bluuebunny/crossref_metadata_2025_split huggingface dataset:
Placement of thoracolumbar pedicle screws using three-dimensional image guidance: experience in a large patient cohort
Authors: Nottmeier Eric W. , Seemer Will , Young Phillip M. 
Published: January 2009

Object
The goal of this study was to analyze the placement accuracy and complications of thoracolumbar pedicle screws (PSs) inserted using 3D image guidance in a large patient cohort.

Methods
The authors reviewed the charts of 220 consecutive patients undergoing posterior spinal fusion using 3D image guidance for instrumentation placement. A total of 1084 thoracolumbar PSs were placed using either the BrainLAB Vector Vision (BrainLAB, Inc.) or Medtronic StealthStation Treon (Medtronic, Inc.) image guidance systems. Postoperative CT scanning was performed in 184 patients, allowing for 951 screws to be graded by an independent radiologist for bone breach. All complications resulting from instrumentation placement were noted. Using the intraoperative planning function of the image-guided system, the largest diameter screw possible in each particular case was placed. The screw diameter of instrumentation placed into the L3–S1 levels was noted.

Results
No vascular or visceral complications occurred as a result of screw placement. Two nerve root injuries occurred in 1084 screws placed, resulting in a 0.2% per screw incidence and a 0.9% patient incidence of nerve root injury. Neither nerve root injury was associated with a motor deficit. The breach rate was 7.5%. Grade 1 and minor anterolateral “tip out” breaches accounted for 90% of the total breaches. Patients undergoing revision surgery accounted for 46% of the patients in this study. Accordingly, 154 screws placed through previous fusion mass could be evaluated using postoperative CT scanning. The breach rate in this specific cohort was 7.8%. A total of 765 PSs were placed into the L3–S1 levels in this study; 546 (71%) of these screws were ≥ 7.5 mm in diameter. No statistical difference in breach rate was noted in PSs placed through revision spinal levels versus nonrevision spinal levels (p = 0.499). Additionally, no increase in breach rate was noted with placement of 7.5-mm-diameter screws.

Conclusions
Three-dimensional image guidance is a useful adjunct to placement of spinal instrumentation. The complication rate in this study was low, and accurate placement of instrumentation was achieved despite the high percentage of revision surgery cases in our patient population. Additionally, because active fluoroscopy was not used for instrumentation placement, there was minimal to no radiation exposure to the surgeon or operating room staff.
Role of hyperbaric oxygen therapy in the treatment of bacterial spinal osteomyelitis
Authors: Ahmed Raheel , Severson Meryl A. , Traynelis Vincent C. 
Published: January 2009

Object
Hyperbaric oxygen therapy (HBO) is used as primary and/or adjunctive therapy in the treatment of various clinical conditions complicated by local hypoxia. It may have therapeutic potential in the treatment of neurosurgical infections such as spinal osteomyelitis that are associated with significant morbidity rates. The purpose of this study was to evaluate the efficacy of HBO therapy in the treatment of spinal osteomyelitis.

Methods
The clinical records of patients diagnosed with spinal osteomyelitis who received HBO therapy during their treatment at the authors' institution over the past 10 years were retrospectively reviewed. Six adult patients were identified. Four patients had recently undergone spinal surgery and secondary spinal osteomyelitis had developed. These patients received adjunctive HBO therapy due to significant comorbidities and risk factors for poor healing.

Results
All patients remained symptom and infection free over the subsequent follow-up period. Two patients had primary spinal osteomyelitis that had recurred despite a full course of appropriate antimicrobial therapy. Infection control was achieved after HBO therapy in 1 patient. The mean follow-up period for the study group was 2.9 years (range 5 months to 5 years).

Conclusions
Hyperbaric oxygen therapy enabled infection cure in 5 of 6 patients with spinal osteomyelitis complicated by medical comorbidities or the failure of primary therapy. These results show that HBO may be a useful adjunctive therapeutic modality in the treatment of spinal osteomyelitis, particularly when there are medical comorbidities that increase the risk of poor healing. Hyperbaric oxygen therapy may also be beneficial in patients with relapsing primary spinal osteomyelitis after standard therapy has failed.
Feasibility and potential value of flat-panel detector–based computed tomography in myelography after spinal surgery
Authors: Kau Thomas , Rabitsch Egon , Celedin Stefan , Jeschofnig Barbara , Illiasch Herbert , Eicher Wolfgang , Uhl Eberhard , Honl Matthias , Hausegger Klaus Armin 
Published: January 2009

Object
The purpose of this study was to assess the value of myelography using flat-panel detector–based computed tomography (fpCT) in 5 patients in whom the image quality of multislice CT (MSCT) or MR imaging was limited by metal artifacts.

