective largely begins with analysis of the work of Egas Moniz in the development of the leukotomy, and follows the rise and fall of its popularity in the 1900s. The reemergence of psychosurgical procedures and the development of new therapeutic technologies such as vagus nerve stimulation and deep brain stimulation are discussed. In addition, an introduction to the field of neuroethics is provided, given its importance in any discussion about surgical therapy for psychiatric patients.
Ablative neurosurgery for mental disorders: is there still a role in the 21st century? A personal perspective
Authors: Eljamel M. Sam
Published: June 2008

Object

The author presents his personal perspective on ablative neurosurgical techniques used to perform bilateral anterior cingulotomy (BACI) and bilateral anterior capsulotomy (BACA) for ameliorating the symptoms of refractory obsessive-compulsive disorder (OCD) and treatment refractory depression (TRD). With depression predicted to be the second most common cause of disability in the world by the year 2020 and the birth of electric neurostimulation representing an attractive alternative treatment option for TRD and OCD, it is desirable to revisit the pros and cons of these treatment options.

Methods

The author reviewed the surgical methods and outcome (including neuroimaging findings) in all cases in which ablative neurosurgery was performed at Ninewells Hospital and Medical School over the last 2 decades.

Results

The advantages of ablative procedures (BACI and BACA) from patients’ and psychiatrists’ perspectives are that the ablative procedures are one-off procedures that do not require lifelong commitment to program the stimulation devices, fix hardware failures, or change exhausted batteries. From the perspective of healthcare funding bodies, the relatively low cost of these treatments is an advantage. The main disadvantages of BACI and BACA are the perceived higher complication rates, the irreversibility of the surgical lesions, and the stigma associated with brain destruction in psychiatric patients that are still unpalatable in the community at large. However, some patients still choose a one-off procedure in preference to any other options presented to them.

Conclusions

There is still place for BACI and BACA in modern neurosurgery for mental disorders, at least in the short term for those who do not want to commit to lifelong device programming and maintenance.
The neurosurgical treatment of addiction
Authors: Stelten Bianca M. L. , Noblesse Lieke H. M. , Ackermans Linda , Temel Yasin , Visser-Vandewalle Veerle
Published: June 2008

Addiction or substance dependence is a psychiatric disorder that affects many individuals in the general population. Different theories concerning the neurobiological aspects of addiction have been proposed. Special attention has been paid to models concerning dysregulation of the reward circuit and the inhibitory control system within the cortico-basal ganglia-thalamocortical pathways. In the past, attempts have been made to treat patients suffering from addiction by performing psychosurgery. Lesions were created in specific brain regions that were believed to be dysfunctional in addiction. Procedures such as cingulotomy, hypothalamotomy, and resection of the substantia innominata and the nucleus accumbens have been described as a treatment for severe addictive disorders. Deep brain stimulation, a neurosurgical treatment that has been proven to be a safe alternative for lesions in the treatment of movement disorders, has more recently been proposed as treatments for severe psychiatric conditions such as treatment-refractory obsessive-compulsive disorder and depression. With the expanding knowledge of the neurobiology of addiction, deep brain stimulation could be a future option in the treatment arsenal of addiction.
Stereotactic amygdalotomy in the management of severe aggressive behavioral disorders
Authors: Mpakopoulou Maria , Gatos Haralambos , Brotis Alexandros , Paterakis Konstantinos N. , Fountas Kostas N.
Published: June 2008

Object

Stereotactic amygdalotomy has been utilized as a surgical treatment for severe aggressive behavioral disorders. Several clinical studies have been reported since the first description of the procedure. In the current study, the authors reviewed the literature and evaluated the surgical results, neuropsychological outcome, and complication rate in patients who had undergone stereotactic amygdalotomy for severe aggressive behavioral disorders.