Methods
The application of fpCT to myelographic imaging of the lumbar spine and cervicothoracic junction after surgery was feasible. Multiplanar, preferably sagittal, and 3D reconstructions adequately depicted disc space implants and provided high resolution images of osseous structures.

Results
The images obtained with fpCT allowed evaluation of anatomical details such as single nerve roots and proved especially valuable in a patient with impaired MR imaging results caused by metal artifacts from an intraoperative abrasion. In a case of recurrent disc herniation, imaging results of myelographic fpCT and MSCT scanning were in good agreement.

Conclusions
The novel imaging technique the authors describe yielded adequate results in patients with a history of spinal surgery, may be superior to MSCT scanning in depicting osseous structures and metallic implants, and has the potential to provide multilevel spinal images. Myelographic fpCT scanning may be the preferred modality in patients with expected or known metal artifacts on myelographic MSCT scans and/or MR images.
A novel strategy for repairing preganglionic cervical root avulsion in brachial plexus injury by sural nerve grafting
Authors: Wu Jau-Ching , Huang Wen-Cheng , Huang Ming-Chao , Tsai Yun-An , Chen Yu-Chun , Shih Yang-Hsin , Cheng Henrich 
Published: January 2009

Object
In this study, the authors evaluated the efficacy of a new surgical strategy for reconnecting the injured brachial plexus with the spinal cord using fibrin glue containing acidic fibroblast growth factor as an adhesive and neurotrophic agent.

Methods
Eighteen patients with preganglionic brachial plexus injuries, each with varying degrees of upper limb dysfunction, underwent cervical laminectomy with or without sural nerve grafting. The treatment of each avulsed root varied according to the severity of the injury. Some patients also underwent a second-stage operation involving supraclavicular brachial plexus exploration for reconnection with the corresponding segment of cervical spinal cord at the trunk level. Muscle strength was graded both pre- and postoperatively with the British Medical Research Council scale, and the results were analyzed with the Friedman and Wilcoxon signed-rank tests.

Results
Muscle strength improvements were observed in 16 of the 18 patients after 24 months of follow-up. Significant improvements in mean muscle strength were observed in patients from all repair method groups at 12 and 24 months postoperatively (p < 0.05). Statistical significance was not reached in the groups with insufficient numbers of cases.

Conclusions
The authors' new surgical strategy yielded clinical improvement in muscle strength after preganglionic brachial plexus injury, such that nerve regeneration may have taken place. Reconnection of the brachial plexus to the cervical spinal cord is possible. Functional motor recovery, observed through increases in Medical Research Council–rated muscle strength in the affected arm, is likewise possible.
Image-based drill templates for cervical pedicle screw placement
Authors: Ryken Timothy C. , Owen Brent D. , Christensen Gary E. , Reinhardt Joseph M. 
Published: January 2009

Object
Pedicle screws (PSs) in the cervical spine can provide fixation superior to current fixation methods; however, their implementation is challenging due to the small size of the cervical vertebrae. In this study, the authors explored and evaluated the use of patient-specific, rapid prototype drill templates for PS placement in the cervical spine. The goal of the study was to assess the accuracy of a drill template in the placement of cervical PSs at a single vertebral level.

Methods
Volumetric CT scanning was performed in 4 cadaveric cervical spines. Using computer software, the authors constructed drill templates with a predefined trajectory designed to match the posterior surface of vertebrae C3–7. Twenty physical templates were created from the computer models using a rapid prototyping machine. The drill templates were used to guide pilot-hole drilling, and CT scanning was performed to assess the accuracy of the pilot holes. Pedicle screws (3.5-mm diameter) were placed in the pilot holes. The spines were then dissected to separate the vertebrae, and the trajectory of the screws was visually inspected.

Results
The feasibility of this patient-specific, rapid prototyping technique was demonstrated. Imaging and visual inspection of pilot holes and cervical PSs revealed that the majority of trajectories did not violate the pedicle cortex (19 [95%] of 20). The single cortical violation was judged as noncritical and would probably not have resulted in injury to a patient.

Conclusions
The potential of drill templates to aid in the placement of cervical PSs is promising. The authors' methods appear to provide an accurate technique and trajectory for PS placement in the cervical spine.
Spinal cord vascular shunts: spinal cord vascular malformations and dural arteriovenous fistulas
Authors: da Costa Leodante , Dehdashti Amir R. , terBrugg E Karel G. 
Published: January 2009

Object
Spinal cord vascular malformations are rare, fascinating lesions. In this paper, the authors' goal was to demonstrate how these lesions, more specifically spinal cord arteriovenous malformations and dural arteriovenous fistulas, are assessed, classified, and managed at their institution. They also highlight some aspects of classification and management that may be different from the views of others.

Methods
The authors reviewed the 20-year experience at the senior author's institution regarding the management of spinal cord vascular malformations. They discuss the management, surgical and endovascular treatment results, and the classification that resulted from the combined experience of 3 major reference centers.

Results
The accumulated knowledge on embryological and pathophysiological aspects in such a rare disease resulted in a more global, patient-oriented (and not radiologically oriented) approach to spinal cord shunts.

Conclusions
The multiple classifications proposed for spinal cord vascular malformations reflect the continuous advancement of the authors' understanding. They adopt a classification based on new physiological and genetic data that treats these lesions as expressions of more complex disease processes and not simply a morphological target, with direct impact on therapeutic options.
Highly Efficient Organocatalyzed Direct Asymmetric Aldol Reactions of Hydroxyacetone and Aldehydes
Authors: Wu Xiaoyu , Ma Zhixiong , Ye Zhengqing , Qian Shan , Zhao Gang 
Published: January 2009

AbstractNovel organocatalysts derived from L‐threonine and L‐leucine have been synthesized for catalyzing direct aldol reactions of hydroxycetone and unactivated aliphatic aldehydes with as low as 2 mol% loading of the catalyst, good to excellent yields and excellent enantioselectivities have been achieved for aliphatic aldehydes, whereas aromatic aldehydes yield only moderate enantioselectivities.
The Ion Tag Strategy as a Route to Highly Efficient Organocatalysts for the Direct Asymmetric Aldol Reaction
Authors: Lombardo Marco , Easwar Srinivasan , Pasi Filippo , Trombini Claudio 
Published: January 2009

AbstractThe installation of an imidazolium tag via acetate connection to the C‐4 of cis‐4‐hydroxy‐L‐proline provides a highly efficient catalyst for the direct asymmetric aldol reaction, that works in a remarkably low catalyst loading (0.1 mol%) affording TONs up to 930 in the case of electron‐poor aromatic aldehydes with ee up to >99%.
Stereoselective Synthesis of Three Isomers of tert‐Butyl 5‐Hydroxy‐4‐methyl‐3‐oxohexanoate through Alcohol Dehydrogenase‐Catalyzed Dynamic Kinetic Resolution
Authors: Lüdeke Steffen , Richter Michael , Müller Michael 
Published: January 2009

AbstractRegioselective reduction of the 5‐keto group of tert‐butyl 4‐methyl‐3,5‐dioxohexanoate (1) leads to a stereodiad of tert‐butyl 5‐hydroxy‐4‐methyl‐3‐oxohexanoate (2). Alcohol dehydrogenases from Lactobacillus brevis (LBADH), Rhodococcus sp. (RS 1‐ADH) and Saccharomyces cerevisiae (YGL157w) reduce 1 under dynamic kinetic resolution conditions, thereby establishing two chiral carbons with a single reduction step. While it had been shown previously that LBADH reduction of 1 stereoselectively leads to syn‐(4S,5R)‐2, alcohol dehydrogenase‐mediated dynamic kinetic resolution now allows easy access to syn‐(4R,5S)‐2 (RS 1‐ADH; 97.6% ee, syn:anti=92:8, 66% conversion, 37% isolated yield) and anti‐(4S,5S)‐2 (YGL157w; 90% ee, anti:syn=93:7, 64% conversion, 42% isolated yield), as well. Thus three out of four possible stereoisomers were formed selectively upon reduction of 1.
Preferential crystallization: Multi‐objective optimization framework
Authors: Bhat Shrikant A. , Huang Biao 
Published: January 2009