Methods

The PubMed database was searched using the following terms: “amygdalotomy,” “amygdalectomy,” “amygdaloidectomy,” “psychosurgery,” “aggressive disorder,” and “behavioral disorder.” Clinical series with more than 5 patients undergoing stereotactic amygdalotomy for aggressive or other behavioral disorders were included in this review. The surgical technique, anatomical target, improvement in psychiatric symptomatology, postoperative employment and social rehabilitation, postoperative neurocognitive function, procedure-related complications, and long-term follow-up were evaluated.

Results

Thirteen clinical studies met our inclusion criteria. Reported postoperative improvement in aggressive behavior varied between 33 and 100%. Procedure-related complication rates ranged from 0 to 42%, whereas the mortality rate was as high as 3.8%. In the majority of the reviewed clinical series, the performance of stereotactic amygdalotomy did not compromise a patient’s learning, language, and intellectual capabilities. The long-term follow-up, although very limited, revealed that initially observed improvement was maintained in most cases.

Conclusions

Stereotactic amygdalotomy can be considered a valid surgical treatment option for carefully selected patients with medically refractory aggressive behavioral disorders. Recent advances in imaging and stereotactic navigation can further improve outcome and minimize the complication rate associated with this psychosurgical procedure.
Electrical stimulation in the lateral hypothalamus in rats in the activity-based anorexia model
Authors: Welkenhuysen Marleen , van Kuyck Kris , Das John , Sciot Raf , Nuttin Bart
Published: June 2008

Object

One quarter of patients with anorexia nervosa have a poor outcome and continue to suffer chronically or die. Electrical brain stimulation may be of therapeutic benefit in some of these patients; however, the brain target for inducing symptom relief is unknown. In this study, the authors evaluated the effects of acute and chronic electrical stimulation in the lateral hypothalamus on food intake, locomotor activity, and survival time in rats in an activity-based anorexia model.

Methods

In an acute experiment, the authors electrically stimulated at 100 Hz and 0, 25, 50 and 75% of the maximal stimulation amplitude (that is, the amplitude leading to severe side effects) in the lateral hypothalamus on consecutive days during 4 test sessions in 10 rats and evaluated food intake and locomotor activity. In a chronic experiment, they compared food intake, wheel revolutions, and survival time between 6 rats that underwent electrical stimulation in the lateral hypothalamus (50% of maximal stimulation amplitude) and 8 rats that did not undergo stimulation.

Results

In the acute experiment, overall electrical stimulation (25, 50, and 75% combined) and stimulation at 75% of the maximal stimulation amplitude significantly decreased the locomotor activity. However, if the authors omitted results of 1 rat, in which the electrode tip was not located in the lateral hypothalamus on one side but rather in the supraoptic chiasm, the remaining results did not yield significance. No other differences were observed.

Conclusions

When the findings of the current study are extrapolated to patients with anorexia nervosa, the authors do not expect major effects on symptoms with electrical stimulation at high frequency in the lateral hypothalamus.
Lennart Heimer: concepts of the ventral striatum and extended amygdala
Authors: Elias W. Jeff , Ray Dibyendu Kumar , Jane John A.
Published: June 2008

Dr. Lennart Heimer, the famous neuroanatomist of Swedish descent, died last year but left a legacy that will impact the neurosciences and potentially psychosurgery for years to come. He developed an anatomical technique for demonstrating the terminal boutons that helped to delineate basal forebrain anatomy. During these studies, he realized the relationship of basal forebrain structures to the limbic system, thus initiating the concept of the ventral striatum and parallel basal ganglia circuitry.

Heimer excelled as a teacher as well and honed his brain dissection technique to one of the most effective tools for understanding neuroanatomy. His legendary sessions with neurosurgical residents resulted in his recognition as one of the world’s leading fiber tract dissectors. His gentle, engaging manner has been documented in several media formats.
Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series
Authors: Gardner Paul A. , Kassam Amin B. , Snyderman Carl H. , Carrau Ricardo L. , Mintz Arlan H. , Grahovac Steven , Stefko Susan
Published: June 2008

Object

Craniopharyngiomas are challenging tumors that most frequently occur in the sellar or suprasellar regions. Microscopic transsphenoidal resections with various extensions and variations have been performed with good results. The addition of the endoscope as well as the further expansion of the standard and extended transsphenoidal approaches has not been well evaluated for the treatment of this pathological entity.