AbstractA four objective optimization framework for preferential crystallization of D‐L threonine solution is presented. The objectives are maximization of average crystal size and productivity, and minimization of batch time and the coefficient of variation at the desired purity while respecting design and operating constraints. The cooling rate, enantiomeric excess of the preferred enantiomer, and the mass of seeds are used as the decision variables. The optimization problem is solved by using adaptation of the nondominated sorting genetic algorithm. The results obtained clearly distinguish different regimes of interest during preferential crystallization. The multi‐objective analysis presented in this study is generic and gives a simplified picture in terms of three zones of operations obtained because of relative importance of nucleation and growth. Such analysis is of great importance in providing better insight for design and decision making, and improving the performance of the preferential crystallization that is considered as a promising future alternative to chromatographic separation of enantiomers. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Asthma management: Reinventing the wheel in sickle cell disease
Authors: Morris Claudia R. 
Published: January 2009

AbstractAsthma is a common comorbidity in sickle cell disease (SCD) with a reported prevalence of 30–70%. The high frequency of asthma in this population cannot be attributed to genetic predisposition alone, and likely reflects in part, the contribution of overlapping mechanisms shared between these otherwise distinct disorders. There is accumulating evidence that dysregulated arginine metabolism and in particular, elevated arginase activity contributes to pulmonary complications in SCD. Derangements of arginine metabolism are also emerging as newly appreciated mechanism in both asthma and pulmonary hypertension independent of SCD. Patients with SCD may potentially be at risk for an asthma‐like condition triggered or worsened by hemolysis‐driven release of erythrocyte arginase and low nitric oxide bioavailability, in addition to classic familial asthma. Mechanisms that contributed to asthma are complex and multifactorial, influenced by genetic polymorphisms as well as environmental and infectious triggers. Given the association of asthma with inflammation, oxidative stress and hypoxemia, factors known to contribute to a vasculopathy in SCD, and the consequences of these factors on sickle erythrocytes, comorbid asthma would likely contribute to a vicious cycle of sickling and subsequent complications of SCD. Indeed a growing body of evidence documents what should come as no surprise: Asthma in SCD is associated with acute chest syndrome, stroke, pulmonary hypertension, and early mortality, and should therefore be aggressively managed based on established National Institutes of Health Guidelines for asthma management. Barriers to appropriate asthma management in SCD are discussed as well as strategies to overcome these obstacles in order to provide optimal care. Am. J. Hematol., 2009. © 2008 Wiley‐Liss, Inc.
Stabile Fünfring‐Allene mit ausschließlich Elementen der 2. Periode: keine Allene, sondern Zwitterionen
Authors: Christl Manfred , Engels Bernd 
Published: January 2009

AbstractEin Pyrazolderivat, das Dyker, Bertrand et al. für ein stabiles fünfgliedriges cyclisches Allen 1 a hielten, wird als Zwitterion 1 b reinterpretiert. Es wird dargelegt, dass die für Allene charakteristischen Bindungsverhältnisse für die Struktur 1 a nicht möglich sind. Ar = 2,6‐Dimethylphenyl.magnified image
Synthesis and characterization of poly(aryl ether ketone) oligomers terminated with metallophthalocyanine to be used for oxidative decomposition of TCP
Authors: Zhang Yunhe , Guo Meimei , Guan Shaowei , Zhang Ying , Jiang Zhenhua 
Published: January 2009

AbstractA series of metallophthalocyanine‐terminated poly(aryl ether ketone) oligomers were synthesized from dicyanobenzene‐terminated poly(aryl ether ketone) oligomers with different metal chloride and phthalonitrile. All polymers exhibited high glass transition temperature and good thermal stability. These polymers showed optical absorption in the visible region and had different colors in chloroform solution. Cobalt phthalocyanine‐terminated poly(aryl ether ketone) oligomers exhibited good catalytic activity in oxidative decomposition of 2,4,6‐trichlorophenol (TCP) under H2O2 and KHSO5. The catalytic activity of KHSO5 is much better than H2O2, and more than 70% of initial TCP was decomposed within 7 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Insights into prevention of human neural tube defects by folic acid arising from consideration of mouse mutants
Authors: Harris Muriel J. 
Published: January 2009

AbstractAlmost 30 years after the initial study by Richard W. Smithells and coworkers, it is still unknown how maternal periconceptional folic acid supplementation prevents human neural tube defects (NTDs). In this article, questions about human NTD prevention are considered in relation to three groups of mouse models: NTD mutants that respond to folate, NTD mutants and strains that do not respond to folate, and mutants involving folate‐pathway genes. Of the 200 mouse NTD mutants, only a few have been tested with folate; half respond and half do not. Among responsive mutants, folic acid supplementation reduces exencephaly and/or spina bifida aperta frequency in the Sp2H, Sp, Cd, Cited2, Cart1, and Gcn5 mutants. Prevention ranges from 35 to 85%. The responsive Sp2H (Pax3) mutant has abnormal folate metabolism, but the responsive Cited2 mutant does not. Neither folic nor folinic acid reduces NTD frequency in Axd, Grhl3, Fkbp8, Map3k4, or Nog mutants or in the curly tail or SELH/Bc strains. Spina bifida frequency is reduced in Axd by methionine and in curly tail by inositol. Exencephaly frequency is reduced in SELH/Bc by an alternative commercial ration. Mutations in folate‐pathway genes do not cause NTDs, except for 30% exencephaly in folate‐treated Folr1. Among folate‐pathway mutants, neural tube closure is normal in Cbs, Folr2, Mthfd1, Mthfd2, Mthfr, and Shmt1 mutants. Embryos die by midgestation in Folr1, Mtr, Mtrr, and RFC1 mutants. The mouse models point to genetic heterogeneity in the ability to respond to folic acid and also to heterogeneity in genetic cause of NTDs that can be prevented by folic acid. Birth Defects Research (Part A) 2009. © 2008 Wiley‐Liss, Inc.
Greening from the front to the back door? A typology of chemical and resource management services
Authors: Anttonen Markku 
Published: January 2009

AbstractThough services and product–service systems have been promoted as a promising way towards more eco‐efficient and sustainable societies, they have not turned into reality as expected. Chemical and resource management services are among the few operational examples. They aim to align the service provider's and customer's actions to reduce chemical usage and waste, improve supply chain management and increase resource efficiency. Arguably, they also create new business and higher profit margins compared with merely selling chemicals or handling industrial waste. Thus far they have been viewed as a single business model. In contrast, this study shows through the construction of five ideal types that the actual services and their focus vary. They range from the management of the chemical supply to operations, waste reduction, combined logistics services, process management, IT and other technologies. Consequently this affects the value creation, organization and environmental efficiencies of these services. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Assessing Carbohydrate–Carbohydrate Interactions by NMR Spectroscopy: The Trisaccharide Epitope from the Marine Sponge Microciona prolifera
Authors: Santos J. Ignacio , Carvalho de Souza Adriana , Cañada F. Javier , Martín‐Santamaría Sonsoles , Kamerling Johannis P. , Jiménez‐Barbero Jesús 
Published: January 2009

AbstractWeak recognition processes: Weak calcium‐mediated carbohydrate–carbohydrate interactions have been detected by DOSY and TRNOESY NMR methods by employing a gold glyconanoparticle as a multivalent system. In addition, 3D models of trisaccharide‐CaII‐trisaccharide complexes based on results from molecular dynamics simulations are proposed.magnified imageDiffusion‐ordered NMR spectroscopy (DOSY‐NMR) and TR‐NOESY‐NMR experiments are used to detect ligand binding to macromolecular receptors. These techniques have been applied to detect weak carbohydrate–carbohydrate self‐recognition in solution, making use of sugar‐decorated gold nanoparticles as the “macromolecule” and the same carbohydrate as the ligand. Changes in the diffusion coefficient of the free carbohydrate in the presence of the glyconanoparticle (only with CaII ions in the sample solution), as well as changes in the sign of the sugar NOE peaks—positive for the free sugar (in the presence or absence of CaII) and negative for the sugar only in the simultaneous presence of the glyconanoparticle and CaII ions—have been taken as proof of weak CaII‐mediated carbohydrate–carbohydrate interactions in solution. Although different methods such as SPR, TEM, and AFM have been used in the past to detect carbohydrate–carbohydrate interactions with the aid of gold nanoparticles and gold selfassembled monolayers, they are restricted to high‐affinity ranges. The methods used in this study allow expansion of the number of techniques to tackle this relevant biological problem, also for approaching ligand–receptor interactions below the high‐affinity range. Additionally, 3D models of trisaccharide‐CaII‐trisaccharide complexes based on results from molecular dynamics simulations are proposed.