Methods

The authors performed a retrospective review of all patients who underwent a purely endoscopic, expanded endonasal approach (EEA) for the resection of craniopharyngiomas at their institution between June 1999 and February 2006. Endocrine and ophthalmological outcomes, extent of resection, and complications were evaluated.

Results

Sixteen patients underwent endoscopic EEA for the resection of craniopharyngiomas. Five patients (31%) presented with recurrent disease. Complete resection was planned in 11 of the 16 patients. Three elderly patients with vision loss underwent planned debulking, 1 patient with vision loss and a moderate-sized tumor had express wishes for debulking, and 1 patient had a separate, third ventricular nodule that was not resected. Of those in whom complete resection was planned, 91% underwent near-total (2/11) or gross-total (8/11) resection. No patient who underwent gross-total resection suffered a recurrence. The mean follow-up period was 34 months. Of the 14 patients who presented with vision loss, 93% had improvement or complete recovery and 1 patient's condition remained stable. No patient experienced visual worsening. Eighteen percent of patients (without preexisting hypopituitarism) developed panhypopituitarism and 8% developed permanent diabetes insipidus. There were no cases of new obesity. The postoperative cere-brospinal fluid leak rate was 58%. All leaks were resolved, and there were no cases of bacterial meningitis. There was 1 vascular injury (posterior cerebral artery perforator branch) resulting in the only new neurological deficit. No patient died.

Conclusions

Endoscopic EEA for the resection of craniopharyngiomas provides acceptable results and holds the potential to improve outcomes.
Thyroid-stimulating hormone pituitary adenomas
Authors: Clarke Michelle J. , Erickson Dana , Castro M. Regina , Atkinson John L. D.
Published: June 2008

Object

Thyroid-stimulating hormone (TSH)–secreting pituitary adenomas are rare, representing < 2% of all pituitary adenomas.

Methods

The authors conducted a retrospective analysis of patients with TSH-secreting or clinically silent TSH-immunostaining pituitary tumors among all pituitary adenomas followed at their institution between 1987 and 2003. Patient records, including clinical, imaging, and pathological and surgical characteristics were reviewed. Twenty-one patients (6 women and 15 men; mean age 46 years, range 26–73 years) were identified. Of these, 10 patients had a history of clinical hyperthyroidism, of whom 7 had undergone ablative thyroid procedures (thyroid surgery/131I ablation) prior to the diagnosis of pituitary adenoma. Ten patients had elevated TSH preoperatively. Seven patients presented with headache, and 8 presented with visual field defects. All patients underwent imaging, of which 19 were available for imaging review. Sixteen patients had macroadenomas.

Results

Of the 21 patients, 18 underwent transsphenoidal surgery at the authors' institution, 2 patients underwent transsphenoidal surgery at another facility, and 1 was treated medically. Patients with TSH-secreting tumors were defined as in remission after surgery if they had no residual adenoma on imaging and had biochemical evidence of hypo-or euthyroidism. Patients with TSH-immunostaining tumors were considered in remission if they had no residual tumor. Of these 18 patients, 9 (50%) were in remission following surgery. Seven patients had residual tumor; 2 of these patients underwent further transsphenoidal resection, 1 underwent a craniotomy, and 4 underwent postoperative radiation therapy (2 conventional radiation therapy, 1 Gamma Knife surgery, and 1 had both types of radiation treatment). Two patients had persistently elevated TSH levels despite the lack of evidence of residual tumor. On pathological analysis and immunostaining of the surgical specimen, 17 patients had samples that stained positively for TSH, 8 for α-subunit, 10 for growth hormone, 7 for prolactin, 2 for adrenocorticotrophic hormone, and 1 for follicle-stimulating hormone/luteinizing hormone. Eleven patients (61%) ultimately required thyroid hormone replacement therapy, and 5 (24%) required additional pituitary hormone replacement. Of these, 2 patients required treatment for new anterior pituitary dysfunction as a complication of surgery, and 2 patients with preoperative partial anterior pituitary dysfunction developed complete panhypopituitarism. One patient had transient diabetes insipidus. The remainder had no change in pituitary function from their preoperative state.

Conclusions

Thyroid-stimulating hormone–secreting pituitary lesions are often delayed in diagnosis, are frequently macroadenomas and plurihormonal in terms of their pathological characteristics, have a heterogeneous clinical picture, and are difficult to treat. An experienced team approach will optimize results in the management of these uncommon lesions.
Dissecting aneurysms of the posterior inferior cerebellar artery: retrospective evaluation of management and extended follow-up review in 6 patients
Authors: Nussbaum Eric S. , Madison Michael T. , Myers Mark E. , Goddard James , Janjua Tariq
Published: June 2008

Object

The authors report the management protocol and successful outcomes in 6 patients with dissecting aneurysms of the posterior inferior cerebellar artery (PICA).

Methods

Medical records and neuroimaging studies of 6 patients who underwent surgical treatment of dissecting PICA aneurysms were reviewed. The mean follow-up duration was 1.8 years. No patient was lost to follow-up review.

Results

Four patients presented with acute subarachnoid hemorrhage and 2 with PICA ischemia. All patients underwent surgery, which entailed proximal occlusion with distal revascularization in 3 cases and circumferential wrap/clip reconstruction in 3 cases. The revascularization techniques used were occipital artery–PICA bypass and PICA–PICA anastomosis. Delayed follow-up angiography was performed in all cases. In patients treated with proximal occlusion, delayed angiography showed minimal retrograde opacification of the dissected segments. The 3 patients treated with wrap/clip reconstruction showed unexpectedly significant normalization of their lesions on angiographic studies. Outcome was good in all cases.

Conclusions

Dissecting PICA aneurysms are rare lesions with an apparent propensity for bleeding. Individualized management including distal revascularization with PICA sacrifice or circumferential wrap/clip reconstruction to reinforce the dissected segment produced good outcomes. Patients treated with aneurysm wrapping may show dramatic angiographic improvement of the dissected segment.
Treatment of ruptured lenticulostriate artery aneurysms
Authors: Gandhi Chirag D. , Gilad Ronit , Patel Aman B. , Haridas Abilash , Bederson Joshua B.
Published: June 2008

Object

Lenticulostriate artery (LSA) aneurysms are rarely reported in the literature, making management decisions challenging. Conservative, endovascular, and surgical treatments have been described primarily through case reports and reports of individual authors' experiences. The purpose of this study is to report neurological outcomes in a single-institution experience of ruptured lenticulostriate aneurysms treated surgically.

Methods

The authors have conducted a retrospective review of all cases involving patients with ruptured LSA aneurysms who presented to the Mt. Sinai Hospital neurosurgical service between September 2001 and January 2007.

Results

Over 5.4 years, the authors treated 6 patients with 7 LSA aneurysms—6 ruptured and 1 unruptured. The Hunt and Hess grade on admission ranged from I to IV, with subarachnoid hemorrhage in 5 of the 6 patients. Catheter angiography confirmed the presence of the aneurysms, and all patients underwent a pterional craniotomy and clipping or resection of the aneurysm, performed by a single surgeon.

Associated risk factors in our series of patients included hypertension, cocaine abuse, and intracranial occlusive disease suggestive of moyamoya disease. Two types of LSA aneurysms were identified. The mean size of the 6 ruptured aneurysms was 3.2 mm. The LSA was preserved in 3 of 6 patients, but LSA preservation did not correlate with development of a postoperative infarct, clinically or radiologically. In patients with ruptured aneurysms, the mean modified Rankin Scale score at discharge was 1.7. The 3 patients in whom the LSA was sacrificed had good outcomes, suggesting that loss of the artery is clinically well tolerated.

Conclusions

This case series demonstrates that surgical treatment of ruptured LSA aneurysms can be an appropriate, effective, and safe therapy.
Effect of ropivacaine skull block on perioperative outcomes in patients with supratentorial brain tumors and comparison with remifentanil: a pilot study
Authors: Gazoni Farnaz M. , Pouratian Nader , Nemergut Edward C.
Published: June 2008

Object

Skull blockade for craniotomy may result in the reduction of sympathetic stimulation associated with the application of head pins (“pinning”), improvement in intraoperative hemodynamic stability, and a decrease in intraoperative anesthetic requirements. Postoperative benefits may include a decrease in pain, in analgesic requirements, and in the incidence of nausea and vomiting. The authors examined the potential benefits of a skull block in patients in whom a maintenance anesthetic consisting of sevoflurane and a titratable remifentanil infusion was used. In other studies examining the ability of a skull block to improve perioperative outcomes, investigators have not used remifentanil.

Methods

Thirty patients presenting for resection of a supratentorial tumor were prospectively enrolled. Patients were randomized into 2 groups as follows: 14 patients (skull block group) received a skull block with 0.5% ropivacaine at least 15 minutes prior to pinning, whereas the remaining 16 patients (control group) did not.

Results

Patients in the skull block group did not have a significant increase in blood pressure or heart rate with placement of head pins, whereas patients in the control group did. Nevertheless, there was no difference in blood pressure variability between the groups. The mean intraoperative concentration of sevoflurane (1.0% in both groups, p = 0.703) and remifentanil (0.163 μg/kg/min compared with 0.205 μg/kg/min, p = 0.186) used was similar in both groups. During the postoperative period, there was no difference in the 1-, 2-, or 4-hour visual analog scale scores; in the need for postoperative narcotic analgesia (0.274 morphine equivalent mg/kg compared with 0.517 morphine equivalent mg/kg, p = 0.162); or in the incidence of nausea or vomiting.

Conclusions

Prospective analysis of perioperative skull blockade failed to demonstrate significant benefit in patients treated with a remifentanil infusion.
Effect of early nutrition on deaths due to severe traumatic brain injury
Authors: Härtl Roger , Gerber Linda M. , Ni Quanhong , Ghajar Jamshid
Published: June 2008

Object

Traumatic brain injury (TBI) remains a serious public health crisis requiring continuous improvement in pre-hospital and inhospital care. This condition results in a hypermetabolic state that increases systemic and cerebral energy requirements, but achieving adequate nutrition to meet this demand has not been a priority in reducing death due to TBI. The effect of timing and quantity of nutrition on death within the first 2 weeks of injury was analyzed in a large prospective database of adult patients with severe TBI in New York State.

Methods

The study is based on 797 patients with severe TBI (Glasgow Coma Scale [GCS] score < 9) treated at 22 trauma centers enrolled in a New York State quality improvement program between 2000 and 2006. The inhospital section of the prospectively collected database includes information on age, initial GCS score, weight and height, results of CT scanning, and daily parameters such as pupillary status, arterial hypotension, GCS score, and number of calories fed per day.

Results

Patients who were not fed within 5 and 7 days after TBI had a 2- and 4-fold increased likelihood of death, respectively. The amount of nutrition in the first 5 days was related to death; every 10-kcal/kg decrease in caloric intake was associated with a 30–40% increase in mortality rates. This held up even after controlling for factors known to affect mortality, including arterial hypotension, age, pupillary status, initial GCS score, and CT scan findings.

Conclusions

Nutrition is a significant predictor of death due to TBI. Together with prevention of arterial hypotension, hypoxia, and intracranial hypertension it is one of the few therapeutic interventions that can directly affect TBI outcome.